JP2001280476A - Controller for gear ratio infinity step less transmission - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a gear ratio infinity step less transmission having a controller which can inhibit a shock load and precisely prevent an unintentional gear shifting due to a failure, etc., as well when an operator switches into operating mode. SOLUTION: In the gear ratio infinity step less transmission, the controller provides a cam 280 to drive an inhibitor valve 170 in addition to a power circulating mode clutch 99 and a direct connecting mode clutch 10. Furthermore, the controller can drive the inhibitor valve 170 so as to supply the hydraulic pressure to both the power circulating mode clutch 99 and the direct connecting mode clutch 10 in the operating mode switching range. However, if the switch is positioned out of the operating mode switching range, the hydraulic pressure is supplied either the power circulating mode clutch 99 or the direct connecting mode clutch 10 according to the operating conditions by the operation of the inhibitor valve 170 driven by the cam 280.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement in a control device for a continuously variable transmission with an infinite transmission ratio employed in a vehicle or the like.

[0002]

2. Description of the Related Art A belt-type or toroidal-type continuously variable transmission is conventionally known as a vehicle transmission. In order to further expand the shift range of such a continuously variable transmission, a continuously variable transmission is known. An infinitely variable speed ratio continuously variable transmission is known which combines a constant transmission and a planetary gear mechanism to control the speed ratio to infinity, for example, Japanese Patent Application Laid-Open No. H10-325559.

[0003] This is a half toroidal type continuously variable transmission capable of continuously changing the speed ratio and a constant speed transmission (reduction gear) on a unit input shaft of an infinitely variable speed ratio continuously variable transmission connected to an engine. ) Are connected in parallel, and these output shafts are selectively connected by a planetary gear mechanism. The output shaft of the continuously variable transmission is connected to the sun gear of the planetary gear mechanism, and the output shaft of the constant transmission is used for power circulation. It is connected to the carrier of the planetary gear mechanism via a mode (low mode) clutch. A ring gear meshing with the pinion of the carrier is coupled to the unit output shaft.

[0004] The continuously variable transmission output shaft connected to the sun gear
It is connected to a unit output shaft which is an output shaft of an infinitely variable speed ratio transmission via a direct connection mode (high mode) clutch.

In such a continuously variable transmission with an infinite transmission ratio,
As shown in FIG. 22, while the power circulation mode clutch is engaged and the direct connection mode clutch is released, the unit speed ratio (IVT ratio in the figure) is changed according to the speed ratio difference between the continuously variable transmission and the fixed transmission. (ii) a power circulation mode in which the unit input shaft rotation speed / unit output shaft rotation speed is continuously changed from a negative value to a positive value including infinity (= geared neutral point GNP), and a power circulation mode. There is a direct connection mode in which the clutch is disengaged and the direct connection mode is engaged to perform a speed change control in accordance with the speed ratio (CVT ratio ic in the figure) of the continuously variable transmission. These two operation modes are selectively used. be able to.

[0006] The operation mode is switched between the rotation synchronization point RSP (see FIG. 22) or the rotation synchronization point RS where the IVT ratio ii matches in the power circulation mode and the direct connection mode.
If performed near P, it is possible to switch the engaged state of the power circulation mode clutch and the direct connection mode clutch while suppressing shock.

By the way, in this conventional example, the power circulation mode clutch and the direct connection mode clutch engage and disengage based on independently controlled clutch pressure except when the operation mode is switched. When the unit breaks down or a valve stick occurs, both clutches may be engaged at the same time.

For example, if the direct-coupled mode clutch is engaged due to the above-described failure while traveling in the power circulation mode, the IV
Since the T ratio ii must be a value corresponding to the rotation synchronization point RSP, the CVT ratio ic is forcibly shifted toward the rotation synchronization point RSP as shown by a dashed line in FIG.

Conversely, if the power-circulation mode clutch is engaged due to the above-described failure while traveling in the direct connection mode, the IVT ratio ii must be a value corresponding to the rotation synchronization point RSP as described above. , The CVT ratio ic is forcibly shifted toward the rotation synchronization point RSP, and in any of the operation modes, there is a problem that a shift unintended by the driver occurs.

[0010] Such a rotation synchronization point RSP,
In order to prevent unintended shifting, it is necessary to supply hydraulic pressure to only one of the power circulation mode clutch and the direct connection mode clutch to avoid simultaneous engagement of the two clutches.

[0011]

As described above, in the case where the hydraulic pressure is supplied to only one clutch in order to prevent simultaneous engagement, when switching the operation mode, one clutch must be released. , The other clutch must be engaged, the clutch is released at the rotation synchronization point RSP,
The fastening will be performed sequentially. However, release,
If the fastening is sequentially performed, it becomes difficult to switch the operation mode at the rotation synchronization point RSP. If the actual fastening is performed after the rotation synchronization point RSP, a switching shock occurs and the drivability is reduced. was there.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and has as its object to suppress a shock at the time of switching operation modes while reliably preventing an unintended gear shift due to a failure or the like. I do.

[0013]

According to a first aspect of the present invention, a continuously variable transmission capable of continuously changing a gear ratio and a constant transmission are connected to a unit input shaft, respectively. Speed ratio infinitely variable transmission in which the output shaft of the machine is connected to the unit output shaft via a planetary gear mechanism, a power circulation mode clutch and a direct connection mode clutch, and the power circulation mode clutch and the direct connection mode clutch according to the operation state A control unit for an infinitely variable gear ratio continuously variable transmission, comprising: a clutch control unit that supplies a hydraulic pressure to at least one of the two to control a power circulation mode and a direct connection mode. Operating state determining means for determining whether or not a preset rotation synchronization point or an operation mode switching region set in the vicinity of the rotation synchronization point is provided; And a valve capable of supplying hydraulic pressure to both or one of the direct-coupled mode clutches and, when the determination result is in the operation mode switching region, supplying the hydraulic pressure to both the power circulation mode clutch and the direct-coupled mode clutch. When the valve is driven and the determination result is not in the operation mode switching region, the drive for driving the valve so as to supply hydraulic pressure to only one of the power circulation mode clutch and the direct connection mode clutch in accordance with an operation state. Means.

According to a second aspect of the present invention, in the first aspect, the valve is a hydraulic control valve capable of variably controlling a hydraulic pressure, and switching between a control pressure output from the hydraulic control valve and a line pressure. A driving valve, wherein the driving unit is in the operation mode switching region,
While the switching valve is driven to output the control pressure, when not in the operation mode switching region, the switching valve is driven to output the line pressure.

In a third aspect based on the first aspect, the driving means is a cam responsive to a speed ratio of the continuously variable transmission.

In a fourth aspect based on the second aspect, the cam drives the switching valve near a switching position corresponding to the operation mode switching area.

In a fifth aspect based on the first aspect, the operation mode switching region is such that the speed ratio of the continuously variable transmission is smaller than the rotation synchronization point and is closer to the rotation synchronization point than the geared neutral point. Or the speed ratio between the unit input shaft and the unit output shaft is a predetermined range including the rotation synchronization point.

[0018]

Accordingly, the first aspect of the present invention is to disengage the power-coupled mode clutch and release the direct-coupled mode clutch, thereby achieving unit speed change according to the difference in speed ratio between the continuously variable transmission and the fixed transmission. Ratio (Unit input shaft speed /
A power circulation mode in which the speed of the unit output shaft is continuously controlled from a negative value to a positive value including infinity (= geared neutral point), and a power circulation mode clutch is released, while a direct connection mode clutch is released. In a continuously variable transmission with an infinite gear ratio that selectively uses the direct connection mode in which gear shifting control is performed according to the gear ratio of the continuously variable transmission, when the operating state is in a preset operation mode switching region, By supplying hydraulic pressure to both the power circulation mode clutch and the direct connection mode clutch, it is possible to smoothly switch the clutch to be engaged while suppressing the shock, and to switch the operation mode.

On the other hand, when it is not in the operation mode switching region, the hydraulic pressure is supplied to only one of them according to the operation state. Therefore, for example, a command is issued such that the control unit or the hydraulic circuit breaks down and both clutches are engaged. Even if it occurs, both clutches cannot be engaged at the same time, and even if the above-described failure occurs, unintended shift can be reliably prevented.

According to a second aspect of the present invention, in the operation mode switching range, the engaging force of the power circulation mode clutch or the direct connection mode clutch is smoothly changed by the control pressure from the hydraulic control valve to suppress the shock at the time of engagement. The switching between the power circulation mode and the direct connection mode can be performed while doing so.

On the other hand, when it is not in the operation mode switching region, one clutch according to the operation state is engaged according to the line pressure, and it is possible to reliably maintain either the power circulation mode or the direct connection mode.

In the third aspect of the present invention, the switching valve is driven by a cam that responds to the speed ratio of the continuously variable transmission, thereby eliminating the need for control for switching the valve and controlling the valve according to the operating state. Switching can be performed with high accuracy.

In the fourth invention, the switching valve is driven in the vicinity of the switching position corresponding to the operation mode switching area, so that the valve driving amount is minimized to reduce the size of the valve. Can be promoted.

According to a fifth aspect of the present invention, in the operation mode switching region, the speed ratio of the continuously variable transmission is set to be smaller than the rotation synchronization point and to be closer to the rotation synchronization point than the geared neutral point. Or the speed ratio between the unit input shaft and the unit output shaft is within a predetermined range including the rotation synchronization point, and the first speed ratio is set to the rotation synchronization point side, so that the operation mode Even if unintended simultaneous engagement occurs in the switching region, the change width of the total speed ratio between the direct connection mode and the power circulation mode can be reduced to reduce unintended shift shock.

[0025]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the accompanying drawings.

FIG. 1 shows an example in which a continuously variable transmission having an infinite speed ratio is formed by using a toroidal type continuously variable transmission 2 of a double cavity type constituted by a half toroid.

In FIG. 1, a continuously variable transmission having an infinitely variable transmission ratio is provided with a continuously variable transmission 2 capable of continuously changing the transmission ratio on a unit input shaft 1a connected to a crankshaft (not shown) of an engine. , A fixed transmission 3 (reducer) composed of a gear 3a and a gear 3b are connected in parallel, these output shafts 4 and 3c are arranged on the unit output shaft 6 side and connected by a planetary gear mechanism 5. It was done.

The continuously variable transmission output shaft 4 is coaxially supported with the unit output shaft 6 and is rotatably supported relative thereto, and is connected to the continuously variable transmission 2 via an output sprocket 2a, a chain 4b, and a sprocket 4a. One end of the continuously variable transmission output shaft 4 is connected to the sun gear 5 a of the planetary gear mechanism 5, and the other end is connected to the direct connection mode clutch 10.

The output shaft 3c of the fixed transmission 3 connected to the gear 3b is also supported coaxially with the unit output shaft 6 so as to be rotatable relative to the unit output shaft 6, and is connected to the carrier 5b of the planetary gear mechanism 5 via the power circulation mode clutch 9. The ring gear 5c of the planetary gear mechanism 5, which is connected and meshes with the pinion of the carrier 5b, is connected to the unit output shaft 6 which is the output shaft of the infinitely variable speed ratio transmission.

