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

在要求极高精度的制造或测量过程中，由于夹紧力而引起的零件变形是需要解决的问题之一。特别是对于薄壁柔性零件，由于其在较小的夹紧力作用下容易变形，很难实现无弹性变形的夹紧。将电流变液的特性应用于夹持驱动器。电流变液是一种胶体悬浮液，其表观粘度根据所施加的电场强度而变化，并提供屈服应力。开发了电流变液离合器元件，并将其安装到夹紧装置上。通过控制施加到ERF夹紧致动器的电场强度来简单地控制夹紧力。从夹紧力、工件残余应变和工件在搬运过程中的稳定性等方面对所研制的电流变液装置的性能进行了评价。研究结果如下：（1）在小外力（最大值）作用下，2.45 N）作用于由电流变液薄膜离合器夹持在固定阻尼器上的浮动阻尼器，通过电流变液薄膜离合器的作用，成功地抑制了浮动阻尼器与固定阻尼器之间的相对位移。(2)通过控制施加在电流变液离合器上的电场强度，将夹紧装置上薄而柔软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.