Variable-Stroke Pipe Cutting Drive for Low-Deformation Cuts
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Solution Overview
Problem
Existing pipe cutting devices cause deformations in pipe walls due to tangential cutting, which are then rectified in a second stroke, leading to undesirable pipe section deformations.
Innovation Solution
A cutting device with a perforated, movable cutting die that performs circular and spiral movements via a drive lever and eccentric bearing system, allowing for continuous stroke adjustment and minimizing deformation by counteracting cutting forces with a cutting mandrel.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a two-stroke cutting mechanism is used to cut pipe sections, then the cutting die can be driven to vertical and horizontal lifting movements to complete the cut, but the pipe wall lying tangentially to the direction of movement is not cut but only deformed, resulting in deformations of the pipe wall in the deflected pipe sections
Solution Approach 1:
The cutting die is driven by a crank mechanism that converts rotational motion into oscillating cutting movements. The crank pin moves in a circular path, causing the cutting die to perform both vertical and horizontal cutting strokes simultaneously, eliminating the deformation issues of sequential two-stroke cutting while maintaining high cutting efficiency
Solution Approach 2:
The crank mechanism utilizes circular motion of the crank pin to generate the cutting path. The curved trajectory of the crank pin ensures that the cutting die follows a smooth oscillating path, applying cutting forces in multiple directions simultaneously to prevent pipe wall deformation while maintaining productivity
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 device reduces pipe wall deformation by enabling precise, continuous cutting movements that counteract bending forces, resulting in cleaner cuts and reduced pipe section deformation.
Implementation Method 1
The invention makes use of the idea of first providing a bearing in an outer shaft that is not arranged concentrically to the outer wall of the outer shaft but eccentrically in it. When the outer shaft rotates, the bearing executes an eccentric movement.
Data Source
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AI summary
The invention relates to a pipe cutting machine, comprising a hole-type movable cutting die (6b), which is driven by a drive lever (7), by means of which circular movements with a continuously variable stroke (h) can be performed, an eccentrically shaped crank pin bearing (26) in an outer shaft (18), in which a crank pin (11), which is arranged eccentrically on a crank pin drive (23), is movably supported in relation to the outer shaft (18), the crank pin (11) being in operative connection with the drive lever (7).