JP3291364B2 - Shift control method for automatic transmission - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a shift control method for an automatic transmission.

[0002]

2. Description of the Related Art Generally, an automatic transmission for an automobile is composed of a combination of a torque converter and a speed change mechanism and a power transmission path of the speed change mechanism, such as a clutch or the like, as disclosed in Japanese Patent Application Laid-Open No. 63-186055. The gears are switched by a selective operation of a plurality of frictional engagement elements such as brakes, so that the gear is automatically shifted to a predetermined gear.

[0003] Usually, as the above-mentioned friction fastening element,
2-4 shake that is engaged at the 2nd speed and 4th speed
Over key is provided. This brake is, for example, shown in FIG.
As shown in (a), a fastening chamber b and a release chamber c are provided before and after the piston a, and in the second speed or the fourth speed, pressure oil is supplied only to the fastening chamber b and the fastening state is established. Becomes 3
At the time of the first speed, both the engagement chamber b and the release chamber c are supplied with the pressure oil to be in the released state, and at the first speed, both the chambers b and c are released from the pressure oil to be in the released state. Have been. FIG. 10A shows the state of the third speed, FIG. 10A shows the state of the first speed, and FIG.
3) shows a state during the shift from the first gear to the second gear. FIG. 10B shows a change state of the hydraulic pressure in each chamber when shifting from the third gear to the second gear through the first gear, and the change state of the oil pressure in the engagement chamber b is indicated by a broken line. B
The state of change of the hydraulic pressure in the release chamber c is indicated by a dashed line C. In order to compare these changes, FIG.
(B) shows the change state of the hydraulic pressure of the 3-4 clutch by a solid line A.
Indicated by

[0004]

However, in the conventional 2-4 brake , when shifting from the first gear to the second gear, the piston b does not move smoothly, and the brake switching timing is delayed. Shock may occur, especially when shifting from the third gear to the second gear through the first gear. The cause of this is that when shifting from the third gear to the first gear, the pressure oil in the release chamber c is in a released state in which the pressure is released, but the oil itself remains and this oil is removed from the first gear to the second gear. This is because the piston a is compressed by the movement of the piston a toward the release chamber c at the time of shifting to the high gear and generates a pressure, that is, a residual pressure (FIG. 10).
(B)).

The present invention has been made in view of the above point, and an object of the present invention is to prevent the generation of the residual pressure in the release chamber c and reduce the shift shock. Is provided.

[0006]

In order to achieve the above object, a solution of the present invention comprises a friction fastening element having a fastening chamber and a release chamber provided before and after a piston, and the friction fastening element is provided with a friction fastening element. It is configured such that the fastening is performed when the pressure oil is supplied only to the fastening chamber, and the fastening is released when the pressure oil is supplied to both the fastening chamber and the release chamber or when the pressure oil is removed from both the chambers. Targets automatic transmissions.

Then, the speed change control in the automatic speed change range is performed.
Chi, initial pressure oil is supplied to the release chamber of the frictional engagement elements
From the gear stage , an intermediate change in which pressure oil is removed from both chambers.
The purpose is to supply pressurized oil only to the fastening chamber via the speed
When shifting to the shift speed , change from the initial shift speed to an intermediate
At the time of shifting to a higher gear, the gear is shifted through a state in which pressure oil is supplied to the engagement chamber and pressure oil in the release chamber is positively removed.

[0008]

According to the present invention, with the above structure, the automatic transmission
In the speed change control in the first stage, the initial speed (such as the third speed stage) in which the pressure oil is supplied to the release chamber of the frictional engagement element and the intermediate speed (where the pressure oil is removed in both the engagement chamber and the release chamber) When shifting to the 1st gear, etc.), the gear is shifted through a state in which pressure oil is supplied to the engagement chamber and the pressure oil in the release chamber is positively removed, so that oil remaining in the release chamber is reduced. Can be. Therefore, when shifting from the intermediate speed to the target speed (second speed, etc.) in which pressure oil is supplied only to the engagement chamber, no residual pressure is generated in the release chamber, and the friction engagement element The switching is performed smoothly without delay.

[0009]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows an automatic transmission AT for a vehicle with four forward speeds and one reverse speed, and the automatic transmission AT has a main component such as torque of an engine output shaft 1 (engine torque).
And a torque converter 3 for transmitting the torque to the turbine shaft 2 by shifting the speed. Further, the torque of the turbine shaft 2 is further shifted, and when the reverse gear is selected, the rotation is reversed and output from the output gear 4 to the drive wheel side. Transmission gear mechanism 5
And The turbine shaft 2 is formed in a pipe shape, and a pump shaft 6 connected to the engine output shaft 1 is disposed in a hollow portion thereof. ) Is rotationally driven.

The torque converter 3 has a pump 12 fixed in a case 11 connected to the engine output shaft 1.
And the turbine shaft 2 facing the pump 12.
And a stator 14 that is rotatively driven by hydraulic oil discharged from the pump 12 and that rectifies the hydraulic oil returning from the turbine 13 to the pump 12 in a direction that promotes the rotation of the pump 12. , Pump 1
The torque of the engine output shaft 1 is shifted at a speed ratio according to the difference between the rotation speeds of the engine 2 and the turbine 13. The stator 14 is fixed to a transmission case 16 via a one-way clutch 15 for the stator. A lock-up clutch 17 directly connects the engine output shaft 1 and the turbine shaft 2 as required.