A transmission output gear 7 is provided on the right side of the unit output shaft 6 in the drawing. The transmission output gear 7 meshes with the final gear 12 of the differential gear 8 and is connected to the differential gear 8. Drive shaft 1
1, the driving force is transmitted at a unit speed ratio ii corresponding to the speed ratio CVT ratio ic of the continuously variable transmission 2.

As shown in FIG. 1, the continuously variable transmission 2 is a double-cavity half-toroidal type in which a power roller 20 is sandwiched and pressed by two sets of input disks 21 and output disks 22, respectively. As shown in FIGS. 3 and 4, the lower end 20 is connected to the hydraulic cylinder 30 and is axially supported by a trunnion 23 that is axially displaceable and rotatable around the axis. At the lower end of the shaft portion 23A of one trunnion 23, the axial displacement amount of the trunnion 23 and the tilt angle φ of the power roller 20 (= rotation angle of the trunnion 23 / actual gear ratio) are transmitted to a shift control valve 246 described later. A precess cam 135 for feedback is provided.

The precess cam 135 has a cam groove or a cam surface 135A having a predetermined inclination in the circumferential direction as shown in FIGS. 3 to 6, and is swingable on the cam groove or the cam surface. One end of the feedback link 38 comes into sliding contact.

The feedback link 38 is, for example, L
And is supported so as to be swingable about a swing shaft 39. One end is in sliding contact with the cam groove or the cam surface, and the other end is engaged with one end of the speed change link 37, so that a trunnion is formed. The rotation amount of the power roller 20, that is, the tilt angle of the power roller 20 and the axial displacement amount are transmitted to one end of the speed change link 37.

As shown in FIG. 4, the speed change link 37 has a spool 24 of the shift control valve 246 at the center thereof.
6S, the other end of the speed change link 37 connected to the feedback link 38 is connected to a step motor 136 (actuator), and the speed change link 37 is driven by the step motor 136 to control the shift control valve 2.
46 (shift control valve) is axially displaced, and the CVT ratio ic is changed by axially displacing the spool 246S of the shift control valve 246 in accordance with the rotation and axial displacement of the trunnion 23.

Here, as shown in FIG. 2, the speed control control unit 80 for controlling the infinitely variable speed ratio continuously variable transmission detects the rotation speed Ni of the unit input shaft 1 (= engine rotation speed Ne). The output from the input shaft speed sensor 81, the output from the continuously variable transmission output shaft speed sensor 82 for detecting the speed No of the continuously variable transmission output shaft 4, and the vehicle speed from the speed Nout of the unit output shaft 6 An output from a vehicle speed sensor 83 for detecting VSP, and a select position POS from an inhibitor switch 85 responsive to a select lever or the like.
Also, the accelerator pedal depression amount APS from the accelerator opening sensor 84 and the like are input. The vehicle speed sensor 83 obtains a value obtained by multiplying the unit output shaft rotation speed Nout by a predetermined constant as the vehicle speed VSP. The select position POS is, for example, a D range as a forward range and an R range as a reverse range. There are a range, an N range as a stop range, and a P range.

The shift control unit 80 processes these detected values as operating conditions, and drives the stepping motor 136 to achieve a unit speed ratio (IVT ratio ii) or a speed ratio e according to the operating conditions. Step transmission 2
Control of the gear ratio (CVT ratio ic), and by driving the direct-coupled clutch solenoid 190 and the power-circulating clutch solenoid 210 in accordance with this operating state, the direct-coupled mode clutch 10 and the power-circulating mode clutch 9 are selectively operated. Tighten, select power circulation mode and direct connection mode,
When the operation mode is switched, both clutches are temporarily engaged simultaneously to smoothly switch the operation mode.

Next, the hydraulic circuits shown in FIGS. 4 to 6 will be described for each element.

<1. Line pressure and lubrication pressure control system> The discharge port 110p of the oil pump is guided to the line pressure port 100p of the pressure regulator valve 100 via the line pressure circuit 101, while the signal pressure Psigpl from the line pressure solenoid 90 is supplied to the pressure regulator valve. 100 port 100f.

The resultant force of the signal pressure Psigpl, the urging force of the spring 100b, and the discharge port 110p
The spool 100a is displaced so that the hydraulic pressure from the line is balanced, and the line pressure PL of the line pressure circuit 101 connected to the line pressure port 100p is controlled to a predetermined value.

The line pressure solenoid 90 is controlled by the transmission control unit 80 to adjust the signal pressure using the pilot pressure Pp from the pilot pressure circuit 102 as the base pressure. The valve 103 regulates the pressure in proportion to the line pressure PL from the pressure regulator valve 100. Also, the line pressure solenoid 90 and the port 100f
Between them, an accumulator 120 is interposed.

The suction port 110i of the oil pump 110
Is connected to the pump suction oil passage 104, and when the line pressure PL increases, the second pressure regulator valve 100 connected to the pump suction oil passage 104
The communication between the drain port 100d and the line pressure port 100p suppresses an increase in the line pressure PL. When the line pressure PL exceeds a predetermined value, the relief valve 140 operates to reduce the pressure in the line pressure circuit 101.

The first drain port 100e has a supply pressure of the cooler reducing valve 155, and the cooler reducing valve 15
5 control pressures are connected.

The cooler reducing valve 155 is
Prevent the cooler supply pressure from increasing beyond a certain value,
Cooler piping system is protected. Further, in order to prevent an abnormal rise in cooler system pressure when the cooler reducing valve 155 is stuck, the cooler relief valve 150 that operates more quickly is connected to the control pressure of the cooler reducing valve 155. .

The control pressure of the cooler reducing valve 155 is connected to a lubrication port 292 via a cooler port 291 and an orifice, and is supplied to each part of the continuously variable transmission with an infinite speed ratio to perform lubrication and cooling.

The line pressure circuit 101 adjusted by the pressure regulator valve 100 includes a manual valve 230 that responds to a shift lever or the like (not shown), a reverse torque cutoff valve 240 that responds to the tilt angle φ of the trunnion 23, and a transmission link 37. Via the step motor 13
6 and a shift control valve 246 responsive to the precess cam 135 are connected.

As shown in FIG. 2, the step motor 136 is driven by the shift control unit 80, and the CVT ratio ic becomes smaller (Hi side) when the number of steps is reduced. The speed change link 37 is driven to increase the number of steps.
The speed change link 37 is set such that the T ratio ic is on the large side (Lo side).
Drive.

Along with this, as shown in FIGS.
In the cam surface 135A of the precess cam 135, the relationship between the rotation direction and the driving direction of the feedback link 38 is such that the precess cam 135 has a large CVT ratio ic (L
When the precess cam 13 is displaced downward in FIG.
When 5 rotates to the small side (Hi side) of the CVT ratio ic, the end 38a of the feedback link 38 is displaced upward in the drawing, and the transmission link 37 engaged at the other end is driven.

<2. Shift control valve>
The shift control valve 246 is connected to the line pressure circuit 10.
1 and the supply port 246P connected to the hydraulic cylinder 30
Lo port 246L communicating with the oil chamber 30A of the hydraulic cylinder 30 and Hi port 24 communicating with the oil chamber 30B of the hydraulic cylinder 30.
6H and the spool 24 connected to the speed change link 37.
In response to the displacement of 6S, the line pressure PL increases
It is supplied to one of the 6L or Hi-side port 246H.
And the other port is the discharge port 246C or 24
6D.

A discharge port 246C that can communicate with the Lo port 246L is connected to the port 160k of the mode-fixed valve (mode switching control valve) 160 via the oil passage 105, and a port that can communicate with the Hi port 246H. 246D is connected to port 230d of manual valve 230 via oil passage 106.

<3. Manual Valve> Next, as shown in FIG. 7, the spool 230j of the manual valve 230 is set to one of three positions by a cam 231 which rotates according to a select lever or the like.

That is, when the D range is selected,
As shown in FIG. 7A, when the spool 230j is closest to the axis of the cam 231 and the R range is selected, as shown in FIG.
Displaced farthest from one axis, N range or P
In the case of the range, as shown in FIG.
The spool 230j is displaced to the middle position of the range.

At the time of selecting the D range When the forward range such as the D range or the Ds range used for sports running is selected, the spool 23 is moved to the position shown in FIGS.
When 0j is displaced, the line pressure port 230h communicating with the line pressure circuit 101 is connected to the D range pressure port 230i, and the line pressure PL is supplied to the D range pressure circuit 107.

The R range pressure port 230g communicating with the shuttle valve 270 is connected to the drain port 230f. This shuttle valve 270 supplies the higher of the oil pressure of the port 230g and the D-range pressure circuit 107 to the R-range pressure circuit 108. When the D-range is selected, the shuttle valve 270, as shown in FIGS. The valve body of the valve 270 moves to the right side in the figure, and the line pressure PL is supplied from the D range pressure circuit 107 to the R range pressure circuit 108, so that the direct connection clutch control valve 180 and the power circulation clutch control valve 20
0 is supplied with the line pressure PL.

Therefore, the power circulation mode clutch 9 and the direct connection mode clutch 10 can be engaged according to the operation mode.

In the D range, the manual valve 230 is connected to the port 23 communicating with the discharge port 246D of the shift control valve 246 via the oil passage 106.
0d is connected to the pump suction oil passage 104.

The manual valve 230 communicates with the port 230a connected to the port 240c of the reverse torque cutoff valve 240 and the port 230b connected to the mode fix valve 160, and connects the discharge port 246C of the shift control valve 246 to The oil passage 105 is connected to the port 240c of the reverse torque cutoff valve 240 via the mode fix valve 160.

Port 24 of reverse torque shutoff valve 240
Port 230 of manual valve 230 communicating with 0e
e is sealed in the D range.

When the N range or the P range is selected: When the stop range of the N range or the P range is selected,
As shown in FIG. 7B, the spool 230j is displaced to approximately the middle of the entire stroke to seal the line pressure port 230h, open the D range pressure port 230i to the atmosphere, and drain from below in the figure. The R range pressure port 230g is connected to the drain port 230f, the D range pressure circuit 107 and the R range pressure circuit 108 are both drained, and the line pressure PL to the direct connection clutch control valve 180 and the power circulation clutch control valve 200 is shut off. Then, the source pressures of the power circulation mode clutch 9 and the direct connection mode clutch 10 are cut off to release them.

When the stop range is selected, the discharge port 2 of the shift control valve 246 is connected via the oil passage 105 and the mode fix valve 160.
46C and the discharge port 24 of the shift control valve 246 via the oil passage 106.
Port 230d communicating with 6C is connected to port 23d, respectively.
0c is connected to the pump suction oil passage 104.

The port 230a communicating with the port 240c of the reverse torque shutoff valve 240 and the port 23 communicating with the port 240e of the reverse torque shutoff valve 240 are connected.
0e are respectively sealed.

When the reverse range is selected When the reverse range of the R range is selected, the spool 230j is displaced upward in the figure as shown in FIG.
30g communicates with the line pressure port 230h, while D
The range pressure port 230i is opened to the atmosphere and drained from below in the figure.

As a result, while the hydraulic pressure of the D range pressure circuit 107 is released, the line pressure PL is supplied to the R range pressure port 230g.
, The valve body of the shuttle valve 270 moves to the left in FIGS. 4 to 6, and the line pressure PL is supplied only to the R range pressure circuit 108, and the power circulation clutch control valve 2
00, the power circulation mode clutch 9 can be engaged, and no hydraulic pressure is supplied to the direct coupling clutch control valve 180, so that the direct coupling mode clutch 10 is released.

