JPH05133466A - Hydraulic controller of continuously variable transmission for vehicle - Google Patents

Abstract

PURPOSE:To make a backward movement performable even in the case of valve rod seizing or binding by forming a high speed step frictional engager into an engaging state with a signal out of an electromagnetic signal pressure generator valve and a low speed step frictional engager into a releasing state irrespective of the position of a low speed step control valve rod, respectively, in the case where a shift lever is in a backward range. CONSTITUTION:When a shift lever is operated to an R range, a high speed step clutch cares to an engaging state in response to the actuation of a sixth solenoid valve 162 when a valve rod 420 of a C2 control valve 410 is situated in an engaging position. On the other hand, a low speed step brake comes to a releasing state irrespective of the position of a valve rod 442 of a B2 control valve 412 as forward range pressure is not generated there. In consequence, even in the case where the B2 control valve 412 is made impossible to be selected to a release position of the low speed step brake, any lock to a sub transmission is prevented from occurring. Furthermore, since only a high speed step clutch comes to the engaging state, backward traveling can be done as required by a driver.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hydraulic control system for a continuously variable transmission for a vehicle which includes a forward / reverse switching device and an auxiliary transmission.

[0002]

2. Description of the Related Art A continuously variable transmission for a vehicle is provided with an auxiliary transmission having a plurality of types of forward gear stages for expanding a shift range, as disclosed in Japanese Patent Laid-Open No. 61-2958. Have been proposed. Further, Japanese Patent Application No. 3-74469 proposes that the forward-reverse switching device and the auxiliary transmission are separately arranged in order to further reduce the size of the one-way clutch. According to the continuously variable transmission for a vehicle of this type, the forward / reverse movement in which the rotation direction is switched by the hydraulic forward friction engagement device and the hydraulic backward friction engagement device that operate in association with the operating range of the shift lever is performed. From the switching device, the low speed gear stage established by the engagement of the hydraulic low speed friction engagement device and the one-way clutch, the engagement of the hydraulic high speed friction engagement device and the hydraulic low speed friction engagement The auxiliary gearbox, which is switched to a high-speed gear stage established by releasing the coupling device or the one-way clutch, is independently provided. When the shift lever is operated to the reverse range, the hydraulic control device for such a continuously variable transmission is unidirectional even if the low speed friction engagement device is engaged in the auxiliary transmission. Since the power is not transmitted due to the slipping of the clutch, only the hydraulic high-speed stage frictional engagement device is brought into the engaged state.

By the way, in the hydraulic control device provided in such a continuously variable transmission, two control valves, that is, a high speed control valve and a low speed control valve, are independently provided, so that the friction engagement for the high speed is performed. It is desired to improve the controllability of the sub-transmission by making it possible to engage or disengage either the device or the low-speed stage frictional engagement device without requiring complicated timing control. That is, for example, by engaging and disengaging the one-way clutch to engage the high speed gear friction engagement device while the low speed gear friction engagement device remains engaged, the high speed gear stage is smoothly established. .. Further, for example, a squat control is performed in which the low speed gear friction engagement device is released and the high speed gear friction engagement device is engaged for a predetermined period after the shift lever is operated from the neutral range to the forward range. As a result, the drive wheel torque is reduced, but when the predetermined period is completed and the low speed gear stage is established, the low speed stage friction engagement device remains engaged while the high speed stage friction engagement device remains engaged. By engaging and then releasing the high speed friction engagement device, the low speed gear is smoothly established by the action of the one-way clutch.

[0004]

However, the respective valve elements of the low speed friction engagement device control valve and the high speed control valve are
In the case where the engagement control of each friction engagement device is performed by switching between a position that allows the application of the engagement hydraulic pressure generated regardless of the operation of the shift lever and a position that prohibits the operation thereof, When the shift lever is operated to the reverse range and the valve element of the low speed control valve is stuck, it becomes impossible to switch the valve to the side for releasing the low speed friction engagement device. Has
Regardless of the signal pressure of the electromagnetic signal pressure generation valve, the engagement hydraulic pressure remains applied to the low speed friction engagement device, and it becomes impossible to switch the low speed friction engagement device to the released state. Become. Therefore, both the low-speed gear friction engagement device and the high-speed gear friction engagement device are brought into the engaged state, so that the auxiliary transmission is locked and the vehicle cannot reverse.

The present invention has been made in view of the above circumstances, and it is an object of the present invention to fix the valve element of the low speed control valve to the side on which the low speed friction engagement device is engaged. Even in such a case, it is an object of the present invention to provide a hydraulic control device that prevents the auxiliary transmission from being locked and enables reverse travel.

[0006]

To achieve the above object, the gist of the present invention is to provide a hydraulic forward friction engagement device and a hydraulic forward friction engagement device that operate in association with the operating range of a shift lever. From the forward / reverse switching device whose rotation direction is switched by the reverse friction engagement device, the low speed gear stage established by the engagement of the hydraulic low speed stage friction engagement device and the one-way clutch in series therewith, the hydraulic high speed stage is established. Continuously variable transmission in which an auxiliary transmission that is switched to a high-speed gear that is established by engagement of the frictional engagement device for the vehicle and its hydraulic low-speed frictional engagement device or release of the one-way clutch is provided independently In the machine, when the shift lever is operated to the reverse range, a hydraulic control device of the type that brings the hydraulic high speed gear friction engagement device into an engaged state, comprising: (a) an electronic control device An electromagnetic signal pressure generation valve that generates a signal pressure in response to a switching command signal from (b), and based on the signal pressure, the engagement hydraulic pressure generated regardless of the operation of the shift lever. The hydraulic high-speed frictional engagement device is provided with a valve element that can be switched between two positions, a position for acting on the hydraulic high-speed stage frictional engagement device and a position for inhibiting the operation. A control valve for a high speed stage for controlling the engagement state of, and (c) a forward range pressure generated by operating the shift lever to a forward range based on the signal pressure is used for the hydraulic low speed stage. The friction engagement device is provided with a valve that can be switched between two positions, a position where the action is applied and a position where the action is prohibited, and the engagement state of the hydraulic low-speed friction engagement device is controlled by switching the valve. Control valve for low speed Located in.

[0007]

In this way, when the shift lever is operated to the reverse range and the vehicle is required to travel backward, the friction engagement device for the high speed stage operates as the electromagnetic signal pressure generating valve. The frictional engagement device for the low speed stage is not engaged with the valve position of the low speed stage control valve because the forward range pressure is not generated while the high speed stage control valve is operated by the operation of the high speed stage control valve based on the signal pressure from Instead, it is released. Therefore, even if the valve element of the control valve for the low speed stage cannot be switched to the side for releasing the friction engagement device for the low speed stage due to the sticking of the valve element, the lock of the auxiliary transmission is prevented. .. Moreover, since only the high-speed-stage frictional engagement device is engaged, it is possible to travel backward in response to the driver's operating position as requested by the driver, without being unable to travel backward due to slippage of the one-way clutch. It becomes.

[0008]

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

FIG. 1 is a skeleton view of an FF vehicle transverse transaxle to which a control device according to an embodiment of the present invention is applied, and FIG. 2 is a block diagram showing a configuration example of the control device. In FIG. 1, the power of the engine 10 includes a fluid coupling 12 with a lock-up clutch, a forward / reverse switching device 14, and a belt type continuously variable transmission (hereinafter, referred to as CVT).
It is adapted to be transmitted to wheels 26 connected to a drive shaft 24 via 16, the auxiliary transmission 18, the reduction gear device 20, and the differential gear device 22.

The fluid coupling 12 is the engine 1
Pump impeller 30 connected to zero crankshaft 28
A turbine impeller 32 that is rotated by oil from the pump impeller 30; an output shaft 34 that is connected to the turbine impeller 32 such that it cannot rotate relative to the turbine impeller 32; and a damper 36 that is provided on the output shaft 34. A lock-up clutch 38 is provided. The pump impeller 30 includes a hydraulic pump 40.
Are connected to generate hydraulic pressure for operating the hydraulic actuators of the respective parts. In the fluid coupling 12, when the hydraulic oil is supplied to the disengagement side oil chamber 46 and the hydraulic oil in the engagement side oil chamber 48 is discharged, the lockup clutch 38 is released, and conversely, the engagement side oil chamber is released. When the hydraulic oil is supplied to the chamber 48 and the hydraulic oil in the release side oil chamber 46 is discharged, the lockup clutch 3
8 is engaged, and the crank shaft 28 and the output shaft 34 are directly connected.

