JP2503928Y2 - Constant differential pressure valve - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to a constant differential pressure valve for maintaining a differential pressure between a high-pressure side passage and a low-pressure side passage at a predetermined pressure.

A constant differential pressure valve generally presses the valve element from the low-pressure side flow passage side to the valve seat formed at the communication port between the high-pressure side flow passage and the low-pressure side flow passage by the biasing means, and the differential pressure between both flow passages is reduced. When the pressure is equal to or lower than a predetermined pressure, the pressure is closed, and when the pressure difference between the two flow paths exceeds the predetermined pressure, the pressure is opened to keep the pressure difference between the two flow paths constant.

[Conventional technology]

FIG. 2 shows a flat valve body 51 and a valve seat 52 used in a conventional constant differential pressure valve. In the case where the valve portions are in planar contact as described above, the differential pressure between the pressure in the high pressure side flow passage 53 and the pressure in the low pressure side flow passage 50 acts on the inner diameter d of the contact portion between the valve body 51 and the valve seat 52. It is unclear whether it acts on the outer diameter D or on its average size.

Therefore, it is unclear how to consider the effective pressure receiving area of the valve, and it is unclear how to set the urging force to obtain a predetermined constant differential pressure, so accurate pressure setting is performed. Was difficult.

Therefore, for example, a conical valve body as shown in FIG.
54 is also conceivable, but this is not preferable because it has the drawback that it will not close completely if it is tilted even a little.

Therefore, it is considered that the valve body 55 is formed in a spherical shape as shown in FIG. 4 as a valve whose opening and closing is not affected by the inclination and the effective pressure receiving area becomes clear. However, in this case, if the valve body 55 shifts slightly laterally with respect to the valve seat 52, the valve will not close completely. You are free to roll around.

[Problems to be solved by the device]

As described above, it is preferable to use a spherical valve element in the constant differential pressure valve, but as shown in FIG. 5, if a small dust 59 is attached between the surface of the plunger 56 and the valve element 55, There is a drawback that the valve body 55 does not roll and the valve does not close. Generally, opening and closing of the valve is performed by a very delicate operation of about 0.03 mm or less, and even if a very small dust 59 of 0.01 mm or less adheres, the valve does not close completely and the high pressure side flow path 53 The pressure of
A predetermined pressure difference from the pressure in the low-pressure side channel 50 cannot be obtained.

An object of the present invention is to provide a constant differential pressure valve that solves the above-mentioned conventional drawbacks, makes the best use of the advantages of the spherical valve, and does not cause defective opening / closing even if there is dust or the like.

[Means for solving the problem]

In order to achieve the above-mentioned object, the constant differential pressure valve of the present invention is configured such that a valve body is pressed from a low pressure side flow passage side by a biasing means to a valve seat formed at a communication port between a high pressure side flow passage and a low pressure side flow passage. , A constant differential pressure valve that closes when the differential pressure between both flow paths is below a predetermined pressure and opens when the differential pressure between both flow paths exceeds a predetermined pressure to make the differential pressure between both flow paths constant. It is characterized in that the body is formed into an elongated rod shape, one end side of which is formed into a spherical shape that is in close contact with the valve seat, and the above-mentioned valve body is swingably arranged with the other end side as a fulcrum.

[Action]

When the internal pressure difference between the high-pressure side passage and the low-pressure side passage is less than or equal to a predetermined pressure, the urging force of the urging means overcomes the pressure difference, so that the spherical portion of the valve element is pressed against the valve seat and the valve is opened. close.

When the differential pressure exceeds a predetermined pressure, the differential pressure overcomes the biasing force of the biasing means, the valve body separates from the valve seat, and the valve opens. At this time,
The valve body slightly swings around the fulcrum on the other end side.

When the differential pressure becomes equal to or lower than the predetermined pressure again, the biasing force of the biasing means overcomes the differential pressure and the valve is closed. In this operation, even if a small dust or the like is attached near the fulcrum of the valve element, the distance between the spherical part that becomes the force point of the swinging motion and the other end that becomes the fulcrum is long, so the lever action Thus, the force for guiding the valve body to the valve seat easily pushes away dust and the like, and the valve body freely swings, and the spherical portion of the valve body comes into close contact with the valve seat to close the valve.

[Example] An example will be described with reference to the drawings.

In FIG. 1, 1 is a housing, 2 is a high-pressure side passage,
Reference numeral 3 is a low pressure side flow path. A valve seat 4 is formed at a communication opening portion of both the flow paths 2 and 3.

Reference numeral 5 denotes a plunger slidably fitted in the upper half of the sleeve 6 with its axis aligned with the valve seat 4. The plunger 5 is made of iron, magnetic stainless steel, or the like, and is biased toward the valve seat 4 by the compression coil spring 7. Further, a thin and deep blind hole 10 is bored from above along the axis of the plunger 5.

Reference numeral 8 is an adjusting screw for adjusting the strength of the spring force of the compression coil spring 7, which is screwed onto an iron core 9 fixedly inserted in the lower half of the sleeve 6.

An electromagnetic coil 11 is provided so as to surround the outside of the sleeve 6, and a yoke 12 is fixedly provided so as to surround the sleeve 6 and connect the iron core 9 and the iron plate 13. Therefore, when the electromagnetic coil 11 is energized, an electromagnetic force acts between the plunger 5 and the iron core 9, and by changing the energization amount to the electromagnetic coil 11, the biasing force acting on the plunger 5 is finely adjusted. be able to. 21 to 24 are O-rings for sealing.

Reference numeral 15 denotes a valve body, which is formed by fixing a steel ball 15b to the head of an elongated rod-shaped rod 15a by spot welding or the like. The steel ball 15b is in close contact with the valve seat 4 and can completely close the valve seat 4. The rod 15a is inserted into the hole 10 formed in the plunger 5, and the lower end portion 15c of the rod 15a has a hole 10a.
Abuts the bottom.

The bottom of the hole 10 is formed in a conical recess, while the lower end 15c of the rod is rounded into a spherical shape. Therefore, the lower end portion 15c of the rod does not shift from the axial position of the hole 10, and the valve body 15 can freely swing about the lower end portion 15c as a fulcrum.

 Next, the operation of the above embodiment will be described.

When the pressure difference between the high-pressure side flow path 2 and the low-pressure side flow path 3 is less than or equal to a predetermined pressure, the biasing force F determined by the electromagnetic force generated by the electromagnetic coil 11 and the spring force of the compression coil spring 7 exceeds the pressure difference. Therefore, the steel ball 15b portion of the valve body 15 is located in the valve seat
The high pressure side flow path 2 and the low pressure side flow path 3 are closed by being pressed against the valve to close the valve.

Since the valve seat 4 and the steel ball 15b at this time are almost in line contact with each other, the effective pressure receiving area of the valve body 15 can be specified very accurately.

When the differential pressure exceeds a predetermined pressure, the differential pressure overcomes the urging force F, the valve body 15 is slightly pushed down, the valve is opened, and the fluid in the high pressure side flow path 2 flows into the low pressure side flow. It flows into the road 3. At this time, the valve element 15 slightly swings in either direction with the lower end portion 15c as a fulcrum so that the steel ball 15b partially contacts the valve seat 4.

When the differential pressure becomes equal to or lower than the predetermined pressure again, the urging force F overcomes the differential pressure, the plunger 10 pushes up the valve element 15, and the valve element 15 causes the valve seat 4 to move.
And the valve is closed. In this way, the differential pressure between the high pressure side flow path 2 and the low pressure side flow path 3 is always maintained at a predetermined pressure. At the time of operation at this time, the valve body 15 is moved to the lower end portion 15 by the force of guiding the steel ball 15b portion to the center of the valve seat 4.
Swing with c as the fulcrum. Therefore, even if a small dust or the like is attached near the fulcrum of the lower end portion 15c, the lever action can easily displace the dust or the like near the lower end portion 15c by the force applied to the head portion of the valve body 15. Therefore, the valve body 15 freely swings, and it is possible to close the valve securely by making close contact with the valve seat 4.

The above-mentioned predetermined pressure is applied to the adjusting screw 8 and the electromagnetic coil 11.
Can be set arbitrarily. Further, the head portion of the valve body 15 does not necessarily have to be a steel ball, and the surface contacting the valve seat 4 may be a spherical surface, and the valve body 15 may be formed as one part as a whole.

[Effect of device]

According to the constant differential pressure valve of the present invention, since the contact surface of the valve body with respect to the valve seat is formed into a spherical shape, it is possible to accurately grasp the effective pressure receiving area and perform accurate pressure control. Moreover, since the valve element is formed into a slender rod shape and is swingable with the other end side as a fulcrum, even if there is a small dust near the fulcrum, the valve element easily rocks and makes close contact with the valve seat. To do. as a result,
Since the valve can be reliably closed, there is an excellent effect that the pressure control of the constant differential pressure can be stably and accurately performed.

[Brief description of drawings]

FIG. 1 is a longitudinal sectional view of an embodiment, and FIGS. 2 to 5 are explanatory views of a conventional example. 2 ... High pressure side flow path, 3 ... Low pressure side flow path, 4 ... Valve seat, 5
…… Plunger, 7 …… Compression coil spring, 8 …… Adjustment screw, 9 …… Iron core, 10 …… hole, 11 …… Electromagnetic coil, 15 ……
Valve body, 15a …… rod, 15b …… steel ball, 15c …… bottom end (fulcrum).

Claims (1)

(57) [Scope of utility model registration request] 1. A valve body is pressed from a low pressure side flow path side by a biasing means against a valve seat formed at a communication port between the high pressure side flow path and the low pressure side flow path so that the differential pressure between both flow paths is a predetermined pressure. Close when:
In a constant differential pressure valve that opens when the pressure difference between both flow paths exceeds a predetermined pressure so as to make the pressure difference between both flow paths constant, the valve body is formed into an elongated rod shape, and one end of the valve body is connected to the valve seat. A constant differential pressure valve characterized in that the valve body is formed in a spherical shape that is in close contact with, and the valve body is swingably arranged with the other end side as a fulcrum.