RESEARCH ON CHARACTERICTICS OF NOISE EMISSION FROM THE RAIL (FUNDAMENTAL RESEARCH FOR NOISE REDUCTION TECHNOLOGY OF RAILROAD)

曾经一度衰落的城际铁路，随着1964年开通的新干线（东海道线）的成功运营，在世界范围内重新焕发了生机。在这一过程中，新的加速技术发挥了重要作用。然而，火车的加速不可避免地引起了噪音和振动问题。与此同时，人们已经意识到他们摆脱麻烦的权利，因此应对这些麻烦的必要性不容忽视。同样，噪音问题也存在于火车通过像“濑户大桥”这样的长铁桁架桥梁的特殊条件下。因此，解决这些问题的方法在当前具有重要的社会意义。本研究的目的是考虑钢轨本身的噪声特性，为解决钢轨噪声问题提供帮助。这也是为了再次确认“t型钢轨”的缺陷，基于我们正在申请专利的提案，该提案解释了车轮的应力可以在钢轨横截面的中心附近承受。具体地说，在t型钢轨上，质量集中的“头”块位于称为“腹板”的薄板弹簧上。它看起来非常坚固，但必须非常容易振动，就像振动模型一样，由于应力，以“吨”为单位，施加在远离轨道横截面网中心的地方。当然，它造成的噪音问题比想象的要严重得多。作为研究钢轨噪声问题的第一步，研究了钢轨的噪声发射特性。本文研究了在离钢轨中心线正常位置和在钢轨中心线附近施加应力时钢轨噪声发射的差异。我们能够得到预期的结果，即后一种情况带来了理想的结果。

The inter-city railroad, which was declining at one time, has revived worldwide with the successful operation of THE SHINKANSEN (Tokaido-Line) started in 1964.On this process, new technology for speed-up played a major role. However, the speed-up of the trains inevitably caused the problem of noise and vibration.In the meantime, people have become so conscious of their right to be free from the troubles that the necessity to cope with them can't be ignored.Similarly, a noise problem lies in a special condition in which trains run through so long iron truss-constructed bridges like "Seto Grand Bridges".So, the approach to these problems is of social importance at present.The purpose of this research is to consider the characteristics of noise emission from the rail itself and help to solve the noise problem.It is also to reconfirm the defect of the "T-type rail", based on the proposal on which we are applying for a patent, which explains that the stress from wheels can be borne nearly on the center of the cross section of the rail.To put it concretely, on the T-type rail, the "head", mass-concentrated lump, lies on thin plate spring named "web". It looks very strongly built, but must vibrates very easily, just as model of vibration, due to the stress, which is measured in "ton", applied away from the center of the web of the rail cross section.Naturally, it must have caused a more serious noise problem than can be imagined.As the first steps toward the noise problem caused by the rail, the characteristics of noise emission from the rail was studied.The difference of noise emission from the rail between in a normal position away from the center line of the rail where the stress is applied and in the vicinity of the center line had been studied.We were able to get the expected result that the latter case brings desirable fruits.