JPH0276968A - Oil pressure control device for automatic speed change gear - Google Patents

Abstract

PURPOSE:To perform regulation of an oil pressure feed and discharge timing in relation to further more speed change motions by providing a control means which control the working position of a timing valve during various given speed change motions. CONSTITUTION:A timing valve 103 is situated astride first - third bypass lines 153-155 bypassing an orifice 73 on a servo apply line 120, an orifice 82 (and 81) on a servo release line 126, and a stationary orifice 78 (and an orifice 79) on a second drain line 123 having a 3-4 clutch pressure. Through the working of a fifth solenoid valve 104, the first - third bypass lines 153-155 are released and shut off to control an oil feed and discharge timing during 1-2 shift up speed change, during 3-2 shift down speed change, and during 4-2 shift down speed change. This constitution enables execution of excellent various speed change motions.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a hydraulic control device for an automatic transmission, and more particularly to a hydraulic control device for an automatic transmission, and particularly to one that appropriately controls the operation timing of a frictional engagement element during a speed change operation.

(Prior Art) Automatic transmissions generally installed in automobiles combine a torque converter and a speed change gear mechanism, and the power transmission path of this speed change gear mechanism is controlled by selectively operating multiple friction engagement elements such as clutches and brakes. This type of automatic transmission is equipped with a hydraulic control circuit that controls the supply and discharge of hydraulic pressure to the actuators of each of the friction and engagement elements mentioned above. It will be done. Specifically, this hydraulic control circuit consists of a regulator pulp that adjusts the discharge pressure of the oil pump to a predetermined line pressure, a manual pulp that changes the range by manual operation, and a manual pulp that operates according to the operating state and controls each of the above-mentioned actuators. It is composed of a plurality of shift valves that selectively operate a plurality of frictional engagement elements by switching the oil passages through which they flow, and various valves that perform other auxiliary functions. As disclosed in Japanese Patent Publication No. 62-246652, there are cases in which the shift valve is driven by a solenoid valve so that the shift control is adapted to the operating conditions and performed with higher accuracy.

By the way, in this type of automatic transmission, the timing of the engagement or release operation of the friction engagement element during each gear shift is important for obtaining a good gear shift operation. If the movement is too fast or the releasing movement of the friction engagement element to be released is too slow, the transmission mechanism will temporarily enter a so-called double lock state and the output torque will drop, and vice versa, the transmission mechanism will temporarily become locked. This causes problems such as the engine becoming in a neutral state and causing the engine to run dry. Therefore, in order to solve this problem and perform the gear shifting operation favorably, the oil pressure control circuit adjusts the timing of supplying and discharging hydraulic pressure to the friction engagement element (actuator) during gear shifting.

This timing adjustment is basically done by installing an orifice with an appropriately set diameter in the oil passage leading to each actuator, but if the optimal timing cannot be obtained by orifice setting alone, further orifice setting is required. In some cases, a bypass passage is provided, and a valve for opening and closing the bypass passage is installed on the bypass passage.

In other words, by operating this valve during a shift operation, for example, during the first half of the shift operation, hydraulic pressure is rapidly supplied and discharged through the bypass passage, and during the second half, hydraulic pressure is supplied and discharged slowly through the orifice. It performs precise control of hydraulic supply and discharge timing.

(Problem to be Solved by the Invention) However, as described above, there are only one valve that controls the timing of supplying and discharging hydraulic pressure by opening and closing the bypass passage.
Therefore, if you try to control the hydraulic supply/discharge timing as described above for multiple shift operations between each gear stage, the hydraulic control circuit will become significantly complicated. Become. Therefore, in the past, the actual situation is that this timing control has only been performed for a limited number of specific speed change operations.

The present invention deals with the above-mentioned actual situation in automatic transmissions, and has the object of making it possible to adjust the hydraulic pressure supply timing for more shift operations without significantly complicating the hydraulic control circuit. do.

(Means for Solving the Problems) In order to solve the above problems, the following means are used in the hydraulic control device for an automatic transmission according to the present invention.

That is, it has a speed change gear mechanism, a plurality of friction engagement elements for switching the power transmission path of the speed change gear mechanism, and a hydraulic control circuit provided with a plurality of oil passages each communicating with the hydraulic actuators of these friction engagement elements. In the automatic transmission configured to change speed by switching the oil passages, among the oil passages in the hydraulic control circuit, a plurality of oil passages supply and discharge hydraulic pressure independently from each other during a predetermined plurality of gear shifting operations. The oil passages are provided with bypass passages that bypass the orifices provided in these oil passages, and a timing valve is provided spanning these bypass passages to control the communication state of each bypass passage using a single spool. A control means is provided for controlling the operating position of the timing valve during the plurality of predetermined speed change operations.

