Acoustic Sensor Membrane Mounting for Design Flexibility

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Solution Overview

Problem

Conventional ultrasonic sensors have limited design flexibility for their housing and membrane structure, which complicates protection of the electro-acoustic transducer from environmental influences and requires multiple components.

Innovation Solution

A design where a membrane element with a holding region surrounds a portion of the carrier element, forming a positive connection and allowing for resilient or threaded attachment, combined with a cavity for acoustic signal reflection and a separate housing for electronics, reduces component count and enhances protection.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the diaphragm is made accessible from inside the housing for piezoceramic attachment, then the piezoelectric transducer can be protected from environmental influences, but the design flexibility of the housing and diaphragm is limited

Engineering Contradiction:
Improveprotection of piezoelectric transducerVSAvoiddesign flexibility
Core Design Contradiction:
ReliabilityVSAdaptability or versatility

Solution Approach 1:

Instead of making the diaphragm accessible from inside the housing as in conventional designs, the patent inverts the approach by providing a mounting area that extends toward the carrier element and encompasses a partial region of the carrier element. This allows the diaphragm to be mounted from the outside while still protecting the piezoelectric transducer inside the housing, thereby resolving the contradiction between protection and design flexibility.

Inventive Principle:
Principle #13The other way round (Inversion)

2Reliability

If multiple separate components are used for housing and diaphragm protection, then the piezoelectric transducer is protected from environmental influences, but the number of components increases

Engineering Contradiction:
Improveprotection of piezoelectric transducerVSAvoidnumber of components
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent merges the housing and diaphragm into a single integrated component structure. The housing includes an integrated mounting area for the diaphragm that extends toward the carrier element and encompasses a partial region of the carrier element. This integration eliminates the need for separate protection components while maintaining effective protection of the piezoelectric transducer, thus reducing device complexity.

Inventive Principle:
Principle #5Merging (Combining)

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 offers increased design freedom, improved protection against environmental influences, and a simpler assembly process while maintaining high tightness and manufacturing tolerance, allowing for a compact and efficient acoustic sensor.

Implementation Method 1

the membrane element has a mounting area at at least one edge region which extends in the direction of the carrier element and encompasses a partial region of the carrier element... there is a positive fit between the mounting area of the membrane element and the support element

Methodology Applied
Scientific EffectPositive fit: Mechanical Fastener

Implementation Method 2

an electroacoustic transducer which is arranged on a side of the membrane element facing the carrier element and is configured to excite at least a region of the membrane element to vibrate

Methodology Applied
Scientific EffectElectroacoustic transduction: Piezoelectric Effect

Implementation Method 3

excite at least a region of the membrane element to vibrate

Methodology Applied
Scientific EffectMechanical vibration: Vibration

Implementation Method 4

The cavity forms, in particular, a reflection area through which acoustic signals emanating from the membrane element are reflected and directed back towards the primary transmission direction of the acoustic sensor

Methodology Applied
Scientific EffectAcoustic reflection: Reflection

Data Source

PatentEP3341931B1Acoustic sensor with a housing and a membrane element arranged on said housing
Publication Date: 2024.03.13 ROBERT BOSCH GMBH
  • EP3341931B1 patent drawingFigure 1~2
  • EP3341931B1 patent drawingFigure 3a~3c

AI summary

The present invention relates to an acoustic sensor (1) comprising a carrier element (2), a membrane element (3), which is arranged on a first side of the carrier element (2), and an electroacoustic transducer (4), which is arranged on a side (4a) of the membrane element (3), said side being directed towards the carrier element (2), and is intended to cause at least one region of the membrane element (3) to oscillate, wherein, on at least one peripheral region (5), the membrane element (3) has a retaining region (6), which extends in the direction of the carrier element (2) and engages around a sub-region (7) of the carrier element (2).