JPH04131563A - Hydraulic control device for vehicular automatic transmission - Google Patents

Abstract

PURPOSE:To prevent the lowering of control oil pressure regulating accuracy by correcting the control signal value of a linear valve in such a way that a pressure switch is operated at the time of the output signal pressure of the linear valve reaching the set pressure value of the pressure switch to generate an electric signal. CONSTITUTION:On the basis of an 'on' or 'off' signal from a pressure switch 476 operated on the basis of the change of the output signal pressure of a linear valve 390 and the driving current value (control signal value) supplied to the linear valve 390, the driving current value is corrected in such a way that the pressure switch 476 is operated at the time of the actual output signal pressure of the linear valve 390 reaching the value corresponding to the set pressure value of the pressure switch 476 so as to generate an 'on' or 'off' signal. Accordingly, even if the output characteristic of the linear valve 390 is changed by the solid difference of the linear valve 390 and the elapsed change, the driving current value is corrected in such a way that the relation between the driving current value supplied to the linear valve 390 and the output signal pressure is placed into the previously memorized state, so that the pressure regulating accuracy of the second line oil pressure Pl2 is prevented from being lowered.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a hydraulic control device for an automatic transmission for a vehicle.

BACKGROUND OF THE INVENTION Automatic transmissions for vehicles in which the gear ratio is automatically changed are known. Examples include a belt-type continuously variable transmission in which the gear ratio can be changed steplessly, and an automatic transmission (so-called A/T) in which multiple sets of planetary gears are combined. The above-mentioned belt type continuously variable transmission is equipped with a transmission belt that transmits power by being wrapped around a pair of variable booleans with variable effective diameters, and is based on control oil pressure that is changed in relation to input torque. The clamping force of the transmission belt is generated. In addition, the automatic transmission is equipped with a plurality of brakes and clutches for connecting the components of the planetary gear or receiving reaction forces, and is equipped with a plurality of brakes and clutches for connecting the components of the planetary gear or for receiving reaction forces, based on the control oil pressure that is changed in relation to the input torque. The brakes and clutches are then activated.

In other words, in the belt-type continuously variable transmission and automatic transmission, friction members such as the transmission heald, clutch, and brake are pressed by control hydraulic pressure (line pressure), and the torque transmission capacity is determined according to the pressing force. ing.

For example, patent application No. 2-13448 filed earlier by Junto Honde.
As described in No. 9, the automatic transmission has a pressure regulating valve that regulates the basic oil pressure in order to apply pressing force to the friction member, and an output signal that continuously changes according to the control signal value. A hydraulic control device may be provided that includes a linear valve that supplies pressure to the pressure regulating valve and shifts the basic hydraulic pressure regulated by the pressure regulating valve to bring the basic hydraulic pressure closer to the optimum hydraulic pressure. . In this type of hydraulic control device, the basic oil pressure regulated by the pressure regulating valve based on the throttle opening and gear ratio is shifted by the output signal pressure of the linear valve to match the optimum oil pressure.
Since the control oil pressure that is accurately set to the optimum oil pressure can be obtained, power loss is suitably improved and the durability of the transmission belt is improved.

Problems to be Solved by the Invention By the way, the linear valve used in the above hydraulic control device has the following problems:
The valve element, which is driven by the electromagnetic force generated by the linear solenoid, is moved and positioned to a position where it balances with the biasing force of the spring, thereby generating an output signal pressure according to the control signal value. Due to individual differences in the linear valve or changes over time, the output signal pressure corresponding to the control signal value may vary, making it impossible to obtain the accuracy of the control oil pressure value.

The present invention has been made against the background of the above circumstances,
The purpose of this is to correct the output signal pressure from the linear valve according to changes in its characteristics, thereby preventing a decline in control hydraulic pressure regulation accuracy due to differences in linear valve facepieces or changes over time. An object of the present invention is to provide a hydraulic control device for an automatic transmission.

Means for Solving the Problems The gist of the present invention for achieving the above object is to apply a pressing force to the friction members in the automatic transmission in which power is transmitted through the friction members. A pressure regulating valve regulates the basic oil pressure in order to apply the pressure, and an output signal pressure that continuously changes according to the control signal value is supplied to the pressure regulating valve, and the basic oil pressure regulated by the pressure regulating valve is shifted. A hydraulic control device comprising: a linear valve that approximates a basic hydraulic pressure to an optimum hydraulic pressure; (a) a pressure switch that generates an activation signal when the output signal pressure of the linear valve reaches a predetermined set pressure value; and β) generated from the control signal value supplied to the linear valve and the pressure switch such that the actuation signal is generated when the output signal pressure of the linear valve reaches a value corresponding to the set pressure value. and control signal correction means for correcting the control signal value based on the actuation signal.

Operation and Effect of the Invention With this structure, the control signal correction means can adjust the output signal based on the operating signal from the pressure switch that operates based on the change in the output signal pressure of the linear valve and the control signal value supplied to the linear valve. Then, the control signal value is corrected so that when the output signal pressure of the linear valve reaches a value corresponding to the set pressure value of the pressure switch, the pressure switch is activated and an electric signal is generated. Therefore, even if the characteristics of the linear valve's output signal pressure change due to individual differences in the linear valve or changes over time, the relationship between the control signal value supplied to the linear valve and the linear valve's output signal pressure will remain in its original state. Since the control signal value is corrected in this way, a decrease in control oil pressure regulation accuracy due to individual differences in linear valves, changes over time, etc. is prevented.

EXAMPLE Hereinafter, an example of the present invention will be described in detail based on the drawings.

In FIG. 2, the power of the engine 10 is transmitted through a fluid coupling 12 with a lock-up clutch and a belt-type continuously variable transmission (hereinafter referred to as
The power is transmitted to drive wheels 24 connected to a drive shaft 22 via a CVT (CVT) 14, a forward/reverse switching device 16, an intermediate gear device 18, and a differential gear device 20.

The fluid coupling 12 connects a pump impeller 28 connected to the crankshaft 26 of the engine 10 and an input shaft 3 of the CVT 14.
a turbine impeller 32 fixed at zero and rotated by oil from the pump impeller 28; a lock-up clutch 36 fixed to the input shaft 30 via a damper 34;
An engagement side oil chamber 33 connected to an engagement side oil passage 322 described below and a release side oil chamber 3 connected to a release side oil passage 324 described below.
5. The inside of the fluid coupling 12 is always filled with hydraulic oil, and for example, when the vehicle speed exceeds a predetermined value,
Alternatively, when the rotational speed difference between the pump impeller 28 and the turbine impeller 32 becomes less than a predetermined value, hydraulic oil is supplied to the retaining side oil chamber 33 and hydraulic oil is flowed out from the releasing side oil chamber 35. The lock-up clutch 36 is engaged, and the crankshaft 26 and the input shaft 30 are directly connected.

On the other hand, when the vehicle speed falls below a predetermined value or when the rotational speed difference exceeds a predetermined value, hydraulic oil is supplied to the release side oil chamber 35 and hydraulic oil flows out from the maintenance side oil chamber 33. As a result, the lock-up clutch 36 is released.

The CVT 14 includes variable pulleys 40 and 42 of the same diameter provided on the input shaft 30 and output shaft 38, respectively, and a transmission belt 44 wound around the variable pulleys 40 and 42.

The variable pulleys 40 and 42 are fixed rotating bodies 46 and 48 fixed to the input shaft 30 and the output shaft 38, respectively, and are provided on the input shaft 30 and the output shaft 38 so as to be movable in the axial direction but not relatively rotatable around the axes. The movable rotating bodies 50 and 52 are
is moved by the primary side hydraulic cylinder 54 and the secondary side hydraulic cylinder 56 that function as hydraulic actuators, ■ the groove width, that is, the hanging diameter (effective diameter) of the transmission belt 44 is changed, and the gear ratio T(-) of the CVT 14 is changed.
Rotational speed N of the human power shaft 30, /rotational speed N of the output shaft 38
. ut) is now being changed. Since the variable pulleys 40 and 42 have the same diameter, the hydraulic cylinder 5
4 and 56 have similar pressure receiving areas. Typically, the pressure in the driven side of hydraulic cylinders 54 and 56 is related to the tension in transmission belt 44.

The forward/reverse switching device 16 is a well-known double-binion type planetary gear mechanism, and includes a pair of planetary gears 62 and 64 that are rotatably supported by a carrier 60 fixed to an output shaft 58 and mesh with each other. Switching device 1
A sun gear 66 that is fixed to the input shaft (output shaft of the CVT 14) 38 of No. 6 and meshes with the planetary gear 62 on the inner peripheral side, a ring gear 68 that meshes with the planetary gear 64 on the outer peripheral side, and a reverse drive for stopping the rotation of the ring gear 68. brake 70, the carrier 60, and the input shaft 38 of the forward/reverse switching device 16.
and a forward cranchier 2 that connects. The reverse brake 70 and the forward clutch 72 are hydraulically operated friction engagement devices, and when they are not engaged, the forward/reverse switching device 16 is in a neutral state and power transmission is cut off. . However, when the forward clutch 72 is engaged, the output shaft of the CVT 14 and the output shaft 58 of the forward/reverse switching device 16 are directly connected to transmit power in the forward direction of the vehicle. In addition, the reverse brake 70
When engaged, the rotation direction is reversed between the output shaft 38 of the CVT 14 and the output shaft 58 of the forward/reverse switching device 16, so that power in the backward direction of the vehicle is transmitted.

