Entries |
Document | Title | Date |
20080223030 | Hydraulic Driving Device for Operating Machine - In a hydraulic driving device for an operating machine, when an output value of an operating device is in a first predetermined range, a pump is stopped and each of an open and closed valve and a hydraulic control valve is closed. When the output value goes beyond the first predetermined range, the pump is started and the open and closed valve is opened. When the output value goes beyond a second range greater than the first predetermined range, the hydraulic control valve is opened to supply a hydraulic fluid to an actuator. | 09-18-2008 |
20080256943 | Hydraulic control device - A hydraulic control device includes an oil pan; an oil pump; a strainer; a pressure regulating valve; an oil cooler; a cooler bypass valve with an input port that is connected with a cooler supply oil passage through which the hydraulic oil to be supplied to the oil cooler flows, wherein the input port is communicatively connected with an output port when the hydraulic pressure of the hydraulic oil within the cooler supply oil passage is equal to or greater than a predetermined valve opening pressure; and a cooler bypass oil passage that connects the output port of the cooler bypass valve with an intake oil passage between the strainer and the intake port of the oil pump. | 10-23-2008 |
20080295508 | Force feedback poppet valve having an integrated pressure compensator - The force feedback poppet valve includes a valve body having a main chamber, a first port, and a second port. The force feedback poppet valve further includes a main poppet disposed within the main chamber and movable between an open position and a closed position to control fluid flow between the first port and the second port. The main poppet forms a control chamber within the main chamber. The force feedback poppet valve further includes a first passage communicating the control chamber with the second port, a second passage communicating the control chamber with the first port, and a pilot valve having a pilot poppet for controlling fluid flow between the control chamber and the first port through the second passage. The force feedback poppet valve further includes a pressure compensator disposed within the main poppet, and fluidly connected to the second port via the first passage. The force feedback poppet valve further includes a first spring coupled between the main poppet and the pilot poppet to provide a force proportional to a distance between the main poppet and the pilot poppet, and a second spring coupled between the pressure compensator and the pilot poppet to provide a force proportional to a distance between the pressure compensator and the pilot poppet. | 12-04-2008 |
20080302099 | Method for Controlling a Hydraulic Cylinder and Control System for a Work Machine - A method is provided for controlling a hydraulic cylinder, including detecting at least one operating parameter, and variably controlling a communication path between the piston-rod side and piston side of the hydraulic cylinder on the basis of the detected operating parameter. | 12-11-2008 |
20090071145 | FLOW CONTROL APPARATUS FOR HEAVY CONSTRUCTION EQUIPMENT - A flow control apparatus for heavy construction equipment is provided, which can prevent overspeed and abrupt operations of an actuator due to an excessive flow rate during an initial operation of the actuator when a composite work is performed by simultaneously operating an option device and another actuator, and can prevent the cut-off of hydraulic fluid supply to the option device due to an operation inability of a flow control valve when leakage of the hydraulic fluid occurs due to the increase of the temperature of the hydraulic fluid. The flow control apparatus includes a hydraulic pump, an actuator for option devices, a variable control spool installed to be shifted by pilot signal pressure, a switching valve installed to be shifted by a difference between pressure in an inlet-side path and pressure in an outlet-side path of the variable control spool, a logic poppet installed to open/close a high-pressure path of the hydraulic pump, a groove formed on a sliding surface of the logic poppet, and a flow path for connecting the groove to an outlet-side path of the logic poppet. If leakage of hydraulic fluid through a gap formed on the sliding surface of the logic poppet occurs, mutual connection between the outlet-side path and a back chamber of the logic poppet is intercepted by the groove and the flow path. | 03-19-2009 |
20090107136 | ELECTROHYDRAULIC TRANSMISSION CONTROLLER, TRANSMISSION DEVICE, AND A MOTOR VEHICLE DRIVE TRAIN - An electrohydraulic transmission controller ( | 04-30-2009 |
20090151347 | Operation Control Circuit for Construction Machine - The operation control circuit of the present invention reduces the speed of an actuator, such as a rotation motor, according to reduction in the rotational speed of an engine. When the engine rotational speed is at its maximum, a pilot pressure in a pilot conduit is set to a relief pressure of a relief valve. When the engine rotational speed is reduced, the flow rate of pilot pressure hydraulic fluid decreases, and the pressure difference over a throttle section becomes smaller than the relief pressure, so that the pilot pressure is set to the pressure difference. Even if the operator operates an operation lever to a full stroke position the spool valve does not go to the fully opened state, since the pressure is low. As a result, the flow rate of hydraulic fluid supplied to the rotation motor is reduced, so that the speed of rotation is reduced. | 06-18-2009 |
20090188250 | Motor Vehicle Control Device for Regulating the Pressure of the Volumetric Flow of a Motor Vehicle Hydraulic Apparatus and Associated Pressure Regulation Method - A motor vehicle control device with a digital control loop has an actuator of an electrical actuator device in order to regulate the pressure of the volumetric flow of a motor vehicle hydraulic apparatus. A current limiting unit is provided in the forward path of the digital control loop between the digital controller of the latter and the actuator of the electrical actuator device. The current limiting unit, in order to protect the components of the electrical actuator device, limits the manipulated variable signal from the digital control loop if a predefined permissible current threshold value is exceeded in the electrical actuator device. The digital controller has an additional limiting unit which essentially limits the I component of its manipulated variable signal from the time at which the current limiting unit is activated. | 07-30-2009 |
20090235658 | INERTIAL BODY DRIVE SYSTEM - A pressure selector valve ( | 09-24-2009 |
20090249776 | LOCK VALVE WITH GROOVED PORTING IN BORE - A lock valve includes a lock valve body having a bore with a valve spool reciprocatingly received therein. There is a check valve adjacent each end of the bore. Each of the check valves has a check valve member facing the bore and resiliently biased towards a valve seat at each end of the bore. A pressure relief port communicates with the bore near the center thereof and between lands of the valve spool. A pair of spaced-apart grooves are disposed within the spool valve bore. Each groove permits fluid communication past a land of the valve spool when the valve spool is displaced towards one end of the bore by fluid pressure applied to other end of the bore so as to unseat the check valve member adjacent to the one end to the bore and allow pressurized fluid to pass from the one end of the bore, through the groove, and into the relief port. | 10-08-2009 |
20090282825 | Actuator Control Device - In an actuator control device that controls an expansion/contraction operation of a hydraulic cylinder, when a main spool | 11-19-2009 |
20090293470 | Over-Loading Prevention Device of Construction Machinery - In an over-loading prevention device including a hydraulic pump, a control valve, and a control lever, a discharge-quantity control unit performs constant-torque control which decreases a discharge quantity in proportion to an increase in a discharge pressure in the pump to control an input torque of the pump uniformly. An operation-state detection unit detects an actuation state of the control lever. A control unit outputs a control signal that sets the pump input torque to a minimum torque according to the constant-torque control, to the discharge-quantity control unit when the control lever is operated over a predetermined speed, and subsequently changes a level of the control signal to a maximum torque according to the constant-torque control in accordance with a predetermined control pattern to raise the pump input torque. | 12-03-2009 |
20090301075 | Control Apparatus for Work Machine - A speed of a hydraulic actuator is matched with that of an electric actuator when the hydraulic actuator and the electric actuator are concurrently actuated. When determination units ( | 12-10-2009 |
