Vacuum booster apparatus and a brake apparatus
US6412883B1 · kind B1 · utility
Assignees
Inventors
Key dates
| Filing date | Jan 16, 2002 |
| Grant date | Jul 2, 2002 |
| Priority date | — |
| Expiry date | Jan 16, 2022 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB60T13/72
- WIPO fieldTransport
- WIPO sectorMechanical engineering
Abstract
A vacuum booster apparatus used for a brake apparatus positively decreases a degree of opening of a throttle valve when it is required while an unnecessary decrease in the degree of opening of the throttle valve is positively prevented. A first pressure chamber of a vacuum booster is connected to an intake pipe of the engine on a downstream side of a throttle valve. A second pressure chamber of the vacuum booster is selectively connectable to one of the first pressure chamber and atmosphere. The vacuum booster boosts an operating force applied to a brake operating member based on a pressure difference between the first pressure chamber and the second pressure chamber. A throttle-opening-degree control device controls a negative pressure in the first pressure chamber by controlling the degree of opening of the throttle valve. The throttle-opening-degree control device decreases the degree of opening of the throttle valve only for a limited time when the negative pressure in the first pressure chamber is smaller than a predetermined necessary negative pressure determined by an operating-force relating amount related to the operating force applied to the brake operating member.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.