Zero point positioning rotary table and table changing control method

Abstract

The invention discloses a zero-point positioning rotary table and a table changing control method, and belongs to the technical field of common functional parts of machine tools. The rotary table comprises a sliding seat, a direct-drive motor, a positioning disc, a brake mechanism, a zero-point positioning mechanism and a working table, the direct-drive motor is installed in the sliding seat, a mandrel is arranged in the direct-drive motor, a grating ruler is arranged outside the mandrel, the positioning disc is arranged on the direct-drive motor and can drive the direct-drive motor to rotate, and the zero-point positioning mechanism is arranged on the working table. The brake mechanism is installed on the sliding seat and can lock the positioning disc, and the workbench is detachably connected with the positioning disc through the zero point positioning mechanism. The device further comprises an oil path and a plurality of gas paths, and the oil path and the gas paths are integrated on the mandrel and extend to the zero point positioning mechanism. According to the invention, the zero point positioning system is deeply integrated on the rotary table, and the functions of blowing cleaning and air tightness detection are carried, so that higher-level structure integration is realized; and through cooperative operation of the direct-drive motor and the clamping mechanism, the workpiece clamping precision and reliability are remarkably improved.

Description

Technical Field

[0001] This invention relates to a zero-point positioning rotary table and a table-changing control method, belonging to the technical field of commonly used functional components of machine tools. Background Technology

[0002] The rotary table enables machine tools to perform precision machining operations such as milling, drilling, reaming, boring, and reaming on all sides of the workpiece in a single setup by achieving workpiece rotation indexing and multi-axis linkage. It is a core functional component for improving machining efficiency and the machining accuracy of complex parts. However, traditional horizontal machining centers often suffer from low automation in workpiece positioning and clamping, susceptibility to hydraulic system pressure fluctuations, poor engagement of clamping components, and workpiece loosening during high-speed rotation or high-cutting-force machining. The clamping mechanism is complex, allowing chips and impurities to easily enter, making cleaning and maintenance inconvenient. Workpiece alignment is heavily influenced by the operator's experience, requiring the setting of locating pin holes and tapping of the workpiece during alignment, resulting in low efficiency and reliability. Some clamping elements wear out quickly and require frequent replacement; after long-term use, key components of the clamping mechanism, such as the elastomer, experience performance degradation due to fatigue and wear, increasing maintenance costs and downtime.

[0003] Existing zero-point positioning rotary table technologies, such as the Chinese invention patent application No. 202210585662.4, disclose a rotary worktable based on zero-point positioning and its application. This technology uses two motors and a reducer gear transmission, requiring a lifting device and guide rails to complete the table-changing action. The locking mechanism uses claws to grip pull studs and is hydraulically driven. However, the locking mechanism lacks clamping and loosening monitoring, posing certain safety hazards, and its integration level is low, making it suitable for standalone operation. This invention, on the other hand, uses a direct-drive motor, resulting in a simple transmission chain structure. It also incorporates monitoring of the blowing cleaning and clamping mechanism status, leading to better integration of the rotary worktable. The table-changing action does not require a lifting mechanism and guide rails; a robotic arm can be used to perform the action. The clamping mechanism uses the latest locking block clamping method, resulting in higher clamping accuracy, better clamping effect, and easier disassembly and maintenance. For example, Chinese invention patent application No. 201910820268.2 discloses a high-precision flexible zero-point positioning system and reveals the mechanical structure design of a clamping mechanism. The clamping mechanism structure is only used to illustrate the action implementation. However, this invention discloses the integrated use of the zero-point positioning system on a rotary table. Furthermore, the zero-point positioning system disclosed in this invention is equipped with airtightness detection and air blowing cleaning functions, which can realize the status monitoring of the clamping mechanism and facilitate the construction of automated production lines. Summary of the Invention

[0004] (a) Technical problems to be solved The technical problem to be solved by this invention is to address the problems of existing turntables, such as excessively high overall size, messy pipeline layout, inconvenient maintenance and repair, low system integration, and difficulty in integrating into the flexible manufacturing system of the production line due to unreasonable layout of the clamping mechanism and internal mechanical transmission structure.

[0005] (II) Technical Solution To address the aforementioned technical problems, this invention provides a zero-point positioning turntable, comprising a slide, a direct-drive motor, a positioning disk, a braking mechanism, a zero-point positioning mechanism, and a worktable. The direct-drive motor is installed within the slide, and a mandrel is internally mounted on the motor. A linear encoder is externally mounted on the mandrel. The positioning disk is mounted on the direct-drive motor and can rotate. The braking mechanism is mounted on the slide and can lock the positioning disk. The worktable is detachably connected to the positioning disk via the zero-point positioning mechanism. The direct-drive motor drives the positioning disk, the zero-point positioning mechanism, and the worktable assembly to rotate. After the rotation angle is detected by the linear encoder and reaches the correct position, the braking mechanism clamps the positioning disk, completing the workpiece processing step. This cyclical operation fulfills the requirement for multi-angle rotation processing of the workpiece.

