JP2608489B2 - Joint for removing resin pipe - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a joint for taking out a resin pipe for connecting a metal pipe and a resin pipe.

[Prior Art] In order to connect a metal tube and a resin tube, a joint has been proposed in which a portion connected to the metal tube is formed of metal and a portion connected to the resin tube is formed of resin. As a conventional joint, the resin part is exclusively injection-molded in a mold containing the metal part of the joint,
The metal part and the resin part were integrally formed (Japanese Utility Model Publication No. 55-22312, Japanese Utility Model Publication No. 59-31987, Japanese Utility Model Publication No. 61-1986).
18302).

[Problems to be Solved by the Invention] The above-mentioned conventional joint for removing a resin pipe has a high manufacturing cost because there is no other way but to manufacture the joint by exclusively injection-molding the resin part in a mold containing the metal part of the joint. There was a problem of becoming. Also, since the metal part and the resin part are not fastened and fixed, if the metal part and the resin part peel off due to the difference in thermal expansion between the metal part and the resin part due to temperature change, etc. There is a problem that it causes the destruction of sex.

Therefore, an object of the present invention is to provide a joint for taking out a resin pipe which is easy to manufacture and has a reliable sealing property.

Means for Solving the Problems The present invention has been made to achieve the above object, that is, a joint body having a female thread at one end and a groove at an inner peripheral surface at the other end, A resin coating layer having a tubular portion that covers the outer surface of the joint body and protrudes from the other end of the joint body; one end of the joint body is fitted to the other end of the joint body; A resin short tube protruding from an end side, a packing in which an inner surface is in contact with the resin short tube and an outer surface is in contact with the inner surface of the other end of the joint body and the inner surface of the cylindrical portion of the resin coating layer; A resin pipe take-out joint comprising a stiffener fitted on the inner surface of the one end side of the short pipe, and expanding the stiffener to fix the resin short pipe to the joint body.

[Operation] When the diameter of the stiffener fitted to the inner surface of one end of the resin short tube is increased, the diameter of one end of the resin short tube is also increased. Since the packing is pressed between the resin short tube and the inner surface of the other end of the joint body and the inner surface of the cylindrical portion of the resin coating layer, the packing is pressed at the same time to exert the pull-out inhibiting force by being engaged in the groove formed in the groove. Prevents leakage of internal fluid and entry of external fluid.

[Example] The present invention will be described with reference to the drawings. FIG. 1 is an upper half cross-sectional lower half front view of an embodiment of a joint for taking out a resin pipe according to the present invention, in which a female screw 1a is engraved on a left end side of a joint main body 1, and an inner surface on a right end side is provided. A plurality of grooves 1b are formed in the circumferential direction. The outer surface of the joint main body 1 is covered with a resin coating layer 2, and the resin coating layer 2 protects the outer surface of a connection portion between the joint main body 1 and a metal pipe (not shown) connected to the female thread 1 a of the joint main body. To fulfill, a protrusion protruding from the left end side of the joint body 1
2a, and a cylindrical portion protruding from the right end side of the joint body 1
Also has 2b.

On the inner surface of the groove 1b formed on the inner surface on the right end side of the joint body 1,
The left end side of the polyethylene short tube 3 is fitted, and the right end side of the polyethylene short tube 3 protrudes from the right end side of the joint body 1. A polyethylene pipe 4 is connected to the right end of the polyethylene short pipe 3 by an appropriate means. In FIG. 1, the case where the polyethylene short tube 3 and the polyethylene tube 4 are connected by the electrofusion or the heat fusion via the welding tube 5 is shown by a virtual line.

A packing 6 is fitted on the outer surface of the intermediate portion of the polyethylene short tube 3. Therefore, the outer surface of the packing 6 is in contact with the inner surface of the right end portion of the joint body 1 and the inner surface of the cylindrical portion 2 b of the resin coating layer 2.

A stiffener 7 having a flange protruding outward at the left end of the cylindrical shape is fitted on the inner surface on the left end side of the polyethylene short tube 3, and this flange is formed to facilitate positioning of the stiffener 7. Is what it is. The stiffener 7 is expanded from its original shape and fixes the polyethylene short pipe 3 to the joint body 1 in the expanded state. Therefore, it is necessary that the stiffener 7 can be plastically deformed by an external force to expand the diameter. In the example, the stiffener 7 is formed of copper.

