Hall Effect Sensor Mandrel Distance Sensing Assembly
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Solution Overview
Problem
Conventional electric rivet guns face inaccuracies in controlling the linear distance of the mandrel-pulling mechanism due to variations in motor rotational speeds and accumulation of impurities, affecting the positioning of the snapping device.
Innovation Solution
A mandrel-pulling distance sensing assembly featuring a Hall effect sensor and magnetic elements within the electric rivet gun's barrel, which detects changing magnetic fields to accurately control the motor and position the snapping device.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If the linear distance is controlled by setting the number of rotations of the motor's rotating shaft, then the motor structure can be simplified, but the positioning accuracy of the snapping device deteriorates due to variations in rotational speed and gear wear
Solution Approach 1:
The patent replaces the mechanical positioning method (counting motor rotations through gear sets) with a magnetic sensing system. Hall effect sensors detect the position of magnets attached to the moving seat, providing accurate position feedback without relying on mechanical gear teeth or rotation counting. This substitution eliminates the accumulation of positioning errors caused by gear wear and rotational speed variations.
Solution Approach 2:
The patent implements a feedback mechanism where Hall effect sensors continuously detect the position of the moving seat via magnets and provide real-time position information to the control unit. The control unit adjusts the motor operation based on this feedback to maintain the moving seat within the predetermined range, compensating for any positioning deviations.
2Measurement precision
If photo interrupters are used to control the moving range, then the positioning can be achieved, but the accuracy deteriorates due to mounting offsets and light projection angle variations
Solution Approach 1:
The patent replaces the optical sensing system (photo interrupters) with a magnetic sensing system. Magnets are fixed to the moving seat and detected by Hall effect sensors mounted on the stationary seat. This magnetic field-based detection is not affected by mounting offsets or light projection angles, providing more stable and accurate position detection.
Solution Approach 2:
The patent introduces magnets as an intermediary between the moving seat and the Hall effect sensors. These magnets create a magnetic field that serves as the detection medium, replacing the light field used by photo interrupters. The magnetic field is less susceptible to environmental interference and mounting variations compared to light.
3Device complexity
If the snapping device moving range is controlled by motor rotation control, then the control mechanism can be simplified, but the reliability deteriorates due to gear tooth wear and impurity accumulation
Solution Approach 1:
The patent replaces the mechanical control mechanism (motor rotation through gear sets) with a magnetic field-based sensing and control system. Hall effect sensors detect magnet positions without mechanical contact, eliminating wear and impurity accumulation issues. The control mechanism remains relatively simple while significantly improving reliability.
Solution Approach 2:
The patent implements continuous position feedback using Hall effect sensors that monitor the moving seat's position in real-time. The control unit receives this feedback and adjusts motor operation accordingly, ensuring the moving seat remains within the predetermined range even after long-term use, thereby maintaining high reliability.
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
Ensures precise control over the moving range and positioning of the snapping device, enhancing the accuracy of mandrel-pulling operations by using the Hall effect sensor to output changing voltages for motor control.
Implementation Method 1
A Hall effect sensor is securely fixed on the moving seat and moves along with the moving seat between the two magnetic elements. While the Hall effect sensor on the moving seat moves between the magnetic element that is positioned toward the front end of the barrel and the magnetic element that is positioned toward the rear end of the barrel, the Hall effect sensor detects a changing magnetic field and produces and outputs a changing voltages to a control unit
Data Source
AI summary
A mandrel-pulling distance sensing assembly of an electric rivet gun is mounted in a barrel of a housing and has a stationary seat, a moving seat, two magnetic elements separately fixed on the stationary seat, and a Hall effect sensor fixed on the moving seat. The moving seat is driven by a driving assembly of the electric rivet gun and is movable relative to the stationary seat. While the Hall effect sensor moves along with the moving seat between the two magnetic elements, the Hall effect sensor detects a changing magnetic field and produces and outputs a changing voltages to a control unit to allow the control unit to operate the driving assembly according to the changing voltages. Thus, the moving seat can be accurately positioned and moving ranges of a snapping device that is driven by the driving assembly can be accurately controlled.