Jig and hole forming method

Abstract

To provide a jig and a hole forming method for making it easier to form a second hole in a second wall adjacent to a first wall, the second hole being communicating with a first hole provided in the first wall.SOLUTION: A jig of the present invention is used for forming an outer hole H2 in a second wall W2 adjacent to a first wall W1, the outer hole H2 being communicating with an inner hole H1 provided in the first wall W1, and includes: an outer peripheral part 12 capable of engaging with an inner peripheral surface of the inner hole H1; a cylindrical part 14 that is disposed inside the outer peripheral part 12 and has a central axis coinciding with a central axis of the outer peripheral part 12; and a connecting part 16 for connecting the outer peripheral part 12 and the cylindrical part 14.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a jig and a hole forming method, and more particularly to a jig used for forming a second hole in a second wall adjacent to the first wall, the second hole communicating with a first hole provided in the first wall, and a hole forming method using the jig. [Background technology]

[0002] It is already known to provide through holes in the exterior walls of buildings for drainage, ventilation, etc. For example, in Patent Document 1, a through hole is formed in a parapet erected around the upper surface of a flat roof of a building, and a drainage pipe (more specifically, a pipe for carrying overflow water from a drainage ditch) is inserted into the hole. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2010-043410 A Summary of the Invention [Problem to be solved by the invention]

[0004] For example, in an exterior wall constructed by stacking multiple walls, when a through hole has already been formed in one of the multiple walls (hereinafter, the first wall) and a hole is to be formed in the remaining wall (hereinafter, the second wall) so as to communicate with this hole, it is necessary to know the center position of the existing hole. For this reason, it is common to actually measure the center position (core) of the existing hole using a scale or the like and identify the corresponding position of the measured core on the second wall, which is a so-called centering operation, but the centering operation requires high accuracy. On the other hand, the centering operation is required to be easy to perform and to be completed in as short a time as possible.

[0005] Therefore, the present invention has been made in consideration of the above-mentioned problems, and its object is to make it easier to form a second hole in a second wall adjacent to the first wall, the second hole communicating with a first hole in a first wall, and specifically, to provide a jig and a hole forming method for achieving this. [Means for solving the problem]

[0006] The above-mentioned problems are solved by the jig of the present invention, which is a jig used for forming a second hole in a second wall adjacent to the first wall, the second hole communicating with a first hole provided in a first wall, and which has an outer peripheral portion capable of fitting into the inner surface of the first hole, a tubular portion disposed inside the outer peripheral portion and having a central axis coinciding with the central axis of the outer peripheral portion, and a connecting portion connecting the outer peripheral portion and the tubular portion. By using the jig of the present invention configured as described above, the centering of the first hole provided in the first wall can be accurately and simply performed, and as a result, the second hole communicating with the first hole can be easily formed in the second wall adjacent to the first wall.

[0007] In the above jig, it is preferable that the outer circumferential portion is constituted by two or more arc-shaped portions spaced apart from each other, and the connecting portion connects each of the arc-shaped portions to the cylindrical portion. According to the above configuration, the structure of the outer periphery can be made easy to install and lightweight.

[0008] Furthermore, in the above jig, it is more preferable that the threads formed on the outer peripheral surface of the outer peripheral portion engage with the threads formed on the inner peripheral surface of the first hole. According to the above configuration, the state in which the jig is placed in the first hole can be stably maintained.

[0009] In the above jig, it is more preferable that the first hole and the second hole are each a circular hole, and the tubular portion has a cylindrical insertion hole. According to the above configuration, it becomes easier to specify the center position of the first hole using the jig, that is, to perform the centering operation.

[0010] It is even more preferable that the jig is made of metal. According to the above-mentioned configuration, the durability of the jig is improved and cleaning of the jig is also facilitated.

[0011] In the above jig, it is even more preferable that the cylindrical portion is longer than the outer circumferential portion in the direction in which the central axis of the cylindrical portion and the central axis of the outer circumferential portion extend. According to the above configuration, the jig becomes easy to handle, specifically, easy to carry.

