JPH0942434A - Speed change control device of automatic transmission for vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To restrain generation of a speed change shock by holding the lowest value of control pressure supplied to a pressure regulating valve by a previously set setting value higher than the lowest limit value of its variable range within the time interval of transmissions to release a hydraulic frictional engagement device by a control pressure holding means. SOLUTION: A B3 control valve 92 as a pressure regulating valve to directly regulating pressure of a brake B3 provided with no accumulator, it is provided cocentrically with a spool valve element 104 by sandwiching the spool valve element 104 to open and close a passage between oil passages L01, L02 and a spring 106 and stores a plumger 108 a diameter of which is larger than the spool valve element 104 and the spring 106. Additionally, it is furnished with an oil chamber 110 to receive forward range pressure output from a third speed side when a 2-3 shift valve is changed over to the third speed side and an oil chamber 112 provided on a shaft end of the plunger 108 and to receive control pressure from a linear solenoid valve.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a shift control device for an automatic transmission for a vehicle of a type which directly controls an operating hydraulic pressure in a hydraulic friction engagement device by using a pressure regulating valve during a shift period.

[0002]

2. Description of the Related Art A plurality of gear stages are selectively connected to each other or to a fixed member according to a combination of actuations of a plurality of hydraulic friction engagement devices (clutch or brake). There is known an automatic transmission for a vehicle in which the above-mentioned alternative is achieved. In such an automatic transmission, the adjustment is performed to adjust the operating hydraulic pressure in the hydraulic friction engagement device that is engaged to achieve a predetermined gear but is released to achieve another gear. A pressure valve and an electromagnetic valve that outputs a control pressure for controlling the pressure regulating valve are provided, and the operating hydraulic pressure in the hydraulic friction engagement device is directly controlled to a value according to the control pressure during a shift period. There may be a case where a shift control device is provided.

In such a shift control device, instead of the accumulator having a large volume provided in the hydraulic friction engagement device, the working hydraulic pressure (engagement hydraulic pressure) within the shift period is directly controlled by the pressure regulating valve. Therefore, there is an advantage that the automatic transmission is small. For example, JP-A-6-3415
The shift control device described in Japanese Patent No. 25 is that.

[0004]

By the way, there may be a case where a multiple shift is performed by executing another shift determination during the shift achieved by releasing the hydraulic friction engagement device. However, if the control pressure for the pressure regulating valve is set to zero in order to release the hydraulic oil in the hydraulic friction engagement device at the time of the initial shift, the control pressure is again supplied to the pressure regulating valve by executing the multiple shift. At this time, since the flow rate change on the output side of the solenoid valve is large, the response delay of the solenoid valve until the desired control pressure is generated is large. Therefore, for example, when the hydraulic frictional engagement device is for achieving the second speed gear, in a multiple shift in which a 1 → 2 shift is determined during a 2 → 1 shift, 2 → 1
If the control pressure to the solenoid valve is zero during the shift, the responsiveness of the 1 → 2 shift may be deteriorated, which may cause a shift shock.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a hydraulic friction engagement device in which an engagement pressure is directly controlled to release another hydraulic friction engagement device during a gear shift. It is an object of the present invention to provide a shift control device for an automatic transmission for a vehicle, in which the occurrence of a shift shock due to a multiple shift that executes shift determination is suppressed.

[0006]

SUMMARY OF THE INVENTION In order to achieve such an object, the gist of the present invention is that it is engaged to achieve a predetermined gear stage but released to achieve another gear stage. The hydraulic friction engagement device is provided with a pressure regulating valve for regulating the working hydraulic pressure in the hydraulic friction engagement device, and a solenoid valve for outputting a control pressure for controlling the pressure regulation valve. Is a shift control device for an automatic transmission for a vehicle, which directly controls the operating hydraulic pressure of the hydraulic pressure control device to a value according to the control pressure, wherein the pressure regulating valve is used during a shift period in which the hydraulic friction engagement device is released. The control pressure holding means holds the minimum value of the control pressure supplied to the control pressure control device at a preset pressure value that is larger than the lower limit value of the change range by a predetermined value.

[0007]

According to this structure, the minimum value of the control pressure supplied to the pressure regulating valve changes during the shift period in which the hydraulic friction engagement device is released by the control pressure holding means. It is held at a preset set pressure value that is larger than the lower limit value of the range by a predetermined value. Therefore, when a multiple shift that performs another shift is executed during the shift period in which the hydraulic friction engagement device is released, the control pressure is held at the set pressure value in advance, so that when performing the multiple shift, When the control pressure is to be supplied again to the pressure regulating valve in order to reengage the hydraulic friction engagement device, the flow rate change on the output side of the solenoid valve is small, and the solenoid valve until the desired control pressure is generated is generated. Response delay is greatly reduced. Therefore, the occurrence of the shift shock due to the responsiveness of the solenoid valve is preferably eliminated.

