Positioning jig for ground plate reference line

Abstract

To provide a positioning jig for a ground plate reference line which facilitates work to draw a reference line for satisfying standard installation specifications by simultaneously adding the reference line to a plurality of ground plates.SOLUTION: A positioning jig 1 comprises a placement table 2 including a placement board 3 including a placement surface 3a and sidewalls 4 and 5 which are erected on the placement surface 3a. The placement board 3 includes an upper edge 3b, a lower edge 3c in parallel with the upper edge 3b, and rod bodies 6 and 7 which are inserted through installation holes 55 and 56 a ground plate 50 includes. The sidewalls 4 and 5 include inner wall surfaces 4a and 5a to which side end faces 53 and 54 of the ground plate 50 are abutted, and sidewall lower edges 4b and 5b forming the same plane with the lower edge 3c of the placement board 3. In a case where an upper end face 51 of the ground plate 50 matches the upper edge 3b of the placement board 3, both end points La and Lb of a reference line are present on straight lines L1 and L1 which match the sidewall lower edges 4b and 5b.SELECTED DRAWING: Figure 4

Description

Technical Field

[0001] The present invention relates to a positioning jig used when attaching a reference line to a grounding plate when attaching the grounding plate to a tower member, and more particularly to a positioning jig for a grounding plate reference line that can attach the reference line to a plurality of grounding plates simultaneously.

Background Art

[0002] Conventionally, in overhead power line work, there is a risk of electric shock to workers due to induced current flowing from the energized wire to the de-energized working-side wire by electromagnetic induction and electrostatic induction. Therefore, grounding is performed from the working-side wire to the tower support with a low resistance value via a ground wire to prevent electric shock. However, since an induced electric shock disaster occurred due to insufficient grounding, grounding plates are sequentially attached to all towers as a disaster prevention measure for induced electric shock disasters in order to surely ensure the grounding resistance value. In the work of attaching the grounding plate, as preparation, after workers use a ruler or the like on each tower to determine the drilling position for attachment, they drill the attachment holes using tools. Measurement of such drilling positions and actual drilling work take about 5 to 10 minutes per grounding plate. Therefore, for the number of grounding plates per tower (more than a dozen), there are problems that the working time increases and the burden on the work is large. Therefore, in recent years, technologies that can reduce the work burden have been developed, and inventions related thereto have already been disclosed.

[0003] Patent Document 1 discloses an invention related to a method for attaching a grounding member to a power transmission tower with a reduced burden on workers, named "Method for Attaching a Grounding Member to a Power Transmission Tower and a Grounding Plate Used for the Attaching Method". The invention disclosed in Patent Document 1 is an attachment method for attaching a grounding member for grounding to a transmission tower composed of tower members via an attachment member. The method includes a removal step of obtaining an empty existing hole by removing a fixing part and a mounting part from the tower member, a positioning step of determining the position of the grounding member using the grounding member with mounting holes formed therein so that the empty existing hole and the mounting holes overlap, and an attachment step of inserting the attachment member through the overlapping empty existing hole and mounting holes to attach the grounding member to the tower member. In such an invention, two large holes and two small holes are formed in a row in the grounding member. The empty existing holes provided in the tower member are two large-diameter empty existing holes or two small-diameter empty existing holes. Therefore, in the positioning step, the position of the grounding member is determined such that the overlapping portion of the grounding plate is overlapped with the surface of the tower member to be attached and the center of the large-diameter empty existing hole and the center of the large hole overlap. Alternatively, the position of the grounding member is determined such that the center of the small-diameter empty existing hole and the center of the small hole overlap. In such a method, it is easy for the operator to notice an error in positioning the grounding member. Therefore, the grounding member can be accurately attached to the tower member.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] In the invention disclosed in Patent Document 1, the position of the grounding member is determined such that the center of the large-diameter empty existing hole and the center of the large hole overlap, or the center of the small-diameter empty existing hole and the center of the small hole overlap. Therefore, what is easy for the operator to notice is an error in positioning in the longitudinal direction of the tower member. Here, regarding the short side direction of the tower member, it is necessary to follow the standard mounting specification. This standard mounting specification means attaching the grounding member to the tower member with the edge of the grounding member protruding a certain distance (80 mm) from the edge of the tower member. Therefore, if a reference line indicating this certain distance is attached to the grounding member, it is easier to satisfy the standard mounting specification. However, in the invention disclosed in Patent Document 1, since the reference line is not attached to the grounding member, it is difficult for the operator to notice a positioning error in the short side direction of the tower member, and there is a risk that the standard mounting specification may not be satisfied. If, in consideration of this point, the operator attaches the reference line to each of the plurality of grounding members one by one, it takes a corresponding amount of labor and time, which is not preferable in terms of work efficiency. Therefore, in the invention disclosed in Patent Document 1, there is a possibility that the conventional problems of an increase in work time and a large burden on the work cannot be sufficiently solved.

