A method for local separation continuous high-speed ultrasonic vibration machining

Abstract

The present invention discloses a method for partially separated continuous high-speed ultrasonic vibration machining, which belongs to the field of mechanical machining technology. The method can make the partially separated continuous high-speed ultrasonic vibration machining further break through the limitation of critical feed rate on the basis of breaking through the critical cutting speed of fully separated intermittent high-speed ultrasonic vibration machining, and can realize dynamic variable cutting thickness through lateral vibration or lateral component vibration under continuous cutting of the cutting edge, so that the bottom surface of the chip and the machining surface produce a ridge structure, thereby generating a new cutting interface with partially separated ridges, which is convenient for the cutting fluid to enter the cutting area, and can reduce the cutting force and cutting heat during machining. Compared with the existing ultrasonic machining technology and ordinary machining technology, the present invention significantly improves the material removal rate and tool life under the premise of ensuring the machining quality, and can be applied to a variety of cutting machining processes, such as turning, milling, drilling and grinding, etc., to achieve efficient finishing and precision machining of complex parts of difficult-to-machine materials.

Description

Technical Field

[0001] The present invention belongs to the field of mechanical processing technology, and relates to ultrasonic vibration processing technology of difficult-to-process aerospace materials such as titanium alloys, deformed high-temperature alloys and powder high-temperature alloys in aerospace manufacturing, and in particular to a local separation continuous high-speed ultrasonic vibration processing method. Background Art

[0002] In the aerospace manufacturing sector, surface integrity characteristics are considered a key factor in evaluating the quality of the finished surface when critical manufacturing parts are machined with the goal of improving functional properties and service life. Aerospace manufacturers replace tools before reaching the generally accepted tool wear threshold defined by ISO standards (ISO 3685 for turning and ISO 8688 for milling) to eliminate the risk of surface damage caused by premature degradation of the cutting edge. For difficult-to-machine aerospace materials such as titanium alloys, wrought high-temperature alloys and powdered high-temperature alloys, finishing operations on aerospace parts are usually performed at relatively low cutting speeds due to the high cutting temperatures generated and the high strength exhibited during machining. The use of high-performance material cutting tools, various cooling and lubrication technologies, special machining processes and tool geometry optimization can improve machining efficiency or tool life to a certain extent, but they still cannot meet the needs of aerospace manufacturing. For many years, even at low cutting speeds, tool life was short and surface integrity was limited, which were two basic problems that limited the machinability of these materials in the finishing stage. Therefore, under the premise of giving priority to meeting surface quality requirements, improving tool life and machining efficiency is an urgent and eternal pursuit of the aerospace manufacturing industry.

[0003] Ultrasonic vibration machining is a special machining process that has many advantages for machining difficult-to-machine materials, but it always faces the problem of low machining efficiency. Traditional one-dimensional ultrasonic vibration machining and two-dimensional elliptical ultrasonic vibration machining have critical cutting speed limits, which restrict the increase in cutting speed. The cutting speed of ordinary machining has now exceeded these two vibration machining methods. The fully separated intermittent high-speed ultrasonic vibration cutting method breaks through the critical cutting speed limit and exponentially increases the cutting speed compared to existing ultrasonic vibration machining and ordinary machining. This method has a strong effect on improving tool life, but due to the small feed rate, the machining efficiency is still relatively low. Trajectory separation ultrasonic vibration machining fundamentally limits the improvement of ultrasonic vibration machining efficiency. In order to further improve the efficiency of ultrasonic machining, it is necessary to require that the trajectory is not separated. The cutting speed of difficult-to-machine materials is low, the continuous radial vibration tip has a large impact, the tool life is low, and the high-speed continuous ultrasonic radial vibration cutting method has narrow machining parameters and weak effects.

[0004] In summary, although the existing ultrasonic vibration machining technologies (conventional one-dimensional ultrasonic machining, two-dimensional elliptical ultrasonic machining, and fully separated intermittent high-speed ultrasonic machining (i.e., precision high-speed intermittent ultrasonic vibration cutting method)) have solved the machinability problem of difficult-to-machine materials in aerospace, they still have problems such as short tool life, low machining efficiency, and poor surface quality. Based on this, it is urgent to propose a new type of efficient machining technology suitable for difficult-to-machine materials in aerospace to solve the above problems. Summary of the invention

[0005] The purpose of the present invention is to provide a local separation continuous high-speed ultrasonic vibration processing method, which can significantly improve the tool life and processing efficiency while ensuring the processing quality, so as to solve the problems of short tool life, low processing efficiency and poor surface quality in the processing of difficult-to-process materials in aerospace.

[0006] To achieve the above object, the present invention provides the following solutions:

[0007] The present invention provides a local separation continuous high-speed ultrasonic vibration processing method, comprising:

[0008] Step 1: Install the ultrasonic vibration tool holder on the corresponding machine tool, so that the cutting edge of the cutting tool on the ultrasonic vibration tool holder generates lateral vibration or lateral component vibration along the feed direction in the tool base surface;

[0009] Step 2: According to the processing amount, reasonably match the ultrasonic vibration parameters and the cooling parameters, so that when the cutting tool is continuously cutting on the tool tip trajectory, the condition of local separation of the wave ridges is met between the tool rake face and the chip bottom surface, or between the tool flank face and the processing surface; wherein the processing amount is the three parameters of the cutting speed, feed rate and cutting depth of the cutting tool, the ultrasonic vibration parameters include the three parameters of amplitude, frequency and vibration form, and the cooling parameters include the three parameters of coolant type, coolant pressure and coolant application position;

[0010] Step 3: Turn on the cooling system, ultrasonic vibration system and machine tool to perform a continuous high-speed ultrasonic vibration processing process for partial separation of the workpiece by the cutting tool.

[0011] Optionally, the machine tool in step one is at least one of a lathe, a milling machine, a drilling machine, a grinder and a machining center.

[0012] Optionally, the cutting tool in step one includes at least one of a turning tool, a milling cutter, a drill bit, a grinding head, a reamer and a countersink.

