JP2012112835A - Inspection apparatus of resin cap - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cap inspection apparatus for inspecting the external appearance of a cap by handling only the side face of the cap without supporting the top surface or under surface of the cap by a support base and imaging the cap while conveying the cap in a state of making the top surface or under surface of the cap free.SOLUTION: The cap inspection apparatus includes: suction holes 22h formed on respective pockets 5a of a star wheel 5 for supporting and conveying a plurality of resin caps 1 and capable of sucking the side faces of the resin caps 1 in vacuum; a rotary valve 30 having a fixed side member 32 and a rotation side member 34 and configured so that the fixed side member 32 and the rotation side member 34 are relatively rotated while slidingly contacting with each other and a circular-arc-like groove 36 formed on the fixed side member 32 are intermittently connected to a plurality of continuous holes 39 formed on the rotation side member 34; an illumination 50 for projecting light to the resin caps 1 conveyed by the star wheel 5 from a lower position; and an imaging apparatus 51 for receiving light projected from the illumination 50 and imaging reflected light reflected by each resin cap 1.

Description

  In the present invention, a plastic cap for sealing a mouth of a container such as a PET bottle (PET bottle) is conveyed along a circular path, and an appearance inspection is performed by imaging the resin cap with illumination and an imaging device. The present invention relates to an inspection apparatus for a resin cap.

  Conventionally, PET bottles (PET bottles), which are lightweight plastic bottles, are frequently used for filling soft drinks and the like. The mouth of the plastic bottle is sealed with a cap. With the widespread use of PET bottles, soft drink container caps are changing from aluminum caps to resin caps. Since the resin cap is manufactured by resin molding, various inspections are required for molding. In addition, characters and patterns are printed on the top of the cap. For this reason, it is necessary to inspect the appearance of the cap made of resin after it is manufactured, such as whether it is deformed, whether there is dirt generated during printing, whether foreign matter is attached, whether there is an abnormality in the wing part (called a short wing), or the like.

  2. Description of the Related Art Conventionally, a cap inspection apparatus that performs an appearance inspection by imaging a resin cap is known. In this cap inspection device, the cap is held by an inspection star wheel and conveyed along a predetermined circular orbit, and the outer appearance of the cap is imaged and inspected by illumination and an imaging device.

JP 2001-27609 A

  In the conventional cap inspection apparatus described above, the resin cap is conveyed along the circular track by the rotation of the inspection star wheel while the resin cap is held by the pocket (recess) of the inspection star wheel. In the meantime, various inspections such as the presence or absence of deformation and the presence or absence of dirt are performed. In this case, in order to supply a resin cap to the inspection star wheel, it is necessary to separately provide a star wheel on the inlet side of the inspection star wheel and to transfer the cap between the star wheels. Therefore, a guide for guiding the side of the plastic cap is provided at the delivery section between the star wheels, and a transition plate for supporting the top of the cap is provided, and the side of the cap is supported by the star wheel pocket and guide. The top plate of the cap is supported by a jumper plate, and the cap is delivered between the two star wheels.

However, as the use of PET bottles expands, the shape of resin caps has become diverse, and the number of caps with a low height (length) has also increased. Thus, when the height of the cap is lowered, the star wheel pocket and the guide interfere with each other, and there is a problem that neither the guide nor the star wheel can secure a sufficient contact surface.
In addition, in order to inspect the top surface of the cap while the cap is being transported by the inspection star wheel after the delivery of the resin cap is completed, the top surface or the bottom surface of the cap is not supported by the support base. It must be transported in the air with only the side of the cap handled and the top or bottom of the cap free.

  Therefore, the present inventors can hold a container by providing a rotating belt that engages the side surface of the container on the outer peripheral side of the star wheel in a container such as a glass bottle and pressing the container against the star wheel pocket by the belt. Therefore, an attempt was made to apply this rotating belt method to holding a resin cap. However, since the cap is thinned to reduce the weight, the cap is in a soft state that is easily deformed. As described above, when the hardness of the resin cap becomes soft, the cap may be deformed when the belt is pressed and the cap cannot be inspected, or the cap may jump out of the pocket. There is a problem.

