号数	ばね論文集 60 号（ 2015 年）
ページ数	pp.51-105
種類	共同研究
論文名	圧縮コイルばねの疲労限度線図に関する共同研究報告
Title	Study on Fatigue Diagrams of Helical Compression Springs
著者	圧縮コイルばねの疲労限度線図の改訂調査研究委員会
Author	Research Committee on Fatigue Diagrams of Helical Compression Springs
抄録	現行JIS規格(JIS B 2704-1)の圧縮コイルばね疲労強度設計線図の妥当性を調査するため，ピアノ線と弁ばね用シリコンクロム鋼オイルテンパ線の圧縮コイルばねで疲労試験を行った．供試鋼線は市販のもので，試験用ばねは生産設備を利用して製作し，ショットピーニング有無の影響も調査した．疲労試験は室温で，応力比R一定条件(試験実施したRの範囲: 0.1〜0.7)下で，繰返し数最大107回まで実施した．疲労試験で折損しなかったばねについて荷重損失を測定し，残留せん断ひずみγを算出した．試験で得られた疲労強度はすべて現行JIS規格の疲労強度設計線図よりも大きく，γ≦0.05を満足するへたり限界の最大応力は現行JIS規格の最大応力よりも高い値になった． 　上記試験のほかに，過去の関連文献調査及び現行JIS規格，これに対応する現行EN規格およびSAE規格の比較を行った．
Abstract	In order to investigate the validity of the current JIS fatigue design diagrams for round wire helical compression springs, fatigue tests were conducted for non-shot-peened and shot-peened springs made of piano wires and valve-spring quality oil-tempered Chromium Silicon steel wires. All the spring wires supplied for the testing were commercial ones and were processed in commercial spring manufacturing lines to coil springs. Fatigue tests were conducted at room temperature until fracture or 107 cycles,under various constant stress ratios from 0.1 to 0.7. Also, load loss of each non-fractured spring at fatigue test was measured. Using each load loss thus obtained, residual shear strain γ（ Shear stress relaxation divided by shear modulus） was calculated. It was found that the fatigue strengths obtained were all above the current JIS fatigue design diagrams and that the current JIS maximum design stresses were lower than those determined by the criterion that residual shear strainγ<= 0.05 % is met. Comparison of current JIS standard with the corresponding SAE and EN standards were also made.
著者の所属
Belonging
Key Words	Round wire helical compression spring, Fatigue strength diagram, Stress relaxation, Piano wire, Oil tempered wire for valve springs, JIS B 2704-1, SAE HS -795, EN 13906 -1