[0013] Optionally, the ultrasonic vibration tool holder in step one includes at least one of a turning tool holder, a milling cutter holder, a drill bit holder, a grinding head holder, a reamer holder and a countersink holder.

[0014] Optionally, the cutting tool in step one is made of at least one of cemented carbide, ceramic, cermet, cubic boron nitride and diamond.

[0015] Optionally, when the partially separated continuous high-speed ultrasonic vibration processing method is combined with a turning method, it includes two methods: partially separated continuous high-speed transverse ultrasonic vibration turning and partially separated continuous high-speed elliptical ultrasonic vibration turning; when the partially separated continuous high-speed ultrasonic vibration processing method is combined with a milling method, it includes two methods: partially separated continuous high-speed elliptical ultrasonic vibration milling and partially separated continuous high-speed transverse ultrasonic vibration milling; when the partially separated continuous high-speed ultrasonic vibration processing method is combined with a grinding method, it includes two methods: partially separated continuous high-speed elliptical ultrasonic vibration grinding and locally separated continuous high-speed transverse ultrasonic vibration grinding. When the locally separated continuous high-speed ultrasonic vibration machining method is combined with a drilling method, it includes two methods: locally separated continuous high-speed elliptical ultrasonic vibration drilling and locally separated continuous high-speed transverse ultrasonic vibration drilling; when the locally separated continuous high-speed ultrasonic vibration machining method is combined with a reaming method, it includes two methods: locally separated continuous high-speed transverse ultrasonic vibration reaming and locally separated continuous high-speed elliptical ultrasonic vibration reaming; when the locally separated continuous high-speed ultrasonic vibration machining method is combined with a countersinking method, it includes two methods: locally separated continuous high-speed transverse ultrasonic vibration countersinking and locally separated continuous high-speed elliptical ultrasonic vibration countersinking.

[0016] Optionally, when the local separation continuous high-speed ultrasonic vibration machining method is used for external cylindrical turning, f>2A, and the vibration direction of the tool is parallel to the feed direction, the vibration equation of the tool is:

[0017] z = Asin(2πFt);

[0018] Among them, F is the ultrasonic vibration frequency, A is the actual ultrasonic vibration amplitude during turning, f is the feed rate, t is the time, θ is the angle corresponding to the arc between point D on the cutting edge and the tool tip, at point D on the cutting edge:

[0019] The nominal ridge heights of the chip bottom and the machined surface are:

[0020] h c =2Asinθ;

[0021] h s =2Asinθ;

[0022] The heights of the corrugations squeezed out of the chip bottom and the machined surface are:

[0023] h cE =2Bsinθ;

[0024] h sE =2Csinθ;

[0025] The residual wave ridge heights of the chip bottom and the machined surface are:

[0026] h cR =2(AB)sinθ;

[0027] h sR =2(AC)sinθ;

[0028] Among them, B and C are the amplitudes actually removed after extrusion and rebound at the nominal amplitude A;

[0029] The maximum separation gaps between the rake face and the chip bottom and between the flank face and the machined surface are:

[0030] C c =h cE ;

[0031] C s =h sE ;

[0032] The nominal wave period lengths of the chip bottom and the machined surface are:

[0033]

[0034] Among them, v ch is the chip flow velocity, v is the cutting speed;

[0035] The duty ratios of the separation phases between the rake face and the chip bottom and between the flank face and the machined surface are:

[0036]

[0037] Optionally, the condition for the local separation of the wave edge between the tool rake face and the chip bottom surface is:

[0038] 0<C c <G;

[0039] The conditions for local separation of corrugations between the tool flank and the machined surface are:

[0040] 0<C s <G;

[0041] Among them, G is the upper limit of the height of the squeezed ridges.

[0042] Optionally, the direction of the lateral vibration or the lateral component vibration in step one is perpendicular to the cutting speed of the cutting tool, and the vibration form of the lateral vibration or the lateral component vibration is one-dimensional vibration, two-dimensional vibration, three-dimensional vibration or elliptical vibration.

[0043] Optionally, the coolant type includes at least one of oil-based cutting fluid, oil-based cutting mist, water-based cutting fluid, water-based cutting mist, liquid nitrogen and air.

[0044] Optionally, in step three, after the cooling system is turned on, the coolant can be sprayed toward the cutting zone from the front face of the tool, the back face of the tool, or from both the front face of the tool and the back face of the tool.

[0045] Compared with the prior art, the present invention has achieved the following technical effects:

[0046] The local separation continuous high-speed ultrasonic vibration processing method proposed by the present invention is carried out according to the following steps: step 1, installing the ultrasonic vibration tool holder on the corresponding machine tool, so that the cutting edge of the cutting tool on the ultrasonic vibration tool holder generates lateral vibration or lateral component vibration along the feed direction in the tool base surface; step 2, according to the processing amount, reasonably matching the ultrasonic vibration parameters and cooling parameters, so that when the cutting tool is continuously cutting on the tool tip trajectory, the conditions of local separation of wave ridges are met between the tool rake face and the chip bottom surface, and / or between the tool flank face and the processing surface; wherein the processing amount is the three parameters of the cutting speed, feed rate and cutting depth of the cutting tool, the ultrasonic vibration parameters include the three parameters of amplitude, frequency and vibration form, and the cooling parameters include the three parameters of coolant type, coolant pressure and coolant application position; step 3, turning on the cooling system, the ultrasonic vibration system and the machine tool, and performing the local separation continuous high-speed ultrasonic vibration processing process of the cutting tool on the workpiece. Through the above steps, the partially separated continuous high-speed ultrasonic vibration machining can further break through the limitation of the critical feed rate on the basis of the fully separated intermittent high-speed ultrasonic vibration machining that breaks through the critical cutting speed, thereby completely breaking through the limitation of the critical cutting parameters and greatly improving the material removal rate. In the present invention, the dynamic variable cutting thickness is realized by lateral vibration or lateral component vibration under the continuous cutting of the cutting edge, so that the bottom surface of the chip and the processing surface produce a ridge structure, thereby generating a new cutting interface ridge partial separation, which helps the cutting fluid to enter the cutting area and can reduce the cutting force and cutting heat during the cutting process. Compared with the existing ultrasonic machining technology and ordinary machining technology, the present invention significantly improves the material removal rate and tool life under the premise of ensuring the machining quality, and can be applied to a variety of cutting machining processes, such as turning, milling, drilling and grinding, etc., to achieve efficient finishing and precision machining of complex parts of difficult-to-machine materials. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0048] Figure 1 It is a schematic flow chart of the local separation continuous high-speed ultrasonic vibration machining method disclosed in an embodiment of the present invention;

