JP5559618B2 - Tab inspection method for cylindrical battery with electrode material with tabs, tab inspection device used for inspection method, and tab marking device - Google Patents

Description

  The present invention relates to a method for inspecting the quality of a tab by imaging the inside of a cylindrical battery with an electrode material with a tab with an X-ray camera, and a tab inspection device and a tab marking device used for the inspection method.

  In a manufacturing process of a cylindrical battery, for example, a lithium ion secondary battery, a laminate having a sandwich structure of a sheet-like positive electrode, a separator, and a sheet-like negative electrode is wound in a spiral shape, and an electrode material made of this spiral laminate In a battery can serving as a battery case. Prior to the interior process, one end of each tab to be a positive electrode lead terminal and a negative electrode lead terminal is attached to each end of the positive electrode and the negative electrode by welding or the like.

  In the interior process, the spiral laminated body with tabs (also referred to as “electrode material” in this specification) is inserted into the battery can, and one end of the negative electrode tab is welded to the bottom of the battery can. One end of the tab is welded to the lid that seals the battery can.

  The secondary battery product that has undergone the electrode material interior process is imaged by an X-ray camera in order to inspect whether the state of the tab (welded state, assembled state) inside the battery can is appropriate. Check the quality of the tab.

  The tab of the cylindrical battery is a strip of aluminum or copper, is thin, and has a good X-ray transmittance as compared to the material of the battery can. Therefore, the tab does not appear on the X-ray depending on the imaging position of the tab. As shown in FIG. 6, the condition that the tabs can be clearly seen in the X-ray imaging is when the tab 12 in the battery can 10 is imaged from an angle from the side, so the tab must be imaged from the side by an X-ray camera. . Incidentally, a portion indicated by reference numeral 11 is an electrode material made of a spiral laminate of a positive electrode sheet, a separator, and a negative electrode sheet. The shape of the electrode material may be a spiral shape, a cylindrical shape or a rectangular parallelepiped shape. FIG. 7 shows a case where the tab position is deviated from the right lateral angle. In this case, the tab is unclear and image processing for tab inspection is difficult. Reference numeral 1 denotes a cylindrical secondary battery.

  When X-ray imaging is performed on the tab in the battery can 10 at a lateral angle, the tab is embedded in the battery can, so when inserting the electrode material into the battery can, check the position of the tab with a CCD camera or the like. Thus, a mark serving as a tab position index is attached to the outer wall of the battery can, and alignment is performed with reference to the mark during X-ray imaging.

  However, when the electrode material is inserted into the battery can, the electrode material and thus the tab position may be displaced due to movement in the can, etc., so that the tab position and the mark position are displaced, and X-ray imaging is performed in an optimum state. May not be possible. Such a situation also causes a decrease in inspection accuracy.

  The present invention has been made in view of the above points, and its purpose is to correct the amount of displacement even if a displacement occurs between the tab position in the battery can and the mark position outside the battery can. Then, it is providing the tab inspection method which can image a tab in the optimal X-ray imaging position, and can improve tab inspection precision, and an X-ray inspection apparatus used therefor.

  Further, in place of the above-described deviation amount correction, a method and apparatus for accurately detecting the tab position inside the battery can from the outside of the battery can and applying a mark as an index of the tab position prior to the tab inspection. .

In order to achieve the above object, the present invention is basically configured as follows.
(1) One aspect relates to the invention of the method, and is an inspection step after a manufacturing step of a cylindrical battery in which an electrode material with a tab serving as an electrode lead terminal is mounted in a battery can serving as a battery case. In a tab inspection method for a cylindrical battery in which X-ray imaging is performed to check the quality of the tab inside the battery,
Prior to the inspection step, in the process of installing the electrode material in the battery can, the position of the tab is grasped, and a mark indicating the approximate tab position is attached on the outer periphery of the battery can,
When the mark comes to the position detected by the mark detection sensor, the rotation angle with respect to the mark detection position of the ideal imaged position where the tab in the cylindrical battery is X-ray imaged at the right lateral angle is the standard rotation angle α ₀ ( α ₀ is is determined in advance in advance and including zero),
After temporary positioning of the cylindrical battery in the circumferential direction at the point where this mark is detected, the cylindrical battery was X-ray imaged at an angle of 90 degrees with respect to the oblique or true lateral angle, and the image was taken. Extracting the image position of the tab from the image, and performing image processing to obtain a deviation between the actual rotation angle of the tab extraction position and the standard rotation angle with respect to the actual mark position of the detection target cylindrical battery,
In the subsequent inspection step, tab position deviation correction is performed to rotate the cylindrical battery to be inspected that is temporarily positioned by the mark in a direction to correct the deviation, and the tab of the cylindrical battery is set to a lateral angle. And X-ray imaging.

  When the cylindrical battery is X-ray imaged at an oblique camera angle prior to the tab inspection as in the present invention, as shown in the X-ray imaging diagram of FIG. 11 and the X-ray imaging schematic diagram shown in FIG. In addition, the outline of the tab 12 can be grasped from the captured image, and in particular, the edges 12a and 12b of the bent portion between the portion extending in the vertical direction of the tab 12 and the portion extending in the horizontal direction at the bottom of the battery can Even if the tab is misaligned, it can be clearly recognized in relation to the bottom contour of the battery can 10. In addition, since almost half of the perspective elliptical contour that becomes the bottom of the battery can 10 appears in the image, the elliptical contour coordinates can be converted into a perfect circle on the two-dimensional coordinates, for example, by the method shown in the embodiments described later. If the feature point of the tab (for example, the bent edge of the tab) is shown, the rotation angle of the tab extraction position with respect to the mark can be obtained.