On the other hand, the transmission gear mechanism 5 is composed of a Ravigneaux-type planetary gear device, and has a small-diameter small sun gear 21 loosely fitted to the turbine shaft 2 and a free-running gear turbine rearward from the small sun gear 21. The fitted large sun gear 22, a plurality of short pinion gears 23 (only one is shown) that mesh with the small sun gear 21, a front portion (the right side in FIG. 1) meshes with the short pinion gear 23, and a rear portion is the large pinion gear 23. Long pinion gear 24 meshing with sun gear 22
And a carrier 25 rotatably supporting the short pinion gear 23 and the long pinion gear 24, and a ring gear 26 meshing with the long pinion gear 24. In such a transmission gear mechanism 5, the small sun gear 21, the large sun gear 22, or the carrier 25 serves as a torque input unit according to the shift speed, while the ring gear 26 serves as a torque output unit at any shift speed. The ring gear 26 is connected to the output gear 4.

A plurality of clutches and brakes are provided as friction engagement elements for switching the torque transmission path in the transmission gear mechanism 5, that is, for switching the gear ratio or switching the rotation direction of the output gear 4. Have been.

That is, a forward clutch 31 is provided between the turbine shaft 2 and the small sun gear 21.
And a first one-way clutch 41 are interposed in series, and a coast clutch 32 is interposed in parallel with the two clutches 31, 41. A 3-4 clutch 33 is interposed between the turbine shaft 2 and the carrier 25, and a reverse clutch 34 is interposed between the turbine shaft 2 and the large sun gear 22. A 2-4 brake 35 composed of a band brake for fixing the large sun gear 22 at a predetermined shift speed is provided between the reverse clutch 34 and the reverse clutch 34. Further, between the carrier 25 and the transmission case 16, a low reverse brake 36 for fixing the carrier 25 at a predetermined shift speed and a second one-way clutch 42 for receiving a reaction force of the carrier 25 are provided in parallel. Have been. In the following description, the various clutches 31 to 34 and the brakes 35 and 36 will be collectively referred to as “friction engagement elements” as appropriate.

By changing the engagement / release patterns of the friction engagement elements 31 to 36, various ranges or gears as shown in Table 1 can be obtained. Hereinafter, with reference to Table 1, a description will be given of a torque transmission path and a shift characteristic thereof in each range or shift speed.

[0015]

[Table 1]

(1) In the case of the P range (parking range), all the friction engagement elements are turned off (released). In this case, the torque of the turbine shaft 2 is not transmitted to the transmission gear mechanism 5.

(2) In the case of the R range (reverse range), the reverse clutch 34 and the low reverse brake 36
And the other frictional fastening elements are released. Since the low reverse brake 36 is engaged, the second one-way clutch 42 disposed in parallel with the low reverse brake 36 has no particular effect. The first one-way clutch 41 is disengaged from the torque transmission path and does not exert any special action.

In this case, the torque of the turbine shaft 2 is transmitted through the reverse clutch 34 to the large sun gear 22.
Is input to Since the carrier 25 is fixed by the low reverse brake 36, the large sun gear 22, the long pinion gear 24, and the ring gear 26 function as a fixed gear train that meshes in this order.
Therefore, the torque input to the large sun gear 22 is transmitted through this gear train in the above order, and is shifted at a large reduction ratio determined by the number of teeth of the large sun gear 22 and the number of teeth of the ring gear 26. Is output. This R
In the range, the ring gear 26 (output gear 4) rotates in the direction opposite to the large sun gear 22 (turbine shaft 2), and the drive wheels are driven to the reverse side.

(3) N range (neutral range)
Is the same as in the P range.

(4) In the case of D range (drive range) first speed, the forward clutch 31 is engaged, and the other frictional engagement elements are released. The first and second one-way clutches 41 and 42 are normally in a locked state, but idle during coasting.

In this case, the torque of the turbine shaft 2 is sequentially input to the small sun gear 21 via the forward clutch 31 and the first one-way clutch 41. Since the carrier 25 is fixed by the second one-way clutch 42, the small sun gear 21
And short pinion gear 23 and long pinion gear 24
And the ring gear 26 function as a fixed gear train that meshes in this order. Therefore, the torque input to the small sun gear 21 is transmitted through the gear train in the order described above.
The gear is shifted at a large reduction ratio determined by the number of teeth of the small sun gear 21 and the number of teeth of the ring gear 26, and output to the output gear 4. In this case, the ring gear 26 (output gear 4) rotates in the same direction as the small sun gear 21 (turbine shaft 2), and the drive wheels are driven forward. still,
In the first speed of the D range, engine braking cannot be obtained due to the action of the first one-way clutch 41.

(5) In the case of the D range second speed, the forward clutch 31 and the 2-4 brake 35 are engaged, and the other frictional engagement elements are released. 1st one-way clutch 4
1 normally locks, but idles during coasting. The second one-way clutch 42 always idles.

In this case, since the large sun gear 22 is fixed, the long pinion gear 24 revolves around the large sun gear 22 while rotating. Therefore, the torque is basically transmitted through the same route as in the case of the D range first speed, but since the rotation speed of the ring gear 26 increases by the revolution of the long pinion gear 24, the torque is slightly reduced compared to the D range first speed. The ratio becomes smaller. In the second range of the D range, engine braking cannot be obtained due to the action of the first one-way clutch 41.