[0008]

Another aspect of the present invention is preferably such that the set pressure value held by the control pressure holding means is such that the working hydraulic pressure in the hydraulic friction engagement device is substantially related to the hydraulic friction engagement device. It is a value set in advance so as to have a size immediately before the merge.

Further, preferably, a shift hydraulic pressure control means is provided for controlling an operating hydraulic pressure in the hydraulic friction engagement device when shifting is achieved by releasing the hydraulic friction engagement device. This shift hydraulic pressure control means includes a sweep control means for rapidly reducing the control pressure from a maximum value to a continuous reduction initial value, and then continuously lowering the control pressure at a predetermined reduction rate, and the sweep control means. Control pressure holding means for holding the control pressure at the set pressure value when the continuously lowered control pressure reaches the set pressure value.

Further, preferably, a shift completion determining means for determining whether or not the shift achieved by releasing the hydraulic friction engagement device is completed is provided, and the control pressure holding means is provided with The control pressure is held at the set pressure value until the shift completion determination means determines that the shift is completed.

Further, preferably, engine load detecting means for detecting an engine load of the vehicle represented by, for example, a throttle valve opening degree, and operating oil temperature detecting means for detecting the temperature of the operating oil are provided. The sweep control means determines a continuous decrease initial value and a decrease rate of the control pressure based on the engine load and the hydraulic oil temperature from a relationship stored in advance.

[0012]

DETAILED DESCRIPTION OF THE INVENTION An embodiment of the present invention will be described in detail below with reference to the drawings.

FIG. 1 is a skeleton view showing an example of an automatic transmission for a vehicle which is controlled by a shift control device according to an embodiment of the present invention. In the figure, an output of an engine 10 is input to an automatic transmission 14 via a torque converter 12,
The power is transmitted to drive wheels via a differential gear device and an axle (not shown).

The torque converter 12 is used for the engine 1
Pump impeller 18 connected to crankshaft 16
, A turbine runner 22 connected to the input shaft 20 of the automatic transmission 14, a lock-up clutch 24 directly connecting between the pump impeller 18 and the turbine runner 22, and a one-way clutch 26 that prevents rotation in one direction. And a stator 28 that is in the position.

The automatic transmission 14 includes a first transmission 30 for switching between high and low gears, and a second transmission 32 for switching between a reverse gear and four forward gears. The first transmission 30 includes an HL planetary gear device 34 including a sun gear S0, a ring gear R0, and a planet gear P0 rotatably supported by the carrier K0 and meshed with the sun gear S0 and the ring gear R0, a sun gear S0, and a carrier. The clutch C0 and the one-way clutch F0 are provided between the sun gear S0 and the housing 41, and the brake B0 is provided between the sun gear S0 and the housing 41. The second transmission 32 includes a sun gear S1 and a ring gear R.
1 and a first planetary gear unit 36 rotatably supported by the carrier K1 and comprising a planetary gear P1 meshed with the sun gear S1 and the ring gear R1, and rotatably supported by the sun gear S2, the ring gear R2, and the carrier K2. And a second planetary gear device 38 composed of a planetary gear P2 meshed with the sun gear S2 and the ring gear R2, and rotatably supported by the sun gear S3, the ring gear R3, and the carrier K3, and meshed with the sun gear S3 and the ring gear R3. And a third planetary gear set 40 including a planetary gear P3.

The sun gear S1 and the sun gear S2 are integrally connected to each other, the ring gear R1, the carrier K2 and the carrier K3 are integrally connected, and the carrier K3 is connected to the output shaft 42. Further, a ring gear R2 is integrally connected to the sun gear S3. A clutch C1 is provided between the ring gear R2 and the sun gear S3 and the intermediate shaft 44, and the sun gear S1 and the sun gear S3 are provided.
A clutch C2 is provided between the shaft 2 and the intermediate shaft 44. A band-type brake B1 for stopping rotation of the sun gear S1 and the sun gear S2 is provided on the housing 41.
It is provided in. A one-way clutch F1 is provided between the housing 41 and the sun gear S1 and the sun gear S2.
And the brake B2 are provided in series. The one-way clutch F1 is configured to be engaged when the sun gear S1 and the sun gear S2 try to reversely rotate in the direction opposite to the input shaft 20.

A brake B3 is provided between the carrier K1 and the housing 41, and a brake B4 and a one-way clutch F2 are provided between the ring gear R3 and the housing 41 in parallel. This one-way clutch F
2 is configured to be engaged when the ring gear R3 attempts to rotate in the reverse direction.

