The two-spring injectors have been designed as a development of standard injectors, supplemented with a two-stage injection process, leading to the reduction of engine noise. In this type of injector, two springs are placed one after the other. During injection, one spring acts on the needle of the sprayer first, which determines the opening pressure of the injector. Through it, a preliminary stroke takes place, which allows a small amount of fuel to be injected into the combustion chamber. Then, with larger strokes, the second spring starts its action, which also begins to act on the spray needle, thanks to which the needle makes a full stroke and then the main dose of fuel is injected into the combustion chamber.