Measuring and Inspection Equipment

Abstract

To reduce measurement time required for measuring voltage of a measurement object.SOLUTION: An inspection device includes: N pairs of probes PR11 to PR2N connected with positive electrodes T1 and exterior members AO of N secondary cells Cell in which capacitors C1 are connected in parallel between the positive electrodes T1 and the exterior members AO; a scanner SC for selectively switching a pair of probes from the N pairs of probes; a measuring device M for measuring voltage between a pair of probes switched selectively; a control part CON; and plural resistance parts connected between the respective pairs of probes. The control part CON outputs control signals S11 to S1N to the scanner SC after a lapse of predetermined standby time in a state in which N pairs of probes are each connected with the positive electrodes T1 and the exterior members AO of the N secondary cells Cell, successively and selectively switches a pair of probes from the N pairs of probes, and allows the measuring device M to measure voltage between a pair of probes switched selectively at each selective switching.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a measurement device that measures the voltage between each pair of voltage measurement target portions in a plurality of measurement targets in which internal capacitances are equivalently connected in parallel between the pair of voltage measurement target portions, and to an inspection device that is equipped with this measurement device and inspects the quality of the test targets. [Background technology]

[0002] A secondary battery inspection method for inspecting a nonaqueous electrolyte secondary battery (hereinafter simply referred to as a "secondary battery") as this type of measurement target is disclosed in Patent Document 1. In this case, the secondary battery includes an exterior member formed by laminating at least a heat-sealable resin layer, a metal layer made of aluminum or an aluminum alloy, and a synthetic resin layer in this order into a bag-like laminate film, and heat-sealing the heat-sealable resin layers around the opening to form a heat-sealed portion, an electrode group having a positive electrode, a negative electrode, and a separator, and a nonaqueous electrolyte housed within the exterior member, and a positive electrode terminal connected to the positive electrode and a negative electrode terminal connected to the negative electrode, which are led out of the exterior member, and have an output voltage of 3.75 V to 3.90 V.

[0003] In some secondary batteries, pinholes or other defects may be present in the resin layer on the inner surface of the laminate film. In such cases, lithium ions in the electrolyte react with the aluminum or aluminum alloy in the metal layer to form a lithium-aluminum alloy. This lithium-aluminum alloy has a large volume expansion and is highly reactive with moisture. As a result, the metal layer disintegrates over time, reducing its intended barrier function against moisture and other elements, resulting in problems with the secondary battery.

[0004] Therefore, in the method for inspecting a secondary battery disclosed in Patent Document 1, the voltage between the positive electrode terminal of the secondary battery and the metal layer located in the heat-sealed portion of the exterior member is measured with a voltmeter with an input impedance (input resistance) of 1 G ohm or more, and the presence or absence of the above-mentioned defects is inspected by determining pass / fail using a voltage range of 0.2 V to 3.1 V as a determination index. In addition, when measuring the voltage between the positive electrode terminal and the metal layer of the exterior member, for example, one probe of a pair of probes is brought into contact with the positive electrode terminal, and the tip of the other probe is brought into contact with the metal layer by penetrating the synthetic resin layer located in the seal portion of the exterior member.

[0005] In this case, a nonaqueous electrolyte secondary battery, which is a laminated cell battery, has an internal capacitor equivalently connected in parallel between the positive terminal and the metal layer of the exterior member (hereinafter simply referred to as the "exterior member"). Therefore, if a voltmeter with a high input resistance of 1 GΩ or more is used to measure the voltage between the positive terminal and the exterior member, a transient response occurs according to a time constant determined by the capacitance of the internal capacitor and the resistance of the voltmeter's input resistor. This results in a long waiting time until the voltage between the positive terminal and the exterior member input to the voltmeter reaches a measurable steady-state value, resulting in a long voltage measurement time using the voltmeter. To shorten this waiting time, the applicant performs voltage measurements while equivalently connecting a time-constant-shortening resistor with a resistance somewhat smaller than the voltmeter's input resistance in parallel to the voltmeter's input. This reduces the time constant of the transient response and shortens the waiting time until the voltage reaches a measurable steady-state value.

[0006] Furthermore, if a voltage measurement method is adopted in which one probe of a pair of probes is brought into contact with the positive terminal and the other probe is brought into contact with an exterior member, and the voltmeter is turned on with both probes in contact to start voltage measurement, it will take a long time to turn the voltmeter's power on and off when measuring multiple (N) secondary batteries to be measured in succession. For this reason, the applicant has adopted a configuration in which N pairs of probes are held in a probe holder, and when voltage measurement begins, the probe holder is activated to connect the positive terminal and exterior member of each secondary battery to the corresponding probes at the same time.

[0007] In a voltage measurement method employing this configuration, the probe holder is activated at the start of voltage measurement, bringing all N pairs of probes into contact with the positive electrode terminals and exterior components of N secondary batteries. In this state, the N pairs of probes and the voltmeter form N measurement systems (hereinafter also referred to as "channels CH"). Next, as shown in Figures 5(a) and 5(b), a scanner is used to switch from the N pairs of probes to the pair of probes in channel CH1, which is used as the first measurement system, and connect them to the input of the voltmeter. At this time, as shown in Figure 5(c), the voltage input to the voltmeter (the voltage across the resistor used to shorten the time constant) rises to a peak voltage and then gradually decreases according to the time constant. Therefore, as shown in Figures 5(a) and 5(c), the system waits until this voltage reaches a steady state, and then begins voltage measurement after a waiting time TW has elapsed.

