Lead-acid battery inspection device and lead-acid battery inspection method

Abstract

To determine a short circuit state including a sign of a short circuit.SOLUTION: A lead-acid battery inspection device 100 includes a light source device 103a that irradiates a current collecting portion 22 of a positive plate 12 included in a plate group 11 that constitutes a lead-acid battery 1 with light in a first wavelength region, a wavelength conversion sheet 102 that converts the light in the first wavelength region irradiated from the light source device 103a into light in a second wavelength region and irradiates the current collecting portion 22 with the light, a camera 104a that is sensitive to light in the second wavelength region, and a processing unit 107 that determines whether the lead-acid battery 1 is defective on the basis of the image of the current collecting portion 22 generated by the camera 104a.SELECTED DRAWING: Figure 5

Description

Technical Field

[0001] The present invention relates to a lead-acid battery inspection device and a lead-acid battery inspection method.

Background Art

[0002] Conventionally, a method for inspecting defects in lead-acid batteries has been used. Patent Document 1 below discloses a method for determining a short-circuit defect in a measurement cell by applying a voltage between a positive strap or a negative strap of a plate group in adjacent cell chambers of a lead-acid battery and measuring the resistance value.

Prior Art Document

Patent Document

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In recent years, when inspecting defects in lead-acid batteries, it has been required to determine also a sign of a short-circuit defect that may lead to a short-circuit defect in the future even if no short-circuit defect has occurred at the time of inspection.

[0005] Therefore, an object of the present invention is to provide a lead-acid battery inspection device and a lead-acid battery inspection method capable of determining a short-circuit defect state including a sign of a short-circuit defect.

Means for Solving the Problems

[0006] A lead-acid battery inspection device according to one aspect of the embodiment includes a light source that irradiates light in a first wavelength region to an ear portion of a plate included in an electrode group constituting a lead-acid battery, a wavelength conversion unit that converts the light in the first wavelength region irradiated from the light source into light in a second wavelength region and irradiates the ear portion of the plate, a camera that is sensitive to the light in the second wavelength region, and a processing unit that determines a defect of the lead-acid battery based on an image of the ear portion of the plate generated by the camera.

[0007] The lead-acid battery inspection method according to another aspect of the embodiment irradiates light in a first wavelength region on the ear portions of the electrode plates included in the electrode group constituting the lead-acid battery, converts the light in the first wavelength region into light in a second wavelength region and irradiates the ear portions of the electrode plates, and determines a defect of the lead-acid battery based on an image of the ear portions of the electrode plates obtained by imaging the light in the second wavelength region.

[0008] In the above-mentioned one aspect or the above-mentioned another aspect, an image showing the edge of the ear portion of the electrode plate can be acquired. Then, by determining a defect of the lead-acid battery using such an image, it is possible to determine a short-circuit defect state including a sign of a short-circuit defect predicted from the image shape of the ear portion of the electrode plate.

[0009] Here, in the above-mentioned one aspect, the camera may image the ear portion of the electrode plate from a direction along the surface of the electrode plate. Thereby, an image showing the edge of the ear portion across a plurality of electrode plates can be acquired, and by determining a defect of the lead-acid battery using such an image, it is possible to stably determine a short-circuit defect state including a sign of a short-circuit defect.

[0010] Further, the processing unit may divide the image into a plurality of rectangular regions straddling the ear portions of a plurality of electrode plates along the stacking direction of the plurality of electrode plates, and determine a defect of the lead-acid battery for each of the plurality of rectangular regions. In this case, even when there are variations in the positions or angles of the ear portions of the plurality of electrode plates, it is possible to prevent misjudgment of the short-circuit defect state by determining a defect of the lead-acid battery for each of the plurality of rectangular regions.

[0011] Further, the processing unit may determine a defect of the lead-acid battery using at least one of the area of the low-luminance region, the number of low-luminance regions, and the number of high-luminance regions for each of the plurality of rectangular regions. In this case, it is possible to stably determine a short-circuit defect state including a sign of a short-circuit defect.

[0012] The lead-acid battery inspection device of the present invention is "[1] a lead-acid battery inspection device comprising a light source that irradiates light in a first wavelength region onto the ear portions of the electrode plates included in the electrode group constituting the lead-acid battery, a wavelength conversion unit that converts the light in the first wavelength region irradiated from the light source into light in a second wavelength region and irradiates the ear portions of the electrode plates, a camera that is sensitive to the light in the second wavelength region, and a processing unit that determines defects in the lead-acid battery based on the image of the ear portions of the electrode plates generated by the camera."

[0013] The lead-acid battery inspection device of the present invention may be "[2] the lead-acid battery inspection device according to [1] above, wherein the camera images the ear portions of the electrode plates from a direction along the surface of the electrode plates."

[0014] The lead-acid battery inspection device of the present invention may be "[3] the lead-acid battery inspection device according to [1] or [2] above, wherein the processing unit divides the image into a plurality of rectangular regions straddling the ear portions of a plurality of electrode plates along the stacking direction of the plurality of electrode plates, and determines defects in the lead-acid battery for each of the plurality of rectangular regions."

[0015] The lead-acid battery inspection device of the present invention may be "[4] the lead-acid battery inspection device according to [3] above, wherein the processing unit determines defects in the lead-acid battery using at least one of the area of the low-luminance region, the number of low-luminance regions, and the number of high-luminance regions for each of the plurality of rectangular regions."

Advantages of the Invention

[0016] According to one aspect of the embodiment, it is possible to determine the short-circuit defect state of a lead-acid battery including a sign of a short-circuit defect.

Brief Description of the Drawings

[0017]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Embodiments for Carrying Out the Invention

[0018] Hereinafter, embodiments of a lead storage battery inspection apparatus and a lead storage battery inspection method according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings. In the description of the drawings, the same reference numerals are assigned to the same elements, and redundant descriptions are omitted. [Configuration of Lead Storage Battery]

[0019] First, a configuration example of a lead storage battery, which is an object to be inspected by the lead storage battery inspection apparatus according to an embodiment of the present invention, will be described.

[0020] FIG. 1 is a perspective view of a lead-acid battery. FIG. 2 is a view showing the internal structure of the lead-acid battery shown in FIG. 1. As shown in FIGS. 1 and 2, the lead-acid battery 1 according to this embodiment includes a battery case 2 having an open upper surface and accommodating a plurality of electrode groups (electrode groups) 11, and a lid 3 closing the opening of the battery case 2. The lid 3 is made of, for example, polypropylene, and includes a positive electrode terminal 4, a negative electrode terminal 5, and a liquid port plug 6 closing a liquid injection port provided in the lid 3.

[0021] FIG. 3 is a perspective view showing an electrode group. As shown in FIGS. 2 and 3, the electrode group 11 includes a positive electrode plate 12, a negative electrode plate 13, a bag separator 14, a positive electrode side strap 15, a negative electrode side strap 16, and a cell connection part 17 or a terminal post 18.

[0022] The positive electrode plate 12 includes a grid body 21 made of a lead alloy, a current collecting part 22 called an ear part connected to the upper part of the grid body 21, and an active material 23 filled in the grid body 21. Note that the active material 23 of the positive electrode plate 12 is also referred to as a positive electrode active material.

[0023] The grid body 21 is formed in a lattice shape in order to hold the active material 23 to be filled. As the grid body 21, for example, an expanded grid body obtained by making cuts in a lead alloy sheet and stretching the cuts to expand them, or a grid body produced by a casting method can be used. Examples of the lead alloy used for the grid body 21 produced by the casting method include a lead-calcium-tin system or a lead-antimony-arsenic system. The width of the grid body 21 can be, for example, 145 mm. The height of the grid body 21 can be, for example, 115 mm. The thickness of the grid body 21 can be, for example, 1.5 mm.

[0024] The active material 23 is composed of lead dioxide. The method for producing the active material 23 is not particularly limited, and for example, it can be produced by the following method. First, to the lead powder with an oxidation degree of 70% produced by the ball mill method, a slurry obtained by previously mixing red lead with dilute sulfuric acid and reacting them, water, and dilute sulfuric acid are added and kneaded to produce an active material paste. Subsequently, the produced active material paste is filled into the grid body 21 and aged and dried by a conventional method. Thereby, the unformed active material 23 filled in the grid body 21 is obtained.

[0025] Similar to the positive electrode plate 12, the negative electrode plate 13 includes a grid body 31 made of a lead alloy, a current collector 32 called an ear part connected to the upper part of the grid body 31, and an active material 33 filled in the grid body 31. Note that the active material 33 of the negative electrode plate 13 is also referred to as a negative electrode active material.

[0026] The grid body 31 is formed in a grid shape to hold the active material 33 to be filled. The grid body 31 may be the same as the grid body 21 of the positive electrode plate 12 or different. The width of the grid body 31 can be, for example, 145 mm. The height of the grid body 31 can be, for example, 115 mm. The thickness of the grid body 31 can be, for example, 1.3 mm.

[0027] The active material 33 is composed of porous spongy lead. The method for producing the active material 33 is not particularly limited, and for example, it can be produced by the following method. First, carbon powder, lignin powder, and barium compound powder are added as additives to the lead powder with an oxidation degree of 70% produced by the ball mill method and mixed. Subsequently, water and dilute sulfuric acid are added and kneaded to produce an active material paste. Subsequently, the produced active material paste is filled into the grid body 31 and aged and dried by a conventional method. Thereby, the unformed active material 33 filled in the grid body 31 is obtained.

[0028] As shown in FIGS. 2 and 3, the bag separator 14 has a function of separating the positive electrode plate 12 and the negative electrode plate 13. Further, the bag separator 14 has microporosity so that the electrolytic solution (dilute sulfuric acid) can pass through. The bag separator 14 is made of a microporous resin sheet. Examples of the resin used for the bag separator 14 include polyethylene.

[0029] As shown in FIG. 3, the negative electrode plate 13 is inserted into the bag separator 14. Further, as shown in FIGS. 2 and 3, in the electrode plate group 11, with the negative electrode plate 13 inserted into the bag separator 14, seven positive electrode plates 12 and eight negative electrode plates 13 are alternately laminated via the separator 14. Note that the number of the positive electrode plates 12 and the negative electrode plates 13 constituting the electrode plate group 11 may be changed as appropriate. The current collecting portions 22 of the seven positive electrode plates 12 are collectively welded to the positive electrode side strap 15, and the current collecting portions 32 of the eight negative electrode plates 13 are collectively welded to the negative electrode side strap 16. That is, the current collecting portion 22 of the positive electrode plate 12 and the current collecting portion 32 of the negative electrode plate 13 are collectively welded to the positive electrode side strap 15 and the negative electrode side strap 16 for each polarity, respectively. The cell connection portion 17 or the terminal post 18 is connected to the positive electrode side strap 15 and the negative electrode side strap 16, respectively. When the electrode plate group 11 is housed in the battery case 2, the terminal post 18 is connected to the positive electrode side strap 15 of the electrode plate group 11 disposed on the most positive electrode side and the negative electrode side strap 16 of the electrode plate group 11 disposed on the most negative electrode side, and the cell connection portion 17 is connected to the other positive electrode side straps 15 and negative electrode side straps 16. The positive electrode side strap 15 and the negative electrode side strap 16 are required to have weldability, strength, and acid resistance with the current collecting portion 22 or the current collecting portion 32. As the material of the positive electrode side strap 15 and the negative electrode side strap 16, for example, a lead-antimony alloy or a lead-tin alloy is used.

[0030] The interior of the electrolytic cell 2 is divided into six compartments by five partition walls, forming six cell chambers into which the electrode plate group 11 is inserted. The electrode plate group 11 is also called a single cell, and its electromotive force is 2V. Since automotive electrical components are driven by stepping up or down the DC voltage of 12V, six electrode plate groups 11 are connected in series to obtain 2V × 6 = 12V. Therefore, when the lead-acid battery 1 is used as an automotive electrical component, six cell chambers are required. Note that when the lead-acid battery 1 is used for other purposes, the number of cell chambers is not limited to six.

[0031] A method for manufacturing the lead-acid battery 1 having the above configuration will be described. FIG. 4 is a diagram for explaining the COS process in the manufacturing process of the lead-acid battery 1.

