JP4677603B2 - Screw shaft diameter measuring device - Google Patents

Description

  The present invention relates to a screw shaft diameter measuring apparatus capable of continuously measuring a screw shaft diameter with high accuracy by means of an optical system.

  As a means of measuring the length, shape, presence or absence of screws, etc., the method of measuring dimensions manually by contact-type measuring means such as calipers or micrometers is often used to measure a large number of screws. Since it takes time and manpower, various detection means for optical systems have been proposed as means for performing high-speed measurement continuously with high accuracy. Patent Document 1 “Screw Thread Detection Device” irradiates light from a light source onto a thread of a screw sent by a transfer means, and receives light reflected from the surface of the thread with a photoreceptor, so that the thread is normal. Whether it is detected. In this device, the light source beam is inclined 30 degrees with respect to the screw axis, and the surface of the screw is irradiated with a thin linear beam. When the reflected light is received, the screw thread is normal. Is determined.

  In the “screw inspection apparatus” of Patent Document 2, the length under the neck of the screw, the head diameter of the screw, and the presence / absence of the screw portion are measured at each inspection stage to determine whether the screw is good or bad. I have to. The under-head length of the screw and the head diameter of the screw are measured by a solid-state image pickup means comprising a plurality of diodes that receive light from the light projecting means. The presence or absence of the threaded portion is determined by detecting the oblique diffraction pattern on the virtual screen with a light receiving element that irradiates the threaded portion with laser light and receiving the diffracted laser light generated by the threaded portion. When this occurs, the light receiving element determines that there is no thread by not outputting a signal.

  In addition to the above-mentioned Patent Documents 1 and 2, various proposals have been made regarding screw inspection devices, but most of them are inspection devices for the length of the thread and the quality of the thread. However, whether or not the screw shaft diameter is manufactured to an accurate dimension when judging the quality of the screw is one of the important items in the inspection, the conventional inspections in the above-mentioned Patent Documents 1 and 2 etc. The device cannot measure the screw shaft diameter. Although this technique is completely different from the method of measuring the screw shaft diameter, a “laser wire diameter measuring device” of Patent Document 3 is known as a technique related to the technique of measuring the diameter of the filament.

  This measuring apparatus emits a laser beam from a laser light emitting part as a parallel beam by a mirror and a lens, condenses it by a condensing lens, receives it by a light receiving element, and places a measuring object placed between the two lenses. The change in the intensity of the laser beam blocked by the steel wire strip is output as a change in the output voltage by the light receiving element and sensed by the measuring unit. Since the object to be measured is a parallel strip of the same diameter, the wire diameter can be measured by irradiating a parallel beam in one direction in the length direction of the strip in a direction perpendicular to the strip.

  In this device, in order to measure the diameter of the wire strip on the entire circumference, both ends of the wire strip are fixed to the rotating plate, the wire strip is rotated together with the rotating plate by the handle, and the parallel beam is applied to the entire circumference of the wire strip. I try to irradiate. However, even if a parallel beam is irradiated to an object having peaks and valleys at a position in the length direction such as a screw, the measured value greatly varies depending on the position in the length direction, and the diameter along the length direction varies. It takes a long time to measure, and therefore is not suitable as a means for measuring the diameter of an object such as a screw.

On the other hand, when it is necessary to accurately measure the screw shaft diameter in screw inspection, at present, the illumination light from the light source irradiates the screw in a direction perpendicular to the screw axis, and an imaging means such as a CCD camera. The image information of the screw is taken in, the edge of the screw pitch is detected on both sides by the image processing device with built-in image processing program, and the screw shaft diameter is calculated from the edge signal to calculate the screw shaft diameter. Means are adopted. However, in such a measuring unit, since the image light to the imaging unit is irradiated with the irradiation light (backlight) behind the screw from the direction orthogonal to the screw axis, the scattered light to the screw of the backlight is converted into the image light. In some cases, clear image light may not be obtained due to interference, especially when the screw diameter is small in the M2 or M3 class, and the effect becomes large. There is a problem that it is not suitable for measuring.
JP-A-55-70702 Japanese Patent Laid-Open No. 57-192813 JP-A-11-166815

In consideration of the above-mentioned problems, the present invention is a means for measuring the outer diameter of a screw to be inspected, a screw that can be measured continuously and accurately with high accuracy, is easy to operate, and is inexpensive. It is an object to provide a shaft diameter measuring device.
Another object of the present invention is to provide a screw shaft diameter measuring device capable of continuously and accurately measuring the screw shaft diameter with image light.

