Flexible production robot mechanical arm capable of rapidly replacing tools

Abstract

The invention provides a flexible production robot mechanical arm capable of rapidly replacing and installing tools, and relates to the technical field of mechanical arms, the mechanical arm comprises a cylinder piece composed of a fixed installation cylinder and an arc splicing piece, an internally integrated multi-section type electric telescopic rod, a port assembly and a tool replacing and installing assembly, and four sets of production tools can be loaded in the cylinder. Through cooperation of a screw transmission mechanism and a guide strip, automatic translation and accurate positioning of a tool in a cylinder are achieved, a cross-shaped insertion groove in the end of an electric telescopic rod is connected with an insertion piece at the tail end of the tool in an inserted mode, mechanical connection is completed, and power connection sockets in the four corners of a sealing plate correspond to insertion type power connection rods on a tool blocking piece in a one-to-one mode. The buffering and limiting structure of the limiting ring and the guide strip driven by the reverse thread of the screw rod move in the radial direction, and it is guaranteed that interference and deviation are avoided in the tool replacement process. Compared with the prior art, automatic and rapid switching of multiple tools is achieved through the screw-guide strip linkage mechanism, and the problems that traditional reloading efficiency is low, the positioning error is large, and the electrical misplug risk exists are solved.

Description

Technical Field

[0001] The present invention belongs to the technical field of robotic arms, and more specifically, particularly relates to a flexible production robotic arm of a robot capable of quickly replacing tools. Background Art

[0002] In the field of flexible production, robotic arms of robots need to frequently switch tools such as grippers, welding torches, vision cameras, etc. to meet the processing requirements of multi-variety workpieces. The tool replacement of traditional robotic arms generally has problems such as low efficiency, insufficient positioning accuracy, and poor automation. In the prior art, tool replacement mostly relies on manual disassembly of bolts and plugging and unplugging of cables. The single replacement takes up to several minutes, and manual operation is likely to cause installation deviation of tools, affecting the quality of precision machining. Some automated replacement mechanisms adopt a single slide rail or turntable design, with limited tool storage capacity (usually ≤ 2 types), and lack effective anti-misinsertion protection, posing risks such as electrical connection misalignment and mechanical collision, and it is difficult to meet the requirements of rapid switching and high-precision operations in fields such as 3C electronics and precision assembly.

[0003] With the popularization of the "small batch, multi-variety" production mode, the market urgently needs a robotic arm with the capabilities of multi-tool automatic storage, rapid switching, and precise positioning. However, due to the complex transmission mechanism and insufficient accuracy of the guiding structure in traditional solutions, the reliability of replacement is low and the maintenance cost is high. At the same time, the electrical connection of tools mostly uses a general interface, lacking a unique position design, and is prone to short circuits or signal interference caused by misinsertion, further restricting the flexible production efficiency. The present invention solves multiple bottlenecks in the tool replacement speed, positioning accuracy, and safety of the prior art through innovative designs of screw drive and multiple positioning structures, providing key technical support for the flexible production of intelligent factories. Summary of the Invention

[0004] In order to solve the above technical problems, the present invention provides a flexible production robotic arm of a robot capable of quickly replacing tools to solve the above problems.

[0005] A flexible production robotic arm of a robot capable of quickly replacing tools includes a fixed mounting cylinder. A side groove is provided on the fixed mounting cylinder, and an arc-shaped splicing member is fixed to the side groove through bolts. The fixed mounting cylinder and the arc-shaped splicing member form a complete cylinder. One end of this cylinder is closed and the other end is open. A multi-section electric telescopic rod is fixedly installed inside the closed end of the cylinder formed by the fixed mounting cylinder and the arc-shaped splicing member. A cross-shaped slot is provided at the end of the telescopic rod of the multi-section electric telescopic rod. A port assembly is installed inside the open end of the cylinder formed by the fixed mounting cylinder and the arc-shaped splicing member. The port assembly includes a closing plate and four guide rods. A tool replacement assembly is installed inside the cylinder formed by the fixed mounting cylinder and the arc-shaped splicing member. The tool replacement assembly includes a limiting ring and two mounting rings, and four production tools are loaded inside the two mounting rings.

[0006] Preferably, the outer ring surface of the limit ring is fixedly connected to the inner wall of the fixed installation cylinder. Four L-shaped connecting pieces are fixedly connected to the inner ring surface of the limit ring. A limit rod is fixedly connected to the corner of each connecting piece, and a buffer pad is fixedly connected to the end of each limit rod.

