JP6132081B2 - Can body pinhole inspection system - Google Patents

Description

  The present invention relates to an inspection apparatus for inspecting a pinhole generated in a body portion or the like of a can body.

  In the manufacturing process of a metal can body, for example, a seamless can body (hereinafter simply referred to as a can body) made by drawing and ironing, pinholes such as holes and cracks are generated in the body portion of the can body. There is. The presence or absence of the pinhole is generally inspected by a pinhole inspection apparatus used in the inspection process of the can body.

  As shown in FIG. 7, the pinhole inspection apparatus disclosed in Patent Document 1 includes an inspection turret that holds a can body to be inspected on the right side and a can internal light detection apparatus on the left side. In addition, a piston-like sealing portion, to which a sealing ring plate that slides in contact with the sliding ring plate and seals the sliding contact surface is fixed, is provided so as to be slidable on the tip end surface of the first frame on the sliding ring plate side. . Thereby, the piston-shaped sealing portion is urged by air pressure against the sliding ring plate that rotates at a high speed at the time of pinhole inspection, the sealing effect on the sliding contact surface is enhanced, and disturbance light composed of external light, light source light, etc. Reaching the photodetector side from the sliding contact surface is prevented.

  As described above, during pinhole inspection, since the sealing ring plate is pressed against the sliding ring plate that rotates at high speed, disturbance light is normally applied to the photodetector from the sliding contact surface between the sealing ring plate and the sliding ring plate. Never reach. However, due to various factors such as some external force applied, or due to the surface condition of the sealing ring plate and the sliding ring plate, a gap is instantaneously generated between the two members, and disturbance light from the gap is generated. There was a risk of reaching the photodetector and erroneously detecting a non-defective product as a defective product.

Here, in Patent Document 2, a gap is provided between the fixed-side disk and the rotating disk, and a V-groove composed of inclined surfaces having different angles is formed on any disk surface, so that the space between the moving body and the base is formed. It is described that it is possible to suppress the incidence of stray light entering the opening of the base through the gap.
In Patent Document 3, an annular circumferential groove facing in the circumferential direction is formed on the surface of the rotating disk facing the movable plate, and the front end of the fixed disk is positioned in the circumferential groove. The section describes that the light emitted from the light source is prevented from entering the light introduction path through the space between the fixed disk and the rotating disk.

However, in Patent Document 2, although a cover-like member is attached to the peripheral edge and the inner edge of the moving body, it is assumed that a gap is provided between the stationary disk and the rotating disk. When a high-luminance light source is used to increase the detection sensitivity of holes, it is estimated that a considerable amount of stray light that diffuses between the inner surfaces of the fixed disk and the rotating disk reaches the aperture where the photodetector is located. Is done.
In addition, since the light shielding portion described in Patent Document 3 has a complicated structure in which the opposing fixed disk is fitted into the circumferential groove, it is difficult to adjust the position, and light enters the fixed disk surface. Providing a trap for returning to the direction is also disclosed in the specification, but its function and effect are not sufficiently described, and the above-described problem has not yet been sufficiently solved.

  In addition, due to the performance of the photodetector, the pinhole diameter to be inspected by a conventional can pinhole inspection apparatus is about 20 μm, and when inspecting the presence or absence of a small diameter pinhole, the pinhole enters the can body. There is a possibility that the light that enters will be weak and may not reach a detectable amount of light. Here, a method of securing a light quantity that can be detected by a photodetector using a light source having a higher luminous intensity than the conventional one can be considered, but the conventional apparatus configuration does not take sufficient measures against disturbance light, There is a risk that the incidence of false detection due to the increase will increase.

Japanese Patent No. 4715988 JP 2002-365230 A Japanese Patent No. 4230269

  In light of the above-described problems, the first object of the present invention is to effectively prevent disturbance light from reaching the photodetector side from the gap between the rotating turret and the movable plate caused by the surface state and the like. The object is to provide a pinhole inspection apparatus for cans. In addition, the second object is to achieve the first object, so that it is possible to use a light source with a high luminous intensity, it is possible to detect a pinhole with a smaller diameter, and the inspection accuracy is further improved. The object is to provide a pinhole inspection apparatus for cans.

