JPH0713383Y2 - Bus duct - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Technical Field of the Invention) The present invention relates to a bus duct useful when used as, for example, a power supply line having a large current capacity.

(Technical background of the invention and its problems) As a conventional bus duct, one having a plate-shaped comb-shaped insulating holder having a recess for supporting a conductor is known.
However, when this comb-shaped insulation holder is used for a high-voltage bus duct, the holder is simply formed in a plate shape, so the conductor distance and the distance between the conductor and the housing wall surface are increased to secure the creepage distance. There is a need to.
Therefore, the bus duct becomes larger by that amount, and there is a problem in terms of installation space and economy.

Further, as shown in FIG. 2, a high-voltage bus duct having a structure in which a plurality of insulators 2 are fixed in a housing 1 and each conductor 4 is supported by the pressure of a support metal fitting 3 mounted on these insulators 2 is put to practical use. Has been done. In the bus duct having such a structure, since the support fittings 3 are formed wide to support the conductors 4, in order to secure a predetermined interphase distance and ground distance, the spacing between the support fittings 3 and the housing 1 and the support fitting 3 are secured. It is necessary to increase the interval between and. Therefore, the bus duct becomes large in size as described above. Further, when using an insulator and a support fitting for each such conductor, the number of parts increases, so that it takes a lot of time and labor to assemble the bus duct, and the bus duct itself becomes expensive. I cannot escape.

By the way, in Japanese Utility Model Laid-Open No. 56-63218, an insulating holder having a quadrangular cross section is arranged in a non-contact state with a wall surface inside a housing via a buffer, and a concave groove is provided on surfaces of the insulating holder which face each other. A high-voltage bus duct having a structure in which a buffer body is provided and a conductor is supported through the buffer body is shown. When the insulating holder and the cushioning body are combined in this way, leg portions for attaching the spacing cushioning body are formed at both ends of the insulating holder, and projections for increasing the creepage distance are provided or embedded in the insulating holder. By doing so, each creepage distance between the phase and the ground can be increased. Therefore, the creepage distance can be sufficiently secured even if the conductor distance and the distance between the conductor and the wall surface of the housing are reduced, so that the bus duct can be downsized. However, if the insulation holder is provided with legs or protrusions for increasing the creepage distance, or if the holder has a structure in which the protrusions are embedded, the holder shape becomes very complicated. I have no choice but to produce
Therefore, the unit price of each holder becomes very expensive, which is uneconomical. Further, as described above, when the buffer body for separating and for supporting the conductor is used, the number of assembling steps of the bus duct increases, and thus the work takes time and labor. Further, when an insulating holder having a quadrangular cross section is used, dust easily adheres to the upper surface thereof, which also has a drawback of causing a flashover of the surface.

For this reason, the applicant has previously proposed a bus duct in which the bus bar 9 is supported by upper and lower cylindrical insulating holders 10 having a plurality of annular grooves 10a for supporting conductors on the peripheral surface as shown in FIG. is doing. (Application No. 59-89063) In such a bus duct, each insulation holder 10 is formed in a cylindrical shape as shown in FIG.
11 is installed. Therefore, the metal fitting 11 has a semicircular portion 11a formed to have a diameter smaller than the outer diameter of the insulating holder 10.
And an extending portion 11b that extends in the radial direction of the holder 10 and projects slightly in the radial direction from the outer peripheral surface of the holder 10, and forms the peripheral wall of the protruding portion 11c that protrudes into the holder 10 and the inner peripheral wall of the holder 10. It is attached to the holder 10 by being fixed via a cementing agent 12 such as cement.

Therefore, in the bus duct having such a configuration, since the metal fittings are present at both ends of the insulating holder, it is necessary to separately manufacture the metal fittings, and a work for mounting the metal fittings is required. It takes a long time, and eventually there is a drawback that it becomes an expensive bus duct.

(Purpose of the Invention) The present invention has been made based on the above circumstances, and it is an object of the invention to provide a bus duct that can effectively prevent the occurrence of creeping flashovers, and that can easily and inexpensively manufacture an insulating holder. is there.

