Force Sensor With Non-Uniform Rigidity For Strain Sensitivity
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing force sensors face challenges in effectively flexing the area where strain gauge elements are formed while preventing the pressure receiving portion from damage due to overload, particularly in terms of strain detection sensitivity and load bearing properties.
Innovation Solution
A force sensor design featuring a pressure transmission member with a first region of lower rigidity and a second region of higher rigidity, where the strain gauge element is located near the boundary between the two regions, allowing preferential compression and stress concentration for enhanced strain detection, and a pressure receiving member with higher rigidity to prevent damage from external forces.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If the pressure transmission member is made with high rigidity throughout, then the load bearing property is improved, but the strain detection sensitivity deteriorates because the member cannot flex sufficiently to generate stress concentration at the strain gauge element
Solution Approach 1:
The pressure transmission member is designed with non-uniform rigidity distribution, featuring a first region with relatively low rigidity and a second region with relatively high rigidity. This local differentiation allows the low rigidity first region to flex and generate stress concentration at the strain gauge element location, while the high rigidity second region maintains overall structural strength and load bearing capacity.
2Measurement precision
If the pressure transmission member is made with low rigidity to enhance strain detection, then the strain detection sensitivity is improved, but the load bearing property deteriorates because the member cannot withstand overload
Solution Approach 1:
The pressure transmission member incorporates a first region with relatively low rigidity positioned at the strain gauge element location to enhance flexibility and strain detection sensitivity, while a second region with relatively high rigidity is provided elsewhere in the member to maintain overall structural strength and prevent damage from overload or impact.
3Device complexity
If the strain gauge element is positioned in the center of the pressure transmission member, then the structural simplicity is improved, but the strain detection sensitivity deteriorates because stress concentration is reduced
Solution Approach 1:
The strain gauge element is positioned to face the boundary between the first low rigidity region and the second high rigidity region, rather than being centered. This positioning exploits the stress concentration effect that occurs at the interface between regions of different rigidity, significantly enhancing strain detection sensitivity while maintaining relatively simple structure.
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 enhances load bearing properties and strain detection sensitivity by guiding stress to the strain gauge element efficiently, while preventing damage to the pressure receiving portion from overloads, thereby improving the overall performance of the force sensor.
Implementation Method 1
a sensor board disposed on the other side of the pressure transmission member in the first direction and having rigidity higher than the pressure transmission member. The sensor board includes a strain gauge element on a side facing the pressure transmission member
Data Source
AI summary
A force sensor includes a pressure transmission member having, at an end on one side in a first direction, a pressure receiving portion that receives a force to be detected and a sensor board disposed on the other side of the pressure transmission member in the first direction and having rigidity higher than the pressure transmission member. The sensor board includes a strain gauge element on a side facing the pressure transmission member. The pressure transmission member has a first region having a relatively low rigidity and a second region adjacent to the first region as viewed in the first direction and having a relatively high rigidity. The second region has a contact portion in contact with the sensor board. The strain gauge element is located in the vicinity of a boundary of the first region with the second region.