FIG. 3 shows in detail the hydraulic control circuit of FIG. 2 for controlling the vehicle power transmission system. oil pump 74
constitutes the hydraulic power source of this hydraulic control circuit, and is integrally connected with the pump impeller 28 of the fluid coupling 12 so that it is constantly rotationally driven by the crankshaft 26. The oil pump 74 sucks the hydraulic oil that has returned to an oil tank (not shown) through the strainer 76, and also sucks the hydraulic oil that has been returned through the return oil passage 78 and pumps it to the first line oil passage 80. . In this embodiment, the hydraulic oil in the first line oil passage 80 is leaked to the return oil passage 78 and the lock-up clutch pressure oil passage 92 by the overflow (relief) type first pressure regulating valve 100, so that the hydraulic oil in the first line oil passage 80 is leaked to the return oil passage 78 and the lockup clutch pressure oil passage 92. The first line oil pressure P in the oil passage 80 is regulated. In addition, the first line oil pressure Pf is controlled by the second pressure regulating valve 102 of the pressure reducing valve type.
, in the second line oil passage 82 due to the reduced pressure.
The line oil pressure Plz is regulated. This second line oil pressure Pl□ is regulated to control the tension of the transmission belt 44, so it corresponds to the tension control pressure of this embodiment.

First, the configuration of the second pressure regulating valve 102 will be explained. As shown in FIG. 4, the second pressure regulating valve 102 includes a spool valve 11 that opens and closes between the first line oil passage 80 and the second line oil passage 82.
0, spring seat 112, return spring 11
4. It is equipped with a plunger 116. Spool bento 11
0, a first land 118 and a second land 118 having larger diameters in order of diameter.
A land 120 and a third land 122 are formed sequentially.

A chamber 126 is provided between the second land 120 and the third land 122, into which the second line hydraulic pressure PA is introduced through the throttle 124 as feedback pressure, and the spool valve 110 is connected to the second line hydraulic pressure P! 2, the valve is biased toward the valve closing direction. In addition, spool valve 110
A chamber 130 is provided on the end surface side of the first land 11B, through which a gear ratio pressure Pr (described later) is guided through a throttle 128, and the spool valve element 110 is biased in the valve closing direction by the gear ratio pressure Pr. It has become so. Inside the second pressure regulating valve 102, the biasing force of the return spring 114 in the valve opening direction is applied to the spool valve element 110 through the spring seat 112.
has been granted. Further, the plunger 116 is formed with a land 117 and a land 119 having a slightly larger diameter than the land 117, and a chamber 132 is provided on the end surface side of the land 117 for applying a throttle pressure P (described later). The spool valve element 110 is biased in the valve opening direction by this throttle pressure F'th.

Therefore, the pressure receiving area of the first land 118 is A! The area of the cross section of the second land 120 is A! , the cross-sectional area of the third land 122 is A3, the pressure-receiving area of the land 117 of the plunger 116 is Aa, and the biasing force of the return spring 114 is W. balanced. That is, by moving the spool valve 110 according to formula (1), the hydraulic oil in the first line oil passage 80 guided to the boat 134a flows into the second line oil passage 82 via the boat 134b. The state in which the hydraulic oil in the second line oil passage 82 led to the boat 134b is communicated with the drain (Drainbow) 134C is repeated, and the second line oil pressure P12 is generated. be. Since the second line oil passage 82 is a relatively closed system, the second pressure regulating valve 102 reduces the second line oil pressure by reducing the first line oil pressure Pl, which is a relatively high oil pressure as described above. P12 is generated as shown in FIG.

Pfz=(An・Pth+W−AI・p,) / (A
3-A2) (1) Note that between the first land 118 and the second land 120 of the spool valve 110, there is a first relay valve 380, which will be described later.
A chamber 136 is provided through which a signal pressure P5oLL is introduced, through which the spool valve 110 receives the signal pressure P,.

When biased in the valve closing direction by 1L, the second line oil pressure P12 is reduced depending on the magnitude of the bias. Further, a control pressure P is provided between the land 117 and the land 119 of the plunger 116 via the first relay valve 380, a second relay valve 440 (described later), and a throttle 135.
. , l is provided to increase the pressure of the second line oil pressure P12, and the second line oil pressure Plz is increased in accordance with the signal pressure P5oLL. . The characteristics of the second line pressure Pf in the above case will be described in detail later.

As shown in FIG. 5, the first pressure training valve 100 includes a spool valve 140, a spring seat 142, a turn spring 144, a first plunger 146, and a second land 155 having the same diameter as the second land 155 of the first plunger 146. Two plungers 148 are provided. The spool valve 140 opens and closes between the drain boat 150a and the drain boat 150b or 150C, which communicate with the first line oil passage 80, and applies the first line oil pressure as feedback pressure to the end surface of the first land 152. A chamber 153 is provided for applying PR+ through a throttle 151, and this first line oil pressure P1. The spool valve element 140 is biased in the valve opening direction. Spool valve 140
Throttle pressure Pu
A chamber 156 is provided for guiding the
A chamber 157 is provided between the land 155 and the second plunger 148 for guiding the hydraulic pressure pin in the primary side hydraulic cylinder 54 via the branch oil passage 305. A chamber 158 is provided for guiding the second line oil pressure P12. The biasing force of the return spring 144 is applied to the spool valve element 140 in the valve closing direction via the spring seat 142, so that the pressure receiving area of the first land 152 of the spool valve element 140 is A5, and the first plunger 146 is When the cross-sectional area of the first runt 154 is A6, the cross-sectional area of the second land 155 and the second plunger 148 is A7, and the urging force of the return spring 144 is W, the following formula (2) holds true for the spool valve 140. balanced in position, the first line oil pressure P
! , is pressure regulated.

PR5= [(Pi, or Pf z) ' At+P
tb(A6-8t)+h)/8.

-(2) In the first pressure regulating valve 100, the negative side hydraulic cylinder 5
4 internal hydraulic pressure p in is the second line hydraulic pressure Pj22 (in steady state, Pβ2 = secondary side hydraulic cylinder 56 internal hydraulic pressure P.ut
), the first plunger 146 and the second plunger 148 are spaced apart, and the thrust due to the hydraulic pressure P, 7 in the next-side hydraulic cylinder 54 acts on the spool valve element 140 in the valve closing direction. However, when the hydraulic pressure P, o in the next-side hydraulic cylinder 54 is lower than the second line hydraulic pressure P12, the first plunger 146 and the second plunger 148 come into contact with each other, so that the end face of the second plunger 148 is The thrust due to the second line oil pressure Pit acting on the spool valve element 140 acts in the valve closing direction. That is, the second plunger 148, which receives the hydraulic pressure pin in the next-side hydraulic cylinder 54 and the second line hydraulic pressure P2□, applies an acting force based on the higher of these hydraulic pressures in the valve closing direction of the spool valve element 140. It is made to act on In addition, spool valve 140
A chamber 160 provided between the first land 152 and the second land 159 is open to a drain.

Returning to FIG. 3, the throttle pressure P represents the actual throttle valve opening θ in the engine 10, and is generated by the throttle valve opening detection valve 180.

Further, the gear ratio pressure Pr represents the actual gear ratio of the CVT 14 and is generated by the gear ratio detection valve 182. The throttle valve opening detection valve 180 includes a cam 184 that is rotated together with the throttle valve (not shown), and a plunger that engages with the cam surface of the cam 184 and is driven in the axial direction in relation to the rotation angle of the cam 184. 186, the thrust force from the plunger 186 applied via the spring 188, and the thrust force due to the first line hydraulic pressure P2 are positioned at a balanced position, thereby increasing the first line hydraulic pressure Pf.
The throttle valve 190 is provided with a spool valve element 190 that reduces the pressure of the throttle valve f and generates a throttle pressure P that corresponds to the actual throttle valve opening θ. FIG. 6 shows the relationship between the throttle pressure P and the actual throttle valve opening θ. , and the lock-up clutch pressure regulating valve 310, respectively.

The gear ratio detection valve 182 also includes a detection rod 192 that is in sliding contact with the input side movable rotating body 50 of the CVT 14 and is moved in the axial direction by an amount of displacement equal to the amount of displacement in the axial direction. By receiving the urging force from the spring 194 and the spring 194 correspondingly transmitting the urging force, and by being positioned at a position where the thrusts of both are balanced by receiving the second line oil pressure PE2, the discharge flow rate to the drain is reduced. It is equipped with a spool valve 19B that changes the spool valve. Therefore, for example, the gear ratio T becomes smaller and C
When the movable rotary body 50 approaches the fixed rotary body 46 on the input side of the VT 14 (■ groove width is reduced), the detection rod 192 is pushed in. Therefore, the oil is supplied from the second line oil passage 82 through the orifice 196 and the spool valve 198
As a result, the flow rate of the hydraulic oil discharged to the drain is reduced, so that the hydraulic pressure downstream of the orifice 196 is increased. This working oil pressure is the gear ratio pressure Pr, and as shown in FIG. 7, it is increased as the gear ratio γ decreases (changes to the speed increasing side). Then, the gear ratio pressure Pr generated in this way is passed through the oil passage 86 to the second pressure regulating valve 1.
02 and the third pressure regulating valve 220, respectively.

Here, the gear ratio detection valve 182 has an orifice 196
Since the gear ratio pressure Pr is generated by changing the release amount of the hydraulic oil of the second line hydraulic pressure PNz supplied from the second line oil passage 82 through the
While r is limited to a value equal to or higher than the second line oil pressure P12, the second pressure regulating valve 102, which operates according to equation (1) above, increases the second line oil pressure P! as the gear ratio pressure Pr increases. Decrease 2. Therefore, when the gear ratio pressure Pr increases to a predetermined value and becomes equal to the second line oil pressure PR2,
After that, both groups become saturated and become constant.

FIG. 8 shows the output characteristics of the basic output pressure (maximum value of the second line oil pressure Pβ2) Pmec, which is regulated in the second pressure regulating valve 102 according to the equation (1) in relation to the above-mentioned gear ratio pressure Pr. It shows. That is, the transmission belt 4 shown in FIG. 9 required for the low-pressure side line oil pressure in relation to the gear ratio γ.
The optimum control pressure for setting the tension of No. 4 to the optimum value, that is, the ideal pressure P. A characteristic that is relatively similar to the curve representing pt can be obtained only by the valve mechanism, and compared to the case where the second line hydraulic pressure P12 is generated using a continuously controlled electromagnetic pressure control servo valve, the hydraulic circuit has the advantage of being significantly cheaper. Basic output pressure P1 in FIG. 8 obtained by the valve mechanism of the second pressure regulating valve 102. ．． is the second pressure regulating valve 102
This value is mechanically determined in relation to the pressure receiving area of the spool valve 110 and plunger 116, etc., and is the ideal pressure P so that sufficient clamping force can be obtained even during sudden speed changes. It is set higher than 2t.

