JPH0510428A - Controller for vehicular continuously variable transmission - Google Patents

Abstract

PURPOSE:To smoothen the gear ratio change of a continuously variable transmission body by forming the controller of a vehicular continuously variable transmission provided with an auxiliary transmission in such a way as to determine the target gear ratio of the continuously variable transmission body by the gear ratio of the auxiliary transmission after the change of the gear stage upon judging the start of gear stage switching operation of the auxiliary transmission. CONSTITUTION:When a shift judging means judges the start of gear stage switching operation of an auxiliary transmission, a target gear ratio determining means is actuated by the judgment signal. The target gear ratio determining means determines the target gear ratio of a continuously variable transmission body in order to obtain the target input shaft rotating speed at that time, on the basis of the gear ratio after the switching of the auxiliary transmission. A gear ratio control means then controls the gear ratio of the continuously variable transmission by this target gear ratio during the switching operation period of the auxiliary transmission.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control apparatus for a continuously variable transmission for a vehicle having an auxiliary transmission that can be switched to a plurality of forward gears.

[0002]

2. Description of the Related Art A continuously variable transmission for a vehicle uses, for example, a gear ratio and a throttle valve opening of a continuously variable transmission body in order to increase a driving force at the time of starting or to expand a gear shift range. Some have an auxiliary transmission that can be switched between a low speed gear and a high speed gear having a lower gear ratio. For example, the one described in JP-A-61-241561 is that. Then, in such a continuously variable transmission control device, for example, based on the vehicle speed and the throttle valve opening from a relationship that is obtained in advance so that the engine operates along an optimum curve that obtains fuel efficiency and drivability of the vehicle. The target input shaft rotation speed is determined, and the gear ratio of the continuously variable transmission body is feedback-adjusted so that the actual input shaft rotation speed of the continuously variable transmission matches the target input shaft rotation speed. The forward gear of the auxiliary transmission is switched based on the state.

[0003]

However, in the conventional control device for a continuously variable transmission equipped with an auxiliary transmission, the target input shaft rotation speed is maintained even during the gear shift operation period of the auxiliary transmission while the vehicle is running. Since the gear ratio of the continuously variable transmission main body is feedback-controlled so as to be obtained, the process of switching the gear stage of the auxiliary transmission is affected by the change in the input shaft rotation speed due to the gear shifting process. As a result, the gear ratio of the continuously variable transmission main body changes curvilinearly toward a predetermined value corresponding to the gear ratio of the sub-transmission after the shift, which causes the driver to feel uncomfortable. For example, when a command to switch the low-speed gear stage of the auxiliary transmission to the high-speed gear stage is issued in connection with the accelerator pedal being operated so that the throttle valve opening becomes sharply small while the vehicle is traveling,
The gear ratio of the auxiliary transmission is changed from the value up to that time to a value smaller than that during the predetermined gear shift operation period by the switching operation by the hydraulic actuator, while at the beginning of the gear shift operation period, the throttle valve is opened. Since the target input shaft rotation speed is rapidly determined to be a low value in relation to the decrease in the opening degree, the actual input shaft rotation speed is changed rapidly after following the target input shaft rotation speed.
After passing through the target input shaft rotation speed, it is changed in the opposite direction again toward the target input shaft rotation speed. For this reason, the gear ratio of the continuously variable transmission main body is once lowered and reaches the predetermined value so that an undershoot-like curve is formed even if the change is not required.

The present invention has been made in view of the above circumstances, and an object of the present invention is to drive an engine output by providing an auxiliary transmission that can be selectively switched to a plurality of forward gear stages. It is an object of the present invention to provide a control device that smoothes a change in the gear ratio of a continuously variable transmission body that occurs in association with switching of a forward gear of an auxiliary transmission in a vehicle continuously variable transmission that transmits to wheels.

