JP2012242153A - Secondary battery inspection device and inspection method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily and precisely inspect a secondary battery in a short time.SOLUTION: An energization signal supply circuit 65 and an energization circuit 66 supply a current to a secondary battery (lithium ion secondary battery) BA by applying DC voltage obtained by superposing an AC component of a specific frequency between electrodes of the secondary battery BA. The DC voltage obtained by superposing the AC component is within a range of an operation voltage of the secondary battery BA. A magnetic sensor 10, driven by an X direction slide mechanism 20 and a Y direction slide mechanism 30, scans near the lower face of the secondary battery BA to detect a magnetic field generated by the current running through each part of the secondary battery BA. A detection signal of the magnetic field is supplied to a lock-in amplifier 69 via a sensor signal takeout circuit 68. The lock-in amplifier 69 takes out a signal component of the specific frequency from the detection signal by using a signal equal to the specific frequency from the energization signal supply circuit 65 and outputs it.

Description

  The present invention relates to an inspection device and inspection method for a secondary battery that can be charged and reused many times, and in particular, a current flows through the secondary battery, and a magnetic field generated by the current flowing in the secondary battery is generated at a plurality of locations. The present invention relates to a secondary battery inspection apparatus and inspection method for detecting abnormalities and defects of a secondary battery.

  Conventionally, as a method for inspecting a secondary battery, for example, as shown in Patent Document 1 below, a first voltage (4.2 V) is applied for a long time (two weeks), and then a second voltage ( A method is known in which a secondary battery having a large voltage drop rate is determined as a defective product after being charged for a long time (10 hours) at 3.9 V) and left to stand.

JP 2003-36887 A

  However, the invention described in Patent Document 1 has a problem that it takes a long time until the inspection result is obtained, and the inspection efficiency of the secondary battery is not good. The present invention has been made to solve this problem, and it is an object of the present invention to provide a secondary battery inspection apparatus that can inspect a secondary battery easily and in a short time. In addition, in the description of each constituent element of the present invention below, in order to facilitate understanding of the present invention, reference numerals of corresponding portions of the embodiment are described in parentheses, but each constituent element of the present invention is The present invention should not be construed as being limited to the configurations of the corresponding portions indicated by the reference numerals of the embodiments.

  In order to achieve the above object, the present invention is characterized in that a DC voltage obtained by superimposing an AC component of a predetermined frequency on a DC voltage within the operating voltage range of the secondary battery is applied between the electrodes of the secondary battery. Current-carrying means (65, 66) for passing a current to the secondary battery and a magnetic field generated by the current flowing in the plurality of parts, facing the plurality of parts of the secondary battery, and a signal representing the detected magnetic field There are provided magnetic field detection means (10) for output and frequency component extraction means (69) for extracting a signal component having a frequency equal to a predetermined frequency from a signal representing the detection magnetic field output from the magnetic field detection means. In this case, the calculation means (70, 70) further calculates the distribution of the strength of the magnetic field at positions facing the plurality of portions or the distribution of the current magnitudes in the plurality of portions from the signal component extracted from the frequency component extraction means. S10 to S80, S100 to S116, S124 to S130) may be provided. The operating voltage range of the secondary battery is a voltage range that is not less than the lower limit value of the discharge voltage of the secondary voltage and not more than the upper limit value of the charge voltage of the secondary battery.

  When an abnormality occurs in the electrode of the secondary battery, the electrolyte portion, etc., the inventor of the present application changes the distribution of the current flowing through the electrode and electrolyte of the secondary battery, that is, a plurality of portions of the secondary battery, compared to the normal time. It was discovered that the distribution of the magnetic field in the portion facing the plurality of portions of the secondary battery also changes due to the change in the current distribution. Therefore, according to the feature of the present invention, the energization means causes the current to flow through the secondary battery, and the magnetic field detection means detects the magnetic field generated by the current flowing through the plurality of portions. Abnormalities can be detected easily and in a short time. In particular, in this case, the energizing means applies a direct current voltage, in which an alternating current component of a predetermined frequency is superimposed on a direct current voltage within the operating voltage range of the secondary battery, between the electrodes of the secondary battery to supply current to the secondary battery. Therefore, the secondary battery is repeatedly charged and discharged, and the secondary battery after the inspection is not overcharged or overdischarged. Therefore, the secondary battery is not adversely affected. In addition, since only the signal representing the magnetic field generated in relation to the AC component of the predetermined frequency is extracted by the action of the energizing means and the frequency component extracting means, the structure is relatively simple and not affected by the external magnetic field. Magnetic field can be detected. As a result, it is possible to accurately detect the magnetic field generated by the current flowing through the plurality of parts of the secondary battery without reducing the cost of the inspection device and making the external magnetic field uniform, and consequently An abnormality of the secondary battery can be accurately detected.

  Another feature of the present invention is that the DC voltage on which an AC component is superimposed by the energization means is the output voltage of the secondary battery before inspection. According to this, the voltage applied between the electrodes of the secondary battery by the energizing means changes up and down around the output voltage of the secondary battery before the inspection, and is repeatedly charged and discharged. The output voltage of the battery is the same as the output voltage before inspection. As a result, the state of the secondary battery can be kept almost the same before and during the inspection, and can be kept the same as before the inspection after the inspection, and the secondary battery in the state before the inspection. , And other inspections and operations can be realized while maintaining the same state.

  Another feature of the present invention resides in that the DC voltage applied to the secondary battery by the energizing means changes within the operating voltage range of the secondary battery. According to this, even during the inspection, the maximum value and the minimum value of the voltage applied between the electrodes of the secondary battery are always maintained within the operating voltage range of the secondary battery. There is no adverse effect on the battery, and the secondary battery is well inspected.

  Another feature of the present invention is that the distribution of the magnetic field strength or the current magnitude calculated by the calculation means is compared with reference information prepared in advance, and an abnormality of the secondary battery is detected. Determination means (70, S118 to S122) is provided. According to this, when the type, size, shape, etc. of the secondary battery are the same, and the battery can always be set in the same manner with respect to the magnetic field detection means, the comparison with reference information prepared in advance Abnormality of the secondary battery can be easily detected.

  Another feature of the present invention is that it further includes display means (70, S134) for displaying the distribution of the strength of the magnetic field or the distribution of the magnitude of the current calculated by the calculation means. According to this, it is possible to visually determine the abnormality of the secondary battery.

  Furthermore, in carrying out the present invention, the present invention is not limited to the invention of the secondary battery inspection apparatus, and can also be implemented as an invention of a secondary battery inspection method.

1 is an overall configuration diagram of an inspection apparatus for a secondary battery according to an embodiment of the present invention. It is a schematic perspective view which shows the specific example of the moving mechanism of the stage of FIG. 1, and a magnetic sensor. It is a schematic perspective view of the battery setting table set to the stage. It is a detailed circuit block diagram of the magnetic sensor and sensor signal extraction circuit of FIG. FIG. 2 is a detailed circuit block diagram of the lock-in amplifier of FIG. 1. 3 is a flowchart showing the first half of a data acquisition program executed by the controller of FIG. It is a flowchart which shows the second half part of the said data acquisition program. 3 is a flowchart showing a first half of an evaluation program executed by the controller of FIG. It is a flowchart which shows the second half part of the said evaluation program. It is a wave form diagram of the energization voltage impressed to the electrode of a rechargeable battery. It is a wave form diagram of the electric current which flows into the secondary battery detected. It is explanatory drawing of the scanning aspect with respect to the secondary battery by a magnetic sensor.

  Hereinafter, a secondary battery inspection apparatus according to an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is an overall schematic diagram of the secondary battery inspection apparatus. This secondary battery inspection device has a structure that allows a plurality of secondary batteries (lithium ion secondary batteries BA) according to the present embodiment to be inspected at one time. Various structures can be employed accordingly.

  The secondary battery inspection apparatus includes a sensor support base 11 that supports and fixes the magnetic sensor 10. The sensor support base 11 is moved in the X direction (left and right direction on the paper surface) by the X direction slide mechanism 20 and also in the Y direction. The slide mechanism 30 moves in the Y direction (the direction perpendicular to the paper surface). As shown in detail in FIG. 2, the sensor support 11 is formed of a rectangular flat plate, and supports and fixes the magnetic sensor 10 on the upper surface. The sensor support 11 is supported by a rectangular moving member 21 that forms part of the X-direction slide mechanism 20. The moving member 21 is provided with an adjustment mechanism (not shown) that adjusts the vertical position of the magnetic sensor 10 by displacing the sensor support base 11 up and down. The position is adjusted in the vertical direction.

  On the lower surface of the moving member 21, a convex portion 21a having a predetermined width in the Y direction is provided. The convex portion 21a enters the groove 23a provided on the upper surface of the support member 23 extending in the X direction, and slides in the groove 23a in the X direction. A male screw 24 that extends in the X direction and penetrates the convex portion of the moving member 21 is accommodated in the groove 23 a of the support member 23. A nut (not shown) screwed into the male screw 24 is incorporated in the convex portion 21 a of the moving member 21, and the moving member 21 moves in the X direction by the rotation of the male screw 24. That is, the ball screw mechanism is constituted by the male screw 24 and the nut incorporated in the moving member 21. One end of the male screw 24 is connected to a rotation shaft of an X-direction motor 25 assembled to one end of the support member 23, and the other end of the male screw 24 is rotatably supported by the other end of the support member 23. Thereby, the male screw 24 rotates around the axis by the rotation of the X direction motor 25, and the moving member 21, the sensor support base 11, and the magnetic sensor 10 move in the X direction.

  Convex portions 23 b and 23 c having a predetermined width in the X direction are provided on the lower surface of the support member 23 in the vicinity of both ends in the X direction. These convex portions 23b and 23c enter the grooves 31a and 32a provided on the upper surfaces of the support members 31 and 32 respectively extending in the Y direction, and slide in the grooves 31a and 32a in the Y direction. ing. In the groove 31a of the support member 31, a male screw 33 extending in the Y direction and passing through the convex portion 23b of the support member 23 is accommodated. A nut (not shown) screwed into the male screw 33 is incorporated in the convex portion 23 b of the support member 23, and the support member 23 is moved in the Y direction by the rotation of the male screw 33. That is, the ball screw mechanism is configured by the male screw 33 and the nut incorporated in the support member 23. One end of the male screw 33 is connected to a rotation shaft of a Y-direction motor 34 assembled to one end of the support member 31, and the other end of the male screw 33 is rotatably supported by the other end of the support member 31. Thereby, the male screw 33 rotates around the axis by the rotation of the Y direction motor 34, and the support member 23 moves in the Y direction together with the moving member 21, the sensor support 11 and the magnetic sensor 10.

