JPS5833436B2 - Socket pipe forming method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an injection molded socket of thermoplastic, flexible material having a groove for receiving a ring-shaped portion of a plastic socket pipe, preferably a seal, and a head portion extending radially into the groove. Concerning a method of forming a pipe.

Injection molded socket pipes of thermoplastic material of this type are known.

In the case of such well-known injection molded socket pipes,
The groove is formed by axially expanding the head portion and then narrowing to form the desired injection molded socket pipe.

However, such known injection-molded socket pipes require complex equipment and are considerably time-consuming and cumbersome to manufacture, as various mechanical parts must be used to obtain the desired narrowing. It has the disadvantage of being

Another disadvantage of this known injection molded socket pipe is that the free end of the head section extends axially.
This end part of the axially extending head part is liable to break when it falls freely on its side, so that the socket pipe is often no longer usable.

This is also the case when certain thermoplastic materials fall, causing cracks to occur precisely in the outermost radially extending portion of the groove.

It is an object of the invention to form a socket pipe of thermoplastic material of the type mentioned above, which does not have these disadvantages, is easy to manufacture and without the risk of breaking the axial extension of the head part. The goal is to provide a method to do so.

A socket pipe of thermoplastic material formed according to the present invention has a groove for receiving a ring-shaped portion of the sealing body;
The groove has a radially extending head portion and includes a recess extending into a thick-walled portion disposed at the end of the socket, the thick-walled portion having an inner surface of the socket and an outer surface of the socket. and the portion of the socket extending inwardly from the groove has a larger inside diameter than the other portion of the socket.

In such socket pipes, the ring-shaped part of the seal is easily maintained in the groove.

Preferably, the head portion is integral with the socket pipe.

In such a socket pipe, preferably obtained by injection molding, the groove can be formed very easily by radial deformation of the head part.

This is because the recess automatically forms a part for holding the ring-shaped part of the seal so that the seal cannot be easily pulled out of the groove when subjected to tension.

Moreover, when deforming the head part, it is only necessary to deform it in the radial direction, and there is no longer any need to narrow this head part.

Socket pipes can be manufactured very easily using very simple equipment.

A particular advantage is that, since the free end portion of the head section extends radially, the axially extending end portion of the head section will not be damaged in the event of a fall.

Another advantage of the method of forming a plastic socket pipe according to the invention is that the ring-shaped part of the seal can be accommodated in the groove during manufacture.

It is advantageous for the recess to have rounded edges in the thick-walled section, which makes it possible to produce a plastic socket pipe with good strength properties.

Preferably, the radially extending head portion is formed to extend inwardly (this completely prevents the ring-shaped portion of the seal from being pulled out when subjected to tension). Can manufacture socket pipes.

A method of forming a plastic socket pipe of thermoplastic material having an internal groove receiving a ring-shaped portion of a seal and having a radially extending head portion, the socket pipe being disposed at the end of the socket. a radially extending head portion comprising a recess extending in a thick-walled portion extending between the inner and outer surfaces of the socket, the portion of the socket extending inwardly from the groove having a larger inner diameter than other portions of the socket; Be formed with the following.

Preferably, the head portion integral with the socket type is plasticized and radially deformed.

Such a method can be easily implemented.

This is because only the head part that is integral with the socket needs to be radially deformed, and this can be easily done by plasticizing the head part and pressing it inward.

Preferably, the free end of the head portion is deformed in such a way that it ultimately extends radially after deformation.

If desired, the free end of the head portion may be deformed radially and inwardly.

In this way, the ring-shaped part of the seal can be configured to hold well and securely in the groove.

Next, the present invention will be described in detail with regard to embodiments of the present invention based on the accompanying drawings.

FIG. 1 shows a double socket 1 extruded from a thermoplastic material such as polyvinyl chloride.

This socket 1 has socket parts 2a at both ends, and an internal stop flange 16 between them.

In the groove 3 a ring-shaped part 4 of the sealing body 18 is arranged.

This ring-shaped part 4 is integral with the sealing sleeve 5.

In addition to the groove, the socket end 2 has a larger inner diameter than the socket part 2a.

The socket end 2 accommodates the sleeve 5 of the seal 18 when the male pipe part 21 is pushed into the socket part 2a.

The sleeve 5 slightly engages the male pipe section 21.

On the other hand, the outer diameter of the male pipe section 21 is preferably substantially equal to the inner diameter of the socket section 2a having the inner wall 17.

The groove 3 for receiving the ring-shaped part 4 is provided with a recess 6 arranged in the thick-walled part 7 of the socket end 2.

This thick-walled section 7 extends between the inner wall 8 of the socket end and the outer wall 9 of the head section 10.
extends beyond the free end 11 of the socket end 2.

