JP2016180701A - Foreign substance mixing inspection device and method for inspecting the mixing - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable rapid and accurate detection of a non-magnetic material mixed in a magnetic material.SOLUTION: The present invention includes: a magnetic eraser 30 demagnetizing an inspection object 10; a magnetic impedance sensor 40 generating an eddy current in a metal mixed in the demagnetized inspection target 10 and detecting magnetic impedance based on a magnetic field caused by the eddy current; and detecting means detecting metal foreign substance mixed in the inspection object based on an output from the magnetic impedance sensor 40.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a foreign matter contamination inspection apparatus and method, and more particularly, to a foreign matter contamination inspection device and method suitable for application when a nonmagnetic material is mixed in an inspection target of a magnetic material.

  Conventionally, non-magnetic foreign matter detection using X-rays is described in Patent Document 1. However, when X-rays are used, there is a problem that processing is performed at a slow speed. Patent Document 2 discloses that nonmagnetic foreign matter detection is performed using a solid-state imaging device. However, this detects foreign matter from the transparent body, and there is a problem that it cannot be detected unless there is a relationship with a specific color.

  Further, Patent Document 3 discloses a magnetic sensor device that detects magnetic metal and non-magnetic metal. Further, Patent Document 4 discloses a technique for detecting foreign matter after demagnetization.

  However, the devices described in Patent Documents 3 and 4 have a problem that the devices are complicated and expensive.

JP 2005-342651 A Japanese Patent Laid-Open No. 7-116611 JP 2014-10118 A JP 2012-138318 A

  The present invention has been made in view of the present situation of the foreign matter contamination inspection apparatus as described above, and the object thereof is to appropriately detect at high speed when a non-magnetic material is mixed in a magnetic material, and to simplify the configuration. It is an object to provide a foreign substance contamination inspection apparatus and method that are inexpensive and inexpensive.

  A foreign matter contamination inspection apparatus according to the present invention includes a demagnetizer for degaussing an inspection object, and a magnetic impedance for detecting magnetic impedance based on a magnetic field caused by the eddy current by causing an eddy current in a metal mixed in the inspection object after demagnetization. The sensor comprises: a sensor; and a detecting means for detecting a metal foreign object mixed in the inspection object based on the output of the magnetic impedance sensor.

  In the foreign matter contamination inspection apparatus according to the present invention, the magnetic impedance sensor has an eddy current generator, and an eddy current is generated by applying an alternating current to the eddy current generator.

  In the foreign matter contamination inspection apparatus according to the present invention, the inspection object is a magnetic material, and the metal foreign material is a nonmagnetic material.

  In the foreign matter contamination inspection apparatus according to the present invention, the inspection object has a predetermined width, and scans in a direction orthogonal to the width direction of the predetermined width using one or a plurality of magnetic impedance sensors.

  In the foreign matter contamination inspection apparatus according to the present invention, the inspection object has a predetermined width, and a plurality of magnetic impedance sensors are used, and the sensors adjacent to each other at a distance where the two sensors do not interfere with each other are separated and detected. It is characterized by.

  In the foreign matter contamination inspection apparatus according to the present invention, scanning is performed in a direction orthogonal to the width direction of the predetermined width, the plurality of sensors are arranged linearly in the width direction, and arranged alternately in the scan direction, It arranges and performs detection.

  In the foreign matter contamination inspection apparatus according to the present invention, scanning is performed in a direction orthogonal to the width direction of the predetermined width, and adjacent sensors are arranged in a straight line by shifting by a predetermined dimension in the scanning direction, and are detected by being arranged. And

  The foreign matter contamination inspection method according to the present invention includes a degaussing step for degaussing the inspection object, and an eddy current generated in the metal mixed in the inspection object after demagnetization, and the magnetic impedance is measured by the magnetic impedance sensor based on the magnetic field due to the eddy current. It comprises a magnetic impedance detection step for detecting, and a foreign matter detection step for detecting a metallic foreign matter mixed in the inspection object based on the output of the magnetic impedance sensor.

  The foreign matter contamination inspection method according to the present invention is characterized in that, in the magnetic impedance detection step, detection is performed by applying an alternating current to an eddy current generator of the magnetic impedance sensor to generate an eddy current.

