JP7075082B2 - Concrete products for cable installation and branching - Google Patents

Description

The present invention relates to, for example, a concrete product for cable installation / branching in which cables such as communication lines and electric wires are wired, accommodated, installed, connected, and branched in an internal space.

In recent years, cables (electric wires) such as power lines for power transmission and distribution and communication lines for telephone and optical communication have been installed on the ground in terms of workability, landscape, and disaster prevention. Underground burial is being promoted instead of being supported by utility poles, and the number of areas where it is being implemented is increasing. Cables of communication lines and electric wires laid underground are drawn into concrete work boxes such as manholes, hand holes, and finger holes to be connected to other cables or branched. At this time, depending on the direction in which the cables are pulled in, a through hole for communicating the cables is formed in the side wall of the work box, and a flexible pipeline or a bell mouth is arranged in the through hole to work from the outside. Work is done to pass cables inside the box. Conventionally, as a method of forming a hole for connecting cables on the side wall of a work box, a knockout portion is formed by thinning the position where cables on the side wall should be communicated in advance, and this thin wall is formed at the construction site. A method of forming a hole by hitting a knockout portion or the like is known. However, in the conventional method of forming a thin-walled knockout portion, the knockout portion cannot be formed into an extremely thin-walled portion in consideration of the infiltration of water due to earth pressure or water pressure from the outside, and as a result, the knockout portion cannot be formed into an extremely thin-walled portion. The work of forming a hole at the knockout part at the work site requires chipping work using a pick or chisel, which requires extremely large labor, and even a skilled person can smoothly form the edge of the hole. There was a problem that it could not be done and it took a long time to work.

On the other hand, in Patent Document 1, the applicant proposes a method for forming a knockout portion of a work box, which can easily form a knockout hole of the work box in a short time. In the method of forming the work box knockout portion of Patent Document 1, a punched concrete member previously formed in a truncated cone shape is supported by a mold at a position to be punched as a knockout hole for cable passage, and the mold is formed in that state. It is a method of filling the frame with concrete, embedding the punched solid member and solidifying it to form a knockout part. A through hole was formed by hitting it toward it and punching it out.

Japanese Unexamined Patent Publication No. 2004-360401

However, in the work box of Patent Document 1, the truncated cone-shaped punched solid member previously formed as a separate member and the concrete forming the side wall of the work box are integrally fixed, but the punched solid member. Although it is easy to punch out with a small striking force by a hammer or the like, there is a risk that the punching solid member will come off even with an extremely weak force. For example, when transporting a work box, or during installation, connection, or branching of cables inside the box, the punched solid member may suddenly come off the side wall, causing the cables to pass through. As a result of the formation of the through hole in the side wall that is not provided, it is necessary to backfill the unnecessary through hole, which may cause a problem that unnecessary labor, material, cost, and time are required. Further, since the contour portion of the punched solid member on the side wall of the work box becomes a concrete joint, there is a possibility that water may infiltrate into the box due to external earth pressure or water pressure.

The present invention has been made in view of the above-mentioned conventional problems, and one of the purposes thereof is to easily form a through hole in a side wall for passing a cable as needed in a short time with low labor and to form a cable. It is an object of the present invention to provide a concrete product for cable installation / branching, which can surely maintain a closed state without unexpectedly forming a hole in a side wall that does not communicate with each other and can prevent water from entering from the outside to the inside.

In order to solve the above problems, the present invention comprises a concrete housing 18 having a bottom wall 12 and a side wall 14 erected from the bottom wall 12 and having an internal space 16 for accommodating or branching a cable L. , A spare hole 20 provided on the side wall 14 which is normally closed to form a part of the side wall 14 and is opened as needed, and an outer surface of the side wall 14 from the inside of the concrete housing 18 fitted in the spare hole 20. A coma member 22 having a tapered side surface (34, 36, 39) and always closing the spare hole 20 to form a part of the side wall 14, and a coma member. It is composed of a concrete product 10 for cable installation / branching, which includes a release agent coating portion 24 provided on the tapered side surface of the 22 and a waterproof material coating portion 26.

Further, the coma member 22 has a first tapered portion 28 having a tapered side surface 34 that expands from the inside of the concrete housing 18 toward the outer surface of the side wall, and the cross section gradually increases toward the outer surface side of the side wall 14, and concrete. A second tapered portion 30 having a tapered side surface 36 that expands from an intermediate position of the thickness of the side wall 14 of the housing 18 toward the outer surface of the side wall 14, and a cross section gradually increasing toward the outer surface of the side wall 14, and a first tapered portion. It may include a stepped portion 32 interposed in the joint portion between the 28 and the second tapered portion 30 to form a stepped portion between the first tapered portion 28 and the second tapered portion 30.