20090308067 | Hydraulic Drive - The present invention relates to a hydraulic drive which comprises a hydraulic motor having a first hydraulic connector and a second hydraulic connector, wherein the pressure applied at the first hydraulic connector of the hydraulic motor and the pressure applied at the second hydraulic connector of the hydraulic motor are each separately adjustable. | 12-17-2009 |
20100011757 | Safety Device for Hydraulic Working Machine - There are provided: control valves | 01-21-2010 |
20100031650 | CONSTRUCTION MACHINE AND METHOD OF CONTROLLING CONSTRUCTION MACHINE - The present invention provides a construction machine where overheating of mounted electric devices can be prevented properly with a simple structure and a method of controlling the construction machine. For this purpose, a pump target discharge flow rate of a hydraulic pump is calculated based on an operated amount of an operating unit, a temperature of an electric device mounted on the construction machine is detected, an engine minimum speed, which is a minimum possible speed of an engine in carrying out low-speed matching for matching output of the engine and pump absorbing horsepower of the hydraulic pump to each other in a low-speed region where speed of the engine is lower than set speed, is calculated by using the detected temperature of the electric device, and a maximum value out of a corresponding speed of the pump target discharge flow rate and the engine minimum speed is generated as a candidate for an engine target speed. | 02-11-2010 |
20100083651 | Circuit for controlling a double-action hydraulic drive cylinder - Circuit for controlling a double-action hydraulic drive cylinder includes a directional control valve having working ports A and B, a pump port P, and a tank port T, wherein the directional control valve has a neutral position in which pump port P is blocked and working ports A, B are connected to tank port T. A pressure-limiting valve and a controllable load-holding valve are connected to the piston space in parallel, and a regeneration check valve is connected in series between a connection point for the parallel components and the rod space. A first precharge valve is connected between the working port A and the connection point, and a first bypass check valve is connected anti-parallel parallel with the first precharge valve and the load-holding valve. A second precharge valve is connected in series with the directional control valve between the tank port P and the rod space. | 04-08-2010 |
20100095665 | Hydrostatic pump and motor with improved torque reversal characteristics - A system and method for variator control employs positively directed electronic make-up and flushing relief valves for more precise torque control of a hydraulic variator, especially during torque reversal, as well as improved cold weather operation. This can improve machine response during periods of severe torque change. The ability to more tightly control variator torque allows more precise torque management algorithms for power control and engine matching purposes. Moreover, the ability to positively control venting of the hydraulic circuit for purposes of fluid cooling allows for more consistent machine response regardless of ambient temperature. | 04-22-2010 |
20100101223 | FLOW COMPENSATED RESTRICTIVE ORIFICE FOR OVERRUNNING LOAD PROTECTION - A hydraulic circuit for an actuator that has a piston and piston rod that will move a load in a first direction, and which can be externally loaded in an opposite direction, includes a flow compensated valve between the actuator and a control valve. When the piston in the actuator is moved in the second opposite direction under the external load and the rate of flow of fluid out of the actuator through the flow compensated valve exceeds a selected rate, an orifice is introduced in the flow path to restrict flow from the actuator. | 04-29-2010 |
20100154404 | HYDRAULIC SYSTEM - A hydraulic system includes an engine driven adjustable hydraulic pump which supplies fluid to a hydraulic consumer, and an electronic control unit. The adjustable pump includes flow controller for controlling a pressure difference between the consumer and the adjustable pump to a pre-determined control pressure difference. The flow controller includes an actuator controlled by the control unit, through which the pressure difference can be controlled. The electronic control unit receives an engine speed signal and controls the actuator to control the pressure difference, in order to make power delivery of the adjustable pump conform to the operating conditions of a vehicle. | 06-24-2010 |
20100170238 | SYSTEM AND METHOD FOR THE TEMPERATURE REGULATION OF A HYDRAULIC FLUID - The present invention provides a device and a method for regulating a temperature (T) of hydraulic fluid in at least one hydraulic circuit ( | 07-08-2010 |
20100170239 | HYBRID WORKING MACHINE - In a hybrid working machine in which the maximum engine output is set at the average power and the maximum pump input is set to be larger than the maximum engine output in a normal state, in an abnormal state in which the level of charge of a battery decreases and assistance ability of a motor function of a power machine is lost, the minimum pump flow rate is reduced to a value equal to or smaller than a standby flow rate, the standby flow rate being the minimum pump flow rate used in normal state control, and a set value of the maximum pump input is changed such that the maximum pump input is smaller than the maximum engine output. | 07-08-2010 |
20100186404 | CONTROL DEVICE FOR INDUSTRIAL VEHICLE - A control device for an industrial vehicle including an electric storage device, a load device, a hydraulic pump, and a load motor is disclosed. The electric storage device stores regenerative power generated through regenerative braking performed by the travel motor. The hydraulic pump supplies a hydraulic circuit with hydraulic oil to operate the load device. The load motor drives the hydraulic pump. The control device includes a power control unit and a resistance flow passage. The power control unit executes control for supplying the load motor with the regenerative power when the electric storage device is in a fully charged state during regenerative braking performed by the travel motor. The resistance flow passage is arranged in the hydraulic circuit and enables passage of hydraulic oil while applying flow resistance to the hydraulic oil. When the electric storage device is in the fully charged state during regenerative braking performed by the travel motor and, at the same time, the load device is not performing a load handling operation, the hydraulic oil supplied from the hydraulic pump is guided to the resistance flow passage. | 07-29-2010 |
20100218494 | Pump Control Apparatus for Hydraulic Work Machine, Pump Control Method and Construction Machine - A pump control apparatus for a hydraulic work machine includes: a rotation speed setting device that sets a target rotation speed for an engine; a rotation speed control device that controls an engine rotation speed so as to adjust the engine rotation speed to the target rotation speed; a first variable hydraulic pump used to drive a work hydraulic actuator, driven by the engine; a second variable hydraulic pump used to drive a cooling fan, driven by the engine; and a pump control device that controls an output flow rate of the first variable hydraulic pump and an output flow rate of the second variable hydraulic pump so as to ensure that a sum of an intake torque of the first variable hydraulic pump and an intake torque of the second variable hydraulic pump does not exceed an engine output torque determined in advance based upon the target rotation speed. The pump control device a) controls the output flow rate of the second variable hydraulic pump based upon the target rotation speed and a target output flow rate of the second variable hydraulic pump assuring a required cooling air volume at the cooling fan; and b) regulates the intake torque of the first variable hydraulic pump by calculating the intake torque of the second variable hydraulic pump and subtracting the intake torque of the second variable hydraulic pump from the engine output torque determined in advance based upon the target rotation speed. | 09-02-2010 |
20100236234 | HYDRAULIC VALVE DEVICE - A Hydraulic valve device includes a first engine port and a second engine port to a double acting hydraulic motor, and a pump, a hand valve, which is arranged such that it connects the engine ports to the tank and the pump, and which hand valve has two open positions, wherein the pump in the first open position via a line is connected to the first engine port and the tank via a line is connected to the second engine port, and wherein the pump in the second open position via the line is connected to the second engine port and the tank via the line is connected to the first engine port, and a first nonreturn valve, arranged between the pump and the second engine port and opens towards the second engine port. A piston which by way of the load pressure in the first engine port via a line governs the first nonreturn valve, such that it is kept closed as long as the pump pressure does not exceed the load pressure, and a second nonreturn valve arranged such that it, as long as the hand valve is in its first open position, connects the first engine port to the second engine port and opens in direction towards the second engine port. | 09-23-2010 |
