JP2020082229A - Hole drilling jig and hole drilling method for steel pipe - Google Patents

Abstract

To provide a hole drilling jig and a hole drilling method for a steel pipe, which enable a bolt hole to be drilled in a side surface of the cylindrical cross-section steel pipe with a high degree of accuracy.SOLUTION: A hole drilling jig 20 for a steel pipe, which is used to drill a bolt hole 30A in a side surface of the cylindrical steel pipe 30, includes a body 21 that is arranged on the side surface of the steel pipe 30 and that has one or more openings 21A provided in positions to face a surface of the steel pipe 30, and fixing structures 22-25 for fixing the body 21 to the side surface of the steel pipe 30.SELECTED DRAWING: Figure 2

Description

TECHNICAL FIELD The present invention relates to a jig for punching a steel pipe and a method for punching the steel pipe. More specifically, for example, a steel pipe capable of correctly forming a bolt hole for fastening a member with a bolt on a side surface of a cylindrical steel pipe. The present invention relates to a hole making jig and a hole making method.

Tower cranes are used at construction sites to drive in trucks for material transportation and to suspend and transport various building materials. The pedestal of the mast of the tower crane is composed of girder materials such as H-section steel (“lining girders” and “horizontal joint materials”), and the girder materials are rotary press-fit steel pipes that have penetrated into the ground. It is supported and fixed to a support pile such as a pile (see Patent Document 1 and the like).

For example, the rotary press-fit steel pipe pile 100 shown in FIG. 10 is a steel pipe pile in which blades 102 are attached to the tip side (lower end side) of a steel pipe 101 having a circular cross section, and can be used in a narrow place. It has the advantages that it can be gently screwed in, that it can be reliably driven into hard ground by the blade at the tip, and that no residual soil will be generated. Examples of such a rotary press-fitted steel pipe pile include "NS Ecopile" (registered trademark of Nippon Steel & Sumikin Engineering Co., Ltd.).

There is, for example, Patent Document 1 as an application of such a rotary press-fitted steel pipe pile having a circular cross section as a support pile. That is, the girder material (H-shaped steel) forming the pedestal is fixed to the rotary press-fitted steel pipe pile by using a connecting fitting. Then, in order to securely fix the girder material and the rotary press-fitted steel pipe pile, as shown in FIG. 11, the concave webs of the holding members 32, 32 constituting the connection fittings on the side surface on the upper end side of the rotary press-fitted steel pipe pile 100. Must be brought into contact with each other and fixed by the fixing bolts 2a to 2c. Then, as the work relating to the bolt hole drilling for the rotary press-fitted steel pipe pile 100, the target position where the bolt hole is to be formed on the side surface of the rotary press-fitted steel pipe pile buried in the ground is marked out, and then the target Push the cutting blade of the electric drill (drilling device) from the front toward the position and keep the posture of the electric drill until the bolt hole is drilled toward the center of the steel pipe pile with a circular cross section. It was

Patent No. 6355057 Japanese Patent No. 4077777

However, conventionally, there is a problem that the posture of the electric drill has to be unstable because the worker has had to perform a bolt hole drilling work in a middle waist state. If the posture of the electric drill is unstable, the bolt holes cannot be correctly drilled toward the center of the steel pipe pile that has a circular cross section.If the bolt holes are not drilled correctly, the holding member can also be installed correctly. Can not.

On the other hand, as an electric drill, for example, an electric drill device with an attachment base composed of an electromagnet as shown in Patent Document 2 is provided. Although it is thought that the burden on the operator is reduced by using the electric drill, it is necessary to magnetically attach the attachment base to a flat surface in order to perform the drilling work while the posture of the electric drill is stable. is there. However, since the side surface of the rotary press-fitted steel pipe pile is a curved surface, there is a problem that the electric drill cannot be stably fixed.

Therefore, as a result of intensive studies aimed at solving such a conventional problem, the present inventor has completed the present invention relating to a new jig and method for boring a steel pipe. That is, an object of the present invention is to provide a jig for punching a steel pipe and a method for punching a steel pipe, which are capable of highly accurately drilling bolt holes on the side surface of a steel pipe having a cylindrical cross section.