(6) In the case of the 3rd speed in the D range, the forward clutch 31, the coast clutch 32 and the 3-4 clutch 33 are engaged, and the other frictional engagement elements are released. Since the coast clutch 32 is engaged, the forward clutch 31 and the first one-way clutch 41 arranged in parallel with the coast clutch 32 do not exert any special action. The second
The one-way clutch 42 always idles.

In this case, since the small sun gear 21 and the carrier 25 are locked to each other via the coast clutch 32, the turbine shaft 2 and the 3-4 clutch 33, all the gears and the carrier 2 of the planetary gear device are set.
1-26 come to rotate integrally with being fixed,
The turbine shaft 2 and the output gear 4 are directly connected. Therefore, the torque of the turbine shaft 2 is transmitted to the output gear 4 without being shifted (reduction ratio 1). In this case, the output gear 4 rotates in the same direction as the turbine shaft 2, and the drive wheels are driven forward. In the third range of the D range, since the turbine shaft 2 and the output gear 4 are in a directly connected state, it is needless to say that engine braking can be obtained.

(7) In the case of D range 4th speed, forward clutch 31, 3-4 clutch 33 and 2-4 brake 3
5 are fastened and the other friction fastening elements are released. First
And the second one-way clutches 41 and 42 always idle. Since the first one-way clutch 41 always idles, although the forward clutch 31 is engaged,
Has no special effect.

In this case, the torque of the turbine shaft 2 is input to the carrier 25 via the 3-4 clutch 33, and the torque of the carrier 25 is sequentially transmitted to the output gear 4 via the long pinion gear 24 and the ring gear 26. Is transmitted. Since the large sun gear 22 is fixed by the 2-4 brake 35, the long pinion gear 24
Revolves around the large sun gear 22 while rotating. Therefore, the rotation speed of the ring gear 26 becomes higher than the rotation speed of the carrier 25, that is, the rotation speed of the turbine shaft 2 by the revolution of the long pinion gear 24, and the speed change gear mechanism 5
Becomes an overdrive (increased speed) state. The ring gear 26 (output gear 4) rotates in the same direction as the carrier 25 (turbine shaft 2), and the drive wheels are driven forward.

(8) In case of S range 1st speed, D range 1
It is the same as in the case of speed.

(9) In the case of the S-range second speed, the forward clutch 31, the coast clutch 32, and the 2-4 brake 35 are engaged, and the other frictional engagement elements are released. Since the coast clutch 32 is engaged, the forward clutch 31 and the first one-way clutch 41 arranged in parallel with the coast clutch 32 do not exert any special action.

In this case, the torque transmission path and the speed change characteristics are basically the same as those in the case of the second speed in the D range, but since the first one-way clutch 41 does not operate, engine braking can be obtained.

(10) In the case of the S range 3rd speed, it is the same as the case of the D range 3rd speed.

(11) In the case of the first speed in the L range, the forward clutch 31, the coast clutch 32 and the low reverse brake 36 are engaged, and the other frictional engagement elements are released. Since the coast clutch 32 is engaged, the forward clutch 31 and the first clutch
The one-way clutch 41 has no particular effect, and the low-reverse brake 36 is engaged. Therefore, the second one-way clutch 42 disposed in parallel with the one-way clutch
Has no special effect.

In this case, the torque transmission path and the shift characteristics are basically the same as those in the case of the first speed in the D range, but the first and second one-way clutches 41 and 42 do not operate, so that engine braking can be obtained. Will be.

(12) In the case of the second speed in the L range, it is the same as the case of the second speed in the S range.

Next, a hydraulic control circuit 60 which supplies and discharges hydraulic pressure to the actuators of the friction engagement elements 31 to 36 of the transmission gear mechanism 5 to perform engagement / release operations will be described with reference to FIGS. Here, among the above actuators, the hydraulic actuator 38 of the 2-4 brake 35
The fastening chamber 38b and the release chamber 38 are arranged before and after the piston 38a.
c, and the 2-4 brake 35 is engaged when the hydraulic pressure is supplied only to the engagement chamber 38b, and when the hydraulic pressure is supplied to both the chambers 38b and 38c or both are applied. Is released (released) by the biasing force of the spring 38d or the like. Other friction fastening elements 31 to 3
The actuators 4 and 36 are constituted by ordinary hydraulic pistons, and when the hydraulic pressure is supplied, the frictional engagement element is engaged, and when the hydraulic pressure is removed, the frictional engagement element is released.

The hydraulic control circuit 60 includes, as main components, a regulator valve 61 for adjusting the hydraulic pressure of the hydraulic oil discharged from the oil pump 7 to the main line 110 to a predetermined line pressure, and a manual operation. A manual valve 62 for selecting a range according to the speed, and a frictional engagement element (actuator) 3 which is operated in accordance with the gear position.
1-2, 2-3, 3 for supplying and discharging hydraulic pressure to 1-36
-4 are provided.

As shown in FIG. 4, the manual valve 62 includes an input port 62e into which line pressure is introduced from a main line 110, and first to fourth output ports 62a to 62e.
2d, the input port 62e is moved to the first and second output ports 62a and 62b in the D range and the S range, and to the first and third output ports 62a and 62c in the L range by the movement of the spool. In the R range, they are connected to the fourth output port 62d. The output ports 62a to 62d are connected to the first to fourth output lines 111 to 114, respectively. Also,
As shown in FIGS. 4 and 5, the above-mentioned 1-2, 2-3 and 3
The -4 shift valves 63, 64, and 65 each have a structure in which a spool is urged to the right in the drawing by a spring (not shown).
3a, 64a and 65a.