  In the foreign matter contamination inspection method according to the present invention, the inspection object is a magnetic material, and the metal foreign material is a non-magnetic material.

  In the foreign matter contamination inspection method according to the present invention, the inspection object has a predetermined width, and the inspection is performed by scanning in a direction orthogonal to the width direction of the predetermined width using one or a plurality of magnetic impedance sensors. It is characterized by.

  In the foreign matter contamination inspection method according to the present invention, the inspection object has a predetermined width, and a plurality of magnetic impedance sensors are used, and the adjacent sensors are arranged apart from each other so that the two sensors do not interfere with each other. It is characterized by.

  In the foreign matter contamination inspection method according to the present invention, scanning is performed in a direction perpendicular to the width direction of the predetermined width, the plurality of sensors are arranged linearly in the width direction, and arranged alternately in a zigzag in the scan direction, It arranges and performs detection.

  In the foreign matter contamination inspection method according to the present invention, scanning is performed in a direction orthogonal to the width direction of the predetermined width, and adjacent sensors are arranged in a straight line with a predetermined dimension shifted in the scanning direction, and are detected by being arranged. And

  According to the present invention, the test object is demagnetized, eddy current is generated in the metal mixed in the test object after demagnetization, and the magnetic impedance is detected using the magnetic impedance sensor based on the magnetic field due to the eddy current, and the output Therefore, the foreign object can be detected appropriately at high speed, and the configuration is simple and inexpensive.

The block diagram which shows the structure of the foreign material mixing inspection apparatus which concerns on embodiment of this invention. The principal part top view which shows the structure of the foreign material mixing inspection apparatus which concerns on embodiment of this invention. The top view of 1st Embodiment which shows the principal part which provided and comprised two or more the magnetic impedance sensors of the foreign material mixing inspection apparatus of this invention. The top view of 2nd Embodiment which shows the principal part which provided and comprised the multiple magnetic impedance sensor of the foreign material mixing inspection apparatus of this invention. The figure which shows the measurement result by the foreign material mixing inspection apparatus which concerns on embodiment of this invention. The figure which shows the measurement result by the foreign material mixing inspection apparatus which concerns on embodiment of this invention.

  Embodiments of a foreign matter contamination inspection apparatus and foreign matter contamination inspection method according to the present invention will be described below with reference to the accompanying drawings. FIG. 1 shows a configuration diagram of a foreign matter contamination inspection apparatus according to an embodiment. The foreign matter mixing inspection apparatus conveys the inspection object 10 by a conveyance apparatus 20 such as a belt conveyor having a conveyance path made of an insulating material such as cloth. A demagnetizer 30 is provided on the conveyance path, and demagnetizes the inspection object 10 being conveyed. As the demagnetizer 30, a publicly known one can be used.

  A magnetic impedance sensor 40 is provided at the point where the demagnetized inspection object 10 is conveyed. That is, the demagnetizer 30 and the magnetic impedance sensor 40 are arranged as shown in the plan view of the conveyance path in FIG. An arrow X indicates the conveyance direction of the inspection object 10. The magnetic impedance sensor 40 faces the inspection object 10 and is separated from each other.

  The magnetic impedance sensor 40 is provided with an eddy current generator (not shown) that generates a magnetic field in the paper plane direction of FIG. 2 and generates eddy currents in the metal mixed in the inspection object 10 after demagnetization. An eddy current is generated by applying alternating current as an excitation signal to the current generator. The eddy current generating part can be constituted by a coil. The magnetic impedance sensor 40 detects magnetic impedance based on the magnetic field generated by the eddy current. That is, since the eddy current generates a reverse magnetic field, the magnetic field generated by the reverse magnetic field changes the impedance of the magnetic impedance sensor 40. The magnetic impedance sensor 40 outputs a change in voltage due to a change in impedance.

  The output of the magnetic impedance sensor 40 is sent to the amplifier 50. The amplifier 50 amplifies the voltage that is the output of the magnetic impedance sensor 40 and sends it to the computer 60. The computer 60 functions as a detection unit that digitizes and captures the output of the magnetic impedance sensor 40 and detects metal foreign matter mixed in the inspection object 10 based on the digital data.

