Vehicle Ultrasonic Sensor Ribbed Decoupling for Echo Detection
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Solution Overview
Problem
Ultrasonic sensors for motor vehicles face challenges in structural dynamics, particularly in energy transmission and echo signal detection due to the use of plastic housings and metallic contact elements, leading to inefficiencies in measuring distances using the pulse echo process.
Innovation Solution
The implementation of a decoupling element, such as a silicone ring, with ribs formed on the interior surface of the plastic housing, which is softer than the membrane module, reducing the contact area and enhancing acoustic decoupling by dissipating vibration energy through internal friction, thereby improving structural dynamics and reducing energy transmission to the housing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a decoupling element is used to reduce energy transmission to the housing, then structural dynamics are improved, but the contact area between the decoupling element and housing must be optimized to avoid excessive rigidity
Solution Approach 1:
The decoupling element is nested within the housing structure, with ribs extending into the housing interior. This nested configuration allows the decoupling element to be integrated into the existing housing design while maintaining acoustic decoupling functionality, thereby improving structural dynamics without significantly increasing device complexity.
Solution Approach 2:
The decoupling element features ribs with specific geometric configurations (height, spacing, cross-sectional shape) that create localized variations in rigidity. These local quality modifications allow the decoupling element to have different mechanical properties in different regions, optimizing energy transmission characteristics while maintaining overall structural integrity.
2Ease of manufacture
If the decoupling element fully contacts the housing inner surface, then assembly is simplified, but energy transmission to the housing increases
Solution Approach 1:
The contact surface of the decoupling element is segmented into multiple discrete ribs rather than a continuous surface. This segmentation creates gaps between the ribs that allow vibration energy to be isolated and dissipated, reducing energy transmission to the housing while still providing sufficient mechanical support and assembly stability.
Solution Approach 2:
The decoupling element has a porous-like structure with gaps between the ribs, which allows it to dissipate vibration energy through internal friction while maintaining structural integrity. This porous configuration reduces the effective contact area with the housing, thereby reducing energy transmission while still providing adequate support.
3Loss of energy
If ribs are added to the decoupling element to reduce contact area, then energy transmission is reduced, but manufacturing complexity increases
Solution Approach 1:
The ribs are designed with specific geometric parameters (height, spacing, cross-sectional dimensions) that can be optimized based on the desired energy transmission characteristics. By carefully selecting these parameters, the decoupling element achieves effective vibration isolation while maintaining manufacturability through standard fabrication processes.
Solution Approach 2:
The decoupling element may be constructed from composite materials or multi-layer structures that provide both the necessary mechanical properties and vibration damping characteristics. This allows the ribs to be formed with complex geometries while maintaining ease of manufacture through material properties that facilitate forming and assembly.
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 enhances the ultrasonic sensor's ability to detect echo signals more effectively by reducing energy transmission and improving assembly simplicity, leading to improved structural dynamics and enhanced performance in measuring distances within the vehicle environment.
Implementation Method 1
enhancing acoustic decoupling by dissipating vibration energy through internal friction
Implementation Method 2
The ultrasonic membrane, excited by a sound transducer element attached to it, emits energy in the form of an ultrasonic signal
Implementation Method 3
measure a distance to an object in the vehicle's surroundings or to an object in the vehicle's interior using the pulse-echo method
Implementation Method 4
The sound transducer element then detects vibrations of the ultrasonic membrane resulting from an echo signal returning from the vehicle's surroundings or the interior
Data Source
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AI summary
The invention relates to an ultrasonic sensor (1) having an improved structural dynamic for a motor vehicle (20). The ultrasonic sensor (1) comprises: a plastic housing (2), a membrane assembly (3) arranged in a housing opening (4) of the plastic housing (2), the membrane assembly having an ultrasonic membrane (8), and a decoupling element (6) which is arranged between an inner surface (5) of the plastic housing (2) and the membrane assembly (3). A plurality of ribs (7, 71, 72) are formed at the inner surface (5) of the plastic housing (2), on which the decoupling element (6) rests against, and the ribs (7, 71, 72) are designed in such a way that the decoupling element (6) does not rest against the entire inner surface (5) of the plastic housing (2).