20100263362 | METHOD FOR CONTROLLING A WORKING MACHINE - A method for controlling a working machine including a hydraulic system for controlling a plurality of work functions, including lift and tilt of an implement, includes the steps of determining a maximum pressure of a hydraulic fluid for performing a certain task with the implement individually for at least one of the work functions, and delivering the hydraulic fluid, pressurized at most to the determined maximum pressure, to the work function. | 10-21-2010 |
20100263363 | HYDRAULIC CONTROL DEVICE AND PRESSURE SWITCH - In a hydraulic control device H comprising a pressure source P which can be switched on and switched off, a reservoir R and a pressure switch W located in a discharge path | 10-21-2010 |
20100281859 | OIL PRESSURE SYSTEM AND VALVE ASSEMBLY USED IN OIL PRESSURE SYSTEM - In the oil pressure system, a control unit sets a flow passage changeover valve to be in a merging state, and sets a relief pressure to a low relief pressure via a relief pressure changeover unit in the case that the rotational speed of the engine is lower than a predetermined threshold level. Also, the control unit sets the flow passage changeover valve to be in a branching state, and sets the relief pressure to a high relief pressure via the relief pressure changeover unit in the case that the rotational speed of the engine is the predetermined threshold level or higher. | 11-11-2010 |
20100319337 | HYDROSTATIC DRIVE SYSTEM - The invention relates to a hydrostatic drive system having a pump ( | 12-23-2010 |
20110047999 | CONTROL UNIT OF HYDRAULIC BRAKE APPARATUS FOR VEHICLE - A control unit of a hydraulic brake apparatus for a vehicle including a housing, a switching control valve, pressure increase control valves, pressure decrease control valves, a reservoir, a pump driven by a motor, a first passage, a second passage, an inner bore and a passage forming member being liquid-tightly fitted into the inner bore in order to form an extended ring-shaped passage, wherein the extended ring-shaped passage forms a part of the first passage, and the switching control valve, the pressure increase control valves and the outlet valve are connected to the extended ring-shaped passage, and a part of the second passage is formed within the passage forming member, and end portions of the part of the second passage are connected to the switching control valve and the switching valve. | 03-03-2011 |
20110072811 | ENGINE DRIVEN LIFT GATE POWER SYSTEM - A power system for a lift gate is provided. The power system includes an actuator system including an actuator for a lift gate, and a lift gate engine coupled to the actuator system. The lift gate engine is configured for generating kinetic energy from a fuel source to power the actuator system for operating the lift gate. | 03-31-2011 |
20110146260 | HYDRAULIC SYSTEM HAVING A HYDROSTATIC, VALVE-CONTROLLED PISTON ENGINE - The invention relates to a hydraulic system, having a hydrostatic, valve-controlled piston engine with a plurality of valves actuatable by an actuator as a function of the motion of the pistons, and with a control unit for triggering the actuators, which is arranged for generating an electrical attraction current in a first time segment and a maintenance current in a second time segment. The object of the invention is for the valves to switch with quick reactions and function safely, so that the expected functionality and safe operation of the hydrostatic piston engine under various operating conditions is ensured. This is attained in that the control unit includes a current regulating device, which triggers the actuators in current-regulated fashion. | 06-23-2011 |
20110146261 | SYSTEM AND METHOD FOR CONTROLLING AN ELECTRO-HYDRAULIC CHARGING SYSTEM - The disclosure describes, in one aspect, a control system for charging an electro-hydraulic charging system. The control system including at least one sensor operatively coupled to an engine for sensing at least one engine parameter indicative of an operating status of the engine and a controller adapted to charge the charging system when the operating status of the engine is determined to be stable. | 06-23-2011 |
20110154815 | SWING MOTOR CONTROL METHOD IN OPEN CENTER TYPE HYDRAULIC SYSTEM FOR EXCAVATOR - A swing motor control method in an open center type hydraulic system for a hydraulic excavator is provided, which can adjust the speed of a swing motor so that a swing device and a working device harmonize with each other according to a discharge pressure of a hydraulic pump during a multifunctional work of the working device and the swing device. The swing motor control method in an open center type hydraulic system for an excavator including first and second hydraulic pumps, a swing motor, a working device actuator including a boom or arm actuator, a working device control valve controlling a start, a stop, and a direction change of the working device actuator, a discharge pressure sensor sensing the discharge pressure of the second hydraulic pump, and a swing motor controller controlling a speed of the swing motor in accordance with the pressure detected by the discharge pressure sensor, includes controlling the speed of the swing motor during a multifunctional operation of the swing device and the working device, comparing the pressure detected by the hydraulic pump discharge pressure sensor with a preset pump discharge pressure, and controlling a limiting speed of the swing motor in accordance with the result of comparison. | 06-30-2011 |
20110225962 | Variable Speed Hydraulic Pump Apparatus and Method - An embodiment in accordance with the present invention provides a hydraulic pump including a first motor running at a fixed speed, a reservoir for fluid and a first pump operatively coupled to the motor such that the pump runs at the same speed as the motor and generates a flow of fluid from the reservoir. The hydraulic pump further includes a second motor, a speed control valve operatively coupled to the to the first pump and operatively coupled to the second motor such that a portion of the flow is directed to the second motor and the remainder of the flow is diverted to the reservoir, and a second pump operatively coupled to the second motor such that the second pump is driven by the second motor. | 09-22-2011 |
20110225963 | ACTUATOR FOR GAS-OPERATED EMERGENCY OPENING OF AN OPENABLE ELEMENT OF AN AIRCRAFT, HAVING MEANS FOR VENTING THE GAS - Actuator for emergency opening of an openable element (Co) of an aircraft, having:
| 09-22-2011 |
20120011841 | HYDRAULIC DEVICE FOR STEPLESS TRANSMISSION - A hydraulic device includes a switch-over valve | 01-19-2012 |
20120011842 | HYDRAULIC TRANSMISSION CONTROL - A hydraulic transmission unit comprises at least one pressure regulation valve ( | 01-19-2012 |
20120031089 | Axial Bearing For Use In A Hydraulic Device, A Hydraulic Transformer And A Vehicle With A Hydraulic Drive System - An axial bearing between a first part and a second part that presses with an axial load against the first part and can rotate around a rotation axis relative to the first part comprising a circular or arc-shaped ridge on the first part centered around the rotation axis, a pressure source for providing pressurized hydraulic fluid on a first side of the circular or arc-shaped ridge, an adjustable gap between the circular or arc shaped ridge and a bearing surface on the second part, wherein the pressurized hydraulic fluid flows through the adjustable gap to a second side of the circular or arc-shaped ridge. In accordance with the invention the circular or arc-shaped ridge or the bearing surface include a ridge chamber for locally creating a larger adjustable gap between the circular or arc-shaped ridge and the bearing surface. | 02-09-2012 |
20120036845 | HYDRAULIC CONTROL APPARATUS FOR WORK MACHINE - A hydraulic pump driven by an engine, a hydraulic actuator, and a negative control circuit are provided on an open center hydraulic circuit, for guiding the hydraulic pressure in the center bypass to the hydraulic pump, as a negative control pressure. A negative control pressure control device controls the negative control pressure to an arbitrary value is also provided. The pump characteristic of the hydraulic pump is set such that the discharge flow rate is minimized when the negative control pressure in the negative control circuit is equal to or greater than a first predetermined pressure. Furthermore, an idling detection device that detects whether the hydraulic actuator is in a non-operated state or not is provided. The negative control pressure is forcefully controlled to the first predetermined pressure or higher when the non-operating state is detected. | 02-16-2012 |
