Welding jig and laser welding device including same

Abstract

Provided is a jig for inputting gas to and discharging gas from an object to be laser-welded. A welding jig according to a first embodiment of the present invention may comprise: an outer jig to which gas is input; and an inner jig which is inserted into the outer jig along an insertion direction so as to form a gap with the outer jig, and receives the gas, input to the outer jig, via the gap, and discharges the gas. The outer jig includes: an outer body into which the inner jig is inserted and which forms a gap with the inner jig therebetween; and a pair of inlet parts which are located on opposite sides of the outer body and through which the gas is input into the outer body. Inlet passages, into which gas is input and flows, are formed inside the pair of inlet parts, communication passages communicating the inlet passages and the gap are formed inside the outer body and the pair of inlet parts, and the gas flowing in the pair of inlet passages may flow in opposite directions.

Description

Welding jig and laser welding device including the same

[0001] Cross-citation with related applications

[0002] This application claims the benefit of priority from Korean Patent Application No. 10-2023-0117782, filed September 5, 2023, the entire contents of which are incorporated herein by reference.

[0003] Technology field

[0004] The present invention relates to a welding jig used in a welding process in the process of manufacturing a secondary battery and a laser welding device including the same.

[0005] To address environmental pollution caused by the use of petroleum resources and the resulting energy shortage resulting from petroleum depletion, research and development are underway on power generation based on eco-friendly energy sources. In particular, active research is being conducted on secondary batteries, which offer high utility due to their ability to be repeatedly charged and discharged. Research is also being conducted on various aspects of secondary batteries, including their materials, structure, processes, and stability.

[0006] Common types of secondary batteries include nickel-cadmium batteries, nickel-metal hydride batteries, lithium-ion batteries, and lithium-ion polymer batteries. These batteries are used not only in small products such as digital cameras, DVDs, MP3 players, mobile phones, PDAs, portable game devices, power tools, and e-bikes, but also in larger products requiring high output, such as electric and hybrid vehicles, as well as in power storage devices that store surplus power or renewable energy, and as backup power storage devices.

[0007] To manufacture these secondary batteries, first, an electrode active material slurry is applied to a positive electrode current collector and a negative electrode current collector to manufacture a positive electrode and a negative electrode, and these are laminated on both sides of a separator to form an electrode assembly of a predetermined shape. Then, the electrode assembly is housed in a battery case, filled with electrolyte, and sealed.

[0008] To protect the secondary batteries manufactured in this manner from external shocks, heat, and vibrations, and to secure higher-output and higher-efficiency electrical energy, a battery module is manufactured in which multiple secondary batteries are combined and housed in a case. A control device that transmits and receives electrical signals to the multiple secondary batteries is combined, allowing the multiple secondary batteries to be managed or operated as a single unit.

[0009] When connecting multiple secondary batteries in series or parallel, the electrode leads of the secondary batteries are electrically connected by laser welding. For example, after placing multiple secondary batteries face-to-face, the electrode leads can be aligned vertically and then laser-welded to the target for welding.

[0010] However, there was a problem with the deterioration of weld quality caused by oxidation and spatter generated during laser welding. To prevent this, a method was devised: spraying inert nitrogen gas onto the welding target to block airflow, thereby slowing down the oxidation reaction, and then using a suction device to remove spatter and chemical byproducts. Even in this case, another problem arose: the inconsistent injection of inert gas resulted in an uneven weld surface.

[0011] Specifically, Fig. 1 is a plan view of a welding jig (J) according to a comparative example.

[0012] Referring to Fig. 1, a welding jig (J) according to a comparative example is coupled to a welding device and contacts a welding object (P). For example, the welding device can locally heat and melt the welding object (P) by irradiating it with a laser, thereby welding the object. In this case, the welding jig (J) is mounted and coupled to the lower head portion of the welding device, and fixes the welding device to the welding object (P).

[0013] The welding jig (J) injects an inert gas into the welding object (P) to suppress oxidation reaction by air. For example, the welding jig (J) injects nitrogen gas, among inert gases, into the welding object (P). Specifically, the welding jig (J) receives nitrogen gas from an externally installed gas cylinder through an inlet passage (S1), and moves the nitrogen gas introduced into the inlet passage (S1) into a welding space (S2) that comes into contact with the welding object (P), thereby allowing the nitrogen gas to contact the welding object (P).

[0014] The welding space (S2) is a space that comes into contact with the welding target (P), and is a space through which the laser irradiated from the laser unit passes to reach the welding target (P).

[0015] The injection passage (S1) is formed on both sides of the welding space (S2), and the direction of gas flowing into the pair of injection passages (S1) is unidirectional as shown in Fig. 1. Additionally, the internal passage (S3) connecting the injection passage (S1) and the welding space (S2) is a slot hole structure formed integrally through the passage.

[0016] According to the structure of the welding jig (J) as described above, since nitrogen gas is injected from only one direction and a large amount of nitrogen gas is introduced into the welding space (S2) in a short period of time, there was a problem that the nitrogen gas did not reach the welding target (P) uniformly and spatter was generated irregularly.

[0017] Fig. 2 is a picture showing spatter generated in a part welded by a welding jig (J) according to a comparative example, and Fig. 3 is a picture showing a part welded by a welding jig (J) according to a comparative example.

[0018] Referring to Fig. 2, a phenomenon in which a large amount of spatter is generated is observed in one direction in which nitrogen gas is injected, i.e., in the right direction based on Fig. 2. In other words, a phenomenon in which a large amount of spatter accumulates and piles up on the right side of the welding target is observed. This is because the nitrogen gas injected in one direction actively exchanges gas on the right side, thereby generating more active sparks through laser welding.

[0019] Also, referring to Fig. 3, it can be confirmed that the welding is uneven at the welding target (P). In other words, it can be confirmed that the welding degree of the welding point (Dot) is uneven on the left and right sides, resulting in a deterioration in the welding quality. Specifically, based on Fig. 3, the welding points on the left are relatively evenly welded, while the welding points on the right are unevenly welded, resulting in a deterioration in the welding quality.