The third pressure regulating valve 220 generates an optimum third line oil pressure P13 for operating the reverse brake 70 and the forward clutch 72 of the forward/reverse switching device 16. This third pressure regulating valve 220 includes a spool valve 222 that opens and closes between the first line oil passage 80 and the third line oil passage 88.
, spring seat 224, return spring 226
, and a hyfranger 228. A chamber 236 is provided between the first land 230 and the second land 232 of the spool valve element 222, into which the third line oil pressure PR3 is introduced as feedback pressure through the throttle 234.
The spool valve element 222 is biased in the valve closing direction by the third line hydraulic pressure P13. Further, a chamber 240 to which the gear ratio pressure Pr is introduced is provided on the first land 230 side of the spool valve element 222, so that the spool valve element 222 is biased in the valve closing direction by the gear ratio pressure Pr. ing. Inside the third pressure regulating valve 220, a return spring 2260 applies a biasing force in the valve opening direction to the spool valve element 222 via the spring seat 224. Further, a chamber 242 for applying throttle pressure P is provided on the end face of the plunger 228.
is biased in the valve opening direction by this throttle pressure P. Moreover, between the first land 244 of the plunger 228 and the second land 246 having a smaller diameter,
3rd line oil pressure P only when going backwards! Chamber 24 for guiding 3
8 is provided. For this reason, the third line oil pressure P7!
3 is regulated to an optimum value based on the gear ratio pressure Pr and the throttle pressure P from the same equation (1) as above. This optimum value is a value necessary and sufficient to ensure that torque can be transmitted without slipping in the forward clutch 72 or the reverse brake 70. Furthermore, when traveling in reverse, the third line oil pressure P13 is guided into the chamber 248, so the force that urges the spool valve element 222 in the valve opening direction is increased and the third line oil pressure Pf3 is increased.

Thereby, in the forward clutch 72 and the reverse brake 70, suitable torque capacities can be obtained respectively during forward movement and reverse movement.

The third line hydraulic pressure Pis regulated as described above is selectively supplied to the forward clutch 72 or the reverse brake 70 by the manual valve 250. That is, the manual valve 250 includes a spool valve 254 that is moved in conjunction with the operation of the vehicle's shift lever 252, and is configured to move forward ranges such as L (low), S (second), and D (drive) ranges. 3rd line oil pressure PI! . On the other hand, when the R (reverse) range is being operated, the third line oil pressure Pβ3 is output from the boat 25.
6 to port 422a of reverse inhibit valve 420
and 422b, and further supplies the oil to the reverse brake 70 through the reverse inhibit valve 420, and at the same time allows oil to drain from the forward clutch 72, and is operated to N (neutral) and P (parking) ranges. In this case, drainage of oil from both the forward clutch 72 and the reverse brake 70 is allowed. Incidentally, the accumulators 342 and 340 are for gradually increasing the hydraulic pressure to smoothly advance frictional engagement, and are connected to the forward clutch 72 and the reverse brake 70, respectively. Furthermore, the shift timing valve 210 adjusts the transient inflow flow rate by closing the throttle 212 in response to an increase in the hydraulic pressure in the hydraulic cylinder of the forward clutch 72.

The first line oil pressure Pf regulated by the first pressure regulating valve 100 and the second line oil pressure P12 regulated by the second pressure regulating valve 102 are used in the transmission control valve device to adjust the gear ratio γ of the CVT 14. 260 to one and the other of the primary hydraulic cylinder 54 and the secondary hydraulic cylinder 56. The speed change control valve device 260 is composed of a speed change direction switching valve 262 and a flow rate control valve 264. Note that the fourth line oil pressure Pj2. is generated by the fourth pressure regulating valve 170 based on the first line oil pressure Pffi, and guided through the fourth line oil passage 370.

The fourth pressure regulating valve 170 includes a spool valve element 171 that opens and closes between the first line oil passage 80 and the fourth line oil passage 370, and a spring 172 that biases the spool valve element 171 in the valve opening direction. We are prepared.

A chamber 176 is provided between the first land 173 and the second land 174 of the spool valve element 171 to introduce the fourth line hydraulic pressure P14 to act as feedback pressure, while the spring 172 of the spool valve element 171
A signal pressure P, which will be described later, is applied to the end surface side of the plunger 175 that contacts the side end portion in the valve opening direction. Room 1 to introduce ,
77 is provided, the non-spring 1 of the spool valve 171
The end faces of 72 cases were open to the atmosphere. In the fourth pressure regulating valve 170 configured in this way, the spool valve element 171 is
It operates so that the biasing force in the valve-closing direction based on the feedback pressure corresponding to the fourth line oil pressure Pff4 is balanced with the biasing force in the valve-opening direction due to the spring 172 and the biasing force in the valve-opening direction based on the signal pressure P5oLL. As a result,
4th line oil pressure P! 4 is the signal pressure P5°1, which will be described later. The pressure is regulated to a value corresponding to the size of the

As shown in detail in FIG. 10, the speed change direction switching valve 262 is a spool valve controlled by the first electromagnetic valve 266, and is connected to a drain boat 278a communicating with the drain, the first connecting oil passage 270, Ports 278b, 278d, and 278f that communicate with a second connecting oil passage 272 and a third connecting oil passage 274 each having a first throttle 271, and a boat 278c to which the first line hydraulic pressure Pll is supplied through the throttle 276; A boat 278e to which the first line hydraulic pressure pH is supplied, a boat 278g to which the second line hydraulic pressure Pj22 is supplied, the deceleration side position (on side position) which is one end of the moving stroke (the upper end of the figure), and the other side of the moving stroke. A spool valve element 280 is slidably disposed between an end (lower end in the drawing) of a speed increasing side position (off side position), and this spool valve element 280 is biased toward the speed increasing side position. A spring 282 is provided. The spool valve element 280, which functions as a shift direction switching valve element, is provided with four lands 279a, 279b, 279c, and 279d. The end face of the spring 282 of the spool valve 280 is open to the atmosphere.

However, the lower end surface of the spool valve 280 has a first
When the solenoid valve 266 is in the ON state, that is, in the closed state, the fourth line oil pressure Pi! is regulated by the fourth pressure regulating valve 170. , , are applied, but when the first electromagnetic valve 266 is in the OFF state, that is, in the open state, the downstream side of the throttle 284 is exhausted and the fourth line oil pressure Pffi is not applied. When the first solenoid valve 266 is in the state shown on the ON side in the figure,
The speed change direction switching valve 262 is also in the position shown on the ON side in the figure,
When the first solenoid valve 266 is in the state shown on the OFF side in the figure,
The speed change direction switching valve 262 is also in the position shown on the OFF side in the figure. Therefore, during the period when the first electromagnetic valve 266 is in the on state, the spool valve element 280 is positioned at the deceleration side position and between the drain boat 278a and the boat 278b.
The spaces between boat 278e and boats 1-278f are opened, and the spaces between boats 278b and 2780, between boats 278d and 278e, and between boat 278' are opened.
and 278g are closed, but during the period when the first electromagnetic valve 266 is in the OFF state, the spool valve element 280 is positioned at the speed increasing side position, resulting in a switching state opposite to the above.

Note that the speed change direction switching valve 262 includes a spool valve 2
plunger 2 disposed coaxially with 80 and capable of abutting thereon;
81 and the signal pressure P generated by the linear valve 390
,. A deceleration oil chamber 283 is provided which receives Ll through an oil passage 285 and generates a thrust in a direction in which the spool valve element 280 moves toward the deceleration side position. This signal pressure P
sol, L are the first solenoid valve 266 and the second solenoid valve 26
It is also used to switch the speed change direction switching valve 262 to the deceleration side when the solenoids S1 and S2 of B are out of order.

The flow rate control valve 264 is a spool valve controlled by a second electromagnetic valve 268, and in this embodiment functions as a variable speed control valve. The flow rate control valve 264 communicates with the downstream side hydraulic cylinder 54 via the primary side oil passage 300 and is connected to the second side hydraulic cylinder 54 via the primary side oil passage 300.
A boat 286a that communicates with the connection oil passage 272, boats 286b and 286d that communicate with the first connection oil passage 270 and the third connection oil passage 274, respectively, and the secondary oil passage 302.
The boat 28 communicates with the secondary hydraulic cylinder 56 via the
6c and the flow rate non-suppressing side position in the increasing speed change mode, which is -4 of the moving stroke (the upper end of the figure), and the flow rate suppressing side position in the increasing speed changing mode, which is the other end of the moving stroke (the lower end of the figure). A spool valve element 288 is slidably disposed at the spool valve element 288, and a spring 290 biases the spool valve element 288 toward the flow rate suppression side position. The spool valve 288, which functions as a flow rate control valve, is provided with three lands 287a, 287b, and 287c for opening and closing between the boats. Similar to the speed change direction switching valve 262, the end face of the spring 290 of the spool valve element 288 is open to the atmosphere, so no hydraulic pressure is applied thereto. However, when the second electromagnetic valve 268 is in the ON state, that is, in the closed state, a fourth pressure regulator is provided on the lower end side of the spool valve element 288.
The line hydraulic pressure Pff is applied, and in the off state, that is, the open state, the pressure downstream of the throttle 292 is exhausted and the fourth
The line oil pressure P14 is not applied. Second
When the solenoid valve 268 is in the state shown on the ON side in the figure, the flow rate control valve 264 is in the operating position shown on the ON side in the figure, and when the second solenoid valve 268 is in the state shown on the OFF side in the figure, the flow rate control valve 264 is in the operating position shown on the OFF side in the figure. This is the operating position shown on the OFF side in the figure.

