JPH06346964A - Speed change controller of automatic transmission - Google Patents

Abstract

PURPOSE:To secure achievement of a reverse stage and also to prevent judder in achievement of the reverse stage. CONSTITUTION:A sub speed change part and a main speed change part capable of achieving a plurality of respective speed change stages are connected to each other in series, so as to place the specific frictional engaging device B0 of the sub speed change part in engagement. And the specific frictional engaging devices B4, C2 in the main speed change part are engaged with each other by supplying oil pressure to the specific frictional engaging device B4 from a first valve 76 to be controlled by a solenoid valve S4 through a first shift valve 84. Thereby the reverse stage is achieved in a speed change controller of an automatic transmission. Oil passages 95, 97 for supplying oil pressure to the specific frictional engaging device B4 in the main speed change part are provided by bypassing the first shift valve 84. Even there is a failure of the first shift valve, the supply of oil pressure to the frictional engaging device B4 is secured, so as to achieve the reverse stage.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a device for controlling a gear shift of an automatic transmission, and more particularly, it includes an auxiliary gear shift portion and a main gear shift portion which are connected in series to each other when a reverse speed is achieved. The present invention relates to a shift control device in an automatic transmission that controls switching of both predetermined friction engagement devices in both of these shift parts.

[0002]

2. Description of the Related Art The present applicants have proposed an automatic transmission of this type and a hydraulic control device for controlling the automatic transmission in Japanese Patent Application No. 3-344121 (not known). The structure of the gear train in the automatic transmission will be briefly described as follows.

In FIG. 5, the automatic transmission A shown here is shown.
Includes a torque converter 20, a sub-transmission unit 21, and a main transmission unit 22. The torque converter 20 is
A lock-up clutch 23 is provided. The lock-up clutch 23 is provided between a front cover 25 integrated with a pump impeller 24 and a member (hub) 27 to which a turbine runner 26 is integrally attached. There is.
The crankshaft of the engine (not shown) is connected to the front cover 25, and the turbine runner 26
The input shaft 28, which is connected to, is connected to a carrier 30 of an overdrive planetary gear mechanism 29 that constitutes the auxiliary transmission unit 21.

The carrier 3 in this planetary gear mechanism 29
A multi-plate clutch C0 and a one-way clutch F0 are provided between 0 and the sun gear 31. The one-way clutch F0 is engaged when the sun gear 31 rotates forward relative to the carrier 30 (rotates in the rotation direction of the input shaft 28). Further, a multi-plate brake B0 for selectively stopping the rotation of the sun gear 31 is provided.
The ring gear 3 which is an output element of the subtransmission unit 21
2 is connected to an intermediate shaft 33 which is an input element of the main transmission unit 22.

Therefore, in the sub-transmission unit 21, the entire planetary gear mechanism 29 rotates integrally with the multi-plate clutch C0 or the one-way clutch F0 engaged, so that the intermediate shaft 33 has the same speed as the input shaft 28. It will rotate at low speed. Further, in the state where the brake B0 is engaged and the rotation of the sun gear 31 is stopped, the ring gear 32 is accelerated with respect to the input shaft 28 to rotate in the normal direction, and the high speed stage is established.

On the other hand, the main transmission section 22 is provided with three sets of planetary gear mechanisms 40, 50, 60, and their rotary elements are connected as follows. That is, the sun gear 41 of the first planetary gear mechanism 40 and the sun gear 51 of the second planetary gear mechanism 50 are integrally connected to each other, and the ring gear 43 of the first planetary gear mechanism 40 and the carrier 52 of the second planetary gear mechanism 50 are connected. The third planetary gear mechanism 60 and a carrier 62 are coupled to each other, and the carrier 62 is coupled to an output shaft 65. Further, the ring gear 53 of the second planetary gear mechanism 50 is connected to the sun gear 61 of the third planetary gear mechanism 60.

In the gear train of the main transmission unit 22, it is possible to set a reverse gear and four gears on the forward side, and clutches and brakes therefor are provided as follows. First, the clutch will be described. The ring gear 53 and the third gear of the second planetary gear mechanism 50 which are connected to each other.
A first clutch C1 is provided between the sun gear 61 of the planetary gear mechanism 60 and the intermediate shaft 33, and the sun gear 41 of the first planetary gear mechanism 40 and the sun gear 51 and the intermediate shaft of the second planetary gear mechanism 50 are connected to each other. A second clutch C2 is provided between the first clutch 33 and the second clutch C3.

