JPH0564576U - Butterfly valve disc - Google Patents

Abstract

(57) [Summary] [Purpose] This invention is designed so that when an excessive pressure is generated in the circuit and the pressure is applied to the valve element, a part of the valve element is deformed and the excessive pressure is released to the secondary side. It is intended to provide the valve body so obtained. [Structure] At least the peripheral portion is formed of an elastic material, and the peripheral portion is more easily elastically deformed than the central portion.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a valve element of a butterfly valve, which is designed to allow an excessive pressure to escape when an excessive pressure is generated in a fluid circuit including the butterfly valve.

[0002]

[Prior Art]

 Conventionally, an elastic sealing material called a seat ring is mounted on the inner peripheral surface of a valve body penetrating a cylindrical fluid passage, and the outer periphery of a disc-shaped valve body rotatably supported in the seat ring. A butterfly valve whose surface is brought into contact with and separated from an inner peripheral surface of a seat ring to open and close the fluid passage is known and used for controlling various fluids.

By the way, in the fluid circuit in which the butterfly valve is incorporated, sudden pressure fluctuations such as a water hammer may occur. Such rapid pressure fluctuations may damage circuit components such as valves, pipes, and pumps, and in the worst case, cause external leakage of fluid. Therefore, in the past, measures were taken to minimize the damage by arranging a pressure relief device equipped with a rupture plate in the appropriate place in the circuit to escape the fluctuating pressure.

However, in the conventional butterfly valve, the valve body is usually formed of a rigid body such as metal or hard synthetic resin, and when the valve is closed, the above-mentioned pressure fluctuation occurs in the circuit and the butterfly valve is excessively large. Even if pressure was applied, it was impossible to let that pressure escape to the secondary side.

[0005]

[Problems to be solved by the device]

 This invention does not provide a valve body that allows a part of the valve body to deform when the excessive pressure is generated in the circuit and the pressure is applied to the valve body so that the excessive pressure escapes to the secondary side. And

[0006]

[Means for Solving the Problems]

 In order to solve the above problems, the means adopted by the present invention is characterized in that at least the peripheral portion is formed of an elastic material, and the peripheral portion is elastically deformed more easily than the central portion.

[0007]

[Work]

 Since the peripheral portion of the valve body is formed with elastic force so as to be easily deformed, when the excessive pressure is applied, the peripheral portion is deformed and the pressure can be released to the secondary side. Further, when the valve is closed, when the seat ring is pressed, the peripheral portion is deformed, so that the driving torque of the valve body can be reduced.

[0008]

[Effect of the device]

 According to this invention, when pressure fluctuations such as a water hammer occur in the fluid circuit incorporating the butterfly valve and an excessive pressure is applied to the valve body, the peripheral part deforms and the excessive pressure is released to the secondary side. Since it can be released, the butterfly valve can have a pressure buffering function for the fluid circuit. Further, when the valve body is rotated to open or close the valve, the peripheral portion that comes into pressure contact with the inner peripheral surface of the seat ring is deformed, so that the drive torque of the valve body can be reduced.

[0009]

【Example】

 Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings. In the figure, (1) is a valve body of a butterfly valve, which is formed into a disc shape as a whole, and is formed with a valve shaft hole (2) through which a valve rod is inserted at its center. The valve shaft hole (2) does not necessarily have to be formed penetrating as shown in the drawing, but blind valve shaft holes may be formed in the upper and lower parts in the diametrical direction, and the valve rod may be inserted from above and below. Of course.

According to this invention, the valve body (1) of the butterfly valve is made of an elastic material such as rubber or synthetic resin, and the peripheral portion (3) of the valve body (1) is more easily deformed than the central portion (4). Then, when an excessive pressure is applied, the peripheral portion (3) is deformed to create a gap with the seat ring so that the excessive pressure escapes to the secondary side. In this specification, the term “secondary side” is a term based on the source of excessive pressure. The side of excessive pressure generated from the valve body is the primary side, and the opposite side is the secondary side.

1 and 2 show an example of a structure in which the peripheral portion (3) of the valve body (1) is more easily deformed than the central portion (4). In FIGS. 1 and 2, the valve body (1) is formed of an elastic material, forms an arcuate rib (5) along the inner end of the peripheral portion (3), and is orthogonal to the valve shaft hole (2). A linear rib (6) is formed in the direction. The arcuate ribs (5) and the linear ribs (6) increase the rigidity of the central portion of the valve body (1), and the peripheral portion (3) is more easily deformed than the central portion (4). When the valve shaft hole (2) is formed blindly in the upper and lower portions of the valve body, a rib extending in the valve shaft direction orthogonal to the linear rib (6) is formed.

As a result, as shown in FIG. 3, when the valve body (1) is overpressured (6), the peripheral portion (3) is deformed toward the secondary side, and the seat ring (8) is A gap (9) is created between the two, allowing the overpressure (6) to escape to the secondary side. After the pressure escape, the peripheral part (3) is restored by its elasticity, so that the circuit can be immediately returned to the original state. Further, as shown in FIG. 4, when the valve body (1) is rotated in the valve closing direction, the peripheral portion (3) of the valve body (1) which is pressed against the inner peripheral surface of the seat ring (8) is Since it deforms due to its elasticity, it is possible to reduce the drive torque of the valve body. When the valve is closed, the peripheral portion (3) comes into pressure contact with the inner peripheral surface of the seat ring due to its elastic restoring force, so there is no risk of leakage.

5 and 6 show a modification of the present invention, in which the central portion (4) of the valve body (1) made of an elastic material such as rubber is made thicker than the peripheral portion (3), The peripheral part (3) is more easily deformed than the central part (4).

Note that a metal plate, a hard synthetic resin plate, or the like may be integrally embedded in the central portion to harden the central portion to facilitate deformation of the peripheral portion.

In any of the above cases, the length of the peripheral portion is appropriately set, and the peripheral portion has a hardness that is easily deformed by the normal pressure applied to the valve body. Of course.

[Brief description of drawings]

 Fig. 1 Front view of valve body according to the present invention Fig. 2 Fig. 1 II-II line sectional view Fig. 3 Operation diagram when excessive pressure is applied Fig. 4 Operation diagram when valve is closed Fig. 5 Front view of a modification 6 Fig. 5 IV-IV Line cross section

[Explanation of symbols]

 (1) Valve body (2) Valve shaft hole (3) Peripheral part (4) Center part (5) Arc-shaped rib (6) Linear rib (7) Overpressure (8) Seat ring (9) Gap

Claims (3)

[Scope of utility model registration request] 1. At least a peripheral portion is formed of an elastic material,
A valve element of a butterfly valve, characterized in that the peripheral portion is elastically deformed more easily than the central portion. 2. A disc-shaped valve body is made of an elastic material, arc-shaped ribs are provided along the inner end of the peripheral portion, and linear ribs are provided in a direction orthogonal to the valve shaft hole. The valve body according to claim 1, wherein the peripheral portion is elastically deformed more easily than the central portion. 3. The disk-shaped valve body is made of an elastic material, the central portion is made thicker than the peripheral portion, and the peripheral portion is elastically deformed more easily than the central portion. ) Described valve body.