The port 230d communicating with the discharge port 246D of the shift control valve 246 communicates with the port 240e of the reverse torque cutoff valve 240 via the port 230e, and the oil chamber 30B of the hydraulic cylinder 30 is provided.
And the port 240e of the reverse torque cutoff valve 240 can be communicated.

Similarly, the shift control valve 246 via the oil passage 105 and the mode fix valve 160
Port 230b communicating with the discharge side port 246C of
The port 230c is connected to the pump suction oil passage 104.

The port 230a communicating with the port 240c of the reverse torque cutoff valve 240 is sealed.

<4. Clutch control valve> Next, the pilot pressure circuit 102 regulated by the pilot valve 103
Supplies the pilot pressure Pp to a direct coupling clutch solenoid 190 for controlling the direct coupling mode clutch 10 and a power circulation clutch solenoid 210 for controlling the power circulation mode clutch 9.

These direct-coupled clutch solenoids 190
The duty of the power circulation clutch solenoid 210 is controlled by the shift control unit 80 as shown in FIG.

The signal pressure PsolH / C regulated by the direct coupling clutch solenoid 190 is applied to the direct coupling clutch control valve 1
80 port 180e and the mode fix valve 16
0 port 160c.

The power circulation clutch solenoid 210
Is supplied to the port 200e of the power circulation clutch control valve 200.

The direct-coupled clutch control valve 180 drives the spool 180a in accordance with the signal pressure PsolH / C supplied to the port 180e, and outputs the D range pressure Pd (line pressure) from the D range pressure circuit 107 supplied to the port 180g. PL) to reduce the control pressure Ph from the output port 180c.
It is supplied to the inhibitor valve 170 as c. The port 180d is connected to the pump suction oil passage 104.

The signal pressure PsolH / C is applied to the spring 18
0b and the spool 180 against the D range pressure Pd
a, the signal pressure PsolH / C and the control pressure P
hc is set as shown in FIG. 8, and the signal pressure Ps
The control pressure Phc increases as olH / C increases.

When the signal pressure PsolH / C is 0, the direct connection clutch control valve 180
A predetermined control pressure Phc is generated by the urging force of the clutch 80b, and the predetermined control pressure is set to a hydraulic pressure equivalent to the return spring force of the direct connection mode clutch 10, and the stroke is reduced by a waste stroke of the clutch. However, the hydraulic pressure is set so as to cause almost no clutch engagement force.

Similarly, the power circulation clutch control valve 20
0 is the signal pressure PsolL /
The spool 200a is driven according to C, and the port 200g is driven.
Range pressure P from the R range pressure circuit 108 supplied to
r (line pressure PL) is reduced and supplied to the inhibitor valve 170 as a control pressure Plc from the output port 200c. The port 200d is connected to the pump suction oil passage 104.

The signal pressure PsolL / C is applied to the spring 20
0b and the spool 200 against the R range pressure Pr.
a, the signal pressure PsolL / C and the control pressure P
The relationship of lc is set as shown in FIG.
The control pressure Plc increases in accordance with the increase in olL / C.

When the signal pressure PsolL / C is 0, the power circulation clutch control valve 200 generates a predetermined control pressure by the urging force of the spring 200b. The hydraulic pressure is set to be equal to the return spring force of the circulation mode clutch 9 and the stroke is made only for the useless stroke of the clutch, but the hydraulic pressure is set so that the clutch engagement force is hardly generated.

The control valves 180, 200
Adjusts the control pressures Phc and Plc so as to reduce the shock during the operation mode switching control.

<5. Inhibitor valve> The control pressures Plc and Phc supplied from the direct connection clutch control valve 180 and the power circulation clutch control valve 200 are
Power is supplied to the power circulation mode clutch 9 and the direct connection mode clutch 10 via an inhibitor valve 170 provided with a spool 170a that responds to a tilt angle φ of 0.

The output port 180c of the direct coupling clutch control valve 180 and the output port 200c of the power circulation clutch control valve 200 are connected to the inhibitor valve 170, respectively.
Ports 170c and 170f.

Port 170 of inhibitor valve 170
e, 170h are connected to output ports 160h, 160f of the mode fix valve 160, respectively, and ports 170d, 170g of the inhibitor valve 170 are connected to the direct connection mode clutch 10 and the power circulation mode clutch 9, respectively, thereby displacing the spool 170a. The control pressures Phc and Plc and the mode fix valve 160
Are selectively supplied from the output ports 160f and 160h.

Spool 170 of inhibitor valve 170
A pin 171 is formed at an end of the power roller 20. The pin 171 is engaged with the cam groove 280a of the cam 280 connected to the trunnion 23, and the spool 170a is moved according to the tilt angle φ of the power roller 20. Driven.

In accordance with the position of 170a of the inhibitor valve 170, the hydraulic pressure from the port 170c or 170e is selectively supplied to the direct connection mode clutch 10 connected to the port 160d, and the power circulation connected to the port 170g. Port 170f or 1 to mode clutch 9
The hydraulic pressure from 70h is selectively supplied.

The cam 280 is a CV in FIGS.
When the T ratio ic changes to the Lo side (large side), it rotates clockwise, while when the CVT ratio ic changes to the Hi side (small side), it is coupled to the trunnion 23 that rotates counterclockwise.

4 to 6, the cam groove 280a of the cam 280 is used when the tilt angle φ of the power roller 20 (hereinafter simply referred to as the tilt angle φ) changes to the Hi side of the CVT ratio ic. The spool 170a of the inhibitor valve 170 is formed so as to stroke from the upper side to the lower side in the figure from a predetermined tilt angle φcl to φch.
On the Lo side of the CVT ratio ic, it is fixed upward in the figure, while on the Hi side from φch, it is fixed at a position below the figure.

The relationship between the CVT ratio ic and the tilt angle φ is as follows.
10, the Lo side (large side) of the CVT ratio ic is the small side of the tilt angle φ, and the Hi side (small side) of the CVT ratio ic is the large side of the tilt angle φ. The range of the tilt angle φ used for controlling the ratio ic is the maximum Lo = icl of the CVT ratio ic.
From the tilt angle φlo corresponding to o, the highest Hi of the CVT ratio ic
= Set in the range of the tilt angle φhi corresponding to
φlo <φhi.

Then, the spool 170a is connected to the spool 170a as shown in FIGS.
The tilt angle φ for changing the position between the upper side and the lower side of FIG.
(B), as shown in FIG. 10, the tilt angle is set to φc between φcl and φch.

In the state where the spool 170a is fixed upward in the figures in FIGS. 4 to 6, that is, in the state of FIG. 9A, the tilt angle is smaller than φcl (the CVT ratio ic is Lo),
The ports 170d and 170c communicate with each other, so that the direct connection mode clutch 10 is supplied with the control pressure Phc from the direct connection clutch control valve 180, and the ports 170g and 170f
And the control pressure Plc from the power circulation clutch control valve 200 is supplied to the power circulation mode clutch 9.

On the other hand, in the state where the spool 170a is fixed below in FIGS. 4 to 6, that is, in the state of FIG. 9C, the tilt angle is larger than φc (the CVT ratio ic is Hi).
The ports 170d and 170e communicate with each other, and the direct connection mode clutch 10 is connected to the port 16 of the mode fix valve 160.
The power circulation mode clutch 9 communicates with the port 160f of the mode fix valve 160 by communicating with the port 0h and the ports 170g and 170h.

Further, the position of the spool 170a is
At a tilt angle φc which is substantially intermediate between the upper part of FIG. 9A and the lower part of FIG. 9C, as shown in FIG. 9B, the port 170d communicating with the direct connection mode clutch 10 and the power circulation mode clutch Each of the ports 170g communicating with the port 9 is sealed, and the fastened or released state is maintained.

That is, the inhibitor valve 170 is
When the tilt angle is smaller than φc, the power circulation mode clutch 9
The output ports of the respective clutch control valves 180 and 200 are connected to the direct connection mode clutch 10, and when the tilt angle is larger than φc, the power circulation mode clutch 9 is switched according to the position of the spool 160 a of the mode fix valve 160.
Alternatively, the line pressure PL is supplied to one of the direct connection mode clutches 10, and the other is released to the atmosphere.

Therefore, the tilt angle is smaller than φc (CV
At the Lo side of the T ratio ic), the operation mode switching region is set, and the power circulation mode clutch 9 and the direct connection mode clutch 1
Since the hydraulic pressure of 0 can be controlled at the same time, the clutch capacity control of both is permitted when the operation mode is switched,
When the tilt angle is larger than φc (Hi side of the CVT ratio ic), one of the clutches is engaged and the operation mode is determined according to the position of the spool 160a of the mode fix valve 160.

Here, the tilt angle φc corresponds to the CVT ratio ic = icc (first speed ratio) as shown in FIG. 10, and the tilt angle φc of the CVT ratio ic and the IVT speed ratio e shown in FIG. In the relation, when the CVT ratio is icc, the IVT speed ratio = ecl in the power circulation mode, and the IVT speed ratio =
ech. Note that the IVT speed ratio e is the IVT ratio ii.
And the unit output shaft speed / unit input shaft speed.

In the CVT ratio icc corresponding to the tilt angle φc at which the position of the spool 170a switches, FIG.
As shown in the figure, the CVT ratio is larger than icc (Lo).
Side), power circulation mode clutch 9 (L / C in the figure)
And the direct connection mode clutch 10 (H / C) can simultaneously control the hydraulic pressure, and can switch the operation mode.

On the other hand, when the CVT ratio is equal to or lower than icc (Hi side), the simultaneous engagement prohibition region is set, and only one of the power circulation mode clutch 9 and the direct connection mode clutch 10 is permitted to be engaged and the power circulation mode is switched to the power circulation mode. Maintain one of the direct connection modes.

The power circulation clutch control valve 200
Of the hydraulic control range is not more than the CVT ratio icc and cannot be engaged simultaneously with the direct connection mode clutch 10, so that at least the IVT speed ratio ecl in FIG.
With the above, it is sufficient to set the oil pressure higher than the required oil pressure.

Normally, the transmission torque capacity TL / C required for the power circulation mode clutch 9 is, as shown in FIG.
It increases as the VT speed ratio e decreases (approaches GNP).

Therefore, the inhibitor valve 170 is
The hydraulic control range of the power circulation clutch control valve 200 is
L / Ccont. In FIG. V, it is possible to reduce the variation in the control pressure Plc and improve the control accuracy at the time of operating mode switching by improving the control accuracy, and also to reduce the shock at the time of operating mode switching. Has contributed.

Further, the stroke of the spool 170a of the inhibitor valve 170 only needs to be strokeable between two positions of an operation mode switching region and a simultaneous engagement prohibition region, and the switching between these two positions is determined by the tilt angle φc (switching position). Since the tilt angle is set between the tilt angle φcl and the tilt angle φch set in the vicinity, the spool 170 a
Thus, the stroke amount can be greatly reduced as compared with the case of driving in proportion to, and the miniaturization of the inhibitor valve 170 can be promoted.

