JP3188383B2 - Butterfly valve with elastic valve seat - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a butterfly valve with an elastic valve seat. More specifically, an elastic annular valve seat such as a rubber sheet is attached to the inner peripheral portion of a cylindrical flow passage in a valve box, and the rotary valve is rotated in the flow passage. The present invention relates to a butterfly valve with an elastic valve seat configured to open and close a flow path by the rotational motion of a freely provided circular valve body.

[0002]

2. Description of the Related Art FIGS. 4 and 5 are a vertical sectional side view and a semi-cross sectional plan view of a general butterfly valve having such a resilient valve seat, in which 1 has a cylindrical flow path 1A. In a valve box, valve rods 2A and 2B which are divided into upper and lower portions are respectively provided at upper and lower positions radially opposed to each other at a substantially central portion in the axial direction of the flow path 1A in the valve box 1, and the axis of the flow path 1A of the valve box 1 is provided. b, and is rotatably supported about an axis a passing through the center of the flow path 1A. The upper end of the upper valve stem 2A is supported by a key 3 via a key 3. A coupling 4 that can be coupled to an external rotary operation mechanism is connected.

[0005] Reference numeral 5 denotes a circular valve element disposed in the flow path 1A. Two upper and lower portions of the circular valve element which face each other in the radial direction are fixedly connected to the valve rods 2A and 2B via coupling pins 6, With the rotation of the valve stems 2A and 2B, the inside of the flow path 1A is rotated to open and close the flow path 1A. A valve seat 5A formed into a circular shape is fitted on the outer peripheral surface of the valve element 5. Reference numeral 8 denotes an elastic annular valve seat made of a rubber sheet or the like, which is formed in a substantially Ω-shaped cross section as shown in FIGS. 6 and 7, and whose both projecting legs 8a, 8a are connected to the flow passage 1A in the valve box 1. In a state in which it is elastically engaged in an annular concave portion 7 having a substantially T-shaped cross section formed in the inner peripheral portion of the valve case, the inlet of the valve box and the elastic annular valve seat are provided at a plurality of locations of the valve box. Injecting and filling a curable resin into the annular gap between the inner surface 8b and the flow path 1
A is attached to the valve box 1 side so as to protrude to A,
When the valve element 5 is rotated to the fully closed position, the valve seat 5A on the outer periphery cuts into the inner surface 8b of the elastic annular valve seat 8 to stop water.

Meanwhile, in the butterfly valve with the elastic valve seat having the above-described configuration, conventionally, the inner surface 8b of the elastic annular valve seat 8 extends over the entire circumference as shown in FIG. , Formed on a conical surface inclined with respect to the axis b of the flow path 1A.

[0005]

In the butterfly valve with the elastic valve seat having the above-described structure, the valve body 5 is rotated through the valve rods 2A and 2B to be fitted on the outer peripheral surface thereof. 6 and 7, as shown in FIGS. 6 and 7, by elastically biting the inner peripheral surface 8b of the elastic annular valve seat 8 attached to the valve box 1 side, the flow path 1A is closed and the water is stopped. However, if water leakage occurs in this state, the valve body 5 is closed and rotated around the axis a as shown by an arrow x in FIG. 7 in order to further improve the water stopping performance. In the valve seat 5A on the valve body 5 side, one of the two side portions (portion A in FIG. 6) opposed in the radial direction perpendicular to the rotation axis a is an elastic annular valve seat on the valve box 1 side. 8, but the other side portion (portion B in FIG. 6) has the elastic annular valve seat 8 on its side. As such become freely escape against the conical inner surface 8b, gradually lowered water stopping ability, when the closing rotating above a certain level, there is a problem that waterproofing becomes impossible.

As a structure for solving such a problem, as shown in FIG. 8, metal sheets 9A and 9B whose radially opposite portions are inclined in opposite directions are attached to the valve box 1 side. Saw-like retaining portion 10
The rubber sheets 10A and 10B having a and 10b are fitted to each other, and these rubber sheets 10A and 10B are
A and 9B are elastically brought into contact with each other to stop the water, and the rubber sheets 10 are closed by the closing rotation in the arrow x direction.
A butterfly valve configured so that the A and 10B bite into the rubber sheets 10A and 10B together to improve the water stopping performance is considered, but in this case, the manufacturing process of the metal sheets 9A and 9B is considered. Not only does it require a great deal of labor, but also requires a high degree of manufacturing accuracy, resulting in a significant increase in the cost of the entire valve.

