CN105921769B - A kind of difficult processing axial UVC processing method of aeronautical material high speed - Google Patents

Abstract

The invention discloses a high-speed axial ultrasonic vibration cutting processing method for difficult-to-machine aviation materials, which is a new mechanical processing method for cutting and processing difficult-to-machine aviation materials by utilizing the axial ultrasonic vibration cutting technology. The processing method adopts the axial ultrasonic vibration cutting device, supplemented by the process principle of intermittent cutting, which can greatly increase the cutting speed, shorten the processing time, improve the processing efficiency, prolong the tool life and reduce the processing cost. Compared with traditional vibration cutting, it greatly expands the application range of ultrasonic vibration machining technology. By adopting the processing method of the present invention, high-speed, high-efficiency and high-quality processing can be realized for difficult-to-process aviation materials.

Description

A High-Speed Axial Ultrasonic Vibration Machining Method for Difficult-to-Machine Aeronautical Materials

technical field

The present invention designs a method for high-speed machining of difficult-to-machine aerospace materials using ultrasonic vibration cutting, more particularly, refers to a method of using axial ultrasonic vibration technology to process difficult-to-machine aerospace materials, especially titanium alloys and superalloys Intermittent, efficient, high-quality machining methods.

Background technique

The difficult-to-machine material refers to a material that is difficult to machine, that is, a material that has poor machinability. Materials whose machinability grade codes are above grade 5 are difficult-to-machine materials. "Modern Processing Technology (Second Edition)", p. 316, edited by Zuo Dunwen, Beijing University of Aeronautics and Astronautics Press, August 2009.

According to the movement mode of the tool (blade) and the workpiece and the shape of the tool, the cutting process can be divided into: turning, milling, planing, drilling, boring, broaching, reaming, tapping, gear shaping, gear hobbing, etc. All of the above processes have their own tools, so there are many types of tools for cutting.

Due to the special processing mechanism of traditional vibration cutting, although it can reduce the cutting force, reduce the cutting temperature, improve the ultimate cutting ability and processing quality, but due to the limitation of the limit speed, the cutting line speed is very small (generally 4 ~ 6m/min), Especially for rotating parts such as large-diameter long shafts or deep holes made of difficult-to-machine materials, the efficiency is very low, which is greatly limited in actual cutting applications.

Contents of the invention

In order to improve the processing quality and processing efficiency of difficult-to-machine aerospace materials, the purpose of this invention is to propose a high-efficiency machining method suitable for large-diameter shafts or deep holes of difficult-to-machine aerospace materials such as titanium alloys or superalloys, that is, high-speed axial Ultrasonic vibration cutting method. This processing method uses the combination of turning and boring to realize the processing of large-diameter long shafts or deep holes of titanium alloy, which is difficult to machine, which can greatly shorten the processing time and improve the processing quality of difficult-to-machine aerospace materials. The processing method of the present invention can particularly realize high-speed, high-efficiency, and high-quality processing of large-diameter long shafts or holes.

The invention proposes a high-speed axial ultrasonic vibration cutting processing method for difficult-to-machine aviation materials. The processing method is to install an axial ultrasonic vibration cutting device on an existing lathe, and use the high-speed axial The tool tip generated by the ultrasonic vibration cutting tool (2) vibrates along the sinusoidal trajectory, combined with the geometric characteristics of the large-diameter long axis or deep hole designed by the lathe control end, it is realized by clamping and positioning technology; the specific processing method is divided into For turning large diameter long shafts and for boring deep holes at the ends of large diameter long shafts.

