JP3361767B2 - Hydraulic control device and lock-up clutch control device using this hydraulic control device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hydraulic control device and a lockup clutch control device using the hydraulic control device , and more particularly to a lockup clutch for a fluid coupling used in an automatic transmission for vehicles. Regarding the control device.

[0002]

2. Description of the Related Art Conventionally, a fluid coupling such as a torque converter has been used in an automatic transmission for a vehicle. This fluid coupling has a lockup clutch for mechanically engaging and disengaging its input side and output side. Is provided. The control device for the lock-up clutch controls the hydraulic pressure of the release oil chamber while the lock-up shift valve that switches the hydraulic pressure supply to the engagement oil chamber and the release oil chamber and the hydraulic pressure is being supplied to the engagement oil chamber. Lock-up control valve and a duty solenoid valve that outputs hydraulic pressure according to the duty ratio that controls the lock-up control valve are provided, and the lock-up state is achieved by minimizing the hydraulic pressure in the release oil chamber. By adjusting the oil pressure in the chamber to a predetermined range, the lockup clutch is put in a slip state, and by maximizing the oil pressure in the release oil chamber, the lockup clutch is released.

Generally, during steady operation without gear shifting or in a predetermined operating range of medium and high speeds, the lockup clutch is locked, and in a predetermined operating range of low load and low speed, engine output speed and turbine The slip control is performed while controlling the differential pressure so that the rotational speed difference between the rotational speeds becomes a substantially constant value. As described above, in the lockup control valve, the hydraulic pressure of the release oil chamber is controlled by the duty solenoid valve. However, in the conventional lockup clutch control device, as shown by the characteristic line A in FIG. The oil pressure in the release oil chamber continuously decreases as the ratio increases, and when the duty ratio reaches almost 100%, the oil pressure in the release oil chamber becomes minimum and the lockup state is established.

As described above, in the conventional lockup clutch control device, when the duty ratio of the solenoid valve reaches almost 100%, the hydraulic pressure in the release oil chamber is minimized and the lockup state is established. For,
There is a problem that the rate of change of the oil pressure in the release oil chamber with respect to the duty ratio (gradient of the characteristic line A) becomes large, and it is difficult to precisely control the oil pressure in the release oil chamber during slip control.

In order to solve such a problem, when the slip-up control of the lock-up clutch is performed, the rate of change of the oil pressure in the released oil chamber with respect to the duty ratio of the duty solenoid valve is made smaller than in other cases. One has been proposed (Japanese Patent Laid-Open No. 5-180333). That is, when the slip control is deviated, another valve for applying an additional hydraulic pressure to the lockup control valve is provided to stop the pressure adjusting function of the lockup control valve.

[0006]

However, the provision of such another valve has the drawbacks that the hydraulic circuit becomes complicated and large, and the cost increases.

An object of the present invention is to control hydraulic pressure within a predetermined range of signal pressure with high accuracy and to omit a special valve for stopping the pressure regulating function.
It is to provide a device . Another object of the present invention is to provide a lock-up clutch control device capable of highly accurately and stably performing slip control of the lock-up clutch and omitting a special valve for stopping the pressure adjusting function. .

[0008]

The above object is achieved by the invention described in claim 1. That is, the invention according to claim 1 is formed with a valve body, a spool slidably arranged in the valve body, and one end side of the valve body, and the first signal for urging the spool in one direction. A first signal port to which pressure is input, and a biasing means provided on the other end side of the valve body for biasing the spool in the opposite direction,
An input port formed in an intermediate portion of the valve body, to which the input pressure is input, a drain port formed at a position closer to the other end of the valve body than the input port, and formed between the input port and the drain port, The output port is connected to the input port or the drain port by the movement of the spool to output the output pressure, and the output port is fitted to the end portion of the spool facing the first signal port. And a feedback chamber which is formed between the spool and the plug and through which the output pressure is guided through a communication hole provided inside the spool.
Control valve and the first signal port above.
Continuously variable control of the first signal pressure by electric signal
Equipped with an effective solenoid valve, the first signal pressure is predetermined
In the region lower than hydraulic pressure, the feedback chamber
The plug and the spool are axially separated from each other, and the first
The first signal acting on the end of the spool facing the signal port
The force of pressure and the spool facing the feedback chamber
The sum of the force due to the output pressure acting on the part and the urging means
The output pressure is adjusted so as to balance with the force of
In the region where the signal pressure is higher than the specified oil pressure, the above feedback
The plug and spool in the chamber make axial contact and output
At the position where the port and the drain port communicate with each other, the spoo
Is a hydraulic control device characterized in that

The biasing means may be constituted by only a spring, or a second signal port is formed on the other end side of the valve body as in claim 2, and the second signal port is inputted. It may include the second signal pressure. In particular,
If the second signal pressure is input to the second signal port,
Since the maximum output pressure can be set freely by the signal pressure, the degree of freedom in control can be increased.

