Pressing Means for Thin-Walled Metal Pipe Fittings
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Solution Overview
Problem
Thin-walled metal pipes, especially copper pipes with a wall thickness of less than 1.2 mm, tend to form bulges during pressing with conventional tools, leading to leaky connections due to uneven material deformation, which reduces the bursting pressure strength when used with harder metals like steel and stainless steel.
Innovation Solution
Incorporating additional cams in the pressing contour, positioned at an angular range greater than 90° from the closing plane, and radial expansions between 10° and 90° on pressing webs to distribute deformation away from the critical closing plane, thereby enhancing the bursting pressure strength without increasing the risk of buckling.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional pressing tools are used on thin-walled metal pipes, then the pressing process can be completed, but bulges form in the closing plane area due to uneven material deformation
Solution Approach 1:
The pressing contour is segmented into multiple pressing sections (at least three pressing sections) distributed around the fitting circumference. Each pressing section independently deforms the fitting material, distributing the deformation load evenly and preventing concentration of stress in the closing plane area, thereby eliminating bulge formation.
Solution Approach 2:
The pressing elements are designed with different geometric characteristics at different locations. The pressing contour includes specific geometric features (such as radii and angles) that are optimized for local deformation requirements, allowing controlled material flow away from the closing plane while maintaining uniform deformation throughout the fitting.
2Shape
If the degree of deformation is reduced to prevent bulging, then bulge formation is minimized, but the bursting pressure strength and pull-out strength of the connection decreases
Solution Approach 1:
By segmenting the pressing contour into multiple pressing sections, the total deformation is distributed across multiple locations rather than concentrated in one area. This allows each pressing section to apply moderate deformation that prevents bulging while collectively achieving sufficient deformation to create strong mechanical interlocking and metal-to-metal contact for high bursting and pull-out strength.
Solution Approach 2:
The pressing contour is designed with specific three-dimensional geometric features (radii, angles, and depths) that deform the fitting material in multiple directions simultaneously. This multi-directional deformation approach achieves both bulge prevention and strength enhancement by creating complex deformation patterns that improve mechanical interlocking without excessive localized stress.
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 solution effectively reduces the risk of bulging and enhances the bursting pressure strength of the connection by shifting the deformation to a more radial direction, ensuring a secure and leak-proof seal.
Implementation Method 1
By pivoting the pressing elements toward one another, the material of the fitting, possibly together with sealant, and thereby also the material of the pipe, is deformed, so that a tight connection between the fitting and the pipe that is secure against extraction is created.
Data Source
Figure 1~2
Figure 3~4
Figure 5
AI summary
The invention relates to a pressing device for crimping a fitting for a sealing connection with a pipe, comprising at least two pressing elements (2, 4) with a receiving area for receiving a fitting with a pipe and with a pressing contour (10) formed on the inside of the pressing elements (2, 4), wherein the pressing elements (2, 4) are pivotably connected to one another, are spaced apart in an open position at the end (20, 22) having the pressing contour and, after completion of the crimping, have a smaller distance or are in contact with one another and thereby form a closing plane (24) and wherein the pressing contour (10) has a pressing area (26, 28, 30) for sealing crimping of the fitting and pressing ribs (36, 38) for fixing crimping of the fitting.The technical problem of improving the pressing of fittings with thin-walled metal pipes is solved by having at least one press rib (36, 38) of one of the press elements (4, 6) have a cam (40, 42) extending radially inwards.