Turning large diameter long shaft:

Conditions for first-cut outer circle turning: linear speed 250-300 m/min, feed rate 0.005-0.015 mm/rev, cutting depth 0.01-0.03 mm, vibration frequency about 20KHz, voltage 50 volts, current 1 ampere, bilateral amplitude 20 Micron;

Cylindrical turning process: Execute the tool change program, and use the axial ultrasonic vibration cutting device (8) to prepare for cylindrical turning; after the jacking is tightened, the round runout of the right end of the workpiece is required to be no more than 0.005mm;

Move the support point and perform the second round of outer circle turning in sequence until the outer circle turning is completed;

Boring a deep hole at the end of a long shaft with a large diameter:

Deep hole boring conditions for the first cut: line speed 150-250 m/min, feed rate 0.005-0.015 mm/rev, cutting depth 0.005-0.02 mm;

Deep hole boring process: Clamp the workpiece that has been processed to the required margin. The clamping requires that the runout at 10mm from the chuck position is not greater than 0.002mm, and the circular runout at the right end surface is not greater than 0.01mm; Pre-generated tool paths command boring until the specified dimensions of the part are machined.

In the high-speed axial ultrasonic vibration cutting processing method for difficult-to-machine aviation materials proposed by the present invention, the pre-adjusted vibration turning device is turned on, and the tool is applied to the tool in the axial direction of the workpiece. The phase of the vibration drive source makes the vibration of the tool a sinusoidal track, so that the tool is in an axial vibration state during the subsequent cutting process.

The present invention has the advantages of the high-speed axial ultrasonic vibration cutting method for large-diameter long shafts or holes:

① Through the cutting principle of high-speed intermittent vibration, the speed limit of vibration cutting has been broken through. For titanium alloy turning, it can reach a maximum of 300m/min, which is 2 to 3 times higher than ordinary turning; for superalloys, it can also be increased by 2 to 3 times. Double the turning speed, so as to achieve the purpose of efficient machining. In the traditional conventional turning process, the cutting speed range of titanium alloy is about 80-150m/min, while the cutting speed range of superalloy is about 70-80m/min. Therefore, the cutting efficiency is greatly limited.

②During the high-speed axial ultrasonic vibration cutting process, large amplitude (10 microns on one side), micro-cutting depth a _p (0.008-0.010 mm), ultrasonic frequency vibration (about 20 kHz), and phase control are used for processing, reducing Improve the surface roughness of the workpiece and improve the dimensional accuracy of the workpiece.

③In the high-speed cutting state, the cutting tool, the workpiece and the chips will be separated periodically or locally, the cutting force will decrease (50% to 70% of ordinary cutting), and the cutting temperature will decrease (decrease by 1 order of magnitude), effectively suppressing the The deterioration of workpiece quality due to stress deformation and thermal deformation.

④In the processing method of the present invention, a matching ultrasonic vibration cutting device is installed on the CNC lathe, which improves the processing capability of the CNC lathe and reduces the processing cost of difficult-to-machine aerospace materials.

Description of drawings

Fig. 1 is an external structure diagram of an axial ultrasonic vibration cutting device designed in the present invention.

Fig. 1A is another view of the external structure of the axial ultrasonic vibration cutting device designed in the present invention.

Fig. 1B is a cross-sectional structure diagram of the axial ultrasonic vibration cutting device designed in the present invention.

Fig. 1C is an exploded view of the axial ultrasonic vibration cutting device designed in the present invention.

Figure 2 is an isometric schematic diagram of the workpiece drawn by 3D software.

FIG. 2A is a schematic diagram of dimension setting when using 3D software to draw a workpiece.

Fig. 3 is a schematic diagram of the cylindrical turning process of the present invention.

Fig. 4 is a schematic diagram of the deep hole boring process of the present invention.

Fig. 5A is a schematic diagram of the vibration form of the present invention.

Fig. 5B is a schematic diagram of the motion trajectory of the tool tip in the present invention.

Fig. 6 is a diagram of the microfabrication process of the present invention.

1. Knife seat 2. High-speed axial ultrasonic vibration cutting tool 201. Compression screw 202. Rear end cover 203. Incentive source 204. Insulation sleeve 205. Front end cover and horn 3. Front cover of tool holder 4. Knife seat back cover 5. Blade 6. Aviation plug 7. Machine tool three-jaw chuck

detailed description

The present invention will be further described in detail below by taking the processing of TC4 titanium alloy large-diameter long shaft or deep hole as an example in conjunction with the accompanying drawings.

