Fixing Belt Multilayer Structure for Heat and Strength
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional fixing devices using electromagnetic induction heating face challenges in achieving both high mechanical strength and heat generation efficiency, particularly due to the limitations of magnetic shunt alloys like Permalloy, which lack mechanical strength and require annealing that degrades the strength of copper layers, leading to issues with heat generation control and mechanical integrity.
Innovation Solution
A fixing device with a multilayer structure including a non-magnetic conductive layer and a first magnetic conductive layer, both thinner than the skin depth of their materials, and a supporting member with a second magnetic conductive layer, where the magnetic conductive layers have higher specific resistance than the non-magnetic layer, manufactured through plastic forming or plating, to enhance mechanical strength and heat generation efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If a magnetic shunt alloy layer (e.g., Permalloy) is used as the heat generation control layer, then heat generation efficiency is improved through magnetic flux concentration, but mechanical strength is degraded and the fixing member becomes prone to damage
Solution Approach 1:
The invention uses a composite structure consisting of a magnetic shunt alloy layer (Permalloy) combined with a ferromagnetic powder layer (Fe-Si-Al-O-B glass powder). This composite structure allows the magnetic shunt alloy to provide heat generation control through magnetic flux concentration while the ferromagnetic powder layer provides mechanical strength and structural integrity, resolving the contradiction between heat generation efficiency and mechanical strength
Solution Approach 2:
The invention changes the magnetic properties of the heat generation control layer by controlling the Curie temperature through compositional adjustment of the ferromagnetic powder (Fe-Si-Al-O-B glass). By setting the Curie temperature close to the fixing temperature, the layer transitions from ferromagnetic to paramagnetic state at operating temperature, enabling automatic heat generation control while maintaining structural stability
2Stability of the object's composition
If annealing is performed on the entire fixing member containing Permalloy to obtain preferable magnetism, then magnetic properties are improved, but the mechanical strength of copper and Permalloy layers is degraded
Solution Approach 1:
The invention segments the heat generation control layer into two distinct functional layers: a magnetic shunt alloy layer (Permalloy) for magnetic flux concentration and a ferromagnetic powder layer (Fe-Si-Al-O-B glass powder) for providing mechanical strength and structural support. This segmentation allows each layer to perform its specific function without compromising the other, avoiding the need for annealing that would degrade mechanical strength
3Strength
If a reinforcing layer is formed by electrolytic plating on the surface closer to the excitation coil to secure mechanical strength, then mechanical strength is improved, but heat generation efficiency is degraded
Solution Approach 1:
The invention resolves the spatial conflict between mechanical strength and heat generation efficiency by transitioning from a single-layer structure to a multilayer structure with different functions arranged in the thickness dimension. The magnetic shunt alloy layer is positioned closer to the excitation coil for magnetic flux concentration and heat generation, while the ferromagnetic powder layer is positioned farther away to provide mechanical strength without interfering with the electromagnetic induction process
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 achieves high heat generation efficiency while maintaining mechanical strength, self-adjusting heat generation to prevent overheating and ensuring stable fixing performance, even with small sheets, by controlling magnetic flux and eddy current distribution effectively.
Implementation Method 1
a non-magnetic conductive layer and a first magnetic conductive layer, both thinner than the skin depth of their respective materials
Implementation Method 2
a part of fixing member with a small thermal capacity, such as a belt, is caused to generate Joule heat by electromagnetic induction
Implementation Method 3
the first magnetic conductive layer... being located farther from an outside surface of the endless fixing belt than the non-magnetic conductive layer
Implementation Method 4
The heat generation control layer attracts the magnetic flux generated by the excitation coil and concentrates the induced current (i.e. eddy current) to the primary heat generator layer
Implementation Method 5
a supporting member disposed inside the endless fixing belt and including a second magnetic conductive layer having a thickness larger than a skin depth of a material thereof
Implementation Method 6
At or below the Curie temperature, the heat generation control layer serves as a ferromagnetic. Above the Curie temperature, the heat generation control layer serves as a paramagnetic
Data Source
AI summary
A fixing device comprising: an endless fixing belt having a multilayer structure including a non-magnetic conductive layer and a first magnetic conductive layer, the non-magnetic conductive layer having a thickness smaller than a skin depth of a material thereof, the first magnetic conductive layer having a thickness smaller than a skin depth of a material thereof and being located farther from an outside surface of the fixing belt than the non-magnetic conductive layer; and a supporting member disposed inside the endless fixing belt and including a second magnetic conductive layer having a thickness larger than a skin depth of a material thereof. The first magnetic conductive layer and the second magnetic conductive layer have a higher specific resistance than the non-magnetic conductive layer, and the first magnetic conductive layer has been manufactured by plastic forming or plating.