Motor Vehicle Sensor Sealing Ring with Drainage Recesses
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Solution Overview
Problem
Existing sensor arrangements in motor vehicles, particularly ultrasonic sensors, face issues with acoustic coupling and water ingress due to tolerances between the sensor and component, leading to incorrect obstacle detection and reduced effectiveness, especially in car washes where water can freeze and create acoustic bridges.
Innovation Solution
A sealing ring with an additional outer ring element featuring recesses and webs or lamellae to ensure mechanical and acoustic decoupling, allowing water to drain off and compensating for axial tolerances, while maintaining a seal and correct sensor positioning.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a sealing ring with conical axial cross section is used, then the sensor can be sealed from the component, but tolerances between the diameter of the recess and the sealing ring allow water to penetrate between them
Solution Approach 1:
The sealing ring is made of elastomeric material that can deform elastically to compensate for dimensional tolerances. This flexible membrane adapts to the recess geometry, ensuring reliable sealing despite manufacturing variations in the recess diameter.
Solution Approach 2:
The sealing ring incorporates an axial bead that can deform under pressurized water conditions. This parameter change in the sealing ring's physical state allows it to maintain contact and sealing effectiveness even when dimensional tolerances exist between the recess and sealing ring.
2Reliability
If a decoupling ring with circumferential bead is used, then acoustic decoupling is achieved, but water entering under pressure cannot drain off quickly and can freeze, creating an acoustic bridge
Solution Approach 1:
The decoupling ring is segmented into multiple radial sections that can move independently. This segmentation creates channels for water drainage while maintaining the acoustic decoupling function, preventing water accumulation that could freeze and create acoustic bridges.
Solution Approach 2:
The decoupling ring incorporates axial drainage channels that provide a third dimension for water escape. This dimensional addition allows water to drain off quickly from the pressurized side, preventing freezing issues while maintaining radial acoustic decoupling.
3Reliability
If the sealing ring is pressed by pressurized water, then water penetrates between the component and the sealing ring, but remaining water can freeze and couple sound into the installation environment
Solution Approach 1:
The harmful water that penetrates the seal is extracted and directed through drainage channels in the decoupling ring. This removes the water from positions where it could freeze and create acoustic bridges, while the seal itself maintains its integrity against pressurized water.
Solution Approach 2:
The decoupling ring acts as an intermediary between the sealing ring and the external environment. It provides a controlled path for water that penetrates the seal, preventing direct contact between water and the component structure where freezing would create acoustic coupling.
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
The solution provides stable acoustic decoupling and effective water drainage, preventing freezing issues and ensuring accurate obstacle detection by maintaining the sensor's functionality even under pressurized conditions.
Implementation Method 1
The ring element lying on the outside consists of a plurality of sections arranged in the shape of a ring... water penetrating can run off via the recesses
Implementation Method 2
The sensor arranged on the component is in particular an ultrasonic sensor and is acoustically decoupled from the component or the structure in which they are installed by a decoupling part, so that vibrations that occur are not transmitted from the sensor to the component and from the component to the sensor
Implementation Method 3
Ultrasonic sensors emit ultrasonic signals, which are reflected by an object or obstacle in the transmission range and are received by the same or by other ultrasonic transducers
Implementation Method 4
For this reason, it is important that the membrane on the face of the sensor can vibrate freely
Implementation Method 5
If the sealing ring with circumferential bead is subjected to pressurized water, the water that hits it can penetrate between the component and the sealing ring. Remaining water can freeze quickly and lead to the emitted sound being coupled into the installation environment
Data Source
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AI summary
The invention relates to an arrangement on a component of a motor vehicle, consisting of a sensor with a substantially planar end surface, a sealing ring which encloses the sensor, and a carrier element for maintaining the spacing of the sensor in the axial direction relative to the component, wherein the sensor extends with the sealing ring into a cut-out of the component. The sensor has a surrounding sealing ring, an additional ring element which lies further to the outside in the radial direction and has at least two cut-outs which are distributed over the circumference. The elastic ring element of the sealing ring or decoupling ring serves for sealing against water which enters from outside and for correct self-positioning in the cut-out of the component. The cut-outs according to the invention in the ring element which lies on the outside allow water which has entered to drain.