  The digital data that is the output of the magnetic impedance sensor 40 fluctuates more than usual in the portion of the metallic foreign matter mixed in the inspection object 10. This change is captured and determined as a foreign object. A foreign object can be determined using a predetermined threshold.

  In the above, the inspection object 10 can be a magnetic body, and the metal foreign object can be a non-magnetic body. More specifically, the inspection object 10 is reticulated nickel which is a positive electrode of a nickel metal hydride battery, and the metal foreign matter can be copper. In addition to the positive electrode of the nickel metal hydride battery, the test object 10 may be a negative electrode or separator of a nickel metal hydride battery, and may be a negative electrode or separator other than the positive electrode of the lithium ion battery. The separator is non-metallic, but it can also be detected when a non-magnetic material is mixed in such non-metallic material. Further, the inspection object 10 is solid in the above example, but may be liquid or powder. In the case of a liquid, the object to be inspected can be inspected by pouring the inspection object into a bag or the like. Even when non-magnetic metal foreign matter is contained in the inspection object or when it is not visible, such as when it is mixed with the back side of the inspection object as viewed from the sensor, the present invention reliably ensures that the inspection object 10 is not contacted. Metal foreign objects can be detected.

  As shown in FIG. 2, when the inspection object 10 has a predetermined width W, one magnetic impedance sensor 40 can be used when W is within the detection range of one magnetic impedance sensor 40. When W exceeds the detection range of one magnetic impedance sensor 40, a plurality of magnetic impedance sensors 40 can be used. The magnetic impedance sensor 40 scans in a direction orthogonal to the width direction of the predetermined width W.

  In the present embodiment, the scan is performed by transporting the inspection object 10 by the transport device 20. However, the scan may be performed by moving the demagnetizer 30 or the magnetic impedance sensor 40. When a plurality of magnetic impedance sensors 40 are used, the detection is performed by arranging the adjacent sensors 40 apart from each other so that the two sensors 40 do not interfere with each other.

  In the first embodiment as a specific example, scanning is performed in a direction orthogonal to the width direction of the predetermined width W, and a plurality of sensors 40-1 to 40-8 are arranged in the width direction W as shown in FIG. The detection is performed by arranging them in a straight line and arranging them in a zigzag pattern every other scanning direction. Sensors adjacent to each other in the vertical direction in the figure are displaced by a dimension s in the scanning direction. The plurality of sensors 40-1 to 40-8 can be molded and fixed to an insulating member 70 such as plastic.

  In the second embodiment as a specific example, scanning is performed in a direction perpendicular to the width direction of the predetermined width W, and adjacent sensors are arranged in a straight line by shifting by a predetermined dimension in the scanning direction and are detected. For example, as shown in FIG. 4, the plurality of sensors 40-1 to 40-8 are shifted to the right by the size k as the lower sensor in the figure, and the plurality of sensors 40-1 to 40-8 are slanted. Are arranged in a straight line.

  When a plurality of sensors 40-1 to 40-8 are used, their outputs are sent to different amplifiers 50, and the outputs of the plurality of amplifiers 50 can be given to one computer 60. The computer 60 functions as detection means for digitizing and capturing the outputs of the plurality of magnetic impedance sensors 40-1 to 40-8 and detecting the metal foreign matter mixed in the inspection object 10 based on the respective digital data. Therefore, when there are a plurality of metal foreign objects in the width direction, a reaction appears in a plurality of digital data, so that the foreign object can be detected without omission.

  FIG. 5 shows a graph of the result of detecting Cu, which is a foreign substance, on the inspection object Ni (sponge-like Ni sheet) using one magnetic impedance sensor 40. Table 1 shows the measurement conditions.

  A large output fluctuation is observed at a position of approximately 77 mm from the start of measurement, and is converged at a position of approximately 82 mm. It can be seen that it is possible to accurately detect the non-magnetic foreign matter mixed in the magnetic material.

  FIG. 6 shows the result of inspection using an apparatus having a mechanism for scanning one magnetic impedance sensor 40 in the width direction. The magnetic impedance sensor 40 was used under the conditions shown in Table 1. The line segment J1 in FIG. 6 has the highest sensitivity and is a measurement result when it is considered that nonmagnetic foreign matter is mixed in the position. The line segment J2 is 0.5 mm from the measurement position where the line segment J1 was obtained. It is a measurement result when moving the magnetic impedance sensor 40 to either side of the width direction. A line segment J3 shows a measurement result when the magnetic impedance sensor 40 is moved in the 0.5 mm width direction opposite to the measurement position of the line segment J2 from the measurement position where the line segment J1 is obtained. In this way, the foreign matter inspection can be performed by scanning in the width direction using one magnetic impedance sensor 40.