Further, the release agent coating portion 24 provided on the tapered side surface of the coma member 22 and the water blocking material coating portion 26 may be coated on the tapered side surface in a circumferential shape.

Further, the waterproof material 22 is coated only on the stepped wall portion 38 of the stepped portion 32 and its vicinity in a circumferential shape, and stops the inside and outside of the concrete housing 18 of the coma member 22 portion forming a part of the side wall 14. It may be watered.

Further, the concrete housing 18 in which the coma member 22 is fitted into the spare hole 20 of the side wall 14 is a pre-manufactured coma member 22 of a secondary concrete product, and the spare hole of the side wall 14 of the concrete housing 18 is provided. A top member 22 supported and arranged by a formwork (102) at a position corresponding to a mounting position of 20 is included, and concrete is cast and solidified in the formwork (102) to form a side wall 14 of a concrete housing 18. The coma member 22 may be integrated.

According to the concrete product for cable installation / branching of the present invention, a concrete housing having a bottom wall and a side wall erected from the bottom wall and having an internal space for accommodating or branching a cable, and a side wall. A spare hole that is provided and is always closed to form a part of the side wall and is opened as needed, and a trapezoidal cross section that fits into the spare hole and expands from the inside of the concrete housing to the outer surface of the side wall. A coma member which is a coma member and has a tapered side surface and always closes a spare hole to form a part of a side wall, a release agent coating portion provided on the tapered side surface of the coma member, and a water blocking material coating portion. In the side wall that does not allow the cable to pass through, the spare hole will not be opened unexpectedly by a weak force such as vibration during work or transportation, and the closed state can be reliably maintained, and the closed state can be reliably maintained from the outside to the inside. The ingress of water can be reliably prevented. Furthermore, when opening a spare hole in the side wall as needed, such as when passing a cable, the frame member is easily detached in a short time and with low labor by hitting with a hammer, for example, and the spare hole is opened. Can be made to.

Further, the coma member has a first tapered portion having a tapered side surface that expands from the inside of the concrete housing toward the outer surface of the side wall, and the cross section gradually increases toward the outer surface side of the side wall, and a side wall of the concrete housing. A second tapered portion having a tapered side surface that expands from the intermediate position of the thickness toward the outer surface of the side wall and gradually increasing in cross section toward the outer surface of the side wall, and a joint portion between the first tapered portion and the second tapered portion. By including a stepped portion that is provided and forms a stepped portion between the first tapered portion and the second tapered portion, an enlarged stepped portion is provided in the middle of the coma member. Therefore, for example, a water blocking material is provided at the stepped portion. When the coating portion is provided, even in a structure in which the top member and the side wall are adhered to each other via the waterproof material coating portion, the top member can be smoothly detached and a spare hole can be opened, and the top member can be closed at all times. It is possible to simultaneously realize the function of holding and stopping water and the workability of opening the preliminary hole when necessary.

Further, since the release agent coating portion provided on the tapered side surface of the coma member and the water blocking material coating portion are configured to be coated on the tapered side surface in a circumferential shape, the release agent coating portion is provided in a circumferential shape. As a result, the operation of detaching the coma member from the side wall can be smoothly performed, and at the same time, in particular, since the water blocking material coating portion is provided in a circumferential shape, water can be reliably stopped at the coma member portion of the side wall.

In addition, the waterproof material shall be coated in a circumferential shape only on the stepped wall portion of the stepped portion and its vicinity, and shall be configured to stop water inside and outside the concrete housing of the coma member portion forming a part of the side wall. Thereby, it is possible to concretely realize the structure of the water blocking material coating portion which can maintain the water blocking function and at the same time can easily and smoothly separate the coma member from the side wall to open the preliminary hole.

Further, the concrete housing in which the coma member is fitted into the spare hole of the side wall is a coma member of a concrete secondary product manufactured in advance, and the position corresponding to the mounting position of the spare hole of the side wall of the concrete housing. The tapered side surface is formed by including the coma member that is supported and arranged by the formwork, and by placing and solidifying concrete in the formwork and integrating the coma member into the side wall of the concrete housing. Even if the coma member has a shape and includes a coma member having a release agent coating portion and a water blocking material coating portion on the tapered side surface of the coma member, the coma member can be attached to the side wall of the concrete housing. It is possible to easily manufacture integrated concrete products for cable installation and branching.

