JP3022072B2 - Method of stopping water in a cable duct and water stopping structure therefor - 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 and a structure for stopping a cable duct buried underground.

[0002]

2. Description of the Related Art It is known that a cable is accommodated in a duct when the cable is laid. However, the inside of the duct is always inundated, and the flowing water is an important issue in quality control of the cable. That is, water that enters the cable duct flows into the area where the current control device of the cable is provided and drops through the duct, and the interior of the room becomes high in humidity and becomes a humid atmosphere. Corrosion or rusting of the equipment made of metal is caused, and maintenance and management of cables or equipment in the cable duct becomes difficult.

As a water stop method for avoiding such a drawback, a water stop has been conventionally performed by filling a cable duct with clay, quick-setting cement or the like. However, this water stopping method is not generally used because the water stopping material used damages rubber, resin, etc., which are the covering of the conductor.

Further, as a conventional water stopping method, a spacer is cut into an appropriate length in a duct, wound around a cable until the diameter becomes slightly larger than the inside diameter of the duct, and the urethane foam is cut into a duct diameter. There is known a method in which a cable is wound larger, a pushing duct is closed in a duct, and then a foamed resin is injected and foamed.

However, in this method, when a large number of twisted cables are inserted into the duct as described above,
The resin does not completely enter into the twist gap, the cable is not completely covered with the resin, and a gap is formed between the cable and the coating resin, which causes flooding. Also,
It is difficult to work when there is running water in the cable duct.

Further, the cable accommodated in the cable duct is a single wire or a multi-core stranded wire, and is not stable in the duct due to an electric load or other factors, and may move in the longitudinal direction of the cable. Known structures do not allow for this movement.

A disadvantage of such a cable duct is that the inner cross section of the cable duct can be formed into several circular shapes, whereas the cross sectional shape of the cable is diverse, and in particular, multi-core. Cables have various gaps and outlines, and these various types of cables are provided with a cable guide that requires a water-blocking structure, and the guide-through shape of this guide is limited. It is difficult to accommodate the cable ducts uniformly.

[0008]

SUMMARY OF THE INVENTION Based on the above-mentioned known techniques, the object underlying the present invention is to solve the above-mentioned various methods and devices provided by a conventionally known method and apparatus for stopping water in a cable duct. It is an object of the present invention to provide a method and a water stop structure which have no disadvantages.

[0009]

SUMMARY OF THE INVENTION According to the present invention, there is provided, in accordance with the present invention, a lower cylindrical half made of synthetic material having a recess corresponding to the thickness of a cable inserted into the air space of a cable duct. On the other hand, the cable is placed, and on the other hand, upper cylindrical halves each having a concave portion having the same diameter as the concave portion and made of the same material are provided at the arc ends of the two cylindrical halves in male and female correspondence. The concave portion is fitted with the lower cylinder half to form an airspace, and then the needle of the injection device is pierced from the side of the upper cylinder half, and formed at the time of the fitting. The problem is solved by injecting urethane resin into the air space in which the cable is built, and fixing the cable under resin foam in this air space.

[0010] The water stop structure for carrying out the above method is characterized in that the lower half cylinder made of a synthetic material having a concave portion corresponding to the thickness of the cable in the air space of the cable duct; A lower cylinder half made of a synthetic material, provided with a recess having the same diameter as the recess of the lower cylinder half, and a water guide hole into which a water retaining pin is inserted, and these two cylinder halfs are formed. Is that a convex portion and a concave portion formed corresponding to the male and female are fitted to these arc ends to form an air space in which the cable is built.

The present invention will be described in detail with reference to the embodiments illustrated in the accompanying drawings.

[0012]

FIG. 1, FIG. 3, FIG. 5, FIG. 7, FIG.
FIG. 3 is a view showing each step of a water stopping method according to the present invention.