<6. Mode Fix Valve> In FIGS. 4 to 6, the port 170 of the inhibitor valve 170 is shown.
e, the mode fix valve 160 that controls the oil pressure to 170h to allow the operation mode to be switched is provided with a signal pressure PsolH / C from the direct-coupled clutch solenoid 190.
The spool 160a which can be displaced in accordance with the position and is selectively restricted in displacement in accordance with the position of the cam 280 is housed therein.
Depending on the position of the spool 160a, the port 170e,
The oil pressure to 170h is determined.

Port 1 of mode fix valve 160
The signal pressure PsolH / C from the direct-coupled clutch solenoid 190 is guided to 60c, and urges the spool 160a against the spring 160b disposed below in FIGS.

As shown in FIGS. 4 to 6 and FIG. 9D, when the spool 160a is at the upper position, when the R range or the D range is selected via the R range pressure circuit 108, the line The output port 160d connected to the pressure circuit 101 is connected to the output port 160f connected to the port 170h of the inhibitor valve 170 that can communicate with the power circulation mode clutch 9, and the inhibitor valve 170 that can communicate with the direct connection mode clutch 10. The output port 160h connected to the port 170e is connected to the drain port 160g.

When the spool 160a is in the upper position, as shown in FIGS. 4 to 6 and FIG. 9D, the shift control valve 24
Port 160k connected to the discharge port 246C of No. 6
To the port 160j connected to the port 230b of the manual valve 230. The port 230b of the manual valve 230 selectively communicates with the reverse torque shutoff valve 240.

On the other hand, as shown in FIG. 9 (E), when the spool 160a is at the lower position in the figure, the port 160i connected to the D range pressure circuit 107 can be connected to the inhibitor capable of communicating with the direct connection mode clutch 10. The output port 160h connected to the port 170e connected to the port 170e of the valve 170 and the output port 160f connected to the port 170h capable of communicating with the power circulation mode clutch 9 are connected to the drain port 160g.

Further, when the spool 160a is in the lower position as shown in FIG.
Port 160k connected to the discharge port 246C of No. 6
Is connected to a port 160 l connected to the pump suction oil passage 104.
To communicate with

Here, the spool 160a of the mode fix valve 160 has a cam 2 which rotates according to the tilt angle φ.
A lock mechanism for restricting the displacement of the spool 160a by 80 is provided.

This locking mechanism is shown in FIGS.
(D), as shown in FIGS. 9 (E) and 12, a slider 161 (locking member) supported by a valve body (not shown) and slidable in the left-right direction in the figure, and one end of the slider 161. And a groove 163, 164 formed on the spool 160a and engageable with an end of the slider 161. The pin 162 is engaged with a cam groove 280b formed on the cam 280.

The cam groove 280b is disposed so as to be adjacent to the cam groove 280a for controlling the inhibitor valve 170 by the same cam 280, and as shown in FIGS. The slider 161 is displaced via the pin 162 according to φ, and when the slider 161 is opposed to the groove 163 or 164 of the spool 160a, the slider 161 can be engaged.
When the slider 161 is engaged with 63 or 164, the spool 160a can be fixed in the axial direction. The groove 163 is formed above FIGS. 4 to 6 and 9, and the groove 164 is formed below FIGS. 4 to 6 and 9.

When the operation mode is the power circulation mode,
Since there is no need to fasten the direct connection mode clutch 10, the signal pressure PsolH /
Since C is not generated, no oil pressure is supplied to the port 160c.

Therefore, the spool 160a of the mode fix valve 160 is provided with a spring 160b (elastic member).
4 to 6 and FIG. 9 (D).

In this position, the power circulation mode clutch 9
170h of inhibitor valve 170 that can communicate with
, An R range pressure Pr (line pressure PL) via an output port 160f, a port 160d, and an R range pressure circuit 108.
And an output port 170e that can communicate with the direct connection mode clutch 10 is drained through a port 160h and a port 160g.

At this time, the discharge port 246C of the shift control valve 246 communicates with the port 230d of the manual valve 230 via the oil passage 105 and the ports 160k and 160j of the mode-fixed valve 160. This port 230b further communicates with a port 240c of the reverse torque control valve 240,
In the case of the R range, the port 230b is connected to the pump suction oil passage 1
Communicate with 04.

When the operation mode is the direct coupling mode, the signal pressure PsolH / C from the direct coupling clutch solenoid 190 is generated in accordance with the operation state in order to engage the direct coupling mode clutch 10, and hydraulic pressure is supplied to the port 160c. .

Therefore, the spool 160a of the mode fix valve 160 is biased against the spring 160b and is located below as shown in FIGS. 4 to 6 and 9 (E).

In this position, the D range pressure Pd is guided to the port 170e of the inhibitor valve 170 which can communicate with the direct connection mode clutch 10 via the output port 160h, the port 160i, and the D range pressure circuit 107, and the power circulation is performed. The port 170h that can communicate with the mode clutch 10
It is drained via output port 160f and port 160g.

At this time, the discharge port 246C of the shift control valve 246 communicates with the pump suction oil passage 104 via the oil passage 105 and the ports 160k and 160l of the mode fix valve 160.

Next, the tilting angle φ of the power roller 20, the lock mechanism mainly including the cam groove 280b and the slider 161 will be described.

The cam groove 280b formed in the cam 280
Is <5. Inhibitor valve>, the tilt angle φ of the power roller 20 connected to the trunnion 23
It rotates according to.

Then, the cam groove 280b is formed as shown in FIGS.
In FIG. 12, when the tilt angle φ changes from the Lo side to the Hi side of the CVT ratio ic, a predetermined tilt angle φcl in FIG.
In the channel, the pin 162 is formed so as to displace the slider 161 from the left side in FIG. 12 (C) to the right side (FIG. 12A), and the tilt angle is smaller than φcl in the CVT ratio. On the Lo side of ic, the left side in the figure {Fig. 12 (C)}
On the other hand, when the tilt angle is higher than φch on the Hi side, the tilt angle is fixed at the position on the right side in the figure {FIG. 12 (A)}.

In FIG. 12, when the tilt angle is larger than φc (when the CVT ratio ic is Hi), FIG.
The slider 161 is inserted into the groove 163 or 164 of the spool 160a as shown in FIG.
While the tilt angle is not more than φc (CVT ratio i
12C, the slider 161 is moved to the groove 163 or 1 on the spool 160a as shown in FIGS.
64, the displacement of the spool 160a is allowed.
In this state, as described later, the signal pressure PsolH / C
, The spool 160a can be displaced, and switching of the operation mode is permitted.

The relationship between the tilt angle φ and the CVT ratio ic is set as shown in FIG. 10. The Lo side (large side) of the CVT ratio ic is on the small side of the tilt angle φ, and the CVT ratio ic is Hi. The side (small side) is the large side of the tilt angle φ, and the range of the tilt angle φ used for controlling the CVT ratio ic is the maximum Lo = icl of the CVT ratio ic.
From the tilt angle φlo corresponding to o, the highest Hi of the CVT ratio ic
= Set in the range of the tilt angle φhi corresponding to
φlo <φhi.

The slider 161 is moved to the spool 16
The tilt angle φc at which the insertion of 0a into the groove portion 163 or 164 is started is smaller than φc between the tilt angles φcl and φch, that is, as shown in FIGS.
This is when the CVT ratio ic is larger than icc in FIG.

In FIG. 12, when the tilt angle is smaller than φc, the slider 161 is at the position (C), the end of the slider 161 is separated from the side surface of the spool 160a, and the lock mechanism is released. Therefore, the axial displacement is allowed, and the spool 160a can stroke according to the magnitude of the signal pressure PsolH / C.

On the other hand, when the tilt angle is larger than φc, FIG.
As shown in FIG. 9A, the slider 161 is inserted into the groove 163 or 164 of the spool 160a, and the lock mechanism is activated.
It is fixed either above or below shown in (E).

That is, since the spool 160a cannot be displaced, the hydraulic pressure to the output ports 160f and 160h cannot be switched, and switching of the operation mode is prohibited.

Therefore, as shown in FIGS. 10 and 11, if the tilt angle of the power roller 20 is larger than φc, in other words, if the CVT ratio ic is smaller than icc (Hi side), the power circulation It is impossible to switch the operation mode by switching the mode clutch 9 and the direct connection mode clutch 10 or to simultaneously engage both clutches, and the operation mode is mechanically fixed according to the position of the spool 160a.

On the other hand, when the tilt angle is not more than φc, in other words, when the CVT ratio ic is larger (Lo side) than icc, the spool 160a is not locked by the slider 161 and the signal pressure PsolH / C Can be displaced according to
The operation mode can be switched by switching the power circulation mode clutch 9 and the direct connection mode clutch 10, and both clutches can be simultaneously engaged.

<7. Reverse torque shut-off valve> Next, FIG.
6, the reverse torque cutoff valve 240 connected to the manual valve 230 will be described.

The spool 2 of the reverse torque cutoff valve 240
40a engages with the cam groove 290a of the cam 290 connected to the trunnion 23, and is displaced according to the tilt angle φ.

Then, according to the displacement of the spool 240a, the ports 230a, 230
e are connected to the line pressure port 240d connected to the line pressure circuit 101 or the ports 240b and 240e connected to the pump suction oil passage 104.
Selectively communicate with 40f.

As shown in FIGS. 4 to 6 and FIG. 13, a pin 241 engaged with the cam groove 290a is formed at one end of the spool 240a of the reverse torque cutoff valve 240.
When the CVT ratio ic changes to the large side (Lo side), the trunnion 23 'and the cam 290 rotate counterclockwise in the figure, while when the CVT ratio ic changes to the small side (Hi side), the trunnion 23' and the cam 290 change. 290 rotates clockwise in the figure.

A cam groove 290a formed in the cam 290
Drives the spool 240a with the tilt angles φd and φr set near the tilt angle φgnp corresponding to the geared neutral point GNP.

Note that the relationship between the tilt angles φgnp, φd, and φr is as shown in FIG. 10, and φlo <φd <φgnp <
When φr <φhi, the relationship between these tilt angles and the CVT ratio ic is as follows: φgnp = icgnp, φd = icd, φr = ic
r, φlo = iclo, φhi = ichi.

In FIG. 13, the tilt angle is changed from φlo to φd.
13A, the spool 240a is fixed at the upper position in the figure, the line pressure port 240d communicates with the port 240e, and the line pressure is connected to the port 230e of the manual valve 230 as shown in FIG. While supplying PL, port 240c communicates with port 240b,
The port 230 a of the manual valve 230 is connected to the pump suction oil passage 104. Further, since the spool 240a is fixed upward in the drawing at a tilt angle less than φd, the total length of the valve can be reduced.

When the CVT ratio ic is smaller than iclo (Hi)
13), and when the tilt angle is equal to or more than φd, FIG.
As shown in (B), the spool 240a is displaced downward in the figure, and the port 240c is sealed.

Further, when the CVT ratio ic changes to the small side (Hi side) and the tilt angle becomes φgnp, as shown in FIG. 13 (C), the spool 240a is located substantially at the center of the stroke, and Pressure port 240d, port 240c,
The line pressure PL is supplied to the ports 230a and 230e of the manual valve 230 by making the port 240e communicate.

Next, from the tilt angle φgnp to φr, C
When the VT ratio ic changes to a smaller side, as shown in FIG. 13D, the port 240e is sealed while the line pressure port 240d and the port 240c communicate with each other.