[0032] First, the electrode plate group 11 in which the positive electrode plates 12 and the negative electrode plates 13 are alternately stacked is immersed in a mold 41 supplied with molten lead 42 with the current collector 22 facing downward. Then, after cooling the electrode plate group 11 together with the mold 41 and taking out the electrode plate group 11 from the mold 41, an electrode plate group 11 is produced in which the positive electrode side strap 15 integrated with the cell connection part 17 is connected across a plurality of current collectors 22 (FIG. 3). At this time, by immersing the current collector 22 and the current collector 32 of the electrode plate group 11 in the mold 41 at the same time, the positive electrode side strap 15 integrated with the cell connection part 17 is connected across a plurality of current collectors 22, and an electrode plate group 11 is produced in which the negative electrode side strap 16 integrated with the cell connection part 17 is connected across a plurality of current collectors 32. The mold used at this time may be one mold shared by the positive electrode plate 12 and the negative electrode plate 13, or two molds separately used for the positive electrode plate 12 and the negative electrode plate 13. The above process is called a COS (Cast On Strap) process.

[0033] Next, the electrode plate group 11 is inserted into each cell chamber of the electrolytic cell 2. Then, the cell connection part 17 of the positive electrode side strap 15 and the cell connection part 17 of the negative electrode side strap 16 of the adjacent electrode plate groups 11 are welded by a partition wall penetration welding method through a through hole (not shown) provided in the partition wall. Note that welding the cell connection part 17 by the partition wall penetration welding method in this way is called cell connection.

[0034] Subsequently, the lid 3 is heat-sealed to the battery case 2. Thereby, the terminal post 18 connected to the positive electrode side strap 15 of the electrode plate group 11 arranged on the most positive electrode side is connected to the positive electrode terminal 4, and the terminal post 18 connected to the negative electrode side strap 16 of the electrode plate group 11 arranged on the most negative electrode side is connected to the negative electrode terminal 5.

[0035] Subsequently, each liquid plug 6 is opened, and dilute sulfuric acid, which is the electrolytic solution, is poured into each cell chamber from each liquid injection port provided in the lid 3 to perform battery case formation. The battery case formation is performed, for example, by energizing at an ambient temperature of 40°C and a current of 25 A for 20 hours. After the battery case formation, the lead storage battery 1 is obtained by adjusting the liquid level of the electrolytic solution.

[0036] Here, in the COS process in the manufacturing process of the above-described lead storage battery 1, depending on the situation during immersion, lead splashing defects of the electrode plate group 11 may occur. The lead splashing defect refers to a short-circuit defect in which molten lead adheres around a plurality of current collecting portions 22 or a plurality of current collecting portions 32 of the electrode plate group 11 and causes a short circuit between the positive electrode plate 12 and the negative electrode plate 13 by the lead after cooling. The lead storage battery inspection device according to an embodiment of the present invention is a device for determining including signs of a short-circuit defect due to lead splashing. [Configuration of Lead Storage Battery Inspection Device]

[0037] FIG. 5 is a diagram showing the configuration of the lead storage battery inspection device. The lead storage battery inspection device 100 includes an image acquisition unit 101a that acquires an image of a plurality of current collecting portions 22 of the electrode plate group 11, an image acquisition unit 101b that generates an image of a plurality of current collecting portions 32 of the electrode plate group 11, a wavelength conversion sheet (wavelength conversion unit) 102, and a processing unit 107 that determines a defect of the electrode plate group 11 using the images generated by the image acquisition units 101a and 101b.

[0038] The image acquisition unit 101a includes a light source device 103a, a camera 104a, and a filter 105a. The light source device 103a irradiates light in the first wavelength region from the opposite side of the current collector 32 to the current collector 22 of the plurality of positive electrode plates 12 along the edge 51 where the current collectors 22 and 32 of the electrode plate group 11 are provided. For example, the light source device 103a is provided near the edge 52 that intersects the edge 51 on the current collector 22 side of the electrode plate group 11 and includes an LED light source arranged in a ring shape or a rod shape. The light in the first wavelength region irradiated by the light source device 103a is not limited to light in a specific wavelength region, but is, for example, light in the blue light region and has a peak wavelength in a wavelength band ranging from 400 nm to 500 nm. The camera 104a has its optical axis set in a direction along the edge 51, images the current collectors 22 of the plurality of positive electrode plates 12 from a direction along the surfaces of the plurality of positive electrode plates 12 from the opposite side of the current collector 32, and acquires images of the current collectors 22 of the plurality of positive electrode plates 12. The camera 104a is, for example, a CMOS (Complementary Metal Oxide Semiconductor) camera or a CCD (Charge Coupled Devices) camera. The filter 105a is attached to the front surface of the lens 106a of the camera 104a and is a filter plate that blocks light in the first wavelength region and transmits at least light in the second wavelength region described later. With this filter 105a, the camera 104a is set to have no sensitivity in the first wavelength region and at least have sensitivity in the second wavelength region. Preferably, the camera 104a is set to have sensitivity only in the second wavelength region.

