Laser Welding Equipment

Abstract

The present invention is a laser welding device in which, when a laser irradiator, a base plate, and an upper mask are combined and an electrode lead and an electrode tab are attached on the lower mask, a laser is irradiated to pass through an opening hole of the base plate and an opening hole of the upper mask to perform welding. The laser welding device includes: a base plate having a fastener protruding from one side; and an upper mask having a fastening hole into which the fastener enters and which is connected to the base plate by being fastened to the fastening hole; the fastener includes a cylinder having an open shape in the longitudinal direction and having an air hole, a piston that is connected to a spring and can slide inside the cylinder and has a section whose diameter decreases toward one side, and a ball connected to the cylinder, and when the fastener enters inside the fastening hole, the ball enters a groove formed on an inner surface of the fastening hole by the piston to prevent it from coming off, and when air is injected into the air hole, the piston slides and the ball can come off the groove.

Description

[Technical field]

[0001] This application claims the benefit of priority based on Korean Patent Application No. 10-2021-0140231, filed on October 20, 2021, and all contents disclosed in the documents of that Korean patent application are incorporated herein by reference.

[0002] The present invention relates to a laser welding apparatus that welds an electrode tab extending from an electrode assembly to an electrode lead having one end extending outside a pouch and the other end located inside the pouch during manufacturing of a secondary battery, and more particularly, to a laser welding apparatus that can improve the convenience of replacing an upper mask. [Background technology]

[0003] 2. Description of the Related Art Lithium secondary batteries, which are rechargeable and dischargeable, lightweight, and have high energy density and power density, are widely used as energy sources for various devices.

[0004] In addition, hybrid electric vehicles (HEVs), plug-in hybrid electric vehicles (PHEVs), battery electric vehicles (BEVs), and electric vehicles (EVs) have been proposed as alternatives to solve the air pollution and greenhouse gas problems of conventional internal combustion engine vehicles that use fossil fuels such as gasoline and diesel vehicles, and lithium secondary batteries are also attracting attention as a power source for such alternative internal combustion engine vehicles.

[0005] Such secondary batteries generally have a structure including an electrode assembly having a structure in which electrodes (negative and positive electrodes) and separators are alternately stacked, an electrolyte (electrolytic solution) that transfers ions to the electrodes, and a case in which the electrode assembly and the electrolyte are housed.

[0006] The lithium secondary battery can be manufactured in various shapes, typically in a cylinder type, a prismatic type, or a pouch type.

[0007] Among these, the pouch-type secondary battery is manufactured by incorporating an electrode assembly for charging and discharging electrical energy and an electrolyte into a pouch, and then sealing the open portion of the pouch.

[0008] The electrode assembly is constructed by alternately stacking negative and positive electrodes together with a separator, and a negative electrode tab protruding from the negative electrode and a positive electrode tab protruding from the positive electrode are manufactured to protrude from the same side or from opposite sides, and each electrode tab (positive electrode tab, negative electrode tab) is welded to an electrode lead (positive electrode lead, negative electrode lead) and mounted in a pouch.

[0009] Thus, with the electrode lead and the electrode tab welded together, one side of the electrode lead is connected to the electrode tab within the pouch, and the other side protrudes outside the pouch to be electrically connected to an external device.

[0010] On the other hand, the electrode lead and the electrode tab are welded by a laser welding device 1 as shown in FIG. 1a.

[0011] The laser welding apparatus 1 includes a lower mask 5 to which electrode leads L and electrode tabs T are attached, a laser irradiator 4 that irradiates a laser to the point where the electrode leads L and electrode tabs T attached on the lower mask 5 are stacked, a base plate 2 coupled to a lower part of the laser irradiator 4, and an upper mask 3 detachably coupled to the base plate 2.