  Further, the secondary battery inspection apparatus includes a stage 40 on which the lithium ion secondary battery BA is placed. The stage 40 includes a frame 42 disposed above the support members 31 and 32 via connecting portions 41 a, 41 b, 41 c and 41 d extending upward from the respective end portions of the support members 31 and 32. Yes. The frame 42 includes outer frames 42a and 42b positioned above the support members 31 and 32, and outer frames 42c and 42d respectively connecting both ends of the outer frames 42a and 42b. The outer frames 42a, 42b, 42c, and 42d are integrally provided with an inner frame 42e that connects the outer frames 42a, 42b, 42c, and 42d to form a rectangular window. Steps are provided in the windows formed by the outer frames 42a, 42b, 42c, 42d and the inner frame 42e, and the battery setting table 50 is assembled to each of these windows.

  As shown in FIG. 3, the battery setting table 50 is formed in a square shape with its end projecting downward, and has a support plate 51 of a size that can be mounted and assembled on a rectangular window of the stage 40. The support plate 51 is provided with a plurality of rectangular recesses (four recesses in this embodiment) 51a in which the lithium ion secondary battery BA is set. A connector 52 to which the electrodes (positive electrode and negative electrode) of the lithium ion secondary battery BA are connected is provided on the inner side surface of the recess 51a. By placing the secondary battery BA on the recess 51a, the lithium ion secondary battery BA is set on the battery setting table 50. FIG. 3 shows a state in which one lithium ion secondary battery BA is set in the recess 51a at the lower right position. When the battery setting table 50 is assembled to the window of the stage 40 and the lithium ion secondary battery BA is set to the battery setting table 50, the magnetic sensor 10 is positioned below the lithium ion secondary battery BA. ing. Connecting wires (electric wires) are respectively connected to the connectors 52 provided in the respective recesses 51a, and these connecting wires are bundled and connected to a connector (not shown) provided on the upper surface in common for each battery set table 50. Has been. On the upper surface of the support plate 51, handles 53 for carrying the battery setting table 50 are also provided.

  Returning to the description of FIG. 1, an encoder 25 a that detects the rotation of the X-direction motor 25 and outputs a rotation signal representing the rotation is incorporated in the X-direction motor 25. This rotation signal is a pulse train signal that alternately switches between a high level and a low level each time the X-direction motor 25 rotates by a predetermined minute angle, and is phase-shifted by π / 2 to identify the rotation direction. The A phase signal and the B phase signal. The rotation signal is output to the X direction position detection circuit 61 and the X direction feed motor control circuit 62. The X-direction position detection circuit 61 counts up or down the number of pulses of the rotation signal in accordance with the rotation direction of the X-direction motor 25, and the X direction of the sensor support 11 with respect to the stage 40 by the X-direction motor 25 from the count value. The position (that is, the X-direction position of the magnetic sensor 10) is detected, and the detected X-direction position is output to the X-direction feed motor control circuit 62 and a controller 70 described later. The X-direction feed motor control circuit 62 controls driving and stopping of the X-direction motor 25 according to instructions from the controller 70. When driving the X-direction motor 25, the X-direction feed motor control circuit 62 rotates the X-direction motor 25 at a predetermined rotation speed using a rotation signal from the encoder 25a.

  The initial setting of the count value in the X-direction position detection circuit 61 is performed according to an instruction from the controller 70 when the power is turned on. That is, the controller 70 instructs the X-direction feed motor control circuit 62 to move to the X-direction limit position corresponding to the initial position of the sensor support 11 and the X-direction position detection circuit 61 to perform initial setting when the power is turned on. In response to this instruction, the X-direction feed motor control circuit 62 drives the X-direction motor 25 to move the sensor support 11 to the X-direction limit position corresponding to the initial position. The X-direction position detection circuit 61 continues to input a rotation signal from the encoder 25a in the X-direction motor 25 while the sensor support base 11 is moving in the X direction. When the sensor support 11 reaches the X direction limit position corresponding to the initial position and the rotation of the X direction motor 25 stops, the X direction position detection circuit 61 detects the stop of the input of the rotation signal from the encoder 25a, The count value is reset to “0”. At this time, the X-direction position detection circuit 61 outputs a signal for stopping output to the X-direction feed motor control circuit 62, whereby the X-direction feed motor control circuit 62 outputs a drive signal to the X-direction motor 25. To stop. Thereafter, when the X direction motor 25 is driven, the X direction position detection circuit 61 counts up or down the number of pulses of the rotation signal in accordance with the rotation direction of the X direction motor 25, and based on the count value. Then, the X direction position of the sensor support 11 is calculated, and the calculated X direction position is continuously output to the X direction feed motor control circuit 62 and the controller 70.

  In the Y-direction motor 34, an encoder 34a that detects the rotation of the Y-direction motor 34 and outputs a rotation signal indicating the rotation is incorporated in the same manner as the X-direction motor 25. This rotation signal is output to the Y direction position detection circuit 63 and the Y direction feed motor control circuit 64. The Y-direction position detection circuit 63 counts up or counts down the number of pulses of the rotation signal in accordance with the rotation direction of the Y-direction motor 34, and the Y-direction position of the sensor support 11 by the Y-direction motor 34 (ie, the count value) The Y position of the magnetic sensor 10 is detected, and the detected Y direction position is output to the Y direction feed motor control circuit 64 and the controller 70. The Y-direction feed motor control circuit 64 controls the driving and stopping of the Y-direction motor 34 according to instructions from the controller 70 as in the case of the X-direction feed motor control circuit 62. When driving the Y-direction motor 34, the Y-direction feed motor control circuit 64 rotates the Y-direction motor 34 at a predetermined speed using a rotation signal from the encoder 34a.

  The initial setting of the count value in the Y-direction position detection circuit 63 is performed according to an instruction from the controller 70 when the power is turned on. That is, the controller 70 instructs the Y-direction feed motor control circuit 64 to move to the Y-direction limit position corresponding to the initial position of the sensor support base 11 and the Y-direction position detection circuit 63 to perform initial setting when the power is turned on. In response to this instruction, the Y-direction feed motor control circuit 64 drives the Y-direction motor 34 to move the sensor support 11 to the Y-direction limit position corresponding to the initial position. The Y-direction position detection circuit 63 continues to input a rotation signal from the encoder 34a in the Y-direction motor 34 while the sensor support 11 is moving in the Y direction. When the sensor support base 11 reaches the Y-direction limit position corresponding to the initial position and the rotation of the Y-direction motor 34 stops, the Y-direction position detection circuit 63 detects the stop of input of the rotation signal from the encoder 34a, The count value is reset to “0”. At this time, the Y-direction position detection circuit 63 outputs a signal for stopping the output to the Y-direction feed motor control circuit 64, whereby the Y-direction feed motor control circuit 64 outputs a drive signal to the Y-direction motor 34. To stop. Thereafter, when the Y direction motor 34 is driven, the Y direction position detection circuit 63 counts up or down the number of pulses of the rotation signal in accordance with the rotation direction of the Y direction motor 34, and based on the count value. The Y-direction position of the sensor support 11 is calculated and the calculated Y-direction position is continuously output to the Y-direction feed motor control circuit 64 and the controller 70.

  The secondary battery inspection apparatus further includes an energization signal supply circuit 65, an energization circuit 66, an energization selection circuit 67, a sensor signal extraction circuit 68, a lock-in amplifier 69, and a controller 70. The energization signal supply circuit 65 includes a sine wave oscillator and a rectangular wave conversion circuit, and is controlled by the controller 70 to supply a sine wave signal oscillated by the sine wave oscillator to the energization circuit 66 as an energization signal. The energization signal is a signal that changes from positive to negative with reference to “0”, and the frequency is, for example, about several tens of hertz to several hundreds of hertz. The energization signal supply circuit 65 generates a rectangular wave signal that changes positively and negatively around “0” in synchronization with the energization signal by converting the energization signal composed of the sine wave signal by the rectangular wave conversion circuit. The reference signal is output to the lock-in amplifier 69.

  The energization circuit 66 is also controlled by the controller 70 and energizes the lithium ion secondary battery BA via the energization selection circuit 67. In this case, the energization circuit 66 adds a positive offset voltage to a sine wave signal that changes positively or negatively with respect to “0” supplied from the energization signal supply circuit 65, and changes in a sine wave shape with the offset voltage as the center. Then, it is converted into an energization signal that always changes within a positive range and supplied to the anode of the lithium ion secondary battery BA. On the other hand, the ground-side terminal of the energization circuit 66 is connected to the cathode of the lithium ion secondary battery BA. That is, a direct current voltage on which an alternating current component having a predetermined frequency is superimposed is applied between the anode and the cathode of the lithium ion secondary battery BA. Note that the DC voltage (energization voltage) on which the AC component is superimposed varies within the operating voltage range of the lithium ion secondary battery BA. That is, the maximum voltage of the energization voltage is not more than the upper limit value of the charging voltage of the lithium ion secondary battery BA, and the minimum voltage is not less than the lower limit value of the discharge voltage of the lithium ion secondary battery BA.

  Specifically, for example, when the upper limit of the charging voltage of the lithium ion secondary battery BA is 4.1 v and the lower limit of the discharge voltage is 2.9 v, a voltage in the vicinity of these (for example, 3.5 v) An AC signal is superimposed on (see FIG. 8). In particular, even if the AC signal is not superimposed on the voltage in the vicinity of the intermediate point, the energized voltage on which the AC signal is superimposed is always between the upper limit of the charging voltage and the lower limit of the discharging voltage of the lithium ion secondary battery BA. For example, an appropriate voltage can be used. Further, the amplitude of the superimposed AC signal is also set so that the energization voltage as a result of the superposition is always between the upper limit of the charging voltage of the lithium ion secondary battery BA and the lower limit of the discharging voltage.

  In this case, when a voltage higher than the current output voltage is applied to the lithium ion secondary battery BA, the current flows in the direction of the current by the energized voltage, that is, the lithium ion secondary battery BA is charged. Further, when a voltage lower than the current output voltage is applied to the lithium ion secondary battery BA, a current flows in a direction opposite to the direction of the current due to the energized voltage, that is, the lithium ion secondary battery BA is discharged. For this reason, the lithium ion secondary battery BA repeats charging and discharging by the application of the energization voltage. FIG. 9 shows the current intensity change at this time in the direction of the current during charging. When a magnetic field component having the same frequency as the energized voltage is detected by the lock-in amplifier 69 and converted into a current component, the value indicated by the arrow is detected as a positive value. This is as if the current flowing in the charging direction was detected by the energization voltage. As a result, as will be described in detail later, by comparing the current distribution obtained by obtaining the detected values at a plurality of positions with that of the reference lithium ion secondary battery BA, Defects can be detected.

