JP2011039014A - Battery inspection device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a battery inspection device capable of inspecting the positional deviation of an electrode plate, even for a high-capacity stacked-type battery. <P>SOLUTION: The battery inspection device for inspecting positional deviation of an electrode plate of a battery 1, having a plurality of quadrangular electrode plates forming a layer, includes a positioning mechanism 4 for positioning the battery 1 so that the electrode plates lie along an X-ray beam 3 radiated from an X-ray tube 2; an X-ray detector 5 for detecting the X-ray beam 3 transmitted through the battery 1 and outputting it as a transmission image; and a data processing part 6 for taking and processing a first transmission image acquired by detecting an X-ray beam 3, transmitted in a direction along a surface of a first corner part of the electrode plates and tilted, with respect to the side, and a second transmission image acquired, by detecting an X-ray beam 3 transmitted in a direction along a surface of a second corner part of the electrode plates and tilted with respect to the side, detecting the positional deviation of the electrode plate and determining the quality. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a battery for inspecting misalignment between a positive electrode plate and a negative electrode plate of a stack type battery in which a positive electrode plate (positive electrode plate) and a negative electrode plate (negative electrode plate) are alternately arranged in layers in a container. It relates to an inspection device.

  In recent years, the demand for secondary batteries such as lithium ion batteries and nickel metal hydride batteries has been increasing due to the development of devices such as mobile phones and the practical use of electric vehicles.

  In particular, lithium ion polymer batteries in which the electrolytic solution is in the form of a gel are not easily leaking, are becoming popular because of high energy density and reduction in thickness. A lithium ion polymer battery has a structure in which a flat positive electrode plate and a negative electrode plate are stacked through a separator (hereinafter referred to as a stack type).

  In this lithium ion polymer battery, if the positive electrode plate protrudes from the negative electrode plate, lithium may deposit on the protruded positive electrode plate to cause a short circuit and ignite during use. Therefore, it is important for safety to keep the positions of the positive electrode plate and the negative electrode plate so as not to be displaced. This deviation is inspected by radioscopy after the container is sealed.

  As a conventional battery inspection apparatus for performing radioscopy of such a stack type battery, there is an apparatus described in Patent Document 1.

  FIG. 17 is a schematic view showing a conventional inspection method of a stack type battery by radioscopy. As shown in FIG. 17, first, radiation is emitted in the AA direction along the long side of the positive electrode plate 61 of the battery 60, and a transmission image is detected by the radiation detector 40. By performing image processing on this radiation transmission image, it is determined whether the positions of the positive electrode plate 61 and the negative electrode plate 62 are appropriate for each layer along the long side. Next, radiation is emitted in the BB direction along the short side of the positive electrode plate 61 of the battery 60. Similarly, it is determined whether the positions of the positive electrode plate 61 and the negative electrode plate 62 are appropriate for each layer along the short side.

JP 2004-22206 A

  In recent years, stack-type lithium ion polymer batteries tend to have higher capacities. By increasing the capacity, the size of the electrode plate is increased to, for example, 10 cm to 30 cm on a side, the thickness of the layer formed by a pair of the positive electrode plate and the negative electrode plate is reduced to, for example, 0.15 mm, and the number of layers is also, for example, It has increased to 50 (conventionally 5cm, 0.3mm, 10 layers).

  For this reason, when performing fluoroscopy in the direction along one side of the electrode plate as in the past, the side becomes longer and the layer is thinner, so that radiation is difficult to pass through due to the warpage of the electrode plate. There is a problem that the image becomes unclear, and the transmission images of the electrode plates are overlapped to become further unclear and cannot be inspected.

  The present invention is to solve the above-described problems, and an object of the present invention is to provide a battery inspection apparatus that can inspect the displacement of an electrode plate even in a high-capacity stack type battery.

  In order to solve the above-mentioned problem, the invention described in claim 1 is a battery inspection apparatus for inspecting a positional deviation of the electrode plate of a battery having a plurality of rectangular electrode plates forming a layer, a radiation source, and the radiation Positioning means for positioning the battery so that the electrode plate follows a radiation beam emitted from a source; a radiation detector that detects the radiation beam that has passed through the battery; A first transmission image in which a radiation beam transmitted through a corner portion along a plane and in a direction inclined with respect to the side is detected, and a second corner portion of the electrode plate is inclined along the plane and with respect to the side. And a data processing unit that captures and processes the second transmitted image obtained by detecting the radiation beam transmitted in the above-described direction, and detects the positional deviation of the electrode plate to determine whether it is good or bad.

  With this configuration, a transmission image is taken (detected and output) at each of the two corners of the electrode plate along the plane and in a direction inclined with respect to the side, so that the length of transmission of the radiation beam through the electrode plate is shortened. Transmission images can be obtained, and it is possible to reduce the difficulty of passing radiation due to the warping of the electrode plate and the blurring of the image of the electrode plate due to the warping, and from the two transmitted images taken. It is possible to determine the quality by detecting the displacement of the electrode plate under the premise of parallel displacement, and even if the electrode plate is large and thin in a high capacity stack type battery, the position of the electrode plate from the transmission image A shift can be detected.

  In order to solve the above-mentioned problem, the invention according to claim 2 is a battery inspection apparatus for inspecting misalignment of the electrode plate of a battery having a plurality of rectangular electrode plates forming a layer, a radiation source, and the radiation Positioning means for positioning the battery so that the electrode plate follows a radiation beam emitted from a source; a radiation detector that detects the radiation beam that has passed through the battery; A first transmission image and a second transmission image, each of which is obtained by detecting a radiation beam transmitted through one corner portion in two directions along the surface and inclined with respect to the side, are processed and processed. The gist of the invention is to have a data processing means for detecting misalignment and judging pass / fail.

  With this configuration, transmission images are taken at one corner of the electrode plate in two directions along the surface and inclined with respect to the sides, so that the length of transmission of the radiation beam through the electrode plate is reduced. An image can be obtained, and it is possible to reduce the difficulty of passing radiation due to the warping of the electrode plate and the blurring of the image of the electrode plate due to the warping. It is possible to judge the quality by detecting the displacement of the electrode plate under the premise of, and detect the displacement of the electrode plate from the transmission image even if the electrode plate is large and thin with a high capacity stack type battery. can do.

  In order to solve the above problem, the invention according to claim 3 is the battery inspection apparatus according to claim 2, wherein the data processing means includes the first transmission image and the second transmission image, Capturing and processing a third transmission image and a fourth transmission image, each of which detects a radiation beam transmitted through the second corner portion of the electrode plate along the plane and in two directions inclined with respect to the side; The gist is to determine the quality by detecting the displacement of the electrode plate.

  With this configuration, a transmission image is taken at each of the two corners of the electrode plate in two directions along the surface and inclined with respect to the side, so the length of transmission of the radiation beam through the electrode plate is shortened. A transmission image can be obtained, and it is possible to reduce the difficulty of passing radiation due to the warpage of the electrode plate and the blurring of the image of the electrode plate due to the warpage. The electrode plate position deviation is detected under the premise of displacement and rotation deviation, and the quality is judged. Therefore, even if the electrode plate is large and thin in a high capacity stack type battery, the electrode plate position deviation from the transmission image Can be detected.

  In order to solve the above problem, according to a fourth aspect of the present invention, in the battery inspection apparatus according to the second aspect, the data processing means includes the first transmission image and the second transmission image, and Capture and process a third transmission image of the radiation beam transmitted through the second corner of the electrode plate along the surface and in a direction inclined with respect to the side, and detect the displacement of the electrode plate The gist is to judge pass / fail.