[0012] Furthermore, the laser irradiated from the laser irradiator 4 is irradiated through the opening 2c of the base plate 2 and the opening 3d of the upper mask 3, and welding is performed. That is, the upper end 3e of the opening 3d of the upper mask 3 opens into the opening 2c of the base plate 2. Furthermore, the upper mask 3 has a shape that gradually narrows toward its lower end, and the lower end 3f of the opening 3d is located on the welding point W between the electrode lead L and the electrode tab T.

[0013] During laser welding, inert gas is injected to prevent scattering of spatter and to improve welding quality.

[0014] Referring to Fig. 1b, which shows a side view (top) of a conventional upper mask 3 and a view (bottom) of a base plate 2 inverted upside down, and Fig. 1c, which shows a cross-sectional view of a conventional upper mask 3 coupled to a base plate 2, a locking portion 3a is conventionally provided protruding from the upper mask 3, and a catcher 2a into which the locking portion 3a is fitted and fixed is provided on the base plate 2. That is, in the conventional structure, the upper mask 3 is detached from the base plate 2 by coupling and separating the locking portion 3a and the catcher 2a. Here, the locking portion 3a and the catcher 2a are manually coupled and separated by an operator using a special tool.

[0015] The upper mask 3 has a hollow cone-shaped portion that is sharpened toward the electrode tab T and the electrode lead T, and the openings 3d, 3e, and 3f formed therein are also sharpened toward the end 3f. The upper mask 3 has gas passages 3b and 3c formed therein so that the inert gas is injected from both sides and supplied to the opening end 3f. Here, one of the gas passages, 3c, is supplied with the inert gas through a hole 2b opened in the base plate 2 (right side in FIG. 1c), and the other, 3b, is directly connected to an external pipe or hose H and is supplied thereto (left side in FIG. 1c). The inert gas that has gathered on the opening end 3f side comes into contact with the welding site W, and is then discharged through the opening 3e of the upper mask 3 and the opening 2c of the base plate 2, which are irradiated with the laser.

[0016] Meanwhile, during welding, melting occurs at the welding point, scattering small particle-like spatter S. Such spatter S adheres to the surface of the upper mask 2, and as welding progresses, it accumulates on the surface of the upper mask 3, causing a problem of clogging the gas passages 3b, 3c and the openings 3f, requiring periodic replacement.

[0017] However, in the conventional structure, the upper mask 3 was removed by first separating the external pipe or hose H for injecting the inert gas, and then separating the locking part 3a and the catcher 3b, but this caused a problem that the replacement time differed depending on the skill level of the worker, and the welding process was delayed during the replacement time. Even if a magnet was attached to the locking part 3a to facilitate the connection of the locking part 3a and the catcher 3b by magnetic force, this magnetic force could become a factor of interference during the separation work.

[0018] Therefore, the present invention has been required to provide a new joining structure that allows the upper mask 3 and the base plate 2 to be easily joined and separated. Summary of the Invention [Problem to be solved by the invention]

[0019] SUMMARY OF THE PRESENT DISCLOSURE In view of the above, a main object of the present invention is to provide a laser welding apparatus that can easily perform bonding and separation between an upper mask and a base plate. [Means for solving the problem]

[0020] In order to achieve the above object, the present invention provides a laser welding apparatus in which, when a laser irradiator, a base plate, and an upper mask are combined, and an electrode lead and an electrode tab are attached on the lower mask, a laser is irradiated through an opening hole of the base plate and an opening hole of the upper mask to perform welding. The laser welding apparatus includes: a base plate having a fastener protruding from one side; and an upper mask having a fastening hole into which the fastener enters and which is connected to the base plate by being fastened to the fastening hole; the fastener includes a cylinder having an open shape in the longitudinal direction and having an air hole, a piston that is connected to a spring and can slide inside the cylinder and has a section whose diameter decreases toward one side, and a ball connected to the cylinder, and when the fastener enters inside the fastening hole, the ball enters a groove formed on an inner surface of the fastening hole by the piston to prevent it from coming off, and when air is injected into the air hole, the piston slides and the ball can come off the groove.

[0021] The piston has a flange with a larger diameter at an end thereof, and a spring is disposed on one side of the flange, and an air hole is disposed in the cylinder on the other side.

