JPH0658148B2 - Automatic transmission control device - Google Patents

Description

TECHNICAL FIELD The present invention relates to a control device for an automatic transmission.

(Prior Art and Problems Thereof) An automatic transmission has a plurality of friction members for selecting a shift speed therein, and a predetermined shift speed is controlled by appropriately controlling the operation of each speed-selection friction member. You can get a step. Among such automatic transmissions, there are some automatic transmissions in which a plurality of gear selection friction members are reversely operated at the same time to perform downshifting. For example, when shifting from the 4th speed or the 3rd speed to the 2nd speed in the D (drive) range (1st speed 4th speed), the front clutch is engaged and the second brake is released in the 4th speed or the 3rd speed. By releasing the front clutch and engaging the second brake, the gear shifts down to second gear. Here, in such a hydraulic control system for the front clutch and the second brake,
Generally, a common hydraulic pressure supply system and hydraulic pressure release system are used, and the hydraulic pressure for engaging the front clutch is used as the releasing hydraulic pressure for releasing the engagement of the second brake, and the drain passage for releasing the front clutch is released. , It is used as a drain passage for releasing the release hydraulic pressure for engaging the second brake.

As described above, in the automatic transmission in which the shift-down control is performed, a shift shock may occur unless the operation timings of the plurality of gear selection friction members are appropriate. The reason for this will be described by taking downshifting from the fourth speed or the third speed to the second speed in the D range as an example.

That is, in this case, is the turbine speed of the torque converter Figure 3 with the release of the front clutch rotational speed of the fourth speed as shown in (A) N ₄ or the third speed when the rotational speed N ₃ of
To the number of revolutions N ₂ from the 2nd speed to the 2nd speed at the 4th speed or the 3rd speed
It increases by the number of rotations corresponding to the gear ratio with high speed. Therefore, after the front clutch is disengaged, if the engagement of the second brake is completed at the time when the turbine speed reaches the rotation speed N ₂ at the 2nd speed, a smooth gear shift is performed as shown in the rotation speed characteristic shown in FIG. 3 (A). As a result, shift shock is reduced. However, the change amount (increase amount) of the turbine rotation speed is Δ in the case of downshifting from the fourth speed to the second speed.
N ₁ , which is larger than ΔN _{2 in} the case of shifting from the third speed to the second speed. Therefore, the time from when the front clutch is released to when the turbine speed reaches N ₂ is different. Therefore, if the engagement timing of the second brake is kept constant, suitable shift control becomes impossible. For example, if the engagement timing of the second brake is too early, a double lock state occurs in which both the front clutch and the second brake are engaged simultaneously, and as shown in FIG. Rotational speed N
It will be more depressed than ₃ . On the contrary, when the engagement timing of the second brake is too late, both the front clutch and the second brake are temporarily released to be in the free state, and as shown in FIG. The rotational speed further rises above the rotational speed N ₂ and a so-called blank blowing phenomenon occurs.
Such a drop or excessive increase in the turbine speed during gear shifting causes a gear shift shock.

Therefore, for example, an oil passage having a throttle element as disclosed in Japanese Unexamined Patent Publication No. 56-156543 is used as a drain passage for eliminating the release pressure of the second brake to control the speed at which the release pressure escapes. It is possible to adjust the operation timing between the front clutch and the second brake by this. However, in this case, a large number of oil passages having different throttle amounts are required, or a mechanism for appropriately controlling the throttle amount is required, which makes the structure of the hydraulic circuit complicated, which is not preferable. Moreover,
Since the passage for releasing the hydraulic pressure is shared, the passage for releasing the hydraulic pressure is also shared, so that the time required for releasing the hydraulic pressure varies, and therefore, a shift shock may occur.

SUMMARY OF THE INVENTION The present invention is intended to solve the above-mentioned problems, and can prevent a shift shock due to an inadequate operation timing of a friction member for selecting a low speed stage and a friction member for selecting a high speed stage during shifting. It is an object of the present invention to provide a control device for the automatic transmission.