  In addition, when the X-ray image is taken at an angle of 90 degrees with respect to the right lateral angle instead of the oblique camera angle, the bottom of the battery can can be taken in a perfect circle or a state close thereto. Since the tab outline can be extracted, the rotation angle of the tab extraction position with respect to the mark can be obtained from this image.

In the present invention, from the above points, for example, as shown in FIG. 12A, the actual rotation of the extraction position of the tab 12 with respect to the detection position M ₀ (mark position) of the mark M of the cylindrical battery (work) 1 to be inspected. from the deviation Δα = αn-α ₀ of the standard rotational angle alpha ₀ of predetermined an angular .alpha.n possible to calculate the positional deviation of the tab 12. The standard rotation angle α ₀ is an ideal coverage for X-ray imaging of the tab 12 in the cylindrical battery 10 at a lateral angle when the mark M on the outer periphery of the battery can comes to the position M ₀ detected by the mark detection sensor. of assuming an imaging position E1, which is the rotation angle of the ideal imaged position E1 relative to the mark detection position M _0.

The standard rotation angle α ₀ can be arbitrarily set by arbitrarily changing the mark detection position with respect to the ideal imaged position (the position of the tab that is X-rayed from the side).

In the example shown in FIG. 12A, when the cylindrical battery 10 is rotated in one direction and the mark M reaches an arbitrarily set mark detection position M ₀ , the tab 12 of the cylindrical battery 10 is imaged at a right angle. As an example in the case of the ideal imaged position E1 (shown in FIG. 12 at a position where the elliptical outline of the battery can bottom imaged in perspective and one end of the long diameter line P intersect), the mark detection position M ₀ Α ₀ > 0 is set with respect to the standard rotation angle α ₀ between the target position E1 and the ideal imaged position E1.

In FIG. 12A, the position of the tab 12 extracted by processing the obliquely picked-up image is set as an intermediate point 12c between the tab edges 12a and 12b, and the major axis H having the ideal imaged position E1 and the above-described edge intermediate point by obtaining the angle intersects the line l connecting the 12c · ellipse center point O, it is possible to determine the deviation Δα of the standard rotational angle alpha ₀ and the actual rotational angle .alpha.n.

In the example shown in FIG. 12B, the standard rotation angle α ₀ is α ₀ = 0, that is, the mark detection position M ₀ (in other words, the mark position M) is matched with the ideal imaged position E1. In this case, if the tab 12 is not misaligned, the tab 12 (specifically, the edge intermediate point 12c) and the position of the mark M coincide with each other. Thus, when the standard rotation angle α ₀ is set to zero and the mark M of the workpiece 1 is detected, the ideal imaged position E1 (mark detection position M ₀ ) and the extraction position 12c of the tab 12 are detected. If the actual rotation angle αn occurs between the two, the angle Δ between the major axis H and the line l connecting the edge intermediate point 12c and the ellipse center point O is obtained as in FIG. 12A. Is obtained as the displacement of the tab relative to the mark.

Therefore, if the cylindrical battery (workpiece) to be inspected temporarily positioned by the mark is rotated in the correction direction by the amount of deviation (that is, the-direction if the deviation is +, the + direction if the deviation is-), the tab Thus, the cylindrical battery tab can be X-ray imaged at a right lateral angle.
(2) The other relates to the invention of the apparatus. A cylindrical battery in which an electrode material with a tab serving as an electrode lead terminal is housed in a battery can is used as a work to be inspected, and this work is imaged by an X-ray camera. In the X-ray inspection apparatus for tab inspection for inspecting the state of the tab from the image,
A workpiece holding mechanism for holding the workpiece;
A workpiece rotation displacement imparting mechanism for rotationally displacing the workpiece held by the workpiece holding mechanism in the workpiece circumferential direction;
A mark detection sensor which is fixedly arranged at a predetermined position and detects a mark attached to the workpiece in cooperation with the workpiece rotation displacement applying mechanism;
Workpiece rotation displacement control means for stopping the rotation of the workpiece by stopping the workpiece rotation displacement applying operation by the workpiece rotation displacement applying mechanism at the position where the mark is detected;
A camera angle switching mechanism that switches between a mode in which the workpiece positioned with the mark as an index is X-ray imaged at a right camera angle and a mode in which an X-ray image is captured at a predetermined oblique camera angle;
The tab is extracted from the X-ray image captured at the oblique camera angle, and the actual rotation angle of the extraction position of the tab with respect to the mark and a preset standard rotation angle α ₀ (α ₀ includes zero). ) And an image processing means for calculating a correction amount of the positional deviation of the tab with respect to the mark,
A workpiece imaged position for rotating the workpiece via the rotational displacement imparting mechanism by an amount of correction of the tab displacement when the workpiece temporarily positioned using the mark as an index is imaged at a right camera angle. And a correcting means.
(3) The other is to detect the tab position inside the battery can accurately from the outside of the battery can prior to the inspection of the tab instead of the correction of the shift amount of the tab position in the above (1), and serve as an index of the tab position. A marking method for marking is proposed.

That is, after the manufacturing process of the cylindrical battery in which the electrode material with the tab to be the electrode lead terminal is mounted in the battery can serving as the battery case, the cylindrical battery is positioned using the mark attached to the outer periphery of the battery can as an index, In the cylindrical battery tab inspection method for inspecting the state of the tab inside the battery by X-ray imaging of the cylindrical battery at a lateral angle, the marking step for applying the mark performed in the previous step of the inspection includes the following steps: This is done. X-ray imaging of a cylindrical battery at an angle of 90 degrees with respect to an oblique angle or a lateral angle, and detecting the tab position inside the battery can by image processing of the oblique angle imaging or 90-degree angle imaging Calculating the rotation angle of the detection position of the tab with respect to the marking position predetermined in the image of
The cylindrical battery is rotated in the positive or negative direction by the rotation angle so that the tab position comes to the marking position, and the mark is attached to the outer periphery of the battery can.
(4) The other relates to an apparatus for performing the method (3), and is configured as follows.

