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Fiber Lasers: The Best Solution for EV Hairpin Motor Applications
Hairpin Stripping
Before welding hairpins together, it is necessary to remove the insulating layer. Typical requirements for this include high process velocity, clean edge (residue-free), no thermal damage to the insulating material and no oxidation of surface.
The process usually consists in the ablation of an area of around 8 to 12 mm, removing the insulating material to reveal the copper, which will later me welded to other hairpin. Compared to other technologies, laser hairpin stripping is an easy to use, contact-free method, that offers:
- Defined edge
- Residue-free
- No thermal damage of insulation
- No oxidation of surface
- No tool wear
- No reduction of cross section
These features make fiber laser the best option for hairpin stripping, as it meets all the requirements that make the process faster and of higher quality. Solutions for insulation stripping are generally pulsed lasers combined with scanners that are integrated into the motor assembly tools.
Hairpin Welding
Typical requirements for hairpin welding include electrical conductivity of the weld seam, homogeneous weld cross section, low spatter, no pores, define edge and low thermal input. All these requirements are covered by IPG fiber laser solutions. Additionally, depending on the customer needs, the weld can either be a ball weld or a butt weld.
For hairpin welding, solutions may be either individual lasers or the combined Integrated Laser Welding System (ILWS), which includes a programmed controller and vision alignment system to make tooling and line integration even easier.
The IPG scanners not only allow to locate all the pins on a single scan field, eliminating part motion steps, but are capable of pre-scanning in order to verify and, if necessary, correct pin position to ensure flawless welding.