JPH0222534Y2 - - Google Patents

Description

[Detailed description of the invention] [Field of industrial application] The invention provides a hard rubber lining for the valve body and a soft rubber lining for the inner peripheral surface of the valve body.
Compared to applying a hard rubber lining to both the valve body and the valve body, it is possible to reduce the increase in valve operation torque caused by contact friction between the rubber linings at the seat part, and to provide a soft rubber lining to the valve body and a valve body. This invention relates to a butterfly valve that is corrosion resistant while improving manufacturability by making it easier to process the rubber lining on the valve box side seat part rather than applying a hard rubber lining to the box.

[Conventional technology]

Conventionally, in butterfly valves that have a rubber sheet on the seat between the valve body and the valve box, in order to avoid an increase in valve operating torque due to contact friction with the rubber sheet, a It has been proposed to attach a film with lower friction than rubber (for example, see Japanese Patent Application Laid-Open No. 1983-69926).

[Problem that the invention attempts to solve]

However, the hard rubber lining on the valve body,
In addition, in a butterfly valve in which a soft rubber lining is provided on the inner circumferential surface of the valve box, in an attempt to more effectively reduce the increase in valve operating torque caused by contact friction between the rubber linings, the valve box is When a membrane with lower friction than the rubber lining is pasted on the surface of the soft rubber lining of the side seat, the attached membrane also deforms greatly due to the large elastic deformation of the soft rubber lining due to contact with the hard rubber lining on the valve box side. As a result, the membrane tends to peel off when the valve is repeatedly opened and closed, which poses a problem in terms of durability.

An object of the present invention is to achieve a reduction in valve operation torque while improving durability.

[Means for solving problems]

The characteristic structure of the butterfly valve according to the present invention is that a film body with lower friction than the hard rubber lining the valve body is placed on the annular seat portion of the valve body against the valve body which is lined with soft rubber, and a film body with a lower friction than the hard rubber lining the valve body is placed on the top of the outer peripheral edge of the valve body. The reason is that it is pasted in a chevron-shaped cross-section where
Its actions and effects are as follows.

[Effect]

In other words, by bringing a membrane body with lower friction than the hard rubber lining the valve body into contact with the soft rubber lining on the valve body side, the hard rubber lining on the valve body side and the soft rubber lining on the valve body side can be brought into direct contact. In comparison, the contact friction at the seat portion can be significantly reduced, thereby effectively reducing the valve operating torque.

In addition, a low-friction film is attached to the hard rubber lining on the valve body side, where the elastic deformation caused by the contact between the valve body side seat part and the valve body side seat part is much smaller than that of the valve body side soft rubber lining. Therefore, the hard rubber lining maintains the shape of the membrane, reducing the deformation of the membrane due to the contact between the sheet parts.
Furthermore, since the membrane body is attached to the annular seat portion of the valve body in a chevron-shaped cross-sectional shape with the top located on the outer peripheral edge side of the valve body, when the seat portions are brought into contact with each other, the edge of the membrane body is placed toward the valve box side. The surface of the membrane can be brought into smooth sliding contact with the valve box without any contact, and this effectively prevents the membrane from peeling off, greatly increasing the durability of the valve against repeated opening and closing. I was able to improve.

[Effect of idea]

As a result of the above, a butterfly valve that has rubber lining on both the valve body and the valve box is easy to open and close, and has excellent durability.

〔Example〕

Next, an embodiment of the present invention will be described based on FIGS. 1 to 3.

As shown in FIGS. 2 and 3, a valve stem 2 is rotatably supported in a cylindrical valve case 1, and a disc-shaped valve body 3 for opening and closing a flow path F in the valve case is attached to the valve stem 2. connect,
A soft rubber lining 4 is provided on the inner circumferential surface of the valve body 1, and a hard rubber lining 5 is provided on the outer surface of the valve body 3, and a seat action is achieved by press-contacting the peripheral edge of the valve body 3 with the annular seat portion 3A on the valve body side. The annular seat portion 1A on the valve box side is formed by thickly molding the soft rubber lining 4 on the valve box side located at the position where the annular seat portion 1A is disposed, thereby forming a so-called all-rubber lining type corrosion-resistant butterfly valve. There is.

As shown in FIG. 1, the valve body side annular seat portion 3A
A Teflon sheet 6 is placed on the outer surface of the hard rubber lining 5 in a state in which the Teflon sheet 6 is aligned with the pointed curved shape of the outer peripheral edge of the valve body in a cross-sectional view of the valve body (that is, the cross-sectional shape of the Teflon sheet 6 is aligned with the outer peripheral edge side of the valve body 3). The soft rubber lining 4 is coated with a Teflon sheet 6 which has lower friction than the hard rubber lining 5 on the valve body side. By contacting the seat surface of the valve box-side annular seat portion 1A consisting of It is structured as follows.

[Another example]

Next, another embodiment will be described.

Membrane body 6 attached to the annular sheet portion 3A on the valve body side
As long as the material has lower friction than the hard rubber lining the valve body 3, it can be made of various materials such as not only Teflon sheet but also plastic plating. etc,
Various forms can be adopted.

[Brief explanation of the drawing]

The drawings show an embodiment of the butterfly valve according to the present invention, and FIG. 1 is an enlarged sectional view of the seat part, FIG. 2 is an overall view with a part cut away, and FIG. 3 is a sectional view taken along the line - be. DESCRIPTION OF SYMBOLS 1... Valve box, 3... Valve body, 3A... Valve body side annular seat part, 4... Soft rubber lining, 5... Hard rubber lining, 6... Membrane body.

Claims (1)

[Scope of utility model registration request] It is a butterfly valve in which a hard rubber lining 5 is provided on the valve body 3 and a soft rubber lining 4 is provided on the inner peripheral surface of the valve body 1, and the annular seat portion 3 of the valve body 3
A is a butterfly valve in which a membrane body 6 having lower friction than the hard rubber 5 lining the valve body 3 is attached in a chevron-shaped cross-sectional shape with the top located on the outer peripheral edge side of the valve body 3.