Air-Mass Sensing Valve for Reliable Seat Cushion Fill Control
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Solution Overview
Problem
Existing seat comfort systems, such as those with air cushions in vehicle seats, face issues with mechanical switches in valves being impaired by dirt, abrasion, liquids, and high switching frequencies, leading to unreliable operation.
Innovation Solution
Incorporation of an air mass measuring device within the valve, utilizing a measuring wire to detect air mass flow, combined with a control unit and actuator, allows for contactless detection of fill states and precise control of valve operation, using SMA elements or alternative actuators like piezoelectric or magnetic elements.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If mechanical switches are used in valves for detecting fill states, then the valve structure can be simple and cost-effective, but the reliability deteriorates due to impairment from dirt, abrasion, liquids, and high switching frequencies
Solution Approach 1:
The patent replaces mechanical switches with a capacitive sensor system that uses electrical fields to detect the fill state of air cushions. The capacitive sensor measures changes in capacitance caused by the dielectric properties of air versus conductive foam material, eliminating mechanical contact and associated reliability issues while maintaining simple valve structure.
Solution Approach 2:
The patent introduces a capacitive sensor as an intermediary detection mechanism between the fill state condition and the valve control system. This intermediary uses electrical field interaction with the foam material to detect fill levels without mechanical contact, providing reliable operation while keeping the overall valve structure simple.
2Reliability
If contactless detection using air mass measuring device is implemented, then reliability improves by reducing mechanical stress, but device complexity increases due to additional sensors and control circuitry
Solution Approach 1:
The patent makes the foam material serve multiple functions: it acts as both the structural comfort element in the air cushion and as the dielectric medium for capacitive sensing. This multi-functionality allows contactless detection without adding separate complex sensing mechanisms, as the existing foam material enables the sensing function.
Solution Approach 2:
The patent merges the structural foam material with the sensing function by utilizing the foam's dielectric properties for capacitive detection. This combination eliminates the need for separate mechanical switches or complex sensor assemblies, achieving contactless detection while minimizing additional device complexity.
3Ease of operation
If SMA elements are used for actuation, then precise control of valve opening/closing is achieved, but thermal overload risk increases which can permanently damage the actuator
Solution Approach 1:
The patent implements a feedback control system where the capacitive sensor continuously monitors the fill state and provides real-time information to the control unit. The control unit uses this feedback to precisely control the SMA element actuation, applying power only when needed and stopping before thermal overload occurs, thus achieving precise valve control while preventing actuator damage.
Solution Approach 2:
The patent uses periodic or pulsed actuation of the SMA element based on capacitive detection thresholds. Instead of continuous power application, the system applies thermal energy in controlled pulses to achieve the desired valve state, then allows cooling periods, preventing thermal accumulation and overload while maintaining precise control.
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
Enables accurate determination of air volume in air cushions, reducing mechanical stress on valves and improving reliability by contactless detection and control of fill states, enhancing the functionality and durability of seat comfort systems.
Implementation Method 1
The air mass measuring device comprises at least one measuring wire, wherein the measuring wire is arranged within the valve housing and/or in the valve chamber and/or in the first opening and/or in the second opening
Implementation Method 2
a resistance measuring device for measuring the resistance of the measuring wire
Implementation Method 3
The actuator 103 comprises an SMA element 100, which is designed as a V-shaped SMA wire
Implementation Method 4
The supplied power must usually be kept within a very narrowly defined range to ensure reliable actuator activation while preventing thermal overload
Data Source
Figure 1A~1B
Figure 1C~2
Figure 3~4
AI summary
The invention relates to a valve (120) with a valve housing (102), wherein the valve housing (102) has at least a first opening (105) and at least a second opening (106), wherein the valve housing (102) encloses a valve chamber (109), and wherein the valve (120) comprises an actuator (103) with an actuating element (104), the actuating element (104) being arranged for opening or closing the valve (120). The valve (120) according to the invention is characterized in that the valve (120) comprises at least one air mass measuring device for measuring an air mass flowing through the valve (120) or at least one measuring wire (100) of an air mass measuring device for measuring an air mass flowing through the valve (120). Furthermore, the invention relates to a valve arrangement and a seat comfort system.