A changing mechanism for a metal milling machine tool

Abstract

This utility model relates to the field of metal processing technology and discloses a tool changing mechanism for a metal milling and grinding machine tool. It includes a tool magazine and a grinding wheel magazine arranged along the same axis of rotation, a switching mount, a servo rotary platform, and an automatic locking interface at the spindle end. The tool magazine stores milling tools, and the grinding wheel magazine stores grinding wheels; both are fixedly mounted on the switching mount. The switching mount is connected to the machine tool bed via the servo rotary platform, which drives the switching mount to rotate around the axis of rotation, aligning the tool magazine or grinding wheel magazine sequentially with the spindle axis. The tool magazine and grinding wheel magazine are equipped with flip-up protective covers to prevent chips and coolant from entering. This mechanism enables high-speed automatic switching between tools and grinding wheels, reducing manual intervention and improving processing efficiency and positioning accuracy.

Description

Technical Field

[0001] This utility model relates to the field of metal processing technology, specifically a changing mechanism for a metal material milling machine tool. Background Technology

[0002] In the field of metal processing, milling and grinding are two common and important machining methods. Milling is typically used for roughing and shaping materials, efficiently removing material; grinding, on the other hand, is suitable for surface finishing and dimensional accuracy control, achieving higher surface quality and lower machining tolerances. In actual production, milling and grinding operations are often performed sequentially on the same workpiece to balance machining efficiency and accuracy.

[0003] Currently, when switching between milling and grinding operations on existing machine tools, the cutting tools or grinding wheels are generally changed manually. This method not only requires machine downtime but also demands that the operator position and lock the cutting tools or grinding wheels, a time-consuming process that heavily relies on the operator's skill. Furthermore, manual switching is prone to reduced repeatability accuracy due to positional deviations, thus affecting machining quality.

[0004] To improve production efficiency, some machine tools are equipped with independent tool magazines or grinding wheel magazines, which automatically change tools or grinding wheels through mechanical devices. However, these automatic changing devices are mostly single-type storage structures, which cannot accommodate the storage and switching of tools and grinding wheels in the same mechanism. This results in the need to configure two additional changing systems, which occupy a lot of space and have high structural complexity.

[0005] Regarding the changing interface, traditional mechanical locking mechanisms mostly rely on springs or hydraulic drives to clamp and release. These structures are at risk of insufficient clamping force in the event of power failure or pressure loss. At the same time, chips or grinding debris easily adhere to the tool or grinding wheel interface during the switching process. Without effective cleaning measures, this may cause wear or jamming of the interface mating surfaces, thereby affecting the smoothness of the switching and the positioning accuracy.

[0006] Therefore, existing technologies still have shortcomings in terms of automated switching between milling and grinding processes, interface cleaning, protection, and maintaining positioning accuracy. There is an urgent need for a switching mechanism that can quickly and automatically switch between the tool magazine and the grinding wheel magazine within the same spindle, while ensuring high-precision positioning and reliable locking. Utility Model Content

[0007] The purpose of this utility model is to provide a changing mechanism for a metal milling machine tool to solve the problems mentioned in the background art.

[0008] To achieve the above objectives, this utility model provides the following technical solution: a changing mechanism for a metal milling machine tool, comprising a tool magazine, a grinding wheel magazine, a changeover mount, a servo rotary platform, and an automatic locking interface coaxially arranged with the end of the machine tool spindle, arranged sequentially along the same axis of rotation; wherein the tool magazine is located on the first side of the changeover mount, and the grinding wheel magazine is located on the second side of the changeover mount, the two being arranged 180° opposite each other relative to the axis of rotation; the center of the changeover mount coincides with the axis of rotation, and is horizontally connected to the machine tool bed via the lower end of the servo rotary platform. The servo rotary platform drives the conversion mount to rotate around the rotary axis, causing the tool magazine or grinding wheel magazine to rotate sequentially to a position coaxial with the spindle axis. The automatic locking interface is located at the center of the spindle end and includes a conical positioning sleeve fixed coaxially with the spindle and a ring-shaped pull claw assembly. The pull claw assembly is driven by circumferentially distributed electromagnetic actuators, which retract or open radially when the spindle is stationary, thereby locking and releasing the tool or grinding wheel. The servo rotary platform drives the conversion mount to rotate, realizing the automatic switching of the tool magazine and grinding wheel magazine within the same spindle, and maintaining the machining repeatability positioning accuracy at the switching position.

