JPH03260462A - Line pressure control device of continuous transmission with v-belt - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a line pressure control device for a V-belt continuously variable transmission.

2. Description of the Related Art A conventional V-belt type continuously variable transmission is disclosed, for example, in Japanese Utility Model Application Publication No. 1-150256.

In this V-belt type continuously variable transmission, engine rotational power is input through a torque converter with a lock-up clutch.The torque converter increases torque, and in the event of lock-up, it can be connected directly to the engine. can.

By the way, when the torque increasing effect is activated, it is necessary to increase the line pressure by an amount corresponding to the increased torque to prevent the V-belt from slipping.

On the other hand, since the torque is not increased during lock-up, there is no need to increase the line pressure.

For this reason, in the conventional V-belt type continuously variable transmission described above, signal pressure for controlling the lock-up control valve or hydraulic pressure output from the lock-up control valve to the lock-up clutch is introduced to control the line pressure control valve. A switching valve that generates a control pressure is provided, and the line pressure is changed between lock-up and unlock-up using the line pressure control valve control pressure.

Problems to be Solved by the Invention However, in such a conventional line pressure control device for a V-belt type continuously variable transmission, the switching valve that produces the control pressure of the line pressure control valve is connected to the spool as shown in FIG. A signal pressure chamber a that is configured as a valve and introduces the signal pressure of the lockup control valve or the output pressure of the lockup IIJ control valve, a spring b that opposes the pressure of the signal pressure chamber a, and a line pressure introduction boat C. , a boat d that outputs the control pressure of the line pressure control valve, and a drain boat e.

The signal pressure used as the hydraulic pressure introduced into the signal pressure chamber a increases when the lock-up clutch is released, and when the output pressure of the lock-up control valve is used, the release pressure of the lock-up clutch is increased. is now used.

Therefore, in the above switching valve, when the lock-up clutch is engaged, the hydraulic pressure introduced into the signal pressure chamber a is lowered, so the spool f is moved to the left in the figure by the pressing force of the spring b. , boat d that outputs line pressure control pressure
is switched from the drain boat e to the line pressure introduction boat C for communication, so that the control pressure output from the boat d is increased.

For this reason, the line pressure regulated by the line pressure control valve is set to decrease as the control pressure increases, so if the line pressure is locked up and the engine is directly connected, the line pressure will decrease. become.

However, since the switching valve described above is simply provided with a spring b opposing the signal pressure, when the signal pressure is changed, the spool f is moved between the signal pressure and the spring b.
The object is suddenly moved once it reaches a state of equilibrium with the urging force of .

Therefore, even if the signal pressure is reduced smoothly as shown in FIG. 8, the line pressure is reduced all at once.

As a result, the driving load of the hydraulic pump that discharges the working fluid pressure changes rapidly, and this appears as a sudden torque change on the output shaft, which causes the driver to feel an unpleasant jerk. was there.

SUMMARY OF THE INVENTION In view of such conventional problems, it is an object of the present invention to provide a line pressure control device for a V-belt type continuously variable transmission that can smoothly change line pressure due to switching of a lock-up clutch. .

Means for Solving the Problems In order to achieve the above object, the first configuration of the present invention is to change the groove width by hydraulic actuation, and to connect the input shaft and the output shaft seamlessly via a circumferential V-belt. A driving pulley and a driven pulley that transmit torque in stages, a torque converter with a lock-up clutch that transmits the rotational force of the power source to the input shaft, and a line pressure that controls the line pressure supplied to the driving pulley and driven pulley. a pressure regulating valve; a lock-up control valve that controls engagement and release of the lock-up clutch; and a lock-up control valve that controls the lock-up control valve in order to continuously change the hydraulic pressure output from the lock-up control valve to the lock-up clutch. A V-belt continuously variable transmission comprising a signal pressure regulating means for continuously changing the signal pressure for the signal pressure regulating means, the signal pressure output from the signal pressure regulating means or the control fluid output from the lock-up control valve. A feedback hydraulic pressure regulating valve is provided which introduces pressure as a signal pressure and outputs a continuously changed control pressure, and the control pressure is supplied to the line pressure regulating valve as a signal pressure.