[0049] Figure 2 This is a schematic diagram of the cutting interface wave edge separation principle disclosed in an embodiment of the present invention;

[0050] Figure 3 for Figure 2 PP cross-section diagram;

[0051] Figure 4 for Figure 3 A schematic diagram of the enlarged structure at I in the middle;

[0052] Figure 5 It is a schematic diagram of the dynamic process of flank wave ridge extrusion and wave ridge separation;

[0053] Figure 6 This is a schematic diagram of the fluctuating surface of the insectivorous mouth edge of Nepenthes;

[0054] Figure 7 This is the principle diagram of local separation, wetting and viscosity reduction of the fluctuating interface at the mouth edge of Nepenthes;

[0055] Figure 8 A schematic diagram of a processed surface formed by a local separation continuous high-speed ultrasonic vibration processing method;

[0056] Fig. 9 A schematic diagram of a processed surface formed by an existing common processing method;

[0057] Fig.10 A schematic diagram of the bottom surface of the chip formed by the local separation continuous high-speed ultrasonic vibration machining method;

[0058] Fig.11 A schematic diagram of the bottom surface of the chip formed by the existing common processing method;

[0059] Fig.12 A comparison diagram of tool wear between the local separation continuous high-speed ultrasonic vibration machining method of the present invention and the conventional machining method;

[0060] Fig.13 This is a comparison diagram of the surface roughness Ra of the local separation continuous high-speed ultrasonic vibration processing method of the present invention and the conventional processing method;

[0061] Fig.14 A comparative diagram of the relationship between tool life and cutting speed of the local separation continuous high-speed ultrasonic vibration machining method of the present invention and the conventional machining method;

[0062] Fig.15 It is a schematic diagram of the principle of local separation continuous high-speed ultrasonic vibration turning disclosed in the second embodiment of the present invention;

[0063] Fig.16 It is a schematic diagram of the principle of local separation continuous high-speed ultrasonic vibration milling disclosed in the third embodiment of the present invention;

[0064] Fig.17 It is a schematic diagram of the principle of local separation continuous high-speed ultrasonic vibration grinding disclosed in the third embodiment of the present invention;

[0065] Fig.18 It is a schematic diagram of the principle of local separation continuous high-speed ultrasonic vibration drilling disclosed in the fourth embodiment of the present invention;

[0066] Fig.19 It is a schematic diagram of the principle of local separation continuous high-speed ultrasonic vibration reaming disclosed in the fourth embodiment of the present invention;

[0067] Fig. 20 It is a schematic diagram of the principle of local separation continuous high-speed ultrasonic vibration countersinking disclosed in the fourth embodiment of the present invention.

[0068] Wherein, the accompanying drawings are marked as follows:

[0069] 1. Workpiece; 2. Turning tool; 3. Milling cutter; 4. Grinding head; 5. Drill bit; 6. Reamer; 7. Countersink; 8. Insect leg; 9. Corrugated structure of the mouth edge; 10. Interface liquid film. DETAILED DESCRIPTION

[0070] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0071] One of the purposes of the present invention is to provide a local separation continuous high-speed ultrasonic vibration processing method, which can significantly improve tool life and processing efficiency while ensuring processing quality, so as to solve the problems of short tool life, low processing efficiency and poor surface quality in the processing of difficult-to-process materials in aerospace.

[0072] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0073] Embodiment 1

[0074] like Figure 1 As shown, this embodiment provides a local separation continuous high-speed ultrasonic vibration processing method, and its implementation steps include:

[0075] Step 1: Install the ultrasonic vibration tool holder on the corresponding machine tool, so that the cutting edge of the cutting tool on the ultrasonic vibration tool holder generates lateral vibration or lateral component vibration along the feed direction in the tool base surface; the combination of different ultrasonic vibration forms, different cutting processes and different shapes of parts can realize the processing of parts of different shapes by multiple cutting processes.

[0076] Step 2: According to the processing amount, reasonably match the ultrasonic vibration parameters and cooling parameters so that when the cutting tool is continuously cutting on the tool tip trajectory, the conditions for local separation of wave ridges are met between the front face of the tool and the bottom surface of the chip, and / or between the back face of the tool and the machined surface (that is, between the front face of the tool and the bottom surface of the chip, and between the back face of the tool and the machined surface, at least one of the two positions meets the conditions for local separation of wave ridges); wherein, "processing amount" refers to the three parameters of cutting speed, feed rate and cutting depth, and the parameter range includes all process conditions that can produce local separation of wave ridges between the tool and the chip, and between the tool and the machined surface. "Ultrasonic vibration parameters" refer to the three parameters of amplitude, frequency and vibration form, and the amplitude range includes all vibration conditions that can produce local separation of wave ridges between the tool and the chip, and between the tool and the machined surface. "Cooling parameters" refer to three parameters: coolant type, coolant pressure, and coolant application position. The coolant can be oil-based cutting fluid, oil-based cutting mist, water-based cutting fluid, water-based cutting mist, liquid nitrogen, or air. The coolant can be sprayed into the cutting area from the rake face of the tool, the flank face of the tool, or from both the rake face and the flank face of the tool. The coolant pressure is determined according to the machine tool conditions and process effect requirements.

[0077] Step 3: Turn on the cooling system, ultrasonic vibration system and machine tool to perform a local separation continuous high-speed ultrasonic vibration machining process.

[0078] In this embodiment, the "machine tool" mentioned in step 1 includes but is not limited to various machine tools such as lathes, milling machines, drilling machines, grinders and machining centers that can perform various cutting processes.

[0079] In this embodiment, the "ultrasonic vibration tool holder" described in step one can be of various types and specifications, including but not limited to ultrasonic vibration tool holders of various shapes and vibration forms suitable for different processes such as turning, milling, drilling, grinding, reaming, and countersinking and different parts processing parts.