The pilot chambers 63a and 64a of the 1-2 shift valve 63 and the 2-3 shift valve 64 have:
First and second pilot lines 115 and 116 branched from the main line 110 are connected to each other. A third pilot line further branched from the second pilot line 116 is provided in a pilot chamber 65 a of the 3-4 shift valve 65. 117, and first, second and third solenoid valves 66, 6 for shifting are connected to these pilot lines 115-117, respectively.
7, 68 are provided. Each of the above solenoid valves 6
6 to 68 exclude the hydraulic pressures (pilot pressures) in the pilot chambers 63a to 65a of the corresponding shift valves 63 to 65 when the shift valves 63 to 65 are on.
5 is positioned on the right side of the drawing (in a state shown in the upper half from the axis) and the pilot chambers 63a to 65a of the corresponding shift valves 63 to 65 are turned off when the pilot lines 115 to 117 are turned off. By applying pressure, the spools of the shift valves 63 to 65 are positioned on the left side in the drawing (the state shown in the lower half from the axis).

On the other hand, among the first to fourth output lines 111 to 114 connected to the respective output ports 62a to 62d of the manual valve 62, they are communicated with the main line 110 in each forward range of D, S and L. A line 119 is branched from the first output line 111, and the line 119 is branched.
Is referred to as a forward clutch line, and is led to the forward clutch 31 via a one-way orifice 71. Therefore, the forward clutch 31 is always engaged in the D, S, and L ranges. The buffering accumulator 72 when the forward clutch is engaged is connected to the branch line 120 of the forward clutch line 119.

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 of the shift valve 63 is located on the right side, the servo apply line 121, and the engagement chamber 38 b of the 2-4 brake 35 through the one-way orifice 73 and the exhaust pressure control valve 74.
Leads to. Therefore, when the first solenoid valve 66 is ON in the D, S, L ranges, hydraulic pressure (servo apply pressure) is introduced into the fastening chamber 38b. The one-way orifice 73 is set to have such a diameter that the hydraulic oil is appropriately squeezed and discharged when the servo apply pressure is discharged.
The discharge pressure control valve 74 quickly discharges hydraulic oil at the start of servo apply pressure discharge, and gradually discharges hydraulic oil when the servo fly pressure decreases to a predetermined pressure. In addition, the above-mentioned Apple import 35b
Is connected via a line 122 to an accumulator 75 for buffering when the 2-4 brake is engaged.

The first output line 111 further comprises 3-4
The third solenoid valve 6 is also guided to the shift valve 65.
When 8 is off and the spool of the shift valve 65 is located on the left side, it communicates with the coast clutch line 123.
The coast clutch line 123 reaches the coast clutch 32 via the coast reducing valve 76 and the one-way orifice 77. Therefore, when the third solenoid valve 68 is off in the D, S, and L ranges, the coast clutch 32 is engaged.

On the other hand, the main line 110 in the D and S ranges
Are connected to the 2-3 shift valve 64. The line 112 is connected to the 2-3 shift valve 6 when the second solenoid valve 67 is off.
When the spool No. 4 is located on the left side, it communicates with the 3-4 clutch line 124. This line 124 further leads to the 3-4 clutch 33 via the one-way orifice 78. Therefore, when the second solenoid valve 67 is off in the D and S ranges, the 3-4 clutch 33 is engaged. The accumulator 79 for buffering when the 3-4 clutch 33 is engaged is connected to the branch line 125 of the 3-4 clutch line 124.

A line 126 branches from the 3-4 clutch line 124. The line 126
Guided by the four shift valve 65, the third solenoid valve 6
When 8 is off and the spool of the shift valve 65 is located on the left side, it communicates with the servo release line 127 communicating with the release chamber 38c of the 2-4 brake 35. Therefore, D,
When both the second and third solenoid valves 67 and 68 are off in the S range, pressure oil (servo release pressure) is introduced into the release chamber 38c of the 2-4 brake 35, and the 2-4 brake 35 is released.

In the manual valve 62, the third output line 113 communicating with the main line 110 in the L range includes a low reducing valve 80, a one-way orifice 81, a ball valve 82, and a line 128.
To the 1-2 shift valve 63. The line 128 communicates with a low reverse brake line 129 which communicates with the low reverse brake 36 when the first solenoid valve 66 is off and the spool of the 1-2 shift valve 63 is located on the left side. Therefore, when the first solenoid 66 is off in the L range, the low reverse brake 36 is engaged.

Further, a fourth output line 114 communicating with the main line 110 in the R range is provided with a line 130 branched from the line 114, a one-way orifice 83, the ball valve 82, and a 1-2 shift valve 63 via the line 128. When the first solenoid valve 66 is turned off and the spool of the 1-2 shift valve 63 is located on the left side, it communicates with the low reverse brake line 129. Further, the output line 114 becomes a reverse clutch line 131 and reaches the reverse clutch 34. Therefore, in the R range, the low reverse brake 36 is engaged when the first solenoid valve 66 is off, while the reverse clutch 34 is always engaged. A line 132 branched from the line 130 between the one-way orifice 83 and the ball valve 82 is connected to a buffer accumulator 84 when the reverse clutch is engaged.

