Method and apparatus for harmonized energy in the workpiece machining zone

Abstract

The present invention relates to machining a workpiece, in which a pair of workpiece material and tool material is selected and the workpiece material is machined with the tool. Simultaneously with the machining, there is a step of providing an external, electrically charged gaseous medium to the machining zone, the contact between the workpiece and the tool. The formed charge polarity of the gaseous medium corresponds to the selected pair of workpiece material and tool material, and matches their generated internal thermal energy and charges, enthalpy levels and electrochemical reactions in the machining zone, workpiece and tool during the machining.

Description

【Technical Field】 【0001】 The present invention relates to machining a workpiece. In particular, the present invention relates to harmonizing the energy in the workpiece machining zone. 【Background Art】 【0002】 The modern goal of the metal cutting process is increased productivity of multiple machining operations. The only viable option is to increase productivity by increasing the cutting speed. However, this increase in cutting speed is known to cause an increase in cutting temperature and tool wear, among other important characteristics. 【0003】 Today, there are several new challenges in metal cutting. That is, a) increased use of special alloys with advanced properties and a significant tightening of quality requirements for machined parts, b) increasing global competition, c) environmental requirements for environmental improvement. Therefore, new solutions for the global metal cutting industry are sought. US5551324 discloses a method and apparatus for cooling a machining zone using an ionized gaseous fluid. GB2243319 and RU2004122051 disclose cutting apparatus in which the airflow is ionized. EP1875994 discloses a machining tool usable in the woodworking industry, which uses an ionized airflow. 【Summary of the Invention】 【0004】 The object of the present invention is to provide an alternative method for machining a workpiece. This object is achieved by the independent claims. The dependent claims illustrate various embodiments of the present invention. 【0005】 The method of the present invention for machining a workpiece includes a step of selecting a pair of the workpiece material and the tool material, and a step of machining the workpiece material using the tool. Simultaneously with the machining, there is a step of applying an external charged gaseous medium to the machining zone, the contact portion between the workpiece and the tool. The formed charge polarity of the gaseous medium is corresponding to the selected pair of the workpiece material and the tool material, and harmonizes the internally generated thermal energy, electric charge, enthalpy level, and electrochemical reaction in the machining zone, the workpiece, and the tool during machining. [Brief explanation of the drawing] 【0006】 The present invention will be described in more detail below with reference to the attached drawings. [Figure 1] This shows the source of thermal energy generation. [Figure 2] This demonstrates the principle of the EMF method. [Figure 3] This shows the basic configuration of a processing zone where a gaseous medium permeates all zones. [Figure 4] This shows the basic configuration of a processing zone where a gaseous medium permeates all zones. [Figure 5] (Figure 5a) Shows various neutralization mechanisms. (Figure 5b) Shows various neutralization mechanisms. (Figure 5c) Shows various neutralization mechanisms. [Figure 6] An example of neutralization current is shown. [Figure 7] An example of the relationship between average ion density and input pressure is shown. [Figure 8] This shows the temperature at various setup pressures. [Figure 9] Examples of test results from cutting test setups with carbon steel at various cutting speeds are shown. [Figure 10] The results of various cutting tests are shown. [Figure 11] The results of various cutting tests are shown. [Figure 12] The results of various cutting tests are shown. [Figure 13] The results of various cutting tests are shown. [Figure 14] The results of various cutting tests are shown. [Modes for carrying out the invention] 【0007】 Most known correlations between cutting speed, heat generation, and tool life have been investigated for many decades using numerous theories and models. The generated heat and thermal energy distribution are among the main topics, creating temperature fields in the workpiece, insert, and tool. There are three sources of thermal energy generation: I. the shear and deformation zone where the cut layer gradually transforms into an insert; II. the tool-insert interface where the insert slides along the rake face of the tool; and III. the tool-workpiece interface where the machined surface slides along a small area of ​​the tool's relief face. These sources are schematically shown in Figure 1. 