Automotive Shaft Production Lines Get a New Noncontact CNC Gaging System
Detroit Precision Tool Co (Detroit, MI) has combined length and roundness measurement with a digital image projector to produce a new optical CNC shaft gaging system that can inspect up to 150 different features in less than a minute.
"With no practical limit to the number or the size of features that can be measured, our systems offer shaft manufacturers a highly flexible, cost-effective, high-accuracy, and high-speed measurement tool that can confirm production quality instantly," explains John Sattmann, Detroit Precision VP.
Contour, diameters, length, roundness, concentricity, cones, angles, flatness, parallelism, eccentricity, stroke, and threads can be recorded in submicron detail during a single pass of the optical measuring head. The gages, driven by Windows NT measuring software, provide a new alternative to conventional shaft measuring techniques that is faster, more accurate, and more complete, says Sattmann.
Designed for production lines or cells
The CNC gaging system is designed for production lines or cells where it can reduce machine qualification times while providing the ability to assure 100% quality control within the machining cycle. In Europe the gaging system has been accepted in the automotive industry where in one application the system is checking 32 valve features in one second.
There are two models available, the AMV and WMS CNC measuring systems. Both are adaptable to manual, semi-automatic, or fully automatic gaging, in horizontal or vertical configurations. The narrow-profile AMV is more suited to integration within the manufacturing process, while the WMS is suited for stand-alone operation and universal measuring.
The fully flexible shaft gaging systems accommodate a wide range of shaft sizes from 0.2mm to 270mm diameter, 1mm to 1500mm long with measuring accuracies to ±1µm. Filters are used to assure highly reliable measuring results and to eliminate sources of error, including dirt and swarf.
Measuring times matched to production rates
CNC eliminates changeover time from one part to another and measuring times can typically be matched to production rates. Manufacturing checks, automatic tool correction, initial sample measurement, machine setup, are typical applications for this family of versatile gages.
The measurement and analysis software, consisting of about 150 measurement modules for a range of measuring functions, is simple to program, says Sattmann. "A measuring program can be assembled from function macros, so repeated measuring tasks can be accomplished very quickly. Flexible design of the measurement modules, the consistent use of common standards, the measurement technology, and the use of standard operating systems make it possible to create the optimum solution for each application," he explains.
Noncontact CNC gaging at work
In operation, the workpiece is clamped into the gage between centers. A rotary drive with integral angular encoder is located in the headstock. A measuring slide, consisting of a camera with CCD diode lines opposite a high-power LED (light source), travels axially along the shaft, registering digitally up to 2000 measurements per second.
Profiles of the workpiece are reflected onto the diode lines, and an image-processing system analyzes longitudinal and rotational measurement data. This information is converted to X/Y measurements, the angle of rotation is included to assess deviations in shape, and measurement results are then documented or used to instantly correct the manufacturing process.
Once the workpiece has been scanned, a part profile is displayed on the large CRT at which point the part may be analyzed, documentation can be output, and data can be stored and graphed for later reference or transferred.
Detroit Precision Tool Company is a leading designer and builder of automated gaging solutions. It provides inspection, certification, and calibration services through its ISO 9001-certified Metrology Services division.
Detroit Precision Tool Company, 1505 Hamlin Road, Rochester Hills, MI 48309; phone: 248-853-5888