Fixing Sleeve Spinning for Smoother Inner Surface Finish

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Solution Overview

Problem

The existing methods for manufacturing thin-wall metal tubular bodies for fixing sleeves in laser printers and copiers result in inner circumferential surfaces with high surface roughness due to the transfer of mandrel protrusions and depressions, leading to thermal efficiency degradation and increased production costs.

Innovation Solution

A method involving a mandrel with a smooth outer surface and a spinning process that reduces surface roughness by transferring this smoothness to the inner surface of the tubular body, combined with techniques like burnishing or sandblasting to remove roller marks and achieve a mirror-finished surface.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If a conventional spinning process with a standard mandrel is used to manufacture thin-wall metal tubular bodies, then the manufacturing process can be completed, but the inner circumferential surface develops high surface roughness due to transferred mandrel protrusions and depressions

Engineering Contradiction:
Improvesurface roughness of inner circumferential surfaceVSAvoidmanufacturing process complexity
Core Design Contradiction:
Manufacturing precisionVSEase of manufacture

Solution Approach 1:

The invention changes the surface parameter of the mandrel by applying a coating layer with specific surface properties. The coating layer has a surface roughness Ra of 0.05 μm or less, which is significantly smoother than the conventional mandrel surface. This parameter change in the mandrel's surface roughness directly transfers to the inner circumferential surface of the tubular body, achieving the desired smooth surface without complex post-processing.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The mandrel is constructed as a composite structure with a base material and a coating layer. The coating layer is made of a material with excellent surface smoothness properties, such as polished metal or ceramic coating. This composite structure combines the mechanical strength of the base material with the surface smoothness of the coating, allowing the mandrel to both withstand manufacturing stresses and produce smooth inner surfaces on the tubular bodies.

Inventive Principle:
Principle #40Composite materials

2Use of energy by moving object

If the wall thickness of the metal tubular body is reduced to 20 μm to 50 μm to achieve thin-wall structure, then power consumption is reduced and standby time is shortened, but the inner circumferential surface becomes more sensitive to mandrel surface defects

Engineering Contradiction:
Improvepower consumptionVSAvoidsurface roughness of inner circumferential surface
Core Design Contradiction:
Use of energy by moving objectVSManufacturing precision

Solution Approach 1:

The invention changes the critical parameter of mandrel surface roughness to Ra of 0.05 μm or less through coating application. This extreme surface smoothness compensation is necessary because the ultrathin wall thickness (20-50 μm) amplifies the impact of any mandrel surface defects on the final product quality. The coated mandrel ensures that even with reduced wall thickness, the inner surface maintains the required smoothness for thermal efficiency.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The coating is applied to the mandrel before the spinning process, performing the surface smoothing action in advance. This preliminary action ensures that when the thin-wall tubular body is formed, the smooth surface is already embedded in the mandrel, eliminating the need for post-manufacturing surface treatment and protecting the thin wall structure from damage during subsequent processing.

Inventive Principle:
Principle #10Preliminary action

3Ease of operation

If a film coating method is used to reduce friction resistance on the inner circumferential surface, then friction is reduced, but production cost increases and thermal efficiency degrades due to increased film thickness

Engineering Contradiction:
Improvefriction resistanceVSAvoidthermal efficiency
Core Design Contradiction:
Ease of operationVSLoss of energy

Solution Approach 1:

The invention changes the surface roughness parameter to Ra of 0.05 μm or less through mandrel coating, which naturally reduces friction resistance without requiring additional friction-reducing film coatings on the tubular body. This eliminates the need for fluororesin films that would increase thickness and reduce thermal efficiency. The smooth surface alone provides sufficient friction reduction for the fixing sleeve operation.

Inventive Principle:
Principle #35Parameter changes

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 method significantly reduces surface roughness, enhancing thermal efficiency and durability while maintaining the thin-wall structure, thus improving the performance and cost-effectiveness of the fixing sleeve.

Implementation Method 1

a mandrel with a smooth outer surface and a spinning process that reduces surface roughness by transferring this smoothness to the inner surface of the tubular body

Methodology Applied
Scientific EffectSurface transfer:

Implementation Method 2

the heat of the heating heater be transferred to the fixing nip portion. Therefore, thermal efficiency is strongly affected by the surface roughness of the inner circumferential surface of the fixing sleeve

Methodology Applied
Scientific EffectThermal conduction: Conduction (thermal)

Data Source

PatentEP3059024B1Fixing sleeve and manufacturing method thereof
Publication Date: 2023.07.19 ENDO MFG CO LTD
  • EP3059024B1 patent drawingFigure 1A~1B
  • EP3059024B1 patent drawingFigure 2A~2B
  • EP3059024B1 patent drawingFigure 3A~3B

AI summary

Provided is a fixing sleeve making it possible to reduce the surface roughness of the inner circumferential surface of the fixing sleeve by spinning, and a method for manufacturing the fixing sleeve. The spinning is performed by moving rollers 4, in the axial direction of a cup-shaped tubular body 2 and, at the same time, a burnishing tool (spherical tool) 7 is pressed against the outer circumferential surface 22 of the cup-shaped tubular body 2 after the spinning, and the burnishing tool 7 is moved in the same direction as the rollers 4. The cup-shaped tubular body 2 is plastically deformed in the axial direction of the cup-shaped tubular body 2, reduced in wall thickness, and elongated in the axial direction.