[0020] Accordingly, since the above problems occur due to the welding jig (J) according to the comparative example, there is a need for a welding jig that can prevent oxidation reaction and spatter caused by air and can inject inert gas more uniformly into the welding target.

[0021] The problem to be solved by the present invention is to provide a welding jig that blocks air by spraying an inert gas onto a welding target, and a laser welding device including the same.

[0022] Another problem to be solved by the present invention is to provide a welding jig designed to uniformly inject an inert gas into a welding target and a laser welding device including the same.

[0023] In a jig for injecting and discharging gas into a laser welding target, a welding jig according to a first embodiment of the present invention may include an outer jig into which gas is injected, and an inner jig that is inserted into the outer jig along an insertion direction to form a gap with the outer jig, and receives and discharges gas injected into the outer jig through the gap.

[0024] The above outer jig includes an outer body into which the inner jig is inserted and a gap is formed between the inner jig and the outer body, and a pair of inlet portions located on both sides of the outer body for injecting gas into the outer body, an inlet passage through which gas is injected and flows is formed inside the pair of inlet portions, and a communication passage connecting the inlet passage and the gap is formed inside the outer body and the pair of inlet portions, and the directions of the gases flowing in the pair of inlet passages may be opposite to each other.

[0025] The above pair of inlets includes a pair of inlets formed through one surface to communicate with the inlet passage and through which gas is injected, and the directions in which the pair of inlets are formed may be opposite to each other.

[0026] One end of the above-mentioned input passage may be connected to the input port, and the other end of the above-mentioned input passage may be formed to be spaced apart from the other side of the input section, which is the opposite side to one side of the input section, by a predetermined distance.

[0027] The above-mentioned communication passage may be formed in multiple numbers.

[0028] The above-mentioned input passage is formed along the longitudinal direction of the input portion, and the plurality of communication passages can be arranged along the longitudinal direction of the above-mentioned input passage.

[0029] The spacing between the plurality of above-mentioned communication passages may increase along the direction in which the gas is injected into the injection portion.

[0030] The longitudinal direction of the above-mentioned injection passage and the direction in which the plurality of communication passages are formed may be perpendicular to each other.

[0031] The inner jig includes a first portion formed along the insertion direction and a second portion formed along the insertion direction from an end of the first portion and having a cross-sectional area that becomes narrower as it goes in the insertion direction, and the first portion and the second portion can form the gap with the inner surface of the outer jig.

[0032] For the above insertion direction, when the height from the point where the first part and the second part are connected to the end of the second part is H1, and the height from the input part to the end of the outer body is H2, a conditional equation of H1 / H2 being 0.714 to 0.786 can be satisfied.

[0033] A slot hole is formed through the contact surface of the outer body in contact with the welding target, and when the height from the point where the first part and the second part are connected to the end of the second part in the insertion direction is H1, and the length of the slot hole is L1, a conditional equation of H1 / L1 being 0.233 to 0.256 can be satisfied.

[0034] When the height from the point where the first and second parts are connected to the end of the second part in the insertion direction is H1, H1 may be 10 mm to 11 mm.

[0035] An empty space communicating with the gap may be formed on the inner side of the first and second parts.

[0036] A laser welding device according to a second embodiment of the present invention may include a body that forms a laser path through which a laser is transmitted, a welding jig that is coupled to the lower side of the body and contacts a welding target and has a shape formed inside such that the laser path is extended so that the laser transmitted through the body reaches the welding target, and that injects gas into the welding target, a laser unit that irradiates the welding target with a laser along a laser path formed in the body and the welding jig, and an exhaust unit that is formed to penetrate the body and exhausts the gas injected by the welding jig.

[0037] The above welding jig may include an outer jig into which gas is introduced, and an inner jig that is inserted into the outer jig along an insertion direction to form a gap with the outer jig, and through which gas introduced into the outer jig flows in through the gap and transmits the introduced gas to the discharge unit.

[0038] The above outer jig includes an outer body into which the inner jig is inserted and a gap is formed between the inner jig and the outer body, and a pair of inlet portions located on both sides of the outer body for injecting gas into the outer body, an inlet passage through which gas is injected and flows is formed inside the pair of inlet portions, and a communication passage connecting the inlet passage and the gap is formed inside the outer body and the pair of inlet portions, and the directions of the gases flowing in the pair of inlet passages may be opposite to each other.

[0039] The above pair of inlets includes a pair of inlets formed through one surface to communicate with the inlet passage and through which gas is injected, and the directions in which the pair of inlets are formed may be opposite to each other.

[0040] The above communication passage is formed in a plurality along the longitudinal direction of the input portion, and the plurality of communication passages can be arranged along the longitudinal direction of the input passage.

[0041] The spacing between the plurality of above-mentioned communication passages may increase along the direction in which the gas is injected into the injection portion.

[0042] The inner jig includes a first part formed along the insertion direction and having an interior that is in communication with the discharge unit, and a second part formed along the insertion direction from an end of the first part and having a cross-sectional area that becomes narrower as it goes in the insertion direction, and having an interior that is in communication with the interior of the first part, and the first part and the second part can form the gap with the inner surface of the outer jig.

[0043] For the above insertion direction, when the height from the point where the first part and the second part are connected to the end of the second part is H1, and the height from the input part to the end of the outer body is H2, a conditional equation of H1 / H2 being 0.714 to 0.786 can be satisfied.

[0044] A slot hole is formed through the contact surface of the outer body in contact with the welding target, and when the height from the point where the first part and the second part are connected to the end of the second part in the insertion direction is H1, and the length of the slot hole is L1, a conditional equation of H1 / L1 being 0.233 to 0.256 can be satisfied.

[0045] An empty space communicating with the gap is formed on the inner side of the first and second parts, and a slot hole is formed through the contact surface of the outer body that contacts the welding target so that the laser irradiated by the laser unit passes through, and the laser unit can irradiate the laser so that the laser passes through the empty space inside the first and second parts and the slot hole to reach the welding target.

[0046] According to a preferred embodiment of the present invention, by spraying an inert gas onto a welding target to block air, oxidation reaction caused by air is suppressed and the phenomenon of spatter generation is prevented, thereby improving welding quality.