FIGS. 2, 4 and 6 are cross-sectional views of a water stop structure for carrying out this method. First, the lower half cylinder 1 having the following structure shown in FIG. 2 is inserted into the cable duct 5 as shown in FIGS. The lower half cylinder 1 has a side wall on which a concave portion 2 corresponding to the thickness of the cable can be formed in the air space of the cable duct, and a step (not shown) in some cases. It is made of a synthetic material having a deeper concave cut-out portion, and its length may be long enough to properly support the cable 6. The lower half cylinder 1 has a recess 2 by notching as described above, the diameter of which corresponds to the thickness of the cable 6 in each case.

The lower cylinder half and the upper cylinder half described below are constructed completely symmetrically with the lower cylinder half 1 and therefore have a recess 2 which is likewise machined. However, in order to facilitate sliding in the longitudinal direction of the cable,
It is advantageous to apply a water-repellent oil or fat such as silicone or grease. Accordingly, it is possible to follow the behavior of the cable in the swing state of the cable duct.

Further, the lower half cylinder 1 has a water guide hole 7 at its lower center, through which water constantly flowing is drained. Here, as shown in FIG. 3, the cable 6
Is placed. At this time, since the diameter of the concave portion 2 matches the diameter of the cable as described above, the cable is inserted into the cable mounting gap 5 ′ of the concave portion 2 in an optimum state.

Each of the lower cylindrical half 1 and the upper cylindrical half 1 'described below is provided with a concave notch at the end of the circular arc at the end of the circular arc to ensure the fitting for mating with the counterpart. 4 and a convex protrusion 3 are formed in a manner corresponding to male and female.

Here, in order to form the air space 17 into which the resin 8 for fixing the cable is fixed in the water-stop structure according to the present invention, it is made of a synthetic material having the same material as that of the lower cylinder half 1 described above. And an upper cylinder half 1 'having a recess 2 of the same diameter, the details of which are shown in the drawing since this upper cylinder half 1' is formed completely symmetrically with the lower cylinder half 1. Was not present, but as shown in FIGS. 5 and 6,
It is placed on the lower cylindrical half body 1 on which the cable is laid via the arc edge, and the two cylindrical half bodies are combined under pressure (see the working state indicated by reference numeral A in FIG. 10). ). In this case, the upper cylinder half 1 'and the lower cylinder half 1 extend in the longitudinal direction of these cylinder halves at the terminal edges of their arcs, as described above, in a male and female corresponding manner. A concave notch 4 and a convex protrusion 3 are formed, and they are fitted when the two cylindrical halves are united. Therefore, the uniting of both is performed so that the air space 17 can be completely closed. This operation is performed reliably (see FIG. 11, which is a diagram showing a state in which the two cylindrical half bodies 1 and 1 ′ are united in the cable duct 5).

After the combining step has been completed in this way, as shown in FIG. 7, a needle 16 of a resin injector 15 is pierced into the side surface of the upper cylindrical half 1 ', and the resin 8, especially Urethane foam is injected into an air space 17 formed in the center of the two cylinder halves 1, 1 '. As a result, the resin penetrates into the surroundings so as to surround the cable 5.

At this point, the resin has not foamed yet,
Therefore, the complete sealing of the cable duct 5 is not performed.

The water blocking structure injected as described above can be easily crushed with a tool or the like when the cable 5 is disassembled or replaced. Further, the water blocking structure injected as described above does not flow due to the constantly flowing water pressure until the water blocking structure is integrally connected to the cable. Normally, water flows through the water introduction hole 7 (see FIG. 7), but when the water introduction hole 7 has a shortage of capacity compared to the amount of flowing water, the water is forcibly sucked by an appropriate suction means.

Here, the resin 8 is filled in the air space 17 with the passage of time.
5 and FIG. 7, and after a while, the entire space of the air space 17 is filled as shown in FIG. 8.
1 ′ is pressed against the inner peripheral surface of the cable duct 5. At the same time, the cable lead-out portions 21 and 2 of the two cylindrical halves 1, 1 '
2 is also sealed.

After all the above steps are completed, the water stop pin 20
Is inserted into the introduction hole 7 (see FIG. 9).

[0023]

According to the above-mentioned water stop method and water stop structure, the water stop is more reliably performed as compared with the conventional known method and water stop structure having the above-mentioned disadvantages. In particular, when a large number of cables are laid in a twisted manner, intrusion of the resin into the twisting gap is reliably performed. Further, in such a cable duct, the cable must be disassembled and replaced at a certain time, and for this purpose, the water stop structure is easily crushed with a tool or the like and can be removed.

