JPH0531366B2 - - Google Patents

Description

Detailed Description of the Invention (Industrial Field of Application) The present invention relates to a metal duct material splicing device, and relates to a metal duct material having a substantially groove-shaped cross section and used for collectively supporting insulated wires and various cables. Improved metal duct material that allows for simple and quick connections at the installation site, as well as ensuring electrical continuity between metal duct materials that have been treated with a surface treatment film for weather resistance and rust prevention. Regarding the method of joining.

(Prior Art) Conventionally, metal wires with a width of 5 cm or less, called raceways, or metal ducts with a width of more than 5 cm, which have a substantially groove-shaped cross section, have been used in various types and structures. Many of them have special features that take into consideration weather resistance, rust resistance, salt resistance, moisture resistance, chemical resistance, etc., in order to cope with changes in the environment at the installation site. Surface treatment has been applied. Examples include melamine baking coating, powder coating and electrodeposition coating (epoxy resin coating) with excellent anti-rust properties, and other synthetic resin coatings.

However, these special surface treatment films do not have conductivity, and in particular, there is no conductivity between the metal duct materials to which the surface treatment films are connected and installed, so electrical conductivity may occur in the insulated wires and cables that support the wiring. This was extremely inconvenient because leakage current could not be avoided.

Therefore, a connecting device has been proposed in which the surface treatment film is penetrated to achieve mutual conductivity between the connecting members (see Japanese Utility Model Publication No. 5757/1983). In this device, a needle protrusion formed on the abutting surface of a nut is brought into contact with the surface treatment film, and the needle protrusion pierces the surface treatment film to establish an electrical connection through the nut.

Furthermore, an electronic device casing has been devised in which the surface coated with a surface treatment film is folded back to expose the back surface of the metal base, and this back surface is contacted with a bolt or the like to achieve electrical conductivity. (See No. 54-51821).

In addition, there is an invention described in Japanese Patent Application Laid-Open No. 150695/1983 that connects connecting members easily and reliably. The object of this invention is to simplify and ensure the connection work of cable racks by overlapping and connecting the ends of the cable racks.

(Problem to be Solved by the Invention) In the former type of connecting device, the needle protrusion breaks through the film of paint, etc., but with recent advances in paint technology, it is possible to increase the film thickness. In addition, many coatings with high hardness on the surface are also used. This makes it difficult for the needle protrusion to break through such a thick film type or highly hard coating, and there is a possibility that sufficient electrical contact may not be obtained.

Moreover, since this connecting device uses a nut provided with a needle protrusion, a lot of processing is required for the connecting device. That is, a concave portion is formed on the surface of the connecting member located inside of the members to be overlapped and connected, and the nut is fixed. On the other hand, a bolt is inserted from the surface of the outer member into the inside, and this bolt is screwed into a nut inside the member. The tip of the bolt presses against the concave portion of the connecting member located inside, thereby pressing the needle protrusion of the nut against the inner side surface of the member located on the outside. Therefore, to use this coupling device, set the nut in the recess of the coupling member, insert the coupling member into the member in this state, and then insert the bolt from the surface of the member toward the nut inside the member. It takes a lot of work to insert the . As a result, as a connecting device for metal duct materials that requires connecting a large number of members, the work is extremely troublesome and the connecting work is hindered.

In addition, since the point where the needle protrusion pierces the coating film is the inner surface of the connecting member, it is difficult for the operator to judge whether or not sufficient conduction has been achieved.

On the other hand, in the case of an electronic device, the insulating coating is limited to the front side, but with metal duct materials, the insulating coating is removed from both sides. It is not possible to expose the metal base surface. Moreover, the housings of electronic devices require curling to fold back the covering surfaces at each connection point, which is too labor-intensive when used as a means of connecting a large number of components such as metal duct materials. It was hot.

In the latter case, which connects cable racks to each other, the ends of the cable racks are overlapped with each other, and
Although it is possible to reduce the number of connecting parts and rationalize the connection method by connecting multiple mounting bolts, it is not possible to electrically connect cable racks or metal duct materials to each other.

Therefore, the present invention was made to solve the problems that existed in the past.It is possible to easily connect metal duct materials to each other and at the same time realize reliable electrical continuity.Moreover, it has excellent corrosion resistance and electrical continuity. The purpose of the present invention is to provide a method for joining metal duct materials that can maintain the quality for a long period of time.

