CN-121988879-A - Laser welding process, laser welding controller and system

CN121988879ACN 121988879 ACN121988879 ACN 121988879ACN-121988879-A

Abstract

The application provides a laser welding process, a laser welding controller and a system, wherein the process comprises the steps of conveying a battery module to a preset station by means of a tray, primarily positioning a battery pole, assembling a CCS and the battery module, conveying a combined structure of the CCS and the battery module into a welding room, sending a starting instruction to a welding device by a general control system, secondarily positioning the battery pole by a vision system, dynamically correcting a welding track by using a galvanometer control system through data support of the vision system, issuing a welding instruction, and controlling laser output power in a segmented mode according to a preset time node, namely, gradually increasing the power from zero to the preset welding power, then controlling the power to be constant, and finally controlling the power to be gradually reduced to zero. According to the laser welding process, the laser welding controller and the laser welding system, the laser welding power is slowly increased and slowly decreased, so that the welding quality, the welding reliability and the equipment stability are finally improved.

Inventors

Ke Zunjun
PENG HEYI
HE SHUAIQIANG
CHEN MING

Assignees

海希储能科技(山东)有限公司

Dates

Publication Date: 20260508
Application Date: 20260326

Claims (10)

1. The laser welding process is applied to welding the square battery pole and the CCS and is characterized by comprising the following steps of: conveying the tray loaded with the battery modules to a preset station; the battery pole in the battery module is positioned for the first time by an addressing machine; mounting the CCS on a preset position of the battery module; controlling a battery module provided with a CCS to enter a welding room; After the tray reaches the welding position in the welding room, the master control system sends a starting instruction to the welding device; the vision system of the welding device performs secondary positioning on the battery pole to acquire deviation data of the battery pole relative to a reference position; The vision system sends deviation data to the galvanometer control system, and the galvanometer control system dynamically corrects the welding track according to the deviation data and issues a welding instruction comprising welding coordinates, the corrected welding track and a laser starting signal; After receiving the laser start instruction, the laser controller controls the laser output power in a segmented mode according to a preset time node, firstly controls the laser output power to slowly increase from zero to preset welding power, then controls the laser to weld with constant power, and finally controls the laser output power to slowly decrease from the preset welding power to zero.
2. The laser welding process of claim 1, wherein when the galvanometer control system issues a welding command, the laser beam is controlled to deflect to the vicinity of the center point of the pole, and the laser beam is driven to scan along the corrected welding track at a constant speed, so as to form a spiral point track.
3. The laser welding process according to claim 1 or 2, wherein the running speed of the welding track is adjusted so that the point in time when the track scanning is completed coincides with the point in time when the laser output power gradually drops to zero when the galvanometer control system issues a welding command.
4. A laser welding controller, wherein the laser welding controller is configured to: presetting laser output working power, a slow-rise track, a single-period duration and a slow-fall track; Responding to a laser starting instruction, controlling the laser output power proportion to rise from 0% to 100% according to the gradual rise track, and operating the single period duration constantly according to the laser output working power; And controlling the laser output power ratio to drop from 100% to 0% according to the slow drop trajectory in response to reaching the single period duration.
5. A laser welding control system comprising the laser welding controller of claim 4.
6. The laser welding control system of claim 5, wherein the laser welding control system further comprises: a waveform control card electrically connected with the laser welding controller, and The galvanometer controller is electrically connected with the laser welding controller and is used for sending a laser starting signal to the laser welding controller; The laser welding controller is configured to: responding to the laser starting signal, controlling laser output power through the waveform control card, rising to the laser output working power according to the slow-rising track, and constantly operating the single-period duration according to the laser output working power; And responding to the single period time, controlling the laser output power by the waveform control card, and reducing to zero according to the slow-down track.
7. The laser welding control system of claim 6, wherein the laser welding control system further comprises: The galvanometer is used for adjusting the laser beam according to a welding track preset by the galvanometer controller and is electrically connected with the galvanometer controller; The laser welding controller is configured to: controlling the vibrating mirror to start in response to welding coordinates issued by the vision system so as to deflect the laser beam to the vicinity of the center point of the pole; responding to a welding track preset by the galvanometer controller, and sending a laser starting instruction while performing welding action; and controlling the galvanometer to close when or after the laser output power drops to zero.
8. The laser welding control system of claim 7, wherein the laser welding controller is further configured to: And responding to the laser starting signal, controlling the vibrating mirror to do circular motion, and simultaneously enabling the light spot on the welding track to form a spiral point with the inner diameter of 8mm and the outer diameter of 12-14 mm.
9. The laser welding control system of claim 7 or 8, wherein the laser welding controller is further configured to: According to a preset welding chart, in the process that the vibrating mirror drives the laser beam to scan along the spiral track, when the laser beam scans to the initial overlapping area or the initial position of the inner ring of the spiral track, controlling the laser output power to execute the gradual lifting track; And controlling the laser output power to execute the slow-descent track when the laser beam scans to the ending overlapping area or the outer ring ending position of the spiral track in the process of driving the laser beam to scan along the spiral track by the vibrating mirror according to a preset welding pattern file.
10. The laser welding control system of claim 9, wherein the slow-rise trajectory corresponds to a duration of 20ms and/or the slow-fall trajectory corresponds to a duration of 50ms.

Description

Laser welding process, laser welding controller and system Technical Field The application belongs to the technical field of laser welding, and particularly relates to a laser welding process, a laser welding controller and a laser welding system. Background The laser welding is a high-energy beam welding technology, and the material is locally melted and forms metallurgical bonding by a laser beam with high energy density, so that the method has the advantages of concentrated energy, small heat affected zone, high welding speed, small deformation, easiness in automation and the like. In the field of power battery manufacturing, laser welding is widely used for connection between a battery post and a connecting piece (such as CCS, cells Contact System), and the welding quality of the connecting point is directly related to the conductivity, structural stability and service life of the battery module. In the prior art, aiming at the laser welding of a battery pole and a CCS, a high-power laser is generally adopted to work together with a galvanometer scanning system. In the welding process, the position of the pole is identified and positioned through a vision system, and the laser beam is guided to finish welding along a preset track. The inventors found that quality defects still easily occur in the arcing and arc-receiving stages during the high-power laser welding process. Specifically, at the moment of arcing, the polar column and the CCS material are in a cold state, the laser energy needs to heat the material to a melting point firstly, a molten pool is unstable in the initial stage, partial unfused or insufficient penetration virtual welding phenomenon is easily caused if the energy input is insufficient or the heating is uneven, and during the arcing stage, the molten pool is rapidly cooled and contracted along with the removal of a laser beam, and shrinkage cavities or microcracks are easily formed at the arc pit if the liquid metal is not replenished timely. These problems directly affect the conductivity and mechanical strength of the connection point between the pole and CCS, and become key factors for restricting the consistency and reliability of the welding quality of the battery module. Disclosure of Invention The embodiment of the application provides a laser welding process, a laser welding controller and a laser welding system, which aim to solve the problems that when the conventional square battery pole and a CCS are welded by laser, the quality defects such as virtual welding, cracks and the like are easy to occur at the arc starting and arc receiving positions and the welding pressure nozzle is easy to damage. In order to achieve the above purpose, the application adopts the following technical scheme: The laser welding process is applied to welding the square battery pole and the CCS, and comprises the following steps: conveying the tray loaded with the battery modules to a preset station; the battery pole in the battery module is positioned for the first time by an addressing machine; mounting the CCS on a preset position of the battery module; controlling a battery module provided with a CCS to enter a welding room; After the tray reaches the welding position in the welding room, the master control system sends a starting instruction to the welding device; the vision system of the welding device performs secondary positioning on the battery pole to acquire deviation data of the battery pole relative to a reference position; The vision system sends deviation data to the galvanometer control system, and the galvanometer control system dynamically corrects the welding track according to the deviation data and issues a welding instruction comprising welding coordinates, the corrected welding track and a laser starting signal; After receiving the laser start instruction, the laser controller controls the laser output power in a segmented mode according to a preset time node, firstly controls the laser output power to slowly increase from zero to preset welding power, then controls the laser to weld with constant power, and finally controls the laser output power to slowly decrease from the preset welding power to zero. In one possible implementation manner, when the galvanometer control system issues a welding instruction, the laser beam is controlled to deviate to the vicinity of the center point of the pole, and the laser beam is driven to scan along the corrected welding track at a constant speed, so as to form a spiral point track. In one possible implementation manner, when the galvanometer control system issues a welding instruction, the running speed of the welding track is adjusted, so that the time point when the track scanning is completed coincides with the time point when the laser output power slowly drops to zero. In this embodiment, a ramp-up time is provided for laser output power control in the initial welding stage, that is, the laser output power is controlled by the