In a marking device for applying a mark as a mark of the tab to the outside of the battery can of the work, with a cylindrical battery in which the electrode material with a tab serving as an electrode lead terminal is embedded in the battery can
A workpiece holding mechanism for holding the workpiece;
A workpiece rotation displacement imparting mechanism for rotationally displacing the workpiece held by the workpiece holding mechanism in the workpiece circumferential direction;
A mark printing mechanism disposed at a predetermined position to mark the outer periphery of the battery can of the workpiece;
A mechanism for X-ray imaging of the workpiece at an angle of 90 degrees with respect to an oblique angle or a lateral angle;
X-ray imaging of the workpiece is performed at an angle of 90 degrees with respect to the oblique angle or the lateral angle, and the tab position inside the battery can is detected by image processing of the oblique angle imaging or 90-degree angle imaging. Image processing means for calculating a rotation angle of the detection position of the tab with respect to a predetermined marking position in the image of
Rotation control means for rotating the workpiece in the positive or negative direction by the rotation angle via the rotational displacement imparting mechanism so that the tab position comes to the marking position;
Mark printing mechanism control means for driving the mark printing mechanism to mark the outer periphery of the battery can when the tab position comes to the marking position.

  According to the present invention, even if a positional deviation occurs between the tab position in the battery can and the mark position outside the battery can, the deviation is corrected and the tab is imaged at the optimum X-ray imaging position. The tab inspection accuracy can be increased.

The schematic diagram which shows one Example of the X-ray inspection apparatus used for the tab test | inspection of the cylindrical battery of this invention. Explanatory drawing which shows the progress outline | summary which concerns on the Example of the process of the tab inspection method of this invention. Explanatory drawing which shows the cooperation relationship between the work process in the X-ray inspection apparatus of FIG. 1, its pre-process, and a post process. The figure which shows the flowchart of the tab position shift correction | amendment and tab inspection method which concern on one Example of this invention. The figure which shows the flowchart of the correction | amendment between apparatuses performed prior to the tab position shift correction and tab inspection which concern on one Example of this invention. FIG. 3 is a schematic diagram for taking an X-ray image of a cylindrical battery (work) at a right lateral angle during inspection. The schematic diagram which carries out X-ray imaging of the workpiece | work at a slanting angle in the process before a test | inspection of a cylindrical battery (work). The figure which shows an example at the time of carrying out X-ray imaging of the tab in the battery can of a cylindrical battery from the angle | corner right beside. The X-ray imaging figure when the tab position in the battery can of a cylindrical battery has shifted | deviated from the right lateral angle. The schematic diagram which shows the deviation | shift amount of the tab position when the cylindrical battery to be examined is positioned based on the mark and X-ray imaging is performed at an oblique angle. Explanatory drawing which shows one process of the process for calculating the positional offset amount between the tab position of a cylindrical battery (work), and a mark. Explanatory drawing which shows one process of the process for calculating the positional offset amount between the tab position of a cylindrical battery (work), and a mark. Explanatory drawing which shows one process of the process for calculating the positional offset amount between the tab position of a cylindrical battery (work), and a mark. Explanatory drawing which shows one process of the process for calculating the positional offset amount between the tab position of a cylindrical battery (work), and a mark. Explanatory drawing which shows the positional relationship (deviation amount) between the tab extraction position in a battery when a X-ray image of a cylindrical battery (work) is taken at an oblique angle and a mark. Explanatory drawing which shows the 1st example for calculating the positional offset amount between the tab position of a cylindrical battery (work), and a mark. Explanatory drawing which shows the 2nd example for calculating the positional offset amount between the tab position of a cylindrical battery (work), and a mark. Explanatory drawing which shows the 3rd example for calculating the positional offset amount between the tab position of a cylindrical battery (work), and a mark. Explanatory drawing which shows the 4th example for calculating the positional offset amount between the tab position of a cylindrical battery (work), and a mark. Explanatory drawing which shows the 5th example for calculating the positional offset amount between the tab position of a cylindrical battery (work), and a mark. Explanatory drawing which shows the 6th example for calculating the positional offset amount between the tab position of a cylindrical battery (work), and a mark. Explanatory drawing which shows the 7th example for calculating the positional offset amount between the tab position of a cylindrical battery (work), and a mark. Explanatory drawing which shows the 8th example for calculating the positional offset amount between the tab position of a cylindrical battery (work), and a mark. The figure which shows an example of the image which X-rayed the cylindrical battery (work | work) at the diagonal angle. The principle figure which shows an example of how to obtain | require the tab position shift with respect to the mark detection of a cylindrical battery (work). The principle figure which shows the other example of how to obtain | require the position shift of the tab with respect to the mark detection of a cylindrical battery (work). 10F and 10G are supplementary explanatory diagrams. The schematic diagram which shows the Example of the marking apparatus used for the tab test | inspection of the cylindrical battery of this invention. The principle figure which shows the Example which prints a mark on a cylindrical battery (work) using the marking apparatus of FIG.

  First, an outline of an X-ray inspection apparatus for tab inspection of a cylindrical battery according to an embodiment of the present invention will be described with reference to FIGS.

  1 and 3, a cylindrical battery (hereinafter also referred to as “work”) 1 to be inspected has an electrode material with a tab inside as described above. In the present embodiment, the cylindrical lithium ion secondary battery described above as an example of the workpiece 1 is illustrated, but the present invention is not limited to this, and the battery with a tab-like electrode material similar to the lithium ion secondary battery is incorporated in the battery can. Any secondary battery can be used.