[0009] In one possible implementation, the tool magazine and the grinding wheel magazine are symmetrically arranged at the center of the slewing mount to achieve rotational balance when the slewing mount rotates.

[0010] In one possible implementation, the slewing mounting frame is an integral annular frame; multiple reinforcing ribs with "T"-shaped cross-sections are evenly distributed radially within the frame. Each reinforcing rib has a hollow weight-reducing groove at one end near the rotation axis and a replaceable positioning block at one end near the circumference. This positioning block is fitted with the mounting base of the tool magazine and grinding wheel magazine using a conical-planar composite positioning fit and is secured by pre-tightening screws. The reinforcing ribs form symmetrical mounting surfaces at their relative circumferential positions. The annular frame adopts a double-layer annular plate structure in the axial direction. The inner annular plate is threadedly connected to the flange face of the servo rotary platform, and the outer annular plate is connected to the hinge point of the protective cover. Vibration-damping filling material is provided between the double-layer annular plates to reduce vibration and impact during tool or grinding wheel switching.

[0011] In one possible implementation, the electromagnetic actuators are evenly distributed around the outside of the annular claw assembly along the circumference of the spindle and are of permanent magnet holding type. In the power-off state, the annular claw assembly remains in a radially inward locked position, and the locking force is transmitted to the tool or grinding wheel interface along the spindle axis through the tapered positioning sleeve.

[0012] In one possible implementation, the tapered positioning sleeve has a plurality of radially penetrating air holes spaced apart along the circumferential direction on its tapered surface. The air holes are connected to a compressed air source through pipes hidden inside the spindle. Before the tool or grinding wheel is inserted, compressed air is sprayed radially to remove chips or grinding debris from the interface surface.

[0013] In one possible implementation, a first reversible protective cover is provided on the outside of the tool magazine, and a second reversible protective cover is provided on the outside of the grinding wheel magazine. Both are located on the outer circumferential surface of the reversible mounting bracket, and the reversing axis of the protective cover is parallel to the radial direction of the reversible mounting bracket. They are rotatably connected to the reversible mounting bracket through a linkage mechanism and are controlled to open or close by a servo drive mechanism.

[0014] In one possible implementation, the absolute encoder built into the servo rotary platform is installed at the rotary axis to detect the angular position of the rotary mounting bracket around the rotary axis in real time and feed the detection signal back to the machine tool CNC system.

[0015] In one possible implementation, a central locating pin extending along the spindle axis is provided between the automatic locking interface at the spindle end and the tool holder or wheel holder in the tool magazine or grinding wheel magazine. The front end of the locating pin forms a tapered guide fit with the interface, and its mating surface is provided with a low-friction coating to reduce the insertion force and prevent jamming and eccentricity during the switching process.

[0016] Compared with the prior art, this utility model provides a changing mechanism for a metal milling machine tool, which has the following advantages: A tool changing mechanism for a metal milling and grinding machine tool automatically switches between the tool magazine and grinding wheel magazine within the same spindle by arranging the tool magazine and grinding wheel magazine along the same axis of rotation and using a servo rotary platform to drive the rotating changeover mounting bracket. Combined with an electromagnetic actuation structure of the automatic locking interface and a conical positioning sleeve, it ensures rapid locking and releasing during tool or grinding wheel switching while maintaining machining repeatability and positioning accuracy. This solves the problems of existing machine tools requiring manual tool or grinding wheel changes between milling and grinding operations, low switching efficiency, and difficulty in guaranteeing positioning accuracy. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the main structure of the present utility model; Figure 2 This is a schematic diagram of the reversing mounting bracket of this utility model; Figure 3 This is a schematic diagram of the structure of the electromagnetic actuator of this utility model; Figure 4 This is a structural diagram of the first and second reversible shields of this utility model; Figure 5 This is a cross-sectional view of the conical positioning sleeve of this utility model.

