JPS5837124B2 - Gooseijiyushikanno Ukeguchibuseikeihouhou - Google Patents

Description

[Detailed Description of the Invention] The present invention involves inserting a mold into the end of a synthetic resin pipe or fixing a mold and applying the mold to the end of the pipe so as to cover the resin pipe. Regarding the method of molding the socket part, in particular, a ring that fills the void formed at the back of the socket pipe is fitted in advance into a mold, and this ring is supported by the mold in a centrifugal direction. This invention relates to a method of molding a socket part in which a ring is molded while floating in a mold and being held concentrically.

Conventionally, it is well known to form a socket part on a pipe molded from a synthetic resin material, and this socket molding can also be done by injection molding methods such as short pipes, primary molding by filament winding method, or by pre-molding pipes. There is secondary molding, which is applied after manufacturing.

The method of the present invention is applied to primary molding and secondary molding, and since it is often applied particularly to secondary molding, the following description will be directed to secondary molding.

Generally, in a pipe joint, as shown in Fig. 1, the end of one pipe 1 is expanded to form a socket part 3, and the end of the other insertion pipe 2 is inserted into the socket part and is inserted into the socket part 3. An adhesive or filler bonding agent is applied to bond.

The conveyed substance then flows from the pipe 2 towards the receiving pipe 1.

However, if the inner surface of the pipe joint is not uniformly flat, the flow resistance will increase, or the transported substances may be retained due to turbulence, and a void as shown by 4 in FIG. 1 will be created in the joint.

This space 4 can be formed by making the end of the insertion tube 2 thinner so as to fit the enlarged socket, but this is extremely difficult in practice, and there is a risk of breakage and deformation, making it difficult to put it to practical use.

Of course, if the pipe joint socket is primary molded, a joint step part will be formed that corresponds to the wall thickness of the insertion tube, but secondary molding requires the use of a special mold, resulting in an extremely expensive pipe joint part. It's not practical.

In addition, the socket pipe may be damaged by inserting the fitting or part without considering the insertion allowance.

Therefore, in order to fill the void 4 as shown in FIG. 1 and also restrict the insertion length of the insertion tube 2, a ring 5 that fits the void 4 as shown in FIG. 2 is used.

This ring 5 is hereinafter referred to as a filling ring, but as shown in the cross section in Fig. 3, this ring is relatively thin and easily deformed, and even if it is installed after molding the socket, it will not be used in anything other than large-diameter pipes. This is impossible, and even if it is installed, there is a risk that it will fall off during transportation or joining work.

Therefore, it is desirable to shape the receptacle and at the same time accurately position the filling ring 5 at the appropriate location.

For this purpose, for example, as shown in FIG. 4, the end of the tube 1 that forms the socket is softened by heat treatment, or an insertion mold called a tampin 6 is applied to the tube end during the softening treatment. When forming the socket part 3, a stepped part 7 (see Fig. 5) is formed on the tamping pin 6, the filling ring 5 is fitted into this part in advance, and applied to the pipe 1, and after cooling and solidifying, the tamping pin 6 is extracted. A means was used to leave only the filling ring 5 in the fitting part.

That is, as shown in FIG. 4, the tamping pin 6 has a protrusion 6C shaped at its rear edge for adjusting insertion, and its tip 6' has an inclined surface with a small diameter, and a socket in the middle. A large diameter part equal to the inner diameter and a small diameter part equal to the inner diameter of the connecting pipe are connected by an inclined surface, a stepped part as described above is formed in the middle, the filling ring 5 is fitted, and the tampin 6 is It was applied to the end of the tube 1 as shown in FIG.

When the tampin 6 is cooled after insertion and pulled out from the tube 1 as shown in FIG. 5, a socket 3 is formed at the end of the tube and at the same time a filling ring 5 is left in the fitting portion.