(Means for Solving the Problems) In order to solve the above-mentioned problems, the present invention provides a splicing method in which a non-conductive surface treatment film is applied to the interconnection portions of metal duct materials. The fastening means is forcibly fitted into the bolt insertion holes of the ends of the overlapped metal duct materials to enlarge the bolt insertion holes and remove the surface treatment film of the inserted portions. A conductive bolt with a square root that breaks, and a conductive nut with a screw-shaped breakage protrusion that pushes the surface treatment film that comes into pressure contact with the bolt as it is screwed into the bolt. It is characterized by consisting of.

(Function) In the method of joining metal duct materials of the present invention,
When connecting metal duct materials to each other at a site where metal duct materials are to be laid, the surface treatment film applied to the metal duct materials is ruptured at the connection site to establish electrical continuity between the metal duct materials. .

At this time, the ends of the metal duct materials are connected in an overlapping manner using a fastening means that screws the ends together. That is, joint bolts,
When a fastening means equipped with a nut is interposed at a connection site between metal duct materials, the surface treatment film is ruptured by the joint bolt being penetrated or by the nut being screwed into the joint bolt.

Then, by breaking the surface treated film in one of the metal duct materials, an electrical route is formed directly or indirectly through the fastening means interposed between the conductive fabrics.

As a result, electrical continuity between the metal duct materials is achieved, avoiding leakage currents that may occur in the insulated wires and cables that support the wiring.

(Example) Hereinafter, an example of the present invention will be described with reference to the drawings.

The reference numeral 1 shown in the figure is a metal duct material that is connected to each other by the device of the present invention, and as shown in the figure, basically, the cross-section of parallel left and right side plates facing each other connected by a bottom plate is approximately It has a groove shape and is used as a metal wire called a raceway with a width of 5 cm or less, or as a metal duct with a wider width. This metal duct material 1 has a surface treatment film 2 applied to both the left and right side plates and the bottom plate to improve weather resistance, rust resistance, salt resistance, moisture resistance, chemical resistance, etc. This surface treatment film 2
As in the past, these are melamine baked coatings, powder coatings, electrodeposition coating finishes (epoxy resin coatings), and other synthetic resin coatings.

Therefore, when the metal duct materials 1 configured as described above are connected to each other, the connection is performed via the conductive fastening means 10 that breaks the surface treatment film 2.

That is, the fastening means 10 has the ends of the metal duct material 1 overlapped with each other, and is forcibly fitted into the bolt insertion holes 11 of the overlapped ends to enlarge the bolt insertion holes and thereby tighten the insertion portion. A conductive joint bolt 12 is provided with a square root 13 that breaks the surface treatment film, and a screw-shaped rupture protrusion that pushes the surface treatment film 2 into pressure contact with itself as it is screwed into the joint bolt 12. A conductive nut 14 having a diameter 19 formed therein is provided.

Therefore, the screwed parts, specifically the joint bolt 12 and the nut 14 screwed into the joint bolt 12, break the surface treatment film 2 and come into contact with the fabric, causing the end of the conductive metal duct material 1 to break. Create electrical continuity between fabrics. At that time, the metal duct material 1 on one side and the metal duct material 1 on the other side are electrically connected to each other by interposing the screwed parts, and the electrical continuity is established directly by the screwed parts or by other metal ducting materials interposed as necessary. It is indirectly acted upon by a conductive member.

Next, specific structural examples of the fastening means 10 will be described as Examples 1 to 6.

Embodiment 1 As shown in FIGS. 1 to 6, the ends of the metal duct material 1 are overlapped with each other, and one of the ends is connected with a conductive joint bolt 12 inserted through the overlapped ends. The surface treatment film 2 of the metal duct material 1 is broken, and the surface treatment film 2 of the other metal duct material 1 is broken by the nut 14 screwed into the joint bolt 12.

Specifically, metal duct materials 1 to be connected to each other
A step connection part 3 is formed by bending the end part inwardly or outwardly to have a step equal to the thickness of the wall. Overlap the other cape end, still in shape, and secure with screws.

At this time, two circular bolt insertion holes 11 are formed in each joint portion at the end of the metal duct material 1.
Open the hole. As shown in the figure, this bolt insertion hole 11 is provided in the left and right side plates of the metal duct material 1, and the joint bolt 12 is provided in the metal duct material 1.
Assuming that the round-shaped head is located inside the
Prevent damage to the insulated wires and cable sheathing.