  With this configuration, one corner of the electrode plate is photographed in each of two directions inclined along the surface and with respect to the side, and the other corner is inclined with respect to the side and along the surface. Since the transmission image is taken in one direction, it is possible to obtain a transmission image by shortening the length of transmission of the radiation beam through the electrode plate, and it is difficult for the radiation to pass due to the influence of the warp of the electrode plate. As a result, it is possible to reduce the blurring of the image of the electrode plate due to the influence, and to detect the position of the electrode plate from the three transmitted images taken under the premise of parallel shift and rotational shift, and to judge the quality. Even if the electrode plate is large and thin in a capacity type stack type battery, the displacement of the electrode plate can be detected from the transmission image.

  In order to solve the above-mentioned problem, the invention according to claim 5 is a battery inspection apparatus for inspecting misalignment of the electrode plate of a battery having a plurality of rectangular electrode plates forming a layer, and a radiation source and the radiation Positioning means for positioning the battery so that the electrode plate follows a radiation beam emitted from a source, a radiation detector for detecting the radiation beam transmitted through the battery and outputting it as a transmitted image, and 4 of the electrode plate Eight transmission images obtained by detecting the radiation beams transmitted through the two corners along the surface and in two directions inclined with respect to the sides are captured and processed to detect the positional deviation of the electrode plate. And a data processing means for judging.

  With this configuration, a transmission image is taken at each of the four corners of the electrode plate in two directions along the surface and inclined with respect to the side. Therefore, the length of transmission of the radiation beam through the electrode plate is shortened. A transmission image can be obtained, and it is possible to reduce the difficulty of passing radiation due to the warping of the electrode plate and the blurring of the image of the electrode plate due to the warping. The electrode plate position deviation is detected under the premise of misalignment, rotational misalignment, and uncertain dimensions of the electrode plate, and a pass / fail judgment is made. Therefore, even if the electrode plate is large and thin in a high-capacity stack type battery, The positional deviation of the electrode plate can be detected from the image.

  According to the present invention, the displacement of the electrode plate can be inspected even in a high capacity stack type battery.

The block diagram (plan view) of the battery inspection apparatus of 1st embodiment of this invention. FIG. 2 is a schematic diagram showing the structure of a battery 1. The flowchart of the test | inspection of 1st embodiment. The schematic diagram which shows the transmission image obtained by 1st embodiment. Explanatory drawing which calculates | requires position shift (DELTA) x and (DELTA) y in 1st embodiment. The block diagram (plan view) of the battery inspection apparatus of 2nd embodiment of this invention. The flowchart of the test | inspection of 2nd embodiment. Explanatory drawing which calculates | requires position shift (DELTA) x and (DELTA) y in 2nd embodiment. The block diagram (plan view) of the battery inspection apparatus of 3rd embodiment of this invention. The flowchart of the test | inspection of 3rd embodiment. Explanatory drawing which calculates | requires position shift (DELTA) x (i) and (DELTA) y (i) in 3rd embodiment. Explanatory drawing which calculates | requires position shift (DELTA) x (2) and (DELTA) y (2) in the modification 2 of 3rd embodiment. The block diagram (top view) of the battery test | inspection apparatus of 4th embodiment of this invention. The flowchart of the test | inspection of 4th embodiment. Explanatory drawing which calculates | requires protrusion length cx, cy of the negative electrode plate in 4th embodiment. Explanatory drawing (example) of correction | amendment when there exists a chamfering in the electrode plate in the modification 3 common to each embodiment. The schematic diagram which shows the test | inspection method by radioscopy of the conventional stack type battery.

(Configuration of the first embodiment)
FIG. 1 is a configuration diagram (plan view) of the battery inspection apparatus according to the first embodiment of the present invention.

  The battery inspection apparatus is an apparatus for inspecting the displacement of the electrode plate of the battery 1, and the battery is included in the X-ray tube 2 (radiation source) and the X-ray beam 3 (radiation beam) emitted from the X-ray tube 2. A positioning mechanism 4 for positioning 1, an X-ray detector 5 (radiation detector) for detecting the X-ray beam 3 transmitted through the battery 1 and outputting it as a transmission image (transmission data), and an electrode plate of the battery for capturing the transmission image A data processing unit 6 that detects a positional deviation and determines whether it is good or bad, and a mechanism control unit 7 that controls the positioning mechanism 4 according to a command from the data processing unit 6. As other configurations, a high voltage generator for supplying a high voltage to the X-ray tube 2, an X-ray controller for controlling the tube voltage / tube current, a battery transport mechanism for transporting the battery 1 and transferring it to the positioning mechanism 4, Although it has an excluding mechanism for excluding batteries determined to be defective, an X-ray collimator, an X-ray shielding box, and the like, they are omitted in FIG.

  As the X-ray tube 2, for example, a microfocus X-ray tube having an X-ray focal point F that is a divergence point of the X-ray beam 3 having a size of about 1 μm is used.

  The X-ray detector 5 detects X-rays with a two-dimensional resolution. For example, an X-ray II (image intensifier) that converts an X-ray image into a visible light image and the visible light image are captured. An imaging camera that outputs a transmission image as digital data, a detector control unit that controls the X-ray II and the imaging camera, and the like.

  FIG. 2 is a schematic diagram showing the structure of the battery 1. 2A is a plan view, FIG. 2B is an EE cross-sectional view, and FIG. 2C is a partially enlarged view of FIG. 2B. The stack type battery 1 is, for example, a lithium ion polymer battery, and the electrode plate is a quadrangle having a right angle as the electrode plate, the positive electrode plate 11 having the same shape of about 100 × 200 mm, and the negative electrode plate having the same shape that is several mm larger than this. 12 are alternately stacked, and the thickness of the layer formed by one set of the positive electrode plate 11 and the negative electrode plate 12 is about 0.2 mm, and about 30 layers are stacked, and the total thickness is about 6 mm.

  Although there is a thin resin separator between the positive electrode plate 11 and the negative electrode plate 12, it is omitted in the figure. The electrode plates (generic name of the positive electrode plate 11 and the negative electrode plate 12) 11 and 12 are accommodated in a case 13 made of a laminate film of aluminum and polypropylene, and the gap between the electrode plates is filled with a gel electrolyte solution 14. . A positive electrode lead 15 is connected to each positive electrode plate 11, the positive electrode leads 15 are bundled together and taken out to the outside, and a negative electrode lead 16 is similarly connected to each negative electrode plate 12 and also taken out to the outside. Yes.

  In the first embodiment, the radiation beam transmitted through the battery 1 in the direction P1 inclined along the surfaces of the electrode plates 11 and 12 and by 45 ° with respect to the sides of the first corner portion C1 of the electrode plates 11 and 12 is transmitted to the battery 1. And a radiation beam transmitted through the second corner portion C2 of the electrode plates 11 and 12 along the plane of the electrode plates 11 and 12 and in a direction P2 inclined by 45 ° with respect to the side. The second transmitted image is taken.

