JPH049505Y2 - - Google Patents

Description

[Detailed explanation of the invention] A. Purpose of the invention (1) Industrial application field This invention is an electromagnetic direction that displaces the spool by electromagnetic drive to control the flow of pressure oil from the inflow port to the outflow port intermittently. Regarding control valves.

(2) Prior art This type of electromagnetic directional control valve is
38722, Japanese Patent Laid-Open No. 60-26869, etc., the pressure oil flowing out from the outflow port is guided to an actuator, which operates a hydraulic cylinder or the like. However, in all of these, when switching ports, the return movement of the spool is slow due to the influence of the hydraulic pressure in the previous process.

This return operation of the spool does not pose a particular problem in normal oil pressure switching operations, but when switching an actuating part that operates at high speed, this switching operation does not occur smoothly and can cause damage to the part.

(3) Problems to be solved by the invention In view of the above-mentioned circumstances, the object of the invention is to provide an electromagnetic directional control valve suitable for high-speed hydraulic switching.

B. Structure of the invention (1) Means for solving problems According to the invention, a valve chamber 2 is formed in the valve body 1, which has a plurality of seal parts and which slides and guides an electromagnetically driven spool 3. An inflow port 5 and an outflow port 6 are communicated with the valve chamber 2 while being separated from each other via a valve hole 2A, and a bypass port 10 communicating with the discharge passage 9 is communicated with the valve chamber 2 on the side communicating with the outflow port 6. , the first seal part 3A of the spool 3 opens and closes the valve hole 2A, the second seal part 3B of the spool 3 opens and closes the bypass port 10, and in the closed position of the valve hole 2A of the spool 3, The second seal portion 3B opens the bypass port 10, and in the open position of the valve hole 2A of the spool 3, the second seal portion 3B opens the bypass port 10.
is closed, and in the closing operation of the spool 3, the second seal part 3B is opened before the valve hole 2A of the first seal part 3A is closed.

(2) Operation When the spool 3 is in the steady closed state position, the pressure oil is led to the inflow port 5, but the valve hole 2
Since A is closed, there is no flow of pressure oil.

When the spool 3 is opened, the valve hole 2A is opened, and the pressure oil flows from the inflow port 5 toward the operating section.

After that, when the spool 3 is closed, the bypass port 10 opens and the pressure oil on the outflow port 6 side is guided to the discharge passage 9 side, so the pressure on the outflow port 6 side rapidly decreases, and the pressure on the operating part is reduced. Stop the oil supply quickly. Along with this, the return operation of the spool 3 is also quickly performed.

(3) Embodiment An embodiment of the electromagnetic directional control valve of the present invention will be described based on the drawings.

(Configuration of Example) FIGS. 1 to 4 show one embodiment thereof.

This electromagnetic directional control valve V includes a spool valve V1 that connects and disconnects hydraulic pressure by moving a spool, and an electromagnetic valve section V2 that operates the spool of the spool valve V1 by electromagnetic drive.

In the spool valve V1, a substantially cylindrical valve chamber 2 is formed in the valve body 1.
A spool 3 is fitted into the valve chamber 2 so as to be movable in the axial direction. The spool 3 has two enlarged-diameter first and second seal portions 3A and 3B, and the outer circumferential surfaces of these seal portions 3A and 3B are in liquid-tight contact with the inner circumferential surface of the valve chamber 2.

The valve body 1 is formed with an inflow port 5 and an outflow port 6 that communicate with the valve chamber 2 and are substantially parallel to each other, with a valve hole 2A in the valve chamber 2. The inflow port 5 is led to a hydraulic pump, and the outflow port 6 is led to the working part. Inflow port 5 and outflow port 6
It also communicates with the valve hole 2A through an orifice 7 that bypasses the valve hole 2A.

The valve chamber 2 is divided into a front (right side in the figure) and a rear (left side in the figure) valve chambers through the valve hole 2A, and the front valve chamber receives the first seal portion 3A of the spool 3. , the rear valve chamber receives the second seal portion 3B of the spool 3. 1st of spool 3
The rear portion of the seal portion 3A connects and disconnects the inflow port 5 and the discharge port 6 by entering and exiting the valve hole 2A.

Two discharge passages 8 and 9 are formed in the valve body 1. The front discharge passage 8 communicates with the front part of the valve chamber 2 via a branch passage 8a. The rear discharge passage 9 communicates with the rear part of the valve chamber 2 via a bypass port 10 and a metering hole 11. Both of these discharge passages 8, 9 are led to a drain tank.