However, the filling ring 5 is relatively thin as shown in FIG. 3, and strong resin materials or metal materials suitable for other filling rings are sometimes used, and these materials have the same thermal expansion and resistance as pipe materials. It often has no shrinkage rate.

Therefore, even if the filling ring 5 is placed in the matching area using the tamping pin 6, it may come off when the tamping pin 6 is removed, or even if it is left behind, it may become displaced or fall off due to the passage of time or a slight impact. Ta.

Further, when inserting the filling ring 5 into the tongue pin 6, the inner diameter of the filling ring 5 is formed to be very slightly larger than the outer diameter of the fitting portion so that the filling ring 5 can be easily fitted.

This degree is determined by considering the heat shrinkage rate of the material of the filling ring 5, but it is difficult to maintain concentricity with the filler ring 5 made of a material with a high heat shrinkage rate. was difficult.

The present invention has been made with attention to these circumstances, and the tamper pin 6 is provided with a centrifugally biasing holding device for the filling ring 5.
When fitting the filling ring 5 to the tampin 6, the outer diameter of the fitting part is reduced to make fitting the ring 5 extremely easy.After fitting, the filling ring 5 is attached to the sliding member and the outer periphery of the member. The pipe socket part 3 is formed by biasing each other in the centrifugal direction with a ring spring and holding them so as to float above the fitting body part.
When the mold device is taken out, the centrifugal bias is released and the fitting body is made to have a reduced diameter so that the filling ring 5 is reliably left in the fitting position of the socket 3. .

Hereinafter, a case will be described in which the present invention is implemented based on the apparatus illustrated in the drawings, but changes in design in accordance with the above-mentioned and later-described purposes are included within the technical scope of the present invention.

6 and 7 show a structure in which the filling ring 5 is biased and held by a sliding member in the axial direction of the mold and a ring spring around the outer periphery of the member.

In these drawings, FIG. 6 is an example of an apparatus for carrying out the present invention, and the figure shows the upper half in a central section and the lower part in a side view.
Its configuration is expanded and shown in FIG.

That is, the insertion mold 8 has a protruding edge 8b formed thereon as in the above example, and a protrusion 8a on the tip side.
As in the previous example, there are notch grooves 25, 25...
will be established.

Thus, a sliding tube 20 is slidably fitted into the protrusion 8a, and a beak portion having an inclined surface 21 is formed on the mold side of the sliding tube 20.

Furthermore, a groove 18 is formed inside the stepped portion of the mold 8 in which the beak portion of the sliding tube 20 is accommodated.

A branched arm rod 24 is fixed to the inside of the sliding tube 20 by welding or screwing, and the arm rod 24 has cutout grooves 25, 25, . . . formed in the protrusion 8a of the mold 8. ...slides inside.

A ring spring 22 is placed under tension on the sloped surface of the beak portion of the sliding tube 20, and the other surface of the ring spring 22 is brought into contact with the step surface 27.

There is no particular restriction on the material of the ring spring 22, and the wire diameter, spring pinch, etc. may be set arbitrarily.

The filling ring 5 is thus located outside the ring spring 22.

Reference numeral 19 denotes a lid body, the tip of which has a small diameter to form an inclined surface as in the previous example, and a bolt 26 is attached to the front surface of the protrusion 8a of the mold.
Support with.

Further, a shaft 23 is threaded onto the arm rod 24, and the shaft 23 is pivotally supported at the center of the mold 8 and the center hole of the lid body 19.

The shaft 23 itself is provided to be slidable or rotatable, and the arm rod 24 is slid along the inside of the notched groove 25, and the sliding tube 20 is rotated based on this. Slide it in the direction of the mold axis.

Therefore, the ring spring 22 located at the beak of the sliding tube 20 expands in the diametrical direction on the inclined surface 21 or contracts in the diametrical direction to easily and uniformly bias and hold the filling ring 5 in the centrifugal direction. Or open it.

