JPH02126142A - Can coating inspecting device - Google Patents

Abstract

PURPOSE:To accurately discriminate whether coating is good or not by reporting a defect of coating based on results of comparison between a peak value of operation results of detection signals obtained from a standard can and a can to be inspected and respective set values of upper and lower limits. CONSTITUTION:When a standard can 5 and a can 6 to be inspected are photographed by a camera 9, light reception signals outputted from sensors 12a and 12b are amplified by amplifiers 13a and 13b, and the error signal from sensors 12a and 12a is given to a peak holding circuit 15 by an operating circuit 14. Meanwhile, a signal proportional to the distance between cans 5 and 6 is outputted from a transmission/reception part 10a of a position sensor 10 and is given to the circuit 15. The peak value for cans 5 and 6 from the circuit 15 is given to a window comparator 20 and is compared with upper and lower limit set values. When the peak value is larger than the upper limit set value or is smaller than the lower limit set value as the result of comparison, a signal in the high level is outputted from the comparator 20 to open a gate 22, and a signal in the high level is outputted from a latch circuit 23 to report a defect of coating of the can 6.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a can coating inspection device [ζ] for inspecting the quality of the inner coating of cans used for canned foods.

[Conventional technology]

Generally, when producing canned foods, the inner surface of aluminum cans is coated with a special paint to prevent changes in the quality of the food.

Since the condition of the coating on the inner surface of a can greatly affects the quality of the food, the quality of the coating on cans is usually inspected. Conventionally, this was carried out as a manual sampling inspection on the can production line. Inspectors are judging the quality of the coating on the inner surfaces of the 15 cans being removed.

At this time, normally coated cans have a duller gloss and poor reflection than uncoated cans, so the inspector's experience and intuition determines whether the coating is good or not based on the gloss level 1 reflection of the 15 cans to be sampled. is determined.

[Problem to be solved by the invention]

Conventional inspections rely on the experience and intuition of inspectors to judge the quality of the coating on the can, which requires skill, lacks accuracy in the judgment results, and has poor work efficiency.

The present invention has been made with the above-mentioned points in mind, and allows accurate determination of the quality of coating on cans, and also improves work efficiency.
- The purpose is to make it possible to achieve the following.

[Top means to solve problems]

In order to achieve the above object, the can coating inspection apparatus of the present invention includes a standard can whose top surface is open and whose inner surface is coated, and a standard can whose top surface is open and whose inner surface is coated and which is placed adjacent to the standard can by a conveyor f. the test food can being transported to the measurement position f; one illumination means for simultaneously illuminating the standard can and the test food can at the measurement position from above; one camera that simultaneously photographs the cans to be sampled; a sensor comprising a photoelectric conversion element that is provided at each imaging position p of the cans of the camera and outputs a received light signal proportional to the amount of received light f; a position sensor that detects movement of the food can to be tested to the measurement position and outputs a detection signal; an arithmetic circuit that calculates an error between the two received light signals and outputs a calculation signal; A peak hold circuit holds the peak value of the memorizable calculation signal, and compares the peak value with an upper limit setting value and a lower limit setting value,
a comparator that outputs a Cζ detection signal when the peak value is larger than the upper limit setting value and when the upper and lower limit setting values are also smaller; and a notification means that uses the detection signal f to notify that the inner surface coating of the food can to be inspected is defective. It is characterized by the following.

[Effect]

[Second] Ii: Since the bottom of the groove is formed, the error in the received light signals from both sensors is calculated by the calculation circuit in proportion to the reception of reflected light from the standard can and the test food can at the measurement position. The peak value of the calculation signal from the circuit is held,
This peak value is compared with the upper limit setting value and the lower limit setting value by a comparator, and as a result, if the peak value is greater than the upper limit setting value or smaller than the lower limit setting value,
The reflected light from the test food can is strong, and it is determined that the coating of the test food can is defective, a detection signal is output from the comparator to the notification means, and the notification means reports that the coating of the test food can is defective. .