In order to solve the above-mentioned problems, the present invention according to claim 1 is a jig for drilling a steel pipe for forming a bolt hole in a side face of a cylindrical steel pipe, the main body being arranged on the side face of the steel pipe. And a main body having one or a plurality of openings provided at a position directly facing the surface of the steel pipe, and a fixing structure for fixing the main body to a side surface of the steel pipe. And

In order to solve the above-mentioned problems, the present invention according to claim 2 is the jig for drilling a steel pipe according to claim 1, wherein the main body has a flat plate shape and is erected on the left and right sides of the flat plate-like main body. It is characterized in that a pair of side plates are provided as at least a part of the fixing structure.

In order to solve the above-mentioned problems, the present invention according to claim 3 is the jig for drilling a steel pipe according to claim 2, wherein a pair of collar portions formed outside the left and right side plates is provided in the fixing structure. At least a part of the flange portions is provided with fixing bolt holes for attaching the fixing bolts, respectively.

In order to solve the above-mentioned problems, the present invention according to claim 4 is characterized in that, in the jig for punching a steel pipe according to claim 3, a plurality of the pair of flange portions are provided. And

In order to solve the above problems, the present invention according to claim 5 provides a bolt hole in the method for drilling using a jig for drilling a steel pipe according to any one of claims 1 to 4. The step of marking out a predetermined position on the side surface of the steel pipe to be disposed, and the first jig for punching the steel pipe and the second jig for punching the steel pipe are arranged at positions facing each other with the steel pipe sandwiched therebetween. And a step of aligning one or both of the first steel pipe hole forming jig and the second steel pipe hole forming jig so that the opening portion of the main body faces the predetermined position marked out. A step of fixing the first jig for punching the steel pipe and the second jig for punching the steel pipe by the fixing structure of each other; and Drilling a bolt hole with a drilling device through the opening.

In order to solve the above-mentioned problems, the present invention according to claim 6 relates to a hole forming method using the jig for forming a steel pipe according to claim 5, wherein the punching device is fixed to the main body by magnetic force. It is characterized in that a bolt hole is bored by.

In order to solve the above-mentioned problems, the present invention according to claim 7 provides a bolt hole in the method for drilling using a jig for drilling a steel pipe according to any one of claims 1 to 4. Indicating a predetermined position on the side surface of the steel pipe to be positioned, aligning the opening of the main body of the hole forming jig of the steel pipe so as to directly face the predetermined position that is marked out, and Fixing one side and the other side of the drilling jig by the fixing structure, and drilling a bolt hole by a drilling device through the opening of the main body with respect to the marked predetermined position. It is characterized by including and.

In order to solve the above problems, the present invention according to claim 8 is the drilling method according to any one of claims 5 to 7, characterized in that the steel pipe is a steel pipe pile.

According to the jig for punching a steel pipe according to the present invention, it is easy to fix the entire jig for punching a hole to the steel pipe by the fixing structure. When the bolt hole is formed on the side surface of the steel pipe by the drilling device through at least one opening, the opening can be used as a mark, and thus the accuracy of the drilling position of the bolt hole is improved. It's easy to do. Moreover, since the main body is interposed between the side surface of the steel pipe and the drilling device, and the main body is fixed to the steel pipe, it is possible to maintain the posture of the drilling device by supporting the main body during drilling. It is also easy to match the center line of the bolt hole with the normal line of the side surface. Therefore, the jig for drilling a steel pipe according to the present invention has an effect that it is possible to perform the drilling of the bolt hole with high accuracy on the side surface of the steel pipe having a cylindrical cross section.

