JP3042395B2 - Can bottom chuck - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a continuous rotary empty can for inspecting defects such as pinholes and cracks generated in a two-piece can such as a drawn ironing can or a thinned drawn can by light and judging the quality of the can. BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a can bottom chuck for a photodetector (light tester), and more particularly, to a can bottom chuck capable of improving the inspection accuracy of the bottom of a can and speeding up the inspection.

[0002]

2. Description of the Related Art Conventionally, beer, carbonated beverages, etc.
Two-piece cans manufactured by drawing and ironing, so-called DI (Drawn & Ironing) cans, have been used. This drawing and ironing method has the characteristic that the wall thickness of the can can be reduced and the can body can be raised. The DI can manufactured by this method can be used for canned beer and carbonated beverages having a high internal pressure. It was suitable for.

[0003] However, in the draw ironing, although the wall thickness of the can can be reduced, there is a problem that defects such as pinholes and cracks are more likely to occur in the can body and the bottom of the can than in other can making methods. was there.

Therefore, in the conventional drawing and ironing, in order to efficiently detect a defective product having a pinhole or the like at the time of making the can, the can in the middle of the can is irradiated with light to inspect the presence or absence of the pinhole or the like. A rotary type empty can continuous light detector for distinguishing non-defective products from non-defective products has been used.

As a typical example of the rotary-type empty can continuous light detector, Japanese Patent Publication No. 62-550 proposed by the present applicant has been proposed.
No. 96 has a rotary type empty can continuous light detector. Hereinafter, the rotary empty can continuous light detector will be described with reference to FIGS. FIG. 5 is a sectional view showing a schematic configuration of the rotary type empty can continuous photodetector,
FIG. 6 is a sectional view showing a can bottom chuck of the rotary type empty can continuous photodetector.

In FIG. 5, reference numeral 101 denotes a drive shaft, both sides of which are rotatably supported by a left frame 102 and a right frame 103. A star wheel 110 that is continuously rotated by the drive shaft 101 is attached to the left frame 102 side of the drive shaft 101. The star wheel 110 has a plurality of can receivers 111 that support and transport the can 100. Is formed. Above and below the can seat 111, a light 10 for irradiating the entire can 100 with light is provided.
4,105 are provided.

A photodetector 120 corresponding to each can 100 conveyed by the star wheel 110 is attached to the left frame 102. This photodetector 12
6 is housed in a dark box 121 as shown in FIG. 6, and an optical seal disk 122 for sealing the opening of the can 100 is attached to the opening of the dark box 121.

[0008] Further, as shown in FIG.
, A pusher holder wheel 130 adjacent to the star wheel 110 is attached. The pusher holder wheel 130 is provided with a slide pusher 131 that can slide back and forth in the axial direction of the drive shaft 101.

Here, a can bottom chuck 140 is attached to the tip of the slide pusher 131 as shown in FIG. The can bottom chuck 140 includes a transparent pusher face 141 that transmits light from the lights 104 and 105 and a reflector 142 that reflects light transmitted through the transparent pusher face 141 to the bottom of the can 100.
And a fixing screw 14 on the surface of the transparent pusher face 141.
3, an annular transparent rubber 144 elastically contacting the bottom end rim of the can 100, a set bolt 146 having the transparent pusher face 141 fixed to the base 145 and having a vacuum hole 146 a formed therein. The configuration was provided with a ventilation path 147 communicating with the vacuum hole 146 a of the set bolt 146, and a vacuum pump 148 connected to the ventilation path 147 and adsorbing the can 100 via the set bolt 146.

Next, the inspection operation of the conventional rotary type empty can continuous photodetector having the above configuration will be described.

[0011] A star wheel 11 is supplied from a supply port (not shown).
The can 100 transported by 0 is adsorbed by the can bottom chuck 140 and transported to the photodetector 120 side.
During this transport, when the slide pusher 131 advances little by little and reaches the front of the photodetector 120, the can 100
Is brought into close contact with the light seal disk 122.

The light from the lights 104 and 105 is directly applied to the can body of the can 100 set on the light seal ring 122, and the transparent pusher face 141 and the annular Light from the lights 104 and 105 is indirectly irradiated via the transparent rubber 144 and the reflection plate 142.

If there is a pinhole or the like in the can body or bottom of the can 100, the light passing through the pinhole or the like is detected by the photodetector 120 and is determined as a defective product. If there is no pinhole or the like in the can 100, the photodetector 120 does not operate and is determined as a non-defective product.