In the automatic transmission 14 configured as described above, for example, according to the operation table shown in FIG. 2, one of the reverse gears and the forward gears of which the gear ratios are sequentially different are switched to one of the gear stages. In FIG. 2, a circle indicates an engaged state, a blank indicates a released state, and a ● indicates an engaged state during engine braking. As is clear from FIG. 2, the brake B3 is engaged at the time of shifting to switch from another gear to the second speed, and released at the time of shifting to shift from the second speed to another. It is something. The brake B2 is the third gear from the second gear.
It is engaged at the time of gear shifting to switch to the high gear stage. When shifting between the second gear and the third gear, there are a period in which the disengaging side of the brakes B2 and B3 has an engaging torque, and a period in which the engaging side has an engaging torque. The so-called clutch-to-clutch shift is performed in which the shift is advanced while the shifts overlap.

As shown in FIG. 3, a first throttle valve 52 operated by an accelerator pedal 50 is provided in an intake pipe of an engine 10 of a vehicle, and a throttle actuator is used for suppressing the engine output which is normally open. A second throttle valve 56 controlled by 54 is provided. Further, an engine rotation speed sensor 58 for detecting the rotation speed N _E of the engine 10, an intake air amount sensor 60 for detecting the intake air amount Q of the engine 10, an intake air temperature sensor 62 for detecting the intake air temperature T _A , A throttle sensor 64 for detecting the opening degree θ _TH of the first throttle valve 52, a vehicle speed sensor 66 for detecting a vehicle speed V from the rotation speed N _OUT of the output shaft 42, a cooling water temperature T _{W of the} engine 10.
A coolant temperature sensor 68 for detecting a brake switch 70 for detecting the operation of the brake, and an operation position sensor 74 for detecting an operation position P _SH of the shift lever 72 is provided, from the sensors, the engine rotational speed N _E , Intake air amount Q, intake air temperature T _A , first throttle valve opening θ _TH , vehicle speed V, engine cooling water temperature T _W , brake operating state BK, shift lever 72 operating position P _SH The electronic control unit 76 and the electronic control unit 78 for shifting are supplied. Further, from the input shaft rotation sensor 73 for detecting the input shaft rotation speed N _E of the automatic transmission 14, that is, the rotation speed N _C0 of the clutch C0, the input shaft rotation speed N _IN, that is, the rotation speed N of the clutch C0.
A signal representing _C0 is supplied to the electronic shifting control device 78.
Further, a signal representing the hydraulic oil temperature T _OIL is supplied from the oil temperature sensor 75 for detecting the hydraulic oil temperature T _OIL in the hydraulic control circuit 84 to the electronic shift control device 78.

Further, as shown in FIG. 4, the shift lever 72 is operated to the P range, the R range, the N range, the D range, the 4 range, the 3 range, the 2 range, and the L range located in the front-rear direction of the vehicle. At the same time, the support mechanism is configured such that the range between the D range and the 4 range and the range between the 2 range and the L range are operated in the left-right direction of the vehicle.

The engine electronic control unit 76 includes a CPU,
A so-called microcomputer having a RAM, a ROM, and an input / output interface, the CPU processes an input signal according to a program stored in the ROM in advance while utilizing a temporary storage function of the RAM, and executes various engine controls. For example, the fuel injection valve 80 is controlled to control the fuel injection amount, the igniter 82 is controlled to control the ignition timing, a bypass valve (not shown) is controlled to control the idle speed, and the throttle actuator is controlled to control the traction. The second throttle valve 56 is controlled by 54. The engine electronic control unit 76 is communicably connected to a shift electronic control unit 78, and a signal required for one is appropriately transmitted from the other.

The shift electronic control unit 78 is also a microcomputer similar to that described above, and the CPU processes input signals in accordance with a program stored in the ROM in advance while utilizing the temporary storage function of the RAM. Of each solenoid valve or linear solenoid valve. For example,
The electronic shift control device 78 controls the linear solenoid valve SLT in order to generate the throttle pressure P _TH having a magnitude corresponding to the opening degree θ _TH of the first throttle valve 52 or to control the accumulator back pressure. The linear solenoid valve SLU is driven to control the engagement, disengagement, slip amount, and hydraulic pressure in the brake B3 during gear shifting.
Further, the electronic shift control device 78 determines the gear position of the automatic transmission 14 and the engagement state of the lockup clutch 24 based on the actual throttle valve opening θ _TH and the vehicle speed V from the previously stored shift diagram. However, the solenoid valves S1, S2, S3 are driven so as to obtain the determined gear and engagement state, and the solenoid valve S4 is used when engine braking is generated.
Drive.

FIGS. 5 and 6 show the hydraulic control circuit 84.
Are shown. 1-2 shift valves 88 and 2 shown
The -3 shift valve 90 is based on the output pressures of the solenoid valves S1 and S2, when shifting from the first gear to the second gear and when shifting from the second gear to the third gear. In the above, the switching valves are switched respectively, and the numerical value indicating the switching position indicates the gear position. The forward range pressure P _D is a pressure output from a manual valve (not shown) when the shift lever 72 is operated to the forward range (D, 4, 3, 2, L), and is a throttle valve operated by a regulator valve (not shown). The line pressure P _L, which is adjusted to a high level according to the opening, is used as the source pressure.

