Void device

Abstract

To provide a void device that can be reused when forming a vertical hole in a concrete surface while eliminating the need for disposal work with a reduced cost.SOLUTION: A void device that forms a vertical hole in a concrete surface when placing concrete comprises a core body 1 having a bar 12 erected from substantially a center of a bottom plate 11, a fixture 2 for fixing an upper end of the bar 12 in a suspended state to a crosspiece of a formwork used when placing concrete, an elastic body 3 formed by bonding an elastically deformable semi-circular elastic piece 31 in a substantially semi-cylindrical shape which is placed around the bar 12 below an upper end thereof while placed on the bottom plate 11, and a cylindrical body 4 made of synthetic resin, in which the outer peripheral surface of the elastic body 3 is pressed against the inner peripheral surface while the elastic body 3 is placed around the bar 12.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a void device for forming vertical holes in a concrete surface when placing concrete.

Background Art

[0002] Conventionally, in the work of forming vertical holes as if hollowed out from a concrete surface when performing construction using concrete, a void device is installed, concrete is poured around it, and after the concrete hardens, the void device is removed to form vertical holes in the concrete surface (see Patent Document 1).

[0003] This conventional void device includes a void tube body, an intermediate member spirally wound around the void tube body so as to be pullable out from the void tube body, and a tape member spirally wound around the void tube body via the intermediate member. This tape member is wound so that the side edge ends on one side overlap each other, and the overlapping portion of the tape member is fixed with an adhesive, and a gap portion is provided between the void tube body and the tape member.

[0004] And the extraction of the void device is completed by pulling out the intermediate member from between the void tube body and the tape member after the concrete hardens and pulling out the void tube body with the gap portion expanded. At this time, the tape member remains sticking to the vertical hole of the concrete.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] However, in the conventional void device, the intermediate member has to be pulled out between the void tube body and the tape member after the concrete has hardened, and it is very difficult to reuse the intermediate member. Therefore, every time a vertical hole is formed in the concrete surface, a new void device has to be prepared, which increases the cost. Moreover, the pulled-out intermediate member becomes garbage and requires labor for disposal work.

[0007] The present invention has been made in view of such points, and an object thereof is to provide a void device that can be reused when forming a vertical hole in the concrete surface, can eliminate the need for disposal work, and can reduce costs.

Means for Solving the Problems

[0008] To achieve the above object, the present invention is premised on a void device that forms a vertical hole in the concrete surface when placing the concrete. And, a core body with a rod erected from approximately the center of the bottom plate, a fixture that fixes the core body in a state where the upper end of the rod is suspended with respect to the crosspiece of the formwork used when placing the concrete, an elastic deformable substantially cylindrical elastic body disposed around the periphery below the upper end of the rod in a state of being placed on the bottom plate, and a synthetic resin cylindrical body whose outer peripheral surface presses against the inner peripheral surface in a state where the elastic body is disposed around the periphery below the rod. A thin elastic body having a substantially cylindrical shape that is laminated on the upper surface of the elastic body around the bar and is elastically deformable to press against the inner peripheral surface of the cylindrical body. It is characterized by comprising the above.

[0009] Also, the elastic body may be divided into a plurality around the rod.

[0010] Furthermore, the respective split surfaces of the plurality of split pieces divided around the rod may be fixed with an adhesive.

[0011] Also, the fixture may be provided with a fixing piece fixed to the crosspiece of the formwork and having an insertion hole through which the upper end of the rod is inserted, and a screwed member screwed to the fixing piece and pressing the upper end of the rod inserted through the insertion hole.

Advantages of the Invention

[0013] In short, when placing concrete, the upper end of the bar is fixed to the crosspiece of the formwork by a fixture, a substantially cylindrical elastic body centered on the suspended bar is placed on the bottom plate, and the outer peripheral surface of this elastic body is pressed against the inner peripheral surface of a cylindrical body made of synthetic resin. Then, after the concrete hardens, when the bar with the upper end fixation released by the fixture is pulled out with the elastic body placed on the bottom plate, the cylindrical body detaches from the contact surface with the concrete and a vertical hole is formed in the concrete surface.

[0014] At this time, when the bar is pulled out, the cylindrical body made of synthetic resin is released from the vertical hole in the concrete due to the pressing force of the elastic body. As a result, not only the bar and the fixture, but also the elastic body and the cylindrical body can be reused when forming the vertical hole in the concrete surface, eliminating the need for waste disposal work and reducing the cost of the void device.

[0015] Also, by dividing the elastic body into a plurality of parts centered on the bar, it is no longer necessary to form the elastic body into a substantially cylindrical shape, and a compact shape is sufficient. Due to the division of the elastic body, the mold for the divided pieces becomes compact, and space-saving in the molding operation can be achieved.

[0016] Furthermore, by fixing the dividing surfaces of the plurality of divided pieces centered on the bar with an adhesive, while making the molding operation of each divided piece compact due to the division of the elastic body, the function as a substantially cylindrical elastic body can be ensured.

[0017] Also, the upper end of the bar is inserted through the insertion hole of the fixing piece fixed to the crosspiece of the formwork, and this upper end of the bar is pressed as the screwing member screwed to the fixing piece is screwed, thereby functioning as a fixture. As a result, the fixture can be easily configured by the fixing piece having the insertion hole and the screwing hole and the screwing member.

[0018] Furthermore, by laminating a thin elastic body on the upper surface of the elastic body, the axial length of the elastic body is increased. Therefore, even if a part of the upper surface of the elastic body is located below the inclined concrete surface when the concrete surface is inclined, the axial length of the elastic body is increased by the thin elastic body, and the upper surface of the thin elastic body can be positioned above the inclined concrete surface. As a result, deformation of the cylindrical body due to concrete pressure during concrete placement is avoided by the thin elastic body, and a vertical hole can be formed smoothly even if the concrete surface is inclined.

Brief Description of the Drawings

[0019]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Figure 12

Figure 13

Figure 14

Figure 15

DETAILED DESCRIPTION OF THE INVENTION

[0020] Hereinafter, embodiments of the present invention will be described with reference to the drawings.

[0021] FIG. 1 is an exploded perspective view of a void device according to an embodiment of the present invention, and FIG. 2 is a perspective view of the void device shown in FIG. 1 before concrete placement.

[0022] As shown in FIGS. 1 and 2, X is a void device for forming a vertical hole when placing concrete. The void device X includes a core body 1 in which a rod 12 is erected from substantially the center of a bottom plate 11, a fixture 2 for fixing the rod 12 so that its upper end is suspended with respect to formworks A, A used when placing concrete, an elastic body 3 having a cylindrical shape that is shorter than the rod 12 and is placed on the bottom plate 11, and a cylindrical body 4 for pressing the outer peripheral surface of the elastic body 3 against the inner peripheral surface.

[0023] The bottom plate 11 is formed of a substantially rectangular flat plate that does not protrude from the lower surface of the elastic body 3. The rod 12 is made of a reinforcing bar, and its lower end is integrally fixed to substantially the center of the bottom plate 11. The formworks A, A are provided in a pair so as to face each other.

[0024] FIG. 3 is a side view of the void device X shown in FIG. 2 as seen from one formwork A side, and FIG. 4 is an enlarged view of the vicinity of the fixture 2 of the void device X shown in FIG. 3. FIG. 5 is a plan view of the void device X shown in FIG. 2 as seen from above, and FIG. 6 is a front view of the void device X shown in FIG. 2 as seen from the front side.

[0025] As shown also in FIGS. 3 to 6, the fixture 2 includes a fixing piece 21 attached to a crosspiece A1 installed above both formworks A, A, and a screwing member 22 screwed to the fixing piece 21 and pressing the upper end of the bar material 12. The crosspiece A1 is made of a plate material having a substantially rectangular cross section extending between both formworks A, A, and both ends thereof are fixed on pedestals A2, A2 respectively installed on the upper surfaces of both formworks A, A. Further, the screwing member 22 includes a screw portion 221 and a gripping portion 222 integrally provided at the base end of the screw portion 221 for tightening and loosening the screw portion 221 while gripping it by hand with respect to a screw hole 216 described later.

[0026] The fixing piece 21 is formed in a substantially U-shaped cross section connecting an upper piece 211 and a lower piece 212 longer than the upper piece 211 by a vertical piece 213 shorter than the thickness of the crosspiece A1. Insertion holes 214 (only the side of the upper piece 211 is shown in the figure) through which the upper end of the bar material 12 is inserted are provided in the upper piece 211 and the lower piece 212. Further, three nail holes 219, 219,... into which nail materials 215, 215,... are driven are provided in the upper piece 211 of the fixing piece 21 in a state where the tip of the lower piece 212 is in contact with the vertical surface of the crosspiece A1, and the fixing piece 21 is fixed to the upper surface of the crosspiece A1 by each driven nail material 215. Then, the void device X is fixed in a state of being positioned with respect to the crosspiece A1 by fixing the fixing piece 21 to the upper surface of the crosspiece A1.

[0027] Further, a screw hole 216 is provided in the vertical piece 213 of the fixing piece 21. A screwing member 217 that presses the upper end of the bar material 12 inserted through the insertion holes 214 of the upper piece 211 and the lower piece 212 from a direction perpendicular to its axis is screwed into the screw hole 216.

[0028] The elastic body 3 is a substantially cylindrical shape with an axial length of about 210 mm made of a recycled sponge material of polyurethane-based sponge. This elastic body 3 is formed in a substantially cylindrical shape by adhering semi-circular elastic pieces 31, 31 (divided pieces) having a substantially semi-cylindrical cross section divided into two around the bar material 12 with an adhesive (not shown). As the elastic body 3, a highly resilient one that can sufficiently rebound against the external pressure from the time of placing the concrete to the time of curing is applied.

[0029] Then, as the elastic body 3, a pulverizing process of pulverizing a recycled sponge material into chips, a molding process of putting the sponge in chip form pulverized by this pulverizing process and a plurality of other sponge chips together with a binder into a substantially cylindrical mold, heating with steam while compressing to form a recycled sponge body, and a finishing process of cutting the recycled sponge body formed by this molding process into a semi-cylindrical shape that becomes the product shape are performed to obtain a recycled sponge. At this time, by using a recycled sponge in which a plurality of other sponge chips are mixed, it is formed into a hardness that is preferred. Note that instead of a polyurethane-based sponge, a material suitable for bonding with an adhesive, such as a sponge material like urethane foam or polyethylene foam, may be used.

[0030] Also, as the adhesive for bonding the semi-circular elastic pieces 31, 31, an adhesive mainly made of SBS thermoplastic rubber (styrene-butadiene-based thermoplastic elastomer) is used. As this adhesive, any adhesive can be used as long as peeling does not occur when pulled out from concrete. Also, as the adhesive, synthetic adhesives and natural adhesives can also be used. At this time, examples of the synthetic adhesive include various copolymers such as styrene-butadiene-based, styrene-acrylic-based, ethylene-vinyl acetate-based, butadiene-methyl methacrylate-based, vinyl acetate-butyl acrylate-based, etc., and polyvinyl alcohol, maleic anhydride copolymer, acrylic acid-methyl methacrylate-based copolymer, etc. Also, if necessary, various auxiliaries such as a dispersant, thickener, water retention agent, defoaming agent, waterproofing agent, etc. may be appropriately used.

[0031] The cylindrical body 4 is made of a synthetic resin such as polyurethane (PU) in consideration of the peelability from the vertical hole T recessed in the substantially horizontal flat concrete surface K1. Since the cylindrical body 4 is formed on the concrete surface K1 with a diameter of 100 mm and the depth of the vertical hole T is set to about 200 mm, a cylindrical body with an axial length of about 240 mm is used. Since the axial length of the elastic body 3 press-fitted into the cylindrical body 4 is set to 210 mm, the elastic body 3 is located about 10 mm above the concrete surface K1, and the cylindrical body 4 is located about 40 mm above the concrete surface K1, respectively. Note that the cylindrical body 4 may be made of a synthetic resin such as polypropylene or polyethylene.

[0032] Here, the procedure for forming the vertical hole T by the void device X on the concrete surface K1 of the concrete K placed against the formworks A, A will be described.

[0033] First, both ends of the crosspiece A1 are fixed to the pedestals A2, A2 respectively installed on the upper surfaces of the two formworks A, A, and the fixing piece 21 is attached to the corresponding position of the crosspiece A1 corresponding to the upper side of the vertical hole T. At this time, the nail material 215 is driven into each nail hole 219 of the upper piece 211 so that the centers of the insertion holes 214 of the upper piece 211 and the lower piece 212 of the fixing piece 21 coincide with the central axis of the vertical hole T, and the fixing piece 21 is fixed to the corresponding position of the crosspiece A1.

[0034] Then, the rod 12 of the core 1 is inserted into the insertion holes 214 of the upper piece 211 and the lower piece 212 of the fixing piece 21 from below, and the screw part 221 of the screwing member 22 is tightened against the screw hole 216 of the vertical piece 213 to press and fix the upper end of the rod 12. At this time, when forming the vertical hole T with a depth of about 200 mm on the concrete surface K1 of the concrete K placed in the formworks A, A, with the upper end of the cylindrical body 4 about 40 mm above the concrete surface K1 and the upper end of the elastic body 3 about 30 mm above the concrete surface K1 respectively, with the rod 12 positioned, the screw part 221 of the screwing member 22 is tightened against the screw hole 216 to press and fix the upper end of the rod 12.

[0035] FIG. 7 is a perspective view of the void device X in FIG. 2 after concrete placement, FIG. 8 is a perspective view showing a state in which the fixture 2 of the void device X in FIG. 7 is removed after the concrete has hardened, and FIG. 9 is a perspective view showing a state in which the bar 12, the cylindrical body 4, and the elastic body 3 of the void device X in FIG. 8 are removed from the vertical hole, respectively.

[0036] As shown in FIGS. 7 to 9, after the concrete K has hardened, the screw member 22 is loosened to separate the screw portion 221 that presses the upper end of the bar 12, the nail members 215 are removed, and then the fixture 2 is removed from the cross member A1. As the two formworks A and A are detached, the cross member A1 and the pedestal A2 are removed. Then, the cylindrical body 4 is pulled out together with the bar 12 by the pressing force of the elastic body 3 to form a vertical hole T in the flat concrete surface K1.

[0037] Therefore, in this embodiment, when placing the concrete K, the upper end of the bar 12 is fixed to the cross member A1 of the two formworks A and A by the fixture 2, and the substantially cylindrical elastic body 3 centered on the suspended bar 12 is placed on the bottom plate 11. Since the outer peripheral surface of this elastic body 3 is in pressure contact with the inner peripheral surface of the synthetic resin cylindrical body 4, when the upper end fixing by the fixture 2 is released after the concrete K has hardened and the bar 12 is pulled out with the elastic body 3 placed on the bottom plate 11, the cylindrical body 4 is detached from the contact surface with the concrete K (the peripheral surface of the vertical hole T), and the vertical hole T is formed in the concrete surface K1.

[0038] At this time, when the bar 12 is pulled out, the synthetic resin cylindrical body 3 is released from the vertical hole T of the concrete K due to the pressing force of the elastic body 3. As a result, not only the bar 12 and the fixture 2, but also the elastic body 3 and the cylindrical body 4 can be reused when forming the vertical hole T in the concrete surface K1, eliminating the need for disposal work and reducing the cost of the void device X.

[0039] In addition, since the elastic body 3 is divided into two semi-circular elastic pieces 31 and 31 centered on the bar 12, it is not necessary to form the elastic body 3 into a substantially cylindrical shape, and a compact substantially semi-cylindrical shape is sufficient. By dividing the elastic body 3, the forming work of the semi-circular elastic pieces 31 and 31 can be made more compact.

[0040] Furthermore, since the dividing surfaces of the two semi-circular elastic pieces 31 divided into two with the bar 12 as the center are fixed by an adhesive, while making the forming work of each semi-circular elastic piece 31 compact by dividing the elastic body 3, the function as a substantially cylindrical elastic body 3 can be ensured.

[0041] Also, the upper end of the bar 12 is inserted into the insertion holes 214 of the upper and lower pieces 211, 212 of the fixing piece 21 fixed to the crosspiece A1 of the both formworks A, and by pressing the upper end of this bar 12 as the screwing member 22 screwed to the fixing piece 21 is accompanied, it functions as the fixture 2. Thereby, the fixture 2 can be easily configured by the fixing piece 21 having the upper and lower insertion holes 214 and the screwing holes 216 and the screwing member 22.

[0042] Next, a second embodiment of the present invention will be described with reference to FIGS. 10 to 15.

[0043] In this embodiment, the configuration of the elastic body when the concrete surface is inclined is changed. The configuration of the void device is the same as that of the first embodiment, and the same reference numerals are given to the same parts and the detailed description thereof is omitted.

[0044] FIG. 10 shows a perspective view before placing concrete in a state where a thin elastic body is laminated on the elastic body of the void device according to the second embodiment of the present invention. FIG. 11 shows a front view of the void device X in FIG. 10 as viewed from the front side, and FIG. 12 shows a perspective view of the void device X in FIG. 10 after placing concrete. Further, FIG. 13 shows a side view of the void device X in FIG. 10 as viewed from the side with one formwork A removed, FIG. 14 shows a perspective view of the void device X in FIG. 13 removed from the vertical hole T after the concrete has hardened, and FIG. 15 shows a side view of the void device X in FIG. 13 removed from the vertical hole T after the concrete has hardened as viewed from the side.

[0045] That is, in this embodiment, as shown in FIGS. 10 and 11, both ends of the crossbar A1 are fixed to the upper ends of the formworks A and A. This crossbar A1 is installed on the upper ends of the formworks A and A in a substantially horizontal state. At this time, as shown in FIGS. 12 to 15, the concrete K placed on the formworks A and A may form a sloping concrete surface K2 on the surfaces of the formworks A and A facing each other. In that case, the concrete surface K2 slopes such that one side of the formworks A and A (the right side in FIG. 13) is at a higher position and the other side (the left side in FIG. 13) is at a lower position.

[0046] Also, if the concrete surface K2 is sloped and there is a height difference, the concrete K will cover more on the mountain side (the higher position side of the concrete surface K2) than on the valley side (the lower position side of the concrete surface K2) of the cylindrical body 4 of the void device X, and the mountain side of the elastic body 3 may be located below the concrete surface K2. For this reason, if the repulsive force from the elastic body 3 cannot be obtained on the mountain side of the cylindrical body 4, the deformation of the cylindrical body due to the concrete pressure during the placement and hardening of the concrete K will be inevitable. Therefore, a thin elastic body 5 having a substantially cylindrical shape is laminated on the upper surface of the elastic body 3 around the bar 12 to raise the height of the elastic body 3, and the thin elastic body 5 that can be elastically deformed is pressed against the inner peripheral surface of the cylindrical body 4 by the repulsive force.

[0047] This thin elastic body 5 is also made of a recycled sponge material made of a polyurethane-based sponge, similar to the elastic body 3, and has a thin substantially cylindrical shape with an axial length of about 20 mm. This thin elastic body 5 is formed in a thin substantially cylindrical shape around the bar 12 and is provided with an insertion hole 51 for passing through the bar 12. As the thin elastic body 5, a highly resilient one that can sufficiently repel the external pressure from the placement to the hardening of the concrete K is applied. Note that instead of the polyurethane-based sponge, a material suitable for bonding with an adhesive, such as a sponge material like urethane foam or polyethylene foam, may be used.