Referring to Fig. 1, Fig. 1A, Fig. 1B, shown in Fig. 1C, the present invention is to install the matched high-speed axial ultrasonic vibration cutting device on the CNC machining center, and then through the computer and the three-dimensional drawing software installed in the computer And control software to perform cutting control processing on the parts (or workpieces) that need to be processed.

The present invention is a method for efficient and high-quality processing of difficult-to-machine aviation materials with large diameters and long shafts or holes based on axial ultrasonic vibration. The processing method includes the steps of pre-processing preparation and part processing. For turning large diameter long shafts and for boring deep holes at the ends of large diameter long shafts.

Workpiece preparation

Step 1-1: Digitize the part configuration, use 3D drawing software (such as CATIA/Autocad/Proe, etc.) to carry out the 3D configuration of the required processing parts (TC4 titanium alloy large diameter long axis or hole); the configuration diagram is shown in the figure 2 shown.

Referring to shown in Fig. 2A, in the present invention, adopt the ratio dimension of 1:1 to carry out part configuration in three-dimensional drawing software according to required processing part size, and this size information is input to numerical control machining center; In the present invention, The part size includes the total length L of the workpiece, the outer diameter D, the length of the hole h, and the diameter of the deep hole d.

Step 1-2: Adjust the CNC machine tool. After the CNC machine tool is adjusted, the rotation accuracy of the spindle is required to be within 0.02 mm, the coaxiality between the center line of the tail tip and the spindle rotation center of the CNC machining center is within 0.05 mm, and the pressure of the tail tip is within 0.5 Bar (bar ).

Step 1-3: Clamp the high-speed axial ultrasonic vibration cutting device on the adjusted CNC machine tool, and fine-tune the turning blade 5 to be level with the center of the CNC machine tool.

Step 1-4: Adjust the vibration parameters of the high-speed axial ultrasonic vibration cutting tool 2 during processing in the high-speed axial ultrasonic vibration cutting device: the vibration frequency is about 20 kHz, and the unilateral amplitude of the blade 5 is 10 μm.

Step 1-5: The blank should be rough-turned and peeled before processing, and the straight axis of the finish-turn should be aligned. In order to prevent excessive residual stress on the workpiece during the rough-turning process, the cut-in amount of the rough-turning should be controlled within 0.5mm. After rough turning, the circular runout of the workpiece to the center hole is required to be no more than 0.03mm. Thereafter, hole drilling was performed until the machining allowance was 0.1 mm.

Referring to Fig. 1, Fig. 1A, Fig. 1B, and Fig. 1C, the axial ultrasonic vibration cutting device designed by the present invention includes a tool seat 1, a high-speed axial ultrasonic vibration cutting tool 2, a tool seat front cover 3, a knife Seat rear cover 4, blade 5 and aviation plug 6; High-speed axial ultrasonic vibration cutting tool 2 is installed in the tool seat 1, supported and fixed by screws, and the front end cover and horn 205 of high-speed axial ultrasonic vibration cutting tool 2 are The round hole in the middle of the tool holder front cover 3 protrudes, and the excitation source 203 in the high-speed axial ultrasonic vibration cutting tool 2 is connected with one end of the aviation plug 6 with a wire; the tool holder front cover 3 is installed on the front end of the tool holder 1, and the tool holder rear cover 4 is installed on the rear end of the tool holder 1; the aviation plug 6 is installed on the center hole of the rear cover 4 of the tool holder, and the other end is connected to the external ultrasonic vibration excitation power supply to receive the externally generated vibration excitation signal and transmit it to the high-speed axial ultrasonic Vibrating cutting tool2.

The tool seat 1 is used to fix the high-speed axial ultrasonic vibration cutting tool 2 of the high-speed axial ultrasonic vibration cutting tool. One side of the tool holder has a protruding clamping structure for clamping by the clamping device of the machine tool.

The high-speed axial ultrasonic vibration cutting tool 2 is used to generate axial ultrasonic vibration required for processing.

