Measuring jig

Abstract

To more simply measure a gear shape.SOLUTION: A measurement tool used when measuring a shape of an outer periphery of a gear includes: a mandrel that penetrates a center hole of the gear and is disposed concentrically with the gear; a disk member disposed concentrically with the gear in the mandrel; a pair of support portions for supporting the mandrel; and a rotation regulation mechanism for regulating rotation of the gear by resiliently engaging an engagement element to the outer periphery of the gear. The outer periphery of the disk member is a sliding surface on which the measurement element slides so as to specify the center of the gear, and the outer periphery of the disk member is positioned on a virtual circle surrounding the center axis at a predetermined interval when seen from a direction of the center axis of the mandrel.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a measuring jig. [Background technology]

[0002] Patent Document 1 discloses a gear runout measuring device. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 7-103855 Summary of the Invention

[0004] Typically, the shape of the outer periphery of a gear is measured using a three-dimensional shape measuring machine (CMM measuring machine) or a measuring machine dedicated to gears. [Problem to be solved by the invention]

[0005] However, CMM measuring machines are large and expensive, so there is a demand for a method that can measure gear shapes more easily. [Means for solving the problem]

[0006] One aspect of the present invention is A measuring jig used when measuring the outer periphery shape of a gear with a measuring element, a mandrel that passes through a center hole of the gear and is disposed concentrically with the gear; a disk member disposed concentrically with the gear on the mandrel; A pair of support portions that support the mandrel; a rotation restriction mechanism that restricts rotation of the gear by elastically engaging an engaging element with the outer periphery of the gear, The outer periphery of the disk member is a sliding surface along which the measuring probe slides to identify the center of the gear, and when viewed from the direction of the central axis of the mandrel, the outer periphery of the disk member is positioned on an imaginary circle that surrounds the central axis at a predetermined interval. [Effects of the Invention]

[0007] According to one aspect of the present invention, the shape of a gear can be measured more easily. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a schematic diagram of the measuring jig. [Figure 2] FIG. 2 is a schematic diagram showing a measurement device with a measurement jig placed on a surface plate, as viewed from the front. [Figure 3] FIG. 3 is a schematic cross-sectional view of the measuring jig taken along line AA in FIG. [Figure 4] FIG. 4 is a schematic cross-sectional view of the measuring jig taken along line BB in FIG. [Figure 5] FIG. 5 is a schematic cross-sectional view of the measuring jig taken along line AA in FIG. [Figure 6] FIG. 6 is a schematic cross-sectional view of the measuring jig taken along line BB in FIG. [Figure 7] FIG. 7 is a schematic cross-sectional view of the measuring jig taken along line AA in FIG. [Figure 8] FIG. 8 is a schematic cross-sectional view of the measuring jig taken along line CC in FIG. [Figure 9] FIG. 9 is a schematic cross-sectional view of the measuring jig taken along line DD in FIG. [Figure 10] FIG. 10 is a cross section of the measuring jig taken along line DD in FIG. 3, and is a diagram schematically illustrating the state when the disk member supported by the mandrel is positioned at the central measurement position. [Figure 11] FIG. 11 is a diagram showing a cross section of the gear supported by the mandrel when the gear is placed at the shape measurement position. [Figure 12] FIG. 12 is a diagram showing a gear placed at a shape measurement position as viewed from above. [Figure 13] FIG. 13 is a diagram showing a cross section of a gear when a disk member supported by a mandrel is placed at the center measurement position. [Figure 14] FIG. 14 is a diagram showing a disk member placed at the central measurement position as viewed from above. [Figure 15] FIG. 15 is a diagram illustrating the relationship between the gear center and the tooth groove center. [Figure 16] FIG. 16 is a diagram illustrating another embodiment of the mandrel. [Figure 17] FIG. 17 is a diagram illustrating the restriction mechanism. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, an embodiment of the present invention will be described. FIG. 1 is a schematic diagram of a measuring jig 1. As shown in FIG. FIG. 2 is a schematic diagram showing the measurement device 5 with the measuring jig 1 placed on the surface plate 55 as viewed from the front. FIG. 3 is a diagram schematically showing a cross section of the measuring jig 1 taken along the line AA in FIG. Fig. 4 is a diagram schematically showing a cross section of the measuring jig 1 taken along line BB in Fig. 2. Fig. 4 also shows a surface plate 55 on the side of the measuring device 5 on which the measuring jig 1 is placed.

[0010] As shown in Figures 1 and 2, measuring jig 1 is used when measuring the shape of the outer periphery of gear 2. The shape of the outer periphery of gear 2 is measured using a measuring element 54 of measuring device 5, which will be described later. When measuring the shape of the outer periphery of gear 2, measuring jig 1 is placed on a surface plate 55 of measuring device 5 (see Figure 2).

[0011] The measuring jig 1 has a base 10 that is rectangular in top view. A rotation restricting mechanism 3 is provided on one side of the base 10 in the longitudinal direction. A gear support mechanism 4 is provided on the other side.

[0012] The rotation restricting mechanism 3 has a support member 31 , a holder 32 supported by the support member 31 , and an engaging element 35 supported by the holder 32 . 3, when viewed from above, the holder 32 is disposed in a direction along the axis Y. Here, the axis Y is perpendicular to the axis X (central axis) described later. 2, the support member 31 has a plate-shaped mounting portion 310 and a plate-shaped holder support portion 312. The mounting portion 310 and the holder support portion 312 are an integral part that are provided orthogonal to each other. In a side view, the support member 31 has an L-shape (see FIG. 4).

[0013] The mounting portion 310 is attached to the base portion 11 . The attachment portion 310 extends linearly in a direction away from the holder support portion 312 . 3, the mounting portion 310 has elongated holes 310a, 310a. The elongated holes 310a, 310a penetrate the mounting portion 310 in the thickness direction. The elongated holes 310a, 310a are provided in a direction along the extension direction of the mounting portion 310 (the direction of the axis X described below). The mounting portion 310 is fixed to the upper surface of the base portion 11 by mounting screws N that penetrate the elongated holes 310a, 310a. The support member 31 is displaceable in the direction of the axis X (up and down in the drawing) by the length of the elongated holes 310a, 310a. The position of the support member 31 in the direction of the axis X is adjustable by the length of the elongated holes 310a, 310a.

[0014] The pedestal portion 11 is placed on a guide rail 12 provided on a base 10. As shown in FIG. 3, the guide rail 12 is provided in a direction along an axis Y1. The axis Y1 is a straight line parallel to the axis Y. As shown in FIG. 4, the lower side of the guide rail 12 is accommodated in a recessed groove 10b provided in the base 10. The pedestal portion 11 is supported by the guide rail 12 via a connecting portion 111. The pedestal portion 11 is movable in the direction of the axis Y1 along the longitudinal direction of the guide rail 12.

[0015] A guide 13 is provided on the base 10 at a position adjacent to the guide rail 12. The lower side of the guide 13 is housed in a recessed groove 10c (see FIG. 4) provided in the base 10. The guide 13 is a concave member with an opening facing upward, and is housed in the concave groove 10c with the groove 131 facing upward. The lower end 112 a of the positioning bolt 112 that passes through the base portion 11 is inserted into the groove 131 .

[0016] 3, the guide 13 is provided in a direction along the axis Y2, which is a straight line parallel to the axes Y and Y1. The base 11 is movable in the direction of the axis Y1 along the guide rail 12. Therefore, the position of the positioning bolt 112 is also movable in the direction of the axis Y2 in conjunction with the movement of the base 11. In this embodiment, after the base part 11 is moved in the direction of the axis Y1, the positioning bolt 112 is tightened to bring the lower end 112a of the positioning bolt 112 into pressure contact with the groove 131. In this way, the positioning bolt 112 functions as a stopper that restricts the movement of the base part 11 in the direction of the axis Y2.

[0017] As shown in FIG. 4, the holder support portion 312 is provided in a direction perpendicular to the upper surface 10a of the base 10. 3, holder support part 312 has a recess 313 on the surface opposite to mounting part 310. A movable plate 361 of screw feed mechanism 360 is positioned in recess 313. A guide member 33 that movably supports holder 32 is fixed to movable plate 361 with a bolt (not shown). 3, a feed screw 363 passes vertically through the center of the movable plate 361. Guide rails 362, 362 pass vertically on both sides of the feed screw 363. The movable plate 361 is supported by the guide rails 362, 362 installed in the recess 313 so as to be movable vertically.

[0018] 4, one end of the feed screw 363 passes upward through the upper wall portion 314 of the holder support portion 312. A handle portion 363a is provided at one end of the feed screw 363. The other end 363b of the feed screw 363 is screwed into the holder support portion 312. In the screw feed mechanism 360, when the handle portion 363a protruding from the upper part of the holder support portion 312 is rotated around the Z axis, the movable plate 361 and the guide member 33 fixed to this movable plate 361 are displaced in the vertical direction.

