JPH04203668A - Hydraulic controller of belt type continuously variable transmission for vehicle - Google Patents

Abstract

PURPOSE:To secure sufficient driving force immediately after sudden braking operation at time of coasting by making the extent of hydraulic pressure in a secondary side hydraulic cylinder higher than that of a primary side hydraulic cylinder in the case where car speed and judging transmission gear ratio are less than the criterion value at a neutral range. CONSTITUTION:When a shift lever 252 is operated to be positioned in the neutral range, car speed is less than the preset criterion value and transmission ratio also is less than the criterion value, initial pressure in a shift control valve gear 260, namely, first line hydraulic pressure is regulated by an initial pressure control means 480 so as to make the hydraulic pressure acting on a secondary side hydraulic cylinder 56 heighten to a primary side hydraulic cylinder 54. With this constitution, a shift rate is heightened to the most deceleration side of transmission gear ratio, and since the transmission gear ratio is quickly set to the most deceleration side value in advance at time of coasting stoppage, sufficient driving force is secured at time of restarting by operating the shift lever 252 to put in the travel range immediately after sudden braking operation at coasting in the neutral range.

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.

Conventional technology In belt-type continuously variable transmissions for vehicles, the power is transmitted when the shift operating device is operated to the travel range, and the power transmission is cut off when the shift operating device is operated to the neutral range. The connecting/disconnecting means is provided on the output side, while a transmission belt is provided that transmits power by being wound around a pair of variable bobbins with variable active diameters, and the effective diameter of the variable bobbles is provided on the input side. The gear ratio can be changed by changing the hydraulic cylinder and the output side hydraulic cylinder. The hydraulic control device for this belt-type continuously variable transmission normally operates the engine according to predetermined relationships to achieve fuel efficiency and drivability when the vehicle is running, such as the throttle valve opening and vehicle speed. The gear ratio is divided based on. In addition, during coasting, the speed change control valve device is operated so that the input shaft rotational speed changes according to the relationship when the throttle valve opening is at the minimum value among the above relationships. By adjusting the gear ratio of the transmission, the gear ratio is changed to a value on the maximum deceleration side as the vehicle speed decreases. Normally, the relationship used during coasting is such that the power is disconnected in order to alleviate the re-engagement shock that occurs when the shift operating device is operated to the travel range again and the power disconnection means is engaged. It is determined that the rotations of the input-side rotating body and the output-side rotating body of the means are synchronized.

Problems to be Solved by the Invention However, in the above-mentioned conventional hydraulic control system for a belt type continuously variable transmission for a vehicle, when coasting in the neutral range, the engine becomes idling rotation as the power disconnection means is released. As shown in FIG. 23, the gear ratio remains relatively on the speed increasing side until the vehicle speed reaches an extremely low speed. For example, the relationship when the throttle valve opening is 0% in the transmission diagram described in Japanese Patent Application Laid-Open No. 63-116933 is also shown. Therefore, when the shift operation device is operated from the neutral range to the driving range and the power connection/disconnection means is engaged in order to re-accelerate the vehicle immediately after a sudden braking operation, the belt-type continuously variable transmission Since the machine is connected to the drive wheels via the power disconnection means, the gear ratio does not change toward the maximum deceleration value, and the vehicle cannot obtain sufficient driving force when restarting. There was. In other words, when the vehicle is stopped due to a sudden braking operation while coasting in the neutral range, the belt type continuously variable transmission is rotated by the engine via the fluid coupling, and its gear ratio is set to the maximum deceleration side. However, there are cases where the gear ratio is changed to the driving range before reaching the value on the lowest deceleration side.

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 a vehicle that can provide sufficient driving force even when the driving range is operated immediately after a sudden braking operation during coasting in the neutral range. It is in.

Means for Solving the Problems The gist of the present invention for achieving the above object is that when the shift operating device is operated to the travel range, the power transmission state is established, and the shift operating device is set to the neutral range. For vehicles equipped with a power disconnection means on the output side that cuts off power transmission when operated, and in which the effective diameter of the variable pulley around which the transmission belt is wound can be changed by the primary hydraulic cylinder and the secondary hydraulic cylinder. In the belt-type continuously variable transmission, when decelerating, the speed change control valve device is operated to change the gear ratio of the belt-type continuously variable transmission so that the input shaft rotational speed changes according to a predetermined relationship. A hydraulic control device of the type that adjusts the shift operation device, comprising (a) an operation position sensor for detecting the operation position of the shift operation device, (b) a vehicle speed sensor for detecting the speed of the vehicle, and (C) the a gear ratio detection means for detecting a gear ratio of the belt-type continuously variable transmission; If the ratio is less than a predetermined reference value, the source pressure of the speed change control valve device is adjusted so that the hydraulic pressure applied to the secondary hydraulic cylinder is higher than that of the primary hydraulic cylinder. and source pressure control means.

In this way, if the shift operating device is in the neutral range, the vehicle speed is less than half the predetermined criterion value, and the gear ratio is less than the predetermined criterion value, When coasting in the neutral range, the vehicle speed is extremely low and the gear ratio has not yet approached the maximum deceleration value, so the source pressure control means controls whether the hydraulic pressure applied to the secondary hydraulic cylinder or the primary side The source pressure of the transmission control valve device is adjusted to be increased relative to the hydraulic cylinder. In this way, as a result of adjusting the source pressure of the shift control valve device so that the hydraulic pressure applied to the secondary hydraulic cylinder is higher than that of the primary hydraulic cylinder, the shifting speed toward the lowest speed reduction side of the gear ratio is increased. The gear ratio is quickly set to the maximum deceleration value in advance, so that sufficient driving force is available even when restarting by operating into the travel range immediately after a sudden braking operation during coasting in the neutral range. You can get it.

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 the pump impeller 28 connected to the crankshaft 26 of the engine lO, and the input shaft 3 of the CVT l4.
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, the hydraulic oil is supplied to the retaining side oil chamber 33 and at the same time, the 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 becomes less than the predetermined value, or when the engine speed becomes less than the predetermined value, the release side oil chamber 35
By supplying hydraulic oil to the lock-up clutch 36 and draining the hydraulic oil from the engagement side oil chamber 33
is released.

