WO2016132407A1

WO2016132407A1 - Right angle step gauge

Info

Publication number: WO2016132407A1
Application number: PCT/JP2015/005468
Authority: WO
Inventors: 進浅沼
Original assignee: 株式会社浅沼技研
Priority date: 2015-02-18
Filing date: 2015-10-30
Publication date: 2016-08-25
Also published as: JP2016151520A; JP6360448B2

Abstract

Provided is a right angle step gauge that makes it possible to use a single gauge to highly accurately verify the indication error and straightness of each mechanical axis direction of a three-dimensional measurement instrument and verify the perpendicularity between each mechanical axis. The right angle step gauge is provided with a gauge main body 14 in which a roughly rod-shaped first reference member holding part 8 and second reference member holding part 9 configured from parallel upper and lower flat surfaces are joined in a shape that is roughly cross-like from a planar view and have perpendicularly adjacent side surfaces that are joined by crosswise reinforcement ribs 10, 11, 12, 13, and with a plurality of bushings 16 (reference members) that are disposed along the longitudinal directions of the first reference member holding part 8 and second reference member holding part 9 and have inner peripheral surfaces that are reference measurement surfaces that the probe leading end of a three-dimensional measurement instrument comes into contact with. The bushings are disposed so as to be vertically symmetrical with respect to imaginary intermediate planes parallel to and positioned between the upper and lower surfaces of the first reference member holding part and second reference member holding part and make highly accurate measurement using an inverted measurement method possible.

Description

Right angle step gauge

The present invention relates to a right-angle step gauge used for verification of positioning accuracy and straightness in the direction of each machine axis of a three-dimensional measuring machine and verification of perpendicularity between each machine axis.

Conventionally, for measuring the dimensions of mechanical parts such as automobile engines and transmission cases, the tip of a probe (measuring element) is brought into contact with the object set on the measurement table (bed). A three-dimensional measuring machine adapted to perform is used.

The three-dimensional measuring machine has a straight line of each machine axis due to an indication error due to wear of the probe itself, or distortion or wear of a guide member or the like that guides movement of the probe in each machine axis direction (X, Y, Z direction). Since errors in the degree and perpendicularity between the machine axes occur, periodic accuracy inspections are performed using a verification gauge that is a highly accurate reference.

Conventionally, as a gauge for verifying accuracy of such a three-dimensional measuring machine, for example, as described in Patent Document 1, a three-dimensional measuring machine is provided along the longitudinal direction of a square bar-like long gauge body. In this proposal, a plurality of reference holes having a plurality of reference holes penetrating in the vertical direction are proposed.

JP 2012-108100 A

The verification gauge of the conventional three-dimensional measuring machine as described in Patent Document 1 described above can verify the indication error and the straightness of the mechanical axis for each machine axis direction of the three-dimensional measuring machine. Although it is possible, when verifying the perpendicularity between two machine axes, prepare a triangle or quadrangle right angle gauge with two perpendicular sides adjacent to each other as a reference measurement surface, and apply a probe to it. Needed to be measured.

When the probe is applied to one reference measurement surface of the right-angle gauge, the probe is always applied in the same direction with respect to the reference measurement surface, and the probe is placed at a plurality of locations along the mechanical axis of the three-dimensional measuring machine. Since the coordinate measurement is performed by moving it, each measured coordinate value may include an instruction error due to the direction in which the probe is applied.

Therefore, the present invention solves the problem of the accuracy verification gauge of the conventional three-dimensional measuring machine as described above, verifies the indication error and straightness of the three-dimensional measuring machine in each machine axis direction, and determines between the machine axes. It is an object of the present invention to provide a right-angle step gauge capable of performing a right angle verification of a high accuracy with a single gauge.

The right-angled step gauge of the present invention provided for the above-described purpose includes a substantially square bar-shaped first reference member holding portion and a second reference member holding portion, each of which is formed of a flat surface having parallel upper and lower surfaces. The side surfaces of the first reference member holding portion and the second reference member holding portion that are adjacent to each other at right angles are intersected at right angles at the central position in the direction within the same plane and joined in a substantially cross shape in plan view. A gauge body made of a material having a small coefficient of thermal expansion and excellent dimensional stability, which is connected by reinforcing ribs that are brazed between each other, and each of the first reference member holding part and the second reference member holding part of the gauge body A plurality of reference members having a reference measurement surface arranged along the longitudinal direction with which a probe tip of the three-dimensional measuring machine contacts, wherein the plurality of reference members include a first reference member holding portion and a second reference member. Each of the holding part Parallel to the plane and the lower surface with respect to the virtual neutral plane located somewhere in between, it is characterized in that it is arranged vertically symmetrically.

