JPH05322019A - Oil pressure control unit for automatic transmission - Google Patents

Abstract

(57) [Summary] [Purpose] To prevent the delay of pressure oil supply due to the decrease of residual oil amount. A hydraulic control device for an automatic transmission A having a friction engagement device 3 provided with an oil discharge mechanism 2 for promoting the discharge of pressure oil from a hydraulic chamber 1 is provided before engagement of the friction engagement device 3. A residual oil amount determination means 4 for determining the amount of oil remaining in the friction engagement device 3 and a supply speed adjustment means 5 for changing the supply speed of the pressure oil to the friction engagement device 3 according to the residual oil amount. It has. Therefore, even when the amount of residual oil is small,
Since there is no delay in the supply of pressure oil, it is possible to prevent a shift shock and a shift response delay.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hydraulic control device for controlling engagement and disengagement of a friction engagement device for setting a predetermined shift speed in an automatic transmission for a vehicle.

[0002]

2. Description of the Related Art As is well known, an automatic transmission for a vehicle is configured to set a predetermined shift speed by appropriately engaging or disengaging a friction engagement device such as a clutch or a brake. Is. Therefore, in this type of automatic transmission, the engagement and disengagement states of the friction engagement device are switched to carry out the gear shifting, and therefore, if the engagement state or the disengagement state is rapidly switched, the output is output. The shaft torque changes abruptly and shift shock occurs. On the other hand, if the speed of engagement or disengagement of the friction engagement device is too slow, the friction engagement device slips excessively and its durability deteriorates, or a so-called double lock state occurs and the gear shifting Shock may increase.

Therefore, for example, in the invention disclosed in Japanese Patent Laid-Open No. 3-204467, an orifice is provided in an oil passage for supplying pressure oil to a predetermined friction engagement device, and the friction member is bypassed to the orifice. A bypass oil passage for supplying pressure oil to the coupling device is provided, and further opening / closing means for opening / closing the bypass oil passage is provided.When the opening / closing means is closed, the pressure oil is supplied only from the oil passage provided with the orifice. Since the speed becomes slower, and when the opening / closing means is opened, the pressure oil is supplied from both oil passages to increase the speed, so by controlling the opening / closing means according to the output shaft torque, Prevents shift shock.

[0004]

As in the above-mentioned conventional invention, if the pressure oil supply speed to the friction engagement device is changed, the way of increasing the torque capacity is changed, so that the pressure oil supply speed is output. If it is possible to cope with the change in the shaft torque, the shift shock may be reduced. However, in a friction engagement device such as a clutch equipped with an oil drainage mechanism such as a check ball, bleed orifice, or leaf valve, the amount of air that has entered the hydraulic chamber, that is, the residual amount of pressure oil, is the torque of the friction engagement device. This has a great influence on the change in the capacity. Therefore, in the above-mentioned conventional invention, it may not be possible to properly control the pressure oil supply speed to the friction engagement device provided with this type of oil discharge mechanism.

Explaining one example thereof, for example, when two friction engagement devices are simultaneously switched from the released state to the engagement state to set a predetermined shift speed, they remain in the hydraulic chambers of the respective friction engagement devices. If there is a large difference in the amount of pressure oil, the torque capacity of either one of the friction engagement devices will increase first, and a gear speed other than the target gear speed will be set, or gear shock will occur. To do.

The present invention has been made in view of the above circumstances, and the friction engagement is performed by controlling the supply speed of the pressure oil to the friction engagement device according to the amount of the pressure oil remaining in the friction engagement device. An object of the present invention is to provide a hydraulic control device capable of appropriately controlling the change in torque capacity of the device.

[0007]

In order to achieve the above object, the invention described in claim 1 is configured as shown in FIG. That is, the invention of claim 1 is the hydraulic chamber 1
A hydraulic control device for an automatic transmission A having a friction engagement device 3 provided with an oil drainage mechanism 2 for promoting the discharge of pressure oil from the friction engagement device 3 before engagement of the friction engagement device 3. And a supply speed adjusting means 5 for changing the supply speed of the pressure oil to the friction engagement device 3 according to the residual oil amount. It is a feature.

