JPH0140381Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention relates to a valve for controlling the flow rate of a fluid in a conduit.

[Conventional technology]

As one type of valve installed in a piping system to control the flow rate of fluid, one using a seat ring and a plug as shown in FIG. 1 is known. That is, in the same figure, the cylindrical portion 6 of the upper lid 5 is fitted into the fitting hole 4 of the valve body 3, which is provided with channels 1 and 2 connected to the upstream pipe line and the downstream pipe line, respectively. Top lid 5
is connected to the valve body 3 by a bolt 7.
A guide bush 8 slidably supports the valve shaft 9, and is press-fitted into the central through-hole 10 of the upper cover 5 from the open end on the valve body insertion side. Further, a V-packet 12 is inserted into the large diameter portion of the central through-hole 10 and is prevented from coming off by a packing holder 11 that closes the opening end of the V-packet 12 and is urged toward the packing holder 11 by a ground spring 13. There is. moreover,
A seat ring 14 is screwed into the bottom of the insertion hole 4, and the tapered seating surface 14a and the valve shaft 9
The plug seating portion 9a is fitted. The fluid that has flowed into the inner chamber 15 from the upstream flow path 1 flows into the inner chamber 16 from the flow path formed by the plug seating portion 9a and the seating surface 11a, and flows through the flow path 2 to the downstream side. As the fluid flows, the flow rate is adjusted by moving the valve shaft 9 back and forth.

By the way, for valves that control special fluids such as slurry, high viscosity fluids, and chemicals, the materials of the valve body, valve stem, seat ring, etc. should be selected according to the characteristics of the fluid, and the materials should be carefully selected to prevent corrosion and wear caused by the fluid. It is also necessary to prevent fluid from entering the sliding parts. Therefore, various proposals have been made in the past, but since most valve components are made of metal, they lack chemical resistance and abrasion resistance, and the plug and seat ring in particular are susceptible to corrosion. This has the disadvantage that highly accurate fluid control cannot be performed.

Therefore, recently, valves have been proposed and implemented in which the plug and seat ring are made of ceramics to improve chemical resistance, wear resistance, etc. In that case, the coupling structure between the ceramic plug and the metal valve shaft is generally such that the plug 20 is inserted into a fitting recess 21 formed on the upper end surface of the plug 20 and the lower end surface of the valve shaft 9, as shown in FIG. The valve shaft 9 and the plug 20 are integrally provided with cylindrical projections 22, and the gap between these projections 22 and the fitting recess 21 is filled with an adhesive 23, thereby integrally joining the valve shaft 9 and the plug 20.

However, in such a coupling structure, since the metal and ceramic are in contact with each other, when an impact operation is performed such as when rapidly opening and closing a valve, the protrusion 22 is pressed against the inner bottom surface of the fitting recess 21, and the plug 20 itself is damaged. There was an inconvenience that the product was damaged or damaged.

[Summary of the idea]

The present invention has been developed in view of the above-mentioned points, and includes an elastic member disposed in a compressed state in a fitting recess formed in an adapter attached to a valve stem and into which a part of a plug made of a brittle material is fitted. It is an object of the present invention to provide a valve that can prevent damage to the plug by an extremely simple structure in which the impact of the plug is absorbed and alleviated by the elastic member when the valve operates under impact.

Hereinafter, the present invention will be described in detail based on embodiments shown in the drawings.

〔Example〕

FIG. 3 is a sectional view of a fluid control member showing a first embodiment of the valve according to the present invention, 9 is a metal valve stem, 30 is an adapter also made of metal, 31 is a plug made of a brittle material such as ceramics, 32 is also a brittle material such as ceramics or a sheet ring.

A male threaded portion 33 is formed at the lower end of the valve shaft 9, and this male threaded portion 33 is screwed into a threaded hole 34 formed at the center of the upper end surface of the adapter 30, and is inserted into the upper end of the adapter 30. A pin 35 driven in the diametrical direction prevents the valve shaft 9 from coming off, thereby integrally connecting the valve shaft 9 and the adapter 30. On the other hand, a fitting recess 37 is formed at the center of the lower end surface of the adapter 30 to house a compression coil spring 38 as an elastic member and into which a protrusion 36 integrally protruding from the center of the upper end surface of the plug 31 can fit. has been done. The compression coil spring 38 is connected to a small diameter recess 37 provided on the inner bottom surface of the fitting recess 37.
The protrusion 36 is stored in a compressed state within the fitting recess 37, and its lower end is pressed against the upper end surface of the protrusion 36, thereby biasing the protrusion 36 in the direction of protruding from the fitting recess 37.

A tapered neck portion 40 whose diameter becomes smaller toward the plug body is provided at the center of the protrusion 36, and an arbitrary number of neck portions are provided on the outer peripheral surface of the lower end portion of the adapter 30 corresponding to the tapered neck portion 40. A screw hole 41 is formed and communicates with the fitting recess 37 . This screw hole 41 is formed obliquely so as to be substantially perpendicular to the surface of the tapered neck portion 40, and a screw 42 is screwed into the screw hole 41. The distal end surface of the screw 42 is flat and is pressed into contact with the tapered neck portion 40 . In this case, rotation of the plug 31 can be prevented by forming the portion of the tapered neck portion 40 that the tip end surface of the screw 42 comes into contact with into a flat surface and bringing the surface into surface contact. Further, when the screw 42 is tightened and pressed against the tapered neck portion 40, a component of the pressing force at this time acts to push the protrusion 36 upward, increasing the elastic force of the compression spring 38 and increasing the resiliency of the fitting recess. 37 for abutting engagement with the tapered neck 40.
from coming out of the fitting recess 37.