  The present invention has been made in view of the above-described circumstances, and does not support the top surface or the bottom surface of the cap with a support base, but handles only the side surface of the cap and transports it in the air with the top surface or the bottom surface of the cap free. However, an object of the present invention is to provide a resin cap inspection apparatus that performs an appearance inspection by imaging a resin cap.

  In order to achieve the above-described object, the present invention provides a star wheel that supports a plurality of resin caps supported by a plurality of pockets provided on an outer peripheral portion and conveys them along a circular track, and is provided in each pocket of the star wheel. The side surface of the resin cap has a suction hole that can be vacuum-sucked, a fixed side member, and a rotating side member. A rotary valve configured to intermittently communicate a formed arc-shaped groove and a plurality of communication holes formed in the rotation side member; and a resin cap conveyed along a circular track by the star wheel. Illumination for projecting light from below, and an imaging device for capturing reflected light projected from the illumination and reflected by the resin cap, and each suction hole through the rotary valve The resin cap is conveyed along a circular track by the star wheel in a state where the resin cap is vacuum-adsorbed to each suction hole intermittently communicating with a vacuum source, and during the conveyance, the illumination, the imaging device, According to the present invention, the resin cap is photographed.

  According to the present invention, when the rotation side member of the rotary valve rotates while sliding on the fixed side member by the rotation of the star wheel, the communication hole formed in the rotation side member faces the arc-shaped groove formed in the fixed side member. While in this position, the negative pressure from the vacuum source is supplied to the suction hole of the star wheel pocket, and the resin cap is vacuum-sucked by the suction hole. Further, when the communication hole formed in the rotation side member deviates from the arc-shaped groove formed in the fixed side member, the negative pressure from the vacuum source is cut off and the vacuum suction of the cap by the pocket suction hole is released. In this way, the resin cap can be vacuum-sucked and transported by the suction holes formed in the star wheel pockets, so it can be transported along a circular track with the top or bottom surface of the resin cap free. During this conveyance, the top or bottom surface can be photographed by the illumination and the imaging device.

In a preferred aspect of the present invention, the illumination is a ring-shaped illumination.
According to the present invention, the ring-shaped illumination projects light from below the resin cap toward the transported resin cap, and the reflected light from the resin cap is transmitted to the imaging device via the center of the ring-shaped illumination. You can guide and shoot.

In a preferred aspect of the present invention, the optical axis of the imaging device extends to the center of the resin cap through the center of the ring-shaped illumination.
In a preferred aspect of the present invention, the top surface of the resin cap is photographed by the imaging device.

In a preferred aspect of the present invention, one or two suction holes are provided in each pocket of the star wheel.
In a preferred aspect of the present invention, when the number of the suction holes is one, the suction hole is provided in a central portion of each pocket.
According to the present invention, the cap can be held in the pocket by vacuum suction by providing one suction hole in the center of the pocket of the star wheel.

In a preferred aspect of the present invention, when there are two suction holes, the suction holes are provided on both sides of each pocket.
According to the present invention, by providing the suction holes on both sides (both sides) of the pocket of the star wheel, it becomes possible to apply the vacuum suction force to the cap from the state where the gap between the pockets is small at the time of delivery. Caps can be delivered and transported in the air by vacuum suction.

In a preferred aspect of the present invention, a star wheel is separately provided on the inlet side of the star wheel, and when the resin cap is transferred from the star wheel on the inlet side to the star wheel, the resin is made of the suction hole of the star wheel on the inlet side. The resin cap is vacuum-sucked by the suction hole of the star wheel from the state where the cap is vacuum-sucked.
According to the present invention, the resin cap is vacuum-sucked in the suction hole of the pocket of the star wheel on the inlet side and conveyed along the circular track, and is used for inspection from the star wheel on the inlet side in the transfer section (transfer section). Delivered to the star wheel. At the time of delivery, the cap is vacuum-sucked also into the suction hole of the inspection star wheel pocket from the state of being vacuum-sucked into the suction hole of the star wheel pocket on the inlet side. Immediately after the suction hole of the inspection star wheel pocket sucks the cap by vacuum, the negative pressure to the suction hole of the star wheel pocket on the inlet side is cut off, and the cap is only in the suction hole of the pocket of the inspection star wheel. It will be in the state of vacuum adsorption. As a result, the cap is transferred (transferred) from the star wheel on the inlet side to the star wheel for inspection.