【0008】 The strongest thermal energy generation, accounting for 65-90%, occurs in the shear / deformation zone, while 10-35% of the thermal energy is generated by friction at the tool-tip interface and tool-workpiece interface. In the machining of various steels, approximately 75-90% of the total thermal energy is generated by plastic deformation. However, the highest temperature is typically achieved at the tool-tip interface, and the temperature in front of the cutting edge at fracture is lower due to heat advection. 【0009】 The temperature achieved (thermal energy, balance between exothermic and endothermic heat) can be characterized by the electromotive force (EMF). Various methods and theories exist, including the Seebeck electromotive force caused by the joining of dissimilar metals, the Peltier electromotive force caused by the flow of current in a circuit, and the Thomson electromotive force resulting from the temperature gradient in the connected materials. The Seebeck electromotive force is dependent on the temperature of the joint, and this is known for any joint formed by the most common metals; therefore, if the resulting EMF is carefully measured, the joint of dissimilar metals can be used to measure temperature. Table 1 shows the thermoelectric electromotive forces for some commonly used materials. 【0010】 [Table 1] 【0011】 The table above shows the thermoelectric power (thermal emf) in absolute millivolts for several commonly used metals and alloys bonded with platinum. 【0012】 Figure 2 illustrates the principle of the EMF method. Since the tool material and workpiece material are typically different, their contact at the tool-tip interface and tool-workpiece interface forms a hot junction of the tool-workpiece thermocouple. The components of this thermocouple are insulated from the machine and fixture to eliminate noise in the output signal. This output signal is the EMF voltage, which is amplified and then sent to a data acquisition board plugged into a computer for further analysis. 【0013】 Machining is based on many techniques. However, atoms, molecules, and ions related to the material are always involved, and electromechanical, triboelectric, and electrochemical processes are active participants between the workpiece and the tool. In machining processes, especially in metal cutting, the workpiece typically loses electrons. At the atomic level, cutting a workpiece leads to an electrical process in which valence electrons leave the atoms of the workpiece as the cutting tool pushes forward, forming a charged zone in the workpiece. This weakens the workpiece's strength, eventually allowing it to be removed as cutting chips. This type of process occurs in the deformation zone, where most of the thermal energy is generated. Atoms lose electrons near the tool and form a positive electrical potential (cation), which requires a specific ionization energy level necessary to charge the material. This charging process is important in material cutting, and the resulting repulsive forces between ions in the workpiece lead to their removal from the workpiece material. Each different material has a characterized and unique ionization energy level. Therefore, a region of the deformation zone can be called an ionization region. 【0014】 The ionization process is important in metal cutting to continue this repetitive charging. The required ionization energy level depends on the pair of materials used, i.e., the workpiece and the tool, which mainly defines the required ionization energy, which is the force to remove or add electrons of atoms. In the case of metal cutting, atoms typically lose electrons. Depending on the electrochemical process, it can be exothermic or endothermic, and in those cases, thermal energy is released or absorbed. 【0015】 The conditions required for an electrochemical reaction are the collisions of the atoms, molecules, and ions of the reacting components with the material surface. When cutting metal, the atoms, molecules, and ions are in a gas-like state, the metal surface is in an elastoplastic phase, and an electrochemically active reaction between them is possible. The smaller the difference in level between the direct electrochemical reaction and the reverse electrochemical reaction, the less energy activation (ionization energy) is required. Therefore, it is important to optimize the balance of the electrochemical reaction (also, the balance of exothermic and endothermic) to minimize the required activation energy, which has a direct impact on the cutting force, heat distribution, elastic and plastic deformation. 