[0006] The present invention has been made in view of such conventional circumstances, enables a reference line for satisfying the standard mounting specification to be simultaneously attached to a plurality of grounding plates, facilitates the work of attaching this reference line, and aims to provide a positioning jig for the grounding plate reference line that enables the positioning work of the grounding plate in the short side direction of the tower member to be accurately and easily carried out.

Means for Solving the Problem

[0007] In order to achieve the above object, a first invention is a positioning jig for a ground plate reference line for attaching a reference line, which serves as a position reference when attaching a ground plate in a square plate shape to a tower member, to the ground plate. The positioning jig includes a mounting table having a mounting surface on which the ground plate is placed, and a pair of side walls erected on the mounting surface. The mounting plate has an upper edge and a lower edge parallel to the upper edge. The pair of side walls have a pair of inner wall surfaces against which the pair of side end faces of the ground plate respectively abut, and a pair of side wall lower edges that form the same plane as the lower edge of the mounting plate. When the ground plate is placed on the mounting surface, the length of the mounting plate along the pair of side walls is shorter than the length of the ground plate along the pair of side walls. When the upper end face of the ground plate coincides with the upper edge of the mounting plate, the reference line has both endpoints respectively existing on a pair of straight lines that coincide with the pair of side wall lower edges.

[0008] In the invention having such a configuration, the upper end face of the ground plate is a surface that will be along the longitudinal direction of the tower member when the ground plate is attached to the tower member. Also, the pair of side end faces and the length of the ground plate of the ground plate are the surfaces and lengths that will be along the short-side direction of the tower member respectively when the ground plate is attached to the tower member. Furthermore, the ground plate may have a square shape with chamfered corners. That is, the ground plate only needs to be substantially square plate-shaped.

[0009] Also, considering the strength resistance when a plurality of metal ground plates are placed on the mounting surface, it is desirable that the mounting table and the rod body are made of metal with rigidity. Furthermore, each side wall lower edge of the pair of side walls forms the same plane as the lower edge of the mounting plate, but for the upper edge of the mounting plate, there is no relevance with the pair of side walls like the lower edge of the mounting plate. Note that the same plane is a virtual plane.

[0010] In the invention having the above configuration, the length of the mounting plate along the pair of side walls is shorter than the length of the ground plate along the pair of side walls. Therefore, when the ground plate is placed on the mounting surface so that the upper end face of the ground plate coincides with the upper edge of the mounting plate, in a side view, the lower end face of the ground plate will protrude a certain distance from the lower edge of the mounting plate.

[0011] This protruding fixed distance is the reference distance required to make the lower end surface of the grounding plate protrude from the edge of the tower member as defined by the aforementioned standard mounting specification. Therefore, the straight line that coincides with the lower edge of the placement plate becomes the reference line for the position reference when attaching the grounding plate to the tower member. However, since the straight line that coincides with the lower edge of the placement plate is hidden on the back side of the grounding plate, it is difficult to directly attach this straight line to the grounding plate. Therefore, since the lower edge of each side wall of the pair of side walls forms the same plane as the lower edge of the placement plate, the reference line will have its two endpoints respectively on a pair of straight lines that coincide with the lower edges of the pair of side walls. Therefore, this pair of straight lines will be respectively attached to the pair of side end faces of the grounding plate.

