HIGH PRESSURE PUMP

摘要

A high pressure pump includes a pump body, a pressurizing chamber, a fuel passage, a union, a seat member, a relief valve seat, a relief valve, a discharge valve seat, a discharge valve, a spring and a spring holder. The union has an inner threaded portion and a step portion formed on an inner wall of the union. The seat member includes a relief passage that extends through the seat member in an axial direction of the seat member and a discharge path that is not in fluid communication with the relief passage. The one opening of the relief passage is closer to the pressurizing chamber than an other opening of the relief passage is to the pressurizing chamber. The one opening of the discharge path is further from the pressurizing chamber than an other opening of the discharge path is from the pressurizing chamber. The seat member is pressed toward the step portion when the spring holder is fastened to the union by engaging the inner threaded portion with the outer threaded portion.

主权项

1. A high pressure pump comprising:
a pump body; a pressurizing chamber defined inside of the pump body and pressurizing fuel; a fuel passage positioned inside of the pump body and communicating with the pressurizing chamber; a union having a cylindrical shape and fixed to an inner wall of the fuel passage, the union having an inner threaded portion and a step portion formed on an inner wall of the union; a seat member disposed inside of the union, the seat member including a relief passage that extends through the seat member in an axial direction of the seat member and a discharge path that is not in fluid communication with the relief passage; a relief valve seat disposed on the seat member at one opening of the relief passage, the one opening of the relief passage being closer to the pressurizing chamber than an other opening of the relief passage is to the pressurizing chamber; a relief valve seating on and separating from the relief valve seat; a discharge valve seat provided on the seat member at one opening of the discharge path, the one opening of the discharge path being further from the pressurizing chamber than an other opening of the discharge path is from the pressurizing chamber; a discharge valve seating on and separating from the discharge valve seat; a spring biasing the relief valve toward the relief valve seat; and a spring holder having an outer threaded portion that engages the inner threaded portion of the union, wherein the seat member is pressed toward the step portion when the spring holder is fastened to the union by engaging the inner threaded portion with the outer threaded portion.