[0008] Next, after completing the voltage measurement for the first secondary battery, the pair of probes of channel CH2, which measures the voltage of the second secondary battery under measurement, is connected to the input of the voltmeter, as shown in Figures 5(a) and 5(d). At this time, as shown in Figure 5(e), the voltage input to the voltmeter (the voltage across the resistor for shortening the time constant) rises to a peak voltage and then gradually decreases according to the time constant. Therefore, as shown in Figures 5(a) and 5(e), the system waits until this voltage reaches a steady state, and begins measuring the voltage after the waiting time TW has elapsed. Similarly, the pair of probes of each channel CH is connected to the input of the voltmeter, and voltage measurement begins after the waiting time TW has elapsed. Thereafter, as shown in Figures 5(a) and 5(f), the pair of probes of channel CHN, which measures the voltage of the Nth secondary battery under measurement, is connected to the input of the voltmeter. At this time, as shown in Figure 5(g), the voltage input to the voltmeter (the voltage across the resistor for shortening the time constant) rises to a peak voltage and then gradually decreases according to the time constant. Therefore, as shown in Figures 1(a) and 1(g), the system waits until the voltage value reaches a steady state, and begins measuring the voltage after the waiting time TW has elapsed. With this voltage measurement method, the time constant of the transient response is reduced by using a resistor to shorten the time constant, thereby shortening the waiting time TW when measuring the voltage on each channel CH. [Prior art documents] [Patent documents]

[0009] [Patent Document 1] JP 2005-251685 A (pages 3-9, Figure 3) Summary of the Invention [Problem to be solved by the invention]

[0010] However, the voltage measurement method using a scanner adopted by the applicant described above also has the following problem that needs to be improved. Specifically, in this voltage measurement method, a resistor for shortening the time constant is equivalently connected to the input of the voltmeter, thereby shortening the waiting time TW when measuring on each channel CH. However, after switching to a pair of probes for each channel CH and connecting them to the input of the voltmeter, measurement must begin after waiting the waiting time TW. Therefore, voltage measurement requires at least the time calculated by multiplying the number of secondary batteries (N) to be measured by the waiting time TW. Therefore, when measuring the voltages of a large number of secondary batteries, the overall measurement time for voltage measurement is still long, and further reduction in measurement time is desired.

[0011] The present invention has been made to improve upon such problems, and its main object is to provide a measuring device that can further shorten the measurement time required to measure the voltage of the object to be measured, and an inspection device that is equipped with this measuring device and can further shorten the inspection time of the secondary battery that is the object to be inspected. [Means for solving the problem]

[0012] In order to achieve the above object, the measurement device according to claim 1 comprises a plurality of pairs of probes connected to each pair of voltage measurement target portions in a plurality of measurement targets, each pair of voltage measurement target portions having internal capacitances equivalently connected in parallel between the pair of voltage measurement target portions; a switching unit that selects and switches between a pair of probes from among the plurality of pairs of probes in accordance with a selection switching signal; a measurement unit that measures the voltage between the pair of probes selected and switched in accordance with the selection switching signal; and a control unit that outputs the selection switching signal to the switching unit, and further comprises a plurality of resistance units connected between each pair of probes, and the control unit: The plurality of pairs of probes with the resistor portions connected thereto are Each pair of voltage measurement target portions in the plurality of measurement targets Nisso Each one is connected at a time. S-so In the state, The electric charges accumulated in the internal capacitances of all the objects to be measured are simultaneously discharged through the resistors connected between the probes, andAfter a predetermined waiting time has elapsed, the selection switching signal is output to the switching unit, and each pair of probes is sequentially selected and switched from among the multiple pairs of probes without the waiting time having elapsed, and the measurement unit measures the voltage between the pair of probes selected and switched each time.

[0013] The measurement device according to claim 2 is the measurement device according to claim 1, wherein the resistance unit comprises a plurality of resistance circuits having different resistance values; Depending on the capacitance value of the internal capacitance equivalently connected in parallel between the pair of voltage measurement target portions and a switching circuit that selects and switches one of the plurality of resistance circuits.

[0014] A third aspect of the present invention provides the measuring device of the second aspect, wherein the switching circuit selects and switches one of the plurality of resistance circuits in accordance with a control signal output from the control unit.

[0015] The inspection device described in claim 4 includes a measurement device described in any one of claims 1 to 3, in which the pair of probes are connected to the positive terminal and exterior metal parts of a laminated lithium ion battery as the object of inspection, with the pair of voltage measurement object parts being the positive terminal and exterior metal parts of the laminated lithium ion battery as the object of inspection, and a judgment unit that judges the quality of the object of inspection based on the voltage between the probes measured by the measurement unit. [Effects of the Invention]

[0016] The measuring device and the inspection device equipped with this measuring device according to claim 1 are provided with a plurality of resistor units connected between each pair of probes, and the control unit, with the plurality of pairs of probes connected to each pair of voltage measurement target portions of the plurality of measurement targets, simultaneously discharges the electric charges accumulated in the internal capacitances of all the measurement targets via the resistor units connected between each probe. Then, after a waiting time has elapsed, the control unit sequentially outputs a selection switching signal to the switching unit, Without waiting time,A pair of probes is sequentially selected and switched from among multiple pairs of probes, and each time a selection is made, the voltage between the pair of probes selected and switched is measured by a measurement unit, and the quality of each measurement object (each inspection object) is determined based on the measured voltage.

