JPH0317259Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a glue adhesion condition inspection device for inspecting whether or not adhesive glue is adhered to a carton in a desirable state during a carton manufacturing process.

Conventionally, we have investigated whether or not the glue is attached to the carton in a desirable manner (in other words, whether the glue has broken, the glue has smeared, or
There is no suitable device for inspecting (for excessive adhesion); for example, there are commercially available devices that electro-optically inspect the glue by mixing a coloring agent with it, but it is not practical. Moreover, it was not possible to conduct a sufficiently accurate and reliable test.

The present invention was developed in consideration of these circumstances, and by electrostatically testing the amount of glue,
It is possible to accurately and reliably inspect whether or not the glue is properly attached to the carton.In particular, when the inspection head is equipped with a matching trimmer for adjusting the inspection level and the inspection head detects the capacitance using this, This adhesive adhesion state inspection device is characterized in that the detection level can be corrected.

The present invention will be explained in detail with reference to an example below.
1, 2 and 3 show an inspection head 10 used in the present invention. In the figure, 1 is a carton that is an object to be inspected to see whether or not the glue 3 is properly adhered to it. ing.

The inspection head 10 has two opposing substrates 11 and 1.
1, and the adhesive portion 2 of the carton 1 is transported between the bases 11, 11 in the direction of the arrow 5 by a transport mechanism of a so-called sac pasting machine (not shown),
At this time, the adhesive condition of the carton 1 is inspected.
Pole plates 13, 13, 13, 13 for detecting capacitance are formed in parallel on both sides of each base plate 11, 11, and the plate 13 is used to transport between the bases 11, 11. Detect the capacitance of carton 1. Further, a light emitting device and photo sensors 14, 14 are attached to both sides of the base 11, and a signal from the photo sensor 14 causes the carton 1 to be
A timing signal 72 (see FIGS. 5 and 6 below) indicating that a is present between the substrates 11 and 11 is obtained. A shield plate 1 made of a metal plate is provided on the outside of the base 11.
7, 17, 17, 17 are installed at intervals of 18 and surrounding three sides, and this shield plate 1
7, the capacitance measurement area of the carton 1 is limited to the area between the bases 11 and 11 inside the shield plate, thereby preventing malfunctions due to flapping of the carton 1, static electricity of the transport belt, the carton 1, etc. By changing the distance 18 between the shield plates 17,
This device can be used for cartons 1 of various shapes such as small size.

For ease of understanding, the shield plate 17 is shown in a removed state in FIGS. 1, 2, and 3, and the attached state is shown with a dotted line. Furthermore, although the glue is actually attached to the bottom surface of the carton 1 as shown in FIG.
In the figure, it is depicted as being attached to the top surface.

The upper base 11 is attached via a hinge 19 so as to be openable and closable, so that when paper powder or scattered glue adheres between the bases 11, the base 11 can be opened and cleaned easily.

Next, the test circuit of this device will be explained.

As shown in FIG. 4, signals from the photo sensors 14, 14 provided on the substrates 11, 11 are input to a timing signal generating circuit 50, and this timing signal generating circuit 50 outputs signals from the photo sensors 14, 14 on both sides.
The timing signal 72 becomes high level when both photo sensors 4 and 14 detect carton 1, and becomes low level when at least one photo sensor 14 does not detect carton 1 (see FIG. 5A).
occurs. That is, a series of high level sections 72H corresponds to one carton.

This timing signal 72 is applied to the reference level detection circuit 3.
4. Input to comparison signal generation circuit B44, AND gate circuit 52, counter 54, and shift register 60.

On the other hand, the electrode plates 13, 13, 13 of the inspection head 10,
13 is used to generate a signal for detecting the capacitance within the test head 10 by the capacitive sensor 20. At this time, the matching trimmer 22 is used to correct the capacitance detection level. That is,
In order to be able to inspect a wide variety of cartons 1,
It is necessary to standardize the capacitance detection level, which changes depending on the amount of glue and carton thickness, which differs for each product type, so the capacitance detection level is corrected using the matching trimmer 22 to match each of the conditions. .

Based on the signal from this capacitance sensor 20,
The next capacitance generating circuit 24 outputs an amplitude-modulated capacitance signal. This capacitance generation circuit 24
Since the signal obtained is an amplitude modulated signal, it is amplified by the next stage amplifier circuit 26, then full-wave rectified by the next stage rectifier circuit 28, and then further processed by the next stage sample hold circuit 30. By sampling and holding the peak value, a capacitance signal 74 (see FIG. 5B), which is an analog signal corresponding to the capacitance between the boards 11 and 11, is obtained.

The obtained capacitance signal 74 is input to the comparison circuit A32, the reference level detection circuit 34, and the comparison circuit B42.

Here, the inspection configuration of this inspection device will be explained.

FIG. 6A shows the timing signal 72, and the sixth
Figures B, C, D, and E show the capacitance signals 74 in normal, broken glue, faded glue, and excessive glue, respectively.