The invention according to claim 2 provides a friction engagement device 3 provided with an oil discharge mechanism 2 for promoting discharge of pressure oil from the hydraulic chamber 1 at a predetermined forward speed of the second speed or higher. At least two friction engagement devices 3 and 6 are engaged and set, and the first speed is set by engagement with any one of the friction engagement devices 3 and 6, and the neutral state is set. In the hydraulic control device of the automatic transmission A that sets the first forward speed after setting the predetermined forward speed when shifting from the forward traveling state to the forward traveling state, the engagement of the friction engagement device 3 including the oil drainage mechanism 2 is performed. Any of the remaining oil amount determination means 4 for obtaining the amount of oil remaining in the previous friction engagement device 3 and at least two friction engagement devices 3, 6 engaged to set the predetermined forward speed. Supply speed adjusting means for changing the supply speed of pressure oil to the car according to the residual oil amount And it is characterized in that it comprises and.

[0009]

The invention described in claim 1 is directed to the hydraulic control device of the automatic transmission A having the friction engagement device 3 provided with the oil drainage mechanism 2, and the friction engagement device 3 is engaged. The amount of pressure oil remaining in the friction engagement device 3 before is obtained by the residual oil amount determination means 4. When supplying the pressure oil to engage the friction engagement device 3, the supply speed adjusting means 5 adjusts the supply speed of the pressure oil according to the residual oil amount of the friction engagement device 3. Therefore, the friction engagement device 3
The change in the torque capacity when engaging the is optimized.

Further, in the automatic transmission which is the object of the present invention as defined in claim 2, at least two or more predetermined forward gears including the second speed or higher include the friction engagement device 3 having the oil drainage mechanism 2. It is set by engaging the friction engagement devices 3 and 6. The forward gear is set when shifting from the neutral state to the forward running state. In that case, the residual oil amount determining means 4 determines the residual oil amount in the friction engagement device 3, and based on the result, the friction between the two The supply speed adjusting means 5 adjusts the supply speed of the pressure oil to one of the engagement devices 3 and 6. Therefore, since the torque capacities of the two friction engagement devices 3 and 6 can be increased in synchronization with each other, the so-called squat can be prevented by preventing the first speed from being set before the predetermined forward speed is set. Control can be performed.

[0011]

Embodiments of the present invention will now be described with reference to the drawings. FIG. 3 is a diagram schematically showing an embodiment of the present invention, in which two sets of planetary gear mechanisms 12 and 13 are mainly operated by controlling a solenoid valve of a hydraulic circuit 11 by an electronic control unit (ECU) 10. The gear train is set to 4 forward gears and 1 reverse gear.

The electronic control unit 10 mainly comprises a central processing unit (CPU), storage elements (ROM, RAM) and an input / output interface (I / O), and vehicle speed (V) is used as control data. Sensor, throttle opening (θ) sensor, overdrive switch (O
/ D Sw), a shift position sensor, a brake switch, an idling switch (I / D Sw) (not shown), and the like. Then, the electronic control unit 10 determines the shift stage to be set based on the input data, drives the solenoid valve in the hydraulic circuit 11 so as to set the shift stage, and controls the hydraulic pressure during the shift transition. Is becoming A specific example of this hydraulic circuit will be described later.

Explaining the gear train shown in FIG. 3, the planetary gear mechanisms 12, which are arranged on the same axis as each other,
3, the carrier 14 of the first planetary gear mechanism 12 on the right side of FIG. 3 and the ring gear 15 of the second planetary gear mechanism 13 are connected, and the ring gear 16 of the first planetary gear mechanism 12 and the second planetary gear mechanism 13 are connected. It is connected to the carrier 17.

