Double servo automatic tool changing mechanism for numerical control machine tool

Abstract

The application is suitable for the technical field of automatic tool changing device of numerical control machine tool, and provides a double-servo automatic tool changing mechanism for numerical control machine tool, which comprises a connecting frame, mounting pieces, a transmission mechanism and a mounting mechanism, two mounting pieces are respectively arranged on the two sides of the connecting frame, the transmission mechanism is arranged in the middle of the connecting frame and is used for providing axial movement power and rotary power to the connecting frame respectively; the application sets the first servo motor and the second servo motor which are independent of each other, and the rotary action and the axial extension action required in the tool changing process of the mechanical arm are respectively driven by different power sources. The first servo motor provides rotary power to the output shaft rotating sleeve through a gear transmission pair, the second servo motor provides axial power to the output shaft through a transmission wheel, a transmission belt and a ball screw pair, so that the tool pulling distance, the tool mounting distance, the rotary angle, the rotary speed and the pause time between different actions can be respectively set according to the actual working requirements of the machine tool.

Description

Technical Field

[0001] This invention relates to the technical field of automatic tool changers for CNC machine tools, and more specifically to a dual-servo automatic tool changer for CNC machine tools. Background Technology

[0002] When CNC machine tools continuously process different operations, they typically require an automatic tool changer to exchange tools between the machine tool spindle and the tool magazine. An automatic tool changer generally needs to sequentially perform actions such as moving the robotic arm to the tool changing position, disengaging the tool from the spindle and tool magazine, rotating the robotic arm to exchange the tool, and re-inserting the exchanged tool into its corresponding position. Therefore, the tool changer needs to be capable of both axial movement along the tool loading / unloading direction and rotating the robotic arm at a certain angle.

[0003] In traditional tool changing mechanisms, axial and rotary movements are usually linked by cams, Geneva wheels, compound linkages, or mechanical transmission mechanisms with predetermined motion curves. Although such structures can complete tool changing according to a fixed action cycle, they have a large number of internal transmission parts and strong mechanical coupling between different actions. When the machine tool specifications, tool weight, spindle position, or tool changing stroke changes, the mechanical transmission relationship needs to be readjusted, making the debugging process relatively complex. At the same time, after the cam or compound transmission structure has been subjected to frequent start-stop loads for a long time, gaps are easily generated between the transmission pairs, causing cumulative errors in the axial and rotary positions of the robotic arm.

[0004] Using two independent servo drive sources to control the axial and rotary motions respectively can improve the adjustability of the tool changing action; however, both motions must act simultaneously on the same output component. If the rotary drive mechanism is rigidly fixed to the output shaft, the axial extension and retraction of the output shaft is easily restricted by the rotary transmission components. If only a regular sliding sleeve connection is used, it is difficult to stably transmit a large rotational torque. On the other hand, when the ball screw pair drives the output shaft to move axially, its screw nut usually needs to maintain circumferential positioning, while the output shaft needs to rotate independently during tool changing. Therefore, it is also necessary to solve the motion decoupling problem between the linear force transmission part of the screw nut and the rotating part of the output shaft. Summary of the Invention

[0005] This invention provides a dual-servo automatic tool changer for CNC machine tools, aiming to solve the problems of existing automatic tool changers having large space requirements, inconvenient axial movement and rotation movements that are not easy to adjust separately, and inconvenient transmission component connection positions for anti-deflection locking and disassembly and maintenance.

[0006] The present invention is implemented as follows: a dual-servo automatic tool changer for CNC machine tools includes a connecting frame, mounting parts, a transmission mechanism, and a mounting mechanism. The two mounting parts are respectively disposed on both sides of the connecting frame, and the transmission mechanism is disposed in the middle of the connecting frame, for providing axial movement power and rotation power to the connecting frame respectively.

[0007] The transmission mechanism includes a gearbox, a first servo motor, a second servo motor, a guide cylinder, a drive gear, an output shaft, two transmission wheels, a transmission belt, a driven gear, a lead screw, an output shaft limiting ring, a lead screw nut, an output shaft positioning ring, an output shaft rotating sleeve, and a flat key.

[0008] Preferably, the output shaft is slidably arranged along the axial direction of the guide cylinder, and the lower end of the output shaft is connected to the connecting frame, so that when the output shaft moves axially, it can drive the connecting frame and the mounting parts on both sides of the connecting frame to move synchronously, and when the output shaft rotates, it can drive the connecting frame and the mounting parts to rotate synchronously.

[0009] Preferably, the first servo motor constitutes a rotary drive unit, the output end of the first servo motor is connected to the driving gear, the driving gear meshes with the driven gear, the driven gear is sleeved on the outside of the output shaft rotating sleeve and forms a circumferential fixed connection with the output shaft rotating sleeve, so that when the driven gear rotates, it can drive the output shaft rotating sleeve to rotate synchronously.