[0012] Also, since the pair of side walls have a pair of inner wall surfaces against which the pair of side end faces of the grounding plate respectively abut, when placing a plurality of grounding plates on the placement surface, the orientation of these grounding plates in the lateral direction (the direction perpendicular to the pair of side end faces of the grounding plate) is likely to be aligned.

[0013] A second invention is characterized in that, in the first invention, the placement plate is provided with a rod body that passes through the mounting holes of the grounding plate on the placement surface. In the invention with such a configuration, a cylindrical body or a prismatic body can be considered as the rod body. Also, the rod body can be either solid or hollow. Furthermore, the rod body may or may not be removable from the placement surface. For example, in the former case, a configuration can be considered in which a protruding portion that can be inserted into the interior of the hollow rod body is provided on the placement surface.

[0014] In the invention with the above configuration, in addition to the effect of the first invention, when placing a plurality of grounding plates on the placement surface, since the rod body passes through the mounting holes of the grounding plate, in addition to the orientation of these grounding plates in the lateral direction, the orientation of the grounding plates in the longitudinal direction (the direction parallel to the pair of side end faces of the grounding plate) is also likely to be aligned.

[0015] The third invention is an invention according to the second invention, characterized in that one end of the rod body is formed with a first threaded portion, the mounting surface is formed with a hole portion having a depth in a direction orthogonal to the mounting surface, and the hole portion is formed with a second threaded portion on its circumferential surface, into which the first threaded portion is screwed. In the invention having such a configuration, as the hole portion, in addition to the recess having a bottom portion, a through hole having no bottom portion can be considered.

[0016] In the invention having the above configuration, in addition to the action of the second invention, since the hole portion is formed with a second threaded portion into which the first threaded portion is screwed, one end of the rod body is detachable from the hole portion. Therefore, when interference occurs between the mounting hole of the grounding plate and the rod body by inserting the rod body through the mounting hole of the grounding plate, if one end of the rod body is removed from the hole portion, this interference is eliminated.

[0017] The fourth invention is an invention according to the first or second invention, characterized in that the height of the side wall from the mounting surface is not less than twice the thickness of the grounding plate. In the invention having such a configuration, in addition to the action of the first or second invention, since the height of the side wall from the mounting surface is not less than twice the thickness of the grounding plate, when two or more grounding plates are placed on the mounting surface, the pair of side walls hold the two or more grounding plates without collapsing.

Advantages of the Invention

[0018] According to the first invention, by attaching a pair of straight lines that coincide with the lower edges of the pair of side walls to the pair of side end faces of the grounding plate respectively, both end points of the reference line are displayed on the pair of side end faces. Therefore, the reference line can be attached to the grounding plate simply and accurately. This is the same even when a plurality of grounding plates are stacked and placed on the mounting surface, so that the reference line can be attached to the plurality of grounding plates simultaneously. Therefore, the first invention facilitates the operation of attaching the reference line and enables the positioning operation of the grounding plate in the short side direction of the tower member to be performed accurately and easily.

[0019] According to the second invention, in addition to the effect of the first invention, when placing a plurality of grounding plates on the placement surface, since the lateral and longitudinal directions of these grounding plates are likely to be aligned, a pair of straight lines that coincide with the lower edges of the pair of side walls can be more accurately attached to the pair of side end faces of all the grounding plates.

[0020] According to the third invention, in addition to the effect of the second invention, one end of the rod body can be removed from the hole portion. As a result, the interference between the mounting hole and the rod body is eliminated, making it easier to correct the position when placing the grounding plate. Also, after attaching a pair of straight lines that coincide with the lower edges of the pair of side walls to the pair of side end faces of the grounding plate, it becomes possible to smoothly lift the grounding plate from the placement surface.