[0080] In this embodiment, the "cutting tools" described in step one include but are not limited to turning tools 2, milling cutters 3, drill bits 5, grinding heads 4, reamer 6 and countersinks 7 that can perform various cutting processes. The tool material can be various types of materials such as cemented carbide, ceramics, cermets, cubic boron nitride, diamond, etc.

[0081] In this embodiment, the "cutting edge of the cutting tool generates lateral vibration or lateral component vibration along the feed direction in the tool base surface" in step 1. The direction of the lateral vibration or lateral component vibration is perpendicular to the tool cutting speed. According to different processing techniques, the actual situation is also different. For example, the lateral vibration of face turning is actually along the radial direction of the workpiece 1. The vibration form of "lateral vibration or lateral component vibration" can be one-dimensional vibration, two-dimensional vibration, three-dimensional vibration, etc.

[0082] In this embodiment, the "different cutting processing techniques" described in step one mainly include the following: (1) combined with the turning method, there may be two methods: partially separated continuous high-speed transverse ultrasonic vibration turning, and partially separated continuous high-speed elliptical ultrasonic vibration turning; (2) combined with the milling method, there may be two methods: partially separated continuous high-speed elliptical ultrasonic vibration milling, and locally separated continuous high-speed transverse ultrasonic vibration milling; (3) combined with the grinding method, there may be two methods: partially separated continuous high-speed elliptical ultrasonic vibration grinding, and locally separated continuous high-speed transverse ultrasonic vibration grinding; (4) combined with the drilling method, there may be two methods: locally separated continuous high-speed elliptical ultrasonic vibration drilling, and locally separated continuous high-speed transverse ultrasonic vibration drilling; (5) combined with the reaming method, there may be two methods: locally separated continuous high-speed transverse ultrasonic vibration reaming, and locally separated continuous high-speed elliptical ultrasonic vibration reaming; (6) combined with the countersinking method, there may be two methods: locally separated continuous high-speed transverse ultrasonic vibration countersinking, and locally separated continuous high-speed elliptical ultrasonic vibration countersinking.

[0083] In this embodiment, the “separation” of “partial separation of wave ridges” in step 2 refers to wave ridge separation, which is not the separation of the tool tip trajectory, but the wave ridge separation between the front cutting edge of the tool and the bottom surface of the chip, and between the back cutting edge of the tool and the processing surface. It is a surface-to-surface separation, and the tool tip is not separated. For ordinary machining, although the tool itself has a back angle, the inevitable back cutting edge wear during machining makes the actual back angle of the tool 0°. During the entire tool life, the back cutting edge is always in close contact with the processing surface. In ordinary machining, the chips flow closely to the front cutting edge, and the front cutting edge of the tool and the bottom surface of the chip are always in close contact. As Figure 2 to Figure 5The figure shows the principle diagram of wave separation at the cutting interface. In the technical solution, there are two stages in a wave generation cycle: wave separation and wave extrusion. In the wave extrusion stage of a wave generation cycle, the cutting edge will interfere and extrude the wave that has been generated while the current wave is generated; in the wave separation stage of a wave generation cycle, a gap is generated between the wave generated while the current wave is generated and the wave after interference, extrusion and rebound, and then the surface is separated, but the cutting edge is not separated. The wave separation of the front and rear cutting edges of the cutting tool periodically opens the cutting area between the bottom surface of the chip and the front cutting edge of the tool, and between the back cutting edge of the tool and the machining surface, making it easier for the cutting fluid to enter the cutting area to improve the cutting conditions of the tool and the machining surface, increase lubrication, reduce friction and cool, which is beneficial to improving the tool life and the surface quality of the workpiece.

[0084] The aforementioned local separation continuous high-speed ultrasonic vibration machining method utilizes the local separation principle to generate microscopic gaps to promote the cutting fluid to enter the cutting zone to achieve the purpose of lubrication and viscosity reduction, which is similar to the local separation lubrication and viscosity reduction of the wavy interface at the mouth edge of the pitcher plant. Figure 6 The figure shows the undulating surface of the insectivorous mouth of Nepenthes, which is covered with wavy ridge structures. Figure 7 As shown in the figure, when the insect foot steps on the wave-shaped structure of the pitcher plant's mouth, a partially separated microchannel will be formed between the insect foot and the wave-shaped structure. The pitcher plant improves its ability to catch insects by filling liquid into the microchannel to form an interfacial liquid film to increase the lubrication effect. Figure 8 and Fig. 9 As shown, the processed surface structures are respectively formed by the local separation continuous high-speed ultrasonic vibration processing method of the present technical solution and the ordinary processing method. The processed surface formed by the local separation continuous high-speed ultrasonic vibration processing method of the present technical solution has obvious ridge structure, which proves the existence of ridge separation in the local separation continuous high-speed ultrasonic vibration processing of the present technical solution.

[0085] Take external turning as an example, Fig.15 As shown, f>2A, when the vibration direction of the tool is parallel to the feed direction, the vibration equation of the tool is:

[0086] z=Asin(2πFt)

[0087] Where F is the ultrasonic vibration frequency, A is the actual ultrasonic vibration amplitude during turning, f is the feed rate, and t is the time. θ is the angle of the arc between point D on the cutting edge and the tool tip. At point D on the cutting edge:

[0088] The nominal wave height of the chip bottom and the machined surface is determined by the vibration amplitude and is:

[0089] h c =h s =2Asinθ

[0090] The heights of the corrugations squeezed out of the chip bottom and the machined surface are:

[0091] h cE =2Bsinθ

[0092] h sE =2Csinθ

[0093] Both wave ridge generation and wave ridge extrusion are determined by ultrasonic vibration. From the perspective of vibration trajectory, the generated wave ridges will be completely extruded and removed. However, due to the rebound of the material, a certain wave ridge height will remain after extrusion. Therefore, the actual extruded wave ridge height is less than the nominal wave ridge height. B and C are the amplitudes actually removed after extrusion and rebound at the nominal amplitude A.