An input shaft Is is arranged along the central axes of these planetary gear mechanisms 12 and 13, and the input shaft I
s and the sun gear 18 in the first planetary gear mechanism 12 are provided with a first clutch C1, and the second clutch C2 is provided between the input shaft Is and the carrier 17 in the second planetary gear mechanism 13. These clutches C1, C
Of the two, a clutch without an oil drainage mechanism such as a check ball is used as the first clutch C1, and a clutch having an oil drainage mechanism is used as the second clutch C2. Further, a third clutch C3 is provided between the input shaft Is and the sun gear 19 of the second planetary gear mechanism 13. On the other hand, a fourth clutch C4 and a first one-way clutch F1 which are arranged in series with each other are provided between the carrier 17 and the sun gear 19 in the second planetary gear mechanism 13. In the first one-way clutch F1, the rotation direction of the clutch drum of the fourth clutch C4, that is, the rotation direction of the sun gear 19 in the state where the fourth clutch C4 is engaged is a positive rotation direction (input It engages when it is in the same rotation direction as the rotation direction of the shaft Is). Between the clutch drum of the fourth clutch C4 and the housing Hu, there is provided a second one-way clutch F2 which is engaged when the clutch drum tries to rotate in the reverse direction (rotation in the direction opposite to the input shaft Is). Has been.

As a braking means, a first brake B1 which is a band brake is provided on the outer periphery of the clutch drum of the fourth clutch C4, and the first brakes are connected to each other.
The second brake B that stops the rotation of the ring gear 16 of the planetary gear mechanism 12 and the carrier 17 of the second planetary gear mechanism 13.
2 is provided between the housing Hu and the housing Hu. Therefore, the first brake B1 is connected to the fourth clutch C4 or the first clutch B4.
The rotation of the carrier 17 and the rotation of the sun gear 19 in the second planetary gear mechanism 13 are selectively stopped via the one-way clutch F1.

Next, an example of the hydraulic circuit 11 is shown in FIGS. In these figures, the oil pump and the means for adjusting the hydraulic pressure generated by the oil pump to the line pressure PL, the means for controlling the lock-up clutch, and the means for controlling the accumulator back pressure are conventionally known ones. This is omitted because it can be done. 4 and 5, the numbers with a circle indicate that the parts indicated by the same numbers are connected.

The hydraulic circuits shown in these figures have a manual valve 20, a 1-2 shift valve 30, a 2-3 shift valve 50, and a 3-4 shift valve 7 in order to set each shift speed.
0, B1 control valve 80 and solenoid valves 90 for controlling each shift valve 30, 50, 70,
91 and 92 are provided.

The manual valve 20 selects the P (parking) range, the R (reverse) range, the N (neutral) range, the D (drive) range, and the L range by being manually operated as in the conventional valve. When the D range is selected, the spool 21 moves to the left from the position shown in the figure, and the input port 22 connecting the line pressure oil passage 100 is connected to the D port 23.
When the L range is selected, the spool 21 moves to the left end of the figure so that the input port 22 communicates with the D port 23 and the L port 25. On the other hand, when the R range is selected, the spool 21 moves from the position shown to the right and the input port 22 is set to the R port 26.
Only communicate with. Further, when the N range is selected, the spool 21 is at the position shown in the drawing, and the input port 2
The communication between the port 2 and other ports is blocked, and when the P range is selected, the input port 22 is closed by the spool 21.

The 1-2 shift valve 30 has a spool 31 in which five lands are formed and a spring 32 that presses the spool 31 in one direction (upward in the drawing), and the spring 32 is arranged. The control port 33 formed at the end opposite to the above end is connected to the D port 23 of the manual valve 20 via the oil passage 101.
A normally open type second solenoid valve 91 is connected to the oil passage 101 through a strainer 102 and an orifice 103.
And the second solenoid valve 91 is O
The pressure is discharged from the oil passage 101 when FF, and the line pressure PL is generated in the oil passage 101 when ON. Further, the first D port 34 of the 1-2 shift valve 30 is communicated with the D port 23 of the manual valve 20 via the oil passage 104 that bypasses the strainer 102 and the second solenoid valve 91, and the spool 31 has the spring 32. The fourth clutch C4 is connected to the clutch port 35, which is communicated with the first D port 34 when it is pushed to the right side of the drawing. The fourth clutch C4 has an accumulator 105.
Is attached.

