JPH0526063B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an improvement in a speed change control device for an automatic transmission for a vehicle.

[Conventional technology]

A gear transmission mechanism and a plurality of frictional engagement devices are provided, and engagement of the frictional engagement devices is selectively switched by operating a hydraulic control device, and any one of the plurality of gears is set. A shift control device for a shift control device for an automatic transmission for a vehicle configured to achieve the above-mentioned problems is already widely known.

For such automatic transmissions, various techniques have been developed in order to reduce the shift shock (for example, Japanese Patent Application Laid-Open No. 58-30558). Under these circumstances, it is generally known that an accumulator is disposed in an oil path to the frictional engagement device in order to maintain the supplied hydraulic pressure at a substantially constant level when the frictional engagement device engages.

This accumulator prevents the hydraulic pressure acting on the friction engagement device from suddenly increasing temporarily by providing a type of oil reservoir in the oil path when new hydraulic pressure is supplied to the friction engagement device. This is what I did.

Generally, from the viewpoint of transmission characteristics, in order to reduce the temporal change rate of the output shaft torque as much as possible, it is recommended to keep the supplied hydraulic pressure constant or gradually decrease when the frictional engagement device engages. is often preferred. For example, if the frictional engagement device is a clutch,
Rotation begins as soon as engagement begins, so
Since centrifugal oil pressure is generated and this centrifugal oil pressure is added to the actual supplied oil pressure, it is preferable to gradually reduce the supplied oil pressure by that amount.

However, there is a problem in that the hydraulic characteristics obtained by the accumulator have a very low degree of freedom due to the structure of the accumulator. For example, when considering a power-on upshift, as the accumulator piston moves, the oil pressure inevitably increases by an amount corresponding to the increase in the spring load attached to the accumulator piston. In order to reduce this rate of increase as much as possible, an attempt is made to reduce the spring constant of the spring attached to the accumulator piston, which is necessary at the beginning and end of the movement of the accumulator piston. In many cases, it is not possible to arbitrarily lower the spring constant due to constraints such as the load applied, the dimensions of the accumulator, and the properties of the spring material.

Furthermore, since the accumulator maintains the oil pressure constant by forming a so-called oil reservoir, it generally requires a considerable amount of space, which is an obstacle to downsizing automatic transmissions.

In view of the fact that it is difficult to reduce the shift shock of the friction engagement device only by the pressure regulating action of the accumulator, a technique has been disclosed that detects the final stage of the shift and reduces the engagement hydraulic pressure at this stage ( JP-A-58-225226, USP367412, etc.). In Japanese Patent Laid-Open No. 58-225226, the final timing of the frictional engagement is detected based on the relative speed between the driving side member and the driven side member of the frictional engagement device. By adopting such a method, it is possible to effectively reduce the shift shock that occurs when the friction coefficient of the friction engagement device changes from "dynamic" to "static".

[Problem to be solved by the invention]

However, as mentioned above, there is a problem in that in order to lower the engagement hydraulic pressure at the final stage of the shift, the hardware system of the conventional hydraulic control device must be considerably modified.

For example, in USP 367,412, an extremely complicated and special engagement control valve or time control valve is introduced in order to control the reduction of the engagement oil pressure at the end of the shift. Further, in the above-mentioned Japanese Patent Application Laid-open No. 58-225226, an electromagnetic proportional valve is used to reduce the engagement oil pressure, but this type of equipment is relatively expensive, leading to an increase in the cost of the entire device.

[Purpose of the invention]

The present invention has been made in view of such conventional problems, and can be achieved without making any changes to the conventional hydraulic control device or using expensive equipment such as electromagnetic proportional valves. It is an object of the present invention to provide a shift control device for an automatic transmission for a vehicle, which has a smaller shift shock and can provide a good shift feeling.

[Means for solving problems]

The first invention comprises a gear transmission mechanism and a plurality of frictional engagement devices, and engages the frictional engagement devices by switching a shift valve in a hydraulic control device by operating an electromagnetic solenoid valve. As shown in FIG. a means for detecting the time;
From the predetermined time, the shift valve involved in the gear shift is temporarily returned to the previous gear position at least once by operating the electromagnetic solenoid valve;
The above object is achieved by including means for temporarily lowering the engagement pressure of the frictional engagement device in the latter half of the gear shift.

