JPS63180791A - Pipe joint - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a so-called flange-clamped □ seal-type pipe joint used for connecting supply/drainage pipes, etc.

(Conventional technology) Conventionally, an example of such a pipe joint is shown in FIG.

A pipe B to be connected is fitted into a main body A of a pipe joint having a flange protruding from the outer periphery, and a concave portion for receiving a gasket formed in a tapered shape on the inner periphery of the end of the main body A, and an outer periphery of the pipe B. A gasket C is interposed between the gasket C and the gasket C is compressed by tightening the gasket press flange D using a screw member E screwed into the flange of the main body A and the gasket press flange D, thereby improving its elasticity and wedge effect. There is a structure that maintains the seal and connects.

However, in this case, due to the nature of the seal holding method, it is easy to tighten the screw member E more than necessary in order to ensure safety.

This is also the case because even if the torque for proper tightening of a screw member is specified, it cannot be actually regulated.

Therefore, after the seal C is tightened, it suffers from a large permanent strain due to compression, resulting in a shortened service life and a disadvantage in that it lacks long-term seal retention ability.

On the other hand, since the number of screw members is usually about 2 to 4, they tend to be tightened unevenly, which often causes seal failure. Flanges made of cast iron often break.

(Problems to be Solved by the Invention) The present invention has been devised in view of the drawbacks of the conventional pipe joints described above, and is designed to prevent the threaded member from being abnormally tightened beyond the appropriate value. The purpose of the present invention is to provide a pipe joint that maintains long-term sealing performance by reducing the permanent strain caused by compression applied to the fitting, and that effectively prevents seal failure and flange damage by restricting uneven tightening. do.

(Means for Solving the Problems) The configuration of the pipe joint according to the present invention for solving the above problems includes fitting a pipe into the main body of the pipe joint having a flange protruding from the outer periphery, A packing is inserted between the packing receiving recess formed on the inner peripheral edge of the end of the main body and the outer periphery of the limb canal, and the packing is removed by tightening the packing pushing flange against the former flange with a screw member. A pipe joint that connects limbs by compressing the flange, and the present invention provides a fitting (action) between the flange and the packing pushing flange. When the packing is compressed, its elasticity brings it into pressure contact with the packing-receiving recess and the outer periphery of the pipe to maintain the seal. Since the body is also compressed between them, it becomes difficult to tighten the threaded member at that stage, and this serves to prevent or restrict tightening more than necessary, and to reduce the permanent strain that the packing receives due to compression. This serves to prevent uneven tightening of members.

(Example) A first example of a pipe joint according to the present invention will be described with reference to FIG.

In the figure, 1 is the main body of the pipe joint (hereinafter simply referred to as the main body), and its inner diameter is slightly larger than the outer diameter of the limb pipe P so that the pipe P to be connected can be fitted therein. The end portion thereof is provided with a flange 2 projecting from the outer periphery, and the inner periphery thereof is provided with a packing receiving recess 3 formed with a tapered surface whose diameter increases toward the end portion.

Reference numeral 4 denotes a packing made of an elastic material such as rubber and having a generally wedge-shaped cross section and an annular shape;
It is interposed between the packing receiving recess 3 and the outer periphery of the pipe P.

Next, reference numeral 5 denotes a packing pressing flange, which is formed into an annular shape with an inner diameter slightly larger than the outer diameter of the pipe P, and has a packing pressing surface that makes surface contact with the packing 4 on the inner peripheral edge spine on the packing side. A bolt 7 as a threaded member is screwed between the bolt 7 and the flange 2 of the main body 1 on the outside thereof, and by tightening the bolt 7 and nut 8, the seal pressing flange 5 is pressed against the seal. 4.

Now, reference numeral 9 denotes an intermediate body which is the gist of the present invention, and is formed in a cylindrical shape, and one end of which is interposed between the flange 2 of the main body and the packing pushing flange 5. It is fitted in a planted manner on the outside of the pressing surface 6, and the other end is such that the bolt 7 is tightened in such a way as to maintain a gap from the 2 faces of the flange of the main body 1 by the amount remaining after proper tightening of the gasket 4. Although not shown in the figure, a case where a plurality of devices are provided will be exemplified. However, it is preferable that the intermediate bodies 9 correspond to the number of bolts and are arranged at equal angular intervals with respect to the center.

