JPH0629571Y2 - Balanced 3-port solenoid valve - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to a balanced type three-port solenoid valve used in an industrial machine utilizing fluid pressure or vacuum pressure.

[Prior Art] In a known 3-port solenoid valve, the fluid pressure of the pressure fluid flowing from the input port side is applied to the surface of the movable iron core facing the fixed iron core, while the output port side is open to the outside. Therefore, the input valve member closes the valve seat in addition to the urging force of the return spring and the acting force of the pressure difference between the input side pressure and the discharge side pressure applied to the opening area of the valve seat. .

Therefore, since the attraction force of the movable iron core generated by the exciting coil needs to be large in order to overcome the above-mentioned force, the electromagnetic portion of the solenoid valve having a large diameter of the valve seat is downsized and the labor is saved. Is difficult.

In order to solve this problem, a movable iron core is provided with an axial through hole and a seal sliding portion approximately equal to the inner diameter of the input valve seat, and the seal sliding portion is provided in the fixed portion. It is possible to balance the fluid pressure acting on the movable iron core by sealing.

However, in the solenoid valve, there is a problem that noise and wear are likely to occur due to collision when the movable iron core is attracted to the fixed iron core, and in order to prevent this, a cushioning member is provided between the fixed iron core and the movable iron core. Then, when the fixed iron core attracts the movable iron core, the buffer member closes the through hole of the movable iron core, which causes a new problem that the pressure balance of the movable iron core is lost.

[Problem to be Solved by the Invention] The problem to be solved by the present invention is to provide a balanced type three-port solenoid valve in which the valve member can open and close the valve seat with a small force and can prevent collision between the iron cores. is there.

[Means for Solving the Problems] In order to solve the above problems, a balanced 3-port solenoid valve according to the present invention includes an input port, an output port, and a discharge port.
An input valve seat and an exhaust valve seat formed between these ports, a movable iron core having an input valve member and an exhaust valve member for opening and closing these valve seats, and a fixed iron core arranged to face the movable iron core. In a 3-port solenoid valve having a movable iron core return spring, the input valve seat and the discharge valve seat have substantially the same diameter,
The input valve member and the valve mounting body having the discharge valve member are attached to the movable iron core, a seal sliding portion having substantially the same diameter as both valve seats is provided, and these are penetrated through the movable iron core and the valve mounting body. A through hole in the axial direction is provided, a seal member that seals between the seal sliding portion and the seal sliding portion is provided in the fixed portion facing the seal sliding portion, and the discharge valve member is attached by suction of the movable iron core by the fixed iron core. The discharge valve seat is closed, and the opening / closing stroke of the discharge valve member is set to be slightly smaller than the distance between the two iron cores.

[Operation] When the input valve member closes the input valve seat and the discharge valve member opens the discharge valve seat, the pressure receiving area of the input valve member is input by the input valve seat and the seal member having substantially the same diameter. Since the valve seat side and the seal member side are substantially equal and the fluid pressure on the discharge side acts on both ends of the movable core by the through holes, the fluid pressure received by the movable core is balanced. Therefore, a large electromagnetic attraction force is not required to attract the movable iron core.

When the movable iron core is attracted to the fixed iron core, the opening / closing relationship between the two valve seats is reversed and the flow direction of the fluid is switched. At this time,
The opening / closing stroke of the discharge valve member that comes into contact with the discharge valve seat when the movable iron core is sucked is set to be slightly smaller than the distance between the iron cores of the fixed iron core and the movable iron core. Both iron cores will be attracted to each other while maintaining a small gap, and collision due to the adsorption will be prevented.

In this case, since the discharge valve member also serves as a damper for cushioning the collision, it is possible to prevent noise and wear due to collision between the iron cores. Further, since the diameters of both valve seats and the seal diameter of the seal member are substantially equal and both ends of the movable core communicate with each other through the through holes, the movable core operates even when the opening / closing relationship of the valve seat is reversed. Fluid pressure is balanced. Therefore, the movable iron core is returned to its original state by the small biasing force of the return spring.