Further, the second invention includes a gear transmission mechanism and a plurality of frictional engagement devices, and the frictional engagement devices are controlled by switching a shift valve in a hydraulic control device by operating an electromagnetic solenoid valve. In a shift control device for a vehicle automatic transmission configured to selectively switch engagement to achieve one of a plurality of gears, as shown in FIG. 1B, during a shift means for detecting a predetermined timing in the shift, and a means for temporarily returning the shift valve involved in the gear shift from the predetermined timing to the previous gear side at least once by operating the electromagnetic solenoid valve to reduce the friction in the latter half of the gear shift. means for temporarily lowering the engagement pressure of the engagement device; failure determination means for determining whether or not the means for detecting a predetermined timing during the gear shift has failed; By providing a means for temporarily stopping the shift valve involved from returning to the previous gear side at least once, the above object can be achieved and a so-called fail-safe can be taken into account.

[Effect]

In the first invention, first, a predetermined time during a shift is detected, and from this predetermined time, the shift valve involved in the shift is temporarily returned to the previous gear side at least once. Without making any particular changes to the hardware system of the device, it is possible to minimize the hydraulic force acting on the frictional engagement device during gear shifting (this hydraulic force corresponds to the torque transmission force in the frictional engagement device) and the shift shock. The more control you have, the more you can maintain a good shifting feel.

In addition, in the second invention, the effect of the first invention is obtained, and in the event that the means for detecting the predetermined timing fails, the shift valve involved in the gear shift is temporarily operated at least once. Since the system stops returning to the previous gear side,
By controlling the supply oil pressure, it becomes possible to prevent the occurrence of such inconvenience as the shift shock increasing.

In the first and second inventions, a preferred embodiment is that the predetermined timing is determined depending on at least one of an engine rotation speed and a rotation speed of a rotating member of the automatic transmission.

Preferably, the predetermined timing is determined depending on a hydraulic pressure value supplied to the frictional engagement device.

Preferably, the predetermined time is a first time after the oil pressure supplied to the frictional engagement device reaches a predetermined value.
This is supposed to be after the specified time.

Preferably, the predetermined timing is determined depending on the position of a piston of an accumulator arranged in an oil path to the frictional engagement device.

Preferably, the predetermined time is a second predetermined time after a piston of an accumulator disposed in an oil path to the frictional engagement device reaches a predetermined position.

Preferably, the predetermined time is determined by a timer from either a shift determination or a shift command.

The adoption timing of this predetermined timing differs depending on the type of speed change. Further, each of the above-mentioned detection means has advantages and disadvantages in terms of cost, reliability against failure, detection accuracy, ease of installation, and the like. Therefore, an appropriate one may be selected and adopted depending on the vehicle in which it is mounted.

Further, in a preferred embodiment, the way the shift valve is returned depends on the engine load, the type of shift, the vehicle speed, and the engine rotational speed after returning the shift valve.
It is determined depending on at least one of the rotational speeds of the rotating members of the automatic transmission after the shift valve is returned. By doing this, the way the shift valve is returned can be made more appropriate.

Furthermore, a preferred embodiment is to set a return permission section in which the shift valve is returned, and to perform the shift valve return operation only within this section. Furthermore, the return permission section is set from after a third specified time has elapsed to when a fourth specified time has elapsed, counting from either the shift determination or the shift command. By doing so, it is possible to prevent the shift valve of the supply hydraulic pressure from being returned at a time when it should not occur due to erroneous detection by a sensor or the like.

On the other hand, in a preferred embodiment of the second invention, the failure determination means determines the failure based on whether or not the predetermined time is detected within a fifth prescribed time from either the gear change determination or the gear change command. It is something that is considered a thing. Alternatively, a malfunction is determined based on whether the output values of the two detection means provided at the predetermined times are within a predetermined error range. By employing such a failure determination means, it becomes possible to correctly grasp whether or not the predetermined time is accurately detected.

〔Example〕

Embodiments of the present invention will be described in detail below based on the drawings.

First, FIG. 2 shows an overall outline of a vehicle automatic transmission to which this embodiment is applied.

This automatic transmission includes, as its transmission section, a torque converter 20, an overdrive mechanism 40, and an underdrive mechanism 60 with three forward speeds and one reverse speed.

The torque converter 20 is of a known type and includes a pump 21, a turbine 22, a stator 23, and a lock-up clutch 24. pump 2
1 is connected to the crankshaft 10 of the engine 1,
The turbine 22 is connected to a carrier 41 of a planetary gear system in an overdrive mechanism 40 via a turbine shaft 22A.

