Rail Foot Ball Rolling with Multi-Stand Groove Forming
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Solution Overview
Problem
Current methods for rolling ball forgings require high geometrical and dimensional accuracy in blanks, limiting the use of scrap railway rails and resulting in inefficient processes with multiple steps and complex roll shapes.
Innovation Solution
A method involving multiple stands with specific groove shapes and orientations to progressively form a blank from a railway rail foot into a ball, using heated blanks and coordinated roll movements to achieve efficient ball formation with minimal cuts and high accuracy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If traditional skew rolling process is used to produce balls from rail heads, then high production efficiency is achieved (160 balls/min for Ø30mm), but the billet requires high geometrical accuracy (diameter 0.97 of finished ball) and complex roll configurations (5-6 times larger diameter than ball)
Solution Approach 1:
The rolling process is divided into multiple stands (typically 3-4 stands) rather than using a single skew rolling mill. Each stand performs a specific shaping function, progressively transforming the rail head into a spherical shape. This segmentation reduces the precision requirements for each individual stand while maintaining high overall production efficiency.
Solution Approach 2:
The invention transitions from traditional skew rolling (with rolls inclined at 3°-7° to the billet axis) to longitudinal rolling with parallel axes. This dimensional change in the roll configuration allows for more flexible processing of irregular rail head shapes without requiring high initial billet precision.
2Adaptability or versatility
If multiple rolling stands with complex groove shapes are used to process scrap railway rails, then balls can be produced from irregular rail heads, but the device complexity increases significantly
Solution Approach 1:
The rolling stands are designed with universal grooved rolls that can process different types of rail heads (varying sizes and shapes) using the same basic equipment configuration. The grooves are designed to accommodate various rail profiles, reducing the need for specialized equipment for each rail type while maintaining adaptability.
Solution Approach 2:
The rolling process uses dynamically adjustable parameters (roll speeds, groove depths, stand configurations) rather than fixed complex structures. This allows the same equipment to adapt to different rail head geometries through parameter adjustment rather than physical reconfiguration, reducing device complexity.
3Reliability
If longitudinal rolling with parallel axes is used instead of skew rolling, then the rolling process becomes more stable and easier to control, but the ability to efficiently form spherical shapes from irregular blanks is reduced
Solution Approach 1:
The spherical formation process is segmented into multiple stands, each responsible for a specific stage of shaping. This segmentation allows the use of stable longitudinal rolling with parallel axes while maintaining efficient ball formation through the cumulative effect of multiple controlled deformation stages.
Solution Approach 2:
The rail heads undergo preliminary heating and positioning before entering the rolling stands. This preliminary preparation ensures that the material is in the optimal state for longitudinal rolling, enabling stable processing while efficiently achieving the desired spherical shape through the subsequent rolling sequence.
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
Enables direct rolling of balls from scrap railway rail feet with a reduced number of longitudinal stands, improving efficiency and reducing sensitivity to blank accuracy, while producing balls with a minimum number of cuts compared to die forging and casting processes.
Implementation Method 1
the blank is flow formed into a rhombus-shaped blank
Implementation Method 2
the rhombus-shaped blank is flow formed into an oval-shaped blank
Implementation Method 3
the blank with an oval-shaped cross-section is flow formed into a bar with nearly circular cross-section
Implementation Method 4
the bar is set to rotate at a constant speed in the direction opposite to the direction of rotation of the helical rolls
Implementation Method 5
the end of the bar is gripped with conical surfaces located in an entry zone of two helical rolls, which rotate with equal speeds in the same direction, and the bar is set to rotate at a constant speed in the direction opposite to the direction of rotation of the helical rolls, and using the conical surfaces the cross-section of the bar is flow formed
Implementation Method 6
helical protrusions located on the surfaces of the helical rolls were sunk into the cylindrical surface of the earlier calibrated bar
Implementation Method 7
annular grooves with spherical side surfaces were gradually formed on the bar
Data Source
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AI summary
A method of rolling balls, especially from feet of scrap railway rails, characterized in that a blank (30) in the shape of a section of a railway rail foot is heated to the temperature appropriate for hot forming, after which the heated blank (30) is placed in grooves (2a) and (2b) of feeding rollers (1a) and (1b), then the feeding rollers (1a) and (1b) are set to rotate at the same speed (n1) and the blank (30) 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, and grooved rolls of a third stand (17a) and (17b) are set to rotate at a constant speed (n4) in opposite directions, and grooved rolls of a fourth stand (13a) and (13b) are set to rotate at a constant speed (n5) in opposite directions, at the same time, guide rollers (27a) and (27b) are set to rotate at a constant speed (n6) in the same direction, and, at the same time, helical rolls (31a) and (32b) are set to rotate at equal speeds (n7) in the same direction, thereafter the blank (30) is guided into a guide hole (4) of a front guide (3) of the first stand and the blank (30) is moved towards the grooved rolls of the first stand (5a) and (5b), and the blank (30) is guided into trapezoid-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 (30).