As a means for solving the above-mentioned problems, the present invention provides an inspection in which a screw to be inspected is suspended from a notch on the outer periphery with the head supported, and the screw is driven to rotate around a vertical axis to convey the screw in the rotation direction. A table is provided, and a laser irradiation unit for emitting laser light as a parallel beam wider than the screw diameter with respect to the screw to be inspected, and a light receiving unit having a light receiving element for receiving the parallel beam from the laser irradiation unit are screwed. The optical means arranged opposite to each other are provided so as to be able to tilt and ascend and descend, and by tilting the optical means, the irradiation direction of the parallel beam to the screw is tilted to a predetermined angle or more, and in this state, the optical means is moved in the length direction of the screw. the passage area of the parallel beam by elevating detected by the light receiving unit for a predetermined length range of the screw, the screw shaft diameter having a calculating means for calculating the screw shaft diameter based on the detection signal It was a constant device.

According to the screw shaft diameter measuring apparatus of the present invention configured as described above, the optical means by the irradiating unit and the light receiving unit is set in a predetermined inclination with respect to the screw shaft, and the screw shaft diameter is raised and lowered by moving the optical means up and down. Can be measured easily, quickly, accurately and reliably. The laser of the optical means is irradiated onto the screw shaft as a parallel beam having a predetermined width wider than at least the screw shaft diameter. The predetermined inclination angle differs depending on the type of the screw shaft, but is set to an angle suitable for measuring each screw shaft diameter. The screw shaft diameter is measured by irradiating a parallel beam of laser light in a predetermined tilt state, and the detection signal indicating the boundary between the transmitted light in the passage region of the parallel beam and both ends of the light shielding portion shielded by the screw Accordingly, a parallel beam of laser light is applied to the screw in an inclined manner so as to obtain a signal in which the outermost diameter of the screw is connected.

  The parallel beam of laser light has high linearity, and when the irradiation unit and the light receiving unit are installed at a distance of m units, the spread of the parallel beam is negligible. The boundary represents the boundary area with extremely high accuracy. Therefore, it is possible to measure not only large screws but also small diameter screws such as M2 and M3 within a measurement error range of the order of μm.

In this case, represents a screw shaft diameter of the boundary line screw, line of this border is obtained by lifting the entire optical means, and the boundary line if the inclination angle is given below di Kuzagu The screw shaft diameter cannot be measured. This is because the irradiation light passes through the screw shaft diameter due to the influence of the thread valley. Therefore, in order to avoid this influence, it is necessary to set the inclination angle to an angle that is not affected by the thread valley. The parallel beam of the laser beam irradiated with the setting as described above has a light intensity greatly different between the beam passing outside the screw shaft diameter and the shielded region.

  The light receiving unit has different light receiving amounts in the light transmission region and the light shielding region of the parallel beam of the laser beam. The light receiving signal is converted into an electric signal and sent to the calculation means, and the screw shaft diameter is calculated from the width of the light shielding region. Is calculated by In the calculation of the screw shaft diameter, the design value is stored in advance in the storage unit as a reference value, the measured value of the screw shaft diameter calculated by the above calculation is compared, and if it is within a predetermined error range It is preferable to process the production of the screw shaft diameter as normal, output a signal to that effect, and display the measured value.

