JP2569238Y2 - Solenoid valve with built-in relief mechanism - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a solenoid valve used in a hydraulic control system, and more particularly to a solenoid valve having a built-in relief mechanism for adjusting a hydraulic pressure sealed by the solenoid valve.

[0002]

2. Description of the Related Art Conventionally, various solenoid valves have been used in a fluid pressure control system to contain fluid pressure in the system. All of these solenoid valves have a relief structure for adjusting the contained fluid pressure. Therefore, in order to adjust the hydraulic pressure, it was necessary to provide a relief valve in the hydraulic control system separately from this solenoid valve. For this reason, it is difficult to reduce the size of the entire hydraulic control system, and it is also difficult to reduce the number of parts.

In order to solve such a problem, a solenoid valve having a built-in relief valve inside a solenoid valve body as shown in FIG. 3 has been proposed in the past (JP-B-51-26171). This solenoid valve will be briefly described with reference to FIG. 3. The solenoid valve includes flow paths 100 and 10 formed in a valve body.
1, a spring 103 for urging the valve 102 in the opening direction, a movable core 104 for moving the main valve 102 in the closing direction, and a hydraulic pressure sealed in the flow path 101. A relief spring 105 that opens the main valve 102 when the pressure becomes higher than a pressure, and a fixed iron core 107 that attracts the movable iron core when a current flows through the coil 106.
And a coil 106 for operating the movable iron core 104.

When a current flows through the coil 106, the movable core 104 is attracted to the right in the figure by the fixed core 107,
The main valve 102 moves to the right in the figure against the urging force of the spring 103 by the urging force of the relief spring 105, and cuts off the communication with the flow paths 100 and 101. Can be contained. In this state, if the hydraulic pressure sealed in the flow path 101 exceeds a predetermined hydraulic pressure determined by the relief spring 105 for some reason, the main valve 102 causes the relief spring 105
Moves to the left in the figure against the urging force of, discharges the liquid in the flow path 101 to the flow path 100 side, and reduces the liquid pressure in the flow path.
When the hydraulic pressure in the flow path 101 reaches a predetermined pressure, the main valve 102 moves to the right again in the drawing by the urging force of the relief spring 105, disconnects the communication between the flow paths 100 and 101, and seals the predetermined hydraulic pressure. In this way, the hydraulic pressure in the system enclosed by the solenoid valve is regulated by the relief valve.

As described above, since the solenoid valve incorporating the above-described relief valve can adjust the pressure of the liquid sealed in the flow path 101, the main valve and the valve seat of the main valve may be damaged, and the sealed high liquid Leakage of the hydraulic tube due to pressure can be effectively prevented.

[0006]

However, the above-mentioned solenoid valve has a problem that its manufacture is difficult because the main valve 102 has a complicated shape. In particular, main valve 1
Since it is necessary to cut off communication with the flow paths 100 and 101, the accuracy of the contact portion with the valve seat is very important. It is difficult to manufacture valves. Furthermore, in the above-mentioned solenoid valve, the main valve 102 is guided by the fixed iron core 107, and the biasing force of the spring 103 and the relief spring 105 acts on both ends thereof. The pressure acts and the main valve 1
For example, there is a problem that the sealing property between the valve seat 02 and the valve seat is deteriorated, and the solenoid valve with a built-in relief mechanism has not been put to practical use for the above various reasons.

The inventors of the present invention have focused on such problems and have conducted intensive studies. As a result, the shape of the valve was extremely simple.
We have succeeded in developing an extremely practical solenoid valve with a built-in relief mechanism that has good assembly accuracy and can reduce the number of assembly steps.
This solenoid valve with a built-in relief mechanism has a structure in which a valve rod is formed by a single round bar having a substantially uniform cross section, and has a structure that supports both ends of the valve rod. A set spring and a relief spring are arranged between these shaft supports. In addition, the casing for assembling the valve is divided into three parts so that the position of the valve rod can be adjusted while assembling the valve. This prevents the valve from tilting due to the spring biasing force. At the same time, an inexpensive and accurate solenoid valve with a built-in relief mechanism could be constructed.

