Seat Comfort Valve Circuit With Air Mass Feedback Control

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Solution Overview

Problem

Existing seating comfort systems with air cushions, such as lumbar support and massage devices, face challenges in reliably controlling the filling level and avoiding thermal overload of shape memory alloy (SMA) elements used in valves, which can lead to mechanical stress and potential damage due to dirt, abrasion, and high switching frequencies.

Innovation Solution

A seating comfort system with a circuit arrangement that includes an air mass measuring device and a control unit to measure and regulate the air mass flowing through valves, using SMA elements or other actuators, allowing for contactless detection of filling states and precise control of the valve opening and closing, thereby reducing mechanical stress and improving reliability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If SMA elements are used to actuate valves in seat comfort systems, then precise control of air cushions is achieved, but thermal overload and mechanical damage occur due to high switching frequencies and dirt accumulation

Engineering Contradiction:
Improvecontrol precisionVSAvoidvalve reliability
Core Design Contradiction:
Measurement precisionVSReliability

Solution Approach 1:

The patent replaces mechanical limit switches with a magnetic field-based detection system. Hall effect sensors detect the position of actuating elements through magnetic fields, eliminating mechanical contact points that are susceptible to dirt and wear. This substitution maintains precise control while significantly improving reliability in harsh environments.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent introduces magnetic fields as an intermediary between the actuator and the detection system. Magnetic couplings transmit positional information without physical contact, allowing the system to monitor valve positions and control SMA element activation without exposing sensors to dirt and mechanical stress.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Ease of operation

If limit switches are used to detect valve positions, then switching control is achieved, but mechanical stress and wear increase due to high switching frequencies and dirt

Engineering Contradiction:
Improveswitching controlVSAvoidmechanical stress
Core Design Contradiction:
Ease of operationVSObject-affected harmful factors

Solution Approach 1:

The patent replaces mechanical limit switches with contactless magnetic field sensors. Hall effect sensors and magnetic couplings detect actuator positions without physical contact, eliminating mechanical wear from high-frequency switching while maintaining precise position detection and control capabilities.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent creates a magnetic field copy of the mechanical position information. Instead of direct mechanical contact, the system uses magnetic fields to replicate positional data from the actuator, allowing electronic processing of position signals without subjecting the detection system to mechanical stress.

Inventive Principle:
Principle #26Copying

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 system effectively controls the air mass in air cushions, ensuring reliable operation and reducing mechanical stress on the valves, enhancing the durability and performance of the seating comfort system by using an air mass measuring device and a control unit to manage the air flow and pressure within the system.

Implementation Method 1

The actuator (103) comprises an SMA element (100), which is designed as a V-shaped SMA wire

Methodology Applied
Scientific EffectJoule heating: Joule Heating

Implementation Method 2

The SMA element is typically an SMA wire. The supplied power must typically be kept within a very narrowly defined range to ensure reliable activation of the actuator

Methodology Applied
Scientific EffectShape memory alloy effect: Shape Memory Alloy

Implementation Method 3

a measuring wire (305), in particular one of the SMA wires (100-1 to 100-N), past which the air mass to be measured flows

Methodology Applied
Scientific EffectHeat transfer: Conduction (thermal)

Data Source

PatentEP4060190B1Circuit assembly and method for controlling at least one valve, valve, valve arrangement and seating comfort system
Publication Date: 2024.09.04 GENTHERM PRAEZISION SE
  • EP4060190B1 patent drawingFigure 1A~1B
  • EP4060190B1 patent drawingFigure 1C~2
  • EP4060190B1 patent drawingFigure 3~4

AI summary

The invention relates to a circuit arrangement (1) for controlling at least one valve (120), in particular a valve (120) of a seat comfort system (2), wherein the at least one valve comprises at least one actuator (103) with at least one actuating element (104), wherein the actuating element (104) is adjustable between at least a first position and a second position, and wherein the circuit arrangement (1) has at least one driver unit (6) for actuating the actuator (103) and a control unit (30) for controlling the driver unit (6). The circuit arrangement according to the invention is characterized in that it comprises at least one air mass measuring device (305-1 to 305-N) for measuring an air mass flowing through the valve, wherein the control unit (30) is suitable for processing an output signal from the air mass measuring device (305-1 to 305-N, 305-X, 305a to 305d).Furthermore, the invention relates to a method for controlling a valve by means of the circuit arrangement according to the invention, a valve, a valve arrangement and a seat comfort system.