JP2008281497A - Inside diameter measuring device for pressed punch hole - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an inside diameter measuring device for pressed punch hole capable of measuring correctly inside diameter of pressed punch hole with face sag, without cost escalation. <P>SOLUTION: The inside diameter measuring device for pressed punch hole includes a rotating table 1 moving a work W with a through hole W1, a camera prepared at a first inspection site L1 to acquire imageries of both a luminous source irradiating light to a work plane containing one aperture of the through-bore W1 and a work plane containing another aperture of the through hole W1, a camera prepared at a second inspection site L2 to acquire imageries of both a luminous source irradiating light to a work plane containing another aperture of the through-bore W and a work plane containing one aperture of the through-bore W1, and an image processing apparatus measuring the minimum diameter in high brightness domain within imageries acquired with each camera. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an apparatus for measuring an inner diameter of a punched hole that can accurately measure the inner diameter of a through hole of a workpiece punched by a press.

In a plate-like arm vane that converts rotation of a unison ring into opening and closing of a nozzle vane with an engine turbocharger, a through hole is punched into the plate surface with a press. This press-worked hole is required to have a shape accuracy of a micron unit, and those whose inner diameter is smaller than a set value must be surely excluded as defective products. Therefore, conventionally, a pin gauge is inserted into the through-hole so that it cannot pass as a defective product. On the other hand, Patent Document 1 proposes an apparatus for optically measuring the inner diameter of a through hole formed in a workpiece.
JP2003-75130

   However, manual inspection using the conventional pin gauge is inefficient and often misses defective products. Therefore, it is conceivable to eliminate the manual inspection by optically measuring the inner diameter of the press-worked hole, but as shown in FIG. 8, in the through-hole W1 formed by punching the work W with a press, Surface sagging W5 occurs on the surface of the workpiece on the side where the punch has entered.

   Therefore, when the camera 71 is provided on the front surface side where the surface sagging W5 occurs and the light source 72 is provided on the rear surface side to measure the inner diameter of the through hole W1 (FIG. 8 (1)), the light from the light source 72 is reflected. Since it is difficult to make the light completely parallel, a part of the diffused light having an angle passes through the surface sag W5 and enters the camera 71, and the high brightness area as the light arrival area in the image is an actual through hole. There is a problem that it becomes larger than the inner diameter of W1 and the determination of quality is wrong. In this case, as shown in FIG. 8 (2), there is no problem if the workpiece W is supplied to the lower side of the camera 71 so that the surface on which the surface sag W5 is generated is always on the lower surface side. The supply device that always supplies the front and back of the apparatus with a constant structure is complicated and causes an increase in cost.

   Accordingly, the present invention solves such a problem, and can measure the inner diameter of a press-worked hole that can accurately measure the inner diameter of a press punched through hole that causes surface sagging without increasing the cost due to the complexity of the supply device. An object is to provide an apparatus.

   In order to achieve the above object, according to the first aspect of the present invention, there is provided an inner diameter measuring device for measuring an inner diameter of a through hole (W1) of a workpiece (W) punched by a press, and a movement for moving the workpiece (W). The first illuminating means (41) and the through hole provided at one position (L1) of the means (1) and the work movement path and irradiating the work surface including one opening of the through hole (W1). The first imaging means (42) for acquiring an image of the workpiece surface including the other opening of (W1) and the other opening (W1) of the through hole (W1) provided at another position (L2) of the workpiece movement path The second illuminating means (43) for irradiating the work surface with light, the second imaging means (44) for obtaining an image of the work surface including one opening of the through hole (W1), and the first imaging means (42) ), The minimum inner diameter and And a measuring means (6) for measuring the minimum inner diameter of the high luminance region in the captured image of the imaging means (44).

   In the first invention, since the image of the through hole is acquired from the front and back of the workpiece by the imaging means and the minimum inner diameter of the high luminance area in the image is measured, the smaller one of the minimum inner diameters measured on the front and back is selected. If selected, the inner diameter of the through hole can be accurately measured without being affected by surface sagging.

   In the second aspect of the present invention, the minimum inner diameter of the high luminance area in the image acquired by the first imaging means (42) and the high luminance in the image acquired by the second imaging means (44) in the workpiece movement path. Work removal means for removing the work (W) from the work movement path when at least one of the minimum inner diameters of the area is smaller than the set value is provided.

   In the second aspect of the present invention, workpieces whose inner diameters of through holes that are accurately measured without being affected by surface sag are excluded from the workpiece movement path, so that only non-defective products are reliably selected. can do.