[0022] A sleeve may be coupled to the upper mask, and fastening holes and grooves may be formed in the sleeve, and the fasteners may be fastened to the sleeve. That is, the fastening holes and grooves may be provided in the upper mask itself, or the sleeve may be provided by being separately attached.

[0023] The base plate is provided with at least two fasteners, and the upper mask is formed with a plurality of fastening holes corresponding to the number of the fasteners.

[0024] The balls are joined in plurality around the circumference of the cylinder.

[0025] The upper mask has a gas passage through which an inert gas moves, and the base plate has an injection hole through which the inert gas is injected into the gas passage, and when the upper mask is coupled to the base plate, the gas passage and the injection hole are connected to each other.

[0026] The upper mask has a portion shaped like a hollow cone with a pointed end, an aperture through which the laser passes is open at the pointed end, and the gas passage is formed to communicate with the aperture.

[0027] The gas passages are formed so as to communicate with each other within the shaped surface that forms the pattern of the upper mask.

[0028] The inert gas injected through the gas passage is exhausted through the openings in the base plate and the openings in the upper mask.

[0029] Nitrogen (N2) may be provided as the inert gas. Effect of the Invention

[0030] In the present invention having the above-mentioned configuration, the upper mask is attached and detached from the base plate by the fastener, and the fastener can be fastened or separated depending on whether air is injected, so that the upper mask can be quickly attached and detached. This allows even an unskilled person to attach and detach the upper mask more quickly and easily.

[0031] The fastening holes through which the fasteners enter and the grooves through which the balls of the fasteners enter may be integrally formed in the upper mask, or may be provided as separate sleeves. Therefore, by adding a sleeve, a conventional upper mask can be used as is.

[0032] The upper mask is structured such that the inert gas is supplied through an injection hole in the base plate, so there is no need to connect or disconnect a separate inert gas injection hose or external piping, and therefore faster replacement is possible. [Brief description of the drawings]

[0033] [Figure 1a] 1 is a perspective view showing a simplified overall shape of a laser welding device; [Figure 1b] 1b is a diagram showing the side shape (top) of a conventional separated upper mask in the laser welding apparatus of FIG. 1a and a conventional base plate turned upside down so that the bottom surface that contacts the upper mask can be seen (bottom). FIG. [Figure 1c] 1 is a diagram showing a cross-sectional shape when an upper mask and a base plate are combined in a conventional manner; [Diagram 2] 1A and 1B are diagrams showing the side shape of a separated upper mask according to the present invention (top) and the state in which a base plate according to the present invention is inverted upside down so that the bottom surface that abuts against the upper mask can be seen (bottom). [Diagram 3] 1 is a diagram showing a cross-sectional shape of a hollow cone-shaped portion when an upper mask and a base plate according to the present invention are combined; [Figure 4] FIG. 2 is a diagram showing a longitudinal cross-sectional shape of a fastener according to the present invention. [Diagram 5] 1A and 1B show a state in which the fastener is locked to the sleeve (i) and a state in which the fastener is unlocked to the sleeve (ii), respectively. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0034] The present invention will now be described in detail with reference to the accompanying drawings so that those skilled in the art can easily carry out the present invention. However, the present invention may be embodied in various different forms and is not limited to the embodiments set forth below.

[0035] In order to clearly describe the present invention, parts that are not relevant to the description will be omitted, and the same reference numerals will be used to refer to the same or similar components throughout the specification.

[0036] Furthermore, the terms and words used in this specification and the claims should not be interpreted in a limited manner to their ordinary or dictionary meanings, but should be interpreted in a manner that is consistent with the technical idea of ​​the present invention, based on the principle that an inventor can appropriately define the concept of a term in order to explain his or her invention in the best possible manner.