[0094] The residual wave ridge heights of the chip bottom and the machined surface are:

[0095] h cR =2(AB)sinθ

[0096] h sR =2(AC)sinθ

[0097] The maximum separation gaps between the rake face and the chip bottom and between the flank face and the machined surface are:

[0098] C c =h cE

[0099] C s =h sE

[0100] The nominal wave period lengths of the chip bottom and the machined surface are:

[0101]

[0102] Among them, v ch is the chip flow velocity and v is the cutting speed.

[0103] The duty ratios of the separation phases between the rake face and the chip bottom and between the flank face and the machined surface are:

[0104]

[0105] In this embodiment, in step 2, the vibration parameters and cooling parameters are reasonably matched according to the processing amount, that is, the conditions for wave ridge separation (wave ridge height, wavelength and blade contact length, interference extrusion depth) can be reasonably matched under the condition of continuous cutting on the tool tip trajectory, so as to produce better cutting interface lubrication, viscosity reduction and cooling effects. Specifically, the condition for local separation of wave ridges between the tool rake face and the chip bottom surface is: 0<C c<G, the condition for local separation of wave edges between the tool back face and the machined surface is: 0<C s <G. Among them, C c and C s They are the maximum separation gaps between the front cutting edge and the bottom surface of the chip, and between the back cutting edge and the machined surface. The wave ridges come from vibration. As the amplitude of ultrasonic vibration increases, the nominal wave ridge height increases, and the height of the squeezed wave ridges also increases. The maximum separation gaps between the front cutting edge of the tool and the bottom surface of the chip, and between the back cutting edge of the tool and the machined surface increase, and the ability of the coolant to enter the cutting zone is enhanced, and the lubrication, viscosity reduction and cooling effects are enhanced. However, there is an optimal value for the wave ridge height. Too much vibration impact can easily lead to chipping of the tool tip. The aforementioned G is the upper limit of the squeezed wave ridge height.

[0106] Through the above steps 1, 2 and 3, this technical solution can realize local separation continuous high-speed ultrasonic vibration processing in the process of cutting and processing difficult-to-process materials in aerospace, etc., completely breaking through the feed limit of the cutting edge separation produced by the full separation intermittent high-speed ultrasonic vibration cutting method (i.e., the precision high-speed intermittent ultrasonic vibration cutting method), and dynamically changing the cutting thickness through the lateral vibration or lateral vibration component in the processing surface perpendicular to the cutting speed under the continuous cutting of the cutting edge, so that the bottom surface of the chip and the processing surface produce a ridge structure, thereby producing a new cutting interface ridge local separation, completely breaking through the limitations of critical cutting parameters (cutting speed, feed rate, cutting depth), and compared with the existing ultrasonic processing technology (traditional one-dimensional ultrasonic processing, two-dimensional elliptical ultrasonic processing, full separation intermittent high-speed ultrasonic processing) and ordinary processing technology, the material removal rate is greatly improved. The periodic opening and closing ridge structure increases the ability of the coolant to enter the cutting area, so that the cutting technology of this technical solution has many advantages over the existing technology, such as reduced cutting force and cutting heat, extended tool life, reduced processing cost, optimized surface quality and improved processing quality. The advantages of the above-mentioned local separation continuous high-speed ultrasonic vibration processing method of the technical solution are specifically described below:

[0107] ① The advantages of traditional one-dimensional ultrasonic vibration cutting and elliptical ultrasonic vibration cutting are both obtained at extremely low cutting speeds; this technical solution breaks through the maximum cutting speed limit of traditional one-dimensional ultrasonic vibration cutting and elliptical ultrasonic vibration cutting. The advantages of fully separated intermittent high-speed ultrasonic vibration cutting are all obtained at a feed rate of several microns per revolution; this technical solution breaks through the feed rate limit of fully separated intermittent high-speed ultrasonic vibration cutting. This technical solution, through the application of the above-mentioned local separation continuous high-speed ultrasonic vibration processing method, can produce wave-edge separation between the tool and the chips and between the tool and the workpiece. The cutting fluid enters the separation zone to reduce temperature and wear and increase tool life, thereby still obtaining the advantages of separated vibration cutting.

[0108] ② Open part of the cutting area and improve the force and heat conditions in the cutting area. In the normal cutting process, the rake face of the cutting tool is always in contact with the bottom of the chip. The inevitable wear of the back face makes the actual tool back angle 0°. The back face is also always in contact with the machined surface, so it is difficult for the coolant to enter. Figure 2 to Figure 5 This is the principle diagram of wave separation at the cutting interface. There are two stages in a wave generation cycle: wave separation and wave extrusion. In the wave extrusion stage of a wave generation cycle, when the current wave is generated, the tool face will interfere with and extrude the wave that has already been generated. In the wave separation stage of a wave generation cycle, when the current wave is generated, a gap is generated between the tool face and the wave that has been interfered, extruded and rebounded, so that the surface is separated, but the tool tip is not separated. The wave separation between the front and rear tool faces periodically opens the cutting area between the bottom surface of the chip and the front tool face, and between the back tool face and the machined surface, making it easier for the cutting fluid to enter the cutting area to improve the cutting conditions of the tool and the machined surface, increase lubrication, reduce friction and cool, reduce force and heat, and is beneficial to improving the tool life and the surface quality of the workpiece.

[0109] ③This technical solution breaks through the limit of ordinary cutting speed. Ordinary cutting has poor cooling effect, which leads to serious heat accumulation during high-speed cutting and accelerated tool wear. Therefore, ordinary cutting speed can only ensure a certain tool durability in the low-speed cutting area of ​​the corresponding material and the corresponding processing technology, which greatly limits the processing efficiency. The local separation continuous high-speed ultrasonic vibration processing of this technical solution has good cooling effect and avoids heat accumulation. Under the same tool durability or surface quality, the cutting speed can reach several times of ordinary cutting and enter the high-speed cutting area of ​​the corresponding material and the corresponding processing technology, thereby significantly improving the cutting efficiency. See. Fig.14 .

