JPH0780207B2 - Method and apparatus for manufacturing non-ceramic insulator - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for manufacturing a non-ceramic insulator for insulation which is used for supporting electric wires and has a cap.

[0002]

2. Description of the Related Art Conventionally, a core of a non-ceramic insulator is made of FRP (fiber reinforced plastic), and a rubber sheath is coated on the outer periphery of the core to form a coated core. A plurality of separately molded caps are bonded and fixed to the outer periphery of the coated core with an adhesive at predetermined intervals.

[0003]

However, this technique includes a step of forming a sheath on a core, a step of forming individual shades, and a joining step of joining them with an adhesive, and has a shade. Each process was indispensable to manufacture a non-ceramic insulator. In addition, the coated core obtained in each molding step and the plurality of shades must be bonded with an adhesive, which is troublesome in work and causes an increase in manufacturing cost.

The present invention has been made in view of the above-mentioned conventional problems, and an object thereof is to simplify the process for manufacturing a non-ceramic insulator, simplify the apparatus, reduce the size, and eventually the manufacturing cost. It is an object of the present invention to provide a method and an apparatus for manufacturing a non-ceramic insulator in which the use of an adhesive can be omitted, and the work can be facilitated while reducing the occurrence of the above.

[0005]

To achieve the above object, in the first invention, a sheath forming step of forming a rubber sheath on the outer periphery of a core made of a reinforced resin, and a core covered with the sheath. On the other hand, the gist is a method of manufacturing a non-ceramic insulator, which comprises a cap forming step of simultaneously forming a plurality of caps at a predetermined interval directly by an injection molding method.

According to the second aspect of the present invention, the insert support portion for arranging the core coated with the rubber sheath and the outer periphery of the core coated with the sheath are formed with a predetermined interval to form a shade. The gist is an apparatus for manufacturing a non-ceramic insulator including a plurality of cavities and a gate for injecting a rubber material into the plurality of cavities.

[0007]

In the first aspect of the present invention, in the sheath forming step, the outer periphery of the core made of reinforced resin is covered with the rubber sheath by, for example, extrusion molding. In the shade forming step, a plurality of shades are simultaneously formed on the sheath-covered core formed in the sheath forming step by an injection molding method at predetermined intervals.

In the second invention, after the core covered with the sheath is arranged on the insert supporting portion, the rubber material is injected from the gate into the plurality of shade forming cavities. Then, a plurality of shades are simultaneously molded at a predetermined interval with respect to the sheath-covered core.

[0009]

An embodiment embodying the present invention will be described below with reference to FIGS. FIG. 1 is a cross-sectional view of a mold-splitting surface of a mold 1. As shown in this figure, a plurality of independent cavities 3 for molding a shade by the mold 1 are provided. The cavity 3 is partitioned by the insert support portion 4 on the mold splitting surface. The mold 1 is configured by dividing the molds 2a to 2e into a plurality of molds at the positions of the cavities 3 for molding the shades 8 and fastening them with bolts (not shown). A gate 5 is communicated with the cavity 3 so that a rubber material can be injected into the cavity 3 through the gate 5.

As shown in FIG. 2, a screw extrusion unit 10 for extruding a rubber material is connected to the crosshead 9 of the extruder. Then, in the crosshead 9, the FRP core 6a having a round bar shape is introduced, and the rubber material is extruded from the screw extruding portion 10. Then, the sheath 7 is formed on the outer periphery of the core 6a by coating, and the sheath 6 is formed by being heated in the heating chamber-11.

Next, a method for manufacturing a non-ceramic insulator using the mold 1 constructed as described above will be described. First, in the sheath molding step of molding the coated core 6, in the case of the extrusion molding method, as shown in FIG. 2, the core 6a having the sheath 7 coated portion with a primer is introduced into the crosshead 9 in advance. On the other hand, the screw extrusion unit 10
Then, a compound obtained by blending EPDM (ethylene-propylene-diene copolymer rubber) or silicone rubber with a compounding agent such as a vulcanizing agent and a filler is extruded onto the crosshead 9. In the crosshead 9, the outer periphery of the core 6a is extruded so as to be covered with a rubber material, passes through the heating chamber 11, and is drawn out to the outside.

