JPH062296Y2 - Cable clamp device for explosion-proof cable gland - Google Patents

Description

[Detailed Description of the Invention] [Industrial field of application] The present invention relates to a cable clamp device for an explosion-proof cable gland used for guiding a cable to a flameproof box.

[Conventional technology]

In this type of device, as shown in Japanese Utility Model Publication No. 57-8230, the pulling cable is clamped and fixed to one side of the inner peripheral surface of the packing land by a pressing piece.

[Problems to be solved by the invention]

As described above, when the cable is fixed to the packing land by the pressing piece, the cable is pressed and fixed to one side of the inner peripheral surface of the packing land, the cable is not fixed to the center of the packing land, and the center of the cable is It is out of the center of Packing Land. As a result, an uneven load is applied to the packing part of the cable adjacent to the clamp part of the cable, and the uniform pressure contact between the cable and the packing part is impaired, and the explosion-proof property, waterproof property, and airtightness are not maintained. There was a flaw that made it worse.
The present invention aims to eliminate the above defects.

[Means for solving problems]

In order to achieve the above object, the present invention is a device for fixing a cable 8 to a tubular packing land 5 into which a cable 8 is inserted and arranged, wherein a concentric large diameter portion 5b is formed in an inner diameter portion of the packing land 5. A plurality of axial grooves 6b are formed on the peripheral wall of the large-diameter portion 5b, projections 6a projecting on concentric circles are formed on the inner peripheral surface of the peripheral wall of the groove forming portion, and the end portion of the peripheral wall is formed. A clamp ring 6 made of an elastic plastic tube having an inclined surface 6c formed on the outer peripheral surface is arranged, a screw portion is formed on the packing land 5, and a locking surface 7a for the clamp ring 6 is formed on the screw portion. The clamp cap 7 which can be rotated is screwed, and the tapered wall 5a is formed on either one of the vertical wall surface of the large diameter portion 5b and the locking surface 6a.

[Action]

In the above configuration, the clamp cap 7 is screwed into the thread portion of the packing land 5 to
When the clamp ring 6 in the large-diameter portion 5b is clamped between the vertical wall of the large-diameter portion 5b and the locking surface 7a of the clamp cap 7, the clamp ring guides the clamp ring 6 to the tapered wall 5a. Then, the inner diameter portion is concentrically reduced in diameter, and the protrusion 6a of the inner diameter portion is crimped to the cable 8 inserted and arranged in the packing land 5, and the cable 8 is packed at the center of the packing land 5 via the clamp ring 6. It is fixed to the ground 5.

〔Example〕

Hereinafter, the configuration of the present invention will be described in detail with reference to the embodiments shown in the accompanying drawings.

Reference numeral 1 denotes a cylindrical body of an explosion-proof type cable gland, on which a large diameter portion 1b and a small diameter portion 1a are formed, and the large diameter portion 1
A groove is formed on the outer periphery of b, and a rubber ring 12 is formed in the groove.
Is fitted. A male screw 1d is formed on the outer peripheral portion of one end of the main body 1, and a male screw 1c for attaching to a flameproof explosion-proof box (not shown) is formed on the outer peripheral portion of the other end. Reference numeral 2 denotes a tubular packing case slidably inserted in the main body large diameter portion 1b. A tubular rubber packing 3 is inserted into the inner diameter portion of this. One end surface of the packing case 2 is locked to a vertical surface annularly formed on the inner diameter portion of the main body 1. A taper surface 2a is formed on the vertical wall of the packing case 2. Reference numeral 5 is an annular packing land, and the packing case 2 is provided on the outer peripheral portion on one side of the hexagonal nut-shaped collar portion 5c.
A male screw portion for screwing into the female screw portion is formed, and a male screw 5d for screwing with the clamp cap 7 is formed on the outer peripheral portion on the other side. Reference numeral 6 denotes a tubular clamp ring made of a cylindrical elastic plastic, in which a plurality of grooves 6b are formed in the peripheral wall in the axial direction at equal intervals, and the inner peripheral wall on one end side of the clamp ring 6 projects concentrically in the central direction. The protruding portion 6a is formed. Further, an inclined surface 6c that is inclined toward the center of the clamp ring 6 is formed on the outer peripheral wall at one end of the clamp ring 6. A large-diameter portion 5b having a diameter larger than the inner diameter of the gland 5 is formed on one side of the packing land 5, and a tapered wall surface 5b is formed on the inner peripheral wall of the large-diameter portion 5b. Reference numeral 7 denotes a bottomed cylindrical clamp cap, the outer shape of which is formed into a hexagonal nut shape, and a female screw portion for screwing with the male screw portion 5d of the packing land 5 is formed. A hole for loosely fitting the cable 8 is formed in the bottom of the clamp cap 7, and the inner wall surface of the bottom constitutes a locking surface 7a for pressing the clamp ring 6. Reference numeral 9 denotes a coupling, which has a flange portion 9a at one end and is fitted and fixed to a flexible protection tube (not shown) in which the cable 8 is incorporated. Reference numeral 10 is a union, and a ridge 10a is formed at one end thereof so as to engage with the flange portion 9a of the coupling 9, and a rubber O-ring is fitted in a circumferential groove formed in the ridge 10a. There is. A screw hole 13 is formed in the other end of the union 10 in the thickness direction, and a female screw portion for screwing the male screw 1d of the main body 1 is formed on the other inner diameter portion of the union 10. .

