JPH047644Y2 - - Google Patents

Description

[Detailed explanation of the idea] [Technical field of invention] The present invention relates to a lead wire with a molded cone.

[Technical background of the invention and its problems] Tracking-resistant materials, such as EP, have traditionally been used as lead wires for high-voltage overhead power distribution equipment such as pole-mounted switches to alleviate the electric field of the lead wire at the insulator insertion part of the equipment case. A so-called lead wire with a molded cone, in which a molded cone portion made of rubber is provided at the end, is often used.

As shown in FIG. 1, a conventional lead wire with a molded cone has a terminal fitting 3 fitted onto a conductor 2 at the end of a lead wire 1, and a terminal fitting 3 and an insulator 4 at the end of the lead wire. A conical mold cone portion 5 is integrally provided on the top. The mold cone portion 5 of such a conventional lead wire is formed in the following manner.

That is, FIG. 2 shows an example of molding the end portion of the lead wire. As shown in the figure, the end of the lead wire 1 with the terminal fitting 3 compressed and connected onto the conductor 2 is placed in a mold 6 divided into upper and lower parts having a conical cavity, and a set screw is attached to the end face of the terminal fitting 3. 7
to abut the side wall member 8.

A predetermined amount of rubber is press-fitted onto the end of the lead wire from a position communicating with the cavity of the mold or from a plurality of injection ports 9 to form a mold cone portion 5. The rubber is press-fitted by pressing the injection plate 11 fitted into the pot 10 at the top of the mold.

Therefore, the mold cone part 5 is required to have a smooth surface and no molding burrs, such as burrs at the seam of a two-split mold, so that tracking does not easily occur in the conical part. A seamless conical sleeve 12 is inserted inside. Therefore, the minimum inner diameter of the sleeve 12 is slightly larger than the outer diameter of the lead wire, and the mold 6 cannot suppress the outer surface of the lead wire from the outside. If rubber is press-fitted to form the mold cone portion in this state, the following problem will occur.

(1) The insulator 4 of the lead wire 1 moves by 5 to 25 mm due to the rubber injection pressure, increasing the distance T between the terminal fitting 3 and the end face of the insulator 4, as shown in Figure 3, and increasing the amount of space in the mold. Cavity volume increases. Therefore, when a certain amount of rubber is injected, air bubbles and spaces are generated in the mold cone portion 5, and the electrical characteristics are significantly deteriorated.

(2) If the amount of injected rubber is increased in order to solve the problem of (1) above, the injected rubber will flow out of the mold 6 from the small diameter part of the mold cone, causing a so-called overflow, and the lead wire insulator 4
The amount of movement will also increase.

Moreover, the above-mentioned overflow often occurs in a part of the surface of the lead wire insulator in an undefined length, and this creates a level difference from the part where no overflow has occurred, which is unfavorable in terms of tracking resistance and appearance.

In addition, when this type of lead wire is used for high-voltage overhead equipment, since it is used at a high place on an outdoor utility pole, strong winds may cause bending, vibration, etc. at the terminal fitting attachment part, especially at part A in Figure 1. Wires are likely to break due to repeated stresses such as twisting.

[Purpose of the invention] The present invention has been made to eliminate such conventional drawbacks, and an object thereof is to provide a lead wire with a molded cone having a molded cone portion having a stable shape.

[Summary of the invention] The lead wire with a molded cone of the present invention has a terminal fitting fitted onto the conductor at the end of the lead wire, and a terminal fitting provided integrally on the terminal fitting and on the insulator at the end of the lead wire. In the lead wire with a molded cone, the terminal fitting is fitted onto a conductor and an insulator at the end of the lead wire, and is compressed and fixed onto the conductor and insulator, respectively, The above object is achieved by molding the terminal fitting onto the terminal fitting.

[Example of idea] Embodiments of the present invention will be described below with reference to the drawings.

FIG. 4 is a sectional view showing an embodiment of the present invention, and the same reference numerals are used for parts common to FIG. 1.

In the figure, a terminal fitting 3 connected to the end of a lead wire 1 is attached to a conductor 2 and an insulator 4 and compressed, and a molded cone part 5 is provided thereon by the method shown in FIG. ing. In this way, the terminal fitting 3 is made longer than the conventional terminal fitting shown in FIG. 1 by the amount of time it is attached to the insulator 4 at the end of the lead wire, and has a conductor fitting hole and an insulator fitting hole provided in advance, and the conductor 2 After being fitted into the insulator 4, it is compressed and fixed onto the conductor 2 and the insulator 4 to such an extent that it will not easily come off. Note that 13 is a screw hole for attaching the side wall member 8 shown in FIG. 2 during molding of the mold cone portion 5.

[Effects of the invention] As described above, in the lead wire with a molded cone according to the invention, one end of the terminal fitting is compressively connected to the insulator at the end of the lead wire. There is no movement of the insulator of the lead wire, and a molded cone part with a stable structure can be obtained by injecting a constant amount of rubber.

Furthermore, by automatically measuring a certain amount of rubber and putting it into the pot of the mold, it is possible to automate the molding operation. Furthermore, since the terminal fitting is fitted into the insulator, the mechanical strength of the end of the lead wire is improved, and the wire is difficult to break even under repeated bending, vibration, and twisting effects.

[Brief explanation of the drawing]

Fig. 1 is a sectional view showing a conventional lead wire with a molded cone, Fig. 2 is a sectional view illustrating a method of manufacturing the lead wire with a molded cone, and Fig. 3 is a sectional view of another conventional lead wire with a molded cone. FIG. 4 is a cross-sectional view showing an embodiment of the present invention. 1...Lead wire, 2...Conductor, 3...Terminal fitting, 4...Insulator, 5...Mold cone part, 6
……Mold.

Claims (1)

[Scope of utility model registration request] In the lead wire with a molded cone, the lead wire includes a terminal fitting fitted onto the conductor at the end of the lead wire, and a molded cone portion integrally provided on the terminal fitting and on the insulator at the end of the lead wire. A terminal fitting is fitted onto the conductor and insulator at the end of the lead wire and compressed and fixed onto the conductor and insulator, respectively, and the molded cone portion is molded onto the terminal fitting. Lead wire with molded cone.