[0047] According to a preferred embodiment of the present invention, problems such as welding defects and spatter can be prevented by constantly injecting an inert gas into a welding target.

[0048] In addition, the configurations according to preferred embodiments of the present invention may include effects that can be easily predicted by those skilled in the art.

[0049] The following drawings attached to this specification illustrate preferred embodiments of the present invention, and together with the detailed description of the invention described below, serve to further understand the technical idea of ​​the present invention, and therefore, the present invention should not be interpreted as being limited to matters described in such drawings.

[0050] Fig. 1 is a plan view of a welding jig according to a comparative example.

[0051] Figure 2 is a picture showing spatter generated in a part welded by a welding jig according to a comparative example.

[0052] Fig. 3 is a drawing showing a part welded by a welding jig according to a comparative example.

[0053] Figure 4 is a perspective view of a welding jig according to a first embodiment of the present invention.

[0054] Figure 5 is a partial cutaway view of a welding jig according to a first embodiment of the present invention.

[0055] Figure 6 is an exploded view of a welding jig according to the first embodiment of the present invention.

[0056] Figure 7 is a planar transmission diagram of a welding jig according to the first embodiment of the present invention.

[0057] Figure 8 is a side view of a welding jig according to a first embodiment of the present invention.

[0058] Fig. 9 is a bottom view of an outer jig according to a first embodiment of the present invention.

[0059] Fig. 10 is a cross-sectional view of a laser welding device according to a second embodiment of the present invention.

[0060] Hereinafter, with reference to the attached drawings, preferred embodiments of the present invention will be described in detail so that those skilled in the art can easily implement the invention. However, the present invention may be implemented in various different forms and is not limited or restricted by the following examples.

[0061] 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.

[0062] 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.

[0063] First embodiment

[0064] FIG. 4 is a perspective view of a welding jig (11) according to a first embodiment of the present invention, FIG. 5 is a partial cutaway view of a welding jig (11) according to a first embodiment of the present invention, FIG. 6 is an exploded view of a welding jig (11) according to a first embodiment of the present invention, and FIG. 7 is a planar transparency view of a welding jig (11) according to a first embodiment of the present invention.

[0065] Referring to FIGS. 4 to 7, a welding jig (11) according to the first embodiment of the present invention can contact a welding object and inject an inert gas into the welding object. For example, during a laser welding process, the welding jig (11) can inject nitrogen gas, an inert gas, into the part to be laser-welded to block contact of air with the welding object and reduce the phenomenon of spatter generation due to welding.

[0066] However, inert gases are not limited to nitrogen gas, and may include various other gases that do not react with hydrogen and oxygen in the air.

[0067] The central portion of the welding jig (11) is formed to allow the laser to pass through, and the laser can reach the welding target by passing through the welding jig (11). In this case, the welding jig (11) receives nitrogen gas from an externally installed gas supply device (not shown) and injects and discharges the nitrogen gas to the welding target, thereby suppressing oxidation reaction due to air and further improving the welding quality.

[0068] Here, the welding target may be a portion of an electrode lead formed by extending from an electrode assembly or a portion of an electrode tab formed on the electrode assembly.

[0069] In the case of a pouch-type secondary battery, an electrode lead is a part that is connected to the electrode assembly and exposed to the outside of the pouch case, and can serve as an electrode terminal that is electrically connected to another secondary battery or an external device.

[0070] These electrode leads are joined in a state where they overlap each other, and the multiple electrode leads can be joined to each other by heating and thermally melting them through laser welding.

[0071] Additionally, when multiple electrode leads are in close contact with each other, the welding jig (11) can function to apply pressure to the upper surfaces of the multiple electrode leads to bring the multiple electrode leads into closer contact with each other. This is because, in order to improve welding quality, the welding process must be performed in a more closely contacted state with the multiple electrode leads.

[0072] The welding jig (11) may include an outer jig (110) and an inner jig (111).

[0073] The outer jig (110) may be positioned outside the inner jig (111). In other words, the inner jig (111) may be positioned inside the outer jig (110). In addition, gas may be introduced into the outer jig (110), and the gas introduced into the outer jig (110) may flow into the inner jig (111). For example, the inner jig (111) may be inserted into the outer jig (110) along the insertion direction so as to form a gap (110c) with the outer jig (110). The inner jig (111) may receive the gas introduced into the outer jig (110) through the gap (110c) and discharge it.

[0074] Here, the insertion direction may mean, with reference to FIG. 6, a downward direction in which the inner jig (111) moves toward the outer jig (110). In other words, when the inner jig (111) is positioned above the outer jig (110), the inner jig (111) moves downward along the insertion direction and is inserted into the outer jig (110), thereby allowing the outer jig (110) and the inner jig (111) to be combined.

[0075] The outer jig (110) may include an outer body (1100) and a pair of input portions (1101).

[0076] An inner jig (111) may be inserted into the outer body (1100). For example, the outer body (1100) may form an empty space on the inner side, and the inner jig (111) may be inserted into the empty space on the inner side of the outer body (1100). In this case, as described above, a gap (110c) is formed between the inner surface of the outer body (1100) and the inner jig (111), so that the outer body (1100) and the inner jig (111) may be spaced apart from each other by a certain interval.

[0077] The cross-sectional area of ​​the outer body (1100) may become smaller as it moves toward the welding target. For example, the lower surface of the outer body (1100) may be in contact with the welding target, and the outer body (1100) may have a shape in which the cross-sectional area becomes smaller as it moves downward.

[0078] A slot hole (110e) may be formed through the contact surface of the outer body (1100) that comes into contact with the welding target. The laser may reach the welding target by penetrating through the slot hole (110e). For example, if an inner jig (111) is positioned inside the outer body (1100), and the inner jig (111) also forms an empty space inside, the laser may pass through the empty space of the inner jig (111) and reach the slot hole (110e), thereby reaching the welding target.

[0079] Through the structure of the slot hole (110e) as described above, welding can be performed by irradiating the laser with the slot hole (110e) in contact with the welding target, and nitrogen gas can be injected into the welding target. With this structure, the weldability of the welding target can be improved, and the phenomenon of external foreign substances entering the welding target during the welding process can be prevented.

