Throttle grip device using magnet
Provided is a throttle grip device that can stably generate an operation feeling and achieves downsizing itself. A throttle grip device includes a throttle grip attached to a handlebar, an accelerator position sensor, and a return spring. The accelerator position sensor and the return spring are accommodated inside the handlebar so as to be arranged tandemly along a straight line. The accelerator position sensor includes a cylindrical inner rotor in which a plurality of magnetic poles is magnetized along a circumferential direction, a magnetic material-made outer case configured to accommodate the inner rotor, and a sensor IC disposed facing a sensor side end of the inner rotor and offset from a central axis of the inner rotor. The inner rotor rotates in conjunction with the throttle grip.
1. A throttle grip device comprising:
a throttle grip attached to a cylindrical handlebar so as to be rotatable around a central axis thereof;
a return spring configured to urge the throttle grip to return to its initial position; and
an accelerator position sensor,
wherein:
the accelerator position sensor and the return spring are accommodated inside the handlebar so as to be arranged tandemly along a straight line;
the accelerator position sensor includes a magnet extending along the central axis, a cylindrical member made of a magnetic material accommodating the magnet, and a magnetic sensor disposed to face an end of the magnet;
in the magnet, a plurality of magnetic poles is magnetized along a rotation direction around the central axis;
the magnet is configured to rotate in conjunction with the throttle grip;
each part in the cylindrical member is magnetized to a magnetic pole opposite to each magnetic pole of the opposing magnet; and
when the magnet rotates relative to the cylindrical member, each part of the magnetized cylindrical member generates a magnetic force to inhibit a rotation of the magnet.
2. The throttle grip device according to claim 1 , wherein the magnetic sensor is disposed offset from a central axis of the magnet.
3. The throttle grip device according to claim 1 , wherein a rotation angle of the throttle grip which needs to be detected is smaller than an angle formed by two adjacent magnetic poles in the magnet around a central axis of the magnet.
4. The throttle grip device according to claim 1 , wherein the magnet is arranged with respect to the cylindrical member such that the number of boundaries of the magnetic poles within a range of a rotation angle of the throttle grip which needs to be detected is two or less.
5. The throttle grip device according to claim 1 , wherein an end of the magnet facing the magnetic sensor protrudes from the cylindrical member.
6. The throttle grip device according to claim 1 , wherein an end of the magnet which is located at the opposite side of an end of the magnet facing the magnetic sensor is covered by the cylindrical member.
7. The throttle grip device according to claim 1 , wherein the magnetic sensor and the magnet overlap each other when the magnet is seen along the central axis.
8. The throttle grip device according to claim 1 , wherein the magnetic sensor has either one of a Hall element, a magnetoresistive element, a magneto-impedance element, or a superconducting quantum interference device.
9. The throttle grip device according to claim 1 , wherein the magnet has a cylindrical shape extending along the central axis.
10. The throttle grip device according to claim 1 , wherein the magnet has a round bar shape extending along the central axis.