JPH0210310B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a packing for a fluid switching valve applied to food machinery such as bottles, cans, and barrel fillers.

(Prior Art) A conventional example of the fluid switching valve will be explained with reference to FIG.
4 and 5, and a spool 6 that is slid by being fitted into the cylindrical hole 2 is provided with an annular recess 6c for forming an internal flow path that switches and communicates between the flow paths 3, 4, and 5, and has a plurality of ring grooves. 6b is fitted with O-rings 7, 8, and 9 to seal the annular recess 6c from the outside air,
A stopper 6a and a contact surface 6d are provided at the upper and lower ends,
The spool 6 is slid by a cam or the like (not shown) that is in contact with the contact surface 6d, and as shown in FIG. The structure is such that it can be switched to communicate only the channels 3 and 4 or communicate only the channels 3 and 5 by sliding.

In addition, a gasket that forms an internal flow path is inserted into a valve body having multiple flow paths, and a spool for opening and closing the flow path inserted into the gasket slides to open and close a gasket provided in the center of the gasket. Fluid switching valves have also been developed and proposed that open and close internal flow passages by expanding and contracting outer protrusions or inner and outer protrusions. (For example, Japanese Patent Publication No. 44-11513) (Problems to be Solved by the Invention) The conventional fluid switching valve, shown in FIG. 1 in the packing, seals the annular recess of the spool from the outside air. Therefore, it is necessary to fit multiple O-rings onto the spool, and when the spool slides, the O-rings get caught on the corners of the flow path and are damaged, causing hot sanitation (85~ (95°C), the O-ring becomes dry and its sliding resistance increases, causing further damage and fatigue.Furthermore, as the O-ring slides against the cylindrical hole, dirt and debris adhering to the outer surface of the spool and the inner surface of the cylindrical hole are removed. Lubricant, moisture, etc. are likely to be sucked into the internal flow path, resulting in hygiene problems and problems such as reduced fluid circulation and spool slidability.

The fluid switching valve has a gasket for forming an internal flow path, which eliminates the need for an O-ring on the spool. Since an outer protrusion is provided on the outer periphery of the central part of the part, and the spool with a large diameter part or a small diameter part slides and expands and contracts over the entire area of the cylindrical main part, damage and fatigue of the thin cylindrical main part are significant. The cross-sectional area of the internal flow path formed by the packing changes, making it difficult to open and close, resulting in problems with operational reliability and durability. In addition, there is also one in which inner and outer protrusions are provided protruding in the center and outer circumference of the cylindrical main body, and the spool slides only on the inner protrusions, but a small hole is provided in the cylindrical main body and inside It is necessary to introduce a fluid to increase the internal pressure and provide a mechanism to prevent the spool from sliding against the cylindrical main body, which causes hygienic problems such as dirt entering and accumulating inside the cylindrical main body. , the slidability of the spool deteriorates, the inner and outer protrusions tend to collapse due to deformation and fatigue of the cylindrical main body, and the expansion and contraction performance of the inner and outer protrusions deteriorates, resulting in poor operational reliability and durability. There's a problem.

Furthermore, both of the gaskets have a large, elongated shape that is fitted over the entire length of the cylindrical hole of the valve body, and there is a problem in that the replacement of the expensive gaskets significantly increases the cost.

The present invention was developed to address the above-mentioned problems, and its purpose is to:
In addition to being significantly smaller and more compact, it also improves the sealing performance of the seal lips on the outer periphery of both ends that form the internal flow path, reducing damage and fatigue on the cylindrical main body, and improving the expandability and operational reliability of the inner and outer protrusions. An object of the present invention is to provide a gasket for a fluid switching valve that has improved properties.

