Numerical control flat turning disc with automatic tool changing mechanism

Abstract

This invention discloses a CNC rotary table with an automatic tool changer, belonging to the field of automatic tool changing. It includes a rotating disc body, a radially guided sliding block on the front surface of the disc body, a tool holder block connected to the sliding block, and a tool shank inclined to the direction of movement on the tool holder block, allowing the tool shank to rotate on the tool holder block. An axial limiting structure is provided on the tool shank and the tool holder block to restrict the axial movement of the tool shank relative to the tool holder block. At least two cutting inserts are fixedly connected to the end of the tool shank. A positioning structure is provided on the tool shank and the tool holder block, which restricts the rotation of the tool shank relative to the tool holder block around a first direction when the disc body rotates. A ratchet is provided on the tool shank, and a lever is provided at the non-machining movement end of the tool holder block on the disc body. The lever end has a pawl that engages with the ratchet, and the pawl drives the tool shank to rotate around a second direction via the ratchet. This structure enables automatic tool changing without any additional driving components, and the changed cutting inserts can simultaneously meet the requirements for boring and face boring.

Description

Technical Field

[0001] This invention relates to the field of automatic tool change, and more specifically to a CNC rotary table with an automatic tool change mechanism. Background Technology

[0002] In the field of CNC boring machines and special boring machine tools, the flat turntable, as the core execution component of radially adjustable boring, is widely used in the roughing and finishing processes of rotary workpieces, box-type and flange-type workpieces. It can be adapted to the integrated processing of coaxial boring and end face boring of workpieces.

[0003] Currently, a single-specification insert can simultaneously complete two forming processes: end face boring and inner hole boring. Specifically, it relies on the rotation of the flat rotary table to drive the insert to perform circumferential cutting motion, combined with the radial feed of the tool holder, to complete the machining and forming of hole diameter and end face dimensions, adapting to the integrated machining needs of standardized batch workpieces.

[0004] Due to multiple factors such as cutting impact, chip friction, and workpiece material hardness during boring, the wear rate of the carbide inserts at the end of the swivel tool holder is relatively fast. Under normal machining cutting parameters, the effective service life of the inserts is only 4-8 hours. After the cutting edge of the inserts wears, chips, and becomes dull, it will directly lead to the workpiece boring roundness, end face flatness, and surface roughness exceeding the standard, failing to meet the machining dimensional accuracy requirements. It is necessary to adjust the angle of the inserts in time or even disassemble and replace them to ensure the pass rate of the machined products.

[0005] Currently, under assembly line processing conditions, the maintenance methods after blade wear mainly fall into two categories: one is to only disassemble and replace the worn blade at the end of the tool holder, retaining the original tool holder installation reference; the other is to completely disassemble the external tool holder of the rotary table and replace it with a spare tool holder pre-installed with a good blade. The above two maintenance disassembly and assembly operations are simple and have low barriers to entry, requiring no modification to the rotary table structure. However, there are unavoidable production shortcomings: the disassembly and adjustment of blades and tool holders must be carried out by stopping the machine, and in some cases, even trial cutting and patching operations are required, further extending the equipment downtime, directly interrupting the continuous processing cycle of the assembly line, and significantly reducing machine tool uptime.

[0006] To overcome the constraints of manual tool changing and achieve uninterrupted automated tool changing on the rotary table, the existing automatic tool changing solutions in the industry are mainly divided into two mainstream structures: internal tool changing with a rotary tool head and external independent tool magazine. Both types of structures have compatibility defects and cannot meet the needs of boring and boring end face composite machining. They also suffer from common industry problems such as bulky structure, limited stroke, high cost, and poor stability.

[0007] Among these, the most widely used is the rotary tool changer structure. This structure integrates an independent rotating tool disc on the surface of the rotary table, relying on a drive motor to provide rotational power. It uses an axial telescopic locking cylinder and an end-face meshing gear plate to complete the rotational positioning and locking of the tool disc. By rotating and switching between different workpieces, it achieves automated replacement of worn tool inserts. This structure has several structural drawbacks: First, the integrated arrangement of the drive motor, telescopic cylinder, meshing gear plate, hydraulic lines, and control circuits directly occupies most of the installation space on the rotary table, compressing the tool holder and cutting clearance space. This results in a significant increase in the overall size and weight of the rotary table, a larger rotational cutting inertia, decreased dynamic stability in finishing, and a higher likelihood of cutting vibration marks. Second, the original radial transmission structure of the rotary table itself has a stroke limitation. The maximum radial movement distance of the original tool holder is less than the rotary table's own radius of rotation. Combined with the interference from the built-in tool disc and locking mechanism, the effective radial feed of the tool holder is further limited. The process is further reduced, significantly narrowing the range of machinable hole diameters and reducing the adaptability of the rotary cutting head; third, the structure has processing limitations, only able to complete boring by rotating the cutter head circumferentially and switching different cutting edges, which cannot be adapted to the end face boring process: in end face boring, since the cutting tools on the cutter head remain fixed, the extension position of the cutting tools after rotation will not change, and when making circumferential cutting along the end face of the workpiece, it is always the first cutting tool. Therefore, the rotary cutting head can only be adapted to the boring process and cannot meet the process requirement of using a single cutting tool for integrated machining of boring and end face boring in this condition.