That is, when the sliding tube 20 slides toward the mold 8 side, the outer circumferential diameter of the ring spring 22 is expanded to hold the filling ring 5 so that it is easily and uniformly lifted from the mold in the circumferential direction. When sliding to the opposite side, the outer peripheral diameter of the ring spring 22 is reduced to allow the filling ring 5 to open easily and uniformly in the circumferential direction.

Although not shown, the sliding movement of the sliding tube 20 is not limited to the arm rod 24, but may be connected to a cylinder piston provided in the mold 8, or a cylinder may be provided directly within the lid 19, and the sliding movement of the sliding tube 20 may be directly connected to the cylinder piston provided within the mold 8. The design can be easily changed by moving the sliding tube 20, etc.

As described above, when forming a socket at the end of a resin pipe, the present invention uses an insertion mold that is applied to push and spread the pipe end.
The filling ring 5 is easily and uniformly biased and held in the centrifugal direction via the ring spring 22, and the filling ring 5 is configured so that its maximum outer diameter portion slightly protrudes from the outer periphery of the body of the mold 8. Further, the narrow diameter portion at the tip of the filling ring 5 is held floating on the outer periphery of the sliding tube 2o, thereby ensuring secure connection with the pipe wall.

Further, as described above, the filling ring is easily and uniformly biased and held from the mold 8 in the circumferential direction by the ring elastic action of the ring spring 22, and is applied to the tube end. If a suction airflow is created in the mold 8 and the outer tube of the socket part 3 is brought into close contact with the mold 8, the inside of the tube will bulge out uniformly in the circumferential direction on both sides of the filling ring 5, and the tube will The concentric engagement with the meat can be further strengthened, and when the mold is pulled out, the centrifugal bias is uniformly released over the circumferential direction, so that the inner surface of the filling ring 5 and the mold holding surface This ensures that voids are created in the circumferential direction, making it easier to remove the mold even if the filling ring is compressed or slightly deformed after cooling, and the socket part can be molded more reliably. It has become possible to improve work efficiency and improve quality.

Although the embodiment described secondary molding of the socket part, as mentioned at the beginning, it can also be used for primary molding, and the filling ring 5 is insert molded, and the core is provided with a centrifugal bias holding device as described above. If so, the filling ring can be stably held in the inner part of the socket pipe very easily.

[Brief explanation of drawings]

Figure 1 is an explanatory cross-sectional view of a pipe joint, Figure 2 is a cross-sectional view of a pipe joint to which a filling ring is applied, Figure 3 is a cross-sectional view of a filling ring, Figure 4 is an explanatory diagram of a conventional filling ring installation, and Figure 5 is a cross-sectional view of a pipe fitting to which a filling ring is applied. FIG. 4 is a progress explanatory diagram, and FIG. 6 is a side view of an insertion mold in which the present invention is implemented, with the upper half shown in cross section and a part broken away. FIG. 7 is a developed sketch showing the configuration of FIG. 6. 1... Tube, 2... Insertion tube, 3...
...Socket part, 4...Gap, 5...Filling ring, 6...Curved tampin, 7...Step part, 8...
...Insertion mold, 18...Curved groove, 19...
Lid body, 20... Sliding tube, 21... Inclined surface, 22... Ring spring, 24... Arm rod, 25... - Notch groove, 26... Bolt, 27... Step surface.

Claims (1)

[Claims] 1. In a method of forming a socket pipe part by pushing a mold into the end of a synthetic resin pipe, the mold includes a ring that fills the gap between the inner part of the expanded diameter socket and the tip of the insertion pipe. In addition to being fitted in advance, the ring is inserted into the inclined floor circumferential groove formed by the stepped surface on the leading end side of the mold and the outer peripheral side inclined surface of the sliding member provided so as to be slidable in the axial direction of the mold. A method for molding a socket part of a synthetic resin pipe, characterized in that the molding is carried out by directly biasing and holding in the centrifugal direction by a ring spring housed in between.