Since the output pressure is guided to the feedback chamber through the communication hole of the spool, the spool is pushed in one direction, and is pushed by the biasing means so as to face the spool. That is, in the state where the first signal pressure is not input to the first signal port, the output pressure is adjusted to the hydraulic pressure according to the biasing means.
When the first signal pressure input to the first signal port gradually rises, the first signal pressure acts on a part of the end surface of the spool and the end surface of the plug. However, while the output pressure introduced to the feedback chamber is higher than the first signal pressure, the plug is pressed to the terminal position of the first signal port. for that reason,
The output pressure acts on the portion of the spool facing the feedback chamber, and the first signal pressure acts on the portion of the spool facing the first signal port. The output pressure is the resultant force of these hydraulic pressures and the biasing means.
The pressure is adjusted to a hydraulic pressure that balances with the force of. Therefore,
The output pressure decreases with a small gradient as the first signal pressure increases. That is, the rate of change of the output pressure that decreases with an increase in the first signal pressure can be reduced, so that a highly accurate pressure adjusting function can be exhibited. When the first signal pressure becomes higher than the output pressure, the output pressure acting on the feedback chamber is abolished by the contact of the plug with the spool, and the spool is driven by the first signal pressure acting on a part of the end surface of the spool and the end surface of the plug. Is pressed. As a result, the spool moves to the end position against the biasing means, the output port and the drain port communicate with each other, and the output pressure immediately drops to the minimum pressure. That is, the pressure regulating function of the control valve is stopped.

In the present invention, since the control valve itself is provided with the pressure regulating function, it is not necessary to use another valve for regulating the pressure as in the prior art. Therefore, if this control valve is applied to a lockup clutch control device or the like, the hydraulic circuit can be simplified and downsized, and the cost can be reduced.

The hydraulic control system of the present invention can be applied to a lockup clutch control system as described in claim 3. That is, a lockup shift valve that mechanically engages and disengages the input side and the output side of the fluid coupling to switch the hydraulic pressure supply to the engagement oil chamber and the release oil chamber of the lockup clutch, and the hydraulic pressure is supplied to the engagement oil chamber. In a lock-up clutch control device including a lock-up control valve for controlling the hydraulic pressure of the release oil chamber and a solenoid valve for outputting a solenoid pressure for controlling the lock-up control valve, The valve is the control valve according to claim 1, and the solenoid valve is according to claim 1.
And a second signal port to which the hydraulic pressure of the fastening oil chamber is input so as to bias the spool in the opposite direction. The port is a lockup clutch control device characterized in that it is connected to a release oil chamber.

The control valve of the present invention is not limited to the lockup clutch control device, but can be applied to other hydraulic control devices such as hydraulic control of friction engagement elements of an automatic transmission. In that case, the first signal pressure is not limited to the solenoid pressure, and various signal pressures can be used. Even when using solenoid pressure, a linear solenoid valve may be used in addition to the duty solenoid valve.

[0014]

1 shows an example of a lockup clutch control device according to the present invention. The torque converter 1 of the automatic transmission includes a pump impeller 2 on the input side, a turbine runner 3 on the output side, and a stator 5 , and mechanically disengages the pump impeller 2 and the turbine runner 3 from each other. A lockup clutch 4 is provided. On the right side of the lock-up clutch 4 in the figure, the fastening oil chamber 4
a and an open oil chamber 4b are formed on the left side.

This lock-up clutch control device is generally composed of a regulator valve 10, a lock-up shift valve 20, a lock-up control valve 30, and an on / off valve.
The solenoid valve 40 is off-controlled and the solenoid valve 50 is duty-controlled. The source pressure Psm of the solenoid valves 40 and 50 is a constant pressure supplied by a pressure regulating valve (not shown).