20120060486 | HYDRAULIC CONTROL DEVICE, CONTROL METHOD OF THEREOF, AND AUTOMATIC TRANSMISSION - A hydraulic control circuit includes an oil pump for generating a hydraulic pressure by being rotated by power of a driving force source, a line pressure oil passage in which at least a line pressure generated by adjusting the hydraulic pressure generated by the oil pump is supplied, a driving force source stopping unit that stops the rotation of the driving force source, and a hydraulic pressure reduction suppressing unit that is provided in the line pressure oil passage and suppresses a reduction of the line pressure accompanying reverse rotation of the driving force source when the rotation of the driving force source is stopped by the driving force source stopping unit. | 03-15-2012 |
20120067039 | INDUSTRIAL MACHINE - A three-dimensional measuring machine (industrial machine) includes an air supplier supplying air; a drive mechanism driven by the air supplied from the air supplier; an electromagnetic valve provided inside an air regulator set to open and close an air supply passage inside the air regulator set, the air regulator set introducing the air from the air supplier to the drive mechanism; and a motion controller controlling the electromagnetic valve to block the air supply passage when a time since the drive mechanism stopped operation reaches a preset time. | 03-22-2012 |
20120073282 | HYDRAULIC SYSTEM - A hydraulic system, especially in a high-pressure application, comprises a pressurized-fluid tank, a pressurized-fluid pump driven by a drive unit, at least one hydraulic load that can be pressurized thereby and a control and/or distribution unit connected fluidically between the pressurized-fluid pump and the load. This unit is provided with a housing and a core received therein and connected rigidly with the housing, which core bears with part of its surface in the region of a common, closed, especially cylindrical joint face with the housing on a corresponding inside face of a housing opening. Surface groove-like flow ducts are provided on the core and/or the housing in the region of the joint face, and the pressurized-fluid pump is directly built onto the control and/or distribution unit in the region of a free end face of the core. | 03-29-2012 |
20120131913 | HYDRAULIC SWING-CONTROLLING APPARATUS OF WORK MACHINE - In a work machine including a hydraulic pump ( | 05-31-2012 |
20120144818 | POWER TRANSMISSION DEVICE - A power transmission device that transmits power from a motor to a wheel via a hydraulically driven friction engagement element and that includes a mechanical pump driven by the motor to produce a hydraulic pressure that is regulated by a pressure regulating valve; an electric pump that produces a hydraulic pressure; a switching mechanism that either switches an output pressure of the regulating valve or an output pressure of the electric pump to a servo of the engagement element based upon a signal pressure, and a drain valve that opens to drain oil when a hydraulic pressure of a preset pressure or more is applied, and the switching mechanism connects to the drain valve to allow communication between the electric pump and the drain valve in the first state, and shut off communication between the electric pump and the drain valve. | 06-14-2012 |
20120144819 | HYBRID WORKING MACHINE - A hybrid working machine includes an engine, an assist motor configured to assist the engine, a hydraulic pump driven by the engine, an electric power accumulating unit configured to feed the assist motor with electric power, an electric-discharge electric motor configured to perform power running with electric power of an electric power accumulator of the electric power accumulating unit, an electric-discharge hydraulic motor connected to the electric-discharge electric motor, and a hydraulic circuit configured to control driving of the electric-discharge hydraulic motor. The hydraulic circuit includes a circulation circuit configured to be connected to a hydraulic feed port and a hydraulic discharge port of the electric-discharge hydraulic motor and a selector valve configured to perform such switching as to connect the electric-discharge hydraulic motor to the circulation circuit at a time of performing an electric discharge operation. | 06-14-2012 |
20120151910 | VARIABLE PRESSURE CONTROL SYSTEM FOR DUAL ACTING ACTUATORS - A variable pressure control system for varying pressures in the fluid circuits of a dual acting actuator over a range of pressures. The variable pressure control system includes a controller that cooperates with pressure regulators for regulating the desired pressure in the fluid circuits. | 06-21-2012 |
20120151911 | COMBINATION OF A CHAMBER AND A PISTON, A PUMP, A MOTOR, A SHOCK ABSORBER AND A TRANSDUCER INCORPORATING THE COMBINATION - A combination of a piston and a chamber, wherein the chamber defines an elongate chamber having a longitudinal axis, the chamber having, at a first longitudinal position thereof, a first cross-sectional area thereof and, at a second longitudinal position thereof, a second cross-sectional area, the second cross-sectional area being 95% or less of the first cross-sectional area, the change in cross-section of the chamber being at least substantially continuous between the first and second longitudinal positions, the piston being adapted to adapt itself to the cross-section of the chamber when moving from the first to the second longitudinal position of the chamber. The piston may comprise an umbrella-like support structure or a fiber enforced deformable container comprising a foam or a fluid. The combination may be used in a pump, a linear actuator, a motor, or a shock absorber. | 06-21-2012 |
20120198832 | Hydraulic System for a Work Vehicle - A hydraulic system for a work vehicle is disclosed. A preferential flow-dividing valve supplies a fixed amount of oil discharged from a variable displacement pump preferentially to a preferential hydraulic oil section and a surplus oil flow from the pump to a non-preferential hydraulic oil section. A plurality of electromagnetic proportional control valves are provided in the non-preferential hydraulic oil section for controlling oil flows relative to a plurality of hydraulically operated devices provided in the non-preferential hydraulic oil section. A necessary flow rate calculating module calculates a necessary oil flow rate in each of the preferential hydraulic oil section and the non-preferential hydraulic oil section based on a preferential oil flow rate of the preferential flow-dividing valve supplied to the preferential hydraulic oil section and an amount of current distributed to each of the plurality of electromagnetic proportional control valves in the non-preferential hydraulic oil section. | 08-09-2012 |
20120247095 | HYDRAULIC PRESSURE CONTROL DEVICE - A hydraulic pressure control device including a pump driven to generate hydraulic pressure; a first pressure regulation valve that regulates hydraulic pressure in a first passage coupled to a pump along with discharge of oil; a second pressure regulation valve that receives the hydraulic pressure in the first passage and regulates the hydraulic pressure to an engagement pressure to engage a lock-up clutch according to a first signal pressure to output the engagement pressure to a second passage that supplies the oil to an engagement chamber; and a third pressure regulation valve that receives the hydraulic pressure in the first passage or the engagement pressure output to the second passage and regulates the received pressure according to the first signal pressure or a second signal pressure that synchronizes with the first signal pressure to output the resulting pressure to a third passage that supplies the oil to the disengagement chamber. | 10-04-2012 |
20120255293 | HYDRAULIC SYSTEM HAVING FIXABLE MULTI-ACTUATOR RELATIONSHIP - A hydraulic system for a mobile machine is disclosed. The hydraulic system may have a first actuator, a first valve arrangement, a second actuator, and a second valve arrangement. The hydraulic system may also have at least one operator interface device movable by an operator to generate a first signal indicative of desired work tool movement in a first manner, and a second signal indicative of desired work tool movement in a second manner; and a controller configured to generate a first flow rate command directed to the first valve arrangement based on the first signal, and generate a second flow rate command directed to the second valve arrangement based on the second signal. The controller may also be configured to selectively generate a third flow rate scaled from the first flow rate command and directed to the second valve arrangement based on only the first signal. | 10-11-2012 |
