JPH01169162A - Hydraulic release valve for hydraulically operated clutch - Google Patents

Abstract

PURPOSE:To release a pressure of oil in a front stage by a single valve by inserting a spool to be fitted in a housing, a having a clutch port communicating with a pressure oil chamber in a front stage clutch and a drain port communicating with a drain side, while arranging an urging means which urges this spool to an operative position. CONSTITUTION:When a hydraulic release valve 60 is used, in the time of upshift, an internal pressure (operating oil) in a pressure oil chamber in a rear stage clutch (upshift side clutch) acts on a port 124a in an upshift side formed in a housing 61 of this valve 60, and its spool 62 is moved to a release position. In this way, an oil pressure layer of a front stage clutch (engaging clutch before speed change) communicates with a drain port 125a, and this internal pressure is released. While in the time of downshift, the internal pressure in the pressure oil chamber in a rear stage clutch (downshift side clutch) acts on a downshift side port 122a, and moving the spool 62 of the valve 60 to the release position, similarly to the above, the pressure oil chamber of the front stage clutch communicates with the drain port 125a, releasing the internal pressure.

Description

DETAILED DESCRIPTION OF THE INVENTION (11) Purpose of the Invention (Field of Industrial Application) The present invention relates to a control valve for speed change control in an automatic transmission.

(Prior Art) An automatic transmission includes a plurality of gear trains arranged in parallel, and automatically selects one of the gear trains to set an appropriate gear ratio according to the driving condition. A hydraulically operated clutch is used to select the desired gear train, and a control valve controls supply and discharge of hydraulic oil to the hydraulically operated clutch to perform automatic gear shifting. Various types of automatic transmissions having such control valves have been proposed in the past, and one example is the one disclosed in Japanese Patent Publication No. 52-21131.

When a shift is performed in such an automatic transmission, the hydraulic pressure in the hydraulic chamber of the clutch that has been engaged (this is called the front clutch) is released to the drain side, and the gear to be shifted is released. Hydraulic oil at a predetermined line pressure is supplied to the hydraulic chamber of the row clutch (referred to as the rear clutch). In this case, the release of the hydraulic fluid in the hydraulic chamber of the front clutch to the drain side is synchronized with the supply of line pressure to the hydraulic chamber of the rear clutch, so the clutch hydraulic pressure is activated by the hydraulic pressure in the hydraulic chamber of the rear clutch. A release valve is used.

Here, if the preceding gear is an intermediate gear, the gear change modes include a downshift to a gear with a larger gear ratio, and an upshift to a gear with a smaller gear ratio. Therefore, two valves, a downshift valve and an upshift valve, have been used as the clutch oil pressure release valve.

(Problem to be solved by the invention) Using two valves in this way naturally increases costs and requires a large amount of space.Therefore, in the present invention, even in the case of upshifting, Note that the same clutch is used in the front stage to release hydraulic pressure in the case of a downshift, and one valve is used to release the hydraulic pressure in the front stage in both downshifts and upshifts. The purpose is to make it possible.

Configuration of the Invention (Means for Solving the Problem) As a means for achieving the above object, the hydraulic release valve of the present invention is configured as follows. That is, when a spool is inserted into a housing that has a clutch port that communicates with the hydraulic chamber of the front clutch and a drain port that communicates with the drain side, communication between the clutch port and the drain port is cut off. The spool is movable between an operating position and a release position communicating the clutch port and the drain port, and is further provided with biasing means for biasing the spool toward the operating position, while the housing includes: an up-seat side port that communicates with the hydraulic chamber of the rear-stage clutch during upshifting and causes the internal pressure of this clutch hydraulic chamber to act on the spool to move the spool to the release position side against the urging force of the urging means; A downshift side port is formed which communicates with the hydraulic chamber of the rear clutch during a shift and causes the internal pressure of this clutch hydraulic chamber to act on the spool to move the spool to the release position side against the urging force of the urging means. It is composed of