It is sectional drawing and the enlarged explanatory drawing of the main part of the concrete product for cable installation and branching which concerns on 1st Embodiment of this invention. It is an overall perspective view of the concrete product for cable installation and branching of FIG. (A) is a perspective view seen from the outer end face side of the concrete product for cable installation / branching in FIG. 1, and (b) is a perspective view seen from the inner end face side of the same top member. It is a side view of the top member of the concrete product for cable installation / branching of FIG. It is an operation explanatory view at the time of opening the spare hole of the concrete product for cable installation and branching of FIG. It is explanatory drawing of an example of the manufacturing method of the concrete product for cable installation and branching of FIG. (A) is an explanatory diagram of an example when connecting a cable with the concrete product for cable installation / branching of FIG. 1, and (b) is an explanatory diagram of another example. It is explanatory drawing of another embodiment of the piece member of the concrete product for cable installation / branching of FIG. It is a perspective view of the concrete product for cable installation and branching which concerns on 2nd Embodiment of this invention. (A) is a perspective view seen from the outer end face side of the concrete product for cable installation / branching in FIG. 9, and (b) is a perspective view seen from the inner end face side of the same top member.

Hereinafter, embodiments of the concrete product for cable installation / branching of the present invention will be described with reference to the accompanying drawings. The concrete product for cable installation / branching according to the present invention is made of concrete such as a work box such as a manhole or a handhole, or a U-shaped groove, and cables and electric wires such as communication lines and power lines are wired inside. , Cables for accommodating, installing, connecting and branching, and secondary concrete products for installing electric wires. 1 to 7 show a first embodiment of the concrete product for cable installation / branching of the present invention. As shown in FIG. 1, the cable installation / branching concrete product 10 according to the present embodiment is a cable installation / branching concrete product having a space for accommodating and installing or branching cables (electric wires) inside, and has a bottom. A concrete housing 18 having a wall 12, a side wall 14 and an internal space 16, a spare hole 20 provided in the side wall 14 of the concrete housing 18, and a spare hole 20 are fitted and the spare hole 20 is always closed. A top member 22 forming a part of the side wall 14 and a release agent coating portion 24 and a water blocking material coating portion 26 provided on the side surface of the top member 22 are provided.

As shown in FIGS. 1 and 2, in the present embodiment, the concrete housing 18 will be described with an example of a work box 19 buried in the ground such as a manhole, a hand hole, and a finger hole. The concrete housing 18 has, for example, a substantially rectangular bottom wall 12 and four side walls 14 erected from four substantially rectangular sides which are the outer contour shape of the bottom wall 12, and is substantially three-dimensional. It is integrally molded with concrete in a rectangular shape. Inside the concrete housing 18 surrounded by the bottom wall 12 and the four side walls 14, an internal space 16 is formed in which cables such as communication lines and power lines are accommodated, installed, connected, branched, etc. for wiring. ing. The internal space 16 of the concrete housing 18 is open above, but is closed by a lid (not shown) that can be opened and closed like a conventional work box. In the present embodiment, the spare hole 20 is formed in the portion where the spare hole 20 is formed in each of the four side walls 14 of the concrete housing 18, and the coma member 22 is embedded.

The spare hole 20 is provided in the side wall 14 of the concrete housing 18, and is always closed by the coma member 22 to form the side wall 20, which is opened as needed and penetrates the side wall 14 in the thickness direction to form an internal space. It is a through hole for cable communication in which 16 and the external space 17 are communicated with each other. As shown in FIG. 5, the spare hole 20 is formed in a stepped hole shape including a tapered portion corresponding to the external shape having the tapered side surface of the coma member 22 described later. The spare hole 20 becomes a through hole through which cables and the like are passed when the coma member 22 that fits into the spare hole 20 and is closed is opened in the side wall 14 after being detached.

