JPH04203666A - Hydraulic controller of belt type continuously variable transmission for vehicle - Google Patents

Abstract

PURPOSE:To prevent deterioration in the pressure regulating accuracy of control hydraulic pressure by determining a compensation value for compensating any output signal pressure in a linear valve, so as to solve a control deviation between the actual pressure detected by a hydraulic sensor and the optimum pressure, and storing it in a compensation value map. CONSTITUTION:In a step corresponding to a compensation value decision means 480 of a control program, a compensation value for compensating any output signal pressure in a linear valve 390 being calculated in accordance with a control expression, so as to solve a control deviation between the actual pressure detected by a hydraulic sensor 476 and the optimum pressure, is determined in response to the corrected value of fundamental hydraulic pressure and the optimum pressure, and the compensated value is stored in a compensation value map. Therefore, even if an output characteristic of the fundamental hydraulic pressure is varied by a solid difference in a second pressure regulating valve 102, the compensation value is determined in response to that, and stored in memory, so that any possible drop in the pressure regulating accuracy of control hydraulic pressure attributable to the solid difference or the like in the second pressure regulating valve 102 is prevented from occurring.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a hydraulic control device for a belt-type continuously variable transmission for a vehicle.

BACKGROUND OF THE INVENTION A belt-type continuously variable transmission for a vehicle in which the gear ratio is automatically changed is known. This belt-type continuously variable transmission is equipped with a transmission belt that transmits power by being wrapped around a pair of variable boots with a variable effective diameter, and is based on control oil pressure that is changed in relation to input torque etc. The clamping force of the transmission belt is generated by using the transmission belt.

For example, patent application No. 13448 filed earlier by the present applicant.
As described in No. 9, the belt-type continuously variable transmission has a pressure regulating valve that regulates the basic hydraulic pressure to apply clamping pressure to the transmission belt, and a pressure regulating valve that continuously changes the pressure according to a control signal value. It is equipped with a linear valve that supplies the output signal pressure to the pressure regulating valve and shifts the basic hydraulic pressure regulated by the pressure regulating valve, so that the difference between the basic hydraulic pressure and the optimum pressure calculated from the relationship stored in advance can be eliminated. In some cases, a hydraulic control device of the type that adjusts the output signal pressure of the linear valve is provided. In this type of hydraulic control device, the basic hydraulic pressure is regulated by the pressure regulating valve based on the throttle valve opening and the gear ratio, or the output signal pressure of the linear valve is shifted to match the optimum hydraulic pressure. Since a control oil pressure that is accurately set to the optimum oil pressure can be obtained, there are advantages in that power loss is suitably reduced and the durability of the transmission belt is improved.

Problems to be Solved by the Invention By the way, the pressure regulating valve provided in the above-mentioned hydraulic control device usually has a throttle pressure of a magnitude corresponding to the throttle valve opening output from the throttle opening detection valve and an output from the gear ratio detection valve. Since it is configured to generate basic oil pressure by operating based on the gear ratio pressure of a magnitude corresponding to the gear ratio, due to individual differences etc., the actual basic oil pressure or its calculated value may differ. In such a case, the accuracy of the control hydraulic pressure value for controlling the clamping force of the transmission belt may not be obtained.

The present invention has been made against the background of the above circumstances,
The purpose is to provide a hydraulic control device for a belt-type continuously variable transmission for vehicles in which the accuracy of regulating the control hydraulic pressure does not deteriorate due to individual differences in the pressure regulating valves that generate the basic hydraulic pressure. It is in.

Means for Solving the Problems The gist of the present invention for achieving the above object is to provide a belt-type continuously variable transmission for vehicles in which power is transmitted via a transmission belt, in which a clamping force is applied to the transmission belt. A pressure regulating valve that regulates the basic oil pressure based on the throttle pressure and gear ratio 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 pressure is regulated by the pressure regulating valve. It is equipped with a linear valve that shifts the applied basic oil pressure, and adjusts the output signal pressure of the linear valve according to a predetermined control formula to eliminate the difference between the basic oil pressure and the optimal pressure calculated from the pre-stored relationship. A hydraulic control device of the type that includes (a) a hydraulic pressure sensor that detects the hydraulic pressure regulated by the pressure regulating valve, and (b) a control deviation between the actual pressure detected by the hydraulic pressure sensor and the optimum pressure. A correction value for correcting the output signal pressure of the linear valve calculated according to the control formula is determined in correspondence with the basic oil pressure and the optimum pressure, and the correction value and a correction value determining means to be stored in the correction value map.

Operation and Effect of the Invention In this way, in the correction value determining means, the linear linear value calculated according to the control formula is adjusted so that the control deviation between the actual pressure detected by the hydraulic pressure sensor and the optimum pressure is eliminated. A correction value for correcting the output signal pressure of the valve is determined corresponding to the basic oil pressure and the optimum pressure,
Moreover, the correction value is stored in the correction value map. Therefore, even if the output characteristics of the basic oil pressure change due to individual differences in pressure regulating valves, a correction value is determined and stored accordingly, so that the accuracy of control oil pressure regulation due to individual differences in pressure regulating valves, etc. It is either reduced or prevented.

EXAMPLE Hereinafter, an example of the present invention will be described in detail with reference to the drawings.

In FIG. 2, the power of the engine IO 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 equal to or less than a predetermined value, hydraulic oil is supplied to the engagement side oil chamber 33 and hydraulic oil is flowed out from the release side oil chamber 35. The lock-up clutch 36 is engaged, and the crankshaft 26 and input shaft 30 are directly connected.

On the other hand, when the vehicle speed becomes less than a predetermined value, or when the rotational speed difference becomes more than 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 l4 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 hydraulic cylinder 54 and secondary hydraulic cylinder 56 that function as hydraulic actuators, thereby changing the V groove width, that is, the hanging diameter (effective diameter) of the transmission belt 44, and changing the gear ratio γ(
=rotational speed Nl of input shaft 30, /rotational speed N of output shaft 38. u+) is to be changed. Since the variable pulleys 40 and 42 have the same diameter, the hydraulic cylinders 54 and 56 have similar pressure receiving areas. usually,
The pressure in the driven one of the hydraulic cylinders 54 and 56 is related to the tension in the transmission belt 44.

The forward/reverse switching device 16 is a well-known double pinion 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. Advance switching device 1
A sun gear 66 that is fixed to the input shaft (output shaft of the CVT l4) 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 gear 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.
A forward clutch 72 is provided to connect the forward drive clutch 72 and the forward drive clutch 72. 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 38 of the CVTl 4
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. Also, the reverse brake 7
When 0 or 0 is 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 lock-up clutch pressure oil passage 92. The first line oil pressure pH 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.
By reducing the pressure of the second line oil pressure Pi2 in the second line oil passage 82, the pressure of the second line oil pressure Pi2 is regulated. Since this second line oil pressure P12 is regulated to control the tension of the transmission belt 44, it corresponds to the tension regulating 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 sea) 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.
Land 120 and third land 122 are formed in sequence.