[0008]

According to the present invention, there is provided an electromagnetic valve for sealing a hydraulic pressure in a hydraulic control system, wherein the electromagnetic valve includes a valve rod 3 having substantially the same cross section and a valve rod 3 having substantially the same cross section. Iron core 2 slidably mounted on
And a guide member 8 and a fixed iron core 9 that support both ends of the valve rod 3, and the valve rod 3 is disposed between the movable iron core 2 and the fixed iron core 9 via the movable iron core 2 to a return position. A biasing set spring 4 and a relief spring 5 disposed between the movable iron core 2 and the guide member 8 and allowing the valve rod to move to the release position when the contained hydraulic pressure exceeds a predetermined value. The valve rod 3 is configured to slide within the movable core by the urging force of the relief spring 5 to close the flow path when the movable core 2 is attracted by the fixed core 9. This is a means for solving the problem.

[0009]

[Operation] Normally, electricity does not flow through the coil 1,
The flow path 12 formed in the valve seat 6 communicates with the reservoir. However, when it is necessary to control the pressure by confining it in the hydraulic control system, a current is supplied to the coil 1 by a signal from an electronic control unit (not shown). The plunger 2 as a movable iron core is attracted to the fixed iron core 9 by the electromagnetic force generated at this time. At the same time, the valve rod 3 moves rightward in the figure by the spring force of the relief spring 5 acting via the stopper 3a, and closes the flow path 12 of the valve seat 6. In this manner, the solenoid valve with a built-in relief mechanism can contain the hydraulic pressure in the hydraulic control system.

On the other hand, when the hydraulic pressure in the system enclosed by the solenoid valve exceeds a predetermined hydraulic pressure determined by the relief spring 5, the hydraulic pressure causes the valve rod 3 to move leftward in the figure against the urging force of the relief spring 5. Then, the flow path 12 is opened and a part of the enclosed hydraulic pressure is discharged to the reservoir, and the hydraulic pressure in the hydraulic pressure control system decreases. When the fluid pressure during the fluid pressure control falls to a predetermined value, the valve rod 3 moves to the right again in the drawing by the urging force of the relief spring 5, closes the flow path 12, and confine the predetermined fluid pressure. In this way, the hydraulic pressure in the system enclosed by the solenoid valve is regulated by the relief valve.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment according to the present invention will be described below with reference to the drawings. FIG. 1 is a sectional view of a solenoid valve with a built-in relief mechanism as a first embodiment. In FIG. 1, reference numeral 10 denotes a solenoid valve with a built-in relief mechanism. The solenoid valve 10 includes a brake actuator, a switching valve,
It is shown in the figure as one component of a hydraulic control system including a hydraulic pressure source, a reservoir, and the like (this example shows a traction control device for an automobile).

The solenoid valve 10 with a built-in relief mechanism is a coil 1
A cylindrical member 7 made of a non-electromagnetic material is provided at the center of the coil 1. The cylindrical member 7 is 7
The solenoid valve 10 is divided into three parts by members a, 7b, and 7c. When the solenoid valve 10 is assembled, by adjusting these three divided cylindrical members, the assembly accuracy of the solenoid valve 10 can be maintained. I have. A sleeve 13 is provided on the inner surface of the cylindrical member 7, and a guide member 8 and a fixed iron core 9 that support both ends of the valve rod 3 are provided at a predetermined distance in the sleeve 13. The valve rod 3 is formed of a rod-like member having a substantially constant cross section.
Both ends are slidably supported by the guide member 8 and the fixed iron core 9.

