Laser device which is used to pierce holes in components of a fluid-injection device

Abstract

The device has a laser resonator (4) to generate primary impulsions having duration of microseconds. Modulation units (8) are arranged in between the resonator and a head (24) of the device. The modulation units modulate amplitude of the primary impulsions to supply a set of secondary impulsions. The laser resonator is formed by an active solid atmosphere and optical pumping units.

Description

technical field [0001] The invention relates to a laser machining device for drilling holes in components of a fluid injection device, in particular for injecting fuel into an internal combustion engine. "Internal combustion engine" means any type of engine or reactor in which fuel is supplied directly or indirectly to at least one combustion chamber by injection means. "Spray device component" means in particular a nozzle, a flow controller or even a filter. Background technique [0002] Currently, various methods are known for drilling holes in the aforementioned components, in particular using specific laser devices. For example, it has been proposed to use a diode-pumped solid-state laser (DPSSL) provided with a Q-switching device for the resonator. Such lasers generate many pulses of very short duration, typically much less than 1 μs, eg 15 nanoseconds. [0003] Various companies have manufactured laser devices of the above-mentioned type. The use of such diode-pump...

AI Technical Summary

Problems solved by technology

The main disadvantage of this is that the accuracy of the holes to be machined is limited so that good repeatability from hole to hole is not possible

As a result, the geometry of holes machined by flashlamp-pumped lasers has poor machining tolerances, making it impossible to accurately determine the flow rate of fluid through such holes

[0004] However, machining holes with a laser device equipped with a Q-switch to generate very narrow pulse trains on the order of nanoseconds creates a hole processing efficiency problem

Indeed, the machining of holes, especially those of a certain depth, requires a large number of such continuous pulses, which limits the speed at which such holes can be machined and thus the industrial productivity of such machining

Furthermore, this type of laser device is relatively inflexible, since it is not possible to vary the distribution of pulses generated by the resonator in order to obtain pulses with an intensity distribution suitable for machining various types of holes

Consequently, it is difficult to vary the geometry of the machined hole due to the inability to flexibly adjust the parameters defining the very narrow pulses produced by the resonator

Additionally, nanosecond pulses cannot be used to machine larger diameter holes without going through machining methods that require multiple holes to be drilled along circular contours

Finally, the frequency of the Q-switch is limited due to the formation of plasma for a short period of time, which absorbs light energy from subsequent pulses if the plasma is still present on the hole machining area

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