  The energization selection circuit 67 supplies the energization voltage supplied from the energization circuit 66 to the lithium ion secondary battery BA via the connection line L1. That is, the plurality of connection lines L1 are respectively connected to connectors provided on the upper surface of each battery set table 50. In this case, the energization selection circuit 67 is controlled by the controller 70 and energizes one lithium ion secondary battery BA designated by the controller 70 among the plurality of set lithium ion secondary batteries BA.

  Next, the magnetic sensor 10 will be described. As shown in FIG. 4, the magnetic sensor 10 includes an X-direction magnetic sensor 10A that detects a magnetic field in the X direction and a Y-direction magnetic sensor 10B that detects a change in the magnetic field in the Y direction. The X-direction magnetic sensor 10A is constituted by a bridge circuit composed of resistors r11, r12, r13 and a magnetoresistive element MR1, and between the connection point of the resistors r11, r13 and the connection point of the resistor r12 and the magnetoresistive element MR1. In addition, voltages + V and −V are applied from a constant voltage supply circuit 68a (described later) of the sensor signal extraction circuit 68. In the X-direction magnetic sensor 10A, a voltage between the connection point of the resistor r13 and the magnetoresistive element MR1 and the connection point between the resistors r11 and r12 is output as an X-direction magnetic detection signal. The values of the resistors r11, r12, r13 are the same and are equal to the resistance value of the magnetoresistive element MR1 when the magnetic field strength is “0”. As a result, the X direction magnetic field detection signal is a voltage that changes positively or negatively in proportion to the magnitude of the magnetic field in the X direction with reference to approximately “0” due to the positive or negative change in the X direction magnetic field with respect to approximately “0”. Signal.

  The Y-direction magnetic sensor 10B is composed of a bridge circuit composed of resistors r21, r22, r23 and a magnetoresistive element MR2, and between the connection point of the resistors r21, r22 and the connection point of the resistor r23 and the magnetoresistive element MR2. In addition, voltages + V and −V are applied from a constant voltage supply circuit 68b, which will be described later, of the sensor signal extraction circuit 68. In the Y direction magnetic sensor 10B, a voltage between the connection point of the resistor r22 and the magnetoresistive element MR2 and the connection point between the resistors r21 and r23 is output as a Y direction magnetic detection signal. The values of the resistors r21, r22, r23 are the same, and are equal to the resistance value of the magnetoresistive element MR2 when the magnetic field strength is “0”. As a result, the positive and negative changes in the magnetic field in the Y direction with respect to “0” as a reference cause the Y direction magnetic detection signal to change in positive and negative in proportion to the magnitude of the magnetic field in the Y direction with reference to “0”. Signal.

  The sensor signal extraction circuit 68 includes constant voltage supply circuits 68a and 68b and amplifiers 68c and 68d. The constant voltage supply circuits 68a and 68b supply constant voltages + V and −V to the X-direction magnetic sensor 10A and the Y-direction magnetic sensor 10B according to instructions from the controller 70. The amplifiers 68c and 68d amplify the X direction magnetic detection signal and the Y direction magnetic detection signal, respectively, and output the amplified signals to the lock-in amplifier 69.

  As shown in detail in FIG. 5, the lock-in amplifier 69 includes a high-pass filter 69a that inputs an X-direction magnetic detection signal supplied from the X-direction magnetic sensor 10A via the amplifier 68c, and an amplifier 68d from the Y-direction magnetic sensor 10B. And a high-pass filter 69b for inputting a Y-direction magnetic detection signal supplied via the. The high-pass filters 69a and 69b remove unnecessary components other than the signal component proportional to the strength of the magnetic field included in the X-direction magnetic detection signal and the Y-direction magnetic detection signal, and change the signal around the ground level. To.

  The output of the high pass filter 69a is supplied to the phase detection circuits 69d and 69e via the amplifier 69c. The phase detection circuits 69d and 69e are each configured by a multiplier. The phase detection circuit 69d multiplies the X direction magnetic detection signal supplied via the high pass filter 69a and the amplifier 69c by the reference signal from the energization signal supply circuit 65 and outputs the result to the low pass filter 69f. The phase detection circuit 69e adds a delayed reference signal obtained by delaying the phase of the reference signal from the energization signal supply circuit 65 by 90 degrees by the phase shift circuit 69g to the X-direction magnetic detection signal supplied via the high-pass filter 69a and the amplifier 69c. Multiply and output to low pass filter 69h. Thus, a component synchronized with the energization signal (reference signal) of the X-direction magnetic detection signal is supplied to the low-pass filter 69f, and the low-pass filter 69f performs low-pass filter processing on the supplied component signal and supplies the X-direction magnetic detection signal A signal indicating the magnitude of the component synchronized with the signal is output. The low-pass filter 69h is supplied with a component synchronized with a signal (delayed reference signal) delayed in phase by 90 degrees from the energization signal of the X-direction magnetic detection signal, and the low-pass filter 69h performs low-pass filter processing on the supplied component signal. A signal representing the magnitude of the component synchronized with the signal delayed in phase by 90 degrees from the energization signal of the X direction magnetic detection signal is output.

  The output of the high pass filter 69b is supplied to the phase detection circuits 69j and 69k via the amplifier 69i. Low-pass filters 69m and 69n are connected to the phase detection circuits 69j and 69k. The phase detection circuits 69j and 69k and the low-pass filters 69m and 69n are configured similarly to the phase detection circuits 69d and 69e and the low-pass filters 69f and 69h described above. As a result, a component synchronized with the energization signal (reference signal) of the Y-direction magnetic detection signal is supplied to the low-pass filter 69m, and the low-pass filter 69m performs low-pass filter processing on the supplied component signal, A signal indicating the magnitude of the component synchronized with the signal is output. The low-pass filter 69n is supplied with a component synchronized with a signal (delayed reference signal) delayed in phase by 90 degrees from the energization signal of the Y-direction magnetic detection signal, and the low-pass filter 69n performs low-pass processing on the supplied component signal. A signal indicating the magnitude of the component synchronized with the signal delayed by 90 degrees from the energization signal of the direction magnetic detection signal is output. The low-pass filters 69f, 69h, 69m, and 69n are connected to A / D converters 69o, 69p, 69q, and 69r, respectively. The A / D converters 69o, 69p, 69q, and 69r respectively A / D convert the signals from the low-pass filters 69f, 69h, 69m, and 69n and supply the signals to the controller 70 at predetermined time intervals.

  Returning to the description of FIG. 1 again, the controller 70 is an electronic control unit including a microcomputer including a CPU, a ROM, and a RAM, a storage device such as a hard disk and a nonvolatile memory, an input / output interface, and the like. The controller 70 executes the data acquisition program of FIGS. 6A and 6B and the evaluation program of FIGS. 7A and 7B stored in the storage device to control the operation of the secondary battery inspection device. Connected to the controller 70 are an input device 71 for an operator to instruct various parameters, processing, and the like, and a display device 72 for visually informing the operator of the operation status and the like.

  Next, the operation of the inspection apparatus for the secondary battery configured as described above will be described. As shown in FIG. 1, the worker assembles a plurality of battery setting tables 50 on the frame 42 of the stage 40 and sets a plurality of lithium ion secondary batteries BA to be inspected on the battery setting table 50. . In this case, the electrodes (positive electrode and negative electrode) of the lithium ion secondary battery BA are connected to the connector 52 of the battery setting table 50. The plurality of battery set tables 50 are connected to the energization selection circuit 67 via the connection line L1. In this state, when the power source of the secondary battery inspection device is turned on, as described above, the X direction feed motor control circuit 62 and the Y direction feed motor control circuit 64 cause the sensor support 11 ( That is, the magnetic sensor 10) is moved to the limit positions in the X direction and the Y direction, and the X direction position detection circuit 61 and the Y direction position detection circuit 63 set the detected X direction position and Y direction position to initial values.

  Thereafter, the operator operates the input device 71 to instruct the controller 70 to start inspection of the plurality of lithium ion secondary batteries BA. In response to this instruction, the controller 70 starts executing the data acquisition program in step S10 of FIG. 6A, and sets the variable s to “1” in step S12. This variable s designates each of the lithium ion secondary batteries BA set on the stage 40 via the battery setting table 50. For all the lithium ion secondary batteries BA, 1, 2, A variable s that changes in the order of 3 ·· smax is assigned. The variable s may be assigned to the lithium ion secondary battery BA in any order. In this embodiment, the variable s reciprocates from the origin position in the X and Y axis directions to the positive and negative sides in the X axis direction, and Y The variable s is assigned to the plurality of lithium ion secondary batteries BA in the order of 1, 2, 3,.

  After the processing of step S12, the controller 70 selects the lithium ion secondary battery BA specified by the variable s in step S14, and supplies the electrification selection circuit 67 so as to energize the selected lithium ion secondary battery BA. An instruction signal is output. The energization selection circuit 67 selects the lithium ion secondary battery BA that is energized through the connection L1. Next, in step S16, the controller 70 initializes the variable n to “0” and initializes the variables m and a to “1”. The variables n and m are variables indicating the scanning positions of the magnetic sensor 10 in the X direction and the Y direction with respect to the selected lithium ion battery BA. The variable a represents a state where the center position of the magnetic sensor 10 is moved to the X axis direction positive side by “1”, and the center position of the magnetic sensor 10 is moved to the X axis direction negative side by “−1”. It represents the state. Hereinafter, the center position of the magnetic sensor 10 is referred to as an inspection position.

  In this case, as shown in FIG. 10, the magnetic sensor 10 changes the end position represented by the end value Xmax in the X direction from the initial position specified by the initial values Xs and Ys for each lithium ion secondary battery BA. The movement is controlled by a predetermined minute value ΔX until it exceeds. When the end position in the X direction is reached, the magnetic sensor 10 is controlled to move by a predetermined minute value ΔY in the Y direction, and thereafter, the movement is controlled by a minute value ΔX from the end position in the X direction to the start position in the X direction. The Again, the magnetic sensor 10 is controlled to move by a minute value ΔY in the Y direction, and is controlled to move by a minute value ΔX from the start position to the end position in the X direction. Thus, the magnetic sensor 10 moves in the Y direction while reciprocating in the X direction, and scans the lithium ion secondary battery BA. The initial values Xs, Ys and end values Xmax, Ymax are determined and stored in advance for each lithium ion secondary battery BA specified by the variable s. Further, the minute values ΔX and ΔY are extremely small compared to the vertical and horizontal lengths of the lithium ion secondary battery BA (values slightly smaller than Xmax−Xs and Ymax−Ys), and are predetermined and stored values. .