Next, the brake will be described. The first brake B1 is a band brake, and the sun gears 41 and 5 of the first planetary gear mechanism 40 and the second planetary gear mechanism 50 are used.
It is arranged to stop the rotation of 1. A first one-way clutch F1 and a second brake B2, which is a multi-disc brake, are arranged in series between the sun gears 41 and 51 (that is, the common sun gear shaft) and the casing 66. One way clutch F1 is sun gear 41,5
1 engages when trying to rotate in the reverse direction (rotation in the direction opposite to the rotation direction of the input shaft 28). The third brake B3, which is a multi-disc brake, is the first planetary gear mechanism 4
It is provided between the zero carrier 42 and the casing 66. Then, as a brake for stopping the rotation of the ring gear 63 of the third planetary gear mechanism 60, the fourth brake B4, which is a multi-disc brake, and the second one-way clutch F2 are provided in the casing 6.
6 and 6 are arranged in parallel. The second one-way clutch F2 is adapted to be engaged when the ring gear 63 tries to rotate in the reverse direction.

In the above-described automatic transmission A, it is possible to set five forward speeds and one reverse speed by engaging and disengaging each clutch and brake as shown in the operation table of FIG. In FIG. 6, a circle indicates an engaged state, a circle indicates an engaged state during engine braking, a triangle indicates either engaged or disengaged, and a blank indicates a disengaged state.

As known from the operation table shown in FIG. 6, in the above-described automatic transmission A, the fourth brake is set to the reverse gear and the first gear.
Since it is necessary to engage at the time of high speed engine braking, the hydraulic system according to the above application includes the fourth brake B.
There is an engine brake relay valve that can supply and discharge hydraulic pressure to 4 without switching the 1-2 shift valve.

[0011]

In the above-mentioned automatic transmission or hydraulic control device proposed by the present applicants, it is necessary to engage the fourth brake between the first speed engine braking and the reverse speed. Therefore, hydraulic pressure is supplied to the 4th brake through the 1-2 shift valve for achieving the 1st speed. Therefore, to set the first speed
If the 1-2 shift valve fails to stop in the 2nd speed, the hydraulic pressure cannot be supplied to the 4th brake, and the reverse gear cannot be achieved.

Further, in the above-described automatic transmission, the brake B0 of the auxiliary transmission portion 21 is engaged when the reverse gear is achieved. This is because the gear ratio of the reverse gear is set to a value suitable for traveling, and at the same time, the main transmission portion 22 is provided with the first forward gear.
A smaller torque than in the case of the fourth speed to the fourth speed is input. Therefore, in the reverse gear, the engagement pressure of the friction engagement device in the main transmission portion 22 is reduced. However, if the shift of the sub transmission unit 21 to the overdrive state is delayed in achieving the reverse speed, the torque input to the main transmission unit 22 becomes large, and as a result, the friction in the main transmission unit 22 is increased. There is a possibility that the torque capacity of the engagement device is insufficient and judder occurs, and the riding comfort is reduced, and the durability of the frictional engagement device is reduced.

The present invention has been made in view of the above circumstances, and it is an object of the present invention to provide a shift control device for an automatic transmission that can reliably achieve a reverse gear and is free from the risk of judder. is there.

[0014]

In order to achieve the above-mentioned object, the invention described in claim 1 is such that the sub-transmission portion and the main transmission portion, each of which can achieve a plurality of shift stages, are connected in series. The predetermined friction engagement device connected to the sub transmission unit is engaged, and the predetermined friction engagement device in the main transmission unit is connected from the first valve controlled by the solenoid valve to the first shift valve. In a shift control device for an automatic transmission that achieves a reverse gear by supplying hydraulic pressure to the predetermined friction engagement device to engage the predetermined friction engagement device, the predetermined friction in a main transmission unit is bypassed by bypassing the first shift valve. An oil passage for supplying hydraulic pressure to the engagement device is provided.

Further, according to the invention of claim 1, the oil passage for supplying the hydraulic pressure to the predetermined friction engagement device of the main transmission portion is shut off via the first shift valve in the state where the reverse gear is achieved. Means may further be provided.

