摘要:
A control mechanism for a hydrostatic-mechanical power transmission system having a mechanical transmission unit driven through an input shaft connectable to a power source, and a hydrostatic transmission unit that is connectable to the input shaft and includes a pump and a motor each having a displacement setting swash plate. The control mechanism further includes a differential unit for connecting an output shaft to the mechanical transmission unit and the hydrostatic transmission unit to drive. At least either of the displacement setting swash plates is variable in angle. The control mechanism also includes a throttle position detector for detecting the position of a throttle in relation to the power source; a target motor speed ratio setting device for setting, based on the position of the throttle detected by the throttle position detector, a target motor speed ratio that is a target value for the ratio of the revolution speed of the motor in the hydrostatic transmission unit to the revolution speed of the power source; and a swash plate angle controller for controlling at least either of the angles of the displacement setting swash plates by feed-forward control in which the target motor speed ratio set by the target motor speed ratio setting device is used in such a way that the ratio of a displacement volume of the pump to a displacement volume of the motor is made to follow the target motor speed ratio.
摘要:
A dozing control unit for a bulldozer, comprising an actual tractive force detector for detecting the actual tractive force of a vehicle body; a driving mode selector button capable of switching a manual operation mode to an automatic driving mode in dozing operation; and a blade controller for controlling a blade to be lifted or lowered such that if there is a difference between the actual tractive force detected by the actual tractive force detector and a target tractive force set for the automatic driving mode when the manual operation mode is switched to the automatic driving mode by the driving mode selector button, the actual tractive force gradually comes closer to the target tractive force.
摘要:
A hydraulic control apparatus for an automatic transmission of a motor vehicle, the transmission including a lock-up clutch, the apparatus including a lock-up clutch switching valve device which is operable for selectively placing the lock-up clutch in a fully released, a partially engaged, and a fully engaged state thereof; a hydraulic pressure producing device which produces a hydraulic pressure; an abnormality detecting device which detects an abnormality of at least one of the lock-up clutch and the lock-up clutch switching valve device; and a control device which, when the abnormality detecting device detects the abnormality, operates the hydraulic pressure producing device for one of (a) applying the hydraulic pressure, and (b) inhibiting the hydraulic pressure from being applied, to at least one of the lock-up clutch and the lock-up clutch switching valve device for forcibly placing the lock-up clutch in one of the fully released and fully engaged states thereof.
摘要:
In order to control the engine output timing always properly irrespective of the aging of an automatic transmission, the present invention provides a shift control system for a vehicular automatic transmission, which system comprises: release end detecting means for detecting the release end of a frictional engagement element for a higher gear stage, at a shifting time from higher to lower gear stages; synchronism detecting means for detecting the synchronism between an engine R.P.M. and a rotating element in the automatic transmission at the lower gear stage; and engine output control means for controlling the output of the engine. The aforementioned engine output control means starts the rise control of the engine output, when the release end of the frictional engagement element for the higher gear stage is detected by the release end detecting means, and ends the rise control of the aforementioned engine output when the synchronism between the engine R.P.M. and the rotating element in the automatic transmission at the lower gear stage is detected by the synchronism detecting means.
摘要:
An adaptive control system/method for an at least partially automated mechanical transmission system (10) is provided for determining if selected upshifts into a target gear ratio are feasible (208) or not feasible (210) under current vehicle operating conditions and for prohibiting the initiation of not feasible selected upshifts. If upshifts determined to be feasible are not completed by the system, the logic rules by which upshift feasibility is determined are modified to render such rules less aggressive.
摘要:
A speed change control method and apparatus for a vehicular automatic transmission having a first-speed clutch for establishing a first speed and a second-speed clutch for establishing a second speed, includes subjection of at least a duty ratio Dr of a second-speed solenoid valve for supplying oil pressure to the second-speed clutch to feedback control, so that the first-speed clutch is engaged while disengaging the second-speed clutch. This thereby increases a turbine rotational speed Nt toward the first-speed synchronous rotational speed. Further, an upper limit value Dmax of the duty ratio Dr is set, and the duty ratio Dr is subject to feedback control within a resultant duty ratio range. This thereby prevents the duty ratio Dr from being set at an excessive value caused by a delay in the rise of the oil pressure. As a result, even if a depression of an accelerator pedal is suddenly increased during a downshifting process, an interlock problem can be prevented, thereby ensuring smooth speed change.
摘要:
A speed change control method for a vehicular automatic transmission, in which the transmission stage position of the automatic transmission having a plurality of transmission stages is changed to an optimum transmission stage set by fuzzy inference on the basis of parameter values indicative of the operating conditions of a vehicle. If a failure of any of sensors for detecting the parameter values concerned in the fuzzy inference is detected, setting the optimum transmission stage by the fuzzy inference is inhibited, and the optimum transmission stage is set in a speed change control mode which is not dependent upon the broken sensor. Thus, even in case of failure of a sensor, the vehicle can be driven without hindrance and without discomfort to a driver or fellow passengers.
摘要:
An electrohydraulic control system for an automatic transmission includes planetary gearsets, clutch and brakes that control the condition of the gear components, hydraulically actuated solenoid control valves, electronic sensors connected to a microprocessor, a gear selector mechanism and an overdrive cancel switch. The extent to which a gear ratio change is completed, as represented by the ratio of the current operating gear ratio and the gear ratio associated with gear ratio at the completion of the gear shift, is used as a variable in algorithms executed by the microprocessor to schedule change in state of solenoid operated valve. The state determines the engaged and disengaged condition of friction elements that produce the gear shift.
摘要:
A lock-up clutch for a flow converter having pump and turbine blades which are hydraulically coupled, in which a ring piston is located between the converter cover and the turbine blades. The ring-piston and converter cover have mating conically shaped friction surfaces, thereby leaving a wedge-shaped space between the converter cover the turbine blades and the friction surface of the ring piston. An annular damper unit located in the wedge-shaped space has a plurality of damper elements which are coupled to the turbine vanes by fingers extending from the turbine vanes.
摘要:
A control system/method for an at least partially automated mechanical transmission system (10) is provided for determining if selected upshifts into a target gear ratio are feasible (208) or not feasible (210) under current vehicle operating conditions and for prohibiting the initiation of not feasible selected upshifts.