The CVTl 4 has variable pulleys 40 and 42 of the same diameter provided on its input shaft 30 and output shaft 38, respectively;
The transmission belt 44 is 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 N of input shaft 30, , /rotational speed N of output shaft 38. u+). Since the variable pulleys 40 and 42 have the same diameter, the hydraulic cylinders 54 and 56 have similar pressure receiving areas. Typically, the pressure of the driven 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-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 l4) 38 of No. 6 and meshes with the planet gear 62 on the inner circumference side, a ring gear 68 that meshes with the planet gear 64 on the outer circumference 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 neither of them is 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. In addition, the reverse brake 7
When 0 or 0 is engaged, the direction of rotation is reversed between the output shaft 38 of the CVT l4 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 8o is leaked to the return oil passage 78 and the lock-up cludge 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 8o is The first line oil pressure pH in the line oil passage 80 is also regulated. In addition, the first line oil pressure Pl 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.
Line hydraulic PI! The pressure is adjusted to 2 or more. This second line oil pressure P12 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 sea) 112, return spring 11
4. Equipped with plunger II6. 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 in this order.

A chamber 126 is provided between the second land 120 and the third land 122, into which the second line oil pressure P12 is introduced as feedback pressure through the throttle 124, and the spool valve 110 is closed by the second line oil pressure Pz. The valve is biased toward the valve. 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. 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 for applying a throttle pressure P1h, which will be described later, is provided on the end surface 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 element 110 is calculated by the following formula ( 1) is basically balanced at the position where That is, as the spool valve element 110 is moved according to equation (1), the hydraulic oil in the first line oil passage 80 led to the port 134a is transferred to the second line via the port 134b.
The state in which the oil flows into the line oil passage 82 and the state in which the bow 1-13
The state in which the hydraulic oil in the second line oil passage 82 guided to the second line oil passage 82 is flowed to the drain port 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 PR+, which is a relatively high oil pressure, as described above. A hydraulic pressure Pi2 is generated as shown in FIG.

Pz2=(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.
A chamber 136 is provided through which a signal pressure P8.1 is introduced, the spool valve 110 or its signal pressure P,. 1 in the valve closing direction, the second
Line hydraulic PI! 2 is depressurized. Furthermore, the land 117 and the land 11 of the plunger 116 are
9, a control pressure P8° 1
A pressure increasing oil chamber 133 is provided for increasing the second line oil pressure P12 by applying the signal pressure P8°1. The pressure is increased accordingly. 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 port i 50a communicating with the first line oil passage 80 and the drain port 150b or 150c, and the first line as feedback pressure is applied to the end face of the first runt 152. A chamber 153 is provided for applying the hydraulic pressure PA via a throttle 151, and the spool valve element 140 is biased in the valve opening direction by this first line hydraulic pressure P l +. The first plunger 146 is provided coaxially with the spool valve 140.
A chamber 156 for guiding the throttle pressure PIh is provided between the land 154 and the second land 155, and a chamber 156 for guiding the throttle pressure PIh is provided between the second land 155 and the second plunger 148. Hydraulic P. Branch oil path 30
A chamber 157 is provided for introducing the hydraulic pressure through the second plunger 148, and a second line hydraulic pressure P
A chamber I58 is provided for introducing l2. Since 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, the biasing force is applied to the spool valve element 140 in the valve closing direction.
The pressure receiving area of 1 is A5, the cross-sectional area of the first land 154 of the first plunger 146 is A6, the cross-sectional area of the second land 155 and the second plunger 148 is A7, and the return spring 1 is
44 is assumed to be W, the spool valve element 140 is balanced at a position where the following equation (2) is satisfied, and the first line oil pressure Pf is regulated.

Pi , = ((P+, Or Pj22) ・A? 10P+h(A
s A? )+W:l/A5・・・・・(2) In the first pressure regulating valve 100, the primary side hydraulic cylinder 5
4 internal hydraulic pressure p la is the 2nd line hydraulic pressure PA2 (in steady state, PI!2 = secondary side hydraulic cylinder 56 internal hydraulic pressure P6u,)
If the pressure is higher than that, the first plunger 146 and the second plunger 148 are spaced apart and the thrust by the hydraulic pressure P In in the primary hydraulic cylinder 54 acts in the valve closing direction of the spool valve element 140, or the primary If the hydraulic pressure P0 in the side hydraulic cylinder 54 is lower than the second line hydraulic pressure P12, the first
Since the plunger 146 and the second plunger 148 are in contact with each other, the thrust due to the second line oil pressure P 72 acting on the end face of the second plunger 148 acts on the spool valve element 140 in the valve closing direction. That is, the second plunger 148, which receives the oil pressures P and n in the primary side hydraulic cylinder 54 and the second line oil pressure P12, applies an acting force based on the higher of these oil pressures in the direction of closing the spool valve element 140. Let it work. Note that a chamber 160 provided between the first land 152 and the second land 159 of the spool valve 140 is open to a 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. 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 and plunger 18 applied via spring 188
By being positioned at a position where the thrust from 6 and the thrust due to the first line oil pressure pH are balanced, the first line oil pressure P
A spool valve element 190 that reduces the pressure of f and generates a throttle pressure Plh corresponding to the actual throttle valve opening θ1h.
It is equipped with FIG. 6 shows the throttle pressure P1h and the actual throttle valve opening θ7. The throttle pressure P lh is supplied through the oil passage 84 to the first pressure regulating valve 100, the second pressure regulating valve 102, the third pressure regulating valve 220, 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 end movable rotating body 50 of the CVT l4 and is moved in the axial direction by a displacement amount equal to the displacement I in the axial direction, and A spring 194 correspondingly transmits a biasing force, and while receiving the biasing force from this spring 194, receiving the second line oil pressure Pβ2 and being positioned at a position where the thrusts of both are balanced, the discharge flow rate to the drain is reduced. 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 way 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
r is the second line oil pressure PI! On the other hand, the second pressure regulating valve 102, which operates according to equation (1), reduces the second line oil pressure P12 as the gear ratio pressure Pr increases. Therefore, when the gear ratio pressure Pr increases to a predetermined value and becomes equal to the second line oil pressure P72, both are saturated and become constant thereafter.

