Axial Magnetic Sensor for Motorcycle Throttle Detection
Solution Overview
Problem
Conventional throttle opening detection devices for motorcycles are limited in layout flexibility and size due to the radial arrangement of magnetic sensors, which restricts miniaturization and increases device size.
Innovation Solution
The magnetic sensor is arranged axially opposed to the rotor, with magnets positioned near the rotor's end surface and spaced apart in the circumferential direction, allowing for a more compact design and improved linear correlation between rotational angle and magnetic flux density.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the magnetic sensor is arranged outside the rotor in the radial direction, then the magnetic flux density correlation with rotational angle becomes linear and detection accuracy is improved, but the device size increases and layout flexibility is reduced
Solution Approach 1:
The patent transitions the magnetic sensor arrangement from the radial direction to the axial direction of the rotor. This dimensional change allows the sensor to detect magnetic flux density variations while positioned within the rotor structure, thereby reducing the device's radial size while maintaining detection functionality through the axial positioning of the sensor relative to the magnets on the rotor end surface
2Measurement precision
If the magnetic sensor is arranged outside the rotor in the radial direction, then the magnetic flux density correlation with rotational angle becomes linear and detection accuracy is improved, but the degree of freedom in layout arrangement is decreased
Solution Approach 1:
By repositioning the magnetic sensor from a radial arrangement to an axial arrangement relative to the rotor, the patent creates additional spatial freedom. This allows the sensor to be integrated within the rotor structure, enabling more flexible layout options for surrounding components while preserving the linear correlation between magnetic flux density and rotational angle through proper positioning of the sensor facing the rotor end surface
3Volume of moving object
If magnets are arranged adjacent to each other along the circumferential direction near the rotor end surface, then the axial arrangement of the magnetic sensor is enabled and device size is reduced, but the magnetic flux density distribution must be optimized to maintain linear correlation
Solution Approach 1:
The patent applies local quality by positioning the magnets in specific locations on the rotor end surface and configuring them with particular polarities (alternating N and S poles) to create an optimized magnetic flux density distribution in the axial direction. This localized arrangement ensures that the magnetic field varies linearly with rotational angle when detected by the axially positioned sensor, thereby maintaining detection accuracy while enabling the compact axial configuration
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This configuration reduces the device's radial size, enhances layout flexibility, and enables accurate evaluation of throttle opening with high sensitivity and detection accuracy.
Implementation Method 1
a magnetic sensor which detects a magnetic force generated by the magnets
Data Source
AI summary
A throttle opening detection device includes a rotor which is rotated in an interlocking manner by manipulation of an acceleration grip which is mounted together with the rotor on a handlebar. First magnets are arranged near a peripheral portion of one side surface of the rotor along the circumferential direction of the rotor, while second magnets are respectively laminated to the first magnets, and have opposite polarities to the first magnets. The first magnets with the second magnets laminated thereto are disposed with a set spacing therebetween. A magnetic sensor for detecting a magnetic force generated by all the magnets is arranged to oppose, with a clearance therebetween, the one side surface of the rotor in which the magnets are arranged, in an axial direction of the rotor.