JPH10301637A - Electromagnetic proportional control valve - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electromagnetic proportional control valve which omits a switching valve and shows both performance of 'high pressure maintenance' and 'controllability at low pressure' with a simple oil hydraulic circuit. SOLUTION: In an electromagnetic proportional control valve which is provided with an input port 1, an output port 2, a drain port 3, a feedback port 4, a spool 10, a spring 12 and a solenoid 14, controls the position of the spool with balance of spring force, the force by feedback pressure and the electromagnetic force of the solenoid and generates prescribed control pressure at the port 2, the spool is moved to a position where the feedback port is fully closed by making current flow to the solenoid 14 in a direction that is reverse to a normal direction at the time of high pressure maintenance.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an electromagnetic proportional control valve mainly used as a clutch hydraulic pressure control device for an automatic transmission.

[0002]

2. Description of the Related Art The performance required of a clutch hydraulic pressure control device for an automatic transmission includes: (a) holding a high pressure (capable of holding a high pressure in order to prevent slippage when a friction element is fastened); High controllability (the ability to control the hydraulic pressure with high sensitivity in a low pressure range in order to adjust the slip amount and torque capacity when changing the engagement state of the friction element (at the time of shifting)).

Conventionally, when an electromagnetic proportional control valve is directly used for clutch pressure control as a clutch hydraulic pressure control device for an automatic transmission, priority is given to "high pressure holding" in (a) and a high pressure type as shown in FIG. If the characteristics are set, the current-hydraulic sensitivity in the low-pressure range becomes too high, and the controllability decreases. or,
When the controllability in the low pressure range (b) is prioritized and the characteristics of the low pressure type as shown in FIG. 8 are adopted, there is a problem that the high pressure cannot be maintained.

FIG. 9 is a schematic view of a general electromagnetic proportional control valve.

The electromagnetic proportional control valve 100 has an input port 101 to which a supply pressure from a hydraulic pressure source is input, and an output port 10 to output a control pressure toward a control target (clutch).
2, a drain port 103, a feedback port 104 to which the control pressure is fed back, a spool 110 for opening / closing and opening control of each port, and a spool 1
Spring (biasing means) 1 for biasing 10 toward one side in the moving direction
12 and a solenoid 114 that moves the spool 110 against the force of the spring.

In the electromagnetic proportional control valve 100, the spring 11
2, the position of the spool 110 is controlled by the balance between the force acting on the spool 110 by the hydraulic pressure of the feedback port 104 and the force acting on the spool 110 by the electromagnetic force of the solenoid 114.
The control pressure generated at the output port 102 is determined by adjusting the communication ratio between the first port 1, the output port 102, and the drain port 103. In this case, no matter how high the pressure is applied to the input port 101, the upper limit of the control pressure is determined by the force of the spring 112 and the area of the feedback pressure receiving surface.

Therefore, conventionally, a configuration in which a switching valve is separately provided is adopted in order to achieve both "high pressure holding" and "controllability in a low pressure range".

FIG. 10 and FIG. 11 are diagrams showing respective examples. In both figures, the switching valves 120 and 140 are in the low pressure control state, and the state changes to the high pressure holding state by applying the switching signal. In the example of FIG. 10, the control pressure is supplied to the clutch through the electromagnetic proportional control valve 100 at the time of low pressure control, but the high pressure is maintained by switching the position of the switching valve 120 to bypass the electromagnetic proportional control valve 100. The direct supply pressure is output to the clutch as a control pressure. FIG.
In the example, during low pressure control, the control pressure is supplied to the clutch through the electromagnetic proportional control valve 100, but when high pressure is maintained,
By switching the position of the switching valve 140, feedback is cut, and the electromagnetic proportional control valve 100 is controlled by the force of a spring.
Is fully opened to output a high control pressure.

[0009]

As described above, conventionally, the electromagnetic proportional control valve 100 is separately provided with switching valves 120 and 140.
Therefore, there is a problem that the hydraulic circuit becomes complicated and the manufacturing cost and the component cost increase.

