JP4476690B2 - Bonding state inspection apparatus and method - Google Patents

Description

  The present invention relates to an adhesion state inspection apparatus and method for inspecting the adhesion state of two solids.

  There are various methods for inspecting the adhesion state between solids. For example, as in a normal ultrasonic flaw detection test, there is a method of determining that the bonding state is poor when the ultrasonic wave is reflected at a portion where the ultrasonic wave is incident and bonded into the solid. This method is considered to be the simplest method.

  However, in a normal ultrasonic flaw detection test, it is necessary to bring an ultrasonic probe into direct contact with a solid surface or to make an ultrasonic wave enter a solid through a contact medium such as water. That is, in order to inspect the adhesion state of two solids, it is necessary to inject ultrasonic waves into either one of the solids. .

  Even in such a case, there is a conventional technique in which an adhesion state is inspected by vibrating a solid using electromagnetic induction. As this kind of conventional adhesion state inspection method, for example, a method of inspecting canned tab dropout has already been disclosed (for example, see Patent Document 1). In this method, the can is forcibly excited by electromagnetic induction, and the tab dropout is determined from the vibration sound generated at that time.

  However, the above-described method can be applied to a product that can forcibly vibrate the entire product, but cannot be applied when the product cannot be vigorously vibrated. Further, when the product is large and the abnormal part is small, the difference between the vibration sound of the normal product and the abnormal product becomes small, and as a result, it is considered difficult to detect the abnormality.

JP-A-63-158427 (page 3-4)

  The present invention has been made in view of the problems associated with the above-described conventional example. Even when ultrasonic waves cannot be incident on two solids to be inspected for adhesion, the product is large and has an abnormal portion. It is an object of the present invention to provide an adhesion state inspection apparatus and method capable of inspecting the adhesion state even when it is small.

  In the adhesion state inspection apparatus and method according to the present invention, when inspecting the adhesion state between a magnet and a base material, a coil is provided near the magnet, and a magnetic field is generated by applying an AC signal to the coil. The magnet is vibrated by an electromagnetic induction effect between the current generated by the magnetic field and the magnetic field of the magnet, and a variation associated with the vibration of the magnet is detected. Based on the detection signal, the adhesion state of the magnet and the base material It is characterized by inspecting.

  According to this invention, even if it is in a state where ultrasonic waves cannot be incident on two solids to be inspected for adhesion, or even if the product is large and the abnormal portion is small, the adhesion can be inspected. .

Embodiment 1 FIG.
FIG. 1 is a block diagram showing a configuration of an apparatus for realizing an adhesion state inspection method according to Embodiment 1 of the present invention. As shown in FIG. 1, a coil 3 is provided at a position close to a magnet 1 bonded to a base material 2, and an AC transmission signal is supplied to the coil 3 from a transceiver 5 including AC signal supply means. The The base material 2 is irradiated with a laser beam from a laser displacement meter 4. Here, a magnetic field is generated in the coil 3 on the basis of the application of the AC signal to the coil 3, and fluctuations caused by the vibration of the magnet 1 generated by the electromagnetic induction effect between the current generated by the magnetic field and the magnetic field by the magnet 1. The signal is detected by a laser displacement meter 4 as detection means for detecting vibration of the base material 2 as a signal. Then, the detection signal is sent to the transmitter / receiver 5 including the inspection means, and the transmitter / receiver 5 inspects the adhesion state between the magnet 1 and the base material 2 based on the detection signal. Note that the portion to be inspected is between the magnet 1 and the base material 2 and the adhesion state between the magnet 1 and the base material 2 is inspected. In addition, the inspection of the adhesion state in the present invention includes not only peeling but also a general bonding failure inspection.

  In FIG. 1, the coil 3 is installed near the magnet 1, and there is nothing in between, and is in a completely non-contact state. There is nothing between the laser displacement meter 4 and the base material 2, and it is in a completely non-contact state. A laser beam is irradiated from the laser displacement meter 4 to the base material 2, and the laser beam is indicated by an arrow in FIG. 2 and 3 show waveforms of an AC transmission signal sent from the transmitter / receiver 5 to the coil 3.

  Next, the operation of the adhesion state inspection apparatus having the configuration shown in FIG. 1 will be described. An AC transmission signal shown in FIG. 2 is sent to the coil 3 from the transceiver 5. The transmission signal is a burst signal as shown in FIG. 2, and the period T is set to the reciprocal of the frequency f at which the magnet 1 and the base material 2 vibrate efficiently. That is, the carrier frequency of the transmission signal is f. Thereby, a magnetic field is generated in the coil 3 based on the transmission signal. Due to the generated magnetic field, an electric current is generated in the vicinity of the boundary surface between the magnet 1 and the base material 2, and as a result, the magnet 1 vibrates due to electromagnetic induction. If the magnet 1 and the base material 2 are completely bonded, the base material 2 also vibrates as the magnet 1 vibrates.