A plunger 2 as a movable iron core is slidably fitted to the valve rod 3. Further, a stopper 3a for stopping the plunger 2 from moving leftward in the figure by the urging force of a set spring 4 described later is fixed to the valve rod 3 by caulking. A spacer 11 is disposed between the stopper 3a and the guide member 8, and regulates the urging force of the set spring 4 from moving the valve rod 3 leftward in the figure more than necessary. Inside the spacer 11, a relief spring 5 for determining the fluid pressure to be sealed in the fluid pressure control system is arranged, and urges the valve rod 3 rightward in the figure via the stopper 3a.

A set spring 4 is arranged between the plunger 2 and the fixed iron core 9. The set spring 4 is housed in a cylindrical hole formed in the fixed iron core 9. Arranging the set spring 4 in the fixed iron core in this way is a device for guiding the set spring 4 and making the entire solenoid valve compact. The spring force of the set spring 4 is set to be larger than the spring force of the relief spring 5. Therefore, as shown in the figure, the valve rod 3 is normally urged leftward by the urging force of the set spring 4 until the stopper 3a comes into contact with the spacer 11. Thus, the valve rod 3
Opens the flow path 12 formed in the valve seat 6, and the actuator is in communication with the reservoir.

Next, the operation of the above embodiment will be described. As described above, since no current normally flows through the coil 1, the valve rod 3 is in the position shown in FIG.
Is connected to the reservoir, so that the actuator is opened to the reservoir. However, when it is necessary to control the traction of the vehicle by sending a hydraulic pressure into the actuator, the switching valve is opened and a current is supplied to the coil 1 simultaneously with a signal from an electronic control unit (not shown). The plunger 2 is attracted to the fixed iron core 9 by the electromagnetic force generated at this time. At the same time, the valve rod 3 moves rightward in the figure by the spring force of the relief spring 5 acting via the stopper 3a, and closes the flow path 12 of the valve seat 6. As a result, hydraulic pressure is sent from the hydraulic pressure source into the actuator.
The hydraulic pressure is confined in the hydraulic control system by closing the switching valve.

Thereafter, by opening and closing the switching valve, the hydraulic pressure in the actuator is increased. At this time, when the pressure of the liquid sealed in the actuator exceeds a predetermined pressure determined by the relief spring 5, the valve pressure moves to the left in the figure against the urging force of the relief spring 5 due to the predetermined pressure. Thereby, the flow path 12 is opened and a part of the enclosed hydraulic pressure is discharged to the reservoir, and the hydraulic pressure in the actuator is reduced. When the hydraulic pressure in the actuator drops to a predetermined value, the valve rod 3 moves rightward again in the drawing by the urging force of the relief spring 5, and
The flow path 12 is closed to contain a predetermined hydraulic pressure. In this way, the hydraulic pressure in the actuator enclosed by the solenoid valve is regulated by the relief valve. Since the present embodiment is configured as described above, it is possible to prevent the valve from tilting due to the biasing force of the spring, and at the same time, to configure an inexpensive and accurate solenoid valve with a built-in relief mechanism.

Next, a second embodiment according to the present invention will be described with reference to FIG. The second embodiment differs from the first embodiment in that the arrangement of the relief spring in the first embodiment is devised, as is clear from the drawing, and there is no difference in other configurations. That is, in the first embodiment, the set spring, the plunger, the stopper, and the relief spring are individually and continuously arranged, which undesirably increases the length of the entire solenoid valve. Therefore,
In the second embodiment, the entire length is shortened by housing the relief spring inside the plunger.

In FIG. 3, a plunger 2 as a movable iron core is slidably fitted to the valve rod 3. The plunger 2 has an elongated hole 14 for accommodating the stopper 3 a and the relief spring 5. A spacer 11 also serving as a spring seat of the relief spring 5 is slidably fitted in the opening of the elongated hole 14, and the plunger 2 is movable in the axial direction with respect to the spacer 11. A relief spring 5 is arranged between the spacer 11 and the stopper 3a.