Further, in order to achieve the above-mentioned object, the invention according to claim 3 is such that the sub-transmission portion and the main transmission portion, which can achieve a plurality of shift stages, are connected in series to each other, and The predetermined friction engagement device of the transmission unit is engaged, and the predetermined friction engagement device of the main transmission unit is
In the shift control device of the automatic transmission for achieving the reverse speed by supplying the hydraulic pressure to the predetermined frictional engagement device from the valve of the first shift valve to engage the predetermined frictional engagement device, Is configured such that a high speed stage is set by engaging the predetermined friction engagement device provided in the gear section, and hydraulic pressure is supplied to the predetermined friction engagement device of the auxiliary transmission unit when the reverse speed is achieved. A first oil passage and a second oil passage provided in parallel with the first oil passage and passing through the first valve.

And, the invention described in claim 4 is
The sub-transmission unit and the main transmission unit capable of achieving a plurality of shift speeds are connected in series with each other, and a predetermined friction engagement device of the sub-transmission unit is engaged, and a predetermined friction in the main transmission unit is achieved. A shift control device for an automatic transmission that achieves a reverse speed by supplying hydraulic pressure to a predetermined friction engagement device from a first valve through a first shift valve to engage the predetermined friction engagement device, The sub-transmission unit is configured so that a high speed stage is set by engaging the predetermined friction engagement device provided in the sub-transmission unit, and the predetermined friction in the main transmission unit is set when the reverse speed is achieved. Means for increasing the engagement pressure of the engagement device, means for detecting engagement of the predetermined friction engagement device in the main transmission portion when the reverse speed is achieved, and predetermined friction engagement for these main transmission portions Device engagement detected And it is characterized in that it comprises a means for engaging the predetermined frictional engagement device in auxiliary transmission portion.

[0018]

According to the first aspect of the present invention, the hydraulic pressure is supplied to the predetermined friction engagement device of the main speed change portion through the first valve and the first shift valve. Alternatively, it is done via an oil passage that bypasses the first shift valve. Therefore, if the first shift valve fails in a state where the hydraulic pressure supply to the predetermined friction engagement device is interrupted, the hydraulic pressure is supplied to the friction engagement device via the oil passage. Therefore, the achievement of the reverse gear is ensured.

Further, in the invention described in claim 2, after the reverse gear is achieved, the supply of the hydraulic pressure to the predetermined friction engagement device in the main transmission portion via the first shift valve is cut off. . That is, the first shift valve outputs the hydraulic pressure from the predetermined port even when the gear shift stage other than the reverse gear is achieved. Therefore, in the case of failure in this state, the reverse gear should be set. When the hydraulic pressure is supplied to the predetermined friction engagement device, the friction engagement device to be released in the reverse gear may be engaged, and thus the friction engagement for the reverse gear is passed through the first shift valve. By shutting off the supply of hydraulic pressure to the device, it is possible to prevent the hydraulic pressure from being supplied to the friction engagement device to be released in the reverse gear.

Further, according to the third aspect of the invention, when the reverse speed is achieved, the hydraulic pressure is supplied to the predetermined friction engagement device in the auxiliary transmission section through the first oil passage and the second oil passage. Done. Since the high speed stage is achieved by engaging the friction engagement device in the sub-transmission portion, the engagement of the friction engagement device is achieved by supplying hydraulic pressure through the two oil passages. That is, the high speed stage is achieved quickly, and as a result, the torque input to the main transmission unit can be reliably reduced when the reverse stage is achieved. That is, judder in the friction engagement device in the main transmission portion is prevented.

Further, in the invention described in claim 4, when the friction engagement device of the main speed change portion is quickly engaged with the friction engagement device of the auxiliary speed change portion in achieving the reverse speed, the main speed change portion is The engagement pressure of the friction engagement device is set high,
After the engagement of the friction engagement device in the main transmission portion is completed, the friction engagement device in the sub transmission portion is engaged. That is, when the frictional engagement device of the main transmission unit is engaged, the torque input to the main transmission unit is large because the auxiliary transmission unit is not in the high speed stage. Since the resultant pressure is high and the torque capacity thereof is sufficiently large, judder in the friction engagement device in the main transmission portion is prevented.

