| 摘要 |
PURPOSE: To provide a spring assembly, which is used as, for example, a return spring member for a multi-plate clutch piston in a clutch mechanism of an automatic transmission of a motor vehicle, and a method for manufacturing the same. CONSTITUTION: In a manufacturing method of a spring assembly, for assembling an annular plate(1B) and a compression coil spring(2), the method comprises the steps of forming a protrusion(4B) having a tapered portion(5) on the annular plate; and inserting a punch(13) including a first portion having a larger diameter (D4) than an inner diameter (D3) of a tip end of the tapered portion from the tip end side into the protrusion to expand at least part of the tapered portion, wherein the expansion of the at least part of the tapered portion involves expanding a base portion of the protrusion, which continues the tapered portion and has a larger inner diameter than that of the tip end of the tapered portion, along a surface of an end turn(2b) of the compression coil spring. The spring assembly comprises an annular plate(1B); and a compression coil spring(2), wherein a protrusion(4B) formed on the annular plate is caulked to assemble the annular plate and the compression coil spring, and the protrusion is folded inward at a height exceeding a radius of wire of an end turn of the compression coil spring and is superposed itself doubly. |