In addition, as a second configuration of the present invention, a drive pulley and a driven pulley whose groove width is changed by hydraulic pressure operation and which perform stepless torque transmission between the input shaft and the output shaft via the circumferential V-belt. a torque converter with a lock-up clutch that transmits the rotational force of the power source to the input shaft; a line pressure regulating valve that controls the line pressure supplied to the drive pulley and the driven pulley; A lock-up control valve that performs release control; and a signal pressure regulator that continuously changes the signal pressure for controlling the lock-up control valve in order to continuously change the hydraulic pressure output from the lock-up control valve to the lock-up clutch. In the V-belt continuously variable transmission comprising a pressure means, the signal pressure output from the signal pressure regulating means or the control hydraulic pressure output from the lock-up control valve is used as the signal pressure for the line pressure regulating valve. Constructed by supplying directly to

In the line pressure control device for a V-belt continuously variable transmission shown in the first configuration of the present invention, the control pressure of the line pressure regulating valve output from the feedback hydraulic pressure regulating valve is as follows. Since the signal pressure output from the signal pressure regulating means or the control hydraulic pressure output from the lock-up control valve is created as a continuously changing hydraulic pressure, it is possible to engage the lock-up clutch and At the time of release, the line pressure controlled by the line pressure regulating valve can be smoothly changed.

In the line pressure control device for a V-belt continuously variable transmission shown in the second configuration of the present invention, the signal pressure output from the signal pressure regulating means or the control fluid output from the lock-up control valve By directly supplying pressure as a signal pressure to the line pressure regulating valve, the signal pressure and control hydraulic pressure can be obtained as continuously changing hydraulic pressure, allowing smooth line pressure control by the line pressure regulating valve. It can be carried out.

Example Hereinafter, embodiments of the present invention will be described in detail based on the drawings.

That is, FIG. 1 is a block diagram showing a first embodiment of a line pressure control device for a V-belt continuously variable transmission according to the present invention, and as a V-belt continuously variable transmission whose speed is controlled by the line pressure control device. For example, a compound transmission shown in FIG. 2 is applied.

That is, the compound transmission IO shown in FIG. 2 above is a transmission in which a V-belt type continuously variable transmission and a gear type transmission are combined, and the rotational force transmission in the large torque region is not received by the gear type transmission. The rotational force in the small torque range is transmitted by a V-belt continuously variable transmission, and the output rotation of the engine E is transmitted to the drive shaft 14 as the input shaft of the transmission via the torque converter 12. communicated.

The torque converter 12 includes a pump impeller 12a
, a turbine runner 12b, and a stator 12c, and the torque converter I2 is provided with a lock-up clutch 16 that can directly connect the cover l2d integrated with the pump impeller 12a and the drive @I4.

A driven shaft 18 and an output shaft 20 are provided in parallel with the drive shaft 14, and a gear transmission path 22 is constituted by a gear train set to a predetermined reduction ratio between the drive shaft 14 and the output shaft 20. Output from the drive shaft 14 via the driven shaft I8 @
20, a V-belt transmission path 24 is constructed.

A hollow shaft 26 is fitted to the end of the drive shaft 14 so as to be relatively rotatable, and a forward drive gear 28 is fitted to the hollow shaft 26.
and a reverse drive gear 30 are fitted to be relatively rotatable, and a dog clutch 32 is provided between the hollow shaft 26 and the forward drive gear 28.

Further, there is a DR between the drive shaft 14 and the hollow shaft 26.
(drive/reverse) clutch 34 is provided, and the D
When the R clutch 34 is engaged, the drive shaft 14 and the hollow shaft 26 are rotated together, and the hollow shaft 26
The rotation is transmitted to the forward drive gear 28 when the dog clutch 32 is engaged on the F side (right side in the figure), while the rotation is transmitted to the forward drive gear 28 when the dog clutch 32 is engaged on the R side (left side in the figure). The time is transmitted to the reverse drive gear 30.

