JP2018169289A - Device for inspecting internal pressure of hermetic container - Google Patents

Abstract

To provide an internal pressure inspection device capable of inspecting and determining whether internal pressure of a hermetic container is good or not and whether the hermetic container is defective or not in a comprehensive and accurate manner regardless of contents of the container.SOLUTION: An internal pressure inspection device comprises: a striking unit; a laser sensor; an integration unit 15 configured to integrate displacements within a predetermined range of a lid of a hermetic container to derive an integrated value; a first determination unit 17 configured to determine whether internal pressure is good or not based on the integrated value derived by the integration unit 15; a waveform computation unit 16 configured to derive a vibration waveform corresponding to vibration of the lid from displacements in another predetermined range of the lid; a second determination unit 18 configured to determine whether the internal pressure is good or not based on the vibration waveform derived by the waveform computation unit 16; and a comprehensive determination unit 19 configured to determine whether the hermetic container is defective or not based on a determination result of the first determination unit 17 and a determination result of the second determination unit 18.SELECTED DRAWING: Figure 3

Description

  The present invention relates to an apparatus for inspecting an internal pressure of a sealed container such as a three-piece can or a bottle-type can, and more particularly to an internal pressure inspection apparatus for a metal can.

  The internal pressure of cans such as beverages and foods changes depending on whether the container is sealed or not, the contents are altered or rotted. As a method for determining whether a can product is good or defective, a method using acoustic characteristics is conventionally known. One example is that a striking force by an electromagnetic coil or the like is applied to the lid (canopy or bottom lid) of a can (that is, a sealed container) that is filled with the contents and sealed by the lid, and the vibration of the lid is caused by a microphone as sound. In this method, the frequency (frequency of the maximum amplitude) is compared with a reference value prepared in advance as a determination criterion, and whether the internal pressure of the sealed container is good or not is determined as a product.

  In such an inspection method based on the vibration of the lid, the contents of the sealed container are greatly affected, and the determination accuracy or inspection accuracy may be lowered. That is, if the content contains solids or the content is a viscous material with high viscosity, the sealed container with the solids or viscous material attached to the inner surface of the lid and the non-adhered seal The container will be mixed. The reference value such as frequency to be prepared as the standard for judgment is usually the value when no solid content or viscous material is attached, so the sealed container with the solid content or viscous material attached to the inner surface of the lid When there is a mixture of non-adhered sealed containers, the internal pressure is normal, but the vibration of the lid is different from the normal vibration due to the contents adhering to it. Or the frequency of misjudging as a defective product increases.

  On the other hand, when the internal pressure of the negative pressure can is increased due to the alteration of the contents or the decay (when the negative pressure is insufficient), the deformation of the dent of the lid is reduced as compared with a normal one. A device for inspecting the internal pressure using such characteristics is described in Patent Document 1. The apparatus described in Patent Literature 1 arranges a laser displacement sensor toward the lid of a sealed container that is linearly conveyed in a predetermined direction, and detects the displacement amount of the lid along the diameter direction of the lid, for example. Then, by integrating the detected values, the integrated value of the amount of displacement from the predetermined reference line, that is, the area of the depression that is recessed from the reference line is obtained, and the reference value that is prepared as the criterion It is comprised so that the quality of an internal pressure may be determined compared with.

  As the laser beam, a laser beam having a spot diameter of several tens to several hundreds of μm is generally used, but the laser beam such as black is not reflected on the lid of the sealed container irradiated with the laser beam. When printing is performed, the laser beam is not reflected at the printed portion, or the amount of reflected light is reduced. In such a portion, the displacement amount is large, and this becomes a cause of erroneous determination. Therefore, in the apparatus described in Patent Document 2, two laser sensors are arranged side by side with respect to the conveying direction of the sealed container so that the displacement amount of the position avoiding the above-mentioned printing location is detected at the same time. It is composed.

