TW201606261A - Screw dimension automatic measurement system - Google Patents

Abstract

The present application is related to a screw dimension automatic measuring system. The screw dimension automatic measuring system regards screw as a measurement object workpiece, comprising: a gripping portion, gripping an axial end of male screw of a workpiece; a gripping rotating portion, rotating and driving the gripping portion about the axial direction by 360 degree; an optical measurement device, optically measuring the size of the workpiece without contact in which the male screw of the axial end of the workpiece is gripped by the gripping portion; an axial movement portion, moving the optical measuring device relatively to the gripping portion along the axial direction; a calculation controlling unit, calculating and then outputting the axial size of the workpiece and the size around the axis of the workpiece. The calculation controlling device comprises: a screw diameter calculating unit, calculating the size relative to the crest of the screw and the size relative to the root of the screw of the workpiece; and a total length calculating unit, calculating the total length along the axial direction of the workpiece.

Description

Screw size automatic measuring system

BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to an automatic screw size measuring system, and more particularly to an automatic screw size measuring system for automatically measuring various sizes of screws.

In the screw manufacturer, various dimensions of the screw are measured in order to manufacture the manufactured screw to a product that meets the preset specifications. Various sizes of screws are available in specifications. In order to measure these specifications, various measuring devices such as micrometers, calipers, and thread gauges are used separately, and most of the measurements are performed by the inspector's manual work. Screw size check. There are more than 10 dimensions that should be managed in one screw. In the measurement of these dimensions, different measuring devices are used, and the inspection results are recorded in the checklist by the handwriting of the staff.

This screw size measurement requires a lot of effort and time, and therefore, some automatic measurement methods have been proposed. For example, in Japanese Laid-Open Patent Publication No. 2012-112929, the screw inspection device discloses a device in which a head portion of a screw unit fixing screw is used to illuminate a thread portion from a illuminator, and a relative light is used. Provided in the illuminator in the threaded portion The light receiver on the opposite side acquires the light and dark image of the threaded portion, and uses the computer to calculate the image obtained by the threaded portion to display measurement information such as the length, the width of the screw, and the top of the screw. The above description shows that the illuminator and the light receiver can be moved along the axial direction of the threaded portion, and the head of the screw is rotated to change the direction of the threaded portion, whereby the outer circumference of the screw can be inspected 360 degrees.

In the screw shape measuring device, a device having a light source that emits light in parallel with a spiral of a screw, and an imaging device having a linear sensor, the straight line, is disclosed in Japanese Laid-Open Patent Publication No. 2010-210292 The sensor uses a telecentric lens having a light receiving optical axis identical to the light source and imaging only a component parallel to the optical axis, and obtains a one-dimensional image sensor in a direction orthogonal to the screw axis. Here, a plurality of one-dimensional images are obtained by scanning a screw slot, and these images are combined to measure the shape of the screw.

In the prior art, automatic measurement of the dimensional relationship of the threaded portion has been proposed, but the measurement of various dimensions of the screw other than the threaded portion has not been described.

For example, in the case of a cap screw, the shape and size of the head, the radius of curvature of the head lower portion between the head portion and the screw portion, the depth of the head hole provided in the head portion, and the like are not described. In addition, in the measurement of the size of the winding axis of the screw, it is necessary to rotate the screw about the axis, and the rotation and measurement are not easily performed continuously. In Japanese Patent Laid-Open Publication No. 2012-112929, in order to inspect the outer circumference of the screw over 360 degrees, the chuck unit is temporarily released from fixing the head portion, and the head is rotated, and the head unit is again fixed by the chuck unit. Therefore, rotation and measurement cannot be performed continuously.

An object of the present invention is to provide an automatic screw size measuring system capable of automatically measuring various sizes of screws by mounting only a screw as a workpiece to be measured.

The automatic screw size measuring system of the present invention is a workpiece for measuring a screw, comprising: a grip portion that grips one end of an axial direction of a male thread of the workpiece; and a grip rotating portion that rotates the driving grip portion 360 degrees around the axial direction The optical measuring device optically and non-contactly measures the size of the workpiece at one end of the axial direction of the male thread held by the grip portion; the axial moving portion moves the optical measuring device relative to the grip portion in the axial direction; And the calculation control device calculates and outputs the dimension of the workpiece in the axial direction and the axis; wherein the calculation control device includes: a screw diameter calculation unit that calculates a dimension related to the thread top of the workpiece and a dimension related to the thread bottom; And the full length calculation unit calculates the total length along the axial direction of the workpiece.

In the automatic screw size measuring system of the present invention, preferably, the grip portion includes: an adapter having a disc-shaped outer shape and a female thread having a predetermined engagement length at a center of the end surface, the female thread being attached to When screwing into the front end of the male thread of the workpiece, it can be fixed so that the axial direction of the workpiece does not sway; the chuck is fastened, and the outer peripheral side of the adapter is clamped at least at three points.

In the automatic screw size measuring system of the present invention, preferably, the adapter has a ring gauge engraved with a reference female thread corresponding to a thread size of a male thread of the workpiece and having a predetermined meshing accuracy; a disk-shaped The bracket has an end surface protruding from a male thread engaged with the reference female thread of the ring gauge; wherein the circular shape of the bracket is a common shape regardless of the screw size of the workpiece.

In the automatic screw size measuring system of the present invention, it is preferable that the axial direction is the Y direction, the surface perpendicular to the Y direction is the XZ plane, and the base having the upper surface parallel to the XZ plane is provided, and the holding is performed. The portion is rotatably disposed on the upper surface of the base plate in the axial direction, and the axial movement portion includes a moving table on which the optical measuring device is mounted, that is, a moving work that can be moved to the Y position in the Y direction with respect to the base plate. The optical measuring device includes an image projection unit that measures the axial direction of the workpiece and the size of the axis.

Further, in the automatic screw size measuring system of the present invention, preferably, the image projecting unit includes a light source that is disposed on one side in the Z direction with respect to a center line of the workpiece in the Z direction and outputs parallel rays; projection of the telecentric optical system The imaging camera is disposed on the other side in the Z direction with respect to the center line of the Y direction of the workpiece, receives parallel rays from the light source, and has the same light receiving optical axis as the light source and only the optical axis with respect to the projection shape of the workpiece image. Parallel components are imaged on an imaging surface parallel to the XY plane for imaging.

Further, in the automatic screw size measuring system of the present invention, preferably, the arithmetic control device includes a contour data calculating unit that converts projection shape data of the workpiece imaged by the projection imaging camera into an arbitrary position resolution. The 2-dimensional data of the bit map, and the data of the 2-dimensional data of the bit map is binarized into black and white using a predetermined threshold.

Further, in the automatic screw size measuring system of the present invention, preferably, the contour data calculating unit performs the cross-sectional view of the black and white binarized boundary data based on the preset noise determination criterion. Smoothing where the abnormal data is removed as noise The contour data indicating the distribution of the screw contour is obtained, and the contour data calculation unit calculates and outputs the axial and circumferential axes of the workpiece according to the contour data of every predetermined angular interval when the workpiece is rotated 360 degrees around the Y axis. size.

Further, in the automatic screw size measuring system of the present invention, it is preferable that the focus adjustment moving unit includes a projection imaging camera that moves in the Z direction, and the calculation control device includes a focus position calculation unit as a conversion position. The pre-processing of the meta-image, the focus position calculation unit is a method of converting the projection shape data of the screw captured by the projection imaging camera from the white data to the edge region of the black data, and obtaining the maximum value at the black-and-white boundary of the projection shape data. By using the preset evaluation function, the focus of the evaluation function of each Z position is obtained by moving the projection imaging camera in the Z direction by the focus moving unit, and the Z position at which the value of the evaluation function becomes the maximum value is combined. The focal position is used to fix the Z-direction position of the projection camera.

Further, in the automatic screw size measuring system of the present invention, preferably, the arithmetic control device determines a group of measurement data of the size of the workpiece around the Y-axis for the contour data of the workpiece at predetermined angular intervals, and The measurement data of the aforementioned size that is out of the predetermined lower limit threshold value to the preset upper limit threshold value is excluded, and the value of the size around the Y axis is calculated based on the remaining group of the measurement data of the aforementioned size and output to the output. Device.

Further, in the automatic screw size measuring system of the present invention, it is preferable that the arithmetic control device performs smoothing processing on the boundary of the binarization of the black and white by the following method: when the workpiece is rotated about the Y axis In the contour data of every predetermined angular interval, the preset is on the edge Low-pass filtering of a predetermined frequency of the trajectory of the measured data in the Y direction of the workpiece.

Further, in the automatic screw size measuring system of the present invention, it is preferable that the arithmetic control device is a profile of a boundary between binarization of black and white, and a contour of every predetermined angular interval obtained when the workpiece is rotated about the Y axis. Data, predicting the deviation of the Y direction caused by the deviation of the workpiece at predetermined angles, and the X-direction position of the point predicted based on the plurality of points corrected by the deviation predicted by the angle of the corresponding workpiece about the Y-axis The trajectory is low-pass filtered to generate contour data after filtering, and the value of the dimension of the workpiece around the Y-axis is calculated according to the contour data after the filtering process and output to the output device.

In the automatic screw size measuring system of the present invention, preferably, the workpiece is a cap screw having a head and a threaded shaft portion and having a rotating groove or a rotating hole for fastening a tool at the head, and the optical measuring device includes the measuring workpiece. The head measuring portion of the depth of the head hole.

In the automatic screw size measuring system of the present invention, preferably, the head measuring unit has a head imaging camera that captures a shape of a head hole of the workpiece on a photographing surface parallel to the XZ plane; the laser light source is opposite to the laser light source a predetermined inclination angle of the workpiece in the Y direction, irradiating a light beam extending linearly on the XZ plane over the upper surface of the head of the workpiece and the bottom surface of the head hole; the arithmetic control device includes: a head size calculation unit, according to the head The photographing data of the camera camera calculates the head size of the workpiece, and the head hole depth calculating unit detects the projection of the linear light beam emitted from the laser light source on the upper surface of the head and the bottom surface of the head hole by the head imaging camera. Bit And determining the depth of the head hole according to the amount of misalignment on the XZ plane of each detected projection position and the predetermined tilt angle.

According to the configuration of the present invention, the screw size automatic measurement system has a grip portion that grips one end of the male screw of the workpiece to be measured in the axial direction. Further, the automatic screw size measuring system is such that the grip portion is rotationally driven 360 degrees around the axial direction, and the optical measuring device that optically and non-contactly measures the size of the workpiece is relatively moved in the axial direction with respect to the grip portion. Thereby, the screw which is a workpiece to be measured is attached only once to the grip portion, and various dimensions in the axial direction and the axis of the workpiece can be automatically measured.

Further, in the present invention, the grip portion may be constituted by an adapter having a disc-shaped outer shape and having a female thread of a predetermined engagement length at the center of one end face, the female thread of the predetermined engagement length When screwing into the front end portion of the male screw of the workpiece, it is fixed so that the axial direction of the workpiece does not shake. According to this configuration, even if the workpiece is rotated about the axis, stable measurement can be performed.

Further, in the present invention, the reference female thread of the ring gauge has an accurate mother base according to the configuration of the ring gauge of the reference female thread having the predetermined meshing accuracy corresponding to the thread size of the male thread of the workpiece. Thread shape. Therefore, if the workpiece is a good product, the full thread portion is engaged with the reference female thread by about one pitch, thereby being firmly fixed without causing the axial movement of the workpiece. Further, the disc-shaped bracket having the male thread that meshes with the reference female thread of the ring gauge protrudes from the one end side, regardless of the screw size of the workpiece, the disc shape of the bracket has a common shape, and therefore, by using the fastening The chuck holds the common shape and can easily correspond to various nominals. Determination of the size of the screw.

Further, in the present invention, the grip portion may be rotatably provided in the axial direction on the upper surface of the base having the upper surface parallel to the XZ plane, and be movable in the Y direction with respect to the base to An optical measuring device including an image projection unit that measures the axial direction of the workpiece and the size of the axis is mounted on the Y stage at an arbitrary Y position. According to this configuration, the grip portion is rotated about the axis, and the Y table is moved in the Y direction, whereby the image projection portion can automatically measure the size of the workpiece in the axial direction and the axis.

Further, the present invention can be configured such that the image projection unit has a parallel light source disposed on one side in the Z direction with respect to the center line of the workpiece in the Y direction, and is disposed in the Z direction center line with respect to the workpiece. A projection camera camera of the telecentric optical system on the other side of the direction. According to this configuration, the shape data of the workpiece can be accurately obtained.

Further, the present invention can be configured such that the arithmetic control device binarizes black and white in two-dimensional data of a bit map having an arbitrary position resolution of projection shape data of a screw imaged by a projection imaging camera. In the data of the junction, the abnormal data is observed as a noise and is removed from the cross-sectional view of the screw, and the contour data indicating the contour distribution of the screw is obtained. According to this configuration, the noise caused by the garbage or the like adhering to the workpiece can be removed by the soft body processing, so that the axial direction of the workpiece and the size around the axis can be accurately calculated and output.

Further, the present invention can be configured to calculate a focus position in an edge region where the projection shape data of the screw imaged by the projection imaging camera is converted from the white data to the black data. General autofocus system Focusing can be performed on the surface of the object, but the contour of the screw is distributed as the edge of the shaft-shaped diameter, so the focus position is extremely narrow. In the above configuration, an evaluation function that is preset so as to obtain a maximum value in the black-and-white boundary of the projected shape data is used, so that the focus position can be accurately obtained.

Further, the present invention can be configured such that the measurement data of the size of the workpiece around the Y-axis is obtained for the contour data of the workpiece at predetermined angular intervals, and the predetermined lower limit threshold is removed. Measurement data of the size of the axis around the range of the preset upper limit threshold. Further, the configuration is such that the value of the size around the Y-axis is calculated from the remaining group of measurement data of the size around the Y-axis. According to this configuration, even when foreign matter adheres to the screw, the value of the dimension around the Y axis can be calculated with higher precision.

Further, the present invention can be configured as follows. When the workpiece is a cap screw, the measurement of the head hole cannot be performed using the projection shape data. Therefore, the optical measuring device includes the image projection portion and the measurement workpiece. A head measuring portion of the depth of the head hole. Thereby, non-contact optical measurement of the measurement of the head hole can also be performed.

Further, in the present invention, the hole depth may be measured by irradiating the XZ plane over the upper surface of the head of the workpiece and the bottom surface of the head hole at a predetermined inclination angle with respect to the Y direction of the workpiece. A laser beam extending in a straight line; the projection position of the linearly extending beam is offset from the top surface of the head and the bottom surface of the head hole according to the depth of the hole. Thereby, the measurement of the head hole depth can be performed by non-contact optical measurement without using a gauge or the like.