(Means for Solving the Problems) Therefore, in the device of the present invention, the hydraulic pressure applied to the actuator for holding the friction member for selecting the low speed stage in the released state is changed to the engagement state of the friction member. The friction member for releasing the friction member is selected after the friction member for selecting the high speed stage is changed from the engaged state to the released state. Also, it is performed after the elapse of a predetermined time determined according to the type of the shift stage on the high speed stage side.

That is, in the device of the present invention, as shown in FIG. 1, the input member of the torque converter b is connected to the output shaft a of the engine, and the output member of the torque converter has a plurality of gear shift stages. The gear shifting means is connected to the gear c and the gear shifting means switches to a predetermined gear stage among the plurality of gear gears. The gear shifting means actuates the plurality of friction members d and each of these friction members. It has a plurality of hydraulic actuators e and a plurality of valve means g for controlling the supply of the hydraulic pressure from the hydraulic pressure source f to each of these hydraulic actuators, and the drive control of the valve means controls the operation of the vehicle. It is designed to be performed by the control circuit h in accordance with a predetermined control means according to the state,
The hydraulic actuator e is a first actuator e-1 that is biased by a hydraulic pressure supplied from a hydraulic source via an oil passage i to fasten a first friction member d-1 for selecting a high speed stage, and There is provided a second actuator e-2 which is biased by the hydraulic pressure supplied from the oil passage i branched from the oil passage i and releases the engagement of the second friction member d-2 for selecting the low speed stage. However, the valve means g has a shift valve g-1 inserted in the oil passage, the shift valve opening the oil passage i in the first position, and the first and second actuators in the second position. The oil passage i on the side and the first hydraulic pressure discharge passage k are communicated with each other, and by engaging the first friction member and releasing the second friction member, the first one of the gear speeds is set. A gear group is selected and the first gear is selected. By releasing the member and engaging the second friction member, the second shift speed lower than any one of the first shift speed group is selected, and the timing valve is provided on the branch path j. g-2 is inserted, the timing valve g-2 opens the branch passage in the first position, and the second actuator e-2 in the second position.
The branch passage j on the side of and the second hydraulic pressure discharge passage 1 communicate with each other, and the control circuit h causes the shift valve g-
After outputting a signal A ₂ for switching 1 to the second position, a signal A ₅ for switching the timing valve g-2 to the second position is output after a predetermined time T, and a signal to the shift valve is output. At the time of output, the shift speed selected from the first shift speed group is set to the output S of the shift speed detecting means m.
It is determined from S, and the time T
The feature is that it is decided.

(Operation) In the device of the present invention configured as described above, when it is determined from the detected driving state of the vehicle that downshifting from the current high speed stage to the low speed stage is necessary, the signal A ₂ (shift down signal) ) Is output to the shift valve g-1. This signal A
_{When 2} comes in, the shift valve g-1 shifts to the second position, and the oil passage i on the first actuator e-1 side communicates with the oil discharge passage k. As a result, the first actuator e-
The hydraulic pressure to 1 disappears, and the first friction member d- for selecting the high speed stage
1 shifts from the engaged state to the released state. First friction member d
When -1 is released, the turbine side of the torque converter is released from the transmission output side, and the turbine speed increases. Here, the control circuit determines the current shift speed from the signal SS from the shift speed detecting means m, and obtains the time T corresponding to the shift speed. After this, a signal A ₅ (timing signal) is output to the timing valve g-2 after a predetermined time T has passed from the release of the first friction member d-1. By this signal, the timing valve g-1 is shifted to the second position, and the branch passage j on the side of the second actuator e-2 communicates with the hydraulic pressure discharge passage l. As a result, the second actuator e
-2 the hydraulic pressure disappears, and the second friction member d for selecting the low speed stage
-2 shifts from the released state to the fastened state. In this way, the transition from the high speed stage to the low speed stage is completed.

