Position indicator for through hole formation

Abstract

After the concrete surface has been leveled by a concrete floor finishing device, the location of through-holes to be formed in the floor slab can be appropriately indicated. [Solution] The through-hole formation position indicator 1 is installed on the upper side of the formwork before the concrete 130 is poured, and displays the position of the through-hole after the concrete 130 has been poured. The position indicator 1 comprises a base 2 installed at the position of the through-hole, a shaft 3 protruding upward from the base 2, and a position indicator member 6 attached to the shaft 3, which protrudes in an upright position from the upper surface 131 of the concrete 130 after the concrete 130 has been poured. When finishing work is performed on the concrete floor surface after the concrete 130 has been poured, the position indicator member 6 changes its posture from an upright position to a sideways position due to the stress received from the rotary trowel, allows the rotary trowel to pass over it in the sideways position, and returns from the sideways position to an upright position after the rotary trowel has passed.

Description

Technical Field

[0001] The present invention relates to a position indicator for forming through holes, which indicates positions where through holes are to be formed after concrete is placed on the floor surface of a building.

Background Art

[0002] At a construction site, concrete is placed in a formwork to form a floor slab. The formwork is composed of plate materials such as concrete panels, deck plates, wooden frames, and resin frames. Conventionally, when placing concrete, a building embedment for indicating the upper surface height level of the concrete is used (for example, Patent Document 1). This building embedment fixes a pedestal at a predetermined position on a formwork such as a deck plate, and adjusts the upper surface height level of the concrete by vertically moving a top end display portion erected from the pedestal. When placing concrete, the concrete is poured with the upper surface height level indicated by the top end display portion as a mark.

[0003] When concrete is placed on the formwork, a floor slab is formed by leveling the upper surface of the concrete using a concrete floor finishing device called a trowel (for example, Patent Documents 2 and 3). The concrete floor finishing device levels the upper surface of the concrete by rotating one or more rotary floats at high speed. At this time, a rectangular rod-shaped body provided at the upper end of a building embedment embedded in the placed concrete protrudes upward from the upper surface of the concrete. Therefore, when the concrete floor finishing device levels the upper surface of the concrete, the rectangular rod-shaped body is broken by the rotary float rotating at high speed and scattered around. Therefore, when the concrete floor finishing device finishes leveling the entire upper surface of the concrete, it becomes difficult to determine where the building embedment is embedded.

[0004] Incidentally, in buildings, pipes and cables are sometimes arranged vertically, spanning across upper and lower floors. In this case, after the concrete poured onto the formwork has sufficiently dried and hardened, a core drilling operation is performed using a core drilling cutter such as a diamond hole saw to create through-holes that penetrate vertically through the floor slab and formwork. Pipes and cables are then placed in these through-holes.

[0005] However, the locations where through-holes are to be formed in the floor slab of a building are predetermined. Therefore, if the location of the through-holes to be formed on the upper surface of the floor slab is unknown when performing core drilling, the work efficiency will be significantly reduced. To prevent this, it is preferable to, for example, install position indicators on the formwork at the planned locations for through-hole formation before the concrete is poured, and to leave a part of the position indicators protruding from the upper surface of the concrete after the concrete has been poured.

[0006] Furthermore, multiple through-holes may be formed in the floor slab. For example, the diameter of the through-holes formed in the floor slab may differ depending on their location, and different contractors may perform the core drilling work. Therefore, it is preferable that the position indicators installed on the formwork be of different types depending on the hole diameter and the contractor, so that the hole diameter and contractor can be distinguished even after the concrete has been poured. [Prior art documents] [Patent Documents]

[0007] [Patent Document 1] Design Registration No. 1141405 Gazette [Patent Document 2] Japanese Patent Publication No. 2004-225523 [Patent Document 3] Japanese Patent Publication No. 2015-196994 [Overview of the Initiative] [Problems that the invention aims to solve]

[0008] However, the conventional building-mounted fixtures mentioned above cannot be used as position indicators to be pre-installed on the formwork. This is because, as mentioned above, the conventional building-mounted fixtures lose their position indicator function when the angular rod-shaped part breaks due to the high-speed rotating trowel while the concrete surface is being leveled by the concrete floor finishing device.

[0009] Furthermore, even if the angular rod-shaped object does not break, a large amount of concrete will adhere to it during the leveling process using the concrete floor finishing device. Therefore, even if multiple rod-shaped objects are protruding from the concrete surface, it is difficult to distinguish the hole diameter or the contractor because of the large amount of concrete attached to them.

