Seat Heater with Non-Return Temperature Switch to Prevent Overheating

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Solution Overview

Problem

Conventional seat heaters in vehicles, especially hybrid and electric vehicles, face challenges in maintaining comfort and safety due to overheating issues when increasing output and heat density, as return-type temperature switches can lead to unsafe temperature fluctuations.

Innovation Solution

A seat heater design incorporating a non-return type temperature switch as the overheating-prevention unit, connected in parallel with the warming heaters and heated by a separate unit, ensures reliable shutdown and improved safety by setting the activation temperature higher than normal conditions, and includes redundant heating units for enhanced reliability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If the output and heat density of the seat heater are increased to improve warmup performance, then the heating efficiency is improved, but the risk of overheating and safety issues increases

Engineering Contradiction:
Improvewarmup performanceVSAvoidoverheating risk
Core Design Contradiction:
ProductivityVSObject-affected harmful factors

Solution Approach 1:

The patent implements a preliminary protective action by installing a heat-resistant member between the heater and the seat cover before overheating can occur. This member is pre-positioned to intercept excessive heat, preventing it from reaching the seat cover and causing damage or safety hazards, thus allowing higher heater output without proportionally increasing overheating risk

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The heat-resistant member acts as an intermediary element between the heat source (heater) and the protected component (seat cover). It mediates the thermal interaction by absorbing or blocking excessive heat, allowing the system to operate at higher outputs while protecting the seat cover from thermal damage

Inventive Principle:
Principle #24Intermediary (Mediator)

2Ease of operation

If a return type temperature switch is used to control heater ON/OFF, then the device can reset automatically when temperature normalizes, but the heaters may turn ON again after overheating, compromising safety

Engineering Contradiction:
Improveautomatic reset functionVSAvoidsafety
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The patent extracts the temperature control function from the safety protection function. By separating these functions and implementing a heat-resistant physical barrier, the system removes the unreliable automatic reset capability that could cause safety issues, while maintaining operational control through manual intervention requirements after overheating events

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent converts the potential harm of automatic reset (safety risk) into a benefit by using the heat-resistant member to physically block heat transmission. The system accepts the loss of automatic reset functionality and uses the heat-resistant barrier to provide continuous passive protection, turning the design constraint into a more reliable safety mechanism

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

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 configuration ensures comfort and safety by preventing overheating, allowing for higher output and heat density without compromising user safety, even in the event of temperature control unit failure, and is applicable to various vehicle types and personal seating.

Implementation Method 1

a heating unit that heats the overheating-prevention unit

Methodology Applied
Scientific EffectJoule heating: Joule Heating

Implementation Method 2

a first warming heater that warms a seat section of a seat; a second warming heater that warms a back section of the seat

Methodology Applied
Scientific EffectJoule heating: Joule Heating

Data Source

PatentEP2703212B1Seat heater
Publication Date: 2017.05.31 PANASONIC INTELLECTUAL PROPERTY MANAGEMENT CO LTD
  • EP2703212B1 patent drawingFigure 1
  • EP2703212B1 patent drawingFigure 2
  • EP2703212B1 patent drawingFigure 3

AI summary

The seat heater of the present invention comprises: a warming heater (1a) provided in a seat section of a seat; a warming heater (1b) provided in a back section; an overheating-prevention unit (2); and a heating unit (3) that heats the overheating-prevention unit (2), the overheating-prevention unit (2) being configured by a non-return type temperature switch. This configuration allows activating the non-return type overheating-prevention unit prior to reaching an unsafe event, and turns the warming heaters (1a, 1b) OFF reliably, whereby a seat heater with an aim of implementing both high output and safety can be provided.