Reference point indicating apparatus
Patent Information
- Application Number
- JP2022199990
- Authority / Receiving Office
- JP · JP
- Patent Type
- Applications
- Current Assignee / Owner
- Priority Date
- 2022-02-03
- Filing Date
- 2022-12-15
- Publication Date
- 2025-12-22
Smart Images
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Abstract
Description
Technical field
[0001] The present invention relates to a reference point designating device for designating a reference point for measuring various members. [Background technology]
[0002] When measuring the positions of various members constructed at a construction site or the like, it is necessary to specify points that serve as reference points for measuring the various members. For example, if the material is a piled concrete pile and the center of the concrete pile is specified as a reference point, the conventional method is to measure the top surface of the piled concrete pile with a convex, etc., and find the center position using a writing instrument. , etc., to mark the center point.
[0003] In the conventional method, there are problems such as the occurrence of human error, the accuracy depends on the skill of the operator, and the work efficiency is not good. [Prior art documents] [Patent document]
[0004] [Patent document 1] JP-A-2002-67584 [Outline of the invention] [Problems to be solved by the invention]
[0005] SUMMARY OF THE INVENTION The present invention provides a reference point designating device capable of easily designating a point that serves as a reference for measurement of a predetermined member. [Means for solving the problem]
[0006] The present invention comprises at least two link plates, sliding grooves respectively formed in the link plates, and an indicator which is slidable along each sliding groove and provided at the intersection of the center lines of each sliding groove. and at least three legs provided on the same circumference centered on the pointing device, and the pointing device is the perpendicular bisector of each straight line connecting the centers of the adjacent legs. The legs are positioned at intersections, and the legs can contact the object to be measured by sliding the indicator, and the indicator designates the reference point of the object to be measured while each leg is in contact with the object to be measured. The present invention relates to a configured reference point designating device.
[0007] Further, according to the present invention, the link plate is fan-shaped with a predetermined central angle, and is rotatably connected to the adjacent link plate through a connecting point at one peripheral end, and the center line of the sliding groove is the above-mentioned The present invention relates to a reference point designating device constructed so as to be positioned on the perpendicular bisector of a straight line connecting both circumferential ends of a link plate.
[0008] Further, according to the present invention, the link plate is T-shaped, and has a shaft portion having a connection point for rotatably connecting with an adjacent link plate, and a sliding portion in which the sliding groove is formed. , the reference point designating device is constructed so that the center line of the sliding groove is positioned on the perpendicular bisector of the shaft portion.
[0009] Further, the present invention relates to a reference point designating device configured so that a circle centered on the pointing tool and passing through the connection point and a circle centered on the pointing tool and passing through the leg are the same or concentric circles. is.
[0010] Further, the present invention relates to a reference point designating device in which a slit is formed in the link plate so that the contact between the leg portion and the object to be measured can be visually recognized.
[0011] Further, the present invention has a tilting portion capable of tilting in a contact direction of the leg portion with respect to the object to be measured, the link plate is provided with a fixed marker, and a movable marker is provided on the top surface of the tilting portion. The lower end of the tilting portion is urged to protrude in the direction of the pointing device more than the leg portion, and the leg portion and the lower end of the tilting portion become flush with each other due to the contact of the object to be measured. The present invention relates to a reference point designating device constructed so as to match with a movable marker.
[0012] Further, according to the present invention, the pointing device comprises a holder, an offset bar provided rotatably around the holder and having a guide groove, and a reference measurement object provided slidably along the guide groove. and the reference measurement object is a reference point designating device configured to be able to designate an offset point offset by a predetermined distance in a predetermined direction with respect to the reference point.
[0013] The present invention also relates to a reference point designating device provided with biasing means for biasing a circle centered on the pointing tool and passing through each leg in a direction of enlarging or contracting.
[0014] The present invention also relates to a reference point designating device in which the pointing tool includes a retroreflector or a transfer tool.
[0015] The present invention also relates to a reference point designating device in which the pointing tool includes a prism attached via a vertically extendable extendable tool.
[0016] Further, the present invention relates to a reference point designating device in which a height adjusting member is provided adjacent to each leg, and the lower surface of the height adjusting member is positioned on the same plane as the lower surface of the pointing tool. It is a thing.
[0017] Furthermore, the present invention relates to a reference point designating device in which the height adjusting member has a guide portion whose thickness gradually increases from the center side toward the outer circumference side.
Effect of the invention
[0018] According to the present invention, there are at least two link plates, sliding grooves respectively formed in the link plates, and sliding grooves slidable along the respective sliding grooves and provided at intersections of center lines of the respective sliding grooves. and at least three legs provided on the same circumference centered on the pointing device, and the pointing device is a vertical bisector of each straight line connecting the centers of adjacent legs The legs are positioned at intersections of the lines, and the legs can come into contact with the object to be measured by sliding the indicator, and the indicator designates a reference point of the object to be measured while each leg is in contact with the object to be measured. Therefore, there is no need to measure the dimensions of the object to be measured in order to designate the reference point, thereby shortening the working time and reducing the working labor. [Brief description of the drawing]
[0019]
Figure 1
Figure 2
[0020] Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0021] First, referring to FIG. 1, a first embodiment of the present invention will be described.
[0022] In FIG. 1, 1 indicates a reference point specifying device, and 2 indicates a surveying device such as a total station.
[0023] The reference point designating device 1 is attached to an object 3 to be measured. The object 3 to be measured is a construction member provided at a construction site, for example, a plurality of cylindrical concrete piles piled at the construction site.
[0024] The reference point designating device 1 is capable of designating a reference point of the object 3 to be measured, for example, the center of a circle. For example, the reference point designating device 1 may be provided with a writing implement such as a marker, and the center point of a circle may be marked with the writing implement.
[0025] Alternatively, as shown in FIG. 1, the reference point specifying device 1 may be provided with a retroreflector such as a prism 4 as a reference measurement object for specifying the position of the reference point. By measuring the prism 4 with the surveying device 2, the three-dimensional coordinates of the center point of the measurement object 3 can be obtained. A reflective sheet or the like may be used as the retroreflector. Further, the reference measurement object provided in the reference point designating device 1 is not limited to the retroreflector. For example, any object that can be measured as a reference point (for example, the center), such as a three-dimensional object, a luminous body, or a target marker, can be provided in the reference point specifying device 1 as a reference measurement object.
[0026] Next, the reference point specifying device 1 will be described with reference to FIGS. 2(A) and 2(B).