[0010] The present invention was made to solve the above problems, and aims to provide a through-hole formation position indicator that can indicate the position of through-holes to be formed in a floor slab after the concrete surface has been leveled by a concrete floor finishing device. [Means for solving the problem]

[0011] To achieve the above objective, firstly, the present invention provides a through-hole formation position indicator that is installed on the upper surface of a formwork before concrete is poured and indicates the position of the through-hole after concrete pouring, comprising: a base installed at the position of the through-hole formation; a shaft portion protruding upward from the base; and a position indicator member attached to the shaft portion and protruding in an upright position from the upper surface of the concrete after concrete pouring, wherein the position indicator member changes its position from an upright position to a sideways position due to the stress received from a rotary trowel when finishing work is performed on the concrete floor surface after concrete pouring, allows the rotary trowel to pass over the sideways position, and returns from the sideways position to the upright position after the rotary trowel has passed.

[0012] Secondly, the present invention relates to a position indicator for forming through holes having the first configuration described above, characterized in that the position indicator member is made of a hollow tubular elastic member.

[0013] Thirdly, the present invention relates to a through-hole formation position indicator having the second configuration described above, characterized in that the elastic member is colored with a color corresponding to the diameter or type of the through-hole.

[0014] Fourth, the present invention relates to a through-hole forming position indicator having the first configuration described above, characterized in that the position indicator member is composed of a brush member having a large number of brush bristles.

[0015] Fifth, the present invention relates to a through-hole forming position indicator having the fourth configuration described above, characterized in that the brush bristles are colored according to the diameter or type of the through-hole.

[0016] Sixth, the present invention relates to a through-hole formation position indicator having any of the first to fifth configurations described above, characterized in that the shaft portion is expandable and contractible according to the height level of the upper surface of the concrete.

[0017] Seventh, the present invention relates to a through-hole forming position indicator having any of the first to fifth configurations described above, characterized in that the lower surface of the base is fixed to the upper surface of the formwork.

[0018] Eighth, the present invention relates to a through-hole formation position indicator having any of the first to fifth configurations described above, characterized in that a sleeve is installed on the formwork at the through-hole formation position, a cover is provided on the upper end of the sleeve, and the lower surface of the base is fixed to the upper surface of the cover. [Effects of the Invention]

[0019] According to the present invention, after the upper surface of the concrete is leveled by the concrete floor finishing device, the position of the through hole formed in the floor slab and the like can be appropriately indicated.

Brief Description of the Drawings

[0020] [Figure 1] It is a figure which shows the structural example of the position indicator for through-hole formation in 1st Embodiment. [Figure 2] It is a figure which shows the installation example of the position indicator for through-hole formation with respect to a deck plate. [Figure 3] It is a figure which shows the operation | movement of a rotary float. [Figure 4] It is a perspective view which shows the behavior of a rotary float and an elastic member when finishing work is being performed. [Figure 5] It is sectional drawing which looked at the attitude | position change of an elastic member from the side. [Figure 6] It is sectional drawing which looked at the attitude | position change of an elastic member from the side. [Figure 7] It is a figure which shows an elastic member before and after finishing work. [Figure 8] It is a figure which shows the example of the operation which peels the concrete adhering to an elastic member. [Figure 9] It is sectional drawing which shows the position indicator for through-hole formation provided with the anti-separation function of an elastic member. [Figure 10] It is a perspective view which shows the position indicator for through-hole formation in 2nd Embodiment. [Figure 11] It is a figure which shows the installation example of the position indicator for through-hole formation. [Figure 12] It is a figure which shows the state where concrete was placed on the upper surface side of a deck plate. [Figure 13] It is a figure which shows the structural example of the position indicator for through-hole formation in 3rd Embodiment.

Modes for Carrying Out the Invention

[0021] Preferred embodiments of the present invention will be described in detail below with reference to the drawings. In the drawings referred to below, common components are denoted by the same reference numerals, and redundant explanations of them will be omitted.

[0022] (First Embodiment) A first embodiment of the present invention will be described. Figure 1 is a diagram showing an example of the configuration of the through-hole formation position indicator 1 (hereinafter simply referred to as "position indicator 1") in the first embodiment. Figure 1(a) shows a perspective view of the position indicator 1, and Figure 1(b) shows a cross-sectional view of the position indicator 1. This position indicator 1 is installed on the upper surface of the formwork before concrete is poured and is an indicator that displays the formation position of the through-hole after concrete is poured. In this embodiment, a deck plate 100 (see Figure 2) will be used as an example of the formwork on which concrete is poured.

[0023] The position indicator 1 comprises a base 2 installed at the location where the through-hole is formed, a shaft portion 3 protruding upward from the base 2, and a position indicator member 6 attached to the tip of the shaft portion 3, which protrudes in an upright position from the top surface of the concrete after concrete is poured. The base 2 is made of, for example, a disc-shaped plate, and has holes 2a formed at multiple locations in the circumferential direction for driving screws. The base 2 may be made of metal or resin. Furthermore, the base 2 is not limited to a disc-shaped plate, but may also be a rectangular plate.

