3D Hall Shift Fork Position Sensing Under Mechanical Play
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional linear sensors are inadequate for accurately detecting the position of pivoted shift forks in manual transmissions due to mechanical play and wear, leading to measurement errors and signal noise, especially when the actuator undergoes rotational movements.
Innovation Solution
A 3D Hall sensor system is used, where a magnet is attached to the shift fork or piston rod, allowing for precise detection of linear, rotational, and pivoting movements, eliminating the need for direct attachment to the shift fork and compensating for mechanical inaccuracies through spatial magnetic field detection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a conventional linear sensor is used to detect the position of a pivoted shift fork, then the sensor can be attached to a linearly moving actuator, but measurement errors occur due to mechanical play and wear between the actuator and shift fork
Solution Approach 1:
The patent replaces the conventional mechanical linear sensor system with a magnetic field-based detection system. A magnet is attached to the actuator, and a 3D Hall sensor detects the magnetic field position, eliminating the need for direct mechanical attachment between sensor and shift fork. This substitution removes the mechanical play and wear issues while maintaining ease of manufacture, as the magnet can be easily mounted on the actuator without complex mechanical linkages.
Solution Approach 2:
The patent introduces a magnetic field as an intermediary between the actuator and the sensor. Instead of directly measuring the mechanical position through contact, the system uses a magnet on the actuator to generate a magnetic field that the 3D Hall sensor detects. This intermediary allows indirect measurement that is immune to mechanical play and wear between components.
2Adaptability or versatility
If a linear sensor rotates relative to the receiver due to rotational movement of the piston rod, then the actuator can perform its full range of motion, but axial offset of the sensor signal from the actual shift fork position occurs
Solution Approach 1:
The patent transitions from a one-dimensional linear sensor to a three-dimensional Hall sensor that can detect magnetic field position in multiple dimensions. The 3D Hall sensor measures the magnet's position along the axial direction (x), radial direction (y), and rotational angle (z), allowing the system to compensate for rotational movements of the piston rod while maintaining accurate axial position detection of the shift fork.
3Measurement precision
If multiple linear sensors in several dimensions are used to detect the position of components, then spatial detection capability is improved, but device complexity increases
Solution Approach 1:
The patent combines multiple sensing functions into a single 3D Hall sensor component. Instead of using separate linear sensors for each dimension, the 3D Hall sensor integrates the detection of axial position, radial position, and rotational angle into one device. This merging maintains full spatial detection capability while significantly reducing system complexity compared to using multiple independent linear sensors.
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 solution provides improved measurement accuracy and reliability, reducing manufacturing costs by enabling direct and indirect position detection of shift forks, even with actuator wear, and preventing signal degradation from mechanical interference.
Implementation Method 1
a Hall sensor assembly (10) with a 3D Hall sensor (11) as signal receiver by means of which a magnetic field can be spatially detected
Data Source
Figure 1
Figure 2~3
AI summary
The invention relates to a device (30) having a Hall sensor apparatus (10) for sensing the position of a shift fork (7) in a transmission (1), the shift fork (7) being operatively connected to a piston rod (6) of a shifting piston (2), which shifting piston is guided for axial movement in a shifting cylinder (3), and the shift fork engaging in a sliding sleeve (8), which is arranged on a transmission shaft (9) for axially sliding, in order to slide the sliding sleeve (8) for the engagement or disengagement of a gear ratio level of the transmission (1). According to the invention, a magnet (13) is arranged as a signaling device on at least one of the following movable actuators: shifting piston (2), piston rod (6) or shift fork (7); a 3-D Hall sensor (11), which is arranged stationary relative to the magnet (13), is present as a signal receiver, by means of which a magnetic field produced by the magnet (13) can be spatially sensed; the 3-D Hall sensor (11) is connected to an electronic control unit (31); and the control unit (31) is designed in such a way that, by means of the control unit, the current position of the shift fork (7) can be determined from the relative position between the magnet (13) and the 3-D Hall sensor (11) and can be provided as a signal, linear motions, rotational motions and/or pivoting motions of the actuator (2, 6, 7) in question being able to be taken into consideration.