[0010] Preferably, the output shaft rotating sleeve is sleeved on the outside of the output shaft and is rotatably supported on the lower part of the guide cylinder by a bearing. The output shaft rotating sleeve can rotate circumferentially relative to the guide cylinder, while its axial position is restricted relative to the guide cylinder.

[0011] Preferably, the inner side of the output shaft rotating sleeve is provided with two flat keys, which are respectively disposed on opposite sides of the inner side of the output shaft rotating sleeve; the outer side of the output shaft is provided with axial keyways corresponding to the two flat keys, and each flat key is slidably disposed in the corresponding axial keyway. Thus, the flat keys allow the output shaft to move axially relative to the output shaft rotating sleeve, and at the same time, when the output shaft rotating sleeve rotates, the flat keys cooperate with the sidewalls of the axial keyways to transmit circumferential force to the output shaft.

[0012] Preferably, the second servo motor constitutes a telescopic drive unit, and two transmission wheels are respectively connected to the output end of the second servo motor and one end of the lead screw. The transmission belt is sleeved on the outside of the two transmission wheels. The lead screw is arranged along the axial direction of the output shaft and is rotatably connected to the guide cylinder. The lead screw nut is threadedly connected to the outside of the lead screw. The lead screw and the lead screw nut together constitute a ball screw pair.

[0013] Preferably, the lead screw nut and the output shaft limiting ring are axially linked. The output shaft limiting ring is sleeved on the outside of the output shaft. Guide limiting keys are provided on both sides of the output shaft limiting ring. Guide grooves extending along the axial direction of the output shaft are provided on both sides of the guide cylinder. The two guide limiting keys are slidably disposed in the corresponding guide grooves to restrict the output shaft limiting ring from rotating circumferentially with the lead screw nut and to guide the axial movement of the output shaft limiting ring.

[0014] Preferably, the output shaft positioning ring is disposed on the outside of the output shaft and forms an axial positioning connection with the output shaft. A rotating support structure capable of withstanding axial load is provided between the output shaft positioning ring and the output shaft limiting ring, so that the output shaft limiting ring can transmit axial force to the output shaft positioning ring, while allowing the output shaft positioning ring to rotate relative to the output shaft limiting ring.

[0015] Preferably, the rotating support structure can be a rolling bearing, a thrust bearing, or a bearing assembly capable of simultaneously performing axial positioning and relative rotation functions. One side of the bearing forms an axial positioning ring with the output shaft limiting ring, and the other side forms an axial positioning ring with the output shaft positioning ring. Thus, when the lead screw nut moves along the lead screw, it sequentially drives the output shaft limiting ring, the rotating support structure, and the output shaft positioning ring to move axially, ultimately causing the output shaft to extend and retract synchronously. When the output shaft rotates, the output shaft positioning ring can rotate synchronously with the output shaft, and the output shaft limiting ring and the lead screw nut do not need to rotate with the output shaft.

[0016] Preferably, the installation mechanism includes a rotating component, a first anti-deflection ring, a through groove, a second anti-deflection ring, an installer, a worm gear, a worm wheel, a maintenance rod, a guide rail, a limit rod, a transmission plate, a support, a locking rod, and a connecting groove. The installer is located at the lower connection position of the transmission mechanism and is used for installation and limiting of the corresponding connection position.

[0017] Compared with related technologies, the dual-servo automatic tool changer for CNC machine tools provided by the present invention has the following beneficial effects: This invention utilizes independent first and second servo motors to drive the rotary and axial extension / retraction movements required during tool changing in a robotic arm via different power sources. The first servo motor provides rotary power to the output shaft rotating sleeve through a gear transmission pair, while the second servo motor provides axial power to the output shaft through a transmission wheel, transmission belt, and ball screw pair. This allows the tool removal distance, tool loading distance, rotary angle, rotary speed, and pause times between different movements to be individually set according to the actual working requirements of the machine tool, reducing the adjustment limitations caused by the fixed mechanical motion curve of traditional cam-type tool changing mechanisms.

[0018] This invention provides a flat key inside the output shaft rotating sleeve and an axial keyway extending axially on the outside of the output shaft. This allows the flat key to function as both a guide during the extension and retraction of the output shaft and a circumferential force transmission component when the output shaft rotating sleeve rotates. When the second servo motor drives the output shaft axially, the output shaft can slide freely along the flat key without requiring axial displacement of the driven gear and the output shaft rotating sleeve. When the first servo motor performs rotary drive, the driven gear, the output shaft rotating sleeve, and the flat key form a continuous torque transmission path, thus balancing the axial freedom and circumferential driving capability of the output shaft.

