JP2586652B2 - Hydraulic control device for automatic transmission for vehicles - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a hydraulic control device for an automatic transmission for a vehicle.

2. Description of the Related Art There is known an automatic transmission for a vehicle in which power of an engine is transmitted to driving wheels via a gear device that is automatically switched to a reverse gear. For example, a stepped transmission having a reverse gear stage, a belt-type continuously variable transmission having a forward / reverse switching gear device, and the like are examples thereof. In such an automatic transmission for a vehicle, a hydraulic control circuit of a type for supplying a hydraulic pressure for establishing a reverse gear to the reverse hydraulic actuator in connection with the operation of the shift operation member to the reverse operation position is provided. I have. An example is a hydraulic control device described in Japanese Patent Application Laid-Open No. 64-49749.

Then, when the shift operation member is operated from the forward range to the reverse range by passing through the neutral range in the vehicle traveling forward, the transmission of the vehicle traveling forward is automatically switched to the reverse gear. While a sudden load is applied, the drivability may be impaired by a shock. In contrast, as described in the specification of Japanese Patent Application No. 63-34598 previously filed by the present applicant, a retraction preventing valve is provided in an oil passage to which hydraulic pressure is supplied to a reverse hydraulic actuator, A hydraulic control device has been proposed which is provided with an electromagnetic valve for generating a signal pressure for driving the retraction stop valve, and switches the retraction stop valve to the stop position when the shift operation member is operated to the reverse position while the vehicle is moving forward. Have been.

Problems to be Solved by the Invention By the way, in the conventional hydraulic control circuit as described above, the signal pressure is generally generated by signal pressure generating means including an electromagnetic valve driven by an electric signal from a control device. It is configured to be. However, an automatic transmission for a vehicle is required to perform a plurality of controls in accordance with a command from an electronic control. However, if a signal pressure generating means for each control is provided, a hydraulic control circuit becomes complicated and large. There was a disadvantage.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide at least a signal pressure generated for preventing retraction, when the shift operation member is not operated to the retreat position, for another purpose. It is an object of the present invention to provide a hydraulic control device for an automatic transmission for a vehicle, which can be used also for this purpose.

Means for Solving the Problems The gist of the present invention for achieving the above object is to provide a vehicle for transmitting power of an engine to drive wheels via a gear device automatically switched to a reverse gear. In the automatic transmission, a hydraulic control device of a type for supplying a hydraulic pressure for establishing the reverse gear to a reverse hydraulic actuator in association with an operation of a shift operation member to a reverse operation position, wherein (1) the shift A switching valve that is switched in relation to the operation of the operating member, outputs a hydraulic pressure for establishing the reverse gear when the shift operating member is operated to the reverse operation position, and (2) is operated by an electric signal. Signal pressure generating means having an electromagnetic valve for generating a signal pressure for preventing a reverse gear from being established during forward running according to the electric signal; (3) the reverse hydraulic actuator When the signal pressure and the hydraulic pressure for establishing the reverse gear are simultaneously supplied, the switch is switched to a blocking position for preventing the reverse gear from being established. A reverse blocking valve that is positioned at a non-blocking position that allows the reverse gear to be established when at least one of the pressure and the hydraulic pressure for establishing the reverse gear is not supplied.

In this manner, the reverse blocking valve is in the blocking position for preventing the reverse gear from being established when the signal pressure generated in accordance with the electric signal and the hydraulic pressure for establishing the reverse gear are simultaneously supplied. , The signal pressure can be used for other purposes. Therefore, the common signal pressure generating means can be used for a plurality of control purposes, and the hydraulic circuit is simplified.

Even if an abnormality occurs in the signal pressure generating means and the signal pressure is generated in a condition not to prevent the establishment of the reverse gear, the hydraulic pressure for preventing the establishment of the reverse gear is output from the switching valve. Unless this is done, the reverse blocking valve cannot be located at the blocking position for preventing the reverse gear from being established.

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

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

The fluid coupling 12 includes a pump impeller 28 connected to the crankshaft 26 of the engine 10, a turbine impeller 32 fixed to the input shaft 30 of the CVT 14 and rotated by oil from the pump impeller 28, and a damper 34. A lock-up clutch 36 fixed to the input shaft 30 via an engagement-side oil passage 33 connected to an engagement-side oil passage 322 described later and a release-side oil chamber 35 connected to a release-side oil passage 324 described later. And The inside of the fluid coupling 12 is always filled with hydraulic oil.For example, when the vehicle speed becomes equal to or higher than a predetermined value, or when the rotation speed difference between the pump impeller 28 and the turbine impeller 32 becomes equal to or lower than the predetermined value, the engagement side oil is filled. When the hydraulic oil is supplied to the chamber 33 and the hydraulic oil flows out from the release-side oil chamber 35, the lock-up clutch 36
And the input shaft 30 of the crankshaft 26 is directly connected. Conversely, when the vehicle speed or the like becomes equal to or lower than a predetermined value, the hydraulic oil is supplied to the release-side oil chamber 35 and the hydraulic oil flows out of the engagement-side oil chamber 33, so that the lock-up clutch 36 is released. .

The CVT 14 includes variable pulleys 40 and 42 having the same diameter provided on the input shaft 30 and the output shaft 38, respectively, and a transmission belt 44 wound around the variable pulleys 40 and 42. The variable pulleys 40 and 42 are provided on the 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 and to be unable to rotate relative to the axis. Movable rotating body 50 and
52, the movable rotary members 50 and 52 are moved by the primary hydraulic cylinder 54 and the secondary hydraulic cylinder 56 functioning as hydraulic actuators, so that the V-groove width, that is, the hanging diameter (effective diameter) of the transmission belt 44 is reduced. The speed ratio e of the CVT 14 (= the rotation speed N _out of the output shaft 38 / the rotation speed N _in of the input shaft 30) is changed.
Since the variable pulleys 40 and 42 have the same diameter, the hydraulic cylinders 54 and 56 have the same pressure receiving area. Normal,
The pressure of the hydraulic cylinders 54 and 56 located on the driven side is related to the tension of the transmission belt 44.

The forward / reverse switching device 16 is a well-known double pinion type planetary gear mechanism, and includes a pair of planetary gears 62 and 64 rotatably supported by a carrier 60 fixed to an output shaft 58 thereof and meshing with each other. Planetary gear 6 fixed to the input shaft (output shaft of CVT 14) 38 of the
2, a sun gear 66 meshing with 2, a ring gear 68 meshing with the planetary gear 64 on the outer peripheral side, a reverse brake 70 for stopping rotation of the ring gear 68, the carrier 60 and the input shaft 38 of the forward / reverse switching device 16 are connected. And a forward clutch 72 to be driven. The reverse brake 70 and the forward clutch 72 are friction engagement devices of a type operated by hydraulic pressure.
Is set to a neutral state, and power transmission is interrupted. However, when the forward clutch 72 is engaged, the output shaft 38 of the CVT 14 is
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. When the reverse brake 70 is engaged, the output shaft 38 of the CVT 14 and the forward / reverse switching device 16
The rotation direction is reversed between the output shaft 58 and the output shaft 58, so that the power in the vehicle backward direction is transmitted.

FIG. 1 is a second diagram for controlling a vehicle power transmission device.
2 shows the hydraulic control circuit of the figure in detail. Oil pump 74
, Which constitutes a hydraulic pressure source of the hydraulic control circuit, is connected integrally with a pump impeller 28 of the fluid coupling 12 so as to be constantly rotated by the crankshaft 26. The oil pump 74 sucks the working oil returned to the oil tank (not shown) through the strainer 76, and sucks the working oil returned through the return oil passage 78 and sends it to the first line oil passage 80 under pressure. . In the present embodiment, the hydraulic oil in the first line oil passage 80 is leaked to the return oil passage 78 and the lock-up clutch pressure oil passage 92 by the overflow (relief) type first pressure regulating valve 100, so that the first line oil is discharged. The first line oil pressure Pl ₁ in the oil passage 80 is adjusted. Further, the second line pressure Pl ₁ is reduced by the second pressure regulating valve 102 of the pressure reducing valve type, so that the second pressure
The second line oil pressure Pl ₂ in the line oil passage 82 is adjusted.

First, the configuration of the second pressure regulating valve 102 will be described. As shown in FIG. 3, the second pressure regulating valve 102 is connected to the first line oil passage 80 and the second line oil passage 80.
Spool valve element 110 that opens and closes with line oil passage 82, spring seat 112, return spring 114, plunger
It has 116. The first land 118, the second land 120, and the third land 12 having the larger diameter are sequentially provided on the shaft end of the spool valve element 110.
2 are sequentially formed. 2nd land 120 and 3rd land 12
2, a chamber 126 is provided in which the second line oil pressure Pl ₂ is introduced as a feedback pressure through the throttle 124.
Spool 110 is adapted to be urged in the valve closing direction by the second line pressure Pl _2. Also, the spool valve 110
On the end face side of the first land 118, a chamber 130 into which a speed specific pressure Pe described later is guided via a throttle 128 is provided, and the spool valve element 110 is urged in the valve closing direction by the speed specific pressure Pe. It has become so. In the second pressure regulating valve 102, the urging force of the return spring 114 in the valve opening direction is applied to the spring seat 1.
It is provided to the spool valve 110 via 12. Also,
A land 117 and a land 119 having a slightly larger diameter are formed on the plunger 116, and a chamber 132 for applying a later-described throttle pressure P _th is provided on an end face side of the land 117, and a spool valve is provided. The child 110 is urged in the valve opening direction by the throttle pressure _Pth .

