JPH0715308Y2 - Sleeve seal structure - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention relates to a seal structure on a dividing surface of a dividing sleeve which is divided into a plurality of pieces in a circumferential direction and is used for a cable connection box such as a communication cable and an optical fiber cable. It is a thing.

(Prior Art) FIG. 6 is a partially cutaway vertical sectional view of an example of a cable connection box such as a communication cable and an optical fiber cable.

In the drawings, (1) is a cable such as a communication cable and an optical fiber cable, and (2) is a core wire connecting portion of these cables. A sleeve (3) made of rubber or plastic is located to enclose the core wire connecting part (2) of the cable,
End plates (4) made of elastic material are attached to both ends thereof.

There are ridges (4a) on both sides of the outer peripheral surface of the end plate (4), and the space formed by the ridges (4a) and the inner peripheral surface of the end portion of the sleeve (3) is made of unvulcanized adhesive rubber tape. A sealing material (6) is formed by winding and maintains airtightness between the sleeve (3) and the end face plate (4).

Further, between the cable (1) and the inner peripheral surface of the end face plate (4), there is a seal material (7) formed by winding an unvulcanized adhesive rubber tape larger than the inner diameter of the end face plate (4). Sealing washers (5) for preventing the flow of the sealing material (7) are located on both sides of the sealing material (7) to keep the cable introduction portion airtight.

In the cable junction box as described above, the sleeve (3) is usually a divided sleeve divided into a plurality of pieces such as two in the circumferential direction.

FIG. 5 is an explanatory view of an example of a seal structure of the split surface of such a split sleeve. Gasket grooves (35a) (35b) with vertically asymmetrical rectangular cross sections having different depths are provided on the dividing surfaces of the dividing sleeves (3a) (3b) as shown in (a) of the figure. In the gasket groove (35a) (35b),
A vulcanized rubber gasket (8) with a circular cross section as shown in (b) of the figure is inserted, and the split surfaces of the split sleeves (3a) and (3b) are fastened as shown in (c) of the figure, so that the gasket ( 8) is compressed to maintain airtightness. The vertical compression rate of the gasket (8) when the divided sleeves (3a) and (3b) are fastened is usually 25 to 35%.

(Problems to be solved) In the above-described conventional sleeve seal structure, since a vulcanized rubber gasket having a circular cross section is used, vertical split asymmetric gasket grooves are provided in the split sleeves, which results in different gasket groove shapes. Two separate sleeves are required.

When the sleeve is fastened, the vertical compression ratio of the gasket is 25 ~
35%, which requires a large force to fasten the sleeve. Further, there is a problem that the contact points between the gasket and the inner wall of the gasket groove are two points at the top and bottom.

(Means for Solving the Problems) The present invention provides a sleeve seal structure that solves the above-described problems, and is characterized by a sectional surface of a divided sleeve divided into a plurality of portions in the circumferential direction. When a split sleeve is fastened with a trapezoidal shape, vertically symmetrical hexagonal gasket grooves that are vertically long are provided, and vertically symmetrical gaskets with protrusions on the upper and lower sides and on both sides are installed in the gasket grooves, and the sleeve is fastened. Occasionally, a plurality of contacts are symmetrically generated on the inner wall of the groove to maintain airtightness.

FIG. 1 is a cross-sectional view of a specific example of a gasket groove (a in the figure) and a gasket (b in the figure) in the sealing structure of the present invention, and FIG. 2 is a view of mounting the gasket in the gasket groove and fastening a split sleeve. It is sectional drawing of the state.

Vertically symmetric hexagonal gasket grooves (31a) (31b) with trapezoidal cross-sections are formed on the split surfaces of the split sleeves (3a) (3b) when the split sleeves (3a) (3b) are fastened. It has a shape.

The gasket (10) is made of vulcanized rubber,
Protrusions (11a) (11b) (12a) (1
2b), and a waist (13) is formed in the center of the body, forming a vertically symmetrical shape.

When the gasket (10) is mounted in the gasket grooves (31a) (31b) formed on the split surfaces of the split sleeves (3a) (3b) and the split sleeves (3a) (3b) are fastened, the gasket (10) Is its protrusion (11a) (11b) (12a) (12b)
In contact with the inner walls of the gasket grooves (31a) and (31b), and the contact points are at three upper and lower positions (a, b, c) (a ', b',
C '), a total of 6 points can be formed, and these contacts are positioned symmetrically in the vertical direction, thereby maintaining airtightness.

