JPH09117044A - Method and structure for grounding metal member in bus duct - Google Patents

Abstract

PROBLEM TO BE SOLVED: To ground a metallic grounding member surely while facilitating the assembling work by stripping a part of coating from the inner wall of a grounded bus duct and interposing a leaf spring between the metallic member in the bus duct and the inner wall of the bus duct such that they can interact. SOLUTION: Coating is stripped from the side plate of a duct only at the lowermost contact face 12 with a leaf spring 11 and the exposed metallic part of the duct is connected electrically with the leaf spring 11. The lead spring 11 touches respective supporting metals 6 at three top points of corrugation thereof and connected electrically therewith. The metallic member, e.g. a supporting metal 6, arranged in a bus duct can thereby be connected electrically with the duct through the lead spring 11 and grounded surely while facilitating the assembling work.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for grounding a metal member arranged inside a bus duct.

[0002]

2. Description of the Related Art A bus duct in which a plurality of bus duct conductors are insulated and arranged in a metal duct is widely used as a power supply line for a large current in a substation, a building, or a factory. Figure 3 shows a bus duct with 6
An example of arranging the bus duct conductors in two stages is shown. The duct 1 is a combination of a pair of duct side plates 2 and a duct cover plate 3 in a box shape, and bolts and nuts (not shown) near the corners.
The duct side plate 2 and the duct cover plate 3 are made of a steel plate or an aluminum plate coated with high solid lacquer enamel. In addition, a ground wire (not shown) is connected to the duct 1 in some places,
It is grounded to the ground.

In the duct 1, three insulating holders 4 are arranged at appropriate intervals in the lengthwise direction.
As shown in FIG. 4, these insulating holders 4 are made of a porcelain material having an annular projection 4a for securing a surface distance and an annular projection 4b for supporting a conductor formed on the surface thereof. The support fitting 6 is fixed by the adhesive 5. The support fitting 6 is composed of a substrate portion 6b having an extension portion 6a and a protrusion portion 6c extending from the center of the substrate portion in the axial direction of the insulating holder 4.

On the inner surfaces of the duct side plates 2 on both sides, receiving fittings 7 are fixed to the lower, middle and upper stages, respectively. These receiving fittings 7 are composed of a pair of plate bodies sandwiching the extending portion 6a of the supporting fitting from the front and back, and are fixed to the inner surface of the duct side plate 2 by welding or the like. The insulating holders 4 of the respective stages are positioned and arranged in the duct 1 by fitting the extending portions 6a of the support fittings to the receiving fittings 7 of the respective stages. Between these insulation holders 4, there are arranged and supported six bus duct conductors 8 in total, three between the lower and middle insulation holders and three between the middle and upper insulation holders. A cushion 9 is arranged between each bus duct conductor 8 and the insulating holder 4 so as to absorb an electromagnetic force applied to the bus duct conductor 8 when a short circuit occurs. As the bus duct conductor 8, a bare conductor made of copper or aluminum having a rectangular cross section is used, and when pressure resistance is required, an insulated conductor obtained by applying a heat-resistant insulating coating to these conductors is used. It may be done.

Of the above-mentioned support fittings 6, the support fittings 6 of the upper and lower insulating holders 4 are coated with a conductive connecting compound 10 between them and the duct cover plate 3 and support the middle insulating holders 4. The metal fitting 6 is coated with a conductive connection compound 10 between the metal fitting 6 and the duct side plate 2. These connection compounds 10 connect the respective support fittings 6 to the duct cover plate 3
Also, it is applied so as to have the same electric potential as the duct side plate 2, and the applied surface thereof is previously peeled off to expose the duct metal surface.

[0006]

However, in the bus duct constructed as described above, the support metal fittings of the insulating holder are simply connected by the connecting compound by fitting their extension parts to the metal fittings. Since there is no structure in which tension or compression force that firmly contacts them is applied between the support bracket and the support bracket, the gap between the support bracket and the inner surface of the duct increases due to dimensional error or deformation of the duct or the insulating holder. In this case, the connection using the connection compound alone is insufficient, and there is a risk of causing a potential difference between them and causing discharge. Further, since the painted surface of the duct has to be peeled off at each application site of the connection compound, there is a problem that the assembly work is complicated and takes time.