(Effects of the Invention) As described above, according to the present invention, after the release of the first friction member for selecting the high speed stage, after the predetermined time T determined according to the type of the high speed stage elapses, the second speed stage is selected. The friction member is fastened, and the hydraulic pressure for fastening the second friction member is directly removed through a dedicated oil discharge passage. Therefore, the engagement time of the second friction member is always determined appropriately regardless of which side of the high speed gear shifts to the low speed gear, and the hydraulic pressure is quickly removed through the dedicated discharge passage. Therefore, the shift to the low speed stage is performed accurately at a suitable time, and thus the shift to the low speed stage is performed without causing a shift shock.

(Embodiment) A preferred embodiment of the present invention will be described below with reference to FIGS.

FIG. 2 shows a power transmission section of an automatic transmission according to an embodiment of the present invention, a hydraulic control circuit for the power transmission section, and a control circuit for controlling each of these sections.

Configuration of Automatic Transmission The automatic transmission includes a torque converter 1, a multistage gear transmission mechanism 2, and an overdrive planetary gear transmission mechanism 3 arranged between the torque converter 1 and the multistage gear transmission 2.
And have.

The torque converter 1 has a pump 5 coupled to the engine output shaft 4, a turbine 6 arranged to face the pump 5, and a stator 13 arranged between the pump 5 and the turbine 6. Further, a converter output shaft 8 is connected to the turbine 6. A lockup clutch 9 is provided between the converter output shaft 8 and the pump 5. The lockup clutch 9 is constantly urged in the fastening direction by the hydraulic oil pressure circulating in the torque converter 1, and is kept in the released state by supplying the releasing pressure oil from the outside into the pressure chamber 9a. To be done.

The multi-stage gear speed change mechanism 2 has a front stage planetary gear mechanism 10 and a rear stage planetary gear mechanism 11, and the sun gear 12 of the front stage planetary gear mechanism 10 and the sun gear 13 of the rear stage planetary gear mechanism 11 are connected by a connecting shaft 14. . The input shaft 15 of the multi-stage gear transmission 2 is connected to the connecting shaft 14 via a front clutch 16 (first friction member for selecting a high-speed stage), and the internal gear 18 of the front planetary gear mechanism 10 via a rear clutch 17. Are connected to each. Connection shaft 1
4, that is, a second brake 19 (a second friction member for selecting a low speed stage) is provided between the sun gears 12 and 13 and the transmission case. The planetary carrier 20 of the front planetary gear mechanism 10 and the internal gear 21 of the rear planetary gear mechanism 11 are connected to the output shaft 22. Also,
A low / reverse brake 24 and a one-way clutch 25 are provided between the planetary carrier 23 of the rear planetary gear mechanism 11 and the transmission case.

This multi-stage gear speed change mechanism 2 has a conventionally known speed change mechanism, has three speed stages of forward movement and one speed of reverse movement, and includes a front clutch 16, a rear clutch 17, a second brake 19, and a low / reverse brake 24. As will be described later, a desired gear can be obtained by appropriately operating the hydraulic actuator.

The planetary gear transmission 3 for overdrive includes a planetary carrier 27 that rotatably supports the planetary gear 26.
And a sun gear 28 joined to the internal gear 30 via the direct clutch 29. An overdrive brake 31 is provided between the sun gear 28 and the transmission case, and the internal gear 30 is connected to the input shaft 15 of the multi-stage gear transmission 2.

In this overdrive planetary gear speed change mechanism 3, the direct clutch 29 is engaged and the overdrive brake 31 is engaged.
Is released, the converter output shaft 8 and the input shaft 15 are directly connected to each other, then the overdrive brake 31 is engaged, and when the direct clutch 29 is released, the converter output shaft 8 and the input shaft 15 are released. It works like an overdrive connection with.

In this transmission, a manual valve 61 of a hydraulic control circuit, which will be described later, is manually selected to appropriately operate the friction members (clutch and brake) of the multi-stage gear transmission 2 and the overdrive planetary gear transmission mechanism 3. By so doing, the required speed is obtained, and the control pattern of each friction member is set as follows for each range as in the conventional structure.