[0037] The present invention relates to a laser welding apparatus in which, when a laser irradiator, a base plate, and an upper mask are combined from top to bottom as shown in Figures 1a to 1c, an electrode lead and an electrode tab are attached on the lower mask, a laser is irradiated from the laser irradiator so as to pass sequentially through an opening hole in the base plate and an opening hole in the upper mask, thereby welding the electrode tab and the electrode lead. Hereinafter, an embodiment of the present invention will be described in more detail with reference to the accompanying drawings.

[0038] That is, like the conventional structure described above, the laser welding apparatus according to the present invention is also configured to include a lower mask, a laser irradiator, a base plate 20 and an upper mask 30.

[0039] FIG. 2 is a view showing a side shape of an upper mask 30 according to the present invention after separation (top) and a shape of a base plate 20 according to the present invention turned upside down so that the bottom surface that contacts the upper mask 30 can be seen (bottom).

[0040] Instead of the locking portions and catchers of the conventional structure, in the structure of the present invention, the upper mask 30 is provided with fastening holes (either the fastening holes are integrally formed in the upper mask itself or a sleeve having fastening holes formed therein is attached) and the base plate 20 is provided with fasteners 10 which are secured to the fastening holes.

[0041] That is, the fastener 10 is attached to one surface of the base plate 20 to which the upper mask 30 is attached (i.e., the bottom surface in the arrangement as shown in FIG. 1a) so as to protrude from the surface, and the upper mask 30 has a structure in which a fastening hole is provided.

[0042] 3 is a diagram showing a cross-sectional shape of a hollow cone-shaped portion when the upper mask 30 according to the present invention is coupled to the base plate 20. Note that the portion where the fastener 10 is coupled to the fastening hole is a point located outside of FIG. 3, and is therefore omitted in FIG.

[0043] As shown in the figure, the upper mask 30 has a portion formed in the shape of a hollow cone with a pointed end, and the openings 32a, 32b, and 32c through which the laser is irradiated are formed to open at the pointed end toward the point W where welding is performed, and the gas passage 31 is also formed to communicate with the lower end 32c of the opening.

[0044] The gas passage 31 is a path through which the inert gas moves and is formed to communicate with the inside of the shaped surface forming the pattern of the upper mask 30, so that the inert gas is supplied to the welding point W. The shaped surface means a part of the upper mask 30 that has a thickness to form a cone shape and constitutes the outer shape.

[0045] On the other hand, the upper mask 30 provided in the present invention is different from the conventional structure in that the inert gas is injected through an injection hole 21 formed in the base plate 20, rather than being injected directly from an external pipe or hose H.

[0046] That is, the conventional external pipe or hose H is connected to one side of the injection hole 21 formed in the base plate 20, and when the upper mask 30 is combined with the base plate 20, the other side opens to the gas passage 31 of the upper mask 30.

[0047] Also, as shown in FIG. 3, while the electrode tab T and the electrode lead L are being laser welded, the inert gas injected through the gas passage 31 acts to stabilize the welding at the point W where the welding is performed, and is continuously supplied and discharged through the opening 22 of the base plate 20 and the openings 32a, 32b, and 32c of the upper mask 30.

[0048] That is, the inert gas injected into the gas passage 31 passes through the lower end 32c, the middle part 32b, and the upper end 32a of the opening of the upper mask 30, and is exhausted from the opening 22 of the base plate. Here, nitrogen (N2) may be provided as the inert gas.

[0049] Moreover, the fasteners 10 provided in the present invention are disposed on the outside of the injection holes 21 on both sides of the base plate 20, as shown in FIG.

[0050] FIG. 4 is a diagram showing the vertical cross-sectional shape of fastener 10 according to the present invention, and FIG. 5 is a diagram showing (i) the state when fastener 10 is locked to sleeve 40 (when fastening) and (ii) the state when fastener 10 is unlocked from sleeve 40 (when removal is permitted).

[0051] The fastener 10 has a piston 13 attached inside a cylinder 11, and a ball 15 protruding from the surface of the cylinder 11 according to the sliding position of the piston 13, thereby performing locking or unlocking.

