JPS63274851A - Method for inspecting seamed part of can - Google Patents

Abstract

PURPOSE:To safely and rapidly inspect and measure the respective points of the seamed part of a can to be inspected by using the X-ray fluoroscopic information of the seamed part of said can. CONSTITUTION:The can 1 to be inspected is disposed between an X-ray source 10 and X-ray camera 11 and an X-ray 10a is projected on a part of the seamed part 4 of the can 1 at a prescribed angle theta of inclination with the plane of a can cap 3. The intensity of an X-ray fluoroscopic distribution is inputted as the X-ray fluoroscopic information to the camera 11 in compliance with the degree at which the body hook and cover hook in the seamed part 4 are superposed. This information is subjected to an image processing such as stressing of the contrast between brightness and darkness by an image processor 12, by which the inspection and measurement of the seamed part 4 are safely and rapidly carried out.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a method for inspecting the seamed portion of a metal can used as a canned container for food or the like.

[Prior Art] Metal cans used as containers for canned foods, etc. are made up of nine can bodies, a lid, and a can bottom. In the case of so-called three-piece cans, the can body has a can lid and a can bottom. In the case of a two-piece can in which the can body and can bottom are integrated, the can lid is wrapped around one can body to seal the can. The seaming part between the can body and the can lid (hereinafter referred to as the "can lid" including the can bottom) is connected to the podium hook formed on the edge of the can body (Fig.
BH) and a cover hook (,
CH) and are formed by engaging and press-bonding them.

The quality of this seaming part has a great effect on maintaining the quality of the contents filled in the can. In other words, Podefyri (B
Cans with a defect in the first seam closure due to the overlapping part (OL) between H) and cover hook (CH) not being long enough, etc., may be damaged due to 'P, poor sealing, spoilage of contents, etc. For this reason, it was necessary to periodically inspect the seam portion of cans that have completed the seam process and to control the process to prevent cans from being poorly seamed.

The conventional method for inspecting the seamed part of a can is to use a scroll saw to cut the seamed part in the axial direction to make the cross section inside the seamed part visible, and then conduct a visual inspection or measure the dimensions of each part. Met. In addition, such inspections and measurements are usually performed at only three locations around the entire circumference of the seaming portion, since cutting with a scroll saw requires time and effort.

[Problems to be solved] - As mentioned in E, the conventional method for inspecting the seaming part of a can involves cutting the seaming part using a scroll saw, inspecting three places, and setting one fixed point. I was doing it.

However, this cutting operation is problematic because it requires a lot of effort and there is a risk of cutting one finger.

In addition, there is a pode hook (BH) in the seaming part.

The tip of the cover hook (CH) often has irregular undulations at short intervals due to seaming. Therefore, the quality of the entire circumference of the seaming part is judged based on inspection and measurement at about three locations. Conventional methods also have the problem of lacking reliability.

The present invention was made to solve such problems, and by using X-ray fluoroscopic information of the first seam tightening part,
To provide a method for inspecting a seam seam part of a can, which can safely, quickly and easily inspect the seam seam part name points and determine I# sufficient to obtain reliable inspection results.

[Means for Solving the Problems] In order to achieve the above object, the method for inspecting the seamed part of a can according to the present invention includes disposing a can to be inspected between an xi source and an X-ray information input means, and X-rays are projected onto a part of the seaming portion at a predetermined angle of inclination with respect to the plane of the can lid. Accordingly, the X-ray fluoroscopic information of the front side of the can seaming part is input into the X-ray information input means, and the can seaming part is inspected using this X-ray fluoroscopic information.

Here, the front side of the can seaming part refers to the chuck C of the can seaming part.
Refers to wall surface or seaming wall surface.

[Example] Hereinafter, an example of the present invention will be described with reference to the drawings.

First, a design example for carrying out the method of the present invention will be described with reference to the drawings.

FIG. 1 is a configuration diagram showing an example of an apparatus, and FIG. 2 is a diagram showing a cross section and an X-ray front perspective image of a can-sealing portion.

In FIG. 1, reference numeral 1 designates a can as an object of inspection, and a seaming portion 4 for connecting a can body 2 and a can lid 3 is formed at an end in the axial direction. As shown in FIG. 2, this seaming part 4 is formed by crimping a pod hook (BH) formed on the edge of the can body 2 and a cover hook (CH) formed on the outer peripheral edge of the can lid 3. They are formed by tightly interlocking in the closed state. In order to determine the quality of the seaming portion 4, dimensional data of the podium hook (B) (), the bar hook (CH), their overlapping portion (OL), etc. are required.