  The X-ray imaging apparatus includes an X-ray irradiation apparatus, that is, an X-ray source 7 and an II (image intensifier) type camera 6 that captures X-rays, and a workpiece 1 is placed between the X-ray source 7 and the camera 6. It is set via the holding mechanism 3. The workpiece holding mechanism 3 is a mechanism that supports the workpiece 1, and the workpiece 1 is placed on the V-order cut surface 3 a on the upper surface thereof so as to be rotatable around the axis in the battery can circumferential direction.

  A work rotation displacement imparting mechanism 4 that rotates and displaces the work 1 held by the work holding mechanism 3 in the work circumferential direction is disposed beside the X-ray imaging position. The workpiece rotation displacement imparting mechanism 4 includes a servo motor (for example, a stepping motor) 40 and a rotational torque imparting roller (for example, a rubber roller) 41 having a large friction coefficient mounted on the output shaft thereof.

  The work holding mechanism 3 can move up and down via an elevating mechanism (not shown), and is pressed against the rotational torque applying roller 41 by moving upward. When the rotation of the motor 40 is controlled in this state, the workpiece 1 receives rotational force from the roller 41 and is rotationally displaced in the workpiece circumferential direction (battery can circumferential direction). While the motor 40 is stopped, the work 1 is held between the roller 41 and the work holding mechanism 3 and held at the current position. The elevating mechanism may be provided on the work rotation displacement applying mechanism 4 side instead of the work holding mechanism 3, and the mechanism 41 may be lowered to press the roller 41 against the work 1. Although three workpiece holding mechanisms 3 in FIG. 3 are illustrated, one is actually used for convenience of drawing, that is, a holding mechanism in a state of receiving the workpiece 1 from the previous process (marking mechanism). 3, the holding mechanism 3 in a state in which the workpiece 1 is rotationally displaced on the workpiece holding mechanism 3 to perform mark detection and positioning of the workpiece 1, and the workpiece 1 after the inspection process is sent to a subsequent process (such as a charge / discharge test). The states of the state holding mechanism 3 are separately displayed. Similarly, the post-process work holding mechanism 3 'is also one, but it is divided into two parts depending on the state. The operation of FIG. 3 will also be described in the description of the overall operation of this embodiment described later.

In FIG. 1, in the previous step, a mark 1 is marked on the outer periphery of the battery can by a mark printing mechanism (not shown) with respect to the work 1 in which the interior of the electrode material with tabs is completed. Mark printing mechanism, when the pre-Me electrode material is roughly determined the position of the tab when it is inserted into the battery can is fixedly disposed in accordance with the position, automatically work as part of the assembly line work 1 When detected automatically, a mark is added. As such a mark printing mechanism, for example, an ink jet printer is used.

  In the tab inspection process, the workpiece detection sensor 2 is transported by the lithium ion secondary battery in which the interior of the electrode material with the tab is completed and a mark is provided on a part of the outer wall of the battery can. It is detected that the workpiece is moved to the workpiece holding mechanism 3 via the mechanism 31 (see FIG. 3). The workpiece detection sensor 2 is constituted by, for example, an optical sensor.

  The mark detection sensor 5 is for detecting a mark on the work 1, and is constituted by, for example, a laser type sensor for detecting reflected light at the mark position of the emitted laser. The mark detection sensor 5 is fixedly arranged at a predetermined position toward the workpiece 1, and when the workpiece 1 is rotated by the rotational displacement imparting mechanism 4, when the mark comes on the optical axis 5 a of the laser beam, The mark is detected by the reflected light. That is, the mark detection sensor 5 detects the mark attached to the workpiece 1 in cooperation with the workpiece rotation displacement applying mechanism 4.

  When the mark is detected by the mark detection sensor 5, the controller 8 functions as rotational displacement control means for stopping the work rotational displacement applying operation by stopping the drive motor 40 of the work rotational displacement applying mechanism 4 based on the detection signal. . By this rotational displacement control, temporary positioning of the workpiece 1 on the workpiece holding mechanism 3 is performed.

  In this embodiment, the workpiece 1 temporarily positioned on the workpiece holding mechanism 3 using the mark as an index is relative to the X-ray 7a of the X-ray imaging apparatus (between the X-ray source 7 and the X-ray detection camera 6). And a tilting mechanism 9 for tilting. The tilt mechanism 9 can tilt the work holding mechanism 3 and the work rotation displacement applying mechanism 4 as one unit. By tilting the workpiece holding mechanism 3, the camera angle of the workpiece 1 is set to be a lateral camera angle (that is, an X-ray imaging camera angle orthogonal to the central axis of the workpiece 1; an angle in which the central axis of the workpiece 1 and the X-ray are orthogonal). Functions as a camera angle switching mechanism that can be switched between a mode for X-ray imaging with a camera and a mode for X-ray imaging at a predetermined oblique camera angle (a camera angle at which the X-rays obliquely intersect the central axis of the workpiece 1) To do. FIG. 1 shows a mode in which X-ray imaging is performed at a predetermined oblique camera angle that is arbitrarily determined for the workpiece 1, and a diagram equivalent to FIG. 5B is shown. That is, the X-ray 7 a irradiated from the X-ray source 7 toward the X-ray imaging camera 6 has an inclination angle that obliquely intersects the center axis O of the workpiece 1. When the tilting mechanism 9 (camera angle switching mechanism) is tilted from the state of FIG. 1 so that the central axis O of the workpiece 1 intersects the X-ray 7a irradiated from the X-ray source 7 perpendicularly, FIG. It is equivalent to the figure shown in

  In this embodiment, the workpiece 1 is tilted via the tilting mechanism 9 to change the angle at which the X-ray 7a intersects the workpiece 1 to switch the lateral angle and the oblique angle of X-ray imaging. This switching is also possible by moving at least one of the camera 6 and the X-ray source 7 with respect to the workpiece 1.

The controller 8 inputs the detection signal from the workpiece detection sensor 2 and the detection signal from the mark detection sensor 5, and sequentially drives the motor 40 of the workpiece rotation displacement applying mechanism 4, the tilt mechanism 9, and the X-ray source 7 in series. Control is performed and a detection signal from the X-ray camera 6 is input, and image processing calculation necessary for tab inspection is executed. That is, the controller 8 extracts the tab in the battery can from the X-ray image captured at an oblique camera angle as shown in FIG. 1 and FIG. 5B, and the actual rotation angle of the tab extraction position with respect to the mark in advance. It also serves as image processing means for calculating the correction amount of the tab position deviation with respect to the mark from the deviation from the set standard rotation angle α ₀ (α ₀ includes zero). Further, when a workpiece temporarily positioned using the mark as an index is imaged at the X-ray imaging position at a camera angle directly beside the workpiece, the workpiece is imaged by rotating the workpiece via the rotational displacement imparting mechanism 4 by the tab displacement correction amount. Functions as position correction means.
(Tab misalignment correction and tab inspection process)
Here, the tab misalignment correction and tab inspection process of this embodiment will be described with reference to the flowchart of FIG. 4A. Prior to the process of the flowchart of FIG. 4A, inter-device correction is performed before this, which will be described after this description. Incidentally, the inter-device correction is performed for error correction because an error occurs in the mounting angle of the mark detection sensor and the positional relationship between the X-ray source and the camera depending on the device.

  Before entering the flow of FIG. 4A, as a pre-process 1, in the process of manufacturing a lithium ion secondary battery in which the electrode material 11 with the tab 12 is built in the battery can 10, the position of the tab is confirmed and the outside of the battery can 10 is removed. A mark indicating the approximate tab position is attached to the wall surface (see FIGS. 2 and 3).

  Next, as shown in FIG. 3, the workpiece 1 is moved to the workpiece holding mechanism 3 of the inspection apparatus by the workpiece conveyance mechanism 31, and the holding mechanism 3 is lifted by a predetermined position so that the torque applying roller 41 of the rotational displacement applying mechanism 4 is moved to the outer periphery of the workpiece 1. The workpiece 1 is rotated on the workpiece holding mechanism 3 by driving the motor 40. When the mark attached to the workpiece 1 comes to the mark detection position by the rotation of the workpiece 1, the motor 40 stops, the rotation of the workpiece 1 stops, and the workpiece 1 is temporarily positioned. The work flow in this case is performed by steps S10 to S12 in FIG. 4A.

  After temporarily positioning the workpiece 1 at the point where the mark is detected as described above, as shown in FIG. 1 and FIG. 5B, the workpiece 1 is X-ray imaged at a predetermined oblique angle, and the tab image is taken from the captured image. Image positions are extracted (steps S13, S14, S15 in FIG. 4A). Details of the tab image extraction method will be described later.

  From the tab image extraction position extracted by the image processing, a tab position deviation Δα with respect to the mark detection position (captured mark) is obtained (step S15). FIG. 12A and FIG. 12B show examples of how to obtain the tab displacement described below.

  As described above, as shown in the example of the X-ray imaging diagram of FIG. 11 and the X-ray imaging schematic diagram of FIG. 8, the outline of the tab 12 can be grasped from the captured image. The edges 12a and 12b of the bent portion between the portion extending in the vertical direction and the portion extending in the lateral direction at the bottom of the battery can are clearly related to the bottom contour of the battery can 10 even if the tab is misaligned. Can be recognized. In addition, since almost half of the perspective elliptical contour that becomes the bottom of the battery can 10 appears in the image, the elliptical contour coordinates can be converted into a perfect circle on the two-dimensional coordinates, for example, by the method shown in the embodiments described later. If the feature point of the tab (for example, the bent edge of the tab) is shown, the rotation angle of the tab extraction position with respect to the mark can be obtained.

In the present invention, from the above points, for example, as shown in FIG. 12A, the actual rotation of the extraction position of the tab 12 with respect to the detection position M ₀ (mark position) of the mark M of the cylindrical battery (work) 1 to be inspected. from the deviation Δα = αn-α ₀ of the standard rotational angle alpha ₀ of predetermined an angular .alpha.n possible to calculate the positional deviation of the tab 12. The standard rotation angle α ₀ is an ideal coverage for X-ray imaging of the tab 12 in the cylindrical battery 10 at a lateral angle when the mark M on the outer periphery of the battery can comes to the position M ₀ detected by the mark detection sensor. of assuming an imaging position E1, which is the rotation angle of the ideal imaged position E1 relative to the mark detection position M _0.

The standard rotation angle α ₀ can be arbitrarily set by arbitrarily changing the mark detection position with respect to the ideal imaged position (the position of the tab that is X-rayed from the side).

In the example shown in FIG. 12A, when the cylindrical battery 10 is rotated in one direction and the mark M reaches an arbitrarily set mark detection position M ₀ , the tab 12 of the cylindrical battery 10 is imaged at a right angle. As an example in the case of the ideal imaged position E1 (shown in FIG. 12 at a position where the elliptical outline of the battery can bottom imaged in perspective and one end of the long diameter line P intersect), the mark detection position M ₀ Α ₀ > 0 is set with respect to the standard rotation angle α ₀ between the target position E1 and the ideal imaged position E1.

In FIG. 12A, the position of the tab 12 (see FIG. 10A, for example) extracted by processing the image of oblique imaging is the intermediate point 12c between the tab edges 12a and 12b, and the major axis H with the ideal imaged position E1. by obtaining the angle intersects the line l connecting the edge midpoint 12c · ellipse center point O as described above and can obtain the deviation Δα of the standard rotational angle alpha ₀ and the actual rotational angle .alpha.n.

In the example shown in FIG. 12B, the standard rotation angle α ₀ is α ₀ = 0, that is, the mark detection position M ₀ (in other words, the mark position M) is matched with the ideal imaged position E1. In this case, if the tab 12 is not misaligned, the tab 12 (specifically, the edge intermediate point 12c) and the position of the mark M coincide with each other. Thus, when the standard rotation angle α ₀ is set to zero and the mark M of the workpiece 1 is detected, the ideal imaged position E1 (mark detection position M ₀ ) and the extraction position 12c of the tab 12 are detected. If the actual rotation angle αn occurs between the two, the angle Δ between the major axis H and the line l connecting the edge intermediate point 12c and the ellipse center point O is obtained as in FIG. 12A. Is obtained as the displacement of the tab relative to the mark.

  This positional deviation angle Δα is stored in the storage device (step S16).

Here, the details of the tab image extraction method executed in step 15 will be described.
(1) First, a binarization process is performed on an X-ray image captured at an oblique angle to extract a workpiece outline (battery can) outline (FIG. 9A).
(2) Next, ellipse extraction which is the outline of the bottom of the battery can 12 is performed as follows. The edges extracted by binarization are approximated to polygons according to Ramer's algorithm. After this, the elliptical arc is applied to the neighboring line divisions and divided into elliptical arcs and straight lines. Finally, an ellipse is created from the elliptical arc part (FIG. 9B).
(3) Next, based on the ratio of the long side and short side of the above-mentioned elliptical outline, the ellipse is converted to a perfect circle as follows. To HomMat2DRotate. The rotation is described by a 2x2 rotation matrix R. This is done for a global (ie fixed) coordinate system. That is, it corresponds to the following series of transformation matrices.

  The point (Px, Py) is a fixed point in the conversion, and this point is not changed even if it is converted using HomMat2DRotate. In order to obtain this action, a transformation is first added to the input transformation matrix that moves a fixed point on the origin of the global coordinate system. Next, rotation is added and finally the fixed point is returned to its original position. This corresponds to a series of transformations:

  Next, affine two-dimensional transformation is performed as follows.

(4) Tab Edge Extraction Next, the tab 12 edge is extracted by an appropriate edge detection method such as the Canny method (FIG. 9C).

  Naturally, other than the target edge is also detected, but this detects the target tab edge by narrowing down under conditions such as angle, length, parallelism and the like as shown in FIG. 9D.

  The narrowing down is performed as follows, for example, under conditions such as the angle, the length, and the parallelism.

In the above embodiment, as shown in FIGS. 12A and 12B, the tab position detection is performed with the center line of the tab edges 12a and 12b as the center line, and the angle Δα with respect to the reference position E1 is calculated. The deviation is obtained, but in addition, the tab position deviation can be obtained as follows.
4-1) Intersection angle between the extension line of the bent part of the tab (detecting the edges 12a and 12b of the bent part) and the extension line H of the major axis of the can bottom ellipse (the horizontal diameter when converted into a perfect circle) α1 is calculated (FIG. 10B).
4-2) Calculate the angle α2 formed by the vertical line and the line connecting the midpoint of the intersection of the extension line of the vertical tab (two left and right sides) and the bottom of the can and the center of the perfect circle (FIG. 10C). .
4-3) An angle α3 formed by a vertical line and a line connecting the midpoint of two points of intersection of the two sides of the bottom side tab with the bottom of the can and the center of the perfect circle is calculated (FIG. 10D). .
4-4) The intersection angle α4 between the intersection of the extension line of the vertical tab and the extension line of the can bottom tab and the extension line of the line connecting the two points and the horizontal line is calculated (FIG. 10E).
4-5) The width W1 of the vertical tab is calculated (FIG. 10F).
4-6) The width W2 of the can bottom side tab is calculated (FIG. 10G).

Here, supplementing the figures 4-5) and 4-6), in the case of a perfect circle, when a mark corresponding to the width of the tab 12 of the same length is placed on the circumference, on the X axis (H line) Then, when you look at the edge position of the mark, it looks different. From that reason, if you know the width, you can know the position of the mark and finally the angle.
4-7) The intersection angle α5 between the vertical tab and the can bottom tab is calculated ((two solutions) (FIG. 10H).
Actually, the deviation of the mark position can be calculated by using the average value of the two solutions and comparing it with the intersection angle α measured with the reference workpiece.
4-8) The intersection angle α6 between the tip edge of the can bottom tab and the horizontal line is calculated. (FIG. 10I)
The displacement of the tab with respect to the mark is corrected by rotationally displacing the temporarily positioned workpiece 1 using the rotational displacement imparting mechanism 4 by Δα stored in step S16 of FIG. 4A described above (step S17).

  After the tab misalignment correction is performed as described above, the following tab inspection process is performed. The workpiece 1 is controlled in position so that the workpiece axis intersects perpendicularly with respect to the X-ray 7 a via the tilting mechanism 9. Thereby, the corrected tab position becomes a lateral angle of X-ray imaging (step S18).

If X-ray imaging is performed in this state, the workpiece 1 is imaged at a position where the tab is at the right lateral angle as shown in FIG. 6, and the tab can be seen clearly (steps S19 and S20). Based on this image, whether or not the state of the tab is appropriate is observed and determined.
(About correction between devices)
In addition, FIG. 4B demonstrates the correction | amendment between apparatuses performed before said tab position shift correction | amendment and a tab test | inspection.

As described above, the correction between the apparatuses is performed because errors occur in the mounting angle of the mark detection sensor and the positional relationship between the X-ray source and the camera. This inter-apparatus correction is performed using a reference work (including a dummy) that has no misalignment between the alignment mark and the tab (standard rotation angle α ₀ ).

  The reference work is set by holding the reference work on the holding mechanism 3 and holding the work, and stopping the work rotation at a position where the mark detection sensor 5 detects the mark while rotating the work rotation displacement applying mechanism 4 in the circumferential direction of the work. Is completed (steps S10 'to S12'). By performing X-ray imaging at this position at an oblique angle as in the above-described positional deviation detection step, and calculating and correcting the positional deviation amount between the marks and tabs as in FIG. 12A or FIG. Correction is performed (step S13 '). After completion, the reference workpiece is transported after releasing the press (steps S14 ′ and S15 ′).

  By performing the tab position deviation correction as described above, the tab can be imaged at the optimum X-ray imaging position, and the tab inspection accuracy can be improved.

  In the above embodiment, in the pre-inspection process, a mark is attached to an arbitrary position on the outer periphery of the work 1 or the position of the tab is grasped in the process of mounting the electrode material on the battery can. The mark indicating the approximate tab position is attached, but if it is possible to give an accurate mark to the tab position by seeing through the tab position in the work 1 in this mark applying process, It is possible to eliminate the need for correction of misalignment between the mark and the tab position.

  In the embodiment described below, the present invention relates to a marking method and an apparatus for applying an accurate mark to a tab position by seeing through the tab position in the workpiece 1 in a mark applying process.

  The marking method and apparatus according to the present embodiment can detect a tab in the battery can if an X-ray image is taken at an angle of 90 degrees with respect to an oblique angle or a lateral angle as in the above-described embodiments. It uses the principle.

  FIG. 14 shows an apparatus provided at a position corresponding to the previous step of FIG.

  In the present embodiment, a work holding mechanism 30 that holds the work 1, a work rotation displacement imparting mechanism 400 that rotationally displaces the work 1 held by the work holding mechanism 30 in the work circumferential direction, and an outer periphery of the battery can of the work. A mark printing mechanism 50 disposed at a predetermined position for attaching a mark, and an X-ray imaging mechanism (X-ray source 70, camera 60) for X-ray imaging of the work 1 at an angle of 90 degrees with respect to an oblique angle or a lateral angle. And).

  Here, the workpiece holding mechanism 30 and the workpiece rotation displacement mechanism 400 (servo motor 401, rotation torque applying roller 402) have the same mechanisms as the workpiece holding mechanism 3 and the workpiece rotation displacement mechanism 4 shown in FIG.

  The mark printing mechanism 50 is configured by, for example, an ink jet printer, and is fixedly disposed at a predetermined position. The position of the mark printing mechanism 50 is fixed at which position in the image when the workpiece 1 is imaged by X-ray.

  In this embodiment, X-ray imaging is performed on the workpiece 1 at an oblique angle or an angle that is 90 degrees with respect to the above-described lateral angle, and the controller 80 performs battery canning by image processing of the oblique angle imaging or 90-degree angle imaging. Detect internal tab positions. This tab position detection method is performed by calculating the rotation angle Δα of the detection position of the tab 12 with respect to the marking position 50 that is predetermined in the X-ray imaging image as shown in FIG. This tab position detection method may be performed in the same manner as described with reference to FIG. 12B. A marking position (mark printing apparatus) 50 may be set at this position instead of the ideal imaging position E1 of FIG.

  In this tab position detection step, if the tab position is not found by X-ray imaging, the workpiece 1 is rotated, for example, by a predetermined rotation angle (for example, every 60 degrees) until the tab position is detected.

  In addition to the tab position detecting means, the controller 80 rotates the workpiece 1 in the positive or negative direction by the rotation angle Δα via the rotational displacement applying mechanism 400 so that the tab position comes to the marking position. Functions as a means. Further, when the tab position comes to the marking position, that is, after the work 1 is rotated by the rotation angle Δα, the controller 8 drives the head of the ink jet printer 50 to mark the mark M on the outer periphery of the battery can. It functions as a printing mechanism control means.

  Thereafter, the workpiece 1 with a mark is carried into the workpiece holding mechanism 3 in the tab inspection process as shown in FIG. In the present embodiment, the tab inspection apparatus is not shown in the figure, but the tab inspection apparatus does not need to correct the misalignment between the mark and the tab position as in the above-described embodiment. The X-ray source 7 and the camera 6 shown in FIG. 5 are used to fix the work 1 so that X-ray imaging is performed at a right lateral angle, and when the mark M is detected, X-ray imaging is performed to check the quality of the tab. That's fine.

  Also in the present embodiment, tab inspection with high accuracy can be performed.

DESCRIPTION OF SYMBOLS 1 ... Cylindrical battery, 2 ... Work detection sensor, 3, 30 ... Work holding mechanism, 4,400 ... Work rotation displacement provision mechanism, 5 ... Mark detection sensor, 6, 60 ... X-ray imaging camera, 7, 70 ... X Radiation source, 8... Controller (work rotation displacement control means, image processing means, work imaged position correction means, 9... Work tilt mechanism (camera angle switching mechanism), 50... Mark printing mechanism (inkjet printer), 80. Workpiece rotation displacement control means, image processing means, mark printing mechanism control means).

Claims (7)

In the inspection process after the manufacturing process of the cylindrical battery in which the electrode material with the tab to be the electrode lead terminal is mounted in the battery can which is the battery case, the cylindrical battery is subjected to X-ray imaging to check the state of the tab inside the battery. In the tab inspection method for a cylindrical battery for inspecting
Prior to the inspection step, in the process of installing the electrode material in the battery can, the position of the tab is grasped, and a mark indicating the approximate tab position is attached on the outer periphery of the battery can,
When the mark comes to the position detected by the mark detection sensor, the rotation angle with respect to the mark detection position of the ideal imaged position where the tab in the cylindrical battery is X-ray imaged at the right lateral angle is the standard rotation angle α ₀ ( α ₀ is is determined in advance in advance and including zero),
After temporary positioning of the cylindrical battery in the circumferential direction at the point where this mark is detected, the cylindrical battery was X-ray imaged at an angle of 90 degrees with respect to the oblique or true lateral angle, and the image was taken. Extracting the image position of the tab from the image, performing image processing to calculate a deviation between the actual rotation angle of the tab extraction position and the standard rotation angle with respect to the actual mark position of the detection target cylindrical battery,
In the subsequent inspection step, tab position deviation correction is performed to rotate the cylindrical battery to be inspected that is temporarily positioned by the mark in a direction to correct the deviation, and the tab of the cylindrical battery is set to a lateral angle. A tab inspection method for a cylindrical battery, characterized in that X-ray imaging is performed with   X-ray imaging of the cylindrical battery to be inspected obliquely or at an angle of 90 degrees with respect to the lateral angle, and the image processing for extracting the image position of the tab from the captured image is performed by the cylindrical battery. The cylindrical battery according to claim 1, wherein an edge of a bent portion between a portion extending in a vertical direction of a tab projected in an X-ray imaging image and a portion extending in a horizontal direction at the bottom of the battery can is extracted. Tab inspection method.   The image processing for extracting the image position of the tab from the captured image by taking an X-ray image of the cylindrical battery to be inspected at an oblique angle or an angle that is 90 degrees with respect to the lateral angle, The tab inspection method for a cylindrical battery according to claim 1, wherein at least one of a portion extending in a vertical direction and a portion extending in a horizontal direction of a tab projected in an X-ray imaging image of the battery is extracted. After the manufacturing process of the cylindrical battery in which the electrode material with the tab to be the electrode lead terminal is mounted in the battery can serving as the battery case, the cylindrical battery is positioned using the mark attached to the outer periphery of the battery can as an index, and the cylinder In the tab inspection method for a cylindrical battery, which inspects the state of the tab inside the battery by X-ray imaging of the battery at a lateral angle,
In the marking step for applying the mark performed in the pre-inspection step, the cylindrical battery is X-ray imaged at an angle of 90 degrees with respect to the oblique angle or the lateral angle, and the oblique angle image or 90 degree angle is obtained. Detecting the tab position inside the battery can by image processing of imaging, calculating the rotation angle of the detection position of the tab with respect to the marking position predetermined in the image of X-ray imaging,
A cylindrical battery tab, wherein the mark is attached to the outer periphery of the battery can by rotating the cylindrical battery in the positive or negative direction by the rotation angle so that the tab position comes to the marking position. Inspection method.   The tab inspection method for a cylindrical battery according to claim 4, wherein the step of finding the tab position by X-ray imaging the cylindrical battery at an oblique angle or a 90-degree angle is performed while rotating the cylindrical battery. A tabular inspection in which a cylindrical battery in which an electrode material with a tab serving as an electrode lead terminal is housed in a battery can is used as a workpiece to be inspected, and the workpiece is imaged by an X-ray camera and the state of the tab is inspected from the image X-ray inspection equipment for
A mark printing mechanism disposed at a predetermined position to mark the outer periphery of the battery can of the workpiece;
A workpiece holding mechanism for holding the workpiece;
A workpiece rotation displacement imparting mechanism for rotationally displacing the workpiece held by the workpiece holding mechanism in the workpiece circumferential direction;
A mark detection sensor which is fixedly arranged at a predetermined position and detects a mark attached to the workpiece in cooperation with the workpiece rotation displacement applying mechanism;
Workpiece rotation displacement control means for stopping the rotation of the workpiece by stopping the workpiece rotation displacement applying operation by the workpiece rotation displacement applying mechanism at the position where the mark is detected;
A mechanism for X-ray imaging of the workpiece positioned with the mark as an index at a right camera angle, and a mechanism for X-ray imaging at an oblique camera angle or a camera angle of 90 degrees with respect to the right lateral angle;
Rotation of the ideal imaged position relative to the mark detection position where the tab in the cylindrical battery is X-ray imaged at a right lateral angle when the mark attached to the outer periphery of the battery can comes to the position detected by the mark detection sensor The angle is set in advance as a standard rotation angle α ₀ (α ₀ includes zero), the tab is extracted from the X-ray image captured at the oblique camera angle or the 90-degree camera angle, and the mark image processing for calculating a correction amount of the positional deviation of the tab with respect to the mark from the deviation between the preset and actual rotation angle of the extraction position of the tabs standard rotation angle α _{0 (α 0} contains zero) for Means,
A workpiece imaged position for rotating the workpiece via the rotational displacement imparting mechanism by an amount of correction of the tab displacement when the workpiece temporarily positioned using the mark as an index is imaged at a right camera angle. And an X-ray inspection apparatus for tab inspection. In a marking device for applying a mark as a mark of the tab to the outside of the battery can of the work, with a cylindrical battery in which the electrode material with a tab serving as an electrode lead terminal is embedded in the battery can
A workpiece holding mechanism for holding the workpiece;
A workpiece rotation displacement imparting mechanism for rotationally displacing the workpiece held by the workpiece holding mechanism in the workpiece circumferential direction;
A mark printing mechanism disposed at a predetermined position to mark the outer periphery of the battery can of the workpiece;
A mechanism for X-ray imaging of the workpiece at an angle of 90 degrees with respect to an oblique angle or a lateral angle;
X-ray imaging of the workpiece is performed at an angle of 90 degrees with respect to the oblique angle or the lateral angle, and the tab position inside the battery can is detected by image processing of the oblique angle imaging or 90-degree angle imaging. Image processing means for calculating a rotation angle of the detection position of the tab with respect to a predetermined marking position in the image of
Rotation control means for rotating the workpiece in the positive or negative direction by the rotation angle via the rotational displacement imparting mechanism so that the tab position comes to the marking position;
And a mark printing mechanism control means for driving the mark printing mechanism to place a mark on the outer periphery of the battery can when the tab position reaches the marking position.

Images