Accordingly, the present invention has been made in view of the above-mentioned circumstances, and it is easy to manufacture a valve seat on a valve box side to suppress an increase in cost. It is an object of the present invention to provide a butterfly valve with an elastic valve seat that can achieve an improvement in the water stopping performance at the time and can reduce the rotational opening and closing torque at the normal time.

[0008]

In order to solve the above-mentioned problems, a butterfly valve with an elastic valve seat according to the present invention is provided with a valve box having a cylindrical flow path and an axial line of the flow path of the valve box. With respect to the valve rod held in the valve box in a state that is rotatable around an axis passing through the center of the flow path and perpendicular to the flow path, the inside of the flow path rotates with the rotation of the valve rod. A circular valve element that opens and closes the flow path, a circular valve seat mounted on the outer peripheral part of the valve element, and an inner peripheral part of the flow path of the valve box,
When the valve body is rotated to the fully closed position, in a butterfly valve provided with an elastic annular valve seat that cuts off water by cutting off a valve seat at an outer peripheral portion thereof, the elastic annular valve seat attached to the valve box side includes: Molded rubber sheet, inner surface
The overall shape of the cylinder is circular at the cutting plane perpendicular to the pipe axis, and is perpendicular to the axis of rotation of the valve body.
The inner surfaces on both sides facing each other on the cut surface including the
When the valve body further rotates from a fully closed position where the circular valve seat of the valve body and the elastic annular valve seat of the valve box contact each other, the circular valve has a different inclination angle with respect to the tangent line of the body rotation locus circle. It is characterized in that the seat has a pseudo-cone shape in which the bite amount of the seat increases.

[0009]

Here, usually, the circular valve seat having the valve body fitted on the outer peripheral surface thereof is rotated to the fully closed position so that the circular valve seat is elastically contacted with the inner surface of the elastic annular valve seat on the valve box side. If water leaks in that state, the valve body is further closed and rotated, so that both side portions opposed in the radial direction perpendicular to the rotation axis of the circular valve seat on the valve body side Will work together with the inner surface of the elastic annular valve seat, so that the water stopping performance is improved and water leakage can be reliably prevented.

Here, the elastic annular valve seat on the valve box side is formed on the valve box side such that the bottom of the cone forming a part of the circular surface is perpendicular to the axis of the flow path of the valve box. It is attached.

[0012]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is an enlarged cross-sectional plan view of a main part of a butterfly valve with an elastic valve seat according to the present invention, and FIG. 2 is an enlarged view of a part A and a part B of FIG. In these drawings, the same components as those of the conventional example shown in FIGS. 6 and 7 are denoted by the same reference numerals, and detailed description thereof will be omitted. Note that the overall configuration of the butterfly valve is as shown in FIGS. 4 and 5, and a description of the overall configuration will be omitted.

In FIG. 1, both side projecting legs 8a, 8a are elastically engaged in an annular concave portion 7 having a substantially T-shaped cross section formed in the inner peripheral portion of the flow path 1A in the valve box 1. The elastic annular valve seat 8 attached to the valve box 1 is configured as follows. That is, the elastic annular valve seat 8 has an inner surface 8b1 of one side (A portion) of the both sides opposed in the radial direction perpendicular to the rotation axis of the valve body 5 in the valve body rotation locus circle. It has an inclination angle of α with respect to the tangent t1, and the other side (B
Pseudo-conical shape in which the inner surface 8b2 of the portion has an inclination angle of β with respect to the tangent t2 of the valve body rotation trajectory circle, and the bite amount in the elastic annular valve seat 8 increases as the valve body 5 is tightened. And their inner surfaces 8b1 and 8b2
Are continuously and integrally molded so that the entire inner surface formed by continuously connecting them has a circular shape as shown in FIG.

In the butterfly valve provided with the elastic annular valve seat 8 having the above-described shape, the diameter of the valve seat 5A in which the valve body 5 is fitted to the outer peripheral surface thereof through the valve rods 2A and 2B is usually used. As shown in FIGS. 1 and 2, both sides opposing each other in the direction are rotated to the fully closed position so as to elastically contact the inner surfaces 8b1 and 8b2 of the elastic annular valve seat 8 on the valve box 1 side. Closes the flow path 1A and stops water. In this normal state, the amount of bite of the valve seat 5A on the valve element 5 side with respect to the inner surfaces 8b1 and 8b2 of the elastic annular valve seat 8 can be small, so that the rotational opening / closing torque of the valve element 5 becomes small and light. The valve can be opened and closed.

