JPS63274853A - Inspecting method for can seam part - Google Patents

Abstract

PURPOSE:To speedily inspect and measure respective points of the seam part of a can to be inspected in safety by using X-ray perspective information on the seam part. CONSTITUTION:An X-ray source 10 arranged nearby one radial end 4a of the seam part 4 of the can 1 to be measured projects an X ray 10b on front surface of the double seam part 4, i.e. the surface of a chuck wall 4C. Therefore, an X-ray transmission intensity distribution corresponding to how a body hook and a cover hook overlap each other at the lower end 4b of the double clamp part 4 is inputted as the X-ray perspective information to an X-ray camera 11 arranged nearby behind the seam part 4. An image processor 12 processes this information and displays the front perspective image of the seam part 4 on a display 13 and then the seam part 4 is inspected and measured speedily in safety.

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 food container.

[Prior Art] Metal cans used as containers for canned foods, etc. are made up of a can body, a can lid, and a can bottom. In the case of a so-called three-piece can, 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 body is constructed by wrapping the can 4 around the can body to seal the can. The seaming part of this can body and can lid (hereinafter referred to as "can A" including the bottom of the can) is a pode hook (
B H) and the 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. That is, 1 Podevutsk (B
Cans with defects in the seaming part, such as because the overlapping part (OL) between H) and the cover hook (CH) does not have a certain length, cause problems such as spoilage of the contents due to poor sealing. For this reason, it is necessary to periodically inspect the seam portion of a can that has completed the first seam process and to control the process to prevent the occurrence of poorly seamed cans.

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, since cutting with a scroll saw requires time and effort at the locations where such inspections and determinations are made, normally only three locations are inspected around the entire circumference of the seaming part.
, X.

[Problems to be solved] As mentioned above, the conventional method for inspecting the seaming part of a can uses a scroll saw to cut the seaming part, thereby inspecting three places,
This was done by setting measurement points.

However, this cutting operation is troublesome and involves the risk of cutting fingers.

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 has been made to solve these problems, and by using X-ray fluoroscopic information of the seamed portion, in particular, fluoroscopic information from broad focus X-rays, it is possible to obtain reliable inspection results. To provide a method for inspecting a seaming part of a can, which allows each point of a seaming part to be inspected and measured safely, quickly and easily.

[Means for Solving the Problems] In order to achieve the above object, the method for inspecting a can seam portion of the present invention includes an X-ray source placed close to one radial end of a can seam portion to be inspected. By projecting X-rays toward the X-ray information input means disposed near the other end of the can seaming part, X-ray fluoroscopic information of the front side of the can seaming part is input to the X-ray input information means, and this This method uses line perspective information to measure the seamed portion of a can.

Here, the front surface of the can seaming part refers to the zipper wall surface of the can seaming part or the seaming φ wall surface.

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

First, an example of an apparatus 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 part.

In FIG. 1, reference numeral 1 denotes a can to be inspected, and a seaming portion 4 is formed at the end in the axial direction to connect the can body 2 and the can M3. As shown in FIG. 2, this seaming part 4 is formed by crimping a podium 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 M3. They are formed by firmly interlocking with each other. In order to judge the quality of this seaming part 4, it is necessary to check the podium hook (BH), cover hook (CH), and their overlapping part (
OL), etc., are required.

10 is an X-ray source whose focal point is 31φ or more (usually 5II1
A so-called broad focus X-ray tube with a diameter of approximately 1φ is used. The X-ray energy emitted by the X-ray [10] 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.

[The following margin 1 ll is X as a means of inputting X-ray information! ! It is a camera,
X-ray fluoroscopy information regarding the seaming portion 4 is input. That is, the seaming part 4 of the can l is placed between the X-ray [tlO and the X-ray camera 11, and the X-rays that have passed through the seaming part 4 are used as X-ray fluoroscopic information regarding the seaming part 4. input. Here, the can 1 is arranged with its central axis substantially perpendicular to the X-ray line. Also, an X-ray source 10 and an X-ray camera 1
1 are arranged close to the lower ends 4a and 4b of the seaming portion 4, respectively.

When arranged in this way, the X-rays from X-rays@10 will pass through two locations, the upper end 4a and the lower end 4b of the seaming portion 4. However, since the X-ray source 10 used in this embodiment is a broad focus xi tube with a large focus, and this is arranged close to the upper end 4a of the seaming part, X-rays passing through the upper end 4a of the seaming part 10a is diffused as shown in the figure, making it impossible to input it to the X-ray camera 11, or even if it can be inputted, it becomes blurry and cannot be imaged. On the other hand, the X-rays 10b passing through the lower end 4b of the seaming are transmitted through the lower end 4b and then input into the X-ray camera 11 at a nearby position, resulting in clear image information.

Based on the above principle, the X-ray fluoroscopic information regarding the upper end 4a of the seaming portion can be ignored, and the X-ray camera 11
In this case, only the X-ray fluoroscopic information regarding the lower seaming end 4b is clearly input.

Reference numeral 12 denotes an image processing device, which processes the X-ray fluoroscopic information of the seaming part 4 inputted to the X-ray camera 11, such as emphasizing the brightness and darkness contrast, and displays a front perspective image of the seaming part 4 on the display 13. do.