[0021] According to the fourth invention, in addition to the effect of the first or second invention, since two or more grounding plates are held by the pair of side walls without collapsing, the safety when attaching a pair of straight lines that coincide with the lower edges of the pair of side walls can be ensured.

Brief Description of the Drawings

[0022]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Modes for Carrying Out the Invention

Examples

[0023] First, before explaining the configuration of the ground plate reference line positioning jig according to an embodiment of the present invention, the configuration of the ground plate will be described with reference to FIG. 5. FIG. 5(a) is a plan view showing the configuration of the ground plate, and FIG. 5(b) is a plan view showing the mounting state in which the ground plate is attached to the tower member. As shown in FIGS. 5(a) and 5(b), the ground plate 50 includes upper and lower end faces 51 and 52 that are parallel to each other, and side end faces 53 and 54 that connect the upper and lower end faces 51 and 52, respectively, and has a substantially square plate shape. Further, the ground plate 50 has mounting holes 55 and 56, and a ground mark 57 engraved on the surface of the ground plate 50. Also, a dotted line parallel to the upper end face 51 is a reference line L attached to the ground plate 50 by using the ground plate reference line positioning jig. r Here, in the ground plate 50, the direction parallel to the upper end face 51 and the lower end face 52 is the horizontal direction (W direction), and the direction along the side end faces 53 and 54 is the vertical direction (L direction).

[0024] Next, the shape of the mounting holes 55 and 56 and their arrangement on the ground plate 50 will be described in detail. As shown in FIG. 5(a), the mounting holes 55 and 56 each have a center point 55a and 56a. Also, the distance D1 from the upper end face 51 along the side end faces 53 and 54 to the reference line L r is 50 mm. Further, the reference distance D, which is on the extension of the distance D1 and is defined as a standard mounting specification, is 80 mm. Therefore, the ground plate length in the vertical direction (L direction) of the ground plate 50 is the distance (D + D1), which is 130 mm. And the distance D2 from the side end face 53 to the side end face 54 along the upper end face 51 is 200 mm.

[0025] Subsequently, as shown in FIG. 5(b), the mounting holes 55 and 56 are formed so as to overlap with existing holes 61 and 62 provided along the longitudinal direction (X direction) of the tower member 60. Specifically, the mounting holes 55 and 56 are formed at positions where bolts B and B can be inserted into the mounting holes 55 and 56 and the existing holes 61 and 62, respectively. Therefore, the grounding plate 50 can be attached to the tower member 60 by bolting at the mounting holes 55 and 56.

[0026] However, even if the grounding plate 50 can be attached to the tower member 60 by bolting, it is necessary to check whether the reference distance D is ensured in the short direction (Y direction) of the tower member 60. This reference distance D is the distance from the edge 63 of the tower member 60 to the lower end surface 52 of the grounding plate 50 along the short direction of the tower member 60. However, since the reference line L indicating the reference distance D r is not yet formed on the grounding plate 50, the operator has to use a ruler to check the reference distance D, which is a burden. Therefore, in order to eliminate such a burden, the operator uses a positioning jig for the grounding plate reference line to align the reference line L r or both end points of the reference line Lr with the edge 63 of the tower member 60 in advance on the grounding plate 50.

[0027] Next, the positioning jig for the grounding plate reference line according to the embodiment of the present invention will be described in detail with reference to FIGS. 1 to 4. FIG. 1(a) is a side view of the positioning jig for the grounding plate reference line according to the embodiment, and FIG. 1(b) is a view taken in the direction of arrow A in FIG. 1(a). Note that the components shown in FIG. 5 are denoted by the same reference numerals in FIG. 1, and the description thereof is omitted. As shown in FIG. 1, the positioning jig 1 for the grounding plate reference line according to the embodiment (hereinafter referred to as the positioning jig 1) is a jig for attaching a reference line L r which serves as a positioning reference when attaching the grounding plate 50 (see FIG. 5) having the mounting holes 55 and 56 to the tower member 60 (see FIG. 5(b)) to the grounding plate 50.