(Function) According to the above configuration, for example, the oil passage that supplies hydraulic pressure to a predetermined frictional engagement element at the time of a 1-2 upshift, and the 3-2
These oil passages are provided with an oil passage that discharges hydraulic pressure from a predetermined friction engagement element during a downshift and an oil passage that discharges hydraulic pressure from a predetermined friction engagement element during a 4-2 downshift. Assuming that bypass passages are provided to bypass each orifice, and a timing valve is provided so as to straddle these bypass passages,
This one timing valve and its control means control the oil pressure supply timing during the 1-2 upshift, the oil pressure discharge timing during the 3-2 downshift, and the oil pressure during the 4-2 downshift. The discharge timing of the oil is precisely and optimally adjusted in conjunction with the action of the orifices provided in each oil passage. In addition, the setting of the diameter of the orifice and the timing of operation of the timing valve in that case can be done in each shift operation without affecting other shift operations, and in this way, the hydraulic control circuit can be significantly complicated. Many gear shifting operations can be performed satisfactorily without causing any problems.

(Example) Examples of the present invention will be described below.

First, the mechanical configuration of the automatic transmission according to this embodiment will be explained with reference to FIG. It has a mechanism 30, a plurality of frictional engagement elements 41 to 46 such as clutches and brakes, and one-way clutches 51 and 52 that switch the power transmission path of the mechanism 30, and these act as a driving range. Each of the H ranges, 1st to 4th speeds in the D range, 1st to 3rd speeds in the 2nd range, and 1st to 2nd speeds in the lunge are available.

The torque converter 20 includes a pump 22 fixedly installed in a case 21 connected to the engine output shaft 1, and a turbine 23 disposed opposite to the pump 22 and driven by the pump 22 via hydraulic oil. , a stator 25 that is interposed between the pump 22 and the turbine 23 and supported by the transmission case 11 via the one-way clutch 24 to increase torque; and the case 21 and the turbine 2
3, and a lock-up clutch 26 that directly connects the engine output shaft 1 and the turbine 23 via the case 21. Then, the turbine 23
The rotation is outputted to the speed change gear mechanism 30 side via the turbine shaft 27. Here, a pump shaft 12 passing through the turbine shaft 27 is connected to the engine output shaft 1, and the shaft 12 drives an oil bong 713 provided at the rear end of the transmission.

On the other hand, the speed change gear mechanism 30 is composed of a Ravigneau type planetary gear device, and includes a small sun gear 31 with a small diameter loosely fitted on the turbine shaft 27, and a small sun gear 31 that is loosely fitted onto the turbine shaft 27.
1, a large diameter large sun gear 32 loosely fitted on the turbine shaft 27, a plurality of short pinion gears 33 meshed with the small sun gear 31, and a front half meshed with the short pinion gear 33. It is composed of a long pinion gear 34 whose rear half meshes with the large sun gear 32, a carrier 35 that rotatably supports the long pinion gear 34 and the short pinion gear 33, and a ring gear 36 which meshes with the front half of the long pinion gear 34. has been done.

A forward clutch 41 and a first one-way clutch 51 are interposed in series between the turbine shaft 27 and the small sun gear 31, and a coast clutch 42 is interposed in parallel with these clutches 41 and 51. In addition, the turbine shaft 27 and carrier 35
A 3-4 clutch 43 is interposed between the turbine shaft 27 and the large sun gear 32, and a reverse clutch 44 is interposed between the turbine shaft 27 and the large sun gear 32. Further, a 2-4 brake 45 consisting of a band brake for fixing the large sun gear 32 is provided between the large sun gear 32 and the reverse clutch 44, and the carrier 35
A second one-way clutch 52 that receives and stops the reaction force of the carrier 35, and a low reverse brake 46 that fixes the carrier 35 are provided in parallel between the transmission case 11 and the transmission case 11. The ring gear 36 is connected to the output gear 14, and rotation is transmitted from the output gear 14 to left and right wheels (not shown) via a differential gear.

Here, the frictional engagement elements 4 such as the above-mentioned clutches and brakes, etc.
To explain the relationship between the operating states of 1 to 46 and one-way clutches 51 and 52 and the gears, first, in 1st gear,
The forward clutch 41 is engaged and the first. The second one-way clutch 51,52 becomes locked. Therefore, the output rotation of the torque converter 20 is input from the turbine shaft 27 to the small sun gear 31 of the planetary gear device 30 via the forward clutch 41 and the first one-way clutch 51. In this case, since the carrier 35 is fixed by the action of the second one-way clutch 52, the planetary gear device 30 performs a differential operation that transmits rotation from the small sun gear 31 to the ring gear 36 via the short pinion gear 33 and the long pinion gear 34. It operates as a fixed gear train. As a result, a first speed state with a large reduction ratio corresponding to the ratio of the diameters of the small sun gear 31 and the ring gear 36 is obtained.