(Function) When the above-mentioned hydraulic pressure release valve is used, during upshift, the hydraulic chamber pressure (working oil pressure) of the rear clutch (upshift side clutch) acts on the upshift side port formed in the housing of this valve. The spool of the valve is moved to the release position, and the hydraulic chamber of the front-stage clutch (the clutch engaged before shifting) is communicated with the drain side to release this internal pressure. Also, during downshifting, the pressure in the hydraulic chamber of the rear clutch (downshift side clutch) acts on the downshift side port, moving the spool of this valve to the release position, and in the same way as above, the pressure in the hydraulic chamber of the rear clutch (downshift side clutch) The hydraulic chamber of the mating clutch is communicated with the drain side to release this internal pressure.

(Embodiments) Hereinafter, preferred embodiments of the present invention will be described based on the drawings.

FIG. 1 is a schematic diagram showing the configuration of an automatic transmission in which the valve of the present invention is used. In this transmission AT, engine output transmitted from an output shaft 1 of the engine via a torque converter 2 is , the speed is changed by a transmission yi10 having a plurality of gear trains, and the output is output to the output shaft 6. Specifically, the output of the torque converter 2 is output to the main shaft 3, and five sets of gear trains are arranged in parallel between the main shaft 3 and a counter shaft 4 arranged parallel to the main shaft 3. The output gear train 5 is further arranged between the counter shaft 4 and the output shaft 6.
It is output to the output shaft 6 via a and 5b.

The five sets of gear trains arranged between the main shaft 3 and the counter shaft 4 are single gear trains 11a, llb.
, two gear trains 12a, 12b, and three gear trains 13
a, 13b, four gear trains 14a, 14b, and reverse gear train 15a.

15b and 15c, and each gear train includes a hydraulically operated clutch ll for transmitting power through that gear train.
c, 12c, 13c, 14c, and 15d are arranged. In addition, one-way clutch li is used for single gear llb.
d is arranged.

Therefore, by selectively operating these hydraulically operated clutches, it is possible to select power transmission by any one of the five gear trains to perform a speed change.

A control valve C2 selectively controls the operation of this hydraulically operated clutch, and this control valve Cv will be explained with reference to FIG.

In this control valve C■, hydraulic oil from the oil sump 7 supplied from the pump 8 is guided to the regulator valve 30 via the line 101.
0 to adjust the pressure to a predetermined line positive. This line pressure is led to the manual valve 40 via the line 110, and the hydraulically operated clutches llc, 12c, 13c, 14 for each speed gear are operated by various valves in the control valve CV.
It is selectively supplied to clutches c and 15d depending on the driving conditions, and the operation of each clutch is controlled.

Here, first, various valves within the control valve CV will be explained. The check valve 35 is disposed downstream of the regulator valve 30 and prevents the oil pressure of the lubricating oil sent to the lubrication section of the transmission through the line 102 from exceeding a predetermined pressure. The modulator valve 48 reduces the line pressure sent through the line 103 to create a predetermined modulator pressure, and supplies the hydraulic fluid at this modulator pressure to the torque converter 2 through the line 104.
The line 1 is supplied to a lock-up clutch control circuit (not shown) for lock-up clutch control.
05 for the shift valve operation.

The manual valve 40 is operated in conjunction with a shift lever operated by the driver, and is set to P and R.

It is located at one of six positions, N, D, S, and 2, and the supply of line pressure from the line 110 is controlled according to each position.

1-2 shift valve 50.2-3 shift valve 52.3
-4 shift valve 54 is similar to manual valve 50,
S, 2, this position and the first and second solenoid valves 71.7
It is a valve that is operated by the action of modulator pressure supplied in accordance with the ON/OFF operation of 2, and controls the supply and discharge of line pressure to clutches 11c, 12c, 13c, and 14c from 1st to 4th speed, These valves 50.52
．． Shifting is performed by operating 54.

The clutch pressure control valve 45 controls the line pressure supplied to each clutch ILc to 14c to a desired oil pressure using a linear solenoid 46, and thereby performs oil pressure control during gear shifting to prevent gear shifting shock. , the clutch capacity is appropriately controlled by generating line pressure corresponding to the small opening degree of the slot.