[0019] This invention establishes a telescopic force transmission path through a lead screw, lead screw nut, output shaft limiting ring, output shaft positioning ring, and rotating support structure. Guide limiting keys are provided on both sides of the output shaft limiting ring to ensure that the axial displacement generated by the lead screw nut is stably transmitted to the output shaft. After the guide limiting keys cooperate with the guide grooves on both sides of the guide cylinder, they can restrict the circumferential rotation of the lead screw nut and output shaft limiting ring with the lead screw, and provide linear guidance for the entire telescopic assembly. The axial support structure that allows relative rotation between the output shaft positioning ring and the output shaft limiting ring prevents the transmission of additional torque from the output shaft rotational motion to the ball screw pair, thus achieving mechanical decoupling between the telescopic drive and the rotary drive.

[0020] This invention utilizes a first servo motor to perform the rotary motion required for tool changing, and a second servo motor to perform the axial motion required for tool removal and loading. Two mounting components respectively carry the spindle-side tool and the tool magazine-side tool. After the output shaft removes the tool, it can directly perform rotary tool changing without changing the connection state of the axial drive mechanism. After the tool change, the second servo motor drives the output shaft in reverse to load the tool, forming a continuous automatic tool changing process. Simultaneously, the gear transmission pair achieves high rotational stiffness, and the ball screw pair provides good axial positioning accuracy, which helps improve the repeatability and operational stability of the robotic arm under high-speed tool changing conditions. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the overall structure of the present invention; Figure 2 This is a schematic diagram of the overall structure from another perspective of the present invention; Figure 3 This is an exploded structural diagram of the present invention; Figure 4 for Figure 3 A magnified view of a section at point A in the middle; Figure 5 This is a partial structural schematic diagram of the transmission mechanism of the present invention; Figure 6 This is an exploded structural diagram from another perspective of the present invention; Figure 7This is a schematic diagram of the structure of the first anti-deflection ring part of the present invention; Figure 8 For the present invention Figure 7 Enlarged view of a portion of point B in the middle; Figure 9 This is a schematic diagram of the output shaft positioning ring portion of the present invention; Figure 10 This is a schematic diagram of the screw nut portion of the present invention; Figure 11 For the present invention Figure 10 Enlarged view of point C.

[0022] In the diagram: 1. Connecting frame; 2. Mounting component; 3. Transmission mechanism; 4. Mounting mechanism; 301. Gearbox; 302. First servo motor; 303. Second servo motor; 304. Guide cylinder; 305. Drive gear; 307. Output shaft; 308. Transmission wheel; 309. Transmission belt; 310. Driven gear; 311. Lead screw; 312. Output shaft limit ring; 313. Lead screw nut; 314. 315. Output shaft positioning ring; 316. Output shaft rotating sleeve; 407. Flat key; 408. Rotating component; 409. First anti-deflection ring; 4000. Through groove; 401. Second anti-deflection ring; 4000. Installer; 401. Worm gear; 402. Worm wheel; 403. Inspection rod; 404. Guide rail; 415. Limiting rod; 416. Transmission plate; 417. Support; 418. Locking rod; 419. Connecting groove. Detailed Implementation

[0023] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs; the terminology used herein in the specification of the application is for the purpose of describing particular embodiments only and is not intended to be limiting of the application; the terms "comprising" and "having," and any variations thereof, in the specification, claims, and foregoing drawings of this application are intended to cover non-exclusive inclusion. The terms "first," "second," etc., in the specification, claims, or foregoing drawings of this application are used to distinguish different objects, not to describe a particular order.

[0024] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0025] Example like Figures 1 to 11As shown, this embodiment provides a dual-servo automatic tool changer for CNC machine tools, including a connecting frame 1, two mounting members 2, a transmission mechanism 3, and a mounting mechanism 4. The two mounting members 2 are respectively disposed at both ends of the connecting frame 1, which connects the two mounting members 2 to the output shaft 307 of the transmission mechanism 3. One mounting member 2 engages with the tool on the machine tool spindle side, and the other mounting member 2 engages with the tool magazine side. When the connecting frame 1 rotates, the two mounting members 2 can synchronously change position around the axis of the output shaft 307, thereby realizing the position exchange between the spindle-side tool and the tool magazine-side tool.

[0026] Mounting component 2 can adopt a tool clamping structure commonly used in CNC machine tool tool changing robotic arms, with its clamping end engaging with the tool changing groove or corresponding positioning position on the outside of the tool holder. During tool changing, mounting component 2 mainly provides radial support and follow-up transport for the tool. Driven by mounting component 2, the tool is pulled out and inserted along the axis of the spindle or tool magazine sleeve. In this embodiment, the shape of the specific clamping opening of mounting component 2 is not limited and can be set accordingly based on different tool holder specifications.

[0027] In this embodiment, the transmission mechanism 3 includes a gearbox 301, a first servo motor 302, a second servo motor 303, a guide cylinder 304, a drive gear 305, an output shaft 307, two transmission wheels 308, a transmission belt 309, a driven gear 310, a lead screw 311, an output shaft limiting ring 312, a lead screw nut 313, an output shaft positioning ring 314, an output shaft rotating sleeve 315, and a flat key 316.

