JPH02309208A - Inspection of weld lap quantity for welded can - Google Patents

Abstract

PURPOSE:To achieve a higher measuring efficiency by a method wherein a welded can is arranged between a radiation source and a camera device to take a radiation with the camera device as passing through a weld part of the can and a signal from the camera device is processed to read condition of the weld part. CONSTITUTION:A welded can 10 for inspection is arranged between a radiation device 12 and a camera device 14 and held so that a radiation 13 from the radiation device 12 becomes perpendicular to a weld part 11. At this position, the weld part 11 is exposed to the radiation 13, a view through image of the radiation of the weld part 11 is taken with the camera device 14 and an integration of an image data and a required image emphasizing are performed with an image processor 16. The image thus processed is binary coded with a computer 20. The number of pixels is counted across the width of the weld part 11 from a binary coded image data thus extracted and processed to determine a lap quantity (u) of welding. This facilitates the recording, reproduction and printing out of data and other operations thereby achieving a higher measuring efficiency.

Description

[Detailed description of the invention] 111 Chizuri±! The present invention relates to the field of welded cans, and more specifically, underweld, overweld,
The present invention relates to a method for non-destructively inspecting the thickness and width of a welded lap portion such as a wrap, that is, the amount of welded lap.

Yueren! Conventionally, the weld lap amount of welded cans has been inspected by using a welding machine to specially inspect the can C, which is a can with both ends of the side seam S shown in Fig. 5 not welded over a length g. Then, the cross-section of the can was cut at points A and B, and an inspector examined the cross-section of the lap part using a microscope.

The above-mentioned method of inspecting the weld lap amount of conventional welded cans has the following drawbacks.

(1) Since we had to intentionally use sample cans for inspection that did not have both ends welded, the machine had to be temporarily stopped.

(2) When making sample cans, the welding current conditions are different from those used when welding regular cans, so the test values lack reliability.

(3) The used sample cans are destroyed and visually inspected using a microscope, which is time-consuming.

In order to solve the above problems, the present invention uses cans formed under the welding current conditions during normal can manufacturing, without producing sample cans for inspection, and by welding the welded wrap of the welded cans. The amount of radiation is non-destructively inspected using fluoroscopic imaging, transmitted dose method, and dose absorption coefficient method.

1-month A welding can is placed between the radiation source and the imaging device.

At this time, the welded part of the disclaimer is located on the surface of the imaging device, and the disclaimer is held so that the radiation is orthogonal to the welded part.

A computer calculates information such as the transmission state when radiation is applied to the welded part, the density level of the fluoroscopic image, the voltage level of the transmission amount, and the pulse number conversion of the transmission amount. After the process is completed, the can is moved in the welding direction to the next welding position and the same inspection is performed.

First, the weld lap amount of the same welded can (sample can) is inspected (measured) using both the method of the present invention and the conventional method, and the results are compared. By determining the range (standard range of weld lap amount), it is possible to automatically determine whether the inspection value of the weld lap amount of cans manufactured under normal can manufacturing conditions tested by the method of the present invention is good or bad. .

The same welded can (sample can) can be inspected using both methods only when conditions such as the material to be welded or the welding speed are changed.

Figure 1 is a schematic diagram of a device for inspecting the amount of welded lap on welded cans, and number 10 is a welded can for inspection extracted from a row of cans formed on a normal production line (not shown). . Further, numerals 12 and 14 are a radiation device and an imaging device, respectively, which are known per se, and 16, 18, 20 and 22 are an image processing device, an impose board, a computer, and a monitor, respectively. All are publicly known.

In the present invention, when detecting the weld lap amount of the welded can 10, the inspection welded can 10 is placed between the radiation device 12 and the imaging device 14. At this time, the canister 10 is held so that the welded part 11 of the welded can 10 is located on the upper surface of the imaging device 14 and the radiation 13 from the radiation device W 12 is perpendicular to the welded part 11 as shown in FIG. 1a. do. Radiate to welding part 11 at this position! 113, a radioscopic image of the welded part 11 is taken in by the imaging device W 14, and the image data is integrated and the necessary image enhancement is performed by the image processing device 16, and the resulting image is binarized by the computer 20. The number of pixels is counted in the middle direction of the welding part 11 from the binary image data extracted and processed in this way, and the welding overlap amount U (see FIG. 1b) is determined. Here, FIG. 2 is a diagram showing an example of image data showing the amount of wrap obtained by the applicant using the above method.

FIG. 3 is another welding lap amount inspection device, more specifically, an overall schematic diagram of a device for extracting the welding lap amount based on a change in the permeation amount level. Numbers 30 and 3 in this diagram
2 is a radiation device and an imaging device similar to those shown in FIG. In this inspection device, a welding can 34 disposed between a radiation device 30 and an imaging device 32 is held in the same manner as in FIG. If the level of the amount of radiation transmitted is replaced with an electrical signal and the electrical signal is amplified by the amplifier processing circuit 36, a predetermined signal waveform 39 is formed on the screen of the oscilloscope 38. The width V of the trough in this signal waveform 39 is calculated by the computer 40 to determine the amount of overlap. Note that FIG. 3a is a view taken along the line a-a in FIG. 3.

FIG. 4 shows yet another weld lap amount inspection device.

In this embodiment, a warning sign 46 is disposed between the radiation device 42 and the imaging device 44 so that the welded portion 47 of the welding can 46 faces the surface of the imaging device 44, as in the above embodiment. Next, another imaging device 45 is placed on the radiation equipment W42 side above the notice 46.

In this state, the radiation device 42 emits radiation &143. A portion of the radiation 43 reaches the imaging device W 44 via the weld 47 of the can 46, and the other portion reaches the imaging device 45 via the bending device 48. Signals from each imaging device W44.45 are processed by a signal processing circuit 50, and the ratio of the radiation dose that has passed through the welded portion 47 and the radiation dose that has not passed through the welded portion 47 is determined, and this is compared and image processed and sent to the oscilloscope 52. When photographed, the signal waveform 53 appears. If the width W of the peak in this signal waveform 53 is calculated by the computer 54, the amount of overlap can be determined. Note that FIG. 4a is a view taken along the line a-a in FIG. 4.

Since the inspection is performed in the same state, the work does not take much time and effort. Furthermore, since the calculation of the amount of wrap is processed by a computer, recording and reproducing data, printing out, etc. are facilitated, and measurement efficiency is improved. Furthermore, since the cans produced under the welding current conditions in the normal production process are inspected, the inspection values are more specific and reliable, and there is no human error caused by visual inspection, so the inspection values are Increases accuracy.

[Brief explanation of the drawing]

Fig. 1 is a schematic diagram of the first weld lap amount inspection device of the present invention, Fig. 1a is a view taken along arrow a-a in Fig. 1, and Fig. 1b is a direct image of the lap part after processing as shown on a monitor. FIG. 2 is an enlarged view of the image showing the amount of lap in FIG. 1, FIG. 3 is a schematic diagram of the second welding lap amount inspection device of the present invention, and FIG. Fig. 4 is a schematic view of the third welding lap amount inspection device of the present invention, Fig. 4a is a view taken from a''-a in Fig. 4, and Fig. 5 is a known welding lap amount inspection. It is a perspective view of a welded can for inspection with the device. Explanation of symbols 10.34.46: Inspected can 11.35.47: Welded part 12.30.42: Radiation device 13.31.43
:Radiation 14.32.44.45:Imaging device 16:Image processing device 18:Impose board 20.40.54:Computer 22:Monitor 3
6: Amplifier processing circuit 38, -52 = Oscilloscope 39. 53: Signal waveform 48: Bending device 50: Signal processing circuit U, ■, W: Detected lap amount

Claims (1)

[Scope of Claims] 1. A method for inspecting the amount of weld lap of a welded can, comprising positioning the welded can between a radiation device and an imaging device so that the welded portion faces the imaging device; Projecting radiation from a radiation device so as to be orthogonal to the can, capturing an image of the radiation that has passed through the welded part of the can with an imaging device, and processing the signal output from the imaging device to decipher the condition of the welded part.
A method for detecting the amount of welding lap in a welded can consisting of: 2. According to claim 1, the step of processing the signal output from the imaging device to interpret the state of the welded portion is an image processing step for clarifying the outline of the welded portion based on a radioscopic image of the welded portion. Method for detecting weld lap amount. 3. A claim characterized in that the step of processing the signal output from the imaging device to interpret the state of the welded portion is a step of inspecting the lap amount of the welded portion based on a change in the level of transmitted radiation due to radiation in the welded portion. 1. The weld lap amount detection method according to 1. 4. The process of processing the signal output from the imaging device to interpret the state of the weld is a process of inspecting the amount of lap of the weld based on a change in the dose absorption ratio due to radiation passing through the weld. The weld lap amount detection method according to claim 1.