JPS6145925B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a centrifugal mold that can easily demold a molded product (pipe). explain.

In FIG. 1, the area above the horizontal axis 1 shows the time of molding the socket part, and the part below shows the time of molding the whole. 2
is a cylindrical rotating body that can rotate around the horizontal axis 1 via a plurality of rolls 3, and its rotational driving force is applied from the rolls 3 side. Reference numeral 4 denotes a rubber mold that can be attached to the inner surface of the rotating body 2 and is made of soft rubber, silicone, urethane, etc., and has ring portions 5 and 6 extending outward at both ends thereof. Reference numerals 7 and 8 denote ring-shaped rubber presser jigs that are fitted into both ends of the rotating body 2, so that the outer and inner surfaces of the ring portions 5 and 6 as well as the rubber-shaped outer circumferential surface that follows the inner surfaces can come into contact with each other. . 9 and 10 are end face jigs attached to both ends of the rotating body 2, and the inner ends thereof have cylindrical parts 9A and 10A that can be fitted into the rubber mold 4, and flanges that can come into contact with the outer surfaces of the ring parts 5 and 6. Part 9B, 10
By integrating the flanges 9B, 10B and the rubber presser jigs 7, 8 with fixing devices 11, 12, the ring portions 5, 6 at both ends of the rubber mold 4 are placed on the rotating body 2 side. Fix it. Reference numeral 13 denotes a cylindrical socket inner surface molding die attached to the inside of the socket side end face jig 10, which can be oscillated between a position facing the socket molding surface 4a of the rubber mold 4 and a position accommodated within the socket side end face jig 10. It is possible to move. In other words, the socket inner surface mold 1
3 is made of the same rubber as the rubber mold 4, and normally swings to a position within the socket side end face jig 10 due to its own elasticity. Furthermore, an annular convex portion 14 is integrally formed on the molding surface 13a. Reference numeral 15 denotes a cylindrical operating tool that fits inside the socket side end jig 10 and is movable in one direction of the horizontal axis, and by protruding inwardly with respect to the socket side end jig 10, the socket inner surface molding is performed. The mold 13 is pushed back and swung to face the socket molding surface 4a. 16 is a rotary pushing device facing one end of the operating tool 15, which includes a cylinder 17;
It consists of an idling roll 18 which is attached to the piston rod and can come into contact with the one end. The inside of the body of the rubber mold 4 is formed into a hollow part 19, into which a liquid 2 such as soft oil or specific gravity additive oil is filled.
0 is injected. The hollow part 19 is formed to prevent liquid leakage, and since the hollow part 19 is annular, a connecting member 21 is used to connect the inner and outer cylinders to prevent the inner cylinder part of the rubber mold 4 from deforming downward due to its own weight. The hollow parts 19 are made of continuous foam. Cylindrical portion 9 of spigot side end jig 9
A tank chamber 22 is formed in A, and the tank chamber 22 and the hollow portion 19 communicate with each other via a plurality of passages 23. 24 indicates a liquid injection port.