[0028] The first servo motor 302 controls the rotation of the output shaft 307 and the connecting frame 1, and the second servo motor 303 controls the axial extension and retraction of the output shaft 307 and the connecting frame 1. The two servo motors are respectively connected to the control system of the CNC machine tool or a corresponding servo driver, enabling the two movements to be executed according to a pre-set sequence. Preferably, both the first servo motor 302 and the second servo motor 303 have encoders to provide feedback on the rotation angle and extension / retraction position, respectively, allowing the control system to determine whether each movement has reached the predetermined position.

[0029] like Figures 5 to 7 As shown, the first servo motor 302 is mounted on one side of the gearbox 301. The output end of the first servo motor 302 is fixedly connected to the drive gear 305, and the drive gear 305 meshes with the driven gear 310. After the first servo motor 302 is started, the drive gear 305 rotates with the output shaft of the first servo motor 302 and transmits power to the driven gear 310 through tooth surface meshing.

[0030] Driven gear 310 is sleeved on the outside of output shaft rotating sleeve 315. Driven gear 310 and output shaft rotating sleeve 315 are connected by a key, and the axial relative movement between them is restricted by a shoulder, retaining ring, locking nut or equivalent axial limiting structure, so that driven gear 310 and output shaft rotating sleeve 315 maintain a reliable circumferential synchronous relationship. When the first servo motor 302 drives driven gear 310 to rotate, driven gear 310 can directly drive output shaft rotating sleeve 315 to rotate around the axis of output shaft 307.

[0031] The output shaft rotating sleeve 315 is disposed at the lower part of the guide cylinder 304 and sleeved on the outside of the output shaft 307. A rolling bearing is provided between the output shaft rotating sleeve 315 and the guide cylinder 304. The outer ring of the rolling bearing is positioned relative to the guide cylinder 304, and the inner ring of the rolling bearing cooperates with the output shaft rotating sleeve 315, so that the output shaft rotating sleeve 315 can rotate stably relative to the guide cylinder 304. At the same time, the bearing end face, shaft shoulder or retaining ring provides axial limit for the output shaft rotating sleeve 315, so that the output shaft rotating sleeve 315 mainly rotates during normal operation and does not move axially with the output shaft 307.

[0032] Two flat keys 316 are arranged opposite each other on the inner side of the output shaft rotating sleeve 315. The two flat keys 316 are locked to the inner side of the output shaft rotating sleeve 315 by screws, keyway fitting or other fixing structures. The outer side of the output shaft 307 is provided with elongated keyways extending along the axial direction of the output shaft 307, corresponding to the two flat keys 316. A part of the flat key 316 is located inside the output shaft rotating sleeve 315, and the other part extends into the corresponding elongated keyway.

[0033] The flat key 316 and the elongated keyway form a sliding fit along the axial direction. Therefore, when the output shaft 307 performs telescopic movement, the output shaft 307 can slide relative to the output shaft rotating sleeve 315 along the length direction of the flat key 316, and the output shaft rotating sleeve 315 does not need to move axially with the output shaft 307. Thus, the flat key 316 primarily serves as an auxiliary guide during the telescopic process of the output shaft 307.

[0034] When the first servo motor 302 drives the driven gear 310 and the output shaft rotating sleeve 315 to rotate, the sides of the two flat keys 316 respectively abut against the sidewalls of the corresponding elongated keyways of the output shaft 307. The circumferential torque generated by the output shaft rotating sleeve 315 is transmitted to the output shaft 307 through the flat keys 316, causing the output shaft 307 to rotate synchronously with the output shaft rotating sleeve 315. Thus, the flat keys 316 also constitute a circumferential force transmission component between the output shaft rotating sleeve 315 and the output shaft 307.

[0035] The above structure allows the same set of flat keys 316 to simultaneously allow axial sliding and transmit circumferential torque, enabling the output shaft 307 to perform axial extension and retraction in the vertical or horizontal directions without disengaging the rotary transmission connection. Therefore, after the output shaft 307 completes the tool-pulling action, the rotary connection does not need to be re-established through a clutch or other switching components, and the first servo motor 302 can directly drive the output shaft 307 to perform tool-changing rotation.

[0036] The diameter of the driving gear 305 can be smaller than that of the driven gear 310, so that the higher speed output by the first servo motor 302 is appropriately reduced after passing through the gear transmission, while increasing the torque transmitted to the output shaft rotating sleeve 315 to meet the load requirements when the connecting frame 1 carries two tools for rotational exchange.

