JPH06346761A - Butterfly valve - Google Patents

Abstract

PURPOSE:To facilitate manufacturing of a valve body to reduce a cost and enhance airtightness. CONSTITUTION:When a valve body 2 is closed, an outer peripheral edge 2c of the valve body 2 abuts on a side surface of a swelled part 6 formed in an inner peripheral surface 1a of a pipe line 1 so as to block a clearance formed between the outer peripheral edge 2c of the valve body 2 and an inner contact surface 1b of the pipe line 1. Therefore, even when there is an error in dimensional accuracy in an outer peripheral surface 2d of the valve body 2, possibility of fluid leakage is eliminated and airtightness is enhanced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a butterfly valve used as, for example, an exhaust shutter of an automobile, and more particularly to a butterfly valve capable of increasing the degree of sealing when the valve body is closed.

[0002]

2. Description of the Related Art FIG. 3 is a partially cutaway perspective view showing an example of a conventional butterfly valve (A) used for the above-mentioned exhaust shutter and the like.

This butterfly valve (A) has an elliptical disc-shaped valve element (3) in an axial line of the conduit (1) in the conduit (1) for fluid flow.
Tip surfaces of two valve shafts (3) orthogonal to (L) facing each other
The valve body (2) is rotatably supported by being fitted into the groove (4) provided in (3a), and the valve body (2) is rotated by operating the handle lever (5) connected to the valve shaft (3). Moving the pipeline
It is designed to open and close (1).

In the butterfly valve (A) used for such an exhaust shutter, the airtightness between the valve body (2) and the inner surface of the conduit (1) when the valve body (2) is in the closed position is ensured. It is desirable to increase it, and if the airtightness is poor, a large braking force cannot be obtained when the exhaust brake operates.

Therefore, conventionally, after the valve body (2) is formed by pressing or casting, the inner peripheral surface (1) of the conduit (1) of the valve body (2) is formed.
The entire outer peripheral surface (2d) in contact with a) is accurately machined into a curved surface by machining to enhance the airtightness with the inner peripheral surface of the conduit (1).

[0006]

DISCLOSURE OF THE INVENTION As described above, the valve body
When the outer peripheral surface (2d) of (2) is machined, the manufacturing process of the valve body (2) increases, the manufacturing cost rises, and the entire butterfly valve becomes expensive.

The present invention has been made in order to solve the above-mentioned problems, and it is not necessary to machine the valve body, and the valve body can be easily manufactured and the airtightness is improved when the valve body is closed. It is intended to provide.

[0008]

In order to achieve the above-mentioned object, according to the present invention, a valve body having a substantially elliptical shape, which is housed in a conduit having a circular section for fluid flow, is orthogonal to the axis of the conduit. A butterfly valve, which is rotatably supported by a valve shaft, is configured to rotate between a position for opening a pipe and a closed position inclined by a required angle with respect to the axis of the pipe, in a closed position of a valve element, At least one of the outer peripheral edge of the surface of the extending portion of the valve body extending in the opposite direction from the valve shaft on the side closer to the inner surface of the conduit first and the inscribed surface of the conduit facing it. , Characterized by forming a ridge,
This is intended to solve the above problems.

[0009]

When the valve body is closed, the ridge formed on either the valve body or the inner peripheral surface of the conduit closes the gap formed between the inner surface of the conduit and the inner surface of the conduit. Even if there is an error in the dimensional accuracy of the outer peripheral surface, there is no risk of fluid leakage,
Airtightness increases.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, an embodiment of the present invention will be described with reference to FIGS. The same members as those described in the conventional example are designated by the same reference numerals, and detailed description thereof will be omitted.

According to the present invention, when the valve body (2) is rotated to the closed position as shown by the solid line in FIG. 1, the extension of the valve body (2) extending from the valve shaft (3) in the opposite directions to each other. The inner peripheral surface (1b) of the conduit (1) facing the inner peripheral surface (1a) of the conduit (1) at the outlet (2a) and the outer peripheral edge (2c) of each surface (2b) facing the inner peripheral surface (1a) first ) Side, the outer peripheral edge (2
A semi-circular ridge (6) is formed along c).