The forward / reverse switching device 14 is a double pinion type planetary gear device which is selectively switched between a forward gear stage and a reverse gear stage in accordance with an operating position of a shift lever 142, which will be described later. It is arranged on the opposite side of the coupling 12. The output shaft 34 of the fluid coupling 12 extends through the shaft center of the input shaft 58 of the CVT 16 to the opposite side, and the planetary gear device has a sun gear 50 provided on the output shaft 34 so as not to rotate relative to the sun gear 50. 50, a pair of planet gears 54 and 56 that mesh with one and the other of the sun gear 50 and the ring gear 52 and mesh with each other, and rotatably support the planet gears 54 and 56. The CVT 16 also includes a carrier 60 that is connected to the input shaft 58 of the CVT 16 such that the carrier 60 cannot rotate relative to the input shaft 58. A multi-plate type forward clutch C1 is provided between the sun gear 50 and the carrier 60, and a multi-plate type reverse brake B1 is provided between the ring gear 52 and the housing 64. Engagement control is performed by the forward hydraulic actuator 42 and the reverse hydraulic actuator 44, respectively. When the forward clutch C1 is engaged in the state where the reverse brake B1 is released, the output shaft 34 and the carrier 60 are relatively non-rotatably connected and the input shaft 58 is rotated integrally with the output shaft 34 to move forward. When the clutch C1 is released and the reverse brake B1 is engaged, the rotation of the ring gear 52 is blocked and the carrier 6
0 Further, the gear ratio γ _FR (= rotational speed of the output shaft 34 / rotational speed of the input shaft 58) in the direction in which the input shaft 58 is opposite to the output shaft 34, that is, the direction in which the vehicle is moved backward = -1 + (number of teeth of the ring gear 52) Z _R / the number of teeth Z _{S of the} sun gear 50) causes decelerated rotation.

The CVT 16 includes the input shaft 58 and an output shaft 70 parallel to the input shaft 58.
8. The output shaft 70 is provided with a drive-side variable pulley 72 and a driven-side variable pulley 74, and a transmission belt 76 is wound between the variable pulleys 72 and 74. The variable pulleys 72 and 74 have the input shaft 5
8 and the fixed rotating body 7 fixed to the output shaft 70, respectively.
8 and 80, and movable rotating bodies 82 and 84 provided on the input shaft 58 and the output shaft 70 so as to be movable in the axial direction and not rotatable relative to each other about the axes, respectively. By being moved in the axial direction by the hydraulic actuators 86 and 88 arranged on the back side, the V groove width, that is, the hanging diameter (effective diameter) of the transmission belt 76 is changed, and the CVT 16
The gear ratio γ _CVT (= rotational speed N _in of the input shaft 58 / rotational speed N _out of the output shaft 70) is changed.

The sub-transmission 18 is composed of a single pinion type planetary gear device, and is connected to the output shaft 70 in a relatively non-rotatable manner with a sun gear 90 rotatably arranged concentrically with the output shaft 70. A ring gear 92, a sun gear 90 and a planet gear 94 meshed with the ring gear 92, and a carrier 98 rotatably supporting the planet gear 94 and non-rotatably connected to the second output shaft 96. I have it. A multi-plate high speed stage clutch C2 is provided between the sun gear 90 and the carrier 98, and a one-way clutch 102 and a multi-plate low speed stage brake B2 are provided between the sun gear 90 and the housing 64. They are provided in series. Engagement control of the high speed gear clutch C2 and the low speed gear brake B2 is controlled by a high speed gear hydraulic actuator 106 and a low speed gear hydraulic actuator 108, respectively. In the low-speed gear stage established by the engagement of the low-speed stage brake B2, the one-way clutch 1
02 prevents rotation of the sun gear 90 in the opposite direction to the ring gear 92 in the positive torque drive state, but permits rotation in the same direction as the ring gear 92 in the negative torque drive (engine braking) state to allow the drive wheel 26 to rotate. The power transmission path for transmitting the rotational force to the engine 10 side is released. Accordingly, when the high speed gear clutch C2 is released and the low speed gear brake B2 is engaged, the low speed gear position is established. In this state, when the output shaft 70 of the CVT 16 is rotated in the direction of advancing the vehicle, the carrier 98 and the second output shaft 96 are moved in the same direction as the rotation direction of the output shaft 70, and the gear ratio γ _AT (= the output shaft 70 Rotation speed / rotation speed of the second output shaft 96) = 1 + (the number of teeth Z _{S of the} sun gear 90 / the number of teeth Z _{R of the} ring gear 92). On the contrary, when the low speed gear brake B2 is released and the high speed gear clutch C2 is engaged, the high gear speed is established. In this state, the sun gear 90 and the carrier 98 are coupled to each other such that they cannot rotate relative to each other, so that the planetary gear device can be integrally rotated, and the second output shaft 96 is connected to the output shaft 70 at the gear ratio γ _AT = 1. Can be rotated in the same direction. The gear can be switched by engaging the high speed clutch C2 while the low speed brake B2 is engaged during forward travel.

The second output shaft 96 is provided with a first gear 110, and the second gear 1 provided on the intermediate shaft 112.
It is meshed with 14. The intermediate shaft 112 is rotatably arranged around an axis c parallel to the axis b of the second output shaft 96, and also has a large-diameter gear 11 of the differential gear device 22.
The third gear 118 meshed with the gear No. 6 is provided. Second
The gear 114 has a larger diameter than the first gear 110, and
18 has a smaller diameter than the second gear 114,
The reduction gear device 20 is constituted by the gear 110, the second gear 114, and the third gear 118. The differential gear device 22 is rotatably supported around an axis orthogonal to the drive shaft 24, and a pair of differential small gears 120 that rotate integrally with the large diameter gear 116 and mesh with the differential small gears 120. A pair of differential gears 12 connected to a drive shaft 24
2 and. Therefore, the power transmitted from the reduction gear device 20 is evenly distributed to the left and right drive shafts 24 in the differential gear device 22, and then the left and right front wheels (drive wheels).
26 is transmitted.

In FIG. 2, a throttle sensor 130 provided in an intake pipe (not shown) of the engine 10 supplies a signal representing the throttle valve opening θ _th to the electronic control unit 132. Further, for example, the engine rotation sensor 134 provided in the igniter or the like is used to determine the rotation speed N of the engine 10.
A signal representing _e is provided to the electronic controller 132. Also,
The input shaft rotation sensor 136 and the output shaft rotation sensor 138 provided in the housing 64 are the input shaft 5 of the CVT 16.
Signals representing the rotation speed N _{in of} 8 and the rotation speed N _out of the output shaft 70 are supplied to the electronic control unit 132, respectively. Further, the vehicle speed sensor 140 provided in the housing 64 for detecting the rotation of the drive shaft 24, that is, the front wheel 26,
A signal corresponding to the vehicle speed SPD is supplied to the electronic control unit 132. Further, the operation position sensor 144 is the shift lever 1
A signal representing the operating position P _{s of} 42 is supplied to the electronic control unit 132.

The electronic control unit 132 includes a CPU 146, R
A so-called microcomputer including an AM 148, a ROM 150, and an interface (not shown) is provided, and the CPU 146 uses the temporary storage function of the RAM 148 to process the input signal in accordance with a program stored in the ROM 150 in advance to change the gear ratio of the CVT 16. The first electromagnetic valve 152, the second electromagnetic valve 154, the third electromagnetic valve 156, and the fourth electromagnetic valve 154 for the control, the engagement control of the lockup clutch 38 of the fluid coupling 12, and the speed change control of the auxiliary transmission 18. The valve 158, the fifth solenoid valve 160, and the sixth solenoid valve 162 are driven.

FIG. 3 shows the relationship between the operating states of the forward clutch C1 and the reverse brake B1, the high speed clutch C2 and the low speed brake B2, which are controlled in relation to the operating position of the shift lever 142, and the shift speed. Is shown. In the figure, when the shift lever 142 is operated to the N (neutral) range, the high speed gear clutch C2 of the auxiliary transmission 18 is engaged. In the N range, if the forward clutch C1 and the reverse brake B1 of the forward / reverse switching device 14 are in the released state, the forward / reverse switching device 14 has a CV.
Since the power transmission to T16 is cut off, the operating states of the high speed clutch C2 and the low speed brake B2 of the auxiliary transmission 18 may be engaged or disengaged, but from the N range to the R (reverse) range. Alternatively, since only one friction engagement device needs to be actuated for switching to the D (drive) range, the switching control becomes easy, so N
In the range, the high speed clutch C2 is engaged as shown in the figure. Further, as shown in the figure, when the shift lever 142 is operated from the N range to the D range, the high speed gear clutch C2 is released and the low speed gear brake B2 is engaged after a predetermined time delay in the switching operation. As a result, the subduction of the vehicle is alleviated.
Also, when the shift lever is operated to the R range,
Since power is not transmitted due to slippage of the one-way clutch 102 when the low speed gear brake B2 is engaged, the low speed gear brake B2 is released and the high speed gear clutch C2 is engaged.

