Abstract: A work vehicle includes a hydraulic main speed change clutch and a Hi-Lo clutch provided to a power transmission device for transmitting power to drive wheels, and a speed change control device configured to control vehicle speed in multi-stage manner by a combination of the main speed change clutch and the hydraulic Hi-Lo clutch. In shift-up operation for changing the speed from a low speed stage range to a high speed stage range in which a high speed clutch is used, before completion of speed change, the high speed clutch pressure is kept at a first pressure (Pa) higher than the low speed clutch pressure while the pressure of the main speed change clutch, which is a speed change source, is kept, so that the power is transmitted by a combination of the high speed clutch and the main speed change clutch, which is a speed change source.

Abstract: A supercharger system is disclosed herein having a front end, a rear end, an inlet and an outlet, the system contained within a housing, wherein the supercharger system includes a rotor assembly, and a plurality of intake runners that comprise an interlaced cross-runner pattern, wherein the supercharger system comprises a front drive, front inlet configuration and an inverted orientation.

Abstract: A hydraulic control system for a transmission is provided. The hydraulic control system includes a source of pressurized hydraulic fluid that communicates with an electronic transmission range selection (ETRS) subsystem. In one example, the ETRS subsystem includes an ETRS control valve, a park servo that controls a park mechanism, a plurality of solenoids, and a park inhibit solenoid assembly. In another example, the ETRS subsystem includes an ETRS control valve, an ETRS enable valve, a park servo that controls a park mechanism, a plurality of solenoids, and a park inhibit solenoid assembly.

Abstract: A hydraulic control device includes an accumulator configured to accumulate oil supplied by a mechanical pump and supply the accumulated oil to a C1 control system (clutch) by discharging the accumulated oil; a first oil passage connected to the hydraulic route (clutch oil passage) on an upstream side of a SLC linear solenoid; a second oil passage connected to the hydraulic route on a downstream side of the manual valve; and connection control unit (a switching valve and a pressure accumulation control valve) configured to control the connection between the accumulator and the hydraulic route so that the accumulator is in communication with one of the first oil passage and the second oil passage.

Abstract: A hydraulic pressure control device includes an accumulator configured to accumulate oil supplied by a mechanical pump and discharge the accumulated oil to a control system; a first oil path connected to a hydraulic path (clutch oil path) at an upstream side than an SLC linear solenoid; a second oil path connected to the hydraulic path (clutch oil path) at a downstream side of a manual valve; a connection control unit (switching valve, accumulation control valve) configured to control the connection between the accumulator and the hydraulic path to communicate the accumulator to either one of the first oil path and the second oil path; and a back pressure control oil path configured to supply the oil supplied by the mechanical pump to the back pressure side of the accumulator.

Abstract: To provide a vehicle speed limiting system that is capable of executing a maximum speed limiting control without influencing a driving feeling of a vehicle. A vehicle speed limiting system includes: a three-dimensional map 46a and a throttle valve driving unit 47. A first maximum speed limiter opening degree is calculated by adding a first predetermined opening degree, a second predetermined opening degree, and a current throttle valve opening degree, the first predetermined opening degree being calculated by multiplying a speed difference of the vehicle by a preset P-term coefficient, the second predetermined opening degree being calculated by multiplying an acceleration of the vehicle by a preset D-term coefficient. Once the calculated first maximum speed limiter opening degree falls below the target throttle valve opening degree ?B, the throttle valve motor 30 is driven on a basis of the first maximum speed limiter opening degree.

Abstract: A shift control system for an automatic transmission. The shift control system includes an oil temperature sensor, a hydraulic controller to operate a hydraulic clutch, and a control unit in operative communication with the oil temperature sensor and the hydraulic controller. When a gear shift is requested just after an engine restart, the control unit controls the hydraulic clutch with an adjusted shift control process, in contrast to a normal condition of the engine. This adjustment is determined based on a first oil temperature at a time point when the engine is last stopped and on a temperature difference between the first oil temperature and a second oil temperature at a time point when the engine is last restarted after the last engine stop.

Abstract: An apparatus for controlling a vehicle automatic transmission having a hydraulically operated frictional coupling device operable to effect a shifting action of the automatic transmission, and an accumulator connected to the frictional coupling device, the apparatus including an accumulator-back-pressure learning compensation device operable to effect learning compensation of a back pressure of the accumulator such that an actual value of a rate of change of a rotating speed of a selected rotary element of the automatic transmission, which rotating speed changes as a result of the shifting action, approaches a predetermined target value, and an accumulator-back-pressure control device operable to control the back pressure, on the basis of an output of the accumulator-back-pressure leaning compensation device, whereby a shifting shock of the transmission can be reduced.

Abstract: A downshift control device for an automatic transmission is provided in which the transmission is shifted down by releasing an oil pressure from a first engaging element that has been engaged while applying an oil pressure to a second engaging element that has been released. This downshift control device determines whether a downshift command is generated to shift down the transmission while an accelerator pedal is being depressed, and detects a gear ratio that changes during the pedal-depressed downshift control. First control actuator controls the back pressure of a first accumulator provided in an oil path leading to the first engaging element, and second control actuator controls back pressure of a second accumulator provided in an oil path leading to the second engaging element.

Abstract: An upshift is effected by releasing an engaged first friction element and engaging a released second friction element. The first fiction element operates on a fluid pressure applied thereto through a first passage and the second friction element operates on a fluid pressure applied thereto through a second passage. An accumulator is provided in the first fluid passage. The accumulator has a back pressure port through which a back pressure is applied thereto by the function of a control valve having a first port connected to the back pressure port, a second port connected to a source of back pressure and a third port connected to a drain. The control valve operates, between a first position connecting the first port to second port and a second position connecting the first port to the third port, on first and second working signal pressures applied thereto.

Abstract: An upshift control device for an automatic transmission is provided in which the transmission is shifted up by releasing an oil pressure from a first engaging element that has been engaged while applying an oil pressure to a second engaging element that has been released.

Abstract: An up-shift control apparatus includes an engine racing detecting means for detecting engine racing during an up-shift and an engine racing preventing means. The up-shift control apparatus is installed to an automatic transmission which executes the up-shift by disengaging a first friction element and by engaging a second friction element. The engine racing preventing means outputs a command signal to a valve actuator to temporally increase an engagement force of the first friction element when the engine racing is detected during the up-shift.

Abstract: An automatic transmission has a friction element which induces a certain speed gear of the transmission when hydraulically operated. A fluid control circuit of the transmission comprises an accumulator valve unit which receives a line pressure for regulating a pressure of an operation fluid applied to the friction element in accordance with an engine load; and a shift valve which feeds the line pressure to the accumulator valve unit when assuming a first position and drains the operation fluid when assuming a second position. A flow restriction device is employed in the fluid control circuit for restricting the draining flow of the operation fluid.

Abstract: A method for shifting a powershift transmission of a vehicle in accordance with the load being experienced by the engine as estimated from certain engine operating parameters. A turbocharger associated with an engine operating at a given engine speed generates a turbo boost pressure. The turbo boost pressure is monitored by a sensor and a turbo boost signal is generated therefrom. Similarly, the engine speed is monitored by a sensor and an engine speed signal is generated therefrom. The turbo boost and engine speed signals are used to estimate the engine load based on empirical data stored in the transmission controller's memory, and a percentage load is computed therefrom. The percentage load is then used to generate an appropriate duty cycle and time value for a pulse-width-modulated shift signal which controls the modulation of an on-coming directional clutch into engagement at a desired rate of engagement dependent upon the load being experienced by the vehicle.