The intermediate body 9 should preferably be made of rubber (if this is the case, the other end may be in contact with the flange 2 of the main body even before the bolt 7 is tightened).

Although the intermediate body 9 in this embodiment is exemplified as being fitted onto the packing pressing flange 5, it may be formed integrally therewith, and the shape thereof does not necessarily have to be cylindrical. It is obvious from its structure that it does not.

As a result, the packing 4 is compressed and its elasticity brings it into pressure contact with the packing receiving recess 3 and the outer periphery of the pipe P to maintain a seal. Because a sudden large torque is required,
At that stage, the tightening is automatically regulated, and the operator can recognize that the tightening has been completed with the appropriate torque, preventing abnormal tightening and suppressing permanent deformation of the packing 4. Furthermore, in this case, no matter which bolt is tightened, the intermediate body is compressed, and excessive tightening is automatically regulated, thereby preventing uneven tightening.

Next, regarding the second and third embodiments of the pipe joint according to the present invention, the first embodiment will be explained based on FIGS. 2 and 3, respectively.
The explanation will focus on the differences from the embodiment.

That is, in the second embodiment, as shown in FIG.
The only difference is that the second embodiment is fitted to the outside of the third embodiment in a planted manner, and the other points are the same as those of the first embodiment, so a description thereof will be omitted.

Moreover, as shown in FIG. 3, the intermediate 2 in the third embodiment
Numeral 9 has a cylindrical shape and is interposed between the flange 22 of the main body 21 and the seal pressing flange 25 by inserting a bolt 27 into the cylindrical shape.

In principle, the number of intermediate bodies 29 in this case is the same as the number of bolts 27, but because of its structure, over-tightening can be prevented at certain points, and it can also be easily applied to conventional pipe joints. It has the convenience of

(Effects) In the pipe joint according to the present invention, the seal is not abnormally tightened beyond the appropriate value, and permanent distortion of the seal due to compression can be kept small, so long-term sealing performance is maintained. Moreover, it prevents uneven tightening.
This is extremely useful in practical terms, as it effectively prevents seal failures and flange damage.

[BRIEF DESCRIPTION OF THE DRAWINGS] FIGS. 1 and 3 are longitudinal cross-sectional views of main parts showing embodiments of the pipe joint according to the present invention. FIG. 1 shows the first embodiment, and FIG. FIG. 3 shows the third embodiment. Moreover, FIG. 4 is a longitudinal cross-sectional view of a main part showing a conventional example. P...Pipe 1, 11.21. ...Pipe joint body 2, 12
．． 22.・・・Fran
Ji3, 13.23. ...Packet receiving recess 4
, 14. 24. ...Pap
Kin 5, 15.25. ...Packing flange 7, 17.27. ...Bolt (screw member) 9, 19.29. ... Intermediate patent applicant Kojima Co., Ltd.

Claims (4)

[Claims] (1) A pipe is fitted into the main body of a pipe joint with a flange protruding from the outer periphery, and between the packing receiving recess formed on the inner periphery of the end of the main body and the outer periphery of the pipe. A pipe joint in which a packing is interposed between the pipe and the pipe is connected by compressing the packing by tightening a packing pushing flange against the flange with a screw member, the pipe fitting connecting the pipe by tightening the packing pushing flange against the flange with a screw member. In contrast, a pipe joint characterized in that when the packing is compressed, an appropriate number of intermediate bodies are interposed to undergo compression. (2) The pipe joint according to claim 1, wherein the intermediate body has one end fitted in a planted manner on the outside of the packing pressing surface of the packing pressing flange. (3) The pipe joint according to claim 1, wherein the intermediate body has one end fitted in a implanted manner on the outside of the packing receiving recess of the main body. (4) The pipe joint according to claim 1, wherein the intermediate body has a cylindrical shape and a threaded member is inserted into the inside of the pipe fitting.