On the other hand, if the peak value is between the upper limit setting value and the lower limit setting value, it is determined that the coating of the food can to be tested is good, the comparator does not output a detection signal, and the notification means does not operate.

〔Example〕

Embodiment f will now be explained with reference to the drawings.

Figures 3 to 5 showing the groove bottom (in ζ, (1) is a vertically elongated frame, (2) is a frame provided slightly below the center of the frame (1), The direction conveyor (3) is arranged on both sides Cζ on the left and right sides of the frame (1), and the top surface is the conveyor (2).
), the mounting table (4) is located at the same height as the frame (1)
(5) is a standard can that is placed behind the conveyor (2) inside the frame (1) and has an open top and a coated inner surface. The test food can has an open top and a coating on the inside, and is placed on a conveyor (
2) and provided on both sides of the conveyor (2) r: 'a
The feeding guide (7) transports the standard can (5) to the measurement position adjacent to the standard can (5). Illumination means consisting of one ring light that simultaneously illuminates 6) from above. ・(9) is installed above the outside of the frame (1) and simultaneously photographs the standard can (5) and the part to be inspected (6) at the measurement position. One camera, 00, is an ultrasonic position sensor, consisting of an ultrasonic wave transmitting/receiving unit and a waveform rod shape for shaping the output signal of the wave transmitting/receiving unit, and is installed in front of the measurement position m1. Conveyor (2
) detects the distance to the part to be inspected (6) from the diagonal ultrasonic wave emitted from the part to be inspected (6), and when this detected distance falls within a predetermined range, the Detects the measurement position/movement of part (6) and outputs a detection signal.

Note that (1) is a restraining device that controls the conveyance speed of the conveyor (2), etc.

Next, Cζ and FIG. 1 showing the bottom of the circuit groove will be explained.

In the same figure, (10a) and (job) are position sensors (ultrasonic wave transmitting/receiving unit and waveform shaping unit that groove bottom the IQ) as shown in ■, and (12a) and (12b) are f-co cameras as shown in Figure 2 EC. First and second sensors (1 and 2) each consisting of a photoelectric conversion element that outputs a light reception signal proportional to the amount of light received, which are provided at the junction positions of both cans (5) and (6) of (9), respectively;
3a), c 131)) both sensors (12a),
(12b) is an inverting amplifier and a non-inverting amplifier that amplify the received light signals from the amplifier (13a),
(13b) is input to both sensors (12a).

(12I))) is a calculation circuit that calculates the error in the light reception signal and outputs a calculation signal, α9 is a peak hold circuit, and holds the peak value of the calculation signal based on the detection signal from the position IS sensor (10).

aQ is both augmentation) ffi (13a) I (13b) and U L”y Ho Jl/ The output signals of F circuit α9 are input, and these signals are selectively switched to meter αη.
The switch that outputs this, (marked 1, (II is the upper limit setting value La and lower limit setting value 1.l, respectively), the upper limit setter and lower limit setter for setting, (to) is the window comparator, and the peak hold The peak value of the circuit 0j is compared with the upper limit setting value La and the lower limit setting value Lb, and a detection signal is output when the peak value is larger than the upper limit setting value La and smaller than the lower limit setting value Lb.

&l) is a monomulti operated by the input of the detection signal from the position sensor (lfl), 15 is a gate that opens by inputting the pulse of the monomulti Cυ color, and (to) is the production signal from the comparator ClO which is latched. It is latched and output to the alarm, and the alarm is driven to notify the defective inner coating of the inspected part (6).

@ is a latch circuit (c) glue 1. It is Chi.

By the way, both sensors (12a) for the coated cans (I) and (t).