[0006] The aforementioned turntable also includes an oil circuit and multiple air circuits. The oil circuit and air circuits are integrated on the spindle and extend to the zero-point positioning mechanism. The oil circuit controls the zero-point positioning mechanism to loosen and tighten the worktable, and the multiple air circuits clean and inspect the zero-point positioning mechanism respectively. The inspection includes detecting the clamping state of the worktable, detecting the loosening state, and detecting the installation in place.

[0007] This rotary table features zero-point positioning, and the zero-point positioning system has multi-channel air blowing cleaning and air tightness detection functions. The air inlets are all centrally located on the oil passage shaft. While ensuring the functionality, the machine has good integration, is easy to maintain, and has good human-machine interaction.

[0008] Furthermore, the mandrel is fixedly mounted, and its upper end is provided with multiple annular grooves. Multiple first passages are provided inside the mandrel, one end of which communicates with one of the annular grooves, and the other end of which passes through the mandrel. A rotatable bushing is mounted on the mandrel, and a positioning disc is mounted on the bushing. Multiple second passages are provided on the bushing, one end of which communicates with one of the annular grooves on the mandrel, and the other end of which passes through the bushing and enters the zero-point positioning mechanism. The first passages, annular grooves, and second passages are connected to form the oil or air passage. This structural arrangement ensures that even when the mandrel is fixed and the positioning disc rotates, the oil and air passages remain unobstructed.

[0009] Furthermore, the air path includes a clamping air path, a releasing air path, a cleaning air path, and a positioning detection air path. The clamping air path is used to detect whether the zero-point positioning mechanism is clamping the worktable, i.e., to detect whether the clamping is complete. The releasing air path is used to detect whether the zero-point positioning mechanism is releasing the worktable, i.e., to detect whether the worktable is in a detachable state. The cleaning air path is used to blow air to clean the zero-point positioning mechanism and remove any debris that may have entered. The positioning detection air path is used to detect whether the worktable surface is installed in place. Furthermore, the positioning plate is equipped with a clamping air inlet, a clamping air outlet, a releasing air inlet, a releasing air outlet, a cleaning / detection dual-purpose hole, and an oil inlet. The clamping air path is sequentially connected to the clamping air inlet and the clamping air outlet, and the releasing air path is sequentially connected to the releasing air inlet and the releasing air outlet. Pressure feedback devices are respectively installed on the clamping air outlet and the releasing air outlet. When the zero-point positioning mechanism clamps the worktable, it blocks the airflow in the clamping and releasing air paths. When the zero-point positioning mechanism releases the worktable, it opens (or connects) the airflow in the clamping and releasing air paths. By detecting changes in air pressure, it determines whether the worktable positioning is accurate, ensuring that there is no gap error in clamping. The cleaning air path and the positioning detection air path are respectively connected to the cleaning / detection dual-purpose hole, and the oil path is connected to the oil inlet.

[0010] Furthermore, the clamping air path, the releasing air path, the cleaning air path, and the positioning detection air path are all connected to the same air source, which provides a 5 bar pressure airflow. The releasing air path and the positioning detection air path are each equipped with a pressure regulating valve and a pressure gauge, and the pressure regulating valve provides a 2 bar pressure airflow to both of them.

[0011] Furthermore, the zero-point positioning mechanism includes a clamping assembly mounted on the positioning plate and a positioning pin mounted on the worktable, which can be detachably connected. The clamping assembly includes a base, a piston, a clamping ball, and a clamping spring. The piston is slidably mounted in the base, and a locking groove is provided in the middle of the piston. A piston ball cage is provided in the locking groove, and a clamping ball is placed in the piston ball cage. A clamping groove is provided around the locking groove on the piston, and a clamping spring is placed in the clamping groove. A positioning cone surface is provided on the positioning pin, and an oil inlet channel is provided on the base. When released, hydraulic oil enters through the oil inlet channel, pushing the piston upward, overcoming the spring force, and the clamping ball enters the piston ball cage, releasing the positioning pin. When clamped, the clamping spring uses its spring force to push the piston downward, and hydraulic oil is discharged through the oil inlet channel. Due to space constraints, the clamping ball cannot fall and is stuck on the upper edge of the piston ball cage, locking the positioning pin. Zero-point positioning is achieved through the above structure. To address the safety risks associated with traditional rotary table systems that utilize hydraulic clamping and release systems, including potential hazards such as hydraulic leakage and pressure runaway, this invention employs a hydraulic release and mechanical clamping mechanism. This ensures that the clamping and release drive is safe and controllable, eliminating potential safety risks.