  Returning to FIG. 1, the positioning mechanism 4 holds the flat battery 1 with a holder 4 a along a horizontal plane (paper surface), and the surfaces of the electrode plates 11 and 12 are placed on the X-ray beam 3 (the X-ray optical axis L). Position along. The positioning mechanism 4 positions the first corner portion C1 of the electrode plate so that the X-ray beam 3 (the X-ray optical axis L) is transmitted in a direction P1 inclined along the surface and by 45 ° with respect to the side (solid line). Further, the battery 1 is rotated with the holder 4a along the horizontal plane with respect to the rotation axis RA, and the second corner portion C2 of the electrode plate is X-ray beam in the direction P2 inclined along the surface and by 45 ° with respect to the side. 3 (X-ray optical axis L) is positioned so as to pass through (dotted line).

  The mechanism control unit 7 controls the positioning mechanism 4 in response to a command from the data processing unit 6, and controls a battery transport mechanism (not shown) and a rejection mechanism that eliminates a battery determined to be defective. Transmit to the processing unit 6.

  The data processing unit 6 is, for example, a normal computer, and has a CPU, a memory, an interface, an input unit such as a keyboard and a mouse, a display unit, and the like. The data processing unit 6 executes the stored inspection program by the CPU, and transmits an instruction to the X-ray detector 5 and the mechanism unit control unit 7 to perform the inspection. When the data processing unit 6 stores the transmission image sent from the X-ray detector 5 in a memory, the CPU detects the displacement of the electrode plate and performs determination to determine whether each battery 1 is defective. Then, a reject signal for defective products is transmitted to the mechanism control unit 7 as a determination result.

(Operation of the first embodiment)
The operation in the first embodiment will be described with reference to FIGS.

The first embodiment is based on the premise of relative displacement between the plurality of electrode plates 11 and 12.
{The shape of each electrode plate is accurate (the length of the side and the angle of the corner are as designed) and the error can be ignored},
{The deviation is only parallel deviation},
It is something to detect below.

  FIG. 3 is a flowchart of the inspection according to the first embodiment. The inspection is performed by the CPU of the data processing unit 6 by an inspection program.

  In step S1, the positioning mechanism 4 positions the battery 1 so that the X-ray beam 3 is transmitted in the direction P1 in which the first corner portion C1 is inclined by 45 °, and the X-ray detector 5 takes a transmission image, and the data The processing unit 6 captures the transmission image.

  FIG. 4 is a schematic diagram showing a transmission image obtained in the first embodiment. 4A is a transmission image of the corner portion C1, and FIG. 4B is a transmission image of the corner portion C2.

  In step S2, referring to FIG. 4A, the data processing unit 6 obtains the protruding length L1 of the negative electrode plate with respect to the positive electrode plate using the transmission image of the corner portion C1 obtained in step S1. The protrusion length L1 is determined as L1 (k) for each combination number k of the adjacent positive electrode plate 11 and negative electrode plate 12 in order from the top (k = 1, 2,... K). Hereinafter, this combination number k will be referred to as a layer number k for convenience. L1 (k) is obtained by using normal image processing, for example, by performing filter processing, binarization, identification of electrode plate end portions, coordinate finding, and the like.

If the positive electrode plate protrudes from the negative electrode plate, the protrusion length L1 (k) is a negative value. Further, the protrusion length L1 (k) is obtained by converting the length of the pixel unit on the image into the actual length. The actual length L1 (k) is
Actual length = pixel unit length × one pixel size on the detection surface × FOD / FDD (1)
Is required. Here, FOD is the distance between the X-ray focal point F and the battery 1 (the corner portion thereof), and FDD is the distance between the X-ray focal point F and the X-ray detector 5 (detection surface 5a) (see FIG. 1).

  In step S3, the positioning mechanism 4 positions the battery 1 so that the X-ray beam 3 is transmitted in the direction P2 in which the second corner portion C2 is inclined by 45 °, and the X-ray detector 5 takes a transmission image, and the data The processing unit 6 captures the transmission image.

  In step S4, referring to FIG. 4B, the data processing unit 6 uses the transmission image of the corner portion C2 obtained in step S3, and in the same manner as in step S2, in order from the top, the negative electrode plate with respect to the positive electrode plate. Is calculated by the actual length (k = 1, 2,... K).

  In step S5, a loop of layer number k is entered, and steps S6 and S7 are repeated as follows with k = 1, 2,.

  In step S6, displacements Δx and Δy from the predetermined position of the positive electrode plate with respect to the negative electrode plate are obtained from L1 (k) and L2 (k) obtained in steps S2 and S4 as follows.

  FIG. 5 is an explanatory diagram for obtaining the positional deviations Δx and Δy in the first embodiment. FIG. 5 shows the positional relationship between the positive electrode plate 11 and the negative electrode plate 12 in one layer.

Referring to FIG. 5, assuming that the protruding amount of the negative electrode plate 12 when there is no deviation is cx0 and cy0 respectively in the x and y directions, L1 and L2 when there is no deviation are given by
L10 = cx0 · sin θ1 + cy0 · cos θ1 (2)
L20 = cx0 · cos θ2 + cy0 · sin θ2 (3)
Is required. Here, θ1 = 45 ° and θ2 = 45 °.

Next, the change from when there is no deviation between L1 (k) and L2 (k) is expressed as:
ΔL1 (k) = L1 (k) −L10 (4)
ΔL2 (k) = L2 (k) −L20 (5)
Ask for.

Next, from FIG. 5, simultaneous equations between ΔL1 (k), ΔL2 (k) and the positional deviations Δx, Δy of the positive electrode plate,
ΔL1 (k) = − Δx · sin θ1−Δy · cos θ1 (6)
ΔL2 (k) = Δx · cos θ2−Δy · sin θ2 (7)
Can be established. Solving these simultaneous equations,
Δx = {ΔL2 (k) · cos θ1−ΔL1 (k) · sin θ2} / cos (θ1−θ2) (8)
Δy = {− ΔL2 (k) · sin θ1−ΔL1 (k) · cos θ2} / cos (θ1−θ2) (9)
Is required.

  That is, in Step S6, the deviations Δx and Δy of the positive electrode plate in the layer k are obtained by sequentially calculating the expressions (2) to (5) and the expressions (8) and (9).

In step S7, the quality determination for each layer is performed as follows.
The allowable deviation is set to Δxlmt and Δylmt in the x and y directions, respectively.
| Δx | <Δxlmt and | Δy | <Δylmt
In this case, the layer k is a non-defective product, and in other cases, a defective product.

  If it is determined in step S8 that the loop has not been completed for all k, the process returns to step S5 to change k and repeat steps S6 and S7. If all k have been completed, the process proceeds to step S9.

  In step S9, comprehensive quality determination is performed. The overall pass / fail judgment is performed by determining that the product is non-defective only when it is determined to be non-defective in all layers k.

  Through the above inspection flow, the battery in which the protruding length of the negative electrode plate is greater than or equal to the specified value (cx0−Δxlmt) in the positive / negative direction of x and equal to or greater than the specified value (cy0−Δylmt) in the positive / negative direction of y. Only 1 is determined to be non-defective.

(Effect of the first embodiment)
According to the first embodiment, each of the two corner portions of the electrode plate is photographed in a direction inclined by 45 ° along the surface and with respect to the side, so that the radiation beam passes through the electrode plate. The transmission image can be obtained by shortening the length of the image, and it is possible to reduce the difficulty of passing radiation due to the warpage of the electrode plate and the blurring of the image of the electrode plate due to the warpage. From the image, it is possible to detect the position deviation of the electrode plate under the premise of parallel displacement, and to judge whether it is good or bad. It is possible to detect the positional deviation.

