JPH0223987B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to a grounding device for a wiring duct.

[Background technology]

A conventional example is shown in FIG. 8 and FIG. 9. That is, the inner and outer surfaces of a core 30 made of a steel plate are insulated with an insulator 31, and conductors 32 and 33 are arranged on both sides of the duct so as to face each other left and right. Core 3 throughout the entire length of the duct
By pressing the ground electrode 36 of the plug 35 against this exposed core part 34 and rotating it 90 degrees, the plug 35 is attached to the opening groove edge 38 with the hook piece 37, and the plug blade 39 is attached to the conductor 32. ，
I was in contact with 33.

However, since the upper surface inside the duct is used as a grounding electrode, there is a drawback that a conductor cannot be placed on the upper surface. In addition, when the number of conductors is odd, such as in a 3-phase 3-wire system, if the conductors are placed on both sides of the duct, they will become asymmetrical, resulting in unbalanced contact pressure between the plug blades and a dead space on one side, which is unreasonable. . Furthermore, if the ground electrode is provided in the center of the plug, the storage space for the plug blade will be reduced, and the plug will be subject to structural design constraints, making it difficult to secure an insulating distance inside the plug.

Another possible conventional example is a duct made of steel plate without insulation coating, but in the case of steel plate, all the metal parts are exposed, so there is a risk of electric shock if you touch the duct if dust accumulates and leaks. be.

[Purpose of the invention]

An object of the present invention is to provide a wiring duct grounding device that allows easy grounding without restricting the number of conductors and their arrangement, and also allows for a simple plug structure.

[Disclosure of the invention]

The wiring duct grounding device of the present invention coats the wiring duct with insulation on the inner and outer surfaces of a metal core, and forms a longitudinally extending protrusion on the edge of the open groove, exposing the tip of the protrusion. On the other hand, the plug holds the protrusion between the hook piece and the top surface,
The invention is also characterized in that a ground contact portion is provided on the contact surface of the protruding portion. Therefore, grounding can be easily achieved without any restrictions on the number and arrangement of conductors inside the wiring duct, and the plug structure can also be simplified.

An embodiment of the present invention will be described based on FIGS. 1 to 7. That is, the wiring duct 1 has a substantially channel-shaped cross section, and has a core 2 formed of a steel plate.
The inner and outer surfaces of the groove 4 are covered with an insulator 3, and the core 2 of the edge 5 of the open groove 4 has an inwardly bent portion 6 extending in the longitudinal direction, with the tip of the bent portion 6 exposed. . Inside the insulator 3, a conductor holding part 7 protrudes inward, and at the tip of the conductor holding part 7, conductors 8a, 8b,
9a to 9c are arranged. Among these, the conductors 9a to 9c on the back side are for high capacity, and the conductor 8 on the open groove side
a and 8b are for low capacity.

The plug 10 is for high capacity and consists of a case 11, a cover 12, and a plug body 13.The plug body 13 has a metal frame 14 on its upper surface, and a plug blade holder 15 protrudes from a hole in the center of the metal frame 14. Three plug blades 16a to 16c extend from the upper end, and a pair of metal hook pieces 17a, 17b extend horizontally from the base of the plug blade holder 15 in the same direction as the plug blades 16a, 16b. . Bung blade 1
6c is configured to be freely retractable and is biased in the projecting direction by a spring (not shown). Further, the metal frame 14 and the hook pieces 17a, 17b are electrically connected, and a ground terminal hole 18 is integrally formed at the end of the metal frame 14. 19 is each plug blade 16
These are cables connected to a to 16c and the ground terminal hole 18. This plug body 13 is case 1
1 with screws 20, and the cover 12 is attached to the blade holder 15 and the hook piece 17a through the opening 21.
17b and attach the plug body 13 with the screw 22.
mounted on.

FIG. 2 and FIG. 3 show the dimensional relationship in the mechanical attachment part, including the distance H ₁ between the hook pieces 17a, 17b and the upper surface 23 of the cover 12, and the wiring duct 1.
The relationship between the distance H ₂ between the upper surface and the lowermost surface of the bent portion 6 and the thickness H ₃ of the wiring duct 1 is H ₃ <H ₁ <H ₂ .