  After the processing in step S16, the controller 70 moves the magnetic sensor 10 in the X-axis direction to the X-direction feed motor control circuit 62 in step S18, and the lithium ion secondary whose inspection position is specified by the variable s. The battery BA is instructed to be the initial position represented by the initial value Xs in the X-axis direction, and the magnetic sensor 10 is moved in the Y-axis direction to the Y-direction feed motor control circuit 64 so that the inspection position is a variable s. Is designated to be the initial position represented by the initial value Ys in the Y-axis direction of the lithium ion secondary battery BA designated by. In response to this instruction, the X-direction feed motor control circuit 62 inputs the X-direction detection position (inspection position in the X-axis direction) from the X-direction position detection circuit 61, and the X-direction detection position matches the initial value Xs. The X direction motor 25 is driven and controlled until The Y-direction feed motor control circuit 64 inputs the Y-direction detection position (inspection position in the Y-axis direction) from the Y-direction position detection circuit 63, and controls the Y-direction motor 34 until the Y-direction detection position matches the initial value Ys. Drive control.

  After the process of step S18, the controller 70 instructs the operation start of the energization signal supply circuit 65 in step S20. In response to this instruction, the energization signal supply circuit 65 supplies a sinusoidal energization signal to the energization circuit 66 and starts supplying a rectangular wave reference signal synchronized with the energization signal to the lock-in amplifier 69. Next, the controller 70 instructs the operation start of the energization circuit 66 in step S22. In response to this instruction, the energization circuit 66 converts the supplied energization signal into an energization signal (see FIG. 8) that changes within the operating voltage range of the lithium ion secondary battery BA and outputs the energization signal to the energization selection circuit 67. To do. The energization selection circuit 67 supplies the energization signal supplied from the energization circuit 66 to the lithium ion secondary battery BA designated by the process of step S14. As a result, the designated lithium ion secondary battery BA starts to flow an energization signal to the positive electrode, the negative electrode, and the electrolyte while repeating charging and discharging. Next, the controller 70 instructs the operation start of the sensor signal extraction circuit 68 in step S24. In response to this instruction, the constant voltage supply circuits 68a and 68b in the sensor signal extraction circuit 68 start to supply the constant voltage signals + V and −V to the X direction magnetic sensor 10A and the Y direction magnetic sensor 10B. Thereby, the X direction magnetic detection signal and the Y direction magnetic detection signal by the X direction magnetic sensor 10A and the Y direction magnetic sensor 10B start to be supplied to the lock-in amplifier 69 via the amplifiers 68c and 68d, respectively.

  The X direction magnetic detection signal and the Y direction magnetic detection signal will be described. By charging / discharging the lithium ion secondary battery BA by supplying the energization signal to the lithium ion secondary battery BA specified by the variable s described above, the anode, cathode and electrolyte in the lithium ion secondary battery BA are charged and discharged. (See FIG. 9). Due to this current, a magnetic field corresponding to the current is generated in the vicinity of the front and back surfaces of the lithium ion secondary battery BA. Then, the X direction magnetic sensor 10A starts outputting a voltage proportional to the magnitude of the magnetic field Hx in the X direction as an X direction magnetic detection signal. The Y-direction magnetic sensor 10B starts outputting a voltage proportional to the magnitude of the magnetic field Hy in the Y direction as a Y-direction magnetic detection signal. These X direction magnetic detection signal and Y direction magnetic detection signal are signals that change sinusoidally because the current changes sinusoidally.

  In the lock-in amplifier 69, the input X-direction magnetic detection signal is supplied to the phase detection circuits (multipliers) 69d and 69e via the high-pass filter 69a and the amplifier 69c, respectively, and the input Y-direction magnetic detection signal. Are supplied to phase detection circuits (multipliers) 69j and 69k through a high-pass filter 69b and an amplifier 69i, respectively. A rectangular wave reference signal from the energization signal supply circuit 65 is supplied to the phase detection circuits 69d and 69j. The phase detection circuits 69e and 69k are supplied with a delayed reference signal obtained by delaying the phase of the reference signal by 90 degrees by the phase shift circuit 69g. Then, the phase detection circuits 69d and 69e multiply the X direction magnetic detection signal supplied via the amplifier 69c by the reference signal and the delayed reference signal, respectively, and the multiplied signals are A / A via the low pass filters 69f and 69h. The D converters 69o and 69p are supplied. The phase detection circuits 69j and 69k multiply the Y direction magnetic detection signal supplied via the amplifier 69i by the reference signal and the delayed reference signal, respectively, and A / D convert the multiplied signals via the low pass filters 69m and 69n. It supplies to the devices 69q and 69r, respectively.

  Here, the low-pass filters 69f, 69h, 69j and 69k function to output a signal representing the magnitude of the component of the supplied signal, that is, a signal representing the magnitude proportional to the amplitude of the sinusoidal signal. Therefore, the A / D converter 69o is supplied with a signal indicating the magnitude of the signal component synchronized with the reference signal of the X direction magnetic detection signal. The A / D converter 69p is supplied with a signal representing the magnitude of the signal component whose phase is delayed by 90 degrees from the reference signal of the X direction magnetic detection signal. A signal representing the magnitude of the signal component synchronized with the reference signal of the Y-direction magnetic detection signal is supplied to the A / D converter 69q. The A / D converter 69r is supplied with a signal representing the magnitude of the signal component whose phase is delayed by 90 degrees from the reference signal of the Y-direction magnetic detection signal. The A / D converters 69o, 69p, 69q, and 69r sample the supplied signals at predetermined intervals, perform A / D conversion, and supply the A / D converted sampling data to the controller 70. Therefore, the sampling data representing the magnitude of each signal component every predetermined time is supplied to the controller 70 every predetermined time.

  After the process of step S24, the controller 70 adds the variable a to the variable n in step S26. In this case, since the variable n before the process of step S26 is “0” and the variable a is “1”, the variable n is changed to “1”. After the processing of step S26, the controller 70 fetches the sampling data supplied from the A / D converters 69o, 69p, 69q, 69r of the lock-in amplifier 69 in step S28, and fetches the sampling data fetched in step S30. It is determined whether or not the number of sampling data has reached a predetermined number K. The predetermined number K is set to a value representing the number of sampling data of several to several tens, for example. If the number of each sampling data has not reached the predetermined number K, the controller 70 makes a “No” determination at step S30, and at step S28, from the A / D converters 69o, 69p, 69q, 69r to the next. Takes output sampling data. When the number of sampling data fetched from the A / D converters 69o, 69p, 69q, 69r reaches a predetermined number K, the controller 70 determines “Yes” in step S30, and after step S32 Execute the process. The sampling data fetched in step S28 is stored in the RAM as a sampling data group designated by the variable s and the variables n and m.

  Specifically, a predetermined number K of sampling data fetched from the A / D converter 69o, that is, a predetermined number K of data representing the magnitude of the signal component synchronized with the reference signal of the X-direction magnetic detection signal is represented by the variable s. Is stored in the RAM as a sampling data group Sx1 (n, m) of the lithium ion secondary battery BA designated by. The predetermined number K of sampling data taken from the A / D converter 69p, that is, the predetermined number K of data representing the magnitude of the signal component synchronized with the delayed reference signal of the X direction magnetic detection signal is the same lithium ion 2 as described above. The data is stored in the RAM as the sampling data group Sx2 (n, m) of the secondary battery BA. The predetermined number K of sampling data taken from the A / D converter 69p, that is, the predetermined number K of data representing the magnitude of the signal component synchronized with the reference signal of the Y-direction magnetic detection signal is the same as the lithium ion secondary as described above. The sampling data group Sy1 (n, m) of the battery BA is stored in the RAM. The predetermined number K of sampling data fetched from the A / D converter 69r, that is, the predetermined number K of data representing the magnitude of the signal component synchronized with the delayed reference signal of the Y direction magnetic detection signal is the same lithium ion 2 as described above. The data is stored in the RAM as a sampling data group Sy2 (n, m) of the secondary battery BA. In this case, the variables n and m are both “1”.

  After the processing of steps S28 and S30, the controller 70 determines whether or not the variable a is “1” in step S32. Since the variable a is initially set to “1”, the controller 70 determines “Yes” in step S32 in this case, and the value Xs + n · ΔX is the end value Xmax in the X-axis direction in step S34. It is judged whether it is larger than. The end value Xmax is an end value stored in advance in the X-axis direction for the lithium ion secondary battery BA specified by the variable s. The value Xs + n · ΔX is a value obtained by multiplying a predetermined value ΔX representing the scanning interval in the X-axis direction by the variable n and adding the initial value Xs, and the next measurement position in the X-axis direction (scanning position in the X-axis direction) (See FIG. 10). If the value Xs + n · ΔX is equal to or less than the end value Xmax, the controller 70 determines “No” in step S34, and in step S36, the controller 70 sets the measurement position of the magnetic sensor 10 in the X-direction feed motor control circuit 62. Instructs to move to the X axis direction positive side. Thereby, the X-direction feed motor control circuit 62 starts to move the measurement position by the magnetic sensor 10 to the X axis direction positive side by operating the X direction motor 25.

  Next, the controller 70 inputs the X direction position from the X direction position detection circuit 61 in step S38, and whether or not the X direction position input in step S40 has reached the next measurement position in the X axis direction. That is, it is determined whether or not the value indicating the position in the X direction is equal to or greater than the value Xs + n · ΔX. The controller 70 continues to determine “No” in step S40 until the X-direction position input from the X-direction position detection circuit 61 reaches the next measurement position in the X-axis direction, and the processing in steps S38 and S40. Repeatedly. When the X-direction position input from the X-direction position detection circuit 61 reaches the next measurement position in the X-axis direction, the controller 70 determines “Yes” in step S40, and in step S42, the X-direction feed motor control circuit. 62 is instructed to stop the movement of the measurement position of the magnetic sensor 10 to the positive side in the X-axis direction. Thereby, the X-direction feed motor control circuit 62 stops the operation of the X-direction motor 25 and stops the movement of the measurement position by the magnetic sensor 10 to the positive side in the X-axis direction. As a result, the magnetic sensor 10 starts to detect the magnetic field at the X-axis direction position represented by the value Xs + n · ΔX and the Y-axis direction initial value Ys.

  After the process of step S42, the controller 70 returns to step S26, adds the variable a (in this case, a = 1) to the variable n by the process of step S26, and performs the sampling data of the above-described steps S28 and S30. Execute capture processing. By the processing of these steps S28 and S30, the measurement result of the magnetic sensor 10 of the X-axis direction position (the next irradiation position) represented by the value Xs + (n−1) · ΔX and the Y-axis direction initial value Ys is obtained. Sampling data is newly stored in the RAM. Specifically, a predetermined number K of sampling data representing the magnitudes of the signal components synchronized with the reference signal and the delayed reference of the X direction magnetic detection signal are the sampling data of the lithium ion secondary battery BA specified by the variable s. Groups Sx1 (n, m) and Sx2 (n, m) are stored in the RAM. In addition, a predetermined number K of sampling data representing the magnitudes of the signal components synchronized with the reference signal and the delayed reference signal of the Y-direction magnetic detection signal are the sampling data group Sy1 of the lithium ion secondary battery BA specified by the variable s. (n, m) and Sy2 (n, m) are stored in the RAM. In this case, the variable n is “2” and the variable m is “1”.

