Bi-fold valve-type magnetorheological fluid energy absorbing device

US7900755B2 · kind B2 · utility

Assignee

• GM GLOBAL TECHNOLOGY OPERATIONS LLC · US

Inventors

• Alan L. Browne · Grosse Pointe, US
• John C. Ulicny · Oxford, US
• Chandra S. Namuduri · Troy, US
• Nancy L. Johnson · Northville, US
• Norman M. Wereley · Potomac, US
• Young-Tai Choi · Laurel, US
• Wei Hu · Zhejiang, CN
• Min Mao · Tangxia, CN

Key dates

• Filing date: Sep 28, 2007
• Grant date: Mar 8, 2011
• Expiry date: Jun 16, 2029

Classification

• Technology area (CPC F): Mechanical Engineering; Lighting; Heating
• CPC primary: F16F9/537
• WIPO field: Mechanical elements
• WIPO sector: Mechanical engineering

Abstract

An energy absorbing device is provided that includes a damper assembly having inner and outer concentric tubes and a piston movable within the inner tube. The damper assembly is configured to form bi-fold valve-type cavities to operatively connect an inner chamber of the inner tube with an outer chamber formed between the inner and outer tubes. A magnetorheological fluid fills the chambers and the bi-fold valve-type cavities. The magnetorheological fluid preferably contains coated magnetic particles at about 10 to 60 percent by volume. Electrical coils adjacent the bi-fold valves are selectively energizable to such that the energy absorbing device provides a tunable damping force, preferably over the entire range of velocities of the piston, especially in automotive applications.