A chamber 126 is provided between the second land 120 and the third land 122, into which the second line oil pressure PA2 is introduced as feedback pressure through the throttle 124, and the valve is closed by the spool valve 110 or the second line oil pressure P12. direction. In addition, spool valve 110
A chamber 130 is provided on the end surface side of the first land 118, 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. In 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 110 via the spring seat 112.
has been granted. Further, the plunger 116 is formed with a land 117 and a land 119 with a slightly larger diameter than the land 117, and a chamber 132 for applying a throttle pressure Plh, which will be described later, is provided on the end face side of the land 117. The spool valve element 110 is biased in the valve opening direction by this throttle pressure PIh.

Therefore, the pressure receiving area of the first land 118 is A1, and the pressure receiving area of the second land 118 is
Assuming that the cross-sectional area of the land 120 is A2, the cross-sectional area of the third land 122 is A3, the pressure receiving area of the land 117 of the plunger 116 is A4, and the biasing force of the return spring 114 is W, the spool valve 110 is calculated by the following formula. (1) is basically balanced at the position where (1) holds true. That is,
As the spool valve 110 is moved according to equation (1), the hydraulic oil in the first line oil passage 80 led to the boat 134a is transferred to the second line via the port 134b.
The state in which the oil is allowed to flow into the line oil passage 82 and the boat 134
The condition in which the hydraulic oil in the second line oil passage 82 led to the drain is repeatedly flowed to the drain boat 134C communicating with the drain is repeated, and the second line oil pressure P12 is generated. Since the second line oil passage 82 is a relatively closed system, the second pressure regulating valve 102 reduces the pressure of the first line oil pressure P l +, which is a relatively high oil pressure, as described above. Hydraulic PI! 2 is generated as shown in FIG.

Pff2-(A,・p, h+W A+・P,)
/(A3-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.
Through the signal pressure P,. A chamber 136 into which 1 L is introduced is provided, and the spool valve 110 or its signal pressure P. ,
When biased in the valve closing direction by L, the second line oil pressure P72 is reduced depending on the magnitude of the bias.

Furthermore, the runt 117 and land 1 of the plunger 116 are
19, a control pressure P is provided via the first relay valve 380, a second relay valve 440 (described later), and a throttle 135.

2nd line oil pressure PI by applying 1L! A pressure increasing oil chamber 133 for increasing the pressure of the second line oil pressure Pβ2 is increased in accordance with the signal pressure P8°IL. 2nd line oil pressure PI in the above case! The second characteristic will be explained in detail later.

As shown in FIG. 5, the first pressure regulating valve 100 includes a spool valve element 140, a spring seat 142, a return 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. Each has a plunger 148. The spool valve 140 opens and closes between the boat 150a and the drain boat 150b or 150c that communicate with the first line oil passage 80, and applies the first line oil pressure P as feedback pressure to the end surface of the first land 152. A chamber 153 is provided for applying i + through a throttle 151, and the spool valve element 140 is urged in the valve opening direction by this first line oil pressure PA. Spool valve 14
There is a throttle pressure p between the first land 154 and the second land 155 of the first plunger 146, which are provided coaxially with the
A chamber 156 is provided for guiding th, and
Between the second land 155 and the second plunger 148, there is a hydraulic pressure P1 within the primary hydraulic cylinder 54. ．． Branch oil path 30
A chamber 157 is provided for guiding the oil pressure through the second line hydraulic pressure P1.
A chamber 158 is provided for guiding 2. The biasing force of the return spring 144 is applied to the spring seat 14.
2, the pressure receiving area of the first land 152 of the spool valve 140 is A5, and the first land 15 of the first plunger 146 is
4, the cross-sectional area of the second land 155 and the second plunger 148 is A7, and the return spring 144 has a cross-sectional area of A6.
Let W be the biasing force of
) is established, and the first line oil pressure Pf is regulated.

PA+= ((P+nor PI 2) ” At+P+b(As
-A? )+W) /A5・・・・・(2) In the first pressure regulating valve 100, the negative side hydraulic cylinder 5
4 internal hydraulic pressure P1° is higher than the second line hydraulic pressure Pβ2 (in a steady state, PI2 - secondary hydraulic cylinder 56 internal hydraulic pressure P, ...), between the first plunger 146 and the second plunger 148. Separated from the above-next side hydraulic cylinder 54
If the thrust by the internal hydraulic pressure P1o acts in the valve closing direction of the spool valve element 140, or if the hydraulic pressure P0 in the -next side hydraulic cylinder 54 is lower than the second line hydraulic pressure P1□, the first plunger 146 and the second plunger 148, the thrust due to the second line hydraulic pressure PA'2 acting on the end face of the second plunger 148 causes the spool valve 140 to come into contact with the spool valve 140.
Acts in the direction of valve closing. That is, the second plunger 148, which receives the hydraulic pressure P1o in the next-side hydraulic cylinder 54 and the second line hydraulic pressure P12, applies an acting force based on the higher of these hydraulic pressures in the direction of closing the spool valve element 140. Let it happen. Note that the chamber 1 provided between the first land 152 and the second land 159 of the spool valve 140
60 is open to the drain.

Returning to FIG. 3, the throttle pressure Plh is the actual throttle valve opening θ1. is generated by the throttle valve opening detection valve 180. In addition, the gear ratio pressure Pr is the actual gear ratio γ of CVT14.
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);
A plunger 186 that engages with the cam surface of this cam 184 and is driven in the axial direction in relation to the rotation angle of this cam 184
and plunger 1 applied via spring 188.
Thrust from 86 and 1st line oil pressure PI! +, the first line oil pressure P I + is reduced, and the throttle pressure P1. The spool valve 190 generates a spool valve. FIG. 6 shows the throttle pressure Plh and the actual throttle valve opening θ5. The throttle pressures P and h are transmitted through the oil passage 84 to the first pressure regulating valve 100, the second pressure regulating valve 102, and the third pressure regulating valve 2.
20 and 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 l4 and is moved in the axial direction by an amount of displacement equal to the amount of displacement in the axial direction, and A spring 194 correspondingly transmits a biasing force, and while receiving the biasing force from this spring 194, the second line oil pressure Pi2 is received to position the two at a position where their thrusts are balanced, thereby reducing the discharge flow rate to the drain. The spool valve 198 changes the spool valve. Therefore, for example, the gear ratio γ becomes smaller and C
When the movable rotary body 50 approaches the fixed rotary body 46 on the input side of the VTl 4 (the V groove width is reduced), the detection rod 192
or being pushed into it. Therefore, the oil is supplied from the second line oil passage 82 through the orifice 196 and the spool valve 19
8 reduces the flow rate of the hydraulic oil discharged to the drain, thereby increasing the hydraulic pressure downstream of the orifice 196. This working oil pressure is the gear ratio pressure Pr, and the seventh
As shown in the figure, it is increased as the gear ratio γ decreases (changes to the speed increasing side). The gear ratio pressure Pr generated in this manner is supplied to the second pressure regulating valve 102 and the third pressure regulating valve 220 through the oil passage 86, 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 P12 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 PA7, the second pressure regulating valve 102, which operates according to equation (1) above, increases the second line oil pressure P12 as the gear ratio pressure Pr increases. reduce Therefore, when the gear ratio pressure Pr increases to a predetermined value and becomes equal to the second line oil pressure P 122 , both are saturated and become constant thereafter.