2‧‧‧ Male thread

3‧‧‧ lower head

4‧‧‧ head

5‧‧‧Upper surface

6‧‧‧ head hole

8‧‧‧Workpiece

10‧‧‧Automatic screw size measurement system

12‧‧‧Automatic screw size measuring device

14‧‧‧Anti-vibration table

15‧‧‧ frame

16‧‧‧Abutment

18, 19‧‧ ‧ pillar

20‧‧‧ top board

22, 23‧‧‧ rails

24, 25‧‧ ‧ threaded column

26‧‧‧Y stage

27, 28‧‧ ‧ bearing department

29‧‧‧Y motor

30‧‧‧ Sensor

31‧‧‧Land

32‧‧‧Optical measuring device

32a‧‧‧Optical measuring device

34‧‧‧Image Projection Department

34a‧‧‧ Head Measurement Department

36‧‧‧Light source

38‧‧‧Photo Camera

40, 40a‧‧‧ Head Measurement Department

42‧‧‧ head camera

44‧‧‧Laser light source

45‧‧‧Actuator

46‧‧‧Circular Lighting Department

48‧‧‧Installation board

50‧‧‧Focus Moving Department

52‧‧‧Z stage

54‧‧‧Z motor

56‧‧‧Removal of the mobile department

58‧‧‧X stage

60‧‧‧Piston cylinder mechanism

62‧‧‧ Holding the rotating part

64‧‧ θ motor

66‧‧‧Rotary joints

68‧‧‧The Department of Control

70‧‧‧ fastening chuck

72‧‧‧Support table

74a, 74b, 74c‧‧‧ slide table

76a, 76b, 76c‧‧‧ gripping claws

78a, 78b‧‧‧Pistons

80‧‧‧Adapter

82a‧‧‧Circle

83a‧‧‧ reference female thread

84a‧‧‧shims

86‧‧‧ bracket

90‧‧‧stop flange

92a‧‧‧ male thread

100‧‧‧ arithmetic control device

102‧‧‧Air pressure control device

104‧‧‧Output device

106‧‧‧Checklist

110‧‧‧Thread diameter calculation unit

112‧‧‧Full-time calculation department

114‧‧‧Focus position calculation unit

116‧‧‧ Outline Data Calculation Department

118‧‧‧The first R calculation department

120‧‧‧ Head size calculation department

122‧‧‧ Head hole depth calculation unit

124‧‧‧Measurement data output department

133, 134, 135, 136, 137‧‧ red lines

142‧‧‧Black and white junction

144‧‧‧ bend line

145, 146, 148, 150‧‧‧ Location of black material

162, 163‧‧‧ straight line

166, 167‧‧‧ vertical line

170, 171‧‧‧ Outline data

172‧‧‧Return to the straight line

Line 173‧‧

176‧‧‧Return to the straight line

180, 180b, 180c‧‧‧ head hole drill

182b‧‧‧ head hole fitting

184‧‧‧Flange

186‧‧‧Cylinder

188‧‧‧ cone top

190‧‧‧column components

194‧‧‧Actuator housing

195‧‧‧ Guide hole

196‧‧‧Y workbench

198‧‧‧Sliding feet

200‧‧‧ position sensor

202‧‧‧moving components

204‧‧‧Fixed side members

210‧‧‧Drill Clamping Unit

211‧‧‧ Lifting members

214‧‧‧ Guide members

216‧‧‧ telescopic arm

218‧‧‧Piston cylinder mechanism

220‧‧‧Drill Bit Control Department

221‧‧‧ claws

222‧‧‧Up and down pole

230‧‧‧Under fixed workbench

232‧‧‧Z mobile workbench

234‧‧‧Linear actuator

236‧‧‧Rotating components

238‧‧‧Rotary joint

240‧‧‧ Pulley

244‧‧‧Land

250‧‧‧Upper fixed workbench

252‧‧‧ head camera moving department

254‧‧‧ pole

256‧‧‧Piston cylinder mechanism

Fig. 1 is a configuration diagram of an automatic screw size measuring system according to an embodiment of the present invention, and is a front view of the automatic screw size measuring device. Fig. 2(a) is a left side view of the automatic screw size measuring device of Fig. 1. (b) is a plan view of the screw size automatic measuring device of Fig. 1; and Fig. 3 is a view showing a grip portion of the automatic screw size measuring system according to the embodiment of the present invention and a screw to be gripped as a workpiece to be measured, (a) is a side view of the fastening chuck, (b) is a side view of the adapter, (c) is a view showing a screw of the workpiece to be measured, and (d) is an exploded view of the adapter. (e) to (g) are plan views corresponding to (a) to (c); Fig. 4 is a view showing an adapter of each measurement target workpiece having a different nominal size, (a in Fig. 4) ) is a view showing an adapter for the thread of M12, (b) is a view showing an adapter for a thread of M6, (c) is an adapter for a thread of M3, and FIG. 5 is a view showing the present invention. A flowchart of the measurement procedure of the screw size automatic measurement system according to the embodiment; and FIG. 6 is a view showing the measurement site corresponding to the measurement sequence of FIG. Fig. 6(a) shows a measurement site in a side view, (b) is a view showing a measurement site in a plan view, and Fig. 7 is a view showing measurement of a header hole depth in Fig. 5, and a seventh diagram. (a) is a view showing an arbitrary holding state in the workpiece to be measured, and (b) is a view showing a state in which the workpiece to be measured is rotated about the axis from the state of (a), and (c) is a view showing that the workpiece is rotated. The light source is along the Y side with respect to the workpiece to be measured FIG. 8 is a view showing a method of calculating a focus position in the automatic screw size measurement system according to the embodiment of the present invention, and FIG. 8(a) is a view showing a state in which the depth of the head hole is measured in the moving position. (b) is a view showing a black-and-white state captured when the focus position of the projection imaging camera is from A to E, and (c) is a diagram showing a change in the black-and-white state by a change in the grayscale value I. (d) is a graph showing a differential waveform of the gray scale value I with respect to the Z position, and (e) is a graph showing the relationship between the half value width (half value width) of the waveform of (d) with respect to the Z position; FIG. 9 is a view showing a method of removing noise of a contour distribution in the automatic screw size measuring system according to the embodiment of the present invention, wherein (a) of FIG. 9 is a view showing a rule of contour tracking processing, and (b) is a measurement target. The screw profile distribution obtained by the contour tracking process of the workpiece, (c) is a map showing the contour data for removing noise from (b), and FIG. 10 is a diagram showing the measurement of the head R below in FIG. (a) in the figure is a diagram showing outline data of the lower portion of the head of the workpiece to be measured, and (b) is a diagram showing the head. Fig. 11 is a view showing measurement of the top diameter in Fig. 5, and Fig. 11(a) is a view showing outline data along the axial direction of the workpiece to be measured, (b) It is a figure which finds the regression line of the outline data of the top of (a), (c) is a figure which shows the calculation method of the top diameter, and FIG. 12 is a figure which shows the measurement of the bottom diameter of FIG. (a) is a graph showing contour data along the axial direction of the workpiece to be measured, (b) is a graph showing the regression line of the contour data at the bottom of (a), and (c) is a method for calculating the bottom diameter. Map Fig. 13 is a view showing another method of measuring the depth of the head hole, and Fig. 13(a) is a side view showing a state in which a predetermined head hole drill bit is inserted into the head hole, (b) FIG. 14 is a plan view showing a head hole drill for each workpiece to be measured having a different nominal size, and FIG. 14( a ) is a head for a screw for M12. (b) is a view showing a head hole drill for a screw of M6, (c) is a view showing a head hole drill for a screw of M3, and Fig. 15 is a view showing the construction of the present invention. FIG. 16 is a right side view of the automatic screw size measuring device of FIG. 15 and FIG. 17 is a view showing the screw of FIG. (a) of FIG. 17 is a view showing a state in which the head imaging camera is retracted to the right side in the plan view, and (b) is a state in which the head imaging camera is moved to the imaging position. Top view; Figure 18 is a top view of the screw size automatic measuring device in Fig. 15. FIG. 19 is a view showing a bit clamping unit in a left side view of FIG. 15, and FIG. 20 is a view showing another example of an automatic screw size measuring system according to an embodiment of the present invention. A map for calculating the top diameter and the bottom diameter at a predetermined angle after calculating the contour data, and is an enlarged view of FIG. 12(c); (a) of FIG. 21 is a curve connecting a top diameter d max of a predetermined angle. And the measurement data of the bottom diameter d min and the relationship with the angle θ, (b) is a cross-sectional view of a part of the axial direction of the workpiece as a screw, and FIG. 22 is a measurement data of the top diameter d max at a predetermined angle. The ideal model in the relationship with the number of measured data (a) and the figure (b) in the case where the measurement data of the predetermined range is excluded from the case; the 23rd figure shows the outline data at a predetermined angle to the workpiece. In the case of low-pass filtering, the first screw contour distribution of the workpiece (a) and the second screw contour distribution (b) after the filtering process; and Figs. 24 (a) to (c) show the predetermined workpiece. In the case of the outline data of the angle, when the abnormal portion in the X direction is removed by the low-pass filter, the change of the screw contour distribution at the time of rotating the workpiece at a predetermined angle is obtained; and FIG. 25 is a view showing the contour distribution at the workpiece. A part of the trajectory (a) before the filtering process and the trajectory (b) after the filtering process in the case where the trajectory of the X-direction position of the predetermined angle is removed by a low-pass filter; The figure shows another adapter for fixing the workpiece An example of a map corresponding to Fig. 4.

Embodiments of the present invention will be described in detail below with reference to the drawings. Hereinafter, as the workpiece to be measured, a bolt having a hexagonal hole with a nominal diameter of 30 mm and a nominal length of 30 mm will be mainly described, but this is an illustration for explanation. In terms of the type of thread, in addition to the metric coarse thread, it can also be a metric fine thread, a tapered pipe thread, a parallel pipe thread, or Thick thread, uniform coarse thread, uniform fine thread, micro thread, metric trapezoidal thread. In addition, it may be a screw having a nominal length of 30 mm or more. The head hole may be a slot (negative groove), a cross hole, a positive and negative hole, a square hole, a TORX (registered trademark), and the like, in addition to a rotary groove or a rotary hole or a hexagonal hole for a fastening tool provided on the head. A hexagonal hole such as a TORX PLUS (registered trademark) such as a modified version, that is, a hexagonal hole or a triangular hole. Alternatively, the head may not be provided, and the head may be provided without a head hole.

The shape, the size, the material, the measurement site, and the like described below are exemplified for explanation, and can be appropriately changed in accordance with the specifications of the screw size automatic measurement system. In the following, the same components are denoted by the same reference numerals throughout the drawings, and overlapping description will be omitted.

Fig. 1 is a configuration diagram of an automatic screw size measuring system 10 according to an embodiment. The screw size automatic measurement system 10 is configured to include a screw size automatic measuring device 12, an arithmetic control device 100, and an air pressure control device 102. The screw size automatic measuring device 12 is configured to include an anti-vibration table 14 and a base 16 disposed inside the casing 15 provided on the vibration isolating table 14. A front view of the screw size automatic measuring device 12 is shown in Fig. 1 . Fig. 2 is a left side view and a plan view showing an inner portion of the casing 15 of the automatic screw size measuring device 12. Fig. 2(a) is a left side view, and Fig. 2(b) is a plan view. In the first and second figures, the orthogonal X direction, Y direction, and Z direction are shown. The XZ plane is a plane parallel to the upper surface of the base 16, and a direction perpendicular to the upper surface of the base 16 is a Y direction parallel to the direction of gravity. The X direction is the left and right direction in the left side view, and the Z direction is the left and right direction in the front view.

Although not the composition of the screw size automatic measuring device 12 Element, but indicates the workpiece 8 to be measured. The workpiece 8 is a bolt with a hexagonal hole nominally M12 and having 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 column portions 18 and 19 which are erected in parallel with the Y direction from the upper surface of the base 16 and the top plate portion 20 which connects the upper end portions of the two column portions 18 and 19 form a frame space together with the base 16 . Rails 22, 23 are respectively provided on the opposing faces of the column portions 18, 19, and the screw posts 24, 25 are parallel to the Y direction from the upper surface of the base 16 on the inner side sandwiched by the guide rails 22, 23. Set upright. The threaded posts 24, 25 are rotatable shafts that are journaled in the axial direction on the outer peripheral surface and are rotatably supported by the base 16. The ends of the threaded posts 24, 25 in the -Y direction project downward from the upper surface plate of the base 16, and are respectively provided with pulleys.

As shown in Fig. 2(b), the Y stage 26 has sliding portions slidable along the guide rails 22, 23 at both ends in the Z direction, and is provided with two sets of bearing portions 27, 28 and the upper surface is flat. Workbench. Among the two sets of bearing portions 27 and 28, one bearing portion 27 is provided on the +Z side of the guide rail 22, and the other bearing portion 28 is provided on the -Z side of the guide rail 23. The two sets of bearing portions 27, 28 are formed by ball nuts that mesh with screws engraved on the outer circumference of the threaded posts 24, 25. The threaded posts 24, 25 engraved with a male thread on the outer circumference and the bearing portions 27, 28 including the ball nut constitute a ball screw mechanism, and the screw posts 24, 25 correspond to a ball screw for a ball screw mechanism. The Y stage 26 is a moving table that is guided by the guide rails 22 and 23 to move in the Y direction by the action of the ball screw mechanism.

A servo motor that rotationally drives the threaded posts 24, 25, that is, a Y motor 29, is attached to the base 16. The output shaft of the Y motor 29 protrudes downward from the upper surface plate of the base 16, and is provided with a pulley. The belt 31 is a power transmission member that is stretched between a pulley provided on the output shaft of the Y motor 29 and a pulley provided at the end in the -Y direction of the screw columns 24 and 25. As the three pulleys, a timing pulley provided with irregularities along the circumferential direction can be used, and as the belt 31, a timing belt having irregularities on the surface can be used. As the Y motor 29, an AC servo motor can be used.

The Y motor 29 is a lifting motor that is driven by the arithmetic control device 100 to rotate the screw posts 24 and 25 and to raise and lower the Y stage 26 in the Y direction. A sensor 30 that detects the rotation state of the output shaft is provided on the Y motor 29. A sensor that detects the respective rotational states of the threaded posts 24, 25 may also be provided. As the sensor 30, an encoder can be used. The detected data detected by the sensor 30 is transmitted to the arithmetic control device 100 using an appropriate signal line. The arithmetic control device 100 calculates the Y-direction position of the Y stage 26 based on the transmitted data. In this manner, the sensor 30 provided on the Y motor 29 or the screw posts 24, 25 is a Y sensor that detects the position of the Y stage 26 in the Y direction. As the sensor 30 which is a Y sensor, a position sensor that directly detects the Y-direction position of the Y stage 26 may be used instead of the sensor that detects the rotation state of the Y motor 29. As the position sensor, an optical sensor of a linear scale method, a differential shift type displacement sensor that detects displacement of a magnetic body, a displacement type displacement sensor, or the like can be used.

The Y motor 29, the belt 31, the threaded posts 24, 25, and the bearing portions 27, 28 provided on the Y stage 26 are configured to be along the Y with respect to the base 16 The axial movement portion of the Y stage 26 is moved in the direction.

The optical measuring device 32 mounted on the upper surface of the Y stage 26 is a measuring device that measures the size and shape of the workpiece 8 optically and non-contactly. The optical measuring device 32 is configured to include an image projecting unit 34 that measures the axial direction of the workpiece 8 and a size around the axis, and a head measuring unit 40 that measures the size of the head of the workpiece 8 and the depth of the head hole.

The image projecting unit 34 has a light source 36 that is disposed on one side in the Z direction with respect to the center line of the workpiece 8 in the Z direction and outputs parallel rays; the projection imaging camera 38 of the telecentric optical system is oriented with respect to the Y-direction center line of the workpiece 8. The other side disposed in the Z direction receives parallel light rays from the light source 36, and has a projection shape of the image to be the workpiece 8 having the same light receiving optical axis as the light source 36 and only the components parallel to the optical axis are parallel to the XY plane. Shoot on the shooting surface for imaging. As the light source 36, a light source having an appropriate light parallelizing means such as a collimator or a light source including a telecentric optical system can be used. As the projection imaging camera 38, a CCD camera to which a CCD image sensor is applied or a camera device to which a CMOS image sensor is applied can be used. For example, a CCD camera having a pixel of about 8 μm and an imaging surface having a size of about 20 mm can be used.

The arrangement position of the light source 36 of the image projecting unit 34 is provided on the +Z side from the center of the Y stage 26, and is fixed to the Y stage 26. The projection imaging camera 38 is provided on the -Z side from the center of the Y stage 26, but is mounted on the focusing moving unit 50 provided on the Y stage 26, and is movable in the Z direction. A portion in which the projection imaging camera 38 and the focusing moving unit 50 are combined is a projection imaging unit.

The focus moving unit 50 is configured to include a Z stage 52 that is movable in the Z direction with respect to the Y stage 26 and a Z motor 54 that moves the Z stage 52 in the Z direction. The operation of the Z motor 54 is controlled by the arithmetic control device 100. The function of the focus moving unit 50 will be described later using Fig. 8 . As the Z motor 54, an AC servo motor or a DC servo motor can be used.

The head measuring unit 40 is configured to include a head imaging camera 42 that captures a shape of a head hole of the workpiece 8 on an imaging surface parallel to the XZ plane, and a predetermined inclination angle with respect to the Y direction of the workpiece 8 and The upper surface of the head of the workpiece 8 and the bottom surface of the head hole illuminate the laser light source 44 of the light beam extending linearly on the XZ plane. The beam of the laser light source 44 extends linearly in parallel with the Z direction. The actuator 45 is a driving device that moves the laser light source 44 in the Y direction. As the actuator 45, a small motor can be used. The head hole depth measuring method using the linearly extending laser beam will be described with reference to Fig. 7.