On the output shaft 20, a forward output gear 36 that is always engaged with the forward drive gear 28 is connected to the row one-way clutch 4.
A reverse output gear 44 is attached to the reverse drive gear 30 through an idler gear 42 and is always meshed with the reverse drive gear 30 through an idler gear 42.

The row one-way clutch 40 is locked when the rotational force is transmitted from the forward drive gear 28 toward the forward output gear 36, and is idly rotated when the rotational force is transmitted in the opposite direction. There is.

On the other hand, a drive pulley 52 consisting of a fixed sheave 46, a movable sheave 48, and a drive Boleyn ring chamber 50 is provided at the intermediate portion of the drive shaft 14, and a fixed sheave 54. A driven pulley 60 consisting of a movable sheave 56 and a driven boleyn ring chamber 58 is provided, and a V-belt 6 is provided between the driving pulley 52 and the driven pulley 60.
2 is being circulated.

Further, a forward driven gear 64 that is always meshed with the reverse output gear 44 is rotatably fitted to the driven shaft 18, and a high clutch 66 is connected between the driven shaft 18 and the forward driven gear 64. is provided, and when the high clutch 66 is engaged, the rotation of the driven shaft 18 is transmitted to the reverse output gear 44 via the forward driven gear 64.

Then, from the drive shaft 14 to the DR clutch 34, the hollow f
ill+26. Dog clutch 32. The gear transmission path 22 is constituted by a rotational force transmission path that reaches the output shaft 20 via the forward drive gear 28 and the forward output gear 36, and includes a rotational force transmission path from the drive shaft 14 to the drive boot 'J52. V-belt62. Driven pulley 60. Driven shaft 18. The above-mentioned V
A belt transmission path 24 is configured.

Note that the maximum reduction ratio provided by the V-belt transmission path 24 is set smaller than the reduction ratio obtained by the gear transmission path 22.

By the way, the output shaft 20 rotations beam reduction gear 68
The signal is transmitted to the ring gear 72 of the differential gear 70 via the differential gear 70, and the differential function of the differential gear 70 drives the tribe shaft 7474a.

In such a compound transmission 10, by releasing the DR clutch 34 and the high clutch 66, the drive shaft I
The rotational force transmission path from the output shaft 20 to the output shaft 20 is cut off, and at this time a neutral state is established, and the power of the engine 10 is not transmitted to drive wheels (not shown).

On the other hand, in the case of driving conditions that require a relatively large driving force, such as when starting up an uphill slope, the forward clutch 32 is engaged, and the high clutch 66 is released and the
By engaging the R clutch 34, the rotational force of the engine E output via the torque converter 12 is transmitted to the output shaft 20 and the differential gear 70 via the gear transmission path 22.

Therefore, at the time of starting, the rotational force is transmitted through the gear transmission path 22 having a large reduction ratio, so that a large driving force can be obtained.

Note that during the rotational force transmission via the gear transmission path 22,
Since the high clutch 66 is released, no rotational force is transmitted via the V-belt transmission path 24.

Next, when the operating conditions are favorable with a relatively small driving force,
By engaging the high clutch 66 in the operating state via the gear transmission path 22, the rotational force of the engine E is transmitted to the output shaft 20 and the differential gear 70 via the V-belt transmission path 24.

At this time, the output shaft 20 is rotated at a higher speed than the forward output gear 36, so even if the dog clutch 32 is engaged with the forward drive gear 28, the row one-way clutch 40 is in an idle state. In other words, it becomes a released state and interlock in the power transmission path is prevented.

When the rotational force is transmitted via this V-belt transmission path 24, the hydraulic pressure supplied to the driving Boleyn cylinder chamber 50 and the driven Boleyn ring chamber 58 is controlled to control the driving pulley 52 and the driven pulley 60. By changing the groove width, the gear ratio between the drive shaft 14 and the output shaft 20 can be varied steplessly in a gear ratio range smaller than that of the gear transmission path 22.

