Method and device for machining titanium alloy thin-walled cylinder part with small diameter and large length-diameter ratio

Abstract

The invention discloses a small-diameter large-length-diameter-ratio titanium alloy thin-walled cylinder part machining method and device, and relates to the technical field of thin-walled cylinder part turning, the small-diameter large-length-diameter-ratio titanium alloy thin-walled cylinder part machining device comprises a three-jaw chuck, the three-jaw chuck is used for clamping a thin-walled cylinder part, and a supporting rod system penetrating through the three-jaw chuck and the thin-walled cylinder part is installed at the center of the three-jaw chuck and the center of the thin-walled cylinder part; the supporting rod system comprises a long straight rod, an oil way groove is formed in the long straight rod, a small protruding structure and a large protruding structure are arranged on the long straight rod and are both spherical, and the diameter of the large protruding structure is larger than that of the small protruding structure. Bearings are arranged at the two ends of the long straight rod, springs are arranged below the bearings, and the lower portions of the springs are connected to the guide rails through guide rail sliding blocks. A spring damper is arranged at the end, away from the three-jaw chuck, of the thin-walled cylinder part, and by arranging a corresponding supporting rod system, the problems of deformation, flutter and heat management in the turning process of the thin-walled cylinder part are solved.

Description

Technical Field

[0001] The invention relates to the technical field of turning processing of thin-walled tube parts, in particular to a processing method and device of titanium alloy thin-walled tube parts with small diameter and large aspect ratio. Background Art

[0002] The application of thin-walled cylinders in the machinery industry is mainly reflected in their lightweight, high strength and high stiffness characteristics, which make thin-walled cylinders an ideal choice for aerospace, automobile manufacturing, electronic equipment and other fields. Thin-walled cylinders are widely used in the machinery industry, and the continuous advancement of their design and manufacturing technology plays an important role in promoting technological innovation and industrial development in related fields.

[0003] However, when manufacturing and processing thin-walled tubes, due to their thin walls, deformation is easy to occur during the processing, so special attention needs to be paid to the clamping and processing methods to ensure dimensional accuracy and product quality. In addition, the design and manufacturing of thin-walled tubes also need to consider their strength and stability under different working conditions, especially their performance under internal or external pressure. Specifically, there are several difficulties in the process of processing thin-walled tubes, such as the control of deformation, the control of heat dissipation during processing, and the vibration of the workpiece during processing.

[0004] First, the deformation control of the workpiece: due to its thin wall thickness and poor rigidity, the thin-walled tube is easily affected by cutting force, heat, clamping force and other factors during the processing, causing elastic and plastic deformation, which directly affects the dimensional accuracy and shape accuracy of the parts.

[0005] Second, the chatter problem: During the cutting process, many factors can cause chatter, such as improper selection of cutting parameters, different machine tool rigidity, the degree of workpiece clamping, etc. Thin-walled cylindrical workpieces are more likely to vibrate during machining, which not only affects the quality of the machined surface, but may also cause tool damage or machining interruption.

[0006] Third, thermal management: Since machining is mostly a cutting process, there is a lot of friction and plastic deformation. The large amount of friction between the tool and the workpiece will inevitably generate heat. If the generated heat cannot be effectively dissipated, it will cause the local temperature of the workpiece to rise and cause thermal deformation.

[0007] Chinese patent CN117428424A - a method for turning a TC18 titanium alloy thin-walled cylinder. The invention uses a method of inserting a rubber roll into the turned part to reduce the vibration of the part in the processing of thin-walled cylinder parts with a larger inner wall diameter. However, for the thin-walled cylinder parts with small diameters that are mainly discussed in the present invention, the boring bar and other structures used in the mirror processing also need to reduce their own size. First, the diameter of the thin-walled cylinder part itself is small enough, and the size of the boring bar needs to be smaller than that of the thin-walled cylinder part with a small diameter. Its too small diameter will inevitably lead to its rigidity being very small. The small rigidity is easy to deform during the support processing. The support role that the deformed boring bar can play is very limited, and it may even affect the processing in the opposite direction; secondly, when the boring bar structure is running at high speed inside the workpiece, it will inevitably have friction with the workpiece. The friction will damage the inner wall and even the large amount of heat generated by the friction will cause a huge change in the microstructure performance of the inner wall. Therefore, the traditional mirror processing cannot be used to process the thin-walled cylinder parts with small diameters.

[0008] Another example is patent CN116352120A - a processing device for thin-walled cylindrical workpieces. This patent also processes thin-walled cylindrical parts. During processing, the two ends of the processed parts are fixed for turning. In the case of parts with a large aspect ratio in this article, it is easy for the parts to be deformed due to the thermal expansion and contraction caused by the turning force and cutting heat during processing, thereby affecting the processing quality. Summary of the invention

[0009] The purpose of the present invention is to provide a method and device for processing a titanium alloy thin-walled tube part with a small diameter and a large aspect ratio, so as to solve the problems raised in the above-mentioned background technology.