[0039] Similar to the image acquisition unit 101a, the image acquisition unit 101b includes a light source device 103b, a camera 104b, and a filter 105b. The light source device 103b irradiates the current collecting portions 32 of the plurality of negative electrode plates 13 with light in the first wavelength region from the side opposite to the current collecting portion 22 along the edge portion 51 where the current collecting portions 22 and 32 of the electrode plate group 11 are provided. For example, the light source device 103b is provided in the vicinity of the edge portion 53 that intersects the edge portion 51 on the current collecting portion 32 side of the electrode plate group 11. The camera 104b is set such that its optical axis is in the direction along the edge portion 51, and images the current collecting portions 32 of the plurality of negative electrode plates 13 from the direction along the surfaces of the plurality of negative electrode plates 13 from the side opposite to the current collecting portion 22, and acquires images of the current collecting portions 32 of the plurality of negative electrode plates 13. The filter 105b is a filter plate that is attached to the front surface of the lens 106b of the camera 104b, blocks light in the first wavelength region, and transmits at least light in the second wavelength region described later. By this filter 105b, the camera 104b is set to have no sensitivity to light in the first wavelength region and to have sensitivity to at least light in the second wavelength region. Preferably, the camera 104b is set to have sensitivity only to light in the second wavelength region.

[0040] The wavelength conversion sheet 102 is disposed between the light source device 103a and the camera 104a, and between the light source device 103b and the camera 104b, sandwiching the current collecting portions 22 of the plurality of positive electrode plates 12 or the current collecting portions 32 of the plurality of negative electrode plates 13, and is a plate-like member disposed substantially perpendicular to the surfaces of the positive electrode plate 12 and the negative electrode plate 13. Specifically, the wavelength conversion sheet 102 is disposed at an intermediate position between the plurality of current collecting portions 22 and the plurality of current collecting portions 32 at the edge portion 51. This wavelength conversion sheet 102 has the property of converting the light in the first wavelength region incident on both the surface on the light source device 103a side and the surface on the light source device 103b side into light in the second wavelength region while reflecting the light in the first wavelength region, and returning (irradiating) the light in the second wavelength region toward the plurality of current collecting portions 22 or the plurality of current collecting portions 32. The light in the second wavelength region converted by the wavelength conversion sheet 102 is not limited to the light in a specific wavelength region. For example, when the first wavelength region is light in the blue light region, it is light in the red light region and has a peak wavelength in the wavelength band ranging from 600 nm to 680 nm. As such a wavelength conversion sheet, for example, a known wavelength conversion sheet can be used.

[0041] The processing unit 107 is an image processing device represented by a personal computer, a tablet terminal, a server device, etc., and includes a CPU which is a processor, a RAM and a ROM which are main storage devices, an auxiliary storage device such as a hard disk device, an input device such as an input key and a mouse, an output device such as a display and a speaker, and a communication module which controls the transmission and reception of data between the cameras 104a, 104b, etc. via an external network.

[0042] Hereinafter, the functional configuration of the processing unit 107 will be described with reference to FIG. 6. The processing unit 107 includes an input unit 121, a region division unit 122, a determination unit 123, and an output unit 124 as functional components.

[0043] The input unit 121 acquires data of an image obtained by imaging the current collecting part 22 of the electrode plate group 11 from the camera 104a or the camera 104b, or data of an image obtained by imaging the current collecting part 32 of the electrode plate group 11. FIG. 7 is a diagram showing an image G1 obtained by imaging the current collecting part 22 of the electrode plate group 11. As such, on the image G1, a portion of the electrode plate group 11 including the current collecting part 22, the positive electrode side strap 15, and the cell connection part 17 appears as a low-luminance image PB with respect to the light in the second wavelength region, and a portion of the space where the electrode plate group 11 does not exist appears as a high-luminance image PW with respect to the light in the second wavelength region. For example, when the image is a black-and-white grayscale image, the pixel value of the low-luminance black image PB approaches 0, and the pixel value of the high-luminance white image PW becomes a relatively large significant value. Similarly, on the image obtained by imaging the current collecting part 32 of the electrode plate group 11 acquired by the input unit 121, a portion of the electrode plate group 11 including the current collecting part 32, the negative electrode side strap 16, and the cell connection part 17 appears as a low-luminance image, and a portion of the space where the electrode plate group 11 does not exist appears as a high-luminance image. Hereinafter, the functions of the region dividing unit 122 and the determination unit 123 for the image G1 obtained by imaging the current collecting part 22 of the electrode plate group 11 will be described. However, the region dividing unit 122 and the determination unit 123 have the same functions even when the image obtained by imaging the current collecting part 32 of the electrode plate group 11 is the target.

