Device and method for manufacturing battery pack and laser beam attenuation mechanism

Abstract

To provide a device and a method for manufacturing a battery pack and a laser beam attenuation mechanism capable of increasing the effect of preventing unintended leakage of a laser beam.SOLUTION: This device for manufacturing a battery pack including a joined part in which a plurality of members are connected to each other through laser welding comprises: a laser that emits a laser beam to the joined part; and a laser beam attenuation unit provided at at least a position facing the laser. The laser beam attenuation unit includes a body and at least one of i) an uneven structure provided in the surface of the body to irregularly reflect the laser beam and ii) a refrigerant flow path provided in the body.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present technology relates to a battery pack manufacturing apparatus, a battery pack manufacturing method, and a laser light attenuation mechanism. [Background technology]

[0002] Japanese Patent Laid-Open Publication No. 4-41094 (Patent Document 1) discloses a laser welding machine in which a laser beam is blocked by a laser irradiation block to prevent the beam from being irradiated outside the machine. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 4-41094 Summary of the Invention [Problem to be solved by the invention]

[0004] When irradiating a laser beam in a horizontal direction (close to horizontal), it is necessary to more reliably prevent unintended leakage of the laser beam. Conventional laser welding machines still have room for improvement.

[0005] An object of the present technology is to provide a battery assembly manufacturing apparatus, a battery assembly manufacturing method, and a laser light attenuation mechanism that can improve the effectiveness of preventing unintended laser light leakage. [Means for solving the problem]

[0006] The present technology provides a battery pack manufacturing apparatus, a battery pack manufacturing method, and a laser light attenuation mechanism, which are described below.

[0007] [1] An apparatus for manufacturing a battery pack having a joint where multiple members are joined together by laser welding, the apparatus comprising: a laser that irradiates laser light toward the joint; and a laser light attenuation unit that is provided at least in a position facing the laser and attenuates the laser light, the laser light attenuation unit including a main body and at least one of: i) a concave-convex structure that is provided on the surface of the main body and that diffusely reflects the laser light; and ii) a refrigerant flow path that is provided inside the main body.

[0008] [2] The battery pack manufacturing apparatus according to [1], wherein the laser light is irradiated along a direction within ±45° of the horizontal direction.

[0009] [3] The battery pack manufacturing apparatus according to [1] or [2], wherein the uneven structure includes recesses that reflect the laser light multiple times.

[0010] [4] The battery pack manufacturing apparatus according to any one of [1] to [3], wherein the main body is made of metal.

[0011] [5] The battery assembly manufacturing apparatus according to any one of [1] to [4], wherein the battery assembly includes battery cells having electrode terminals and bus bars joined to the electrode terminals, and the joined portions are provided between the electrode terminals and the bus bars.

[0012] [6] The battery pack manufacturing apparatus described in [5], wherein the battery cells include a rectangular housing having a side surface perpendicular to a first direction, and the laser light is irradiated along the first direction.

[0013] [7] A method for manufacturing a battery pack, comprising the steps of: preparing a battery cell including a portion to be joined with another member; and irradiating a laser beam toward the portion to be joined to join the battery cell and the other member; wherein a laser beam attenuating unit is provided to attenuate the laser beam, and the laser beam attenuating unit includes a main body and at least one of: i) a concave-convex structure provided on the surface of the main body that diffuses the laser beam; and ii) a refrigerant flow path provided inside the main body.

[0014] [8] The method for manufacturing a battery pack according to [7], wherein the laser light is irradiated along a direction within ±45° of the horizontal direction.

[0015] [9] A laser light attenuation mechanism for attenuating laser light, comprising: a main body; and at least one of: i) a concave-convex structure provided on the surface of the main body for diffusing the laser light; and ii) a refrigerant flow path provided inside the main body.

[0016]

[10] The laser light attenuation mechanism according to [9], wherein the laser light is irradiated along a direction within ±45° of the horizontal direction.

[0017]

[11] The laser light attenuation mechanism according to [9] or

[10] , wherein the concave-convex structure includes a recess that reflects the laser light multiple times.

[0018]

[12] The laser light attenuation mechanism according to any one of [9] to

[11] , wherein the main body is made of metal. [Effects of the Invention]

[0019] According to the present technology, it is possible to improve the effect of preventing unintended leakage of laser light, for example, during the manufacturing process of a battery pack. [Brief explanation of the drawings]

[0020] [Figure 1] FIG. 1 is a diagram illustrating an example of a battery pack manufacturing apparatus. [Figure 2] FIG. 10 is a diagram showing a modified example of the battery pack manufacturing apparatus. [Figure 3] 10A and 10B are diagrams illustrating an example of an uneven structure on the surface of a laser light attenuation portion. [Figure 4] 4 is a diagram for explaining the shape of the concave-convex structure shown in FIG. 3. FIG. [Figure 5] 10 shows a modified example of the uneven structure on the surface of the laser light attenuation portion. [Figure 6] 10A and 10B are diagrams illustrating modified examples of the structure of the laser light attenuation portion. DETAILED DESCRIPTION OF THE INVENTION

[0021] Hereinafter, embodiments of the present technology will be described. Note that the same or corresponding parts are denoted by the same reference characters, and description thereof may not be repeated.

[0022] In the embodiments described below, when numbers, amounts, etc. are mentioned, the scope of the present technology is not necessarily limited to those numbers, amounts, etc., unless otherwise specified. Furthermore, in the following embodiments, each component is not necessarily essential to the present technology, unless otherwise specified. Furthermore, the present technology is not necessarily limited to those that achieve all of the effects and advantages mentioned in the present embodiments.

[0023] In this specification, the terms "comprise," "include," and "have" are open-ended. That is, when a certain feature is included, other features may or may not be included.

[0024] Furthermore, when geometric terms and terms expressing positional and directional relationships are used in this specification, such as "parallel," "orthogonal," "45° diagonal," "coaxial," and "along," these terms allow for manufacturing errors and slight variations. When terms expressing relative positional relationships, such as "upper side" and "lower side," are used in this specification, these terms are used to indicate relative positional relationships in a single state, and the relative positional relationships can be reversed or rotated to any angle depending on the installation direction of each mechanism (for example, by turning the entire mechanism upside down).

[0025] In this specification, the term "battery" typically refers to a lithium-ion battery, but the scope of the present technology is not limited thereto and may include other batteries such as nickel-metal hydride batteries and sodium-ion batteries. In this specification, the term "electrode" may collectively refer to a positive electrode and a negative electrode.

[0026] In this specification, a "battery cell" is typically a prismatic cell, but the scope of the present technology is not necessarily limited to this and may include cells of other shapes, such as cylindrical, pouch, and blade types. Furthermore, the "battery cell" can be installed in hybrid electric vehicles (HEVs), plug-in hybrid electric vehicles (PHEVs), and battery electric vehicles (BEVs). However, the use of the "battery cell" is not limited to in-vehicle use.

[0027] Fig. 1 is a diagram showing an example of a manufacturing apparatus for a battery pack 1. As shown in Fig. 1, the battery pack 1 includes a plurality of battery cells 10 and a bus bar 20 that connects the battery cells 10. The manufacturing apparatus according to this embodiment is an apparatus for laser welding electrode terminals (not shown) of the battery cells 10 to the bus bar 20. However, the objects to be laser welded are not limited to the electrode terminals and the bus bar.

[0028] The manufacturing apparatus includes a laser 100 that emits laser light 110, and a laser light attenuation unit 200 (laser light attenuation mechanism) that attenuates the laser light 110. In the example of Fig. 1, the laser light attenuation unit 200 is provided so as to surround the laser 100 and the battery pack 1, but the scope of the present technology is not limited thereto, and it is sufficient that the laser light attenuation unit 200 is provided in a portion that faces at least the laser 100 when the laser light 110 is emitted, like the laser light attenuation unit 200A in Fig. 2.

[0029] 1 and 2, the laser 100 emits the laser light 110 in a substantially horizontal direction (first direction). The side surface of the battery cell 10 that receives the laser light 110 extends in a substantially vertical direction. However, the scope of the present technology is not limited to this, and the laser light 110 may be emitted in a direction within approximately ±45° (preferably within approximately ±30°) from the horizontal direction, for example. Furthermore, the laser light attenuation mechanism according to the present technology can be applied to processes other than the manufacturing process of a battery pack.

[0030] In Figures 1 and 2, the battery pack 1 is placed at a position away from the laser light 110, but by moving the battery pack 1 or moving the laser 100, the part to be joined in the battery pack 1 (in the example of this embodiment, the overlapping part of the electrode terminal and the bus bar) can be aligned with the irradiation position of the laser light 110.

[0031] The laser light attenuating section 200 also functions as a "laser light blocking section" that blocks the laser light 110 emitted from the laser 100 to prevent leakage to the outside.

[0032] When the laser beam 110 is emitted in a lateral direction (horizontally or in a direction at an angle to the horizontal that is equal to or smaller than a predetermined value), it is necessary to more reliably prevent the laser beam 110 from reaching workers passing around the manufacturing equipment.

[0033] The laser light attenuating section 200 in this embodiment can enhance the effect of preventing unintended leakage of the laser light 110. The specific structure of the laser light attenuating section 200 will be described below.

[0034] The main body of the laser light attenuating unit 200 can be made of a metal (iron, aluminum, etc.) that does not allow the laser light 110 to penetrate.

[0035] Fig. 3 is a diagram showing an example of the concave-convex structure of the surface 210 of the laser light attenuating unit 200. As shown in Fig. 3, the surface 210 of the laser light attenuating unit 200 has a concave-convex structure 210A including recesses 211A and protrusions 212A. The recesses 211A are formed as grooves having a substantially V-shape. The extending direction of the recesses 211A (grooves) can be changed as appropriate.

[0036] The concave-convex structure 210A shown in FIG. 3 can attenuate the energy of the laser light 110 by diffusely reflecting the laser light 110.

[0037] The "diffuse reflection" of laser light 110 includes, from a macroscopic perspective, the incident light being reflected multiple times within recesses 211A of uneven structure 210A, and from a microscopic perspective, the generation of scattered light in the reflected light due to the minute and irregular uneven shape of surface 210 (not shown).

[0038] The "diffuse reflection" of the laser light 110 in this embodiment occurs as a result of one or both (combination) of the above-mentioned "multiple reflections" and "generation of scattered light."

[0039] By causing the laser light 110 to be reflected multiple times or to be diffusely reflected on the surface 210 of the laser light attenuating section 200, the energy of the reflected light is attenuated, thereby improving the effect of preventing the laser light 110 from unintentionally leaking outside the manufacturing apparatus (laser irradiation apparatus).

[0040] The minute and irregular uneven shape (microscopic unevenness) on the surface 210 can be formed by, for example, etching, anodizing, hairline finishing, or the like, on the surface 210. The average pitch of the microscopic unevenness is preferably equal to or greater than the wavelength of the irradiated laser beam 110. For example, if the wavelength of the irradiated laser beam 110 is about 1 μm, the average pitch of the microscopic unevenness is preferably equal to or greater than 1 μm. This makes it easier for scattered light to occur.

[0041] Fig. 4 is a diagram for explaining the macroscopic shape (macroscopic unevenness) of the uneven structure 210A shown in Fig. 3. Referring to Fig. 4, the intersection angle (θ) between both side surfaces at the bottom of the recess 211A is preferably about 45° or less (more preferably about 30° or less). This can increase the number of reflections of the laser light 110 within the recess 211A.

[0042] Furthermore, the pitch (D) between the multiple convex portions 212A is preferably equal to or greater than the beam diameter of the laser light 110 emitted from the laser 100. By doing so, the entire beam of the laser light 110 can be organized within the wedges of the concave portions 211A.

[0043] Fig. 5 shows a modified example of the uneven structure of the surface 210 of the laser light attenuating unit 200. As shown in Fig. 5, the uneven structure 210B formed on the surface 210 according to the modified example includes substantially conical holes. In the structure shown in Fig. 5 as well, the laser light 110 is reflected multiple times within the substantially conical holes, causing diffuse reflection and attenuating the energy of the reflected light.

[0044] Fig. 6 is a diagram showing a modified structure of the laser light attenuating unit 200. In the modified example shown in Fig. 6, a refrigerant flow path 221 is provided inside a main body 220 provided on the opposite side (back side) of the front surface 210 of the laser 100. This can promote cooling of the laser light attenuating unit 200.

[0045] When irradiated with laser beam 110, the laser beam attenuating unit 200 generates heat. If the amount of heat generated becomes too large, deformation or damage may occur in the laser beam attenuating unit 200. As shown in the example of Fig. 6, by providing a refrigerant flow path 221 inside the main body 220 of the laser beam attenuating unit 200 to promote cooling of the laser beam attenuating unit 200, it is possible to prevent the amount of heat generated by the laser beam attenuating unit 200 from becoming excessive when irradiated with laser beam 110.

[0046] Although the embodiments of the present technology have been described above, the embodiments disclosed herein should be considered to be illustrative and not restrictive in all respects. The scope of the present technology is defined by the claims, and it is intended to include all modifications within the meaning and scope of the claims. [Explanation of symbols]

[0047] 1 battery pack, 10 battery cell, 20 bus bar, 100 laser, 110 laser light, 200, 200A laser light attenuation portion, 210 surface, 210A, 210B uneven structure, 211A recess, 212A protrusion, 220 main body, 221 refrigerant flow path.

Claims

1. An apparatus for manufacturing a battery assembly having a joining portion where a plurality of members are joined to each other by laser welding, a laser that irradiates the portion to be joined with laser light; a laser light attenuation unit provided at a position facing at least the laser and attenuating the laser light; The laser light attenuating unit The main body and i) a concave-convex structure provided on the surface of the main body, which diffusely reflects the laser light; and ii) a coolant flow path provided inside the main body and at least one of the above.

2. 2. The battery pack manufacturing apparatus according to claim 1, wherein the laser light is emitted along a direction within ±45° with respect to the horizontal direction.

3. 3. The battery assembly manufacturing apparatus according to claim 1, wherein the uneven structure includes recesses that reflect the laser light multiple times.

4. 3. The battery assembly manufacturing apparatus according to claim 1, wherein the main body is made of metal.

5. the assembled battery includes battery cells having electrode terminals and bus bars joined to the electrode terminals, 3. The battery assembly manufacturing apparatus according to claim 1, wherein the joined portion is provided between the electrode terminal and the bus bar.

6. The battery cell includes a rectangular housing having a side surface perpendicular to a first direction, The battery pack manufacturing apparatus according to claim 5 , wherein the laser light is emitted along the first direction.

7. A step of preparing a battery cell including a portion to be joined with another member; a step of irradiating the to-be-joined portion with laser light to join the battery cell and the other member, a laser beam attenuation unit that attenuates the laser beam; The laser light attenuating unit The main body and i) a concave-convex structure provided on the surface of the main body, which diffusely reflects the laser light; and ii) a coolant flow path provided inside the main body and at least one of the above.

8. The method for manufacturing a battery pack according to claim 7 , wherein the laser light is emitted in a direction within ±45° with respect to the horizontal direction.

9. A laser light attenuation mechanism that attenuates laser light, The main body and i) a concave-convex structure provided on the surface of the main body, which diffusely reflects the laser light; and ii) a coolant flow path provided inside the main body and at least one of the above.

10. 10. The laser light attenuation mechanism according to claim 9, wherein the laser light is emitted along a direction within ±45° with respect to the horizontal direction.

11. 11. The laser light attenuation mechanism according to claim 9, wherein the concave-convex structure includes a recess that reflects the laser light multiple times.

12. 11. The laser light attenuation mechanism according to claim 9, wherein the main body is made of metal.

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