JP2019019898A - solenoid valve - Google Patents

Abstract

To provide a solenoid valve whose pulsation is suppressed.SOLUTION: A sleeve 20 includes an input port 22, an output port 23, a discharge port 24, a feedback port 25 connected with the output port on the outside of the sleeve, and a breathing port 26 connected to a spring chamber 21c along an axial direction. The feedback port is arranged adjacent to the breathing port in the axial direction. The spool 30 includes a first land part 31 having a first diameter L1 and located between the breathing port and the feedback port, a second land part 32 having a second diameter L2 smaller than the first diameter L1 and for opening/closing between the output port and the discharge port, and a third land part 33 having a third diameter L3 smaller than the first diameter and for opening/closing between the output port and the input port along the axial direction. An end surface on the solenoid side of the first land part and an end surface on the spring member side of the second land part or an end surface on the spring member side of the third land part are arranged oppositely in the axial direction.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a solenoid valve.

  Conventionally, an electromagnetic valve using a spool having three lands having different diameters is known (see Patent Document 1).

JP 2014-70727 A

  In a conventional solenoid valve, the fluid pressure at the output port can be adjusted by a feedback mechanism. However, when the fluid pressure at the input port suddenly fluctuates, the feedback mechanism causes vibration of the spool, and the fluid pressure at the output port may pulsate.

  An object of one embodiment of the present invention is to provide an electromagnetic valve in which pulsation is suppressed.

  According to one aspect of the present invention, a sleeve having a plurality of ports through which a fluid flows is arranged along a central axis, a spool that is accommodated in the sleeve and opens and closes the port as the shaft moves, A spring member that is housed in a spring chamber in the sleeve and pushes the spool toward one side in the axial direction; and a solenoid that pushes the spool against the elastic force of the spring member. An input port, an output port, an exhaust port, a feedback port connected to the output port outside the sleeve, and a breathing port connected to the spring chamber, the feedback port being connected to the breathing port Arranged adjacent to the axial direction, the spool having a first diameter along the axial direction between the breathing port and the feedback port; A first land portion positioned; a second land portion having a second diameter smaller than the first diameter; and opening and closing between the output port and the discharge port; and smaller than the first diameter A third land portion having a third diameter and opening and closing between the output port and the input port, and an end face on the solenoid side of the first land portion, and the second land portion An electromagnetic valve is provided in which an end surface on the spring member side or an end surface on the spring member side of the third land portion is disposed to face in the axial direction.

  According to the aspect of the present invention, an electromagnetic valve in which pulsation is suppressed is provided.

FIG. 1 is a cross-sectional view showing an electromagnetic valve according to an embodiment. FIG. 2 is a cross-sectional view showing an excited state in the electromagnetic valve of the embodiment.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a cross-sectional view showing the electromagnetic valve of the present embodiment. FIG. 2 is a cross-sectional view showing an excited state in the electromagnetic valve of the present embodiment.

  In the present embodiment, the central axis J extends in the left-right direction in FIGS. In the following description, the axial direction of the central axis J is simply referred to as “axial direction”, the radial direction around the central axis J is simply referred to as “radial direction”, and the circumferential direction around the central axis J is simply referred to as “axial direction”. This is called “circumferential direction”.

  The electromagnetic valve 1 of the present embodiment includes a spool valve 10 and a solenoid 70 that drives the spool valve 10. The solenoid valve 1 is a normally open solenoid valve that is in a state where the valve is opened when the power supply to the coil of the solenoid 70 is cut off.

  The spool valve 10 includes a sleeve 20, a spool 30, a fixing portion 50, and a spring member 80. The sleeve 20 is connected to a solenoid 70 at one end on the left side in the figure. The spool 30 and the spring member 80 are accommodated in the sleeve 20. The end of the spool hole 21 opposite to the solenoid 70 is closed by the fixing portion 50.