FIG. 8 shows the basic output pressure (maximum value of the second line oil pressure P12) p, 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. Shows output characteristics. In other words, 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 P69. Characteristics that are relatively close to the curve showing the curve can be obtained only by the valve mechanism. The second pressure regulating valve 102
The basic oil pressure P shown in FIG. 8 obtained by the valve mechanism shown in FIG. . teeth,
The spool valve 110 and plunger 1 of the second pressure regulating valve 102
It is a value determined mechanically in relation to the pressure receiving area etc. of 16,
Ideal pressure P so that sufficient clamping force can be obtained even during sudden speed changes. , is set higher than 1.

The third pressure regulating valve 220 generates an optimal third line hydraulic pressure PI23 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 22 that opens and closes between the first line oil passage 80 and the third line oil passage 88.
2. Spring seat 224, return spring 22
6, and a plunger 228. A chamber 236 is provided between the first land 230 and the second land 232 of the spool valve 222, and a chamber 236 is provided through which the third line oil pressure P73 or feedback pressure is introduced through the throttle 234. It is biased in the valve closing direction by the hydraulic pressure P l 2. Also, the gear ratio pressure Pr is on the first land 230 side of the spool valve 222.
A chamber 240 is provided in which the spool valve 2 is guided.
22 is biased in the valve closing direction by the gear ratio pressure Pr. In the third pressure regulating valve 220, the biasing force of the return spring 226 in the valve opening direction is applied to the spring seat 220.
24 to the spool valve element 222. Further, a chamber 242 for applying a throttle pressure P1h is provided on the end face of the plunger 228, and the spool valve element 222 is urged in the valve opening direction by the throttle pressure P1h. In addition, the plunger 228
a first land 244 and a second land 246 with a smaller diameter.
Between this and the 3rd line hydraulic pressure PI only when going backwards! A chamber 248 is provided for guiding . Therefore, the third line oil pressure P13 is regulated to an optimal value based on the gear ratio pressure Pr and the throttle pressure Plh using a formula similar to formula (1) 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. Also, when going backwards,
Since the third line oil pressure P13 is guided into the chamber 248, the force that urges the spool valve element 222 in the valve opening direction is increased, and the third line oil pressure Plz is increased.

As a result, the forward clutch 72 and the reverse brake 70 can each have torque capacities suitable for forward movement and reverse movement.

3rd line oil pressure P regulated as above! ! 3 is selectively supplied to the forward clutch 72 or the reverse brake 70 by a 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. In the state in which the third line hydraulic pressure P13 is exclusively output from the output port 258 and supplied to the forward clutch 72, the oil is allowed to drain from the reverse brake 70 to the drain. On the other hand, when the R (reverse) range is being operated, the third line oil pressure PA3 is output from the output boat 256.
422a and 422b of the reverse inhibit valve 420, and further supplies the oil to the reverse brake 70 through the reverse inhibit valve 420. At the same time, the oil is allowed to drain from the forward clutch 72. When the vehicle is in the parking range, the forward clutch 72 and reverse brake 70 are activated.
Both allow drainage of oil from. In addition, the accumulator 34
Reference numerals 2 and 340 are used to gradually increase hydraulic pressure to smoothly advance frictional engagement, and are connected to the forward clutch 72 and the reverse brake 70, respectively. Further, the shift timing valve 210 operates the throttle 2 in response to an increase in the hydraulic pressure in the hydraulic cylinder of the forward clutch 72.
By closing 12, the transient inflow flow rate is adjusted.

The first line oil pressure P z l regulated by the first pressure regulating valve 100 and the second line oil pressure P12 regulated by the second pressure regulating valve 102 are transmitted to the transmission control valve 100 to adjust the gear ratio γ of the CVT 14. The device 260 supplies 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 P14 for driving the speed change direction switching valve 262 and the flow rate control valve 264 is changed to the first line oil pressure P! by the fourth pressure regulating valve 170. ! 1, and is guided by 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 171 to introduce a fourth line hydraulic pressure PA to act as feedback pressure, while the spring of the spool valve 171 is 172
A chamber 177 is provided on the end surface side of the plunger 175 that contacts the side end portion of the plunger 175 to introduce a signal pressure P8°1L (described later) that acts in the valve opening direction, and the end surface of the spool valve element 171 on the non-spring 172 side is exposed to the atmosphere. It's open. In the fourth pressure regulating valve 170 configured in this way, the spool valve element 171 receives a biasing force in the valve closing direction based on the feedback pressure corresponding to the fourth line oil pressure P14, a biasing force in the valve opening direction by the spring 172, and a signal. As a result of being operated so that the biasing force in the valve opening direction based on the pressure P8°1L is balanced, the fourth line oil pressure Pf.

is the signal pressure P, which will be described later. The pressure is regulated to a value corresponding to the size of 1L.

As shown in detail in FIG. 10, the speed change direction switching valve 262 is a spool valve controlled by a first electromagnetic valve 266, and has a drain port 278a communicating with a drain and a first
Ports 278b, 278d, and 278f communicate with a connecting oil passage 270, a second connecting oil passage 272 with a first throttle 271, and a third connecting oil passage 274, respectively;
Line hydraulic pressure PI! + is supplied through the throttle 276 to the port 278c, and the first line oil pressure P1. port 278e to which the pressure is supplied, port 278g to which the second line hydraulic pressure P12 is supplied, and the deceleration side position (on side position) which is one end of the movement stroke (upper end in the figure) and the other end of the movement stroke (the upper end in the figure). (lower end) is the speed increasing side position (off side position)
a spool valve 28 slidably disposed between
0, and a spring 282 that biases the spool valve element 280 toward the speed increasing position. The spool valve element 280, which functions as a speed change direction switching valve element, has four
Three lands 279a, 279b, 279c, and 279d are provided. The end surface of the spool valve element 280 on the spring 282 side is open to the atmosphere. However, on the end surface of the lower end side of the spool valve element 280, the first electromagnetic valve 266
When the first electromagnetic valve 266 is in the on state, that is, in the closed state, the fourth line hydraulic pressure PA regulated by the fourth pressure regulating valve 170 is applied, and when the first solenoid valve 266 is in the off state, that is, in the open state, it is on the downstream side of the throttle 284. The pressure is exhausted and the 4th line oil pressure P1
4 cannot be applied. When the first solenoid valve 266 is in the state shown on the ON side in the figure, the shift direction switching valve 262
is in the position shown on the ON side in the figure, and when the first solenoid valve 266 is in the state shown in the OFF side in the figure, the shift direction switching valve 262
This is also the position shown on the OFF side in the figure. For this reason,
During the period when the first solenoid valve 266 is in the ON state, the spool valve element 280 is positioned at the deceleration side position and the drain port 280
78a and port 278b, port 278e and port 278f, and ports 278b and 2780, ports 278d and 278e.
and between the ports 278f and 278g are closed or the first solenoid valve 266 is in the OFF state, the spool valve element 280 is positioned at the speed increasing side position and the switching state opposite to the above is established. becomes.