According to the hole forming method using the hole forming jig for the steel pipe according to the present invention, the steel pipe is sandwiched from both sides by the first hole forming jig and the second hole forming jig, and the fixing structure is provided. It can be fixed to a steel pipe. When a bolt hole is drilled at a predetermined position of the steel pipe with the drilling device through at least one opening, the opening can be used as a mark, so that the accuracy of the drilled position of the bolt hole is high. Is easy to increase. Moreover, since the main body is interposed between the predetermined position of the steel pipe and the drilling device, and the main body is fixed to the steel pipe, a drilling device that can be magnetically attached by using the main body as a support during drilling is provided. It can be securely fixed, and the center line of the bolt hole can be easily matched with the normal line of the side surface. Therefore, according to the hole forming method using the jig for forming a steel pipe according to the present invention, there is an effect that the bolt hole can be formed with high accuracy on the side surface of the steel pipe having a cylindrical cross section. Moreover, according to the hole forming method using the hole forming jig for the steel pipe according to the present invention, the steel pipe is sandwiched from both sides by the first hole forming jig and the second hole forming jig having the same configuration. Therefore, there is also an advantage that it is easy to align the bolt holes at the positions symmetrical with respect to the center line of the steel pipe.

According to the punching method using the jig for punching a steel pipe according to the present invention, it is possible to fix the entire steel pipe to the steel pipe with the fixing structure such that the steel pipe is laterally held by the main body of the jig for punching. It is possible. Then, when a bolt hole is drilled at a predetermined position of the steel pipe with the drilling device through at least one opening, the opening can be used as a mark, so that the accuracy of the drilling position of the bolt hole can be improved. Easy to increase. Moreover, since the main body is interposed between the predetermined position of the steel pipe and the drilling device, and the main body is fixed to the steel pipe, a drilling device that can be magnetically attached by using the main body as a support during drilling is provided. By fixing, it becomes easy to make the center line of the bolt hole coincide with the normal line of the side surface. Therefore, according to the drilling method using the jig for drilling a steel pipe according to the present invention, there is an effect that the bolt hole can be drilled with high accuracy on the side surface of the steel pipe having a cylindrical cross section.

It is a perspective view showing a jig for punching according to the present embodiment. FIG. 2(A) is a perspective view showing a pair of hole drilling jigs attached to the steel pipe, and FIG. 2(B) is a perspective view showing the steel pipe after the bolt holes are drilled. FIG. 3 is a front view of the jig for punching in FIG. 2(A). FIG. 3 is a plan view of the jig for punching in FIG. 2(A). FIG. 3 is a side view of the hole forming jig in FIG. It is a perspective view showing the outline of an electric drill (drilling device). It is explanatory drawing explaining the drilling work by an electric drill (drilling device). It is a flow chart which shows the procedure of the punching method concerning this embodiment. It is a figure explaining the modification of the punching method. It is a perspective view which shows the structure of the principal part of a rotary press-fitting steel pipe pile. It is a top view which shows the attachment state of a rotation press fit steel pipe pile and a holding member.

First, a preferred embodiment of a hole making jig according to the present invention will be described with reference to the drawings.

[Structure of jig for punching]
First, the structure of the jig for punching according to the present embodiment will be described. FIG. 1 is a perspective view showing a hole making jig according to this embodiment, FIG. 2(A) is a perspective view showing a pair of hole making jigs mounted on a steel pipe, and FIG. It is a perspective view showing a steel pipe after perforation. 3 is a front view of the hole making jig shown in FIG. 2(A), FIG. 4 is a plan view of the hole making jig shown in FIG. 2(A), and FIG. 5 is a hole making jig shown in FIG. 2(A). FIG. The jig 20 for drilling in the present embodiment is a drilling tool for a steel pipe used for drilling bolt holes 30A, 30A on the side surface of a cylindrical steel pipe 30 such as a rotary press-fit steel pipe pile that is penetrated into the ground. It is a jig. In FIG. 2(A), the two jigs 20 for drilling are attached to the steel pipe 30 so as to face each other, and one jig 20 for punching and another jig for punching are drilled. The configuration of 20 is common.