Next, in 2nd gear, in addition to the above 1st gear state, 2-
The four-brake 45 is engaged, the large sun gear 32 in the planetary gear device 30 is fixed, and the second one-way clutch 52 is idled. Therefore, the rotation transmitted from the turbine shaft 27 to the small sun gear 31 is transmitted to the long pinion gear 34 via the short pinion gear 33, and the large sun gear 32 meshing with the long pinion gear 34 is fixed. It revolves on the large sun gear 32, and the carrier 35 rotates accordingly.

As a result, the rotation of the carrier 35 (
The ring gear 36 rotates by the amount of revolution of the long pinion gear 34).
The rotation speed of the engine is increased, and a second speed state where the reduction ratio is smaller than that of the first speed is obtained.

Furthermore, in 3rd gear, from the above 2nd gear state, 2;4
At the same time as the brake 45 is released, the 3-4 clutch 4
3 is concluded. Therefore, the rotation of the turbine shaft 27 is input to the small sun gear 31 via the forward clutch 41 and the first one-way clutch 51, and at the same time, the rotation is input to the small sun gear 31 via the 3-4 clutch 43 to the carrier 35.
will also be entered. As a result, a third speed state is obtained in which the entire planetary gear device 30 rotates integrally and the ring gear 36 rotates at the same speed as the turbine shaft 27.

In addition, in 4th gear, the 2nd gear that was once released in 3rd gear is
-4 Brake 45 is re-engaged. Therefore, the rotation of the turbine shaft 27 is input from the 3-4 clutch 43 to the carrier 35 of the 1-rate gear device 30, causing the long pinion gear 34 to revolve. 2
Since it is fixed by the -4 brake 45, the long pinion gear 34 rotates while revolving together with the carrier 35. As a result, the long pinion gear 34
The ring gear 36 that meshes with the carrier 35 (rotation of the turbine shaft 27) is rotated at an increased speed by the rotation of the long pinion gear 34, thereby obtaining a fourth speed in an overdrive state. In this case, although the forward clutch 41 is in the engaged state, the first one-way clutch 51 in series with it is idle, so the rotation of the turbine shaft 27 is not input to the small sun gear 31.

Further, at reverse speed, the reverse clutch 44 and the low reverse brake 46 are engaged, the rotation of the turbine shaft 27 is input to the large sun gear 32 of the planetary gear device 30, and the carrier 35 of the gear device 30 is fixed. . Therefore, the large sun gear 32
Rotation is transmitted through a fixed gear train from 1 to 34 to the ring gear 36 via the long pinion gear 34, and a reduction ratio corresponding to the ratio of the diameters of the large sun gear 34 and the ring gear 36 is obtained. If ring gear 3
The rotational direction of 6 is opposite to the rotational direction of the turbine shaft 2-7 or large sun gear 32.

Note that the first one-way clutch 51, which transmits rotation in 1st to 3rd gears, and the second one-way clutch 52, which receives no reaction force in 1st gear, idle during coasting, so the engine brake does not operate in these gears. However, in the 3rd gear of the D range, the 2nd and 3rd gears of the 2nd range, and the 1st and 2nd gears of the lunge, the coast clutch 42 parallel to the first one-way clutch 51 is engaged, and in the 1st gear of the lunge, the coast clutch 42 is engaged. Since the low reverse brake 46 is engaged in parallel with the one-way clutch 52, engine braking is provided in these gears.

To summarize the relationship between the operation of each of the hydraulic engagement elements 41 to 46 and the one-way clutch 51, 52 and the gear position, the first
It will look like a table.

(Hereinafter, blank space) Next, referring to FIG. 2, a hydraulic control circuit for supplying and discharging hydraulic pressure to the actuators of each of the above-mentioned hydraulic fastening elements 41 to 46 will be explained.
The hydraulic actuator 45' of the -4 brake 45 is composed of a servo piston having an apply boat 45a' and a release boat 45b', and engages the 2-4 brake 45 when hydraulic pressure is supplied only to the apply boat 45a'. , when both boats 45a', 45b' are not supplied with hydraulic pressure, and both boats 45a'.

The 2-4 brake 45 is released when hydraulic pressure is supplied to both brakes 45b' and 45b'. Further, the actuators of the other frictional fastening elements 41 to 44 and 46 are constituted by ordinary hydraulic pistons, and are adapted to fasten the frictional fastening elements when hydraulic pressure is supplied.

This hydraulic control circuit 60 includes, as main components, a regulator valve 61 that adjusts the pressure of the hydraulic oil discharged from the oil bong 13 to the main line 110 to a predetermined line pressure as shown in FIG. A manual valve 62 that performs selection, and each shift valve 63, 64. 65 is provided.

