PWM electromagnetic valve with selective case hardening
US4796855A · kind A · utility
10Cited by
2References
4Claims
0Family size
Assignee
Inventor
Key dates
| Filing date | Mar 15, 1988 |
| Grant date | Jan 10, 1989 |
| Priority date | — |
| Expiry date | Mar 15, 2008 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF16K31/0655
- WIPO fieldMechanical elements
- WIPO sectorMechanical engineering
Abstract
The armature and active seat of an electromagnetic PWM valve are selectively case hardened at their contacting surfaces to a case depth of approximately 0.50 mm. The hardened areas provide hard contacting surfaces for superior durability, and moreover, create an effective air gap between the armature and the active seat to substantially prevent residual magnetism therebetween. The remaining surfaces of the armature and seat assembly are not hardened, and serve as a low reluctance magnetic flux path around the hardened areas.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.