(Modification of the first embodiment)
(Modification 1)
In the first embodiment, the corner portion is photographed along the surface of the electrode plate and in a direction inclined by 45 ° with respect to the side, but it does not necessarily have to be 45 °. Referring to FIG. 5, when the inclination angles θ1 and θ2 are 45 °, the length of transmission of the X-ray beam through the electrode plate is the minimum and the best, but when the inclination angle is away from 45 °, the increase in the length is moderate. The inclination angles θ1 and θ2 may be about 45 °, and can be set in a range of about 20 ° to 70 °, for example.

(Modification 2)
In the first embodiment, transmission images are taken for two corner portions. However, transmission images are taken for three or more corner portions along a plane and inclined at 45 ° with respect to the sides. You may make it detect the position shift of an electrode plate from a transmitted image. As a result, it is possible to increase the statistical accuracy and detect misalignment. Here, as the calculation for obtaining the positional deviations Δx and Δy, for example, by changing two combinations of the corner portions, the positional deviations are obtained from each in the same manner as in the first embodiment, and the obtained positional deviations are averaged to obtain the final result This can be done by setting the relative positional deviations Δx and Δy.

(Modification 3)
Referring to FIG. 3, in the first embodiment, k loops (steps S5 to S8) are calculated for all layers. However, when it is determined that the pass / fail determination for each layer in step S7 is defective, the loop is You may make it complete | finish and move to the comprehensive determination of step S9. This is because if there is a defect in even one layer, it becomes defective in the comprehensive determination.

(Modification 4)
In the first embodiment, two corner portions are photographed in directions inclined by θ1 and θ2, respectively. However, another one corner portion is photographed in a direction inclined by θ3, and rotation deviation is detected from three transmitted images. In addition, it is possible to detect misalignment. In this case, three equations can be established with the parallel shifts Δxp and Δyp and the rotation shift α as unknowns. This equation is a little complicated, but it can be solved by a numerical analysis of the equation to determine the displacement.

  When this method is adopted, θ1, θ2, and θ3 are not 45 °, and the accuracy is improved when the transmission direction is set so as to intersect the longer side of the electrode plate at about 20 °.

(Configuration of Second Embodiment)
FIG. 6 is a configuration diagram (plan view) of the battery inspection apparatus according to the second embodiment of the present invention. The same components as those in the first embodiment are denoted by the same reference numerals, and description thereof is omitted. The positioning mechanism 4A in FIG. 6 differs only in the operation of positioning the battery 1 from the positioning mechanism 4 in FIG. 6 differs from the data processing unit 6 in FIG. 1 only in the inspection program.

  The positioning mechanism 4A holds the flat battery 1 with a holder (not shown) along a horizontal plane (paper surface) so that the surfaces of the electrode plates 11 and 12 are along the X-ray beam 3 (of the X-ray optical axis L). Position. The positioning mechanism 4A positions the battery 1 so that the X-ray beam 3 (the X-ray optical axis L) transmits through the first corner portion C1 of the electrode plate along the surface and in a direction inclined by θ1 with respect to the side. (Solid line), and the X-ray beam 3 (the X-ray optical axis of the X-ray beam 3) in a direction in which the holder is rotated along the horizontal plane with respect to the rotation axis RA and the corner portion C1 of the electrode plate is inclined by θ2 along the surface and the side. L) is positioned so as to pass through (dotted line).

(Operation of the second embodiment)
The operation in the second embodiment will be described with reference to FIGS.

In the second embodiment, the relative positional deviation between the plurality of electrode plates 11 and 12 is the same as the first embodiment,
{The shape of each electrode plate is accurate and errors can be ignored},
{The deviation is only parallel deviation},
It is something to detect below.

  FIG. 7 is a flowchart of inspection according to the second embodiment. The inspection is performed by the CPU of the data processing unit 6A by an inspection program.

  In step S11, the positioning mechanism 4A positions the battery 1 so that the X-ray beam 3 is transmitted in the direction inclined by θ1 through the first corner portion C1 of the electrode plate, and the X-ray detector 5 takes a transmission image, The data processing unit 6A captures the transmission image. The obtained transmission image is equivalent to that in FIG.

  In step S12, referring to FIG. 4A, the data processing unit 6A obtains the protruding length L1 of the negative electrode plate with respect to the positive electrode plate using the transmission image of the corner portion C1 obtained in step S11. Similar to the first embodiment, the protrusion length L1 is an actual length for each layer k, and is calculated as L1 (k) in order from the top (k = 1, 2,... K).

  In step S13, the positioning mechanism 4A positions the battery 1 so that the X-ray beam 3 is transmitted in a direction inclined by θ2 through the first corner portion C1 of the electrode plate, and the X-ray detector 5 takes a transmission image, The data processing unit 6A captures the transmission image. The obtained transmission image is equivalent to that in FIG.

  In step S14, referring to FIG. 4A, the data processing unit 6A obtains the protrusion length L2 of the negative electrode plate with respect to the positive electrode plate using the transmission image of the corner portion C1 obtained in step S13. Similar to the first embodiment, the protrusion length L2 is an actual length for each layer k, and is calculated as L2 (k) in order from the top (k = 1, 2,... K).

  In step S15, a loop of layer number k is entered, and steps S16 and S17 are repeated as follows with k = 1, 2,.

  In step S16, displacements Δx and Δy from the predetermined position of the positive electrode plate with respect to the negative electrode plate are obtained from L1 (k) and L2 (k) obtained in steps S12 and S14 as follows.

  FIG. 8 is an explanatory diagram for obtaining positional deviations Δx and Δy in the second embodiment. FIG. 8 shows the positional relationship between the positive electrode plate 11 and the negative electrode plate 12 in one layer.

Referring to FIG. 8, assuming that the protruding amount of the negative electrode plate 12 when there is no deviation is cx0 and cy0 in the x and y directions, respectively, L1 (k) and L2 (k) and the positional deviations Δx and Δy of the positive electrode plate Simultaneous equations,
L1 (k) = (cx0−Δx) · sin θ1 + (cy0−Δy) · cos θ1
……… (10)
L2 (k) = (cx0−Δx) · sin θ2 + (cy0−Δy) · cos θ2
……… (11)
Can be established. Solving these simultaneous equations,
Δx = cx0 + {L1 (k) · cos θ2−L2 (k) · cos θ1} / sin (θ2−θ1) (12)
Δy = cy0− {L1 (k) · sin θ2−L2 (k) · sin θ1} / sin (θ2−θ1) (13)
Is required.

  That is, in step S16, the deviations Δx and Δy of the positive electrode plate in the layer k are obtained by calculating the expressions (12) and (13).

In step S17, the quality determination for each layer is performed as follows.
The allowable deviation is set to Δxlmt and Δylmt in the x and y directions, respectively.
| Δx | <Δxlmt and | Δy | <Δylmt
In this case, the layer k is a non-defective product, and in other cases, a defective product.

  If it is determined in step S18 that the loop has not been completed for all k, the process returns to step S15 to change k and repeat steps S16 and S17. If all k have been completed, the process proceeds to step S19.

  In step S19, comprehensive quality determination is performed. The overall pass / fail judgment is performed by determining that the product is non-defective only when it is determined to be non-defective in all layers k.

  Through the above inspection flow, the battery in which the protruding length of the negative electrode plate is greater than or equal to the specified value (cx0−Δxlmt) in the positive / negative direction of x and equal to or greater than the specified value (cy0−Δylmt) in the positive / negative direction of y. Only 1 is determined to be non-defective.