JP 2013-96709 A Japanese Patent Laid-Open No. 2006-142670

  According to the apparatus that obtains the displacement amount of the lid by the laser displacement sensor described in Patent Document 1 and determines the quality of the internal pressure based on the integrated value of the displacement amount, it is accurate without being affected by the contents. It is possible to determine whether the internal pressure is good or not. However, while the sealed container to be inspected is conveyed by, for example, a conveyor and vibrates, the laser displacement sensor is fixed, so the lid and the laser displacement sensor due to the vibration of the sealed container are fixed. Is detected as the displacement amount of the lid, which may reduce the detection accuracy of the displacement amount and the determination accuracy of the internal pressure. In particular, in the case of a sealed container (canned food) that is less affected by the contents adhering to the lid and the contents adhering to the lid, it is better to strike the lid and determine whether the internal pressure is good or not based on the vibration. The accuracy of determination is better than determining the quality of the internal pressure by determining the amount of displacement of the lid and its integrated value using. In other words, a device that uses laser light to determine the amount of displacement of the lid and its integrated value is effective for sealed containers that are affected by the contents, and is blown for sealed containers that are not affected by the contents. Although an apparatus for inspecting the internal pressure based on the vibration caused by the above is effective, an internal pressure inspection apparatus that can be applied to both a sealed container that is affected by the contents and a sealed container that is not affected by the contents is conventionally known. Absent.

  Moreover, according to the apparatus described in Patent Document 2, it is possible to avoid or suppress a decrease in the accuracy of determination of the internal pressure of the sealed container caused by printing that absorbs laser light or has little reflected light. However, since the required number of sensors and the amount of data to be processed increase, the cost of the entire device increases, and there is room for improvement in terms of cost reduction and simplification of the device.

  The present invention has been made against the background of the above circumstances. Regardless of the contents, the internal pressure of the sealed container and the internal pressure capable of comprehensively and accurately performing inspection and determination of non-defective / defective products of the sealed container. The object is to provide an inspection device.

  In order to achieve the above object, the present invention provides an internal pressure inspection device for a sealed container having a lid portion that is deformed according to an internal pressure and vibrates in response to a striking force. A striking part that causes vibration in the part, a laser type sensor that irradiates the lid part with laser light to detect a displacement amount of the lid part, and a displacement detected by the laser type sensor in a predetermined range in the lid part An integrating unit that integrates the amount to determine an integrated value, a first determining unit that determines whether the internal pressure of the sealed container is good based on the integrated value obtained by the integrating unit, and another predetermined range in the lid unit A waveform calculation unit for obtaining a vibration waveform corresponding to the vibration of the lid by the amount of displacement detected by the laser sensor, and an internal pressure of the sealed container based on the vibration waveform obtained by the waveform calculation unit Judge the quality of A second determination unit; and a comprehensive determination unit that determines a non-defective product or a defective product of the sealed container based on a determination result by the first determination unit and a determination result by the second determination unit. It is what.

  In the present invention, the striking part and the laser type sensor are arranged to face the lid part of the sealed container that is continuously conveyed in a predetermined direction with a predetermined interval, and the integrating part is The waveform calculation unit obtains the integrated value by integrating the amount of displacement detected when the sealed container is moving relative to the laser sensor, and the waveform calculation unit is configured such that the sealed container is the laser sensor. A vibration waveform corresponding to the vibration may be obtained based on the amount of displacement detected when moving relative to the movement.

  In the present invention, the striking part has an annular electromagnetic coil disposed on the same axis as the central axis of the sealed container and facing the lid part, and the laser sensor transmits the laser light, You may be comprised so that the inside of an electromagnetic coil may be passed, and the said cover part may be irradiated, and the reflected light reflected by the said cover part may be received.

  In the present invention, the laser type sensor is configured such that the shape of the spot, which is the shape of the laser beam on the surface of the lid portion, of the laser beam irradiated on the lid portion intersects the transport direction of the sealed container. You may be comprised so that it may become a long shape.

  In the present invention, the shape that is long in the direction intersecting the transport direction of the sealed container may be a shape in which a plurality of circular shapes are closely arranged in a direction intersecting the transport direction of the sealed container.