Figure 6 shows the inserted state of the plug, Figures 1 and 7.
The figure shows the plug connection state, and the plug blades 16a, 16b
Then, the plug blade holder 15 is inserted into the inside through the opening groove 4 of the wiring duct 1 with the protruding directions of the hook pieces 17a and 17b parallel to the longitudinal direction of the wiring duct 1, and the plug blade 1
With the plug 10 in contact with the conductor 9c,
Rotate degrees. As a result, as shown in FIG.
a, 16b are in pressure contact with the respective conductors 9a, 9b, and the hook pieces 17a, 17b are engaged with the upper surface of the bent part 6 of the edge 5 of the open groove 4, and the bent part 6 is connected to the hook pieces 17a, 17b due to the above-mentioned dimensional relationship. 17b and the upper surface 23 of the cover 12. Thus plug 1
0 is mechanically held in the wiring duct 1, the plug blades 16a to 16c are connected to the conductors 9a to 9c, and the core 2 of the wiring duct 1 and the ground terminal hole 18 are connected to the hook pieces 17a, 17b and the frame 14. The electrical connection will be made through the

This configuration provides the following effects. That is, (1) the hook pieces 17a, 17b of the plug 10 are connected to the open groove 4;
is supported by the bent portion 6 of the edge 5 to form a support beam at both ends, so even if the cable 19 is pulled and bending force is applied to the plug 10 and one side of the hook piece lifts up, the other side remains secure. Since it has a pressure contact structure, the contact as a ground electrode is always stable and highly reliable.

(2) The plug 10 is installed by inserting the plug 10 into the groove 4 of the duct 1 and rotating it 90 degrees. If the clamping gap of the plug hooking piece 37 was made equal to or smaller than the thickness of the duct opening groove edge 38 as shown in FIG. In this case, in the initial state when the plug 10 is rotated, the relationship H ₃ <H ₁ holds, so the hook pieces 17a and 17b easily fit into the edge 5 of the wiring duct 1, and in the installed state of rotation by 90 degrees, H ₁ < H ₂ and the upper surface of the bent portion 6 is rounded, so the spring properties of the bent portion 6 act to allow rotation without getting caught, and the spring pressure stabilizes the contact effect of grounding.

(3) Since the grounding electrode of the wiring duct 1 is provided on the edge 5, the plug blade structure of the plug 10 is simplified, and there is more space for storing the plug blade of the duct 1, and a plug blade structure with three or more poles is possible. become.

(4) Hooking piece 17a, 1 for plug 10 to duct 1
Since 7b is made of metal to serve as a grounding electrode, the strength of the attachment part of the plug 10 is increased and reliability is improved.

Note that the bent portion 6 may be configured to protrude outward and provide a ground contact portion on the upper surface side of the cover or the plug body. Furthermore, although the low capacity plugs connected to the low capacity conductors 8a and 8b of the wiring duct 1 are not shown, the grounding structure is the same as described above except for the plug blade structure. Furthermore, the plug 10 without the plug blade 16c can be similarly applied. Further, the bent portion 6 may be formed as a protrusion.

〔Effect of the invention〕

According to the present invention, the number and arrangement of conductors in the wiring duct are not limited, and there are advantages in that grounding can be easily established and the plug structure can be simplified.

[Brief explanation of drawings]

Fig. 1 is a cross-sectional view of an embodiment of the present invention in a plug-connected state, Fig. 2 is an exploded view of the hook part, and Fig. 3
The figure is a sectional view of the hook part, Figure 4 is an exploded perspective view of the high capacity plug, Figure 5 is a perspective view, Figure 6 is a perspective view of the plug insertion process, Figure 7 is a perspective view of the connected state,
FIG. 8 is an exploded sectional view of a conventional example, and FIG. 9 is a sectional view. 1...Wiring duct, 2...Metal core, 4...
Open groove, 5... Edge, 6... Bent part (projection), 8
a, 8b, 9a-9c...Conductor, 10...Plug, 15...Blug blade holder, 16a-16c...Blug blade, 17a, 17b...Hook piece (earth contact part),
23...Top surface.

Claims (1)

[Claims] 1. A wiring duct in which the inner and outer surfaces of a metal core are coated with insulation, a conductor is arranged inside, a protrusion extending in the longitudinal direction is formed on the core at the edge of the open groove, and the upper surface of the protrusion is exposed. The plug blade holder is protruded from the upper surface, and hook pieces are provided at a predetermined interval from the upper surface, and the plug blade holder and the hook piece are inserted into the opening groove and rotated 90 degrees to close the plug of the plug blade holder. A plug in which a blade is brought into contact with the conductor and a protrusion on the edge of the open groove is held between the upper surface and the hook piece; and a ground contact portion provided on a contact surface of the protrusion of the plug. Grounding device for wiring ducts.