Therefore, the pressure receiving area of the first land 118 is A ₁ , the cross-sectional area of the second land 120 is A ₂ , the cross-sectional area of the third land 122 is A ₃ , the pressure receiving area of the land 117 of the plunger 116 is A ₄ , and the return is performed. Assuming that the urging force of the spring 114 is W, the spool valve element 110 is basically balanced at a position where the following equation (1) is satisfied. That is, the spool valve 110 is expressed by the following equation (1).
In the first line oil passage 80 guided to the port 134a,
And a state in which the hydraulic oil in the second line oil passage 82 guided to the port 134b flows into the drain port 134c communicating with the drain, and , The second line hydraulic pressure Pl ₂ is generated. Since the second line oil passage 82 is a relatively closed system, the second pressure regulating valve 102 and the second line pressure by reducing the pressure of the first line pressure Pl ₁ is a relatively high pressure as above Pl ₂ is generated as shown in FIG.

Pl ₂ = (A ₄ · P _th + W-A ₁ · Pe) / (A ₃ -A ₂ ) (1) Note that the first land 118 and the second land 120 of the spool valve element 110 are connected to each other. Between them, there is provided a chamber 136 into which a signal pressure P _sol5 is introduced through a first relay valve 380 described later. When the spool valve element 110 is urged in the valve closing direction by the signal pressure P _sol5 , the The second line hydraulic pressure Pl ₂ is reduced according to the magnitude. The first relay valve 380 is provided between the land 117 and the land 119 of the plunger 116.
And a control pressure via a second relay valve 440 and a throttle 135 described later.
A chamber 133 for operating P _sol5 is provided.
The line pressure Pl ₂ is adapted to be boosted in response to the signal pressure P _SOL5. The characteristics of the second line hydraulic pressure in the above case will be described later in detail.

As shown in FIG. 4, the first pressure regulating valve 100 includes a spool valve element 140, a spring seat 142, and a return spring 14.
4, the first plunger 146, and the first plunger 146
And a second plunger 148 having the same diameter as the second land 155. The spool valve element 140 opens and closes between a port 150a communicating with the first line oil passage 80 and a drain port 150b or 150c. A first line oil pressure Pl as a feedback pressure is provided on an end surface of the first land 152. squeeze ₁ 151
The first line oil pressure Pl ₁ urges the spool valve element 140 in the valve opening direction. A chamber for guiding the throttle pressure P _th is provided between the first land 154 and the second land 155 of the first plunger 146 provided coaxially with the spool valve element 140.
156 is provided, also, pressure P _in in the primary-side hydraulic cylinder 54 is provided between the second land 155 and the second plunger 148
157 is provided through the branch oil passage 305, and a chamber 158 for guiding the second line oil pressure Pl ₂ is provided at the end face of the second plunger 148. Since the urging force of the return spring 144 is applied to the spool valve element 140 via the spring seat 142 in the valve closing direction, the pressure receiving area of the first land 152 of the spool valve element 140 is A ₅ ,
The cross-sectional area of the first land 154 of the first plunger 146 is A ₆ ,
Assuming that the cross-sectional area of the land 155 and the second plunger 148 is A ₇ and the urging force of the return spring 144 is W, the spool valve element 140 is balanced at a position where the following equation (2) holds, and the first line hydraulic pressure Pl ₁ Is regulated.

Pl ₁ = _{[(P in or Pl 2) ·} A 7 + P th (A 6 -A 7) + W ] / A ₅ ···· (2) In the first pressure regulating valve 100, the primary-side hydraulic cylinder 54
When the inner pressure P _in is higher than (Pl ₂ = secondary side in the hydraulic cylinder 56 pressure P _out at steady state) the second line pressure Pl ₂ is
The first plunger 146 is thrust by the apart from hydraulic P _in the above primary side hydraulic cylinder 54 between the second plunger 148 acts in the closing direction of the spool 140, the primary hydraulic cylinder 54 hydraulic P _in Is lower than the second line hydraulic pressure Pl ₂ , the first plunger 146 and the second plunger 148 come into contact with each other. Therefore, the thrust due to the second line hydraulic pressure Pl ₂ acting on the end face of the second plunger 148. Acts in the valve closing direction of the spool valve element 140. That is, the primary hydraulic cylinder 54
The second plunger 148 which receives the inner pressure P _in the second line pressure Pl ₂ is of exerting an action force based on the hydraulic pressure of the higher of those pressure in the closing direction of the spool 140. A chamber 160 provided between the first land 152 and the second land 159 of the spool valve element 140 is opened to drain.

Returning to FIG. 1, the throttle pressure P _th represents the actual throttle valve opening θ _th in the engine 10 and is generated by the throttle valve opening detection valve 180. The speed specific pressure Pe represents the actual speed ratio of the CVT 14 and is generated by the speed ratio detection valve 182. The throttle valve opening detection valve 180 includes a cam 184 that rotates together with a throttle valve (not shown), and a plunger 186 that engages with a cam surface of the cam 184 and is driven in the axial direction in relation to the rotation angle of the cam 184. And the thrust from the plunger 186 applied via the spring 188 and the thrust by the first line oil pressure Pl ₁ are positioned at a balanced position, thereby reducing the first line oil pressure Pl ₁ and opening the actual throttle valve. and a spool valve 190 to generate a throttle pressure P _th corresponding to degrees theta _th. FIG. 5 shows a relationship between the throttle pressure P _th and the actual throttle valve opening θ _th , and the throttle pressure P _th passes through the oil passage 84 to the first pressure regulating valve 100,
The pressure is supplied to the second pressure regulating valve 102, the third pressure regulating valve 220, and the lock-up clutch pressure regulating valve 310, respectively.

Also, the speed ratio detection valve 182 is an input-side movable rotating body of the CVT14.
A detecting rod 192 which is slidably in contact with 50 and is moved in the axial direction by a displacement amount equal to the axial displacement amount thereof;
A spring 194 that transmits an urging force corresponding to the position of
A spool valve element 198 is provided which receives the urging force from the spring 194 and receives the second line oil pressure Pl ₂ and is positioned at a position where both thrusts are balanced, thereby changing the discharge flow rate to the drain. I have. Therefore, for example, when the speed ratio e increases and the movable rotator 50 approaches the fixed rotator 46 on the input side of the CVT 14 (reduces the V-groove width), the detection rod 192 is pushed. Therefore, the flow rate of the hydraulic oil supplied from the second line oil passage 82 through the orifice 196 and discharged to the drain by the spool valve 198 is reduced, so that the hydraulic pressure downstream of the orifice 196 is increased. This operating oil pressure is the speed specific pressure Pe, and is increased as the speed ratio e increases, as shown in FIG. Then, the speed specific pressure Pe generated in this way passes through the oil passage 86 to the second pressure regulating valve 102 and the third pressure regulating valve 102.
Each is supplied to the pressure regulating valve 220.

Here, the speed ratio detection valve 182 is connected to the second line oil pressure Pl supplied from the second line oil passage 82 through the orifice 196.
_The speed specific pressure P
e, the speed specific pressure Pe is limited to be equal to or more than the second line oil pressure Pl ₂ ,
In the second pressure regulating valve 102 that operates according to the above equation (1), the second line oil pressure Pl ₂ is decreased with an increase in the speed specific pressure Pe. Therefore, when the speed ratio pressure Pe is equal to the second line pressure Pl ₂ increases to a predetermined value, is constant with saturated Both later. Figure 7, in the second pressure regulating valve 102, shows the output characteristic of the second line pressure Pl ₂ that pressure regulated in conjunction with the above speed ratio pressure Pe. That is, the speed ratio e
The characteristic approximating the ideal curve for making the tension of the transmission belt 44 shown in FIG. 8 required for the low-pressure side line hydraulic pressure as the optimum value can be obtained only by the hydraulic circuit.
The hydraulic circuit as compared with the case of generating the second line pressure Pl ₂ with electromagnetic pressure control servo valve which is continuously controlled is advantageous to be considerably cheaper.

The third pressure regulating valve 220 generates an optimal third line hydraulic pressure Pl ₃ for operating the reverse brake 70 and the forward clutch 72 of the forward / reverse switching device 16. The third pressure regulating valve 220 is connected to the first line oil passage 80 and the third line oil passage 8.
Spool valve 222 that opens and closes between 8 and spring seat
224, a return spring 226, and a plunger 228. A first land 230 of the spool 222 between the second land 232 and the introduced chamber 236 is provided through the third line pressure Pl ₃ are squeezed as a feedback pressure 234, the spool valve element 222 is a third It is adapted to be urged in the valve closing direction by the line pressure Pl _3. On the first land 230 side of the spool valve 222, there is provided a chamber 240 into which the speed specific pressure Pe is guided via the throttle 238.
22 is urged in the valve closing direction by the speed specific pressure Pe. In the third pressure regulating valve 220, the urging force of the return spring 226 in the valve opening direction is applied to the spool valve 222 via the spring seat 224. Also, plunger 2
The end face 28 and the chamber 242 for applying a throttle pressure P _th is provided, the spool valve element 222 is the throttle pressure P
_The valve is biased in the valve opening direction by _th . Further, the third line hydraulic pressure P is provided only between the first land 244 of the plunger 228 and the second land 246 having a smaller diameter than the third land
chamber 248 for guiding l ₃ is provided. Therefore, the third line pressure Pl _3, the equation (1) similar expression is of being pressure regulated to the optimum value based on the speed ratio pressure Pe and the throttle pressure P _th. The optimum value is a necessary and sufficient value to ensure that torque can be transmitted without slippage in the forward clutch 72 or the reverse brake 70. In reverse, the above room
Since the 248 third line pressure Pl ₃ is guided, third line pressure Pl ₃ are increased force for biasing the spool valve element 222 in the valve opening direction is increased. As a result, in the forward clutch 72 and the reverse brake 70, a torque capacity suitable for each of forward travel and reverse travel can be obtained.