As shown in FIGS. 1, 3, and 4, the coma member 22 fits into the spare hole 20 of the side wall 14 of the concrete housing 18 and always closes the spare hole 20 to one of the side walls 14. It is a member that forms a part. The coma member 22 is formed by expanding from the inside of the concrete housing 18 toward the outer surface of the side wall 14 in a trapezoidal cross-section, and has a tapered side surface. The top member 22 is separated from the side wall 14 as needed to open a spare hole 20 for passing cables. In the present embodiment, the coma member 22 is made of, for example, a solid member previously formed of concrete or the like into a predetermined three-dimensional shape, and both end faces (33, 35) are formed on the inner and outer surfaces of the side wall 14 of the concrete housing 18. It is integrally formed with the side wall 14 with concrete so as to be embedded in the side wall 14 in an exposed state. More specifically, the coma member 22 has a first tapered portion 28 and a second tapered portion 28 having different cross sections in the side wall 14 of the concrete housing 18 in order from the internal space side toward the outer surface side of the side wall in the thickness direction of the side wall. The tapered portion 30 is integrally joined to each other, and a stepped portion 32 is interposed at the joint portion between the first tapered portion 28 and the second tapered portion 32.

The first tapered portion 28 of the coma member 22 is set to have a length from the inner end surface 33 on the internal space 16 side of the concrete housing 18 to the thickness intermediate position of the side wall 14, and is set from the internal space side 16 side to the side wall 14. It has a first tapered side surface 36 that expands toward the outer surface side (14G), and is formed so that the cross section gradually increases toward the outer surface side (14G) of the side wall 14. The first tapered portion 28 is formed, for example, in a substantially truncated cone shape having a cross-sectional trapezoidal shape, and the central axis is tilted sideways so that the bottom surface having a small diameter is the inner end surface 33. The second tapered side surface 38 is an outer surface side end portion on the large diameter side of the first tapered portion 28, that is, a second tapered side surface 38 that expands from a thickness intermediate position of the side wall 14 of the concrete housing 18 toward the outer surface of the side wall 14. It is formed so that the cross section gradually increases toward the outer surface of the side wall 14. The second tapered portion 30 is formed, for example, into a truncated cone shape having a cross-sectional trapezoidal shape in which the central axis is aligned with the central axis of the first tapered portion 28 and is tilted sideways. It is integrally joined to the large diameter side, and the bottom surface on the large diameter side is the outer end surface 35. The total thickness width of the integrally joined first tapered portion 28 and the second tapered portion 30 is set to be the same as the thickness width of the side surface 14 of the concrete housing 18, and the inner end surface of the coma member 22 is set. 33 is embedded in the side wall so as to be substantially flush with the inner surface 14N of the side wall 14, and the outer end surface 35 is embedded in the side wall so as to be substantially flush with the outer surface 14E of the side wall 14. Around the joint between the first tapered portion 28 and the second tapered portion 30, the small diameter side of the second tapered portion 30 is formed so that the cross-sectional shape is stepped larger than that of the large diameter side of the first tapered portion 28. A stepped wall portion 38 is formed between the first tapered portion 28 and the second tapered portion 30, and the stepped portion 32 is formed. The stepped wall portion 38 of the stepped portion 32 is formed continuously in a circumferential shape at the joint portion between the first tapered portion 28 and the second tapered portion 30 of the coma member 22. For example, the thickness width along the thickness direction of the side wall 14 of the first tapered portion 28 is set to be larger than the thickness width of the second tapered portion, and the step portion 32 is located at a position substantially at the center of the thickness of the side wall 14. Is also set closer to the outer surface side of the side wall. The step portion 32 forms a step wall portion 38 so as to project in the radial direction from the large diameter side end portion of the first tapered portion 28. The stepped wall portion 38 is recessed toward the second tapered portion 30 side in an arc shape in a cross section, for example. By recessing the step wall portion 38 in an arc shape, for example, a water blocking function at the top member portion, an adhesive function integrated with the side wall, and an easy detachment when the top member is detached as needed. The balance is good. The shape of the step wall portion 38 of the step portion 32 may be an arbitrary shape.

As described above, the coma member 22 is formed of a frustum having a tapered side surface having a trapezoidal cross section, whereby when the concrete product 10 is installed in the ground or the like, the soil is directed from the outside to the inside of the side wall 14. Even if pressure, water pressure, or the like is applied, the coma member 22 can be maintained in the closed state without detaching inward. Further, as shown in FIG. 5, when the coma member 22 is separated from the side wall 14 of the concrete housing 18 and a spare hole 24 for passing cables is opened in the side wall 14, if necessary. A spare hole 24 can be opened in the side wall by simply hitting the box from the inside to the outside with a hammer or the like to easily and quickly disengage the box. As shown in FIG. 1, the coma member 22 is provided with a connecting hole 40 from the center of the outer end surface 35 arranged on the outer surface side of the side wall 14 toward the inside. The connecting hole 40 does not penetrate to the inner end surface 33 side, and is a hole for supporting the outer formwork for forming a concrete product via the pin member 42 as described later.