[0017] Therefore, with this measuring device and this inspection device, prior to starting voltage measurement, it is only necessary to wait one waiting time after connecting multiple pairs of probes to pairs of voltage measurement target locations on multiple measurement targets; thereafter, voltage can be measured immediately without waiting for the waiting time when measuring the voltage of each measurement target. As a result, while the configuration previously adopted by the applicant required at least a waiting time multiplied by the number of measurement targets, with this measuring device and inspection device, only one waiting time is required, thereby further shortening the measurement time required to measure the voltage of many measurement targets and further shortening the inspection time. Furthermore, by increasing the number of pairs of probes, the time required to measure the voltage per measurement target and the time required to inspect per inspection target can be further shortened.

[0018] According to the measuring device and the inspection device including the measuring device according to claim 2, a plurality of resistance circuits having different resistance values, Depending on the capacitance value of the internal capacitance equivalently connected in parallel between a pair of voltage measurement target parts By configuring the resistance section to include a switching circuit that selects and switches one of multiple resistance circuits, it is possible to suitably select the shortening of the time constant and the accuracy of voltage measurement depending on the type of object to be measured, while maintaining a simple and inexpensive configuration.

[0019] Furthermore, according to the measuring device and the inspection device equipped with this measuring device described in claim 3, the switching circuit selects and switches one of the multiple resistance circuits in accordance with the control signal output from the control unit, thereby making it possible to fully automatically select and switch one of the multiple resistance circuits.

[0020] Furthermore, according to the inspection device described in claim 4, a laminated lithium ion battery is inspected, and its positive terminal and exterior member are used as a pair of voltage measurement target portions, and a pair of probes are connected to measure the voltage using a measurement unit. A judgment unit judges whether the lithium ion battery is good or bad based on the measured voltage, thereby making it possible to inspect the quality of the insulation resistance between the negative terminal and exterior member of the lithium ion battery, and ultimately the quality of the lithium ion battery, in a sufficiently short period of time. [Brief explanation of the drawings]

[0021] [Figure 1] FIG. 1 is a configuration diagram of an inspection device 1 for a secondary battery Cell. [Figure 2] This is the equivalent circuit of a secondary battery cell. [Figure 3] FIG. 10 is another structural diagram of the scanner SC having another resistor portion. [Figure 4] 10 is a timing chart of the battery voltage measurement of the secondary battery Cell by the measuring device M. [Figure 5] 1 is a timing chart for measuring the battery voltage of a secondary battery using a measuring device adopted by the applicant. DETAILED DESCRIPTION OF THE INVENTION

[0022] Hereinafter, embodiments of a measuring device and an inspection device will be described with reference to the accompanying drawings.

[0023] First, the configuration of the secondary battery to be inspected will be described with reference to the drawings. As shown in Fig. 2, the secondary battery Cell is, as an example, a non-aqueous electrolyte secondary battery that is the above-mentioned laminated cell battery, and has a positive electrode terminal T1, a negative electrode terminal T2, an electrolyte (not shown), and an exterior member AO made of aluminum, and the output voltage of the positive electrode terminal T1 and the negative electrode terminal T2 is 3.75V to 3.90V. In this case, the exterior member AO is formed by molding a laminate film in the shape of a bag or cup, in which synthetic resin layers (e.g., polyethylene) are attached to both sides of a metal layer (sealant). The electrolyte is contained within the exterior member AO.

[0024] In the figure, the internal capacitance (e.g., 10 nF) connected equivalently in parallel between the positive terminal T1 and the exterior member AO is represented as capacitor C1, the insulation resistance between the positive terminal T1 and the exterior member AO is represented as resistor R1, the internal capacitance connected equivalently in parallel between the negative terminal T2 and the exterior member AO is represented as capacitor C2, and the insulation resistance between the negative terminal T2 and the exterior member AO is represented as resistor R2. Also, in the figure, the internal configuration of the secondary battery Cell is represented as follows: battery B1 has an internal electromotive force of 1.0 V; battery B2 has an internal electromotive force of 2.9 V; battery B3 has an internal electromotive force of 1.7 V, the positive terminal of which is connected to the junction between the negative terminal of battery B1 and the positive terminal of battery B2; and resistance R3 represents the insulation resistance between the electrolyte connected in series between the negative terminal of battery B3 and the exterior member AO and the exterior member AO. In the secondary battery cell having such a configuration, when measuring the voltage between the positive terminal T1 of the secondary battery cell and the exterior member AO, the capacitor C1 is present, so that the secondary battery cell is a capacitive measurement target. In this example, N secondary batteries are sequentially inspected as inspection targets, so when distinguishing between the respective secondary batteries, the secondary batteries Cell1 to Cell N It is written as follows.