[0012] Furthermore, the positioning plate is provided with a mother plate, and the mother plate is provided with multiple sets of clamping components. The worktable is provided with a number of positioning pins equal to the number of clamping components. The clamping components include angular positioning clamping components, center positioning clamping components, and general clamping components. The positioning pins on the worktable include angular positioning pins, center positioning pins, and general positioning pins that correspond one-to-one with the clamping components on the mother plate. The connections are one-to-one, which can effectively avoid the process of manual alignment after the workpiece is re-clamped and realize the automatic zeroing function of the workpiece.

[0013] Furthermore, the base is provided with two detection air paths, one connected to the clamping air path and the other to the releasing air path. A control valve is installed on each detection air path. The control valve's switch abuts against a piston, and the piston's up-and-down movement opens or closes the control valve. When the clamping assembly is in the clamping state, the piston moves downwards, the valve is in the open state, and the air path is blocked. When the clamping assembly is in the releasing state, the piston moves upwards, the valve is in the open state, and the air path is connected, allowing the clamping state of the clamping mechanism to be detected by air pressure. The upper circumferential surface of the base of the clamping mechanism is provided with multiple airtightness detection holes, and the inner wall of the locking groove is provided with cleaning air holes. The airtightness detection holes and cleaning air holes are respectively connected to a dual-purpose cleaning and detection hole. The airtightness detection holes can be used to check whether the worktable is in place based on air pressure. In addition, the airtightness detection holes can also function as surrounding cleaning air holes, cooperating with the central cleaning air hole on the inner wall of the locking groove, effectively preventing iron filings from entering during table changes.

[0014] Furthermore, the slide block is equipped with multiple symmetrically arranged braking mechanisms. Each braking mechanism includes a brake seat, a brake slider, brake pads, and brake oil passages. The brake seat is mounted on the slide block, and the brake slider is slidably connected to the brake seat. The brake oil passages are located between the brake slider and the brake seat, controlling the up-and-down movement of the brake slider by the inflow and outflow of hydraulic oil. The brake pads are located at the upper end of the brake slider and are used to lock the positioning disc. The braking mechanisms are symmetrically arranged in four directions on the circumference, enabling rapid and stable braking of the turntable.

[0015] On the other hand, the present invention also provides a turntable switching control method, which uses the zero-point positioning turntable described above, and includes the following steps: S1. Control the zero-point positioning mechanism to release the worktable. The air circuit detects that the zero-point positioning mechanism is in the released state. Manually or with a robot arm, lift the old worktable. S2, Air passage ventilation and air blowing cleaning zero-point positioning mechanism; S3. Move the new workbench; S4. The zero-point positioning mechanism mechanically locks the new worktable, and the air circuit detects that the zero-point positioning mechanism is in a clamping state and that the new worktable is installed in place. S5. Control the direct drive motor to drive the positioning plate, rotate the worktable to the required angle of the workpiece to be processed, and control the brake mechanism to lock the positioning plate until the processing step is completed. S6. Control the brake mechanism to release the positioning plate, and the worktable rotates to the next process, completing the processing of all sides of the workpiece in a cycle.

[0016] (III) Beneficial Effects The above-described technical solution of the present invention has the following advantages: (1) This invention innovatively adopts a centralized arrangement scheme for air and hydraulic circuits, successfully breaking through the technical bottleneck of "tall size and messy pipelines" in traditional rotary table machining fixtures, greatly reducing the difficulty of equipment maintenance and significantly improving the convenience of maintenance. In terms of structural design, it achieves a high degree of integration, effectively reducing the overall height of the rotary table and improving human-machine interaction.

[0017] (2) This invention integrates multiple automated functional modules such as hydraulic release, mechanical clamping, air tightness detection and center air blowing cleaning. The components work together to significantly improve work efficiency and processing stability, and are highly compatible with modern mechanized production lines.

[0018] (3) The rotary table of this invention can achieve automatic zeroing function after the workpiece is clamped once through the zero-point positioning system. The rotary table with zero-point positioning function developed adopts multiple sets of precision clamping mechanisms to work together, and with the direct drive motor drive system and the grating ruler closed-loop angle detection device, a highly efficient and reliable positioning system is constructed. Through precise motion control and real-time angle feedback, the positioning accuracy of the equipment is effectively improved, meeting the needs of high-precision processing scenarios. It overcomes the problem that existing worktables require repeated screw replacement and pad adjustment operations during the clamping process, resulting in cumbersome processes and long clamping cycles, which cannot meet the needs of automated and efficient production modes, and achieves precise and rapid positioning and clamping.

[0019] This invention optimizes the turntable clamping mechanism to improve system stability and reliability.

[0020] This invention achieves miniaturization, modularization, and standardization of the turntable by directly driving it with a motor and optimizing its structural design and spatial layout, thereby improving its adaptability to engineering applications.

[0021] In addition to the technical problems solved by the present invention, the technical features of the technical solutions constituted by the present invention, and the advantages brought about by the technical features of these technical solutions as described above, other technical features of the present invention and the advantages brought about by these technical features will be further explained in conjunction with the accompanying drawings. Attached Figure Description

[0022] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0023] Figure 1 This is a schematic cross-sectional view of the present invention.