When a shift output for switching from the first gear to the second gear is output, the forward range pressure P is set.
_D is supplied to the brake B3 and the damper 94 for absorbing pressure vibration through the 1-2 shift valve 88, the 2-3 shift valve 90, the oil passage L01, the B3 control valve 92, and the oil passage L02. When a shift output for switching from the second gear to the third gear is output, the forward range pressure P _D becomes
Through the 2-3 shift valve 90 and the oil passage L03, the brake B2
And at the same time as being supplied to the B2 accumulator 100, the hydraulic oil in the brake B3 is supplied to the oil passage L02, the B3 control valve 92, the oil passage L01, the 2-3 shift valve 90, the return oil passage L04, and the 2-3 timing valve 98. , And is rapidly drained through a branch oil passage L05 branching from a return oil passage L04 and a B2 orifice control valve 96.

Back pressure chamber 1 of B2 accumulator 100
The output pressure P _SLT of the linear solenoid valve SLT is supplied to 00 _B at each shift, and the hydraulic pressure in the brake B2 is controlled.

The B3 control valve 92 is an accumulator.
The engagement pressure of the brake B3 not provided with a
Functioning as a pressure regulating valve to regulate the pressure dynamically,
A spool valve 104 that opens and closes between the oil passage L02 and
Installed concentrically with the spool valve 104 with the pulling 106 interposed
A plan with a diameter larger than that of the spool valve 104
The housing 108 and the spring 106, and
Is it when the shift valve 90 is switched to the third speed side?
Forward range pressure P output from_DReceived via oil passage L07
Provided at the oil chamber 110 for charging and the shaft end of the plunger 108
Control pressure P from the linear solenoid valve SLU_SLUReceived
An oil chamber 112 is provided. Therefore, B3
The control valve 92 is a linear valve when shifting from 1 to 2
Control pressure P of renoid valve SLU_SLUAccording to spool valve 1
Position 04 in the open position shown to the left of the centerline
Tofil is performed at the initial stage, and then oil passage L0
1 to supply the hydraulic oil to the oil passage L02, or the oil passage L02.
02 by causing the hydraulic oil in 02 to flow out to the discharge oil passage L06.
Engagement pressure P in the brake B3_B3Rise speed is constant
The pressure is adjusted so that the engagement of the brake B3 is predicted.
Just before the time to launch quickly. Also, when shifting from 2 to 1
The solenoid valves S1 and S2 are maintained at the second speed shift output.
Therefore, the D range pressure is held in the oil passage L01, and
3 control valve 92 has control pressure P_SLUAccording to the prescribed
After the pressure is reduced at the speed, hydraulic oil is stored in the brake B3.
When it is assumed that the brake B3 is supplied,
A preset pressure value P that is set immediately before_SLUHTo
It is maintained until it is determined that the first gear is completed.
Keep it up. Further, the B3 control valve 92 is
Even in the case of 3 → 2 shift and 2 → 3 shift, the brake B3
The engagement pressure and the release pressure of the control pressure P_SLUDirectly according to
Control. In the formula 1, S₁ And S ₂ Is
The cross-sectional area of the runner 108 and the spool valve element 104.
You.

[0027]

[ _Equation 1] P _B3 = P _SLU · S ₁ / S ₂

The B2 orifice control valve 96 is connected to the brakes B2 and B2 accumulator 100 and the oil passage L0.
3, a spool valve 114 for opening and closing between the discharge oil passage L06 and the drain port 113 at the same time as opening and closing, a spring 116 for urging the spool valve 114 toward the first drain position, and a spool valve 114. and an oil chamber 120 for receiving through the output pressure P _S3 the 3-4 shift valve 118 of the third solenoid valve S3, provided on the shaft end. As a result, the third solenoid valve S3 can be used, for example, during a 3 → 2 shift.
Is turned on, and its output pressure P _S3 is no longer supplied to the oil chamber 120. Therefore, the spool valve 114 opens the brakes B2 and B2 between the accumulator 100 and the oil passage L03, and the brakes B2 and B2 accumulator are opened. A first drain operation for quickly discharging the hydraulic oil from the engine 100 is performed. In the 1 → 2 shift, the third solenoid valve S3 is turned off and the control pressure P _S3
Is supplied to the oil chamber 120, the space between the drain port 113 and the drain oil passage L06 through which the hydraulic oil discharged from the B3 control valve 92 is discharged and the drain port 113 is opened to open the B3 control valve 92. Although the pressure adjusting operation is allowed, when the 1 → 2 shift is completed, the third solenoid valve S3 is turned on, and the discharge oil passage L06 and the drain port 113 are turned on.
And the B3 control valve 92 is closed.
The pressure regulating operation of is stopped.

