JPH0575567B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] This invention accommodates a lightning arrester element mainly made of zinc oxide with nonlinear voltage-current characteristics inside a voltage-resistant insulating tube made of reinforced synthetic resin. This invention relates to a lightning arrester insulator formed by molding an insulating material such as rubber or resin onto the outer periphery of the voltage-resistant insulating cylinder, or a mold for a molded insulator having only an insulating function.

[Prior Art] In general, a lightning arrester has a lightning arrester element mainly made of zinc oxide, which has non-linear voltage-current characteristics, housed in series inside a voltage-resistant insulating tube made of reinforced synthetic resin, etc. Electrode fittings are fitted to both ends of the cylinder, and rubber is molded onto the outer peripheral surface of the pressure-resistant insulating cylinder using a mold to form a rubber molded part.

Conventionally, as a mold for molding the rubber mold part of the lightning arrester, an upper mold and a lower mold are made to be removable and detachable, and a voltage-resistant insulating tube is placed in the center of the cavity formed inside both molds. The molds are arranged horizontally and evacuated, and in this state, a pressurized rubber injection device is used to fill the molds with flowable rubber through injection holes formed at the contact interface between the two molds. In addition, in order to prevent the voltage-resistant insulating cylinder from curving when the insulator is injected under pressure, a support rod for preventing curvature is inserted into the insertion hole formed at the contact interface between the two molds, and its tip edge is inserted into the pressure-resistant insulating cylinder. A structure in which an insulator is injected under pressure while in contact with an insulating cylinder has been proposed.

[Problems to be Solved by the Invention] However, in this conventional mold, the support rod was simply inserted into a groove formed at the contact interface between the molds, so when the cavity was evacuated, the rod was separated. Due to the possible combination of both molds and the support rod, there was a problem in that it was difficult to maintain airtightness around the support rod. In addition, a structure has been proposed in which the support rod is inserted into the lower mold and a pressurized rubber injection device is attached to the upper side of the upper mold, but this method requires troublesome adjustment of the position of the support rod. Not only that, but there was also the problem that the rubber filling workability deteriorated.

This invention was made by focusing on the problems that exist in the conventional technology, and its purpose is to easily ensure sealing between the two separable molds and the operating rod. It is possible to resist mold molding.

[Means for Solving the Problems] In order to achieve the above object, the present invention includes upper and lower molding molds that are separable from each other, and a pressure injection device for insulating material near the contact interface between the two molding molds. , the position of a deformation prevention rod that prevents curvature of the core material constituting the molded object accommodated in the cavities of both molds is adjustable in the lateral direction near the contact interface on the opposite side of the pressurized insulator injection device. An operating rod is connected to the base end of the deformation prevention rod, and the operating rod is inserted into an insertion hole formed through the lower mold or the upper mold, and the outer circumferential surface of the operating rod is A sealing member is interposed between the insertion hole and the inner peripheral surface of the insertion hole.

[Function] Since the present invention is configured as described above, the operating rod is not located at the contact interface between the upper mold and the lower mold, and therefore a sealing member is simply interposed between both molds. , it is possible to easily ensure airtightness within the cavity of the mold.

[Example] Hereinafter, an example embodying the mold of the present invention will be described in detail based on FIGS. 1 to 5.

As shown in FIG. 3, a lower mounting plate 2 is fixed to the upper surface of the fixed support plate 1 with bolts, and a lower mold 3 is fixed to the upper surface of the lower mounting plate 2. As shown in FIG. An upper mold 6 is fixed to the lower surface of a movable support plate 4, which is operated by an elevating mechanism (not shown) above the lower mold 3, via an upper mounting plate 5. A molding cavity 7 having a cap molding part 7a for molding a rubber mold part of the lightning arrester is formed in both molds 3 and 6. Further, a fixed cylinder 8 is attached to the right side of the lower mold 3, a movable cylinder 9 is attached to the right side of the upper mold 6,
Inside both cylinders 8 and 9, a piston 10 for injecting molten rubber R under pressure into the molding cavity 7 through an injection hole 11 communicating with the cap mold 7a is reciprocated by a drive mechanism (not shown). accommodated as possible. Note that 12 and 13 are support blocks for supporting the fixed cylinder 8 and movable cylinder 9.

On the left side of the lower mold 3 and upper mold 6 are a lower first mounting block 14, a lower second mounting block 15, a lower third mounting block 16, and an upper first mounting block.
mounting block 17, upper second mounting block 18,
The upper third mounting block 19 is fixed in sequence. Furthermore, a through hole 16a is horizontally passed through the lower third mounting block 16, and the through hole 16a
An operating rod 21 is penetratingly supported so that it can reciprocate. An engaging hole 21a is formed in the tip of the operating rod 21 in the vertical direction, and a support pin 22 is supported in the locking hole 21a so as to be able to reciprocate in the vertical direction. A deformation prevention rod 23 is connected to the tip of the support pin 22 by a connecting pin 24 so as to be rotatable in the vertical direction. Furthermore, a support plate 2 is provided at the tip of the deformation prevention rod 23.
5 is fixed and is in contact with the outer circumferential surface of a counter-pressure insulating cylinder 41 constituting a lightning arrester housed in the molding cavity 7. The deformation prevention rod 23 is supported so as to be able to reciprocate in the horizontal direction by an insertion hole 26 formed at the contact interface when the lower mold 3 and the upper mold 6 are combined. and,
An accommodating recess 7b into which the plate 25 can be fitted is formed on the inner peripheral surface of the cavity 7 corresponding to the support plate 25.

