JPH0972441A - Swing check valve - Google Patents

Abstract

PROBLEM TO BE SOLVED: To allow a valve body formed as one member composed of a body part, an arm part, a boss part to be provided with an aligning function, and line all fluid contact surfaces of parts constituting a valve with resin. SOLUTION: A valve body 25 is composed of a disc (body) part 27, an arm part 29, a boss part 31, and a stopper part 33. A swing rod 15 is made of a cylindrical rod part and square rod parts on its both ends. The boss part 31 is loose-fitted on the cylindrical rod part of the swing rod 15. The square rod parts are supported in bushes. Holes in the bushes are extended in the direction crossing a dotted line or the center axis-line of a valve seat 11 at a specified angle. Consequently, the valve body connected to the swing rod can move and be aligned in the direction in which the hole of the bush is extended. The fluid contact parts of the valve box, the valve body, the the bushes, the swing rod, etc., are lined-processed with resin 51.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a swing check valve.

[0002]

2. Description of the Related Art A swing check valve is one of valve devices having a function of stopping a reverse flow of fluid. A fluid passage having a valve seat is defined in the valve box of the swing check valve. A swing rod is provided near the upper portion of the fluid passage in a direction orthogonal to the fluid passage. A boss portion, which is one end of a swing arm, is loosely fitted on the swing rod. A substantially disc-shaped valve element is connected to the other end of the swing arm so as to be in close contact with the valve seat. Regarding this connection, in the conventional swing check valve, a male threaded portion is provided on the valve body and a female threaded portion is provided on the swing arm and they are connected by screw means, or a convex portion is provided on the valve body and a concave portion is provided on the swing arm. It was often the case that parts were provided and joined by concavo-convex fitting. And, in the case where they are joined by the fitting of the concavities and convexities, by fitting them in a mode with a backlash, the valve body can be correctly attached to the valve seat even if there is some error in the positional relationship between the valve seat and the valve body. It had a self-aligning function of closely contacting. In the swing check valve, when the fluid starts to flow back, the valve body comes into close contact with the valve seat of the valve box to prevent the backflow.

Further, the swing check valve may be arranged in a flow path pipe through which a corrosive fluid flows. Conventionally, in such an arrangement, a swing check valve formed of a material having good corrosion resistance such as a stainless steel material or a resin material has been used. However, the swing check valve made of stainless steel material has good normal corrosion resistance, but it may cause electrolytic corrosion (a type of electrochemical corrosion) between parts made of dissimilar metals, or may have holes in the valve box. There was a risk of eating, and it was also expensive. On the other hand, the swing check valve made of a resin material has a risk of being partially damaged due to collision of flying objects and addition of external force.

[0004]

As a countermeasure against the corrosion of the swing check valve, it is effective to apply a non-metal lining such as resin to the surface of the valve component that comes into contact with the corrosive fluid. However, in the above-described conventional swing check valve, it is practically impossible to perform lining on the connection portion by fitting the screw means or the concavity and convexity. Further, if the valve body and the swing arm are manufactured as an integral member from the beginning so that the lining process can be performed, there is a problem that the automatic centering function as described above cannot be provided. Therefore, the present invention has the function of aligning the valve body formed as one member consisting of the main body portion, the arm portion, and the boss portion, and can perform the lining processing on all the fluid contact surfaces of the valve component. It is intended to provide a swing check valve.

[0005]

To achieve the above object, a swing check valve according to the present invention is a valve formed by a valve box having a valve seat and a main body portion, an arm portion and a boss portion as one member. A body, a swing rod in which the boss portion is loosely supported to swingably support the valve body, and a support member having a shaft hole that accommodates both ends of the swing rod, and at least the valve box and the valve body The swing rod and the fluid contact portion of the support member are lined, and the shaft hole has the valve seat so as to allow the swing rod to move along the inner surface of the shaft hole. Extends downward at a predetermined angle with respect to the central axis of the. Further, a stopper portion is provided on the back surface of the valve body, and the stopper portion is covered with a rubber protection member.

In the swing check valve of the present invention having the above structure, when the fluid flows into the fluid passage of the valve box,
Fluid pressure acts on the front surface of the valve body. Due to this fluid pressure, the valve body is separated from the valve seat, and the fluid flows toward the outlet of the fluid passage. The valve body moves until the stopper portion contacts the valve box. At this time, the stopper portion is covered with the rubber protective member, so that the lining process of the contact portion of the valve box is not damaged. When the fluid in the fluid passage tries to flow backward, the valve body starts to close due to its own weight or the pressure acting on the back surface of the valve body, and engages with the valve seat to block the fluid passage and prevent the fluid from flowing backward. Also, even if there is some manufacturing tolerance in the valve body, swing rod, valve seat, etc., the valve body can move due to the centering function, so the fluid pressure acting on the rear surface of the valve body causes the valve body to seal to the valve seat. It adheres in a stopped state.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION Preferred embodiments of the present invention, that is, embodiments will be described in detail with reference to the accompanying drawings. In the drawings, the same reference numerals indicate the same or corresponding parts. In the following description, the inlet 9a side of the fluid passage 9 in FIG. 1 is defined as “front”, the outlet 9b side is defined as “rear”, and the direction perpendicular to the plane of FIG. 1 is defined as the “left / right” direction.

