JPH0651639U - Butterfly valve seat ring - Google Patents

Abstract

(57) [Abstract] [Purpose] The present invention aims to reduce the torque for driving the valve element and improve the sealing performance. . A seat ring includes a valve body having a cylindrical fluid passage, a disc-shaped valve body rotatably supported in the valve body, and a seat ring interposed between the two. In a butterfly valve having a middle height portion that extends continuously in the circumferential direction on the inner peripheral surface, a concave groove that extends continuously in the circumferential direction is provided in the center of the middle height portion, and two grooves are provided on both sides of the depression groove. Is produced, and the outer peripheral surface of the valve body is brought into contact with the tops of the two threads when the valve is closed.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a seat ring of a butterfly valve, and more particularly to a new improvement of the seat ring that can improve the valve body driving torque and the seal performance.

[0002]

[Prior art]

 Conventionally, a disc-shaped valve body is rotatably supported in a hollow cylindrical valve body made of a rigid material, and a seat ring made of a soft elastic material such as rubber is placed between the valve body and the valve body. However, a butterfly valve is known in which the flow passage is opened and closed by contact and separation between the outer peripheral edge of the valve body and the inner peripheral surface of the seat ring. No. 20576, Japanese Utility Model Publication No. 3-62270 and the like.

Generally, as shown in FIG. 5, a seat ring (1) of a butterfly valve has a circular arc-shaped projection, which is referred to as a mid-high portion (2), which projects inward at the center of the inner peripheral surface. The valve body (3) is continuously formed in the direction, and the outer peripheral edge of the valve body (3) abuts against the middle height portion (2) and presses into the middle height portion (2) to open and close the valve.

By the way, in the butterfly valve in which the passage is opened and closed by the contact and separation of the seat ring (1) having the middle-high portion (2) and the valve body (3). When the valve is closed near full closure, it crushes the mid-high portion (2) at the outer peripheral edge of the valve body and bites into it, and the repulsive force generated from the seat ring greatly affects the torque value for driving the valve body. It is considered that the valve body is affected by this repulsive force in the conventional butterfly valve, so a large torque was required.

[0005]

[Problems to be solved by the device]

 This invention is intended to reduce the torque for driving the valve element and improve the sealing performance.

[0006]

[Means for Solving the Problems]

 In order to solve the above problems, the means adopted by the present invention is a valve body having a cylindrical fluid passage, a disc-shaped valve body rotatably supported in the valve body, and both. In a butterfly valve consisting of a seat ring interposed between the seat ring and the seat ring inner peripheral surface, which has a middle-high portion that extends continuously in the circumferential direction, a concave groove that extends continuously in the circumferential direction in the center of the middle height portion. Is formed to form two tops on both sides of the groove, and the outer peripheral surface of the valve body is brought into contact with the tops of the two when the valve is closed.

[0007]

[Work]

 In the process of closing the valve body, a repulsive force is generated by the contact between the first apex of the middle height portion in FIG. 3 and the outer peripheral surface of the valve body, but in the middle height portion where the outer peripheral edge of the conventional valve body bites. Since the volume at the first apex of this device is smaller than the volume of the seat ring, the repulsive force also becomes smaller, and after the apex of the valve body passes, the repulsive force acts in the direction to reduce the torque. The torque for driving the valve disc is significantly reduced. Further, in this invention, since the valve body comes into contact with the two vertices of the middle height portion and two seal points are present, the sealing performance is also improved.

[0008]

[Effect of device]

 According to this invention, it is possible to reduce the torque for driving the valve element and improve the sealing performance.

[0009]

【Example】

 Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings. In the figure, (10) is a valve body having a cylindrical fluid passage (11) penetrating through the center, and an annular seat ring (12) made of a soft elastic material such as rubber on the inner peripheral surface. Is fixed and mounted on the valve body (10). A disk-shaped valve body (13) is rotatably supported by a valve rod (14) in the valve body (10), and is supported by the outer peripheral edge of the valve body (13) and the inner peripheral surface of the seat ring (12). The fluid passage (11) is opened and closed by contacting and separating.

On the inner peripheral surface of the seat ring (12), a protrusion (15) having an arcuate cross section is formed so as to protrude inward. The protrusion (15) is usually called a middle height portion, and extends continuously in a strip shape in the circumferential direction of the seat ring (12). The structure of the seat ring (12) having the middle height portion (15) is conventionally known, and the outer peripheral edge of the valve body (13) is pressed against the middle height portion (15) to crush the rubber and close the flow passage. It

According to the invention, in a seat ring (12) having such a middle height portion (15), the center of the middle height portion (15) is provided in a groove shape along the circumferential direction, and the groove (16) is formed. It is characterized in that two tops (17) (18) are formed on both sides of the. The concave groove (16) is not limited to the circular arc cross section as shown, but may be a rectangular cross section. The outer peripheral edge of the valve body (13) is wide so that the outer peripheral edge of the valve body (13) straddles the groove (16) and abuts the tops (17) (18) of the two threads when the valve is closed. Form on the circular arc surface (19). The structure of the valve body (13) is preferably, for example, the one disclosed in Japanese Utility Model Laid-Open No. 63-62270, but is not limited to this.

The middle height portion (15), the concave groove (16), and the top portions (17) and (18) are not formed on the boss contact surface (20) with which the boss portion of the valve body (13) contacts.

As shown in FIGS. 2 to 3, in the process of closing the valve body (13), the first apex (17) of the middle height portion (15) and the valve body outer peripheral surface (19) in FIG. Although a repulsive force is generated by the contact, the volume of the seat ring at the first apex of the present invention is smaller than the volume of the seat ring in the middle height portion where the outer peripheral edge of the conventional valve body bites, so the repulsive force also becomes smaller and the valve After the apex of the body passes, the repulsive force acts in the direction of reducing the torque, so the torque for driving the valve body is significantly reduced. Further, in this invention, the valve element comes into contact with the two vertices (17) and (18) of the middle height portion, and there are two sealing points, so that the sealing performance is also improved.

[Brief description of drawings]

FIG. 1 is a partial perspective view of a seat ring.

FIG. 2 is a sectional view showing a valve closing process.

FIG. 3 is a sectional view showing a valve closing process.

FIG. 4 is a sectional view showing a valve closing process.

FIG. 5 is a sectional view showing a closing process of a conventional butterfly valve.

[Explanation of symbols]

 (10) Valve body (11) Fluid passage (12) Seat ring (13) Valve body (14) Valve stem (15) Middle height (16) Recessed groove (17) Top (18) Top (19) Arc surface

Claims (1)

[Scope of utility model registration request] 1. A valve main body having a cylindrical fluid passage, a disc-shaped valve body rotatably supported in the valve main body, and a seat ring interposed therebetween. In a butterfly valve having a mid-height portion continuously extending in the circumferential direction on the inner circumferential surface of a seat ring, a concave groove continuously extending in the circumferential direction is provided at the center of the mid-height portion, and both sides of the concave groove are provided. A seat ring for a butterfly valve, characterized in that a top portion of two lines is formed and a top surface of the two lines is brought into contact with an outer peripheral surface of the valve body when the valve is closed.