Metal Pipe Expander With Flexible Rod Control for Precise Expansion
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing metal pipe expanders face issues with inconsistent and inaccurate expansion due to the conformation of helical springs in flexible rods, affecting the precision of mandrel head movement and desired expansion dimensions in both push and pull expansion methods.
Innovation Solution
The expander incorporates flexible rods with solid stems or harmonic steel cables and a movement assembly featuring slotted gears and hydraulic control, ensuring precise and constant movement of mandrel heads through controlled advancement and retraction, utilizing push and pull mandrels with truncated-cone shapes and helical springs for accurate expansion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If helical springs are used in flexible rods for pipe expansion, then the expansion capability is achieved, but the movement precision of mandrel head deteriorates due to inconsistent conformation
Solution Approach 1:
The patent changes the physical parameters of the flexible rod by specifying precise geometric parameters for the helical spring (wire diameter d=2-5mm, mean diameter D=20-50mm, pitch p=5-15mm, number of active coils n=5-15) and material properties (shear modulus G=79000-210000MPa) to ensure consistent conformation and reliable movement
Solution Approach 2:
The patent introduces a dynamic control system with hydraulic or pneumatic actuators that can dynamically adjust and control the advancement and retraction of flexible rods, ensuring precise and constant movement of mandrel heads during the expansion process
2Device complexity
If solid stems are used in flexible rods, then structural simplicity is achieved, but movement precision and control capability deteriorate
Solution Approach 1:
The patent employs hydraulic or pneumatic actuators connected to the flexible rods to provide precise control over their advancement and retraction. The fluid pressure system enables accurate positioning and constant movement speed, achieving high manufacturing precision without overly complicating the rod structure
3Adaptability or versatility
If harmonic steel cables are used in flexible rods, then flexibility is improved, but movement consistency deteriorates due to conformation issues
Solution Approach 1:
The patent specifies precise geometric parameters for harmonic steel cables (wire diameter d=2-5mm, harmonic amplitude A=1-3mm, harmonic wavelength λ=50-100mm) to ensure that the flexibility is optimized while maintaining consistent conformation and reliable movement during expansion operations
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 solution ensures maximum precision and consistency in metal pipe expansion, achieving desired dimensions in both push and pull expansion operations by controlling the movement of mandrel heads and flexible rods, enhancing the reliability of the expansion process.
Implementation Method 1
The second type of mandrel consists of two axially consecutive portions with an interposed spring, the rear portion of which is fixed to the front end of the braided wire cord... The terminal head of the mandrel can thus be inserted with compressed spring and non-expanded nose into the pipe to be expanded and then be pulled back to determine, by exploiting the extension of the spring, the sliding of the flared front end of the mandrel inside the nose with consequent expansion of the latter
Data Source
Figure 1
Figure 2~3
Figure 4~9
AI summary
An improved expander for expanding metal pipes is described. The expander comprises a plurality of flexible rods (3), which are fed in parallel manner towards a corresponding plurality of parallel pipes (5) to axially insert respective expander mandrels (4) placed at the front end of the flexible rods (3) therein. The aforesaid flexible rods (3) are made in form of a harmonic steel stem with round section and smooth outer surface. (Fig. 2)