20120279211 | PUMP CONTROL OPERATING SYSTEM OF CONSTRUCTION MACHINE - The present disclosure is a construction machine, such as an excavator, which comprises a plurality of hydraulically driven actuators, in which some of the actuators are provided in a one-to-one pump system where hydraulic pumps are connected to the respective actuators such that a working fluid is supplied from the respective pumps, and the remaining actuators are provided in an auxiliary control valve system where the working fluid is distributed by an auxiliary control valve connected to one or more pumps. When an amount of the working fluid of an actuator associated with the auxiliary control valve is insufficient, the actuator associated with the auxiliary control valve is connected to a pump of the one-to-one pump system to share the pump of the one-to-one pump system. | 11-08-2012 |
20120304636 | HYDRAULIC FAN CIRCUIT - A hydraulic fan circuit includes a primary pump, a motor fluidly connected to the primary pump, and a fan operably connected to and driven by the motor. The circuit also includes a supply passage extending from the primary pump to the motor, a return passage extending from the motor to the primary pump, and a pressure limiting valve configured to selectively reduce pressure of a flow of pilot fluid directed to the primary pump. The circuit further includes an override valve configured to selectively connect the supply passage to the pressure limiting valve. | 12-06-2012 |
20120312007 | CONTROL SYSTEM FOR HYBRID CONSTRUCTION MACHINE - A control system for construction machine includes a pair of first and second main pumps which are variable-displacement pumps, first and second circuit systems connected to the first and second main pumps and including a plurality of control valves, main switching valves provided between the first and second circuit systems and the first and second main pumps, a hydraulic motor for power generation connected to the first and second main pumps via the main switching valves, a generator coupled to the hydraulic motor for power generation, and a battery for storing power generated by the generator. When at least the main switching valve connected to one circuit system is at a position to cause one main pump connected thereto to communicate with the hydraulic motor for power generation, the main switching valve connected to the other circuit system causes the other main pump to communicate with the other circuit system. | 12-13-2012 |
20130055705 | HYDRAULIC DRIVE SYSTEM FOR CONSTRUCTION MACHINE - A hydraulic drive system for a construction machine has a travel detection device which detects whether or not the operation mode is a traveling operation and a setting changing device. The setting changing device sets the target differential pressure of load sensing control at an absolute pressure Pa when the operation mode is not a traveling operation, and sets the target differential pressure of the load sensing control at an absolute pressure Pa′ rather than the absolute pressure Pa. In this way, in the actuator operation other than traveling, a necessary actuator speed can be obtained and supplied with the necessary maximum flow rate. In addition, during the combined operation, a flow rate in accordance with the opening area ratios of flow control valves can be distributed to actuators different in load pressure from one another; and energy efficiency is enhanced due to less energy loss during traveling operation. | 03-07-2013 |
20130086899 | HYDRAULIC SYSTEM WITH BI-DIRECTIONAL REGENERATION - A hydraulic actuator system including an actuator and a valve assembly configured for bi-directional regeneration. The actuator may include a hollow body and a rod disposed within and extending outwardly from the hollow body. The rod may include a first chamber within the rod and a piston disposed at one end of the rod, defining a second chamber and a third chamber within the hollow body. A valve assembly may be in fluid communication with a first conduit, a second conduit, the first chamber, the second chamber, and the third chamber, wherein the valve assembly is configured to selectively couple one of the first conduit and the second conduit to one or more of the first port, the second port, and the third port, wherein one of the first conduit and the second conduit is configured as a pressure source. | 04-11-2013 |
20130098026 | Hydraulic Fluid Actuated Equipment Leveling Assembly - A hydraulic fluid actuated equipment leveling assembly incorporating a plenum having adjustment ports; an input channel opening the plenum; a disk valve operable for opening and closing the adjustment ports; telescoping and hydraulic ram actuated equipment support pedestals; hydraulic lines spanning between the plenum's adjustment ports, and the pedestal's hydraulic rams; and fluid displacing plungers connected operatively to the hydraulic lines for adjusting the hydraulic line's interior volumes. | 04-25-2013 |
20130111892 | MIXER DRUM DRIVING DEVICE - A mixer drum driving device includes a hydraulic motor that rotates a mixer drum, a first hydraulic pump that is driven by an engine to be capable of supplying working oil to the hydraulic motor, an electric motor, a power supply connected to the electric motor, a second hydraulic pump capable of supplying the working oil to the hydraulic motor on the basis of a driving force of the motor, and a flow dividing valve that divides the working oil discharged from the first hydraulic pump and supplies the working oil to the hydraulic motor and the second hydraulic pump. The second hydraulic pump is configured to rotate the electric motor using the working oil. The electric motor is configured to generate electric power so as to charge the power supply when driven to rotate by the second hydraulic pump. | 05-09-2013 |
20130118160 | METHOD AND DEVICE FOR CONTROLLING POWER OUTPUT OF ENGINE FOR WORKING MACHINE - An engine control device detects the state of work of a working vehicle such as a construction machine or the like, and controls the power output capacity of an engine automatically. A determination is made as to whether excavation or uphill traveling is being performed, based upon the detection signals from a hydraulic oil pressure detector for a hydraulic cylinder of an arm, detectors for arm and bucket operation commands, a shift operation detector for a transmission, a pitch angle detector for the vehicle body, a traveling acceleration detector, and an accelerator opening degree detector. When the result of this determination is that excavation or uphill traveling is being performed, the engine is controlled to operate at a high power capacity, while at other times it is controlled to operate at a low power output capacity. | 05-16-2013 |
20130167521 | INDUSTRIAL VEHICLE - A forklift ( | 07-04-2013 |
20130205766 | Hydrostatic Transmission - A hydrostatic transmission comprises a hydraulic pump, a hydraulic motor, first and second main fluid passages fluidly connecting the hydraulic pump to the hydraulic motor so as to constitute a closed fluid circuit, a charge fluid passage, a plurality of first charge check valves and a plurality of second charge check valves. The plurality of first charge cheek valves are interposed between the charge fluid passage and the first main fluid passage so as to allow only flow of fluid from the charge fluid passage to the first main fluid passage when the first main fluid passage is hydraulically depressed relative to the charge fluid passage. The plurality of second charge check valves are interposed between the charge fluid passage and the second main fluid passage so as to allow only flow of fluid from the charge fluid passage to the second main fluid passage when the second main fluid passage is hydraulically depressed relative to the charge fluid passage. | 08-15-2013 |
20130213030 | Hydrostatic Drive System - A hydrostatic drive system includes a user in the form of a differential cylinder connected in a closed circuit to a high-pressure pump. A piston-side compression chamber and a piston-rod-side compression chamber of the differential cylinder are in communication with the high-pressure pump. The closed circuit includes a protection device having first and second protection valve devices that each includes a pressure relief valve and an anti-cavitation valve. The pressure relief valve of the first protection valve device is provided with an override device, by means of which the opening pressure of the pressure relief valve can be varied. When the high-pressure pump delivers into the piston-rod-side compression chamber, the pressure relief valve of the first protection valve device is adjusted by means of the override device to a reduced opening pressure and the differential volumetric flow flows out via the pressure relief valve to a low-pressure system. | 08-22-2013 |