[Embodiment] An embodiment of the present invention will be described below in detail with reference to the drawings.

The balanced 3-port solenoid valve shown in FIG. 1 comprises a valve portion 10 and an electromagnetic operating portion 11, and a valve body 13 of the valve portion 10 is provided with an input port 14, an output port 15 and a discharge port 16. , Input port 14 and output port 15
And an exhaust valve seat 18 are formed between the output port 15 and the exhaust port 16, respectively.

On the other hand, in the electromagnetic operating unit 11, a magnetic frame 22 having a U-shaped cross section is fitted to the bobbin 20 made of a non-magnetic material around which the exciting coil 21 is wound, and the bobbin 20 and the magnetic frame 22 are formed. A fixed iron core 23 is inserted and fixed to one side of the hole. The fixed core 23 has a guide tube 2 made of a non-magnetic material.
One end of the guide tube 24 is fixed, and the other end of the guide tube 24 projects from the magnetic frame 22 and reaches the center hole of the set nut 25. A movable iron core 26 penetrating the valve seats 17 and 18 is slidably inserted through a bearing 27 made of oil-containing resin or the like.

The movable iron core 26 includes a seal sliding portion 26a that is sealed by a seal member described later, and is biased in a direction away from the fixed iron core 23 by a return spring 31 that is compressed between the movable iron core 26 and the fixed iron core 23. The input valve member 32 that opens and closes the input valve seat 17 and the discharge valve member 3 that opens and closes the discharge valve seat 18 are provided at a portion of the tip of the movable iron core 26 located inside the valve portion 10.
3 are attached integrally to each other, and the movable iron core 26 and the valve mount 34 are provided with a through hole 30 in the axial direction.
Are formed.

The valve member that comes into contact with the valve seat when the movable iron core 26 is sucked by the fixed iron core 23, that is, the discharge valve member 33 also has a function as a damper that alleviates a collision at the time of adsorption, and a valve associated with the suction. A thin hard plate is made of a high hardness elastic material such as urethane rubber having a hardness that is not easily deformed by abutting against a seat, and the entire rear surface is supported by the valve mounting body 34. On the other hand, the input valve member 32
Is made of a low hardness elastic material such as rubber which is lower in hardness than the discharge valve member 33 and is soft enough to obtain sufficient sealing performance by the biasing force of the return spring 31. The opening / closing stroke of the discharge valve member 33 is set to be slightly smaller than the distance between the fixed iron core 23 and the movable iron core 26. Therefore, when the movable iron core 26 is attracted to the fixed iron core 23, the discharge valve member 33
Contacting the discharge valve seat 18 causes the two iron cores 23, 26 to
A small gap is kept between them and collisions due to adsorption are prevented.

Further, in the set nut 25 integrated with the electromagnetic operating unit 11, between the annular member 36 abutting the tip thereof,
A seal member 37 such as a cap seal that seals the seal sliding portion 26a of the movable iron core 26 is fitted, and by screwing the set nut 25 to the valve body 13, the electromagnetic operating portion 11 is attached to the valve portion 10. Installed. The seal diameter of the seal member 37, in other words, the seal sliding portion 2
The diameter of 6a is set to be substantially equal to the diameters of the valve seats 17 and 18, and the electromagnetic operating portion 11 is molded with a synthetic resin in order to prevent deterioration of the electrical insulation of the exciting coil 21.

Incidentally, reference numeral 38 in the figure denotes a dustproof member attached to the discharge port 16.

In the solenoid valve of the above embodiment, when the exciting coil 21 is not excited as shown in the figure, the movable iron core 26 is separated from the fixed iron core 23 by the urging force of the return spring 31, and the input valve member 32 is the input valve seat. 17 is closed and the discharge valve member 33 opens the discharge valve seat 18.