[0012] Furthermore, in the above-mentioned jig, when one of two opposite directions in which the central axis of the tubular portion and the central axis of the outer peripheral portion extend is set as the predetermined direction, it is even more preferable that the tubular portion protrudes in the predetermined direction from the end of the outer peripheral portion located on the predetermined direction side. According to the above-mentioned configuration, the jig can be more easily handled, and an insert (for example, a cone-shaped body, which will be described later) can be easily inserted into the cylindrical portion.

[0013] Furthermore, the above-mentioned problem is solved by the hole forming method of the present invention, which is a hole forming method for forming a second hole in a second wall adjacent to the first wall, the second hole communicating with a first hole provided in the first wall, by inserting the above-mentioned jig into the first hole, fitting the outer peripheral portion to the inner peripheral surface of the first hole, and abutting the tip of a rod body inserted inside the tubular portion against the second wall to identify the center position of the first hole, and forming the second hole in the second wall based on the identified center position of the first hole. According to the above method, the second hole communicating with the first hole provided in the first wall can be more easily formed in the second wall adjacent to the first wall. Effect of the Invention

[0014] According to the present invention, it is possible to more easily perform the task of forming a second hole in a second wall adjacent to the first wall, the second hole communicating with a first hole provided in the first wall. [Brief description of the drawings]

[0015] [Figure 1] 4 is a side cross-sectional view of a first wall and a second wall in which holes communicating with each other are formed. FIG. [Diagram 2] FIG. 1 is a perspective view of a jig according to one embodiment of the present invention. [Diagram 3] FIG. 2 is a front view of a jig according to one embodiment of the present invention. [Figure 4] FIG. 2 is a side view of a jig according to one embodiment of the present invention. [Diagram 5] FIG. 1 is a diagram showing a state of a hole forming operation according to one embodiment of the present invention (part 1). [Figure 6] FIG. 2 is a diagram showing a hole forming operation according to one embodiment of the present invention (part 2). [Figure 7] FIG. 11 is a diagram showing a state of a hole forming operation according to one embodiment of the present invention (part 3). [Figure 8] FIG. 4 is a diagram showing a hole forming operation according to one embodiment of the present invention (part 4). DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0016] <<About one embodiment of the present invention>> Hereinafter, one embodiment of the present invention (hereinafter, this embodiment) will be described with reference to the accompanying drawings 1 to 8. In the drawings, each component is shown somewhat simplified and schematic to make the explanation easier to understand, and the size (dimension) of each component and the interval between components shown in the drawings are different from the actual ones.

[0017] In addition, in this specification, "orthogonal," "vertical," "parallel," and "horizontal" include the range of error generally accepted in the technical field of the present invention, and also include states where the directions are shifted by less than a few degrees (e.g., 2 to 3°) from the strict directions of orthogonal, vertical, parallel, and horizontal. Furthermore, in this specification, the terms "same," "identical," "equal," "match," and "matched" are not limited to their strict meanings, but may be interpreted as including cases where they differ within the range of error generally accepted in the technical field to which this invention pertains.

[0018] [Outline of hole formation work] In describing this embodiment, a hole forming operation performed using a jig and a hole forming method according to this embodiment will be described with reference to FIG. The hole forming work according to this embodiment is, for example, work of forming a hole in an exterior wall (hereinafter, exterior wall W) that constitutes the roof part of a building.

[0019] As shown in Fig. 1, the exterior wall W is a double-wall structure having a first wall W1 and a second wall W2 that is disposed outside the first wall W1 and adjacent to the first wall W1. The first wall W1 is a wall that rises from the peripheral portion of the upper surface of the flat roof of the building, specifically a parapet, and in this embodiment, is made of RC (Reinforced Concrete). The second wall W2 is a wall that is disposed parallel to the first wall W1 with a slight gap therebetween, and functions as a finishing material for the exterior wall, and in this embodiment, is made of ALC (Autoclaved Lightweight Aerated Concrete). The distance between the first wall W1 and the second wall W2 is about 100 mm to 300 mm.