The hydraulic control circuit 170 shown in FIG. 2 is constructed, for example, as shown in FIG. 4, FIG. 5, FIG. 6, and FIG. 4 to 7, the hydraulic pump 40 constitutes a hydraulic pressure source of the hydraulic control circuit 170.
The hydraulic pump 40 sucks the working oil that has flowed back into an oil tank (not shown) through the strainer 174, and also sucks the working oil that is returned through the return oil passage 176 and sends it to the primary oil passage 178 under pressure. The hydraulic oil in the primary oil passage 178 is returned to the return oil passage 176 by the relief type primary pressure regulating valve 180.
By leaking to the clutch pressure oil passage 182, the primary line oil pressure P _r1 in the primary oil passage 178 is adjusted. 184 is a relief valve for preventing the primary line oil pressure P _r1 from being excessively increased.

The primary pressure regulating valve 180 is the spool valve element 1
90, the spool valve 1 through the spring seat 192
A return spring 194 that applies a biasing force to the valve 90 in the valve closing direction, a first plunger 196 that contacts the spool valve element 190, and a second plunger 198 that contacts the first plunger 196 and has the same diameter as that of the first plunger 196. The spool valve 190 has a port 200 that communicates with the primary oil passage 178.
The opening a is opened and closed between the drain port 200b communicating with the return oil passage 176 and the drain port 200c communicating with the clutch pressure oil passage 182. The spool valve 190 has a first
Land 202 and second land 204 having a diameter larger than that
And an oil chamber 206 for applying a feedback pressure to the end surface of the first land 202, and an oil chamber 208 between the first land 202 and the second land 204 is open to the atmosphere. A primary line hydraulic pressure P _r1 as a feedback pressure is applied to the oil chamber 206 via a throttle 210 to bias the spool valve element 190 in the valve opening direction. A first plunger 196 and a second plunger 198 provided coaxially with the spool valve element 190.
Between the hydraulic pressure P in the primary side hydraulic actuator 86 and
_in the oil chamber 212 is provided for guiding through the branch oil passage 210, and still end face of the second plunger 198 and the oil chamber 214 is provided for guiding the tension control pressure P _belt. The pressure receiving area of the first land 202 of the spool valve element 190 is A ₁ , the cross-sectional area of the first plunger 196 and the second plunger 198 is A ₃ , and the return spring 194.
Suppose that the biasing force of W is W, the spool valve element 190 is balanced at the position where Equation 1 holds and the primary line hydraulic pressure P
_r1 is regulated. Then, this primary line hydraulic pressure P _r1 is
Throttle valve opening detection valve 2 for adjusting the throttle pressure P _th
20, a valve pressure regulating valve 222 that regulates the valve pressure P _v supplied to each solenoid valve, a tension control pressure regulating valve 224 that regulates the tension control pressure, a member for engaging and operating the forward clutch C1 and the reverse brake B1. The combined actuating oil pressure _Pbc is supplied to the engaging actuating oil pressure regulating valve 226 which regulates the sum.

[0020]

[ _Equation 1] P _r1 = [(P _in or P _belt ) ・ A ₃ + W] / A ₁

In the primary pressure regulating valve 180, the primary side
Hydraulic pressure P in the hydraulic actuator 86 _inIs the tension control pressure P
_belt(P in steady state_belt= Secondary hydraulic actuator
Hydraulic pressure P in 88_out) Is higher than the first plan
The 196 and the second plunger 198 are spaced apart from each other and
Note Hydraulic pressure P in the primary side hydraulic actuator_inThrust by
Operates in the closing direction of the pool valve 190, but
Actuator hydraulic pressure P_inIs the tension control pressure P_beltLower than
If the first plunger 196 and the second plunger 1
Since 98 comes into contact with the second plunger 198,
Tension control pressure P acting on the end face_beltThrust by sp
The valve valve 190 in the valve closing direction. Ie the primary
Hydraulic pressure in side hydraulic actuator P_inAnd tension control pressure P_beltWhen
Whichever is higher, the thrust force based on the hydraulic pressure is the spool valve 1
It is operated in the valve closing direction of 90. By this
The primary line hydraulic pressure P_r1Is the primary hydraulic actuator
Internal oil pressure P_inAnd tension control pressure P_beltAnd whichever is higher
The pressure is adjusted to a value proportional to the pressure to generate the hydraulic pressure.
Force loss is reduced as much as possible.

The throttle valve opening detection valve 220 is engaged with a throttle cam 230 that is interlocked with a throttle valve that is rotated by operating an accelerator pedal (not shown), and the cam surface of the throttle cam 230. A plunger 232 whose axial position is changed in relation to the rotation angle of 230, a spool valve element 234 which regulates the throttle pressure P _th , and a spring 236 which biases this spool valve element 234 in the valve opening direction. I have it.
The spool valve element 234 is a valve closing valve that is generated based on the thrust in the valve opening direction given from the plunger 232 via the spring 238, the thrust in the valve closing direction of the spring 236, and the throttle pressure P _th acting as feedback pressure. by the direction of the thrust is brought into a position so as to balance, and reduces the primary line pressure P _r1, to generate a larger throttle pressure P _th with the throttle valve opening theta _th.

The valve pressure regulating valve 222 is positioned so that the thrust force applied from the spring 240 in the valve opening direction and the thrust force in the valve closing direction generated based on the valve pressure P _v acting as a feedback pressure are balanced. The spool valve element 242 is provided to reduce the pressure of the primary line hydraulic pressure P _r1 , which is the original pressure, to generate a constant valve pressure P _v regardless of the fluctuation. This valve pressure P _v is supplied to the third solenoid valve 156, the fourth solenoid valve 158, and the fifth solenoid valve 160, respectively. The third solenoid valve 156 and the fourth solenoid valve 158 have an input port to which the valve pressure P _v is supplied, a drain port, and
An ON state in which the spherical valve closes the drain port and communicates between the input port and the output port, and an OFF state in which the spherical valve closes the input port and communicates between the drain port and the output port. It is a 3-port 2-position valve that can be switched. In addition, the fifth solenoid valve 160
Includes a spool valve element 246 which is biased in the valve closing direction by the spring 244 and the feedback pressure, and a linear solenoid 248 which biases the spool valve element 246 in the valve opening direction by a thrust force corresponding to the exciting current. It is configured to generate a signal pressure P _lin that increases according to the exciting current.

The tension control pressure regulating valve 224 includes a spool valve element 262 for opening and closing a primary oil passage 178 for guiding the primary line oil pressure P _r1 and a tension control pressure oil passage 260 for guiding the tension control pressure P _belt , and a spring seat. A return spring 266 that applies an urging force in the valve opening direction to the spool valve element 262 via 264, and a plunger 268 that abuts on the spool valve element 262 to apply the urging force in the valve opening direction. In addition, a first land 270 and a second land 272, whose diameters gradually increase, are sequentially formed at the shaft end of the spool valve element 262. An oil chamber 276 is provided between the first land 270 and the second land 272, and a tension control pressure P _belt as a feedback pressure is introduced through the throttle 274. The signal pressure P output from the fifth solenoid valve 160 is applied to the end surface side of the first land 270 of the spool valve element 262.
An oil chamber 278 in which _lin acts is provided, and the spool valve element 262 is biased in the valve closing direction based on the gear ratio γ _cvt . The plunger 268 has a third land 2 whose diameter decreases in order from the spool valve 262 side.
80 and the fourth land 282 are provided. An oil chamber 284 for applying the throttle pressure P _th is provided on the end face side of the fourth land 282, and the spool valve 26
2 is biased in the valve opening direction by the throttle pressure P _th . An oil chamber 286, on which the signal pressure P _sol4 output from the fourth solenoid valve 158 acts, is provided between the third land 280 and the fourth land 282, and the signal pressure P _sol4 is generated. In the case where the tension control pressure P
_{The belt} is designed to be raised by a predetermined pressure. Therefore, the pressure receiving area of the first land 270 is A ₄ , the cross sectional area of the second land 272 is A ₅ , the cross sectional area of the third land 280 is A ₆ , the pressure receiving area of the fourth land 282 is A ₇ , and the return When the urging force of the spring 266 is W, the spool valve element 262 is balanced at the position where Equation 2 holds. That is, the spool valve element 262 is moved according to the mathematical expression 2, so that the primary line hydraulic pressure P _r1
Is reduced to generate the tension control pressure P _belt , which is supplied to the secondary-side hydraulic actuator 88. As described above, the tension control pressure P _belt is basically adjusted based on the throttle valve opening θ _th corresponding to the output torque of the engine 10 and the gear ratio γ _cvt , so that the tension of the transmission belt 76,
That is, the clamping pressure is controlled to a necessary and sufficient value, the power loss is reduced, and the durability of the transmission belt 76 is improved.

[0025]

[ _Formula 2] P _belt = [A ₇ · P _th + (A ₆ −A ₇ ) P _sol4 + W −A ₄ · P _lin ] / (A ₅ −A ₄ ).