[0037] The second servo motor 303 is fixedly mounted on one side of the guide cylinder 304, and the output shaft of the second servo motor 303 is arranged basically parallel to the lead screw 311. One of the two transmission wheels 308 is fixedly connected to the output end of the second servo motor 303, and the other is fixedly connected to one end of the lead screw 311. The transmission belt 309 is sleeved on the outside of the two transmission wheels 308.

[0038] The transmission wheel 308 is preferably a synchronous pulley, and the transmission belt 309 is preferably a synchronous belt, so that the rotation of the output end of the second servo motor 303 can be transmitted to the lead screw 311 according to a determined transmission ratio, and reduce the slippage that may be caused by ordinary friction belts. When the second servo motor 303 starts, the corresponding transmission wheel 308 drives the transmission belt 309 to run, and the transmission belt 309 further drives another transmission wheel 308 connected to the lead screw 311 to rotate, so that the lead screw 311 rotates around its own axis.

[0039] The lead screw 311 is axially arranged along the output shaft 307. Both ends of the lead screw 311 are supported by bearings in the guide cylinder 304 or a support seat connected to the guide cylinder 304, allowing the lead screw 311 to rotate relative to the guide cylinder 304 without significant axial movement. The lead screw nut 313 is sleeved on the outside of the lead screw 311 and forms a ball screw pair with the lead screw 311.

[0040] When the lead screw 311 rotates, the circumferential motion of the lead screw nut 313 is restricted, and the rotational motion of the lead screw 311 is converted into the linear motion of the lead screw nut 313 along the axial direction of the lead screw 311. After the second servo motor 303 changes its rotation direction, the rotation direction of the lead screw 311 changes accordingly, and the lead screw nut 313 moves in the opposite direction, thereby forming the bidirectional driving force required for the extension and retraction of the output shaft 307.

[0041] In order to enable the lead screw nut 313 to drive the output shaft 307 to move axially, and at the same time to prevent the lead screw nut 313 from rotating when the output shaft 307 rotates, this embodiment provides an output shaft limiting ring 312 and an output shaft positioning ring 314 between the lead screw nut 313 and the output shaft 307.

[0042] The lead screw nut 313 and the output shaft limiting ring 312 form a fixed axial linkage relationship through a connecting seat or fastener. When the lead screw nut 313 moves up and down along the lead screw 311, the output shaft limiting ring 312 moves axially synchronously with the lead screw nut 313.

[0043] The output shaft limiting ring 312 is sleeved on the outside of the output shaft 307. Guide limiting keys are fixed on the left and right sides of the output shaft limiting ring 312 respectively. Guide grooves extending along the axial direction of the output shaft 307 are formed on both sides of the guide cylinder 304 corresponding to the guide limiting keys. The two guide limiting keys are inserted into the corresponding guide grooves and can slide linearly along the guide grooves.

[0044] The cooperation between the guide limit key and the guide groove serves two purposes. First, it restricts the output shaft limit ring 312 from rotating circumferentially relative to the guide cylinder 304, preventing the screw nut 313 connected to the output shaft limit ring 312 from rotating with the screw 311. This ensures that the ball screw pair can stably convert rotational motion into linear motion. On the other hand, the two relatively set guide positions can jointly constrain the movement direction of the output shaft limit ring 312, reducing its lateral deviation when subjected to the off-center load of the robotic arm.

[0045] The output shaft positioning ring 314 is located on the outside of the output shaft 307 and establishes an axial fixed relationship with the output shaft 307 through the shaft shoulder, locking nut, retaining ring or other axial positioning structure formed on the output shaft 307, that is, the output shaft positioning ring 314 and the output shaft 307 move synchronously in the axial direction.

[0046] A rotating support structure is provided between the output shaft positioning ring 314 and the output shaft limiting ring 312. In a preferred embodiment, the rotating support structure adopts a rolling bearing capable of withstanding axial loads. One side of the bearing forms an axial position with the output shaft limiting ring 312, and the other side forms an axial position with the output shaft positioning ring 314. Thus, when the output shaft limiting ring 312 moves up and down, the axial thrust or tension generated can be transmitted to the output shaft positioning ring 314 through the bearing, and then transmitted from the output shaft positioning ring 314 to the output shaft 307.

[0047] When the first servo motor 302 drives the output shaft 307 to rotate, the output shaft positioning ring 314 rotates synchronously with the output shaft 307. The bearing set between the output shaft positioning ring 314 and the output shaft limiting ring 312 allows the two to rotate relative to each other in the circumferential direction, so the output shaft limiting ring 312 remains in a non-rotating state. The lead screw nut 313 connected to the output shaft limiting ring 312 is also not affected by the rotational movement of the output shaft 307.

[0048] Therefore, the axial motion transmission path in this embodiment is: Second servo motor 303-transmission wheel 308-transmission belt 309-lead screw 311-lead screw nut 313-output shaft limit ring 312-rotation bearing structure-output shaft positioning ring 314-output shaft 307-connecting frame 1.

