Pipe Joint Structure Using Annular Protrusions Without Welding
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Solution Overview
Problem
The existing welding methods for joining piping members are time-consuming and costly due to the need for preparatory work, bead removal, and pickling, which increases the lead time and costs.
Innovation Solution
A joining structure is developed where annular protrusions on the inner peripheral surface of a cylindrical member bite into the outer peripheral surface of a pipe member, creating a firm seal without welding, using a pushing mechanism to concentrate radial inward force and reduce the required tightening torque.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If welding is used to join piping members, then the joining strength is sufficient, but the lead time increases and cost increases due to preparatory work, bead removal, and pickling
Solution Approach 1:
The patent replaces the welding process (thermal/chemical system) with a mechanical pressing system. A pressing means applies radial inward force to deform the cylindrical member's inner peripheral surface, causing annular protrusions to bite into the pipe member's outer peripheral surface, achieving joining without welding operations
Solution Approach 2:
The patent changes the physical state and geometric parameters of the cylindrical member through plastic deformation. The pressing means applies sufficient force to permanently deform the material, transforming the smooth inner peripheral surface into one with annular protrusions that mechanically interlock with the pipe member
2Strength
If welding is used to join piping members, then the joining strength is sufficient, but the cost increases due to additional processing steps
Solution Approach 1:
The patent replaces the welding process (thermal/chemical system) with a mechanical pressing system. A pressing means applies radial inward force to deform the cylindrical member's inner peripheral surface, causing annular protrusions to bite into the pipe member's outer peripheral surface, achieving joining without welding operations
Solution Approach 2:
The patent extracts and eliminates the complex welding process steps (preparatory work, bead removal, pickling) from the joining operation, retaining only the essential function of creating a strong mechanical connection through simplified pressing and deformation operations
3Strength
If the cylindrical member is pressed radially inward to form annular protrusions, then the joining strength improves, but the force required to push the cylindrical member increases
Solution Approach 1:
The patent converts the pressing force application from a purely radial direction to include an axial component. The pressing means applies force in both radial and axial directions, allowing the annular protrusions to form and bite into the pipe member while the axial component facilitates the pushing motion, thereby reducing the total force required
4Reliability
If the annular protrusion bites into the pipe member, then the sealability improves, but the force required to deform the cylindrical member increases
Solution Approach 1:
The patent converts the pressing force application from a purely radial direction to include an axial component. The pressing means applies force in both radial and axial directions, allowing the annular protrusions to form and bite into the pipe member while the axial component facilitates the pushing motion, thereby reducing the total force required
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 a more secure and cost-effective joining of pipe members without welding, enabling the use of large-diameter pipe members by reducing the force needed to push the cylindrical member and enhancing sealability.
Implementation Method 1
annular protrusions t are formed on an inner peripheral surface of the cylindrical member C, and a pressing means Pr is provided that presses a predetermined axial width d on the outer peripheral surface of the cylindrical member C radially inward... the annular protrusions t gradually bite into the outer peripheral surface of the pipe member P
Implementation Method 2
a pushing member that applies axial force to the cylindrical member... the cylindrical member is configured to generate radially inward force by the axial force of the pushing member
Data Source
AI summary
A joining structure airtightly or liquid-tightly joins an outer peripheral surface of the pipe member and an inner peripheral surface of a cylindrical member to be mounted on the pipe member, and the pipe member and the cylindrical member are made inseparable by an annular protrusion formed on the inner peripheral surface of the cylindrical member.