  Then, the controller 70 changes the measurement position to X by performing the processing of steps S26 to S42 until the value Xs + n · ΔX representing the next measurement position in the X-axis direction (scanning position in the X-axis direction) becomes larger than the end value Xmax. Sampling data is taken in while moving by a predetermined value ΔX to the positive side in the axial direction and increasing the variable n by “1”. When the value Xs + n · ΔX representing the next measurement position in the X-axis direction becomes larger than the end value Xmax, the controller 70 determines “Yes” in step S34 and advances the program to step S54 in FIG. 6B. . In this state, the sampling data groups Sx1 (n, m), Sx2 (n, m), Sy1 (n, m), Sy2 (n, m) (n = n = n) of the lithium ion secondary battery BA designated by the variable s. 1, 2, 3... N, m = 1) are stored in the RAM. The value N is the value of the variable n related to the sampling data group at the measurement position immediately before the end value Xmax, and represents the number of measurement positions in the X-axis direction.

  In step S54, the controller 70 instructs the Y-direction feed motor control circuit 64 to move the measurement position by the magnetic sensor 10 to the Y axis direction positive side. Thereby, the Y-direction feed motor control circuit 64 starts to move the measurement position by the magnetic sensor 10 to the Y axis direction positive side by operating the Y direction motor 34. Next, the controller 70 inputs the Y-direction position from the Y-direction position detection circuit 63 in step S56, and whether the Y-direction position input in step S58 has reached the next measurement position Ys + m · ΔY in the Y-axis direction. Determine whether or not. The next measurement position Ys + m · ΔY in the next Y-axis direction is multiplied by a variable m to a predetermined value ΔY representing the scanning interval in the Y-axis direction, similarly to the next measurement position Xs + n · ΔX in the X-axis direction. (See FIG. 10). The controller 70 continues to make a “No” determination at step S58 until the Y-direction position input from the Y-direction position detection circuit 63 reaches the next measurement position in the Y-axis direction, and the processing of steps S56 and S58. Repeatedly. When the Y-direction position input from the Y-direction position detection circuit 63 reaches the next measurement position in the Y-axis direction, the controller 70 determines “Yes” in step S58, and the Y-direction feed motor control circuit in step S60. 64 is instructed to stop the movement of the measurement position by the magnetic sensor 10 to the positive side in the Y-axis direction. Thereby, the Y-direction feed motor control circuit 62 stops the operation of the Y-direction motor 34 and stops the movement of the measurement position by the magnetic sensor 10 to the Y axis direction positive side. As a result, the magnetic sensor 10 is represented by a value Xs + (n−1) · ΔX (= Xs + (N−1) · ΔX) and an X-axis direction position, and a value Ys + m · ΔY (= Ys + ΔY). Start measuring the magnetic field at the position in the Y-axis direction.

  After the process of step S60, the controller 70 inputs the Y-direction position from the Y-direction position detection circuit 63 in step S62, and the scanning in the Y-axis direction in which the input Y-direction position is represented by the end value Ymax is completed. It is determined whether or not the position has been exceeded. The end value Ymax is a prestored end value in the Y-axis direction related to the lithium ion secondary battery BA specified by the variable s. If the position in the Y direction does not exceed the scanning end position, the controller 70 determines “No” in step S62, adds “1” to the variable m in step S64, and sets the variable a in step S66. Multiply by “−1”. In this case, the variable m becomes “2” by the process of step S64, and the variable a becomes “−1” by the process of step S66. The variable n is kept at the value N. After the process of step S66, the controller 70 returns to step S28 of FIG. 5A, and each of the K sampling data groups Sx1 (N, 2), Sx2 (N, 2), Sy1 (N, 2) and Sy2 (N, 2) are fetched from the lock-in amplifier 69 and stored.

  After the processing of steps S28 and S30, the controller 70 determines whether or not the variable a is “1” in step S32. In this case, since the variable a is set to “−1” by the process of step S66, the controller 70 determines “No” in step S32, and the value Xs + (n−2) in step S44. ) · ΔX is determined whether or not it is smaller than the initial value Xs in the X-axis direction. In this case, the variable n is N, and the value Xs + (n−2) · ΔX is a value representing the second detection position from the right end in FIG. If the value Xs + (n−2) · ΔX is not smaller than the initial value Xs, the controller 70 determines “No” in step S44, and in step S46, instructs the X-direction feed motor control circuit 62 to An instruction is given to move the measurement position by the sensor 10 to the X axis direction negative side. Thereby, the X-direction feed motor control circuit 62 operates the X-direction motor 25 to start moving the measurement position by the magnetic sensor 10 to the X-axis direction negative side.

  Next, the controller 70 inputs the X direction position from the X direction position detection circuit 61 in step S48, and whether or not the X direction position input in step S50 has reached the next measurement position in the X axis direction. That is, it is determined whether or not the value indicating the position in the X direction is equal to or less than the value Xs + (n−2) · ΔX. The controller 70 continues to make a “No” determination in step S50 until the X-direction position input from the X-direction position detection circuit 61 reaches the next measurement position in the X-axis direction, and the processing in steps S48 and S50. Repeatedly. When the X-direction position input from the X-direction position detection circuit 61 reaches the next measurement position in the X-axis direction, the controller 70 determines “Yes” in step S50, and in step S52, the X-direction feed motor control circuit. 62 is instructed to stop the movement of the measurement position by the magnetic sensor 10 to the negative side in the X-axis direction. Thereby, the X-direction feed motor control circuit 62 stops the operation of the X-direction motor 25 and stops the movement of the measurement shooting position by the magnetic sensor 10 to the negative side in the X-axis direction. As a result, the magnetic sensor 10 has the X-axis direction position represented by the value Xs + (n−2) · ΔX (= Xs + (N−2) · ΔX) and the value Ys + (m−1) · ΔYs (= Ys + ΔYs). The magnetic field at the position in the Y-axis direction represented by

  After the process of step S52, the controller 70 returns to step S26, adds the variable a (in this case, a = -1) to the variable n by the process of step S26, and samples the sampling data of the above-described steps S28 and S30. Execute the import process. By the processing in steps S28 and S30, the position in the X-axis direction represented by the value Xs + (n−2) · ΔX (= Xs + (N−2) · ΔX) before the processing in step S26, and the value Ys + ( m−1) · YS (= Ys + ΔYs), each of K sampling data groups Sx1 (n, m), Sx2 (n, m), Sy1 (n, m), Sy2 (n, m) is captured and stored. Note that the variable n regarding the sampling data group to be captured and stored is the value N−1, and the variable m is “2”.

  Then, the controller 70 proceeds to steps S26 to S32, S44, and so on until the value Xs + (n−2) · ΔX representing the next measurement position in the X-axis direction (scanning position in the X-axis direction) becomes smaller than the initial value Xs. By the processing of S52, the measurement position is moved to the negative side in the X-axis direction by a predetermined value ΔX, and sampling data is taken in while decreasing the variable n by “1”. Then, when the value Xs + (n−2) · ΔX representing the next measurement in the X-axis direction becomes smaller than the initial value Xs, the controller 70 determines “Yes” in step S44 and performs step S54 in FIG. 6B. Proceed to Note that the variable n at this time is “1”. In this state, the sampling data groups Sx1 (n, m), Sx2 (n, m), Sy1 (n, m), Sy2 (n, m) (n = 1, 2, 3... N, m = 1), sampling data groups Sx1 (n, m), Sx2 (n, m), Sy1 (n, m), Sy2 (n, m) (n = 1, 2, 3... N, m = 2) is stored in the RAM.

  The controller 70 operates the Y direction motor 34 and moves the measurement position by the magnetic sensor 10 to the next Y-axis direction irradiation position Ys + m · ΔY by the processes of steps S54 to S60 described above. As a result, the magnetic sensor 10 starts to detect the magnetic field at the initial position in the X-axis direction represented by the initial value Xs and at the position in the Y-axis direction represented by the value Ys + m · ΔY (= Ys + 2 · ΔY). Next, on the condition that the Y-direction position detected by the Y-direction position detection circuit 63 does not exceed the end position, the controller 70 determines “No” in step S62, and step S64. In step S66, “1” is added to the variable m, and in step S66, the variable a is multiplied by “−1”. In this case, the variable m becomes “3” by the process of step S64, and the variable a becomes “1” by the process of step S66. The variable n is kept at “1”. After the process of step S66, the controller 70 returns to step S28, and from the processes of steps S28 and S30, the K sampling data groups Sx1 (1, 1) for the lithium ion secondary battery BA specified by the variable s. 3), Sx2 (1,3), Sy1 (1,3), Sy2 (1,3) are taken in from the lock-in amplifier 69 and stored.

  After the processing of steps S28 and S30, the controller 70 determines whether or not the variable a is “1” in step S32. In this case, since the variable a is set to “1” by the process of step S66, the controller 70 determines “Yes” in step S32, and the processes of steps S34 to S42 and S26 to S32 described above. Are repeatedly executed until the value Xs + n · ΔX becomes larger than the end value Xmax. As a result, the measurement position of the magnetic sensor 10 is scanned to the positive side in the X-axis direction, and sampling data groups Sx1 (n, m), Sx2 (n, m), of the lithium ion secondary battery BA specified by the variable s. Sy1 (n, m), Sy2 (n, m) (n = 1, 2, 3... N, m = 3) are newly stored in the RAM.

  When the variable m is set to “3” and the scanning of the measurement position of the magnetic sensor 10 to the positive side in the X-axis direction is completed, the processes of steps S54 to S66 are executed by the determination process of step S34. The measurement position of the magnetic sensor 10 is changed to the next position in the Y-axis direction, and the variables m and a are changed. Then, the measurement position of the magnetic sensor 10 is scanned to the negative side in the X-axis direction by the processes of steps S26 to S32 and S44 to S52 described above, and the sampling data group Sx1 () of the lithium ion secondary battery BA specified by the variable s. n, m), Sx2 (n, m), Sy1 (n, m), Sy2 (n, m) (n = 1, 2, 3... N, m = 4) are newly stored in the RAM. .

  Through the processing of steps S26 to S66, the measurement position of the magnetic sensor 10 is scanned so as to reciprocate in the X-axis direction, and is scanned to the Y-axis direction positive side, and is detected by the Y-direction position detection circuit 63. When the position in the Y direction becomes larger than the end value Ymax, the controller 70 determines “Yes” in step S62, and proceeds to step S68. In step S68, the controller 70 determines whether or not the next inspection target lithium ion secondary battery BA exists, that is, whether or not the variable s has reached the number Smax of the lithium ion secondary voltage BA. In this case, since the variable s is “1” and has not reached the number of the lithium ion secondary voltage BA, the controller 70 determines “Yes” in step S68 and sets the variable s in step S70. “1” is added, and the process returns to step S14 in FIG. 6A. In this state, the K sampling data groups Sx1 (n, m), Sx2 (n, m), Sy1 (n) for the lithium ion secondary battery BA specified by the variable s (= 1) are stored in the RAM. , m), Sy2 (n, m) (n = 1 to N, m = 1 to M) are stored. The value M is the value of the variable m related to the sampling data group at the measurement position immediately before the end value Ymax, and represents the number of measurement positions in the Y-axis direction.