The third line pressure Pl ₃ pressure regulated as described above, is adapted to be selectively supplied to the forward clutch 72 or reverse brake 70 by the manual valve 250.
That is, the manual valve 250 is provided with the spool valve element 254 that is moved in association with the operation of the shift lever 252 of the vehicle.
In the state where the motor is operated to the forward range such as the L (low), S (second), and D (drive) range, the third line hydraulic pressure Pl ₃ is exclusively output from the output port 258 for forward movement. The oil is supplied from the reverse brake 70 to the drain simultaneously with the supply to the clutch 72. On the other hand, when the operation is in the R (reverse) range, the third line
Pl ₃ is supplied from the output port 256 to the ports 422a and 422b of the reverse inhibit valve 420, and further supplied to the reverse brake 70 through the reverse inhibit valve 420, and at the same time, the drainage from the forward clutch 72 is permitted, and N ( When the clutch is operated to the neutral) and P (parking) ranges, the forward clutch 72 and the reverse brake 70
Oil drain from both is allowed. The accumulator 342
And 340 are for gradually raising the hydraulic pressure to smoothly advance the frictional engagement, and the forward clutch 72
And a reverse brake 70. The shift timing valve 210 adjusts the transitional inflow flow rate by closing the throttle 212 in accordance with the increase in the hydraulic pressure in the hydraulic cylinder of the forward clutch 72.

The first line hydraulic pressure P regulated by the first pressure regulating valve 100
The primary line hydraulic cylinder 54 and the secondary side hydraulic cylinder 56 are controlled by the transmission control valve device 260 in order to adjust the speed ratio e of the CVT 14 by adjusting the second line hydraulic pressure Pl ₂ adjusted by the _first and second pressure adjusting valves 102. To one and the other. The shift control valve device 260 includes a shift direction switching valve 262 and a flow control valve 264. The fourth line oil pressure Pl ₄ for driving the shift direction switching valve 262 and the flow rate control valve 264 is generated by the fourth pressure regulating valve 170 based on the first line oil pressure Pl ₁ , and the fourth line oil passage 370 Is to be guided by.

The fourth pressure regulating valve 170 includes a spool valve element 171 that opens and closes between the first line oil path 80 and the fourth line oil path 370, and a spring 172 that biases the spool valve element 171 in the valve opening direction. Have. Between the first land 173 and the second land 174 of the spool valve element 171, there is provided a chamber 176 for introducing a fourth line oil pressure Pl ₄ to act as a feedback pressure, while the spring of the spool valve element 171 is provided. On the end face side of the plunger 175 abutting on the 172 side end, there is provided a chamber 177 for introducing a signal pressure P _sol5 described below, which acts in the valve opening direction,
The end face of the spool valve element 171 on the non-spring 172 side is open to the atmosphere. In the fourth pressure regulating valve 170 constructed as described above, the spool valve element 171, the biasing force of the valve closing direction based on the feedback pressure corresponding to the fourth line pressure Pl _4, the biasing force of the valve opening direction by a spring 172 and the results and the biasing force of the valve opening direction based on the signal pressure P _SOL4 are operated so as to balance and pressure is adjusted to a value fourth line pressure Pl ₄ is corresponding to the magnitude of the signal pressure P _SOL5 below.

As shown in detail in FIG. 9, the shift direction switching valve 262 is
A spool valve controlled by the first solenoid valve 266, the drain port 278 a communicating with the drain, the first connection oil passage 270, the second connection oil passage 272 having the first throttle 271, and the third connection oil Ports 278b, 278 communicating with road 274, respectively
d, and the 278F, and the port 278c which is supplied through the first line pressure Pl ₁ is stop 276, and the port 278e which first line pressure Pl ₁ is supplied, and a port 278g of the hydraulic Pl ₂ is the second line is supplied Slidable between a deceleration side position (on side position) which is one end of the movement stroke (upper end in the figure) and a speed increasing side position (off side position) which is the other end (the lower end in the figure) of the movement stroke. A spool valve element 280 is provided, and a spring 282 for urging the spool valve element 280 toward the speed increasing position. In the spool valve element 280,
Four lands 279a, 279b, 279c, 279d are provided.
The end face of the spool valve element 280 on the spring 282 side is open to the atmosphere. However, when the first solenoid valve 266 is in the ON state, that is, in the closed state, the fourth line oil pressure Pl ₄ regulated by the fourth pressure regulating valve 170 is provided on the end face on the lower end side of the spool valve element 280.
When the first solenoid valve 266 is in the off state, that is, in the open state, the pressure downstream of the throttle 284 is exhausted, and the fourth
Line pressure Pl ₄ are made unusable to act. When the first solenoid valve 266 is in the state shown on the side in the figure, the shift direction switching valve 262 is also in the position shown on the side in the figure, and when the first solenoid valve 266 is in the state shown on the side in the figure, the shift direction is switched. Valve 262 also
This is the position shown on the OFF side. Therefore, while the first solenoid valve 266 is in the ON state, the spool valve element 280 is positioned at the deceleration side position, and the drain port 278a and the port 278b
Between ports 278e and 278f, respectively, and between ports 278b and 278c, and between ports 278d and 278c.
278e and between the ports 278f and 278g are closed, but during the period when the first solenoid valve 266 is in the off state, the spool valve element 280 is located at the speed increasing side position and switching is performed in the opposite manner as described above. State.

The flow control valve 264 is a spool valve controlled by the second solenoid valve 268, and functions as a shift speed control valve in the present embodiment. The flow control valve 264 communicates with the primary hydraulic cylinder 54 via the primary oil passage 300 and the second connection oil passage 2.
Port 286a communicating with the second connecting oil passage 270 and ports 286b and 286 communicating with the first connecting oil passage 274 and the third connecting oil passage 274, respectively.
d, a port 286c communicating with the secondary side hydraulic cylinder 56 via the secondary side oil passage 302, and a flow rate non-restriction side position and a movement stroke in the speed increasing speed mode which is one end (upper end in the figure) of the movement stroke. A spool valve element 288 slidably disposed between the other end (lower end in the figure) and the flow rate suppression side position in the speed-up shift mode, and the spool valve element 288 is moved toward the flow rate suppression side position. And a biasing spring 290. The spool valve element 288 is provided with three lands 287a, 287b, 287c for opening and closing the ports. Similar to the shift direction switching valve 262, the end surface of the spool valve element 288 on the spring 290 side is not subjected to hydraulic pressure because it is released to the atmosphere. However, on the lower end surface of the spool valve element 288, the ON state of the second solenoid valve 268,
That is in the closed state caused to fourth line pressure Pl ₄ action pressure regulated by the fourth pressure regulating valve 170, off state, i.e. the fourth line pressure Pl ₄ action downstream side is pressurized discharge than 292 stop in the open state You will not be allowed to do so. 2nd solenoid valve 2
When the state 68 is on the ON side in the figure, the flow control valve 264 is in the operating position on the ON side in the figure, and the second solenoid valve 268 is turned off in the figure.
When the state shown on the side is reached, the flow control valve 264 is in the operating position shown on the OFF side in the figure. Therefore, the second solenoid valve 268
Is in the ON state (duty ratio is 100%), the spool valve element 288 is located at the flow rate non-restriction side position, and the ports 286a and 286b and the ports 286c and 286d are opened. However, during the period when the second solenoid valve 268 is in the off state (duty ratio is 0%), the spool valve 288
Is located at the flow suppression side position, and the switching state is reversed.

The secondary hydraulic cylinder 56 is connected to a throttle
It is connected to the second line oil passage 82 via a bypass oil passage 295 provided with a check valve 296 and a check valve 298. The check valve 298 is supplied when the first line hydraulic pressure Pl ₁ is supplied to the secondary hydraulic cylinder 56 during a deceleration shift in which the pressure in the secondary hydraulic cylinder 56 is relatively high or during engine braking. In addition, the hydraulic oil in the secondary hydraulic cylinder 56 is prevented from flowing out into the second line oil passage 82 in a large amount, and the hydraulic pressure P _out (= Pl ₁ ) in the secondary hydraulic cylinder 56 is not decreased, and the speed is gradually reduced. This is for supplying hydraulic oil from the second line hydraulic pressure Pl ₂ into the secondary hydraulic cylinder 56 during gear shifting. Further, the diaphragm 296 and the check valve 298, pulsation caused in the hydraulic P _out in the secondary-side hydraulic cylinder in synchronism with the duty drive of the flow control valve 264 is preferably alleviated. That is, the peak on the spike in the pulsation of the secondary-side hydraulic cylinder in the hydraulic P _out is released by squeezing 296, under the peak of P _out is because is compensated through the check valve 298. The check valve 298 includes a valve seat 299 having a planar seating surface, a valve 301 having a planar contact surface abutting on the seat, and the valve 301 facing the valve seat 299. And a spring 303 which is urged to open by a pressure difference of about 0.2 kg / cm ² . In addition, the primary oil passage 30
At 0, a second throttle 273 is provided between the junction of the second connection oil passage 272 and the branch point of the branch oil passage 305. Here, the aperture 273 determines the speed at the time of the rapid deceleration shift, and is set to be the maximum speed within a range in which the transmission belt 44 does not slip at the time of the rapid deceleration shift. The aperture 271 and the aperture 296 determine the speed at the time of a gradual increase, and the aperture 276 determines the speed at the time of a rapid increase.

Therefore, when the first solenoid valve 266 is on,
Regardless of the operation state of the second solenoid valve 268, the speed ratio e of CVT14
Is changed in the deceleration direction. For example, when the second solenoid valve 268 is in the ON state, the operating oil in the first line oil passage 80 is supplied to the port 278e, the port 278f, and the third connection oil passage 27.
4, while flowing into the secondary hydraulic cylinder 56 through the port 286d, the port 286c, and the secondary hydraulic passage 302, the hydraulic oil in the primary hydraulic cylinder 54 is supplied to the primary hydraulic passage 300, the port 286.
a, the port 286b, the first connection oil passage 270, the port 278b, and the drain port 278a are discharged to the drain. This allows
As shown in FIG. 10 (a), the speed ratio e is rapidly changed in the deceleration direction.

