JP2018036183A - System for automatically measuring screw shape - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a system for automatically measuring a screw shape, which is capable of automatically and accurately measuring an angle of a seating surface of a screw being a measurement object workpiece.SOLUTION: A system 10 for automatically measuring a screw shape includes: a grip rotating unit 60 which takes a screw 8 as a measurement object workpiece and rotationally drives a grip 62 holding the workpiece, at 360 degrees around an axial direction; a displacement meter 50 which includes an irradiation unit for emitting a laser beam to an outer peripheral surface of a screw shaft of the workpiece and a seating surface of a head of the workpiece and a photodetector for receiving reflected light of the laser beam, in a part in a circumferential direction of the workpiece and measures a displacement of a generatrix of the outer peripheral surface of the screw shaft and a generatrix of the seating surface; and an arithmetic and control unit 100 which calculates a first seating surface angle being an angle of the seating surface to a normal seating surface line orthogonal to a virtual axial line corresponding to an axial direction of the screw shaft, from data which indicates a two-dimensional shape based on displacement measured by the displacement meter in at least a first position among a plurality of peripheral positions around the axial direction of the workpiece, and a reference line indicating an axial direction of irradiation of the displacement meter.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a screw shape automatic measurement system, and in particular, a screw shape automatic measurement that calculates and outputs the angle of a seating surface with respect to a normal bearing surface line orthogonal to a virtual axis direction line of the workpiece, using a screw as a measurement target workpiece. About the system.

  A screw manufacturer measures various dimensions of a screw in order to ship the manufactured screw as a product that satisfies a predetermined standard. There are standards for various screw dimensions, and in order to measure to these standards, various types of measuring instruments such as micrometers, vernier calipers, screw gauges, etc. are used properly. Inspection is performed. The inspection result is recorded on the inspection table by the handwriting of the worker.

  Such a screw dimension measurement requires a lot of labor and time. Several automatic measurement methods have been proposed. For example, in Patent Document 1, as a screw inspection device, a screw head is fixed with a chuck unit, a parallel light beam is irradiated from a light emitter to a portion including the screw portion, and the screw portion is opposite to the light emitter. It is disclosed that a light-and-dark image of a screw portion is acquired by a provided light receiver, and that measurement information such as a screw length, a diameter width, and a screw thread is displayed by calculating with a computer the acquired image of the screw portion. Yes. It is stated that the light emitter and the light receiver can move along the axial direction of the screw portion, and the outer periphery of the screw can be inspected over 360 degrees by rotating the screw head and changing the direction of the screw portion.

  In Patent Document 2, as a screw shape measuring device, a light source that irradiates light parallel to a screw helix and a telecentric lens that has the same light receiving optical axis as that of the light source and forms an image of only a component parallel to the optical axis are used. An apparatus having an imaging device having a line sensor that acquires a one-dimensional image in a direction orthogonal to the axis of the screw is disclosed.

JP 2012-112929 A JP 2010-210292 A

  In the prior art, automatic measurement of the dimensional relationship of the screw portion has been proposed, but there is room for improvement in terms of measuring the bearing surface angle of the screw head. For example, the angle between the seat surface of the screw and the axial direction (seat surface angle) is designed to be 90 degrees, but the angle may deviate from 90 degrees due to manufacturing errors or the like. At this time, particularly when this angle is smaller than 90 degrees, the outer peripheral portion of the head covers the central portion, so that the connecting portion with the screw shaft of the seating surface of the head cannot be seen from the outside. Thus, as in the configurations described in Patent Documents 1 and 2, even when a parallel light beam is irradiated from the light emitter toward the screw and a light / dark image of the screw portion is acquired by the light receiver, the seating surface angle is obtained from the image. Is difficult to measure.

  An object of the present invention is to provide a screw shape automatic measurement system that can automatically and accurately measure the angle of the seating surface of a screw that is a workpiece to be measured.

  The screw shape automatic measurement system according to the present invention uses a screw as a measurement target workpiece, a gripping portion that grips one end of the workpiece on the screw side in the axial direction, and gripping that rotates the gripping portion 360 degrees around the axial direction. Laser light is applied to the outer peripheral surface of the screw shaft of the workpiece and the seating surface of the head of the workpiece in a part in the circumferential direction of the workpiece in which one end in the axial direction of the male screw is held by the rotating portion and the holding portion. A displacement meter for measuring the displacement between the generatrix of the outer peripheral surface of the screw shaft and the generatrix of the seat surface, and an axial direction of the workpiece Of the plurality of positions in the circumferential direction, at least the first position, the data indicating the two-dimensional shape based on the displacement measured by the displacement meter, and the reference line indicating the irradiation axis direction of the displacement meter, the screw shaft Temporary corresponding to the axial direction And a calculation control unit for calculating a first seat cushion angle is the angle of the seat surface relative to normal seat line perpendicular to the axial direction line.

  According to the above configuration, the displacement between the generatrix of the outer peripheral surface of the screw shaft of the workpiece and the generatrix of the seat surface is measured by the displacement meter using laser light, the data indicating the two-dimensional shape based on the displacement, Since the seating surface angle is calculated from the reference line indicating the irradiation axis direction, the seating surface angle can be automatically and accurately measured.

  In the configuration according to the present invention, preferably, the arithmetic and control unit outputs a calculated value of the first seating surface angle at the first position.

  According to the above preferred configuration, since the calculated value of the seating surface angle is output, the user can check the seating surface angle.

  In the configuration according to the present invention, it is preferable that the arithmetic control device is a two-dimensional device based on a displacement measured by the displacement meter at a second position that is 180 degrees different from the first position around the axial direction of the workpiece. A second seating surface angle that is an angle of the seating surface with respect to the normal seating surface line is calculated from data indicating a shape and the reference line, and the inclination direction of the seating surface with respect to the normal seating surface line is divided into positive and negative. In this case, the inclination direction of the seating surface is determined from the sign of the sum of the first seating surface angle and the second seating surface angle.

  According to said preferable structure, the inclination direction of a seat surface can be determined accurately.

  In the configuration according to the present invention, preferably, the average inclination amount of the seating surface is calculated from the absolute value of the first seating surface angle and the absolute value of the second seating surface angle.

  According to said preferable structure, the average inclination amount of a seat surface can be determined. Moreover, the inclination state of the seating surface can be determined with higher accuracy.

  In the configuration according to the present invention, preferably, the arithmetic control device is configured such that the seating surface is inclined so that an outer peripheral end of the seating surface is directed to one end side of the workpiece at the first position and the second position. The case where the seating surface is inclined so that the outer peripheral end of the seating surface is directed toward the other end side of the workpiece is the V-type, and the case where the inclination direction of the seating surface is 0 is the linear type. In this case, a pass determination is made when the seat surface is inclined to an inverted V shape or a linear shape, and a failure determination is made when the seat surface is inclined to a V shape.

  According to said preferable structure, it can be determined appropriately whether it is a work which can be used.

  In the configuration according to the present invention, it is preferable that the base has an upper surface parallel to the XZ plane, with the axial direction being the Y direction, the plane perpendicular to the Y direction being the XZ plane, and the gripping portion being the base An image projection unit that images the head or a head engaging adapter that is engaged with the head hole or the head hole of the head is provided on the upper side of the table so as to be rotatable about the axial direction. The angle of the seating surface with respect to the normal seating surface line is calculated according to a change in the dimension around the axis of the head or the head engaging adapter captured by the image projection unit.

  According to said preferable structure, the angle of a seat surface can be automatically measured according to the circumferential direction position of the workpiece | work determined by the shape of the head of a workpiece | work or a head hole.

  In the configuration according to the present invention, preferably, the image projection unit is disposed on one side in the Z direction with respect to the Y-direction center line of the workpiece, and outputs a parallel light beam, and the Y-direction center line of the workpiece. The projection shape which is arranged on the other side in the Z direction and receives the parallel rays from the light source and becomes a shadow of the workpiece has only the light receiving optical axis identical to that of the light source and parallel to the optical axis. A projection imaging camera of a telecentric optical system that forms an image on an imaging surface parallel to a plane and images the image.

  According to said preferable structure, the external shape of a workpiece | work can be acquired more accurately.

  The arithmetic and control unit is provided at a plurality of circumferential positions around the axial direction of the workpiece at which the width in the X direction of the head or the head engaging adapter is maximum or minimum from the projection shape captured by the projection imaging camera. The data indicating the two-dimensional shape is created, and the angle of the seating surface with respect to the normal seating surface line is calculated from the data.

  According to said preferable structure, the angle of a seat surface can be automatically measured according to the circumferential direction position of the workpiece | work determined by the shape of the head of a workpiece | work or a head hole.

  According to the screw shape automatic measuring system according to the present invention, the angle of the bearing surface of the screw that is the workpiece to be measured can be automatically and accurately measured.

It is a lineblock diagram of the screw shape automatic measurement system of an embodiment concerning the present invention, and is a front view of a screw shape automatic measuring device. It is a right view of the screw shape automatic measuring device shown in FIG. FIG. 2 is a top view of a part of the screw shape automatic measuring device of FIG. 1. It is a figure which shows the screw which is the holding part of the screw shape automatic measurement system of embodiment which concerns on this invention, and the measurement object workpiece | work hold | gripped. (A) is sectional drawing of a fastening chuck | zipper, (b) is sectional drawing of an adapter, (c) is a figure which shows the screw | thread of a workpiece | work to be measured. (D) is an exploded view of the adapter. (E) to (g) are top views corresponding to (a) to (c). It is an enlarged view of the adapter shown in FIG.4 (b). It is a flowchart which shows an example of the measurement procedure in the screw shape automatic measurement system of embodiment which concerns on this invention. It is a figure which shows the measurement location in the screw shape automatic measurement system of embodiment which concerns on this invention. (A) is a figure which shows the measurement location in a side view, (b) is a figure which shows the measurement location in a top view. It is a figure which shows the measurement of the crest diameter in the screw shape automatic measurement system of embodiment which concerns on this invention. (A) is a figure which shows the outline data along the axial direction of a workpiece to be measured, (b) is a figure which calculates | requires the regression line of the outline data of the peak part of (a), (c), It is a figure which shows the calculation method of a mountain diameter. It is a figure which shows the measurement of the trough diameter in the screw shape automatic measurement system of embodiment which concerns on this invention. (A) is a figure which shows the contour data along the axial direction of a workpiece to be measured, (b) is a figure which calculates | requires the regression line of the contour data of the trough part of (a), (c), It is a figure which shows the calculation method of a valley diameter. It is a figure which shows one example of the measuring method of neck length, (a) is a figure which shows two examples of the positional relationship of the workpiece | work fixed to the adapter, a 1st camera, and a light source, (b) is 1st. It is a figure which shows the image data acquired when the camera exists in the Pa1 position of (a), (c) is a figure which shows the image data acquired when the 1st camera is in the Pa2 position of (a). is there. It is a figure which shows the measurement range of the bus surface of a bearing surface and a screw shaft used at the time of calculation of the inclination angle of the bearing surface of the workpiece | work of a 1st example. (A) is a figure which shows the state which sets the circumferential direction position which measures a seat surface angle, after fixing a workpiece | work with a clamping chuck, when measuring the seat surface angle of the head of a workpiece | work. (B) is a figure which shows the detection position and detection width of a seat surface inclination in the AA cross section of the workpiece | work shown to (a). (C) is a figure which shows the state which determines the diagonal position of a head from the projection image of a workpiece | work when a workpiece | work is a hexagon bolt, (d) is a case where a workpiece | work is a hexagon socket head bolt. It is a figure which shows the state which determines the diagonal position of a head from the projection image of a workpiece | work. It is a figure which shows the state which measures the displacement of the outer peripheral surface of a seat surface and a screw shaft in the state in which the workpiece | work was hold | gripped by the holding part in the screw shape automatic measurement system of embodiment which concerns on this invention. (A) shows the irradiation position by a laser displacement meter in the side view of a workpiece | work, (b) is a top view of a workpiece | work. It is a figure which shows the state which measures the inclination angle of the seat surface of a workpiece | work in case the angular position of the workpiece | work of the 1st example around the axial direction is 0 degree | times. (A) is a view showing a workpiece and a reference angle θc, a first basic angle θ _C0 , a seating angle θ _0Z , a first seating surface angle α, and a seating surface average inclination amount γ, and (b) and (c) are It is a figure which shows the relationship of the one part angle taken out from (a). It is a figure which shows the state which measures the inclination angle of the seating surface of a workpiece | work in case the angle position around the axial direction of the workpiece | work of a 1st example is 180 degree | times. (A) is a view showing a workpiece and a reference angle θc, a second basic angle θ _C180 , a seating angle _θ180Z , a second seating surface angle β, and a seating surface average inclination amount γ, and (b) and (c) are It is a figure which shows the relationship of the one part angle taken out from (a). FIG. 13 (a) corresponding to FIG. 13 (a) showing a state of measuring the tilt angle of the seating surface of the workpiece when the angular position around the axial direction is 0 degree in the workpiece of the second example; FIG. 15B is a diagram corresponding to FIG. 14A and showing a state in which the tilt angle of the seating surface of the workpiece is measured when the angular position around the axial direction is 180 degrees. FIG. 13 (a) corresponding to FIG. 13 (a) showing a state of measuring the tilt angle of the seating surface of the workpiece when the angular position around the axial direction is 0 degree in the workpiece of the third example; FIG. 15B is a diagram corresponding to FIG. 14A and showing a state in which the tilt angle of the seating surface of the workpiece is measured when the angular position around the axial direction is 180 degrees.