[0025] Next, a description will be given of the configuration of the inspection device 1 shown in Fig. 1. This inspection device 1 is a device for inspecting the quality of the secondary battery Cell as the inspection object described above, and has a plurality of pairs (N pairs (N is a natural number and plural)) of probes PR11, PR21, PR12, PR22, ... PR1 N ,PR2 N (Hereinafter, when not distinguishing between all probes, it will be referred to as "probe PR", and probes PR11, PR12, ..., PR1 N When there is no distinction between them, it is also called "probe PR1", and probes PR21, PR22, ... PR2 NThe inspection device 1 is configured with a probe holding unit HD that holds N pairs of probes PR and moves under the control of a control unit CON described later to connect each probe PR to the corresponding positive terminal T1 of each secondary battery cell and to an exterior member AO (exterior aluminum, which is an exterior metal part), a scanner SC as a switching unit, a measuring device M as a measuring unit, an operation unit OP, and a control unit CON as a control unit. The inspection device 1 is equipped with an N-channel measurement system and is configured to measure the voltages of N secondary battery cells connected to each channel CH1 to CHN (hereinafter also referred to as "channel CH" when not distinguished), and to inspect the quality of each secondary battery cell. The scanner SC, measuring device M, and control unit CON constitute the measurement device of the present invention.

[0026] One probe PR11 of the pair of probes PR11, PR21 constituting channel CH1 has its tip connected to the positive terminal T1 of secondary battery Cell1 (one of the pair of voltage measurement target portions) and its base end connected to the input port IN11 of scanner SC. The other probe PR21 of the pair of probes PR11, PR21 has its tip connected to the exterior member AO of secondary battery Cell1 (the other of the pair of voltage measurement target portions) and its base end connected to the input port IN21 of scanner SC. One probe PR12 of the pair of probes PR12, PR22 constituting channel CH2 has its tip connected to the positive terminal T1 of secondary battery Cell2 and its base end connected to the input port IN12 of scanner SC. The other probe PR22 of the pair of probes PR12, PR22 has its tip connected to the exterior member AO of secondary battery Cell2 and its base end connected to the input port IN22 of scanner SC. Similarly, although not shown, J (J is an integer equal to or greater than 3 and less than N) J ,PR2 J One of the probes PR1 J The tip of the battery is a secondary battery cell. JThe base end of the positive terminal T1 of the scanner SC is connected to the input IN1 J Also, a pair of probes PR1 J ,PR2 J The other probe PR2 J The tip of the battery is a secondary battery cell. J The base end of the external member AO is connected to the input portion IN2 of the scanner SC. J Also, the channel CH N A pair of probes PR1 N ,PR2 N One of the probes PR1 N The tip of the battery is a secondary battery cell. N The base end of the positive terminal T1 of the scanner SC is connected to the input IN1 N Also, a pair of probes PR1 N ,PR2 N The other probe PR2 N The tip of the battery is a secondary battery cell. N The base end of the external member AO is connected to the input portion IN2 of the scanner SC. N . As an example, the probe PR2 has a sharp tip, and when measuring a voltage, the tip penetrates the synthetic resin layer located in the seal portion of the exterior member AO, thereby contacting the metal layer. However, the configuration is not limited to this, and it is also possible to employ a configuration in which a conductive sheet (rubber) or the like is brought into contact with the end surface of the exterior member AO, and the probe PR2 is brought into contact with the conductive sheet.

[0027] The probe holding unit HD holds each probe PR (plurality of pairs of probes PR), and when voltage measurement begins, it operates (moves) in accordance with a control signal S3 (described later) output from the control unit CON to simultaneously connect each of the corresponding probes PR to the positive electrode terminals T1 and exterior members AO, which are pairs of voltage measurement target portions of all (plural) secondary battery cells to be connected. However, this is not limited to automatic control in accordance with the control signal S3 output from the control unit CON, and the positive electrode terminals T1 and exterior members AO of all secondary battery cells to be connected can also be connected to the corresponding probes PR simultaneously by manually moving the probe holding unit HD at any timing by the person making the measurement.

[0028] The scanner SC receives control signals S11 to S11, which will be described later, output from the control unit CON. N The scanner SC is configured to have a function of selecting and switching one pair of probes PR from a plurality of pairs (N pairs in this example) of probes PR in accordance with a switching control signal (hereinafter, also referred to as "control signal S1" when not distinguished), and connecting the pair of probes PR to the measuring device M. Specifically, the scanner SC has input units IN11, IN21 to IN11 to which the N pairs of probes PR are respectively connected. N ,IN2 N (Hereinafter, input section IN11~IN1 N When there is no distinction between the input sections IN1 and IN2, the input sections IN21 to IN2 N and N switches SW11 to SW1 for sequentially selecting and switching a pair of probes PR from the N pairs of probes PR. N (hereinafter, when there is no need to distinguish between them, it will also be referred to as "switch SW1"), and N resistors R211 to R21 for shortening the time constant during transient response in conjunction with the capacitor C1 of the secondary battery Cell. N (hereinafter, when there is no need to distinguish between them, they will also be referred to as "resistor R21") and N resistors R221 to R22 N (hereinafter, when there is no need to distinguish between them, they are also referred to as "resistor R22"), N switches SW2 (switching circuit) for selecting and switching one of the resistors R21 and R22, and input signals SIN1 to SIN2 selected and switched by the switch SW1, which will be described later. N(voltage between the probes PR. Hereinafter, when no distinction is made, it will also be referred to as "input signal SIN"), and switches SW11 to SW1 N Control signals S11 to S1 N Input section INS11 to INS1 N (hereinafter, when there is no need to distinguish between them, they will also be referred to as "input unit INS1"), and an input unit INS2 to which a control signal S2 is input that switches and controls the movable contacts of the N switches SW2 to the same fixed contact. Note that the resistors R21 and R22 and switch SW2 can also be provided outside the scanner SC.