  In a preferred aspect of the present invention, a transition plate for supporting the lower surface of the resin cap is provided at a portion where the resin cap is transferred from the star wheel on the inlet side to the star wheel.

The present invention has the following effects.
(1) Since the resin cap can be vacuum-sucked and conveyed by the suction holes formed in the star wheel pockets, the resin cap is conveyed along a circular track with the top or bottom surface of the resin cap free. The top or bottom surface of the cap can be photographed by the illumination and the imaging device without any obstacles or the like blocking the top or bottom surface of the cap during the transportation.
(2) Since the resin cap can be vacuum-sucked by the suction holes formed in the pockets of the star wheel, no guide is required at the transfer part for transferring the resin cap between the star wheels, and the height (length) is A low resin cap can also be stably conveyed from one star wheel to the other star wheel.
(3) Since the resin cap can be vacuum-sucked and transported by the suction holes formed in the star wheel pocket, a simple structure that does not require a belt to press the resin cap against the star wheel pocket is achieved. In addition, the cap can be conveyed in a stable state regardless of the hardness of the resin cap.

FIG. 1 is a plan view showing the overall configuration of a resin cap appearance inspection machine which is an example of a resin cap inspection apparatus according to the present invention. FIG. 2 is a view showing a delivery portion for transferring the resin cap from the scraping star wheel to the inspection star wheel 5, and is a cross-sectional view taken along the line II-II in FIG. FIG. 3 is a half cross-sectional view showing a rotary valve installed on an inspection star wheel. 4 is a cross-sectional view showing a detailed structure of a pocket of the inspection star wheel shown in FIG. FIG. 5 is an enlarged view of an essential part showing an enlarged state in which the resin cap is transferred (transferred) from the scratching star wheel to the inspection star wheel. 6 is a schematic elevation view showing a detailed structure of the inspection station shown in FIG.

Hereinafter, an embodiment of a resin cap inspection apparatus according to the present invention will be described with reference to FIGS. 1 to 6, the same or corresponding components are denoted by the same reference numerals, and redundant description is omitted.
FIG. 1 is a plan view showing the overall configuration of a resin cap appearance inspection machine which is an example of a resin cap inspection apparatus according to the present invention. As shown in FIG. 1, the appearance inspection machine for a resin cap has a chute 2 for carrying the resin cap 1 and the cap 1 received from the chute 2 and scraped into the cap 1 and held in the pocket (recess) 4a. A scratching star wheel 4 that transports the cap 1 along a circular track, and an inspection star wheel 5 that receives the cap 1 from the scratching star wheel 4 and transports the cap 1 along the circular track. Inspection stations S <b> 1 and S <b> 2 are arranged along a circular path of the inspection star wheel 5. The inspection stations S1 and S2 are provided with illumination and one or a plurality of CCD cameras.
Further, the appearance inspection machine for resin caps includes a conveyor 10 that receives the cap 1 from the inspection star wheel 5 and conveys it linearly.

In the appearance inspection machine for resin caps configured as shown in FIG. 1, the cap 1 is continuously supplied to the staring wheel 4 for scraping by a chute 2. The scraping star wheel 4 transports the cap 1 to the inspection star wheel 5 while holding the cap 1 in the pocket (recess) 4a while holding the cap 1 in the pocket (recess) 4a. While the cap 1 is being conveyed along the circular track by the inspection star wheel 5, the top surface inspection is performed at the inspection station S1 and the outer surface inspection is performed at the inspection station S2. The cap 1 is transferred from the inspection star wheel 5 to the conveyor 10 after the inspection. It is conveyed to the next process by the conveyor 10.
In the inspection stations S1 and S2, each part of the cap 1 is imaged by illumination and a CCD camera, and the presence or absence of a defect is detected from the obtained image. An air blow discharge device (not shown) and a discharge chute (not shown) are installed on the downstream side of the conveyor 10 so as to sandwich the conveyor 10, and defective products whose defects are detected by the above inspection are air blow discharge devices. It is discharged to the discharge chute by the air blow spouted from.