【0016】 An electrical potential with fast variation appears on the contact surface between the workpiece and the tool. Therefore, the thermocouple phenomenon described above can be divided into two components: one steady and the other variable. The steady component is due to thermoelectric tension, while the variable component characterizes thermionic processes from surfaces in frictional contact. Thermoelectric current is greater than thermoelectronic current; for this reason, thermoelectric current is usually used to measure the average temperature of the cutting tool blade (see Seebeck), while thermoelectronic current has been less studied. Some prior art solutions have used an external power source by supplying a voltage level to the tool insert, creating a polarity effect in the cutting zone. This solution has some influence on machining. However, this method is not suitable for use in real industrial machinery due to the drawback that applying electricity to industrial machinery generates a lot of disruptive electrical interference. Another approach, using ionized air during metal cutting, has been proposed, and basic trials have been conducted. However, crucial facts regarding polarity and the relationship between selected workpiece and tool materials have not been presented, and this is a key topic for thermionic flow, internal charge control, neutralization, and ionic bonding. Consequently, there has been a lack of understanding of how to provide a robust and functional method for tuning and optimizing electromechanical and electrochemical reactions in machining. 【0017】 Based on the above description regarding activation energy and internal charges (thermoelectronic, thermoelectric, etc.) in machining and cutting, and the difficulty of increasing the machining speed with conventional metalworking fluids, etc., the present invention can provide a new level of machining results. This electromechanical and electrochemical invention is based on a method of harmonizing the activation energy of material processing and cutting, the internal charges on the contact surfaces, and the triboelectric energy on the material surface in order to minimize the resulting internal thermal energy, enthalpy level, cutting force, and tool wear, along with increased cutting speed and improved surface roughness. This harmonizing method is based on a generated and optimized external charged gaseous medium (flux) applied to the machining zone and the contact part between the workpiece and the tool, where the formed charge polarity of the gaseous medium corresponds to the selected pair of workpiece material and tool material and harmonizes the generated internal thermal energy, charges, enthalpy level, and electrochemical reactions during machining. The charged gaseous medium is a flow of ionized flux, where anionic ions or cationic ions are generated to simultaneously combine and harmonize the charge and electrochemical reactions of the materials in the machining zone. In order to harmonize the cationic polarity, anionic polarity, and enthalpy level on the machining zone, the selected material pair needs to have an optimized gaseous medium (flux). The gaseous medium may be based on an ionized air flux having more anions or more cations or a combination of anions and cations, and having a positive or negative polarity or bipolarity, depending on the selected pair of workpiece material and tool material. Also, other gaseous media, such as argon, nitrogen, or others, may be used depending on the selected pair of workpiece material and tool material in order to achieve a preferred ionic charge for machining zone harmonization. By using the ionized medium, the required ionization energy is minimized. 【0018】 The present invention is suitable for conductive, metallic, isolated, and coated materials, but also for non-conductive, non-metallic materials that contain high static charge and can be harmonized by ionic neutralization and / or recombination. The charged gaseous medium can penetrate all machining zones and all surfaces, including the tool, and affect surface energy, electron and atomic repulsion, surface oxidation, and ionic bonding or lattice formation, etc. The tool may consist of a tool holder, tool, insert, and other machining tools. 【0019】 Figures 3 and 4 below illustrate the basic configuration of the machining zone, which has a gaseous medium infiltrated into all zones and surfaces to harmonize machining and cutting energy through charge exchange and ionic bonding. Another figure shows the basic temperature distribution on the tool and workpiece (heat released due to energy conversion in the cutting zone), where primary (i), secondary (ii), and tertiary (iii) harmonizer zones are shown. In addition, depending on the material pair, harmonizing may be further performed on the surfaces of the tool and workpiece. The primary harmonizer zone is at the interface between the workpiece and the tool; therefore, the primary harmonizer zone does not have a negative influence on the internal shear and deformation zone in terms of elastoplastic deformation and its required heat generation (see: plastic deformation). Furthermore, depending on the selected workpiece and tool material pair, characterized ionic neutralization, recombination, or bonding has a positive influence on tool wear interactions, such as plastic deformation, texture changes, oxidation, and electrochemical reactions. In the cutting zone, the charged gaseous medium surrounding the workpiece and tool redistributes electrons in the metal as the medium's charge is constantly attracted toward the metal surface, interacting with the solid surface and the medium. In addition to the standard attractive interaction due to evanescent waves, there is also a repulsive interaction due to propagating Cherenkov waves. This fundamental electrodynamics must always be considered when dealing with charge distribution. 