[0044] The region dividing unit 122 divides the image G1 into a plurality of rectangular regions straddling a plurality of current collecting parts 22 along the stacking direction of the plurality of positive electrode plates 12. That is, the region dividing unit 122 determines the position of the linear edge E1 on the current collecting part 22 side of the positive electrode side strap 15 in the low-luminance image PB and the position of the linear edge E2 on the current collecting part 22 side of the electrode plate stacking part of the electrode plate group 11 in the low-luminance image PB. Then, the region dividing unit 122 divides the space between these two determined edge positions E1 and E2 based on the positions of the two edges E1 and E2, and sets a rectangular region RA straddling the image PB of the portion of all the current collecting parts 22. The pixel size of the rectangular region RA may be defined in advance, or may be adjusted each time based on the positions of the two edges E1 and E2 and the position of the image PB of the portion of the current collecting part 22. Here, the region dividing unit 122 may convert the image G1 into a binary image using a preset threshold value, and perform the determination of the positions of the edges E1 and E2 and the setting of the rectangular region RA on the converted binary image.

[0045] The determination unit 123 determines the presence or absence of a short - circuit defect in the lead - acid battery 1 for a plurality of rectangular regions RA on the image G1 set by the region division unit 122. Specifically, the determination unit 123 determines the presence or absence of a short - circuit defect by the following first to third determination methods. Note that the determination unit 123 may determine the presence or absence of a short - circuit defect for one electrode plate group 11 using all of the first to third determination methods, or may determine the presence or absence of a short - circuit defect using at least one of the first to third determination methods. Also, similar to the region division unit 122, the determination unit 123 may determine the presence or absence of a short - circuit defect for a binarized image. The determination unit 123 executes the determination by the first determination method as follows. FIG. 8 is a diagram showing an image example that is the target of the first determination method by the determination unit 123. First, the determination unit 123 searches for a block (region) of low - luminance images for the rectangular region closest to the edge E2 among the plurality of rectangular regions RA. For example, when there are 8 positive electrode plates 12, 8 blocks B0 of low - luminance images are searched. Then, the determination unit 123 calculates the area BA of each of the searched plurality of blocks B0 on the image G1. Further, the determination unit 123 searches for a block (region) of low - luminance images for each of the plurality of rectangular regions RA, and determines the presence or absence of a short - circuit defect by comparing the area X of the searched plurality of blocks with the area BA of the plurality of blocks B0. For example, the determination unit 123 determines that there is a short - circuit defect when any one of the areas X of the plurality of blocks satisfies the following formula with respect to the area BA of any one of the blocks B0: X>BA + α where α is a parameter representing a specified value for the variation in area. This determination utilizes the property that when a lead - splashing defect occurs in the current collector 22, the block B1 of the low - luminance image corresponding to the portion of the current collector 22 becomes larger due to the adhesion of lead. The determination unit 123 repeats the determination for each of the plurality of rectangular regions RA, and when it is determined that there is a short - circuit defect in any one of the rectangular regions RA, it determines that there is a short - circuit defect for one electrode plate group 11.

[0046] The determination unit 123 executes the determination by the second determination method as follows. FIG. 9 is a diagram showing an image targeted by the second determination method by the determination unit 123. First, the determination unit 123 searches for a block (region) of a low-luminance image for the rectangular region closest to the edge E2 among the plurality of rectangular regions RA. For example, when there are 8 positive electrode plates 12, 8 blocks of low-luminance images are searched. Then, the determination unit 123 counts the number of the searched blocks. Further, the determination unit 123 searches for a block (region) of a low-luminance image for each of the plurality of rectangular regions RA, and determines the presence or absence of a short-circuit defect by comparing the number of the searched blocks with the number counted for the rectangular region RA closest to the edge E2. For example, the determination unit 123 determines that there is a short-circuit defect when the number of blocks for each of the plurality of rectangular regions RA does not match the number counted for the rectangular region RA closest to the edge E2. This determination utilizes the property that when a lead splash defect occurs in the current collector 22, a separated image is generated or integrated with the image of the adjacent current collector 22 in the low-luminance image portion B1 of the portion corresponding to the current collector 22. The determination unit 123 repeats the determination for each of the plurality of rectangular regions RA, and when it is determined that there is a short-circuit defect in any of the rectangular regions RA, it is determined that there is a short-circuit defect for one electrode plate group 11.

[0047] The determination unit 123 performs the determination by the third determination method as follows. FIG. 10 is a diagram showing an image targeted by the third determination method by the determination unit 123. First, the determination unit 123 searches for a block (region) of high-brightness images for the rectangular region closest to the edge E2 among the plurality of rectangular regions RA. For example, when there are 8 positive electrode plates 12, 9 blocks of high-brightness images are searched. Then, the determination unit 123 counts the number of the plurality of searched blocks. Further, the determination unit 123 searches for a block (region) of high-brightness images for each of the plurality of rectangular regions RA, and determines the presence or absence of a short-circuit defect by comparing the number of the plurality of searched blocks with the number counted for the rectangular region RA closest to the edge E2. For example, the determination unit 123 determines that there is a short-circuit defect when the number of blocks for each of the plurality of rectangular regions RA does not match the number counted for the rectangular region RA closest to the edge E2. This determination utilizes the property that when a lead splash defect occurs in the current collector 22, a separated image is generated or integrated with the image of the adjacent current collector 22 in the portion B1 corresponding to the defect in the current collector 22. The determination unit 123 repeats the determination for each of the plurality of rectangular regions RA, and when it is determined that there is a short-circuit defect in any of the rectangular regions RA, it determines that there is a short-circuit defect for one electrode plate group 11.

[0048] The output unit 124 outputs the determination result of the short-circuit defect for the electrode plate group 11 to be inspected to an output device. At this time, the output unit 124 may transmit the determination result to an external device via an external network.

[0049] Next, while referring to FIG. 11, the inspection processing procedure by the lead storage battery inspection apparatus 100 will be described, and the lead storage battery inspection method according to the present embodiment will be described in detail. FIG. 11 is a flowchart showing the inspection processing procedure by the lead storage battery inspection apparatus 100.

[0050] First, the electrode plate group 11 to be inspected is set in the lead-acid battery inspection device 100 (step S101). Next, by operating the light source devices 103a and 103b, the electrode plate group 11 is irradiated with light in the first wavelength region, and the light in the first wavelength region that has passed through the current collectors 22 and 32 is converted into light in the second wavelength region and returned to the current collectors 22 and 32 (step S102). Further, the cameras 104a and 104b are controlled to simultaneously capture the light in the second wavelength region that has passed through the current collector 22 of the electrode plate group 11 and the current collector 32 of the electrode plate group 11 (step S103).

[0051] Thereafter, based on the image of the current collector 22 acquired from the camera 104a and the image of the current collector 32 acquired from the camera 104b, the processing unit 107 determines whether there is a short-circuit defect in the electrode plate group 11 (step S104). Further, the processing unit 107 outputs the determination result of the short-circuit defect regarding the electrode plate group 11 (step S105).

[0052] The processes of steps S101 to S105 described above are repeatedly executed for each of the plurality of electrode plate groups 11 to be inspected (step S106). Thereby, inspections for a plurality of electrode plate groups 11 can be continuously performed.

[0053] In the lead-acid battery inspection device 100 according to the present embodiment described above, an image showing the edges of the plurality of current collectors 22 or the edges of the plurality of current collectors 32 when the light in the second wavelength region passes from behind the plurality of current collectors 22 or the plurality of current collectors 32 can be acquired. Then, by determining the defects of the lead-acid battery using such an image, it is possible to determine the short-circuit defect state including the omen of the short-circuit defect predicted from the image shape of the plurality of current collectors 22 or the plurality of current collectors 32.

[0054] Conventionally, there has also been a method of irradiating an object to be inspected with light, imaging the reflected light from the object to be inspected, and inspecting the object to be inspected. However, when inspecting the lead storage battery 1 by such a method, unevenness in luminance occurs in the image of the current collector portion 22, which may cause misrecognition of the edge of the current collector portion 22, resulting in a decrease in the determination accuracy of a short circuit defect. On the other hand, according to the determination method of the present embodiment, the image of the current collector portion 22 can be clearly recognized, and the determination accuracy of a short circuit defect can be improved.

[0055] Further, in the present embodiment, the cameras 104a and 104b image a plurality of current collector portions 22 and 32 from a direction along the surfaces of the electrode plates 12 and 13. As a result, an image that captures the edges of the current collector portions 22 and 32 across the current collector portions 22 and 32 of the plurality of electrode plates 12 and 13 can be obtained, and by determining a defect of the lead storage battery 1 using such an image, it is possible to stably determine a short circuit defect state including a sign of a short circuit defect.

[0056] Further, the processing unit 107 of the present embodiment divides the acquired image into a plurality of rectangular regions RA that span a plurality of current collector portions 22 and 32, and determines a defect of the lead storage battery 1 for each of the plurality of rectangular regions RA. In this case, even when there are variations in the positions or angles of the plurality of current collector portions 22 and 32, by determining a defect of the lead storage battery 1 for each of the plurality of rectangular regions RA, it is possible to prevent an erroneous determination of the short circuit defect state. For example, a method of dividing the acquired image into a plurality of rectangular regions along the surfaces of the plurality of current collector portions 22 and 32 can also be considered. However, in such a case, when there are variations in the positions or angles of the plurality of current collector portions 22 and 32, the image of the non-defective current collector portion 22 or 32 may or may not be included in a rectangular region, resulting in a decrease in the accuracy of defect determination for each rectangular region. According to the present embodiment, since the size and number of images of the non-defective current collector portions 22 and 32 in the rectangular region are stable, the accuracy of defect determination for each rectangular region is improved.

[0057] In addition, the processing unit 107 of the present embodiment determines the defect of the lead storage battery 1 using at least one of the area of the low-luminance region, the number of low-luminance regions, and the number of high-luminance regions for each of the plurality of rectangular regions RA. In this case, it is possible to stably determine the short-circuit defect state including the sign of the short-circuit defect.

[0058] The lead storage battery inspection apparatus and the lead storage battery inspection method according to the present disclosure are not limited to the examples of the above-described embodiments, but are indicated by the claims, and are intended to include all modifications within the meaning and scope equivalent to the claims.

Description of Reference Numerals

[0059] 1... Lead storage battery, 11... Plate group (electrode group), 12, 13... Plates, 22, 32... Current collector (ear part), 100... Lead storage battery inspection apparatus, 102... Wavelength conversion sheet (wavelength conversion unit), 103a, 103b... Light source devices, 104a, 104b... Cameras, 107... Processing unit, G1... Image, RA... Rectangular region.

Claims

1. A light source that irradiates light in a first wavelength region to the ear portion of a plate electrode included in an electrode group constituting a lead storage battery, A wavelength conversion unit that converts the light in the first wavelength region irradiated from the light source into light in a second wavelength region and irradiates the ear portion of the plate electrode, A camera that is sensitive to the light in the second wavelength region, A processing unit that determines a defect of the lead storage battery based on an image of the ear portion of the plate electrode generated by the camera, A lead storage battery inspection device comprising the above components.

2. The camera captures an image of the ear portion of the plate electrode from a direction along the surface of the plate electrode. The lead storage battery inspection device according to Claim 1.

3. The processing unit divides the image into a plurality of rectangular regions that straddle the ear portions of a plurality of the plate electrodes along the stacking direction of the plurality of the plate electrodes, and determines a defect of the lead storage battery for each of the plurality of rectangular regions. The lead storage battery inspection device according to Claim 1 or 2.

4. The processing unit determines a defect of the lead storage battery using at least one of the area of a low-luminance region, the number of low-luminance regions, and the number of high-luminance regions for each of the plurality of rectangular regions. The lead storage battery inspection device according to Claim 3.

5. Irradiate the ear portion of a plate electrode included in an electrode group constituting a lead storage battery with light in a first wavelength region, Convert the light in the first wavelength region into light in a second wavelength region and irradiate the ear portion of the plate electrode, Determine a defect of the lead storage battery based on an image of the ear portion of the plate electrode obtained by capturing an image of the light in the second wavelength region. A lead storage battery inspection method.

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