When the tilt angle further changes from φr to φhi, as shown in FIG. 13E, the line pressure port 240d and the port 240c are maintained in communication with each other, while the port 240e is connected to 240f. The port 230e of the manual valve 230 is connected to the pump suction oil passage 1
04.

It is to be noted that the predetermined tilt angle φd is at least the maximum L in the control range (speed ratio width) of the CVT ratio ic to be used.
The tilt angle φrs of the RSP which is on the Hi side from o (iclo) and is the rotation synchronization point of the power circulation mode and the direct connection mode.
It is set to the Hi side of the CVT ratio ic rather than p.

<8. Operation> An example of the shift control by the shift control device as shown in FIGS. 1 to 13 will be described for each operating state.

{8.1 N-range or P-range} In the stop range of the N-range or the P-range mainly selected when the vehicle is stopped, as shown in FIG. 4 to FIG. 6 and FIG. Line pressure port 2 connected to pressure circuit 101
30h is sealed, and ports 230i and 230g connected to the D range pressure circuit 107 and the R range pressure circuit 108 are
Since each is drained, no hydraulic pressure is supplied to the power circulation mode clutch 9 and the direct connection mode clutch 10,
The continuously variable transmission 2 cannot transmit torque.

Therefore, a continuously variable transmission with an infinitely variable gear ratio cannot transmit power, and realizes neutral. In this state, the continuously variable transmission 2 also controls the oil chamber 30A (oil pressure = Plo) and the oil chamber 30B (oil pressure =
Both discharge ports 246C and 246D of Phi) are connected to the pump suction oil passage 104 through ports 230b and 230d as shown in FIG. Can be freely changed in the direction of.

When the vehicle is stopped (vehicle speed = 0), the CVT ratio ic and the IVT speed ratio e are controlled to the normal geared neutral point GNP.

{8.2 ND Select} When the driver puts a select lever (not shown) to D while the vehicle is stopped, the spool 230j of the manual valve 230 moves to the position shown in FIG.
7A, the line pressure port 230h communicates with the port 230i, and the line pressure PL is supplied to the D range pressure circuit 107.
D range pressure Pd (= PL) is generated.

When the vehicle is stopped, the spool 160a of the mode fix valve 160 is set to the CVT in the power circulation mode.
Because ratio ic is geared neutral point GNP,
As shown in FIG. 10, since the tilt angle φ = φgnp> φc, as shown in FIGS. 4 to 6 and FIG. 9 (D), the spool 160a is located at the upper position in the drawing. Locked.

When the CVT ratio ic is controlled to the geared neutral point GNP, the D range pressure Pd from the D range pressure circuit 107, the shuttle valve 270, and the R range pressure circuit 108 is applied to the output port of the mode fix valve 160. The power circulation mode clutch 9 (L / C) which has been supplied to the power circulation mode clutch 9 via the output port 160g and the output port 170g of the inhibitor valve 170 and has been released in the N range or the P range is engaged.
The select control ends.

8.3 Starting and Power Circulation (L) Mode Running In the released state of the accelerator pedal (APS = 0), as disclosed in JP-A-10-267117, in order to obtain a predetermined creep torque, FIG. 11, FIG.
As shown in FIG.
(Larger side of T ratio ic).

When the accelerator pedal is depressed, the control of the normal CVT ratio ic is controlled so as to achieve a predetermined rotation of the input shaft with respect to the vehicle speed VSP.
As shown in the shift map of FIG. 4, the accelerator pedal depression amount AP
S and the target input shaft rotation speed Nin according to the vehicle speed VSP are determined.

In the shift map of FIG. 14, the target CVT ratio ic is indicated by the target input shaft speed Nin / the continuously variable transmission output shaft speed No, and the CVT ratio icrsp corresponding to the rotation synchronization point RSP; Target CVT ratio and vehicle speed VSP
, The operation mode is also determined. This map shows a case where the operation mode is switched at the CVT ratio icrsp corresponding to the rotation synchronization point RSP.

Then, the target IVT speed ratio e = Nout / Nin is calculated by dividing the unit output shaft rotation speed Nout by the target input shaft rotation speed Nin, and further considering the operation mode from the map of FIG. , The target CVT ratio ic is calculated.

Thereafter, the inverse calculation of FIG.
The target tilt angle φ is calculated from the VT ratio ic, and the position of the step motor 136 is feedback-controlled with respect to the target tilt angle.

The operation of the hydraulic circuit in the power circulation mode is as follows.

Spool 230 of manual valve 230
j is at the position shown in FIGS. 4 to 6 and FIG. 7 (A) and the mode fix valve 160 is set at the position shown in FIG. 9 (D). Exhaust port 246C on Plo side of shift control valve 246
Are ports 160k, 160j, ports 230b, 23
Port 24 of the reverse torque shut-off valve 240
0c.

On the other hand, the discharge port 246D on the Phi side of the shift control valve 246 is connected to the ports 230d,
It is connected to the pump suction oil passage 104 via 30c.

The line pressure PL is supplied to 240 d of the reverse torque cutoff valve 240, and the spool 240 a is set at the position of the geared neutral point GNP shown in FIGS. 4 to 6 by the groove 290 a of the cam 290.

At the tilt angle φgnp corresponding to the geared neutral point GNP, the port 240c of the reverse torque cutoff valve 240 to which the Plo side discharge port 246C of the shift control valve 246 is connected.
Communicates with the line pressure port 240d, but is cut off from the port 240b connected to the pump suction oil passage 104.

Therefore, at the geared neutral point GNP, the shift control valve 246
Of the oil chamber 30A always becomes the line pressure PL regardless of the spool position of the shift control valve 246.

On the other hand, the Phl-side discharge port 246D of the shift control valve 246 is connected to the pump suction oil passage 10
4, the oil pressure = Phi of the oil chamber 30B varies between almost 0 and the line pressure PL according to the position of the spool 246S, but the oil pressure Phi becomes higher than Plo. Is impossible.

Therefore, at the geared neutral point GNP in the power circulating mode in the D range, the relationship of the differential pressure Plo ≧ Phi always holds.

The relationship between the pressure differences is that the tilt angle is φd (FIG. 1).
0, see FIG. 11).
The cam groove 290a is set.

As a result, in the power circulation mode of the D range (forward range), the IVT speed ratio e is changed to the forward side (e ≧
0), when the geared neutral point GNP is closer to the geared neutral point GNP (Lo side of the IVT speed ratio e) than the predetermined value ed (CVT ratio = icd), the torque on the engine brake side (= reverse side) is not generated. Can control.

Next, the IVT speed ratio e is shifted forward from the geared neutral point GNP (e = o),
When shifting to the Lo side of the VT ratio ic, the spool 240a of the reverse torque cutoff valve 240 moves upward in FIGS.

The tilt angle changes from φgnp to φd (CV
When the gear is shifted to the T ratio (icd), the port 240c of the reverse torque shutoff valve 240 communicating with the discharge port 246C of the oil chamber 30A is further tilted after being shut off from the line pressure port 240d as shown in FIG. When the angle shifts to φlo, the spool 240a of the reverse torque shutoff valve 240 is brought to the position shown in FIG.
40c communicates with the port 240b, and the pump suction oil passage 1
04 and the hydraulic pressure Plo is released.

Thus, the Plo side discharge port 246
Port 24 of the reverse torque shutoff valve 240 communicating with C
0c is almost the atmospheric pressure, and the hydraulic pressure Pl of the hydraulic cylinder 30
The relationship between o and Phi is the shift control valve 24
6 can be replaced according to the position of the spool 246S.

In the power circulation mode of the D range,
When the T speed ratio e is positive (forward side), a predetermined value ed (FIG. 11)
When the vehicle speed is on the speed increasing side (i.e., on the larger side of the IVT speed ratio e), the transmission torque on the engine brake side (reverse running = reverse side) can be controlled.

That is, in the forward range of the power circulation mode, in the low speed range where the engine brake is not required (CVT ratio icd or less in FIG. 11), even if the step motor 136 fails due to the failure of the shift control control unit 80 or the like, the CVT ratio is reduced. Even if an erroneous operation that is driven to the small side (Hi side) of ic occurs, the generation of torque to the engine brake side (reverse side) at the predetermined speed ratio icd before the CVT ratio ic reaches the geared neutral point GNP. Can be prevented.

[8.4 Operation Mode Switching (Circulation → Direct Connection)] While traveling based on the shift map shown in FIG. 14, when the vehicle speed VSP increases or the accelerator pedal is released, etc.
The target IVT speed ratio e is larger than a predetermined speed ratio (for example, the rotation synchronization point ersp, see FIG. 11) (Hi side).
Then, when it is determined to switch from the power circulation mode (L mode) to the direct connection mode (H mode), the operation mode switching control for switching the engaged clutch from the power circulation mode clutch 9 to the direct connection mode clutch 10 is performed. .

It is to be noted that, as shown in the shift map of FIG. 14, for example, the target value of the CVT ratio ic determined by the vehicle speed VSP and the accelerator depression amount APS is determined by the CVT corresponding to the rotation synchronization point RSP, as shown in the shift map of FIG. Ratio icrsp
You may go when you cross.

In the power circulation mode, the signal pressure PsolL / C is output from the power circulation clutch solenoid 210, and the control pressure Plc from the power circulation clutch control valve 200 is output to the power circulation mode clutch 9.

However, unless the CVT ratio is in the operation mode switching region where the CVT ratio is larger than icc (φ <φc) due to the function of the inhibitor valve 170, the spool 170a will
Since the positions are (B) and (C), the control pressures Plc and Phc of the power circulation clutch control valve 200 and the direct connection clutch control valve 180 are not supplied to the clutch.

The operation mode switching area is the IVT
When the speed ratio e is used, as shown in FIG. 11, the range is equal to or more than ecl and less than ech across the speed ratio ersp at the rotation synchronization point RSP.

The mode fix valve 160 is
In the operation mode switching prohibition region on the small side where the CVT ratio is equal to or less than icc, the operation mode cannot be switched because the lock mechanism operates and the spool 160a is locked as shown in FIG. 9D. .

Therefore, the operation mode switching control is performed according to FIG.
As shown in FIG. 1, by simultaneously controlling the power-circulating clutch control valve 200 and the direct-coupled clutch control valve 180 in a region equal to or higher than the CVT ratio icc, smooth switching control is performed.

When the accelerator depression amount APS is constant and the vehicle speed V
In the automatic upshift when the SP increases, the target value of the IVT speed ratio e continuously changes. Therefore, in FIG. 11, the CVT ratio ic is equal to or greater than icc, and the start of the shift and clutch switching is determined. After the clutch is switched at the synchronization point RSP, the speed is shifted again toward the target CVT ratio ic. At the rotation synchronization point RSP, the rotational speeds of the continuously variable transmission output shaft 4 and the unit output shaft 6 match, and the constant transmission output shaft 3c matches the rotational speed of the carrier 5b. Shock at the time of release can be prevented, and smooth switching can be performed.

When the target of the IVT speed ratio e suddenly changes from the power circulation mode to the direct connection mode due to a foot release upshift that releases the accelerator that has been depressed while the vehicle is traveling in the power circulation mode, the CVT shown in FIG.
After shifting the gear ratio to a region where the ratio ic is equal to or greater than icc, the power circulating clutch control valve 200 and the direct coupling clutch control valve 180 are simultaneously operated to complete the clutch change control in the half-clutch state. ic
Is controlled toward the target value.

