| 摘要 |
PROBLEM TO BE SOLVED: To provide a high pressure pump capable of preventing occurrence of vapor lock due to inflow of a fuel of high temperature in a sub-fuel chamber into a main fuel chamber.SOLUTION: A check valve member 301 is held between a driving-side end face 101 of a pump body 10 and a bottom surface of a flange portion of an upper seat 45. When pressure difference obtained by subtracting a pressure of a communication passage 14 from a pressure of the sub-fuel chamber 13 is a prescribed pressure or more, a lead valve portion 35 is brought into a valve close state. The fuel of high temperature in the sub-fuel chamber 13, of which a temperature is increased by heat generation of the fuel leaking through a sliding clearance between a cylinder 20 and a plunger 41 and heat transferred from an engine side, is discharged to the external through a discharge passage 15. Thus vapor lock caused by inflow of the fuel of high temperature in the sub-fuel chamber 13 into the main fuel chamber 12 through the communication passage 14 can be prevented. When the lead valve portion 35 is opened, a fuel of low temperature in the main fuel chamber 12 flows into the sub-fuel chamber 13 through the communication passage 14. The fuel of the sub-fuel chamber 13 is cooled by the inflow of the fuel of low temperature. |