Therefore, during the period when the second electromagnetic valve 268 is in the on state (duty ratio is 100%), the spool valve 288 is positioned at the flow rate suppression side position, and the spool valve 288 is placed between the boat 286a and the boat 286b, and between the boat 286C and the boat 286C. 286d, but during the period when the second solenoid valve 268 is in the off state (duty ratio is 09A), the spool valve 288
is positioned at the flow rate suppression side position, resulting in a switching state opposite to the above.

The secondary hydraulic cylinder 56 includes a bypass oil passage 296 and a check valve 298 that are parallel to each other.
It is connected to the second line oil passage 82 via 95. The check valve 298 operates when the first line hydraulic pressure Pl+ is supplied to the secondary hydraulic cylinder 56 during a deceleration shift in which the pressure inside the secondary hydraulic cylinder 56 is set to a relatively high pressure side or during engine braking. Secondary hydraulic cylinder 56
A large amount of the hydraulic oil inside flows out to the second line oil passage 82, and the hydraulic pressure P inside the secondary hydraulic cylinder 56 decreases. ut (=Pρ) does not decrease, and during gradual deceleration shifting, the secondary hydraulic cylinder 56 is
This is to ensure that hydraulic oil is supplied inside.

Further, the throttle 296 and the check valve 298 suitably alleviate the pulsation that occurs in the hydraulic pressure P out in the secondary hydraulic cylinder in synchronization with the duty drive of the flow rate control valve 264 . That is, the hydraulic pressure P in the secondary hydraulic cylinder. This is because the spike-like upper peak in the pulsation of ut is released by the throttle 296, and the lower peak of PoutO is compensated for through the check valve 298. The check valve 298 includes a valve seat 299 having a flat seat surface, a valve 301 having a flat contact surface that comes into contact with the seat surface, and a valve seat 301 having a flat contact surface that comes into contact with the seat surface.
01 toward the valve seat 299
It is designed to open with a pressure difference of about 0.2 kg/C1+12.

In addition, in the − downstream oil passage 300, the second connection oil passage 272
A second throttle 273 is provided between the confluence point of the oil passage 305 and the branch point of the branch oil passage 305 . Here, the throttle 273 determines the speed at the time of rapid deceleration and shifting, and is set so that the speed is the maximum within a range in which slippage of the transmission belt 44 does not occur during rapid deceleration and shifting. Further, the aperture 271 and the aperture 296 are used to determine the speed at the time of slow speed increase, and the aperture 276 is used to determine the speed at the time of rapid increase.

Therefore, when the first solenoid valve 266 is on,
Regardless of the operating state of the second solenoid valve 268, the gear ratio γ of the CVT 14 is changed in the deceleration direction. For example, when the second solenoid valve 268 is in the on state, the hydraulic oil in the first line oil passage 80 flows into the boat 278e, the boat 27
8f, 3rd connection oilway 274, boat 286d, boat) 2
86c, the hydraulic oil in the downstream side hydraulic cylinder 54 flows into the secondary side hydraulic cylinder 56 through the secondary side oil path 302, and the hydraulic oil in the downstream side oil path 300, the boat 286a, the boat 286b, and the first connection oil. road 270, boat 278b,
It is discharged to the drain through the drain port 278a. As a result, the gear ratio γ is rapidly changed in the deceleration direction as shown in FIG. 11(a).

Further, when the second solenoid valve 268 is turned off while the first solenoid valve 266 is in the on state, the hydraulic oil in the second line oil passage 82 flows through the throttle 295 provided in parallel in the bypass oil passage 295. The hydraulic oil in the secondary hydraulic cylinder 54 is supplied through the check valve 298 into the secondary hydraulic cylinder 56, and the hydraulic oil in the downstream hydraulic cylinder 54 is supplied to the secondary hydraulic cylinder 54 through a small gap formed actively or inevitably in the sliding part of the piston. is gradually discharged through the As a result, (
As shown in c), the gear ratio γ is gradually changed in the deceleration direction.

Then, when the first solenoid valve 266 is in the on state, the second solenoid valve 266 is in the on state.
When the solenoid valve 268 is duty-driven, the above (
Since the speed change state is intermediate between (a) and (c), the speed ratio T is changed to the deceleration side at a speed corresponding to the duty ratio of the second electromagnetic valve 268.

FIG. 11(b) shows this state.

Conversely, when the first solenoid valve 266 is off, the second
Regardless of the operating state of the electromagnetic valve 268, the gear ratio T of the CVT 14 is changed in the direction of increasing speed (the direction of decreasing the gear ratio γ). For example, if the second solenoid valve 268 is turned on while the first solenoid valve 266 is off, the first solenoid valve 268 is turned on.
The hydraulic oil in the line oil passage 80 is supplied to the throttle 276 and the boat 27.
8C, boat 278b, I connection oilway 270, boat 2
86b, boat 286a, and flow into the primary hydraulic cylinder 54 through the downstream oil passage 300, as well as boat 278e, boat 278d, second connecting oil passage 272,
- The hydraulic oil in the secondary hydraulic cylinder 56 flows into the primary hydraulic cylinder 54 through the downstream oil passage 300, while the hydraulic oil in the secondary hydraulic cylinder 56 flows through the secondary oil passage 302, the boat 286C, the boat 286
d, third connection oilway 274, boat 278f, boat 27
8g and is discharged to the second line oil passage 82. As a result, the gear ratio γ is quickly changed in the direction of speed increase, as shown in (f) of FIG.

Furthermore, if the second solenoid valve 268 is turned off while the first solenoid valve 266 is off, the first connection oil passage 270 is closed by the flow rate control valve 264, so the first line oil passage The hydraulic oil in 80 is exclusively supplied to the primary side hydraulic cylinder 5 through the second connecting oil passage 272 equipped with the first throttle 271.
At the same time, the hydraulic oil in the secondary hydraulic cylinder 56 is gradually discharged to the second line oil passage 82 through the throttle 296. Therefore, by the action of the first throttle 271 and the throttle 296, the gear ratio γ is gently changed in the direction of speed increase, as shown in FIG. 11(D).

Then, when the first solenoid valve 266 is in the off state, the second solenoid valve 266
When the solenoid valve 268 is duty-driven, the above (
Since the speed change state is intermediate between (f) and (d), the speed ratio γ is changed to the speed increasing side at a speed corresponding to the duty ratio of the second electromagnetic valve 268.

(E) in FIG. 11 shows this state.

Here, the first line oil pressure P in CVTI4 is:
When running with positive drive (when driving torque T is positive), the desired oil pressure values are as shown in Figure 12, and when running with engine braking (when driving torque T is negative), the oil pressure values are desired as shown in Figure 13. A hydraulic value such as this is desired. Figures 12 and 13 both show the oil pressure values required when the gear ratio T is varied within the entire range with the input shaft 3o being rotated with a constant shaft torque. It is something. In this embodiment, since the pressure receiving areas of the negative hydraulic cylinder 54 and the secondary hydraulic cylinder 56 are equal, the hydraulic pressure P in the primary hydraulic cylinder 54 during normal drive running as shown in FIG. Oil pressure P in cylinder 56. ut, P during engine braking driving as shown in Fig. 13. ut>Pin, and in both cases, the hydraulic pressure in the driving side hydraulic cylinder>the hydraulic pressure in the driven side hydraulic cylinder. Since the above P in during normal drive running generates the thrust of the hydraulic cylinder on the driving side, it is necessary to make sure that the hydraulic cylinder can generate the thrust to obtain the target gear ratio γ, and to reduce power loss. In order to reduce the first line oil pressure P! 1 is desirably regulated to a value obtained by adding a necessary and sufficient margin oil pressure α to the above P1.

However, it is impossible to adjust the first line oil pressure pH shown in FIGS. 12 and 13 based on the oil pressure in one of the hydraulic cylinders. Therefore, in this embodiment, the first pressure regulating valve 100 is provided with a second plunge +148, so that an urging force based on whichever is higher of pin and second line oil pressure Pf2 is transmitted to the spool valve element 140 of the first pressure regulating valve 100. As a result, a curve indicating pin and P as shown in FIG. 14, for example. During no-load running, where the curve indicating ut intersects, the first line oil pressure Plt is controlled to a value obtained by adding the allowance value α to the higher oil pressure value of P or the second line oil pressure P2°. Thereby, the first line oil pressure P21 is controlled to a necessary and sufficient value, and power loss is minimized. Incidentally, the first line oil pressure Pi,' shown by the broken line in FIG. 14 is the one when the second plunger 148 is not provided, and an unnecessarily large surplus oil pressure is generated in a range where the gear ratio T is small. There is.

The margin value α is a necessary and sufficient value to change the gear ratio T at a desired speed within the entire gear ratio change range of the CVT 14 to obtain the desired gear ratio γ, and is clear from equation (2). As such, the first line oil pressure P1. is enhanced. Said first pressure regulating valve 100
The pressure receiving area of each part and the biasing force of the return spring 144 are set in this way. At this time,
The first line oil pressure P°C regulated by the first pressure regulating valve 100
, is pin or P as shown in FIG. u
It increases according to t and throttle pressure P, but is saturated at the maximum value corresponding to throttle pressure P. As a result, the oil pressure P4 in the primary hydraulic cylinder 54 is maintained in a state in which the gear ratio T becomes the minimum value and the decrease in the groove width of the primary variable boley 40 is mechanically prevented.
．． Even if the first line oil pressure Pj2. increases, the first line oil pressure Pj2. is designed to prevent excessive pressure rise.

Returning to FIG. 1, the hydraulic oil discharged from the boat 150b of the first pressure regulating valve 100 is guided to the lock-up clutch pressure oil passage 92, and is guided to the lock-up clutch pressure regulating valve 310.
The lock-up clutch hydraulic pressure P is suitable for operating the lock-up clutch 36 of the fluid coupling 12.
The pressure is regulated to ct. That is, the lock amplifier clutch pressure regulating valve 310 has a spool valve element 312 which is biased in the valve opening direction in response to the lock up clutch hydraulic pressure Pet as a feed bank pressure, and a spool valve element 312 which is biased in the valve closing direction. a spring 314 that operates, a chamber 316 to which throttle pressure P is supplied, and the chamber 3
The spool valve element 312 is actuated so that the thrust force based on the feedback pressure and the thrust force of the spring 314 are balanced. By causing the hydraulic oil in the lock-up clutch pressure oil passage 92 to flow out, a lock-up clutch oil pressure PET that increases in accordance with the throttle pressure Ptl is generated.