【0020】 When ionized atoms are projected onto a solid surface, an excited solid-atom system is formed. The ion neutralization process is the process by which this excited solid-atom system de-excites itself. 【0021】 The surface of a metal is represented by the femini level (εF, the electrochemical potential of electrons in the metal) and the vacuum level (εvac, the energy of unexcited (at rest) electrons in a vacuum, φ = work function). 【0022】 Various neutralization (de-excitation) mechanisms can occur: I) Resonance neutralization: Electrons in a metal band tunnel out from the surface to the excited state of an ion that is energetically degenerate to the surface state (Figure 5a). II) Auger neutralization: One electron in the metal band tunnels out from the surface into a more tightly bound state of the ion. Energy is conserved by the emission of a second (Auger) electron (Figure 5b) or photon (Figure 5c). 【0023】 Auger electrons exist within metal surfaces and can be excited beyond the vacuum level if the energy balance is positive. 【0024】 These processes are important because of the roles they play in secondary electron emission, gas discharge, and surface ionization mechanisms. The electron transitions involved in these processes are largely independent of the kinetic energy of the incident particle, but are governed by the excitation energy potential. 【0025】 Through experimental development of the relationship between current and cutting tool wear in the cutting zone, it was observed that when the workpiece is the anode (positive electrode) and the cutting tool is the cathode (negative electrode), the higher the cutting "thermal current," the greater the impact it has on the intensity of wear. The direction of the current depends on the selected workpiece and tool material pair. In one case, when an external current was applied directly to the tool at a certain voltage level, the incorrect polarity resulted in increased tool wear compared to a normal cutting setup. Therefore, understanding the selected material and polarity is crucial for optimizing a charged gaseous medium with the correct polarity. 【0026】 The movement of ions in an electric field constitutes an electric current, and its density depends on the number of ions in the air and the speed at which they move away from or towards the electric field source. The relationship between current density and electric field is known as the conductivity of air. This conductivity can vary with polarity. If an object is charged, an electric field is constructed around it. The strength of the electric field will vary from place to place, but it is always proportional to the charge. If an object is surrounded by air ions of both polarities, a flow carried by ions of the opposite polarity to its charge will flow towards the object. This neutralizing flow is proportional to both the charge on the object and the conductivity of the surrounding air. When a steel workpiece was cut with a basic tungsten carbide tool (insert), the neutralizing flow was measured using a highly sensitive Keithley measurement unit. In Figure 6, the average current level measured with the ionized gaseous medium was 0.75 mA, and the resonance range was 0.1 mA to 1.6 mA. The sample recording time was 65 seconds. The parameters and polarity of the ionized gaseous medium can be measured and optimized using the EMF test setup described above. 【0027】 The main parameters for ionized gaseous media are polarity, temperature, pressure of the ionized flux, and average ion density versus input pressure. Figures 7 and 8 show some basic values ​​for temperature versus pressure and ion density versus pressure. High ion density is required to have an effect on the cutting zone. The media temperature can be positive or negative, but it is typically cold, as cold temperatures support the current level in the cutting zone. 【0028】 The field in the surrounding air originating from a charged gas generates a neutralization current I-, which is also the total charge's decay or the rate of neutralization. 【0029】 【number】 During the ceremony 【number】 The time constant τ + teeth, 【number】 That is the case. 【0030】 For a given ionic environment, the equation gives the rate of neutralization by negatively charged air ions as a function of the geographical and dielectric positions of the charges. A similar symmetric equation applies to the neutralization of positive charges. 【0031】 The present invention was tested using several processing methods and materials. Typical methods were used to verify the test results. Some of the basic methods were mechanical, chemical, and visual tool wear analysis, such as flank wear and rake wear. Surface roughness of the processed surface was also a typical method. Another novel method was acoustic emission (AE) measurement, which can show material plastic deformation, tool wear, chip formation, etc. This is an interesting method for measuring the effect of harmonized cutting energy using an in-line method. This novel method using an acoustic force adjustment system can be used for gaseous medium optimization for various material pairs. Thermal energy can also be measured by the EMF method, but may be derived from force control results. 