[0027] The reference point designating device 1 has at least two link plates with a predetermined central angle. In the first embodiment, the reference point specifying device has three fan-shaped link plates having a central angle of, for example, 60° and the same radius. The reference point designating device 1 is composed of link plates of the same shape. In the following description, the peripheral edge of the arc centered on the fan-shaped center of each link plate will be referred to as the peripheral edge of each link plate, and the two peripheral edges of each link plate will be referred to as both peripheral edges. there is
[0028] The first link plate 5 and the second link plate 6 are rotatably connected in a superimposed state at a first connection point 7 located at a circumferential end (one circumferential end of the second link plate 6). It is In addition, the second link plate 6 and the third link plate 8 rotate while being overlapped at a second connection point 9 located at the peripheral end (the other peripheral end of the second link plate 6). freely connected. That is, the second link plate 6 is connected to the first link plate 5 and the third link plate 8 at both peripheral ends so that the link plates 5, 6 and 8 do not rotate independently. It has become.
[0029] In the first embodiment, the second link plate 6 is superimposed on the third link plate 8, and the first link plate 5 is superimposed on the second link plate 6. , It is possible to stack three link plates.
[0030] At one peripheral end of the first link plate 5, which is the peripheral end opposite to the first connection point 7 in FIG. 11 is provided, and the first projecting piece 11 is provided with a cylindrical first leg portion 12 protruding downward. Similarly, at one peripheral end of the second link plate 6, which is the peripheral end on the side of the first connection point 7 in FIG. A piece 13 is provided, and the second projecting piece 13 is provided with a cylindrical second leg portion 14 projecting downward. At one peripheral end of the third link plate 8, which is the peripheral end opposite to the second connection point 9 in FIG. 15 is provided, and the third projecting piece 15 is provided with a cylindrical third leg portion 16 protruding downward. The first leg portion 12, the second leg portion 14, and the third leg portion 16 are cylinders with the same radius. It should be noted that each leg 12, 14, 16 only needs to have a height that allows the peripheral surface of each leg 12, 14, 16 to contact the peripheral surface of the measurement object 3. Therefore, each leg 12 , 14 and 16 may be the same or different from each other.
[0031] Further, the first link plate 5 is provided with a slit-shaped first slide groove 17 extending in the radial direction. Similarly, the second link plate 6 is provided with a slit-shaped second sliding groove 18 extending in the radial direction, and the third link plate 8 is provided with a slit-shaped third sliding groove 19 extending in the radial direction. is perforated.
[0032] The center of the first sliding groove 17 is positioned on the perpendicular bisector of the straight line (the chord of the fan-shaped arc) connecting both peripheral ends of the first link plate 5, and the first sliding groove 17 The longitudinal centerline of the is coincident with the perpendicular bisector. Similarly, the center of the second sliding groove 18 is located on the perpendicular bisector of the straight line (the chord of the fan-shaped arc) connecting both peripheral ends of the second link plate 6, The longitudinally extending centerline of the groove 18 coincides with the perpendicular bisector. Furthermore, the center of the third sliding groove 19 is positioned on the perpendicular bisector of the straight line (the chord of the arc of the fan shape) connecting both peripheral ends of the third link plate 8, The longitudinal centerline of groove 19 coincides with the perpendicular bisector.
[0033] The reference point designating device 1 has a disk-shaped bottom plate 21 (described later) and a cylindrical holder 22 projecting upward from the center of the bottom plate. In the holder 22, a writing tool or a scribe needle as a transfer tool for marking the center point on the measurement object 3, or the prism 4 as a retroreflector as shown in FIG. there is The height from the lower surface of the bottom plate 21 to the optical center of the prism 4 is known, and the optical center is positioned on the center line of the holder 22. As shown in FIG. Also, the bottom plate 21, the holder 22, and the transfer tool or the retroreflector constitute a pointing tool.
[0034] The holder 22 is slidably inserted across the first sliding groove 17, the second sliding groove 18, and the third sliding groove 19. As shown in FIG. At this time, the center of the holder 22 is located at the intersection of the center line of the first slide groove 17, the center line of the second slide groove 18, and the center line of the third slide groove 19. ing. Therefore, the first link plate 5, the second link plate 6, and the third link plate 8 rotate relative to each other as the holder 22 slides in the slide grooves 17-19.
[0035] The perpendicular bisector of the line connecting the first connection point 7 and the second connection point 9 coincides with the center line of the second sliding groove 18, and the first connection point 7 and the second connection point 7 The connecting point 9 is an arbitrary point on the center line of the second sliding groove 18, that is, the same point centered on the holder 22 (the prism 4) slid to an arbitrary position of the second sliding groove 18. located on a circle.
[0036] Also, a perpendicular bisector of a straight line connecting the center of the first leg 12 and the center of the second leg 14 and the center of the second leg 14 and the center of the third leg 16 are connected. The positions of the first leg 12, the second leg 14 and the third leg 16 are set so that the intersection of the perpendicular bisectors of the straight lines coincides with the center of the holder 22. As shown in FIG. That is, the respective centers of the first leg portion 12, the second leg portion 14, and the third leg portion 16 are located on the same circumference with the holder 22 as the center.
[0037] Therefore, a circle passing through the first connecting point 7 and the second connecting point 9, a circle passing through the center of the first leg 12, the center of the second leg 14, and the center of the third leg 16 are concentric circles centered on the holder 22 (the prism 4).
[0038] The holder 22 can slide along the first sliding groove 17, the second sliding groove 18, and the third sliding groove 19 at the same time. For example, as shown in FIG. 2(B), when the holder 22 is slid along the second sliding groove 18 to the outer peripheral side, the first link plate 5 moves the first connecting point 7. It rotates counterclockwise about the center, and the holder 22 slides along the first slide groove 17 to the outer peripheral side by the distance as in the case of the second slide groove 18 . In addition, the third link plate 8 rotates clockwise about the second connection point 9, and the holder 22 moves along the third slide groove 19 by a distance that is the case with the second slide groove 18. and slide to the outer peripheral side.
[0039] As shown in FIG. 2(A), when the holder 22 is slid toward the center along the second slide groove 18, the first link plate 5 and the first link plate 5 move in the opposite direction to the above. The second link plate 6 rotates and the holder 22 slides.
[0040] The second slide groove 18 is located on the perpendicular bisector of the first connection point 7 and the second connection point 9, and the holder 22 slides along the perpendicular bisector. Therefore, even if the holder 22 is slid, the distance from the first connecting point 7 to the holder 22 and the distance from the second connecting point 9 to the holder 22 are always the same.
