摘要:
A single sequence valve is connected to a 3-4 shift valve thereby defining a drain circuit. The sequence valve is responsive to hydraulic pressures which act on a fourth speed apply chamber of a band brake and a high clutch, respectively. The sequence valve normally defines the drain circuit, but delivers hydraulic fluid to the 3-4 shift valve, then to the fourth speed apply chamber of the band brake after a command for a 4-2 downshift has taken place until the hydraulic pressure in the high clutch drops to a predetermined value.
摘要:
An oil pump of an automatic transmission, which comprises a casing having an oil pump gear chamber formed therein, the casing having first and second bores exposed to the oil pump gear chamber, the first and second bores being coaxially spaced from each other with an interposal of the oil pump gear chamber therebetween; gears operatively disposed in the oil pump gear chamber of the casing; a first splined portion formed on a leading end portion of a stator shaft of a torque converter; and a second splined portion formed on an inner surface of the second bore, wherein the stator shaft is thrusted through the first and second bores in this order into a fixed position wherein the first and second splined portions are operatively engaged.
摘要:
An accumulator designed to alleviate a so-called N-D select shock is connected in a hydraulic control system for an automatic transmission such that it can also alleviate a 3-4 shift shock. The accumulator includes a piston and a spring biasing the piston. The spring force of the spring is appropriately set such that the piston starts moving against the spring in response to small pressure build-up of a drive range select pressure.
摘要:
An accumulator designed to alleviate a so-called N-D select shock is connected in a hydraulic control system for an automatic transmission such that it can also alleviate a 3-4 shift shock. The hydraulic control system includes a solenoid that controls a first hydraulic fluid pressure which is variable in a first pattern, a pressure modifier valve that changes the first pattern of variation of the first hydraulic fluid pressure to a second pattern and generates a second hydraulic fluid pressure variable in a second pattern, and a pressure regulator that is responsive to the second hydraulic fluid pressure to generate a third hydraulic fluid pressure that varies in response to the second hydraulic fluid pressure.
摘要:
An accumulator designed to alleviate a so-called N-D select shock is connected in a hydraulic control system for an automatic transmission such that it can also alleviate a 3-4 shift shock. The accumulator includes a piston and a spring biasing the piston. The spring force of the spring is appropriately set such that the piston starts moving against the spring in response to small pressure build-up of a drive range select pressure.
摘要:
Disclosed herein is a hydraulic control system for an automatic transmission wherein a first friction unit (C3) is engaged and a second friction unit (C2) is disengaged in downshifting from the 4th speed ratio to the 2nd speed ratio. An orifice device (660) is disposed in a fluid supply passage to a second port (124h) of a 3-4 shift valve (24) which is allowed to communicate with a first port (124g) communicating with the first friction unit (C3) when the 3-4 shift valve assumes a downshift position thereof. A timing valve (23) is arranged to provide a first bypass passage bypassing the orifice device when a fluid pressure in the second friction unit (C2) is lower than a predetermined value. A second bypass passage is provided to bypass the orifice device when the 2-3 shift valve (22) assumes an upshift position thereof.
摘要:
A shift valve for an automatic transmission wherein governor pressure acts on a spool in such a direction as to compress a first spring, and throttle representative pressure acts on a plug in such a direction as to compress the first spring. The shift control valve further comprises a second spring arranged to act on the spool in the same direction as the direction in which the governor pressure acts on the spool.
摘要:
A shift valve comprises a spool having a downshift position for establishing a lower speed ratio and an upshift position for establishing a higher speed ratio, a plug, and a spring between the spool and plug. The spool has a pressure acting area which governor pressure acts on, while the plug has a pressure acting area which throttle pressure acts on. At low throttle pressures, the spool moves from the downshift position to the upshift position when a predetermined vehicle speed is attained. At higher throttle pressures, the spool moves between the downshift and upshift position depending upon the governor pressure and throttle pressure. The shift valve has a port formed therein which admits a downshift position hold signal fluid pressure (i.e., line pressure) between the spool and plug so as to hold the spool to the downshift position thereof.
摘要:
A single accumulator is operatively connected to a fluid operated clutch so as to retard a rise in fluid pressure supplied to the fluid operated clutch which is to be engaged during a downshift from the highest speed ratio to any one of the lower speed ratios and when the transmission shifts from a neutral to a forward drive.
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.