As shown in Fig. 2, the front perspective image is a two-dimensional image A that shows the degree of overlap of the podium hook (BH) and cover hook (CH) using the contrast of black, white, and gray.
, and a one-dimensional image B in which the strength of contrast in this two-dimensional image is displayed graphically. 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 dimension 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.

X-rays are projected from the X-ray source IO onto the front of the seaming portion 4 (the surface of the chuck wall 4c). Then, the X-ray camera 11, which is placed near the back of the seaming part 4, detects The intensity distribution is input as X-ray fluoroscopy information. This X-ray fluoroscopic information is image-processed by the image processing device 12 and displayed on the display 1.
3, front perspective images A and B of the seaming portion 4 are displayed.

Here, the seaming part 4 is as shown by ■ to ■ in FIG.
Divided into six parts. The arrangement of these parts will not change as long as the pod hook (BH) and cover hook (CH) are in a state of engagement. However, if there is a defect such as a short pod hook (BH) or cover hook (CH), the width of each portion changes depending on the content of the defect.

That is, the normal seaming part 4 is as shown in FIG.
The overlapping part (OL) between the podium hook (BH) and the cover hook (CH) has sufficient length. This overlapping part (OL) is the darkest part in the center of the two-dimensional image A. It is expressed in the part ■. Therefore, if the winding condition is not normal because the length of the pod hook (B) I) or the cover hook (CH) is short, etc., the width of the portion (2) in the two-dimensional image A becomes narrow.

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.

In other words, podium hook (BH) = Φ) 1000 cover hook (CH) = 100+■ ton joint part (OL) = 2.

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.

Note that the same parts as those in the apparatus shown in FIG. 1 shown above are given the same reference numerals, and detailed explanations of those parts will be omitted.

The apparatus shown in FIG. 2A uses an X-ray line sensor 21 as an X-ray information input means. That is, X-ray source 1
X-ray 10b transmitted through the seamed lower end 4b after being projected
x! is placed close to the seaming part 4! ! The signal is input to each element of the line sensor 21, converted into an electric signal, and output to the signal processing device 22. The signal processing device 22 processes the electrical signals sent from each sensor element, and
One-dimensional information corresponding to the X-ray transmission intensity distribution (information similar to one-dimensional image B in FIG. 2) is 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 footer (CH), and overlapping part (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, the X-rays projected from the X-ray source 10 and transmitted through the lower end 4b of the first seam are input to the X-ray sensor 31 disposed close to the first seam seam 4. Here, a pinhole (0, 5
A shielding plate 34 is provided with a hole (less than or equal to mφ) 34a, so that only the X-rays passing through the pinhole 34a are exposed to the X-rays.
The ray sensor 31 is manually operated to prevent a decrease in accuracy due to the diffusion of X-rays.

Moreover, in the case of this apparatus, in order to scan the entire seaming part 4, the can l is moved in the axial direction (in the direction of the arrow shown in the figure). Note that the X-ray source 10 and the x1jI sensor 31
Of course, the can 1 may be moved in the direction of the arrow shown in the figure.

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 input signals in one time series to obtain one-dimensional information corresponding to the X-ray transmitted intensity distribution (the one-dimensional image in FIG. 2 and the one-dimensional image 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 which is carried out using the apparatus shown in FIGS. 1, 3(a) and 3(b),
can be inspected and measured extremely quickly based on X-ray fluoroscopic information.

Therefore, the entire circumference of the seamed portion 4 can be inspected and measured many times at short intervals, and 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 a can-sealed portion using an X-ray camera, an X-ray line sensor, or a means other than an X-ray sensor capable of detecting the xa-transmitted intensity distribution as an X-ray information input means.

(2) A method for inspecting a can-sealed portion in which a means for preventing halation occurring at the periphery of an X-ray fluoroscopic image of the seam-sealed portion is provided on the path of X-rays projected from an X-ray source.

The above halation prevention means is unnecessary when the X-ray information input means is other than an X-ray camera.

■An inspection method for can seaming parts that uses X-ray fluoroscopic information to automatically determine whether the can seaming parts are good or bad.

[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 drawings]

FIG. 1 is a configuration diagram showing an example of an apparatus for carrying out the method of the present invention, FIG. 2 is a diagram showing a cross section and an X-ray front perspective image of a can seaming part, and FIGS. 3(a) and (b) ) are configuration diagrams showing other device examples.

Claims (6)

[Claims] (1) Projecting X-rays from an X-ray source placed close to one radial end of the seam portion of the can to be inspected toward an X-ray information input means placed near the other end of the seam portion of the can to be inspected. By this, X-ray fluoroscopic information of the front side of the can crimping part is input into the X-ray input information means, and the can crimping part is measured using this X-ray fluoroscopic information. Inspection method. (2) The method for inspecting a can seam portion according to claim 1, wherein the X-ray source is a broad focus X-ray tube. (3) The method for inspecting a can seam portion according to claim 1 or 2, wherein the X-ray information input means is an X-ray camera. (4) The method for inspecting a can seam portion according to claim 1 or 2, wherein the X-ray information input means is an X-ray sensor. (5) The method for inspecting a can cinching portion according to claim 1 or 2, wherein the X-ray information input means is an X-ray line sensor. (6) The method according to any one of claims 1 to 5, characterized in that the central axis of the can to be measured is perpendicular to the line of X-rays projected from the X-ray source. Inspection method for can seaming section.