Next, when the transmission is placed in the reverse state, the DR clutch 34 is engaged and the dog clutch 32 is engaged with the reverse drive gear 30. At this time, the high clutch 66 is placed in the released state. Set.

When set to the backward state in this way, the rotational force of the drive axle load 4 is applied to the DR clutch 34. Hollow shaft 26. dog clutch 3
2. Reverse drive gear 30. The rotation of the output shaft 20 is transmitted to the output shaft 20 via the idler gear 42 and the reverse output gear 44, and since the idler gear 42 is interposed at this time, the rotation of the output shaft 20 is reversed from the forward rotation described above, and therefore the reverse rotation is performed. It will be done.

By the way, the above DR clutch 34. Engagement and release of the high clutch 66, switching of the dog clutch 32, drive pulley 60. The adjustment of the groove width of the driven pulley 68 and the engagement and release of the lock-up clutch 16 are controlled by the hydraulic pressure supplied from the hydraulic pressure control circuit shown in FIG. In this system, hydraulic pressure is created according to the driving conditions of the vehicle.

That is, in the above-mentioned hydraulic pressure control circuit, 100 is a manual valve that is switched by the driver's selection operation, 102 is a line pressure regulating valve that regulates line pressure according to operating conditions, and 10
Reference numeral 4 indicates a shift command valve that is switched and controlled via a step motor 106 according to operating conditions; 108 indicates a shift control valve that controls drive pulley pressure; 110 indicates a lock-up control valve that controls lock-up of the torque converter 12; and 112 indicates torque. Torque converter pressure control valve that regulates converter pressure;
114 is a throttle valve that regulates the pressure according to the throttle opening, and each of these valves is connected to the oil pump 1 as shown in the figure.
16.

When the manual valve 100 is switched to the forward travel range, D range pressure is output from the boat 100a, and when it is switched to the reverse travel range, R range pressure is output from the boat 100b.

The line pressure control valve 102 is controlled by the pump discharge pressure fed back to the boat 102a and the throttle pressure of the throttle valve 114 introduced to the boat 102b, and the line pressure is transferred from the boat 102c to the circuits L+, L- according to the running conditions. Discharge to.

The speed change command valve 104 has a rack 104a that is engaged with a pinion 106 of a step motor 106,
Moves in the axial direction by the rotation of the step motor 106,
This amount of movement is determined by the speed change control valve 10 via a link (not shown).
8.

In the speed change control valve 108, the line pressure introduction boat 10
8a and the output port 108b, and this control pressure (primary pressure) is supplied to the cylinder chamber 50 of the drive pulley 52 via the circuit 120 communicating with the output port 108b.
The groove width of the driving pulley 52 is controlled, that is, the speed change of the belt transmission path 24 is controlled.

Further, the control pressure of the speed change control valve 108 is controlled by the circuit 120.
The high clutch pressure is introduced as high clutch pressure into a supply circuit 122 branched from the supply circuit 122, and the high clutch pressure is supplied to the high clutch 66 via the supply circuit 122.

In the middle of the circuit 122, the circuit 122 is connected to the D range pressure that is output when the manual valve 100 is set to the forward range (upper half position in the figure).
A neutral valve 124 is provided, and the high clutch 66 is engaged when the neutral valve 124 is in communication.

Note that the neutral valve 124 is configured to shut off the supply circuit 122 (lower half position in the figure) when the gear is not in the forward gear, and drain the downstream side of the neutral valve 124, that is, the high clutch 66 side. .

Reference numeral 126 denotes a shift valve for shifting the shift fork of the upper S dog clutch 32, and the shift valve 126 has a piston + 26b formed at one end of the spool 126a on one side (right side in the figure) of the manual valve 100. port 100
The D range pressure output from a is supplied via the circuit 128, and the other side of the piston 126b (left side in the figure)
is supplied with R range pressure output from port 100b of manual valve 100 through circuit 130 when the reverse range (R range) is selected.