(Effect of the second embodiment)
According to the second embodiment, since a transmission image is taken at each corner portion of the electrode plate in two directions along the surface and inclined with respect to the side, the length of the radiation beam passing through the electrode plate The transmission image can be obtained by shortening the length of the image, and it is possible to reduce the difficulty of passing radiation due to the warpage of the electrode plate and the blurring of the image of the electrode plate due to the warpage. From the image, it is possible to detect the position deviation of the electrode plate under the premise of parallel displacement, and to judge whether it is good or bad. It is possible to detect the positional deviation.

(Modification of the second embodiment)
(Modification 1)
In the second embodiment, the inclination angles θ1 and θ2 can be arbitrarily set, and the difference between θ1 and θ2 is large, that is, the closer to 90 °, Δx and Δy are obtained with high accuracy, but each of θ1 and θ2 is 0 ° or When the angle is close to 90 °, the length of transmission of the X-ray beam through the electrode plate becomes long and the transmitted image becomes unclear. Therefore, it is preferable that one of the inclination angles θ1 and θ2 is approximately 20 °, and the other is approximately 70 °.

(Modification 2)
In the second embodiment, transmission images in two directions are photographed for one corner portion, but transmission images are photographed in two directions along the surface and inclined with respect to the side for two or more corner portions. Then, the displacement of the electrode plate may be detected from these transmitted images. As a result, it is possible to increase the statistical accuracy and detect misalignment. Here, as the calculation for obtaining the positional deviations Δx and Δy, for example, by changing the corner portions, the positional deviations are obtained in the same manner as in the second embodiment, and the obtained positional deviations are averaged to obtain the final positional deviation. This can be done by setting Δx and Δy.

(Modification 3)
Referring to FIG. 7, in the second embodiment, k loops (steps S15 to S18) are calculated for all layers. However, when it is determined that the quality of each layer is bad in step S17, the loop is determined. You may make it complete | finish and move to the comprehensive determination of step S19. This is because if there is a defect in even one layer, it becomes defective in the comprehensive determination.

(Configuration of Third Embodiment)
FIG. 9 is a configuration diagram (plan view) of the battery inspection apparatus according to the third embodiment of the present invention. The same components as those in the first embodiment are denoted by the same reference numerals, and description thereof is omitted. The positioning mechanism 4B of FIG. 9 differs only in the operation of positioning the battery 1 from the positioning mechanism 4 of FIG. 9 differs from the data processing unit 6 in FIG. 1 only in the inspection program.

  The positioning mechanism 4B holds the flat battery 1 with a holder (not shown) along a horizontal plane (paper surface) so that the surfaces of the electrode plates 11 and 12 are along the X-ray beam 3 (of the X-ray optical axis L). , Positioning. The positioning mechanism 4B rotates the battery 1 together with the holder along the horizontal plane with respect to the rotation axis RA with the first corner portion C1 disposed on the rotation axis RA, and the first corner portion C1 of the electrode plate faces the surface. And the X-ray beam 3 is positioned at two positions so that the X-ray beam 3 is transmitted in each of the directions inclined by θ1 and θ2 with respect to the side (solid line), and the battery 1 is moved along the horizontal plane together with the holder. After C2 is disposed on the rotation axis RA, the battery 1 is rotated with respect to the rotation axis RA, and the X-ray beam 3 is rotated in each of the directions in which the corner portion C2 of the electrode plate is inclined along the plane and inclined by θ3 and θ4 with respect to the sides. Is positioned at two positions (dotted line) so that the light is transmitted.

(Operation of the third embodiment)
The operation of the third embodiment will be described with reference to FIGS.

The third embodiment is based on the premise of relative displacement between the plurality of electrode plates 11 and 12.
{The shape of each electrode plate is accurate and errors can be ignored},
{The displacement includes parallel displacement and rotational displacement},
It is something to detect below.

  FIG. 10 is a flowchart of the inspection according to the third embodiment. The inspection is performed by the CPU of the data processing unit 6B by an inspection program.

  In step S21, the positioning mechanism 4B positions the battery 1 so that the X-ray beam 3 is transmitted in the directions inclined by θ1 and θ2 through the first corner portion C1 of the electrode plate, and the X-ray detector 5 is A transmission image is taken, and the data processing unit 6B captures the transmission image. The obtained two transmitted images are the same as those in FIG.

  In step S22, referring to FIG. 4A, the data processing unit 6B uses the two transmission images of the corner portion C1 obtained in step S21 to set the protrusion lengths L1 and L2 of the negative electrode plate relative to the positive electrode plate, respectively. Ask. Similar to the first embodiment, the protrusion lengths L1 and L2 are real lengths for each layer k, and are calculated as L1 (k) and L2 (k) in order from the top (k = 1, 2,... K).

  In step S23, the positioning mechanism 4B positions the battery 1 so that the X-ray beam 3 is transmitted in the directions inclined by θ3 and θ4 through the second corner portion C2 of the electrode plate, and the X-ray detector 5 is A transmission image is taken, and the data processing unit 6B captures the transmission image. The obtained two transmission images are the same as those in FIG.

  In step S24, referring to FIG. 4B, the data processing unit 6B sets the projection lengths L3 and L4 of the negative electrode plate relative to the positive electrode plate using the two transmission images of the corner portion C2 obtained in step S23, respectively. Ask. Similar to the first embodiment, the protrusion lengths L3 and L4 are actual lengths for each layer k, and are calculated as L3 (k) and L4 (k) in order from the top (k = 1, 2,... K).

  In step S25, a loop of layer number k is entered, and steps S26 and S27 are repeated with k = 1, 2,.

  In step S26, from L1 (k), L2 (k), L3 (k), and L4 (k) obtained in steps S22 and S24, from the predetermined positions of the four vertices of the positive electrode plate when the negative electrode plate is used as a reference. Are calculated as follows: Δx (i), Δy (i), (i = 1, 2, 3, 4).

  FIG. 11 is an explanatory diagram for obtaining positional deviations Δx (i) and Δy (i) in the third embodiment. FIG. 11 shows the positional relationship between the positive electrode plate 11 and the negative electrode plate 12 in one layer.

Referring to FIG. 11, assuming that the protruding amount of the negative electrode plate 12 when there is no deviation is cx0 and cy0 respectively in the x and y directions, the positional deviations Δx (1) and Δy ( 1) uses L1 (k) and L2 (k), as in the second embodiment,
Δx (1) = cx0 + {L1 (k) · cos θ2−L2 (k) · cos θ1} / sin (θ2−θ1) (14)
Δy (1) = cy0− {L1 (k) · sin θ2−L2 (k) · sin θ1} / sin (θ2−θ1) (15)
Is required. Similarly, the positional deviations Δx (2) and Δy (2) of the apex B of the positive electrode plate at the corner portion C2 are expressed by the following equations using L3 (k) and L4 (k) as in the second embodiment:
Δx (2) = − cx0 + {L3 (k) · sin θ4-L4 (k) · sin θ3} / sin (θ4-θ3) (16)
Δy (2) = cy0 + {L3 (k) · cos θ4-L4 (k) · cos θ3} / sin (θ4-θ3) (17)
Is required. (In the equations (14) and (15), Δx (1), Δy (1), cx0, cy0, L1, L2, θ1, θ2 are respectively expressed as Δy (2), −Δx (2), cy0, cx0, (Expression (16) and expression (17) are obtained by replacing with L3, L4, θ3, and θ4.)