[0022]

Embodiments of the present invention will now be described with reference to the drawings. In addition, the embodiment described below is based on FIG.
The present invention is intended for an automatic transmission A having a gear train shown in FIG. 6, and therefore the gear stages that can be achieved and the engagement / disengagement state of the friction engagement device for achieving each gear stage are shown in FIG. As shown in.

FIG. 1 is an overall control system diagram showing an embodiment of the present invention. An engine E to which an automatic transmission A is connected has an intake pipe 12 in which a main throttle valve 13 and an upstream thereof are provided. Sub throttle valve 14 located on the side
And have. The main throttle valve 13 is connected to an accelerator pedal 15, and the accelerator pedal 1
It is opened and closed according to the amount of depression of 5. The sub-throttle valve 14 is opened and closed by a motor 16. An engine electronic control unit (E-ECU) 17 for controlling the motor 16 for adjusting the opening of the sub-throttle valve 14 and for controlling the fuel injection amount and ignition timing of the engine E is provided. There is.
The electronic control unit 17 is a central processing unit (CPU).
The electronic control unit 17 mainly includes a storage device (RAM, ROM) and an input / output interface. The electronic control unit 17 has engine (E / G) rotation speed N and intake air amount Q as data for control. Various signals such as intake air temperature, throttle opening, vehicle speed, engine water temperature, and signals from the brake switch are input.

In the automatic transmission A, the hydraulic pressure control device 18 controls gear shifting and lockup clutch, line pressure, or engagement pressure of a predetermined friction engagement device. The hydraulic control device 18 is configured to be electrically controlled, and also has first to third shift solenoid valves S1 to S3 for executing a shift and a first to third engine for controlling an engine braking state. 4 solenoid valve S4, linear solenoid valve SLT for controlling the line pressure, linear solenoid valve SLN for controlling the back pressure of the accumulator, linear for controlling the engagement pressure of a lock-up clutch or a predetermined friction engagement device A solenoid valve SLU is provided.

An electronic control unit (T-ECU) 19 for an automatic transmission that outputs a signal to these solenoid valves to control gear shift, line pressure, accumulator back pressure, etc.
Is provided. This automatic transmission electronic control unit 19
Is a central processing unit (CPU) and a storage device (RA
M, ROM) and an input / output interface, and the electronic control unit 19 has a throttle opening, vehicle speed, engine water temperature, a signal from a brake switch, a shift position, as data for control.
The signal from the pattern select switch, the signal from the overdrive switch, the signal from the C0 sensor that detects the rotational speed of the clutch C0, which will be described later, the signal from the C2 sensor that detects the rotational speed of the second clutch C2, and the automatic transmission Oil temperature, signals from the manual shift switch, etc. are input.

The electronic control unit 19 for the automatic transmission and the electronic control unit 17 for the engine are connected to each other so that data can be communicated with each other, and the electronic control unit 17 for the engine transfers to the electronic control unit 19 for the automatic transmission. On the other hand, a signal such as the intake air amount per rotation (Q / N) is transmitted, and an instruction signal for each solenoid valve is sent from the automatic transmission electronic control unit 19 to the engine electronic control unit 17. A signal equivalent to, a signal instructing a shift speed, and the like are transmitted.

That is, the electronic control unit 19 for the automatic transmission
Is based on the input data and the map stored in advance, and the ON / OFF of the gear position and the lockup clutch is performed.
F, or the line pressure or the adjustment level of the engagement pressure is judged, and based on the judgment result, an instruction signal is output to a predetermined solenoid valve, and further judgment of fail or control based on it is performed. . In addition to controlling the fuel injection amount, the ignition timing, the opening degree of the sub-throttle valve 14, etc. based on the input data, the electronic control unit 17 for the engine also sets the fuel injection amount during the shift in the automatic transmission A. The output torque is temporarily reduced by reducing the amount, changing the ignition timing, or narrowing the opening of the sub-throttle valve 14.