[0052] 1, the cylinder 11 has an open shape in the longitudinal direction, and has an air hole 12 drilled at a predetermined height. The air hole 12 connects the inside and outside of the cylinder 11.

[0053] The piston 13 is mounted so as to slide inside the cylinder 11 with one end connected to a spring 14 so as to be pressurized by a biasing force. The piston 13 has a shape in which the diameter decreases toward one side, or a section in which the diameter decreases toward one side is formed at least in a part of the piston.

[0054] Also, the cylinder 11 has at least one ball 15, preferably a plurality of balls 15, attached at predetermined intervals along the circumference. Although not clearly shown in the figure, the balls 15 are bound and restrained by an elastic body (not shown) and are arranged so that a part of the balls 15 is embedded in the cylinder 11. When the balls 15 come into contact with a part of the piston 13 where the diameter has expanded as the piston 13 slides, they protrude from the surface of the cylinder 11, and when the balls come into contact with a part of the piston 13 where the diameter has contracted, they are embedded and return to their original state.

[0055] Here, the piston 13 has a flange 13a with an expanded diameter at the end (or middle) on the side with a relatively larger diameter, and based on the flange 13a, a spring 14 is disposed on one side (the lower side in FIG. 4) and an air hole 12 is located in the cylinder 11 on the other side (the upper side in FIG. 4).

[0056] 4, the piston 13 has a larger diameter as it goes downward. Therefore, when the piston 13 moves upward by the biasing force of the spring 14, the ball 15 is pressed by the piston 13 and protrudes outward from the surface of the cylinder 11.

[0057] When compressed air is supplied to the air hole 12, the pressure in the space inside the cylinder 11 (more specifically, the space on the opposite side to the space where the spring is placed when the space inside the cylinder is divided based on the flange) increases. As a result, the piston 13 overcomes the biasing force of the spring 14 and descends, and the pressure applied to the ball 15 by the piston 13 is released, so that the ball 15 is buried in the cylinder 11 and restored to its original state.

[0058] Furthermore, the upper mask 30 is provided with a fastening hole at a position corresponding to the position where the fastener 10 is disposed so that the fastener 10 can enter, and a groove is formed on the inner peripheral surface of the fastening hole so as to have a concave shape. The fastening hole and the groove may be integrally formed in the upper mask 30, or a sleeve 40 having a fastening hole 41 and a groove 42 may be provided in a form that is coupled to the upper mask 30.

[0059] FIG. 5 shows a state in which a ring-shaped sleeve 40, which is separately connected to the upper mask 30, has fastening holes 41 and grooves 42 and a fastener 10 is connected to the sleeve 40.

[0060] 5, as shown on the left side, when the fastener 10 enters the inside of the fastening hole 41, the ball 15 enters a groove 42 formed on the inner peripheral surface of the fastening hole 41 by the piston 13, and the fastener 10 is constrained by the sleeve 40. At this time, the fastener 10 is coupled to the base plate 20, and the sleeve 40 is fixed to the upper mask 30, so that the base plate 20 and the upper mask 30 are coupled to each other. That is, by inserting the fastener 10 fixed to the base plate 20 into the fastening hole 41, the base plate 20 and the upper mask 30 are fastened to each other in a one-touch manner.

[0061] Although piston 13 in FIG. 5 is shown as having both a portion with a constant diameter and a portion with a variable diameter, the shape of piston 13 differs depending on the size of ball 15 and the inner diameter of fastening hole 41.

[0062] Furthermore, when air (compressed air) is injected from air hole 12, the pressure in the space opposite spring 14 rises, as shown on the right side of Figure 5, and piston 13 slides backward (toward the bottom of Figure 5). At this time, the point where the diameter of piston 13 is reduced faces ball 15, so the pressure applied to ball 15 is released.

[0063] As a result, the fastener 10 can be removed from the fastening hole 41, and the base plate 20 and the upper mask 30 are separated from each other.