(Means for Solving the Problems) The present invention forms an internal flow path that is inserted into a cylindrical hole of a valve body and opened and closed between flow paths for fluid inlet and output, and which is inserted into the cylindrical hole. A fluid switching valve packing that is fixed with a packing holder and expanded and contracted by a spool in the packing holder, includes a flexible cylindrical main body whose inner surface and both sides are supported by the packing holder, and the cylindrical main body. a seal lip that protrudes from the outer circumferential side of both ends of the seal lip and has a seal side surface that is supported by the seal circumferential surface and the packing retainer; A structure comprising a resilient outer protrusion having a curved contact portion for opening and closing the flow path, and an inner protrusion having a curved contact portion protruding from the inner peripheral side of the central portion of the cylindrical main body and expanded and contracted by the spool. It has the characteristics of a flexible cylindrical main body whose inner surface and both sides are supported by packing holders, making it smaller and more compact, and eliminates sliding. Both seal lips are provided with a protruding seal peripheral surface and a seal side surface to improve the sealing performance of the internal flow path, and curved contact portions are provided on the inner and outer protrusions that protrude inside the central part of the cylindrical main body and on the outer circumferential side. , the expansion and contraction performance of the inner and outer protrusions by the spool is improved, allowing smooth opening and closing of the flow path.

(Function) The seal is fitted into the cylindrical hole of the valve body to form an internal flow path that is opened and closed between the fluid inlet and outlet channels, and is also attached to the inner and side surfaces of the cylindrical body by the seal retainer. is supported and fixed at a predetermined position between the flow paths, and excellent sealing performance of the inner flow path is obtained by the seal side surfaces and seal peripheral surfaces protruding from both seal lips. Due to the curved contact portion of the inner protrusion protruding from the inner periphery of the central part, the spool inside the packing presser slides and engages smoothly, allowing the inner and outer protrusions to expand and contract smoothly without any particular collapse. The internal flow path formed on the outer periphery of the cylindrical main body opens and closes smoothly, and the curved contact portion provided on the outer protrusion reduces fluid resistance at the opening/opening portion of the internal flow path, preventing dirt from stagnation. , prevents adhesion, etc., and provides excellent opening/closing reliability.

(Embodiment) Figures 2 to 4 show a first embodiment of the present invention, where Figure 2 shows a seal, and Figures 3 and 4 show how it is applied as a fluid switching valve. Patchkin, 15 is the valve body, 17 is the spool, 18, 19
is a packing holder, which is fitted into the cylindrical hole 16 of the valve body 15 to open the channels 13 and 14 for fluid inlet and outlet.
A gasket presser 1 is fitted into the cylindrical hole 16 and forms internal channels b-21 and 22 that are opened and closed between the two.
A flexible cylindrical main body part 11a whose inner surface and both sides are supported by the packing holders 18 and 19,
A seal peripheral surface 11'b and seal retainers 18, 19 are provided protruding from the outer peripheral side of both ends of the cylindrical main body portion 11a.
The seal lip 11b has a protruding seal side surface 11''b that is supported by the cylindrical main body 11a, and a curved contact portion that protrudes from the outer periphery of the central part of the cylindrical main body 11a and opens and closes the internal flow path b by expanding outward. The gasket for the fluid switching valve is equipped with an outer protrusion 11c that has a resilient property, and an inner protrusion 11d that protrudes from the inner peripheral side of the central part of the cylindrical main body 11a and has a curved contact portion that is expanded and contracted by the spool 17. .

The packing 11 shown in FIG. 2 is entirely molded from a flexible, elastic and restorable material such as rubber or synthetic resin, and has a flexible, stretchable cylindrical main body 11a. The cylindrical main body portion 11a has seal lips 11b, 11 protruding from the outer periphery of both ends.
b. Outer protrusion 1 protruding from the outer circumferential surface at approximately the center
1c, and an inner protrusion 11d protruding inside the outer protrusion 11c are integrally formed, and a seal circumferential surface 11'b is formed on the outer periphery of the seal lips 11b, 11b.
A seal side surface 11''b is protruded from the sides of the seal lips 11b, 11b, and the inner and outer protrusions 11c, 11d are wide as shown in the figure to form a curved contact portion. Cylindrical main body part 1
Flexibility and elasticity of 1a and inner and outer protrusions 11d, 1
Due to the elasticity of the spool 1c, the outer protrusion 11c along with the inner protrusion 11d expands in diameter and protrudes toward the outer periphery in the large diameter portion of the spool 17, and contracts in diameter and returns to its original state in the recess 17a of the spool 17.