[0041] A circle passing through the respective centers of the first leg portion 12, the second leg portion 14, and the third leg portion 16 has the holder 22 as its center and is connected to the first connection point 7 and the second connection point. Since it is in a concentric relationship with the circle passing through 9, even when the holder 22 is slid, the distance from the holder 22 to the first leg 12 and the distance from the holder 22 to the second leg 14 , the distance from the holder 22 to the third leg 16 is always the same. Similarly, the relationship between the first connection point 7 and the second leg 14 and the relationship between the second connection point 9 and the third leg 16 do not change.
[0042] In the above description, the holder 22 sliding in the second slide groove 18 has been described. On the other hand, the holder 22 is located at the intersection of the center line of the first slide groove 17, the center line of the second slide groove 18, and the center line of the third slide groove 19. As shown in FIG. Therefore, both when the holder 22 slides in the first slide groove 17 and when the holder 22 slides in the third slide groove 19, the holder 22 slides in the second slide groove. Same as when 18 is slid.
[0043] As described above, even if the holder 22 is moved to any position in each of the sliding grooves 17 to 19, the center of the holder 22 (the center of the prism 4) is aligned with the first leg 12 and the second leg 12. It is located on the intersection of the perpendicular bisector of the straight line connecting the legs 14 and the perpendicular bisector of the straight line connecting the second leg 14 and the third leg 16 . That is, the center of the holder 22 is positioned at the center of a circle passing through the center of the first leg 12, the center of the second leg 14, and the center of the third leg 16. As shown in FIG.
[0044] Therefore, the holder 22 is slid so that the legs 12, 14, and 16 are in contact with the peripheral surface of the cylindrical measuring object 3 while the lower surface of the bottom plate 21 is in contact with the surface of the measuring object 3. When moved, each link plate 5, 6, 8 is rotated via said first connection point 7 and said second connection point 9. As shown in FIG.
[0045] Since the circle passing through the points of contact between each leg 12, 14, 16 and the measurement object 3 and the circle passing through the center of each leg 12, 14, 16 are concentric circles, each leg 12, 14, 16 is in contact with the peripheral surface of the object 3 to be measured, the holder 22 can be moved onto the center of the object 3 to be measured.
[0046] As described above, the reference point specifying device 1 can change the size of the circle passing through the three legs 12, 14, 16 by sliding the holder 22. As shown in FIG. Moreover, even when the size of the circle is changed, the holder 22 and the prism 4 provided in the holder 22 are always positioned at the center of the circle.
[0047] Therefore, regardless of the diameter of the object 3 to be measured, the reference point designating device 1 is installed on the object 3 to be measured, and each link plate is arranged so that the legs 12, 14, and 16 are in contact with the peripheral surface of the object 3 to be measured. Only by rotating 5, 6, 8, the holder 22 can be automatically moved onto the center of the measurement object 3, and the reference point can be specified.
[0048] Further, by measuring the prism 4 attached to the holder 22 with the surveying device 2, the three-dimensional coordinates of the center of the measurement object 3 can be determined based on the measurement result of the prism 4 and the known height of the prism 4. can be asked for.
[0049] Therefore, there is no need to measure the dimensions of the object 3 to be measured in order to specify the reference point. Since only one step is required, the working time can be shortened, and the working labor can be reduced.
[0050] In addition, in the first embodiment, the holder 22 is manually slid, but between the first link plate 5 and the second link plate 6 and between the second link plate 6 and the third link plate 6 An urging means such as a spring may be provided between the link plate 8 and each. The urging means urges the legs 12, 14, 16 in such a way that the circles inscribed in the legs 12, 14, 16 become smaller. The parts 12, 14, 16 can be automatically brought into contact with the peripheral surface of the measurement object 3, and workability can be further improved.
[0051] Also, the positions at which the legs 12, 14 and 16 are provided are not limited to the arrangement of the first embodiment. FIG. 3 shows a first modification of the first embodiment. In this modified example, the position of the third leg portion 16a is different from that of the third leg portion 16 in the first embodiment.
[0052] In the modification of the first embodiment, the third projecting piece 15a radially protrudes from the peripheral end portion on the side different from the second connection point 9, and the third leg portion 16a is attached to the third projecting piece 15. is provided. Also in the modification of the first embodiment, the perpendicular bisector of the straight line connecting the center of the first leg 12 and the center of the second leg 14 and the second leg 14 The center of the holder 22 is positioned on the intersection of the vertical bisector of the straight line connecting the third leg portions 16a.
[0053] Therefore, by simply rotating each link plate 5, 6, 8 so that each leg 12, 14, 16a is in contact with the peripheral surface of the measurement object 3, the holder 22 and the prism 4 provided in the holder 22 can be moved. can be moved onto the center of the object 3 to be measured.
[0054] Next, a second embodiment of the present invention will be described with reference to FIG. In FIG. 4, the same reference numerals are given to the same parts as those in FIG. 3, and the explanation thereof will be omitted.
[0055] The reference point specifying device 1 (see FIG. 2) in the first embodiment is configured to cover the object 3 to be measured from above. Therefore, the legs 12, 14, and 16 cannot be viewed from above, and it is necessary to go around and check whether the legs 12, 14, and 16 are actually in contact with the peripheral surface of the measurement object 3. there were.
[0056] In the reference point specifying device 23 of the second embodiment, the shape of the third link plate 24 located on the back side as viewed from the operator is different from the third link plate 8 of the first embodiment. Other configurations are the same as those of the first embodiment.
[0057] The third link plate 24 has an extension portion 25 extending outward. In FIG. 4, the extending portion 25 is formed leaving a part of the outer circumference of the third link plate 24, but the extending portion 25 is formed over the entire outer circumference of the third link plate 24. may have been
[0058] A third leg portion 26 projecting downward is provided at a peripheral end portion of the extension portion 25 on a side different from the second connection point 9 . Furthermore, in the center side of the extension portion 25 with respect to the third leg portion 26, an arc-shaped slit 27 extends from the peripheral end of the side on which the third leg portion 26 is provided toward the second connection point 9. is formed.
[0059] The width of the slit 27 is such that when the reference point designating device 23 is attached to the measurement object 3, both the peripheral edge of the measurement object 3 and the third leg 26 are visible. there is Also, the length of the slit 27 is appropriately set to a length that allows the third leg portion 26 to be easily visually recognized regardless of the operator's viewpoint.
[0060] In the second embodiment, the peripheral edge of the third leg portion 26 and the measurement object 3 can be visually recognized from above through the slit 27 . Therefore, when the reference point specifying device 23 is attached to the object 3 to be measured, it is possible to visually confirm whether or not the third leg portion 26 is in contact with the peripheral surface of the object 3 to be measured. Therefore, it is not necessary to turn around to check whether or not the third leg 26 is in contact with the object 3 to be measured, and workability can be improved.
