JPH0952215A - Core for form for manufacturing concrete block of common-use cable tunnel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a core for a form which enables easy manufacture of a block of a common-use cable tunnel out of concrete. SOLUTION: As a core 1, divided pieces 2 prepared by dividing a round tube in a plurality longitudinally are disposed in the shape of a cylinder with gaps provided between, and a support member 11 screwed on a thread 6 of a central shaft 4 and the divided pieces 2 are pin-connected by radial connecting links 13, which are so designed as to be raised and brought down in the longitudinal direction of the tube so as to reduce the outside diameter of the divided pieces 2 by turning the central shaft 4. A flexible cylindrical cover 21 is put on the outer peripheries of the divided pieces 2 so that fitting of the core 1 to a form and removal thereof from the form be facilitated.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a core for a concrete block manufacturing formwork for an electric wire common groove for burying an optical fiber, an electric power cable and the like underground. The present invention is applicable to both straight pipe blocks and curved pipe blocks.

[0002]

2. Description of the Related Art In recent years, in preparation for the advent of the advanced information society, it is necessary to maintain a cable network such as the laying of large-capacity cables, and there is an opportunity to bury power lines and communication cables underground. The Act on Special Measures concerning etc. was enacted. Such an electric wire joint groove (so-called C ・ C ・ Box)
As the electric wire common grooves 81 and 91 as shown in FIG. 18, for example, a structure in which a block having a large number of electric wire insertion through holes of 50 to 200 mmφ is used alone or in combination thereof is being advanced. FIG. 18 shows a cross-sectional view of a road and a partially enlarged view of the arrangement of the electric wire common grooves 81 and 91 buried underground such as the sidewalk 80. Blocks 82 and 92 provided with through holes 83 and 93 for accommodating optical fibers 84 and 94 are used as the electric wire common grooves 81 and 91.

The electric wire common groove has a smaller cross-sectional size than a conventional underground wiring path, and a new cable can be inserted from the branch portion into the electric wire insertion through hole, so that the ground is not dug each time. There is a merit that it is okay. Such blocks are mostly straight lines, but in part
It is necessary to bypass other underground equipment and obstacles, and it becomes curved at curved roads and intersections, and inevitably many curved parts are necessary due to other reasons such as cable connection and branching. is there.

When such a block of the electric wire common groove is manufactured from concrete, it is necessary to facilitate the extraction of the core formwork which forms the electric wire insertion through hole. On the other hand, the inner surface of the hole of the block is required to be a smooth surface without any seams or steps.

[0005]

DISCLOSURE OF THE INVENTION The present invention has developed a mold core for manufacturing a concrete block used as an electric wire common groove for burying such an optical fiber, an electric power cable or the like underground, It is intended to provide this. The core of such a mold needs to have a wire insertion through hole having a smooth and accurate inner surface, and moreover, it needs to be a core that can be easily pulled out after hardening of concrete. Further, it is necessary for the form of the block of the curved portion to have an electric wire insertion through hole having a smooth and accurate radius of curvature and a smooth and accurate inner surface. Such a mold core is not preferable in the case of a conventional core which is conventionally used and is formed by combining a large number of pieces that can be pulled out, because the seams of the pieces remain as joints in the holes. Further, if a step or the like is generated at the joint between the blocks, there is a problem that the optical fiber or the like cannot be smoothly inserted when it is inserted. Furthermore, it is also possible to embed a foamable resin or other destructible or consumable member as a core, and after the concrete is hardened, mechanically destroy it, or dispose of the core by using a member that can be removed by heating or chemicals. In this case, however, it is difficult for the core to maintain sufficient strength and accuracy during concrete molding, removal is not easy, and consumables cost rises.

[0006]

The present invention is characterized by taking the following technical means in order to solve the above problems. That is, the core of the present invention for forming the electric wire common groove concrete block has a feature in the structure of the core. A core of a first invention of the present invention for forming an electric wire insertion through hole of an electric wire common groove concrete block is a plurality of divided pieces obtained by vertically dividing a circular pipe with a gap provided between the divided pieces. A radial coupling link that couples the split piece to the central axis, a tilting device that tilts the split link in the pipe longitudinal direction to reduce the outer diameter of the split piece, and a flexible member that fits over the outer circumference of the split piece. A core for a mold for manufacturing a concrete block for electric wire common grooves, which is characterized in that it is formed of a flexible cylindrical coating.