[0049] First servo motor 302 - driving gear 305 - driven gear 310 - output shaft rotating sleeve 315 - flat key 316 - output shaft 307 - connecting bracket 1.

[0050] Both power transmission paths ultimately act on the output shaft 307, but they are independent of each other within the transmission mechanism. The axial drive section is decoupled from the rotational motion of the output shaft 307 through a rotating support structure, and the rotary drive section is decoupled from the axial motion of the output shaft 307 through the sliding relationship between the flat key 316 and the axial elongated keyway. This allows the output shaft 307 to perform axial extension and retraction while maintaining a rotational connection, and at the same time, it can receive rotational power from the first servo motor 302 at any permissible axial position.

[0051] In a further preferred embodiment of the present invention, the installation mechanism 4 includes a rotating component 401, a first anti-deflection ring 402, a through groove 403, a second anti-deflection ring 404, an installer 405, a worm gear 406, a worm wheel 407, a maintenance rod 408, a guide rail 409, a limiting rod 410, a transmission plate 411, a support 412, a locking rod 413, and a connecting groove 414.

[0052] The mount 405 is set at the corresponding connection position, the rotating part 401 is rotatably connected to the mount 405, the first anti-deflection ring 402 is fixedly set on the outside of the rotating part 401, and the second anti-deflection ring 404 is set on one side of the first anti-deflection ring 402 and can move relative to the mount 405.

[0053] The first anti-deflection ring 402 and the second anti-deflection ring 404 are provided with toothed limiting structures that can cooperate with each other. When the second anti-deflection ring 404 moves to the first anti-deflection ring 402 and engages with it, it can limit the unexpected circumferential deflection of the rotating part 401 relative to the mount 405. When the second anti-deflection ring 404 moves away from the first anti-deflection ring 402, the corresponding circumferential lock is released.

[0054] The worm gear 406 is located inside the mounter 405 and meshes with the worm wheel 407. The inspection rod 408 is connected to the outer end of the worm gear 406. When the inspection rod 408 is rotated, it drives the worm gear 406 to rotate, and the worm gear 406 further drives the worm wheel 407 to rotate.

[0055] The transmission plate 411 is connected to the worm gear 407. The limiting rod 410 is set between the transmission plate 411 and the second anti-deflection ring 404. When the worm gear 407 drives the transmission plate 411 to move, the transmission plate 411 can transmit force to the second anti-deflection ring 404 through the limiting rod 410, so that the second anti-deflection ring 404 can move between the locked position and the released position.

[0056] The support 412 is located on the outside of the mount 405, the locking rod 413 is rotatably mounted on the support 412, and the connecting groove 414 is formed in the second anti-deflection ring 404. After the second anti-deflection ring 404 moves to the predetermined locking position, it can be connected to the connecting groove 414 through the locking rod 413 to maintain the position of the second anti-deflection ring 404, thereby preventing the anti-deflection structure from being automatically released due to long-term vibration.

[0057] In normal machining mode of the CNC machine tool, the connecting frame 1 is located in the preset initial position, and the two mounting parts 2 on both sides of the connecting frame 1 correspond to the tool on the spindle side and the tool to be exchanged on the tool magazine side, respectively. When the machine tool control system receives the tool change command, the control system first stops the spindle and moves the target tool in the tool magazine to the tool change position.

[0058] Subsequently, the second servo motor 303 starts working, driving the lead screw 311 to rotate via the transmission wheel 308 and the transmission belt 309. After the lead screw 311 rotates, the lead screw nut 313 moves along the axial direction of the lead screw 311, and the lead screw nut 313 drives the output shaft limiting ring 312 to move synchronously. The guide limiting keys on both sides of the output shaft limiting ring 312 slide along the guide grooves on both sides of the guide cylinder 304.

[0059] The axial force generated by the output shaft limiting ring 312 is transmitted to the output shaft positioning ring 314 through the rotating support structure. The output shaft positioning ring 314 then drives the output shaft 307 to move axially along the guide cylinder 304. The output shaft 307 further drives the connecting frame 1 and the mounting parts 2 on both sides of the connecting frame 1 to move synchronously, so that the tools held by the two mounting parts 2 move out along the axis of the spindle and the tool magazine sleeve, respectively, thereby completing the tool removal action.

[0060] During the aforementioned axial movement, the elongated keyway on the outer side of the output shaft 307 slides relative to the flat key 316. Neither the output shaft rotating sleeve 315 nor the driven gear 310 needs to move axially. Therefore, the telescopic action will not cause axial pulling on the gear transmission pair.

[0061] When the second servo motor 303 stops at the preset tool removal position, the control system confirms that the tool has disengaged from the spindle and tool magazine based on the position signal fed back by the encoder of the second servo motor 303. Then, the first servo motor 302 is started.