20130227941 | PRESSURE INTENSIFIER FOR DISCHARGING FLUID AT CONSTANT FLOW RATE - A pressure intensifier for ejecting fluid at a constant flow rate includes a hydraulic pump, a hydraulic motor, a supply channel, a first control unit, and a second control unit. The hydraulic pump pumps an introduced fluid to eject the fluid through an ejection channel. The hydraulic motor is driven by the introduced fluid and drives the hydraulic pump to cause the fluid ejected by the hydraulic pump to be intensified. The supply channel allows the hydraulic pump and the hydraulic motor to be supplied with the fluid. The first control unit opens or closes the supply channel, and the second control unit operates the first control unit to cause the first control unit to close the supply channel if the fluid ejected through the ejection channel is larger than a predetermined pressure. | 09-05-2013 |
20130255244 | HYDRAULIC SYSTEM FOR CONSTRUCTION MACHINE INCLUDING EMERGENCY CONTROL UNIT FOR ELECTRIC HYDRAULIC PUMP - The present disclosure relates to a hydraulic system for a construction machine which uses an electric hydraulic pump, and more particularly, to a hydraulic system including an emergency control unit for temporarily driving the construction machine when an electronic control unit controlling the electric hydraulic pumps fails to operate. To this end, disclosed is the hydraulic system including the electric hydraulic pump, the electric control unit for controlling the electric hydraulic pump, and the emergency control unit, which operates when the electric control unit fails to operate, so as to temporarily control the electric hydraulic pump in accordance with to a predetermined condition, which can effectively respond to a low load work corresponding to predetermined pressure and to a high load work corresponding to higher pressure, by selectively operating the emergency control unit according to different optional conditions, based on the amount of load (low load, high load) of the working machine that is required when the electric control unit fails to operate. | 10-03-2013 |
20130263586 | HYDRAULIC CONTROL SYSTEM IN A CONTINUOUSLY VARIABLE TRANSMISSION - A hydraulic control system in a continuously variable transmission ( | 10-10-2013 |
20130263587 | Relief Pressure Control Device for Hydraulic Work Machine - A relief pressure control system is provided with a controller for outputting, responsive to an adjustment signal output from a dial switch, a control signal to control a relief pressure of a variable solenoid relief valve, a display unit for displaying, responsive to display signals outputted from the controller, a relationship between a circuit pressure output from a pressure sensor and a pressure required by a hydraulic cylinder, and a control device constituting a start instruction unit for instructing a start of control of the variable solenoid relief valve. Stop valves are arranged in sections of main lines, which communicate a directional control valve and the hydraulic cylinder with each other, to open or close the section. The sections are located between positions on the main lines, where the variable solenoid relief valves are connected to the main lines, respectively, and the hydraulic cylinder. | 10-10-2013 |
20130283776 | ENERGY-RECOVERY GENERATION SYSTEM FOR HANDLING AND CARRYING ELECTRIC VEHICLE - An energy-recovery generation system for a handling and carrying electric vehicle, comprising a hoisting cylinder ( | 10-31-2013 |
20130291531 | HYBRID EXCAVATOR BOOM ACTUATING SYSTEM AND METHOD FOR CONTROLLING SAME - The present disclosure relates to a hybrid excavator boom actuating system and to a method for controlling the same. The boom actuating system comprises: an electric motor serving as a motor or a generator; an ultra capacitor for storing electricity generated by the electric motor; a hydraulic pump motor driven by the electric motor to supply hydraulic fluid to a boom; a boom control valve which has a closed circuit for selectively connecting or disconnecting an outlet line and an inlet line of the hydraulic pump motor to or from a head or a rod side of the boom; a main pump driven by the engine to supply hydraulic fluid to a bucket, a travel motor or an arm; a motor bypass valve connected to the outlet line and the inlet line to interconnect the outlet line and the inlet line or disconnect the outlet line from the inlet line; and a controller for controlling the electric motor, the hydraulic pump motor, the boom control valve and the motor bypass valve. | 11-07-2013 |
20130312401 | Pilot Pressure Supply System - A pressurised fluid supply system for an agricultural vehicle ( | 11-28-2013 |
20130312402 | HYDRAULIC SYSTEM FOR WORK MACHINE - Provided is a hydraulic system for a work machine, which can ensure low temperature responsiveness of remote control valves that perform pilot operations of pilot operated directional control valves for controlling hydraulic actuators, respectively. In order to, with bringing an unloading valve V | 11-28-2013 |
20130318958 | CONTROL VALVE ASSEMBLY - A power machine and a power conversion system for a power machine are disclosed. In an exemplary embodiment, the power conversion system includes a pump configured to provide a source of pressurized hydraulic fluid and a control valve assembly to receive the hydraulic fluid. The control valve assembly includes a first valve element configured to direct hydraulic fluid to an actuator when the first valve element is in first and second actuated positions. The control valve assembly also includes a second valve element downstream of the first spool. The first valve element is moveable between an unactuated position and the first and second actuated positions and is configured to direct hydraulic fluid received from the actuator through the second actuated position to the second valve element and to direct hydraulic fluid received from the actuator through the first actuated position to bypass the second valve element. | 12-05-2013 |
20130318959 | Hydraulic Circuits with Energy Conservation Features for Overrunning Load Conditions - A hydraulic system is disclosed that includes a hydraulic actuator having a head end, a rod end and a piston disposed therebetween. The system also includes a pump configured to supply fluid to both ends of the actuator. The system also includes an energy conservation system that is configured to reduce flow from the pump to the head end of the actuator and to increase flow from a make-up fluid circuit to the head end of the actuator during an overrunning load condition. The energy conservation system also increases flow from the pump to the head end of the actuator and decreases flow from the make-up circuit to the head end of the actuator after the overrunning load condition has ceased. | 12-05-2013 |
20130327032 | Hydraulic System and Arrangement for an Access Arrangement - A hydraulic system for an access arrangement having a platform configured for movement between a deployed position and a stowed position, the hydraulic system including: at least one hydraulic power unit configured to urge hydraulic fluid through a hydraulic circuit; at least one hydraulic cylinder directly or indirectly connected to a portion of the platform and configured to urge the platform towards at least one of the stowed position and the deployed position, wherein the at least one hydraulic cylinder is in fluid communication with the hydraulic power unit; and a pressure regulating valve in a path between the at least one hydraulic power unit and the at least one hydraulic cylinder, wherein the pressure regulating valve is operable to prevent the at least one hydraulic cylinder from urging the platform to the stowed position if a load on the platform exceeds a specified threshold. | 12-12-2013 |
20140026552 | HYBRID CONSTRUCTION MACHINE - The axial lengths of coupling portions of a flywheel, a rotor shaft, and a pump shaft are reduced to reduce the axial length of an entire power unit. A crankshaft and a flywheel are directly coupled to each other and the flywheel and a rotor shaft are directly coupled to each other. A coupling is directly coupled to an end face of the rotor shaft on the opposite side to the flywheel. A pump shaft is connected to the coupling. Coupling surfaces of the flywheel and the rotor shaft and coupling surfaces the rotor shaft and the coupling are arranged within a width range of a coil. | 01-30-2014 |
20140053543 | HYDRAULIC VALVE DEVICE - A hydraulic valve device includes a first and a second engine port to a double acting hydraulic motor, a pump, a hand valve which has two open positions, wherein in the first open position the pump is fluidly connected to the first engine port and the tank is fluidly connected to the second engine port; and wherein in the second open position the pump is fluidly connected to the second engine port and the tank is fluidly connected to the first engine port, with a first nonreturn valve, arranged between the pump and second engine port. A piston which by way of the load pressure in the first engine port via a line governs the first nonreturn valve, and a second nonreturn valve arranged, as long as the hand valve is in its first open position, to connect the first engine port to the second engine port. | 02-27-2014 |