Further, the 1-2 shift valve 30 has a second D port 36, a third D port 37, a brake port 38, a drain port 39, and an R port which are selectively communicated with the clutch port 35 from the upper side in the illustrated state. 40, a brake port 41, an L port 42, a fourth D port 43, a clutch port 44, and a hold port 45 are formed.
Of these, the second brake B2 is connected to the brake port 41.

On the other hand, the 2-3 shift valve 50 has two spools 51 and 52 arranged continuously on the same axis.
And a spring 53 that presses these spools 51 and 52 in one direction (upward direction in the drawing), and a control formed at the end opposite to the end where the spring 53 is arranged. The port 54 branches from the line pressure oil passage 100 and has a strainer 106 and an orifice 107.
Further, an oil passage 108 having a normally open type first solenoid valve 90 interposed therein is connected. Therefore this first
Control port 5 when solenoid valve 90 is OFF
4, the spools 51 and 52 have springs 53.
When the first solenoid valve 90 is turned on, the line pressure PL acts on the control port 54 to move the spools 51 and 52 to the positions shown on the right side of the drawing. It can be pushed down.

The 2-3 shift valve 50 includes the first to third valves connected to the D port 23 of the manual valve 20.
D port 55, 56, 57 are formed, and the clutch port 58, which is connected to and disconnected from the first D port 55, is connected to the third D port 43 of the 1-2 shift valve 30. Also, the second D port 5
6 and the drain port 59 are selectively connected to the brake port 60, which is the third shift port 3 of the 1-2 shift valve 30.
Connected to 7. Further, a clutch port 62 that selectively communicates with the third D port 57 and the drain port 61.
Are connected to the second D port 36 and the hold port 45 of the 1-2 shift valve 30. On the other hand, the clutch port 62 is connected to the second clutch C2 via the orifice 116. Reference numeral 109 is an accumulator.

Further, the 2-3 shift valve 50 has an L port 6 connected to the L port 25 of the manual valve 20.
3 is formed, and the brake port 65 selectively communicating with the L port 63 and the drain port 64 is connected to the L port 42 of the 1-2 shift valve 30 via the low coast modulator valve 110. There is. In addition,
The low coast modulator valve 110 is for reducing the shift shock when the range is switched to the L range, and a generally used conventional valve can be adopted. Also, a clutch port 67 selectively connected to the third D port 57 and the other drain port 66.
Is provided.

The 3-4 shift valve 70 includes the first clutch C1.
And a first brake B1 for simultaneously switching the supply and discharge of hydraulic pressure to and from the two engaging elements. A spool 71 having three lands and the spool 71 are pressed in one direction (upward in the figure). And a spring 72 that operates. The control port 73 provided at the end opposite to the end where the spring 72 is arranged is provided with the 1-2 shift valve 30.
The 3-4 shift valve 70 is connected to the control port 33, and the second solenoid valve 91 is used to apply the line pressure PL to the control port 73 of the 3-4 shift valve 70 and discharge the line pressure PL.

The 3-4 shift valve 70 has 1-2
A first D port 74 connected to the brake port 38 in the shift valve 30 is formed, and the manual valve 2 is provided via the first D port 74 and the oil passage 104.
A brake port 76 that selectively communicates with the second D port 75 connected to the 0 D port 23 is formed.
Further, a third D port 77 and a hold port 78 connected to the clutch port 67 of the 2-3 shift valve 50 described above are formed, and these second D port 75 are formed.
The first clutch C1 is connected to a clutch port 79 that selectively communicates with the third D port 77. Hydraulic pressure is supplied from the clutch port 79 to the first clutch C1 via an accumulator 111.

The first clutch C1 is the above-mentioned 1-2
It is also connected to the clutch port 44 of the shift valve 30.