[0061] In the second embodiment, the slit 27 is formed in the extending portion 25, but instead of the slit 27, a viewing window made of transparent resin may be provided.
[0062] Next, a third embodiment of the present invention will be described with reference to FIGS. 5(A), 5(B), 5(C) and 5(D). In FIG. 5, the same reference numerals are given to the same parts as those in FIG. 2, and the explanation thereof will be omitted.
[0063] 5(A) and 5(B) are partial plan views showing the first link plate 28 and the first projecting piece 29 in the third embodiment, and FIGS. 5(C) and 5(D) are 5(A) and 5(B), respectively. FIG. The second link plate (not shown) and the second projecting piece (not shown), the third link plate (not shown) and the third projecting piece (not shown) are connected to the first link plate 28 and Since they have the same structure as the first projecting piece 29, the first link plate 28 and the first projecting piece 29 will be described below.
[0064] The first protruding piece 29 has a slit 31 open to the outer peripheral side, and is provided with a linear fixed marker 32 provided in a direction perpendicular to the slit 31 across the slit 31 . A slit 34 continuous with the slit 31 is formed in the first leg portion 33 projecting downward from the lower surface of the first projecting piece 29 .
[0065] A tilting portion 35 is inserted through the slits 31 and 34 . The tilting portion 35 has a shaft portion 36 extending in the vertical direction and a projecting portion 37 projecting from the upper end of the shaft portion 36 toward the outer peripheral side. The tilting portion 35 is configured to be tiltable about a fulcrum 38 in the contact direction with the object 3 to be measured within the slits 31 and 34 . A rectilinear movable marker 39 is provided in the direction of the arrow.
[0066] Further, the tilting portion 35 is urged by an urging means such as a spring (not shown) so that the lower end of the shaft portion rotates in a direction (counterclockwise in FIG. 5(C)) to approach the object 3 to be measured. ing. Further, a rotation stopper 41 is provided at a predetermined position of the first leg portion 33, and the rotation stopper 41 prevents the tilting portion 35 from rotating beyond a predetermined inclination.
[0067] When the rotation of the tilting portion 35 is restricted by the detent 41, as shown in FIGS. It protrudes from the peripheral surface toward the center side (the holder 22 side). At this time, the positions of the fixed marker 32 and the movable marker 39 are out of alignment.
[0068] Further, as shown in FIG. 5(B), when the first leg portion 33 contacts the peripheral surface of the measurement object 3, the shaft portion 36 is pressed by the measurement object 3, and the shaft portion The tilting portion 35 tilts such that the lower end of the tilting portion 36 is flush with the peripheral surface of the first leg portion 33 . At this time, the positions of the fixed marker 32 and the movable marker 39 match and form a straight line.
[0069] As described above, in the third embodiment, the tilting portion 35 that tilts in the slit 31 formed in the first projecting piece 29 is provided, and the first leg portion 33 moves along the peripheral surface of the object 3 to be measured. , the position of the fixed marker 32 on the first projecting piece 29 and the position of the movable marker 39 on the projecting portion 37 are aligned.
[0070] Therefore, contact between the first leg 33 and the object 3 to be measured can be achieved by simply checking the positions of the markers 32 and 39 from above, so that the first leg 33 and the object 3 to be measured are in contact. There is no need to directly check whether the
[0071] Although the first projecting piece 29 has been described above, the second projecting piece and the third projecting piece have the same configuration. The contact state with the measurement object 3 can be confirmed.
[0072] In addition, in the third embodiment, the tilting portion 35 that tilts within the slits 31 and 34 is provided. A sensor of formula may be provided.
[0073] Next, a fourth embodiment of the present invention will be described with reference to FIGS. 6(A) and 6(B). 6(A), 6(B), 2(A), and 2(B) are denoted by the same reference numerals, and description thereof will be omitted.
[0074] The reference point designating device 42 in the fourth embodiment shows the case where the reference point designating device 42 is applied to the tubular measuring object 3. FIG. A first projecting piece 44 is provided so as to project outward (opposite to the center side) from the first leg portion 43, a second projecting piece 46 is provided so as to project outward from the second leg portion 45, and Three projecting pieces 48 are provided so as to protrude outward from the third leg portion 47 . That is, the first projecting piece 44 has a plate-like first mounting portion 44a projecting outward from the first leg portion 43, and the second projecting piece 46 is positioned further than the second leg portion 45. The third projecting piece 48 has a plate-shaped third mounting portion 48a that projects further outward than the third leg portion 47. As shown in FIG. In addition, it is preferable to provide height adjusting members such as spacers on the lower surfaces of the first mounting portion 44a and the second mounting portion 46a so that they are flush with the lower surface of the third mounting portion 48a. .
[0075] In addition, the reference point designating device 42 is arranged so that the holder 22 slides in each of the sliding grooves 17 to 19 toward the center of the fan shape of each of the link plates 5, 6, 8, that is, each of the legs 43, 45, 47. Each link plate 5, 6, 8 is biased by a biasing means such as a spring so that the link plates 5, 6, 8 are rotated in the direction in which the circle passing through is expanded.
[0076] Therefore, when the object 3 to be measured is tubular, the leg portions 43, 45, and 47 are brought into contact with the inner peripheral surface of the object 3 to be measured, and the mounting portions 44a, 46a, and 48a are placed on the upper surface of the object 3 to be measured. By attaching the reference point specifying device 42 so as to place the reference point specifying device 42, the prism 4 attached to the holder 22 can be automatically moved to the center of the pipe without the reference point specifying device 42 falling. . Also, by measuring the prism 4, the position of the center of the pipe can be measured.
[0077] Next, a fifth embodiment of the present invention will be described with reference to FIGS. 7(A), 7(B) and 7(C). 7(A), 7(B), 7(C), 2(A), and 2(B) are denoted by the same reference numerals, and the description thereof is omitted. .
[0078] In the reference point specifying device 49 of the fifth embodiment, a pointing tool is composed of the bottom plate 21, the holder 22, the offset bar 51, and the prism 4 as the reference measurement object. The offset bar 51 is provided on the holder 22 at its proximal end. The offset bar 51 has a length extending from the center of the reference point designating device 49 beyond the circumference of the reference point designating device 49 . The offset bar 51 has a slit-shaped guide groove 52, and the prism 4 is provided in the guide groove 52 so as to be slidable and fixed at an arbitrary position.
[0079] 7(A), the offset bar 51 is arranged so that the optical center of the prism 4 and the holder 22 are aligned when the prism 4 is positioned at the base end portion (center position) of the guide groove 52. , and are rotatable around the holder 22 . When the prism 4 is positioned at the base end of the guide groove 52, even if the offset bar 51 is rotated, the position of the prism 4 does not change.