According to a second aspect of the present invention, as a means for solving the above-mentioned another problem, a screw to be inspected is suspended from a notch on the outer periphery while supporting the head, and the screw is rotated about a vertical axis to rotate the screw. In addition, a visible light beam irradiating unit 11 ′ for irradiating the entire length of the screw to be inspected and an imaging means 12 ′ for receiving the image light of the irradiated screw are arranged opposite to each other with a screw interposed therebetween. The image detection means is provided so that it can be tilted, and by tilting the image detection means, the irradiation direction of the irradiation light to the screw is linear, and the boundary line between the light shielding portion by the screw in the image light and the non-light shielding portion having the outermost diameter of the screw is straight The region over the predetermined range length of the boundary line between the image light and the transmitted light is detected by image processing, the screw shaft diameter is calculated from the detected data, and the screw shaft diameter is calculated by image processing. Provide screw shaft diameter calculation means to calculate It was a screw shaft diameter measurement device.

According to the screw shaft diameter measuring apparatus of the second invention, a visible light (white light) beam is irradiated, the image light of the screw is picked up by the image pickup means, the image signal is image-processed, and both edges of the screw shaft are processed. of detecting the boundary line to obtain the screw shaft diameter is calculated by the program for calculating the screw shaft diameter from the detection signal of the boundary line of the end edges. When this image light is picked up, the visible light beam is applied to the screw at an inclination of a predetermined angle or more, so that the image light includes an image of the entire screw and at the same time, the transmitted light from the passing region of the outermost diameter of the screw and the light shielding. Including the state of boundaries with both ends.

In the boundary state, since the irradiation light is inclined, a boundary line representing the screw shaft diameter connecting the outermost diameters of the screws, which are both ends of the screw shaft, is formed, and the screw shaft is detected from the detection signal of the image light of the boundary line. Calculate the diameter. Even if the screw shaft diameter is calculated by image processing in this way, the screw shaft diameter is calculated from the boundary line corresponding to the outermost diameter of the screw. Therefore, the program is simpler than detecting and calculating the edge of the outermost diameter of the screw from all the image data, and thus the processing speed is increased.

  The screw shaft diameter measuring apparatus according to the first aspect of the invention irradiates a screw with a parallel beam of laser light from a laser irradiation unit in a predetermined inclination state, converts a signal received by the light receiving unit into an electric signal, and converts the signal into an electric signal. Since the screw shaft diameter is calculated based on the calculation, the screw shaft diameter can be obtained with high accuracy even for small-diameter screws, and the measuring device can be obtained quickly, accurately, reliably and inexpensively with simple operation. Can be obtained.

  A screw shaft diameter measuring apparatus according to a second aspect of the present invention is to image image light by a visible light beam irradiated on a screw with an image pickup means, detect a boundary line between the screw shaft outer diameter and a light shielding portion from the image light, and Since the outer diameter is obtained, the screw shaft diameter can be calculated by simplifying the image processing technique, and the screw shaft diameter can be obtained quickly and accurately.

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1A is a plan view of an overall schematic configuration of a screw inspection apparatus according to a first embodiment, and FIG. 1B is a partial side view of the screw inspection apparatus viewed from an arrow Ib-Ib in FIGS. The screw inspection apparatus A of this embodiment includes an inspection table 2 that is rotatably driven (a motor is not shown) on a support column 1 _R that is erected on an inspection table 1, and has a predetermined outer periphery of the inspection table 2. screw feed means 4 for the inspected threaded bolt T _B in a plurality of locations forming the notch 3 in angular pitch fitted to supply the radial direction of the table at a predetermined position is provided. 4a is a guide means for fitting a screw bolt into the notch 3.

Notch 3 is formed in a long hole shape, including semicircular or semi-circular portion, mated threaded bolt T _B to the cutout 3, which is fixed at a slight clearance and the outer circumference of the examination table 2 A screw shaft that is guided along the inner peripheral surface of the holding plate 5 and is sent by the rotation of the inspection table 2 in the direction of the arrow in the drawing (see FIG. (A)), and is provided near the starting end of the holding plate 5. The diameter of the screw shaft is measured by the diameter measuring device 10. The inspection table 2 is intermittently driven using a stepping motor, for example, so as to be rotated and stopped at a predetermined angular pitch. When the inspection table 2 is moved by a predetermined pitch, the supply of the screw bolt and the measurement of the screw shaft diameter by the screw shaft diameter measuring device 10 are performed in parallel. It is done.

