CN111550621A - Socket connecting sealing element for nodular cast iron pipe - Google Patents

Abstract

The invention provides a bell and spigot joint sealing element for a nodular cast iron pipe, wherein a stress strain release hole group is arranged on the sealing element; the stress strain relief hole group comprises a plurality of stress strain relief holes which are uniformly distributed on the gasket in an array manner; the cavities of the stress strain relief holes extend from the end face of the seal in contact with the casting tube supply medium to the interior of the seal. The invention provides a sealing element which changes the structural form of the sealing element in the prior art, meets the sealing performance, and improves the service life of the sealing element by reducing the compression ratio of the sealing element after the sealing element is installed.

Description

A ductile iron pipe socket and socket connection seal

technical field

The invention belongs to the field of sealing equipment, in particular to a ductile iron pipe socket-socket connection seal.

Background technique

Ductile iron pipes are now widely used in the supply of pressure media, usually using a socket-type sealing structure, and the materials of the applied sealing rings are mostly rubber and derivatives. They belong to a clearance fit, and the production process of cast ductile iron pipes will produce different degrees of manufacturing tolerances. The tolerance between the socket and the socket fluctuates greatly, which is easy to cause poor sealing. Improving the casting process will greatly improve production. cost.

Citing the background technology in the invention publication document (CN201910866675.7), the sealing structure of the ductile iron pipe with a large compression ratio range is only suitable for general working conditions (such as conveying medium at room temperature); and when the working conditions are harsh (such as When transporting hot water with a high temperature, especially when the superheated water exceeds 100 degrees Celsius), because the compression ratio of the seal is too large, the seal is easily cracked or loses elasticity and fails.

SUMMARY OF THE INVENTION

In order to solve the problems of the prior art, the invention proposes a special seal for the socket and socket of a ductile iron pipe, which is suitable for superheated water and water vapor, has good sealing performance and has a long service life.

The technical scheme adopted in the present invention is as follows: a ductile iron pipe socket-socket connection seal, and the seal is provided with a stress-strain release hole group.

Further, the stress and strain relief hole group includes a plurality of stress and strain relief holes, and the stress and strain relief holes are uniformly distributed on the sealing member in an array.

Further, the cavity of the stress and strain relief hole extends from the end face in contact with the medium to the inside of the seal.

Further, the shape of the bottom surface of the stress and strain relief hole is a circle, a polygon, or a combination of a circle and a polygon.

Further, the cavity of the stress and strain relief hole is gradually reduced from the outside to the inside.

Further, the seal includes a support body and a gasket, and the support body is tightly connected with the gasket.

Further, the support body and the gasket are made of the same material and are integrally and tightly connected.

Further, the support body and the washer are made of different materials, the support body is a hard body part, and the washer is a soft body part; the shore hardness of the support body is 70 degrees to 95 degrees, and the shore hardness of the washer is 40 degrees. degrees to 70 degrees; the support body and the gasket are integrally and tightly connected.

Further, the support body is provided with a protruding portion matched with the groove of the socket rubber ring.

Further, two sides of the protruding portion are respectively provided with a mounting and disengaging surface and a pressure-bearing thrust surface.

The beneficial effects obtained by the present invention are as follows: in view of the situation that the traditional seals in the prior art will fail rapidly under the condition of excessive compression ratio, it is proposed to change the structural form of the seals in the prior art to satisfy the sealing performance of the prior art. At the same time, by reducing the compression rate of the seal after installation, the service life of the seal is increased.

(1) The seal of the present invention is provided with stress and strain release holes, and the stress and strain release holes are used to reduce the deformation that the seal needs to bear during the installation process, and improve the stability of the internal structure of the rubber gasket in the seal in a high temperature environment . At the same time, the stress and strain relief holes are arranged in a honeycomb shape, that is, an array arrangement. The gap between adjacent stress and strain relief holes will form a rib-like structure, which improves the bearing capacity of the seal itself, and will not decrease when the maximum allowable limit of the socket and socket gap is reached. The sealing effect of the sealing structure will not reduce the service life due to the excessive compression rate of the rubber gasket when the socket and socket clearance is at the minimum allowable limit.

(2) Protruding parts are arranged on the support body at the end of the seal, and the structure of the installation and pressure-bearing anti-removal surfaces can effectively reduce the movement of the socket interface during the installation process, and avoid working The problem of the extrusion of the seal caused by the medium pressure in the state.