In the overdrive mechanism 40, a planetary pinion 42 rotatably supported by the carrier 41 meshes with a sun gear 43 and a ring gear 44. Further, a clutch C ₀ and a one-way clutch F ₀ are provided between the sun gear 43 and the carrier 41, and a brake B ₀ is provided between the sun gear 43 and the housing Hu.

The underdrive mechanism 60 is provided with two rows of planetary gears, one on the front side and the other on the rear side. This planetary gear device consists of a common sun gear 61, ring gears 62, 63, planetary pinions 64, 65, and carriers 66, 67, respectively.

Ring gear 44 of overdrive mechanism 40
is connected to the ring gear 62 via a clutch _C1 . Further, a clutch _C2 is provided between the ring gear 44 and the sun gear 61. Further, the carrier 66 is connected to the ring gear 63, and the carrier 66 and the ring gear 63 are connected to an output shaft 70.

On the other hand, a brake B ₃ and a one-way clutch F ₂ are provided between the carrier 67 and the housing Hu, and the sun gear 61 and the housing
A brake _B2 is provided between the sun gear 61 and the housing Hu via a one-way clutch _F1 , and a brake _B1 is provided between the sun gear 61 and the housing Hu.

This automatic transmission is equipped with the transmission section as described above, and includes a throttle sensor 80 that detects the throttle opening that reflects the load condition of the engine 1, and a vehicle speed sensor that detects the vehicle speed (rotational speed of the output shaft 70). A computer (ECU) 84 receives signals such as the C ₀ drum rotation speed 99 that detects the rotation speed of the C ₀ drum (sensor) 82 and the C 0 drum.
The electromagnetic solenoid valves S ₁ to _{S 2} (for shift valves) and SL (for lock-up clutch) in the hydraulic control circuit 86 are driven and controlled according to a preset shift map, as shown in FIG. A combination of engagements of various clutches, brakes, etc. is performed to perform speed change control. In FIG. 3, the ◯ marks indicate the engaged state, and the ◎ marks indicate that the engaged state occurs only during driving.

As shown in FIG. 4, the electromagnetic solenoid valve _S1 controls the 2-3 shift valve, and the electromagnetic solenoid valve _S2 controls the 1-2 shift valve and the 3-4 shift valve. And 1-
The shift valves 2 and 2-3 control the shift of the underdrive mechanism 60 from the first gear to the third gear, and the shift valve 3-4 controls the shift of the overdrive mechanism 40 (the third gear). (speed change between the gear position and the fourth gear position) is performed. The electromagnetic solenoid valve SL also controls a lock-up clutch 24 in the torque converter 20 via a lock-up relay valve.

In Fig. 2, reference numeral 90 is a shift position sensor that detects the positions of N (neutral), D (drive), R (reverse), etc. operated by the driver, and 92 is a pattern select switch. 94 indicates a water temperature sensor that detects the engine cooling water temperature, and 96, 9
Reference numeral 8 indicates a brake switch that detects the operation of the foot brake and hand brake.

Next, the control flow in this embodiment device is shown in FIG. Here, for the sake of simplicity, we will discuss a 1→2 upshift.

First, in steps 202 to 204, the throttle opening θ, the output shaft rotation speed N ₀ of the automatic transmission (corresponding to the vehicle speed), and the drum rotation speed N _CO of the clutch C ₀ are monitored.

F in step 206 is a flag for controlling the flow. Since F is initially reset to zero, the process advances to step 208. In step 208, it is determined whether or not a shift decision has been made. If there is no particular gear change judgment, the system will be reset as is. When a shift decision is made, the process proceeds to step 210, where the shift output for upshifting from the first gear to the second gear, that is, the electromagnetic solenoid valve _S2 for switching the 1-2 shift valve is turned on. Next, in step 212, a timer value _T1 is searched in accordance with the throttle opening θ and the type of gear change. This timer value _T1 corresponds to the third specified time in claim 17, and the supply hydraulic pressure is not controlled until at least the timer value _T1 after the shift command is issued. This eliminates the inconvenience caused when a "predetermined period" is mistakenly detected during this period.