[0014]

In the case of cans manufactured by the conventional drawing and ironing, pinholes are hardly generated in the can bottom because the wall thickness of the can bottom is large. Therefore, in the above-mentioned rotary empty can continuous light detector disclosed in Japanese Patent Publication No. 62-55096, a pinhole at the bottom of the can was not required to be as accurate as the pinhole at the can body.

However, in recent years, in order to reduce the weight and cost of the can, drawing and ironing has been performed using a material having a higher strength and a thinner thickness. Further, the production of two-piece cans by thinning and deep drawing using a higher-strength and thinner material and reducing the wall thickness of the can bottom has also been put to practical use.

When drawing and ironing using such a high-strength thin sheet material or deep-drawing with thinning is carried out,
Pinholes as fine as pinholes generated in the can body are likely to be formed in the bottom of the can, and there is a need to improve the inspection accuracy of pinholes in the can bottom. On the other hand, in order to meet the needs of mass production of products, it was necessary to increase the efficiency and speed of can making.

Therefore, at present, in the quality inspection of two-piece cans such as drawn ironed cans and thinned drawn cans, it is desired to improve the inspection accuracy of not only the can body but also the can bottom and to perform the inspection at a higher speed. ing.

However, since the transparent pusher face 141 is formed of plastic in the can bottom chuck 140 in the conventional rotary empty can continuous light detector described above, the transparent pusher face 141 and the reflection plate 142 are bonded with an adhesive. Then, the transparent pusher face 14
Because the adhesive surface of No. 1 melts and the light reflectance decreases,
They could not be glued together with an adhesive.

Therefore, the transparent pusher face 141 and the reflection plate 142 are connected to the base 14 by the set bolt 146.
5 and the thickness of the transparent pusher face 141 needs to be increased in order to obtain a strength that can withstand the pressing force of the set bolt 146. As a result, the transmittance of the transparent pusher face 141 is reduced, the light indirectly applied to the can bottom of the can 100 is attenuated, and fine pinholes formed on the can bottom of the can 100 are accurately detected. There was a limit.

The transparent pusher face 141 made of plastic is easily scratched on its surface.
This also contributed to lowering the transmittance. further,
When the transmittance was significantly reduced due to the scratch, the transparent pusher face 141 had to be replaced.

Due to such a decrease in the transmittance of the transparent pusher face 141, when the conventional can bottom chuck 140 is used, the diameter of the can 100 at the bottom of the can is about 140 μm.
Only about m pinholes could be detected.

The conventional can bottom chuck 1 described above
In No. 40, since the chucking of the can 100 was performed only by the vacuum of the vacuum pump 148, it took some time until the can 100 was sucked, and it was difficult to cope with an increase in the speed of can making.

Further, when the can 100 is chucked only by the vacuum, the attraction force of the can 100 is weak, and the can 100 cannot be reliably attracted when speeding up the can making.

Further, if only vacuum is used, can 10
When the can 100 cannot be accurately positioned and the can 100 is not accurately positioned, the can 100 cannot be set on the optical seal disk 122 or the can 100 may be jammed. .

The present invention has been made in view of the above circumstances, and has been made to improve the light transmittance of a pusher face, and
It is an object of the present invention to provide a can bottom chuck capable of improving inspection accuracy and speeding up inspection by quickly and surely adsorbing and positioning a can.

[0026]

In order to achieve the above object, a can bottom chuck according to claim 1 is an empty can continuous light detector for detecting defects such as pinholes by irradiating the can with light from a light. In the can bottom chuck in the, formed of hard glass that transmits light from the light,
A pusher face in contact with the can bottom of the can, a reflection portion located on the back of the pusher face and reflecting light from the light transmitted through the pusher face to the can bottom of the can, and a vacuum hole therein. It is provided with: a set bolt that penetrates through the pusher face and the reflecting portion and is fixed to the base; a ventilation path communicating with a vacuum hole of the set bolt; and an intake unit connected to the ventilation path, Adjust the diameter and thickness of the pusher face
The light transmitted through the pusher face and applied to the center of the can bottom of the can is indirectly reflected from the light reflected by the reflector.
The configuration is such that the dimensions are such that only typical light is obtained.

According to such a bottom chuck, since the pusher face is made of hard glass, the light transmittance is improved. In particular, hard glass (push
(Reflection part)
The emitted light reaches the bottom of the can with a short optical path length . As a result, attenuation of light irradiating the bottom of the can is reduced, resulting in strong irradiation, and pinhole detection accuracy can be improved.

Further, the surface of the pusher face is less likely to be scratched, and a decrease in the transmittance of the pusher face due to the scratches can be prevented. Further, since the pusher face is not easily damaged, it can be used without replacing the pusher face for a long period of time.

