KR20240007572A - Welding device, welding method, battery manufacturing device and vehicle manufacturing device - Google Patents

Abstract

Provided are a welding device and a welding method that can improve welding efficiency in the battery manufacturing process, and a battery manufacturing device and an automobile manufacturing device including such a welding device.
A welding device according to one aspect of the present invention includes a laser irradiation unit configured to irradiate a laser, and a laser output control unit configured to control the laser irradiation unit to irradiate a laser of peak power and a laser of base power to the welding area.

Description

Welding device, welding method, battery manufacturing device and automobile manufacturing device {WELDING DEVICE, WELDING METHOD, BATTERY MANUFACTURING DEVICE AND VEHICLE MANUFACTURING DEVICE}

The present invention relates to a welding device, a welding method, a battery manufacturing device, and an automobile manufacturing device. More specifically, a welding device and a welding method capable of improving welding efficiency, and a battery manufacturing device and automobile manufacturing including such a welding device. It's about devices.

Generally, a welding device includes a laser light source and optical components such as a focusing lens to increase the energy density of the laser irradiated from the laser light source.

This welding device can be used, for example, for joining parts constituting a battery module. As an example, a battery module creates a dense structure by overlapping or stacking multiple battery cells (e.g., secondary batteries) mounted on themselves or in a cartridge to provide high voltage and high current, and then electrically connecting them. It can be configured.

In such a battery module, in order to construct a battery module with a stable structure, it is important to ensure good welding between the module case in which the battery cells are accommodated and the end plate configured to cover the bus bar that electrically connects the battery cells. As an example, a welding device may be configured for keyhole welding of welded areas (e.g., between a module case and an end plate).

Meanwhile, in the case of a conventional welding device, welding between the module case and the end plate is performed by the CW (Continuous Wave) laser welding method. In the case of this CW laser welding method, the accumulation of heat input energy in the weld zone may increase depending on the welding time. In this case, there is a problem in that welding defects occur in the welded area due to excessive accumulation of heat energy input in the welded area.

The present invention was made to solve the above-described problems, and its purpose is to provide a welding device and a welding method that can improve welding efficiency, and a battery manufacturing device and an automobile manufacturing device including such a welding device.

However, the technical problems to be solved by the present invention are not limited to the above-mentioned problems, and other problems not mentioned will be clearly understood by those skilled in the art from the description of the invention described below.

A welding device according to one aspect of the present invention includes a laser irradiation unit configured to irradiate a laser, and a laser output control unit configured to control the laser irradiation unit to irradiate a laser of peak power and a laser of base power to the welding area.

Preferably, the laser output control unit may be configured to control the laser irradiation unit so that the welding unit maintains a liquid state.

Preferably, The laser output control unit may be configured to control the laser irradiation unit to alternately irradiate the laser at the peak output and the laser at the base output to the welding area.

Preferably, the laser at the peak output may have an output capable of forming a key hole in the weld, and the laser at the base output may have an output at which penetration is not formed in the weld.

Preferably, the base output laser may have an output capable of maintaining the weld part in a liquid state.

Preferably, the laser output control unit may be configured to control the pulse width of the base output laser.

Preferably, the laser output control unit may be configured to control the pulse frequency of the base output laser.

Preferably, the laser output control unit may be configured to control the output of the laser at the base output.

Preferably, the welding device further includes an inspection unit configured to inspect a welding state in the welded portion after completion of welding by the welding device, and the laser output control unit outputs the basic output according to welding state inspection information provided from the inspection unit. It can be configured to control the output of the laser.

Preferably, the welding device further includes an inspection unit configured to inspect a welding state in the weld portion during welding by the welding device, and the laser output control unit adjusts the base output according to the welding state inspection information provided from the inspection unit. It can be configured to control the output of the laser.

A welding method according to one aspect of the present invention includes the step of irradiating a laser of peak power to the welded portion and the step of irradiating a laser of base output to the welded portion.

The battery manufacturing device according to one aspect of the present invention may include the welding device according to one aspect of the present invention as described above.

An automobile manufacturing device according to an aspect of the present invention may include a welding device according to an aspect of the present invention as described above.

According to an embodiment of the present invention, compared to the prior art, welding defects are minimized by preventing excessive accumulation of heat energy input at the welded portion, and the laser absorption rate of the welded portion is increased by maintaining the liquid state of the welded portion during the welding process, thereby maintaining the same welding speed and Welding productivity can be maintained.

In addition, various other additional effects can be achieved by various embodiments of the present invention. These various effects of the present invention will be described in detail in each embodiment, or descriptions of effects that can be easily understood by those skilled in the art will be omitted.