  According to the present invention, the displacement amount of the lid portion struck and vibrated by the striking portion is detected by the laser sensor, and the integrated value of the displacement amount of the lid portion is detected based on the detection result (detection signal or data). , And a vibration waveform. The quality of the internal pressure of the sealed container is determined based on the integrated value, the quality of the internal pressure of the sealed container is determined based on the vibration waveform, and the quality of the sealed container is determined based on each determination result. Done. That is, according to the present invention, only one detection result may be used when performing the two determinations, i.e., determination of whether the internal pressure is good based on the integrated value of the displacement, and determination of whether the internal pressure is good based on the vibration waveform. By reducing the number of sensors and the amount of data to be processed, the overall cost of the apparatus can be reduced. In addition, since data processing is facilitated, accurate and stable inspection can be performed even if the inspection speed is increased as the conveyance speed of the sealed container is increased. In particular, so-called percussion means for detecting the vibration of the lid as a sound wave and making a determination based on the waveform, and a laser displacement sensor are arranged side by side in the transport direction of the sealed container, and two determinations are made. Compared with the device, in such a device, there is a time difference between the detection timing of the percussion means and the laser displacement sensor, so the data obtained by either one is temporarily stored, and the subsequent data is waited for Judgment. Therefore, if the inspection speed is increased along with the increase in the transport speed of the sealed container, it is necessary to increase the data processing speed, and the arithmetic unit and the program become complicated or enormous, resulting in higher cost of the apparatus. In addition, the determination accuracy or inspection accuracy may become unstable. On the other hand, according to the apparatus of the present invention, such inconvenience can be solved.

  Further, in the present invention, the vibration of the lid can be detected without mediating the sound, so that it is affected by the resonance phenomenon and disturbance noise generated in the waveguide (tube) that guides the conventional canned sound to the microphone. Therefore, the internal pressure can be determined without increasing the internal pressure determination or inspection accuracy.

  Furthermore, in the present invention, even if laser light is used, the laser light spot shape is long in the direction intersecting the sealed container transport direction (trace direction by the laser light). An average displacement amount of a predetermined area including a place where printing that absorbs or reduces reflected light is performed can be obtained, and detection errors due to printing can be eliminated or reduced. In particular, even if the spot shape of the laser beam is long, it is long in the direction intersecting the transport direction of the sealed container, so the amount of displacement in the direction of tracing the laser beam is not averaged. In this respect as well, the displacement detection accuracy and the internal pressure determination or inspection accuracy can be improved.

It is a figure for demonstrating an example of a structure of the internal pressure test | inspection apparatus which concerns on this invention, and an example of the shape of the spot of a laser beam. It is sectional drawing which shows an example of the shape of a bottom cover typically. It is a block diagram for demonstrating the structure of a controller. It is a flowchart for demonstrating the procedure or method of the internal pressure test | inspection by the internal pressure test | inspection apparatus which concerns on this invention. It is a figure which shows typically the data which detected the area which is the integrated value of displacement, and the vibration of the bottom cover. It is a figure which shows the vibration waveform based on the displacement of the bottom cover detected by the laser type sensor. It is the figure which processed the vibration waveform of the bottom cover shown in FIG. 6 by FFT.

  The internal pressure inspection apparatus according to the present invention determines the internal pressure of a sealed container (sealed container) such as a negative pressure can that has a pressure lower than atmospheric pressure, and checks whether the sealed container is a good product or a defective product. Device. The sealed container to be inspected has a lid on at least one of the upper and lower sides, and the lid bends inward due to the negative internal pressure, and the amount of deflection (displacement) is the internal pressure. And is so-called thin plate-shaped and configured to vibrate when hit. An example of this type of sealed container is a canned food containing a viscous product (high-viscosity product) such as a beverage or solid juice containing solids, or a cooked product. The lid portion may be provided on both the upper and lower sides, or may be either the canopy or the bottom lid. For example, a bottle-type can in which a cap is attached to the mouth portion with a screw and a bottom portion is closed with a lid may be used. In any of these sealed containers, the quality of the internal pressure is determined by the displacement and vibration of the lid.

  FIG. 1 shows an example of the present invention in which a bottle-shaped can 1 is configured as an inspection target. The bottle-shaped can 1 shown in FIG. 1 is placed on the conveyor 2 in an inverted state and is conveyed linearly in a certain direction. This bottle-shaped can 1 is made of magnetic metal, and a cap 4 is screwed to a mouth part formed on one end side (lower side in an inverted state) of the can body 3 to seal the mouth part. The cap 4 is inverted by bringing it into contact with the conveyor 2. The bottom (upper part in the inverted state) is sealed with a bottom lid 5 corresponding to the lid in the present invention.

