JPS6127703Y2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a synthetic resin pipe joint with an insert.

In order to reinforce the connecting portion of a synthetic resin pipe joint, it is common practice to embed a cylindrical insert made of metal or the like into the opening of the connecting portion by injection molding. As shown in Figure 2, the insert used in this case is one in which the surface of insert A in contact with the synthetic resin is knurled to create an uneven surface to prevent the insert from slipping out, to prevent it from rotating, and to make it adhere tightly to the synthetic resin. However, internal water may still seep out from the contact surface between the insert and the synthetic resin.

As a result of various studies in an attempt to resolve the above points, the inventor of this invention discovered that when the injection-molded resin contracts, the corners of the insert where the resin contacts act as fulcrums, creating stress that causes the resin to separate from the insert. I learned that when the insert warped, a small gap formed between the resin and the insert, causing water to seep out.

This invention was completed based on the above knowledge, and its gist is that in a synthetic resin pipe joint in which a cylindrical insert is embedded in the opening, the corners of the cylindrical insert in contact with the synthetic resin The present invention resides in a synthetic resin pipe joint with an insert, characterized in that at least a portion on the back side of the open end has a gently curved surface.

Next, this invention will be explained with reference to embodiments of the drawings.

Reference numeral 1 denotes a pipe joint body made of synthetic resin, and a cylindrical insert 2 is embedded in one opening 11 of the joint body. The other opening 12 of the pipe joint body is a pipe socket into which a synthetic resin pipe or the like is inserted and connected via an adhesive.

The insert 2 includes a part 21 that is embedded in the opening 11 of the pipe joint body 1 and a part 2 that has a male thread on the outer periphery.
It consists of 2. The central portion 211 of the embedded portion 21 in contact with the synthetic resin is knurled and has an uneven surface, and the corner portions 212 at both ends,
213 are each formed to have a gently curved surface with corners removed. In this embodiment, especially the rear corner 212 is formed to protrude into a tongue shape, which is preferable as it further improves the adhesion with the resin, but is not limited thereto. Further, although two grooves are formed on the outer periphery of the insert 2, this is not necessarily necessary. Furthermore, if the insert has a female thread, it goes without saying that the female thread may be carved on the inner periphery of the part to be embedded.

In this embodiment, the corner portion 21 in contact with the resin
Both corners 2 and 213 have gently curved surfaces, but at least the rear corner portion 212 may have a gently curved surface.

As described above, the synthetic resin pipe fitting with insert of this invention has a gently curved surface at least at the back side of the open end of the corner portion of the cylindrical insert that contacts the synthetic resin, so that when the resin contracts, The stress acts to press the resin against the curved surface, improving the adhesion between the resin and the insert, and as with conventional inserts with edged corners, this part acts as a fulcrum when the resin contracts, causing the resin to shrink. This eliminates the drawbacks of warping and creating gaps between the resin and the insert, and eliminates water seepage.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional front view of the upper half of an example of this invented synthetic resin pipe joint with an insert, and FIG. 2 is a longitudinal sectional front view of the upper half of a conventional one. 1... Pipe joint body, 2... Insert, 21
2,213...Corner corner.

Claims (1)

[Scope of utility model registration request] A synthetic resin pipe joint in which a cylindrical insert is embedded in the opening, characterized in that at least a portion of the corner of the cylindrical insert that is in contact with the synthetic resin and is further back than the opening end has a gently curved surface. Synthetic resin pipe fitting with insert.