3-4 Downstream of the shift valve 70, that is, 3-
The B1 control valve 80 is arranged on the downstream side when the hydraulic pressure is supplied from the 4 shift valve 70 to the first brake B1. The B1 control valve 80, as its name implies, is for controlling the hydraulic pressure supplied from the 3-4 shift valve 70 to the first brake B1, and includes a spool 81 having three lands and It has a spring 82 that presses the spool 81 in one direction (upward in the drawing). An oil passage 112, which is branched from the above-mentioned oil passage 108 on the downstream side of the strainer 106, is connected to the control port 83 at the end opposite to the end where the spring 82 is arranged. Orifice 1
13 and a normally open type solenoid valve (tentatively, a fourth solenoid valve) 92 are provided. Therefore, when the fourth solenoid valve 92 is ON, the line pressure PL acts on the control port 83 to lower the spool 81 against the elastic force of the spring 82 as shown on the right side of the drawing, and conversely when it is OFF. The pressure is discharged from the control port 83, and the spool 81 is pushed up to the position shown on the left side of the drawing.

This B1 control valve 80 has 3
-4 The first D port 84 connected to the brake port 76 of the shift valve 70 is formed, and the first brake B1 is connected to the brake port 86 that selectively communicates with the first D port 84 and the drain port 85. Has been done. An accumulator 114 is attached to the first brake B1. Further, the B1 control valve 80 is formed with a second D port 87 connected to the clutch port 62 of the 2-3 shift valve 50 described above, and a clutch port 88 which is connected to or disconnected from the second D port 87 is formed. The second clutch C2 is directly connected without an orifice.

The R port 26 is connected to the third clutch C3 and the R port 40 of the 1-2 shift valve 30 so that the reverse speed is set when the R range is selected by the manual valve 20. Has been done. An accumulator 115 is attached to the third clutch C3.

In the above-described automatic transmission, frictional engagement devices such as clutches and brakes are engaged as shown in FIG. 6 to set each of the four forward speeds and one reverse speed. In FIG. 6, the circle indicates engagement, the circle indicates engagement during engine braking, and the triangle indicates that the second clutch C2 may be engaged, and the blank indicates the released state. Shown respectively.

In the above-described automatic transmission, when the neutral state is shifted to the forward traveling state, that is, when the manual valve 20 is switched from the N range position to the D range position, the first speed is first set after setting the third speed. The so-called squat control that sets the speed is performed. As is known from the operation table of FIG. 6, the control is performed by engaging the first clutch C1 and the second clutch C2 almost at the same time and then the second clutch C.
This is done by releasing the second, but as described above, the second
Since a clutch equipped with an oil drain mechanism such as a check ball is used as the clutch C2, if the amount of pressure oil remaining in the hydraulic chamber greatly differs from the amount of residual oil in the first clutch C1, the inconvenience described below will occur. Therefore, in the above apparatus, the supply speed of the pressure oil to the second clutch C2 is controlled as described below.

First, the residual oil amount of the second clutch C2 is determined according to the flow charts shown in FIGS. In the flowchart shown in FIG. 7, it is determined in step 1 whether or not the second clutch C2 is switched from the engaged state to the released state, and if it is switched to the released state, the flag FL is set to "1" in step 2. After setting, in step 3, the maximum value QMAX is adopted as the residual oil amount Q. Next, at step 4, it is judged whether or not the second clutch C2 is switched to the engaged state, and if it is engaged, that is, if the judgment result is "yes", the routine proceeds to step 5 to reset the flag FL to zero. .. Therefore, the flag FL indicates that the residual oil amount needs to be calculated when the second clutch C2 is switched from the engaged state to the released state.

If the result of the determination in step 1 is "no", the process immediately proceeds to step 4, and if the result of the determination in step 4 is "no", the control in FIG. 7 ends.

