摘要 |
The invention relates to a device for modulation of servo pressure in a steering gear (1) comprising an input shaft (2) which is attached to a rack (4; 4'), a servo mechanism (9-17) for supply of power to the rack (4; 4') and comprising a box (8; 8) with a first channel (18, 20, 21) and a second channel (19) for the supply and return, respectively, of servo medium, and a connection channel (22; 29, 30) between the first and the second channel (18, 20, 21, 19). The invention further comprises means (28; 36) for detecting whether the rack (4; 4') is in a predetermined position, and a valve member (23; 31) for opening the connection channel (22; 29, 30) when said position is detected. The invention is characterized in that the valve member (23; 31) interacts with the rack (4; 4') and has its extension through the connection channel (22, 29, 30), and in that said means (28; 36) are constituted by a shape modification in the rack (4; 4') with which the valve member (23; 31) interacts when detecting said position, whereby the valve member (23; 31) is influenced to open and close, respectively, the connection channel (22; 29, 30). By means of the invention, an improved device for reduction of the load from the servo device, when the steering wheel has been turned to a predetermined position, is provided.
|