The present invention has been made to solve the above problems, and can reliably ground the metal member in the bus duct to be grounded, and the method for grounding the metal member in the bus duct which is easy to assemble and It is intended to provide a ground structure.

[0008]

A method for grounding a metal member in a bus duct according to the present invention is to remove a part of a painted surface of a portion of an inner wall of a grounded bus duct which comes into contact with a leaf spring,
A conductive leaf spring is mainly arranged between the metal member arranged in the bus duct and the inner wall of the bus duct so that the spring force acts between the metal member and the inner wall of the bus duct. It is a feature. Further, the grounding structure of the metal member in the bus duct of the present invention is intended for the supporting metal fitting of the insulating holder as the metal member to be grounded, and the insulating holder is arranged in the duct at appropriate intervals in the length direction. However, in a bus duct in which a plurality of bus duct conductors are arranged and supported between these insulating holders, the insulating holder is made of a porcelain material having annular protrusions, and support metal fittings are fixed to both ends thereof, An electrically conductive leaf spring is arranged between these support fittings and the inner wall of the bus duct such that the spring force acts between the support fitting and the inner wall of the bus duct, and the plate of the inner wall of the bus duct is arranged. It is characterized in that a part of the coated surface of the portion that comes into contact with the spring is peeled off.

In the above, as the leaf spring, a metal material such as phosphor bronze having excellent conductivity and high tension is used. In addition, a part of a portion of the inner wall of the bus duct that is in contact with the leaf spring is peeled off from the painted surface, and the metal member and the inner wall of the bus duct are electrically connected via the painted surface. When there are a plurality of metal members to be grounded in the bus duct, they may be connected to the inner wall of the bus duct by the same leaf spring. The leaf spring is processed into a corrugated shape and is arranged so that a spring force acts between the metal member and the inner wall of the bus duct.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below with reference to the drawings. In these figures, the same parts as those in FIGS. 3 and 4 are designated by the same reference numerals. In FIG. 1, inside the duct 1,
As in, with proper spacing along its length,
Insulation holders 4 are arranged in groups of three, three between the lower and middle insulation holders, and three between the middle and upper insulation holders.
A total of six bus duct conductors 8 are arranged and supported. The insulating holder 4 is made of a porcelain material having on its surface annular protrusions 4a and 4b for securing the extended surface distance and for supporting the conductors, and support metal fittings 6 are fixed to both ends thereof with cement or the like. The support fitting 6 is composed of a substrate portion 6b having an extension portion 6a and a protrusion portion 6c extending from the center of the substrate portion in the axial direction of the insulating holder 4.

Receiving metal fittings 7 are fixed to the inner surface of the duct side plates 2 on both sides at the lower, middle, and upper tiers, respectively, and the insulating holder 4 at each tier has an extension 6a of the supporting metal fitting.
By fitting each to the bracket 7 of each stage,
It is positioned in the duct 1. A leaf spring 11 is inserted between each support fitting 6 and the duct side plate 2. The leaf spring 11 is made of a metal material such as phosphor bronze which has excellent conductivity and high tension. A flat plate having a thickness of about 0.5 mm is formed on the curved portion 11 as shown in FIG.
a and 11b are bent in a zigzag shape and processed into a corrugated plate shape, the length of which is substantially the same as that of the duct side plate 2, and the height of the corrugation is the distance between the support fitting 6 and the duct side plate 2. It is slightly larger. This leaf spring 1
1 is inserted between the support metal fitting 6 and the duct side plate 2, and is in contact with the support metal fitting 6 at three points and at the duct side plate 2 at four points. The spring force is applied so as to separate them from each other.