FIG. 8 shows the basic output pressure (maximum value of the second line oil pressure PI!2) P 11+4 which is regulated in the second pressure regulating valve 102 according to the above formula (1) in relation to the above-mentioned gear ratio pressure Pr.
It shows the output characteristics of c. In other words, the optimum control pressure, ie, the ideal pressure P, for setting the tension of the transmission belt 44 shown in FIG. 9, which is required for the low-pressure side line oil pressure in relation to the gear ratio γ, to an optimum value. Characteristics relatively similar to the curve 21 can be obtained only by the valve mechanism. Basic oil pressure P in FIG. 8 obtained by the valve mechanism of the second pressure regulating valve 102
m @ e is the spool valve 110 of the second pressure regulating valve 102
It is a mechanically determined value related to the pressure receiving area of the plunger 116, etc., and is an ideal pressure P so that sufficient clamping force can be obtained even during sudden speed changes. It is set higher than pl.
``The third pressure regulating valve 220 generates an optimum third line oil pressure PA'2 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, into which the third line oil pressure Pi3 is introduced as feedback pressure through the throttle 234. It is biased in the valve closing direction by hydraulic pressure P73. Further, a chamber 240 to which the gear ratio pressure Pr is guided is provided on the first land 230 side of the spool valve 222.
2 is biased in the valve closing direction by the gear ratio pressure Pr. In the third pressure regulating valve 220, the biasing force in the valve opening direction of the return spring 226 or the spring seat 22
4 to the spool valve element 222. Further, a chamber 242 for applying throttle pressure PIh 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 PIh. Further, a chamber 248 is provided between the first land 244 of the plunger 228 and the second land 246 having a smaller diameter than the first land 244 for guiding the third line hydraulic pressure P13 only during reverse movement. For this reason, the third line oil pressure Pf3 is calculated from a formula similar to the formula (1) above.
The pressure is adjusted to an optimal value based on r and throttle pressure P1h. This optimal value is the forward clutch 7
2 or a necessary and sufficient value to ensure that torque can be transmitted without slippage at the reverse brake 70. Also, when moving backward, the third line hydraulic pressure PI! 3, the force that urges the spool valve element 222 in the valve opening direction is increased, and the third line oil pressure P13 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.

The third line hydraulic pressure P13 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. In the state where it is being operated to, the third line oil pressure Pf! , is exclusively output from the output port 258 and supplied to the forward clutch 72, and at the same time allows oil to be drained 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 P A s is output to the output port 2.
56 to port 422 of reverse inhibit valve 420
a and 422b, and further supplies oil to the reverse brake 70 through the reverse inhibit valve 420, while allowing oil to drain from the forward clutch 72, and is operated to N (neutral) and P (parking) ranges. In this state, oil is allowed to drain from both the forward clutch 72 and the reverse brake 70. 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 Pl 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 in order to adjust the gear ratio γ of the CVTl 4. 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 hydraulic pressure PI! for driving the speed change direction switching valve 262 and the flow rate control valve 264! a is the first line oil pressure PI! by the fourth pressure regulating valve 170. , 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 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 where 1 is introduced
77 is provided, and the non-spring 1 of the spool valve 171
The end face on the 72 side is open to the atmosphere. In the fourth pressure regulating valve 170 configured in this way, the spool valve 171 or
A biasing force in the valve-closing direction based on the feedback pressure corresponding to the fourth line oil pressure PA4, a biasing force in the valve-opening direction by the spring 172, and the signal pressure P. As a result of being operated so that the biasing force in the valve opening direction based on L is balanced, the fourth
Line hydraulic PR.

is regulated to a value corresponding to the magnitude of the signal pressure P golL, which will be described later.

As shown in detail in FIG. 10, the speed change direction switching valve 262 is a spool valve controlled by the first solenoid valve 266, and has a drain port 1278a communicating with the drain and a first
Ports h278b, 278d, and 278f communicate with the connecting oil passage 270, the second connecting oil passage 272 with the first throttle 271, and the third connecting oil passage 274, and the first
A port 278c to which the line hydraulic pressure Pl is supplied through the throttle 276, a port 278e to which the first line hydraulic pressure Pjl' is supplied, a port 278g to which the second line hydraulic pressure P12 is supplied, and one end of the movement stroke (Fig. top edge)
a spool valve element 280 that is slidably disposed between a deceleration side position (on side position), which is the speed reduction side position (on side position), and a speed increase side position (off side position), which is the other end of the movement stroke (lower end in the figure);
A spring 282 is provided to bias the spool valve element 280 toward the speed increasing side position. The spool valve element 280, which functions as a speed change direction switching valve element, is provided with four lands 279a, 279b, 279c, and 279d. Spring 282 of the spool valve 280
The side end faces are 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. 4 is applied, but when the first solenoid valve 266 is in the off state, that is, in the open state, the pressure on the downstream side of the throttle 284 is exhausted and the fourth
The line oil pressure PI2< is not 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 also in the position shown on the ON side in the figure, and the first
When the electromagnetic valve 266 is in the OFF position shown in the figure, the shift direction switching valve 262 is also in the OFF position shown in the figure. Therefore, during the period when the first solenoid valve 266 is in the ON state, the spool valve 280 is positioned at the deceleration side position, and the drain port 278a and the port 278b and the port 278e and the port 278f are opened. and port 2 between ports 278b and 2780.
between 78d and 278e, and po) 278f and 27
8g or closed respectively, the first solenoid valve 266
During the period in which the spool valve 280 is in the OFF state, the spool valve 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 1L through an oil passage 285 and generates thrust in a direction toward the deceleration side position of the spool valve 280. This signal pressure P.

1 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 primary hydraulic cylinder 54 via the primary oil passage 300 and is connected to the primary hydraulic cylinder 54 via the primary 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 divider 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 spool valve element 288 on the spring 290 side 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 oil pressure P14 is applied, and in the off state, that is, the open state, the downstream side of the throttle 292 is exhausted and the fourth line oil pressure PA4 is not applied. When the second solenoid valve 268 is in the state shown on the ON side in the figure, the flow 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 control valve 264 is in the operating position shown on the ON side in the figure. 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-restriction side position and the valve is closed between the port 286a and the bow 1-286b. , during the period when ports 286c and 286d are opened or when the second solenoid valve 268 is in the off state (duty ratio is 0%), the spool valve 2
88 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 supplies the first line hydraulic pressure P! , or when supplied, the 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. . , (=Pβ1) from the secondary hydraulic cylinder 56 from the second line hydraulic pressure P A 2 during gradual deceleration shifting.
This is to ensure that hydraulic oil is supplied to the inside.

Further, the throttle 296 and the check valve 298 suitably alleviate pulsations occurring in the hydraulic pressure p out in the secondary hydraulic cylinder in synchronization with the duty drive of the flow control valve 264 . That is, in the pulsation of the hydraulic pressure P0.1 in the secondary hydraulic cylinder, the spike-like upper peak is released by the throttle 296, and the lower peak of P Oul is compensated for through the check valve 298. In addition, check valve 298
The valve seat 299 has a planar seat surface, the valve element 301 has a planar contact surface that comes into contact with the seat surface, and a spring that urges the valve element 301 toward the valve seat 299. 30
3, and is designed to open with a pressure difference of about 0.2 kg/Cm''.