In the region where the CVT ratio ic is equal to or larger than icc, as shown in FIG.
60 is released and the spool 160a is allowed to be displaced. In this state, the direct connection clutch solenoid 190 is energized and the signal pressure P
When soIH / C occurs, the mode fix valve 1
60 strokes downward in FIGS. 4-6, resulting in FIG.
In the position (E), the supply of the hydraulic pressure to the inhibitor valve 170 can be switched to the power circulation mode clutch 9 and the direct connection mode clutch 10 by turning on and off the signal pressure PsolH / C.

However, when the CVT ratio is larger than the predetermined value icc, the inhibitor valve 170 controls the control pressures Plc and Phc of the power circulation clutch control valve 200 and the direct coupling clutch control valve 180 by using the ports 170f and 170g and the ports 170c and 170d. Are supplied to the respective clutches, and the oil passages (ports 170e, 170h) from the mode fix valve 160 are shut off.
00 is controlled by the directly-coupled clutch control valve 180, so that, for example, if both clutches are half-clutched, smooth mode switching can be performed instead of simple on / off switching.

Here, the power circulation clutch control valve 20
0 and the CVT ratio icc at which the control of the direct-coupled clutch control valve 180 can be performed at the same time, is higher than the CVT ratio icc that permits the transmission of torque to the engine brake side by the rotation synchronization point RS.
In the area where the mode switching control is performed (L / C & H / C control is possible in FIG. 11), the C
Since the VT passing torque (the passing torque of the continuously variable transmission 2) can also be transmitted, the CVT passing torque is inverted during the mode switching control, but the CVT ratio controllability is not deteriorated. It has become.

In the case of a continuously variable transmission with an infinite transmission ratio, the direction of transmission torque passing through the continuously variable transmission 2 (passing torque)
Differs between the direct connection mode and the power circulation mode when moving forward as follows.

In FIG. 1, the direction in which torque is transmitted from the input disk 21 to the output disk 22 is positive, and the direction in which torque is transmitted from the output disk 22 to the input disk 21 is negative.

In the direct connection mode, since the torque from the continuously variable transmission 2 is transmitted to the unit output shaft 6, the vehicle is driven by the torque in the positive direction, while the engine brake is operated by the torque in the negative direction.

Therefore, in the direct connection mode, the transmission torque on the drive side can be controlled by controlling the positive torque passing through the continuously variable transmission 2.

On the other hand, in the power circulation mode, the power circulation mode clutch 9 is engaged, while the direct connection mode clutch 1 is engaged.
0 is released, the difference between the revolution speed of the pinion of the carrier 5b driven by the constant transmission 3 and the rotation speed of the sun gear 5a corresponding to the CVT ratio of the continuously variable transmission 2 in FIG. The forward / backward movement and the geared neutral point GNP are determined. In this power circulation mode, the direction of the torque passing through the continuously variable transmission 2 changes depending on the traveling direction of the vehicle.

First, when moving forward in the power circulation mode,
When the revolution speed of the pinion of the carrier 5b is higher than the rotation speed of the sun gear 5a,
When the VT ratio ic is on the larger side (Lo side) than the geared neutral point GNP shown in FIG. 11, the torque transmitted to the carrier 5b is transmitted to the ring gear 5c and the sun gear 5a. 2 is input from the output disk 22 side via the chain 4b, and becomes negative. Incidentally, the torque transmitted from the output disk 22 to the input disk 21 is transmitted from the unit input shaft 1 to the constant transmission 3, and the driving force circulates.

On the other hand, when the vehicle is traveling in reverse in the power circulation mode, when the rotation speed of the sun gear 5a is sufficiently higher than the revolution speed of the pinion of the carrier 5b, that is, the CVT ratio of the continuously variable transmission 2 becomes geared neutral as shown in FIG. When the torque is on the smaller side (Hi side) than the point GNP and the torque transmitted to the sun gear 5a is transmitted to the carrier 5b and the ring gear 5c at this time, the continuously variable transmission 2
Is in the forward direction transmitted from the input disk 21 to the output disk 22, and the torque transmitted to the carrier 5 b via the sun gear 5 a circulates again to the input disk 21 via the constant transmission 3.

Therefore, at the time of forward movement in the power circulation mode, the transmission torque on the drive side can be controlled by controlling the negative torque passing through the continuously variable transmission 2. By controlling the positive torque passing through the continuously variable transmission 2, the transmission torque on the drive side can be controlled.

[8.5] Direct connection (H) mode driving [0185] After the operation mode is switched from the power circulation mode to the direct connection mode in 8.4 above, the direct connection mode is not changed unless the direct connection mode is switched to the power circulation mode. The direct-connection mode travel is performed in which the continuously variable transmission 2 is controlled and travels in a state where the clutch 10 is engaged.

In the direct connection mode, even when the control pressure Plc is suddenly generated due to a failure of the power circulation clutch control valve 200, the CVT ratio ic is equal to or less than icc (the tilt angle is φc
4 to 6 and FIG.
As shown in (C), the spool 1 of the inhibitor valve 170
70a is displaced downward in the figure, and the mode fix valve 1
9E, the output port 170g communicating with the power circulation mode clutch 9 is connected to the ports 170h, 160f, and 160f.
Since the oil is drained through g, the oil pressure of the power circulation mode clutch 9 is released to the atmosphere regardless of the state of the power circulation clutch control valve 200.

Note that the simultaneous engagement prohibition region is the CVT ratio ic
As shown in FIG. 11, when the IVT speed ratio e is used instead of c, the region is equal to or smaller than ecl or equal to or larger than ech.

Therefore, even if the power circulation clutch control valve 200 or the like breaks down, it is possible to reliably prevent the power circulation mode clutch 9 from being engaged and to prevent a shift (downshift) unintended by the driver. .

On the other hand, when the CVT ratio ic is equal to or larger than icc, as shown in FIG. 11, the operation mode switching region is such that the power circulation mode clutch 9 and the direct connection mode clutch 10 can be simultaneously engaged. Even if both clutches are simultaneously engaged due to such a failure, the change in the IVT speed ratio e is within the range from ech to ecl shown in FIG.
Since the shift width is small, a large downshift does not occur.

That is, by setting the CVT ratio icc permitting simultaneous engagement of both clutches to the rotation synchronization point RSP side, the operation of the inhibitor valve 170 and the mode fix valve 160 allows the power circulating clutch control during running in the direct connection mode. Even if the valve 200 fails, the IVT speed ratio e
Can be reduced, and an unintended downshift can be reduced.

{8.6 Operation Mode Switching (Direct Connection → Dynamic Circulation)} The operation mode switching from the direct connection mode to the power circulation mode is the reverse of the operation mode switching from the power circulation mode to the direct connection mode shown in 8.4 above. become.

While the vehicle is running in the direct connection mode, the vehicle speed VSP decreases and the accelerator pedal is depressed.
The target CVT ratio ic is the CVT ratio ic for mode switching.
When the vehicle speed exceeds rsp, switching control from the direct connection mode traveling to the power circulation mode is started.

In the direct connection mode, the direct connection mode clutch 10
From the direct-coupled clutch solenoid 190 and the direct-coupled clutch control valve 180 so that the signal pressure PsolH /
C and the control pressure Phc are output.

However, due to the action of the inhibitor valve 170, if the CVT ratio is not higher than icc, the spool 1
70a is located below FIGS. 4 to 6 and FIG. 9C, so that the control pressures Plo and Phc of the power circulation clutch control valve 200 and the direct coupling clutch control valve 180 are not supplied directly to the clutch. .

The mode fix valve 160 is
When the CVT ratio is equal to or lower than icc, as shown in FIG. 9E, the lock mechanism is operated and the displacement is regulated, so that the operation mode switching is prohibited.

Therefore, the operation mode switching control is performed as shown in FIG.
As shown in FIG. 1, in the region where the CVT ratio ic is equal to or greater than icc, smooth switching is performed by simultaneously controlling the power circulation clutch control valve 200 and the direct coupling clutch control valve 180.

First, in the coast down in which the accelerator is released, the target value of the IVT speed ratio e continuously changes. Therefore, after the CVT ratio ic becomes equal to or greater than icc, the shift and clutch switching are determined. Rotation synchronization point R
After switching the clutch at SP, CVT ratio ic
To the small side (Hi side) (the IVT speed ratio e is Lo
side).

On the other hand, when the target value of the IVT speed ratio changes suddenly by depressing the accelerator, once the CVT ratio ic becomes ic
After shifting the gears to a region equal to or greater than c, the shift control is completed using the power circulation clutch control valve 200 and the direct coupling clutch control valve 180, and then the CVT ratio ic is controlled to the target.

When the CVT ratio ic is equal to or higher than icc, the spool 160a of the mode fix valve 160 is unlocked as shown in FIG. 12C. As a result, the signal pressure PsoIH / C is reduced, and the mode-fix valve 160 returns to the state shown in FIG.
6, the output pressures 160f and 160d on the side of the power circulation mode clutch 9 are communicated, and the line pressure PL supplied to the ports 170e and 170f of the inhibitor valve 170 can be switched and turned on and off. .

However, when the CVT ratio is larger than icc,
The spool 170a of the inhibitor valve 170 is shown in FIG.
At the position (A), the control pressures Plo and Phi of the power circulation clutch control valve 200 and the direct connection clutch control valve 180 are set.
To ports 170f, 170g and ports 170c, 1
The oil is supplied from the mode fix valve 160 (ports 170e,
Since 170h) is shut off, the actual mode switching is controlled by the power circulation clutch control valve 200 and the direct coupling clutch control valve 180, and smooth mode switching can be performed instead of simple on / off switching.

{8.7 R range} When the driver sets the select lever (not shown) from the stop range to the R range (reverse range), the manual valve 2 linked to this is set.
7C, the spool 230j is moved upward in the drawing as shown in FIG. 7C, the R range pressure port 230g communicates with the line pressure port 230h, the line pressure PL is supplied to the R range pressure circuit 108, and the R range Pressure Pr (= PL) is generated.

The spool 160a of the mode fix valve 160 is in the power circulation mode when stopped,
As shown in (D), the spool 1
60a is locked.

Then, while the CVT ratio ic is controlled to icgnp corresponding to the geared neutral point GNP, as shown in FIGS. 4 to 6, the R range pressure Pr
Is supplied to the power circulation mode clutch 9 through the port 160d and the output port 160f of the mode fix valve 160 and the port 170h and the output port 170g of the inhibitor valve 170.
Are concluded and the select control ends.

When the accelerator is released, the above-mentioned ND
As in the case of the select operation, the stepping motor 136 is moved backward (IV in FIG. 11) so as to obtain a predetermined creep torque.
(T speed ratio e is negative).

Also, the control of the CVT ratio ic in the R range is performed in the same manner as in the D range in the power circulation mode.
Based on the SP and the accelerator depression amount APS, the target CVT ratio ic is calculated from the target input rotation Nin obtained from the shift map in FIG. 14 to drive the step motor 136.

In the R range, the manual valve 23
0 is at the position shown in FIG.
0 is set to the position shown in FIG. 9D, and the Plo side discharge port 246C of the shift control valve 246 communicates with the pump suction oil passage 104 via the ports 160k, 160j, 230b and the port 230c.