The flowchart shown in FIG. 8 shows a predetermined time T0.
A control routine for obtaining the residual oil amount by interrupting each is shown. In step 11, it is judged whether or not the above-mentioned flag FL is "1", that is, whether or not the second clutch C2 is released, and the judgment result If is "No", the control process is returned, and if "Yes", go to Step 12 to calculate the residual oil amount Q. The second clutch C2 is provided with an oil draining mechanism such as a check ball, and when it is rotated in a released state, pressure oil is discharged and air is sucked. The amount of discharge ΔQ per unit time at that time is substantially determined by the opening area of the oil drainage mechanism, its radius of rotation, the innermost diameter of the hydraulic chamber of the second clutch C2, the flow coefficient determined by the shape, and the rotational angular velocity. Since the parameters other than the rotational angular velocity are constants determined by the structure of the second clutch C2, the discharge amount ΔQ per unit time can be finally obtained as a function of the rotational angular velocity of the second clutch C2. Therefore, in step 12, if the elapsed time from the time when the second clutch C2 is released is T, it can be obtained by the following equation: Q = Q-ΔQ × T.

In step 13, it is judged whether or not the value obtained by the above equation is 0 or less. If the value is greater than 0, the control process returns, and if it is 0 or less, the process proceeds to step 14 and the flag is set. While resetting FL to zero,
In step 15, the residual oil amount Q is set to 0.

Since the amount of residual oil in the hydraulic chamber of the second clutch C2 decreases with the passage of time, when the approximate control is performed, the calculation of the residual oil amount in step 12 is replaced with the passage of time. However, the residual oil amount Q may be estimated based on the elapsed time.

FIG. 9 is a flow chart showing an example of squat control performed based on the second clutch C2 obtained as described above. That is, when the shift from the N range to the D range is determined in step 21, it is determined in step 22 whether or not the condition for executing the squat control is satisfied (squart on). Squat control is
This is because the oil temperature is set to a predetermined temperature, the brake signal is not input, and the like.

If the squat control execution condition is satisfied, the flag FQ is set to "1" in step 23. By setting this flag FQ to "1",
This indicates that the control for increasing the speed of supplying the pressure oil to the second clutch C2 should be executed. In the following step 24, the squat control execution command flag FS is set to "1".
Then, in step 25, a timer TA is set. This timer TA indicates the duration of the control for increasing the pressure oil supply speed to the second clutch C2, and is set to a length based on the residual oil amount Q obtained by the control shown in FIG. It Specifically, the smaller the residual oil amount Q is, the longer it is set, and this may be calculated whenever necessary, or it may be stored as a map and the residual oil amount Q may be stored.
It is also possible to read out a value according to. At step 26, another timer TB is set. This timer TB determines the duration of squat control,
In this embodiment, a time slightly longer than the time required to set the third speed is adopted.

Then, at step 27, the fourth solenoid valve 92 shown in FIG. 5 is turned on. When the fourth solenoid valve 92 is turned on, the line pressure PL acts on the control port 83 of the B1 control valve 80, so that the spool 81 is lowered to the position shown in the right half of FIG. The clutch port 88 communicates. After turning on the fourth solenoid valve 92, an instruction signal for setting the third speed is output in step 28.
Specifically, it outputs a signal that turns off the first and second solenoid valves 90 and 91.

When the second solenoid valve 91 is OFF, the pressure is discharged from the control port 73 of the 3-4 shift valve 70 and the spool 71 is pushed up to the position shown in the left half of FIG. D port 23
The line pressure PL output from is supplied to the first clutch C1 via the second D port 75 and the clutch port 79, and this is engaged. When the first solenoid valve 90 is turned off, the pressure is discharged from the control port 54 of the 2-3 shift valve 50, and the spool 51 is pushed up to the position shown in the left half of FIG. The hydraulic pressure output from the D port 23 passes through the third D port 57, the clutch port 67, and the orifice 116 of the 2-3 shift valve 50 to the second clutch C.
Act on 2. At the same time, the fourth solenoid valve 9
2 is turned on and the spool 81 of the B1 control valve 80 is pushed down to the position shown in the right half of FIG.
8 is in communication with the second of the B1 control valve 80
Since the D port 87 is connected to the clutch port 67 of the 2-3 shift valve 50, the second clutch C2 has B1
Pressure oil is supplied from the control valve 80 bypassing the orifice 116. That is, the second clutch C
The pressure oil is supplied to 2 from both the oil passage through the orifice 116 and the oil passage bypassing the orifice 116, so that the supply speed is increased.