[0007] Preferably, a through groove is formed in the middle part of the closing plate. Four power connection sockets are also installed on the inner surface of the closing plate, and the four power connection sockets are respectively located at the four corners of the through groove. Four guide rods are fixedly arranged in an annular array on the inner surface of the closing plate. Track grooves are formed on all four guide rods, and the track grooves penetrate through the closing plate. The surfaces of the four guide rods with the track grooves are flush with the four edges of the through groove respectively.

[0008] Preferably, inside the fixed installation cylinder, slide rails are fixedly installed on the left and right sides of the upper and lower production tool main bodies, and the same slide rails are fixedly installed on the upper and lower sides of the left and right production tool main bodies.

[0009] Preferably, an L-shaped plug is fixedly connected to the middle part of the end of each production tool main body. Stopping pieces are fixedly connected to the four corners of the end of each production tool main body. Among the four stopping pieces on the upper production tool, an inserted power connection rod is fixedly installed on the upper left stopping piece. Among the four stopping pieces on the lower production tool, an inserted power connection rod is fixedly installed on the lower right stopping piece. Among the four stopping pieces on the left production tool, an inserted power connection rod is fixedly installed on the lower left stopping piece. Among the four stopping pieces on the right production tool, an inserted power connection rod is fixedly installed on the upper right stopping piece.

[0010] Preferably, fixing seats are fixedly arranged in an annular array on the inner ring surface of each installation ring. The fixing seats on the two installation rings are horizontally aligned. Screws are rotatably installed between the four pairs of horizontally aligned fixing seats. Two threaded rings are threadedly sleeved on each screw. The thread surfaces of the two threaded rings on the same screw are opposite. Two rotating rods are rotatably connected to each threaded ring. At the ends of the four rotating rods on the same screw, a guiding bar is rotatably connected. The same track groove is formed on each guiding bar. A connecting bar is clamped in the track groove on each guiding bar. The connecting bar has the same size as the slide rail. Four driving motors arranged in an annular array are fixedly installed on the surface of the limit ring facing the closing plate, and the output shafts of the four driving motors are respectively fixedly connected to the four screws.

[0011] Compared with the prior art, the present invention has the following beneficial effects:

[0012] In the present invention, through the collaborative design of a screw drive mechanism and a multi - section electric telescopic rod, the automatic switching of four production tools inside the cylinder is realized. The driving motor drives the screw to rotate, and through reverse threads, the threaded rings move towards / away from each other. The guide bar is radially moved by the rotating rod, precisely controlling the translation of the tool. The efficiency is improved compared with the traditional manual replacement. From the retraction and power - off of the old tool (the plug - in power - receiving rod disengages from the power - receiving socket) to the positioning and power - on of the new tool (the plug is precisely inserted into the slot), no manual intervention is required, adapting to the rapid switching requirements of multi - variety and small - batch production, and significantly reducing the production line downtime.

[0013] In the present invention, the L - shaped connecting piece of the limit ring fixes the limit rod, and the end buffer pad (made of nitrile rubber) provides flexible buffering when the tool retracts, reducing the impact load and extending the mechanical life. The slide rails on the side of the tool form a double - sliding fit with the guide rod track groove and the guide bar track groove, ensuring that the tool has no deviation during the extension / retraction process. The multi - section electric telescopic rod is internally provided with a displacement sensor, which is synchronized with the position signal of the driving motor in real - time. Through PLC control, the multi - axis motion error is ≤0.5 mm, meeting the requirements of high - precision scenarios such as precision assembly and micro - part operation.

[0014] In the present invention, several spare production tools are stored in a fixed installation cylinder, with good protection effect and small occupied space. The robotic arm can be used for operations in small spaces, improving the applicability.

