Torque Sensor Collector Fixation via Thermal Fusion
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional torque index sensors used in Electronic Power Steering systems face reliability issues due to loosening of the collector and housing coupling at high temperatures, leading to measurement errors, especially when using adhesives like double-sided tape or adhesive, which fail to secure the collector effectively.
Innovation Solution
A torque index sensor design featuring a housing with protrusively formed fixing bosses that are thermally fused through holes in the collector, ensuring a secure and stable fixation of the collector to the housing, even at elevated temperatures, thereby preventing disengagement and maintaining accurate magnetic flux guidance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If adhesive (double-sided tape) is used to secure the collector, then the collector can be fixed to the housing, but the coupling loosens at high temperatures (80°C-120°C) causing measurement errors
Solution Approach 1:
The patent replaces the adhesive-based mechanical fixation system with a thermal fusion system. The fixing boss is heated to melt the adhesive material, transforming the weak adhesive bond into a strong thermally-fused connection that maintains its integrity at high temperatures (80°C-120°C), thereby resolving the temperature-reliability contradiction.
Solution Approach 2:
The patent changes the physical state and temperature parameters of the adhesive material during assembly. By heating the fixing boss to a specific temperature range, the adhesive transitions from a bonded state to a melted state, then solidifies into a permanent fusion. This parameter change enables the collector to remain securely fixed even during high-temperature operation.
2Ease of manufacture
If the collector is loosely secured, then assembly is easier, but the distance between collector and housing becomes uneven generating sensor measurement errors
Solution Approach 1:
The patent performs preliminary action by pre-forming the fixing boss protrusion on the housing before assembly. This pre-formed structure guides the collector into the correct position during assembly, ensuring proper alignment and distance control. The thermal fusion process then locks this pre-established correct position, preventing measurement errors while maintaining ease of assembly.
Solution Approach 2:
The fixing boss acts as an intermediary element between the housing and collector. It provides a controlled interface that transfers and distributes the bonding force uniformly, ensuring even distance maintenance. The thermal fusion of the fixing boss creates a stable intermediary connection that prevents the collector from shifting position, thereby maintaining measurement precision.
3Ease of manufacture
If conventional adhesive fixation is used, then the sensor can be assembled, but the coupling fails under high temperature conditions leading to erroneous operations
Solution Approach 1:
The patent replaces the conventional adhesive fixation system with a thermal fusion system. The fixing boss is heated to melt the adhesive material, transforming the weak adhesive bond into a strong thermally-fused connection that maintains its integrity at high temperatures (80°C-120°C), thereby resolving the temperature-reliability contradiction.
Solution Approach 2:
The patent utilizes phase transitions of the adhesive material to achieve reliable fixation. The adhesive transitions from solid (during assembly) to liquid (during thermal fusion) and then back to solid (during curing), creating a permanent bond. This phase transition process enables the collector to remain securely fixed even during high-temperature operation, solving the reliability issue.
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
The solution enhances product reliability by maintaining a consistent collector position and magnetic field alignment, ensuring precise measurements over time, even under high-temperature conditions, thus improving the overall performance and stability of the torque index sensor.
Implementation Method 1
the fixing boss is thermally fused after passing the through hole to tightly fix the collector at an inner surface of the housing
Data Source
AI summary
Disclosed is a torque index sensor, the sensor including a housing, a stator mounted at a space inside the housing, a magnet arranged inside the stator to rotate with a rotation shaft, a PCB (Printed Circuit Board) fixedly mounted inside the housing and mounted with a first magnetic element outputting a magnetization signal in response to rotation of the magnet, at least one or more fixing bosses protrusively formed at the housing, and a collector having a plurality of through holes penetratively formed at a position corresponding to that of the fixing boss and concentrating a magnetic field for guiding a magnetic flux of the magnet, wherein the fixing boss is thermally fused after passing the through hole to tightly fix the collector at an inner surface of the housing.