[0028] The positioning jig 1 includes a mounting table 2. The mounting table 2 has a mounting plate 3 having a mounting surface 3a on which the grounding plate 50 is mounted, and side walls 4 and 5 that are orthogonal to the mounting surface 3a and are erected on the mounting surface 3a, and has a rectangular box shape in side view. Then, for the side walls 4 and 5, the height h from the placement surface 3a is at least twice the thickness T of the grounding plate 50 (see Fig. 4(a)). In this embodiment, the height h is approximately eight times the thickness T of the grounding plate 50.

[0029] Further, the placement plate 3 is provided with rods 6 and 7 that respectively pass through the mounting holes 55 and 56 of the grounding plate 50 on the placement surface 3a. Note that both the mounting table 2 and the rods 6 and 7 are made of metal with rigidity. Furthermore, the placement surface 3a is configured with recesses 8 and 9 having a depth in a direction orthogonal to the placement surface 3a. Specifically, the recesses 8 and 9 are recesses having a bottom surface. However, the recesses 8 and 9 may be through holes without a bottom surface.

[0030] Next, first screw portions 10 and 10 are respectively formed at one ends 6a and 7a of the rods 6 and 7. Also, the rods 6 and 7 have central axes A6 and A7 in their longitudinal directions. In addition, second screw portions 11 and 11 that engage with the first screw portions 10 and 10 are respectively formed on the peripheral surfaces of the recesses 8 and 9. Therefore, the rods 6 and 7 are detachable from the recesses 8 and 9 at one ends 6a and 7a. Note that Fig. 1 shows a state where the first screw portions 10 and 10 of the rods 6 and 7 are not engaged with the second screw portions 11 and 11 of the recesses 8 and 9.

[0031] Subsequently, the placement plate will be described with reference to Figs. 2 and 3. Fig. 2(a) is a plan view of the mounting table that constitutes the positioning jig for the grounding plate reference line according to the embodiment, and Fig. 2(b) is a perspective view of the mounting table when viewed obliquely from above. Fig. 3 is a plan view of the mounting table that constitutes the positioning jig for the grounding plate reference line according to the embodiment with the grounding plate mounted thereon. Note that the components shown in Figs. 1 and 5 are given the same reference numerals in Figs. 2 and 3, and their descriptions are omitted. As shown in Figs. 2 and 3, the placement plate 3 has an upper edge 3b and a lower edge 3c parallel to the upper edge 3b. Further, the side walls 4 and 5 have inner wall surfaces 4a and 5a against which the side end surfaces 53 and 54 of the ground plate 50 abut, respectively, and lower side wall edges 4b and 5b that form a virtual plane S identical to the lower edge 3c of the mounting plate 3.

[0032] Furthermore, as shown in FIGS. 2(a) and 3, in the mounting plate 3, the length d1 of the mounting plate from the upper edge 3b to the lower edge 3c along the side walls 4 and 5 is equal to the distance D1 of the ground plate 50. Therefore, as shown in FIG. 3, when the upper end surface 51 of the ground plate 50 is aligned with the upper edge 3b of the mounting plate 3 and the ground plate 50 is placed on the mounting surface 3a, the mounting plate length d1 is shorter than the ground plate length (distance (D + D1)) of the ground plate 50 along the side walls 4 and 5. That is, the distance by which the lower end surface 52 of the ground plate 50 protrudes from the lower edge 3c of the mounting plate 3 is the reference distance D.

[0033] Also, the distance d2 from the inner wall surface 4a to the inner wall surface 5a along the upper edge 3b of the mounting plate 3 is equal to the distance D2 of the ground plate 50. In addition, the holes 8 and 9 have center points 8a and 9a. These center points 8a and 9a coincide with the center points 55a and 56a of the mounting holes 55 and 56 of the ground plate 50 and also coincide with the central axes A6 and A7 of the rods 6 and 7.