  Embodiments according to the present invention will be described below in detail with reference to the drawings. In the following description, a screw is mainly used as a workpiece to be measured, and a bolt having a nominal size of M12 and a nominal length of 30 mm and having a hexagonal head is described for illustrative purposes. In addition to metric coarse threads, the types of screws are metric fine threads, pipe taper screws, pipe parallel threads, Whitworth coarse threads, unified coarse threads, unified fine threads, miniature screws, metric trapezoidal screws. Also good. The nominal length may be other than 30 mm. A head hole may be formed in the head. The head hole is a turning groove or turning hole for a tightening tool provided in the head. The head hole is a hexagonal star such as a slot (minus groove), cross hole, plus / minus hole, square hole, Torx (registered trademark) or its improved version Torx Plus (registered trademark) in addition to a hexagonal hole. It may be a hex lobe hole or a triangular hole which is a shape hole.

  The shapes, dimensions, materials, measurement locations and the like described below are examples for explanation, and can be appropriately changed according to the specifications of the screw shape automatic measurement system. Also, in the following, the same reference numerals are given to the same elements in all the drawings, and overlapping descriptions are omitted or simplified.

  FIG. 1 is a configuration diagram of a screw shape automatic measurement system 10 according to an embodiment. FIG. 2 is a right side view of the screw shape automatic measuring device 12 shown in FIG. FIG. 3 is a top view of a part of the screw shape automatic measuring device 12. The screw shape automatic measurement system 10 includes a screw shape automatic measurement device 12, an arithmetic control device 100, and a pneumatic control device 102. In the following description, the case where the clamping chuck 70 constituting the gripping portion 62 that is pneumatically controlled operates with the air pressure supplied from the pneumatic control device 102 will be described. However, the clamping chuck is controlled by the electric control device. It can also be an electric type. The screw shape automatic measuring device 12 includes a base 16 fixed on a gantry (not shown). The base 16 is disposed inside a case (not shown) provided on the gantry. An anti-vibration table may be used instead of the gantry. FIG. 1 is a front view of the screw shape automatic measuring device 12. FIG. 2 is a right side view of the inner portion of the case in the screw shape automatic measuring device 12. FIG. 3 is a top view of a part of the screw shape automatic measuring device 12 of FIG. 1-3, the orthogonal | vertical X direction, Y direction, and Z direction are shown. The XZ plane is a plane parallel to the top surface of the base 16 and the direction perpendicular to the top surface of the base 16 is the Y direction, which is the direction of gravity. The Z direction is the left-right direction in the front view of FIG. 1, and the X direction is the left-right direction in the right side view of FIG.

  In FIG. 1, although it is not a component of the screw shape automatic measuring device 12, the workpiece 8 to be measured is shown. The workpiece 8 is a bolt whose head is hexagonal with a nominal thread size of M12 and a nominal length of 30 mm. The axial direction of the workpiece 8 is a direction parallel to the Y direction. In other words, the Y direction is the axial direction of the workpiece 8.

  The screw shape automatic measuring device 12 is a gantry type. Specifically, a pillar member 18 is erected and fixed to an upper surface plate that forms the upper surface of the base 16 of the screw shape automatic measuring device 12. As shown in FIG. 3, the pillar member 18 has a substantially rectangular shape when viewed from the Y direction. A lift actuator 20 is attached to the front surface of the column member 18 (the front side surface in FIG. 1, the left side surface in FIG. 2, and the lower side surface in FIG. 3).

  The elevating actuator 20 includes an actuator case 20a fixed to the front surface (+ X direction side) of the column member 18, a Y motor 20b, a screw shaft (not shown), and a nut member (not shown). The actuator case 20a has a long shape along the Y direction which is the vertical direction. The case of the Y motor 20b is fixed to the upper surface of the actuator case 20a. A screw shaft extends along the −Y direction in the actuator case 20a and is rotatably supported by the actuator case 20a on the output shaft extending downward (−Y direction) from the Y motor 20b. Accordingly, the screw shaft is rotated by the rotation of the Y motor 20b. The driving of the Y motor 20b is controlled by the arithmetic and control unit 100.

  A Y table 22 is supported on the front side (+ X side) of the actuator case 20a so as to be movable in the Y direction. The Y table 22 includes a substantially flat table main body 22a along the YZ plane, and a light source table 22b fixed to the lower end of the −Y side end of the table main body 22a so as to extend in the + X direction. A light source 36 to be described later is fixed below the light source table 22b. In FIG. 1, the table body 22a of the Y table 22 is shown in sand for easy understanding.

  The nut member in the actuator case 20a meshes with the threaded portion of the screw shaft via a plurality of balls to constitute a ball screw mechanism. A part of the nut member protrudes toward the + X direction through a guide hole formed in the Y direction in the actuator case 20a and is fixed to the Y table 22. Thereby, the Y table 22 is moved along the Y direction with the rotation of the Y motor 20b.

  Further, as shown in FIG. 2, a linear scale type position sensor 24 is attached to the + Z side end of the actuator case 20a. That is, the position sensor 24 detects the position of the Y table 22 in the Y direction. The position sensor 24 optically or magnetically detects the position in the Y direction of the moving member attached to the Y table 22, for example. For example, in the magnetic position sensor 24, an exciting coil and a detection coil for passing current are attached to a moving member, and fixed side coils (not shown) are provided at a plurality of positions in the Y direction of the fixed side member fixed to the actuator case 20a. Be placed. When the moving member moves in the Y direction, the excitation coil and the detection coil of the moving member are in close proximity to one of the plurality of fixed coils, and the position of the moving member is detected from the voltage change at both ends of the detection coil. . A signal indicating the detection position of the moving member is transmitted to the arithmetic and control unit 100 (FIG. 1).

  An optical measuring device 32 is supported on the front (+ X direction) side of the Y table 22. The optical measuring device 32 optically measures the size and shape of the workpiece 8 in a non-contact manner. The optical measuring device 32 includes an image projection unit 34 for measuring the axial direction and the dimension around the axis of the work 8, and a head measurement unit 40 for measuring the size and shape of the head of the work 8 by image projection. And a laser displacement meter 50. The head measuring unit 40 may have a function of measuring the depth of the head hole when a head hole is formed on the upper surface of the head of the workpiece 8.

  The image projection unit 34 is disposed on one side in the Z direction (left side in FIG. 1) with respect to the center line of the workpiece 8 in the Y direction, and outputs a parallel light beam. And the first camera group 38 disposed on the other side (the right side in FIG. 1). The light source 36 is fixed to the lower side of the light source table 22b that is fixed to the front side of the Y table 22 so as to protrude in the X direction. As the light source 36, a light source having an appropriate light collimating means such as a collimator or a light source including a telecentric optical system can be used. On the front side of the Y table 22, a first camera Z moving table 35 is supported at the + Z side end (the right end in FIG. 1) so as to be movable in the Z direction. The first camera group 38 is attached to the front side of the first camera Z movement table 35 so as to be movable in the Y direction via the first camera Y movement table 25. In addition, the bracket 23 is fixed to a portion different from the light source 36 in the X direction on the lower side of the light source table 22b.

  And the laser displacement meter 50 is fixed to the board part 23a which inclines with respect to XY plane in the front-end | tip part (lower end part) of the bracket 23. FIG. The laser displacement meter 50 irradiates the workpiece 8 with laser light, and based on reception of the reflected light, a busbar on the outer peripheral surface of the screw shaft of the workpiece 8 and a busbar on the seating surface of the head (lower side in FIG. 1) Data indicating a two-dimensional shape including is created. This data is used in the arithmetic and control unit 100 to measure the angle of the head seat with respect to the reference line. The configuration of the laser displacement meter 50 will be described in detail later.

  A first camera Y movement table 25 is supported on the front side of the first camera Z movement table 35 so as to be movable in the Y direction. On the front side of the first camera Y moving table 25, three first cameras 39a, 39b, and 39c are mounted side by side in the Y direction so that the respective lenses face the -Z direction. Hereinafter, a case where there are three first cameras 39a, 39b, and 39c will be described, but the number is not limited to three, and may be one, two, or four or more. The three first cameras 39a, 39b, and 39c constitute a first camera group 38. The three first cameras 39a, 39b, and 39c have lenses with different magnifications. Hereinafter, the first cameras 39a, 39b, and 39c may be collectively referred to as the first camera 39 in some cases.

  The first camera Z movement table 35 is moved in the Z direction with respect to the Y table 22 by a first camera movement actuator 37. The first camera movement actuator 37 includes an electric motor and a ball screw mechanism (not shown), and a nut member (not shown) that meshes with the screw shaft of the ball screw mechanism through the ball by the rotation of the electric motor. Move in the Z direction. The first camera Z movement table 35 is fixed to the nut member, and the first camera Z movement table 35 is also moved in the Z direction by the movement of the nut member in the Z direction. The first camera Y moving table 25 moves in the Y direction so that the camera facing the workpiece 8 can be switched from among the three first cameras 39. Specifically, the first camera Y movement table 25 is moved in the Y direction with respect to the first camera Z movement table 35 by the camera switching actuator 45. The camera switching actuator 45 includes an electric motor 45a and a ball screw mechanism (not shown), and a nut member (not shown) that meshes with a screw shaft of the ball screw mechanism through a ball by the rotation of the electric motor 45a. Move in Y direction. The first camera Y movement table 25 is fixed to the nut member, and the first camera Y movement table 25 also moves in the Y direction by the movement of the nut member in the Y direction. When the operator operates a first switching operation unit (not shown), the arithmetic control device 100 controls the operation of the electric motor 45a. As a result, the electric motor 45a rotates, and the first camera facing the workpiece 8 in the −Z direction is switched from among the three first cameras 39. Then, one of the three first cameras 39 and the light source 36 face each other in the Z direction with a workpiece 8 that is a screw to be imaged interposed therebetween. The three first cameras 39 are telecentric optical projection imaging cameras. When one of the three first cameras 39 faces the workpiece 8 in the −Z direction, the same light reception as that of the light source 36 is received with respect to the projection shape that receives a parallel light beam from the light source 36 and becomes a shadow of the workpiece 8. Only a component having an optical axis and parallel to the optical axis is imaged on an imaging surface parallel to the XY plane. With the above configuration, the first camera 39 facing the workpiece 8 is automatically switched, so that it can be easily switched to a camera having a lens with an appropriate magnification corresponding to the size of the workpiece 8. Thereby, unlike the case of the configuration having only one first camera in the screw shape automatic measurement system, the operator has to manually replace the lens with one first camera in accordance with the size of the workpiece 8. Does not occur. For this reason, the problem which arises when exchanging a lens with one 1st camera, for example, a foreign material does not enter the inside of the 1st camera in the state where a lens was removed. As each first camera 39, a CCD camera using a CCD image sensor or a camera device using a CMOS image sensor can be used. As the electric motor 45a constituting the camera switching actuator 45, an AC servo motor or a stepping motor can be used.

  The head measurement unit 40 includes a second camera group 42 attached to the front side of the Y table 22 so as to be movable in the Z direction. Specifically, the second camera movement table 44 is supported at the + Y side end (upper end) of the Y table 22 so as to be movable in the Z direction. Three second cameras 43a, 43b, and 43c are mounted on the front side of the second camera moving table 44 so that the lenses are aligned downward in the Z direction. Below, the case where there are three second cameras 43a, 43b, and 43c will be described, but the number is not limited to three, and may be one, two, or four or more. The three second cameras 43a, 43b, and 43c constitute a second camera group 42. The three second cameras 43a, 43b, and 43c have lenses with different magnifications. Hereinafter, the second cameras 43a, 43b, and 43c may be collectively referred to as the second camera 43.