When screwing, a bolt insertion hole 1 is opened to match the position of the step connection part 3 and the cape end part.
1, and insert the connecting bolt 12 through the bolt insertion hole 1.
While breaking the surface treatment film 2 on the inner edge of the joint bolt 12, a nut 14 is screwed into the joint bolt 12.

The threaded base of the joint bolt 12 has a cross section having a diagonal line longer than the inner diameter of the bolt insertion hole 11, which is inserted into the bolt insertion hole 11 in one of the metal duct members 1 and bit into the inner edge thereof. A substantially rectangular root portion 13 is formed. Joint bolt 12
As shown in the figure, a nut 14 with a washer is screwed into the nut 14, and a surface treatment film 2 is applied to the back surface of the nut 14, which comes into pressure contact with the surface of the other metal duct material 1 as it is screwed into the connecting bolt 12. A breaking protrusion 15 is formed to break. This breaking protrusion 1
Numeral 5 is formed on the back surface of the nut 14 to break the other metal duct material 1, which is also provided with a similar surface treatment film 2.

Although not shown in the drawings, the breaking protrusion 15 may be formed by knurling, and the point is that the surface treatment film 2 may be broken as the screw is screwed in to contact the surface of the fabric.

According to this embodiment, when the nut 14 is screwed into the joint bolt 12 inserted into the bolt insertion hole 11, the square root 13, which is larger than the inner diameter of the bolt insertion hole 11, bites into the bolt insertion hole 11. (See FIG. 2) As shown in FIG. 2, the surface treatment film 2 that was also applied to the inner edge of the bolt insertion hole 11 is broken, and electrical continuity is obtained. That is, one metal duct material 1, joint bolt 12, nut 1
4. An electrical route for the other metal duct material 1 is formed.

In this embodiment, the square root part 13 of the connecting bolt 12 does not have a substantially rectangular cross section as shown in the drawings, but may have a triangular, pentagonal or more polygonal shape, which is arbitrary.

Embodiment 2 In FIG. 5, the square root portion 1 of the joint bolt 12
A concave or convex recess 16 is formed on the circumferential surface of the joint bolt 14 in the length direction of the joint bolt 14, and is formed by hettering, knurling, or wing-shaped punching, for example, as shown in the figure. Shape it into a straight vertical groove like this. Other structures are Example 1
Or it is the same as 2. Note that the square root portion 15 is
As shown in Figure 5, the diameter is the same from the tip of the thread to the head, or as shown in Figure 5, the diameter gradually increases from the tip of the thread to the head. In this case,
Smooth insertion into the bolt insertion hole 11 can be achieved. In addition, as shown in Fig. 5, there are four triangular blade-shaped protrusions at the base of the thread that gradually become wider as the tip of the thread reaches the head.
1. The force of biting into the surface treatment film 2 at the inner edge of the joint elongated hole 13 may be increased.

Example 3 In FIG. 6, although it is the same as Example 1,
However, a vertical groove 17 having a substantially serrated cross section is formed on the circumferential surface of the square root portion 13 of the joint bolt 12. This vertical groove 17 is connected to the connecting bolt 12.
It may be either straight along the length direction or curved.

According to Examples 2 and 3, the breaks in the surface treatment film 2 on the inner edge of the bolt insertion hole 11 are divided into smaller pieces to further ensure electrical continuity, and according to the curved vertical groove 17 of Example 3, When the joint bolt 12 is slightly rotated when screwed into the joint bolt 14, the surface treatment film 2 is further broken.

Embodiment 4 In FIG. 7, the square root portion 13 of the joint bolt 12 is the same as the above-mentioned embodiments, but
The tip of the screw has a tapered surface that gradually becomes larger in diameter as it reaches the head. according to this,
When screwing into the nut 14, the square root portion 13 quickly and smoothly enters the bolt insertion hole 11, making it easy to break the surface treatment film 2 on the inner edge thereof.

Embodiment 5 In FIGS. 8 and 9, the joint bolt 14
The back of the head is metal duct material 1 or fitting 1
2, the surface treatment film 2 is broken at the contact portion on the back surface of the head.
That is, as shown in FIG. 8, a ring-shaped broken ridge 18 is formed along the periphery of the head at the abutting portion on the back surface of the head, or as shown in FIG.
It may be a broken protrusion 19 with an uneven surface formed on the back surface of the head.

