Abstract:
A parking control mechanism to prevent generation of noise and shock when a parking range is released after a vehicle has been parked so that a driver does not feel uncomfortable. A parking apparatus of an automatic transmission has a parking gear; a parking pole swingably disposed and provided with a claw arranged to selectively be engaged with a tooth space of the parking gear; an engagement inhibition device movably disposed and arranged to be moved to an inhibition position for inhibiting engagement between the claw and the tooth space and to an inhibition release position for releasing the inhibition of the engagement; and an engagement inhibition release device for moving the engagement inhibition device to the inhibition release position in synchronization with the rotation of the parking gear. After a residual torque existing between the parking gear and drive wheels has been released, the claw and the tooth space are engaged with each other.
Abstract:
A shift control system of an automatic transmission for setting a predetermined gear stage by applying first frictional engagement means and releasing second frictional engagement means, comprising: a pressure regulating mechanism for regulating an oil pressure to be fed to or drained from the first frictional engagement means; a failure detector for detecting a failure of an apparatus to participate in the regulation and control of the oil pressure which is to be fed to or drained from at least one of the first and second frictional engagement means: and a gear stage inhibitor for inhibiting the setting of the predetermined gear stage if the failure is detected by the failure detector.
Abstract:
An oil pressure controller of an automatic transmission which is capable of supplying engaging pressures to hydraulic servos of two frictional engaging elements which require different engaging pressures by a single pressure governing valve with a good pressure governing accuracy. The oil pressure controller comprises a hydraulic power source (10), hydraulic servos (70 and 80), signal pressure generating means (20), a pressure governing valve (30) for governing an oil pressure (P.sub.s) from the hydraulic power source (10) by a signal pressure (P.sub.ACC) and a control valve (40). The pressure governing valve (30)has a pressure receiving face A.sub.1 to which the signal pressure is applied, a pressure receiving face A.sub.2 to which the engaging pressure (P.sub.s) is fed back in the opposite direction and a pressure receiving face (A.sub.3) for selecting whether the feedback of the engaging pressure is present or not in order to change the control gain of the pressure governing valve (30)in response to the change of the control valve (40) for selecting the hydraulic servo (70 or 80) to which the oil pressure is supplied.
Abstract:
A control system for an automatic transmission including a main transmission unit for setting a reverse stage and a plurality of forward stages and an auxiliary transmission unit connected in series to the main transmission unit and capable to be changed between two higher and lower stages. The control system comprises: a solenoid valve for outputting a signal pressure when at least the reverse stage and a predetermined one of the forward stages are to be set; a change-over valve for changing the signal pressure selectively into a signal pressure for setting the auxiliary transmission unit to a high gear stage and a signal pressure for controlling an engine braking state; and an engine braking control valve for controlling an engine braking frictional element at the predetermined forward stage into a released state in response to the signal pressure coming from the change-over valve. The acting state of the solenoid valve when the reverse stage is to be set and the acting state of the solenoid valve when the predetermined forward stage for making the engine braking ineffective is to be set are identical to each other.
Abstract:
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.
Abstract:
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.
Abstract:
An automatic transmission of a vehicle including a speed change gear mechanism including rotary members such as gears and gear carriers and hydraulically operated friction engaging means and adapted to provide various speed stages according to selective engagement and disengagement of the friction engaging means is controlled by such steps as detecting rotation speed of at least one of the rotary members during a shifting between the speed stages, changing hydraulic pressure of at least one of the friction engaging means during a first phase of the speed stage shifting so as to make the rotation speed of the one rotary member follow a first change performance curve calculated according to a first feedback control program, and changing the hydraulic pressure of the one friction engaging means during a second phase of the speed stage shifting so as to make the rotation speed of the one rotary member follow a second change performance curve calculated according to a second feedback control program in continuity to the first change performance curve.
Abstract:
In an automatic transmission according to the present invention, a coast brake cutoff valve is arranged between a range-pressure-producing manual valve and shift valves and, when changed over, selectively feeds oil to hydraulic engine brake servomotors. An engine brake solenoid valve is on/off controlled by a shifting output signal from a CPU, whereby the coast brake cutoff valve is selectively changed over. A lockout valve is arranged between the coast brake cutoff valve and the manual valve and is connected to one of shifting solenoid valves. The automatic transmission can therefore be operated without trouble even when an electrical problem occurs in the shifting solenoid valves and/or the engine brake solenoid valve.
Abstract:
A shift control system for a vehicular automatic transmission including a gear train to be set to a plurality of gear stages in accordance with the engaged or released states of a plurality of friction devices. The shift control system comprises: a mode selector for interchanging an automatic shift mode to effect a shift according to a first gear stage train, which is composed of a plurality of gear stages selected from those capable of being set with the gear train, a manual shift mode to effect a shift according to a second gear stage train, which is composed of other plural gear stages selected from those capable of being set with the gear train; an automatic shift output device for outputting a shift signal in accordance with the running state of the vehicle to set any of the gear stages of the first gear stage train when the automatic shift mode is selected; a gear stage selector for outputting an upshift signal and a downshift signal in response to the manual operations of upshift and downshift, respectively, when the manual shift mode is selected; a manual shift output device responding to the upshift signal and downshift signal outputted from the gear stage selector, for outputting a shift signal to select a gear stage from the second gear shift train and to set the selected gear stage; and a hydraulic controller for feeding/releasing an oil pressure to the friction devices to set the gear stage which is commanded by the shift signals outputted from the automatic shift output device and the manual shift output device.
Abstract:
A power transmission unit in which an inspection and tuning of an electric motor can be carried out easily. In the power transmission unit, a rotor of the electric motor is arranged between a first shaft of an input side and a second shaft of an output side, and in which the first shaft, the second shaft, and the rotor are integrally connected at least in a rotational direction. The first shaft is connected with the rotor, and the first shaft is also connected with the second shaft.