The sleeve 20 has a spool hole portion 21 that extends in the axial direction about the central axis J. The spool hole portion 21 opens on both axial sides of the sleeve 20. The cross-sectional shape orthogonal to the axial direction of the spool hole 21 is a circular shape.
The sleeve 20 has an input port 22, an output port 23, an exhaust port 24, a feedback port 25, and a breathing port 26. The input port 22, the output port 23, the discharge port 24, the feedback port 25, and the breathing port 26 are holes that penetrate from the radially outer side surface of the sleeve 20 to the radially inner side surface of the spool hole portion 21. And the inside of the spool hole 21 are connected. The position where each port opens in the circumferential direction of the sleeve 20 can be changed as appropriate.

  The input port 22, the output port 23, the discharge port 24, the feedback port 25, and the breathing port 26 are arranged in this order from the solenoid 70 side to the fixed portion 50 side in the axial direction. The output port 23 and the feedback port 25 are connected outside the sleeve 20. Part of the fluid flowing out from the output port 23 flows into the feedback port 25.

  The spool 30 has a cylindrical shape that extends in the axial direction about the central axis J. The spool 30 is disposed in the spool hole portion 21 along the central axis J so as to be movable in the axial direction. The end of the spool 30 on the solenoid 70 side is in contact with the pin 71 of the solenoid 70. The end of the spool 30 on the fixed portion 50 side is in contact with the spring member 80. The spool 30 includes, in order from the fixed portion 50 side, a first land portion 31, a first groove portion 30a, a second land portion 32, a second groove portion 30b, and a third land portion 33.

The first land portion 31 has a first diameter L1. The second land portion 32 has a second diameter L2 that is smaller than the first diameter L1. The third land portion 33 has a third diameter L3 that is smaller than the first diameter L1. In the case of the present embodiment, the second diameter L2 and the third diameter L3 are the same size. By making the outer diameter of the land portion in the spool 30 two types, the spool 30 and the sleeve 20 can be easily manufactured.
The first groove portion 30a has a diameter smaller than the first diameter and the second diameter. The second groove portion 30b has a diameter smaller than the second diameter and the third diameter.

  The outer diameters of the first land portion 31, the second land portion 32, and the third land portion 33 are substantially the same as the inner diameter of the spool hole portion 21 at the position where each is accommodated. The spool hole portion 21 includes a feedback chamber 21a, a pressure regulating chamber 21b, and a spring chamber 21c that are partitioned in the axial direction by the first land portion 31, the second land portion 32, and the third land portion 33. The feedback chamber 21 a is connected to the feedback port 25. The pressure regulation chamber 21 b is connected to the input port 22, the output port 23, and the discharge port 24. The spring chamber 21 c is connected to the breathing port 26.

  The first groove portion 30a is located between the first land portion 31 and the second land portion 32 and has a diameter smaller than the second diameter. The first groove portion 30a is located in the feedback chamber 21a.

  The 2nd groove part 30b is located between the 2nd land part 32 and the 3rd land part 33, and has a diameter smaller than a 2nd diameter and a 3rd diameter. The 2nd groove part 30b is located in the pressure regulation chamber 21b. The second groove portion 30 b is made to pass through the output port 23 and the discharge port 24 in the portion on the second land portion 32 side. The second groove portion 30 b is connected to the input port 22 and the output port 23 in the portion on the third land portion 33 side.

The fixing portion 50 is fixed to the end portion of the sleeve 20 opposite to the solenoid 70 and closes the opening portion of the spool hole portion 21.
The spring member 80 is a coil spring in this embodiment. The spring member 80 is accommodated in the spring chamber 21c. The spring member 80 is accommodated in a compressed state between the spool 30 in the spool hole portion 21 and the fixed portion 50, and pushes the spool 30 toward the solenoid 70 side.

  The solenoid 70 includes a pin 71 that is movable in the axial direction, a drive unit 72 that drives the pin 71, a housing 73 that fixes the drive unit 72 and the sleeve 20, and a connector 75 that is connected to the drive unit 72. Have.

  The pin 71 is a cylindrical pin made of a nonmagnetic material. The pin 71 is disposed along the central axis J, and a part thereof is inserted into the drive unit 72. The portion of the pin 71 that protrudes from the drive portion 72 is inserted into the spool hole portion 21 of the sleeve 20. In the spool hole 21, the pin 71 and the spool 30 are in contact in the axial direction.