The valve body (2) generally has an inner peripheral surface (1
It has an oval shape that can contact with a) at a required angle, and its outer peripheral surface (2d) is formed at a right angle to both surfaces (2b) of the valve body (2). When assembling, a gap for thermal expansion is provided between the outer peripheral surface (2d) and the inner peripheral surface (1a) of the conduit (1).

The raised portion (6) is formed by spraying ceramic powder such as alumina or heat-resistant alloy powder using known plasma or acetylene gas. That is, with the valve body (2) assembled to the conduit (1) and the valve body (2) being rotated to the closed position, the conduit (1) facing the outer peripheral edge (2c) of the valve body (2). ) Of the inner surface (1b) of the pipe (1), or before assembling the valve body (2), the inner surface (1b) of the pipe (1) is sprayed in advance. However, the ridge (6) can be formed. When spraying the valve body (2) assembled, it is preferable to mask the outer peripheral edge (2c) of the valve body (2). Prevents sticking to the road (1).

When the raised portion (6) as described above is formed, the outer peripheral edge (2c) of the valve body (2) is closed when the valve body (2) is closed.
Since the gap formed by contacting the side surface of the pipe (1) and the inscribed surface (1b) of the pipe (1) is closed, the airtightness is significantly enhanced.

Therefore, when the valve body (2) is used in the state of being stamped and formed by press working, a slight error occurs in the dimensional accuracy of the outer peripheral surface (2d) of the valve body (2) and the inscribed surface of the pipe line (1). Even if a gap is formed between (1b), the flow path can be almost completely blocked.

As a result, it is possible to eliminate the conventional machining process, which simplifies the production of the valve body (2) and contributes to the reduction of the manufacturing cost of the valve body (2) and the butterfly valve. can do.

When the raised portion (6) is provided on the inner surface of the conduit (1) as in the above embodiment, the valve body (2) is closed when the valve is closed.
The surface (2b) of the valve is in close contact with the ridge (6), and at that time, a slight gap is formed between the outer peripheral surface (2d) of the valve body (2) and the inner surface of the conduit (1). Therefore, there is an advantage that the thermal expansion of the valve body (2) can be released.

However, in a butterfly valve for controlling a fluid at room temperature that does not need to take thermal expansion into consideration, the raised portion (6) is provided on the outer peripheral edge of the surface (2b) on the valve body (2) side. It may be provided, or may be provided both in the valve body (2) and the conduit (1).

[0019]

According to the present invention, the ridge formed on either the valve body or the inner peripheral surface of the conduit closes the gap formed when the valve body is closed. Since it is not necessary to improve the dimensional accuracy of the outer peripheral surface of the valve body by machining, the valve body can be easily molded by pressing etc., and the valve body can be easily manufactured accordingly, so the entire valve body and butterfly valve can be manufactured. It can contribute to the reduction of cost.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view of a butterfly valve showing an embodiment of the present invention.

FIG. 2 is an enlarged cross-sectional view of portion B in FIG.

FIG. 3 is a partially cutaway perspective view showing a conventional butterfly valve.

4 is a vertical sectional side view taken along line IV-IV in FIG.

[Explanation of symbols]

(1) Pipe (1a) Inner surface (1b) Inner surface (2) Valve body (2a) Extension (2b) Surface (2c) Outer peripheral edge (2d) Outer surface (3) Valve shaft (3a) Tip surface (4) Recessed groove (5) Handle lever (6) Raised part (A) Butterfly valve

Claims (2)

[Claims] 1. A position at which a valve body having a substantially oval shape housed in a conduit having a circular cross section for fluid flow is rotatably supported by a valve shaft orthogonal to an axis of the conduit and the conduit is opened, In a butterfly valve adapted to rotate between a closed position inclined by a required angle with respect to the axis of the pipe, in a closed position of the valve body, in an extension portion of the valve body extending in mutually opposite directions from the valve shaft. A butterfly valve, wherein a raised portion is provided on at least one of an outer peripheral edge of a surface that is closer to an inner surface of the conduit and an inner contact surface of the conduit that faces the inner peripheral surface of the conduit. 2. The butterfly valve according to claim 1, wherein the raised portion is formed by thermal spraying.