Pulsating Fluid Jet Device for Low-Pressure Machining
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Solution Overview
Problem
Conventional methods for machining workpieces with fluid jets require high pressures, leading to energy inefficiency and undesirable residues, while mechanical processing with cutting tools is expensive due to wear and does not efficiently remove coatings.
Innovation Solution
A device that generates pulsating fluid jets by adjusting the amplitude and frequency of pressure waves in the fluid jet, using a system with a chamber and nozzles, where the Helmholtz number is set to amplify pressure waves, allowing for efficient machining and coating preparation with lower fluid pressures.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If high fluid pressures (3000 bar or higher) are used for machining workpieces with fluid jets, then machining efficiency is improved, but energy consumption increases significantly
Solution Approach 1:
The patent applies ultrasonic vibration to the nozzle at frequencies between 20-100 kHz, causing the fluid jet to pulsate and vibrate. This vibrational energy enhances the cutting capability of the fluid jet, allowing efficient machining at lower pressures (20-30 bar) compared to conventional high-pressure methods (3000 bar), thereby reducing energy consumption while maintaining productivity
Solution Approach 2:
The patent employs periodic pulsation of the fluid jet through ultrasonic vibration of the nozzle. The periodic opening and closing of the nozzle orifice creates pulsating fluid jets that alternate between high-velocity discharge and pause phases, enhancing material removal efficiency through repeated impact cycles while operating at lower average pressures
2Productivity
If conventional fluid jet machining is used, then material can be removed, but undesirable residues are generated
Solution Approach 1:
The patent replaces conventional high-pressure mechanical fluid jet machining with ultrasonic-vibrated low-pressure fluid jet machining. The ultrasonic vibration mechanism substitutes for the need for extremely high fluid pressure, enabling effective material removal through vibrational enhancement rather than purely mechanical pressure-driven impact, thereby reducing harmful residues
3Productivity
If mechanical processing with cutting tools is used for hard materials, then chip removal is achieved, but cutting edge wear increases cost
Solution Approach 1:
The patent replaces mechanical cutting tools with an ultrasonic-vibrated fluid jet system. The fluid jet, enhanced by ultrasonic pulsation, removes material through erosion and cavitation mechanisms rather than mechanical cutting, eliminating cutting edge wear and associated costs while maintaining chip removal capability for hard materials
4Speed
If high pressure fluid jets are used, then machining speed is improved, but the system complexity increases
Solution Approach 1:
The patent introduces ultrasonic vibration (20-100 kHz) to the nozzle as a relatively simple additive component to achieve high machining speed. This vibrational mechanism enhances fluid jet performance without requiring complex high-pressure generation systems, maintaining simpler overall system architecture while improving machining speed
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
Enables efficient surface processing of workpieces with reduced energy consumption, effective removal of coatings, and improved adhesion of new coatings by converting vibrational energy into kinetic energy, enhancing the mechanical and thermal resilience of materials.
Implementation Method 1
a chamber (22) in which a pressure wave generating device (24) for generating fluid pressure waves (32) is formed
Implementation Method 2
the kinetic energy that can be transferred to the fluid by generating pressure waves can be maximized by ensuring that the reflections of pressure waves in a line system
Implementation Method 3
the quotient of the path length L for the fluid pressure waves between the outlet opening (34) of the chamber (22) and the at least one nozzle orifice (125) in the line system (36) and the wavelength λ of the fluid pressure waves (32) formed in the line system (36) Helmholtz number He: = L / λ can be adjusted
Implementation Method 4
at least one nozzle (38, 40) which has a nozzle orifice (125) from which a fluid jet of pressurized fluid can exit
Data Source
Figure 1
Figure 2
Figure 3~4
AI summary
The invention relates to a device (20) for generating a pulsating fluid jet (16, 18) from fluid subjected to pressure. The device (20) contains a line system (36) having at least one nozzle (38, 40), which has a nozzle orifice (125), from which a fluid jet (16) of fluid subjected to pressure can exit. The device (20) has a chamber (22), in which a pressure wave generation arrangement (24) for generating fluid pressure waves (32) is constructed. The chamber (22) communicates with the line system (36) through an exit opening (34) for the generated fluid pressure waves (32). According to the invention, the device (20) contains an adjusting arrangement (31, 47, 62, 64) for controlling the amplitude AP of the fluid pressure waves (22) in the line system (36) upstream of the at least one nozzle orifice (125). With the adjusting arrangement(31, 47, 62, 64), it is possible to adjust a Helmholtz number He:= L/? formed from the quotient of the path length L for the fluid pressure waves(22) in the line system (36) between the exit opening (34) of the chamber (22) and the at least one nozzle orifice (125) of the at least one nozzle (38, 40), and the wavelength ? of the fluid pressure waves (22) formed in the line system (36).