[0020] Further, the first wall W1 and the second wall W2 each have a circular hole as a through hole. The circular hole formed in the first wall W1 (hereinafter, inner hole H1) corresponds to the first hole, and as shown in FIG. 1, is continuous with a drain groove R formed inside the first wall W1 at a location adjacent to the first wall W1 in the flat roof. The circular hole formed in the second wall W2 (hereinafter, outer hole H2) corresponds to the second hole. As shown in FIG. 1, a common drain pipe P is inserted (strictly speaking, fitted) into both the inner hole H1 and the outer hole H2, and the drain pipe P is connected to a downspout T.

[0021] In other words, the inner hole H1 and the outer hole H2 are holes provided to drain water on the roof, and are connected to each other via a drain pipe P. The inner hole H1 and the outer hole H2 have the same diameter, and their central axes are in a continuous positional relationship. "The central axes are continuous" means that if the central axis of the inner hole H1 is virtually extended, the extended central axis of the inner hole H1 and the central axis of the outer hole H2 will coincide. In this embodiment, the central axes of the inner hole H1 and the outer hole H2 extend horizontally, more specifically, in a direction perpendicular to the first wall W1 and the second wall W2 (in other words, parallel to the thickness direction of each wall).

[0022] In this embodiment, the inner hole H1 is formed simultaneously with the first wall W1 when the first wall W1 is constructed. To explain in more detail, when constructing the first wall W1, a roof drain pipe is placed at the formation position of the inner hole H1, and when the concrete constituting the first wall W1 is poured, the roof drain pipe is embedded in the first wall W1. The inner hole H1 is formed by the roof drain pipe thus embedded, and the inner wall surface of the pipe constitutes the inner circumferential surface of the inner hole H1. Note that a screw thread Hc is formed on the inner wall surface of the roof drain pipe (see FIG. 5).

[0023] On the other hand, the outer hole H2 is formed by using a tool such as a hole saw S (see FIG. 8) after the second wall W2, in which no through hole has been formed yet, is placed adjacent to the first wall W1. When forming the outer hole H2, a centering operation is performed in which the center position (core) of the inner hole H1 is identified and the identified core is identified on the second wall W2 side. The centering operation determines the center position of the outer hole H2, and more specifically, the center axes of the inner hole H1 and the outer hole H2 are determined so as to be continuous with each other. Then, the center of the hole saw S is aligned with the determined center position (core) of the outer hole H2, and the outer hole H2 is formed (bored) in the second wall W2 by the hole saw S. At this time, the hole saw S is brought into contact with the outer surface of the second wall W2 (the surface opposite to the side where the first wall W1 is located) to form the outer hole H2 from the outer surface of the second wall W2.

[0024] [Example of jig configuration] Next, a configuration example of the jig 10 according to this embodiment will be described with reference to Figures 2 to 4. In the following, when describing the position, orientation, state, etc. of each part of the jig 10, unless otherwise specified, the position, orientation, state, etc. of the jig 10 will be described when the jig 10 is in use, specifically, when the jig 10 is placed in the inner hole H1 during a hole forming operation. In the following description, the clockwise direction is defined as the positive direction, and three points lined up in the positive direction are designated A, B, and C. With point A as the reference, the side closer to point A in the positive direction is referred to as the "upstream side," and the side farther away from point A is referred to as the "downstream side." In other words, as viewed from point A, point B is a point located further upstream, and point C is a point located further downstream.

[0025] The jig 10 is used to form the outer hole H2 in the second wall W2, and more specifically, is a tool used in a centering operation. The jig 10 has an outer shape shown in Figs. 2 to 4, and as shown in these figures, has an outer peripheral portion 12, a cylindrical portion 14, and a connecting portion 16. In this embodiment, each portion of the jig 10 is made of a metal such as steel or an alloy. However, this is not limited thereto, and for example, each portion of the jig 10 may be made of a non-metallic material, such as a resin material. From the viewpoints of durability and ease of cleaning, it is preferable that the jig 10 is made of a metal.

