KR102593180B1 - Laser welding apparatus and control method thereof - Google Patents

Abstract

The present invention discloses a laser welding device and a control method thereof. The laser welding device of the present invention includes an input module that receives welding data; A scanner that moves a laser beam through an internal galvano mirror and irradiates it to the welding position; A shielding gas nozzle mounted on the stage to spray shielding gas; A stage driving module that drives the stage to move the shielding gas nozzle to the welding position; Memory; and a processor operatively coupled to the input module, scanner, stage drive module, and memory; wherein the processor drives an executable program to calculate the welding position based on welding data input from the input module. After setting the speed profile of the stage, the stage driving module is driven according to the speed profile to move the shielding gas nozzle, and the galvanometer of the scanner is driven based on the welding position to irradiate the laser beam.

Description

Laser welding device and its control method {LASER WELDING APPARATUS AND CONTROL METHOD THEREOF}

The present invention relates to a laser welding device and its control method. More specifically, the shielding gas nozzle mounted on the stage is synchronized and moved coaxially with the scanner type laser beam, so that the shielding gas nozzle is adjusted according to the welding position of the scanner type. This relates to a laser welding device that can purge shielding gas while moving and a method of controlling the same.

Recently, as the problem of air pollution caused by exhaust gases from fossil fuel vehicles has emerged, the spread of electric vehicles and hybrid vehicles has been expanding. These electric vehicles and hybrid vehicles (hereinafter collectively referred to as 'electric vehicles') contain lithium. A battery module composed of secondary batteries such as ion batteries, lithium polymer batteries, nickel cadmium batteries, nickel hydrogen batteries, and nickel zinc batteries is built in, and electrical energy is supplied to the engine (motor) through the battery module to drive it.

As such, a battery module built into an electric vehicle generally consists of a plurality of battery cells and a module case accommodating the plurality of battery cells, and the module case includes a case and a plurality of cells accommodating at least one battery cell inside the case. It is composed of a cartridge, and the electrode leads of the two battery cells that are accommodated in the module case and face each other are welded to each other using a laser welding device, etc. outside the module case to be electrically connected.

In the industrial field, laser beams, which have excellent effects in terms of cost reduction, factory automation, and quality improvement, are being applied to cutting, welding, and heat treatment of metal materials.

Welding using a laser is a welding technology used to join metals and various materials. Due to its high energy density, it only has a thermal effect on the minimum area of the joint, minimizing deformation of the base material and producing relatively low heat compared to other welding technologies. It is widely used in welding in a variety of fields because it allows welding with a high aspect ratio through input.

In particular, in the secondary battery field, it is used in various applications such as can cap welding, foil welding, tab-pole welding, pinhole seal welding, terminal welding, and vent welding.

The background technology of the present invention is disclosed in Republic of Korea Patent Publication No. 10-2369375 (2022.03.02 notice, Vehicle battery laser welding device using a displacement sensor).

Representative welding methods using such lasers include scanner type and gun type depending on the method of transmitting the laser beam from the laser source to the base material.

Here, the scanner type method allows welding by moving the scanner to the working position using a multi-axis robot, etc., and then moving the laser beam to the desired location through the internal galvano mirror.

The advantage of the scanner type is that there is no need to move the welding base material and the scanner, enabling dynamic welding work at high speeds, realizing welding trajectories in small and fine sub-micro units, as well as being able to irradiate the laser beam even in physically narrow spaces. There is.

Additionally, a disadvantage of the scanner type is that it sprays shielding gas through a fixed nozzle or air knife, making it difficult to uniformly purge the shielding gas when the welding length is long or a large area is welded.

Meanwhile, in the gun type, when a laser beam is incident on the gun head, it is focused on the base material by a focusing lens and welding is performed by physically moving the base material or gun head according to the welding direction. At this time, shielding gas purging is performed through a nozzle formed coaxially with the laser beam.