In the above configuration, since electricity does not normally flow through the coil 1, the valve rod 3 is at the position shown in the drawing, and the flow path 12 formed in the valve seat 6 is in communication with the reservoir. However, when it is necessary to send the hydraulic pressure into the actuator to perform traction control of the vehicle, a signal from an electronic control unit (not shown)
A current is supplied to the coil 1 at the same time when the switching valve is opened.
The plunger 2 is fixed to the fixed iron core 9 by the electromagnetic force generated at this time.
Is sucked. At the same time, the valve rod 3 moves rightward in the figure by the spring force of the relief spring 5 acting via the stopper 3a, and closes the flow path 12 of the valve seat 6. Thereby, hydraulic pressure is sent from the hydraulic pressure source into the actuator. By closing the switching valve, the hydraulic pressure is sealed in the actuator.

Thereafter, the hydraulic pressure in the actuator is increased by opening and closing the switching valve. At this time, when the hydraulic pressure sealed in the actuator becomes an unexpectedly high hydraulic pressure (a hydraulic pressure equal to or higher than the urging force of the relief spring), the valve pressure is applied to the valve rod 3 by the hydraulic pressure. It moves to the left in opposition, whereby the flow path 12 is opened and a part of the sealed hydraulic pressure is discharged to the reservoir. When the fluid pressure during the fluid pressure control decreases to a predetermined value, the valve rod 3 moves rightward in the drawing again by the urging force of the relief spring 5, closes the flow path 12, and confine the predetermined fluid pressure. As described above, in the second embodiment, since the relief spring is housed inside the plunger, its length can be reduced, and the entire solenoid valve can be further reduced in size. In the above-described embodiment, the guide member 8 and the spacer 11 are configured as separate bodies. However, it is a matter of course that the guide member 8 and the spacer 11 may be integrally configured. In addition, it goes without saying that the solenoid valve according to the present invention can be used for any hydraulic control system.

[0021]

According to the present invention, as described in detail above, according to the present invention, a valve rod is formed by one round rod in a solenoid valve, and both ends of the valve rod are pivotally supported. Since the spring and the relief spring are arranged, the shape of the valve rod is simplified and manufacturing is facilitated, the accuracy of the contact portion with the valve seat can be improved, and the valve rod is pivotally supported at both ends. Due to the structure, the biasing force of the set spring and relief spring does not act on the valve rod, improving the sealing performance with the valve seat.Since the structure is simple, the entire valve can be downsized. Thus, it is possible to provide an inexpensive and accurate solenoid valve with a built-in relief mechanism, and the like.

[Brief description of the drawings]

FIG. 1 is a sectional view of a solenoid valve with a built-in relief mechanism according to a first embodiment of the present invention;

FIG. 2 is a cross-sectional view of a solenoid valve with a built-in relief mechanism according to a second embodiment of the present invention.

FIG. 3 is a sectional view of a conventional solenoid valve having a built-in relief valve.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Coil 2 Plunger 3 Valve rod 4 Set spring 5 Relief spring 6 Valve seat 7 Cylindrical member

Claims (1)

(57) [Scope of request for utility model registration] 1. An electromagnetic valve for containing hydraulic pressure in a hydraulic control system, said electromagnetic valve comprising a valve rod 3 having substantially the same cross section, and a movable iron core slidably provided on said valve rod 3. 2, a guide member 8 and a fixed iron core 9 that support both ends of the valve rod 3, and the valve rod 3 that is disposed between the movable iron core 2 and the fixed iron core 9 and that moves the valve rod 3 through the movable iron core 2 to a return position. Set spring 4 that urges against
And a relief spring 5 disposed between the movable core 2 and the guide member 8 to allow the valve rod to move to a release position when the contained hydraulic pressure exceeds a predetermined value. The valve rod 3 is configured to slide within the movable iron core by the biasing force of the relief spring 5 to close the flow path when the fixed iron core 2 is attracted by the fixed iron core 9. valve.