Therefore, when the forward gear is selected by the manual valve I00, the shift valve 126 is moved to the left in the figure, moving the shift fork to the left, and when the reverse gear is selected, the shift valve 126 is moved to the left in the figure. The shift fork is moved to the right in the figure, and as the shift foot is moved, the dog clutch 32 shown in FIG. 1 is switched.

Note that when the manual valve 100 is in the neutral position, the shift valve 126 is also set in the neutral position, and the dog clutch 32 is in the neutral state.

Further, the speed change control valve 108 is located in the middle of the circuit 130.
A reverse inhibitor valve 132 is provided which is switched by a control pressure from the circuit 1 when the control pressure is generated.
30 is communicated.

Incidentally, the shift valve 126 is formed with a port 126c into which the D range pressure is introduced and a port 126d into which the R range pressure is introduced, and an on/off valve 134 is connected between these boats 126c and 126d. A signal pressure port 126e is formed.

The on/off valve 134 is a valve that controls the engagement pressure supplied to the DR clutch 34, and after the shift valve 126 is reliably switched to the forward or reverse position, line pressure is supplied to the DR clutch 34. It looks like this.

On the other hand, the torque converter pressure is supplied to the torque converter 12 from the port 102d of the line pressure control valve 102, and the torque converter pressure output from the port 102d is passed through the converter pressure regulating valve 136. The signal is output to the lock-up control valve 110.

The lock-up control valve 110 has a port flQa for introducing the torque converter pressure regulated by the torque converter pressure control valve 136, a port 1iob for supplying the release pressure for releasing the lock-up, and a port 1iob for supplying the apply pressure for lock-up. Port 110c for supplying
is formed.

When the spool 110d is in the upper half position in the figure, the ports 110a and 110b are communicated with each other to output release pressure, and when the spool 110d is in the lower half position in the figure, the ports 110a and 110b are connected to each other to output release pressure. 110c is connected to output apply pressure.

The release pressure is supplied to the left side of the lock-up clutch 16 shown in FIG.
2d and released, the apply pressure is supplied to the right side of the lock-up clutch 16 in the figure, and the lock-up clutch 16 is pressed against the cover 12d and fastened.

In addition, the lock-up control valve 124 is
The torque converter pressure is fed back to the boat 110f, and the release pressure is fed back to the boat 110f.
Further, the working fluid that has circulated through the torque converter 12 is discharged to a drain circuit 138, and after being cooled through a cooler 140, this drain fluid is used for lubricating various parts.

By the way, the lock-up control valve 110 can be switched to the upper half position or the lower half position in the figure by a signal pressure supplied to a chamber 110g provided at the right end in the figure. It is generated by the lock-up solenoid 142 as a pressure regulating means.

The lock-up solenoid 142 introduces the torque converter pressure supplied from the torque converter pressure control valve +36, and controls the drain amount of the torque converter pressure by turning the lock-up solenoid 142 ON and OFF.
By performing M control, the signal pressure is obtained as a continuously changing signal pressure.

When the signal pressure generated by the lock-up solenoid 142 is increased, the lock-up control valve 110 is set to the lower half state in the figure, and when the lock-up clutch I6 is engaged and the signal pressure is decreased, the lock-up control valve 110 is set to the lower half state in the figure. The lock-up control valve 110 is set to the upper half state and releases the lock-up clutch I6.

Here, in this embodiment, the lock-up solenoid 142
A feedback hydraulic pressure regulating valve 150 is provided which similarly introduces the signal pressure of the lock-up control valve 110 generated in the signal pressure as a signal pressure and regulates the control pressure for controlling the line pressure. The output control pressure is introduced as a signal pressure to the line pressure control valve 102.