  Then, the second camera moving table 44 moves in the Z direction so that the camera facing the head of the workpiece 8 can be switched from among the three second cameras 43. Further, the three second cameras 43 are configured to be retractable from directly above the head of the workpiece 8 to the −Z side. Specifically, the second camera movement table 44 is moved in the Z direction with respect to the Y table 22 by the second camera movement actuator 46. The second camera movement actuator 46 includes an electric motor 46a and a ball screw mechanism (not shown), and a nut member (not shown) that meshes with the screw shaft of the ball screw mechanism via the ball by the rotation of the electric motor 46a. ) In the Z direction. The second camera movement table 44 is fixed to the nut member, and the second camera movement table 44 also moves in the Z direction by the movement of the nut member in the Z direction. When the operator operates a second switching operation unit (not shown), the arithmetic control device 100 controls the operation of the electric motor 46a. As a result, the electric motor 46 a rotates and the second camera that faces the head of the workpiece 8 in the −Y direction is switched from among the three second cameras 43. Each of the three second cameras 43 is a head imaging camera, and images the head of the workpiece 8 on an imaging surface parallel to the XZ plane as will be described later. The imaging data captured by the second camera 43 is transmitted to the arithmetic and control unit 100, and the arithmetic and control unit 100 can calculate head dimensions such as the diameter of the head and the width across flats of the head hole. it can. As the second camera 43, a CCD camera using a CCD image sensor or a camera device using a CMOS image sensor can be used. As the electric motor 46a constituting the second camera movement actuator 46, an AC servo motor or a stepping motor can be used. A ring-shaped illumination unit 190 is provided on the −Y direction side of each second camera 43 to illuminate the upper surface of the workpiece 8. The illumination unit 190 is supported on the front side of the −Z side end portion (left end portion in FIG. 1) of the Y table 22 so as to be movable in the Z direction by the illumination moving mechanism 192. The illumination movement mechanism 192 moves the illumination unit 190 in the Z direction by an illumination movement actuator (not shown). The illumination moving mechanism 192 is configured to be movable between an irradiation position that irradiates the illumination unit 190 around the upper side of the workpiece 8 and a position that is retracted from the irradiation position to the −Z side. The illumination moving mechanism 192 can be configured to include an electric motor and a ball screw mechanism, similarly to the moving actuators 37 and 46 described above.

  Further, the screw shape automatic measuring device 12 includes a gripping portion 62 that grips the workpiece 8. The gripping part 62 is provided on the upper side of the base 16 via the gripping rotation part 60 so as to be rotatable about the axial direction, and grips one axial end of the work 8 on the screw side. As shown in FIG. 4, the gripping part 62 includes an adapter 80 having a disk-shaped outer shape and a fastening chuck 70 that clamps and fixes the outer peripheral side surface of the adapter 80 at at least three points. The gripping rotation unit 60 includes a θ motor (not shown) that drives the fastening chuck 70 to rotate 360 degrees around the axial direction.

  The rotation operation of the θ motor is controlled by the arithmetic and control unit 100. As such a θ motor, an AC servo motor or a DC servo motor can be used. Further, the rotation of the θ motor is synchronized with the rotation of the gripping rotation unit 60. The rotation angle of the θ motor is detected by a rotary encoder (not shown). The detection signal of the rotary encoder is input to the arithmetic and control unit 100.

  FIG. 4 is an exploded view showing details of the gripping part 62. Here, detailed configurations of the clamping chuck 70 constituting the gripping part 62, the adapter 80 fixed by the clamping chuck 70, and the workpiece 8 gripped by the adapter 80 are shown. 4A to 4C are cross-sectional views of the fastening chuck 70, the adapter 80, and the workpiece 8, FIG. 4D is an exploded view of the adapter 80, and FIGS. The top view of each of the fastening chuck 70, the adapter 80, and the workpiece 8 is shown.

  The workpiece 8 includes a male screw part 2, a head part 4, and a neck lower part 3 between the male screw part 2 and the head part 4.

  The clamping chuck 70 includes three slide bases 74 that are movably disposed on the support base 72. In the initial state, the three slide bases 74 are retracted to the outer peripheral side of the support base 72. By operating the pistons 78a and 78b of the piston / cylinder mechanism with the air pressure supplied from the pneumatic control device 102 (FIG. 1), the three slide bases 74 are synchronized, and the outer peripheral side and the central axis side of the support base 72 It is driven to move between.

  Claw portions 76a, 76b, and 76c are attached to the three slide bases 74, respectively. The tip portions of the three claw portions 76a, 76b, and 76c are disposed so as to face the direction of the central axis of the support base 72, respectively. In the initial state, the claw portions 76 a, 76 b and 76 c are also retracted to the outer peripheral side of the support base 72. By moving the three slide bases 74 to the central axis side of the support base 72 in synchronization, the tip portions of the claw portions 76a, 76b, and 76c are synchronously moved to gather on the central axis side of the support base 72. . The three slide bases 74 are clamped by sandwiching and fixing the outer peripheral side surface of the adapter 80 while centering the adapter 80 arranged at the center of the support base 72 so as to match the position of the central axis. Thus, the clamping chuck 70 is a three-part chuck mechanism that is driven to move by air pressure between the retracted state and the tightening state.

  The centering clamping operation of the clamping chuck 70 is performed under the control of the arithmetic and control unit 100. The adapter 80 is clamped by the clamping chuck 70 at the tip portions of the three claw portions 76a, 76b, and 76c. The holding of the outer peripheral side surface of the adapter 80 may be performed at least at three points. For example, it is good also as a structure which clamps the outer peripheral side surface of the adapter 80 by two claw parts which mutually make the shape of the front-end | tip part of a nail | claw part mutually opposing. In this case, the outer peripheral side surface of the adapter 80 is clamped at four points.

  FIG. 5 is an enlarged view of the adapter 80 shown in FIG. The adapter 80 has a disk-shaped outer shape sandwiched between the fastening chucks 70 and can be fixed so that the axial direction of the workpiece 8 is not shaken when the distal end portion of the male screw portion 2 of the workpiece 8 is screwed. A workpiece fixing jig having a female screw having a predetermined meshing length at the center of one end face.

  The adapter 80 is configured by integrating a ring gauge 82 and a holder 86. In the ring gauge 82, the tip end portion of the male thread portion 2 of the workpiece 8 is screwed with a predetermined engagement length. The holder 86 has a disk-shaped outer shape that is clamped by the fastening chuck 70.

  The ring gauge 82 is a member having a disc shape and having a reference female screw 83 cut along its central axis. The reference female screw 83 is a female screw having a predetermined meshing accuracy corresponding to the thread size of the male thread portion 2 of the workpiece 8. As the ring gauge 82, a screw outer diameter gauge used for screw inspection can be used as it is. When the standard thread outer diameter gauge is M12, an 8-pitch reference female thread 83a is engraved. Since 1 pitch = 1.75 mm, the ring gauge 82 is manufactured so that, for example, the thickness as a design value is 8 pitch = 14.00 mm. The reference female screw 83 does not have an incomplete screw portion.

  The distal end portion of the male thread portion 2 of the workpiece 8 is screwed with a predetermined engagement length from the upper surface side which is one end surface side of the ring gauge 82. The predetermined meshing length is set to such an extent that the workpiece 8 does not shake in the axial direction when the tip of the male thread portion 2 of the workpiece 8 is screwed into the reference female screw 83 of the ring gauge 82 and meshed. Although it is preferable that the amount of shake of the workpiece 8 in the axial direction is zero, it is permissible as long as the measurement accuracy of various dimensions of the workpiece 8 is not affected. If the workpiece 8 is a non-defective product, if the effective thread portion of the male thread portion 2 of the workpiece 8 is engaged with the reference female thread 83a of the ring gauge 82 by about one pitch, the axial deflection of the workpiece 8 is substantially within the allowable range. It will fit. Since the male thread portion 2 of the workpiece 8 has incomplete thread portions corresponding to two pitches at the maximum, the predetermined meshing length as the screwing amount of the workpiece 8 is (the length corresponding to the number of pitches of the incomplete thread portion + It is preferable to set the length as long as possible as compared to the length of one pitch of the complete thread portion.

  In the following, a predetermined meshing length as a design value = a length corresponding to three pitches of the male thread portion 2 of the workpiece 8 = 5.25 mm. The predetermined meshing length is set to a length corresponding to 3 pitches, which is an integral multiple of the length of 1 pitch, because the screwing depth of the tip of the male threaded portion 2 of the workpiece 8 into the ring gauge 82a is 1 pitch. This is to make it approximately the same as an integer multiple. The workpiece 8 is a metric coarse screw with a nominal length of M12 and a nominal length of 30 mm. According to Japanese Industrial Standard values, the incomplete threaded portion of the male threaded portion 2 has a maximum of 2 pitches. Therefore, one pitch is added to the maximum two pitches, and the predetermined meshing length is set to a length corresponding to three pitches so that at least one pitch can be meshed with the complete thread portion.

  In the case of the work 8 with a low quality level, the incomplete thread portion may be 2 pitches or more, and even if the meshing length is 3 pitches, the work 8 may sway in the axial direction. In such a case, the predetermined meshing length is increased from the length of 3 pitches to the length of 1 pitch as a unit. For example, the predetermined meshing length is 4 pitches or 5 pitches. On the contrary, in the case of a screw processed for high accuracy and the incomplete thread portion can be accommodated in 1 pitch or less, the predetermined meshing length is changed from a length of 3 pitches to a length unit of 1 pitch. It can be shortened. For example, the predetermined meshing length may be a length corresponding to two pitches. Adjustment of the predetermined meshing length in increments of 1 pitch is performed by increasing or decreasing the number of spacers 84a. The predetermined meshing length described above is a design length. Actually, the axial length such as the neck length of the workpiece 8 is not calculated based on the design length, but the internal thread 92 of the ring gauge 82 is connected to the male thread 92 of the holder 86. In a state where the ring gauge 82 is screwed in until it comes into contact with the upper surface of the holder 86, the axial gap length in which the threaded portion of the workpiece 8 can be screwed in the reference female screw 83 is measured using a dial gauge or the like. Then, the increase / decrease amount of the gap length obtained by actual measurement with respect to the designed target gap length is pre-registered as a preset in the arithmetic and control unit 100 as an offset value. On the other hand, a ring gauge 82 and a holder 86 having a predetermined shape and size are prepared according to the size of the workpiece 8. When the workpiece 8 is actually measured, a combination of the ring gauge 82 and the holder 86 is selected in advance according to the size of the workpiece 8, and information representing the combination is input to the arithmetic control device 100. Thereby, the arithmetic and control unit 100 calculates the axial length such as the neck length of the workpiece 8 using the offset value and the target gap length registered in advance.

  The holder 86 is a disk-shaped member having an upper surface that is one end surface from which the external thread 92 that engages with the reference female thread 83 of the ring gauge 82 protrudes. If the side on which the male thread portion 2 of the workpiece 8 is screwed into the ring gauge 82 is the upper surface side of the ring gauge 82, the male thread 92 of the holder 86 is screwed from the lower surface side of the ring gauge 82. The holder 86 includes a sandwiching ring portion 88 and a stopper flange 90 having an outer diameter larger than that of the sandwiching ring portion 88. Even if the nominal dimensions of the workpiece 8 are different, it is preferable that the clamping ring portion 88 has the same outer diameter because the clamping chuck 70 can be standardized. When the lower surface, which is the end surface on the −Y direction side, of the stopper flange 90 abuts against the upper surfaces of the three claws 76 a, 76 b, 76 c of the clamping chuck 70, the holder 86 is clamped by the clamping chuck 70. Positioning in the Y direction is performed accurately.

  The male screw 92 protrudes from the upper surface, which is one end surface of the stopper flange 90 of the holder 86, with a preset protrusion amount.

  The length of the male screw 92 screwed into the reference female screw 83 of the ring gauge 82 is {(thickness of the ring gauge 82)-(predetermined meshing length with which the male thread portion 2 of the workpiece 8 meshes with the ring gauge 82). } Is set accurately. The protruding amount of the external thread 92 is set with the aim of being an integral multiple of the pitch in design. For example, in the reference female thread 83a of the ring gauge 82a, the design axial gap length of the part into which the upper work 8 (FIG. 4) can be screwed is 2 pitches or 3 pitches of the male thread part 2 of the work 8. The holder 86 is manufactured so as to have a length corresponding to n pitches such as n (n is a positive integer).

  When screwing the male thread portion 2 of the workpiece 8 into the ring gauge 82, the male thread 92 of the holder 86 is engaged with the reference female thread 83 of the ring gauge 82 from the lower surface side of the ring gauge 82. Then, the tip of the male thread portion 2 of the workpiece 8 is screwed into the reference female screw 83 of the ring gauge 82 from the upper surface side of the ring gauge 82. As a result, the distal end portion of the male screw portion 2 of the workpiece 8 stops at the distal end of the male screw 92 of the holder 86. The threading depth of the tip of the male thread 2 of the workpiece 8 into the ring gauge 82 is {(the thickness of the ring gauge 82) − (the length by which the male thread 92 of the holder 86 is screwed into the ring gauge 82)}. is there.

  Here, the ring gauge 82 and the male thread 92 of the holder 86 constituting the adapter 80 may have different thicknesses and thread portions depending on the type of the workpiece 8. On the other hand, the sandwiching ring portion 88 and the stopper flange 90 have a common shape and dimensions regardless of the type of the workpiece 8.

  Returning to FIG. 1, the arithmetic and control unit 100 controls the operation of each element such as an actuator and a motor constituting the screw shape automatic measuring device 12 and the pneumatic control device 102 as a whole, and the axial direction of the workpiece 8 and The dimension around the axis is calculated, and the calculated result is transmitted to the output device 104 such as a printer. The output device 104 has a function of printing out an inspection document. The arithmetic and control unit 100 can be configured with an appropriate computer. The output device may be a display that displays the contents of the inspection document on a screen, or a recording device that records the contents of the inspection document on a recording medium. The output device may output or transmit a file in which the contents of the inspection document are recorded.