The following drawings attached to this specification illustrate preferred embodiments of the present invention, and serve to further understand the technical idea of the present invention together with the detailed description of the invention described later. Therefore, the present invention includes the matters described in such drawings. It should not be interpreted as limited to only .
1 is a diagram showing a welding device according to an embodiment of the present invention.
FIG. 2 is a diagram showing changes in laser output by the welding device of FIG. 1.
FIG. 3 is a diagram showing the creation of a key hole in a welded portion according to a change in laser output in FIG. 2.
Figure 4 is a diagram showing the difference in the amount of energy accumulated in the welded area depending on the laser oscillation mode.
Figure 5 is a diagram showing changes in laser output according to oscillation of a conventional pulse laser.
Figure 6 is a diagram showing the laser absorption rate of pure aluminum according to temperature change.
Figure 7 is a diagram showing simulation results for the boundary values of heat conduction welding and keyhole welding.
FIG. 8 is a diagram illustrating a change in the pulse width of a laser by control of a laser output control unit provided in the welding device of FIG. 1.
FIG. 9 is a diagram illustrating a change in the pulse frequency of a laser by control of a laser output control unit provided in the welding device of FIG. 1.
FIG. 10 is a diagram illustrating a change in laser output by control of a laser output control unit provided in the welding device of FIG. 1.
11 and 12 are diagrams showing another control method of a laser using the welding device of the present invention.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the attached drawings. Prior to this, the terms or words used in this specification and claims should not be construed as limited to their usual or dictionary meanings, and the inventor must appropriately use the concept of terms to explain his or her invention in the best way. It must be interpreted as meaning and concept consistent with the technical idea of the present invention based on the principle of definability.

FIG. 1 is a view showing a welding device 10 according to an embodiment of the present invention, FIG. 2 is a view showing a change in laser output by the welding device 10 in FIG. 1, and FIG. 3 is a view showing the laser output in FIG. 2. This is a diagram showing the creation of a key hole (K) in the weld area (W) according to changes in output.

Referring to FIGS. 1 to 3 , the welding device 10 according to an embodiment of the present invention may be configured to perform welding at the weld portion W by irradiating a laser.

As an example, the welded portion W may refer to a joint between component parts of a battery module (not shown). At this time, the battery module may have at least one secondary battery inside.

For example, welding between components of a battery module may be performed using a known key hole welding method. More specifically, the welding device 10 may perform welding between a module case (not shown) and an end plate (not shown) of a battery module for storing a secondary battery therein, but is not limited thereto.

Illustratively, the module case and end plate may include aluminum. That is, the welded portion W may include an aluminum material. However, the welded portion W is not limited to aluminum and may include aluminum and its alloy.

As shown in FIG. 1, the welding device 10 may include a laser irradiation unit 100 and a laser output control unit 200. A portion of this laser irradiation unit 100 may be accommodated in the housing (H). Additionally, the laser output control unit 200 may be provided on the outer surface of the housing (H).

The laser irradiation unit 100 may be configured in the form of an optical system to irradiate laser. Although not shown in detail, the laser may be irradiated to the welding area (W) in the form of a beam.

In one embodiment, the laser irradiation unit 100 may include a laser light source (not shown) and a focusing lens (not shown).

The laser light source may generate the laser.

The focusing lens can improve the energy density of the laser generated from the laser light source. At this time, the laser may pass through the focusing lens and be irradiated to the welding area (W).

The laser output control unit 200, As shown in FIG. 2, the laser irradiation unit 100 can be controlled to irradiate a laser of peak power and a laser of base power to the welding area (W). Here, the base output may be an output with a level lower than the peak output. That is, the laser output control unit 200 can control the laser irradiation unit 100 to irradiate different sizes of output to the same welding area (W). As an example, the laser output control unit 200 may include a processor.

In addition, the laser irradiation unit 100 is controlled by the laser output control unit 200, as shown in FIG. 3. A laser of peak power and a laser of base power may be irradiated so that two or more key holes (K) can be formed overlapping with respect to one weld line in the weld area (W). Here, the key hole K utilizes multiple reflection and absorption of energy in the focal section of the laser beam, and may be formed approximately in the shape of a key hole. At this time, the laser irradiation unit 100 moves with respect to one welding line so that the laser can be irradiated to the welding area (W). The housing H may be moved by a separate moving stage (not shown).

And, after welding is completed for one welding line, the housing H accommodating the laser irradiation unit 100 can be moved to another welding line on the welding unit W. Thereafter, the laser irradiation unit 100 may repeatedly perform the above-described operation for other welding lines on the welding area W under the control of the laser output control unit 200.

As shown in Figure 4 (a), in the case of the conventional CW (Continuous Wave) laser welding method, as the laser irradiation time to the welded area increases, excessive energy is accumulated in the welded area. At this time, the displayed area in the graph of FIG. 4 (a) means the heat input energy accumulated in the welding portion according to the laser irradiation time.

In this case, the weld metal in the weld zone (the part of the metal that melted and solidified during welding as a part of the weld zone) is excessively penetrated, which may cause a melting phenomenon where the weld metal falls locally.

On the other hand, referring to (b) of FIG. 4, in the case of the laser welding method using the welding device 10 of the present invention, the laser irradiation unit 100 irradiates a laser of peak power and a laser of base power to the welding area (W). It can be said that it does. Therefore, compared to the conventional CW laser welding method, the accumulation of heat input energy in the welding area (W) according to the laser irradiation time can be achieved relatively slowly. The laser welding method using the welding device 10 of the present invention is a method of irradiating laser in a combination of the CW laser welding method and the PW (Pulse Wave) laser welding method, and is called quasi-pulse laser welding. It can be said to be a method.

That is, the welding method according to the welding device 10 of the present invention includes the step of irradiating a laser of peak power to the welded portion W and the step of irradiating a laser of base output to the welded portion W.

In this way, when the laser is irradiated to the welded area W in quasi-pulse mode, between the sections where the laser of the peak output is irradiated to the welded area W, a base-output laser with a relatively lower output than the peak output laser is applied to the welded area W. You can investigate at (W). Therefore, in the case of the welding device 10 of the present invention, welding defects can be minimized by preventing excessive accumulation of heat input energy in the welding portion W.

Figure 5 is a diagram showing the change in laser output according to oscillation of a conventional pulse laser, and Figure 6 is a diagram showing the laser absorption rate of pure aluminum according to temperature change.

Referring to Figure 5, in the case of the conventional PW laser welding method, This is a method in which a pulse laser is irradiated to the weld area in a periodic on/off manner.

In the PW laser welding method, as shown by the arrow in Figure 5 (a), in the section where the oscillation of the pulse laser is turned on, the welded portion is melted by irradiation of the pulse laser and changes from a solid state to a liquid state. At this time, it can be said that a key hole is created in the weld zone.

Meanwhile, as shown by the arrow in Figure 5(b), in the section where the oscillation of the pulse laser is off, there is no energy input to the weld, so it can be said that the weld changes from the liquid state back to the solid state.

Referring to FIG. 6, when a pulse laser is oscillated at a certain wavelength (e.g., 1.06㎛) with respect to pure aluminum, the temperature in the solid state compared to the liquid state of the weld zone is based on the melting point of pure aluminum. The absorption rate of the laser can be at least 3.8 times lower.

Therefore, in the section where the oscillation of the pulse laser is turned on again, as shown by the arrow in Figure 5(c), the welded portion that has changed to a solid state in the section shown in Figure 5(b) may need to be melted again. . Therefore, the laser absorption rate at the weld zone in the solid state is relatively lower than the laser absorption rate at the weld zone in the liquid state, resulting in low melting efficiency. This causes the problem of slowing down the welding speed.

On the other hand, the laser output control unit 200 provided in the welding device 10 of the present invention may be configured to control the laser irradiation unit 100 so that the welding unit W maintains a liquid state.

That is, in the welding device 10 of the present invention, the laser output control unit 200 controls the laser irradiation unit 100 to sequentially irradiate the laser at peak power and the laser at base output to the welding area W , W) can be induced to maintain the liquid state without changing from the liquid state to the solid state. To this end, in the case of the welding device 10 of the present invention, unlike the conventional PW laser welding method, it is possible to prevent the occurrence of a section in which laser oscillation is completely off.

Specifically, referring to the portion indicated by the arrow in (a) of FIG. 2, the laser irradiation unit 100 may irradiate the welding portion W with a laser of peak output according to the control of the laser output control unit 200. Accordingly, the welded portion W may melt and change from a solid state to a liquid state. At this time, a key hole K may be created in the welded portion W, as shown in (a) of FIG. 3.

In addition, referring to the portion indicated by the arrow in (b) of FIG. 2, according to the control of the laser output control unit 200, the laser irradiation unit 100 may irradiate the laser at the base output to the welding portion W. In this way, by irradiating the welded portion W with a base-output laser having a relatively lower output than the peak output, the welded portion W can be prevented from changing from the liquid state back to the solid state.

At this time, additional penetration may not occur in the welded portion W, as shown in (b) of FIG. 3. This will be explained in more detail in the related description below.