The 2-3 timing valve 98 is involved in the clutch-to-clutch shifting from the second gear to the third gear, and releases the release pressure from the brake B3 to the linear solenoid valve SL.
It functions as a drain pressure regulating valve that regulates pressure from U according to control pressure P _SLU . That is, the 2-3 timing valve 98 is
The relatively high forward range pressure P _D (the same value as the line pressure) output from the 2-3 shift valve 90 when the 2 → 3 shift is output is supplied through the 3-4 shift valve 118 and the solenoid relay valve 122. The high pressure port 124, the drain port 126, and the oil passage L04 that are connected to the high pressure port 12
4 or a spool valve 128 that adjusts the pressure P _B3 in the drain period of the brake B3 by communicating with the drain port 126, and is provided concentrically with the spool valve 128 via a spring 130 and is the same as the spool valve 128. A first plunger 132 having a diameter, and a second plunger 134 concentric with the spool valve 128 and capable of contacting one end thereof and having a diameter larger than the spool valve 128.
The oil chamber 1 which accommodates the spring 130 and receives the forward range pressure P _D output from the 2-3 shift valve 90 when the 2-3 shift valve 90 is switched to the second speed side via the oil passage L08.
36, an oil chamber 138 provided at the shaft end of the first plunger 132 for receiving the control pressure P _SLU from the linear solenoid valve SLU, and an oil chamber 138 provided at the shaft end of the second plunger 134.
An oil chamber 140 for receiving the hydraulic pressure P _B2 of the brake B2,
Feedback oil chamber 14 for receiving feedback pressure
2 is provided.

Therefore, the sectional area of the spool valve element 128 and the first plunger 132 is S ₃ , and the spool valve element 12 is
8, the land area on the second plunger 134 side is S ₄ ,
When the cross-sectional area of the second plunger 134 and S _5, 2 → 3
Brake B in the release process when the gearshift output is output
The pressure P _B3 of No. 3 decreases according to the increase of the engagement pressure P _B2 of the brake B2 from the mathematical expression 2 by the pressure adjusting operation by the 2-3 timing valve 98, and the control pressure P of the linear solenoid valve SLU is reduced.
_The pressure is adjusted to increase according to the _SLU .

[0031]

## EQU2 ## P _B3 = P _{SLU .S 3} / (S ₃ −S ₄ ) −P _{B2.
S 5 / (S 3 -S 4} )

Further, when the forward range pressure P _D output from the 2-3 shift valve 90 switched to the second speed side is supplied to the oil chamber 136, the 2-3 timing valve 98 outputs the spool valve. The child 128 is adapted to be locked. This is also the oil chamber 138 of the 2-3 timing valve 98 and B
Since the oil chamber 112 of the third control valve 92 is connected, the change in the volume of the oil chamber 138 of the 2-3 timing valve 98 is prevented in the first speed and the second speed, and the B3 control valve 92 is closed. This is so as not to affect the pressure regulation operation.

[0033] C0 exhaust valve 150, the output pressure P _S4 of the third but brought into the closed position in accordance with the hydraulic pressure in the output pressure P _S3 and the oil passage L01 of the solenoid valve S3, the fourth solenoid valve S4
Accordance with the spool 152 is caused to position to the open position, the line pressure P _L supplied via it when the 4-5 shift valve (not shown) is in switching state of the following fourth speed, the second speed And clutch C at times other than the fifth speed
0 and the C0 accumulator 154.

FIGS. 7 and 8 detail the brake B3 and the linear solenoid valve SLU, which are engaged to achieve the second gear, respectively.
In FIG. 7, the brake B3 is an annular piston 162 slidably fitted in an annular groove 160 of a piston housing 158 fixed to the housing 41, and is not rotatable about the axis with respect to the housing 41 and the carrier K1. An annular friction plate 16 movably engaged in the axial direction
4 and 166 and a stopper 168 fixed to the housing 41 and receiving a thrust force from the piston 162. When the working hydraulic pressure in the oil chamber 170 in the piston housing 158 is increased, one end of a return spring (not shown) The annular piston 162 is advanced against the return force from the annular spring receiver 172 that is received,
After packing the pack clearance 173, which is the space between the friction plates 164 and 166, the friction plates 1
64 and 166 are squeezed between the stopper 168 and an engaging torque. That is, in the brake B3,
When the hydraulic pressure in the oil chamber 170 is increased from zero, the rising response of the engagement torque is delayed by the time for closing the pack clearance 173.

The linear solenoid valve SLU has a modulator pressure P _M which is regulated at a constant pressure with the line pressure P _L as a source pressure.
Of the spool valve 17 for opening and closing between the input port 174 supplied with the pressure and the output port 176 outputting the control pressure P _SLU.
8, a spring 180 for urging the spool valve 178 in the valve closing direction, and a spring 180 for urging the spool valve 178 in the valve opening direction according to a command value (driving current or duty ratio) DSLU from the electronic shift control device 78. And a feedback chamber 186 that urges the spool valve 178 in the valve closing direction by introducing the control pressure P _SLU through the _fine hole 184. That is, the pressure-receiving area of the feedback chamber 186 in the valve closing direction is S
₆ , the thrust of the electromagnetic solenoid 182 is F, the spring 18
When the load of 0 is W, the control pressure P _SLU is output according to Equation 3. In the linear solenoid valve SLU configured as described above, when the command value DSLU becomes zero, the spool valve element 178 is positioned at its closed position, that is, the uppermost position in FIG. 8 according to the urging force of the spring 180. , When the command value DSLU is increased from zero,
For example, as shown by the broken line in FIG.
There is a time delay in the rising of the control pressure P _SLU , which corresponds to the time when reaches the operating position.

