Cylinder Pipe Assembly With Cold-Formed Welded Connection
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Solution Overview
Problem
Existing methods for connecting a cylinder tube with a connecting piece, such as screw connections and welding, face challenges including mechanical strength, material efficiency, heat input, deformation, and contamination from machining processes.
Innovation Solution
A cylinder tube assembly featuring a cylinder tube with a connecting section that includes cold-formed concave stamping sections forming a structural hardening zone, and a connecting piece with a pressure medium tube, where the connection hole is enclosed by the structural hardening zone and the connecting piece is joined via a ring weld.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If a screw connection with internal thread is used in the cylinder tube, then the connecting piece can be securely attached, but the cylinder tube requires thicker wall or extensive machining to ensure sufficient mechanical strength
Solution Approach 1:
The invention divides the connection system into two separate parts: the cylinder tube and the connecting piece. The internal thread is relocated from the cylinder tube to the connecting piece, allowing each component to be optimized independently. The cylinder tube maintains its original wall thickness without machining, while the connecting piece incorporates the thread structure.
Solution Approach 2:
The threaded connection structure is extracted from the cylinder tube and transferred to the connecting piece. This extraction eliminates the need for machining the cylinder tube and preserves its material integrity, while the connecting piece independently provides the threading function.
2Strength
If conventional welding processes (TIG, MAG, or laser welding) are used to join the connecting piece to the cylinder tube, then a strong bond is achieved, but high heat input causes structural changes that adversely affect strength and can cause unwanted deformation
Solution Approach 1:
The invention replaces thermal welding processes with a mechanical press-fit connection. The connecting piece is pressed into the cylinder tube opening, creating a secure mechanical joint without applying heat. This eliminates thermal effects such as structural changes, heat-affected zones, and unwanted deformation while maintaining connection strength.
3Manufacturing precision
If holes or threads for pressure medium connection are created by machining (drilling or milling), then the connection bore can be precisely formed, but chips and dust become trapped inside the cylinder and contaminate the oil and peripheral components
Solution Approach 1:
The invention replaces machining processes (drilling, milling) with a press-fit insertion method. The connecting piece with its integrated thread structure is directly pressed into the cylinder tube opening, eliminating chip and dust generation. The connection bore is formed by the pressing action itself, maintaining precision without contamination.
Solution Approach 2:
The harmful machining process is extracted and replaced. Instead of removing material through drilling or milling, the connection is established through a cold-forming press-fit process that generates no chips or dust, thereby eliminating the contamination source.
4Productivity
If the connection hole opening forms a contour that直接接触 the inner cylinder surface, then the pressure medium can flow through, but it leads to increased wear of seals or guides on the piston
Solution Approach 1:
The invention introduces an intermediary structure: the connecting piece with its integrated thread structure serves as a mediator between the external connection and the internal pressure medium flow. The pressure medium flows through the connecting piece's internal passages rather than directly along the inner cylinder surface, preventing contact with seals and guides and eliminating wear.
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 provides a mechanically strong, material-efficient, and contamination-free connection that is resistant to deformation and heat damage, while also ensuring a smooth pressure medium flow and protecting sensitive components like seals and guides.
Implementation Method 1
the calottes are designed as cold-formed concave stamping sections and form a structural hardening zone in a forming area between the calottes
Implementation Method 2
form a structural hardening zone in a forming area between the calottes
Implementation Method 3
the connecting piece is joined via a ring weld
Data Source
Figure 1
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AI summary
The invention relates to a cylinder pipe assembly having a cylinder pipe (1) and a connection piece (2). The cylinder pipe (1) has a cylinder main body and a connection portion (1.3). The connection portion (1.3) has an outer shell calotte (3) on a cylinder pipe outer shell (1.1) and an inner shell calotte (4) on a cylinder pipe inner shell (1.2), and a structural consolidation zone and a connection perforation (5). The calottes (3, 4) are in the form of cold-formed concave embossed portions, wherein the structural consolidation zone (1.4) is arranged in a shaping region between the calottes (3, 4), wherein the connection perforation (5) is in the form of a punched hole and passes through the calottes (3, 4), and wherein the structural consolidation zone surrounds the connection perforation (5). The connection piece (2) is arranged at the connection portion (1.3) and has a pressure medium tube (6) and a connecting portion, wherein the connecting portion has an annular axial boundary contour (7.1), wherein the annular axial boundary contour (7.1) and an annular mating surface (3.1) of the outer shell calotte (3) form an annular touching contact surface, and wherein the cylinder pipe (1) and the connection piece (2) are connected in a materially bonded manner at the annular touching contact surface by means of an annular weld seam (8), and the annular weld seam (8) forms a sealing plane.