JPS6310362B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an inspection device for inspecting whether or not the opening side seam flange of an empty can is abnormal.

One of the defects that occur during the manufacturing process of canned goods is poor seaming. This is caused by an external impact being applied to the empty cans before filling and seaming, or by collisions between empty cans, which deforms the opening seam flange that is expanding outward. It is something that occurs. When the flange is seamed in a deformed state as described above, a protruding portion A occurs as shown in Figs. 1 and 2b, causing false seaming.
Compared to the normal seaming shown in FIG. 2a, even if the can can be temporarily sealed, it will eventually become a defective can. In order to prevent such false seaming, it is necessary to check for abnormalities in the flange immediately before filling and seaming, but conventionally, inspection is done visually, which can easily lead to oversights or removal errors. be. Therefore, it has been considered to perform inspection using an optical inspection device, but this has the disadvantage that it is difficult to distinguish between light incident on the light receiver during normal times and light incident on the light receiver during abnormal times, making it easy to make inspection mistakes.

In view of this fact, the present invention provides an empty can inspection device that prevents inspection errors from occurring.The present invention is characterized in that an inspection head is disposed above the inspection position on the empty can transport path. A hood is fixed to the lower surface of the head, and an annular slit is formed along the vertical direction directly above the seam flange on the opening side of the empty can brought to the inspection position of the hood, and a flange is attached to the hood. An annular groove is formed along the direction of the inscribed line, a light source is provided in the inspection head that emits an annular beam of light to the flange through the annular slit, and a number of light receiving sensors are arranged at appropriate intervals within the annular groove. According to this configuration, an annular beam of light is emitted from directly above the empty can toward the flange, so when the flange is normal, the beam of light that hits the flange is directed toward the inside of the empty can 8. The light will not be received by the light receiving sensor. Furthermore, even if the reflected light beam is further reflected on the inner surface of the empty can and attempts to enter the light receiving sensor, the light receiving sensor is located within the annular groove, so the light is blocked and the reflected light will not enter the light receiving sensor. Therefore, a malfunction will not occur if something is abnormal even though it is normal. Furthermore, when the flange is abnormal, the above-mentioned luminous flux hits the abnormal part of the flange, is reflected to the outside of the empty can, and enters the light receiving sensor. Therefore, abnormalities in the flange can be reliably detected.

An embodiment of the present invention will be described below with reference to FIG. 3 and subsequent figures. 1 is an inspection head, and a circular hole 2 is formed in the bottom plate. Reference numeral 3 denotes a hood fixed to the lower surface of the bottom plate of the head 1, which has a through hole in the center, and a circular plate 10 concentric with the through hole is disposed in the through hole. An annular slit 4 is formed along the vertical direction between the outer circumferential surface and the inner circumferential surface of the through hole, and this slit 4 is positioned directly above the opening side seam flange 8A of the empty can 8 brought to the inspection position. be. 5 is flange 8A on hood 3
an annular groove formed substantially along the inscribed line direction of 6;
is a light source placed in the center of the head 1,
An annular light beam is emitted to the flange 8A through the slit 4. 9 is a light receiving sensor arranged at appropriate intervals in the annular groove 5; 7 is a conveyor for transporting empty cans 8 moving in the direction of arrow A; this conveyor 7 brings the empty cans 8 to an inspection position directly below the head 1; The opening side seam flange 8A of the empty can 8 is positioned directly below the slit 4 and on the extension line of the annular groove 5. 20 is a connecting plate that connects the hood 3 and the circular plate 10 to each other. Note that as the light source 6, for example, a fluorescent lamp, an incandescent lamp, or a light emitting diode is used. In the case of fluorescent lights, direct current lighting or high frequency power supply shall be used to prevent flickering. In FIG. 5, reference numeral 11 is an amplifier that amplifies the input signal from each light receiving sensor 9, and has a sensitivity adjustment function to keep the sensor sensitivity level constant. 12
is a detection level setting device according to the can type and the brightness of the light source, and its inspection level light receiving sensor 13 is:
Each light receiving sensor 9 may be placed opposite to a reference empty can.
It is arranged between 14 is each amplifier 1
A comparator that outputs when the input signal value from 1 becomes larger than the input signal value from the detection level setter 12, 15 an OR circuit that receives the input signal of each comparator 14, and 16 an empty can 8 connected to the tapered portion 4A. 17 is an amplifier for amplifying the input signal of the photo switch 16; 18 is a pulse generator for generating pulses based on the input signal from the amplifier 17; The AND circuit 19 is an AND circuit that receives and outputs an input signal from the pulse generator 18 and an input signal from the OR circuit 15.
The output signal is input to a predetermined abnormal can discharge circuit.

