Variable reluctance sensor with offset magnets having improved magnetic
flux member
    1.
    发明授权
    Variable reluctance sensor with offset magnets having improved magnetic flux member 失效
    具有改进的磁通构件的偏移磁体的变量传感器

    公开(公告)号:US5236518A

    公开(公告)日:1993-08-17

    申请号:US836634

    申请日:1992-02-14

    IPC分类号: G01P3/488 H01F1/14

    CPC分类号: H01F1/14 G01P3/488

    摘要: A means is provided for improving the magnetic permeability of a magnetic circuit within a variable reluctance sensor having off-set, permanent magnets by appropriately annealing the magnetic flux member. The annealing process includes heating the machined magnetic flux member in a vacuum to a temperature and for a duration sufficient to austenitize the magnetic steel so that full carbide solution is obtained, for example about 1300.degree. F. to about 1550.degree. F. for a duration of about 15 to 30 minutes. The magnetic flux member is then appropriately cooled in the vacuum so as to prevent the formation of martensite. The magnetic circuit, incorporating the annealed magnetic flux member, exhibited improved magnetic permeability, and the sensor signal was increased by as much as about 60 percent during operation. The method of this invention enhances the overall effectiveness of the sensor, particularly when sensing low rotational speeds such as when employed within automotive anti-lock braking or traction control systems.