Ultrasonic Sensor Piezoelectric Assembly Pressing Mechanism
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Solution Overview
Problem
Conventional ultrasonic sensing devices for diesel engine urea concentration detection face reliability issues due to inadequate adhesive force of encapsulants and difficulties in controlling the amount and quality of encapsulants and piezoelectric sheets, leading to material waste and inefficiencies in manufacturing.
Innovation Solution
The ultrasonic sensing device incorporates a housing with a piezoelectric assembly, a board, and fixing members to securely attach the piezoelectric sheet to the housing, using a board to press the encapsulating body and ensure tight attachment, and integrates the encapsulating body and piezoelectric sheet as a module for advanced quality control and rework capabilities.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If an encapsulant is injected into the housing to attach the piezoelectric sheet to the sensing surface, then the piezoelectric sheet can be secured in place, but the adhesive force may be insufficient leading to reliability issues
Solution Approach 1:
The piezoelectric assembly is segmented into a piezoelectric sheet and an encapsulating body, where the encapsulating body is integrally formed with the piezoelectric sheet and then assembled to the housing. This segmentation allows the encapsulating body to provide structural support and enhance attachment reliability without relying solely on encapsulant adhesive force.
Solution Approach 2:
The encapsulating body is integrally formed with the piezoelectric sheet in advance before assembly to the housing. This preliminary action ensures strong bonding between the encapsulating body and piezoelectric sheet, and the encapsulating body is designed with features that facilitate reliable attachment to the housing, improving overall attachment reliability before the device is put into use.
2Ease of manufacture
If an encapsulant is injected into the housing to attach the piezoelectric sheet, then the piezoelectric sheet can be secured, but it is difficult to precisely control the amount of encapsulant causing material waste
Solution Approach 1:
The piezoelectric assembly is segmented into a piezoelectric sheet and an encapsulating body, eliminating the need to inject encapsulant into the housing. The encapsulating body is a separate component that is assembled to the housing, allowing precise control of material usage and reducing waste.
Solution Approach 2:
The encapsulating body is integrally formed with the piezoelectric sheet in advance in a controlled manufacturing process. This preliminary formation allows precise control of the encapsulating body's dimensions and material quantity, reducing material waste compared to injecting encapsulant into the housing during assembly.
3Ease of manufacture
If an encapsulant is injected into the housing to attach the piezoelectric sheet, then the piezoelectric sheet can be secured, but it is difficult to control the quality of the piezoelectric sheet and encapsulant or perform rework
Solution Approach 1:
The piezoelectric assembly is segmented into a piezoelectric sheet and an encapsulating body, which are integrally formed together. This segmentation allows the encapsulating body to serve as a protective housing for the piezoelectric sheet, enabling easy access for quality inspection and rework without damaging the piezoelectric sheet.
Solution Approach 2:
The encapsulating body is integrally formed with the piezoelectric sheet in advance, providing a protective structure that facilitates quality control during manufacturing. The encapsulating body can be opened or removed for rework, allowing easy access to the piezoelectric sheet for inspection, repair, or replacement without damaging surrounding components.
4Reliability
If a board is used to press the encapsulating body to ensure tight attachment of the piezoelectric sheet, then attachment reliability is improved, but device complexity increases
Solution Approach 1:
The board is designed to perform multiple functions: it presses the encapsulating body to ensure tight attachment of the piezoelectric sheet, provides structural support for the device, and can serve as a mounting surface for other components. This multi-functionality reduces the need for additional components, thereby limiting the increase in device complexity.
Solution Approach 2:
The board is designed as a thin, flexible component that can conform to the housing structure and apply uniform pressure to the encapsulating body. This thin-film design minimizes the added complexity and volume compared to rigid pressing mechanisms, while still ensuring reliable attachment of the piezoelectric sheet.
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 the reliability of the ultrasonic sensing device by ensuring a secure attachment of the piezoelectric sheet and allows for precise material control, reducing waste and improving manufacturing efficiency.
Implementation Method 1
The piezoelectric assembly includes an encapsulating body and a piezoelectric sheet
Data Source
AI summary
An ultrasonic sensing device includes a housing, a piezoelectric assembly, a board and a plurality of fixing members. The housing includes a bottom wall, a top wall and a surrounding side wall connected between the top wall and the bottom wall. The piezoelectric assembly includes an encapsulating body and a piezoelectric sheet, wherein at least a portion of the piezoelectric sheet is enclosed by the encapsulating body and has a sensing surface exposed to the encapsulating body and facing the bottom wall. The board is disposed on the top wall of the housing and has a pressing surface facing the encapsulating body and the top wall. The plurality of fixing members is configured to fix the board to the top wall of the housing to press the board to the encapsulating body of the piezoelectric assembly, thereby pressing the sensing surface of the piezoelectric sheet to the bottom wall.