That is, the feedback hydraulic pressure regulating valve 150 is operated by the spool l which is biased to the left in the figure by the spring 150a.
50b, and the left end chamber 150 of the spool 150b in the figure.
The structure is such that a signal pressure generated by the lock-up solenoid 142 is introduced at point c in opposition to the pressing force of the spring 150a.

Further, the feedback hydraulic pressure regulating valve 150 is provided with a line pressure introduction port 150d communicating with the line pressure circuit, and an output port 150 through which the control pressure is output.
e is provided, and the control pressure of the output boat 150e is applied to the stepped portion l of the spool 150b via the boat 150f.
It is designed to be fed back to 50g.

On the other hand, the control pressure output from the output boat 150e is supplied as a signal pressure to the boat 102d of the line pressure control valve 102, and the pressure of the spring 102e of the line pressure control valve 102 and the throttle introduced into the boat 102c are It acts as a counter pressure to the pressure.

Therefore, when the control pressure introduced into the boat 102d is high, the spool 102g moves to the left in the figure, reducing the line pressure, while when the control pressure is low, the spool 102g moves to the right in the figure. Due to the movement, line pressure is increased.

In addition, the feedback hydraulic pressure regulating valve 150 is configured such that the output pressure of the boat 150e is fed back to the boat 150f, and this feedback pressure acts as a counterforce against the pressing force of the spring 150a, so that the signal pressure introduced into the chamber 150c is In response to the change, the control pressure output from the boat 150e will be changed slowly.

With the above configuration, in this embodiment, (1) the drive pulley 5 that revolves around the V-belt 62 constituting the belt transmission path 24;
2 is supplied with the drive pulley control pressure controlled by the speed change control valve 108 based on the line pressure, and the line pressure is directly supplied to the driven pulley 60. As a result, the drive pulley 52 and the driven pulley 60 groove width changes, that is,
(2) The pressing force of the belt 62 is determined by the line pressure.

By the way, when the lock-up clutch 16 is released, the converter function by the torque converter 12,
In other words, since a torque increasing function is generated, a large torque acts on the power train, and slippage is likely to occur between the driving pulley 52 and the driven pulley 60 and the V-belt 62.

On the other hand, in this embodiment, the lock-up clutch 1
When the lock-up control valve 6 is released, the lock-up control valve 11O is set to the lower half position in the figure, and a high signal pressure is generated in the lock-up solenoid 142 to maintain this state.

Therefore, a high signal pressure also acts on the left end chamber of the feedback hydraulic pressure regulating valve 150, and the feedback hydraulic pressure regulating valve 150 is set at the upper half position in the figure.

Therefore, the boat 150d and the boat 150e are cut off, and no control pressure is generated from the boat 150e.
No signal pressure acts on the boat 102e of the line pressure control valve 102, and the line pressure regulated by the line pressure control valve 102 becomes high.

Therefore, the driving pulley 52 and the driven pulley 60 and V
Slippage between the belt 62 and the belt 62 is reliably prevented, and sufficient torque can be transmitted.

On the other hand, when the lock-up clutch I6 is engaged, the engine is directly connected and the converter function of the torque converter 12 is not generated, so the torque acting on the power train is reduced and the slippage of the V-belt 62 is suppressed. .

When the lock-up clutch 16 is engaged, the lock-up control valve 110 is set to the upper half position in the figure, but at this time, no signal pressure is generated in the lock-up solenoid 142, so the feedback hydraulic pressure is adjusted. The pressure valve 150 is set at the lower half position in the figure.

Then, since the boat 150d and the boat 150e are communicated with each other at the lower half position of the feedback hydraulic pressure regulating valve 150, a high control pressure is generated in the boat 150e, and this is supplied to the boat 102e of the line pressure control valve 102. By doing so, the line pressure is set low.

By the way, in the feedback hydraulic pressure regulating valve I50,
When the signal pressure acting on the left end chamber 150c is changed by PWM control of the lock-up solenoid 142, the boat 1
The output pressure of 50e is applied to the spool 15 through the boat 150f.
Since the spring 150a acts as a counter pressure on the stepped portion 150g of the boat 150e, the control pressure output from the boat 150e changes slowly.