The manual valve 62 has an input boat e into which line pressure is introduced from the main line 110, and first to fourth output boats a to d, and by movement of the spool 62a,
The input port e is the 1st in the D range and the 2nd range.
Second output boat a.

b, the first in Lunge. It is connected to the third output ports a and C, and in the R range, to the fourth output port d. First to fourth output lines 111 to 114 are connected to each of the output ports a to d, respectively.

In addition, the above 1-2.2-3.3-4 shift pulp 63,
64.65 are spools 63a, 64a, 65, respectively.
A is biased toward the right side in the drawing by a spring (not shown), and pilot boats 63b, 64b, and 65b are provided on the right side of these spools. and,
The first pilot line 115 led from the main line 110 is connected to the pilot boat 63b of the 1-2 shift valve 63, and the 2-3, 3-4 shift valve 64, 65
The pilot boats 64b and 65b are connected to a second output line branched from the first output line 111 via a line 116.
A third pilot line 117.1.18 is connected respectively, and these pilot lines 115,
117 and 118 each have 1. Second. A third solenoid valve 66,67,68 is provided. These solenoid valves 66 to 68 drain the pilot lines 115, 117, and 118 when they are ON, respectively, to discharge the pilot pressure in the pilot boats 63b to 65b of the corresponding shift valves 63 to 65. , the spools 63a to 65a are located on the right side in the drawing, and the pilot boat 63 is
Each pilot line 115, 117, 11 from b to 65b
Pilot pressure is introduced from 8 to spools 63a to 6.
5a are respectively positioned on the left side.

Here, these solenoid valves 66 to 68 are turned ON and OFF based on a map preset according to the vehicle speed and engine throttle opening according to signals from the control circuit. shift valve 6
By switching the positions of the spools 63a to 65a of 3 to 65 and switching the oil passages leading to the respective frictional fastening elements 41 to 46, these frictional fastening elements 41 to 46 are fastened in the combinations shown in Table 1, This allows the gear stage to be changed depending on the operating condition. In that case, each gear stage and each solenoid valve 66 to 68 are turned on and off.
The relationship with the combination pattern is set as shown in Table 2, and in particular, when the 3-2 downshift is performed, the intermediate pattern shown in the table is used.

(Hereinafter, blank space) On the other hand, the first to fourth output lines 111 to 1 connected to each output boat a to d in the manual pulp 62
14, the above-mentioned line 116 is branched from the first output line 111 that communicates with the main line 110 in each of the forward ranges D and 2.1, and this line 116 is used as a forward clutch line and connects the one-way orifice 71. It is led to the forward clutch 41 via the forward clutch 41. Therefore, D.2. During lunge, the forward clutch 41 is always engaged. Here, an N-D accumulator 72 for buffering when the forward clutch is engaged is connected to the forward clutch line 116 via a line 119.

Further, the first output line 111 is guided to the 1-2 shift valve 63, and when the first solenoid valve 66 is turned on and the spool 63a is positioned to the right, it communicates with the servo apply line 120, and is connected to the one-way orifice 73.
Apply boat 45a of servo piston 45a via
′.

Therefore, D.2. When the first solenoid pulse 166 is ON in the lunge, that is, in the 2nd and 3rd gears in the D range, in the 2.3rd gear in the 2nd range, and in the 2nd speed in the lunge, the above apply bow)
The 2-4 brake 45 is engaged when hydraulic pressure (servo apply pressure) is introduced into the release boat 45a' and no hydraulic pressure (servo release pressure) is introduced into the release boat 45b'. A 1-2 accumulator 74 for buffering when the 2-4 brake is engaged is also connected to the servo apply line 120.

Further, the second output line 112 communicating with the main line 110 in the D and 2 ranges is led to a 2-3 shift valve 64. Then, when the second solenoid valve 67 is OFF and the spool 64a is located on the left side, the line 112 is connected to 3-4 through the one-way orifice 75.
It communicates with the clutch line 121. This line 121 further passes through the one-way orifice 76 to the 3-
4 clutch 43 is reached. Therefore, when the second solenoid valve 67 is OFF in the D, 2 range, that is, in the D range, the 3
, 4th speed, and 3rd speed of the 2nd range, the 3-4 clutch 43 is engaged.

Here, from the 3-4 clutch line 121, the first clutch line 121 is connected to the first clutch line 121.
The second drain lines 122 and 123 are branched, and the first drain line 122 is connected to the 3-4 shift valve 65.
When the third solenoid valve 68 is OFF (the spool 65a is on the left 01), it is connected to the line 124 and connected to the drain boat of the 2-3 shift valve 64. Further, the second drain line 123 includes a one-way orifice 77, a fixed orifice 78, and a one-way orifice 7.
9 to the 3-4 shift valve 65, and when the third solenoid valve 68 is ON (the spool 65a is on the right side), it communicates with the above line 124 and leads to the drain boat of the 2-3 shift valve 64. . In other words, during the 3-2 and 4-2 downshifts in which oil pressure (3-4 clutch pressure) is discharged from the 3-4 clutch 43, the intermediate pattern in which the third solenoid valve 68 shown in Table 2 is OFF is selected. 1st drain line 1 when downshifting via 3-2
22, and when the third solenoid valve 68 is held ON during the 4-2 downshift, the second drain line 1 is
23, the 3-4 clutch pressure will be discharged.

Note that a 2-3 accumulator 80 is connected between the one-way orifice 77 and the fixed orifice 78 of the second drain line 123 for buffering when the 3-4 clutch is operated.

Further, it is connected to the first drain line 122, and the 3-
Similarly to the 4 clutch line 121, the line 125 that communicates with the second output line 112 when the second solenoid valve 67 is OFF and the spool 64a of the 2-3 shift valve 64 is located on the left side is connected to the 3-4 shift valve. 65, and when the third solenoid valve 68 is OFF, the spool 6
When 5a is located on the left side, the servo release line 12
6. This line 126 leads to the release port 45b' of the servo piston 45a via a one-way orifice 81.82. Therefore, D, the second
．． When both the third solenoid valves 67 and 68 are OFF, that is, in the 3rd speed of the D range and the 3rd speed of the 2nd range, servo release pressure is introduced to the release bow) 45b' of the servo piston 45a, and the 2-4 brake 45 is activated. To be released.

Furthermore, a line 1 branched from between the two one-way orifices 81 and 82 of the servo release line 126
27 communicates with the coast clutch line 128 via the coast control valve 83, one-way orifice 84, and ball valve 85, and reaches the coast clutch 42.

Therefore, the coast clutch 42 is engaged in the 3rd speed of the D range and the 3rd speed of the 2nd range where hydraulic pressure is introduced into the servo release line 126. On the other hand, when the third solenoid valve 68 is OFF, the spool 65a of the 3-4 shift valve 65 is located on the left side, and the second solenoid valve 67 is
is ON and the spool 64a of the 2-3 shift valve 64 is located on the right side, the forward clutch line 1
16 is its branch line 129.3-4 shift valve 6
5, communicates with line 131 via line 130 and 2-3 shift valve 64. This line 131 further leads to the coast clutch line 128 via the ball valve 85, and therefore the coast clutch 42 is connected to the second coast clutch line 128.
It is also engaged when the solenoid valve 67 is ON and the third solenoid valve 68 is OFF, that is, in the 2nd gear of the 2nd range and the 1.2nd gear of the lunge.

Further, the third output line 113, which is connected to the main line 110 by the manual valve 62, is connected to the low reducing valve 86 as a pressure reducing valve and the line 1.
32 to the 1-2 shift valve 63.

This line 132 is connected to the first solenoid valve 6
6 is OFF and the spool 63a is located on the left side,
The low reverse brake line 133 is connected to the low reverse brake line 133 through the one-way orifice 87 and the ball valve 88 . leading to. Therefore, when the first solenoid valve 66 is off during lunge, that is, when the lunge is in first gear, the low reverse brake 46 is engaged.

Furthermore, a fourth line that communicates with the main line 110 in the R range
The output line 114 is connected to the low reverse brake line 1 via a line 134 branched from the line 114, the one-way orifice 89, and the ball valve 88.
33, and becomes a reverse clutch line 135, which leads to the reverse clutch 44 via a one-way orifice 90. Therefore, in the R range, the low reverse brake 46 and reverse clutch 44 are always engaged. Here, an N-R accumulator 91 for the M section when the reverse clutch is engaged is connected to the reverse clutch line 135.

The hydraulic control circuit 60 also includes a lock-up valve 92 for operating the lock-up clutch 26 in the torque converter 20 shown in FIG.

A torque converter line 136 is led from the regulator valve 61 to this valve 92, and a pilot boat 92b provided at one end is connected to a hydraulic pressure branched from the main line 11O and reduced by a solenoid reducing valve 93. A pilot line 137 is connected thereto. And this line 13
7 is provided with a fourth solenoid valve 94 for lock-up, and when the valve 94 is ON, the spool 92a is located on the right side, so that the torque converter line 136 is connected to the torque converter in-line 138 leading into the torque converter 20. As a result, the internal pressure of the torque converter 20 increases and the lock-up clutch 2
6 is concluded. Also, the solenoid valve 94 is
When the FF is activated and the spool 92a moves to the left, the torque converter line 136 communicates with the lock-up release line 139, lock-up release pressure is introduced into the torque converter 20, and the lock-up clutch 26 is released. It has become.

Further, this hydraulic control circuit 60 includes a line pressure control circuit for controlling the line pressure adjusted by the regulator valve 61.
A throttle modulator valve 95, a duty solenoid valve 96 for actuating the valve, and a cutback valve 97 are provided.

