JPH0211672Y2 - - Google Patents

Description

[Detailed description of the invention] The present invention relates to a connection structure between a corrosion-proof pipe body and a corrosion-proof pipe joint, and more specifically, it relates to an improvement of the one disclosed in Japanese Utility Model Application Publication No. 177679/1985, which was previously proposed by the applicant. It is.

The present applicant has developed an elastic O
A ring is inserted into the elastic O-ring, and the elastic O-ring is pressed by one of two stepped portions provided around each of the tapered portions that gradually open toward the outside on the inner peripheral surface of both ends of the anti-corrosion sleeve. In 177679/1987, a joint body was deformed so that a plurality of anti-corrosion pipe bodies could be screwed together. It has been newly discovered that the elastic O-ring may shift and twist during connection, and that when this twist occurs, a problem arises in that the expected airtightness cannot be obtained.

Therefore, the present invention was developed as a result of intensive studies in view of the above circumstances, and instead of using the elastic O-ring, an elastic ring with a substantially rectangular cross section and flat in the axial direction is used to solve the above problems. This solution eliminates the possibility of misalignment of the elastic ring when the anti-corrosion pipe body is screwed together, without sacrificing the advantages of what was described in Japanese Utility Model Application Publication No. 58-177679. The purpose of the present invention is to provide an improved and highly reliable connection structure between a corrosion-resistant pipe body and a corrosion-resistant pipe joint.

That is, the present invention provides an outer covering layer of a corrosion-resistant pipe body in which the outer circumferential surface of the pipe joint body is covered with a synthetic resin anti-corrosion sleeve extending outward from the end thereof, and is covered with an anti-corrosion layer. is peeled off over a predetermined length from the end, and the part where the outer coating layer of the corrosion-resistant pipe body has been peeled off is
In the connection structure of the corrosion-proof pipe fitting and the corrosion-proof pipe body, which are inserted through the end opening of the corrosion-proof sleeve and threadedly connected within the pipe fitting body through the end opening of the pipe fitting body, the pipe fitting body A step portion bulging radially inward is provided around the axially intermediate portion of the inner circumferential surface of the anticorrosive sleeve that extends outward from the outer circumferential end of the anticorrosive sleeve, and the outer covering layer of the anticorrosive pipe is An elastic ring having a substantially rectangular cross section with flat inner and outer circumferential surfaces is fitted onto the stripped outer circumferential surface, and this elastic ring is inserted together with the anti-corrosion pipe through the end opening of the anti-corrosion sleeve, and the protruding corner of the stepped portion is fitted. At the same time, the anti-corrosion pipe body is screwed into the pipe joint main body, and the elastic ring is pressed and deformed by the end of the outer covering layer of the anti-corrosion pipe body and the protruding corner of the step part. This seals the space between the anti-corrosive sleeve and the anti-corrosive tube body.

A preferred embodiment of the present invention will be described below with reference to the accompanying drawings. FIG. 1 shows an example in which the joint used in the present invention is applied to a socket type pipe joint.

In the figure, reference numeral 1 denotes a pipe fitting body having a threaded portion 11 on the inner circumferential surface without an outer covering layer 31. The corrosion-resistant sleeve 2 is made by coating an extending synthetic resin such as polyethylene with excellent corrosion resistance or a metal pipe body with a synthetic resin having excellent corrosion resistance.
Tapered portions 22, 22 that gradually open outward are formed on the inner circumferential surfaces 21, 21 to facilitate insertion of the anti-corrosion tube body 3, and the shafts of these tapered portions 22, 22 are further formed. A plurality of step portions 23, 23 that bulge inward in the radial direction are formed in the intermediate portion in the direction.

In contrast to such a pipe fitting main body 1, the other anti-corrosion pipe body 3 has a threaded portion 32 formed at the end portion covered with the anti-corrosion layer 31, and this threaded portion 32 is attached to the pipe fitting. It is adapted to be screwed into the above-mentioned threaded portion 11 of the main body 1, and each of the anticorrosive pipe bodies 3
An elastic ring 4 having a substantially rectangular cross section and flat inner and outer circumferential surfaces is fitted onto the uncoated outer circumferential surface of the anticorrosive outer coating layer 31 that is coated on the outer surface 33 of the metal tube 34. There is.

This elastic ring 4 is preferably one that can be stably fitted onto the outer peripheral surface of the metal tube 34 of the anti-corrosion tube body 3 having a rectangular cross section as shown in FIGS. 3 to 7, for example. It is preferable that the material be fitted onto the uncoated outer circumferential surface of the anticorrosive outer covering layer 31 in No. 3 with an appropriate tightness.

Each of the elastic rings 4 shown in FIGS. 3 to 7 has a shape in which the circumferential surface 4a of the corner portion is cut off. Uncoated outer peripheral surface 33 of the coating 31
This is particularly desirable when the elastic ring 4 is to be stably fitted into the body.

It goes without saying that the present invention is equally applicable not only to such socket-type pipe joints but also to pipe joint bodies such as elbows and tees.

The elastic ring 4 fitted onto the peeled outer peripheral surface of the outer covering layer 31 of the anti-corrosion pipe body 3 is inserted from the end opening of the anti-corrosion sleeve 2 together with the anti-corrosion pipe body 3 to form the plurality of steps. 23, and screw the anti-corrosion pipe body 3 into the pipe joint main body 1, so that the elastic ring 4 is connected to the end of the outer covering layer 31 of the anti-corrosion pipe body 3 and the plurality of By pressing and deforming the stepped portion 23 at the protruding corner, the space between the anti-corrosion sleeve 2 and the anti-corrosion tube body 3 is sealed.