[0018] In the diagram: 1. Tool magazine; 2. Grinding wheel magazine; 3. Rotary mounting bracket; 4. Servo rotary platform; 5. Automatic locking interface. 6. Machine tool spindle; 51. Conical positioning sleeve; 52. Ring claw assembly; 53. Electromagnetic actuator; 31. Reinforcing rib; 311. Hollow weight-reducing groove; 312. Replaceable positioning block; 33. Vibration-damping filling material; 511. Air hole; 12. First flip-up protective cover; 22. Second flip-up protective cover; 121. Linkage mechanism; 41. Absolute encoder; 55. Center positioning pin. Detailed Implementation

[0019] like Figures 1-5 As shown, this utility model provides a technical solution: including a tool magazine 1, a grinding wheel magazine 2, a rotary conversion mount 3, a servo rotary platform 4, and an automatic locking interface 5 coaxially arranged with the end of the machine tool spindle 6, arranged sequentially along the same axis of rotation; wherein, the tool magazine 1 is located on the first side of the rotary conversion mount 3, and the grinding wheel magazine 2 is located on the second side of the rotary conversion mount 3, and the two are arranged opposite each other at 180° relative to the axis of rotation; the center of the rotary conversion mount 3 coincides with the axis of rotation, and is horizontally connected to the machine tool bed through the lower end of the servo rotary platform 4, and the servo rotary platform 4 drives the rotary conversion mount 3 to rotate around the axis of rotation. The axis rotates, causing tool magazine 1 or grinding wheel magazine 2 to sequentially rotate to a position coaxial with the axis of spindle 6. The automatic locking interface 5, located at the center of the end of spindle 6, includes a conical positioning sleeve 51 fixed coaxially with spindle 6 and a ring-shaped puller assembly 52. ​​The puller assembly 52 is driven by circumferentially distributed electromagnetic actuators 53, retracting or opening radially when spindle 6 is stationary, thereby locking and releasing the tool or grinding wheel. The servo rotary platform 4 drives the rotary conversion mount 3 to rotate, achieving automatic switching between tool magazine 1 and grinding wheel magazine 2 within the same spindle 6, maintaining machining repeatability and positioning accuracy at the switching position. When the machine tool needs to change machining tools, the CNC system first issues a command to drive the servo rotary platform 4 to begin operation. The servo rotary platform 4 drives the rotary conversion mount 3 to rotate smoothly along the rotation axis. During rotation, tool magazine 1 and grinding wheel magazine 2 sequentially pass through different angular positions until the target magazine position is coaxial with the axis of spindle 6. Simultaneously, spindle 6 remains stationary, and the automatic locking interface 5 enters the unlocking preparation stage. Upon receiving a control signal, the electromagnetic actuator 53, located at the center of the spindle 6 end, rapidly drives the annular puller assembly 52 to open radially, releasing the lock on the current tool or grinding wheel. Subsequently, the target tool or grinding wheel, guided by positioning, inserts into the tapered positioning sleeve 51. Under control, the puller assembly 52 retracts radially, firmly clamping and locking the tool or grinding wheel. Throughout the entire changeover process, the rotation, unlocking, insertion, and locking actions are seamlessly connected in a predetermined sequence, ensuring smooth switching, precise positioning, and immediate restoration to the machining state after the changeover.