The high-speed axial ultrasonic vibration cutting tool 2 includes a compression screw 201 , a rear end cover 202 , an excitation source 203 , an insulating sleeve 204 , a front end cover and a horn 205 .

After the threaded end of the compression screw 201 passes through the rear end cover 202, the inner hole of the excitation source 203 and the insulating sleeve 204 in sequence, it is threadedly connected to the threaded inner hole of the front end cover and the horn 205, thereby realizing the rear end cover 202, the excitation source The source 203 and the front cover and horn 205 are fastened together.

The excitation source 203 is used to generate the ultrasonic vibration required for processing.

The insulating sleeve 204 is located between the inner hole of the excitation source 203 and the compression screw 201 .

The front end cover and the horn 205 are integrally processed to form a stepped shaft structure with rounded transitions. One end of the front cover and the horn 205 is provided with a knife groove for installing the blade 5, and the other end of the front cover and the horn 205 is a flat surface. , and the center of the flat surface is provided with a threaded hole for the compression screw 201 to be tightened.

In the present invention, selecting one excitation source 203 can realize vibration in one direction. In FIG. 3, the intense source 203 generates a bending vibration, and in FIG. 4, the excitation source 203 generates longitudinal vibration along the intense source.

In the present invention, when boring, the position of the blade 5 is lateral as shown in FIG. 1 . During turning, the position of the blade 5 as shown in FIG. Different vibration forms, the vibration of the tool tip is generated along the axial direction of the workpiece. All of them can break through the speed limit of conventional vibratory cutting. Therefore, the processing speed can be increased.

Example 1

Turning large diameter long shaft

The present invention adopts the turning process to carry out the method of high-efficiency and high-quality processing on the basis of axial ultrasonic vibration on the large-diameter long shaft. The difficult-to-machine aviation material is selected from TC4 titanium alloy. The processing method includes the steps of pre-processing preparation and part processing:

(1) Preparation before processing

Step 1-1: Digitize the part configuration, use 3D drawing software (such as CATIA/Autocad/Proe, etc.) to carry out the 3D configuration of the large-diameter and long-axis parts to be processed; the configuration diagram is shown in Figure 2.

Referring to shown in Fig. 2A, in the present invention, adopt the ratio dimension of 1:1 to carry out part configuration in three-dimensional drawing software according to required processing part size, and this size information is input to numerical control machining center; In the present invention, The part size includes the total length L of the workpiece, the outer diameter D, the length of the hole h, and the diameter of the deep hole d.

Step 1-2: Adjust the CNC machine tool. After the CNC machine tool is adjusted, the rotation accuracy of the spindle is required to be within 0.02 mm, the coaxiality between the center line of the tail tip and the spindle rotation center of the CNC machining center is within 0.05 mm, and the pressure of the tail tip is within 0.5 Bar (bar ).

Step 1-3: Clamp the high-speed axial ultrasonic vibration cutting device on the adjusted CNC machine tool, and fine-tune the turning blade 5 to be level with the center of the CNC machine tool.

Step 1-4: Adjust the vibration parameters of the high-speed axial ultrasonic vibration cutting tool 2 in the high-speed axial ultrasonic vibration cutting device during processing: the vibration frequency is about 20 kHz, and the unilateral amplitude of the blade 5 is 10 μm.

Step 1-5: The blank should be rough-turned and peeled before processing, and the straight axis of the finish-turn should be aligned. In order to prevent excessive residual stress on the workpiece during the rough-turning process, the cut-in amount of the rough-turning should be controlled within 0.5mm. After rough turning, the circular runout of the workpiece to the center hole is required to be no more than 0.03mm. Thereafter, hole drilling was performed until the machining allowance was 0.1 mm.

(2) Processing of large diameter and long axis parts

Conditions for first-cut outer circle turning: linear speed 250-300 m/min, feed rate 0.005-0.015 mm/rev, cutting depth 0.01-0.03 mm, vibration frequency about 20KHz, voltage 50 volts, current 1 ampere, bilateral amplitude 20 Micron;

As shown in FIG. 3 , the process of cylindrical turning: the tool change program is executed, and the high-speed axial ultrasonic vibration cutting tool 2 is used to prepare for cylindrical turning. After the top is tightened, the round runout of the right end of the workpiece is required to be no more than 0.005mm.