  The arithmetic and control unit 100 has functions of head dimension measurement, neck round radius measurement, cylinder diameter measurement, screw diameter measurement, cylinder length measurement, neck length calculation, bending measurement, and measurement result output. These functions can be realized by software executed by the arithmetic and control unit 100. Specifically, the functions can be realized by executing a screw automatic measurement program. Some of these functions may be realized by hardware. Furthermore, the arithmetic and control unit 100 includes a two-dimensional shape creation unit 110 and a seating surface angle calculation unit 112, which will be described later, in order to calculate the angle of the seating surface 7 (see FIG. 6B) of the head 4 of the workpiece 8.

  The operation of the automatic thread shape measurement system 10 described above, particularly each function of the arithmetic and control unit 100, will be described in detail with reference to FIGS. 6A to 9B. FIG. 6A is a flowchart illustrating an example of a measurement procedure in the screw shape automatic measurement system 10 of the embodiment. FIG. 6B is a diagram illustrating measurement points of the workpiece 8 in the screw shape automatic measurement system 10. FIG. 6B (a) shows the measurement points in the side view, and FIG. 6B (b) shows the measurement points in the top view.

  When the workpiece 8 is measured, the screw shape automatic measurement system 10 is first initialized. In the initialization, the power is turned on, the pneumatic control device 102 is started, and the arithmetic control device 100 is set to the initial state. As a result, the Y table 22 returns to a predetermined initial Y position. The initial Y position is set to a position sufficiently higher along the Y direction than the tip position of the grip portion 62. The gripping part 62 returns to a predetermined initial angular position. The three claw portions 76a, 76b, and 76c of the fastening chuck 70 return to the retracted state.

  When the initialization is completed, the work 8 is set in the adapter 80 (S10). Next, the adapter 80 is set on the fastening chuck 70 of the grip portion 62. As described with reference to FIGS. 4 and 5, the workpiece 8 is fixed with the distal end portion of the external thread portion 2 held by the holding portion 62. At this time, the distal end of the male screw portion 2 comes into contact with the distal end of the male screw 92 of the holder 86 screwed into the adapter 80 and stops. Next, the adapter 80 that grips the workpiece 8 is set in a space between the three claw portions 76a, 76b, and 76c in the retracted state of the tightening chuck 70 (S11). The processing so far is performed manually by the operator.

  When the workpiece 8 is set on the gripping portion 62, the operator presses a fastening fixing button or the like, whereby the arithmetic control device 100 issues a command to the pneumatic control device 102, and the clamping chuck 70 of the gripping portion 62 A predetermined tightening air pressure is supplied to the piston / cylinder mechanism. As a result, the three claw portions 76a, 76b, and 76c are synchronously moved to the central axis side of the support base 72, and the work 8 is firmly tightened and fixed. From this state, measurement of the shape dimension of the workpiece 8 is started.

  Thereafter, head dimension measurement, neck round radius measurement, cylinder diameter measurement, screw diameter measurement, cylinder length measurement, neck length calculation, and bending measurement are sequentially performed. These processes are executed by the arithmetic and control unit 100. Specifically, the arithmetic control device 100 controls each actuator such as the first camera movement actuator 37, the camera switching actuator 45, the lift actuator 20, the second camera movement actuator 46, and the θ motor. A robo cylinder may be used as one or more of the lift actuator 20, the first camera movement actuator 37, the camera switching actuator 45, and the second camera movement actuator 46. For example, the ROBO Cylinder is an integrated product incorporating a ball screw, a motor, and a linear guide mechanism, and is configured to be capable of positioning and position reading.

  In FIG. 6A, the measurement process from S <b> 12 to S <b> 21 is performed using the first camera 39, as indicated by the portion surrounded by the alternate long and short dash line G <b> 1. On the other hand, in FIG. 6A, the measurement process of S <b> 22 indicated by the portion surrounded by the alternate long and short dash line G <b> 2 is performed using the second camera 43.

  First, since the type or parameter corresponding to the axial length of the workpiece 8 is set in advance in the arithmetic and control unit 100, the first camera 39 stands by at a position where it can be easily measured according to the axial length. . Then, each part is measured by moving the workpiece 8 from the upper side to the lower side by the first camera 39. First, head dimension measurement (S12, S13) is performed. At this time, first, the first camera 39 is selected by the operation of the camera switching actuator 45, and based on the imaging data of the workpiece 8 acquired by the selected first camera 39, the dimensions of the workpiece 8 in the axial direction and around the axis. Is calculated. Further, the first camera 39 is retracted to the right side of FIG. 1 by the first camera moving actuator 37 in a state before the measurement, and is moved to the left side of FIG. 1 immediately before the measurement.

  What is necessary for the projection shape data of the work 8 imaged by the first camera 39 is data at a position where the white data is changed to the black data. The workpiece 8 has a cylindrical shape on the XY plane or a spiral screw engraved on the male screw portion 2 and the head portion 4.

  Then, the arithmetic and control unit 100 performs contour data calculation. Specifically, the contour tracking process is performed using the black-and-white boundary of the projection shape data of the workpiece 8 as the contour of the projection shape of the workpiece 8 to calculate primary screw contour profile data. Then, a secondary screw contour profile is calculated by performing a smoothing process for removing data that becomes abnormal when viewed from the cross-sectional pattern of the workpiece 8 as noise. The noise-removed screw contour profile is used as contour data for subsequent calculation of various dimensions.

  For example, in the contour data calculation, in order to increase the resolution of the contour data, the projection shape data of the work 8 imaged by the first camera 39 is converted into two-dimensional bitmap data having an arbitrary position resolution. For example, if the pixel resolution on the imaging surface of the first camera 39 is about 8 μm, one pixel is divided into 8 × 8 sub-pixels and converted into a two-dimensional bitmap having a position resolution of 1 μm. In this way, a two-dimensional bitmap having a sufficient position resolution can be obtained, and thereafter, contour tracking processing and noise removal processing are performed using the data of the two-dimensional bitmap.

  The contour tracking process is a process for tracking a black-and-white boundary in a two-dimensional bitmap, and searches for the position of the next continuous black data from one black data position according to a predetermined rule to form a continuous line.

  Then, smoothing processing for removing noise is performed by applying a predetermined noise judgment standard to the contour profile data obtained by the contour tracking processing, and contour data indicating the screw contour profile of the workpiece 8 can be calculated.

  When the contour data calculation process is completed, various dimension measurements are performed using the projection shape data of the workpiece 8 acquired by the first camera 39.

  Specifically, as shown in FIG. 6B, the diameter dk of the head 4 is measured using the projection shape data of the head 4 of the work 8. Here, the operation of the Y motor 20b is controlled so that the entire length of the head 4 in the X direction is included. Then, the θ motor is driven, the workpiece 8 is rotated 360 degrees around the axis, 360 degrees corresponding to one rotation is multiplied by 360, and, for example, 360 sampled projection shape data is used to obtain the maximum diameter dk. Find the value. The maximum value of the diameter dk is measured as the head diameter measured for the diagonal line connecting the hexagonal vertex positions of the head 4 (S12).

Next, the Y position Y _{10 on} the upper surface of the head 4 and the Y position Y ₉ on the lower surface are measured. Here, the position in the Y direction of the contour data sampled by multiplication by 360 is obtained on the two-dimensional bitmap with respect to the upper surface of the head 4 acquired by the first camera 39 while rotating the workpiece 8 around the axis 360 degrees. . For example, a precise displacement of Y ₁₀ is calculated in units of 1 μm. At this time, the contour data samples image data synchronized with the pulse of the output signal of the rotary encoder that detects the rotation angle of the θ motor. In each contour data, for precise displacement of the calculated Y _10, the maximum value and the minimum value and the average value, by adding the high-precision data value of the position sensor 24 to the maximum value of Y _10, the minimum Value and average value.

Similarly, data from the position sensor 24 is acquired for the lower surface of the head 4. Next, while the workpiece 8 is rotated around the axis, the position in the Y direction of the contour data of the lower surface of the head 4 acquired by the first camera 39 is obtained on a two-dimensional bitmap, for example, a reference value of Y ₉ in 1 μm units Calculate the precise displacement from. Further, for each sampling data, the maximum value, the minimum value, and the average value are obtained for the calculated precise displacement of Y ₉ , and the data value corresponding to the reference value from the position sensor 24 is added to this, and Y The maximum value, minimum value, and average value of ₉ . Then, the maximum value, the minimum value, and the average value of the head height k (FIG. 6B) are calculated from the maximum value, the minimum value, and the average value of Y ₁₀ and Y ₉ and measured (S13). At this time, only the average value of the head height k may be calculated from the average value of Y ₁₀ and Y ₉ .

  When the measurement of the height dimension of the head 4 is completed, the Y table 22 is lowered in the Y direction, and the radius measurement of the rounded part under the neck (S14) is performed. The neck round radius is the radius of curvature at the lower neck between the head 4 and the external thread 2. Specifically, the contour data of the neck lower part 3 of the workpiece 8 acquired by the first camera 39 is obtained on the two-dimensional bitmap using the method described in the calculation of the screw contour profile.

  At this time, the work 8 is rotated 360 degrees around the axis. Then, with each sampled contour data, two straight lines on both sides of the neck rounded part are obtained by a regression line, and toward the angle division line that bisects the angle formed by the two straight lines, the two straight lines and the neck rounded part are obtained. A perpendicular line is drawn from each of the two contact points with the arc. And the average value of the length of each perpendicular is calculated, and the average value of the length of the perpendicular calculated by each data is calculated as the value of the neck radius part. At this time, the maximum value, the minimum value, and the average value of the neck radius may be calculated from each contour data.

  Next, for the diameter da of the round transition circle of the head 4, an average value is calculated from the contour data of the sampled head 4. The seating surface 7 is linear in the contour data, and the diameter da of the rounding transition circle is measured from the X-direction distance between the two straight portions on both sides in the X direction on the lower surface of the head 4 and the rounded portion under the neck. (S15). At this time, the maximum value, the minimum value, and the average value of the diameter da may be calculated from each contour data.

  Next, the diameter ds of the cylindrical portion 9 is measured (S16). The cylindrical portion 9 is a shaft portion in which no thread portion is formed between the head 4 and the external thread portion 2 in the work 8. At this time, the average value of the cylindrical portion diameters ds is calculated from the sampled contour data of the cylindrical portion 9. In this case, the maximum value, the minimum value, and the average value of the diameter ds of the cylindrical portion 9 may be calculated from each contour data.

Next, as a screw diameter measurement, a crest diameter measurement and a trough diameter measurement are performed (S17). The thread diameter is the outer diameter dimension of the thread, and the valley diameter is the inner diameter dimension of the thread valley. The crest diameter measurement and the trough diameter measurement are performed at one place or a plurality of places along the axial direction of the external thread portion 2 of the workpiece 8. FIG. 6B shows one Y position Y ₈ where the peak diameter measurement and the valley diameter measurement are performed. The number of measurement points can be determined as appropriate depending on the length of the external thread 2 of the workpiece 8 in the Y direction.

  FIG. 7 is a diagram showing a method for measuring a mountain diameter. FIGS. 7A and 7C are diagrams showing the contour data of the male thread 2 of the workpiece 8 on the two-dimensional bitmap, and FIG. 7B is an enlarged view of a part of FIG.

The measurement algorithm of the mountain diameter measurement is performed by the following processes (1) to (5).
(1) The image data synchronized with the pulse of the output signal of the rotary encoder is sampled at every predetermined angle around the workpiece 8 in the axial direction. For example, sampling is performed by multiplying 360 degrees by 360. For example, 360 pieces of image data are sampled per one rotation of the work.
(2) The sampled data is binarized as described above, and filtering is performed. Such process, as shown by Y ₈ in Figure 6B, may be made to set the rectangular area in a portion of the male screw portion 2 in advance teaching. FIG. 7A shows two contour data 170 and 171 of the male thread portion 2 of the workpiece 8. The two contour data 170 and 171 are data indicating contour shapes on both the left and right sides of the male thread portion 2 of the workpiece 8.
(3) A regression line 172 is drawn on the outer shape of the external thread 2 represented by the contour data on one side in the left-right direction (for example, the left side in FIG. 7A) of the two contour data. FIG. 7B is a partially enlarged view of FIG. 7A, and shows a method for obtaining the regression line 172 of the contour data 170 using this. The regression line 172 is a straight line that passes through the average position at a plurality of edges that are a plurality of peak portions and a valley bottom point of the male thread portion 2.

  (4) After obtaining the regression line 172, a perpendicular line 173 is drawn on the contour data 170 on the outer diameter side (left side in FIG. 7B) of the entire contour data 170 with respect to the regression line 172. A distance a between the perpendicular line 173 and the intersection of the outer diameter side contour data 170 is obtained. Such a perpendicular 173 is scanned in units of pixels in the Y-axis direction to obtain the maximum value A of the distance a in a set range such as a rectangular range. The maximum value A of the distance a is a value indicating the position of the peak portion on the outermost diameter side in the contour data 170 when viewed from the regression line 172.