As shown in FIGS. 1, 3, and 4, a release agent application portion 24 is provided on the first tapered side surface 34 and the second tapered side surface 36 of the coma member 22. The release agent application portion 24 is provided on substantially the entire surface of the first tapered side surface 34 and the second tapered side surface 36. The release agent application unit 24 is provided, for example, by applying a conventionally known release agent for concrete to the first and second tapered side surfaces of the top member 22 by any method such as brush coating, spraying, or grooving. As a result, the bonding force between the coma member 22 and the side wall 14 of the concrete housing 18 becomes relatively weak, and the coma member 22 is detached from the side wall 14 as needed, so that the spare hole 20 is smooth, short-time, and clean. Can be opened. The release agent application portion 24 may be applied not only to the entire surface of the tapered side surface of the coma member 22 but also to a part of the tapered side surface in a circumferential shape. Further, a water blocking material coating portion 26 is provided on a part of the tapered side surface 34 of the top member 22. The water blocking material coating portion 26 is made of, for example, a water blocking material having a concrete adhesive function such as silicon resin, which is well known in the past, and is provided in a circumferential shape only on a part of the side wall of the tapered side surface of the top member 22 in the thickness direction. .. In the present embodiment, the waterproof material coating portion 26 is, for example, coated only on the stepped wall portion 38 of the stepped portion 32 and its vicinity in a circumferential shape. The shaded portions in FIGS. 3 and 4 show the waterproof material coating portion 26. The water blocking material coating portion 26 includes a concave stepped wall portion 38 from the vicinity of the stepped portion 32 side of the first tapered side surface 34 of the first tapered portion 28, and is a second taper serving as a protruding end portion of the stepped wall portion 38. The portion up to the small diameter side end portion of the portion 30 is provided in a ring shape continuously in the circumferential direction in a substantially triangular cross section. The water blocking material coating portion 26 is provided on a portion on the rear side of the step portion 32 with respect to the detachment direction of the coma member 22 (the direction from the internal space 16 side of the concrete housing toward the outer surface side of the side wall). There is. The water-stopping coating portion 44 is a water-stopping portion 22 that forms a part of the side wall 14 to reliably stop water inside and outside the concrete housing 18 and to maintain a certain degree of bonding force between the top member 22 and the side wall 14. It also has an adhesive function. By providing the release agent coating portion 24 and the waterproof material coating portion 26 on the tapered side surface of the top member 22, the top member 22 can be easily separated from the side wall 14 only by a considerably weak force such as vibration during transportation. It is possible to keep the closed state without doing. On the other hand, when it is necessary to open the spare hole 20 in the side wall 14 of the concrete housing 18, the coma member 22 is hit with a hammer or the like from the internal space side of the side wall 14 toward the outside to some extent. Since the bonding of the frame members on the side wall is a part, the frame member 22 can be easily separated from the side wall 14 to open the preliminary hole 20. That is, by providing the release agent coating portion 24 and the waterproof material coating portion 26 on the side surface of the top member 22, the side wall 14 that does not open the preliminary hole 20 is maintained in a closed state by the top member 22 and the water stoppage is ensured. At the same time, when the spare hole 20 is opened as needed, the coma member 22 can be easily detached from the side wall 14, so that the side wall can be kept in a closed state at all times and the spare hole 20 can be opened when necessary. It is realized at the same time. When the water blocking material coating portion 42 is provided on the entire tapered side surface, for example, it becomes difficult to separate the top member 22 by hitting with a hammer or the like, and the spare hole 20 cannot be smoothly opened. Therefore, as described above, if a part of the tapered side surface of the coma member 22 is applied in a circumferential shape only on the stepped wall portion of the stepped portion 32 and its vicinity thereof, it is necessary to maintain a closed state at all times and to stop water. Smooth workability of opening the preliminary hole at the time can be suitably realized.