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
6゜1. A deceleration oil chamber 283 is provided in which the spool valve element 280 generates a thrust in a direction toward the deceleration side position by receiving the oil through an oil passage 285. This signal pressure P.

1L is also used to switch the speed change direction switching valve 262 to the deceleration side when the solenoids S1 and S2 of the first solenoid valve 266 and the second solenoid valve 268 fail.

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 port 286a that communicates with the connection oil passage 272, ports 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.
Port 28 communicates with secondary hydraulic cylinder 56 via
6c, and the flow rate non-suppressing side position in the increasing speed change mode, which is one end 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). It includes a spool valve element 288 that is slidably disposed, and a spring 290 that urges 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 ports. Similar to the speed change direction switching valve 262, the end surface of the spool valve element 288 on the spring 290 side is open to the atmosphere, and therefore no hydraulic pressure is applied thereto. However, when the second electromagnetic valve 268 is in the on state, that is, in the closed state, the fourth line hydraulic pressure P14 regulated by the fourth pressure regulating valve 170 is applied to the lower end surface of the spool valve element 288, and in the off state, That is, in the open state, the pressure downstream of the throttle 292 is exhausted and the fourth line oil pressure P l 4 is not applied. When the second 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 in the OFF side in the figure, the flow rate control valve 264 is the operating position shown on the OFF side in the figure.

Therefore, during the period when the second solenoid valve 268 is in the on state (duty ratio is 100%), the spool valve 288 is positioned at the flow rate non-suppression side position, and the port is closed between the port 286a and the port 286b. 286C and 286d are respectively opened, or the second solenoid valve 268 is in the OFF state (
During the period when the duty ratio is 0%), the spool valve is 288
or to 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 is activated when the first line hydraulic pressure Pl is supplied to the secondary hydraulic cylinder 56 during deceleration shifting or engine braking when the pressure inside the secondary hydraulic cylinder 56 is relatively high. , secondary hydraulic cylinder 56
A large amount of the hydraulic oil inside the cylinder leaks into the second line oil passage 82, and the hydraulic pressure P inside the secondary hydraulic cylinder 56 decreases. . , (=Pj?,), and to prevent the second line oil pressure P! from decreasing during gradual deceleration shifting. This is to allow hydraulic oil to be supplied from 2 to the secondary side hydraulic cylinder 56. Further, the throttle 296 and the check valve 298 suitably alleviate pulsations occurring in the hydraulic pressure P01 in the secondary hydraulic cylinder in synchronization with the duty drive of the flow 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 1 is escaped by the throttle 296, and the lower peak of Paul is compensated for through the check valve 298. The check valve 298 includes a valve seat 299 having a flat seating surface, a valve 301 having a flat contacting surface that comes into contact with the seating surface, and the valve 301.
A spring 303 urges the valve toward the valve seat 299, and the valve is opened with a pressure difference of about 0.2 kg/C [n2.

Further, in the − downstream oil passage 300, the second connection oil passage 272
A second throttle 273 is provided between the confluence point and the branch point of the branch oil path 305. Here, the throttle 273 determines the speed at the time of rapid deceleration and shifting, and is set so that the maximum speed is achieved within a range where only the edge of the transmission belt 44 occurs during the rapid deceleration and shifting. Further, the aperture 271 and the aperture 296 determine the speed at the time of slow speed increase, and the aperture 276 determines 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, CVTl 4
The gear ratio γ is changed in the direction of deceleration. For example, when the second solenoid valve 268 is in the ON state, the hydraulic oil in the first line oil passage 80 is
78f, third connection oil passage 274, port 286d, port 286c, and secondary oil passage 302 to flow into the secondary hydraulic cylinder 56;
The hydraulic oil inside is the downstream side oil passage 300, port 286a, port 286b, first connection oil passage 270, bow) 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 296 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 secondary hydraulic cylinder 54 is supplied to the secondary hydraulic cylinder 54 through a small gap intentionally or inevitably formed in the sliding portion 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 turned on.
When the solenoid valve 268 is duty-driven, 1. Since the speed change state is intermediate between (a) and (c) in F, the speed ratio γ is changed to the deceleration side at a speed corresponding to the duty ratio of the shell 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 γ of the CVTl4 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 flows through the throttle 276 and the port 27.
8c1 port 278b, first connection oil passage 270, port 2
86b, bow) 286a, - is caused to flow into the primary side hydraulic cylinder 54 through the downstream side oilway 300, and the port 278e1 port 278d, the second connecting oilway 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, port 286c, port 28
6d, is discharged to the second line oil passage 82 through the third connection oil passage 274, port 278f, and port 278g. As a result, the gear ratio γ is quickly changed in the speed increasing direction, as shown in FIG. 11(f).

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 gradually 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 P11 in the CVT 14 is:
When running with positive drive (when drive torque T is positive), the desired oil pressure value is as shown in Figure 12, and when running with engine braking (when drive torque T is negative), the oil pressure value is as shown in Figure 13. A hydraulic pressure value like this is desired. Figures 12 and 13 both show the oil pressure values required when the gear ratio γ is varied within the entire range with the input shaft 30 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, during normal drive running as shown in FIG. During engine braking driving as shown in FIG. 13, Pout > p, and in both cases, the hydraulic pressure in the driving side hydraulic cylinder > the hydraulic pressure in the driven hydraulic cylinder. The above P during forward drive running. Since this generates the thrust of the hydraulic cylinder on the driving side, the first line is designed so that the hydraulic cylinder can generate the thrust necessary to obtain the target gear ratio γ, and to reduce power loss. It is desired that the oil pressure P R+ be regulated to a value obtained by adding a necessary and sufficient margin oil pressure α to the above p , .

However, the first line oil pressure Pj7. shown in FIGS. 12 and 13 above. It is impossible to adjust the pressure based on the oil pressure in one hydraulic cylinder. Therefore, in this example,
The first pressure regulating valve 100 is also provided with a second plunger 148, and a biasing force based on whichever is higher of Pln and second line hydraulic pressure P12 is transmitted to the spool valve element 140 of the first pressure regulating valve 100. It looks like this. As a result, during no-load running when the curve indicating Plo and the curve indicating P out intersect, for example, as shown in FIG. It is controlled to a value that is the sum of the high oil pressure value and the margin value α. Thereby, the first line hydraulic pressure pH 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. +' is the case where the second plunger 148 is not provided, and an unnecessarily large excess oil pressure is generated in a range where the gear ratio γ is small.

The margin value α is a necessary and sufficient value to change the gear ratio γ at a desired speed within the entire gear ratio change range of the CVTI 4 to obtain the desired gear ratio γ, and is clear from equation (2). So, the first in relation to the throttle pressure p + h
Line oil pressure PA' is increased. Pressure receiving area of each part of the first pressure regulating valve 100 and return spring 14
The biasing force of 4 is set as such. At this time, the first line oil pressure pH regulated by the first pressure regulating valve 100 is P, as shown in FIG. Or P.