(12b) At the end of the test to check the output characteristics of the conveyor (2
) is photographed by the camera (9) while illuminating it with the illumination means (8), and the output voltage waveform of the second sensor (12t) at that time is measured. Comparing the waveform j for the coated can tζ shown by the solid line in the same figure, the peak value of the waveform for the uncoated can shown by the dashed line in the same figure is very high. By checking whether the peak value of the output signal of :/+jo2b) is within a predetermined range, it is possible to determine the quality of the coating on the inner surface of the can. Note that the output characteristics of the first sensor (12a) are also the same as those of the second sensor (12+).

At this time, '4' in FIG. The axis shows the output voltage of the sensor, the horizontal sleeve shows the distance traveled by the conveyor (2) 1ζ, D corresponds to the diameter of the can to be measured, and the can is placed at the measurement position where the distance between the can and the position sensor αa is the shortest. The distance traveled is expressed with the time at which the can is reached as zero, and when the can reaches the measurement position fζ, the output signal of the sensor reaches its peak.

Next, the operation ζ during actual inspection will be explained using FIG. 7.

Now, when the standard can (5) and the inspected part (6) conveyed by the conveyor (2) are photographed by the camera (9),
The light reception signals output from the first and second sensors (L2a) and (12b) are amplified by the amplifiers (18a) and (13b), respectively, and the amplification>m (18a), (13b)
), signals as shown in FIG. The error is calculated and an arithmetic signal as shown in FIG. 3(C) is output.

-G, position sensor (l (from the wave transmitting/receiving unit (LOA) of 1,
As shown in Fig. 7 01), the distance St to the inspected part (6)
A signal proportional to tζ is output, and the waveform shaping section (job) of the position sensor (1G) shapes the output signal of the wave transmitting/receiving section (LOA). A wavy signal is output from the waveform shaping section (10b') to the peak hold circuit 051.

Then, the peak hold circuit Go detects as shown in Figure (1) ('7X month's γ-1- is set to 9 and is reset to 7, and at the same time it is set to 1 by the fall,
The IT/domain circuit 09 operates at the high level of the detection signal, and the peak of the calculation signal between the high level and the high level of the detection signal peaks at the falling timing of the detection signal. The hold circuit (19 holds tl, Fig. 7 (cl)) The signal that hangs is peak held IjJ '18 On Color comparator (
1, and the output signal of the peak hold circuit 09 is outputted to the output signal of the peak hold circuit 09 by the comparator 1 notor C1.
The upper limit setting values I and a and the lower limit setting value 1. ,
l) is compared.

N i = s, m7ffi (d) + The output signal of the peak hold circuit Q9 shown here exemplifies the signal 5J for the first test target [i (6), and the output signal of the second and subsequent peak hold circuits 09 The signal has a waveform that continues to have the peak value for the previous inspected part (6) until the detection signal rises as shown in FIG. 7(j).

At this time, if the peak value held by the peak hold circuit (191) is larger than the upper limit setting value La, the camera (9) takes a picture of the can (6) to be inspected. , or when it can be determined that the coating is defective, a high-level detection signal as shown in FIG. 7(e) is output from the comparator (1) to the gate (a).

Also, when the peak value held by the peak hold circuit (19) is smaller than the lower limit setting value Lb, a detection signal of high 1 novel is output from the comparator (a) in the same way, and the peak value is ” If the value is between the 1st limit setting value La and the lower limit setting value Lb, the comparator (1
) output remains as a row 1 novel.

By the way, the detection signal of the position sensor scream is Monomulti e21
) is also inputted to the pulse width Q, which rises in synchronization with the fall of the detection signal 1, as shown in Fig. 7(j) (ζ)
I\I1 Novel Perse is monomulti Cυ Karakate @)
While the gate (a) is open, the high level detection signal from the comparator 31 is output to the latch circuit via the gate (a) as shown in (f) of the same figure. c! 3i is input and latched, and the latch circuit outputs a high-level signal as shown in the figure (get) to the alarm. ” will be done.