Shift command at step 214 (step 210)
Only when it is determined that the elapsed time t ₁ has become greater than the timer value T ₁ does the process proceed to step 216, where a constant N ₁ is searched in accordance with the throttle opening θ and the type of gear change. This constant _N1 is a correction constant term for detecting the "predetermined time".

“Predetermined time” is step 218 in this example.
judged by. That is, when it is determined that the drum rotational speed _NCO of the clutch _C0 has become smaller than the value obtained by multiplying the output shaft rotational speed _N0 by the gear ratio _iB of the gear stage and adding the constant _N1 , Detection is now performed at a "predetermined time." After this detection has been performed, in steps 220, 222, and 224, the timer values T ₂ and T ₃ and the count constant K ₀ are changed to the throttle opening θ and the type of shift (in this case, 1→2).
Shift) and step
At 226 timer t ₂ is started and further steps
At 228, the electromagnetic solenoid valve _S2 is turned off. As a result, the 1-2 shift valve is temporarily returned to the state of the first gear, and the hydraulic pressure that has started to be supplied to the brake _B2 is drained, and as a result, the hydraulic pressure supplied to the brake _B2 is reduced. descend.

An example of the map for T ₁ , T ₂ , T ₃ and N ₁ , K ₀ is shown in FIG. 6.

Step 230 turns off this electromagnetic solenoid valve _S2 .
This continues for the timer value _T2 from the time of activation in step 226, and when step 232 is reached, the electromagnetic solenoid valve _S2 is turned ON again, and the operation is continued in step 234.
After momentarily resetting the timer _t2 to zero, the process proceeds to step 236. In step 236, the electromagnetic solenoid valve _S2 in step 232 is kept ON for the timer value _T3 , and when the timer value _T3 has elapsed, the electromagnetic solenoid valve _S2 is turned off again (step 238), and then in step 240. and increments counter K.

In step 242, it is determined whether the counter K has become larger than the counter constant _K0 .
Unless this is true, steps 226 to 240 are repeated, and the number of repetitions is counted each time in step 240. At the end of this count, in step 244, the final state of the electromagnetic solenoid valve _S2 is
The ON operation is performed, and in step 246, the flag F, counter K, timers _t1 , _t2, etc. are all set to zero and then reset.

According to this embodiment, the temporal change rate of the supplied hydraulic pressure is adjusted by switching the 1-2 shift valve (reciprocating between the first gear and the second gear). As for the hardware system of the control device, it is possible to use the same one as the conventional one.

In addition, when switching the 1-2 shift valve, the maintenance time for the 1st and 2nd gears is set depending on the throttle opening θ and the type of gear change, so the maintenance time can be adjusted to match the driving conditions. It can be changed and set appropriately to the rate of change over time.

In addition, the time for changing and setting the temporal rate of change (in this embodiment, this is managed by the count constant _K0 ) is also determined according to the throttle opening θ and the type of gear change, so that it can be adjusted according to the driving condition. The relevant changes and settings can be made for a limited time.

Furthermore, in the above embodiment, since the change permission section is defined by the count constant _K0 after the timer _T1 has elapsed since the shift command was issued, at least the timer value after the shift command is issued.
Even if the "predetermined time" is erroneously detected before _T1 has elapsed, erroneous control will not be executed because of this.

According to the above embodiment, when setting the "predetermined timing", the output shaft rotational speed _N0 of the automatic transmission is actually monitored, multiplied by the gear ratio _iB , and then the throttle opening θ is and the value with correction by constant N ₁ determined according to the type of gear shifting and clutch C ₀
Since the determination is made by comparing the drum rotational speed _NCO of

FIG. 7 shows an embodiment of the second invention.

To explain the characteristic features of the first embodiment, if it is determined in step 250 that the flag F is zero, the process proceeds to step 252, where it is determined whether or not to change gears. At 254, a speed change command, that is, an ON command for the electromagnetic solenoid valve _S2 is issued. Steps 256 to 264 are the same as the flow described above. The OFF command for electromagnetic solenoid valve _S2 in step 264 is executed in step 266.
This is maintained until the condition of whether the current _C0 drum rotational speed _NCOi is greater than the value obtained by subtracting the constant △N from the previous _C0 drum rotational speed _NCOi-1 is satisfied ( Step 268 or Step 270).

