JPS645953Y2 - - Google Patents

Description

[Detailed description of the invention] This invention is applied to the so-called conduit construction method in which electric wires are housed in metal pipes, and in particular relates to the structure of the connection part of metal conduit accessories. It is.

As is well known, the conduit construction method, in which electric wires are housed in metal pipes, is often used in connection with indoor (roofside, outdoor) wiring installation of electric wires. This conduit construction method is a construction method that can be installed in all exposed and impregnated locations, and is particularly suitable for buried wiring in concrete buildings, wiring in places where there is a risk of external damage, and is suitable for installation in wooden buildings. In some cases, it is also used in the form of a wall recessed type at a pull-down point leading to a switchbox or outlet.

This conduit construction method is performed by combining a conduit for storing electric wires inside and various conduit accessories for connecting the conduits to each other or connecting the internal electric wires to the target object. ing. The electrical conduits can be broadly classified into thick steel electrical conduits and thin steel electrical conduits, and these are used depending on the purpose of use. On the other hand, the conduit accessories include (a) couplings used to connect pipes, (b) boxes such as outlet boxes, concrete boxes, and switch boxes, and (c) connections between pipes and boxes. There are lock nuts, bushings, etc., which are used selectively depending on the wiring design.

Conventionally, as a means of connecting the conduit and conduit accessories used in this conduit construction method, a thread is cut on the outer periphery of the end of the conduit, and the connection part is previously formed with a screw hole. If the pipe is threaded to a pipe accessory, or if the pipe itself is thin, such as a thin steel conduit, the connection may be made by threading the pipe in advance without threading the pipe. This is accomplished by a bayonet connection to a conduit fitting that is formed by a hole that receives the outside diameter. That is, according to the conventional conduit construction method, the above-mentioned several types of conduit accessories are attached to threaded conduits and unthreaded conduits, each with a threaded connection port. and,
It is necessary to prepare one with a circular hole suitable for receiving the outside diameter of the pipe and to use the appropriate one during construction, which makes it economical in manufacturing, difficult in terms of product storage management, and complicated in construction work. It had the following disadvantages.

The purpose of this invention is to provide a connection structure for conduit accessories that can be commonly applied regardless of whether the connecting end of the conduit is threaded or not. It is in.

In order to achieve the above-mentioned object, this invention specifically provides a metal conduit having a threaded portion at the connecting end, a metal conduit having no threaded portion at the connecting end, and and various conduit fittings each having a connection port for selectively connecting each metal conduit to each other, and the conduit fittings extend from the connection port entrance to a predetermined depth position. A connecting portion of a metal conduit, which has a hole portion having a diameter that accepts the outer diameter of the conduit, and has a threaded hole portion that is screwed into the screw of the metal conduit from the predetermined depth position. It is a structure.

Hereinafter, the structure of the connecting portion of the metal conduit accessory according to this invention will be explained in detail based on a specific example shown in the drawings.

1A and 1B are schematic cross-sectional views showing the basic configuration of this invention, and in particular, FIG. 1A shows the connection relationship between a non-threaded conduit 1A and a conduit accessory 2. FIG. 1B shows the connection relationship between a threaded conduit 1B and a conduit accessory 2. The conduit 1 has a diameter D in an unthreaded state as shown in FIG. 1A, and has a threaded portion 3 within an axial distance l as shown in FIG. 1B. There is.

On the other hand, the electrical conduit accessory 2 is provided with a connection port 4 for connecting the electrical conduit 1, and has an outer diameter D of the metallic electrical conduit 1 from the inlet end to a depth position P at a distance L. It has a hole portion 5 having a diameter D' for receiving the metal conduit 1, and a screw hole portion 6 which is screwed into the threaded portion 3 of the metal conduit 1 from the point P. Diameter of the hole portion 5 in the connection port 4 of the conduit accessory 2
The inner diameter d of the screw hole 6 with respect to D' is designed so that D'>d. As a result, Figure 1A
As shown in the figure, the stepped portion 7 serves as a stopper when an unthreaded electrical conduit is inserted. The electrical conduit 1A inserted in this manner is fixed to the accessory 2 by a tightening screw 8 provided at a position corresponding to the hole portion 5 of the electrical conduit accessory 2.

On the other hand, as shown in FIG. 1B, the threaded conduit is connected by threading the threaded portion 3 provided on the conduit 1 to the threaded hole 6 provided in the conduit accessory 2, and It can be tightened and fixed with a tightening screw 8. Therefore, even if the axial distance l of the threaded portion 3 provided in the conduit 1 is shorter than that of the conventional one, a sufficient connection effect can be obtained, and the strength of the connection part especially in thin-walled conduit can be improved. This is something that can be compensated for. Furthermore, by adopting the above-mentioned configuration, that is, the tightening configuration using the tightening screw 8 in addition to the screw connection, it is possible to temporarily tighten the piping, and especially in the case of a coupling, there are advantages such as the ability to omit tightening with a lock nut. have

According to the structure of the connection part of the conduit accessory of this invention having the above configuration, first, regardless of the form of the connection part of the conduit (threaded or not), conduit accessories for each purpose are prepared. If you keep them in place, they can be used in any case, making it economical to manufacture conduit accessories, reducing the quantity in product storage management, and eliminating the complexity of construction work due to different selections. It can be said that it is extremely effective and practical in these respects.

[Brief explanation of drawings]

The drawings show a specific example of the connection structure for metal conduit accessories according to this invention,
Figures 1A and B are schematic sectional views showing the basic structure of this invention, Figures 2A and B are perspective views and sectional views of the main parts of a round exposed box to which this invention is applied, and Figure 3. and FIG. 4 is a schematic perspective view of an exposed switchbox and coupling according to another embodiment of the invention. 1...Conduit tube, 2...Conduit tube accessories, 3...Conduit tube screw part, 4...Connection port, 5...Insertion circular hole, 6...Screw hole,
7...Step part, 8...Tightening screw.

Claims (1)

[Scope of utility model registration request] A metal conduit with a threaded part at the connecting end, and a metal conduit without a threaded part at the connecting end,
each conduit accessory provided with a connection port for selectively connecting the metal conduit to each other,
The conduit accessory has a hole portion having a diameter that accepts the outer diameter of the metal conduit from the connection port entrance to a predetermined depth position, and the conduit accessory has a hole portion having a diameter that accepts the outer diameter of the metal conduit from the connection port entrance to a predetermined depth position. A structure of a connecting part of a metal conduit accessory, characterized in that it has a screw hole part that is screwed into a screw of the metal conduit accessory.