摘要:
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.
摘要:
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.
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:
A control system for use in an automatic transmission which includes a gear shift mechanism having first and second frictional engagement elements for establishing: a first gear stage with the first frictional engagement element being applied and the second frictional engagement element being released; and a second gear stage with the first frictional engagement element being released and the second frictional engagement element being applied. The control system, in turn, includes: a first oil passage for feeding an oil pressure to the first frictional engagement element; a second oil passage for feeding an oil pressure to the second frictional engagement element; and a first valve arranged in the first oil passage for regulating the oil pressure of the first oil passage. At the time of a shift from the first gear stage to the second gear stage, the oil pressure of the first oil passage is regulated by the first valve responsive to the oil pressure of the second oil passage. The control system further includes a second valve arranged in the first oil passage for selectively feeding or shutting off the oil pressure of the first oil passage to and from the first frictional engagement element.
摘要:
A control system for an automatic transmission, comprising a gear transmission unit for establishing a predetermined gear stage by applying a plurality of frictional engagement elements selectively. The gear transmission unit includes a main transmission portion capable of establishing at least a reverse gear stage, and an auxiliary transmission portion capable of switching a high gear stage and a low gear stage. The auxiliary transmission portion is set to the high stage at the shifting time to the reverse stage. The reverse stage is established by controlling the application of predetermined frictional engagement elements of the main transmission portion when a reverse stage shifting command is generated. A torque-down of an engine is executed at the time of controlling the engagement of the frictional engagement elements for the reverse stage. The auxiliary transmission portion is set to the high stage by controlling the applications of predetermined frictional engagement elements of the auxiliary transmission portion when the reverse stage in the main transmission portion is detected. A signal to end the engine torque-down is sent when a shift of the auxiliary transmission portion to the high stage is detected.
摘要:
An automatic transmission control system is equipped with a pressure modulating valve for regulating the engaging pressure to be supplied to frictional engagement elements for setting respective gear stages of the automatic transmission, a signal pressure output valve for providing signal pressure, and a switching valve. The control system further includes a switching valve for switching destinations of signal pressure for setting pressure regulation level between pressure modulating valve and other control valve; an abnormality-detection element for detecting, in gear shift to a gear stage set by the frictional engagement elements engaged on delivery of regulated oil pressure, abnormal regulation of engaging pressure to be delivered to the frictional engagement elements and abnormal operation due to delivery of the signal pressure to the control valve; and gear-shift-inhibition element for inhibiting shift to the gear stage in case that the abnormality-detection element detects at least one of abnormal pressure regulation and the abnormal operation.
摘要:
A shift control system is provided for an automatic transmission having, connected in series, a secondary shifting unit, capable of being shifted between a high speed stage and a low speed stage, and a primary shifting unit which provides plural speed stages including a reverse speed stage. The secondary shifting unit can be set to the high speed stage upon a shift into reverse. The shift control system is equipped with a reverse range detector for detecting a shift from neutral to reverse range, a vehicle stop detector for detecting that vehicle is stopped, and a high speed stage command device for setting the secondary shifting unit at the high speed stage when, subsequent to a shift of the primary shifting unit into reverse, the vehicle is determined by a signal from the vehicle stop detector to have substantially stopped.
摘要:
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.
摘要:
An automatic transmission includes a first rotating element provided by coupling a sun gear of a second planetary gear set and a carrier of a third planetary gear set to each other, a second rotating element provided by coupling a carrier of the second planetary gear set and a ring gear of the third planetary gear set to each other, a third rotating element provided by a ring gear of the second planetary gear set, and a fourth rotating element provided by a sun gear of the third planetary gear set. The first rotating element and the second rotating element are coupled to a case by first and second brakes, the fourth and first rotating elements are coupled to a ring gear of a first planetary gear set via first and second clutches, the second and first rotating elements are coupled to an input shaft via third and fourth clutches, and the third rotating element is integrally coupled to an output gear, so that the automatic transmission can provide eight forward gear stages by changing a combination of two of the clutches and brakes which are engaged to each other.
摘要:
A vehicle planetary gear type multiple-step transmission wherein each of five rotary elements is constituted by sun gears, carriers and ring gears of three planetary gear sets, and speeds of the rotary elements are represented by respective straight lines in a collinear chart, and the first, second and third rotary elements are made stationary by respective first, second and third brakes, and the fifth, third and first rotary elements are connected to an input shaft by respective first, second and third clutches, while the third rotary element is brought to a disconnected state by fourth clutch, and the fourth rotary element is connected to an output rotary member.