The present invention has been made in view of such a conventional problem, and does not require a switching valve, and has a simple hydraulic circuit to achieve both "high pressure holding" and "controllability in a low pressure range". An object of the present invention is to provide an electromagnetic proportional control valve capable of exhibiting performance and thereby reducing manufacturing costs and component costs.

[0011]

According to the present invention, there is provided an input port to which a supply pressure from a hydraulic pressure source is input, an output port to output a control pressure to a controlled object, a drain port, and the control pressure being fed back. Feedback port
A spool for opening / closing and controlling the opening of each port, an urging means for urging the spool to one side in the moving direction, and a solenoid for moving the spool against the urging force of the urging means. The urging force of the urging means, the force acting on the spool by the hydraulic pressure of the feedback port,
The position of the spool is controlled by the balance of the force acting on the spool by the electromagnetic force of the solenoid, the communication ratio between the input port, the output port, and the drain port is adjusted to generate a predetermined control pressure at the output port. In the proportional control valve, by providing a means for moving the spool to a position where the feedback port is fully closed,
The present invention has solved the above problem.

In this electromagnetic proportional control valve, during normal proportional control, the control pressure is fed back to the feedback port. Therefore, when the control pressure is too large, the spool moves in a direction to decrease the control pressure, and when the control pressure is too small, the spool moves in a direction to increase the control pressure. Controlled to match pressure. On the other hand, when the high pressure is maintained, the spool is forcibly moved to fully close the feedback port so that the control pressure is not fed back. Then, since the spool moves in the direction of increasing the control pressure, the supply pressure is output as it is as the control pressure, and the control pressure becomes maximum.

That is, in the prior art, the feedback port has not been fully closed by the spool (because it is necessary to feed back the control pressure from the start of applying the hydraulic pressure), but in the present invention, the spool is moved only when the high pressure is maintained. This intentionally closes the feedback port completely, thereby maximizing the control pressure.

As means for moving the spool to a position where the feedback port is fully closed, means for supplying a current to the solenoid in a direction opposite to that in the normal proportional control may be provided. 2). Alternatively, a second solenoid may be provided separately from the solenoid (claim 3).

[0015]

Embodiments of the present invention will be described below with reference to the drawings.

FIGS. 1 to 4 are sectional views showing the electromagnetic proportional control valve V1 of the first embodiment. FIG. 1 shows a state when power is not supplied, FIG. 2 shows a state during normal control (during pressure adjustment), and FIG. 4 shows a state at the time of maximum current (fully closed), and FIG. 4 shows a state at the time of holding high voltage (at the time of reverse energization).

First, the configuration will be described with reference to FIG.

This electromagnetic proportional control valve V1 is connected to an input port 1 to which the supply pressure is input, similarly to a normal electromagnetic proportional control valve.
And an output port 2 for outputting a control pressure and a drain port 3
And a feedback port 4 to which a control pressure is fed back, and a spool 1 for controlling opening / closing and opening of each port
0, a spring (biasing means) 12 for urging the spool 10 in the R direction in the figure, and a solenoid for moving the spool 10 in the L direction in the figure (R and L are opposite directions) against the force of the spring 12 1
4 is provided. The solenoid 14 includes a coil 15 and a mover 16. The port denoted by EX is connected to the drain.

The spool 10 has first, second and third lands 10a, 10b and 10c. The first land 10a opens and closes the drain port 3, and the second land 10b opens and closes the input port 1 and the feedback port 4. When the second land 10b is L
When moving in the direction, input port 1 is more closed and feedback port 4 is more open. Also, when the second land 10b moves in the R direction, the input port 1 is more opened and the feedback port 4 is more closed.

The third land 10c is connected to the second land 10c.
b together with the feedback oil chamber 5, and when the feedback port 4 is open, the feedback oil chamber 5
And when the feedback port 4 is closed, the feedback oil chamber 5 communicates with the drain.