  In step S14, the controller 70 selects the lithium ion secondary battery BA specified by the variable s, and outputs an instruction signal to the energization selection circuit 67 so as to energize the selected lithium ion secondary battery BA. The energization selection circuit 67 selects the lithium ion secondary battery BA that is energized through the connection L1. Next, the controller 70 initializes the variable n to “0” by the process of step S16 described above, initializes the variables m and a to “1”, respectively, and performs the magnetic sensor by the process of step S18 described above. The ten measurement positions are positioned at the initial positions in the X and Y axis directions represented by the initial values Xs and Ys of the lithium ion secondary battery BA specified by the variable s (= 2). Then, the start of operation of the energization signal supply circuit 65, the energization circuit 66, and the sensor signal extraction circuit 68 is instructed by the processing of steps S20 to S24 described above. However, in this case, since the energization signal supply circuit 65, the energization circuit 66, and the sensor signal extraction circuit 68 are operating, in practice, the energization signal supply circuit 65, the energization circuit 66, and the sensor signal extraction circuit 68 continue to operate. Only.

  After the process of step S24, the controller 70 executes the process of step S26 of FIG. 6A to step S66 of FIG. 6B described above. As a result, the K sampling data groups Sx1 (n, m), Sx2 (n, m), Sy1 (n, n) for the lithium ion secondary battery BA specified by the variable s (= 2) are stored in the RAM. m), Sy2 (n, m) (n = 1 to N, m = 1 to M) are stored. Thereafter, the controller 70 determines “Yes” in step S68 until the next lithium-ion secondary battery BA to be inspected does not exist, that is, until the variable s reaches the number smax of the lithium-ion secondary voltage BA. Then, the process from step S14 in FIG. 6A to step S70 in FIG. 6B is repeatedly executed while increasing the variable s by “1” in step S70. When the variable s reaches the number smax of the lithium ion secondary voltage BA, the controller 70 determines “No” in step S68. Proceed to step S72 and subsequent steps. In this state, K sampling data groups Sx1 (n, m) and Sx2 (n, n) are stored in the RAM for all the lithium ion secondary batteries BA specified by the variable s (1 to smax). m), Sy1 (n, m), Sy2 (n, m) (n = 1 to N, m = 1 to M) are stored.

  The controller 70 instructs the operation stop of the sensor signal extraction circuit 68 in step S72, instructs the operation stop of the energization circuit 66 in step S74, and instructs the operation stop of the energization signal supply circuit 65 in step S76. The operation of the magnetic sensor 10, the energization signal supply circuit 65, the energization circuit 66, the energization selection circuit 67, the sensor signal extraction circuit 68, and the lock-in amplifier 69 is stopped according to these operation stop instructions. After the process of step S76, the controller 70 moves the sensor support base 11 (that is, the magnetic sensor 10) to the X direction drive limit position in step S78, and the X direction position detection circuit 61 and the X direction feed motor control circuit. And instructing the Y-direction position detection circuit 63 and the Y-direction feed motor control circuit 64 to move the sensor support 11 to the Y-direction drive limit position, and executing the data acquisition program in step S80. finish. The X-direction feed motor control circuit 62 moves the sensor support 11 to the X-direction drive limit position in cooperation with the X-direction position detection circuit 61 as in the initial setting described above. As described above, the Y-direction feed motor control circuit 64 moves the sensor support 11 to the Y-direction drive limit position in cooperation with the Y-direction position detection circuit 63.

  Next, a predetermined number K of sampling data groups Sx1 (n, m), Sx2 (n, m), Sy1 (n, n) for each lithium ion secondary battery BA specified by the variable s acquired by the data acquisition program. m), Sy2 (n, m) (n = 1 to N, m = 1 to M), a method for evaluating a lithium ion secondary battery will be described. In this case, the operator operates the input device 71 to cause the controller 70 to execute the evaluation programs of FIGS. 7A and 7B. The execution of this evaluation program is started in step S100, and the controller 70 sets the variable s to “1” in step S102. This variable s (= 1 to smax) is the same as that of the data acquisition program described above, and designates each of smax lithium ion secondary batteries BA. Next, after initializing the variables n and m to “1” in step S104, the controller 70 relates to the lithium ion secondary battery BA specified by the variable s in step S106, using the variables n and m. Each of the average values Sx1, Sx2 of the magnitudes of the magnetic fields of the sampling data groups Sx1 (n, m), Sx2 (n, m), Sy1 (n, m), Sy2 (n, m) of a predetermined number K specified. , Sy1, Sy2 are calculated. Specifically, for each sampling data group Sx1 (n, m), Sx2 (n, m), Sy1 (n, m), Sy2 (n, m) regarding the lithium ion secondary battery BA specified by the variable s. And K sampling data are added and divided by the value K.

Next, in step S108, the controller 70 performs the following calculations 1 and 2 using the calculated average values Sx1 and Sx2, and thereby the local maximum value Hx of the X direction magnetic detection signal and the X direction magnetic detection signal. The phase shift amount θx with respect to the reference signal is calculated.
Hx = (Sx1 ² + Sx2 ² ) ^1/2 Formula 1
θx = tan ^-1 (Sx2 / Sx1) ... Formula 2
As a result, Hx · sin (2πft + θx) is detected as the X-direction magnetic detection signal. Note that f is equal to the frequency of the energization signal and the reference signal output from the energization signal supply circuit 65.

Next, in step S110, the controller 70 performs the calculations of the following equations 3 and 4 using the calculated average values Sy1 and Sy2, and thereby the maximum value Hy of the Y-direction magnetic detection signal and the Y-direction magnetic detection signal. The phase shift amount θy with respect to the reference signal is calculated.
Hy = (Sy1 ² + Sy2 ² ) ^1/2 Formula 3
θy = tan ^-1 (Sy2 / Sy1) ... Equation 4
As a result, Hy · sin (2πft + θy) is detected as the Y-direction magnetic detection signal.

Next, in step S112, the controller 70 executes the following Equations 5 and 6 using the calculated Hx, θx, Hy, and θy, and thereby the timing at which the energization current amount becomes maximum (the X-direction magnetic detection). The magnetic field strength Hxy and the magnetic field direction θxy at the inspection position at the signal Hx · sin (2πft + θx) and the 2πft in the Y-direction magnetic detection signal Hy · sin (2πft + θy) are π / 2 are calculated. In this case, the reason why the timing at which the energization current amount is maximum is adopted is that the phase shift amounts θx and θy are small, and the magnetic field strength Hxy at the inspection position is a value near the maximum value in the vicinity of the timing at which the energization current amount is maximum. Because it becomes. When the phase shift amounts θx and θy are not small and the magnetic field strength Hxy at the inspection position does not become close to the maximum value near the timing when the energization current amount becomes maximum, the magnetic field strength Hxy is close to the maximum value. The timing angle may be used instead of π / 2.
Hxy = [{Hx · sin (π / 2 + θx)} ² + {Hy · sin (π / 2 + θy)} ² ] ^1/2
θxy = tan ⁻¹ {Hy · sin (π / 2 + θy)} / {Hx · sin (π / 2 + θx)} Equation 6

Next, in step S114, the controller 70 determines that the current flowing through each part in the lithium ion secondary battery BA is proportional to the magnetic field strength Hxy and the direction is different from the magnetic field direction θxy by −π / 2. The magnitude Ixy and the direction θixy of the current flowing at the inspection position of the lithium ion secondary battery BA at the timing when the amount of energization current becomes maximum by executing the calculations of the following formulas 7 and 8 using the calculated Hxy and θxy. Calculate However, the value K is a proportionality constant.
Ixy = K · Hxy Equation 7
θixy = θixy−π / 2 Equation 8

  In step S114, the calculated current magnitude Ixy and direction θixy are data relating to the lithium ion secondary battery BA specified by the variable s, and the inspection position of the lithium ion secondary battery BA is determined. Using the variables n and m to represent, the current magnitude data Ixy (n, m) and the direction data θixy (n, m) are stored in the RAM or the storage device.

Next, in step S116, the controller 70 executes currents flowing in the X direction and the Y direction at the inspection position of the lithium ion secondary battery BA by executing the calculations of the following formulas 9 and 10 using the calculated Ixy and θixy. The magnitudes Ix and Iy are calculated.
Ix = Ixy · cosθixy (Equation 9)
Iy = Ixy · sinθixy (Formula 10)
In step S116, the calculated current magnitudes Ix and Iy are also data related to the lithium ion secondary battery BA specified by the variable s and represent the inspection position of the lithium ion secondary battery BA. Using the variables n and m, current magnitude data Ix (n, m) and Iy (n, m) are stored in the RAM or storage device.

  After the process of step S116, the controller 70 executes the determination process of steps S118 and S120. In step S118, the absolute value | Ix−Ixref (n, m) of the difference between the calculated magnitude Ix flowing in the X direction and the reference value Ixref (n, m) of the magnitude of current flowing in the X direction. ) | Is greater than or equal to the comparison value 3 · DEVix (n, m). In step S120, the absolute value | Iy−Iyref (n, m) of the difference between the calculated magnitude Iy of the current flowing in the Y direction and the reference value Iyref (n, m) of the magnitude of the current flowing in the Y direction. ) | Is greater than or equal to the comparison value 3 · DEViy (n, m).

  In this case, the reference values Ixref (n, m) and Iyref (n, m) and the comparison values 3 · DEVix (n, m) and 3 · DEViy (n, m) are prepared in advance by the following method. Data stored in advance in the storage device. First, sampling data groups Sx1 (n, m), Sx2 (n, m), Sy1 (n, m), Sy2 (n, m) (n = 1 to 1) relating to a plurality of non-defective lithium ion secondary batteries BA. N, m = 1 to M) is acquired by a data acquisition program as shown in FIGS. 6A and 6B. Then, the magnitudes Ix (n, m), Iy (n, m) (n of the currents flowing in the X direction and the Y direction for each inspection position are obtained by the same processing as the steps S106 to S116 of the evaluation program of FIG. 7A described above. = 1 to N, m = 1 to M) are calculated and stored in the storage device. Further, each average value of the magnitudes Ix (n, m) and Iy (n, m) of the current flowing in the X direction and the Y direction of the plurality of lithium ion secondary batteries BA is calculated for each inspection position. These calculated average values are stored in the storage device as reference values Ixref (n, m) and Iyref (n, m) (n = 1 to N, m = 1 to M). Further, the standard deviation DEVix (n, m) of the magnitudes Ix (n, m) and Iy (n, m) of the currents flowing in the X and Y directions of the plurality of lithium ion secondary batteries BA for each inspection position. , DEViy (n, m) is calculated, and the calculated standard deviations DEVix (n, m) and DEViy (n, m) are tripled to the comparison values 3 · DEVix (n, m), 3 · DEViy ( n, m) (n = 1 to N, m = 1 to M) is stored in the storage device. Therefore, the determinations in steps S118 and S120 are based on the magnitudes of currents Ix (n, m) and Iy (n, m) flowing in the X and Y directions at the inspection position of the lithium ion secondary battery BA to be inspected. It is determined whether or not the magnitude of the current flowing in the X direction and the Y direction at the same position as the inspection position of the non-defective lithium ion secondary battery BA is larger than the allowable value.