  (5) Next, as shown in FIG. 7C, a perpendicular line 173 is drawn from the regression line 172 toward the contour data 171 on the other side in the left-right direction (for example, the right side in FIG. 7C). Then, the distance b from the regression line to the edge when the perpendicular line 173 contacts the edge of the peak or valley is obtained. Such a perpendicular 173 is scanned in units of pixels in the Y-axis direction, and the maximum value B of the distance b in the set range is obtained. FIG. 7C shows only a part of the vertical lines 173 to be scanned. The maximum value B of the distance b is a value indicating the position of the peak portion on the outermost diameter side in the contour data 171. Since the mountain diameter is the outer diameter of the mountain portion of the external thread portion 2 of the work 8, it is calculated as the sum (A + B) of the maximum value A of the distance a and the maximum value B of the distance b.

  As described above, (A + B) is obtained based on a plurality of image data synchronized with the pulses of the rotary encoder. When the value of (A + B) of each image data is obtained, the maximum value, the minimum value, and the average value are set as the measured values of the mountain diameter at the measurement location. Only the average value may be calculated as the measured value of the mountain diameter.

  FIG. 8 is a diagram illustrating a valley diameter measurement method. Similarly to FIG. 7, FIGS. 8A and 8C are diagrams showing the contour data of the male thread portion 2 of the workpiece 8 on the two-dimensional bitmap, and FIG. 8B is a partially enlarged view of FIG. FIG. FIG. 8A shows the same two contour data 170 and 171 as in FIG. The valley diameter measurement is similar to the mountain diameter measurement, and (1) to (3) are the same among the processes (1) to (5) described in the mountain diameter measurement. After the processes (1) to (3), the processes (4a) to (5a) are performed.

  (4a) After obtaining the regression line 172, a perpendicular line 177 is drawn on the contour data 170 on the inner diameter side (right side in FIG. 8B) of the entire contour data 170 with respect to the regression line 172. The distance c between the perpendicular line 177 and the intersection of the inner diameter side contour data 170 is obtained. Such a perpendicular line 177 is scanned in units of pixels in the Y-axis direction, and the maximum value C of the distance c in the set range is obtained. The maximum value C of the distance c is a value indicating the position of the valley bottom point located closest to the inner diameter side in the contour data 170 when viewed from the regression line 172.

  (5a) Next, as shown in FIG. 8C, a perpendicular line 177 is drawn from the regression line 172 toward the contour data 171 on the other side in the left-right direction (for example, the right side in FIG. 7C). Then, a distance d from the regression line to the edge when the perpendicular 177 contacts the edge of the peak or valley is obtained. Such a perpendicular line 177 is scanned in units of pixels in the Y-axis direction, and the minimum value D of the distance d in the set range is obtained. FIG. 8C shows only a part of the vertical lines 177 to be scanned. The minimum value D of the distance d is a value indicating the position of the valley bottom point that is closest to the inner diameter side in the contour data 171. Since the valley diameter is the minimum outer diameter of the valley portion of the male thread portion 2 of the workpiece 8, it is calculated as (D−C), which is the difference between the maximum value C of the distance c and the minimum value D of the distance d. .

  As described above, (DC) is obtained based on a plurality of image data synchronized with the pulses of the rotary encoder. When the (DC) value of each image data is obtained, the maximum value, the minimum value, and the average value are used as the measured values of the valley diameter at the measurement location. Only the average value may be calculated as the measured value of the valley diameter.

Further, when the measured value of the peak diameter and the measured value of the valley diameter are calculated, the effective diameter is calculated. The effective diameter is calculated by the following equation (1) based on the standard of JISB0205, for example.
(Effective diameter) = (valley diameter) + ((crest diameter) − (valley diameter)) × 2/5 (1)

  For the effective diameter, the maximum value, the minimum value, and the average value are calculated. Only an average value may be calculated as the effective diameter. The effective diameter may be calculated by another calculation formula such as (effective diameter) = (mountain diameter + valley diameter) / 2. In this case, the effective diameter is calculated based on the calculation formula. . Thus, according to the present system, the effective diameter can be easily measured, unlike the case where the effective diameter is measured by the three-needle method.

  Next, measurement of the length Ls of the cylindrical part without a screw (S18) and measurement of the length Lg of the cylindrical part (S19) are performed. The length Ls of the cylindrical portion without the screw is the distance from the intersection of the cylindrical portion 9 and the tapered portion connected from the screw portion to the seating surface 7 of the head 4, and similarly to the measurement processing of the head height k, It is measured by obtaining the Y-direction position between the seat surface 7 and the lower end of the cylindrical portion 9. The length Lg of the cylindrical portion is the distance between the seat surface 7 and the start position of the complete thread portion of the external thread portion 2, and the length Lg is also the upper end position of the complete thread portion of the seat surface 7 and the external thread portion 2. It is measured by calculating | requiring the Y direction position. Note that the lengths Ls and Lg are measured using a so-called bare workpiece image processing method in which an image is used without attaching an upper ring gauge to the upper side of the screw shaft of the workpiece 8, and on the upper side of the screw shaft. There is a method of measuring by attaching a thread ring gauge. The thread ring gauge has a ring shape and is formed with a threaded hole extending in the axial direction at the center. In the method of measuring by attaching a screw ring gauge to the screw shaft, the screw ring gauge (not shown) is directed from the tip of the screw shaft (lower end of FIG. 6B) to the upper side of FIG. 6B with the workpiece 8 removed from the adapter 80. Screw). As a result, the thread ring gauge stops at the start position of the complete thread of the external thread portion 2 (the upper end position in FIG. 6). Then, for example, the Y-direction position between the position where the screw ring gauge is fitted into the workpiece 8 and stopped and the seat surface 7 of the head 4 is acquired by image capturing, and the distance between these two Y-direction positions is measured. Thus, the length Lg is measured. For example, at the time of measurement, the workpiece can be removed from the adapter in the first, second,... Cycle, and a thread ring gauge can be attached in the cycle for measurement. After completing the preset cycle, the final measurement value of the length Lg can be determined comprehensively.

Next, the length under the neck is measured (S20). The neck length L is a distance from the seat surface 7 of the workpiece 8 to the tip of the external thread portion 2. In this measurement, the Y position Y _{1 on} the upper surface of the ring gauge 82 of the adapter 80 that holds the tip of the external thread 2 is measured. Specifically, it can be performed in the same procedure as the measurement of the Y position Y _{10 on} the upper surface of the head 4 and the Y position Y ₉ on the lower surface already described. That is, the operation of the Y motor 20b is controlled so that the contour data indicating the upper surface of the ring gauge 82 enters the imaging surface of the first camera 39, and the Y ₁ data value is acquired by the position sensor. Next, the Y-direction position of the contour data sampled by multiplication of 360 on the upper surface of the ring gauge 82 acquired by the first camera 39 is obtained on the two-dimensional bitmap while rotating the work 8 around the axis 360 degrees. For example, the displacement of a precise value of Y ₁ is calculated in units of ₁ μm. For each contour data, the maximum value, the minimum value, and the average value are calculated for the calculated precise value of Y ₁ , and the data value of the position sensor 24 is added to this value to obtain the maximum value, minimum value, and average of Y _1. Value.

Next, the values of the Y positions Y ₉ and Y ₁ that have already been measured and the meshing length between the reference female thread 83a of the ring gauge 82 and the tip of the external thread 2 of the work 8 are offset values based on actual measurements. Based on the corrected value L1, the neck length L of the workpiece 8 is calculated. In calculating the neck length L, the maximum value, the minimum value, and the average value of the neck length L are calculated based on the maximum value, the minimum value, and the average value of Y ₉ and Y ₁ , respectively. At this time, the average value of the neck length L may be calculated from the average value of Y ₉ and Y ₁ .

Further, the measurement of the length under the neck can be performed as follows without directly obtaining the Y positions Y _{9 and} Y ₁ . FIG. 9 is a diagram illustrating an example of a method for measuring the length under the neck. FIG. 9A is a diagram showing two examples of the positional relationship between the workpiece 8 fixed to the adapter 80, the first camera 39, and the light source 36, and FIG. 9B is a diagram illustrating the first camera 39 at the Pa1 position in FIG. It is a figure which shows the image data acquired at a certain time. FIG. 9C is a diagram illustrating image data acquired when the first camera 39 is at the Pa2 position in FIG.

  In the example shown in FIG. 9, the Y position of the first camera 39 fixed to the Y table 22 and selected from the detection signal of the position sensor 24 is detected. When the Y position of the first camera 39 is Pa1 in FIG. 9, the distance from the origin set on the lower side to the Pa1 position is E1. At this time, the first camera 39 acquires monochrome image data shown in FIG. 9B. Further, when the Y position of the first camera 39 is Pa2 in FIG. 9, the distance from the origin O to the Pa2 position is E2. At this time, the first camera 39 acquires monochrome image data shown in FIG. In FIG.9 (c), the shape of the peak part and trough part of the external thread part 2 is not shown, but is shown in linear form.

  Then, the arithmetic and control unit 100 determines the distance H1 from the lower end of the image data to the seat surface 7 for the Y position of the seat surface 7 that is the head neck position from the image data when the first camera 39 is at the Pa1 position. Ask. Further, the arithmetic and control unit 100 determines the distance H2 from the lower end of the image data to the upper end of the coupling position with respect to the Y position at the upper end of the coupling position between the adapter 80 and the workpiece 8 from the image data when the first camera 39 is at the Pa2 position. Ask for.

And the neck length L is calculated | required by following (2) Formula. At this time, the rotation angle of the workpiece 8 when the first camera 39 is at the Pa1 position and the rotation angle of the workpiece 8 when the first camera 39 is at the Pa2 position are the sampling pulses in the same row during one rotation. The measured values of the distances H1 and H2 are used.
L = E1-E2 + (H1-H2) + L1 (2)

  Further, in the expression (2), a value L1 corrected with an offset value based on actual measurement is used for the meshing length between the reference female thread 83 of the ring gauge 82 and the tip of the male thread 2 of the workpiece 8. Thereby, the neck length L can be measured. For the head height k in S13, the cylindrical portion length Ls in S18, and the cylindrical portion length Lg in S19, the first camera 39 arranged at a different Y position is the same as the measurement method of the neck length L in FIG. It can measure from the acquired image.

  Subsequently, the bending of the workpiece 8 is measured (S21). For example, bending is performed by connecting the radial center of the screw shaft in the upper and lower images among the images photographed at the plurality of positions in the axial direction of the screw shaft by the first camera 39, for example, the upper, middle, and lower three positions. In the intermediate image, the deviation of the center of the screw shaft in the radial direction is set as the maximum deflection width. Then, the bending is calculated as the sum of the maximum deflection width and the screw diameter at the maximum deflection width position. The maximum runout width may be calculated as the maximum value of the runout width in the lateral direction of the center line by obtaining the centerline of the screw shaft from the screw shaft image.

  Next, the two-sided width measurement of the head 4 is performed (S22). At this time, the first camera 39 is retracted to the right side of FIG. Then, the second camera moving table 44 is moved by driving the second camera moving actuator 46, thereby moving the selected second camera 43 directly above the head 4 of the work 8 along the Z-axis direction. . At the same time, or before and after this, the illumination movement mechanism 192 moves the illumination unit 190 to the irradiation position where the upper side of the workpiece 8 is irradiated. Then, the Y table 22 is lowered so that the focal position of the second camera 43 is exactly the position of the upper surface of the head 4 of the workpiece 8. Then, the imaging data of the shape of the head 4 of the work 8 is acquired by the second camera 43, the imaging data is binarized, and the two-surface width dimension Sa (FIG. 6B) of the head 4 using an edge detection method or the like. Is calculated. The dihedral width dimension Sa is a dimension between two opposite sides of the hexagon in the head 4 of the workpiece 8. At this time, unlike a black and white projection image acquired by the first camera 39, an image obtained by reflection of light is acquired. After the two-surface width measurement is completed, the second camera movement table 44 is moved, and the second camera 43 is returned to the standby position. Then, the first camera 39 is also returned to the standby position. Since the dihedral width dimension Sa is the minimum outer diameter of the head 4, when the head diameter dk is measured by the first camera 39, the X-direction dimension of the head 4 is the minimum value. You may measure by calculating the X direction dimension at that time as the dihedral width dimension Sa. When the work 8 has a hexagonal hole as a head hole on the upper surface of the head, the two-sided width dimension of the hexagonal hole and the diagonal dimension that is the diameter of the diagonal position may be calculated. When the head 4 is measured by the second camera 43, the second camera 43 is driven by the camera switching actuator 45 so as not to interfere with the first camera 39 when the second camera 43 moves directly above the workpiece 8. One camera 39 may be configured to move upward. When this configuration is adopted, a mechanism for moving the first camera 39 in the Z-axis direction may be omitted.

