Abstract: A manufacturing method of a spring assembly, assembles an annular plate and a compression coil spring. The method includes forming a protrusion having a tapered portion on the annular plate, and inserting a punch including a first portion having a larger diameter than an inner diameter of a tip end of the tapered portion from the tip end side into the protrusion to expand the tip end of the tapered portion. The expansion of the tip end of the tapered portion involves expanding a base portion of the protrusion, which extends 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 of the compression coil spring.

Abstract: Large-diameter projection portions and small-diameter projection portions are formed in each of the two annular plates, while large-diameter end turn portions, which are respectively associated with large-diameter projection portions, and small-diameter end turn portions, which are respectively associated with small-diameter projection portions, are formed in the compression coil springs. Then, a punch having a diameter portion, whose diameter is larger than the inside diameter of the large-diameter projection portion, is inserted thereinto and increases the diameter thereof. Consequently, the large-diameter end turn portions of the compression coil springs are assembled to each of the annular plates.

Abstract: A method of manufacturing a spring assembly, which includes two annular plates and compression coil springs, and which is adapted so that the compression coil springs are assembled to the annular plates by caulking projection portions formed on the two annular plates, respectively. Projection portions are formed at the side of the annular plates. Plural large-diameter walls and plural small-diameter walls are alternately provided in the circumferential direction of each of the projection portions. A punch having a portion, whose diameter is larger than the inside diameter of a space between the small-diameter walls, is inserted into an inner space among the large-diameter walls and the small-diameter walls of each of the projection portions. As the small-diameter walls of each of the projection portions are enlarged in diameter, the large-diameter walls adjoining each of these small-diameter walls are easily enlarged in diameter.

Abstract: Large-diameter projection portions and small-diameter projection portions are formed in each of the two annular plates, while large-diameter end turn portions, which are respectively associated with large-diameter projection portions, and small-diameter end turn portions, which are respectively associated with small-diameter projection portions, are formed in the compression coil springs. Then, a punch having a diameter portion, whose diameter is larger than the inside diameter of the large-diameter projection portion, is inserted thereinto and increases the diameter thereof. Consequently, the large-diameter end turn portions of the compression coil springs are assembled to each of the annular plates.

Abstract: It is a method of manufacturing a spring assembly, which includes two annular plates and compression coil springs, and which is adapted so that the compression coil springs are assembled to the annular plates by caulking projection portions formed on the two annular plates, respectively. Projection portions are formed at the side of the annular plates. Plural large-diameter walls and plural small-diameter walls are alternately provided in the circumferential direction of each of the projection portions. A punch having a portion, whose diameter is larger than the inside diameter of a space between the small-diameter walls, is inserted into an inner space among the large-diameter walls and the small-diameter walls of each of the projection portions. As the small-diameter walls of each of the projection portions are enlarged in diameter, the large-diameter walls adjoining each of these small-diameter walls are easily enlarged in diameter.

Abstract: A manufacturing method of a spring assembly, assembles an annular plate and a compression coil spring. The method includes forming a protrusion having a tapered portion on the annular plate, and inserting a punch including a first portion having a larger diameter than an inner diameter of a tip end of the tapered portion from the tip end side into the protrusion to expand the tip end of the tapered portion. The expansion of the tip end of the tapered portion involves expanding a base portion of the protrusion, which extends 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 of the compression coil spring.