As a result, the lock-up clutch 36 is engaged with a necessary and sufficient engagement force according to the actual output torque of the engine 10. The above lock-up clutch pressure regulating valve 31
The hydraulic oil that has flowed out from the 0 is sent out through the throttle 318 and the lubricating oil passage 94 to lubricate each part of the transmission, and is also returned to the return oil passage 78.

The third electromagnetic valve 330 discharges pressure downstream of the throttle 331 to the drain in its OFF state, and has a signal pressure P that is the same pressure as the fourth line oil pressure PEa of the fourth line oil passage 370 in its ON state. , 3 is generated. Fourth solenoid valve 34
6 discharges pressure downstream of the throttle 344 to the drain in its off state, and in its on state, the fourth line hydraulic pressure P1. A signal pressure P5°, 4 of the same pressure as is generated. The linear valve 390 has a pressure reducing valve type valve mechanism, and as shown in detail in FIG. 16, the output signal pressure P is adjusted by regulating the fourth line oil pressure P14 as the source pressure. , L in the cylinder pore 39 of the valve pod 397.
8, a linear solenoid 392 that is excited by the driving current (control signal value) supplied from the electronic control device 460, and an excited state of this linear solenoid 392. In relation to this, the core 3 urges the spool valve element 391 toward the pressure increasing side.
93, a spring 394 that urges the spool valve element 391 toward the pressure reducing side, and a feedback oil chamber 395 to which the output signal pressure P6° is guided to urge the spool valve element 391 toward the pressure reducing side. . The above spool valve 391
is operated so as to move to a position where the biasing force applied from the core 393 toward the pressure increasing side and the biasing force applied from the spring 394 toward the pressure decreasing side are balanced.
Drive current I, supplied from electronic control unit 460 according to the output characteristics shown in FIG. , L based on the output signal pressure P,. .

change. In this way, the fourth line oil pressure Pi! ,
Signal pressure P8゜1.4 is regulated as the source pressure. is supplied from the output port 396 of the linear valve 390 to the boat 382b of the first relay valve 380.

In this embodiment, each of the signal pressures P, I3, P $014
,P. 4. By combining these, multiple types of control can be performed, including lock-up clutch engagement and release control, accumulator back pressure control, N range line oil pressure down control, line oil pressure down control at high vehicle speeds, and rehearse-in hip control, which will be described later. is now executed. Also,
The signal pressure P5° is also used to switch the speed change direction switching valve 262 to the deceleration side when the first solenoid valve 266 and the second solenoid valve 268 fail.

The cock-up clutch control valve 320 and the lock-up clutch quick release valve 400 related to engagement and release control of the lock-up clutch 36 will be explained. The cock-up clutch control valve 320 selectively directs the hydraulic oil in the oil passage 92 whose pressure is regulated to the lock-up clutch oil pressure PcL to the engagement side oil passage 322 and the release side oil passage 324 of the fluid coupling 12. The lock amplifier clutch quick release valve 400 supplies hydraulic oil that flows out when the lock up clutch 36 is released to an oil cooler 339.
The lock amplifier clutch 36 is quickly released by draining the water without passing it through.

The lock-up clutch control valve 320 is a two-position operating type spool valve, and when the lock-up clutch 36 is engaged (on side in the figure), the lock-up clutch hydraulic pressure Pcl is supplied to the boat 321C and the boat). 321
d, boat 321b and drain boat 321a, boat) 3
21e and the boat 321f to release the lock-up clutch 36 (off side in the figure), the boat 32
1c and boat) 321b, boat 321d and boat 321
e. It includes a spool valve 326 that communicates the boat 321f and the drain boat 321g, and a spring 328 that biases the spool valve 326 toward the release side (off side). Lower end surface side of spool valve 326 (non-spring 328
side), a signal pressure P, which is generated when the third solenoid valve 330 is in the on state. 5. A chamber 332 into which is introduced is provided.

The lock-up clutch quick release valve 400 is a two-position operating type spool valve, and includes a boat 402a that communicates with the clutch pressure oil passage 92 via a throttle 401, and a release side oil passage 32.
4, and a boat 402c that communicates with the boat 321b of the cock-up clutch control valve 320.
, the bow of the lock-up clutch control valve 320) 321f
A boat 402d that communicates with the engagement side oil passage 322, a boat 402e that communicates with the engagement side oil passage 322, and a cockup clutch control valve 320.
The boat 402f communicates with the boat 321d of
, the boat 402e and the boat 402f are communicated with each other, and at the time of sudden release (on side in the figure), the boat 402a and the boat 402
b. It includes a spool valve 406 that communicates the boat 402d and the boat 402e, and a spring 408 that urges the spool valve 406 toward the quick release side position. A signal pressure P so+,4 generated when the fourth magnetic valve 346 is in the on state is guided to the chamber 410 on the lower end side of the spool valve element 406 . As shown in the figure, the on-side and off-side positions of the third solenoid valve 330 and the on-side and off-side positions of the lock-up clutch control valve 320 are made to correspond operationally, and
The on-side and off-side positions of the fourth electromagnetic valve 346 and the on-side and off-side positions of the lock-up clutch quick release valve 400 are operatively made to correspond.

Therefore, when the third solenoid valve 330 is turned on while the fourth solenoid valve 346 is turned off, the spool valve 326 is placed in the on-side position shown in the figure, and the lock-up clutch 36 is engaged. Since a third oil passage is formed for this purpose, the hydraulic oil in the lock-up clutch pressure oil passage 92 is supplied to boats 1-321c, boats 321d, boats 402f, and boats 402e.

The hydraulic oil is supplied to the fluid coupling 12 through the engagement side oil passage 322 and flows out from the fluid coupling 12 through the release side oil passage 322.
4. Boat 402b, Boat 402C, Boat 321b
The water is then drained from the boat 321a. As a result, the lock-up clutch 36 is engaged.

Conversely, when the fourth solenoid valve 346 is in the OFF state, the third solenoid valve 346
When the solenoid valve 330 is turned off, the first oil passage for releasing the lock-up clutch 36 is formed, so that the hydraulic oil in the lock-up clutch pressure oil passage 92 is drained (Bo) 321c, Boat 321b1. Boat 402c, Boat 1
-402b, and the release side oil passage 324 to the fluid coupling 12, and the hydraulic oil flowing out from the fluid coupling 12 is supplied to the engagement side oil passage 322, the boat 402e, the boat 402f, the boat 321d, the boat 402e, and the oil cooler. 3
It is drained through 39. As a result, the first release mode is set, and the lock-up clutch 36 is released.

Furthermore, in this embodiment, when the third solenoid valve 330 and the fourth solenoid valve 346 are turned on, a fourth oil passage for releasing the lock-up clutch 36 is formed, so this second release In the mode, the hydraulic oil in the lock-up clutch pressure oil passage 92 is supplied to the fluid coupling 12 through the boat 402a, the boat 402b, and the release side oil passage 324, and the hydraulic oil flowing out from the fluid coupling 12 is on the engagement side. Oil road 322
, boat 402e, boat 402d, boat 321f1
The oil is drained through the oil cooler 321e and the oil cooler 339, and the lock-up clutch 36 is released. As a result, even if the spool valve element 326 of the lock-up clutch control valve 320 is stuck to the on side or the spool valve element 406 of the lock-up clutch quick release valve 400 is stuck to the off side, the first If the lock-up clutch 36 is maintained in the engaged state even if one of the release mode and the second release mode is selected, engine stall is prevented by switching to the other mode, and the vehicle is will be able to restart. In addition, the lock-up clutch control valve 32
0's spool valve 326 is stuck on the off side, or the spool valve 40 of the lock-up clutch quick release valve 400
6 is stuck on the on side and the lock-up clutch 36 is maintained in the sudden release state even if one of the first release mode or the second release mode is selected for the purpose of release. By switching to the other mode, the hydraulic oil can be drained through the oil cooler 339, and overheating of the oil can be suitably prevented.

When the lock-up clutch 36 is released as described above, when a sudden release is required as in the case of sudden braking of the vehicle, the fourth solenoid valve 346 is turned off while the third solenoid valve 330 is in the OFF state. is turned on. This allows the second clutch to release the lock-up clutch 36 quickly.
Since the oil passage is formed, the lock-up clutch pressure oil passage 9
The hydraulic oil in 2 is exclusively from boat 402a to boat 402b.
and flows into the fluid coupling 12 via the release side oil passage 324,
The hydraulic oil flowing out from the fluid coupling 12 flows through the engagement side oil passage 322,
The water is drained from boat 321g via boat 402e, boat 402d, and boat 321f. As a result, the oil is drained without passing through the oil cooler 339, which has a large flow resistance, so that the lock-up clutch 36 is quickly released. FIG. 18 shows the relationship between the mode of the lock-up clutch 36 and the operating states of the third solenoid valve 330 and the fourth solenoid valve 346.

Note that the oil cooler 339 is activated during engagement and disengagement.
The hydraulic oil that is returned to an oil tank (not shown) is relieved by a Tara hydraulic control valve 338 provided on the upstream side of the oil cooler 339, so that the pressure is regulated below a certain value. Furthermore, the bypass oil passage 334 guides a portion of the hydraulic oil to the oil cooler 339 in order to cool the hydraulic oil in the oil cooler 339 even while the lock amplifier clutch 36 is engaged.

The throttles 336 and 337 are connected to the lock-up clutch 36.
This is to set the proportion of hydraulic oil that is guided to the oil cooler 339 during engagement.