And, referring to the portion indicated by the arrow in (c) of FIG. 2, according to the control of the laser output control unit 200, the laser irradiation unit 100 may irradiate the laser at the peak output to the welding portion W again. At this time, since the liquid state of the welded portion W is maintained by laser irradiation of the base output in (b) of FIG. 2, when irradiated with the laser of the peak output as shown in (c) of FIG. 2, the welded portion (W) The key hole (K) can be created more easily. Meanwhile, as shown in (c) of FIG. 3, a key hole (K) may be formed in the welded portion (W) to at least partially overlap the key hole (K) created in (a) of FIG. 3.

According to this implementation configuration, compared to the prior art, excessive accumulation of heat energy input in the welding area (W) is prevented and welding defects are minimized, and the liquid state of the welding area (W) is maintained during the welding process to increase the laser absorption rate of the welding area (W). As a result, the same welding speed and welding productivity can be maintained compared to before.

Referring again to FIG. 2 , the laser output control unit 200 may control the laser irradiation unit 100 to alternately irradiate the laser at peak output and the laser at base output to the welding portion W.

Specifically, the laser irradiation unit 100 may alternately and continuously irradiate the laser at peak output and the laser at base output to the welding portion W under the control of the laser output control unit 200.

Accordingly, while injecting less energy into the welding area W than before, there is no section in which laser irradiation is turned off, so that the liquid state in the welding area W during the welding process can be maintained more reliably.

Figure 7 is a diagram showing simulation results for the boundary values of heat conduction welding and keyhole welding.

Referring to FIG. 7, in the welding device 10 of the present invention, a laser with peak output may have an output capable of forming a key hole (K) in the welding portion (W). Additionally, a laser with a base output may have an output that does not cause penetration in the weld zone W. In other words, the base output laser may have an output level that hardly creates a penetration depth in the welding area W, as shown in FIG. 7 . Accordingly, the base output laser may have an output that hardly creates a penetration depth in the weld zone (W), as shown in FIG. 7, and therefore can be said to have an output that does not create penetration in the weld zone (W). Meanwhile, when the output of the laser irradiated from the laser irradiation unit 100 is less than the output value at which the key hole K is formed, the welding portion W may be welded in the form of heat conduction welding.

As an example, the peak output of the welding device 10 of the present invention may be set to 2.2 kW/mm ² or more. In the case of the peak output value, it may be the minimum value at which the key hole (K) can be formed in the welded portion (W) containing aluminum. Additionally, the base output of the welding device 10 of the present invention can be set within a range of approximately 0.92 kW/mm ² to 1.42 kW/mm ² .

That is, in the welding device 10 of the present invention, in the section where the base output laser is irradiated to the weld area W, the weld area W is formed only with a low output base output laser in which penetration of the weld area W is not formed. It can be maintained in a liquid state. This shows in Figure 7 a laser with a base power (e.g., a power range of 0.92 kW/mm ² to 1.42 kW/mm ² ). It can be confirmed that when the welded portion W is irradiated, the penetration depth of the welded portion W does not occur or the penetration depth of the welded portion W is very small.

Therefore, the penetration depth in the key hole K formed in the laser irradiation section of FIG. 3(c) may be approximately the same as the penetration depth in the key hole K formed in the laser irradiation section of FIG. 3(a). there is.

According to this implementation configuration, the same welding speed as compared to the prior art is achieved by alternately irradiating the laser at peak power and the laser at base output to the weld area W, but in the section where the laser at base power is irradiated to the weld area W, the weld area W ), it is possible to prevent excessive penetration in a specific area of the weld (W) by preventing penetration from forming. Accordingly, welding defects due to melting can be minimized.

In particular, a laser with a base output may have an output capable of maintaining the welding portion W in a liquid state.

In other words, the base output laser may have a minimum output capable of maintaining the weld area W in a liquid state during the process of alternately irradiating the peak power laser and the base output laser to the weld area W.

FIG. 8 is a diagram illustrating a change in the pulse width of a laser controlled by the laser output control unit 200 provided in the welding apparatus 10 of FIG. 1. At this time, (a) in FIG. 8 shows the state before the pulse width of the base output laser is adjusted, and (b) in FIG. 8 shows the state after the pulse width of the base output laser is adjusted.

Referring to FIG. 8, the laser output control unit 200 of the welding device 10 of the present invention may be configured to control the pulse width of the laser at the base output.

In one embodiment of the present invention, when the welding portion W includes a material that reacts more sensitively to the laser (e.g., a metal material with a lower melting point than aluminum, etc.), the illustrated output range (0.92 kW/mm ² to 1.42 In a section where a laser with a base output of kW/mm ² (output range) is irradiated to the welded portion (W), penetration may occur in the welded portion (W).