The fluid switching valve 12 of the present invention to which the gasket 11 is applied is as shown in FIG.
A cylindrical hole 16 is provided through the cylindrical hole 16, and a plurality of fluid inlet/outlet channels 13, 14 (which can be expanded) are provided on both sides, and the channels 13, 14 are arranged with a vertical difference. The packing 11 is inserted into the cylindrical hole 16, and the upper and lower packing holders 1, which have an insertion hole for the spool 17, are placed in a position where the flow passages 13 and 14 are arranged between the seal lips 11b and 11b.
8 and 19 are inserted into the cylindrical hole 2 from above and below, and both side surfaces and the inner surface of the packing 11 are covered, supported and fixed by the packing holders 18 and 19, and the inner surface support portions provided in the packing holders 18 and 19 are 18b,1
9b covers and supports the inner surface, and only the inner protrusion 11d protrudes inward, and the seal presser 1
8, 19 includes a spool 17 having a recess 17a.
is inserted.

The bushings 20 and 20 that guide the spool 17 are fitted to the outer ends of the bushing holders 18 and 19, and the bushings 11 are positioned to be held in the pilot holes 15a and 15a of the valve body 15, and are fitted into the valve body 15. , fixed. Boss 18 protruding outward
a, 19a and take it out from the valve body 15.

The spool 17 has a recess (groove) 17a that engages with the inner protrusion 11d and an enlarged portion 1 that continues to the recess 17a.
7b, and is slid into a predetermined position via a cam or the like by a drive source (not shown), and when the recess 17a fits the inner protrusion 11d, the inner protrusion 11d and the outer protrusion 11c contract in diameter due to restoring force, thereby closing the valve. When opened, an open flow path is formed on the outer circumferential side of the packing 11 (see FIG. 3), and the enlarged portion 17b of the spool 17 causes the inner projection 1 to open.
The diameter of the outer protrusion 11c is expanded along with 1d to close the valve, and the flow path on the outer circumferential side of the gasket 11 is closed.

As shown in FIG. 2, the outer protrusion 11c and the inner protrusion 11d of the packing 11 have a wide and curved contact portion, and as shown in FIG. The seal side surface 11″b is attached to the inner surface of the seal presser 18,
The sealing performance is ensured by closely contacting the sides of each of the parts 19 and 19.

The important requirements for the fluid switching valve 12 shown in FIGS. 3 and 4 are to prevent leakage, to secure an open circuit cross-sectional area to reduce flow resistance when the valve is opened, and to obtain operational reliability and durability. The following items are required for the packing 11 which has the following configuration.

There is no leakage from the outer corners (portions 11'b and 11''b), and the outer protrusion 11c is connected to the valve body 1.
When pressed against the cylindrical hole 16 of No. 5, there is no communication due to poor sealing between the spaces 21 and 22 separated in the internal flow path b by the outer protrusion 11c.

When the valve is opened, there is sufficient clearance (approximately 0.5 mm or more) between the outer protrusion 11c and the cylindrical hole 16 of the valve body 15;
In other words, ensure an open cross-sectional area.

Spool 1 for expanding the diameter of the outer protrusion 11c
7.The operating force must be small. That is, the inner protrusion 11d
is easy to expand and contract, and the diameter expansion of the inner protrusion 11d is effectively transmitted to the outer protrusion 11c.

For the structure of the fluid switching valve 12 to satisfy these requirements, the following items (A) to (G) are necessary and effective.

(A) There is an outer protrusion 11c at the outer central part of the packing 11 for sealing when closing, that is, for opening and closing the internal flow path b, and an inner inner part that expands and contracts in response to the movement of the spool 17 at the inner central part. Protrusion 11d
to have.