[0034] Subsequently, the usage state of the positioning jig 1 will be described with reference to FIG. 4. FIG. 4(a) is a side view showing the usage state of the positioning jig for the ground plate reference line according to the embodiment, and FIG. 4(b) is a view taken in the direction of arrow B in FIG. 4(a). Note that the components shown in FIGS. 1, 2, 3, and 5 are denoted by the same reference numerals in FIG. 4, and their descriptions are omitted. As shown in FIG. 4, to use the positioning jig 1, first, one ends 6a and 7a of the rods 6 and 7 are inserted into the holes 8 and 9, and the first screw portions 10 and 10 and the second screw portions 11 and 11 are screwed together, respectively. Thereby, the rods 6 and 7 are erected on the mounting surface 3a. Here, if the lengths of the rods 6 and 7 in the direction of the central axes A6 and A7, which do not include the first screw portions 10 and 10, are designed to be equal to or greater than the height h from the mounting surface 3a of the side walls 4 and 5, the rods 6 and 7 can be easily grasped even when a plurality of grounding plates 50 are placed on the mounting surface 3a.

[0035] Next, a plurality of grounding plates 50 are placed on the mounting surface 3a such that the upper end surface 51 of the grounding plate 50 coincides with the upper edge 3b of the mounting plate 3, and the rods 6 and 7 respectively pass through the mounting holes 55 and 56 of the grounding plate 50. Also, since the lower edges 4b and 5b of the side walls 4 and 5 form the same virtual plane S (see Fig. 2(b)) as the lower edge 3c of the mounting plate 3, the reference line L r has both endpoints L a , L b existing on the straight lines L1 and L1 that coincide with the lower edges 4b and 5b of the side walls respectively. Therefore, when using a pen or the like to draw the straight lines L1 and L1 on the side end surfaces 53 and 54 of a plurality of grounding plates 50, the reference line L r can be obtained for all of these grounding plates 50.

[0036] However, before attaching the reference line L r to the grounding plate 50 based on the drawn straight lines L1 and L1, a plurality of grounding plates 50 are sequentially lifted from the mounting surface 3a. Depending on the lifting direction, the grounding plate 50 may be inclined with respect to the mounting surface 3a. In this case, since both the grounding plate 50 and the rods 6 and 7 are made of metal having rigidity, the mounting holes 55 and 56 of the grounding plate 50 and the rods 6 and 7 may interfere with each other, making it difficult to lift the grounding plate 50 from the mounting surface 3a. However, even if such interference occurs, since the rods 6 and 7 are detachable from the holes 8 and 9, they can be removed from the holes 8 and 9. Thereby, the interference between the mounting holes 55 and 56 and the rods 6 and 7 is eliminated.

[0037] According to the positioning jig 1 configured as described above, since the two or more ground plates 50 are held by the side walls 4 and 5 provided on the mounting table 2 without collapsing, it is possible to ensure safety when applying the straight lines L1 and L1, and it is possible to prevent redoing the application of the straight lines L1 and L1. Further, since the side walls 4 and 5 have inner wall surfaces 4a and 5a with which the side end surfaces 53 and 54 of the ground plate 50 respectively come into contact, when placing a plurality of ground plates 50 on the placement surface 3a, the lateral (W direction) orientations of these ground plates 50 are likely to be aligned. Furthermore, since the rods 6 and 7 are inserted through the mounting holes 55 and 56 of the ground plate 50, in addition to the lateral orientation of the ground plate 50, the longitudinal (L direction) orientation thereof is also likely to be aligned. Therefore, according to the positioning jig 1, the straight lines L1 and L1 can be accurately applied to the side end surfaces 53 and 54 of a plurality of ground plates. Furthermore, interference between the mounting holes 55 and 56 and the rods 6 and 7, which will be described later, can be suppressed.

[0038] Also, since the lower edges 4b and 5b of the side walls 4 and 5 form the same virtual plane S as the lower edge 3c of the mounting plate 3, the straight lines L1 and L1 can be obtained without mistake. And when these straight lines L1 and L1 are drawn on the side end surfaces 53 and 54 of a plurality of ground plates 50, for all of the plurality of ground plates 50, the reference line L r can be obtained simultaneously. Therefore, according to the positioning jig 1, the positioning work of the ground plate 50 in the short side direction of the tower member 60 becomes accurate and easy, and the burden of the work of applying the reference line L r can be reduced.

[0039] In addition, when the rods 6 and 7 are removed from the holes 8 and 9, the interference between the mounting holes 55 and 56 and the rods 6 and 7 is eliminated, so that it becomes easy to correct the position when placing the ground plate 50 on the placement surface 3a. Furthermore, after applying the straight lines L1 and L1 to the side end surfaces 53 and 54 of the ground plate 50, it becomes possible to smoothly lift the ground plate 50 from the placement surface 3a. Also, although the positioning jig 1 has a simple configuration including the mounting table 2 and the rods 6 and 7, for all of the plurality of ground plates 50, the reference line L rSince it can exhibit excellent effects such as being obtained simultaneously, it can be expected that the positioning jig 1 will be introduced at many business sites.

[0040] Note that the positioning jig for the ground plate reference line according to the present invention is not limited to that shown in the embodiment. For example, the holes 8 and 9 may be omitted, and the rods 6 and 7 may be configured not to be removable from the mounting plate 3. Also, the rods 6 and 7 may be omitted. Further, the height h of the side walls 4 and 5 from the mounting surface 3a is not limited to 8 times the thickness T of the ground plate 50, and may be 2 times or more.

Industrial Applicability

[0041] The present invention can be used as a positioning jig for a ground plate reference line used when attaching a reference line to a ground plate when attaching the ground plate to a tower member.

Explanation of Reference Numerals

[0042] 1... Positioning jig 2... Mounting table 3... Mounting plate 3a... Mounting surface 3b... Upper edge 3c... Lower edge 4, 5... Side walls 4a, 5a... Inner wall surfaces 4b, 5b... Lower edges of side walls 6, 7... Rods 6a, 7a... One ends 8, 9... Holes 8a, 9a... Center points 10... First screw portion 11... Second screw portion 50... Ground plate 51... Upper end surface 52... Lower end surface 53, 54... Side end surfaces 55, 56... Mounting holes 55a, 56a... Center points 57... Earth mark D... Reference distance L r ... Reference line 60... Tower member 61, 62... Existing holes 63... Edge

Claims

1. A positioning jig for a ground plate reference line for attaching a reference line, which serves as a position reference when attaching a ground plate in the shape of a rectangular plate to a tower member, to the ground plate, comprising: a mounting table having a mounting surface on which the ground plate is mounted, and a pair of side walls erected on the mounting surface; the mounting plate has an upper edge and a lower edge parallel to the upper edge; the pair of side walls have a pair of inner wall surfaces against which the pair of side end faces of the ground plate respectively abut, and a pair of side wall lower edges forming the same plane as the lower edge of the mounting plate; when the ground plate is placed on the mounting surface, the length of the mounting plate along the pair of side walls is shorter than the length of the ground plate along the pair of side walls; when the upper end face of the ground plate coincides with the upper edge of the mounting plate; the reference line is characterized in that both end points thereof are respectively on a pair of straight lines that coincide with the pair of side wall lower edges. A positioning jig for a ground plate reference line.

2. The positioning jig for a ground plate reference line according to claim 1, wherein the mounting plate is provided with a rod body that penetrates a mounting hole of the ground plate on the mounting surface.

3. One end of the rod body is formed with a first screw portion; the mounting surface is configured with a hole portion having a depth in a direction orthogonal to the mounting surface; the hole portion is formed with a second screw portion on its peripheral surface, with which the first screw portion is screwed. The positioning jig for a ground plate reference line according to claim 2.

4. The positioning jig for a ground plate reference line according to claim 1 or claim 2, wherein the height of the side wall from the mounting surface is not less than twice the thickness of the ground plate.

Images