The regulator valve 10 is a valve for adjusting the discharge pressure of the oil pump 11 to a predetermined line pressure (original pressure) P _L , and is provided with a spool 13 biased to the left in the figure by a spring 12. . The discharge pressure of the oil pump 11 is input to the input port 14 which also serves as an output port, and the drain port 15 is connected to the suction port of the oil pump 11. The line pressure P _L is guided to the feedback port 16 at the left end through the communication hole 13a formed in the spool 13, and the line pressure P _L is adjusted to a hydraulic pressure corresponding to the spring 12. When the lockup clutch control device is combined with the hydraulic control device for the automatic transmission, the regulator valve 10 may be provided separately from the regulator valve for adjusting the line pressure of the hydraulic control device for the automatic transmission.

The lock-up shift valve 20 is a valve for switching the hydraulic pressure supply to the engagement oil chamber 4a and the release oil chamber 4b of the lock-up clutch 4, and the spool 22 biased rightward in the drawing by a spring 21. I have it.
The first solenoid pressure P _SOL1 is supplied to the signal port 23 at the right end from the first solenoid valve 40, which is controlled to be turned on / off, and pushes the spool 22 to the left. The line pressure P _L is input from the regulator valve 10 to the port 24, the first output port 25 is connected to the engagement oil chamber 4 a of the lockup clutch 4, and the oil pressure in the engagement oil chamber (hereinafter referred to as the apply pressure P _A). ) Is output. The second output port 26 is connected to the release oil chamber 4b of the lockup clutch 4. In addition, from the lock-up control valve 30 to the port 27, the oil pressure of the release oil chamber 4b (hereinafter, the release pressure P
(Called _R ) is input.

When the first solenoid valve 40 is off, the first solenoid pressure P _SOL1 does not occur and the spool 2
2 is at the right end position by the spring 21. Therefore, the input port 24 and the second output port 26 communicate with each other,
The line pressure P _L is the release oil chamber 4b of the lockup clutch 4.
Is supplied to the lockup clutch 4 and the lockup clutch 4 is released. Then, the oil that has passed through the lockup clutch 4 is returned to the first output port 25 through the fastening oil chamber 4a, and is supplied to the lubrication unit via the cooler.

On the other hand, when the first solenoid valve 40 is turned on, the first solenoid pressure P _SOL1 is input to the signal port 23, and the spool 22 is pushed against the spring 21 to the left end position. Therefore, the input port 24 and the first output port 25 communicate with each other, and the line pressure P _L is supplied to the engagement oil chamber 4a of the lockup clutch 4 as the apply pressure P _A. At this time, the lock-up clutch 4 of the release oil chamber 4b lockup shift valve 20 ports 26 and 27 lock-up control release pressure P _R from the valve 20 through the is input, in response to the release pressure P _R The engagement state of the lockup clutch 4 changes.

The lockup control valve 30 is a control valve according to the present invention, and is a valve for controlling the release pressure P _R while the hydraulic pressure is being supplied to the engagement oil chamber 4a of the lockup clutch 4. As shown in detail in FIG. 2, the control valve 30 includes a valve body 31, a spool 32 at the center thereof, a first plug 33 on the left side in the figure, and a second plug 34 on the right side. It is urged to the left in the figure by 35. Here, the pressure receiving area of the first plug 33 and the pressure receiving area of the second plug 34 are set to be equal.
The second plug 34 can be omitted by integrating it with the spool 32.

A first signal port 31a to which the solenoid pressure P _SOL2 is input from the second solenoid valve 50 whose duty is controlled is formed on the left end side of the valve body 31, and the cylindrical left end of the spool 32 is formed by the solenoid pressure P _SOL2 . The part 32a is pushed to the right. _A second signal port 31b to which the apply pressure P _A is input is formed on the right end side of the valve body 31, and the apply pressure P _A pushes the spool 32 leftward via the second plug 34. An input port 31c to which the line pressure P _L is input is formed in the middle of the valve body 31, and a drain port 31d is formed on the right side of the valve body 31 with respect to the input port 31c. An output port 31e, which selectively communicates with the input port 31c or the drain port 31d by the movement of the spool 32 and outputs the release pressure P _R , is formed between the input port 31c and the drain port 31d. The first plug 33 is slidably fitted in the cylindrical left end portion 32a of the spool 32, and is movable to the right in the drawing upon receiving the solenoid pressure P _SOL2 . The spool 32 is provided between the spool 32 and the first plug 33.
Release pressure P through a communication hole 32b provided inside
A feedback chamber 36 into which _R is guided is formed.

