JP2003301954A - Check valve and manufacturing method thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve the problem of a current lift type check valve where a face- to-face distance L of a valve box is long because a lower guide is arranged under a valve seat, the whole of a valve device is large as to the lift type check valve with the structure, and it is necessary to support an upper part and a lower part of a valve element through an upper guide and a lower guide freely to slide in the vertical direction in the inner wall of the valve box to prevent the generation of tilting and eccentricity of the valve element in relation to a valve seat when opening and closing the valve. <P>SOLUTION: The lower guide is formed in the inner wall of the valve box at a position higher than the valve seat, and the periphery of a valve plate is directly supported by the lower guide freely to slide in the vertical direction. Similarly with a current device in the upper part of the valve element, an upper end of a valve rod is supported by the upper part of the inner wall of the valve box through the upper guide. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lift-type check valve of a quick closing type having a spring built therein to prevent a water hammer.

[0002]

2. Description of the Related Art As a lift type check valve having a built-in spring for preventing a water hammer, there is a structure shown in FIG. In FIG. 4, 21 is a valve box,
22 is a valve element, 23 is a valve seat, 24 is a valve rod, 25 is a lower guide, 26 is an upper guide, 27 is a valve spring, 28 is a buffer umbrella, 29 is a seat packing, and 30 is a bypass valve. In such a device, the water that pressurizes the lower surface of the valve body 22 pushes up the valve body 22 against the valve spring 27.
It flows upward through the annular space between the valve body 22 and the valve seat 23. When the water flow below the valve body 22 stops, the valve spring 2
The valve body 22 descends by the elasticity of 7 and closes the valve. At this time, the water on the upper side of the valve body 22 has not started to descend, so that no water hammer is generated. The lower guide 25 and the upper guide 26 prevent the eccentricity and inclination of the valve body 22.

[0003]

In the lift type check valve shown in FIG. 4, since the lower guide 25 is provided below the valve body 22, the face-to-face distance (height) L of the valve box 21 is reduced. Becomes longer, the shape of the valve box 21 becomes larger, and the weight increases. The present invention shortens the face-to-face distance L of the valve box,
The purpose is to solve the above problems.

[0004]

A guide member corresponding to the lower guide 25 of FIG. 4 is formed on the inner wall of the valve box above the valve seat.

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described in detail based on the embodiments shown in FIGS.

Reference numeral 1 is a valve box cast from cast iron, stainless steel or the like, 2 and 3 are upper and lower water passages provided on the upper and lower surfaces of the valve box 4, and 4 is a circular valve plate 5 and the center of the valve plate 5. A valve body consisting of a valve rod 6 protruding upward from the valve body, 7 a valve seat formed on the inner wall of the valve box 1 around the lower water passage 3, and 8 a central axis 0 of the valve box 1.
Four lower guides, which are arranged symmetrically with respect to −0 and project from the inner wall of the valve box 1 and are parallel to each other, support the valve plate 5 slidably in the vertical direction, and 9 is inside the valve box 1 and the valve. It is provided on the top of the box 1, and the valve rod 6 is attached to the central axis (0-
0) an upper guide slidably supported along the reference numeral 10, 10 is a spring elastically mounted between the valve plate 5 and the upper guide 9 to press the valve plate 5 downward, 11 is a lower center bolt of the valve body 4, 12 is a seat packing below the valve plate 5, and 13 and 14 are 0 of the valve body 4.
A ring and a contact plate, 15 and 16 are washers and nuts for fixing the seat packing 12, 17 is a bypass opening inside the valve box 1, and 18 is a bypass valve for opening and closing the bypass 17.

As shown in FIGS. 2 and 3, the inner edges of the four lower guides 8 form a guide surface 8'in the direction of the central axis 0-0 with respect to the outer circumference of the valve plate 5, so that the valve plate 5 has a guide surface 8 '. With a cutting tool with a diameter slightly larger than the outer diameter,
It is cut into a cylindrical surface extending in the −0 direction.

In FIG. 1, the water that pressurizes the lower surface of the valve body 4 pushes up the valve body 4 against the spring 10, passes through between the seat packing 12 of the valve plate 5 and the valve seat 7, and moves upward. Flowing. When the water flow below the valve body 4 is stopped, the elasticity of the spring 10 causes the valve body 4 to descend and close the valve. At this time, since the water on the upper side of the valve body 4 has not started to descend, no water hammer is generated. The guide surface 8'of the lower guide 8 is the valve plate 5
Since the upper guide 9 guides the vertical movement of the valve rod 6, the valve body 4 does not cause eccentricity and tilt,
The vertical movement of the valve element 4 is smoothly performed.

[0009]

According to the present invention, since the lower guide for guiding the lower part of the valve body in the vertical direction is arranged above the valve seat, the valve box is lower than the prior art in which the lower guide is arranged below the valve seat. The distance L between the surfaces is shortened, and the entire valve device is downsized. Further, according to the present invention, the lower guide that slidably supports the valve plate in the vertical direction is formed by four plate-like members that project from the inner wall of the valve box and are arranged in parallel. Compared with the conventional cast iron check valve in which members are arranged radially, the mold can be manufactured easily and the cost of the valve device can be reduced.

[Brief description of drawings]

FIG. 1 is a vertical sectional view of an embodiment of a check valve of the present invention.

FIG. 2 is a vertical sectional view of a mold diagram of the check valve shown in FIG.

3 is a cross-sectional view taken along the line AA of FIG.

FIG. 4 is a vertical sectional view of a conventional check valve.

[Explanation of symbols]

1 valve box 2 upper water passage 3 Lower water passage 4 valve body 5 valve plate 6 valve rod 7 seat 8 Lower guide 8'guide 9 Upper guide 10 springs

   ─────────────────────────────────────────────────── ─── Continued front page    F term (reference) 3H058 AA03 BB13 BB22 BB29 CA04                       CC02 CD05 EE02                 3H066 AA01 BA05 BA17 EA36

Claims (2)

[Claims] 1. A valve body (4) comprising a circular valve plate (5) and a valve rod (6) projecting upward from the center of the valve plate (5),
A generally cylindrical valve box (1) having a water inlet (2, 3) above and a valve body (4) installed vertically, and an inner wall of the valve box (1) around the lower water inlet (3). The formed valve seat (7) and four valve plates (5) arranged symmetrically with respect to the central axis (0-0) of the valve box (1) and projecting from the inner wall of the valve box (1), respectively. ) Is slidably supported in the vertical direction, and a lower guide (8) is provided inside the valve box (1) and above the valve box (1), and the valve rod (6) is attached to the valve box (1). Central axis (0-
0) an upper guide (9) slidably supported along with a spring (1) for pressing the valve body (4) against the valve seat (7).
0) and a check valve which is configured to prevent the occurrence of a water hammer when the valve is closed. 2. A method for manufacturing a check valve according to claim 1, wherein the valve box (1) and the lower guide (8) are integrally cast, and the inner edge of the lower guide (8) is a valve plate. A method for manufacturing a check valve, characterized by cutting corresponding to the outer periphery of (5) to form a guide surface (8 ') for the valve plate (5).