Hydraulic Control Circuit The hydraulic control circuit has a circuit configuration that allows each friction member to be operated in accordance with the operation pattern shown in Table 1 above according to the driver's selection operation to obtain a predetermined shift speed. This will be described in detail below.

In the hydraulic control circuit, reference numeral 50 is a hydraulic pump,
The hydraulic oil discharged from the hydraulic pump 50 is regulated to a predetermined pressure by the pressure regulating valve 62 and introduced into the manual valve 61 via the pressure line 101.

The manual valve 61 has five ports that can communicate with the pressure line 101. That is, a port (a) communicating with the pressure line 101 in the three ranges (D, 2, 1), a port (b) communicating with the pressure line 101 in the two ranges (D, 2), and an R range. Port (c) communicating with the pressure line 101 only at (P,
Pressure line 101 in the four ranges R, 2, 1)
And a port (e) communicating with the pressure line 101 in the two ranges (R, 1).

The port (a) is connected to the line 111. This line 111 has three pilot lines at its line ends, that is, a first pilot line 102 having a 1-2 shift solenoid valve 51 for controlling the operation of the 1-2 shift valve 63 and a throttle 86, and 2-3. 2-3 shift solenoid valve 5 for controlling the operation of shift valve 64
2 and a second pilot line 103 having a diaphragm 87,
A 3-4 shift solenoid valve 53 for controlling the operation of the 3-4 shift valve 65 and a third pilot line 104 provided with a throttle 88 are branched (these shift valves 64 and the solenoid valve 52 are the shift of FIG. 1). Equivalent to valve g-1). The solenoid valves 51, 52, and 53 are turned on (excited) to cause drain lines 105, 106, and 107, respectively.
To close each pilot line 102, 103, 104
Pilot pressure is applied to each of them to move each shift valve 63, 64, 65 from the OFF position (right moving position) to the ON position (left moving position) to open / close the hydraulic circuit of the associated friction element. The operation pattern is set according to each range and gear as shown in Table 2 below.

In this case, the 3-4 shift solenoid valve 53 is
The OFF position is set at the 1st speed and the 2nd speed in the D range, but the ON position is set at each of the 1st speed and the 2nd speed in the 1st range and the 2nd range as shown in parentheses. This is for setting the 3-4 shift solenoid valve in the ON position in the first range and the second range so that the backup control valve 70, which will be described later, is loaded with the pilot pressure.

The first pilot line 102 communicates with the right end portion (pilot pressure load portion) of the 1-2 shift valve 63 on the downstream side of the 1-2 shift solenoid valve 51.
The second branch line 10 communicating with the branch line 102a and the right end portion (pilot pressure load portion) of the cutback valve 66.
It is branched into two lines 2b.

Line pressure is applied to both ends of the 1-2 shift valve 63 through a line 112 branched from the line 111 and a line 113 branched further from the line 112, and 1-2.
In the middle of the shift valve 63, the manual valve 61
The line pressure is introduced via the line 122 communicating with the port (e). The line 122 is connected to the line 123 when the shift valve 63 is at the OFF position, that is, when the shift position is at the first speed position. Also, this line 123
Is connected to the low / reverse brake actuator 44. On the other hand, the line 113 is 1-2
When the shift valve 63 is in the ON position, that is, when the shift position is a shift position other than the first speed, the line 161 is connected. This line 161 is used for the second brake actuator 45 (the second actuator e in FIG. 1).
(Corresponding to -2) is connected to the fastening side 45A.
Further, the reducing valve 68 is connected to the line 161.
An accumulator 79 and a one-way orifice 82 whose back pressure is controlled by are provided.

The 2-3 shift valve 64 is turned on by the pilot pressure introduced from the line 103 connected to the right end of the 2-3 shift valve 64.
It is designed to be turned off. This 2-3 shift valve 64 has a port of the manual valve 61.
A line 121 communicating with (b) and a line 131 communicating with port (c) are connected to each other.