  FIG. 2 is a schematic cross-sectional view showing the shape of the bottom lid 5. The bottom lid 5 has a circular shape as a whole, and is wound around the can body 3 by the curled portion 6 at the peripheral edge thereof. And integrated. A central portion of the bottom cover 5 is a panel portion 7, and an annular groove 8 for reinforcement is formed in the outer peripheral portion of the panel portion 7 (a portion between the curled portion 6). When the bottle-type can 1 is a negative pressure can, the panel portion 7 bends inward (toward the lower side in FIG. 2) from the boundary portion (corner portion) 9 with the annular groove 8 which is the outer peripheral edge thereof, For example, the amount of displacement when the corner portion 9 is the reference position is an amount corresponding to the internal pressure.

  An electromagnetic coil 10 is arranged at a predetermined location in the conveying direction of the bottle-shaped can 1 by the conveyor 2. The electromagnetic coil 10 is for generating a magnetic field when energized to give a striking force to the bottom lid 5 of the bottle-type can 1 and corresponds to a striking portion in the present invention. In the example shown in FIG. 1, the electromagnetic coil 10 has an annular shape whose outer diameter is about the outer diameter of the bottle-shaped can 1, and is arranged at a position spaced apart from the bottle-shaped can 1 on the conveyor 2. Yes. The arrangement position is preferably directly above the bottle-shaped can 1 on the conveyor 2, and the position of the electromagnetic coil 10 is determined so that the central axis of the bottle-shaped can 1 and the central axis of the electromagnetic coil 10 coincide. preferable.

  Laser type sensor that measures the distance to the bottom lid 5 by irradiating the upper side of the electromagnetic coil 10 with laser light toward the bottom lid 5 of the bottle-shaped can 1 on the conveyor 2 and receiving the reflected light. 11 is arranged. The laser sensor 11 may be a Doppler sensor. The laser sensor 11 only needs to be able to irradiate the laser beam toward the bottom lid 5 struck by the electromagnetic coil 10 and receive the reflected light. Therefore, the laser sensor 11 is disposed downstream of the electromagnetic coil 10 in the conveying direction of the bottle-shaped can 1. They may be arranged side by side. In the example shown in FIG. 1, the laser sensor 11 is arranged directly above the electromagnetic coil 10 and downward (towards the bottle-shaped can 1), and the irradiation light and the reflected light are formed in an annular shape. It is configured to pass through the inside.

  The spot shape of the laser light irradiated on the surface of the bottom lid 5 by the laser sensor 11 will be described. The shape of the spot S by the laser sensor 11 is a long shape as shown in FIG. Yes. More specifically, it has a shape in which a large number of circular spots of several tens μm to hundreds of tens μm are closely arranged on a straight line. As an example, it is a horizontally long shape with a vertical and horizontal dimension of about 120 μm × 1700 μm. This horizontally long shape is a shape that is long in the direction intersecting the transport direction F of the bottle-shaped can 1 as shown in FIG. This is because the influence of printing or the like is reduced by tracing the bottom lid 5 with a certain width. That is, even if printing that absorbs laser light or reduces reflection is present on the surface of the bottom lid 5, an average value can be obtained by measuring a certain wide area including the part where the printing is removed. , The influence of printing can be suppressed. In particular, since the spot S is long in the direction intersecting the transport direction F, it is possible to avoid averaging the amount of displacement in the direction traced by the laser beam (direction to be measured), and the measurement accuracy or determination accuracy is reduced. Can be avoided or suppressed.

  A timing sensor 12 is provided that detects that the bottle-type can 1 has reached a location where the internal pressure should be inspected and outputs a signal. In the example shown in FIG. 1, the timing sensor 12 is composed of a light emitter 12a and a light receiver 12b that receives light from the light emitter 12a, and the light emitted from the light emitter 12a to the light receiver 12b is a bottle-shaped can. When 1 is blocked, the voltage or current in the light receiver 12b changes, and the change is output as a detection signal. The installation position of the timing sensor 12 includes the conveyance speed of the bottle-type can 1 by the conveyor 2, the outer diameter of the bottle-type can 1, the timing when the electromagnetic coil 10 is energized, the timing when the laser sensor 11 emits laser light, and the laser. It can be determined as appropriate in relation to the timing at which the sensor 11 captures detection data. In addition, the timing sensor 12 is installed in the position which detects arrival of the bottle type can 1 before the center part of the bottle type can 1 reaches the center part of the electromagnetic coil 10 or the laser type sensor 11. In other words, according to the installation position of the timing sensor 12 and the conveyance speed of the bottle-type can 1, the timing for energizing the electromagnetic coil 10, the timing for the laser sensor 11 to emit laser light, or the timing for capturing detection data can be determined. Good. Note that the timing sensor 12 only needs to be able to detect the arrival of the bottle-shaped can 1 and may be a sensor other than the optical sensor described above.