  When calculation of measurement data of various dimensions of the workpiece 8 is completed, measurement results are output (S23). Specifically, head diameter, head height, neck round radius, round transition circle diameter, cylindrical diameter, screw diameter, cylindrical length Ls, cylindrical length Lg, neck length Then, the measured value of the bend and the like are printed on a predetermined inspection document and output. At this time, in the inspection document, various measurement values are entered at predetermined entry locations in accordance with a predetermined format set in advance. At this time, the inspection document may be output as a CSV file that is a text file in which the header of each measurement item and the measurement value are separated by a comma. The inspection document may be output with the measurement result assigned to an arbitrary format such as spreadsheet software.

  Thus, according to the screw shape automatic measurement system 10, various dimensions relating to the screw can be automatically measured, and the measurement result can be automatically output as an inspection document of a predetermined or arbitrary format.

  The above-described measurement sequence is an example. In the screw shape automatic measurement system 10, teaching is performed by an operator inputting or selecting a measurement item and a measurement order using the operation unit of the arithmetic control device 100. It can also be set by a process called. For example, a schematic figure of the workpiece 8 integrated so as to stand upright on the upper side of the adapter 80 is displayed on the display of the computer. The user can instruct a measurement location by a simple operation by drawing a rectangular frame using an operation unit such as a keyboard or a mouse. For example, by drawing a frame so as to surround the axial middle part of the screw part, and performing a predetermined simple operation such as pressing a predetermined key button, the diameter of the part surrounded by the frame of the screw, the valley diameter, An instruction to measure at least one of the effective diameters can also be given. It is also possible to give an instruction to measure the screw neck length by drawing a frame portion extending from the screw head to the adapter 80 and performing a predetermined operation. The screw shape automatic measurement system automatically measures the measurement location in accordance with these instructions. In addition, the measurement location, the measurement method, and the measurement procedure can be set in the arithmetic and control unit 100 by the operator setting corresponding parameters in advance. The measurement logic is executed by assigning various auxiliary measurement logics to measurement items using a combination of geometric calculation formulas, which are calculation formulas obtained by geometric relationships. For example, the auxiliary measurement logic includes horizontal distance measurement, vertical distance measurement, angle measurement, curvature radius measurement, calculation, pitch measurement, or substitution of a known value. The black and white image can be binarized and plotted in, for example, an XY coordinate system, and the auxiliary measurement logic can be executed using a geometric calculation formula. In the geometric calculation formula, the binarized image data may be abstracted and calculated as black and white-black and white, black and white-black and white, and so on.

  When performing the above various dimension measurements, the head hole depth can also be measured when a head hole that is a hexagonal hole is formed in the head of the workpiece 8. For example, in the procedure described in FIG. 6A, the head hole depth can be measured before the head diameter measurement in S12. At this time, the head hole depth can be measured using the head hole bit for screw inspection. The head hole bit corresponds to a head engaging adapter. At this time, the state in which the head hole bit 180 is inserted into the head hole 6 of the workpiece 8 is imaged by the first camera 39 from the direction orthogonal to the screw axis, and the head hole depth is based on the acquired projection shape data. T is calculated.

  The state in which the head hole bit 180 is inserted into the head hole 6 of the work 8 is imaged by the first camera 39, and based on the contour data, the upper surface of the head of the work 8 and the wrinkles of the head hole bit 180 are displayed. A distance dimension along the Y direction between the lower surface of the portion 184 can be calculated. Based on the calculated interval dimension and the height dimension of the head hole fitting portion 182 of the head hole bit, it can be calculated from the head hole depth dimension and a geometrical relational expression.

  1 to 3, the first camera Y moving table 25 is movable in the Z direction with respect to the Y table 22, and the first camera Y moving table 37 is operated by the operation of the first camera moving actuator 37. 25 is configured to move in the Z direction. Thereby, the Z direction position of the first camera 39 is adjusted, and using the projection shape of the workpiece 8 imaged by the first camera, the first camera is set to the Z position where the transition from white data to black data is the steepest. The first camera Y movement table 25 can be moved so that is positioned. The position in the Z direction of the first camera Y movement table 25 is fixed with the Z position at that time as the in-focus position.

  Next, with reference to FIGS. 10 to 16, a laser displacement meter 50 (FIGS. 1 and 3) and a configuration for measuring the angle of the seating surface 7 of the head 4 of the workpiece 8 will be described. Specifically, referring to FIG. 1 and FIG. 3, as described above, the screw shape automatic measurement system 10 has the bracket 23 fixed to the lower side of the Y table 22, and the laser displacement meter 50 is attached to the bracket 23. It is fixed. The laser displacement meter 50 is fixed to the upper surface of the tip portion of the bracket 23 so that the irradiation axis of the laser light is directed obliquely upward.

The laser displacement meter 50 is a an interval of a _Z-axis direction displacement and a light receiving element arranged in a _X-axis direction with respect to the measurement object, which measures the displacement of the measurement object, the laser beam emitting element It has the irradiation part 51 (FIG. 3) which has, and the light-receiving part 52 (FIG. 3). The irradiation unit 51 includes an outer peripheral surface of the screw shaft of the work 8, a seating surface of the head of the work 8, and a continuous portion of the outer peripheral surface and the seating surface in a part in the circumferential direction of the work 8 gripped by the gripping unit 62. Irradiate with laser light. The light receiving unit 52 receives the reflected light of the laser light emitted from the irradiation unit 51. The reflected light reflected by the workpiece 8 is incident on the lens of the light receiving unit 52, and the incident light is condensed on an optical sensor chip (not shown) by the lens. An optical sensor chip is a semiconductor device as a line sensor in which a large number of light receiving elements are arranged in a row on a semiconductor substrate. The light receiving position of the reflected light on the optical sensor chip changes according to the distance to the workpiece 8. Thereby, the laser displacement meter 50 measures the displacement between the generatrix of the outer peripheral surface of the screw shaft and the generatrix of the seat surface in a part of the workpiece 8 in the circumferential direction based on the light receiving position on the optical sensor chip. Then, a signal representing the displacement between the bus bar on the outer peripheral surface of the screw shaft and the bus bar on the seat surface is transmitted from the laser displacement meter 50 to the arithmetic and control unit 100 (FIG. 1).

  The arithmetic and control unit 100 includes data indicating a two-dimensional shape based on the displacement measured by the laser displacement meter 50 at least at a predetermined first position among a plurality of circumferential positions around the axial direction of the workpiece 8, and the laser displacement meter 50. The angle of the seat surface 7 with respect to the normal seat surface line CLT (FIG. 10) is calculated and output from the reference line CL (FIG. 10) indicating the irradiation axis direction. The normal bearing surface line CLT is a line orthogonal to the virtual axis direction line CLA corresponding to the axial direction of the screw shaft 5 when the screw shaft 5 of the workpiece 8 is viewed in a cross section including a linear center axis. . Specifically, the arithmetic and control unit 100 includes a two-dimensional shape creation unit 110 and a seating surface angle calculation unit 112 (FIG. 1). The two-dimensional shape creation unit 110 creates data indicating a two-dimensional shape from the displacement measured by the laser displacement meter 50 based on the reception of the reflected light of the laser light.

  FIG. 10 is a diagram illustrating a measurement range of the bus surface of the seat surface 7 and the screw shaft 5 used when calculating the inclination angle of the seat surface 7 of the workpiece 8 of the first example. The two-dimensional shape is a mountain shape including an axial straight line portion that is a straight line portion of the bus bar on the outer peripheral surface of the screw shaft 5 and a bearing surface straight line portion that is a straight line portion of the bus bar of the seat surface 7. At this time, for example, at a predetermined 0-degree position around the axial direction of the screw shaft 5, a range that is out of the continuous portion (intersection) between the generatrix of the outer peripheral surface of the screw shaft 5 and the generatrix of the seat surface 7 in the two-dimensional shape. The shape of the straight line portion (for example, portions indicated by thick lines δ1 and η1 in FIG. 10) may be measured. The two straight portions δ1 and η1 may be extended to the side where they intersect with each other to form a two-dimensional shape that is continuous in a mountain shape. This is because the shape accuracy of the two busbars obtained by receiving the reflected light of the laser beam may be reduced near the intersection of the two busbars, and the measurement results near the intersection are excluded. The straight portion δ1 corresponds to the axial straight portion of the screw shaft 5, and the straight portion η1 corresponds to the seating surface straight portion of the seating surface 7. In FIG. 10, the straight line portion of the measurement range of the generatrix of the seating surface 7 at the position of 180 degrees around the axial direction of the screw shaft 5 is also indicated by a thick line η2. The axial straight portion and the bearing straight portion can be obtained by drawing regression lines from a plurality of measurement points. In addition, a thread portion may be formed in a portion for obtaining the generatrix of the outer peripheral surface of the screw shaft 5. When calculating the bus in the part where the screw part is, extract the multiple peak vertices measured by the screw part and obtain the regression line from the extracted multiple vertices, or multiple valleys measured by the screw part A base point is extracted, and a regression line is obtained from the extracted base points. At this time, a regression line obtained from only a plurality of peak portions or only a plurality of valley bottom points can be used as the axial straight line portion.

  S1 and S2 may be set as parameters for indicating the measurement range of the axial linear portion δ1 of the screw shaft. S <b> 1 and S <b> 2 indicate a measurement start position and a measurement end position, respectively, descending from below the neck along the generatrix of the screw shaft 5. The generatrix of the screw shaft 5 is obtained from a regression line of sampling data in the measurement range. Further, Z1 and Z2 may be set as parameters for indicating the measurement range of the seating surface straight line portion η1 of the seating surface 7. Z1 and Z2 respectively move along the generatrix of the seating surface 7 from the outer peripheral end to the inner peripheral side with Z1 and Z2, and indicate a measurement start position and a measurement end position. The generatrix of the seating surface 7 is obtained from a regression line of sampling data in the measurement range.

Note that, at the 0 degree position and the 180 degree position, an angle formed by a later-described reference orthogonal line CLR and a seating surface 7 orthogonal to the reference line CL of the laser displacement meter 50 is a seating angle θ _0Z and a seating angle θ _180Z ( You may obtain | require as FIG. 10, FIG. 14), respectively.

  In the laser displacement meter 50, a head unit having an irradiation unit 51 and a light receiving unit 52 and an arithmetic control device that calculates displacement based on data sent from the head unit are physically separated and connected to each other by a cable. It is good also as composition to be.

  Data indicating the two-dimensional shape created by the two-dimensional shape creation unit 110 is acquired by the seating surface angle calculation unit 112. Hereinafter, data indicating a two-dimensional shape is referred to as two-dimensional shape data. Then, as will be described later, the seating surface angle calculation unit 112 calculates the first seating surface angle α and the second seating surface angle β from the two-dimensional shape data and the reference line CL indicating the irradiation axis direction of the laser displacement meter 50. Calculate each. The first seating surface angle α is an angle of the seating surface 7 with respect to the normal seating surface line CLT orthogonal to the virtual axis direction line CLA corresponding to the axial direction of the screw shaft 5 at the 0 degree position. A method of calculating the virtual axis direction line CLA will be described later. The second seating surface angle β is an angle of the seating surface 7 with respect to the normal seating surface line CLT orthogonal to the virtual axis direction line CLA corresponding to the axial direction of the screw shaft 5 at the 180 degree position. At this time, the seating surface angles α and β are expressed by dividing the inclination direction of the seating surface 7 with respect to the normal seating surface line CLT by positive and negative. For example, in FIG. 10, the inclination angle when the seat surface 7 is inclined to the front end side of the head 4 (upper side in FIG. 10) from the normal bearing surface line CLT is positive, and the front end side of the screw shaft 5 (lower side in FIG. 10). The inclination angle when the seat surface 7 is inclined to the side) is negative. Then, the seat surface angle calculation unit 112, when dividing the inclination direction of the seat surface 7 with respect to the normal seat surface line CLT by positive and negative, is positive or negative of the sum (α + β) of the first seat surface angle α and the second seat surface angle β. The inclination direction of the seating surface is determined from the sign of. At this time, a plurality of two-dimensional shape data corresponding to a plurality of positions in the circumferential direction of the workpiece 8 are created in the two-dimensional shape creation unit 110, so that the seating surface angle calculation unit 112 also determines the angle of the seating surface 7 as the workpiece. It may be calculated and output corresponding to a plurality of positions in the circumferential direction.

  FIG. 11A shows a state in which, when the seating surface angle of the head 4 of the workpiece 8 is measured, the circumferential position for measuring the seating surface angle is set after the workpiece 8 is fixed by the fastening chuck 70. FIG. (B) is a figure which shows the detection position and detection width of a seat surface inclination in the AA cross section of the workpiece | work 8 shown to (a). (C) is a figure which shows the state which determines the diagonal position of the head 4 from the projection image of the workpiece | work 8 when the workpiece | work 8 is a hexagon bolt. (D) is a figure which shows the state which determines the diagonal position of the head 4 from the projection image of the workpiece | work 8, when the workpiece | work 8 is a hexagon socket head bolt. FIG. 12 is a diagram illustrating a state in which the displacement of the seating surface 7 and the outer peripheral surface of the screw shaft 5 is measured in a state where the workpiece 8 is gripped by the gripping portion 62 (FIG. 11) in the screw shape automatic measurement system 10. FIG. 12A shows an irradiation position by the laser displacement meter 50 in the side view of the workpiece 8, and FIG. 12B is a top view of the workpiece 8.

