JPH0139990Y2 - - Google Patents

Description

[Detailed description of the invention] [Industrial field of application] The invention relates to an expansion joint, which is made of synthetic resin and is fitted into both open end faces of the joint body, and the packing is pressed into contact with the pipe body to which it is connected. It relates to a structure for fastening a flange body.

[Conventional technology]

Expansion joints that connect water pipes, drainage pipes, etc., have, for example, a cylindrical joint body into which the ends of the pipes to be connected are inserted, and a pair of approximately annular joints that fit into both ends of this body. The structure includes a flange body and a substantially annular packing made of rubber or the like that is held between the peripheral edges of both end faces of the main body and the inner peripheral edge of the flange body.

Furthermore, a plurality of protrusions having insertion holes are formed on the outer circumferential side of the pair of flange bodies, and bolts are inserted into the insertion holes of the opposing protrusions, and the bolts are tightened with nuts. There is. That is, when the ends of the pipe body to be connected to the joint body are fitted and the nut is tightened, both the flanges are tightened and the packing is attached to the peripheral edges of both end faces of the main body and the outer periphery of the pipe body. By being pressed against the surface, water leakage is prevented and the pipe body is connected.

In such expansion joints, it is known that the joint body is molded from synthetic resin, but the flange body is subject to a large load when the protruding part is tightened strongly with bolts and nuts. Therefore, it is made of cast iron with sufficient rigidity.

[Problem that the invention attempts to solve]

By the way, especially for expansion joints used in ships, etc., it is desirable that the joint be lightweight, but the conventional structure in which the flange body is molded from cast iron has the disadvantage that the flange body becomes heavy and easily rusts. .

Therefore, it is conceivable to mold the flange body from synthetic resin. Even if the flange body is molded from synthetic resin, the load applied when the flange body is tightened with bolts and nuts while it is in pressure contact with the joint body and pipe body to the extent that the packing exhibits a water-stopping function. On the other hand, the flange body originally molded from this synthetic resin can withstand this.

However, with the structure of the conventional expansion joint described above, even after the packing has been pressed to the extent that it exhibits a water-stopping function, the response when tightening the nut is not very clear, so the nut may be over-tightened more than necessary, resulting in There are problems such as the flange body being unable to withstand the load, resulting in deformation and damage.

The purpose of this invention is to mold the flange body from synthetic resin, which is lightweight, has excellent corrosion resistance, and can be mass-produced. It is an object of the present invention to obtain an expansion joint that is not subject to excessive loads and has good workability.

[Means for solving problems]

The expansion joint of the present invention has a substantially cylindrical joint body into which the pipes to be connected are inserted from both open end faces, and a pair of roughly annular flanges molded from synthetic resin that are fitted to both end faces of the joint body. an annular packing that is held between both end surfaces of the joint body and each inner peripheral edge of the flange body and is pressed against the outer peripheral surface of the pipe body, and bolts and nuts that fasten both the flange bodies. , a locking portion is formed integrally with the outer circumferential surface of the joint body at a position near the bolt and comes into contact with each inner surface of the flange bodies to restrict the approach distance of these flange bodies. It is characterized by:

[Effect]

In the expansion joint of the present invention, the ends of the pipe bodies to be connected are inserted from both open end faces of the joint body, and then the flange bodies fitted to both end faces of the joint body are tightened with bolts and nuts. Packing held between both end surfaces of the joint body and each inner peripheral edge of the flange body is pressed against the outer peripheral surface of the pipe body to prevent water leakage and connect the pipe bodies, and the outer peripheral surface of the joint body A locking part integrally formed with the main body at a position near the bolt is brought into contact with each inner surface of the two flange bodies to regulate the approach distance between the two flange bodies, and the locking part is molded from synthetic resin. This prevents these flange bodies from being tightened too strongly.

[Embodiment] The configuration of an embodiment of the present invention will be explained with reference to FIG.

Reference numeral 1 denotes a substantially cylindrical joint body made of synthetic resin by injection molding, and the peripheral edges of both opening end faces are formed into inclined surfaces that are inclined inwardly toward the inner diameter side.

A plurality of substantially cylindrical locking portions 2 are integrally formed with the main body 1, projecting in the outer radial direction from both ends of the outer circumferential surface of the joint main body 1, and arranged in pairs at the front and rear.
Each outer end surface of this locking portion 2 has a vertical surface 2a orthogonal to the outer circumferential surface of the joint body 1 at its base.
The distal end thereof is formed into an inclined surface 2b that is inclined outward in the outer diameter direction.