Further, a pin accommodation chamber 2 that accommodates the support pin 22 is provided.
7 and the molding cavity 7 are in communication with each other through a gap between the inner peripheral surface of the insertion hole 26 and the outer peripheral surface of the deformation prevention rod 23. Said operating rod 21
An O-ring 28 is fitted onto the outer peripheral surface of the pin accommodating chamber 27 to maintain airtightness between the pin accommodating chamber 27 and the outside. An operating pin 29 is fixed through the outer end of the operating rod 21. This operation pin 30
As shown in FIG. 2, it is supported by an elongated hole 30a formed in a support frame 30 fixed to the left side of the lower third mounting block 16 so as to be able to reciprocate in the horizontal direction. Further, a stopper bolt 31 is screwed onto the tip of the support frame 30, so that even if the pressure-resistant insulating cylinder 41 receives a pressing force during pressurized injection of rubber R, the support frame 30, stopper bolt 31, operating rod 21, and support pin 22, a deformation prevention rod 23, a support plate 25, etc. allow it to be held in a predetermined position.

A suction passage 32 is formed in the upper third mounting block 19 to communicate the pin accommodating chamber 27 with a vacuum device (not shown) to bring the inside of the molding cavity 7 into a vacuum state. Furthermore, 33
is a sealing member for maintaining airtightness within the cavity 7.

Next, a method of molding a lightning arrester using the mold configured as described above will be described.

First, as shown in FIGS. 3 and 4, electrode fittings 42 and 43 are placed in the cavities 7 of the upper and lower molds 6 and 3.
A support plate 25 is fixed to the tip of the deformation prevention rod 23 and is brought into contact with the outer circumferential surface of the pressure insulating tube 41, and the stopper bolt 31 is rotated so that the tip is attached to the operating rod 2.
Abuts on the outer end of 1. It is desirable to apply an adhesive to the surface of the voltage-resistant insulating cylinder 41 in order to improve the adhesion with the rubber mold part 44, and to prevent the adhesive from being peeled off by the support plate 25, the plate 25 is treated with Teflon in advance. It's good to keep it.

Next, operate a vacuum device (not shown),
After evacuating the inside of the cavity 7, the rubber R in the cylinders 8 and 9 is heated and melted, and the pressurizing device is operated to move the piston 10 to the left in FIG. Press R into the cavity 7. During this press-fitting, the voltage-resistant insulating cylinder 41
Although it is pressed leftward in the figure, this pressing force is blocked by the support frame 30, stopper bolt 31, operating rod 21, support pin 22, deformation prevention rod 23, support plate 25, and the like.

Thereafter, rubber R is injected into the cavity 7, and with the pressurizing force no longer acting on the deformation of the pressure-resistant insulating cylinder 41, the stopper bolt 31 is rotated in the loosening direction, and the operating rod 21 and the deformation prevention rod 23 are rotated. When the support plate 25 is moved back by a predetermined distance and accommodated in the accommodation recess 7b, the entire cavity 7 is filled with the rubber R, and the pressurized injection operation of the rubber R is completed.

Next, when the rubber R in the cavity 7 is cooled and hardened, the upper mold 6 is moved upward together with the first to third upper mounting blocks 17 to 18, the upper support block 13 and the upper cylinder 9, and the lower mold is removed. Stay away from 3.

Next, the completed lightning arrester is taken out from the cavity 7 as shown in FIG. At this time, the deformation prevention rod 23 is rotatably connected to the support pin 22 by a connecting pin 24, so that when the lightning arrester is rotated upward, the support plate 25
Therefore, damage to the rubber mold part 44 is prevented.

Now, in the present invention, the operating rod 21 is not located at the contact interface between the upper mold 6 and the lower mold 3, and therefore, the seal member 21 is simply attached to both the molds 6, 3.
3, airtightness within the cavity 7 can be easily ensured. Furthermore, since the deformation prevention rod 23 is exposed at the upper part of the lower mold 3, its position can be easily adjusted when setting the voltage-resistant insulating tube 41, and maintenance and inspection can also be facilitated.

Note that the present invention can also be embodied as follows.

The operating rod 21 and the deformation prevention rod 23 may be connected and fixed, and the present invention may be applied to the molding of various products having a core material in the center other than the lightning arrester and an insulating material molded on the outside.

[Effects of the Invention] As explained above, according to the mold of the present invention, the position of the operating rod is not adjusted at the contact interface between the upper mold and the lower mold, and therefore, the position of the operating rod is not adjusted to the contact interface between the upper mold and the lower mold. There is an effect that airtightness can be easily ensured simply by interposing the sealing member.

[Brief explanation of the drawing]

FIG. 1 is a partial cross-sectional view of a mold embodying the present invention, FIG. 2 is a cross-sectional view taken along the line A-A in FIG. 1, FIG. 3 is a cross-sectional view showing the entire mold, and FIG. This figure is a plan view showing the entire molding die, and FIG. 5 is a sectional view showing a state in which the upper molding die is separated and a molded object is taken out. 3...Lower mold, 6...Upper mold, 7...
Molding cavity, 14-15...first to third lower mounting blocks, 16, 19...first to third upper mounting blocks, 16a...through hole, 21...
Operation rod, 22...Support pin, 23...Deformation prevention rod, 24...Connection pin, 25...Support plate, 26...Through hole.

Claims (1)

[Claims] 1. Upper and lower molding molds that can be separated from each other and a pressurized insulating material injection device are installed near the contact interface between the two molding molds. A deformation prevention rod that prevents the core material constituting the molded object housed in the cavity of the mold from curving is arranged so as to be able to adjust its position in the lateral direction.
An operating rod is connected to the base end of the deformation prevention rod, and the operating rod is inserted into an insertion hole formed through the lower mold or the upper mold, so that the outer peripheral surface of the operating rod and the insertion hole are connected to each other. A molding die characterized in that a sealing member is interposed between the molding die and the inner peripheral surface.