JPS6316486Y2 - - Google Patents

Description

[Detailed description of the invention] This invention relates to a resin tube centrifugal molding device.
Here, the resin pipe includes only resin, a resin with reinforcing fibers mixed in, a resin with aggregate such as sand mixed in, or a combination of these.

FIG. 1 shows a conventional general resin tube centrifugal molding apparatus. That is, 1 is a cylindrical mold, which is supported by a plurality of wheels 2 and is rotatable around a horizontal axis 3. Ring bodies 4 are fitted into both ends of the mold 1, and a molding surface 5 is formed between these ring bodies 4. A resin supply shaft 7 supported by a trolley 6 can be inserted into the mold 1, and by supplying resin from its tip, a resin tube 8 is centrifugally molded on the molding surface 5. When the resin tube 8 is centrifugally molded using such a resin tube centrifugal molding apparatus, burrs 9 are generated so as to be located on the ring body 4 . This is because, when the cart 6 is moved and stacked,
Since the carriage 6 inevitably moves in the direction of the horizontal axis 3, if resin is introduced in this state, a small amount of resin will be supplied onto the ring body 4 at the end of its movement. That is, in FIG. 2, the actual length to be formed is l, but Δl always occurs at both ends. No matter how the resin is introduced, for example, even if the speed of the cart is kept constant and the resin is added instantaneously, the resin will be introduced in a chevron-shaped manner.In other words, since the cart 6 is moving, the resin will be introduced in a trapezoidal manner. Therefore, the area indicated by the diagonal line a becomes the burr 9. Conversely, if l is set outside of Δl, both ends of the resin tube 8 will be thin. In order to make this wall thickness constant, the portion indicated by the diagonal line a is necessary, although the burr 9 is generated as described above.

The present invention proposes a resin tube centrifugal molding device that does not generate burrs and can produce resin tubes with uniform wall thickness.One embodiment of the device will be described below with reference to FIGS. 3 and 4. .

In FIG. 3, reference numeral 10 denotes an annular member that can be folded in half, and its proximal end 10a is attached to the inner surface of the ring body 4, and its free end side 10b is located at a position where it fits inside the ring body 4 and at a position opposite to the molding surface 5. It is constructed so that it can be bent and moved.

As shown in FIG. 3, the free end side 10b is bent into the ring body 4 and the desired centrifugal molding is performed with the free end side 10b stacked on the base end side 10a. At this time, a portion of the resin 11 transfers onto the free end side 10b while causing a thickening phenomenon, and a V-shaped valley 12 is generated inside the free end side 10b.
After performing a predetermined centrifugal molding on the resin, the free end side 10b is placed on the molding surface 5 as shown in FIG.
Fold to the side. This causes part of the resin 11 to become trough 12.
pushed into.

By changing the shape of the annular member 10, the ends of the resin tube 8 can be formed into both tapered surfaces when folded back as shown in FIGS. 5 and 6.

As described above, according to the present invention, after performing centrifugal forming, the proximal end of the annular member is folded back to the forming surface side for final forming, thereby preventing the occurrence of burrs and achieving uniform thickness. A thick resin tube can be obtained.

[Brief explanation of drawings]

Fig. 1 is a longitudinal sectional front view showing a general example, Fig. 2 is an explanatory drawing, Figs. 3 and 4 are longitudinal sectional front views of main parts showing an embodiment of the present invention, and Figs. 5 and 6 are FIG. 7 is a longitudinal sectional front view of main parts showing another embodiment. 1...Mold, 2...Ring body, 3...Horizontal axis, 4
...Ring body, 5...Molding surface, 6...Dolly, 7...
... Resin supply shaft, 8 ... Resin pipe, 9 ... Burr, 10
...Annular member, 10a...proximal end side, 10b...distal end side, 11...part, 12...valley.

Claims (1)

[Scope of utility model registration request] A ring body is fitted and attached to both ends of a mold that is rotatable around a horizontal axis, a molding surface is formed between these ring bodies, and an annular shape is formed on the inner peripheral surface of the ring body or the end surface on the molding surface side of the ring body. Attach the proximal end of the member,
A resin pipe centrifugal molding apparatus characterized in that the free end side of the annular member is configured to be bendable between a position on the inner circumferential surface of the ring body and a position facing the molding surface.