The throttle modulator valve 95 is connected to a line 14 branched from a line 137 that communicates with the main line 110 via the solenoid reducing valve 93.
0 is introduced, and a pilot pressure adjusted by a duty lenoid valve 96 that opens and closes periodically is introduced into one end of the spool 95a, and the duty rate of this duty lenoid valve 96 (opening during one cycle) is introduced into one end of the spool 95a. The throttle modulator pressure is generated according to the time ratio). In that case, the duty rate is set according to the throttle opening of the engine, and the corresponding throttle modulator pressure is introduced to the pressure booster boat 61a of the regulator valve 61 through the line 141, so that The valve 61
The line pressure adjusted by the line pressure will be increased in accordance with the increase in the engine throttle opening.

Further, a line 142 branched from a line 141 that supplies the throttle modulator pressure to the regulator valve 61 is led to the carbon dioxide pump valve 97, and a line 142 is connected to the first to third bows) 97b, 97c, 97d.
The pilot pressure generated when the first solenoid valve 66 is OFF is supplied to the first boat 97b via the line 143, and the pilot pressure generated when the second solenoid valve 67 is OFF is transmitted to the second boat 92c. The pilot pressure generated when the third solenoid valve 68 is OFF is introduced to the third boat 97d via the line 144, and the pilot pressure generated when the third solenoid valve 68 is OFF is introduced via the line 145. It has become. Then, the spool 97a moves according to the introduction state of these pilot pressures, and the pilot pressure is introduced only to the first boat 97b (only the first solenoid valve 66 is OFF). 1st speed, 1st and 3rd boats 97b
, 97d (first and third solenoid valves 66, 68 are OFF), and pilot pressure is introduced only to the third port 97d (only the third solenoid valve 68 is OFF). The line 142 is cut off at the 2nd speed of the 2nd range (OFF) and the 2nd speed of the lunge, and the line 142 is connected to the line 146 at all gears other than these, and the throttle valve is connected to the pressure reducing boat 61b of the regulator valve 61. By introducing the modulator pressure, the line pressure is reduced.

In addition to the above configuration, this hydraulic control circuit 60 includes, in addition to the coast control valve 83, a bypass valve 101.2-3 control valve 102, for adjusting the supply and discharge timing of hydraulic pressure during each gear shift. A timing valve 103 is also provided, which is a feature of the present invention.

As described above, the coast control valve 83 is provided on the line 127 which is branched from the servo release line 126 and leads to the coast clutch line 128 via the ball valve 85, and is also branched from the forward clutch line 116. Line 147 transfers line pressure (forward clutch pressure) to spool 83.
It is led to one end of a. When the servo release pressure introduced into the other end of the spool 83a by the line 127 and the biasing force of the spring overcome the line pressure, the line 127 is brought into communication. Therefore, through this line 127, the coast clutch 42
During 2-3 upshifts in D and 2 ranges where coast clutch pressure is supplied to
The coast clutch 42 is engaged after the 2-4 brake 45 and the coast clutch 42 are securely released, and double locking caused by the 2-4 brake 45 and the coast clutch 42 being engaged simultaneously is prevented. Since the line pressure is guided to the line 127, the timing at which the line 127 is communicated is changed according to the line pressure, and the correspondence between the communication timing and the pressure level of the servo release pressure is appropriately set. It turns out.

Further, the bypass valve 101 is provided on a bypass line 148 that bypasses the one-way orifice 76 provided in the 3-4 clutch line 121, and the hydraulic pressure downstream of the one-way orifice 76 in the 3-4 clutch line 121 is (3-4 clutch pressure) is introduced into one end of the spool 101a, and a modulator pressure is introduced into the other end of the spool 101a through lines 149 and 150 led from the throttle modulator valve 95, so that the 3-4 clutch pressure is maintained at a predetermined level. The bypass line 148 is cut off when the spool 101a moves to the left due to the rise above the specified value. Therefore, the 3-4 clutch pressure is quickly supplied by the 4-way bypass line 148 at the beginning of the supply, but thereafter the supply is slowed by the one-way orifice 76, and thus the 2-
The engagement timing of the 3-4 clutch 43 during the 3rd upshift is adjusted, and the timing is changed in accordance with the throttle opening of the engine.

Further, the 2-3 control valve 102 is provided on the bypass line 151 that bypasses the one-way orifice 81 that performs a throttling action in the hydraulic pressure supply direction on the servo release line 126, and is also provided on the spool 10.
The hydraulic pressure (3-4 clutch pressure) in the 3-4 clutch line 121 is applied to one end of 2a, and the line 149 is applied to the center of the 2a.
The aforementioned throttle modulator pressure is introduced through the line 152 and the servo release pressure downstream of the bypass line 151 is introduced into the other end. Then, the bypass line 151 is opened or drained by the action of the 3-4 clutch pressure, throttle modulator pressure, and servo release pressure, and the servo release pressure is regulated in accordance with the 3-4 clutch pressure. There is.