Therefore, as shown in Fig. 3, the lock-up solenoid 1
When the signal pressure generated at 42 is changed slowly, the line pressure regulated by the lock-up control valve 102 is also changed slowly, and the torque change is performed smoothly, causing discomfort to the power train. It is possible to prevent the occurrence of a sudden stop.

FIG. 4 shows a second embodiment of the present invention, in which the same components as those in the first embodiment are given the same reference numerals and redundant explanations will be omitted.

That is, in this embodiment, the release pressure of the lock-up clutch 16 output from the boat 110b of the lock-up control valve 110 is introduced into the left end chamber 150c of the feedback hydraulic pressure regulating valve 150 as a signal pressure.

That is, since the signal pressure supplied from the lock-up solenoid 142 to the lock-up control valve 110 is gradually changed by the 14M control, the release pressure used as the signal pressure is also gradually changed.

Therefore, as in the first embodiment, the control pressure output from the boat 150e of the feedback hydraulic pressure regulating valve 150 is changed slowly, so that the line pressure can be controlled slowly when the lock-up clutch 16 is switched. .

FIG. 5 shows a third embodiment of the present invention, in which the same components as in each of the above embodiments are given the same reference numerals and redundant explanations will be omitted.

That is, in this embodiment, the above-mentioned No. 1. The feedback hydraulic pressure regulating valve 150 provided in the second embodiment is eliminated, and the signal pressure generated by the lock-up solenoid 142 is directly supplied to the line pressure control valve 102.

The line pressure control valve 102 is provided with a port 102h so that the signal pressure acts in the same direction as the urging force of the spring 102f and the throttle pressure introduced into the port 102c.

Therefore, in this embodiment, when a high signal pressure is generated in the lock-up solenoid 142 when the lock-up clutch 16 is released, this signal pressure is supplied to the port 102h of the line pressure control valve 102 and adjusted in the direction of increasing the line pressure. On the other hand, when the signal pressure of the lock-up solenoid 142 is drained when the lock-up clutch 16 is engaged, no hydraulic pressure is supplied to the port 102h.

Since the signal pressure generated by the lock-up solenoid 142 is gradually changed when the lock-up clutch 16 is switched, the line pressure of the line pressure control valve 102 is also gradually changed, and the first. It is possible to perform the same functions as in the second embodiment.

Moreover, in this embodiment, the above-mentioned 1. Compared to the second embodiment, by eliminating the feedback hydraulic pressure regulating valve 150, the hydraulic pressure control circuit can be significantly simplified and miniaturized.

FIG. 6 shows a fourth embodiment of the present invention, in which the same components as in the third embodiment are given the same reference numerals and redundant explanations will be omitted.

That is, in this embodiment, the release pressure of the lock-up clutch 16 outputted from the port 110b of the lock-up control valve 110 is directly supplied to the port 102h of the line pressure control valve 102 as a signal pressure. .

That is, since the signal pressure supplied from the lock-up solenoid 142 to the lock-up control valve 110 is gradually changed by the PH control, the above-mentioned release pressure used as the signal pressure is also gradually changed. 3
As in the embodiment, the line pressure can be changed gradually when the lock-up clutch 16 is switched.

DETAILED DESCRIPTION OF THE INVENTION As described above, in the line pressure control device for a V-belt continuously variable transmission according to claim 1 of the present invention, the control pressure of the line pressure regulating valve output from the feedback hydraulic pressure regulating valve is Since the signal pressure output from the signal pressure regulating means or the control hydraulic pressure output from the lock-up control valve is created as a continuously changing hydraulic pressure, switching of the lock-up clutch is At times, the line pressure controlled by the line pressure regulating valve can be smoothly changed to prevent sudden torque changes, thereby eliminating unpleasant shocks and significantly improving vehicle ride comfort.