A spring accommodating recess 12 is formed in the first seal portion 3A, and the spring 1 is returned to the end face of the spring accommodating recess 12.
One end of the return spring 13 is housed in contact with the other end of the return spring 13, and the other end of the return spring 13 is brought into contact with the front end of the valve chamber 2, and the spring biasing force always biases the spool 3 in one direction, and the spool 3 is discharged from the inflow port 5. This prevents hydraulic pressure from flowing to port 6. Further, an appropriate number of discharge holes 14 communicating with the spring housing recess 12 are provided in the first seal portion 3A.

Rear end surface 15a of spool 3 and second seal portion 3
The rear end surface 15b of B serves as a pressure receiving surface 15 that receives hydraulic pressure from an oil flow passage described later.

A mouthpiece 17 having a flow passage 16 formed in the center is fitted into the rear end of the valve chamber 2, and the front end surface of the mouthpiece 17 collides with the rear end surface 15a of the spool 3, which is biased by the return spring 13. , plays the role of stoppa. Note that an oil groove 18 is recessed in the front end surface of the base 17.
Plan oil distribution.

The solenoid valve section V2 includes an electromagnetic actuating section A and a fluid control section B.

The electromagnetic actuating section A includes an electromagnetic solenoid 23 consisting of a cylindrical bobbin 21 having an inner hole 20 in the center, an electromagnetic coil 22 wound around the bobbin 21, and a fixed solenoid 23 inserted into the inner hole 20 of the bobbin 21. core 2
5, a movable core 27 disposed opposite to the fixed core 25 via a return spring 26, and a disk-shaped yoke 29 that abuts the front end of the bobbin 21 and is disposed around the movable core 27. It consists of a housing 30 arranged on the outside so as to hold each of these members. Each of these members, except for the bobbin 21, is made of a magnetic material. Furthermore, in the inner hole 20 of the bobbin 21, a sleeve 32 made of a non-magnetic material is attached to the fixed core 20.
The movable core 27 is attached to the front part of the movable core 27 with a strong fit, and its inner peripheral surface guides the axial movement of the movable core 27. A valve body 33 is integrally attached to the movable core 27. 35 is a terminal that supplies current to the electromagnetic coil 22. 37 is a ground terminal.

Among the above members, the fixed core 25, the movable core 27,
Fixed core 25 via yoke 29 and housing 30
A magnetic path is formed that returns to .

The fluid control section B has a mounting plate 40 as its main body, and a valve seat fitting 42 is interposed in an oil flow passage 41 formed in the mounting plate 40.

The mounting plate 40 has a large-diameter flange 44 at the front end in contact with the valve body 1 of the spool valve V1, and the mounting bolt 4
5. The small-diameter collar portion 46 at the rear end of the mounting plate 40 has a yoke 29 of the electromagnetic actuating portion A.
are brought into contact with each other, and the extending portion of the housing 30 is fixed by caulking. Thereby, the solenoid valve section V2 is integrally attached to the spool valve V1.

The oil flow passage 41 is divided into an upstream passage 41a and a downstream passage 41b via a valve seat fitting 42. The upstream passage 41a is connected to a hydraulic pressure source through an oil port (not shown). The downstream passage 41b is a spool valve V1
It communicates with the flow path 16 of the base 17 of the. The upstream passage 41a may be led independently from a hydraulic pump (not shown), or may be branched off from the inflow port 5 of the spool valve V1.

The valve body 33 comes into contact with and separates from the valve seat fitting 42 by moving back and forth, and the downstream passage 41b is moved from the upstream passage 41a to the downstream passage 41b.
The hydraulic pressure is turned on and off.

In addition, in this electromagnetic directional control valve V, 5
0 is an attachment attached to the main body 1 of the spool valve V1 with a screw, and includes a terminal 51 and a mounting arm 52. One end of the terminal 51 is electrically connected to the terminal 35 of the solenoid valve section V2, and the other end is electrically electrically connected to the ground terminal 37.

This embodiment is characterized in that a bypass port 10 is provided in the discharge passage 9 of the spool valve V1.

FIG. 2 shows the planar shape of the bypass port 10 portion. Based on the figures, aspects of the bypass port 10 will be described in more detail.

When the spool 3 is in the normal position (closed position), the bypass port 10 is removed from the second seal portion 3B and is in a fully open state. When the spool 3 is in the right position (open position), it is closed by the second seal portion 3B and is in a fully closed state.