[0026] The outer peripheral portion 12 forms an outer end portion in the radial direction of the jig 10, and can be fitted to the inner peripheral surface of the inner hole H1 when the jig 10 is in use. In this embodiment, the outer peripheral portion 12 is composed of two arc-shaped portions 12a, 12b spaced apart from each other, as shown in Figs. 2 and 3. Each of the two arc-shaped portions 12a, 12b is a portion having an outer peripheral surface curved in an arc shape, and in this embodiment, they are arranged at positions 180 degrees apart from each other with the cylindrical portion 14 as the center. Note that the number of arc-shaped portions constituting the outer peripheral portion 12 is not limited to two, and may be three or more.

[0027] The two arc-shaped portions 12a, 12b are each made of a steel plate bent into an arc shape, and are made, for example, by cutting a short cylindrical member into an arc shape. The central angle of the arc formed by the outer peripheral surface of each arc-shaped portion 12a, 12b is 30 to 180 degrees, and preferably about 60 to 100 degrees. The central positions of the arcs formed by the outer peripheral surfaces of each arc-shaped portion 12a, 12b are aligned between the two arc-shaped portions 12a, 12b. The central positions of each arc-shaped portion 12a, 12b correspond to the position of the central axis of the outer peripheral portion 12 (more specifically, the position through which the central axis passes).

[0028] In this embodiment, the two arcuate portions 12a and 12b are provided at the same position in the central axis direction. Here, the central axis direction is the direction in which the central axis of the cylindrical portion 14 extends. As described later, the central axis of the cylindrical portion 14 coincides with the central axis of the outer peripheral portion 12, so the central axis direction can also be said to be the direction in which the central axis of the outer peripheral portion 12 extends.

[0029] As shown in Fig. 4, a plurality of threads 12c are formed on the outer peripheral surface of each of the arc-shaped portions 12a, 12b along the central axis direction. The threads 12c can be engaged with threads Hc (see Fig. 5) formed on the inner peripheral surface of the inner hole H1. The threads 12c formed on the outer peripheral surface of the outer peripheral portion 12 and the threads Hc formed on the inner peripheral surface of the inner hole H1 are engaged with each other, so that the outer peripheral portion 12 can be fitted (screwed) into the inner peripheral surface of the inner hole H1.

[0030] The cylindrical portion 14 is a member having a cylindrical shape and having a cylindrical insertion hole therein. The cylindrical portion 14 extends long along its central axis, and in this embodiment, is configured by a long nut. As can be seen from Figs. 2 and 3, the cylindrical portion 14 is disposed inside the outer peripheral portion 12 (inside in the radial direction of the cylindrical portion 14), and has a central axis that coincides with the central axis of the outer peripheral portion 12. Here, the central axis of the cylindrical portion 14 coinciding with the central axis of the outer peripheral portion 12 means that the position of the central axis of the cylindrical portion 14 is the same as the position of the central axis of the outer peripheral portion 12. In other words, the outer peripheral portion 12 (specifically, the arc formed by the outer peripheral surfaces of the arc-shaped portions 12a and 12b) and the cylindrical portion 14 share a central axis.

[0031] 2 and 4, the tubular portion 14 is longer in the central axis direction than the outer circumferential portion 12. When one of two mutually opposite directions in the central axis direction is defined as a predetermined direction, the tubular portion 14 protrudes in the predetermined direction longer than the end of the outer circumferential portion 12 located on the predetermined direction side. The predetermined direction is the direction from the end of the tubular portion 14 on the side where the outer circumferential portion 12 is provided in the central axis direction (hereinafter referred to as the base end) toward the opposite end (hereinafter referred to as the tip end). In other words, the cylindrical portion 14 formed by the long nut protrudes outward in the central axial direction beyond the outer periphery portion 12. As a result, when transporting the jig 10, the jig 10 can be easily held by gripping the portion of the cylindrical portion 14 that protrudes outward beyond the outer periphery portion 12. This configuration makes the jig 10 easier to handle (easy to carry). In addition, the cylindrical portion 14 is not limited to being constituted by a prefabricated long nut, but may be any long cylindrical body, and does not have to have a screw thread formed on the inner peripheral wall like a long nut.

