JP2706003B2 - Integrated coating method for multiple cables - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for integrally covering a plurality of cables which can contribute to simplifying explosion-proof work and can withstand long-term use.

[0002]

2. Description of the Related Art Conventionally, cable glands of a pressure-resistant packing type have been used for terminating cables (cables, insulated wires, etc.) in explosion-proof construction. This pressure-resistant packing is made of rubber, and provides an explosion-proof property by closely contacting the surface of cables with the pressure-resistant packing. For example, as shown in FIG. 4, when the cables 2 are pulled into the explosion-proof structure device 1, the pressure-resistant packing type cable gland 4 is inserted into the explosion-proof structure special terminal box 3 through the special terminal box 3.
Is used to pull in the cables 2.
However, when there are a plurality of cables 2, it is not allowed to fix the plurality of cables 2 with one pressure-resistant packing, and it is necessary to provide a plurality of holes and fix each one with the pressure-resistant packing. However, this method is not performed because it is troublesome. Therefore, when a plurality of cables 2 and insulated wires are subjected to explosion-proof treatment and drawn into the device 1 having an explosion-proof structure, a pressure-resistant fixed type retraction system and a sealing fitting type retraction system are adopted, respectively. As shown in FIG. 5, in the pressure-resistant fixed type retraction method, a cable 5 in which a plurality of insulated wires are bundled and covered is made to enter a housing 6 attached to a dedicated terminal box 3 and fixed. The insulated wires are exposed from the end of the cable 5, and the sealing compound 7 is injected and filled near the ends of the cables 5. On the other hand, as shown in FIG. 6, the sealing fitting type retraction method is such that a plurality of insulated wires 9 pass through the inside of the sealing fitting body 8 attached to the dedicated terminal box 3, and the sealing compound is inserted into the sealing fitting body 8. 7 is injected and filled.

[0003]

However, in the retracting method as described above, the exclusive terminal box 3 is required,
Also, when the sealing compound 7 was injected, special skills were required. Further, the moisture absorption of the sealing compound 7 often causes a decrease in insulation at the terminal portion. SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and has been made in view of the above-mentioned problems, and has been made of a method for integrally covering a plurality of cables, which has improved explosion-proof construction, has improved insulation properties and durability, and can maintain explosion-proof properties for a long time. The purpose is to provide.

[0004]

In order to solve the above-mentioned problems, the present invention provides a packing box mounted on an explosion-proof device.
When pulling and wiring multiple cables via
Terminal with multiple core wires protruding with cables bundled together
A resin hollow tube from the cable end to surround the
Insert the sheath material into this resin hollow tube,
After curing it, remove the cable end or near the end.
Coke between the cable and the cured sheath material
To remove the resin hollow tube,
The outer diameter of the terminal portion or the vicinity of the terminal portion is a fixed size,
In the packing box, use a pressure-resistant packing
So that it can be tightened and held with a specified tightening force.
I made it. Further, the present invention provides an apparatus for controlling an outer diameter of the plurality of cables.
As a means to make
A metal hollow tube is placed around the end of
Injection hardening can be performed.

[0005]

[Function] A part of a plurality of cables or the periphery of a terminal portion is integrally coated with a sheath material to form a fixed outer diameter, so a pressure-resistant packing of one size adapted to the fixed diameter. You only need to prepare. In addition, the sheath material ensures the seal between the outer sheath of the cable end portion and the core wire, and prevents the flow of flammable gas and the like between the core wire and the outer sheath of the cable. It is possible to reliably prevent an explosion accident at an ignition source in a dangerous area. When only pressure-resistant packing of a specific size is used, the relationship between the outer diameter of multiple cables covered with the sheath material and the pressure-resistant packing is always constant, so the appropriate tightening amount of the pressure-resistant packing can be specified by the mark on the tightening member. In addition, it is possible to easily confirm the construction work, and to make explosion-proof construction reliable and simple. Therefore, it is possible to prevent the pressure packing from being excessively tightened, so that there is no concern about permanent deformation of the core wire due to excessive compression.In addition, since the part to be tightened with the pressure packing is made into a double sheath, there is insulation and durability. Explosion-proof performance can be maintained for a long time.

