JPS6233184Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a pipe joint that elastically joins a metal pipe and a synthetic resin pipe and prevents the two pipes from coming apart at the joint.

Conventionally, as this type of pipe joint, one having a structure as shown in a half-sectional view in FIG. 2 is known.

In this pipe joint, a groove G with a trapezoidal cross section is provided in the inner part where the rubber ring 3 is attached, and auxiliary rings with a triangular cross section are joined to both sides of the groove G, and a snap spring 4 is loaded between the two auxiliary rings. Make the socket R,
On the other hand, an annular groove 5 is provided on the outer periphery of the spigot S, and when the spigot S is inserted into the socket R, the snap spring 4 is locked in the annular groove 5 to prevent it from coming off. It is.

However, this conventional pipe joint has a complicated structure and a large number of parts, so it takes a long time to manufacture, which inevitably increases costs.

Moreover, there is a drawback that the snap spring 4 is easily separated due to deformation or damage.

The present invention overcomes these conventional drawbacks, and provides a pipe joint that allows the pipe to expand and contract, has a simple structure, and reliably prevents the pipe from separating.

Hereinafter, the present invention will be explained in detail with reference to the drawings.

FIG. 1 is a partial sectional view showing an embodiment of the present invention, in which 1 is a metal tube and 2 is a synthetic resin tube.

The metal pipe 1 is a steel pipe, a stainless steel pipe, etc.
An annular groove 11 is provided on the inner surface of the socket 13 at one end of the pipe 1,
The rubber ring 3 is installed in the groove 11. Socket 13
A locking protrusion 12 is formed in the inner part of the tube at a position spaced apart from the annular groove 11 by a predetermined distance so as to protrude into the socket. The locking protrusion 12 may be a continuous protrusion in the circumferential direction as shown in FIG. 1, or a discontinuous protrusion partially protruding.

The distal end of the socket 13 is subjected to a roll process 14 to increase the flatness strength of the tube and to form a shape that allows easy insertion of the synthetic resin tube 2.

On the other hand, the synthetic resin pipe 2 has a spigot 21 having an outer diameter smaller than the inner diameter of the socket 13 and slightly larger than the inner diameter of the locking protrusion 12, and an annular groove 22 on the outer periphery of the spigot 21. A tapered inclined surface 23 is formed at the tip of the spout.

The annular groove 22 is formed wider than the axial length of the tip of the locking projection 12 that is locked in the groove, and the outer diameter of the groove bottom is slightly smaller than the inner diameter of the locking projection 12. The locking protrusion 12 is configured to be able to move somewhat in the axial direction within the annular groove 22.

The connection between the metal pipe 1 and the synthetic resin pipe 2 is through the socket 13.
When inserting the spout 21 into the interior and driving the other end of the synthetic resin pipe 2 with a hammer or the like, the inclined surface 23 will engage the locking protrusion 12.
The locking protrusion 12 is fitted into the annular groove 22 and locked.

At this time, if the spigot 21 of the synthetic resin pipe 2 is heated and softened with a burner or the like and then pushed into the socket 13, the connection operation can be performed more smoothly.

In addition to this connection method, there is a plug 21 in the socket 13.
After the tube is inserted, a locking projection 12 may be formed by tightening the tube, and the locking projection 12 may be locked in the annular groove 22.

Since the pipe joint of the present invention has the above-mentioned configuration, when the pipe expands or contracts in the piping line, the locking protrusion protruding from the back of the socket moves into the annular groove provided on the outer periphery of the socket. The tube is allowed to expand and contract within the possible range, and if the tube expands or contracts beyond this range, separation of the tube will be reliably prevented.

In addition, since the spout is loosely fitted into the socket with a predetermined gap, this bending can be tolerated even if the pipe is twisted and rotated. Since the annular groove is provided all around the outer periphery of the spout, there is no possibility that the locking protrusion will escape from the annular groove, and separation of the pipe can be reliably prevented.

[Brief explanation of the drawing]

FIG. 1 is a partial sectional view showing an embodiment of the present invention, and FIG. 2 is a half sectional view showing a conventional pipe joint. DESCRIPTION OF SYMBOLS 1... Metal pipe, 11... Annular groove, 12... Locking protrusion, 13... Socket, 2... Synthetic resin pipe, 21...
... Socket, 22... Annular groove.

Claims (1)

[Scope of utility model registration request] An annular groove is provided on the inner surface of the socket of the metal tube, a rubber ring is installed in the groove, and a locking protrusion is formed at the back of the socket to squeeze the pipe and protrude into the socket. An annular groove wider than the axial length of the locking protrusion is provided on the outer periphery of the spout of the synthetic resin pipe to be fitted, and the spout is inserted into the socket to bring the rubber ring into close contact with the outer periphery of the spout. A pipe joint characterized in that a locking protrusion is movably locked in an annular groove.