Patent application number | Description | Published |
20080312038 | Shift Control Device and Shift Control Method for Vehicle - A shift control device and a shift control method for a vehicle for reducing shift shock by taking into account the difference in vehicle speeds before and after shifting. In one of the main inventions, the clutch pressure of another clutch (forward clutch) is controlled to match a target vehicle speed to a calculated actual vehicle speed by the time of start of the connecting operation of a selected speed stage clutch. Since such control is performed so that the vehicle speed is caused to match the target vehicle speed, an actual vehicle speed change rate is held within a predetermined range in at least the instant that the connecting operation of the selected speed stage clutch is started. Also, in another one of the main inventions, as shown in FIG. | 12-18-2008 |
20090013810 | Work Vehicle Controller - A device is provided which eliminates uncomfortable operation feeling, improves the working efficiency, and reduces thermal load on a clutch and transmission shock. It is determined whether the current travel direction of the vehicle body is a forward travel direction F or a reverse travel direction R based on an operation position selected by a travel operation lever, clutch oil pressure of the forward clutch or reverse clutch, and a detected vehicle body speed. Braking force of a brake device is controlled such that the brake device is activated on the conditions that the travel direction position selected by the travel operation lever and the travel direction determined by a travel direction flag are opposite to each other, and the detected vehicle body speed is equal to or greater than a predetermined threshold value. | 01-15-2009 |
20090120386 | Control Apparatus and Control Method for Hydraulically Driven Cooling Fan - An invention relating to a control apparatus and a control method for a hydraulically driven cooling fan for reducing the peak pressure produced upon reversing the switch position of a switching valve, without stopping an engine, and without greatly modifying existing hydraulic circuitry or increasing the apparatus cost. In the invention, in the case that a reversing switch has been operated so as to output a reversal processing commencement instruction signal, control is carried out such that, under the condition that the rotational speed of the engine has decreased to not more than a stipulated rotational speed, capacity adjusting means is controlled, so as to reduce the capacity of a hydraulic pump, and thus reduce the fan rotational speed, and then the switch position of the switching valve is reversed. | 05-14-2009 |
20100071359 | HYDRAULIC DEVICE AND WORK MACHINE - A hydraulic device has a first pump, a second pump, an operating state detector configured and arranged to detect an operating state, a connection switching unit configured and arranged to selectively connect the second pump to either a first hydraulic oil line or a second hydraulic oil line, and a switching controller configured to control, based on the operating state detected by the operating state detector, a switching operation of the connection switching unit The switching controller is further configured to inhibit the switching operation of the connection of the second pump when the detected operating state is such that at least one of clutches of a multi-stage transmission and a steering device is in a state transition or at least one brake of the steering device is being operated. | 03-25-2010 |
20100107996 | WORK VEHICLE AND CONTROL METHOD FOR WORK VEHICLE - A work vehicle is provided with an engine, a traveling device driven by driving force from the engine to cause the work vehicle to travel, a first hydraulic pump driven by the driving force from the engine to discharge hydraulic oil, and a cooling device having a cooling fan driven by the hydraulic oil supplied by the first hydraulic pump to cool the engine, and a control unit. The control unit performs a normal cooling control in which an upper limit fan speed is determined based on an engine speed, and a cooling suppression control in which the upper limit fan speed determined based on the engine speed is suppressed to be less than the upper limit fan speed during the normal cooling control when a predetermined operation required to increase the engine speed is performed. | 05-06-2010 |
20100186925 | RADIATOR - A radiator includes a heat exchanger, an upper auxiliary tank, a lower auxiliary tank, an upper main tank and a lower main tank. The upper auxiliary tank is mounted on an upper surface of the heat exchanger. The lower auxiliary tank is mounted on a lower surface of the heat exchanger. The upper main tank is arranged at the substantially same height as the upper auxiliary tank and at an offset position relative to the upper auxiliary tank in the plan view. The upper main tank is connected to the upper auxiliary tank via a coolant water conduit pipe, and has a coolant water inlet on a lower surface thereof. The lower main tank is arranged under the upper main tank at an offset position relative to the upper main tank in the plan view, and is connected to the lower auxiliary tank. | 07-29-2010 |