, 1 and the throttle pressure Plh,
It is designed to be saturated at a maximum value corresponding to the throttle pressure Plh. As a result, even if the oil pressure Pln in the primary hydraulic cylinder 54 increases while the speed ratio γ reaches its minimum value and the V groove width of the primary variable pulley 4o is mechanically prevented from decreasing, the The first line oil pressure pH, which is always controlled to be higher by the margin value α, is prevented from being excessively increased.

Returning to FIG. 3, the hydraulic oil flowing out from the port 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 31.
The lock-up clutch oil pressure P has a pressure suitable for operating the pull-up clutch 36 of the fluid coupling 12 by 0. The pressure is regulated to . That is, the lock-up clutch pressure regulating valve 310 uses the lock-up clutch oil pressure P as the feedback pressure. 1 and a spring 314 that urges the spool valve element 312 in the valve-closing direction.
, a chamber 316 to which the throttle pressure P1b is supplied, and a plunger 317 that receives the oil pressure in the chamber 316 and urges the spool valve element 312 in the valve closing direction. Based on this, the lock-up clutch oil pressure p increases in accordance with the throttle pressure P5. Generate cl.

As a result, the lock-up clutch 36 is engaged with a necessary and sufficient engagement force corresponding 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 transmission 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.

Third, the shell 330 discharges pressure downstream of the throttle 331 in its OFF state, and generates a signal pressure P8°13 having the same pressure as the fourth line oil pressure P14 in the fourth line oil passage 370 in its ON state. . Fourth solenoid valve 346
In its OFF state, the pressure on the downstream side of the throttle 344 is exhausted, and in its ON state, the fourth line oil pressure P
1. A signal pressure P6°14 of the same pressure is generated. The linear valve 390 has a pressure reducing valve type valve mechanism, and the first
As shown in detail in FIG. 6, the cylinder pore 39 of the valve body 397 is used to generate the output signal pressure PgollL by regulating the fourth line oil pressure Pβ4 as the source pressure.
8, a linear solenoid 392 excited by a drive current (control signal value) 8° 1L supplied from an electronic control device 460, and a linear solenoid 392 that is Core 39 that biases spool valve element 391 toward the pressure increasing side in relation to the excitation state
3, a spring 394 that biases the spool valve element 391 toward the pressure reducing side, and a feedback oil chamber 395 into which the output signal pressure P6°1L is guided to bias 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.
The drive current (2) is supplied from the electronic control unit 460 according to the output characteristics shown in FIG. Output signal pressure P, based on IL. Change IL. The signal pressure P is thus regulated using the fourth line oil pressure P14 as the source pressure. 1L is
From the output boat 396 of the linear valve 390 to the first relay valve 3
80 ports) 382b.

In this embodiment, each of the above signal pressures P8°13, P8°+4,
By combining P6゜1, multiple types of control such as lock-up clutch engagement and sudden release control, accumulator back pressure control, N range line oil pressure reduction control, line oil pressure reduction control at high vehicle speeds, and reverse inhibit control, which will be described later, can be performed. is now executed. Further, the signal pressure P6°IL is applied to the speed change direction switching valve 26 when the solenoid of the first solenoid valve 266 and the second solenoid valve 268 fails.
2 to the deceleration side.

The lock-up clutch control valve 320 and lock-up clutch quick release valve 400 related to engagement and quick release control of the lock-up clutch 36 will be described. The lock-up clutch control valve 320 controls the hydraulic oil in the oil passage 92 whose pressure is regulated to the lock-up clutch oil pressure pel to the engagement side oil passage 322 and release side oil passage 3 of the fluid coupling 12.
The lock-up clutch 36 is selectively supplied to the lock-up clutch 24 to engage or disengage the lock-up clutch 36, and the lock-up clutch quick release valve 400 supplies the hydraulic oil that flows out when the lock-up clutch 36 is released to an oil cooler. By draining water without passing through 339, the lock-up clutch 36 is quickly released.

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), a port 321c and a port 321d are supplied with the lock-up clutch hydraulic pressure Pc1.
, boat h321b and drain boat 321a, port 32
1e and the port 321f to release the lock-up clutch 36 (off side in the figure), the boat 321
c and boat) 321b, boat 321d and port 321e
, a spool valve 326 that connects the boat 321f and the drain port 321g, and a spool valve 326 that connects the spool valve 326 to the release side (
(off side).

A signal pressure P is generated on the lower end surface side (non-spring 328 side) of the spool valve element 326 when the third solenoid valve 330 is in the on state. A chamber 332 into which 13 is introduced is provided.

The lock-up clutch quick release valve 400 is a two-position operating type spool valve, and includes a port 402a communicating with the clutch pressure oil passage 92 via a throttle 401, and a release side oil passage 32.
4 communicates with the boat 321b of the lock-up clutch control valve 320, and the boat 402c communicates with the boat 321b of the lock-up clutch control valve 320.
, boat 321f of lock-up clutch control valve 320
A ski boat 402d that communicates with the engagement side oil passage 322, a ski boat 402e that communicates with the engagement side oil passage 322, and a lock-up clutch control valve 320
The boat 402f communicates with the port 321d of
, port 402e and port 402f are communicated, and when suddenly released (on side in the figure), the above-mentioned bow) 402a and bow) 402
b, a spool valve element 406 that communicates port 402d with port 402e, and a spring 408 that biases this spool valve element 406 toward the quick release position. The chamber 4IO on the lower end side of the spool valve element 406 has a signal pressure P generated when the fourth solenoid valve 346 is in the on state. 14 or so. 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 fourth
The on-side and off-side positions of the solenoid 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, if the third solenoid valve 330 is turned on while the fourth solenoid valve 346 is off, the spool valve 326 is placed in the position shown on the on side in the figure, and the lock-up clutch 36 is engaged. Since a third oil passage is formed to allow the hydraulic oil to flow, the hydraulic oil in the lock-up clutch pressure oil passage 92 is connected to the boat 321c, the boat 321a, the port 402f, and the port 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, port 402C, boat 321b
The water is drained from 321a (Bo) 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 (boat 321c, boat 321b, boat) 402c, boat 4
02b, and the fluid coupling 12 through the release side oil passage 324.
The hydraulic oil flowing out from the fluid coupling 12 is supplied to the engagement side oil passage 322, boat 402e, port 402f, boat)
321d, port 402e, and oil cooler 339
It is drained after 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 402a, 1-402b,
Hydraulic oil is supplied to the fluid coupling 12 through the release side oil passage 324 and flows out from the fluid coupling 12 through the retention side oil passage 324.
2. Port 402e, Port 402d, Port 321f
, port 321e, and 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 3
If the spool valve 326 of the lock-up clutch 20 is stuck on the off side or the spool valve 4 of the lock-up clutch quick release valve 400
06 is stuck on the on side, and even if one of the first release mode or the second release mode is selected for the purpose of release, the lock-up clutch 36 is maintained in the sudden release state. 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, if a sudden release is required such 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. or 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 port 402a to port 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,
It is drained from port) 321g via port) 402e, port 402d, port) 321f. As a result, the oil is drained without passing through the oil cooler 339, which has a large flow resistance, and 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
The hydraulic oil that is returned to an oil tank (not shown) is relieved by a cooler oil pressure control valve 338 provided upstream of the oil cooler 339, so that the pressure is regulated below a certain value. Further, 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 when the lock/up clutch 36 is engaged. The throttles 336 and 337 are connected to the lock-up clutch 3.
This is for setting the proportion of hydraulic oil guided to the oil cooler 339 during the engagement of No. 6.

