JP2517209Y2 - Fluid switching valve - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial application] The present invention relates to a fluid switching valve, and more particularly to a fluid switching valve in which a lubricant is prevented from being mixed into a fluid flowing through a flow path. is there.

[Prior Art] A valve body and a drive portion of a fluid switching valve are normally sealed by an O-ring provided on an outer peripheral surface of a valve rod.

However, a sliding seal using an O-ring needs to be coated with a lubricant such as grease, which mixes with the fluid flowing through the flow path and causes a trouble.

For this reason, in the case of a fluid in which mixing of the lubricant is disliked, the O-ring is used without being coated with the lubricant, but the ring has a short life and needs to be replaced frequently, which makes maintenance troublesome.

In addition, it is possible to seal the valve body and the drive part with a diaphragm, but since the diaphragm seal has a large pressure receiving area, it is not only easy to break if the fluid pressure is high, but the force acting on the valve stem is also increased. Needs to be balanced.

[Problems to be Solved by the Invention] An object to be solved by the present invention is to provide a fluid switching valve which has no lubricant mixed therein and has a long life.

[Means for Solving the Problems] In order to solve the above problems, the present invention provides a valve body having a valve body having a plurality of ports and a flow passage communicating these ports, and a valve rod having a seal portion for opening and closing the flow passage. In a fluid switching valve including a drive unit for driving the valve rod and a diaphragm that seals between the valve body and the drive unit, an outer portion of the diaphragm is provided for reducing a pressure receiving area thereof. The outer support moves from the drive side, and the inner part moves integrally with the valve rod to regulate the displacement of the diaphragm. In either case, the swelling state is maintained on the drive portion side of the diaphragm so that the stress is not concentrated and acts on the diaphragm.

[Operation and Effect of Invention] When the valve rod is driven by the drive portion, the seal portion provided on the valve rod opens and closes the flow path.

In this case, by sealing the gap between the valve body and the drive unit with the diaphragm, the lubricant in the drive unit does not mix with the fluid flowing through the flow path, so that troubles due to the mixing of the lubricant can be completely prevented.

Further, since the pressure receiving area of the outer side portion of the diaphragm is reduced by the outer side support that supports the diaphragm from the drive portion side, and the inner side portion is supported from the valve body side by the inner side support that restricts the displacement of the diaphragm, During both opening and closing of the flow path and after opening and closing the flow path, the diaphragm keeps its bulging state on the drive unit side and stress concentrates and does not act, resulting in damage even if the fluid pressure increases. There is no fear and there is no need to balance the forces acting on the valve stem.

Therefore, the life of the fluid switching valve can be dramatically extended.

[Embodiment] FIG. 1 shows a first embodiment of the present invention which is suitable for a paint supply valve for supplying paint to a coating machine (not shown), and a fluid switching valve configured as a 3-port valve is a valve body. 1 and drive unit 2
And a valve seat base 3 attached to the opposite side of the drive unit 2 of the valve body 1 is made of a wear-resisting and chemical-resisting resin such as fluorine resin, Has been inserted into.

The valve body 1 has a fluid inlet 10 and a circulation port at opposite positions.
A valve rod 12 is inserted into a flow path that includes the inlet 11, the circulation port 11 and the outlet 13 of the valve seat base 3.

The valve rod 12 has a seal portion 14 at one end for opening and closing the outlet 13 by contacting and separating from the valve seat 3a of the valve seat base 3, a bulging portion 12a in the middle, and an opening 16 of the valve body 1 at the other end. It extends through the inside of the hood 17 of the drive unit 2. Further, on the side of the drive portion 2 of the bulging portion 12a, an inner support which also serves as a seal portion of the valve seat 15 is provided.
19, the cylinder shaft 20 and the piston 21 are sequentially fitted, and these are attached to the valve shaft 12 with a nut screwed to the other end of the valve rod so as to be integrally movable. The inserted outer support 22 is pressed toward the valve body 1 by a spring 23 contracted between the outer support 22 and the piston 21.

The inside of the opening 16 has an inner support 19 and a cylindrical shaft 20.
The outer edge of the diaphragm 25 is sealed by an annular diaphragm 25 sandwiched between the valve body 1 and the outer support 22. The outer portion of the diaphragm 25 is supported by the support portion 22a of the outer support 22 on the drive portion 2 side, and the inner portion is closed by the valve portion. They are respectively supported by the support portions 19a of the inner support 19 on the body 1 side.

Further, the valve rod 12 has a metal seal material 2 provided on the bulging portion 12a.
6 and O-ring 27 provided on piston 21
Are double-sealed by the sealing member 28 provided on the diaphragm 25 and the outer support 22, respectively, and the O-ring 27
A lubricant such as grease can be applied to the seal member 28.

On the other hand, the bonnet 17 has a cylinder 30 in which a piston 21 slides closely, a pressure chamber 31 defined by the piston 21 communicates with a pilot port 32, a breathing chamber 33 has an inspection window 34, ...
It communicates with the outside through (only one place is shown).

In the first embodiment described above, in the illustrated state in which the inlet 10 and the circulation port 11 communicate with each other, the paint is circulated by the pump (not shown) and the outlet 13 is closed.

When pressure fluid is supplied from the pilot port 32 to the pressure chamber 31, the piston 21, the valve rod 12 and the like move downward in the figure, so that the seal portion 14 opens the valve seat 3a and the inner support 19 that also serves as the seal portion opens the valve seat. 15 closed, paint exits
It flows from 13 to the recess 6. In this case, the closing of the valve seat 15 by the inner support 19 does not necessarily have to be reliably performed.

When the fluid in the pressure chamber 31 is discharged, the piston 21, the valve rod 12 and the like return to the state of FIG. 1 by the urging force of the spring 23.

In the first embodiment, since the space between the valve body 1 and the drive unit 2 is sealed by the diaphragm 25, the lubricant is not mixed in the fluid such as paint, and the trouble due to the mixing of the lubricant can be prevented and the spring can be prevented. The rusting of 23 can also be prevented.

Further, the pressure receiving area of the outer side portion of the diaphragm 25 that bulges toward the drive unit 2 side is reduced by the outer support 22 that supports the diaphragm 25 from the drive unit side, and the inner side portion restricts the displacement of the diaphragm 25. Since the valve 25 is supported by the valve body 1 side by the valve 19, the diaphragm 25 maintains its bulged state on the drive unit 2 side both during opening and closing of the flow path due to displacement of the diaphragm 25 and after opening and closing the flow path. Therefore, since the stress is not concentrated and does not act, there is no risk of damage even if the fluid pressure becomes high, and the balance of the valve rod 12 is not lost.

Further, since both the valve rod 12 and the cylinder shaft 20 are doubly sealed, even if the diaphragm 25 is damaged or the metal seal material 26 is poorly sealed, the fluid is temporarily prevented from flowing out. O-ring 27 and sealing member 28
Lubricant can be applied to prevent these abrasions, and the inspection window 34 allows confirmation of movement of the valve rod 12 and leakage of fluid.

Further, since the inner support 19, the diaphragm 25, the cylinder shaft 20, the outer support 22, the spring 23, and the piston 21 can be assembled from the other end side of the valve rod 12, they can be easily assembled.

FIG. 2 shows the second of the present invention in which the fluid switching valve is a 2-port valve.
The valve body 41 of the second embodiment has substantially the same shape as the valve body 1 of the first embodiment, and the circulation port is omitted.

Since the other structure of the second embodiment is the same as that of the first embodiment, the same reference numerals are given to the main parts of the drawing, and the detailed description will be omitted.

The action of the second embodiment is that the fluid such as paint does not circulate,
This is the same as the first embodiment except that the inner support 19 functions as a stopper for the valve rod 12.

Although the above-mentioned embodiments are all paint supply valves, the present invention is not limited to this and can be used for liquids or gases other than paint.

[Brief description of drawings]

1 and 2 are vertical sectional views of different embodiments of the present invention. 1,41 …… Valve body, 2 …… Drive unit, 10 …… Inlet, 11 ……
Circulation port, 12 …… valve rod, 13 …… outlet, 14, …… seal part, 1
9 …… inner support, 22 …… outer support, 25 …… diaphragm.

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Masaki Sato 6-19-1 Inari, Soka-shi, Saitama SMC Corporation Co., Ltd. (72) Inventor Kiyoshi Hasegawa 6-19-1 Inari, Soka-shi, Saitama SMC Inside the grass processing plant (72) Inventor Toyonobu Sakurai 6-19-1 Inari, Soka City, Saitama SMC Co., Ltd. Inside the grass processing plant (56) References 60-126775 (JP, U) Actual 61- 204084 (JP, U)

Claims (1)

(57) [Scope of utility model registration request] 1. A valve body having a plurality of ports and a flow path communicating with these ports, a valve rod having a seal portion for opening and closing the flow passage, a drive portion for driving the valve rod, In a fluid switching valve including a diaphragm that seals between a valve body and a drive unit, an outer portion of the diaphragm is supported by an outer support for reducing a pressure receiving area of the diaphragm from the drive unit side, and an inner portion of the diaphragm is connected to the valve rod. It is supported from the valve body side by the inner support that moves integrally and controls the displacement of the diaphragm, and swells to the diaphragm drive unit side both during opening and closing of the flow path and after opening and closing the flow path. A fluid switching valve characterized in that the state is maintained so that stress is not concentrated on the diaphragm and acts on it.