The Phi-side discharge port 246D of the shift control valve 246 is connected to the manual valve 2
30 and the port 240e of the reverse torque shutoff valve 240.

Spool 2 of reverse torque cutoff valve 240
The position 40a is regulated by the cam groove 290a of the cam 290 in accordance with the tilt angle φ, and becomes a position corresponding to the geared neutral point GNP immediately after switching to the R range, the inclination corresponding to the geared neutral point GNP. At the turning angle φgnp, as shown in FIG. 13C, the reverse torque shutoff valve 240 communicating with the Phi-side exhaust port 246D of the shift control valve 246.
Port 240e is connected to the line pressure port 240d, and is connected to the port 2 connected to the pump suction oil passage 104.
40f is shut off.

At the geared neutral point GNP, the Phi side discharge port 246D of the shift control valve 246 has the line pressure PL. Therefore, regardless of the spool position of the shift control valve 246, the oil pressure Phi of the oil chamber 30B is equal to the line pressure PL. Become.

Since the discharge port 246C on the oil chamber 30A side is connected to the pump suction oil passage 104, the oil pressure Plo of the oil chamber 30A changes from substantially 0 to the line pressure PL according to the position of the shift control valve 246. However, Plo cannot have a higher pressure than Phi.

Therefore, at the geared neutral point GNP in the R range, the relationship of the differential pressure Phi ≧ Plo always holds.

As shown in FIG. 10, FIG. 11, and FIG. 13, the groove 290a of the cam 290 is set so that the relationship is established if the tilt angle is not less than φr (not more than the CVT ratio icr). In the range, when the IVT speed ratio e is on the reverse side and the tilt angle φ is on the deceleration side (GNP side) from the predetermined value φr, the torque on the engine brake side (reverse running = forward side) is not generated. become.

In the running of the R range, in FIG.
When the VT speed ratio e is on the reverse side (e ≦ 0, the predetermined speed ratio er =
At a point closer to the geared neutral point GNP than the CVT ratio icr) (Lo side of the IVT speed ratio e), control can be performed so that torque on the engine brake side (= forward side) is not generated.

Next, the IVT speed ratio e moves backward from the geared neutral point GNP (e = o), that is, CVT
When the speed is shifted to the Hi side of the VT ratio ic, the spool 240a of the reverse torque shutoff valve 240 moves downward in FIGS.

The tilt angle changes from φgnp to φr (CV
When the gear is shifted to the T ratio icr), the port 240e communicating with the discharge port 246D of the oil chamber 30B is cut off from the line pressure port 240d as shown in FIG. By shifting the speed, the spool 240a of the reverse torque cutoff valve 240 is moved to the position shown in FIG.
, The port 240e communicates with the port 240f, is connected to the pump suction oil passage 104, and the hydraulic pressure Phi is released.

As a result, the Phi side discharge port 246
Port 24 of reverse torque shut-off valve 240 communicating with D
0e is almost the atmospheric pressure, and the hydraulic pressure Pl of the hydraulic cylinder 30 is
The relationship between o and Phi is as follows: shift control valve 2
It is also possible to replace the spool 46 according to the position of the spool 246S.

Therefore, in the reverse range, when the IVT speed ratio e is negative (reverse side) and is higher than the predetermined value er (high side of the reverse range), the engine brake side (forward side) is increased. It becomes possible to control the transmission torque.

In a low-speed range where the engine brake is not required in the reverse range (i.e., the CVT ratio icr or more in FIG. 11), a malfunction occurs in which the step motor 136 and the like are driven to the large side (Lo side) of the CVT ratio ic. Even CVT
At a predetermined gear ratio icr before the ratio ic reaches the geared neutral point GNP, generation of torque on the engine brake side (reverse running side) can be prevented.

As described above, the inhibitor valve 170 responding to the tilt angle φ of the power roller 20, the reverse torque cutoff valve 240 and the mode fixing valve 160 responding to the tilt angle φ and the signal pressure PsolH / C are provided. ,
Until the CVT ratio ic becomes larger than the predetermined value icd, the power circulation mode clutch 9 and the direct connection mode clutch 1
0 can be reliably prohibited from being simultaneously engaged, and similarly to the latter conventional example, if simultaneous engagement occurs due to a failure or the like, an unintended shift toward the rotation synchronization point RSP can be prevented.

The CVT ratio ic allowing simultaneous engagement of the power circulation mode clutch 9 and the direct connection mode clutch 10
The operation mode switching region above c is the CVT ratio ic
Since c is set closer to the rotation synchronization point RSP than the geared neutral point GNP, even if simultaneous engagement occurs due to a failure or the like, the shift width of the speed ratio e is small. However, by simultaneously engaging both clutches, it is possible to smoothly switch the operation mode while suppressing the shock.

Further, the reverse torque cutoff valve 240 prevents transmission of torque on the engine brake side in the low speed range where the CVT ratio is lower than icd on the forward side and in the low speed range where the CVT ratio is higher than icr on the reverse side. Even if the step motor 136 malfunctions toward the engine brake side due to a failure or the like, the torque on the engine brake side is interrupted, so that the engine brake due to the failure in the low speed range can be prevented.

FIGS. 17 to 19 show a second embodiment, in which a lock mechanism for regulating the displacement of the spool 160a of the mode-fix valve 160 shown in the first embodiment in accordance with the tilt angle φ is shown. In addition to replacing the solenoid 260, the cam 280 is abolished, and the inhibitor valve 177 is controlled by the signal pressure PsolINH from the solenoid 263. Other configurations are the same as those of the first embodiment.

A solenoid 260 which is provided with an extendable rod 261 and is controlled by the speed change control unit 80 at a position opposing the grooves 163 and 164 formed on the spool 160a of the mode fix valve 160.
Is arranged.

When the solenoid 260 is not excited, the rod 261 contracts to allow the displacement of the spool 160a. On the other hand, when the solenoid 260 is excited, the rod 261 extends to move to the groove 163 or 164 of the spool 160a. It is inserted and regulates the displacement of the spool 160a.

In the solenoid 260, the rod 261 is engaged with the groove 163 or 164, and the displacement of the spool 160a is prohibited outside the operation mode switching region.

The port 160d of the mode fix valve 160 communicates with the output port 200c of the power circulating clutch control valve 200 in place of the R range pressure Pr of the first embodiment to receive the control pressure Plc. The port 160i communicates with the output port 180c of the direct coupling clutch control valve 180 and receives the control pressure Phc instead of the D range pressure Pd of the first embodiment.

On the other hand, the inhibitor valve 177 is provided with the pin 17 which engages with the cam groove 280a shown in the first embodiment.
1 while eliminating the signal pressure Ps from the solenoid 263.
An oil chamber 177i for introducing olINH is provided, and a spring 17 is provided.
The spool 177a is driven against 7b (elastic member).

The output ports 177d and 177g communicate with the direct connection mode clutch 10 and the power circulation mode clutch 9, respectively, and the port 177h communicates with the output port 160f of the mode fix valve 160.
e is the output port 160 of the mode fix valve 160
h, and the port 177c is connected to the output port 180c of the direct-coupled clutch control valve 180 and the port 177f.
Is the output port 20 of the power circulation clutch control valve 200
0c.

[0229] Solenoid 263 regulates pilot pressure Pp from pilot pressure circuit 102 in response to a command from shift control unit 80 to generate signal pressure PsolINH.

That is, when the signal pressure PsolINH exceeds a predetermined value, as shown in FIG. 17, the hydraulic pressure of the port 177i rises, and the spool 177b opposes the spring 177b.
7a is displaced downward in the figure, and output ports 177d, 17
7g is communicated with the ports 177e and 177h to control the direct connection mode clutch 10 and the power circulation mode clutch 9 according to the position of the spool 160a of the mode fix valve 160.

On the other hand, when the signal pressure PsolINH is equal to or less than the predetermined value, the spring 177b urges the spool 177a upward in the figure, and the output ports 177d, 177g
To the ports 177c and 177f to connect the direct-coupled clutch control valve 180, the power circulation clutch control valve 2
The direct connection mode clutch 10 and the power circulation mode clutch 9 are controlled according to the control pressures Phc and Plc from 00.

Next, the transmission control control unit 80
Will be described with reference to the flowchart of FIG.

At step S1 in FIG. 18, the unit input shaft speed Ni and the continuously variable transmission output shaft speed No are read, and the CVT ratio ic is calculated from ic = Ni / No.

Next, in step S2, the CVT ratio icc for determining the operation mode switching region is calculated from the map shown in FIG. 19 based on the unit input shaft rotation speed Ni.

The map of FIG. 19 is set so that the CVT ratio icc increases as the unit input shaft speed Ni, that is, the engine speed Ne increases.

Then, in step S3, the current CVT
The ratio ic is the CVT ratio icc obtained in step S20.
It is determined whether it is greater than or equal to.

If the CVT ratio exceeds the CVT ratio icc permitting simultaneous engagement of the clutch, the process proceeds to step S4, where the solenoid 260 is de-energized, the rod 261 is contracted, and the displacement of the spool 160a is allowed. The solenoid 263 to drive the signal pressure PsolINH
And the simultaneous engagement of the power circulation mode clutch 9 and the direct connection mode clutch 10 is enabled.

On the other hand, the CVT ratio is the calculated CVT ratio ic
If it is less than c, the process proceeds to step S5, in which the solenoid 260 is excited to extend the rod 261 and the spool 1
In addition to restricting the displacement of the clutch 60a, the solenoid 263 is stopped, the signal pressure PsolINH is set to 0, and the simultaneous engagement of the power circulation mode clutch 9 and the direct connection mode clutch 10 is prohibited.

In this case, the power circulation mode clutch 9
That permits simultaneous engagement of the clutch 10 and the direct connection mode
The ratio icc becomes variable according to the engine speed Ne,
As the engine speed Ne increases, the CVT ratio icc approaches the CVT ratio icrsp corresponding to the rotation synchronization point RSP, and the range of the speed ratio e in which simultaneous engagement is permitted is reduced.

When the unit input shaft rotation speed Ni is high,
Even if the gear ratio width for downshifting is small, the change amount of the engine speed Ne becomes large. On the other hand, when unintended simultaneous engagement occurs in a state where the unit input shaft rotation speed Ni is high, if the CVT ratio icc that permits simultaneous engagement is fixed so that the amount of change in the engine rotation speed Ne is reduced, then, When the unit input shaft rotation speed Ni is low, the region where the operation mode can be switched is reduced, and controllability is reduced.

Therefore, as shown in the map of FIG.
As the unit input shaft rotation speed Ni increases, the CVT
By making the ratio icc closer to the rotation synchronization point RSP (icrsp), the operation mode switching region is reduced, and when the unit input shaft speed Ni is high, the engine speed Ne changes even if unintended simultaneous engagement occurs. When the unit input shaft rotation speed Ni is low, the CVT ratio icc is also reduced (the operation mode switching area is expanded), and the area where operation modes can be switched is expanded to improve controllability. Can be done.

In this case, the cam 280 shown in the first embodiment is not required, thereby simplifying the valve body of the continuously variable transmission with an infinite transmission ratio, and permitting simultaneous engagement (ic> icc). ) Can be set arbitrarily, and the degree of freedom in design can be improved.