10 is an X-ray source whose focal point is 0.1 to 1.0+smφ(
Normally 0.3mmφ), so-called fine focus
A wire tube is used. The X-ray energy emitted by the X-ray source IO is desirably set to a value as shown in the table below, depending on the materials of the can body 2 and can lid 3.

[Margin below]

ll is an X-ray camera as an X-ray information input means, and inputs X-ray fluoroscopy information regarding the seaming part 4. That is,
The seaming part 4 of the can l is placed between the X-ray source 10 and the X-ray camera 11, and the X-rays that have passed through the seaming part 4 are input as X-ray fluoroscopic information regarding the seaming part 4. . Here, the X-ray camera 11 is placed as close as possible to the seaming part 4 of the can 1.

Further, the seaming section 4 for one can 1 is arranged so that the front side, that is, the surface of the seaming chuck wall 4a, faces the X-ray source 1O. By the way, when the can 1 is placed in such a state that the can lid plane of the can 1 is parallel to the X-rays 10a projected from the X-ray source 10,
Two places c are located on the road x & a, then
Information obtained by fluoroscopy of these two locations will be input to the ray camera 11 in an overlapping manner, making it impossible to obtain accurate fluoroscopic information.

Therefore, the method of the present invention avoids the upper end 4b of the seaming part 4 by arranging the can l so that the can lid plane is inclined by an arbitrary angle with respect to the X-ray 10a projected from the X-ray source lO, In this embodiment, the chuck wall 4a is arranged to project X-rays directly onto the lower end 4c close to the X-ray camera 11. Generally, the chuck wall 4a has a tilt angle θ of about 4 to 8 degrees with respect to the can 142.
The can 1 is tilted by 0 (approximately 4 to 8 degrees) with respect to the X-rays 10a projected from the X-ray source 10.

As a means of setting this inclination angle, there is a means of tilting and arranging the X-ray light source lO as shown in FIG.
Any of the means of arranging it at an angle may be adopted.

Reference numeral 12 denotes an image processing device that performs image processing on the X-ray fluoroscopic information of the seaming portion 4 inputted to the X-ray camera 11 and displays a front fluoroscopic image of the seaming portion 4 on the display 13. As shown in Fig. 2, the front perspective image includes a two-dimensional image A that shows the degree of overlap of the podium hook (BH) and cover hook (CH) using contrast between black, white, and gray;
Furthermore, a one-dimensional image B is used, which is a graphical representation of the strength and weakness of the contrast in this two-dimensional image. Note that in the case of visual inspection only, it is sufficient to use only the two-dimensional image A, and in the case of only one-dimensional measurement, it is sufficient to use only the -dimensional image B.

Next, a method of inspecting a can seaming portion using the above-described apparatus will be described.

From the angle of inclination θ with respect to the can lid plane of the can 1, the seaming part 4
X-rays 10a are projected onto the front surface of the chuck wall 4a (the surface of the chuck wall 4a). Then, the X
The line camera 11 has a podium hook (
An X-ray transmission intensity distribution corresponding to the degree of overlap between the cover hook (CH) and the cover hook (CH) is input as X-ray fluoroscopy information.

This X-ray fluoroscopic information is subjected to image processing such as enhancement of brightness and darkness contrast in an image processing device 12, and is then processed on a display 13.
These are displayed as front perspective images A and B of the seaming portion 4.

Here, the first winding part 4 is as shown by ■ to Φ in FIG.
Divided into six parts. The arrangement of each of these parts will not change as long as the podey hook (B H) and cover hook (CH) are engaged, but the width of each part, for example, ) is short, and if there is any defect, the width will change depending on the content of the defect.

That is, the normal seaming part 4 is as shown in FIG.
The overlapping part (OL) of the podium hook (BH) and the cover hook (CH) maintains a sufficient length.

This overlapping area (OL) appears in the two-dimensional image A as the darkest part (■) located in the center. If the pod hook (BH) or cover hook (CH) is not properly tightened due to short length, etc.,
The width of portion 2 in the two-dimensional image A becomes narrower.

In this way, the width of each part ■ to ■ in the two-dimensional image A changes in response to the defect in the seaming part 4, so if these widths are visually inspected while comparing with the normal width, It is possible to determine whether the seaming portion 4 is good or bad.

In addition, the lengths of each part of the seaming part 4, for example, the lengths of the pod hook (BH), cover hook (CH), and overlapping part (OL), can be calculated and easily measured based on the -dimensional image B. can be calculated.

That is, Pode hook (B) = ■ + ■ + ■ Cover hook (CH) = ■ 1010 Overlapping part (OL) = ■.

Based on these measured values, it is also possible to determine the quality of the seamed portion.

In addition, it is also possible to perform such an inspection on the entire circumference of the seamed portion by rotating the can relative to the X-rays.