[0048] At this time, when forming the vertical hole T with a depth of about 200 mm in the concrete surface K2 of the concrete K placed in the formworks A and A, it is necessary to set the depth based on the valley side (lower side) of the vertical hole T. Therefore, with the rod 12 positioned such that the upper end of the valley side of the cylindrical body 4 is about 40 mm above the concrete surface K2 and the upper end of the valley side of the elastic body 3 is about 30 mm above the concrete surface K1, the screw portion 221 of the screw member 22 is tightened against the screw hole 216 to press and fix the upper end of the rod 12.

[0049] Therefore, in the present embodiment, by laminating the thin elastic body 5 on the upper surface of the elastic body 3, the axial length of the elastic body 3 is increased. For this reason, even if the peak side of the upper surface of the elastic body 3 is located below the inclined concrete surface K2, the axial length of the elastic body 3 is increased by the thin elastic body 5, and it becomes possible to position the upper surface of the thin elastic body 5 above the inclined concrete surface K2. Thereby, even if the concrete surface K2 is inclined, the deformation of the cylindrical body 4 due to the pressure of the concrete K during placement and hardening is avoided by the thin elastic body 5, and the vertical hole T can be smoothly formed in the inclined concrete surface K2.

[0050] Note that the present invention is not limited to the above-described embodiments, and includes various other modification examples. For example, the diameter or length can be appropriately changed without departing from the gist. In the above-described embodiments, the vertical hole T formed in the concrete surfaces K1 and K2 is set to have a diameter of 100 mm and a depth of about 200 mm, but the vertical hole may be set to have a diameter of 50 mm to 300 mm and a depth of 100 mm to 600 mm. In that case, considering the use of the thin elastic body when it is necessary to incline the concrete surface, it is also possible to anticipate a margin of about 20% of the depth of the vertical hole in the axial length of the cylindrical body with respect to the depth of the vertical hole.

[0051] Also, in the above-described embodiments, the elastic body 3 is divided into two semi-circular elastic pieces 31 and 31, but it may be divided into three or more around the rod, or on the other hand, it may remain in a substantially cylindrical shape without being divided.

[0052] Furthermore, in each of the above embodiments, the split surfaces of the two split semi-circular elastic pieces 31, 31 are adhered to each other with an adhesive. However, the semi-circular elastic pieces may be inserted into the inside of the cylindrical body without being adhered to each other with an adhesive and then inserted through the bar material.

[0053] Also, in the second embodiment, the thin elastic body 5 is formed in a single thin cylindrical shape. However, the thin elastic body may be divided into a plurality of divided pieces centered on the bar material.

Explanation of Reference Numerals

[0054] 1 Core 11 Bottom plate 12 Bar material 2 Fixture 21 Fixed piece 214 Insertion hole 22 Screwing member 3 Elastic body 31 Semi-circular elastic piece (divided piece) 4 Cylindrical body 5 Thin elastic body A Mold A1 Crossbar K Concrete K1 Concrete surface K2 Concrete surface T Vertical hole X Void device

Claims

1. A void device for forming vertical holes on a concrete surface when placing concrete, comprising: a core body with a rod erected from approximately the center of the bottom plate; a fixture for fixing the core body in a state where the upper end of the rod is suspended with respect to the crossbar of the formwork used when placing the concrete; an elastic and substantially cylindrical elastic body disposed around the periphery below the upper end of the rod in a state where it is placed on the bottom plate with the rod as the center; a cylindrical body made of synthetic resin whose outer peripheral surface is in pressure contact with the inner peripheral surface in a state where the elastic body is disposed around the periphery below the rod; a thin elastic and substantially cylindrical elastic body laminated on the upper surface of the elastic body with the rod as the center and in pressure contact with the inner peripheral surface of the cylindrical body; and characterized by comprising the above components. A void device.

2. The void device according to claim 1, wherein the elastic body is divided into a plurality of parts with the rod as the center.

3. The void device according to claim 2, wherein each divided piece divided into a plurality of parts with the rod as the center has its respective dividing surface fixed by an adhesive.

4. The fixture comprises: a fixing piece fixed to the crossbar of the formwork and having an insertion hole through which the upper end of the rod is inserted; a screwed member screwed to the fixing piece and pressing the upper end of the rod inserted through the insertion hole; and the void device according to any one of claims 1 to 3.

Images