Aluminum Alloy Drill Pipe Threaded Connection Structure
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Solution Overview
Problem
The existing threaded connection between aluminum alloy drill pipes and steel joints is prone to loosening or screwing off during construction, requiring special facilities for assembly at high or low temperatures, which reduces efficiency and increases costs.
Innovation Solution
A connection structure featuring a first external threaded section with a smaller diameter and a second external threaded section with a larger pitch diameter, allowing for assembly at room temperature without special facilities, utilizing interference fit and thread galling to achieve high connection and sealing strength.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If hot assembly or cold assembly is used to connect aluminum alloy drill pipe and steel joint, then connection strength is improved, but assembly complexity and cost increase due to requiring special heating or cooling facilities
Solution Approach 1:
The invention changes the geometric parameters of the threaded connection by designing two different external threaded sections with different major diameters and pitch diameters. The first external threaded section has a smaller major diameter that fits within the first internal threaded section, while the second external threaded section has a larger pitch diameter that creates interference fit with the second internal threaded section. This parameter variation enables room temperature assembly without requiring thermal expansion or contraction facilities.
Solution Approach 2:
The threaded connection is segmented into two distinct external threaded sections and two corresponding internal threaded sections. The first threaded section provides the primary mechanical connection, while the second threaded section provides interference fit and thread galling. This segmentation allows each section to perform its specific function independently, achieving both connection strength and ease of assembly.
2Reliability
If interference fit and thread galling are used to prevent loosening, then reliability is improved, but manufacturing precision requirements increase
Solution Approach 1:
The invention applies different quality characteristics to different sections of the threaded connection. The first external threaded section is designed with precise dimensions for normal engagement, while the second external threaded section is designed with intentionally larger pitch diameter to create interference fit and thread galling. This local differentiation of quality requirements allows the critical first section to maintain high precision while the second section provides reliable anti-loosening through controlled interference.
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 design enables simple, efficient assembly of aluminum alloy and steel joints under room temperature conditions, reducing assembly costs and ensuring high screwing-off torque, thus preventing loosening and enhancing connection and sealing properties.
Implementation Method 1
a pitch diameter of the second external threaded section is larger than that of the second internal threaded section
Implementation Method 2
utilizing interference fit and thread galling to achieve high connection and sealing strength
Implementation Method 3
thread galling to achieve high connection and sealing strength
Data Source
AI summary
A connection structure between an aluminum alloy drill pipe body and a steel joint of an aluminum alloy drill pipe includes a first joint at an end of the aluminum alloy pipe body and a steel second joint; wherein the first joint includes a first external threaded section and a second external threaded section provided from outside to inside thereof, and a major diameter of the first external threaded section is smaller than that of the second external threaded section; and wherein the second joint includes a first internal threaded section which is able to be fitted with the first external threaded section and a second internal threaded section which is able to be fitted with the second external threaded section, and a pitch diameter of the second external threaded section is larger than that of the second internal threaded section.