[0080] Further, the guide groove 52 is formed with a scale (not shown), and the offset bar 51 is provided with a rotation angle detector (not shown) such as an encoder. Therefore, the amount of movement of the prism 4 from the center and the rotation angle of the offset bar 51 can be detected.
[0081] In the fifth embodiment, as shown in FIG. 7(A), first, the reference point specifying device 49 is attached to the measurement object 3, the prism 4 is moved to the center position, and then the prism Measure 4. What is measured at this time is the center of the measurement object 3, that is, the reference point.
[0082] Next, as shown in FIG. 7B, the prism 4 is moved along the guide groove 52 by a desired offset amount. Further, as shown in FIG. 7(C), the offset bar 51 is rotated by a desired rotation angle to specify the offset point.
[0083] By measuring the prism 4 in this state, the three-dimensional coordinates of an offset point offset by a desired amount in a desired direction from the center (reference point) of the measurement object 3 can be obtained.
[0084] Next, a sixth embodiment of the present invention will be described with reference to FIGS. 8(A) and 8(B). In FIGS. 8(A) and 8(B), the same reference numerals are given to the same parts as those in FIG. 2, and the explanation thereof will be omitted.
[0085] In the sixth embodiment, the reference point designating device 53 has two fan-shaped link plates with a central angle of 90° and the same radius.
[0086] The first link plate 54 and the second link plate 55 are rotatably connected in a superimposed state at a first connection point 56 located at the end of the outer periphery.
[0087] As shown in FIGS. 8(A) and 8(B), the peripheral end of the first link plate 54 on the opposite side of the first connection point 56 protrudes radially from a fan-shaped arc. A first projecting piece 57 is provided, and the first projecting piece 57 is provided with a cylindrical first leg portion 58 projecting downward. A second projecting piece 59 projecting radially from a fan-shaped arc is provided at the peripheral end of the first link plate 54 on the first connection point 56 side. A columnar second leg portion 61 protruding downward is provided. Further, a third projecting piece 62 projecting radially from a fan-shaped arc is provided at the peripheral end of the second link plate 55 opposite to the first connection point 56. The third projecting piece 62 A cylindrical third leg portion 63 protrudes downward.
[0088] Similar to the other embodiments, the first link plate 54 and the second link plate 55 are provided with a slit-shaped first sliding groove 64 and a second sliding groove 65, respectively. The center line extending in the longitudinal direction of the first sliding groove 64 is located on the perpendicular bisector of the straight line (the chord of the fan-shaped arc) connecting both peripheral ends of the first link plate 54, The center line extending in the longitudinal direction of the sliding groove 65 is positioned on the perpendicular bisector of the straight line (the chord of the fan-shaped arc) connecting both peripheral ends of the second link plate 55 .
[0089] At the intersection of the center line of the first sliding groove 64 and the center line of the second sliding groove 65, the holder 22 and the prism 4 provided in the holder are provided. Also, a perpendicular bisector of a straight line connecting the center of the first leg 58 and the center of the second leg 61 and the center of the second leg 61 and the center of the third leg 63 are connected. The positions of the legs 58 , 61 , 63 are set so that the intersection of the perpendicular bisectors of the straight lines coincides with the center of the prism 4 . That is, the centers of the legs 58, 61, 63 are located on the same circumference with the prism 4 as the center.
[0090] Also in the sixth embodiment, the reference point designating device 53 can change the size of the circle passing through the legs 58, 61, 63 by sliding the holder 22, and the size of the circle can be changed. Even if changed, the prism 4 is always located in the center of the circle.
[0091] Therefore, regardless of the diameter of the object 3 to be measured (see FIG. 2), by simply rotating the link plates 54 and 55 so that the legs 58, 61 and 63 are in contact with the peripheral surface of the object 3 to be measured, the prism 4 can be automatically moved onto the center of the object 3 to be measured.
[0092] Next, a seventh embodiment of the present invention will be described with reference to FIG. In FIG. 9, the same reference numerals are given to the same parts as in FIG. 2, and the explanation thereof will be omitted.
[0093] In a seventh embodiment, the reference point designator 66 has four fan-shaped link plates with a central angle of 45° and the same radius.
[0094] The first link plate 67 and the second link plate 68 are rotatably connected in an overlapping state at a first connection point 69 located at the end of the outer periphery. Also, the second link plate 68 and the third link plate 71 are overlapped at a second connection point 72 located on the opposite peripheral end of the second link plate 68 from the first connection point 69. It is rotatably connected in a closed state. Furthermore, the third link plate 71 and the fourth link plate 73 overlap each other at a third connection point 74 located on the peripheral end of the third link plate 71 opposite to the second connection point 72. It is rotatably connected in a closed state.
[0095] In the reference point specifying device 66, the link plates 67, 68, 71, 73 are connected so as not to interfere with each other's overlap. For example, as shown in FIG. 9, the second link plate 68 is positioned below the first link plate 67, the third link plate 71 is positioned below the second link plate 68, and the third link plate 71 is positioned below the second link plate 68. The fourth link plate 73 is positioned below the three link plate 71 .
[0096] A first projecting piece 75 projecting radially from a fan-shaped arc is provided on the peripheral end of the first link plate 67 opposite to the first connection point 69. The first projecting piece 75 has a A columnar first leg portion 76 protruding downward is provided. A second projecting piece 77 projecting radially from a fan-shaped arc is provided at the peripheral end portion of the third link plate 71 on the side of the second connecting point 72. The second projecting piece 77 has a A cylindrical second leg 78 is provided that protrudes downward. Further, a third projecting piece 79 projecting radially from a fan-shaped arc is provided at the peripheral end of the fourth link plate 73 opposite to the third connecting point 74. The third projecting piece 79 is provided with a cylindrical third leg portion 81 protruding downward.
[0097] As in the other embodiments, a slit-shaped first sliding groove 82 is formed in the first link plate 67, a slit-shaped second sliding groove 83 is formed in the second link plate 68, and the A slit-shaped third slide groove 84 is formed in the third link plate 71 , and a slit-shaped fourth slide groove 85 is formed in the fourth link plate 73 .
[0098] The longitudinal centerlines of the respective slide grooves 82-85 are located on the vertical bisectors of the straight lines connecting both peripheral ends of the link plates 67, 68, 71, 73, respectively. Also, the holder 22 and the prism 4 (see FIG. 2) are provided at the intersections of the center lines of the sliding grooves 82-85.