It goes without saying that the present invention is equally applicable not only to such socket type pipe joints, but also to elbow, tees, etc. pipe joints.

According to the connection structure of the corrosion-proof pipe body and the corrosion-proof pipe joint of the present invention, the corrosion-proof pipe joint can be manufactured easily.

Furthermore, the elastic ring can be fitted onto the peeled outer peripheral surface of the outer coating layer of the anticorrosive tube body, and the elastic ring can be easily and properly fitted both at the factory production stage and on-site.

Then, an elastic ring fitted onto the peeled outer circumferential surface of the outer coating layer of the anti-corrosion pipe is inserted from the end opening of the anti-corrosion sleeve together with the anti-corrosion pipe, and the anti-corrosion pipe is inserted into the main body of the pipe joint. By screwing into the elastic ring, the above-mentioned elastic ring hits the protruding corner of the step provided on the inner circumferential surface of the anti-corrosion sleeve, and the end of the outer sheath layer of the anti-corrosion tube body from which the outer sheath layer has been peeled off. and the protruding corner of the stepped portion, and the space between the anti-corrosive sleeve and the anti-corrosive pipe body is highly sealed, so the anti-corrosive pipe body and the anti-corrosive pipe fitting can be connected without any troublesome work of connecting the anti-corrosive pipe body. A high degree of sealing can be achieved between.

In this case, the elastic ring is easily pressed and deformed by the protruding corner of the stepped portion provided around the inner circumferential surface of the anti-corrosion sleeve and gradually as the anti-corrosive pipe body is screwed into the anti-corrosion pipe. When screwing the body into the pipe joint body, there is no problem such as the need for a very large screw force, and the corrosion-resistant pipe body can be easily screwed into the pipe joint body, and the stepped part Since the elastic ring is greatly deformed by the protruding corner, it is possible to reliably seal the space between the anti-corrosion sleeve and the anti-corrosion pipe body for a long period of time, and therefore the seal between the anti-corrosion pipe body and the anti-corrosion pipe fitting is maintained. It is very suitable for sealing.

In addition, instead of the elastic O-ring described in Japanese Utility Model Application Publication No. 58-177679, an elastic ring fitted onto the peeled outer circumferential surface of the outer coating layer of the anti-corrosion pipe body has a substantially rectangular cross section with flat inner and outer circumferential surfaces. This shape prevents the elastic ring from shifting and twisting when the anti-corrosion pipe body is screwed into the pipe joint body, thereby preventing a gap from being formed.

In addition, in the embodiment described above, since a plurality of steps 23, 23 are formed on the inner circumferential surfaces 21, 21 of the anti-corrosion sleeve 2, there is no variation within the tolerance in the pipe diameter of the anti-corrosion pipe body 3 to be connected. Even in such cases, by selecting the steps appropriately, the pipe bodies can be connected in a more reliable airtight manner, so it is extremely useful for use in gas piping where airtightness is strongly required. be.

[Brief explanation of drawings]

Fig. 1 shows an embodiment of the present invention, and Fig. 2 is a partially cutaway vertical cross-sectional view showing the connection structure of a corrosion-proof pipe body and a corrosion-proof pipe joint. The top view and FIGS. 3 to 7 are cross-sectional views showing modified embodiments of the elastic ring. Explanation of symbols, 1... Pipe joint body, 2... Corrosion-proofing sleeve, 21... Inner peripheral surface of its end, 22... Tapered part, 23... Step part, 3... Corrosion-proofing pipe body, 4... Elastic ring , 33... Exfoliated outer peripheral surface of the outer covering layer.

Claims (1)

[Scope of Claim for Utility Model Registration] An outer covering of a corrosion-resistant pipe body in which the outer peripheral surface of the pipe joint body is covered with a synthetic resin anti-corrosion sleeve that extends outward from the end thereof, and is coated with an anti-corrosion layer. The layer is peeled off over a predetermined length from the end, and the part of the corrosion-proof pipe body from which the outer covering layer has been peeled off is inserted from the end opening of the corrosion-proof sleeve and passes through the end opening of the pipe fitting body. In the connection structure of a corrosion-proof pipe body and a corrosion-proof pipe joint that are threadedly connected within the pipe joint body, the axis of the inner circumferential surface of the anti-corrosion sleeve that extends outward from the end of the outer circumferential surface of the pipe fitting body. A stepped portion that bulges inward in the radial direction is provided around the intermediate portion, and an elastic ring having a substantially rectangular cross section and flat inner and outer circumferential surfaces is fitted to the peeled outer circumferential surface of the outer coating layer of the anticorrosive pipe body. The elastic ring is inserted into the end opening of the anticorrosive sleeve together with the anticorrosive pipe body so as to hit the protruding corner of the stepped part, and the anticorrosive pipe body is screwed into the main body of the pipe joint. , a corrosion-proof pipe body characterized in that the elastic ring is pressed and deformed at the end of the outer covering layer of the corrosion-proof pipe body and the protruding corner of the step part to seal the space between the corrosion-proof sleeve and the corrosion-proof pipe body. and the connection structure of anti-corrosion pipe joints.