[0020] In one possible implementation, the tool magazine 1 and the grinding wheel magazine 2 are symmetrically arranged at the center of the rotary conversion frame 3 to achieve rotational balance when the rotary conversion frame 3 rotates. When the servo rotary platform 4 starts and drives the rotary conversion frame 3 to rotate, the tool magazine 1 and the grinding wheel magazine 2 on both sides form mutually balancing inertial torques during rotation due to their symmetrical arrangement. The centrifugal force during rotation is structurally canceled out, allowing the rotary conversion frame 3 to maintain stable rotation and avoiding vibration or swaying caused by uneven loading. Throughout the switching process, the driving force of the servo rotary platform 4 is transmitted more efficiently under the action of the balancing structure, reducing the time for rotational acceleration and deceleration, and reducing the impact on bearings and transmission components. The symmetrical arrangement achieves rotational balance, significantly reducing inertial unevenness and vibration during rotation, which helps to extend the service life of the servo rotary platform 4 and its mating components, and improves the smoothness and accuracy of the switching process. At the same time, the balancing structure can also reduce energy consumption during high-speed switching and improve the overall response speed of the machine tool.

[0021] Preferably, the rotary conversion frame 3 is an integral annular frame. Multiple reinforcing ribs 31 with "T"-shaped cross-sections are evenly distributed radially within this frame. Each reinforcing rib 31 has a hollow weight-reducing groove 311 at one end near the rotation axis and a replaceable positioning block 312 at one end near the circumference. This positioning block 312 is fitted with the mounting bases of the tool magazine 1 and grinding wheel magazine 2 using a conical-planar composite positioning fit and is secured with pre-tightened screws. The reinforcing ribs 31 form symmetrical mounting surfaces at their relative circumferential positions. The annular frame adopts a double-layer annular plate structure in the axial direction. The inner annular plate is threaded to the flange face of the servo rotary platform 4, and the outer annular plate is connected to the hinge point of the protective cover. Vibration-damping filling material 33 is provided between the double-layer annular plates to reduce vibration and impact during tool or grinding wheel switching. When the servo rotary platform 4 drives the rotary conversion frame 3 to rotate and switch, the integral annular frame structure provides rigid support through the evenly distributed "T"-shaped cross-section reinforcing ribs 31. During rotation, the weight-reducing groove 311 lowers the moment of inertia, while the positioning block 312 achieves precise positioning during the assembly of the tool magazine 1 or the grinding wheel magazine 2 through a conical-planar composite fit. The double-layer ring plate structure absorbs impact and vibration through the vibration-damping filling material 33 in the middle during rotation and switching, ensuring the stability and positioning accuracy of the rotary mounting frame 3 throughout the entire motion cycle. This structure, while maintaining high rigidity, reduces the system's moment of inertia through the weight-reducing groove 311, thus accelerating the response speed of the servo rotary platform 4. The double-layer ring plate, combined with the vibration-damping filling material 33, effectively suppresses vibration and impact during switching, improving mounting accuracy and operational stability, and extending the service life of the tool magazine, grinding wheel magazine, and other connecting components.

[0022] Alternative implementation methods The cross-sectional shape of the reinforcing rib 31 can be adjusted to an I-shaped, cross-shaped, or box-shaped cross-section according to the load requirements; the weight reduction groove 311 can adopt a honeycomb lightweight structure; the positioning block 312 can be made of ceramic or hard alloy material to enhance wear resistance; the vibration isolation filling material 33 can be replaced with a polymer damping layer or a metal elastic vibration isolation sheet.

[0023] Preferably, the electromagnetic actuators 53 are evenly distributed around the outer side of the annular pull claw assembly 52 along the circumference of the spindle 6, and are of permanent magnet holding type. In the power-off state, the annular pull claw assembly 52 maintains a radially retracted locking position, and the locking force is transmitted axially along the spindle 6 to the tool or grinding wheel interface via the conical positioning sleeve 51. During tool switching, the electromagnetic actuators 53 receive an unlocking signal from the CNC system, quickly demagnetize, and drive the pull claw assembly 52 to open radially, releasing the tool or grinding wheel. After switching is complete and a new tool or grinding wheel is installed, the electromagnetic actuators 53 are remagnetized, the pull claw assembly 52 retracts radially, and the locking force is transmitted to the interface via the conical positioning sleeve 51, achieving a secure lock. Even in the power-off state, the permanent magnet holding structure can maintain the locking position, ensuring the safety of the tool and the protection of the workpiece in the event of a sudden power outage. The permanent magnet holding structure ensures locking safety in the event of a power outage, preventing accidental dislodgement of the tool or grinding wheel; at the same time, it reduces the dependence of the locking system on continuous power supply, reducing energy consumption. The radial locking fit tapered positioning sleeve 51 improves the coaxiality and vibration resistance of the interface.