A screw shaft diameter measuring device 10 includes a laser irradiation section 11 for emitting a laser beam as a parallel beam, as sandwiched therebetween support means a threaded bolt T _B on examination table 2 and a light receiving portion 12 for receiving the parallel beam P _B The support arm 13 is provided opposite to both ends. The support arm 13 is formed in a U-shape when viewed from the side, and one end of the base portion 13a of the support arm 13 is connected to a substantially middle position of the support arm 13, and the other end is connected to the lift plate 14 so as to be movable up and down within the long hole 13b. It is connected via a pin 15. The pin 15 is provided with a fastening nut 16. By rotating the fastening nut 16 and tightening the pin 15, the support arm 13 is fixed at a predetermined inclination, and if necessary, the fastening nut 16 is loosened and the inclination angle is increased. Can be adjusted.

  The elevating plate 14 is slidably provided in the guide member 17, and a rack and pinion mechanism (not shown) is connected to the elevating plate, and the pinion is rotationally driven by a motor so as to be raised and lowered. In addition to the rack and pinion, the elevating plate 14 may be connected to the protruding end of the piston rod connected to the piston in the hydraulic cylinder so that the elevating plate 14 can be raised and lowered by the hydraulic pressure. If possible, various other lifting means can be used. Further, as a fastening means for fastening the inclination angle of the base portion 13a of the support arm 13 with respect to the lifting plate 14 so as to be adjustable, an electric motor is connected to the end of the pin 15 in place of the manual fastening nut 16 so that automatic fastening can be performed. It may be.

Screw feed means 4 is provided with a pair of rails arranged in parallel, the gap between the rails threaded bolt T _B of the threaded portion N (in FIG. 4 (b), (c) see figure) than the diameter D _N of rather broadly, and because it is provided narrower than the head portion H of the threaded bolt T _B, catching the head H of the threaded bolt T _B is the rail, the screw portion N sag between the rails, a number of screws in this state bolt T _B is fed to the periphery of the sequential examination table. 4a is a guide part. The holding plate 5 is provided along a substantially ¼ arc of the outer periphery of the inspection table 2 and is not shown, but other items of the screw inspection device, such as screw length, screw head, etc. Means for individually inspecting are provided under the holding plate 5 in order.

  2A is a plan view of the schematic configuration of the optical member of the screw shaft diameter measuring apparatus 10, and FIG. 2B is a perspective view thereof. The laser irradiation unit 11 includes a laser beam generation unit 11a using a semiconductor laser, a reflection mirror 11b that reflects the laser beam, and a prism 11c that converts the reflected laser beam into a parallel beam. Reference numeral 11d denotes a transmission window. The semiconductor laser in the illustrated example generates visible laser light having a wavelength of 650 nm as continuous light (cw). The light receiving unit 12 includes a condensing lens 12a that condenses the parallel beam transmitted through the transmission window 12c, and a planar matrix photoelectric conversion element 12b that receives the collected light and converts it into an electric signal. . La is a power supply line, and Lb is an output line including a photoelectric conversion signal and a power supply.

FIG. 3 shows a block diagram of the computing means 20 which is a signal processing circuit by the laser irradiation unit 11 and the light receiving unit 12 of the optical member of the screw shaft diameter measuring apparatus 10. The signal received by the light receiving unit 12 is converted into an electric signal by the photoelectric conversion element, and the electric signal is converted into a binarized signal by the signal detecting unit 21 to detect the change state of the parallel beam. To the calculation unit (microcomputer, CPU) 22, the screw shaft diameter is calculated by calculation in the calculation unit 22, and a numerical value is displayed on the display unit 23. Also, by elevating the optical member (11, 12) on the basis of the operation signal from an input unit E _X, also the examination table 2 fitted with a threaded bolt T _B to be inspected to move by a predetermined pitch, to the driving unit 24 A control signal is sent to drive the drive motor 17M of the rack and pinion mechanism connected to the guide member 17 of the elevating plate 14 and the motor of the table 2.