Next, assuming that the length of each side of the positive electrode plate 11 (vertices A, B, C, and D) is 2d and 2h, the parallel deviation is Δxp and Δyp, and the rotational deviation is α, refer to FIG. equation,
Δx (1) = Δxp + h · sin α−d · (1−cos α) (18)
Δy (1) = Δyp−d · sin α−h · (1−cos α) (19)
Δx (2) = Δxp + h · sin α + d · (1−cos α) (20)
Δy (2) = Δyp + d · sin α−h · (1−cos α) (21)
I can guide you. There are three unknowns of the simultaneous equations, α, Δxp, and Δyp, and the number of equations is four, which is redundant. However, if a solution with higher accuracy is selected, the solutions of α, Δxp, and Δyp are expressed as follows:
α = asin {(Δy (2) −Δy (1)) / 2d} (22)
Δxp = (Δx (2) + Δx (1)) / 2− (Δy (2) −Δy (1)) · h / 2d
……… (23)
Δyp = (Δy (2) + Δy (1)) / 2 + h · (1-cos α) (24)
Is obtained. Next, using the obtained α, Δxp, Δyp, the positional deviations Δx (3), Δy (3) of the vertex C of the positive electrode plate at the corner portion C3, and the vertex D of the positive electrode plate at the corner portion C4 The positional deviations Δx (4) and Δy (4) of FIG.
Δx (3) = Δxp−h · sin α + d · (1−cos α) (25)
Δy (3) = Δyp + d · sin α + h · (1−cos α) (26)
Δx (4) = Δxp−h · sin α−d · (1−cos α) (27)
Δy (4) = Δyp−d · sin α + h · (1−cos α) (28)
Is required.

  That is, in step S26, the positional deviation from the predetermined position of the four vertices of the positive electrode plate in the layer k is calculated by sequentially calculating the expressions (14) to (17) and the expressions (22) to (28). Δx (i), Δy (i), (i = 1, 2, 3, 4) are obtained.

In step S27, the quality determination for each layer is performed as follows. The allowable deviation is set to Δxlmt and Δylmt in the x and y directions, respectively.
(Δx (1) <Δxlmt,) and (Δy (1) <Δylmt), and
(−Δxlmt <Δx (2)), (Δy (2) <Δylmt), and
(−Δxlmt <Δx (3)) and (−Δylmt <Δy (3)), and
(Δx (4) <Δxlmt,), and (−Δylmt <Δy (4)),
In this case, the layer k is a non-defective product, and in other cases, a defective product.

  If it is determined in step S28 that the loop has not been completed for all k, the process returns to step S25 to change k and repeat steps S26 and S27. If all k have been completed, the process proceeds to step S29.

  In step S29, comprehensive quality determination is performed. The overall pass / fail judgment is performed by determining that the product is non-defective only when it is determined to be non-defective in all layers k.

  Through the above inspection flow, the battery in which the protruding length of the negative electrode plate is greater than or equal to the specified value (cx0−Δxlmt) in the positive / negative direction of x and equal to or greater than the specified value (cy0−Δylmt) in the positive / negative direction of y. Only 1 is determined to be non-defective.

(Effect of the third embodiment)
According to the third embodiment, each of the two corner portions of the electrode plate is photographed in two directions along the plane and inclined with respect to the side, so that the radiation beam passes through the electrode plate. The transmission image can be obtained by shortening the length, and it is possible to reduce the difficulty of passing radiation due to the warpage of the electrode plate and the blurring of the image of the electrode plate due to the warpage. From the transmission image, the displacement of the electrode plate is detected under the premise of parallel displacement and rotational displacement, and the quality is judged. Therefore, even if the electrode plate is large and thin with a high capacity stack type battery, It is possible to detect the displacement of the electrode plate.

  That is, according to the third embodiment, it is possible to detect the displacement of the electrode plate even when there is a rotational displacement as well as a parallel displacement of the electrode plate, for a high capacity stack type battery.

(Modification of the third embodiment)
(Modification 1)
In the third embodiment, the tilt angles θ1, θ2, θ3, and θ4 can be arbitrarily set as in the second embodiment. The difference in accuracy depending on the setting of θ1, θ2 (or θ3, θ4) is the same as that of the second embodiment. One of the inclination angles θ1, θ2 (or θ3, θ4) is approximately 20 °, and the other is approximately 70 °. Before and after.

(Modification 2)
In the third embodiment, the second corner portion C2 is photographed in two directions. However, the second corner portion C2 may be photographed only in the direction along the surface and inclined by θ3 with respect to the side. This is because without redundancy, an equation can be established with three transmitted images, and the misalignment can be solved.

  That is, in the modified example 2, the projection lengths L1 (k), L2 (k), and L3 (k) of the negative electrode plate are respectively obtained from three images obtained by photographing the corner portion C1 in the directions θ1 and θ2 and the corner portion C2 in the direction θ3. ) And L1 (k), L2 (k), and L3 (k), the positional deviations Δx (i), Δy (i), (i = 1, 2, 3, 4).

  In this case, first, the positional deviations Δx (1) and Δy (1) of the vertex A are obtained by the equations (14) and (15). Next, the positional deviations Δx (2) and Δy (2) of the vertex B are obtained.

FIG. 12 is an explanatory diagram for obtaining positional deviations Δx (2) and Δy (2) in Modification 2 of the third embodiment. FIG. 12 shows the deviation of the vertices A and B of the positive electrode plate 11 in one layer. The points before A and B are shifted are A0 and B0, respectively, and xy coordinates are taken with B0 as the origin. First, a change ΔL3 (k) of L3 (k) from the time when there is no deviation is expressed by the following equation:
ΔL3 (k) = L3 (k) − (cx0 · cos θ3 + cy0 · sin θ3)
……… (29)
Is required. Referring to FIG. 12 using ΔL3 (k), since the intersection of Line1 and Circle1 is point B (Δx (2), Δy (2)), simultaneous determination for obtaining Δx (2), Δy (2) equation,
Δy (2) = Δx (2) · cot θ3−ΔL3 (k) / sin θ3 (30)
{Δx (2) − (2d + Δx (1))} ² + {Δy (2) −Δy (1)} ² = 4d ²
......... (31)
Can be established. Solving this,
a = 1 + cot ² θ3 (32)
b = 2d + Δx (1) + cot θ3 · {ΔL3 (k) / sin θ3 + Δy (1)}
……… (33)
c = {2d + Δx (1)} ² + {ΔL3 (k) / sin θ3 + Δy (1)} ² −4d ² (34)
Δx (2) = {b−√ (b ² −a · c)} / a (35)
Δx (2) is obtained, and Δx (2) obtained by substituting the obtained Δx (2) into equation (30) is obtained.

  Note that if θ3 is larger than 45 ° and close to 90 °, Line1 and Circle1 intersect at an angle close to a right angle, so Δx (2) and Δy (2) can be obtained with high accuracy, but if it is too close to 90 ° Since the length of transmission of the X-ray beam through the electrode plate becomes long and the transmitted image becomes unclear, it is set to about 70 °, for example.

  As described above, Equation (14), Equation (15), Equation (29), Equation (32) to Equation (35), and Equation (30) are sequentially calculated to obtain Δx (1), Δy (1), Δx (2) and Δy (2) are obtained.

  Thereafter, the equations (22) to (28) are calculated in the same manner as in the third embodiment to obtain all the positional deviations Δx (i), Δy (i), (i = 1, 2, 3, 4). be able to.

