JPS6147236A - Shape controlling method of pipe joint - Google Patents

Abstract

PURPOSE:To eliminate the ragged strain of a pipe joint developed during its manufacturing and consequently obtain the pipe joint conforming to the normal shape and dimensions by a method wherein the intermediate portion of the pipe joint is softened by heating and controlled the shape utilizing the shrinkage of diameter developed by softening with a core. CONSTITUTION:The end pipe 7 of a pipe joint 1 is held on a pivoting power source 15 side, while the spigot part 3 of the pipe joint 1 is held with a pivoting socket 3. The intermediate portion 4 of the pipe joint 1 is softened by being heated with a heat source 17 under the state just mentioned above, resulting in causing the shrinkage of its diameter. After that, the pipe joint 1 is released and shifted to a core 13, the shape and dimensions of which conforms to those of the normal inner surface of the intermediate portion 4 of the pipe joint 1. The core 13 is inserted from the end pipe 7 side of the pipe joint 1 so as to abut the intermediate portion 4 against the core 13 by pushing the spigot part 3 with a press plate 19 in order to control the shape and dimensions of the inner surface of the intermediate portion 4. Next, the pipe joint is sildified by cooling. After the cooling of the pipe joint, the press plate 19 is separated from the pipe joint. Finally, the pipe joint is released from the core 13 by pushing up a stripper plate 20 (not shown in fig.) attached on the core 13. The pipe joint is used by fitting a packing 9 (not shown in fig.) in a grooved part 8.

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention is aimed at reducing the amount of unevenness that occurs during the manufacturing of pipe joints used for running water piping, etc., and in order to obtain pipe joints that conform to regular dimensions and shapes. This article relates to a method for regulating the shape of pipe joints.

(Prior art) In conventional water piping, etc., an opening is formed in a pipe joint body 1 which has a spout 3 at one end, an enlarged diameter intermediate section 4, and a socket section 6 whose other end has a further enlarged diameter. A pipe joint is used in which an end tube 7 having a grooved portion 8 into which a packing 9 is fitted is inserted into a socket portion 6 and bonded.

(Problems to be Solved by the Invention) In such a pipe joint, heat treatment may be performed to enlarge the diameter of the intermediate portion 4. However, depending on the thermal conditions in this case, the amount of unevenness 14 may occur in the intermediate portion 4, making it impossible to obtain a pipe joint that conforms to the regular dimensions and shape, and the use of the pipe fitting as a defective product had to be postponed.

The present invention is concerned with such uneconomical problems and provides a method for regulating the shape of a pipe joint in order to eliminate the amount of unevenness that occurs during the manufacture of the pipe joint and to obtain a pipe joint that conforms to regular dimensions and shapes.

(Means for Solving the Problems) Next, a method for regulating the shape of the pipe joint of the present invention will be described in more detail with reference to the drawings.

1 is a pipe joint main body, and a lid opening portion 3 is formed on one end side. The lid opening 3 is inserted into one end of the connecting pipe 11.

A stepped portion 5 is formed at the boundary between the intermediate portion 4 and the lid opening portion 3,
The end of the connecting pipe 11 is brought into contact with the end of the connecting pipe 11 to reach the insertion limit. The intermediate portion 4 is formed by expanding the diameter by heat treatment. The diameter of the other end of the pipe joint body 1 is further expanded to form a socket 6. An end tube 7 into which one end of the connecting tube 12 is inserted is inserted into the socket 6 and bonded to the socket 6. A groove-shaped portion 8 is formed at the open end of the end tube 7, and a packing 9 is fitted into the groove-shaped portion 8. A stepped portion 10 is formed at the boundary between the intermediate portion 4 and the socket portion 6, and the tube end portion of the end tube 7 is brought into contact with the stepped portion 10 to reach the insertion limit. The inner surface of the end tube 7 is substantially flush with the inner surface of the intermediate portion 4. A connecting tube 12 is inserted into the end tube 7, and the connecting tube 12
The tip reaches the middle part 4.

When regulating the shape, the sealing 9 of the grooved portion 8 is removed and the pipe joint is held. The pipe joint is rotatably held and consists of a rotation power source 15 and a rotation receiver 16.

