JPH069413Y2 - Mounting structure of mold cone to bushing of switch with gas - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial application] The present invention relates to a mounting structure of a mold cone on a bushing of a gas-containing switch.

[Prior Art] Conventionally, in a switch with gas, as shown in FIG. 4, a conductive rod 2 whose base end is inserted into the bushing body 1 is used.
Is provided with a flange portion 2a, and the end surface of the flange portion 2a is abutted and supported on the end surface of the bushing body 1 via a sheet 7 as a cushioning member, and the tip end portion of the conductive rod 2 is abutted and supported by the contact support structure of the end surfaces. It is known that the weight of the lead wire 3 and the mold cone 4 that covers the fixed portion are held. In this case, the sheet 7 interposed between the end surface of the bushing body 1 and the end surface of the flange portion 2a of the conductive rod 2 is made of metal.
a bushing body 1 made of porcelain by contact with the end face of a
It is an essential member to prevent damage to the end faces. On the other hand, between the end surface of the bushing body 1 and the inner bottom surface of the mold cone 4 which face each other on the outside of the seat 7, since the mold cone 4 is made of rubber, the seat 7 as a buffer member as described above is interposed. There is no need, and therefore, a space 8 corresponding to the thickness of the sheet 7 is formed between the end surface of the bushing body 1 and the inner bottom surface of the mold cone 4.

Further, in the bushing of the gas-filled switch, it is common to fill an arc extinguishing gas such as SF ₆ between the conductive rod 2 inserted into the bushing body 1 and the inner surface of the bushing body 1. Therefore, in order to prevent the arc extinguishing gas from leaking from the bushing body 1 to the outside, it is provided between the outer periphery of the end portion of the bushing body 1 and the inner surface of the cylindrical portion 4a of the mold cone 4 fitted to the outer periphery of the end portion. Was to be filled with the adhesive 6. In FIG. 4, 5 is an O-ring and 19 is a train tube.

[Problems to be Solved by the Invention] An epoxy-based adhesive is used as the adhesive 6 used for adhesively fixing the mold cone 4 to the bushing body 1 from the viewpoint of adhesive strength and electrical properties. In the case of an epoxy-based adhesive, it is necessary to heat and heat-set it after filling the adhesive in the necessary places. However, in the conventional mold cone 4, since the portion corresponding to the end face of the bushing body 1 is a flat surface, an annular space 8 corresponding to the existence of the sheet 7 is generated, and the space is heated when the adhesive 6 is heat-cured. There is a problem that the adhesive 6 may flow out from a predetermined portion before the air existing in 8 expands and the adhesive 6 is heated and hardened.

The present invention has been made in view of the above problems,
The purpose is to use a gas-filled switch that does not cause the adhesive to flow out from a predetermined position when heated even when using an adhesive that requires thermosetting, such as an epoxy adhesive when attaching the mold cone to the bushing. It is to provide a mounting structure of a mold cone to a bushing.

[Means for Solving the Problems] In order to achieve the above-mentioned object, in the present invention, a base end of a conductive rod having a flange portion is inserted into a bushing body, and a lead is provided at a distal end of the conductive rod. The wire is fixed, the end surface of the flange portion is brought into contact with the end surface of the bushing body via a cushioning member, and the cylindrical portion is formed at the end portion of the mold cone that covers the fixed portion between the conductive rod and the lead wire. Then, in the mounting structure of the mold cone for the bushing of the gas-filled switch in which the same tubular portion is fitted and fixed to the outer periphery of the end portion of the bushing body via a thermosetting adhesive, the inside of the tubular portion is included in the mold cone. An annular protrusion is formed at a position corresponding to the end face of the bushing body, and between the inner surface of the tubular portion and the outer periphery of the end of the bushing body while the protrusion contacts the end face of the bushing body. Was filled with the adhesive.

[Operation] With the above configuration, when the mold cone is attached to the bushing, the end face of the bushing body and the end face of the mold cone located inside the adhesive filled between the inner surface of the cylindrical portion of the mold cone and the outer periphery of the end portion of the bushing body. The space between the two is very small, which ensures that the adhesive will not flow out before curing due to thermal expansion of the air present in the space during heating for curing the adhesive.

[Embodiment] An embodiment embodying the present invention will be described below with reference to FIGS. The same parts as those of the conventional device will be described with the same reference numerals. As shown in FIG. 1, a bushing body 1 fixed to a case 9 of a gas-containing switch by a fixing member 12 via a packing 10 and an O-ring 11 has an inner cavity extending in the axial direction at its axial center portion. 13 is formed.
The lead wire 3 is fixed to the distal end portion, and the connecting portion with the lead wire 3 is covered with the mold cone 4 formed of EPDM (ethylene, propylene, diene terpolymer) to the inner cavity 13. A fixed electrode 14 is integrally formed at the base end of the conductive rod 2 to be inserted so as to project from the base end of the bushing body 1. A flange portion 2a is formed at the tip of the conductive rod 2 so that it can contact the tip end surface of the bushing body 1, and a male screw portion 2b is formed at the base end. The conductive rod 2 is loosely inserted into the inner cavity 13 with the seat 7 as a cushioning member interposed between the end surface of the flange portion 2a and the end surface of the bushing body 1.
A bushing is inserted via a buffer ring 16, a press fitting 17 and a spring 18 by a nut 15 screwed to the male screw portion 2b of the conductive rod 2 while being housed in a housing recess 1a formed at the base end of the bushing body 1. It is fastened and fixed to the main body 1. In order to prevent misalignment between the conductive rod 2 and the bushing main body 1, a regulating pipe 19 is fitted to the tip end of the conductive rod 2, and a regulating pipe 20 is fitted to the buffer ring 16 at the proximal end male screw portion 2b. It is screwed in with a gap between and. A plurality of communication grooves 21 having a small diameter are formed in the train wheel 20 so as to communicate the gap with the inner lumen 13 of the train tube 20 on the distal side. Further, a groove 22 is formed on the bottom surface of the accommodation recess 1a so as to communicate the gap with the accommodation recess 1a.