[0010] To achieve the above-mentioned object, the present invention provides the following technical solutions: a processing device for a titanium alloy thin-walled tube part with a small diameter and a large aspect ratio, comprising a three-jaw chuck, the three-jaw chuck is used to clamp the thin-walled tube part, and a support rod system penetrating the three-jaw chuck and the thin-walled tube part is installed at the center thereof;

[0011] The support rod system comprises a long straight rod, an oil groove is arranged on the long straight rod, a small protrusion structure and a large protrusion structure are arranged on the long straight rod, and both are spherical, and the diameter of the large protrusion structure is larger than the diameter of the small protrusion structure;

[0012] Bearings are provided at both ends of the long straight rod, a spring is provided below the bearing, and the lower part of the spring is connected to the guide rail through a guide rail slider, and the guide rail includes an X-axis guide rail and a Y-axis guide rail located on both sides of the X-axis guide rail;

[0013] A spring damper is arranged on one end of the thin-walled cylinder part and away from the three-jaw chuck.

[0014] Preferably, the long straight rod is of elongated shape, and is provided with conical holes which are axially arranged side by side and radially penetrate the rod body.

[0015] Preferably, the small protrusion structure and the large protrusion structure are provided with radial oil path grooves which are perpendicular to the axial direction of the long straight rod.

[0016] Preferably, the small protrusion structure is arranged on both sides of the large protrusion structure, and the small protrusion structure and the large protrusion structure are both provided with round holes aligned with the conical hole.

[0017] Preferably, the small protrusion structure, the large protrusion structure and the long straight rod are fixedly connected by a conical pin.

[0018] Preferably, a shaft sleeve is provided on the outer side of the bearing, and the spring is connected to the shaft sleeve.

[0019] Preferably, the spring damper is symmetrically arranged on both sides of the thin-walled tube part, and a spring damper moving guide rail is provided on the side of the spring damper. The eddy current sensor and the noise sensor are respectively provided on both sides of the spring damper.

[0020] Preferably, a turning tool is provided on the side of the thin-walled tube part for processing, and an acceleration sensor is placed on the back of the turning tool.

[0021] A method for processing a titanium alloy thin-walled tube part with a small diameter and a large aspect ratio, comprising the following steps:

[0022] Step 1: First, according to the size of the thin-walled tube part to be processed, the positions of the small protrusion structure and the large protrusion structure on the long straight rod are calculated and assembled and fixed, and the relationship between the length of the processed part and the length of the long straight rod is determined, so as to select different processing methods;

[0023] Step 2: Install the thin-walled cylinder part to be processed on the three-jaw chuck, install the outer ring of the bearing on the sleeve, connect the sleeve and the spring, and install the other end of the spring on the guide rail slider; install the guide rail slider on the guide rail, and move the guide rail along the Y axis so that the lower end surface of the large protrusion structure contacts the inner wall of the workpiece to be processed;

[0024] Step 3: Install two eddy current sensors perpendicular to each other, and install a noise sensor 3 cm outside the end face of the workpiece to continuously monitor the processing of the parts during the processing. Install the acceleration sensor on the back of the turning tool rod;

[0025] Step 4: Turn on the lathe to process the half of the part away from the three-jaw chuck. Considering the different relationships between the lengths of different parts and the lengths of the long straight rods, different methods are used to support the processed parts, such as using an inclined long straight rod to support the processed parts and using a translational long straight rod to support the processed parts. The processed part is away from the half of the chuck, and then one end of the three-jaw chuck of the part is processed. It is ensured that during the processing, the protrusion structure can change in position with the different processing positions, and can ensure continuous support for the inner wall of the workpiece during processing.

[0026] Step 5: During the parts processing, the noise sensor suddenly receives and monitors a large amount of noise signals, and cooperates with the eddy current sensor to monitor the displacement of the processed workpiece;

[0027] Step 6: After each cutting is completed, the cutting state is predicted to ensure the processing quality. Compared with the prior art, the beneficial effects of the present invention are:

[0028] Step 7: Complete the processing of the parts, and roughly evaluate the processing quality of the parts, repeat and continue to process other parts to be processed;

[0029] 1. The present invention is mainly used for processing thin-walled barrel parts with small diameter and large aspect ratio. First, since the barrel wall thickness of this type of parts is small, a structure different from the ordinary mirror processing must be used to support the parts during cutting, so as to ensure the processing quality of the parts during processing; the present invention adopts a combination of a rod structure different from the ordinary bore rod and a protrusion structure, and uses spring force to support the parts during processing; and different processing data can provide different spring forces for offset and support during cutting;

[0030] 2. Due to the feature of the workpiece having a relatively large length-to-diameter ratio, during turning, the free end of the part that is not clamped by the three-jaw chuck is prone to strong vibration due to its own rotation and the force of cutting. The present invention uses a spring damper to limit the end of the part that is more likely to vibrate. Next, due to continuous cutting and friction during the processing, the heat between the special support structure used in the present invention and the inner wall of the part needs to be processed. Therefore, solid lubrication and liquid lubrication are used in combination to lubricate and dissipate heat between the support structure and the inner wall.