The head imaging camera 42 is an imaging camera in which the imaging surface facing the upper surface of the head of the workpiece 8 is parallel to the XZ plane. As the head imaging camera 42, a CCD camera to which a CCD image sensor is applied or a camera device to which a CMOS image sensor is applied can be used. The ring illumination unit 46 is an annular lamp that is provided on the −Y direction side of the head imaging camera 42 to illuminate the upper surface of the workpiece 8 . The head camera camera 42, the laser light source 44, and the ring illumination unit 46 are positioned in a relative arrangement relationship, and are fixedly mounted to the mounting board 48.

The retreating moving portion 56 is capable of moving the mounting plate in the X direction The mechanism of 48 is configured to include an X stage 58 that is movable in the X direction, and a piston cylinder mechanism 60 that moves the X stage 58 in the ±X direction by a predetermined movement distance L. The piston cylinder mechanism 60 is operated under the control of the arithmetic control device 100, and the piston is reciprocated by a distance of ±L by the air pressure supplied from the air pressure control device 102.

When the piston performs +L movement, the head imaging camera 42, the laser light source 44, and the ring illumination portion 46 attached to the mounting plate 48 are integrally moved in the +X direction, and the optical axis of the head imaging camera 42 is just right. To the center of the head of the workpiece 8. This state is a measurement state in which the measurement of the shape of the head and the measurement of the depth of the hole can be performed. When the piston moves -L, the head imaging camera 42, the laser light source 44, and the ring illumination portion 46 attached to the mounting plate 48 are integrated and retracted in the -X direction. In this state, even if the Y stage 26 is lowered in the -Y direction, the head imaging camera 42 or the like does not interfere with the retracted state of the workpiece 8.

The grip portion 68 is a device that is disposed on the base 16 through the grip rotating portion 62 and holds one end of the male screw in the axial direction of the workpiece 8. The grip portion 68 is configured to include an adapter 80 having a disk-shaped outer shape and a fastening chuck 70 that sandwiches the outer peripheral side surface of the adapter 80 at least three points. The grip rotating portion 62 is configured to include a θ motor 64 that rotates the fastening chuck 70 360 degrees in the axial direction, and a rotary joint portion 66 that is provided between the θ motor 64 and the fastening chuck 70.

The rotary joint portion 66 is an air pressure relay portion when the air pressure from the air pressure control device 102 is supplied to the fastening chuck 70. The rotary joint portion 66 has a relay function, and the supply pipe for supplying air pressure does not Winding due to the axial rotation of the fastening chuck 70. The rotation operation of the θ motor 64 is controlled by the arithmetic control device 100. As the θ motor 64, an AC servo motor or a DC servo motor can be used.

FIG. 3 is an exploded view showing details of the grip unit 68. Here, the detailed configuration of each of the fastening chuck 70 constituting the grip portion 68, the adapter 80 fixed by the fastening chuck 70, and the workpiece 8 held by the adapter 80 is shown. 3(a) to (c) are cross-sectional views showing the fastening chuck 70, the adapter 80, and the workpiece 8, respectively, (d) showing an exploded view of the adapter 80, and (e) to (g) showing fastening. A top view of each of the chuck 70, the adapter 80, and the workpiece 8.

The workpiece 8 includes a male screw portion 2, a head portion 4, a male lower portion 2, and a head lower portion 3 between the head portions 4. The head portion 4 is provided with a hexagonal head hole 6. The workpiece 8 is a metric coarse thread of nominal M12 with a nominal length of 30 mm. According to the Japanese industrial specifications, the length of the fixing screw in the male thread portion 2 is about 30 mm, the maximum diameter of the male thread portion 2 is about 13.7 mm, the pitch of the screw is 1.75 mm, and the reference outer dimension of the head 4 is 18 mm. The reference height dimension of the portion 4 is 12 mm, the head hole 6 is a hexagonal hole, the nominal dimension of the opposite side width is 10 mm, the minimum dimension of the hole depth is 6 mm, and the radius of the maximum state of the circular shape of the lower head 3 is the head under the head. R is a minimum of 0.6 mm. The opposite side width is the dimension between the opposite sides of the hexagon. The bottom surface of the head hole 6 is not flat but has a conical shape with an opening angle of 120 degrees. The incomplete thread portion of the male thread portion 2 has a maximum of two pitches, and in the present case, 2 pitches = 3.50 mm.

The fastening chuck 70 is disposed on the support base 72 with the three slide tables 74a, 74b, and 74c whose front end portions face each other. In the initial state, The three slide tables 74a, 74b, and 74c are retracted to the outer peripheral side of the support base 72. The three slide tables 74a, 74b, and 74c are synchronized by the pistons 78a and 78b of the piston-cylinder mechanism that are operated by the air pressure supplied from the air pressure control device 102, and are on the outer peripheral side and the central axis side of the support base 72. Move between drives.

Clamping claw portions 76a, 76b, and 76c are attached to the three sliding tables 74a, 74b, and 74c, respectively. The front end portions of the three grip claw portions 76a, 76b, and 76c are disposed toward the central axis direction of the support base 72, respectively. In the initial state, the grip claw portions 76a, 76b, and 76c are also retracted to the outer peripheral side of the support base 72. The three slide tables 74a, 74b, and 74c are synchronously moved in the direction of the central axis of the support base 72, whereby the front end portions of the grip claw portions 76a, 76b, and 76c are synchronized in the center axis direction of the support base 72. When the adapter 80 placed at the center of the support base 72 is centered so as to be aligned with the position of the central axis, the fastening state of the outer circumferential side surface of the adapter 80 is clamped and fixed. In this manner, the fastening chuck 70 is a three-division chuck mechanism that is moved by air between the retracted state and the tightened state.

The centering clamping operation of the fastening chuck 70 is performed under the control of the arithmetic control device 100. The clamping of the adapter 80 by the fastening chuck 70 is performed at the front end portions of the three clamping claw portions 76a, 76b, and 76c. The front end portions of the three gripping claw portions 76a, 76b, and 76c are flat surfaces, respectively. Therefore, when the outer shape of the adapter 80 is a disc shape, the outer peripheral side surface thereof is three points, specifically, in the axial direction. The three tangent lines are clamped. The clamping of the outer peripheral side of the adapter 80 may be performed at least at three points. For example, it can also be set In other words, the shape of the front end portion of the grip claw portion is V-shaped, and the outer peripheral side surface of the adapter 80 is sandwiched by the opposing grip claw portions. In this case, the outer peripheral side surface of the adapter 80 is sandwiched at four points.

The adapter 80 is a workpiece fixing jig having a disk-shaped outer shape portion held by the fastening chuck 70, and has a female thread of a predetermined engagement length at the center of one end surface, the female screw being screwed into the workpiece 8 When the front end portion of the male screw portion 2 is fixed, the axial direction of the workpiece 8 is not shaken.

The adapter 80 is a ring gauge 82a that screwes a front end portion of the male screw portion 2 of the workpiece 8 into a predetermined engagement length, a bracket 86 having a disk-shaped outer shape portion held by the fastening chuck 70, and The spacer 84a disposed between the ring gauge 82a and the bracket 86 is integrated.

The ring gauge 82a is a member having a disk shape and having a reference female thread 83a engraved along its central axis. The reference female thread 83a is a female thread corresponding to the thread size of the male thread portion 2 of the workpiece 8 and having a predetermined meshing accuracy. The ring gauge 82a can directly use a thread outer diameter gauge for thread inspection. The standard thread outer diameter gauge is engraved with a reference pitch female thread 83a of 8 pitches in the case of M12. Since 1 pitch = 1.75 mm, the thickness of the ring gauge 82a is precisely managed to 8 pitches = 14.00 mm. The reference female thread 83a does not have an incomplete thread portion.

The front end portion of the male screw portion 2 of the workpiece 8 is screwed in from the one end surface side of the ring gauge 82a, that is, the upper surface side with a predetermined meshing length. The predetermined engagement length is set so as not to be shaken in the axial direction of the workpiece 8 when the tip end portion of the male screw portion 2 of the workpiece 8 is screwed into the reference female screw 83a of the ring gauge 82a. Preferably, the axial sway of the workpiece 8 is zero, but It is permissible as long as it does not affect the measurement accuracy of various dimensions of the workpiece 8. If the workpiece 8 is a good product, the effective thread portion of the male thread portion 2 of the workpiece 8 is made to have about one pitch; if it is engaged with the reference female thread 83a of the ring gauge 82a, the axial sway of the workpiece 8 is substantially allowed to fall within the allowable range. . The male thread portion 2 of the workpiece 8 has a maximum threaded portion of two pitches, so that the screwing amount of the workpiece 8 is a predetermined meshing length (the length of the pitch number of the incomplete thread portion + the length of one pitch of the full thread portion) It is preferable to set it as long as possible.

The ring gauge 82a has high precision for thread inspection of the workpiece 8, so that the workpiece 8 cannot be screwed into the ring gauge 82a with a predetermined meshing length, and the workpiece 8 becomes a defective product. Therefore, the tip end portion of the reference female screw 83a of the workpiece 8 which is screwed into the ring gauge 82a is determined as a good portion. However, since this part cannot be quantitatively measured by the screw size automatic measuring system 10, it is preferable to set the predetermined meshing length as short as possible. As described above, the viewpoint of reducing the axial sway of the workpiece 8 is contrary to the viewpoint of expanding the range in which the screw size automatic measurement system 10 can perform quantitative measurement.

Therefore, the following is assumed to be a predetermined engagement length = length of three pitches of the male screw portion 2 of the workpiece 8 = 5.25 mm. The predetermined engagement length is set to be a length of three pitches which is an integral multiple of the length of one pitch, because the screwing depth of the tip end portion of the male screw portion 2 of the workpiece 8 to the ring gauge 82a is set to one pitch. An exact value that is an integer multiple. The workpiece 8 is a metric coarse thread with a nominal M12 thread and a nominal length of 30 mm. According to Japanese Industrial Standards, the incomplete thread portion of the male thread portion 2 has a maximum of two pitches. Therefore, the two largest pitches plus one pitch will be predetermined The combined length is set to a length of three pitches so that at least one pitch is engaged at the full thread portion.

It should be noted that in the case of the workpiece 8 having a low quality level, the incomplete thread portion may be equal to or greater than two pitches, and even if the mesh length is set to a length of three pitches, the workpiece 8 may be shaken in the axial direction. . In this case, the predetermined engagement length is extended from the length of the three pitches in units of the length of one pitch. For example, the predetermined engagement length is set to a length of 4 pitches or a length of 5 pitches. On the other hand, in the case of processing a screw for high precision or the like and the incomplete thread is inserted into one pitch or less, the predetermined meshing length can be shortened from the length of three pitches in units of the length of one pitch. For example, the predetermined engagement length can also be set to the length of two pitches. The adjustment of one pitch unit of the predetermined meshing length is performed by increasing or decreasing the number of the spacers 84a as will be described later.

The bracket 86 is a disk-shaped member having an end surface that protrudes from the male screw 92a that meshes with the reference female screw 83a of the ring gauge 82a, that is, the upper surface. When the side where the male screw portion 2 of the workpiece 8 is screwed into the ring gauge 82a is set as the upper surface side of the ring gauge 82a, the male screw 92a of the bracket 86 is screwed from the lower surface side of the ring gauge 82a. The disc-shaped portion of the bracket 86 has a clamp ring portion 88 and a stopper flange portion 90 having an outer diameter larger than that of the clamp ring portion 88 to accurately position the Y direction when clamped by the fastening chuck 70. Even if the nominal size of the workpiece 8 is different, the clamp ring portion 88 has the same outer diameter to normalize the fastening chuck 70, which is preferable. Here, the outer diameter of the clamp ring portion 88 is set to 20 mm, and the outer diameter of the stopper flange portion 90 is set to 35 mm. The lower surface of the end surface on the -Y direction side of the stopper flange portion 90 and the fastening chuck 70 The upper surfaces of the three gripping claw portions 76a, 76b, and 76c abut, thereby accurately positioning the Y direction when the bracket 86 is held by the fastening chuck 70. It should be noted that by partially cutting the outer circumference of the stopper flange portion 90, when the bracket 86 is placed on a work table or the like, the bracket 86 can be prevented from rolling.

The male screw 92a protrudes from the upper surface of the one end surface of the stopper flange portion 90 as the bracket 86 by a predetermined amount of protrusion. The male thread 92a can also have an incomplete threaded portion.

The length of the reference female thread 83a of the male thread 92a screwed into the ring gauge 82a is precisely set to: {(thickness of the ring gauge 82a) - (the predetermined meshing length of the male thread portion 2 of the workpiece 8 engaged with the ring gauge 82a)}. In the above case, it is set to: {(thickness of the ring gauge 82a) - (the predetermined meshing length at which the male screw portion 2 of the workpiece 8 meshes with the ring gauge 82a)} = {(the length of the eight pitches) - (3 Length of pitch)}=(length of 5 pitches)=(14.00mm-5.25mm)=8.75mm.

The predetermined amount of protrusion of the male screw 92a from the stopper flange portion 90 can also be set to (the length of the five pitches) = 8.75 mm, but it can be set to a ratio (5) in consideration of forming the lower portion of the head portion of the male thread 92a. The length of the pitch) = 8.75 mm long. When set to be longer, increase the length of the integer multiple of the pitch. Thereby, the protruding amount of the male screw 92a is exactly an integral multiple of the pitch, and the screwing depth of the tip end portion of the male screw portion 2 of the workpiece 8 to the ring gauge 82a can be set to an exact value of an integral multiple of one pitch. Here, the amount of protrusion of the male screw 92a = (the length of 7 pitches) = 12.25 mm.

When the male thread 92a of the bracket 86 is engaged with the reference female thread 83a of the ring gauge 82a from the lower surface side of the ring gauge 82a, and the workpiece 8 is made When the distal end of the male screw portion 2 is screwed into the reference female screw 83a of the ring gauge 82a from the upper surface side of the ring gauge 82a, the distal end portion of the male screw portion 2 of the workpiece 8 is stopped at the position of the tip end of the male screw 92a of the bracket 86. The screwing depth of the front end portion of the male screw portion 2 of the workpiece 8 to the ring gauge 82a is (the predetermined meshing length of the male screw portion 2 of the workpiece 8 meshed with the ring gauge 82a) as {(thickness of the ring gauge 82a)-( The male thread 92a of the bracket 86 is screwed into the length of the ring gauge 82a).

As described above, the amount of protrusion of the male screw 92a of the bracket 86 may be changed by the length of one pitch, and as described above, the predetermined engagement length of the male screw portion 2 of the workpiece 8 and the ring gauge 82a may be also Adjusted in units of length of one pitch. Even in this case, the screwing depth of the tip end portion of the male screw portion 2 of the workpiece 8 to the ring gauge 82a is set to an exact value of an integral multiple of one pitch. Thereby, the Y position of the front end portion of the male screw portion 2 of the workpiece 8 can be accurately obtained from the measured value of the Y position of the upper surface of the ring gauge 82a. The spacer 84a is used for the adjustment of the one pitch length unit.

The spacer 84a is an annular thin plate having a through hole through which the male screw 92a passes at the center. One spacer 84a has a thickness that accurately corresponds to one pitch of the workpiece 8. In the third drawing, the number of the spacers 84a is shown as two. However, as described in some examples below, the number is not limited to two, and may be one or sometimes three. In the above example, in the case where the thickness of the ring gauge 82a = the length of 8 pitches, and the amount of projection of the male thread 92a of the bracket 86 corresponds to the length of 7 pitches, the stopper flange portion 90 of the bracket 86 and Two spacers 84a having a thickness of one pitch are inserted between the ring gauges 82a. Thereby, the predetermined engagement length of the front end portion of the male screw portion 2 of the workpiece 8 and the ring gauge 82a = [(thickness of the ring gauge 82a) - {(male thread 92a) The amount of protrusion) - (thickness of spacer 84a)}] = [(length of 8 pitches) - {(length of 7 pitches) - (length of two pitches)}] = length of 3 pitches. For example, the position at which the three pitches are lowered in the -Y direction can be accurately determined based on the measured value of the Y position of the upper surface of the ring gauge 82a as the Y position of the tip end portion of the male screw portion 2 of the workpiece 8.