In addition, in the primary side oil passage 300, the second connection oil passage 272
A second throttle 273 is provided between the confluence point of the branch oil passage 305 and the branch point of the branch oil passage 305 . Here, the throttle 273 determines the speed at the time of sudden deceleration and shifting, and is set so that the maximum speed is achieved within a range where only slipping 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 deceleration.

Therefore, when the first solenoid valve 266 is on,
Regardless of the operating state of the second electromagnetic valve 268, the gear ratio γ of the CVTI 4 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 8o flows through the ports 278e and 27.
8f, third connection oil passage 274, bow) 286d, bow) 2
86c.

The hydraulic oil in the primary hydraulic cylinder 54 flows into the secondary hydraulic cylinder 56 through the secondary oil passage 302, while the hydraulic oil in the primary hydraulic cylinder 54 flows through the primary oil passage 300, port 286a,
b, first connection oil passage 270, port 278b, drain port) 278a and is discharged to the drain. This results in
As shown in FIG. 11(a), the gear ratio γ is rapidly changed in the direction of deceleration.

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 primary hydraulic cylinder 54 is supplied to the secondary hydraulic cylinder 56 through the check valve 298, and the hydraulic oil in the primary hydraulic cylinder 54 is supplied through a small gap formed actively or inevitably around 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 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 γ 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 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 is supplied to the throttle 276 and ports 1 to 2.
78 c.

Port 278b, first connection oil passage 270, port 286b
, port 286a, and into the primary hydraulic cylinder 54 through the primary oil passage 300.
78e, port) 278d, the second connection oil passage 272, and the primary oil passage 300 into the primary hydraulic cylinder 54, while the hydraulic oil in the secondary hydraulic cylinder 56 flows through the secondary oil passage 302, the port 286c, port 286d,
Third connection oil passage 274, port 278f, port 278g
It is discharged to the second line oil passage 82 through. 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 connecting oil passage 270 or the flow rate control valve 264 closes 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 pH at CVTl,4 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 value like that 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 primary hydraulic cylinder 54 and the secondary hydraulic cylinder 56 are equal, during normal drive running as shown in FIG.
Hydraulic pressure P in 6. u+ % Po during engine braking driving as shown in Fig. 13. +>Pl++, 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 is to generate the thrust of the hydraulic cylinder on the driving side, it is necessary to reduce the power loss so that the hydraulic cylinder can generate the thrust to obtain the target gear ratio γ. In order to reduce this, it is desirable that the first line oil pressure P l + be regulated to a value obtained by adding a necessary and sufficient margin oil pressure α to the above P In.

However, the first line oil pressure P7 shown in FIGS. 12 and 13 above. Therefore, in this embodiment, the first pressure regulating valve 100 is provided with a second plunger 148 to adjust Plfi and the second line hydraulic pressure P1. The biasing force based on the higher oil pressure is transmitted to the spool valve 140 of the first pressure regulating valve 100. As a result, as shown in FIG. 14, for example, a curve indicating P l++ and P, .

During no-load running, where the curve intersects with the first
Line oil pressure pH is Pl. and second line oil pressure P'12
The oil pressure value is controlled to a value obtained by adding a margin value α to the higher oil pressure value. 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 Pz,' shown by the broken line in FIG. 14 is the one when the second plunger 148 is not provided, and in a range where the gear ratio γ is small, an unnecessarily large margin oil pressure is generated. There is.

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 CVT 14 to obtain the desired gear ratio γ, and is clear from equation (2). As such, the first line oil pressure Pj17. in relation to the throttle pressure Plh. is enhanced. 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 In or P
o. 7 and the throttle pressure PIh, or it is saturated at the maximum value corresponding to the throttle pressure PIh. As a result, even if the oil pressure P1° in the primary hydraulic cylinder 54 increases when the gear ratio γ is at its minimum value and the V-groove width of the primary variable pulley 40 is mechanically prevented from decreasing, the Also, the first line oil pressure PA, 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 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 cl. That is, the lock-up clutch pressure regulating valve 310 receives the lock-up clutch hydraulic pressure Pc1 as feedback pressure and urges the spool valve element 312 in the valve opening direction, and the spool valve element 312 urges the spool valve element 312 in the valve closing direction. It includes a spring 314, a chamber 316 to which throttle pressure P1h 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. By operating so that the thrust based on the pressure and the thrust of the spring 314 are balanced and causing the hydraulic oil in the lock-up clutch pressure oil passage 92 to flow out, the lock-up clutch oil pressure pcl increases in accordance with the throttle pressure Plh. to occur.

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 flown 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 solenoid 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 as the fourth line oil pressure P14 of the fourth line oil passage 370 in its ON state. Generate 13. Fourth solenoid valve 346
In its OFF state, the pressure downstream of the throttle 344 is exhausted to the drain, and in its ON state, the fourth line hydraulic pressure P
Signal pressure P, which is the same pressure as A4. Generate I4. The linear valve 390 has a pressure reducing valve type valve mechanism, and the first
As shown in detail in FIG. 6, the output signal pressure P is adjusted by using the fourth line oil pressure P14 as the source pressure. cylinder bore 398 of valve body 397 to generate 1°.
a spool valve 391 slidably fitted therein;
Drive current (control signal value) supplied from the electronic control device 460; 1. Linear solenoid 3 energized by
92, and a core 393 that biases the spool valve 391 toward the pressure increasing side in relation to the excited state of the linear solenoid 392.
, a spring 394 that biases the spool valve element 391 toward the pressure decreasing side, and the output signal pressure P that biases the spool valve element 391 toward the pressure decreasing side. It is equipped with a feedback oil chamber 395 into which 1L is introduced. The Subur 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. According to the output characteristics shown in FIG.
Change 6°1L. The signal pressure P is thus regulated using the fourth line oil pressure P14 as the source pressure. 1 is from the output port 396 of the linear valve 390 to the first relay valve 380
is supplied to port 382b of.