@1 to 3rd orifice control valve 60.66.
68 releases the hydraulic pressure of the front clutch during gear shifting,
This is a valve that synchronizes the timing with the oil pressure rise of the rear clutch. 1st orifice control valve 6
0 is downshift from 3rd to 2nd and 3rd to 4th
The hydraulic pressure in the hydraulic chamber of the third speed clutch 13c is released when upshifting to high speed. The second orifice control valve 66 releases the hydraulic pressure in the hydraulic chamber of the second speed clutch 12c when upshifting from second speed to third speed or from second speed to fourth speed. The third orifice control valve 68 releases the hydraulic pressure in the hydraulic chamber of the 4th speed clutch 14c when downshifting from 4th speed to 3rd speed or from 4th speed to 2nd speed. Note that an electric switch 65.69 is provided at the left end of the first and third orifice control valves 60.68, and this is a switch that is turned on according to the movement of the spools of both valves. It is used as a signal to detect a shift and limit engine output to prevent shift shock during the shift.

Accumulators 90.95 are connected to the first speed clutch LLC and reverse clutch 15d, respectively, to smooth oil pressure fluctuations when these clutches LLC and 15d are actuated to prevent shift shock from occurring. ing. Also, 2nd to 4th speed clutch 12c
~14c has Clara 1 chip pressure switch 80, 82
．． 84 is connected, and this switch 80, 82.8
By detecting the movement of the spools 4 through the electric switches 81, 83 and 85, the start of operation of each of the clutches 120 to 14c is detected, and the timing at which the clutch pressure control valve 45 starts controlling the line pressure is determined.

In the control valve CV configured as described above, the manual valve 40 is operated by operating the shift lever, and the solenoid valves 71 and 72 are turned ON-OFF.
The operation causes each of the above valves to operate, and each clutch
Line pressure is selectively supplied to the gears c to 15d to effect automatic gear shifting, but since its operation is conventionally known, its explanation will be omitted.

The first orifice control valve 60 in the control valve C■ corresponds to the hydraulic pressure release valve according to the present invention, and this valve 60 will be explained in detail with reference to FIGS. 3 and 4.

This valve 60 includes a housing 61 and a housing 61.
A spool 62 is inserted into the spool 62 so as to be movable from side to side in the figure.
It has a spring 64 that contacts the left side surface of the spool 62 and urges it to the right, and an arm 65a that faces the left end projection 63 of the spool 62, and is pushed by the left end projection 63 when the spool 62 is moved to the left. ON due to movement of arm 65a
and an actuated electrical switch 65.

Furthermore, the housing 61 is connected to the
A clutch port 123a communicates with the speed clutch 13c, a drain port 125a communicates with the drain via line 125, and a drain port 125a communicates with the second speed clutch 12c via line 122.
A downshift side port communicating with the fourth speed clutch 14c via a line 124 and an upshift side port 124a communicating with the fourth speed clutch 14c are formed.

Let us first consider the state of the valve 60 having the above configuration at the third speed. At this time, the 2nd speed and 4th speed clutch 1
The pressures in the hydraulic chambers 2c and 14c are both zero, and the downshift side and upshift side ports 122a and 124a
The oil pressure inside is zero. Therefore, the spool 62 is moved to the right by the bias of the spring 64 as shown in FIG.
2c, but since this groove 62c is closed, communication between the clutch port 123a and the drain port 125a is cut off. That is, the spool 62 is in the operating position, and when a predetermined line pressure is supplied to the 3rd speed clutch 13c, this line pressure is maintained as it is, and the 3rd speed clutch 13C is engaged to shift the 3rd speed gear train 13a, 13b. The power transmission through is the turning part.