[0005]

The gist of the present invention for attaining the above object is to provide a sub-shift which can be selectively switched to a plurality of forward gear stages, as shown in the claim correspondence diagram of FIG. Of a continuously variable transmission for a vehicle that has an engine and transmits the output of the engine to the drive wheels, so that the target input shaft rotation speed determined based on the running state of the vehicle is realized. A control device of a type for adjusting a ratio, comprising: (a) shift determination means for determining that switching operation of a gear stage of the auxiliary transmission is started, and (b) the auxiliary transmission by the shift determination means. If it is determined that the gear shift operation has started, the target gear ratio of the continuously variable transmission main body for obtaining the target input shaft rotation speed at that time is set to the gear shift of the auxiliary transmission after the gear shift. Target gear ratio determining means for determining based on the ratio In (c) the switching operation period of the sub-transmission is the transmission ratio of the transmission main body and a transmission ratio control means for the target gear ratio determined by the target speed ratio determining means to include.

[0006]

In this way, when the shift determination means determines that the gear shift operation of the auxiliary transmission has started, the target gear ratio determination means determines the target input shaft rotation speed at that time. The target gear ratio of the continuously variable transmission main body for obtaining the above is determined based on the gear ratio of the auxiliary transmission after the switching, and during the switching operation period of the auxiliary transmission, the gear ratio control means changes the gear ratio of the transmission main body. The ratio is the target speed ratio determined by the target speed ratio determining means.

[0007]

As described above, during the switching operation period of the auxiliary transmission, the gear ratio control means sets the gear ratio of the transmission main body to the target gear ratio determined by the target gear ratio determining means. The gear ratio of the transmission main body does not form an undershoot-like curve during the gear shift period of the sub-transmission, but linearly and smoothly toward the gear ratio determined by the target gear ratio determining means. Since it changes, it is preferable that the driver's feeling of discomfort is eliminated.

[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. 2 is a skeleton diagram of an FF vehicle transverse transaxle to which a control device according to an embodiment of the present invention is applied, and FIG. 3 is a block diagram showing a configuration example of the control device. In FIG. 2, the power of the engine 10 includes a fluid coupling 12 with a lockup 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. Fluid coupling with lockup clutch 12, forward / reverse switching device 1
4, belt type continuously variable transmission (hereinafter referred to as CVT) 16,
The sub transmission 18, the reduction gear device 20, and the differential gear device 22 are housed in the transaxle housing 64 to form a continuously variable transmission in a broad sense.
The VT 16 corresponds to the continuously variable transmission body.

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. 3, 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. 4 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.

The hydraulic control circuit 170 of FIG. 3 is constructed as shown in FIG. 5, FIG. 6, FIG. 7, and FIG. 5 to 8, 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]

In the primary pressure regulating valve 180, the hydraulic pressure P _in in the primary side hydraulic actuator 86 is the tension control pressure P.
If it is higher than the _belt (P _belt = the hydraulic pressure P _out in the secondary hydraulic actuator 88 in the steady state), the first plunger 196 and the second plunger 198 are separated from each other and the primary hydraulic actuator hydraulic pressure is increased. thrust by P _in acts in the closing direction of the spool 190, but if the primary side hydraulic actuator in the hydraulic P _in is less than the tension control pressure P _belt, the second plunger 1 to the first plunger 196
Since 98 abuts, the thrust force by the tension control pressure P _belt acting on the end surface of the second plunger 198 acts in the valve closing direction of the spool valve element 190. That is, the thrust force based on the higher one of the hydraulic pressure P _{in in the} primary side hydraulic actuator and the tension control pressure P _belt is the spool valve 1
It is operated in the valve closing direction of 90. As a result, the primary line hydraulic pressure P _r1 is adjusted to a value proportional to the higher hydraulic pressure of the primary hydraulic actuator internal hydraulic pressure P _in and the tension control pressure P _belt, and the power loss for generating the hydraulic pressure is reduced. Be as small 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]

[Equation 2]