Meanwhile, in step 272, C ₀ drum rotation speed
When _NCO becomes smaller than the output shaft rotational speed _N0 multiplied by the gear ratio _iB , the _C0 drum rotational speed or output shaft rotation is the basis for detecting the "predetermined time" in step 274. It is determined whether the rotation sensor system at speed N ₀ is out of order. In this failure detection, for example, it is necessary to check whether the conditions for detecting the "predetermined time" in step 262 are satisfied within a predetermined time, or whether the difference between the output values of two sensor systems is predetermined. Judgment is made based on whether or not it falls within the specified error range.
If it is determined that there is a failure based on this judgment, control of the supplied hydraulic pressure is stopped, and in step 276, the electromagnetic solenoid valve _S2 is turned ON and reset.
Also, in step 278, the throttle opening θ
It is determined whether or not is larger than a predetermined value θ ₀ .
When it is determined that the throttle opening θ is smaller than the predetermined opening θ ₀ , there is little need to particularly control the supply hydraulic pressure, so the control is also stopped and the step
It is reset after turning on the electromagnetic solenoid valve _S2 at 276.

In this embodiment, the temporal change rate of the supplied oil pressure is controlled so that the temporal change rate of the _C0 drum rotational speed becomes a constant negative value. Also, in this example,
The time rate of change of the supplied hydraulic pressure is changed depending on the rotational speed _NCO of the rotating member in the automatic transmission after the change.
The change/setting is completed depending on the _C0 drum rotational speed _NCO . Therefore, it is possible to perform control in accordance with the actual state of the automatic transmission.

FIG. 8 shows a transient characteristic diagram when shifting from the first gear to the second gear in the first embodiment. Time a
makes a gear change judgment and gives a gear change command. i.e. solenoid S ₂
Turn on. As a result, the hydraulic pressure of the brake B ₀ starts to be supplied, and from point b, each rotating member of the automatic transmission starts changing the rotation speed for gear shifting, and the C ₀ drum rotation speed N _CO starts to decrease. In the figure, the solid line shows the conventional characteristics, and the broken line shows the transient characteristics of the present invention. Since the accumulator cannot be set to reduce the oil pressure as the piston moves, the output shaft torque in the inertia phase increases with time.
Furthermore, since the coefficient of friction generally increases as the motor rotates and stops, the rate of increase further increases at the end of rotation (point d), deteriorating the speed change characteristics (point X in the figure).
In the first and second embodiments, by turning the electromagnetic solenoid valve S ₂ ON and OFF from point c, the oil pressure can be lowered arbitrarily, so it is possible to obtain good shifting characteristics as shown by the broken line. It becomes possible.
Note that the energy absorption rate of the frictional engagement device is maximum at the beginning of the inertia phase and becomes zero at the end of the inertia phase. Therefore, even if the oil pressure is lowered at a relatively late stage as in this embodiment, an increase in the amount of absorption does not become a problem. Furthermore, since the accumulator requires a certain amount of time to operate, it generally requires a large storage space in an automatic transmission, but according to this embodiment, the accumulator piston that has moved halfway is returned to its original position, and then it is moved again. Since it is possible to use the accumulator by moving it in the first direction, it is also possible to significantly reduce the volume of the accumulator.

Note that the following examples are available as means for controlling line oil pressure and accumulator back pressure as changing/setting means. This will be explained below.

FIG. 9 shows the main parts of the hydraulic control device.

In the figure, S _D is the electromagnetic proportional valve, 102 is the pump, 103 is the primary regulator valve, 104 is the 1-2 shift valve, S ₂ is the electromagnetic solenoid valve, and 106 is the electromagnetic solenoid valve operated by the driver. manual valve, 107 is the brake
The accumulators used to control the transient characteristics when hydraulic pressure is supplied to and discharged from _B2 are shown.

The electromagnetic proportional valve S _D is itself well known and is composed of spools 109, 110, a coil 108, a spring 113, a plunger 111, and the like. The spool 110 and the plunger 111 are meshed so that they can move integrally in the axial direction. coil 1
08 exerts a downward force F _C in the figure on the plunger 111 and therefore on the spool 110 in accordance with the load current I _P from the ECU 84 . On the other hand, spring 113
exerts a force F _S on spool 110 in the opposite direction. Further, the discharge pressure of the pump 102 acts on the port 114. The hydraulic pressure acting on ports 115 and 116 is Pθ, land 109 of spool 109
If the face area of A is _A1 , Pθ can be found by equation (1).

