软体适形柔顺夹持原理及关键技术研究

Applying pneumatic power for holding and conveying work-pieces has technical advantages such as flexibility, safety, convenient maintenance. However, the existing pneumatic negative pressure adsorption devices or pneumatic grippers are designed for specific work-pieces, where the material and shape of the workpiece is limited to a small scale. In order to meet the requirements of flexible and stable clamp operation in multi-workpieces manufacturing, by combining the positive pressure drive and negative pressure adsorption technology, the proposal proposes a soft body shape adaptive clamp method to enlarge the contact area in order to adapt to the shape of the workpiece. Meanwhile, the vacuum generator is added in the flexible clamp instrument to increase the load capacity. Based upon the investigation of bionic soft clamp principle, the applicant proposes a novel structure composed of high-density elastic multi-chamber soft body and vacuum suction stoma structures. The coupling mechanisms between gas and soft bodyas well as that of soft body and workpiece will be analyzed. The clamping mutual-coupling model will be built and verified uponexperimental results. A vacuum generation device and vacuum suction stoma will be designed, where the core element is the Laval nozzle.Factors affecting the vacuum loading scheme will be studied in order to propose the solution of increasing vacuum suction force. Upon the completion of this research proposal, theoretical preparation and technical foundation will be provided for bionic soft clamping technology.

使用压缩空气作为驱动力进行物品夹持和搬送具有柔顺安全、维护方便等优点。然而，现行气压夹持方法对夹持物的材质、形状和重量有严格的限制，不能适应多品种和规格的物品。本课题针对混流生产物品搬送和柔顺夹持的需求，提出软体适形柔顺夹持方法，以气压驱动的软体结构增大夹持装置与物体的接触面积来适应物体的形状，并集成负压发生设备于柔顺夹持装置中来大幅提高柔顺夹持装置的负载能力。通过对软体生物变形机理的研究，研究形状适应的软体夹持原理和实现方法，提出高密度弹性材料多腔室软体和负压吸着口盘相结合的结构形式，并研究气体与软体型腔间相互作用关系、软体与夹持物的耦合规律，根据试验结果进行修正并建立软体夹持器静态特性和夹持物多维耦合理论模型；设计以拉瓦尔喷管为核心元件的负压发生装置和负压吸着口盘，研究负压吸着力的影响因素并制订负压加载夹持力增强技术方案。课题研究可望为软体适形柔顺夹持的实现奠定理论和技术基础。

本研究针对混流生产物品搬送和柔顺夹持的需求，借鉴软体生物的结构和功能特点，提出软体适形柔顺夹持方法，设计并制作了一种新型软体驱动气动夹持装置，包括软体驱动单元和多个触手单元，触手单元对称分布在软体驱动单元上。由于其驱动单元和触手单元均由高气密性特种橡胶构成，充入压缩空气后，软体驱动单元驱动触手单元张开或闭合，触手单元柔软可弯曲，能贴合多种几何轮廓，达到多种形状物体柔顺夹持的目的，且具有夹持力可调、触手单元开合角度可调等特点。为了增强夹持力，设计了负压发生装置和负压吸着口盘，构建了负压抽吸试验系统，研究了真空压力、抽吸流量、吸着响应时间等关键参数，在理论上进行了探索，提出了考虑热传递的真空容腔压力响应模型，并分析了系统背压对负压发生设备工作性能的影响。在此基础上，进一步探索并成功实现了负压塑形技术，提出高密度弹性材料多腔室软体和负压塑形单元相结合的结构形式，研究气压力不同时软体驱动器变形量、塑形单元与夹持物的耦合规律，并得出技术实现方案，即用绝缘细颗粒物填充末端气囊，充气后先适应物体外轮廓发生变形，继而抽真空使气囊固化为夹持物外形，从而与物体形成可靠约束，对于外形尺寸不规则的异型件有良好的夹持效果。研制成功的新型软体驱动气动夹持装置以气压驱动的软体结构增大夹持装置与物体的接触面积来适应物体的形状，并集成负压塑形技术于柔顺夹持装置中来大幅提高柔顺夹持装置的负载能力，实现了低成本有效夹持操作。本研究为柔性夹持装置提供了理论和技术支持，对企业实现混流生产和提高生产效率具有工程应用参考价值。