[0019] In a cross-sectional view, the guide member 33 has a substantially rectangular shape. An insertion hole 330 for the holder 32 is formed in the center of the guide member 33. 3, the holder 32 is an integrated part having a handle portion 321, a shaft portion 322, and a support portion 323. The holder 32 is made of a metal material. In the holder 32, a handle portion 321, a shaft portion 322, and a support portion 323 are arranged in this order in the direction of the axis Y. The handle portion 321, the shaft portion 322, and the support portion 323 are arranged concentrically.

[0020] Handle portion 321 is a cylindrical portion connected to the base end of shaft portion 322. Handle portion 321 is formed with a smaller outer diameter than shaft portion 322. The outer periphery of handle portion 321 is knurled to prevent slippage.

[0021] The shaft portion 322 is formed with an outer diameter that matches the inner diameter of the insertion hole 330 of the guide member 33. A locking groove 324 is provided on the outer periphery of the shaft portion 322. The locking groove 324 has a first groove portion 324a extending linearly along the axis Y direction and a second groove portion 324b extending in the circumferential direction around the axis Y. The tip Nx1 of the screw Nx that penetrates the guide member 33 is engaged with the locking groove 324 from the radial direction of the axis Y. When the shaft portion 322 is rotated around the axis Y, the engagement destination of the tip Nx1 of the screw Nx can be changed between the first groove portion 324a and the second groove portion 324b. When the tip Nx1 engages with the first groove portion 324a, movement of the holder 32 in the direction of the axis Y (left and right direction in the figure) is permitted within the range of the first groove portion 324a. When the tip Nx1 engages with the second groove portion 324b, movement of the holder 32 in the direction of the axis Y is restricted.

[0022] 3, support portion 323 is a cylindrical portion with a bottom that connects to the tip of shaft portion 322. The opening of support portion 323 faces away from shaft portion 322. Support portion 323 is formed with an outer diameter larger than that of shaft portion 322.

[0023] The engaging element 35 is inserted into the support portion 323 from the direction of the axis Y. The engaging element 35 is an integral part having an insertion portion 351, a flange portion 352, and an engaging portion 353, and is made of a metal material. In the engaging element 35, an insertion portion 351, a flange portion 352, and an engaging portion 353 are arranged in this order in the direction of the axis Y. The insertion portion 351, the flange portion 352, and the engaging portion 353 are arranged concentrically.

[0024] The insertion portion 351 is formed with an outer diameter that matches the opening 325 of the support portion 323. A groove 351a is provided in the middle of the insertion portion 351 in the direction of the axis Y. The groove 351a is provided over the entire circumference in the circumferential direction around the axis Y. The flange portion 352 is formed with an outer diameter larger than that of the opening 325 . The engaging portion 353 is formed in a tapered shape such that the outer diameter decreases with increasing distance from the flange portion 352. The engaging portion 353 has a spherical contact portion 353a at its tip.

[0025] The engaging element 35 is positioned by inserting the insertion portion 351 into the opening 325 until the flange portion 352 abuts against the open end of the support portion 323. In this state, the shank of the screw Ny that penetrates the support portion 323 is engaged with the groove 351a of the insertion portion 351. The screw Ny prevents the engaging element 35 from falling off the support portion 323.

[0026] After the spring Sp is fitted onto the shaft portion 322, the holder 32 is inserted into the insertion hole 330 of the guide member 33 from the handle portion 321 side. The shaft portion 322 is inserted into the insertion hole 330 to a position where the tip Nx1 of the screw Nx can be engaged with the locking groove 324 on the outer periphery of the shaft portion 322. In this state, the shaft portion 322 passes through the insertion hole 330 in the direction of the axis Y. The spring Sp fitted onto the shaft portion 322 is held in a compressed state between the support portion 323 and the guide member 33.

[0027] The holder 32 is biased by a spring Sp in a direction (to the right in the figure) that brings the engaging element 35 closer to the gear 2. When the tip Nx1 of the screw Nx is engaged with the first groove portion 324a, the holder 32 can be displaced in the axial Y direction by the length of the first groove portion 324a in the axial Y direction. When the tip Nx1 of the screw Nx is engaged with the second groove portion 324b, displacement of the holder 32 in the axial Y direction is restricted. The screw Nx restricts the holder 32 from falling off the guide member 33. 2, the engaging element 35 faces the outer periphery of the gear 2 supported by the gear support mechanism 4 from the direction of the axis Y. When measuring the shape of the gear 2, the engaging element 35 resiliently engages with the outer periphery of the gear 2 by the biasing force of the spring Sp, thereby restricting the rotation of the gear 2. 2, the axis Y corresponds to a horizontal line passing through the axis X. The engaging piece 35 engages with the outer periphery of the gear 2 at a position where the outer diameter of the gear 2 in the direction of the axis Y (horizontal line) is greatest.

[0028] 3, the gear support mechanism 4 has a pair of support parts 41 (41A, 41B) and a movable base 42. The support parts 41 (41A, 41B) are positioned on the upper surface of the movable base 42 by headed screws N4. The movable base 42 is a plate-like member provided in a direction along the axis X. A support part 41B is fixed to one end 42a of the movable base 42. A support part 41A is provided on the other end 42b side of the movable base 42. In the following description, the support portions 41A and 41B will be simply referred to as the support portion 41 unless they are to be particularly distinguished from each other.

[0029] FIG. 5 is a diagram schematically showing a cross section of the measuring jig 1 taken along the line AA in FIG. FIG. 6 is a diagram schematically showing a cross section of the measuring jig 1 taken along line BB in FIG. FIG. 7 is a diagram schematically showing a cross section of the measuring jig 1 taken along line AA in FIG. 5 to 7 also show the mandrel 7 placed on the support portion 41 (41A, 41B). Fig. 8 is a diagram schematically showing a cross section of the measuring jig 1 taken along line CC in Fig. 3. In Fig. 8, a cross section of the second positioning mechanism 46 is shown. Fig. 9 is a schematic cross-sectional view of the measuring jig 1, taken along line DD in Fig. 3, with the gear support mechanism 4 cut away. Fig. 9 shows a cross-section of the first positioning mechanism 45. Figure 10 is a cross-section of the measuring jig 1, taken along line DD in Figure 3, through the gear support mechanism 4, and is a schematic diagram showing the state when the disc member 74 of the mandrel 7 is positioned at the central measurement position. 5 to 10 also show a surface plate 55 on the side of the measuring device 5 on which the measuring jig 1 is placed.

[0030] As shown in FIGS. 5 and 7, the movable base 42 is placed on a guide rail 14 provided on the base 10. As shown in FIG. 3, the guide rail 14 is provided in a direction along the axis X. The axis X is a straight line perpendicular to the axis Y described above. As shown in FIGS. 5 and 7, the lower side of the guide rail 14 is accommodated in a recessed groove 10d provided in the base 10. The movable base 42 is supported on the guide rail 14 via a connecting portion 421. The movable base 42 is movable in the direction of the axis X, which is along the longitudinal direction of the guide rail 14. Specifically, when viewed from above, the movable base 42 is displaceable between a first position (shape measurement position: see Figure 12) in which the gear 2 described below is positioned on the axis Y, and a second position (center measurement position: see Figure 14) in which the disc member 74 of the mandrel 7 described below is positioned on the axis Y.

[0031] 3, the gear support mechanism 4 has positioning mechanisms (a first positioning mechanism 45 and a second positioning mechanism 46). The first positioning mechanism 45 is provided to position the movable base 42 at a first position (a shape measurement position). The second positioning mechanism 46 is provided to position the movable base 42 at a second position (a center measurement position).

[0032] The configuration of the positioning mechanisms (first positioning mechanism 45, second positioning mechanism 46) will be described below. 2, the first positioning mechanism 45 is located on the rotation restriction mechanism 3 side (left side in the figure) when viewed from the movable base 42. The second positioning mechanism 46 is located on the opposite side of the rotation restriction mechanism 3 when viewed from the movable base 42 (right side in the figure). The movable base is located between the first positioning mechanism 45 and the second positioning mechanism in the direction of the axis Y (the left-right direction in the drawing).

[0033] 3, the first positioning mechanism 45 is located on one end 42a of the movable base 42 in the direction of the axis X. The second positioning mechanism 46 is located on the other end 42b of the movable base 42 in the direction of the axis X. The first positioning mechanism 45 is located on one side of the axis Y (upper side in the figure). The second positioning mechanism 46 is located on the other side of the axis Y (lower side in the figure).

[0034] In a top view, the first positioning mechanism 45 is located to the side of the support portion 41B. The first positioning mechanism 45 has a connecting portion 451 , an extending portion 452 , and a supporting portion 453 . 9, the connecting portion 451 is a plate-like member having a length L451 in the direction of the axis X. The thickness W451 of the connecting portion 451 is smaller than the thickness W42 of the movable base 42. The connecting portion 451 is provided at a position near the lower side of the movable base 42.