【0032】 The following drawings show the results of various cutting tests using Imatra520 round steel bars. Relief wear was compared between the emulsion and the method of the present invention, and the method of the present invention shows lower tool wear. Surface roughness is also improved by the invention. For acoustic emission (AE), the RMS signal was measured to compare friction values ​​among the various cutting methods. The method of the present invention achieved a lower friction signal and very stable results compared to other dry cutting methods. 【0033】 Table 2 below shows several cutting test setups using carbon steel at various cutting speeds. Coolant was compared to Eco Cooling (gaseous medium). The Ra value on the workpiece surface after cutting is at a better level. 【0034】 [Table 2] 【0035】 Figure 9 shows some tool wear results in this cutting test. The left side shows a tool insert with Eco Cooling (a gaseous medium), and the right side shows a tool insert with conventional coolant. A clear difference can be seen, with the use of conventional coolant resulting in much higher tool wear than with the charged gaseous medium. There is much evidence of similar improvements, and gaseous medium can achieve the same or better cutting quality and also improve tool life. 【0036】 And, the present invention is Steps to select a pair of workpiece material and tool material; The step of processing the workpiece with the tool; and, Simultaneously with the processing, a step of providing a pressurized, cooled, and ionized gaseous medium flow to the processing zone, wherein the ionization level and polarity of the gaseous medium correspond to the selected pair of workpiece and tool material, and harmonize the internal thermal energy and charge, enthalpy level, and electrochemical reactions generated in the processing zone, workpiece, and tool during the processing. This relates to a method for processing a workpiece, including the following. 【0037】 In the above method and apparatus, the ionization level and polarity of the gaseous medium can be controlled. Furthermore, in the above method and apparatus, the selection of the tool in the selection of the pair may include the selection of the tool shape and the tool material. 【0038】 Measurements of emf, internal charge (current, potential, electric field), AE, and other existing measurements can be used in the method and apparatus according to the present invention to optimize performance. The present invention has the capability to be implemented and utilized in several different machining methods, including milling, drilling, and cutting (including CNC and other multi-tasking machine tools). There are no limitations on applying this basic invention to multiple machining processes. 【0039】 From the above, it is clear that the present invention is not limited to the embodiments described in this document and can be implemented using many other different embodiments within the scope of the independent claims. The aspects relating to this disclosure also include the following aspects. <1> • Selecting a pair of workpiece material and tool material. • Processing the workpiece with the tool, A method for processing a workpiece, including, Simultaneously with the aforementioned processing, - Applying an external, charged gaseous medium to the machining zone and the contact area between the workpiece and the tool, wherein the charged polarity formed in the gaseous medium corresponds to the selected pair of workpiece and tool material, and harmonizes the internal thermal energy and charge, enthalpy level, and electrochemical reactions generated in the machining zone, workpiece, and tool during the machining process. The method characterized by the above. <2> The aforementioned charged gaseous medium is a flow of ionized flux. <1> Methods used. <3> The ionized flux is air, nitrogen, argon, or other gaseous medium, depending on the selected pair of workpiece material and tool material. <1> and <2> Methods used. <4> The charged gaseous medium has a temperature below 0°C or above 0°C, depending on the selected pair of workpiece and tool material. <1> ~ <3> Methods used. <5> The ionized flux is produced by corona AC / DC or alpha ionization, collision ionization or photoionization, or electrostatic spraying. <1> and <2> Methods used. <6> The gaseous medium has positive, negative, or bipolar polarity depending on the selected pair of workpiece and tool material. <1> and <2> Methods used. <7> The charged gaseous medium harmonizes the internal thermal energy, charge, and enthalpy level through ion neutralization, recombination, and ionic bonding on the processing zone, workpiece, and tool material. <1> Methods used. <8> The harmonization using a charged gaseous medium is performed in various zones, including the primary harmonization