Fixing Apparatus Heater Thermal Expansion Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The existing fixing apparatuses in image forming devices face challenges in preventing foreign substances from entering the gap between the heater and the trench portion while maintaining effective temperature control to prevent excessive temperature rise in the sheet non-passing portion, as the heat conducting member warps due to friction and thermal expansion, reducing the effectiveness of temperature regulation.
Innovation Solution
A fixing apparatus with a heat conducting member, such as an aluminum plate, that includes a notch to offset the contact area with the protrusion, allowing for thermal expansion without deformation, and a configuration of protrusions to maintain the gap's integrity and prevent foreign substances from entering, ensuring both effective temperature control and foreign substance prevention.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If the heat conducting member is brought into contact with the protrusion for preventing warpage, then the heater position is stabilized, but the heat conducting member deforms due to thermal expansion and friction, reducing temperature regulation effectiveness
Solution Approach 1:
The heat conducting member is divided into multiple sections along the conveyance direction, with each section having different contact configurations with the protrusion. The first heat conducting member contacts the protrusion directly, while the second heat conducting member has an offset contact area, creating segmented thermal management zones that prevent uniform deformation while maintaining position stability.
Solution Approach 2:
Different portions of the heat conducting member are given different contact characteristics with the protrusion. The offset contact area in the second heat conducting member creates a local quality difference that allows selective thermal expansion in specific regions, preventing overall deformation while maintaining heater positioning.
2Object-affected harmful factors
If the gap between the trench portion and heater is made small to prevent foreign substance entry, then foreign substance prevention is improved, but the heat conducting member cannot accommodate thermal expansion, causing deformation
Solution Approach 1:
The heat conducting member is designed with dynamic contact characteristics that adapt to thermal expansion. The offset contact area allows the heat conducting member to dynamically adjust its position and contact pressure with the protrusion during thermal cycles, maintaining gap closure for foreign substance prevention while accommodating dimensional changes.
Solution Approach 2:
The contact parameters between the heat conducting member and protrusion are changed by introducing an offset. This parameter change allows the system to transition from a rigid fixed-gap design to a flexible design that maintains gap closure while permitting thermal expansion through modified contact mechanics.
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 solution effectively prevents foreign substances from entering the gap and maintains the temperature regulation effectiveness, ensuring stable operation and accurate temperature detection, while allowing for thermal expansion without deformation of the heat conducting member.
Implementation Method 1
a heat conducting member that is in contact with a surface of the heater disposed opposite to a surface contacting the film
Implementation Method 2
When the heat conducting member in this state thermally expands, the heat conducting member may deform to lift from the heater
Implementation Method 3
When frictional force produced by the rotation of the film is applied to the heat conducting member through the heater, the heat conducting member warps in the conveyance direction of the recording medium
Data Source
AI summary
A fixing apparatus includes a film, a heater contacting an inner surface of the film, a heat conducting member contacting a back surface of the heater, and a supporter supporting the heater, the supporter including a groove accommodating the heater and the heat conducting member. A surface of the groove facing an end surface of the heater on a downstream side includes a first protrusion, a second protrusion, and a third protrusion with gaps between each other in a direction orthogonal to the conveyance direction, the third protrusion being disposed between the first protrusion and the second protrusion and having a smaller protruding amount than the first protrusion and the second protrusion. a portion of the heat conducting member facing the third protrusion is recessed more than portions of the heat conducting member facing the first protrusion and the second protrusion.