In Figure 12, it illustrates the irradiation direction of the laser displacement meter 50 in a _Z direction, orthogonal to a _Z direction indicates a direction parallel with a _X-direction to the YZ plane. Light-receiving element of the laser displacement meter 50 is on the light-sensing chip are arranged side by side a plurality in a row in a _X direction.

  Returning to FIG. 11, as a condition for creating the two-dimensional shape data of the workpiece 8, a method of positioning a plurality of circumferential positions around the axial direction of the workpiece 8 will be described. The two-dimensional shape data is created based on the irradiation and reflection of laser light at a predetermined circumferential position of the work 8 by rotating the θ motor while the work 8 is held by the holding portion. For this reason, it is necessary to position the workpiece 8 at a predetermined circumferential position for creating the two-dimensional shape data. First, a case where the circumferential position of the workpiece 8 is set manually will be described. At this time, as shown in FIG. 11B, two-dimensional shape data is created at six diagonal positions indicated by T1, T2,... To do.

  Here, the diagonal position is a position that coincides with the six apexes of the outer peripheral surface of the hexagonal head 4 of the workpiece 8 in the circumferential direction. In this case, the two diagonal positions T1 and T4 are located on the first diagonal line La1 of the head 4, and the two diagonal positions T2 and T5 are located on the second diagonal line La2 of the head 4. Further, the two diagonal positions T3 and T6 are located on the third diagonal La3 of the head 4. And when setting the circumferential position which measures the angle of the seating surface 7 of the workpiece | work 8 manually, as shown, for example to Fig.11 (a), the upper surface of one nail | claw part 76a of the clamping chuck | zipper 70 is previously carried out. Marking is performed at a predetermined position in the circumferential direction with a broken line-shaped mark 54 in the radial direction of the workpiece 8 or the like. The predetermined position in the circumferential direction corresponds to the origin position of an encoder (not shown) provided for detecting the rotation angle of the θ motor. Then, the operator causes the gripping portion 62 to grip one end portion of the workpiece 8 on the screw side so that the marking position of the tightening chuck 70 and one diagonal position T1 of the workpiece 8 coincide with each other in the circumferential direction. Then, six positions set by rotating 60 degrees from the origin position to 360 degrees in the circumferential direction of the workpiece 8 are set as diagonal positions.

  In FIG. 11B, the measurement range in which the shape is measured for creating two-dimensional shape data on the seating surface 7 is indicated by the thick solid line U at the diagonal position T3. As shown in FIG. 11B, the vicinity of the radially inner end and the radially outer end of the seating surface 7 is excluded in the measurement range. Thereby, the detection accuracy of the bearing surface angle calculated based on the data of the two-dimensional shape can be increased. Since the detection width of the seating surface 7 varies depending on the type of the workpiece 8, before calculating the seating surface angle, the operator inputs a numerical value or the like indicating the detection width to the arithmetic control device 100 using the operation unit in advance. May be configured to instruct. The arithmetic and control unit 100 sets a detection width used for calculating the seating surface angle in accordance with the instruction.

  Next, the case where the circumferential position for measuring the angle of the seating surface 7 of the workpiece 8 is automatically detected and positioned will be described. At this time, a signal representing data indicating the projection shape captured by the first camera 39 is input to the arithmetic control device 100. The arithmetic and control unit 100 automatically irradiates the workpiece 8 with laser light at an appropriate timing corresponding to the diagonal position of the workpiece 8 from the data indicating the projected shape, and the seating surface 7 based on reception of the laser beam. Calculate and output the slope of.

  A method for obtaining the diagonal position from the projected shape of the workpiece 8 will be described with reference to FIG. In FIG. 11C, a projected image obtained by capturing the vicinity of the head 4 of the work 8 with the first camera 39 (FIG. 1) is indicated by an oblique lattice portion. Actually, an image in which the oblique lattice portion is black is captured. The image projection unit 34 (FIG. 1) images the head 4 of the work 8. Then, the seating surface angle calculation unit 112 calculates and outputs the angle of the seating surface 7 according to a change in the dimension around the axis of the head 4 measured using the first camera 39. Specifically, as the workpiece 8 is rotated by the θ motor, the width in the X direction in the projected shape of the hexagonal head 4 is enlarged or reduced. For example, when the width of the head 4 in the X direction is the smallest E1, the center in the X direction is a diagonal position, for example, the position of T3 or T6. At this time, the two-dimensional shape creating unit 110 irradiates the center of the workpiece 8 with the laser beam and creates two-dimensional shape data based on the reception of the laser beam. Based on the two-dimensional shape data, the seat surface angle calculation unit 112 includes a first seat surface angle α (FIGS. 13, 15, and 16) that is a seat surface angle at two positions that are different by 180 degrees, and a second seat. The surface angle β (FIGS. 14, 15, and 16) is calculated and output.

  On the other hand, when the projected shape of the head 4 becomes a two-dot chain line V as shown in FIG. 11C, the width of the head 4 in the X direction is E2, which is the maximum. At this time, the center in the X direction serves as a reference for the width of the two surfaces, and a flat portion of the outer peripheral surface of the head 4 called a facing position is located. At this time, the arithmetic and control unit 100 may irradiate the center of the workpiece 8 with the laser beam and calculate the inclination of the seating surface 7 based thereon.

  In some cases, the work 8 is a hexagon socket head cap screw. In this case, the outer peripheral surface of the head 4 is a cylindrical surface. The position cannot be determined. At this time, a head hole bit 180 as shown in FIG. 11D is fitted into and engaged with a non-circular head hole 6 such as a hexagon, and the first camera 39 engages with the head hole 6. The dimension of the head hole bit 180 around the axis is measured by image projection. Specifically, the arithmetic and control unit 100 sets the diagonal position or the facing position of the head hole 6 from the projected shape of the head hole fitting portion 182 having a hexagonal cross section in the head hole bit 180. Then, according to the set diagonal position or facing position, the two-dimensional shape creating unit 110 irradiates the center of the workpiece 8 with the laser beam and creates two-dimensional shape data based on the laser beam. At this time, the two-dimensional shape creation unit 110 determines the axis of the workpiece 8 from which the width in the X direction of the head hole bit 180 engaged with the head 4 is maximized or minimized from the projected shape imaged by the first camera 39. Two-dimensional shape data at a plurality of circumferential positions around the direction is created. The seating surface angle calculation unit 112 calculates and outputs the angle of the seating surface 7 according to a change in the dimension of the head hole bit 180 measured using the first camera 39. When the head hole is other than a hexagonal hole, for example, the circumferential position for measuring the angle of the seating surface 7 of the workpiece 8 can be set manually. In the screw shape automatic measurement system 10, it is set in advance whether the circumferential position for measuring the seating surface angle in the workpiece is set manually or automatically.

A measurement algorithm for the seating surface 7 of the workpiece 8 will be described with reference to FIGS. FIG. 13 is a diagram illustrating a state in which the tilt angle of the seating surface of the workpiece is measured when the angular position around the axial direction of the workpiece 8 of the first example is 0 degrees. (A) is a figure which shows the _{workpiece |} work 8, reference angle (theta) c, 1st basic angle (theta) _C0 , seating angle (theta) _0Z , 1st seating surface angle (alpha), and seating surface average inclination amount (gamma), (b) (c). It is a figure which shows the relationship of the one part angle taken out from (a). FIG. 14 is a diagram illustrating a state in which the tilt angle of the seating surface of the workpiece is measured when the angular position around the axial direction of the workpiece of the first example is 180 degrees. (A) is a view showing a workpiece and a reference angle θc, a second basic angle θ _C180 , a seating angle _θ180Z , a second seating surface angle β, and a seating surface average inclination amount γ, and (b) and (c) are It is a figure which shows the relationship of the one part angle taken out from (a).

  In the following, the method for calculating the first seating surface angle α, the second seating surface angle β, and the pass / fail judgment value γa at the 0 degree position and the 180 degree position around the axial direction of the screw shaft 5 in the workpiece 8 will be mainly described. . The calculation method for the remaining angular positions is the same except that the angular position of the workpiece 8 around the axial direction is different. The reason for calculating the seat surface inclination at two positions having different 180-degree angles such as the 0-degree position and the 180-degree position is to accurately obtain the side on which the seat surface 7 is inclined.

  First, as shown in FIG. 12, the work 8 is screwed and attached to the ring gauge 82 of the adapter 80. In this state, as the two diagonal positions of the workpiece 8, the angle of the seat surface 7 at the 0 degree position and the 180 degree position around the axial direction is measured.

Specifically, the two-dimensional shape creation unit 110 creates two-dimensional shape data in which two straight lines intersect with each other at a 0 degree position and a 180 degree position around the axis of the workpiece 8. For example, in order to obtain the reference angle θ _C at the 0-degree position and the 180-degree position, the two-dimensional shape creation unit 110 first forms a two-dimensional shape formed from the bus P1 of the seating surface 7 and the busbar Q1 of the outer peripheral surface of the screw shaft 5. Create a shape. Specifically, as shown in FIG. 13, at the 0 degree position, a two-dimensional shape is created using two buses P1 and Q1 for the a _X direction position and the a _Z direction displacement of the input value of the light receiving unit. The At this time, as described above, it is sufficient that only two partial straight lines are measured for the two buses, and the remaining part may be obtained by extending linearly. Moreover, a male thread part may be applied to the bus bar of the screw shaft 5, and in this case, a linear bus bar measured near the neck can be extended and used. In addition, when a thread part is formed in the substantially whole screw shaft 5, you may create the linear bus line which tied the top part of the peak part of a male thread part as a bus line of the screw shaft 5. FIG. Further, as shown in FIG. 14, at the 180 degree position, the two-dimensional shape is created in the same manner as in the case where the two-dimensional shape is at the 0 degree position from the generatrix P2 of the seating surface 7 and the generatrix Q2 of the outer peripheral surface of the screw shaft 5. At this time, the buses P1 and Q1 are measured at an angular position of 0 degrees, and then the workpieces P2 and Q2 are measured at an angular position of 180 degrees by rotating the work 8 by 180 degrees with a θ motor.

Then, in order to obtain the virtual axis direction line CLA corresponding to the screw shaft center line of the workpiece 8, measurement data of the bus bar of the screw shaft 5 at the 0 degree position and the 180 degree position is used. At this time, a reference orthogonal line CLR orthogonal to the reference line CL (FIGS. 10 and 13) indicating the irradiation axis direction a _Z of the laser displacement meter 50 is obtained. Further, a first basic angle θ _C0 and a second basic angle θ _C180 that are angles formed between the reference orthogonal line CLR and the screw shaft buses P1 and P2 (FIGS. 13 and 14) at the 0-degree position and the 180-degree position are obtained. . Then, as in the following equation (3), the average value of the absolute values of the first basic angle θ _C0 and the second basic angle θ _C180 is obtained as the reference angle θ _C.
θ _C = (| θ _C0 | + | θ _C180 |) / 2 (3)

Then, the reference orthogonal line CLR is translated so as to pass through the intersection point O1 of the generating line of the seating surface 7 at the 0 degree position and the 180 degree position to obtain the corrected reference orthogonal line CLR2. A straight line inclined by the reference angle θ _C from the corrected reference orthogonal line CLR2 toward the screw shaft center side becomes the virtual axis direction line CLA. Since the normal bearing surface line CLT is orthogonal to the virtual axis direction line CLA, it is obtained by tilting it by 90 degrees with respect to the virtual axis direction line CLA. Then, the first seating surface angle α and the second seating surface angle β, which are the angles of the seating surface 7 with respect to the normal seating surface line CLT, are calculated. For example, at the 0 degree position shown in FIG. 13, the bus line Q1 of the seat surface 7 is inclined toward the tip side ((−) side) of the screw shaft 5, so that the angle formed by the bus line Q1 and the normal seat surface line CLT is A certain first bearing surface angle α is a negative value. In addition, even at the 180-degree position shown in FIG. 14, since the generatrix Q2 of the seating surface is inclined toward the tip side ((−) side) of the screw shaft, the angle formed by the generatrix Q1 and the normal seating surface line CLT is the first angle. The two-seat surface angle β is also a negative value.

  Then, the seating surface angle calculation unit 112 calculates the sign of the sum of the first seating surface angle α and the second seating surface angle β when the inclination direction of the seating surface 7 with respect to the normal seating surface line CLT is divided into positive and negative. The inclination direction of the seating surface 7 is determined. Specifically, when the sum of the first seating surface angle α and the second seating surface angle β is positive (α + β> 0), the seating surface tilt direction is determined to be positive. At this time, the seat surface 7 is inclined so that the outer peripheral end is inclined toward the other end side of the workpiece 8 (the upper end side in FIG. 13A) and toward the distal end side of the head 4. . In this case, when the head 4 is set to the top, the inclination of the seat surface 7 opens upward, and is V-shaped. When the sum of the first seating surface angle α and the second seating surface angle β is negative (α + β <0), the seating surface tilt direction is determined to be negative. At this time, the seat surface 7 is inclined so that the outer peripheral end is inclined toward the one end side (the lower side of FIG. 13A) of the workpiece 8 and toward the tip end side of the screw shaft 5. In this case, since the inclination of the seat surface 7 opens downward when the head 4 is set to the top, it is an inverted V type. Further, when the sum of the first seating surface angle α and the second seating surface angle β is 0 (α + β = 0), the seating surface tilt direction is 0, and the seating surface 7 has a linear tilt.