In FIG. 1, the area above the horizontal axis 1 shows the state during molding of the socket. That is, the rubber mold 4 inserted into the rotating body 2 has its both end ring portions 5 and 6 fixed to the rotating body 2 side by rubber holding jigs 7 and 8 and end face jigs 9 and 10. And operation tool 1
5 has been moved outward, so that the socket inner surface molding die 13 is located within the socket side end face jig 10. In this state, while rotating the integrated two parts 2 and 4 around the horizontal axis 1, materials such as resin liquid, reinforcing fibers, and sand are supplied onto the socket molding surface 4a of the rubber mold 4, and the socket part 25a is Perform centrifugal molding. Next, the rotary pushing device 16 is activated, and the operating tool 15 is pushed in a predetermined amount via the moving idle roll 18. As a result of this pushing, the socket inner surface mold 13 is pushed back and swung, and is brought into contact with the inner surface of the socket part 25a as shown by the imaginary line. This abutment is a press molding in which the operating tool 15 is positioned inside the socket inner mold 13, and the annular convex portion 14 is pushed into it. As a result, the socket part 25
A circumferential groove 26 for fitting a seal ring can be formed on the inner surface of a. Next, material is supplied onto the inner surface of the rubber mold 4 from the spout molding part to the body molding part in the same manner as described above, and a tube (molded product) 25 is formed as shown below the horizontal axis 1. Perform centrifugal molding. When performing such centrifugal molding, the rotating body 2 and the rubber mold 4
Even if the molding inner surface of the rubber mold 4 is deformed (displaced) due to manufacturing errors or eccentricity, this is due to the action of the liquid 20 that has flowed into the hollow part 19 from the tank chamber 22 via the passage 23. It will become a perfect circle. After the centrifugally formed tube 25 has hardened, the rotating body 2 is stopped. First, the socket side end face jig 10 is removed. Then, as shown in FIG. 2, the bag 27 is positioned on the inner surface of the tube 25 on the outlet side.
This bag body 27 is attached to communicate with a pressure air supply pipe 28, and the pressure air supply pipe 28 is attached to a sealing lid 29 attached to an end face jig 9 on the insertion side, and an annular seal body 3
It passes through 0. Note that a main pressure air supply pipe 31 is attached to the sealing lid 29. Therefore, as described above, with the bag body 27 positioned on the inner surface of the outlet side of the tube 25, pressurized air is supplied through the supply pipe 28 to inflate the bag body 27 and bring it into pressure contact with the inner surface of the outlet side. . Then, pressurized air is supplied to the inside of the outlet side through the main supply pipe 31. Then, the pressure P ₁ expands the diameter of the inner cylindrical portion of the rubber mold 4, creating a gap 32 between the tube 25 and the outer peripheral surface. At this time, the liquid 20 in the hollow part 19 flows into the passage 23.
is returned to the tank chamber 22 through the The pressure P ₁ also acts on the bag body 27, and by setting the relationship with the internal pressure P ₂ of the bag body 27 as P ₁ < P ₂ , the internal pressure P ₂ causes the pipe 25 to flow through the bag body 27. An extrusion force acts on the Since the sliding force of the tube 25 is extremely reduced by the gap 32, the tube 25 is pulled out from the rubber mold 4 as the supply tube 28 is inserted. After the tube 25 is extracted, the bag body 27, the sealing lid 29, etc. are removed, so that the inner cylindrical portion of the rubber mold 4 is elastically restored, and the receptacle side end face jig 10 is attached, so that centrifugal molding can be started again.

In the above embodiment, the operation of demolding the tube 25 while leaving the rubber mold 4 on the rotary body 2 was described;
You may take out the rubber mold 4 from. That is, a rotating body 2 that can be divided into two in the circumferential direction is used, and this rotating body 2 is stopped when the tube 25 is uncured (semi-cured). Then, the rotating body 2 is divided and the tube 25 is taken out together with the rubber mold 4. At this time, the end face jigs 9 and 10 are also taken out together. After the tube 25 is cured, it is demolded in the same manner as described above, as shown in FIG.

The uncured tube 25 taken out may be formed into a curved tube, and after being cured, it may be removed from the mold in the same manner as described above. In addition, in the embodiment, the pipe 2 having the socket portion 25a
5 has been described above, but this also applies to those that do not have the socket portion 25a.

According to the present invention described above, even if the molded inner surface of the rubber mold is deformed (displaced) due to manufacturing errors or eccentricity of the rotating body or the rubber mold, this is due to the action of the liquid injected into the hollow part. Therefore, it can be made into a perfect circle, and a good molded product (tube) with a uniform thickness can always be obtained. By applying pressure to the inner periphery of the rubber mold and enlarging its diameter, a gap is created between it and the molded product, allowing the molded product to be easily removed from the mold with little sliding contact or resistance. This widening of the diameter can be easily done by allowing the fluid to flow into the tank chamber, and by returning the liquid in the tank chamber to the hollow part, centrifugal molding can be performed again. It is possible to eliminate the need for this and speed up the work.

[Brief explanation of the drawing]

Fig. 1 and Fig. 2 show one embodiment of the present invention, Fig. 1 is a longitudinal sectional front view during centrifugal molding, Fig. 2 is a longitudinal sectional front view during demolding, and Fig. 3 shows another embodiment. FIG. 3 is a longitudinal sectional front view when demolding. DESCRIPTION OF SYMBOLS 1...Horizontal axis, 2...Rotating body, 4...Rubber mold, 9, 10...End face jig, 13...Socket inner surface mold, 19...Hollow part, 20...Liquid, 22...
... Tank chamber, 23 ... Passage, 25 ... Pipe (molded product), 27 ... Bag body, 29 ... Airtight lid, 32 ...
〓 between.

Claims (1)

[Claims] 1. A rubber mold that can be placed on the inner circumferential surface of the rotating body is provided, a hollow part is formed in the body of the rubber mold, a tank chamber is provided that communicates with this hollow part, and liquid is supplied from these tank chambers to the hollow part. A centrifugal molding mold characterized by being injected with.