[0031] 3. In the process of machining, the workpiece may have many situations that affect the machining quality of the parts, and the supporting force needs to be controlled and changed according to different cutting conditions. Therefore, the present invention needs to use eddy current sensors, noise sensors and acceleration sensors to monitor and evaluate the displacement of the parts, the processing sound waves and the stability of the turning tool, and continuously change the appropriate spring extension to change the size of the supporting force;

[0032] 4. The addition of solid lubricants in the present invention can greatly reduce the large amount of heat caused by the large amount of friction generated by the support. Similarly, lubricating oil and other lubricating materials need to be continuously added to the axial oil groove of the long straight rod. Since the lubricating oil still has a certain fluidity, it will continue to drip downward under the action of gravity. The lubricating oil dripping on the inner wall of the workpiece contacts the protruding structure and the workpiece, and lubricates the workpiece and the protruding structure at all times. The contact area between the lubricating oil and the inner wall of the workpiece is large, which can achieve the heat dissipation of part of the heat generated by friction, and to a certain extent enhances the thermal control of the workpiece during processing. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 It is an overall schematic diagram of the conventional processing state;

[0034] Figure 2 This is a schematic diagram of the situation where a long straight rod is used for support during processing;

[0035] Figure 3 This is a schematic diagram of the situation where an inclined long straight rod is used for support during processing;

[0036] Figure 4 It is a schematic diagram of the oil circuit on the long straight rod and the protrusion structure;

[0037] In the figure: 1. Bushing; 2. Bearing; 3. Long straight rod; 4. Three-jaw chuck; 5. Small protrusion structure; 6. Large protrusion structure; 7. Thin-walled tube part; 8. Eddy current sensor; 9. Spring damper moving guide rail; 10. Spring damper; 11. Noise sensor; 12. Spring; 13. Guide rail; 14. Turning tool; 15. Acceleration sensor; 16. Guide rail slider; 17. Y-axis drive motor; 18. X-axis drive motor; 19. Y-axis guide rail; 20. X-axis guide rail. DETAILED DESCRIPTION

[0038] 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.

[0039] See also Figures 1 to 4The present invention provides a technical solution: a method and device for processing a small-diameter and large-length-diameter ratio titanium alloy thin-walled tube part, including a three-jaw chuck 4, the three-jaw chuck 4 is used to clamp a thin-walled tube part 7, and a support rod system running through the three-jaw chuck 4 and the thin-walled tube part 7 is installed at the center of the three-jaw chuck 4 and the thin-walled tube part 7. When clamping the large-length-diameter ratio thin-walled tube part 7, the clamping depth should be appropriately larger, otherwise the workpiece is prone to large vibration and deformation during processing when the workpiece is in a long length state. The three-jaw chuck 4 has the characteristic of automatic centering, and can be adjusted according to different workpiece outer diameters, and has strong interchangeability;

[0040] The support rod system includes a long straight rod 3, an oil channel groove is arranged on the long straight rod 3, a small protrusion structure 5 and a large protrusion structure 6 are arranged on the long straight rod 3, and both are spherical, the diameter of the large protrusion structure 6 is larger than the diameter 5 of the small protrusion structure, and the positions of the small protrusion structure 5 and the large protrusion structure 6 are adjustable, and cooperates with the long straight rod 3 to support and process the thin-walled cylinder part 7 with a large aspect ratio, so as to reduce the elastic and plastic deformation caused by factors such as cutting force, heat and clamping force during the processing;

[0041] The two ends of the long straight rod 3 are provided with bearings 2, and the lower part of the bearing 2 is provided with a spring 12, and the lower part of the spring 12 is connected to the guide rail 13 through a guide rail slider 16, and the guide rail 13 includes an X-axis guide rail 20 and a Y-axis guide rail 19 located on both sides of the transverse guide rail. The long straight rod 3 is supported by a small protrusion structure 5 and a large protrusion structure 6 that can adjust the position. The spring 12 is used at both ends of the long straight rod 3 to offset the force in the cutting process through the spring force. The size of the spring force can be changed by the different extension lengths of the spring 12, and in the cutting process, the cutting force that needs to be offset also changes continuously, so the guide rail 13 structure is used to fix the other end of the spring 12. The guide rail 13 can make the guide rail slider 16 move along the transverse guide rail in the X-axis direction, and at the same time, the X-axis guide rail 20 can move along the Y-axis guide rails 19 on both sides in the Y-axis direction. The movement in the Y-axis direction is to change the elongation length of the spring 12. At the same time, the springs 12 on both sides can work independently of each other, and realize different stretching, contraction, translation and other changes according to different processing states of the thin-walled tube part 7. The movement of the spring 12 in the horizontal direction is to move the position of the small protrusion structure 5 and the large protrusion structure 6 when the tool 14 processes different horizontal positions of the workpiece, so as to support and adapt to the workpiece processing;