Further, the seating surface angle calculation unit 112 calculates an average inclination amount γ of the seating surface 7 from the absolute value of the first seating surface angle α and the absolute value of the second seating surface angle β. Specifically, the average inclination amount γ is obtained by the average value of the absolute value of the first seating surface angle α and the absolute value of the second seating surface angle β as in the following equation (4).
γ = (│α│ + │β│) / 2 (4)

Furthermore, the seating surface angle calculation unit 112 performs a pass / fail determination of the seating surface tilt from the calculated average tilt amount γ and the determination result of the tilting determination direction of the seating surface 7. For example, when the seating surface 7 is tilted in an inverted V shape and when the seating surface 7 is a linear type, the average tilt amount γ matches the pass / fail judgment value γa as in the following equation (5).
γa = γ (5)

Further, when the seating surface 7 is inclined in a V shape, a value obtained by multiplying the average inclination amount γ by (−1) as the following equation (6) becomes the pass / fail judgment value γa.
γa = (− 1) × γ (6)

  And the seat surface angle calculation part 112 performs a pass determination, when the pass / fail judgment value (gamma) a is 0 or more, ie, when the seat surface 7 inclines to a reverse V type or is a linear type. In addition, the seating surface angle calculation unit 112 performs a failure determination when the acceptance / rejection determination value γa is less than 0, that is, when the seating surface is inclined in a V shape. Thereby, it can be determined whether or not the workpiece 8 is usable. At this time, when the seat surface 7 is an inverted V type, when the screw is screwed into the screw hole, the seat surface 7 is pressed against the side surface of the periphery of the opening of the screw hole. Thereby, the seat surface 7 is deformed so as to approach a flat surface, and the contact area with the side surface is increased. As a result, the screw is strongly coupled to the screw hole while retaining the same as when the disc spring is disposed between the screw head 4 and the screw hole. On the other hand, when the seat surface 7 is V-shaped, even if the screw is screwed into the screw hole, the contact area between the seat surface 7 and the side surface around the screw hole opening remains small, and the coupling strength of the screw to the screw hole is small. For this reason, according to the method of performing the above pass determination, it is possible to appropriately determine whether or not the work 8 is usable.

  Then, the seat surface angle calculation unit 112 outputs the calculation results of the calculated first seat surface angle α, second seat surface angle β, seat surface tilt direction, average tilt amount γ, and pass / fail judgment value γa to the output device 104 ( 1). At this time, information indicating the calculation result, for example, an inspection document including a numerical value is output by the output device 104. The output device 104 may output only one or a part of the first seat surface angle α, the second seat surface angle β, the seat surface tilt direction, the average tilt amount γ, and the pass / fail judgment value γa. Good. At this time, the seat surface angle calculation unit 112 may calculate only the first seat surface angle α. The output device 104 may output or transmit a display, a recording device, or a file in which the contents of the inspection document are recorded to the outside.

  Next, a method for calculating the pass / fail determination value γa will be described in more detail with reference to FIGS. 13 and 14. For example, let us consider a case where the first seating surface angle α is calculated as −15 degrees at the 0 degree position shown in FIG. 13 and the second seating surface angle β is calculated as −5 degrees at the 180 degree position shown in FIG. In this case, α + β is calculated to determine the tilt direction. Since α + β = −20 (degrees), it is determined that the seating surface is inclined in an inverted V shape. Further, the average inclination amount γ is calculated from the equation (4) as γ = 10 (degrees). At this time, since the seating surface is an inverted V type, the pass / fail judgment value γa = 10 (degrees) is calculated from the equation (5), and since γa is 0 or more, it is determined to be acceptable.

  FIG. 15A shows a state in which the inclination angle of the seating surface 7 of the workpiece is measured when the angular position around the axial direction is 0 degree in the workpiece 8 of the second example. It is a figure corresponding to. FIG. 15B shows a state in which the tilt angle of the seating surface of the workpiece is measured when the angular position about the axial direction is 180 degrees in the workpiece 8 of the second example. It is a corresponding figure.

  In the case of the workpiece 8 of the second example shown in FIG. 15, the seating surface is inclined in a V shape. At this time, the first seating surface angle α is calculated as 15 ° at the 0 ° position shown in FIG. 15A, and the second seating surface angle β is calculated as 5 ° at the 180 ° position shown in FIG. 15B. The In this case, α + β is calculated in order to determine the tilt direction, and α + β = 20 (degrees), so it is determined that the seat surface 7 is tilted in a V shape. Further, the average inclination amount γ is calculated from the equation (4) as γ = 10 (degrees). At this time, since the seating surface is V-shaped, the pass / fail judgment value γa = −10 (degrees) is calculated from the equation (6), and since γa is less than 0, it is determined to be unacceptable.

  FIG. 16A shows a state in which the tilt angle of the seating surface 7 of the workpiece is measured when the angular position around the axial direction is 0 degrees in the workpiece 8 of the third example. It is a figure corresponding to. FIG. 16B shows a state in which the inclination angle of the seating surface 7 of the workpiece is measured when the angular position around the axial direction is 180 degrees in the workpiece 8 of the third example. It is a figure corresponding to.

  In the case of the work of the third example shown in FIG. 16, the seating surface 7 is linear, but is inclined with respect to the normal seating surface line CLT. At this time, the first seating surface angle α is calculated as 15 ° at the 0 ° position shown in FIG. 16A, and the second seating surface angle β is calculated as −15 ° at the 180 ° position shown in FIG. 16B. Is done. In this case, α + β is calculated in order to determine the tilt direction, and α + β = 0 (degrees), so the seating surface 7 is determined to be linear. On the other hand, the average inclination amount γ is calculated from the equation (4) as γ = 15 (degrees). At this time, since the seat surface 7 is a linear type, the pass / fail judgment value γa = 15 (degrees) is calculated from the equation (5), and since γa is 0 or more, it is determined to be acceptable. In the case of the straight type shown in FIG. 16, when the screw is screwed into the screw hole, one side of the seat surface 7 (left side of FIG. 16 (a), right side of FIG. 16 (b)) is the periphery of the opening of the screw hole. Since it is pressed against the side surface, the seating surface 7 is deformed so as to approach a flat surface, and the contact area with the side surface increases. Also in this case, the screw is strongly coupled to the screw hole as in the inverted V type.

In addition, as shown in the calculation result of FIG. 16, when the pass / fail judgment value γa is positive and the calculation result indicates that the value is linear, the seating surface 7 is linear and the normal seating surface. It can also be determined that the seat surface 7 is inclined with respect to the line CLT. This makes it possible to determine the inclination state of the seating surface 7 with higher accuracy, unlike the determination method that determines the seating surface inclination using only the difference between the first seating surface angle α and the second seating surface angle β.

In the above description, the case in which dimensions other than the seat surface inclination of the workpiece 8 are measured using a camera has been described. However, the present invention is not limited to this, and various types can be used without departing from the spirit of the present invention. Applicable to structure.

  2 Male thread part, 3 neck lower part, 4 head part, 5 screw shaft, 6 head hole, 7 seating surface, 8 workpiece, 9 cylindrical part, 10 thread shape automatic measuring system, 12 thread shape automatic measuring device, 16 base 18 pillar member, 20 lift actuator, 20a actuator case, 20b Y motor, 22 Y table, 22a table body, 22b light source table, 23 bracket, 23a plate part, 24 position sensor, 25 first camera Y moving table, 32 optical Measurement device, 34 image projection unit, 35 first camera Z movement table, 36 light source, 37 first camera movement actuator, 38 first camera group, 39a, 39b, 39c first camera, 40 head measurement unit, 42 2 camera group, 43a, 43b, 43c 2nd camera, 44 2nd camera movement table, 45 turtles Switching actuator, 45a Electric motor, 46 Second camera movement actuator, 46a Electric motor, 50 Laser displacement meter, 51 Irradiation unit, 52 Light receiving unit, 54 mark, 60 Grip rotating unit, 62 Gripping unit, 70 Tightening chuck, 72 Support Base, 74a, 74b, 74c slide base, 76a, 76b, 76c claw part, 78a, 78b piston, 80 adapter, 82 ring gauge, 86 holder, 88 clamping ring part, 90 stopper collar part, 100 arithmetic control unit, 102 empty Pressure control device, 104 output device, 110 two-dimensional shape creation unit, 112 seating surface angle calculation unit, 170, 171 contour data, 172, 174, 176 regression line, 173, 177 perpendicular, 180 head hole bit, 182 head Hole fitting part, 184 collar part, 186 cylindrical part for gripping, 90 illumination unit, 192 lighting moving mechanism.

Claims (8)

With a screw as a measurement target workpiece, a gripping portion that grips one axial end of the workpiece on the screw side,
A gripping rotation unit that rotates the gripping unit 360 degrees around the axial direction;
Irradiation that irradiates laser light to the outer peripheral surface of the screw shaft of the workpiece and the seating surface of the head of the workpiece in a part of the workpiece in the circumferential direction, where one end in the axial direction of the male screw is held by the holding portion A displacement meter for measuring the displacement between the generatrix of the outer peripheral surface of the screw shaft and the generatrix of the seat surface, and a light receiving portion that receives the reflected light of the laser beam,
From data indicating a two-dimensional shape based on a displacement measured by the displacement meter at least at a first position among a plurality of circumferential positions around the axial direction of the workpiece, and a reference line indicating an irradiation axis direction of the displacement meter A screw shape automatic measurement system comprising: an arithmetic control device that calculates a first seating surface angle that is an angle of the seating surface with respect to a normal seating surface line orthogonal to a virtual axis direction line corresponding to the axial direction of the screw shaft. . In the screw shape automatic measurement system according to claim 1,
The calculation control device is a screw shape automatic measurement system that outputs a calculated value of the first seating surface angle at the first position. In the screw shape automatic measurement system according to claim 1,
The arithmetic and control unit, based on data indicating a two-dimensional shape based on a displacement measured by the displacement meter at a second position different from the first position by 180 degrees around the workpiece in the axial direction, and the reference line, When the second seating surface angle that is the angle of the seating surface with respect to the normal seating surface line is calculated, and the inclination direction of the seating surface with respect to the regular seating surface line is divided by positive and negative, the first seating surface angle and the A screw shape automatic measurement system that determines the inclination direction of the seating surface from the sign of the sum of the second seating surface angles. In the screw shape automatic measurement system according to claim 3,
An automatic screw shape measurement system that calculates an average inclination amount of the seating surface from an absolute value of the first seating surface angle and an absolute value of the second seating surface angle. In the screw shape automatic measurement system according to claim 4,
In the first position and the second position, the arithmetic and control unit uses a case where the seat surface is inclined so that an outer peripheral end of the seat surface is directed to one end side of the workpiece, In the case where the seat surface is inclined so that the outer peripheral end is directed to the other end side of the workpiece, the seat surface is an inverted V type in the case where the seat surface is inclined when the tilt direction is zero. A screw shape automatic measurement system that performs a pass determination when the bearing surface is inclined to a straight line type or performs a failure determination when the seat surface is inclined to a V type. In the screw shape automatic measurement system according to any one of claims 1 to 5,
The axial direction is the Y direction, and the plane perpendicular to the Y direction is the XZ plane.
A base having an upper surface parallel to the XZ plane;
The grip portion is provided on the upper side of the base so as to be rotatable around the axial direction,
An image projection unit that images the head or a head engaging adapter engaged with a head hole of the head;
The arithmetic and control unit is
The screw shape automatic measurement system which calculates the angle of the said seat surface with respect to the said normal seat surface line according to the change of the dimension around the axis of the said head or the said head engagement adapter imaged by the said image projection part. In the screw shape automatic measurement system according to claim 6,
The image projection unit
A light source arranged on one side in the Z direction with respect to the center line in the Y direction of the workpiece, and outputs a parallel light beam;
An optical axis that is disposed on the other side in the Z direction with respect to the center line in the Y direction of the workpiece and has the same light receiving optical axis as the light source with respect to a projection shape that receives the parallel rays from the light source and becomes a shadow of the workpiece A projection imaging camera of a telecentric optical system that forms an image on an imaging plane parallel to the XY plane and images only the component parallel to the XY plane;
A screw shape automatic measuring system. In the screw shape automatic measurement system according to claim 7,
The arithmetic and control unit is provided at a plurality of circumferential positions around the axial direction of the workpiece at which the width in the X direction of the head or the head engaging adapter is maximum or minimum from the projection shape captured by the projection imaging camera. A screw shape automatic measurement system that creates the data indicating the two-dimensional shape and calculates an angle of the seating surface with respect to the regular seating surface line from the data.

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