  The vibration of the base material 2 generated by the vibration of the magnet 1 propagates through the base material 2 and reaches the place where the laser beam of the laser displacement meter 4 is irradiated. The laser displacement meter 4 detects the vibration, and the detected signal is sent to the transceiver 5. The transmitter / receiver 5 includes a signal processing unit as an inspection unit for inspecting the adhesion state between the magnet 1 and the base material 2 based on a detected signal (not shown). In this signal processing unit, a laser displacement meter is included. The signal sent from 4 is processed.

  On the other hand, when an adhesion failure such as peeling between the magnet 1 and the base material 2 occurs, the propagation of vibration is different. The same is true until the magnet 1 vibrates due to the electromagnetic induction action. However, since the adhesion state between the magnet 1 and the base material 2 is poor, the state of vibration transmission to the base material 2 is different. That is, the amplitude of the vibration to be transmitted changes as compared with the bonded state. Depending on the inspection object, the vibration phase may also change. As a result, the vibration propagating through the base material 2 is different from the bonded state.

  A signal processing unit in the transmitter / receiver 5 processes a signal from the laser displacement meter 4 and determines an adhesion state between the magnet 1 and the base material 2. As a signal processing method, for example, when the signal amplitude exceeds a certain value, a large vibration is transmitted from the magnet 1 to the base material 2, so it is determined that the adhesion state is good, and the signal amplitude is less than a certain value. In this case, since only a small vibration is transmitted from the magnet 1 to the base material 2, there is a method for determining that the bonding state is defective.

  Various signal processing methods other than the above simple method can be considered. For example, when the phase of vibration with good adhesion and the phase of vibration with poor adhesion are different, there is a method using the phase difference between these vibrations. The type of signal processing method to be applied is determined by appropriately considering the actual characteristics of the inspection object.

  Further, since the burst wave of the transmission signal shown in FIG. 2 includes frequency components other than the carrier frequency f in the first part and the last part of the signal, the vibration is complicated. In order to remove this extra frequency component, as shown in FIG. 3, amplitude modulation is applied to the first part and the last part of the signal to reduce the extra frequency component, and this signal is used as a transmission signal. Processing in the signal processing of the device 5 is simplified.

  Since the adhesion state inspection method shown in Embodiment 1 of the present invention uses electromagnetic induction, it can be applied even when ultrasonic waves cannot be incident on the magnet 1 and the base material 2. Further, since only the portion where the adhesion state is to be inspected is vibrated, the present invention can be applied even when the base material 2 is large and the magnet 1 is small, that is, when the product is large and the abnormal portion is small.

  As described above, according to the first embodiment, a magnetic field is generated by flowing an AC transmission signal through the coil 3 installed near the magnet 1, and the magnet 1 is generated by the current generated by the magnetic field and the electromagnetic induction effect of the magnet 1. By detecting the vibration transmitted from the magnet 1 to the base material 2 with the laser displacement meter 4, even if the ultrasonic wave cannot be incident on the magnet 1 and the base material 2, Even if it is large and the abnormal part is small, there is an effect that the adhesion state can be inspected.

Embodiment 2. FIG.
FIG. 4 is a block diagram showing the configuration of an apparatus for realizing the adhesion state inspection method according to Embodiment 2 of the present invention. The contact state inspection apparatus according to the second embodiment shown in FIG. 4 is substantially the same as the first embodiment shown in FIG. 1, but the variation of the base material 2 as a fluctuation signal associated with the vibration of the magnet 1 in the first embodiment. Instead of the laser displacement meter 4 that detects vibration, an acceleration sensor 6 is used. The laser displacement meter 4 can detect vibrations in a completely non-contact state, but since the setting is complicated, it may be difficult to inspect at the actual site. In the second embodiment, the vibration of the base material 2 is detected as a variation signal associated with the vibration of the magnet 1 using the acceleration sensor 6 that is easy to set even in an actual site.

