Development of Low Noise Blanking Press

研究压力机工作过程中的减振降噪对我们的社会和环境都具有重要意义。考虑到材料断裂会导致明显的振动和噪声水平，研究降低冲裁过程中的振动和噪声甚至是很重要的。已经推测，在冲裁过程中遇到的高电平声音是在所谓的穿透周期或现象或期间引起的，并且在该穿透时发现的最大声级与例如在压框内存储的弹性能量的释放速度密切相关。然而，即使是这一领域的现状也没有达到可以严格和/或定量定义这种突破的水平，也没有在阐明突破的基础上提供任何有效的对策来减少所述的振动和噪声。因此，本研究首先旨在观察突破现象，并定量确定突破的发生时间。然后通过测量冲头(上模)的速度和冲裁力的减小速度来获得弹能的释放速度，最后通过对获得的数据进行深入观察和定量分析，验证了上述推测的正确性。在此基础上，开发了具有液压惯性阻尼器的冲裁压力机，与传统冲裁压力机相比，该压力机能够更有效、更容易地降低冲裁噪声。我们研制的压力机与无挡板的压力机相比，可使压力机的噪声降低10dB以上。

The research on decreasing vibration and noise during press working is of great importance for our society and environment. It is even inportant to research into decreasing said vibration and noise during blanking work in view of the material fracture involved leading to the consequent significant level of vibration and noise. It has been already speculated that the high level sound met during blanking is caused at or during so-called break through period or phenomenon, and that the maximum sound level found at this break through has a close relationship with the release velocity of elastic energy stored, e.g., within the press frames. However, even the state of art in this field has neither reached a level at which this break through can be rigorously and/or quantitatively defined nor provided any effective countermeasures to reduce the vibration and noise in question based on the elucidation of the break through.Accordingly, first the present sutdy aimed at observed the break through phenomenon, and quantitatively determining the onset of break through. Then the author measured the punch (upper die) speed and the reduction speed of blanking force in order to obtain the release speed of the elastic energy, and finally verified the above speculation to be true by indepth observation and quantitative analysis on the data obtained. Further, based on the knowledge obtained, a blanking press with a hydraulic inertia damper was deeloped ; the press enabled to reduce the blanking noise more effectively and easily than the conventional blanking press. The present press developed by us have proved to be able to reduce the noise level of blanking presses by the amount more than 10dB from those without the damper.