HYDRAULIC POWER STEERING DEVICE

PROBLEM TO BE SOLVED: To prevent a sudden change of steering assisting force without being influenced by temperature, and to obtain good steering feeling, in a hydraulic power steering deice changing the steering assisting force according to a driving state. SOLUTION: A regulating means regulates elastic relative rotations of an input/output shaft according to steering torque for controlling hydraulic pressure for generating the steering assisting force by acting the hydraulic pressure on a pressure receiving portion. The regulating means has a hydraulic pressure adjusting mechanism 60 adjusting the hydraulic pressure acting on the pressure receiving portion according to a driving state, and a boosting speed regulating mechanism 70 regulating rising speed of the hydraulic pressure adjusted by the hydraulic pressure adjusting mechanism 60. As thrust toward an opening increasing direction of a pressure oil supplying passage 80 to the pressure receiving portion, an elasticity generating portion 71 adds elasticity to a spool 70a. As thrust toward an opening decreasing direction of the pressure oil supplying passage 80, fluid friction force according to viscosity of pressure oil is added to the spool 70a. A temperature sensitive means is provided, which lowers the elasticity added to the spool 70a by temperature rise of the pressure oil flowing through the pressure oil supplying passage 80, and increase the elasticity by temperature fall. COPYRIGHT: (C)2007,JPO&INPIT