According to the screw shaft diameter measuring device 10 of the screw inspection apparatus A of the embodiment has a configuration described above, the screw shaft diameter of the screw bolt T _B from the large diameter to be inspected as follows: to a small diameter of about 2~3mm Highly accurate, accurate, reliable, quick and easy measurement. Threaded bolt T _B is supplied to the examination table 2, table 2 proceeds to the position of the screw shaft diameter measuring device 10 is rotated a predetermined pitch measurement of the screw shaft diameter is performed. In this measurement, a collimated beam P _B of the laser beam emitted from the laser irradiation unit 11, for receiving against the parallel beam P _B across the threaded bolt T _B by the light receiving portion 12. Parallel beam P _B is wider than the diameter of at least inspected threaded bolt T _B, the thickness is in mm, to be irradiated as the inspection light, strong energy level of about damaging the threaded bolt T _B Is not the light. In the illustrated example, the parallel beam P _B (FIG. 2A), for example, having a width B of 10 mm or 30 mm is used.

When irradiating the collimated beam _{P B} into threaded bolt _{T B,} previously supporting arm 13, as shown in (b) FIG. 4, at least 45 ° to the horizontal support surface of the threaded bolt _{T B} to 60 The direction is set to be inclined at a predetermined angle of °. The support arm 13 is vertically moved along the length of the threaded bolt T _B at the predetermined inclined state, thus parallel beam P _B irradiation gradually from the lower end of the threaded bolt T _B until a substantially intermediate length position The position moves. Such parallel beam P _B continuously during the vertical movement is irradiated, the optical signal at each position is received by the light receiving unit 12 and converted into an electric signal as a signal for measuring the diameter of the threaded bolt T _B .

When irradiating the collimated beam P _B into threaded bolt T _B, the laser beam striking the diameter of the screw bolt T _B is shielded (shielding portion P _BO), the laser beam of light is shielded not part pass intact to the light receiving portion 12 Received light. In this case, parallel beam P _B is to be irradiated on the threaded bolt T _B to a predetermined inclined, passing through a recess slope of the valley of the thread to form the laser beam is no longer (protected from light), the thread Only laser light that passes outside from the top passes. This is because the inclination of the slope of the screw thread differs depending on the type of screw, but even if the type of screw is different, if the irradiation angle of the parallel beam is about 45 ° to 60 °, the light is almost shielded, and the laser is only outside the top of the screw thread. This is because light cannot pass through.

Incidentally, the closer the irradiation angle in the horizontal direction and 45 ° or less with respect to the screw bolt T _B parallel beam P _B, the recess by the slope of the valley of the thread passes through the laser beam, the width being blocked is threaded bolt T _B It becomes difficult to detect a signal representing a diameter that varies depending on the position in the length direction. Depending on the irradiation angle, the concave portion becomes a diffraction grating for laser light, and weak diffracted light is refracted and proceeds to the light shielding region, so that the light receiving element of the light receiving portion 12 receives light. The process of detecting is difficult. For this reason, the parallel beam P _B is set to an inclined state that is equal to or greater than the predetermined value.

As described above, receives the laser beam that passes outside of the top portion of the thread in the light receiving section 12, and the parallel beam P _B elevating along the length of the threaded bolt T _B, each height position only the laser light representing the screw shaft diameter is received by the light receiving portion 12, so that the signal representing the screw shaft diameter of each height position, the outer L _DL of threaded bolt T _B as shown in (c) of FIG. 4 , _LDR is a position signal represented as a straight line connecting LDR. Such a position signal is obtained by converting the amount of light (light intensity) in the light receiving region of the light receiving signal for each height position into an electric signal and detecting it by the signal detection unit 21 of the computing means 20. Then, so that the diameter D _N shown in (c) diagram of Figure 4 by a calculation for calculating a difference between the position signal in the arithmetic unit 22 is obtained. Incidentally, obtained (c) figure 4 shows a state in which visual observation also from the inclined direction the screw bolt _{T B} parallel beam _{P B, L} DL in the _drawing, the value of _{L DR,} namely the diameter _{D N} is the calculated It is done.

Further, the diameter D _N of the measured threaded bolt T _B should fabrication of the threaded bolt T _B is equal to the value of the design value if accurate. However, since actually the fabrication error in the molding of the screw shaft is contained usually the value of the measured diameter D _N compared as a reference value design value comparison unit in the arithmetic unit 22, within a predetermined error production of Arebaneji bolt T _B shall be treated as normal. However, the predetermined error may be such that the value of the diameter at each height position is within a few percent (large or small) of the reference value. In this embodiment, a small and inexpensive semiconductor laser is used as the light source of the laser irradiation unit 11. However, for example, a He-Ne laser, a YAG laser, or other types of laser light may be used.

The setting of the inclination angle of the parallel beam P _B of the laser beam in the above embodiment, although the predetermined angle or more that can measure the screw shaft diameter, the setting angle of the collimated beam slightly before measuring the screw shaft diameter If the screw thread is set to such an extent that it can be determined, the difference in screw pitch can be determined. When viewed threaded bolt T _B from the light receiving unit 12 and the extent to which the thread can be determined, in a little inclination angle of the front left and right sides becomes vertical linearly as described above, from the respective thread visible in that direction The measured value corresponding to the concave part due to the inclined surface is obtained by entering the valley of the screw a little.

  Accordingly, a position where the maximum diameter is set at the maximum diameter at one screw thread and a position where the diameter is smaller in the longitudinal direction of the screw shaft than the shaft diameter around the screw thread, and the adjacent maximum diameter If a calculation program is provided in the calculation means 20 so as to calculate the position difference in the length direction with respect to the position, the screw pitch of the measurement object can be measured based on the position difference of the maximum diameter. Then, by comparing the measurement data of the screw pitch for each screw, the difference in the screw pitch for each screw can be determined. For example, the difference in the pitch between the tapping screw and the normal manifold screw can be determined. That is, by providing such a function, it is possible to inspect for mixing of different products as to whether screws of different screw types are mixed.

  FIG. 5 shows (a) a partial perspective view and (b) a schematic system diagram of a screw shaft diameter measuring device 10 ′ according to the second embodiment. In the second embodiment, unlike the first embodiment, a general visible light is used as a light source to irradiate a screw, the image light is received by the imaging means 12 ′, and the image processing apparatus 22 ′ that processes the image light. Thus, the screw shaft diameter measuring device 10 ′ for measuring the screw shaft diameter is obtained. However, the light from the irradiation unit 11 ′ is set to have a predetermined inclination as in the first embodiment. In this case, the light from the irradiation unit 11 ′ is not a parallel beam of laser light, but a general visible light beam (white light) composed of a light beam having a diameter or width including the screw portion of the screw. A white light lamp, an Xe lamp, an LED light emitting element, or the like is used as the light source. The light receiving unit uses an imaging means 12 'such as a CCD camera.

The image signal picked up by the image pickup means 12 ′ is sent to the signal detection unit 21 ′, where it is converted into a binary signal and sent to the image processing device 22 ′ by a small computer (personal computer). Reference numeral 23 'denotes a display unit, and Ex denotes an input means. This is the image processing apparatus 22 ', the fed image signal contains signal border by shading the light shielding portion by the screw and transmitted light, of the boundary line over a predetermined range longitudinal length of the screw Image processing for extracting a signal from another image light signal is performed. Then, the screw shaft diameter is calculated by a program that calculates the screw shaft diameter from the signals of the boundary lines at both end positions of the outermost diameter of the obtained screw. The irradiating unit 11 ′ and the imaging unit 12 ′ are provided at appropriate positions in an inclined manner (however, the inclination angle is provided so as to be adjustable), and no elevating unit is provided.

