Rail Web Ball Rolling with Multi-Stand Grooved and Helical Rolls

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Solution Overview

Problem

Current methods for rolling ball forgings require high-accuracy blanks in the form of bars, limiting the efficiency and flexibility in using scrap railway rails, particularly due to the need for different roll sets and manual handling, which reduces the ability to perform skew rolling with minimal cuts.

Innovation Solution

A method involving heating a railway rail web blank to hot forming temperature, then guiding it through a series of grooved and helical rolls with synchronized rotation speeds to flow form it into a ball shape, minimizing the number of longitudinal stands and reducing geometric accuracy requirements.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If skew rolling is used to produce balls from bar blanks, then production efficiency is improved, but the requirement for high geometric accuracy of blanks increases

Engineering Contradiction:
Improveproduction efficiencyVSAvoidgeometric accuracy of blanks
Core Design Contradiction:
ProductivityVSManufacturing precision

Solution Approach 1:

The invention changes the geometric parameters of the rolling grooves from traditional single-groove configurations to multi-groove configurations with specific depth ratios (first groove depth 0.6-0.8 of blank diameter, second groove depth 0.2-0.4 of blank diameter). This parameter change allows the process to accommodate blanks with lower geometric accuracy while maintaining high production efficiency through continuous rolling operation.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The rolling process is segmented into two distinct stages with different groove configurations: first grooves for initial shaping and material flow control, second grooves for final ball formation. This segmentation allows each stage to optimize for its specific function, reducing the overall geometric accuracy requirements for the blank while maintaining productivity.

Inventive Principle:
Principle #1Segmentation

2Manufacturing precision

If different sets of rolls are used for different ball diameters, then manufacturing precision is improved, but device complexity increases

Engineering Contradiction:
Improveball diameter accuracyVSAvoidnumber of roll sets
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The rolling mill is designed with universal grooved rolls that can produce balls of different diameters by adjusting rolling parameters (speed, feed rate, groove selection) rather than requiring different physical roll sets. The multi-groove configuration on each roll allows selection of different groove depths and patterns to accommodate various ball size requirements, making the equipment multi-functional.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The invention introduces dynamic adjustability in the rolling process through variable rolling speeds, adjustable feed rates, and selectable groove configurations. This dynamic control allows the same roll set to adapt to different production requirements and ball diameters, replacing the static approach of having multiple fixed roll sets for different sizes.

Inventive Principle:
Principle #15Dynamics

3Ease of operation

If manual feeding of billets is used in skew rolling, then ease of operation is maintained, but productivity decreases

Engineering Contradiction:
Improvemanual handling simplicityVSAvoidballs per minute
Core Design Contradiction:
Ease of operationVSProductivity

Solution Approach 1:

The system is designed to accept continuous feeding of bar blanks with reduced geometric accuracy requirements, allowing the rolling process itself to accommodate variations in blank quality. The multi-groove rolls and guides work together to automatically compensate for irregularities, enabling semi-automated or automated feeding without requiring perfectly precise blanks, thus increasing productivity while maintaining operational simplicity.

Inventive Principle:
Principle #25Self-service

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 method allows for efficient production of ball forgings directly from scrap railway rails with a minimum number of cuts, enhancing production efficiency compared to die forging and casting processes, and reducing sensitivity to blank geometric accuracy.

Implementation Method 1

a blank (17) in the shape of a web of a railway rail is heated to a temperature appropriate for hot forming... the blank (17) is flow formed into an oval-shaped blank (17b)

Methodology Applied
Scientific EffectPlasticity: Plasticity

Implementation Method 2

the blank (17b) is flow formed into a bar (17c) with a circular cross-section

Methodology Applied
Scientific EffectPlasticity: Plasticity

Implementation Method 3

using the conical surfaces (21a, 21b) the cross-section of the bar (17c) is flow formed... using two cylindrical surfaces (22a, 22b) located behind the conical surfaces of the helical rolls (20a, 20b) the cross-section of the bar (17c) is calibrated

Methodology Applied
Scientific EffectPlasticity: Plasticity

Data Source

PatentEP4342598A1Method of rolling balls
Publication Date: 2024.03.27 FIRMA CODOGNI SPOLKA JAWNA
  • EP4342598A1 patent drawingFigure 1
  • EP4342598A1 patent drawingFigure 2
  • EP4342598A1 patent drawingFigure 3

AI summary

A method of rolling balls, especially from webs of scrap railway rails, characterized in that a blank (17) in the shape of a web of a railway rail is heated to the temperature appropriate for hot forming, after which the heated blank (17) is placed in grooves (2a) and (2b) of feeding rolls (1a) and (1b), then the feeding rollers (1a) and (1b) are set to rotate at the same speed (n1) and the blank (17) is moved towards a front guide (3) at a constant speed (V1), thereafter, grooved rolls of a first stand (5a) and (5b) are set to rotate at a constant speed (n2) in opposite directions, and grooved rolls of a second stand (11a) and (11b) are set to rotate at a constant speed (n3) in opposite directions, at the same time, guide rollers (15a) and (15b) are set to rotate at a constant speed (n4) in the same direction, and, at the same time, helical rolls (20a) and (20b) are set to rotate at equal speeds (n5) in the same direction, thereafter the blank (17) is guided into a guide hole (4) of a front guide of the first stand (3) and the blank (17) is moved towards the grooved rolls of the first stand (5a) and (5b), and the blank (17) is guided into oval-shaped grooves (6a) and (6b) located on the surface of the grooved rolls of the first stand (5a) and (5b), which have a depth (h1) less than half the height of the blank (17) and a width (b 1) greater than the thickness of the blank (17), while the diameter (D1) of both grooved rolls of the first stand (5a) and (5b) is the same, wherein axes of the both grooved rolls of the first stand (5a) and (5b) are located in a horizontal plane, and the distance between the axes of the both grooved rolls of the first stand (5a) and (5b) is equal to the diameter (D1) of the grooved rolls of the first stand (5a) and (5b).