zone, the secondary harmonization zone, the tertiary harmonization zone, and the surfaces of the workpiece and the tool. <1> and <7> Methods used. <9> The selection of the workpiece material and tool material pair is made from the group consisting of conductive materials, non-conductive materials, or combinations thereof. <1> Methods used. <10> The selection of workpiece and tool material pairs can be partially or completely isolated or coated. <1> and <8> Methods used. <11> The selection of the tool in the selection of the pair of materials includes the selection of the tool shape and the tool material. <1> Methods used. <12> The tool consists of a tool holder, tool, insert, and other machining tools. <1> and <11> Methods used. <13> The ionized flux is optimized by a set of parameters and the function of their interactions (e.g., polarity of the ionized flux, temperature, pressure, mean ion density versus input pressure, temperature versus input pressure). <1> and <2> Methods used. <14> The ionization level and polarity of the charged gaseous medium are controlled. <1> Methods used. <15> The selection of the tool in the selection of the pair of materials includes the selection of the tool shape and the tool material. <1> or <2> Methods used. <16> Electromotive force (emf), internal charge (current, potential, electric field), AE, and / or other existing measurements are used for method optimization. <1> ~ <15> A method that uses any one of the following methods. <17> The charged gaseous medium minimizes cutting force and tool wear, along with increased cutting speed and improved surface roughness. <1> ~ <16> One of the methods described above.

Claims

[Claim 1] - Select a pair of materials for the workpiece and the tool. - Processing the workpiece with the tool, A method for processing a workpiece, including, Along with the aforementioned machining process, thermoelectron current and thermoelectric current data obtained by the EMF method between the workpiece and the tool are used to define the direction and polarity of the current, which are determined according to the selected pair of workpiece and tool materials. - To generate a charged gaseous medium, where the polarity of the gaseous medium is determined according to the selected pair of workpiece material and tool material. - Applying an external, charged gaseous medium to the machining zone, workpiece, and tool surfaces and interfaces, wherein the gaseous medium provides ion neutralization and / or recombination in the machining zone, workpiece, and tool during the machining process. - To measure the parameters and polarity of the charged gaseous medium, - Adjusting the ionization level and polarity of the charged gaseous medium, The method characterized by the above. [Claim 2] The method according to claim 1, wherein the charged gaseous medium is air, nitrogen, or argon, depending on the selected pair of workpiece material and tool material. [Claim 3] The method according to claim 1 or 2, wherein the charged gaseous medium is produced by corona alternating current / direct current or alpha ionization, collision ionization or photoionization, or electrostatic spraying. [Claim 4] The method according to claim 1, wherein the gaseous medium has positive polarity, negative polarity, or bipolarity depending on the selected pair of workpiece material and tool material. [Claim 5] The method according to claim 1, wherein the charged gaseous medium harmonizes the internal thermal energy, charge, and enthalpy level on the processing zone, the workpiece, and the tool material through ion neutralization, recombination, and ionic bonding. [Claim 6] The method according to claim 1, wherein the selection of the pair of workpiece material and tool material is made from the group consisting of conductive materials, non-conductive materials, or combinations thereof. [Claim 7] The method according to claim 1, wherein the selection of a tool in the selection of the pair of materials includes the selection of the tool shape and the material of the tool. [Claim 8] The method according to claim 1 or claim 7, wherein the tool comprises a tool holder, a tool, and an insert. [Claim 9] The method according to claim 1, wherein the charged gaseous medium is optimized by a set of parameters and the function of their interactions (e.g., polarity of the charged gaseous medium, temperature, pressure, average ion density versus input pressure, temperature versus input pressure). [Claim 10] The method according to any one of claims 1 to 9, wherein electromotive force (emf), internal charge (current, potential, electric field), and / or AE are used for method optimization. [Claim 11] The method according to any one of claims 1 to 10, wherein the charged gaseous medium minimizes cutting force and tool wear, along with increased cutting speed and improved surface roughness. [Claim 12] The method according to any one of claims 1 to 11, wherein the charged gaseous medium supports the resulting atomic repulsion force, thereby reducing the ionization energy of the workpiece.

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