When the second solenoid valve 268 is turned off while the first solenoid valve 266 is on, the second line oil passage 8
2 is supplied into the secondary hydraulic cylinder 56 through a throttle 296 and a check valve 298 provided in parallel in a bypass oil passage 295, and is also supplied to the primary hydraulic cylinder 54.
Hydraulic oil inside is gradually or positively discharged from a sliding portion of the piston or the like through a small gap formed inevitably. As a result, the speed ratio e is gradually changed in the deceleration direction as shown in FIG.

When the first solenoid valve 266 is on, the second
When the solenoid valve 268 is duty-driven, the speed is intermediate between (a) and (c). Therefore, the speed ratio e is changed to the deceleration side at a speed corresponding to the duty ratio of the second solenoid valve 268. Can be FIG. 10 (b) shows this state.

Conversely, when the first solenoid valve 266 is off, the second
Regardless of the operating state of the solenoid valve 268, the speed ratio e of the CVT 14 is changed in a speed increasing direction (a direction in which the speed ratio e increases). For example, if the second solenoid valve 268 is turned on while the first solenoid valve 266 is off, the first line oil passage 80
Hydraulic oil inside is the throttle 276, port 278c, port 278b, first connection oil passage 270, port 286b, port 286a, primary oil passage 3
00 and into the primary side hydraulic cylinder 54, the port 278e, the port 278d, the second connection oil passage 272,
Hydraulic oil in the secondary hydraulic cylinder 56 flows into the primary hydraulic cylinder 54 through the primary hydraulic passage 300, while the hydraulic fluid in the secondary hydraulic cylinder 56 flows through the secondary hydraulic passage 302, the port 286 c, the port 286 d,
74, port 278f, port 278g, second line oilway 82
Is discharged to As a result, the speed ratio e is quickly changed to the speed increasing method as shown in FIG.

Also, if the second solenoid valve 268 is turned off while the first solenoid valve 266 is off, the first connection oil passage 270
Is closed by the flow control valve 264, the hydraulic oil in the first line oil passage 80 is exclusively supplied to the primary hydraulic cylinder 54 through the second connection oil passage 272 provided with the first throttle 271, and The hydraulic oil in the hydraulic cylinder 56 is gradually discharged to the second line oil passage 82 through the throttle 296. Therefore, the action of the first throttle 271 and the throttle 296 causes the tenth
The speed ratio e is gradually changed in the speed increasing direction as shown in FIG.

When the first solenoid valve 266 is in the off state, the second
When the solenoid valve 268 is duty-driven, the speed is intermediate between the above (f) and (d), so that the speed ratio e changes to the speed increasing side at a speed corresponding to the duty ratio of the second solenoid valve 268. Let me do. FIG. 10E shows this state.

Here, the first line oil pressure Pl ₁ in the CVT 14 is desirably set to a hydraulic pressure value as shown in FIG. 11 during forward drive running (when the drive torque T is positive), and when the engine brake runs (drive torque T). When T is negative), a hydraulic pressure value as shown in FIG. 12 is desired. FIGS. 11 and 12 show the state in which the input shaft 30 is rotated with a constant shaft torque and the speed ratio e
Are shown when the pressure is changed within the entire range. In this embodiment, the primary hydraulic cylinder 54
And the secondary-side hydraulic cylinder 56 have the same pressure receiving area.
Hydraulic P _in in the primary-side hydraulic cylinder 54 to the positive drive traveling of FIG.
> The hydraulic pressure P _out in the secondary hydraulic cylinder 56, and P _out > P _in when the engine brake is running in FIG. 12, and in each case, the hydraulic pressure in the driving hydraulic cylinder> the hydraulic pressure in the driven hydraulic cylinder. Since the P _in during the positive drive running is one which generates the thrust of the drive side of the hydraulic cylinder, so the thrust for the hydraulic cylinder to obtain the speed ratio of the target may occur, also reduce the power loss to the first line pressure Pl ₁ is be pressure regulated to a value obtained by adding and sufficient margin hydraulic α required for the P _in is desired. However, it is impossible to regulate the first line hydraulic pressure Pl ₁ shown in FIGS. 11 and 12 based on the hydraulic pressure in one hydraulic cylinder,
Therefore, in this embodiment, the first pressure regulating valve 100 is
Plunger 148 is provided, P _in and a second line pressure Pl
_The biasing force based on the higher oil pressure of any one of the _two
00 is transmitted to the spool valve element 140.
Thus, for example, as shown in FIG. 13, at the time of no-load running which is a curve showing the curve and P _out showing a P _in cross, first line pressure Pl ₁ is P _in and a second line pressure Pl
_The hydraulic pressure is controlled to a value obtained by adding the margin value α to the higher oil pressure value of any of ₂ . Thus, the first line hydraulic pressure Pl ₁ is controlled to a necessary and sufficient value, and the power loss is reduced as much as possible.
Incidentally, the first line oil pressure Pl ₁ ′ shown by the broken line in FIG.
In the case where the plunger 148 is not provided,
In the range where the speed ratio e is large, an unnecessarily large margin hydraulic pressure is generated.

The margin value α is set to a desired speed ratio e by changing the speed ratio e at a desired speed within the entire speed ratio change range of the CVT 14.
, And as is apparent from the equation (2), the first line oil pressure Pl ₁ is increased in relation to the throttle pressure P _th . The pressure receiving area of each part of the first pressure regulating valve 100 and the urging force of the return spring 144 are set as such. At this time, the first pressure regulating valve
The first line pressure Pl ₁ to pressure regulated by the 100, as shown in FIG. 14, but increases as the P _in or P _out and the throttle pressure P _th, saturated at the maximum value corresponding to the throttle pressure P _th It is made to be made. As a result, the speed ratio e becomes the maximum value and the V of the primary side variable pulley 40
While a decrease in the groove width is mechanically blocked, even if the hydraulic pressure P _in in the primary-side hydraulic cylinder 54 is increased, the first line pressure Pl ₁ over which it always higher controlled by margin value α than The boost is prevented.

Returning to FIG. 1, the hydraulic oil flowing out from the port 150b of the first pressure regulating valve 100 is supplied to the lock-up clutch pressure oil passage 92.
The lock-up clutch pressure regulating valve 310 regulates the lock-up clutch oil pressure P _{cl at} a pressure suitable for operating the lock-up clutch 36 of the fluid coupling 12. That is, the lock-up clutch pressure regulating valve 310 receives the lock-up clutch oil pressure _Pcl as feedback pressure and is urged in the valve opening direction, and urges the spool valve element 312 in the valve closing direction. Spring 314 and a chamber to which the throttle pressure P _th is supplied
316, and a plunger 317 that urges the spool valve element 312 in the valve closing direction by receiving the hydraulic pressure of the chamber 316, and the spool valve element 312 balances the thrust based on the feedback pressure with the thrust of the spring 314. As a result, the hydraulic oil in the lock-up clutch pressure oil passage 92 is caused to flow out, thereby generating a lock-up clutch oil pressure _Pcl that increases in accordance with the throttle pressure _Pth . 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 hydraulic oil flowing out of the lock-up clutch pressure regulating valve 310 is sent out through the throttle 318 and the lubricating oil passage 94 for lubrication of each part of the transmission, and
The oil is returned to the return oil passage 78.

The third solenoid valve 330 discharges the pressure downstream of the throttle 331 to the drain in the off state and the fourth solenoid valve in the on state.
Signal pressure of the same pressure as the fourth line oil pressure Pl _{4 in} line oil passage 370
_Generates P _sol3 . The fourth solenoid valve 346 is the signal pressure P of the same pressure as the fourth line pressure Pl ₄ in its on state and to exhaust pressure downstream than 344 stop in its off state to the drain
_{Generate sol4} . The fifth solenoid valve 392 discharges the pressure downstream of the throttle 394 in the off state and generates the same signal pressure P _sol5 as the fourth line oil pressure Pl ₄ in the on state.
In the present embodiment, the following signal _engagements P _sol3 , P _sol4 , and P _sol5 are used in combination with the following lock-up clutch engagement and sudden release control, accumulator back pressure control, N range line hydraulic pressure down control, A plurality of types of control such as line hydraulic pressure down control and reverse inhibit control are executed.

The lock-up clutch control valve 320 and the lock-up clutch rapid release valve 400 related to the engagement and rapid release control of the lock-up clutch 36 will be described. The lock-up clutch control valve 320 _{supplies the} hydraulic oil in the oil passage 92 adjusted to the lock-up clutch oil pressure P _cl to the fluid coupling 12.
Of the lock-up clutch 36 in an engaged state or a released state by selectively supplying the lock-up clutch 36 to an engaged state or a released state.
Reference numeral 400 denotes a device for releasing the lock-up clutch 36 quickly by draining the hydraulic oil flowing out when the lock-up clutch 36 is released without passing through the oil cooler 399.

The lock-up clutch control valve 320 is a spool valve of a two-position operation type. When the lock-up clutch 36 is engaged (on side in the drawing: second position), a port to which the lock-up clutch hydraulic pressure _Pcl is supplied. 321c and port 321d,
Port 321b and drain port 321a, port 321e and port 32
When the lock-up clutch 36 is released (off side in the figure: the first position), the port 321c and the port 321 are connected.
b, spool valve element 326 for connecting port 321d and port 321e, port 321f and drain port 321g, and spool valve element 3
And a spring 328 for urging the spring 26 toward the release side (off side). The lower end side of the spool valve element 326 (non-spring 3
On the 28th side), there is provided a chamber 332 into which a signal pressure P _sol3 generated when the third solenoid valve 330 is on is introduced.

