Piston Cooling Duct Welding Using Temporary Pin Extraction
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Solution Overview
Problem
The existing method for producing pistons composed of upper and lower parts with a cooling duct is costly due to the need for a flow tube that must be mounted and stored, which increases assembly, storage, and logistics expenses.
Innovation Solution
A pin is used instead of a flow tube to keep the inlet and outlet openings free during welding, which is either securely connected to a clamping jaw or adjustable, allowing it to be withdrawn after welding, thus avoiding the need for a flow tube and reducing production costs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a flow tube is inserted into the piston lower part to keep the inlet opening free, then the opening remains unconstricted, but assembly costs and storage/logistics expenses increase
Solution Approach 1:
The patent removes the flow tube from the piston structure entirely. Instead of inserting a flow tube into the piston lower part, the invention uses a pin that is held out during welding and then withdrawn, eliminating the need for permanent flow tube installation and reducing assembly complexity while maintaining opening freedom
Solution Approach 2:
The pin used in the invention serves as a temporary, disposable element that is only needed during the welding process to hold out the opening. After welding, the pin is withdrawn and discarded, replacing the expensive, permanent flow tube with a cheap, temporary placeholder that eliminates storage and logistics costs
2Manufacturing precision
If a flow tube is mounted and adjusted to keep the inlet opening free, then the cross-section remains unrestricted, but production costs increase
Solution Approach 1:
The invention extracts the flow tube from the manufacturing process entirely. Instead of mounting and adjusting flow tubes to maintain opening cross-section, the process uses a temporary pin during welding that is then removed, achieving the same geometric result without the costly flow tube installation steps
Solution Approach 2:
The pin is held out from the piston lower part before and during the welding process to prevent welding beads from constricting the opening. This preliminary positioning action ensures the opening cross-section is maintained without requiring post-welding flow tube installation and adjustment
3Productivity
If welding beads are allowed to spread freely into the cooling duct, then the welding process is simpler, but the inlet opening cross-section is constricted
Solution Approach 1:
The pin acts as an intermediary element during welding, physically blocking the welding beads from spreading into the inlet opening while allowing the welding process to continue. This mediator prevents constriction of the opening cross-section without requiring complex control of the welding process itself
Solution Approach 2:
The pin is positioned in advance to counteract the harmful effect of welding bead spread. By holding out the pin before welding begins, the invention prevents the constriction problem before it occurs, allowing welding beads to spread freely elsewhere while protecting the opening cross-section
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 simplifies the production process and reduces costs by eliminating the need for flow tubes, ensuring the opening remains free without constricting the cross-section, thereby lowering the overall price of the piston.
Implementation Method 1
the piston upper part is welded with the piston lower part via a contact surface, in particular is friction-welded
Data Source
AI summary
A piston may include a piston upper part and a piston lower part. The piston upper part may be welded via a contact surface with the piston lower part forming a cooling duct therebetween. The cooling duct may define an inlet opening and an outlet opening extending from the piston lower part in the cooling duct. A welding bead may be formed within the cooling duct at each of the inlet opening and the outlet opening.