[0024] Figure 2 This is an isometric view of the worktable hidden in this invention.

[0025] Figure 3 This is an enlarged schematic diagram of the mounting portion of the brake mechanism of the present invention.

[0026] Figure 4 This is a schematic diagram of the workbench and zero-point positioning mechanism of the present invention.

[0027] Figure 5 This is a schematic diagram of the clamping assembly of the present invention being released.

[0028] Figure 6 This is a schematic diagram of the clamping assembly of the present invention.

[0029] Figure 7 This is a schematic diagram of the installation of the positioning pin of the present invention.

[0030] Figure 8 This is a schematic diagram of the gas path principle of the present invention.

[0031] Figure 9 This is a schematic diagram of the pipe hole arrangement of the zero-point positioning mechanism of the present invention.

[0032] Figure 10 This is a schematic diagram of the clamping / releasing detection air path of the clamping mechanism of the present invention.

[0033] Figure 11 This is a schematic diagram of the cleaning air blowing and positioning detection of the clamping mechanism of the present invention.

[0034] Figure 12 This is a schematic diagram of the process of the present invention.

[0035] In the diagram: 1. Slide; 2. Direct drive motor; 3. Positioning plate; 4. Braking mechanism; 5. Worktable; 6. Mandrel; 7. Grating ruler; 8. Annular groove; 9. First passage; 10. Bushing; 11. Second passage; 12. Clamping air passage; 13. Loosening air passage; 14. Cleaning air passage; 15. Position detection air passage; 16. Clamping air inlet; 17. Clamping air outlet; 18. Loosening air inlet; 19. Loosening air outlet; 20. Cleaning and detection dual-purpose hole; 21. Oil inlet; 22. Pressure feedback device; 23. Pressure regulating valve; 24. Pressure gauge; 25. Clamping assembly; 26. Positioning pin; 27. 1. Base; 28. Piston; 29. ​​Clamping ball; 30. Clamping spring; 31. Locking groove; 32. Positioning cone surface; 33. Oil inlet channel; 34. Mother plate; 35. Angular positioning clamping assembly; 36. Center positioning clamping assembly; 37. Universal clamping assembly; 38. Angular positioning pin; 39. Center positioning pin; 40. Universal positioning pin; 41. Detection air passage; 42. Control valve; 43. Air tightness detection hole; 44. Cleaning air blowing hole; 45. Brake seat; 46. Brake slider; 47. Brake pad; 48. Brake oil passage; 49. Screw; 50. Limit sleeve; 51. Floating spring. Detailed Implementation

[0036] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0037] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0038] Example 1, as Figure 1-3As shown, a zero-point positioning turntable includes a slide 1, a direct-drive motor 2, a positioning disk 3, a braking mechanism 4, a zero-point positioning mechanism, and a worktable 5. The direct-drive motor 2 is installed inside the slide 1. The direct-drive motor 2 typically includes a stator at the lower end and a rotor at the upper end. A spindle 6 is provided inside the direct-drive motor 2, and a grating ruler 7 is provided outside the spindle 6. The positioning disk 3 is provided on the rotor of the direct-drive motor 2 and can drive the positioning disk 3 to rotate. The braking mechanism 4 is installed on the slide 1 and can lock the positioning disk 3. The worktable 5 is detachably connected to the positioning disk 3 through the zero-point positioning mechanism. The turntable structure provided in this embodiment also includes an oil circuit and four air circuits. The oil circuit and air circuits are integrated on the spindle 6 and extend to the zero-point positioning mechanism. The oil circuit controls the zero-point positioning mechanism to loosen and tighten the worktable 5, and the multiple air circuits clean and inspect the zero-point positioning mechanism. The inspection includes the zero-point positioning mechanism clamping state detection, loosening state detection, and table surface installation position detection.

[0039] Since the mandrel 6 is fixed and the positioning disk 3 rotates, the oil and air passages need to be concentrated on the mandrel 6 and connected to the zero-point positioning mechanism on the positioning disk 3. Therefore, a method for arranging the oil and air passages is provided here. Specifically: the mandrel 6 is fixedly set, and its upper end is provided with multiple annular grooves 8. A sealing ring is usually provided between adjacent annular grooves 8. Multiple first passages 9 are provided inside the mandrel 6. The first passages 9 can be arranged circumferentially along the mandrel 6. One end of each first passage 9 communicates with one of the annular grooves 8, and the other end passes through the mandrel 6. A rotatable bushing 10 is provided on the mandrel 6. The positioning disk 3 is mounted on the bushing 10. Multiple second passages 11 are provided on the bushing 10. One end of each second passage 11 communicates with one of the annular grooves 8 on the mandrel 6, and the other end passes through the bushing 10 and enters the zero-point positioning mechanism. Different first passages 9 correspond one-to-one with different annular grooves 8, and different second passages 11 correspond one-to-one with different annular grooves 8 (or different first passages 9). The first passage 9, annular grooves 8 and second passages 11 are connected to form the oil passage or gas passage.