The illustrated jig 20 for punching includes a main body 21 arranged on the side surface of the steel pipe 30, and fixing structures 22 to 25 for fixing the main body 21 to the side surface of the steel pipe 30. The main body 21 is a flat plate-shaped member made of a steel plate (iron plate or the like), and the fixing structures 22 to 25 are side plates 22 erected from the left and right (both edges) of the main body 21 so as to be bent in the same direction. , 23 and a pair of collar portions 24, 25 formed outside the left and right side plates 22, 23, respectively. The main body 21 is preferably formed of, for example, steel or iron to which an electric drill (drilling device) 50 described later can be magnetically fixed. Further, the side plates 22 and 23 and the collar portions 24 and 25 are made of the same material (steel, iron, etc.) as that of the main body 21.

The side plates 22 and 23 located on the left and right sides of the main body 21 may be formed by bending both ends of the steel plate forming the main body 21 in the same direction or by welding the flat side plates 22 and 23 to the edge portions of the main body 21. Therefore, it is integrally formed with the main body 21. In this case, the main body 21 including the side plates 22 and 23 has a substantially U-shaped cross section. Each of the collar portions 24 and 25 is also a member having a substantially U-shaped cross section, and both ends of a single steel plate are bent in the same direction, or flat plate members are combined into a substantially U-shaped cross section. It is formed by welding.

Further, in the main body 21, one or a plurality of side plates 22 and 23 are provided at positions facing the surface of the steel pipe 30 in a state where the left and right side plates 22 and 23 are in contact with the side surfaces of the steel pipe 30 (the state shown in FIG. 2A). 21A is provided. In this embodiment, three openings 21A, 21A, 21A are arranged in the center of the main body 21 at equal pitches along the height direction. These openings 21A, 21A, 21A are, for example, circular holes having a size capable of completely covering the bolt hole 30A (see FIG. 2B) to be formed on the side surface of the steel pipe 30. The bolt hole to be bored in this embodiment is the bolt hole 30A shown by the solid line in FIG. 2B, and is shown by the broken line in FIG. 2A. The number and size of the openings 21A, 21A, 21A are not particularly limited, and a cutting blade of an electric drill (drilling device) 50, which will be described later, can be inserted, and the marking attached to the steel pipe 30 can be confirmed. It should be possible. The bolt holes 30A, 30A, 30A shown in FIGS. 2(A) and 2(B) are shown for the sake of explanation, and each bolt hole 30A is actually formed at an appropriate position.

Further, as shown in FIGS. 1 and 3, the pair of flange portions 24 and 25 are provided with fixing bolt holes 24A and 25A for attaching (tightening) the fixing bolt 60, respectively, and the pair of collar portions is formed. The spacing W1 between the centers of the fixing bolt holes 24A, 25A provided in 24, 25 is obstructed by the side surface of the parallel steel pipe 30 when the fixing bolts 60, 60 are inserted into the fixing bolt holes 24A, 25A, respectively. It is formed to be slightly longer than the diameter (outer diameter) W2 of the steel pipe 30 so that it can be stretched without being stretched.

Here, in the hole making jig 20 of the present embodiment, a plurality of pairs of flange portions 24 and 25 are provided. For example, the pair of collar portions 24 and 25 are provided in two steps in the height direction of the main body 21. In this case, the pair of jigs 20 for drilling are strongly fixed to the steel pipe 30 by a total of four fixing bolts 60, 60.

[Dimensions of drilling jigs, etc.]
Next, an example of dimensions of the hole making jig 20 will be described. It is assumed here that the jig 20 for punching is suitable when the outer diameter (outer diameter) of the steel pipe 30 is 406.4 mm.
Height of main body 21 h: 660 mm
Distance a from the upper end of the main body 21 to the centers of the fixing bolt holes 24A, 25A: 250 mm
Thickness c of collars 24 and 25: 40 mm
Length d of the side plates 22 and 23: 70 mm
Center distance between fixing bolt holes 24A, 25A W1: 426 mm
Diameter of each fixing bolt hole 24A, 25A: 20 mm
Height difference b between fixing bolt holes 24A, 24A: 160 mm
Height difference b between fixing bolt holes 25A, 25A: 160 mm
Diameter of opening 21A: 60 mm
Center distance e between the uppermost opening 21A and the lowermost opening 21A e: 160 mm
Length of fixing bolt 60: 500 mm
Diameter of fixing bolt 60: 20 mm

[Structure of electric drill]
Next, the electric drill (drilling device) 50 used in the drilling method of the present embodiment will be described. FIG. 6 is a perspective view showing the outline of the electric drill (drilling device) 50, and FIG. 7 is an explanatory view for explaining the drilling work by the electric drill (drilling device).

