| 摘要 |
PROBLEM TO BE SOLVED: To prevent unallowable pressure peak, and avoid cavitation in a high pressure fuel pump when a diaphragm accumulator breaks down by improving the high pressure fuel pump having the diaphragm accumulator. SOLUTION: This high pressure fuel pump for an internal combustion engine comprises a piston pump, a fuel supplying portion, a high pressure conductor, an amount control valve for controlling a bypass of the piston pump, and a diaphragm accumulator. The piston pump carries fuel from the fuel supplying portion to the high pressure conductor. A diaphragm of the diaphragm accumulator controls a 2/2 direction control valve disposed on the fuel supplying portion. When difference in pressure is generated on both sides of the diaphragm, the 2/2 direction control valve is opened, and when the same pressure is generated on both sides of the diaphragm, the 2/2 direction control valve is closed.
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