FIG. 1 is a sectional view of the swing check valve 5 of this embodiment. In FIG. 2, line II- in FIG.
A sectional view of the swing check valve 5 in II is shown. In the valve box 7, the inlet is 9a and the outlet is 9b.
A fluid passage 9 indicated by is defined. An annular valve seat 11 is formed in the fluid passage 9. The upper portion of the valve box 7 is open, and parts can be taken in and out of the fluid passage 9 and maintenance can be performed through the opening 7a. The opening 7 a at the top of the valve box 7 is covered by the valve lid 13. The valve lid 13 is attached to the valve box 7 by fastening means such as bolts through a proper gasket (not shown) between the valve lid 13 and the valve box 7. As shown in FIG. 1, a resin lining 51 is applied to the inner wall surface of the valve box 7 that defines the fluid passage 9 and the upper opening. Also, the valve lid 1
A resin lining 51 is similarly applied to the inner surface of the No. 3.

A swing rod 15 is arranged above the fluid passage 9 in a direction orthogonal to the fluid passage 9. The swing rod 15 is a shaft member in which most of the portion is cylindrical (cylindrical portion 15b) and both ends are quadrangular prism (square column portion 15a).

The swing rod 15 is supported by inserting the square pole portions 15a at both ends thereof into the holes 17a of the bush 17. The bushes 17 are arranged in side holes 19 formed in both left and right sides of the valve box 7. The side hole 19 is
It is covered by the side cover 21. The side cover 21 is attached to the valve box 7 by fastening means such as bolts. A part of the side cover 21 is inserted into the hole 17a of the bush 17 so that the bush 17 does not move when the valve body 25 moves. Then, the swing rod 15 supported as described above also
When the valve body 25 moves, it does not move. Therefore, when the valve body 25 rotates, the outer surface of the swing rod 15 and the inner surface of the boss portion 31 of the valve body 25, which will be described later, are in a sliding relationship with each other. As is clear from FIG. 2, the surface of the swing rod 15, the outer surface of the bush 17, the inner surface of the hole of the bush 17, and the inner surface of the side hole 19 are provided with the same resin lining as described above.

In the swing check valve 5 of this embodiment, the disc portion 27 of the valve body 25 is hard to be completely adhered to the valve seat 11 due to manufacturing tolerances of the valve body 25, the swing rod 15, the valve seat 11, and the like. In case of failure, an automatic centering function with a structure different from the conventional one is provided. This will be described below. FIG. 3 is a sectional view taken along line III-III in FIG. The dotted line Y in FIG. 3 is substantially parallel to the dotted line X in FIG. 1, which is the central axis of the valve seat 11.
The dotted line Z is inclined by an angle θ from the dotted line Y so that the front side of the swing check valve 5 is below the dotted line Y and the rear side thereof is above. The hole 17a of the bush 17 has a rectangular cross section and extends in the direction of the dotted line Z. A gap 23 is formed between the inner surface of the hole 17a and the outer surface of the square pole portion 15a inserted therein. Therefore, the swing rod 15 including the square pole portion 15a, in other words, the swing rod 15 and the valve body 25 are provided in the hole 17a.
Can be slid in the extension direction of a distance corresponding to the gap 23. Further, the valve body 25 is allowed to move slightly not only in the front-rear direction but also in the left-right direction due to the existence of the gap 24 shown in FIG. By the above,
The "deviation" due to the manufacturing tolerance between the valve body 25 and the valve seat 11 is offset. When the angle θ is 0 degree, that is, when the valve body 25 moves in parallel with the dotted line X which is the center line of the fluid passage 9, the valve body 25 may not move well. Therefore, in the present embodiment, the predetermined angle θ
Is provided.

As shown in FIG. 2, the swing rod 1
The valve body 25 is connected to the cylindrical portion 15b of No. 5.
The valve body 25 is a single member, and includes a disc portion 27, two arm portions 29 extending from the disc portion 27, and each arm portion 2
It comprises a boss portion 31 provided at the end of 9 and a stopper portion 33 protruding from the rear surface of the disc portion 27. A resin lining 51 is also applied to the surfaces of the disk portion 27, the arm portion 29, the boss portion 31, and the stopper portion 33. The stopper portion 33 is covered with a rubber stopper 35. The stopper portion 33 is a protrusion made of several cylindrical portions having circular cross sections with different diameters. In particular, since the diameter of the tip portion is large, the rubber stopper 35 covered by the stopper portion 33 is prevented from easily coming off due to the unevenness due to the difference in diameter of the stopper portion 33. The rubber stopper 35 can come into contact with the stopper receiving seat 37 shown in FIG. 1 formed at a predetermined portion of the fluid passage 9 when the valve body 25 moves. The reason why the rubber stopper 35 is provided is that if the stopper portion 33 and the stopper receiving seat 37 come into direct contact with each other, the resin linings provided on the surfaces thereof may be damaged.
This is to prevent it. Boss portion 31 of the valve body 25
Is loosely fitted in the columnar portion 15b of the swing rod 15. Therefore, the valve body 25 swings within the range from the fully closed position where the disc portion 27 engages the valve seat 11 of the valve box 7 to the fully open position where the rubber stopper 35 contacts the stopper receiving seat 37. Can be rotated about the rotation center. A washer 39 is arranged between each boss portion 31 and each bush 17 adjacent to the boss portion 31.