In the right-angled step gauge of the present invention, the reference members arranged in the first reference member holding part and the second reference member holding part are fitted and fixed in mounting holes penetrating the upper and lower surfaces of these reference member holding parts. A hollow cylindrical bush having an inner peripheral surface as a reference measurement surface is desirable.

Further, the reference members arranged in the first reference member holding portion and the second reference member holding portion are bonded and held in spherical concave portions formed on the upper and lower surfaces of these reference member holding portions, respectively, and the surface is measured as a reference. It is also desirable that the sphere be a surface.

Furthermore, in the right angle step gauge of the present invention, reference member holding pieces that protrude perpendicularly in both directions from the upper and lower surfaces are fixed to both ends of the first reference member holding portion and the second reference member holding portion. It is also preferable that a pair of reference members arranged symmetrically with respect to the virtual neutral plane is mounted on each of the reference member holding pieces.

In the right angle step gauge according to the present invention, the first reference member holding portion and the second reference member holding portion are formed with first screw holes opened on both upper and lower surfaces, and the screw A second screw hole and a third screw are respectively provided on the upper and lower surfaces of the pair of reinforcing ribs located on the left and right sides opposite to the crossing position of the first reference member holding portion and the second reference member holding portion with respect to the hole A hole is formed, and the first screw hole is disposed at a position corresponding to the vertex of an isosceles triangle with the center of the intersection position of the first reference member holding portion and the second reference member holding portion as the centroid. The second screw hole and the third screw hole are arranged at positions corresponding to both ends of the base of the isosceles triangle, and the first to third screw holes are respectively provided from the upper and lower sides of the gauge body. Support the gauge body on the measurement table of the CMM It is also desirable that the support leg is screwed.

According to the right angle step gauge according to the first aspect of the invention, verification of the perpendicularity between the two mechanical axes can be performed together with the verification of the positioning accuracy of the probe of the three-dimensional measuring machine and the straightness of each mechanical axis. Since the measurement can be performed with only one gauge and the reversal measurement method can be performed by reversing the upper and lower surfaces of the gauge, the accuracy of the three-dimensional measuring machine can be verified with high accuracy.

According to the right-angled step gauge according to the invention described in claim 2, in addition to the effect obtained from the invention of claim 1, the tolerance range of dimensional tolerance is strictly defined for quality control in many machine products. The accuracy of the three-dimensional measuring machine can be verified by the same probe movement as the measurement of the hole diameter, so the reliability of the hole diameter of the product measured by the three-dimensional measuring machine verified by the right-angle step gauge of the present invention Can be increased.

According to the right angle step gauge according to the third aspect of the present invention, in addition to the effects obtained from the first aspect of the invention, the reference measurement surface is a spherical surface, and therefore the probe of the three-dimensional measuring machine can be moved in various directions. The degree of freedom of the mounting posture of the right-angle step gauge with respect to the measurement table can be increased.

According to the right angle step gauge according to the invention described in claim 4, in addition to the effects obtained from the inventions of the respective claims, the first reference member holding portion and the second reference member holding portion are further provided at both ends. Since the reference member holding piece mounted with a pair of reference members arranged symmetrically with respect to the virtual neutral plane is fixed, the virtual step gauge setting position relative to the three-dimensional measuring machine can be changed without changing the setting posture. It is possible to easily check the accuracy of the machine axis in the direction orthogonal to the neutral plane.

According to the right-angled step gauge according to the invention described in claim 5, in addition to the effects obtained from the inventions of the respective claims, three support legs are screwed to the upper and lower surfaces of the gauge body. Therefore, the weight of the right-angle step gauge can be uniformly distributed and supported, and can be stably set on the measurement table of the three-dimensional measuring machine without rattling.

It is a perspective view which shows the state which set the right angle step gauge of this invention to the three-dimensional measuring machine. It is a perspective view which shows one Embodiment of the right angle step gauge of this invention. It is a top view showing one embodiment of a right angle step gauge of the present invention. It is a side view showing one embodiment of the right angle step gauge of the present invention. FIG. 4 is a sectional view taken along the line II in FIG. 3. FIG. 4 is a sectional view taken along the line II-II in FIG. 3. It is a fragmentary sectional view which shows the connection part of the support leg of a 1st reference member holding | maintenance part, and an attachment jig. It is a disassembled perspective view of the connection part of a 1st reference member holding part and an attachment jig. FIG. 5 is a cross-sectional view taken along the line III-III in FIG. FIG. 5 is a sectional view taken along line IV-IV in FIG. 4. It is a perspective view which shows another embodiment of the right angle step gauge of this invention. It is a fragmentary sectional view which shows the attachment structure to the gauge main body of a sphere.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
FIG. 1 is a perspective view showing a state in which a right-angle step gauge according to the present invention is set in a three-dimensional measuring machine. As shown in FIG. 1, three-dimensional measurement in which accuracy inspection is performed by the right-angle step gauge 1 according to the present invention. The machine 2 has a measurement table 3 on which an object to be measured is placed.