(3) The support body is a hard body part, and the gasket is a soft body part structure design, which can provide the supporting force during the installation of the pipeline through the high Shore strength of the material of the hard body part, and avoid the gap between the two sockets during the installation process. the eccentricity, and improve the alignment accuracy.

(4) The setting of the conical cavity of the stress and strain relief hole reasonably divides the rubber volume between the sealing surface of the socket and the sealing surface of the socket. At the same time of falling, it has a good sealing effect, which improves its service life in hot pressure medium.

Description of drawings

1 is a schematic diagram of the structure of the bottom surface of the gasket when the bottom surface of the stress and strain relief hole of the present invention is a circle;

2 is a schematic diagram of the structure of the bottom surface of the washer when the bottom surface of the stress and strain relief hole of the present invention is a triangle;

Fig. 3 is the sectional structure schematic diagram of the AA place on Fig. 1 of the present invention;

Fig. 4 is the sectional structure schematic diagram of the AA place on Fig. 2 of the present invention;

Fig. 5 is the sectional structure schematic diagram when the present invention is located in the socket;

6 is a schematic cross-sectional structure diagram of the first embodiment of the present invention;

Among them, 1 represents the support body, 2 represents the gasket, 3 represents the stress and strain relief hole, 4 represents the socket of the ductile cast pipe, 5 represents the installation stop surface, 6 represents the pressure bearing thrust surface, and 7 represents the socket of the ball milled cast pipe.

Detailed ways

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, but not all of the embodiments.

As shown in Figures 1-6, a ductile iron pipe socket-socket connection seal is provided with a stress and strain relief hole group on the seal. The stress and strain relief hole group includes a plurality of stress and strain relief holes 3 , and the stress and strain relief holes 3 are uniformly distributed on the sealing member in an array. The cavity of the stress and strain relief hole 3 extends from the end face in contact with the medium to the inside of the seal. The shape of the bottom surface of the stress and strain relief hole 3 is a circle, a polygon, or a combination of a circle and a polygon. The cavity of the stress and strain relief hole 3 is gradually reduced from the outside to the inside. The seal includes a support body 1 and a gasket 2, and the support body 1 and the gasket 2 are tightly connected.

The support body 1 and the gasket 2 can be made of the same elastic material or different materials, and are integrally and tightly connected. When the support body 1 and the washer 2 are made of different materials, the support body 1 is the hard part and the washer 2 is the soft part; the shore hardness of the support body 1 is 70 to 95 degrees, and the shore hardness of the washer 2 is 40 degrees to 70 degrees. The support body 1 is provided with a protruding portion matched with the socket rubber ring groove; the two sides of the protruding portion are respectively provided with a mounting and disengaging surface 5 and a pressure-bearing thrust surface 6 to make the installation more secure.

Specific embodiment one:

In this embodiment, a DN400 specification ductile iron pipe is selected. As shown in Figures 2 and 4, the stress and strain relief holes are evenly arranged in an array with the circular center of the seal body as the center. A stress and strain relief hole is evenly arranged every 6 degrees. The shape of the stress and strain relief hole at the bottom surface of the gasket is an isosceles triangle with an obtuse angle of 120 degrees and an acute angle of 30 degrees. The adjacent two stress and strain relief holes are symmetrically arranged to form a spacer. A continuous arrangement of ribs. As shown in Figure 5, during installation, the protruding part of the seal support body 1 is engaged with the rubber ring groove of the ball milled casting pipe socket 4, and the protruding part is provided with an installation stopper matched with the rubber ring groove of the ball milled casting pipe socket 4 The stripping surface 5 and the thrust surface 6 resisting the pressure of the medium can effectively reduce the play of the socket interface during the installation process, and the problem of the extrusion of the seal caused by the pressure during the medium supply.

The conical cavity of the stress and strain relief hole 3 is arranged parallel to the sealing surface of the ball milled casting pipe socket 4 near the side busbar of the ball milled casting pipe socket 4, and the conical cavity close to the socket side busbar and the ball milled cast pipe socket 7 The sealing surface of the socket 7 is arranged in parallel, It can make the socket 7 of the grinding pipe inserted into the socket 4 of the ball grinding pipe more smoothly, and the stress and strain relief hole 3 can be released more smoothly.

The air in the conical cavity is easier to be quickly squeezed out, the resistance is smaller, and the work efficiency is improved.