[0032] The connecting portion 16 is a portion that connects the outer circumferential portion 12 and the cylindrical portion 14, and more specifically, as shown in Figures 2 and 3, connects each of the two arcuate portions 12a, 12b to the cylindrical portion 14. In this embodiment, the connecting portion 16 is configured by plate bodies 16a, 16b (connecting ribs) having one end joined to the inner circumferential surface of each of the arcuate portions 12a, 12b and the other end joined to the outer circumferential surface of the cylindrical portion 14. However, the connecting portion 16 may be configured by a rod body instead of a plate body.

[0033] In this embodiment, as shown in Figures 2 and 3, two plates 16a, 16b are joined to each of the arc-shaped portions 12a, 12b. Of the two plates 16a, 16b, one plate 16a is joined to the upstream end region of the inner circumferential surface of the arc-shaped portions 12a, 12b. The other plate 16b is joined to the downstream end region. Here, the "upstream side" and "downstream side" refer to the upstream side and downstream side when the clockwise direction is defined as the positive direction when the jig 10 is viewed from the tip side of the cylindrical portion 14 in the central axis direction.

[0034] 3, the plate body 16a joined to the upstream end region of one arcuate portion 12a and the plate body 16a joined to the upstream end region of the other arcuate portion 12b are arranged in a straight line across the cylindrical portion 14. Similarly, the plate body 16b joined to the downstream end region of one arcuate portion 12a and the plate body 16b joined to the downstream end region of the other arcuate portion 12b are arranged in a straight line across the cylindrical portion 14. That is, as shown in FIG. 3, the set of plate bodies 16a joined to the upstream end region and the set of plate bodies 16b joined to the downstream end region are arranged to form an X shape.

[0035] [Hole formation method using a jig] Next, a method for forming an outer hole H2 in the second wall W2, which communicates with the inner hole H1 in the first wall W1, using the above-mentioned jig 10 will be described with reference to Figures 5 to 8. Figures 5 to 8 are diagrams showing the state of a hole forming operation using the jig 10, and the operation progresses in the order of Figures 5, 6, 7, and 8.

[0036] To start the hole forming operation, the first wall W1 in which the inner hole H1 is formed is constructed, and the second wall W2 is disposed adjacent to the first wall W1. In the hole forming operation, first, the jig 10 is disposed in the inner hole H1 as shown in Fig. 5. Specifically, the jig 10 is inserted into the inner hole H1 from the base end side of the cylindrical portion 14, and more specifically, the jig 10 is inserted into the roof drain pipe that constitutes the inner hole H1.

[0037] At this time, a person engaged in the hole forming operation (hereinafter, the worker) grasps the tip of the cylindrical portion 14 and positions the jig 10 so that the outer peripheral surface of the outer peripheral portion 12, more specifically, the outer peripheral surfaces of the arcuate portions 12a and 12b, are aligned with the inner peripheral surface of the inner hole H1. While maintaining this state, the worker rotates the jig 10 around the cylindrical portion 14 that he is holding. As a result, the thread 12c formed on the outer peripheral surface of the outer peripheral portion 12 and the thread Hc formed on the inner peripheral surface of the inner hole H1 mesh with each other, and the outer peripheral portion 12 fits (screws) into the inner peripheral surface of the inner hole H1. As can be seen from FIGS. 1 and 5, the thread Hc is not formed in the region of the inner end (the end located opposite to the second wall W2) on the inner peripheral surface of the inner hole H1, and the thread Hc is formed in the region on the back side of that region. Therefore, in order to mesh the thread 12c of the outer peripheral portion 12 of the jig 10 with the thread Hc, the jig 10 is inserted into the inner hole H1 while being slightly tilted. Then, the outer peripheral portion 12 is inserted into the inner hole H1 until it reaches the region of the inner peripheral surface of the inner hole H1 where the thread Hc is formed. Here, since the outer peripheral portion 12 is composed of two arc-shaped portions 12a and 12b that are spaced apart from each other, when the jig 10 is inserted into the inner hole H1 while being tilted, the outer peripheral portion 12 is easily inserted into the back side of the inner hole H1, and the outer peripheral portion 12 can be smoothly moved to the position where the threads mesh with each other.