In this state, since the seal diameter of the seal member 37 and the diameters of the valve seats 17 and 18 are substantially equal, the input valve member 32
Since the pressure receiving areas of the input valve seat 17 side and the seal member 37 side are substantially the same and the through hole 30 is provided in the movable iron core 26 and the valve mounting body 34, the input side and the discharge side acting on the movable iron core 26 are The fluid pressure is approximately balanced. Therefore, when switching the solenoid valve, the fixed iron core 23 and the movable iron core 26
The suction force required between and is small enough to overcome the biasing force of the return spring 31 described above.

When the exciting coil 21 is excited, the movable iron core 26 is attracted to the fixed iron core 23, the input valve member 32 opens the input valve seat 17, and the discharge valve member 33 closes the discharge valve seat 18 to cause the flow of fluid. The direction changes. Here, when the movable iron core 26 is sucked, since the opening / closing stroke of the discharge valve member 33 is set to be slightly smaller than the distance between the iron cores of the fixed iron core 23 and the movable iron core 26, the discharge valve member 33 is set to the discharge valve member 33. By abutting on the seat 18, the two iron cores attract each other while maintaining a small gap, thereby preventing a collision caused by the mutual attraction of the iron cores. Also, both valve seats 17, 1
Since the diameter of No. 8 and the seal diameter of the seal member 37 are substantially equal and the through hole 30 is open, the fluid pressure acting on the movable iron core 26 is balanced. Therefore, when the excitation of the exciting coil 21 is released, the movable iron core 26 moves to the return spring 3
With a small biasing force of 1, the input valve member 32 closes the input valve seat 17 and the discharge valve member 33 returns to the illustrated state in which the discharge valve seat 18 is opened.

[Effect of the Invention] According to the balanced 3-port solenoid valve of the present invention, the fluid pressure acting on the movable iron core is always balanced regardless of the opening / closing of each valve seat by the valve member. Since the valve member can open and close the valve seat by the small biasing force of the spring, the 3-port solenoid valve can be made compact and labor-saving.

Further, since the fixed core and the movable core are prevented from colliding with each other by the contact between the discharge valve member and the discharge valve seat, deformation and wear due to mutual collision of the iron cores are prevented without losing the pressure balance function of the movable core. be able to.

[Brief description of drawings]

FIG. 1 is a vertical sectional view showing an embodiment of the present invention. 14 ... input port, 15 ... output port, 16 ... discharging port, 17 ... input valve seat, 18 ... discharging valve seat, 23 ... fixed iron core, 26 ... movable iron core, 31 ... return spring, 32 ... Input valve member, 33 ... Discharge valve member, 34 ... Valve mounting body, 37 ... Sealing member.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Creator Hisao Sagara 938 Inari-cho, Soka-shi, Saitama Inside the grass processing plant of Sintered Metal Industry Co., Ltd. (56) References 57-190972 (JP, U)

Claims (1)

[Scope of utility model registration request] 1. A movable iron core having an input port, an output port and an exhaust port, an input valve seat and an exhaust valve seat formed between these ports, and an input valve member and an exhaust valve member for opening and closing these valve seats. In a three-port solenoid valve having a fixed iron core arranged to face the movable iron core and a return spring for the movable iron core, the input valve seat and the discharge valve seat have substantially the same diameter, and the movable iron core has The input valve member and the valve mounting body having the discharge valve member are attached, and a seal sliding portion having substantially the same diameter as both valve seats is provided, and the movable iron core and the valve mounting body are axially penetrated. A hole is provided, a seal member for sealing between the seal sliding portion and the seal sliding portion is provided at the fixed portion facing the seal sliding portion, and the discharge valve member is closed by suction of the movable iron core by the fixed iron core. And opening and closing of the discharge valve member Balanced 3-port solenoid valve with stroke set slightly smaller than the distance between the two iron cores.