Example 6 In Fig. 10, the metal duct material 1 to be connected
A pair of connecting bolts 12 that are inserted through a pair of front and rear bolt insertion holes 11 are connected and integrated with a connecting board 21 that is installed across the bolt insertion holes 11, and the connecting board 21 is provided with a surface treatment film 2. A sharp breaking protrusion 22 is formed to break the material.

This is done by arranging the connecting board 21 so as to span over the bolt insertion holes 11 that match each other in the metal duct materials 1 to be connected, and by inserting joint bolts 12 into each of the metal duct materials 1. Te Natsu 14
As the joint bolt 12 is screwed in, the joint bolt 12 is drawn, and the breaking protrusion 22 bites into the surface of the metal duct material 1 and breaks the surface treatment film 2 on the surface of the metal duct material 1.

(Effects of the Invention) As described above, the present invention can simultaneously connect metal duct materials to each other and ensure electrical continuity therebetween.

That is, instead of the method in which the needle protrusion breaks through a film such as paint as in the conventional connecting device, the ends of the metal duct materials are connected by overlapping each other,
The electrically conductive conductive material is forcibly fitted into the bolt insertion hole 11 that matches between the ends of the metal duct material, expands the bolt insertion hole 11, and has a square root portion 15 that breaks the surface treatment film 2 at the inserted portion. By using the joint bolt 12, the joint bolt 12 is firmly fixed in the bolt insertion hole 11, and the joint bolt 12 is prevented from spinning idle.
The tightening force of the nut 14 can be made extremely high. Therefore, the insufficient conduction effect due to point contact, such as electrical conduction through the needle protrusion formed on the contact surface of the conventional nut, has been improved to a reliable conduction effect.

Furthermore, by using a fastening means using a conductive nut 14 formed with a screw-shaped breakage protrusion 19 that pushes the surface treatment film 2 that presses against itself as it is screwed into the joint bolt 12. , the surface treatment film 2 can be pushed around the nut 14, and the metal cloth of the metal duct material and the fracture protrusion 19 are surely in contact over a wide area. Further, the surface treatment film 2 pressed around the nut 14 protects the area around the nut 14 and the peeled metal fabric. As a result, the clothing treatment after establishing electrical continuity can be performed at the same time, eliminating the risk of loss of electrical conductivity due to rust generated from exposed parts of the metal material.

Furthermore, while the square root portion 13 of the connecting bolt 12 expands the bolt insertion hole 11 and is strongly tightened,
The broken protrusion 15 of the nut 14 can be sufficiently pressed against the surface of the metal duct material. Therefore, even thick or hard coatings can be reliably removed.

Moreover, since the metal duct materials are overlapped, the joint structure is simplified and the working time is shortened.

Furthermore, by forming an electrical route between one metal duct material, joint bolts, and nuts, and the other metal duct material, there are fewer intervening conductive parts, which further improves the reliability of electrical continuity.

[Brief explanation of the drawing]

The drawings show embodiments of the present invention. Fig. 1 is an exploded perspective view of Embodiment 1 of the present invention in use, and Fig. 2 shows the fracture of the surface treatment film at the bolt insertion hole. is a front view of the main part, that is a sectional view of the main part before breaking, Fig. 3 is a sectional view of the connected state, Fig. 4 is a side view of the nut, and Figs. Perspective view,
FIG. 6 is a perspective view of a joint bolt in Example 3;
FIG. 7 is a perspective view of a joint bolt in Example 4;
8 and 9 are perspective views of a joint bolt in the fifth embodiment, and FIG. 10 is an exploded perspective view of the sixth embodiment. 1...Metal duct material, 2...Surface treatment film, 3...
...Step connection portion, 10... Fastening means, 11... Bolt insertion hole, 12... Joint bolt, 13... Square root, 14... Nut, 15... Fracture protrusion, 16...
... Biting part, 17 ... Vertical groove, 18 ... Fractured ridge, 1
9... Breaking protrusion, 20... Breaking ridge, 21... Interlocking board, 22... Breaking protrusion.

Claims (1)

[Claims] 1. A fastening means is provided between the connecting parts of metal duct materials coated with a non-conductive surface treatment film, and this fastening means is provided with a bolt insertion means between the ends of the overlapping metal duct materials. A conductive connecting bolt with a square root that forcibly fits into the hole to expand the bolt insertion hole and rupture the surface treatment film of the inserted part, and a surface that comes into pressure contact with the connecting bolt as it is screwed into the connecting bolt. A fitting for a metal duct material, characterized in that it consists of a conductive nut having a screw-shaped fracture protrusion that pushes a treated membrane around itself.