JPH11306892A - Molding mold for silicone-coating of silicone bushing and insulator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a molding mold enabling production of a silicone bushing/ insulator having high adhesive power at joint portions and good electrical characteristics. SOLUTION: This molding mold is constituted of plural retainer plates 1-8 each of which forms one cap portion, and the retainer plate 8 is coated with fluoroplastic. The retainer plates 1-7 are applied with a molding lubricant, and a FRP tube 16 provided with aluminum flanges 17, 18 is set in the mold tool 11, then silicone is injected into the space to have the silicone bridged. A part of the FRP tube 16 is coated with the silicone, thereafter adhesive is applied to the potion 21 silicone is to be added, then the silicon is added by repeating the above molding procedure several times with the coating portion being moved. The retainer plate 8 forming the portion 21 the silicone is added is coated with the fluoroplastic rather than the molding lubricant, consequently adhesive power of the added portion 21 will not be lowered.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an insulator / insulator coated with silicone (hereinafter referred to as silicone insulator / insulator).
To a molding die used for the production of

[0002]

2. Description of the Related Art FIG. 6 is a view showing an example of a silicone porcelain tube. As shown in FIG. 5, the silicone porcelain is obtained by coating an FRP pipe 16 having aluminum flanges 17 and 18 attached to both ends thereof with silicone 20 as shown in FIG. 6, and the above silicone porcelain (or silicone insulator).
Is manufactured as follows. Aluminum flange 1 on both ends
Fix the FRP tube 16 in which 7, 18 are fixed with an adhesive or the like, or the FRP rod in which metal fittings are fixed to both ends with an adhesive in a molding die for coating with silicone, inject silicone, and heat and heat. Press. This causes a crosslinking reaction to form a crosslinked silicone. After that, the mold is opened and the silicone insulator tube / insulator is removed from the mold.

[0003] There is a method in which this series of molding procedures is performed in a single step, and a method in which molding is performed in a plurality of steps in order to manufacture a long insulator tube / insulator or to reduce the cost of a mold. In the former one-time molding, molding is performed using a mold having the same length as the molded body to be manufactured. In the latter multiple molding, a mold shorter than the molded product to be manufactured is used, and after molding a part, the molding procedure is repeated plural times while moving the molded part, and silicone is added. At this time, an adhesive or the like is applied to the surface of the silicone already added at the joint portion, and then the joint molding is performed. Regardless of the molding method used either once or multiple times, the silicone sticks to the mold and is difficult to release from the mold. Therefore, a mold release agent is applied to the mold to cope with the problem.

[0004]

When the above-mentioned molding method is used a plurality of times, a new silicone is coated on the existing silicone. At this time, the release agent applied to the mold is coated on the surface of the existing silicone. It has adhered, and the adhesive force at the interface with the newly covered silicone is reduced. If the adhesive force between the silicones is weak, moisture or the like intrudes from that portion, and the insulating property is reduced. SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a molding die capable of producing a silicone insulator tube / insulator having a high adhesive strength at a silicone seam and excellent electric characteristics. That is.

[0005]

In order to solve the above-mentioned problems, in the present invention, in a molding die for producing a silicone insulator / porcelain tube by molding a plurality of times, at least a portion of a silicone coating seam forming a seam is formed. A fluororesin coating is formed on the contacting surface. As described above, a fluororesin coating is formed on the part where the silicone coating seam of the molding die is formed so that molding can be performed without applying a release agent, thereby improving the adhesive force at the interface between silicone and silicone. I do. In addition, by forming the fluororesin coating only on the joint, an inexpensive molding die can be manufactured.

[0006]

1 and 2 are views for explaining a molding die according to an embodiment of the present invention and a method for manufacturing a silicone porcelain tube using the molding die. FIG. FIG. 2 shows a state in which an FRP tube having an aluminum flange is set in a mold for the first molding, and FIG. 2 shows a state in which the FRP tube is set in a mold for the second molding. 1A is a plan view and FIG. 1B is a side view. In the above description, the case where the silicone porcelain tube is manufactured by performing the molding process twice is described. However, in the case of performing the molding three or more times, the mold plate 1 in the first mold configuration is used.
By replacing the mold with the mold plate 9 and repeating the molding process a plurality of times, a silicone porcelain tube having a desired length can be manufactured.

1 and 2, aluminum flanges 17 and 18 are fixed on both sides of the FRP tube 16 with an adhesive or the like.
Is set in the mold 11 as shown in FIGS. As shown in FIGS. 1 and 2, the mold 11 has a plurality of mold plates 1 to 8 (FIG. 1),
The mold plates 1 to 8 and 9, 2 to 7, and 10 are fixed to a mold base (not shown) and integrated by bolts or the like. The mold 11 is divided into two parts (only one mold is shown in FIGS. 1 and 2 and the other mold has the same shape), and an FRP having aluminum flanges 17 and 18 is provided. After the tube 16 is set in one mold, the other mold is combined, and silicone is injected into the space 15 formed between the mold plates 1 to 8 and 9, 2 to 7, 10 and the FRP tube 16. Then, heat and pressure are applied to crosslink the silicone. To inject silicone into the mold,
The mold plate 4 is provided with a runner 14. The injection nozzle 12 is pressed against the mold plate 4, and silicone is injected into the space 15 from the flow channel 13 of the injection nozzle 12 through the runner 14 of the mold plate 4.