[0024] The shaft portion 3 is erected in the center of the base 2. For example, the shaft portion 3 has a first shaft portion 4 and a second shaft portion 5. The first shaft portion 4 is integrally formed with the base 2 and is erected in the center of the base 2. The first shaft portion 4 extends to a predetermined height from the upper surface of the base 2, and a male screw 4a is formed on its outer circumferential surface. The second shaft portion 5 is a cylindrical member that is attached to the male screw 4a of the first shaft portion 4. A female screw 5a that screws into the male screw 4a is formed on the inside of the second shaft portion 5. Therefore, the second shaft portion 5 is attached to the first shaft portion 4 by screwing the female screw 5a into the male screw 4a of the first shaft portion 4. The second shaft portion 5 may be made of metal or resin.

[0025] The position indicator member 6 is attached to the tip of the shaft portion 3 and protrudes further upward from the shaft portion 3. In this embodiment, the position indicator member 6 is attached to the tip of the second shaft portion 5. The position indicator member 6 is made of a resilient material. Therefore, the position indicator member 6 is easily deformed when force is applied and has good recovery properties from that deformation. In this embodiment, the position indicator member 6 is made of an elastic member 7 formed in the shape of a hollow sleeve. The material of the elastic member 7 is, for example, a rubber material such as natural rubber or synthetic rubber. Rubber materials have excellent deformability and recovery properties from a deformed state.

[0026] The inner diameter of the elastic member 7 is the same as or slightly smaller than the outer diameter of the second shaft portion 5. The lower end of the elastic member 7 is attached to the tip of the second shaft portion 5. Therefore, the elastic member 7 is held in an upright position by the shaft portion 3, and its upper end is held at a predetermined height from the tip of the second shaft portion 5. Because the elastic member 7 is sleeve-shaped, when it is mounted on the second shaft portion 5 in an upright position, it forms a hollow space 8 inside it.

[0027] Since the first shaft portion 4 and the second shaft portion 5 are screwed together by a male screw 4a and a female screw 5b, the mounting depth between the second shaft portion 5 and the first shaft portion 4 can be adjusted by rotating the second shaft portion 5. In other words, the shaft portion 3 is extendable and retractable in its axial direction. By extending and retracting the shaft portion 3, the height position of the elastic member 7 from the base 2 can be adjusted.

[0028] Figure 2 shows an example of the installation of the position indicator 1 on the deck plate 100. Figure 2(a) shows the state before the concrete 130 is poured, and Figure 2(b) shows the state after the concrete 130 has been poured. As shown in Figure 2(a), the deck plate 100 is formed as a corrugated steel plate in which valleys 101 and peaks 102 are continuous at a predetermined pitch in the horizontal direction. The position indicator 1 is attached to the planned position of the through hole that penetrates the upper and lower floors. Therefore, the position indicator 1 may be attached to both the valleys 101 and peaks 102 of the deck plate 100. In Figure 2(a), the position indicator 1a is shown as an example attached to the valley 101, and the position indicator 1b is shown as an example attached to the peak 102. In addition, reinforcing bars 110 are arranged in a crisscross pattern on the upper surface of the deck plate 100. These reinforcing bars 110 are embedded in the concrete 130 that is poured afterward. Furthermore, reinforcing bars for openings, which are not shown in the illustration, are pre-attached to the reinforcing bars 110 located around the planned position for the through-hole.

[0029] The position indicator 1a, which is attached to the valley 101 of the deck plate 100, is fixed to the base 2 at the position where a through hole is formed on the upper surface of the valley 101 via screws 105 or the like. Note that the method of fixing the base 2 is not limited to screws 105. For example, the base 2 may be fixed to the upper surface of the valley 101 using double-sided tape or the like. Once the base 2 is fixed to the valley 101, the length of the shaft portion 3 of the position indicator 1a is adjusted so that the elastic member 7 is positioned above the concrete upper surface height level 120. At this time, the upper end 3a of the shaft portion 3 is positioned below the concrete upper surface height level 120, and the upper end 7a of the elastic member 7 is positioned above the concrete upper surface height level 120. Note that the concrete upper surface height level 120 is the height level defined by conventional building embedded fixtures, etc.

[0030] Similarly, the position indicator 1b attached to the ridge 102 of the deck plate 100 is fixed to the base 2 at the position where the through hole is formed on the upper surface of the ridge 102 via screws 105 or the like. In this case, the fixing method is not limited to using screws 105, but may also be done using, for example, double-sided tape. Once the base 2 is fixed to the ridge 102, the length of the shaft portion 3 of the position indicator 1b is adjusted so that the elastic member 7 is positioned above the concrete upper surface height level 120. At this time, the upper end 3a of the shaft portion 3 is positioned below the concrete upper surface height level 120, and the upper end 7a of the elastic member 7 is positioned above the concrete upper surface height level 120.

[0031] Subsequently, concrete 130 is poured up to the top surface height level 120 of the concrete, resulting in the state shown in Figure 2(b). Once the concrete 130 is poured, the elastic members 7 of the position indicators 1a and 1b protrude from the top surface 131 of the concrete 130. In other words, the elastic members 7 are not embedded in the poured concrete 130.

[0032] The elastic member 7 protruding from the upper surface 131 of the concrete 130 indicates the location of the through-hole formation. Furthermore, the elastic member 7 is colored according to the diameter or type of the through-hole to be formed at that location. Therefore, the elastic member 7 protruding from the upper surface 131 of the concrete 130 can not only indicate the location of the through-hole formation, but also indicate the diameter and type of the through-hole.

[0033] Immediately after the concrete 130 is poured, the top surface 131 of the concrete 130 is not flat. Therefore, after the concrete 130 is poured onto the deck plate 100, a finishing process is carried out to level the top surface 131 of the concrete 130 using a concrete floor finishing device called a trowel. The concrete floor finishing device has, for example, multiple rotary trowels arranged radially, and by moving these multiple rotary trowels along the top surface 131 of the concrete 130 while rotating them at high speed, the top surface of the concrete 130 is leveled.

[0034] Figure 3 shows the operation of the rotary trowel 140. The rotary trowel 140 moves in the direction of arrow F while leveling the upper surface 131 of the concrete 130. If the position indicator 1 is present in this direction of movement, the rotary trowel 140 will come into contact with the position indicator 1. At this time, the upper end 3a of the shaft portion 3 is lower than the upper surface 131 of the concrete 130, so it does not come into contact with the rotary trowel 140. Therefore, the shaft portion 3 does not damage the rotary trowel 140. Since the position indicator 1 has only the elastic member 7 protruding from the upper surface 131 of the concrete 130, the rotary trowel 140 comes into contact with the side surface of the elastic member 7.

[0035] Figure 4 is a perspective view showing the behavior of the rotary trowel 140 and the elastic member 7 during finishing work. Figure 4(a) shows the state just before the rotary trowel 140 hits the elastic member 7. Figure 4(b) shows the state as the rotary trowel 140 passes the installation position of the elastic member 7. Figure 4(c) shows the state after the rotary trowel 140 has passed the installation position of the elastic member 7. As shown in Figure 4(a), before the rotary trowel 140 hits it, the elastic member 7 maintains an upright position. When the rotary trowel 140 hits the side of the elastic member 7, the elastic member 7 changes its position from an upright position to a sideways position, as shown in Figure 4(b). At this time, the elastic member 7 is sleeve-shaped and hollow inside, so it changes to a sideways position while flattening, and therefore has the characteristic of easily changing from an upright position to a sideways position. The rotary trowel 140 smooths the concrete 130 as it passes over the elastic member 7, which has changed to a horizontal position. When the rotary trowel 140 passes the installation position of the elastic member 7, the elastic member 7 returns to its original upright position as shown in Figure 4(c).

[0036] Figures 5 and 6 are cross-sectional views of the change in posture of the elastic member 7 as described above, viewed from the side. As shown in Figure 5(a), before the rotary trowel 140 makes contact, the elastic member 7 maintains an upright posture. When the rotary trowel 140 hits the side of the elastic member 7, as shown in Figure 5(b), the elastic member 7 changes its posture from an upright posture to a lying-down posture. At this time, the elastic member 7 deforms flattened while the inner hollow space 8 contracts. Subsequently, as the rotary trowel 140 passes over the elastic member 7, the elastic member 7 becomes lying-down in a nearly flattened state, as shown in Figure 6(a), and is embedded in the concrete 130. At this time, the hollow space 8 of the elastic member 7 is compressed, and the volume embedded in the concrete 130 is minimized. Therefore, the entire elastic member 7 is completely embedded in the concrete 130, and the rotary trowel 140 passes over it.

[0037] Here, if the elastic member 7 is a solid member rather than a hollow sleeve, it will not flatten out even when placed on its side. Therefore, when a solid elastic member 7 is placed on its side and embedded in the concrete 130, its volume increases, and it receives significant resistance from the concrete 130. Due to this resistance, the elastic member 7 may not be completely embedded in the concrete 130. As a result, when the rotary trowel 140 moves, it may scrape away the elastic member 7, and in the worst case, it may break the elastic member 7.

[0038] In contrast, the elastic member 7 of this embodiment is hollow and sleeve-shaped, so when it is placed on its side as described above, it deforms into a flattened state and collapses almost completely flat, becoming completely embedded in the concrete 130. Therefore, the rotary trowel 140 slides over the flattened elastic member 7 without damaging it.

[0039] Then, as the rotary trowel 140 passes over the elastic member 7, as shown in Figure 6(b), the elastic member 7 is displaced in the direction indicated by arrow X due to its return property (restoring force), returning from a lying position to its original upright position. As a result, the elastic member 7 returns to a state where it protrudes from the upper surface 131 of the concrete 130, and does not lose its function of indicating the position of the through-hole formation.

[0040] The position indicator 1 allows the elastic member 7 to repeatedly undergo the aforementioned changes in posture, even when multiple rotary trowels 140 repeatedly strike the elastic member 7. Therefore, the position indicator 1 effectively utilizes the position indicator function of the elastic member 7 even after finishing work has been performed by the concrete floor finishing device, displaying the formation position of the through-hole.

[0041] When the elastic member 7 returns to its upright position, a trace 132 remains on the upper surface 131 of the concrete 130, as shown in Figure 6(b), indicating where the elastic member 7 was embedded when it was lying on its side. This trace 132 remains on the upper surface 131 of the concrete 130 even after the concrete 130 has hardened. However, this trace 132 is removed when a through-hole is formed around the location of the elastic member 7 by core drilling using a core drilling cutter such as a diamond hole saw. Therefore, the presence of the trace 132 does not pose a problem in the finishing work.

[0042] However, the trace 132 is formed in a circular region with a radius corresponding to the length of the elastic member 7 protruding from the upper surface 131 of the concrete 130. Therefore, if the protruding length of the elastic member 7 is greater than the radius of the through hole, the trace 132 will remain on the upper surface 131 of the concrete 130 even after the through hole is formed, which is undesirable as a floor surface finish for the concrete 130. For this reason, when installing the position indicator 1 before pouring the concrete 130, it is preferable to set the height position of the upper end 7a of the elastic member 7 protruding from the upper surface height level 120 of the concrete 130 at a position lower than the radius of the through hole.

[0043] Furthermore, as described above, the elastic member 7 is colored according to the diameter or type of the through hole formed at its location. However, during the finishing work using the concrete floor finishing device, the elastic member 7 is repeatedly embedded in the concrete 130. As a result, once the finishing work is complete, concrete 130 adheres to the surface of the elastic member 7, making it difficult to distinguish its color.

[0044] Figure 7 shows the elastic member 7 before and after finishing work. Figure 7(a) shows the elastic member 7 before finishing work is performed, and Figure 7(b) shows the elastic member 7 after finishing work is performed. In Figure 7(a), two position indicators 1a and 1b are installed at two locations on the upper surface 131 of the concrete 130, and an example is shown where the elastic member 7 of the two position indicators 1a and 1b are of different colors. In this case, immediately after the concrete 130 is poured, the concrete 130 does not adhere to the elastic member 7, so the colors of the elastic member 7 indicated by each position indicator 1a and 1b can be distinguished.

[0045] However, when the finishing work is carried out on the upper surface 131 of the concrete 130, the concrete 130 adheres to the outer surface of the elastic member 7, as shown in Figure 7(b). In this state, it is difficult to distinguish the color of the elastic member 7, and it is not possible to identify the diameter or type of the through-hole indicated by the position indicators 1a and 1b. However, since the elastic member 7 of this embodiment is a hollow sleeve-shaped elastic member, the concrete 130 adhering to the outer surface can be easily peeled off.

[0046] Figure 8 shows an example of an operation to remove concrete 130 adhering to the elastic member 7. As shown in Figure 8(a), after finishing work, concrete 130 is adhering to the outer surface of the elastic member 7. Since the elastic member 7 is hollow sleeve-shaped, it deforms easily when external force is applied. For example, as shown in Figure 8(b), if the outer surface of the elastic member 7 is pinched with the fingertips and flattened, the elastic member 7 deforms. As the surface shape of the elastic member 7 changes, the concrete 130 peels off from the outer surface of the elastic member 7. As a result, as shown in Figure 8(c), the elastic member 7's surface is exposed, and the colored color becomes discernible. Therefore, the worker can check the color of the elastic member 7 with the concrete 130 adhering to it by performing a simple operation on the elastic member 7, and can identify the diameter or type of the through-hole indicated by the position indicator 1.

[0047] For example, if the position indicator member 6 provided on the position indicator 1 is a member that does not undergo elastic deformation and does not change its surface shape, it is difficult to remove the concrete 130 adhering to its surface. In particular, once the concrete 130 has hardened, it is extremely difficult to remove the concrete 130 from the surface of the position indicator member 6. However, since the elastic member 7 of this embodiment can change its surface shape as described above, the concrete 130 adhering to its surface can be easily removed as described above, resulting in excellent workability.

[0048] Furthermore, the position indicator 1 described above repeatedly changes its orientation from an upright position to a sideways position during finishing work by the concrete floor finishing device. If such orientation changes are repeated, there is a possibility that the elastic member 7 may detach from the tip of the second shaft portion 5. To prevent this, it is preferable that the position indicator 1 be equipped with a function to prevent the elastic member 7 from detaching.