On both sides of the measurement table 3, a gate-shaped movable frame 4 is slidably supported along a horizontal machine axis in the X direction. The movable frame 4 supports a head unit 5 slidably along a horizontal Y-direction mechanical axis perpendicular to the X direction. Further, the head unit 5 includes a lifting cylinder 6. It is supported so as to be movable up and down along a vertical machine axis in the Z direction.

Further, the probe head 6A provided at the tip of the elevating cylinder 6 has a posture between the posture in which the probe 7 is directed vertically downward as shown in FIG. It is kept changeable.

When the accuracy inspection of the three-dimensional measuring machine 2 configured as described above is performed, a right-angle step gauge 1 is set on the measurement table 3 and arranged on the right-angle step gauge 1 as shown in FIG. The coordinate value of each measurement point is measured by bringing the tip of the probe 7 into contact with each reference measurement surface of the reference member, and these measurement values are precisely measured by a more advanced measuring machine. By comparing with the reference value of the right-angle step gauge 1, the positioning accuracy and straightness in each machine axis direction (X, Y, and Z directions) and the perpendicularity between each machine axis are verified.

In addition, when measuring the dimensions of the finished surface of a workpiece such as an engine block by the three-dimensional measuring machine 2, a workpiece (not shown) to be measured on the measurement table 3 is used instead of the right-angle step gauge 1. ) And moving the movable frame 4, the head unit 5, and the lifting cylinder 6 in the X, Y, and Z directions, respectively, and bringing the tip of the probe 7 into contact with the surface to be measured of the workpiece, Measure the coordinate value of the surface.

FIG. 2 is a perspective view showing an embodiment of a right-angle step gauge according to the present invention, FIG. 3 is a plan view, and FIG. 4 is a side view. The first reference member holding portion 8 and the second reference member holding portion 9 each having a substantially square bar shape, each of which is formed of parallel flat surfaces finished in the above-described manner.

In addition, since the right angle step gauge 1 may be used upside down or vertically, the term “upper surface” of the right angle step gauge 1 means the front side surface shown in FIG. , "Bottom surface" means the back surface of the figure.

These reference

member holding portions

8 and 9 intersect with each other at a central position in the longitudinal direction at right angles within the same plane and are integrally coupled in a substantially cross shape in plan view. In addition, the side surfaces of the first reference member holding portion 8 and the second reference member holding portion 9 that are adjacent to each other at right angles are coupled to each other by bracing reinforcing

ribs

10, 11, 12, and 13 in order to increase rigidity. ing.

Also, each of the reference

member holding portions

8 and 9 is formed with a plurality of lightening holes h and h ′ penetrating the upper and lower surfaces in order to reduce the weight. The first reference member holding portion 8 and the second reference member An integrated gauge main body 14 is configured by the member holding portion 9 and the reinforcing

ribs

10, 11, 12, and 13.

Further, in the right-angled step gauge 1 of the present embodiment, a rectangular parallelepiped reference projecting in both vertical directions from the upper and lower surfaces of each of the first reference member holding portion 8 and the second reference member holding portion 9 is provided. The member holding piece 15 is fixed.

In the present embodiment, the gauge body 14 and these reference member holding pieces 15 are manufactured by Super Invar. Note that these materials are not limited to Super Invar, and materials having a small coefficient of thermal expansion and excellent dimensional stability such as tool steel, glass, granite, and the like can be used.

In the first reference member holding part 8 and the second reference member holding part 9, five bushes 16 are arranged at equal intervals in the longitudinal direction, and these reference

member holding parts

8, 9 intersect. A bush 16 common to both the arrays is disposed at the central position. Two similar bushings 16 are also arranged vertically on each of the reference member holding pieces 15. The detailed structure of these reference member holding pieces 15 will be described later.

5 is a cross-sectional view taken along the line II of FIG. 3. As shown in FIG. 5, the bushing 16 is fitted in the mounting hole 17 that vertically penetrates the upper and lower surfaces of the second reference member holding portion 9. The cylindrical portion 16 </ b> A is formed, and the flange portion 16 </ b> B is in contact with the peripheral edge portion of the mounting hole 17 on the upper surface side of the second reference member holding portion 9.

