Progressive and Compound Forming for Producing Plunger-Typed Microparts by Using Sheet Metal

The plunger part in temporary electronic connectors is traditionally fabricated by micromachining. Progressive forming of microparts by directly using sheet metals is developed and proven to be an efficient microforming process to overcome some intrinsic drawback in realization of mass production of microparts. By employing this unique micromanufacturing process, an efficient approach with progressive microforming is developed to fabricate plunger-shaped microparts. In this endeavor, a progressive forming system for making microplungers using extrusion and blanking operations is developed, and the grain size effect affected deformation behaviors and of surface qualities of the microformed parts are studied. The knowledge for fabrication of plunger-shaped microparts via progressive microforming is developed, and the in-depth understanding and insight into the deformation behaviors and tailoring the product quality and properties will facilitate the design and development of the forming process by using this unique microforming approach.

Application of the Progressive Forming Method in Simulation and Experimental Study of Rectangular Fins in a Heat Exchanger

A progressive forming method is applied where stamping is continuously executed to produce the rectangular fins of the plate fin heat exchanger. This process produced the fins one-by-one instead of by bundles. In order to produce a fin having a depth of more than 6.0 mm, the forming load and effective stress according to the size of the edge radii of punch and die are predicted by forming simulation. Furthermore, the process of forming the second, as well as the third, fins is predicted. As the edge radii of the die and those of the punch became smaller, the effective stresses generated during deformation became smaller. The forming load during deformation also became smaller. The sizes of the edge radii of die and punch were set to 0.5 mm and 0.2 mm, respectively. When the second fin was formed, overforming occurred at the ribs. The punch was therefore modified so that the rib could be compressed at the same time the fin was formed. With the designed process, the inner fins close to the target size could be manufactured. The resulting fins had right-angled ribs, although the fin width was a slightly opened isosceles trapezoid due to the spring-back.

Positional Accuracy Based on a Load Identification Optimization on a Linear Motor Sheet Forming Feeder

Precision feeding is essential for micro-stamping, especially in multi-stage progressive forming operations, where necessary feeding rates also have to be maintained. Research in micro-stamping of thinner sheet metals (<100 microns) led to investigations of the performance of existing sheet-metal feeders, regarding their accuracy and repeatability in high speed micro-stamping. The results indicated that the pursuance of higher feeding accuracy and repeatability which aimed at 5-15% of the strip thickness was unachievable with the existing micro-feeders. A new high-precision and high-speed feeder was, therefore, developed for micro-sheet-forming. Initial non-optimized experimental results had showed high accuracy and repeatability were achieved.

Drawing Progressive Die Design for Shell Parts

The deep drawing progressive forming process was analyzed by introducing the drawing progressive die design of shell parts. The drawing progressive design, layout design and mold structure was described detailedly.