Pθ=(F _S −F _C )/A ₁ (1) Therefore, by controlling the force F _C generated by the coil 108 in the downward direction in the figure, the port 11
5 can be controlled to any value between O and F _S /A ₁ . Conventionally, this oil pressure Pθ corresponds to the throttle pressure generated by a throttle valve whose spool can be mechanically driven via a cam in response to the throttle opening.
Port 1 is used as a hydraulic pressure for controlling the line hydraulic pressure generated by the primary regulator valve 103.
19.

In the primary regulator valve 103, the line oil pressure PL is generated according to the value of the control oil pressure Pθ by the same operation as in the conventional art. As a result, by controlling the load current I _P to the coil 108 depending on the intake temperature etc. according to the command from the ECU 84, the line oil pressure PL reflecting the intake temperature can be arbitrarily controlled. Note that the pressure regulation relational expression for the primary regulator valve 103 is shown in equation (2).

PL={F _S2 + (B ₂ − B ₃ )P _R +B ₂ Pθ}/B ₁ …(2) Here, F _S2 is the acting force of the spring 120, B ₁
~ _B3 is land 121 of spools 123 and 124,
The face area is 122,125. Also, P _R
is the line oil pressure applied to lands 122 and 125 when manual valve 106 is in reverse range.

Next, the relationship between the frictional engagement devices will be explained. Here, brake _B2 will be explained as a representative example.

The signal pressure of the electromagnetic solenoid valve _S2 acts on the port 126 of the 1-2 shift valve 104. Therefore, the spool 127 of the 1-2 shift valve 104 is in the ON- position of the electromagnetic solenoid valve _S2 .
It slides from right to left in the figure depending on the OFF status. The sliding to the right is due to the force F _S3 of the spring 128. At this time, ports 133 and 129 of the 1-2 shift valve 104 are connected. Line oil pressure from port 130 of manual valve 106 is connected to port 129.
PL is designed to work in the D (drive) range. That is, at the D range selection position of the spool 131 of the manual valve 106, the ports 130,1
29,133 are connected. On the other hand, port 133 is connected to oil passage 135 and check valve 1.
34 to the brake _B2 . Therefore, in the D range, the electromagnetic solenoid valve _S2
Line oil pressure PL to brake B ₂ by ON-OFF
is supplied and discharged.

An accumulator 107 is connected to the oil passage 135, and controls the transient oil pressure level when the line oil pressure PL is supplied to and discharged from the brake _B2 . The hydraulic pressure P _B2 during operation of the accumulator 107 is determined depending on the line hydraulic pressure PL applied as back pressure, as shown by the following equation.

P _B2 = F _S4 + (C ₁ − C ₂ ) PL/C ₁ …(3) Here, F _S4 is the acting force of the spring 136, C ₁ ,
C ₂ is the face area of the two lands of the accumulator piston 137.

From the above equations (1) to (3), by controlling the control oil pressure Pθ by controlling the load current to the electromagnetic proportional valve 101, the oil pressure P _B2 to the brake _B2 reflects the intake temperature, including during transient times. After that, you can control it as you like.

In addition, as mentioned above, in the present invention,
How to detect the "predetermined time" and
How to change the rate of change of supply oil pressure over time
The setting etc. are not limited to the above embodiment.

〔Effect of the invention〕

As explained above, according to the present invention, the excellent effect of being able to maintain better shift characteristics without changing the hardware of the conventional hydraulic control device can be obtained. Further, it is possible to reduce the volume of the accumulator, and it is also possible to achieve the effect that the entire automatic transmission can be downsized.

[Brief explanation of the drawing]

1A and 1B are block diagrams showing the gist of the first and second inventions, and FIG. 2 is a vehicular automatic transmission to which the first embodiment of the hydraulic control device for an automatic transmission according to the invention is applied. Figure 3 is a diagram showing the operating state of the frictional engagement device in the automatic transmission, Figure 4 is a diagram showing the input/output relationship of the control system, and Figure 5 is a diagram showing the overall skeleton diagram of the transmission. , FIG. 6 is a diagram showing an example of a map of various constants, FIG. 7 is a flow chart showing a control routine according to the second embodiment of the present invention, and FIG. FIG. 9 is a speed change transient characteristic diagram qualitatively showing the effects of the present invention.
FIG. 7 is a main hydraulic circuit diagram showing a third embodiment of the present invention. 1...Engine, 20...Torque converter, 40
...Overdrive mechanism, 60...Underdrive mechanism, 84...ECU, 86...Hydraulic control circuit, S ₂
...Solenoid solenoid valve, S _D ...Solenoid proportional valve, 103...
Primary regulator valve, 104...1-2
Shift valve, 107...accumulator.