[0029] The can bottom chuck according to the second aspect is configured such that the pusher face and the reflecting portion are joined by an adhesive. With such a configuration, it is not necessary to screw the pusher face to the base, and the pusher face can be reliably thinned . Thereby, the transmittance of light from the light can be significantly improved.

As a result, the accuracy of detecting pinholes at the bottom of the can can be improved, and fine pinholes generated at the bottom of the can can be detected.

A third aspect of the present invention is a can bottom chuck in which the pusher face is fixed to a base with a set bolt via a holding ring. With such a configuration, the pusher face can be attached and detached, and replacement can be facilitated.

[0032] The can bottom chuck according to claim 4 is configured such that a magnet corresponding to the shape of the can bottom of the can is provided. With such a configuration, the can bottom of the can can be attracted by both the vacuum of the suction means and the magnetic force of the magnet, and the attraction force of the can can be increased.

Further, since the suction of the vacuum is performed in a state where the bottom of the can and the pusher face are brought into close contact with each other by the magnet, the suction of the vacuum can be efficiently performed in a short time.

Furthermore, the can can be accurately positioned by making the magnet correspond to the shape of the can bottom of the can. Thus, the can and the positioning of the can can be performed quickly and reliably, and the inspection can be speeded up.

According to a fifth aspect of the present invention, the can bottom chuck has a configuration in which a flange for protecting the peripheral portion is provided on the peripheral portion of the pusher face. With this configuration,
Even if the can jams and collides with the peripheral edge of the pusher face, the flange can prevent the pusher face from being damaged.

[0036]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a can bottom chuck according to the present invention will be described below with reference to the drawings. First, the can bottom chuck according to the first embodiment of the present invention will be described. FIG. 1 is a perspective view showing a can bottom chuck according to the first embodiment of the present invention. FIG. 2 is a sectional view showing the can bottom chuck. In the embodiment described below, the same parts as those in the related art are described.
The same numbers are assigned and the detailed description is omitted.

In these drawings, reference numeral 40 denotes a can bottom chuck according to the present embodiment. This can bottom chuck 4
0 is mainly the glass pusher face 41 and the reflection part 4
2. Magnet 43, flange 44, base 45, set bolt 46, ventilation path 47, and suction means 48 such as a vacuum pump.
And is attached to the tip of the slide pusher 131.

The glass pusher face 41 is a can 100
The bottom end has a disk shape larger than the peripheral rim, and a through hole for a set bolt 46 is formed in the center. Further, such a glass pusher face 41 is formed of hard glass having high transparency.

In FIG. 2, the reflecting portion 42 is adhered to the back surface of the glass pusher face 41 with a transparent adhesive. The glass pusher face 41 of this reflection part 42
Is a reflecting mirror surface, and is configured to effectively reflect light transmitted through the glass pusher face 41.

Since the reflecting portion 42 is fixed to the base 45 and the air passage 47 by the set bolt 46, the thickness of the bottom portion of the reflecting portion 42 is increased in order to have strength enough to withstand the fastening of the set bolt 46. I have.

It is preferable that such a reflection portion 42 be formed of a metal which is not easily magnetized in consideration of the fact that a reflection mirror surface having a higher reflectance can be formed and that the magnet 43 described below is embedded. Therefore, the reflection part 4
It is preferable to use, for example, stainless steel or the like as the material 2.

The magnet 43 is buried on the back side of the peripheral portion of the reflector 42 projecting like a flange.
Is not damaged. The magnet 43 is provided so as to correspond to the peripheral shape of the bottom end rim of the can 100. For example, as shown in FIG. 1, a plurality of magnets are provided intermittently on a circumferential line corresponding to the peripheral shape of the bottom end rim of the can 100. Further, a single ring-shaped magnet having substantially the same diameter as the peripheral shape of the bottom end rim of the can 100 may be embedded.

When the thickness of the peripheral portion of the reflecting portion 42 protruding in a flange shape is reduced, or when the reflecting portion 42 is formed by evaporating aluminum on the back surface of the glass pusher face 41, the reflecting portion 42 is formed. The magnet 43 is arranged on the back side of the peripheral edge of the above.

Glass pusher face 41, reflector 42
The flange 44 is connected to the set bolt 4 via the base 45.
6 fixed to the ventilation path 47. In addition, a vacuum hole 46 a communicating with the air passage 47 is formed inside the set bolt 46. Further, a vacuum pump 4 for sucking air from the vacuum hole 46a is provided in the ventilation path 47.
8 is connected.