At this time, the laser output control unit 200 adjusts the pulse width of the base output laser according to the characteristics of the weld area W, thereby penetrating into the weld area W in the section where the base output laser is irradiated to the weld area W. This can be prevented from occurring. Illustratively, when the welding portion W includes a material that reacts more sensitively to the laser, the laser output control unit 200 controls the laser output level as indicated by the arrow and shaded portion in (b) of FIG. 8. The pulse width can be adjusted to become smaller.

According to this implementation configuration, excessive penetration in a specific area of the weld zone (W) can be prevented by controlling the pulse width of the base output laser according to the characteristics of the weld zone (W). Accordingly, welding defects due to melting can be minimized.

FIG. 9 is a diagram illustrating a change in the pulse frequency of a laser by control of the laser output control unit 200 provided in the welding apparatus 10 of FIG. 1. At this time, (a) in FIG. 9 shows the state before the pulse frequency of the base output laser is adjusted, and (b) in FIG. 9 shows the state after the pulse frequency of the base output laser is adjusted.

Referring to FIG. 9, the laser output control unit 200 may be configured to control the pulse frequency of the laser at the base output.

As described above, the laser irradiation unit 100 forms two or more key holes K overlapping with respect to one welding line in the welding area W under the control of the laser output control unit 200, as shown in FIG. 3. As much as possible, a laser with peak power and a laser with base power can be irradiated.

In the welding device 10 of the present invention, when adjusting the pulse frequency of the base output laser, the overlap area between at least two key holes (K) in the welding portion (W) may be changed. At this time, the laser irradiation unit 100 alternately radiates a laser of peak power and a laser of base power to the welding area (W). When adjusting the pulse frequency of the base output laser, the pulse frequency of the peak output laser may also be adjusted.

Exemplarily, the laser output control unit 200 may adjust the pulse frequency of the base output to increase as shown in (b) of FIG. 9. At this time, the pulse frequency of the peak output laser may also be adjusted to increase.

According to this implementation configuration, when the pulse frequency of the base output laser is increased, the overlapping area of the key hole (K) in the weld zone (W) can be increased, so welding in the weld zone (W) can be performed more stably. . Additionally, when the welding area in the welding area W is small, the pulse frequency of the base output laser can be increased to increase the welding speed while minimizing excessive accumulation of heat input energy in the welding area W.

FIG. 10 is a diagram illustrating a change in laser output by control of the laser output control unit 200 provided in the welding apparatus 10 of FIG. 1. At this time, (a) in Figure 10 shows the state before the output of the base-output laser is adjusted, and (b) in Figure 10 shows the state after the output of the base-output laser is adjusted.

Referring to FIG. 10, the laser output control unit 200 may be configured to control the output of the laser at the base output.

In one embodiment of the present invention, when the welding portion W includes a material that reacts more sensitively to the laser (e.g., a metal material with a lower melting point than aluminum, etc.), the illustrated output range (0.92 kW/mm ² to 1.42 In a section where a laser with a base output of kW/mm ² (output range) is irradiated to the welded portion (W), penetration may occur in the welded portion (W).

At this time, the laser output control unit 200 adjusts the output of the base-output laser according to the characteristics of the welding area W, thereby preventing penetration into the welding area W in the section where the base-output laser is irradiated to the welding area W. You can prevent it from happening. Illustratively, when the welding portion W includes a material that reacts more sensitively to the laser, the laser output control unit 200 controls the laser output level as indicated by the arrow and shaded portion in (b) of FIG. 10. The output can be adjusted to be smaller.

According to this implementation configuration, Excessive penetration in a specific area of the weld zone (W) can be prevented by controlling the output of the base laser according to the characteristics of the weld zone (W). Accordingly, welding defects due to melting can be minimized.

Referring to FIG. 1, the welding device 10 of the present invention may further include an inspection unit 300.

The inspection unit 300 may be configured to inspect the welding state of the welded portion W after completion of welding by the welding device 10. As an example, the inspection unit 300 may include a processor, a camera (eg, an infrared camera), an X-ray transmission device, etc. And, the inspection unit 300 may be provided on the outer surface of the housing (H) described above.

For example, when the inspection unit 300 detects that excessive penetration has occurred in a specific area of the welding area (W) after completion of welding by the welding device 10, the inspection unit 300 transmits this welding state inspection information to the laser output control unit. It can be sent to (200).

At this time, the laser output control unit 200 may be configured to control the output of the base laser according to the welding state inspection information provided from the inspection unit 300. That is, the laser output control unit 200 performs the next welding process by the welding device 10. The output of the base laser can be controlled to prevent welding defects from occurring.