   In addition, the code | symbol in the said parenthesis shows the correspondence with the specific means as described in embodiment mentioned later.

  As described above, according to the inside diameter measuring device for press-worked holes of the present invention, it is possible to accurately measure the inside diameter of a press punched hole that causes surface sagging without causing an increase in cost due to a complicated supply device. .

   The workpiece W which is a target of the inner diameter measuring apparatus of the present invention is, for example, the plate-like arm vane of the turbocharger described above, and an example thereof is shown in FIG. The plate-like arm vane W is an oval shape that gradually becomes wider toward one end W2, and a through hole W1 is formed by press punching at the center of the plate surface at one end.

   As shown in FIG. 2, the inner diameter measuring apparatus includes a circular turntable 1 serving as a moving means that is supported by a rotating shaft 12 and is intermittently rotated every 60 degrees by a stepping motor 11. As shown in FIG. 3, the rotary table 1 is formed with recesses 12 for receiving workpieces at intervals of 60 degrees in the circumferential direction on the outer peripheral edge thereof. The recess 12 is open to the outside, and is lower than the general portion of the turntable 1 as shown in FIG. 4, and a circular opening 121 for passing light is formed in the bottom wall. .

   The tip of the chute 2 extending from the unillustrated feeder device is close to one place on the outer peripheral surface of the turntable 1 (FIG. 3), and the recess 12 of the turntable 1 that rotates intermittently reaches the workpiece supply position K and the chute 2. When close to the tip, the workpiece W is supplied from the chute 2 into the recess 12 with the other end W3 having a small width at the head (FIG. 4). At this time, the through hole W1 of the workpiece W supplied into the recess 12 is positioned on the opening 121. A workpiece arrival sensor 31 (FIG. 4) is provided above the workpiece supply position K to detect the supply of the workpiece W into the recess 12 and to remove dust on the workpiece W supplied into the recess 12. An air ejection pipe 32 that ejects air for removal is positioned. In the present embodiment, an optical sensor is used as the workpiece arrival sensor 31.

   In FIG. 3, a position 60 degrees away from the workpiece supply position K in the clockwise direction that is the moving direction of the rotary table 1 is the first inspection position L1, and the recess 12 passes through the first inspection position L1. A light source 41 (FIG. 2) that is an illuminating unit that irradiates parallel light downward is disposed above, and a CCD camera 42 that is an imaging unit is disposed upward below.

   A position rotated 60 degrees clockwise from the first inspection position L1 is a first defective product discharge position M1 (FIG. 3). Here, an unillustrated air ejection pipe is provided, and the work W determined to be defective in the procedure described later is blown off from the inside of the recess 12 and dropped into the defective product recovery bag 51 (FIG. 2).

   The position rotated further 60 degrees clockwise from the first defective product discharge position M1 is the second inspection position L2 (FIG. 3), in which the parallel light is directed upward below the recess 12 passes. A light source 43 (FIG. 2) for irradiating is disposed, and a CCD camera 44 is provided upward in the upward direction. Each of the CCD cameras 42 and 44 is connected to an image processing device 6 (see FIG. 5) as a measuring means.

   The position rotated further 60 degrees clockwise from the second inspection position L2 is a second defective product discharge position M2 (FIG. 3), which is provided with an unillustrated air ejection pipe, which will be described later. The work W determined to be defective is blown off from the inside of the recess 12 and dropped into the defective product collection bag 52 (FIG. 2).

   A position rotated 60 degrees clockwise from the second defective product discharge position M2 is a non-defective product discharge position N (FIG. 3). Here, an unillustrated air ejection pipe is provided, and the work W determined to be non-defective in the procedure described later is blown off from the inside of the recess 12 and dropped into the non-defective container 53 (FIG. 2).

   FIG. 5 shows a work selection procedure in the inner diameter measuring apparatus. As described above, the workpiece W is aligned in the same direction by the feeder (step 101), and is supplied from the chute 2 into the recess 12 of the turntable 1 at the workpiece supply position (step 102). Here, after dust is removed by air purge (step 103), the rotary table 1 rotates to the first inspection position L1, and a region including the lower opening of the workpiece through hole W1 is photographed from below by the camera 42 (step). 104). An example of a camera image is shown in FIG. In the image, only the region R where the parallel light that has passed through the through hole W1 is incident has high luminance, and the other region S has low luminance.

   The through hole W1 formed by press punching may be elliptical as shown in FIG. 6, but the image processing apparatus 6 is known in the art as shown by the broken line in FIG. Calculate and measure by the method. If the measured minimum inner diameter d is smaller than a predetermined set value, the image processing apparatus 6 determines that the workpiece W is defective. If it is determined as a defective product, the workpiece W is discharged from the recess 12 to the defective product collection bag 51 as described above when the first defective product discharge position M1 is reached (step 105).

   Thereafter, the turntable 1 rotates to the second inspection position L2, and an area including the upper opening of the workpiece through hole W1 is photographed by the camera 44 from above (step 106). As in the previous inspection, the image processing apparatus 6 calculates and measures the minimum inner diameter d of the high luminance region R by a known method. If the measured minimum inner diameter d is smaller than a predetermined set value, the workpiece W is Judged as defective. If it is determined as a defective product, the workpiece W is discharged from the recess 12 into the defective product collection bag 52 as described above when the second defective product discharge position M2 is reached (step 107). Only the workpiece W that has not been determined to be defective at any of the inspection positions reaches the non-defective product discharge position N as a non-defective product and is dropped and accommodated in the non-defective product storage bag 53.

   Here, the depth of field of the cameras 42 and 44 is in the range of ± X (mm) with the focus at the center, and the thickness of the workpiece W (that is, the length of the through hole W1) is Y, so that 2X> Y. Set the depth of field. As a result, if the focal points of the upper and lower cameras 42 and 44 are respectively adjusted to the front and back surfaces of the workpiece W, the foreign matter W4 attached to the inner periphery of the through hole W1 as shown in FIG. Therefore, the minimum inner diameter d of the high luminance region R narrowed by the foreign matter W4 can be calculated and measured as indicated by the broken line in FIG.

   In this way, the through-hole W1 is photographed with the cameras 42 and 44 from the front and back of the workpiece W, the minimum inner diameter d is measured, and the workpiece W whose inner diameter measurement value is smaller than the set value is excluded as a defective product. Therefore, defective products can be reliably eliminated without being affected by surface sagging.

   In the above embodiment, if the minimum inner diameters of the through holes W1 measured at both inspection positions L1 and L2 are compared, and if the smaller inner diameter value is smaller than the set value, defective products are excluded, The first defective product exclusion position M1 between the first inspection position L1 and the second inspection position L2 can be abolished. Further, the defective product may be removed manually only by measuring and displaying the minimum inner diameter of the workpiece through-hole W1 at each of the inspection positions L1 and L2.

It is a top view of a workpiece | work. It is a side view showing the whole work sorting device composition. It is a top view of a turntable. It is a principal part vertical sectional view of a turntable. It is a flowchart which shows the procedure of a workpiece | work selection. It is a figure which shows a camera picked-up image. It is a figure which shows the internal diameter measurement principle of the through-hole to which the foreign material adhered to the inner periphery. It is a schematic sectional drawing which shows the internal diameter measuring apparatus of the conventional press work hole.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Rotary table (moving means), 41 ... Light source (1st illumination means), 42 ... Camera (1st imaging means), 43 ... Light source (2nd illumination means), 44 ... Camera (2nd imaging means), 6 ... image processing apparatus (measuring means), L1 ... first inspection position, W ... work, W1 ... through hole.

Claims (2)

An inner diameter measuring device for measuring an inner diameter of a through hole of a workpiece punched by a press, the moving means for moving the workpiece, and provided at one position of a workpiece moving path, and having one opening of the through hole A first illuminating means for irradiating light to the workpiece surface including the first imaging means for acquiring an image of the workpiece surface including the other opening of the through hole, and provided at another position of the workpiece movement path, A second illuminating means for irradiating light to the work surface including the other opening of the through hole; a second imaging means for acquiring an image of the work surface including the one opening of the through hole; and the first imaging means. An apparatus for measuring an inner diameter of a press-worked hole, comprising: a measuring means for measuring a minimum inner diameter of a high-luminance area in an acquired image and a minimum inner diameter of a high-luminance area in an image acquired by the second imaging means. At least one of the minimum inner diameter of the high brightness area in the image acquired by the first imaging means and the minimum inner diameter of the high brightness area in the image acquired by the second imaging means is set in the work movement path. The inner diameter measuring device for a press-worked hole according to claim 1, further comprising a workpiece removal means for removing the workpiece from the workpiece movement path when the value is smaller than the value.

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