  Returning to the description of the processing in steps S118 and S120, the absolute value | Ix−Ixref (n, m) | is less than the comparison value 3 · DEVix (n, m) and the absolute value | Iy−Iyref ( n, m) | is less than the comparison value 3 · DEViy (n, m), the controller 70 determines “No” in steps S118 and S120, and proceeds to step S124. On the other hand, if the absolute value | Ix−Ixref (n, m) | is equal to or greater than the comparison value 3 · DEVix (n, m), the controller 70 determines “Yes” in step S118 and proceeds to step S122. move on. If the absolute value | Iy−Iyref (n, m) | is equal to or greater than the comparison value 3 · DEViy (n, m), the controller 70 determines “Yes” in step S120, and then proceeds to step S122. move on. In step S122, the controller 70 sets the error data E (n, m) specified by the variables n and m specifying the inspection position to “1” indicating abnormality. The error data E (n, m) (n = 1 to N, m = 1 to M) are all set to “0” in the initial state. After the process of step S122, the process proceeds to step S124.

  The controller 70 adds “1” to the variable n in step S124, and determines whether or not the variable n is larger than a value N representing the number of detected positions in the X-axis direction in step S126. If the variable n is less than or equal to the value N, the controller 70 determines “No” in step S126, returns to step S106, and repeatedly executes the processes of steps S106 to S124 described above. If the variable n becomes larger than the value N during the repetitive processing of steps S106 to S126, the controller 70 determines “Yes” in step S126 and defines the inspection position in the Y-axis direction in step S128. In step S130, it is determined whether or not the variable m is larger than a value M representing the number of detected positions in the Y-axis direction. If the variable m is equal to or less than the value M, the controller 70 determines “No” in step S130, returns the variable n to the initial value “1” in step S132, and then performs the above-described steps S106 to S132. Repeat the process. If the variable m becomes larger than the value M during the repetition process of steps S106 to S132, the controller 70 determines “Yes” in step S130 and proceeds to step S134.

  At this time, the current magnitude data Ixy (n, m), the current direction data θixy (n, m), and the current flowing in the X direction at each inspection position of the lithium ion secondary battery BA specified by the variable s. Magnitude data Ix (n, m) and magnitude data Iy (n, m) (n = 1 to N, m = 1 to M) of current flowing in the Y direction are stored in the RAM or the storage device. . Further, error data E (n, m) (n = 1 to N, m = 1 to M) indicating whether or not the inspection position is abnormal is also stored in the RAM or the storage device.

In step S134, the controller 70 determines the current magnitude data Ixy (n, m), the direction data θixy (n, m) (n = 1 to N, m = 1 to M), the X direction and the Y direction. Magnitude data Ix (n, m), Iy (n, m)
Display image data is generated from (n = 1 to N, m = 1 to M), and the image represented by the image data is used to specify the lithium ion secondary battery BA specified by the variable s. At the same time, it is displayed on the display device 72. In this image, for example, the length of the arrow varies depending on the current magnitude data Ixy (n, m) for each inspection position of the lithium ion secondary battery BA, and the current direction data θixy (n, m) It is better to display the arrows in different directions. In addition, a display that changes the brightness, color, and the like of the inspection position according to the current magnitude data Ixy (n, m) may be included. Further, regarding the magnitude data Ix (n, m) and Iy (n, m) of the current flowing in the X direction and the Y direction, the current magnitude data Ixy (n, m) and the direction data θixy (n, m) ) May be used, but in this case, since the direction of the current is constant, the brightness, color, etc. of the inspection position are represented by current magnitude data Ix (n, m), Iy (n, It may be different depending on m).

  After the process of step S134, the controller 70 determines in step S136 whether there is error data indicating “1” in the error data (n, m) (n = 1 to N, m = 1 to M). Check out. If there is no error data indicating “1”, the controller 70 determines “No” in step S136, displays “pass” on the display device 72 in step S138, and proceeds to step S144. On the other hand, if there is error data indicating “1”, the controller 70 determines “Yes” in Step S136, displays “Fail” on the display device 72 in Step S140, and returns an error in Step S142. Variables n and m whose data E (n, m) is “1” are taken out, and a mark, color, etc. representing a defect are displayed at the position specified by the variables n and m in the image displayed by the processing of step S134. To do.

  Next, the controller 70 determines whether or not there is an instruction to evaluate the next lithium ion secondary battery BA in step S144. In this case, if the operator does not instruct switching to the next lithium ion secondary battery BA, the controller 70 continues to determine “No” in step S144, and repeatedly executes the determination processing in step S144. On the other hand, if the operator uses the input device 71 to instruct switching to the next lithium ion secondary battery BA, the controller 70 determines “Yes” in step S144 and proceeds to step S146. In step S146, the controller 70 determines whether or not the variable s has reached the number smax of the lithium ion secondary batteries BA. If the variable s has not yet reached the number smax, the controller 70 determines “No” in step S146, adds “1” to the variable s in step S148, and proceeds to step S104 in FIG. 7A. Return.

  Then, the processes in steps S104 to S142 described above are executed, and current magnitude data Ixy (n, m) and current direction data θixy (n, n) related to the next lithium ion secondary battery BA specified by the variable s. m), the magnitude data Ix (n, m) of the current flowing in the X direction and the magnitude data Iy (n, m) of the current flowing in the Y direction are calculated and stored in the RAM or the storage device. 72. Further, the pass / fail of the lithium ion secondary battery BA is determined using the magnitude data Ix (n, m) of the current flowing in the X direction and the magnitude data Iy (n, m) of the current flowing in the Y direction. In addition, the determination result is also displayed on the display device 72. Then, until the variable s reaches the number smax of the lithium ion secondary batteries BA, in response to the designation of the next lithium ion secondary battery BA by the operator, “Yes” in step S144 and “No” in step S146. In step S148, the variable s is sequentially incremented, and the process consisting of steps S104 to S142 is sequentially performed on the lithium ion secondary battery BA specified by the incremented variable s, so that a plurality of lithium ions are obtained. Secondary batteries BA are evaluated one after another. As a result, when the variable s reaches the number smax of the lithium ion secondary batteries BA, the controller 70 determines “Yes” in step S146, and ends the execution of the evaluation program in step S150.

  In the embodiment operating as described above, the energization signal supply circuit 65 and the energization circuit 66 apply a DC voltage on which an alternating current component of a predetermined frequency is superimposed between the positive electrode and the negative electrode of the lithium ion secondary battery BA. As a result, a current corresponding to the AC component flows in the anode, cathode, and electrolyte in the lithium ion secondary battery BA, and a magnetic field is generated in a portion facing the lithium ion secondary battery BA. Then, this magnetic field is detected by the magnetic sensor 10, and the lithium ion secondary battery BA is evaluated based on the current flowing through each part in the lithium ion secondary battery BA calculated based on the detected magnetic field.

  In this case, the DC voltage on which the AC component is superimposed is a DC voltage that changes within the operating voltage range of the lithium ion secondary battery BA. The lithium ion secondary battery BA is repeatedly charged and discharged, and the lithium ion secondary battery BA is applied to the lithium ion secondary battery BA. A current flows. As a result, after the inspection, neither the overcharge state nor the overdischarge state occurs, and even during the inspection, the maximum value and the minimum value of the voltage applied between the electrodes of the secondary battery are always the operations of the secondary battery. Since it is maintained within the voltage range, there is no adverse effect on the secondary battery due to charging and discharging, and the secondary battery is inspected satisfactorily. Further, since only the signal representing the magnetic field generated in relation to the AC component of the predetermined frequency is taken out by the lock-in amplifier 69, a magnetic field that is not affected by the external magnetic field can be detected with a relatively simple configuration. . As a result, there is no need to make the external magnetic field uniform while suppressing the cost of the inspection apparatus for the secondary battery, and the magnetic field generated by the current flowing through the plurality of portions of the lithium ion secondary battery BA is reduced. Since it can be detected with high accuracy, an abnormality of the lithium ion secondary battery BA can be detected with high accuracy.

  Further, in the above embodiment, the magnetic field at the position facing each part of the lithium ion secondary battery BA is detected by the processing of steps S26 to S66, and the current magnitude Ixy and the current direction θixy are processed by the processing of steps S106 to S116. The distribution of the current magnitude Ix flowing in the X direction and the current magnitude Iy flowing in the Y direction is calculated. Then, by the processing in steps S118 to S122, the calculated magnitude Ix of the current flowing in the X direction and the magnitude Iy of the current flowing in the Y direction are compared with the reference information prepared in advance, and the lithium ion secondary Since abnormality of battery BA is determined, abnormality of lithium ion secondary battery BA is easily detected. Further, the distribution of the calculated current magnitude Ixy, current direction θixy, current magnitude Ix flowing in the X direction, and current magnitude Iy flowing in the Y direction is displayed on the display device 72 by the process of step S134. Therefore, it is possible to visually determine the abnormality of the lithium ion secondary battery BA.

  Although one embodiment of the present invention has been described above, the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the object of the present invention.

  In the above embodiment, the energization voltage applied to the lithium ion secondary battery BA by the energization circuit 66 is always prevented from exceeding the operating voltage range of the lithium ion secondary battery BA. However, the center voltage of fluctuation of the energization voltage, that is, the DC voltage on which the AC signal is superimposed is within the operating voltage range of the lithium ion secondary battery BA, that is, the lower limit value of the discharge voltage of the lithium ion secondary battery BA and the charge voltage There is no major problem as long as it is below the upper limit. In this case, if the DC voltage on which the AC signal is superimposed is close to the upper limit of the operating voltage range (that is, the charging voltage) of the lithium ion secondary battery BA, during the inspection, the energization voltage (voltage at the time of charging) is the lithium ion 2. The upper limit of the operating voltage range of the secondary battery BA may be exceeded. Further, if the DC voltage on which the AC signal is superimposed is close to the lower limit of the operating voltage range (that is, the discharge voltage) of the lithium ion secondary battery BA, the energization voltage (the voltage at the time of discharge) is increased during the inspection. In some cases, the operating voltage range of the battery BA is lower than the lower limit. However, since the output voltage of the lithium ion secondary battery BA after the inspection is within the operating voltage range and the lithium ion secondary battery BA after the inspection does not enter the overcharge state or the overdischarge state, the lithium ion secondary battery BA The effect on the battery BA is not so great.