Next, the first relay valve 3 is related to accumulator back pressure control, line oil pressure down control in the N range, line oil pressure down control at high vehicle speeds, reverse inhibit control, etc.
80 and the second relay valve 440 will be explained. 1st
The relay valve 380 is connected to the second relay valve 440 (bow) 442
Boat 382a communicating with c, signal pressure P5°5. a boat 382b that is supplied with water, a boat 382c that communicates with the chamber 136 of the second pressure regulating valve 102 and the chamber 435 of the reverse inhibit valve 420, and a drain boat 382d;
b. A spool valve element 384 that communicates the boat 382c and the drain boat 382d, drains the boat 328a in the off-side state shown in the figure, and communicates the boat 382b with the drain boat 382c, and the spool valve element 384 in the off-side state. A signal pressure P is applied to a chamber 388 provided on the non-spring side of the spool valve element 384, and includes a spring 386 that biases the spool valve element 384 toward the spring 386. , 4 is not applied, the spool valve 384 is in the OFF position and the signal pressure P5 is
°1L is supplied to the chamber 136 of the second pressure regulating valve 102 and the chamber 435 of the rehearsing inhibit valve 420, but the
Signal pressure P at 8. , 4 is applied, the spool valve 384 is set to the on side and the signal pressure P is applied. 1.
is supplied to the boat 442c of the second relay valve 440.

In the figure, the on and off states shown for the first relay valve 380 correspond to the on and off states of the fourth solenoid valve 3460.

The second relay valve 440 includes boats 442b and 442c that communicate with the chamber 133 of the second pressure regulating valve 102 via the throttle 443 and are always in communication with each other, a boat 442d that communicates with the fourth pressure regulating valve 170, and a trenboat. 442e and
The boat 442d is communicated with the drain boat 442e in the on state shown in the figure, and the boat 442d is connected to the drain boat 442e in the off state shown in the figure.
42d and the train boat 442e, and a spring 446 that biases the spool valve 444 toward the off-side state, and is provided on the non-spring side of the spool valve 444. When the signal pressure P5°L3 is not applied to the chamber 448, the spool valve 444 is in the OFF position, and the signal pressure P5°L3 is applied to the chamber 448.
When 5oL3 is applied, the spool valve 444 is in the on-side position. As a result, boat 442
The chamber 133 of the second pressure regulating valve 102 through c and 442b
The signal pressure P, being supplied to. , but spool valve 44
4 is switched from the on to off position, the water is branched and also supplied to the chamber 177 of the fourth pressure regulating valve 170. In the figure, the on and off states shown for the second relay valve 440 correspond to the on and off states of the third solenoid valve 330.

Next, accumulators 342 and 340 are provided in the forward clutch 72 and the reverse brake 70, respectively.
Explain the back pressure control. The signal pressure P5oLL outputted by driving the linear valve 390 is changed in accordance with the drive current 15oLL as shown in FIG.
When the 11th J relay valve 380 is turned on and the second relay valve 440 is turned off for back pressure control, the oil is supplied to the fourth pressure regulating valve 170 via the oil passage 348.

Here, the back pressure control of the accumulators 340 and 342 is as follows:
Shift shock during N-D shift or N→R shift (
This is done to reduce the locking shock.When the clutch is engaged, the increase in the oil pressure in the hydraulic cylinder is suppressed for a predetermined period of time to reduce the shock.

Therefore, the fourth line oil pressure Pff, which is supplied to the back pressure boat 366 of the accumulator 342 for the forward clutch 72 and the back pressure boat 368 of the accumulator 340 for the reverse brake 70, is changed by the fourth pressure valve 170. Control the relaxation effect by accumulators 342, 340.

In the fourth pressure regulating valve 170, the fourth line oil pressure P! , is the signal pressure P,. , L is regulated.

That is, while the signal pressure P I+OLL is being supplied to the chamber 177 of the fourth pressure regulating valve 170 through the first relay valve 380 and the second relay valve 440 during the N-D shift and the N→R shift, the fourth line oil pressure is PN4 is the drive current of the linear valve 390. , the linear valve 390 is driven to generate a back pressure suitable for reducing shift shock (engagement shock). Further, as the oil pressure in the forward clutch 72 rises to the third line oil pressure PR3, the fourth pressure regulating valve 170
The signal pressure P5OLL supplied to the second relay valve 4
40 and the inside of the chamber 177 is opened to the atmosphere, the fourth line oil pressure Pf is relatively low, 4 kg/cm, corresponding to the biasing force of the spring 172 in the valve opening direction.
Controlled to a certain degree of pressure. The fourth line oil pressure P1 is regulated to this constant pressure. a is used exclusively as a driving oil pressure (pilot oil pressure) for the speed change direction switching valve 262 and the flow rate control valve 264. Therefore, in this example,
The fourth pressure regulating valve 170 functions as a valve drive oil pressure generating device that generates valve drive oil pressure for driving the speed change direction switching valve 262 and the flow rate control valve 264.

Next, the second line oil pressure Plz for compensating the centrifugal oil pressure
We will explain the parts related to the control of the decrease in .

Transmission belt 44 is activated by centrifugal hydraulic pressure in the low pressure side hydraulic cylinder.
In order to prevent overload from being applied to the fourth solenoid valve 346 and the first relay valve 380 in a high vehicle speed state,
When the linear valve 390 is turned off and the linear valve 390 is turned on, the output shaft 38 of the CVT 14 mainly operates in two directions during high-speed rotation, regardless of the operating states of the third solenoid valve 330 and the second relay valve 440. The second line oil pressure Pρ2 supplied to the next hydraulic cylinder 56 is lowered. That is,
When the signal pressure P -0LL (= P 1-) is supplied to the chamber 136 of the second pressure regulating valve 102 through the boats 382b and 382c of the first relay valve 380, the second line oil pressure Pf is determined according to the following equation (3). The pressure is regulated and lowered compared to the normal second line oil pressure. As a result, the influence of centrifugal oil pressure within the secondary hydraulic cylinder 56 is eliminated, and the durability of the transmission heald 44 is increased.

Such a second line oil pressure P! The lowering control in step 2 is also executed during reverse prohibition control, which will be described later, or when the shift lever 252 is operated to the N range. Note that when the fourth solenoid valve 346 is turned on or the linear valve 390 is turned off, the second line oil pressure PQ2 becomes the (1
) The route to school is controlled according to the formula.

Pβ2- (8,・P-10-A,・P,,-(A2-8,)・P,.15)/'(
A3 A2)... (3) The reverse inhibit valve 420, which is provided to prohibit reverse during forward travel, outputs the third line oil pressure Pβ3 from the output boat 256 when the manual valve 250 is in the R range. The boats 422a and 422b that are supplied, the boat 422c that communicates with the hydraulic cylinder of the reverse brake 70 via the oil passage 423, and the drain boat 422d, and the first boat that is the upper end of the movement stroke.
position (non-blocking position) and the second position which is the lower end (blocking position)
a spool valve 424 slidably disposed between the spool valve 424;
a spring 426 that urges the spool valve element 424 toward the first position in the valve opening direction;
Plunger 42 that abuts the lower end of 4 and has a smaller diameter than that.
8. The spool valve 424 has a first land 430 with a small diameter and a second land 430 with a larger diameter from its upper end.
A land 432 and a third land 434 having the same diameter as the land 432 are formed, and a signal pressure P 5oLL is supplied to a chamber 435 provided on the end surface side of the first land 430 through the first relay valve 380 in the OFF state. It has become so. The first land 43 of the spool valve 424 in the first position
0 and the second land 432, and the second land 4 of the spool valve 424, which is also in the first position.
32 and the third runt 434, a manual valve 25 is installed only when the R range is operated.
0 to the third line oil pressure P13 is applied, while the spool valve 424 and plunger 428
The hydraulic pressure in the reverse brake 70 is applied to the chamber 438 between the plunger 428 and the third line hydraulic pressure Pff is constantly supplied to the chamber 439 provided on the end face of the plunger 428. The pressure-receiving area on which the third line hydraulic pressure Pffi3 of the plunger 42B acts is determined by the difference in the pressure-receiving area between the first land 430 and the second land 432 of the spool valve 424, which receive the oil pressure in the chamber 436, and the gap between the passages and the like. ing.

The reverse inhibit valve 42 configured in this way
0 is the biasing force of the spring 426, the reverse brake force 0
Signal pressure P5゜1L and third line oil pressure P
When the thrust in the valve closing direction based on -422d is brought into communication, so the reverse brake 70 is released to the trunk, and establishment of the reverse gear of the forward/reverse switching device 16 is prevented. That is, when the fourth solenoid valve 346 is in the off state, the linear valve 390 is in the on state and the signal pressure P
When 3°1L is generated, the shift lever 252 moves to R.
On the condition that the range is being operated, establishment of the reverse gear of the forward/reverse switching device 16 is prevented. However, the rehearsing inhibit valve 420 cannot be used when the fourth solenoid valve 346 is turned on, when the linear valve 390 is turned off, or when the shift lever 252 is operated to a range other than the R range. When either one of them is performed, the spool valve element 434 is moved according to the biasing force of the spring 426, and the reverse brake 70 is brought into communication with the bow 256 of the manual valve 250. Therefore, if the shift lever 252 is erroneously operated from the D range, past the N range, and into the R range while the fourth solenoid valve 346 is in the OFF state and the linear valve 390 is in the ON state by the electronic control device 460, which will be described later. , the engagement of the reverse brake 70 is prevented and the forward/reverse switching device 16
is maintained in a neutral state.

The first relay valve 380 is in the off state, that is, the fourth solenoid valve 3
46 is in the off state, the signal pressure P 5oft-
is the chamber 1 of the second pressure regulating valve 102 through the first relay valve 380.
36, the second line oil pressure P12 is reduced by a predetermined pressure in accordance with the signal pressures P5° and L. As a result, in the N range, the clamping force on the transmission heald 44 is made as low as possible within a range that does not cause slippage, and in addition to reducing the noise level of the belt, the durability of the transmission belt 44 is increased.