The operation of the above configuration will be explained. First, when the empty can 8 is brought to the inspection position directly below the head 1 by the conveyor 7, the light emitted from the light source 6 passes through the slit 4 and becomes an annular beam of light, as shown in FIG.
It is projected onto the flange 8A. Here flange 8A
If the shape is normal as shown by the solid line in Figure 6, then
The light beam hits the flange 8A and is reflected to the inside of the empty can 8, and is not received by the light receiving sensor 9. Furthermore, even if the reflected light beam is further reflected on the inner surface of the empty can 8 and tries to enter the light receiving sensor 9, since the light receiving sensor 9 is located within the annular groove 5, the light is blocked and the reflected light enters the light receiving sensor 9. Never. Therefore, no signal is output from the light receiving sensor 9, and the empty can 8 passes under the head 1 as it is. Next, as shown by the imaginary line in Fig. 6, the flange 8A
If the shape is abnormal, the light beam hitting the abnormal part of the flange 8A is reflected to the outside of the empty can 8 and enters the light receiving sensor 9. Then, a signal is output from the light receiving sensor 9, amplified by the amplifier 11, and compared with the input signal from the detection level setter 12 by the comparator 14. If the input signal value from the light receiving sensor 9 is larger, the signal is output from the comparator 14. A signal is input to the OR circuit 15. At the same time, the photo switch 16 detects the empty can 8, and the signal thereof is inputted to the pulse generator 18 via the amplifier 17, and the pulse generator 18 emits a pulse. The AND circuit receives the signal from the pulse generator 18 and the signal from the OR circuit 15, and inputs the signal to the abnormal can ejection circuit. An empty can 8 having an abnormally located flange 8A is discharged from the conveyor 7.

As described above, according to the empty can inspection device of the present invention, since the annular light beam is emitted from directly above the empty can toward the flange, when the flange is normal, the light beam hitting the flange is empty. The light is reflected to the inside of the can 8 and is not received by the light receiving sensor. Furthermore, even if the reflected light beam is further reflected on the inner surface of the empty can and attempts to enter the light receiving sensor, the light receiving sensor is located within the annular groove, so the light is blocked and the reflected light will not enter the light receiving sensor. Therefore, a malfunction will not occur if something is abnormal even though it is normal. Furthermore, when the flange is abnormal, the above-mentioned luminous flux hits the abnormal part of the flange, is reflected to the outside of the empty can, and enters the light receiving sensor. Therefore, abnormalities in the flange can be reliably detected.

[Brief explanation of the drawing]

FIG. 1 is a front view of the abnormal can, FIG. 2a is a vertical cross-sectional view of the main part of the normal can, and FIG. 2b is a vertical cross-sectional view of the main part of the abnormal can. Figure 3 and the following figures show one embodiment of the present invention. Figure 3 is a partially cutaway front view, Figure 4 is a view taken along the - arrow in Figure 3, and Figure 5 is an abnormal can detection circuit diagram. 6
The figure is an enlarged longitudinal sectional view of the main part. 1... Inspection head, 3... Hood, 4... Slit,
5... Annular groove, 6... Light source, 8... Empty can, 8A... Opening side seam flange, 9... Light receiving sensor.

Claims (1)

[Claims] 1. An inspection head is arranged above the inspection position on the conveyance path of empty cans, a hood is fixed to the underside of the head, and a place directly above the opening-side seam flange of the empty can brought to the inspection position of the hood. an annular slit extending vertically in the hood, and an annular groove extending substantially in the inscribed line direction of the flange, and a light source for emitting an annular beam of light to the flange through the annular slit is provided in the inspection head; An empty can inspection device characterized in that a large number of light receiving sensors are arranged at appropriate intervals in an annular groove.