The lock-up clutch rapid release valve 400 is a two-position operation type spool valve, and includes a port 402a communicating with the clutch pressure oil passage 92 via a throttle 401, a port 402b communicating with a release-side oil passage 324, and a lock-up clutch. A port 402c communicating with the port 321b of the control valve 320, a port 402d communicating with the port 321f of the lock-up clutch control valve 320, a port 402e communicating with the engagement side oil passage 322, and a communication with the port 321d of the lock-up clutch control valve 320. Port 402f and the port 402b and port 40 during normal times (off side in the figure: third position).
2c, the port 402e communicates with the port 402f, and when the port is suddenly released (on side in the figure: fourth position), the port 402a and the port 402b
Spool valve element 406 that connects port 402d and port 402e
And a spring 408 for urging the spool valve element 406 toward the sudden release position. A signal pressure P _sol4 generated when the fourth solenoid valve 346 is in the ON state is guided to the chamber 410 on the lower end side of the spool valve element 406. As shown, the on-side and off-side positions of the third solenoid valve 330 and the lock-up clutch control valve 320
The on-side and off-side positions of the solenoid valve operatively correspond to each other, and the on-side and off-side positions of the fourth solenoid valve 346 and the on-side and off-side positions of the lock-up clutch sudden release valve 400 are activated. It is made to correspond.

Therefore, if the third solenoid valve 330 is turned on while the fourth solenoid valve 346 is off, the spool valve element 326 is turned off.
The lock-up clutch is positioned as shown on the side
Since the third oil passage for engaging the second oil passage 36 is formed, the hydraulic oil in the lock-up clutch pressure oil passage 92 is supplied to the port 321c, the port 321d, the port 402f, the port 402e, and the engagement-side oil passage.
Hydraulic oil supplied to the fluid coupling 12 through the fluid coupling 322 and flowing out of the fluid coupling 12 is supplied to the release-side oil passage 324, the port 402b, and the port 402.
c, drained from port 321a via port 321b.
As a result, the lock-up clutch 36 is engaged.

Conversely, when the fourth solenoid valve 346 is in the off state,
When the solenoid valve 330 is turned off, a 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 supplied to the port 321c,
The hydraulic oil supplied to the fluid coupling 12 through the port 321b, the port 402c, the port 402b, and the release-side oil passage 324 and flowing out of the fluid coupling 12 is supplied to the engagement-side oil passage 322, the port 402e, and the port 4
02f, port 321d, port 402e, and oil cooler 339
Is drained through. As a result, the first release mode is set and the lock-up clutch 36 is released.

In this embodiment, when the third solenoid valve 330 and the fourth solenoid valve 346 are turned on, the lock-up clutch 36
In this second release mode, the hydraulic oil in the lock-up clutch pressure oil passage 92 is supplied to the port 402a, the port 402b, and the release-side oil passage in the second release mode.
Hydraulic oil supplied to the fluid coupling 12 through 324 and flowing out of the fluid coupling 12 is supplied to the engagement-side oil passage 322, the port 402e, and the port 402.
D, through the port 321f, the port 402e, 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 fixed to the ON side or the spool valve element 4 of the lock-up clutch
When the lock-up clutch 36 is maintained in the engaged state even if one of the first release mode and the second release mode is selected for release for the purpose of release, By switching to the other mode, engine stall is prevented and the vehicle can be restarted. Further, the spool valve element 326 of the lock-up clutch control valve 320 is fixed to the off side, or the spool valve element 406 of the lock-up clutch rapid release valve 400 is fixed to the on side, and the first release is performed for the purpose of release. If the lock-up clutch 36 is maintained in the sudden release state even if one of the modes or the second release mode is selected, the operation oil is drained through the oil cooler 339 by switching to the other mode. Overheating of the oil can be suitably prevented.

When the lock-up clutch 36 is disengaged and abrupt release is required as in the case of sudden braking of the vehicle, the fourth solenoid valve 346 is turned off when the third solenoid valve 330 is turned off. Is turned on. As a result, a second oil passage for rapidly releasing the lock-up clutch 36 is formed, so that the hydraulic oil in the lock-up clutch pressure oil passage 92 is exclusively supplied from the port 402a to the port 402b and the release-side oil passage.
Hydraulic oil flowing into the fluid coupling 12 through 324 and flowing out of the fluid coupling 12 is provided with an engagement-side oil passage 322, a port 402e, a port 402d,
Drained from port 321g via port 321f. As a result, the oil is drained without passing through the oil cooler 339 having a large flow resistance, so that the lock-up clutch 36 is quickly released. FIG. 15 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
The hydraulic oil returned to the oil tank (not shown) is relieved by a cooler oil pressure control valve 338 provided on the upstream side of the oil cooler 339, so that the pressure is adjusted to a certain value or less. Also, bypass oil passage
334 guides a part of the hydraulic oil to the oil cooler 339 so that the hydraulic oil is cooled by the oil cooler 339 even while the lock-up clutch 36 is engaged. Aperture 336 and
Reference numeral 337 is for setting the ratio of hydraulic oil guided to the oil cooler 339 while the lock-up clutch 36 is engaged.

Next, back pressure control of the accumulator, line hydraulic pressure down control in the N range, line hydraulic pressure down control at high vehicle speed,
1st relay valve related to reverse inhibit control, etc.
The 380 and the second relay valve 440 will be described. The first relay valve 380 includes a port 382a communicating with the port 442c of the second relay valve 440, a port 382b to which the signal pressure P _sol5 is supplied, and a second
The port 382c communicating with the chamber 136 of the pressure regulating valve 102 and the reverse inhibit valve 420, and the drain port 382d, and the port 382a, the port 382b, and the port 38 in the ON state shown in the drawing.
2c communicates with the drain port 382d to drain the port 328a and communicate the port 382b with the port 382c in the off state shown in the figure, and urges the spool valve 384 toward the off state. Spring 3
86, when the signal pressure P _sol4 is not _applied to the chamber 388 provided on the non-spring side of the spool valve element 384, the spool valve element 384 is set to the position shown on the off side, and the signal pressure P _sol5 is set to the second pressure regulating valve. 102 chamber 136 and reverse inhibit valve 42
0 is supplied to the chamber 435, but when the signal pressure P _sol4 is applied to the chamber 388, the spool valve element 384 is set to the position shown on the ON side, and the signal pressure P _sol5 is supplied to the port 442c of the second relay valve 440. Is done. 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 is connected to the chamber 133 of the second pressure regulating valve 102 and the throttle 443.
Port 442b communicating with each other through the
And 442c, the port 442d and the drain port 442e communicating with the accumulator 372 and the fourth pressure regulating valve 170, and the port 442d is communicated with the drain port 442e in the ON state in the figure, and the port 442d and the drain in the OFF state in the figure. A spool 444 that shuts off between the port 442e and a spring 446 that urges the spool 444 toward the off-side state is provided in a chamber 448 provided on the non-spring side of the spool 444. When the signal pressure P _sol3 is not applied, the spool valve element 444 is set to the position shown on the off side, and when the signal pressure P _sol3 is _applied to the chamber 448, the spool valve element 444 is set to the position shown on the on side. This allows ports 442c and 44
The signal pressure P _sol5 supplied to the chamber 133 of the second pressure regulating valve 102 through 2b is _branched by the spool valve element 444 being switched from the on position to the off position, and the accumulator 372 and the chamber 177 of the fourth pressure regulating valve 170 are _separated . Is also supplied. In the figure, the on and off states shown for the second relay valve 440 correspond to the on and off states of the third solenoid valve 330.

Next, the back pressure control of the accumulators 342 and 340 provided in the forward clutch 72 and the reverse brake 70 will be described. When the fifth solenoid valve 392 is duty-driven, the signal pressure P _sol5 generated downstream of the throttle 394 becomes
As shown in FIG. 16, the oil pressure is changed corresponding to the duty ratio _Ds5 . That is, the throttle 394 and the fifth solenoid valve 392 function as signal pressure generating means for generating the signal pressure P _sol5 . As described above, the signal pressure P _sol5 changed according to the drive duty ratio D _s5 of the fifth solenoid valve 392 is such that the first relay valve 380 is turned on and the second relay valve 440 is turned off for back pressure control. When the state is set, the oil is supplied to the accumulator 372 and the fourth pressure regulating valve 170 via the oil passage 348.

Here, the back pressure control of the accumulators 340 and 342 is N →
This is performed to reduce a shift shock (engagement shock) at the time of the D shift or the N → R shift, and suppresses a rise in the hydraulic pressure in the hydraulic cylinder during a clutch engagement for a predetermined time to reduce the shock. Therefore, the fourth line hydraulic pressure Pl ₄ supplied to the back pressure port 366 of the accumulator 342 for the forward clutch 72 and the back pressure port 368 of the accumulator 340 for the reverse brake 70 is changed by the fourth pressure regulating valve 170, The mitigation action of the accumulators 342 and 340 is controlled.

In the fourth pressure regulating valve 170, the fourth line pressure Pl ₄ the signal pressure
The pressure is adjusted to the pressure corresponding to P _sol5 . That is, during the N → D shift and the N → R shift, the signal pressure P _sol5 is _increased through the first relay valve 380 and the second relay valve 440 to the fourth pressure regulating valve.
While being supplied to the chamber 177 of the 170, as shown in FIG. 17, the fourth line pressure Pl ₄ duty ratio of the fifth solenoid valve 392
Since the value is controlled to a value corresponding to _Ds5 , the fifth solenoid valve 392 is duty-driven so as to generate a back pressure suitable for reducing a shift shock (engagement shock). Further, since the oil pressure of the forward clutch 72 rises to the third line pressure Pl _3, signal pressure P _SOL5 being supplied to the fourth pressure regulating valve 170 is shut off by the second relay valve 440 chamber 17
When the inside of the cylinder 7 is released to the atmosphere, the fourth line hydraulic pressure Pl ₄ becomes relatively low at 4 kg corresponding to the urging force of the spring 172 in the valve opening direction.
It is controlled to a constant pressure of about / cm ² . The fourth line pressure Pl ₄ pressure regulated in this constant pressure exclusively shifting direction switching valve 2
Drive hydraulic pressure (pilot hydraulic pressure) for 62 and flow control valve 264
Used as Therefore, in the present embodiment, the fourth pressure regulating valve 170 includes the shift direction switching valve 262 and the flow control valve 264.
It functions as a valve drive oil pressure generating device for generating a valve drive oil pressure for driving the valve. The accumulator 372 provided in the oil passage 348 is for absorbing the pulsation of the signal pressure P _sol5 related to the duty drive frequency of the fifth solenoid valve 392.

Next, the relevant portion to the reduction control of the second line pressure Pl _2. In order to prevent the transmission belt 44 from being overloaded by the centrifugal oil pressure in the low pressure side hydraulic cylinder, the fourth solenoid valve 346 and the first relay valve 380 are turned off and the fifth solenoid valve is turned off in a high vehicle speed state. When the 392 is turned on, the second line mainly supplying the secondary hydraulic cylinder 56 when the output shaft 38 of the CVT 14 is rotating at high speed regardless of the operation state of the third solenoid valve 330 and the second relay valve 440. The hydraulic pressure Pl ₂ is reduced. That is, the first relay valve 3
Signal pressure P _sol5 (= P
When l ₄₎ is supplied to the chamber 136 of the second pressure regulating valve 102, pressurized second line pressure Pl ₂ is adjusted in accordance with the following equation (3), as shown in dashed line in FIG. 18, indicated by the solid line The pressure is set lower than the normal second line hydraulic pressure. Thus, the influence of the centrifugal oil pressure in the secondary hydraulic cylinder 56 is eliminated, and the durability of the transmission belt 44 is improved. Such a second line hydraulic
The control for lowering Pl ₂ is also executed when the reverse prohibition control described later or when the shift lever 252 is operated to the N range. When the fourth solenoid valve 346 is turned on or the fifth solenoid valve 392 is turned off, the second line oil pressure Pl ₂ is controlled as usual according to the above equation (1).

Pl ₂ = [A ₄ · P _th + (A ₅ -A ₄ ) · P _sol5 + W -A ₁ · P _e- (A ₂ -A ₁ ) · P _sol5 ] / (A ₃ -A ₂ ) (3) The reverse inhibit valve 420 provided to prohibit the reverse during forward running is a manual valve 2
When 50 is in the R range, its output port 256
Ports 422a and 422b to which the line hydraulic pressure Pl ₃ is supplied, a port 422c communicating with the hydraulic cylinder of the reverse brake 70 via the oil passage 423, and a drain port 422d, and a first position (not blocked) Position) and a spool valve 424 slidably disposed between a lower end and a second position (blocking position), and urges the spool valve 424 in the valve opening direction toward the first position. A spring 426 and a plunger 428 having a smaller diameter than the lower end of the spool valve element 424 are provided. A first land 430 having a small diameter, a second land 432 having a diameter larger than the first land 430, and a third land 434 having the same diameter as the first land 430 are formed from the upper end of the spool valve 424. The signal pressure is supplied to the chamber 435 provided on the side through the first relay valve 380 in the off state.
P _sol5 is supplied. First land 4 above
The chamber 436 between the second land 432 and the second land 432 and the chamber 437 between the second land 432 and the third land 434 have a manual valve 250 and a third line hydraulic pressure Pl ₃ only when operated in the R range.
The spool valve element is
In the room 438 between the 424 and the plunger 428, there is a reverse brake 7
The third line pressure Pl ₃ is a chamber 439 provided on the end surface of the plunger 428 is constantly supplied with oil pressure in the 0 is acted. The pressure receiving area of the plunger 428 where the third line oil pressure Pl ₃ acts is substantially equal to the pressure receiving area difference between the first land 430 and the second land 432 of the spool valve 424 receiving the oil pressure in the chamber 436. ing.

The reverse inhibit valve 42 thus configured
0, the biasing force of the spring 426, hydraulic and third line pressure Pl and the signal pressure P _SOL5 than the valve-opening direction thrust based on ₃ third line pressure Pl _3-closing direction of the thrust based on in reverse brake 70 Rises, the spool 424 is moved against the urging force of the spring 426 to shut off the connection between the ports 422b and 422c, and the port 422c and the drain port
Since the communication with 422d is established, the reverse brake 70 is released to the drain, and the establishment of the reverse gear of the forward / reverse switching device 16 is prevented. That is, when the fourth solenoid valve 346 is in the off state, the fifth solenoid valve 392 is turned on and the signal pressure P
_{When sol5} is generated, establishment of the reverse gear of the forward / reverse switching device 16 is prevented on condition that the shift lever 252 is operated to the R range. However, the reverse inhibit valve 420 requires that the fourth solenoid valve 346 be turned on, the fifth solenoid valve 392 be turned off, and the shift lever 252 be operated to a range other than the R range. Is performed, the spool valve element 444 is moved in accordance with the biasing force of the spring 426, and the reverse brake 70 is communicated with the port 256 of the manual valve 250. Therefore, when the fourth electromagnetic valve 346 is turned off and the fifth electromagnetic valve 392 is turned on by the electronic control unit 460 described later, the shift lever 252 is erroneously operated from the D range to the N range through the N range. In this case, the engagement of the reverse brake 70 is prevented, and the forward / reverse switching device 16 is maintained in the neutral state.

The first relay valve 380 is in the off state, that is, the fourth solenoid valve 346
Is in the off state, the signal pressure P _sol5 is supplied to the chamber 136 of the second pressure regulating valve 102 through the first relay valve 380, so that the second line oil pressure Pl ₂ is reduced by a predetermined pressure according to the signal pressure P _sol5. Can be As a result, in the N range, the transmission belt
The clamping pressure on 44 is made as low as possible without causing slippage, so that the noise level of the belt is reduced and the durability of the transmission belt 44 is enhanced.

Further, the first relay valve 380, that is, the fourth solenoid valve 346 is in the ON state, and the second relay valve 440, that is, the third solenoid valve 380, is turned on.
There when it is turned on, the signal pressure P _SOL5 is supplied through the first relay valve 380 and second relay valve 440 to chamber 133 of the second pressure regulating valve 102, the second line pressure Pl ₂ is the signal pressure P
_The predetermined pressure is increased according to _sol5 . Thus, at the time of sudden deceleration shifting such as during sudden braking, etc., at the time of sudden deceleration shifting by operating the shift lever 252 from the D range to the L range, the shift lever 25
In the accumulator back pressure control time by the operation of the second N range to the D or R range, the second line pressure Pl ₂ is increased. Therefore, in a state where the transmission belt 44 of the CVT 14 may slip as described above,
The tension of the transmission belt 44 (the clamping force on the transmission belt 44) is temporarily increased, and the torque transmission capacity is increased.

FIG. 19 shows a combination of operations of the above-described third solenoid valve 330, fourth solenoid valve 346, and fifth solenoid valve 392, and an operation mode obtained thereby.

2, the electronic control unit 460 includes a first solenoid valve 266, a second solenoid valve 268, and a third solenoid valve 266 in the hydraulic control circuit of FIG.
By selectively driving the solenoid valve 330, the fourth solenoid valve 346, and the fifth solenoid valve 392, the speed ratio e of the CVT 14, the engagement state of the lock-up clutch 36 of the fluid coupling 12, the second line hydraulic pressure Pl
_2. Control the ascending or descending control of ₂ . The electronic control unit 460 includes a so-called microcomputer including a CPU, a RAM, a ROM, and the like. The microcomputer includes a vehicle speed sensor 462 that detects the rotational speed of the drive wheels 24, the input shaft 30 of the CVT 14, and the output shaft.
Input shaft rotation sensor 464 that detects 38 rotation speeds respectively
And an output shaft rotation sensor 466, a throttle valve opening sensor 468 for detecting an opening of a throttle valve provided in an intake pipe of the engine 10, an operation position sensor 470 for detecting an operation position of the shift lever 252, and a brake pedal. a brake switch 472 for detecting an operation, the engine speed sensor 474 for detecting the rotational speed N _e of the engine 10,
Signal representing the vehicle speed V, the signal representing the input shaft rotational speed N _in, the signal representing the output shaft speed N _out, the signal representing the throttle valve opening theta _th, signals representing the operating position P _s of Shifurereba 252,
Signal representing the brake operation, a signal is supplied which represents the engine rotational speed N _e. The CPU in the electronic control unit 460 is RA
The input signal is processed according to a program stored in the ROM while utilizing the temporary storage function of M, and the first solenoid valve 26 is processed.
6, the second solenoid valve 268, the third solenoid valve 330, the third solenoid valve 346, the fifth
A signal for driving the solenoid valve 392 is output.

In the electronic control unit 460, initialization is executed when the power is turned on, and thereafter, a main routine (not shown) is executed, so that input signals and the like from each sensor are read, and input is performed based on the read signals. axis
The rotation speed N _{in of} 30, the rotation speed N _out of the output shaft 38, the speed ratio e of the CVT 14, the vehicle speed V, etc. are calculated, and the lock-up clutch engagement control and the quick release control of the lock-up clutch 36 are controlled according to the input signal condition. , CVT 14 shift control, accumulator back pressure control, reverse prohibition control, second line pressure decrease control, second line pressure increase control, and the like are sequentially or selectively executed.