  Although FIG. 1 does not show a configuration for holding the electromagnetic coil 10, the laser type sensor 11, the timing sensor 12, and the like described above at predetermined positions, these members are arranged from the support provided on the side of the conveyor 2 to the arm. May be attached to the arm, or a gate-shaped frame may be provided so as to straddle the conveyor 2 and attached to the frame.

  The electromagnetic coil 10, the laser sensor 11, and the timing sensor 12 are connected to the controller 13, and the controller 13 performs on / off control, data acquisition, processing of the acquired data, output of a control command signal as a processing result, and the like. Is configured to do. The controller 13 is composed mainly of a microcomputer, for example, and is configured to process input data or prestored data in accordance with a preinstalled program and output the processed result as a control command signal. Has been. FIG. 3 is a block diagram showing the functional configuration of the controller, which includes an input unit 14 for reading the detection signal output from the laser sensor 11 and the detection signal output from the timing sensor 12. The input unit 14 includes a converter that converts an analog signal into a digital signal. An integration unit 15 that calculates an integrated value (area) of the displacement amount of the bottom lid 5 based on the signal processed by the input unit 14; a waveform calculation unit 16 that calculates a vibration waveform based on the signal processed by the input unit 14; It has. That is, it is configured to simultaneously obtain two data of the integrated value of the displacement amount of the bottom lid 5 and the vibration waveform based on one detection signal.

  A first determination unit 17 is provided for determining whether the internal pressure of the bottle-type can 1 is good or bad based on the integrated value obtained by the integrating unit 15. The first determination unit 17 stores in advance an integrated value range (reference range) when the internal pressure is appropriate. When the integrated value obtained by the integrating unit 15 is within the reference range, When the internal pressure is determined to be “good” and, on the contrary, outside the reference range, the internal pressure is determined to be “bad”.

  Moreover, the 2nd determination part 18 which determines the quality of the internal pressure of the bottle-type can 1 based on the vibration waveform calculated | required by the waveform calculation part 16 is provided. One of the waveform calculation unit 16 and the second determination unit 18 includes, for example, a fast Fourier transformer (FFT), and the second determination unit 18 is based on the vibration data processed by the FFT. The internal pressure is determined to be good or bad. For example, by comparing the amplitude of a specific frequency with a reference value prepared in advance, or comparing the frequency of the maximum amplitude with a reference value prepared in advance, the internal pressure is “good” or “bad”. It is configured to make a determination.

  Based on the determination result of the first determination unit 17 and the determination result of the second determination unit 18, an overall determination unit 19 that determines whether the bottle-type can 1 is a non-defective product or a defective product is provided. The overall determination unit 19 determines “good” when the determination results of the first and second determination units 17 and 18 are “good”, or either of the first and second determination units 17 and 18. If the determination result is “good”, the determination result of the first determination unit 17 and the determination result of the second determination unit 18 are selected by selecting “good” or “defective product”. It is comprised so that determination may be performed. In other words, the suitability of the internal pressure inspection method based on the vibration of the bottom lid 5 and the internal pressure inspection method based on the integrated value of the displacement amount of the bottom lid 5 is appropriate for the sealed container to be inspected (for example, the bottle-type can 1). Since it differs depending on the contents, it is configured to be able to select a determination result to be used for final determination of “good” and “defective”. Of course, it can be configured so that the “good” determination is performed only when the determination results of the first and second determination units 17 and 18 are both “good”.

  The striking force with respect to the bottom lid 5 is the time when the bottle-shaped can 1 reaches just below the electromagnetic coil 10, and at that time, a current is passed through the electromagnetic coil 10 at once. A driver 20 for this purpose is provided in the controller 13.

  Next, the operation of the above-described internal pressure inspection apparatus, that is, the internal pressure inspection method for the bottle-type can 1 will be described. FIG. 4 is a flowchart for explaining an inspection procedure or method executed by the internal pressure inspection device (particularly, the controller 13 described above). When the entire line including the conveyor 2 is activated, the routine of FIG. 4 starts simultaneously. To do. When the bottle-shaped cans 1 on the conveyor 2 reach the location of the timing sensor 12, the timing sensor 12 is turned on to output a signal (step S1). At that time, the laser-type sensor 11 is operating, irradiating laser light downward through the hollow portion of the electromagnetic coil 10, and measuring the distance by capturing the reflected light. The measurement signal is converted into a digital signal by the A / D converter (step S2).

  Since the bottle-shaped can 1 to be inspected is continuously conveyed by the conveyor 2, the laser sensor 11 irradiates the surface of the bottom cover 5 with a laser beam along a straight line passing through the center or a straight line close thereto. Thus, the distance to the bottom cover 5 is measured while tracing with such laser light along the straight line. Data (samples) thus obtained is read (step S3).

  When the bottle-type can 1 reaches a predetermined position relative to the electromagnetic coil 10, the can lid (bottom lid 5) is hit (canned) (step S4). The impact by the electromagnetic force of the bottom cover 5 is performed by generating a large magnetic field instantaneously by the electromagnetic coil 10. For example, the timing sensor 12 detects the bottle-shaped can 1 and starts charging the capacitor. After the charging is completed, the capacitor is discharged from the capacitor toward the electromagnetic coil 10 and is instantaneously generated by the electromagnetic coil 10. Generate a large magnetic field. By doing so, a suction force in the direction of pulling up the bottom lid 5 is instantaneously applied to the bottom lid 5, and this acts as a striking force to vibrate the bottom lid 5. Since the bottom lid 5 is wound around the can body 3 around the entire circumference, the center portion thereof is most easily deformed or vibrated. Accordingly, in order to effectively give a striking force to the center portion of the bottom lid 5, the electromagnetic current is applied to the electromagnetic coil 10 when the bottle-type can 1 reaches a position of a predetermined size and near the center of the electromagnetic coil 10, and electromagnetic Generate power. For example, when the conveyance speed of the bottle-shaped can 1 is 60 m / min, it is preferable to hit with the electromagnetic coil 10 when the bottle-shaped can 1 reaches a position about 0 mm to 5 mm before the center of the electromagnetic coil 10.

  At this point in time, the measurement by the laser sensor 11 is performed, and the remaining data (sample) in the bottom cover 5 is read (step S5). As an example, 1000 data (samples) are read (step S6). ), The reading of data used for the determination described below is completed. The data thus read is digitally converted by the A / D converter (step S7), and then two determinations are made using the data.

  Since the distance measured by the laser sensor 11 is, for example, the distance from the laser sensor 11 to the surface of the bottom cover 5, the displacement amount of the panel portion 7 deformed by the internal pressure is as shown in FIG. The corner portion 9 can be the origin (0 point) and can be obtained as the amount of depression from here. If a predetermined range is set between two points facing each other in the diameter direction of the corner portion 9, the integrated value of the displacement amount in the predetermined range is the area A of the portion indicated by hatching in FIG. . This represents the amount of displacement of the panel unit 7 as a whole. The integrating unit 15 described above calculates the area as the displacement amount in this way (step S8). The data used for calculating the area in this way is data including a change in the bottom lid 5 that is vibrating due to the impact, and the calculated integrated value includes the displacement due to such vibration. It is out. Since the so-called vibration component is a component that increases the amount of displacement and a component that decreases the amount of displacement, these components cancel each other. Therefore, there is no great difference between the integrated value of the displacement amount of the vibrating bottom lid 5 and the integrated value of the displacement amount of the lid portion that is not vibrated, and vibration hardly causes an error of the integrated value. In determining the integrated value, before the integration, the detection signal obtained by the laser sensor 11 may be filtered to remove the vibration component, and the subsequent displacement amount may be integrated to determine the integrated value.