(Outline of the Invention) In the present invention, in a dust duct in which a bus bar is supported by upper and lower cylindrical or columnar insulating holders having an annular groove for supporting the bus bar on the peripheral surface, the outer diameter of both ends of the insulating holder is By making it larger than the other portions, it is possible to easily and inexpensively manufacture the insulating holder.

Embodiments of the Invention Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In FIG. 1 in which the same parts as those in FIGS. 3 and 4 are designated by the same reference numerals, the bus duct according to the present invention comprises a housing 5. The housing 5 includes a bottom plate 6, a pair of side plates 7 and 7 fixed to both sides of the bottom plate 6 so as to face each other along the longitudinal direction thereof, and a lid 8 fixed to the side plates 7 and 7. It consists of and. It should be noted that the metal fittings 7a and 7a face the inner wall surfaces of the pair of side plates 7 and 7, respectively.
In addition, they are provided in two steps, one above the other and a predetermined distance apart from each other along the longitudinal direction. Here, each bracket 7a, 7a
Serves as a guide for the folds 13 at both ends of the insulating holder 10. For example, the inner wall surface of the side plate 7 has a width substantially equal to the outer diameter of the folds 13 at both ends of the insulating holder 10. , Is composed of two ridges protruding in the vertical direction.

Then, in the housing 5, a plurality of conductors 9 are arranged in parallel along the side plate 7, and each conductor 9 is supported by insulating holders 10, 10 which are vertically opposed to each other.

Each insulation holder 10 is formed in a cylindrical shape,
The outer diameters of both end portions of 10 are larger than those of the other portions, that is, the outer diameters of the pleats 13 at both end portions are made larger than the outer diameter of the pleats 14 in the middle portion.

A plurality of annular grooves 10a for supporting the conductors 9 are provided on the peripheral surface of the insulating holder 10 at equal intervals along the axial direction, and the creeping distance is provided between the annular grooves 10a and at both ends. A plurality of securing annular grooves 10b are provided.

Next, a process of assembling the high-voltage bus duct according to the present invention will be described.

First, a gutter-shaped housing is obtained by the bottom plate 6 and the pair of side plates 7, 7 fixed to face each other along the longitudinal direction thereof.
Then, both end portions of the insulating holder 10 to be arranged below, that is, the folds 13 are inserted into the receiving metal fittings 7a, 7a arranged in the lower stage so as to be dropped. As a result, the insulating holder 10 with the large-diameter fold 13 in contact with the bottom plate 6
Can be disposed below the housing 1.

Then, the conductors 9 of the respective phases are put in the supporting annular grooves 10a of the insulating holder 10 arranged as described above to support the lower portions of the conductors 9 and to the metal fittings 7a, 7a fixed above the side plates 7, 7. Both ends of the insulating holder 10 to be placed above, that is, the folds 13
Engage as if dropping in. As a result, the upper portions of the conductors 9 of the respective phases can be inserted into and supported by the supporting annular grooves 10a of the insulating holder 10. Finally, the lid plate 8 is put over the upper end faces of the measuring side plates 7 and 7, and the lid plate 8 is pressed until the upper position of the fold 13 of the insulating holder 10 is flush with the upper end face of the side plate 7. And fix it with bolts.

Now, in the high-voltage bus duct of the present invention assembled in this way, the annular groove 10b for securing a plurality of creepage distances is provided on the circumferential surface.
Since the conductor 9 is supported by using the insulating holder 10 having, the creepage distance is sufficiently increased even if the conductor 9 is arranged to be considerably close to each other and the distance between the conductor 9 and the inner wall surface of the side plate 7 is reduced. Can be secured. Therefore, the high-voltage bus duct of the present invention has a duct cross-sectional area of about 1/3 that of the conventional bus duct of this type, which is small. Insulation holder 10
When the annular groove for securing the creepage distance is provided in the above, as described above, the insulating holder 10 is arranged so as to be simply dropped into the housing 1 without using any other member such as a shock absorber, and the cover plate 8 is bolted. Since the bus duct can be assembled simply by stopping it, the assembly work can be completed easily and in a short time. In addition, the insulation holder 10
When the cylinder is formed into a cylindrical shape or a cylindrical shape, the adhesion of dust to the holder 10 is extremely reduced, so that there is almost no risk of a surface flashover due to the dust, and therefore an increase in internal pressure can be effectively prevented. Then, if the insulating holder 10 is formed in a cylindrical shape or a cylindrical shape and has a simple structure in which the annular grooves 10a, 10a are simply provided on the peripheral surface, the insulating holder 10 has a symmetrical shape, so that a simple machine The insulating holder 10 according to the present invention can be manufactured only by processing, for example, forming a circumferential groove on a peripheral surface of a cylindrical material by a lathe. Therefore,
Combined with the small size and the small number of parts, the bus duct can be provided at a very low cost.