As shown in the figure, in order to inspect and judge adhesive breakage, since the part where adhesive breakage occurs appears as a high level part 74H, the reference value V of the glue adhesion surface is obtained and calculations are made based on this value V. The determination can be made by comparing the comparison signal and the capacitance signal 74 and determining whether the capacitance signal 74 is less than or equal to the comparison signal.

In the case of glue stains, the overall level is low as shown in the figure, so the comparison signal B8 at a constant set level is used.
The determination can be made by comparing the capacitance signal 74 with the capacitance signal 74 and determining whether the capacitance signal is greater than or equal to the comparison signal.

If there is too much glue, the level will be high overall, so obtain a comparison signal at a certain set level, compare this comparison signal with the capacitance signal 74, and check whether the capacitance signal is less than the comparison signal. This can be determined by determining whether

In this example, as a comparison signal used for inspecting adhesive breakage and a comparison signal used for inspecting excessive adhesive, the reference value V of the adhesive surface is sequentially measured as described later, and K×V+S (where K is 1 By using the comparison signal A78 (ie, the comparison signal A78 which has a substantially constant value but follows the reference value V of the adhesive surface which changes sequentially at a small rate), the coefficient S is a constant. It is constructed so that two tests can be performed accurately with one circuit, which further reduces the possibility of test errors.

The reference level detection circuit 34 sets a reference level for the portion of the carton 1 to which glue is attached. In setting this reference level value V, even when the same carton is inspected, the amount of glue attached to the carton changes sequentially, so in this embodiment, the reference level is made to follow the changes as described above. This makes the inspection accurate. That is, in this embodiment, the aforementioned timing signal 72
At the rising edge 72T, the value of the capacitance signal 74 is sampled, and this sampled value is held until the next rising edge 72T, thereby obtaining the glue adhesion surface reference signal 76 (see Figure 5C). There is. This glue adhesion surface reference signal 76 corresponds to the value V of the reference level of the glue adhesion portion at that time.

The glue adhesion surface reference signal 76 obtained by this reference level detection circuit 34 is input to the next stage comparison signal generation circuit A36, and the glue adhesion surface reference signal 76 is multiplied by a coefficient K less than 1 in this comparison signal generation circuit A36. After matching, it is shifted to a higher level by a certain level S. This coefficient K and the level S to be shifted can be adjusted by an external setting device A38. This coefficient K
By adjusting the shift level S, the inspection sensitivity is adjusted, thereby preventing inspection errors such as determining good cartons as having poor adhesion, or conversely determining defective cartons as non-defective.

The glue adhesion surface reference signal 76, that is, the comparison signal A78, multiplied by the coefficient obtained by the comparison signal generation circuit A36 and shifted, is input to the comparison circuit A32 and compared with the capacitance signal 74 (fifth
(see Figure E), the capacitance signal 74 is the comparison signal A78
Judgment signal A80 is a pulse signal that is a high level if the level is higher (if the glue is broken or there is too much glue), and is a 0 level pulse signal if it is a low level.
(see FIG. 5F) is configured so that it is output from the comparator circuit A32.

Judgment signal A8 output from this comparison circuit A32
0 is input to the output circuit 48.

On the other hand, the comparison signal generating circuit B44 generates a comparison signal B82 having a level slightly higher than the reference value of the side of the carton 1 to which no glue is attached. In other words, if the level value L is the standard level of the non-glued part of the carton, then the section 8 with a slightly higher value
Generate a signal with 2H. This section 82H
The height can be adjusted using an external setting device B46. In this embodiment, the timing signal 72 is input to the comparison signal generation circuit B44, and the comparison signal B82 (see FIG. 5G) is generated by shifting the timing signal 72 in the comparison signal generation circuit B44. By adjusting the height of this comparison signal B82 using an external setting device B46, the inspection sensitivity is adjusted and inspection errors are prevented.

This comparison signal B82 is input to the comparison circuit B42 and compared with the capacitance signal 74 (see FIG. 5H) to determine whether or not there is adhesive fading. That is, when the capacitance signal 74 becomes lower than the comparison signal B82, the level is high (8 (if the glue is smeared));
Otherwise, a 0 level determination signal B84 (see FIG. 5I) is output.

The determination signal A80 and the determination signal B84 are output from the output circuit 48.
The output circuit 48 obtains a logical sum, and the obtained signal is input to the AND gate circuit 52. In the AND gate circuit 52, when the timing signal 72 is at a high level and the signal from the output circuit 48 is at a high level (in other words, when the carton 1 is between the boards 11, the judgment signal A
80 or when a high level portion is present in the determination signal B84), a test signal 86 is generated which becomes a high level, and becomes a low level when at least one of them is a low level. That is, the high level portion 86 of this test signal 86
The H pulse corresponds to a portion with poor adhesive adhesion.