[0064] Meanwhile, in order to appropriately support the weight of the upper mask 30, it is preferable that the base plate 20 is provided with at least two fasteners 10, and the upper mask 30 is provided with a plurality of fastening holes corresponding to the number of the fasteners 10. Also, it is preferable that the balls 15 have a structure in which a plurality of balls are arranged along the circumference of the cylinder 11, in order to more efficiently restrain the fasteners 10.

[0065] In the present invention having the above-mentioned configuration, the upper mask 30 is attached and detached to and from the base plate 20 by the fastener 10, which can be fastened or separated depending on whether air is injected into it, allowing for quick attachment and detachment. This allows even an unskilled person to attach and detach the upper mask more quickly and easily.

[0066] The fastening hole into which the fastener 10 enters and the groove into which the ball of the fastener enters may be formed integrally with the upper mask, or may be provided as a separate sleeve 40. Therefore, by adding the sleeve 40, a conventional upper mask can be used as it is.

[0067] Since the upper mask 30 is structured such that the inert gas is supplied through the injection hole of the base plate 20, there is no need to connect or disconnect a separate inert gas injection hose H or external piping, and therefore, quicker replacement is possible.

[0068] Although the present invention has been described above using limited embodiments and drawings, the present invention is not limited thereto, and various implementations can be made by a person having ordinary knowledge in the technical field to which the present invention pertains within the technical spirit of the present invention and the equivalent scope of the appended claims. [Explanation of symbols]

[0069] 10 Fasteners 20 Base Plate 30 Upper Mask 40 Sleeve

Claims

1. 1. A laser welding apparatus for performing welding by irradiating a laser through an opening hole of the base plate and an opening hole of the upper mask when an electrode lead and an electrode tab are attached on a lower mask in a state where a laser irradiator, a base plate, and an upper mask are combined, A base plate having fasteners protruding from one side thereof; and an upper mask having fastening holes through which the fasteners enter, the fasteners being fastened to the fastening holes to be coupled to the base plate; The fastener includes a cylinder having an open shape in a longitudinal direction and having an air hole drilled therein, a piston that is connected to a spring and can slide inside the cylinder, the piston having a section whose diameter decreases toward one side, and a ball connected to the cylinder, When the fastener enters the inside of the fastening hole, the ball enters a groove formed on the inner surface of the fastening hole by the piston to prevent the ball from coming out, and when air is injected into the air hole, the piston slides and the ball can come out of the groove.

2. The piston has a flange formed at an end portion having a relatively larger diameter, the flange being expanded in diameter.

2. The laser welding device according to claim 1, wherein a spring is disposed on one side of the flange, and the air hole is located in the cylinder on the other side.

3. The laser welding apparatus of claim 2 , wherein the upper mask has a sleeve coupled thereto, the fastening holes and the grooves are formed in the sleeve, and the fasteners are fastened to the sleeve.

4. The laser welding apparatus according to claim 1 , wherein the base plate is provided with at least two fasteners, and the upper mask is formed with a plurality of fastening holes corresponding to the number of the fasteners.

5. The laser welding apparatus of claim 1 , wherein the balls are coupled in plurality along a circumference of the cylinder.

6. a gas passage through which an inert gas moves is formed in the upper mask, and an injection hole through which the inert gas is injected into the gas passage is formed in the base plate; The laser welding apparatus of claim 1 , wherein the gas passage and the injection hole communicate with each other when the upper mask is coupled to the base plate.

7. The upper mask has a portion formed in a hollow cone shape with a pointed end, and the opening hole through which the laser passes is open at the pointed end, The laser welding apparatus according to claim 6 , wherein the gas passage is formed so as to communicate with the opening hole.

8. The laser welding apparatus according to claim 7 , wherein the gas passages are formed so as to communicate with each other inside a shaped surface that forms a pattern of the upper mask.

9. 9. The laser welding apparatus according to claim 8, wherein the inert gas injected through the gas passage is discharged through the openings in the base plate and the openings in the upper mask.

10. 7. The laser welding apparatus of claim 6, wherein the inert gas is nitrogen.

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