  The operation of the second embodiment is almost the same as that of the first embodiment except that the method for detecting vibration is different. That is, the AC transmitter signal shown in FIG. 2 is sent from the transceiver 5 to the coil 3. The coil 3 generates a magnetic field based on the transmission signal. Due to the generated magnetic field, a current is generated in the vicinity of the boundary surface between the magnet 1 and the base material 2, and as a result, the magnet 1 vibrates due to electromagnetic induction. When the adhesion is good, the vibration of the magnet 1 is transmitted to the base material 2 as it is, and when the adhesion is poor, the amplitude of the transmitted vibration changes. Depending on the inspection object, the phase of vibration also changes. The vibration detected by the acceleration sensor 6 is sent to the transmitter / receiver 5 and processed by a signal processing unit in the transmitter / receiver 5.

  The signal processing method is the same as in the first embodiment, for example, when the amplitude of the signal exceeds a certain value, a large vibration is transmitted from the magnet 1 to the base material 2, so it is determined that the adhesion state is good, and the signal Is less than a certain value, only a small vibration is transmitted from the magnet 1 to the base material 2, so that there is a method for determining that the adhesion state is defective. In addition, there is a method using the phase difference of vibrations when the phases of vibrations in a state of good adhesion and in a state of poor adhesion are different. The type of signal processing method to be applied is determined by appropriately considering the actual characteristics of the inspection object.

  Similarly to the first embodiment, the burst wave of the transmission signal shown in FIG. 2 includes frequency components other than the carrier frequency f in the first part and the last part of the signal, thus complicating vibration. In order to remove this extra frequency component, as shown in FIG. 3, the first and last portions of the signal are subjected to amplitude modulation to reduce the extra frequency component, and this signal is used as a transmission signal. 5 is simplified.

  Since the adhesion state inspection method shown in the second embodiment of the present invention uses electromagnetic induction as in the method shown in the first embodiment, ultrasonic waves can be incident on the magnet 1 and the base material 2. Applicable even if it is not possible. Further, since only the portion where the adhesion state is to be inspected is vibrated in the same manner as the method described in the first embodiment, the base material 2 is large and the magnet 1 is small, that is, the product is large and the abnormal portion is small. Is also applicable.

  As described above, according to the second embodiment, a magnetic field is generated by flowing an AC transmission signal through the coil 3 installed near the magnet 1, and the magnet 1 is generated by the current generated by the magnetic field and the electromagnetic induction effect of the magnet 1. By detecting the vibration transmitted from the magnet 1 to the base material 2 with the acceleration sensor 6, even if the ultrasonic wave cannot enter the magnet 1 and the base material 2, the product is large. Even if the abnormal portion is small, the adhesive state can be inspected.

Embodiment 3 FIG.
FIG. 5 is a block diagram showing a configuration of an apparatus for realizing an adhesion state inspection method according to Embodiment 3 of the present invention. The adhesion state inspection apparatus according to the third embodiment shown in FIG. 5 is substantially the same as the first and second embodiments shown in FIGS. 1 and 4, but as a dedicated apparatus for detecting vibration in the first and second embodiments. The laser displacement meter 4 and the acceleration sensor 6 are not provided, and a current detection means is provided in the transmitter / receiver 5, and a change in the current flowing in the coil 3 due to the vibration of the magnet is obtained as a fluctuation signal accompanying the vibration of the magnet 1. By detecting, the adhesion state of the magnet 1 and the base material 2 is inspected.

  Next, the operation of the third embodiment will be described. The process is the same as in the first and second embodiments until the magnetic field is generated by the coil 3 and the magnet 1 is vibrated by the electromagnetic induction action as shown in FIG.

  When the magnet 1 vibrates, the magnetic field changes due to the vibration, and as a result, the alternating current flowing through the coil 3 changes. Since the vibration state of the magnet 1 is different between the case where the adhesion state between the magnet 1 and the base material 2 is good and the case where it is bad, the alternating current flowing through the coil 3 is also poor when the adhesion state is good. Differences occur in some cases. The AC current difference includes not only the signal amplitude difference but also the phase difference.

  In the third embodiment, the transmitter / receiver 5 includes current detection means that not only transmits an alternating current to the coil 3 but also detects a change in current flowing into the coil. The signal processing method in the signal processing unit of the transmitter / receiver 5 measures and stores in advance the current flowing into the coil 3 when the adhesion state is good, and compares it with the alternating current obtained in the actual inspection, If there is no significant difference, it is determined that the bonding state is good, and if there is a significant difference, it is determined that the bonding state is poor.

  Similarly to the first and second embodiments, the burst wave of the transmission signal shown in FIG. 2 includes frequency components other than the carrier frequency f in the first part and the last part of the signal. Make it complicated. In order to remove this extra frequency component, as shown in FIG. 3, the first and last portions of the signal are subjected to amplitude modulation to reduce the extra frequency component, and this signal is used as a transmission signal. 5 is simplified.