[0062] The first servo motor 302 drives the drive gear 305 to rotate, the drive gear 305 drives the driven gear 310 to rotate, and the driven gear 310 drives the output shaft rotating sleeve 315 to rotate synchronously. The output shaft rotating sleeve 315 transmits circumferential torque to the output shaft 307 through two flat keys 316, so that the output shaft 307, the connecting frame 1, the two mounting parts 2 and the corresponding tools rotate synchronously.

[0063] For tool changing structures using two-end robotic arms, the connecting frame 1 typically rotates approximately 180°, thereby transferring the tool originally located on the spindle side to the tool magazine side, and simultaneously transferring the target tool originally located on the tool magazine side to the spindle side. For other tool arrangement methods, the rotation angle of the first servo motor 302 can also be set according to the actual tool position angle.

[0064] Because a rotating support structure is provided between the output shaft positioning ring 314 and the output shaft limiting ring 312, when the output shaft 307 performs the above-mentioned rotational action, the output shaft 307 and the output shaft positioning ring 314 can rotate freely relative to the output shaft limiting ring 312. The output shaft limiting ring 312, the lead screw nut 313 and the lead screw 311 will not rotate with the output shaft 307, thereby avoiding the application of additional torque to the ball screw pair during the tool changing rotation.

[0065] After the first servo motor 302 reaches the preset rotation position, it stops. The control system then restarts the second servo motor 303 and makes it rotate in the opposite direction. The second servo motor 303 causes the lead screw 311 to rotate in the opposite direction through the transmission belt 309. The lead screw nut 313 moves in the opposite direction along the lead screw 311 and drives the output shaft 307 to move axially in the opposite direction in sequence through the output shaft limit ring 312, the rotating support structure, and the output shaft positioning ring 314.

[0066] When the output shaft 307 moves in the reverse direction, the connecting bracket 1 and the two mounting parts 2 carry the exchanged tools to the spindle and tool magazine respectively, so that the new tool is inserted into the spindle and the corresponding old tool is inserted into the tool magazine. The second servo motor 303 stops after reaching the preset tool loading position, thus completing one complete automatic tool change operation.

[0067] Therefore, the automatic tool changing action of the present invention can be summarized as follows: the mounting component 2 clamps the tool - the second servo motor 303 drives the output shaft 307 to axially pull out the tool - the first servo motor 302 drives the output shaft 307 and the connecting frame 1 to rotate and exchange - the second servo motor 303 drives the output shaft 307 in the opposite direction to axially load the tool - the mechanism resets.

[0068] Throughout the entire process described above, the first servo motor 302 only provides rotary power output, and the second servo motor 303 only provides axial power output. The two power mechanisms do not need to be switched through a mechanical clutch structure. Through the axial sliding and circumferential force transmission of the flat key 316 and the rotational decoupling structure between the output shaft limit ring 312 and the output shaft positioning ring 314, the two powers can act on the same output shaft 307 respectively, thereby realizing dual-servo automatic tool change.

[0069] In other embodiments, proximity switches, limit switches, or position sensors can be installed at both ends of the axial travel of the output shaft 307 to assist in detecting the tool withdrawal limit position and the tool loading limit position; alternatively, an origin detection sensor can be installed at the rotation position of the connecting frame 1 to determine the initial angle of the robotic arm when the equipment starts. The aforementioned detection components can be connected to the CNC machine tool control system to form auxiliary safety protection beyond servo encoder position feedback, and their installation does not alter the mechanical transmission principle described in this invention.

[0070] In this embodiment, the ball screw pair, gear transmission pair, and each rotating bearing can be lubricated according to the load and tool change frequency. The guide cylinder 304 can provide mounting support and motion constraints for the output shaft 307, the lead screw 311, and related axial moving parts. The specific dimensions of each component, gear transmission ratio, ball screw lead, servo motor power, and connecting frame 1 length can be selected according to the spindle size of the CNC machine tool, tool weight, tool magazine position, and tool change time requirements.

[0071] It should be understood that the disclosed apparatus can be implemented in other ways, given the several embodiments provided in this application. For example, the apparatus embodiments described above are merely illustrative; the division of units described above is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or communication connections shown or discussed may be through some interfaces; the indirect coupling or communication connections between devices or units may be telecommunications or other forms.

[0072] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit the scope of protection of the invention. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on these embodiments, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art can still combine, add, delete, or otherwise adjust the features of the various embodiments of the present invention according to the circumstances without conflict or creative effort, thereby obtaining different technical solutions that do not fundamentally depart from the concept of the present invention. These technical solutions also fall within the scope of protection of the present invention.