Of this line 121 and line 131, line 121
Indicates the line 132 at the ON position of the 2-3 shift valve 64 (that is, the shift position of the third speed or the fourth speed), and the line 131 indicates the OFF position of the 2-3 shift valve 64 (that is, the shift position).
In the 1st speed or the 2nd speed), the lines 132 are selectively communicated with each other. (Lines 121 and 132 correspond to the passage i in FIG. 1, and line 131 also corresponds to the passage k.) The line 131
A reducing valve 67 and a one-way orifice 85 are connected in parallel with each other.

On the downstream side of the line 132, a line 136 (corresponding to the passage i in FIG. 1) connected to the front clutch actuator 41 (corresponding to the first actuator e-1 in FIG. 1) and the second brake are connected. Release side 4 of actuator 45 (second actuator e-2)
5B to a line 138 (corresponding to the branch path j in FIG. 1). A one-way orifice 74 that acts so as to squeeze the operating oil from the 2-3 shift valve 64 (corresponding to the shift valve g-1 in FIG. 1) toward the branch portion is installed upstream of the branch portion of the line 132. Has been. Further, at a position immediately downstream of the branch portion of the line 138 (branch path j), from the second brake actuator 45 (second actuator e-2) side, 2-
A check valve 75 that blocks the flow of hydraulic oil in the direction toward the 3rd shift valve 64 (shift valve g-1) is attached. Further, a line 137 having a 3-2 timing valve 73 (timing valve g-2) is connected to a position downstream of the check valve 75 on the line 138 (branch path j).

This 3-2 timing valve 73 (timing valve g
-2) is one in which the spool is displaced to the right end by the pilot pressure applied to the left end thereof and the line 137 communicates with the drain passage 137 '(corresponding to the discharge passage 1 in FIG. 1). The pilot pressure load section is line 16
3 is connected to the line 112. A diaphragm 72 is provided at the connecting portion between the line 163 and the line 112, and a drain line 117 provided on the line 163 side of the diaphragm 72 is provided with a timing adjusting solenoid valve 47, and the solenoid valve 47.
A predetermined pilot pressure is generated in the line 163 by the ON operation of. A one-way orifice 83 is provided further downstream of the branch portion of the lines 137 and 138 of the line 138.

Further, an accumulator 78, whose back pressure is controlled by a line pressure supplied from a line 139 branched from the line 132, acts on the line 136 so as to squeeze the operating oil flowing out from the accumulator 78. It is connected through the orifice 81. The back pressure control of the accumulation layer 78 is performed by the reducing valve 67.

The third pilot line 104 is on the downstream side of the 3-4 shift solenoid valve 53 and communicates with the right end portion of the 3-4 shift valve 65.
Is branched into two branch lines of a second branch line 104b that guides the pilot pressure to the backup control valve 70 described later.

A line 141 branched from the pressure line 101 is connected to an intermediate portion of the 3-4 shift valve 65. This line 141 is the line 142 at the OFF position of the 3-4 shift valve 65 (that is, the shift position other than the 4th speed).
Be able to communicate with. This line 142 is branched on its downstream side into two lines, a line 143 communicating with the direct clutch actuator 42 and a line 144 communicating with the release side 46B of the overdrive brake 46, and upstream of the branching portion. A hydraulic switch 90 is attached to the side position. Further, the line 143 is provided with an accumulator 77. The fastening side 46A of the overdrive brake 46 is connected to the line 148.
Is communicated with the pressure line 101 via the.