The end tube 7 is held on the rotation power source 15 side, and the lid opening 3 is held by the rotation receiver 16.

In this state, the intermediate portion 4 is heated and softened by a heat source 17, such as a far-infrared rod heater, to cause the intermediate portion 4 to contract in diameter.

Next, the pipe joint is removed and moved to the core 13. The core 13 has a size and shape that matches the regular inner surface size and shape of the intermediate portion 4. The core 13 is inserted from the end pipe 7 side of the pipe joint and pressed by the press plate 19 to bring the core 13 into contact with the intermediate part 4 to regulate the inner dimensions and shape of the intermediate part 4. Next, the pipe joint body is cooled. and solidified. Cooling may be performed by natural cooling or forced cooling using water or cold air. After cooling, the press plate 19 is separated and the punching plate 20 attached to the core 13 is pushed up to remove the pipe joint from the core 13. Then, put the puffing 9 on the grooved part 8 again.
Insert it into the holder and use it.

(Function) The intermediate portion 4 of the pipe joint body 1 may have an uneven amount 14 on its inner surface depending on molding conditions, particularly thermal conditions during diameter expansion. In such a case, even if the tip of the connecting tube 12 reaches the intermediate portion 4 and an attempt is made to adjust the insertion depth, the insertion depth of the connecting tube 12 cannot be adjusted because of the unevenness 14. In addition, pipe joints that are currently used for running water piping, etc., have strict dimensional and shape requirements, but if an unevenness amount of 14 occurs, the dimensional and shape requirements may not be met.

Therefore, in the present invention, the intermediate portion 4 of the pipe joint having the above-mentioned defect is
The core 13 is heated and softened, making use of the diameter reduction during softening.
The shape is regulated by

To control the shape, the puffing 9 of the grooved portion 8 is removed, and while the pipe joint is held, the intermediate portion 4 is heated and softened using a heat source 17, for example, a far-infrared cotton swab heater. When softened, the diameter of the intermediate portion 4 is reduced.

Next, the pipe joint is removed and moved to the core 13. The core 13 is mounted on a press plate 18, and the end tube 7
It is inserted from the side and comes into contact with the intermediate portion 4 in a reduced diameter state to regulate the intermediate portion 4 to a regular inner dimension and shape.

By cooling, the intermediate portion 4 is solidified in a state in which the internal dimensions and shape are regulated to be normal.

(Effects of the Invention) According to the present invention, the amount of unevenness of the intermediate portion 4 is 1 when manufacturing the pipe joint.
4, even if the pipe fitting does not conform to the regular dimensions and shape due to 4.
It becomes possible to obtain a pipe joint that conforms to the regular dimensions and shape, and it is possible to eliminate the uneconomical situation of not using it.

[Brief explanation of drawings]

Fig. 1 is a longitudinal sectional view showing an example of a pipe joint with unevenness in the intermediate portion, Fig. 2 is a longitudinal sectional view showing an example of a pipe joint in which the intermediate portion is heated by a heat source to cause diameter reduction, and Fig. 3 The figure is a longitudinal cross-sectional view showing a state in which the inner dimensions and shape of the intermediate portion are regulated by a core, and FIG. 1 Pipe joint body 3 Socket section 4 Intermediate section 5.10 Stepped section 6 Receiving section 7 End tube 8 Groove section 9 Rubber banking

Claims (1)

[Claims] A pipe joint main body 1 having a spout 3 formed at one end, an intermediate portion 4 formed by expanding the diameter by heat treatment, and a socket 6 formed by further expanding the diameter at the other end. In a pipe joint in which an end pipe 7 having a groove-shaped part 8 into which a packing 9 is fitted is formed at one open end and is inserted into a socket part 6 and bonded, the intermediate part 4 is heated by a heat source 17. After heating and reducing the diameter of the intermediate portion 4, the core 13, which has an outer surface size and shape that matches the regular inner surface size and shape of the intermediate portion 4 and is attached to a press plate 18, is placed on the end pipe 7 side of the pipe joint. A method for regulating the shape of a pipe joint, which comprises inserting and pressing the core 13 into contact with the intermediate part 4 to regulate the inner dimensions and shape of the intermediate part 4, and removing the pipe joint from the core 13 after cooling. .