When it is necessary to change the predetermined engagement length of the tip end portion of the male screw portion 2 of the workpiece 8 and the ring gauge 82a from the length of three pitches, the number of insertions of the spacer 84a may be increased or decreased. For example, when the predetermined engagement length is increased from 3 pitches to 4 pitches due to the length of the incomplete thread portion of the male thread portion 2 of the workpiece 8, etc., in the above example, the number of inserts of the spacer 84a is increased. Increase by one. Thereby, the position where the four pitches are reduced in the -Y direction can be accurately determined as the Y position of the tip end portion of the male screw portion 2 of the workpiece 8 based on the measured value of the Y position of the upper surface of the ring gauge 82a. When the predetermined engagement length satisfies the two pitches, in the above example, the number of insertions of the spacer 84a is reduced by one. Thereby, the position where the two pitches are lowered in the -Y direction can be accurately obtained from the measured value of the Y position of the upper surface of the ring gauge 82a as the Y position of the tip end portion of the male screw portion 2 of the workpiece 8.

When it is necessary to change the amount of protrusion of the male screw 92a of the bracket 86 from the length of seven pitches, the number of insertions of the spacer 84a may be increased or decreased. For example, when the protruding amount of the male screw 92a is set to a length of eight pitches from the seven pitches due to the length of the lower portion of the male screw 92a of the bracket 86, the number of insertions of the spacer 84a is increased by one. When the protruding amount of the male thread 92a is only 6 pitches, the number of insertions is reduced. One less. Thereby, even in any case, it is possible to accurately determine the position of the three pitches in the -Y direction as the male thread portion 2 of the workpiece 8 based on the measured value of the Y position of the upper surface of the ring gauge 82a. Y position of the front end.

Thus, the variation of the length of the incomplete thread portion of the male screw portion 2 of the workpiece 8 and the length of the head portion of the male screw 92a of the bracket 86 can be widely dealt with only by the increase or decrease of the number of the spacers 84a. On the other hand, the position of the distal end portion of the male screw portion 2 of the workpiece 8 is a position that is accurately reduced by an integral multiple of the length of one pitch in the -Y direction from the upper surface of the ring gauge 82a of the adapter 80. Thereby, even if the front end portion of the male screw portion 2 of the workpiece 8 is gripped by the adapter 80, the Y position of the upper surface of the ring gauge 82a of the adapter 80 can be measured, and the total length of the workpiece 8 can be calculated by calculation.

Here, the ring gauge 82a, the spacer 84a, and the male screw 92a constituting the adapter 80 have different thicknesses and thread portions depending on the type of the workpiece 8, but regardless of the type of the workpiece 8, the clamp ring portion Both the 88 and the stop flange portion 90 have a common shape and size.

Fig. 4 is a view showing an example of an adaptor depending on the type of the workpiece 8. Here, the adapters corresponding to the types of the three workpieces 8 are shown, but the adapters of the different types of workpieces 8 other than the above may be of the same configuration. Fig. 4(a) shows the case where the thread of the workpiece 8 is nominally M12, which is the same as the adapter 80 described in Fig. 3.

Fig. 4(b) is a view showing the adapter 80b when the thread of the workpiece 8 is nominally M6. The clamp ring portion 88 and the stop flange portion 90 are the same as (a). Here, the pitch of the M6 is 1.00 mm, so the thickness of the ring gauge 82b is The degree is 8 pitches = 8.00 mm, the thickness of one spacer 84b is 1 pitch = 1.00 mm, and the amount of protrusion of the male screw 92b from the stopper flange portion 90 is 7 pitches = 7.00 mm.

Fig. 4(c) is a view showing the adapter 80c when the thread of the workpiece 8 is nominally M3. The clamp ring portion 88 and the stop flange portion 90 are the same as (a). Here, the pitch of the M3 is 0.50 mm, so the thickness of the ring gauge 82c is 8 pitches = 4.00 mm, the thickness of one spacer 84c is 1 pitch = 0.50 mm, and the male thread 92c protrudes from the stopper flange portion 90. The amount is 7 pitches = 3.50 mm.

Returning to Fig. 1, the arithmetic and control device 100 has a function of controlling the operation of each element constituting the automatic screw size measuring device 12 and the air pressure control device 102 as a whole, and calculating the axial direction and the axis of the workpiece 8 The size is transmitted to the output device 104 such as a printer, and printed as the inspection table 106 in the output device 104. The arithmetic control device 100 can be configured using an appropriate computer.

The calculation control device 100 includes a screw diameter calculation unit 110, a total length calculation unit 112, a focus position calculation unit 114, a contour data calculation unit 116, a head-down R calculation unit 118, a head size calculation unit 120, and a head hole depth calculation unit. 122. The measurement data output unit 124 is configured. These functions can be realized by the software executed by the arithmetic control device 100, and specifically, can be realized by executing an automatic screw measurement program. A part of these functions can also be implemented by hardware.

The function, particularly the arithmetic control, of the screw size automatic measuring system 10 constructed as described above will be further described in detail using Figs. 5 to 11. Each function of the device 100. Fig. 5 is a flow chart showing the measurement procedure in the screw size automatic measurement system 10. Fig. 6 is a view showing a measurement portion of the workpiece 8 in each order of the fifth drawing. Fig. 6(a) is a view showing a measurement site in a side view, and Fig. 6(b) is a view showing a measurement site in a plan view.

In order to perform the measurement of the workpiece 8, first, the initialization of the screw size automatic measurement system 10 is performed. In the initialization, the power supply is turned "ON", the air pressure control device 102 is activated, and the arithmetic control device 100 is set to the initial state. Thereby, the Y stage 26 is returned to the predetermined initial Y position. The initial Y position is set to a position sufficiently high with respect to the front end position of the grip portion 68 along the Y direction. Further, the Z stage 52 is returned to the predetermined initial Z position, and the X stage 58 is returned to the retracted state. The grip portion 68 is returned to a predetermined initial θ position. The three gripping claw portions 76a, 76b, and 76c of the fastening chuck 70 are returned to the retracted state.

When the initialization is completed, the workpiece 8 is attached to the grip portion 68 (S10). As described in FIG. 4, the workpiece 8 is gripped by the grip portion 68 to fix the three pitches of the front end portion of the male screw portion 2. In this process, the adapter 80 for M12 is prepared in advance, and the tip end portion of the male screw portion 2 of the workpiece 8 is screwed into the ring gauge 82a of the adapter 80. The adapter 80 for the M12 is set to have three pitches of a predetermined meshing length of M12 = 5.25 mm, so that the workpiece 8 is screwed into 5.25 mm and stopped at this position. Next, the adapter 80 that grips the workpiece 8 is attached to a space between the three gripping claw portions 76a, 76b, and 76c in the retracted state of the fastening chuck 70. The processing so far is performed by the manual work of the operator.

When the workpiece 8 is mounted on the grip portion 68, by the operator The operation control device 100 issues a command to the air pressure control device 102 by pressing a fastening button or the like, and supplies a predetermined fastening air pressure to the piston cylinder mechanism of the fastening chuck 70 of the grip portion 68. Thereby, the three gripping claw portions 76a, 76b, and 76c are simultaneously moved toward the central axis side of the support base 72, and the workpiece 8 is sufficiently fastened and fixed. The shape and size of the workpiece 8 are measured from this state.

After S10, head size measurement is performed (S12). This processing is executed by the function of the head size calculation unit 120 of the arithmetic control device 100. Specifically, the Y stage 26 is lowered, and the focus position of the head imaging camera 42 is exactly the position of the upper surface of the head 4 of the workpiece 8. Further, the head imaging camera 42 acquires the image data of the shape of the head portion 4 of the workpiece 8, binarizes the image data, and calculates the diameter of the head portion 4 and the width of the opposite side of the head hole 6 using an edge detection method or the like. Size, etc. Fig. 6 shows a plan view of the head 4 as S12.

Since the outer shape of the head portion 4 is circular, the workpiece 8 is rotated 360 degrees around the axis at an interval of 1 degree, and the diameter of the head portion 4 is measured repeatedly at each angle. The maximum value, the minimum value, and the average value of these measurement results are taken as the measured values of the diameter size of the head 4. The width of the opposite side of the head hole 6 is the interval between the opposite sides of the hexagonal shape, and the opposite sides of the hexagonal shape are three groups, so that the workpiece 8 is rotated 360 degrees around the axis at an interval of 120 degrees, and three groups are performed. Determination of the width of the side. The maximum value, the minimum value, and the average value of these measurement results were taken as the measured values of the opposite side widths of the head holes 6.

Next, the head hole depth measurement is performed (S14). The head hole 6 is a rotation groove or a rotation hole for connecting a tool provided on the head of the workpiece 8 at In the current case, it is a hexagonal hole. This processing is executed by the function of the head hole depth calculation unit 122 of the arithmetic control device 100. Specifically, the laser light source 44 is irradiated in a straight line on the XZ plane over the upper surface of the head portion 4 of the workpiece 8 and the bottom surface of the head hole 6 at a predetermined inclination angle with respect to the Y direction of the workpiece 8. beam. Further, the projection position of the linearly extending light beam projected on the upper surface of the head 4 and the projection position projected on the bottom surface of the head hole 6 in the XZ plane vary depending on the depth of the head hole 6. .

Fig. 7 is a view showing the procedure for measuring the depth of the head hole 6. Fig. 7(a) is a view showing the workpiece 8 in an arbitrary holding state, and Fig. 7(b) is a view showing a state in which the workpiece 8 is rotated by Δθ about the state of (a), and (c) is a view showing the laser. A diagram in which the position of the head hole depth is measured by ΔY moving the position of the light source 44 with respect to the Y direction of the workpiece 8. In these figures, the upper side view is a plan view of the head 4, and the lower side view is a cross-sectional view of the workpiece 8.

Fig. 7(a) shows a predetermined inclination angle with respect to the Y direction from the laser light source 44 in a state where the opposite sides of the hexagonal shape of the head hole 6 are parallel to the Z direction. The upper surface 5 of the head and the bottom surface 7 of the head hole 6 are illuminated by a light beam 130 extending linearly. The light beam 130 is a wire harness that extends linearly in parallel with the Z direction. For example, when the laser light source 44 is of the red light type, the red line is projected on the upper surface 5 of the head 4 and the bottom surface 7 of the head hole 6. In Fig. 7(a), a red line 132 projected on the upper surface 5 of the head 4 and a red line 133 projected on the bottom surface 7 of the head hole 6 are shown. The bottom surface of the head hole 6 is not flat, but has a conical shape with an opening angle of 120 degrees. Therefore, the red line 133 projected on the bottom surface 7 has an arc shape.

When the depth of the head hole 6 is inspected by the depth gauge, the depth gauge abuts on the bottom surface 9 of the hexagonal corner portion of the head hole 6. The bottom surface 9 of the hexagonal corner portion of the head hole 6 is different from the conical surface having a flare angle of 120 degrees, that is, the bottom surface 7. Therefore, in order to optically measure the depth of the head hole 6, it is preferable to irradiate the light beam 130 so that the red line projected on the bottom surface of the head hole 6 abuts on the bottom surface 9 of the hexagonal corner portion of the head hole 6. In Fig. 7(a), the red line 133 abuts against the bottom surface 7 which is a conical surface, or does not abut against the bottom surface 9 of the hexagonal corner portion of the head hole 6, and the upper surface 5 of the head 4 is used. The shadow, the end of the red line 133 does not extend to the position of the hexagonal side of the head hole 6.

Fig. 7(b) is a view showing a state in which the workpiece 8 is rotated by Δθ around the axis so that the sides of the hexagon are parallel to the X direction. Here, the red line 134 projected on the upper surface 5 of the head 4 and the red line 135 projected on the bottom surface 7 of the conical surface of the head hole 6 are shown, but the end of the red line 135 extends to the head hole 6 Hexagonal side. However, the red line 135 does not abut against the bottom surface 9 of the hexagonal corner portion of the head hole 6.

Fig. 7(c) is a view showing a state in which the position in the Y direction of the laser light source 44 is shifted by ΔY in the +Y direction with respect to the workpiece 8 with respect to the state of (b). According to the size of ΔY, the light beam moves in the +X direction. In Fig. 7(c), a red line 136 projected on the upper surface 5 of the head 4 and a red line 137 projected on the bottom surface of the head hole 6 are shown. The X-direction position of the red lines 136 and 137 is moved in accordance with the Y-direction movement amount ΔY of the light beam 131. Here, ΔY in a state in which the red line 137 projected on the bottom surface of the head hole 6 abuts against the bottom surface 9 of the hexagonal corner portion of the head hole 6 is shown. Yes The state in which the red line 137 is in contact with the bottom surface 9 of the hexagonal corner portion of the head hole 6 can be determined based on the photographing data of the head portion 4 obtained by the head camera camera 42.

The ΔY system can be arbitrarily set by controlling the actuator 45 that drives the laser light source 44 in the Y direction. When the depth of focus of the head imaging camera 42 is sufficiently deep, the actuator 45 may be omitted, and the position of the laser light source 44 may be set to a position fixed with respect to the Y stage 26, and the Y stage 26 may be provided. Move - △ Y.

In Fig. 7(c), the depth D of the head hole 6 is based on a predetermined inclination angle of the light beam 131 with respect to the Y direction. And the amount of misalignment L of the X position on the XZ plane of the red line 136 and the red line 137 is D = Lcot And calculate. The misalignment amount L is the difference between the X position of the intersection of the hexagonal shape of the head 4 and the red line 136, and the X position of the intersection of the hexagonal shape of the head 4 and the red line 137. In this manner, the measurement of the depth D of the head hole 6 is performed optically and non-contact.

In the case where the head hole 6 is hexagonal, the workpiece 8 is rotated 360 degrees around the axis at an interval of 120 degrees, and the above measurement is repeated. The maximum value, the minimum value, and the average value of these measurement results are taken as the depth measurement values of the head holes 6.

Returning to Fig. 5 again, when the processing of S14 is completed, the measurement by the head imaging camera 42 is completed, so that the piston cylinder mechanism 60 is operated and the X stage 58 is returned to the retracted state. Thereafter, the dimensions of the workpiece 8 in the axial direction and the axis are calculated based on the imaging data of the workpiece 8 acquired by the projection imaging camera 38.

The required shape in the projection shape data of the workpiece 8 taken by the projection camera 38 is the material converted from the white data to the position of the black data. The workpiece 8 is a workpiece in which the male thread portion 2 and the head portion 4 are both cylindrical in the XZ plane or have a helical thread engraved on themselves. Therefore, the position where the projection shape is converted from the white data to the black data is the vertex position where the cylindrical edge portion is an arcuate curved surface. Therefore, it is necessary to align the focus position of the projection imaging camera 38 with the vertex position of the curved surface. In addition, when garbage or the like adheres to the surface of the curved surface, noise is formed in the projected shape data.

The calculation of the focus position of S16 in Fig. 5 and the calculation of the contour data of S18 are performed in advance when various sizes are calculated based on the projection shape data of the workpiece 8 acquired by the projection imaging camera 38.

The focus position calculation (S16) is executed by the function of the focus position calculation unit 114 of the arithmetic control device 100. Specifically, the Z stage 52 of the focus moving unit 50 is moved, and the focus position of the projection imaging camera 38 is moved in the Z direction, and the steepest Z position from the white data to the black data at this time is obtained. And set the position to the focus position. The focus position calculation processing is a so-called auto focus processing, but general auto focus is focused on the surface of the object, and the focus position calculation in S16 is in the edge region where the projection shape data is converted from white data to black data. The position at the time of focusing on the curved surface of the workpiece 8 is calculated.

Fig. 8 is a view showing a method of calculating a focus position. Fig. 8(a) is a view showing a projection state of the outline of the workpiece 8, and Fig. 8(b) is a view showing a black-and-white state of photographing when the focus position of the projection imaging camera 38 is A to E, and (c) is a view by ash. The change of the order value I represents a map of the change of the black and white state, (d) is a graph showing the differential waveform of the gray scale value I with respect to the Z position, and (e) is the half value width ΔZ _0.5 of the waveform representing the (d). A diagram of the relationship at the Z position.