On the other hand, a line 151 communicating with the port (d) of the manual valve 61 is provided at the left end of the 3-4 shift valve 65.
Is connected, and the spool of the 3-4 shift valve 65 is forced to be O by the line pressure introduced through the line 151 at the select position other than the D range.
Positioned and held in the FF position. A line 152 branching from the line 151 and communicating with the vacuum throttle valve 69 has a throttle backup valve 71 and a backup control valve 70.
And the backup control valve 7 in series
It is mounted such that 0 is located downstream of the throttle backup valve 71. The stottle backup valve 71 causes the line pressure standing on the line 152 in the 2nd range and the 1st range to act on the vacuum throttle valve 69, and drives the pressure adjusting valve 62 in the pressure increasing direction via the vacuum throttle valve 69. It acts to increase the pressure. The backup control valve 70 includes a throttle backup valve 71 and a vacuum throttle valve 6 described above.
9 and the pilot pressure rises in the branch line 104b, that is, the 3-4 shift solenoid valve 5
When the valve 3 is turned on, the line 152 is opened, and the throttle backup valve 71 operates to increase the line pressure.

The line 112 is connected to a line 116 communicating with the rear clutch actuator 43 on the upstream side of the throttle 72. The line 116 is provided with an accumulator 80 and a one-way orifice 84. Further, a reducing valve 68 for adjusting the back pressure of the accumulator 79 is provided on a line 114 branched from the line 112.

Further, the line 149 is connected to the working chamber 9a of the lockup clutch 9 through a line 146 provided with a lockup valve 76 and a throttle 91 on the way. Pilot line 1 of this lockup valve 76
45 is a throttle 89 and a lockup solenoid valve 54
The lock-up clutch 9 is released when the lock-up solenoid valve 54 is turned on to generate pilot pressure in the line 145 and the spool connects the line 146 and the line 149. Has become. In this embodiment, the lockup clutch 9 is engaged only between the first speed and the third speed in the D range.

Control Circuit Control Circuit 2 for Controlling the Operation of the Hydraulic Control Circuit
00 can be composed of, for example, a one-chip microcomputer, and includes an input / output unit, a random access memory RAM,
Read-only memory ROM, central processing unit CP
Have U. Various signals indicating the operating state of the engine are input to the control circuit 200 from sensors arranged in various parts of the engine. For example, a load signal SL is supplied from a load sensor that detects the engine load from the opening degree of a throttle valve provided in the intake passage of the engine, and a turbine speed signal is supplied from a turbine speed sensor arranged on the torque converter output shaft. ST is supplied. The CPU detects the operating state of the engine from these supplied signals, determines the shift stage according to a predetermined control means based on the detected driving state, and drives each solenoid valve to reach this shift stage. Output a signal. That is,
Three shift solenoid valves 51, 5 of the hydraulic control circuit
2, 53, the lockup solenoid valve 54, and the timing adjustment solenoid valve 47 are output from the control circuit based on various engine state detection elements such as the load signal (throttle opening signal) SL and the turbine speed signal ST. ON / OFF control is performed in accordance with the control patterns shown in Table 2 by the control signals A ₁ , A ₃ , A ₃ , A ₄ , and A ₅ , respectively.
As a result, each friction member operates according to the operation pattern shown in Table 1, and a predetermined gear speed is obtained.

Further, in this example, the drive signal to each solenoid valve is fed back, and the current gear position is detected from these signal states. When the gear positions detected in this way are the 4th speed and the 3rd speed, the time T from the output of the signal A ₂ to the output of the signal A ₅ at the time of downshifting from these shift positions to the 2nd speed. Are different values. That is, as shown in FIG.
In the case of shifting from the second speed to the second speed, the increase in the turbine speed is large, so the time T is a large value T ₁ , and in the case of the third speed to the second speed, the time T is a value T ₂ smaller than T _1. I am trying. The second brake at the time of downshifting from the 4th speed and the 3rd speed to the 2nd speed in the D range by the control signal A ₅ output from the control circuit to the solenoid valve 47 after the elapse of the times T ₁ and T ₂ thus set. The engagement timing of 19 is adjusted so that the shift shock caused by the improper engagement timing is prevented.

Operation Hereinafter, the operation of the hydraulic control circuit and its operation will be described by taking downshifting from the third speed running state to the second speed running in the D range as an example.