[0080] A pair of inlet ports (1101) may be located on both sides of the outer body (1100). In addition, the inlet ports (1101) may inject gas into the outer body (1100). In other words, gas is injected into the inlet ports (1101), and the gas injected into the inlet ports (1101) may be moved to the outer body (1100).

[0081] Specifically, a pair of inlets (1101) may include a pair of inlets (110d) formed through one surface and through which gas is injected. That is, each inlet (110d) may be formed on one surface of each inlet (1101). In this case, the directions in which the pair of inlets (110d) are formed may be opposite to each other.

[0082] An injection passage (110a) through which gas is injected and flows may be formed inside the injection unit (1101). A pair of injection ports (110d) may be connected to each of the injection passages (110a). The directions of the gases flowing in the pair of injection passages (110a) may be opposite to each other.

[0083] One end of the input passage (110a) may be connected to the input port (110d). The other end of the input passage (110a) may be formed to be spaced apart from the other surface of the input portion (1101), which is the opposite surface to one surface of the input portion (1101), by a predetermined distance. That is, a pair of input passages (110a) may extend from the input ports (110d) formed on opposite sides toward the other surface of the input portion (1101), but may not extend to the other surface of the input portion (1101). In other words, a pair of input passages (110a) may extend in opposite directions from the input ports (110d).

[0084] A communication passage (110b) that connects the input passage (110a) and the gap (110c) may be formed inside the outer body (1100) and the pair of input portions (1101). For example, a plurality of communication passages (110b) may be formed, and the direction in which the communication passages (110b) are formed and the direction in which the input passages (110a) are formed may be perpendicular to each other. In other words, the longitudinal direction of the input passage (110a) and the direction in which the plurality of communication passages (110b) are formed may be perpendicular to each other.

[0085] Specifically, the input portion (1101) may be formed along the side surface of the outer body (1100), and the input passage (110a) may be formed along the longitudinal direction of the input portion (1101). At this time, a plurality of communication passages (110b) may be respectively arranged along the longitudinal direction of the input passage (110a), and the communication passages (110b) may be formed to be perpendicular to the longitudinal direction of the input passage (110a).

[0086] The spacing between the plurality of communication passages (110b) may increase along the direction in which the gas is injected into the inlet (1101). In other words, the spacing between the plurality of communication passages (110b) may increase as it moves away from the inlet (110d). In other words, the spacing between the plurality of communication passages (110b) may gradually increase along the direction in which the injection passages (110a) are formed from the inlet (110d).

[0087] By virtue of the characteristic that gas flows in opposite directions in a pair of input passages (110a) and the characteristic that the gap between a plurality of communication passages (110b) increases along the direction of gas input, the welding jig (11) can reduce the deviation in gas flow rate between the left and right sides of the welding target. In addition, the welding jig (11) can reduce the deviation in gas concentration between the left and right sides of the welding target.

[0088] As a result, the gas flow rate and gas concentration are maintained uniformly on the left and right sides of the welding target, so that the inert gas is uniformly distributed over the welding target, thereby preventing welding from being performed unevenly due to oxidation reaction and spatter. That is, by the welding jig (11) according to the first embodiment of the present invention, welding can be performed more uniformly, and the welding quality can be improved.

[0089] The significance and effect of the feature that gas flows in opposite directions in a pair of injection passages (110a) and the feature that the gap between multiple communication passages (110b) increases along the direction of gas injection will be described in more detail in the experimental contents and result table described later.

[0090] The inner jig (111) may include an inner body (1112), a first part (1110), and a second part (1111).

[0091] The inner body (1112) can be coupled to the outer jig (110). For example, the inner body (1112) can be positioned on the upper side of the outer body (1100) and between the pair of input portions (1101). In other words, the inner body (1112) can be inserted and coupled between the outer body (1100) and the pair of input portions (1101) so as to be surrounded by the outer body (1100) and the pair of input portions (1101).

[0092] The first part (1110) may be formed along the insertion direction. For example, the first part (1110) may be formed to extend from the inner body (1112) toward the welding target. In other words, the first part (1110) may be formed to extend downward from the inner body (1112). That is, the outer body (1100) includes a shape that protrudes downward from a pair of input portions (1101), and the first part (1110) may be formed to extend from the inner body (1112) along the direction in which the outer body (1100) protrudes.

[0093] The second part (1111) may be formed along the insertion direction from the end of the first part (1110). For example, one end of the first part (1110) may be connected to the inner body (1112), and the other end of the first part (1110) may be connected to the second part (1111). In other words, the first part (1110) may be formed to extend downward from the inner body (1112), and the second part (1111) may be formed to extend downward from the lower surface of the first part (1110).

[0094] The cross-sectional area of ​​the second part (1111) may become narrower as it goes in the insertion direction. That is, the second part (1111) may include a shape in which the width becomes narrower as it goes downward.

[0095] The first part (1110) and the second part (1111) can form a gap (110c) with the inner surface of the outer jig (110). That is, in a state where the inner body (1112) is coupled to the upper surface of the outer body (1100), the first part (1110) and the second part (1111) can be formed to be spaced apart from the inner surface of the outer body (1100) by a certain distance. By forming the first part (1110) and the second part (1111) to be spaced apart from the outer body (1100), a gap (110c) can be formed between the first part (1110) and the second part (1111) and the outer body (1100).

[0096] An empty space communicating with a gap (110c) may be formed on the inner side of the first part (1110) and the second part (1111). For example, the second part (1111) may include a central hole (111a) formed through the gap (110c) to communicate with the empty space on the inner side of the first part (1110).

[0097] As a result, the gas injected into the inlet (110d) moves along the injection passage (110a) to the communication passage (110b), and the gas introduced into the communication passage (110b) passes through the central hole (111a) along the gap (110c) and can then reach the empty space inside the first part (1110) and the second part (1111).