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 port 442 of the second relay valve 440.
port 382a, signal pressure P, communicating with c. 1. port 382b to which is supplied, port 382c communicating with chamber 136 of second pressure regulating valve 102 and chamber 435 of reverse inhibit valve 420, and drain boat 382d;
, communicate the port 382c and the drain port 382d,
A spool valve element 384 that drains the port 328a and communicates the ports 382b and 382c in the off-side state shown in the figure, and a spring 386 that biases the spool valve element 384 toward the off-side state,
Chamber 3 provided on the non-spring side of the spool valve 384
Signal pressure P at 88. When the spool valve 384 is not operated, the spool valve 384 is set to the OFF position and the signal pressure P6°, L is supplied to the chamber 136 of the second pressure regulating valve 102 and the chamber 435 of the reverse inhibit valve 420,
When the signal pressure P6°14 is applied to the spool valve 384, the spool valve 384 is set to the on side and the signal pressure P8°1. or is supplied to port 442c of 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 346.

The second relay valve 440 communicates with the chamber 133 of the second pressure regulating valve 102 via the throttle 443, and a port 442b and 442C1, which communicate with each other at all times, a port 442d and a dormant port 442e, which communicate with the fourth pressure regulating valve 170. ,
The port 442d is communicated with the Dorn port 442e in the on state shown in the figure, and the port 442d is communicated with the door port 442e in the off state shown in the figure.
42d and Dornpo) 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 P6.13 is not applied to the chamber 448, the spool valve 444 is in the off position, and the signal pressure P is applied to the chamber 448.
When 8 degrees and 3 degrees are applied, the spool valve 444 is in the on side position. This allows Bo) 442c
Whether the signal pressure P8°1L is supplied to the chamber 133 of the second pressure regulating valve 102 through 442b or the spool valve 44
4 is switched from the on position to the off position -\, so that it 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 P6°1L output by driving the linear valve 390 is changed in accordance with the drive current I6°IL as shown in FIG. When the second relay valve 440 is turned on and the second relay valve 440 is turned off, the oil passage 34
8 to the fourth pressure regulating valve 170.

Here, the back pressure control of the accumulators 340 and 342 is as follows:
This is done to reduce the shift 1 shock (engagement shock) at the time of N→D shift or N4R shift, and suppresses the increase in the hydraulic pressure in the hydraulic cylinder for a predetermined period of time when the clutch is engaged to alleviate the shock.

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

In the fourth pressure regulating valve 170, the fourth line oil pressure P14 or the signal pressure P. The pressure is regulated to correspond to 1L.

That is, the signal pressure P is passed through the first relay valve 380 and the second relay valve 440 during the N-D shift and the N+R shift. 1. The fourth line oil pressure PI! is being supplied to the chamber 177 of the fourth pressure regulating valve 170. 4 is linear valve 3
90 drive current I8°1. Since the linear valve 390 is controlled to a value corresponding to the shift shock (locking shock), the linear valve 390 is driven to generate a back pressure suitable for reducing shift shock (locking shock). Also, by increasing the oil pressure in the forward clutch 72 to the third line oil pressure Pi3, the fourth pressure regulating valve 170
The signal pressure P8°, L supplied to the second relay valve 44
When it is shut off by 0 and opened to the inside of the chamber 177 or to the atmosphere,
The fourth line oil pressure Pf is controlled to a relatively low constant pressure of about 4 kg/cm 2 in response to the biasing force of the spring 172 in the valve opening direction. The fourth line oil pressure P14 regulated to a constant pressure is exclusively used by the shift direction switching valve 26.
2 and as a drive oil pressure (pilot oil pressure) for the flow rate control valve 264. Therefore, in this embodiment, 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 Pβ2 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 at high vehicle speeds,
When the output shaft 38 of the CVT 14 is in the off state and the linear valve 390 is in the on state, regardless of the operating states of the third solenoid valve 330 and the second relay valve 440, the output shaft 38 of the CVT 14 mainly receives the secondary hydraulic pressure during high-speed rotation. The second line oil pressure P72 supplied to the cylinder 56 is reduced. That is, the signal pressure P8°, L (=Pβ4) is applied to the second pressure regulating valve 102 through the ports 382b and 382c of the first relay valve 380.
When the second line oil pressure P12 is supplied to the chamber 136, the second line oil pressure P12 is regulated according to the following equation (3), and is lowered compared to the normal second line oil pressure. As a result, the secondary hydraulic cylinder 5
The influence of centrifugal oil pressure in the transmission belt 44 is eliminated, and the durability of the transmission belt 44 is increased.

Such a reduction control of the second line oil pressure P12 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 P12 becomes the (1)
) is controlled as usual according to Eq.

Pi2= (A,・p,h+w −AI−p, (A2 AI)・P,.,L) /
(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 port 256 of the manual valve 250 when it is in the R range. is supplied to ports 422a and 422b, a port 422c communicates with the hydraulic cylinder of the reverse brake 70 via an oil passage 423, and a drain port 422d.
position (non-blocking position) and the second position which is the lower end (blocking position)
a spool valve 424 slidably arranged between the spool valve 424 and the spool valve 424;
A spring 426 that biases the spool valve element 424 in the valve opening direction toward the first position;
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 P5°IL is supplied to a chamber 435 provided on the end face side of the first land 430 through a first relay valve 380 in an OFF state. It is now possible to do so.

First land 430 of spool valve 424 in first position
and the second land 432, and the second land 43 of the spool valve 424, which is also in the first position.
In the chamber 437 located between the second and third lands 434,
Manual valve 250 only when operated to R range
While the third line hydraulic pressure PA3 is applied to the chamber 438 between the spool valve element 424 and the plunger 428, the hydraulic pressure in the reverse brake 70 is applied to the end face of the plunger 428. A third line hydraulic pressure P II s is constantly supplied to a chamber 439 provided in the chamber 439 . Note that the pressure receiving area on which the third line hydraulic pressure P II 'J of the plunger 428 acts is the first land 430 and the second land 43 of the spool valve element 424.
2 is the pressure receiving area difference that receives the oil pressure in the chamber 436, the road gap, etc.