20140060034 | Electro-Hydraulic Control Design for Pump Discharge Pressure Control - An electro-hydraulic control system manages speed of a hydraulic fan by using a solenoid to bias a three position pool of a control valve coupled to a hydraulic pump driving the fan. In a first position, the spool releases pressure on a de-stroke actuator of the pump and allows an on-stroke actuator to increase output pressure corresponding to a speed of an engine driving the pump. In a second position, the spool isolates the de-stroke actuator and fixes the pressure output of the pump. In a third position, the spool couples the de-stroke actuator to the pump output and causes a reduction in the pressure output of the pump. The solenoid coupled to the spool sets the output pressure at which the spool is in the second position. | 03-06-2014 |
20140083093 | VEHICLE HEIGHT ADJUSTING DEVICE FOR MOTORCYCLE - An object of the present invention is to reduce current consumption for switching and holding an actuation position of an electromagnetic change-over valve included in a vehicle height adjusting device for a motorcycle and to surely hold the actuation position. In a rear-wheel side vehicle height adjusting device for a motorcycle, after applying a startup current to a solenoid of a change-over valve in order switch an actuation position of the change-over valve, while switching an applied current to the solenoid to a holding current which is smaller than the startup current and holding the actuation position of the change-over valve, a control section intermittently applies a large current, which is larger than the holding current, to the solenoid. | 03-27-2014 |
20140090369 | Hydraulic Drive Device for Working Machine - A hydraulic drive device for a hydraulic excavator, includes: a first hydraulic pump; a first boom directional control valve and a second arm directional control valve which are connected in parallel to the first pump; a second hydraulic pump; and a second boom directional control valve and a first arm directional control valve which are connected in parallel to the second pump; wherein: the hydraulic drive device also includes: a third hydraulic pump; a third boom directional control valve connected to the third pump and controlling the flow of pressure oil supplied to a boom cylinder; and a third arm directional control valve connected in tandem with the third boom directional control valve and controlling the flow of pressure oil supplied to an arm cylinder. | 04-03-2014 |
20140123640 | CONSTRUCTION MACHINE - A construction machine including: a swivel motor; a working attachment having a boom, a boom cylinder, an arm and an arm cylinder; a hydraulic actuator circuit having a first circuit including the boom cylinder and a boom control valve, a second circuit including the arm cylinder and an arm control valve, and a third circuit including the swivel motor and a swivel control valve; first to third pumps for the first to third circuits; a merge valve having a first position for merge of third pump fluid into the first circuit and connection of an unload line of the third circuit to a tank, and a second position for prohibiting the merge; and a merge selecting control section which holds the merge valve at the first position either of when only a swivel operation is performed and when a boom raising operation is performed. | 05-08-2014 |
20140130488 | HYDRAULIC DRIVE APPARATUS FOR WORK MACHINE - Provided is a hydraulic drive apparatus for working machine capable of preventing an excessive pressure reduction on a meter-in side and moving a load in a lowering direction at a stable speed requiring no counter balance valve. The apparatus includes a hydraulic pump, a hydraulic actuator for lowering the load, an operating device, a hydraulic circuit including a meter-in flow passage, a meter-out flow passage and a regeneration flow passage, a control valve, a meter-in-flow-rate controller for controlling a meter-in flow rate, a meter-out-flow-rate controller for controlling a meter-out flow rate to one not lower than the meter-in flow rate, a back pressure generator located downstream of the regeneration flow passage in the meter-out flow passage, and a meter-out-flow-rate limiter. The meter-out-flow-rate limiter minimizes a flow passage area of the meter-out orifice when a pressure in the meter-in flow passage falls to or below a permissible pressure. | 05-15-2014 |
20140174071 | HYDRAULIC CONTROL SYSTEM FOR CONSTRUCTION MACHINERY - The present invention relates to a hydraulic control system for construction machinery capable of variably adjusting a set pressure of a relief valve, which controls a set pressure of a hydraulic system, according to a value inputted by means of pressure in the hydraulic system or the manipulation of a joystick. The hydraulic control system comprises: a flow control valve installed in a passage between a hydraulic pump and a hydraulic actuator, for controlling the driving of the hydraulic actuator by being switched by a control signal according to the manipulation of the joystick; a main relief valve installed in a passage between an upstream-side discharge passage of the hydraulic pump and a hydraulic tank, for returning a working fluid to the hydraulic tank when a high load exceeding a set pressure occurs in the system; a pressure controlling means for controlling, either continuously or in stages, a set pressure of the main relief valve; a pressure sensing means for sensing a pressure at a discharge side of the hydraulic pump; and a controller for determining the value inputted by the manipulation of the joystick, and a required set pressure for the relief valve according to the system pressure sensed by the pressure sensing means, and then outputting a control signal to the pressure controlling means to enable a set pressure of the relief valve to be variably adjusted to a determined set pressure. | 06-26-2014 |
20140190158 | HYDRAULIC CIRCUIT, AND COMBINATION VALVE USED IN SAME HYDRAULIC CIRCUIT - A composite valve is used in a hydraulic circuit. The composite valve is interposed between a stack valve and a hydraulic power supplier and between the stack valve and a multifunction valve coupled to a hydraulic device. The composite valve includes: stop valves opening/closing communication between the hydraulic power supplier and the stack valve and stop valves opening/closing communication between the stack valve and the multifunction valve; and bypass circuits respectively including stop valves opening/closing communication between the hydraulic power supplier and the multifunction valve, the bypass circuits provided closer to the hydraulic power supplier than the stop valves. This structure makes it possible to simultaneously perform various functions: repair, checking, and/or maintenance on the stack valve; flushing; and repair, checking, maintenance, and/or a trial run of the hydraulic device. The composite valve has uniform circuit configurations, which facilitates production of the valve. | 07-10-2014 |
20140196448 | HYDRAULIC CONTROL APPARATUS AND METHOD - A hydraulic control apparatus is disclosed that controls a hydraulic pump in a construction machine in which a hydraulic actuator is connected to the hydraulic pump via a directional control valve of a closed center type, and in which a position of the directional control valve is changed according to an operation amount of an operation member. The hydraulic control apparatus includes a virtual negative control pressure calculating part configured to calculate, based on the operation amount of the operation member and a discharge pressure of the hydraulic pump, a virtual negative control pressure when a negative control system is assumed; and a part configured to calculate a control command value for the hydraulic pump based on the virtual negative control pressure. | 07-17-2014 |
20140216024 | BRAKE VALVE AND HYDROSTATIC DRIVE SYSTEM THEREWITH - A brake valve is insertable into a working line of a hydrostatic travel drive. The brake valve has a main stage with a first port connected to a variable displacement pump of the drive system and a second port connected to a motor of the drive system. The main stage has a slide piston positionable in a valve bore. In a freewheeling position, a connection is maximally open with minimal throttling between the two ports. In pressure-reducing positions, a regulable, throttled connection is open from the second to the first port to brake the motor. In pressure-limiting positions, a regulable, throttled connection is open from the first to the second port to begin to throttle a pressure medium flow from the variable displacement pump to a pressure protection mechanism. The positions lie on a center line of the main stage along which the slide piston is movable. | 08-07-2014 |