  According to the second modification, the number of transmission images can be reduced by one, and the same effect as that of the third embodiment can be obtained.

(Modification 3)
In the third embodiment, two corner portions are photographed in two directions, but three or more corner portions may be photographed in two directions. Further, if two-way shooting is performed with at least one corner portion, the remaining corner portions may be one-way shooting. Redundancy occurs when the number of transmission images exceeds three, but an excess transmission image can be used to improve statistical accuracy.

(Modification 4)
Referring to FIG. 10, in the third embodiment, k loops (steps S25 to S28) are calculated for all layers. You may make it complete | finish and move to the comprehensive determination of step S29. This is because if there is a defect in even one layer, it becomes defective in the comprehensive determination.

(Configuration of the fourth embodiment)
FIG. 13 is a configuration diagram (plan view) of a battery inspection apparatus according to the fourth embodiment of the present invention. The same components as those in the first embodiment are denoted by the same reference numerals, and description thereof is omitted. The positioning mechanism 4C in FIG. 13 differs from the positioning mechanism 4 in FIG. 1 only in the operation of positioning the battery 1. Further, the data processing unit 6C in FIG. 13 differs from the data processing unit 6 in FIG. 1 only in the inspection program.

  The positioning mechanism 4C holds the flat battery 1 with a holder (not shown) along a horizontal plane (paper surface) so that the surfaces of the electrode plates 11 and 12 are along the X-ray beam 3 (of the X-ray optical axis L). Positioning is performed, and the battery 1 is translated along the horizontal plane together with the holder and rotated along the horizontal plane with respect to the rotation axis RA on the X-ray optical axis L for positioning. Specifically, the positioning mechanism 4C translates the battery 1 so that each of the four corner portions Ci (i = 1, 2, 3, 4) of the electrode plate is aligned with the rotation axis RA, and further to the rotation axis RA. The radiation beam 3 (of its X-ray optical axis L) is rotated in two directions θ1 (i) and θ2 (i) (solid line and dotted line) that are rotated with respect to each corner portion Ci along the surface and inclined with respect to the side. 8 positions so that is transparent.

(Operation of the fourth embodiment)
The operation in the fourth embodiment will be described with reference to FIGS. 14 and 15.

The fourth embodiment is based on the premise of relative displacement between the plurality of electrode plates 11 and 12.
{The shape of each electrode plate is inaccurate and the error cannot be ignored},
{The displacement includes parallel displacement and rotational displacement},
It is something to detect below.

  FIG. 14 is a flowchart of inspection according to the fourth embodiment. The inspection is performed by the CPU of the data processing unit 6C by an inspection program.

  In step S31, the loop of the corner portion Ci (i = 1, 2, 3, 4) is entered, and steps S32 to S38 are repeated with i = 1, 2, 3, 4 as follows.

  In step S32, the positioning mechanism 4C positions the battery 1 so that the X-ray beam 3 is transmitted in the directions in which the corner portion Ci of the electrode plate is inclined by θ1 (i) and θ2 (i). The device 5 captures the transmission image, and the data processing unit 6C captures the transmission image. The obtained two transmitted images are the same as those in FIG.

  In step S33, referring to FIG. 4A, the data processing unit 6C determines the protrusion lengths L1 and L2 of the negative electrode plate with respect to the positive electrode plate using the two transmission images of the corner portion Ci obtained in step S32. Ask. Similar to the first embodiment, the protrusion lengths L1 and L2 are actual lengths for each layer k, and are calculated as L1 (k) and L2 (k) in order from the top (k = 1, 2,... K).

  In step S34, a loop of layer number k is entered, and steps S35 and S36 are repeated as follows with k = 1, 2,.

  In step S35, the projection lengths cx and cy in the x and y directions of the negative electrode plate from the vertex of the positive electrode plate are obtained from L1 (k) and L2 (k) obtained in step S33 as follows.

  FIG. 15 is an explanatory diagram for obtaining the protrusion lengths cx and cy of the negative electrode plate in the fourth embodiment. FIG. 15 shows the positional relationship between the positive electrode plate 11 and the negative electrode plate 12 in one layer of the corner portion Ci.

Referring to FIG. 15, simultaneous equations,
L1 = cx · sin θ1 + cy · cos θ1 (36)
L2 = cx · sin θ 2 + cy · cos θ 2 (37)
Can lead. Solving this for cx, cy,
cx = (L1 · cos θ2−L2 · case1) / sin (θ1−θ2)
......... (38)
cy = (L1 · sin θ2−L2 · sin θ1) / sin (θ2−θ1)
……… (39)
It becomes.

  In step S35, cx and cy are obtained by calculating equations (38) and (39).

In step S36, the quality of each layer is judged. In the pass / fail judgment, the judgment criterion is clmt,
cx> clmt and cy> clmt
It is considered a non-defective product at other times and a defective product at other times.

  If it is determined in step S37 that the loop has not been completed for all k, the process returns to step S34 to change k and repeat steps S35 and S36. If all k have been completed, the process proceeds to step S38.

  In step S38, a pass / fail determination is made at the corner portion Ci. The pass / fail judgment at the corner portion Ci is performed by determining that the product is non-defective by Ci only when the non-defective product is determined by all layers k.

  If the loop has not been completed for all i in step S39, the process returns to step S31, i is changed, and steps S32 to S38 are repeated. If all i are completed, the process proceeds to step S40.

  In step S40, a comprehensive quality determination is performed. The overall pass / fail judgment is performed by determining that the product is non-defective only when it is determined to be non-defective at the full-width portion Ci.

  With the above inspection flow, only the battery 1 in which the protruding length of the negative electrode plate from the apex of the positive electrode plate in all layers of the full-angle portion is not less than the specified value clmt in the x direction and not less than the specified value clmt in the y direction. It is determined.

(Effect of the fourth embodiment)
According to the fourth embodiment, each of the four corner portions of the electrode plate is photographed in two directions along the plane and inclined with respect to the side, so that the radiation beam passes through the electrode plate. The transmission image can be obtained by shortening the length, and it is possible to reduce the difficulty of passing the radiation due to the warp of the electrode plate and the blurring of the image of the electrode plate due to the warp. From the transmission image, the electrode plate position deviation is detected under the premise of parallel deviation, rotational deviation, and electrode plate dimensional uncertainty, and the quality is judged, so the electrode plate is large and thin with a high-capacity stack type battery. Even if it exists, it becomes possible to detect the position shift of the electrode plate from the transmission image.

That is, according to the fourth embodiment, for a high-capacity stack type battery, not only the parallel displacement of the electrode plates but also the displacement of the electrode plates is detected even when there is a rotational displacement and an uncertain dimension of the electrode plates. It becomes possible.

(Modification of the fourth embodiment)
(Modification 1)
In the fourth embodiment, the tilt angles θ1 and θ2 can be arbitrarily set as in the second embodiment. The difference in accuracy depending on the setting of θ1 and θ2 is the same as in the second embodiment, and it is preferable that one of the inclination angles θ1 and θ2 is approximately 20 ° and the other is approximately 70 °.

(Modification 2)
Referring to FIG. 14, in the fourth embodiment, k loops (steps S34 to S37) are calculated for all layers. However, when it is determined that the quality of each layer is bad in step S36, the loop is determined. You may make it complete | finish and move to the quality determination in Ci of step S38, or the comprehensive determination of step S40. This is because if there is a defect in one layer, it becomes defective in the pass / fail judgment and comprehensive judgment in Ci.

