JPS6014570Y2 - Mold device for molding sockets of synthetic resin pipes - Google Patents

Description

[Detailed description of the invention] This invention is based on a tube connection section where another synthetic resin pipe is inserted into a pipe socket formed by expanding the diameter of a synthetic resin pipe, and a groove for inserting a rubber ring into the socket to seal between the two pipes. The present invention also relates to a mold device for forming a socket when the connecting portion has an undercut portion such as a tapered protrusion to allow slight bending freedom.

Generally, the work to expand the diameter of the socket uses a split core that has the inner surface shape of the socket and can be reduced in diameter, press-fits the heat-softened end of the synthetic resin pipe into the core, and then presses the heated and softened end of the synthetic resin pipe into the core. After cooling, the core is reduced in diameter and pulled out from the socket.

The purpose of the present invention is to propose a mold device for molding a socket of a synthetic resin pipe, which has a core whose diameter expands and contracts reliably and has a simple structure.

Examples of the present invention will be described below with reference to the drawings.

The end of the PVC pipe 1 is softened by heating and expanded into a socket shape with an annular groove 2 in which a rubber ring is attached to the end of the pipe, and a tapered protrusion 3 that gently slopes inward from the annular groove 2. do.

A guide fitting 5 inscribed in the PVC pipe 1 is fixed to the tip of the fixed shaft 4, and behind it a first slider 7 and a second slider 8, which are prevented from rotating by a keyway 6, slide in the axial direction. Possibly inserted.

A ring 10 is fixed with bolts 11 to the inner recess of the guide part 9 inscribed in the PVC pipe 1 of the guide fitting 5, and the front end of the first segment 13 is inserted into the four notches 12 provided at equal intervals in the ring 10. is pivotally connected with a pin 14, and a notch 12 is attached to the first slider 7.
A second segment 16 is pivotally connected to four axial grooves 15 provided at intermediate angular positions by pins 17.

The first and second segments 13 and 16 have a diameter-expanded position (Fig. 1) in contact with the inner surface of the socket 18 where the diameter is expanded, and a diameter-reduced position where they can rotate toward the center and escape from the socket 18. position (FIG. 2), in which the two segments 13, 16 alternately adjoin each other and form the molding core of the socket 18.

In the enlarged diameter position, both segments 13.16 support their rear end portions 19.20 on the slopes 21.22 of the advanced second slider 8 in order to withstand the contraction forces of the socket 1B.

The first segment 13 is also supported on the surface 23 of the first slider 7.

The first and second segments 13.1 in the expanded diameter position
The width of the surface 24 where the two segments 6 contact each other, that is, the width of the second segment 16 is slightly enlarged toward the center, so that the width can be reduced to the chain line position before the first segment 13.

Fixed shaft 4 for moving the first and second sliders 7.8
The frame 25 is slidably and non-rotatably guided and supported, a hydraulic cylinder 27 is installed between the bottom part 26 of the frame 25 and the second slider 8, and a rod 28 passing through the second slider 8 is used. The bottom portion 26 and the first slider 7 are connected, and a hydraulic cylinder 29 is provided between the frame 25 and a fixed member (not shown).

Next, the effect of this proposal will be explained.

Initially, the hydraulic cylinder 27.29 is extended, and the first and second sliders 7.8 adjoin each other and contact the guide fitting 5, as shown in FIG. 1, and the first and second segments 13.16 is in the expanded position.

After heating and softening the tip of the PVC pipe 1, when it is pushed along the guide part 9, the PVC pipe 1 expands in diameter along the outside of both segments 13 and 16, and by closing the outer mold 39, it becomes as shown in FIG. It takes the shape of the socket 18 shown in the figure and is then cooled and solidified.

Next, when the hydraulic cylinder 27 is shortened and the second slider 8 is retreated, the rear end portion 19 of the second segment 16 falls into the groove 31 along the slope 21 due to the tension of the spring 30, and the second segment 16 The protruding parts 32 and 33 of the socket 18
In addition, the first and second sliders 7.8 have difficulty with the distance a.

When the hydraulic cylinder 29 is then shortened, the eleventh and second sliders 7.8 are both pulled out of the socket 18 with a distance a, and the first segment 13 is moved by the pressure of the spring 34 so that the rear end portion 20 is moved into the first slider. 7 into the groove 36, and the protruding parts 37, 38 of the first segment can escape from the socket 18 (FIG. 2).

If the PVC pipe 1 is then pulled out, the work of forming the socket 18 is completed.

Note that the step 40 formed inside the rear end portion 19 of the second segment and the locking wall 41 at the front of the groove 31 are configured to engage with each other at a distance a, and the hydraulic cylinder 29 is omitted.
If the stroke of the hydraulic cylinder 27 is sufficiently long, the first and second sliders 7.8 can be pulled out at the same time with a distance a as described above by its shortening operation.

The present invention has the above configuration, and since the first and second segments forming the core rotate about their front ends as fulcrums, the rotation until the outer protruding part of the segment separates from the undercut part in the socket. The corners are small, so even if the undercut portion bulges out at almost right angles to the axis, the separation is easy, and the support structure of each segment is extremely simple, robust, and has few wear parts, making it easy to expand and contract. It is characterized by reliable and smooth radial movement.

[Brief explanation of drawings]

The drawings show one embodiment of the present invention, and FIG. 1 is a sectional view taken along the line A-A in FIG. 3 in the expanded diameter position, FIG. 2 is a sectional view similar to FIG. 1 in the reduced diameter position, and FIG. FIG. 2 is a side view taken along the line A-A in FIG. 1 showing the arrangement of the segments in the expanded diameter position. 4...Shaft, 5...Guide fitting, 7...
...first slider, death ...second slider,
13...First segment, 16...
Second segment, 18...Socket, 25-29
...Moving device, 32.33...Protruding part.

Claims (1)

[Scope of utility model registration request] a shaft, a guide fitting fixed to the front end of the shaft, and first and second sliders slidably guided and supported on the shaft in the longitudinal direction thereof;
First and second segments whose front ends are rotatably supported in the radial direction by the guide fitting and the first slider, respectively, and which are arranged alternately in the circumferential direction, and a moving device for the first and second sliders. The first segment is held in the expanded diameter position by the first slider at the forward end, and the second segment is held in the expanded diameter position by the second slider at the forward end, and the first and second segments are held in the expanded diameter position by the first slider at the forward end. The segments contact each other in the circumferential direction to form a core that matches the inner surface shape of the socket to be expanded in diameter, and by first retracting the second slider, the second segments A combination characterized in that the protruding portion of is rotated to a diameter-reduced position where it can escape from the socket, and the first segment is rotated to the diameter-reduced position by retreating the first slider after the rotation. Mold device for molding sockets of resin pipes.