The first and second lands 10a and 10b have the same diameter and the third land 10c has a smaller diameter than the first and second lands 10a and 10b.
The area difference according to the difference of A2 is the effective area for receiving the hydraulic pressure of the feedback port 4. Third land 10
c can move to a position where the feedback port 4 can be completely closed, and stops at the stopper 6 in the closed state.

A movable element 16 receiving an electromagnetic force when the coil 15 is energized is fixed to an end of the spool 10. When a forward current is supplied to the coil 15 from the energization control device 50, the spool 10 When the coil 10 moves in the L direction against the spring 12 and supplies a reverse current to the coil 15, the spool 10 moves in the R direction.

A movable stopper 20 is provided adjacent to the movable element 16. The movable stopper 20 is pushed in the L direction by the back spring 24, so that it normally hits the stopping portion 21 and is held at the normal holding position. The relationship between the spring 12 and the back spring 24 is such that even when the force of the spring 12 acts on the movable stopper 20 via the spool 10 and the movable element 16 to the maximum, the movable stopper 20 is held in the normal holding position. The spring 24 is set stronger.

Next, the operation will be described.

When power is not supplied, as shown in FIG. 1, the input port 1 and the feedback port 4 are open. In this state, when a current in the positive direction is applied to the coil 15 of the solenoid 14 by the energization control device 50, the spool 10 moves in the L direction against the force of the spring 12 by the electromagnetic force.

At the time of the normal control shown in FIG. 2, the R-direction force by the spring 12, the L-direction force acting on the spool 10 by the hydraulic pressure of the feedback port 4, and the L-direction force acting on the spool 10 by the electromagnetic force of the solenoid 14. Due to the balance with the directional force, the spool 10 moves, the communication ratio between the input port 1, the output port 2, and the drain port 3 is adjusted, and the control pressure (output) generated at the output port 2 is adjusted. That is, if the control pressure is too large than the set pressure, the spool 10 moves in the direction of decreasing the control pressure (L direction), and if the control pressure is too small, the spool 10 moves in the direction of increasing the control pressure (R direction). The control pressure is controlled so that the control pressure matches the set pressure. When the current is increased to increase the electromagnetic force, the control pressure is reduced from the balance of "force of spring 12" = "hydraulic pressure of feedback port 4 (force by control pressure)" + "electromagnetic force". If the electromagnetic force is weakened by making it smaller, the control pressure becomes larger from the same balance.

FIG. 3 shows a state at the time of fully closing when the current is maximized. At this time, since the input port 1 is closed and the output port 2 is connected to the drain port 3, the control pressure is minimized.

On the other hand, when the high voltage is maintained,
In the opposite direction (negative direction) to the coil 15 of the solenoid 14
Supply current. Then, as shown in FIG. 4, the spool 10 moves in the R direction while pressing the movable stopper 20, whereby the feedback port 4 is fully closed and the input port 1 is fully opened. Therefore, the control pressure is not fed back, and the supply pressure input to the input port 1 is output as it is as the control pressure, and the control pressure becomes maximum.

As described above, as the current decreases, the control pressure increases, and the control pressure can be maintained by shifting from zero to the negative direction. Therefore, as shown in FIG. 5, as shown in FIG. Low-pressure control area with respect to the area)
The same characteristics as the conventional low-pressure type can be provided. Therefore, the sensitivity between current and hydraulic pressure can be maintained at a constant level. Further, since the feedback port 4 can be shielded only by moving the spool 10 in the reverse direction, the switching valve can be omitted, and accordingly, the hydraulic circuit can be simplified, and the manufacturing cost and component cost can be reduced. Furthermore, basically, it is only necessary to supply a current in the reverse direction to the coil 15 when holding the high voltage, so that the structure is simple.

FIG. 6 shows an electromagnetic proportional control valve V2 according to the second embodiment.
Shows a state when the high pressure is maintained.

In the electromagnetic proportional control valve V2, the first solenoid 14 used during normal control (at the time of control in a low pressure range) is used.
A, other than the second solenoid 14 used for holding the high pressure.
B is provided. Each of the solenoids 14A, 14B is composed of a separate coil 15A, 15B and a common mover 16, respectively.