Next, consider the case where the gear is upshifted from 3rd gear to 4th gear. In this case, the shift valve is activated and the 4
Line pressure is supplied to the speed clutch 14c, and when the internal pressure of the fourth speed clutch 14c begins to rise, this internal pressure is supplied to the upshift side port 124a via the line 124. The hydraulic pressure supplied to this port 124a acts on the right end surface 62a of the spool 62, and moves the spool 62 to the left against the biasing force of the spring 64 as shown in FIG. That is, the spool 62 is moved to the release position, and as a result, the clutch port 123a and the drain port 125a communicate with each other, and the pressure in the hydraulic chamber of the 3rd speed clutch 13c increases with the pressure in the hydraulic chamber of the 4th speed clutch 14c. The water is drained at the same timing, the third speed clutch 13c is released, and the fourth speed clutch 14c is simultaneously engaged to perform an upshift.

Contrary to the above, consider the case of downshifting from the 3rd speed state. In this case, line pressure is supplied to the second speed clutch 12c, and when the internal pressure of the second speed clutch 12c begins to rise, this internal pressure is supplied to the downshift side port 122a via the line 122. This port 122
The hydraulic pressure supplied to a acts on the stepped portion 62b of the spool 62, and in this case as well, the spool 62 is moved to the left against the biasing force of the spring 64 as shown in FIG.
to the release position. As a result, the clutch port 123a and the drain port 125a communicate with each other, and the pressure in the hydraulic chamber of the 3rd speed clutch 13c is drained in synchronization with the increase in the pressure in the hydraulic chamber of the 2nd speed clutch 12c, and the engagement of the 3rd speed clutch 13c is interrupted. At the same time, the second speed clutch 12c is engaged and a downshift is performed.

Incidentally, during the upshift or downshift, when the spool 62 is moved to the release position (moved to the left) as shown in FIG. 4, the spool left end 63 pushes the arm 65a of the electric switch 65. Activate ON. This ON operation is detected as a shift start signal, and this signal is used to limit (retard) the engine output during shifting, thereby reducing shift shock.

As described in detail, according to the present invention, during an upshift, the pressure in the hydraulic chamber of the rear clutch acts on the upshift side port, moves the spool to the release position, and releases the hydraulic chamber of the front clutch. This internal pressure is released by communicating with the drain side. Also, when downshifting, the hydraulic chamber pressure of the rear clutch acts on the downshift side port, moving the spool to the release position, and in the same way as above, the hydraulic pressure of the front clutch is released. Since the chamber is connected to the drain side to release this internal pressure, a single valve can release hydraulic pressure for both upshifts and downshifts, which allows the control The cost of the valve can be reduced and it can be made smaller and more compact.

[Brief explanation of the drawing]

Fig. 1 is a schematic diagram showing the configuration of an automatic transmission, Fig. 2 is a hydraulic circuit diagram showing a control valve for controlling the automatic transmission, and Figs. 3 and 4 show an orifice control valve used in the above control valve. FIG. 2... Torque converter 3... Main shaft 4
...Counter shaft 6...Output shaft 30.
... Regulator valve 40 ... Manual valve 50.52.54 ... Shift valve 60 ... Orifice control valve 71.72.
・・Solenoid valve

Claims (1)

[Scope of Claims] 1) A valve that releases hydraulic pressure in a hydraulically operated clutch that was engaged before shifting during gear shifting in an automatic transmission, the clutch port communicating with a hydraulic chamber of the clutch. and a housing having a drain port that communicates with the drain side, an operating position that is inserted into the housing and that interrupts communication between the clutch port and the drain port, and a release position that allows the clutch port and the drain port to communicate with each other. The device comprises a spool movable between positions, and biasing means for biasing the spool toward the operating position, and is engaged with the housing when the gear is upshifted from the gear position at which the clutch is activated. an upshift side that communicates with a hydraulic chamber of an upshift side clutch and causes internal pressure of the upshift side clutch hydraulic chamber to act on the spool to move the spool to the release position against the urging force of the urging means; The port communicates with the hydraulic chamber of the downshift side clutch that is engaged when the gear is downshifted from the gear position at which the clutch is activated, so that the internal pressure of the downshift side clutch hydraulic chamber acts on the spool to cause the spool to A hydraulic release valve for a hydraulically operated clutch, characterized in that a downshift side port is formed to move the clutch to the release position against the urging force of the urging means.