Fig. 8(a) is a view showing the relationship between the light source 36, the projection imaging camera 38, and the workpiece 8 in a plane parallel to the XZ plane. The parallel rays from the light source 36 are blocked by the workpiece 8, and the image area 140 is produced on the downstream side of the workpiece 8. When the image area is captured by the projection camera 38, it becomes black data. The black and white boundary 142 that is converted from white data to black data is represented by a line connecting the curved surface of the workpiece 8. When the projection imaging camera 38 is moved in the ±Z direction with respect to the workpiece 8, the focus position of the projection imaging camera 38 is moved in the ±Z direction corresponding to the movement distance. In Fig. 8(a), the amount of movement of the projection imaging camera 38 in the Z direction is changed into five groups, and the focus positions A, B, C, D, and E on the curved surface of the workpiece 8 at this time are shown.

Fig. 8(b) is a view showing a black-and-white state in the imaging surface captured by the projection imaging camera 38 when the focus position of the projection imaging camera 38 is A to E. In the black-and-white state, the state indicated by the oblique line is a completely black state, and the state represented by the thin point set is a state of incomplete black and incomplete white, and the state in which neither the oblique line nor the fine point set is completely white. When viewed from the light source, the focus position is on the downstream side of the workpiece 8, indicating a state in which the vicinity of the black-and-white boundary 142 is incompletely white and not completely black. When the focus position is on the upstream side of the workpiece 8, the focus is not aligned with the workpiece 8, so that the whole is incompletely white and not completely black.

Figure 8 (c) shows the change of the gray scale value I (b) A diagram of the change in black and white state. The horizontal axis is the Z position, and the vertical axis is the gray level value I. When the focus position is C, the grayscale value I changes abruptly with respect to the change in the Z position, but at other focus positions, the change in the grayscale value I with respect to the Z position is moderated.

Fig. 8(d) is a view showing a differential waveform of the grayscale value I with respect to the Z position in order to clarify the degree of change of the grayscale value I with respect to the Z position. The horizontal axis is the Z position and the vertical axis is dI/dZ. The change of the gray scale value I is represented by a pulse waveform, and the larger the peak value of the pulse waveform is, the smaller the half value width ΔZ _{0.5 of the} pulse waveform is, and the larger the change of the gray scale value I is.

Fig. 8(e) is a view showing the relationship between the half value width ΔZ _0.5 of the waveform of (d) with respect to the Z position. The horizontal axis is the Z position, and the focus positions A, B, C, D, and E of the projection imaging camera 38 are also used for reference. The vertical axis is ΔZ _0.5 . Here, ΔZ _0.5 becomes the minimum value at the focus position C. When the reciprocal of ΔZ _0.5 or the peak of the pulse waveform in (d) is set as the evaluation function of the focus, the projection camera 38 can be calculated by calculating the Z position Z _{0 of the} maximum value by calculating the value of the evaluation function. The focus position. In the case of Fig. 8(e), the Z position when the focus position is C is Z ₀ . The position of the Z stage 52 is fixed in a state where the Z position of the projection imaging camera 38 is at the Z position Z ₀ .

Returning to Fig. 5 again, the processing of the contour data calculation (S18) is executed by the function of the contour data calculation unit 116 of the arithmetic control device 100. Specifically, contour tracking processing is performed on the contour of the projection shape of the workpiece 8 with the black-and-white boundary of the projection shape data of the workpiece 8, and the data of the screw contour distribution is calculated once. Moreover, the distribution of the contour of the screw In the data, the data which is abnormal from the cross-sectional view of the workpiece 8 is used as a smoothing process for noise removal, and the screw contour distribution is calculated twice. The contour of the screw removed by the noise is set to be used later to calculate contour data of various sizes.

Fig. 9 is a view showing a method of removing noise of a contour distribution. Fig. 9(a) is a diagram showing the rules of the contour tracking processing. (b) is the data of the primary screw contour distribution obtained by performing the contour tracking processing on the workpiece 8, and (c) is a graph showing the contour data for removing the noise from (b).

In the contour data calculation, in order to improve the resolution of the contour data, the projection shape data of the workpiece 8 captured by the projection imaging camera 38 is converted into two-dimensional data having a bit map of an arbitrary position resolution. For example, if the pixel resolution in the imaging plane of the projection imaging camera 38 is about 8 μm, one pixel is divided into 8×8 sub-pixels, and the position resolution is changed to a 2-dimensional bitmap of 1 μm. In this way, a two-dimensional bitmap image having sufficient position resolution can be obtained. Hereinafter, the contour tracking processing and the noise removal processing are performed using the data of the two-dimensional bitmap image.

Fig. 9(a) is a diagram showing the rules of the contour tracking processing. The contour tracking processing is processing for tracking the black and white boundary in the two-dimensional bitmap image, and the rule of the contour tracking processing is a rule for determining the order in which the position of the next black data is searched based on the position of one black material. The binarization process that distinguishes the black data from the white data is performed using a predetermined threshold value relative to the grayscale value of the data.

Fig. 9(a) is a diagram showing a well-known rule for contour tracking processing. In this rule, 8 around the location of 1 black data The data position is rotated counterclockwise to determine whether it is black data, and the data position that originally became black data is set to the position of the next black data. The numbers 1 to 8 of Fig. 9(a) indicate that the tracking order of the next black data is searched based on the position of the original black data, and the position from the position of the number 1 to the position of the number 8 is sequentially followed.

Fig. 9(b) is a view showing a rule for converting the projection shape data of the workpiece 8 into two-dimensional bitmap image data, applying the rule of the contour tracking processing of (a), and connecting the black data boundary of the black and white boundary. The bend line 144 represents the trajectory of the tracking process. The data position marked with a slash is the black data position of the black and white border, and the line connecting the position is a screw contour distribution.

Initially, the presence or absence of scanning black data is searched from the upper left position of the two-dimensional bitmap to the right. Here, the initial black data is detected by scanning from the top to the second line. This position is set to the position 145 of the original black material. Among the eight material positions around the position 145 of the black material, the position to be the next black material is searched according to the rule of (a). In the example of (b), the data position obliquely below is observed from the position 145 of the black data, and the fourth data position in the order of tracking indicated in (a) is the position of the next black data. This search is repeated, and the contour tracking ends when the end of the 2-dimensional bitmap is reached.

In Fig. 9(b), at positions 146, 148, and 150 of the black material, the bending line 144 which is the trajectory of the tracking process returns. In the outline shape of the workpiece 8, even if the male thread portion 2 is smoothly changed, the positions 146, 148, and 150 of the three black materials are highly likely due to the presence of garbage or the like, and the screw is high. Observed the shape of the section, judged as abnormal.

(c) of FIG. 9 is a smoothing process for removing the positions 146, 148, and 150 of the three pieces of black data determined to be abnormal from the cross-sectional shape of the screw, and generating the secondary screw as the normal shape of the workpiece 8 as normal. A map of the contour distribution. The bend line 152 does not return and becomes a track of monotonous change. Here, as the noise determination criterion, the presence or absence of the return in the bending line 144 indicating the trajectory of the contour tracking is used. It is also possible to replace the return presence with the degree of change in the direction of the bend line 144 as a noise determination criterion. In addition, the actual tracking trajectory can be normalized by the tracking trajectory of the workpiece 8 which is regarded as a normal contour shape, and the difference between the tracking trajectory which is regarded as a normal contour shape and the tracking trajectory of the actual contour shape can be used. When it exceeds the predetermined threshold range, it is set as the noise judgment criterion for noise.

In this way, smoothing processing for removing noise can be performed by applying a preset noise determination reference to the contour distribution data obtained by the known contour tracking processing, and contour data indicating the screw contour distribution of the workpiece 8 can be calculated.

When the processes of S16 and S18 are completed, the projection shape data of the workpiece 8 acquired by the projection imaging camera 38 is used, and various dimensional measurements are performed. Since the workpiece 8 has a shape extending in the Y direction, it is effective to sequentially measure the size of the workpiece 8 while lowering the projection imaging camera 38 from the initial Y position toward the -Y direction. Therefore, after the head size measurement (S12) and the head hole depth measurement (S14), the height measurement of the head portion 4 is performed based on the projection shape data acquired by the projection imaging camera 38. This measurement is performed as a part of the full length calculation (S26) which will be described later. Specifically, as shown in Fig. 6, the Y position Y ₁₀ of the upper surface of the head portion 4 and the Y position Y _{9 of the} lower surface are measured.

Here, in order to cause the outline data indicating the upper surface of the head portion 4 to enter the imaging surface of the projection imaging camera 38, the operation of the Y motor 29 is controlled, and the data value of Y ₁₀ is obtained by the sensor 30. Next, while rotating the workpiece 8 by 360 degrees around the axis at an interval of 1 degree, the Y direction of the contour data of the upper surface of the head 4 acquired by the projection imaging camera 38 is obtained on the two-dimensional bitmap image for each angle. The position, for example, is a precision value of Y ₁₀ calculated in units of 1 μm. For the precision value of Y ₁₀ calculated for each angle, the maximum value, the minimum value, and the average value are obtained, and these values are added to the data value from the sensor 30 to be the maximum value, the minimum value, and the average value of Y ₁₀ . .

Similarly, the data from the sensor 30 is also obtained for the lower surface of the head 4, and then the workpiece 8 is obtained by rotating the workpiece 8 around the axis at an interval of 1 degree, and the projection camera 38 is obtained on the 2-dimensional bitmap. The position of the obtained contour data of the lower surface of the head 4 in the Y direction is calculated, for example, by a precision value of Y ₉ in units of 1 μm. For the precision value of Y ₉ calculated for each angle, the maximum value, the minimum value, and the average value are obtained, and these values are added to the data value from the sensor 30, and the maximum value, the minimum value, and the average value of Y ₉ are set. value.

When the measurement of the height dimension of the head 4 is completed, the Y stage 26 is further lowered in the Y direction, and the head-down R measurement is performed (S20). The under head R is the radius of curvature of the lower portion of the head between the head 4 and the male thread portion 2. This processing is executed by the function of the head-down R calculation unit 118 of the arithmetic control device 100. Specifically, using the method illustrated in Figure 9 in the 2-dimensional position The contour data of the head lower portion 3 of the workpiece 8 obtained by the projection camera 38 is obtained on the meta map. This outline data indicates the lower portion 3 of the workpiece 8 as S20 in Fig. 6 . An angle dividing line that divides the angle formed by the two straight lines on both sides of the R portion of the contour data into two is obtained, and the length of the perpendicular line from the line to the nearest two straight lines is calculated as the head-down R.

Fig. 10 is a view showing a method of calculating the head R. Fig. 10(a) is a view showing outline data 160 on a two-dimensional bitmap of the lower portion 3 of the workpiece 8. Fig. 10(b) is a view showing the two straight lines 162 and 163 of the outline data 160 of the configuration (a), and the angle dividing line 164 for equally dividing the angle formed by the two straight lines 162 and 163 is obtained. From this angle, the dividing line 164 is suspended to the vertical lines 166, 167 of the straight lines 162, 163.

The value of the head R is calculated from the length of the vertical lines 166 and 167. That is, the workpiece 8 is rotated 360 degrees around the axis at an interval of 1 degree, and the lengths of the vertical lines 166, 167 are obtained for each angle. For 360 degrees, the interval is obtained at 1 degree interval, so the total length value of the vertical line is 720. For the obtained value, the maximum value, the minimum value, and the average value are set to the value of R below the head.

Returning to Fig. 5 again, after S20, the top diameter measurement (S22) and the bottom diameter measurement (S24) are performed. The top diameter is the outer diameter of the thread top, and the bottom diameter is the inner diameter of the thread bottom. This processing is executed by the function of the screw diameter calculating unit 110 of the arithmetic control device 100. The top diameter measurement (S22) and the bottom diameter measurement (S24) are performed on a plurality of portions along the axial direction of the male screw portion 2 of the workpiece 8. In Fig. 6, the Y positions Y ₈ , Y ₇ , and Y ₆ of the three portions of the top diameter measurement (S22) and the bottom diameter measurement (S24) are referred to as S22 and S24, and are shown. The number of measurement sites can be appropriately determined depending on the length of the male screw portion 2 of the workpiece 8.

Fig. 11 is a view showing a method of measuring the top diameter. Fig. 11 (a) and (c) are diagrams showing outline data of the male screw portion 2 of the workpiece 8 on the two-dimensional pixel map, and Fig. 11 (b) is a partial enlarged view of (a).

In Fig. 11(a), two outline data 170, 171 of the male screw portion 2 of the workpiece 8 are shown. The two contour data 170 and 171 are data indicating the outline shapes of the left and right sides of the male screw portion 2 of the workpiece 8. (b) is a partial enlarged view of (a), and shows a method of obtaining the regression line 172 at the top of the contour data 170 using the map. The regression line 172 at the top is a straight line passing through the average position of the plurality of top vertices of the male thread portion 2.

When the regression line 172 is obtained, the entire outline data 170 is found to be at the top apex on the outer diameter side of the regression line 172. This is to find the line 173 perpendicular to the regression line 172 and to move the position of the regression line 172 in the direction in which the vertical line 173 extends. Then, the maximum value a of the amount of movement of the regression line 172 connected to at least one top vertex in the contour data 170 is obtained. The amount of movement is measured along line 173 that is perpendicular to the regression line 172. a is a value indicating a position at the top apex on the outermost diameter side of the contour data 170 as viewed from the regression line 172.

Next, as shown in Fig. 11(c), the regression line 172 is moved toward the contour data 171 along the line 173 perpendicular thereto, and the amount of movement of the regression line 172 connected to the plurality of top vertices in the contour data 171 is obtained. The maximum value b. b is a value indicating a position of the top vertex located on the outermost diameter side of the contour data 171 as viewed from the regression line 172. The top diameter is the top outer diameter in the male thread portion 2 of the workpiece 8, so (a+b) corresponds to the workpiece 8 The top diameter value of the two contour data 170, 171 of the male thread portion 2.

Here, the workpiece 8 is rotated 360 degrees around the axis at an interval of 1 degree, and (a+b) of the two contour data of each angle is obtained. When 360 (a+b) values are obtained, the maximum value, the minimum value, and the average value are set as the measured values of the top diameter of the measurement site. As shown in Fig. 6, the top diameters were calculated for each of the three measurement sites. The positions of the three measurement sites are set so as to substantially cover the entire area of the entire length of the male screw portion 2 of the workpiece 8. The number of measurement sites may be other than three. For example, it may be four or more, or two or less.

Fig. 12 is a view showing a method of measuring the bottom diameter. Similarly to Fig. 11, Fig. 12 (a) and (c) are diagrams showing outline data of the male screw portion 2 of the workpiece 8 on the two-dimensional pixel map, and (b) is a partial enlarged view of (a). In Fig. 12(a), two contour data 170, 171 are shown as in Fig. 11. The bottom measurement is similar to the top measurement except that the regression line 176 shown in Fig. 12(b) is a straight line passing through the average position of the plurality of bottom bottom points of the male screw portion 2.

When the regression line 176 is obtained for the bottom portion, as shown in Fig. 12(b), the entire outline data 170 is located at a position closer to the bottom bottom point on the inner diameter side than the regression line 176. A line 177 perpendicular to the regression line 176 is found and moved in a direction in which the vertical line 177 extends in the position of the regression line 176. Then, the maximum value c of the amount of movement of the regression line 176 connected to at least one bottom bottom point in the contour data 170 is obtained. The amount of movement is measured along line 177 that is perpendicular to the regression line 176. c is a view showing the bottom of the innermost diameter side of the contour data 170 as viewed from the regression line 176. The value of the position of the bottom point.

Next, as shown in Fig. 12(c), the regression line 176 is moved toward the contour data 171 along the line 177 perpendicular thereto, and the regression line 176 connected to at least one bottom bottom point in the contour data 171 is obtained. The maximum value d of the amount of movement. d is a value indicating a position at the bottom bottom point on the most inner diameter side of the contour data 171 as viewed from the regression line 176. The bottom diameter is the minimum inner diameter of the bottom of the workpiece 8, so (d-c) corresponds to the bottom diameter values of the two contour data 170, 171 of the male screw portion 2 of the workpiece 8.