The cover plate 8 is covered over the upper end faces of both side plates 7 and 7, and the cover plate 8 is pressed to the position where the upper portion of the fold 13 of the insulating holder 10 is flush with the upper end face of the side plate 7. When fixed by the
With 0 and 10, it is possible to reliably clamp and support. Therefore, even if the bus duct of the present invention is laid vertically, the conductor 9 does not come off the holder and fall from the bus duct.

In the above embodiment, the insulating holder 10 may be made of an insulating material such as porcelain or epoxy, and may be made of an inorganic material having good tracking resistance.

Of course, the conductor 9 may be either a bare conductor or an insulating coated conductor.

In the above embodiment, an example in which the present invention is applied to a high-voltage bus duct is shown, but the present invention can also be applied to a low-voltage bus duct. In this case, the insulating holder 10 only needs to be provided with the annular groove 10a for supporting the conductor.

(Effect of the Invention) According to the present invention, the insulating holder is formed in a cylindrical shape, and a plurality of annular grooves for supporting the conductor are provided on the peripheral surface thereof, thereby effectively preventing dust from adhering to the insulating holder. In addition, if a plurality of other annular grooves for securing the creepage distance are provided outside the above-mentioned annular groove on the holder circumferential surface, the conductor spacing and the like can be reduced by using the insulating holder without using other members. However, it is possible to secure a sufficient creeping distance. Further, since the insulating holder has a simple structure in which the annular groove is provided in the cylindrical body or the columnar body, its manufacture is very easy. Therefore, it is possible to provide a bus duct that is inexpensive and has excellent electrical characteristics, and in the case of providing an annular groove for securing a creepage distance on the holder peripheral surface, the assembly is extremely easy, and a small high-voltage bus duct is very small. It can be provided at low cost. In addition, if the number of bus duct parts is small, the transport cost will be reduced by that amount, and even for high voltage bus ducts, if the conductor is supported only by the insulating holder as described above, the low voltage bus duct and structure will be reduced. Since they are the same, there is an advantage that common jigs can be used.

Furthermore, when compared with the insulating holder shown in FIG. 4, since there is no metal fitting at both ends, there is no need to manufacture a metal fitting,
As a result, the work for attaching the metal fittings is not necessary, so that the manufacturing can be performed easily and at low cost. Further, only the folds 13 at both ends of the insulating holder are in contact with the lid plate 5 and the bottom plate 6, and the intermediate portion is arranged in a state of being electrically floated from the bottom plate 6 and the lid plate 5, that is, the ground. Since the creepage distance is large, the number of annular grooves 10a for increasing the creepage distance can be reduced or the thickness of the annular groove 10a for increasing the creepage distance can be reduced as compared with the insulating holder shown in FIG. Therefore, there is an advantage that the insulating holder can be downsized as a whole.

[Brief description of drawings]

FIG. 1 is a sectional view of a bus duct according to the present invention, FIGS. 2 and 3 are sectional views of a conventional high-voltage bus duct, and FIG. 4 is an enlarged sectional view of the insulating holder shown in FIG. 1, 5 ... Housing 3 ... Supporting metal 4, 9 ... Conductor 7 ... Side plate 7a ... Receiving metal 8 ... Lid plate 10 ... Insulating holder 10a, 10b ... Annular groove 11 ... Metal fitting 13 ... Large diameter fold 14 ... Small diameter fold

Claims (1)

[Scope of utility model registration request] 1. In a bus duct in which bus bars are supported by upper and lower insulating holders each having an annular groove for supporting the bus bar on a peripheral surface, the outer diameters of both ends of the insulating holder are larger than those of other portions. A bus duct characterized by this.