[0015] In the present invention, the installation ring can load different functional tools (such as grasping, detecting, processing types). By replacing the front - end working components, it can adapt to diverse working conditions without modifying the robotic arm body, enhancing the flexible production ability. Description of the Drawings

[0016] Figure 1 is the overall structural schematic diagram of the present invention;

[0017] Figure 2 is the position schematic diagram of the slide rail, plug - in and production tool in the present invention;

[0018] Figure 3 is the structural schematic diagram of the fixed installation cylinder in the present invention;

[0019] Figure 4 is the position schematic diagram of the installation ring and the driving motor in the present invention;

[0020] Figure 5 is the structural schematic diagram of the closed plate in the present invention;

[0021] Figure 6 is the front - end structural schematic diagram of the production tool in the present invention;

[0022] Figure 7 is the rear - end structural schematic diagram of the production tool in the present invention;

[0023] Figure 8 is the enlarged structural schematic diagram of part A in the present invention; Figure 3

[0024] Figure 9 is the enlarged structural schematic diagram of part B in the present invention; Figure 3

[0025] Figure 10 is the enlarged structural schematic diagram of part C in the present invention. Figure 4

[0026] In the figure, the corresponding relationship between the component names and the drawing reference numbers is as follows: 1, fixed mounting cylinder; 2, arc-shaped splicing piece; 3, mounting ring; 4, closing plate; 5, limiting ring; 6, multi-section electric telescopic rod; 7, connecting piece; 9, limiting rod; 10, buffer pad; 11, slot; 12, power connection socket; 13, through slot; 14, guide rod; 15, track groove; 16, production tool; 17, drive motor; 18, screw; 19, fixed seat; 20, threaded ring; 21, rotating rod; 22, guide strip; 23, connecting strip; 24, slide rail; 25, stopper; 26, plug-in power connection rod; 27, plug-in component. Specific Embodiment

[0027] The following further describes in detail the embodiments of the present invention in conjunction with the drawings and embodiments. The following embodiments are used to illustrate the present invention, but cannot be used to limit the scope of the present invention.

[0028] Please refer to Figures 1 - 10 , the present invention provides a flexible production robot manipulator capable of quickly replacing tools, including a fixed mounting cylinder 1. A side groove is provided on the fixed mounting cylinder 1, and an arc-shaped splicing piece 2 is fixed to the side groove by bolts. The fixed mounting cylinder 1 and the arc-shaped splicing piece 2 form a complete cylinder. One end of the cylinder is closed and the other end is open. A multi-section electric telescopic rod 6 is fixedly installed inside the closed end of the cylinder formed by the fixed mounting cylinder 1 and the arc-shaped splicing piece 2. A cross-shaped slot 11 is provided at the end of the telescopic rod of the multi-section electric telescopic rod 6. A port component is installed inside the open end of the cylinder formed by the fixed mounting cylinder 1 and the arc-shaped splicing piece 2. The port component includes a closing plate 4 and four guide rods 14. A tool replacement component is installed inside the cylinder formed by the fixed mounting cylinder 1 and the arc-shaped splicing piece 2. The tool replacement component includes a limiting ring 5 and two mounting rings 3. Four production tools 16 are loaded inside the two mounting rings 3;

[0029] ​​​The outer ring surface of the limit ring 5 is fixedly connected to the inner wall of the fixed installation cylinder 1. Four L-shaped connecting pieces 7 are fixedly connected to the inner ring surface of the limit ring 5. A limit rod 9 is fixedly connected to the corner of each connecting piece 7. A buffer pad 10 is fixedly connected to the end of each limit rod 9. The buffer pad 10 is used for position limitation and impact buffering when the production tool 16 retracts. A through groove 13 is provided in the middle part of the closing plate 4. The through groove 13 allows the production tool 16 to extend for operation. Four power connection sockets 12 are also installed on the inner-facing surface of the closing plate 4. The four power connection sockets 12 are respectively located at the four corners of the through groove 13. Four guide rods 14 are fixedly arranged in an annular array on the inner-facing surface of the closing plate 4. A track groove 15 is provided on each of the four guide rods 14. The track groove 15 provides sliding guidance for the slide rail 24 of the production tool 16. The track groove 15 penetrates the closing plate 4. The surfaces of the four guide rods 14 with the track grooves 15 are flush with the four edges of the through groove 13. Inside the fixed installation cylinder 1, slide rails 24 are fixedly installed on the left and right sides of the main body shells of the two production tools 16 located above and below. Slide rails 24 of the same kind are fixedly installed on the upper and lower sides of the main body shells of the two production tools 16 located on the left and right. An L-shaped plug-in part 27 is fixedly connected to the middle part of the end of each production tool 16 main body shell. The specific distribution positions of the four production tools 16, the four pairs of slide rails 24, and the four plug-in parts 27 are shown in Figure 2 ;