The advantage of the gun type is that shielding gas purging is possible coaxially with the laser beam irradiation, and even during large-area welding, the laser beam and shielding gas nozzle are coaxial, so uniform shielding gas purging is possible, and various types of nozzles can be replaced. Smooth shielding gas purge is possible through .

Meanwhile, the disadvantage of the gun type is that the head itself must physically move, which causes acceleration/deceleration and tremors due to the weight, which increases the specifications of the handling orthogonal robot and causes loss of space. There is a disadvantage that it is difficult to implement the welded shape.

During laser-based welding, shielding gas purging, which sprays an inert gas such as nitrogen or argon as a shielding gas, can protect the surface of the welded area from oxidation with the surrounding air and improve the appearance quality. In addition, in the case of laser welding that irradiates high energy to the base material, if plasma is generated beyond the point where the metal melts, the plasma may scatter the laser beam performing welding and deteriorate welding quality. Plasma is generated by purging the shielding gas. It is possible to prevent the deterioration of welding quality by blowing away the fumes generated during welding.

In this way, during laser welding, the scanner type has difficulty purging the shielding gas when welding a large area or the weld shape is not straight, and the gun type not only requires higher specifications of the orthogonal robot and causes loss of space, but also requires high-speed and micro-unit welding. There is a problem that processing of the weld shape is difficult.

The present invention was created to improve the problems described above, and the purpose of the present invention according to one aspect is to synchronize and move the shielding gas nozzle mounted on the stage coaxially with the scanner-type laser beam, thereby maintaining the scanner-type welding position. Accordingly, a laser welding control device and method that can purge shielding gas while moving the shielding gas nozzle are provided.

A laser welding device according to one aspect of the present invention includes an input module that receives welding data; A scanner that moves a laser beam through an internal galvano mirror and irradiates it to the welding position; A shielding gas nozzle mounted on the stage to spray shielding gas; A stage driving module that drives the stage to move the shielding gas nozzle to the welding position; Memory; and a processor operatively coupled to the input module, scanner, stage drive module, and memory; wherein the processor drives an executable program to calculate the welding position based on welding data input from the input module. After setting the speed profile of the stage, the stage driving module is driven according to the speed profile to move the shielding gas nozzle, and the galvanometer of the scanner is driven based on the welding position to irradiate the laser beam.

In the present invention, the processor is characterized in that it drives the scanner by reflecting the driving delay time and acceleration/deceleration time of the stage based on the speed profile.

In the present invention, the stage driving module is characterized by driving the stage based on the XY axis.

In the present invention, the shielding gas nozzle is characterized by forming a through hole through which a laser beam can pass through the center.

A method of controlling a laser welding device according to an aspect of the present invention includes the steps of having a processor receive welding data from an input module; A processor calculating a welding position based on welding data; A step where the processor sets a speed profile of the stage for moving the shielding gas nozzle to the welding position and drives the stage driving module to move the shielding gas nozzle; And a step of the processor driving the galvano mirror of the scanner based on the welding position to irradiate the laser beam.

In the present invention, the step of irradiating a laser beam is characterized in that the processor drives the scanner by reflecting the driving delay time and acceleration/deceleration time of the stage based on the speed profile.

The laser welding device and its control method according to one aspect of the present invention move the shielding gas nozzle mounted on the stage in synchronization with the scanner type laser beam, thereby moving the shielding gas nozzle according to the welding position of the scanner type to provide shielding. Gas can be purged, enabling uniform purging of shielding gas even in a large area, ensuring welding quality and beautiful external shape. In addition to faster welding speed than the gun type and welding of fine bends and fine shapes, it is also possible to use light shielding gas. By moving only the nozzle, the stage can be handled inexpensively and with low specifications.

1 is a block diagram showing a laser welding device according to an embodiment of the present invention.
Figure 2 is an exemplary diagram schematically showing a laser welding device according to an embodiment of the present invention.
Figure 3 is a flowchart for explaining a control method of a laser welding device according to an embodiment of the present invention.