The operation of the control valve 30 will be described with reference to FIG. The release pressure P _R, which is the output pressure, is guided to the feedback chamber 36 through the communication hole 32b of the spool 32, so that the spool 32 is pushed to the right, and facing the spring 35 and the second signal port 31b. The spool 32 is pushed to the left by the apply pressure P _A input to. That is, when the solenoid pressure P _SOL2 is not input to the first signal port 31a, the spool 32 releases the release pressure P _R and the spring 3
5 and the apply pressure P _A are adjusted so that the release pressure P _R is adjusted to a predetermined hydraulic pressure. In addition,
Spring 35 and apply pressure compared to line pressure P _L
If the resultant force of P _A is set high, the spool 3
2 is pushed all the way to the left as shown in the upper half of Fig. 2,
The source pressure P _R becomes equal to the line pressure P _L.

When the solenoid pressure P _SOL2 input to the first signal port 31a gradually rises in accordance with the duty ratio, the solenoid pressure P _SOL2 becomes the left end 32a of the spool 32.
And acts on the first plug 33 as an urging force in the right direction. However, while the release pressure P _R guided to the feedback chamber 36 is higher than the solenoid pressure P _SOL2 , the first plug 33 is pressed to the left end position, so that the portion of the spool 32 facing the feedback chamber 36 is located. Is the release pressure P _R , and the solenoid pressure P _SOL2 acts on the portion facing the left end 32a of the spool 32.
_The release pressure P _R decreases with a small gradient as _SOL2 rises. That is, the rate of change of the release pressure P _R that decreases as the solenoid pressure P _SOL2 increases can be reduced, so that highly accurate slip control of the lockup clutch 4 can be performed.

Eventually, the solenoid pressure P _SOL2 is released pressure P
_When it becomes higher than _R , the first plug 33 comes into contact with the spool 32 and the hydraulic pressure acting on the feedback chamber 36 is invalidated. That is, the left end portion 32a of the spool 32 and the first
Solenoid pressure P acting on both pressure receiving areas of the plug 33
Since the spool 32 is pushed rightward by _SOL2 , the spool 32 moves to the right end, the output port 31e and the drain port 31d communicate with each other, and the release pressure P _R decreases to the minimum pressure. That is, the pressure regulating function of the control valve 30 is stopped. As a result, the lockup clutch 4
Is in a completely fastened state.

As is apparent from FIG. 3, in the present invention (characteristic line B), the release pressure P _R is smaller than that in the conventional case (characteristic line A) when the duty ratio, which is the duty control range, is in the range of 20 to 50%. The slope can be reduced to less than half. Therefore, the slip control of the lockup clutch 4 can be performed with high accuracy, and the shock at the time of engaging the lockup clutch 4 can be eliminated.

Although only one characteristic line B is drawn in FIG. 3,
This is the line pressure P _L generated by the regulator valve 10.
Is a constant pressure, if regulator valve 1
If 0 can generate a plurality of stages of line pressure P _L , a plurality of characteristic lines B can be drawn. These characteristic lines B are parallel to each other, that is, the gradient is constant. In the region of low duty ratio (0 to 20% in FIG. 3),
The upper limit of the release pressure P _R is limited to a predetermined pressure (6.8 kgf / cm ^{2 in} FIG. 3) by the line pressure P _L.

FIG. 4 shows a second embodiment of the control valve according to the present invention. This control valve 60
A valve body 61, a spool 62 slidably arranged in the valve body 61, a spring 63 for biasing the spool 62 to the left, and a shaft portion 62a formed at the left end of the spool 62. And a cylindrical plug 64 that is inserted into the. The first signal port 61a to which the solenoid pressure P _S is input is provided at the left end of the valve body 61.
Is formed, and the line pressure P is formed in the middle portion of the valve body 61.
An input port 61b to which _L is input, an output port 61c that outputs the output pressure P _R, and a drain port 61d are sequentially formed to the right. A feedback chamber 65 is formed between the spool 62 and the plug 64, and the output pressure P _R is transmitted through the communication hole 62b of the spool 62 to the feedback chamber 65.
Have been led to.

[0028] In the case of the control valve 60 of this embodiment, as in the control valve shown in FIG. 2, until the solenoid pressure P _s is the output pressure P _R and the same pressure, the shaft section with increasing solenoid pressure P _s The output pressure P _R decreases with a gradient according to the pressure receiving area of 62a. When the solenoid pressure P _s becomes higher than the output pressure P _R , the spool 62 moves to the right end position and the output pressure P _R is drained.

