摘要:
A hydraulic control system for an automatic transmission comprises a first shift valve and a second shift valve which are coupled with a first port and a second port of a manual valve, respectively. The first shift valve receives a forward drive range pressure from the first outlet port of the manual valve when the manual valve is set in D or II or I range. The second shift valve receives a forward drive and reverse drive range pressure from the second outlet port of the manual valve when the manual valve is set in D or R or N range. The second shift valve is also coupled with a third outlet port of the manual valve to receive a manual range pressure when the manual valve is set in II or I range. The second shift valve is urged by the manual range pressure to shift to a downshift state wherein an outlet port thereof is allowed to communicate only with a drain port thereof.
摘要:
A shift valve arrangement for incorporation into a hydraulic control system of an automatic power transmission, comprising a shift valve including separate switching and control valve elements arranged and movable in series with each other, the control valve element havind different pressure acting areas to be acted upon by a fluid pressure when the control valve element is in upshift and downshift positions, respectively, under kickdown condition and a pressure acting area to provide an upshift pattern of the transmission for part-throttle conditions of the engine, and a downshift valve having pressure acting areas to provide a downshift pattern for the part-throttle conditions of the engine.
摘要:
A transmission throttle valve for use in a hydraulic control system of an automotive automatic power transmission, comprising a valve plunger movable with the accelerator pedal of an automotive vehicle, a valve spool arranged and movable in line with the valve plunger, a spring urging the valve spool and the valve plunger in opposite directions to each other for enabling the valve spool to produce a throttle pressure variable with the distance of movement of the valve plunger in the presence of a line pressure directed into the transmission throttle valve, and a plunger guide member arranged so that the throttle pressure developed in the valve is augmented to the level of the line pressure in the event a failure takes place in a mechanical linkage providing engagement between the valve plunger and the accelerator pedal of the vehicle.
摘要:
A hydraulic control system for a torque converter including a lockup clutch is disclosed in which a first or feed passageway communicates with a source of pressurized fluid and with a torque converter chamber, a second or discharge passageway communicates with the torque converter chamber and a third passageway communicates with a lock-up control or clutch chamber of the lockup clutch. A lock-up control valve communicates with the same source of pressurized fluid and with the third passageway. The first passageway is provided with a flow restrictor. With the provision of the flow restrictor, the disengagement of the lockup clutch will be assured upon pressurization of the third passageway.
摘要:
A transmission throttle valve for use in a hydraulic control system of an automotive automatic power transmission, comprising a valve plunger movable with the accelerator pedal of an automotive vehicle and, a valve spool engaging the valve plunger through a spring urging the valve plunger and the valve spool to axially move in opposite directions relative to each other for producing a fluid pressure variable with the displacement of the accelerator pedal, wherein the valve spool is formed with an axial bore open at both ends and has the valve plunger slidably passed through the bore while the valve plunger is formed with a laterally enlarged axial portion forming a variable-volume space in which the fluid pressure developed by the transmission throttle valve is to be admitted to urge the valve plunger to axially move against the force of the spring so as to save the driver's effort for depressing the accelerator pedal.
摘要:
A control system for a continuously variable automatic transmission for an automotive vehicle, includes a throttle opening sensor that detects a throttle opening, and a controller that executes a change-speed control in a normal mode in which a desired transmission input speed is determined based on operating conditions of the vehicle and a desired transmission ratio is determined based on the desired transmission input speed when the throttle opening is less than a first value, and that executes the change-speed control in a linear mode in which the desired transmission ratio is fixed to a second value when the throttle opening is greater than or equal to the first value. The second value is set based on the desired transmission ratio used in the normal mode prior to switching to the linear mode.
摘要:
A shift control system for an automatic transmission is disclosed, which comprises, in the first embodiment for example, an orifice bypass valve including a spool, a spring and a pilot port. The spool is movable between an interrupting position where a first hydraulic passage is interrupted from a third hydraulic passage, and a connecting position where a first passage is connected with a third passage, and it is pressed to the interrupting position by the spring. The pilot port induces a force by which the spool is pressed in the direction opposite to a force of the spring when the hydraulic fluid is supplied, and it is connected with a fourth hydraulic passage for receiving the hydraulic fluid for operating an overrunning clutch.
摘要:
An output shaft is supported by means of a ball bearing at one end, a radial needle bearing and a thrust bearing. The ball bearing is arranged for supporting the output shaft against most part of radial load. On the other hand, the trust bearing is arranged for supporting the output shaft against the thrusting force which is exerted on the output shaft while the engine driving torque is transferred therethrough. Such construction reduces radial and thrusting stress to be exerted on the needle bearing. Therefore, the radial needle bearing to be used in the shown construction is required substantially small load capacity and thus can be satisfactorily small for allowing the transaxle unit to be designed compact.
摘要:
An accumulator which is pressurized during the engagement of the band brake, is arranged with a one-way valve so that the discharge therefrom, which accompanies the downshifting of an associated shift valve, temporarily maintains a pressure which is supplied to an overrunning clutch control valve and which holds the spool valve elements therein in a position wherein the overrunning clutch is drained.
摘要:
A low restrictor is provided in a hydraulic line having one end connected to a fourth speed servo apply chamber of a friction device, in the form of a band brake, and an opposite end connected to a 3-4 shift valve. An accumulator is connected to the hydraulic line at a first section between the flow restrictor and the friction device. A lock-up control valve is connected to the hydraulic line at a second section between the flow restrictor and the 3-4 shift valve. The lock-up control valve includes a spool movable to a first position where a lock-up clutch is released from a second position where the lock-up clutch is engaged in response to a drop in hydraulic pressure within the second section of the hydraulic line upon shifting from the fourth speed ratio to the third speed ratio. Since the transmission of this drop to the first section of the hydraulic line is delayed by the flow restrictor and the accumulator, the release of the friction device is delayed.