Heated Windshield Bus Bar Layout to Prevent Abnormal Heating
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In windshields with multiple heating wires between bus bars, abnormal heat generation occurs in the bus bars when the current increases to enhance heat generation, leading to inefficiencies and potential damage.
Innovation Solution
A windshield design featuring a plate-shaped glass member with a heating region and a heat generator comprising multiple heaters arrayed in a specific direction, with bus bars connected to both ends of each heater in a direction orthogonal to the heaters, and where the bus bars are formed in a band shape with a resistance value significantly lower than the heaters to inhibit abnormal heat generation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If the current flowing through the bus bars is increased to enhance heat generation, then the heating effectiveness is improved, but abnormal heat generation occurs in the bus bars
Solution Approach 1:
The invention changes the resistance parameter of the bus bars by forming them with a thickness of 10 µm or more, which reduces their resistance to 2% or less of the heating wire resistance. This parameter change allows the bus bars to conduct current without generating abnormal heat, while still enabling effective heating of the windshield through the heating wires.
Solution Approach 2:
The invention applies different quality requirements to different components: the heating wires are designed with higher resistance to generate heat, while the bus bars are designed with lower resistance (through increased thickness) to conduct current efficiently without generating abnormal heat. This local differentiation of properties resolves the contradiction between effective heating and preventing bus bar overheating.
2Area of stationary object
If multiple heating wires are disposed between bus bars, then the heating coverage is improved, but the bus bars experience abnormal heat generation when current increases
Solution Approach 1:
The invention changes the geometric parameter of the bus bars (thickness to 10 µm or more) to reduce their resistance. This allows multiple heating wires to be connected in parallel across the bus bars without causing abnormal heat generation, as the reduced bus bar resistance minimizes power loss and heat generation in the bus bars themselves while maintaining effective heating coverage.
3Object-affected harmful factors
If the bus bar thickness is increased to reduce resistance, then abnormal heat generation is inhibited, but the device complexity increases
Solution Approach 1:
The invention resolves the contradiction by changing a single parameter (bus bar thickness to 10 µm or more) rather than complicating the overall structure. This simple parameter change reduces bus bar resistance and prevents abnormal heat generation without significantly increasing device complexity, as it only involves adjusting the thickness of existing components rather than adding new structures.
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 design effectively inhibits abnormal heat generation in the bus bars, ensuring efficient heating of the windshield while preventing potential damage from excessive heat, thus maintaining optimal performance and safety.
Implementation Method 1
a bus bar and a heating wire are disposed in a windshield, and clouding is removed by heat generated by the bus bar and the heating wire
Data Source
AI summary
A windshield according to the present invention comprises: a sheet glass member having a heating region that includes at least a JIS R 3212-tested region A; and a heat-generating means that is disposed in the heating region. The heat-generating means comprises a plurality of heaters formed in a planar shape and arranged in a line in a first direction in the heating region, and a pair of busbars that are connected respectively to the ends in a second direction orthogonal to the first direction in each beater.