In the mold cone 4, inside the cylindrical portion 4a fitted to the tip of the bushing body 1, at the position corresponding to the end face of the bushing body 1 when the mold cone 4 is attached to the bushing body 1, the thickness of the sheet 7 The ridge 23, which is formed slightly higher and also has a function as a packing, is formed in an annular shape. An annular recess 24 is formed at the tip of the tubular portion 4a.

When the conductive rod 2 having the mold cone 4 formed therein is assembled to the bushing body 1, the conductive rod 2 having the mold cone 4 formed with the adhesive 6 applied to the outer peripheral surface of the tip of the bushing body 1 is used. Tip of 2 (mold cone side)
The seat 7, the O-ring 5 and the train control tube 19 are fitted to the bushing body 1 and inserted into the inner cavity 13 from the tip side.
Next, the train tube 20 is screwed onto the male screw portion 2b of the conductive rod 2, and the buffer ring 16, the press fitting 17 and the belleville spring 1 are also attached.
After fitting 8, the nut 15 is screwed and the conductive rod 2 is fastened and fixed to the bushing body 1. In this state, the adhesive 6 is filled in the recess 24 of the cylindrical portion 4a of the mold cone 4, and the adhesive 6 is heated to cure it. In the conventional mold cone, since there is a space corresponding to the thickness of the sheet 7 between the end surface of the bushing body 1 and the mold cone 4, the air in the space is thermally expanded before the adhesive 6 is cured by heating. As a result, the adhesive 6 may flow out from between the end peripheral surface of the bushing body 1 and the inner surface of the tubular portion 4a of the mold cone 4, and the mold cone 4 and the bushing body 1 may not be bonded well. However, since the mold cone 4 of the present invention is formed with the annular protrusion 23 that abuts against the end face of the bushing body 1, the space inside the adhesive 6 becomes extremely small, and the pressure rise due to thermal expansion increases. Is low and is relaxed by the ridge 23, and the adhesive 6 is applied when heated.
There is no pressure on the side and the adhesive 6 does not flow out.

When the bushing configured as described above is assembled in a gas-filled switch, when a flashover or a short-circuit accident occurs in the gas-filled switch case 9, the heat generated in the case causes a high temperature. The arc-extinguishing gas having a high pressure does not suddenly act on the inner cavity 13 of the bushing body 1, but rather the groove 22 formed in the bushing recess 1a of the bushing body 1 and the communication groove 21 formed in the train tube 20. Since it gradually penetrates into the lumen 13 through it, the bushing is not damaged by the action of the high-temperature and high-pressure arc-extinguishing gas.

The present invention is not limited to the above embodiment,
For example, as shown in FIG. 3, the protrusions 23 formed on the mold cone 4 may be doubled.

[Advantages of the Invention] As described in detail above, according to the present invention, when the mold cone is fixed to the bushing body, even if the adhesive is heated to cure the adhesive, the adhesive expands due to the thermal expansion of the air present inside. It is reliably prevented from flowing out before curing.

[Brief description of drawings]

1 and 2 show an embodiment embodying the present invention. FIG. 1 is a partially cutaway front view of a bushing, FIG. 2 is a partially cutaway perspective view of a mold cone, and FIG. FIG. 4 is a partially cutaway perspective view of a modified mold cone, and FIG. 4 is a partially cutaway front view showing a state in which a mold cone and a bushing body of a conventional device are attached. Bushing body …… 1, conductive rod …… 2, lead wire ……
3, mold cone …… 4, cylinder …… 4a, adhesive ……
6, sheet as cushioning member ...... 7, space ...... 8, lumen ...... 13, ridge ...... 23, recess ...... 24.

Claims (1)

[Scope of utility model registration request] 1. A base end portion of a conductive rod having a flange portion is inserted into a bushing body, while a lead wire is fixed to a tip portion of the conductive rod, and an end surface of the flange portion is attached to an end surface of the bushing body. On the other hand, a cylindrical portion is formed at the end of the mold cone that covers the fixed portion of the conductive rod and the lead wire while making contact with the cushioning member, and the cylindrical portion is thermoset on the outer periphery of the end of the bushing body. In a structure for mounting a mold cone on a bushing of a gas-filled switch fitted and fixed via a conductive adhesive, the mold cone has an annular ridge at a position corresponding to an end face of the bushing body inside the tubular portion. To form
A mold for a bushing of a gas-operated switch, characterized in that the adhesive is filled between the inner surface of the tubular portion and the outer circumference of the end portion of the bushing body in a state where the ridge is in contact with the end surface of the bushing body. Cone mounting structure.