(B) The seal lip 11b provided at the outer end of the packing 11 has a seal peripheral surface 11'b or a seal side surface 11''b.

(C) The maximum outer diameter Go of the packing 11 in its natural state is Go = G + (0.4 to 1.2) mm G: Diameter of the cylindrical hole 16 mm (D) The length Ho of the packing 11 in its natural state is Ho = H + (0.2 to 1.2) = 2Hd + (9 to 14) mm H: Length of the storage part of the seal 11 determined by the seal pressers 18 and 19 mm Hd: Diameter of the channels 13 and 14 mm (E) The inner diameter elongation rate ex of the seal 11 is ex=(d-do)/d+100=20~30 d: Diameter of the enlarged part of the spool 17, which is the diameter of the spool 17 that contacts the inner protrusion 11d of the seal 11 when the valve is closed mm do: The inner protrusion 11d of the seal 11 minimum diameter of
mm (F) The effective magnification ratio η of the packing 11 is η=(d-do)/(Do-do)=0.2~0.3 Do: Maximum diameter of the outer protrusion 11c of the packing 11
mm (G) Thickness t of the cylindrical portion 11a is t = (Co-Bo)/2 = 1 to 3 mm Co: outer diameter of the cylindrical portion 11a mm Bo: same inner diameter mm Fluid switching valve shown in Fig. 2 Patsukin 11 for
has a structure that satisfies the above conditions, so
When the packing 11 is assembled into the fluid switching valve 12 as shown in FIG. 3, the seal lip 11b is pressed and fixed against the cylindrical hole 16 and the packing holders 18, 19, and the seal lips 11b, 11b at both ends of the cylindrical hole 16 are fixed. An internal flow path b is defined by the cylindrical main body portion 11a and communicates the flow paths 13 and 14, and the internal flow path b is sealed off from the outside air. The spool 17 is connected to the valve inner space 21 of the internal flow path b,
The spool 17 is slid up and down to a predetermined position via a cam or the like by a drive source (not shown), and is shown in FIG.
The spool 17 is positioned with the inner projection 11d of the packing 11 engaged in the recess 17a of the spool 17, and the inner projection 11d of the packing 11,
The outer protrusion 11c is not expanded in diameter, and the outer protrusion 11c is not expanded in diameter.
the internal flow path b between c and the cylindrical hole 16 is kept open;
The channels 13 and 14 communicate with each other.

When the spool 17 is slid to the position shown in FIG.
The inner protrusion 11d of the valve body 15 is expanded, and the outer protrusion 11c is also enlarged in diameter and pressed against the cylindrical hole 16 of the valve body 15, and the inner passage b is closed and cut off into the spaces 21 and 22, and the passages 13 and 14 are closed. The gap is cut off. The packing 11 is a flexible and elastic body, and its elastic resistance (restoring force) causes the spool 17 to receive a force directed toward its center and to be held there. When switching from the state shown in FIG. 4 to the state shown in FIG. 3, the packing 11 returns to the state shown in FIG. 3 due to its restoring force and the pressure of the fluid in the spaces 21 and 22.

Therefore, according to the fluid switching valve 12, the inner surface of the cylindrical hole 16 of the valve member, and the seal lips 11 at both ends.
b, 11b and a flexible, elastic cylindrical main body 11
An internal flow path b with no sliding parts is defined by a, and the diameter of the inner protrusion 11d, which is cut off from the fluid within the valve, is expanded (by the spool 17) to open the outer protrusion 11c.
The high-performance packing 1 has a valve opening/closing function that opens and closes the internal flow path b by expanding the diameter and divides the internal flow path b into two, and also has a sufficient sealing function with the seal lip 11b.
1, and by installing this inside the fluid switching valve 12 as shown in Fig. 3, the valve structure is simplified, and it has an excellent switching valve function and sufficient durability. .