[0006]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a sectional view showing a method for integrally covering a plurality of cables according to the present invention. In FIG. 1, reference numeral 10 denotes a plurality of cables that are pulled through a packing box 12 mounted on an explosion-proof device 11. These cables 10
An airtight sheath portion 14 formed by curing a sheath material made of, for example, a thermosetting resin (epoxy resin) is provided at the protruding terminal portions of the plurality of core wires 13. In addition to the cable 10, the present invention can be applied to an insulated wire. Outer diameter L of each of the plurality of cables 10
Varies depending on the cable. On the other hand, the diameter L of the hermetic sheath portion 14 that integrally covers the cable 10
₁ is set to a fixed length (see FIG. 2). The terminal portion of the cable 10 is introduced through a pressure-resistant packing 15 of a packing box 12 screwed to the explosion-proof device 11, and further, a gland 16 is screwed into the packing box 12, and the The pressure-resistant packing 15 is brought into contact with the pressure-resistant packing 15 and is fixed and held by the clamp member 18.
Thereby, it is configured to be clamped and held. Here, a procedure for forming the hermetic sheath portion 14 will be described. As means for forming the hermetic sheath portion 14, as shown in FIG. 3, a plurality of core wires 13 have a fixed inner diameter L ₁ [L ₁ > Σ (outer diameter L of the cable 10)] at the end of the cable 10. A resin hollow tube 19 is arranged, a sheath material 20 made of an epoxy resin is injected and cured with a curing agent, and a caulking process is performed between the cable 10 and the cured sheath material 20 to form the resin hollow tube. 19 is to be removed. In addition, as a substitute for the resin hollow tube 19, a metal hollow tube can be applied. In any case, by previously determining the inner diameter L ₁ of the resin hollow tube 19, so as determine the outer diameter of the airtight sheath portion 14 to a predetermined length.

According to integrally coating treatment method of a plurality cables as described above, since the outer diameter a constant diameter L ₁ in the airtight sheath portion 14 formed by coating a plurality of cables 10 the terminal unit, the constant one sized to the diameter L ₁ of it Sonaere only flameproof packing 15. In addition, the hermetic sheath 14 ensures the seal between the jacket of the terminal portion of the cable 10 and the core wire 13 and prevents the flow of flammable gas or the like between the core wire 13 and the cable 10 jacket. Therefore, an explosion accident at an ignition source in a non-hazardous area can be reliably prevented. When the only pressure-resistant packing 15 of a particular size, since the relationship between the outer diameter L ₁ and pressure-resistant packing 15 of a plurality of cables 10 covered by the sheath material is always constant, the proper tightening of pressure-resistant packing 15, e.g., fastening member Can be easily identified by the mark, the explosion-proof work can be made reliable and simplified. Therefore, since the pressure-resistant packing 15 can be prevented from being excessively tightened, there is no fear of permanent deformation of the core wire 13 due to excessive compression. In addition, the portion to be tightened by the pressure-resistant packing 15 is double-sheathed, and insulation and It is durable and can maintain explosion-proof performance for a long time.

[0009]

As described above, according to the present invention, explosion-proof construction costs can be reduced and the construction can be simplified. A plurality of cable terminals and a cable sheath are
It has insulation and durability, and can maintain explosion-proof performance for a long time. Since the amount of tightening of the pressure-resistant packing, which is an important step in explosion-proof construction, can be made substantially constant, it is possible to avoid inconvenience due to overtightening. Since you only need to prepare a pressure-resistant packing of a specific size,
The relationship between the outer diameter of a plurality of cables covered with the sheath material and the pressure-resistant packing is always constant, and it is possible to visually check the appropriate tightening amount, so that it is easy to check the tightening after construction. . In addition, since the pressure-resistant packing is only of a specific size, construction maintenance such as replacement of the packing is also easy.

[0010]

[Brief description of the drawings]

FIG. 1 is an explanatory view showing a state in which a method for integrally covering a plurality of cables according to the present invention is applied to an explosion-proof device.

FIG. 2 is an explanatory sectional view of the cable terminal shown in FIG. 1;

FIG. 3 is a diagram illustrating a step of forming a coating on a cable terminal portion according to the present invention.

FIG. 4 is a diagram showing a state in which a plurality of cables are connected to an explosion-proof device in the related art.

FIG. 5 is a diagram illustrating an example of a conventional method for drawing a plurality of cables into an explosion-proof device.

FIG. 6 is a diagram illustrating an example of a conventional method for drawing a plurality of insulated wires into an explosion-proof device.

 ──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Yukihiro Tanaka 3-18-3, Chuohonmachi, Adachi-ku, Tokyo (72) Inventor Kiyomasa Aonuma 1-17-6-103 Takasu, Chiba City, Chiba Prefecture (56) References JP-A-60-249815 (JP, A)

Claims (2)

(57) [Claims] 1. A packing box mounted on an explosion-proof device.
When pulling and wiring multiple cables through
Terminals with multiple core wires protruding with cables bundled
A resin hollow tube is inserted from the cable end to surround the
The sheath material is injected into this resin hollow tube and
To cure the cable end or near the end.
Cover the cable between the cable and the cured sheath material.
To remove the resin hollow tube,
The outer diameter near the end or near the terminal is a fixed size,
In the packing box, use a pressure-resistant packing
And a method of integrally covering a plurality of cables, wherein the method is capable of being held tight by a predetermined fastening force . 2. The apparatus according to claim 1, wherein said plurality of cables have a constant diameter.
As a means to make
A metal hollow tube is placed around the end to inject the sheath material.
2. The method for integrally covering a plurality of cables according to claim 1, wherein the coating is performed.