Leaf spring for vehicle and method of manufacturing the leaf spring
AssigneeNHK Spring Co., Ltd.
InventorsMamoru Akeda, Junichi Yano, Isamu Okuyama, Akira Tange
Life of this patent
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Abstract
Leaf springs have improved durability in spite of using inexpensive spring steel such as SUP9 and SUP11 as materials. While a spring main body, made of the spring steel in which Brinell hardness is under 555 HBW and not less than 388 HBW (corresponding to a diameter of under 2.70 mm of hardness and not less than 3.10 mm of hardness on a Brinell ball mark), is maintained at 150 to 400° C., the load is applied in the direction in which the spring main body is to be used, and the first shotpeening is performed at the plane where the tensile stress acts.
Claims5
A production process for a leaf spring for a car, the process comprising:
- holding a spring main body made from a spring steel in which Brinell hardness is under 555 HBW and not less than 388 HBW, corresponding to a diameter of under 2.70 mm of hardness and not less than 3.10 mm of hardness on a Brinell ball mark, at 150 to 400° C.;
- applying a load in the direction equal to that in which the spring main body is to be used;
- and
- performing first shotpeening at the plane where a tensile stress is applied.
Dependencies are inferred from the claim text.