In the above-described automatic transmission A, a shift lever (not shown) is operated in the same manner as a normal automatic transmission for the reverse gear and the range in which the engine brake is applied at the first speed to the third speed. It is designed to be set by
The array of the ranges is as shown in FIG. That is, the reverse (R) range position is arranged following the parking (P) range position, and the neutral (N) range position is provided following the R range at a position diagonal to the arrangement direction. The drive (D) range position is arranged parallel to the N range with the arrangement direction of the P range position and the R range position, and the fourth speed range position is a direction orthogonal to these arrangement directions. It is placed in a bent position. Furthermore, the 3rd speed range position is different from the 4th speed range position in the N range and the D range.
The second speed range position is arranged in a direction parallel to the arrangement direction with the range, and the second speed range position is provided at a position having the same relationship as the N range position with respect to the R range position, and the low (L) range position is the D range position. It is provided at a position having the same relationship as the fourth speed range position with respect to.

Of the traveling ranges, in the D range, the 5 forward speeds shown in FIG. 6 can be achieved, whereas in the 4th speed range, the 4th forward speed without the 5th speed, which is the overdrive speed, is achieved. In addition, in the third speed range, up to the third speed can be achieved, in the second speed range, up to the second speed, respectively, and in the L range, only the first speed can be achieved. be able to.

As described above, in the automatic transmission A shown in FIG. 1, the fourth brake B4, which is engaged to achieve the reverse gear, is engaged even in the engine braking state of the first speed, and in the reverse gear. The brake B0 of the subtransmission unit 21 is engaged. Therefore, the hydraulic circuit shown in FIG. 3 is provided.

In FIG. 3, reference numeral 70 designates a manual valve interlocked with a shift lever, and a line pressure oil passage 72 is connected to an input port 71 thereof. The line pressure oil passage 72 is connected to the input port 74 of the pressure control valve 73. The pressure control valve 73 is a pressure regulating valve whose pressure regulation level is controlled by a linear solenoid valve SLN for accumulator back pressure, and reduces the line pressure PL according to the pressure regulation level to output the engine brake relay from the output port 75. It outputs to the valve 76. The pressure control valve 73 is configured so that the higher the signal pressure from the linear solenoid valve SLN, the lower the pressure adjustment level.

The engine brake relay valve 76 is a valve mainly for controlling the supply of hydraulic pressure to a predetermined friction engagement device when the engine brake is applied, and is formed on the side opposite to the spring 78 with the spool 77 interposed therebetween. The fourth solenoid valve S4 is connected to the control port 79. This fourth solenoid valve S4 is
It is a valve that stops outputting the signal pressure in the N state and outputs the signal pressure in the OFF state. Therefore, the spool 77 of the engine brake relay valve 76 is shown in the left half of the figure when the fourth solenoid valve S4 is ON. Is pushed up to the position, and the 4th solenoid valve S4 is turned off.
At this time, the spool 77 is pushed down to the position shown in the right half of the figure.

Further, the engine brake relay valve 76 has first and second input ports 80 and 81 connected to the output port 75 of the pressure control valve 73. These input ports 80, 8
Reference numeral 1 denotes a port which is communicated with the output ports 82 and 83 when the control port 79 is supplied with a signal pressure in a so-called ON state, and when the spool 77 is at the position shown in the right half of the figure, the first input Port 80 is the first output port 8
The second input port 81 communicates with the second output port 83. The first output port 82 is connected to the 1-2 shift valve 84, and the second output port 83 is
-5 is connected to the shift valve 85.

The 1-2 shift valve 84 pushes up the spool 86 to the position shown in the left half of the figure when setting the second speed to the fifth speed, and sets the first speed and the N range and the R range. In this case, the spool 86 is configured to be pushed down to the position shown in the right half of the figure. The input port 87, which is connected to the first output port 82 of the engine brake relay valve 76, communicates with the B-1 brake port 88 in the second to fifth speeds.
In the speed, N range and R range, it communicates with the B-4 brake port 89. Of these brake ports 88 and 89, the B-1 brake port 88 is
It is connected to the first brake B1 via a 2-3 shift valve 90. The B-4 brake port 88 is connected to the fourth brake B4 via a shuttle valve 91.

The 2-3 shift valve 90 is used in the first and second speeds, in the N range and the R range.
The hydraulic pressure input from the B-1 brake port 88 is output to the first brake B1.