[0040] Example 2 is an example of further optimizing the oil and gas circuit structures based on Example 1. In this example, as... Figure 8 As shown, the air path includes a clamping air path 12, a releasing air path 13, a cleaning air path 14, and a positioning detection air path 15. The clamping air path 12 is used to detect whether the zero-point positioning mechanism clamps the worktable 5; the releasing air path 13 is used to detect whether the zero-point positioning mechanism releases the worktable 5; the cleaning air path 14 is used to blow air to clean the zero-point positioning mechanism; and the positioning detection air path 15 is used to detect whether the worktable 5 is properly installed. The specific detection method is as follows: the positioning plate 3 is provided with a clamping air inlet 16, a clamping air outlet 17, a releasing air inlet 18, a releasing air outlet 19, a cleaning and detection dual-purpose hole 20, and an oil inlet 21, as shown... Figure 9 As shown, the clamping air passage 12 is connected to the clamping air inlet 16 and the clamping air outlet 17 in sequence, and the releasing air passage 13 is connected to the releasing air inlet 18 and the releasing air outlet 19 in sequence. These two passages form two independent airflow detection channels (sometimes only one channel may be used). Pressure feedback devices 22 (such as pressure sensors) are respectively installed on the clamping air outlet 17 and the releasing air outlet 19, and both are connected to the external atmospheric environment (or, pressure feedback devices 22 are installed on the paths connecting the clamping air outlet 17 and the releasing air outlet 19 to the external atmospheric environment). When the zero-point positioning mechanism clamps the worktable 5, it blocks the airflow in the clamping air passage 12 and the releasing air passage 13. When the zero-point positioning mechanism releases the worktable 5, it opens (or connects) the airflow in the clamping air passage 12 and the releasing air passage 13. By detecting the pressure change in the airflow channels in this way, the clamping or releasing status of the worktable 5 can be determined for the next operation. The cleaning air path 14 and the positioning detection air path 15 are respectively connected to the cleaning and detection dual-purpose hole 20. Typically, after passing through the cleaning and detection dual-purpose hole 20, the cleaning air path 14 needs to extend to each surface or groove of the zero-point positioning mechanism for comprehensive cleaning. Similarly, the positioning detection air path 15, after passing through the cleaning and detection dual-purpose hole 20, needs to extend to the upper surface of the zero-point positioning mechanism (i.e., the airtightness detection hole 43 mentioned later) to detect the positioning of the workbench 5. Specifically, the positioning detection air path 15 can extend through the cleaning and detection dual-purpose hole 20 to the upper surface of the zero-point positioning mechanism (or to the airtightness detection hole 43 mentioned later), and then connect to the release vent 19. A pressure feedback device 22 installed on the path connecting the release vent 19 to the external atmospheric environment can then provide feedback on air pressure changes to determine the positioning of the workbench; alternatively, a pressure feedback device 22 can be directly connected to the outside of the workbench surface or directly installed inside the airtightness detection hole 43 mentioned later (however, the latter two solutions require further overcoming of structural conflicts and are only provided as reference ideas here). The oil circuit is connected to the oil inlet 21 to control the loosening and tightening of the zero-point positioning mechanism on the worktable 5.

[0041] More specifically, the clamping air passage 12, the releasing air passage 13, the cleaning air passage 14, and the positioning detection air passage 15 are all connected to the same air source, which provides a standard 5 bar pressure airflow. Both the releasing air passage 13 and the positioning detection air passage 15 are equipped with a pressure regulating valve 23 and a pressure gauge 24, providing a 2 bar pressure airflow to both via the pressure regulating valve 23. Furthermore, [the following is an appendix] Figure 8 The circuit connected to port 5 is for releasing air, and the circuit connected to port 4 is for clamping and controlling exhaust.

[0042] Example 3: This example provides a specific zero-point positioning mechanism based on Example 2. For example... Figure 4-7As shown, the zero-point positioning mechanism in this embodiment includes a clamping assembly 25 disposed on the positioning disk 3 and a positioning pin 26 disposed on the worktable 5, which can form a detachable connection. More specifically, the clamping assembly 25 includes a base 27, a piston 28, a clamping ball 29, and a clamping spring 30. The piston 28 is slidably disposed within the base 27. A locking groove 31 is provided in the middle of the piston 28. A ring of piston 28 ball cage (usually an annular groove) is disposed within the locking groove 31. The clamping ball 29 is disposed within the piston 28 ball cage (the clamping ball 29 will not fall out of the piston 28 ball cage). A clamping groove is provided around the locking groove 31 on the piston 28. A clamping spring 30 is disposed within the clamping groove. A positioning cone surface 32 is provided on the positioning pin. An oil inlet channel 33 communicating with the oil inlet hole 21 is provided on the base 27. When the clamping assembly releases the locating pin, hydraulic oil enters through the oil inlet channel 33, pushing the piston 28 upward. This overcomes the spring force, and the clamping ball 29 enters the ball cage of the piston 28, releasing the locating pin. When the clamping assembly clamps the locating pin, the clamping spring 30 uses its spring force to push the piston 28 downward. Hydraulic oil is discharged through the oil inlet channel 33 (normally, there is no oil pressure in the oil inlet channel 33 at this time). Due to space constraints, the clamping ball 29 cannot fall and is stuck on the upper edge of the ball cage of the piston 28, thus securing the locating pin. It should be noted that the above description of the zero-point positioning mechanism only outlines its general and essential structure. More detailed structures can be found in existing zero-point positioning mechanisms. For example, the locating pin can be connected to the limiting sleeve 50 using screws 49, with a floating spring 51 placed in between. This allows the locating pin to float, preventing damage to the locating pin from collision with the clamping mechanism due to positioning errors of the worktable 5 during component exchange.

[0043] In this embodiment, the positioning disk 3 is provided with a mother disk 34, and the mother disk 34 is provided with 6 sets of clamping components 25 (the number of clamping components may not be limited to 6 sets; the number of clamping mechanisms required can be calculated based on the cutting torque of the tool feed). The worktable 5 is provided with a number of positioning pins 26 equal to the number of clamping components 25. The clamping components include angular positioning clamping components 35, center positioning clamping components 36, and general-purpose clamping components 37. The positioning pins 26 on the worktable 5 include angular positioning pins 38, center positioning pins 39, and general-purpose positioning pins 40, which correspond one-to-one with the clamping components on the mother disk 34. The clamping and releasing principles of the above-mentioned positioning pins and clamping components are the same, only the specific categories are different. The specific structural categories can directly adopt the relevant structural settings in the prior art.

[0044] Example 4 is based on Example 3, and further refines the air path arrangement by combining a specific zero-point positioning mechanism structure. Specifically, a detection air path 41 is provided on the base 27, which is connected to the clamping air path 12 and the releasing air path 13 respectively, as shown below. Figure 10As shown, a control valve 42 is provided on the detection gas path 41. The control valve 42 is in contact with the piston 28, and the control valve 42 is opened or closed by the up and down movement of the piston 28. Figure 11 As shown, the upper end of the base 27 of the clamping mechanism is provided with a plurality of airtightness detection holes 43, and the inner wall of the locking groove 31 is provided with a cleaning air blowing hole 44. The airtightness detection holes 43 and the cleaning air blowing hole 44 are respectively connected to the cleaning detection dual-purpose hole 20.

[0045] Example 5 is an optimization of Example 4 regarding the brake mechanism 4. In this example, a set of brake mechanisms 4 is provided on each of the four sides of the slide 1. Each brake mechanism 4 includes a brake seat 45, a brake slider 46, a brake pad 47, and a brake oil passage 48. The brake seat 45 is mounted on the slide 1, and the brake slider 46 is slidably connected to it. The brake oil passage 48 is located between the brake slider 46 and the brake seat 45, controlling the up-and-down movement of the brake slider 46 by the flow of hydraulic oil. The brake pad 47 is located at the upper end of the brake slider 46 and is used to lock the positioning disc 3.

[0046] The zero-point positioning turntable of this invention has been tested: Clamping accuracy test: The positioning error after 10 repeated clamping cycles on the five edges of a 1000 mm worktable is ≤ ±0.01 mm; Clamping force test: After the hydraulic system loses pressure, the mechanical clamping state can withstand a cutting torque of 1000 N•m; Cleaning efficiency test: When the air pressure is 5MPa, the removal rate of iron filings from the positioning pins reaches 99.9%.

[0047] Example 6: This example provides a rotary table changing control method (i.e., the changing step of the rotary table 5 in a horizontal machining center), which uses the zero-point positioning rotary table described in the above examples, such as... Figure 12 As shown in the diagram (A represents hydraulic release of the clamping mechanism; B represents air intake for clamping control; C represents air blowing for cleaning; D represents air tightness detection (worktable in position); E represents air intake for clamping release; T1 represents the initial position of the machine tool; T2 represents the start of worktable replacement; T3 represents worktable exchange; T4 represents the start of clamping; T5 represents the clamping mechanism being clamped; T6 represents the start of machining; T7 represents machining in progress; T8 represents the end of machining; T9 represents the start of worktable replacement; T10 represents pulse interruption detection), the following steps are included: S1. Hydraulic oil is supplied to the clamping assembly through the oil circuit to loosen the positioning pin, that is, the zero-point positioning mechanism is controlled to loosen the worktable 5. The air release circuit 13 is vented to detect that the zero-point positioning mechanism is in the loose state (the cleaning air circuit 14 can be vented at the same time to clean the zero-point positioning mechanism); the old worktable 5 is lifted manually or by a robot. S2, Cleaning air passage 14 air blowing cleaning zero-point positioning mechanism (or air blowing cleaning clamping mechanism); S3, Transfer to new workbench 5; S4. Position the worktable 5 by matching the positioning pin and clamping mechanism, release the hydraulic pressure, and mechanically lock the clamping mechanism after it engages. The clamping air circuit 12 is vented to detect that the zero-point positioning mechanism (or clamping mechanism) is in the clamping state and that it is in position. The positioning detection air circuit 15 is vented to detect that the new worktable 5 is installed in place (at this time, the loosening air circuit 13 and the cleaning air circuit 14 can be closed, while the clamping air circuit 12 and the positioning detection air circuit 15 remain vented until the processing is completed). S5. The encoder controls the direct drive motor 2 to drive the positioning disk 3, which drives the worktable 5 to rotate to the required angle of the workpiece to be processed. Hydraulic oil is introduced into the brake mechanism 4, and the brake mechanism 4 is controlled to lock the positioning disk 3 until the processing process is completed. S6. Release the pressure of the brake mechanism 4, control the brake mechanism 4 to release the positioning plate 3, and rotate the worktable to the next process, and cycle to complete the precision machining of the milling, drilling, reaming, boring and other processes on the periphery of the workpiece.

[0048] Furthermore, in the description of this invention, unless otherwise stated, the terms "multiple", "multiple roots", and "multiple groups" mean two or more, and the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", and "outer" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, only for the convenience of describing this invention and simplifying the description, and not to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this invention.

[0049] The specific embodiments of the present invention have been described in detail above with reference to the accompanying drawings. However, the present invention is not limited to the above embodiments. Within the scope of knowledge possessed by those skilled in the art, various changes can be made without departing from the spirit of the present invention.

Claims

1. A zero-point positioning turntable, comprising a slide (1), a direct drive motor (2), a positioning disk (3), a braking mechanism (4), a zero-point positioning mechanism, and a worktable (5), wherein the direct drive motor (2) is installed inside the slide (1), a spindle (6) is provided inside the direct drive motor (2), and a grating ruler (7) is provided outside the spindle (6), the positioning disk (3) is provided on the direct drive motor (2) and can drive it to rotate, the braking mechanism (4) is installed on the slide (1) and can lock the positioning disk (3), and the worktable (5) is detachably connected to the positioning disk (3) through the zero-point positioning mechanism, characterized in that: It also includes an oil circuit and multiple air circuits, which are integrated on the spindle (6) and extend to the zero-point positioning mechanism. The oil circuit controls the zero-point positioning mechanism to loosen and tighten the worktable (5), and the multiple air circuits clean and inspect the zero-point positioning mechanism respectively. The inspection includes the clamping state detection, loosening state detection and installation in place detection of the worktable (5).

2. The zero-point positioning turntable according to claim 1, characterized in that: The mandrel (6) is fixedly installed. The upper end of the mandrel (6) is provided with multiple annular grooves (8). The mandrel (6) is provided with multiple first passages (9). One end of the first passage (9) is connected to one of the annular grooves (8), and the other end passes through the mandrel (6). The mandrel (6) is provided with a rotatable bushing (10). The bushing (10) is provided with a positioning disk (3). The bushing (10) is provided with multiple second passages (11). One end of the second passage (11) is connected to one of the annular grooves (8) on the mandrel (6), and the other end passes through the bushing (10) and enters the zero-point positioning mechanism. The first passage (9), the annular groove (8), and the second passage (11) are connected to form the oil passage or air passage.

3. The zero-point positioning turntable according to claim 1, characterized in that: The air path includes a clamping air path (12), a releasing air path (13), a cleaning air path (14), and a positioning detection air path (15). The clamping air path (12) is used to detect whether the zero-point positioning mechanism clamps the worktable (5). The releasing air path (13) is used to detect whether the zero-point positioning mechanism releases the worktable (5). The cleaning air path (14) is used to blow air to clean the zero-point positioning mechanism. The positioning detection air path (15) is used to detect whether the worktable (5) is installed in place.

4. The zero-point positioning turntable according to claim 3, characterized in that: The positioning plate (3) is provided with a clamping air inlet (16), a clamping exhaust port (17), a loosening air inlet (18), a loosening exhaust port (19), a cleaning and testing dual-purpose port (20), and an oil inlet (21). The clamping air passage (12) is connected to the clamping air inlet (16) and the clamping exhaust port (17) in sequence. The loosening air passage (13) is connected to the loosening air inlet (18) and the loosening exhaust port (19) in sequence. The clamping exhaust port (17) and the clamping air inlet (18) and the clamping exhaust port (19) are provided with a clamping air inlet (16), a clamping exhaust port (17), a loosening air inlet (18), a loosening exhaust port (19), a cleaning and testing dual-purpose port (20), and an oil inlet (21). Pressure feedback devices (22) are respectively installed on the vent (19); when the zero-point positioning mechanism clamps the worktable (5), it blocks the airflow of the clamping airway (12) and the venting airway (13); when the zero-point positioning mechanism releases the worktable (5), it opens the airflow of the clamping airway (12) and the venting airway (13); the cleaning airway (14) and the positioning detection airway (15) are respectively connected to the cleaning detection dual-purpose hole (20); the oil passage is connected to the oil inlet hole (21).

5. The zero-point positioning turntable according to claim 4, characterized in that: The clamping air passage (12), the releasing air passage (13), the cleaning air passage (14), and the positioning detection air passage (15) are all connected to the same air source, which provides a 5 bar pressure airflow. The releasing air passage (13) and the positioning detection air passage (15) are each equipped with a pressure regulating valve (23) and a pressure gauge (24), which provide a 2 bar pressure airflow to both through the pressure regulating valve (23).

6. The zero-point positioning turntable according to claim 5, characterized in that: The zero-point positioning mechanism includes a clamping component (25) disposed on the positioning disk (3) and a positioning pin (26) disposed on the worktable (5), which can form a detachable connection; The clamping assembly includes a base (27), a piston (28), a clamping ball (29), and a clamping spring (30). The piston (28) is slidably disposed within the base (27). A locking groove (31) is provided in the middle of the piston (28). A ring of piston (28) ball cages is disposed within the locking groove (31). A clamping ball (29) is disposed within the piston (28) ball cages. A clamping groove is circumferentially disposed around the locking groove (31) on the piston (28). A clamping spring (30) is disposed within the clamping groove. A positioning pin is provided with... The base (27) is provided with a positioning cone surface (32) and an oil inlet channel (33). When released, the oil inlet channel (33) enters the hydraulic oil and pushes the piston (28) to move upward, overcoming the spring force, and the clamping ball (29) enters the ball cage of the piston (28) and releases the positioning pin. When clamped, the clamping spring (30) uses the spring force to push the piston (28) to move downward, and the hydraulic oil is discharged through the oil inlet channel (33). The clamping ball (29) cannot fall due to space limitation and is stuck on the upper edge of the ball cage of the piston (28), which locks the positioning pin.

7. The zero-point positioning turntable according to claim 6, characterized in that: The positioning plate (3) is provided with a mother plate (34), and the mother plate (34) is provided with multiple sets of clamping components. The worktable (5) is provided with a number of positioning pins equal to the number of clamping components. The clamping components include angular positioning clamping components (35), center positioning clamping components (36) and universal clamping components (37). The positioning pins on the worktable (5) include angular positioning pins (38), center positioning pins (39) and universal positioning pins (40) that correspond one-to-one with the clamping components on the mother plate (34).

8. The zero-point positioning turntable according to claim 7, characterized in that: The base (27) is provided with a detection air passage (41) that is connected to the clamping air passage (12) and the releasing air passage (13) respectively. The detection air passage (41) is provided with a control valve (42). The control valve (42) is switched and abutted against the piston (28). The control valve (42) is opened or closed by the piston (28) moving up and down. The upper end of the base (27) of the clamping assembly is provided with a plurality of airtightness detection holes (43) in the circumferential direction. The inner wall of the locking groove (31) is provided with a cleaning air blowing hole (44). The airtightness detection hole (43) and the cleaning air blowing hole (44) are respectively connected to the cleaning detection dual-purpose hole (20).

9. The zero-point positioning turntable according to claim 1, characterized in that: The braking mechanism (4) includes a brake seat (45), a brake slider (46), a brake pad (47), and a brake oil passage (48). The brake seat (45) is mounted on a slide (1). The brake slider (46) is slidably connected to the brake seat (45). The brake oil passage (48) is located between the brake slider (46) and the brake seat (45). The brake slider (46) is controlled to slide up and down by the inlet and outlet of hydraulic oil. The brake pad (47) is located at the upper end of the brake slider (46) and is used to lock the positioning disc (3).

10. A turntable switching control method, characterized in that: The zero-point positioning turntable according to any one of claims 1-9 includes the following steps: S1. Control the zero-point positioning mechanism to release the worktable (5). The air passage detects that the zero-point positioning mechanism is in the released state; manually or with a robot arm, lift the old worktable (5). S2, Air passage ventilation and air blowing cleaning zero-point positioning mechanism; S3, transfer the new workbench (5); S4. The zero-point positioning mechanism mechanically locks the new worktable (5), and the air passage detects that the zero-point positioning mechanism is in a clamping state and that the new worktable (5) is installed in place. S5. Control the direct drive motor (2) to drive the positioning disk (3), drive the worktable (5) to rotate to the required angle of the workpiece to be processed, and control the brake mechanism (4) to lock the positioning disk (3) until the processing process is completed. S6. Control the brake mechanism (4) to release the positioning plate (3), and the worktable rotates to the next process, and completes the processing of the surrounding surfaces of the workpiece in a cycle.

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