HIGH-PRESSURE FUEL SUPPLY PUMP

摘要

PROBLEM TO BE SOLVED: To reduce a radial force acting on a plunger, by a high-pressure fuel supply pump that transmits rotation of a cam to the reciprocating plunger via a tappet and a retainer.

SOLUTION: This high-pressure fuel supply pump includes a retainer that is attached to the plunger, and a return spring that applies a biasing force to the retainer in a tappet direction. A gap between a leading end of the plunger and a bottom surface of the tappet facing the leading end of the plunger is set larger than a gap between a bottom surface of the retainer and the bottom surface of the tappet facing the bottom surface of the retainer. A gap between an inside-diameter part of the retainer and a peripheral surface part of the plunger facing the inside-diameter part of the retainer is set larger than a gap between an outside-diameter part of the retainer and an inner wall of the tappet facing the outside-diameter part of the retainer. Thus, the radial force acting on the plunger which is generated due to flexural deformation and shear deformation of the spring is prevented from being transmitted to the plunger. The plunger is prevented from biting into an inner wall of a cylinder.

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