Meanwhile, the laser output control unit 200 may be configured to control the pulse width or pulse frequency of the base output laser according to the welding state inspection information provided from the inspection unit 300.

Meanwhile, the inspection unit 300 may be configured to inspect the welding state at the welding portion W during welding by the welding device 10.

For example, when the inspection unit 300 detects that excessive penetration has occurred in a specific area of the welding area (W) during welding by the welding device 10, the inspection unit 300 sends this welding state inspection information to the laser output control unit ( 200).

At this time, the laser output control unit 200 may be configured to control the output of the base laser according to the welding state inspection information provided from the inspection unit 300. That is, the laser output control unit 200 can control the output of the laser at the base output so that welding defects no longer occur during welding by the welding device 10.

Meanwhile, the laser output control unit 200 may be configured to control the pulse width or pulse frequency of the base output laser according to the welding state inspection information provided from the inspection unit 300.

11 and 12 are diagrams showing another control method of a laser using the welding device 10 of the present invention.

In the case of the present invention, a laser of base power is irradiated to the welded portion W between sections in which the laser of peak power is irradiated to the welded portion W, so the liquid state of the welded portion W can be maintained throughout the entire welding process. .

At this time, in the case of the welding device 10 of the present invention, as shown in FIG. 11, the laser output control unit 200 operates the laser irradiation unit so that the output of the peak output laser and the base output laser decreases as time passes. Laser irradiation can also be controlled by (100). Alternatively, in the case of the welding device 10 of the present invention, as shown in FIG. 12, the laser output control unit 200 operates the laser irradiation unit so that the pulse widths of the laser at peak output and the laser at base output decrease as time passes. Laser irradiation can also be controlled by (100). In addition, in the case of the welding device 10 of the present invention, the laser output control unit 200 controls the laser irradiation unit 100 so that both the output and pulse width of the peak output laser and the base output laser decrease as time passes. Laser irradiation can also be controlled.

In this way, in the case of the welding device 10 of the present invention, even if the irradiation of the laser is controlled as shown in FIG. 11 or 12, the liquid state of the welded portion W is caused by irradiation of the base output laser to the welded portion W. It can be maintained. Therefore, welding defects can be minimized while inputting less energy into the welding area W than before.

Hereinafter, in order to show the effects of the welding device 10 of the present invention in more detail, it will be described in more detail through examples and comparative examples. However, the embodiments according to the present invention may be modified into various other forms, and the scope of the present invention should not be construed as being limited to the embodiments described in detail below.

(Examples 1 to 10)

As shown in FIG. 1, welding was performed on the welded portion W using a welding device (model name: laser (Trumpf TruDiode 4006), optical system (Trumpf BEO D70 0°K200 F200 T950)).

At this time, in all examples, the welding part (W) was made of pure aluminum, and the Top/Bottom of the extruded mono-frame AL6063 had a thickness of 2.0mm, and the side had a thickness of 3.2mm. . In addition, Endplate ADC12, manufactured by die-cast, was processed to correspond to the thickness of each side of the monoframe. And, the total length of the welded portion (W) was set to 562 mm on one side and 1124 mm on both sides. And, the overall width of the welded portion (W) was set to a bead width of 2.0 to 4.0 mm. Additionally, the length of one welding line was 80mm on the top side, 96mm on the side side, and 210mm on the bottom side. And, the welded portion W was used as a joint between the components of the battery module (not shown). Specifically, the welded portion W was a joint between a module case (not shown) and an end plate (not shown).

In addition, as shown in FIG. 2, the welding device alternately and continuously radiates a laser at peak power and a laser at base power to the weld area W. At this time, the peak output of the laser was set to 3300W±200W in the 2.0mm thick section on the Top/Bottom side, and 3600W±200W in the 3.2mm thick section on the side side. The base output laser output was set to 1200W±200W in the 2.0mm thick section on the Top/Bottom side, and 2000W±200W in the 3.2mm thick section on the side. In addition, the number of welding in one welding line was 1, the welding speed for one welding line was 60 mm/sec, the total welding length was 1124 mm, and the total welding time was 18.7 seconds. In addition, the number of welding times for one welding area (W) including at least one welding line is 1 time, and the total welding time for one welding area (W) is 1.33 seconds in the 80mm section on the top side and 1.33 seconds in the 96mm section on the side side. It was set at 1.6 seconds, and 3.5 seconds at the 210mm section on the bottom side. Additionally, the irradiation time of the laser at peak power and the irradiation time of the laser at base power were set at the same ratio.

In addition, as shown in FIG. 3, the welding device alternately irradiates a laser at peak output and a laser at base output so that two or more key holes K can be formed overlapping with respect to one welding line.

According to an embodiment of the present invention, welding was performed in the same manner as above to form a welded portion (W), and the welding quality of the formed welded portion (W) was measured. More specifically, a number of samples were manufactured in the same manner as above for each week over a period of 10 weeks, the number of samples in which welding defects occurred with respect to the welded portion (W) of the manufactured samples was counted, and the counted results were calculated. It is listed in Table 1. That is, Table 1 shows experimental data over a total of 10 weeks, and each week is indicated as Examples 1 to 10, For each example, it shows the number of battery modules produced in one week and the number of welding defects (e.g., melting) in the welded portion W included in the produced battery modules, that is, each sample.

(Comparative example)

Meanwhile, in the case of the comparative example, welding was performed by irradiating only the laser at peak output to the welding area using the conventional PW (Pulse Wave) laser welding method shown in FIG. 5. At this time, the welded part was made of pure aluminum, and the Top/Bottom of the extruded mono-frame AL6063 had a thickness of 2.0mm, and the side had a thickness of 3.2mm. In addition, Endplate ADC12, manufactured by die-cast, was processed to correspond to the thickness of each side of the monoframe. And, the total length of the welded part was set to 562mm on one side and 1124mm on both sides. And, the overall width of the welded area was set to a bead width of 2.0 to 4.0 mm. Additionally, the length of one welding line was 80mm on the top side, 96mm on the side side, and 210mm on the bottom side. And, the welding part was a joining part between the components of the battery module (not shown). Specifically, the welded portion was a joint portion between the module case (not shown) and the end plate (not shown).

In addition, the peak output of the laser was set to 3300W±200W in the 2.0mm thick section on the Top/Bottom side, and 3600W±200W in the 3.2mm thick section on the side side. In addition, the number of welding in one welding line was 1, the welding speed for one welding line was 10 mm/sec, the total welding length was 1124 mm, and the total welding time was 112.4 seconds. In addition, the number of welding times for one welding section including at least one welding line is 1 time, and the total welding time for one welding section is 8 seconds in the 80mm section on the top side, 9.6 seconds in the 96mm section on the side, and 210mm on the bottom side. The section was set at 21 seconds. In addition, the irradiation time of the peak output laser and the time in the section where the laser is not irradiated were set at the same ratio.

Battery module production per week (units) weld defects
Number of occurrences (times) Example 1 2,560 One Example 2 15,285 6 Example 3 16,987 7 Example 4 20,200 0 Example 5 20,416 7 Example 6 21,421 8 Example 7 30,562 9 Example 8 28,093 6 Example 9 34,220 9 Example 10 23,889 3 Comparative example 10,040 27

Referring to the results in Table 1, it can be seen that in Examples 1 to 10, the welding defect occurrence rate was very low, whereas in the comparative example, the welding defect occurrence rate was significantly higher compared to Examples 1 to 10. You can.

Looking more specifically, in Example 1, 2,560 battery modules were produced in one week, and in this case, the number of welding defects in the welding area (W) was 1. In this case, the welding defect occurrence rate is only approximately 0.04%.

In Example 2, 15,285 battery modules were produced in one week, and in this case, the number of welding defects in the welding area (W) was 6. In this case, the welding defect occurrence rate is only approximately 0.04%.

In Example 3, 16,987 battery modules were produced in one week, and in this case, the number of welding defects in the welding area (W) was 7. In this case, the welding defect occurrence rate is only approximately 0.04%.

In Example 4, 20,200 battery modules were produced in one week, and in this case, the number of welding defects in the weld area (W) was 0.

In Example 5, 20,416 battery modules were produced in one week, and in this case, the number of welding defects in the welding area (W) was 7. In this case, the welding defect occurrence rate is only approximately 0.03%.

In Example 6, 20,421 battery modules were produced in one week, and in this case, the number of welding defects in the welding area (W) was 8. In this case, the welding defect occurrence rate is only approximately 0.04%.

In Example 7, 30,562 battery modules were produced in one week, and in this case, the number of welding defects in the welding area (W) was 9. In this case, the welding defect occurrence rate is only approximately 0.03%.

In Example 8, 28,093 battery modules were produced in one week, and in this case, the number of welding defects in the weld area (W) was 6. In this case, the welding defect occurrence rate is only approximately 0.02%.

In Example 9, 34,220 battery modules were produced in one week, and in this case, the number of welding defects in the welding area (W) was 9. In this case, the welding defect occurrence rate is only approximately 0.03%.