[0035] The extending portion 452 extends from approximately the center of the connecting portion 451 in the length direction (left-right direction in the drawing) in a direction away from the connecting portion 451 (toward the front side of the paper). A thickness W452 of the extending portion 452 is thinner than a thickness W451 of the connecting portion 451, and an upper surface 452a of the extending portion 452 serves as a mounting surface for the support portion 453. The support portion 453 is fixed to the upper surface of the extending portion 452 with screws N6, N6.

[0036] The first positioning mechanism 45 has a through-hole 454 that penetrates the support portion 453 and the extension portion 452. The through-hole 454 is oriented along the vertical line VL (the up-down direction in the drawing). A cylindrical positioning pin 455 penetrates the through-hole 454 downward toward the base 10.

[0037] The connecting portion 451 of the first positioning mechanism 45 is fixed to the side surface of the movable base 42 with screws N5, N5. Therefore, the positioning pin 455 passing through the through hole 454 moves in the direction of the axis X in conjunction with the movement of the movable base 42 in the direction of the axis X.

[0038] A positioning hole 101 is formed in the upper surface of the base 10. The positioning hole 101 is a bottomed hole that opens to the upper surface 10a of the base 10. The positioning hole 101 is formed with an inner diameter that allows the positioning pin 455 to be inserted therein.

[0039] In this embodiment, the position of the positioning hole 101 is set so that the positioning pin 455 is inserted into the positioning hole 101 by its own weight when the movable base 42 reaches the first position (shape measurement position) described above. Therefore, by simply moving the movable base 42 toward the first position until the positioning pin 455 is inserted into the positioning hole 101 under its own weight, the movable base 42 can be easily moved to the first position and positioned at the first position.

[0040] As shown in Figure 8, the second positioning mechanism 46 has a guide portion 47 arranged on the side of the movable base 42, an operating portion 48, and a bolt 49 that passes through the operating portion 48 and the guide portion 47 in the direction of the axis Y3. 3, the guide portion 47 is a plate-like member provided in a direction along the axis X. As shown in FIG. 6, the guide portion 47 has an attachment portion 471 fixed to the base 10 and a protrusion 472 protruding upward from the attachment portion 471. The mounting portion 471 has a length L471 in the direction of the axis X. The lower side of the mounting portion 471 is housed in a recessed groove 10d provided in the base 10.

[0041] The attachment portion 471 has one end and the other end in the longitudinal direction fixed to the base 10 by screws N7, N7. The region between the screws N7, N7 in the guide portion 47 forms a protrusion 472. An upper end 472a of the protruding portion 472 is located slightly above the upper surface 42c of the movable base 42. The protruding portion 472 has an elongated hole 473 formed in a region facing the side surface of the movable base 42. The elongated hole 473 extends linearly in a direction along the axis X (left-right direction in the drawing).

[0042] 8, in this embodiment, the shaft 492 of the bolt 49 that penetrates the operating unit 48 penetrates the elongated hole 743 in the direction of the axis Y3. The axis Y3 is perpendicular to the axis X and is a straight line that is parallel to the upper surface 10a of the base 10. The tip of the shaft 492 is screwed into the side surface of the movable base 42. Therefore, the operating unit 48 and the bolt 49 move in the direction of the axis X in conjunction with the movement of the movable base 42 in the direction of the axis X. The elongated hole 473 is formed with a length L473 (see FIG. 6) in the direction of the axis X so as not to hinder the movement of the operating unit 48 and the bolt 49 in the direction of the axis X.

[0043] The operating portion 48 has a large diameter portion 481 , a small diameter portion 482 , and a lever portion 483 . The large diameter portion 481 and the small diameter portion 482 are arranged coaxially on the axis Y3. When viewed from the large diameter portion 481, the small diameter portion 482 is located on the guide portion 47 side (left side in the figure). The large diameter portion 481 has an opening 481a on the opposite side to the small diameter portion 482. The bolt 49 is inserted into the opening 481a from the direction of the axis Y3. The shaft portion 492 of the bolt 49 passes through the large diameter portion 481 and the small diameter portion 482 in the direction of the axis Y3. In this state, the head portion 491 of the bolt 49 is housed in the opening 481a.

[0044] The lever portion 483 extends from the outer periphery of the large diameter portion 481 in the radial direction of the axis Y3. The bolt 49 and the operating part 48 are connected so as not to rotate relative to each other, but are rotatable about the axis Y3. When the lever portion 483 is operated to rotate the operating portion 48 to one side about the axis Y3, the tip of the shaft portion 492 is screwed into the movable base 42, and the operating portion 48 is displaced in a direction approaching the movable base 42. Then, the small diameter portion 482 is pressed against the guide portion 47 (protruding portion 472), and the relative movement between the operating portion 48 and the guide portion 47 in the direction of the axis X is restricted. As a result, the movement of the movable base 42 into which the bolt 49 is screwed in is restricted in the direction of the axis X.

[0045] On the other hand, when the operating unit 48 is rotated in the other direction around the axis Y3, the tip of the shaft 492 is displaced in a direction away from the movable base 42, and the operating unit 48 is displaced in a direction away from the movable base 42. Then, the small diameter portion 482 moves away from the guide portion 47, and the pressure contact between the operating unit 48 and the guide portion 47 (protrusion 472) is released. As a result, relative movement between the operating unit 48 and the guide portion 47 in the direction of the axis X is permitted. This allows movement of the movable base 42 into which the bolt 49 is screwed in in the direction of the axis X.

[0046] In this embodiment, the movable base 42 is placed at the second position (central measurement position) and then the lever portion 483 is operated, thereby restricting the movement of the movable base 42 in the direction of the axis X. Therefore, the movable base 42 can be easily positioned at the second position.

[0047] The configuration of the support parts 41A and 41B installed on the movable base 42 will be described below. Supporting portions 41A and 41B have the same shape. As shown in Fig. 5, supporting portion 41 has a plate-shaped mounting portion 411 and a plate-shaped supporting plate portion 412. Mounting portion 411 and supporting plate portion 412 are integral parts that are provided orthogonal to each other. In a cross-sectional view along the axis X, the support plate portion 412 is provided at a midpoint in the longitudinal direction (left-right direction in FIG. 5) of the support portion 41. The support plate portion 412 extends linearly in a direction away from the attachment portion 411. In a cross-sectional view, the support portion 41 has a substantially T-shape. The support plate portion 412 is perpendicular to the upper surface 10 a of the base 10 .

[0048] The support part 41 has an insertion hole 411a formed in the mounting part 411. The support part 41 is fixed to the upper surface of the movable base 42 by threading a headed screw N4 that passes through the insertion hole 411a into a mounting hole 420 on the movable base 42 side.

[0049] 7, the support plate portion 412 has a width W412 in the direction of the axis Y. This width W412 is larger than an outer diameter D72 of a supported portion 72 of the mandrel 7 (described later) (W412>D72). The height h41 from the upper surface 10a of the base 10 to the upper end 412a of the support plate portion 412 is the same for both the support portion 41A and the support portion 41B. A recess 43 is provided in the center in the width direction of the upper end 412a of the support plate 412. The recess 43 has a shape that is symmetrical with respect to a vertical line VL that passes through the center of the support plate 412 in the width direction. The recess 43 has, on one side as viewed from the vertical line VL, an inclined surface 431 inclined at a predetermined angle (crossing angle θ) with respect to the vertical line VL, a side surface 432 parallel to the vertical line VL, and a bottom surface 433 perpendicular to the vertical line VL. The other side also has an inclined surface 431, a side surface 432, and a bottom surface 433.

[0050] In this embodiment, the supported portion 72 of the mandrel 7 is placed on the inclined surfaces 431, 431. In this state, the supported portion 72 is supported by one inclined surface 431 and the other inclined surface 431 in a state of line contact. The intersection angle θ of the inclined surface 431 with the vertical line VL is set to an angle that positions the center (axis X) of the mandrel 7 (supported portion 72) at the intersection point of the vertical line VL and the axis Y when the supported portion 72 is supported by the recess 43. This intersection angle θ is determined taking into consideration the outer diameter D72 of the supported portion 72.

[0051] 3, mandrel 7 is a support tool for supporting gear 2 to be measured. Gears 2 to be measured in measuring jig 1 are a plurality of types of gears having different outer diameters. For this reason, multiple mandrels 7 are prepared according to the type of gear 2 to be measured. When measuring the gear 2, one mandrel 7 determined according to the gear 2 to be measured is selected and used. Each mandrel 7 has the same basic shape, although the thickness and outer diameter of the disk member 74 (described below) differ depending on the gear 2 to be measured. Each mandrel 7 shares supported portions 72, 72 with the same outer diameter D72 (diameter).

[0052] 11 is a schematic diagram showing a cross section of the gear support mechanism 4 when the gear 2 supported by the mandrel 7 is placed at the shape measurement position (first position). This Fig. 11 corresponds to the cross section BB in Fig. 5. FIG. 12 is a diagram showing a state in which the gear 2 placed at the shape measurement position is viewed from above. FIG. 13 is a diagram schematically illustrating a cross section of the gear support mechanism 4 when the disk member 74 of the mandrel 7 is placed at the central measurement position (second position). FIG. 14 is a diagram showing a state in which the gear 2 placed at the central measurement position is viewed from above.