The judgment result of step 21 is "no".
If, and if the result of the determination in step 22 is "no", the process proceeds to the next step 29 without performing steps 23 to 28. In this step 29, flag F
Whether or not Q is "1", that is, whether or not the squat control is being executed is determined. If the squat control is being executed, it is determined whether or not the time TA set in the step 25 in step 30 has elapsed. to decide. If this time TA has elapsed, it means that the air has been expelled from the hydraulic chamber of the second clutch C2 and the pressure oil has been filled to the same extent as the hydraulic chamber of the first clutch C1.
At, the fourth solenoid valve 92 is turned off. As a result, the spool 81 of the B1 control valve 80 is pushed up to the position shown in the left half of FIG. 5, so that the pressure oil supply to the second clutch C2 via the B1 control valve 80 is stopped, and the second clutch C2 is stopped. The pressure oil supply rate becomes slow. The supply speed is the first clutch C1.
Is almost equal to the supply speed of pressure oil to. Then, in step 32, the flag FQ is reset to zero.

The judgment result of step 29 is "No".
If so, the process proceeds to step 33 without executing steps 30 to 32, and if the determination result of step 30 is "no", then steps 31 and 3 are performed.
2 is not performed and the process proceeds to step 33.

Steps 33 to 36 are a control process for ending the squat control. First, at step 33, it is judged whether or not the squat control execution command flag FS is "1", and the squat control is executed. If the flag FS is "1", it is determined in step 34 whether the squat control execution time TB has elapsed. If the determination result is "yes", the squat control execution command flag FS is reset to zero in step 35. If the determination result of step 33 is "NO", the process proceeds to step 37 without executing steps 34 to 36. If the determination result of step 34 is "NO", steps 35 and 36 are executed. Is not performed and the process proceeds to step 37.

In step 37, it is judged whether or not the squat control execution condition is satisfied. When the squat control execution condition is satisfied, that is, when the determination result of step 37 is “No”, the control is ended, and when the squat control execution condition is not satisfied, that is, when the determination result is “yes”. Turns off the fourth solenoid valve 92 in step 38, and outputs an instruction signal for setting the first speed in step 39. Further, in step 40, the flag FQ is reset to zero, and in step 41, the squat control execution command flag FS is reset to zero.

A time chart showing the operating state of the rapid supply of the pressure oil to the second clutch C2, the change of the output shaft torque, and the change of the oil pressures of the first and second clutches C1 and C2 when the above control is performed. It is as shown in FIG. t0
When the shift from the N range to the D range is performed at this point,
Almost at the same time, the pressure oil is supplied to the first clutch C1 and the pressure oil is rapidly supplied to the second clutch C2. Therefore, the oil pressure of the first clutch C1 gradually increases as shown by the thin solid line, while the oil pressure of the second clutch C2 shows a high pressure as much as the rapid supply is performed. When the time TA corresponding to the amount of pressure oil remaining in the second clutch C2 before the second clutch C2 is engaged, that is, at the time t1, the rapid supply to the second clutch C2 ends, and accordingly. The hydraulic pressure of the second clutch C2 temporarily drops slightly.

As a result of rapid supply to the second clutch C2 having an oil drainage mechanism, each clutch C
The pistons of C1 and C2 end their strokes almost at the same time at time t2, and thereafter, the supply speed of the pressure oil to the clutches C1 and C2 becomes substantially equal, and both clutches C1 and
The engagement state of C2 becomes almost the same, and the third speed is achieved at time t3. Therefore, the output shaft torque changes smoothly and shift shock does not occur.

On the other hand, in the conventional example in which the pressure oil is not rapidly supplied to the second clutch C2, the second clutch C
As the hydraulic pressure of 2 changes to a low level as shown by the broken line in FIG. 10, only the first clutch C1 is engaged first, and
In the automatic transmission equipped with the gear train shown in, N range to D
By shifting to the range, the first speed is set from the time point t2 to the time point t3, and as a result, the output shaft torque temporarily increases, and this appears as a gear shift shock. Become. In other words, even if the third speed is instructed to perform the squat control, the third speed cannot be substantially set, and the first speed is set first. It should be noted that the gear shift from the third speed to the first speed is omitted in FIG. 10.