Referring to Fig. 5A and Fig. 5B, the pre-adjusted vibration turning device is turned on, and a large-amplitude vibration of ultrasonic frequency is applied to the blade 5 in the axial direction. The large-amplitude vibration of ultrasonic frequency is formed by high-speed axial ultrasonic vibration cutting. Provided by tool 2, its unilateral amplitude is 10 μm; by adjusting the phase of the vibration drive source, the vibration of the tool becomes a sinusoidal trajectory vibration, so that the tool is in an axial vibration state during the subsequent cutting process, and starts to follow the pre-generated tool Turning is carried out with the path command until the specified size of the part is machined. In the process of high-speed intermittent axial ultrasonic vibration cutting, large amplitude (10 microns on one side), micro cutting depth a _p (0.01-0.03 mm), ultrasonic frequency vibration (20 kHz) and phase control are used for processing, reducing Improve the surface roughness of the workpiece and improve the dimensional accuracy of the workpiece.

The cutting microscopic process is shown in Figure 6, which is the cross-sectional view of the tool shown in Figure 5B in the feed plane A-A', and the high-speed ultrasonic vibration cutting process in one vibration cycle (from point a to point e) can be divided into three stages : point a→point b is the cut-in stage, point b→point c is the cut-out stage, point c→e is the air-cut stage. During the high-speed ultrasonic vibration cutting process, the tool vibrates at the ultrasonic frequency with the vibration balance line as the balance position.

In each cutting cycle, the blade 5 cuts into the workpiece from point a, and the chip width l _r increases gradually. When reaching point b, the chip width of the entire cutting process is the largest, and point b is the lowest point on the workpiece processing surface. The dynamic rake angle β ₁ of the blade in the cutting stage shows a process from small to large and then small, and it is greater than the theoretical rake angle β ₂ of the blade. On the contrary, the dynamic relief angle α ₁ is smaller than the theoretical blade angle Relief angle α ₂ ; when the insert 5 is in the cutting-out stage of the cutting cycle, the chip width gradually decreases from point b, and the influence of the entire cutting cycle on the machined surface ends at point c, and the blade in the cutting-out stage The dynamic rake angle β ₁ is smaller than the theoretical rake angle β ₂ of the blade, and the dynamic relief angle α ₁ is also the opposite, which is greater than the theoretical relief angle α ₂ of the blade. At the same time, in the cutting-out stage from point b to point c, the insert pulls back, the cutting feed width f _r decreases, and the speed of the insert in the direction of the chip width l _r gradually increases, and the direction of friction between the chip and the rake face occurs Reverse, which is beneficial to the reduction of the resistance of the knife; c point → e point is the air cutting stage of the whole cutting cycle. From point c, the blade is separated from the workpiece and chips, realizing intermittent cutting. The machined surface does not touch at all, the cutting force is reduced to 0, and the blade does not have any influence on the surface morphology of the workpiece; when the blade reaches point e, a cutting cycle process ends, so point a → point e is a complete cutting cycle, after that The insert makes its next contact with the workpiece, starting the next cutting cycle. This is the intermittent cutting process in which the blade, workpiece, and chips are periodically separated.

In FIG. ₆ , the dynamic rake angle β1 refers to the angle between the rake face of the insert 5 and the tangent line of the tool nose arc. _The dynamic relief angle α1 refers to the angle between the flank of the insert 5 and the tangent line of the arc of the tool nose.

The feed rate f _r refers to the distance between the outer contour line of the workpiece and the vibration balance line.

The chip width _lr refers to the distance between the rake face of the insert 5 and the surface to be processed of the workpiece.

In the present invention, the supporting point is moved, and then the second tool turning, the third tool turning, ... until the outer circle turning of the long axis with large diameter is completed.

Adopt the cylindrical turning processing method of the present invention to pay attention to the following aspects in the process of processing:

(1) The feed rate per revolution is not greater than 0.01mm of the unilateral amplitude to prevent intermittent cutting from changing to continuous cutting due to excessive feed rate.

(2) Real-time monitoring of the wear state of the blade 5, once the wear state of the blade 5 is found to occur, replace the blade 5;

(3) The spindle speed (denoted as n) should meet the requirements of the cutting tools and cutting conditions. (where A is the amplitude, D is the outer diameter of the workpiece, ω is the angular frequency of ultrasonic vibration, α ₂ is the theoretical clearance angle of the blade, π=3.14) Under the condition, it is reasonable to choose to avoid tool wear.

(4) The top part of the tail should be lubricated with sufficient lubricating oil, and there should be no interference from debris such as chips;

(5) During the cutting process, loosen the tail tip intermittently to release the stress, so as to ensure that there is no long-term residual stress in the workpiece.

Example 2

boring deep hole

The present invention uses a boring process to efficiently and high-quality process the deep hole at the end of the long axis with a large diameter. The difficult-to-process aviation material is selected from TC4 titanium alloy. The processing method includes the steps of pre-processing preparation and part processing:

(1) Preparation before processing

Step 1-1: Digitize the part configuration, use 3D drawing software (such as CATIA/Autocad/Proe, etc.) to carry out the 3D configuration of the large-diameter and long-axis parts to be processed; the configuration diagram is shown in Figure 2.

Referring to shown in Fig. 2A, in the present invention, adopt the ratio dimension of 1:1 to carry out part configuration in three-dimensional drawing software according to required processing part size, and this size information is input to numerical control machining center; In the present invention, The part size includes the total length L of the workpiece, the outer diameter D, the length of the hole h, and the diameter of the deep hole d.

Step 1-2: Adjust the CNC machine tool, requiring the rotation accuracy of the spindle to be within 0.02 mm after the CNC machine tool is adjusted.

Steps 1-3: Clamp the high-speed axial ultrasonic vibration cutting tool 2 on the adjusted CNC machine tool, and fine-tune the turning blade 5 to be level with the center of the CNC machine tool.

Steps 1-4: Adjust the vibration parameters of the high-speed axial ultrasonic vibration cutting tool 2 during processing: the vibration frequency is about 20 kHz, and the unilateral amplitude of the blade 5 is 8 μm.

Step 1-5: The blank should be rough-turned and peeled before processing, and the straight axis of the finish-turn should be aligned. In order to prevent excessive residual stress on the workpiece during the rough-turning process, the cut-in amount of the rough-turning should be controlled within 0.5mm. After rough turning, the circular runout of the workpiece to the center hole is required to be no more than 0.03mm. Thereafter, hole drilling was performed until the machining allowance was 0.1 mm.

(2) Processing of deep hole parts

Deep hole boring conditions for the first cut: line speed 150-250 m/min, feed rate 0.005-0.015 mm/rev, cutting depth 0.005-0.02 mm;

As shown in Figure 4, the inner hole boring process: clamping the workpiece that has been machined to the required margin, the clamping requires that the runout at 10mm from the position of the three-jaw chuck of the machine tool should not be greater than 0.002mm, and the circular runout at the right end surface should not exceed 0.002mm. If it is greater than 0.01mm, turn on the vibration device and start boring according to the pre-generated tool path instructions until the specified size of the part is processed.

Referring to Fig. 5A and Fig. 5B, the pre-adjusted vibration turning device is turned on, and a large-amplitude vibration of ultrasonic frequency is applied to the blade 5 in the axial direction. The large-amplitude vibration of ultrasonic frequency is formed by high-speed axial ultrasonic vibration cutting. Provided by tool 2, its unilateral amplitude is 8 μm; by adjusting the phase of the vibration drive source, the vibration of the tool becomes a sinusoidal trajectory vibration, so that the tool is in an axial vibration state during the subsequent cutting process, and starts to follow the pre-generated tool Turning is carried out with the path command until the specified size of the part is machined. During the high-speed intermittent axial ultrasonic vibration cutting process, large amplitude (8 microns on one side), micro-cutting depth a _p (0.005-0.02 mm), ultrasonic frequency vibration (20 kHz) and phase control are used for processing, reducing Improve the surface roughness of the workpiece and improve the dimensional accuracy of the workpiece.

