Carding Bar Hollow Back Part Design for Vibration Control

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Solution Overview

Problem

Existing flat bars used in carding processes with drum widths over 1,200 mm lack sufficient moment of resistance, leading to vibrations that can cause machine damage, and struggle with heat dissipation and weight optimization.

Innovation Solution

The flat bar design features a supporting body with a foot area and a head area separated by two back parts forming a hollow space, where the lower back parts are thickened and widen towards the head area, increasing the section modulus and heat dissipation, while the upper back parts narrow, allowing for deflection without collision, and maintaining a constant wall thickness for stiffness.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Area of stationary object

If the drum width is increased to more than 1,200 mm, then the carding machine can process larger materials, but the flat bar lacks sufficient moment of resistance and begins to vibrate

Engineering Contradiction:
Improvedrum widthVSAvoidmoment of resistance
Core Design Contradiction:
Area of stationary objectVSStrength

Solution Approach 1:

The flat bar cross-section is transformed from a solid shape to a hollow structure with optimized cavity geometry. The cavity is positioned to maximize the section modulus in the tangential direction while maintaining structural integrity. This dimensional reconfiguration allows the flat bar to achieve higher moment of resistance without increasing overall size, resolving the contradiction between large drum width and sufficient strength.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

Solution Approach 2:

The flat bar features non-uniform wall thickness distribution, with thicker sections at critical locations where high moment of resistance is needed. The cavity placement is optimized locally to maximize structural efficiency. This local quality variation allows the flat bar to achieve sufficient strength for large drum widths while maintaining lightness and avoiding unnecessary material in less critical areas.

Inventive Principle:
Principle #3Local quality

2Weight of moving object

If the flat bar is made lighter, then the carding machine is more efficient, but the section modulus decreases and vibration increases

Engineering Contradiction:
Improveflat bar weightVSAvoidsection modulus
Core Design Contradiction:
Weight of moving objectVSStrength

Solution Approach 1:

The flat bar employs a hollow cross-sectional structure that redistributes material from the center toward the outer perimeter. This dimensional change maximizes the section modulus relative to the material used, achieving higher strength-to-weight ratio. The cavity placement is optimized to maintain structural integrity while minimizing weight, directly resolving the contradiction between lightness and section modulus.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

Solution Approach 2:

The flat bar utilizes aluminum alloy materials with optimized composition to achieve high strength-to-weight ratio. The material selection and distribution within the hollow structure are optimized to provide sufficient section modulus while maintaining minimal weight. This approach allows the flat bar to be as light as possible while achieving the required moment of resistance for large drum widths.

Inventive Principle:
Principle #40Composite materials

3Strength

If the flat bar has sufficient section modulus for large drum widths, then vibration is reduced, but heat dissipation becomes insufficient

Engineering Contradiction:
Improvesection modulusVSAvoidheat dissipation
Core Design Contradiction:
StrengthVSTemperature

Solution Approach 1:

The flat bar features strategically positioned cavities and varying wall thicknesses that optimize both structural strength and thermal performance. The cavity placement is designed to maintain adequate section modulus while creating thermal pathways for heat dissipation. Thicker wall sections are positioned in areas requiring both strength and heat dissipation, while thinner sections provide weight reduction. This local quality optimization resolves the contradiction between sufficient section modulus and effective heat dissipation.

Inventive Principle:
Principle #3Local quality

4Strength

If the back part is thickened to increase section modulus, then vibration resistance improves, but the flat bar becomes more complex to manufacture

Engineering Contradiction:
Improvesection modulusVSAvoidmanufacturing complexity
Core Design Contradiction:
StrengthVSEase of manufacture

Solution Approach 1:

The flat bar employs a hollow cross-sectional structure with optimized cavity geometry that achieves high section modulus through intelligent three-dimensional material distribution rather than simple wall thickening. The cavity is positioned and shaped to maximize structural efficiency while remaining compatible with standard extrusion manufacturing processes. This dimensional optimization resolves the contradiction between high section modulus and manufacturing simplicity.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

Solution Approach 2:

The flat bar design optimizes the wall thickness parameter as a function of position along the bar length and around the cross-section. The thickness varies systematically to achieve the required section modulus at critical locations while maintaining manufacturability. The cavity dimensions and wall thicknesses are parameterized to balance structural requirements with manufacturing capabilities, resolving the contradiction between strength and ease of manufacture.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP3953506B1Carding bar for a carding machine
Publication Date: 2023.08.23 TRUETZSCHLER GRP SE
  • EP3953506B1 patent drawingFigure 1
  • EP3953506B1 patent drawingFigure 2
  • EP3953506B1 patent drawingFigure 3

AI summary

The present invention relates to a carding bar (20) having a supporting body (22), to the foot region (23) of which a clothing is fastenable, wherein a head region (25) is arranged in a manner spaced apart from the foot region (23) by at least one back part (21). The invention is characterized in that the back part (21) comprises at least a lower back part (21b), a thickened portion (21c) and an upper back part (21a), wherein the lower back part (21b) has a taper in the region of an undercut (22c), said taper widening in the direction of the head region (25).