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. 9 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 quickly drained through the check valve 387, the reverse inhibit valve 372, and the manual valve 310, and the reverse range is set. The pressure P _R is 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 atmospheric pressure, the spool valve element 420 is moved to the non-engagement side position (off-side position in FIG. 8). After being 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, as shown in FIG. 4, the sixth solenoid valve 162 is held in the ON state and the C2 control is performed. Since the signal pressure P _sol6 in the oil chamber 424 of the valve 410 is applied, the spool valve element 420 of the C2 control valve 410 is moved to the engagement position (on position in FIG. 8) 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 brought into a direct connection state. The 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. 10 shows the high-speed hydraulic actuator 10 when the shift lever 142 is operated to the R range or the N range as described above.
6 shows the hydraulic pressure (C2 pressure) and the hydraulic pressure of the low speed hydraulic actuator 108 (B2 pressure). When the shift lever 142 is operated to the R range, the R range pressure P _R is set to the oil chamber 31 of the engagement actuation hydraulic pressure regulating valve 226 so that the engagement force corresponding to the transmission torque of the reverse gear is obtained.
Since the engagement operating pressure _Pbc is increased by a predetermined pressure by being acted on by 2, the B2 pressure is higher than the C2 pressure.

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. Control is started, and during the squat control, as shown in FIG.
The high speed clutch C2 and the low speed brake B2 are maintained in the same state as the N range until then. That is,
The sixth state of the sixth solenoid valve 162 is kept on by the electronic control unit 132, the spool valve element 420 of the C2 control valve 410 is moved to the engagement position (on position in FIG. 8), and the high speed clutch C2 is continuously operated. Is engaged with. In this state, the forward range pressure P _F is output from the manual valve 310 to engage the forward clutch C1 in the forward hydraulic actuator 42 and the oil chamber 4 of the B2 control valve 412.
The hydraulic oil is supplied into the cylinder 46, and the hydraulic pressure (C1 pressure) in the forward hydraulic actuator 42 rises slowly due to the action of the throttles 374, 376 and the accumulator 402, but until it rises, the B2 control valve 41
The signal pressure P _sol6 is _applied in the second oil chamber 448 so that the spool valve element 442 is located at the non-engagement position (on position in FIG. 8), and the low speed hydraulic pressure for activating the low speed brake B2. Since the state in which the actuator 108 is drained is maintained, in the auxiliary transmission 18, only the high speed clutch C2 is engaged.

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. 8).
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 disengagement position (OFF position in FIG. 8) against the biasing force of the spring 422, and the high speed 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. 11
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 operation of the shift lever 142 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. 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. 11, 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 Unexamined Patent Publication No. 61-241561.
As described in the publication, when the running state of the vehicle is within the switching permission region from the low speed gear stage to the high speed gear stage of 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. 8). Therefore, the engagement operating oil pressure P _bc passes through the throttle 415 and the hydraulic actuator 1 for the high speed stage
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. 13 shows changes in the C2 pressure and the B2 pressure when the sixth solenoid 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 kickdown operation is performed in which the accelerator pedal (not shown) is greatly depressed while the vehicle is traveling in the high speed gear position, 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. 8) 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, whereby the high speed gear clutch C2 is released and the low gear speed is established. Further, as described in Japanese Patent Application Laid-Open No. 61-241561, when the actual gear ratio γ _cvt falls below a predetermined value γ _o while the vehicle is traveling, the same as above. The downshift of the auxiliary transmission 18 is executed. FIG. 14 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.

Further, 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 biasing force of the spring 422 to the non-engagement position (OFF position in FIG. 8), 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. Figure 15
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. 16, 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 indicated 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 of setting the diaphragm 386, the accumulator 404, etc. to loosen the engagement of 1 is taken. 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 present hydraulic control circuit 170, the upshift or downshift of the auxiliary transmission 18 is realized by engaging or releasing only the high speed gear clutch C2 as described above, and therefore, the high speed gear clutch is performed. Despite the variation in the engagement operation time and the disengagement operation time of C2, smooth execution is possible without requiring complicated timing control. Further, as described above, since the low-speed hydraulic actuator 108 is operated based on the forward range pressure P _F output from the manual valve 310, when the shift lever 142 is not operated to the R range. Since the engagement of the low speed gear brake B2 is prevented regardless of the operating state of the B2 control valve 412, the auxiliary transmission 18 is prevented from being locked due to the failure of the B2 control valve 412 during the reverse travel of the vehicle, for example. ..