As shown in the figure, the electric drill (drilling device) 50 includes a main body 54 having a drill motor 52, a rotary shaft assembly 58 driven by the drill motor 52, a cutting blade t attached to the tip of the rotary shaft assembly 58, An operation lever 39 for controlling the drill motor 52, an electromagnetic base 41 containing an electromagnet, a handle 42 for holding an electric drill (drilling device) 50, and the like are provided. As such an electric drill 50, for example, ATRAACE LO-3000A, LO-3550A manufactured by Nitto Kohki Co., Ltd. can be used.

When an operator turns on a power switch (not shown) of the electric drill (drilling device) 50, the electromagnet in the electromagnetic base 41 is energized and a magnetic force is generated in the electromagnetic base 41, so that the bottom surface of the electromagnetic base 41 is flat. It becomes possible to adsorb to a ferromagnetic material. In the present embodiment, since the main body 21 of the above-described hole making jig 20 is made of a flat ferromagnetic material (steel plate), the bottom surface of the electromagnetic base 41 is attracted to the surface of the main body 21 as shown in FIG. It becomes possible. Further, the relative position of the electromagnetic base 41 with respect to the main body 54 can be adjusted. This makes it possible to center the cutting blade t by fixing the bottom surface of the electromagnetic base 41 to the main body 21 of the hole making jig 20 and then finely adjusting the position of the main body 54.

[Procedure for punching]
Next, the procedure of the punching method according to the present embodiment will be described. FIG. 8 is a flow chart showing the procedure of the punching method according to the present embodiment. The hole forming method of the present embodiment uses two hole forming jigs 20, 20 as a pair. Further, here, one of the pair of drilling jigs 20 is referred to as "first steel pipe drilling jig 20", and the other is referred to as "second steel pipe drilling jig 20". Further, a pair of bolt holes 30A symmetrical with respect to the center line of the steel pipe 30 should be bored in three steps in the same arrangement pattern as the three openings 21A, 21A, 21A in the main body 21 (six bolt holes 30A in total). ) Is assumed.

First, an operator marks out a predetermined position on the side surface of the steel pipe 30 where the bolt hole 30A is to be formed (step S1). This marking is performed by any known method, and cross marks (not shown), for example, are provided as marks at the six predetermined positions where the bolt holes 30A are to be drilled.

Next, the worker places the first steel pipe hole-making jig 20 and the second steel pipe hole-making jig 20 at positions facing each other with the steel pipe 30 interposed therebetween, as shown in FIG. 2(A). It is arranged (step S2). At this time, the flange portion 24 of the first steel pipe hole forming jig 20 faces the flange portion 25 of the second steel pipe hole forming jig 20, and the flange portion 25 of the first steel pipe hole forming jig 20 is It faces the collar portion 24 of the jig 20 for punching the second steel pipe. Further, at this time, the three openings 21A, 21A, 21A of the first steel pipe hole forming jig 20 sandwich the steel pipe 30 and the three openings 21A, 21A, 21A of the second steel pipe hole forming jig 20. To face.

Next, the operator uses the six center lines of the openings 21A, 21A, 21A of the main body 21 of both the first steel pipe hole forming jig 20 and the second steel pipe hole forming jig 20 Positioning is performed so as to directly face (cross) the predetermined position (cross line) (step S3).