[0024] Preferably, the tapered positioning sleeve 51 has multiple radially penetrating air holes 511 spaced at intervals along the circumference on its tapered surface. These air holes 511 are connected to a compressed air source via pipes hidden inside the spindle 6. Before the tool or grinding wheel is inserted, compressed air is sprayed radially to remove chips or grinding debris from the interface surface. Before the changeover begins, the CNC system sends a command to the compressed air source, which then delivers compressed air to the air holes 511 on the tapered positioning sleeve 51 through pipes inside the spindle 6. The air holes 511 uniformly spray high-speed airflow radially, blowing away chips, grinding debris, and minute impurities from the interface surface, creating a clean clamping surface. Subsequently, the tool or grinding wheel is inserted into the interface, ensuring tight contact between the mating surfaces, thereby maintaining high-precision positioning and stable locking.

[0025] The vent 511 can be designed for oblique spraying to enhance cleaning effect; the compressed air source can be replaced with a high-pressure nitrogen source to reduce oxidation; and a pulse spray mode can be added to the jet control to further improve cleaning efficiency.

[0026] Preferably, a first reversible protective cover 12 is provided on the outside of the tool magazine 1, and a second reversible protective cover 22 is provided on the outside of the grinding wheel magazine 2. Both are located on the outer circumferential surface of the reversible mounting bracket 3, and the reversing axis of the protective cover is parallel to the radial direction of the reversible mounting bracket 3. They are rotatably connected to the reversible mounting bracket 3 through a linkage mechanism 121, and are controlled to open or close by a servo drive mechanism.

[0027] Before the tool change begins, the servo drive mechanism receives a command, and the drive linkage 121 rotates the protective cover 12 or 22 along the flip axis to open, exposing the interface position of the tool magazine 1 or grinding wheel magazine 2. After the change is completed, the servo drive mechanism reverses its action to close and lock the protective cover, preventing chips, coolant, or abrasive particles from entering the tool magazine or grinding wheel magazine during machining. The protective cover structure effectively prevents contaminants from the machining environment from entering the magazine, extending the life of the tools and grinding wheels; the automatic opening and closing of the servo drive improves the efficiency of the tool change and reduces the need for manual intervention.

[0028] Preferably, the absolute encoder 41 built into the servo rotary platform 4 is installed at the rotation axis to detect the angular position of the rotary conversion mount 3 around the rotation axis in real time and feed the detection signal back to the machine tool CNC system. During rotation switching, the absolute encoder 41 records the angular position of the rotary conversion mount 3 in real time and continuously feeds the signal back to the CNC system. The CNC system precisely controls the start, stop, and positioning of the servo rotary platform 4 based on the feedback information to ensure that the target tool magazine 1 or grinding wheel magazine 2 is accurately stopped in the coaxial position of the spindle 6.

[0029] Preferably, a center locating pin 55 extending along the axis of the spindle 6 is provided between the automatic locking interface 5 at the spindle end and the tool holder or wheel holder in the tool magazine 1 or grinding wheel magazine 2. The front end of the center locating pin 55 forms a conical guide engagement with the interface, and its mating surface is coated with a low-friction coating to reduce insertion force and prevent jamming and eccentricity during the switching process. During the changing process, when the tool or grinding wheel moves along the axis of the spindle 6 and approaches the interface, the center locating pin 55 first contacts its guide hole. The conical guide automatically corrects minor deviations, ensuring smooth centering during clamping. The low-friction coating reduces insertion force and prevents jamming or eccentricity caused by excessive friction, thereby ensuring smooth completion of the locking action. The center locating pin 55 significantly improves the centering accuracy of the clamping, reduces mechanical impact and component wear during the switching process, and enhances the reliability and service life of the entire changing system.