At the time of the first molding, mold plates 1 to 8 are used as shown in FIG. As shown in FIG. 3 (FIG. 3 (a) is a plan view and FIG. 3 (b) is a side view), a step A having a smaller diameter than the body size of the molded body is provided on the end template 8 forming the replenishing part. Is formed, and a fluororesin coating 22 is formed on the surface of the end template 8 which comes into contact with silicone. As shown in FIG. 1, a mold is formed using the mold plates 1 to 8, a release agent is applied to a surface of the molds 1 to 7 which comes into contact with the silicone, and the silicone is filled into the space 15 through the runner 14. And pressurized and heated. By this, FR
A portion of the P tube 16 is coated with silicone. At that time, since the step portion A is formed on the template 8 as described above,
The outer diameter of the silicone-coated addition portion 21 formed by the template 8 is smaller than the body size of the molded body. Further, since the end template 8 is coated with a fluororesin, the template 8 is easily released.

At the time of the second molding, a mold is formed by using the mold plates 9, 2 to 7, and 10, as shown in FIG. The template 9 is obtained by replacing the template 1 and the template 10 is replaced by the template 8
Is exchanged. A mold release agent is applied to the surfaces of the mold plates 9, 2 to 7, and 10 that come into contact with the silicone. In addition, an adhesive is applied to the refilled portion of the silicone coating formed by the first molding. Then, a portion of the FRP tube 16 which is not coated with silicone is set in the mold 11 as shown in FIG. 2, and silicone is injected into the space 15 and pressurized and heated as described above. As described above, when the first molding is performed, the outer diameter of the silicone refill portion 21 is formed to be smaller than the body size of the molded body, and therefore, as shown in FIG. Is covered with the silicone 20b, and the silicone 23a and the newly coated silicone 23b adhere to each other with the adhesive applied to the silicone 20a. Further, since the mold plate 8 is not coated with the release agent, the adhesive strength of the adhesive surface 23 does not decrease.

[0010] As described above, the mold of the present embodiment is composed of the mold plates 1 to 8, 9, and 10 each composed of one shade which is the shape of a molded body.
Are connected by bolts, so that the required number of shelves can be connected, so that silicone insulators / porcelain tubes of any number of sheds can be manufactured. As shown in FIG. 4, a fluororesin coating 22 is formed on at least the surface of the mold plate 8 forming the seam, which is in contact with the silicone of the molding resin.
Is formed and the release agent is applied to the other mold plates, so that the adhesive force of the adhesive applied to the refill portion 21 is not reduced by the release agent. When the silicone porcelain tube / insulator was molded by the above method, the silicone was easily released from the mold without breaking the silicone without applying a release agent to the mold plate 8, and the refilling portion 24 was molded without reducing the adhesive force. I was able to do it.

The order of molding is not limited to the above embodiment. For example, molding may be repeated from the opposite side. In addition, it is also possible to adopt a configuration in which only an end mold plate serving as a replenishing portion is divided by an integral mold without being divided by one shade which is the shape of a molded body. In any of the methods, any number of mold plates on which the fluororesin coating is formed can be used. However, if the number is too large, an expensive molding die is obtained and the effect is reduced.

[0012]

As described above, according to the present invention, in a molding die for producing a silicone insulator / porcelain tube by molding a plurality of times, at least a surface of a seam of a silicone coating, which is in contact with silicone, is coated with a fluororesin. Since the release agent is formed, the release agent does not adhere to the seam, and the adhesive strength of the seam can be improved. For this reason, a silicone insulator tube / insulator having good electric characteristics can be formed.

[Brief description of the drawings]

FIG. 1 is a diagram (at the time of a first molding) for explaining a method for producing a molding die and a silicone porcelain tube according to an embodiment of the present invention.

FIG. 2 is a diagram (at the time of a second molding) for explaining a molding die of the embodiment of the present invention and a method for manufacturing a silicone porcelain tube using the molding die.

FIG. 3 is a view showing an embodiment of a template forming a seam.

FIG. 4 is a detailed view of a joint of a silicone porcelain tube formed by a mold according to an embodiment of the present invention.

FIG. 5 is a view showing an FRP tube and an aluminum flange.

FIG. 6 is a view showing an example of a silicone porcelain tube.

[Explanation of symbols]

 Reference Signs List 1 to 10 template 11 mold 12 injection nozzle 13 flow path 14 runner 15 space in which molded body is formed 16 FRP tube 17, 18 aluminum flange 20 silicone 21 refill portion 22 fluororesin coated surface 23 interface between silicone and silicone

Claims (1)

[Claims] 1. The above-mentioned operation is repeated by using a mold shorter than the silicone insulator / porcelain tube to be manufactured, placing an unformed portion of the tube or rod in the mold and applying a silicone coating to the tube or rod. A molding die for manufacturing a silicone insulator or a porcelain tube for forming a silicone coating on a pipe or a rod, wherein a fluororesin coating is formed on at least a surface of the molding die forming a joint portion of the silicone coating which is in contact with silicone. A molding die for silicone coating of silicone porcelain tubes and insulators, characterized by: