JP2007010336A - Method and device for inspecting appearance - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an appearance inspection device for simplifying the inspection method and shortening the inspection time, by simultaneously performing, in one operation, appearance inspection of an inspected object, especially a plurality of appearance inspections of length dimension of the inspected object with a circular outline, roughness of each end face, and the like. <P>SOLUTION: The appearance inspection device comprises a driving means 2 for rotating a cylinder pipe 1 at a fixed position, a pair of displacement gauges 3 that are arranged on both axial sides of the cylinder pipe 1, radiate respective laser beams to both end faces 4 of the cylinder pipe 1, and detect the reflected light, and a controller 5 for inspecting the length dimension of the cylinder pipe 1, the roughness of the end faces 4, and chamfers 7a and 7b of the end faces 4 based on the displacement of each end face 4 obtained from the displacement gauges 3. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an appearance inspection method and an apparatus for inspecting a length dimension, a surface roughness of an end surface, and the like of an inspection object having a circular outer shape such as a cylindrical body or a cylindrical body.

  Conventionally, as this kind of appearance inspection method, for example, the surface of a cylindrical body is irradiated with a light beam, the reflected light is detected by an optical sensor, and the output of the optical sensor is compared with a reference value by an arithmetic circuit. A method for measuring body dimensions is known (Patent Document 1). In addition, a light beam is scanned from the outside of one end surface to the outside of the other end surface of the substrate that moves straight or rotates, and the reflected light reflected from the surface and end surface of the substrate is received by the light receiving sensor, and the output signal from the light receiving sensor There is also known a method for inspecting defects on the substrate surface and the end face by processing the above (Patent Document 2).

However, as described above, visual inspection methods using a light beam are already known. However, these inspection methods have only one item to be inspected. When trying to inspect the appearance of defects, they must be inspected separately, which is troublesome and takes an inspection time.
JP 2001-255119 A JP 2002-181717 A

  Therefore, the problem to be solved by the present invention is to perform a plurality of appearance inspections such as the length inspection of the inspection object having a circular outer shape and the surface roughness of each end surface in one operation. It is possible to provide an appearance inspection method and an apparatus thereof that can be performed at the same time to simplify the inspection method and shorten the inspection time.

  In order to achieve such an object, the visual inspection method according to the present invention irradiates laser light along the circumferential direction to both end faces of an inspection object having a circular outer shape, and detects reflected light from each end face. Thus, the displacement of each end face is obtained, and the length dimension of the object to be inspected and the surface roughness of the end face are inspected based on the displacement value.

  In addition, another visual inspection method according to the present invention irradiates laser light along the circumferential direction on both end faces of a test object having a circular outer shape, and diametrically applies to peripheral edges of both end faces of the test object. Irradiate laser light along the line, detect the reflected light from each end face, determine the displacement of each end face, and inspect the length dimension, end surface roughness, and end face shape of the inspected object based on this displacement value It is characterized by doing.

  Further, an appearance inspection apparatus according to the present invention is arranged on both sides in the axial direction of the inspection object, driving means for rotating the inspection object having a circular outer shape at a fixed position, and on both end surfaces of the inspection object. A pair of displacement meters each irradiating laser light and detecting the reflected light, and an inspection for inspecting the length dimension of the object to be inspected and the surface roughness of the end surface based on the displacement value of each end surface obtained from the displacement meter Means.

  Further, another appearance inspection apparatus according to the present invention includes a driving means for rotating an inspection object having a circular outer shape at a fixed position, and both ends of the inspection object in the axial direction, and both ends of the inspection object. A pair of displacement meters that irradiate the surface with laser light and detect the reflected light, and the length dimension of the object to be inspected, the surface roughness of the end surface, and the end surface based on the displacement value of each end surface obtained from the displacement meter Inspecting means for inspecting the shape is provided.

  The appearance inspection method of the present invention is capable of performing a plurality of appearance inspections such as a length dimension of an inspection object having a circular outer shape and a surface roughness of each end surface in one operation. Therefore, the inspection method can be simplified and the inspection time can be shortened.

  In addition, the appearance inspection apparatus of the present invention has an effect that the appearance inspection method can be executed by an extremely simple means.

  Embodiments of an appearance inspection method and apparatus according to the present invention will be described below in detail with reference to the accompanying drawings. 1 to 4 show an inspection unit which is a main part of the appearance inspection apparatus according to the present invention. This inspection unit includes a driving means 2 for rotating an object to be inspected having a circular outer shape (in this example, a cylindrical tube 1) at a fixed position, and a pair of displacement meters 3 disposed on both sides of the cylindrical tube 1 in the axial direction. Based on the displacement data of each end face 4 of the cylindrical tube 1 obtained from the displacement meter 3, whether or not the length dimension of the cylindrical tube 1 and the surface roughness of the end face 4 meet preset inspection conditions. And a control device 5 as inspection means for comparing and determining whether or not.

  The cylindrical tube 1 is processed into a predetermined shape in a pre-process that is set in the inspection unit. For example, a long rod-shaped cylindrical tube material is cut into predetermined dimensions, the end surface 4 of the cut cylindrical tube 1 is cut with a cutting tool, and chamfered portions 7 a and 7 b are formed on the outer peripheral edge of the end surface 4 and the inner peripheral edge of the cylindrical hole 6. Formed. The cylindrical tube 1 processed in this way is supplied to the inspection unit via a workpiece supply unit 10 as shown in FIGS. 3 and 4, for example. In the workpiece supply unit 10, the cylindrical tube 1 is gradually moved by a feeder 11 formed of a semi-cylindrical half pipe, and is fed one by one from the feeder 11 to the feeding unit 12. The feeding unit 12 includes two upper and lower mounting units 13 and 14, and the cylindrical tube 1 fed from the tip of the feeder 11 to the lower mounting unit 13 is positioned against the restriction plate 15 and then positioned on the upper stage. It is drawn out to the placement unit 14. In the upper stage mounting portion 14, air is jetted from the air jet device 16 disposed on the side toward the cylindrical hole 6 of the cylindrical tube 1, and the bite attached to the inner peripheral surface and both end surfaces 4 of the cylindrical hole 6. The kite is blown away. Thereafter, the cylindrical tube 1 is fed out from the upper mounting portion 14 to the inspection unit, set at a predetermined position, and inspection is started. Since the feeder 11 is formed by a half pipe, the cylindrical tube 1 can be gradually moved while being aligned. That is, since the workpiece placement surface 17 of the feeder 11 is formed in an arc shape, the cylindrical tube 1 takes a stable posture at the lowest point 17a of the workpiece placement surface 17, and as shown in FIG. The cylindrical tubes 1 on the feeder 11 are aligned with almost no positional deviation in the left-right direction. The feeder 11 does not need to be a half pipe as in this embodiment as long as the workpiece placement surface 17 is formed in an arc shape.

  In the inspection unit, whether the length dimension of the cylindrical tube 1 is within a predetermined allowable range, whether the surface roughness of the end surface 4 of the cylindrical tube 1 is equal to or less than the predetermined roughness, and further, the end surface 4 Whether the size of the chamfered portions 7a and 7b formed in the above is within a predetermined allowable range is inspected. The control device 5 processes the shape data sampled by the displacement meter 3 to calculate a displacement value, and determines whether the displacement value is within a tolerance as an inspection condition inputted in advance or not. In addition to a comparison / determination circuit, a control panel and a display panel for setting inspection conditions and the like are also provided.

  The driving means 2 for rotating the cylindrical tube 1 at a fixed position includes a pair of lower rollers 20a and 20b that support two lower surfaces of the cylindrical tube 1 when the cylindrical tube 1 is set in the inspection unit, and one lower portion. A motor 21 for applying a rotational force to the roller 20a and an upper roller 22 for supporting one place on the upper surface of the cylindrical tube 1 are provided. The lower rollers 20a and 20b are disposed below the inclined guide plate 23 for guiding the cylindrical tube 1 drawn out from the feeding portion 12 to the inspection unit, and a part of the lower rollers 20a and 20b is formed in the inclined guide plate 23. Projecting upward from the portion 24. On the other hand, the upper roller 22 is located on the vertical line of the cylindrical tube 1 supported by the lower rollers 20a and 20b, and contacts the uppermost point of the cylindrical tube 1 when rotating. Both ends of the upper roller 22 are supported by holders 27, and an arm portion 28 of a lift device that moves the upper roller 22 up and down is connected to the holder 27. As described above, the cylindrical tube 1 is supported at three points by the pair of lower rollers 20a and 20b and the upper roller 22 at the time of rotation. Further, in order to securely support the cylindrical tube 1, the cylindrical tube 1 is disposed above the front end of the hole 24. A stopper plate 25 that can move up and down is disposed. This stopper plate 25 descends to a position near the hole 24 when the cylindrical tube 1 is inspected, and shields the vicinity of the front of the cylindrical tube 1 to prevent the cylindrical tube 1 from coming off from the rollers 20, 20 b and 22. .

  Therefore, the cylindrical tube 1 fed from the feeding portion 12 to the upper surface of the inclined guide plate 23 gets over the lower roller 20b on the near side, and as shown in FIGS. 1 and 3, the pair of lower rollers 20a and 20b Placed in between. Next, the upper roller 22 descends and comes into contact with the uppermost part of the cylindrical tube 1. In this way, the cylindrical tube 1 is supported by the lower rollers 20a and 20b and the upper roller 22, and the stopper plate 25 is lowered to a fixed position. Next, the lower roller 20 a is rotated by driving the motor 21, and a rotational force is applied to the cylindrical tube 1. By applying a rotational force from the cylindrical tube 1 to the other lower roller 20b and the upper roller 22, the cylindrical tube 1 can be stably rotated. In this way, the cylindrical tube 1 is. At the time of inspection, it continues to rotate at a constant speed in the direction indicated by the arrow in FIG. In FIG. 3, reference numeral 29 denotes a push-up bar for discharging the cylindrical tube 1 from between the lower rollers 20a and 20b after the inspection is completed.

  On both sides of the cylindrical tube 1 in the axial direction, a pair of displacement meters 3 for irradiating both end surfaces 4 of the cylindrical tube 1 with laser light and detecting the reflected light are arranged. The displacement meter 3 includes a light projecting unit 30 and a light receiving unit 31 on the surface facing each end surface 4 of the cylindrical tube 1, and emits laser light from the light projecting unit 30 toward the end surface 4 of the cylindrical tube 1. While irradiating, the reflected light which returns to each light receiving part 31 from each end surface 4 is detected, and the displacement of each end surface is calculated | required. Further, as shown in FIG. 2, the displacement meter 3 is installed so as to be movable in the left-right direction (A direction) and the up-down direction (B direction). The displacement meter 3 is adjusted in the left-right direction according to the length of the cylindrical tube 1 and is adjusted in the vertical direction according to the thickness of the cylindrical tube 1. Further, when inspecting the shape of the chamfered portions 7a and 7b formed on the end face 4 of the cylindrical tube 1, the displacement gauge 3 is detected while being moved in the vertical direction.

  Next, the detection principle of the displacement meter 3 will be briefly described with reference to FIG. As shown in this figure, the principle of detection of the displacement meter 3 is that a laser beam 32 emitted from a light projecting unit 30 of the displacement meter 3 is irradiated to an object to be inspected 34, and reflected light 33 returned at that time is received by a light receiving unit. 31 is detected. First, the light receiving position at the light receiving unit 31 when the inspection object 34 is inspected at the reference position P1 is defined as Q1. Next, the light receiving position at the light receiving unit 31 when the inspection object 34 is displaced from the reference position P1 to P2 is Q2. In this way, the light receiving unit 21 detects the light receiving position shifted from Q1 to Q2 by the distance b in response to the displacement of the inspection object 34 from the reference position P1 to P2. A displacement amount a of the inspection object 24 from the reference position P1 to P2 can be obtained. Then, the displacement amount a obtained here is compared with a tolerance as a preset inspection condition, and it is determined whether or not the displacement amount a is within the tolerance of the inspection condition, that is, within the allowable displacement range. Is done.

  FIG. 6 shows a case where the length dimension of the cylindrical tube 1 is inspected based on the detection principle of the displacement meter 3 described above. L1 indicates the distance between the displacement gauges 3 disposed on the left and right, and L2 indicates a preset reference length dimension of the cylindrical tube 1. The distance between each displacement meter 3 and each end face 4 of the cylindrical tube 1 is defined as l1 and l2. Each displacement meter 3 is fixed, the end surface 4 of the cylindrical tube 1 is irradiated with the laser beam 32 while rotating the cylindrical body 1 at a fixed position, and end face shape data when the cylindrical tube 1 is rotated once is sampled. To do. The position of the laser beam 32 applied to the end face 4 is not particularly limited, but is preferably near the center of the end face 4. The number of samplings is appropriate. Then, the sampled shape data is processed to calculate a displacement amount, and whether or not the displacement amount is within a preset tolerance is compared. If it is within the tolerance, the reference length dimension L2 of the cylindrical tube 1 is compared. If it is outside the tolerance, it is determined as a defective product because it is too long or too short than the reference length L2 of the cylindrical tube 1. Specifically, an average value of the length measurement is obtained from a plurality of sampled length measurement data, and it is determined whether or not the difference between the length measurement average value and the reference length dimension L2 is within a tolerance range input in advance. . In order to measure while rotating the cylindrical tube 1, the cylindrical tube 1 may be slightly displaced in the left-right direction. However, in order for the left and right displacement gauges 3 to detect the displacement as a relative displacement, This can be dealt with by providing a correction circuit that cancels the displacement.

  Further, based on the end face shape data of the cylindrical tube 1 sampled as described above, the surface roughness of the end face 4 can be inspected at the same time. That is, when the end face 4 of the cylindrical tube 1 has irregularities, they are detected as displacement amounts when measured by the displacement meter 3, so these displacement amounts are within the tolerance of the preset inspection conditions. If it is within the tolerance, it is determined that the end face 4 is smooth. Specifically, the determination is made based on a ratio (%) in which each of the plurality of length measurement data falls within a tolerance range input in advance. This ratio can be set individually in relation to the accuracy required for the product. Further, the tolerance value of the tolerance of the surface roughness can be the same range as the tolerance value of the tolerance of the length dimension or a different range depending on the accuracy required for the product. The inspection of the surface roughness of the end surface 4 does not require sampling of shape data for the entire end surface 4 of the cylindrical tube 1. As shown by the laser beam trajectory T1 in FIG. 7A, the entire tendency of the end face 4 can be found by sampling the vicinity of the center of the end face 4 of the cylindrical tube 1 once. There is virtually no problem. Needless to say, the shape data may be sampled by drawing a spiral from the inner side of the end face 4 to the outer side as indicated by the locus T2 of the laser beam in FIG.

  FIG. 8 illustrates the shape inspection of the pair of chamfered portions 7a and 7b formed on the outer peripheral edge and the inner peripheral edge of the end surface 4 of the cylindrical tube 1. FIG. In the inspection of the chamfered portion 7a at the outer periphery shown in FIG. 8, it is determined by measuring the depth dimension d of the chamfered portion 7a whether or not the predetermined angle θ of the chamfered portion 7a is accurately obtained. In this case, while the rotation of the cylindrical tube 1 is stopped, the displacement meter 3 is moved toward the outside of the cylindrical tube 1 in parallel with the end face 4, the shape data of the chamfered portion 7a is sampled, and the sampled shape data is obtained. Displacement is calculated by processing, and the amount of displacement is compared with a preset tolerance as an inspection condition. If the displacement is within the tolerance, the depth of the chamfered portion 7a is appropriate. It is determined that the predetermined angle θ is accurately output. The chamfered portions 7a and 7b are chamfered at a substantially constant angle over the entire circumference in order to form the chamfered portions 7a and 7b by cutting at a constant angle while rotating the cylindrical tube 1 by applying a cutting tool to the chucked cylindrical tube 1. Accordingly, as described above, if one place is inspected, the overall tendency of the chamfered portions 7a and 7b can be understood, so that the above inspection method is substantially free from problems. In addition, the inspection of the chamfered portion 7b on the inner peripheral edge can be performed by the same means.

  FIG. 9 shows a flowchart for inspecting the shape of the end face 4 of the cylindrical tube 1 using the above-described appearance inspection apparatus. First, the visual inspection apparatus is turned on to initialize the apparatus, and then the inspection conditions are input. The inspection conditions include a tolerance of the length of the cylindrical tube 1, a tolerance of the surface unevenness of the end face 4, a tolerance of a depth dimension of the chamfered portions 7 a and 7 b formed on the outer peripheral edge and the inner peripheral edge of the end face 4. Next, after the displacement meter 3 is moved to the inspection start position, a menu operation is performed if the inspection conditions are added or changed. The inspection start position is set, for example, at a position close to the chamfered portion 7 b in the cylindrical hole 6 of the cylindrical tube 1.

  Next, when the positioning signal of the cylindrical tube 1 is input from the sequencer, the displacement meter 3 starts to move from the inspection start position toward the center position of the end surface 4 of the cylindrical tube 1 (the position indicated by symbol S in FIG. 6). To do. At that time, the cylindrical tube 1 is positioned by the driving means 2 (the driving roller 2 and the driven rollers 12a and 12b) and the stopper plate 15 at a predetermined position of the inspection unit, but is inspected in a state where the rotation is stopped. As the displacement meter 3 moves, the shape data of the chamfered portion 7a of the cylindrical tube 1 is sampled, and the shape data is processed to calculate the displacement of the chamfered portion shape. Then, it is compared whether the displacement value is within the tolerance entered as the inspection condition. If it is within the tolerance, it proceeds to the next inspection, and if it is outside the tolerance, it is judged as a defective product and defective. The signal is output, and the position returns to the position (a) in FIG. At that time, the upper roller 22 of the inspection unit is separated from the cylindrical tube 1 based on the output of the failure signal, the stopper plate 25 is pulled up, and the cylindrical tube 1 is pushed up by the push-up rod 29 to get over the lower roller 20a, Roll down on the guide plate 23. The rolled cylindrical tube 1 is collected as a defective product.

  A rotational force is applied to the cylindrical tube 1 that has passed the inspection by the driving means 2. The displacement meter 3 samples the shape data for one round along the circumference while irradiating the substantially center position of the end face 4 of the cylindrical tube 1 rotating at a fixed position, and processes the shape data to generate irregularities on the end face 4. Calculate the displacement of the shape. Then, as described above, whether the displacement value is within the tolerance input as the inspection condition is compared, and if it is within the tolerance, the process proceeds to the next inspection, and if it is outside the tolerance, it is a defective product. It judges and outputs a defect signal and returns to the position (a) again. The determination here is performed for two items: whether the length of the cylindrical tube 1 is within a predetermined tolerance, and whether the surface roughness of the end face 4 is within a predetermined tolerance. Even if either one is within the tolerance, if the other is out, it is determined as a defective product.

  In the next inspection, the motor 21 is stopped and the rotation of the cylindrical tube 1 is stopped. In this state, the displacement meter 3 is moved outward from the center position of the end face 4 of the cylindrical tube 1 to inspect the shape of the chamfered portion 7 a formed on the outer peripheral edge of the end face 4. Similar to the chamfered portion 7b on the inner periphery, the shape data of the chamfered portion 7a is sampled, and the shape data is processed to calculate the displacement of the chamfered portion shape. Then, it compares whether the displacement value is within the tolerance entered as the inspection condition, determines whether the data is within the tolerance of the inspection condition, and outputs a good product signal if it is within the tolerance. If it is out of tolerance, a defective product signal is output. Since a series of inspections for one cylindrical tube 1 is completed in this inspection, the process returns to the position (a) in the flowchart regardless of whether the signal is a good product or a failure signal. In addition, the cylindrical tube 1 that has been inspected is separated from the upper roller 22, the stopper plate 25 is pulled up, and the lower roller 20 a is moved over by the push-up rod 29, and rolls off the inclined guide plate 23 to be non-defective. Sorted into good products.

  In addition, although said embodiment demonstrated the inspection method of the cylindrical tube 1, this invention can perform the same test | inspection also about a column-shaped workpiece | work. In the above embodiment, the shape of the chamfered portion has been described as the end surface shape, but the present invention is not limited to the chamfered portion.

It is a perspective view which shows the inspection unit of the external appearance inspection apparatus which concerns on this invention. It is a front view of the said inspection unit. 1 is a side view of an appearance inspection apparatus according to the present invention. It is a top view which shows the workpiece | work supply part of the external appearance inspection apparatus which concerns on this invention. It is explanatory drawing which shows the detection principle by the displacement meter of the external appearance inspection method which concerns on this invention. It is a conceptual diagram which shows the external appearance inspection method which concerns on this invention. It is explanatory drawing which shows the locus | trajectory of the laser beam in the end surface of a cylindrical tube. It is a conceptual diagram which shows the inspection method of the chamfering part of a cylindrical tube in the external appearance inspection method which concerns on this invention. It is a flowchart figure of the external appearance inspection method which concerns on this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Cylindrical tube 2 Drive means 3 Displacement meter 4 End surface 5 Control apparatus (inspection means)
7a, 7b Chamfered portion 11 Feeder 17 Work placement surface 20a, 20b Lower roller 22 Upper roller 25 Stopper plate 30 Light projecting portion 31 Light receiving portion 32 Laser light 33 Reflected light

Claims (13)

Laser light is irradiated along the circumferential direction to both end faces of the inspection object having a circular outer shape, and the reflected light from each end face is detected to determine the displacement of each end face, and the inspection object is based on this displacement value. An inspection method for inspecting the length dimension and the surface roughness of the end face. Laser light is irradiated along the circumferential direction to both end faces of the inspection object having a circular outer shape, and laser light is irradiated along the diameter direction to the peripheral edge portions of both end faces of the inspection object. A visual inspection method characterized by detecting the reflected light to determine the displacement of each end face, and inspecting the length dimension, the surface roughness and the end face shape of the object to be inspected based on the displacement value. 3. The appearance inspection method according to claim 1, wherein the object to be inspected is a cylindrical body or a columnar body. 3. The appearance inspection method according to claim 1, wherein laser light is irradiated to both end faces while rotating the inspection object. 3. The appearance inspection method according to claim 2, wherein the laser beam is irradiated while moving the laser beam in the diametrical direction to the peripheral portions of both end faces of the inspection object. 3. The appearance inspection method according to claim 2, wherein an end face shape of the inspection object is a shape of a chamfered portion formed at a peripheral edge portion of the end face. 3. The appearance inspection method according to claim 1, wherein the quality of the object to be inspected is determined by comparing the displacement of each end face obtained by laser light irradiation with a preset tolerance. Inspection method. Driving means for rotating the inspection object having a circular outer shape at a fixed position;
A pair of displacement meters that are arranged on both sides in the axial direction of the object to be inspected, irradiate both end faces of the object to be inspected with laser light and detect the reflected light;
An appearance inspection apparatus comprising: inspection means for inspecting the length dimension of the object to be inspected and the surface roughness of the end face based on the displacement of each end face obtained from the displacement meter. Driving means for rotating the inspection object having a circular outer shape at a fixed position;
A pair of displacement meters that are arranged on both sides in the axial direction of the object to be inspected, irradiate both end faces of the object to be inspected with laser light and detect the reflected light;
An appearance inspection apparatus comprising: inspection means for inspecting the length dimension, the surface roughness and the end surface shape of the object to be inspected based on the displacement of each end surface obtained from the displacement meter. 10. The visual inspection apparatus according to claim 8, wherein the inspection means compares the displacement of each end face obtained from the displacement meter with a preset tolerance to determine whether the inspection object is good or bad. An appearance inspection apparatus comprising a circuit. 10. The appearance inspection apparatus according to claim 9, wherein the displacement meter is installed so as to be movable in the diameter direction of the object to be inspected. 10. The appearance inspection apparatus according to claim 8, wherein the feeder for supplying the inspection object to a fixed position has an arcuate placement surface. 13. The appearance inspection apparatus according to claim 12, wherein the feeder is formed by a semi-cylindrical half pipe.

Images