In the figure, S is the stroke of the spool 3, and α is the distance from the end surface of the second seal portion 3B when it moves rightward by the stroke.
α is the distance β from the end face of the first seal portion 3A to the valve hole 2A when the first seal portion 3A is in the right position (see Fig. 4)
be made smaller than Therefore, the pipe port 10 begins to open before the spool 3 begins to return and the first seal portion 3A closes the valve hole 2A.

In this embodiment, the shape of the bypass port 10 is an ellipse that is long in the direction of the movement axis of the spool 3, but it is free to have a circular hole or other shapes (rectangle, square). .

In the electromagnetic directional control valve V of this embodiment configured as described above, in the hydraulic system, the inflow port 5 and the oil flow passage 41a are connected to the hydraulic pump, the outflow port 6 is led to the operating part, and the discharge port 5 is connected to the hydraulic pump. Passage 8, 9
is led to the oil tank via a discharge pipe.

(Operation of this embodiment) Next, the operation of the electromagnetic directional control valve V of this embodiment will be explained.

3 and 4 are schematic cross-sectional views illustrating the movement of the spool 3. FIG.

When a hydraulic pump (not shown) operates, pressure oil is guided to the inflow port 5 under normal conditions, but the valve hole 2A of the valve chamber 2 is closed by the first seal portion 3A of the spool 3. Therefore, a certain amount of pressure oil flows through the orifice 7 to the outlet port 6
In addition, another quantity flows out from the front discharge passage 8 through the discharge hole 14 of the spool 3 (see FIG. 3).

Furthermore, in the solenoid valve section V2, the pressure oil that is also pressure-fed from the hydraulic pump is guided to the upstream side 41a of the oil flow passage 41, but the valve body 33 closes the valve hole of the valve seat fitting 42. Therefore, there is no flow of pressure oil.

Now, when the movable core 27 is pulled toward the fixed core 25 against the biasing force of the return spring 26 using the magnetic force generated by energizing the electromagnetic solenoid 23 in the solenoid valve portion V2, the movable core 27 becomes integrated with the movable core 27. Valve body 33
is separated from the valve seat fitting 42, so the upstream side 41a and the downstream side 41b of the oil passage 41 are in communication.

As a result, the pressure oil is sent from the upstream oil flow passage 41a to the downstream oil flow passage 41b, and the spool valve V
It acts on the pressure-receiving surface 15 of the spool 3 through the flow path 16 of the nozzle 17.

As a result, the spool 3 rapidly moves to the right in the figure against the biasing force of the coil spring 13 (see FIG. 4). As a result, since the valve hole 2A opens, pressure oil from the inflow port 5 flows out in large quantities to the outflow port 6 through the valve hole 2A.
Pressure oil is led to the working part from the outflow port 6. Further, the pressure oil from the oil flow passage 41 flows out through the metering hole 11 to the discharge passage 9 at the rear. It should be noted that
At this time, the bypass port 10 is closed by the second seal portion 3B of the spool 3.

Next, when the power to the electromagnetic solenoid 23 is cut off,
The magnetic force disappears, and the valve body 33 returns to the spring 26.
The urging force returns to the original state and closes the valve seat fitting 42, thereby stopping the flow of pressure oil from the oil flow passage 41.

As a result, the pressing force of the spool 3 against the coil spring 13 in the right direction in the drawing is eliminated, and the spool 3 is moved to the left in the drawing by the biasing force of the coil spring 13.

As a result, the first seal portion 3A of the spool 3 closes the valve hole 2A, the flow of pressure oil from the inflow port 5 to the outflow port 6 is stopped, and the supply of pressure oil to the operating portion is stopped. It should be noted that at this time, the first seal portion 3A of the spool 3 is connected to the valve hole 2.
Prior to closing A, the bypass port 10 is opened.

Spool 3 of this electromagnetic directional control valve V like this
In the return operation, the first seal portion 3A of the spool 3 reduces the cross section of the flow path as it approaches the valve hole 2A, thereby rapidly restricting the flow rate.

In this operation, the first
By opening the bypass port 10 before the seal portion 3A closes the valve hole 2A, the hydraulic pressure remaining in the outflow port 6 is transferred to the bypass port 10.
The water is discharged from the air to the discharge passage 9.