In parallel with the above-described alignment, the worker is required to fix the fixing bolt hole 24A provided in the collar portion 24 on one side of the first steel pipe hole forming jig 20 and the second steel pipe hole forming jig 20. The fixing bolt hole 25A provided on the flange portion 25 on one side is connected and fixed by the fixing bolt 60, and the fixing portion provided on the flange portion 25 on the other side of the jig 20 for drilling the first steel pipe. The bolt hole 25A for fixing and the fixing bolt hole 24A provided in the flange portion 24 on the other side of the second jig 20 for drilling the steel pipe are connected and fixed by another fixing bolt 60 (step S4).

Here, since the pair of flange portions 24 and 25 are provided in two steps in the height direction of the main body 21, the first steel pipe hole forming jig 20 and the second steel pipe hole forming jig. 20 is fixed to the steel pipe 30 with a total of four fixing bolts 60, 60 in two stages. As a result, the first steel pipe hole forming jig 20 and the second steel pipe hole forming jig 20 are firmly fixed to the steel pipe 30, and the possibility of positional displacement is suppressed. In addition, in step S4, the connecting portions of the bolt holes 24A and 25A and the fixing bolt 60 are fastened by the nuts S, respectively.

Next, as shown in FIG. 7, the worker inserts an electric drill (piercing device) into each of the six predetermined positions (crosshairs) marked out through the openings 21A, 21A, 21A of the main body 21. )50 to form the bolt hole 30A (step S5). At the time of this drilling, the operator sets the electric drill (piercing device) 50 to the main body 21 by magnetic force.

[Details of drilling process]
Here, the process of forming the bolt hole 30A from the opening 21A will be described in detail. First, the operator brings the bottom of the electromagnetic base 41 into close contact with the main body 21 of the steel pipe drilling jig 20 and turns on the switch of the electric drill 50 while the cutting blade t is positioned approximately in the center of the opening 21A. When turned on, the electric drill 50 is magnetically fixed to the main body 21 of the steel pipe drilling jig 20. Then, the operator finely adjusts the position of the main body 54 of the electric drill 50 for centering the cutting blade t so that the rotation axis of the cutting blade t coincides with a predetermined position (cross line) on the side surface of the steel pipe 30. Then, the operator slowly tilts the operation lever 39 of the electric drill 50 to form the bolt hole 30A at a predetermined position (cross line) at the tip of the cutting blade t. Then, when the drilling is completed, the operator turns off the power of the electric drill 50 to eliminate the magnetic force, and proceeds to the next drilling work. The above is the process of forming one bolt hole 30A. Other bolt holes 30 are similarly drilled.

[Effect of Embodiment]
As described above, according to the jig 20 for drilling a steel pipe according to the present embodiment, the steel pipe 30 is held by the body 21 of the drilling jig 20 and the left and right side plates 22 and 23 so as to surround the steel pipe 30 from the side. By fixing the fixing bolt holes 24A, 25A formed in both the collar portions 24, 25 with the fixing bolts 60, 60, the whole jig 20 for fixing holes is fixed to the steel pipe 30. It is possible.

In particular, according to the method for punching a steel pipe according to the present embodiment, the steel pipe 30 is held so as to be sandwiched between the first jig 20 for drilling and the jig 20 for second drilling, It is possible to fix the first hole forming jig 20 and the second hole forming jig 20 to the steel pipe 30 by connecting and fixing the fixing bolt holes 24A and 25A of the above with the fixing bolts 60 and 60. Is. When the bolt hole 30A is drilled at a predetermined position of the steel pipe 30 with the electric drill (piercing device) 50 through the opening 21A, the opening 21A can be used as a mark. It is easy to improve the accuracy of the drilling position. Moreover, since the flat plate-shaped main body 21 is interposed between the predetermined position of the steel pipe 30 and the electric drill (drilling device) 50, and the main body 21 is fixed to the steel pipe 30, the main body during drilling. By maintaining the posture of the electric drill (drilling device) 50 with 21 as a support, it is easy to match the center line of the bolt hole 30A with the normal line of the side surface. Therefore, according to the drilling method of the present embodiment, the bolt holes 30A can be accurately drilled in the side surface of the steel pipe 30 having a cylindrical cross section. Moreover, according to the hole forming method according to the present embodiment, the steel pipe 30 is sandwiched from both sides by the first hole forming jig 20 and the second hole forming jig 20 having the same configuration as each other. There is also an advantage that the positioning can be easily performed when the bolt holes 30A and 30A are formed at positions symmetrical with respect to the center line. Further, the worker can also proceed with the work in a comfortable posture.

