Method and apparatus for vacuum die casting
US5511605A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jul 7, 1994 |
| Grant date | Apr 30, 1996 |
| Priority date | — |
| Expiry date | Jul 7, 2014 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB22D17/32
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
A vacuum-controlling system for controlling the degree of vacuum in the vacuum system of a vacuum die-casting machine operates to: detect the degree of vacuum H at the instant of closure of the vacuum valve to the die mold cavity; compare the detected degree of vacuum H with a preset degree of vacuum Ho; correct a first position of the injection plunger for opening the vacuum valve by moving the first position in the advancing direction of the plunger by a specific distance in the case where H is higher than Ho; and correct the first position in the retracting direction of the plunger by a specific distance in the case where H is lower than Ho. By thus automatically correcting the position of the plunger for opening the vacuum valve to the optimum state, the formation of cavities or blowholes in the die-cast product is prevented, and at the same time, by maintaining the degree of vacuum in a specific state, the product quality is stabilized.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.