When the signal pressure PsolH / C from the direct-coupled clutch solenoid 190 is supplied to the port 160c, the spool 160a is urged against the spring 160b, and when the signal pressure PsolH / C is not acting, As shown in FIG. 9D, the spool 160a is pushed upward by the 160a, and at this time, the ports 160d and 160f communicate with each other, while the port 160h is drained. Therefore, the control pressure Plc is applied only to the power circulation mode clutch. Alternatively, the D range pressure Pd can be supplied to prevent simultaneous engagement of both clutches.

In addition, instead of the signal pressure PsolH / C of the direct-coupled clutch solenoid 190, the port 160c
Signal pressure Pso from power circulation clutch solenoid 210
1L / C can be used, but in this case, the signal pressure P
When the sol L / C is generated, the power circulation mode is set. However, when the oil temperature is low, the rising of the signal pressure Psol L / C is slow, and the vehicle starts in the direct connection mode even if the ND selection is performed. In some cases.

Therefore, as shown in FIG.
0c is the signal pressure Pso of the direct coupling clutch solenoid 190.
By deriving 1H / C, it is possible to reliably start from the power circulation mode even when the oil temperature is low.

FIG. 20 shows a third embodiment.
The supply pressure to the mode-fix valve 160 of the embodiment is replaced by the D range pressure Pd and the R range pressure Pr, instead of the control pressure Phc from the direct coupling clutch control valve 180 and the control pressure Plc from the power circulation clutch control valve 200. The other configuration is the same as that of the first embodiment.

The output port 180c of the direct coupling clutch control valve 180 is connected to the port 170 of the inhibitor valve 170.
c as well as the mode fix valve 16
0 port 160i.

The power circulation clutch control valve 200
The output port 200c is connected to the port 170f of the inhibitor valve 170 and also to the port 160d of the mode-fix valve 160.

In this case, the mode fix valve 1
The control pressure Plc regulated by the power circulation clutch control valve 200 from the output ports 160f and 160h of
Control pressure Ph regulated by direct coupling clutch control valve 180
c can be output to the ports 170e and 170h of the inhibitor valve 170 regardless of the tilt angle φ of the power roller.

Therefore, at the time of ND select or NR select, the power circulation mode clutch 9 can be gradually engaged, so that a shock at the time of engagement can be suppressed, and the clutch can be suppressed at the time of sudden braking. By reducing the transmission torque capacity of the engine, stall of the engine can be avoided.

FIG. 21 shows a fourth embodiment.
The mode fix valve 160 and the inhibitor valve 170 of the embodiment are applied only to the power circulation mode clutch 9 to control the control pressure Phc from the direct connection clutch control valve 180.
Is directly supplied to the direct connection mode clutch 10, and the other configuration is the same as that of the third embodiment.

The inhibitor valve 176 connects one of the port 176f communicating with the power circulating clutch control valve 200 and the port 176h communicating with the output port 166f of the mode fix valve 160 to the output port 176g according to the tilt angle φ. The spool 176a is provided with a cam 2 that rotates according to the tilt angle φ, similarly to the spool 170a of the first embodiment.
It is driven by the 80 cam grooves 280a.

On the other hand, the direct connection mode clutch 10 directly communicates with the output port 180c of the direct connection clutch control valve 180.

Also, the mode fix valve 166 is
The port 166f communicating with the port 176h of the inhibitor valve 176 is connected to the signal pressure P supplied to the port 166c.
power circulation clutch control valve 2 according to solH / C
A spool 166a is connected to one of a port 166d communicating with the output port 200c of the 00 and a drain port 166g.

The spool 166a has a lock mechanism that operates according to the tilt angle φ, similarly to the spool 160a of the first embodiment.

Further, the mode control valve 166 is connected to the shift control valve 24 via the oil passage 105.
6 is provided with a port 166k that communicates with the discharge port 246C of the
6k to the port 16 connected to the pump suction oil passage 104.
6l and one of the ports 166j connected to the port 230b of the manual valve 230.

The mode fix valve 16
6. The inhibitor valve 176 is the mode-fixed valve 160 and the inhibitor valve 170 of the first embodiment.
Works in the same way as

In this case, the power circulation mode clutch 9
The supply pressure to the power supply is regulated by the inhibitor valve 176 and the mode fix valve 166, so that the power circulation mode clutch 9 can be prevented from being engaged due to a failure or the like during traveling in the direct connection mode, and unintended gear shifting in the direct connection mode. Mode fix valve 1 while reliably preventing
66, the size of the inhibitor valve 176 can be reduced, the size and weight of the device can be reduced, and the arrangement of the oil passage can be simplified, and the degree of freedom in design can be improved.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of a continuously variable transmission with an infinite gear ratio showing an embodiment of the present invention.

FIG. 2 is a control conceptual diagram of a continuously variable transmission with an infinite speed ratio.

FIG. 3 is a conceptual diagram of a toroidal type continuously variable transmission.

FIG. 4 is an overall view of a hydraulic circuit diagram of the transmission control device.

FIG. 5 is an enlarged view of a hydraulic circuit diagram of the transmission control device, showing the first half thereof.

FIG. 6 is an enlarged view of a hydraulic circuit diagram of the transmission control device, showing the latter half thereof.

FIG. 7 shows a manual valve, (A) is a D range,
(B) shows the relationship between the spool and the port in the N range or the P range, and (C) shows the relationship in the R range.

FIG. 8 is a graph showing a relationship between a signal pressure and control pressures of a direct coupling clutch control valve and a power circulation clutch control valve.

FIG. 9 shows the positional relationship between the spool of the inhibitor valve and the mode fix valve according to the position of the cam, and FIG.
Is an inhibitor valve when the tilt angle is less than φcl,
(B) is an inhibitor valve when the tilt angle is φc,
(C) shows the inhibitor valve when the tilt angle exceeds φch, (D) shows the mode fix valve in the power circulation mode, and (E) shows the mode fix valve in the direct connection mode.

FIG. 10 is a map showing a relationship between a tilt angle φ and a CVT ratio ic.

FIG. 11 is a map showing a relationship between a CVT ratio ic and an IVT speed ratio e.

12A and 12B are schematic diagrams of a lock mechanism of a mode fix valve according to a position of a cam, wherein FIG. 12A shows a state where a spool and a slider are locked when the tilt angle exceeds φch, and FIG. 12B shows a tilt angle. Indicates the position where the slider is in sliding contact with the spool when φc is φc, and (C) indicates the position where the tilt angle is less than φcl and the slider comes out of the groove.

13A and 13B are schematic diagrams of a reverse torque control valve according to the position of a cam. FIG. 13A is a diagram illustrating a tilt angle φlo, FIG. 13B is a diagram illustrating a tilt angle φd, and FIG. Is φgnp,
(D) is when the tilt angle is φr, and (E) is when the tilt angle is φhi.
Are shown respectively.

FIG. 14 is a shift map of a target input shaft rotation speed Nin according to a vehicle speed VSP and an accelerator pedal depression amount APS, and a dashed line in the drawing indicates a CVT ratio ic.

FIG. 15 is a map of an operation mode according to an IVT speed ratio e and a CVT ratio ic.

FIG. 16 is a map showing a transmission torque of a power circulation mode clutch according to an IVT speed ratio e.

FIG. 17 is an enlarged view of a main part of a hydraulic circuit diagram of a transmission control device according to the second embodiment.

FIG. 18 is a flowchart illustrating an example of control performed by a shift control unit.

FIG. 19 shows a CVT ratio i according to a target input shaft rotation speed Nin.
cc map.

FIG. 20 shows the third embodiment, and is an overall view of a hydraulic circuit diagram of a shift control device.

FIG. 21 is an enlarged view of a main part of a hydraulic circuit diagram of the shift control device, showing the fourth embodiment.

FIG. 22 is a map showing a relationship between a speed ratio (CVT ratio) of a continuously variable transmission and a reciprocal of a unit speed ratio (IVT ratio).

[Explanation of symbols]

 Reference Signs List 1 unit input shaft 2 continuously variable transmission 3 constant transmission 5 planetary gear mechanism 9 power circulation mode clutch 10 direct connection mode clutch 80 transmission control controller 101 line pressure circuit 102 pilot pressure circuit 103 pilot valve 104 pump oil passage 107 D range pressure Circuit 108 R range pressure circuit 110i Suction port 110p Discharge port 120 Accumulator 135 Precess cam 160 Mode fix valve 163, 164 Groove 170 Inhibitor valve 180 Direct coupling clutch control valve 190 Direct coupling clutch solenoid 200 Power circulation clutch solenoid control valve 210 Power circulation clutch solenoid 230 Manual valve 231 Cam 240 Reverse torque cutoff valve 246 Shift control valve 260 Solenoid 261 Rod 63 solenoid 270 shuttle valve 280 cam 290 cam

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 3J552 MA09 MA29 NA01 PA02 PA03 PB02 QA06A SA44 SA49 SA51 SB03 SB12 SB35 TB01 TB13 VA11W VA22W VA32W VA36W VA52W VA62W VA74W VB01W VC01W VD01Z

Claims (5)

[Claims] 1. A continuously variable transmission capable of continuously changing a gear ratio and a constant transmission are respectively connected to a unit input shaft, and an output shaft of the continuously variable transmission and the constant transmission is connected to a planetary gear mechanism and a power source. An infinitely variable speed ratio transmission connected to the unit output shaft via a circulation mode clutch and a direct connection mode clutch, and supplying hydraulic pressure to at least one of the power circulation mode clutch and the direct connection mode clutch according to an operation state. A control device for a continuously variable transmission with an infinite gear ratio, comprising: a clutch control unit for controlling the power circulation mode and the direct connection mode by using the clutch control unit. Operating state determination means for determining whether or not the vehicle is in an operation mode switching region set in the vicinity of the power circulation mode clutch and the direct connection mode clutch. A valve capable of supplying hydraulic pressure to one or either of the two, and when the determination result is in the operation mode switching region, while driving the valve to supply hydraulic pressure to both the power circulation mode clutch and the direct connection mode clutch, When the determination result is not in the operation mode switching area,
A drive unit for driving the valve so as to supply oil pressure to only one of the power circulation mode clutch and the direct connection mode clutch according to an operation state, wherein the transmission ratio is infinite. Control device. 2. The valve according to claim 1, wherein the valve includes a hydraulic control valve capable of variably controlling a hydraulic pressure, and a switching valve for switching between a control pressure output from the hydraulic control valve and a line pressure. The switching valve is driven so as to output the control pressure when in the switching region, and the switching valve is driven so as to output the line pressure when not in the operation mode switching region. Item 2. The control device for an infinitely variable speed ratio transmission according to item 1. 3. The control device according to claim 1, wherein the driving unit is a cam that responds to a speed ratio of the continuously variable transmission. 4. The continuously variable transmission according to claim 2, wherein the cam drives the switching valve near a switching position corresponding to the operation mode switching region. apparatus. 5. The operation mode switching region is a region in which the speed ratio of the continuously variable transmission is smaller than the rotation synchronization point and exceeds the first speed ratio set on the rotation synchronization point side of the geared neutral point. The control of the continuously variable transmission according to claim 1, wherein the speed ratio between the unit input shaft and the unit output shaft is within a predetermined range including a rotation synchronization point. apparatus.