Claims (1)

[Scope of Claims] 1. A gear transmission mechanism and a plurality of frictional engagement devices, the frictional engagement devices being engaged by switching a shift valve in a hydraulic control device by operating an electromagnetic solenoid valve. In a shift control device for an automatic transmission for a vehicle configured to selectively switch gears to achieve one of a plurality of gears, the gear shift control device for a vehicle automatic transmission comprises: means for detecting a predetermined time during a shift; and detecting the predetermined time. , the shift valve involved in the gear shift is temporarily returned to the previous gear at least once by operating the electromagnetic solenoid valve, and the engagement pressure of the frictional engagement device is temporarily lowered in the latter half of the gear shift. A gear change control device for an automatic transmission for a vehicle, characterized in that it is equipped with means for controlling the transmission. 2. The shift control device for an automatic transmission for a vehicle according to claim 1, wherein the predetermined timing is determined depending on at least one of an engine rotation speed and a rotation speed of a rotating member of the automatic transmission. 3. Claim 1, wherein the predetermined timing is determined depending on a hydraulic pressure value supplied to the frictional engagement device.
A speed change control device for an automatic transmission for a vehicle as described in 1. 4. A shift control device for an automatic transmission for a vehicle according to claim 3, wherein the predetermined time is a first predetermined time after the oil pressure supplied to the frictional engagement device reaches a predetermined value. . 5. The speed change control device for an automatic transmission for a vehicle according to claim 1, wherein the predetermined time is determined depending on the position of a piston of an accumulator arranged in an oil path to the frictional engagement device. 6. The vehicle according to claim 5, wherein the predetermined time is a second predetermined time after a piston of an accumulator disposed in an oil path to the frictional engagement device reaches a predetermined position. Shift control device for automatic transmission. 7. The shift control device for an automatic transmission for a vehicle according to claim 1, wherein the predetermined timing is determined by a timer from either a shift determination or a shift command. 8. The method of returning the shift valve depends on at least one of the following: engine load, type of shift, vehicle speed, engine rotational speed after returning the shift valve, and rotational speed of a rotating member of the automatic transmission after returning the shift valve. A speed change control device for an automatic transmission for a vehicle according to any one of claims 1 to 7, which is determined depending on the following. 9. Claims 1 to 8 set a return permission section in which the shift valve is returned, and the shift valve return operation is performed only within this section.
2. A speed change control device for an automatic transmission for a vehicle according to any one of the items. 10. The vehicular automatic according to claim 9, wherein the return permission section is from after a third specified time has elapsed to when a fourth specified time has elapsed, counting from either the shift determination or the shift command. Shift control device for transmission. 11. The automatic transmission for a vehicle according to claim 10, wherein at least one of the third specified time and the fourth specified time is determined depending on at least one of the engine load, the type of shift, and the vehicle speed. transmission control device. 12 Comprising a gear transmission mechanism and a plurality of frictional engagement devices, the engagement of the frictional engagement devices is selectively switched by switching a shift valve in a hydraulic control device by operating an electromagnetic solenoid valve. , a shift control device for a vehicle automatic transmission configured to achieve one of a plurality of gears, comprising: means for detecting a predetermined time during a shift; and a means for detecting a predetermined time during a shift, and a means for participating in the shift from the predetermined time. Means for temporarily returning the shift valve to the previous gear side at least once by operating the solenoid valve, and temporarily lowering the engagement pressure of the frictional engagement device during the shift; and during the shift. A vehicle for use in a vehicle, comprising: a failure determination means for determining whether or not the means for detecting a predetermined time has failed; and means for canceling the return operation of the shift valve when it is determined that the failure has occurred. Shift control device for automatic transmission. 13. The device according to claim 12, wherein the failure determination means determines the failure based on whether or not the predetermined time is detected within a fifth specified time from either the gear change determination or the gear change command. Shift control device for automatic transmission for vehicles. 14. Claim 12, wherein the failure determination means determines a failure based on whether the output value of the detection means at the predetermined time, which is provided in two systems, is within a predetermined error range. A speed change control device for an automatic transmission for a vehicle as described in 1.