[0038] When the worker further rotates the jig 10 with the outer circumferential portion 12 fitted to the inner circumferential surface of the inner hole H1, the jig 10 gradually enters the inner side of the inner hole H1, and eventually the jig 10 reaches a position where most of the jig 10 is inside the inner hole H1. At this stage, the position of the central axis of the tubular portion 14 of the jig 10 coincides with the center position (i.e., the core) of the inner hole H1. At this time, it is preferable that the tip of the tubular portion 14 is inside the inner opening of the inner hole H1 (the opening located on the opposite side to the second wall W2), that is, it protrudes somewhat toward the worker.

[0039] Next, the worker attaches a cone-shaped rod body Da (bit) to the attachment port of an electric screwdriver D (specifically, an impact driver or a drill driver), and inserts the rod body Da into the inside of the cylindrical part 14 of the jig 10 from the tip side of the cylindrical part 14, as shown in Fig. 6. The diameter of the rod body Da is slightly smaller than the inner diameter of the cylindrical part 14, and the rod body Da is inserted into the cylindrical part 14 with almost no play between the rod body Da and the inner peripheral surface of the cylindrical part 14.

[0040] After the tip of the rod body Da protrudes from the base end of the cylindrical part 14 to the outside, as shown in FIG. 7, it abuts against the surface of the second wall W2 on the side facing the first wall W1. In this state, the operator operates the electric screwdriver D. As a result, the rod body Da abutting against the second wall W2 bites into the second wall W2 while rotating, and finally penetrates the second wall W2. The through hole (hereinafter, the mark hole M) formed at this time is located on an extension line of the central axis of the cylindrical part 14, in other words, reflects the center position of the inner hole H1. In other words, the mark hole M as a through hole is drilled in the second wall W2 by the rod body Da, and this mark hole M becomes a pilot hole, and the center position of the inner hole H1 is specified on the second wall W2 side, that is, centering for forming the outer hole H2 is performed.

[0041] Thereafter, the worker forms the outer hole H2 in the second wall W2 based on the center position of the inner hole H1 identified in the second wall W2, i.e., the mark hole M. Specifically, as shown in FIG. 8, with the center of the hole saw S aligned with the mark hole M, the hole saw S is rotated while being pressed against the outer surface of the second wall W2 (the surface opposite the first wall W1). This cuts the inner portion of the hole saw S in the second wall W2, and as a result, the outer hole H2, which is a circular hole, is formed in the second wall W2. The center axis of the formed outer hole H2 is continuous with the center axis of the inner hole H1.

[0042] After the outer hole H2 is formed, the worker inserts a single drain pipe P into both the inner hole H1 and the outer hole H2. At this time, since the central axes of the inner hole H1 and the outer hole H2 are continuous, the drain pipe P can be smoothly inserted into each hole. In addition, the position of the central axis of the drain pipe P can be aligned with the position of the central axis of the inner hole H1 and the outer hole H2, so that the drain pipe P can be properly inserted.

[0043] In other words, if the central axes of the inner hole H1 and the outer hole H2 are misaligned, the drain pipe P cannot be smoothly inserted, and the outer hole H2 may have to be re-drilled. In contrast, in this embodiment, the outer hole H2 can be formed so that the central axes of the inner hole H1 and the outer hole H2 are continuous, so that the above-mentioned problems can be avoided. This effect is particularly effective when the central position (core) of the inner hole H1 formed in the first wall W1 located inside the second wall W2 is specified in the second wall W2, and then the outer hole H2 is formed from the outside of the second wall W2 (the opposite side to the first wall W1). Furthermore, when a gap, specifically a gap of about 100 mm to 300 mm, is provided between the first wall W1 and the second wall W2, the above-mentioned effect becomes even more significant.

[0044] Furthermore, since there is usually a gap between the inner peripheral surface of each of the inner hole H1 and the outer hole H2 and the outer peripheral surface of the drain pipe P, the worker fills the gap with caulking material after inserting the drain pipe P to seal the gap. Here, since the drain pipe P is inserted into each hole with the position of its central axis coinciding with the position of the central axis of each of the inner hole H1 and the outer hole H2, the size (spacing) of the above-mentioned gap is uniform over the entire circumference of the drain pipe P. Thus, according to this embodiment, the gap is filled with caulking material appropriately and in a good-looking manner.