[0030] A stopper 25 is fixedly connected to each of the four corners of the end of each production tool 16 main body shell. Among the four stoppers 25 on the production tool 16 located above, an inserted power connection rod 26 is fixedly installed on the upper left stopper 25. Among the four stoppers 25 on the production tool 16 located below, an inserted power connection rod 26 is fixedly installed on the lower right stopper 25. Among the four stoppers 25 on the production tool 16 located on the left, an inserted power connection rod 26 is fixedly installed on the lower left stopper 25. Among the four stoppers 25 on the production tool 16 located on the right, an inserted power connection rod 26 is fixedly installed on the upper right stopper 25. The positions of the power connection rods of different production tools 16 are unique to avoid incorrect insertion;

[0031] On the inner ring surface of each mounting ring 3, fixing seats 19 are fixedly arranged in an annular array. The fixing seats 19 on the two mounting rings 3 are aligned horizontally. Screws 18 are rotatably installed between every four pairs of horizontally aligned fixing seats 19. Two threaded rings 20 are sleeved on each screw 18 in a threaded manner. The threaded surfaces of the two threaded rings 20 on the same screw 18 are opposite. Two rotating rods 21 are rotatably connected to each threaded ring 20. At the ends of the four rotating rods 21 on the same screw 18, a guiding bar 22 is rotatably connected. An identical track groove 15 is formed in each guiding bar 22. A connecting bar 23 is clamped in the track groove 15 of each guiding bar 22. The connecting bar 23 has the same size as the sliding rail 24. The four connecting bars 23 are respectively fixedly connected to the sides of the four production tools 16. On the surface of the limiting ring 5 facing the closing plate 4, four driving motors 17 arranged in an annular array are fixedly installed. The output shafts of the four driving motors 17 are respectively fixedly connected to the four screws 18.

[0032] Through the modular cylindrical structure, the multi-section electric telescopic rod 6 and the screw transmission mechanism, rapid switching and precise positioning of various production tools 16 are realized. The following will, in combination with the attached drawings, elaborate on the implementation manners in detail from three aspects: mechanical structure, control logic, and electrical connection.

[0033] The slot 11 is used for plugging with the plug-in 27 of the production tool 16 to achieve mechanical positioning and power transmission. The power connection socket 12 and the plug-in power connection rod 26 adopt an anti-dropping design and support DC power supply. The production tool 16 is internally provided with a storage chip, which automatically communicates with the control cabinet after being powered on to transmit the tool type and working parameters. The multi-section electric telescopic rod 6 is internally provided with a displacement sensor, which is synchronized with the position signal of the driving motor 17 in real time. Through PLC control, multi-axis motion error control is realized to meet the requirements of high-precision scenarios such as precision assembly and micro-part operation.

[0034] The power connection socket 12 and the plug-in power connection rod 26 adopt a four-core pinhole interface (the power connection socket 12 is the female end pinhole, and the plug-in power connection rod 26 is the male end plug pin). The pinhole layout follows the unique position coding, eliminating the possibility of incorrect insertion from the mechanical structure;

[0035] The control circuit board of each production tool 16 integrates 256K EEPROM (such as AT24C256) to store information such as the tool type code (such as 01 = gripper, 02 = screwdriver), rated voltage, maximum current, and motion parameters (such as the opening and closing stroke of the gripper). After being powered on, the signal pins (2 cores) of the power connection socket 12 read the chip data through the I 2 C bus, and the tool parameters are loaded within 100 ms without manual configuration (the communication protocol follows the JEDEC standard).

[0036] The buffer pad 10 integrates an FSR thin-film pressure sensor (range 0 - 50N, accuracy ±2%). When the end pressure ≥ 10N, it outputs a high-level signal to trigger the next action.

[0037] The cooperative logic between the screw 18 and the multi-section electric telescopic rod 6 adopts a master-slave control mode.

[0038] The multi-section electric telescopic rod 6 is internally equipped with a displacement sensor to provide real-time position feedback. The controller uses a PLC or an industrial control computer and communicates with the drive motor 17 and the sensor through a bus to achieve synchronous control and status monitoring of the tool-changing process. Through modular structure design and automated control, and through innovative designs of the screw drive mechanism and electrical interfaces, the present invention enables rapid and precise tool-changing of the production tool 16, is suitable for multi-variety and small-batch production scenarios, and enhances the flexible operation ability of the robotic manipulator.

[0039] Working principle:

[0040] The main bodies of the four production tools 16 have the same housing, but different production tools (such as grippers, dust cleaning tools, screwdrivers, cutting tools, etc.) are installed at the front end. During normal operation, when one of the production tools 16 is in use, the production tool 16 is exposed from the through slot 13 by the multi-section electric telescopic rod 6. The stopper 25 presses against the closing plate 4, and the plug-in power connection rod 26 on the stopper 25 is inserted into the corresponding power connection socket 12 for power supply to the production tool 16. When a tool change is required, the multi-section electric telescopic rod 6 retracts, and in cooperation with the rotation of the drive motor 17, the two production tools 16 are shifted and changed. The specific process is as follows:

[0041] First, the multi-section electric telescopic rod 6 receives a signal and retracts. Due to the insertion of the slot 11 and the plug 27, the retraction of the multi-section electric telescopic rod 6 drives the production tool 16 in the through slot 13 to retract. During the retraction process, the plug-in power connection rod 26 on the production tool 16 disengages from the power connection socket 12, and the production tool 16 is powered off. The slide rail 24 slides along the track groove 15. Before the slide rail 24 is about to disengage from the track groove 15, the connecting strip 23 on the production tool 16 is butted and inserted into the corresponding guiding strip 22. Then, the multi-section electric telescopic rod 6 continues to retract until the end of the production tool 16 presses against the four buffer pads 10. The buffer pads 10 are provided with sensors that receive the in-place signal. At this time, the connecting strip 23 and the corresponding guiding strip 22 are fully engaged;

[0042] After the connecting bar 23 is fully engaged with the corresponding guiding bar 22, the drive motor 17 controlling the guiding bar 22 receives a signal and rotates. The rotation of the drive motor 17 drives the screw 18 to rotate, causing the two threaded rings 20 on the screw 18 to separate from each other. The guiding bar 22 is retracted by the rotating rod 21, thereby driving the production tool 16 to retract. The plug 27 is separated from the slot 11, and the production tool 16 is disengaged from the rod end of the multi-joint electric telescopic rod 6, creating a space aligned with the multi-joint electric telescopic rod 6, which is reserved for the production tool 16 to be switched.

[0043] After creating a space aligned with the multi-joint electric telescopic rod 6, another production tool 16 is selected as needed, and the drive motor 17 controlling the production tool 16 is started to rotate. The rotation of the drive motor 17 drives the production tool 16 to move into the reserved space through the screw 18, threaded ring 20, rotating rod 21, and guiding bar 22 until the plug 27 on the production tool 16 is inserted into the slot 11. At this time, the sensor on the buffer pad 10 receives a signal, and the multi-joint electric telescopic rod 6 is started again. As the telescopic rod extends, the production tool 16 is pushed away from the guiding bar 22. Before disengaging from the guiding bar 22, the slide rail 24 on the production tool 16 engages with the track groove 15 to ensure that the production tool 16 does not deviate and is smoothly inserted into the through groove 13 until the stopper 25 on the production tool 16 abuts against the closing plate 4, and the plug-in power connection rod 26 is inserted into a corresponding power connection socket 12 to complete the power-on.

[0044] After the production tool 16 disengages from the guiding bar 22, the guiding bar 22 remains in place, waiting for the next switching of the production tool 16 and can directly dock with the connecting bar 23 of the retracted production tool 16.

[0045] The embodiments of the present invention are given for purposes of illustration and description, and are not exhaustive or limit the invention to the disclosed form. Many modifications and variations are obvious to those of ordinary skill in the art. The embodiments are selected and described to better illustrate the principles and practical applications of the present invention, and to enable those of ordinary skill in the art to understand the present invention and design various embodiments with various modifications suitable for specific purposes.

Claims

1. A flexible production robot arm capable of quickly changing tools, characterized in that: The fixed installation cylinder (1) comprises a side groove, on which an arc-shaped splicing piece (2) is fixed by bolts, and the fixed installation cylinder (1) and the arc-shaped splicing piece (2) form a complete cylinder, one end of which is closed and the other end is open; A multi-section electric telescopic rod (6) is fixedly installed in the closed end of the cylinder composed of the fixed installation cylinder (1) and the arc-shaped splicing piece (2), and a cross slot (11) is provided at the end of the telescopic rod of the multi-section electric telescopic rod (6); A port assembly is installed in the open end of the cylinder composed of the fixed installation cylinder (1) and the arc-shaped splicing piece (2), and the port assembly includes a closing plate (4) and four guide rods (14); A tool changing assembly is installed in the cylinder composed of the fixed installation cylinder (1) and the arc-shaped splicing piece (2), and the tool changing assembly includes a limiting ring (5) and two installation rings (3); Four production tools (16) are loaded in the two mounting rings (3).

2. A flexible production robot arm capable of quickly changing tools as claimed in claim 1, characterized in that: The outer ring surface of the limiting ring (5) is fixedly connected to the inner wall of the fixed installation cylinder (1), and the inner ring surface of the limiting ring (5) is fixedly connected to four L-shaped connecting pieces (7), and the corner of each connecting piece (7) is fixedly connected to a limiting rod (9), and the end of each limiting rod (9) is fixedly connected to a buffer pad (10).

3. A flexible production robot arm capable of quickly changing tools as claimed in claim 1, characterized in that: A through slot (13) is provided in the middle of the closing plate (4), and four power sockets (12) are installed on the inwardly facing surface of the closing plate (4), and the four power sockets (12) are respectively located at the four corners of the through slot (13). Four guide rods (14) are fixed in a ring-shaped array on the inwardly facing surface of the closing plate (4), and track slots (15) are provided on the four guide rods (14), and the track slots (15) penetrate the closing plate (4), and the surfaces of the four guide rods (14) provided with the track slots (15) are respectively flush with the four groove edges of the through slot (13).

4. A flexible production robot arm capable of quickly changing tools as claimed in claim 1, characterized in that: In the fixed installation cylinder (1), the left and right sides of the main shells of the two upper and lower production tools (16) are fixed with slide rails (24), and the upper and lower sides of the main shells of the two left and right production tools (16) are fixed with the same slide rails (24).

5. A flexible production robot arm capable of quickly changing tools as claimed in claim 4, characterized in that: An L-shaped plug-in (27) is fixedly connected to the middle part of the end of the main shell of each production tool (16), and a stopper (25) is fixedly connected to the four corners of the end of the main shell of each production tool (16).

6. A flexible production robot arm capable of quickly changing tools as claimed in claim 5, characterized in that: Among the four blocking members (25) on the upper production tool (16), an insertable power connection rod (26) is fixedly mounted on the upper left blocking member (25); Among the four blocking members (25) on the production tool (16) at the bottom, an insertable power connection rod (26) is fixedly mounted on the blocking member (25) at the bottom right; Among the four blocking members (25) on the production tool (16) on the left side, an insertable power connection rod (26) is fixedly mounted on the blocking member (25) at the lower left side; Among the four blocking members (25) on the production tool (16) on the right side, an insertable power connection rod (26) is fixedly mounted on the blocking member (25) on the upper right side.

7. A flexible production robot arm capable of quickly changing tools as claimed in claim 1, characterized in that: The inner ring surface of each mounting ring (3) is fixed with a fixing seat (19) in a ring-shaped array, the fixing seats (19) on the two mounting rings (3) are aligned in the horizontal direction, screw rods (18) are rotatably mounted between the four pairs of horizontally aligned fixing seats (19), each screw rod (18) is threadedly sleeved with two threaded rings (20), and the threaded surfaces of the two threaded rings (20) on the same screw rod (18) are opposite.

8. A flexible production robot arm capable of quickly changing tools as claimed in claim 7, characterized in that: Each threaded ring (20) is rotatably connected to two rotating rods (21); on the same screw rod (18), the ends of the four rotating rods (21) are rotatably connected to guide bars (22); and each guide bar (22) is provided with a same track groove (15).

9. A flexible production robot arm capable of quickly changing tools as claimed in claim 8, characterized in that: A connecting strip (23) is clamped in the track groove (15) on each guide strip (22). The connecting strip (23) has the same size as the slide rail (24). The four connecting strips (23) are fixedly connected to the sides of four production tools (16) respectively.

10. A flexible production robot arm capable of quickly changing tools as claimed in claim 9, characterized in that: Four drive motors (17) in a ring-shaped array are fixedly mounted on the surface of the limiting ring (5) facing the closing plate (4), and the output shafts of the four drive motors (17) are respectively fixedly connected to four screw rods (18).

Images