The engagement actuating hydraulic pressure regulating valve 226 opens the spool valve element 292 via a spool valve element 292 that opens and closes between the primary oil passage 178 and the engagement operation pressure oil element 290, and a spring seat 294. Spring 29 that urges in the direction
6, and a plunger 298 that abuts on the spool valve 292.
It has and. The spool valve element 292 has a first land 300 and a second land 302 having a diameter increasing from the end thereof.
Is provided, and between the first land 300 and the second land 302, an oil chamber 304 in which the engagement operating oil pressure _Pbc acts as a feedback pressure is provided.
Further, the plunger 298 includes a spool valve 292.
A third land 306 and a fourth land 308 having a smaller diameter are provided in order from the side, and a manual valve is provided between the third land 306 and the fourth land 308 when the shift lever 142 is operated to the R range. An oil chamber 312 is provided to which the R range pressure P _R output from 310 is supplied. Further, the oil chamber 314 for receiving the throttle pressure P _th acting on the end surface of the fourth land 308.
Is provided. Therefore, the spool valve 292
Is the throttle pressure P _th or the throttle pressures P _th and R
The thrust force in the valve opening direction based on the range pressure P _R and the thrust force in the valve opening direction based on the spring 296 are actuated so that the thrust force in the valve closing direction based on the feedback pressure is balanced.
Generating an engaging hydraulic pressure P _bc having a magnitude corresponding to the throttle pressure P _th. Further, when the R range pressure P _R is supplied, the engagement operating oil pressure P _bc is increased by a predetermined pressure. As a result, the engagement operating oil pressure P _bc is increased in accordance with the throttle pressure P _th, that is, the output torque of the engine 10, and is further increased by a predetermined pressure when the shift lever 142 is operated to the R range. Clutch C1, reverse brake B1, high speed clutch C
2 or the low-speed stage brake B2 is engaged with a necessary and sufficient thrust. The engagement operating oil pressure P
_bc is also supplied to the first solenoid valve 152, the second solenoid valve 154, and the sixth solenoid valve 162. The sixth solenoid valve 162 is configured similarly to the above-mentioned third solenoid valve 156 and fourth solenoid valve 158, while the first solenoid valve 152 and the second solenoid valve 154 are throttled when in the off state. 318 and 32
It is a two-port two-position valve that opens the downstream side from 0 to the drain, but makes the downstream sides from the throttles 318 and 320 the engaging hydraulic pressure _Pbc when in the on state.

The first solenoid valve 152 is a gear shift direction switching valve 330 for switching the gear ratio change direction of the CVT 16.
The second solenoid valve 154 controls the shift speed control valve 332 for controlling the speed change ratio of the CVT 16. The shift direction switching valve 330 has a first input port 334 that communicates with the primary oil passage 178, a second input port 338 that communicates with the primary oil passage 178 via a medium throttle 336, a relatively small throttle 340, and a relatively large throttle. The first output port 344, which communicates with the hydraulic actuator 86 on the primary side via the throttle 342, and the input port 3 of the transmission speed control valve 332.
Second output port 348 and drain port 3 communicating with 46
50, between the first input port 334 and the first output port 344 in the off position and the second input port 338.
And the second output port 348, respectively, but at the ON position, the spool valve element 352 that allows the second output port 348 and the drain port 350 to communicate with each other.
And a spring 354 that urges the spool valve element 352 toward the off position. Therefore, when the first solenoid valve 152 is turned off, the spool valve element 3
52 is located at the off position, hydraulic oil is supplied into the hydraulic actuator 86 on the primary side, and the CVT 16 is changed in the speed increasing direction. On the contrary, when the first solenoid valve 152 is turned on, the spool valve element 352 is positioned at the on position and the hydraulic oil in the hydraulic actuator 86 on the primary side is discharged from the drain port 350 to CVT1.
6 is changed in the deceleration direction.

The transmission speed control valve 332 connects the input port 346, the output port 356 communicating with the primary-side hydraulic actuator 86, the input port 346 and the output port 356 in the ON position, and the OFF position. 2 includes a spool valve element 358 that shuts off the valve and a spring 360 that biases the spool valve element 358 toward the off position. Therefore, when the second solenoid valve 154 is turned off, the spool valve element 358 shuts off between the input port 346 and the output port 356, so that the slow deceleration mode is set when the first solenoid valve 152 is on. When the first solenoid valve 152 is in the off state, the slow speed increasing mode is set. When the second solenoid valve 154 is turned on, the spool valve element 358 allows the input port 346 and the output port 356 to communicate with each other.
When the first electromagnetic valve 152 is in the off state, the rapid speed increase mode is set, and when the first electromagnetic valve 152 is in the on state, the rapid deceleration mode is set. FIG. 8 shows the relationship between the combination of the operating states of the first solenoid valve 152 and the second solenoid valve 154 and the shift mode of the CVT 16 obtained thereby.

The manual valve 310 is equipped with a spool valve element 364 that works in conjunction with the shift lever 142, a first port 366, a second port 368, and a third port 370. , the engaging hydraulic pressure P _bc whose pressure regulated by the engaging hydraulic pressure regulating valve 226 is supplied as a source pressure. From the first port 366,
When the shift lever 142 is operated to the forward range such as the D range, the S range, and the L range, the forward range pressure P _F is output, and the shift lever 14 is output from the third port 370.
When 2 is operated to the R range, the reverse range pressure P _R is output.

The forward range pressure P _F output from the first port 366 is passed through the throttle 374 or the throttle 37.
6 and the shift timing valve 378 to supply the hydraulic actuator 42 for forward movement. The spool valve element 380 of the shift timing valve 378 moves against the spring 382 in response to the increase in the hydraulic pressure in the forward hydraulic actuator 42, and suppresses the inflow flow rate. When the shift lever 142 is operated to a range other than the forward range, the hydraulic oil in the forward hydraulic actuator 42 causes the check valve 38 to move.
4 and through the manual valve 310 to drain quickly.

Further, when the shift lever 142 is operated to the R range, the reverse range pressure P _R output from the third port 370 causes the oil chamber 31 of the engagement actuation hydraulic pressure regulating valve 226 to move.
2 and the reverse inhibit valve 37
2 and the throttle 386, and is supplied to the reverse hydraulic actuator 44. On the contrary, when the shift lever 142 is operated to a range other than the R range, the hydraulic oil in the reverse hydraulic actuator 44 is gently discharged to the drain through the check valve 387, the reverse inhibit valve 372, and the manual valve 310. The reverse range P _R is set to atmospheric pressure.

The reverse inhibit valve 372 has a first land 388, a second land 390 having a larger diameter than that, and a third land 392 having the same diameter as the first land 388.
The spool valve element 394 that opens and closes between the third port 370 and the reverse hydraulic actuator 44 by 0, and the spring 39 that urges the spool valve element 394 in the valve opening direction.
6 and a plunger 398 contacting the spool valve 394 for urging the spool valve 394 in the valve opening direction. Also,
The plunger 398 has the same sectional area as the sectional area difference between the first land 388 and the second land 390. A signal pressure P _sol3 generated when the third solenoid valve 156 is in the ON state (engagement state of the lockup clutch 38) is applied to the end surface of the first land 388, and the first land 388 and the first land 388 are connected to each other. The reverse range pressure P _R is applied between the two lands 390. Further, the engagement actuating oil pressure P _bc is constantly applied to the end surface of the plunger 398, and the spool valve element 394 and the plunger 398 are provided.
The hydraulic pressure in the reverse hydraulic actuator 44 is applied between and. Therefore, the reverse range pressure P _R urges the spool valve 394 in the valve opening direction and the engagement operating oil pressure P _bc causes the spool valve 394 to move.
When the shift lever 142 is operated to the R range (reverse range), the spool valve element 394 is moved to the valve open position by the urging force of the spring 396. The spool valve element 394 is positioned in the valve closing direction, that is, the inhibit position when the signal pressure P _sol3 is _{applied while} being positioned.
Therefore, since the signal pressure P _sol3 is being _applied during forward traveling with the lock-up clutch 38 engaged, when the shift lever 142 is operated to the R range (reverse range), the spool When the valve element 394 is moved to the valve closing position, the reverse hydraulic actuator 44 causes the reverse inhibit valve 372 to drain the port 4 of the drain port 4.
00, and the operation of the reverse brake B1 is blocked. However, once the reverse drive range pressure P _R is applied to the reverse drive hydraulic actuator 44, the reverse drive range pressure P _R generates thrust in the valve opening direction of the spool valve 394, so that even the signal pressure P _sol3 acts. Even if the spool valve 394 is operated, the spool valve element 394 is held in the valve opening position.

The forward hydraulic actuator 42 and the reverse hydraulic actuator 44 are provided with a throttle pressure P _th.
Accumulator 402, which is operated as back pressure
And 404 are connected to each other, and as the transmission torque increases, their forward hydraulic actuators 42
Also, the increase in the hydraulic pressure in the reverse hydraulic actuator 44 is moderated so that the forward clutch C1 and the reverse brake B1 are engaged smoothly.

The high speed clutch C2 and the low speed brake B2 of the auxiliary transmission 18 are switched by a sixth solenoid valve 162, ie, a C2 control valve 410 and a B2 control valve 412.
It can be switched by. The C2 control valve 410 has an output port 414 that communicates with the high-speed hydraulic actuator 106, and an engagement operating oil pressure P _bc restricts the output port 414.
The hydraulic oil is supplied to the port 416 supplied via the
And a spring 422 for biasing the spool valve element 420 toward the engaging side position, and a spring 422 for accommodating the spring 422. An oil chamber 424 that receives the signal pressure P _sol6 from the sixth solenoid valve 162
And an oil chamber 426 connected to the low speed hydraulic actuator 108 via a throttle 425 in order to apply the hydraulic pressure in the low speed hydraulic actuator 108 to the end surface of the spool valve element 420 on the side opposite to the spring 422 side. It has and. Therefore, in the C2 control valve 410, the oil chamber 42
4 and the oil chamber 426 are both at atmospheric pressure, or when the signal pressure P _sol6 and the oil pressure in the low-speed hydraulic actuator 108 are being supplied to the oil chamber 424 and the oil chamber 426, respectively, the spool valve element 420 is The clutch C2 for the high speed stage is engaged by the hydraulic actuator 106 for the high speed stage which is located on the engagement side. However, when the oil pressure in the low-speed hydraulic actuator 108 is supplied to the oil chamber 426 while the oil chamber 424 is at the atmospheric pressure, the spool valve element 420 moves to the non-engaging side position (off-side position in FIG. 7). When positioned, the hydraulic oil in the high speed gear hydraulic actuator 106 is drained and the high speed gear clutch C2 is released. The accumulator 428 supplied with the engagement actuation pressure P _bC or the throttle pressure P _th as a back pressure via the B2 control valve 412 is for smooth engagement of the high speed clutch C2.

Further, the B2 control valve 412 controls the engagement operating pressure P
The first port 430 to which _bC is supplied, the second port 432 to which the throttle pressure P _th is supplied, the drain port 434, the third port 436 connected to the low speed _gear hydraulic actuator 108, and the forward range pressure P _f are supplied. 4th port 4
38, the fifth connected to the back pressure chamber of the accumulator 428
The port 440 and the fifth port 440 are the first port 4
30 or the second port 432, and a spool valve element 442 for selectively switching the third port 436 to the drain port 434 or the fourth port 438, and the spool valve element 442 at the engagement side position. Spring 444 that urges toward
And an oil chamber 446 that receives the oil pressure in the forward hydraulic actuator 42, and an oil chamber 448 that receives the signal pressure P _sol6 on the end surface of the spool valve element 442 opposite to the spring 444. Is equipped with. Therefore, in the B2 control valve 412, when both the oil chamber 446 and the oil chamber 448 are at the atmospheric pressure,
46 and the oil chamber 448, the forward hydraulic actuator 42
When the internal hydraulic pressure and the signal pressure P _sol6 are respectively supplied, the spool valve element 420 is positioned on the engagement side, and the low speed hydraulic brake 108 engages the low speed brake B2. However, when the signal pressure P _sol6 is supplied to the oil chamber 448 while the oil chamber 446 is at the atmospheric pressure, the spool valve element 442 is positioned at the non-engagement side position, and the hydraulic actuator 108 for the low speed stage has The hydraulic oil is drained, and the low speed brake B2 is released.

When the shift lever 142 of the vehicle is operated to the R (reverse) range or the N (neutral) range, the sixth solenoid valve 162 is held in the ON state as shown in FIG. Since the signal pressure P _sol6 in the oil chamber 424 of 410 is applied, the spool valve element 420 of the C2 control valve 410 is moved to the engagement position (ON position in FIG. 7) and the high speed clutch C2 is engaged. Since the forward range pressure P _F is not output from the manual valve 310, the low-speed stage brake B2 is released regardless of the operating position of the B2 control valve 412, and the auxiliary transmission 18 is in the direct connection state. Power transmission is interrupted only in the forward / reverse switching device 14 in the power transmission path. As a result, the CVT 16 is rotated even when the shift lever 142 is operated to the N range while the vehicle is traveling, so that the gear ratio control of the CVT 16 is enabled. Further, since the auxiliary transmission 18 is directly connected in the N range and the R range as described above, when the shift lever 142 is operated from the N range to the R range or the D range,
Since only one frictional engagement device, which is the forward clutch C1 or the reverse brake B1, needs to be engaged, the forward gear stage or the reverse gear stage can be established without requiring complicated timing control. FIG. 9 shows the hydraulic actuator 106 for the high speed stage when the shift lever 142 is operated to the R range or the N range as described above.
Hydraulic pressure (C2 pressure) and low speed hydraulic actuator 1
The hydraulic pressure of 08 (B2 pressure) is shown. When the shift lever 142 is operated to the R range, the R force is adjusted so that the engaging force corresponding to the transmission torque of the reverse gear is obtained.
The range pressure P _R is the oil chamber 312 of the engaging actuation hydraulic pressure regulating valve 226.
Is applied to increase the engagement operating pressure _Pbc by a predetermined pressure,
B2 pressure is higher than C2 pressure.

When the vehicle is required to travel backward, the low-speed stage brake B2 does not generate the forward range pressure P _F as described above, and therefore, regardless of the position of the valve element 442 of the B2 control valve 412. While in the released state, the oil chambers 424 and 42 of the C2 control valve 410 are associated with this.
6 is the atmospheric pressure, and the valve element 420 is the sixth solenoid valve 162.
The high speed gear clutch C2 is brought into the engaged state by being preferentially placed in the ON position regardless of the operating position of. Therefore, as described in detail later, the B2 control valve 412
Even if the valve element 442 of the above is stuck in the off position or cannot be turned on due to the failure of the sixth solenoid valve 162, the vehicle can travel backward in response to the operation of the shift lever 142. Becomes

However, immediately after the shift lever 142 is operated from the N range to the D (forward) range, the drive torque is gently changed by establishing the low speed gear after passing through the high speed gear having a small gear ratio. The control is started, and during the squat control period, as shown in FIG. 3, the high speed stage crack C2 and the low speed stage brake B2.
Is held in the same state as the N range up to that point. That is, the electronic control unit 132 maintains the ON state of the sixth solenoid valve 162, and the spool valve 42 of the C2 control valve 410 is maintained.
0 is set to the engagement position (ON position in FIG. 7) and the high speed clutch C2 is continuously engaged. In this state, the forward range pressure P from the manual valve 310 is increased.
_F is output to supply hydraulic oil into the forward hydraulic actuator 42 that engages the forward clutch C1 and into the oil chamber 446 of the B2 control valve 412, and the hydraulic pressure (C1 pressure) in the forward hydraulic actuator 42 is reduced. Although it slowly rises due to the action of 374, 376 and the accumulator 402, the signal pressure P _sol6 is exerted in the oil chamber 448 of the B2 control valve 412 until it rises, and the spool valve element 442 of the spool valve element 442 is in the disengaged position ( 7) and the state in which the low speed gear hydraulic actuator 108 that operates the low speed gear brake B2 is drained is maintained, so in the auxiliary transmission 18, only the high speed gear clutch C2 is provided. It will be in the engaged state.

The forward clutch C is associated with the operation of the shift lever 142 from the N range to the D range.
When the engagement of No. 1 is completed, for example, the rotation of the output shaft 34 that has been rotating until then is stopped, or when about 0.7 seconds elapses from the start of the squat control, the squat control is ended. For this purpose, the sixth solenoid valve 162 is switched off by the electronic control unit 132. As a result, the oil chamber 448 of the B2 control valve 412, to which the signal pressure P _sol6 has been _applied until then, is brought to the atmospheric pressure, and the spool valve element 442 is in the engagement position (OFF position in FIG. 7).
As the forward range pressure P _F is supplied to the low speed hydraulic actuator 108 that operates the low speed brake B2, the low speed brake B2 is engaged. At the same time, the oil chamber 424 of the C2 control valve 410, to which the signal pressure P _sol6 has been _applied until then, is set to the atmospheric pressure, while the pressure of the hydraulic oil in the low speed hydraulic actuator 108 is C2 controlled via the throttle 425. Since the spool valve element 420 is also acted on the oil chamber 426 of the valve 410, the spool valve element 420 is positioned at its disengaged position (off position in FIG. 7) against the biasing force of the spring 422, and the high speed stage clutch C2.
Is released. That is, when the squat control that is temporarily executed in association with the operation of the shift lever 142 from the N range to the D range is completed, the low speed gear stage is established in the auxiliary transmission 18 as described above. The driving force at the start of the vehicle is obtained. Figure 10
Shows C1 pressure, C2 pressure, and B2 pressure that change in response to the shift lever 142 being operated from the N range to the D range. As described above, the sixth solenoid valve 1
Even if 62 is not switched from the ON state to the OFF state,
When the C1 pressure for engaging the forward clutch C1 increases in association with the shift lever 142 being operated from the N range to the D range, the spool valve element 420 of the B2 control valve 412 is located at the off position in FIG. 7. Then, the low-speed stage brake B2 is engaged.