[0049] Figure 9 is a cross-sectional view showing a position indicator 1 equipped with a function to prevent the elastic member 7 from detaching. This position indicator 1 has an engaging portion 3b at the tip of the shaft portion 3 (more specifically, the tip of the second shaft portion 5). The engaging portion 3b is formed in a flange shape that protrudes outward from the outer circumferential surface of the tip of the second shaft portion 5. On the other hand, the elastic member 7 has a reduced-diameter portion 7b in which the inner diameter is reduced near its lower end. When the elastic member 7 is attached to the tip of the second shaft portion 5, the upper end of the reduced-diameter portion 7b is engaged with the lower surface of the engaging portion 3b. This provides an anti-detachment effect for the elastic member 7. That is, even if the elastic member 7 is subjected to repeated changes in posture from an upright position to a sideways position, and a force is applied in the direction of pulling it out from the tip of the second shaft portion 5, the lower end of the elastic member 7 will not detach from the tip of the second shaft portion 5 because the reduced-diameter portion 7b and the engaging portion 3b are engaged. Note that the engaging portion 3b is not limited to a flange shape, but may also be formed in a groove shape.

[0050] As described above, the position indicator 1 of this embodiment comprises a base 2 installed on the upper surface of the deck plate 100 at the position where the through hole is to be formed before the concrete 130 is poured, a shaft portion 3 protruding upward from the base 2, and a position indicator member 6 attached to the tip of the shaft portion 3, which protrudes in an upright position from the upper surface 131 of the concrete 130 after the concrete 130 is poured. When finishing work is performed on the floor surface (upper surface 131) of the concrete 130 after the concrete 130 has been poured, the position indicator member 6 changes its posture from an upright position to a sideways position due to the stress received from the rotary trowel 140, passes the rotary trowel 140 while in the sideways position, and returns from the sideways position to an upright position after the rotary trowel 140 has passed. The position indicator 1 having such a configuration will not break during the finishing work to level the upper surface 131 of the concrete 130, and will not lose its position indicator function even after the finishing work is completed. Therefore, it is possible to appropriately indicate the location of the through-holes after the concrete 130 has hardened.

[0051] Furthermore, the position indicator 1 has the characteristic that the shape of the position indicator member 6 changes easily as the rotary trowel 140 passes over it, to the point where the position indicator member 6 changes from an upright position to a sideways position. Therefore, even if concrete 130 adheres to the surface of the position indicator member 6 after the finishing work is completed, the concrete 130 can be easily removed by changing the shape of the position indicator member 6. Thus, the position indicator 1 can not only indicate the position of the through-holes to be formed in the floor slab after the finishing work on the upper surface 131 of the concrete 130 is completed, but can also indicate the diameter and type of the through-holes.

[0052] In this embodiment in particular, the position indicator member 6 described above is composed of a hollow tubular elastic member 7. Therefore, when the elastic member 7 is in a lying position and the rotary trowel 40 passes over the elastic member 7, the elastic member 7 is completely embedded in the concrete 130 in a flattened state. As a result, the rotary trowel 140 does not damage the elastic member 7. After the rotary trowel 140 has passed, the elastic member 7 returns to its original upright position as a hollow tube.

[0053] (Second Embodiment) Next, a second embodiment of the present invention will be described. In the first embodiment, an example was given in which a through hole is formed using a core drilling cutter such as a diamond hole saw. However, the method for forming a through hole in a floor slab into which concrete 130 has been poured is not necessarily limited to the method using a core drilling cutter. For example, a sleeve may be installed in advance at the through hole formation position of the deck plate 100, and concrete 130 may be poured with a cover placed over the upper opening of the sleeve. In this embodiment, a position indicator 1 used in such a through hole formation method will be described.

[0054] Figure 10 is a perspective view showing the position indicator 1 in this embodiment. Similar to the first embodiment, this position indicator 1 comprises a base 2 installed at the position where the through hole is formed, a shaft portion 3 protruding upward from the base 2, and a position indicator member 6 attached to the tip of the shaft portion 3, which protrudes in an upright position from the top surface of the concrete after concrete is poured. The shaft portion 3 is integrally formed with the base 2. The shaft portion 3 in this embodiment consists only of the portion fixed to the base 2. This shaft portion 3 is erected at a predetermined height in the central part of the base 2. The height of the shaft portion 3 does not need to be very high, as long as the lower end of the position indicator member 6 can be attached. The position indicator member 6 is attached to its shaft portion 3 and is held in an upright position protruding above the shaft portion 3. In this embodiment as well, the example shown is that the position indicator member 6 is composed of a hollow sleeve-shaped elastic member 7.