As shown in FIG. 6, the hydraulic control circuit 60 includes a lock-up shift valve 85 for operating the lock-up clutch 17 in the torque converter 3 and a lock-up shift valve 85 via the lock-up shift valve 85. A lock-up control valve 86 for adjusting the hydraulic pressure supplied to the torque converter 3 is provided. A pilot line 133 that guides hydraulic pressure (pilot pressure) from a solenoid reducing valve 87 (see FIG. 3) that reduces the hydraulic pressure of the main line 110 to a constant pressure is connected to a pilot chamber 86a at one end of the lock-up control valve 86. The pilot line 133 is provided with a first duty solenoid valve 88 near the lock-up control valve 86.

The lock-up shift valve 85 includes:
A torque converter line 134 led from the regulator valve 61 via a converter relief valve 89 (see FIG. 3) is connected, and a pilot chamber 85 a at one end of the shift valve 85 is connected to a line 11.
5, a pilot line 135 is connected to the main line 110, and the pilot line 135 is provided with a solenoid valve 90 for lock-up. When the solenoid valve 90 is turned off, the spool of the lock-up shift valve 85 is located on the left side, so that the torque converter line 134 is connected to the lock-up release line 1 communicating with the inside of the torque converter 3.
36, whereby the lock-up clutch 17 is completely released.

On the other hand, when the solenoid valve 90 is turned on and the spool of the lock-up shift valve 85 moves to the right, the torque converter line 134 communicates with the converter in-line 137 and the lock-up release line 136 It communicates with the lock-up control valve 86 via 138. The pilot pressure introduced into the pilot chamber 86a of the lock-up control valve 86 from the pilot line 133 is adjusted by the first duty solenoid 88, whereby the converter inline 1
The differential pressure between the engagement pressure introduced via the lock-up release line 136 and the engagement pressure introduced via the lock-up release line 136 is controlled, and the lock-up clutch 17 is controlled to a fully engaged state or a predetermined slip state.

Further, as shown in FIG. 3, the hydraulic control circuit 60 has a throttle module for generating a throttle modulator pressure corresponding to the engine load by operating a second duty solenoid valve 91 for controlling line pressure. A throttle modulator 92 is provided, and the throttle modulator pressure generated by the throttle modulator valve 92 is supplied to the regulator valve 61 through a line 139, and the above-described pressure is supplied through a line 140 branched from the line 139. It is introduced into a pilot chamber 76a provided at one end (left end in the figure) of the spool in the course reducing valve 76 (see FIG. 5). A hydraulic pressure (coast clutch pressure) downstream of the coast clutch line 123 on the coast clutch line 123 is fed back to a pilot chamber 76b provided at the other end (right end in the figure) of the spool in the coast reducing valve 76. Further, a line 141 connected to an intermediate portion of the course reducing valve 76 is led to the 2-3 shift valve 64, and the second solenoid valve 67 is turned on and the spool of the shift valve 64 is located on the right side. When the line 141 is the line 1 leading to the main line 110
In communication with the throttle pressure, the main pressure acts together with the throttle modulator pressure to urge the spool to the right in the drawing. As a result, when the second solenoid valve 67 is on, the coast clutch pressure is increased, and the shared torque of the coast clutch 32 increases. On the other hand, when the second solenoid valve 67 is off,
The spool of the -3 shift valve 64 moves to the left, and communication between the lines 141 and 142 is cut off. Thus, the increased state of the coast clutch pressure is suppressed, and the shared torque of the coast clutch 32 is reduced. It should be noted that the throttle modulator pressure is regulated by the regulator valve 61.
Is connected to a buffer accumulator 93 when the hydraulic pressure is supplied.

In addition to the above configuration, as shown in FIGS. 3 and 4, the hydraulic control circuit 60 has a bypass valve 94 and a 3-2 timing valve 95 for adjusting the supply and discharge timing of the hydraulic pressure during shifting. Are provided. The bypass valve 94 is provided on a bypass line 143 that bypasses the one-way orifice 78 on the 3-4 clutch line 124, and a pilot chamber provided at one end (right end in the drawing) of a spool of the bypass valve 94. A hydraulic pressure (3-4 clutch pressure) downstream of the one-way orifice 78 of the 3-4 clutch line 124 is introduced to 94a. A pilot chamber 94b provided at the other end (left end in the figure) of the spool in the bypass valve 94 has a throttle 144 generated by the throttle modulator valve 92 via a line 144 branched from the line 140. Modulator pressure has been introduced. When the 3-4 clutch pressure rises above a predetermined pressure and the spool moves to the left, the bypass line 143 is shut off. Accordingly, the 3-4 clutch pressure is promptly supplied through the bypass line 143 at the start of the supply, and thereafter, the supply is moderated by the one-way orifice 78. As described above, the engagement timing of the 3-4 clutch 33 during the 2-3 shift-up shift is adjusted, and the timing is changed according to the throttle opening of the engine.