  The internal pressure of the bottle-type can 1 is set so as to fall within a reference range determined by design. Therefore, the integrated value as the displacement amount of the panel portion 7 in the non-defective bottle-type can 1 is a value corresponding to the reference range. It becomes. Therefore, the quality of the internal pressure can be determined by comparing the area obtained in step S8 with a predetermined reference range. In step S9, whether the internal pressure is good or not is determined based on the integrated value of the displacement.

  On the other hand, since the data digitally converted in step S7 is obtained by measuring the displacement of the bottom lid 5 vibrating by striking, for example, as shown in FIG. If the vertical axis is expressed as displacement (amplitude) as time, a vibration waveform can be obtained. One example is schematically shown in FIG. By processing this with FFT, an amplitude for each frequency is obtained. One example is schematically shown in FIG. The original data for obtaining the vibration waveform is data obtained by optically obtaining the vibration of the bottom cover 5 and is not based on sound that is air vibration. Therefore, the obtained data and vibration waveform are not subjected to disturbances such as resonance and environmental noise, and thus are vibration waveforms accurately reflecting the vibration of the bottom cover 5.

  The vibration of the bottom lid 5 varies depending on the internal pressure, and if the internal pressure is within an appropriate range determined by design, the frequency at which a specific frequency falls within a predetermined range or a frequency at which the maximum amplitude is reached. Enter the predetermined frequency range. Such an amplitude or frequency in a non-defective product is prepared in advance as a reference value, and the quality of the internal pressure can be determined by comparing the vibration waveform obtained in step S10 with the reference value. In step S11, the quality of the internal pressure is determined based on the vibration waveform in this way.

  It should be noted that the manner of vibration differs between the central portion and the peripheral portion (portion close to the corner portion 9) of the bottom lid 5. Moreover, the measurement by the laser sensor 11 is performed in a state where the bottle-type can 1 is continuously conveyed, and therefore a series of data obtained by the laser sensor 11 includes data on different portions. For this reason, it is preferable that the vibration waveform and the data (sample) used for determining the internal pressure based on the vibration waveform are data of locations where the vibration method is substantially the same or approximate. Therefore, in the present invention, it is preferable to adopt data in a time zone of 5 ms to 10 ms from the center of the bottom lid 5 as data for calculating the vibration waveform. In this way, data collection for a limited area is performed, for example, when a predetermined time has elapsed from the time when the timing sensor 12 detects the bottle-shaped can 1 described above, and the radius is 5 mm (diameter is 10 mm). Data may be cut out with the time after the bottle-shaped can 1 has moved in the range as the end of collection.

  Based on the determination result obtained in step S9 and the determination result obtained in step S11, a comprehensive determination of the bottle-type can 1 is performed (step S12). Depending on the contents of the sealed container (bottle-type can 1) that is the object to be inspected, the accuracy of determination based on the integrated value is better than the accuracy of determination based on the vibration waveform, or the accuracy of determination is reversed. . Therefore, depending on the contents of the bottle-shaped can 1, it is determined in advance that the determination result in step S9 or the determination result in step S11 is adopted as the main determination result, or both determination results are adopted. In step S12, “good” or “defective” of the bottle-type can 1 is determined according to the adoption criteria for the determination result.

  The comprehensive determination result obtained in this way is identified (linked) so as to be the determination result for the bottle-type can 1 detected by the timing sensor 12 described above. When the bottle can 1 thus provided with the comprehensive determination result reaches an exclusion mechanism (not shown) arranged on the downstream side in the transport direction, the bottle can can is selected according to the comprehensive determination result. 1 is sent as it is on the transfer line or is removed from the transfer line.

  As described above, the internal pressure inspection apparatus according to the present invention linearly traces the lid of a sealed container such as the bottle-type can 1 with laser light to acquire data corresponding to the shape of the lid, and the data The amount of displacement of the lid portion and its integrated value are obtained based on the above, and the vibration of the lid portion due to impact is obtained as a vibration waveform from the data. That is, based on one data obtained by the laser type sensor 11, two determinations, that is, a determination based on a displacement amount and a determination based on vibration can be performed. Therefore, according to the present invention, not only can the number of sensors be reduced, but the amount of data to be processed can be reduced, and the overall configuration of the apparatus can be simplified and reduced in price. In particular, when compared with a device having a configuration in which a detector that detects vibration as sound and a detector that optically detects the amount of displacement are arranged in the conveying direction of the sealed container, this type of device uses a preceding detector. The data processing is extremely complicated because it is necessary to perform detection by the subsequent detector while the detection result is held, whereas in the internal pressure inspection device according to the present invention, the data is acquired by the sensor. Since the data is one for one sealed container, data processing and calculation means for that can be simplified.

