Sensor Module Hermetic Sealing via Mechanical Pressing
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Solution Overview
Problem
Existing force sensors face issues with dimensional errors leading to gaps and leaks, making accurate force detection challenging, especially in outdoor environments, and complicating mass production due to complex welding processes.
Innovation Solution
A sensor module design where the sensor element is sealed within a first member and pressurized by a projection from the second member, allowing for consistent pressure application despite manufacturing fluctuations, and featuring adjustable fastening forces and thin sections for efficient stress distribution and hermetic sealing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If welding is used to seal the sensor element, then hermetic sealing is achieved, but manufacturing complexity increases and mass production becomes difficult
Solution Approach 1:
The patent replaces the welding process (thermal/mechanical system) with a mechanical pressing system. A pressing member with a pressing section applies mechanical pressure to deform the first member, creating hermetic sealing through controlled deformation rather than welding. This substitution eliminates the complex welding process while achieving the same sealing reliability.
Solution Approach 2:
The patent changes the sealing mechanism from a thermal-chemical process (welding) to a mechanical deformation process. By controlling the deformation amount of the first member through the pressing member, the patent achieves hermetic sealing through parameter control (deformation amount) rather than through welding parameters, simplifying the manufacturing process.
2Reliability
If dimensional errors occur in manufacturing, then gaps are formed and moisture intrusion occurs, but using tighter tolerances increases manufacturing cost and complexity
Solution Approach 1:
The patent applies preliminary deformation to the first member through the pressing member before final assembly. By pre-deforming the first member to create an interference fit or pre-compression state, the patent compensates for potential dimensional errors and prevents gap formation, ensuring hermetic sealing without requiring extremely tight manufacturing tolerances.
Solution Approach 2:
The patent creates a cushioning effect by deforming the first member in advance. The deformation of the first member absorbs dimensional variations and creates a compliant sealing interface that accommodates manufacturing tolerances, preventing moisture intrusion without requiring high-precision manufacturing.
3Measurement precision
If the sensor element is pressurized to improve detection accuracy, then measurement precision improves, but the sensor element may be damaged due to dimensional errors
Solution Approach 1:
The patent applies pressure locally and controllably through the pressing member. The pressing section of the pressing member concentrates the deformation force on specific areas of the first member, allowing controlled local deformation that applies necessary pressure for accurate measurement without excessive force that could damage the sensor element.
Solution Approach 2:
The patent creates a dynamic, adjustable pressing mechanism that can control the deformation amount. The pressing member allows for controlled, progressive deformation of the first member, enabling optimization of the pressure applied to achieve accurate measurement while preventing excessive pressure that could damage the sensor element.
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 design ensures accurate and reliable force detection across three-axis directions, maintaining high detection accuracy and enabling stable operation in various environments, including those exposed to moisture, while simplifying the manufacturing process.
Implementation Method 1
the sensor element includes two piezoelectric bodies laminated in series in the thickness direction of each piezoelectric body
Data Source
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AI summary
A sensor module (10) includes a first member (12) including a first recess (30) in which a sensor element (42) including a piezoelectric element and an electrode is arranged, a second member (34) joined to the first member (12), a first plate (70) in contact with the second member (34), a second plate (80) in contact with the first member (12), and a fastening section (86) configured to fasten the first plate (70) and the second plate (80). A first projection (72) projecting toward the second member (34) is provided on the first plate (70). The internal height of the first recess (30) of the first member (12) is larger than the height of the sensor element (42). The sensor element (42) is in contact with the second member (34).