[0053] The basic structure of the mandrel 7 will be described below. 3, the mandrel 7 has a cylindrical shaft portion 71. The base end 71b side of the shaft portion 71 forms a grip portion 710. The outer periphery of the grip portion 710 is knurled to prevent slippage.

[0054] The shaft portion 71 is provided with a pair of supported portions 72, 72 spaced apart in the direction of the axis X. One supported portion 72 is provided at one end 71a of the shaft portion 71. The other supported portion 72 is provided at a position offset from the one end 71a toward the base end 71b. The supported portions 72, 72 are cylindrical portions having the same outer diameter D72. The outer diameter D72 is set to an outer diameter that allows the supported portions 72 to pass through the center hole 20 of the gear 2 supported by the mandrel 7.

[0055] Between the supported portions 72, 72, a collet 73, a disk member 74, and a stopper portion 75 are provided. The collet 73 has an operating part 731 that can rotate around the axis X, a movable part 732 that displaces in the direction of the axis X in conjunction with the rotation of the operating part 731, and an engaging part 733 whose outer diameter expands and contracts in conjunction with the displacement of the movable part 732 in the direction of the axis X. In collet 73, when operating portion 731 is rotated in one direction about axis X, movable portion 732 is inserted into engaging portion 733, and the outer diameter of engaging portion 733 increases. When operating portion 731 is rotated in the other direction about axis X, movable portion 732 is displaced in a direction away from engaging portion 733, and the outer diameter of engaging portion 733 decreases.

[0056] The mandrel 7 is positioned so that the shaft portion 71 is inserted into the center hole 20 of the gear 2 and the disk member 74 abuts against the gear 2. In this state, by rotating the operating portion 731 of the collet 73, the engagement portion 733 fits into the center hole 20 of the gear 2. As a result, the gear 2 to be measured is positioned adjacent to the disk member 74 on the mandrel 7. In this state, the gear 2 is arranged concentrically with the disk member 74 on the central axis (axis line X) of the mandrel 7 (shaft portion 71).

[0057] The disk member 74 is used to position the gear 2 fitted onto the shaft portion 71 of the mandrel 7 and to detect the center (rotation axis) of the gear 2. 13, the disk member 74 has a circular shape when viewed in the direction of the axis X. The disk member 74 is formed with an outer diameter D74 that is smaller than an imaginary circle Im2 that passes through the tooth groove portion 23 (tooth bottom portion 210) of the gear 2. Specifically, the outer diameter D74 of the disk member 74 is set so that the difference between the outer diameter D74 of the disk member 74 and the outer diameter of the gear 2 that is extrapolated onto the shaft portion 71 is within a predetermined range. In this embodiment, the outer periphery 74a of the disk member 74 is located radially inward of an imaginary circle Im1 that passes through the outer periphery of the gear 2 and an imaginary circle Im2 that passes through the tooth groove portion 23 of the gear 2. The imaginary circle Im74 that passes through the outer periphery of the disk member 74 and the imaginary circles Im1 and Im2 are concentric circles with their centers on the axis X.

[0058] As shown in FIG. 6, the stopper portion 75 is formed with an outer diameter slightly larger than that of the supported portion 72 . In this embodiment, when the supported portions 72, 72 of the mandrel 7 are placed on the supporting portions 41A, 41B, the following conditions are met. (a) The stopper portion 75 abuts against the side surface 410 of the support portion 41B from the direction of the axis X. (b) The disk member 74 abuts against the side surface 400 of the support portion 41A from the direction of the axis X. This restricts the relative movement between the mandrel 7 and the support portions 41A and 41B in the direction of the axis X. The side surface 410 is the side surface of the support portion 41B on the support portion 41A side (left side in the drawing), and the side surface 400 is the side surface of the support portion 41A on the support portion 41B side (right side in the drawing).

[0059] In this embodiment, the thickness W74 of the disk member 74 is changed according to the thickness W2 of the gear 2 supported by the mandrel 7, so that the center of the gear 2 supported by the mandrel 7 in the direction of the axis X (left and right direction in the drawing) is positioned on a vertical line VL perpendicular to the axis Y. For this reason, a mandrel 7 is prepared for each type of gear 2.

[0060] As shown in Figure 11, the gear 2 has teeth 22 on the outer periphery of a base 21 that surrounds a central hole 20. The teeth 22 are provided on the outer periphery of the base 21 over the entire circumferential direction around the rotation axis (axis X). The teeth 22 are provided at set intervals in the circumferential direction around the axis X. Between adjacent teeth 22, 22 in the circumferential direction, there is a tooth space 23 with which teeth of a mating gear can engage.

[0061] When viewed from the direction of the axis X, each of the tooth portions 22 protrudes radially outward from the outer periphery of the base portion 21. Each of the tooth portions 22 has a cross-sectional shape in which the circumferential width W narrows toward the radially outward side. A first side surface 221 on one side of the tooth portion 22 (tooth tip portion 220) in the circumferential direction around the axis X and a second side surface 222 on the other side have curved surfaces. The first side surface 221 has a first tooth surface 221a in an area adjacent to the tooth tip 220, and a first tooth base 221b in an area adjacent to the first tooth surface 221a.

[0062] The first tooth surface 221a has a curved cross-sectional shape. In cross-sectional view, the first tooth surface 221a is formed in a curved shape that bulges toward the adjacent tooth portion 22 with the tooth groove portion 23 therebetween. The first tooth base 221b also has a curved cross-sectional shape. In cross-sectional view, the first tooth base 221b is formed in a curved shape that is recessed in a direction away from the adjacent tooth portion 22. The first tooth flank 221a and the first tooth base 221b are continuously connected. The inner diameter side of the first tooth base 221b is continuously connected to the tooth bottom portion 210.

[0063] The tooth bottom portion 210 has an arc-shaped cross section. In cross section, the tooth bottom portion 210 is formed in a curved shape that bulges outward toward the outer diameter side of the gear 2. The tooth bottom portion 210 forms an arc shape along an imaginary circle Im2 whose center is the axis X. The second side surface 222 has a second tooth flank 222a adjacent to the tooth tip 220, and a second tooth base 222b adjacent to the second tooth flank 222a. The inner diameter side of the second tooth base 222b is continuously connected to the tooth bottom 210.

[0064] The second tooth flank 222a has a curved cross-sectional shape. In cross-sectional view, the second tooth flank 222a is formed in a curved shape that bulges toward the adjacent tooth portion 22 with the tooth groove portion 23 therebetween. The second tooth base 222b also has a curved cross-sectional shape. In cross-sectional view, the second tooth base 222b is formed in a curved shape that is recessed in a direction away from the adjacent tooth portion 22. The second tooth flank 222a and the second tooth base 222b are continuously connected.

[0065] The first tooth flank 221a and the second tooth flank 222a are formed in curved shapes that are symmetrical with respect to a diameter line Lc that passes through the center of the tooth groove portion 23. The first tooth base 221b and the second tooth base 222b are formed in curved shapes that are asymmetrical with respect to the diameter line Lc. In the gear 2, the first tooth flank 221a and the second tooth flank 222a have the same shape (curved shape), but the first tooth base 221b and the second tooth base 222b have different shapes (curved shapes).

[0066] 3 and 5, in the measuring jig 1, the gear 2 to be measured is placed at a predetermined position on the base 10 by placing the supported portions 72, 72 of the mandrel 7 in the recesses 43, 43 of the supporting portions 41A, 41B. In this state, the central axis (axis X) of the mandrel 7 is positioned horizontally with respect to the upper surface 10a of the base 10 and perpendicular to the axis Y and the vertical line VL. Note that since the measuring jig 1 is placed on the surface plate 55 of the measuring device 5, the central axis (axis X) of the mandrel 7 is horizontally with respect to the upper surface 55a of the surface plate 55 (see FIG. 5).

[0067] The gear shape measuring device 5 generates surface shape data of the outer periphery of the gear 2 by moving the measuring probe 54 along the outer periphery of the gear 2 positioned on the base 10 and continuously acquiring the coordinates of the tip of the measuring probe 54 (see Figures 11 and 12). Here, the tooth portions 22 and tooth space portions 23 are alternately arranged in succession in the circumferential direction around the axis X, so the surface shape data of the outer periphery of the gear 2 can also be said to be surface shape data of the tooth portions 22 and tooth space portions 23.

[0068] 2, the measuring device 5 has a support beam 53 that supports a measuring element 54, and a main body 52 that is provided on a guide column 51 so as to be able to move up and down. A drive mechanism (not shown) for the support beam 53 and a lifting mechanism (not shown) for the main body 52 are provided inside the main body 52. The main body 52 is connected to a calculation device (processing device: not shown) included in the measurement device 5. In the measurement device 5, based on instructions from the calculation device, an elevation mechanism (not shown) raises and lowers the main body 52, and a drive mechanism performs scanning with the measuring element 54, thereby obtaining surface shape data of the outer periphery of the gear 2 and identifying the center of the gear 2 (disk member 74).