[0029] Switches SW11 to SW1 N are the control signals S11 to S1 N In accordance with this, selective switching control (on / off control) is performed so that any one switch SW1 to which a high control signal S1 is output is turned on, and all other switches SW1 to which a low control signal S1 is output are turned off. In this case, an input signal SIN (which is also the voltage across resistor R21 or resistor R22 for shortening the time constant), which is the voltage between the positive terminal T1 of the corresponding secondary battery Cell and the exterior member AO, is output to the measuring device M via a pair of probes PR on the channel CH of the switch SW1 that is controlled to be on.

[0030] Resistors R21 and R22 each constitute a resistor circuit and a single resistor section connected between each pair of probes PR. By providing each resistor in each channel CH, they constitute multiple resistor sections according to the present invention. Resistors R21 and R22 are used to shorten the time constant. For example, they have resistances of 10 MOhms and 100 MOhms, respectively. Either resistor is selected by switching switch SW2. In this case, in a configuration without resistors R21 and R22, when measuring the voltage of a secondary battery Cell, the voltage across capacitor C1 of the secondary battery Cell (the voltage between the positive terminal T1 and the exterior member AO) is input as an input signal SIN to the measuring device M via scanner SC. The response waveform of the input signal SIN changes according to a time constant determined by the capacitance of capacitor C1 and the resistance of an input resistor R11 (described later) within the measuring device M. For this reason, in this configuration, when the resistance value of input resistor R11 is set to, for example, approximately 10 G ohms, the large resistance value results in a large time constant, and as a result, it takes a long time for the voltage value of input signal SIN to reach a steady-state value, i.e., it takes a long time to measure the voltage value of input signal SIN.

[0031] On the other hand, in the equivalent circuit between the positive electrode T1 of secondary battery Cell and the exterior member AO, the internal electromotive force due to the above-mentioned batteries B1, B2, and B3 and the insulation resistance due to the above-mentioned resistors R2 and R3 can be collectively represented as battery B4 and resistor R4, respectively, as shown in Figure 1. In this case, when the insulation resistance (resistance 2) between the negative electrode terminal T2 and the exterior member AO is extremely good (when the negative electrode terminal T2 and the exterior member AO are in an open state), the resistance values ​​of the above-mentioned resistors R2 and R3 are extremely large (e.g., infinite), so the voltage value of battery B4 (which is also the charging voltage value of capacitor C1) is almost 0 V. When the insulation resistance (resistance 2) between the negative electrode terminal T2 and the exterior member AO is extremely poor (when the exterior member AO is in a short-circuit state), the voltage value of battery B4 (which is also the charging voltage value of capacitor C1) is the sum of the voltage values ​​of batteries B1 and B2. Therefore, when only distinguishing between these two states (determining whether the secondary battery Cell is good or bad), it is also possible to measure the voltage between the positive electrode T1 and the exterior member AO without waiting for the standby time, and determine whether the secondary battery Cell is good or bad based on the measured value.

[0032] However, when the insulation resistance (resistance 2) between the negative terminal T2 and the exterior member AO is in an intermediate state between an open state and a short state, the voltage value of battery B4 is a voltage value corresponding to the degree of the intermediate state (whether it is close to an open state or close to a short state), and furthermore, immediately after input of input signal SIN, the response waveform of input signal SIN changes in accordance with the time constant. Therefore, if the voltage is measured immediately after input of input signal SIN, it may not be possible to accurately determine whether the secondary battery Cell is good or bad. Therefore, it is necessary to measure the voltage value of input signal SIN when it has settled from a transient state to a steady state in accordance with the time constant (when a waiting time TW, described later, has elapsed since input of input signal SIN), and compare that voltage value with a predetermined threshold voltage to determine the quality of the secondary battery Cell being measured. Therefore, to shorten this waiting time TW, separate from the input resistor R11 in the measurement device M, resistors R21 and R22 for shortening the time constant are provided at the input section of the measurement device M or externally (in this example, externally). These resistors have resistances somewhat smaller (or sufficiently smaller) than the input resistor R11 and, in combination with the capacitance value of the capacitor C1, form a small time constant. However, if the resistance values ​​of the resistors R21 and R22 are set too low, the voltage value of the input signal SIN will be reduced, slightly reducing the accuracy of the voltage measurement. Therefore, the resistance values ​​of the resistors R21 and R22 are predetermined so that these two objectives (shortening the time constant and improving the accuracy of the voltage measurement) can be optimally selected. Either resistor R21 or R22 is selected depending on the type of secondary battery cell being measured (the capacitance value of the internal capacitance equivalently connected in parallel between a pair of voltage measurement targets), etc. The length of the waiting time TW and the voltage value of the threshold voltage are predetermined depending on the type of secondary battery cell being measured, etc.

[0033] Each switch SW2 operates in accordance with an instruction signal S2 output from the control unit CON to select and switch one of the resistors R21 and R22.

