| 摘要 |
The invention relates to a pressure-limiting valve (1), in particular for arrangement in a return line of a common rail system of an internal combustion engine, comprising a valve housing (2), which has a housing head (3) and a hollow cylindrical housing jacket (4), in which an axial inlet opening (6) and at least one outlet opening (7) axially spaced from the inlet opening (6) are located in a valve base (5) of the valve housing (2), wherein an inner valve seat (8) for a valve body (9) is connected to the inlet opening (6) in the valve base (5), and wherein an axially movable valve piston (11) is arranged between the valve body (9) and a closing spring (10), which produces a closing force against a pressure (p) acting at the inlet opening (6). In order to improve the functional characteristics of the valve (1), the valve body (9) is designed as a stepped piston, which in the first step (9a) of the stepped piston has a first area (A1) to which the pressure (p) can be applied in the axial direction on the side of the stepped piston facing the inlet opening (6) and a first axial length (L1), over which the stepped piston forms a first circumferentially extending throttling gap (14) with an inner surface (8b) of the valve seat (8) by means of the outer surface (9d) of the stepped piston in a closed position, and which in the second step (9b) of the stepped piston has a second area (A2) to which the pressure (p) can be applied in the axial direction (X-X), which second area forms an overall pressure area (AG) together with the first area (A1), wherein in the second step (9b) a second circumferentially extending throttling gap (15) having a second gap width (Sw) is formed between the outer surface (9e) of the stepped piston (9) and an inner surface (2a) of the housing jacket (4) over a second axial length (L2). |