The cutting microscopic process is shown in Figure 6, which is the cross-sectional view of the tool shown in Figure 5B in the feed plane A-A', and the high-speed ultrasonic vibration cutting process in one vibration cycle (from point a to point e) can be divided into three stages : point a→point b is the cut-in stage, point b→point c is the cut-out stage, point c→e is the air-cut stage. During the high-speed ultrasonic vibration cutting process, the tool vibrates at the ultrasonic frequency with the vibration balance line as the balance position.

In each cutting cycle, the blade 5 cuts into the workpiece from point a, and the chip width l _r increases gradually. When reaching point b, the chip width of the entire cutting process is the largest, and point b is the lowest point on the workpiece processing surface. The dynamic rake angle β ₁ of the blade in the cutting stage shows a process from small to large and then small, and it is greater than the theoretical rake angle β ₂ of the blade. On the contrary, the dynamic relief angle α ₁ is smaller than the theoretical blade angle Relief angle α ₂ ; when the insert 5 is in the cutting-out stage of the cutting cycle, the chip width gradually decreases from point b, and the influence of the entire cutting cycle on the machined surface ends at point c, and the blade in the cutting-out stage The dynamic rake angle β ₁ is smaller than the theoretical rake angle β ₂ of the blade, and the dynamic relief angle α ₁ is also the opposite, which is greater than the theoretical relief angle α ₂ of the blade. At the same time, in the cutting-out stage from point b→c, the insert pulls back, the cutting feed width f decreases, and the speed of the insert in the direction of chip width _lr gradually increases, and the direction of the friction force generated by the chip and the rake face reverses. This is beneficial to the reduction of the knife resistance; c point → e point is the empty cutting stage of the whole cutting cycle, starting from c point, the blade is separated from the workpiece and chips, realizing intermittent cutting, and the blade and workpiece have been processed in the whole stage The surface is completely non-contact, the cutting force is reduced to 0, and the blade has no effect on the surface morphology of the workpiece; when the blade reaches point e, a cutting cycle process ends, so point a → point e is a complete cutting cycle, after which the blade Begins contact with the workpiece again to begin the next cutting cycle. This is the intermittent cutting process in which the blade, workpiece, and chips are periodically separated.

In FIG. ₆ , the dynamic rake angle β1 refers to the angle between the rake face of the insert 5 and the tangent line of the tool nose arc. _The dynamic relief angle α1 refers to the angle between the flank of the insert 5 and the tangent line of the arc of the tool nose.

The feed rate f _r refers to the distance between the outer contour line of the workpiece and the vibration balance line.

The chip width _lr refers to the distance between the rake face of the insert 5 and the surface to be processed of the workpiece.

In the present invention, then the second cutting tool turning, the third tool turning, ... until the boring of the deep hole is completed.

Adopt the boring processing method of the present invention to pay attention to the following aspects in the process of processing:

(1) The feed rate per revolution is not greater than the unilateral amplitude of 0.008 mm to prevent intermittent cutting from changing to continuous cutting due to excessive feed rate.

(2) Real-time monitoring of the wear state of the blade 5, once the wear state of the blade 5 is found to occur, replace the blade 5;

(3) Spindle speed (n) should meet the requirements of cutting tools and cutting conditions (where A is the amplitude, D is the outer diameter of the workpiece, ω is the angular frequency of ultrasonic vibration, and _α2 is the theoretical back angle of the blade) Under the condition, it is reasonable to choose to avoid the wear of the blade.

(4) Observe the vibration of the workpiece in real time, reasonably control the cutting speed, and prevent chatter, so as not to cause deep hole scratches and surface quality deterioration.