  A pinhole inspection apparatus for a can body according to the present invention includes a rotating turret having a through hole, a can body holding member for placing the can body coaxially with the through hole, and a light source for irradiating the can body with light. A can body pinhole inspection apparatus comprising: a movable plate provided on a fixed frame side facing the rotating turret; and a photodetector for detecting light leaking into the can body, wherein the rotation Formed on the surface of the sliding contact member of the movable plate that is in sliding contact with the turret as a shielding mechanism in which a plurality of annular grooves having a rectangular cross section concentrically with the through-hole of the movable plate are closely arranged at intervals smaller than the groove width. It is characterized by that.

Moreover, the following forms can be employ | adopted for the pinhole test | inspection apparatus of the can of this invention.
1. White LED light is used as the light source.
2. The can body holding member is fixed to a support shaft of a chuck for holding the can body through a rod so as to be movable together with the chuck.

According to the pinhole inspection apparatus for a can of the present invention described above, the disturbance light that has entered from the gap between the rotating turret that rotates at high speed and the movable plate is formed in an annular shape having a rectangular cross section formed on the surface of the movable plate as a shielding mechanism. Effectively reduce the amount of light that reaches the through-hole formed in the movable plate by being attenuated or absorbed every time it reaches the groove space, and effectively prevents ambient light from reaching the photodetector side. Can do.
Further, according to the pinhole inspection apparatus for a can body of the present invention, it is possible to use a light source having a high luminous intensity, and therefore, a light source for irradiating light to the outer peripheral surface of the can body is provided. By using white LED light instead of the lamp, it is possible to detect a pinhole with a smaller diameter (about several μm) while effectively preventing disturbance light from reaching the photodetector side.
Further, by using a can holding member fixed to the support shaft of the chuck for holding the can through a rod so as to be movable, a light source for irradiating the can with no inspection turret becomes necessary. Since the degree of freedom of installation (especially the lower light source) is widened, it is possible to increase the amount of light by adding more light sources. In addition, it is possible to prevent problems that occur when the body of the can body that moves in the axial direction with respect to the rotating turret is in sliding contact with the end face of the pocket of the inspection turret, such as scratches and dents on the body of the can body. it can.

It is the schematic explaining the form which test | inspects a can body with the pinhole inspection apparatus of the can body of this invention. It is a figure which shows the test | inspection area | region of the pinhole test | inspection apparatus of the can of this invention. It is sectional drawing and the top view of the shielding mechanism in FIG. It is the elements on larger scale at the time of the sliding contact of the shielding mechanism and rotary turret of this invention. It is a figure explaining the shielding function by the shielding mechanism of this invention. It is a figure which shows the mechanism which hold | maintains the can which can be applied to this invention. It is a figure explaining the structure of the pinhole inspection apparatus of the conventional can.

An embodiment of a pinhole inspection apparatus for a can according to the present invention will be described.
FIG. 1 is a schematic diagram for explaining a mode of inspecting a can body by a pin hole inspection apparatus for a can body according to the present invention. A can body 1 supplied to a pocket 3a of an inspection turret 3 by a supply turret 2 is shown in FIG. Then, the inspection turret 3 continuously rotated in the X direction was transported to an inspection station A where an upper light source 10a and a lower light source 10b (hereinafter, both are collectively referred to as the light source 10), which will be described later, was determined. Thereafter, a procedure of sending to the next process by the sending turret 4 is shown.

FIG. 2 is a view showing an inspection area of the pinhole inspection apparatus for a can according to the present invention.
First, the pinhole inspection apparatus for a can according to the present invention includes an inspection turret 3, a rotating turret 5, a chuck 6, an upper light source 10a, and a lower light source 10b. The inspection turret 3 is a can holding member for placing the can 1 passing through the inspection station A coaxially with a through-hole 8 to be described later, and the body of the can 1 can be placed on the outer peripheral edge thereof. A plurality of pockets 3a which are concave portions are formed.
The rotating turret 5 has a plurality of through-holes 8 penetrating between both surfaces thereof, and a sponge-like opening receiving portion 7 to which the opening end of the can body 1 whose one end is open is pressed is attached to one peripheral edge of the through-hole 8. It is attached via a ring 7a.

The chuck 6 is a member that supports the bottom of the can 1 by vacuum suction, and is provided so as to be fixed to the support shaft 9 and to face the rotating turret 5. Further, the chuck 6 and the support shaft 9 can move in the axial direction with respect to the rotating turret 5 so that the opening end of the can body 1 is in close contact with the opening receiving portion 7 of the rotating turret 5 by a cam and a cam follower (not shown). In this case, the can 1 similarly moves in the axial direction so as to slide on the pocket 3a. The support shaft 9 is attached to a member fixed to the rotation shaft of the rotary turret 5 via a slide mechanism or the like (not shown), and is disposed at a position substantially opposite to the through hole 8 of the rotary turret 5.
Further, a photodetector 13 such as a high-sensitivity photomultiplier tube (photomultiplier) that detects light leaking into the can 1 and facing the rotating turret 5 is disposed inside the fixed frame 11. It is provided coaxially with the hole 8 and a through hole 21 of the movable plate 20 described later.