Here, when the shift lever 142 is operated from the N range to the D range to establish the low speed gear after the squat control period, the pressure of the hydraulic oil in the low speed hydraulic actuator 108 rises. Since the spool valve element 420 of the C2 control valve 410 is configured to be moved to its non-engagement position based on the above, as shown in FIG. 10, the engagement pressure of the low-speed stage brake B2 (≈B2 pressure). ) Has reached a value α for generating a thrust corresponding to at least the biasing force of the spring 422 (for example, 2.5 to 3 kg), the disengagement of the high speed clutch C2 is started. As a result, the period in which both the low speed gear brake B2 and the high speed gear clutch C2 are temporarily overlapped is provided at a minimum and reliably, so that the auxiliary transmission 18 shifts from the high speed gear speed to the low speed gear speed. The shift shock that occurs in connection with the shift to the gear is preferably prevented, and the engine 10 is surely prevented from rising. It should be noted that this temporary overlapping engagement causes the size of the throttle 425 to be large so that the lock of the auxiliary transmission 18 is not strongly felt even when the shift lever 142 is operated from the N range to the D range while the vehicle is moving in reverse. And the biasing force of the spring 422 is set.

In the traveling state in which the low speed gear stage is established as described above, for example, Japanese Patent Laid-Open No. 61-241561.
As described in the publication, when the running state of the vehicle is within the permission range for switching from the low-speed gear stage to the high-speed gear stage in the shift diagram shown in FIG.
2 switches the sixth solenoid valve 162 from the off state to the on state. As a result, in the C2 control valve 410, when the signal pressure P _sol6 is _applied to the oil chamber 424 that has been at atmospheric pressure until then, the spool valve element 420 is positioned at its engagement position (on position in FIG. 7). Therefore, the engagement operating oil pressure P _bc passes through the throttle 415 so that the high-speed hydraulic actuator 1
It is supplied to the inside of 06, and the high speed gear clutch C2 is engaged. At the same time, the B2 control valve 412 that was at atmospheric pressure until then
Although the signal pressure P _sol6 is also applied to the oil chamber 448 of the B2 control valve 412, the hydraulic pressure in the hydraulic actuator 42 for advance acting on the oil chamber 446 of the B2 control valve 412 is already the forward range pressure P.
_Since it reaches _{F, the} spool valve element 442 is held in the engagement position by the biasing force of the spring 444. That is, in the auxiliary transmission 18, the low-speed stage brake B2
Thus, the high speed gear clutch C2 is engaged in the engaged state, and the high speed gear position is established. FIG. 12 shows changes in the C2 pressure and the B2 pressure when the sixth electromagnetic valve 162 is switched from the off state to the on state in order to obtain the high speed gear stage in the traveling state in the low speed gear stage.

When a kick-down operation is performed in which the accelerator pedal (not shown) is greatly depressed while the vehicle is traveling in the high gear, the sixth solenoid valve 162 is switched from the on state to the off state by the electronic control unit 132. .. As a result, the signal pressure P _sol6 acting on the oil chamber 448 of the B2 control valve 412 becomes atmospheric pressure, but the spool valve element 442 is already positioned at the engagement position due to the operating oil pressure in the forward hydraulic actuator 42. Therefore, the engagement position is maintained as it is. At the same time, since the oil chamber 424 of the C2 control valve 410, to which the signal pressure P _sol6 has been _applied until then, is set to the atmospheric pressure, the spool valve 420
Is a disengaged position (OFF position in FIG. 7) against the biasing force of the spring 422 by the thrust force based on the pressure (forward range pressure P _F ) in the low speed hydraulic actuator 108 acting in the oil chamber 426. ), The hydraulic oil in the high speed gear hydraulic actuator 106 is discharged through the throttle 417 and the drain port 418, so that the high speed gear clutch C2 is released and the low gear speed is established. Further, as described in Japanese Patent Laid-Open No. 61-241561, when the actual gear ratio γ _CVT falls below a predetermined value γ _o, which is the same as the above, while the vehicle is traveling. The downshift of the auxiliary transmission 18 is executed. FIG. 13 shows changes in the C2 pressure and the B2 pressure when the sixth solenoid valve 162 is switched from the ON state to the OFF state in order to obtain the low speed gear stage in the traveling state in the high speed gear stage.

Even during the squat control period immediately after the operation from the N range to the D range, when the accelerator pedal is depressed, the sixth solenoid valve 162 is immediately turned off by the electronic control unit 132. It is switched to the state. As a result, the signal pressure P _sol6 acting on the oil chamber 448 of the B2 control valve 412 is set to the atmospheric pressure, and the biasing force of the spring 444 causes the spool valve 4 to move.
Since 42 is moved from the previously disengaged position to the engaged position, hydraulic oil is supplied to the low-speed hydraulic actuator 108. At the same time, since the oil chamber 424 of the C2 control valve 410, to which the signal pressure P _sol6 has been applied, is set to the atmospheric pressure, the spool valve element 420 causes the spool valve element 420 to operate in the oil chamber 426. Since the thrust force based on the internal pressure (forward range pressure P _F ) resists the urging force of the spring 422 to the disengaged position (OFF position in FIG. 7), the operation in the high-speed hydraulic actuator 106 is performed. Oil throttle 417 and drain port 4
High speed stage clutch C by being discharged through 18
2 is released and the low gear is established. 14
Shows the changes in C1 pressure, C2 pressure, and B2 pressure when the accelerator pedal is depressed during the squat control period.

Further, when the shift lever 142 is operated from the D range to the R range in a state of the low speed gear stage of the auxiliary transmission 18 such as during low speed forward running immediately before stop, the manual valve 310 is used until then. At the same time as the engagement of the reverse brake B1 is started by the reverse hydraulic actuator 42 releasing the engaged forward clutch C1, the sixth solenoid valve 162 is switched from the off state to the on state as shown in FIG. As a result, the engagement of the high speed gear clutch C2 that has been in the disengaged state is started. At this time, the forward hydraulic actuator 42
The inside and the oil chamber 446 of the B2 control valve 412 are exhausted by the manual valve 310, and the signal pressure P _sol6 from the sixth solenoid valve 162 is applied to the oil chamber 448 of the B2 control valve 412. Since the spool valve element 442 of 412 is moved to the ON position, the back pressure of the accumulator 428 is switched to the engagement operating pressure P _bc higher than P _th . As a result, as shown by the broken line in FIG. 15, the transient hydraulic pressure in the high-speed hydraulic actuator 106 when the shift lever 142 is operated from the D range to the R range is shown by the solid line by the action of the accumulator 428. The clutch capacity C2 for the high speed gear is higher than that in the case of a normal gear change, and the engagement capacity of the clutch C2 for the high speed gear is higher than that of the reverse brake B1.

Therefore, as described above, the shift lever 1
When 42 is operated from the D range to the R range, the engagement capacity of the high speed gear clutch C2 is higher than that of the reverse brake B1. Therefore, the high speed gear clutch C2 is engaged first, and then the reverse gear. Since the brake B1 is engaged, the two-stage shift shock associated with the engagement of the high speed clutch C2 and the engagement of the reverse brake B1 is eliminated. The shift shock at this time is the reverse brake B.
The same measure as in the case of the operation to the normal R range in which the aperture 386, the accumulator 404, etc. are set to loosen the engagement of 1 is dealt with. Regarding the engagement of the high speed gear clutch C2, there is an advantage that it is sufficient to set the characteristics of the accumulator 428 only in consideration of alleviating the shift shock at the time of switching from the low speed gear position to the high speed gear position. is there.