The reverse inhibit valve 42 configured in this way
0 is the biasing force of the spring 426, the reverse brake 70
signal pressure P, than the thrust in the valve opening direction based on the internal oil pressure and the third line oil pressure Pl. 1L and 3rd line oil pressure P
I! When the thrust in the valve closing direction based on 3 is exceeded, the spool valve element 434 is moved against the urging force of the spring 426, and the gap between the port 422b and the port I-422c is cut off, and the connection between the port 422c and the drain is interrupted. Since it is communicated with the port 422d, the reverse brake 7o is opened to the drain, 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 P8 is
When the shift lever 252 is operated to the R range, the forward/reverse switching device 16 is prevented from establishing the reverse gear. However, the reverse inhibit valve 420 cannot be operated 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 one of these is performed, the spool valve element 434 is moved according to the biasing force of the spring 426, and is brought into communication with the reverse brake 70 or the boat 256 of the manual valve 250. Therefore, the fourth solenoid valve 3 is controlled by the electronic control device 460, which will be described later.
If the shift lever 252 is erroneously operated from the D range to the R range after passing through the N range and the linear valve 390 is in the off state and the linear valve 390 is in the on state, engagement of the reverse brake 70 is prevented. The forward/reverse switching device 16 is maintained in the 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,. , or first
Since it is supplied to the chamber 136 of the second pressure regulating valve 102 through the relay valve 380, the pressure is lowered by a predetermined amount depending on the second line oil pressure PA2 or the signal pressure P8°IL. As a result, in the N range, the clamping force on the transmission belt 44 is made as low as possible within a range that does not cause slippage, and in addition to lowering 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 P, regardless of the operating state of the second relay valve 440, that is, the third solenoid valve 330. 3
．． The second line oil pressure PA 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.

is the signal pressure P6°1. output from the linear valve 390 according to the following equation (4). A predetermined pressure is applied based on This allows the shift lever 25 to be
2, the second line oil pressure P12 is increased when accumulator back pressure is controlled by operating the shift lever 252 from the N range to the D or R range. Therefore, in a state where there is a risk that the transmission belt 44 of the CVT14 may slip as described above, the tension of the transmission belts 1 to 44 (
The clamping force on the transmission belt 44 is increased from time to time to increase the torque transmission capacity.

PI! 2 = [A<-Pth+(A4'
-A4)P,,z,+WAt・P,) /(A, -A,
)...(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 selectively drives the first solenoid valve 266, the second solenoid valve 268, the third solenoid valve 330, the fourth solenoid valve 346, and the linear valve 390 in the hydraulic control circuit. As a result, the gear ratio γ of the CVT l4, the engaged state of the lock-up clutch 36 of the fluid coupling 12, and the second
Controls the rise or fall of line oil pressure P12.

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 CVTl 4, respectively, and a throttle valve opening that detects the opening of the throttle valve provided in the intake pipe of the engine 10. sensor 468, operation position sensor 470 for detecting the operation position of shift lever 252, brake switch 472 for detecting operation of the brake pedal, engine 10
rotational speed N. Engine rotation sensor 4 for detecting
74, oil temperature sensor 475 for detecting the temperature of hydraulic oil, second
A signal representing vehicle speed SPD, input shaft rotational speed N1. , a signal representing the output shaft rotational speed N0,1, a signal representing the throttle valve opening θ, h, a signal representing the operation position P8 of the shift lever 252, a signal representing the brake operation, a signal representing the engine rotational speed N6. Signal, hydraulic oil temperature T. Signal representing 11, oil pressure sensor 476
Signals representing output pressures p, , <second line oil pressure Pj'z) of CP in electronic control unit 460
U processes the input signal according to a program prestored in the ROM while utilizing the temporary storage function of the RAM, and processes the input signal in accordance with the program stored in advance in the ROM, and operates the first solenoid valve 266, the second solenoid valve 268, and the third solenoid valve 330.
, the fourth solenoid valve 346, and a signal for driving the linear valve 390.

In the electronic control unit 460, initial processing is executed when the power is turned on, and then a main routine (not shown) is executed, so that input signals etc. from each sensor are sequentially read, and based on the read signals, The rotation speed N + n of the input shaft 30, the rotation speed N0u of the output shaft 38, the gear ratio γ of the CVT 14, the vehicle speed SPD, etc. are repeatedly calculated, and the lock-up clutch 36 is engaged according to the input signal conditions. Control and sudden release control, CVT 14 shift 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.

FIG. 1 is a functional block diagram showing the configuration of second line oil pressure optimum control by the electronic control device 460. In the figure, the hydraulic control circuit of the CVT 14 is as described above.
The basic oil pressure P is used to apply a clamping force to the transmission belt 44.
m @ e based on the throttle pressure P1h and the gear ratio pressure P, and the second pressure regulating valve 102 that regulates the drive current value 1.
. Output signal pressure P, which continuously changes according to 1L. 1L
is supplied to the second pressure regulating valve 1021, and the second pressure regulating valve 10
In the electronic control device 460, the tension control pressure control means 478 or the basic oil pressure P m *e calculated from the pre-stored relationship is provided. The output signal pressure P8°IL of the linear valve 390 is adjusted according to a predetermined control formula so that the difference between the optimum pressure P02° and the optimum pressure P02° is eliminated. The electronic control unit 460 also controls the actual pressure P6.5 (-Pi) detected by the oil pressure sensor 476.
! 2) and optimum pressure P62. A correction value P for correcting the output signal pressure of the linear valve calculated according to the above control formula so as to eliminate the control deviation from the linear valve. , the above basic pressure Pm. and the optimum pressure P 6 pl,
It also includes a correction value determining means 480 for storing the correction value PG in a correction value map in the RAM of the electronic control unit 460.

Below, the main control operations of the electronic control device 460 will be explained according to the flowchart of FIG. 20. In this control, the second line oil pressure P I 2 is set to the ideal pressure P o
It includes optimal control to match Dl and learning control to determine a correction value P6 to improve pressure regulation accuracy in this optimal control.

In FIG. 20, in step SPI, the transmission belt 4
Optimum pressure of the reservoir that optimally maintains the tension of 4 P 11 D
I or the actual CvT14 from the following formula (5) stored in advance
The input torque T, (=output torque of the engine 1o) and the effective diameter of the -next side variable pulley 4o.

(=the hanging diameter of the transmission belt 44). The input torque T + n is calculated based on the engine rotation speed N and the throttle valve opening degrees θ and h from a pre-stored relationship, and the above-mentioned D1° is calculated based on the actual gear ratio from a pre-stored relationship. Calculated based on γ. In addition,
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.

Further, 01 and C2 in the following equation (5) are constants.

P,,,=C,・T,,/D,,,-C2-N,
,,"10ΔP... (5) In the following step SP2, the corrected value Py.e' of the basic oil pressure P, . ) is calculated based on the throttle pressure P1h and the gear ratio pressure P,'.The above throttle pressure P
1h is the throttle valve opening θ from the pre-stored relationship;
In addition, the gear ratio pressure P7' is calculated based on the effective diameter D In of the next-side variable pulley 40 based on the relationship stored in advance to indicate the oil pressure value corresponding to the gear ratio γ.
or the optimum pressure P in a region where this value P is less than or equal to the optimum pressure P o p +. , 1. In addition, the above gear ratio pressure P
The calculated value of , is limited so as not to exceed the optimum pressure P0,1. In addition, C6, C6, and C7 in the following formula (6)
is a constant.

