| 摘要 |
PCT No. PCT/SE89/00547 Sec. 371 Date Mar. 26, 1991 Sec. 102(e) Date Mar. 26, 1991 PCT Filed Oct. 5, 1989 PCT Pub. No. WO90/03909 PCT Pub. Date Apr. 19, 1990.A hydraulic steering system for turning two mutually articulated vehicle-halves (13, 14) relative to one another with the aid of two hydraulic piston-cylinder devices (11, 12) includes a control valve (17) which will normally connect the piston-cylinder devices in a manner such that the devices operate as single-acting piston-cylinder devices. When abnormally high steering torque prevails, however, and the oil pressure rises correspondingly above a pre-determined value, the setting of the control valve is adjusted by these oil pressures so that the valve connects the piston-cylinder devices in a manner which causes the devices to operate as double-acting piston-cylinder devices. |