[0069] The base end of the support beam 53 in the longitudinal direction is cantilevered by the main body 52. ​​The tip side of the support beam 53, on which the measuring element 54 is provided, is movable in the vertical direction. In this embodiment, in order to generate surface shape data of the outer periphery of gear 2 and to detect the position of the center of gear 2, the measuring probe 54 is able to displace at least within a range R2 from virtual circle Im1 to virtual circle Im74 (see Figure 13). The imaginary circle Im1 is an imaginary circle that passes through the outer periphery of the tooth portion 22 (tooth tip portion 220) when viewed from the axis X direction, and the imaginary circle Im74 is an imaginary circle that passes through the outer periphery 74a of the disk member 74 when viewed from the axis X direction. In addition, in the measurement device 5, when the measuring element 54 is displaced within this range R2, the surface shape data can be generated and the position of the center of the gear 2 can be determined without changing the position of the main body 52 (see Figure 2).

[0070] When acquiring surface shape data of the outer periphery of the gear 2, the support beam 53 is displaced in the circumferential direction of the gear 2 while biasing the measuring element 54 toward the outer periphery of the gear 2 (see FIG. 11). 11, the measuring element 54 slides on the outer periphery of the gear 2 along the trajectory indicated by the arrow. Raw data indicating the transition of the coordinates of the tip of the measuring element 54 during this process is output to a calculation device (processing device: not shown). The calculation device processes the input raw data to generate surface shape data of the outer periphery of the gear 2.

[0071] In this embodiment, the position of the center of the gear 2 is detected prior to generating surface shape data of the outer periphery of the gear 2. When detecting the position of the center of the gear 2, the support beam 53 biases the measuring element 54 toward the outer periphery 74a of the disk member 74 while displacing it in the circumferential direction of the disk member 74 (see FIG. 13). 13, the measuring element 54 slides on the outer periphery 74a of the disk member 74. From the transition of the coordinates of the tip of the measuring element 54 at this time, the center coordinates that define the center position of the disk member 74 are acquired. In the mandrel 7, the disk member 74 and the gear 2 are arranged concentrically with the central axis (axis line X) of the mandrel 7. Therefore, the acquired center coordinates of the disk member 74 become the center coordinates of the gear 2 as they are.

[0072] The process of measuring the shape of the outer periphery of the gear 2 will be described below. The shape of the outer periphery of the gear 2 is measured in the following procedure. (A) The gear 2 to be measured is attached to the mandrel 7. Specifically, the gear 2 to be measured is fitted onto the shaft portion 71 of the mandrel 7 and brought into contact with the disk member 74 (see FIG. 3). By operating the operating portion 731 of the collet 73, the gear 2 to be measured is positioned adjacent to the disk member 74 on the mandrel 7.

[0073] (B) The mandrel 7 with the gear 2 attached thereto is placed at a predetermined position on the base 10. Specifically, the supported portions 72, 72 of the mandrel 7 are placed on the recesses 43, 43 of the support portions 41A, 41B, and the stopper portion 75 and the disc member 74 of the mandrel 7 are abutted against the side surface 410 of the support portion 41B and the side surface 400 of the support portion 41A, respectively (see Figure 6). As a result, the mandrel 7 is placed at a predetermined position on the base 10 .

[0074] (C) The disk member 74 of the mandrel 7 is placed at the center measurement position (see FIGS. 10 and 14), and the center position of the gear 2 is identified from the center position of the disk member 74. Specifically, the movable base 42 is moved in the direction of the axis X, and the disk member 74 is placed at a position directly below the measuring element 54 (center measurement position: see FIGS. 10 and 14). In this state, the lever portion 483 of the second positioning mechanism 46 is operated in the counterclockwise direction CCW in FIG. 10 to restrict movement of the movable base 42 in the direction of the axis X. Next, the measuring element 54 is moved along the outer periphery 74a of the disk member 74 (see FIGS. 13 and 14). The center coordinate (axis X) of the disk member 74 is acquired from the transition of the coordinate of the tip of the measuring element 54 at this time. In the mandrel 7, the disk member 74 and the gear 2 are arranged concentrically with the central axis (axis X) of the mandrel 7. Therefore, the acquired center coordinate of the disk member 74 becomes the center coordinate of the gear 2 as it is.

[0075] (D) The gear 2 mounted on the mandrel 7 is placed at the shape measurement position (see Figures 3 and 9), and the outer shape of the gear 2 is measured. Specifically, the lever portion 483 of the second positioning mechanism 46 is operated in the clockwise direction CW in FIG. 10 to allow the movable base 42 to move in the direction of the axis X. In this state, the movable base 42 is moved in the direction of the axis X, and the gear 2 is placed at a position directly below the measuring element 54 (shape measurement position: see FIGS. 9 and 12). Immediately after the restriction on movement of the movable base 42 by the second positioning mechanism 46 is released, the movable base 42 is positioned at the central measurement position (second position) shown in Fig. 10. In this state, the positioning pin 455 is positioned away from the positioning hole 101 of the base 10, and the disk member 74 is positioned at a position intersecting with the vertical line VL passing through the axis Y.

[0076] When the movable base 42 is moved from the central measurement position (second position) shown in Fig. 10 toward the shape measurement position (first position) shown in Fig. 9, the positioning pin 455 is inserted into the positioning hole 101 by its own weight when the movable base 42 reaches the first position (shape measurement position). As a result, the positioning pin 455 inserted into the positioning hole 101 restricts the movement of the movable base 42 in the direction of the axis X, and the movable base 42 is positioned at the shape measurement position (first position). In this state, the gear 2 is positioned at a position where it intersects with a vertical line VL passing through the axis Y.

[0077] Next, the base 11 of the rotation restriction mechanism 3 is moved along the guide rail 12 in a direction approaching the gear 2 (to the right in FIG. 3 ) so that the engaging element 35 supported by the holder 32 engages with the outer periphery of the gear 2. In this state, the base 11 is positioned by the positioning bolt 112. Furthermore, the holder 32 is rotated around the axis Y to engage the tip Nx1 of the screw Nx with the second groove portion 324b. This restricts movement of the holder 32 in the direction of the axis Y, and the engaging element 35 is held in a position where it engages with the outer periphery of the gear 2. Therefore, the rotation of the gear 2 is restricted by the engaging element 35. In this state, the tooth groove portion 23 of the gear 2, where the shape measurement is to be performed, is positioned on the vertical line VL passing through the axis X (see FIG. 11). Furthermore, the engaging element 35 of the rotation restricting mechanism 3 engages with the outer periphery of the gear 2 from the direction of the axis Y, which is perpendicular to the vertical line VL (see FIG. 11).

[0078] (E) With the rotation of the gear 2 restricted, the measuring probe 54 is moved along the outer periphery of the gear 2 (see FIG. 11). From the transition of the coordinates of the tip of the measuring probe 54 at this time, shape data (hereinafter also referred to as shape data of the tooth gap) from the first side surface 221 of one tooth portion 22 of adjacent teeth 22, through the tooth bottom portion 210, to the second side surface 222 and tooth tip portion 220 of the other tooth portion 22 is acquired.

[0079] Figure 15 is a schematic diagram illustrating the relationship between the gear center and the tooth groove position. This figure explains the shape data of the gear outer periphery obtained in one measurement and the subsequent processing of the obtained shape data. In Figure 15, the range obtained in one measurement is shown by a thick line. Here, in processing the acquired shape data, in the program processing, a virtual circle ImC is placed at a position where it contacts the first tooth surface 221a of the first side surface 221 and the second tooth surface 222a of the second side surface 222, and the center of the virtual circle ImC at this time is set to the center of the tooth groove portion 23. As described above, the first tooth surface 221a and the second tooth surface 222a have shapes that are symmetrical with respect to the diameter line Lc that passes through the center of the tooth space portion 23. Therefore, the coordinates of the center of the imaginary circle ImC that contacts the first tooth surface 221a and the second tooth surface 222a correspond to the position of the center of the tooth groove portion 23 in the circumferential direction around the axis X.

[0080] Using the coordinates of the center of the tooth groove portion 23 (tooth groove center) as a reference, shape data is obtained from one first side surface 221 of the tooth portion 22, through the tooth bottom portion 210, to the other second side surface 222 and tooth tip portion 220 of another adjacent tooth portion 22. The acquired shape data is acquired in association with the above-mentioned center coordinates.

[0081] (F) The acquired shape data of the tooth gap portion 23 is compared with the shape data of the tooth gap portion 23 defined by the CAD data to check whether there is any defect in the shape of the tooth gap portion 23. Specifically, the acquired shape data of the tooth gap portion 23 and the shape data of the tooth gap portion 23 defined by the CAD data can be compared using the central coordinates as a reference. Therefore, the acquired shape data of the tooth gap portion 23 and the shape data of the tooth gap portion 23 defined by the CAD data are compared using the central coordinates as a reference. Then, as an example, the presence or absence of a shape defect is determined by comparing the difference between the acquired shape data of the tooth gap portion 23 and the shape data of the tooth gap portion 23 defined by the CAD data with a judgment threshold value.

[0082] Here, in the shape data (raw data) of the tooth gap portion 23 simply acquired, the position of the center C of the tooth gap portion can be identified by the imaginary circle ImC, but the diameter line Lc connecting the center C and the center of the gear 2 often has an inclination with respect to the vertical line VL passing through the center of the gear 2. Therefore, in this embodiment, the acquired shape data of the tooth gap portion 23 is rotated before being compared with the CAD data.

[0083] In the case of Figure 15, the diameter line Lc is located counterclockwise (left side in the figure) with respect to the vertical line VL. Therefore, the acquired shape data is rotated clockwise (right side in the figure) so that the diameter line Lc is positioned to follow the vertical line VL (see the bottom of Figure 15). This allows the acquired shape data to be compared with the data in CAD with the phase around the center of gear 2 aligned. (G) The shape of another tooth gap 23 adjacent to the tooth gap 23 whose shape has been measured is measured. Specifically, after the rotation restriction of the gear 2 by the engaging element 35 is released, the gear 2 is rotated around the axis X, and the tooth groove portion 23 adjacent to the tooth groove portion 23 whose shape has been measured is positioned directly below the measuring element 54. After restricting the rotation of the gear 2 with the engaging element 35, in this state, the measuring element 54 is moved along the outer periphery of the gear 2 (see FIG. 11). From the transition of the coordinates of the tip of the measuring element 54 at this time, shape data of other adjacent tooth groove portions 23 is acquired. The acquired shape data is acquired in association with the above-mentioned center coordinates. (H) The shape data of the adjacent tooth gap portions 23 is compared with the shape data of the tooth gap portion 23 defined by the CAD data to check for defects in the shape of the tooth gap portion 23.

[0084] (I) The shape of a predetermined number of adjacent tooth groove portions 23 (for example, four tooth groove portions 23) in the circumferential direction around the axis X is measured, and the presence or absence of defects in the shape of each tooth groove portion 23 is confirmed by comparing it with CAD data. (J) The shape of a predetermined number of tooth groove portions 23 at positions shifted by 180° in phase around the axis X of the gear 2 is measured, and the presence or absence of defects in the shape of each tooth groove portion 23 is confirmed by comparing it with the CAD data.

[0085] In this way, in this embodiment, the gear profile is measured tooth by tooth. Then, the raw data obtained by the measurement (transition data of the coordinates of the tip of the measuring element 54) is subjected to a rotation process, and shape data of the outer periphery of the gear is generated. Here, the coordinates of the tip of the measuring element 54 when measuring the shape of the outer periphery of the gear are plotted in a two-dimensional space (Y-VL space in FIG. 15) in the order in which they are acquired. Then, in the two-dimensional space, a range in which the coordinates of the tip of the measuring element 54 are plotted is specified, and the coordinates of the tip of the measuring element 54 are acquired and shape data is generated by connecting the acquired coordinates.

[0086] If rotation processing is not performed, it is necessary to specify the range used to generate shape data in two-dimensional space each time a gear shape is measured. On the other hand, by rotating the raw data, the positional relationship of the raw data obtained for each tooth space 23 is aligned. Therefore, it is not necessary to specify the range used to generate shape data each time. This makes it possible to perform quantitative analysis for each tooth space.

[0087] Furthermore, since the disk member 74 and the gear 2 are arranged concentrically in the mandrel 7, the initially measured central coordinates of the disk member 74 can be used as they are as the central coordinates of the gear 2 that serve as the reference when performing the rotation process. This eliminates the need to perform scanning to identify the central coordinates of the disk member 74 every time the shape of the tooth groove portion 23 is measured.

[0088] (K) Based on the results of checking whether there are any defects in the shape of each tooth groove portion 23, the presence or absence of defects in the shape of the outer periphery of the gear 2 is checked. The acquired shape data of the tooth groove portion 23 is associated with the center coordinates of the disk member 74. In the mandrel 7, the gear 2 and the disk member 74 are arranged concentrically with the central axis (axis line X) of the mandrel 7 (shaft portion 71). Therefore, the center coordinates of the disk member 74 correspond to the center coordinates of the gear 2. Therefore, the shape data of each tooth space can be compared with the shape data of the tooth space 23 defined by the CAD data, using the center coordinates of the disk member 74 as a reference. This makes it possible to check for defects in the gear shape.

[0089] FIG. 16 is a cross-sectional view illustrating a mandrel 7A used for another gear 2A. A mandrel 7 is prepared for each type of gear 2 to be measured. Each mandrel 7 is provided with a pair of common supported portions 72, 72. Each of the plurality of mandrels 7 has common supported portions 72, 72 with the same outer diameter.

[0090] The disk members 74 are different for each gear supported by the mandrel 7. Specifically, each mandrel 7 is provided with disk members 74 of different thicknesses depending on the gear 2 it supports.

[0091] In the case of the gear 2A shown in FIG. 16, the outer diameter D2A of the gear 2A is smaller than the outer diameter D2 (see FIG. 5) of the gear 2 (D2>D2A). Furthermore, the thickness W2A of the gear 2A is thicker than the thickness W2 of the gear 2 (W2 <W2A)。 Therefore, the disk member 74A of the mandrel 7A has a thickness W74' that is thinner than the disk member 74 by the amount of the increased thickness. This is to position the gear 2A supported by the mandrel 7A on the vertical line VL when the supported portions 72, 72 of the mandrel 7A are supported by the pair of supporting portions 41 (41A, 41B). In this embodiment, by changing the thickness of the disk member 74A, the center of the outer periphery of the gear 2A in the direction of the axis X is positioned so as to substantially overlap the vertical line VL.

[0092] Furthermore, the disk member 74A has an outer diameter D74' that is smaller than the outer diameter D74 of the disk member 74 described above, due to the reduction in the outer diameter of the gear 2. As described above, the measuring element 54 of the measuring device 5 is displaceable in the radial direction, and the measuring element 54 is displaceable beyond the predetermined range R2 (see FIG. 13) described above. Therefore, the disk member 74A is formed with an outer diameter smaller than the outer diameter of the gear supported by the mandrel 7A, within the range in which the measuring element 54 can be displaced. Therefore, by setting the outer diameter D74 of the disk member 74 so that the gear 2A is positioned on the vertical line VL, there is no need to move the main body 52 on the measuring device 5 side that supports the measuring element 54 during the period from when the center coordinates are obtained to when the outer shapes of the gears 2 and 2A are obtained.

[0093] If the main body 52 is moved between the acquisition of the center coordinates and the acquisition of the outer peripheral shapes of the gears 2 and 2A, the center coordinates of the disk member 74 cannot be set as the center coordinates of the gears. In such a case, the shape measurement of the outer periphery 74a of the disk member 74 by the measuring element 54, that is, the shape measurement for acquiring the center coordinates, will affect the shape measurement of the outer periphery of the gear 2 by the measuring element 54. As described above, there is no need to move the main body 52 on the measuring device 5 side that supports the measuring element 54 between the acquisition of the center coordinates and the acquisition of the outer shape of the gears 2 and 2A, so it is possible to preferably prevent the shape measurement for acquiring the center coordinates from affecting the shape measurement of the outer shape of the gear 2 by the measuring element 54.

[0094] In this embodiment, each mandrel 7 provided for each gear has common supported portions 72, 72 with the same outer diameter. Therefore, when the supported portions 72, 72 are supported by a pair of supports 41 (41A, 41B), the centers (axis X) of the gears 2 supported by the mandrels 7 are always positioned at the same height above the base 10. This eliminates the need to adjust the height position of the rotation restricting mechanism 3 to match the outer diameter of the gear 2 each time the type of gear 2 is changed. This makes it possible to effectively prevent a decrease in efficiency in the work of measuring the shape of the outer periphery of the gear 2. This is expected to reduce the work cost of measuring the shape of the outer periphery of the gear 2.

[0095] The position of the measuring element 54 of the measuring device 5 must be adjusted in the vertical direction according to the outer diameter of the gear. In this case, the main body 52 supporting the support beam 53 is displaced in the vertical direction along the guide columns 51. After adjusting the position of the measuring element 54, the mandrel 7 is moved in the direction of the axis X so that the gear or disc member to be measured is positioned directly below the measuring element 54. Therefore, when the gear to be measured is changed, the position of the measuring element 54 only needs to be adjusted once, reducing the burden of the measurement work.

[0096] In the above-described embodiment, an example was given of the case where the disk member 74 is extrapolated onto the shaft portion 71 of the mandrel 7 and arranged concentrically with the gear 2, i.e., the case where the disk member 74 is provided separately from the shaft portion 71. Here, the disk member 74 may be configured to be integral with the shaft portion 71. In such a case, by making the center of the disk member 74 concentric with the central axis (axis X) of the shaft portion 71, the same actions and effects as those of the above-described embodiment can be achieved.