In this embodiment, the vacuum hole 46 is used.
a, the set bolt 4
The filter 49 is attached to the insertion hole 6. By providing such a filter 49, clogging of the ventilation path 47 can be prevented, and maintenance of the can bottom chuck 40 can be easily performed by cleaning or replacing the filter 49.

Next, the inspection operation of the can using the bottom chuck of the present embodiment having the above configuration will be described with reference to FIG. The can bottom chuck of the present embodiment is provided in the same apparatus as the conventional rotary empty can continuous light detector shown in FIG.

The can 100 conveyed by a star wheel from a supply port (not shown) is
3 attracts onto the glass pusher face 41. As a result, the center axis of the can 100 is positioned at a position coinciding with the center axis of the light seal ring 122.

At the same time as the magnet 43 attracts the can 100, the vacuum pump 48 is also moved from the vacuum hole 46 a to the can 10.
Aspirate the bottom of the can. Then, the can 100 is conveyed to the photodetector 120 side while being attracted by the magnet 43 and the vacuum pump 48.

During this transfer, the slide pusher 131 advances little by little, and when the can 100 reaches the front of the photodetector 120, the can bottom chuck 40 closes the opening of the can 100 to the light seal disk 122. Let it.

As described above, the light from the lights 104 and 105 is directly applied to the can body of the can 100 set on the light seal disk 122, and the glass pusher face 41 is provided on the bottom of the can 100. In addition, the light from the lights 104 and 105 is indirectly irradiated via the reflection unit 42.

At this time, if there is a pinhole or the like in the can body or bottom of the can 100, light passing through the pinhole or the like is detected by the photodetector 120, and is determined as a defective product. If there is no pinhole or the like in the can 100, the photodetector 120 does not operate and is determined as a non-defective product.

Thereafter, the can 1 is separated by separating means (not shown).
00 is separated from the glass pusher face 41, and a defective unit is discharged from the line by a discharge unit (not shown).

According to such a can bottom chuck of the present embodiment, the pusher face is formed of hard glass, so that the glass pusher face 41 can be bonded to the reflecting portion 42 with an adhesive. Thereby, the glass pusher face 41 can be reduced in thickness, and the transmittance of light from the lights 104 and 105 can be improved.

The thinner glass pusher face 41
The dimensions are specifically as follows. That is,
The radius R and thickness T of the glass pusher face 41 are
Through the pusher face 41 and inside the can bottom of the can 100
Light 1 irradiated to central part O but reflected by reflector 51
The dimensions are such that only indirect light from the light source 04 (for example, light indicated by A in FIG. 4) is present.

Here, the conditions of the radius R and the thickness T of the glass pusher face 41 are such that the light applied to the central portion O of the can bottom is only the indirect light reflected from the reflecting portion 51. , Tan (R / (T + H)) ≧ tan (R ₀ / H). Here, R: radius of the glass pusher face R ₀ : ground radius of the can bottom T: height of the glass pusher face H: height of the can bottom

According to the can bottom chuck of this embodiment having such a configuration, the light passes through the glass pusher face 41 , is reflected by the reflecting portion 51, and is irradiated on the central portion O of the can bottom. Since the optical path of the light from the light is shortened, attenuation of the light applied to the bottom of the can is reduced, resulting in strong irradiation, and pinhole detection accuracy can be improved.

Further, since the glass pusher face 41 made of hard glass is hardly damaged, it is possible to prevent a decrease in transmittance due to the scratch. Furthermore, since it is hard to be damaged, the can bottom chuck 40 can be used for a long period of time without replacing the glass pusher face 41.

By improving the transmittance of the glass pusher face 41, the inspection accuracy of the pinhole at the bottom of the can 100 can be improved, and finer pinholes can be detected.

As a result of an experiment conducted by the present inventor, the conventional can bottom chuck 140 has a diameter of about 1
While only a pinhole of about 40 μm could be detected, the can bottom chuck 40 of the present embodiment could detect a fine pinhole having a diameter of about 20 μm.

[0060] Incidentally, as in this embodiment, configured for protecting the periphery of the glass pusher face 41 by the flange portion 44
In this case, even if the can 100 jams and collides with the peripheral edge of the glass pusher face 41, the breakage of the glass pusher face 41 can be prevented by the flange 44.

The flange 44 is made of a glass pusher face 41.
And a side wall that covers the peripheral portion of the reflecting portion 42, and the reflecting portion 4
2 and the same as the center part (storing part of set bolt 46)
And a bottom portion having a hole with a diameter.
It is fitted on the glass pusher face 41 side. this
The collar portion 44 must be one that can withstand the collision of the can 100
However, for example, it is formed of carbon steel.