[0098] As the gas moves along the gap (110c) through the central hole (111a), it comes into contact with the welding target located in the slot hole (110e), and the gas can suppress an oxidation reaction occurring at the welding target. In addition, spatter or foreign substances generated at the welding target can be moved along the gas through the central hole (111a) to the empty space inside the first part (1110) and the second part (1111), and can then be discharged.

[0099] In addition, the laser beam directed toward the welding jig (11) passes through the empty space inside the first part (1110) and the second part (1111) and the central hole (111a), thereby reaching the welding target located in the slot hole (110e) and performing laser welding.

[0100] Figure 8 is a side view of a welding jig (11) according to the first embodiment of the present invention.

[0101] Referring to FIG. 8, when the height from the point where the first part (1110) and the second part (1111) are connected to the end of the second part (1111) in the insertion direction is H1, and the height from the input part (1101) to the end of the outer body (1100) is H2, a conditional equation of H1 / H2 being 0.714 to 0.786 can be satisfied. In other words, when the height (H2) from the input part (1101) to the end of the outer body (1100) is 14 mm, the height (H1) from the point where the first part (1110) and the second part (1111) are connected to the end of the second part (1111) in the insertion direction can be 10 to 11 mm.

[0102] Figure 9 is a bottom view of an outer jig (110) according to the first embodiment of the present invention.

[0103] Referring to FIG. 9, when the height from the point where the first part (1110) and the second part (1111) are connected to the end of the second part (1111) in the insertion direction is H1, and the length of the slot hole (110e) is L1, a conditional equation of H1 / L1 being 0.233 to 0.256 can be satisfied. In other words, when the length (L1) of the slot hole (110e) is 43 mm, the height (H1) from the point where the first part (1110) and the second part (1111) are connected to the end of the second part (1111) in the insertion direction can be 10 mm to 11 mm.

[0104] According to a structure with such a ratio, the gas introduced into the welding jig (11) flows at a more uniform speed, and the concentration of the gas reaching the welding target can be maintained more uniformly. Specifically, unlike the comparative example, the welding jig (11) according to the first embodiment of the present invention can reduce the deviation in the gas flow rate between the left and right sides of the welding target. In addition, unlike the comparative example, the welding jig (11) according to the first embodiment of the present invention can reduce the deviation in the gas concentration between the left and right sides of the welding target.

[0105] As a result, the gas flow rate and gas concentration are maintained uniformly on the left and right sides of the welding target, so that the inert gas is uniformly distributed over the welding target, thereby preventing welding from being performed unevenly due to oxidation reaction and spatter. That is, by the welding jig (11) according to the first embodiment of the present invention, welding can be performed more uniformly, and the welding quality can be improved.

[0106] Below, the experimental results and experimental details for demonstrating the effectiveness of the present invention are described. Specifically, multiple experiments were conducted while varying the specific structure of the welding jig. The uniformity of the inert gas flow rate and the uniformity of the inert gas concentration in the gas flowing through the welding target were measured for each specific structure of the welding jig. In this case, nitrogen gas is preferred as the inert gas for the experiments.

[0107] The height (H2) from the inlet to the end of the outer body is 14 mm, and the length of the slot hole (L1) is 43 mm. An inert gas is injected into a pair of inlets at a constant speed, and the flow of the gas is analyzed using a simulation program to measure the uniformity of the flow rate and concentration on the left and right sides of the welding target.

[0108] In the experiment, the experimental examples are classified according to 1) the shape of the chimney, 2) the direction in which the inert gas is injected, and 3) the height (H1) from the point where the first and second parts are connected to the end of the second part in the insertion direction.

[0109] Specifically, with respect to the shape of the communication passage, the structure connecting the injection passage and the gap is classified into 1) a slit shape in the form of a single hole, 2) a structure in the form of multiple holes with equal spacing between them, and 3) a structure in the form of multiple holes with non-equal spacing in which the spacing increases along the gas injection direction (first embodiment of the present invention).

[0110] Next, with respect to the direction of injection of the inert gas, it is classified into 1) a case where the gas is injected in the same direction into a pair of inlets as in the comparative example (in this case, a pair of inlets are formed in the same direction), and 2) a case where the gas is injected in opposite directions as in the first embodiment of the present invention.

[0111] Finally, the height (H1) from the point where the first and second parts are connected to the end of the second part in the insertion direction is classified into 2 mm, 5 mm, 8 mm, 10 mm, and 11 mm.

[0112] In this way, each experimental example is set differently for each specific structure, and a table for multiple experimental examples with different experimental conditions is as shown in Table 1 below.

[0113] Experimental example, chimney shape, gas injection direction, height (H1), 1, single hole (slit type), same direction, 2 mm, 25 mm, 38 mm, 4, 10 mm, 5, 11 mm, 6, opposite direction, 2 mm, 7, 5 mm, 8, 9, 10 mm, 10, 11 mm, 11, multiple holes (equally spaced), same direction, 2 mm, 12, 5 mm, 13, 14, 10 mm, 15, 11 mm, 16, multiple holes (equally spaced), opposite direction, 2 mm, 17, 5 mm, 18, 19, 10 mm, 20, 11 mm, 21, multiple holes (unequally spaced), same direction, 2 mm, 22, 5 mm, 38 mm, 24, 10 mm, 25, 11 mm, 26, opposite direction, 2 mm, 27, 5 mm, 28, 29, 10 mm, 30, 11 mm

[0114] For each experimental example, the uniformity of the flow rate and the uniformity of the gas concentration of the welding target are measured, and the welding target is divided into the left and right sides to measure the uniformity of the flow rate and the uniformity of the gas concentration.

[0115] Specifically, = Local speed of the left (L) or right (R) welding target, = Average speed of the left (L) or right (R) welding target, = Local area of ​​the left (L) or right (R) welding target, = Area of ​​the left (L) or right (R) welding target, = Mass fraction of the left (L) or right (R) welding target, = When the average mass fraction of the left (L) or right (R) welding target is 0, the coefficients for the left velocity uniformity, right velocity uniformity, left concentration uniformity, and right concentration uniformity are as shown in Equations 1 to 4 below.