[0036]

[ _Equation 3] P _SLU = (FW) / S ₆

FIG. 10 is a functional block diagram for explaining the main part of the control function of the electronic shift control device 78. In the figure, the automatic shift determination means 188 indicates the automatic transmission 14
In order to automatically shift gears, the actual vehicle state such as the vehicle speed and the engine load (for example, the vehicle speed and the engine load (for example, the vehicle speed) and the engine load (for example, the vehicle speed and the engine load, for example, Shift determination is performed based on the throttle valve opening). For example, when the actual vehicle speed exceeds the shift point vehicle speed determined based on the actual engine load from the 1 → 2 shift up line, the upshift is determined, and the 2 → 1 shift down line is actually used. The downshift is determined when the actual vehicle speed is lower than the shift point vehicle speed determined based on the engine load.

When the automatic shift judging means 188 judges the shift for releasing the brake B3, the shift hydraulic pressure control means 190 supplies the B3 control valve 92 from the linear solenoid valve SLU during the shift period. The release pressure of the brake B3 is controlled by changing the control pressure P _SLU . The shift hydraulic control unit 190 rapidly reduces the control pressure P _SLU from its maximum value (100%) to the continuous reduction initial value P _{SLUI, and} then continuously changes the control pressure P _SLU at a predetermined reduction rate R. When the sweep control means 192 for decreasing and the control pressure P _SLU continuously decreased by the sweep control means 192 reach the set pressure value P _SLUH , the control pressure is maintained at the set pressure value P _{SL UH.} And holding means 194.

The set pressure value P _SLUH held by the control pressure holding means 194 changes its minimum value of the control pressure P _SLU supplied to the B3 control valve 92 during the shift period in which the brake B3 is released. It is a preset value that is larger than the lower limit value (zero) of the range by a predetermined value, and is preferably preset so that the operating hydraulic pressure in the brake B3 is at a level that is almost immediately before the engagement of the brake B3.
As a result, during the 2 → 1 shift period in which the brake B3 is released, the control pressure P _SLU supplied to the B3 control valve 92 by the control pressure holding means 194 is the operating hydraulic pressure in the brake B3. Set pressure value P that is set in advance so that
As a result of being held at _SLUH , the control pressure P _SLU is previously held at the set pressure value P _SLUH when another shift, for example, a multiple shift that performs 1 → 2 shift is executed in the shift period in which the brake B3 is released. Therefore, when the control pressure P _SLU is to be supplied again to the B3 control valve 92 to reengage the brake B3 during execution of the multiple shift, the flow rate change on the output side of the linear solenoid valve SLU is small and desired. The response delay of the linear solenoid valve SLU until the control pressure P _SLU is generated is significantly shortened.

The gear shift completion determining means 196 is provided for the brake B3.
Shifting achieved by releasing the gear, eg 2 → 1
It is determined whether the gear shift is completed. The control pressure holding unit 194 sets the control pressure P _SLU to the set pressure value P until the shift completion determination unit 196 determines that the shift has been completed.
_Hold in _SLUH .

Further, the sweep control means 192 detects the throttle valve opening θ _TH detected by the throttle sensor 64 corresponding to the engine load detection means, that is, the vehicle engine load and the hydraulic oil temperature detection from the relationship stored in advance. The continuous decrease initial value P _SLUI and the decrease rate R of the control pressure P _SLU are substantially determined based on the hydraulic oil temperature T _OIL detected by the oil temperature sensor 75 corresponding to the means.

FIG. 11 is a flow chart showing the main part of the control operation by the electronic shift control device 78, that is, the shift control for executing the 2 → 1 shift. The steps corresponding to the automatic shift judging means 188 are well known and therefore omitted.

In step S1 of FIG. 11 (hereinafter, steps will be omitted), the automatic shift determination means 188 determines 2
→ It is determined whether or not a 2 → 1 shift is in progress after the 1 → shift is determined. If the determination in S1 is denied,
This routine is repeated through another routine (not shown), but if the result is affirmative, the sweep control means 19 is used.
In S2 and S3 corresponding to 2, the control pressure P _SLU is continuously reduced.