[0008] Another existing technology is an external tool magazine-type automatic tool changer, which relies on an external robot arm and tool magazine on the machine tool to achieve fully automatic disassembly and replacement of the tool holder of the entire rotary table. Although this solution can achieve fully automated tool changing throughout the process, its drawbacks are more prominent: On the one hand, the external tool magazine, tool changing robot arm, linkage positioning mechanism, and servo control system have a high degree of integration, and the overall mechanical and electrical control structures are extremely complex, resulting in a significant increase in equipment modification, machine manufacturing, and subsequent maintenance costs, and an extremely low return on investment for small-batch, standardized workpiece processing scenarios; on the other hand, external tool changing requires reserving a large range of space for robot arm rotation and tool holder transfer, which places stringent requirements on the machine tool installation site and overall layout, making it unsuitable for compact boring machines and integrated rotary table modification scenarios.

[0009] In summary, the existing three types of technologies—manual tool changing with a rotary table, automatic tool changing with an internal tool head, and automatic tool changing with an external tool magazine and robotic arm—each have drawbacks such as long downtime, poor adaptability to complex machining, and high structural costs. Currently, there is no rotary table tool changing structure that is structurally simple, does not occupy the table space, can simultaneously adapt to integrated boring and boring end face machining, and offers low-cost automated tool changing. Therefore, it is difficult to meet the current needs of automated production lines for integrated boring machining.

[0010] In view of the problems existing in the prior art, the present invention designs and manufactures a CNC rotary table with an automatic tool changer to overcome the above defects. Summary of the Invention

[0011] To address the problems existing in the prior art, the present invention provides a CNC rotary table with an automatic tool changer, which can achieve automatic tool change without the aid of any additional driving components, and the tool after the tool change can simultaneously meet the machining requirements of boring and boring end face.

[0012] To achieve the above objectives, the technical solution adopted by the present invention is as follows: a CNC rotary table with an automatic tool changing mechanism, comprising a rotating disc body, a radially guided sliding slider on the front end surface of the disc body, a tool holder block connected to the slider, a tool bar inclined in the direction of movement on the tool holder block, and the tool bar being able to rotate on the tool holder block; The tool holder and the tool shank block are provided with an axial limiting structure, which can restrict the axial movement of the tool holder relative to the tool shank block. At least two blades are fixedly connected to the end of the blade bar. The blade bar and the handle block are provided with a positioning structure. When the disc rotates, the positioning structure can restrict the blade bar from rotating relative to the handle block around a first direction. The tool holder is equipped with a ratchet, and the non-machining movement direction end of the tool holder block on the disc body is equipped with a lever. The end of the lever is equipped with a pawl that can cooperate with the ratchet. When the slider drives the tool holder to move in the direction of the lever, the pawl drives the tool holder to rotate around the second direction through the ratchet.

[0013] Preferably, the front end face of the disc is provided with a radial guide groove, the slider slides in the radial guide groove, and the bottom of the slider is connected to the lead screw by a nut; The disc body is also provided with a mounting groove, and a driving device is provided in the mounting groove. The driving device is connected to the end of the lead screw through a transmission pair.

[0014] Preferably, the inclination angle of the tool holder is 45°-87°; Alternatively, the inclination angle of the tool holder is 80°; Alternatively, the inclination angle of the tool holder is 85°.

[0015] Preferably, the axial limiting structure includes a mating hole on the tool holder block, and the tool bar is provided with a mating section that is rotatably connected to the mating hole; The axial limiting structure also includes two limiting members. The two limiting members are disposed at both ends of the mating section and respectively cooperate with the end faces of the mating hole to restrict the axial movement of the tool bar. The mating section between the two limiting members can rotate in the mating hole.

[0016] Preferably, the two limiting members ensure that the axial clearance of the tool holder is no greater than 0.03 mm.

[0017] Preferably, one of the limiting members is a boss located at one end of the mating section, and the boss is integrally formed with the mating section; The other end of the mating section is provided with a threaded section, the diameter of which is smaller than the diameter of the tool shank in the mating hole; Another limiting component is a locking nut, which has at least one through locking hole on its outer side wall and a corresponding positioning hole on the threaded section. A locking pin is provided in the locking hole and extends into the positioning hole to fix the locking nut on the threaded section. Alternatively, another limiting component may be a limiting ring and a fastening nut. The other end of the mating section protrudes from the mating hole. A limiting platform is provided on the end face of the limiting ring near the mating hole. When the fastening nut and the platform cooperate to fasten the limiting ring to the end face of the other end of the mating section, the distance between the limiting platform and the adjacent end face of the mating hole is 0-0.03mm.

[0018] Preferably, the positioning structure includes a positioning groove disposed on the tool holder and an elastic positioning pin disposed on the tool shank block; The positioning groove is a non-obtuse angle groove, and one side of the positioning groove coincides with the radial line of the tool holder; The elastic positioning pin is a non-circular pin, and the shape of the front end of the elastic positioning pin matches the shape of the positioning groove.

[0019] Preferably, the upper end face of the slider is provided with an upper clearance groove, and the end of the blade bar away from the blade extends into the upper clearance groove; The ratchet is connected to the cutter bar in the upper clearance groove, and the slider is provided with a through groove parallel to the slider sliding direction, and the through groove is connected to the upper clearance groove. When the slider moves toward the lever, the lever can extend into the through groove, and the pawl at the end of the lever can cooperate with the ratchet on the tool holder to drive the tool holder to rotate.

