Fixture Modules Research Articles

Modular intelligent fixture system for flexible clamping of large parts

In this work a modular intelligent fixture system for flexible clamping of large parts is presented. The fixture modules consist of a hybrid material structure involving metal frame elements and mineral casting. These modules can be combined and connected to realize fixtures adapted to the geometry of the workpiece and requirements of the machining processes. By integrated pipes and interfaces, an internal hydraulic supply and active cooling is possible even for combined modules. Temperature and acceleration sensors allow for an active thermal control and process monitoring. The modules and first test fixtures are investigated in experiments.

Flexible fixturing for workpiece positioning and constraining

Flexible fixturing is an important aspect of any flexible manufacturing system (FMS) and computer integrated manufacturing (CIM) environment. The production analysis for fixturing within an FMS environment is presented. Various approaches to flexible fixturing are briefly described. The reconfigurable fixturing is one of the most appropriate flexible fixturing techniques for CIM environment. Reconfigurable and/or automated modular fixturing employs a number of fixture modules that are set up, adjusted and changed to form different fixture layout. The requirements for locating and constraining workpieces are presented. In addition, computer‐aided planning and analysis of fixture set up are discussed.

A CAD-Based hierarchical approach to interference detection among fixture modules in a reconfigurable fixturing system

A reconfigurable fixturing system has been developed for a computer-integrated assembly environment. The fixturing system employs a number of fixture modules which are set-up, adjusted and changed automatically by the assembly robot. A dedicated software program has been developed for the design, analysis, and verification of the fixture layout. The software program has been integrated with a commercially available computer-aided design (CAD) package to provide a user-friendly platform for modeling and display purposes. The robot program for setting up, adjusting, and dismantling the designed fixture is generated automatically. Interference between fixture modules during the fixture construction may arise due to incorrect selection of the fixture contact points at the design stage. The objective of the work described here is to develop a hierarchical approach for calculation of interference between fixture modules in a reconfigurable fixturing system. The formulation for the interference detection employs geometrical constraints as the basis. The approach does not require detailed simulation of the fixture construction for interference detection.

Experimental investigation of the performance of a reconfigurable fixturing system

A reconfigurable fixturing system has been developed for computer-integrated assembly environments. The fixturing system employs a number of fixture modules that are set-up, adjusted and changed automatically by the assembly robot without human intervention. A commercially available computer-aided design (CAD) package with the help of a dedicated software program is used for the design, analysis, and verification of the fixture layout. The robot program for setting-up, adjusting, and dismantling the designed fixture is generated automatically. This paper presents and discusses the accuracy of such a reconfigurable fixturing system in view of the off-line programming techniques. The experimental techniques to measure the accuracy and repeatability for setting-up the fixture are presented. The measured results of the robot positioning various types of locating fixture modules are presented and compared with the intended position settings. From the comparison, the accuracy that is to be expected from such an approach to fixturing and measures for improvement are discussed. The cycle times involved in setting-up the fixture modules are also presented and analysed. These results provide an initial guide for manufacturing industries interested in employing such systems in their computer-integrated assembly environment.

CAD-based design and analysis system for reconfigurable fixtures in robotic assembly

Fixturing is an important requirement for many manufacturing and assembly operations. If flexible manufacturing and assembly systems (FMS and FAS) are to be truly flexible, then the fixturing must also be flexible. This article presents a system for computer-aided design and analysis of reconfigurable fixtures in robotic assembly. The fixturing system employs a number of adjustable fixture modules that are set up, adjusted and changed automatically by the assembly robot without human intervention. The design of the fixture layout is performed interactively on a commercially available computer-aided design (CAD) package. The development of a dedicated software program to perform kinematic analysis of the fixture layout, using the information retrieved from the CAD database, is presented. A strategy to build various fixture layouts to locate and hold workpieces of various shapes and sizes using the same set of fixture modules is also presented.

An implementation of drive key cellular manufacturing

The drive key is one of the most important high-precision components of aircraft braking systems. In this paper, a cost effective drive keys manufacturing process is developed. This proposed manufacturing process makes use of near-net-shape manufacturing, computer numerical control (CNC) machining, and cellular manufacturing methods. To make the proposed process a reality, proper engineering with the proposed parts along with group technology are applied to the product design in conjunction with the proposed manufacturing methods. In addition, a general spreadsheet program is developed for each style of fixture modules to assist in part program coding. Moreover, statistical process control (SPC) is implemented to verify product quality and accept the product at the point of manufacture. It is observed that the implementation of the proposed drive key cellular manufacturing process results in a tremendous improvement in quality, throughput and productivity as well as a drastic reduction in manufacturing operations, workholding fixtures, cutting tools, and inspection media.

Issues in the design of the reconfigurable fixture modules for robotic assembly

Abstract Workpiece positioning and constraining is an important factor in manufacturing processes such as machining, welding, bonding, and assembly. Jigs and fixtures are devices employed to position and constrain the workpiece in a desired location to ensure that it is in a state of static equilibrium and that dimensional accuracy is maintained during the manufacturing operation. Traditionally, fixtures have been designed and manufactured as single-purpose devices for specific parts and manufacturing operations. The traditional approach is costly due to the long load time and effort required to design and manufacture special-purpose fixtures, manual set-up and change of fixtures, and overhead cost associated with storing and retrieving a multiplicity of fixtures. Thus, the traditional approach is not suited to the flexible manufacturing environment where production volume is low and product variation is high. If flexible manufacturing systems (FMSs) are to be truly flexible, then the fixturing must also be flexible. This paper presents requirements, design principles, design rules, and a prototype system for flexible fixtures in robotic assembly. Such a fixturing system would employ a number of fixture modules that are set-up, adjusted and changed automatically by the assembly robot without human intervention. The design of the fixture layout is performed interactively on a commercially available computer-aided design (CAD) package. The guidelines for development of a dedicated software program to automatically generate robot program for setting up, adjusting, and dismantling the fixture, using the information retrieved from the CAD database, is presented.

Issues in the design of the reconfigurable fixture modules for robotic assembly

Issues in the design of the reconfigurable fixture modules for robotic assembly