| 摘要 |
<p>PROBLEM TO BE SOLVED: To enable manufacturing a resin-made disk brake piston inexpensively while satisfying the performance to be required for the disk brake piston by hemispherically shaping a recess part tip end shape of the resin-made disk brake piston. SOLUTION: In a resin-made disk brake piston, when the outer diameter of a piston, for example, isϕ30mm and the inner diameter thereof isϕ20mm, a tip end part 3 of a recess part 1 on the inner diameter side is formed into the hemispherical shape of a 10mm radius, and the minimum thickness of the ceiling side is 5mm. Preferably, a ratio of the thickness of the piston to the outer diameter is set in the range of 1/5 to 1/7 in a balance between levels of a low cost and required withstand pressure strength. Thus, an inexpensive resin-made disk brake piston can be provided in comparison with the metallic piston, which could not be achieved in the conventional shape.</p> |