One of these test signals 86 is input to the counter 54. The counter 54 has a timing signal 72
is also input. In this counter 54, when a high level portion 86H of the inspection signal 86 exists in one section where the timing signal 72 is at a high level, it is counted as one carton with defective glue adhesion, and such a carton with defective glue adhesion is counted. When the number of consecutive defective sheets coincides with the number set in the continuous defective sheet number setting device 56, a signal is sent to the alarm A58 and a red lamp and a buzzer alert the operator.

Further, the test signal 86 and the timing signal 72 are input to the shift register 60, and in this shift register 60, when a high level portion 86H of the test signal 86 exists in one section where the timing signal 72 is high level, one sheet of It is counted as a carton with defective adhesive adhesion, and is shifted each time a signal indicating one carton with defective adhesive adhesion is received, and when the value matches the number set in the defective sheet number setting device 62 (in other words, the inspection When the number of cartons with defective glue adhesion after starting the process reaches the set number), a signal is sent to the alarm B64 and a red lamp and buzzer alert the operator.

In this way, when a predetermined number of cartons with defective adhesion occur continuously, or when the number of cartons with defective adhesion from the start of the inspection reaches a predetermined number, a red lamp and a buzzer alert the operator.

Since the present invention has the above structure, it has excellent practical effects as shown below.

That is, in the present invention, since the amount of glue adhered is detected electrostatically, the amount of glue present in the head can be accurately measured, and it is no longer suitable for conventional electro-optical inspection of colored glue. In comparison, even if the transport position of the carton shifts from side to side, measurement errors will not occur.
It is extremely easy to adjust before inspection for cartons of various shapes and sizes, and it is possible to accurately and reliably measure the amount of glue without being affected by the thickness of the glue, and identify cartons with poor glue adhesion without any inspection errors. Can be inspected.

In particular, since the capacitance detection level can be corrected using the matching trimmer installed in the inspection head, it is possible to uniformly adjust the capacitance detection level, which varies depending on the amount of glue and carton thickness for each product. Therefore, it is possible to inspect a wide variety of cartons.

[Brief explanation of the drawing]

The drawings show one embodiment of the present invention,
Fig. 1 is a plan view of the sensor head, Fig. 2 is a side view thereof, Fig. 3 is a front view thereof, Fig. 4 is a block diagram of this inspection device, and Fig. 5 is a signal diagram showing the inspection process. where A is a timing signal, B is a capacitance signal, C is a glue adhesion reference signal, and D is a comparison signal A, E.
represents the comparison between the capacitance signal and the comparison signal A, F represents the determination signal A, G represents the comparison signal B, H represents the comparison between the capacitance signal and comparison signal B, I represents the determination signal B, J
6 shows various cases of glue adhesion on the carton, A is a timing signal, B is normal, C is glue broken, D is glue smudged, E is
Each indicates a state of excessive contact. 1...Carton, 2...Glue allowance, 3...Glue, 10
...Inspection head, 11...Base, 13...Electrode plate,
14...Photo sensor, 17...Shield plate,
18... Spacing, 19... Hinge, 20... Capacitance sensor, 22... Matching trimmer, 24
...Capacitance generation circuit, 26 ...Amplification circuit, 28
... Rectifier circuit, 30 ... Sample hold circuit,
32...Comparison circuit A, 34...Reference level detection circuit, 36...Comparison signal generation circuit A, 38...External setter A, 42...Comparison circuit B, 44...Comparison signal generation circuit B, 46... ...External setting device B, 48...
Output circuit, 50... Timing signal generation circuit, 5
2...AND gate circuit, 54...Counter, 5
6...Continuous defective sheet number setting device, 58...Alarm A,
60...Shift register, 62...Defective sheet number setting device, 64...Alarm B, 72...Timing signal, 74...Capacitance signal, 76...Glue adhesion surface reference signal, 78...Comparison signal A , 80... Judgment signal A, 82... Comparison signal B, 84... Judgment signal B,
86...Inspection signal.

Claims (1)

[Scope of utility model registration request] This is a device that detects the capacitance inside the inspection head for measuring capacitance through the glue-attached part of the carton, which is the object to be inspected, and inspects the state of glue adhesion based on the obtained capacitance signal. The inspection head has two bases facing each other, and an electrode plate serving as a capacitance sensor is formed on the bases, and the glued portion of the carton to be detected is conveyed between the bases. The capacitance sensor is provided with a matching trimmer for adjusting the inspection level, so that when detecting capacitance with the inspection head, the detection level can be corrected. A circuit that obtains a capacitance signal corresponding to the capacitance between the pole plates based on a signal from a capacitance sensor, a circuit that generates a comparison signal B at a level slightly higher than the reference value of the non-glued side of the carton, A glue adhesion state inspection device characterized by comprising a comparison circuit B that compares the comparison signal B and the capacitance signal to determine whether glue is broken, glue is smudged, etc. .