| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To restrain a change in a load characteristic in use under a high temperature condition to an unproblematic level, by enhancing high heat resistant performance of a torsion coil spring used in a part of requiring heat resistance. <P>SOLUTION: This torsion coil spring has a coil part of coiling a spring wire rod made of a deposition-strengthened alloy, a first arm part extending from one end of the coil part and a second arm part extending from the other end of the coil part. After coiling the spring wire rod, first heat treatment for improving material strength is performed at the treatment temperature of 500-900°C, and while restricting the coil radial direction and the axial direction of the coil part, second heat treatment is performed for 60-600 minutes at the treatment temperature lower by 20°C or more than the treatment temperature of the first heat treatment, in a state of biasing the first arm part and the second arm part so that the coil part is diametrically contracted. <P>COPYRIGHT: (C)2011,JPO&INPIT</p> |