[0045] According to the procedure described above, in this embodiment, the centering of the inner hole H1 can be performed accurately and easily by using the jig 10. This makes it possible to easily form the outer hole H2 communicating with the inner hole H1 in the second wall W2.

[0046] <<Other embodiments>> Although one embodiment of the jig and hole forming method of the present invention has been described above, the above embodiment is merely an example for facilitating understanding of the present invention and does not limit the present invention. In other words, the present invention may be modified or improved without departing from the spirit of the present invention. In addition, the present invention naturally includes its equivalents.

[0047] In the above embodiment, the central axes of the inner hole H1 and the outer hole H2 extend horizontally. However, this is not limited to this, and the central axis of the inner hole H1 may be slightly inclined relative to the horizontal direction from the viewpoint of improving drainage performance. In this case, it is preferable to form the outer hole H2 in the second wall W2 taking into consideration the inclination of the central axis of the inner hole H1.

[0048] In the above embodiment, the holes provided in the first wall W1 and the second wall W2 are holes for drainage (more specifically, holes for inserting a drainage pipe), but the present invention is not limited to this. The present invention is also applicable to a case where a hole for a purpose other than drainage, for example, a hole for ventilation (air passage), is provided in each of the first wall and the second wall adjacent to each other.

[0049] In the above embodiment, the number of walls (first wall W1 and second wall W2) constituting the outer wall is two, but the number of walls constituting the outer wall may be three or more. In that case, the jig and hole forming method of the present invention can be used when forming a hole in the remaining wall (second wall W2) that communicates with a hole (first hole) formed in one wall (first wall W1). [Explanation of symbols]

[0050] 10 Jig 12 Outer periphery 12a, 12b Arc-shaped portion 12c thread 14 Cylindrical part 16 Connecting part 16a,16b plate D Electric screwdriver Da rod H1 Inner hole (first hole) H2 Outer hole (second hole) Hc thread M Marking hole P Drain pipe R Drain T-pipe S Hole Saw W Exterior wall W1 1st wall W2 Second Wall

Claims

1. A jig used for forming a second hole in a second wall adjacent to a first wall, the second hole communicating with a first hole provided in the first wall, the jig comprising: an outer circumferential portion that can be fitted into an inner circumferential surface of the first hole; a cylindrical portion disposed inside the outer circumferential portion and having a central axis coinciding with a central axis of the outer circumferential portion; A jig having a connecting portion that connects the outer circumferential portion and the tubular portion.

2. The outer periphery is formed of two or more arcuate portions spaced apart from each other, The jig according to claim 1 , wherein the connecting portions connect each of the arc-shaped portions to the cylindrical portion.

3. The jig described in claim 1 , wherein a thread formed on an outer peripheral surface of the outer peripheral portion engages with a thread formed on an inner peripheral surface of the first hole, so that the outer peripheral portion fits into the inner peripheral surface of the first hole.

4. the first hole and the second hole are each a circular hole, The jig according to claim 1 , wherein the cylindrical portion has a cylindrical insertion hole.

5. The jig according to claim 1 , wherein the jig is made of metal.

6. The jig according to claim 1 , wherein the cylindrical portion is longer than the outer circumferential portion in a direction in which a central axis of the cylindrical portion and a central axis of the outer circumferential portion extend.

7. 2. The jig described in claim 1, wherein when one of two opposite directions in the direction in which the central axis of the tubular portion and the central axis of the outer circumferential portion extend is defined as a predetermined direction, the tubular portion protrudes in the predetermined direction from the end of the outer circumferential portion that is located on the predetermined direction side.

8. A hole forming method for forming a second hole in a second wall adjacent to a first wall, the second hole being in communication with a first hole provided in the first wall, the method comprising the steps of: Inserting the jig according to any one of claims 1 to 7 into the first hole; The outer circumferential portion is fitted into an inner circumferential surface of the first hole; abutting a tip of a rod inserted into the cylindrical portion against the second wall to identify a center position of the first hole; a hole forming method for forming the second hole in the second wall based on the identified center position of the first hole.

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