JP2969443B2 - Dual plate check valve - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a dual plate check valve in which two semi-disc-shaped valve elements are closed by spring tension and back pressure. The present invention relates to a dual plate check valve for preventing and prolonging the life of the valve.

[0002]

2. Description of the Related Art Conventionally, a pair (two) of semi-disc-shaped valve bodies are pivotally attached to a valve box with hinge pins while constantly biasing the valve bodies in a valve closing direction by a spring, and the valve body is spring-elasticized by fluid pressure. 2. Description of the Related Art A dual plate check valve is known which opens a valve against a spring force and closes a valve body by a spring force and a backflow pressure when a backflow occurs. And JP-A-60-173776.

Referring to FIG. 6, a check valve disclosed in Japanese Utility Model Publication No. Hei 3-2065 has a pair of hinge pins (2) inserted in the center of a valve box (1) that open and close in a flowing direction. Valve Wings (3
a) (3b) is pivotally supported, and two hinges (4) are attached to hinge pins (2).
Flange (7) that penetrates (5) and separates between adjacent ends of each hinge (4) (5) between hinge pin (2) and hinges (4) (5)
Having a structure in which a pipe bearing (6) having
The hinge part prevents friction directly on the surface of the hinge pin (2) and prevents the adjacent ends of the hinge part from sliding against each other, so that the wear of the hinge part is greatly reduced, and The service life can be extended only by replacing the pipe bearing (3). And, with such a structure, the fluid pressure and flow rate are extremely small,
The opening and closing operation of the valve blade is intense due to fluctuations or pulsations, causing a hammering phenomenon (chattering), and the area surrounding the hinge pin is worn and damaged. It is trying to solve the problem of lack of smoothness. In addition, 60-17377
In the check valve disclosed in Japanese Patent Publication No. 6, a bypass passage for bypassing and flowing down a fluid from upstream is provided to prevent a valve body from being damaged by a water hammer caused by a backflow.

However, in the structure of this known check valve, it is necessary to remove the check valve from the pipe and replace the pipe bearing, and to prevent a hammering phenomenon that causes wear and damage of the pipe bearing and the hinge. I couldn't do that. In addition, since the bypass is always open and the valve body cannot be reliably closed when the valve is closed, a relief valve (relief valve) that opens only at abnormal pressure due to the water hammer phenomenon is provided. In standard use, it was necessary to close the valve securely.

[0005]

SUMMARY OF THE INVENTION The present invention enables disassembling and assembling from the outside while bearings and the like, which are easily worn or damaged, are connected without removing the valve box. Provide two sub-valves that receive and open the valve, and open the first sub-valve to allow fluid to flow out without opening the main valve at the time of minute pressure and flow rate. Prevent the hammering phenomenon of the main cause,
Further, when an excessive pressure is generated, the second sub-valve is opened to act as a relief valve, thereby preventing a water hammer phenomenon.

[0006]

In order to solve the above-mentioned problems, the present invention is directed to a pair of main valves pivotally supported by diametrically extending hinge pins in a valve box passing through a cylindrical fluid passage. In a dual plate check valve in which a main body is pivotally supported and the main valve body is constantly urged in a valve closing direction by a spring, a plurality of openings are provided in the main valve body, and at least one of the openings is minutely arranged from an inlet side. With the first sub-valve that opens with a high fluid pressure,
The other one of the openings can be freely opened by a second sub-valve element that opens with excessive fluid pressure from the outlet side.

[0007] Further, the invention is characterized in that the shaft end of the hinge pin is inserted into a bearing plug screwed from the outside of the valve box to support the shaft.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described in detail below. Referring to the drawings, (10) is a cylindrical valve box having a fluid passage (11) penetrating therethrough and having a wafer-type structure that can be held between piping flanges and attached to piping. An annular valve seat (12) projecting toward the inner diameter direction is formed on the inner peripheral surface on the inlet side in the valve box, and a hinge pin (13) extending in the diametric direction adjacent to the annular valve seat (12) has a valve. It is inserted in the box (10). The outflow port (14) of the valve box (10) has a cylindrical shape whose diameter increases with the boundary of the annular valve seat (12).

The main valve body (15) is composed of a pair (two) of semi-disc-shaped valve bodies whose bases are rotatably supported by hinge pins (13). When seated, the valve is in a valve closing position, and the fluid passage (11) is closed. The main valve element (15) is rotated by the fluid pressure applied from the inlet side as shown by the dotted line in FIG. 1 to open the valve, and opens the fluid passage. The main valve body (15) is normally urged in the valve closing direction by receiving the elastic force of a spring (16) wound around the hinge pin (13). A central rib (17) is arranged in parallel with the hinge pin (13) across the center of the valve box (10) in the diametric direction, and projects toward the inlet side.
The central rib (17) terminates on the same plane as the valve seat surface, and has a downstream width of two main valve bodies (15) when the main valve body (15) is in the open position. The width of the shaft support end is made larger to prevent the shaft support end surface of the main valve body (15) from becoming resistant to fluid when the valve is opened.

[0010] The spring (16) stretched over the main valve body (15) is stretched one by one for each pair of two main valve bodies.
Wound around the hinge pin (13), the long shaft side free end (16a) is located at the center of the main valve body (15), and the single shaft side free end (16b) is located near the periphery of the main valve body (15). Each has a bullet. Two springs (1
A bush (18) is interposed between 6) so that the two springs do not interfere with each other and the sliding resistance is reduced.

