OVERFLOW VALVE FOR A HIGH PRESSURE PUMP, HIGH PRESSURE PUMP, AND METHOD FOR OPERATING AN OVERFLOW VALVE

The invention relates to an overflow valve (11) for a high pressure pump (105), in particular a fuel injection system, preferable in a common-rail fuel injection system, comprising a valve element (2), which is received in a movable manner in a housing bore (1), for connecting a valve inlet (3) to at least one valve outlet (5), and a spring (7), which is received in a spring space (6) and the spring force of which acts on the valve element (2) in the direction of the valve inlet (3). According to the invention, the at least one valve outlet (5) is provided in the form of an opening of a housing wall (25), in particular in the form of a bore which opens into the housing bore (1) preferably in a radial manner. The valve element (2) comprises an interior (30) which is open towards the valve inlet (3). The valve element (2) further comprises a throttle opening (4) in a surrounding wall (35) of the interior (30), said throttle opening releasing a flow out of the interior (30) of the valve element (2) to the at least one valve outlet (5) in the housing wall (25) in a first region of the position of the valve element (2) in the housing bore (1). The invention further relates to a high-pressure pump (105) comprising such an overflow valve (11) and to a method for operating an overflow valve (11) in at least two stages with different flow rates Q, wherein the overflow valve (11) is arranged in a high-pressure pump (105) of a fuel injection system of an internal combustion engine and adjusts a supply pressure of the overflow valve (11) by means of a pre-supply pump, and the overflow valve (11) is operated with a lower flow rate Q in a first stage or with a higher flow rate Q in a second stage depending on the supply pressure.