Next, the operation of the swing check valve 5 having the above structure will be described. When the valve body 25 is in the fully closed position in FIG. 1, when the fluid flows into the fluid passage 9 of the valve box 7 from the inlet 9a, the fluid pressure acts on the front surface of the disc portion 27 of the valve body 25. Due to this fluid pressure, the valve body 25
Starts rotating counterclockwise as viewed in FIG. When the disc portion 27 is separated from the valve seat 11 by the rotation of the valve body 25, the fluid flows toward the outlet 9b. The valve body 25 rotates to the fully open position where the rubber stopper 35 contacts the stopper receiving seat 37 by the pressure of the flowing fluid.

When the fluid pressure on the inlet 9a side becomes lower than the fluid pressure on the outlet 9b side, the fluid tends to flow backward in the fluid passage 9. On the other hand, in this case, the pressure acting on the front surface of the valve body 25 is reduced, and the pressure acting on the rear surface of the valve body 25 is relatively increased. Therefore, the valve body 25
Starts to rotate clockwise as viewed in FIG. 1 due to its own weight or the pressure acting on the rear surface of the valve body 25. Finally, the disc portion 27 engages with the valve seat 11 to block the fluid passage 9 and prevent the reverse flow of fluid.

When the valve body 25 returns to the fully closed position, the valve body 25,
Depending on manufacturing tolerances of the swing rod 15, the valve seat 11, and the like, the disc portion 27 of the valve body 25 may be difficult to completely adhere to the valve seat 11. However, in this embodiment, since the valve body 25 can be moved by the self-aligning function, the valve body 2 can be moved.
Due to the fluid pressure acting on the rear surface of the disc 5, the disc portion 27 automatically comes into close contact with the valve seat 11 even if there is some manufacturing tolerance.

[0016]

As described above, according to the swing check valve of the present invention as set forth in claim 1, the valve body is formed as one member from the main body portion, the arm portion and the boss portion, and at least the valve box. The valve body, the swing rod, and the fluid contact portion of the support member are subjected to a lining process, and the shaft hole for accommodating the swing rod allows the swing rod to move along the inner surface of the shaft hole. Thus, since it extends downward at a predetermined angle with respect to the central axis of the valve seat, while having the function of aligning the valve body with respect to the valve seat,
It becomes possible to perform lining processing on the fluid contact portion of the valve component member including almost the entire surface of the valve body, which has been impossible in the past. Therefore, when used in piping for corrosive fluids, the service life is greatly improved compared to the conventional one.

According to the swing check valve of the second aspect, since the stopper portion is provided on the back surface of the valve body and the stopper portion is covered with the rubber protecting member, the valve body moves to the fully open position. At this time, the stopper portion is prevented from damaging the lining process applied to the abutting portion of the valve box.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a swing check valve according to an embodiment of the present invention.

2 is a cross-sectional view of the swing check valve taken along line II-II in FIG.

3 is a sectional view of the bush and the swing rod taken along line III-III in FIG.

[Explanation of symbols]

7 ... Valve box, 9 ... Fluid passage, 11 ... Valve seat, 15 ... Swing rod, 15a ... Square column part (both ends), 17 ... Bush (supporting member), 17a ... Hole (axial hole), 25 ... Valve body, 27
... disk portion (main body portion), 29 ... arm portion, 31 ... boss portion, 33 ... stopper portion, 35 ... rubber stopper (protective member), 51 ... resin lining.

 ─────────────────────────────────────────────────── ─── Continued Front Page (72) Inventor Naotake Tsuboi, No. 14 Nakamachi, Moji-ku, Kitakyushu, Fukuoka Prefecture Okano Valve Manufacturing Co., Ltd. (72) Makoto Okumura No. 14 Nakamachi, Moji-ku, Kitakyushu, Fukuoka Okano Valve Manufacturing Co., Ltd. (72) Inventor Tokki Ikeda 1-14 Nakamachi, Moji-ku, Kitakyushu, Fukuoka Okano Valve Manufacturing Co., Ltd.

Claims (2)

[Claims] 1. A valve box having a valve seat, a valve body formed as one member from a main body portion, an arm portion and a boss portion, and a swing in which the boss portion is loosely supported to swingably support the valve body. A rod, and a support member having a shaft hole for accommodating both ends of the swing rod, and at least the valve box, the valve body, the swing rod and the fluid contact portion of the support member are subjected to a lining process, A swing check valve extending downward at a predetermined angle with respect to a central axis of the valve seat to allow the swing rod to move along an inner surface of the shaft hole. 2. The swing check valve according to claim 1, wherein a stopper portion is provided on the back surface of the valve body, and the stopper portion is covered with a rubber-made protection member.