Reference numeral 3 denotes a pair of flange bodies molded from synthetic resin and fitted to both ends of the joint body 1, which are formed in a substantially annular shape. The periphery of the inner surface of the flange body 3 facing the periphery of both end surfaces of the joint body 1 is as follows:
It is formed into an inclined surface that is inclined inward toward the outer diameter side. Moreover, on the outer peripheral side of this flange body 3,
A plurality of protrusions 4 are provided at positions corresponding to the locking parts 2 of the joint body 1, and insertion holes 5 are formed in the protrusions 4. Further, each inner side surface of the protruding portion 4 is formed into a vertical surface 4a and an inclined surface 4b that are parallel to and opposite to the vertical surface 2a and inclined surface 2b of the locking portion 2, respectively. When the flange body 3 is fitted to both ends of the joint body 1 via the packing 6, the vertical surface 2a and the inclined surface 2b of the locking part 2 and the vertical surface 4a and the inclined surface of the protruding part 4 are connected to each other. 4b, so that a slight gap is created between the two.

The packing 6 is formed into an annular shape from an elastic material such as rubber, and is held between the peripheral edges of both end surfaces of the joint body 1 and the peripheral edges of each inner surface of the flange body 3.

Reference numeral 7 denotes a bolt, which is inserted into the corresponding insertion hole 5 of both flange bodies 3 and the locking part 2 of the joint body 1, and a nut 9 is screwed onto one end of the bolt through a washer 8. Both flange bodies 3 are adapted to be fastened together.

Next, the operation of this embodiment will be explained.

A pipe body to be connected, such as a water pipe or a drain pipe, is inserted from both open end faces of the joint body 1.

Next, when the nut 9 is tightened, the packing 6 is pressed by the peripheral edges of both end surfaces of the joint body 1 and the peripheral edges of each inner surface of the flange body 3, and receives a force in the radial direction, and this packing 6 By being pressed against the outer circumferential surface, water leakage is prevented and both pipe bodies are connected.

As the nut 9 is tightened in this way, the vertical surfaces 2a of the respective locking portions 2 of the joint body 1 become
The flange bodies 3 are stopped from approaching each other at a certain distance.

In this way, since the tightening of both flange bodies 3 by bolts 7 and nuts 9 is prevented at a certain point, both flange bodies 3 are not tightened more strongly than necessary, and this flange molded from synthetic resin The body 3 can withstand the load caused by tightening the bolts 7 and nuts 9.

Further, since the locking portion 2 is integrally molded with the joint body 1, the number of parts to be handled during work is reduced and work efficiency is increased, compared to a case where the locking body is provided separately from the joint body 1.

Furthermore, since the locking portion 2 is formed near the bolt 7 that is subjected to the largest load, a high locking effect can be obtained.

In addition, in the above embodiment, the vertical surface 2a of the locking part 2
Although a structure has been described in which the vertical surface 4a of the protrusion 4 of the flange body 3 is in contact with each other, as shown in FIG. The slopes 2b and 4b may be made wider so that the slopes 2b and 4b are in contact with each other.

In addition, in these embodiments, the locking portion 2 and the protruding portion 4 of the flange body 3 each have an inclined surface 2.
Since b and 4b are formed, positioning work can be easily performed.

[Effect of idea]

According to the present invention, the flange body that is fitted to both ends of the joint body through packing is molded from synthetic resin, making it lighter in weight, corrosion resistant, and easier to mass produce than when the flange body is molded from cast iron. In addition, a locking portion is formed near the bolt that fastens the flange body on the outer peripheral surface of the joint body, and the locking portion comes into contact with each inner surface of the flange body when tightened with a nut. Since the approach of these flange bodies was stopped,
These flange bodies are not tightened more than necessary, and therefore, these flange bodies molded from synthetic resin can withstand the load due to tightening.Furthermore, the locking portion is formed integrally with the joint body. This reduces the number of parts that need to be handled and improves work efficiency.

[Brief explanation of drawings]

FIG. 1 is a longitudinal sectional side view of an expansion joint showing one embodiment of the invention, and FIG. 2 is a longitudinal sectional side view of an expansion joint showing another embodiment of the invention. 1... Joint body, 2... Locking part, 3... Flange body, 6... Packing, 7... Bolt, 9...
Natsuto.

Claims (1)

[Scope of utility model registration request] A generally cylindrical joint body into which the pipes to be connected are inserted from both opening end faces, a pair of roughly annular flange bodies molded from synthetic resin that are fitted to both end faces of the joint body, and the joint body of the joint body. an annular packing that is held between both end faces and each inner circumferential edge of the flange body and pressed against the outer circumferential surface of the pipe body; and bolts and nuts that fasten the both flange bodies; An expansion joint characterized in that a locking portion is formed integrally with the main body at a position near the bolt to abut on each inner side surface of the flanges to restrict the approach distance between the flanges.