tailieunhanh - Ebook Flexible manufacturing system: Part 2

(BQ) Part 2 book "Flexible manufacturing system" has contents: Coordinate measuring machine, automated material movement and storage system, cutting tools and tool management, system hardware and general functionality, FMS installation and implementation, and other contents. | 52 Flexible Manufacturing System 7 Coordinate Measuring Machine INTRODUCTION Traditional measuring instruments can provide excellent solutions for the measurement of features such as length, height, width, inside and outside diameters, flatness, roundness, angles, and so on. The problem with traditional measurement techniques is that each measured feature may require individual inspection instruments and individual setups, as well as allowing for increased human error. A coordinate measuring machine (CMM) can fill a valuable role in precision measuring because a surface plate, height gage and indicator inspection procedure are combined to provide a fast, accurate and more convenient alternative to the conventional methods for measuring complex parts. The CMM can also be fully automated and linked to a CAD system as well as used to measure and verify Geometric Dimensioning and Tolerancing (GD&T) call outs. It seems that CMMs offer the answer to all our dimensional measurement problems, but is that really true? Will we get precisely the same results as the traditional methods? Measurement with a CMM is a complex process that requires the right training and interruption of data collected. Coordinate measuring machine is an electromechanical system designed to perform coordinate metrology. Coordinate metrology is concerned with the measurement of the actual shape and dimensions of an object and comparing these with the desired shape and dimensions, as specified by the part drawing. CMM evaluates the location, orientation, dimensions, and geometry of the part or object. A CMM consists of a contact probe that can be positioned in 3-D space relative to the surfaces of a work part. The x, y and z coordinates of the probe can be accurately and precisely recorded to obtain dimensional data concerning the part geometry (See the Fig. ). Coordinate Measuring Machine 53 y Mechanical structure Probe head z Work table Computer system x Probe Fig. Coordinate .