Further, the water stopping method and the water stopping structure according to the present invention prevent the electric equipment in the cable duct from being corroded or rusted, thereby facilitating maintenance and management. The cables laid in this cable duct are also protected from breakage, breakage and wetting.

[Brief description of the drawings]

FIG. 1 is a view showing a water stoppage construction process according to the present invention.

FIG. 2 is a cross-sectional view of the lower cylinder half-split body, but showing a state in which the cable is not placed in a concave portion.

FIG. 3 is a view showing a water stoppage construction process according to the present invention.

4 is a cross-sectional view of the lower half-cylindrical body shown by a cutting line A-C in FIG.

FIG. 5 is a view showing a water stop construction process according to the present invention.

FIG. 6 is a view showing a state in which the two cylinder half bodies are united and a resin is injected.

FIG. 7 is a view showing a water stop construction process according to the present invention,
It is a figure which shows especially a resin injection process.

FIG. 8 is a view showing a water stop construction process according to the present invention,
It is a figure showing the state where the injected resin was completely foamed.

FIG. 9 is a view showing a state in which a water blocking pin has been inserted and water has been filled in the cable duct.

FIG. 10 is a view showing a water stop construction process according to the present invention, in which a lower cylinder half is inserted into a cable duct, but the resin is not yet filled in the air space of both cylinder half. It is the figure shown in the state.

FIG. 11 is a view showing a state in which the two cylinder halves are united, but a state in which the resin is not yet filled in the air space of the two cylinder halves.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Lower cylinder half-split 1 'Upper cylinder half-split 2 Concave part 3 Convex part 4 Concave part 5 Cable duct 5' Cable mounting space 6 Cable 7 Water guide hole 8 Resin 9 Injection hole 15 Resin injector 16 Injection needle 17 Empty region 20 Water Stop pins 21, 22 Clearance between cable and cable duct cylinder half

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-3-212105 (JP, A) JP-A-3-230715 (JP, A) JP-A-4-21307 (JP, A) 7617 (JP, U) JP 7-27248 (JP, U) JP 52-2307 (JP, Y2) (58) Fields investigated (Int. Cl. ⁷ , DB name) H02G 9/00-9 / 12 H02G 3/22-3/28 H02G 15/00-15/196

Claims (2)

(57) [Claims] 1. A method for flooding a cable duct buried underground, comprising a recess corresponding to the thickness of a cable (6) in a cable mounting space (5 ') of the cable duct (5). A lower half-body (1) made of synthetic material with (2) is inserted and a cable is placed in this recess, while having a recess (2) having the same diameter as said recess (2) and having the same An upper cylindrical half (1 ') made of a material is provided with a convex part (3) and a concave part (4) formed at the arc ends of the two cylindrical half parts (1, 1') in a male and female correspondence. Is fitted to the lower half cylinder (1) to form an airspace (1).
7) is formed, and then the needle (16) of the injection device (15) is pierced from the side surface of the upper cylindrical half (1 '), and the cable formed at the time of the fitting is incorporated. A method for watertightening a cable duct, characterized by injecting a urethane resin (8) into an airspace (17) and fixing a cable (6) under resin foam in the airspace. 2. A water stop structure for stopping a cable duct buried underground, wherein the water stop structure is provided with a cable in a cable mounting space (5 ') of a cable duct (5). A lower cylinder half (1) made of a synthetic material having a recess (2) corresponding to the thickness of (6); and having a diameter equal to that of the recess (2) of the lower cylinder half (1 '). A lower cylinder half (1) made of a synthetic material, the lower cylinder half having a recess (2) and a water guide hole (7) into which a water stop pin (20) is inserted. (1,
1 ') is formed by fitting a convex part (3) and a concave part (4) formed at the ends of the circular arc corresponding to the male and female, thereby forming an air space (17) in which the cable (6) is built. A water blocking structure for stopping a cable duct, wherein the water blocking structure is configured to be closed.