A rotary positioning machining device for a numerically controlled lathe

Abstract

The present invention relates to the technical field of numerically controlled lathes, and discloses a rotary positioning machining device for a numerically controlled lathe, which includes a lathe body. A positioning part is installed inside the lathe body and is used to adjust the machining position of the workpiece. A clamping part is installed on the positioning part and is used to clamp workpieces of different sizes. A compensation part is installed on the positioning part. A motor drives a threaded rod to drive a slider and a chassis to move, solving the problems of reduced accuracy and jamming caused by long-term stress fatigue of the traditional threaded lead screw. After the motor stops, the compensation part is driven by a linear motor to work. The compensation rod and the ball enter the circulation groove of the three-jaw chuck to form a triangular limit. The ball rolls in the circulation groove, effectively overcoming the wear of the cutting force on the three-jaw chuck and the output shaft of the motor, ensuring the clamping stability and rotational stability of the three-jaw chuck under long-term operation, avoiding deviation and shaking, and thus improving the positioning accuracy.

Description

Technical Field

[0001] The invention relates to the technical field of numerically controlled lathes, in particular to a rotary positioning processing device for numerically controlled lathes. Background Art

[0002] In the field of modern mechanical processing, CNC lathes play an extremely important role and are widely used in the processing and manufacturing of rotating parts such as shafts and discs. As the manufacturing industry continues to increase its requirements for product precision, complexity and production efficiency.

[0003] According to the Chinese patent publication number CN209439462U, the patent relates to a rotary positioning type CNC lathe cutting fixture, including a base body and a worm, a worm is installed inside the base body, and a worm wheel is provided on the outside of the worm, and a fixed support column is fixed inside the worm wheel, a support rod is connected inside the fixed support column, and a fixed frame is fixed on the top of the support rod, the inner wall of the fixed frame is fixed with a limiting groove, and a screw rod and a moving block are provided. The connection between the screw rod and the moving block is a threaded connection, and then the moving block is well driven to move by the rotation of the screw rod, thereby driving the three-jaw chuck to move well by the movement of the moving block, so that the three-jaw chuck drives the workpiece to move well, so that the cutting end of the workpiece and the cutting tool are well positioned, so that the cutting tool can cut again.

[0004] However, in CNC lathe machining, a common method is to use a threaded screw to rotate and drive the fixture into the appropriate turning position for positioning. After long-term turning operations, the threads are subjected to long-term stress and fatigue, resulting in thread pitch distortion. This not only causes positioning accuracy to decrease, but can even cause positioning to become stuck, thereby increasing maintenance costs. Therefore, a rotary positioning processing device for CNC lathes is proposed to solve the above-mentioned problems. Summary of the Invention

[0005] (1) Technical problems solved

[0006] In response to the deficiencies in the prior art, the present invention provides a rotary positioning processing device for a CNC lathe, which solves the problem that the threaded screw is fatigued by the cutting force for a long time, which reduces the positioning accuracy and even causes positioning jamming, thereby increasing maintenance costs.

[0007] (2) Technical solution

[0008] To achieve the above object, the present invention provides the following technical solution: A rotary positioning machining device for a numerically controlled lathe, including a lathe body, a positioning part is installed inside the lathe body for adjusting the machining position of the workpiece, a clamping part is installed on the positioning part for clamping workpieces of different sizes, a compensation part is installed on the positioning part for compensating the offset of the workpiece caused by the cutting force, and a protection part is installed inside the lathe body for preventing the flying of falling chips.

[0009] Preferably, the positioning part includes a slide table, the slide table is installed in the turning area of the lathe body, a chute is opened at the top of the slide table, a motor one is installed on the side wall of the slide table, a threaded rod is fixedly connected to the output shaft of the motor one, the end of the threaded rod movably penetrates into the chute and is rotatably connected to the inner wall of the chute, a slider is threadedly sleeved on the outer wall of the threaded rod, the slider is slidably connected to the inner wall of the chute, a chassis is installed on the top of the slider, and the bottom of the outer wall of the chassis is attached to the top of the slide table.

[0010] Preferably, the clamping part is arranged on the chassis, the clamping part includes a three-jaw chuck, a circulation groove is opened on the side of the three-jaw chuck away from the jaws, the circulation groove is annular in structure and the inner wall is arc-shaped, and an opening disk is installed at the center of the side of the three-jaw chuck away from the jaws.