A cylindrical bearing boss (19) is formed at a shaft support end of the main valve body (15). Two bearing bosses (19) are formed at intervals in the axial direction, one bearing boss (19a) is located in contact with the periphery of the main valve body (15), and the other bearing boss (19b) is One boss is shifted toward the center by the axial length. As a result, when the two main valve bodies (15) are combined, the two bearing bosses (19a) (19b) are coaxially aligned and axially supported, so that the two main valve bodies (15 ) Means that those having substantially the same shape need to be prepared. A bush (2) is also provided between the inner bearing boss (19b) and the spring (16).
0) is inserted. As shown in FIG. 5, a bush (21) is interposed outside the shaft support end of the main valve body (15) to prevent the main valve body (15) from moving in the shaft support direction and to reduce the sliding resistance. Has been reduced. The bush (21) is fixed to a predetermined position by a bearing plug (22) from the outside. The bearing plug (22) can be easily inserted and removed by turning the screw part of the plug even after disposition, and the shaft end of the hinge pin is tapered to facilitate insertion into the hinge pin. It is beveled. Note that a packing (23) is wound around the base of the bearing plug to prevent leakage of the fluid to the outside.

An elastic valve seat is disposed on a contact surface of the main valve body (15) which is in contact with the annular valve seat (12). When the valve is closed, the elastic valve seat is pressed against the annular valve seat to ensure a sealing property. The free ends (16a) and (16b) of the spring (16) are elastically provided on the back surface of the main valve body (15), and two stoppers (25) located near the periphery are provided. Is formed. The contact surface of the stopper (25) is the main valve element (1
5) are formed on the slopes so as to abut each other when in the valve-opening position, and a stopper pin (26) is provided in parallel with the hinge pin (13) to prevent the main valve body (15) from over-rotating. It is pivoted in the center of the box. This stopper pin (26)
A shaft end that is tapered like the hinge pin (13) is mounted on a bearing plug.

The two main valve elements (15) have a plurality of openings (27).
Is formed, and the first sub-valve element (28) and the second sub-valve element (29) are attached to the opening. These sub-valves are normally urged in the valve closing direction by a spring (30) to close the opening. Referring to FIG. 3, the first sub-valve (28) is opened by a small pressure and flow rate from the inlet side, and the second sub-valve (29) is opened in FIG. As shown in the figure, the valve is activated and opened when excessive pressure is applied from the outlet side. The two sub-valves (28) and (29) have substantially the same structure. A valve stem (31) is attached to the center of the sub-valve, and is inserted through the valve stem guide (32). The spring (30) is stretched between a valve stem guide (32) and a nut (33) screwed to the tip of the valve stem (31). The nut (33) is fixed with a split pin (34). Valve stem guide
A fluid passage (35) penetrates (32), and communicates the inlet side and the outlet side. A plurality of sub-valves are provided at the center of the main valve body, and the sub-valve seat secures seating and sealing. The sub-valve is
In order to ensure the sealing property, it can be formed of an elastic body. Further, the main valve body may be formed of an elastic body. The spring tensioned on the first sub-valve is set to a relatively low tension so as to open with a small fluid pressure and flow rate, and the spring tensioned on the second sub-valve has an excessive pressure. The tension is set to be relatively high so that the valve is opened when it is applied.

When a slight fluid pressure and flow rate is applied from the inlet side in the state where the main valve body (15) is closed, the first sub-valve body (28) opens to flow the fluid to the outlet side. This prevents hammering. Also, when an excessive fluid pressure is applied from the outlet side, the second sub-valve is opened and the excessive fluid pressure can be released to the primary side. Also, the bearing plug (22) is
It is screwed to (10), and the valve box can be screwed off from the valve box without removing the valve box after piping, so that the hinge pin, spring, bush, etc. can be replaced.

[0015]

According to the present invention, the first sub-valve that opens with a small fluid pressure and flow rate from the inlet side and the second sub-valve that opens with excessive fluid pressure from the outlet side Since the valve is provided on the main valve, chattering due to minute fluid pressure and flow rate from the inlet side can be prevented, and wear and damage of the shaft and bearings can be prevented. This prevents water hammer due to excessive fluid pressure, and prevents damage to the main valve body, the annular valve seat, and the shaft. Also, even after installing the pipe, the valve box can be worn without removing it from the pipe.
Replacement of damaged hinge pins, springs, valve bodies, bushes, etc. is possible.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of a check valve according to the present invention.

FIG. 2 is a front view, in which the right half is viewed from the entrance side,
Left half seen from exit side

FIG. 3 is a sectional view of a first sub-valve element.

FIG. 4 is a sectional view of a second sub-valve.

FIG. 5 is a sectional view showing mounting of a bearing plug.

FIG. 6 is a sectional view showing a conventional check valve.

[Explanation of symbols]

 (10) Valve case (11) Fluid passage (12) Annular valve seat (13) Hinge pin (14) Outlet (15) Main valve body (16) Spring (17) Central rib (18) Bush (19) Bearing boss ( 20) Bush (21) Bush (22) Bearing plug (23) Packing (24) Contact surface (25) Stopper (26) Stopper pin (27) Opening (28) First sub-valve (29) Second sub Valve (30) Spring (31) Valve stem (32) Valve stem guide (33) Nut (34) Split pin (35) Fluid passage

Claims (2)

(57) [Claims] 1. A pair of main valve bodies supported by diametrically extending hinge pins in a valve box penetrating a cylindrical fluid passage, and the main valve bodies are always attached in a valve closing direction by a spring. In the energized dual plate check valve, a plurality of openings are provided in the main valve body,
At least one of the openings is freely openable by a first sub-valve that opens with a small fluid pressure from the inlet side, and the other one of the openings is opened with an excessive fluid pressure from the outlet side. A dual plate check valve characterized by being freely openable with a second auxiliary valve body. 2. The dual plate check valve according to claim 1, wherein a shaft end of the hinge pin is inserted into a bearing plug screwed from outside of the valve box to support the shaft.