The bush 16 is formed with a through hole concentric with the mounting hole 17 at the center, and the inner peripheral surface thereof is finished with high accuracy. The inner peripheral surface serves as a reference measurement surface S with which the tip of the probe 7 of the coordinate measuring machine 2 shown in FIG. 1 abuts, except for an inner portion of the flange portion 16B protruding from the upper surface of the second reference member holding portion 9. used.

The material of the bush 16 used here is stainless steel to avoid rusting of the reference measurement surface S, and is fixed to the mounting hole 17 by an adhesive used to prevent screws and nuts from loosening. ing. In addition, although illustration is abbreviate | omitted, the bush 16 provided in the other location of the right-angled step gauge 1 is also fixed similarly.

Further, in the present embodiment, in order to facilitate the assembly, the bush 16 is provided with the flange portion 16B that abuts on the peripheral edge portion of the mounting hole 17, but the flange portion 16B has the three-dimensional measuring machine 2 disposed therein. Therefore, the bush 16 may be a hollow cylindrical shape that is substantially vertically symmetrical with the inner peripheral surface of the through hole as the reference measurement surface S, and may be configured only by the cylindrical portion 16A. Good.

Also, the right-angle step gauge 1 is provided with support legs 18 for installation on a measurement table of a three-dimensional measuring machine. In the present embodiment, the support leg 18 includes a screw hole formed so as to vertically penetrate between the upper and lower surfaces of the first reference member holding portion 8, and the upper and lower portions of the two reinforcing

ribs

10 and 11, respectively. A total of six screw holes, one from each of the upper and lower sides of the gauge body 14, are attached to a total of three screw holes formed vertically penetrating between both surfaces.

The reason why three support legs 18 are attached to each of the upper and lower sides of the gauge body 14 is that the right-angle step gauge 1 is horizontally placed on the measurement table 3 with these support legs 18 to measure the accuracy of the three-dimensional measuring machine. When measuring, the coordinate value of the center of each bushing 16 is measured on the upper surface side of the right-angled step gauge 1, and the coordinate value of the through-hole center of these bushings 16 is measured again on the lower surface side by reversing the top and bottom. This is because an inversion measurement method for obtaining an average value of the respective coordinate values on both the upper and lower surfaces can be used. By using the inversion measurement method, the manufacturing error of the right-angle step gauge 1 itself is canceled out, so that the accuracy measurement of the three-dimensional measuring machine 1 can be performed more accurately.

A screw hole (first screw hole) formed in the first reference member holding portion 8 to which the support leg 18 is screwed is an intersection position of the first reference member holding portion 8 and the second reference member holding portion 9. Are formed at positions corresponding to the vertices of a virtual isosceles triangle with the center of the centroid as the centroid.

Further, a screw hole (second screw hole) formed in the reinforcing rib 10 for screwing the support leg 18 and a screw hole (third screw hole) formed in the reinforcing rib 11 for screwing the support leg 18. Are formed at positions corresponding to both ends of the base of the virtual isosceles triangle.

By arranging the positions of the three screw holes for attaching the support legs 18 in this way, each support leg 18 can receive the weight of the right-angle step gauge 1 evenly. Even so, it can be set on the measurement table 3 without rattling. In order to stably support the right-angle step gauge 1 on the measurement table 3, it is desirable that the isosceles triangle is an equilateral triangle.

FIG. 6 is a cross-sectional view taken along the line II-II in FIG. 3. As shown in FIG. 6, on the upper surface side of the reinforcing rib 11, the upper surfaces of the first reference member holding portion 8 and the second reference member 9 described above A support leg mounting surface 11A that protrudes from the other part of the reinforcing rib 11 is formed so as to be at the same level.

Further, the lower surface 11B of the reinforcing rib 11 is a flat surface at the same level as the lower surfaces of the first reference member holding portion 8 and the second reference member 9, and between the support leg mounting surface 11A and the lower surface 11B, A screw hole N1 is formed so as to pass through perpendicularly to the surface.

Supporting legs 18 are attached to both sides of the screw hole N1, respectively. These support legs 18 have a support leg main body 18A in which a large-diameter portion a is formed at the center in the longitudinal direction and screw portions b and c are formed at both ends.

Between the threaded portion b and the large-diameter portion a of the support leg main body 18A, a smooth portion d that is not threaded is formed. In addition, a flat washer 18B, a concave spherical washer 18C, and a convex spherical washer 18D are sequentially attached to both sides of the large-diameter portion a on the support leg main body 18A, and one screw portion b is attached to the support leg attachment. Screwed into the screw hole N1 of the reinforcing rib 11 from the respective sides of the surface 11A and the lower surface 11B up to the boundary position with the smooth portion d, and fixed by an adhesive used to prevent loosening such as bolts and nuts.