Here, the workpiece 8 is rotated 360 degrees around the axis at an interval of 1 degree, and (d-c) of the two contour data of each angle is obtained. When 360 (d-c) values are obtained, the maximum value, the minimum value, and the average value are used as the measured values of the bottom diameter of the measurement site. The bottom diameter measurement and the top diameter measurement system are performed in pairs, and the measurement site of the bottom diameter is the same as the measurement site of the top diameter.

When the measured value of the top diameter and the measured value of the bottom diameter are calculated, the effective diameter = (top diameter + bottom diameter) / 2 is calculated. For the effective diameter, the maximum value, the minimum value, and the average value are also calculated. The maximum value is calculated based on the maximum value of the top diameter and the minimum value of the bottom diameter. The minimum value is calculated from the minimum value of the top diameter and the maximum value of the bottom diameter. The average value is based on the average of the top diameter and the average of the bottom diameter. Calculated by value. Various calculations related to the effective diameter may be performed using other calculation methods.

When the measurement of S22 and S24 is completed, the Y stage 26 is further lowered, and the Y position Y ₁ of the upper surface of the ring gauge 82a of the adapter 80 that grips the distal end portion of the male screw portion 2 of the workpiece 8 is measured. Specifically, it can be performed in the same order as the measurement of the Y position Y ₁₀ of the upper surface of the head 4 and the Y position Y ₉ of the lower surface. That is, in order to make data representing the contour of the upper surface of the ring gauge enters the imaging plane of the projection 82a of the imaging camera 38, and the control operation of the motor 29 of the Y, and using the sensor 30 to obtain data values of Y _1. Next, while rotating the workpiece 8 by 360 degrees around the axis at an interval of 1 degree, the position in the Y direction of the contour data of the upper surface of the ring gauge 82a obtained by the projection imaging camera 38 is obtained on the two-dimensional bitmap image, for example. The precision value of Y ₁ was calculated in units of 1 μm. For the calculated precision value per degree Y ₁ , the maximum value, the minimum value, and the average value are obtained, and these values are added to the data values from the sensor 30 to be the maximum value, the minimum value, and the average value of Y ₁ . .

Returning to Fig. 5 again, the full length calculation is performed (S26). This processing is executed by the function of the total length calculating unit 112 of the arithmetic control device 100. Specifically, based on the values of the Y positions Y ₁₀ , Y ₉ , and Y ₁ that have been measured, and the predetermined engagement lengths of the reference female threads 83a of the ring gauge 82a and the front end portion of the male screw portion 2 of the workpiece 8, that is, three The length of the pitch was 5.25 mm, and the total length of the workpiece 8 was calculated. The total length of the male screw portion 2 is calculated as {(Y ₉ -Y ₁ )+5.25 mm}. The entire length of the workpiece 8 including the head 4 is calculated as {(Y ₁₀ -Y ₁ )+5.25 mm}. In the full-length calculation, the maximum value, the minimum value, and the average value of the full length are calculated from the maximum value, the minimum value, and the average value of each of Y ₁₀ , Y ₉ , and Y ₁ . For example, the maximum value of the total length of the male screw portion 2 is calculated based on the maximum value of Y ₉ and the minimum value of Y ₁ , and the average value of the total length of the male screw portion 2 is based on the average value of Y _{9 and} the average value of Y ₁ . Calculated. Various calculations related to the full length may be performed using other calculation methods.

When the full length calculation (S26) is completed, each of the workpieces 8 is performed. The measurement data of the size is output (S28). This processing is executed by the function of the measurement data output unit 124 of the arithmetic control device 100. Specifically, the size of the head is measured by S12, the head hole depth measurement of S14, the head R measurement of S20, the measurement of the top diameter of S22, the measurement of the bottom diameter of S24, and the calculation of the total length of S26. The maximum value, the minimum value, the average value, and the like are recorded in a predetermined recording position in accordance with a predetermined check list format, and are printed as an inspection table 106 from the output device 104.

As described above, according to the screw size automatic measurement system 10, various sizes related to the screw can be automatically measured, and the measurement result can be automatically output as a checklist of a predetermined format.

In the above, the measurement of the depth of the head hole is performed optically and non-contact. Instead, it is a contact type, but the head hole depth for screw inspection can be used to measure the depth of the head hole. Fig. 13 is a view showing a method of inserting the head hole drill bit 180 into the head hole 6 of the workpiece 8 in the workpiece 8, and capturing the state by the projection imaging camera 38, and calculating the head hole depth D based on the obtained projection shape data. Figure. Fig. 13 (a) is a cross-sectional view, and (b) is a plan view.

The head hole drill bit 180 for screw inspection is configured to include a head hole fitting portion 182, a flange portion 184 having a disk shape, a holding cylindrical portion 186, and a conical top portion 188. In order to insert the head hole drill bit 180 into the head hole 6 of the workpiece 8, the gripping flange portion 184 and the holding cylindrical portion 186 can be conveyed to the head by using a two-division chuck or the like. Above the hole 6, the holding of the two-division chuck or the like is released, and the head hole drill bit 180 is dropped. At the head hole of the workpiece 8 with the head hole drill bit 180 When it is dropped, it is preferable to press it from the upper side to the lower side of the conical top 188. The gripping and releasing of the head hole drill bit 180 of the two-division chuck and the press-fitting of the conical top portion 188 can be automatically performed using a piston-cylinder mechanism or the like that operates by the air pressure supplied from the air pressure control device 102.

The height dimension G and shape of the head hole fitting portion 182 of the head hole drill bit 180 can be changed depending on the type of the workpiece 8. The size and shape of the other flange portion 184, the holding cylindrical portion 186, and the conical top portion 188 can be made the same regardless of the type of the workpiece 8.

When the head hole drill bit 180 is inserted into the head hole 6 of the workpiece 8, the projection camera 38 performs imaging, and based on the contour data, the upper surface of the head of the workpiece 8 and the flange of the head hole drill bit 180 can be calculated. The spacing dimension Y ₂ along the Y direction between the lower surfaces of the portions 184. Calculated based on the size of the interval and height dimension Y ₂ G bit head bore head portion 180 of the fitting hole 182, as the head bore depth dimension D = (GY ₂₎ is calculated.

Fig. 14 is a view showing a head hole drill which differs depending on the type of the workpiece 8. Here, the head hole drill corresponding to the type of the three workpieces 8 is shown, and the head hole drills of the different types of workpieces 8 other than the above may have the same structure. In Fig. 14(a), in the case where the thread of the workpiece 8 is nominally M12, it is the same as the head hole drill 180 described in Fig. 13.

Fig. 14(b) is a view showing the head hole drill bit 180b when the thread of the workpiece 8 is nominally M6. The flange portion 184, the holding cylindrical portion 186, and the conical top portion 188 are the same as (a). Shape of the head hole fitting portion 182b The shape and size are different from (a). Fig. 4(c) is a view showing the head hole drill bit 180c when the thread of the workpiece 8 is nominally M3. The flange portion 184, the holding cylindrical portion 186, and the conical top portion 188 are the same as (a) and (b). The shape and size of the head hole fitting portion 182c are different from those of (a) and (b).

By combining the shape and the size of the elements other than the head hole fitting portion 182, the two-division card for holding the head hole drills 180, 180b, and 180c can be used in common regardless of the type of the workpiece 8. Disk and so on.

Fig. 15 is a front elevational view showing the main part of the automatic screw size measuring device 12a constituting the automatic screw size measuring system of another example of the embodiment. Fig. 16 is a right side view of the automatic screw size measuring device 12a of Fig. 15. Fig. 17 (a) is a plan view of the screw size automatic measuring device 12a, and shows a state in which the head imaging camera 42 is retracted to the right side, and Fig. 17 (b) shows that the head imaging camera 42 is moved to the imaging. Top view of the state of the location. Fig. 18 is a view in which the head imaging camera 42 is omitted in a plan view of the screw size automatic measuring device 12a.

In another automatic screw size measuring system of the other example, the basic configuration of the vibration isolating table 14, the frame 15, the base 16, the arithmetic control device 100, the air pressure control device 102, and the output device 104 (see Fig. 1) The configurations shown in Fig. 1 to Fig. 12 are the same. Another example of the automatic screw size measuring device 12a constituting the automatic screw size measuring system is a gantry type. Specifically, on the upper surface plate 16a of the upper surface of the base 16 on which the screw size automatic measuring device 12a is formed, a column member 190 having a quadrangular prism shape is erected and fixed. The column member 190 is as shown in Fig. 17, viewed from the Y direction The shape of the inspection is roughly rectangular. A lifting actuator 192 is attached to the front surface of the column member 190 (the front side surface of Fig. 15, the left side surface of Fig. 16, and the lower side surface of Fig. 17(a)).

The lift actuator 192 includes an actuator case 194 fixed to the front surface (+X direction side) of the column member 190, a screw shaft (not shown), a Y motor 29a, and a nut member (not shown). The actuator case 194 is elongated in the vertical direction, that is, in the Y direction. A housing of the Y motor 29a is fixed to the upper surface of the actuator housing 194, and an output shaft extending downward (-Y direction) from the Y motor 29a is threaded in the actuator housing 194 along - The Y-direction extends and is rotatably supported by the actuator housing 194. Thereby, the threaded shaft is rotated by the rotation of the Y motor 29a. The drive of the Y motor 29a is controlled by the arithmetic control device 100 (Fig. 1). On the -X side of the column member 190 (the back side of Fig. 15, the left side of Fig. 16, and the upper side of Fig. 17 (a)), the bit clamping unit 210, which will be described later, is supported so as to be movable in the Y direction. Lifting member 212.

In the Z-direction end portions on the front side (+X side) of the actuator casing 194, two parallel guide holes 195 are formed substantially in the Y direction over the entire length. Further, the Y table 196 is movably supported on the actuator housing 194 in the Y direction. The Y table 196 is a substantially flat moving table along the YZ plane. For ease of understanding in Fig. 15, the Y table 196 is shown in sand.

The nut member in the actuator housing 194 is engaged with the threaded portion of the threaded shaft via a plurality of balls to constitute a ball screw mechanism. Two parallel sliding legs are formed at both ends of the nut member in the Z direction 198 (Fig. 17 (a)). Each of the sliding leg portions 198 protrudes outward from the actuator housing 194 by a guide hole 195. Further, a Y table 196 is fixed to the front end portion of each of the sliding leg portions 198. Thereby, the Y table 196 can be moved in the Y direction by the rotation of the Y motor 29a. The lift actuator 192 constitutes an axial movement portion that moves the Y table 196 in the Y direction with respect to the base 16 .

Further, as shown in Fig. 16, a linear scale type position sensor 200 is attached to the +Z side end portion of the actuator casing 194. That is, the position sensor 200 detects the Y-direction position of the Y table 196. The position sensor 200 is only required to detect the Y-direction position of the moving member 202 attached to, for example, the Y table 196 optically or magnetically and with high precision. For example, in the magnetic position sensor 200, the exciting coil and the detecting coil through which the current flows are attached to the moving member 202, and are fixed at a plurality of positions in the Y direction of the fixed side member 204 fixed to the actuator housing 194. Side coil (not shown). In the case where the moving member 202 is moved in the Y direction, the exciting coil and the detecting coil of the moving member 202 are close to and opposed to one of the plurality of fixed-side coils, and the moving member is detected based on the voltage change at both ends of the detecting coil. 202 location. A signal indicating the detection position of the moving member 202 is transmitted to the arithmetic and control device 100 (Fig. 1).

The optical measuring device 32a is supported on the front (+X direction) side of the Y table 196. The optical measuring device 32a is configured to include an image projecting unit 34a and a head measuring unit 40a. The image projecting unit 34a has a lower fixed table 230 that is fixed to the front side of the Y table 196 and that is long in the Z direction, and a light source that is fixed to the -Z side end of the lower fixed table 230. 36. A projection imaging camera 38 supported by the +Z side end of the lower fixed table 230.

The Z moving table 232 is movably supported by the lower fixed table 230 in the Z direction. The Z moving table 232 is moved in the Z direction by the linear actuator 234 with respect to the lower fixed table 230. The linear actuator 234 includes an electric motor and a ball screw mechanism, and the nut member that meshes with the threaded shaft of the ball screw mechanism via the ball is moved in the Z direction by the rotation of the electric motor. The Z moving table 232 is fixed to the nut member, and the Z moving operation also moves in the Z direction by the movement of the nut member in the Z direction. The electric motor is controlled by the arithmetic control device 100. Thereby, the projection imaging camera 38 moves in the +Z direction or the -Z direction by the rotation of the electric motor. The focus moving unit 50 is constituted by the linear actuator 234 and the Z moving table 232. The projection imaging camera 38 and the light source 36 hold the workpiece 8 as a screw to be imaged, and are opposed to each other in the Z direction. As the electric motor constituting the linear actuator, an AC servo motor or a stepping motor can be used.

The workpiece 8 is screwed into the ring gauge 82c of the adapter 80 in the same manner as the first to the thirteenth drawings, and the adapter 80 is held by the fastening chuck 70. The support base 72 of the fastening chuck 70 is fixed to the upper side of the rotating member 236 that extends in the vertical direction with respect to the base 16 .

The lower end of the rotating member 236 is rotatably supported around the Y-axis to a rotary joint 238 fixed to the base 16. A pulley 244 is attached to the pulley 240 fixed to the intermediate portion of the rotating member 236 in the Y direction and the pulley 242 fixed to the output shaft of the θ motor 64. The θ motor 64 is attached to the base. The lower side of the upper surface plate 16a of 16 is offset from the +Z direction (the right side in Fig. 15). Thereby, the rotation member 236 is rotated via the belt 244 by the rotation of the θ motor 64, and the fastening chuck 70 is rotated about the Y-axis together with the workpiece 8. As long as the support base 72 can be rotated, it can be configured arbitrarily.

The projection imaging camera 38 receives the parallel light from the light source 36 and causes the projection shape of the image to be the workpiece 8 to be imaged on the imaging surface parallel to the XY plane.

The head measuring unit 40a disposed above the workpiece 8 has an upper fixed table 250 that is fixed to the upper side of the lower fixed table 230 on the front side (+X side) of the Y table 196, and is attached to the upper fixed table. The head camera moving unit 252 on the front side of the 250 and the head imaging camera 42 are provided. The head camera moving unit 252 has a rod portion 254 to which the head imaging camera 42 is fixed at the distal end portion, and a piston cylinder mechanism 256 that expands and contracts the rod portion 254 in the Z direction. The piston cylinder mechanism 256 is controlled by the arithmetic control device 100 (Fig. 1), and the piston is reciprocated in the Z direction by the air pressure supplied from the air pressure control device 102 (Fig. 1). A rod portion 254 is fixed to the piston, and the head camera camera 42 is also moved in the -Z direction by the piston moving in the -Z direction, and the head camera camera 42 is also moved in the +Z direction by the piston moving in the +Z direction. . Thereby, the head imaging camera 42 can be retracted from the position P of the workpiece 8 in the XZ plane toward the +Z direction as shown in Fig. 17 (a), as shown in Fig. 17 (b). The position directly above the position P moves between the two positions.

The head imaging camera 42 acquires imaging data of the shape of the head of the workpiece 8 in the same manner as the configuration shown in FIGS. 1 to 12, and The diameter of the head, the size of the opposite side of the head hole 6 (see Fig. 3), and the like are calculated. Unlike the configurations of Figs. 1 to 12, the head measuring unit 40a does not include a laser light source for measuring the head hole depth of the workpiece 8, and does not include an actuator for moving the laser light source. Instead, the screw size automatic measuring device 12a includes a bit clamping unit 210 that clamps the head hole drill bit 180 (Fig. 19) and moves it.

Fig. 19 is a view showing the bit clamping unit 210 in the left side view of Fig. 15. As shown in Fig. 15, Fig. 17, and Fig. 19, the bit clamping unit 210 is attached to the -Z side of the column member 190 (the left side of Fig. 15, Fig. 17 (a), and the front side of Fig. 19). And a guide member 214 and a lifting member 212 that are long in the Y direction. The illustration of the column member 190 and the lift actuator 192 is omitted in Fig. 19.