[0110] ④ The local separation continuous high-speed ultrasonic vibration machining method of this technical solution can delay tool wear and increase tool life. Fig.12 and Fig.13 As shown, compared with ordinary cutting, at cutting speed v = 80m / min, cutting depth a p =0.2mm, feed rate f=0.1mm / r, 80bar high pressure cooling, in the experiment of turning GH4169 (precipitation strengthened nickel-based high temperature alloy) with coated carbide tool, the local separation continuous high-speed ultrasonic vibration machining method can significantly delay the tool wear rate, when the blunting standard is defined as VB max When VB = 0.3 and Ra = 0.8, the tool cutting distance can be increased by 82.5%. max The Chinese meaning of is the maximum wear amount on the back face of the tool.

[0111] ⑤ The local separation continuous high-speed ultrasonic vibration processing method of this technical solution can improve the processing efficiency. Fig.14 As shown, VB max=0.3 and Ra=0.8 are used as the failure criteria for finishing. Under the same cutting distance conditions, compared with ordinary cutting, the failure rate of finishing is p =0.2mm, feed rate f=0.1mm / r, 80bar high pressure cooling conditions, the coated carbide tool turned GH4169 (precipitation strengthened nickel-based high temperature alloy), the local separation continuous high-speed ultrasonic vibration machining method increased the machining efficiency by 1.33 times. The local separation continuous high-speed ultrasonic vibration machining with a cutting speed of 140m / min and the conventional machining with a cutting speed of 60m / min can cut the same distance / remove the same volume of workpiece material under the same tool wear.

[0112] ⑥ The local separation continuous high-speed ultrasonic vibration processing method of this technical solution can be applied to a variety of cutting processing processes, such as turning, milling, drilling and grinding, to achieve efficient finishing and precision processing of complex parts of difficult-to-process materials.

[0113] It can be seen that the present technical scheme, through the application of the above-mentioned local separation continuous high-speed ultrasonic vibration machining method, enables the local separation continuous high-speed ultrasonic vibration machining to further break through the critical feed rate limitation on the basis of breaking through the critical cutting speed of the full separation intermittent high-speed ultrasonic vibration machining, so that wave-edge separation is generated between the tool and the chips, and between the tool and the workpiece. The cutting fluid enters the separation zone to cool down and reduce wear, which can reduce the cutting force and cutting heat in the cutting of various aerospace difficult-to-machine materials, thereby greatly improving the tool life, material removal rate and machining quality.

[0114] The application scope of the above-mentioned local separation continuous high-speed ultrasonic vibration machining method in this technical solution includes precision machining and finishing. Fig.12 , Fig.13 and Fig.14 In actual processing, it is necessary to reasonably match the vibration parameters (vibration form, vibration frequency, vibration amplitude) and ultrasonic toolholder type specifications according to the cutting parameters (cutting speed, feed rate and cutting depth), workpiece and tool materials, and the internal and external contours of the parts to meet the wave edge separation conditions and toolholder accessibility requirements.

[0115] Embodiment 2

[0116] The flowchart of the local separation continuous high-speed ultrasonic vibration processing method of embodiment 1 is as follows: Figure 1 As shown, it is suitable for turning, milling, grinding, drilling, reaming and countersinking. In order to better explain the present invention and facilitate understanding, the following is combined with the attached Fig.15 , the present invention is described in detail through specific implementation mode 1.

[0117] Implementation method 1: Partial separation continuous high-speed ultrasonic vibration turning method, suitable for external turning, end turning, internal hole turning, grooving, external cylindrical profiling, external cylindrical grooving, internal hole profiling and internal hole grooving, etc. Fig.15 The external turning principle based on this method is shown, which includes the following steps:

[0118] Step S1: clamp the workpiece 1 onto the spindle of the lathe.

[0119] Step S2: Setting cutting parameters. Specifically, as an example, a coated carbide turning tool (turning tool 2) is used to perform external cylindrical finishing on FGH96 (an existing alloy), with a cutting speed of 80 m / min, a feed rate of 0.2 mm / r, and a cutting depth of 0.1 mm.

[0120] Step S3: Select an ultrasonic turning tool holder. Select the vibration mode according to the cutting part of the workpiece 1 and choose a suitable ultrasonic turning tool holder. When the cutting part of the part is a single straight line trajectory, single-direction vibration is preferred. When the cutting part of the part is a complex shape, multi-directional composite vibration is selected. When the vibration direction is transverse ultrasonic vibration, its vibration direction is parallel to the feed direction of the turning tool 2. When the vibration direction is elliptical ultrasonic vibration, its vibration direction is a synthesis of vibration components parallel to the feed direction and parallel to the cutting depth direction, and its vibration plane is parallel to the tool base surface (the condition that the cutting edge generates transverse vibration or transverse component vibration along the feed direction in the tool base surface is satisfied). For the example in step S2, a transverse vibration ultrasonic turning tool holder can be selected.

[0121] Step S4: Setting vibration parameters. According to the cutting parameters, the vibration parameters can be set as follows: the vibration direction is lateral, the vibration frequency is 20 kHz, and the single-side vibration amplitude is 6 um.

[0122] Step S5: Setting cooling parameters. For the example in step S2, a water-soluble emulsion with a concentration of 8% is selected and sprayed onto the rake face, the flank face, or both the rake face and the flank face at a pressure of 50 bar.

[0123] Step S6: Turn on the high-pressure cooling system, turn on the ultrasonic vibration system, and turn on the machine tool to complete the local separation continuous high-speed ultrasonic vibration turning.

[0124] Embodiment 3

[0125] The flowchart of the local separation continuous high-speed ultrasonic vibration processing method of embodiment 1 is as follows: Figure 1 As shown, it is suitable for turning, milling, grinding, drilling, reaming and countersinking. In order to better explain the present invention and facilitate understanding, the following is combined with the attached Fig.16 and 17 , the present invention is described in detail through specific implementation mode 2.

[0126] Embodiment 2: Partial separation continuous high-speed ultrasonic vibration milling / grinding processing method, such as Fig.16 and 17 Shown is the milling / grinding principle based on this method, which includes the following steps:

[0127] Step S1: Fix the workpiece 1 on the workbench of the milling / grinding machine.

