Development of low strain clamping device for compliant parts apply-ing characteristics of Electro-Rheological Fluid

在精度要求极高的制造或测量过程中，夹紧力引起的零件变形是需要解决的问题之一。尤其是薄而柔顺的零件，由于夹持力较小，容易发生变形，在没有弹性变形的情况下很难夹持。将电流变流体的特性应用到夹紧执行器中。电流变液是一种胶体悬浮液，其表观粘度随外加电场强度的变化而变化，并提供屈服应力。研制了电流变液离合器元件，并将其安装到夹紧装置上。通过控制施加在电流变液夹紧执行器上的电场强度，简单地控制夹紧力。从夹紧力能力、被夹紧件上的残余应变和装置搬运过程中保持稳定性的角度对所研制的电流变液装置的性能进行了评价。主要研究结果如下：(1)当外力较小时(Max.通过电流变液膜离合器固定在固定阻尼器上的浮动阻尼器施加2.45N)，通过ERE效应成功地抑制了浮动阻尼器和静止阻尼器之间的相对位移。(2)通过控制电流变离合器上的电场强度，将夹紧装置上薄而柔顺的零件的弹性变形减小到极低的水平。

The deformation of the parts due to the clamping force is one of the issues to be solved in manufacturing or measuring process where extremely high accuracy is required. Especially, it is difficult to clamp the thin andd compliant parts without the elastic deformation, because they are easily deformed by the small clamping force.In this research, a new mechanical three-point-support clamping device is developed. The characteristics of electrorheological fluid (ERF) is applied to the clamping actuator. The ERF is a kind of colloidal suspension, whose apparent viscosity is variable depending on the applied electric field intensity and it provides the yield stress. The ERF clutch element is developed and installed to the clamping device. The clamping force is simply controlled by controlling the applied electric field intensity to the ERF clamping actuators. The performance of the developed ERF device was evaluated from the viewpoint of capacity of clamping force, residual strain on the clamped parts and parts holding stability during carry of devices. The results are summarized as follows ;(1) When the small external force (Max. 2.45 N) is applied to the floating damper which is clamped to the stationary damper by the ERF film clutch, the relative displacement between the floating damper and stationary damper is successfully suppressed to him by the ERE effect.(2) The elastic deformation of the thin and compliant parts on the clamping devise is reduced to the extremely low level by controlling the applied electric field intensity to the ERF clutch.