A Strengthening Method for Metal Parts

Author:  Teiji Suzuki and Tadao Sugano, C/o Honda Engineeri
Source:  Patent, H6-217214
Doc ID:  1996127
Year of Publication:  1996
Abstract:  
Honda Engineering, a subsidiary in the Honda group, has developed a new processing technology for improving gear strength using water jets. The new technology increases strength by 25% or more, and treated gears have lives ten times longer than untreated gears. Honda will introduce the technology into a manufacturing plant in December and plans to open the process to outside sale from 1997. The new process will allow transmissions to be made smaller while preserving gear strength. It involves heating the gears to about 900 deg C then immediately cooling them. It then uses water jets instead of air as in conventional methods. Also, instead of using copper balls, which can scar the surface, the technology uses glass beads. -------------------------------------------- [Purpose] To improve surface smoothness and fatigue strength and to easily increase working efficiency. [Structure] A mixture of water 16 and glass beads 20 is injected toward the bottom 30, of a gear 24 that has been machined by gear cutting. Therefore, glass beads 20 are injected toward gear tooth bottom (land) 30 with directivtiy. Compression stress is thus provided to the surface of gear tooth bottom (land) 30 and the surface is polished by these glass beads 20 and water 16.