JP2018072071A - Gluing inspection device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a gluing inspection device that has improved detection sensitivity, expanded a detection range, reduced variations, and the like.SOLUTION: A gluing inspection device includes a detection head that radiates electromagnetic waves at a high frequency to a glue applied to a non-conductive gluing object and receives electromagnetic waves that have gone through the glue, and inspects a gluing state by processing a signal received by the detection head. The detection head is formed with a printed circuit board, and on one face of the printed circuit board formed are two radiation electrodes arranged to radiate the electromagnetic waves and one reception electrode arranged in the middle of the two radiation electrodes for receiving the electromagnetic waves radiated by the two radiation electrodes.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a gluing inspection apparatus that inspects a gluing state of a non-conductive gluing object such as a corrugated cardboard or a carton to which a gluing is applied at a position away from the gluing object.

  In box making machines and collating machines that use corrugated cardboard and cartons, gluing is performed using a gluing nozzle and a gluing wheel in the gluing process. Is done.

  As the gluing inspection apparatus, the present applicant has proposed a gluing inspection apparatus 80 using electromagnetic waves as shown in FIG. 5 (Patent Document 1). In FIG. 5, reference numeral 81 denotes a gluing detection head. The radiation electrode 82A, the reference reception electrode 82B and the measurement reception electrode 82C arranged at equal intervals on both sides of the radiation electrode 82A, and the insulation surrounding the electrodes 82A to 82C, respectively. The body 83A, 83B, 83C and a metal shield case 84 that fixes and arranges the insulators 83A to 83C in a row so that the lower ends thereof partially protrude at the same level. A high frequency electromagnetic wave of about 500 kHz is applied from the oscillator 85 to the radiation electrode 82A, and the electromagnetic wave received by the reference reception electrode 82B and the measurement reception electrode 82C is taken into the detection circuit 86.

  Then, when the corrugated cardboard 30 having the lower surface coated with the adhesive 20 is conveyed in a direction perpendicular to the paper surface of FIG. 5, the corrugated cardboard 30 comes close to the lower surfaces of the radiation electrode 82A and the measurement receiving electrode 82C at intervals of about several millimeters. Then, the detection head 81 is positioned to detect the state of the glue 20.

  The electromagnetic wave radiated from the radiation electrode 82A is input to the reference reception electrode 82B and the measurement reception electrode 82C through the space. At this time, in the state of FIG. 5, the path of electromagnetic waves from the radiation electrode 82A to the measurement reception electrode 82C includes the paste 20, and the path of electromagnetic waves from the radiation electrode 82A to the measurement reception electrode 82C includes the paste 20. Absent. Since the paste 20 contains moisture, when the paste 20 is exposed to electromagnetic waves, an eddy current is generated there, and a large amount of power is consumed there. For this reason, the electromagnetic wave incident on the measurement receiving electrode 82C has a smaller energy than the electromagnetic wave incident on the reference receiving electrode 82B. The electromagnetic waves incident on the reference receiving electrode 82B and the measuring receiving electrode 52C are affected to the same extent by the influence of the atmosphere such as the temperature of the space and noise. Since the corrugated cardboard 30 is made of paper, the electromagnetic wave is hardly affected.

  Therefore, the detection circuit 86 detects the difference in signal intensity between the electromagnetic wave received by the measurement receiving electrode 82C and the electromagnetic wave received by the reference receiving electrode 82B, thereby canceling the influence of the atmosphere in the space and showing the pasting state. The signal can be taken out, and the application amount, application position, application length in the direction perpendicular to FIG.

JP-A-8-122280

  However, since the gluing inspection apparatus 80 described with reference to FIG. 5 detects the glue 20 only by the electromagnetic wave radiated from the radiation electrode 82A to the measurement reception electrode 82C, the detection sensitivity is limited, and the thickness of the cardboard 30 is large. When it is large, there is a problem that the state of the glue 20 on the lower surface of the corrugated cardboard 30 cannot be accurately detected. Further, when the paste 20 applied to the cardboard 30 is out of the space between the radiation electrode 82A and the measurement receiving electrode 82C, it cannot be detected, and the detection range is narrow. If the interval between the radiation electrode 82A and the measurement receiving electrode 82C is increased in order to widen the detection range, there is a problem that the detection sensitivity is lowered. Furthermore, at the stage of assembly, there is a problem that variations in the attachment positions of the reference reception electrode 82B and the measurement reception electrode 82C with respect to the radiation electrode 82A are likely to occur, resulting in variations in detection characteristics due to manufacturing variations.

  An object of the present invention is to provide a gluing inspection device that improves detection sensitivity, expands a detection range, reduces variation, and the like.

  In order to achieve the above object, an invention according to claim 1 includes a detection head that radiates high-frequency electromagnetic waves to glue applied to a non-conductive object to be glued and receives electromagnetic waves via the glue, In a gluing inspection apparatus that inspects a gluing state by processing a signal received by a detection head, the detection head is configured by a printed circuit board, and is disposed on one side of the printed circuit board so as to emit the electromagnetic wave. In addition, two radiation electrodes and one reception electrode arranged between the two radiation electrodes and receiving electromagnetic waves radiated from the two radiation electrodes are formed.

According to a second aspect of the present invention, in the gluing inspection apparatus according to the first aspect, a shield electrode is formed on the entire other surface of the printed board opposite to the one surface.
According to a third aspect of the present invention, in the gluing inspection apparatus according to the first or second aspect, the one surface of the printed circuit board is not in contact with the radiation electrode and the reception electrode around the radiation electrode and the reception electrode. And another shield electrode connected to the shield electrode on the other surface is formed.

  According to a fourth aspect of the present invention, in the gluing inspection apparatus according to any one of the first to third aspects, n (n is a positive integer of 1 or more) receiving electrodes on the one surface of the printed circuit board. And n + 1 radiating electrodes are alternately arranged and arranged in parallel at the same interval so that both ends thereof are the radiating electrodes.

  According to a fifth aspect of the present invention, in the gluing inspection apparatus according to any one of the first to fourth aspects, the detection head is in an opening formed on the lower surface of the shield housing in a posture in which the one surface is a lower surface. The opening is closed by a dielectric protective cover having a low dielectric constant.

  According to a sixth aspect of the present invention, in the gluing inspection apparatus according to any one of the first to fifth aspects, a signal indicating the gluing state is generated by processing an electromagnetic wave signal received by the receiving electrode. A detection circuit, the detection circuit comprising: comparing means for comparing an electromagnetic wave signal output from the receiving electrode when the glue is detected with an electromagnetic wave signal output from the receiving electrode when the glue is not detected; And the comparison means cancels the influence of the atmosphere around the glue.

  According to the present invention, since the detection head is composed of the printed circuit board, the manufacturing variation can be made almost zero, and the reliability can be improved. Moreover, since the detection range is between the radiation electrodes on both sides, the detection range can be expanded. In addition, since the receiving electrodes are arranged so that the receiving electrodes are sandwiched by the radiation electrodes, the intensity of electromagnetic waves that arrive at the receiving electrodes is increased, and the detection sensitivity can be increased. Since the radiation electrode and the reception electrode can be formed by copper foil printing, it is easy to increase the area thereof, and the detection sensitivity can be increased also in this aspect. Moreover, the detection sensitivity can be further increased by arranging the shield electrode on one side or the other side of the printed circuit board. As a result of increasing the detection sensitivity in this way, a detection signal of a necessary level can be obtained even if the detection head is placed slightly away from the object to be glued, and the glue object to be glued on the lower surface can be obtained. When the paste is inspected, the gluing inspection can be normally performed even if the thickness of the object to be glued is somewhat large.

It is an installation block diagram of the pasting inspection device and pasting device of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS It is a figure which shows the gluing test | inspection apparatus of 1st Example of this invention, (a) is sectional drawing, (b) is the bb sectional view taken on the line of (a). It is a block diagram of the detection circuit of the glue test | inspection apparatus of the Example. It is a figure which shows the detection head of the glue test | inspection apparatus of 2nd Example of this invention, (a) is sectional drawing, (b) is a bottom view. It is a block diagram of the conventional pasting inspection apparatus.

<First embodiment>
FIG. 1 shows a configuration in which a gluing device 50 and a gluing inspection device 10 of the present invention are installed along a guide plate 40. The guide plate 40 guides the corrugated cardboard 30 as an object to be glued, which is conveyed in the direction of arrow A by a conveyance belt (not shown) installed inside the guide plate 40, and is disposed at a portion where the gluing device 50 is disposed. A gluing opening 41 is formed.

  The gluing device 50 has a gluing pot 51 filled with gluing 20 and a lower surface immersed in the gluing 20 in the gluing pot 51, and an upper surface exposed to the gluing opening 41 of the guide plate 40. And a push wheel 53 for pressing the cardboard 30 placed on the paste wheel 52 against the paste wheel 52.

  The gluing inspection apparatus 10 is disposed downstream of the gluing apparatus 50, and a photoelectric sensor 60 that detects the cardboard 30 is disposed immediately before the gluing apparatus 10. On the lower surface of the photoelectric sensor 60, a guide 61 is formed that is cut obliquely so that the front end of the corrugated cardboard 30 flows smoothly into the lower surface of the gluing inspection apparatus 10. Reference numeral 70 denotes an encoder, which detects the conveyance amount of the cardboard 30 by the conveyance belt in the guide plate 40.

  FIG. 2 shows the gluing inspection apparatus 10. Reference numeral 11A denotes a detection head composed of a printed circuit board. On the lower surface of the insulating substrate 12, as shown in FIG. 2B, strip-shaped radiation electrodes 13A1 and 13A2 are perpendicular to the conveying direction A of the cardboard 30. A strip-shaped receiving electrode 13B having the same size is formed in parallel at the center of the radiation electrodes 13A1 and 13A2. A shield electrode 13C is formed on the entire surface around the electrodes 13A1, 13A2, and 13B so as not to contact the electrodes 13A1, 13A2, and 13B. The electrodes 13A1 and 13B and the electrodes 13A2 and 13B are separated from each other by the same distance L1. Reference numeral 14 denotes a shield electrode formed on the entire upper surface of the insulating substrate 12, and is connected to the lower shield electrode 13C. These electrodes 13A1, 13A2, 13B, 13C, and 14 are formed by copper foil printing.

  Reference numeral 15 denotes a protective cover formed of a dielectric material having a low dielectric constant such as Teflon (registered trademark) for protecting the electrodes 13A1, 13A2, 13B, and 13C on the lower surface of the detection head 11A. Reference numeral 16 denotes a grounded shield casing constituting at least a part of the casing of the gluing inspection apparatus 10, and the detection head 11A is arranged inside an opening 161 formed on the lower surface, and the lower surface of the opening 161 is a protective cover. It is closed at 15. The shield housing 16 is connected to the shield electrodes 13C and 14 of the detection head 11A. The radiation electrodes 13A1 and 13A2 are connected to an oscillator 17 that outputs a high-frequency signal of about 500 kHz, and the reception electrode 13B is connected to a detection circuit 18.

  When a high frequency signal of about 500 kHz is applied from the oscillator 17 to the radiation electrodes 13A1 and 13A2, electromagnetic waves are radiated from the radiation electrodes 13A1 and 13A2, and a part of the electromagnetic waves are reflected by the shield electrode 14 on the upper surface or the surrounding shield housing 16 is provided. After being reflected by the inner wall of the opening 161 and radiated downward, it is received by the receiving electrode 13B.

  At this time, a detection sensitivity characteristic is obtained such that the middle is the maximum sensitivity between the radiation electrode 13A1 and the reception electrode 13B, and the middle is the maximum sensitivity between the radiation electrode 13A2 and the reception electrode 13B. Sensitivity characteristics are obtained. Therefore, by appropriately setting the output power of the oscillator 17 and the mutual interval L1 between the electrodes 13A1, 13A2, and 13B, a substantially flat sensitivity characteristic can be obtained from the radiation electrode 13A1 to the radiation electrode 13A2 below the detection head 11A. Can be obtained.