Due to this action, the residual pressure in the outflow port 6 is rapidly and smoothly reduced, and therefore the spool 3 is quickly returned.

FIG. 5 shows the oil pressure-time curve. In the figure, the solid line shows the conventional structure (without a bypass port), and the dashed line shows the structure of this embodiment. The broken line in the solid line section indicates pressure fluctuation due to hunting. As shown in the figure, the pressure response of the directional control valve V of this embodiment is faster than that of the conventional one, and no hunting phenomenon occurs.

In this embodiment, the shape of the bypass port 10 is an ellipse, but with this shape, the ratio of the opening area to the stroke of the spool 3 is larger than that of a circular hole with the same area, and the dissipation effect of the residual pressure is increased accordingly. It will be done.

The electromagnetic directional control valve V of this embodiment having such characteristics is suitable for application to an operating part that requires high-speed switching.

An example of such an operating part is a valve device in an automobile engine.

FIG. 6 shows the rocker arm switching section.

In the figure, 100 is a first swinging arm, 101 is a second swinging arm, and 102 is an intermediate swinging arm.
A switching pin 106 consisting of a pin 104 and a second pin 105 is arranged. A hydraulic passage 110 for pushing out the switching pin 106 against the urging force of the return spring 108 is formed in the first swinging arm 100. 112 is a stopper.

In order to show the state of the switching pin 106 in the figure, the upper part of the pin 106 than the center axis shows the pin position at low speed, and the lower part shows the state at high speed.

The engine rotation speed Ne is detected by a detector,
This signal is sent to the control unit. The control unit discriminates between low-speed rotation and high-speed rotation, and sends an OFF signal to the solenoid valve section V2 of the main direction control valve V in the low-speed rotation range, and sends an ON signal to the solenoid valve section V2 in the high-speed rotation range. In response to the ON signal, pressure oil is sent out from the outflow port 6 through the inflow port 5 of the directional control valve V, guided to the hydraulic passage 110 of the main swing arm switching section, and moves the switching pin 106 to the high speed position. When the rotation speed becomes low and an off signal is generated, the flow of pressure oil rapidly stops and the switching pin 106 quickly returns to its low speed position, thereby eliminating the peeling phenomenon caused by the slow return movement of the switching pin 106. It can be prevented.

The present invention is not limited to the above-mentioned embodiments, and various design changes can be made within the scope of the basic technical idea of the present invention.

That is, the above embodiments are included within the technical scope of the present invention.

In the embodiment described above, the bypass port 10 is provided singly, but the bypass port 10 may be provided at two or more locations along the inner periphery of the valve chamber 2.

In this embodiment, the bypass port 10 communicates with the rear discharge passage 9, but it may also communicate with a discharge passage led to another oil tank, and if the discharge passages 8 and 9 are combined, communicated with this passage.

C. Effects of the invention According to the electromagnetic directional control valve of the invention, the residual pressure of the pressure oil from the outflow port during the closing operation of the spool decreases rapidly, and the responsiveness of the operating part improves accordingly. Further, the return operation of the spool becomes quick, and phenomena such as hunting can be prevented.

[Brief explanation of drawings]

The drawings show an embodiment of the electromagnetic directional control valve of the present invention, and FIG. 1 is a vertical sectional view showing the overall configuration of one embodiment, FIG. 2 is an enlarged sectional view of a portion thereof, and FIGS. 3 and 4. The figure is a schematic sectional view showing the operation of this electromagnetic directional control valve, and Figure 5 is the operating characteristic (pressure-time curve).
6 are sectional views showing the structure of a swing arm switching section of an automobile engine, which is an application example of the directional control valve of this embodiment. 1...Valve body, 2...Valve chamber, 2A...Valve hole, 3
...Spool, 3A, 3B...Seal part, 5...
Inflow port, 6...outflow port, 9...discharge passage, 10...bypass port.

Claims (1)

[Claims for Utility Model Registration] The valve body has a plurality of seals and a valve chamber that slides and guides an electromagnetically driven spool. A bypass port communicating with the discharge passage is communicated with the valve chamber on the side communicating with the outflow port, a first seal portion of the spool opens and closes the valve hole, and a second seal portion of the spool opens and closes the valve hole. The bypass port is opened and closed, and when the valve hole of the spool is in the closed position, the second seal part opens the bypass port, and when the valve hole of the spool is in the open position, the second seal part is the bypass port. , and in the closing operation of the spool, the second seal portion opens before the valve hole of the first seal portion is closed.