The recess 6 in the thick-walled part 7 is provided with rounded edges.

To form the groove, the end portion 19 of the head portion 10 is
The end portions of the head portion 10 are radially deformed such that they extend radially, preferably ultimately radially.

In order to obtain good strength properties, when deforming the end part 11 a good radius 12 is added to the outside of the transition between the head part 100 radially deformed end part 19 and the outer wall part 9 of the final socket pipe. Take care to ensure that it is formed.

Advantageously, the head end 15 of the end section 19 of the head part 10 is deformed slightly inwards.

In this way, the free end 11 of the socket and the head part 100
The opening 13 between the radially deformed end portion 19 and the end 15 may be reduced so that the ring-shaped portion 4 of the sealing body 18 cannot be pulled out when subjected to a tensile force.

To make an injection molded pipe according to the invention, a socket pipe is injection molded.

The socket pipe is then partially heated, for example with hot air or with oil or with ultrasonic vibrations, such that at least a part of the head part 10 is brought to a temperature at which this part can be deformed.

In the case of polyelectrovinyl, this temperature is, for example, 120°C.
and 200°C.

When heating the head section 10, it is advisable to do this very quickly in order to maximize productivity.

The tool used to deform the head part 10, in the form of a ball-shaped die, preferably has an elevated temperature of, for example, 50° C. or more, in order to avoid brittleness of the radially deformed head part. I have to.

The brittleness of the radially deformed head section has a very detrimental effect on the strength properties.

When heating the head part so that it is deformed in the radial direction,
To ensure that the strength properties of the final product are the best possible.
Care should be taken to ensure that the head section 10 is heated so that the entire head section is at the desired plasticizing temperature.

It is advantageous to place the ring-shaped part 4 of the sealing body 18 in the recess 6 before deforming the head part 10, after which the desired fixation of this ring-shaped part 4 is effected by radial deformation of the end part 190 of the head part 10. be able to.

The present invention has the particular advantage that a simple injection mold can be used to form a starting product, from which an injection molded socket pipe can be formed by applying very simple tooling. can get.

When deforming the end portion 19 of the head portion 1'0, a radius 14 may be formed inside the transition between the deformed portion of the head portion 10 and the other undeformed portion of the head portion 10.

FIG. 4 shows the pipe 20 provided with the socket 2 and the male pipe section 21.

In this embodiment, the end portion 19 of the head portion 10 extends substantially radially after deformation.

The ring-shaped part 4 is held in the groove by virtue of the recess 6.

Preferably, this recess 6 extends substantially axially.

[Brief explanation of drawings]

FIG. 1 of the accompanying drawings is a longitudinal cross-sectional view of a plastic socket obtained by the forming method according to the present invention, FIG. Figure 4 shows the same part of the end of an injection molded socket pipe after radially deforming the head part and inwardly deforming the radially deformed head part; FIG. FIG. 2 is a view showing the same portion of the end of the socket pipe after deformation as shown in FIG. 2 together with the male pipe portion; 1...Double socket, 2...Socket end, 2a...Socket part, 3...
Groove, 4...Ring-shaped part, 5...Sealing sleeve, 6...Recess, 7...Thick-walled part, 8... Internal wall, 9...External wall, 1
0...Head part, 11...Free end,
12...Rounded portion, 13...Opening, 14
......Rounded part, 1 end, 16...Internal stop flange, 5...Head 17...Inner wall, 18...Sealing Body, 19...End part 1, Kuiburi 1,,,,,,,,,Kumebuki R20・
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Claims (1)

Claims: 1. A method of forming a socket pipe of plastic material having an internal groove including a radially extending head portion and adapted to receive a ring-shaped portion of a sealing body, comprising:
The ring-shaped head 4 of the seal 18 is partially accommodated within the recess 6 of the axially extending tip, and then the accommodated head 4
characterized in that the end 19 of the head part extending beyond the area of the head part is plasticized and bent inwardly around said head 4 until said end extends at least radially by means of a tool. How to form a socket pipe. 2. The method according to claim 1, wherein the recess 6 at the tip of the thick-walled portion 7 has a rounded edge. 3. The radially deformed end 19 is rounded in the region 12 where the radially deformed end 19 of the head part merges into the radially undeformed end. The method described in section. 4. Final end 15 of said radially deformed end 19
2. A method as claimed in claim 1, wherein the final end is deformed so that it extends substantially radially. 5. The method of claim 1, wherein the final end 15 is further deformed on its outer side. 6 the ring-shaped head 4 of said seal 18 extends further inwardly from the groove 3 and the other inner part 17 of the socket;
2. A method as claimed in claim 1, in which the sealing sleeve 5 is integrated with a sealing sleeve 5 which can be accommodated in the part 8 of the socket having a larger inner diameter.