At this time, the rubber material is molded, is vulcanized and adhered to the core 6a, and the sheath 7 is firmly adhered and joined to the core 6a by the action of the primer applied to the core 6a. In this manner, as shown in FIG. 3, the sheath 7 is formed on the outer periphery of the core 6a by coating to form the coated core 6. Then, only the portions of the sheath 7 not coated with the primer (the portions indicated by alternate long and two short dashes lines in FIG. 3) are cut off at both ends of the coating core 6 having the predetermined length.

Next, as shown in FIG. 4, in the step of forming the shade 8, the coated core 6 thus obtained is supported by the insert support portion 4 in the mold 1. In this state, when the same rubber material used to mold the sheath 7 is injected from the gate 5, the rubber material is injected into the plurality of cavities 3 to form a plurality of caps 8, four caps 8 in this embodiment at the same time. It At this time, the rubber material is molded and also vulcanized and adhered to the sheath 7. In this way, a plurality of shades 8
Can be simultaneously and easily molded.

The rubber material and the shade 8 forming the sheath 7 described above.
Since they are the same as the rubber material that forms the rubber, they have a good affinity with each other, and therefore, the two are surely intimately bonded and strongly bonded at the boundary surface without using a special adhesive. Since this vulcanization bonding does not use the conventionally used adhesive as described above, it does not involve foreign substances and has a high bonding strength.
Are integrally formed with the sheath 7. Therefore, the sheath 7 and the shade 8
There is no possibility that water will infiltrate into the interface with and damage the insulation.

As described above, in this embodiment, the conventional step of separately forming the shade 8 and the covering core 6 for covering the shade 8 are performed.
The shade 8 can be joined to the coated core 6 at the same time when the shade 8 is formed without requiring the two steps of joining to the shade 8. Therefore, the process for manufacturing the non-ceramic insulator can be simplified, and
The apparatus can be simplified and downsized, and the manufacturing cost can be reduced. In addition, it is possible to omit the use of an adhesive that has been required to be used conventionally, and the work becomes easy.

The present invention is not limited to the above-mentioned embodiments, but may be embodied with the following modifications, for example, without departing from the spirit of the invention. (B) As shown in FIG. 5, when manufacturing a long product, a group (four in FIG. 5) of caps 8 is formed on the same coated core 6, and thereafter, the position is changed and the same operation as described above is performed. Repeat
Form a plurality of (8 in FIG. 5) shades 8. (B) The number of cavities 3 in the mold 1 is set to 2, 3 or 5 or more depending on the desired number of shades 8 and the number of molding operations. (C) Changing the intervals between the cavities 3
Change the size and shape of the.

[0017]

As described above in detail, according to the first aspect of the invention, the process for manufacturing the non-ceramic insulator can be simplified, and the use of an adhesive can be omitted, which makes the work easy. Produce an effect.

Further, according to the second invention, there is an excellent effect that the apparatus can be simplified and miniaturized, and further, the manufacturing cost can be reduced.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a mold for manufacturing a non-ceramic insulator showing an embodiment of the present invention.

FIG. 2 is a front view showing a crosshead of an extruder.

FIG. 3 is a front view showing a sheath-coated core.

FIG. 4 is a sectional view of a mold showing an operation of the embodiment.

FIG. 5 is a sectional view of a mold showing an operation of another example of the present invention.

[Explanation of symbols]

3 ... Cavity, 4 ... Insert support part, 5 ... Gate,
6 ... Coated core, 6a ... Core, 7 ... Sheath, 8 ... Shade.

Claims (2)

[Claims] 1. A sheath forming step of forming a rubber sheath on an outer periphery of a core made of a reinforced resin, and a plurality of shades are directly formed on the core covered with the sheath at predetermined intervals by an injection molding method. A method for manufacturing a non-ceramic insulator, which comprises a cap forming step of forming at the same time. 2. An insert support part for arranging a core covered with a rubber sheath, and a plurality of cavities for molding a shade at predetermined intervals on the outer periphery of the core covered with the sheath, An apparatus for manufacturing a non-ceramic insulator, comprising: a gate for injecting a rubber material into the plurality of cavities.