In this example, the duct side plate 2 has the coating surface peeled off only the lowermost contact surface 12 of the four contact surfaces with the leaf spring 11 to expose the metal portion, The duct 1 and the leaf spring 11 are electrically connected through this portion. Further, the leaf springs 11 are in contact with the support fittings 6 and are electrically connected to each other at the three peaks of the corrugation. Therefore, each support fitting 6 is grounded to the duct 1 via the leaf spring 11 and the contact surface 12, and further grounded to the ground by a grounding wire (not shown) connecting the duct 1 and the ground. Similarly to the above, the leaf spring 11 is also inserted between the support metal fitting 6 fixed to the other end side (the left side in FIG. 1) of the insulating holder 4 and the duct side plate 2 and provided in a part of the duct side plate 2. Through the paint peeling surface 12 and the leaf spring 11, the duct side plate 2 and the support fitting 6 are electrically connected.

In the above description, an example in which the support bracket of the insulating holder is grounded to the bus duct has been described, but the present invention is not limited to this, and other metal members arranged in the bus duct may be grounded. It can be applied similarly. Further, each leaf spring has a contact surface 4 with the duct side plate 2.
Although an example in which the paint stripping surface is electrically connected to the duct side plate 2 at one location has been described, the electrical connection surface, that is, the paint stripping surface is one location per leaf spring. This is not always necessary, and a plurality of locations may be provided as long as they are a few locations on the contact surface with the inner surface of the duct.

[0014]

As described above, according to the present invention, the metal member such as the support fitting arranged in the bus duct is electrically connected to the duct through the leaf spring. Even if the gap between the support fitting and the inner surface of the duct becomes large due to dimensional error or deformation, the spring action of the leaf spring makes it possible to electrically connect the two and reliably ground them. Further, the paint peeling spots on the inner surface of the bus duct can be reduced to a part of the contact surface of the leaf spring, and the labor and time required for the assembly work of the bus duct can be reduced. Therefore, the metal member in the bus duct can be grounded easily and reliably.

[Brief description of the drawings]

FIG. 1 is a partially cutaway front view of a bus duct for explaining the present invention.

FIG. 2 is a perspective view illustrating a leaf spring used in the present invention.

FIG. 3 is a partially cutaway front view illustrating a conventional bus duct.

FIG. 4 is a side view showing an insulating holder and a support fitting in FIG.

[Explanation of symbols]

 1 ... Duct 2 ... Duct side plate 3 ... Duct lid plate 4 ... Insulation holder 6 ... Supporting metal 7 ... Receiving metal 8 ... Bus duct conductor 9 ... Cushion 10 ... Connection compound 11 ... Leaf spring 12 ...... Contact surface

Claims (4)

[Claims] 1. An electrically conductive material is provided between a metal member disposed inside the bus duct and an inner wall of the bus duct by removing a part of a painted surface of a portion of the inner wall of the grounded bus duct that is in contact with the leaf spring. 2. The method for grounding a metal member in a bus duct according to claim 1, wherein the leaf spring is arranged so that the spring force acts between the metal member and the inner wall of the bus duct. 2. The metal member in the bus duct according to claim 1, wherein the plate spring is processed into a corrugated shape, and a plurality of metal members are connected to the inner wall of the bus duct by the same plate spring. Grounding method. 3. The method for grounding a metal member in a bus duct according to claim 1, wherein the metal member is a support fitting for an insulating holder. 4. In a bus duct in which insulating holders are arranged in the duct at appropriate intervals in the length direction, and a plurality of bus duct conductors are arranged and supported between these insulating holders, the insulating holder is annular. It is made of a porcelain material with protrusions, and support metal fittings are fixed to both ends thereof, and a conductive leaf spring is supported between the support metal fittings and the inner wall of the bus duct by its spring force. Place it so that it acts between the metal fittings and the inner wall of the bus duct,
In addition, the grounding structure of the metal member in the bus duct is characterized in that a part of the painted surface of the inner wall of the bus duct that comes into contact with the leaf spring is peeled off.