Damper valve for hydraulic power steering device

A damper valve usable in a hydraulic power steering device the damper valve being disposed in a hydraulic oil circuit, for connecting an oil passage changing-over valve disposed in a gear box and left and right oil chambers of a power cylinder to each other, and which is provided with a partition plate member for partitioning the interior of a valve casing into two valve chambers, comprising;

• a plurality of through holes formed in the partition plate member at equal intervals along a peripheral direction thereof;
• a first valve spring plate for opening/closing every other one of the plurality of through holes fixed to one side wall of the partition plate member facing a first valve chamber of the two valve chambers positioned on a side of the oil passage changing-over valve;
• a second valve spring plate for opening/closing the other every other one of the plurality of through holes fixed to the other wall of the partition plate member facing a second valve chamber of the two valve chambers positioned on a side of the power cylinder;
• wherein
• the spring force of the first valve spring plate is stronger than the spring force of the second valve spring plate, and
• said damper valve for a hydraulic power steering device arranged and constructed such that when the first valve spring plate and the second valve spring plate close the every other one of the plurality of through holes and the other every other one of the plurality of through holes, respectively, small flow paths allowing a small amount of hydraulic oil to flow are formed between the first and second valve spring plates and respective through holes closed by the first and second valve spring plates.