When the coil 15A of the first solenoid 14A is energized by the energization control device 51, an electromagnetic force acts on the mover 16 in the direction L in the figure, and the spool 10 moves in the direction L. Also, the second solenoid 1
When the coil 15B of 4B is energized, an electromagnetic force in the R direction acts on the mover 16, and the spool 10 moves in the R direction.
Therefore, normal control can be performed by using the first solenoid 14A, and high pressure can be maintained by using the second solenoid 14B. Other configurations and actions are first
Since the configuration is the same as that of the embodiment, the same reference numerals are given to the same portions in the drawings, and the repeated description will be omitted.

The electromagnetic proportional control valve V1 according to the above embodiment
In order to reverse the direction of the force applied when the reverse current is applied to the direction of the force applied when the forward current is applied, the mover 16 must be magnetized. In the electromagnetic proportional control valve V2 according to the embodiment, the mover 16
Need not be magnetized. Also, depending on the energization control device,
In such a case, the second embodiment is more convenient because a reverse current may not be able to flow.

[0034]

As described above, according to the present invention,
High pressure can be maintained without using a separate switching valve while maintaining the current-hydraulic sensitivity at a constant level. Therefore, the hydraulic circuit can be simplified, and manufacturing costs and component costs can be reduced.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing a state when a current is not supplied to an electromagnetic proportional control valve according to an embodiment of the present invention.

FIG. 2 is a sectional view showing a state of the valve during normal control (during pressure adjustment).

FIG. 3 is a cross-sectional view showing a state when the valve is fully energized (when fully closed).

FIG. 4 is a cross-sectional view showing a state when the valve is maintained at a high pressure (during reverse energization).

FIG. 5 is a characteristic diagram showing a relationship between current and control pressure in the valve.

FIG. 6 is a cross-sectional view showing a state when a high pressure is held according to another embodiment of the present invention.

FIG. 7 is a characteristic diagram of a conventional high-pressure valve.

FIG. 8 is a characteristic diagram of a conventional low-pressure valve.

FIG. 9 is a schematic diagram of this type of electromagnetic proportional control valve.

FIG. 10 is a circuit diagram showing a configuration in which a switching valve is added to a conventional electromagnetic proportional control valve.

FIG. 11 is a circuit diagram showing a configuration in which a switching valve is added to a conventional electromagnetic proportional control valve.

[Explanation of symbols]

 V1, V2: Electromagnetic proportional control valve 1: Input port 2: Output port 3: Drain port 4: Feedback port 10: Spool 12: Spring (biasing means) 14, 14A, 14B Solenoid 15, 15A, 15B: Coil 16 , 17 ... mover 20 ... movable stopper 21 ... stopping part 24 ... back spring 50, 51 ... energization control device

Claims (3)

[Claims] An input port to which a supply pressure from a hydraulic pressure source is input; an output port to output a control pressure to a control target; a drain port; a feedback port to which the control pressure is fed back; A spool for controlling the opening and closing and opening of the spool, an urging means for urging the spool to one side in the movement direction, and a solenoid for moving the spool against the urging force of the urging means, The position of the spool is controlled by the balance between the urging force of the urging means, the force acting on the spool by the hydraulic pressure of the feedback port, and the force acting on the spool by the electromagnetic force of the solenoid. An electromagnetic proportional control valve that adjusts a communication ratio of a port to generate a predetermined control pressure at the output port; Electromagnetic proportional control valves, characterized in that Kkupoto is provided with means for moving to a position fully closed. 2. The apparatus according to claim 1, wherein the means for moving the spool to a position where the feedback port is fully closed is a means for supplying a current to the solenoid in a direction opposite to that in a normal proportional control. Electromagnetic proportional control valve. 3. The electromagnetic proportional control valve according to claim 1, wherein the means for moving the spool to a position where the feedback port is fully closed is a second solenoid provided separately from the solenoid.