JPH11111068A - Insulation-coated conductor - Google Patents

Abstract

(57) [Summary] To provide an insulated conductor capable of maintaining initial insulation properties for a long period of time. A powdered epoxy resin is applied to the outer periphery of a strip-shaped conductor 1A having a rectangular cross section by a fluid immersion method.
The insulating coating 2A is formed except for the end of the insulating coating 2A.
On the end face of A, a concave portion 4 is formed at the center. Even if the stress remains on the end face due to the hardening of the insulating coating 2A, the stress is relieved by the concave portion 4 formed on the end face, and the crack is not generated due to the heat cycle after the hardening and the energization / stop for a long time. Prevent outbreak. Note that the concave portion may have an arc shape instead of a U shape, and may have a wavy shape.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an insulated conductor.

[0002]

2. Description of the Related Art For example, in a main converter mounted on an electric railway vehicle and serving as a power source of a main motor, a gate turn-off thyristor used as a conversion element, a capacitor unit connected to these conversion elements, and a snubber resistor are used. The unit is connected to the unit by an insulated conductor.

In addition, since the so-called input conductor connected to the input side of the main converter has relatively few bent portions,
Insulation between the outer periphery and the ground is provided by winding an insulating tape or inserting a heat shrink tape.

[0004] On the other hand, the above-mentioned insulated conductor has many bent portions, and it is difficult to wind the bent portion with an insulating tape. Therefore, a mica sheet is adhered to the surface or a flow dipping method of epoxy resin is used. An insulating coating is formed.

The conductor connecting the conversion element, the capacitor unit, and the snubber resistor has a loss due to a starting force generated by the on / off of the conversion element for driving the AC motor at a variable voltage and variable frequency and an inductance of the circuit, and the loss. In order to suppress a rise in temperature due to the above, conductors whose current directions are opposite to each other are arranged adjacent to and parallel to each other.

As a result, the magnetic flux generated by the current flowing through the pair of conductors is canceled out to reduce the inductance. In order to further reduce the inductance, the width of the conductor is increased and the distance between the conductors is reduced. ing.

[0007]

However, in the case of such an insulated conductor in which an insulating coating is formed on a conductor having a large width, the coating in the thickness direction and the coating in the width direction of the conductor are formed during the curing of the insulating coating. The stress remaining due to the shrinkage of the conductor concentrates on the ridge of the conductor.

[0008] Then, due to the temperature rise of the conductor and the temperature difference between the night and the temperature difference between the midsummer and winter seasons due to the long-term operation of the train, and the repetition of the vibration, etc., a minute crack or peeling is caused on the covering of the ridge portion of the conductor. May occur.

[0009] Then, a weak partial discharge is generated at the cracks or peeled portions, tracking is formed over a long period of operation, the amount of charges of the partial discharge increases, and the insulation characteristics of the coating of this portion may be deteriorated. is there.

For this reason, a method of enlarging the curved surfaces of the ridge portions on both sides of the conductor to alleviate a steep shape change and dispersing a concentrated stress can be considered. However, this process increases the number of manufacturing steps, The production period becomes longer. Therefore, an object of the present invention is to obtain an insulated conductor capable of maintaining initial insulation properties for a long period of time.

[0011]

According to a first aspect of the present invention, there is provided an insulated conductor formed by exposing an end of the conductor to an outer periphery of the conductor having a rectangular cross section and having an insulating coating in close contact with the conductor. A concave portion is formed on the end surface of the insulating coating between the corner portions of the first and second portions.

[0012] The insulated conductor according to the second aspect of the present invention is characterized in that the concave portion has a U-shape, and the insulated covered conductor according to the third aspect of the invention has an arcuate concave portion. According to a fourth aspect of the present invention, there is provided an insulated conductor according to the fourth aspect, wherein the concave portion has a wavy shape.

According to a fifth aspect of the present invention, there is provided an insulated conductor formed by exposing an end of the conductor to an outer periphery of the conductor having a rectangular cross section and exposing the end of the conductor. A groove is formed on the outer periphery of the conductor inside the conductor in a direction orthogonal to the longitudinal direction of the conductor, and a stress relaxation ring forming a recess on the inner periphery of the insulating coating is inserted into the groove.