Next, the clutch oil pressure P _cl in the clutch pressure oil passage 182 is adjusted by the clutch pressure adjusting valve 450 according to the throttle pressure P _th . The clutch oil pressure P _cl is related to the engagement pressure of the lockup clutch 38, but the hydraulic oil in the clutch pressure oil passage 182 passes through the throttle 453 to the sliding portion of the transmission belt 76, the bearing portion, and the planetary gear. Meshing part, differential gear unit 2
It is pumped to 2 etc. as lubricating oil. Further, the hydraulic oil that is caused to flow out from the relief port 455 of the clutch pressure regulating valve 450 is also pressure-fed as lubricating oil. The clutch pressure regulating valve 450 includes a spool valve element 452 for allowing the hydraulic oil in the clutch pressure oil passage 182 to escape to the return oil passage 176, and a spring 454 for urging the spool valve element 452 in the valve closing direction. The plunger 456 that receives the throttle pressure P _th and transmits the thrust in the valve closing direction based on the throttle pressure P _th to the spool valve element 452, and the clutch hydraulic pressure P as feedback pressure to apply the thrust in the valve opening direction to the spool valve element 452.
and an oil chamber 458 for receiving _cl .

A lockup relay valve 460 which is switched by a third solenoid valve 156 and a fourth solenoid valve 15 for controlling engagement and disengagement of the lockup clutch 38.
A lockup control valve 462 that is switched by 8 is provided. The lockup relay valve 460 receives the clutch oil pressure P _cl via the drain port 464 and the check valve 466.
Is supplied to the first port 468, the second port 470, the third port 472, the fourth port 474, and the fifth port 47.
6. Drain port 478, spool valve 480 for switching between those ports, and spool valve 4
And a spring 484 that biases 80 toward the oil chamber 482. Therefore, the signal pressure P from the third solenoid valve 156 is
_{When sol3} is not supplied to the oil chamber 482, the spool valve 480 is positioned on the oil chamber 482 side, so the first port 468 and the second port 470, the third port 472 and the fourth port 474, and the fifth port 476. And drain port 47
8 are communicated with each other. On the contrary, the third solenoid valve 15
In the state where the signal pressure P _sol3 from 6 is supplied to the oil chamber 482, the spool valve element 480 is positioned on the oil chamber 482 side, so that the drain port 464, the second port 470, and the first port
The port 468 and the third port 472 are communicated with each other, and the fourth port 474 and the fifth port 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 Application Laid-Open No. 61-241561 or Japanese Patent Application 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 speed gear stage, the sixth solenoid valve 162 is turned on, and if it is the low speed gear stage, the sixth solenoid valve is turned on. 162 is turned off.

Next, using the flowchart of FIG. 17, C
The main part of the gear ratio control of the VT 16 will be described in more detail. In step S1 of the figure, it is determined whether or not the content of the flag F _o indicating that the shift operation period of the auxiliary transmission 18 is in progress is "1". Normally, the content of the flag F _o is “0”.
Therefore, since the determination in step S1 is negative, it is determined in the following step S2 whether the shift from the low speed gear stage to the high speed gear stage of the sub transmission 18 is commanded by the shift stage switching control of the sub transmission 18. Is determined. This step S2 corresponds to shift determining means for determining that the switching operation of the gear stage of the auxiliary transmission 18 has started. Normally, the judgment in step S2 is denied, so that the normal feedback control routine of the CVT 16 is executed in step S4. In this ordinary feedback control, for example, Japanese Patent Laid-Open No. 62-137239.
As described in the publication, the engine 1 is run along an optimum curve obtained in advance to obtain fuel efficiency and drivability.
From the relationship, the target input shaft rotation speed N _in ^T is determined based on the actual throttle valve opening θ _th and the vehicle speed SPD so that 0 operates, and the target input shaft rotation speed N _in ^T and the actual input shaft Deviation from rotational speed N _in ΔN _in (= N _in ^T −
The first electromagnetic valve 152 and the second electromagnetic valve 154 are driven to adjust the gear ratio γ _CVT so that (N _in ) is eliminated.