FIGS. 3(a) and 3(b) are block diagrams showing other examples of apparatus for carrying out the method of the present invention.

It should be noted that the same parts as those in the case shown in FIG.

The apparatus shown in FIG. 2A uses an X-ray line sensor 21 as an X-ray information input means. That is, the X-rays projected from the x11 source 10 and transmitted through the seaming part 4 are input to each element of the X-ray sensor 21 disposed close to the seaming part 4, and are converted into electric signals. Output to the processing device 22.

The signal processing device 22 processes the electrical signals sent from each sensor element to obtain one-dimensional information (information similar to one-dimensional image B in FIG. 2) corresponding to the X-ray transmission intensity distribution. Output to the output device 23.

Furthermore, if this -dimensional information is processed, the length of each part of the seaming part 4 can be determined, for example, as in the device shown in FIG.
The lengths of the pod hook (BH), cover hook (CH), and overlapping portion (OL) can be calculated.

The apparatus shown in FIG. 3(b) uses an X-ray sensor 31 as an X-ray information input means. That is, X-rays projected from the X-ray source 10 and transmitted through the seaming part 4 are input to the X-ray sensor 31 arranged close to the seaming part 4. here,
There is a pinhole (0.5mmφ) on the front side of the X-ray sensor 31.
(below) A shielding plate 34 with holes 34a is provided, so that only the X-rays that have passed through the pinholes 34a are input to the X-ray sensor 31, thereby preventing a decrease in accuracy due to diffusion of the X-rays. There is.

Moreover, in the case of this apparatus, in order to scan the entire seaming part 4, the can 1 is moved in the axial direction (in the direction of the arrow in the figure). It goes without saying that the X-ray source 10 and the X-ray sensor 31 may be moved in the direction of the arrow shown in the figure with respect to the can 1.

The X-rays input to the X-ray sensor 31 are converted into electrical signals and input to the signal processing device 32. The signal processing device 32 processes the time-series input signals to obtain one-dimensional information corresponding to the X-ray transmitted intensity distribution (one-dimensional image in FIG. 2 and one-dimensional information obtained by the device in FIG. 3(a)). information) is output to the output device 33. Then, by processing this -dimensional information, the length of each part of the seaming part 4 can be calculated, as in the device example shown above.

As described above, according to the method of the present invention carried out using the apparatuses shown in FIGS. 1, 3(a) and 3(b), the seaming portion 4
can be inspected and measured extremely quickly based on X-ray fluoroscopic information.

Therefore, the entire circumference of the seaming part 4 is inspected multiple times at short intervals, a
The results can be highly reliable.

The present invention is not limited to the embodiments described above,
For example, it also includes the following modifications.

(2) A method for inspecting the seamed portion of a can in which the inclination angle of the cross section of the can relative to X-rays is at an angle other than 4 to 8 degrees.

(2) An inspection method for can seaming parts using an X-ray camera, an X-ray line sensor, or a means other than an X-ray sensor capable of detecting an X-ray transmission intensity distribution as an xl information input means.

■ A method for inspecting a can cinching section in which a means for preventing halation occurring at the periphery of an X-ray fluoroscopic image of the cinching section is provided on the line of X-rays projected from an X-ray source. It is not necessary when the information input means is other than an X-ray camera.

■ An inspection method for can seaming parts that automatically determines whether the can seaming parts are good or bad using the obtained X-ray fluoroscopic information.

[Effects of the Invention] As described above, according to the present invention, by using X-ray fluoroscopic information of the seamed portion, inspection and measurement of each point sufficient to obtain reliable inspection results can be carried out safely and quickly. It also has the effect of being easy to carry out.

[Brief explanation of the drawing]

Claims (6)

[Claims] (1) A can to be inspected is placed between the X-ray source and the X-ray information input means, and X-rays are projected onto a part of the seamed portion of the can at a predetermined angle of inclination with respect to the plane of the can lid. By this, X-ray fluoroscopic information of the front side of the can crimping part is input into the X-ray information input means, and the can cinching part is inspected using this X-ray fluoroscopic information. Inspection method. (2) The can winding according to claim 1, wherein the inclination angle is set to 4 to 8 degrees corresponding to the angle that the chuck wall of the seaming portion makes with respect to the can body. How to inspect the tightening part. (3) The method for inspecting a can seam portion according to claim 1 or 2, wherein the X-ray source is a fine focus X-ray tube. (4) The method for inspecting a can seaming part according to claim 1, 2 or 3, wherein the X-ray information input means is an X-ray camera. (5) The method for inspecting a can seaming part according to claim 1, 2 or 3, wherein the X-ray information input means is an X-ray line sensor. (6) The method for inspecting a can seam portion according to item 1, 2 or 3, wherein the X-ray information input means is an X-ray sensor.