Development of High-Precision Parts for New Semi-Active Suspension Mechanism

We received a request to develop a piston and pilot case for a new semi-active suspension with a built-in damping force control valve. The built-in valve mechanism is subject to high internal pressure, so each part required high sealing performance and rigidity. A combination piston was adopted due to port specifications, but there were concerns about sealing performance. There were also concerns about pressure resistance due to the complicated oil passages arranged on the seat surface. The pilot case has a complicated seat surface shape, so ensuring flatness was an issue. In this paper, we overcame these issues by setting appropriate conditions by correctly evaluating the performance using CAE analysis and 3D measurement. Here, we will report on the development process, which started with the material and set appropriate conditions.