Laser welding apparatus

Abstract

The present invention relates to a laser welding apparatus. The laser welding apparatus, according to one aspect of the present invention, may comprise: a first laser generation unit capable of emitting a first laser that travels along a first path; a second laser generation unit capable of emitting a second laser; a path adjustment unit provided on the first path and adjusting a traveling path so that the second laser travels along the first path; and a focus adjustment unit positioned at a rear end of the path adjustment unit on the first path and capable of moving focal positions of the first and second lasers.

Description

laser welding device

[0001] Cross-citation with related applications

[0002] This application claims the benefit of priority from Korean Patent Application No. 10-2024-0093132, dated July 15, 2024, the entire contents of which are incorporated herein by reference.

[0003] Technology field

[0004] The present invention relates to a laser welding device, and more specifically, to a laser welding device that performs welding by irradiating a laser.

[0005] A laser welding device uses a high-energy laser to weld two parts together. These devices can be used in a variety of processes. For example, they can be used to electrically connect secondary battery electrode leads and bus bars by welding them together.

[0006] More specifically, the recent rapid proliferation of battery-powered electronic devices, such as mobile phones, laptops, and electric vehicles, has led to a rapid increase in demand for high-energy-density secondary batteries. These secondary batteries are equipped with electrode leads for external electrical connection. These electrode leads are provided in the form of conductive films or segmented elements that extend outside the secondary battery.

[0007] A battery module or battery pack can be formed by packaging multiple secondary batteries in a predetermined casing or housing. At this time, the multiple secondary batteries need to be electrically connected in a predetermined manner. The multiple secondary batteries can be electrically connected via a busbar. To achieve this, the electrode leads need to be welded to the busbar, and a laser welding device can be used for this purpose.

[0008] Meanwhile, as illustrated in Fig. 1, when welding multiple electrode leads (A1, A2) to a bus bar (B), there are cases where the focus of the laser emitted from the laser welding device (1) must be moved. For example, even if the bus bar (B) is laid flat horizontally, if there is a thickness difference between the electrode leads (A1, A2), the focus of the laser must be moved accordingly.

[0009] However, laser welding equipment often emits multiple lasers. For example, one of the multiple lasers may be a high-energy welding laser for performing the welding, while another may be an inspection laser for inspecting weld quality.

[0010] Conventional laser welding devices required individual control of each laser to shift the focus. Consequently, variations in focus shifting could easily cause the laser foci to shift out of alignment. This resulted in insufficient laser energy being delivered to the welding target, and difficulties in properly inspecting the welded result, resulting in poor weld quality.

[0011] The present invention has been devised to solve the above problems, and the object of the present invention is to provide a laser welding device in which the focal points of different lasers can be moved together to the same degree.

[0012] The tasks of the present invention are not limited to the tasks mentioned above, and other tasks not mentioned will be clearly understood by those skilled in the art to which the present invention pertains from the description below.

[0013] According to one aspect of the present invention, a laser welding device is provided, comprising: a first laser generating unit capable of emitting a first laser that proceeds along a first path; a second laser generating unit capable of emitting a second laser; a path adjusting unit provided on the first path to adjust a path for the second laser to proceed along the first path; and a focus adjusting unit positioned at a rear end of the path adjusting unit on the first path to move focus positions of the first and second lasers.

[0014] At this time, a focusing unit is further included on the first path, which can focus the first and second lasers, and the focus adjustment unit can be positioned between the focusing unit and the path adjustment unit.

[0015] At this time, the focus adjustment unit may further include a first adjustment lens positioned on the first path; and an actuator capable of moving the first adjustment lens along the first path.

[0016] At this time, the actuator may be formed of a voice coil motor (VCM).

[0017] At this time, the focus adjustment unit may further include a second adjustment lens positioned at the front end of the first adjustment lens on the first path.

[0018] At this time, the first adjusting lens may be formed as a convex lens with one side convex, and the second adjusting lens may be formed as a convex lens with the side convex in the direction opposite to the first adjusting lens.

[0019] At this time, the first adjusting lens may be formed as a concave lens with one side concave, and the second adjusting lens may be formed as a concave lens with one side concavely sunken toward the first adjusting lens.

[0020] At this time, a refracting unit may be further included, positioned in front of the path control unit on the first path, to refract the first laser into parallel light parallel to the first path.

[0021] At this time, the path control unit may include a reflective mirror that passes the first laser and reflects the second laser.

[0022] At this time, the first laser and the second laser may have different wavelengths.

[0023] At this time, the wavelength of the first laser may be 1000 nm to 1100 nm, and the wavelength of the second laser may be 850 nm to 950 nm.

[0024] At this time, one of the first and second laser generating units may be configured to emit a laser for performing laser welding, and the other of the first and second laser generating units may be configured to emit a laser with a smaller output (power) than either of the first and second laser generating units.

[0025] In a laser welding device according to one aspect of the present invention, a focus adjustment unit capable of moving the focus of the first and second lasers is provided at the rear end of a path adjustment unit that aligns the paths of the first and second lasers, so that the focus of the first and second lasers can be moved simultaneously to the same degree by the focus adjustment unit. This can minimize the deviation between the laser foci, thereby improving the welding quality.

[0026] The effects of the present invention are not limited to the effects described above, and effects not mentioned can be clearly understood by a person having ordinary skill in the art to which the present invention pertains from this specification and the attached drawings.

[0027] FIG. 1 is a schematic drawing showing a process of welding an electrode lead to a bus bar by a laser welding device according to a first embodiment of the present invention.

[0028] FIG. 2 is a schematic drawing of a laser welding device according to a first embodiment of the present invention.

[0029] FIG. 3 is a schematic drawing of a focus adjustment unit of a laser welding device according to a first embodiment of the present invention.

[0030] FIG. 4 is a drawing for explaining that the focus of the laser is moved toward the welding device side by the focus adjustment unit of FIG. 3.

[0031] FIG. 5 is a drawing for explaining that the focus of the laser is moved away from the welding device by the focus adjustment unit of FIG. 3.

[0032] FIG. 6 is a schematic drawing of a focus adjustment unit of a laser welding device according to a second embodiment of the present invention.

[0033] FIG. 7 is a schematic drawing of a focus adjustment unit of a laser welding device according to a third embodiment of the present invention.

[0034] Preferred embodiments of the present invention are described in detail so that those skilled in the art can easily implement them. However, the present invention may be implemented in various different forms and is not limited or restricted by the following examples.

[0035] In order to clearly explain the present invention, a detailed description of a part that is irrelevant to the description or a related known technology that may unnecessarily obscure the gist of the present invention has been omitted, and when adding reference signs to components of each drawing in this specification, the same or similar reference signs are attached to the same or similar components throughout the specification.

[0036] In addition, terms and words used in this specification and claims should not be interpreted as limited to their usual or dictionary meanings, but should be interpreted as meanings and concepts that conform to the technical idea of ​​the present invention based on the principle that the inventor can appropriately define the concept of the term to explain his or her own invention in the best way.

[0037] FIG. 1 is a schematic diagram showing a process of welding an electrode lead to a bus bar by a laser welding device according to a first embodiment of the present invention. FIG. 2 is a schematic diagram showing a laser welding device according to a first embodiment of the present invention. FIG. 3 is a schematic diagram showing a focus adjustment unit of a laser welding device according to a first embodiment of the present invention. FIG. 4 is a diagram explaining that the focus of a laser is moved toward the welding device by the focus adjustment unit of FIG. 3. FIG. 5 is a diagram explaining that the focus of a laser is moved away from the welding device by the focus adjustment unit of FIG. 3.

[0038] FIGS. 1 to 5 disclose a welding device (hereinafter, referred to as a welding device) (1) according to a first embodiment of the present invention. Referring to FIGS. 1 and 2, the welding device (1) according to the first embodiment of the present invention may be a device capable of welding two or more members using a laser. For example, the welding device (1) may emit multiple lasers to weld a first electrode lead (A1) and a second electrode lead (A2) to a bus bar (B).

[0039] The welding device (1) according to the first embodiment of the present invention can move the focus of the laser. For example, the welding device (1) can move the focus of the laser by the difference (d) between the distance between the first electrode lead (A1) and the welding device (1) and the distance between the second electrode lead (A2) and the welding device (1). At this time, the welding device (1) according to the first embodiment of the present invention can move the focal points of multiple emitted lasers together to the same degree. Through this, the welding device (1) can perform a welding process with high quality.

[0040] Referring to FIG. 2, a welding device (1) according to a first embodiment of the present invention may include first and second laser generating units (10, 20). The first laser generating unit (10) may be configured to emit a first laser (L1), and the second laser generating unit (20) may be configured to emit a second laser (L2). The first and second laser generating units (10, 20) may be implemented using various known technologies.

[0041] In this embodiment, the first laser generating unit (10) can emit the first laser (L1) so that it proceeds along a first path (R1). At this time, the first path (R1) may be a path proceeding from left to right with reference to FIG. 2. If necessary, the first path (R1) may be bent or turned. For example, the first path (R1) may be bent or turned by a lens, prism, or reflector placed on the path.

[0042] At this time, in the present embodiment, the first laser (L1) may be a welding laser that directly performs the welding process. To this end, the first laser generation unit (10) may have a relatively high output (power), and the wavelength of the first laser (L1) may be 1000 nm to 1100 nm. However, the wavelength or output of the first laser (L1) may be appropriately changed as needed.

[0043] In the present embodiment, the second laser generating unit (20) can emit the second laser (L2) so that it proceeds along the second path (R2). At this time, the second path (R2) may be a path proceeding from the upper side to the lower side based on FIG. 2. The second path (R2) is not parallel to the first path (R1), but may be inclined or perpendicular. If necessary, the second path (R2) may be bent or turned. For example, the second path (R2) may be bent or turned by a lens, prism, or reflector placed on the path.

[0044] At this time, in the present embodiment, the second laser (L2) may be an inspection laser for inspecting the quality of welding performed by the first laser (L1). For this purpose, the second laser generating unit (20) may have a relatively lower output than the first laser generating unit (10), and the wavelength of the second laser (L2) may be 850 nm to 950 nm. However, the wavelength or output of the second laser (L2) may be appropriately changed as needed.

[0045] Meanwhile, in the present embodiment, the first laser generating unit (10) is configured to emit a welding laser and the second laser generating unit (20) is configured to emit an inspection laser. However, if necessary, the second laser generating unit (20) may be configured to emit a welding laser and the first laser generating unit (10) may be configured to emit an inspection laser.

[0046] Referring to FIG. 2, a welding device (1) according to a first embodiment of the present invention may include a path adjustment unit (40). The path adjustment unit (40) may be a unit that adjusts the path of the second laser (L2) so that the second laser (L2) proceeds along the first path (R1).

[0047] In this embodiment, the path control unit (40) may be positioned on the second path (R2). The path control unit (40) may be positioned on the first path (R1). The path control unit (40) may be positioned where the first path (R1) and the second path (R2) intersect.

[0048] In the present embodiment, the path control unit (40) may be configured to transmit the first laser (L1) and reflect the second laser (L2). For example, the path control unit (40) may include a reflector having a predetermined material coated on one surface. In this case, the material may be a material that transmits lasers of 1000 nm to 1100 nm and reflects lasers of 850 nm to 950 nm.

[0049] Accordingly, the path control unit (40) can control the path of the second laser (L2) so that the second laser (L2) proceeds along the first path (R1). Based on the first path (R1), the third laser (L3) can proceed from the rear end of the path control unit (40). At this time, the third laser (L3) can include the first and second lasers (L1, L2).

[0050] Meanwhile, in the present embodiment, the path control unit (40) is configured as a reflector with one surface coated. However, the path control unit (40) is not particularly limited as long as it can direct the second laser (L2) along the first path (R1). For example, the path control unit (40) may also be configured as a specially treated lens, prism, or a combination thereof.

[0051] Referring again to FIG. 2, the welding device (1) according to the first embodiment of the present invention may include a refracting unit (30). The refracting unit (30) may be a unit that refracts the first laser (L1) into parallel light (or parallel laser). For example, the refracting unit (30) may include a convex lens with both sides protruding convexly.

[0052] In the present embodiment, the refracting unit (30) may be placed on the first path (R1). At this time, the refracting unit (30) may be positioned in front of the path adjustment unit (40) with respect to the first path (R1). In other words, the refracting unit (30) may be positioned between the first laser generation unit (10) and the path adjustment unit (40). Through this, the refracting unit (30) may refract the first laser (L1) into a parallel laser without affecting the second laser (L2).

[0053] Referring again to FIG. 2, the welding device (1) according to the first embodiment of the present invention may include a focusing unit (50). The focusing unit (50) may be a unit capable of concentrating the first and second lasers (L1, L2) into focal points (Fa to Fc). For example, the focusing unit (50) may include a convex lens with convex sides on both sides. Through this, the first laser (L1) can be focused and perform welding with high energy, and the second laser (L2) can transmit information for welding quality inspection at a high resolution.

[0054] In this embodiment, the focusing unit (50) may be positioned at the rear end of the path control unit (40) with respect to the first path (R1). As a result, the first and second lasers (L1, L2) included in the third laser (L3) may be focused together at a focus (Fa to Fc) by the focusing unit (50).

[0055] Meanwhile, referring to FIGS. 1 and 2, the welding device (1) according to the first embodiment of the present invention may include a focus adjustment unit (60). The focus adjustment unit (60) may be a unit for moving the focus (Fa to Fc) of the laser. For example, the focus adjustment unit (60) may move the focus of the laser by a difference (d) between the first electrode lead (A1) and the second electrode lead (A2).

[0056] At this time, in the present embodiment, the focus adjustment unit (60) may be positioned at the rear end of the path adjustment unit (40) based on the first path (R1). Therefore, the focus adjustment unit (60) may move the focus of the third laser (L3) that has passed through the path adjustment unit (40).

[0057] Accordingly, the foci of the first and second lasers (L1, L2) included in the third laser (L3) can be moved simultaneously by the same focus adjustment unit (60). That is, the foci of the first and second lasers (L1, L2) can be moved together to the same extent. As a result, the deviation between the first and second lasers (L1, L2) that occurs when the foci are moved can be minimized.

[0058] Referring to FIGS. 2 and 3, the focus adjustment unit (60) of the welding device (1) according to the first embodiment of the present invention may include a first adjustment lens (62) placed on a first path (R1) and an actuator (64) capable of moving the first adjustment lens (62). Although not specifically illustrated, in the present embodiment, the first adjustment lens (62) may be configured as a convex lens with both sides convex.

[0059] In this embodiment, the actuator (64) may be configured to move the first adjustment lens (62) forward and backward along the first path (R1). At this time, the actuator (64) may be formed of a voice coil motor (VCM). Accordingly, the position of the first adjustment lens (62) can be adjusted very finely and accurately. However, the structure or type of the actuator (64) is not particularly limited as long as it can move the first adjustment lens (62).

[0060] Hereinafter, a process for adjusting the focus position of a laser in a welding device (1) according to the first embodiment of the present invention will be specifically described. Referring to FIGS. 2 and 3, as shown in FIG. 3, the position of the first adjustment lens (62a) that does not significantly change the traveling direction of the third laser (L3) is referred to as a neutral position, the third laser (L3) that has passed through the first adjustment lens (62) in the neutral position is referred to as a third a laser (L3a), and the focus of the third a laser (L3a) is referred to as a neutral focus (Fa).

[0061] Referring to FIGS. 2 and 4, the actuator (64) can move the first adjusting lens (62b) forward from the neutral position. The third laser (L3) passing through the first adjusting lens (62b) moved in this manner is referred to as the thirdb laser (L3b). The thirdb laser (L3b) can be refracted so that its propagation direction is more diffused. As a result, the focus (Fb) of the thirdb laser (L3b) can be moved backward from the neutral focus (Fa). In particular, the focuses of the first and second lasers (L1, L2) included in the third laser (L3) can be moved backward together to the same extent.

[0062] Referring to FIGS. 2 and 5, the actuator (64) can move the first adjustment lens (62c) backward from the neutral position. The third laser (L3) that passes through the first adjustment lens (62c) moved in this manner is referred to as a third c laser (L3c). The third c laser (L3c) can be refracted so that its propagation direction becomes more constricted. As a result, the focus (Fc) of the third c laser (L3c) can be moved forward from the neutral focus (Fa). In particular, the focuses of the first and second lasers (L1, L2) included in the third laser (L3) can be moved forward together to the same extent.

[0063] As described above, the focus adjustment unit (60) of the welding device (1) according to the first embodiment of the present invention is positioned at the rear end of the path adjustment unit (40) so as to move the focus of the first and second lasers (L1, L2) simultaneously. As a result, the focus deviation between the first and second lasers (L1, L2) can be minimized, so that the welding process can be performed with higher quality.

[0064] Hereinafter, a laser welding device according to other embodiments of the present invention will be described with different drawings.

[0065] Fig. 6 is a schematic drawing of a focus adjustment unit of a laser welding device according to a second embodiment of the present invention. Fig. 7 is a schematic drawing of a focus adjustment unit of a laser welding device according to a third embodiment of the present invention. In this case, components indicated by the same drawing reference numerals as those indicated in the drawings described above can be understood as identical components performing the same function. Hereinafter, the differences between the second and third embodiments of the present invention and the first embodiment will be described.

[0066] Fig. 6 discloses a focus adjustment unit (160) of a welding device according to a second embodiment of the present invention. The first adjustment lens (162) of the focus adjustment unit (160) according to the second embodiment of the present invention may have one surface convexly protruded toward the rear side of the first path (R1). In this case, the one surface of the first adjustment lens (162) may be a rear surface provided on the rear side of the first path (R1).

[0067] At this time, the focus adjustment unit (160) according to the present embodiment may further include a second adjustment lens (166). The second adjustment lens (166) may be positioned at the front end of the first adjustment lens (162) with respect to the first path (R1).

[0068] At this time, one side of the second adjustment lens (166) may be convexly protruded toward the front side of the first path (R1) so as to face the first adjustment lens (162). Here, the one side of the second adjustment lens (166) may be the front side provided on the front side with respect to the first path (R1).

[0069] Fig. 7 discloses a focus adjustment unit (260) of a welding device according to a third embodiment of the present invention. A first adjustment lens (262) of the focus adjustment unit (260) according to the third embodiment of the present invention may have one surface concavely recessed toward the front side of the first path (R1). In this case, the one surface of the first adjustment lens (262) may be a rear surface provided on the rear side of the first path (R1).

[0070] At this time, the focus adjustment unit (260) according to the present embodiment may further include a second adjustment lens (266). The second adjustment lens (266) may be positioned at the front end of the first adjustment lens (262) with respect to the first path (R1).

[0071] At this time, one side of the second adjustment lens (266) may be concavely recessed toward the rear side of the first path (R1) to face the first adjustment lens (262). Here, the one side of the second adjustment lens (266) may be the front side provided on the front side with respect to the first path (R1).

[0072] Referring to FIGS. 6 and 7 together, in the welding device according to the second and third embodiments of the present invention, the focus position of the third laser (L3) can be moved as the distance between the first adjustment lens (162, 262) and the second adjustment lens (166, 266) is adjusted by the actuator (64).

[0073] Although the present invention has been described above with reference to limited embodiments and drawings, the present invention is not limited thereto, and various embodiments are possible within the scope equivalent to the technical idea of ​​the present invention and the patent claims to be described below by a person having ordinary skill in the art to which the present invention pertains.

[0074]

[0075] [Explanation of symbols]

[0076] 1: Laser welding device

[0077] 10: First laser generating unit

[0078] 20: Second laser generation unit

[0079] 30: Refracting Unit

[0080] 40: Path Control Unit

[0081] 50: Focusing unit

[0082] 60, 160, 260: Focus adjustment unit

[0083] A1, A2: Electrode leads

[0084] B: Bus bar

[0085] L1: First laser

[0086] L2: Second laser

[0087] L3: Third laser

Claims

1. A first laser generating unit capable of emitting a first laser that travels along a first path; A second laser generating unit capable of emitting a second laser; A path control unit provided on the first path to control the path of the second laser so that it proceeds along the first path; and A laser welding device comprising a focus adjustment unit positioned at the rear end of the path adjustment unit on the first path and capable of moving the focus positions of the first and second lasers.

2. In paragraph 1, Further comprising a focusing unit provided on the first path and capable of focusing the first and second lasers, A laser welding device, wherein the focus adjustment unit is positioned between the focusing unit and the path adjustment unit.

3. In paragraph 1, The above focus adjustment unit, a first adjusting lens positioned on the first path; and A laser welding device further comprising an actuator capable of moving the first adjustment lens along the first path.

4. In paragraph 3, The above actuator is a laser welding device composed of a voice coil motor (VCM).

5. In paragraph 3, The above focus adjustment unit, A laser welding device further comprising a second adjusting lens positioned at the front end of the first adjusting lens on the first path.

6. In paragraph 5, The above first adjusting lens is made of a convex lens with one side convex, A laser welding device, wherein the second adjusting lens is a convex lens that is convex in a direction opposite to the first adjusting lens.

7. In paragraph 5, The above first adjusting lens is formed as a concave lens with one side concavely sunken, A laser welding device wherein the second adjusting lens is a concave lens with one side concavely sunken toward the first adjusting lens.

8. In paragraph 1, A laser welding device further comprising a refracting unit positioned in front of the path control unit on the first path and refracting the first laser into parallel light parallel to the first path.

9. In paragraph 1, The above path control unit, A laser welding device comprising a reflective mirror through which the first laser passes and which reflects the second laser.

10. In paragraph 1, A laser welding device wherein the first laser and the second laser have different wavelengths.

11. In paragraph 10, The wavelength of the first laser is 1000 nm to 1100 nm, A laser welding device, wherein the wavelength of the second laser is 850 nm to 950 nm.

12. In paragraph 10, Any one of the first and second laser generating units is configured to emit a laser for performing laser welding, A laser welding device, wherein the other one of the first and second laser generating units is configured to emit a laser with a power lower than that of the other one.

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