The hydraulic circuit shown in FIG. 3 has a fourth brake B4.
In addition to the oil passage via the engine brake relay valve 76 and the 1-2 shift valve 84 described above, an oil passage for supplying hydraulic pressure to the fourth brake B4 in the R range is provided. That is, in the manual valve 70, the R port 92 communicating with the input port 71 when the R range is selected is connected to the input port 94 of the reverse control valve 93 via the oil passage 95. This reverse control valve 93 is the second solenoid valve S2.
The input port 94 and the output port 96 are configured to communicate with each other when a signal pressure is supplied from the output port 96, and the output port 96 is connected to the shuttle valve 91 via an oil passage 97 and an orifice 98 with a check ball. ing. Further, the oil passage 97 is provided with another shuttle valve 99 and an orifice 100 with a check ball valve.
It is connected to the second clutch C2 via. The second solenoid valve S2 is configured to output the signal pressure in the OFF state. Therefore, when the solenoid valve S2 is turned OFF, the hydraulic pressure is supplied to the fourth brake B4 via the reverse control valve 93. can do.

On the other hand, the 4-5 shift valve 85 is provided in the overdrive stage of the fifth speed and the R range and the second speed.
Brake B of the sub-transmission unit 21 in the engine braking state of high speed
A line pressure oil passage 72 is connected to the first input port 101, and the engine brake relay valve 76 is connected to the second input port 102.
Second output port 83 is connected, and the oil passage 97 is connected to the third input port 103. And this
The 4-5 shift valve 85 is used for the first to fourth speeds and the N speed.
In the range, the spool 104 is pushed up to the position shown in the left half of the figure, and in the fifth speed and the R range, the spool 104 is pushed up.
Is configured to be pushed down to the position shown in the right half of the figure. As a result, in the first to fourth speeds and the N range, the first and second input ports 101 and 102 are closed, the third input port 103 communicates with the second output port 105, and the first speed and In the R range, the first input port 101 communicates with the first output port 106,
In addition, the second input port 102 communicates with the second output port 105. The first output port 106 is connected to the brake B0 via the orifice 107 with a check ball, and the second output port 105 is directly connected to the brake B0.

Reference numeral 108 in FIG. 3 denotes the second clutch C.
The accumulator for the brake B0 is indicated by reference numeral 109, and the back pressure of the accumulators 108, 109 is controlled by the linear solenoid valve SLN. Although not particularly shown, the shift valves 84, 85 and 90 described above are controlled by the first to third solenoid valves S1 to S3.

Next, the operation when the reverse stage is achieved by the above hydraulic circuit will be described. When the reverse gear is achieved, the R port 92 of the manual valve 70 communicates with the input port 71, and the spool 86 of the 1-2 shift valve 84 is pushed down to the position shown in the right half of the figure, and further 4-5 The spool 104 of the shift valve 85 is pushed down to the position shown in the right half of the figure. The fourth solenoid valve S4 is controlled to be OFF at the same time when the shift to the reverse gear is determined. Therefore, the engine brake relay valve 7
Since the signal pressure is supplied from the fourth solenoid valve S4 to the control port 79 of No. 6, the engine brake relay valve 7
The spool 77 of No. 6 is pushed down to the position shown in the right half of the figure to be in the so-called ON state. As a result, the hydraulic pressure regulated by the pressure control valve 73 passes from the input port 81 through the first output port 82 to the 1-2 shift valve 8
No. 4 input port 87, and is further supplied from the B-4 brake port 89 through the shuttle valve 91 to the fourth brake B4.

Further, by turning off the second solenoid valve S2, the oil passage 95 and the oil passage 97 communicate with each other through the reverse control valve 93. Therefore, the oil passage 97 and the shuttle valve 91 are connected to the fourth brake B4. The hydraulic pressure is supplied via. In other words, when the hydraulic pressure cannot be supplied to the fourth brake B4 via these valves 76, 84 due to the failure of the engine brake relay valve 76, the 1-2 shift valve 84 or the fourth solenoid valve S4. Also, it is possible to secure the supply of hydraulic pressure to the fourth brake B4 via the oil passage 97.

Hydraulic pressure is supplied to the second clutch C2 through the oil passage 97 and the shuttle valve 99.