Further, a mounting nut 18F is screwed to the other threaded portion c of the support leg main body 18A on the flat back side of the convex spherical washer 18D via a plain washer 18E. When the right angle step gauge 1 is set on the measurement table 3 of the coordinate measuring machine 2 shown in FIG. 1 in the vertical orientation using the mounting jig, the mounting nut 18F is used as the mounting leg 18A. Used to fix. The fixing to the mounting jig will be described later.

As shown in FIG. 6, these support legs 18 include a virtual plane P <b> 1 in which the upper surfaces of the support leg mounting surface 11 </ b> A, the first reference member holding portion 8, and the second reference member 9 are included, and the reinforcing ribs 11. The lower surface 11B and the lower surfaces of the first reference member holding portion 8 and the second reference member 9 are parallel to a virtual plane P2 that is included in common, and symmetrically up and down with respect to a virtual neutral plane Pn that is located in the middle thereof. Has been placed. Note that the lower surfaces of the reinforcing

ribs

10, 12, and 13 are also at the same level as the virtual plane P2.

Further, as shown in FIGS. 2 and 3, the reinforcing rib 10 is also formed with a supporting leg mounting surface 10A similar to the supporting leg mounting surface 11A, on both sides of the supporting leg mounting surface 10A and its lower surface. Support legs 18 are attached in the same manner. Further, the support legs 18 attached to the upper and lower surfaces of the first reference member holding portion 8 are also arranged symmetrically with respect to the virtual neutral plane Pn.

When the right-angle step gauge 1 is set on the measurement table 3 of the coordinate measuring machine 2, the mounting nut 18F is removed from the screw portion c of the upward support leg 18, and an eye nut (not shown) is attached instead. By connecting a wire to the eye nut, the step gauge 1 can be suspended on the wire and moved onto the measurement table 3.

FIG. 7 is a partial cross-sectional view showing a connection portion when the support leg 18 attached to the lower surface side of the first reference member holding portion 8 is connected to the attachment jig 19, and FIG. 8 is an exploded view of the connection portion. In these drawings, only a part of the structure of the mounting jig 19 is shown, but the mounting jig 19 is placed on the measurement table 3 of the three-dimensional measuring machine 2 shown in FIG. It has a function as a support for holding the right-angle step gauge 1 in a vertical orientation.

A mounting hole 19A is formed in the mounting jig 19. The mounting hole 19A has an inner diameter and a depth that can accommodate the entire large-diameter portion a of the support leg main body 18A inside, and inserts the large-diameter portion of the support leg main body 18A as shown in FIG. By sandwiching the mounting jig 19 between the flat washer 18B loosely fitted in the smooth portion d and the flat washer 18B loosely fitted in the screw portion c, and tightening the mounting nut 18F, the support leg 18 is interposed. The first reference member holding portion 8 can be fixed to the mounting jig 19.

At this time, the flat washers 18B on both sides sandwiching the mounting jig 19 are arranged on the back or front of the mounting jig 19 by the concave spherical washer 18C and the convex spherical washer 18D. Since the inclination is automatically adjusted so that the support leg 18 and the mounting jig 19 are not perpendicular to each other, a bending load does not act on the support leg 18 and the first reference member holding portion 8 is securely fixed to the mounting jig 19 via the support legs 18.

In addition, in the thing of this embodiment, in order to make easy incorporation of the large diameter part a to the mounting hole 19A, the threaded part c side of the large diameter part a is a conical surface. Here, although the overall shape of the mounting jig 19 is not shown, the two support legs 18 (FIG. 2 or FIG. 2) attached to the lower surfaces of the two reinforcing

ribs

10 and 11 of the right-angle step gauge 1 respectively. 3) is similarly fixed to the mounting jig 19 respectively.

7 is attached to the support leg 18 on the lower surface side of the first reference member holding portion 8, but can also be attached to the support leg 18 on the upper surface side. In this case, the reinforcing

ribs

10 and 11 may be attached to the mounting jig 19 with the support legs 18 on the upper surface side.

9 is a cross-sectional view taken along the line III-III of FIG. 4, and FIG. 10 is a cross-sectional view taken along the line IV-IV. As shown in these figures, the reference member holding piece 15 has the connecting bolt 20 passed through the bolt hole 15A. The first reference member holding part 8 and the second reference member holding part 9 are screwed into screw holes N2 formed in the respective end faces and fixed to these end faces.

As shown in FIG. 10, a pair of knock pins 21 are incorporated on both sides of the connecting bolt 20 between the first reference member holding portion 8 and the reference member holding piece 15, and the first reference member is formed by these knock pins 21. The attachment position of the reference member holding piece 15 with respect to the holding portion 8 is positioned.