In the shift control of the CVT 14, the control is performed, for example, according to a flowchart shown in FIG. In step S1, input signals and the like from each sensor are read, and based on the read signals, the vehicle speed V and the input shaft
30 rotation speed N _in , output shaft 38 rotation speed N _out , throttle valve opening θ _th , shift operation position P _s , engine rotation speed _Ne
Is calculated. In step S2, the input shaft 30 is determined based on the shift operation position P _s , throttle valve opening θ _th , and vehicle speed V from the relationship [N _in ^* = f (θ _th , V, P _s )] obtained in advance. the target rotational speed N _in ^* is determined of. This relationship is, for example, D, in order to generate the required output represented by the throttle valve opening degree θ _th on the minimum fuel consumption rate curve of the engine 10,
A plurality of sets are determined in advance for each of the S and L ranges, and are previously stored in the ROM in the form of a function expression or a data map. When the shift operation position is in the S or L range, it is a state where more sporty traveling or enhanced engine braking action is required, so that the relationship selected in the S or L range is higher than that in the D range. Target rotation speed so that
N _in ^* is set higher. The shift operation position for traveling is not limited to the three positions of the D, S, and L ranges, and can be arbitrarily set as needed.

In the following step S3, the control deviation ΔN between the actual rotation speed N _in of the input shaft 30 of the CVT 14 and the target rotation speed N _in ^*
_in (= N _in ^* −N _in ) is determined. Then, step S4
Then, one of the plurality of types of shift modes shown in FIG. 10 is selected based on the magnitude of the control deviation ΔN _in obtained in step S3. This selection method is, for example, the tenth
A shift mode corresponding to a region including the control deviation ΔN _in is selected from the hatched regions corresponding to the plurality of types of shift modes shown in the drawing. Of the multiple types of shaded areas in FIG. 10,
An overlap portion is provided between adjacent regions to prevent the control from becoming unstable due to the repeated shift modes being alternately repeated. If the control deviation .DELTA.N _in takes a value within the overlapping section is shifted state close to the current shift mode is selected. For example, when the initial control deviation ΔN _in is 250 rpm and the shift mode (B) is selected, the control deviation ΔN _in
If N _in falls to 140 rpm and is included in the overlap between the shift mode (b) and the shift mode (c), the shift mode (b) is selected. When the control deviation ΔN _in is included in the overlap between the shift mode (b) and the shift mode (c) from the state where the shift mode (c) is selected, the shift mode (c) is selected. It is done.

Then, it is determined in step S5 whether or not the shift mode (b) has been selected, and in step S6, it is determined whether or not the shift mode (e) has been selected.
If the shift mode (b) is selected in step S4, the determination in step S5 is affirmative, so that the duty ratio D of the second solenoid valve 268 is determined in step S7.
_s2 (%) is calculated according to the following equation (4). Step S4
In the case where the shift mode (e) is selected in step S6, the determination in step S6 is affirmed, and the duty ratio _s2 of the second solenoid valve 268 is calculated in step S8 according to the following equation (5).

D _s2 = K ₁ · ΔN _in (4) D _s2 = −K ₂ · ΔN _in (5) where K ₁ and K ₂ are constants.

Here, in determining the duty ratio D _s2 of the second solenoid valve 268, the two types of equations (4) and (5) are used because the flow characteristics of the flow control valve 264 are different in the deceleration direction and the speed increase direction. Because they are different.

The first solenoid valve 266 and the second solenoid valve 268 are driven in a later-described step S12 in the duty ratio _Ds2 determined as described above or in the on or off state determined in the step S4, respectively. Second solenoid valve 26
The duty drive of 8 is performed, for example, for a certain time (period) T _D
Of, T _D · _{D s2} / 100 hours is turned on, T _D · _(1-D
(s2 / 100) is executed periodically so that the time is turned off. Here, the (4) duty ratio D _s2 determined by and Equation (5) are those in proportion to the magnitude of the control deviation .DELTA.N _in increasing the flow rate, control deviation .DELTA.N _in the eliminated by this the flow rate in a direction which is is controlled by driving the flow control valve 264 is performed (step S12) by the duty ratio D _s2 determined in step S7 or S8, the actual and target rotational speed N _in ^* Feedback control for matching the rotation speed N _in is executed.

In step S9, the third solenoid valve 330 and the fourth solenoid valve 346
, Ie, lock-up clutch engagement / release control, lock-up clutch rapid release control, accumulator back pressure control, reverse prohibition control, second control
A control mode determination routine for determining which control mode of the line hydraulic pressure reduction control is to be executed is executed. Although the control mode determination routine is not shown, the control mode is determined according to whether a predetermined condition is satisfied.

For example, when the shift lever 252 is operated to the N range, the third solenoid valve 33 is set to be in the B mode in FIG.
0 and the fourth solenoid valve 346 are determined to be in the off state,
The solenoid valve 392 is determined to be in the ON state. As a result, the second line hydraulic pressure Pl ₂ is reduced by a predetermined value in order to prevent noise of the transmission belt 44 in the N range and increase durability. If it is determined that the vehicle is traveling forward at a vehicle speed V equal to or higher than a predetermined value of, for example, about 7 to 10 km / h, the third solenoid valve 330, the fourth solenoid valve 346, the fifth
The same state as the operation of the solenoid valve 392 is maintained. For this reason,
Since the signal pressure P _sol5 continues to be supplied to the chamber 435 of the reverse inhibit valve 420, if the shift lever 252 is erroneously operated to the R range, the third line is transferred from the port 256 of the manual valve 250 to the chamber 436 of the reverse inhibit valve 420. Hydraulic Pl
₃ is supplied, the reverse inhibit valve 420 is operated to the stop position, and the establishment of the reverse gear is prevented.

When the throttle opening θ and the vehicle speed V of the vehicle are well known and stored in advance and enter an engagement area of a lock-up clutch engagement diagram (not shown), the engagement mode of FIG. The third solenoid valve 330 is set to be in the mode.
And the off state of the fourth solenoid valve 346 is determined.
The lock-up clutch 36 is engaged. In this state, the vehicle speed V is a predetermined constant value, for example, 100 km /
h, the ON state of the fifth solenoid valve 392 is determined and the
In addition to the ON state of the third solenoid valve 330 and the OFF state of the fourth solenoid valve 346, the fifth solenoid valve is determined to be in the ON state so as to be in the D mode of FIG. As a result, the second line oil pressure Pl ₂ is reduced by a predetermined value in order to prevent the transmission belt 44 from becoming excessively tensioned by the centrifugal oil pressure.

In the engaged state of the lock-up clutch 36, when the vehicle speed V and the throttle opening θ in the D range are out of the engagement region of the above-mentioned diagram or when the vehicle is operated to the N range, FIG. Both the third solenoid valve 330 and the fourth solenoid valve 346 are determined to be in the on state or the off state so as to be in the first release mode or the second release mode, that is, the A or H mode in FIG. As a result, the lock-up clutch 36 is released. The H mode is selected when the transmission capacity of the CVT 14 is required more than usual, such as when the vehicle starts or when the vehicle shifts from D to L. As a result, the second line oil pressure Pl ₂ is increased by a predetermined value, and the clamping force of the transmission belt 44 is increased.

If the control is neither reverse prohibition control nor N or P range, the rotational speed of the input shaft (output shaft 38) and the output shaft 58 in the forward / reverse switching device 16 in the R range according to the following equation (6). The difference Nd is calculated from the following equation (6), and D,
In the forward range such as the S and L ranges, the following equation (7) is used.
The rotation speed difference Nd is calculated according to

_{Nd = | N out -i p ·} N pc | ··· (6) Nd = | N out -N pc | ··· (7) , where the N _out is the rotational speed of the output shaft 38 of the CVT 14, N _pc
Rotational speed of the carrier 60 of the forward-reverse switching device 16, the i _p is the gear ratio before the time of reverse-reverse switching device 16. The N _pc has a completely one-to-one correspondence with the vehicle speed V, and is obtained according to the following equation (8). Further, the i _p is obtained from N _out and N _pc when the reverse brake 70 is completely engaged state in accordance with the following equation (9).

_{N pc = C / V ··· (} 8) i p = N out / N pc ··· (9) where, C is a constant.

The rotation speed difference Nd obtained as described above is
Greater or not than the criterion value C _N of the stored, for example, about 30rpm is judged to M. The criterion value C _N is a value for determining whether the engagement of the forward clutch 72 or reverse brake 70 has been completed. If it is determined that the actual rotation speed difference Nd is not larger than the criterion value C _N , the back pressure control is not performed because the engagement is completed, but the actual rotation speed difference Nd is equal to the criterion value C _N. If it is determined that the third solenoid valve 330 is larger than the third solenoid valve 330, the fourth solenoid valve 346 is turned off.
, The ON state of the fifth solenoid valve 392 or the duty driving state is determined, and the accumulator back pressure control mode shown in FIG. 19F is selected. At this time, the fifth solenoid valve 392
Is changed according to a time function stored in advance. Thereby, N → D shift operation or N
→ Accumulator 342 or 340 during R shift operation
Is gradually changed, and the forward clutch 72 or the reverse brake 70 is smoothly engaged.

In the forward range, when the brake switch 472 is in the ON state and the release condition of the lock-up clutch 36 that the vehicle speed V is lower than a previously stored reference value is satisfied, the lock-up clutch sudden release control mode (E ) Is selected once, and then the lock-up clutch release control mode (G) is selected. That is, the lock-up clutch rapid release control mode (E) is selected by determining the off state of the third solenoid valve 330, the on state of the fourth solenoid valve 346, and the off state of the fifth solenoid valve 392. After a predetermined time elapses, the third solenoid valve 33
When only 0 is switched to the ON state, the lock-up clutch release control mode (G) is selected.