Further, as a core of the second invention of the present invention for forming an electric wire insertion through hole of an electric wire common groove concrete block, a part of the circumference is cut along the bus bar over the entire length of the cutout pipe. A circular tube that forms a notch and bends inward so that the diameter can be reduced, and an insert piece that fits into the notch and restores the circumference,
There is provided a core for a mold for manufacturing a concrete block for forming an electric wire common groove, which comprises a wedge for pushing an insertion piece into the cutout portion and a flexible cylindrical coating fitted on the outer circumference of a circular pipe.

Both the core of the first invention and the core of the second invention can be applied to both a straight pipe block and a curved pipe block.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION The core for manufacturing a concrete block for forming an electric wire common groove of the present invention is used for producing a concrete block used as an electric wire common groove. Such blocks have traditionally been made of porcelain. In the present invention,
Intended for cement hardener blocks made of concrete or a material similar to concrete.

In any of the cores of the mold of the present invention, the portion contacting the outer surface of the core, that is, the inner surface of the wire insertion through hole is
It is an integral flexible cylinder, and a cylindrical device that can reduce its diameter when demolding is built inside. The core of the first aspect of the present invention will be described with reference to FIGS. 1 to 6 show cores for straight pipe blocks,
7 to 10 show a core for a bent tube block.

First, the examples of FIGS. 1 to 6 will be described.
1 is a partial longitudinal sectional view of an embodiment of a core for a straight pipe, FIG. 2 is a sectional view taken along the line AA, FIG. 3 is a view taken along the line BB, and FIG.
6 is a view showing a state in which the internal device of the core is reduced in diameter, as viewed in the direction of arrow C-C of FIG. 4, and FIG. 6 is a side view of the diameter reduction device. In this embodiment, the core 1 is formed by arranging three divided pieces 2 into which a right circular pipe is divided into three in a vertical split form with a gap therebetween, and arranged in a cylindrical shape. A shaft 4 passes through the center of the core 1. The shaft 4 is provided with a screw 6 and is connected in the longitudinal direction by a coupler 5. A coupling member 11 that is coupled to the split piece 2 is externally fitted on the screw 6. The split piece 2 is joined by a joining link 13 to a bracket 12 attached to a joining member 11 fitted on the screw 6 of the shaft 4. Link 1
The other end of 3 is connected by a pin 15 to a bracket 14 provided inside the divided piece 2. FIG. 2 shows this state. The coupling link 13 is tilted up and down in the longitudinal direction of the core 1 to move the split piece 2 inward in the radial direction. A flexible cylindrical coating 21 is fitted on the outer surface of the cylinder formed by the divided pieces 2.

FIG. 3 shows the structure of the end of the core 1.
The end portions are provided with end plates 9 that abut against the end portions of the adjacent divided pieces so that the end portions of the three divided pieces 2 coincide with each other. A stand 7 for supporting the shaft 4 is provided on one of the three pieces 2. The stand 7 is provided with an oval hole so as not to prevent the divided pieces 2 from moving inward in the radial direction. A positioning piece 8 for positioning the shaft 4 in the longitudinal direction is in contact with the outer surface of the stand 7. The positioning piece 8 also has a function of receiving a reaction force when the divided piece is moved in the radial direction.

FIG. 4 shows the reinforcing plate 3 attached to the divided piece 2. The reinforcing plate 3 is a crescent-shaped plate, and a reinforcing member 3a for further increasing its rigidity is attached. As shown in FIG. 5, the reinforcing plate 3 has a shape that does not interfere with each other when the divided pieces 2 have a reduced diameter. FIG. 5 shows a state in which the split piece 2 has a reduced diameter, and a gap is formed between the outer circumference of the split piece 2 and the flexible cylindrical coating. Therefore, the core 1 can be easily extracted from the hardened concrete of the concrete block.

FIG. 6 is an explanatory view of the diameter reducing operation of the divided piece 2. The shaft rotating device 10 at the end of the shaft 4 shown in FIG.
When the is rotated, the connecting member 1 screwed into the screw of the shaft 4
1 moves to the left in FIG. 1, for example. The pin-linking coupling link 13 coupled to the coupling member 11 falls like 13a shown in FIG. 6, and the split piece 2 moves inward in the radial direction. At this time, the positioning member 8 comes into contact with the stand 7 provided at the end of the divided piece 2, and the positioning member 8
Serves as a reaction force device for moving the divided piece 2. When the shaft 4 is rotated in the opposite direction, the connecting link 13 moves the split piece 2 outward in the radial direction.