An adhesive holding groove 15B is formed on the surface of the reference member holding piece 15 facing the first reference member holding part 8, and the second reference member holding part is filled with an adhesive in the groove. 8 is more secure.

In addition, the said adhesive agent is using the same thing as the adhesive agent used when fixing the bush 16 to the attachment hole 17. FIG. Although not shown, the mounting structure between the second reference member holding portion 9 and the reference member holding piece 15 is the same as that of the first reference member holding portion 8.

As shown in FIGS. 2 and 3, two measurement points k are provided on the upper end surface of each reference member holding piece 15. Note that two measurement points are provided on the lower end surface that cannot be seen from these drawings, as in the upper end surface.

The measurement point k is a circular area finished with a high-precision plane, and after setting the right-angle step gauge 1 on the measurement table 3 of the three-dimensional measuring machine 2 as shown in FIG. The tip of the probe 7 is applied to these measurement points k and is used to determine the coordinate plane of the reference coordinate system.

Next, the procedure for verifying the squareness of the three-dimensional measuring machine 2 shown in FIG. 1 by the reversal measurement method using the right-angle step gauge 1 configured as described above will be described below. The procedure for verifying the positioning accuracy and straightness in the respective machine axis directions is the same as that of a conventionally known step gauge, and thus the description thereof is omitted here.

(Procedure 1)
First, the right-angle step gauge 1 is set on the measurement table 3 of the three-dimensional measuring machine 2 as shown in FIG. Here, the longitudinal direction of the first reference member holding portion 8 (see FIG. 2) of the right-angle step gauge 1 is set parallel to the Y-direction mechanical axis of the three-dimensional measuring machine 2.

(Procedure 2)
Next, two upper end surfaces of each of the four reference member holding pieces 15 shown in FIG. 2 or 3, the probe 7 is applied to a total of eight measurement points k, and a plane including these measurement points k is obtained. It is set as the reference coordinate plane (xy coordinate plane) of the reference coordinate system (x, y, z) associated with the right-angle step gauge 1.

(Procedure 3)
Next, on the reference measurement surfaces S of the five bushes 16 arranged in the longitudinal direction of the first reference member holding portion 8, eight locations in the circumferential direction at two different predetermined depths from the reference coordinate plane. The probe 7 is applied one by one to determine the center axis of these reference measurement surfaces S, and the reference axis of the y-axis of the reference coordinate system is determined based on the coordinate values of a predetermined depth from the reference coordinate surface of the five center axes. Ask for.

(Procedure 4)
Next, the center axis lines of the reference measurement surfaces S of the five bushes 16 arranged in the longitudinal direction of the second reference member holding part 9 are obtained in the same manner as in the procedure 3 described above, and predetermined values of these five center axis lines are determined. Based on each coordinate value of the depth, the x-axis reference axis line of the reference coordinate system is obtained.

(Procedure 5)
Next, the x-axis and y-axis reference axis lines obtained in

steps

3 and 4 are associated with the machine coordinate system (rectangular coordinate system) (X, Y, Z) of the three-dimensional measuring machine 2 by coordinate transformation. A reference coordinate system (x, y, z) is determined.

(Procedure 6)
Next, the perpendicularity α between the X axis and the Y axis is calculated based on the reference coordinate system (x, y, z) set on the table (upper surface) side of the right-angle step gauge 1. Here, the perpendicularity α is obtained by making the xy plane of the reference coordinate system (x, y, z) parallel to the XY plane of the machine coordinate system (X, Y, Z) and that the y axis and the Y axis are The angle error between the X-axis and the x-axis when rotated so as to coincide is shown.

(Procedure 7)
Next, after the right-angle step gauge 1 is turned upside down with the longitudinal direction of the first reference member holding portion 8 as an axis, the longitudinal direction of the first reference member holding portion 8 is three-dimensional in the same manner as in the procedure 1 described above. Setting is made on the measurement table 3 so as to be parallel to the machine axis of the measuring machine 2 in the Y direction.

(Procedure 8)
Next, in the same manner as in the procedure 2 described above, each of the upper end surfaces of the four reference member holding pieces 15 (note that the right-angle step gauge 1 is turned upside down, so the lower end surfaces in FIGS. 2 and 3). The probe 7 is applied to a total of eight measurement points k in two places, and a plane including these measurement points k is set as a reference coordinate plane (xy coordinate plane) of the reference coordinate system (x, y, z). To do.