[0054] While the above control cycle is repeated, for example, predetermined vehicle speed SPD _A as shown in FIG. 18
If the shift of the auxiliary transmission 18 from the low-speed gear stage to the high-speed gear stage is instructed by the gear stage shift control being caused by the throttle valve opening degree _θth being rapidly reduced during traveling, the determination in step S2 above. Is affirmed,
In the subsequent step S3, the content of the flag F _o is set to "1". Therefore, after the determination in step S1 of the next control cycle is affirmed, in step S5 the auxiliary transmission 1
It is determined whether or not the switching operation from the low speed gear stage 8 to the high speed gear stage 8 has been completed. After the determination in step S2 is affirmative, the operation for switching the sub transmission 18 from the low speed gear stage to the high speed gear stage is started by the shift stage switching control of the sub transmission 18, as shown in FIG. , C2 pressure starts to increase, and the rotation speed N _out2 of the second output shaft 96 becomes C
It approaches toward the rotation speed of the output shaft 70 of the VT 16.
The determination in step S5 is based on, for example, a signal representing the output shaft rotation speed N _out from the output shaft rotation sensor 138 and a signal representing the vehicle speed SPD from the vehicle speed sensor 140.
Rotation speed N _out2 of the second output shaft 96 and output shaft rotation speed N
It is judged based on the fact that _out matches.

At the beginning of the switching operation period from the low speed gear stage to the high speed gear stage of the auxiliary transmission 18, the determination at the step S5 is denied, so at the subsequent step S6, within the switching operation period. CVT1 to maintain
6 target gear ratio gamma _CVth ^O speed rotating target input shaft immediately after the start of the switching operation period from Equation 3 N _in ^TA (shown in FIG. 18), the gear ratio gamma _H of the high-speed gear stage of the auxiliary transmission 18 (=
1) and the rotation speed N _out2 of the second output shaft 96. In step S6, the target gear ratio γ _CVTH ^O of the CVT 16 for obtaining the target input shaft rotation speed N _in ^TA at the start of the gear shift operation of the auxiliary transmission 18 is changed to the gear change of the auxiliary transmission 18 after the gear change. It corresponds to a target gear ratio determining means that determines based on the ratio. As is clear from Equation 3, the target gear ratio γ _CVTH ^O is for _{setting the} input shaft rotation speed N _in to the target input shaft rotation speed N _in ^TA after the completion of the switching operation of the auxiliary transmission 18. The second output shaft 9
The rotation speed N _{out2 of} 6 is the vehicle speed S from the vehicle speed sensor 140.
It is calculated based on the signal representing PD _A.

[0056]

[Equation 3]

Then, in step S7, the magnitude of the actual gear ratio γ _CVT of the _CVT 16 during the switching operation is compared with the target gear ratio γ _CVTH ^O , and the actual gear ratio γ _CVT is calculated as the target gear ratio γ _CVTH. If greater than ^O ,
Is the step S4 is performed to upshift, when the actual gear ratio gamma _CVT and the target speed ratio gamma _CVth ^O are equal, step S8 in order to maintain the speed ratio
9 is selected and the actual gear ratio γ _CVT is smaller than the target gear ratio γ _CVTH ^O , the step S9 for downshifting is performed, for example, as shown in FIG. The intermediate deceleration shift mode indicated by (b) or the rapid deceleration shift mode indicated by (a) is selected. The normal feedback control of step S4 is performed during the switching operation period of the auxiliary transmission 18.
For example, as shown in FIG. 18, N _in before the accelerator release operation is performed.
^The upshift operation is in progress in which the actual input shaft rotational speed N _in follows the target input shaft rotational speed reduced from ^TF to N _in ^TA after the accelerator return operation. Therefore, steps S7, S4, S8, and S9 correspond to the gear ratio control means that sets the gear ratio γ _CVT of the _CVT 16 to the target gear ratio γ _CVTH ^O by feedback control during the switching operation period of the auxiliary transmission 18. ing.

When the switching operation of the auxiliary transmission 18 is completed while the above steps are repeatedly executed, the determination at step S5 is positive, so the content of the flag F ₀ is cleared to "0" at step S10. After that, the normal feedback control of the step S4 is executed.