The 3-2 timing valve 95
Are installed on a bypass line 145 that bypasses the one-way orifice 73 and the exhaust pressure control valve 74 on the servo apply line 121 led from the 1-2 shift valve 63. This timing valve 95
A pilot line 146 branched from the main line 110 is connected to a pilot chamber 95a at one end (the right end in the figure), and a solenoid valve 96 for bypass control is connected to the pilot line 146. When the solenoid valve 96 is turned on and the spool of the timing valve 95 is located on the right side,
While the hydraulic oil is quickly supplied to the engagement chamber 38b of the 2-4 brake 35 through the bypass line 145, when the solenoid valve 96 is turned off and the spool of the timing valve 95 is located on the left side, the bypass line 1
45 is shut off, and the hydraulic oil is gently supplied to the engagement chamber 38b of the 2-4 brake 35 by the one-way orifice 73. The timing valve 95
The pilot pressure guided to the pilot chamber 95a is also introduced into the pilot chamber 80a at one end of the low reducing valve 80 (see FIG. 6) via the pilot line 147. Therefore, when the solenoid valve 96 is turned on, the third output line 113 is cut off by the low reducing valve 80 and the low reverse brake 36 is turned off.
Will be delayed.

On the other hand, in the 2-3 shift valve 64,
A drain port 64c communicating with the 3-4 clutch line 124 when the spool is located on the right side is provided, and a first drain line 148 is connected to the drain port 64c. Further, a second drain line 149 (see FIG. 3) is branched from the first drain line 148. The second drain line 149 is guided to the timing valve 95 and a spool of the timing valve 95 is connected to the second drain line 149. When located on the right side, the second drain line 149 communicates with a drain port 95b provided in the timing valve 95. Therefore, when the second solenoid valve 67 is on and the 2-3 shift valve 64 is located on the right side, the 3-4 clutch 3
A 3-4 clutch line 124 leading to 3 communicates with the first drain line 148. Thus, the 3-4 clutch pressure is relatively slowly discharged from the first drain line 148. On the other hand, in this state, when the bypass control solenoid valve 96 is turned on and the spool of the timing valve 95 is moved to the right, the first drain line 148 is connected to the drain port 95b of the timing valve 95 via the second drain line 149. As a result, the 3-4 clutch pressure is quickly discharged from both the first and second drain lines 148 and 149.

Here, as shown in FIG. 7, all the solenoid valves of the hydraulic control circuit 60, that is, the first to third solenoid valves 66 to 68 for shifting, the solenoid valve 90 for lock-up, the solenoid for bypass control, Valve 96 and first and second duty solenoid valves 8
8, 91 are a controller 200 as a shift control means.
The operation is controlled by this. The controller 200 includes a signal from a vehicle speed sensor 201 for detecting a vehicle speed of an automobile equipped with the automatic transmission AT, and a throttle opening sensor 2 for detecting an engine throttle opening.
02, a signal from a shift position sensor 203 that detects the position (range) of a shift lever (not shown) provided in the automatic transmission AT, and a turbine that detects the turbine speed of the torque converter 3. Speed sensor 2
04, the signal from the oil temperature sensor 205 that detects the temperature of the hydraulic oil, and ON when the accelerator pedal is depressed.
A signal from the accelerator switch 206 that operates is input. And the above control 2
00 is an on / off control of each of the solenoid valves 66 to 68 for shifting, based on a map preset according to the vehicle speed of the automobile and the throttle opening of the engine for each range selected by the shift lever. I do. As a result, the positions of the spools of the shift valves 63 to 65 are switched, and the frictional engagement elements 31 to 36 are engaged in the combinations shown in Table 1, and the shift speed is switched according to the operation state. In this case, the relationship between each range or shift speed and the combination pattern of ON / OFF of each of the solenoid valves 66 to 68 for shifting is set as shown in Table 2.

[0054]

[Table 2]

Next, the supply path of the hydraulic pressure in the hydraulic control circuit 60 in each of the travel ranges (R, D, S, L ranges) or the shift speeds will be described with reference to Table 2.

(1) In the case of the R range, the manual valve 62 assumes the R range position, the first and second solenoid valves 66 and 67 are turned off, and the third solenoid valve 6 is turned off.
8 is turned on.

In this case, the fourth output line 114 communicates with the main line 110 to supply a hydraulic pressure (line pressure) to the output line 114, and this hydraulic pressure is supplied to the reverse clutch 34 via the reverse clutch line 131. The reverse clutch 34 is engaged. Further, the hydraulic pressure in the fourth output line 114 is sequentially changed to the 3-4 shift valve 65.
, The ball valve 82, the line 128, the 1-2 shift valve 64, and the low reverse brake line 129 are supplied to the low reverse brake 36, and the low reverse brake 36 is engaged. The other friction fastening elements are released because no hydraulic pressure is supplied.

(2) In the case of D range 1st speed, the manual valve 62 takes the D range position (FIG. 4 shows this state), and the first and second output lines 111 and 112 communicate with the main line 110. The two output lines 111 and 112
Is supplied with hydraulic pressure. In addition, this is the following D range 2-4
The same applies to speed. Then, the first solenoid valve 66
Are turned off, and the second and third solenoid valves 67, 68
Is turned on.

In this case, the hydraulic pressure in the first output line 111 is supplied to the forward clutch 31 via the forward clutch line 119, and the forward clutch 31 is engaged. Further, since no hydraulic pressure is output from any of the shift valves 63 to 65, the other frictional engagement elements are released.

(3) In the case of D range 2nd speed, first to third
All the solenoid valves 66 to 66 are turned on.