[0099] The perpendicular bisector of the straight line connecting the first connection point 69 and the second connection point 72 coincides with the center line of the second slide groove 83, and the second connection point 72 and the second connection point 72 are aligned. The perpendicular bisector of the straight line connecting the three connecting points 74 coincides with the center line of the third sliding groove 84. As shown in FIG. In other words, the connecting points 69, 72, 74 are positioned on the same circumference with the prism 4 as the center regardless of the position of the prism 4. As shown in FIG.
[0100] Also, a perpendicular bisector of a straight line connecting the center of the first leg 76 and the center of the second leg 78 and the center of the second leg 78 and the center of the third leg 81 are connected. The positions of the legs 76, 78, 81 are set so that the intersection of the straight line with the perpendicular bisector coincides with the center of the prism. That is, the centers of the legs 76, 78, and 81 are positioned on the same circumference with the prism 4 as the center, and the relationship between the circle and the concentric circle centered on the prism 4 and passing through the connection points 69, 72, and 74. becomes.
[0101] Also in the seventh embodiment, the reference point designating device 66 can change the size of the circle passing through each of the legs 76, 78, 81 by sliding the holder 22. Even if changed, the prism 4 is always located in the center of the circle.
[0102] Therefore, the link plates 67, 68, 71 and 73 are simply rotated so that the legs 76, 78 and 81 are in contact with the peripheral surface of the measurement object 3 (see FIG. 2) regardless of the diameter of the measurement object 3 (see FIG. 2). , the prism can be automatically moved onto the center of the object 3 to be measured.
[0103] In the sixth embodiment, two link plates are used, and in the seventh embodiment, four link plates are used to constitute the reference point specifying device, but five or more link plates are used. A reference point specifying device may be configured by:
[0104] Further, in the first to seventh embodiments, the positions of each leg and each connecting point are set so as to have a concentric relationship with the prism 4 as the center. is not limited to For example, each leg may be provided so as to be concentric with each connection point, and each leg and each connection point may be positioned on the same circumference with the prism 4 as the center.
[0105] Furthermore, in the first to seventh embodiments, the reference point designating device is provided with three legs. It goes without saying that more than four legs may be provided as long as they are positioned at the
[0106] Next, an eighth embodiment of the present invention will be described with reference to FIGS. 10(A) and 10(B). In FIGS. 10(A) and 10(B), the same reference numerals are given to the same parts as those in FIG. 2, and the explanation thereof will be omitted.
[0107] In the eighth embodiment, the reference point designating device 86 has two T-shaped link plates. The first link plate 87 has a first shaft portion 88 and a first sliding portion 89 perpendicular to the first shaft portion 88, and the second link plate 91 has a second shaft portion 92 and the second shaft portion. It has a second slide 93 perpendicular to 92 . The shaft portions 88, 92 and the sliding portions 89, 93 have substantially straight outer shapes.
[0108] The first link plate 87 and the second link plate 91 are rotatably overlapped at a first connection point 94 located at one end of the first shaft portion 88 and the second shaft portion 92. connected to
[0109] As shown in FIGS. 10(A) and 10(B), the end of the first shaft portion 88 opposite to the first connection point 94 has a columnar first leg projecting downward. 95 is provided. A second leg portion 96 projecting downward is provided concentrically with the first connection point 94 at the end portion of the first shaft portion 88 and the second shaft portion 92 on the first connection point 94 side. ing. Further, the end of the second shaft portion 92 opposite to the first connection point 94 is provided with a columnar third leg portion 97 protruding downward. The first leg portion 95, the second leg portion 96, and the third leg portion 97 are cylinders having the same radius and the same height.
[0110] A slit-shaped first sliding groove 98 is formed in the first sliding portion 89 , and a slit-shaped second sliding groove 99 is formed in the second sliding portion 93 . A center line extending in the longitudinal direction of the first sliding groove 98 is located on the perpendicular bisector of a straight line connecting the center of the first leg portion 95 and the center of the second leg portion 96. The center line extending in the longitudinal direction of the second slide groove 99 is located on the perpendicular bisector of the straight line connecting the center of the second leg portion 96 and the center of the third leg portion 97 .
[0111] At the intersection of the center line of the first sliding groove 98 and the center line of the second sliding groove 99, a holder 22 (see FIG. 2) and a prism 4 provided in the holder 22 are provided. . That is, the prism 4 is formed by perpendicularly bisecting a straight line connecting the center of the first leg 95 and the center of the second leg 96, the center of the second leg 96 and the third leg. It is located on the intersection with the perpendicular bisector of the straight line connecting the center of 97.
[0112] Therefore, even if the prism 4 moves along the first sliding groove 98 and the second sliding groove 99, the centers of the legs 95 to 97 are always centered on the prism 4 (centered on the intersection point). ) on the same circumference.
[0113] Also in the eighth embodiment, the reference point specifying device 86 can change the size of the circle passing through the legs 95 to 97 by sliding the prism 4 (the holder 22). Even if the size is changed, they are positioned on the same circumference with the prism 4 as the center.
[0114] Therefore, regardless of the diameter of the object 3 to be measured, the prism 4 can be automatically moved to the object 3 by simply rotating the link plates 87 and 91 so that the legs 95 to 97 are in contact with the peripheral surface of the object 3 to be measured. It can be moved to the center of 3.
[0115] FIG. 11 shows a first modification of the eighth embodiment. In the first modification, the first link plate 87 and the second link plate 91 are not connected via the first shaft portion 88 and the second shaft portion 92 .
[0116] In addition, the first leg portion 95 and the second leg portion 96 projecting downward are provided at both ends of the first shaft portion 88, and both ends of the second shaft portion 92 project downward. The third leg 97 and the fourth leg 101 are provided.
[0117] In the first modification, the first leg portion 95 and the second leg portion 96 are in contact with the peripheral surface of the measurement object 3, and the third leg portion 97 and the fourth leg portion 101 are also The holder 22 is slid in the first sliding groove 98 and the second sliding groove 99 so as to come into contact with the peripheral surface of the object 3 to be measured.
[0118] At this time, the circle passing through the centers of the legs 95, 96, 97, and 101 and the measurement object 3 are in a concentric relationship, and the straight line connecting the center of the first leg 95 and the center of the second leg 96 is formed. The holder 22 and the prism 4 are positioned on the intersection of the perpendicular bisector and the straight perpendicular bisector connecting the center of the third leg 97 and the center of the fourth leg 101 . That is, the prism 4 is positioned on the center of the object 3 to be measured.
