JP4481094B2 - Metal ring side edge inspection device - Google Patents

Description

  The present invention relates to an apparatus for inspecting scratches, dents, and the like generated on a side edge of an endless metal ring used for a belt of a continuously variable transmission (CVT) for automobiles.

  Conventionally, a belt for a continuously variable transmission in which a plurality of metal rings are laminated to form a laminated ring and the laminated ring is assembled and held in an element of a predetermined shape for power transmission of a continuously variable transmission such as an automobile. Is used. The metal ring may have scratches or dents on the side edges thereof during the manufacturing process, the transport process, the lamination process, and the like.

Therefore, in order to detect scratches or the like on the metal ring, a device has been proposed in which light is applied to the side edge of the metal ring, the side edge is imaged with a camera, and the metal ring is scratched by the image. (See Patent Document 1).
JP 2004-77425 A (Specifications 0012, 0016, FIGS. 3, 4, 5)

  However, when the inspection of the side edge of the metal ring is performed by the inspection method disclosed in Patent Document 1, there is an example in which the scratch or the like is not detected even though there is a portion that should be detected as a scratch or the like. It was scattered. Thus, it has been found that there are scratches and the like that cannot be detected by the conventional inspection method.

  The inventors of the present application have found that the cause is as follows. First, conventionally, a light source that irradiates concentrated light (spot light) is used as a light source for illumination, and spot light is applied from one direction toward a single-layer metal ring. On the other hand, on the inclined surface of the recess caused by a dent or the like, the light reflected by the inclined surface does not enter the camera unless there is a certain angle range with respect to the direction of light from the light source. Therefore, even if the presence of the concave portion is imaged by the camera, only about half of the concave portion appears in the image, and the other half becomes a shadow. Can occur.

  In order to eliminate the inconvenience, an object of the present invention is to provide a side edge inspection apparatus with higher accuracy than before.

In order to achieve the above object, a metal ring side edge inspection apparatus according to the present invention is an apparatus for inspecting a side edge of a metal ring formed in an endless manner, and rotating means for rotating the metal ring in a circumferential direction. Imaging means for imaging a side edge from the axial direction of the metal ring rotated by the rotation means, and the imaging position of the side edge of the metal ring by the imaging means from both sides in the circumferential direction of the metal ring. Illumination means for irradiating light inclined in the circumferential direction with respect to the axial direction of the metal ring, and image analysis means for processing the image obtained by the imaging means to inspect the side edges of the metal ring , The image analysis means selects a binarization means for binarizing the image obtained by the imaging means with a predetermined binarization threshold, and an inspection target portion corresponding to the metal ring appearing in the binarized image Selection means to A rectangular inspection window having a predetermined width in the tangential direction of the metal ring in the inspection object portion is set in the inspection object portion, and the width in the direction perpendicular to the tangential direction is set for the inspection object portion in the inspection window. A width detection means for obtaining a maximum width value by moving the inspection window while obtaining, and comparing the obtained maximum value with a predetermined determination value to determine whether the maximum value is equal to or greater than the determination value. And determining means .

  In the side edge inspection apparatus of the present invention, since the illuminating unit emits light from both sides of the imaging position, it is possible to irradiate all of the inclined surfaces of the recesses caused by dents or the like. Accordingly, since the whole of the concave portion appears in the image obtained by the image pickup means, the image analysis means can detect the image without overlooking a scratch or the like as in the prior art. In the present application, the circumferential direction is a concept including a tangential direction of the imaging position.

  Moreover, in the side edge inspection apparatus of this invention, the said illumination means has a planar light emission part which irradiates diffused light, and the said light emission part sees the said metal ring from the circumferential direction of the said metal ring seeing from the said imaging position. It preferably extends over a predetermined angular range inclined in the axial direction of the ring. The concave portion such as a dent formed on the side edge of the metal ring has various angles of the inclined surface. However, in the side edge inspection device of the present invention, the diffused light from the light emitting unit is spread over a predetermined angle at the imaging position. Since it is irradiated, the inclination of these various angles can be imaged by the imaging means. Therefore, scratches and the like can be detected without any leakage by the image analysis means.

  Next, an example of an embodiment of the side edge inspection apparatus of the present invention will be described with reference to FIGS. As shown in FIGS. 1 and 2, the side edge inspection apparatus 1 according to the present embodiment is provided with a rotary table 2, an illumination device 3 provided above the rotary table 2, and above the rotary table 2 and the illumination device 3. A provided camera 4, an image processing device 5 that processes an image captured by the camera 4, and a turntable control device 6 that controls the rotation of the turntable 2 are provided.

  As shown in FIG. 2, the turntable 2 holds a laminated ring 7 a in which a plurality of metal rings 7 are laminated in a laminated state, and rotates the laminated ring 7 a in the circumferential direction. The turntable 2 is provided with a holding portion (not shown) that contacts the inner peripheral surface of the laminated ring 7a and holds the laminated ring 7a in a circular state. Further, on the side of the turntable 2, a marking device 8 is provided that performs marking in a place where a scratch or the like is present when a scratch or the like is detected in the laminated ring 7 a. The marking device 8 has a marker 8a that can be moved forward and backward toward the laminated ring 7a.

  As shown in FIG. 2, the illuminating device 3 includes two planar light emitting units 9, a support plate 10 that supports these planar light emitting units 9, a fixing plate 11 that fixes the support plate 10 so that the angle of the support plate 10 is adjustable, An optical fiber 12 that transmits light to the planar light emitting unit 9 is included, and the optical fiber 12 is connected to a light source 13. The planar light emitting unit 9 is square as shown in FIG. 2, and in this embodiment, a 30 mm square is used. In the flat light emitting unit 9, diffused light is irradiated from the entire surface. Further, when viewed from the imaging position P of the laminated ring 7a, the planar light emitting section 9 extends from 14 ° to 84 ° from the circumferential direction of the laminated ring 7a toward the axial direction of the laminated ring 7a as shown in FIG. Exist.

  The camera 4 is a commonly used CMOS camera, and images the side edge of the laminated ring 7a, that is, the metal ring 7 from the axial direction. The camera 4 is connected to the image processing apparatus 5 by a cable 14.

  As shown in FIG. 4, the image processing apparatus 5 includes, as a functional configuration, an image storage means 15, a binarization means 16, a selection means 17, a width detection means 18, a determination means 19, a result display means 20, and a flaw position detection. Means 21. The image storage means 15 is connected to the camera 4, the result display means 20 is connected to a monitor 22 built in the image processing apparatus 5, and the flaw position detection means 21 is connected to the rotary table control apparatus 6.

  The rotary table control device 6 incorporates a marking control means 6a as shown in FIG. The marking control means 6a is connected to the marking device 8, and performs marking on the laminated ring 7a by the marking device 8 on the basis of a signal at a place where there is a flaw or the like notified from the flaw position detection means 21.

  As shown in FIG. 5, the laminated ring 7 a is obtained by laminating a plurality of (in this embodiment, 12) metal rings 7. Each metal ring 7 is laminated with an adjacent metal ring 7 with a slight gap. Further, as shown in FIG. 5, the side edge of the single-layer metal ring 7 has a substantially arc shape with chamfered corners.

  Next, the operation of the side edge inspection apparatus 1 of this embodiment will be described. Here, as shown in FIG. 5, an example will be described in which a recess 23 due to a dent is generated in the outermost metal ring 7 at the imaging position P. First, a plurality of metal rings 7 are stacked by a stacking apparatus (not shown) to form a stacked ring 7a. The stacked ring 7 a is transferred onto the rotary table 2 by a transfer device (not shown) and is held in a circular shape by a holding portion of the rotary table 2. After the laminated ring 7a is set on the turntable 2, the turntable control device 6 rotates the turntable 2 at a predetermined speed.

  At the imaging position P of the laminated ring 7a, the illuminating device 3 irradiates the diffused light of the planar light emitting unit 9 from both sides in the circumferential direction of the laminated ring 7a (in the present embodiment, the tangential direction at the imaging position P). Thus, the image of the side edge of the laminated ring 7a is taken by the camera 4 in a state where the laminated ring 7a is rotated and illuminated by the lighting device 3. Since the planar light emitting unit 9 is a planar light emitting unit as described above, the planar light emitting unit 9 also extends in the stacking direction of the stacked ring 7 a, that is, in the radial direction of the metal ring 7. For this reason, unlike conventional spot light, illumination can be performed over a wide range. Thus, the inspection can be performed even in a state where the metal ring 7 is laminated to form the laminated ring 7a.

  Since the metal ring 7 in the present embodiment is chamfered at the corners of the side edges and has a substantially arc shape in a cross-sectional view, when light is applied to the side edges of the laminated ring 7a from the circumferential direction, an image is taken. As shown in the enlarged view of FIG. 4, the vicinity of the center in the thickness direction of each metal ring 7 is bright because of the amount of light reaching the camera 4 due to reflection, and the chamfered portion has a large reflection angle and the reflected light is reflected. Since it does not reach the camera 4, it becomes a dark image.

  In such a laminated ring 7a, if there is a concave portion 23 due to a dent in the side edge of the metal ring 7, a part of the side edge of the metal ring 7 is crushed by the concave portion 23, and the crushed portion also has planar light emission. The diffused light from the unit 9 hits and the reflected light reaches the camera 4. Moreover, although the shape of the recessed part 23 is various, when this inventor etc. changed the angle of the planar light emission part 9 and the circumferential direction of the lamination | stacking ring 7a from 14 degrees to 84 degrees, not only a dent but equipment etc. Even when the side edge was damaged due to contact, such a recess 23 could be recognized by the camera 4.

  The image captured by the camera 4 is sent to the image processing device 5 via the cable 14 and stored in the image storage unit 15. In the image processing device 5, the binarization unit 16 performs binarization processing on the image stored in the image storage unit 15 by using a predetermined binarization threshold, and further performs binarization of the binarized image. . As shown in FIG. 6, the binarized and labeled image appears as a plurality of arc-shaped bright portion images 7 b in which the side edges of the metal ring 7 are gently curved, and the concave portion 23 has a shape 23 a that protrudes up and down. appear. 6 and 7, the circumferential direction of the metal ring 7 is defined as the X-axis direction, and the radial direction of the metal ring 7 is defined as the Y-axis direction. The binarized image is divided into a bright portion image 7b and a dark portion image, and the dark portion image is black. However, in FIG. 6 and FIG. 7, the dark portion image is represented by shading instead of black for convenience.

  Next, the image processing apparatus 5 selects a single-layer bright portion image 7b from among the plurality of bright portion images 7b binarized and labeled by the selection unit 17. In the present embodiment, each bright portion image 7b shown in FIG. 6 is selected in order from the top, and the selected bright portion image 7b is transmitted to the width detecting means 18.

  In the width detection means 18, an inspection window 24 having a predetermined width in the X-axis direction is applied to the bright part image 7b selected by the selection means 17, and the radial width of the bright part image 7b is set in the inspection window 24. Ask. The inspection window 24 is set to be short in the X-axis direction and long in the Y-axis direction. Then, while moving the inspection window 24 from the left to the right in the X-axis direction in FIG. 7, the width in the Y-axis direction of the bright portion image 7b in each region is obtained. For example, in the area on the left side of FIG. 7, the thickness of the bright portion image 7b itself is the width. In the substantially central region, the width of the region 23a protruding in the width direction is the width in the Y-axis direction.

  As described above, the width detection unit 18 sequentially moves the inspection window 24 in the X-axis direction, and detects the maximum value of the width of the bright portion image 7b in the Y-axis direction. In the present embodiment, the width of the bright portion image 7b is detected while moving the inspection window 24 that is short in the X-axis direction as described above, because the entire bright portion image 7b has an arc shape. This is to prevent calculation as a width.

  The maximum value of the radial width of the metal ring 7 detected by the width detection unit 18 is transmitted to the next determination unit 19. The determination means 19 compares the maximum value of the width with a predetermined determination value, and determines that the metal ring 7 is unusable when the detected maximum value of the width is equal to or greater than the determination value. The determination result is transmitted from the result display means 20 to the monitor 22 and displayed. In addition, when it is determined by the determination means 19 that the use is not possible, a signal of the position of the recess 23 is sent from the flaw position detection means 21 to the rotary table control device 6.

  In the rotary table control device 6, the rotary table 2 is rotated by a signal from the flaw position detecting means 21 to move the portion where the dents or the like of the laminated ring 7a are located to the position of the marking device 8, and the marking control means 6a uses the marker 8a. Is made to project toward the laminated ring 7a. Moreover, in this embodiment, marking is not performed for each metal ring 7, but marking is performed on the outer peripheral surface of the laminated ring 7a where a dent or the like is detected.

  Then, the laminated ring 7a whose side edge is inspected by the side edge inspection apparatus 1 of the present embodiment is paid out to the next process such as an assembling process as a normal laminated ring 7a unless there is a scratch including the recess 23 or the like. On the other hand, the laminated ring 7a in which a scratch or the like is found is inspected again by the inspector as a candidate for the unusable product, and if it is determined that the product is unusable by the inspector, the metal ring 7 having a scratch or the like The work such as removing is performed.

  Thus, in this embodiment, it can test | inspect in the state which laminated | stacked the metal ring 7. FIG. Conventionally, since a single-layer metal ring was inspected, it took a lot of time to inspect all the metal rings in a set of laminated rings. The work time can be shortened.

  In the above-described embodiment, the inspection is performed on the laminated ring 7 a in which the metal ring 7 is laminated. However, when the single-layer metal ring 7 is set on the rotary table 2, the inspection of the single-layer metal ring 7 is performed. Can also be done. Moreover, although the angle of the plane light emission part 9 is left-right symmetric in FIG. 3, it is not restricted to this, You may irradiate light from a different angle by changing either angle. Further, the marking by the marking device 8 may be performed on the entire laminated ring 7a as in the above embodiment, or only on the metal ring 7 having scratches or the like using an ink jet printer or the like facing the side edge of the laminated ring 7a. Marking may be performed. Moreover, in the said embodiment, although the CMOS camera is used as the camera 4, other cameras, such as a CCD camera, may be used.

The block diagram which shows the outline | summary of the side edge test | inspection apparatus which is an example of embodiment of this invention. Explanatory drawing which shows the structure of the principal part of the side edge inspection apparatus of this embodiment. Explanatory drawing which shows the relationship between a laminated ring, an illuminating device, and a camera. Explanatory drawing which shows the functional structure of an image processing apparatus. The partially expanded sectional view of a lamination | stacking ring. Explanatory drawing which shows the image of the side edge of the lamination | stacking ring processed by the image processing apparatus. Explanatory drawing which shows the processing condition of the side edge inspection in an image processing apparatus.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Side edge inspection apparatus, 2 ... Rotating means, 3 ... Illuminating means, 4 ... Camera (imaging means), 5 ... Image processing apparatus (image analysis means), 7 ... Metal ring.

Claims (2)

An apparatus for inspecting a side edge of an endless metal ring,
Rotating means for rotating the metal ring in the circumferential direction, imaging means for imaging a side edge from the axial direction of the metal ring rotated by the rotating means, and imaging position of the side edge of the metal ring by the imaging means Further, illumination means for irradiating light inclined in the circumferential direction with respect to the axial direction of the metal ring from both sides in the circumferential direction of the metal ring, and processing the image obtained by the imaging means, the side edge of the metal ring Image analysis means for performing inspection ,
The image analysis means includes: binarization means for binarizing the image obtained by the imaging means with a predetermined binarization threshold value; and an inspection target portion corresponding to the metal ring appearing in the binarized image. A selection means for selecting, and a rectangular inspection window having a predetermined width in the tangential direction of the metal ring in the inspection target portion is set in the inspection target portion, and the inspection target portion in the inspection window is set in the tangential direction. A width detection means for obtaining the maximum value of the width by moving the inspection window while obtaining the width in the orthogonal direction, and comparing the obtained maximum value with a predetermined determination value, the maximum value being equal to or greater than the determination value side edge inspection apparatus of the metal ring, characterized in that a determining means for determining is.   The illuminating unit has a planar light emitting unit that irradiates diffused light, and the light emitting unit has a predetermined angle range inclined from the circumferential direction of the metal ring to the axial direction of the metal ring when viewed from the imaging position. The metal ring side edge inspection device according to claim 1, wherein the side edge inspection device extends over the metal ring.

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