  Thus, since the detection sensitivity is substantially flat from the radiation electrode 13A1 to the radiation electrode 13A2, the corrugated cardboard 30 with the adhesive 20 applied to the lower surface is perpendicular to the paper surface of FIG. 2A below the detection head 11A. This can be detected if the glue 20 enters between the radiation electrodes 13A1 and 13A2 on both sides when it is conveyed in a different direction.

  That is, the detection range in the direction B orthogonal to the conveyance direction A of the corrugated cardboard 30 can be doubled as compared with the case where one radiation electrode and one reception electrode are configured. For this reason, even if the application position of the glue 20 on the corrugated cardboard 30 is slightly deviated in the direction B perpendicular to the transport direction, the glued state can be detected normally.

  Further, since the radiation electrodes 13A1 and 13A2 are arranged on both sides of the reception electrode 13B, the power of the electromagnetic wave received by the reception electrode 13B is doubled as compared with the configuration in which the reception electrode 13B is received from one radiation electrode. Sensitivity is doubled.

  Further, the reception electrode 13B is surrounded by the radiation electrodes 13A1 and 13A2, the shield electrode 13C and the shield electrode 14 are formed, and the periphery of the detection head 11A is surrounded by the inner wall of the opening 161 of the shield housing 16. By being surrounded, the electromagnetic wave received by the receiving electrode 13B is less affected by external noise.

  For this reason, since the S / N ratio for detection is improved, the distance between the lower surface of the detection head 11A and the adhesive 20 can be increased, and the adhesive 20 is applied to the lower surface of the thick corrugated cardboard 30. Even so, the application amount, application position, application length, etc. of the glue 20 can be detected accurately.

  FIG. 3 shows details of the detection circuit 18. A pre-processing unit 181 outputs a signal a obtained by amplifying an electromagnetic wave signal received by the receiving electrode 13B of the detection head 11A to a predetermined level with a high S / N ratio by a preamplifier. This preamplifier is desirably installed in the vicinity of the detection head 11A.

  A timing processing unit 182 takes in a detection signal of the corrugated cardboard 30 obtained by the photoelectric sensor 60 and a pulse train from the encoder 70 generated when transported by a transport belt (not shown) into the timing processing unit 182, and the corrugated cardboard 30 is glued to the gluing inspection device 10. When the cardboard 30 is not transported below the gluing inspection apparatus 10, the corrugated cardboard timing signal b2 is validated.

  Reference numeral 183 denotes a first sampling processing unit, which outputs a signal c1 obtained by sampling the signal a obtained by the preprocessing unit 181 with a predetermined clock when the timing signal b1 with cardboard output from the timing processing unit 182 is valid. . This signal c1 may include an element indicating the detection of the glue 20.

  A second sampling processing unit 184 outputs a signal c2 obtained by sampling the signal a obtained by the preprocessing unit 181 with the clock when the cardboard-less timing signal b2 output from the timing processing unit 182 is valid. . This signal c2 does not include an element indicating the detection of the glue 20.

  Reference numeral 185 denotes an arithmetic processing unit which takes in the signal c1 output from the first sampling processing unit 183 and the signal c2 output from the second sampling processing unit 184, holds the signal c2 and compares the signal c1 with it. Thus, a signal d indicating the pasting state is generated.

  In this detection circuit 18, the signal a output from the preprocessing unit 181 is hardly affected by the presence or absence of the cardboard 30, but is affected by temperature fluctuations. Therefore, the signals c 1 and c 2 are similarly affected by temperature fluctuations. It becomes.

  Accordingly, the signal c2 output from the second sampling processing unit 184 is retained, and the signal c2 and the signal c1 output from the first sampling processing unit 183 are compared by the arithmetic processing unit 185, whereby the temperature variation It is possible to obtain a signal d in which the variation in the pasting state associated with is canceled. The influence of external noise can be canceled as well.

  As described above, the detection circuit 18 according to the present embodiment cancels the influence of temperature fluctuations and external noise on the detection result of the glued state even if the special reference reception electrode 82B described with reference to FIG. 5 is not provided. be able to.