[0119] Therefore, regardless of the diameter of the object 3 to be measured, the prism 4 can be moved by simply sliding the link plates 87, 91 so that the legs 95, 96, 97, 101 come into contact with the peripheral surface of the object 3 to be measured. It can be automatically moved to the center of the object 3 to be measured.
[0120] FIG. 12 shows a second modification of the eighth embodiment. In the second modified example, the extendable portion 102 is attached to the holder 22 and the prism 4 is attached to the extendable portion 102 .
[0121] The expandable section 102 is expandable in the vertical direction, that is, in a direction perpendicular to the surface of the object 3 to be measured. Further, the expansion / contraction portion 102 is provided with a scale or the like so that the expansion / contraction amount can be detected.
[0122] Therefore, the height from the bottom plate 21 to the optical center of the prism 4 can be known, and the three-dimensional coordinates of any height from the surface of the measurement object 3 can be obtained.
[0123] Needless to say, the expandable portion 102 and the prism 4 attached to the expandable portion 102 in the second modified example are also applicable to other embodiments.
[0124] Next, a ninth embodiment of the present invention will be described with reference to FIG. In FIG. 13, the same symbols are given to the same parts as those in FIGS. 10(A) and 10(B), and the description thereof is omitted.
[0125] In the ninth embodiment, the reference point specifying device 103 has three T-shaped link plates. The first link plate 104 has a first shaft portion 105 and a first sliding portion 106, the second link plate 107 has a second shaft portion 108 and a second sliding portion 109, and has a third Link plate 111 has third shaft portion 112 and third sliding portion 113 .
[0126] The first link plate 104 and the second link plate 107 are rotatably overlapped at a first connection point 114 located at one end of the first shaft portion 105 and the second shaft portion 108. connected to The second link plate 107 and the third link plate 111 are overlapped at a second connection point 115 located at the other end of the second shaft portion 108 and one end of the third shaft portion 112. rotatably connected. The link plates 104, 107, 111 are arranged so as not to interfere with each other's rotation. For example, the first link plate 104 is connected to the upper surface of the second link plate 107 and the third link plate 111 is connected to the lower surface of the second link plate 107 .
[0127] A cylindrical first leg 116 protruding downward is provided at the other end of the first shaft 105 . Further, a columnar second leg 117 protruding downward is provided concentrically with the first connection point 114 at the end of the second shaft 108 on the first connection point 114 side. Furthermore, a cylindrical third leg 118 projecting downward is provided at the end of the third shaft 112 opposite to the second connection point 115 .
[0128] A slit-shaped first sliding groove 121 is formed in the first sliding portion 106, and a slit-shaped second sliding groove 122 is formed in the second sliding portion 109. A slit-shaped third sliding groove 123 is formed in the moving portion 113 .
[0129] The center line extending in the longitudinal direction of the first slide groove 121 is the perpendicular second straight line connecting the center of the first leg portion 116 and the center of the second leg portion 117 (the first connection point 114). A center line located on the segment line and extending in the longitudinal direction of the second slide groove 122 connects the center of the second leg portion 117 (the first connection point 114) and the center of the second connection point 115. The center line of the third slide groove 123, which is located on the perpendicular bisector of the straight line and extends in the longitudinal direction, is the straight line connecting the center of the second connection point 115 and the center of the third leg portion 118. Located on the perpendicular bisector.
[0130] Also, the holder 22 and the holder 22 are attached to the intersection of the center line of the first sliding groove 121, the center line of the second sliding groove 122, and the center line of the third sliding groove 123. A prism 4 (see FIG. 10) is provided. That is, the prism 4 has a perpendicular bisector of a straight line connecting the center of the first leg 116 and the center of the second leg 117 (the first connection point 114), and the second leg The perpendicular bisector of the straight line connecting the center of 117 (the first connecting point 114) and the center of the second connecting point 115, the center of the second connecting point 115 and the center of the third leg 118 It is located on the intersection with the perpendicular bisector of the straight line connecting
[0131] Therefore, even if the prism 4 moves along the sliding grooves 121-123, the prism 4 is always positioned at the center of the circle passing through the centers of the legs 116-118 and the connecting points 114,115.
[0132] In the ninth embodiment as well, the reference point specifying device 103 changes the size of the circle passing through the legs 116 to 118 and the connecting points 114 and 115 by sliding the prism 4. , are positioned on the same circumference with the prism 4 as the center.
[0133] Therefore, regardless of the diameter of the object 3 to be measured, the prism 4 can be automatically moved to the object 3 by simply rotating the link plates 104, 107, and 111 so that the legs 116 to 118 come into contact with the peripheral surface of the object 3 to be measured. can be moved to the center of
[0134] In the ninth embodiment, the reference point designating device 103 is provided with three legs. good.
[0135] FIG. 14 shows a modification of the ninth embodiment. In this modified example, the second link plate 124 does not have the second sliding portion, and is composed only of the second shaft portion 125 . A columnar fourth leg portion 126 protruding downward is provided concentrically with the second connection point 115 at the end of the third link plate 111 on the second connection point 115 side.
[0136] In the above modification, the first leg 116 and the second leg 117 are in contact with the peripheral surface of the measurement object 3, and the third leg 118 and the fourth leg 126 are also in contact with the measurement object 3. The holder is slid within the first sliding groove 121 and the third sliding groove 123 so as to come into contact with the peripheral surface of the object 3 .
[0137] At this time, the circle passing through the centers of the legs 116, 117, 118, and 126 and the object 3 to be measured are in a concentric relationship, and the straight line connecting the center of the first leg 116 and the center of the second leg 117 is vertically bisected. The holder and the prism 4 are positioned on the intersection of the line and the perpendicular bisector of the straight line connecting the center of the third leg 118 and the center of the fourth leg 126 . That is, the prism is positioned on the center of the object 3 to be measured.
[0138] Therefore, regardless of the diameter of the object to be measured, the prism 4 is automatically positioned on the center of the object to be measured 3 simply by rotating the link plates 104, 107, 111 so that the legs 116, 117, 118, 126 come into contact with the peripheral surface of the object to be measured. can be moved to
[0139] Next, a tenth embodiment of the present invention will be described with reference to FIG. 15(A). In FIG. 15(A), the same components as those in FIG. 2 are denoted by the same reference numerals, and the description thereof is omitted. Further, FIG. 15(A) explains the first link plate 5. As shown in FIG.
[0140] In particular, when the reference point designating device 130 is enlarged, the first link plate 5 may bend downward due to the weight of the first link plate 5 and the weight of the first leg portion 12 . When the first link plate 5 is bent, the contact position between the object 3 to be measured and the first leg portion 12 changes, so there is a possibility that the center of the object 3 to be measured and the pointing tool may be misaligned. be.
