초록 ▼

A device for controlling a hydraulically operable switching element (2) of an automatic transmission of a vehicle with a position valve mechanism (3) having a main switch piston (6) which is spring biased into a first switch position and a second switch position with a pilot pressure (P_MV) which is

A device for controlling a hydraulically operable switching element (2) of an automatic transmission of a vehicle with a position valve mechanism (3) having a main switch piston (6) which is spring biased into a first switch position and a second switch position with a pilot pressure (P_MV) which is adjustable through an electrically operated actuator (5). An additional switch piston (7) and the main switch piston (6) are axially actuated in a valve housing (8). Depending on the position of the pistons (6, 7), faces (6A, 7A) of the respective pistons are either spaced apart or adjacent. The additional switch piston (7) is adjustable depending on a pilot pressure (p_K) of a switching element which engages a gear for forward drive.

대표청구항 ▼

The invention claimed is: 1. A device (1) for controlling a single hydraulic switching element (2) of an automatic transmission of a vehicle, the device (1) comprising:a position valve mechanism (3), including a system pressure input port (32), a system pressure output port (33), at least two contro

The invention claimed is: 1. A device (1) for controlling a single hydraulic switching element (2) of an automatic transmission of a vehicle, the device (1) comprising:a position valve mechanism (3), including a system pressure input port (32), a system pressure output port (33), at least two control ports (36, 37, 38), a main switch piston (6) and an additional switch piston (7);the additional switch piston (7) and the main switch piston (6) each being coaxially slidable within a valve housing (8) between respective first and second switch positions;the main switch piston (6) is hydraulically biased into the second switch position by an adjustable actuator pilot pressure (P_MV) and resiliently biased into the first switch position;the additional switch piston (7) is hydraulically biased, via a working chamber (9), to the second switch position with a switching element pilot pressure (p_K); andthe main switch piston (6) has a control area located between two lands of the main switch piston (6), the control area of the main switch piston (6) having a reduced diameter compared to diameters of the two lands of the main switch piston (6), the system pressure input port (32) is connected to a system pressure (p_sys), and the system pressure output port (33) is connectable with the system pressure input port (32), depending on an axial position of the main switch piston (6), for controllably providing the system pressure (p_sys) at the system pressure output port (33); andthe additional switch piston (7) has a control area located between two lands (18, 19) of the additional switch piston (7), the control area of the additional switch piston (7) having a reduced diameter compared to diameters of the two lands (18, 19) of the additional switch piston (7), a first control port (36) of the at least two control ports is connected to one of a valve mechanism pilot pressure (p_EDS) and the system pressure (p_sys) and is connectable with a second control port of the at least two control ports (37, 38), depending on an axial position of the additional switch piston (7), for controllably providing the one of the valve mechanism pilot pressure (p_EDS) and the system pressure (p_sys) at the second control port of the at least two control ports (37, 38); anda pressure regulation valve (10), comprising a first input port (101), an output port (102), a second control input port (105) and a valve gate piston (12) which is axially slidable in a valve housing (11) between first and second positions;the valve gate piston (12) being resiliently biased toward the first position and hydraulically biased toward the second position by the valve mechanism pilot pressure (p_EDS) which is provided to the second control input port (105) of the pressure regulation valve (10);the valve gate piston (12) having a regulation control area located between two lands of the valve gate piston (12), the regulation control area of the valve gate piston (12) having a reduced diameter compared to diameters of the two lands of the valve gate piston (12); andthe first input port (101) of the pressure regulation valve (10) is connectable with the system pressure (p_sys) via the position valve mechanism (3);the output port (102) of the pressure regulation valve (10) controllably providing a switching element control pressure (p_2) to the switching element (2) depending on an axial position of the valve gate piston (12); andthe switching element control pressure (p_2) is controlled by the adjustable actuator pilot pressure (P_MV), the valve pilot pressure (p_EDS) and the switching element pilot pressure (p_K).