Metal Stamping Draw-in Sensor
- Detailed Technology Description
- Northwestern researchers have invented a device to monitor process quality for sheet metal fabrication. The invention, made from printed-film technology, measures the so-called 'draw-in' at points on the periphery of a sheet metal blank during press stroke. Such monitoring is especially important in automotive and aerospace manufacturing.
- *Abstract
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The solution is sensitive to complex geometries. It is non-invasive (non-contacting), very easy to apply, extremely rugged, and inexpensive (and possibly disposable). This invention overcomes the following deficiencies of the current methods to monitor draw-in :
- Current methods are inadequate for complex geometries.
- Current methods are invasive. As a result, intricate tool modification or additional setup time is required, and parts are subject to damage.
- Current methods are expensive to apply.
Sheet metal forming is one of the predominant processes in the manufacture of automobiles (about 300 parts per vehicle), and is also widely employed in the manufacture of aircraft, appliances, beverage cans and many other products. As the automotive industry replaces sheet steel with high-strength and low-weight materials like aluminum, the industry must face the increased challenge of wrinkling and tearing of the sheet metal. The edges of a sheet metal blank move inward as a press forms the blank into a part, and the amount by which the blank moves in the press is referred to as "draw-in" (See Fig. 1). It is important to measure and control the amount of draw-in at several points around the circumference of a part, because too little draw-in can tear a part, and too much draw-in can wrinkle the part. With more complex geometries implemented in the automotive industry, draw-in becomes especially difficult to measure and control around the periphery of a part.
R&D groups would apply the sensor to test tool performance, and quality control and production engineers would apply the sensor to monitor and control production performance on a real-time basis (Real-time production control of sheet metal forming is especially important if sheet metal properties vary among production lots).
The invention and its implementation are shown in Figures 1 and 2 below.
- *Inventors
- Jian CaoJung-Hoon LeeMichael A. Peshkin
- *Stage of Development
- The sensor has been lab tested, and results demonstrate linear relationships between sensor output and draw-in at points around the periphery of a sheet metal blank. U.S. Patent No. 6,769,280 has been issued and Northwestern seeks partners to further engineer and distribute this invention.
- Country/Region
- USA