[0141] In the tenth embodiment, a height adjusting member 128 such as a spacer is provided around the first leg 12 or adjacent to the first leg 12 . The height adjusting member 128 has, for example, a cylindrical shape, and the lower surface of the height adjusting member 128 is configured to be flush with the lower surface of the bottom plate 21 (indicator). That is, when the reference point designating device 130 is attached to the object 3 to be measured, the lower surface of the pointing tool and the lower surface of the height adjusting member 128 come into contact with the upper surface of the object 3 to be measured on the same plane. .
[0142] By attaching the reference point designating device 130 to the object 3 to be measured so that the lower surface of the height adjustment member 128 contacts the upper surface of the object 3 to be measured, the first link plate 5 is not bent and the first The peripheral surface of the leg portion 12 can be brought into contact with the peripheral surface of the object 3 to be measured. Therefore, it is possible to prevent the positional deviation between the center of the object 3 to be measured and the pointing tool (the bottom plate 21), and to improve the measurement accuracy of the center of the object 3 to be measured.
[0143] Although the first link plate 5 has been described above, the second link plate 6 and the third link plate 8, like the first link plate 5, also have height adjusting members for preventing bending. be provided.
[0144] FIG. 15(B) shows a modification of the tenth embodiment. In the tenth embodiment, the height adjusting member 128 has a cylindrical shape. may be mistaken for contact between the peripheral surface of the first leg 12 and the peripheral surface of the object 3 to be measured.
[0145] In a modification of the tenth embodiment, for example, the height adjusting member 129 has a truncated cone shape whose diameter decreases downward. That is, the periphery of the height adjusting member 129 forms a slope-shaped guide portion 129a whose thickness gradually increases from the outer peripheral side toward the center.
[0146] When the circumference of the height adjustment member 129, that is, the guide portion 129a contacts the peripheral edge (corner) of the measurement object 3, the corner of the measurement object 3 slides on the guide portion 129a and guides the object. Therefore, the movement (rotation) of the first link plate 5 is not hindered until the peripheral surface of the first leg portion 12 and the peripheral surface of the measurement object 3 come into contact with each other. Therefore, the contact between the peripheral surface of the height adjusting member 129 and the peripheral surface of the object 3 to be measured is prevented from being mistaken for the contact between the peripheral surface of the first leg portion 12 and the peripheral surface of the object 3 to be measured. It is possible to improve the installation workability of the reference point designating device 130 and improve the measurement accuracy of the center of the measurement object 3 .
[0147] Incidentally, as shown in FIG. 15(C), a concave portion 131 is formed on the back surface of the first projecting piece 11, and the concave portion 131 is provided with the center of the first leg portion 12 and the center of the indicator (the bottom plate 21). A height adjustment member 132 having a slope-shaped guide portion 132a formed only in a direction parallel to a straight line connecting the two may be provided. By providing the height adjusting member 132 in the concave portion 131, the object 3 to be measured is reliably brought into contact with the guide portion 132a without sharpening the tip of the guide portion 132a. become easier. Also, as shown in FIG. 15(D), a height adjusting member 133 having a guide portion 133a having a curved surface may be used.
[0148] In the tenth embodiment and modification, the case where the first link plate 5 according to the first embodiment is provided with a height adjusting member has been described. Needless to say, a height adjustment member may be provided. [Description of symbols]
[0149] 1 Reference point designator 3 Measurement target 4 prism 5 1st link plate 6 2nd link plate 8 3rd link plate 12 1st leg 14 Second leg 16 3rd leg 17 1st sliding groove 18 Second sliding groove 19 Third sliding groove 22 Holder 128 Height adjustment member 129 height adjustment member
Claims
1. A reference point designation device comprising at least two link plates, sliding grooves formed on each of the link plates, an indicator that is slidable along each sliding groove and is provided at the intersection of the center lines of each sliding groove, and at least three legs that are provided on the same circumference with the indicator at its center, the indicator being located at the intersection of perpendicular bisectors of straight lines connecting the centers of adjacent legs, the legs being able to come into contact with a measurement object by sliding the indicator, and the indicator being configured to designate a reference point on the measurement object with each leg in contact with the measurement object.
2. 2. The reference point designating device according to claim 1, wherein the link plate is fan-shaped with a predetermined central angle, and is rotatably connected to an adjacent link plate via a connection point at one peripheral end, and the center line of the sliding groove is positioned on the perpendicular bisector of a line connecting both peripheral ends of the link plate.
3. 2. The reference point designation device according to claim 1, wherein the link plate is T-shaped and has a shaft portion having a connection point for rotatably connecting with an adjacent link plate, and a sliding portion in which the sliding groove is formed, and the center line of the sliding groove is positioned on the perpendicular bisector of the shaft portion.
4. 4. The reference point designation device according to claim 2, wherein a circle centered on the pointing tool and passing through the connection point and a circle centered on the pointing tool and passing through the leg are configured to be the same or concentric circles.
5. 4. The reference point designating device according to claim 2, wherein the link plate is formed with a slit through which contact between the leg portion and the measurement object can be visually confirmed.
6. 4. A reference point designation device as described in claim 2 or claim 3, which has a tilting section that can tilt in the direction of contact of the leg with the object to be measured, a fixed marker is provided on the link plate, a movable marker is provided on the upper surface of the tilting section, and the lower end of the tilting section is biased so that it protrudes further toward the pointing device than the leg, so that when the object to be measured comes into contact, the lower end of the leg and the tilting section become flush, thereby matching the fixed marker and the movable marker.
7. The reference point designation device of claim 1, wherein the pointing tool comprises a holder, an offset bar rotatably arranged around the holder and having a guide groove, and a reference measurement object slidably arranged along the guide groove, and the reference measurement object is configured to be able to designate an offset point that is offset by a predetermined distance in a predetermined direction from a reference point.
8. 2. The reference point designating device according to claim 1, further comprising biasing means for biasing the pointing tool in a direction that enlarges or reduces a circle that passes through each leg and has the pointing tool as its center.
9. The reference point designating device according to claim 1 , wherein the pointing tool includes a retroreflector or a transfer tool.
10. 10. The reference point designating device according to claim 9, wherein the pointing tool includes a prism attached via an extendable tool that is extendable in the vertical direction.
11. 2. The reference point designating device according to claim 1, wherein height adjusting members are provided adjacent to each leg, and the lower surfaces of the height adjusting members are positioned on the same plane as the lower surface of the pointing tool.
12. 12. The reference point designating device according to claim 11, wherein the height adjusting member has a guide portion whose thickness gradually increases from the center toward the outer periphery.