Further, when the first relay valve 380, that is, the fourth solenoid valve 346 is in the on state, the signal pressure P8°L
Since L is supplied to the chamber 133 of the second pressure regulating valve 102 through the first relay valve 380 and the second relay valve 440, the second line oil pressure Pf2 is supplied to the linear valve 3 according to the following equation (4).
Signal pressure P, output from 90. 1. A predetermined correction is made based on L. As a result, accumulator back pressure can be controlled during sudden deceleration changes such as during sudden braking, when sudden deceleration changes are made by operating the shift lever 252 from the D range to the L range, and when the shift lever 252 is operated from the N range to the D or R range. At this time, the second line oil pressure Pβ2 is increased. Therefore, the transmission belt 4 of C T14 as described above
In a state where there is a risk of slippage of the transmission belt 4, the tension of the transmission heald 44 (the clamping force on the transmission belt 44) is temporarily increased to increase the torque transmission capacity.

P lz ” (Ai・Ptl, +(A4'-A4
)PsotL+W^,・p,) /(As−At)・・・・(4) FIG. 19 shows the above-mentioned third solenoid valve 330 and fourth solenoid valve 34.
6. The combinations of operations of the linear valve 390 and the resulting operation modes are shown, respectively.

Returning to FIG. 2, the electronic control device 460 controls the first solenoid valve 266 and the second solenoid valve 268 in the hydraulic control circuit of FIG.
, third solenoid valve 330, fourth solenoid valve 346, linear valve 39
By selectively driving 0, the gear ratio T of the CVT 14, the engaged state of the rotor up clutch 36 of the fluid coupling 12, the increase or decrease of the second line oil pressure P12, etc. are controlled.

The electronic control device 460 includes a so-called microcomputer consisting of a CPU, RAM, ROM, etc., and includes a vehicle speed sensor 462 that detects the rotational speed of the drive wheels 24;
An input shaft rotation sensor 464 and an output shaft rotation sensor 466 that detect the rotation speeds of the input shaft 30 and output shaft 38 of the CVT 14, respectively, and a throttle valve opening sensor that detects the opening of the throttle valve provided in the intake pipe of the engine 10. 468, an operation position sensor 470 for detecting the operation position of the shift lever 252, a brake switch 472 for detecting the operation of the brake pedal, an engine rotation sensor 47 for detecting the rotation speed N0 of the engine 10.
4. Output signal pressure P of linear valve 390. , L, a signal representing the vehicle speed SPD, a signal representing the input shaft rotational speed N in , and an output shaft rotational speed N. A signal representing ut, throttle valve opening θ5. , a signal representing the operation position P6 of the shift lever 252, a signal representing the brake operation, a signal representing the engine rotational speed N, an ON signal indicating that the pressure switch 476 has been turned on, and the pressure switch 476. OFF signal S indicating that the switch is turned off. ff are respectively supplied. The CPU in the electronic control unit 460 processes the human power signal according to a program stored in the ROM in advance while utilizing the temporary storage function of the RAM, and operates the first electromagnetic valve 266 and the second electromagnetic valve 266.
Solenoid valve 26th, third solenoid valve 330, fourth solenoid valve 346,
A signal for driving the linear valve 390 is output.

In the electronic control unit 460, initialization is executed when the power is turned on, and then a main routine (not shown) is executed to read input signals from each sensor, and input signals based on the read signals. The rotational speed N in of the shaft 30, and the rotational speed N of the 8-force shaft 38.

. ,, the gear ratio γ of the CVT 14, the vehicle speed SPD, etc. are calculated, and the lock amplifier clutch 3 is calculated according to the input signal conditions.
6 lock amplifier clutch engagement control and sudden release control,
C■T14 speed change control, accumulator back pressure control, reverse prohibition control, second line oil pressure reduction control, second line oil pressure increase control, solenoid fail control, etc. are executed sequentially or selectively.

Below, the operation of the electronic control unit 460 executed during the 19th normal driving in the C mode will be explained according to the flowchart of FIG.

In this operation, the second line oil pressure P2□ is changed to the ideal pressure P
. pt, and during the period when it is estimated that sufficient belt clamping force cannot be obtained with the optimal control because the viscosity of the hydraulic oil is high and control response and control accuracy cannot be obtained, the optimal control is performed. Block and 2nd line oil pressure P2□
is the basic output pressure P1. .

and controls.

In step S1 of FIG. 1, the input shaft rotational speed N i
n, output shaft rotational speed N. ut %engine speed N
9. After the vehicle state parameters such as the throttle valve opening θ are read, the actual gear ratio γ of the CVT 14 is determined to be the input shaft rotation speed N in and the output shaft rotation speed N. u
Calculated based on t. Next, in step S2, the actual input shaft rotational speed N in and output shaft rotational speed N are determined from the pre-stored relationship. The gear ratio T is calculated based on uL, and in step S3,
The output torque of the engine 10, in other words, the input torque T in of the CVT 14 is calculated based on the engine rotational speed N8 and the throttle valve opening θ from the pre-stored relationship shown in FIG. 20. In the subsequent step S4, the actual input torque T, 1 or throttle valve opening θ and vehicle speed SP are determined so that the engine 10 operates along an optimal curve determined in advance to obtain fuel efficiency and drivability.
A gear ratio control is executed to control the gear ratio T of the CVT 14 based on D, and one of the gear change modes shown in FIG. 11 is determined.

Further, it is determined whether a predetermined lock-up condition is satisfied based on the vehicle speed SPD, etc., and if the lock-up condition is satisfied, lock-up control for engaging the lock-up clutch 36 is executed.

Next, in step S5, based on the actual gear ratio T from the pre-stored relationship shown in FIG. , is calculated. In the subsequent step S6, the actual input torque T in and the actual applied diameter of the transmission belt 44 are determined to be 0. , and output shaft rotational speed N o u
Ideal pressure P based on t. pt is calculated.

Note that the second term on the right side of the following equation (5) is a correction term for centrifugal oil pressure, and the third term on the right side is a margin value. Also, C in the following formula (5)
5 and C2 are constants.

P opt =C+'Ti,,/Di-C2'
Nout" +ΔP・・・・・(5) Next, in step S7, the gear ratio pressure P is determined based on the hanging diameter D i I'l of the transmission belt 44 from the following equation (6).
.

is calculated.

P, =C3-D+, -C4・-= (6) However,
C3 and C4 are constants.

Then, in step S8, the ideal pressure P calculated in step S6 is determined. , , is greater than or equal to the gear ratio pressure P calculated in step S7. That is, the ideal pressure P op, , is the 22nd
Gear specific pressure P in FIGS. 24 to 24.

It is determined whether the area is located above the line indicating .

If the determination in step S8 is affirmative, step S10 determines the gear ratio pressure P in (8) 2, which will be described later.

The content of is replaced as the content of the gear ratio pressure P calculated in step S7. However, if the determination in step S8 is negative, then in step S9 the gear ratio pressure P is calculated using equation (8), which will be described later.

The content of is the ideal pressure P calculated in step S6 above. Replaced by pt.

In the subsequent step S11, the actual throttle valve function θ is calculated from a data map representing the relationship of the following equation (7) stored in advance.
In step 312, the gear ratio pressure P1 and the throttle pressure P
P sec is calculated based on th. Then, in step 313, the above value P is determined from the pre-stored relationship shown in the following equation (9). 0 and the ideal pressure P calculated in step S6. Linear valve 390 based on 9t
The output signal pressure P,. 5. is determined, step S1
4, the output signal pressure P5°1.4 is determined from the pre-stored relationship shown in FIG. The driving current value (value before correction) ■5°11° is determined to obtain the following.

P=M□(θi) ・ ・ ・ (7
)P,,c'=C9+C6-Pth-Ct-P.

・ ・ (8) P 5olL= CB (P see 'P
(9) Next, drive current value I determined as described above.

LL' is calculated as follows in order to obtain the above output signal pressure P go LL by dealing with individual differences and changes over time in the characteristics of the linear valve 390.
Corrections are made in steps S15 to 322 below.

First, in step S15, an on signal S is determined whether the output signal pressure P5OLL calculated in step S13 exceeds a preset pressure value P+ΔPd of the pressure switch 476. , and in step 316, the set pressure value p of the pressure switch 476, in which the output signal pressure P No (L is set in advance), -ΔP
The off signal S indicates whether or not the value has fallen below d. The determination is made based on the presence or absence of 11. The above set pressure values P SW + ΔP and P - ΔP are the hysteresis width 2 of the pressure switch 476.
A pair of operating values according to ΔPd, the output signal pressure P,.

4. When exceeds the set pressure value ps, 10ΔP4, the ON signal S is turned on. 1 is output from the pressure switch 476,
Output signal pressure P8゜1. is the set pressure value psw-ΔP.

, the off signal S01. is output from the pressure switch 476.

If the determination in step S15 is affirmative, in step S17 the pressure switch 476 sends an on signal S.
. It is determined whether or not 1 is output. If the judgment in step 317 is negative, the actual output signal pressure P5olL has not exceeded the set pressure value P5+ΔP4, so in step S18 the content of the correction parameter ΔI is kept constant at the previous value. Change value C4
is updated by adding, step 321
In step 31, one relationship is selected based on the above correction parameter ΔI from a plurality of relationships stored in advance for each correction parameter, and from this selected relationship, step 31 is performed.
The drive current value before correction determined in step 4 I5゜1. The current correction value 11 is determined based on . Then, in step S22, this current correction value Ih is changed to the drive current value r8°, L before correction obtained in step S13.
', the drive current value I5OLL is calculated, and in the following step S23, the drive current value I5OLL is calculated.
3° is output. Here, linear valve 390
Since the variation in the characteristics of the linear valve 390 increases as it approaches the center of the output range, the relationship used in step S21 is as shown in the frame of step 321 in FIG. Current value ■. 5. In the center of the changing region, the current correction value is largely determined.

While the above steps are repeatedly executed, the correction parameter Δ■ increases and the output signal pressure P of the linear valve 390 increases.

14 exceeds the set pressure value PSW+ΔP, the determination in step S17 is affirmed and step S21 is directly executed. That is, the ON signal S of the pressure switch 476
The correction parameter Δr is increased until ON occurs.