  The drive unit 72 has a plunger, a coil, and a core (not shown). The plunger is a columnar member made of a ferromagnetic material, is disposed inside the cylindrical core, and is movable in the axial direction within the drive unit 72. The plunger is in contact with or connected to the end of the pin 71 opposite to the spool 30. The connector 75 is electrically connected to the coil of the drive unit 72.

  When the coil is energized by the electric power supplied via the connector 75 in the drive unit 72, the plunger moves to the spool 30 side along the axial direction by the magnetic force generated by the coil, and the pin 71 moves to the spool 30 side. Push. The pin 71 moves the spool 30 toward the fixed portion 50 against the spring force of the spring member 80.

As the spool 30 moves in the axial direction with respect to the sleeve 20, the connection state of the input port 22, the output port 23, and the discharge port 24 changes.
In the state shown in FIG. 1, the output port 23 and the discharge port 24 are closed by the third land portion 33, and the input port 22 and the output port 23 are connected by the second groove portion 30b. The fluid that flows in from the input port 22 flows out to the output port 23.
When the spool 30 moves to the right side with respect to the sleeve 20 from the state shown in FIG. 1, the third land portion 33 closes the space between the input port 22 and the output port 23, and the second groove portion 30b discharges the output port 23 from the output port 23. Port 24 is connected. The fluid in the output port 23 flows out to the discharge port 24 through the second groove portion 30b.

  In the state shown in FIG. 1, in the solenoid valve 1, the end surface 31 a on the solenoid 70 side of the first land portion 31 and the end surface 32 a on the spring member 80 side of the second land portion 32 are axially arranged in the feedback chamber 21 a. It is arrange | positioned facing. The first land portion 31 and the second land portion 32 have different outer diameters, and the areas of the end surface 31a and the end surface 32a are different. Therefore, a feedback force is generated in the spool 30 due to a difference in force with which the fluid flowing in from the feedback port 25 pushes the end surfaces 31a and 32a. In the electromagnetic valve 1, the pressure of the fluid flowing out to the output port 23 is determined by the balance of the feedback force, the spring force by the spring member 80, and the electromagnetic force of the solenoid 70.

  The feedback mechanism of the solenoid valve 1 moves the spool 30 according to the pressure fluctuation of the fluid flowing from the input port 22 and automatically adjusts the opening degree of the spool valve 10. For example, when the pressure of the fluid flowing in from the input port 22 increases, the pressure of the fluid flowing out of the output port 23 increases, and the pressure in the feedback chamber 21a increases. Then, the force pushing the end surface 31a having a relatively large area becomes larger than the force pushing the end surface 32a, and the spool 30 moves to the spring member 80 side. When the spool 30 moves to the spring member 80 side, the flow path connecting the input port 22 and the output port 23 becomes narrow, and the pressure of the fluid flowing through the output port 23 decreases. In this way, the pressure of the fluid flowing out from the output port 23 is kept constant.

  Here, when the pressure of the fluid flowing into the input port 22 suddenly fluctuates, the moving speed of the spool 30 by the feedback mechanism increases. Fluid pressure pulsates.

  In the present embodiment, the feedback chamber 21a is arranged next to the spring chamber 21c, and the first land portion 31 having a relatively large outer diameter is the first land portion 31 and the second land portion 32 that constitute the feedback mechanism. It arrange | positions at the spring chamber 21c side. With this configuration, pulsation of the fluid pressure at the output port 23 can be suppressed. This will be specifically described below.

  The inside of the feedback chamber 21 a is maintained at a high pressure by the fluid flowing from the feedback port 25. There is a gap between the outer peripheral surface of the spool 30 and the inner peripheral surface of the spool hole portion 21 to allow the axial movement of the spool 30, and fluid leaks to the adjacent chamber through this gap. In the feedback chamber 21a, the gap between the first land portion 31 having a relatively large outer diameter and the spool hole portion 21 is larger than the gap between the second land portion 32 and the spool hole portion 21, so that the first land A large amount of fluid leaks to the adjacent spring chamber 21c via the portion 31.