[0030] Alternative or modified implementation methods The locating pin 55 can be telescopic to accommodate tool holders or wheel holders of different lengths; the guide cone can be replaced with a spherical guide to accommodate minor deviations in different directions; the low-friction coating can be titanium nitride, DLC, or PTFE coating.

[0031] Working principle: During the operation of the changing mechanism, when the machine tool needs to switch between milling and grinding tasks, the CNC system first issues a changing command according to the machining program. The servo rotary platform 4 starts, driving the rotary changeover mount 3, which is mounted coaxially with it, to rotate smoothly along the rotary axis. Since the tool magazine 1 and the grinding wheel magazine 2 are 180° opposite each other and centrally symmetrically arranged on the rotary changeover mount 3, the system maintains dynamic balance throughout the rotation process, avoiding vibration and off-center load impact.

[0032] As the rotary mounting bracket 3 rotates, the absolute encoder 41 detects its angular position in real time and continuously feeds back the precise data to the CNC system to ensure that the target magazine is accurately positioned. When the target tool magazine 1 or grinding wheel magazine 2 rotates to be coaxial with the spindle 6, the protective cover 12 or 22 flips open under the action of the servo drive mechanism, exposing the interface position of the tool or grinding wheel to be replaced.

[0033] At this time, the spindle 6 remains stationary, and the automatic locking interface 5 enters the unlocking stage. The electromagnetic actuators 53 distributed on the outside of the annular puller assembly 52 receive the unlocking signal and drive the puller assembly 52 to open radially, releasing the clamping force of the current tool or grinding wheel. If there are chips or grinding debris at the interface, the air holes 511 on the conical positioning sleeve 51 will spray compressed air in advance to clean the mating surfaces.

[0034] Subsequently, the new tool or grinding wheel moves along the axis of the spindle 6 to approach the interface, first contacting the center locating pin 55. Its tapered guide surface automatically corrects minor positional deviations, and the low-friction coating reduces the insertion force, preventing jamming and eccentricity. After the tool or grinding wheel is fully inserted, the electromagnetic actuator 53 is re-energized, driving the pull claw assembly 52 to retract radially, transmitting the locking force to the interface through the tapered locating sleeve 51, achieving secure clamping.

[0035] Throughout the switching process, the overall annular frame structure of the switching mount 3 and the "T"-shaped cross-section reinforcing rib 31 provide stable structural support, the weight reduction groove 311 reduces the moment of inertia, and the vibration isolation filling material 33 effectively absorbs the impact during the switching moment. After locking is completed, the protective cover 12 or 22 automatically closes, and the machine tool immediately enters the next processing step, realizing high-precision, fast, and automatic switching of the cutting tool and grinding wheel on the same spindle.

[0036] The present invention has been described in detail above. However, modifications or improvements can be made to it, which will be obvious to those skilled in the art. Therefore, any modifications or improvements that do not depart from the spirit of the present invention are within the protection scope of the present invention.

Claims

1. A changing mechanism for a metal milling machine tool, characterized in that, The system includes a tool magazine (1), a grinding wheel magazine (2), a rotary mounting bracket (3), a servo rotary platform (4), and an automatic locking interface (5) coaxially arranged with the end of the machine tool spindle (6), arranged sequentially along the same axis of rotation. The tool magazine (1) is located on the first side of the rotary mounting bracket (3), and the grinding wheel magazine (2) is located on the second side of the rotary mounting bracket (3). The two are arranged opposite each other at 180° relative to the axis of rotation. The center of the rotary mounting bracket (3) coincides with the axis of rotation and is horizontally connected to the machine tool bed through the lower end of the servo rotary platform (4). The servo rotary platform (4) drives the rotary mounting bracket (3) to rotate around the axis of rotation, so that the tool magazine (1) or the grinding wheel magazine (2) rotates sequentially to a position coaxial with the axis of the spindle (6). The automatic locking interface (5) is located at the center of the end of the spindle (6) and includes a conical positioning sleeve (51) fixed coaxially with the spindle (6) and a ring-shaped pull claw assembly (52). The pull claw assembly (52) is driven by a circumferentially distributed electromagnetic actuator (53) to retract or open radially when the spindle (6) is stationary, thereby locking and releasing the tool or grinding wheel. The servo rotary platform (4) drives the rotary conversion mount (3) to rotate, thereby realizing the automatic switching of the tool magazine (1) and the grinding wheel magazine (2) within the same spindle (6) and maintaining the machining repeatability positioning accuracy at the switching position.