  As the scanning mechanism in the width direction, a rail extending in the width direction is provided in the conveyance path, a carrier that moves on the rail by, for example, a stepping motor is provided on the rail, and a magnetic impedance sensor 40 is provided on the carrier. The thing provided with the control apparatus which controls a stepping motor is employable.

DESCRIPTION OF SYMBOLS 10 Inspection object 20 Conveyance apparatus 30 Demagnetizer 40, 40-1 to 40-8 Magnetic impedance sensor 50 Amplifier 60 Computer 70 Insulating member

Claims (14)

A degausser that degausses the inspection object;
A magnetic impedance sensor for detecting magnetic impedance based on a magnetic field caused by eddy current by generating eddy current in the metal mixed in the inspection object after demagnetization;
A foreign matter contamination inspection apparatus, comprising: a detecting unit that detects metal foreign matter mixed in the inspection object based on an output of the magnetic impedance sensor.   2. The foreign matter contamination inspection apparatus according to claim 1, wherein the magnetic impedance sensor includes an eddy current generation unit, and generates an eddy current by applying an alternating current to the eddy current generation unit.   The foreign matter contamination inspection apparatus according to claim 1 or 2, wherein the inspection object is a magnetic material, and the metal foreign material is a nonmagnetic material.   The inspection object has a predetermined width, and scans in a direction orthogonal to the width direction of the predetermined width using one or a plurality of magnetic impedance sensors. The foreign matter contamination inspection device described.   The inspection object has a predetermined width, and a plurality of magneto-impedance sensors are used, and detection is performed by arranging the sensors adjacent to each other at a distance where the two sensors do not interfere with each other. The foreign matter contamination inspection apparatus according to any one of the above items.   Scanning in a direction perpendicular to the width direction of the predetermined width, and detecting the plurality of sensors arranged in a straight line in the width direction and arranged in a zigzag manner in every other scan direction. The foreign matter contamination inspection apparatus according to claim 5.   6. Foreign matter contamination according to claim 5, wherein scanning is performed in a direction perpendicular to the width direction of the predetermined width, and adjacent sensors are detected by being arranged in a straight line with a predetermined dimension shifted in the scanning direction. Inspection device. A degaussing step for degaussing the inspection object;
A magnetic impedance detection step of generating an eddy current in the metal mixed in the inspection object after demagnetization and detecting the magnetic impedance by a magnetic impedance sensor based on the magnetic field due to the eddy current;
A foreign matter detection method, comprising: a foreign matter detection step of detecting a metallic foreign matter mixed in the inspection object based on an output of the magnetic impedance sensor.   9. The foreign matter contamination inspection method according to claim 8, wherein, in the magnetic impedance detection step, detection is performed by applying an alternating current to an eddy current generator of the magnetic impedance sensor to generate an eddy current.   10. The foreign matter contamination inspection method according to claim 8, wherein the inspection object is a magnetic material, and the metal foreign material is a non-magnetic material.   11. The inspection object has a predetermined width, and the inspection is performed by scanning in a direction orthogonal to the width direction of the predetermined width using one or a plurality of magneto-impedance sensors. The foreign matter contamination inspection method according to any one of the above items.   The inspection object has a predetermined width, and a plurality of magneto-impedance sensors are used, and detection is performed by arranging sensors adjacent to each other at a distance where the two sensors do not interfere with each other. The foreign matter contamination inspection method according to any one of the above items.   Scanning in a direction perpendicular to the width direction of the predetermined width, and detecting the plurality of sensors arranged in a straight line in the width direction and arranged in a zigzag manner in every other scan direction. The foreign matter contamination inspection method according to claim 12. 13. The foreign matter contamination according to claim 12, wherein scanning is performed in a direction perpendicular to the width direction of the predetermined width, and adjacent sensors are detected by being arranged in a straight line with a predetermined dimension shifted in the scanning direction. Inspection device.

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