Injection devices for internal combustion engines

Claim 1

Injection device, for an internal combustion engine, which comprises, immediately downstream of each cylinder of an injection pump wherein a piston moves, on the one hand, a delivery valve biased by a spring and adapted to open on the active portion of the delivery stroke of the piston to allow liquid fuel to arrive at an injector through a linking passage and, on the other hand, a reaspirating valve also biased by a spring, said reaspirating valve being provided with a constantly open axial passage and adapted to allow the fuel delivered from the pump cylinder to pass to the delivery valve and arranged in another passage which connects said linking passage to the pump cylinder thereby by-passing the delivery valve and adapted to open towards said cylinder when the difference in pressures between the linking passage and the cylinder exceeds a given limit, the reaspirating valve comprising a first cylindrical portion of external diameter D serving for its guidance, a second cylindrical portion of external diameter d, less than D, and a frustoconic portion, an annular seat of shape corresponding with said frustoconic portion and cooperating therewith, the maximum diameter of the frustoconic portion being equal to d, said cylindrical portions being connected by a shoulder, said second cylindrical portion and said shoulder defining internally an annular chamber which forms part of the by-pass passage.