The valve shaft 9 and the seat ring 32 to which the plug 31 is attached via the adapter 30 are incorporated into the valve body as in the conventional structure shown in FIG. The flow rate of the fluid is adjusted by the hole 32a.

According to the plug-adapter coupling structure having such a configuration, even if the plug 31 receives a large upward impact during rapid opening and closing of the valve, the compression coil spring 38 absorbs the impact, and the protrusion 36 Since the upper end surface of the plug 31 is prevented from coming into contact with the inner bottom surface of the fitting recess 37, the plug 31 itself will not be damaged or broken, and a valve with excellent durability can be obtained. In addition, the compression coil spring 38 absorbs processing and assembly errors of the valve stem 9, plug 31, adapter 30, etc., so that no unreasonable force is applied to the plug 31 when fully closed, and the plug 31 is placed evenly on the seat surface of the seat ring 32. The amount of leakage can be reduced.

FIG. 4 is a sectional view showing a second embodiment of the present invention. In this embodiment, the plug 31 is inserted into the fitting recess 37 of the adapter 30 via an elastic member 50 made of rubber or the like.
The other configurations are the same as those of the first embodiment. It is clear that the same effects as in the above embodiment can be obtained also in such a configuration.

FIG. 5 is a sectional view showing a third embodiment of the present invention. In this embodiment, a plug 53 is attached to the lower end of the valve shaft 9 via first and second adapters 51 and 52, and the first adapter 51 and the valve shaft 9 are similar to those in the first and second embodiments. Similarly, the male threaded portion 55 is screwed into the screw hole 54 and is integrally connected with the pin 56. Similarly, the second adapter 52 is also screwed into a male threaded portion 57 provided at the lower end of the first adapter 51, and is integrally coupled to the first adapter 51 by a taper pin 58. Said second adapter 5
2 is formed into a hollow cylindrical shape with openings at both ends, the upper end of the center hole constitutes a screw hole 59 into which the male threaded portion 57 is screwed, and the lower end constitutes a fitting recess 60 for the plug 53. There is.

The plug 53 disposed in the fitting recess 60 is prevented from coming off downward from the second adapter 52 by integrally having a large diameter part 53a at its upper end, and the characteristic part 53b is connected to the second adapter 52. It protrudes to the outside from the lower end opening of 52. and,
The upper surface of the large diameter portion 53a and the first adapter 51
An elastic member 61 made of rubber or the like is interposed in a compressed state between the lower end surface and the lower end surface. In this case, instead of the elastic member 61, a compression coil spring 52 may be assembled in the second adapter 52 in a compressed state as shown in FIG. Note that the second adapter 52 is connected to the plug 5 in advance.
3 and the elastic member 61 are attached, the tapered pin 5 is screwed into the threaded portion 57 of the first adapter 51.
8 is driven in, so that it is integrally coupled to the first adapter 51. Further, the lower end surface of the first adapter 51 constitutes the inner bottom surface of the fitting recess 60.

It will be obvious that even with such a configuration, the plug 53 can be prevented from being damaged or broken during impact operation of the valve.

[Effect of idea]

As explained above, in the valve according to the present invention, the plug is formed of a brittle material such as ceramics, and a part of the plug is fitted into the fitting recess of the adapter attached to the valve shaft, and the plug is inserted into the fitting recess. Since the elastic member is arranged in a compressed state to urge the plug in the direction of protruding from the fitting recess, the elastic member absorbs the impact that acts on the plug when the valve is rapidly opened and closed. It can be relaxed. Therefore, the plug does not come into contact with the inner bottom surface of the fitting recess, thereby preventing the plug from being damaged or broken, thereby improving durability.

In addition, the structure is simple and the work of assembling the elastic member is easy.Moreover, the elastic member absorbs machining and assembly errors of the valve stem, plug, adapter, etc., so that the plug contacts the seat surface of the seat ring uniformly. Its practical effects are very large, such as improving the closing characteristics when closed and reducing the amount of leakage.

[Brief explanation of drawings]

Fig. 1 is a sectional view showing an example of a conventional valve, Fig. 2 is a partially cutaway front view showing a conventional coupling structure of a metal valve shaft and a ceramic plug, and Fig. 3 is a valve according to the present invention. FIG. 4, FIG. 5, and FIG. 6 are cross-sectional views showing the second, third, and fourth embodiments of the present invention, respectively. 9...Valve stem, 30...Adapter, 31...Plug, 36...Protrusion, 37...Fitting recess, 38...
Compression coil spring, 50... Elastic member, 51... First adapter, 52... Second adapter, 53... Plug, 60... Fitting recess, 61... Elastic member, 6
2...Compression coil spring.

Claims (1)

[Scope of utility model registration request] The valve stem includes a valve stem and a plug formed of a brittle material and attached to the valve stem via an adapter, and an elastic member is compressed into a fitting recess provided on the adapter and into which a part of the plug is fitted. A valve characterized in that the plug is biased in a direction in which the plug is protruded from the fitting recess.