FIG. 2 is a view showing a delivery portion for delivering the resin cap 1 from the stir-up star wheel 4 to the inspection star wheel 5, and is a cross-sectional view taken along the line II-II in FIG. As shown in FIG. 2, the scraping star wheel 4 includes a star wheel main body 12 made of a substantially annular member attached to the lower surface of a disk-shaped support plate 11. A large number of pockets (concave portions) 4 a into which the side surfaces of the cap 1 are fitted are formed on the outer peripheral portion of the star wheel main body 12. The star wheel main body 12 is formed with a suction hole 12h that opens to the inner side surface of the pocket 4a and vacuum-sucks the cap 1. The suction holes 12h are provided corresponding to the pockets 4a, and each suction hole 12h is connected to a rotary valve (not shown) via the vacuum pipe 14. The rotary valve is connected to a vacuum pump (not shown) as a vacuum source.
With the above-described configuration, negative pressure is supplied from the vacuum source to the pocket 4a through the rotary valve, the vacuum pipe 14, and the suction hole 12h, and the cap 1 can be vacuum-sucked by the pocket 4a.

The inspection star wheel 5 includes a star wheel main body 22 made of a substantially annular member attached to the lower surface of the disk-shaped support plate 21. A large number of pockets (concave portions) 5 a into which the side surfaces of the cap 1 are fitted are formed on the outer periphery of the star wheel main body 22. The star wheel main body 22 is formed with a suction hole 22h that opens on the inner side surface of the pocket 5a and vacuum-sucks the cap 1. The suction holes 22h are provided corresponding to the pockets 5a, and each suction hole 22h is connected to a rotary valve (not shown) via a vacuum pipe 24. The rotary valve is connected to a vacuum pump (not shown) as a vacuum source.
With the above-described configuration, a negative pressure is supplied from the vacuum source to the pocket 5a through the rotary valve, the vacuum pipe 24, and the suction hole 22h, and the cap 1 can be vacuum-sucked by the pocket 5a.
As shown in FIG. 2, the apparatus frame F is provided with a jumper plate 25 for supporting the top surface of the cap 1 when the cap 1 is transferred from the scraping star wheel 4 to the inspection star wheel 5. Yes.

  Although not shown in FIG. 2, the staring wheel 4 for scraping and the staring wheel 5 for inspection include rotary valves disposed around the main shaft that rotationally drives the staring wheel 4 for scraping and the staring wheel 5 for inspection. I have. A vacuum pump is used as a vacuum source for vacuum-adsorbing the resin cap 1, and since this vacuum pump is fixedly installed, it moves from the fixed side (vacuum pump side) to the rotating side (star wheel side). A rotary valve is used to supply negative pressure.

  FIG. 3 is a half cross-sectional view showing a rotary valve installed on the inspection star wheel 5. As shown in FIG. 3, the rotary valve 30 includes a disk-shaped fixed side member 32 fixed to a fixed base 31 and a disk-shaped rotation side member 34 fixed to a cylindrical body 33. . The stationary member 32 and the rotating member 34 are disposed around the main shaft 23. The cylindrical body 33 and the main shaft 23 are connected via a key (not shown) provided on the main shaft 23, and the cylindrical body 33, the rotation side member 34, and the main shaft 23 are configured to rotate integrally. Yes.

  The fixed side member 32 and the rotation side member 34 have a sliding contact surface 35 that rotates while being in sliding contact with each other. An arcuate groove 36 is formed in the sliding contact surface 35 of the fixed side member 32, and a plurality of communication holes 39 that open at positions facing the arcuate groove 36 are formed in the same circle on the sliding contact surface 35 of the rotation side member 34. It is formed on the circumference. A communication hole 38 communicating with the arc-shaped groove 36 is formed in the fixed member 32, and the communication hole 38 is connected to a vacuum source (vacuum pump) (not shown). On the other hand, each communication hole 39 of the rotation side member 34 is connected to each adsorption hole 22h via the vacuum pipe 24 (see FIG. 2).

  The rotary valve 30 includes a thrust bearing 40 for supporting the rotation side member 34. The thrust bearing 40 is installed on the fixed base 31 to which the fixed side member 32 is fixed, and supports the cylindrical body 33 to which the rotation side member 34 is fixed. That is, the rotation side member 34 is supported by the above-described sliding contact surface 35 and is also supported by the thrust bearing 40 via the cylindrical body 33.