In this case, the forward clutch 31 is engaged as in the case of the D range first speed. Further, the hydraulic pressure in the first output line 111 is changed in the order of the 1-2 shift valve 6
3 and the servo apply line 121 to the apply port 35b of the 2-4 brake 35. At this time, no hydraulic pressure is supplied to the release chamber 38c.
The brake 35 is engaged. The other friction fastening elements are released because no hydraulic pressure is supplied.

(4) In the third range of the D range, the first solenoid valve 66 is turned on, and the second and third solenoid valves 67 and 68 are turned off.

In this case, as in the case of the second speed in the D range,
The forward clutch 31 is engaged and the engagement chamber 38b
Is supplied with hydraulic pressure. However, as described later, the hydraulic pressure is also supplied to the release chamber 38c, so that the 2-4 brake 35 is released.

Then, the hydraulic pressure in the first output line 111 is sequentially supplied to the coast clutch 32 via the 3-4 shift valve 65 and the coast clutch line 123, and the coast clutch 32 is engaged. Also, the second
The hydraulic pressure in the output line 112 is changed in order through the 2-3 shift valve 64 and the 3-4 clutch line 124.
The power is supplied to the four clutches 33 and the 3-4 clutch 33 is engaged. Further, the oil pressure in the 3-4 clutch line 124 sequentially changes to the line 126 and the 3-4 shift valve 6.
5 and the release chamber 38c of the 2-4 brake 35 via the servo release line 127, and
-4 brake 35 is released. The reverse clutch 34 and the low reverse brake 36 are released because no hydraulic pressure is supplied.

(5) In the case of D range 4th speed, the first and third solenoid valves 66 and 68 are turned on, and the second solenoid valve 67 is turned off.

In this case, as in the case of the second speed in the D range,
Forward clutch 31 and 2-4 brake 35 are engaged. The 3-4 clutch 33 is engaged as in the case of the D range third speed. The other friction fastening elements are released because no hydraulic pressure is supplied.

(6) In the case of the S range first speed, the manual valve 62 takes the S range position, but the supply path of the hydraulic pressure to the friction engagement element is the same as in the case of the D range first speed.

(7) In the case of the S-range second speed, the first and second solenoid valves 66 and 67 are turned on, and the third solenoid valve 68 is turned off.

In this case, as in the case of the D range second speed,
Forward clutch 31 and 2-4 brake 35 are engaged. Further, the coast clutch 32 is engaged as in the case of the D range third speed. The other friction fastening elements are released because no hydraulic pressure is supplied.

(8) In the case of the S range third speed, the D range 3
It is the same as in the case of speed.

(9) In the case of the first speed in the L range, the manual valve 31 takes the L range position, the first and third output lines 111 and 113 communicate with the main line 110, and the hydraulic pressure is applied to both the output lines 111 and 113. Is supplied. First
And the third solenoid valves 66 and 68 are turned off,
The solenoid valve 67 is turned on.

In this case, the forward clutch 31 is engaged as in the case of the D range first speed, and the coast clutch 32 is engaged as in the case of the D range third speed. Further, the hydraulic pressure in the third output line 113 is sequentially supplied to the low reverse brake 36 via the low reducing valve 80, the line 128, the 1-2 shift valve 63, and the low reverse brake line 129, The low reverse brake 36 is engaged. The other friction fastening elements are released because no hydraulic pressure is supplied.

(10) In the case of the second speed in the L range, the manual valve 62 is in the L range position, but the hydraulic pressure supply path to the friction engagement element is the same as that in the second speed in the S range.

The speed change control method according to one embodiment of the present invention employs the D range by the control 200.
Of the shift control in, it is to apply to the switching control of the definitive 2-4 brake 35 when shifting from the third gear shift stage to the first speed gear position. Hereinafter, this shift control method will be described with reference to FIG.
This will be described with reference to FIG. FIG. 8 is a flowchart of the switching control of the first to third solenoid valves 66 to 68 at the time of shifting from the third gear to the first gear, and FIG. 9 is a flowchart showing the switching from the third gear to the first gear through the first gear. Hydraulic actuator 3 of 2-4 brake 35 when shifting to high gear
8, the first to third solenoid valves 66 to 68
And the change of the oil pressure in the chambers 38b and 38c of the 2-4 brake 35 and the like. Note that FIG.
In (b) , the change state of the oil pressure in the engagement chamber 38b of the 2-4 brake 35 is indicated by a broken line B, and the change state of the oil pressure in the release chamber 38c is indicated by a chain line C, and the change state of the oil pressure of the 3-4 clutch 33 is indicated. Are indicated by solid lines A, respectively.

At the third speed, the first solenoid valve 66 is turned on, and the second and third solenoid valves 67 and 67 are turned on.
68 are both turned off, and pressurized oil is supplied to the engagement chamber 38b and the release chamber 38c of the 2-4 brake 35, respectively. At this time, the 2-4 brake 35 is
The piston 38a is in the released state in which the piston 38a has moved toward the fastening chamber 38b due to the urging force (the state shown in FIG. 9A-1).