On the other hand, if the determination in step S15 is negative and the determination in step 316 is positive, in step 319 the pressure switch 476 outputs the off signal S07. It is determined whether or not is being output.

If the judgment in step S19 is negative, the actual output signal pressure P iol,L is equal to the set pressure value P sw - Δ
P.

Therefore, in step S20, the contents of the correction parameter ΔI are updated by subtracting a constant change value C1 from the previous value, and then
In step S21, one relationship is selected based on the above correction parameter ΔI from a plurality of relationships stored in advance for each correction parameter. As the above steps are repeatedly executed, the correction parameter Δt decreases and the output signal pressure of the linear valve 390 P5°1. When the pressure decreases below the set pressure Psw-ΔP4, the determination in step S19 is affirmed and step S21 is directly executed. That is, the off signal S of the pressure switch 476. The correction parameter ΔI is decreased until □ occurs.

Here, the step S8 is the ideal pressure P calculated in step S6. 9t is shown in Figures 22, 23, and 2.
This is for determining whether or not the gear ratio pressure P in FIG. Ideal pressure P.

When pt is located in the area above the diagonal line indicating the gear ratio pressure P, the content of Pl on the right side of equation (8) is taken as the actual gear ratio pressure P, so that the 22nd The value P IIec ' shown in the figure is obtained. This value P *ttc
' is the value P1 that the second pressure regulating valve 102 regulates according to equation (1) when the output signal pressure P mQ (L is not applied)
．． It is the same value as (=P,.C). Therefore, the second line oil pressure Pffz is changed from the above P-2 to the ideal pressure P. The output signal pressure P sot+-1 for lowering the voltage to □, that is, the output signal pressure P 5oLL for obtaining the voltage drop value (P----'Po-t) is calculated in step 5SI3, so that the ideal pressure P . This is done so that 2t can be obtained.

On the contrary, ideal pressure P. If pt is located in the area below the diagonal line indicating the gear ratio pressure P, then P on the right side of equation (8)
The content of 7 ゛ is the ideal pressure P. By being replaced with □,
The values P mQC shown in FIGS. 23 and 24 are obtained. This value P see ' is not located on a line parallel to the vertical axis corresponding to the value of the gear ratio γ at that time, such as the ideal pressure P 6pt, but is located on a diagonal line indicating the gear ratio pressure P. Ideal pressure P. It is located on a line parallel to the vertical axis passing through the intersection with a line parallel to the horizontal axis indicating P5oLL is required.

The output signal pressure P, obtained in this way. , 1- is
The ideal pressure P is obtained by lowering the value P□ on a line parallel to the vertical axis corresponding to the value of the gear ratio T at that time. This is a value to match pt. That is, in this embodiment, the pressure drop value (P,
, , '-P, pt), complex calculations are eliminated.

Moreover, since the calculation is simplified in this way, the calculation error caused by the computer is reduced, and the second line oil pressure P! 2
This has the advantage of improving pressure regulation accuracy.

In this way, in the second line pressure optimum control, the second
Basic output pressure P determined by the mechanical configuration of the pressure regulating valve 102
. ,. and the optimum control pressure P. □, in other words, the difference P,. ,,,take basic output pressure P1. . The electronic control unit 460 controls the linear valve 390 so that the second line oil pressure P12 reduced from
is the driving current value I. , L, the signal pressure P5 generated by the linear valve 390
゜, the second pressure regulating valve 102 adjusts the second line oil pressure P based on
By adjusting the pressure of N2, the second line pressure Plz can be made to match the ideal curve with high precision.

As described above, according to the present embodiment, in steps S15 to S21 corresponding to the control signal correction means, the output signal pressure P of the linear valve 390 is adjusted. , an on signal S from the pressure switch 476 that is activated based on a change in . 0 or off signal S. ff and the drive current value (control signal value) supplied to its linear valve 3901. . ,.

Based on the actual linear valve 390 output signal pressure P
5 (ILl, is the set pressure value P of the pressure switch 476
When the value corresponding to ΔPd or P-ΔP4 is reached, the pressure switch 476 is activated and the on signal S is activated. ,,
Or off signal S. Drive current value ■5°4 so that ff occurs. " is corrected. Therefore, the linear valve 39
Even if the output characteristics of the linear valve 390 change due to individual differences or changes over time, the drive current value supplied to the linear valve 390 ■5°1. Since the drive current value 15oLL is corrected so that the relationship between the linear valve 390 and the output signal pressure P1olL is stored in advance as shown in FIG. A decrease in the pressure regulation accuracy of the 2-line oil pressure P12 is prevented.

Although one embodiment of the present invention has been described above based on the drawings,
The invention also applies in other aspects.

For example, in the hydraulic control circuit of the above-mentioned embodiment, the 21st!
Basic output pressure P determined by the valve mechanism of the I pressure valve 102. C is the ideal pressure P. Output signal pressure P5 to reduce the pressure to pt
olL from the linear valve 390, the second line oil pressure Pj2. However, a pressure regulating valve configured similarly to the linear valve 390, such as a pressure control servo valve, may be configured to directly regulate the second line oil pressure Pit. In this case, the linear valve also serves as control oil pressure generating means.

Furthermore, although the above-mentioned embodiment was a hydraulic control device for a belt-type continuously variable transmission, it is also possible to use a linear valve to control line hydraulic pressure in a stepped automatic transmission (so-called A/T) equipped with multiple sets of planetary gears. It may also be a hydraulic control device of the type that uses the pressure control device to regulate the pressure.

The above-mentioned embodiment is merely one embodiment of the present invention, and various modifications may be made to the present invention without departing from the spirit thereof.

[Brief explanation of the drawing]

FIG. 1 is a flowchart illustrating the operation of the electronic control device shown in FIG. FIG. 2 is a schematic diagram showing a vehicle automatic transmission equipped with a hydraulic control device according to an embodiment of the present invention. FIG. 3 is a detailed circuit diagram of a hydraulic control system for operating the device of FIG. 2. Figure 4 is the second part of Figure 3.
It is a figure showing a pressure regulating valve in detail. FIG. 5 is a diagram showing the first pressure regulating valve of FIG. 3 in detail. FIG. 6 is a diagram showing the output characteristics of the throttle valve opening detection valve shown in FIG. 3. FIG. 7 is a diagram showing the output characteristics of the gear ratio detection valve shown in FIG. 3. FIG. 8 is a diagram showing the output characteristics of the second pressure regulating valve shown in FIG. 4. 9th
The figure is a diagram showing ideal characteristics of the second line oil pressure. 10th
The figure is a diagram illustrating the speed change control valve device of FIG. 3 in detail. FIG. 11 shows the first valve in the speed change control valve device shown in FIG.
3 is a diagram illustrating the relationship between the operating states of a solenoid valve and a second solenoid valve and the shift state of the CVT shown in FIG. 2. FIG. 12, 13, and 14 are diagrams for explaining the relationship between the gear ratio of the CVT shown in FIG. 2 and the oil pressure values of each part, and FIG. 12 shows the positive torque running state, and FIG. engine brake running condition,
FIG. 14 is a diagram showing the no-load running state. FIG. 15 is a diagram showing the output characteristics of the first pressure regulating valve of FIG. 5 with respect to the primary side hydraulic cylinder internal oil pressure or the second line oil pressure. FIG. 16 is a diagram illustrating in detail the configuration of the linear valve shown in FIG. 3. FIG. 17 is a diagram showing the output characteristics of the linear valve shown in FIG. 3. FIG. 18 is a diagram showing the correspondence between the combination of operations of the third solenoid valve and the fourth solenoid valve and the operating state of the lock-up clutch in the hydraulic circuit of FIG. 3. FIG. 19 is a diagram showing the correspondence between the combinations of operating states of the third solenoid valve, the fourth solenoid valve, and the linear valve and each control mode in the hydraulic circuit of FIG. 3. FIG. 20 is a diagram showing the relationship between the engine rotational speed, throttle valve opening, and CVT input torque used in FIG. 1. FIG. 21 is a diagram showing the relationship between the gear ratio and the hanging diameter of the primary variable pulley used in FIG. 1. Figures 22 1, 23, and 24 are
2A and 2B are diagrams each explaining the operation in FIG. 1. FIG. 14: CVT (vehicle automatic transmission) 44: Transmission belt (friction member) 102: Second pressure regulating valve (pressure regulating valve) 390: Linear valve 391 Nisbourg valve 476: Pressure switch Steps S15 to S22: Control signal correction means I5゜L
L: Drive current value (control signal value) P5゜ [L: Output signal pressure Applicant: Toyota Motor Corporation (2 others) 51 Yoney (Pso+c) Figure 4 ilt ratio r (small) Figure 6 Figure 7 Tatsu ratio (・1・) Friend ratio r (,1・) Figure 15 Figure 18 Cod Figure 17 Crocodile i'-Tan 3'? Ocrr, 1Etht', -':t
15otL (A) Figure 21: Change ratio r Figure 22, Figure 23; and 24@ Transmission ratio.

Claims (1)

[Scope of Claims] An automatic transmission in which power is transmitted via a friction member includes a pressure regulating valve that regulates basic oil pressure in order to apply a pressing force to the friction member in the automatic transmission, and a pressure regulating valve that regulates basic oil pressure in accordance with a control signal value. a linear valve that supplies an output signal pressure that continuously changes to the pressure regulating valve, and approximates the basic hydraulic pressure to the optimum hydraulic pressure by shifting the basic hydraulic pressure regulated by the pressure regulating valve. a pressure switch that generates an activation signal when the output signal pressure of the linear valve reaches a predetermined set pressure value; and a pressure switch that generates an activation signal when the output signal pressure of the linear valve reaches a value corresponding to the set pressure value. control signal correction means for correcting the control signal value based on the control signal value supplied to the linear valve and the actuation signal generated from the pressure switch so that the actuation signal is generated when the pressure switch is activated; Features: Hydraulic control system for vehicle automatic transmissions.