In this embodiment, each of the above signal pressures P8°13,P,. ,4,
P. By combining 1, multiple types of control can be executed, such as lock-up clutch engagement and sudden release control, accumulator back pressure control, N range line oil pressure down control, line oil pressure down control at high vehicle speeds, and reverse inhibit control, which will be described later. It is supposed to be done. Further, the signal pressure P to +L is applied to the shift direction switching valve 2 when the solenoid of the first solenoid valve 266 and the second solenoid valve 268 fails.
62 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. This lock-up clutch control valve 320 controls the hydraulic oil in the oil passage 92 whose pressure is regulated to lock-up clutch oil pressure Pe1.
Engagement side oil passage 322 and release side oil passage 32 of fluid coupling 12
The lock-up clutch 36 is selectively supplied to the lock-up clutch 3 to engage or disengage the lock-up clutch 36, and the lock-up clutch quick release valve 400
By draining the hydraulic oil that flows out when the lock-up clutch 6 is released without passing through the oil cooler 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), the lock-up clutch control valve 320 is connected to a port 321C to which lock-up clutch hydraulic pressure pcl is supplied. 321
cl, port 321b and drain port 321a, port 321e and port 321f, and when releasing the lock-up clutch 36 (off side in the figure), port 3
21c and port 32lb, port 321d and port 32Ie, port 321f and drain port 321g, and a spring 328 that biases spool valve 326 toward the release side (off side). . On the lower end surface side of the spool valve element 326 (non-spring 328 side), there is a signal pressure P8.8. generated when the third solenoid valve 330 is in the on state. or introduced chamber 332
is installed.

The lock-up clutch quick release valve 400 is a spool valve of a two-position operating type, and includes a hoard 4°2a that communicates with the clutch pressure oil passage 92 via a throttle 401, and a release side oil passage 32.
4, and a port 402c that communicates with the port 321b of the lock-up clutch control valve 320.
, port 321f of lock-up clutch control valve 320
port 402e that communicates with the engagement side oil passage 322, lock-up clutch control valve 320
A port 402f communicates with the port 321d of the port 402f, and the port 402c communicates with the port 402b during normal operation (off side in the figure).
, bow) 402e and port 402f, and at the time of sudden release (on side in the figure), the port 402a and port 402
b, a spool valve element 406 that communicates the ports 402d and 402e, and a spring 408 that biases the spool valve element 406 toward the quick release side position. The chamber 410 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. , 4 is designed to be guided. 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 on side shown in the figure, and the lock-up clutch 36 is engaged. Since a third oil passage is formed to allow the hydraulic oil in the lock-up clutch pressure oil passage 92 to flow through the port 321c, port 321d, port 402f, port 402e, and engagement side oil passage 322, the hydraulic oil is transferred to the fluid coupling. 1
2 and flows out from the fluid coupling 12 is drained from the port 321a through the release side oil passage 324, the port 402b, the port 402C, and the port 321b.

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 removed from ports 321C, 321b, and 402c. , Poe) 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, port 1□ 402e, port 402f,
It is drained through port 1-321d, port 402e, and oil cooler 339. 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 port 402a, the port 402b, and the release side oil passage 324, and the hydraulic oil flowing out from the fluid coupling 12 is supplied to the engagement side oil Road 322
, port 402e, port 402d, port 321f,
The oil is drained through the port 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
If the lock-up clutch 36 is stuck in the on side and 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 preferably prevented.

When the lock-up clutch 36 is released as described above, if 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. 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,
Port 402e, port 402d.

It is drained from port 321g via port 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 cooler oil pressure control valve 338 provided upstream 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-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. a port 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;
, 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
When the signal pressure P5°14 is not applied to the spool valve 384, the spool valve 384 is set to the OFF position, and the signal pressure P8°1L is supplied to the chamber 136 of the second pressure regulating valve 102 and the chamber 435 of the reverse inhibit valve 420. ka, room 388
signal pressure P,. , 4 is applied, the spool valve 384 is set to the on side and the signal pressure P is applied. 1L is supplied to the port 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 346.

The second relay valve 440 has ports 442b and 442c that communicate with the chamber 133 of the second pressure regulating valve 102 via a throttle 443 and always communicate with each other, and a port 442d that communicates with the fourth pressure regulating valve 170.

The drain port) 442e is connected to the drain port 442e, and the drain port 442d is connected to the drain port 442e in the on side state shown in the figure, and the drain port 442d is connected to the drain port 442d in the off side state shown
2e, and a spring 446 that biases the spool valve 444 toward the off-side state. When the pressure P8.13 is not applied, the spool valve 444 is in the OFF position, and the signal pressure P is applied to the chamber 448. 13, the spool valve 444 is in the on-side position.

As a result, the signal pressure P being supplied to the chamber 133 of the second pressure regulating valve 102 through the ports 442c and 442b,
. 1L is branched and also supplied to the chamber 177 of the fourth pressure regulating valve 170 when the spool valve element 444 is switched from the on to off position. In the figure, the second relay valve 4
The on and off states shown at 40 are the third
This corresponds to the on and off states of the solenoid valve 330.

Next, accumulators 342 and 340 provided in the forward clutch 72 and the reverse brake 70, respectively.
Explain the back pressure control. The signal pressure P8°1L output by driving the linear valve 390 is changed in accordance with its driving current 1101L as shown in FIG. 17, and the first relay valve 380 is in the ON state for back pressure control. When this occurs 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 shock (holding shock) at the time of N-D shift or N-+R shift, and suppresses the increase in the hydraulic pressure in the hydraulic cylinder for a predetermined period of time when the clutch is engaged, thereby alleviating the shock.

Therefore, the fourth line oil pressure Pff4 supplied to the back pressure boat 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.

The fourth pressure regulating valve 170 is regulated to a pressure corresponding to the fourth line oil pressure P14 or the signal pressure P6°1L.

That is, while the signal pressure P6° 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 Hydraulic pressure P l < is linear valve 3
90 drive currents 1. . Since it is controlled to a value corresponding to 1L, the linear valve 390 is driven to generate a back pressure suitable for reducing shift shock (locking shock). Also, the hydraulic pressure in the forward clutch 72 or the third line hydraulic pressure PI! 3, the fourth pressure regulating valve 17
0 signal pressure P8°1. is the second relay valve 4
40 and opened to the inside of the chamber 177 or to the atmosphere, the fourth line oil pressure Pβ4 is relatively low at 4 kg/cm 2 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 PA4, which has been regulated to a constant pressure, is exclusively applied to the shift direction switching valve 2.
62 and the flow control valve 264 as driving oil pressure (pilot oil pressure). Therefore, this embodiment functions as a valve drive oil pressure generating device that generates valve drive oil pressure for driving the fourth pressure regulating valve 170, the speed change direction switching valve 262, and the flow rate control valve 264.

Next, the second line oil pressure P12 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,
is in the off state □ and the linear valve 390 is in the on state, the output shaft 38 of the CVT 14 is mainly on the secondary side during high-speed rotation, regardless of the operating state of the third solenoid valve 330 and the second relay valve 440. The second line oil pressure P12 supplied to the hydraulic cylinder 56 is reduced. That is,
Signal pressure P = through ports 382b and 382c of first relay valve 380. When IL ("P f 4) is supplied to the chamber 136 of the second pressure regulating valve 102, 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 influence of centrifugal oil pressure in the secondary hydraulic cylinder 56 is eliminated, and the durability of the transmission belt 44 is increased.

