Hollow Valve Stem Internal Structuring for Improved Coolant Flow
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing methods for producing internally cooled one-piece valves with structured cavities and shafts are limited, as conventional techniques like broaching are not applicable to one-piece designs, and existing solutions do not effectively create structured internal surfaces in the shafts of hollow valves.
Innovation Solution
A method involving a structuring pear with external structuring is used to reshape the hollow shaft section of a valve preform, reducing the inner diameter and increasing the length, allowing for the imprinting of structures on the inner surface, which can be repeated with varying structuring bulbs to achieve complex internal geometries like helical patterns.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a broaching tool is used to cut a uniform structure into a hollow stem, then a structured internal surface is achieved, but this method cannot be applied to one-piece valves because the broaching tool cannot be pulled completely through the workpiece
Solution Approach 1:
Instead of pulling a broaching tool through the hollow stem from the outside, the patent inverts the approach by inserting a structuring element from inside the hollow stem and pulling it through from the interior. This allows the structuring action to occur while the tool is drawn through the workpiece from the inside out, making the process applicable to one-piece valves where external broaching is impossible.
2Shape
If the stem section is tapered to create a long, small-diameter stem from a short, large-diameter pipe section, then the desired valve geometry is achieved, but the inner diameter reduction must be coordinated with structuring bulb insertion
Solution Approach 1:
The patent combines the tapering process and the internal structuring process into a single integrated operation. The structuring element is inserted into the hollow stem before tapering, and both the stem geometry transformation and the internal surface structuring are achieved simultaneously during the same forming operation, rather than as separate sequential steps.
Solution Approach 2:
The structuring element is inserted into the hollow stem prior to the tapering operation. This preliminary insertion allows the structuring element to be in position before the forming action begins, so that as the stem is tapered and the inner diameter is reduced, the structuring element is automatically pressed against the internal surface and imprints the desired pattern.
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 enables the creation of internally cooled valves with enhanced cooling structures, such as helical patterns, that improve coolant flow and thermal management within the valve, addressing the limitations of existing techniques by allowing for precise internal structuring in one-piece valve designs.
Implementation Method 1
During withdrawal, the external structuring is at least partially pressed into the surface of the cavity
Implementation Method 2
at least a portion of an inner diameter of the cavity is reduced below the outer diameter of the structuring bulb
Data Source
Figure 1A~1H
Figure 2A~2F
Figure 3A~3G
AI summary
The present invention relates to a method for shaping a hollow valve preform by means of a tension rod (20) having a texturing head (22), which is inserted into the cavity (56) of a shaft portion (44) of a valve preform, the texturing head (22) having an outside diameter and an outside texture, whereupon the hollow shaft portion (44) is shaped, at least part of an inside diameter of the cavity (56) being reduced below an outside diameter of the texturing head (22), and then the texturing head (22) is pulled out through the shaped shaft portion (44), the outside texture being at least partially pressed into the surface of the cavity (56).