As shown in Figure 6, when the ball milled casting pipe socket 7 is inserted into the ball milled casting pipe socket 4, the sealing surface of the seal socket will be deformed by extrusion first, and the stress and strain relief hole 3 will be pre-stressed before the pressure deformation of the seal. From the cavity to the semi-closed state, the rib-like arrangement between the conical cavities will provide subsequent support. The compressive stress between the contact surface of the socket and the contact surface of the socket meets the sealing requirements. In the medium supply state, the pressure generated by the medium will be transmitted to the inside of the seal through the conical cavity to help improve the sealing effect. In the conventional knowledge of personnel, to avoid casting tolerances and improve the sealing effect, the compression ratio of the seal in the installed state exceeds 40%, which greatly reduces the service life of the seal in the hot pressure medium. The stress causing its failure is concentrated in the middle of the area with a large compression rate, resulting in bevel cut or cracking. In order to avoid this situation, reduce the degree of strain generated by the internal stress of the seal, and add stress and strain to the seal. The release hole can increase its service life under the condition of meeting the casting tolerance, and ensure the sealing effect of the seal in the socket and the socket contacting the sealing surface.

Specific embodiment two:

As shown in Figures 1 and 3, the stress and strain relief holes 3 on the contact surface between the seal and the pipeline supply medium are arranged in a circular double row dislocation, and the stress and strain relief holes 3 take the circular center of the seal as the center, along the direction of the seal It constitutes a plane divergent setting; that is, the stress and strain relief holes are arranged in two rows, and the inner ring and the outer ring are dislocated. Each row of stress and strain relief holes is centered on the circular center of the seal body, and one is equally divided every 2.5 degrees on the seal. Stress and strain relief holes are provided with a 1.25-degree dislocation between the front and rear rows. The stress and strain relief holes 3 are arranged in two sections in the inner part of the seal, the side close to the outer surface of the seal is a cylinder, and the side away from the outer surface of the seal is a cone. When the ball milled casting pipe socket 7 is inserted into the ball milled casting pipe socket 4, since the sealing member is arranged to widen radially towards the pipe body on the contact surface of the socket, the stress on the sealing member will gradually increase as the ball milled casting pipe socket 7 is inserted into the socket 7. Until the ball milled casting pipe socket 7 passes through the seal, the cavity volume of the stress and strain relief hole 3 will gradually decrease with the insertion of the ball milled casting pipe socket 7, thereby reducing the problem of excessive compression caused by manufacturing tolerances.

Claims (10)

1. A ductile iron pipe socket-socket connection seal, characterized in that: the seal is provided with a stress-strain release hole group. 2. A ductile iron pipe socket-socket connection seal according to claim 1, characterized in that: the stress and strain relief hole group comprises a plurality of stress and strain relief holes (3), and the stress and strain relief holes (3) It is evenly distributed on the seal in an array. 3 . The ductile iron pipe socket-socket connection seal according to claim 2 , wherein the cavity of the stress and strain relief hole ( 3 ) extends from the end face in contact with the medium to the inside of the seal. 4 . 4. A ductile iron pipe socket-socket connection seal according to claim 3, characterized in that: the shape of the bottom surface of the stress and strain relief hole (3) is a circle, a polygon, or a combination of a circle and a polygon. 5. The ductile iron pipe socket-socket connection seal according to any one of claims 2-4, wherein the cavity of the stress and strain relief hole (3) gradually shrinks from the outside to the inside. 6. A ductile iron pipe socket-socket connection seal according to claim 2, characterized in that: the seal comprises a support body (1) and a washer (2), the support body (1) and the washer (2) )tight connection. 7 . The ductile iron pipe socket-socket connection seal according to claim 6 , wherein the support body ( 1 ) and the gasket ( 2 ) are of the same material and are integrally and tightly connected. 8 . 8. A ductile iron pipe socket-socket connection seal according to claim 6, characterized in that: the support body (1) and the gasket (2) are made of different materials, and the support body (1) is a hard part, The washer (2) is a soft part; the shore hardness of the support body (1) is 70 to 95 degrees, and the shore hardness of the washer (2) is 40 to 70 degrees; the support (1) It is tightly connected with the gasket (2). 9. The ductile iron pipe socket-socket connection seal according to any one of claims 6-8, characterized in that: the support body (1) is provided with a protruding portion matched with the socket rubber ring groove. 10 . The ductile iron pipe socket-socket connection seal according to claim 9 , wherein the two sides of the protruding portion are respectively provided with a mounting and disengaging surface ( 5 ) and a pressure-bearing thrust surface ( 6 ). 11 .

Images