[Supplement to Embodiment]
In addition, in the above-described embodiment, the six bolt holes 30A are formed on the side surface of the steel pipe 30 by using the two steel pipe hole forming jigs 20 and 20 provided with three openings 21A. It is not essential to use all of the six openings 21A, and a part (at least one) of the six openings 21A may be used to form the bolt holes 30A of 5 or less in number. Needless to say.

[Modification]
Next, a modified example of the punching method of the present embodiment will be described. FIG. 9 is a diagram illustrating a modified example of the punching method. In the hole drilling method of the above-described embodiment, the two hole drilling jigs 20 and 20 are fixed to the steel pipe 30 with the rod-shaped fixing bolts 60. However, in this modification, one hole drilling jig 20 is used. Is fixed to the steel pipe 30 with a U-shaped fixing bolt (U-shaped bolt 60′). The drilling method of this modification corresponds to the drilling method of the above-described embodiment (FIG. 8) with step S2 omitted. In this modification, three bolt holes 30A are formed on the side surface of the steel pipe 30 in the same arrangement pattern as the openings 21A, 21A, 21A in the main body 21 (a total of three bolt holes 30A are formed). Assume

First, the operator marks out a predetermined position on the side surface of the steel pipe 30 where the bolt hole 30A is to be formed (step S1). This marking is performed by any known method, for example, by marking marks (crosshairs) at three predetermined positions where the bolt holes 30A are to be drilled.

Next, the operator aligns the centers of the openings 21A, 21A, 21A of the main body 21 of the steel pipe boring jig 20 so as to directly face the three predetermined positions (crosshairs) marked out (step). S3).

In parallel with the above-described alignment, the worker, as shown in FIG. 9, the fixing bolt hole 24A provided on the collar portion 24 on one side of the hole forming jig 20 for the steel pipe and the collar portion 25 on the other side. The fixing bolt hole 25A provided in the above is connected and fixed by a U-shaped bolt 60' (step S4). At this time, the U-shaped bolt 60 ′ is arranged so as to surround the steel pipe 30.

Since the pair of flanges 24 and 25 are provided in two steps in the height direction of the main body 21, the steel pipe drilling jig 20 has two U-shaped bolts 60 in total in two steps. It is fixed to the steel pipe 30 with “, 60”. As a result, the steel pipe punching jig 20 is firmly fixed to the steel pipe 30, and the possibility of positional displacement is suppressed. In step S4, the connecting portions of the bolt holes 24A, 25A and the U-shaped bolt 60' are tightened by the nuts S, respectively.

Next, the worker drills the bolt holes 30A with the electric drill (drilling device) 50 through the openings 21A, 21A, 21A of the main body 21 at each of the three predetermined positions (crosshairs) marked out. Drill (step S5). At the time of this drilling work, the operator fixes the electric drill (drilling device) 50 to the main body 21 by magnetic force. The fixing method is the same as in the above-described embodiment.

[Effect of modification]
As described above, according to the drilling method of the present modification, the main body 21 of the drilling jig 20 and the left and right side plates 22 and 23 can hold the steel pipe 30 so as to surround the steel pipe 30 from the side, By connecting the fixing bolt holes 24A, 25A formed in both the flange portions 24, 25 with the U-shaped bolt 60', the entire hole making jig 20 can be fixed to the steel pipe 30. When the bolt hole 30A is drilled at a predetermined position of the steel pipe 30 with the electric drill (piercing device) 50 through the opening 21A, the opening 21A can be used as a mark, so that the bolt hole 30A It is easy to improve the accuracy of the drilling position. Moreover, the flat plate-shaped main body 21 is interposed between the predetermined position of the steel pipe 30 and the electric drill (drilling device) 50, and the main body 21 is fixed to the steel pipe 30. By maintaining the posture of the electric drill (drilling device) 50 using the support as a support, it is easy to match the center line of the bolt hole 30A with the normal line of the side surface. Therefore, according to the drilling method of the present modification, the bolt hole 30A can be drilled with high accuracy on the side surface of the steel pipe 30 having a cylindrical cross section. Further, the worker can also proceed with the work in a comfortable posture.