[0116] <Formula 1>

[0117] Left speed uniformity =

[0118] <Formula 2>

[0119] Right speed uniformity =

[0120] <Formula 3>

[0121] Left concentration uniformity =

[0122] <Formula 4>

[0123] Right concentration uniformity =

[0124] First, based on the case where the height (H1) is 10 mm, the results of measuring the flow uniformity and concentration uniformity on the left and right sides of the welding target according to the shape of the flue passage and the gas injection direction are as shown in Table 2 below.

[0125] Experimental example: Left velocity uniformity, Right velocity uniformity, Difference in velocity uniformity, Left concentration uniformity, Right concentration uniformity, Difference in concentration uniformity, 40.5900.5100.0801.0001.0000.00090.5860.6010.0151.0001.0000.000140.6900.8210.1311.0001.0000.000190.6730.6940.0211.0001.0000.000240.6370.7410.1041.0001.0000.000290.7170.7140.0031.0001.0000.000

[0126] Next, the shape of the communication passage is a shape of multiple holes formed at unequal intervals, and the results of measuring the uniformity of the flow rate on the left and right sides of the welding target according to the height (H1) from the point where the first and second parts are connected to the end of the second part in the insertion direction, based on the case where the gas is injected in opposite directions, are as shown in Table 3 below.

[0127] Experimental example: Left velocity uniformity, Right velocity uniformity, Difference in velocity uniformity 260.5170.5240.007270.7140.6890.025280.5120.4800.032290.7200.7170.003300.7700.7640.006

[0128] As a result, as in the welding jig (11) according to the first embodiment of the present invention, the gap between the plurality of communication passages (110b) is structured so that the gap increases along the gas injection direction (unequal gap structure), the gas injection directions are opposite to each other, and the height (H1) is 10 mm to 11 mm, it can be confirmed that the difference in uniformity between the left and right sides of the welding target is the lowest. Therefore, according to the welding jig (11) according to the first embodiment of the present invention, since the gas flow rate and gas concentration for the left and right sides of the welding target are maintained uniform, the inert gas is uniformly distributed on the welding target, and welding can be prevented from being performed unevenly due to oxidation reaction and spatter. That is, by the welding jig (11) according to the first embodiment of the present invention, welding can be performed more uniformly, and the welding quality can be improved.

[0129] Second embodiment

[0130] Hereinafter, a laser welding device (1) according to a second embodiment of the present invention will be described. The laser welding device (1) according to the second embodiment of the present invention relates to a welding device equipped with a welding jig (11) according to the first embodiment of the present invention described above. Any description that overlaps with the description of the welding jig (11) according to the first embodiment of the present invention described above will be omitted.

[0131] Fig. 10 is a cross-sectional view of a laser welding device (1) according to a second embodiment of the present invention.

[0132] Referring to Fig. 10, a laser welding device (1) according to a second embodiment of the present invention can perform a laser welding process by irradiating a laser onto a welding target. For example, the laser welding device (1) can perform a welding process by, while in close contact with the welding target, transmitting a laser along a path penetrated within the device to reach the welding target, and heating and thermally fusion-bonding the welding target by the laser.

[0133] Additionally, the laser welding device (1) can inject nitrogen gas, which is an inert gas, into the welding target to block contact of air with the welding target and reduce the phenomenon of spatter generation due to welding.

[0134] A laser welding device (1) may include a body (10), a welding jig (11), a laser unit (13), and an exhaust unit (12).

[0135] The body (10) can form a laser path through which the laser is transmitted. For example, the inner side of the body (10) can be formed as a penetration to form a path through which the laser is transmitted. In other words, the body (10) can form an empty space on the inner side so that the laser irradiated from the laser unit (13) described later passes through the inner side and reaches the welding target. In addition, the body (10) can include a structure in which a welding jig (11) and a discharge unit (12) described later are combined.

[0136] The welding jig (11) can contact the welding target and inject an inert gas into the welding target. For example, the welding jig (11) can be attached to the lower side of the body (10) and can contact the welding target. The welding jig (11) receives nitrogen gas from an externally installed gas supply device (not shown) and injects and discharges the nitrogen gas into the welding target, thereby suppressing oxidation reactions due to air and further improving the welding quality.

[0137] The welding jig (11) may include a shape on the inside in which a laser path formed in the body (10) is extended so that the laser transmitted through the body (10) reaches the welding target. In other words, the central portion of the welding jig (11) is formed through which the laser passes, and the laser can pass through the welding jig (11) to reach the welding target.

[0138] The welding jig (11) may include an outer jig (110) and an inner jig (111). The outer jig (110) may be positioned outside the inner jig (111). In other words, the inner jig (111) may be positioned inside the outer jig (110). In addition, gas may be introduced into the outer jig (110), and the gas introduced into the outer jig (110) may flow into the inner jig (111). For example, the inner jig (111) may be inserted into the outer jig (110) along the insertion direction so as to form a gap (110c) with the outer jig (110). The inner jig (111) may receive the gas introduced into the outer jig (110) through the gap (110c) and discharge it.

[0139] The outer jig (110) may include an outer body (1100) and a pair of input portions (1101).

[0140] An inner jig (111) may be inserted into the outer body (1100). For example, the outer body (1100) may form a hollow space on the inner side, and the inner jig (111) may be inserted into the hollow space on the inner side of the outer body (1100). The cross-sectional area of ​​the outer body (1100) may become smaller as it moves toward the welding target.

[0141] A slot hole (110e) may be formed through the contact surface of the outer body (1100) that comes into contact with the welding target. The laser may reach the welding target by penetrating through the slot hole (110e). For example, if an inner jig (111) is positioned inside the outer body (1100), and the inner jig (111) also forms an empty space inside, the laser may pass through the empty space of the inner jig (111) and reach the slot hole (110e), thereby reaching the welding target.

[0142] A pair of inlets (1101) may be positioned on both sides of the outer body (1100). In addition, the inlets (1101) may inject gas into the outer body (1100). Specifically, the pair of inlets (1101) may include a pair of inlets (110d) formed through one surface and through which gas is injected. That is, each inlet (110d) may be formed on one surface of each inlet (1101). In this case, the directions in which the pair of inlets (110d) are formed may be opposite to each other.

[0143] An injection passage (110a) through which gas is injected and flows may be formed inside the injection unit (1101). A pair of injection ports (110d) may be connected to each of the injection passages (110a). The directions of the gases flowing in the pair of injection passages (110a) may be opposite to each other.

[0144] One end of the input passage (110a) may be connected to the input port (110d). The other end of the input passage (110a) may be formed to be spaced apart from the other side of the input section (1101), which is the opposite side to one side of the input section (1101), by a predetermined distance. A pair of input passages (110a) may be formed to extend in opposite directions from the input port (110d).

[0145] A communication passage (110b) that connects the input passage (110a) and the gap (110c) may be formed inside the outer body (1100) and the pair of input portions (1101). A plurality of communication passages (110b) are arranged along the longitudinal direction of the input passage (110a), and the communication passages (110b) may be formed to be perpendicular to the longitudinal direction of the input passage (110a).

[0146] The spacing between the plurality of communication passages (110b) may increase along the direction of gas injection into the inlet (1101). In other words, the spacing between the plurality of communication passages (110b) may increase as the distance from the inlet (110d) increases.

[0147] The inner jig (111) may include an inner body (1112), a first part (1110), and a second part (1111).

[0148] The inner body (1112) can be coupled to the outer jig (110). For example, the inner body (1112) can be positioned on the upper side of the outer body (1100) and between a pair of input portions (1101).

[0149] The first portion (1110) may be formed along the insertion direction. For example, the first portion (1110) may be formed to extend from the inner body (1112) toward the welding target.

[0150] The second part (1111) can be formed along the insertion direction from the end of the first part (1110). For example, one end of the first part (1110) can be connected to the inner body (1112), and the other end of the first part (1110) can be connected to the second part (1111).

[0151] The cross-sectional area of ​​the second part (1111) may become narrower as it goes in the insertion direction. That is, the second part (1111) may include a shape in which the width becomes narrower as it goes downward.

[0152] The first part (1110) and the second part (1111) can form a gap (110c) with the inner surface of the outer jig (110). That is, in a state where the inner main body (1112) is coupled to the upper surface of the outer main body (1100), the first part (1110) and the second part (1111) can be formed spaced apart from the inner surface of the outer main body (1100) by a certain distance.

[0153] An empty space communicating with a gap (110c) may be formed on the inner side of the first part (1110) and the second part (1111). For example, the second part (1111) may include a central hole (111a) formed through the gap (110c) to communicate with the empty space on the inner side of the first part (1110).

[0154] As a result, the gas injected into the inlet (110d) moves along the injection passage (110a) to the communication passage (110b), and the gas introduced into the communication passage (110b) passes through the gap (110c) to the central hole (111a) and then reaches the empty space inside the first part (1110) and the second part (1111). The gas that reaches the empty space inside the first part (1110) and the second part (1111) can be discharged to the outside through the discharge unit (12) described later.

[0155] When the height from the point where the first part (1110) and the second part (1111) are connected to the end of the second part (1111) in the insertion direction is H1, and the height from the input part (1101) to the end of the outer body (1100) is H2, a conditional equation of H1 / H2 being 0.714 to 0.786 can be satisfied. In other words, when the height (H2) from the input part (1101) to the end of the outer body (1100) is 14 mm, the height (H1) from the point where the first part (1110) and the second part (1111) are connected to the end of the second part (1111) in the insertion direction can be 10 to 11 mm.

[0156] Additionally, when the height from the point where the first part (1110) and the second part (1111) are connected to the end of the second part (1111) in the insertion direction is H1, and the length of the slot hole (110e) is L1, a conditional equation of H1 / L1 being 0.233 to 0.256 can be satisfied. In other words, when the length (L1) of the slot hole (110e) is 43 mm, the height (H1) from the point where the first part (1110) and the second part (1111) are connected to the end of the second part (1111) in the insertion direction can be 10 mm to 11 mm.

[0157] The laser unit (13) can irradiate a laser to a welding target along a laser path formed in the body (10) and the welding jig (11). Specifically, the welding jig (11) is formed on the lower side of the body (10), and the lower surface of the welding jig (11) is in contact with the welding target, and the welding jig (11) and the body (10) can include a portion formed to penetrate vertically from the welding target.

[0158] For example, a laser path can be formed that penetrates along a slot hole (110e) from a welding target, a space between an outer jig (110) and an inner jig (111), a central hole (111a), an inner empty space of the first part (1110) and the second part (1111), and an inner empty space of the body (10).

[0159] The laser unit (13) is positioned on the upper side of the body (10) and irradiates the laser in a vertical direction toward the welding target, so that the laser can move along the laser path to reach the welding target, and the welding process can be performed by heating and thermally fusion of the welding target by the laser.

[0160] The discharge unit (12) is formed by penetrating the body (10) and can discharge gas injected by the welding jig (11) to the outside. For example, the interior of the discharge unit (12) can be communicated with the internal empty space of the inner jig (111). Specifically, the gas injected into the outer jig (110) blocks contact of air with the welding target to suppress oxidation reaction, and, while containing foreign substances due to spatter, flows into the internal empty space of the inner jig (111) and can be discharged to the outside along the internal passage of the discharge unit (12).

[0161] The above description is merely an example of the technical idea of ​​the present invention, and those skilled in the art will appreciate that various modifications and variations can be made without departing from the essential characteristics of the present invention.

[0162] Accordingly, the embodiments disclosed in the present invention are not intended to limit the technical idea of ​​the present invention but to explain it, and the scope of the technical idea of ​​the present invention is not limited by these embodiments.

[0163] The scope of protection of the present invention should be interpreted by the claims below, and all technical ideas within the scope equivalent thereto should be interpreted as being included in the scope of the rights of the present invention.