[0034] The measuring device M is a voltage measuring device with an extremely high input resistance, such as a digital multimeter. Equivalently, it includes an input resistor R11 of approximately 10 GΩ, for example, and a voltmeter VM that measures the voltage to be measured, the input signal SIN (the DC voltage between the positive terminal T1 and the exterior member AO), input across the input resistor R11 via probes PR1 and PR2 and scanner SC. In this case, the voltmeter VM begins measurement when a measurement start signal Ss is output from the control unit CON. It then A / D-converts the input signal SIN using its internal A / D converter to generate measurement data Dm and output it to the control unit CON. The operating unit OP has various operating switches for selecting resistors R21 and R22 for shortening the time constant of the transient response and for instructing the control unit CON to start and stop measurement.

[0035] The control unit CON, in accordance with various switch signals output from the operation unit OP, outputs the above-mentioned control signal S3 to control the probe holding unit HD, outputs a control signal S1 (selection switching signal) to control the on / off of switch SW1, and outputs a control signal S2 to control selection switching of switch SW2. Furthermore, each time a probe PR is selected and switched, the control unit CON outputs a measurement start signal Ss to cause the measuring device M (voltmeter VM) to measure the voltage between probes PR and PR of the pair of probes PR selected and switched by switch SW1, thereby controlling the measuring device M. The control unit CON also has an internal memory comprised of a semiconductor memory, a hard disk drive, or the like, and stores measurement data Dm output from the measuring device M (voltmeter VM) in this internal memory.

[0036] The control unit CON also functions as a judgment unit, judging the quality of the secondary battery Cell based on the voltage value of the input signal SIN measured by the measurement device M (voltmeter VM). In this case, as described above, the control unit CON judges the quality of the secondary battery Cell by comparing the voltage value of the input signal SIN when the waiting time TW has elapsed since the input of the input signal SIN and the input signal SIN has settled into a steady state with the threshold voltage.

[0037] Next, a description will be given of the operation of the inspection device 1. It is assumed that all N secondary batteries Cell are placed at the inspection positions, and N pairs of probes PR are held in advance in the probe holding part HD.

[0038] First, one of resistors R21 and R22 is selected depending on the capacitance value of capacitor C1 of the secondary battery Cell to be measured and the desired voltage measurement accuracy. In this example, a 10 MΩ resistor R21 is selected, and the operation switch of the operation unit OP for selecting resistor R21 is operated. At this time, the control unit CON inputs a switch signal from the operation switch and outputs a control signal S2. As a result, the control signal S2 is output to the inside of the scanner SC via the input unit INS2, and all switches SW2 of each channel CH switch their movable contacts to the resistor R21 side. Note that, when selecting a 100 MΩ resistor R22, the operation switch of the operation unit OP for selecting resistor R22 is operated. At this time, the control unit CON inputs a switch signal from the operation switch and outputs a control signal S2. As a result, the control signal S2 is output to the inside of the scanner SC via the input unit INS2, and all switches SW2 of each channel CH switch their movable contacts to the resistor R22 side.

[0039] Next, an operation switch of the operation unit OP is operated to instruct the start of the test. At this time, as shown in Fig. 4(a), at time t0 when a switch signal of the operation switch is input, the control unit CON controls the probe holding unit HD to simultaneously connect each probe PR to the positive terminal T1 and the exterior member AO of each corresponding secondary battery Cell. At this time, as shown in Fig. 1, in all channels CH, a current I flows through a current path consisting of the positive potential terminal (upper terminal in Fig. 1) of capacitor C1 of the secondary battery Cell, the positive terminal T1, probe PR1, input unit IN1, switch SW2, resistor R21, input unit IN2, probe PR2, exterior member AO, and the negative potential terminal (lower terminal in Fig. 1) of capacitor C1, thereby discharging the charge accumulated in capacitor C1. 4(e), the voltage waveform W1 (which is also the voltage waveform of the voltage across capacitor C1) generated across resistor R21 exhibits a transient response according to a time constant (10 nF x 10 MOhms = 0.1 seconds) determined by the capacitance of capacitor C1 (10 nF in this example) and the resistance of resistor R21 (10 MOhms). Specifically, the voltage waveform W1 reaches a peak voltage value immediately after time t0, and then gradually decreases to a steady-state voltage value according to the time constant.

[0040] 4(a) and 4(b), the control unit CON waits from time t0 until a predetermined waiting time TW (predetermined waiting time), which is, for example, slightly longer than the time constant, has elapsed. At time t1, the control unit CON outputs a control signal S11 to turn on the switch SW11 of channel CH1. At this time, the voltage value of the voltage waveform W1 has decreased to a steady-state voltage value, and the input signal SIN11, which is the voltage across resistor R21, is output from the outputs OUT1 and OUT2 to the measuring device M via the switch SW11. At this time, the control unit CON outputs a measurement start signal Ss to the measuring device M (voltmeter VM) simultaneously with outputting the control signal S11. As a result, the measuring device M (voltmeter VM) A / D converts the input signal SIN11 to generate measurement data Dm (measure the voltage between the probes) and outputs the data to the control unit CON (measurement of channel CH1). Next, the control unit CON measures (calculates) the voltage value between the positive electrode T1 of the secondary battery Cell1 and the exterior member AO based on the input measurement data Dm. In this case, the voltage value measured by the control unit CON is the voltage value in a steady state, so if the insulation resistance (resistance R2) between the negative electrode terminal T2 and the exterior member AO is normal, the voltage value measured is lower than the threshold voltage. If the insulation resistance (resistance R2) is defective, the voltage value measured is higher than the threshold voltage. Therefore, the control unit CON accurately determines whether the secondary battery Cell1 is good or bad based on the measured voltage value and the threshold voltage.