Next, the operation of this embodiment will be described.

First, the outer peripheral surface of the protective tube containing the cable 8 is fitted to the inner peripheral surface of the coupling 9, and the cable 8 is fitted to the rubber packing 3 and loosely fitted to the packing land 5 as shown in FIG. . Next, the clamp cap 7 is screwed into the packing land 5 using a rotating tool, and both ends of the clamp ring 6 are pressed by the locking surface 7a of the clamp cap 7 and the tapered wall 5a of the packing land 5. Due to this clamping force, the protrusion 6a of the clamp ring 6 is guided by the tapered wall 5a and is deformed concentrically in the central direction.
The inner diameter of a is reduced and the protrusion 6a is crimped onto the cable 8, and the cable 8 is fixed to the center of the packing land 5 via the clamp ring 6. Next, packing land 5
The hexagonal collar portion 5c is used to screw into the packing case 2 with a rotating tool, and the end surface of the packing land 5 is pressed against the rubber packing 3 via the washer 4. By this pressure contact force,
The rubber packing 3 is deformed, its central space portion shrinks in the axial direction of the main body, and the inner peripheral surface of the rubber packing 3 is uniformly crimped to the outer peripheral surface of the cable 8 in the packing case 2.
The outer peripheral surface of the rubber packing 3 is pressure-bonded to the inner peripheral surface of the packing case 2. By the above operation, a terminal fitting including the coupling 9, the packing land 5, and the packing case 2 is formed at one end of the protective tube containing the cable 8. Of course, the cable 8 extends a predetermined length from one end of the terminal fitting, that is, one end of the packing case 2.

Next, the work of connecting the terminal fitting of the cable protection tube to the main body 1 that is screwed into the screw hole of the flameproof box will be described.

First, the tip of the terminal fitting, that is, the outer peripheral surface of the packing case 2 is fitted to the main body 1. Next, the union 10 is screwed into the screw on the outer peripheral portion of the main body 1, and the ridge 10a of the union 10 is brought into pressure contact with the collar portion 9a of the coupling 9, and then the screw hole 13
The union 10 is fixed to the main body 1 by screwing a screw into.
As a result, the tip end surface of the packing case 2 is pressed against the vertical surface of the tube portion of the main body 1, and the terminal fittings 9, 5, 5 of the cable protection tube are attached.
2 is fixed to the main body 1. Cable 8 in the above terminal bracket
Is guided through the inside of the main body 1 to the electric equipment in the explosion-proof box and connected to it.

In the above embodiment, the cable 8 can be clamped before the packing land 5 is screwed into the packing case 2, so that the packing position of the cable 8 can be reliably positioned. Cable 8 is packing land 5 as before.
If the cable is eccentrically fixed, it is necessary to press the packing against the cable before fixing the cable, which results in inaccurate positioning of the packing position of the cable. Further, in the conventional device, in moving, when the cable was bent or pulled, a shearing force acted on the cable in contact with the side end of the clamp, which sometimes damaged the cable. In this embodiment, the tightening force is evenly applied to the outer circumference of the cable, and the cable 8 is fixed to the center of the packing land 5, so that the cable can be prevented from being damaged.

〔effect〕

Since the present invention is constructed as described above, the cable can be firmly fixed to the center of the packing land.

[Brief description of drawings]

1 is a sectional view, FIG. 2 is a sectional view, FIG. 3 is an external view, FIG. 4 is a left side view of the clamp ring, FIG. 5 is a right side view thereof, and FIG. 6 is a front view thereof. . 1 ... Main body, 2 ... Packing case, 3 ... Rubber packing, 5 ... Packing land, 5d ... Screw section, 6 ...
Clamp ring, 6a, projection, 6b, groove, 8 cable, 9 coupling, 10 union, 13
... screw holes

Claims (1)

[Scope of utility model registration request] 1. A device for fixing a cable 8 to a tubular packing land 5 into which the cable 8 is inserted and arranged, wherein a concentric large diameter portion 5b is formed in an inner diameter portion of the packing land 5, and the large diameter portion 5b is formed. In addition, multiple grooves 6 are formed on the peripheral wall in the axial direction.
b, a projection 6a is formed on the inner peripheral surface of the peripheral wall of the groove forming portion so as to project on a concentric line, and an inclined surface 6c is formed on the outer peripheral surface of the end of the peripheral wall. A clamp ring 6 is arranged, a thread portion is formed in the packing land 5, and a rotatable rotatable clamp cap 7 having a locking surface 7a for the clamp ring 6 is screwed into the thread portion. The taper wall 5 is provided on either one of the vertical wall surface of the large diameter portion 5b and the locking surface 6a.
A cable clamp device for an explosion-proof cable gland, characterized in that a is formed.