[0128] Step S2: Setting cutting parameters. Specifically, as an example, a coated carbide tool is used to perform face milling on TC4 (a titanium alloy material), with a cutting speed of 120 m / min, a feed per tooth of 0.04 mm / tooth, a radial cutting width of 12 mm, and an axial cutting depth of 0.2 mm.

[0129] Step S3: Select ultrasonic milling / grinding toolholder. Fig.16 When the end face is milled using the bottom edge of the milling cutter 3, the vibration direction of the tool is elliptical ultrasonic vibration, and there is a vibration component of the elliptical ultrasonic vibration that is perpendicular to the cutting speed direction of each tooth of the milling cutter 3; when the milling cutter 3 is used to mill the fillet, the vibration direction of the tool is transverse ultrasonic vibration, and the ultrasonic vibration is perpendicular to the cutting speed direction of each tooth of the milling cutter 3. Fig.17 When the side abrasive grains of the grinding head 4 are used to grind the side of the workpiece 1, the vibration direction of the grinding head 4 is elliptical ultrasonic vibration, and the elliptical ultrasonic vibration has a vibration component perpendicular to the cutting speed direction of each abrasive grain of the grinding head 4; when the end abrasive grains of the grinding head 4 are used to grind the end face of the workpiece 1, the vibration direction of the grinding head 4 is transverse ultrasonic vibration, and the transverse ultrasonic vibration is perpendicular to the cutting speed direction of each abrasive grain of the grinding head 4. For the example in step S2, an elliptical ultrasonic vibration milling cutter handle can be selected.

[0130] Step S4: Setting vibration parameters. According to the cutting parameters, the vibration parameters can be set as follows: the vibration direction is elliptical, the vibration frequency is 20 kHz, and the single-side vibration amplitudes of the two paths are 4 um each.

[0131] Step S5: Setting cooling parameters. For the example in step S2, a water-soluble emulsion with a concentration of 8% is selected and sprayed onto the rake face, the flank face, or both the rake face and the flank face at a pressure of 50 bar.

[0132] Step S6: Turn on the high-pressure cooling system, turn on the ultrasonic vibration system, and turn on the machine tool to complete the local separation continuous high-speed ultrasonic vibration milling / grinding.

[0133] Embodiment 4

[0134] The flowchart of the local separation continuous high-speed ultrasonic vibration processing method of embodiment 1 is as follows: Figure 1As shown, it is suitable for turning, milling, grinding, drilling, reaming and countersinking. In order to better explain the present invention and facilitate understanding, the following is combined with the attached Figures 18 to 20 , the present invention is described in detail through specific implementation method three.

[0135] Implementation method 3: Partial separation continuous high-speed ultrasonic vibration drilling / reaming / countersinking processing method, such as Fig.18 , 19 20 is a drilling / reaming / countersinking principle based on the method, which includes the following steps:

[0136] Step S1: Fix the workpiece 1 on the workbench of the machining center.

[0137] Step S2: Setting cutting parameters. Specifically, as an example, a coated carbide tool is used to drill GH4169, with a cutting speed of 100 m / min and a feed per tooth of 0.04 mm / tooth.

[0138] Step S3: Select ultrasonic drilling / reaming / countersinking toolholder. Fig.18 When the vibration direction of the drill bit 5 is transverse ultrasonic vibration, the vibration direction of the drill bit 5 is perpendicular to the cutting speed direction and parallel to the feed direction of the drill bit 5; when the vibration direction of the drill bit 5 is elliptical ultrasonic vibration, the elliptical ultrasonic vibration of the drill bit 5 has a vibration component perpendicular to the cutting speed direction of the cutting edge of the drill bit 5. Fig.19 When the vibration direction of the reamer 6 is transverse ultrasonic vibration, the vibration direction of the reamer 6 is perpendicular to the cutting speed direction and parallel to the feeding direction of the reamer 6; when the vibration direction of the reamer 6 is elliptical ultrasonic vibration, the elliptical ultrasonic vibration of the reamer 6 has a vibration component perpendicular to the cutting speed direction of the cutting edge of the reamer 6. Fig. 20 When the vibration direction of the countersink drill 7 is transverse ultrasonic vibration, the vibration direction of the countersink drill 7 is perpendicular to the cutting speed direction and parallel to the feed direction of the countersink drill 7; when the vibration direction of the countersink drill 7 is elliptical ultrasonic vibration, the elliptical ultrasonic vibration of the countersink drill 7 has a vibration component perpendicular to the cutting speed direction of the cutting edge of the countersink drill 7. For the example in step S2, the transverse ultrasonic vibration drill can be selected.

[0139] Step S4: Setting vibration parameters. According to the cutting parameters, the vibration parameters can be set as follows: the vibration direction is lateral, the vibration frequency is 20 kHz, and the single-side vibration amplitude is 6 um.

[0140] Step S5: Setting cooling parameters. For the example in step S2, a water-soluble emulsion with a concentration of 8% is selected and sprayed onto the rake face, the flank face, or both the rake face and the flank face at a pressure of 50 bar.

[0141] Step S6: Turn on the high-pressure cooling system, turn on the ultrasonic vibration system, and turn on the machining center to complete the local separation continuous high-speed ultrasonic vibration drilling / reaming / countersinking.

[0142] Based on the above-mentioned embodiments 1 to 4, it can be known that the local separation continuous high-speed ultrasonic vibration processing method proposed in this technical solution uses an ultrasonic power supply to excite the tool to generate transverse ultrasonic vibration or ultrasonic vibration with a transverse component. The combination of different vibration forms and cutting processing technology and part type shape can realize the processing of parts of different shapes by various cutting processing technologies. It completely breaks through the limitations of critical cutting parameters (cutting speed, feed rate, cutting depth), and greatly improves the material removal rate compared with existing ultrasonic processing technology and ordinary processing technology. At the same time, it has many advantages such as reduced cutting force and cutting heat, extended tool life, reduced processing costs, optimized surface quality and improved processing quality.

[0143] The above description is only a preferred embodiment of the present application and is not intended to limit the present application. Any modifications, equivalent substitutions or improvements made within the spirit and principles of the present application should be included in the protection scope of the present application.