The flexible cylinder coating 21 is an integral flexible cylinder having no seams or the like. The material is a synthetic resin such as a pipe made of rubber, vinyl chloride pipe, polyethylene pipe, etc., which is highly flexible, has a smooth surface, does not react with concrete, has good separability from concrete, and is highly durable. Materials are preferred. The mold using the core of the example can be easily adapted to the regular size of the core and the reduced size at the time of demolding by expanding / contracting the core. A concrete block having a smooth inner surface can be easily manufactured without requiring any disassembly.

FIG. 7 is a schematic diagram when the first invention is applied to the core 1 of the curved tube block. Illustration of the flexible cylinder on the outer periphery is omitted. As shown in FIG. 8 along the line D-D in FIG. 7, the curved pipe is divided into a plurality of pieces along the tube axis, and the divided pieces 2 having a gap therebetween are arranged in a cylindrical shape. Axis 4
Is used by connecting multiple shafts with joints according to the curvature of the curved pipe. The coupling member 11 is provided on the shaft 4 as in FIG.
And the connecting member 11 are connected by a connecting link 13. Axis 4
The connecting portion between them is a universal joint 17 as shown in FIG. 9 or a bellows type flexible joint 18 as shown in FIG.
Is used. By operating the shaft rotation device 10, the coupling link 13 is raised and lowered to expand and contract the split piece 2.

Next, the core of the second invention of the present invention will be described. This core can also be applied to either a straight pipe block or a curved pipe block. The core of the second invention is
A circular pipe is used in which a part of the circumference is cut out along the generatrix, a cutout is formed over the entire length of the pipe, and the diameter of the circular pipe can be reduced by bending it inward. The diameter can be reduced when mounting the core on the formwork. Since this core is provided with a flexible cylindrical coating on the outer circumference of the tube, it can be easily inserted into the mold core holding portion. Further, after the concrete is hardened, it can be easily extracted.

Further, this core is provided with an insert piece which is fitted in the cutout portion and restores the circumference, and is provided with a wedge which pushes the insert piece into the cutout portion, so that the circumference is easily obtained from the end portion of the pipe. Can be restored, resulting in a tube with a perfect circular cross section. The flexible cylindrical coating fitted on the outer circumference of this circular pipe may be any material as long as it is a material that does not harm concrete and is flexible and highly durable, such as natural rubber or synthetic rubber. A flexible elastic material and a synthetic resin such as vinyl chloride or polyethylene can be used. Further, a woven fabric, a non-woven fabric or the like, or a composite material in which a coating film is provided on these may be used. Further, it may have an appropriate thickness.

An insert piece that fits in the notch of the core and restores the circumference is provided inside the core and is pushed into the notch by a wedge from the end of the circular pipe. Therefore, it can be easily inserted and removed. A bracket or the like for attaching and detaching the core is provided at the end of the core. Block 1 core
Or, it is possible to provide a plurality.

The block of the present invention can be manufactured by placing concrete in a concrete formwork provided with an extraction core, curing it, and then extracting the core. Next, the core of the second invention of the present invention will be described by way of an example applied to a curved tube block. The curved tube block can be configured in any manner according to the actual situation, but for example, it is appropriate that the radius of curvature of the wire common groove is 2 m or more and the angle of the center of curvature formed by both end surfaces of the curved tube is 9 degrees or less. It is preferable because the curved pipeline can be formed with a reasonable number of blocks.

FIG. 16 shows a longitudinal sectional view of an example of the electric wire common groove concrete curved pipe block 61 to be manufactured using the mold of the present invention, and a front view thereof is shown in FIG. Block 61
Has an electric wire insertion through hole 62, and the through hole 62 and the profiles 64 and 65 have an arc shape sharing the same center 63. Connecting rod insertion through hole 6 for connecting this block
6 is provided. In this example, four wire insertion through holes 62 are arranged, but the number is arbitrary. The curved tube block is manufactured to have a length and size suitable for the shape according to the size of the radius of curvature. Both end faces 69 of the block,
69 is formed at a right angle to the longitudinal axis of the through hole 62. The block 61 is a concrete product that is manufactured by pouring into a mold.

14 and 15 show a mold for manufacturing this block 61. The formwork is a side plate 51 that is tilted sideways around a pin 52 attached to a base body 53 of the bottom plate,
51 and face plates 54 and 54 for connecting both ends of the cores 31 and 31, respectively, are assembled in a box shape. The bottom plate 55 and the top plate 56 forming the profile also serve as a connecting material.