According to the present embodiment, when it is determined in step S2 corresponding to the shift determination means that the gear shift operation of the auxiliary transmission 18 has been started, it corresponds to the target gear ratio determination means. In step S6, the target gear ratio γ _CVTH ^{O of the} CVT 16 for obtaining the target input shaft rotation speed N _in ^TA at the time of the switching operation is the gear ratio γ of the auxiliary transmission 18 after the change.
During the switching operation period of the auxiliary transmission 18, which is determined based on _H , steps S7 and S corresponding to the gear ratio control means are performed.
The gear ratio γ _{CVT of the CVT} 16 is set to the target gear ratio γ _CVTH ^O by 4, S8 and S9. In this way, the auxiliary transmission 1
During 8 switching operation period, since the gear ratio gamma _CVT of CVT16 is the target gear ratio gamma _CVth ^O, the gear ratio gamma _CVT of CVT16 is during inter-switching period of the gear position of the subtransmission machine 18
_Does not form an undershoot-like curve and changes smoothly toward the target gear ratio γ _CVTH ^O , so that it is possible to suitably eliminate the driver's discomfort.

That is, as shown in FIG. 19, when the throttle valve opening θ _th changes in association with the accelerator pedal return operation, the target input shaft rotation speed N changes in association with the change value of the throttle valve opening θ _{th. in} ^T not only is changed, the sub transmission 18 is switched from the low gear to a high-speed gear according to the conditions shown in FIG. 12. In such a case, the CVT is changed according to the change value of the throttle valve opening θ _th.
The change state of the gear ratio γ _CVT of 16 is different. For example, when changing from the point of FIG. 19 to the point, the gear ratio γ _{CVT of the CVT} 16 is increased as shown in FIG. 20, but when changing from the point of FIG. 19 to the point of FIG.
If the target gear ratio γ _CVT of the _CVT 16 does not change and changes from point to point in FIG.
As indicated by 0, the gear ratio γ _{CVT of the CVT} 16 is reduced. The target input shaft rotation speed N _in ^T is shown _in FIG.
As shown by the solid line in FIG. 20, in the conventional control device, the undershoot _in which the actual input shaft shaft rotational speed N _in once falls and then rises due to the effect of the feedback control. The change ratio γ _{CVT of the CVT} 16 also changes along the undershoot curve, which gives the driver a feeling of strangeness. On the other hand, in this embodiment, during the switching operation period of the auxiliary transmission 18, the gear ratio γ of the CVT 16 is changed.
Since _CVT is the target gear ratio gamma _CVth ^O, as shown in dot-dash line in FIG. 20, since the smoothly varying toward the target ratio gear ratio gamma _CVth ^O, preferable to feel uncomfortable to the driver Will be resolved.

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 above-described embodiment, the auxiliary transmission 18
During the switching operation period of step S7, S4, S8, S9
The gear ratio gamma _CVT of CVT16 by feedback control by has been the target gear ratio gamma _CVth ^O, but is the gear ratio of CVT16 by the open-loop control gamma _CVT may be used as the target gear ratio gamma _CVth ^O.

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. Further, the auxiliary transmission 18 may be provided at the same place as the forward / reverse switching mechanism 14 without any problem.

Further, in the feedback control of the CVT 16 of the above embodiment, the target input shaft rotation speed N _in ^T is used, but the target target gear ratio γ _CVT ^T (= N) of the actual gear ratio γ _CVT is used. _in ^T / N _out ) may be used.

Although the CVT (belt type continuously variable transmission) 16 has been described in the above-mentioned embodiment, 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 has two forward gears in the above embodiment, it may have three or more gears.

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

[Brief description of drawings]

FIG. 1 is a diagram corresponding to a claim of the present invention.

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

FIG. 3 is a block diagram illustrating a configuration of a control device according to an embodiment of the present invention.

FIG. 4 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.

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

FIG. 8 is a part of a hydraulic circuit diagram showing the configuration of the hydraulic control device of FIG.

9 is a diagram showing a relationship between a control deviation ΔN _in and a shift mode _in normal feedback control of the continuously variable transmission shown in FIG. 2.