The control valve of the present invention is shown _in FIGS.
The structure is not limited to the one shown in FIG. 1, and various modifications can be made. For example, the spring may be omitted as the urging means for urging the spool in one direction, and only the signal pressure may be used. Further, the first signal pressure is not limited to the solenoid pressure, and other signal pressure may be used.

[0030]

As is apparent from the above description, claim 1
According to the hydraulic control device of the present invention , the plug is slidably fitted to one end of the control valve facing the first signal port of the spool, and is provided inside the spool between the spool. Since the feedback chamber in which the output pressure is guided through the communication hole is formed, the rate of change of the output pressure, which decreases as the first signal pressure increases, can be reduced , and a highly accurate pressure adjusting function can be exhibited. . Then, when the first signal pressure becomes higher than the output pressure, the spool and the plug are integrally pushed by the first signal pressure, so that the feedback chamber is invalidated and the pressure adjusting function is stopped. Therefore, it is not necessary to provide a special valve for stopping pressure regulation.

According to the lock-up clutch control device of the third aspect, by using the control valve of the first aspect as the lock-up control valve, slip control of the lock-up clutch can be performed with high accuracy and stability. The pressure regulating function can be stopped without using a special valve. Therefore, the hydraulic circuit of the lockup clutch can be simplified and downsized.

[Brief description of drawings]

FIG. 1 is a circuit diagram of an example in which a hydraulic control device of the present invention is applied to a lockup clutch control device.

FIG. 2 is a structural diagram of an example of a control valve.

FIG. 3 is a characteristic diagram of each hydraulic pressure with respect to a duty ratio of a solenoid valve.

FIG. 4 is a structural view of another embodiment of the control valve.

[Explanation of symbols]

30 Lockup Control Valve 31 Valve Body 31a First Signal Port 31b Second Signal Port 31c Input Port 31d Drain Port 31e Output Port 32 Spool 33 Plug 35 Spring (Biasing Means) 36 Feedback Chamber P _A Apply Pressure (Biasing Means) P _R release pressure (output pressure) P _L line pressure (input pressure)

Front page continued (58) Fields surveyed (Int.Cl. ⁷ , DB name) F16H 59/00-61/64 F16H 63/00-63/48 F16K 11/00 F16K 11/07

Claims (3)

(57) [Claims] 1. A valve body, a spool slidably disposed in the valve body, and one end of the valve body, the first signal pressure being input to urge the spool in one direction. 1 signal port, and a biasing means that is provided on the other end side of the valve body and biases the spool in the opposite direction,
An input port formed in an intermediate portion of the valve body, to which the input pressure is input, a drain port formed at a position closer to the other end of the valve body than the input port, and formed between the input port and the drain port, The output port is connected to the input port or the drain port by the movement of the spool to output the output pressure, and the output port is fitted to the end portion of the spool facing the first signal port. And a feedback chamber which is formed between the spool and the plug and through which the output pressure is guided through a communication hole provided inside the spool.
Control valve and the first signal pressure input to the first signal port to an electric signal.
With a solenoid valve that can be continuously variably controlled by
In the region where the first signal pressure is lower than the predetermined hydraulic pressure,
The plug and spool in the feedback chamber are axially separated.
The end of the spool facing the first signal port
Force due to the first signal pressure acting on the part and the above feedback
The force due to the output pressure acting on the part of the spool facing the chamber
The output pressure is adjusted so that the sum of the
In the region where the pressure is regulated and the first signal pressure is higher than the predetermined hydraulic pressure,
The plug and spool in the feedback chamber are in contact with each other in the axial direction.
Touch it so that the output port and drain port are in communication.
A hydraulic control device characterized in that the spool is operated.
Place 2. A second signal port is formed on the other end side of the valve body, and the urging means includes a second signal pressure input to the second signal port. The described hydraulic control device . 3. A lock-up shift valve for switching the hydraulic pressure supply to the engagement oil chamber and the release oil chamber of a lock-up clutch for mechanically engaging and disengaging the input side and the output side of the fluid coupling,
Lock-up clutch control including a lock-up control valve that controls the hydraulic pressure in the release oil chamber while the hydraulic pressure is being supplied to the engagement oil chamber, and a solenoid valve that outputs a solenoid pressure for controlling the lock-up control valve In the device, the lock-up control valve is the control valve according to claim 1, and the solenoid valve is the solenoid valve according to claim 1.
And a second signal port for inputting the oil pressure of the fastening oil chamber to urge the spool in the opposite direction is provided on the other end side of the control valve. A lockup clutch control device characterized by being connected to a room.