[0055] Figure 11 shows the position indicator 1 installed on the upper surface of the deck plate 100. This position indicator 1 is installed on a sleeve 150 which is installed on the deck plate 100. The sleeve 150 is a hollow member installed so as to surround a hole 106 that is pre-formed in the deck plate 100 on which it is installed. In Figure 11, an example is shown in which the hole 106 is formed in the ridge 102 of the deck plate 100, and the sleeve 150 is installed on the ridge 102 so as to surround the hole 106. Preferably, the lower end of the sleeve 150 is fixed to the deck plate 100 with screws or the like. A cover 151 is placed over the upper end of the sleeve 150, and the opening of the sleeve 150 is closed by the cover 151.

[0056] As shown in Figure 11, the position indicator 1 of this embodiment is installed on a cover 151 provided at the upper end of the sleeve 150. That is, the lower surface of the base 2 is fixed to the upper surface of the cover 151. At this time, the position indicator 1 is installed such that the upper end 3a of the shaft portion 3 is below the concrete upper surface height level 120, and the upper end 7a of the elastic member 7 is above the concrete upper surface height level 120. Therefore, the elastic member 7 of the position indicator 1 is installed in an upright position that protrudes above the concrete upper surface height level 120.

[0057] Figure 12 shows the state after concrete 130 has been poured onto the upper surface of the deck plate 100. When the concrete 130 has been poured up to the upper surface height level 120, the elastic member 7 of the position indicator 1 protrudes from the upper surface 131 of the concrete 130, as shown in Figure 12(a). This elastic member 7 indicates the position where the sleeve 150 is embedded. Also, the concrete 130 does not enter the hollow space 152 inside the sleeve 150.

[0058] Once the concrete 130 is poured, a concrete floor finishing device is used to level the top surface 131 of the concrete 130. At this time, the elastic member 7 changes from an upright position to a sideways position when it comes into contact with the rotary trowel 140, and returns from the sideways position to an upright position when the rotary trowel 140 passes over it, just as in the first embodiment. Therefore, the position indicator 1 of this embodiment also exhibits the same effects and functions as in the first embodiment.

[0059] Once the finishing work is complete and the concrete 130 has hardened, the position of the embedded sleeve 150 can be identified using the position of the elastic member 7 as a guide. Therefore, the worker can remove the cover 151 from the upper end of the sleeve 150 by striking and crushing the thin-walled portion of the concrete 130 surrounding the elastic member 7 with a hammer or similar tool. As a result, vertical through-holes 160 are formed in the floor slab made of concrete 130, as shown in Figure 12(b), through the hollow space 152 inside the sleeve 150 and the holes 106 in the deck plate 100. Pipes and cables are placed between the upper and lower floors using these through-holes 160.

[0060] (Third embodiment) Next, a third embodiment of the present invention will be described. Figure 13 is a diagram showing an example of the configuration of the position indicator 1 in this embodiment. Figure 13(a) shows a perspective view of the position indicator 1, and Figure 13(b) shows a cross-sectional view of the position indicator 1. The position indicator member 6 of this position indicator 1 is composed of a brush member 9. The brush member 9 holds a large number of brush bristles 10 in an upright position. The brush bristles 10 are made of resin, for example, and each of them is elastic. The brush member 9 has a mounting portion 11 at its lower part that is attached to the tip of the shaft portion 3, and the brush bristles 10 are planted on the upper surface of the mounting portion 11. For example, the brush member 9 forms a hollow space 8 in the center by planting the brush bristles 10 on the peripheral edge of the mounting portion 11, except for the center of the mounting portion 11.

[0061] In other words, the position indicator 1 of this embodiment uses a brush member 9 as the position indicator 6 instead of the elastic member 7 of the first or second embodiment. Because each individual brush bristle 10 of the brush member 9 is elastic, when the rotary trowel 140 strikes it during concrete finishing work, the brush member 9 changes its posture from an upright position to a sideways position. At this time, each individual brush bristle 10 takes on a sideways position in an independent direction. As a result, the tips of the multiple brush bristles 10 spread out, and the brush member 9 takes on a sideways position with many brush bristles 10 bent in a fan shape. Furthermore, there are no brush bristles 10 in the central part of the brush member 9, forming a hollow space 8. Therefore, when many brush bristles 10 take on a sideways position, the entire structure deforms flat, allowing the entire brush bristles 10 to be embedded in the concrete. When the rotary trowel 140 passes over it, the many brush bristles 10 return to their original upright position due to the restoring force based on their elasticity.

[0062] Furthermore, even if concrete adheres to each individual brush bristle 10 after the finishing work, the concrete attached to the brush bristles 10 can be easily removed by simply brushing them off. Therefore, if the brush bristles 10 of the brush member 9 are colored according to the diameter or type of the through-hole, the color can be easily confirmed with a simple operation after the finishing work. Accordingly, the position indicator 1 of this embodiment exhibits the same effects and advantages as the first embodiment.