The elevating member 212 is movably supported on the -Z side of the guide member 214 in the Y direction. A telescopic arm 216 that is expandable and contractible in the X direction is attached to the lifting member 212. The telescopic arm 216 is telescoped by a piston cylinder mechanism 218. The air pressure supplied to the piston cylinder mechanism 218 is controlled by the air pressure control device 102 (Fig. 1). A drill grip portion 220 is attached to the front end portion of the telescopic arm 216 so as to face the upper surface of the workpiece 8. The drill grip portion 220 is a two-division chuck having two claw portions 221 at the lower end portion. The two claw portions 221 are operated by the air pressure supplied from the air pressure control device 102, and are moved in the radial direction of the drill grip portion 220. The two claw portions 221 have a function of gripping the head hole drill bit 180 (Fig. 19) for measuring the head hole depth of the workpiece 8; and releasing the grip of the head hole drill bit 180 above the workpiece 8, thereby making the head Hole drill bit 180 to the head The function of the hole 6 (refer to Fig. 3) is dropped.

As shown in Fig. 19, the elevating member 212 is fixed to the front end portion of the upper and lower rods 222 supported on the base 16. The upper and lower rods 222 are disposed along the Y direction and are displaced in the Y direction by the piston cylinder mechanism 224. Piston cylinder mechanism 224 is controlled by air pressure control device 102. Thereby, the air pressure control device 102 controls the air pressure supplied to the respective piston-cylinder mechanisms 218, 224 and the bit grip portion 220 of the bit clamping unit 210, whereby the bit grip portion 220 can be clamped to the head at a predetermined position. The hole drill bit 180 is moved to a predetermined position in the X direction and the Y direction, and the head hole drill bit 180 is placed above the workpiece 8 to fall to the head hole 6.

The bit clamping unit 210 may be configured such that a laser light source is attached to the front end portion of the telescopic arm 216 as a laser irradiation unit, and the laser light source is obliquely upward from the head of the workpiece 8 toward the head. The part is illuminated by a laser. Therefore, the drill gripping portion 220 of the drill bit clamping unit 210 is preferably configured to be exchangeable with a laser irradiation member including a laser light source.

According to the above configuration, the projection imaging camera 38 can be moved to a desired position in the Y direction and the Z direction, and the head imaging camera 42 can be moved to a desired position in the Y direction and the Z direction. Further, by attaching the workpiece 8 as a screw to the grip portion 68 including the adapter 80 and the fastening chuck 70, the axial direction of the workpiece 8 and various dimensions around the shaft can be automatically measured. In the same manner as the processing of S18 in the fifth embodiment, the contour data calculation unit 116 of the calculation control device 100 calculates the contour data, and when measuring the height dimension of the workpiece 8, the contour data of the camera camera 38 according to the projection can be obtained. The calculated Y-direction position, for example, the maximum value, the minimum value, and the average value of Y ₁₀ plus the high-precision detection data of the position sensor 200. Thereby, the height direction dimension of the workpiece 8 can be measured with higher precision. Other configurations and operations are the same as those shown in Figs. 1 to 12 described above.

On the other hand, in the configuration of Figs. 1 to 12 or the configuration of Figs. 15 to 19, when the dimensions of the workpiece 8 around the Y axis, for example, the top diameter and the bottom diameter, are measured, as described below. It is also possible to carry out measurement with higher precision in consideration of adhesion of foreign matter. Fig. 20 is a view showing a method of calculating the top diameter at a predetermined angle after calculating the contour data in the automatic screw size measuring system according to another example of the embodiment of the present invention, and is an enlarged view of Fig. 12(c). Fig. 21(a) is a view showing measurement data of a top diameter dmax and a bottom diameter dmin of a predetermined angle by a curve and expressed by a relationship with an angle θ, and Fig. 21(b) is a workpiece 8 as a screw. A partial cutaway view of the axial direction. Fig. 22 is a view showing an ideal model (a) in the relationship between the measurement data of the top diameter d max of the predetermined angle and the number of measurement data, and the case (b) in which the measurement data of the predetermined range is excluded in one example. Figure.

As shown in Fig. 20, when the top diameter d max and the bottom diameter d min of the workpiece 8 are obtained, after the two contour data 170 and 171 of the workpiece 8 are calculated at a certain angle around the Y axis of the workpiece 8, as described above As described in the configuration of Fig. 12 to Fig. 12, the top diameter d max and the bottom diameter d min of the workpiece 8 are calculated at a plurality of positions in the Y direction of the male screw portion 2 of the workpiece 8 . At this time, as described above, the top diameter d max (= a + b) of the contour data 170, 171 is obtained from the regression lines 172, 174 connected to the vertices of the tops of the two contour data 170, 171. Further, the measured value of the top diameter d max is obtained at intervals of every 1 degree, for example, at predetermined angular intervals around the Y axis of the workpiece 8. Similarly, the measured value of the bottom diameter dmin is obtained from the regression line connected to the bottom point of the bottom of the contour data 170, 171.

At this time, for the top diameter d max and the bottom diameter d min , when the maximum value, the minimum value, and the average value are respectively determined from the entire group of measurement data of the respective angles at predetermined angular intervals, the workpiece 8 is attached. In the case of foreign matter, a large error may occur. Specifically, as shown in FIG. 21( b ), foreign matter 11 such as dust or dust may adhere to the male screw portion 2 of the workpiece 8 . In Fig. 21(a), the vertical axis represents the top diameter d max and the bottom diameter d min , and the horizontal axis represents the rotation angle θ of the workpiece 8 around the Y axis at the time of measurement. At this time, the average value da, db of the total measurement data of each of the top diameter d max and the bottom diameter d min is largely deviated from the portion indicated by the one-dot chain lines Q1 and Q2 in accordance with the adhesion of the foreign matter 11 described above. An error has occurred. Further, when the same calculation processing is repeated several times to obtain the top diameter d max and the bottom diameter d min , the error of the measurement data of a part of the angle θ may be increased, and the calculated value finally obtained may be largely deviated correctly. Value. In this case, the top surface d max and the bottom diameter d min are subjected to the filtering process of the lower surface, and the top diameter d max and the bottom diameter d min are obtained instead of the entire group of the measurement data at intervals of every predetermined angle. Maximum, minimum, and average. In the filtration process, a part of the data is excluded from the group of measurement data, and the maximum value, the minimum value, and the average value of the top diameter d max and the bottom diameter d min are calculated.

In the filtering process, first, the distribution of the measurement data of the ideal model in which the foreign matter 11 is not attached to the male screw portion 2 of the workpiece 8 is considered. In this case, as shown in Fig. 22(a), when the top diameter d max is represented by the horizontal axis and the number of measurement data is indicated by the vertical axis, the measurement data of the top diameter d max is Is a normal distribution. The "ideal model" can be set in advance according to the design size of the screw to be measured. On the other hand, in one example in which the foreign thread is attached to the male screw portion 2 of the workpiece 8, the measurement data is distributed as shown in Fig. 22(b). Specifically, in Fig. 22(b), due to the presence of foreign matter, as indicated by the solid line α, the average value da1 and the mode db1 are deviated from the average value da of the ideal model indicated by the broken line β toward the positive side. The mode of the ideal model is the same as the mean da.

Further, as the filtering process, the arithmetic and control device 100 measures the top diameter d max of the workpiece 8 from the contour data of the workpiece 8 at predetermined angles, based on the average value da of the measurement data of the predetermined ideal model. A part of the measurement data excluding the top diameter d max in the data set. Further, the value of the top diameter d max , for example, the maximum value, is calculated from the remaining group of the measurement data of the top diameter d max .

Specifically, in the filtering process, the lower limit threshold value for excluding a part of the data, that is, the lower limit threshold value and the upper limit threshold value as the upper limit threshold value are based on the average value da of the respective ideal models, and as a standard The range in which the deviation σ is proportional is set. In this case, as an arbitrary proportional constant that can change K, the values from the average value d of the ideal model to the upper side and the upper side are set to the lower limit critical value (da-K σ) and the upper limit critical value (da+). K σ). For example, K is set to an arbitrary number such as 1.0 or 1.2 or 0.7. Further, as shown in Fig. 22(b), in the curve of the measurement data of the top diameter d max indicated by the solid line α, the exclusion from the lower limit critical value (da-K σ) to the upper limit critical value (da+K) is excluded. Measurement data of the range of σ) (hatched portion of Fig. 22(b)). Moreover, the top diameter d max is calculated based on the remaining groups of the measured data. The value of, for example, the maximum value, the minimum value, and the average value of the top diameter d max . For the bottom diameter d min , the upper limit critical value and the lower limit critical value are set as well as the top diameter d max , and the measurement data deviating from the lower limit critical value to the upper limit critical value is excluded, and the value of the bottom diameter d min is calculated, for example, the bottom The maximum, minimum, and average values of the diameter. Further, the arithmetic and control unit 100 outputs the values calculated for the top diameter d max and the bottom diameter d min in the output device 104 (see FIG. 1).

According to the above configuration, the value of the dimension of the workpiece 8 around the Y axis can be calculated with higher precision. For example, as shown by the hatched portion in Fig. 22(b), the measurement data lower than the lower limit threshold value and the measurement data exceeding the upper limit critical value are excluded from the top diameter d max , so that the influence of the foreign matter 11 can be reduced, and the effect is closer. The maximum, minimum, and average values of the correct values of the top diameter d max . In addition, in the above, the magnitude of the average value da to the lower limit critical value and the magnitude of the average value da to the upper limit critical value are set to the same value K σ , but the respective sizes may be different. For example, the proportional constant may be set to two different values K1 and K2, the lower limit critical value may be set to (da-K1 σ), and the upper limit critical value may be set to (da+K2 σ). At this time, the proportional constant K2 of the upper limit critical value may be made smaller than the proportional constant K1 σ of the lower limit critical value. Further, the standard deviation σ may not be used in the setting of the upper limit threshold value and the lower limit threshold value, and the upper limit threshold value and the lower limit threshold value may be set to arbitrary values that are set in advance according to the design size of the workpiece 8.

Further, in the example shown in the ninth embodiment, the contour tracking processing of the workpiece 8 is performed, and the data determined to be abnormal is removed from the data of the two-dimensional bitmap image, and the smoothing processing is performed to generate the screw contour. Distribution situation. On the other hand, in the primary screw profile distribution of the two-dimensional bitmap, the smoothing process can be performed by low-pass filtering, and the screw contour distribution can be generated twice.

Fig. 23 is a view showing the primary screw contour distribution (a) of the workpiece 8 and the secondary screw contour distribution (b) after the filtering process in the case where the contour data of the predetermined angle of the workpiece 8 is low-pass filtered. The primary screw profile distribution is a trajectory of the measured data continuously along the axial direction of the workpiece 8.

In Fig. 23, in one screw contour distribution, abnormal portions and noise removal due to adhesion of foreign matter are performed by low-pass filtering. Specifically, the arithmetic and control unit 100 obtains contour data based on the black data of the boundary of the black and white binarization shown in FIG. The calculation control device 100 sets the trajectory of the measurement data continuous in the Y direction of the workpiece 8 to the primary screw contour distribution in the contour data of every predetermined angular interval obtained when the workpiece 8 is rotated about the Y axis. Further, smoothing processing is performed by performing low-pass filtering of a predetermined predetermined frequency on the screw contour distribution, and the contour data of the workpiece 8 at predetermined angular intervals, that is, the secondary screw contour distribution is obtained. Thereby, the arithmetic and control device 100 performs the removal of the abnormal portion and the noise in the screw contour distribution.

For example, as a primary screw profile distribution, a curve indicated by a solid line γ in Fig. 23(a) may be obtained. In the curve γ, the waveform of the high frequency according to the noise overlaps with the waveform of the low frequency along the outline of the screw. Further, in the portion of the curve γ surrounded by the one-dot chain line Q3, the foreign matter adheres to the male screw, and the portion to which the foreign matter adheres also has a high-frequency waveform. The arithmetic control device 100 performs low-pass filtering on the curve γ to leave along A waveform having a frequency equal to or lower than a predetermined frequency fA set in advance in the Y direction of the axial direction, and a waveform having a frequency higher than the predetermined frequency fA is removed. The predetermined frequency fA is set in advance so as to increase the pitch of the screw from the ideal model of the design size of the screw to be measured. Thereby, the waveform of the high frequency according to the noise and the foreign matter is removed from the primary contour distribution of the curve γ, and the curve represented by the solid line δ in Fig. 23(b) is obtained twice, and the smooth waveform of the low frequency is obtained twice. Contour distribution.

The secondary contour distribution is obtained from each angle. Further, as shown in the above-described 11th, 12th, or 21st and 22th, the size of the workpiece 8 around the Y-axis, for example, the top diameter, the bottom diameter, and the maximum of each, is calculated based on the contour distribution of each angle. Value, minimum, and average. Further, the arithmetic and control device 100 prints and outputs the value calculated for the top diameter and the bottom diameter in the output device 104 (see FIG. 1).

Further, the processing performed by the low-pass filter shown in FIG. 23 may be a process of performing Fourier transform on the primary contour distribution, removing high-frequency components exceeding the predetermined frequency fA, and performing inverse Fourier transform. Thus, a curve of the curve δ of Fig. 23(b) is obtained. For example, the Fourier transform can be set as a fast Fourier transform (FFT), and the inverse Fourier transform can be set as an inverse fast Fourier transform (IFFT). Further, the case where the contour distribution of the male screw portion 2 of the workpiece 8 is low-pass filtered has been described above. On the other hand, in a portion other than the male screw portion 2 of the workpiece 8, for example, when the contour data 160 of the head R below the figure 10 has a high-frequency noise or an abnormal portion generated by a foreign matter, it may be low. Filtering reduces or eliminates the effects of noise and foreign matter.

Fig. 23 illustrates the case where the Y direction is low-pass filtered in the contour distribution of the workpiece 8. On the other hand, in the primary contour distribution of Fig. 23(a) or the secondary contour distribution of Fig. 23(b), the deviation in the Y-direction position due to the deviation of the angle θ around the Y-axis may be predicted. Further, the trajectory of the X-direction position is also low-pass filtered based on the point corrected by the deviation of the prediction. Specifically, the arithmetic control device 100 sets the contour data of every predetermined angular interval obtained when the workpiece 8 is rotated about the Y axis as described above with respect to the black data of the binarized boundary of the black and white in FIG. 9 . 1 screw contour distribution. Further, the arithmetic control device 100 predicts the deviation of the Y direction from the contour distribution of the workpiece 8 at predetermined angular intervals in accordance with the deviation of the workpiece 8 at predetermined angles. Further, the arithmetic and control device 100 performs low-pass filtering on the trajectory of the X-direction position of the point predicted based on the predicted offset deviation point in accordance with the angle of the workpiece 8 around the Y-axis. Moreover, this operation is repeated by a plurality of points of the contour distribution once to generate the secondary screw contour distribution after the filtering process. Further, the arithmetic and control unit 100 calculates the value of the dimension of the workpiece 8 around the Y axis based on the contour distribution after the filtering process. Further, the arithmetic and control device 100 prints and outputs the value calculated for the size around the Y axis in the output device 104 (see FIG. 1).

Fig. 24 is a view showing the change of the screw contour distribution once when the workpiece 8 is rotated every predetermined angle in the case where the contour portion of the predetermined angle of the workpiece 8 is obtained and the abnormal portion in the X direction is removed by the low-pass filter. Figure. Fig. 25(a) is a diagram showing the low-pass filtering of the trajectory of the X-direction position of the predetermined angle at a point of a part of the contour distribution of the workpiece 8. A map of the trajectory (a) before the filtering process and the trajectory (b) after the filtering process.