On the other hand, since the 4-5 shift valve 85 is in the above-mentioned state and the first input port 101 thereof communicates with the first output port 106, the line pressure PL is supplied from the line pressure oil passage 72 to the brake B0. To be done. At the same time, the second input port 81 of the engine brake relay valve 76
Is connected to the second output port 83, and the hydraulic pressure is supplied from here to the second input port 102 of the 4-5 shift valve 85. Therefore, the brake B0 is connected to the 4-5 shift valve 8
The hydraulic pressure is also supplied from the second output port 105 of No. 5. That is, when the reverse gear is achieved, the brake B0 of the subtransmission unit 21 is hydraulically supplied through the two hydraulic systems, so that the brake B0 is engaged prior to the fourth brake B4 and the second clutch C2. After the sub transmission unit 21 is shifted to the high speed stage, the main transmission unit 22 is in the reverse stage state. Therefore, when the reverse gear is reached, the line pressure PL is lowered to reduce the fourth brake B4.
Even if the torque capacity of the second clutch C2 is reduced, the input torque to the main transmission portion 22 is low, so that judder does not occur in these friction engagement devices.

After the reverse gear is achieved as described above,
Turn on the 4th solenoid valve S4 to stop the output of signal pressure. That is, the engine brake relay valve 76
Is placed in the so-called OFF state in which the spool 77 is in the position shown in the left half of the figure. By doing this,
Since the supply of the hydraulic pressure to the 1-2 shift valve 84 is cut off, when the 1-2 shift valve 84 sticks to the second speed to the fifth speed, the first brake B1 is connected to the fourth brake B4.
It is possible to prevent the hydraulic pressure for the brake B4 from flowing in and the so-called double-locked state from occurring.

By the way, in the above-described automatic transmission A, it is necessary to advance the auxiliary transmission unit 21 to the high speed stage when the reverse speed is achieved.
Supplying hydraulic pressure by the system is as described above. However, if a failure occurs in which the fourth solenoid valve S4 remains in the ON state or a failure occurs in which the engine brake relay valve 76 remains in the so-called OFF state,
It becomes impossible to supply hydraulic pressure (first apply) from the two systems to the brake B0. In such a case, control is performed as shown in FIG.

FIG. 4 is a flowchart showing a control routine in the case where a failure occurs in which the fourth solenoid valve S4 remains in the ON state, and the fourth solenoid valve S4 is determined after the shift to the reverse gear is judged. Determines whether or not has failed (step 1). If it has not failed, the routine returns. If it has failed, hydraulic pressure is supplied to the clutch C2 and the brakes B0 and B4 for achieving the reverse gear. Control is executed (step 2). For example, if the first to fourth solenoid valves S1 to S4 are OF
Set to F. Then, the back pressure in the accumulator 108 for the second clutch C2 is increased (step 3). This can be controlled by the linear solenoid valve SLN, which increases the engagement pressure of the second clutch C2 and increases its torque capacity. At the same time, torque reduction control of the engine E is executed (step 4). This is performed, for example, by performing retard control of the ignition timing in the engine E and / or reducing the fuel injection amount and further narrowing the sub throttle valve 14. In this state, waiting for the brake B0 of the subtransmission unit 21 to be engaged, and when the engagement of the brake B0 is detected,
That is, when the determination result of step 5 is "yes", the torque reduction control of the engine E is terminated (step 6), and the back pressure is reduced (step 7).

Therefore, by performing such control, in order to achieve the reverse gear, the friction engagement devices C2 and B4 of the main transmission portion 22 engage before the brake B0 of the auxiliary transmission portion 21, and therefore, Even if the input torque to the main transmission unit 22 due to the low speed of the sub transmission unit 21 is large, the torque capacity of the clutch C2 that receives the input torque is large, so that the clutch C2 is free from judder.

The present invention is not limited to the above embodiment, and is also applied to a shift control device for an automatic transmission having a gear train other than the gear train shown in FIG. be able to.

[0048]

As described above, according to the shift control device of the present invention, a path via a shift valve and a path via a shift valve are provided as a hydraulic pressure supply system for a friction engagement device to be engaged when a reverse speed is achieved. By providing a bypass path,
Even if the shift valve or the solenoid valve that controls this fails, the reverse speed can be achieved reliably.
Failsafe can be established. Also, after the achievement of reverse gear,
If the supply system via the shift valve is shut off, simultaneous supply due to failure can be prevented.

Further, according to the present invention, since two hydraulic pressure supply systems are provided for the friction engagement device of the auxiliary transmission section which is set to the high speed stage when the reverse gear is achieved, when the reverse gear is achieved, Since the sub-transmission unit precedes to the high speed stage, it is possible to reduce the input torque to the main transmission unit and prevent the occurrence of judder in the main transmission unit.