Claims

1. A dual-servo automatic tool changer for CNC machine tools, comprising a connecting frame (1), a mounting component (2), a transmission mechanism (3), and a mounting mechanism (4), characterized in that: The two mounting components (2) are respectively disposed on both sides of the connecting frame (1); The transmission mechanism (3) includes a first servo motor (302), a second servo motor (303), a guide cylinder (304), an output shaft (307), a transmission wheel (308), a transmission belt (309), a driven gear (310), a lead screw (311), an output shaft limiting ring (312), a lead screw nut (313), an output shaft positioning ring (314), an output shaft rotating sleeve (315), and a flat key (316). The output shaft (307) is slidably arranged along the axial direction of the guide cylinder (304), and the bottom end of the output shaft (307) is connected to the connecting frame (1). The first servo motor (302) is connected to the driven gear (310) through a gear transmission pair. The driven gear (310) is connected to the output shaft rotating sleeve (315), and the flat key (316) is fixed to the inner side of the output shaft rotating sleeve (315) and slides axially with the output shaft (307). The second servo motor (303) is connected to the lead screw (311) via the transmission wheel (308) and the transmission belt (309). The lead screw nut (313) is threadedly connected to the lead screw (311). The lead screw nut (313) drives the output shaft (307) to move axially via the output shaft positioning ring (314) and the output shaft limiting ring (312). The mounting mechanism (4) includes a rotating component (401), a first anti-deflection ring (402), a second anti-deflection ring (404), and a mount (405). The mount (405) is located at the lower connection position of the output shaft (307). The rotating component (401) is rotatably mounted on the mount (405). The first anti-deflection ring (402) is fixed to the outside of the rotating component (401). The second anti-deflection ring (404) is slidably mounted on the outside of the mount (405) and engages separably with the first anti-deflection ring (402). The installation mechanism (4) further includes a worm (406), a worm wheel (407), a maintenance rod (408), a guide rail (409), a limiting rod (410), and a transmission plate (411). The worm (406) meshes with the worm wheel (407), the maintenance rod (408) is connected to the worm (406), the transmission plate (411) is connected to the worm wheel (407), and the limiting rod (410) is connected between the transmission plate (411) and the second anti-deflection ring (404) to drive the second anti-deflection ring (404) to move. The mounting mechanism (4) further includes a support (412), a locking rod (413), and a connecting groove (414). The support (412) is slidably disposed on the outside of the mount (405). The locking rod (413) is rotatably disposed on the support (412). The connecting groove (414) is opened on the second anti-deflection ring (404). The locking rod (413) and the connecting groove (414) are detachably connected to lock the position of the second anti-deflection ring (404).

2. The dual-servo automatic tool changer for CNC machine tools according to claim 1, characterized in that: The transmission mechanism (3) further includes a gearbox (301) and a drive gear (305). The drive gear (305) is fixed to the output end of the first servo motor (302). The drive gear (305) meshes with the driven gear (310). The driven gear (310) is fixedly sleeved on the outside of the output shaft rotating sleeve (315).

3. The dual-servo automatic tool changer for CNC machine tools according to claim 2, characterized in that: The output shaft rotating sleeve (315) is rotatably disposed at the lower part of the guide cylinder (304). There are two flat keys (316), which are respectively fixed on opposite sides of the inner side of the output shaft rotating sleeve (315). The output shaft (307) has keyways on both sides that extend axially and slide in cooperation with the corresponding flat keys (316).

4. The dual-servo automatic tool changer for CNC machine tools according to claim 3, characterized in that: The two flat keys (316) guide the axial extension and retraction of the output shaft (307) by sliding with the keyway of the output shaft (307), and transmit circumferential force to the output shaft (307) when the output shaft rotating sleeve (315) rotates, so as to drive the output shaft (307) and the connecting frame (1) to rotate.

5. The dual-servo automatic tool changer for CNC machine tools according to claim 1, characterized in that: The two drive wheels (308) are respectively located at the output end of the second servo motor (303) and one end of the lead screw (311). The drive belt (309) is sleeved on the outside of the two drive wheels (308). The lead screw (311) is a ball screw. The lead screw (311) and the lead screw nut (313) constitute a ball screw pair.

6. The dual-servo automatic tool changer for CNC machine tools according to claim 5, characterized in that: The output shaft positioning ring (314) is sleeved on the outside of the output shaft (307) and connected to the lead screw nut (313). The output shaft limiting ring (312) is disposed on the outside of the output shaft (307). The output shaft positioning ring (314) and the output shaft limiting ring (312) form an axial limiting fit, so that when the lead screw nut (313) moves along the lead screw (311), it drives the output shaft (307) to extend and retract along the guide cylinder (304).

7. The dual-servo automatic tool changer for CNC machine tools according to claim 6, characterized in that: The output shaft limiting ring (312) is provided with guide limiting parts on both sides, and the guide cylinder (304) is provided with axial guide structures extending along the extension and retraction direction of the output shaft (307) on both sides. The two guide limiting parts are slidably engaged with the corresponding axial guide structures to limit the circumferential offset of the output shaft limiting ring (312) and guide its axial movement.

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