Further, the movable plate 20 is provided to face the rotating turret 5 and is a general term for each member including a piston member 22 having a through hole 21 in the center, a ring plate 25 and a sliding contact member 26, and has a cylindrical leg portion 23. A ring plate 25 is fixed to the top surface plate 24 of the piston member 22 comprising the top surface plate 24 with bolts, and the top surface of the ring plate 25 is smoothly slidably contacted with the rotating turret 5. A sliding contact member 26 made of a black non-glossy and relatively soft plastic with a low coefficient of friction, such as a fluorine resin soft plastic, is fixed via an opaque adhesive.
Although it is desirable to adhere the sliding contact member 26 to the ring plate 25 fixed to the top plate 24 of the piston member 22 as in this embodiment, the sliding contact member 26 is directly bonded to the top plate 24 of the piston member 22. It is also possible to do.

  Further, the leg portion 23 of the piston member 22 is fitted in a fitting guide groove formed in the fixed frame 11, and can be moved forward and backward by the piston action by air pressure. In addition, a pair of O-rings are provided on the inner and outer peripheral portions of the leg portion 23 to seal the leg portion 23 and the sliding contact portion of the fitting guide groove. With such a configuration, the movable plate 20 is urged and slidably contacted with the rotating turret 5 to seal the slidable contact surface, and disturbing light is prevented from reaching the photodetector 13 side from the slidable contact surface. doing.

Moreover, in the said form, when the can 1 hold | maintained and supported by the pocket 3a and the chuck | zipper 6 moved to the position (inspection station A) facing the photodetector 13 installed in the fixed frame 11 side, the light source 10 As shown, an upper light source 10a and a lower light source 10b for irradiating light from above and below are disposed on the body of the can 1. The light source 10a is provided with a cover 10c that prevents light from the light source from leaking outside the apparatus.
As a light source for this type of pinhole inspection, white light having a wavelength in the entire region from ultraviolet to infrared is preferable. In this embodiment, a white LED light is adopted as a light source having a high luminous intensity, and a plurality of them are arranged. Accordingly, it is possible to detect a pinhole with a smaller diameter while improving the inspection accuracy while effectively preventing disturbance light from reaching the photodetector 13 side by a shielding mechanism described later.

  When inspecting the cans 1 that are sequentially conveyed by continuous rotation, the cans 1 held in the pockets 3 a are supported by the chucks 6, and their open ends are in close contact with the opening receiving portions 7 of the rotating turret 5. It becomes a state. Thereafter, while receiving the illumination of the upper light source 10a and the lower light source 10b at the inspection station A, the can body is at a timing (detection position) at which the through hole 8 of the rotating turret 5 coincides with the through hole 21 of the movable plate 20 on the same axis. The light leaking into 1 is received by the photodetector 13, and a configuration is adopted in which the presence or absence of a pinhole is determined based on the amount of light.

  Further, in this embodiment, as shown in FIGS. 3 and 4, a plurality of annular grooves 27 (in the example shown here, 7 having a rectangular cross section) concentrically with the through hole 21 on the surface of the sliding contact member 26 of the movable plate 20. Book) is formed as a shielding mechanism. With such a configuration, the disturbance light that has entered from the gap between the rotating turret 5 and the movable plate 20 rotating at a high speed is formed in an annular shape having a rectangular cross section formed on the surface of the sliding member 26 of the movable plate as a shielding mechanism. It is effective that disturbance light reaches the photodetector 13 side by effectively reducing the amount of light that is attenuated or absorbed every time it reaches the space of the groove 27 and reaches the through hole 21 formed in the movable plate 20. Can be prevented.

  FIG. 5 is a diagram for explaining the shielding function by the shielding mechanism of the present invention. Disturbance light that enters the gap between the rotating turret 5 and the movable plate 20 from both peripheral members is irradiated from the upper light source 10a and the lower light source 10b. The direct light and the reflected light from each member of the can 1 or the pinhole inspection device, which are rays A, B, and C from the left in FIG. Here, the light ray from the left direction is used as a sample, and based on the Gaussian distribution at the time of reflection, it is verified how the light ray in the specular reflection direction that gives the strongest reflection propagates.