On the other hand, since the magnet 43 corresponding to the shape of the bottom end rim of the can 100 is embedded inside the reflecting portion 42, the can 100 can be held by both the vacuum of the vacuum pump 48 and the magnetic force of the magnet 43. Adsorption can be performed, and the adsorption power of the can 100 can be increased.

Since the vacuum is suctioned after the bottom of the can 100 is brought into close contact with the glass pusher face 41 by the magnet 43, the suction of the vacuum can be efficiently performed in a short time. Further, by arranging the magnet 43 according to the circumferential shape of the bottom end rim of the can 100, the can 100 can be accurately positioned.

As a result, the suction and positioning of the can 100 can be performed quickly and reliably, and the inspection can be speeded up.

Next, a can bottom chuck according to a second embodiment of the present invention will be described. FIG. 3 is a partial sectional view of a can bottom chuck according to a second embodiment of the present invention.

In the figure, reference numeral 51 denotes a reflecting portion, which is formed integrally with the glass pusher face 41 by depositing aluminum on the back surface of the glass pusher face 41. Reference numeral 52 denotes a front end block for attaching the glass pusher face 41 (and the reflecting portion 51). A storage portion 52a for the set bolt 46 is formed in the center of the tip block 52.
In order to have a strength that can withstand the fastening, the thickness of the bottom portion is increased. A magnet 43 is embedded in the flange-shaped peripheral portion of the end block 52 so as to be located on the back side of the reflecting portion 51.

Reference numeral 53 denotes a press ring, which is fitted into the storage section 52a of the end block 52 through the insertion hole 41a of the glass pusher face 41. When the holding ring 53 is fastened to the tip block 52 by the set bolt 46, the periphery of the insertion hole 41 a of the glass pusher face 41 is pressed by the projection 53 a, and the glass pusher face 41 is fixed to the tip block 52.

According to the can bottom chuck of the present embodiment having such a configuration, the number of components can be reduced by integrating the glass pusher face 41 and the reflecting portion 51. Since the reflecting portion 51 can be easily attached to and detached from the main body by the set bolt 46, the replacement of the glass pusher face 41 is facilitated.

[0069]

As described above, according to the can bottom chuck of the present invention, it is possible to quickly and surely adsorb and position the can while improving the light transmittance of the pusher face while having a simple structure. As a result, it is possible to realize an improvement in inspection accuracy and an increase in inspection speed, which are required in recent drawing and ironing.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a can bottom chuck according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view of the can bottom chuck shown in FIG.

FIG. 3 is a partial sectional view showing a can bottom chuck according to a second embodiment of the present invention.

FIG. 4 illustrates an optical path of indirect light and a can according to an embodiment of the present invention.
Diagram showing the relationship between the glass pusher face of Tom Chuck
It is.

FIG. 5 is a cross-sectional view showing a schematic configuration of a conventional rotary-type empty can continuous photodetector.

FIG. 6 is a sectional view showing a can bottom chuck of the rotary empty can continuous light detector of FIG. 5;

[Explanation of symbols]

 40 Can bottom chuck 41 Glass pusher face 42 Reflector 43 Magnet 44 Flange 45 Base 46 Set bolt 46a Vacuum hole 47 Ventilation path 48 Vacuum pump 49 Filter

Claims (5)

(57) [Claims] 1. A can bottom chuck in an empty can continuous light detector for irradiating light to a can from a light to detect a defect such as a pinhole, wherein the can is formed of hard glass that transmits light from the light. A pusher face in contact with the bottom of the can, a reflecting portion located on the back of the pusher face and reflecting light from the light transmitted through the pusher face to the bottom of the can, and a vacuum hole formed therein. A set bolt that penetrates through the pusher face and the reflecting portion and is fixed to the base, a ventilation path communicating with a vacuum hole of the set bolt, and an intake unit connected to the ventilation path. Determine the diameter and thickness of the pusher face
A bottom portion of the can having a size such that light transmitted through the surface and irradiated to the center of the bottom of the can is only indirect light from the light reflected by the reflecting portion . 2. The can bottom chuck according to claim 1, wherein the pusher face and the reflecting portion are joined by an adhesive. 3. The can bottom chuck according to claim 1, wherein the pusher face is fixed to the base with a set bolt via a holding ring. 4. The can bottom chuck according to claim 1, wherein said reflecting portion is provided with a magnet corresponding to a shape of a can bottom of said can. 5. The pusher face according to claim 1, wherein a flange is provided on a peripheral portion of the pusher face to protect the peripheral portion.
The can bottom chuck described.