[0020] Preferably, the tool holder is located at the end of the tool holder block away from the lever; And / or, the resilient locating pin is located at the end of the tool holder block away from the lever.

[0021] Preferably, the side wall of the mating section is provided with a lubricating oil channel, and the tool holder block is provided with an oil injection hole that communicates with the mating hole.

[0022] The advantages of this invention are: 1. The rotation of the tool holder in this invention drives multiple blades at the end of the tool holder to perform tool changing operations. The power supply is entirely based on the original lead screw and drive device that drives the radial sliding of the slider. There is no need to add independent external tool changing drive components such as servo motors, rotary cylinders, and gear motors. On the one hand, it greatly simplifies the layout of internal pipelines, circuits, and transmission components of the rotary table, reduces the overall size of the table, and lowers the production and assembly costs of the whole machine. On the other hand, it reduces the failure points of external drive components, reduces the difficulty of later maintenance of the equipment, improves the overall operational stability of the CNC rotary table, and is suitable for long-term use in harsh machining conditions.

[0023] 2. This invention limits the radial movement direction of the tool holder to an inclination angle of 45°-87°, preferably 80° or 85°. Relying on the characteristics of the inclined spatial layout, each rotation of the tool holder for tool changing can simultaneously change the three-dimensional spatial position and cutting point height of each end insert. When the rotary table performs internal boring and end face boring composite machining, only a single working insert is in contact with the workpiece cutting surface, while the remaining idle inserts are offset and avoid the workpiece machining path with the inclined tool holder. This completely eliminates the problem of idle inserts scraping the hole wall and workpiece end face, and improves the adaptability of composite machining after multi-insert rotation and tool changing.

[0024] 3. The ratchet and pawl are positioned at the non-machining movement end of the tool holder block and slide block to completely separate the tool change process from the boring and boring end face cutting positions. The tool change operation is only completed in the non-boring stroke of the rotary table. During the boring operation, the ratchet and pawl disengage, so that the tool change and machining positions do not interfere with each other, ensuring the efficiency of continuous automated machining operations of the rotary table.

[0025] 4. The axial limiting structure relies on the mating hole of the tool holder block and the mating section of the tool bar for assembly, and is equipped with two-way limiting parts at both ends for bidirectional limiting. Without restricting the tool bar's self-changing tool movement, it completely limits the axial movement and offset of the tool bar relative to the tool holder block, eliminates the axial displacement error of the tool bar during the boring process, accurately controls the cutting depth and flatness of the boring end face, and steadily improves the dimensional accuracy and form and position tolerance qualification rate of the workpiece end face.

[0026] 5. Detachable locking nut type limiting structure: Relying on the combination of an integrated boss and a locking nut for limiting, during assembly, the locking nut locking hole and the tool shank thread section positioning hole are aligned with the pre-set gap using a shim. After alignment, the shim is removed, and the locking nut is locked directly through the locking pin through the locking hole and positioning hole. It can accurately obtain a 0-0.03mm micron-level fit clearance between the limiting component and the end face of the mating hole. At the same time, the locking pin locking structure counteracts the cutting vibration of the machine tool, prevents the locking nut from rotating and loosening due to cutting vibration, and ensures that the axial limiting clearance is constant over a long period of time, making it suitable for high-precision machining conditions.

[0027] 6. Limiting ring + fastening nut combination limiting structure: The limiting ring is pressed by the continuous preload applied by the fastening nut, which inhibits the loosening of the limiting ring from the source. The axial movement clearance is maintained constant at 0-0.03mm through the fit between the integrated limiting platform of the limiting ring and the end face of the mating hole, which can take into account both the limiting accuracy and the disassembly and maintenance efficiency.

[0028] 7. Control the axial clearance of the tool holder to be no more than 0.03mm, and reserve a small amount of rotation clearance to prevent axial movement of the tool holder and avoid hard friction and seizing between the limiting part and the end face of the mating hole, thus ensuring smooth and jam-free self-changing of the tool holder.

[0029] 8. The non-obtuse angle positioning groove and the positioning structure in which one side of the positioning groove coincides with the radial line of the tool holder allow the elastic positioning pin to engage with the positioning groove when the rotating flat disc drives the tool holder to perform boring operations and the cutting insert is subjected to force. The side of the positioning groove that coincides with the radial line can limit the rotational offset of the tool holder relative to the tool holder block, lock the cutting angle of the tool holder, and eliminate the problem of the tool holder deflection caused by the boring resistance. This greatly improves the clamping rigidity of the tool holder under boring conditions and ensures that the cutting angle of the cutting insert is constant.

[0030] When the tool is changed, the pawl pushes the ratchet, and the elastic positioning pin is pushed open through the other side of the positioning groove to unlock the tool holder, thus achieving automatic switching between machining lock and tool change unlock.

[0031] 9. The ratchet is embedded in the upper clearance groove of the slider. The slider has a through groove parallel to the sliding direction to provide a linear guide for the tool change lever. The lever is fed in a directional manner along the through groove to ensure that the engagement angle between the end pawl and the ratchet is constant, avoiding off-center engagement, skipped teeth, and tooth disengagement failures. This improves the accuracy of the tool holder rotation tool change angle and ensures that the blade positioning angle is consistent for each tool change. The ratchet and pawl are all housed inside the clearance groove and through groove on the slider, and are located at the bottom of the protective belt of the flat rotating disc. The protective belt forms a closed protective cavity, which isolates cutting chips and workshop dust impurities from directly eroding the meshing tooth surface, reducing wear, corrosion and jamming of the ratchet and pawl teeth, and extending the service life of the tool changing transmission pair.