[0042] The specific ways of achieving movement of the X-axis guide rail 20 and the guide slider 16 are different. The X-axis guide rail 20 is installed between the Y-axis guide rails 19, and a Y-axis drive motor 17 and its gears engaged with the Y-axis guide rail 19 are installed on one side of the X-axis guide rail 20. The rotation of the gears drives the X-axis guide rail 20 to slide in the Y-axis direction; an X-axis drive motor 18 and its gears are installed on the guide slider 16. The gears are engaged with the X-axis guide rail 20, so that when the gears rotate, the guide slider 16 can be driven to slide along the X-axis direction.

[0043] A spring damper 10 is provided on the thin-walled tube part 7 and at one end away from the three-jaw chuck 4. The spring damper 10 is symmetrically installed on both sides of the workpiece to be processed. The spring force can also be changed by adjusting the compression length of the spring 12 to dynamically offset the cutting force under different cutting conditions. The installation and use of the spring damper 10 enables the present invention to effectively suppress the vibration phenomenon of the workpiece during the processing. However, since the processing method of the present invention has multiple processing structures, as long as there is a large amount of friction during the cutting process, attention must be paid to heat control. There is a large amount of friction between the spring damper 10 and the workpiece to be processed, and special design is required on the parts where the spring damper 10 rubs against the workpiece. There are oil circuits and oil delivery holes on the spring damper 10, and lubricants are continuously added to reduce the heat generated by the friction between the spring damper 10 and the workpiece during the cutting process.

[0044] The lubricant uses a solid lubricant, which has a larger temperature-width ratio than oil and grease lubrication and has the characteristics of high load-bearing capacity, good wear resistance, excellent friction performance, good temperature adaptability and timeliness. In the present invention, graphite, molybdenum disulfide, polyimide / molybdenum disulfide composite and AB glue / molybdenum disulfide composite are used as solid lubricants. The graphite material itself has lubricity. The graphite atoms are small. If heated, they diffuse into the metal to form metal carbides, which have good adhesion; the graphite has excellent toughness and strong manufacturability. Molybdenum disulfide is a solid powder with a black-gray luster made by complex chemical and mechanical treatment. It has a hexagonal layered structure. The strong combination of sulfur atoms and molybdenum atoms determines that molybdenum disulfide has strong compressive resistance. The sulfur atoms and metals have strong bonding forces, which makes it have strong adsorption characteristics. Although molybdenum disulfide will be partially converted into molybdenum trisulfide when the operating temperature reaches 540°C, it still has good lubrication properties. The addition of solid lubricants can greatly reduce the large amount of heat caused by the large amount of friction generated during support. Similarly, lubricating oil and other lubricating materials need to be continuously added to the axial oil groove of the long straight rod 3. Since the lubricating oil still has a certain fluidity, it will continue to drip downward under the action of gravity. The lubricating oil dripping on the inner wall of the workpiece contacts the protruding structure and the workpiece, lubricating the workpiece and the protruding structure at all times. The contact area between the lubricating oil and the inner wall of the workpiece is large, which can achieve the heat dissipation of part of the heat generated by friction, and to a certain extent enhances the thermal control of the workpiece during processing.

[0045] In this embodiment, the long straight rod 3 is slender in shape, and is provided with conical holes radially penetrating the rod body and arranged axially side by side, for mounting the small protrusion structure 5 and the large protrusion structure 6 .

[0046] In this embodiment, radial oil grooves perpendicular to the axial direction of the long straight rod 3 are provided on the small protrusion structure 5 and the large protrusion structure 6 for filling with solid lubricant.

[0047] In this embodiment, the small protrusion structure 5 is arranged on both sides of the large protrusion structure 6. The small protrusion structure 5 and the large protrusion structure 6 are both provided with round holes aligned with the conical holes. Smaller small protrusion structures 5 are installed at both ends of the long straight rod 3. The smaller small protrusion structure 5 can prevent the thin-walled tube part 7 from being bent significantly. The smaller small protrusion structure 5 does not contact the thin-walled tube part 7 during the work process of using the large protrusion structure to support. If the smaller protrusion contacts the thin-walled tube part 7 during the work process of using the large protrusion structure to support, it means that the thin-walled tube part 7 has been deformed, and the tension of the spring 12 needs to be reduced immediately so that the workpiece does not produce plastic deformation and affect the processing accuracy. The small protrusion structure 5 of the device of the present invention is movable, and its movement means that before processing different processing parts (after the lathe is stopped), its position is changed, that is, when facing different workpiece lengths, the position of the protrusion can be replaced and adapted by taking out the positioning pin and reinstalling it.

