| 摘要 |
PURPOSE:To prevent that a prescribed output of the title meter is not attained due to body vibration and to prevent the performance from being deteriorated by rain water and dust by cutting out a part of a magnetic ring body of a rotor in the generater for bicycle detecting a leaking magnetic flux, and measuring a revolution speed of a wheel. CONSTITUTION:Five pieces of an anisotropic magnet armature 2 magnetized in N pole and S pole alternately in the direction of the thickness are arranged annularly in a rotor 1 for the generater A for the bicycle, its outer periphery is covered with a magnetic ring body 3 being the same width as the anisotropic magnet armature 2 and adhered integrally, then the notch part 3 is formed in its one part. Accordingly, when the wheel is revolved, as a sensor 24 detects the leaking magnetic flux from the notch part 3a every one revolution, a detecting signal from the sensor 24 is led to a well-known speed meter mounted at a handle, thus measuring and displaying a speed of the bicycle. By this method, it is possible to exactly measure for a long period in such a state that a gap and angle for the sensor 24 are not get out of order by the body vibration, and the performance is never deteriorated by the penetration of rain water and dust. |