The light rays A to C are incident on the surface of the sliding member 26 of the movable plate 20, propagated in the central direction while repeating reflection in the gap, and reach the annular groove 27a having a rectangular cross section. When the light rays A to C reach the space of the annular groove 27a, they are attenuated or absorbed when they are repeatedly reflected many times on the wall surface of the annular groove 27a. After that, when the light rays A to C whose amount of light has decreased are propagated repeatedly toward the inner side (center side) and reach the annular groove 27b, a large number of reflections are repeatedly attenuated or attenuated as described above. Absorbed. Here, the incident angles of light rays are in the order of A>B> C, and the number of reflections is also in the order of A>B> C. In the case of the light beam B, after entering the annular groove 27a and repeatedly reflecting a plurality of times, it is returned to the entrance side of the gap and emitted outward.
Note that extraneous light incident from an angle parallel to the surface of the sliding contact member 26 of the rotating turret 5 and the movable plate 20 has a small number of reflections and is difficult to attenuate. However, since the annular groove 27a has a wider space than the gap that has been repeatedly reflected, the light rays A to C diffuse and attenuate when they reach the space of the annular groove 27a. That is, even with external light incident from a parallel angle, the amount of light can be made sufficiently low due to the above-described attenuation effect.

As described above, as can be understood from the analysis of the reflection forms of the three sample beams, according to the shielding mechanism of the present invention, by providing the plurality of annular grooves 27 on the surface of the sliding member 26 of the movable plate, Each time the light reaches the annular groove 27, the light attenuation effect is superimposed, and the extraneous light that has entered the gap can be made sufficiently low.
Furthermore, as described above, since the surfaces of the rotating turret 5 and the sliding contact member 26 are surface-treated with black non-gloss, the reflected light becomes scattered light, and the actual reflection is reflected on the surfaces of the rotating turret 5 and the sliding contact member 26. It is reasonable to understand that this scattering is repeated while being scattered in all directions. Therefore, the amount of light propagation attenuates as the annular groove 27a, the annular groove 27b,.

6A to 6C show a can holding member 3h used in place of the inspection turret 3 according to the embodiment of the present invention. 6A is a bottom view of the can body holding member 3h that holds the can body 1, FIG. 6B is a front view, and FIG. 6C is a side view.
The can body holding member 3h is a plate-like member, and a concave portion in which the can body 1 can be placed is formed on an upper portion thereof, and the support shaft 8 of the chuck 6 that holds the can body 1 is connected to the support shaft 8 via the rod 3r. It is fixed so as to be movable together with the chuck 6. Further, in order to support the vicinity of the upper end and the lower end of the body portion of the can body 1, the can body holding member 3h is attached to the plurality of rods 3r with a predetermined interval. Then, the can body holding member 3h and the chuck 6 are configured so that the rotating turret 5 holds the can body 1 while the opening end of the can body 1 is in close contact with the opening receiving portion 7 of the rotating turret 5 by a cam and a cam follower (not shown). Can move in the axial direction.
According to the above configuration, since the inspection turret 3 is not required and the degree of freedom of installation of the light source 10 (particularly the lower light source 10b) for irradiating the can body 1 is increased, the number of light sources can be increased to increase the amount of light. It becomes possible to make it. In addition, inconveniences that occur when the body portion of the can 1 moving in the axial direction with respect to the rotating turret 5 is in sliding contact with the end surface of the pocket 3a of the inspection turret 3, such as scratches, dents, etc. on the body of the can 1 Can be prevented.