As shown in FIG. 6, when molding the concrete product 10 for cable installation / branching, for example, the coma member 22 is formed into a formwork in advance to form a concrete secondary product, and the concrete housing 18 is formed. It is embedded and molded at the same time as molding. An example of a manufacturing method of the concrete product 10 for cable installation / branching will be described. First, the coma member 22 is formworked with concrete, cured and solidified. Then, the release agent coating portion 24 is provided on the first tapered side surface 34 and the second tapered side surface 36 of the coma member 22, and the waterproof material coating portion 26 is formed in a circumferential shape only in the vicinity of the step portion 32. As shown in FIG. 6A, for example, a box-shaped inner formwork 104 is assembled on the bottom plate 100 so that the bottom wall side of the concrete housing 18 faces upward, and a box-shaped inner formwork 104 is designated around the inner formwork 102. Assemble the outer formwork 102 at intervals. At that time, the coma member 22 is supported by the outer formwork 102 via the pin member 106 in accordance with the position corresponding to the opening position of the predetermined spare hole 20 of the side wall 14. In this state, the inner end surface 33 of the top member 22 is arranged in a state of being substantially in contact with the inner formwork 104. As shown in FIG. 6B, ready-mixed concrete is poured from above into the formwork 100 to be cured and solidified. After that, as shown in FIG. 6C, when the pin member 106 is removed to release the support state of the piece member 22 with respect to the formwork 106 and the formwork is removed, the piece member 22 is placed in the spare hole 20 of the side wall 14. The concrete product 10 for cable installation / branching, in which the coma member is embedded in the side wall by fitting, is completed.

Next, the operation of the concrete product 10 for cable installation / branching according to the present embodiment will be described. The concrete product 10 for cable installation / branching is preliminarily formed into a formwork at a factory or the like by the above method. The concrete product 10 for cable installation / branching is placed on a truck or the like and transported to, for example, an underground wiring site, where the cables are installed in a predetermined position or the cables are pulled into the internal space of the concrete housing. Go and be constructed. At this time, since the water blocking material coating portion 26 is provided on the tapered side surface of the top member 22 in a circumferential shape, the adhesive force thereof makes it easy to use a weak force generated on the top member or the like during vibration during transportation or cable pulling work. The coma member 22 can maintain the closed state without detaching from the side wall 14. For example, when it is necessary to install the concrete product 10 for cable installation / branching at the site and open a spare hole 20 for drawing cables into the side wall 14 of the concrete housing 18, as shown in FIG. In addition, the side wall 14 by the waterproof material coating portion 26 is formed by hitting the top member 22 with a hammer or the like from the internal space 16 side of the side wall 14 toward the outside to some extent (or applying a pull-out force from the outside). The top member 22 is separated from the side wall 14 against the adhesive force between the top member 22 and the top member 22, and a spare hole 20 is formed. The water blocking material 26R forming the water blocking material coating portion 26 when the top member 22 is detached may be attached to the inner wall surface of the preliminary hole 20. Further, the waterproof material coating portion may be separated together with the coma member 22. In this way, it is possible to smoothly form the spare hole 20 penetrating the side wall through which the cables are passed, easily, labor-savingly, and in a short time. On the other hand, with respect to the side wall 14 that does not form a through hole, it is possible to realize a side wall structure in which the coma member 22 can be reliably maintained in a closed state without being abruptly detached and water can be stopped from the outside to the inside. As shown in FIG. 7A, a protective tube 42 for protecting cables such as a bellows tube and a corrugated tube is inserted into the spare hole 20 through the side wall 14 having the spare hole 20 opened, and inside the protective tube 42. The bell mouth 44 is engaged, and the gap between the inside of the spare hole 20 and the protective tube 42 is filled with mortar 46 or the like. Even if the water blocking material of the water blocking material coating portion of the top member 22 adheres to the preliminary hole 20 after the top member is detached, it may be buried as it is. A cable L such as a communication line or a power line is passed through the protection tube 42 and is drawn into the internal space 16 of the concrete housing 18, and wiring work such as accommodation, installation, connection, and branching is performed. As shown in FIG. 7 (b), in the opened spare hole 20, for example, a bellmouth-shaped branch pipe portion 45 and the branch pipe portion 45 are integrated and the outer shape fits into the spare hole 20. A branch pipe block 49 provided with a fitting block portion 47 provided in a substantially truncated cone shape without a step is attached, and a cable protection pipe 42 is attached to an outer 17-side protruding end of the branch pipe portion 45. You may try to connect. The branch pipe block 49 is manufactured in advance by molding the fitting block portion from concrete, resin concrete, or the like in a factory or the like and integrating it with the branch pipe portion. A branch path can be formed only by mounting the spare hole 20 in the opened space. After fitting the fitting block portion 47 formed by the step of the preliminary hole 20, the annular gap portion on the outer side of the side wall 14 is filled with an adhesive such as epoxy resin 50 or a water blocking agent to branch. The pipe block 49 may be fixed or water may be stopped. Also in the case of FIG. 7B, the cable L such as a communication line or a power line is pulled into the internal space 16 of the concrete housing 18, and wiring work such as accommodation, installation, connection, and branching is performed. After the wiring work is completed, the outside of the concrete housing 18 is filled with soil, and the upper part is closed with a lid. Since the coma member 22 that does not open the spare hole 20 is formed in a tapered shape in which the tapered side surface gradually increases from the inside to the outside, the coma embedded in the side wall 14 even when earth pressure or water pressure from the outside is applied. The closed state can be reliably maintained without the member 22 coming off.