Further, in the line pressure control device for a V-belt type continuously variable transmission according to claim 2 of the present invention, the signal pressure output from the signal pressure regulating means or the control hydraulic pressure output from the lock-up control valve is controlled. By supplying the signal pressure directly to the line pressure regulating valve, the signal pressure and control hydraulic pressure are obtained as continuously changing hydraulic pressure, allowing smooth line pressure control when switching the lock-up clutch. In addition, the feedback hydraulic pressure regulating valve used in the structure of claim 1 can be abolished, thereby achieving various excellent effects such as simplifying the structure.

[Brief explanation of drawings]

Fig. 1 is a schematic configuration diagram of a hydraulic pressure control circuit showing a first embodiment of the present invention, and Fig. 2 shows an embodiment of a V-belt type continuously variable transmission to which the line pressure control device of the present invention is applied. Schematic configuration diagram,
Fig. 3 is a line pressure characteristic diagram during lock-up clutch switching obtained when using the device of the present invention, Fig. 4 is a schematic configuration diagram of a hydraulic pressure control circuit showing a second embodiment of the present invention, and Fig. 5 is a schematic configuration diagram of a hydraulic pressure control circuit showing a third embodiment of the present invention,
FIG. 6 is a schematic configuration diagram of a hydraulic pressure control circuit showing a fourth embodiment of the present invention, and FIG. 7 is a schematic configuration diagram of a switching valve used in a line pressure control device for a conventional V-belt type continuously variable transmission. FIG. 8 is a line pressure characteristic diagram when the lock-up clutch is switched using a conventional line pressure control device. 10...Compound transmission (V-held continuously variable transmission), 12
...torque converter, 14...drive shaft (input shaft)
, I6... Lock-up clutch, 20... Output shaft, 52... Drive pulley, 60... Driven pulley, 62
...V Held, 102...Line pressure control valve, 11O
...Lockup control valve, 142...Lockup solenoid (signal pressure regulating means), 150...Feedback fluid pressure regulating valve, E...Engine (power source). Figure 2 Figure 7 Figure 8 Time

Claims (2)

[Claims] (1) A driving pulley and a driven pulley whose groove width is changed by hydraulic operation and which transmits stepless torque between the input shaft and output shaft via the V-belt that is wound around it, and the rotational force of the power source is input. a torque converter with a lock-up clutch that transmits data to the shaft; a line pressure regulating valve that controls line pressure supplied to the driving pulley and the driven pulley; and a lock-up control valve that controls engagement and release of the lock-up clutch. , signal pressure regulating means for continuously changing a signal pressure for controlling the lock-up control valve, in order to continuously change the hydraulic pressure output from the lock-up control valve to the lock-up clutch; In the V-belt type continuously variable transmission, the control pressure is continuously changed by introducing the signal pressure output from the signal pressure regulating means or the control hydraulic pressure output from the lock-up control valve as the signal pressure. A line of a V-belt continuously variable transmission characterized in that the line pressure is smoothly changed by providing a feedback hydraulic pressure regulating valve that outputs a feedback fluid pressure regulating valve and supplying the control pressure to the line pressure regulating valve as a signal pressure. Pressure control device. (2) Drive pulley and driven pulley, whose groove width is changed by hydraulic pressure, and which transmit stepless torque between the input shaft and output shaft via the V-belt that is wound around it, and input the rotational force of the power source. a torque converter with a lock-up clutch that transmits data to the shaft; a line pressure regulating valve that controls line pressure supplied to the driving pulley and the driven pulley; and a lock-up control valve that controls engagement and release of the lock-up clutch. In order to continuously change the hydraulic pressure output from the lock-up control valve to the lock-up clutch, a signal pressure regulating means for continuously changing the signal pressure for controlling the lock-up control valve is provided. In the V-belt type continuously variable transmission, the signal pressure output from the signal pressure regulating means or the control hydraulic pressure output from the lock-up control valve is directly supplied as a signal pressure to the line pressure regulating valve, A line pressure control device for a V-belt continuously variable transmission characterized by smoothly changing line pressure.