  Due to the above action, the fluid flows from the feedback chamber 21a into the spring chamber 21c, and the fluid accumulates in the spring chamber 21c. Thereby, the spring member 80 and the fluid in the spring chamber 21 c function as a damper that decelerates the spool 30. As a result, even when the pressure of the fluid flowing into the input port 22 fluctuates rapidly, the movement of the spool 30 by the feedback mechanism can be moderated, and the pulsation of the fluid pressure at the output port 23 can be suppressed.

  In the present embodiment, the diameter of the opening of the breathing port 26 connected to the spring chamber 21 c is smaller than the diameter of the opening of the discharge port 24. With this configuration, since the resistance when the fluid flows out from the breathing port 26 to the outside increases, the damping effect by the spring member 80 and the fluid is enhanced. As a result, the pulsation of the fluid pressure at the output port 23 can be further suppressed.

In the present embodiment, the configuration in which the input port 22, the output port 23, and the discharge port 24 are arranged in this order from the solenoid 70 side in the spool valve 10 has been described. However, the positions of the input port 22 and the discharge port 24 are It may be replaced. That is, in the spool valve 10, the discharge port 24, the output port 23, and the input port 22 may be arranged in this order from the solenoid 70 side. In this configuration, the positions of the second land portion 32 and the third land portion 33 of the spool 30 are also switched. In the feedback chamber 21a, the surface facing the end surface 31a on the solenoid 70 side of the first land portion 31 in the axial direction is This is the end face of the three land portion 33 on the spring member 80 side.
Even in the configuration described above, it is possible to obtain the operational effects of the electromagnetic valve 1 of the present embodiment described above.

  DESCRIPTION OF SYMBOLS 1 ... Solenoid valve, 20 ... Sleeve, 21c ... Spring chamber, 22 ... Input port, 23 ... Output port, 24 ... Discharge port, 25 ... Feedback port, 26 ... Breathing port, 30 ... Spool, 31 ... 1st land part, 31a, 32a ... end face, 32 ... second land portion, 33 ... third land portion, 70 ... solenoid, 80 ... spring member, J ... central axis, L1 ... first diameter, L2 ... second diameter, L3 ... 3rd diameter

Claims (5)

A sleeve having a plurality of ports through which fluid flows and disposed along a central axis;
A spool that is accommodated in the sleeve and that opens and closes the port with axial movement;
A spring member housed in a spring chamber in the sleeve and pushing the spool to one side in the axial direction;
A solenoid that presses the spool against the elastic force of the spring member;
With
The sleeve has an input port, an output port, a discharge port, a feedback port connected to the output port outside the sleeve, and a breathing port connected to the spring chamber along the axial direction.
The feedback port is disposed axially adjacent to the breathing port;
The spool has a first land having a first diameter along the axial direction and located between the breathing port and the feedback port, and a second diameter smaller than the first diameter. A second land portion that opens and closes between the output port and the discharge port; and a third land that has a third diameter smaller than the first diameter and opens and closes between the output port and the input port. A land portion,
The end surface on the solenoid side of the first land portion and the end surface on the spring member side of the second land portion or the end surface on the spring member side of the third land portion are arranged to face each other in the axial direction.
solenoid valve. In order from the solenoid side along the axial direction, the input port, the output port, the discharge port are arranged,
The third land portion and the second land portion are arranged in order from the solenoid side along the axial direction.
The solenoid valve according to claim 1. In order from the solenoid side along the axial direction, the discharge port, the output port, the input port are arranged,
In order from the solenoid side along the axial direction, the second land portion and the third land portion are arranged.
The solenoid valve according to claim 1.   The solenoid valve according to any one of claims 1 to 3, wherein the second diameter and the third diameter are equivalent in size.   5. The solenoid valve according to claim 1, wherein a diameter of the opening portion of the breathing port is smaller than a diameter of the opening portion of the discharge port.

Images