Since the above-mentioned embodiment takes squat control as an example, the device of the present invention has a main function of rapidly supplying pressure oil in accordance with the amount of residual oil. Therefore, the present invention can be applied to gear shifts other than the squat control. For example, in the case of an automatic transmission having a gear train shown in FIG. 3, an upshift from the second gear to the third gear is performed. Applicable in case. In that case, the delay in engagement of the second clutch C2 is corrected, so that the feeling of delay in shifting is avoided.

Of course, the automatic transmission to which the present invention is applied is not limited to the one provided with the gear train shown in FIG. 3 and the hydraulic circuits shown in FIGS. 4 and 5.

Further, in the present invention, the means for adjusting the pressure oil supply rate is not limited to the orifice and the B1 control valve bypassing the orifice shown in the above-mentioned embodiment, and means of other constitution may be used as required. Can be adopted, and in that case, the supply rate may be changed in three or more steps.

In the above embodiment, the supply speed of the pressure oil to the clutch having the oil discharge mechanism is adjusted, but in the present invention, another friction engagement device to be engaged at the same time with this type of clutch. You may comprise so that the supply speed of the pressure oil with respect to may be adjusted.

[0052]

As is apparent from the above description, according to the present invention, the pressure oil supply speed is changed according to the residual oil amount of the friction engagement device provided with an oil drainage mechanism such as a check ball. By keeping the oil supply time constant, it is possible to eliminate shift shock, delay in gear shift response, and the like.

[Brief description of drawings]

FIG. 1 is a block diagram showing a basic configuration of the invention described in claim 1.

FIG. 2 is a block diagram showing a basic configuration of the invention described in claim 2.

FIG. 3 is a block diagram schematically showing an embodiment of the present invention.

FIG. 4 is a hydraulic circuit diagram showing a part of a hydraulic circuit in the embodiment.

FIG. 5 is a hydraulic circuit diagram showing another portion of the hydraulic circuit in the embodiment.

FIG. 6 is an engagement operation table of the friction engagement device.

FIG. 7 is a flowchart for determining the necessity of calculation of a residual oil amount of the second clutch.

FIG. 8 is a flowchart for calculating a residual oil amount of the second clutch.

FIG. 9 is a flowchart for controlling the rapid supply of pressure oil to the second clutch during squat control.

FIG. 10 is a time chart showing changes in the rapid supply operation state and output torque, and changes in the hydraulic pressures of the first and second clutches.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Hydraulic chamber 2 Oil discharge mechanism 3 Friction engagement device 4 Residual oil amount determination means 5 Supply speed adjustment means 6 Friction engagement device A Automatic transmission

Claims (2)

[Claims] 1. A hydraulic control device for an automatic transmission having a friction engagement device having an oil discharge mechanism for promoting discharge of pressure oil from a hydraulic chamber, wherein the friction engagement device before engagement of the friction engagement device. And a supply speed adjusting means for changing the supply speed of the pressure oil to the friction engagement device according to the residual oil amount. Hydraulic control device for automatic transmission. 2. A predetermined forward speed of the second speed or higher is engaged with at least two friction engagement devices including a friction engagement device provided with an oil discharge mechanism for promoting discharge of pressure oil from the hydraulic chamber. And setting the first speed by engaging any one of those friction engagement devices, and setting the predetermined forward gear when shifting from the neutral state to the forward traveling state. In a hydraulic control device for an automatic transmission that sets a first speed, a residual oil amount determination means for determining the amount of oil remaining in the friction engagement device before engagement of the friction engagement device including the oil discharge mechanism When,
And a supply speed adjusting means for changing a supply speed of the pressure oil to any one of at least two friction engagement devices to be engaged to set the predetermined forward speed according to the residual oil amount. A characteristic hydraulic control device for automatic transmissions.