FIG. 3 shows another shape of the gasket (10). In this example, the protrusions of the gasket (10) are provided at four locations on the upper and lower sides and both sides. Points (a), (b), (c), (d), (e), and (a ') (b') at the top and bottom of the grooves (31a) (31b), respectively.
Contact points are formed at a total of 10 points of (C ') (D') (E).

In the present invention, the packing rate of the gasket with respect to the gasket groove cross-sectional area is set to 70 to 100%, the vertical compression rate of the gasket is set to 5 to 25%, and the horizontal compression rate is set to 3 to 20%. desirable.

(Operation) In the sleeve seal structure of the present invention described above, the split sleeves can have the same structure by making the gasket grooves vertically symmetrical.

Also, by making the gasket shape with multiple protrusions as shown in the figure, it is possible to make 6 or more contact points on the inner wall of the gasket groove and the gasket with a small compressive force. It is possible to maintain sufficient airtightness.

(Embodiment) As shown in FIG. 4, vertically symmetrical split sleeves (3a)
Insert the gasket (10) having a sectional shape as shown in FIG. 1 (b) into the gasket grooves (31a) and (31b) of (3b), and engage the guides (32a) provided on the sleeves (3a) and (3b). ) (32
When the buckle (33) for fastening the sleevele was engaged with b) and the split sleeves (3a) (3b) were fastened, and the following airtightness evaluation was performed, no gas leakage was found and good results were obtained.

Initial airtightness evaluation Filled gas pressure 1.0 kgf / cm ² gauge, heat cycle test Fill the same gas as above, −
100 cycles of 20 ° C to + 60 ° C (2 to 3 times / day) (Effect of device) As described above, according to the sleeve seal structure of the present invention, by forming the gasket groove vertically symmetrical,
The split sleeves can have the same structure, and the manufacturing cost can be reduced.

Also, by making the gasket shape with multiple protrusions, it is possible to make multiple contacts on the gasket inner wall and gasket with a small compressive force, and use a simple sleeve fastening jig to improve airtightness. Since it can be held, the workability of assembling is improved and the time can be shortened.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a cross-sectional view of a specific example of a gasket groove (a in the figure) and a gasket (b) in the seal structure of the present invention. Fig. 2 shows the gasket of Fig. 1 installed in the gasket groove,
It is sectional drawing of the state which fastened the division sleeve. FIG. 3 is a sectional view showing a state in which a gasket having another shape is mounted in the gasket groove of FIG. 1 and the split sleeve is fastened. FIG. 4 is an explanatory view of an embodiment of the seal structure of the present invention. FIG. 5 is an explanatory view of an example of a conventional sleeve seal structure,
6A is a cross-sectional view of the gasket groove, FIG. 4B is a cross-sectional view of the gasket, and FIG. FIG. 6 is a partially cutaway vertical sectional view of an example of a cable junction box. 3a, 3b …… Split sleeve, 31a, 31b …… Gasket groove,
33 …… Sleeve fastening buckle, 10 …… Gasket, 11
a, 11b ... Upper and lower protrusions, 12a, 12b ... Side protrusions, 13 ...
… Center waist.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Creator Yoshito Hinohara 1-6, Uchisaiwaicho, Chiyoda-ku, Tokyo Inside Nihon Telegraph and Telephone Corporation (72) Kenji Kosugi 1-1-6, Uchisaiwaicho, Chiyoda-ku, Tokyo No. Nihon Telegraph and Telephone Corp. (72) Inventor Hiroshi Takahashi 1-1-6 Uchisaiwai-cho, Chiyoda-ku, Tokyo Nihon Telegraph and Telephone Corp. (72) Nobuo Ide Komaki-shi, Aichi Kitayama Yamairika Nitta Address 1300, within Japan Telecommunication Electronics Co., Ltd. (56) References JP-A-51-149588 (JP, A)

Claims (1)

[Scope of utility model registration request] 1. A vertically symmetric gasket groove having a vertically long hexagonal shape when the split sleeve having a trapezoidal cross section is fastened to the split surface of the split sleeve divided into a plurality of pieces in the circumferential direction,
A vertically symmetrical gasket having protrusions on the upper and lower sides and on both sides is mounted in the gasket groove, and when the sleeve is fastened, a plurality of contacts are symmetrically generated on the inner wall of the groove to keep airtightness. A sleeve seal structure.