FIG. 11 is a partial cross-sectional side view of a core 31 of a core for a mold for producing a concrete curved tube block for electric wire common embodiment, and FIGS. 12 and 13 are end views thereof. This core 31
Is a curved pipe 32 having a circumferential notch inside the rubber coating 41.
Is built-in. The curved pipe 32 is provided with a weakening portion 36 on the circumference opposite to the cutout portion, and as shown in FIG. 12, the cutout portion is bent around the weakening portion 36 so that the cutout portion is narrowed and reduced in diameter. It is supposed to do. FIG. 13 shows a state in which the insertion piece 33 is pushed into the notch by the wedge 35. The curved tube 32 restores its circular shape, and the rubber tube 41 maintains a perfect circular cross section. Reinforcing plates 34 are attached to both ends of the curved pipe 32, and the wedge 35 applies a reaction force to the reinforcing plates 34 to push the insertion piece into the notch. An ear 37 is attached to the reinforcing plate 34, and the ear 37 is a bracket for attaching and detaching the core to the formwork.

Since the core of the present invention is constructed as described above, it is easy to install and remove from the mold, and the flexible cylindrical coating has extremely smooth concrete without causing steps or joints. Form the inner surface.

[0025]

EFFECT OF THE INVENTION Since the core for the electric wire joint groove concrete block manufacturing formwork of the present invention is constructed as described above,
An electric wire joint groove concrete block having a circular through hole having a smooth inner surface can be easily manufactured. It is also easy to install and easy to remove from concrete, and can be used repeatedly.

[Brief description of drawings]

FIG. 1 is a partial vertical cross-sectional view of a core of an embodiment.

FIG. 2 is a sectional view taken along the line AA of FIG.

FIG. 3 is a view taken in the direction of arrows BB in FIG. 1;

FIG. 4 is a view taken in the direction of arrows CC in FIG. 1;

5 is a view showing a state in which the internal device of the core has a reduced diameter in the CC line view of FIG. 1. FIG.

FIG. 6 is a side view of the diameter reducing device.

FIG. 7 is a schematic view of a core of another embodiment.

8 is a view as viewed in the direction of the arrow DD in FIG. 7;

FIG. 9 is a side view of the universal joint of the shaft.

FIG. 10 is a vertical cross-sectional view of a shaft bellows type flexible joint.

FIG. 11 is a partially cut side view of a core of a core for a bending tube block manufacturing form according to an embodiment.

FIG. 12 is an end view of FIG.

FIG. 13 is an end view of FIG.

FIG. 14 is a front view of the mold of the embodiment.

FIG. 15 is a side view of the mold of the embodiment.

FIG. 16 is a vertical sectional view of a manufactured block.

FIG. 17 is a front view of a manufactured block.

FIG. 18 is an explanatory view showing a cross section of the electric wire common groove.

[Explanation of symbols]

1 Core 2 Split Piece 3 Reinforcing Plate 4 Shaft 5 Coupler 6 Screw 7 Stand 8 Positioning Piece 9 End Plate 10 Shaft Rotating Device 11 Coupling Member 12 Bracket 13 Coupling Link 14 Bracket 15 Pin 16 Pin 17 Universal Joint 18 Flexible Joint 21 Cylindrical coating 31 Core 32 Curved tube 33 Insertion piece 34 Reinforcement plate 35 Wedge 36 Weak portion 37 Ear 41 Cover 51 Side plate 52 Pin 53 Base 54 Face plate 55 Bottom plate 56 Top plate 61 Curved tube 62 hole 63 Curvature center 64 Profile 65 Profile 66 through hole 69 End face 81, 91 Electric wire common groove 82, 92 Electric wire common groove block 83, 93 Electric wire insertion through hole 84, 94 Cable

Claims (2)

[Claims] 1. A plurality of split pieces obtained by vertically splitting a circular pipe with a gap, a radial coupling link connecting the split pieces to a central axis, and a coupling link extending in the pipe longitudinal direction. A core for electric wire common groove concrete block manufacturing formwork characterized by comprising a raising / lowering device for tilting the divided piece to reduce the outer diameter of the divided piece, and a flexible cylindrical coating fitted on the outer periphery of the divided piece. . 2. A circular pipe having a cutout portion formed along a generatrix along a generatrix along the entire length of the cutout pipe and bent inward to be capable of reducing the diameter, and fitted into the cutout portion. An electric wire common groove concrete block manufacturing mold comprising: an insert piece that restores the circumference, a wedge that presses the insert piece into the cutout portion, and a flexible cylindrical coating that is externally fitted to the outer circumference of the circular pipe. Frame core.