In addition, if you are stuck with the operation of Reuse no hsui, C) A, please refer to Fig. 7 (
k) There is a C/F level cent signal as shown in the figure below.
When tl is input into the latch circuit, the latch circuit is reset.

On the other hand, if the peak value is between the -L limit setting value and the lower limit setting value as a result of the comparison using Konipashi-ta c1, then:
The output of the latch circuit remains at low level, and the signal input to the latch circuit through the open gate is at low level, and the output of the launch circuit also remains at low level. , the alarm is never on duty.

Therefore, the workbench only needs to check whether there is an alarm or not, and it is possible to judge the quality of the coating on the can more accurately than in the past, and it is possible to improve work efficiency by automating the inspection. Can be done.

The above-mentioned inspection may be carried out on all inspected parts (6), but it may also be carried out as a sampling inspection as in the past. Perform signal processing on the part to be inspected (6) for a predetermined number of parts Cζ
It is sufficient to shift fζ so that it is divided by one.

In the above embodiment, as shown in FIG. of…
■Install it tilted in the direction, and standardize it in this way (
5) and the part to be inspected (6) at the measurement position are uniformly illuminated at the same time, and the illumination means (8)
The camera (9) may be disposed closer to the front of the second part of the frame (1), and the central axes of the illumination means (8) and camera (9) may be tilted slightly rearward.

〔Effect of the invention〕

The present invention, which will be explained below, has the following grooves, so it produces the effects described below.

The amount of reflected light received from the can and the inspection target A at the measurement position is proportional to 1, and the error in the received light signals from both sensors is calculated by the arithmetic circuit f, and the peak value of the arithmetic signal from the arithmetic circuit is calculated. is held by a peak hold circuit, and a comparator compares the peak value with the upper and lower limit setting values,
When the peak value is larger than the upper limit setting value or smaller than the lower limit setting value, the detection signal output from the comparator activates the notification means to notify the coating defect. It is possible to automatically determine the quality of the can coating, and compared to conventional methods,
It is possible to accurately judge whether the coating is good or not, and work efficiency can be greatly improved.

[Brief explanation of drawings]

The drawings show one embodiment of the can coating inspection device of the present invention, and FIG. 1 is a bottom view of a bronc groove, and FIG.
Schematic diagrams, Figures 3 to 5 are the front N, top view, and right side view, respectively, Figure @6 is the output characteristic diagram of the sensor, and Figure 7 (a
) to -, respectively, are signal waveform diagrams for explaining the operation. (2)...Conveyor, (5)...Standard 1 hill, (6)
...Test food can, (8)...Lighting means, (9)...
Camera, al...position sensor, (12a), (12b
)... 1st. 2nd sensor, Q(4)/arithmetic circuit, 09
... Peak hold circuit, 0 mark ... Upper limit setter, 0
! J...lower limit setter, (4)...computer 1/-ta, @
...Latch circuit.

Claims (1)

[Claims] (1) A standard can whose top surface is open and whose inner surface is coated; a can whose top surface is open and whose inner surface is coated and which is transported by a conveyor to a measurement position adjacent to the standard can; the standard can and the measurement can; one illumination means that simultaneously illuminates the can to be inspected at the position from above; one camera for simultaneously photographing the standard can and the can to be inspected at the measurement position; and imaging of both the cans by the camera. a sensor consisting of a photoelectric conversion element that is provided at each position and outputs a light reception signal proportional to the amount of light received; a position sensor that detects movement of the can to be inspected to the measurement position by the conveyor and outputs a detection signal; an arithmetic circuit that calculates an error between the two received light signals and outputs a calculated signal; a peak hold circuit that holds the peak value of the calculated signal based on the detection signal; Compare,
A comparator that outputs a detection signal when the peak value is larger than the upper limit setting value and smaller than the lower limit setting value, and a notification means that uses the detection signal to notify a defect in the inner surface coating of the can to be inspected. A can coating inspection device characterized by: