| 摘要 |
PROBLEM TO BE SOLVED: To allow the hydraulic pressure to be relieved when the pressure in a reaction force chamber rises by providing a relief valve that opens when the pressure in the reaction force chamber is equal to or greater than a predetermined value in a linking oil passage between the reaction force chamber that introduces a high pressure oil to a plunger and a low pressure chamber that introduces a low pressure oil, so as to prohibit an increase in steering effort. SOLUTION: When a pressure oil discharged by a hydraulic pump, the flow rate of which is controlled to a predetermined value, is supplied to an inlet port 11 of a gear box portion, it is supplied to a high pressure chamber 82 between a valve housing 10 and a pinion shaft 40 through a solenoid valve. The pressure oil pressurizes the other end surface of a reaction force plunger 72, thus a projection of a valve shaft 20 is sandwiched by projections on both sides. This makes a relative rotation between a valve body 30 and a valve shaft 20 less likely to occur and reduces an assist force generated in the steering system. A relief valve 75 incorporated in a bolt 74 for preventing a reaction plunger from slipping relieves increased pressure in the high pressure chamber 82 to the low pressure chamber 80. This enables control of steering effort with a large operation angle of a steering wheel. |
