To provide a stable injection characteristic, by suppressing a seizure at the sliding part of a rotor and a supporting member in a good condition, and making the residual pressures in the fuel delivery passages even, in an inner cam system fuel injection pump.
In a rotor 8, two balance ports 44a and 44b slipped symmetrically in the peripheral directions making the Y-shape relative to a distribution port are formed. The opening ends of the balance ports and the opening end of the distribution port 33 are set on the same surface vertical to the shaft of the rotor 8. When the slipping angle in the peripheral direction of the distribution port 33 and the balance ports 44a and 44b is made θ, the opening area S1 of the distribution port, and the opening area S2 of the balance ports, are set to satisfy the relation S1=2.S2.cosθ. The phase interval of fuel delivery passages 32, and the phase interval of the balance ports 44a and 44b, are set equal.
URANO MITSUNORI
YOKOTA TORU
MATSUBARA ATSUSHI
Next Patent: SEAL RING