JPH0933238A - Method and apparatus for inspection of can seaming part - Google Patents

Abstract

PROBLEM TO BE SOLVED: To measure the size of cans of various materials with high efficiency by a method wherein a boundary-line generation member which has a different thickness part is installed on the passage of X-rays which pass the outside of a seaming part and a part of a seaming panel part. SOLUTION: A can 100 is arranged and positioned between a top holder 4 and a pulley 82. A guide pin at, a mask guide 2 is adjusted, and a roller is brought into contact with a seaming panel part 101d at a seaming part 101. Then, the tip part of a mask plate 3 is positioned so as to cover a part of the seaming panel part 101d. X-rays A projected from an X-ray tube 200 pass through a cutout part 40 in the can top holder 4, and they enter nearly along a normal-line direction from the inner circumferential side of the seaming part 101. Then, X-rays A' transmitted through the seaming part 101 and the mask plate 3 are captured by an X-ray camera 201, an electric signal which corresponds to their intensity distribution is sent to an image processor module 202, and the boundary line of the intensity distribution is detected.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for inspecting a can winding portion and an inspection device for inspecting a can for defects by measuring a body hook dimension, a cover hook dimension and an overlap dimension of a winding portion. .

[0002]

2. Description of the Related Art A metal can used as a container for canned foods comprises a can body, a can lid and a can bottom. And in a so-called three-piece can in which the can body, the can lid, and the can bottom are separate bodies, the can body and the can lid, the can body and the can bottom are respectively wound, and the can body and the can bottom are In a so-called two-piece can that is integrated, the can body and the can lid are wound and tightened,
The canned container is hermetically sealed.

The winding tightening portion is formed by engaging a flange portion formed on the end edge of the can body with a curl portion formed on the outer peripheral edge of the can lid and crimping them. The quality of the contents in the can is affected by the quality of the tightened portion. That is, a can having a defective winding-fastened portion such as a portion where the body hook and the cover hook are overlapped with each other does not have a sufficient length causes problems such as spoilage of the contents due to poor sealing. For this reason, in the can manufacturing process, it is necessary to regularly inspect the tightening portion to find a can that is not properly tightened.

Conventionally, the inspection method of the can winding portion of this type is as follows.
It was performed as shown in FIG. That is, the can 100 is arranged between the X-ray tube 200 and the X-ray camera 201. Then, the X-ray A is projected from the inside of the winding portion 101 of the can 100 at a predetermined angle, and the X-ray A transmitted through the winding portion 101 is photographed by the X-ray camera 201. At this time, as shown in FIG. 11, the winding tightening portion 101 has the can body 101 a and the can lid 10 a.
Since it has a structure in which 1b and 1b are meshed with each other, the X-ray absorptivity of the tightening portion 101 differs depending on the material and the number of overlapping portions. As a result, the X-ray A transmitted through the tightening portion 101
Is imaged on the X-ray camera 201 with a contrast of light and dark, and a band-shaped image with different brightness is obtained as shown in the winding image B in FIG.

Therefore, by measuring the internal dimensions of the winding image B, the presence or absence of a defect in the winding portion 101 is inspected. Specifically, the dimension BH (body hook dimension) between the boundary lines, the dimension OL (overlap dimension) between the boundary lines, and the dimension CH between the boundary lines. (Cover hook size) was measured. And in this case, each boundary line ...
Is the 3rd, 5th, 6th, and
It was decided as the eighth. Therefore,
In order to accurately measure the presence or absence of a defect in the winding portion 101, it is required to accurately detect the boundary line (1) to (3) of the winding image B.

[0006]

The aluminum cans used for beer cans and the like are monometal cans made of aluminum for both the can body and the can lid. Therefore, the tightening portion 101
The difference in the number of overlaps (thickness) of the respective parts appears as it is as the density difference of the lightness and darkness of the image, and the boundary line ~ shown in FIG. 11 can be easily detected.

On the other hand, in the steel can, the can body is made of iron and the can lid is made of aluminum. Therefore, since the materials are different, in addition to the difference in the thickness of each portion of the winding portion 101, the difference in the materials further affects the density difference of the winding image B.
That is, iron has about three times the density of aluminum and has a larger atomic number. Therefore, the degree of absorption of the X-ray A is large, and the amount of the X-ray A that is transmitted is extremely small.
As a result, when it is attempted to measure the tightening portion 101 of the steel can using the X-ray A having the strength for detecting the aluminum can, it becomes difficult to detect the boundary line of the tip 101c of the aluminum can lid 101b.