According to the screw shaft diameter measuring apparatus 10 ′ having the above-described configuration, by detecting a signal at the boundary portion of the outermost diameter of the screw representing the screw shaft diameter from the image signal of the screw, the edge signal in the image signal of the entire screw is detected. Rather than obtaining the screw shaft diameter by image processing, the screw shaft diameter is calculated directly from a signal representing the screw shaft diameter. For this reason, the image processing program can detect the screw shaft diameter more easily and with higher accuracy than a general image processing program. Therefore, since the screw shaft diameter is directly calculated from the measurement of the screw shaft diameter by general image processing, the measurement can be performed quickly and with high accuracy. In this case as well, the design value of the screw diameter is used as a reference value, and it is compared with the reference value to determine whether or not the measured value is within a predetermined error range. Display in '.

  The screw shaft diameter measuring apparatus according to the present invention measures the screw shaft diameter directly and quickly with the optical system inclined, and is used as a measuring means for important inspection items of the screw inspection apparatus.

(A) Top view of whole schematic structure of screw inspection apparatus of 1st Embodiment, (b) Partial side view from arrow Ib-Ib of (a) figure (A) Top view of schematic structure of screw shaft diameter measuring device, (b) Perspective view Block diagram of the signal processing circuit of the optical means of the same apparatus (A) Explanatory view of measuring action by screw shaft diameter measuring device as viewed from obliquely below screw bolt, (b) Measurement state view from side of screw bolt, (c) Perspective view of screw bolt viewed from parallel beam traveling direction (A) Block diagram of schematic configuration of screw shaft diameter measuring device of second embodiment, (b) Explanatory drawing viewed from diagonally below screw bolt

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Inspection table 2 Inspection table 3 Notch 4 Screw supply means 5 Holding plate 10, 10 'Screw shaft diameter measuring device 11 Laser irradiation part 12 Light receiving part 13 Support arm 14 Lifting plate 17 Guide member 20 Calculation means 21 Signal detection part 22 Calculation Part A Screw inspection device T _B Screw bolt P _B Parallel beam

Claims (3)

An inspection table (2) is provided in which the screw to be inspected is suspended from the outer notch (3) while supporting the head, and is rotated about a vertical axis to convey the screw in the rotation direction. laser irradiation unit for emitting a laser beam to subject the screw as parallel beam wider than the screw diameter (11) and the light receiving portion having a receiving element for receiving the parallel beam (P _B) from the laser emitter (11) (12) and the provided facing the optical means tiltably and lifting disposed across the screw, the irradiation direction of the collimated beam to the screw by tilting the optical means (P _B), the parallel beam (P _B The detection signal representing the boundary between the transmitted light in the passage region and the both ends of the light-shielding part is inclined to an angle that becomes a signal representing the screw shaft diameter connecting the outermost diameters of the screws as the parallel beam (P _B ) moves up and down. , screw optical means in this state Arithmetic means for receiving part for a predetermined length range of the screw passage area of the parallel beam by elevating the length (P _B) is detected by (12), calculates the screw shaft diameter based on the detection signal (20 ) Screw shaft diameter measuring device. The screw shaft diameter measuring device according to claim 1 , wherein the optical means is provided on a support arm (13) , and the support arm (13) is provided so as to be inclined and liftable. An inspection table (2) is provided in which the screw to be inspected is suspended from the outer notch (3) while supporting the head, and is rotated about a vertical axis to convey the screw in the rotation direction. An image detecting means in which a visible light beam irradiating portion (11 ′) for irradiating the entire length of the target screw and an imaging means (12 ′) for receiving image light of the irradiated screw are arranged to face each other with the screw interposed therebetween. capable provided, the irradiation direction of the irradiation light to the screw by tilting the image detection means, the boundary line between the transmitted light passing areas of the light shielding portion and the screw outermost diameter by screws in the image light is close to a straight line consisting angle is inclined, the upper Symbol regions over a predetermined range the length of the boundary line between the transmitted light shielding portion of the image light is detected by image processing, a screw by image processing by calculating the screw shaft diameter from the detected data Screw shaft with screw shaft diameter calculation means to calculate shaft diameter Measuring device.

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