  Since the adhesion state inspection method shown in the third embodiment of the present invention uses the electromagnetic induction action similarly to the method shown in the first and second embodiments, ultrasonic waves are incident on the magnet 1 and the base material 2. Applicable even when it is not possible. In addition, since only the portion to be inspected for adhesion is vibrated in the same manner as in the first and second embodiments, the base material 2 is large and the magnet 1 is small, that is, the product is large and the abnormal portion is small. It can be applied even if it exists.

  As described above, according to the third embodiment, a magnetic field is generated by flowing an AC transmission signal through the coil 3 installed near the magnet 1, and the magnet 1 is caused by the current generated by the magnetic field and the electromagnetic induction effect of the magnet 1. By measuring the change of the current flowing into the coil 3 even when the ultrasonic wave cannot be incident on the magnet 1 and the base material 2, the product is large and the abnormal part is small. Even if it exists, there exists an effect that an adhesion state can be test | inspected.

Embodiment 4 FIG.
FIG. 6 is a block diagram showing a configuration of an apparatus for realizing an adhesion state inspection method according to Embodiment 4 of the present invention. In the first to third embodiments, the magnet 1 and the coil 3 are not specified for which components, but the fourth embodiment shows the case where the magnet 1 and the coil 3 are motor components. It is a thing.

  FIGS. 6A and 6B show a cross-sectional view and a side view of the motor, respectively. In the fourth embodiment, the base material 2 in the first to third embodiments corresponds to the rotor 7 of the motor shown in FIG. 6, and the magnet 1 in the first to third embodiments is the rotor 7 of the motor shown in FIG. 6 corresponds to the coil 3 used for rotating the rotor 7 shown in FIG. 6. In FIG. 6, 5 is a transceiver, 6 is an acceleration sensor, 8 is a motor stator, and 9 is a motor shaft. The magnet 1 is bonded to the rotor 7, and the adhesion state between the magnet 1 and the rotor 7 is inspected. The coil 3 is incorporated in the stator 8. Although FIG. 6A shows one coil, there are actually a plurality of coils. Only one coil is shown for ease of drawing and description.

  As the operation of the motor, since the current is passed through the coil 3 to move the magnet 1 and the rotor 7 is rotated, the coil 3 used in the adhesion state inspection is the same as the coil that drives the motor. The actual motor is configured such that the rotor 7 is covered with the stator 8, and it is practically impossible to newly install a coil dedicated for inspection near the magnet 1. In the fourth embodiment, the motor driving coil 3 incorporated in the stator 8 is also used for inspection. With this configuration, it is not necessary to install a new inspection coil, and the device configuration is simplified.

  Next, the operation of the fourth embodiment will be described. When used as a motor, the coil 3 is connected to a motor drive circuit, but when performing inspection, the connection is changed and the coil 3 is connected to the transmitter / receiver 5 for inspection. The transmitter / receiver 5 sends the AC transmission signal shown in FIG. 2 to the coil 3, and the magnet 1 vibrates due to the electromagnetic induction action. As in the first to third embodiments, the magnet 1 and the rotor 7 When the adhesion is good, the vibration is transmitted to the rotor 7 as it is. The vibration of the rotor 7 propagates to the stator 8 via the motor shaft 9. Vibration is detected by installing the acceleration sensor 6 on the stator 8.

  The signal processing unit of the transmitter / receiver 5 determines the adhesion state by processing the vibration detected by the acceleration sensor 6. In the signal processing method, as in the second embodiment, for example, when the amplitude of the signal exceeds a certain value, a large vibration is transmitted from the magnet 1 to the rotor 7, so that the adhesion state is good. When the signal amplitude is equal to or smaller than a certain value, only a small vibration is transmitted from the magnet 1 to the rotor 7, and therefore there is a method for determining that the adhesion state is defective. In addition, there is a method using the phase difference of vibrations when the phases of vibrations in a state of good adhesion and in a state of poor adhesion are different. The type of signal processing method to be applied is determined by appropriately examining the actual motor characteristics.

  Similarly to the first to third embodiments, the burst wave of the transmission signal shown in FIG. 2 includes frequency components other than the carrier frequency f in the first part and the last part of the signal, so that the vibration is complicated. . In order to remove this extra frequency component, as shown in FIG. 3, the first and last portions of the signal are subjected to amplitude modulation to reduce the extra frequency component, and this signal is used as a transmission signal. 5 is simplified.