(Procedure 9)
Next, in the same manner as in the above-described procedure 3, each of the reference measurement surfaces S of the five bushes 16 arranged in the longitudinal direction of the first reference member holding portion 8 has two different predetermined points from the reference coordinate surface. The central axes of these reference measurement surfaces S are obtained by applying the probes 7 at eight positions in the circumferential direction at the depth, and based on the respective coordinate values of a predetermined depth from the reference coordinate planes of the five central axes. The y-axis reference axis line of the reference coordinate system is obtained.

(Procedure 10)
Next, in the same manner as in the procedure 4 described above, the center axis lines of the respective reference measurement surfaces S of the five bushes 16 arranged in the longitudinal direction of the second reference member holding portion 9 are obtained, and the five center axis lines are obtained. Based on each coordinate value of a predetermined depth, the x-axis reference axis line of the reference coordinate system is obtained.

(Procedure 11)
Next, the x-axis and y-axis reference axis lines obtained in

steps

9 and 10 are associated with the machine coordinate system (rectangular coordinate system) (X, Y, Z) of the three-dimensional measuring machine 2 by coordinate transformation. A reference coordinate system (x, y, z) is determined.

(Procedure 12)
Next, in the same manner as in the procedure 6 described above, the perpendicularity between the X axis and the Y axis based on the reference coordinate system (x, y, z) set on the back (lower surface) side of the right-angle step gauge 1 β is calculated.

(Procedure 13)
Next, the true square angle γ between the XY axes of the three-dimensional measuring machine 2 is obtained as γ = (α + β) / 2 from the square angle α calculated in step 6 and the square angle β calculated in step 12. .

Here, α and β include an error of the right-angle step gauge 1 itself. By averaging these two values, the error of the right-angle step gauge 1 itself is removed, and the squareness of the three-dimensional measuring machine 2 is calculated. γ can be calculated with high accuracy.

That is, assuming that the error (perpendicularity) of the right-angle step gauge 1 itself is δ, γ = α + δ. On the other hand, if the right-angle step gauge 1 is inverted about the y axis, the sign of δ is inverted. β−δ.

Therefore, the average value of α and β is the true squareness γ. For example, if α = 0.02 and β = 0.03, the perpendicularity γ between the mechanical axes X and Y of the three-dimensional measuring machine 2 is γ = 0.025. At this time, the squareness δ of the right-angle step gauge 1 itself is δ = (β−α) /2=0.005.

Note that the right-angle step gauge 1 may be measured by setting the first reference member holding portion 8 in parallel with the X-direction mechanical axis of the three-dimensional measuring machine 2. Further, the second reference member holding portion 9 may be turned upside down with the longitudinal direction as an axis.

Further, the perpendicularity between the mechanical axes in the Y direction and the Z direction of the three-dimensional measuring machine 2 and between the mechanical axes in the Z direction and the X direction is verified by using the right-angle step gauge 1 in FIGS. 7 and 8 described above. By setting in a vertical orientation on the measurement table 3 using the mounting jig 19 shown, it can be performed in the same manner as the procedure for obtaining the perpendicularity between the mechanical axes in the X direction and the Y direction described above.

Further, in the right-angled step gauge 1 of the present embodiment, the reference member holding pieces 15 fixed at both ends of the first reference member holding portion 8 and the second reference member holding portion 9 are respectively mounted two vertically. The positioning accuracy in the Z-axis direction can be confirmed using the bushing 16 while the right-angle step gauge 1 is set horizontally on the measurement table 3.

Further, the right-angle step gauge 1 was set vertically on the measurement table 3 by using a mounting jig so that the upper surface or the lower surface was parallel to the YZ plane or the ZX plane of the three-dimensional measuring machine 2. The positioning accuracy in the X-axis direction or the Y-axis direction can be confirmed as it is.

In the embodiment described above, when determining the reference coordinate plane, the probe 7 is applied to the measurement point k provided on the upper and lower end faces of the reference member holding piece 15, but the position of the measurement point is the reference position. It is not limited to the member holding piece 15.

For example, on the upper surface (front) side of the right-angle step gauge 1, the measurement point is a point in the vicinity of the support leg 18 on the upper surface of the first reference member holding portion 8, a point on the support leg mounting surface 10A of the reinforcing rib 10, and A point on the support leg mounting surface 11A of the reinforcing rib 11 and on the lower surface (back) side, a point near the support leg 18 on the lower surface of the first reference member holding portion 8 and a point near the support leg 18 on the lower surface of the reinforcing rib 10 And it is good also as the point of the supporting leg 18 vicinity of the reinforcement rib 11 lower surface.

Also, a treatment for preventing rusting, such as applying a rust-preventing paint, may be applied to the measurement points where the probe 7 of the right-angle step gauge 1 is brought into contact and the portions other than the reference measurement surface S of the bush 16.

