HIGH-PRESSURE FUEL FEED PUMP, AND DISCHARGE VALVE UNIT USED THEREIN

A high-pressure fuel supply pump mounted with a discharge valve that can reduce an influence of noise caused by a valve body-circumferential flow and a discharge valve unit used therein. The high-pressure fuel supply pump includes a discharge valve (8) which is a non-return valve between a pressurizing chamber (11) and a discharge port (13). The discharge valve (8) includes a valve body housing (8d), a discharge valve spring (8c), a valve body (8b) and a seat member (8a). The discharge valve (8) is a flat valve. When the valve is opened, a flow of fuel moving from the pressurizing chamber and axially colliding with the valve body is radially distributed in the radial direction of the valve body to become a flow directly moving the discharge ports and a flow colliding with an inner wall of the valve body housing before moving toward the discharge ports and then in a circumferential direction of the valve body. The discharge valve (8) is provided with a liquid damper chamber defined between an outer circumference of the seat member (8a) and an outer circumference of the valve body (8d) and an inner circumference of the valve body housing (8d) to face the flow in the circumferential direction. The liquid damper chamber includes first, second and third tubular passages (503A, 503B, 503C).