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 hydraulic control system for an automatic transmission includes a regulator valve in a hydraulic circuit for supplying pressure to a servo of a frictional engagement element. The regulator valve has an input port, an output port and a drain port. A valve member of the regulator valve includes a pressure receiving area fed with a feedback pressure from the portion of the hydraulic circuit between the regulator valve and the servo, and another pressure receiving area selectively fed with pressure from a signal pressure source. A further pressure receiving area, having a surface area different from the another pressure receiving area, is constantly fed pressure from the signal pressure source.
摘要:
A shift control system for an automatic transmission including frictional engagement elements to be applied by actuating a piston by an oil pressure. The shift control system comprises: a pressure regulating valve for regulating the oil pressure to be fed to the frictional engagement elements and for controlling the regulated pressure level; a shift detector for detecting a shift to be executed by feeding the oil pressure to the frictional engagement elements; a low-pressure standby unit for setting the regulated pressure level of the pressure regulator valve to such a value during a predetermined time period after the shift has been detected that the oil pressure to be fed to the frictional engagement elements moves only the piston; and a booster for controlling the regulated pressure level so that the oil pressure to be fed to the frictional engagement elements may gradually increase after lapse of the predetermined time period.
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 oil pressure control system for an automatic transmission for executing a downshift by disengaging a first frictional engagement element and engaging a second frictional engagement element. At a latter stage of a shift, the first frictional engagement element has its torque capacity increased by raising its oil pressure temporarily. After this, if a synchronization substantially reaching the revolution number at a gear stage after the downshift is detected, the first frictional engagement element has its torque capacity gradually dropped by dropping the oil pressure thereof gradually, and the second frictional engagement element has its oil pressure abruptly raised.
摘要:
A five-speed automatic transmission includes a main transmission and an over-drive transmission of a front disposition type. The main transmission includes three sets of planetary gears, a clutch for engaging and disengaging speed-change elements of the planetary gear sets, and a brake for fixing and releasing the speed change elements, and provides for four forward speed ranges and one reverse speed range. In the over-drive transmission of a front disposition type, a speed change element of an over-drive planetary gear set connected to an input element of the main transmission is adapted to be engaged, disengaged and fixed for achieving either a directly coupled stage or an over-drive stage. The over-drive transmission releases the direct coupling for reverse driving operation. One of the clutches of the main transmission for achieving the directly coupled stage and one of the brakes for achieving the low speed stage are engageable in the reverse driving operation.
摘要:
An idle speed control method in which a feedback control for controlling the number of idle revolutions to a predetermined value, a learning control for determining a learning value needed to maintain the number of idle revolutions at the predetermined value, and an opening of the idle speed control valve are carried out. The feedback control is carried out when a predetermined feedback condition is satisfied, the learning control is carried out when a predetermined learning condition is satisfied, and the opening of the idle speed control valve is carried out when the feedback condition is not satisfied. Namely, if the present degree of opening of the idle speed control valve is larger than the learning value, the present degree of opening is maintained, and if the present degree of opening of the idle speed control valve is smaller than the learning value, the degree of opening is increased to the learning value. Also disclosed is a device for carrying out above method.
摘要:
In a hybrid vehicle, in order to stop an engine while a clutch is kept engaged and to transmit power from a motor to a drive shaft by changing a change speed state of a transmission when the power from a second motor is being transmitted to the drive shaft by the transmission, for example, a rotation speed of the first motor is adjusted so that the first motor can be connected to the drive shaft with the clutch disengaged while torque commands for both motors are set so that the power based on torque demand is outputted to the drive shaft, the power is transferred from the second motor to the first motor while both motors are connected to the drive shaft by the transmission, and the connection between the second motor and the drive shaft by the transmission is disconnected.
摘要:
The hybrid vehicle transfers power between the two motors, releases a coupling between one of the motors and the drive shaft, adjusts the rotation speed of one of the motors which is released from the coupling to the drive shaft by the transmission so as to enable drive source element connection, and connects the clutch as well as cranks the engine by either one or the other motor when the engine is started while the clutch is released, the engine is stopped, both the motors are coupled to the drive shaft as well as at least one of the motors is caused to output power.
摘要:
In a 2-motor drive mode with connection of both motors with a driveshaft by means of a transmission, a hybrid vehicle sets torque commands of the motors based on a torque demand set at step S110, in order to minimize the sum of a loss of the motors and to ensure output of a power equivalent to a preset torque demand to the driveshaft.