A kind of high-speed intermittent ultrasonic vibration turning (boring) cutting processing method of difficult-to-machine aviation materials proposed by the present invention is to use the axial ultrasonic vibration cutting technology to cut and process difficult-to-machine aviation material parts such as large-diameter long shafts or holes A new machining method. This processing method adopts the axial ultrasonic vibration cutting device, supplemented by the process principle of intermittent cutting, which greatly improves the cutting speed, shortens the processing time, improves the processing efficiency, prolongs the tool life, reduces the processing cost, optimizes the surface quality, Suppress chatter and improve processing quality. Adopting the processing method of the present invention can realize high-speed, high-efficiency, and high-quality processing of difficult-to-process aviation material workpieces such as titanium alloys and high-temperature alloys. Due to its unique motion trajectory and cutting principle, high-speed axial ultrasonic vibration cutting can greatly reduce cutting resistance (about 50%-70% of ordinary cutting resistance), reduce cutting temperature, improve limit cutting ability, and reduce vibration. It has a series of notable features such as insensitivity and excellent surface quality. At the same time, it breaks through the cutting limit speed of difficult-to-machine materials (greater than 100 m/min), and the cutting efficiency is effectively improved. It can be seen that high-speed axial ultrasonic vibration cutting is an effective and efficient method for processing difficult-to-machine aerospace materials.

Claims (3)

1. A kind of 1. difficult processing axial UVC processing method of aeronautical material high speed, it is characterised in that：The processing method is Produced by installing the axial ultrasonic vibration cutting device of high speed on existing lathe, and by the axial ultrasonic vibration cutting device of high speed Point of a knife vibrated along sinusoidal trajectory, the major diameter major axis that is designed with reference to Lathe control end or the difficult processing aeronautical material of deep hole it is several What feature, realized using clamping and positioning process；Specific processing mode is divided into turning large-diameter major axis, and boring major diameter length The deep hole of shaft end；

   Turning large-diameter major axis：

   First knife cylindrical turning condition：250~300 ms/min of linear velocity, 0.005~0.015 millimeter of the amount of feeding/turn, cutting depth 0.01~0.03 millimeter, vibration frequency about 20KHz, 50 volts of voltage, 1 ampere of electric current, bilateral 20 microns of amplitude；

   Cylindrical turning process：Tool changing program is performed, and cylindrical turning is ready for using axial ultrasonic vibration cutting device (8)；Top It is next to require that the circle bounce of workpiece right-hand member is not more than 0.005mm；

   The mobile strong point, sequentially carries out the second knife cylindrical turning, until completing cylindrical turning；

   The deep hole of boring major diameter major axis end

   First knife deep hole boring condition：150~250 ms/min of linear velocity, 0.005~0.015 millimeter of the amount of feeding/turn, cutting depth 0.005~0.02 millimeter；

   Deep hole boring process：The machined workpiece to required surplus of clamping, clamp require apart from chuck position 10mm bounce not More than 0.002mm, the circle bounce at right side is not more than 0.01mm；Vibrating device is opened, is started according to the cutter previously generated Path instructions carry out boring, are directly processed to the given size of part.
2. 2. a kind of difficult processing axial UVC processing method of aeronautical material high speed according to claim 1, it is special Sign is：The vibration turning device debugged in advance is opened, applies the supersonic frequency that unilateral amplitude is 8 μm to cutter in the axial direction Large-amplitude vibration, by adjusting the phase in vibratory drive source, the vibration of cutter is set to turn into the vibration of a sinusoidal trajectory so that this Cutter is in axial vibration state in working angles afterwards.
3. 3. a kind of difficult processing axial UVC processing method of aeronautical material high speed according to claim 1, it is special Sign is：For this method in a vibration period from a points to e points, high-speed ultrasonic Vibration Cutting Process is divided into three phases：a Point → b points are the incision stage, and for b points → c points to cut out the stage, c points → e points are the cut-in without ball stage；In high-speed ultrasonic vibrocutting Cheng Zhong, cutter do the vibration of supersonic frequency using vibration balancing line as equilbrium position.