Claims

1. A local separation continuous high-speed ultrasonic vibration processing method, characterized in that: include: Step 1: Install the ultrasonic vibration tool holder on the corresponding machine tool, so that the cutting edge of the cutting tool on the ultrasonic vibration tool holder generates lateral vibration or lateral component vibration along the feed direction in the tool base surface; Step 2: According to the processing amount, reasonably match the ultrasonic vibration parameters and the cooling parameters, so that when the cutting tool is continuously cutting on the tool tip trajectory, the conditions of local separation of the wave ridges are met between the front tool face of the tool and the bottom surface of the chip, and / or between the back tool face of the tool and the processing surface; wherein the processing amount is the three parameters of the cutting speed, feed rate and cutting depth of the cutting tool, the ultrasonic vibration parameters include the three parameters of amplitude, frequency and vibration form, and the cooling parameters include the three parameters of coolant type, coolant pressure and coolant application position; Step 3: Turn on the cooling system, ultrasonic vibration system and machine tool to perform a continuous high-speed ultrasonic vibration processing process for partial separation of the workpiece by the cutting tool.

2. The local separation continuous high-speed ultrasonic vibration processing method according to claim 1 is characterized in that: The machine tool in step 1 is at least one of a lathe, a milling machine, a drilling machine, a grinder and a machining center.

3. The local separation continuous high-speed ultrasonic vibration processing method according to claim 1, characterized in that: The cutting tool in step one includes at least one of a turning tool, a milling cutter, a drill bit, a grinding head, a reamer and a countersink.

4. The local separation continuous high-speed ultrasonic vibration machining method according to claim 3, characterized in that: The ultrasonic vibration tool holder in step one includes at least one of a turning tool holder, a milling cutter holder, a drill bit holder, a grinding head holder, a reamer holder and a countersink holder.

5. The local separation continuous high-speed ultrasonic vibration machining method according to any one of claims 1 to 4, characterized in that: The material of the cutting tool in step 1 is at least one of cemented carbide, ceramic, cermet, cubic boron nitride and diamond.

6. The local separation continuous high-speed ultrasonic vibration machining method according to any one of claims 1 to 4, characterized in that: When the partially separated continuous high-speed ultrasonic vibration processing method is combined with a turning method, it includes two methods: partially separated continuous high-speed transverse ultrasonic vibration turning and partially separated continuous high-speed elliptical ultrasonic vibration turning; when the partially separated continuous high-speed ultrasonic vibration processing method is combined with a milling method, it includes two methods: partially separated continuous high-speed elliptical ultrasonic vibration milling and partially separated continuous high-speed transverse ultrasonic vibration milling; when the partially separated continuous high-speed ultrasonic vibration processing method is combined with a grinding method, it includes two methods: partially separated continuous high-speed elliptical ultrasonic vibration grinding and locally separated continuous high-speed transverse ultrasonic vibration grinding; when the partially separated continuous high-speed ultrasonic vibration processing method is combined with a drilling method, it includes two methods: partially separated continuous high-speed elliptical ultrasonic vibration drilling and locally separated continuous high-speed transverse ultrasonic vibration drilling; when the partially separated continuous high-speed ultrasonic vibration processing method is combined with a reaming method, it includes two methods: partially separated continuous high-speed transverse ultrasonic vibration reaming and locally separated continuous high-speed elliptical ultrasonic vibration reaming; when the partially separated continuous high-speed ultrasonic vibration processing method is combined with a countersinking method, it includes two methods: locally separated continuous high-speed transverse ultrasonic vibration countersinking and locally separated continuous high-speed elliptical ultrasonic vibration countersinking.

7. The local separation continuous high-speed ultrasonic vibration processing method according to claim 6, characterized in that: When the local separation continuous high-speed ultrasonic vibration machining method is used for external cylindrical turning, f>2A, and the vibration direction of the tool is parallel to the feed direction, the vibration equation of the tool is: z = Asin(2πFt); Among them, F is the ultrasonic vibration frequency, A is the actual ultrasonic vibration amplitude during turning, f is the feed rate, t is the time, θ is the angle corresponding to the arc between point D on the cutting edge and the tool tip, at point D on the cutting edge: The nominal ridge heights of the chip bottom and the machined surface are: h c =2Asinθ; h s =2Asinθ; The heights of the corrugations squeezed out of the chip bottom and the machined surface are: h cE =2Bsinθ; h sE =2Csinθ; The residual wave ridge heights of the chip bottom and the machined surface are: h cR =2(A-B)sinθ; h sR =2(A-C)sinθ; Among them, B and C are the amplitudes actually removed after extrusion and rebound at the nominal amplitude A; The maximum separation gaps between the rake face and the chip bottom and between the flank face and the machined surface are: C c =h cE ; C s =h sE ; The nominal wave period lengths of the chip bottom and the machined surface are: Among them, v ch is the chip flow velocity, v is the cutting speed; The duty ratios of the separation phases between the rake face and the chip bottom and between the flank face and the machined surface are:

8. The local separation continuous high-speed ultrasonic vibration machining method according to claim 7, characterized in that: The conditions for local separation of the wave ridges between the tool rake face and the chip bottom surface are: 0<C c <G; The conditions for local separation of corrugations between the tool flank and the machined surface are: 0<C s <G; Among them, G is the upper limit of the height of the squeezed ridges.

9. The local separation continuous high-speed ultrasonic vibration machining method according to any one of claims 1 to 4, characterized in that: The direction of the lateral vibration or the lateral component vibration in step one is perpendicular to the cutting speed of the cutting tool, and the vibration form of the lateral vibration or the lateral component vibration is one-dimensional vibration, two-dimensional vibration, three-dimensional vibration or elliptical vibration.

10. The local separation continuous high-speed ultrasonic vibration machining method according to any one of claims 1 to 4, characterized in that: The coolant type includes at least one of oil-based cutting fluid, oil-based cutting mist, water-based cutting fluid, water-based cutting mist, liquid nitrogen and air; in step three, after the cooling system is turned on, the coolant can be sprayed into the cutting area from the front face of the tool, the back face of the tool, or from both the front face and the back face of the tool.

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