[0048] See Figure 2 , Figure 3 , it can be seen that the marked L0 represents the effective length of the long straight rod, and L1 represents the length of the processed part. If L1≤L0 / 2, the same processing method as normal is adopted, that is, the position of the long straight rod in the X-axis direction is continuously moved, so that the large protrusion can change with the change of the processing position, thereby achieving support for the processed part. When L1>L0 / 2, when the small protrusion structure 5 is at a position far away from the center of the processed workpiece (that is, the latter half of the processed part), the long straight rod 3 can be tilted so that the small protrusion structure 5 on it and the inner wall of the processed thin-walled tube part 7 are in contact and supported. The solution for tilting the long rod is to move the single-sided guide rail 13 vertically to tilt the long straight rod 3. In this case, the small protrusion structure 5 can support the inner wall of the workpiece and the tension force offsets the various forces during cutting. Similarly, the guide rail 13 can be used to control the length of the spring 12 to provide support of different strengths. The method for tilting the long straight rod is that the X-axis guide rail 20 on the right side of the figure is moved toward the negative direction of the Y-axis by the Y-axis driving motor 17, thereby driving the X-axis guide rail 20 close to the chuck to move toward the negative direction of the Y-axis, while the X-axis guide rail 20 far from the chuck is slid toward the positive direction of the Y-axis by the Y-axis driving motor 17, thereby realizing the tilting of the long straight rod.

[0049] In this embodiment, the small protrusion structure 5, the large protrusion structure 6 and the long straight rod 3 are fixedly connected by a conical pin.

[0050] In this embodiment, a sleeve 1 is provided on the outer side of the bearing 2 , and the spring 12 is connected to the sleeve 1 .

[0051] In this embodiment, the spring damper 10 is symmetrically arranged on both sides of the thin-walled tube part 7, and the side of the spring damper 10 is provided with a spring damper moving guide rail 9. The two sides of the spring damper 10 are respectively provided with an eddy current sensor 8 and a noise sensor 11. The eddy current sensor 8 can measure the displacement, vibration and other parameters with high precision during the processing. These data can reflect the processing accuracy and the normal operation of the processing. The eddy current sensor 8 is based on Faraday's law of electromagnetic induction. By generating an induced current on the surface of the metal body to be measured, and measuring the eddy current change, the distance between the metal body and the sensor is determined. This measurement method is non-contact, which can avoid damage to the object to be measured, and has high sensitivity and anti-interference ability. The present invention uses two vertically placed eddy current sensors 8 to monitor the displacement and vibration of the workpiece when it is processed, and feedback data in real time. Since the present invention uses the tensioning force of the spring 12 to overcome the cutting force during the processing when providing support, the guide rail 13 is used to reduce or increase the elongation distance of the spring 12 and other data, so as to achieve the change of the supporting force, thereby affecting the stable state and stress condition of the workpiece. By utilizing the guide rail 13 in conjunction with sensor feedback data, the cutting force that changes in real time can be offset and overcome in real time.

[0052] The present application is equipped with a noise sensor 11. By real-time collection and analysis of noise signals, the noise sensor 11 can help operators to promptly detect potential processing problems and take corresponding adjustment measures, such as changing cutting parameters, replacing tools or stopping the machine for inspection, to ensure processing quality and improve production efficiency.

[0053] In this embodiment, a turning tool 14 is provided on the side of the thin-walled tube part 7, and an acceleration sensor 15 is placed on the back of the turning tool 14. The acceleration sensor 15 is installed on the back of the turning rod of the turning tool 14 to monitor vibration and impact during the cutting process, which is crucial to improving the processing quality and tool life. It can also help achieve the dynamic balance of the turning tool 14, avoid vibration and potential mechanical failures caused by imbalance, and provide real-time feedback data, so as to dynamically adjust the elongation length of the spring and adjust the balance of the processing.

[0054] A method for processing a titanium alloy thin-walled tube part with a small diameter and a large aspect ratio, comprising the following steps:

[0055] Step 1: First, according to the size of the thin-walled tube part 7 to be processed, the position between the small protrusion structure 5 and the large protrusion structure 6 on the long straight rod 3 is calculated and assembled and fixed;

[0056] And determine the different processing methods, see Figure 2 , Figure 3The length of the processed part is marked as L1 and the length of the long straight rod is marked as L0. The values ​​of L1 and L0 / 2 can be used for comparison. When L1>L0 / 2, it is necessary to use the tilted long straight rod method for processing, and when L1<L0 / 2, it is necessary to use the translated long straight rod method for processing.

[0057] The assembly and fixation need to be adjusted according to the length of the part to be processed. The position of the small protrusion structure 5 needs to refer to the length of the part to be processed, and is generally smaller than the length of the part to be processed. The small protrusion structure 5 needs to be installed symmetrically with respect to the large protrusion structure 6. A radial oil circuit is opened on the large protrusion structure 6 and a solid lubricant is installed. The solid lubricant is composed of graphite, molybdenum disulfide, polyimide / molybdenum disulfide composite and AB glue / molybdenum disulfide composite. A lubrication system is also required on the small protrusion structures 5 at both ends, and the method adopted is to add lubricating oil to the axial oil circuit. The lubricating oil will continue to drip during the lubrication and transportation process, but the overall lubrication continues on the lower surface of the inner wall of the workpiece, and the lubrication and heat dissipation effects are very good.