[0011] Preferably, a motor two is installed inside the chassis, the output shaft of the motor two movably penetrates the chassis, the opening disk and the three-jaw chuck are both fixedly sleeved on the penetrating end of the output shaft of the motor two, the center of the output shaft of the motor two is aligned with the center of the opening disk and the center of the three-jaw chuck, and a photoelectric sensor is installed on the penetrating end of the output shaft of the motor two, and the photoelectric sensor is located inside the opening disk.

[0012] Preferably, the compensation part includes two linear motors, the two linear motors are symmetrically installed on both sides of the slide table, L-shaped sliders are installed on the moving parts of the two linear motors, a support plate is fixedly connected between the two L-shaped sliders, a pressure sensor is installed on the side of the support plate close to the chassis, a compensation plate is installed on the pressure sensor, and the compensation plate is attached to the chassis.

[0013] Preferably, the compensation part further includes compensation rods, the number of the compensation rods is three and they are evenly distributed on the compensation plate, one ends of the three compensation rods are fixedly connected to the compensation plate, balls are installed on the other ends of the three compensation rods, and each ball is attached to the inner wall of the circulation groove.

[0014] Preferably, the protection part includes two mounting plates, both of the two mounting plates are mounted in the turning area of the lathe body, a protective cover is mounted on the side wall of one of the mounting plates, a winding roller is rotatably connected between the two mounting plates, one end of the winding roller movably penetrates into the protective cover, a torsion spring is fixedly sleeved on the penetrating end of the winding roller, the torsion spring is elastically connected between the inner wall of the protective cover and the adjacent mounting plate, and a steel belt is wound on the winding roller.

[0015] Preferably, the movable end of the steel belt is fixedly connected to the outer wall of the machine box, and the bottom of the steel belt is attached to the top of the sliding table.

[0016] Preferably, a baffle is mounted on the workbench in the turning area of the lathe body, scraping plates are integrally connected to both sides of the baffle, both of the two scraping plates are inclined and symmetrically arranged, and the bottoms of the two scraping plates are attached to the top of the steel belt.

[0017] Preferably, a collecting groove is formed in the workbench in the turning area of the lathe body, the collecting groove is located below the movable end of the steel belt, and the center line of the collecting groove is aligned with the center line of the baffle.

[0018] (III) Beneficial effects

[0019] Compared with the prior art, the present invention provides a rotary positioning machining device for a numerically controlled lathe, which has the following beneficial effects:

[0020] 1. For the rotary positioning machining device of the numerically controlled lathe, the first motor drives the threaded rod to drive the slider and the machine box to move, solving the problems that the traditional threaded lead screw is prone to fatigue under long-term stress, resulting in reduced accuracy and jamming. After the first motor stops, the linear motor drives the compensation part to work, the compensation rod and the ball enter the circulating groove of the three-jaw chuck to form a triangular limit, and the ball rolls in the circulating groove, effectively overcoming the wear of the cutting force on the three-jaw chuck and the output shaft of the second motor, ensuring the clamping stability and rotational stability of the three-jaw chuck under long-term operation, avoiding deviation and shaking, and thus improving the positioning accuracy.

[0021] 2. For the rotary positioning machining device of the numerically controlled lathe, a photoelectric sensor is mounted on the penetrating end of the output shaft of the second motor, the perforated disc rotates with the second motor, the rotational speed is calculated by the photoelectric sensor, at high rotational speeds, the photoelectric sensor prompts the pressure sensor to start, when the tool cuts the workpiece to generate resistance, the ball rolls in the circulating groove to overcome the resistance, correcting the axial force of the output shaft of the second motor to the correct position, avoiding damage to the output shaft of the second motor caused by long-term cutting operation, and thus preventing shaking and deviation, and prolonging the service life of the second motor and related components.

[0022] 3. The rotary positioning machining device of this CNC lathe. When facing the cutting of larger or harder workpieces, the cutting force increases, resulting in an increase in the resistance on the three-jaw chuck, the output shaft of the second motor, and the machine case. The compensation plate and the compensation rod can sense the pressure change, drive the linear motor to work through an electrical signal. The linear motor drives the support plate to push the compensation plate to provide a force equal to and opposite to the resistance to pull the machine case. The compensation rod abuts against the three-jaw chuck to compensate for the cutting force, preventing the cutting force from causing destructive damage to the output shaft of the second motor and the threaded rod, improving the overall durability of the equipment, and reducing the maintenance cost.