The coma member 22 is not limited to the structure of the above-described embodiment. For example, the coma member 22 may be formed in a tapered shape whose cross section gradually increases from the inside to the outside of the side wall 14 of the concrete housing 18, for example, a pyramid-shaped, polygonal frustum-shaped, or elliptical frustum. It may be formed in a three-dimensional shape having a cross-sectional trapezoidal shape having any other tapered side surface such as a trapezoidal shape. Further, as shown in FIG. 8A, for example, the water blocking material coating portion 26 of the coma member 22 is provided so as to straddle the first tapered side surface and the second tapered side surface 36 including the step wall portion 38 of the step portion 32. It may have been. Further, as shown in FIGS. 8 (b) to 8 (f), the cross-sectional shape of the step wall portion 38 of the step portion 32 of the coma member 22 is, for example, a planar shape (FIG.) that is linear in a direction perpendicular to the central axis. 8 (b)), an inclined flat surface (FIG. 8 (c)) that is a straight line inclined in cross section, a shape that is convex toward the internal space 16 side in a circular arc shape (FIG. 8 (d)), and a cross section. A triangular shape that is convex toward the inside of the side wall (FIG. 8 (e)), a shape that is concave in a cross-sectional arc shape toward the second tapered portion 30 side (FIG. 8 (f)), and the like. It may be provided in any shape. The shape of the stepped wall portion may be set according to the adhesive force of the waterproof material coating portion 26 to the coma member 22 and the water blocking property, or the convenience of detaching the coma member from the side wall. good.

Next, a second embodiment of the concrete product for cable installation / branching of the present invention will be described with reference to FIGS. 9 and 10. The same members as those in the above embodiment are designated by the same reference numerals, and detailed description thereof will be omitted. Also in this embodiment, the concrete product 10-2 for cable installation / branching always has a concrete housing 18, a spare hole 20 provided in the side wall 14 of the concrete housing 18, and a spare hole 20 as in the above embodiment. Is provided with a coma member 22 that is closed to form a part of the side wall 14 and is detached as needed, and a release agent coating portion 24 and a waterproof material coating portion 26 provided on the tapered side surface of the coma member 22. There is. In the present embodiment, the concrete housing 18 is a U-shaped block having a rectangular bottom wall 12 formed long on one side and a side wall 14 erected from the opposite long sides of the bottom wall 12. It consists of 48. A long internal space 16 is formed on one side between two pairs of side walls 14 facing in the longitudinal direction. The U-shaped block 48 is connected in the longitudinal direction to connect the internal space 16 in the longitudinal direction. The open upper part of the internal space 16 of the concrete housing 18 is closed with a lid (not shown) so as to be openable and closable.