Further, in the step relating to the fail-safe, an abnormality (failure) of the lock-up clutch control valve 320 and the lock-up clutch rapid release valve 400 is detected, and the first release mode of FIG. Alternatively, one of the second release modes is selected. For example, even when the vehicle speed V or the throttle opening _θth is out of the engagement area of the lock-up clutch 36 in the engagement diagram and is in one of the first release mode and the second release mode, the fluid coupling When it is determined that the lock-up clutch 36 is engaged based on a rotation difference (= N _e −N _in ) of the 12 input / output shafts being smaller than a predetermined determination reference value, for example, a value of 30 rpm, If it is determined that the lock-up clutch 36 is engaged based on the engine stall, the other release mode is selected. Also, the vehicle speed V or the throttle opening θ _th
Is in the engagement area of the lock-up clutch 36 in the engagement diagram, and the third solenoid valve 33 is set so as to be in the engagement mode in FIG.
Even when 0 is in the ON state and the fourth solenoid valve 346 is in the OFF state, the rotation difference between the input and output shafts of the fluid coupling 12 (= N _e −N _in )
Is larger than the predetermined reference value, the lock-up clutch control valve 320 is actually turned off and the lock-up clutch sudden release valve 400 is turned on. Since it is in the state and is in the sudden release mode, the cooling of the hydraulic oil is ensured by selecting the other release mode.

As described above, after the control mode is selected in step S9, it is determined in step S10 whether or not the control mode is the back pressure control mode shown in FIG. 19F. If it is in the back pressure control mode, the duty ratio _Ds5 of the fifth solenoid valve 392 is determined in step S11, but if it is not in the back pressure control mode, step S12 is directly executed. In step S12, the first solenoid valve 266, the second solenoid valve 268, and the third solenoid valve 33 corresponding to each control mode determined in steps S4 and S9.
A drive signal is output so that the ON state or the OFF state of 0, the fourth solenoid valve 346, and the fifth solenoid valve 392 can be obtained.

As described above, according to the present embodiment, the reverse inhibit valve 420 is set to the stop position when the signal pressure P _sol5 is supplied to the chamber 435 and the third line oil pressure Pl ₃ from the manual valve 250 is supplied to the chamber 436. The signal pressure P _sol5 is also used for another purpose, that is, for lowering the second line pressure Pl ₂ . Therefore, since a plurality of types of control can be performed using the common signal pressure generating means including the fifth solenoid valve 392, the hydraulic control can be performed in comparison with the case where the signal pressure generating means is prepared for each control. The circuit becomes simple.

Further, even if the signal pressure P _sol5 is supplied to the chamber 435 of the reverse inhibit valve 420 even when an abnormality occurs in the fifth solenoid valve 392 and the shift lever 252 is not operated to the R range, the manual valve 250 The hydraulic pressure for establishing the reverse gear from the port 256, that is, the third line hydraulic pressure Pl ₃
There is an advantage that the reverse inhibit valve 420 cannot be switched to the blocking position unless is output.

As described above, one embodiment of the present invention has been described with reference to the drawings. However, the present invention can be variously modified without departing from the spirit thereof.

For example, in the above-described embodiment, the reverse gear is prevented from being established when the signal pressure P _sol4 and the signal pressure P _sol5 are in the off state and the on state. However, in other on / off states. Is also good. In short, the combination of generation state of the signal pressure P _SOL4 and the signal pressure P _SOL5 to prevent the establishment of the reverse gear, the reverse inhibit valve 420 by at least one state is different is a non-blocking position What is necessary is just to be comprised so that.

In the above-described embodiment, the lock-up clutch 36 provided in the fluid coupling 12 has been described. However, another type of hydraulically operated clutch may be used.

In the above-described embodiment, two types of the first line hydraulic pressure Pl ₁ and the second line hydraulic pressure Pl ₂ are used to act on the primary hydraulic cylinder 54 and the secondary hydraulic cylinder 56. The hydraulic pressure output from a single hydraulic source is constantly applied to the secondary hydraulic cylinder to control the tension of the transmission belt, while the hydraulic oil from that hydraulic source flows into the primary hydraulic cylinder or the primary hydraulic cylinder The hydraulic control device may be of a type in which the speed ratio is changed by a shift control valve device that causes the hydraulic oil inside to flow out.

In the above-described embodiment, the belt-type CVT 14 has been described. However, the present invention can be applied to a traction-type continuously variable transmission in which power is transmitted via rollers.

In the above-described embodiment, the throttle valve opening detection valve 18
Although the throttle pressure P _th generated by 0 is used, in a vehicle that does not use a throttle valve, such as a vehicle equipped with a diesel engine, a hydraulic pressure corresponding to the accelerator pedal operation amount may be used. In such a case, for example, the cam 184 of the above-described embodiment may be mechanically associated with the accelerator pedal so as to rotate as the accelerator pedal is depressed.

In the shift control of the CVT 14 in the above-described embodiment,
While the target rotation speed N _in ^* the actual input shaft speed N _in was controlled so as to coincide, from the speed ratio e = N _out / N _in, the actual speed ratio e to the target speed ratio e ^* is This is substantially the same even if the speed ratio e is controlled to match.

In the above-described embodiment, the forward / reverse switching device 16 is provided between the output shaft 38 of the CVT 14 and the intermediate gear device 18, but the forward / reverse switching device 16 is provided between the fluid coupling 12 and the input shaft 30 of the CVT 14. The device 16 may be provided. The forward / reverse switching device 16 may have two or more forward gears.

Further, instead of the fluid coupling 12 of the above-described embodiment, another type of coupling such as a torque converter, an electromagnetic clutch, and a wet clutch may be used.

The above is merely an example of the present invention, and the present invention can be variously modified without departing from the spirit thereof.

[Brief description of the drawings]

FIG. 1 is a circuit diagram showing in detail a hydraulic control device for operating the device of FIG. FIG. 2 is a skeleton view showing a vehicle power transmission device provided with a hydraulic control device according to one embodiment of the present invention. FIG. 3 is a diagram showing the second pressure regulating valve of FIG. 1 in detail. FIG. 4 is a diagram showing the first pressure regulating valve of FIG. 1 in detail. FIG. 5 is a view showing output characteristics of the throttle valve opening detection valve of FIG. FIG. 6 is a diagram showing output characteristics of the speed ratio detection valve of FIG. FIG. 7 is a diagram showing output characteristics of the second pressure regulating valve of FIG. FIG. 8 is a diagram showing ideal characteristics of the second line hydraulic pressure. FIG. 9 is a diagram showing the configuration of the transmission control valve device of FIG. 1 in detail. FIG. 10 shows the ninth
FIG. 3 is a diagram for explaining a relationship between operating states of a first solenoid valve and a second solenoid valve in the shift control valve device of FIG. 2 and shift states of the CVT of FIG. 2; FIG. 11, FIG. 12, and FIG.
FIG. 11 is a diagram for explaining the relationship between the speed ratio of the CVT and the oil pressure value of each part, wherein FIG. 11 shows a positive torque running state, FIG. 12 shows an engine brake running state, and FIG. 13 shows a no-load running state, respectively. It is. FIG. 14 is a diagram showing output characteristics of the first pressure regulating valve of FIG. 4 with respect to the hydraulic pressure in the primary hydraulic cylinder or the second line hydraulic pressure. FIG. 15 is a chart showing the relationship between the combination of the operating states of the third and fourth solenoid valves of FIG. 1 and the operating state of the lock-up clutch. No.
FIG. 16 is a diagram showing the relationship between the drive duty ratio D _s5 of the fifth solenoid valve of FIG. 1 and the signal pressure P _sol5 obtained thereby. 17 is a graph showing a change characteristic of the fourth line pressure Pl ₄ for it continuously changed in relation to the duty ratio D _s5 fifth solenoid valve in the hydraulic circuit of Figure 1.
FIG. 18 is a diagram illustrating a second line hydraulic pressure that changes in relation to the vehicle speed (centrifugal hydraulic pressure). FIG. 19 is a chart showing a relationship between a combination of operation of the third solenoid valve, the fourth solenoid valve, and the fifth solenoid valve in the control device of FIG. 2 and a control mode selected thereby. FIG. 20 is a flowchart illustrating the operation of the control device of FIG. 16: Forward / backward switching device (automatic transmission) 70: Reverse brake (reverse hydraulic actuator) 250: Manual valve (switching valve) 252: Shift lever (shift operating member) 392: Fifth solenoid valve (signal pressure generating means 394: Throttle (signal pressure generation means) 420: Reverse inhibit valve (backward stop valve)

Continuation of front page (72) Inventor Ryoji Habuchi 1 Toyota Town, Toyota City, Aichi Prefecture Inside Toyota Motor Corporation (56) References JP-A-63-13949 (JP, A)

Claims (1)

(57) [Claims] An automatic transmission for a vehicle in which the power of an engine is transmitted to drive wheels via a gear device automatically switched to a reverse gear position, in relation to an operation of a shift operation member to a reverse operation position. A hydraulic control device for supplying hydraulic pressure for establishing the reverse gear to a reverse hydraulic actuator, wherein the hydraulic control device is switched in relation to an operation of the shift operation member, and the shift operation member is operated to a reverse operation position. A switching valve for outputting a hydraulic pressure for establishing the reverse gear when the reverse gear is operated, and a solenoid valve operated by an electric signal, and a signal pressure for preventing the establishment of the reverse gear during forward running according to the electric signal. And a signal pressure generating means for generating the signal pressure and the reverse gear inserted in an oil passage through which hydraulic pressure is supplied to the reverse hydraulic actuator. When the hydraulic pressure is supplied at the same time, the position is switched to a blocking position for preventing the reverse gear from being established. And a reverse blocking valve positioned at a non-blocking position.