[0063] Furthermore, the position indicator 1 of this embodiment may be configured in the same way as the configuration described in the first or second embodiment, except for the points mentioned above.

[0064] (modified version) Several preferred embodiments of the present invention have been described above. However, the present invention is not limited to those described in the above embodiments. That is, the present invention includes various modifications to those described in the above embodiments.

[0065] For example, in the above embodiment, the case in which the deck plate 100 is a corrugated steel plate having valleys 101 and peaks 102 was described. However, the deck plate 100 on which the position indicator 1 is installed is not necessarily limited to being made of corrugated steel plate.

[0066] Furthermore, in the above embodiment, a deck plate 100 was described as an example of formwork into which concrete is poured. However, in the present invention, the formwork into which concrete is poured is not limited to a deck plate. That is, the formwork may be made of other plate materials such as concrete panels, wooden frames, or resin frames.

[0067] Furthermore, in the above embodiment, the position indicator member 6 is colored, and an example was described in which the diameter and type of the through hole are indicated by the color. However, the means of indicating the diameter and type of the through hole are not necessarily limited to color. For example, the diameter and type of the through hole may be indicated by letters or symbols on the side surface of the position indicator member 6. Alternatively, the diameter and type of the through hole may be indicated by changing the shape of the tip of the position indicator member 6 according to the diameter and type of the through hole. Moreover, the part that is shaped according to the diameter and type of the through hole is not necessarily limited to the tip of the position indicator member 6. For example, a hole with a shape that indicates the diameter and type of the through hole may be formed on the side surface of the position indicator member 6 (specifically the elastic member 7).

[0068] Furthermore, in the third embodiment described above, a configuration in which the brush member 9 does not have brush bristles 10 in its central portion was illustrated. However, when the brush member 9 is used as a position indicator member 6, it is acceptable for brush bristles 10 to be implanted in the central portion of the brush member 9. This is because the brush member 9 assumes a lateral position by bending each individual brush bristle 10 in an independent direction, and if bristles are implanted in the central portion, the fan-shaped area becomes larger, resulting in a lateral position. Therefore, the fact that numerous brush bristles 10 deform flat as a whole remains unchanged, and the entirety of the brush bristles 10 can be embedded in the concrete. However, if it is necessary to increase the flattening ratio when the brush member 9 assumes a lateral position, it is preferable to form a hollow space 8 in the central portion of the brush member 9 where brush bristles 10 are not implanted, as described in the third embodiment.

[0069] Furthermore, in the above embodiment, an example was described in which the concrete floor finishing device has multiple rotary trowels arranged radially. However, the concrete floor finishing device may also be a device that smooths the top surface of concrete by rotating a single rotary trowel. In this case, the rotary trowel may be disc-shaped. [Explanation of symbols]

[0070] 1...Position indicator (position indicator for forming through holes), 2...Base, 3...Shaft, 4...First shaft, 5...Second shaft, 6...Position indicator member, 7...Elastic member, 9...Brush member, 100...Deck plate (formwork), 130...Concrete, 140...Rotating trowel, 150...Sleeve, 151...Lid. ?

Claims

1. A through-hole formation position indicator that is installed on the upper surface of the formwork before concrete is poured and indicates the position of the through-hole after concrete is poured, A base installed at the location where the through hole is formed, A shaft portion protruding upward from the base, A position indicator member is attached to the shaft portion and protrudes in an upright position from the top surface of the concrete after concrete is poured, Equipped with, The position indicator member is characterized in that, when finishing work is performed on the concrete floor surface after concrete has been poured, it changes its posture from an upright position to a sideways position due to the stress received from the rotary trowel, allows the rotary trowel to pass over the sideways position, and returns from the sideways position to the upright position after the rotary trowel has passed.

2. The position indicator for forming a through hole according to claim 1, characterized in that the position indicator member is made of a hollow tubular elastic member.

3. The through-hole formation position indicator according to claim 2, characterized in that the elastic member is colored with a color corresponding to the diameter or type of the through-hole.

4. The position indicator for forming a through hole according to claim 1, characterized in that the position indicator member is composed of a brush member having a large number of brush bristles.

5. The through-hole forming position indicator according to claim 4, characterized in that the brush bristles are colored according to the diameter or type of the through-hole.

6. The shaft portion is characterized in that it is extendable and retractable according to the height level of the upper surface of the concrete, as described in any one of claims 1 to 5.

7. The position indicator for forming through holes according to any one of claims 1 to 5, characterized in that the lower surface of the base is fixed to the upper surface of the formwork.

8. A sleeve is installed on the formwork at the location where the through hole is formed, and a cover is provided at the upper end of the sleeve. The position indicator for forming a through hole according to any one of claims 1 to 5, characterized in that the lower surface of the base is fixed to the upper surface of the lid.

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