In the insulation-coated conductor according to the invention, the stress relaxation ring is made of a solid or hollow material having a circular cross section. The ring is made of rubber material. Also,
In particular, the insulated conductor according to the invention of claim 8 is characterized in that the stress relaxation ring is made of glass cloth or glass yarn.

[0015] Further, in the insulated conductor according to the ninth aspect of the present invention, the stress relaxation ring is made of a foam material. It is characterized in that the resin powder is coated by a fluid immersion method or an electrostatic coating method.

With the above-described means, in the inventions corresponding to the first to fourth aspects, the stress remaining on the end face of the insulating coating due to the shrinkage of the insulating coating during curing is reduced by the concave portion to prevent the occurrence of cracks.

Further, in the invention according to the fifth to ninth aspects, the stress remaining in the longitudinal direction of the insulating coating due to the shrinkage of the insulating coating upon curing is alleviated by the concave portion formed on the inner periphery of the insulating coating. In addition, the end of the insulating coating is prevented from peeling off.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the insulated conductor of the present invention will be described below with reference to the drawings. FIG. 1 is a partial perspective view showing a first embodiment of an insulated conductor of the present invention, and corresponds to claims 1 and 2. FIG.

In FIG. 1, an end of a conductor 1A bent into a predetermined shape from a strip-shaped copper plate is attached to the conductor 1A.
Are connected to each other, and an end of an insulated conductor (not shown) is overlapped to form a bolt hole 3 for fastening. Conductor 1
The ridge of A is slightly chamfered by rolling, and the surface of the conductor 1A is plated with nickel as a pre-process of insulating coating.

An insulating coating 2A is formed on the outer periphery of the conductor 1A except for the periphery of the bolt hole 3 by a flow dipping method of powdered epoxy resin. For this purpose, the end of the conductor 1A is masked in a substantially convex shape in a plan view and then inserted into a tank filled with epoxy resin powder, and the end of the insulating coating 2A is U-shaped concave portions 4 are formed on the upper and lower sides.

In the insulating-coated conductor thus configured, the width in the width direction of the end surface on both sides of the concave portion 4 at the end of the insulating coating 2 is determined by the concave portion 4 formed at the end of the insulating coating 2A. Since it can be reduced, the difference from the width of the insulating coating formed in the thickness direction of the conductor 1A can be reduced, and the stress concentrated on the coating formed on the ridge portion of the conductor 1A can be reduced.

In FIG. 1, the corners 4a formed on both sides of the concave portion 4 at the end of the insulating coating 2A may be slightly curved to avoid concentration of stress during curing. Similarly, the corners 4b formed on both sides of the tip of the concave portion 4 may be formed slightly curved to reduce the possibility of partial peeling of the joint with the conductor 1A.

Further, in the above-described embodiment, the end of the conductor 1A is masked in a convex shape so as to form an insulating coating 2A.
Described in the example in which the concave portion 4 is formed at the end portion. However, the release agent is applied to the conductor 1A for the portion where the concave portion 4 is to be formed and put into the fluidized immersion layer. May be cut off in a range corresponding to the above. Further, in the above embodiment, the example in which the insulating coating 2A is formed by the fluid immersion method has been described, but the insulating coating 2A may be formed by the electrostatic coating method.

FIG. 2 is a partial perspective view showing a second embodiment of the insulated conductor according to the present invention, which corresponds to FIG. 2 shown in the first embodiment, and particularly corresponds to claim 3. FIG.

FIG. 2 differs from FIG. 1 shown in the first embodiment in the shape of a concave portion formed at the end of the insulating coating, and is otherwise the same as FIG. Therefore, the same elements as those in FIG. 1 are denoted by the same reference numerals.

That is, at the end of the insulating coating 2B, FIG.
An arc-shaped concave portion 5 is formed at a position corresponding to the concave portion 4, and a short linear portion is formed on both sides of the concave portion 5 as in FIG. Also in this case, the concave portion 5
It may be formed by masking as in the embodiment described above, or may be formed by applying a release agent and cutting off.

FIG. 3 is a partial perspective view showing a third embodiment of the insulated conductor of the present invention, and corresponds to FIG. 1 shown in the first embodiment and FIG. 2 shown in the second embodiment. FIG.