  According to the rotary valve 30 configured as described above, when the rotation side member 34 rotates while being in sliding contact with the fixed side member 32, the communication hole 39 formed in the rotation side member 34 is formed in the fixed side member 32. The communication hole 38 and the communication hole 39 communicate with each other while the arcuate groove 36 is opposed to the arcuate groove 36. Therefore, the negative pressure from the vacuum source communicated with the communication hole 38 is supplied to the suction hole 22h communicated with the communication hole 39, and the resin cap 1 is vacuum-sucked by the suction hole 22h. Further, when the communication hole 39 is displaced from the arc-shaped groove 36, the communication between the communication hole 38 and the communication hole 39 is cut off, the negative pressure from the vacuum source is cut off, and the vacuum suction of the cap 1 by the suction hole 22h is released. The In addition, the rotary valve installed in the staring wheel 4 for scraping has the same structure as FIG.

FIG. 4 is a cross-sectional view showing a detailed structure of the pocket 5a of the inspection star wheel 5 shown in FIG. In the example shown in FIG. 4A, one suction hole 22h for vacuum-sucking the cap 1 is formed in the central portion of the pocket 5a. In the example shown in FIG. 4B, two suction holes 22h for vacuum-sucking the cap 1 are formed slightly inside the tip portions 5te and 5te of the pocket 5a. That is, the suction holes 22h are formed on both sides of the pocket 5a.
In the example shown in FIG. 4A, the cap 1 is supported by being in contact with the front end portions 5te and 5te of the pocket 5a formed of a substantially semicircular recess, and is held by vacuum suction by the suction hole 22h.
In the example shown in FIG. 4B, the cap 1 is supported by being in contact with the front end portions 5te and 5te of the pocket 5a formed of a substantially semicircular recess, and by vacuum suction by the two suction holes 22h and 22h. Retained.
Although the detailed structure of the pocket 4a of the scratching star wheel 4 is not shown, the pocket 4a of the scratching star wheel 4 also has a type in which one suction hole 12h is formed and two suction holes 12h. There are some types.

As shown in FIGS. 4A and 4B, the suction holes 12h and 22h are provided in the pockets 4a and 5a of the star wheels 4 and 5, and the vacuum pipes 14 and 24 are connected to the pockets 4a and 5a. The cap 1 can be attracted to the pockets 4a and 5a.
In this case, as shown in FIG. 4A, the cap 1 can be held in the pocket 5a by vacuum suction by providing one suction hole 22h in the center of the pocket 5a of the inspection star wheel 5. However, as shown in FIG. 4 (b), by providing suction holes 22h on both sides (both sides) of the pocket 5a of the inspection star wheel 5, the cap 1 can be vacuumed from the state where the pocket gap is small during delivery. The suction force can be applied, and the cap 1 can be delivered and transported in the air with a stable vacuum suction force.

FIG. 5 is an enlarged view of the main part showing the state in which the resin cap 1 is transferred (transferred) from the stir-up star wheel 4 to the inspection star wheel 5.
As shown in FIG. 5, the resin cap 1 is vacuum-sucked in the pocket 4 a of the staring star wheel 4 and conveyed along a circular track, and the staring wheel 4 for scraping is transferred at the transfer part (transfer part) TP. To the star wheel 5 for inspection. At the time of delivery, the cap 1 is also vacuum-sucked to the pocket 5a of the inspection star wheel 5 from the state of being vacuum-sucked to the pocket 4a of the scraping star wheel 4. At this time, the top surface of the cap 1 is supported by the crossover plate 25 (see FIG. 2). Immediately after the pocket 5a of the inspection star wheel 5 sucks the cap 1, the negative pressure to the pocket 4a of the staring wheel 4 is cut off, and the cap 1 is vacuumed only in the pocket 5a of the inspection star wheel 5. It will be in the adsorbed state. As a result, the cap 1 is transferred (transferred) from the scraping star wheel 4 to the inspection star wheel 5.

  FIG. 6 is a schematic elevation view showing a detailed structure of the inspection station S1 shown in FIG. As shown in FIG. 6, the resin cap 1 is held by vacuum suction through the suction holes 22 h formed in the pockets 5 a of the inspection star wheel 5 and is transported along a circular track. A ring-shaped illumination 50 is disposed below the transport path of the cap 1, and a CCD camera 51 constituting the imaging device is disposed below the ring-shaped illumination 50. The optical axis 51 </ b> X of the CCD camera 51 extends through the center of the ring-shaped illumination 50 to the center of the top surface 1 a of the resin cap 1.

