Fuel pump

A fuel pump provided with

• a compression chamber for compressing fuel, and
• a discharge valve element that is arranged on a discharge side of the compression chamber and to which biasing force in a valve closing direction of the discharge valve element is applied,
• and being configured such that fuel is taken into the compression chamber in an intake stroke, and in a case in which pressure in the compression chamber has reached or exceeded a predetermined pressure in a compression stroke, the discharge valve element moves in a valve opening direction of the discharge valve element against the biasing force, and fuel is discharged from the compression chamber toward a fuel injection valve,
• the fuel pump comprising:
• a micro gap opening/closing portion that, in a case of a change from a pump drive state to a pump stopped state, causes the compression chamber and a space on a downstream side of the discharge valve element to be in communication with use of a micro gap, and in at least the intake stroke during pump driving, obstructs the micro gap,
• wherein an opening that enables communication between the compression chamber and the space on the downstream side of the discharge valve element is formed in the discharge valve element,
• the micro gap opening/closing portion is provided with a micro gap opening/closing element that can advance and retreat between a first advance/retreat position reached by retreating from the opening of the discharge valve element to release the opening and cause the compression chamber and the space on the downstream side of the discharge valve element to be in communication, and a second advance/retreat position reached by advancing toward the opening of the discharge valve element to obstruct the opening and block off the compression chamber and the space on the downstream side of the discharge valve element, and
• the micro gap opening/closing element is configured so as to open and close the micro gap formed between an inner edge portion of the opening and the micro gap opening/closing element by, with use of an electromagnetic solenoid as a drive source, moving between the first advance/retreat position and the second advance/retreat position according to conduction/non-conduction of electricity to the electromagnetic solenoid.