  The present invention is not limited to the specific examples described above, and the sealed container may be a canned container or a synthetic resin container other than the bottle-shaped can 1 described above. When the synthetic resin container is to be inspected, the synthetic resin container may be vibrated by the striking means replaced with the electromagnetic coil 11, and the vibration may be detected by the laser sensor. The lid portion of the present invention is a portion of the upper plate or the lower plate that seals the upper end portion or the lower end portion of the trunk portion. Therefore, the lid portion of the present invention is a lid that is attached to the trunk portion by winding or the like. The bottom part of the flat form etc. which are integrated with a trunk | drum part like 2 piece cans is included.

  DESCRIPTION OF SYMBOLS 1 ... Bottle type can, 2 ... Conveyor, 5 ... Bottom cover, 6 ... Curl part, 7 ... Panel part, 8 ... Annular groove, 10 ... Electromagnetic coil, 11 ... Laser sensor, 12 ... Timing sensor, 13 ... Controller, DESCRIPTION OF SYMBOLS 14 ... Input part, 15 ... Accumulation part, 16 ... Waveform calculation part, 17 ... Determination part, 18 ... Determination part, 19 ... Comprehensive determination part, 20 ... Driver, F ... Conveyance direction, S ... (Laser light) spot.

Claims (5)

In an internal pressure inspection device for a sealed container having a lid portion that deforms in response to internal pressure and vibrates in response to impact force,
A striking portion that applies striking force to the lid portion and causes the lid portion to vibrate;
A laser-type sensor that detects the amount of displacement of the lid by irradiating the lid with laser light; and
An integration unit for integrating an amount of displacement detected by the laser type sensor in a predetermined range in the lid unit to obtain an integrated value;
A first determination unit for determining the quality of the internal pressure of the sealed container based on the integrated value obtained by the integration unit;
A waveform calculation unit for obtaining a vibration waveform corresponding to the vibration of the lid by the amount of displacement detected by the laser type sensor in another predetermined range in the lid;
A second determination unit that determines the quality of the internal pressure of the sealed container based on the vibration waveform obtained by the waveform calculation unit;
An internal pressure of the sealed container, comprising: a comprehensive determination unit that determines whether the sealed container is non-defective or defective based on a determination result by the first determination unit and a determination result by the second determination unit Inspection device. The internal pressure inspection device for a sealed container according to claim 1,
The striking part and the laser type sensor are arranged facing the lid part of the sealed container that is continuously conveyed in a predetermined direction with a predetermined interval therebetween,
The integrating unit calculates the integrated value by integrating the displacement detected when the sealed container is moving relative to the laser sensor,
The waveform calculation unit is configured to obtain a vibration waveform corresponding to the vibration based on the amount of displacement detected when the sealed container moves relative to the laser sensor. An internal pressure inspection device for a sealed container. The internal pressure inspection device for a sealed container according to claim 1 or 2,
The striking portion has an annular electromagnetic coil disposed on the same axis as the central axis of the sealed container and facing the lid portion;
The laser sensor is configured to irradiate the lid with the laser beam through the inside of the electromagnetic coil, and to receive reflected light reflected by the lid. Internal pressure inspection device for sealed containers. In the internal pressure inspection device for a sealed container according to claim 3, which refers to claim 2 or claim 2,
The laser sensor is configured such that a spot shape, which is a shape of the laser light on the surface of the lid portion of the laser light irradiated on the lid portion, is a shape that is long in a direction intersecting a transport direction of the sealed container. An internal pressure inspection device for a sealed container, characterized in that The internal pressure inspection device for a sealed container according to claim 4,
The internal pressure inspection device for a sealed container, wherein the shape long in the direction intersecting the transport direction of the sealed container is a shape in which a plurality of circular shapes are closely arranged in a direction intersecting the transport direction of the sealed container.

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