In Example 10, 23,889 battery modules were produced in one week, and in this case, the number of welding defects in the welding area (W) was 3. In this case, the welding defect occurrence rate is only approximately 0.01%.

That is, looking at Table 1 below, it was found that the number of welding defects in the welding area (W) rarely occurred (less than 10 times) regardless of the production volume of the battery module for each example.

In particular, when producing 2,560 products at week 22 of Example 1, one welding defect occurred, but when producing 30,562 products at week 28 of Example 7, product production was increased by more than 10 times compared to Example 1. It was found that only 9 welding defects occurred.

On the other hand, referring to Table 1 above, in the case of the comparative example, the number of welding defects occurring in the weld zone for battery modules produced for one week during the mass production process of the battery module is shown.

Specifically, in the case of the comparative example, 10,040 products were produced in one week, and in this case, the number of welding defects in the weld zone was 27 times. In this case, the weld defect occurrence rate is approximately 0.27%. In addition, this welding defect occurrence rate can be said to be significantly higher than the average 0.028% of the welding defect occurrence rate in Examples 1 to 10.

In particular, in the case of the comparative example, it was found that more welding defects occurred than in Example 1, which was approximately 20% of the number of products produced in the comparative example.

In addition, in the case of the comparative example, it was found that more welding defects occurred than in Example 2, which produced approximately 5,000 more products than the number of products produced in the comparative example.

As can be seen from these results, in the case of the welding device 10 according to an embodiment of the present invention, welding defects in the weld zone W can be minimized compared to the conventional laser welding method.

The battery manufacturing device according to the present invention may include the welding device 10 described above. In addition, the battery manufacturing device according to the present invention may further include various known devices for manufacturing battery modules (eg, a battery module inspection device) in addition to the welding device 10 described above.

The automobile manufacturing device according to the present invention may include the welding device 10 described above. In addition, the automobile manufacturing device according to the present invention may further include various known devices for manufacturing automobiles (eg, automobile inspection devices) in addition to the welding device 10 described above.

As described above, although the present invention has been described with limited examples and drawings, the present invention is not limited thereto, and the technical idea of the present invention and the following will be understood by those skilled in the art to which the present invention pertains. Of course, various modifications and variations are possible within the scope of equivalence of the patent claims to be described.

Meanwhile, in the present invention, terms indicating directions such as up, down, left, right, front, and back are used, but these terms are only for convenience of explanation and may vary depending on the location of the target object or the location of the observer. It is obvious to those skilled in the art that this can be done.

10: welding device
100: Laser irradiation unit
200: Laser output control unit
300: Inspection department
W: welding area
K: key hole

Claims (13)

a laser irradiation unit configured to irradiate a laser; and
The laser irradiation unit includes a laser output control unit configured to control the peak output laser and the base output laser to be irradiated to the welding area. A welding device that does. According to clause 1,
The laser output control unit,
A welding device, characterized in that it is configured to control the laser irradiation unit so that the welding unit maintains a liquid state. According to clause 1,
The laser output control unit,
A welding device, wherein the laser irradiation unit is configured to control the laser irradiation unit to alternately irradiate the laser at the peak output and the laser at the base output to the welding area. According to clause 1,
The laser of the peak output is,
Has an output capable of forming a key hole in the weld part,
The base output laser is,
A welding device characterized in that it has an output that prevents penetration from being formed in the welded portion. According to clause 4,
The base output laser is,
A welding device, characterized in that the welding unit has an output capable of maintaining a liquid state. According to clause 1,
The laser output control unit,
Welding device, characterized in that it is configured to control the pulse width of the laser of the base output. According to clause 1,
The laser output control unit,
Welding device, characterized in that it is configured to control the pulse frequency of the laser of the base output. According to clause 1,
The laser output control unit,
Welding device, characterized in that it is configured to control the output of the laser at the base output. According to clause 1,
The welding device is,
Further comprising an inspection unit configured to inspect a welding state in the welded portion after completion of welding by the welding device,
The laser output control unit,
Welding device, characterized in that it is configured to control the output of the base output laser according to the welding state inspection information provided from the inspection unit. According to clause 1,
The welding device is,
Further comprising an inspection unit configured to inspect a welding state in the weld portion during welding by the welding device,
The laser output control unit,
Welding device, characterized in that it is configured to control the output of the base output laser according to the welding state inspection information provided from the inspection unit. Irradiating a laser at peak output to the weld area; and
A welding method comprising the step of irradiating a laser of base output to the welding portion. A battery manufacturing device comprising the welding device according to any one of claims 1 to 10. An automobile manufacturing device comprising the welding device according to any one of claims 1 to 10.

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