<Second embodiment>
FIG. 4 shows a portion of the detection head 11B of the gluing inspection device of another embodiment. In the detection head 11B of the present embodiment, the radiation electrodes 13A1 and 13A2 are disposed on both sides in the B direction orthogonal to the traveling direction A of the corrugated cardboard 30 on the lower surface, the radiation electrode 13A3 is disposed at the center, and the radiation electrode 13A1. , 13A3, the receiving electrode 13B1 is disposed, and the receiving electrode 13B2 is also disposed between the radiation electrodes 13A2, 13A3. Others are the same as the content demonstrated in FIG.

  Since the detection head 11B of the present embodiment uses the three radiation electrodes 13A1 to 13A3, the loss of the electromagnetic wave radiated from the inner radiation electrode 13A3 is the loss of the electromagnetic wave radiated from the outer radiation electrodes 13A1 and 13A2. Compared to this, the sensitivity becomes higher. In addition, it becomes possible to set the region between the radiation electrode 13A1 and the radiation electrode 13A2 to have substantially uniform detection sensitivity, and the detection range is expanded four times as compared with the case where there is one radiation electrode and one reception electrode. Can do.

  If the detection head 11B of the second embodiment is advanced so that the number of reception electrodes is n (n is a positive integer equal to or greater than 1), the number of radiation electrodes is n + 1, so the detection range is 2n times. Become.

10: Glue inspection device, 11A, 11B: detection head, 12: insulating substrate, 13A1, 13A2, 13A3: radiation electrode, 13B, 13B1, 13B2: reception electrode, 13C: shield electrode, 14: shield electrode, 15: protective cover , 16: Shield housing 20: Glue 30: Corrugated cardboard 40: Guide plate 50: Glue device, 51: Glue pot, 52: Glue wheel, 53: Presser wheel 60: Photoelectric sensor, 61: Guide 70: Encoder 80: Glue device , 81: detection head, 82A: radiation electrode, 82B: reference reception electrode, 82C: measurement reception electrode, 83A to 83C: insulator

Claims (6)

A state of pasting by processing a signal received by the detection head, including a detection head that radiates high-frequency electromagnetic waves to the paste applied to the non-conductive pasting object and receives electromagnetic waves via the paste. In the gluing inspection device that inspects
The detection head is constituted by a printed circuit board, and on one surface of the printed circuit board, two radiation electrodes arranged to radiate the electromagnetic wave, and the two radiation electrodes arranged between the two radiation electrodes. A gluing inspection device, wherein one receiving electrode for receiving an electromagnetic wave radiated from a radiating electrode is formed. In the gluing inspection device according to claim 1,
A gluing inspection apparatus, wherein a shield electrode is formed on the entire other surface of the printed circuit board opposite to the one surface. In the gluing inspection device according to claim 1 or 2,
On one side of the printed circuit board, another shield electrode is formed around the radiation electrode and the reception electrode in a non-contact manner with the radiation electrode and the reception electrode and connected to the shield electrode on the other surface. A gluing inspection device characterized by being made. In the gluing inspection device according to any one of claims 1 to 3,
On one side of the printed circuit board, n (n is a positive integer greater than or equal to 1) reception electrodes and n + 1 radiation electrodes are arranged alternately and parallel at the same interval so that both ends are the radiation electrodes. A gluing inspection device characterized in that it is arranged and formed on the surface. In the pasting inspection device according to any one of claims 1 to 4,
The detection head is disposed in an opening formed in the lower surface of the shield housing in such a posture that the one surface is a lower surface, and the opening is closed by a dielectric protective cover having a low dielectric constant. Glue inspection device. In the gluing inspection device according to any one of claims 1 to 5,
A detection circuit that processes a signal of an electromagnetic wave received by the reception electrode to generate a signal indicating the pasting state;
The detection circuit includes a comparison unit that compares an electromagnetic wave signal output from the receiving electrode when the glue is detected with an electromagnetic wave signal output from the receiving electrode when the glue is not detected, The gluing inspection apparatus characterized in that the influence of the atmosphere around the glue is canceled by the means.

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