Such a reduction control of the second line oil pressure Pi2 is also performed 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.

PI! □=[A4・Plh+W −A,・P, −(A2−A,)・P8゜,L) /(A
3-A2)...(3) The reverse inhibit valve 420, which is provided to prohibit reverse during forward travel, outputs the third line hydraulic pressure P13 from its output port 256 when the manual valve 250 is in the N range. The ports 422a and 422b that are supplied, the port) 422c that communicates with the hydraulic cylinder of the reverse brake 70 via the oil passage 423, and the drain port) 422d, and the first port 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 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 P6° 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 is now possible to do so. A chamber 436 located between the first land 430 and the second land 432 of the spool valve 424 in the first position, and the second land 432 of the spool valve 424 also in the first position.
In the chamber 437 located between the third land 434 and the
The third line hydraulic pressure Pf is applied from the manual valve 250 only when the range is operated, while the reverse brake 70 is applied to the chamber 438 between the spool valve 424 and the plunger 428. The third line hydraulic pressure PI! is applied to the chamber 439 provided on the end face of the plunger 428. 3 is always supplied. Note that the third line oil pressure P of this plunger 428
The pressure-receiving area on which the valve 13 acts is defined as the pressure-receiving area difference between the first land 430 and the second land 432 of the spool valve element 424, which receive the hydraulic pressure in the chamber 436, and the gap between them.

The reverse inhibit valve 42 configured in this way
0 is the biasing force of the spring 426, the reverse brake 70
Based on the oil pressure inside and the third line oil pressure P13 (signal pressure P, than the thrust in the valve opening direction.
I! When the thrust in the valve closing direction based on 3 is exceeded, the spool valve element 434 is moved against the biasing force of the spring 426, and the port 422b and port 422c are cut off, and the port 422C and the drain port 422d are closed. Since the reverse brake 70 is opened to the drain, the reverse gear of the forward/reverse switching device I6 is prevented from being established. 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 is
,. When 1L is generated, shift lever 252 or 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 reverse inhibit valve 420 is activated 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 occurs, 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 port 256 of the manual valve 250. Therefore, if the shift lever 252 is erroneously activated from the D range to 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 (described later). When the reverse brake 70 is prevented from engaging, the forward/reverse switching device I
6 or 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,. 1L passes through the first relay valve 380 to the chamber 136 of the second pressure regulating valve 102
, so the second line oil pressure P12 or the signal pressure P,
. The predetermined pressure is reduced according to 1L. This results in N
In the range, the clamping force on the transmission belt 44 is made as low as possible without causing slippage, which not only reduces the noise level of the belt but also increases the durability of the transmission belt 44.

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. 1
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 P A 2 is output from the linear valve 390 according to the following equation (4). signal pressure P, , the prescribed labor will be increased based on. 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 times, the second line oil pressure P12 is increased. Therefore, the transmission belt 4 of CVTI4 as described above
In a state where there is a risk that slippage may occur, the tension of the transmission belt 44 (squeezing force on the transmission belt 44) is temporarily increased to increase the torque transmission capacity.

PI! 2- (A4・P +h+(A4'-
A4) P. 1. 10W-At・pa/(A3-A2)...(4) FIG. 19 shows the above-mentioned third solenoid valve 330 and fourth solenoid valve 34.
6. 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 3301, the fourth solenoid valve 346, and the linear valve 390 in the hydraulic control circuit. Accordingly, the gear ratio γ of the CVT l4, the engagement 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 rotational speeds of the input shaft 30 and output shaft 38 of the CVTl 4, respectively, and a throttle valve that detects the opening degree of the throat valve provided in the intake pipe of the engine 10. Opening 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 to detect
74, a signal representing the vehicle speed SPD, input shaft rotation speed N1
Signal representing ff1, signal representing output shaft rotational speed N0.1, signal representing throttle valve opening θ1h, shift lever 2
A signal representing the operation position P8 of 52, a signal representing the brake operation, and a signal representing the engine rotational speed N are supplied, respectively. The CPU in the electronic control unit 460 uses the temporary storage function of the RAM and processes input signals according to a program stored in the ROM in advance, and processes the first solenoid valve 266, the second solenoid valve 268, the third solenoid valve 330, Fourth solenoid valve 346
, outputs 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 to sequentially read input signals from each sensor. The rotational speed Nln of the input shaft 30, the rotational speed N of the output shaft 38, . Coupling control and sudden release control, CVTl 4 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 main configuration of second line oil pressure increase control by the electronic control device 460.

In the figure, a power connection/disconnection means 478 corresponding to the forward clutch 72 is provided on the output side of the CVTl 4. The source pressure control means 480 is configured such that the operating position of the shift lever 252 detected by the operating position sensor 470 is in the neutral range, and the vehicle speed SPD detected by the vehicle speed sensor 462 is below a predetermined judgment reference value,
Moreover, the gear ratio γ detected by the gear ratio detection means 482
is less than a predetermined judgment reference value, the shift control valve device increases the hydraulic pressure P out applied to the secondary hydraulic cylinder 56 relative to the hydraulic pressure Plo applied to the primary hydraulic cylinder 54. 260 source pressure, that is, the second line oil pressure Pn2 and the first line oil pressure P1
2 +. Note that the gear ratio detection means 482 corresponds to the input shaft rotation sensor 464 and the output shaft rotation sensor 466.

Below, the main control operations of the electronic control device 460 will be explained according to the flowcharts of FIGS. 20 and 21. This FIG. 20 shows the speed change control routine, and the 21st
The figure shows a hydraulic control routine corresponding to the source pressure control means 480.

In FIG. 20, in step SSI, the shift lever
252 is being operated to the neutral range based on the signal from the operation position sensor 470. If the determination in step SSI is negative, shift control in the drive range, second range, low range, or reverse range is performed in step SS2. For example, JP-A-58-184347
As described in Japanese Patent Laid-Open No. 60-278533, relationships stored in advance for each range in order to obtain fuel efficiency and drivability, such as vehicle speed SPD using throttle valve opening θ1h as a parameter. Based on the relationship between the actual input shaft rotation speed Nl++° and the actual throttle valve opening θ1h and the vehicle speed SPD, the target input shaft rotation speed N3,° is determined, and the actual input shaft rotation speed N1.
The gear ratio γ is adjusted so that , coincides with the target input shaft rotational speed N i no . In this feedback control of the gear ratio γ, the control deviation ΔN, , (=N, ,'-N,
, ), the shift mode shown in FIG. 11 is selected.

If it is determined in step SSI that the vehicle is being operated in the neutral range, in step SS3, the vehicle speed SPD or a predetermined judgment reference value 5PDo is determined.
It is determined whether or not it is less than or equal to N. This judgment standard value 5
PDoN is a vehicle speed within a range where the shock caused by the vehicle's engine braking is not a problem, for example, 10kph.
The value is approximately m/h. If the determination in step SS3 is affirmative, the vehicle is in a low speed state, so the drive duty ratio of the second electromagnetic valve 268 that drives the flow rate control valve 264 is set to 100% in step SS4, and the shift direction is set in step SS5. When the switching valve 262 is brought into the deceleration shift state (the first electromagnetic valve 266 is in the ON state), the rapid deceleration shift mode shown in FIG. 11A is set. As a result, the gear ratio γ is quickly changed toward the value on the maximum deceleration side.

However, if the determination in step SS3 is negative, the vehicle is in a high speed state, so in step SS6, C
The rotation speed N 6 u of the output shaft of the VTl 4, or the rotation speed N of the output shaft 58 of the forward/reverse switching device 16. Whether it is 5 or more, in other words N. . The rotational speed N p cs of the output shaft 58 of this forward/reverse switching device 16 is
It is calculated from the signal from vehicle speed sensor 462 and the reduction ratio of intermediate gear device 18 and differential gear device 20. If the judgment in step SS6 is negative, step SS
In Step 7, the drive duty ratio DUTY of the second electromagnetic valve 268 is calculated from the following equation (5), and in Step SS8, the speed change direction switching valve 262 is brought into an increasing speed change (upshift) state, so that the output shaft of the CVTl 4 is Rotational speed N
0°1 is enhanced. On the other hand, if the judgment in step SS6 is affirmative, the following equation (
6) to drive duty ratio DUTY of the second solenoid valve 268
is calculated, and in step ss5, the shift direction switching valve 2
62, the output shaft rotational speed No. of the CVTl4 is set to a deceleration shift (downshift) state. 1 or lower. As a result, during coasting in the N range, the gear ratio γ is controlled so that the rotations of the input side and output side of the forward clutch 72 are synchronized in order to suppress the shock when the forward clutch 72 is engaged. Ru.

DUTY=to, (NPcs-N, u, )
---(5) DUTY = -(N, , -N,, s)
(6) In the hydraulic control routine shown in FIG. 21, it is determined in step SP1 whether or not the engine is operated in the neutral range. If the determination in step SPI is negative, line hydraulic pressure control is performed in the drive range, second range, low range, or reverse range in step SP2. For example, first, the optimum control pressure P6D as the belt tension control pressure
l is the input torque T of the CVT l4, (=output torque of the engine 10) and the effective diameter of the primary variable pulley 40, (=transmission belt 44) from the following equation (7) stored in advance.
It is determined according to the hanging diameter). Above input torque Tln
is calculated based on the engine rotational speed N6 and the throttle valve opening θ1h from a pre-stored relationship, and
The above D+n is calculated based on the actual gear ratio γ from a pre-stored relationship. Note that the second right-hand side of the following equation (7)
The term is a correction term for centrifugal oil pressure, and the third term on the right side is a margin value. Further, cl and C2 in the following equation (7) are constants.

P,,, =C,-T,, /D,,-C2・Nou,
2+ΔP... (7) Next, the basic oil pressure p regulated by the second pressure regulating valve 1θ2
,,,c! is calculated based on the throttle pressure P1h and the gear ratio pressure P from the following equation (8) stored in advance.

This gear ratio pressure P is calculated based on the effective diameter D in of the primary variable pulley 40 from a pre-stored relationship, and the throttle pressure P1h is calculated based on the throttle valve opening from a pre-stored relationship. Calculated based on θ1h. Note that the calculated value of the gear ratio pressure P is the optimum pressure P.

It is restricted not to exceed 2. Also, the following formula (8
) C5, C6, and C7 are constants.

P,, e'=C5+C6-P, h-C7-P.

(8) Then, from the control formula (9) stored in advance so that the second line oil pressure P12 becomes the optimal pressure P apt, the optimal pressure P calculated by formulas (7) and (8) . The output signal pressure P of the linear valve 390 is based on the control deviation of DI and basic oil pressure Pec'. 1. It is determined and output. Note that C8 is a constant.

P. ,,=Cs・(P,,c'-P,
,, )...(9) However, if it is determined in step SPI that the operation is in the neutral range, step S
At P3, it is determined whether the vehicle speed SPD is less than or equal to a predetermined reference value 5PDoN2. This determination reference value 5PDcN2 is used to determine whether or not the vehicle is in a stopped state, and is, for example, a value of about 2 to 3 km/h.

Even if the vehicle is coasting in the neutral range, if the vehicle is not in a stopped state, the determination in step SP3 is negative, so in step SP4, for example, the fourth solenoid valve 346 is activated as shown in F mode in FIG. If the output signal pressure P8°1L of the linear valve 390 is set to rOJ in step SP5, the second line oil pressure P! is turned on and the second line oil pressure up mode is selected. ! 2 is the basic pressure P of the second pressure regulating valve 102
is made equal to m e c. As a result, in synchronous control, the gear ratio γ is changed to the maximum deceleration value γ0. Ahe is definitely able to change.

When the vehicle comes to a standstill while coasting in the neutral range, the determination in step SP3 is affirmative, so in step SP6 it is determined whether the actual gear ratio γ is less than or equal to a predetermined determination reference value γc1. Ru. This judgment reference value γ. .

is for determining whether the gear ratio γ has substantially reached the maximum speed reduction side, and is the maximum gear ratio γ. , 8. If the determination in step SP6 is negative, the gear ratio γ has almost reached the maximum deceleration side, so in step SP7, for example, mode B shown in FIG. 19 is selected, and in step SP8 The output signal pressure P of the linear valve 390 at .

1. is set to the maximum value (on state), and the noise generated by the transmission belt 44 is made as small as possible.

However, if the judgment in step SP6 is affirmative, the gear ratio γ has not yet substantially reached the maximum deceleration side even though the vehicle is stopped. When the oil pressure up mode is selected, in step 5 PIO, the output signal pressure P of the linear valve 390 is determined according to the actual gear ratio γ from the pre-stored relationship shown in the frame. 1 is determined. This relationship shows that the gear ratio γ quickly reaches its maximum value γ at a necessary and sufficient speed. .

As mentioned above, when the output signal pressure P5olL is set to a large value in the up mode of the second line oil pressure PA2,
The second line oil pressure P12 is the output signal pressure P8°1. Basic output pressure Pyo according to. . Because the pressure is increased from
The first pressure regulating valve 10 is based on the second line oil pressure P12.
The first line oil pressure P i + , which is regulated at 0, is also increased. The vehicle condition at this time is coasting in the neutral range, the vehicle is stopped, and the gear ratio γ is still at its maximum value γ51. In order to avoid reaching PI!, the rapid deceleration shift mode is selected in steps SS4 and SS5 described above, and the secondary hydraulic cylinder 56 is supplied with the first line hydraulic pressure PI! , while the primary side hydraulic cylinder 54 is open to the atmosphere, the first line hydraulic pressure PI! is applied as described above. By further increasing the pressure from the normal pressure regulation value, the gear ratio γ is quickly changed toward γ, .

As described above, according to this embodiment, the shift lever 252
or is operated in the neutral range, and the vehicle speed SPD is less than or equal to the predetermined judgment reference value SPD, 2,
Moreover, the gear ratio γ is a predetermined judgment reference value γ. , if the vehicle is coasting in the neutral range, the vehicle speed is extremely low and the gear ratio γ is still at the lowest deceleration value γ, 8
Since the source pressure control means 480 is not close to
As a result, the source pressure of the speed change control valve device 260, that is, the first line hydraulic pressure P, is increased so that the hydraulic pressure applied to the secondary hydraulic cylinder 56 is increased relative to the primary hydraulic cylinder 54.
A. Or adjusted. For this reason, the secondary hydraulic cylinder 56
As a result, the oil pressure applied to the primary side hydraulic cylinder 54 is adjusted to increase the source pressure of the speed change control valve device 260, and as a result, the speed of the speed change to the maximum deceleration side of the speed ratio γ is increased, and when coasting stops. In advance, the gear ratio γ is immediately set to the maximum deceleration value γ. , X, so immediately after sudden braking operation during coasting in neutral range, shift
Sufficient driving force can be obtained even when restarting by operating the vehicle in the 2nd or 3rd range.

Next, another embodiment of the present invention will be described. In the following description, parts common to those in the above-mentioned embodiments are denoted by the same reference numerals, and the description thereof will be omitted.

FIG. 22 shows another example of the hydraulic control routine. The difference in this figure is that step 5PIl is used instead of step 5PIO of the hydraulic control routine of FIG. 21. In this step 5PII, the output signal pressure P8 of the linear valve 390 is
°IL is taken as its maximum value. In this way, linear valve 39
When the output signal pressure P8°IL of 0 is taken as its maximum value, the second line oil pressure P122 becomes the basic output pressure P, in accordance with the output signal pressure P8°1L, as in the previous embodiment. . Since the pressure is increased from the 1st line and the 1st line oil pressure pH is also increased, the gear ratio γ is immediately set to the maximum deceleration side value γY,X in advance, so sudden braking operation during coasting in the neutral range is not possible. Even if the vehicle is operated into the driving range immediately afterward, sufficient driving force can be obtained when restarting the vehicle.

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, among the primary hydraulic cylinder 54 and the secondary hydraulic cylinder 56,
The first line hydraulic pressure Pl is applied to the driving side hydraulic cylinder, and the second line hydraulic pressure PA2 is applied to the driven side hydraulic cylinder, or the common line hydraulic pressure Pj7 is always applied to the driven side hydraulic cylinder. It may also be a hydraulic circuit. In short, it is only necessary to adjust the source pressure of the speed change control valve device so that the hydraulic pressure applied to the secondary side hydraulic cylinder 56 is increased relative to the primary side hydraulic cylinder 54 in the neutral range coasting stop state. be.

It should be noted that the above-mentioned embodiment is merely one embodiment of the present invention, and various modifications and changes can 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 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. 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 shows 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 C of FIG.
It is a figure explaining the relationship with the shift state of VT. 12th
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, in which FIG. 12 shows the positive torque running state, and FIG. 13 shows the engine brake. FIG. 14 is a diagram showing a running state, and FIG. 14 shows a 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 shows the third solenoid valve in the hydraulic circuit of FIG.
It is a figure which shows the correspondence between the combination of the operating state of a 4th electromagnetic valve, and a linear valve, and each control mode. 20 and 21 are flowcharts illustrating the operation of the electronic control device shown in FIG. 2, with FIG. 20 showing a speed change control routine and FIG. 21 showing a hydraulic control routine, respectively. FIG. 22 is a diagram corresponding to FIG. 21 in another embodiment of the present invention. FIG. 23 is a diagram showing the relationship between vehicle speed and engine rotation speed when the vehicle is coasting in the neutral range. 14: CVT (vehicle belt type continuously variable transmission) 40.42
: Variable pulley 44 : Transmission belt 54 Primary side hydraulic cylinder 56 : Secondary side hydraulic cylinder 252 : Shift lever (shift operation device) 260 : Shift control valve device 462 : Vehicle speed sensor 470 : Operation position sensor 478 : Power connection/disconnection means 482: Gear ratio detection means 480, source pressure control means Fig. 1 Fig. 4 Fig. 6 Fig. 7 1KonU (,1・) Figure 15 Figure 18 Captivity Figure 17 U Soni wo Ben 3'1 Onj, F! Sunt3A l5ott
(A) Figure 23 Kenen SPD

Claims (1)

[Scope of Claims] A power connecting/disconnecting means is provided on the output side, which is placed in a power transmission state when the shift operating device is operated in a travel range, and is in a power transmission cutoff state when the shift operating device is operated in a neutral range. In preparation for this, in a vehicle belt type continuously variable transmission in which the effective diameter of a variable pulley around which a transmission belt is wound is changed by a primary hydraulic cylinder and a secondary hydraulic cylinder, a predetermined relationship is established during deceleration. A hydraulic control device of the type that operates a speed change control valve device to adjust the speed ratio of the belt type continuously variable transmission so that the input shaft rotational speed changes along the operating position of the shift operation device. an operation position sensor for detecting the speed of the vehicle; a vehicle speed sensor for detecting the speed of the vehicle; a gear ratio detection means for detecting the gear ratio of the belt-type continuously variable transmission; When the vehicle speed is below a predetermined judgment reference value and the gear ratio is below a predetermined judgment reference value, the hydraulic pressure applied to the secondary hydraulic cylinder is changed to the primary hydraulic cylinder. A hydraulic control device for a belt-type continuously variable transmission for a vehicle, comprising: source pressure control means for adjusting the source pressure of the speed change control valve device so as to be higher than that of the side hydraulic cylinder.