Further, in the hydraulic control circuit 170, two control valves, the C2 control valve and the B2 control valve, are independently provided as control valves for the high speed clutch C2 and the low speed brake B2. In addition, upshifting or downshifting of the auxiliary transmission 18 is performed by the high speed gear clutch C2.
It is possible to smoothly execute the engagement or disengagement of only the high speed stage clutch C2 when the squat control period is completed to establish the low speed stage. By engaging the stage brake B2 and then releasing the high stage brake B2, the low speed gear stage can be smoothly established by the action of the one-way clutch 102. Therefore, complicated timing control of the high speed clutch C2 and the low speed brake B2 is required regardless of variations in the engagement operation time and the release operation time of the high speed clutch C2 and the low speed brake B2. The engagement control of the auxiliary transmission 18 is smoothly performed without the need. In addition, depending on whether or not the spool valve element 442 of the B2 control valve 412 is preferentially positioned at the position for engaging the low speed stage brake B2 by the hydraulic pressure in the forward hydraulic actuator 42,
Only one of the two control valves B2 control valve 412 and C2 control valve 410 can be switched by the single sixth solenoid valve 162, or both can be switched at the same time. Thus, the hydraulic control device becomes simpler than when controlling the B2 control valve 412 and the C2 control valve 410, respectively.

Next, in order to control engagement and disengagement of the lockup clutch 38, a lockup relay valve 460 which is switched by the third solenoid valve 156 and a lockup control valve 46 which is switched by the fourth solenoid valve 158.
Two are provided. The lockup relay valve 460 is
The first port 468 and the second port 47 to which the clutch hydraulic pressure P _cl is supplied via the drain port 464 and the check valve 466.
0, the third port 472, the fourth port 474, the fifth port 476, the drain port 478, the spool valve element 480 for switching among these ports, and the spool valve element 480 is biased toward the oil chamber 482 side. And a spring 484. Therefore, in a state where the signal pressure P _sol3 from the third solenoid valve 156 is not supplied to the oil chamber 482, the spool valve element 480 is positioned on the oil chamber 482 side, so that the first port 468, the second port 470, and the 3 port 472
The fourth port 474, the fifth port 476 and the drain port 478 are communicated with each other. On the contrary, in the state where the signal pressure P _sol3 from the third solenoid valve 156 is supplied to the oil chamber 482, the spool valve element 480 is positioned on the oil chamber 482 side, so the drain port 464 and the second port 470,
First port 468, third port 472, fourth port 47
The fourth and fifth ports 476 are communicated with each other.

The lockup control valve 462 is the check valve 46.
First port 4 to which clutch oil pressure P _cl is supplied via 6
90, the second port 470 of the lockup relay valve 460
Second port 492 connected to the third port 49 connected to the fifth port 476 of the lockup relay valve 460.
4, fourth port 496 connected to third port 472 of lockup relay valve 460, fluid coupling 1
5, a fifth port 498 connected to the release side oil chamber 46, a sixth port 500 connected to the engagement side oil chamber 48 of the fluid coupling 12, and a spool valve 502 for switching between these ports. , And a spring 506 that biases the spool valve 502 toward the oil chamber 504. Therefore, when the signal pressure P _sol4 from the fourth solenoid valve 158 is not supplied to the oil chamber 504, the spool valve 50
2 is located on the oil chamber 504 side, the second port 4
92 and the 5th port 498, and the 4th port 496 and the 6th port 500 are connected, respectively. On the contrary, in the state where the signal pressure P _sol4 from the fourth solenoid valve 158 is supplied to the oil chamber 504, the spool valve element 502 is positioned on the spring 506 side, so the first port 490 and the fifth port 4
98, the third port 494 and the sixth port 500 are communicated with each other.

Therefore, when the third solenoid valve 156 is turned off while the fourth solenoid valve 158 is off, the clutch hydraulic pressure P _cl changes the first port 468 and the second port 470.
The engagement side oil chamber 48 is simultaneously acted on the release side oil chamber 46 through the second port 492 and the fifth port 498.
The hydraulic oil inside is the sixth port 500, the fourth port 496, the third port 472, the fourth port 474, the oil cooler 51.
The lock-up clutch 38
Is released. At this time, part of the hydraulic oil discharged from the engagement side oil chamber 48 is also drained through the oil cooler 510. A cooler bypass valve 512 is provided on the upstream side of the oil cooler 510 for draining the hydraulic oil discharged from the engagement side oil chamber 48 without passing through the oil cooler 510 when the pressure exceeds a predetermined value. ing. Further, when the third solenoid valve 156 is turned on while the fourth solenoid valve 158 is turned on, the clutch hydraulic pressure P _cl changes the first port 49.
The hydraulic oil in the engagement-side oil chamber 48 is applied to the release-side oil chamber 46 via the 0th and 5th ports 498, and at the same time, the working oil in the engagement-side oil chamber 48 is the 6th port 500, the 3rd port 494, the 5th port 476, and the 4th port After draining through 474 and the oil cooler 510, the lockup clutch 38 is released. There are two modes for disengaging the lockup clutch 38.

In the ON state of the fourth solenoid valve 158, the third solenoid valve 158
When the solenoid valve 156 is turned off, the clutch hydraulic pressure P _cl
Is acted on the release side oil chamber 46 via the first port 490 and the fifth port 498, and at the same time, the hydraulic oil in the engagement side oil chamber 48 is changed to the sixth port 500, the third port 494, the fifth port.
The lockup clutch 38 is quickly released by being drained through the port 476 and the drain port 478.
In this case, the hydraulic oil in the engagement side oil chamber 48 is allowed to flow to the drain without passing through the oil cooler 510, and the signal pressure P _sol4 from the fourth solenoid valve 158 is _applied to the tension control pressure regulating valve. The tension control pressure P is exerted on the oil chamber 286 of 224.
_{As the belt} is increased, the tension control pressure P _belt is also applied to the oil chamber 214 of the primary pressure regulating valve 180 to increase the primary line hydraulic pressure P _r1. Therefore, the throttle valve opening based on this primary line hydraulic pressure P _r1 is used. The throttle pressure P _th output from the detection valve 220 is also increased, and the clutch pressure regulating valve 450
Since the clutch pressure P _cl regulated at is increased, the lockup clutch 38 is rapidly released. Such a rapid release mode of the lockup clutch 38 is selected when executing the rapid deceleration shift of the CVT 16 in association with the sudden stop of the vehicle.

In the off state of the fourth solenoid valve 158, the third
When the solenoid valve 156 is turned on, the clutch hydraulic pressure P _cl
Is the first port 468, the third port 472, the fourth port 4
96 and the sixth port 500, the hydraulic oil in the disengagement side oil chamber 46 is made into the fifth
Port 498, second port 492, second port 470,
It is drained through the drain port 464 and the lockup clutch 38 is engaged.

In the electronic control unit 132, the CVT 16
Gear ratio control, lockup clutch 38 engagement control,
Sudden deceleration control of CVT 16, tension control pressure control, auxiliary transmission 1
8 gear shift control, etc. are executed. In the gear ratio control of the CVT 16, for example, the first control is performed so that the engine 10 operates along an optimum curve that provides fuel economy and drivability.
The solenoid valve 152 and the second solenoid valve 154 are driven to adjust the gear ratio γ _CVT . Also, lock-up clutch 3
In the engagement control of No. 8, for example, it is determined from the relationship stored in advance based on the vehicle speed SPD and the throttle valve opening θ _th whether or not it is the engagement region, and when it is determined to be the engagement region, When the fourth solenoid valve 158 is turned off, the third solenoid valve 156 is turned on, and when it is determined that it is in the release area, the third solenoid valve 156 is also turned off with the fourth solenoid valve 158 turned off. Turned off. In the rapid deceleration control of the CVT 16 prior to the sudden stop of the vehicle, both the first electromagnetic valve 152 and the second electromagnetic valve 154 are turned on to enter the rapid deceleration shift mode, and the third electromagnetic valve 156 is turned off. The fourth solenoid valve 158 is turned on and the lockup clutch 38 is quickly released.
Further, in the tension control pressure control, for example, the tension control pressure P _{belt applied} to the secondary side hydraulic actuator 88 is stored in advance so as to obtain a target pressure that is a small value in a range in which the transmission belt 76 does not slip. The fifth solenoid valve 160 is controlled based on the established relationship. In the shift speed switching control of the auxiliary transmission 18, for example, as described in Japanese Patent Laid-Open No. 61-241561 or Japanese Patent Laid-Open No. 62-137239, the actual throttle valve opening is determined from the relationship stored in advance. The gear stage to be switched is determined based on θ _th and the gear ratio γ _CVT or the vehicle speed SPD. If the determination result is the high gear stage, the sixth solenoid valve 162 is turned on, and if it is the low gear stage, the sixth solenoid valve is turned on. 162 is turned off.