If water leakage occurs even in the above-mentioned water-stop state, the valve body 5 is further closed and rotated about the axis a in the direction of arrow x in FIG. Both side portions (portions A and B in FIG. 2) of the circular valve seat 5A that face each other in the radial direction perpendicular to the rotation axis a are bite into the inner surfaces 8b1 and 8b2 of the elastic annular valve seat 8 together. , The bite amount gradually increases, and the water stopping performance is improved, so that it is possible to reliably prevent water leakage.

Here, the elastic annular valve seat 8 can be manufactured by molding a mold so that the entire inner surface thereof is circular in a cut surface perpendicular to the pipe axis.
It is possible to make the fabrication of the valve seat on the side very easy and efficient and to greatly reduce the cost of the butterfly valve as a whole.

[0017]

As described above, according to the present invention, in a normal state, the valve seat on the valve body side is brought into elastic contact with the inner surface of the elastic annular valve seat on the valve box side. Since the amount of biting of the valve seat into the elastic annular valve seat can be small, the rotation opening / closing torque of the valve body can be reduced, and the valve opening / closing operation can be performed lightly. In addition, if water leakage occurs in that state, the valve body is further closed and rotated so that both sides facing in the radial direction perpendicular to the rotation axis of the valve body-side valve seat are inside the elastic annular valve seat. It is possible to work on both surfaces without permission, and it is possible to easily improve the water stopping performance and reliably prevent water leakage. In addition, the elastic annular valve seat can be molded so that the entire inner surface thereof is circular in a cross section perpendicular to the pipe axis, and the valve case side compared to processing a metal sheet. The effect is achieved that the manufacturing process of the valve seat can be made very easy and efficient, and the cost of the entire butterfly valve can be greatly reduced.

[Brief description of the drawings]

FIG. 1 is an enlarged cross-sectional plan view of a main part of a butterfly valve with an elastic valve seat according to the present invention.

FIG. 2 is an enlarged view of a portion A and a portion B of FIG. 1 for explaining an operation state of the butterfly valve with the elastic valve seat.

FIG. 3 is a longitudinal sectional view of the entire elastic valve seat.

FIG. 4 is a vertical sectional side view of a general butterfly valve with an elastic valve seat.

FIG. 5 is a half-cross-sectional plan view of the butterfly valve with the elastic valve seat according to the first embodiment.

FIG. 6 is an enlarged cross-sectional plan view of a main part of a conventional butterfly valve with an elastic valve seat.

FIG. 7 is an enlarged view of a portion A and a portion B of FIG. 6 for explaining an operation state of the butterfly valve with the elastic valve seat.

FIG. 8 is a schematic plan view of a main part of another conventional butterfly valve using a metal sheet.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Valve box 1A Flow path 2A, 2B Valve stem 5 Valve body 5A Circular valve seat 8 Elastic annular valve seat 8b1, 8b2 Inner surface a Rotation axis b Flow path axis

Continuation of the front page (56) References JP-A-62-83563 (JP, A) JP-A-53-60721 (JP, A) JP-A-63-235773 (JP, A) JP-A-53-60722 (JP, A) , A) Japanese Utility Model Showa 60-188271 (JP, U) Japanese Utility Model Showa 58-138865 (JP, U) Japanese Utility Model Showa 56-25871 (JP, U) Japanese Utility Model Sho 51-23383 (JP, Y2) Japanese Utility Model Sho 46-13916 (JP, Y1) Jiko 59-27573 (JP, Y2) (58) Fields investigated (Int. Cl. ⁷ , DB name) F16K 1/16-1/226

Claims (1)

(57) [Claims] 1. A valve box having a cylindrical flow path, wherein the valve box is rotatable about an axis perpendicular to the axis of the flow path of the valve box and passing through the center of the flow path. A valve stem held by the valve box, a circular valve body that rotates in the flow path with the rotation of the valve stem to open and close the flow path, and a circular valve attached to an outer peripheral portion of the valve body. A valve seat and an elastic annular valve seat that is attached to the inner peripheral portion of the flow path of the valve box, and when the valve body is rotated to the fully closed position, the valve seat on the outer peripheral portion bites and stops water. In the butterfly valve provided, the elastic annular valve seat attached to the valve box side is formed by molding.
Made of rubber sheet,
With a circular shape in a cutting plane perpendicular to the tube axis, the valve
Perpendicular to the axis of rotation of the body and
The inner surface on the opposite side is the tangent to the valve body rotation locus circle.
When the valve body further rotates from the fully closed position where the circular valve seat of the valve body and the elastic annular valve seat of the valve box are in contact with each other, the bite of the circular valve seat in the elastic annular valve seat increases. A butterfly valve with an elastic valve seat characterized by having a pseudo-conical shape.