(3rd speed running) In this case, the port (a) and the port (b) of the manual valve 61 are in communication with the pressure line 101, and one of the three shift solenoid valves 51, 52, 53 is
Both the -2 shift solenoid valve 51 and the 2-3 shift solenoid valve 52 are in the ON position, and the 3-4 shift solenoid valve 53 is in the OFF position. For this reason,
In the 1-2 shift valve 63, the line 113 and the line 161 communicate with each other, the line pressure is applied to the engagement side 45A of the second brake actuator 45 (second actuator e-2), and the 2-3 shift valve 64 (shift). Line 121 and line 13 in valve g-1)
2 (passage i) communicates with each other, and the front clutch actuator 41 (first actuator e-1) and the second brake actuator 45 (second actuator e-) are connected.
Line pressure is applied to each of the release sides 45B in 2). Therefore, the front clutch 16 (the first friction member d-
1) is engaged and the second brake 19 (second friction member d
-2) is released.

On the other hand, since the line 123 is drained, the low / reverse brake 24 is released. That is, the engine brake is not in operation.

Further, in the 3-4 shift valve 65, the line 141
And the line 142 communicate with each other. Therefore, the direct clutch 29 is engaged. On the other hand, in the overdrive brake 46, the line pressure is introduced to the release side 46B via the pressure line 142, and thus the overdrive brake 31 is in the released state.

Further, line pressure is introduced to the line 112,
Therefore, the rear clutch 17 is in the engaged state. By operating each friction member in this manner, the third speed running in the D range is realized.

On the other hand, in this state, since the line 151 is drained, the 3-4 shift solenoid valve 53 is turned on.
The throttle pressure does not act on the vacuum throttle valve 69 even if the backup control valve 70 is set to the ON position by operating and generating pilot pressure in the branch line 104b.

(When Downshifting to 2nd Speed) When shifting down to 2nd speed, the 1-2 shift solenoid valve 51 remains in the ON position and the 3-4 shift solenoid valve 53 remains in the OFF position. However, the signal A ₂ from the control circuit 200 is turned on and 2
The -3 shift solenoid valve 52 is switched from the ON position (first position) to the OFF position (second position).

Therefore, in the 1-2 shift valve 63, the line 123 and the line 161 communicate with each other, the line 123 is drained, and the low / reverse brake 24 remains released. However, in the 2-3 shift valve 64 (shift valve g-1), the line 132 is the line 13
Because it communicates with 1, it is drained. Therefore, the engagement pressure of the front clutch 16 (first friction member d-1) is released,
The clutch 16 is released. Further, the second brake 19 (second friction member d-2) is still in the released state. As a result, the turbine speed of the torque converter is increased by releasing the front clutch, as shown in FIG.
The rise starts as indicated by the solid line.

After this, as indicated by the solid line in FIG. 3C, the signal A ₅ is turned on after a lapse of a predetermined time T from the turning on of the signal A ₂ . As a result, the solenoid valve 47 is energized, and 3-
2 Timing valve 73 (timing valve g in FIG. 1
-2) Hydraulic oil is added, and this valve 73 is line 137.
And the drain passage 137 '(the discharge passage 1 in FIG. 1). Therefore, the release pressure of the second brake 19 is quickly released through the line 137, the valve 73, and the drain passage 137 '. Thus, as shown in FIG. 3, a predetermined time from the ON signal A _5, i.e. after the release pressure has passed completely exit time [Delta] T, the second brake 19 are engaged. When this fastening state is formed, the signal A ₅ is turned off again.

Here, the release pressure from the release side 45B of the actuator 45 is quickly removed through the drain passage 137 ', and the time Δ required until the release pressure is completely released.
The fluctuation of T is extremely small. Also, the front clutch 16
The time T ₂ is set such that the engagement of the second brake 19 is completed at the time when the turbine speed increases from N ₃ to N ₂ after the release. Therefore, according to this example, such downshift can be performed without any shift shock. On the other hand, at the time of downshifting, the direct clutch 29 and the rear clutch 17 are brought into the engagement state by introducing the engagement pressure. By operating each friction member in this manner, the second speed running is realized.