That is, the amount of X-rays A transmitted between the boundary line where the iron can body 101a having a large X-ray absorption is doubled, and the space between the iron can body 101a part which is also made of iron is 2
Since the amount of the X-ray A that passes through the boundary lines and between the overlapping lines is extremely small, the density of the image between the boundary lines and the density of the image between the boundary lines are almost the same. Because it becomes difficult to distinguish

In order to deal with such a situation, the tube voltage of the X-ray tube 200 is increased so that the X-ray A winding tightening portion 101 is provided.
It is conceivable to increase the penetrating power for. That is, for aluminum cans, the boundary line can be detected by setting the tube voltage of the X-ray tube 200 to, for example, 60 kvp, but for steel cans, the boundary line is detected at the tube voltage as described above. Difficult to detect. Therefore, the tube voltage of the X-ray tube 200 is set to, for example, 90 kvp,
By increasing the penetrating power of the X-ray A, the contrast difference between the image between the boundary lines and the image between the boundary lines becomes clear, and the boundary line can be detected.

However, such a method causes the following problems. As shown in FIG. 11, the seaming panel portion 101d between the reference boundary lines is made of aluminum having a low X-ray absorption. Therefore, as described above, when the tube voltage is increased to 90 kvp and the penetrating power of X-rays is increased, most of X-rays are generated by the seaming panel unit 10.
After passing 1d, the seaming panel portion 101d becomes indistinguishable from the outside of the boundary line (upper side of FIG. 11), the boundary line, and the space. That is, the reference boundary line that should occur in the winding image B disappears.

Using a dimension measuring program for aluminum cans,
When the internal tightening dimensions BH, CH, and OL are automatically calculated and measured, as described above, the eight boundary lines ~ are detected, and the calculation processing is performed based on these boundary lines ~.
For this reason, if the boundary line disappears as described above, the measurement cannot be performed by the dimension measuring program for aluminum cans. Therefore, when the X-ray penetrating power is increased in order to measure the steel can, it is considered necessary to create and use a dimension measuring program for steel can which can be measured based on the boundary line ~.

However, when the measurement is performed using the dimension measurement program for aluminum cans in the case of measuring aluminum cans and the dimension measurement program for steel cans in the case of measuring steel cans, each time the type of can changes, It is necessary to switch the program to perform the measurement work, which makes the measurement work troublesome.

Further, in FIG. 1, when the tube voltage of the X-ray tube 200 is increased, a large amount of X-rays are projected on the X-ray camera 201 at the outer side of the boundary line where the tightening portion 101 does not exist, and fogging due to halation occurs. Occurs. When this fogging occurs,
In the vicinity of the boundary line of the tip 101c of the can lid 101b, FIG.
A pseudo-boundary line 1 appears as indicated by the two-dot chain line 2. Therefore, when the contrast difference between the images on both sides of the pseudo boundary line 1 is larger than the contrast difference between the images on both sides of the boundary line, the pseudo boundary line 1 is mistakenly recognized as a boundary line, and based on the pseudo boundary line 1, There is a risk of measuring.

Further, when a large amount of X-rays are projected onto the X-ray camera 201 outside the boundary line where the winding-fastening portion 101 does not exist, the signal of the X-ray camera 201 becomes saturated, and this influences the tube voltage. Even if it is raised, the contrast difference between both sides of the boundary line does not clearly occur, and a situation in which a clear boundary line cannot be detected occurs.

The present invention has been made in view of the above-mentioned problems. For all cans of various materials, all the boundary lines necessary for measuring the winding tightening portion are generated, and the efficiency of highly accurate dimension measurement and measurement work is improved. It is an object of the present invention to provide a method for inspecting a can-wound portion and an inspection apparatus for the can-wound portion, which are capable of being realized.

[0016]

In order to achieve the above object, a method for inspecting a can winding portion according to the invention of claim 1 is a method for inspecting a winding portion formed on an end peripheral portion of a can. Based on the projection step of projecting the X-rays from the circumferential side substantially along the normal direction and the boundary line of the intensity distribution of the X-rays transmitted to the outer circumferential side of the fastening portion, the body hook size of the fastening portion, In a method for inspecting a can winding portion, which includes a dimension calculation step of calculating a cover hook dimension and an overlap dimension, a method for inspecting a can winding portion is provided on the X-ray path passing outside the winding portion and a part of the seaming panel portion. A method is provided in which a boundary line generating member having a different thickness portion is arranged at a position distant from the tip portion by a predetermined distance, and the reference boundary line of the intensity distribution of the X-ray is generated by the boundary line generating member.

According to the first aspect of the present invention, in the projection step, X-rays are projected from the inner peripheral side of the winding tightening portion formed on the end peripheral portion of the can along the direction substantially normal to the winding tightening portion. It
At this time, the boundary line generating member is on the inner peripheral side of the winding tightening portion and passes through the outside of the winding tightening portion and a part of the seaming panel portion.
When the boundary line generating member is arranged on the path of the wire, the X-ray directed toward the outside of the winding tightening portion and a part of the seaming panel portion of the winding tightening portion is absorbed by the boundary line generating member. At this time, since there is a different thickness portion at a position distant from the tip end portion of the boundary line generating member by a predetermined distance, the intensity of X-rays transmitted through this different thickness portion and the intensity of X-rays transmitted through other portions are different. As a result, the first reference boundary line is generated at the boundary between the different thickness portion and the other portion. Further, since the intensity of the X-rays transmitted through a part of the seaming panel portion covered by the tip of the boundary line generating member is smaller than the intensity of the X-rays directly transmitted through the seaming panel portion, The intensity of X-rays is different at the tip, and as a result,
A second reference border is generated.

On the other hand, the X-rays that do not hit the boundary line generating member and are projected directly onto the tightening portion are absorbed according to the thickness and material of the tightening portion, so that the X-rays that have passed through the tightening portion are absorbed. In the strength distribution, a plurality of boundary lines ~ corresponding to the thickness and material of the tightened portion are generated. Then, in the dimension calculation step, the body hook size, the cover hook size, and the overlap size of the winding tightening portion are calculated based on the first and second reference boundary lines and the plurality of boundary lines.

Further, at this time, the boundary line generating member is arranged on the outer peripheral side of the winding tightening portion and on the X-ray passage passing through the outside of the winding tightening portion and a part of the seaming panel portion. Then, the X-rays transmitted through the outside of the winding portion and a part of the seaming panel portion of the winding portion are absorbed by the boundary line generating member, and similarly, the first and second boundary lines are generated. Note that X
When the strength of the line is low, it is possible to obtain the same number of boundary lines as the above boundary lines by eliminating the boundary line generation member.

According to a second aspect of the present invention, in the method for inspecting a can wound portion according to the first aspect, the intensity of the X-ray is increased by the different thickness portion of the tip of the boundary line generating member and the groove having a substantially V-shaped cross section. This is a method of generating the reference boundary line of the distribution.

According to the second aspect of the present invention, since a groove having a substantially V-shaped cross section is formed in the width direction of the mask plate, a linear first reference boundary line corresponding to the groove is generated. To do.

According to a third aspect of the present invention, there is provided an apparatus for inspecting a can winding portion, wherein an X-ray is emitted from an inner peripheral side of the winding portion formed on an end peripheral portion of the can, along an approximately normal direction. A boundary having an X-ray source for projection and a path of the X-ray passing through the outside of the winding tightening portion and a part of the seaming panel portion and having a different thickness portion at a position separated from the tip portion by a predetermined distance. Based on a line generation member, an X-ray camera that captures X-rays transmitted to the outer peripheral side of the fastening portion, and a boundary line of the intensity distribution of X-rays captured by the X-ray camera, the fastening portion. The size calculation device for calculating the body hook size, the cover hook size, and the overlap size is provided.

According to the third aspect of the present invention, when the X-ray is projected from the X-ray source to the winding-fastening portion formed on the end circumferential portion of the can, from the inner circumferential side thereof along substantially the normal direction. The first reference boundary line of the strength distribution is generated at the boundary between the different thickness portion and the other portion of the boundary line generation member arranged on the inner peripheral side or the outer peripheral side of the winding tightening portion. Further, a second reference boundary line is generated with the tip of the boundary line generating member as a boundary. On the other hand, in the intensity distribution of the X-ray that does not hit the boundary line generation member and directly passes through the tightened portion, a plurality of boundary lines ~ corresponding to the thickness and material of the wound portion are generated. Then, the X-ray transmitted through the winding tightening portion and the boundary line generating member is captured by the X-ray camera, and in the dimension calculation device, the first and second reference boundary lines, and the plurality of boundary lines ~. The body hook size, the cover hook size, and the overlap size of the winding tightening portion are calculated based on the above.

According to a fourth aspect of the present invention, in the inspection device for a can winding portion according to the third aspect, the boundary line generating member is a plate-shaped mask plate whose width direction is parallel to the tangential direction of the winding portion. And a groove having a substantially V-shaped cross section formed by engraving the different thickness portion in the width direction of the mask plate.

According to the present invention, the first reference boundary line is generated by the groove having a substantially V-shaped cross section formed in the width direction of the mask plate.

[0026]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a configuration diagram showing a can winding portion inspection device according to an embodiment of the present invention. In addition, regarding the same elements as the elements of FIGS. 10 to 12,
The description will be given with the same reference numerals. The inspection device of the present embodiment is
A can positioning device 1 for positioning the can 100;
An X-ray tube 200 as a radiation source, an X-ray camera 201,
An image calculation processing device 202 as a size calculation device and a monitor 203 are provided, and the can positioning device 1 has a structure in which a mask guide 2 (two-dot chain line) holding a mask plate 3 is specially provided. It should be noted that this inspection apparatus is also an apparatus capable of achieving the projection step and the dimension calculation step in the method for inspecting the canned portion of the present invention.

The can positioning device 1 includes a can top holder 4 which holds a can head of a can 100, a rotary shaft 80 which is held by a bearing 81 and holds the center of the can bottom while pressing the can bottom, and a rotary shaft 80. A pulley 82 integrally attached, a belt 83 wound around the pulley 82, a pulley 85 around which the belt 83 is wound and rotated by a motor 84, and support rollers 90 and 91 for supporting a can body of a can 100. have.

The can top holder 4 is fixed, and has a disc shape as shown in FIG. 7 when viewed from the left in FIG. A cutout 40 for passing the X-ray A is formed in the upper half portion thereof. In addition, on the front surface of the can top holder 4 (the left surface in FIG. 1), the rotating can 100
Cam followers 41 to 43 capable of supporting the winding tightening portion 101
Is attached.

As shown in FIGS. 1 and 2, the mask guide 2 is attached to the lower front portion of the can top holder 4 having the above structure. As shown in FIG. 3, the mask guide 2 has rollers 20 and 21 on both sides of the front surface, and a U-shaped mask plate mounting portion 23 for mounting the mask plate 3 is recessed in the upper portion thereof. It is set up.

The mask plate 3 is, as shown in FIG.
It is a rectangular plate-like body, and has a screw hole 30 on the base side and a groove 31 on the tip side. For example, the total length of the mask plate 3 is 10 mm, the total width is 6 mm, and the thickness is 0.5 m.
m. Further, as shown in FIG. 6, the groove 31 is engraved in the width direction of the mask plate 3, and its cross section is substantially V-shaped. The distance m between the groove 31 and the tip portion 32 is set to 1 mm, the cutting angle θ of the groove 31 is 15 degrees, and the depth h thereof is set to 0.25 mm. That is, the total thickness of the mask plate 3 is 0.5 mm, but the groove 31 is 0.25 mm, which is a half of the thickness, and the X-ray absorptivity is high between the groove 31 and other portions. It is set to be different.

The mask plate 3 having such a structure is attached to the mask plate attaching portion 23 as shown in FIG. That is, the screw 34 is tightened with the base of the mask plate 3 in contact with the bottom of the mask plate attachment portion 23 via the spring washer 33. As a result, as shown in FIG.
Extends horizontally to the front side of the mask guide 2 in a state in which it faces upward.

The mask guide 2 to which the mask plate 3 is attached in this manner is attached to the can top holder 4 as shown in FIG. That is, the mask guide 2 is attached to the lower portion of the can top holder 4 by the guide pin 44 so that the rollers 20 and 21 face the winding tightening portion 101 side, and the winding spring 1 is fixed by the coil spring 45.
It is biased to the 01 side.

On the other hand, in FIG. 1, the X-ray tube 200 is
This is for projecting the X-ray A from the inner peripheral side of the canned portion 101 of the can 100 substantially along the normal direction, and its tube voltage can be changed. Specifically, the X-ray tube 200 is attached above the can top holder 4, and the X-ray A is projected through the cutout portion 40 of the can top holder 4 onto the inner peripheral side of the winding tightening portion 101. . Further, the X-ray camera 201 captures the X-ray A ′ that has been transmitted to the outer peripheral side of the winding portion 101, converts the intensity distribution of the X-ray A ′ into an electric signal, and sends the electric signal to the image processing unit 202. Is.

The image processing apparatus 202 is an X-ray camera 201.
A boundary line of the intensity distribution is detected based on the electric signal from B.
This is a device for calculating the respective dimensions of CH and OL, and an aluminum can size measuring program is stored in the image calculation processing device 202 as this calculation processing program. Monitor 2
03 is based on the electric signal from the X-ray camera 201,
A device for displaying the contrast forming each boundary.

Next, a method of inspecting the can winding portion using the inspection apparatus of this embodiment will be described. When measuring the can 100 of the steel can, as shown in FIG.
The can 100 is arranged between the can top holder 4 and the pulley 82 with the can head of 0 facing the can top holder 4 side of the can positioning device 1 and the can bottom facing the pulley 82 side. Then, the center of the bottom of the can 100 is pressed by the rotary shaft 80 to position the can 100 and adjust the guide pin 44 (see FIG. 2) of the mask guide 2 to wind the rollers 20 and 21. The seaming panel portion 101d of the tightening portion 101 is brought into contact with. As a result, as shown in FIG. 8, the tip portion 32 of the mask plate 3 partially covers the seaming panel portion 101d of the tightening portion 101.
Will be located so as to cover from the inner peripheral side.

In this state, the tube voltage of the X-ray tube 200 shown in FIG.
Project line A. Then, the X-ray A passes through the cutout portion 40 of the can top holder 4 and reaches the winding fastening portion 101 from the inner peripheral side of the winding fastening portion 101 substantially along the normal direction, as shown in FIGS. 1 and 9. Incident (projection process).

At this time, since the can 100 is a steel can whose can body 101a is iron and whose can lid 101b is aluminum as shown in FIG. 8, the X-ray A having a high tube voltage of 90 kvp is used for the tightening portion 101. If it is directly incident on, the inconvenience as in the conventional method for inspecting the canned portion will occur. However, in the inspection device of the present embodiment, the mask plate 3 reaches the vicinity from the outside D of the seaming panel portion 101d, and the tip portion 32 of the mask plate 3 reaches the seaming panel portion 1 of the tightening portion 101.
Since it is positioned so as to cover a part of 01d, the X-ray A passing through a part of the seaming panel part 101d and the outside D is absorbed by the mask plate 3.

Specifically, as shown in FIG. 8, the X-ray A incident on the mask plate 3 is largely absorbed by the groove 31. Since the groove 31 is formed in a substantially V shape and the depth thereof is set to half the thickness of the mask plate 3, the X-ray A incident on the groove 31 is absorbed by the portion other than the groove 31. Linearly transmitted X-ray A that is absorbed with half the absorption
′ Moves toward the X-ray camera 201 side. Further, it passes near the tip 32 of the mask plate 3, and the seaming panel 1
The X-ray A directly incident on 01d is the seaming panel unit 1
Since 01d is aluminum, it is transmitted through the seaming panel portion 101d with almost no absorption. Then, the X-ray A incident on the other portion is absorbed according to the thickness of the iron can body 101a, becomes an X-ray A ', and travels toward the X-ray camera 201 side.

The X-ray A ′ thus transmitted through the tightening portion 101 and the mask plate 3 is captured by the X-ray camera 201, converted into an electric signal corresponding to its intensity distribution, and the image arithmetic processing apparatus. Sent to 202. Then, in the image processing apparatus 202, the boundary line of the intensity distribution is detected based on the electric signal from the X-ray camera 201,
BH, CH, and OL of the tightening portion 101 are calculated from this boundary line by the dimension measuring program for aluminum cans (dimension calculating step).