[0041] Next, at time t1s, the control unit CON stops outputting the control signal S11 and the measurement start signal Ss, causing the measuring device M (voltmeter VM) to stop measuring the voltage of secondary battery Cell1 and terminate the quality inspection of secondary battery Cell1. At this time, the charge accumulated in the capacitors C1 of all secondary batteries in each channel CH has already been discharged, and the voltage waveform W1 in each channel CH has reached a steady-state voltage value. Therefore, without waiting for the waiting time TW, at time t2 immediately after time t1s, the control unit CON outputs the control signal S12 to turn on switch SW12 of channel CH2 and outputs the measurement start signal Ss to cause the measuring device M (voltmeter VM) to start measuring the voltage of secondary battery Cell2, the next measurement target. At this time, the control unit CON also measures (calculates) the voltage value of secondary battery Cell 2 based on the measurement data Dm output from the measurement device M (voltmeter VM) and performs quality determination for secondary battery Cell 2 based on the measured voltage value and threshold voltage, similar to the voltage measurement and quality determination for secondary battery Cell 1. Next, the control unit CON stops outputting the control signal S12 and measurement start signal Ss, stops voltage measurement for secondary battery Cell 2 by the measurement device M (voltmeter VM), and ends the quality determination for secondary battery Cell 2, similar to the voltage measurement and quality determination for secondary battery Cell 1.

[0042] After this, the control unit CON performs the voltage measurement and quality inspection on the secondary battery Cell 2, and the secondary battery Cell 3 to the secondary battery Cell 4. (N-1) Voltage measurement and quality determination are also performed on the control signal S1 (N-1) and stop outputting the measurement start signal Ss and measure the secondary battery Cell by the measuring device M (voltmeter VM). (N-1) Stop voltage measurement for the secondary battery Cell (N-1) Next, at time tN immediately after time t(N-1)s, the control unit CON outputs the control signal S1 N and switch SW1 on channel CHN. Nis turned on, and the measurement start signal Ss is output to start the secondary battery Cell N At this time, the control unit CON also starts measuring the voltage of the secondary batteries Cell1 to Cell (N-1) Similarly to the voltage measurement and quality judgment for the secondary battery Cell, based on the measurement data Dm output from the measurement device M (voltmeter VM), N The voltage value of the secondary battery Cell is measured (calculated) based on the measured voltage value and the threshold voltage. N After that, at time tNs, the control unit CON outputs the control signal S1 N Then, the output of the measurement start signal Ss is stopped, and voltage measurement and quality determination for all secondary battery cells is completed, thereby completing the inspection of the N secondary battery cells.

[0043] As described above, the measurement device M and the inspection device 1 are provided with a plurality of resistors R21 (and resistors R22) connected between each pair of probes PR for each channel CH. Prior to starting voltage measurement, the control unit CON connects N pairs of probes PR to the positive electrode terminals T1 and exterior members AO of N secondary battery cells, respectively, and simultaneously discharges the charge accumulated in the capacitors C1 of all secondary battery cells via the resistors R21 (or resistors R22) connected between the probes PR. Next, after a waiting time TW has elapsed, the control unit CON sequentially outputs a control signal S1 to the scanner SC to sequentially select and switch one pair of probes PR from the N pairs of probes PR. At each selection and switch, the control unit CON causes the measurement device M (voltmeter VM) to A / D convert (measure) the voltage between the selected pair of probes PR (input signal SIN), measures the voltage value of the input signal SIN based on the converted measurement data Dm, and determines the quality of each secondary battery cell based on the measurement value.

[0044] Therefore, prior to starting voltage measurement, N pairs of probes PR are connected to the positive terminals T1 and exterior members AO of N secondary battery cells, and then a single waiting time TW is all that is required. Thereafter, voltage measurements of each secondary battery cell can be performed immediately without waiting the waiting time TW. As a result, while the configuration previously adopted by the applicant required at least the waiting time TW multiplied by the value N, this measurement device M and inspection device 1 only require a single waiting time TW. Therefore, the measurement time required to measure the voltages of numerous secondary battery cells can be further reduced, and the inspection time can be further reduced. Furthermore, by increasing the number of N pairs of probes PR, the time required to measure and inspect each secondary battery cell can be further reduced.

[0045] Furthermore, by configuring the resistance section with a plurality of resistors R21, R22 having different resistance values ​​and a switch SW2 that selects one of the plurality of resistors R21, R22, the measuring device M and the inspection device 1 have a simple and inexpensive configuration, yet can suitably select the shortening of the time constant and the accuracy of voltage measurement depending on the type of object to be measured, etc.

[0046] Furthermore, by having the switch SW2 select one of the multiple resistors R21, R22 in accordance with the control signal S2 output from the control unit CON, the measuring device M and the inspection device 1 can automatically select and switch one of the resistors R21, R22.

[0047] Furthermore, with this inspection device 1, a laminated lithium ion battery is inspected, and its positive terminal T1 and outer casing member AO are used as a pair of voltage measurement target portions, to which a pair of probes PR are connected, and voltage is measured with a measurement device M (voltmeter VM).The control unit CON (determination unit) determines whether the secondary battery Cell is good or bad based on the measured measurement data Dm (voltage between the probes PR), thereby making it possible to inspect the quality of the insulation resistance (resistance R2) between the negative terminal T2 of the secondary battery Cell and the outer casing member AO, and ultimately the quality of the secondary battery Cell, in a sufficiently short time.