Next, during the downshift control from the 4th speed to the 2nd speed,
As indicated by the broken line in FIG. 6C, the signal A ₅ turns ON after the elapse of the time T ₁ . Therefore, also in this case, according to the present example, it is possible to obtain an ideal curve as shown by the broken line in FIG.

Next, FIG. 4 shows each solenoid valve 47, 5 of this embodiment.
A valve structure suitable for use as 1 to 54 is shown. As shown, in this preferred structure, a valve housing 302 having a valve spool 301 slidably incorporated therein is provided.
A coil 303, which is a solenoid part, and a movable iron core 304 are integrally incorporated therein. That is, the movable iron core 304 is coaxially attached to the axial end of the valve housing 302.
Are arranged, the coils 303 are arranged coaxially around the outer periphery of the iron core 304, and these are housed in a portion 302 ′ where the end portion of the valve housing 302 extends. With such a valve structure, the solenoid valve itself can be downsized as compared with the conventional case where a separate solenoid part is attached using a valve housing bolt, etc. As a result, the circuit design becomes easy. Further, there is an advantage that the manufacturing cost can be greatly reduced.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing the configuration of the present invention, FIG. 2 is an overall configuration diagram showing an embodiment of the present invention, and FIG. 3 (A) is a characteristic diagram showing a change with time of turbine rotational speed. (B) and (C) are waveform diagrams of signals A ₂ and A ₅ , respectively, FIG. 4 is a partial sectional view showing a preferred structure of the solenoid valve, and FIGS. 5 and 6 are turbine rotational speeds with time. It is a characteristic diagram which shows change. a ... Engine output shaft, b ... Torque converter, c ... Multi-stage gear speed change mechanism, d ... Friction member, d-1 ... First friction member, d-2 ... Second friction member, e ... Hydraulic actuator, e-1 ... First actuator, e-2 ... Second actuator, f ... Hydraulic source, g ... Valve means, g-1 ... Shift valve, g-2 ... Timing valve, h ...... control circuit, i ...... oil passage, j ...... branch passage, k ...... first hydraulic pressure exhaust line, l ...... second hydraulic pressure exhaust line, m ...... gear position detecting _{means, A 2,} A ₅ ... …signal.

Claims (1)

[Claims] 1. An input member of a torque converter is connected to an output shaft of an engine, an output member of the torque converter is connected to a multi-stage gear speed change mechanism having a plurality of gear speed stages, and one of the plurality of gear speed stages is connected. The shift to a predetermined shift stage is performed by a shift switching means, and the shift switching means includes a plurality of friction members, a plurality of hydraulic actuators for operating each of these friction members, and each of these hydraulic actuators. On the other hand, it has a plurality of valve means for controlling the supply of the hydraulic pressure from the hydraulic power source, and the drive control of the valve means is performed by the control circuit according to a predetermined control procedure according to the operating state of the vehicle. The hydraulic actuator is energized by the hydraulic pressure supplied from the hydraulic source through the oil passage, and is the first speed selection first speed stage.
A second actuator that fastens the friction member and a second friction member that is biased by a hydraulic pressure supplied through a branch passage branched from the oil passage to release the second friction member for selecting a low speed stage. Of the actuator, the valve means has a shift valve inserted in the oil passage, the shift valve opens the oil passage at a first position, and the shift valve opens at the second position on the first and second actuator sides. Of the gear shift stage among the gear shift stages by engaging the first friction member and releasing the second friction member. Is selected, and the second shift speed lower than any one of the first shift speed group is selected by releasing the first friction member and engaging the second friction member. , Timing in the branch A valve is inserted, the timing valve opens the branch passage in the first position, and
At the position, the branch passage on the side of the second actuator and the second hydraulic pressure discharge passage are communicated with each other, and the control circuit outputs a signal for switching the shift valve to the second position for a predetermined time. After that, a signal for switching the timing valve to the second position is output, and at the time of outputting the signal to the shift valve, according to the kind of the selected speed stage in the first speed stage group,
An automatic transmission control device, characterized in that the predetermined time is changed.