In the inspection station S <b> 1 configured as shown in FIG. 6, light is projected from the ring-shaped illumination 50 onto the top surface 1 a of the cap 1, and reflected light from the top surface 1 a is photographed by the CCD camera 51. An image obtained by the CCD camera 51 is processed by an image processing device (not shown) to inspect whether the top surface 1a of the cap 1 has a defect such as dirt or scratches.
As shown in FIG. 6, since the resin cap 1 can be vacuum-sucked and conveyed by the suction hole 22h formed in the pocket 5a of the inspection star wheel 5, the top surface 1a of the resin cap 1 can be freely used. It can be transported in the state. Therefore, the top surface 1a of the resin cap 1 can be imaged by the ring-shaped illumination 50 and the CCD camera 51 without any obstacles blocking the top surface 1a of the resin cap 1.

  Although the embodiment of the present invention has been described so far, the present invention is not limited to the above-described embodiment, and it is needless to say that the present invention may be implemented in various different forms within the scope of the technical idea.

DESCRIPTION OF SYMBOLS 1 Resin cap 2 Chute 4 Scraping star wheel 4a Recessed part (pocket)
5 Star wheel for inspection 5a Recess (Pocket)
5te tip portion 10 conveyor 11 support plate 12 star wheel main body 12h suction hole 21 support plate 22 star wheel main body 22h suction hole 24 vacuum piping 25 transition plate 30 rotary valve 31 fixed base 32 fixed side member 33 cylindrical body 34 rotation side member 35 sliding Contact surface 36 Arc-shaped groove 38,39 Communication hole 40 Thrust bearing 50 Ring-shaped illumination 51 CCD camera 51X Optical axis TP delivery section (transfer section)

Claims (9)

A star wheel that supports a plurality of resin caps in a plurality of pockets provided on the outer periphery and conveys them along a circular track,
An adsorption hole provided in each pocket of the star wheel, and capable of vacuum adsorption of the side surface of the resin cap;
The fixed side member and the rotation side member have a fixed side member and a rotation side member, and are rotated relative to each other while being in sliding contact with each other, whereby a plurality of arc-shaped grooves formed in the fixed side member and the rotation side member are formed. A rotary valve configured to intermittently communicate with the communication hole;
Illumination for projecting light from below onto the resin cap conveyed along the circular path by the star wheel;
An imaging device for photographing reflected light projected from the illumination and reflected by a resin cap;
Each of the suction holes is intermittently communicated with a vacuum source via the rotary valve, and the resin cap is conveyed along a circular track by the star wheel in a state in which the resin cap is vacuum-sucked to each of the suction holes. An inspection apparatus for a resin cap, wherein the resin cap is photographed by the illumination and the imaging device during the conveyance.   2. The resin cap inspection apparatus according to claim 1, wherein the illumination is a ring illumination.   3. The resin cap inspection apparatus according to claim 2, wherein an optical axis of the image pickup device extends to a center of the resin cap through a center portion of the ring-shaped illumination.   The resin cap inspection device according to claim 1, wherein the top surface of the resin cap is photographed by the imaging device.   2. The resin cap inspection apparatus according to claim 1, wherein one or two suction holes are provided in each pocket of the star wheel.   6. The resin cap inspection apparatus according to claim 5, wherein when the number of the suction holes is one, the suction hole is provided at a central portion of each pocket.   6. The resin cap inspection apparatus according to claim 5, wherein when the number of the suction holes is two, the suction holes are provided on both sides of each pocket.   A star wheel is separately provided on the inlet side of the star wheel, and when the resin cap is transferred from the star wheel on the inlet side to the star wheel, the resin cap is vacuum-sucked by the suction hole of the star wheel on the inlet side. 8. The resin cap inspection device according to claim 1, wherein the resin cap is vacuum-sucked from the state by the suction hole of the star wheel.   9. The inspection apparatus for a resin cap according to claim 8, wherein a transition plate for supporting a lower surface of the resin cap is provided at a portion where the resin cap is transferred from the star wheel on the inlet side to the star wheel.

Images