  Further, in the above-described embodiment, the DC voltage on which the AC signal that changes around “0” supplied from the energization signal supply circuit 65 is superimposed by the energization circuit 66 is always constant. However, instead of this, the DC voltage on which the AC signal is superimposed may be the same as the output voltage of the lithium ion secondary battery BA before the inspection. In this case, the output voltage of the lithium ion secondary battery BA may be automatically measured before the inspection, and the energization circuit 66 may automatically superimpose the AC signal on the measured output voltage. In addition, the operator measures the output voltage of the lithium ion secondary battery BA before the inspection, and inputs the measured voltage to the controller 70 using the input device 71. The controller 70 controls the energization circuit 66 to measure the voltage. The AC signal may be superimposed on the voltage. Also in this case, if the output voltage of the lithium ion secondary battery BA before the inspection is close to the upper limit or the lower limit of the operating voltage range of the lithium ion secondary battery BA, as described above, The operating voltage range of the lithium ion secondary battery BA may be exceeded. However, also in this case, as described above, the problem given to the lithium ion secondary battery BA is not so great.

  On the other hand, according to this modification, the voltage applied between the anode and the cathode of the lithium ion secondary battery BA by the energization circuit 66 changes up and down around the output voltage of the lithium ion secondary battery BA before the inspection. Thus, charging and discharging are repeated, so that the output voltage of the lithium ion secondary battery BA after the inspection becomes the same as the output voltage before the inspection. As a result, the state of the lithium ion secondary battery BA can be kept almost the same before and during the inspection, and can be kept the same as before the inspection after the inspection. An abnormality of the lithium ion secondary battery BA can be detected, and other inspections and operations can be realized while maintaining the same state.

In the above embodiment, the current magnitude Ixy and direction θixy, the current magnitude Ix in the X direction, and the current magnitude Iy in the Y direction are calculated from the magnetic field detected by the magnetic sensor 10, and step S134 is performed. Through these processes, the distribution state is displayed on the display device 72. However, the strength of the magnetic field and the magnitude of the current are in a proportional relationship, and the direction of the magnetic field and the direction of the current are only 90 degrees different. Therefore, the magnitude of the current Ixy and the direction θixy and the magnitude of the current in the X direction are different. The display device 72 shows the distribution state of the magnetic field strength Hxy and the direction θxy, the magnetic field strength Hy in the Y direction, and the magnetic field strength Hx in the X direction instead of the current Ix and the current magnitude Iy in the Y direction. You may make it display. In this case, the magnetic field strength Hxy and the direction θxy calculated by the processing in step S112, and the X-direction magnetic field strength Hx and the Y-direction magnetic field strength calculated by the following equations 11 and 12 may be used. .
Hx = Hxy · cosθxy Equation 11
Hy = Hxy · sinθxy… Formula 12

  Further, in the above embodiment, the abnormality of the lithium ion secondary battery BA is determined using the magnitude Ix flowing in the X direction and the magnitude Iy flowing in the Y direction in steps S118 and S120. did. However, as described above, the strength of the magnetic field and the magnitude of the current are in a proportional relationship, and the direction of the magnetic field and the direction of the current are only 90 degrees different from each other. Therefore, instead of the magnitudes of the currents Ix and Iy, The abnormality of the lithium ion secondary battery BA may be determined using the magnetic field strength Hx in the X direction and the magnetic field strength Hy in the Y direction calculated by the above formulas 11 and 12. In this case, the absolute value | Hy−Hyref (n, m) | of the difference between the magnetic field strength Hy in the Y direction and the reference value Hyref (n, m) is equal to or greater than the comparison value 3 · DEVhy (n, m). Or the absolute value | Hx−Hxref (n, m) | of the difference between the magnetic field strength Hx in the X direction and the reference value Hxref (n, m) is equal to or greater than the comparison value 3 · DEVhx (n, m). The lithium ion secondary battery BA may be determined to be abnormal. In this case, the reference values Hyref (n, m), Hxref (n, m) and the comparison values 3 · DEVhy (n, m), 3 · DEVhx (n, m) are normal lithium ion secondary batteries. The value measured in advance using BA and stored in the storage device is used.

  In the above embodiment, the processing of steps S116 to S120 compares the distribution of currents Ix and Iy flowing in the X direction and Y direction obtained by measurement with the reference current distribution and compares the current distribution of the lithium ion secondary battery. A pass / fail decision was made. However, when the anode and the cathode are arranged symmetrically with respect to the center line in the X direction or the Y direction, the pass / fail of the lithium ion secondary battery BA may be determined from the symmetry of the current magnitude. Good. In this case, the difference between the two current magnitudes Ix in the X direction (or the two current magnitudes Iy in the Y direction) symmetrical to the center line in the X direction (or Y direction) is accumulated and summed. If the value or the value obtained by dividing the integrated value by the integrated number is smaller than the predetermined value, it is determined to be acceptable, and if it is equal to or greater than the predetermined value, it is determined to be unacceptable. Also in this case, the magnetic field strengths Hy and Hx may be used instead of the current magnitudes Ix and Iy.

  Moreover, in the said embodiment, the stage 40 which can set several lithium ion secondary battery BA was used, and it was made to test | inspect several lithium ion secondary battery at once. However, when inspecting the lithium ion secondary batteries BA one by one, a stage 40 on which only one lithium ion secondary battery BA can be set is prepared. What is necessary is just to scan the circumference | surroundings with the magnetic sensor 10. FIG. According to this, when inspecting a plurality of lithium ion secondary batteries, the inspection time is longer than that in the above embodiment, but the inspection device can be configured compactly.

  Moreover, in the said embodiment, the one magnetic sensor 10 was moved to the X direction and the Y direction, and several lithium ion secondary battery BA was test | inspected. However, a large number of magnetic sensors may be arranged in a matrix form below the stage 40, and a plurality of lithium ion secondary batteries BA may be inspected without moving the large number of magnetic sensors. In addition, a plurality of magnetic sensors are provided in one row along the X direction, a plurality of magnetic sensors are provided in one row along the Y direction, or a small number of magnetic sensors are provided in a matrix in the X and Y directions. Then, the plurality of lithium ion batteries may be inspected by appropriately moving these magnetic sensor groups and scanning the plurality of lithium ion secondary batteries.

  In the above embodiment, a magnetoresistive element (MR element) is used as the magnetic sensor. Instead, a Hall element, a magneto-impedance element effect sensor, a flux gate, a superconducting quantum interference element, or the like is used. May be.

  Moreover, in the said embodiment, although the test | inspection apparatus based on this invention was utilized for the test | inspection of lithium ion secondary battery BA, the test | inspection apparatus based on this invention is lithium, such as a nickel cadmium secondary battery and a nickel hydride secondary battery. The present invention can also be applied to rechargeable secondary batteries other than the ion secondary battery BA. In this case, a battery setting table 50 different from that of the above embodiment may be prepared according to the shape and size of the secondary battery. Further, even if it is a lithium ion secondary battery, if the shape and size are different from the case of the above embodiment, a battery set x table 50 suitable for the lithium ion secondary battery is prepared. Good.

10-point magnetic sensor, 20 ... X-direction slide mechanism, 25 ... X-direction motor, 30 ... Y-direction slide mechanism, 34 ... Y-direction motor, 40 ... stage, 50 ... Table for battery setting, 61 ... X-direction position detection circuit, 62 ... X direction feed motor control circuit, 63 ... Y direction position detection circuit, 64 ... Y direction feed motor control circuit, 65 ... energization signal supply circuit, 66 ... energization circuit, 67 ... energization selection circuit, 68 ... sensor signal extraction circuit 69 ... Lock-in amplifier, 70 ... Controller

Claims (9)

An energization means for applying a DC voltage, in which an alternating current component of a predetermined frequency is superimposed on a DC voltage within the operating voltage range of the secondary battery, between the electrodes of the secondary battery to flow current to the secondary battery;
A magnetic field detecting means positioned opposite to a plurality of parts of the secondary battery, detecting a magnetic field generated by a current flowing through the plurality of parts, and outputting a signal representing the detected magnetic field;
An inspection apparatus for a secondary battery, comprising: frequency component extracting means for extracting a signal component having a frequency equal to the predetermined frequency from a signal representing a detected magnetic field output from the magnetic field detecting means. The inspection apparatus for a secondary battery according to claim 1,
The secondary battery inspection apparatus, wherein the direct current voltage on which the alternating current component is superimposed by the energization means is an output voltage of the secondary battery before inspection. The inspection apparatus for a secondary battery according to claim 1,
2. The secondary battery inspection apparatus according to claim 1, wherein the DC voltage applied to the secondary battery by the energization means changes within an operating voltage range of the secondary battery. The inspection apparatus for a secondary battery according to any one of claims 1 to 3, further comprising:
Comprising calculation means for calculating the distribution of the strength of the magnetic field at the position facing the plurality of portions or the distribution of the current magnitude in the plurality of portions from the signal component extracted from the frequency component extraction means. A secondary battery inspection apparatus. The inspection apparatus for a secondary battery according to claim 4, further comprising:
A judgment means for judging abnormality of the secondary battery by comparing the distribution of the intensity of the magnetic field or the distribution of the magnitude of the current calculated by the calculation means with reference information prepared in advance; Secondary battery inspection device. The inspection apparatus for a secondary battery according to claim 4, further comprising:
An inspection apparatus for a secondary battery, comprising display means for displaying a distribution of magnetic field strength or current distribution calculated by the calculation means. Applying a DC voltage, in which an alternating current component of a predetermined frequency is superimposed on a DC voltage within the operating voltage range of the secondary battery, between the electrodes of the secondary battery to pass a current through the secondary battery,
A magnetic sensor is positioned facing a plurality of parts of the secondary battery, and a magnetic field generated by a current flowing through the plurality of parts is detected,
A signal component having a frequency equal to the predetermined frequency is extracted from the signal representing the detected magnetic field,
A secondary battery inspection method, wherein a secondary battery is inspected using the extracted signal component. In the inspection method of the secondary battery according to claim 7,
The method for inspecting a secondary battery, wherein the DC voltage on which the AC component is superimposed is an output voltage of the secondary battery before the inspection. In the inspection method of the secondary battery according to claim 7,
The method for inspecting a secondary battery, wherein the DC voltage applied to the secondary battery changes within an operating voltage range of the secondary battery.

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