At this time, as described above, the intensity of the X-ray A'transmitted through the mask plate 3 is weak, the intensity of the linear X-ray A'transmitted through the groove 31 is stronger than that, and the intensity of the mask plate 3 is increased. Since the intensity of the X-ray A ′ that has passed through the vicinity of the tip portion 32 and has passed through the seaming panel portion 101d is extremely strong, as shown in the winding image B ′ in FIG. A corresponding reference boundary line is generated and a reference boundary line corresponding to the tip portion 32 is generated. Further, since most of the X-ray A directed toward the outside D of the winding portion 101 is absorbed by the mask plate 3, fogging due to halation unlike the conventional inspection method hardly occurs, and the X-ray tube 200 of the X-ray tube 200 is not generated. Depending on the tube voltage,
Clear boundaries are generated.

As a result, the image processing unit 202 can accurately recognize the boundary lines (1) to (3), and BH, CH, and OL of the tightening portion 101 are calculated from these boundary lines by the dimension measuring program for aluminum cans. can do. That is, the image calculation processing device 202 recognizes the boundary line with reference to the boundary line and calculates the distance between the boundary lines to obtain the BH dimension. In addition, the image calculation processing device 202 changes from the clear boundary line to the boundary line
The CH dimension and the OL dimension are obtained by calculating the distance between the boundary lines and the distance between the boundary lines. Also, the monitor 20
In No. 3, based on the electric signal from the X-ray camera 201,
The contrast between the border lines is displayed.

Such an inspection is performed on the entire winding tightening portion 101. That is, by rotating the pulley 85 with the motor 84, the pulley 82 is rotated through the belt 83, and the can 100 is rotated at a predetermined angle at any time,
The above measurement is performed.

When measuring the can 100 of an aluminum can,
The tube voltage of the X-ray tube 200 is changed to, for example, 60 kvp, and the mask guide 2 is removed from the can top holder 4.
As a result, as in the conventional case, a clear boundary line can be obtained, and BH and C of the tightening portion 101 can be determined by the dimension measuring program for the aluminum can of the image processing unit 202.
The dimensions of H and OL can be calculated accurately.

As described above, according to the inspection device for a can winding portion according to the present embodiment, regardless of whether the tube voltage of the X-ray tube 200 is high or low, 8 required for the calculation processing of the dimension measuring program for aluminum cans. Since the boundary lines (1) to (3) of the book can be clearly generated, the dimension measuring program for aluminum cans can be used as it is in the inspection of steel cans. As a result, it is not necessary to switch the program to perform the measurement work each time the type of the can 100 changes, and the efficiency of the measurement work can be improved.

Further, when the tube voltage of the X-ray tube 200 is increased, most of the X-rays A directed to the outside D of the winding portion 101 are absorbed by the mask plate 3, so that the conventional inspection method is used. Almost no fogging occurs due to halation. As a result, erroneous recognition due to the similar boundary line can be prevented, and highly accurate inspection can be performed even on the steel can.

Further, since most of the X-ray A directed to the outside D of the winding portion 101 is absorbed by the mask plate 3,
The image density difference of the X-ray camera 201 becomes small. Therefore, the sensitivity of the X-ray camera 201 can be increased without saturating the signal, so that the density resolution is improved, and as a result, the contrast at the tip of the can lid 101b is increased and the boundary line is easily detected. be able to.

The present invention is not limited to the above embodiment, and various forms can be applied within the scope of the gist of the invention. For example, in the above embodiment,
Mask plate 3 has a total length of 10 mm and a total width of 6 mm
And the thickness is set to 0.5 mm, and the distance m between the groove 31 and the tip 32 of the mask plate 3 is set to 1 mm,
Moreover, the cutting angle θ of the groove 31 is 15 degrees, and the depth h is
Was set to 0.25 mm, but is not limited to this, and depending on the tube voltage of the X-ray tube 200,
It goes without saying that the above numerical values are set.

Further, in the measuring operation of the can 100 of the aluminum can, the mask guide 2 is removed from the can top holder 4, but the invention is not limited to this, and the guide pin 44 has a screw structure and the mask guide 2 is used. The mask plate 3 may be separated from the tightening portion 101 by moving the mask plate 3 toward the can top holder 4 side.