20150013322 | FLUID PRESSURE CONTROL DEVICE - A fluid pressure control device includes a first control valve that switches to supply a working fluid to the pressure chamber of a cylinder on which a load pressure by the load acts so as to control the extension operation of the cylinder, a second control valve that switches to discharge the working fluid in the pressure chamber so as to control the contraction operation of the cylinder, an operate check valve that is interposed between the pressure chamber and the second control valve and that interrupts the discharge of the working fluid from the pressure chamber when the operate check valve is switched to a closed state and a pilot valve that performs, with a pilot pressure, a pilot operation on the second control valve and that switches, with the pilot pressure, the operate check valve to an opened state. | 01-15-2015 |
20150013323 | CIRCUIT PRESSURE CONTROL DEVICE, HYDRAULIC CONTROL CIRCUIT USING CIRCUIT PRESSURE CONTROL UNIT, AND HYDRAULIC CONTROL CIRCUIT OF CONSTRUCTION MACHINE - A circuit pressure control unit includes a relief valve and a variable throttle valve. The relief valve is connected to a connecting passage communicating with an actuator upstream. The variable throttle valve is disposed upstream of the relief valve and is configured to change an opening degree thereof according to a control signal from a controller. | 01-15-2015 |
20150013324 | FORKLIFT HYDRAULIC CONTROL APPARATUS - An outlet port of a hydraulic pump/motor and a bottom chamber of a lift cylinder are connected to each other by a hydraulic fluid passage. A hydraulic fluid passage that is connected to a hydraulic fluid tank is formed to branch off the hydraulic fluid passage. A flow control valve controls the hydraulic fluid delivered from the lift cylinder when the fork is lowered, thereby regulating the flow rate of hydraulic fluid supplied to the hydraulic pump/motor and the flow rate of hydraulic fluid supplied to the hydraulic fluid tank. If regenerative operation can be performed, the flow control valve is closed and hydraulic fluid is delivered to the hydraulic pump/motor. If regenerative operation cannot be performed, the flow control valve is opened and hydraulic fluid is delivered to the hydraulic fluid tank. In either case, the fork can be lowered at an instructed speed. | 01-15-2015 |
20150020516 | HYDRAULIC CIRCUIT - There is provided a hydraulic circuit which can further improve a responsive characteristic in a pressure reducing operation and a reliability in the pressure reducing operation of a relief valve device, when a main circuit pressure exceeds a predetermined pressure. | 01-22-2015 |
20150121860 | Hydraulic Drive Circuit - A hydraulic drive circuit is provided that can achieve high responsiveness, high precision, and high efficiency at a low cost in a hydraulic drive system popularly used in an industrial machine such as a press machine, a construction machine, and the like. | 05-07-2015 |
20150128584 | HYDRAULIC SOFT START SYSTEM - A hydraulic soft-start system includes a flow control valve which is in fluid communication with a pressure source and an inlet of a motor. The system includes a first flow restricting orifice and a second flow restricting orifice disposed between a pilot for actuating the flow control valve and the inlet of the motor. A first flow is passed from the pressure source via the first orifice to an inlet of the motor, placing the motor in a partially-actuated state. The flow control valve is actuated after a threshold pressure of the pilot is reached allowing a second flow to pass from the pressure source to the motor inlet. The second flow is higher than the first flow, thereby placing the motor in a fully-actuated state. | 05-14-2015 |
20150300379 | CYLINDER CONTROL DEVICE - In a cylinder control device comprising a control valve that controls a flow of working fluid flowing between a cylinder and a pump, the control valve includes a spool provided in a main body portion, a sleeve that is provided in the main body portion opposite each of two end portions of the spool, and includes a communicating port that communicates with a valve chamber, a communicating passage that communicates with a cylinder chamber, and a throttle passage that communicates with the cylinder chamber, a valve body provided in the sleeve to control a communication state between the communicating port and the communicating passage and throttle passage in accordance with a sliding position thereof, and a biasing member that biases the valve body in a valve closing direction. | 10-22-2015 |
20150369263 | ACTUATOR UNIT - An actuator unit includes two chambers defined in the cylinder; a supply passage allowing a working fluid discharged from the pump to be supplied to the two chambers; a discharge passage allowing the two chambers to communicate with the tank; a direction control valve configured to selectively communicate each of the two chambers with one of the pump and the tank; a control passage that branches from the supply passage on a side of the pump rather than the direction control valve so as to communicate the pump with the tank; a variable relief valve provided on the control passage, the variable relief valve opening so as to allow the working fluid to flow from the supply passage toward the tank when a pressure in the supply passage reaches the valve opening pressure; and a center passage that communicates the tank with an interior of the cylinder. | 12-24-2015 |
20160010669 | HYDRAULIC DEVICE AND PRIME MOVER DEVICE | 01-14-2016 |
20160069447 | HYDRAULIC CIRCUIT FOR THE TRANSMISSIONS OF INDUSTRIAL AND AGRICULTURAL VEHICLES - A hydraulic circuit for the transmissions of industrial and agricultural vehicles. The circuit comprises a feed pump driven by an internal combustion engine; a lubricating circuit; a main pressure regulator capable of bringing about a first change in the pressure of the working fluid in the circuit, this change in pressure being capable of regulation in relation to a first regulation pressure; a maximum pressure regulator for the lubrication circuit capable of bringing about a second change in pressure of the working fluid depending upon a second regulating pressure; and means for regulating regulation of the first and second regulating pressures. | 03-10-2016 |
20160084274 | SYSTEM TO PUMP FLUID AND CONTROL THEREOF - A fluid system includes a variable-speed and/or a variable-torque pump to pump a fluid, at least one proportional control valve assembly, an actuator that is operated by the fluid to control a load, and a controller that establishes a speed and/or torque of the pump and a position of the at least one proportional control valve assembly. The pump includes at least one fluid driver that provides fluid to the actuator, which can be, e.g., a fluid-actuated cylinder, a fluid-driven motor or another type of fluid-driven actuator that controls a load. Each fluid driver includes a prime mover and a fluid displacement assembly. The fluid displacement assembly can be driven by the prime mover such that fluid is transferred from the inlet port to the outlet port of the pump. | 03-24-2016 |
20160091002 | FLOW RATE SETTING SYSTEM OF WORKING MACHINE - A flow rate setting system of a working machine, includes: an attachment configured to be attached to the working machine; a control part configured to control a flow of hydraulic operation fluid based on a maximum flow rate of the hydraulic operation fluid being to be supplied to the attachment, the control part being mounted on the working machine; and a mobile terminal configured to communicate in wireless communication, the mobile terminal including: a first obtaining part configured to obtain identification information, the identification information being used for identifying the attachment; a second obtaining part configured to obtain the maximum flow rate of the attachment; and an output part configured to output the identification information and the maximum flow rate to the working machine in the wireless communication, the identification information being obtained by the first obtaining part, the maximum flow rate being obtained by the second obtaining part. | 03-31-2016 |
20160186787 | FORESTRY GRAPPLE WITH HIGH PRESSURE PROTECTION SYSTEM - A hydraulic control system for a work implement is provided. The hydraulic control system includes first hydraulic circuit and second hydraulic circuit. The first hydraulic circuit includes a selector valve and a pair of hydraulic cylinder assembly. Each hydraulic cylinder assembly includes a head end, a rod end, a cylinder, and a rod. The selector valve is configured to operate in neutral position and at least one operating position to selectively connect either the head end or the rod end to a fluid source, and the other of the head end or the rod end to fluid tank. The second hydraulic circuit includes a counterbalance valve and a shuttle valve. The counterbalance valve selectively connects the head end to the fluid tank. The shuttle valve is configured to maintain predefined pressure at relief side pressure port of the counterbalance valve to maintain a threshold pressure at the head end. | 06-30-2016 |