The shift from the third gear to the first gear is performed according to the flowchart shown in FIG. That is, after starting, first, it is confirmed that the accelerator switch 206 is not ON, that is, it is not a so-called kick down (step S1), and the value becomes 1 at the time of shifting from the third gear to the first gear. When the current value F (t) of the shift flag is 1 and the previous value F (t−Δt) is 0, that is, immediately after the shift command is output, all of the first to third solenoid valves 66 to 68 It is turned on (steps S2 to S4). This state is the second
This is the same as at the time of the shift speed, and the pressure oil is removed from the release chamber 38c while the pressure oil is supplied to the engagement chamber 38b of the 2-4 brake 35. At this time, the piston 3 of the 2-4 brake 35
8a is moved to the release chamber 38c side by receiving the pressing force of the pressure oil in the fastening chamber 38b, and the pressure oil in the release chamber 38c is forcibly removed with this movement (FIG. 9 (a-2)). Status).
This state corresponds to the time (T) corresponding to the initial value TM of the timer.
M / Δt) is continued (steps S5 to S5).
S7).

When the time (TM / Δt) has elapsed, the first solenoid valve 66 is turned off, and both the second and third solenoid valves 67 and 68 are turned on (step S8).
) 2-4 Engagement chamber 38b of brake 35 and release chamber 3
8c respectively excludes pressure oil. At this time, the piston 38a of the 2-4 brake 35 moves from the release chamber 38c side to the fastening chamber 38b side by the urging force of the spring 38d, and with this movement, the pressure oil in the fastening chamber 38b is forcibly removed ( FIG. 9 (a-3) state). In addition, the state where almost no oil remains in the release chamber 38c remains.

When shifting from the first gear to the second gear in such a state, pressure oil is supplied only to the engagement chamber 38b of the 2-4 brake 35, and the piston 38a moves toward the release chamber 38c. It moves and becomes a fastening state. At this time, since almost no oil remains in the release chamber 38c, the residual pressure hardly occurs in the release chamber 38c due to the movement of the piston 38a. As a result, the movement of the piston 38a and the switching of the 2-4 brake 35 can be performed smoothly, and the occurrence of a shift shock due to a delay in the switching timing can be prevented.

[0079]

As described above, according to the shift control method of the automatic transmission according to the present invention , the shift control in the automatic shift range is performed.
Of the initial pressure oil is supplied to the release chamber of the friction engagement elements
Both the gear apply chamber and the release chamber in which pressure oil is eliminated
The purpose of supplying pressurized oil only to the fastening chamber through the intermediate gear
When shifting to the previous gear , change from the initial gear to an intermediate gear.
When shifting to a higher gear, the gear is shifted through a state in which pressure oil is supplied to the engagement chamber and pressure oil in the release chamber is positively removed . It is possible to prevent the generation of residual pressure in the release chamber when shifting from the intermediate speed to the target speed in which pressure oil is supplied only to the engagement chamber, and reduce shift shock. Can be achieved.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of an automatic transmission according to an embodiment of the present invention.

FIG. 2 is a hydraulic circuit diagram showing the vicinity of a transmission main body in a hydraulic control circuit of the automatic transmission.

FIG. 3 is a hydraulic circuit diagram showing the vicinity of a regulator valve.

FIG. 4 is a hydraulic circuit diagram showing the vicinity of a manual valve.

FIG. 5 is a hydraulic circuit diagram showing the vicinity of a 3-4 shift valve.

FIG. 6 is a hydraulic circuit diagram showing the vicinity of a lock-up shift valve.

FIG. 7 is a block diagram of a solenoid valve control system.

FIG. 8 is a flowchart of switching control of the first to third solenoid valves at the time of shifting from the third speed to the first speed.

FIG. 9 shows the operation state of the hydraulic actuator of the 2-4 brake and the ON-OFF state of the first to third solenoid valves when shifting from the third gear to the second gear through the first gear.
It is a figure which shows the change state of the hydraulic pressure of each room etc. of switching and said 2-4 brake.

FIG. 10 is a diagram corresponding to FIG. 9 showing a conventional example. However, the first
The change state of ON-OFF switching of the third solenoid valve is omitted.

[Explanation of symbols]

 35 2-4 Brake (friction fastening element) 38a Piston 38b Fastening chamber 38c Release chamber

Continuation of the front page (72) Inventor Hiroshi Shinozuka 3-1 Shinchi, Fuchu-cho, Aki-gun, Hiroshima Mazda Corporation (72) Inventor Bunsaku 3-1, Shinchi-fuchu-cho, Aki-gun, Hiroshima Mazda Corporation (72) Inventor Kenji Okamoto 3-1 Shinchi, Fuchu-cho, Aki-gun, Hiroshima Prefecture Inside Mazda Co., Ltd. (56) References JP-A-62-83543 (JP, A) Jika-sho 62-114250 (JP, U) (58) Field surveyed (Int. Cl. ⁷ , DB name) F16H 61/00-61/24

Claims (1)

(57) [Claims] 1. A friction fastening element having a fastening chamber and a release chamber provided before and after a piston, wherein the friction fastening element is engaged when pressure oil is supplied only to the fastening chamber. In the automatic transmission configured to release the engagement when the pressure oil is supplied to both of the release chambers or when the pressure oil is removed from both of the chambers , the above-described friction engagement is included in the shift control in the automatic shift range. from the initial shift stage pressure oil to the release chamber of the element is supplied, via an intermediate gear which pressure oil is eliminated the two chambers both fastening
When pressure oil only the chamber is shifted to the object of the gear stage to be supplied
When shifting from the initial gear to the intermediate gear
, The shift control method of an automatic transmission, characterized by shifting through a state to actively eliminate the pressure oil in the release chamber by supplying pressure oil to the apply chamber.