When the sub-transmission portion cannot be advanced to the high speed stage, the friction engagement device of the main transmission portion is made to have a high engagement pressure, so that the judder is prevented even if the input torque to the main transmission portion is large. can do.

[Brief description of drawings]

FIG. 1 is a block diagram schematically showing a control system of an embodiment of the present invention.

FIG. 2 is a diagram showing an arrangement of shift positions for selecting each traveling range.

FIG. 3 is a diagram showing a part of a hydraulic circuit used in the present invention.

FIG. 4 is a flowchart showing a control routine when a fourth solenoid valve fails when a reverse speed is achieved.

FIG. 5 is a skeleton diagram showing an example of a gear train of an automatic transmission targeted by the present invention.

FIG. 6 is a diagram showing an operation table for setting each shift speed.

[Explanation of symbols]

 21 Auxiliary transmission section 22 Main transmission section 72 Line pressure oil passage 76 Engine brake relay valve 84 1-2 Shift valve 85 4-5 Shift valve 95, 97 Oil passage 108 Accumulator C2 Second clutch B0 Brake B4 Fourth brake S4 Fourth Solenoid valve SLN Linear solenoid valve for accumulator

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Jun Tabata 1 Toyota-cho, Toyota City, Aichi Prefecture Toyota Automobile Co., Ltd. (72) Inventor Masahiko Ando 10, Takane, Fujii-cho, Aichi Prefecture Aisin AW Within the corporation

Claims (4)

[Claims] 1. A sub-transmission unit and a main transmission unit, each of which can achieve a plurality of shift speeds, are connected in series to each other,
The predetermined friction engagement device of the sub-transmission unit is engaged, and the predetermined friction engagement device of the main transmission unit is connected to the predetermined friction engagement device via a first valve controlled by a solenoid valve. A shift control device for an automatic transmission that achieves a reverse speed by supplying hydraulic pressure to a friction engagement device to engage the friction engagement device, wherein the predetermined friction engagement device in a main transmission unit bypasses the first shift valve. A shift control device for an automatic transmission, characterized in that an oil passage for supplying hydraulic pressure is provided in the. 2. A means for shutting off an oil passage for supplying a hydraulic pressure to a predetermined friction engagement device of the main transmission unit via the first shift valve in a state where the reverse gear is achieved. The shift control device for an automatic transmission according to claim 1, wherein: 3. A sub-transmission unit and a main transmission unit, each of which can achieve a plurality of shift speeds, are connected in series with each other,
Further, a predetermined friction engagement device of the auxiliary transmission unit is engaged, and the predetermined friction engagement device of the main transmission unit is hydraulically operated from the first valve to the predetermined friction engagement device via the first shift valve. In a shift control device for an automatic transmission that achieves a reverse speed by supplying and engaging with a high speed by engaging the predetermined friction engagement device provided in the sub speed change unit with the sub speed change unit. A first oil passage configured to set a gear and supplying hydraulic pressure to the predetermined friction engagement device of the sub transmission unit when the reverse gear is achieved; and a first oil passage provided in parallel with the first oil passage. A shift control device for an automatic transmission, characterized in that a second oil passage passing through the first valve is provided. 4. An auxiliary transmission unit and a main transmission unit, each of which can achieve a plurality of shift speeds, are connected in series with each other,
Further, a predetermined friction engagement device of the auxiliary transmission unit is engaged, and the predetermined friction engagement device of the main transmission unit is hydraulically operated from the first valve to the predetermined friction engagement device via the first shift valve. In a shift control device for an automatic transmission that achieves a reverse speed by supplying and engaging with a high speed by engaging the predetermined friction engagement device provided in the sub speed change unit with the sub speed change unit. A means for increasing the engagement pressure of the predetermined friction engagement device in the main speed change portion when the reverse speed is achieved, and a predetermined friction in the main speed change portion when the reverse speed is achieved. Means for detecting the engagement of the engagement device, and means for engaging the predetermined friction engagement device in the auxiliary transmission unit after the engagement of the predetermined friction engagement device in the main transmission unit is detected. Is equipped with A shift control device for an automatic transmission.