FIG. 3 differs from FIGS. 1 and 2 shown in the above-described embodiment in the shape of a concave portion formed at the end of the insulating coating, similarly to the above-described embodiment. It is the same as FIG.

That is, at the end of the insulating coating 2C, FIG.
An arcuate concave portion 6 having a shorter radius than the concave portion 5 indicated by 3 is continuously formed at three places. In this case, since the stress remaining at the center of the recesses 4 and 5 in FIGS. 1 and 2 can be divided into three, the stress remaining at the ridge of the conductor 1A can be further reduced.

Note that, depending on conditions such as the width and thickness of the conductor 1A, the center of the bolt hole 3 and the recess 6 may be the same, and it may be used for positioning a washer or a countersunk washer used together with a bolt inserted into the bolt hole 3. Good. Further, although the concave portion 6 is formed in an arc-shaped continuation, it may be formed as a continuous shape of a sine wave to prevent a sharp change in shape and to prevent peeling of the tip portion.

Next, FIG. 4 is a partial perspective view showing a fourth embodiment of the insulated conductor of the present invention, which corresponds to FIGS. 1, 2 and 3 shown in the above-described embodiment. It is a figure corresponding to No. 5.

Referring to FIG. 4, FIG.
The difference from FIG. 3 is that a stress relaxation portion described later with reference to FIG. 5 is formed inside the end face of the insulating coating in parallel with the end face.

FIG. 5A shows a groove 8 having a semicircular cross section formed in a direction perpendicular to the longitudinal direction of the conductor 1B with respect to the end of the conductor 1B to form a stress relaxation portion. It is formed all around, that is, in an annular shape.

FIG. 5B shows a packing 9 made of a rubber material of an ethylene propylene copolymer for the groove 8.
Is a cross-sectional view showing a state in which is inserted. After the packing 9 is inserted, an insulating coating is formed on the outer periphery of the conductor 1B.

In this case, when the longitudinal direction of the conductor 1B is long, the stress generated at the end of the insulating coating 2D can be reduced, so that the separation phenomenon at the end face of the insulating coating 2D can be prevented.

The groove 8 may be formed by cutting, and the packing 9 may be made of a laminated material of glass cloth tape or a bundle of glass yarns instead of the rubber material. Further, a foam material such as a rubber material or a putty-like molding material may be used.

Further, a hollow metal fiber material, or a hollow material in which glass fibers or thermoplastic fibers are woven in a mesh shape may be used. Also,
A material in which a solid material described above is inserted into a hollow material may be used.

Further, in the above embodiment, the conductors 1A, 1A
Although B has been described in the case of a band plate shape, any conductor having a rectangular cross section and at least one pair of long sides of the rectangle may be applied to reduce stress concentrated on the corners.

Further, in the above embodiment, the example of the insulated conductor used in the power supply unit for the electric vehicle has been described. However, for example, the insulated conductor for connecting the high-voltage equipment incorporated in the box of the closed switchboard is used. The same applies to conductors.

[0040]

As described above, according to the first aspect of the present invention, in the insulated conductor having a rectangular cross section, an insulating coating in close contact with the conductor is formed by exposing the end of the conductor. By forming a recess on the end face of the insulating coating between the corners of the above, the stress remaining on the end face of the insulating coating due to shrinkage during curing of the insulating coating was alleviated by the recess and cracks were prevented, so long-term Thus, it is possible to obtain an insulated conductor that can maintain the initial insulation properties over the entire length.

According to a second aspect of the present invention, the concave portion is formed in a U-shape. In the third aspect of the present invention, the concave portion is formed in an arc shape. In this case, by making the concave portion corrugated, the stress remaining on the end surface of the insulating coating due to shrinkage during curing of the insulating coating was alleviated by the concave portion and cracks were prevented, so the initial insulation characteristics were maintained for a long time An insulated coated conductor that can be obtained can be obtained.