When the spool 17 shuts off or connects the flow paths 13 and 14, the sealing member does not slide relative to each other across the flow paths 13 and 14, so dust, lubricating oil, moisture, etc. can flow inside from the outside. The fluid in the valve is not contaminated because it is not brought into the passage b and stagnates. Moreover, on the contrary, dirt, moisture, etc. do not flow into the spool 17 side from the fluid, and the spool 17 slides smoothly.

The spool 17 and the inner protrusion 11d, which control the movement of the outer protrusion 11c that directly blocks and communicates between the flow paths 13 and 14, are cut off from the fluid in the valve and released to the outside air, so the expansion and contraction of the gasket 11 is ensured. Use a suitable lubricant to increase the service life of the gasket 11.
It can be supplied to the contact portion with the spool 17 inside.

Next, FIG. 5 shows a second embodiment of the present invention, and compared to the first embodiment, the fluid switching valve is formed by incorporating two packings 11 shown in FIG. , is characterized by a configuration that blocks and communicates between the three flow paths 23, 24, and 25, and the spool 26
When is at position 26A, channels 23 and 24 are in communication, and channel 25 is blocked, and when is at position 26B,
Flow paths 23, 24, 25 are all blocked, and position 26
In case C, channels 23 and 25 are in communication, and channel 2
4 is shut off, it becomes possible to open and close two channels, and basically the same effect as in the first embodiment can be obtained.

(Effects of the Invention) The present invention has the above-described configuration, and the packing is fitted into the cylindrical hole of the valve body to form an internal flow path that is opened and closed between the flow paths for fluid inflow. At the same time, the inner and side surfaces of the cylindrical main body are supported by the packing retainer and fixed in a predetermined position between the flow channels, and the seal circumferential surface and seal side surface protruding from the seal lip provide an excellent internal flow path. Sealing performance is obtained, and the inner and outer protrusions protruding into the center and outer circumference of the cylindrical main body have curved contact parts, so that the spool smoothly slides and engages within the packing holder, allowing the inner and outer protrusions to The outer protrusion expands and contracts smoothly, allowing smooth opening and closing of the internal flow path, and the curved contact portion of the outer protrusion reduces fluid resistance at the opening and closing portion of the inner flow path, resulting in excellent opening and closing reliability. It has reduced damage and fatigue, is durable, is significantly smaller and more compact, enables cost savings, and has significantly improved fluid switching valve performance and reliability.

[Brief explanation of drawings]

FIG. 1 is a vertical cross-sectional view showing a conventional example, FIG. 2 is a vertical cross-sectional view of the packing showing the first embodiment of the present invention, and FIG. 3 is a vertical cross-sectional view of the fluid switching valve showing the packing shown in FIG. 2 in an assembled state. , FIG. 4 is a longitudinal sectional view showing the operation of FIG. 3, and FIG. 5 is a longitudinal sectional view showing the second embodiment. 11: Packkin, 11b: Seal lip, 1
1'b: Seal peripheral surface, 11''b: Seal side surface, 11
c: outer protrusion, 11d: inner protrusion, 15: valve body, 13, 14, 23, 24, 25: flow path, 1
7: Spool, 18, 19: Packing presser, 18
b, 19b: inner surface support part.

Claims (1)

[Claims] 1 It is fitted into a cylindrical hole in the valve body to form an internal flow path that is opened and closed between the fluid inlet and outflow channels, and is fixed by a packing holder fitted into the cylindrical hole and attached to a spool in the packing holder. A gasket for a fluid switching valve that expands and contracts as a result of the expansion and contraction includes a flexible cylindrical main body whose inner surface and both sides are supported by the gasket retainer, and a seal peripheral surface that protrudes from the outer circumferential side of both ends of the cylindrical main body. and a seal lip with a protruding side surface of the seal supported by the packing holder, and a curved contact portion protruding from the outer peripheral side of the central portion of the cylindrical main body and opening and closing the internal flow path by expanding outward. 1. A gasket for a fluid switching valve, comprising: an outer protrusion having a curved surface; and an inner protrusion having a curved contact portion that protrudes from the inner peripheral side of the central portion of the cylindrical main body and expands and contracts with the spool.