As shown in FIGS. 9 and 10, in the present embodiment, the shape of the spare hole 20 formed in the side wall 14 and the shape of the coma member 22 fitted in the spare hole 20 are along the longitudinal direction of the side wall. It is provided so as to have a long shape. For example, in the vertical cross section orthogonal to the side wall surface, the coma member 22 expands in a trapezoidal shape from the internal space 16 side to the outer surface side, and the cross-sectional shape on the surface intersecting the thickness direction of the side wall 14 is in the longitudinal direction of the side wall. It is provided in the shape of a horizontally long horizontal round frustum along the line. Therefore, the coma member 22 has an inner end surface 35 and an outer end surface 37 having a substantially horizontally elongated round shape. Similar to the above embodiment, the coma member 22 has a first tapered portion 28 having a first tapered side surface 34, a second tapered portion 30 having a second tapered side surface 36, a first tapered portion 28, and a second tapered portion 30. Includes a step portion 32 that forms a step between the two. The vertical cross-sectional shape of the top member 22 and the vertical cross-sectional shape of the side wall 14 in which the top member 22 is embedded are substantially the same as those in FIG. 1 of the above embodiment. The release agent application portion 24 is provided on the entire surfaces of the first tapered side surface 34 and the second tapered side surface 36. The water blocking material coating portion 26 is provided in a circumferential shape on a portion near the step portion 32 side of the first tapered side surface 34 and a step wall portion 34 portion of the step portion 32. In the present embodiment, two connecting holes 40 are formed on the outer end surface 37 side of the top member 22 so as to be separated from each other in the horizontally long direction. Also in this embodiment, when the concrete housing 18 is formed by the formwork, the top member 22 of the secondary product manufactured in advance is provided with the peeling coating portion 24 and the waterproof material coating portion 26, and the top member is provided. In a state of being supported by a pin member on the outer formwork 22, concrete is cast in the formwork, and the coma member 22 is embedded in the side wall 14 to be integrally formed. In the present embodiment, the coma member 22 is formed horizontally long. Therefore, when the coma member 22 is punched out from the side wall 14 by a hammer or the like, the side wall 14 is opened with a horizontally long spare hole 20 long in the longitudinal direction. Will be done. By forming the horizontally long spare hole 20, for example, it can be suitably used when branching a cable having a large diameter and being difficult to bend, such as a power line. Also in the present embodiment, as in the above embodiment, even if an extremely weak force is applied to the top member or the like, the top member can be kept closed without suddenly opening the spare hole 20 and the top member 22 can be reliably maintained. In addition to being able to stop water, when it is necessary to pass a cable, the coma member should be relatively easily detached by hitting with a hammer or the like to form a spare hole penetrating the side wall with low labor and in a short time. Can be done.

The concrete product for cable installation / branching of the present invention described above is not limited to the configuration of only the above-described embodiment, and is arbitrarily modified as long as it does not deviate from the essence of the present invention described in the claims. May be done.

The concrete product for cable installation / branching of the present invention contains, for example, work boxes such as manholes, handholes and fingerholes, communication lines such as U-shaped grooves and cable troughs, cables such as power lines, and electric wires. It can be suitably applied to concrete products to be used.

10 Concrete products for cable installation / branching 12 Bottom wall 14 Side wall 16 Internal space 18 Concrete housing 20 Spare hole 22 Top member 24 Release agent application part 26 Water stop material application part 28 1st taper part 30 2nd taper part 32 Step Part 34 1st tapered side surface 36 2nd tapered side surface 38 Stepped wall part

Claims (5)

A concrete housing having a bottom wall and a side wall erected from the bottom wall to form an internal space for accommodating or branching cables.
A spare hole provided on the side wall that is normally closed to form part of the side wall and is opened as needed.
A top member that fits into the spare hole and expands in a trapezoidal shape from the inside of the concrete housing toward the outer surface of the side wall. It has a tapered side surface and always closes the spare hole to form a part of the side wall. Members and
A concrete product for cable installation / branching, which includes a release agent coating portion provided on the tapered side surface of the top member and a waterproof material coating portion. The coma member has a first tapered portion having a tapered side surface that expands from the inside of the concrete housing toward the outer surface of the side wall, and the cross section gradually increases toward the outer surface side of the side wall.
A second tapered portion having a tapered side surface that expands from the intermediate position of the thickness of the side wall of the concrete housing toward the outer surface of the side wall, and the cross section gradually increases toward the outer surface of the side wall.
The cable installation according to claim 1, further comprising a stepped portion interposed between the first tapered portion and the second tapered portion to form a stepped portion between the first tapered portion and the second tapered portion. -Concrete products for branching. The cable installation / branching according to claim 1 or 2, wherein the release agent coating portion provided on the tapered side surface of the coma member and the waterproof material coating portion are coated on the tapered side surface in a circumferential shape, respectively. Concrete products. The claim is characterized in that the waterproof material is coated only on the stepped wall portion of the stepped portion and its vicinity in a circumferential shape to stop water inside and outside the concrete housing of the coma member portion forming a part of the side wall. The concrete product for cable installation / branching according to any one of Items 1 to 3. The concrete housing in which the coma member is fitted into the spare hole on the side wall is
A coma member of a pre-manufactured secondary concrete product, including a coma member supported by a formwork at a position corresponding to a mounting position of a spare hole on a side wall of a concrete housing.
The concrete product for cable installation / branching according to any one of claims 1 to 4, wherein the concrete is cast and solidified in the formwork and the coma member is integrated with the side wall of the concrete housing.

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