  FIG. 6 shows a device configuration in which the acceleration sensor 6 is brought into contact with the stator 8 to detect vibration, but even if vibration is detected using the laser displacement meter 4 as in the first embodiment. I do not care. Similarly to the third embodiment, the adhesion state may be determined by measuring a change in current flowing into the coil 3.

  Since the adhesion state inspection method shown in the fourth embodiment of the present invention uses an electromagnetic induction action as in the methods shown in the first to third embodiments, ultrasonic waves are incident on the magnet 1 and the rotor 7. Applicable even if it is not possible. Moreover, since only the part which wants to test | inspect an adhesion state is vibrated similarly to the method shown in Embodiment 1-3, when the rotor 7 is large and the magnet 1 is small, that is, when the product is large and the abnormal part is small. It can be applied even if it exists.

  As described above, according to the fourth embodiment, a magnetic field is generated by causing an AC transmission signal to flow through the same coil 3 as the coil used for driving the motor. When the rotor 7 is vibrated and the vibration propagated to the stator 8 via the motor shaft 9 is detected by the acceleration sensor 6, ultrasonic waves cannot enter the magnet 1 and the rotor 7. In addition, even when the product is large and the abnormal portion is small, the adhesion state can be inspected.

It is a block diagram which shows the structure of the apparatus which implement | achieves the adhesion state inspection method which concerns on Embodiment 1 of this invention. It is a figure which shows the waveform of the alternating current transmission signal sent to the coil 3 from the transmitter / receiver 5 of FIG. It is a figure which shows the waveform which carried out amplitude modulation to the first part and the last part of the signal waveform shown in FIG. 2, and reduced the excess frequency component. It is a block diagram which shows the structure of the apparatus which implement | achieves the adhesion state inspection method which concerns on Embodiment 2 of this invention. It is a block diagram which shows the structure of the apparatus which implement | achieves the adhesion state test | inspection method concerning Embodiment 3 of this invention. It is a block diagram which shows the structure of the apparatus which implement | achieves the adhesion state test | inspection method concerning Embodiment 4 of this invention.

Explanation of symbols

  1 magnet, 2 base material, 3 coil, 4 laser displacement meter, 5 transmitter / receiver, 6 acceleration sensor, 7 rotor, 8 motor stator, 9 motor shaft.

Claims (7)

In the adhesion state inspection device that inspects the adhesion state between the magnet and the base material,
A coil provided at a position close to the magnet;
AC signal supply means for supplying an AC signal to the coil;
Detection for detecting a fluctuation signal associated with vibration of the magnet generated by electromagnetic induction action of a current generated by the magnetic field generated in the coil based on application of an AC signal to the coil by the AC signal applying means and a magnetic field generated by the magnet Means,
An adhesion state inspection apparatus comprising: inspection means for inspecting an adhesion state between the magnet and the base material based on a signal detected by the detection means. The adhesion state inspection apparatus according to claim 1, wherein the AC signal supply unit supplies an AC signal subjected to amplitude modulation. In the adhesion state inspection device according to claim 1 or 2,
The base material is a rotor of a motor;
The magnet is bonded to the rotor,
The said coil is a coil used in order to rotate the said rotor. The adhesion state inspection apparatus characterized by the above-mentioned. In the adhesion state inspection device according to any one of claims 1 to 3,
The said detection means is a laser displacement meter which detects the vibration of the said base material as a fluctuation signal accompanying the vibration of the said magnet. The adhesion state inspection apparatus characterized by the above-mentioned. In the adhesion state inspection device according to any one of claims 1 to 3,
The said detection means is an acceleration sensor which detects the vibration of the said base material as a fluctuation signal accompanying the vibration of the said magnet. The adhesion state inspection apparatus characterized by the above-mentioned. In the adhesion state inspection device according to any one of claims 1 to 3,
The said detection means is an electric current detection means which detects the change of the electric current which flows into the said coil with the vibration of the said magnet as a fluctuation signal accompanying the vibration of the said magnet. The adhesion state inspection apparatus characterized by the above-mentioned. In the adhesion state inspection method for inspecting the adhesion state between the magnet and the base material,
A coil is provided at a position close to the magnet,
A magnetic field is generated by applying an AC signal to the coil,
The magnet is vibrated by the electromagnetic induction effect of the current generated by the magnetic field and the magnetic field by the magnet,
Detecting fluctuations associated with the vibration of the magnet;
An adhesion state inspection method, wherein the adhesion state between the magnet and the base material is inspected based on the detection signal.

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