Further, in this embodiment, the mask plate 3
Is arranged on the inner peripheral side of the winding tightening portion 101,
1 outer peripheral side, that is, the tightening portion 101 and the X-ray camera 2
It is needless to say that the same effects as those of the above-described embodiment can be obtained by disposing it between 01 and 01.

[0050]

As described above, according to the present invention, a predetermined number of boundary lines necessary for calculating the body hook size, the cover hook size and the overlap size of the winding tightening portion are clarified regardless of the intensity of X-rays. Therefore, even in the inspection of cans made of different materials, the above dimension calculation can be performed by one type of dimension measurement program, and as a result, the efficiency of the measurement work can be improved. .

When the X-ray intensity is increased, the boundary line generating member disposed on the inner or outer circumference side of the winding tightening portion is used to prevent the outside of the winding tightening portion and the seaming panel portion. Since X-rays directed to or transmitted through the part are absorbed, fogging due to halation unlike in conventional inspection methods hardly occurs, and as a result, erroneous recognition due to similar boundary lines can be prevented and highly accurate measurement can be performed. It can be performed.

Further, since most of the X-rays that have passed outward from or passed through the winding portion are absorbed by the boundary line generating member, the image density difference of the X-ray camera becomes small. For this reason,
Since the sensitivity of the X-ray camera can be increased without saturating the signal, the density resolution of the X-ray camera is improved,
As a result, the boundary line can be easily detected.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing a can winding portion inspection device according to an embodiment of the present invention.

FIG. 2 is an enlarged view showing a mounting state of a mask guide.

FIG. 3 is a front view of a mask guide.

FIG. 4 is a plan view of a mask guide.

FIG. 5 is a plan view of a mask plate.

FIG. 6 is a side view of a mask plate.

FIG. 7 is a front view showing a can top holder.

FIG. 8 is an explanatory diagram showing a function of a mask plate and a boundary line.

FIG. 9 is a schematic view showing the arrangement of a mask plate with respect to a winding tightening portion.

FIG. 10 is a schematic view showing a conventional method for inspecting a can winding portion.

11 is an explanatory diagram showing a generation state of a boundary line by the inspection method of FIG.

FIG. 12 is an explanatory diagram showing a state of occurrence of a similar boundary line.

[Explanation of symbols]

 1 Can Positioning Device 2 Mask Guide 3 Mask Plate 4 Can Top Holder 31 Groove 32 Tip Part 100 Can 101 Clamping Part 200 X-ray Tube 201 X-ray Camera 202 Image Processing Unit 203 Monitor A X-ray

Claims (4)

[Claims] 1. A projection step of projecting X-rays from an inner peripheral side of the can to the winding-fastened portion formed on an end circumferential portion of the can along a direction substantially normal to the winding-fastened portion, and an outer circumferential side of the winding-fastened portion. A method for inspecting a can winding portion, comprising: a dimension calculation step of calculating a body hook dimension, a cover hook dimension and an overlap dimension of the winding fastening portion based on the boundary line of the intensity distribution of the transmitted X-rays, A boundary line generating member having a different thickness portion is provided at a position separated from the tip end portion by a predetermined distance on the path of the X-ray passing through the outside of the winding portion and a part of the seaming panel portion. A method for inspecting a canned portion, characterized in that a reference boundary line of the X-ray intensity distribution is generated by a generation member. 2. The inspection of the can winding portion according to claim 1, wherein a reference boundary line of the intensity distribution of the X-ray is generated by a tip portion of the boundary line generating member and a different thickness portion of a groove having a substantially V-shaped cross section. Method. 3. An X-ray source for projecting X-rays from the inner peripheral side of the can around the end of the can, and the outside of the end of the can. And a boundary line generating member disposed on the path of the X-ray passing through a part of the seaming panel portion and having a different thickness portion at a position separated by a predetermined distance from the tip portion, and transmitted to the outer peripheral side of the winding tightening portion. Calculate the body hook size, cover hook size, and overlap size of the tightening part based on the boundary line of the X-ray intensity distribution captured by the X-ray camera and the X-ray camera An apparatus for inspecting a canned part, which comprises: 4. The boundary line generating member is formed of a plate-shaped mask plate whose width direction is parallel to the tangential direction of the winding portion, and the different thickness portion is engraved in the width direction of the mask plate. The can winding portion inspection device according to claim 3, wherein the inspection device is formed by a groove having a substantially V-shaped cross section.