[0032] 10. A dedicated lubrication channel is provided in the tool holder mating section, and an oil injection hole is provided in the tool holder block. Lubricating grease can be easily added to the mating hole and the friction pair of the mating section to reduce the frictional resistance when the tool holder rotates around the second direction, reduce rotational wear, and ensure that the tool holder rotation and repositioning action is smooth and the angle is controllable. Lubricating grease can form a sealing oil film at the gap between the limit component and the end face of the mating hole, preventing external iron filings, dust and impurities from entering the tiny axial mating gap. This avoids hard impurities getting stuck in the gap, causing end face wear, gap enlargement and axial limit failure. It maintains the micron-level gap accuracy of the axial limit for a long time, ensuring that the long-term machining accuracy of the rotary table does not decrease and reducing the frequency of equipment accuracy calibration.

[0033] 11. The disc body has a built-in drive device, transmission pair and lead screw linkage. The slider relies on the radial guide groove and lead screw to achieve precise radial sliding. The slider sliding stroke and moving speed can be precisely controlled by the CNC system. It can accurately control the timing and stroke of the pawl and ratchet engagement. It is compatible with the programmed automatic tool changing logic of the CNC system. It can be connected to the CNC system linkage control to realize one-click automatic tool changing. It is suitable for use in fully automated CNC machining production lines and improves the level of machining intelligence. Attached Figure Description

[0034] Figure 1 This is a schematic diagram of a CNC rotary table with an automatic tool changer. Figure 2 A front view of a CNC rotary table with an automatic tool changer; Figure 3 This is a schematic diagram of a CNC rotary table with an automatic tool changer for removing protective strips and surrounding protective plates. Figure 4 A top view of a CNC rotary table with an automatic tool changer removing the protective strip; Figure 5 This is a schematic diagram of the tool changing mechanism of the present invention; Figure 6 This is a front view of the tool changing mechanism of the present invention; Figure 7 This is a top view of the tool changing mechanism of the present invention; Figure 8 This is a cross-sectional view along direction AA of Embodiment 1 of the tool changing mechanism of the present invention; Figure 9 This is a partial cross-sectional view of Embodiment 2 of the tool changing mechanism of the present invention; Figure 10 This is a schematic diagram of the tool changing mechanism of the present invention without the tool holder seat; Figure 11 This is a front view of the tool changing mechanism of the present invention without the tool holder. Figure 12 This is a side view of the tool changing mechanism of the present invention without the tool holder. Figure 13 This is a front view of the tool changing mechanism of the present invention without the slider; Figure 14 This is a schematic diagram of the tool changing mechanism of the present invention without the view of the bottom of the slider; Figure 15 This is a front view of the tool holder of the present invention; Figure 16 This is a schematic diagram of the tool holder of the present invention; Figure 17 This is a schematic diagram of the structure of the tool holder block of the present invention; Figure 18 This is a top view of the tool holder block of the present invention; Figure 19 This is a cross-sectional view of the tool holder block of the present invention along the BB direction; Figure 20 This is a cross-sectional view of the tool holder block of the present invention in the CC direction; Figure 21 This is a schematic diagram of the slider of the present invention; Figure 22 This is a top view of the slider of the present invention; Figure 23 This is a cross-sectional view of the slider in the DD direction of the present invention.

[0035] In the diagram: 1. Disc; 2. Slider; 3. Tool holder block; 4. Tool bar; 5. Blade; 6. Pressure plate; 7. Radial guide groove; 8. Lead screw; 9. Rotating seat; 10. Support plate; 11. Transmission pair; 12. Lever; 13. Ratchet; 14. Locking nut; 15. Locking hole; 16. Elastic positioning pin; 17. Pawl; 18. Drive device; 19. Limiting ring; 20. Fastening nut; 21. Upper clearance groove; 22. Through groove; 31. Mating hole; 32. Lower clearance groove; 33. Elastic positioning groove; 41. Boss; 42. Mating section; 43. Positioning groove; 44. Threaded section; 191. Limiting platform. Detailed Implementation

[0036] To facilitate understanding by those skilled in the art, the present invention will be further described below with reference to the accompanying drawings.

[0037] like Figures 1 to 23 As shown, a CNC rotary table with an automatic tool changer includes a rotating disc body 1, and a radially guided sliding slider 2 is provided on the front end face of the disc body 1. Specifically, a radial guide groove 7 is provided on the front end face of the disc body 1, and the slider 2 slides guided in the radial guide groove 7. The bottom of the slider 2 is connected to a lead screw 8 by a nut.

[0038] One end of the lead screw 8 is rotatably connected to the rotating seat 9, the rotating seat 9 is connected to the disc 1 at one end of the radial guide groove 7, and the other end of the lead screw 8 is rotatably connected to the support plate 10, the support plate 10 is connected to the disc 1 at the other end of the radial guide groove 7.

[0039] The disc body 1 is also provided with a mounting groove, which is specifically located at the bottom of the radial guide slide 7. The mounting groove and the radial guide slide 7 are parallel to each other, and the two are preferably arranged in layers so that the functional areas do not interfere with each other, making full use of the internal space of the disc body 1. The mounting groove is provided with a drive device 18, which is preferably a servo motor with a reducer. The drive device 18 is connected to the end of the lead screw 8 that passes through the support plate 10 through a transmission pair 11. The transmission pair 11 is preferably a gear pair, a pulley pair, or a synchronous pulley pair.