2 and 3 show one means of manufacturing the joint for removing a resin pipe of the above embodiment. The polyethylene short tube 3 fitted with the stiffener 7 is fitted,
Insert the jig from the right end or left end. The figure shows a case where the jig is inserted from the right end side. In this embodiment, as the jig, a T member 10 having a disk fixed to the left end of a round bar,
A rubber bulge composed of a cylindrical rubber 11 and a cylindrical member 12 fitted to the round bar portion of the member 10 was used.

In this embodiment, the diameter of the stiffener 7 is increased by the rubber bulge in two steps. First, the rubber 11 is positioned so as to reach the groove 1b of the joint body (FIG. 2), and the rubber 11 is compressed. When the T member 10 and the cylindrical member 12 are pressed so that the rubber 11 expands, the stiffener 7 also expands, so the polyethylene short tube 3 also expands, and its outer surface is placed in the groove 1b of the joint main body. Bite. Thereafter, when the compression of the rubber 11 is released, the rubber 11 returns to the original shape, but the copper stiffener 7 is plastically deformed and maintains the deformed shape.

Then, using a smaller rubber bulge, the rubber 11 is positioned so as to reach the packing 6 (FIG. 3).
When compression is performed, the rubber 11 expands in diameter, so the stiffener 7 also expands and maintains its shape, so that the polyethylene short tube 3 also expands in diameter, and the packing 6 becomes in contact with the polyethylene short tube 3 and the right end inner surface of the joint body 1. And the inner surface of the cylindrical portion 1b of the resin coating layer 2 is pressed.

In the example in which the polyethylene short pipe 3 having a nominal diameter of 25 ^A is fixed to the joint body 1, when the diameter is expanded at about 2.000 kg · f as the primary expanding force and at about 1,000 kg · f as the secondary expanding force, the resin cladding tube is formed. 3
Was fixed to the joint body 1 without excessive deformation, and the sealing action by the packing 6 was also optimal. The primary diameter expansion and the secondary diameter expansion can be performed by the same rubber bulge, or a single rubber bulge can be used for one diameter expansion. Further, the diameter of the stiffener 7 may be expanded by other means, that is, the present invention does not ask about the means of expanding the stiffener 7.

The present embodiment is configured as described above, and the polyethylene short pipe 3 exerts a pull-out inhibiting force because it is bitten into the groove 1b of the joint main body 1, and the packing 6 is formed between the polyethylene short pipe 3 and the joint main body 1. It is pressed between the right end and prevents the leakage of the internal fluid, and furthermore, the polyethylene short pipe 3 and the resin coating layer 2
And presses against the cylindrical portion 2b to prevent entry of an external fluid, thereby achieving external corrosion protection. In addition, since the biting of the polyethylene short tube 3 into the groove 1b and the pressing of the packing 6 are maintained by the plastic deformation of the stiffener 7, even if there is a temperature change or the like, the function of the joint for removing the resin tube may be impaired. In addition, since it is not necessary to integrally form the polyethylene short pipe 3 with the joint body 1, it is easy to manufacture the present joint for removing a resin pipe.

[Effects of the Invention] According to the present invention, there is provided a joint for taking out a resin pipe which is easy to manufacture and has a reliable sealing property between the inside and the outside of the joint.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an upper half sectional lower half front view of one embodiment of the present invention, FIG.
FIG. 3 and FIG. 3 are upper half cross-sectional lower half front views showing one method for manufacturing the same embodiment. DESCRIPTION OF SYMBOLS 1 ... Joint body, 1a ... Female thread, 1b ... Groove 2 ... Resin coating layer, 2a ... Projection part, 2b ... Cylindrical part 3 ... Polyethylene short pipe, 4 ... Polyethylene pipe 5 ... Welding tube, 6 Packing, 7 Stiffener 10 T member, 11 Rubber, 12 Cylindrical member

Claims (1)

(57) [Claims] 1. A joint body having a female thread on one end side and a groove formed on an inner peripheral surface on the other end side, and a tubular portion covering the outer surface of the joint body and projecting from the other end side of the joint body. A resin coating layer, one end side of which is fitted to the other end side of the joint body, the other end side is a resin short tube projecting from the other end side of the joint body, and the inner surface is in contact with the resin short tube and the outer surface is A packing that comes into contact with the inner surface of the other end of the joint body and the inner surface of the cylindrical portion of the resin coating layer, and a stiffener fitted to the inner surface of the one end of the short resin tube, and the stiffener is expanded in diameter. A resin pipe take-out joint in which the resin short pipe is fixed to the joint body.