表１にて示すように、角度０°となる測定タイミングでの比較例の値は570ｍＶであったが、本発明に係る実施例では98ｍＶであった。尚、可動板と回転ターレットの間隙を0.12ｍｍとしたのは減光効果をより顕著に把握するために設定したものであり、前記間隙を更に狭く設定すれば、更なる減光効果を発揮することができる。 Next, test data for confirming the dimming effect by the shielding mechanism of the present invention is shown.
The dimensions of the shielding mechanism provided on the movable plate of the present invention, that is, the sliding contact member 26 on the black non-glossy surface made of a relatively soft plastic with a low friction coefficient, for example, a fluorine resin soft plastic, are set as follows: Has been.
<Example>
Sliding member 26 Diameter: φ192mm
Through hole 21 Diameter: φ71mm
Ring groove 27a Center position diameter: φ153mm
Annular groove 27b Center position diameter: φ143mm
Annular groove 27c Center position diameter: φ133mm
Annular groove 27d Center position diameter: φ123mm
Ring groove 27e Center position diameter: φ113mm
Ring groove 27f Center position diameter: φ103mm
Ring groove 27g Center position diameter: φ93mm
Annular grooves 27a to g Width: 7.3mm
Annular grooves 27a to g Depth: 1.5mm
<Comparative example>
Except that the annular grooves 27a to 27g are not provided, the sliding member 26 similar to the embodiment is used.
<Measurement position>
The angle at which the axial center position of the can body 1 coincides with the axis of the photodetector 13 is 0 °, the angle at which the rotational position of the rotating turret 5 is advanced in the clockwise direction is +, and the angle that is delayed in the counterclockwise direction is − The detected light amount was measured by the photodetector 13 at the positions of −12 °, −6 °, 0 °, 6 °, and 12 °. Here, the positions of “−12 °” and “12 °” indicate the positions of the start point and end point where the peripheral edge of the through hole 8 of the rotating turret 5 and the peripheral edge of the through hole 21 of the movable plate 20 overlap. . The data at this time is shown in Table 1. The timing at which the measurement is performed in the pinhole inspection apparatus of the present invention is in the range of −3 ° to 3 °.
<Measurement method>
The can body 1 is held in any one of the pockets 3a of the inspection turret 3 in the pin hole inspection apparatus of the can body of the present invention, and the opening end of the can body 1 is brought into contact with the opening receiving portion 7, The rotating turret 5 is gradually rotated so that the through-holes 8 of the rotating turret 5 and the through holes 21 formed in the movable plate 20 coincide on the same axis, and then the rotating turret 5 is dimmed in a non-rotating state. Went. In order to confirm the light shielding effect of this embodiment, the air cylinder for urging the movable plate 20 is not operated, and a gap (shim amount) of 0.12 mm is set between the movable plate 20 and the rotating turret 5. The light quantity of the measurement result by the photodetector 13 is expressed in mV.

As shown in Table 1, the value of the comparative example at the measurement timing at an angle of 0 ° was 570 mV, but in the example according to the present invention, it was 98 mV. The gap between the movable plate and the rotating turret was set to 0.12 mm in order to make the dimming effect more prominent. If the gap is set narrower, further dimming effect will be exhibited. be able to.

As described above, according to the present invention, it is possible to effectively prevent disturbance light from reaching the photodetector side from the gap between the movable plate and the rotating turret caused by the surface state or the like.
In addition, since the light shielding effect of the present invention is great, it is possible to use a light source with a higher luminous intensity, and it is possible to detect a pinhole with a smaller diameter (about several μm), further improving the inspection accuracy. It is possible to provide a pinhole inspection apparatus for a can.
Furthermore, if the desired dimming effect is achieved, it is possible to set the gap between the movable plate and the rotating turret and perform the detection work in a non-contact state. In addition to preventing fatigue, it also solves problems caused by vibrations caused by friction on frictional surfaces and frictional heat caused by frictional heat, which has been regarded as a problem in the past, and greatly improves the accuracy and efficiency of pinhole detection work. Can do.

DESCRIPTION OF SYMBOLS 1 Can body 2 Supply turret 3 Inspection turret 3a Pocket 3r Rod 4 Delivery turret 5 Rotation turret 6 Chuck 9 Support shaft 10 Light source 10a, 10b Upper and lower light source 11 Fixed frame 13 Photo detector (photomultiplier tube)
20 Movable plate 22 Piston member 25 Ring plate 26 Sliding member 27a to g Annular groove

Claims (3)

A rotating turret having a through-hole penetrating through, a can holding member for placing a can body coaxially with the through-hole, a light source for irradiating light to the can body, and facing the rotating turret on the fixed frame side A can body pinhole inspection apparatus comprising: a movable plate provided; and a photodetector that detects light leaking into the can body;
As a shielding mechanism in which a plurality of rectangular grooves having a rectangular cross-section concentrically with the through-holes of the movable plate are densely arranged on the surface of the sliding member of the movable plate that is in sliding contact with the rotating turret. A pinhole inspection device for a can body characterized by being formed.   2. The can pinhole inspection apparatus according to claim 1, wherein white LED light is used as the light source.   The can body pinhole inspection apparatus according to claim 1 or 2, wherein the can body holding member is fixed to a support shaft of a chuck that holds the can body through a rod so as to be movable together with the chuck.

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