[0048] In this example, a dead time is provided between the timing (e.g., time t1s) when switch SW1 of one channel CH is turned off and the timing (e.g., time t2) when switch SW1 of the next channel CH is turned on to prevent two switches SW1 from being turned on simultaneously, taking into account the time it takes for switch SW1 to be completely turned off (fall time) and the time it takes for switch SW1 to be completely turned on (rise time). However, if simultaneous turning on is not a problem, it is not necessary to provide a dead time.

[0049] In addition, in this example, the control unit CON performs quality determination for a secondary battery cell every time a voltage measurement for that secondary battery cell is performed, but this is not limited to this. For example, the control unit CON may perform quality determination for all secondary battery cells collectively at the time when voltage measurements for all secondary batteries Cell1 to CellN are completed, rather than performing quality determination for each secondary battery cell every time a voltage measurement for that secondary battery cell is performed.

[0050] Furthermore, the resistor circuit (resistors R21, R22) in the present invention does not need to be configured with a single resistor element, but can be configured by connecting multiple resistor elements in parallel and / or series. In this example, a configuration is adopted in which two types of resistors R21, R22 with different resistance values ​​are switched to select one of the resistors (resistor R21 or resistor R22), but this is not limited to this. For example, a configuration in which three or more types of resistors with different resistance values ​​are provided and one or more of them are selected can be adopted, or a configuration in which only one resistor circuit with a predetermined resistance value is provided (a configuration in which one or more of resistor circuits with multiple resistance values ​​are not selected and switched).

[0051] Furthermore, although the example in which the switching circuit inside the scanner SC is configured with mechanical switches SW1 and SW2 has been described, it may also be configured with a switching circuit such as a relay or semiconductor switch.

[0052] 3, a digital potentiometer VR can be used as the resistance unit instead of resistors R21 and R22. In this configuration, by specifying a resistance value via an operation unit OP, the control unit CON outputs a control signal SVAR so that the resistance value of the digital potentiometer VR becomes the specified resistance value. Note that components shown in the same figure that are the same as those of the inspection device 1 described above are given the same reference numerals and redundant explanations will be omitted. With this configuration, it is possible to suitably select the shortening of the time constant and the accuracy of voltage measurement depending on the type of object to be measured, etc.

[0053] Furthermore, in the above example, the measurement object and the inspection object are a non-aqueous electrolyte secondary battery Cell, which is a laminated cell battery, but this is not limited to this, and other types of secondary batteries can be the measurement object and the inspection object as long as the measurement object and the inspection object are multiple measurement objects in which the internal capacitance is equivalently connected in parallel between a pair of voltage measurement target portions, and the measurement object and inspection object are not limited to secondary batteries, but various elements and circuits can also be the measurement object and the inspection object. [Explanation of symbols]

[0054] 1. Inspection equipment AO exterior materials Cell secondary battery CON Control unit C1 capacitor HD probe holder M Measuring device PR1,PR2 probes R21,R22 resistance SC Scanner SIN input signal SW1, SW2 switches S1, S2 control signal TW Waiting Time T1 positive terminal VM voltmeter VR Digital Potentiometer

Claims

1. a plurality of pairs of probes connected to each pair of voltage measurement target portions of a plurality of measurement targets, each pair having internal capacitances connected in parallel equivalently between the pair of voltage measurement target portions; a switching unit that selects and switches one pair of probes from among the plurality of pairs of probes in accordance with a selection and switching signal; a measurement unit that measures a voltage between the pair of probes that is selected and switched in accordance with the selection and switching signal; a control unit that outputs the selection switching signal to the switching unit, a plurality of resistors connected between each pair of probes; The control unit simultaneously connects the plurality of pairs of probes with the resistor units connected to each pair of voltage measurement target locations in the plurality of measurement targets, and in this state simultaneously discharges the electric charge accumulated in the internal capacitance of all of the measurement targets via the resistor units respectively connected between the probes, and after a predetermined waiting time has elapsed, outputs the selection switching signal to the switching unit to sequentially select and switch each pair of probes from the plurality of pairs of probes without the waiting time elapsed, and causes the measurement unit to measure the voltage between the pair of probes selected and switched each time.

2. 2. The measuring device according to claim 1, wherein the resistance section comprises a plurality of resistance circuits having different resistance values, and a switching circuit that selects and switches one of the plurality of resistance circuits depending on the capacitance value of the internal capacitance equivalently connected in parallel between the pair of voltage measurement target locations.

3. 3. The measuring device according to claim 2, wherein the switching circuit selects and switches one of the plurality of resistance circuits in accordance with a control signal output from the control unit.

4. 4. The measurement device according to claim 1, wherein the pair of probes are connected to a positive electrode terminal and an exterior metal portion of a laminated lithium ion battery as an object of testing, and the pair of voltage measurement target portions are the positive electrode terminal and an exterior metal portion of the laminated lithium ion battery as an object of testing; An inspection device comprising a determination unit that determines whether the inspection object is good or bad based on the voltage between the probes measured by the measurement unit.

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