Hereinafter, the laser welding device and its control method according to the present invention will be described with reference to the attached drawings. In this process, the thickness of lines or sizes of components shown in the drawing may be exaggerated for clarity and convenience of explanation. In addition, the terms described below are terms defined in consideration of functions in the present invention, and may vary depending on the intention or custom of the user or operator. Therefore, definitions of these terms should be made based on the content throughout this specification.

FIG. 1 is a block diagram showing a laser welding device according to an embodiment of the present invention, and FIG. 2 is an exemplary diagram schematically showing a laser welding device according to an embodiment of the present invention.

As shown in FIGS. 1 and 2, the laser welding control device may include an input module 10, a scanner 40, a stage driving module 50, a memory 20, and a processor 30.

The input module 10 can receive welding data for laser welding the base material 80.

The scanner 40 can weld by moving the laser beam 42 through the internal galvano mirror 45 and irradiating it to the welding position.

As shown in FIG. 2, the stage driving module 50 is mounted on the stage 60 that can move in the XY axis and can move the shielding gas nozzle 70 for spraying shielding gas to the welding position.

Here, the stage 60 and the stage driving module 50 can be configured as XY orthogonal mobile robots, and the shielding gas nozzle 70 can be moved to the welding position through the XY orthogonal mobile robot.

At this time, it is preferable that the shielding gas nozzle 70 has a through hole 75 formed through the center through which the laser beam 42 can pass.

The memory 20 can store data related to a program for controlling the laser welding control device, and the stored information can be independently selected by the processor 30 as needed.

That is, the memory 20 stores various types of data generated during the execution of an operating system or application (program or applet) for driving the laser welding control device. At this time, the memory 20 refers to a non-volatile storage device that continues to retain stored information even when power is not supplied, and a volatile storage device that requires power to maintain the stored information. Additionally, the memory 20 may perform a function of temporarily or permanently storing data processed by the processor 30.

Here, the memory 20 may include magnetic storage media or flash storage media in addition to volatile storage devices that require power to maintain stored information, but the scope of the present invention is limited thereto. It doesn't work.

The processor 30 is operatively coupled to the input module 10, the scanner 40, the stage driving module 50, and the memory 20 to control the overall operation of the laser welding control device. Various programs stored in (20) can be copied to RAM and executed to perform various operations.

In various embodiments, the processor 30 may be implemented as a digital signal processor (DSP), a microprocessor, or a time controller (TCON) that processes digital signals. However, it is not limited to this. , central processing unit (CPU), micro controller unit (MCU), micro processing unit (MPU), controller, application processor (AP), or communication processor (CP) )), may include one or more of ARM processors, or may be defined by the corresponding term. In addition, the processor 50 may be implemented as a SoC (System on Chip) with a built-in processing algorithm, LSI (large scale integration). Alternatively, it may be implemented in the form of an FPGA (Field Programmable Gate Array).

That is, the processor 30 drives the execution program built into the memory 20, calculates the welding position based on the welding data input from the input module 10, sets the speed profile of the stage 60, and sets the speed profile. The shielding gas nozzle 70 can be moved by driving the stage driving module 50 according to the profile.

In addition, the processor 30 reflects the driving delay time and acceleration/deceleration time of the stage 60 based on the speed profile and drives the galvanomirror 45 of the scanner 40 based on the welding position to generate the laser beam 42. ) can be irradiated to the base material 80 to perform welding.

As described above, according to the laser welding device according to an embodiment of the present invention, the shielding gas nozzle mounted on the stage is moved in synchronization with the scanner type laser beam, so that the shielding gas nozzle is moved according to the welding position of the scanner type. As the shielding gas can be purged while moving, it is possible to purge the shielding gas uniformly even in a large area, ensuring welding quality and an attractive external shape. In addition, it is possible to achieve faster welding speed than the gun type and welding of fine bends and fine shapes. By moving only the light shielding gas nozzle, the stage can be handled inexpensively and with low specifications.

Figure 3 is a flowchart for explaining a control method of a laser welding device according to an embodiment of the present invention.

As shown in FIG. 3, in the control method of the laser welding device according to an embodiment of the present invention, first, the processor receives welding data from the input module (S10).

After receiving the welding data in step S10, the processor calculates the welding position based on the welding data (S20).

After calculating the welding position in step S20, the processor 30 sets the speed profile of the stage 60 to move the shielding gas nozzle 70 to the welding position (S30).

After setting the speed profile of the stage 60 in step S30, the processor 30 drives the stage driving module 50 according to the speed profile to move the shielding gas nozzle 70 (S40).

In addition, after setting the speed profile of the stage 60 in step S30, the processor 30 drives the galvanometer mirror 45 of the scanner 40 based on the welding position to direct the laser beam 42 to the base material 80. Irradiate and perform welding (S50).

At this time, the processor 30 reflects the driving delay time and acceleration/deceleration time of the stage 60 based on the speed profile and drives the galvanometer mirror 45 of the scanner 40 based on the welding position to generate the laser beam 42. Welding can be performed by irradiating the base material 80.

As described above, according to the control method of the laser welding device according to the embodiment of the present invention, the shielding gas nozzle mounted on the stage is synchronized and moved coaxially with the scanner type laser beam, thereby providing shielding according to the welding position of the scanner type. Shielding gas can be purged as the gas nozzle moves, enabling uniform shielding gas purge even in a large area, ensuring welding quality and beautiful external shape. Faster welding speed than the gun type and welding of fine bends and fine shapes. Not only is this possible, but the stage can be handled inexpensively and with low specifications by moving only the light shielding gas nozzle.

Implementations described herein may be implemented, for example, as a method or process, device, software program, data stream, or signal. Although discussed only in the context of a single form of implementation (eg, only as a method), implementations of the features discussed may also be implemented in other forms (eg, devices or programs). The device may be implemented with appropriate hardware, software, firmware, etc. The method may be implemented in a device such as a processor, which generally refers to a processing device that includes a computer, microprocessor, integrated circuit, or programmable logic device. Processors also include communication devices such as computers, cell phones, portable/personal digital assistants (“PDAs”) and other devices that facilitate communication of information between end-users.

The present invention has been described with reference to the embodiments shown in the drawings, but these are merely exemplary, and those skilled in the art will recognize that various modifications and other equivalent embodiments are possible therefrom. You will understand.

Therefore, the true technical protection scope of the present invention should be determined by the claims below.

10: input module 20: memory
30: Processor 40: Scanner
42: Laser beam 45: Galvano mirror
50: Stage driving module 60: Stage
70: Shielding gas nozzle 80: Base material

Claims (6)

An input module that receives welding data;
A scanner that moves a laser beam through an internal galvano mirror and irradiates it to the welding position;
A shielding gas nozzle mounted on the stage to spray shielding gas;
a stage driving module that drives the stage to move the shielding gas nozzle to the welding position;
Memory; and
Including a processor operatively coupled to the input module, the scanner, the stage driving module, and the memory,
The processor drives an execution program to calculate the welding position based on the welding data input from the input module, sets a speed profile of the stage, and then drives the stage driving module according to the speed profile to provide the shielding. Move the gas nozzle and drive the galvanometer of the scanner based on the welding position to irradiate the laser beam,
A laser welding device, characterized in that the scanner is driven by reflecting the driving delay time and acceleration/deceleration time of the stage based on the speed profile.
delete The laser welding device according to claim 1, wherein the stage driving module drives the stage based on the XY axis.
The laser welding device according to claim 1, wherein the shielding gas nozzle has a through hole formed in the center through which the laser beam can pass.
A processor receiving welding data from an input module;
The processor calculating a welding position based on the welding data;
the processor setting a speed profile of a stage for moving the shielding gas nozzle to the welding position and driving a stage driving module to move the shielding gas nozzle; and
Including the step of the processor driving a galvano mirror of the scanner to irradiate a laser beam based on the welding position,
The step of irradiating the laser beam is,
A method of controlling a laser welding device, wherein the processor drives the scanner by reflecting the driving delay time and acceleration/deceleration time of the stage based on the speed profile.
delete

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