[0040] In this invention, a tool holder block 3 is connected to the slider 2. The tool holder block 3 is provided with a tool bar 4 inclined to the direction of movement. The tool bar 4 can rotate on the tool holder block 3. At least two blades 5 are fixedly connected to the end of the tool bar 4, preferably three or four blades 5, and preferably evenly distributed around the circumference. The reason for choosing the number of blades 5 is that during boring, the end of the tool bar 4 needs to extend into the hole to be machined. If there are too many blades 5, the diameter of the end of the tool bar 4 will increase, which will affect the end of the tool bar 4 from extending into the hole to be machined. Of course, a cutter disc can also be detachably connected to the end of the tool bar 4. At least two blades 5 are evenly distributed around the circumference of the cutter disc. The overall diameter of the cutter disc should also be considered to ensure that it can extend into the hole to be machined. The number of blades 5 is also preferably three or four.

[0041] like Figure 13 , Figure 14 As shown, the tool holder 4 is equipped with a ratchet 13. The number of teeth on the ratchet 13 is a multiple of the number of blades 5 at the end of the tool holder 4. A lever 12 is provided at the non-machining direction end of the tool holder block 3 on the disc body 1. This non-machining direction end is preferably close to the support plate 10. The lever 12 is fixed to the support plate 10. A pawl 17 is provided at the end of the lever 12, which can engage with the ratchet 13. When the slider 2 drives the tool holder 4 to move in the direction of the lever 12, the pawl 17 drives the tool holder 4 to rotate around the second direction via the ratchet 13. Positioning structures are provided on the tool holder 4 and the tool holder block 3. When the disc body 1 rotates, the positioning structures can restrict the rotation of the tool holder 4 relative to the tool holder block 3 around the first direction.

[0042] The above structure achieves tool changing by rotating the tool holder 4 to drive multiple blades 5 at the end of the tool holder 4. It relies entirely on the original lead screw 8 and drive device 18 that drive the radial sliding of the slider 2 to complete the power supply. There is no need to add independent external tool changing drive components such as servo motors, rotary cylinders, and gear motors. On the one hand, it greatly simplifies the layout of internal pipelines, circuits, and transmission components of the rotary table, reduces the overall volume of the table body 1, and reduces the production and assembly cost of the whole machine. On the other hand, it reduces the failure points of external drive components, reduces the difficulty of later maintenance of the equipment, improves the overall stability of the CNC rotary table, and is suitable for long-term use in harsh machining conditions.

[0043] The tilt angle A of the tool holder 4 in this invention is 45°-87°, such as... Figure 2 , Figure 6As shown, an angle of 80°-85° is preferred, and more specifically, 80° or 85° is preferred (too small an angle will affect the insertion of the end of the tool holder 4 into the hole to be machined. If the tilted tool holder 4 does not interfere with the hole to be machined, the tilt angle can be further reduced, but in principle, a large tilt angle should be used as much as possible). Relying on the tilted spatial layout characteristics of the tool holder 4, each rotation of the tool holder 4 can simultaneously change the three-dimensional spatial position and cutting point height of each end insert 5. When the flat rotary table performs internal boring and end face boring composite machining, only a single working insert 5 is in contact with the workpiece cutting surface, and the remaining idle inserts 5 are offset and avoid the workpiece machining path with the tilted tool holder 4. This completely eliminates the problem of idle inserts 5 scraping the hole wall and the end face of the workpiece, and improves the adaptability of composite machining after the rotation of multiple inserts 5.

[0044] Furthermore, the present invention arranges the ratchet 13 and pawl 17 in conjunction with the tool changing position at the non-machining movement end of the tool holder block 3 and the slider 2, so that the tool changing process of the tool holder 4 is completely separated from the boring and boring end face cutting positions. The tool changing operation is only completed in the non-boring stroke of the rotary table. During the boring operation, the ratchet 13 and pawl 17 disengage, so that the tool changing and machining positions do not interfere with each other, ensuring the efficiency of continuous automated machining operations of the rotary table.

[0045] The tool holder 4 and the tool shank block 3 of the present invention shall be provided with an axial limiting structure, which can restrict the axial movement of the tool holder 4 relative to the tool shank block 3.

[0046] like Figures 15 to 20 As shown, the axial limiting structure specifically includes a mating hole 31 located on the tool holder block 3, and a mating section 42 on the tool holder 4 rotatably connected to the mating hole 31. The axial limiting structure also includes two limiting members, which are respectively positioned at both ends of the mating section 42 and engage with the end faces of the mating hole 31 to restrict the axial movement of the tool holder 4. The mating section 42 between the two limiting members can rotate within the mating hole 31. By utilizing the two limiting members without constraining the tool holder 4's self-changing tool movement, the axial movement and offset of the tool holder 4 relative to the tool holder block 3 are completely restricted, eliminating the axial displacement error of the tool holder 4 during boring, accurately controlling the boring end face cutting depth and end face flatness, and steadily improving the workpiece end face machining dimensional accuracy and form and position tolerance pass rate.

[0047] Specifically, the two limiting components ensure that the axial clearance of the tool holder 4 is no more than 0.03mm, preferably 0.02mm. By reserving a small rotational clearance, axial movement of the tool holder 4 is prevented, and hard friction between the limiting components and the end face of the mating hole 31 is avoided, thus ensuring that the tool holder 4 can smoothly switch tools without jamming. Example

[0048] like Figure 8As shown, a limiting component is a boss 41 located at one end of the mating section 42. The boss 41 is integrally formed with the mating section 42. The side of the boss 41 near the mating section 42 needs to be ground, and the end faces of both ends of the mating hole 31 also need to be ground. The other end of the mating section 42 is provided with a threaded section 44. The diameter of the threaded section 44 is smaller than the diameter of the tool bar 4 in the mating hole 31. Another limiting component is a locking nut 14. The side of the locking nut 14 near the boss 41 needs to be ground. The outer wall of the locking nut 14 has at least one through locking hole 15, and the threaded section 44 has a corresponding positioning hole. The locking hole 15 has a locking pin that extends into the positioning hole, which can fix the locking nut 14 on the threaded section 44.

[0049] The specific clearance is controlled by pre-setting a clearance using shims during assembly. Ideally, the shims are placed between the end faces of the boss 41 and the mating hole 31. Then, the locking nut 14 is tightened against the other end face of the mating hole 31. The locking hole 15 of the locking nut 14 is aligned with the positioning hole of the threaded section 44 of the tool holder 4. After alignment, the shims are removed, and the locking nut 14 is rotated to a certain position. The locking pin then passes through the locking hole 15 and the positioning hole to lock the locking nut 14. This allows for precise acquisition of a 0-0.03mm micron-level clearance between the limiting component and the end face of the mating hole 31. A 0.02mm shim is preferred. Simultaneously, the locking pin structure counteracts machine tool cutting vibrations, preventing the locking nut 14 from rotating and loosening due to cutting vibrations, ensuring a long-term constant axial limiting clearance, and adapting to high-precision machining conditions. Example

[0050] like Figure 9 As shown, another limiting component is a limiting ring 19 and a fastening nut 20. The other end of the mating section 42 protrudes from the mating hole 31. A limiting platform 191 is provided on the end face of the limiting ring 19 near the mating hole 31. When the fastening nut 20 and the platform 41 cooperate to fasten the limiting ring 19 to the end face of the other end of the mating section 42, the distance between the limiting platform 191 and the end face of the adjacent mating hole 31 is 0-0.03mm. By continuously applying preload force with the fastening nut 20 to press the limiting ring 19, the loosening of the limiting ring 19 due to rotation is suppressed from the source. Through the cooperation between the integrated limiting platform 191 of the limiting ring 19 and the end face of the mating hole 31, a constant axial movement clearance of 0-0.03mm is maintained, which can take into account both limiting accuracy and disassembly and maintenance efficiency.

[0051] The positioning structure of this invention specifically includes a positioning groove 43 disposed on the tool holder 4 and an elastic positioning pin 16 disposed on the tool shank block 3, such as... Figures 10 to 12As shown, the positioning groove 43 is a non-obtuse angle groove. In this embodiment, the positioning groove 43 is a right angle groove. One side of the positioning groove 43 coincides with the radial line of the tool holder 4, which is convenient for processing and manufacturing. The elastic positioning pin 16 is a non-circular pin. It is elastically set in the elastic positioning groove 33 of the tool holder block 3. The rear end of the elastic positioning groove 33 is provided with a plug. The front end shape of the elastic positioning pin 16 matches the shape of the positioning groove 43.

[0052] The positioning structure, with a non-obtuse angle positioning groove 43 and one side of the positioning groove 43 coinciding with the radial line of the tool holder 4, allows the elastic positioning pin 16 to engage with the positioning groove 43 when the rotating planar disc drives the tool holder 4 to perform boring operations and the insert 5 is subjected to force. This, along with the side of the positioning groove 43 coinciding with the radial line, restricts the rotational offset of the tool holder 4 relative to the tool shank block 3, locks the cutting angle of the tool holder 4, and eliminates the problem of the tool holder 4 deflecting due to boring resistance. This significantly improves the clamping rigidity of the tool holder 4 under boring conditions and ensures a constant cutting angle for the insert 5. In summary, the above positioning structure can restrict the rotation of the tool holder 4 relative to the tool shank block 3 around the first direction.

[0053] When the tool is changed and force is applied, the pawl 17 pushes the ratchet 13 to drive the tool holder 4 to rotate in the second direction. At this time, the elastic positioning pin 16 is pushed open through the other side of the positioning groove 43 to unlock the rotation of the tool holder 4, thus realizing the automatic switching between machining lock and tool change unlock.

[0054] like Figures 21 to 23 As shown, the upper surface of the slider 2 of the present invention is provided with an upper clearance groove 21. The end of the blade 4 away from the blade 5 extends into the upper clearance groove 21. The ratchet 13 is connected to the blade 4 in the upper clearance groove 21. The slider 2 is provided with a through groove 22 parallel to the sliding direction of the slider 2. The end of the through groove 22 near the lever 12 is provided with a guide hole to facilitate the extension of the lever 12. The through groove 22 communicates with the upper clearance groove 21. When the slider 2 moves towards the lever 12, the lever 12 can extend into the through groove 22. The pawl 17 at the end of the lever 12 can cooperate with the ratchet 13 on the blade 4 to drive the blade 4 to rotate.

[0055] By embedding the ratchet 13 inside the upper clearance groove 21 of the slider 2, and opening a through groove 22 parallel to the sliding direction in the slider 2, a linear guide is provided for the tool change lever 12. The lever 12 is fed in a directional manner along the through groove 22, ensuring that the engagement angle between the end pawl 17 and the ratchet 13 is constant, avoiding off-center engagement, skipped teeth, and tooth disengagement failures, improving the accuracy of the tool holder 4 rotation tool change angle, and ensuring that the positioning angle of the blade 5 is uniform every time the tool is changed.

[0056] Of course, depending on the actual installation space, it may also be necessary to set a corresponding lower clearance groove 32 on the lower end face of the tool holder block 3 to facilitate the installation of related limiting components. Specifically, based on ensuring the structural strength of the tool holder block 3 itself, it can be reasonably set according to the relevant components of the tool holder 4.

[0057] The front end face of the chuck body on both sides of the radial guide groove 7 of the present invention is provided with a pressure plate 6. The pressure plate 6 can press on both sides of the groove opening of the radial guide groove 7. The pressure plate 6 can restrict the slider 2 from disengaging from the radial guide groove 7, thereby improving the stability of the slider 2 driving the tool holder 4 to move and process.

[0058] A chip-blocking groove is provided on the side of the pressure plate 6 near the other pressure plate 6. A protective belt is provided in the two chip-blocking grooves. The protective belt is specifically connected to both ends of the slider 2 and achieves synchronous follow-up by relying on the radial movement of the slider 2.

[0059] The above structure, through the precise cooperation of the chip-blocking groove and the protective belt, can effectively prevent iron chips and impurities generated during the machining process from entering the radial guide groove 7. This completely avoids damage to core precision components such as the guide surface of the radial guide groove 7, the lead screw 8, and the transmission pair 11 caused by iron chip jamming. It significantly reduces the probability of failures such as boring head movement jamming, positioning deviation, and transmission failure, ensuring the stability and accuracy of the mechanism operation under high-speed boring conditions. It also extends the service life of easily damaged precision components such as the lead screw 8, the slider 2, and the guide surface of the radial guide groove 7, and reduces the frequency of equipment maintenance and parts replacement.

[0060] Because the ratchet 13 and pawl 17 are all housed inside the clearance groove and through groove 22 on the slider 2, and are located at the bottom of the protective belt of the flat rotating disc, the protective belt forms a closed protective cavity, which isolates cutting chips and workshop dust impurities from directly eroding the meshing tooth surface, reducing the wear, corrosion and jamming problems of the tooth surface of the ratchet 13 and pawl 17, and extending the service life of the tool changing transmission pair 11.

[0061] In this invention, the tool holder 4 is specifically located at the end of the tool holder block 3 away from the lever 12. In this way, when the tool holder block 3 is close to the lever 12, the tool holder 4 will be located at the center of the disc body 1, thereby increasing the maximum machining radius of the blade 5 and thus increasing the maximum outer diameter of the boring end face.

[0062] The elastic positioning pin 16 is specifically located at the end of the tool holder block 3 away from the lever 12. This position is convenient for machining and will not interfere with other transmission structures.

[0063] The mating section 42 is preferably provided with a lubricating oil channel on its side wall, and the tool holder block 3 is provided with an oil injection hole that communicates with the mating hole 31. This structure allows for convenient lubrication of the friction pair of the mating hole 31 and the mating section 42, reducing the frictional resistance when the tool holder 4 rotates around the second direction, reducing self-rotation wear, and ensuring that the rotation and repositioning of the tool holder 4 is smooth and the angle is controllable.

[0064] Moreover, the lubricating grease can form a sealing oil film at the gap between the limit component and the end face of the mating hole 31, preventing external iron filings, dust, and impurities from entering the tiny axial mating gap. This avoids hard impurities getting stuck in the gap, causing end face wear, gap enlargement, and axial limit failure. It maintains the micron-level gap accuracy of the axial limit for a long time, ensuring that the long-term machining accuracy of the rotary table does not decrease and reducing the frequency of equipment accuracy calibration.

[0065] The specific tool changing process of this invention is as follows: The slider 2 drives the tool holder block 3 to perform boring and end face machining using a machining insert 5 in the machining direction. When the machining insert 5 needs to be replaced, the slider 2 moves to the non-machining direction until the ratchet 13 on the tool holder 4 engages with the pawl 17 at the end of the lever 12. At this time, the tool holder 4 rotates, and the position of the insert 5 changes. The specific number of engagements between the ratchet 13 and the pawl 17 is reasonably set according to the number of inserts 5 and the number of teeth on the ratchet 13, but it must be ensured that the number of inserts 5 and the number of teeth on the ratchet are in a multiple relationship, until the new insert 5 rotates to the machining position. The entire tool changing action is powered entirely by the original lead screw 8 that drives the slider 2 to slide radially and the drive device 18.

[0066] The disc body 1 of this invention has a built-in drive device 18, a transmission pair 11 and a lead screw 8 linked together. The slider 2 achieves precise radial sliding by relying on the radial guide groove 7 and the lead screw 8. The sliding stroke and moving speed of the slider 2 can be precisely controlled by the CNC system. It can accurately control the engagement time and engagement stroke of the pawl 17 and the ratchet 13. It is compatible with the programmed automatic tool changing logic of the CNC system and can be connected to the CNC system for linkage control to realize one-click automatic tool changing. It is suitable for use in fully automated CNC machining production lines and improves the level of intelligent processing.

[0067] It should be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of protection of the invention. Furthermore, it should be understood that after reading the technical description of this invention, those skilled in the art can make various alterations, modifications, and / or variations to the invention, and all such equivalent forms also fall within the scope of protection defined by the appended claims.

Claims

1. A CNC rotary table with an automatic tool changer, characterized in that, The device includes a rotating disc (1), a radially guided sliding block (2) on the front end surface of the disc (1), a tool holder block (3) connected to the slider (2), a tool bar (4) inclined to the direction of movement on the tool holder block (3), and the tool bar (4) being able to rotate on the tool holder block (3). The tool bar (4) and the tool holder block (3) are provided with an axial limiting structure, which can restrict the axial movement of the tool bar (4) relative to the tool holder block (3); At least two blades (5) are fixedly connected to the end of the blade bar (4). The blade bar (4) and the handle block (3) are provided with positioning structures. When the disc body (1) rotates, the positioning structures can restrict the blade bar (4) from rotating relative to the handle block (3) around the first direction. The tool holder (4) is provided with a ratchet (13), and the non-machining movement direction end of the tool holder block (3) on the disc body (1) is provided with a lever (12). The end of the lever (12) is provided with a pawl (17) that can cooperate with the ratchet (13). When the slider (2) drives the tool holder (4) to move in the direction of the lever (12), the pawl (17) drives the tool holder (4) to rotate around the second direction through the ratchet (13).

2. A CNC rotary table with an automatic tool changer according to claim 1, characterized in that, The front end face of the disc body (1) is provided with a radial guide groove (7), the slider (2) slides in the radial guide groove (7), and the bottom of the slider (2) is connected to the lead screw (8) by a nut; The disc body (1) is also provided with an installation groove, and a drive device (18) is provided in the installation groove. The drive device (18) is connected to the end of the lead screw (8) through a transmission pair (11).

3. A CNC rotary table with an automatic tool changer according to claim 1, characterized in that, The inclination angle of the tool holder (4) is 45°-87°; Alternatively, the inclination angle of the tool holder (4) is 80°; Alternatively, the inclination angle of the tool holder (4) is 85°.

4. A CNC rotary table with an automatic tool changer according to claim 1, characterized in that, The axial limiting structure includes a mating hole (31) on the tool holder block (3), and the tool bar (4) is provided with a mating section (42) that is rotatably connected to the mating hole (31); The axial limiting structure also includes two limiting members. The two limiting members are disposed at both ends of the mating section (42) and respectively cooperate with the end faces of the mating hole (31) to restrict the axial movement of the tool bar (4). The mating section (42) between the two limiting members can rotate in the mating hole (31).

5. A CNC rotary table with an automatic tool changer according to claim 4, characterized in that, The two limiting members ensure that the axial clearance of the tool holder (4) is no greater than 0.03 mm.

6. A CNC rotary table with an automatic tool changer according to claim 5, characterized in that, The limiting member is configured as a boss (41) located at one end of the mating section (42), and the boss (41) is integrally formed with the mating section (42); The other end of the mating section (42) is provided with a threaded section (44), the diameter of which is smaller than the diameter of the tool bar (4) in the mating hole (31); Another limiting member is a locking nut (14), which has at least one through locking hole (15) on its outer side wall. The locking hole (15) is provided with a locking pin that can fix the locking nut (14) on the threaded section (44). Alternatively, another limiting component may be a limiting ring (19) and a fastening nut (20). The other end of the mating section (42) protrudes from the mating hole (31). A limiting platform (191) is provided on the end face of the limiting ring (19) near the mating hole (31). When the fastening nut (20) and the platform (41) work together to fasten the limiting ring (19) to the end face of the other end of the mating section (42), the distance between the limiting platform (191) and the end face of the adjacent mating hole (31) is 0-0.03 mm.

7. A CNC rotary table with an automatic tool changer according to claim 1, characterized in that, The positioning structure includes a positioning groove (43) provided on the tool holder (4) and an elastic positioning pin (16) provided on the tool holder block (3). The positioning groove (43) is a non-obtuse angle groove, and one side of the positioning groove (43) coincides with the radial line of the tool holder (4); The elastic positioning pin (16) is a non-circular pin, and the shape of the front end of the elastic positioning pin (16) matches the shape of the positioning groove (43).

8. A CNC rotary table with an automatic tool changer according to claim 1, characterized in that, The upper end face of the slider (2) is provided with an upper clearance groove (21), and the end of the knife bar (4) away from the blade (5) extends into the upper clearance groove (21); The ratchet (13) is connected to the cutter bar (4) in the upper clearance groove (21), and the slider (2) is provided with a through groove (22) parallel to the sliding direction of the slider (2), and the through groove (22) is connected to the upper clearance groove (21). When the slider (2) moves toward the lever (12), the lever (12) can extend into the through groove (22), and the pawl (17) at the end of the lever (12) can cooperate with the ratchet (13) on the tool bar (4) to drive the tool bar (4) to rotate.

9. A CNC rotary table with an automatic tool changer according to claim 1, characterized in that, The tool holder (4) is located at the end of the tool holder block (3) away from the lever (12); And / or, the elastic positioning pin (16) is located at the end of the handle block (3) away from the lever (12).

10. A CNC rotary table with an automatic tool changer according to claim 4, characterized in that, The side wall (42) of the mating section is provided with a lubricating oil channel, and the tool holder block (3) is provided with an oil injection hole that communicates with the mating hole (31).

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