According to a fifth aspect of the present invention, there is provided an insulated conductor formed by exposing an end portion of a conductor on an outer periphery of a conductor having a rectangular cross section and exposing the end portion of the conductor. By forming a groove on the outer periphery of the conductor inside the groove in a direction perpendicular to the longitudinal direction of the conductor, and inserting a stress relaxation ring forming a concave portion on the inner periphery of the insulating coating into the groove, the insulating coating is cured. The stress remaining in the longitudinal direction of the insulating coating due to the shrinkage was relieved by the concave portion formed on the inner periphery of the insulating coating, and the exfoliation of the end of the insulating coating was prevented, so that the initial insulating properties were maintained for a long time. The obtained insulated conductor can be obtained.

According to the invention corresponding to claim 6, the stress relaxation ring is a solid material or a hollow material having a circular cross section.
According to the invention corresponding to claim 7, the stress relaxation ring is made of a rubber material, and the stress remaining in the longitudinal direction of the insulating coating due to shrinkage during curing of the insulating coating is formed on the inner periphery of the insulating coating. As a result, the end of the insulating coating is prevented from peeling off, so that an insulated conductor capable of maintaining the initial insulating properties for a long period of time can be obtained.

Further, according to the invention corresponding to claim 8, the stress relaxation ring is made of glass cloth or glass yarn. Further, according to the invention corresponding to claim 9, the stress relaxation ring is formed of a foam material. Since the stress remaining in the longitudinal direction of the insulating coating along with the shrinkage during curing of the insulating coating was mitigated by the recesses formed on the inner periphery of the insulating coating, the end of the insulating coating was prevented from peeling off, The insulating coated conductor which can maintain the initial insulation characteristics over the entire length can be obtained.

[Brief description of the drawings]

FIG. 1 is a partial perspective view showing a first embodiment of an insulated conductor of the present invention.

FIG. 2 is a partial perspective view showing a second embodiment of the insulated conductor of the present invention.

FIG. 3 is a partial perspective view showing a third embodiment of the insulated conductor of the present invention.

FIG. 4 is a partial perspective view showing a fourth embodiment of the insulated conductor of the present invention.

FIGS. 5A and 5B are partial perspective views showing a fifth embodiment of the insulated conductor of the present invention, wherein FIG. 5A is a sectional view showing the conductor before the insulated coating is formed, and FIG. FIG.

[Explanation of symbols]

1A, 1B: Conductor, 2A, 2B, 2C, 2D: Insulating coating, 3: Bolt hole, 4, 5, 6: Concave portion, 7, 8, ... Groove, 9
... packing.

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Hiroto Kozu 1 Toshiba-cho, Fuchu-shi, Tokyo Inside the Fuchu Plant, Toshiba Corporation (72) Inventor Satoshi Shiori 1-futoshi-cho, Toshiba-cho, Fuchu-shi, Tokyo Inside the Fuchu Plant, Toshiba ( 72) Inventor Kazuaki Fukuda 1 Toshiba-cho, Fuchu-shi, Tokyo Inside the Toshiba Fuchu Plant, Inc.

Claims (10)

[Claims] 1. An insulated conductor formed by exposing an end portion of a conductor on an outer periphery of a conductor having a rectangular cross section and exposing an end portion of the conductor, the end surface of the insulation cover between corners of the conductor. An insulated conductor, wherein a recess is formed in the conductor. 2. The insulated conductor according to claim 1, wherein the concave portion has a U-shape. 3. The insulated conductor according to claim 1, wherein the concave portion has an arc shape. 4. The insulated conductor according to claim 1, wherein the concave portion has a wavy shape. 5. In an insulated conductor formed by exposing an end of the conductor to an outer periphery of the conductor having a rectangular cross section, the outer periphery of the conductor being inside the end of the insulative cover. A groove formed in a direction perpendicular to the longitudinal direction of the conductor, and a stress relaxation ring forming a recess in the inner periphery of the insulating coating is inserted into the groove. 6. The insulated conductor according to claim 5, wherein the stress relaxation ring is a solid material or a hollow material having a circular cross section. 7. The insulated conductor according to claim 5, wherein the stress relaxation ring is made of a rubber material. 8. The insulated conductor according to claim 5, wherein the stress relaxation ring is made of glass cloth or glass yarn. 9. The insulated conductor according to claim 5, wherein the stress relaxation ring is made of a foam material. 10. The insulated conductor according to claim 1, wherein said insulative coating is a coating by a flow dipping method or an electrostatic coating method of an epoxy resin powder.