P,,c'=C5+C@-P,h-Ct-P,'
(6) In the following step SP3, the optimum pressure P0,1 and the basic oil pressure P me e are obtained from the correction value map in the RAM.
After the correction value P6 is read out in response to ', it is determined in step SP4 whether the hydraulic oil temperature T o + 1 is lower than a predetermined judgment reference value CTl.

This judgment reference value Ca1 is used to determine the reliability of the pressure detected by the oil pressure sensor 476.
The detection accuracy of 6 is set to the lower limit of the guaranteed oil temperature range. For this reason, if the judgment in step SP4 is affirmative, the hydraulic oil temperature T o l + is too low to obtain the accuracy of the oil pressure sensor 476, so step S9 is performed without determining the correction value. is executed and the content of the integrated value ■ is cleared to "0", in step 5 PIO corresponding to the tension control pressure control means 478, the second
Line oil pressure Pj72 or optimum pressure P. 2. From the control equation (7) shown below, which is stored in advance so that
Optimal pressure P6-1 and basic oil pressure correction value P calculated using PI and SF3. . . The output signal pressure P8°1L of the linear valve 390 is determined based on the control deviation of step 7 and the like. Note that k is a constant.

P. ,,-〇, ・(Pl,.Pal++)
10 p6 10 -1,...(7) And step 5PII is the above step knob 5PI
Drive current value I for obtaining the output signal pressure P6°1L calculated at O. IL is determined from the relationship shown in FIG. 17 and is output.

Hydraulic oil temperature T. 11 or exceeds the judgment reference value CTl, the judgment in step SP4 is negative, and therefore, in step SP5, whether or not the shift control is in a steady state is determined by, for example, the control deviation (pm, e' - p,... ) is below a predetermined value.

In this step, the correction value P. It is used to judge whether or not the inside of the hydraulic control circuit is in a steady state to the extent that it can be determined. If the judgment of Step SP4 is negative, the situation is inappropriate for determining the correction value, so
Step SP9 and subsequent steps are executed.

However, if the judgment in step SP5 is affirmative, then in step SP6, the oil pressure P l fi f detected by the oil pressure sensor 476 and the optimum pressure P o
It is determined whether the difference from pl (p, , -p, , > is less than a predetermined criterion value ε).

In this step SP6, the oil pressure P t , g and the optimum pressure P are determined. , I is provided to judge whether they almost match, and the above judgment standard value ε is extremely /J\
is set to a low value. If the judgment at step SP6 is negative, the integrated value 1. or the above difference (P, , , -P
, , , ) are updated by adding them, and then steps 5 and below are executed.

While the above steps are repeatedly executed, the third term on the right side of the control equation (7) is increased (=). In knob SP8, the values of the second and third terms on the right side of control equation (7) at this time (=p,
10k −T,) is the optimum pressure P,,1 and the basic oil pressure Po, at that time. ' is stored in the correction value map in place of the previous correction value. Then, steps SP9 and subsequent steps are executed.

As described above, according to this embodiment, the correction value determining means 48
In step SP8 corresponding to 0, the oil pressure sensor 47
Actual pressure P87 detected by 6, and optimum pressure P,
, , the output signal pressure P of the linear valve 390 is calculated according to control equation (7) so that the control deviation between , , and
. The correction value P for correcting 1L is the correction value P of the basic oil pressure. e' and the optimum pressure p op, and its correction value P6 is stored in the correction value map.

Therefore, due to the individual difference of the second pressure regulating valve 102, the basic oil pressure P
,. , 1 changes, the correction value P6 is determined and stored accordingly, so that the second pressure regulating valve 102
This prevents a decrease in control hydraulic pressure regulation accuracy due to individual differences in oil pressure.

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-described embodiment, of the pair of hydraulic cylinders 54 and 56, the first line hydraulic pressure Pf is applied to the driving side hydraulic cylinder, and the second line hydraulic pressure PI! is applied to the driven side hydraulic cylinder. 2 was in effect,
It is also possible to use a hydraulic circuit in which the common line hydraulic pressure Pl is always applied to the second hydraulic cylinder 56.

Furthermore, if the oil pressure sensor 476 has a wide practical temperature range, step SP4 of the above embodiment may be omitted.

It should be noted that 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 diagram showing the main configuration of the embodiment shown in FIG. 2, and is a block diagram illustrating the functions of the electronic control device shown in FIG. FIG. 2 is a schematic diagram showing a belt-type continuously variable transmission for a vehicle 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. FIG. 4 is a diagram showing the second pressure regulating valve of FIG. 3 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. FIG. 9 is a diagram showing ideal characteristics of the second line oil pressure. FIG. 10 is a diagram illustrating the speed change control valve device of FIG. 3 in detail. FIG. 11 is a diagram illustrating the relationship between the operating states of the first solenoid valve and the second solenoid valve in the speed change control valve device of FIG. 3 and the shift state of the CVT shown in FIG. 2. Figures 12, 13, and 14 are for Figure 2 (7) CVT (
7) Diagrams illustrating the relationship between the gear ratio and the oil pressure values of various parts, in which Figure 12 shows the positive torque running state, Figure 13 shows the engine brake running state, and Figure 14 shows the no-load running state. It is. 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. 18th
The figure shows the third solenoid valve and the fourth solenoid valve in the hydraulic circuit of FIG.
FIG. 3 is a diagram showing the correspondence between the combination of operations of electromagnetic valves and the operating state of a lock-up clutch. 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 flowchart illustrating the operation of the electronic control device of FIG. 2. 14: CVT (vehicle belt type continuously variable transmission) 44: Transmission belt 102: Second pressure regulating valve (pressure regulating valve) 390: Linear valve 476: Oil pressure sensor 478: Tension control pressure control means 480: Correction value determining means first Figure 4 Cause Figure 5 Figure 6 Figure 7 Design Datsu ratio r (・1・) Shun 1i Shihi r (・1・) 930 Datsu Hr (throat) Rice 1it-Otsu r (71・) Figure 15 Figure 18

Claims (1)

[Claims] In a vehicle belt-type continuously variable transmission in which power is transmitted via a transmission belt, basic hydraulic pressure is adjusted based on throttle pressure and gear ratio pressure in order to apply a clamping force to the transmission belt. and a linear valve that supplies an output signal pressure that continuously changes according to a control signal value to the pressure regulating valve and shifts the basic hydraulic pressure regulated by the pressure regulating valve, and has a relationship stored in advance. A hydraulic control device of the type that adjusts the output signal pressure of the linear valve according to a predetermined control formula so as to eliminate the difference between the basic oil pressure and the optimum pressure calculated respectively from the pressure regulating valve, the pressure being regulated by the pressure regulating valve. an oil pressure sensor that detects oil pressure; and correcting the output signal pressure of the linear valve calculated according to the control formula so that a control deviation between the actual pressure detected by the oil pressure sensor and the optimum pressure is eliminated. A belt type vehicle for a vehicle, comprising: correction value determining means for determining a correction value corresponding to the basic oil pressure and the optimum pressure, and storing the correction value in a correction value map. Hydraulic control device for gear transmission.