On the other hand, the timing valve 103 constituting the characteristic part of the present invention
a first bypass line 153 that bypasses the one-way orifice 73 on the servo apply line 120;
A second bypass line 154 bypasses the one-way orifice 82 (and 81) on the servo release line 126, and a second bypass line 154 bypasses the fixed orifice 78 (and one-way orifice 79) in the 3-4 clutch pressure second drain line 123. 3 bypass line 15
It is located across 5. And spool 103
A pilot line 157 led from the main line 110 via a line 156 is connected to one end of a, and the fifth solenoid pulp 104 is provided on the line 157.

The timing valve 103 opens and shuts off the first to third bino f-slines 153, 154, 155 by the operation of the fifth solenoid valve 104, thereby opening and closing the first to third bino f-slines 153, 154, and 155 during a 1-2 upshift and a 3-2 downshift. time, and 4
The timing valve 103 controls the supply and discharge timing of hydraulic pressure during the -2 downshift.Next, the specific operation of the timing valve 103 during each speed change will be explained with reference to FIG. 3 and subsequent figures.

First, during the 1-2 shift up, when the spool 63a of the 1-2 shift valve 63 does not move from the left side to the right side by switching the first solenoid valve 66 from OFF to ON, the first output line 111 By communicating with the servo apply line 120, servo apply pressure is supplied to the apply boat 45a' of the servo piston 45' via the one-way orifice 73, and the 2-4 brake 45 is thereby engaged.
During this shift operation, the fifth solenoid pulp 104 for operating the timing valve is first switched from OFF to ON at the start of the shift, as shown in FIG. Therefore, the spool 103a of the timing valve 103 moves to the right,
A first bypass line 153 that bypasses the one-way orifice 73 is connected. Therefore, in the first half of the shift operation, the servo apply pressure is
5a'.

Then, when a predetermined time t1 has elapsed from the start of the gear shift during gear shifting, the fifth solenoid pulp 104 is switched from ON to OFF again, and the spool 103a of the timing valve 103 moves to the left, causing the first solenoid pulp 104 to move to the left.
The bypass line 153 is shut off, and therefore, in the latter half of the shift operation, the servo apply pressure is applied to the one-way orifice 7.
Apply boat 45 of servo piston 45' through 3
It will be supplied to a'. As a result, this 1-2
The change in servo apply pressure during upshifting is as shown in Figure 4. In particular, the piston travel time T at the beginning of the shifting operation is shortened, the time lag of the upshifting operation is reduced, and the time lag at the later stage of the shifting operation is reduced. By the action of the one-way orifice 73 and the 1-2 accumulator '7-4 shown in FIG. 2, smooth gia add-up is realized.

Next, during a 3-2 downshift in the D range, as shown in Figure 5, the second and third solenoid valves 67 and 68 are both OFF before the start of the shift operation and ON after the shift operation is completed. However, during gear shifting, the second solenoid valve 6
7 is turned ON, the third solenoid pulp 68 is turned OFF,
Therefore, during gear shifting, the spool 64 of the 2-3 shift valve 64
a is located on the right side, and the spool 65a of the 3-4 shift pulp 65 is located on the left side. Therefore, the servo release pressure supplied to the release port 45b' of the servo piston 45' is shifted to 2-3 through the line 126, one-way orifice 82, 81, 3-4 shift valve 65, line 125 and one-way orifice 75. The drain of the valve 64 will be discharged from the boat 64c, but during this shift, the fifth solenoid valve 104 is first switched from OFF to ON at the start of the shift, similar to the 1-2 shift up shift. The predetermined time t
After 2 lapses, it is switched OFF again. Then, along with this, the spool 103 of the timing valve 103 first moves to the right side to open the second bypass line 154,
Thereafter, it moves to the left and blocks the second bypass line 154. Therefore, the servo release pressure is quickly discharged by the second bypass line 154 during the first half of the speed change operation, and is slowly discharged by the one-way orifice 82 that performs a throttling action in the discharge direction on the line 126 during the second half. Here, the second bypass line 154
A fixed orifice 105 is also provided, but this orifice 105 is set to have a diameter sufficiently larger than that of the one-way orifice 82.

On the other hand, during this 3-2 downshift, the 3-4 clutch pressure is discharged from the 3-4 clutch 43, but in this case, as mentioned above, the third solenoid pulp 68 is OFF and the 3-4 shift is Since the spool 65a of the valve 65 is located on the left side, the 3-4 clutch pressure is
1. One-way orifice 76 that does not receive throttling action,
It passes through the second drain line 122.3-4 shift valve 65 and line 124 and is quickly discharged from the drain port 64c of the 2-3 shift valve 64. Therefore, during this 3-2 downshift, as shown in FIG. 5, the 3-4 clutch 43 is released early and the engine speed quickly increases, and the bypass that controls the discharge of the servo release pressure By setting the opening time t2 of the line 154 and the diameter of the one-way orifice 82, it is possible to complete the engagement of the 2-4 brake 45 at the same time as the engine speed stops increasing, allowing for quick and smooth operation. A speed change will be realized.