FIG. 11 is a perspective view showing another embodiment of the right-angle step gauge of the present invention. A right-angle step gauge 1 ′ shown in FIG. 11 is a zirconia sphere 16 having a surface as a reference measurement surface S ′ as a reference member. 'Is used.

Except for the mounting structure of the sphere 16 ', the right-angle step gauge 1' has the same structure and material as the gauge body 14 'and the reference member holding piece 15'. The same is true.

FIG. 12 is a longitudinal sectional view of the intersecting portion of the first reference member holding portion 8 ′ and the second reference member holding portion 9 ′ of the right-angle step gauge 1 ′. As shown in FIG. Each of the spherical concave portions 17 ′ fitted to the spheres 16 ′ formed on the upper and lower surfaces of the intersecting portion is fixed symmetrically with respect to the virtual neutral plane Pn using an adhesive.

Similarly, the spheres 16 ′ arranged at other locations are similarly fixed vertically symmetrically with respect to the virtual neutral plane Pn. Further, as shown in FIG. 11, the reference member holding piece 15 ′ attached to each end of the first reference member holding portion 8 ′ and the second reference member holding portion 9 ′ has a spherical body 16 ′ only on the outer surface. Are fixed two above and below.

In addition, although each of the right-angle step gauges 1 and 1 ′ in the embodiments described above includes the reference

member holding pieces

15 and 15 ′, these may be omitted. Further, the support leg 18 has a structure that also serves as a mounting member for the mounting jig 19, but the present invention is not limited to this, and the gauge body is directly connected to the mounting jig by means such as screwing. You may make it do.

The accuracy inspection of the three-dimensional measuring machine 2 shown in FIG. 1 using the right-angle step gauge 1 ′ shown in FIG. 11 is basically the same as the inspection procedure using the right-angle step gauge 1 described above. When the step gauge 1 ′ is used, the probe 7 is moved to a plurality of points on the reference measurement surface S ′ of the sphere 16 ′ (for example, four points separated from each other on the equator of the reference measurement surface S ′ (spherical surface), The coordinate value of the center of the sphere 16 'is obtained from these coordinate values.

Claims

The first reference member holding portion and the second reference member holding portion, each of which has a substantially rectangular bar shape and is formed of flat surfaces whose upper and lower surfaces are parallel to each other, intersect at right angles at the center position in the longitudinal direction within the same plane. The coefficient of thermal expansion is such that the side surfaces of the first reference member holding part and the second reference member holding part, which are adjacent to each other at right angles, are connected by bracing reinforcing ribs. A gauge body made of a small and excellent dimensional stability material,
A plurality of reference members having a reference measurement surface, which is arranged along the longitudinal direction of each of the first reference member holding part and the second reference member holding part of the gauge body and abuts on the probe tip of the three-dimensional measuring machine. Prepared,
The plurality of reference members are arranged vertically symmetrically with respect to a virtual neutral plane that is parallel to the upper surface and the lower surface of each of the first reference member holding portion and the second reference member holding portion and located in the middle thereof. Right angle step gauge characterized by.
The reference members arranged in the first reference member holding part and the second reference member holding part are fitted and fixed in mounting holes penetrating the upper and lower surfaces of these reference member holding parts. The right angle step gauge according to claim 1, wherein the bush is a hollow cylindrical bush.
The reference members arranged in the first reference member holding part and the second reference member holding part are bonded and held in spherical recesses formed on the upper and lower surfaces of these reference member holding parts, respectively, and the surface is defined as a reference measurement surface. The right angle step gauge according to claim 1, wherein the right angle step gauge is a sphere.
Reference member holding pieces that protrude perpendicularly in both directions from the upper and lower surfaces are fixed to both ends of the first reference member holding portion and the second reference member holding portion, respectively. The right angle step gauge according to any one of claims 1 to 3, wherein a pair of reference members arranged symmetrically with respect to a plane are mounted.
Either one of the first reference member holding portion and the second reference member holding portion is formed with a first screw hole that opens on both upper and lower surfaces thereof, and the first reference member holding portion is formed with respect to the screw hole. And a second screw hole and a third screw hole are respectively formed on the upper and lower surfaces of the pair of reinforcing ribs located on the left and right sides on the opposite side of the intersecting position of the second reference member holding portion,
The first screw hole is disposed at a position corresponding to the apex of an isosceles triangle with the center of the intersecting position of the first reference member holding portion and the second reference member holding portion as the centroid, and the second screw The hole and the third screw hole are arranged at positions corresponding to both ends of the base of the isosceles triangle,
2. A support leg for supporting the gauge body on a measurement table of a three-dimensional measuring machine is screwed into each of the first to third screw holes from above and below the gauge body. The right-angle step gauge in any one of thru | or 4.