2. The changing mechanism according to claim 1, characterized in that, The tool magazine (1) and the grinding wheel magazine (2) are symmetrically arranged at the center of the rotary conversion frame (3) to achieve rotational balance when the rotary conversion frame (3) rotates.

3. The changing mechanism according to claim 1, characterized in that, The rotating mounting bracket (3) is an integral ring frame; multiple reinforcing ribs (31) with "T" shaped cross sections are evenly distributed radially inside the frame. The reinforcing ribs (31) have a hollow weight-reducing groove (311) at one end near the rotation axis and a replaceable positioning block (312) at one end near the circumference. The positioning block (312) is fitted with the mounting base of the tool magazine (1) and the grinding wheel magazine (2) using a conical-plane composite positioning fit and is locked by pre-tightening screws; the reinforcing ribs (31) form symmetrical mounting surfaces at relative positions on the circumference; The ring frame adopts a double-layer ring plate structure in the axial direction, with the inner ring plate connected to the servo rotary platform ( 4) The flange face is threaded, the outer ring plate is connected to the hinge point of the protective cover, and vibration isolation filling material (33) is provided between the double ring plates to reduce the vibration impact when the tool or grinding wheel is switched.

4. The changing mechanism according to claim 1, characterized in that, The electromagnetic actuator (53) is evenly distributed around the outside of the annular claw assembly (52) along the circumference of the main shaft (6) and is a permanent magnet holding structure. In the power-off state, the annular claw assembly (52) maintains a locking position that is radially retracted. The locking force is transmitted along the main shaft (6) axially through the conical positioning sleeve (51) to the tool or grinding wheel interface.

5. The changing mechanism according to claim 1, characterized in that, The conical positioning sleeve (51) has multiple radially penetrating air holes (511) spaced apart along the circumferential direction on its conical surface. The air holes (511) are connected to a compressed air source through a pipe hidden inside the spindle (6). Before the tool or grinding wheel is inserted, compressed air is sprayed radially to remove chips or grinding debris from the interface surface.

6. The changing mechanism according to claim 1, characterized in that, The tool magazine (1) is provided with a first reversible protective cover (12) on the outside, and the grinding wheel magazine (2) is provided with a second reversible protective cover (22) on the outside. Both are located on the outer circumferential surface of the reversible mounting frame (3), and the reversing axis of the protective cover is parallel to the radial direction of the reversible mounting frame (3). They are rotatably connected to the reversible mounting frame (3) through a linkage mechanism (121) and are controlled to open or close by a servo drive mechanism.

7. The changing mechanism according to claim 1, characterized in that, The absolute encoder (41) built into the servo rotary platform (4) is installed at the rotary axis to detect the angular position of the rotary mounting bracket (3) around the rotary axis in real time and feed the detection signal back to the machine tool CNC system.

8. The changing mechanism according to claim 1, characterized in that, A central positioning pin (55) extending along the axis of the spindle (6) is provided between the automatic locking interface (5) at the spindle end and the tool holder or wheel holder in the tool magazine (1) or grinding wheel magazine (2). The front end of the positioning pin (55) forms a conical guide fit with the interface, and its mating surface is provided with a low friction coating to reduce the insertion force and prevent jamming and eccentricity during the switching process.

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