20100198472 | WORK VEHICLE AND METHOD FOR CONTROLLING WORK VEHICLE - The work vehicle includes a braking device, a lubricant feeding section, and a controlling section. The controlling section configured to execute a first control in which an amount of the lubricant fed to the braking device is controlled based on a temperature of a rotating member of the braking device. The controlling section sets the amount of the lubricant to a predetermined first feed amount when the braking device is in a braking state, calculates the temperature of the rotating member, and makes a decision in the first control, based on the calculated temperature of the rotating member, to change the amount of the lubricant from the first feed amount to a second feed amount, which is smaller than the first feed amount, when the braking device is switched from the braking state to a non-braking state. | 08-05-2010 |
20100212450 | RIPPER OPERATING DEVICE - A ripper operating device is configured to perform operations of a ripper of a work vehicle. The ripper operating device includes a support portion, an operating lever, and an operating switch part. The operating lever is supported by the support portion to be movable with respect to the support portion in a first direction to perform a first operation and non-movable in a second direction. The first direction intersects a front-and-rear direction at an intersection point corresponding to a neutral position of the operating lever to form an acute angle with the front-and-rear direction on a rearward-outward side of the intersection point. The second direction is substantially perpendicular to the first direction and substantially matches with a direction in which a forearm of an operator extends when operating the ripper. The operating switch part is arranged on the operating lever to perform a second operation other than the first operation. | 08-26-2010 |
20110040458 | WORKING VEHICLE ENGINE OUTPUT CONTROL SYSTEM AND METHOD - An engine output control system is for a work vehicle composed of an engine, a travel device and a power transmission unit, the power transmission unit including a torque converter and transmitting an output of the engine to the travel device via the torque converter. The engine output control system includes a speed ratio computation portion and an engine output reduction control portion. The speed ratio computation portion is configured and arranged to compute a speed ratio of the torque converter. The engine output reduction control portion is configured and arranged to reduce an output torque of the engine without changing a target speed of the engine when the computed speed ratio is equal to or less than a speed ratio threshold set in advance. The speed ratio threshold is a speed ratio at which a torque ratio of the torque converter is greater than a torque ratio corresponding to a maximum efficiency. | 02-17-2011 |
20110196585 | CONTROL DEVICE FOR HYDRAULIC TRANSMISSION VEHICLE - A control device controls a hydrostatic transmission vehicle having a hydrostatic transmission including a variable displacement pump and a variable displacement hydraulic motor. The control device is configured to set a set vehicle speed based on a forward/rearward travel command and a gear stage command instructed by an operator, to set a torque limit usable for the hydrostatic transmission based on an engine speed, to set a vehicle speed limit based on a pressure in the hydraulic circuit and the torque limit, to select a lower one of the set vehicle speed and the vehicle speed limit, and to control respective displacements of the variable displacement pump and the variable displacement hydraulic motor based on the selected vehicle speed. | 08-11-2011 |
20110202243 | CONTROL DEVICE FOR HYDRAULIC TRANSMISSION VEHICLE - A control device controls a hydrostatic transmission vehicle having a hydrostatic transmission with a variable displacement pump and a variable displacement hydraulic motor. The control device is configured to set a set vehicle speed based on a forward/rearward travel command and a gear stage command instructed by an operator, to set an upper limit of the engine speed with respect to the set vehicle speed for limiting the upper limit of the engine speed to a predetermined partial engine speed set to be lower than a high idle engine speed when the set vehicle speed is in a preliminarily set low and intermediate speed range, and to control respective displacements of the variable displacement pump and the variable displacement hydraulic motor based on the set vehicle speed for allowing a vehicle speed to reach the set vehicle speed even when the engine is rotated at the partial engine speed. | 08-18-2011 |