As described above, according to this embodiment, as shown in FIG.
As shown in the upper stage, when the shift lever 142 is operated to the R range and the vehicle is required to travel in reverse, the high speed stage clutch C2 is operated by the sixth solenoid valve 162.
Is turned on and the spool valve 4 of the C2 control valve 410 is
20 is brought into the engaged state by being placed in the on position, that is, the engaged position, while the low speed stage brake B2
B2 control valve 4 because forward range pressure P _F is not generated
Regardless of the positions of the 12 valve elements 442, they are released.
Therefore, even if the valve element 442 of the B2 control valve 412 is stuck and the valve element 442 cannot be switched to the ON position for releasing the low-speed stage brake B2, the auxiliary transmission 18 is prevented from being locked. .. Moreover, since only the high-speed-stage clutch C2 is engaged, the backward traveling is possible in response to the operation position of the shift lever 142 as required by the driver without the backward traveling being impossible due to the slip of the one-way clutch 102. Becomes

Incidentally, the valve operating elements P 442 and 420 of the B2 control valve 412 and the C2 control valve 410, for example, the engagement operating oil pressure P _bc generated regardless of the operation of the shift lever 142, is applied to the low speed brake B2 and the high speed stage. When the engagement control of the low-speed stage brake B2 and the high-speed stage clutch C2 is performed by switching between the state in which the action on the stage clutch C2 is allowed and the state in which the action is prohibited, the upper stage of FIG. as shown in, the fixation of the valve member 442 of the B2 control valve 412, when becomes impossible to switch the valve member 442 to the side to release the low speed stage brake B2 is the engagement hydraulic pressure P _bc The brake B2 for the low speed stage remains in the state of being applied, and it becomes impossible to switch the brake B2 for the low speed stage to the released state. Therefore, when the shift lever 142 is switched to the R range, the high speed gear clutch C2 is also engaged, the auxiliary transmission 18 is locked, and the vehicle cannot reverse.

In the above device, as shown in the lower part of FIG. 17, the sixth solenoid valve 162 is disconnected or short-circuited while the shift lever 142 is being operated to the R range, so that the electronic control device 132 operates. Contrary to the switching command signal, B
Even when the 2 control valve 412 is located on the side where the low speed gear B2 is engaged, the low speed gear B
Since the clutch 2 is engaged and the one-way clutch 102 slips, it is impossible to reverse the vehicle in the R range. On the other hand, in this embodiment, when the low-speed stage brake B2 is in the released state, C is associated with this.
Since the oil chambers 424 and 426 of the second control valve 410 are both set to the atmospheric pressure and the valve element 420 is preferentially positioned in the ON position regardless of the operating position of the sixth solenoid valve 162,
The high speed gear clutch C2 is engaged. For this reason,
As shown in the lower part of FIG. 16, in the R range, the sixth
Even if the solenoid valve 162 cannot be turned on due to the disconnection, the one-way clutch 102 is prevented from slipping and the vehicle can travel backward as requested by the driver.

Further, in the present embodiment, the low range brake B2 is engaged by the action of the forward range pressure P _F. Therefore, in the N range or the R range, the sixth solenoid valve 162 or the B2 control valve 4 as described above is used.
In order to prohibit the low speed gear brake B2 from being brought into the engaged state against the command of the electronic control unit 132 due to a failure of 12 or the like, in such a failure, the engagement hydraulic pressure to the low speed gear clutch B2 is changed. There is no need to provide a dedicated switching valve that prohibits supply. Therefore, the hydraulic control circuit 170 is more easily configured than when a switching valve is newly provided.

Although one embodiment of the present invention has been described in detail with reference to the drawings, the present invention can be implemented in other modes.

For example, in the power transmission device of the above-described embodiment, the sixth solenoid valve 162 is configured to output the signal pressure P _sol6 in the ON state, but is configured to output the hydraulic pressure in the OFF state. May be. In such a case, the switching command signal supplied from the electronic control unit 132 to the sixth solenoid valve 162 is turned on / off in the opposite direction.

Further, in the above-described embodiment, the auxiliary transmission 18 is provided at the rear stage of the CVT 16, but the present invention is also applied to the power transmission device of the type provided at the front stage of the CVT 16.

In the above embodiment, the CVT (belt type continuously variable transmission) 16 has been described. However, a so-called traction type in which power is transmitted through a roller sandwiched between a pair of cones. It may be a continuously variable transmission.

Further, although the auxiliary transmission 18 is provided with two forward gears in the above embodiment, it may be provided with three or more gear stages.

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

[Brief description of drawings]

FIG. 1 is a skeleton view of a vehicle power transmission device to which the embodiment of FIG. 2 is applied.

FIG. 2 is a block diagram illustrating a configuration of a control device according to an embodiment of the present invention.

FIG. 3 is a chart for explaining a relationship between an operation position of a shift lever and a gear in the power transmission device of FIG.

FIG. 4 is a part of a hydraulic circuit diagram showing the configuration of the hydraulic control device of FIG.

5 is a part of a hydraulic circuit diagram showing the configuration of the hydraulic control device of FIG.

FIG. 6 is a part of a hydraulic circuit diagram showing the configuration of the hydraulic control device of FIG.

FIG. 7 is a part of a hydraulic circuit diagram showing the configuration of the hydraulic control device of FIG.

FIG. 8 is a diagram showing a relationship between a control deviation ΔN _in and a shift mode _in a normal feedback control of the continuously variable transmission of FIG.

9 is a time chart for explaining the states of B2 pressure and C2 pressure when operating the R range and the N range in the hydraulic circuit of FIG. 7, respectively.

10 is a time chart for explaining changes in C1 pressure, B2 pressure, and C2 pressure immediately after an operation from the N range to the D range in the hydraulic circuit diagram of FIG. 7. FIG.

FIG. 11 is a shift diagram for switching the gear stage of the auxiliary transmission of FIG.

FIG. 12 is a time chart for explaining changes in B2 pressure and C2 pressure immediately after the sixth solenoid valve is switched from the off state to the on state in the traveling state in the D range in the hydraulic circuit diagram of FIG. 7. ..

13 is a time chart for explaining changes in B2 pressure and C2 pressure immediately after the sixth solenoid valve is switched from the on state to the off state in the traveling state in the D range in the hydraulic circuit diagram of FIG. 7. FIG. ..

FIG. 14 is a diagram showing the hydraulic circuit of FIG.
6 is a time chart for explaining changes in C1 pressure, B2 pressure, and C2 pressure when the accelerator pedal is depressed during the squat control period immediately after the range is operated.

FIG. 15 is a diagram showing the hydraulic circuit diagram of FIG.
It is a time chart which respectively explains change of C1 pressure, B1 pressure, B2 pressure, and C2 pressure immediately after operating to a range.

FIG. 16 is a view showing a sub-transmission when the B2 control valve is in a stuck state on the off side or in a state in which the sixth solenoid valve cannot be switched to the on position during the R range operation of the shift lever in the hydraulic control device of FIG. It is a chart explaining a gear stage and a state of a vehicle together.

FIG. 17 is a diagram showing a hydraulic control device of a type in which an engagement operating oil pressure generated regardless of an operation of a shift lever is applied as an engagement operating oil pressure of a low speed gear brake B2.
It is a chart corresponding to.

[Explanation of symbols]

14 forward / reverse switching device 16 belt type continuously variable transmission 18 auxiliary transmission C1 forward clutch (hydraulic friction engagement device for forward movement) B1 reverse brake (hydraulic friction engagement device for backward movement) C2 clutch for high speed (hydraulic type) High speed gear friction engagement device) B2 Low speed gear brake (hydraulic low speed gear friction engagement device) 132 Electronic control device 142 Shift lever 162 Sixth solenoid valve (electromagnetic signal pressure generation valve) 410 C2 control valve (high speed Stage control valve) 412 B2 control valve (low speed stage control valve) 420 C2 control valve valve 442 B2 control valve valve

Claims (1)

[Claims] 1. A forward / rearward travel switching device whose rotation direction is switched by a hydraulic forward friction engagement device and a hydraulic reverse friction engagement device that operate in association with the operating range of a shift lever, and a hydraulic low speed stage. From the low speed gear stage established by the engagement of the friction engagement device and the one-way clutch in series therewith, the engagement of the friction engagement device for the hydraulic high speed stage and the friction engagement device for the hydraulic low speed stage or the one-way clutch In a continuously variable transmission for a vehicle, which is independently provided with a sub-transmission that is switched to a high-speed gear stage that is established by releasing the hydraulic high-speed gear when the shift lever is operated to a reverse range. A hydraulic control device of a type in which a friction engagement device for a vehicle is brought into an engaged state, the electromagnetic signal pressure generating valve generating a signal pressure in response to a switching command signal from an electronic control device; On the basis of the above, switching between two positions, that is, a position at which the engagement hydraulic pressure generated regardless of the operation of the shift lever is applied to the hydraulic high-speed friction engagement device and a position at which the operation is prohibited, are switched. A high speed control valve for controlling the engagement state of the hydraulic high speed friction engagement device by switching the valve, and based on the signal pressure, the shift lever moves to the forward range. A position where a forward range pressure generated by being operated is applied to the hydraulic low-speed friction engagement device;
And a low speed control valve for controlling the engagement state of the hydraulic low speed friction engagement device by switching the valve. A hydraulic control device for a continuously variable transmission for a vehicle, comprising: