粉体肉盛溶接を適用したブレーキディスクの開発

摘要

Improvement of the braking force that will contribute to the further safe operation of high speed vehicle is an important research issue in all the countries in the world. Reduction of the brake distance is an effective safety measure particularly in Japan where the earthquake often occurs. However, improvement of the braking force will usually put higher heat load on the brake disk in case of the emergency braking, causing various problems such as damages of disk surfaces. In order to mitigate the thermal effects of disk material, we studied several methods and developed a method to form built up welding layer on the disk surface using the plasma transferred arc welding (PTA). In this paper, we report the summary of the evaluation of performance of this method applied to brake disk on dynamo test bench up to 400km/h. It was proven that the improved brake disk ensured the target brake distance, and the built up layer and the base material of the brake disk after the test bench maintained a state in which a crack hardly occurs.%本研究において得られた結果は以下の通りである。(1) ブレーキ時の入熱によるディスク母材への熱影響の緩和と熱変形の抑制を目的に，ディスク母材の摺動面に厚さ2mmの下盛層および厚さ3mmの上盛層からなる肉盛層を粉体肉盛プラズマアーク溶接(PTA)により形成する手法を開発し，台上試験用のPTA中央締結型ブレーキディスクを試作した。(2) 初速度400km/hまでの台上試験を実施し，肉盛しない母材型と比較して，締結ボルトの最大軸力が約10%低減されることを確認した。