[0097] In the embodiment described above, the rotation restricting mechanism 3 is positioned by pressing the positioning bolt 112 into the groove 131 of the guide 13 (see FIG. 4). Here, a bottomed hole into which the positioning bolt 112 can be inserted may be provided in the groove 131, and instead of positioning by pressing the positioning bolt 112, the rotation restriction mechanism 3 may be positioned in the axis Y direction by inserting the positioning bolt into the bottomed hole. In this case, a plurality of blind holes are arranged at intervals in the longitudinal direction of the guide 13.

[0098] In the above-described embodiment, the positioning pin 455 of the first positioning mechanism 45 is supported by a support portion 453 connected to the movable base 42 so as to be movable in the direction of the vertical line VL (see Figures 9 and 10).

[0099] The first positioning mechanism 45 may be provided with a restricting mechanism 60 for restricting the movement of the positioning pin 455 (see FIG. 17). The restriction mechanism 60 has a locking groove 61 provided on the outer periphery of the positioning pin 455 and a screw Nz that can be engaged with and disengaged from the locking groove 61. The locking groove 61 is composed of a first groove portion 61a that is aligned with the longitudinal direction of the positioning pin 455, and a second groove portion 61b that extends in the circumferential direction from the end of the first groove portion 61a on the base 10 side. The positioning pin 455 is movably supported by a cylindrical support tube 455 a provided on the support portion 453 . The locking groove 61 is engaged with the tip Nz1 of the screw Nz that passes through the support cylinder 455a. The screw Nz is engaged with the locking groove 61 from a direction perpendicular to the moving direction of the positioning pin 455. When the positioning pin 455 is rotated to engage the tip Nz1 of the screw Nz with the second groove portion 61b, the positioning pin 455 is held at a position spaced apart from the upper surface 10a of the base 10. When the tip Nz1 of the screw Nz is engaged with the first groove portion 61a, the positioning pin 455 becomes movable within the range of the first groove portion 61a.

[0100] By providing the restricting mechanism 60 having such a configuration, the movable base 42 can be moved in the axial direction without causing the positioning pin 455 to slide on the upper surface 10 a of the base 10 .

[0101] As described above, the measuring jig 1 according to this embodiment has the following configuration. (1) The measuring jig 1 is used when measuring the shape of the outer periphery (tooth portion 22, tooth space portion 23) of the gear 2 with a measuring element 54. The measuring jig 1 is a mandrel 7 that passes through a center hole 20 of the gear 2 and is arranged concentrically with the gear 2; a disk member 74 disposed concentrically with the gear 2 in the mandrel 7; A pair of support parts 41 (41A, 41B) that rotatably support the mandrel 7; a rotation restriction mechanism 3 that restricts rotation of the gear 2 by resiliently engaging an engaging element 35 with a tooth groove portion 23 on the outer periphery of the gear 2; and a measuring device 5 having a measuring element 54 for measuring the shape of the outer periphery of the gear 2.

[0102] When position information of the outer periphery 74a is acquired while the measuring element 54 is moved along the outer periphery 74a of the disk member 74, the central coordinates (position of the axis X) of the disk member 74 can be identified from the acquired position information. Since the disk member 74 and the gear 2 are arranged concentrically on the mandrel 7, the identified center coordinates of the disk member 74 become the center coordinates of the gear 2. Thereafter, position information is acquired while moving the measuring element 54 along the outer periphery of the gear 2, and shape data of the outer periphery (tooth portions 22, tooth groove portions 23) of the gear 2 is generated from the acquired position information. Here, the shape data of the outer periphery of the gear 2 is generated by measuring each tooth. By acquiring the center coordinates of the gear 2 in advance, the shape data generated for each tooth can be compared with the shape data of the gear 2 defined in the CAD data, using the center coordinates of the gear as the reference. This makes it possible to determine the suitability of the shape of each tooth on the outer periphery of the gear from the shape data generated for each tooth.

[0103] In this way, the measuring jig 1 can identify the center coordinates of the gear 2 and obtain shape data of the tooth groove portion 23 of the gear 2 based on the identified center coordinates, simply by displacing the mandrel 7 in the direction of the axis X, without changing the vertical position of the main body 52 that supports the measuring element 54. Furthermore, the shape data (coordinate data) defining the shape of each tooth space 23 can be compared with the shape data of each tooth space defined by the CAD data, based on the central coordinates of the gear 2. This allows the suitability of the shape of each tooth on the outer periphery of the gear to be properly determined, so the gear shape can be measured using the measuring jig 1 with a simple configuration, without the need for a high-performance dedicated device such as a CMM measuring device.

[0104] (2) The pair of support portions 41 (41A, 41B) support the mandrel 7 in a direction along a horizontal line parallel to the upper surface 10a of the base 10. The pair of support parts 41 (41A, 41B) are installed on a movable base 42 that is movable in the direction of the axis X.

[0105] In the mandrel 7, the disk member 74 and the gear 2 are arranged with their positions shifted in the direction of the axis X. By making the movable base 42 on which the support part 41 is placed movable in the direction of the axis X, the mandrel 7 can be displaced in the direction of the axis X while maintaining its posture. This allows the disk member 74 and the gear 2 to be disposed directly below the measuring element 54 without changing the position of the measuring element 54 in the direction of the axis X. The support beam 53 supporting the measuring element 54 allows the measuring element 54 to move in the direction of the vertical line VL for measuring the surface shape, while the position of the base end supported by the main body 52 in the direction of the axis X is fixed. Therefore, the acquired center position of the disk member 74 can be used as information indicating the center position of the gear 2. This makes it possible to acquire shape data of the outer periphery of the gear 2 based on the center position. Therefore, the acquired shape data can be compared with shape data specified in the CAD data, making it possible to appropriately measure the shapes of the teeth and tooth spaces of the gear.

[0106] (3) Mandrel 7 A shaft portion 71; The shaft portion 71 has a pair of supported portions 72, 72 arranged at an interval in the central axis direction (axis X direction). The pair of supported portions 72, 72 are formed to have the same outer diameter D72.

[0107] With this configuration, when the mandrel 7 is supported by the pair of supporting portions 41 (41A, 41B), the supported portions 72, 72 having the same outer diameter D72 are supported by the supporting portions 41 (41A, 41B). This allows the mandrel 7 to be stably held in an orientation along the axis Y and axis X parallel to the upper surface 10a of the base 10.

[0108] (4) In the shaft portion 71, Between the pair of supported portions 72, 72, a disk member 74 and a collet 73 (fitting mechanism) that fits into the center hole 20 are provided.

[0109] With this configuration, the gear 2 to be measured and the disk member 74 used to identify the center coordinates of the gear 2 are arranged concentrically with respect to the central axis (axis line X) between the two support points (supported portions 72, 72). Between the two support points, the gear 2 and the disk member 74 supported by the mandrel 7 are stably supported in an orientation along the horizontal line HL. This is expected to improve the accuracy in measuring the shape of the outer periphery of the gear 2 and in detecting the center of the disk member 74 (the center of the gear 2).

[0110] (5) A mandrel 7 is prepared for each type of gear 2 to be measured. Each mandrel 7 is provided with a pair of commonly-held portions 72, 72.

[0111] Each of the multiple mandrels 7 has a common supported portion 72, 72 with the same outer diameter. Therefore, when the supported portions 72, 72 are supported by a pair of supporting portions 41 (41A, 41B), the centers (axis X) of the gears 2 supported by the mandrels 7 are always positioned at the same height above the base 10. This eliminates the need to adjust the height position of the rotation restricting mechanism 3 to match the outer diameter of the gear 2 each time the type of gear 2 is changed. This makes it possible to effectively prevent a decrease in efficiency in the work of measuring the shape of the outer periphery of the gear 2. This is expected to reduce the work cost of measuring the shape of the outer periphery of the gear 2.

[0112] (6) The measuring jig 1 has a base 10 on which the rotation restricting mechanism 3 and the gear support mechanism 4 are installed. The base 10 is placed on a surface plate 55 of the measuring device 5 .

[0113] Since the base 10 of the measuring jig 1 is placed on the surface plate 55 of the measuring device 5, the positional relationship between the rotation restriction mechanism 3 and gear support mechanism 4 on the base 10 and the measuring element 54 on the measuring device 5 side is reliably fixed from the time the center coordinates are obtained until the outer shapes of the gears 2 and 2A are obtained. As a result, when the supported portions 72, 72 of the mandrel 7 are supported by the support portions 41 (41A, 41B) of the gear support mechanism 4, the positional relationship between the gear 2 and the measuring element 54 is also fixed. Therefore, the shape data obtained by measuring the shape of the outer periphery (tooth portion 22, tooth space portion 23) of the gear 2 in order with the measuring element 54 can be acquired in association with the common center coordinates. This allows each acquired shape data to be compared with the shape data defined in the CAD data, based on the center coordinates, so that the suitability of the shape of each tooth on the outer periphery of the gear can be more appropriately determined from the shape data generated for each tooth.