[0023] 4. The rotary positioning machining device of this CNC lathe. The steel belt of the protection part always maintains tension under the action of the torsion spring. Its movable end is connected to the machine case, which can effectively prevent debris from getting stuck in the equipment gap in the turning operation area. The scraping plates on both sides of the baffle on the workbench in the turning area are attached to the steel belt, and automatically scrape off metal debris during the winding and unwinding process of the steel belt. The debris falls into the aggregate tank for recycling, realizing automatic scraping of residual debris, improving the usability, reducing the pressure of manual cleaning. At the same time, the steel belt uses thin steel material, with good winding and releasing effects, good steel surface hardness and smoothness, reducing the adhesion of metal debris.

[0024] 5. The rotary positioning machining device of this CNC lathe. The three-jaw chuck of the clamping part can adapt to the clamping requirements of workpieces of different sizes. With the drive of the first motor in the positioning part, it can conveniently position the workpiece to the appropriate machining position. And the lathe body can be configured with a robotic arm to cooperate with the tool operation, enhancing the machining flexibility and being applicable to a variety of machining scenarios. Brief Description of the Drawings

[0025] Figure 1 It is a schematic diagram of the overall structure of a rotary positioning machining device of a CNC lathe proposed by the present invention;

[0026] Figure 2 It is a connection diagram of the positioning part, clamping part, compensation part, and protection part of a rotary positioning machining device of a CNC lathe proposed by the present invention;

[0027] Figure 3 It is a schematic diagram of the structure of the positioning part of a rotary positioning machining device of a CNC lathe proposed by the present invention;

[0028] Figure 4 It is a schematic diagram of the structure of the protection part of a rotary positioning machining device of a CNC lathe proposed by the present invention;

[0029] Figure 5 It is a schematic diagram of the structure of the clamping part and compensation part of a rotary positioning machining device of a CNC lathe proposed by the present invention;

[0030] Figure 6 It is an enlarged view of the compensation rod and the ball of a rotary positioning machining device of a CNC lathe proposed by the present invention;

[0031] Figure 7 Internal structure schematic diagram of the rotating positioning machining device of a numerically controlled lathe proposed by the present invention for the lathe body.

[0032] In the figure: 1, lathe body; 2, positioning part; 21, slide table; 22, chute; 23, motor 1; 24, threaded rod; 25, chassis; 3, clamping part; 31, three-jaw chuck; 32, circulating groove; 33, perforated disc; 4, compensation part; 41, linear motor; 42, L-shaped slider; 43, support plate; 44, pressure sensor; 45, compensation plate; 46, compensation rod; 47, ball; 5, protection part; 51, mounting plate; 52, protective cover; 53, winding roller; 54, torsion spring; 55, steel strip; 6, baffle; 7, aggregate chute. Specific implementation manner

[0033] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0034] Please refer to Figure 1-7 , the present invention provides a technical solution: a rotating positioning machining device for a numerically controlled lathe, including a lathe body 1. This lathe uses a CK61508 model characteristic numerical control machine tool for the cutting operation of workpieces. In this case, the positioning part 2 is installed inside the lathe body 1 for adjusting the machining position of the workpiece. The clamping part 3 in this case is installed on the positioning part 2 for clamping workpieces of different sizes. The compensation part 4 in this case is installed on the positioning part 2 for compensating the offset of the workpiece caused by the cutting force. The protection part 5 in this case is installed inside the lathe body 1 for preventing the flying of falling chips.

[0035] In the present invention, the common rotation of a threaded lead screw is used for the positioning and adjustment of the machining position. The positioning part 2 in this case includes a slide table 21. The slide table 21 is installed in the turning area of the lathe body 1. A chute 22 is opened at the top of the slide table 21. A motor 1 23 is installed on the side wall of the slide table 21. The motor 1 23 can use a DC motor, which has characteristics such as good speed regulation performance and large starting torque. By changing the armature voltage or excitation current, the speed of the motor can be conveniently adjusted. In this case, parameters such as voltage, current, speed, and torque need to be considered according to the actual production situation, so no limitation is made. A threaded rod 24 is fixedly connected to the output shaft of the motor 1 23. The end of the threaded rod 24 movably penetrates into the inside of the chute 22 and is rotatably connected to the inner wall of the chute 22. A slider is threadedly sleeved on the outer wall of the threaded rod 24. The slider is slidably connected to the inner wall of the chute 22. A chassis 25 is installed on the top of the slider. The bottom of the outer wall of the chassis 25 is attached to the top of the slide table 21.

