Laser Processing Nozzle Structure to Suppress Cooling Fluid Flow-Around
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In laser machining, reducing the diameter of the center hole in nozzles leads to increased distance between gas and fluid ejection holes, resulting in unstable cooling fluid flow and potential machining defects due to easier flow-around of cooling fluid between the nozzle tip and work, affecting tracking operation and accuracy.
Innovation Solution
A double nozzle design with an outer nozzle and inner nozzle, featuring a circumferential groove and inclined surface to deflect cooling fluid outward, preventing it from flowing around the nozzle tip and ensuring stable fluid flow and assist gas emission.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If the center hole diameter is reduced to form a small diameter nozzle, then the laser beam diameter can be reduced, but the distance between the inner wall of the center hole and the inner wall of the ejection hole increases, making it easier for cooling fluid to flow around between the nozzle tip and work
Solution Approach 1:
The patent applies local quality by creating an asymmetric structure where the ejection hole is positioned closer to the center hole on one side (downstream side) than on the other side (upstream side). This local variation in hole positioning compensates for the overall increased distance caused by smaller center hole diameter, ensuring that cooling fluid is ejected into a region where it cannot flow around between the nozzle tip and work, thereby maintaining machining accuracy while using a small diameter nozzle.
2Loss of energy
If the volume and pressure of assist gas are decreased, then energy consumption is reduced, but cooling fluid flow is less suppressed and cooling fluid is easier to flow around between nozzle tip and work
Solution Approach 1:
The asymmetric positioning of the ejection hole creates a local region with optimized cooling fluid ejection characteristics. By positioning the ejection hole closer to the center hole on the downstream side, the design ensures that cooling fluid is ejected into a region where it is naturally directed away from the gap between nozzle tip and work, reducing the need for high-volume, high-pressure assist gas to suppress cooling fluid flow, thereby maintaining machining accuracy with lower energy consumption.
3Temperature
If cooling fluid is ejected through the ejection hole, then excessive heat input into the work is suppressed, but cooling fluid may flow around between nozzle tip and work causing unstable tracking operation
Solution Approach 1:
The asymmetric ejection hole positioning creates a localized ejection pattern where cooling fluid is directed preferentially toward the downstream side. This local optimization ensures that cooling fluid effectively cools the workpiece while being naturally directed away from the gap between nozzle tip and work, preventing flow-around that would cause tracking instability, thus maintaining both temperature control and tracking reliability.
Solution Approach 2:
The asymmetric ejection hole structure acts as an intermediary mechanism that mediates between the need for effective cooling and the need for stable tracking operation. By positioning the ejection hole asymmetrically, it creates a flow pattern that naturally prevents cooling fluid from entering the tracking sensor gap, serving as a mechanical intermediary that resolves the conflict between cooling effectiveness and tracking stability.
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 design effectively suppresses fluid flow-around, maintaining machining accuracy and stability by ensuring the cooling fluid reaches the work surface without interfering with the assist gas, reducing defects in laser machining.
Implementation Method 1
spraying, to a work, cooling fluid that is mixture of air and cooling water and performing laser machining while cooling the work
Implementation Method 2
cooling fluid that is mixture of air and cooling water
Implementation Method 3
assist gas are emitted through the center hole
Implementation Method 4
volume and pressure of the assist gas
Data Source
Figure 1
Figure 2
Figure 3
AI summary
A nozzle (7) for laser machining is provided with a flange portion (7c) and formed in an annular shape, and includes a first communication hole (7e) communicating between a first end portion and a second end portion on a side opposite to the first end portion, a circumferential groove portion (7g) provided between the flange portion (7c) and the second end portion, and a plurality of second communication holes (74) communicating between a surface (7f) of the flange portion (7c) on a first end portion side and a side surface (7a2) of the circumferential groove portion (7g) on the first end portion side. A side surface (7b2) of the circumferential groove portion (7g) on a second end portion side extends so that the plurality of second communication holes (74) are invisible from the second end portion side.