[0114] (7) The rotation restriction mechanism 3 is An engaging element 35, a holder 32 that holds the engaging element 35 so that the engaging element 35 can move in a direction perpendicular to the central axis (axis Y direction); a spring Sp that applies a biasing force to the holder 32 in a direction that causes the engaging piece 35 to engage with the outer periphery of the gear 2; a support member 31 that supports a holder 32; and a screw feed mechanism 360 (adjustment mechanism) that adjusts the vertical position of the holder 32 supported by the support member 31.

[0115] The arrangement of the tooth space portions 23 differs depending on whether the total number of teeth 22 on the outer periphery of the gear 2 is an even number or an odd number. Therefore, even if the engaging element 35 is arranged on the horizontal line HL passing through the axis X, the engaging element 35 and the tooth space portions 23 may not be arranged opposite each other. In this case, by making the position of the holder 32 adjustable in the vertical direction, the position of the engaging element 35 can be adjusted to a position facing the tooth groove portion 23. This makes it possible to suitably prevent the gear from being misaligned when measuring the shape of the outer periphery of the gear 2.

[0116] (8) The rotation restricting mechanism 3 is provided so as to be displaceable in the direction of the axis Y perpendicular to the axis X.

[0117] The measuring jig 1 is used to measure multiple types of gears 2. The outer diameters of the gears 2 vary depending on the type of gear. By providing the rotation restriction mechanism 3 so that it can be displaced in the direction of the axis Y, the engaging element 35 can be positioned at an appropriate position determined depending on the gear to be measured, and can be resiliently engaged with the outer periphery of the gear 2. This allows the rotation of the gear around the axis X to be restricted even for gears with different outer diameters, allowing the shape of the outer periphery of the gear 2 to be measured appropriately.

[0118] (I) The rotation restriction mechanism 3 is A support member 31; a holder 32 supported by a support member 31; an engaging element 35 supported by a holder 32; and a spring Sp that applies a biasing force to the holder 32 in a direction that biases the engaging piece 35 toward the gear 2. The holder 32 is disposed in a direction along the axis Y, and the engaging element 35 is engaged with the outer periphery of the gear 2. The support member 31 is supported by a base portion 11 that is movable along a guide rail 12 . The guide rail 12 is movable in the direction of an axis Y1 parallel to the axis Y.

[0119] With this configuration, when the gear 2 to be measured is changed and the outer diameter of the gear 2A to be measured after the change becomes smaller, the base portion 11 can be displaced along the guide rail 12 in a direction approaching the gear 2. In the mandrel 7 supported by the pair of support portions 41 (41A, 41B), the center of the gear 2 is always positioned at the same height, regardless of the outer diameter of the gear 2. Therefore, when the base portion 11 is displaced in a direction that brings it closer to the gear 2, the holder 32 attached to the base portion 11 can also be moved closer to the gear 2. When viewed from the direction of the axis X, the engaging element 35 supported by the holder 32 is located on the axis Y that is along the horizontal line HL that intersects with the axis X. Therefore, the engaging element 35 can be elastically engaged with the outer periphery of the gear 2 from the direction of the horizontal line HL without significantly changing the positional relationship of the engaging element 35 in the up-down direction.

[0120] (II) The disk member 74 of the mandrel 7 is formed to have an outer diameter D74 that is smaller than the imaginary circle Im2 that passes through the tooth groove portion 23 of the gear 2. The measuring element 54 on the measuring device 5 side can be displaced at least within a range R2 from the imaginary circle Im1 to the imaginary circle Im74.

[0121] With this configuration, there is no need to move the main body 52 on the side of the measuring device 5 that supports the measuring element 54 during the period from when the center coordinates are acquired until when the shape of the outer periphery of the gear 2 is acquired. Therefore, it is possible to suitably prevent the shape measurement of the outer periphery 74a of the disk member 74 by the measuring element 54, that is, the shape measurement for acquiring the center coordinates, from affecting the shape measurement of the outer periphery of the gear 2 by the measuring element 54.

[0122] (III) The pair of support portions 41 (41A, 41B) have recesses 43 on which the supported portions 72 are placed. When viewed from the direction of the axis X, the recess 43 has inclined surfaces 431, 431 that are inclined in a direction such that the distance between them increases as they go upward in the direction of the vertical line VL that passes through the center of the recess 43. The inclined surfaces 431, 431 are provided in a symmetrical positional relationship with respect to the vertical line VL. The intersection angle θ of the inclined surfaces 431, 431 with respect to the vertical line VL is set so that the engaging element 35 is positioned on a horizontal line HL passing through the center (axis X) of the supported portion 72 placed on the inclined surfaces 431, 431.

[0123] With this configuration, the rotation of the gear 2 supported by the pair of support parts 41 (41A, 41B) can be restricted by the engagement element 35 while reducing the frequency of adjusting the height of the engagement element 35 in the direction of the vertical line VL. This makes it possible to preferably prevent a decrease in efficiency in the work of measuring the shape of the outer periphery of the gear 2.

[0124] (IV) The gear support mechanism 4 has a first positioning mechanism 45 that positions the movable base 42 at a first position (shape measurement position) and a second positioning mechanism 46 that positions the movable base 42 at a second position (center measurement position).

[0125] This makes it possible to effectively prevent the mandrel 7 (gear 2, disk member 74) from moving in the direction of the axis X when the measuring element 54 is displaced along the outer periphery 74a of the disk member 74 and when the measuring element 54 is displaced along the outer periphery (tooth portion 22, tooth groove portion 23) of the gear 2. This allows the center coordinates and the shape of the outer periphery of the gear 2 to be acquired stably.

[0126] (V) The first positioning mechanism 45 has a support part 453 connected to the movable base 42, a positioning pin 455 that penetrates a through hole 454 provided in the support part 453 downward toward the base 10, and a positioning hole 101 that opens into the upper surface of the base 10. The base 10 is provided with a positioning hole 101 at a position where the positioning pin 455 is inserted into the positioning hole 101 by its own weight when the movable base 42 reaches the first position (shape measurement position).

[0127] With this configuration, after the acquisition of the center coordinates at the second position (center measurement position) is completed, the movable base 42 can be easily moved to the first position (shape measurement position) and positioned at the first position (shape measurement position) simply by moving the movable base 42 toward the first position (shape measurement position) until the positioning pin 455 is inserted into the positioning hole 101 under its own weight.

[0128] Although the embodiments of the present invention have been described above, the present invention is not limited to the aspects shown in these embodiments. The present invention can be modified as appropriate within the scope of the technical concept of the invention. [Explanation of symbols]

[0129] 1. Measuring equipment 2. 2A gear 20 center hole 3 Rotation restriction mechanism 31 Support member 32 Holder 35 Engagement element 360 Screw feed mechanism (adjustment mechanism) 4 Gear support mechanism 41 (41A, 41B) Support portion (pair of support portions) 42 Movable base 5. Measuring equipment 54 Measuring probe 7, 7A Mandrel 71 Shaft 72 supported part (pair of supported parts) 73 Collet (fitting mechanism) 74, 74A Disc member 74a outer circumference Im74 Virtual Circle Sp Spring X axis (center axis) Y axis (orthogonal to the central axis)

Claims

1. A measuring jig used when measuring the outer periphery shape of a gear with a measuring element, a mandrel that passes through a center hole of the gear and is disposed concentrically with the gear; a disk member disposed concentrically with the gear on the mandrel; A pair of support portions that support the mandrel; a rotation restriction mechanism that restricts rotation of the gear by elastically engaging an engaging element with the outer periphery of the gear, a measuring jig in which the outer periphery of the disk member is a sliding surface along which the measuring probe slides to identify the center of the gear, and when viewed from the direction of the central axis of the mandrel, the outer periphery of the disk member is located on an imaginary circle that surrounds the central axis at a predetermined interval.

2. In claim 1, the pair of support portions support the mandrel with the central axis of the mandrel aligned along a horizontal line, The pair of support parts are installed on a movable base that is movable in the direction of the central axis.

3. In claim 2, The mandrel A shaft portion; a pair of supported portions disposed at an interval in the central axis direction on the shaft portion, The pair of supported portions are formed with the same outer diameter.

4. In claim 3, In the shaft portion, The measuring jig has a fitting mechanism that fits into the disk member and the central hole, and is provided between the pair of supported portions.

5. In claim 3, The mandrel is prepared for each type of gear to be inspected, In the measuring jig, the pair of supported portions are commonly provided on each of the mandrels.

6. In claim 5, a base on which the movable base and the rotation restricting mechanism are installed, The base is a measuring jig that is placed on the surface plate of a measuring device.

7. In any one of claims 1 to 6, The rotation restriction mechanism includes: The engaging element; a holder that holds the engaging element so that the engaging element can move in a direction perpendicular to the central axis; a spring that applies a biasing force to the holder in a direction that causes the engaging element to engage with the outer periphery of the gear; a support member that supports the holder; and an adjustment mechanism for adjusting the vertical position of the holder.

8. In claim 7, The support member is provided so as to be positionable in a direction perpendicular to the central axis.

Images