That is, at S2, the actual throttle valve opening θ _TH is calculated from the relationship stored in advance as shown in FIG. 12, for example.
And the continuous decrease initial value DS based on the hydraulic oil temperature T _OIL
When the LUI is calculated, the command value is the maximum value (1
The control pressure P _SLU is rapidly decreased from the maximum value (100%) to the continuous decrease initial value P _SLUI by being rapidly decreased from 00%) to the continuous decrease initial value DSLUI. The time point t _{1 in} FIG. 14 indicates this point. Next, in S3, for example, from a prestored relationship shown in FIG. 13, a reduction amount DD21PU1 or a reduction ratio (DD21PU) per constant reduction period, for example, 16 ms, is determined based on the actual throttle valve opening θ _TH and the hydraulic oil temperature T _OIL.
1/16 ms) is calculated, and the command value D after the reduction amount DD21PU1 is subtracted from the previous command value DSLU _i-1
The output from SLU _i causes the control pressure P _SLU to start decreasing at the reduction rate R.

Next, in S4 corresponding to the shift completion determining means 196, it is determined whether or not the 2 → 1 shift is completed. In this S4, for example, the ratio N _IN / N of the input shaft rotation speed N _{IN of the} automatic transmission 14 to the output shaft rotation speed N _OUT
It is determined based on whether _OUT has reached the gear ratio i ₁ of the first gear. Since the determination in S4 is initially denied, it is determined in S5 whether or not the command value DSLU _{i of} this time is equal to or less than the preset set value KSLU. The set value KSLU is a value that has been experimentally obtained in advance in order to generate the control pressure with the brake B3 almost immediately before the engagement.

Initially, the determination at S5 is denied, so
The steps S3 and below are repeatedly executed, but when the control pressure P _SLU continuously decreases to the set value KSLU or below, the determination in S5 is affirmed, so the control pressure holding means 1
In S6 corresponding to 94, after the command value DSLU _i output in the current control cycle is replaced with the preset setting value KSLU, the above S3 and the following steps are repeatedly executed. As a result, the control pressure P _SLU becomes the set pressure value P _SLUH.
Is held. The time t _{2 in} FIG. 14 indicates this point.

While the above steps are repeatedly executed, if the determination at S4 is affirmative, the termination control at S7 is executed and the command value DSLU and the control pressure P _SLU are made zero. The time point t _{3 in} FIG. 14 indicates this point.

In the present embodiment, as described above, the brake B
During the 2 → 1 shift period executed by releasing 3, the control pressure holding means 194 corresponds to S6.
Since the minimum value of the control pressure P _SLU supplied to the B3 control valve 92 is maintained at a preset pressure value P _SLUH that is larger than the lower limit value (zero) of the change range by a predetermined value, When a multiple shift is performed in which the 1 → 2 shift is performed in the 2 → 1 shift period, the control pressure P _SLU is held at the set pressure value P _SLUH in advance, so that the brake B3 is re-engaged when the multiple shift is performed. In order to supply the control pressure P _SLU to the B3 control valve 92 again, the flow rate change on the output side of the linear solenoid valve SLU is small. For example, as shown by the solid line in FIG. As a result, the response delay of the linear solenoid valve SLU until the desired control pressure is generated is greatly reduced.
Therefore, the occurrence of the shift shock resulting from the responsiveness of the linear solenoid valve SLU is preferably eliminated.

FIG. 15 is a time chart showing the above effects. In the figure, 1 → 2 during 2 → 1 shift
When the gear shift is executed multiple times, the command value DSLU is held at the set value KSLU and the control pressure P _SLU is set at the set pressure value P.
_In this embodiment, which is held at _SLUH, when the command value DSLU is immediately increased in order to engage the brake B3, the control pressure P _SLU also immediately starts to increase as shown by the solid line. However, in the conventional example in which the command value DSLU is not held at the set value KSLU and the control pressure P _SLU is not held at the set pressure value P _SLUH , the responsiveness of the linear solenoid valve SLU is first indicated by the broken line. The command value DSLU is increased stepwise in order to increase the control value, and the command value DSLU is continuously increased after the control pressure P _SLU can be output. Therefore, a time delay A is formed in the command value DSLU. , A time delay B is formed in the control pressure P _SLU .

In the present embodiment, for example, FIG.
5, S6 corresponding to the control pressure holding means 194
As a result, the control pressure P _SLU supplied to the B3 control valve 92 is held at a set pressure value P _SLUH preset so that the control pressure P _SLU is approximately immediately before the _engagement of the brake B3. Since the piston 162 is advanced to the position where the pack clearance 173 is filled, the response delay of the rising of the operating hydraulic pressure in the brake B3 is significantly shortened. Therefore, the brake B3
The occurrence of the shift shock due to the responsiveness of is preferably eliminated.

Further, according to the present embodiment, in S2 and S3 corresponding to the sweep control means 192, the continuous decrease initial value P _SLUI or DSLUI and the decrease rate R of the control pressure P _SLU , that is, the decrease amount DD21PU1 of the command value DSLU are set. Is calculated based on the actual throttle valve opening θ _TH and the hydraulic oil temperature T _OIL from the pre-stored relationships shown in FIGS. 12 and 13, so that the hydraulic pressure in the brake B3 in the 2 → 1 shift period is Also, there is an advantage that the transmission torque of the automatic transmission 14 or the viscosity of the hydraulic oil is taken into consideration to control to an optimum value.