  Similarly, in the fourth embodiment, the i-loop (steps S31 to S39) is calculated for the full-width portion Ci, but when the pass / fail determination at Ci in step S38 is determined to be bad, the loop is terminated. Then, the overall determination in step S40 may be performed. This is because if even one corner is defective, it is determined to be defective in the comprehensive determination.

(Modification common to the first to fourth embodiments)
Hereinafter, modifications common to the first to fourth embodiments will be described.

(Modification 1)
In each embodiment, referring to FIG. 4, a transmission image at a corner portion is photographed so that the entire layer is in the field of view. However, the image is divided into several images in a direction orthogonal to the layer and photographed. Also good. This is performed by moving one or more of the battery 1, the X-ray tube 2, and the X-ray detector 5 in the direction orthogonal to the layer and taking an image. Thereby, even when the battery 1 becomes thick, a transmission image of all layers can be obtained without reducing the enlargement ratio.

(Modification 2)
In each embodiment, the X-ray detector 5 constituted by the X-ray II and the imaging camera is used. However, any X-ray detector having a two-dimensional resolution may be used. For example, a semiconductor photosensor array and a scintillator are used. An FPD (flat panel detector) or an FPD using a semiconductor X-ray sensor array may be used. Moreover, you may use the X-ray detector etc. which were comprised with the microchannel plate and the imaging camera.

  Further, instead of the X-ray detector 5, an one-dimensional resolution X-ray detector (X-ray line sensor) 5A may be used. In this case, for example, referring to FIG. 1, the X-ray detector 5A is disposed so as to decompose and detect the spread of the X-ray beam 3 in the horizontal direction (the direction along the paper surface), and the batteries 1, X One-dimensional transmission images are taken at a plurality of points while scanning one or more of the tube 2 and the X-ray detector 5A in the vertical direction, and these are combined to obtain a two-dimensional transmission image. .

  Further, when the X-ray detector 5A having a one-dimensional resolution is used, the resolution direction is arranged in an arbitrary direction (vertical or oblique direction) substantially orthogonal to the center of the X-ray beam 3 (X-ray optical axis L). Also good. In this case, one-dimensional transmission images are photographed at a plurality of points while any one or more of the battery 1, the X-ray tube 2 and the X-ray detector 5A are scanned in a direction orthogonal to the resolution direction, and these are synthesized. A two-dimensional transmission image can be obtained.

(Modification 3)
In each embodiment, a stack type battery having a quadrangular electrode plate is inspected. However, the quadrangular electrode plate includes a chamfered (planar or curved) corner portion. Even when there is chamfering, a positional shift can be detected as in the operation of each embodiment, but an error occurs when the chamfering becomes large. In this case, if the shape of the chamfer is known, the calculation error can be corrected in consideration of the chamfer.

FIG. 16 is an explanatory view (one example) of correction when the electrode plate is chamfered in Modification 3 common to the embodiments. FIG. 16 shows the positional relationship between the positive electrode plate 11 and the negative electrode plate 12 in one layer. The chamfering is arcuate (cylindrical surface), the chamfering radius rp for the positive electrode plate and the chamfering radius rm for the negative electrode plate, the measured protrusion length L of the negative electrode plate is:
L ′ = L−rm + rp (40)
It can be corrected with. In each embodiment, the same calculation may be performed using this corrected value. However, since the calculation considers the positive electrode plate 11 and the negative electrode plate 12 as a virtual positive electrode plate 11 ′ and a negative electrode plate 12 ′ (dotted line) with the center point of the chamfered arc as a corner point, the predetermined value used for the calculation is used. The constants (cx0, cy0, d, h, clmt) must be changed accordingly. Specifically, the constants cx0, cy0, d, h, and clmt are expressions,
cx0 ′ = cx0−rm + rp (41)
cy0 ′ = cy0−rm + rp (42)
d ′ = d−rp (43)
h ′ = h−rp (44)
clmt ′ = clmt−rm + rp (45)
Use the value corrected in.

(Modification 4)
In each embodiment, a microfocus X-ray tube is used as the X-ray tube 2, but other X-ray tubes can also be used. In each embodiment, X-rays are used as radiation, but other transmissive radiation may be used.

DESCRIPTION OF SYMBOLS 1 ... Battery 2 ... X-ray tube 3 ... X-ray beam 4, 4A, 4B, 4C ... Positioning mechanism, 4a ... Holder 5 ... X-ray detector, 5a ... Detection surface 6, 6A, 6B, 6C ... Data processing part 7 ... mechanism control unit 11 ... positive electrode plate 12 ... negative electrode plate 13 ... case 14 ... gel electrolyte 15 ... positive electrode lead 16 ... negative electrode lead 40 ... radiation detector 60 ... battery 61 ... positive electrode plate 62 ... negative electrode plate

Claims (5)

A battery inspection device for inspecting displacement of the electrode plate of a battery having a plurality of rectangular electrode plates forming a layer,
A radiation source and positioning means for positioning the battery so that the electrode plate follows a radiation beam emitted from the radiation source;
A radiation detector that detects the radiation beam transmitted through the battery and outputs a radiation image;
A first transmission image in which a radiation beam transmitted through the first corner portion of the electrode plate along the surface and in a direction inclined with respect to the side is detected, and the second corner portion of the electrode plate along the surface And a data processing means for taking in and processing a second transmission image in which a radiation beam transmitted in a direction inclined with respect to the side is detected, and detecting a positional deviation of the electrode plate to determine whether it is good or bad;
A battery inspection apparatus comprising: A battery inspection device for inspecting displacement of the electrode plate of a battery having a plurality of rectangular electrode plates forming a layer,
A radiation source and positioning means for positioning the battery so that the electrode plate follows a radiation beam emitted from the radiation source;
A radiation detector that detects the radiation beam transmitted through the battery and outputs a radiation image;
Capture and process a first transmission image and a second transmission image, each of which detects a radiation beam transmitted through the first corner of the electrode plate in two directions along the plane and inclined with respect to the side. , A data processing means for detecting a positional deviation of the electrode plate and judging pass / fail,
A battery inspection apparatus comprising: The battery inspection apparatus according to claim 2,
The data processing means includes
In addition to the first transmission image and the second transmission image, a third beam in which a radiation beam transmitted through the second corner portion of the electrode plate along the surface and in two directions inclined with respect to the side is detected. A battery inspection apparatus characterized in that a transmission image and a fourth transmission image are captured and processed, and a position determination of the electrode plate is detected to determine whether it is acceptable. The battery inspection apparatus according to claim 2,
The data processing means includes
In addition to the first transmission image and the second transmission image, a third transmission image in which a radiation beam transmitted through the second corner portion of the electrode plate along the surface and in a direction inclined with respect to the side is detected. A battery inspection apparatus characterized in that it accepts and processes and determines whether the electrode plate is misaligned or not. A battery inspection device for inspecting displacement of the electrode plate of a battery having a plurality of rectangular electrode plates forming a layer,
A radiation source and positioning means for positioning the battery so that the electrode plate follows a radiation beam emitted from the radiation source;
A radiation detector that detects the radiation beam transmitted through the battery and outputs a radiation image;
Eight transmission images obtained by detecting the radiation beams respectively transmitted through the four corners of the electrode plate along the plane and in two directions inclined with respect to the sides are captured and processed, and the displacement of the electrode plate is corrected. Data processing means for detecting and judging pass / fail;
A battery inspection apparatus comprising:

Images