As shown in Fig. 24 (a), (b), and (c), it is considered that the workpiece 8 is rotated at the predetermined angle and in the same direction to form the angles θ 1 , θ 2, and θ 3 . In this case, since the male screw portion 2 of the workpiece 8 has a spiral shape, the primary screw profile distribution gradually deviates in the Y direction. In addition, each contour distribution of each predetermined angle is sometimes deviated in the X direction and the Y direction. For example, among the plurality of vertices G1, G3, G5, ... at the top and the bottom points G2, G4, ... at the bottom, attention is paid to the vertex G3 of one top. At this time, the deviation of the vertex G3 in the Y direction is predicted in advance based on the pitch of the screw to be measured, such as L1 and L2. Thus, the correction is performed by the deviations L1 and L2, and the vertices existing at the predetermined distance are predicted as the points G3 of the respective angles θ 1 and θ 2 based on the points G3a and G3b having the same position in the X direction as the point G3. . In Fig. 24, the point G3 of each angle θ 1 and θ 2 deviates from D1 and D2 in the X direction from points G3a and G3b. Further, with respect to the angle θ, the trajectory of the X-direction position of the predicted vertex G3 is represented by η 1 of Fig. 25(a). The horizontal axis of Fig. 25(a) shows the rotation angle θ of the workpiece 8 about the Y axis, and the vertical axis represents the position of the vertex G3 in the X direction.

As can be seen from Fig. 25(a), in the curve η 1 which is the trajectory of the position of the vertex G3 in the X direction, the waveform of the high frequency according to the noise overlaps with the waveform of the low frequency. Further, in the portion of the curve η 1 surrounded by the one-dot chain line Q4, the foreign matter is attached to the male screw portion of the workpiece 8 to form a high-frequency waveform.

The arithmetic control device 100 performs low-pass filtering on the curve η 1 along the Y direction to leave a frequency below a predetermined frequency fB set in advance. The waveform of the rate and the waveform of the frequency exceeding the predetermined frequency fB is removed. The predetermined frequency fB is set in advance according to a predetermined design size such as a pitch of a screw to be measured, a lead, and the like. Thereby, the waveform of the high frequency according to the noise and the foreign matter is removed from the curve η 1 , and the influence of the foreign matter is removed and smoothed as in the curve η 2 of FIG. 25( b ). In addition, it is preferable that the trajectory of the X-direction position of the vertex G3 is a constant straight line, but the holding state of the fastening chuck 70 (Fig. 1 or Fig. 15) of the workpiece 8 is maintained. Next, the workpiece 8 may be slightly inclined with respect to the up and down direction (Y direction). As described above, when the workpiece 8 is inclined, as shown in Fig. 25(b), the position in the X direction is liable to become a curve. The configuration shown in Figs. 24 and 25 described above is effective in reducing the influence of noise and foreign matter in the case where the workpiece 8 is inclined.

Further, the arithmetic control device 100 is also associated with the vertices G1, G5, ... including the tops of the vertices G3 of Fig. 24 and the bottom points G2, G4, ... of the bottom, and the X-direction positions of the plurality of positions of the contour distribution, and also the vertices. The G3 performs low-pass filtering as well. Further, the arithmetic control device 100 generates a secondary screw contour distribution after the filtering process of each angle θ in accordance with each vertex and each bottom point. Thereby, in the secondary screw profile distribution, the abnormal portion due to the adhesion of the foreign matter and the removal of the noise are performed. Further, the calculation control device 100 calculates the size of the workpiece 8 around the Y axis in accordance with the configuration shown in FIG. 11 , FIG. 12 or FIGS. 21 and 22 in accordance with the secondary contour distribution of each angle θ after the filtering process. For example, the maximum value, the minimum value, and the average value of the top diameter and the bottom diameter.

It should be noted that the utilization shown in the above FIG. 25 is used. In the case of processing by the low-pass filter, Fourier transform and inverse Fourier transform can also be used. Specifically, the trajectory of the X-direction position of the contour distribution shown in FIG. 25( a ) may be Fourier-transformed, and the high-frequency component exceeding the predetermined frequency fA may be removed, and then inverse Fourier transform may be performed to obtain the 25th. The processing of the curve of Figure (b). At this time, using FFT as the Fourier transform, IFFT can also be used as the inverse Fourier transform.

Fig. 26 is a view corresponding to Fig. 4 showing another example of the adapter for fixing the workpiece. In the configuration explained in Figs. 3 and 4, in the adapter 80 for fixing the workpiece 8, the screw depth of the male screw portion 2 of the workpiece 8 to the ring gauge 82a is precisely adjusted in units of one pitch length. The spacers 84a, 84b, 84c are used. On the other hand, in any of the configurations shown in Figs. 1 to 25, as shown in Fig. 26, the adapter 80d may be configured not to sandwich the spacer.

In the adapter 80d shown in Fig. 26, the lower surface of the other end surface of the ring gauge 82a is in contact with the upper surface of the stopper flange portion 90 of the bracket 86.

At this time, the male screw 92a of the bracket 86 is screwed into the reference female screw 83a of the ring gauge 82a from below. In this case, the length from the lower end of the ring gauge 82a to the upper end of the male screw 92a is the same as the protruding height HS of the male screw 92a from the upper surface of the stopper flange portion 90. Further, in the adapter 80d, the length of the male screw portion 2 (see FIGS. 3 and 4) of the workpiece 8 can be screwed from the upper side of the reference female screw 83a, that is, the screw length Lw is {(ring gauge 82a) Thickness DR) - (protruding height HS of the male thread 92a of the bracket 86)}. The screw length Lw is set to an integral multiple of the pitch Pc of the reference female thread 83a (=N× Pc). Here, N is an arbitrary integer.

Further, N1 and N2 may be arbitrary integers, and the thickness DR of the ring gauge 82a may be set to an integral multiple (= N1 × Pc) of the pitch Pc of the reference female screw 83a, and the protruding height of the male screw 92a of the bracket 86 may be set. Hs is also set to an integral multiple of the pitch Pc (= N2 × Pc).

When the bracket 86 is coupled to the ring gauge 82a, the male thread 92a of the bracket 86 is screwed into the reference female thread 83a of the ring gauge 82a from the lower surface side of the ring gauge 82a. Further, the front end portion of the male screw portion 2 of the workpiece 8 shown in Fig. 3 is screwed into the reference female screw 83a of the ring gauge 82a from the upper surface side of the ring gauge 82a, and the front end of the male screw portion 2 of the workpiece 8 is The front end of the male screw 92a of the bracket 86 abuts. Thereby, the workpiece 8 is fixed to the ring gauge 82a. At this time, as described above, the screw length Lw of the upper side of the ring gauge 82a is set to be an integral multiple of the pitch Pc of the reference female screw 83a. The screw length Lw is an engagement length Lw at which the male screw portion 2 of the workpiece 8 meshes with the ring gauge 82a, and can be accurately adjusted in units of lengths of one pitch. For example, in the case where (the thickness DR of the ring gauge 82a) is set to a length of 8 pitches and the protruding height Hs of the male screw 92a of the bracket 86 is set to 5 pitches, the meshing length of the male thread portion 2 of the workpiece 8 Lw can be adjusted to the length of 3 pitches. Therefore, the Y position of the front end portion of the male screw portion 2 of the workpiece 8 can be accurately determined from the measured value of the Y position of the upper surface of the ring gauge 82a.

Further, even when the screw of the same specification is used as the workpiece 8, the tip end portion of the male screw portion 2 may not be sufficiently meshed with the reference female screw 83a due to the fact that the distal end portion has an incomplete thread portion or the like. In view of this situation, in the adapter 80d, it is preferable to prepare the upper side screw A plurality of adapters having a length Lw that is a different integer multiple of the pitch Pc.

Further, as shown in Figs. 3 and 4, in the configuration in which the spacers 84a, 84b, and 84c are disposed between the ring gauge 82a and the bracket 86 to adjust the meshing length of the screw, it is important to improve the dimensional accuracy of the spacer. of. On the other hand, it is difficult to increase the dimensional accuracy of the spacer than to increase the dimensional accuracy of the ring gauge 82a having a large thickness. Therefore, in the configuration using the spacer, the measurement accuracy may be lower than the configuration of Fig. 26. In addition, the spacer is more easily deformed than the ring gauge 82a. According to the configuration of Fig. 26, the measurement accuracy can be improved as compared with the case of using the configuration of the spacer. In particular, in the case of a small screw having a small pitch Pc, it is preferable to use a member that engages with a shape with higher precision. In this point, the configuration of Fig. 26 is advantageous. In addition, the gasket can be omitted, so that cost reduction can be achieved. For example, the manufacturing cost of a high-precision adapter without a gasket is sometimes about the same as the manufacturing cost of a high-precision gasket.

10‧‧‧Automatic screw size measurement system

12‧‧‧Automatic screw size measuring device

14‧‧‧Anti-vibration table

15‧‧‧ frame

16‧‧‧Abutment

18, 19‧‧ ‧ pillar

20‧‧‧ top board

22, 23‧‧‧ rails

24, 25‧‧ ‧ threaded column

26‧‧‧Y stage

27, 28‧‧ ‧ bearing department

29‧‧‧Y motor

30‧‧‧ Sensor

31‧‧‧Land

32‧‧‧Optical measuring device

34‧‧‧Image Projection Department

36‧‧‧Light source

38‧‧‧Photo Camera

40‧‧‧ Head Measurement Department

42‧‧‧ head camera

44‧‧‧Laser light source

46‧‧‧Circular Lighting Department

48‧‧‧Installation board

50‧‧‧Focus Moving Department

52‧‧‧Z stage

54‧‧‧Z motor

56‧‧‧Removal of the mobile department

58‧‧‧X stage

60‧‧‧Piston cylinder mechanism

62‧‧‧ Holding the rotating part

64‧‧ θ motor

66‧‧‧Rotary joints

68‧‧‧The Department of Control

70‧‧‧ fastening chuck

80‧‧‧Adapter

100‧‧‧ arithmetic control device

102‧‧‧Air pressure control device

104‧‧‧Output device

106‧‧‧Checklist

110‧‧‧Thread diameter calculation unit

112‧‧‧Full-time calculation department

114‧‧‧Focus position calculation unit

116‧‧‧ Outline Data Calculation Department

118‧‧‧The first R calculation department

120‧‧‧ Head size calculation department

122‧‧‧ Head hole depth calculation unit

124‧‧‧Measurement data output department

Claims (13)

An automatic screw measuring system is a workpiece for measuring a screw. The screw size automatic measuring system includes: a grip portion that holds an axial end of the male thread of the workpiece; and a rotating portion that is rotated 360 degrees around the axial direction. The optical measuring device optically and non-contactly measures the size of the workpiece in which one end of the male screw in the axial direction is gripped by the grip portion, and an axial movement portion that causes the optical measuring device to move along the grip portion with respect to the grip portion And an arithmetic control device that calculates and outputs a dimension of the axial direction and the axis of the workpiece; wherein the calculation control device includes a screw diameter calculating unit that calculates a size related to a thread top of the workpiece and The dimension associated with the bottom of the thread; and the full length calculating unit calculates the total length along the axial direction of the workpiece. The automatic screw size measuring system according to claim 1, wherein the gripping portion comprises: an adapter having a disk-shaped outer shape and a female thread having a predetermined meshing length at a center of the end surface, the mother When the thread is screwed into the front end portion of the male screw of the workpiece, the thread can be fixed so that the axial direction of the workpiece does not shake; Fasten the chuck and clamp the outer peripheral side of the adapter at least 3 points. The automatic screw size measuring system according to claim 2, wherein the adapter has a ring gauge engraved with a reference female thread corresponding to a thread size of the male thread of the workpiece and having a predetermined meshing accuracy. And a disc-shaped bracket having an end surface protruding from the male thread engaged with the reference female thread of the ring gauge; wherein the circular shape of the bracket is a common shape regardless of the screw size of the workpiece. The automatic screw size measuring system according to the first aspect of the invention, wherein the axial direction is the Y direction, and the surface perpendicular to the Y direction is the XZ plane, and the screw size automatic measurement system includes a base, and the base The stage has an upper surface parallel to the XZ plane, and the grip portion is provided on the upper surface of the base so as to be rotatable about the axial direction, and the axial movement portion includes a moving table on which the optical measuring device is mounted, that is, The optical measuring device includes an image projection unit that measures the axial direction of the workpiece and the size of the axis around the moving table that can be moved to the Y position in the Y direction with respect to the base. The automatic screw size measuring system according to claim 4, wherein the image projection unit includes a light source that is disposed on one side in the Z direction with respect to a center line of the workpiece in the Y direction and outputs parallel rays; and a telecentric The projection imaging camera of the optical system is disposed on the other side in the Z direction with respect to the center line of the workpiece in the Y direction, receives the parallel light rays from the light source, and has the same projection shape as the light source of the image to be the workpiece The light-receiving optical axis is imaged only by imaging a component parallel to the optical axis on an imaging surface parallel to the XY plane. The automatic screw size measuring system according to claim 5, wherein the arithmetic control device includes a contour data calculating unit that converts projection shape data of the workpiece captured by the projection imaging camera into an arbitrary position analysis. The two-dimensional data of the bit map is used, and each data of the aforementioned two-dimensional data of the bit map is binarized into black and white using a predetermined threshold. The automatic screw size measuring system according to the sixth aspect of the invention, wherein the contour data calculating unit performs the data in the binarized boundary of the black and white from the workpiece according to a preset noise determination criterion. Observed by a cross-sectional view and become abnormal data as a noise The contouring data indicating the distribution of the screw contour is obtained by the smoothing process, and the contour data calculating unit calculates and outputs the contour data at intervals of a predetermined angular interval when the workpiece is rotated 360 degrees around the Y axis. The axial and circumferential dimensions of the workpiece. The automatic screw size measuring system according to claim 7, wherein the screw size automatic measuring system includes a focusing moving unit that moves the projection imaging camera in the Z direction, and the arithmetic control device includes The focus position calculation unit is a pre-processing for converting into the bit map, and the focus position calculation unit converts the projection shape data of the screw imaged by the projection imaging camera from the white data to the edge region of the black data. In the method of obtaining the maximum value of the black and white boundary of the projection shape data, the evaluation function is used to obtain the evaluation function of each Z position while moving the projection imaging camera in the Z direction by the focus moving unit. The Z position at which the value of the evaluation function becomes the maximum value is the focus position, and the Z-direction position of the projection imaging camera is fixed. The automatic screw size measuring system according to claim 7 or 8, wherein the arithmetic control device determines the size of the workpiece about the Y-axis from the contour data of the workpiece at every predetermined angular interval. a group of measured data, The measurement data of the above-described size that is out of the predetermined lower limit threshold value to the preset upper limit threshold value is excluded, and the value of the size around the Y-axis is calculated and output based on the remaining group of the measurement data of the aforementioned size. To the output device. The automatic screw size measuring system according to claim 6, wherein the arithmetic control device performs smoothing processing on the boundary of the binarization of the black and white by: winding the workpiece around the Y axis In the contour data of every predetermined angular interval obtained at the time of rotation, the trajectory of the measurement data continuous along the Y direction of the workpiece is subjected to low-pass filtering of a predetermined frequency set in advance. The automatic screw size measuring system according to the sixth aspect of the invention, wherein the calculation control device is configured to calculate a boundary between the black and white binarization, and to obtain a predetermined time for the workpiece to be rotated about the Y axis. The contour data of the angular interval is predicted by the plurality of points corrected by the deviation of the angle of the workpiece around the Y axis by the deviation of the Y direction generated by the predetermined deviation of the workpiece at a predetermined angle. The trajectory of the X-direction position of the point is low-pass filtered to generate the contour data after the filtering process, and the value of the dimension of the workpiece around the Y-axis is calculated based on the contour data after the filtering process and output to the output device. An automatic screw size measuring system according to claim 1, wherein The workpiece is a head screw having a head portion and a screw shaft portion and having a rotation groove or a rotation hole for fastening a tool on the head portion, and the optical measuring device includes a head measuring portion that measures a depth of a head hole of the workpiece. The automatic screw size measuring system according to claim 12, wherein the head measuring unit includes a head imaging camera that captures a shape of the head hole of the workpiece on an imaging surface parallel to the XZ plane; And a laser light source that emits a light beam extending linearly on the XZ plane over the upper surface of the head portion of the workpiece and the bottom surface of the head hole at a predetermined inclination angle with respect to the Y direction of the workpiece, The calculation control device includes: a head size calculation unit that calculates a head size of the workpiece based on the image data of the head imaging camera; and a head hole depth calculation unit that detects the irradiation from the laser light source by the head imaging camera The linear beam is projected on the upper surface of the head and the bottom surface of the head hole, and the head hole is calculated according to the detected displacement amount on the XZ plane of each projection position and a predetermined tilt angle. depth.