While the embodiment of the present invention has been described with reference to the drawings, the present invention can be applied to other embodiments.

For example, in the above embodiment, 2 → 1
The multiple shift in which the 1 → 2 shift is determined within the shift period has been described.
→ It may be the case where the second gear is determined. In this case, since the hydraulic pressure in the brake B3 is drained by the increase in the hydraulic pressure in the brake B2, the brake B3 is maintained even if the control pressure P _SLU is held at the set pressure value P _SLUH. Since the pressure does not remain inside, the responsiveness of the rising of the brake B3 is not improved, but the responsiveness of the linear solenoid valve SLU is improved, and accordingly, the shift shock is prevented.

Further, in the automatic transmission 14 of the above-described embodiment, the operating oil pressure in the brake B3 is the B3 control valve 9
Although the hydraulic pressure in the other hydraulic friction engagement device may be directly controlled by the control unit 2, the hydraulic pressure in another hydraulic friction engagement device may be directly controlled.

Further, in the above-described embodiment, the control pressure P _SLU supplied to the B3 control valve 92 during the shift period for releasing the brake B3 is set in advance so that the control pressure P _SLU is substantially immediately before the engagement of the brake B3. The set pressure value P _SLUH was held, but the set pressure value P _{SLUH
If SLUH} is a value larger than the lower limit value zero of the change range, a certain improvement effect can be obtained in the response of the linear solenoid valve SLU.

Although not illustrated one by one, the present invention can be implemented in various modified and improved modes based on the knowledge of those skilled in the art.

[Brief description of drawings]

FIG. 1 is a diagram illustrating a configuration of an automatic transmission for a vehicle in which a gear stage is controlled by a shift control device according to an embodiment of the present invention.

FIG. 2 is a chart showing a relationship between a combination of operations of a plurality of hydraulic friction engagement devices and gear stages established by the combination in the automatic transmission of FIG.

FIG. 3 is a block diagram including a hydraulic control circuit and an electronic control circuit for controlling the automatic transmission of FIG. 1;

FIG. 4 is a diagram illustrating an operation position of a shift lever of FIG. 3;

FIG. 5 is a diagram illustrating a main part of the hydraulic control circuit in FIG. 3 together with FIG. 6;

6 is a diagram illustrating a main part of the hydraulic control circuit in FIG. 3 together with FIG. 5;

7 is a diagram illustrating in detail the configuration of a brake B3 used in the automatic transmission of FIG.

FIG. 8 is a diagram illustrating in detail the configuration of the linear solenoid valve of FIGS. 3 and 6;

FIG. 9 is a diagram for explaining response characteristics of the linear solenoid valve of FIGS. 3 and 6 in comparison with the conventional one shown by a broken line.

10 is a functional block diagram illustrating a main part of a control function of the electronic shift control device of FIG.

11 is a flowchart illustrating a main part of a control operation of the electronic shift control device of FIG. 3, showing a 2 → 1 shift control routine.

12 is a diagram showing a relationship used for obtaining a continuous lowering initial value DSLUI in the flowchart of FIG.

13 is a command value DS in the flowchart of FIG.
It is a figure which shows the relationship used in order to calculate | require the reduction amount DD21PU1 of LU.

FIG. 14 is a flow chart of 2 controlled by the flowchart of FIG.
→ It is a time chart explaining the change of the command value of 1 shift.

FIG. 15 is a flow chart of 2 controlled by the flowchart of FIG.
9 is a time chart showing changes in the command value DSLU and the control pressure P _SLU at the time of multiple shift in which the determination of 1 → 2 shift is made during the → 1 shift, in comparison with the conventional example shown by the broken line.

[Explanation of symbols]

 14: Automatic transmission 92: B3 control valve 92 (pressure regulating valve) SLU: Linear solenoid valve (solenoid valve) Brake B3: Hydraulic friction engagement device

Claims (1)

[Claims] 1. A pressure regulating valve for regulating an operating hydraulic pressure in a hydraulic friction engagement device which is engaged to achieve a predetermined gear stage but released to achieve another gear stage, A vehicle having a solenoid valve that outputs a control pressure for controlling the pressure regulating valve, and directly controlling the operating hydraulic pressure in the hydraulic friction engagement device to a value according to the control pressure during a shift period. A shift control device for an automatic transmission for a vehicle, wherein the minimum value of the control pressure supplied to the pressure regulating valve during a shift period in which the hydraulic friction engagement device is released is:
A shift control device for an automatic transmission for a vehicle, comprising control pressure holding means for holding a preset pressure value which is larger than a lower limit value of the change range by a predetermined value.