[0058] Step 2: Install the thin-walled cylindrical part 7 to be processed on the three-jaw chuck 4. The other end of the jaws of the three-jaw chuck 4 is hollow, so that the combination of the protrusion structure and the long straight rod 3 can pass through. After the long straight rod 3 and the protrusion structure are combined and passed through, bearings are installed at both ends. Install the outer ring of the bearing 2 on the sleeve, connect the sleeve 2 and the spring 12, and install the other end of the spring 12 on the sleeve. Install the sleeve on the guide rail 13, and the guide rail 13 can move along the X-axis and Y-axis directions. Start the Y-axis drive motor 17 to move the guide rail 13 in the negative direction of the Y-axis so that the lower end face of the large protrusion structure 6 contacts the inner wall of the workpiece being processed, achieving constant support and lubrication. At the other end of the part to be processed that is not fixed, install and use the spring damper 10 to fix the part to be processed. The damping condition of the spring damper 10 can be adjusted at any time.

[0059] Step 3: Install two eddy current sensors 8 perpendicularly to each other, and install a noise sensor 11 3 cm outside the end face of the workpiece, so that it can continuously monitor the processing status of the parts during the processing, and install the acceleration sensor 15 on the back of the turning tool 14 turning rod;

[0060] The turning process begins, and the processing is first started from the end of the thin-walled tube part 7 away from the three-jaw chuck 4. Since step 1 has determined different processing methods for the processed parts, this step needs to be discussed and elaborated on in different situations.

[0061] Case 1: If Figure 2, when L1<L0 / 2, the processing is performed by translating the long straight rod 3. The specific implementation method is to use the X-axis drive motor 18 on two sets of guide rails (i.e., two sets of guide rails close to and away from the three-jaw chuck, respectively, each of which includes an X-axis guide rail 20 and two Y-axis guide rails 19) to move the guide rail slider 16 along the positive direction of the X-axis, thereby driving the long straight rod 3 and its protruding structure to move in the positive direction of the X-axis, so that when the turning tool is processing the workpiece away from one end of the three-jaw chuck 4, the inner wall of the position processed by the turning tool has a large protrusion structure to support it. As the turning tool is processed, its processing position moves toward one end of the three-jaw chuck 4, and its internal support also needs to maintain continuous support for the turning tool processing position. The implementation method is that the X-axis drive motors 18 on the left and right guide rails rotate in the same direction at the same time, so that the protrusion structure, i.e., the long straight rod 3 and other structures, can achieve X-axis movement. The processing method adopts the large protrusion structure 6 to support the processed part, and utilizes the movement of the long straight rod 3 in the X-axis direction to achieve the follow-up support of the large protrusion structure 6 during turning tool processing.

[0062] After processing the end of the workpiece away from the chuck, since the length of the workpiece is relatively short (i.e., L1 < L0 / 2), the long straight rod 3 is continued to be moved in the X-axis direction, and the large protrusion structure 6 is continued to be moved to follow the turning tool processing to support it, thereby completing one pass of the entire part.

[0063] Case 2: If Figure 3 , when L1>L0 / 2, the long straight rod 3 is tilted for processing. The overall processing process is divided into four stages, which can be roughly divided into the first tilt support, reset horizontal support, second tilt support and reset tilt support. The principle of the distinction is that due to the longer length of the processed parts (i.e. L1>L0 / 2), whether it is horizontal support or tilt support, the end of the effective area of ​​the long straight rod 3 needs to collide with the parts before it can continue to support. Therefore, different support methods need to be adopted to avoid poor support effects during the processing process.

[0064] The specific implementation method of the first tilt support is: use the X-axis guide rail 20 in the guide rail structure close to the chuck to move along the positive direction of the Y-axis, and the X-axis guide rail 20 in the guide rail structure away from the chuck to move along the negative direction of the Y-axis, thereby driving the end of the long straight rod 3 close to the chuck to move toward the positive direction of the Y-axis, and the end of the long straight rod 3 away from the chuck to move toward the negative direction of the Y-axis, so that the long straight rod 3 rotates clockwise in the direction shown in the figure, so that the small protrusion structure 5 close to the chuck on the long straight rod 3 is in contact with the inner wall of the machined part for support, and its X-axis position is moved so that it can follow the continuous movement of the turning tool to achieve the effect of accompanying support. When the turning tool is processing the part away from one end of the chuck, the small protrusion structure 5 is used to process the part. The implementation method is to use the inclined long straight rod 3 so that the small protrusion can contact and support the part during processing. Therefore, when the turning tool is processing the part away from one end of the chuck, the X-axis drive motor 18 is required to drive the X-axis guide rail 20 to move continuously in the negative direction of the X-axis, so that the small protrusion structure 5 can continuously contact and support the part.

[0065] The specific implementation method of resetting the horizontal support is: when the tool is close to the limit position that the small protrusion can support when the long straight rod is tilted, the Y-axis drive motor 17 close to the chuck needs to drive the X-axis guide rail close to the chuck to move in the positive direction of the X-axis; the Y-axis drive motor 17 away from the chuck needs to drive the X-axis guide rail away from the chuck to move in the negative direction of the Y-axis, and the X-axis drive motor needs to drive the long straight rod 3 to move in the positive direction of the X-axis, thereby realizing the horizontal return of the long straight rod 3 and the large protrusion structure moving in the positive direction of the X-axis to continuously support the turning of the turning tool. This process realizes the transformation process from the support of the small protrusion structure 5 to the support of the large protrusion structure.

[0066] The specific implementation method of the second tilt support is: during the continued processing, there is an extreme position that the large protrusion structure 6 can support. When approaching this position, the Y-axis drive motor 17 close to the chuck needs to drive the X-axis guide rail 20 close to the chuck to move in the negative direction of the Y axis, and the Y-axis drive motor 17 away from the chuck drives the X-axis guide rail 20 away from the chuck to move in the positive direction of the Y axis, that is, the end of the long straight rod 3 close to the chuck moves in the negative direction of the Y axis and the end away from the chuck moves in the positive direction of the Y axis, thereby realizing the tilt of the long straight rod 3, so that the long straight rod 3 and its protrusion structure rotate counterclockwise; at the same time, the X-axis drive motor needs to drive the long straight rod 3 to move in the positive direction of the X axis, so that the small protrusion structure 5 on the side of the long straight rod 3 close to the chuck can support the processed parts. And in the process of processing, with the continuous processing of the turning tool, the accompanying support of the small protrusion structure 5 for the processed parts is realized.

[0067] The implementation method of resetting the tilt support is: after a cutting is completed, the turning tool returns to the end of the processed part away from the chuck, so it is necessary to rotate the long straight rod 3 in the clockwise direction, so that the small protrusion structure 5 of the long straight rod away from the chuck can support the processed part. In this process, the X-axis guide rail 20 in the guide rail structure close to the chuck is moved along the positive direction of the Y axis, and the X-axis guide rail 20 in the guide rail structure close to the chuck is moved along the negative direction of the Y axis, thereby driving the end of the long straight rod 3 close to the chuck to move in the positive direction of the Y axis, and the end of the long straight rod 3 away from the chuck is moved in the negative direction of the Y axis, so that the long straight rod 3 rotates clockwise in the direction shown in the figure, so that the right small protrusion structure on the long straight rod 3 and the inner wall of the processed part are in contact and supported, and its X-axis position is moved so that it can achieve the effect of accompanying support.

[0068] In the continuous tool passing process, the first tool passing needs to experience the first tilt support, and the subsequent tool passing only needs to repeatedly reset the horizontal support, the second tilt support and reset the tilt support, so as to continuously process the parts.

[0069] Step 4: During the part processing, the noise sensor 11 suddenly receives and monitors a large amount of noise signals, and cooperates with the eddy current sensor 8 to monitor the displacement of the processed workpiece;

[0070] During the processing, if the signal received by the computer connected to the sensor is analyzed to determine that the workpiece has a large degree of vibration, it is necessary to adjust the damping force of the spring damper 10. A larger damping force can quickly and stably reduce the vibration of the workpiece. When the noise sensor 11 receives a large noise signal but the eddy current sensor 8 does not detect obvious workpiece displacement, it is necessary to consider based on experience whether the larger elongation of the spring 12 causes the protrusion structure to have too much support on the workpiece, thereby affecting the workpiece, causing it to deform and bend, affecting the processing quality and the dimensional accuracy of the parts. When monitoring and analyzing possible workpiece deformation, it is necessary to move the guide rail slider 16 on the guide rail 13 vertically to drive the spring 12 to reduce the elongation of the spring, so that the support force of the protrusion structure is reduced, thereby ensuring the quality of processing.

[0071] Step 5: After each cutting, predict the cutting status to ensure the processing quality.

[0072] After a single cutting is completed, cutting is performed again from the end of the part away from the three-jaw chuck 4. Similarly, it is necessary to use the guide rail 13 to drive the guide rail slider 16 to move the long straight rod 3 and the protrusion structure to change the elongation of the spring 12 or the horizontal position of the large protrusion structure 6, and finally support the turning tool 14.

[0073] Further, steps three, four, and five are continuously repeated to process the parts and change the outer diameter of the parts to meet the processing requirements.

[0074] It is known from common technical knowledge that the present invention can be implemented by other embodiments that do not deviate from its spirit or essential features. Therefore, the above disclosed embodiments are only illustrative in all respects and are not exclusive. All changes within the scope of the present invention or within the scope equivalent to the present invention are included in the present invention.

Claims

1. A processing device for titanium alloy thin-walled tube parts with small diameter and large aspect ratio, characterized in that: It comprises a three-jaw chuck (4), the three-jaw chuck (4) is used to clamp a thin-walled tube part (7), and a support rod system penetrating the three-jaw chuck (4) and the thin-walled tube part (7) is installed at the center of the three-jaw chuck (4) and the thin-walled tube part (7); The support rod system comprises a long straight rod (3), an oil path groove is arranged on the long straight rod (3), a small protrusion structure (5) and a large protrusion structure (6) are arranged on the long straight rod (3), and both are spherical, and the diameter of the large protrusion structure (6) is larger than the diameter of the small protrusion structure (5); Bearings (2) are provided at both ends of the long straight rod (3), a spring (12) is provided below the bearing (2), the spring (12) is connected to the guide rail (13) below through a guide rail slider (16), the guide rail (13) comprises an X-axis guide rail (20) and a Y-axis guide rail (19) located on both sides of the X-axis guide rail (20), an X-axis drive motor (18) is installed on the guide rail slider (16), and a Y-axis drive motor (17) is installed on the Y-axis guide rail, which are responsible for driving the guide rail slider (16) to move along the X-axis direction and the X-axis guide rail (20) to move along the Y-axis direction respectively; A spring damper (10) is provided on one end of the thin-walled tube part (7) away from the three-jaw chuck (4).

2. The device for processing titanium alloy thin-walled tube parts with small diameter and large aspect ratio according to claim 1 is characterized in that: The long straight rod (3) is of elongated shape and is provided with conical holes which are axially arranged side by side and radially penetrate the rod body.

3. The device for processing titanium alloy thin-walled tube parts with small diameter and large aspect ratio according to claim 1 is characterized in that: The small protrusion structure (5) and the large protrusion structure (6) are provided with radial oil path grooves which are perpendicular to the axial direction of the long straight rod (3).

4. The device for processing titanium alloy thin-walled tube parts with small diameter and large aspect ratio according to claim 2 is characterized in that: The small protrusion structure (5) is arranged on both sides of the large protrusion structure (6), and the small protrusion structure (5) and the large protrusion structure (6) are both provided with circular holes aligned with the conical holes.

5. The device for processing titanium alloy thin-walled tube parts with small diameter and large aspect ratio according to claim 4 is characterized in that: The small protrusion structure (5), the large protrusion structure (6) and the long straight rod (3) are fixedly connected via a conical pin.

6. The device for processing titanium alloy thin-walled tube parts with small diameter and large aspect ratio according to claim 1 is characterized in that: A shaft sleeve (1) is provided on the outer side of the bearing (2), and the spring (12) is connected to the shaft sleeve (1).

7. The device for processing titanium alloy thin-walled tube parts with small diameter and large aspect ratio according to claim 1 is characterized in that: The spring damper (10) is symmetrically arranged on both sides of the thin-walled tube part (7) in an upper and lower manner, a spring damper moving guide rail (9) is arranged on the side of the spring damper (10), and an eddy current sensor (8) and a noise sensor (11) are respectively arranged on both sides of the spring damper (10).

8. The device for processing titanium alloy thin-walled tube parts with small diameter and large aspect ratio according to claim 1 is characterized in that: A turning tool (14) is provided on the side of the thin-walled tube part (7), and an acceleration sensor (15) is arranged on the back of the turning tool (14).

9. A method for machining a small-diameter and large-aspect-ratio titanium alloy thin-walled tube part using the machining device described in claims 1-8, characterized in that: The following steps are involved: Step 1: First, according to the size of the thin-walled tube part (7) to be processed, the position between the small protrusion structure (5) and the large protrusion structure (6) on the long straight rod (3) is calculated and assembled and fixed, and two different processing methods are distinguished according to the comparison between the length of the processed part and the length of the long straight rod; Step 2: Install the thin-walled cylindrical part (7) to be processed on the three-jaw chuck (4), install the outer ring of the bearing (2) on the sleeve (1), connect the sleeve (1) and the spring (12), and install the other end of the spring (12) on the guide rail slider (16); install the guide rail slider (16) on the guide rail (13), and move the guide rail (13) so that the lower end surface of the large protrusion structure (6) contacts the inner wall of the workpiece to be processed; Step 3: Install two eddy current sensors (8) perpendicularly to each other, and install a noise sensor (11) 3 cm outside the end surface of the workpiece so that it can continuously monitor the processing status of the part during the processing, and install an acceleration sensor (15) on the back of the turning rod of the turning tool (14); Step 4: During the process of parts processing, the noise sensor (11) suddenly receives and monitors a large amount of noise signals, and cooperates with the eddy current sensor (8) to monitor the displacement of the processed workpiece; Step 5. After each tool pass is completed, the cutting state is predicted to ensure the processing quality, and the position of the long straight rod is continuously changed to change the position of the protruding structure to support and process the processing position of the turning tool.

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