[0164] [Explanation of symbols]

[0165] 1: Laser welding device 10: Body

[0166] 11: Welding jig 12: Discharge unit

[0167] 13: Laser unit 110: Outer jig

[0168] 111: Inner jig 1100: Outer body

[0169] 1101: Input section 110a: Input passage

[0170] 110b: Flue passage 110c: Gap

[0171] 110d: Inlet 110e: Slot hole

[0172] 111a: Central Hall 1110: Part 1

[0173] 1111: Part 2 1112: Inner body

Claims

1. In a jig that injects and discharges gas to the laser welding target, An outer jig into which the gas is injected; and It includes an inner jig that is inserted into the outer jig along the insertion direction to form a gap with the outer jig, and receives and discharges gas introduced into the outer jig through the gap. The above outer jig is, An outer body into which the inner jig is inserted and a gap is formed between the inner jig and the outer body; and It includes a pair of inlet portions located on both sides of the outer body and for injecting gas into the outer body, A gas is injected into the inside of the above pair of inlet ports to form a flowing injection passage, A communication passage is formed inside the outer body and a pair of input sections to connect the input passage and the gap, A welding jig in which the directions of gas flowing in the above pair of input passages are opposite to each other.

2. In paragraph 1 The above pair of inlets includes a pair of inlets formed through one surface to communicate with the inlet passage and through which gas is injected, A welding jig in which the directions in which the above pair of inlets are formed are opposite to each other.

3. In paragraph 2 One end of the above input passage is connected to the input port, The other end of the above-mentioned input passage is formed with a welding jig spaced apart from the other side of the input section, which is the opposite side to one side of the input section, by a predetermined distance.

4. In paragraph 3 The above-mentioned chimney is a welding jig formed in multiple pieces.

5. In paragraph 4 The above-mentioned input passage is formed along the length direction of the input portion, A welding jig in which the plurality of above-mentioned communication passages are arranged along the longitudinal direction of the above-mentioned input passage.

6. In paragraph 5 A welding jig in which the spacing between the plurality of above-mentioned communication passages increases along the direction in which the gas is injected into the injection portion.

7. In paragraph 5 A welding jig in which the longitudinal direction of the above-mentioned input passage and the direction in which the plurality of communication passages are formed are perpendicular to each other.

8. In paragraph 1 The above inner jig is, A first part formed along the insertion direction; and A second part is formed along the insertion direction from the end of the first part, and includes a cross-sectional area that becomes narrower as it goes in the insertion direction. A welding jig in which the first and second parts form the gap with the inner surface of the outer jig.

9. In paragraph 8 A welding jig in which, with respect to the insertion direction, the height from the point where the first part and the second part are connected to the end of the second part is H1, and the height from the input part to the end of the outer body is H2, the conditional equation H1 / H2 is 0.714 to 0.786 is satisfied.

10. In paragraph 8 A slot hole is formed through the contact surface of the outer body that comes into contact with the welding target, A welding jig, wherein the conditional equation H1 / L1 is 0.233 to 0.256, where H1 is the height from the point where the first and second parts are connected to the end of the second part in the insertion direction, and L1 is the length of the slot hole, is satisfied.

11. In paragraph 8 A welding jig, wherein when the height from the point where the first and second parts are connected to the end of the second part in the insertion direction is H1, H1 is 10 mm to 11 mm.

12. In paragraph 8 A welding jig in which a hollow space communicating with the gap is formed on the inner side of the first and second parts.

13. A body that forms a laser path through which the laser passes; A welding jig that is coupled to the lower side of the body, comes into contact with a welding target, and includes a shape formed on the inside such that the laser path is extended so that a laser transmitted through the body reaches the welding target, and injects gas into the welding target; A laser unit that irradiates a laser to the welding target along a laser path formed in the body and the welding jig; and It includes a discharge unit formed by penetrating the body and discharging gas injected by the welding jig, The above welding jig is, An outer jig into which the gas is injected; and An inner jig is inserted into the outer jig along the insertion direction to form a gap with the outer jig, and gas introduced into the outer jig flows in through the gap and transmits the introduced gas to the discharge unit. The above outer jig is, An outer body into which the inner jig is inserted and a gap is formed between the inner jig and the outer body; and It includes a pair of inlet portions located on both sides of the outer body and for injecting gas into the outer body, A gas is injected into the inside of the above pair of inlet ports to form a flowing injection passage, A communication passage is formed inside the outer body and a pair of input sections to connect the input passage and the gap, A laser welding device in which the directions of gases flowing in the pair of input passages are opposite to each other.

14. In Article 13 The above pair of inlets includes a pair of inlets formed through one surface to communicate with the inlet passage and through which gas is injected, A laser welding device in which the directions in which the pair of input ports are formed are opposite to each other.

15. In Article 13 The above-mentioned communication passage is formed in multiple numbers along the length of the input portion, A laser welding device, wherein the plurality of communication passages are arranged along the longitudinal direction of the input passage.

16. In Article 15 A laser welding device in which the spacing between the plurality of above-mentioned communication passages increases along the direction in which the gas is injected into the injection portion.

17. In Article 13 The above inner jig is, A first part formed along the insertion direction and having an interior communicating with the discharge unit; and A second part is formed along the insertion direction from the end of the first part, has a cross-sectional area that becomes narrower as it goes in the insertion direction, and has an interior that is connected to the interior of the first part. A laser welding device wherein the first and second parts form the gap with the inner surface of the outer jig.

18. In Article 17 A laser welding device, wherein, with respect to the insertion direction, when the height from the point where the first part and the second part are connected to the end of the second part is H1, and the height from the input part to the end of the outer body is H2, the conditional equation H1 / H2 is 0.714 to 0.786 is satisfied.

19. In Article 17 A slot hole is formed through the contact surface of the outer body that comes into contact with the welding target, A laser welding device, wherein the conditional equation H1 / L1 is 0.233 to 0.256, where H1 is the height from the point where the first and second parts are connected to the end of the second part in the insertion direction, and L1 is the length of the slot hole, is satisfied.

20. In Article 17 An empty space is formed inside the first and second parts and is connected to the gap, A slot hole is formed through the contact surface of the outer body that comes into contact with the welding target so that the laser irradiated by the laser unit passes through it. The above laser unit is a laser welding device that irradiates a laser so that the laser passes through the inner empty space of the first part and the second part and the slot hole to reach the welding target.

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