[0036] In this embodiment, in order to effectively clamp workpieces of different sizes, the clamping part 3 of this case is arranged on the chassis 25. The clamping part 3 includes a three-jaw chuck 31. A circulation groove 32 is formed on the side of the three-jaw chuck 31 away from the jaws. The circulation groove 32 is of an annular structure and its inner wall is of an arc structure. An opening disk 33 is installed at the center of the side of the three-jaw chuck 31 away from the jaws. A second motor is installed inside the chassis 25. The second motor uses a servo motor, which has the advantages of fast response speed, high control precision, strong overload capacity, etc. In this case, parameters such as power, torque, speed, and encoder resolution need to be considered according to the actual production situation, so it is not limited. The output shaft of the second motor movably penetrates the chassis 25. Both the opening disk 33 and the three-jaw chuck 31 are fixedly sleeved on the penetrating end of the output shaft of the second motor. The center of the output shaft of the second motor is aligned with the centers of the opening disk 33 and the three-jaw chuck 31. A photoelectric sensor is installed on the penetrating end of the output shaft of the second motor. This sensor uses a direct irradiation type, and the light is irradiated on the photosensitive element through the hole positions of the opening disk 33. When the opening disk 33 rotates one week following the output shaft of the second motor, the number of times the photosensitive element receives light is equal to the number of openings on the disk, thereby calculating the speed. The photoelectric sensor is located inside the opening disk 33.

[0037] In order to further overcome the problems such as the wear and offset of the rotating shaft and the wear and distortion of the thread caused by the cutting force, the compensation part 4 of this case includes two linear motors 41. The two linear motors 41 are symmetrically installed on both sides of the slide table 21. L-shaped sliders 42 are installed on the moving ends of the two linear motors 41. A support plate 43 is fixedly connected between the two L-shaped sliders 42. A pressure sensor 44 is installed on the side of the support plate 43 close to the chassis 25. This sensor uses an STM32 microprocessor and is used to accurately measure the pressure value through the contact pressure. In this case, the pressure sensor 44 is electrically connected to the photoelectric sensor, and at the same time, the pressure sensor 44 is electrically connected to the two linear motors 41. A compensation plate 45 is installed on the pressure sensor 44. The compensation plate 45 is in contact with the chassis 25. The compensation part 4 further includes three compensation rods 46. The number of the compensation rods 46 is three and they are evenly distributed on the compensation plate 45. One ends of the three compensation rods 46 are fixedly connected to the compensation plate 45, and balls 47 are installed on the other ends of the three compensation rods 46. Each ball 47 is in contact with the inner wall of the circulation groove 32. The limiting ability of the three-jaw chuck 31 is formed by the compensation rods 46 and the balls 47, further overcoming the problems of the rotation shaft jitter and the three-jaw chuck 31 shaking caused by the long-term influence of the cutting force.

[0038] It should be noted that in order to prevent debris generated in the turning operation area from getting stuck in the gaps of equipment such as the threaded rod 24, the protection part 5 of this case includes two mounting plates 51. Both of the two mounting plates 51 are installed in the turning area of the lathe body 1. A protective cover 52 is installed on the side wall of one of the mounting plates 51. A winding roller 53 is rotatably connected between the two mounting plates 51. One end of the winding roller 53 movably penetrates into the protective cover 52. A torsion spring 54 is fixedly sleeved on the penetrating end of the winding roller 53. The torsion spring 54 is elastically connected between the inner wall of the protective cover 52 and the adjacent mounting plate 51. A steel belt 55 is wound around the winding roller 53. The elastic reset ability of the torsion spring 54 can always ensure the tension of the steel belt 55. The movable end of the steel belt 55 is fixedly connected to the outer wall of the chassis 25. The bottom of the steel belt 55 is attached to the top of the slide table 21. The steel belt 55 is made of thin steel material, which can be effectively wound and released. At the same time, the steel surface has a certain hardness and smoothness, avoiding the problem of collapse after unfolding and reducing the problem of adhesion of metal debris.

[0039] It should be noted that in order to further prevent the splashing of dropped metal debris, a baffle 6 is installed on the workbench in the turning area of the lathe body 1. Scrapers are integrally connected to both sides of the baffle 6. Both of the two scrapers are inclined and symmetrically arranged. The bottoms of the two scrapers are attached to the top of the steel belt 55. By using the winding and unfolding of the steel belt 55 passing through the scrapers, the metal debris can be automatically scraped off. An aggregate trough 7 is opened on the workbench in the turning area of the lathe body 1. The aggregate trough 7 is located below the movable end of the steel belt 55. The midline of the aggregate trough 7 is aligned with the midline of the baffle 6. The aggregate trough 7 is used to collect the scraped-off and dropped metal debris.

[0040] Working principle: According to the actual processing requirements, a suitable workpiece is placed in the three-jaw chuck 31 for clamping. By controlling the linear motor 41, the support plate 43 is driven to move to the side of the slide table 21 close to the first motor 23 to wait, without obstructing the moving path of the chassis 25. By controlling the first motor 23 to drive the threaded rod 24 to rotate, the slider slides along the inner wall of the chute 22, and then the chassis 25 is synchronously driven to move to a suitable processing position. The three-jaw chuck 31 is synchronously positioned in the turning area. A multi-axis control console for adjusting the tool is arranged in the lathe body 1. As Figure 7 shown, an accordion protective cover is arranged on its outside to protect key components from impurities such as chips, coolant, and dust. This component belongs to the prior art, and its tool can be configured with a robotic arm for collaborative operation to perform turning processing on the positioned workpiece. Therefore, this case will not be elaborated too much.

[0041] After the workpiece is positioned, the first motor 23 stops, and the position of the three-jaw chuck 31 is fixed. At this time, the support plate 43 is driven by the linear motor 41 to move closer to the chassis 25. After the compensation plate 45 contacts the chassis 25, the three compensation rods 46 drive the balls 47 into the circulation groove 32, and prompt the balls 47 to fit with the inner wall arc surface of the circulation groove 32 to form a triangular limit. In this limit state, when the three-jaw chuck 31 drives the workpiece to rotate, the balls 47 will always roll in the circulation groove 32, so as to overcome the wear caused by the cutting force to the three-jaw chuck 31 and the output shaft of the second motor through the compensation rods 46, ensuring the clamping stability and rotation stability of the three-jaw chuck 31 during long-term operation, and preventing the problem of deviation and shaking.

[0042] When the three-jaw chuck 31 rotates, the perforated disk 33 rotates accordingly. The rotation speed is automatically calculated by the number of times the holes on the perforated disk 33 pass through the photoelectric sensor. At high rotation speeds, the electrical signal of the photoelectric sensor prompts the pressure sensor 44 to be in the startup state. At this time, the contact pressure between the pressure sensor 44 and the chassis 25 through the compensation plate 45 is reset to 0. When the tool contacts the workpiece for cutting, this force is transmitted from the tool to the workpiece and then affects the output shaft of the second motor through the fixture. When the three-jaw chuck 31 is affected by this force, it will generate resistance to the output shaft of the second motor. The balls 47 are limited to roll synchronously in the circulation groove 32, so as to further overcome this resistance and correct the axial force of the output shaft of the second motor to the correct position, avoiding damage to the output shaft of the second motor during long-term cutting operations and thus causing problems of shaking and deviation, and at the same time ensuring the stability of the three-jaw chuck 31.

[0043] On the other hand, when cutting a larger or harder workpiece, as the cutting force increases, the resistance received by the three-jaw chuck 31, the output shaft of the second motor, and the chassis 25 also increases. At this time, the compensation plate 45 and the compensation rods 46 can sense the change in pressure, and thus autonomously drive the two linear motors 41 to work synchronously through electrical signals, drive the support plate 43 and push the compensation plate 45 to provide a force equal to and opposite to the resistance to pull the chassis 25, and at the same time the compensation rods 46 apply the same force to resist the three-jaw chuck 31, so as to compensate for the generated cutting force and prevent destructive damage to the output shaft of the second motor and the threaded rod 24 under the influence of the cutting force, thereby extending the service life.

[0044] The metal chips during the workpiece cutting process are picked up by the steel belt 55. During the subsequent adjustment of the chassis 25 driven by the slider on the sliding table 21, the steel belt 55 is wound and extended in real time by the torsion of the torsion spring 54, so as to prompt the metal chips carried on the surface of the steel belt 55 to be scraped off by the scraper into the aggregate tank 7, realizing the effect of automatically scraping off the residual chips during the material withdrawal and resetting and the material loading and positioning, improving the use convenience and reducing the pressure of manual cleaning.

[0045] It should be noted that in this text, relational terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variant thereof are intended to cover non-exclusive inclusion, such that a process, method, article or device comprising a series of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article or device. Without further limitation, an element defined by the statement "comprising an..." does not exclude the presence of additional identical elements in the process, method, article or device comprising the said element.

Claims

1. A rotary positioning machining device for a numerically controlled lathe, characterized in that, Including: Lathe body (1); Positioning part (2), installed inside the lathe body (1) for adjusting the machining position of the workpiece. The positioning part (2) includes a slide table (21) installed in the turning area of the lathe body (1), a chute (22) opened at the top of the slide table (21), a first motor (23) installed on the side wall of the slide table (21), a threaded rod (24) fixedly connected to the output shaft of the first motor (23), the end of the threaded rod (24) movably penetrates into the inside of the chute (22) and is rotatably connected to the inner wall of the chute (22), a slider is threadedly sleeved on the outer wall of the threaded rod (24), the slider is slidably connected to the inner wall of the chute (22), a chassis (25) is installed on the top of the slider, and the bottom of the outer wall of the chassis (25) is attached to the top of the slide table (21); Clamping part (3), installed on the positioning part (2) for clamping workpieces of different sizes; Compensation part (4), installed on the positioning part (2) for compensating the offset of the workpiece caused by the cutting force; Among them, the compensation part (4) includes two linear motors (41), the two linear motors (41) are symmetrically installed on both sides of the slide table (21), L-shaped sliders (42) are installed on the moving parts of the two linear motors (41), a support plate (43) is fixedly connected between the two L-shaped sliders (42), a pressure sensor (44) is installed on the side of the support plate (43) facing the clamping part (3), a compensation plate (45) is installed on the pressure sensor (44), and the compensation plate (45) is attached to the chassis (25); The compensation part (4) further includes compensation rods (46), the number of the compensation rods (46) is three and they are evenly distributed on the compensation plate (45), one ends of the three compensation rods (46) are fixedly connected to the compensation plate (45), the other ends of the three compensation rods (46) are all installed with balls (47), and each ball (47) is attached to the clamping part (3); Protection part (5), installed inside the lathe body (1) for preventing flying of falling debris; The protection part (5) includes two mounting plates (51), the two mounting plates (51) are both installed in the turning area of the lathe body (1), a protective cover (52) is installed on the side wall of one of the mounting plates (51), a winding roller (53) is rotatably connected between the two mounting plates (51), one end of the winding roller (53) movably penetrates into the protective cover (52), a torsion spring (54) is fixedly sleeved on the penetrating end of the winding roller (53), the torsion spring (54) is elastically connected between the inner wall of the protective cover (52) and the adjacent mounting plate (51), a steel belt (55) is wound on the winding roller (53), the movable end of the steel belt (55) is fixedly connected to the outer wall of the chassis (25), and the bottom of the steel belt (55) is attached to the top of the slide table (21); A baffle plate (6) is installed on the workbench in the turning area of the lathe body (1). Scrapers are integrally connected to both sides of the baffle plate (6). The two scrapers are both inclined and symmetrically arranged. The bottoms of the two scrapers are in contact with the top of the steel belt (55). An aggregate chute (7) is formed on the workbench in the turning area of the lathe body (1). The aggregate chute (7) is located below the movable end of the steel belt (55). The center line of the aggregate chute (7) is aligned with the center line of the baffle plate (6).

2. The rotary positioning machining device of a numerically controlled lathe according to claim 1, characterized in that: The clamping part (3) is arranged on the chassis (25). The clamping part (3) includes a three-jaw chuck (31). A circulating groove (32) that fits all the balls (47) is formed on the side of the three-jaw chuck (31) away from the jaws. The circulating groove (32) is of an annular structure and its inner wall is of an arc structure. An opening disk (33) is installed at the center on the side of the three-jaw chuck (31) away from the jaws.

3. The rotary positioning machining device of a numerically controlled lathe according to claim 2, characterized in that: A second motor is installed inside the chassis (25). The output shaft of the second motor passes through the chassis (25) movably. The opening disk (33) and the three-jaw chuck (31) are both fixedly sleeved on the penetrating end of the output shaft of the second motor. The center of the output shaft of the second motor is aligned with the centers of the opening disk (33) and the three-jaw chuck (31). A photoelectric sensor is installed on the penetrating end of the output shaft of the second motor. The photoelectric sensor is located inside the opening disk (33).

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