As described above, the preferred embodiments of the present invention have been described in detail, but the present invention is not limited to the specific embodiments, and within the scope of the gist of the present invention described in the claims, It goes without saying that various modifications and changes are possible.

For example, in the above-described embodiment or modification, the drilling jig 20 suitable for the steel pipe 30 having a specific size (outer diameter) has been described, but the fixing jig described above can be used for various sizes (outer diameter) steel pipes 30. The bolt holes 24A, 25B may be long holes that are long in the left-right direction (the arrangement direction of the pair of collar portions 24, 25) instead of being round holes.

20 Hole Jig 21 Main Body 21A Opening 22 Side Plate 23 Side Plate 30 Steel Pipe 24 Collar 24A Fixing Bolt Hole 25A Fixing Bolt Hole 25 Collar 30A Bolt Hole 32 Holding Member 32c Recessing Bolt 2b Fixing Bolt 2c Fixing Bolt 41 Electromagnetic base 42 Handle 50 Electric drill (drilling device)
52 drill motor 54 main body 58 rotating shaft assembly 60 fixing bolt S nut t cutting blade

Claims (8)

In a jig for drilling a steel pipe for forming a bolt hole on the side surface of a cylindrical steel pipe,
A main body arranged on a side surface of the steel pipe, wherein the main body is provided with one or a plurality of openings at positions facing the surface of the steel pipe,
A fixing structure for fixing the main body to the side surface of the steel pipe,
A jig for punching a steel pipe, characterized by being provided with. The jig for punching a steel pipe according to claim 1,
The main body has a flat plate shape,
A jig for punching a steel pipe, comprising a pair of side plates standing upright on the left and right of the flat plate-shaped main body as at least a part of the fixing structure. The jig for punching a steel pipe according to claim 2,
A pair of flanges formed on the outside of the left and right side plates is provided as at least a part of the fixing structure,
A jig for punching a steel pipe, wherein each of the pair of collars is provided with a fixing bolt hole for attaching a fixing bolt. The jig for punching a steel pipe according to claim 3,
A jig for punching a steel pipe, wherein a plurality of the pair of flanges are provided. A drilling method using the drilling jig for a steel pipe according to any one of claims 1 to 4,
Marking out a predetermined position on the side surface of the steel pipe in which a bolt hole is to be bored,
Arranging a first jig for punching the steel pipe and a second jig for punching the steel pipe at positions facing each other with the steel pipe sandwiched therebetween;
A step of aligning so that the opening of one or both of the first steel pipe hole forming jig and the second steel pipe hole forming jig directly faces the predetermined position where the opening is marked out,
Fixing the first jig for punching the steel pipe and the jig for punching the second steel pipe with each other by the fixing structure;
A step of drilling a bolt hole by a drilling device through the opening of the main body with respect to a predetermined position that has been marked out;
A method for forming a hole, which comprises: A drilling method using the jig for drilling a steel pipe according to claim 5,
A method of drilling a hole, wherein a bolt hole is drilled while the drilling device is fixed to the main body by magnetic force. A drilling method using the drilling jig for a steel pipe according to any one of claims 1 to 4,
Marking out a predetermined position on the side surface of the steel pipe in which a bolt hole is to be bored,
Aligning the opening of the main body of the jig for punching the steel pipe so as to face the predetermined position marked out;
Fixing one side and the other side of the hole forming jig of the steel pipe by the fixing structure,
A step of drilling a bolt hole by a drilling device through the opening of the main body with respect to a predetermined position that has been marked out;
A method for forming a hole, which comprises: The punching method according to any one of claims 5 to 7,
A drilling method, wherein the steel pipe is a steel pipe pile.

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