Furthermore, during the 4-2 downshift, the above 3
The 3-4 clutch pressure is discharged in the same way as during the -2 downshift, but in this case, the third solenoid valve 68 is turned on.
The spool 6 of the 3-4 shift valve 65 is held in place.
5a is held in the right position, the 3-4 clutch pressure cannot pass through the first drain line 122, and the second drain line 123 connects the one-way orifice 77, the fixed orifice 78, and the one-way orifice 79. It is discharged from the drain boat 64c of the 2-3 shift valve 64 through the 3-4 shift valve 65 and the line 124, and in this case is subjected to a throttling action by the fixed orifice 78. However, during this gear shift, as shown in FIG.
The spool 103a moves from the left side to the right side to cut off the third bypass line 155. Therefore, during this shift, the 3-4 clutch pressure is quickly discharged through the third bypass line 155 during the first half of the shift operation. In the second half of the speed change operation, the throttle action of the fixed orifice 78 works, and the 2-3 accumulator 80
Since the hydraulic oil is discharged from the 3-4 clutch to the second drain line 123, the 3-4 clutch pressure gradually decreases. By the way, during this 4-2 downshift, the one-way clutch 51 shown in FIG. 1 is locked from the idle state, but just before that, the third bypass line 155 is
By disconnecting the one-way clutch 51, the one-way clutch 51 can be locked in a state where the oil pressure is stable, and thereby a smooth shift can be realized without increasing the time lag of the shift operation.

Here, regarding this 4-2 downshift, the fixed orifice 7 on the second drain line 123 is
By reducing the diameter of 8, the same effect as above can be obtained. In this case, as shown in Figure 7, 3-4
A second clutch pressure drain line 123' is separated from the 2-3 accumulator 80 and
A bypass line 155' is provided to bypass the upper fixed orifice 78' (and one-way orifice 79), and a timing valve 103 is installed on this line 155'.
will be provided. The change in the 3-4 clutch pressure in this case is shown by the chain line in FIG.

Note that the orifices 73, 82, and 78 shown in the above embodiments
The servo apply line 120, servo release line 126, and 3-4 clutch pressure second drain line 123, each provided with The operating timing of the timing valve 103 on the bypass lines 153, 154, and 155 can be set to the optimum state without affecting other gear shifting operations.

(Effects of the Invention) As described above, according to the present invention, in an automatic transmission that switches gears by controlling the supply and discharge of hydraulic pressure to and from frictional engagement elements of a hydraulic control circuit, by providing one timing valve, a plurality of It becomes possible to appropriately set the timing for supplying and discharging hydraulic pressure in the gear shifting operation. This allows many single-speed operations to be performed successfully without significantly complicating this type of hydraulic control circuit.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention, and FIG. 1 is a schematic diagram showing the mechanical configuration of an automatic transmission, FIG. 2 is a circuit diagram showing a hydraulic control circuit, and FIG. 3 is a diagram showing main components of the hydraulic control circuit. Fig. 4.5.6 is a time chart showing the effects of this circuit during 2-3 upshifting, 3-2 downshifting, and 4-2 downshifting, respectively. is an enlarged circuit diagram of a main part of another embodiment. 10... Automatic transmission, 30... Speed change gear mechanism, 41
~46...Frictional engagement element, 73, 78.82...Orifice, 103...Timing valve, 104...
・Control means (solenoid valve), 120.123,1
26... Oil line (servo apply line, 3-4 clutch pressure second drain line, servo release line), 15
3,154.155...Bypass passage. Applicant: Mazda Motor Corporation

Claims (1)

[Claims] (1) A hydraulic control circuit including a speed change gear mechanism, a plurality of friction engagement elements for switching the power transmission path of the speed change gear mechanism, and a plurality of oil passages each communicating with the hydraulic actuators of these friction engagement elements. and a hydraulic control device for an automatic transmission configured to change gears by switching each of the oil passages, wherein hydraulic pressure is supplied and discharged independently from each other during a predetermined plurality of gear shifting operations among the oil passages. A bypass passage that bypasses the orifice provided in each oil passage is provided in each of the plurality of oil passages that perform the action, and a single spool is provided that spans these bypass passages, and the communication state of each bypass passage is maintained by a single spool. 1. A hydraulic control device for an automatic transmission, comprising: a timing valve for controlling the timing valve; and a control means for controlling the operating position of the timing valve during the plurality of predetermined shift operations.