FIG. 10 is a time chart for explaining states of B2 pressure and C2 pressure when operating the R range and the N range in the hydraulic circuit of FIG. 8, respectively.

FIG. 11 is a time chart for explaining changes in C1 pressure, B2 pressure, and C2 pressure immediately after the operation from the N range to the D range in the hydraulic circuit diagram of FIG.

FIG. 12 is a shift diagram for switching a gear stage of the auxiliary transmission of FIG.

FIG. 13 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. 8. ..

FIG. 14 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. 8. ..

FIG. 15 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. 16 is a 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. 17 is a flowchart illustrating a control operation of the control device of FIG.

FIG. 18 is a diagram illustrating a relationship between a change in throttle valve opening degree θ _th related to an accelerator return operation and a corresponding target input shaft rotation speed N _in ^T _in the embodiment of FIG. 17.

FIG. 19 is a diagram illustrating a plurality of types of accelerator return operations in the embodiment of FIG.

20 is a time chart illustrating an operation obtained as a result of the control shown in the flowchart of FIG.

[Explanation of symbols]

16 belt type continuously variable transmission, 18 auxiliary transmission: continuously variable transmission step S2 shift determination means step S6 target speed ratio determination means steps S7, S4, S8, S9 speed ratio control means

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[Procedure amendment]

[Submission date] August 13, 1991

[Procedure Amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0060

[Correction method] Change

[Correction content]

That is, as shown in FIG.
Throttle valve opening θ_thStrange
The throttle valve opening θ_thRelated to the change value of
Target input shaft rotation speed N_in ^TCan only be changed
In accordance with the conditions shown in FIG. 12, the auxiliary transmission 18 has a low speed.
The gear stage is switched to the high speed gear stage. Such a place
Throttle valve opening θ_thCVT depending on the change value of
16 gear ratio γ_CVTThe change state of is different. For example, the figure
From 19 points If it changes to a point,
As shown, the gear ratio γ of the CVT 16_CVTIs increased
But in Figure 19 From the point If it changes to a point,
As shown in, the target gear ratio γ of the CVT 16_CVTIs change
Without, in FIG. When changing from point to point, see Figure 2.
As shown in 0, the gear ratio γ of the CVT 16_CVTIs reduced
Sent. Then, the target input shaft rotation speed N_in ^TFigure 20
As shown in the figure, the conventional control system
In the position, the feedback control action of FIG.
As shown by the solid line, the actual input shaft shaft rotation speed N_inIs once below
Along the undershoot-like curve that rises and then descends
Change, the gear ratio γ of the CVT 16_CVTAs well as Andersi
The driver feels uncomfortable because it changes along a curve.
Was given. On the other hand, in this embodiment, the sub
During the switching operation period of the transmission 18, the gear ratio γ of the CVT 16 is changed.
_CVTIs the target gear ratio γ_CVTH ^OTherefore, one point in Fig. 20
Eye, as shown by the dashed lineChangeSpeed ratio γ_CVTH ^OSlipped towards
Can change the driver's sense of incongruity.
It is solved appropriately.

[Procedure Amendment 2]

[Document name to be corrected] Drawing

[Name of item to be corrected] Fig. 20

[Correction method] Change

[Correction content]

FIG. 20

Claims (1)

Claim: What is claimed is: 1. A vehicle continuously variable transmission that has an auxiliary transmission that is selectively switched between a plurality of forward gears and that transmits the output of the engine to driving wheels. A control device of a type that adjusts a gear ratio of the continuously variable transmission so that a target input shaft rotation speed determined based on a state is realized, and a switching operation of a gear stage of the auxiliary transmission is started. If it is determined by the shift determining means that the gear shift operation of the auxiliary transmission has started, the shift determining means determines whether or not the target input shaft rotation speed at that time is obtained. Target speed ratio determining means for determining the target speed ratio of the main stage transmission main body based on the speed ratio of the auxiliary transmission after the gear shift, and the speed ratio of the main transmission unit during the switching operation period of the auxiliary transmission. Is determined by the target speed ratio determining means. And a transmission ratio control means for the target gear ratio, the control device for a continuously variable transmission for a vehicle, which comprises.