Machine tool spindle dynamic balance system

Abstract

The utility model discloses a dynamic balance system for a machine tool spindle. The dynamic balance system comprises a first connecting disc, a first force sensor, a dynamic balance weight mechanism, a second force sensor, a second connecting disc and a chuck which are coaxially connected in sequence, an execution element is installed at the front end of the chuck, the dynamic balance weight mechanism is sleeved with an optical grating, and a speed sensor is arranged in the detection range of the optical grating. The dynamic balance weight mechanism comprises a shell, and two plane slewing mechanisms and a circuit board unit are arranged in the shell; the plane rotating mechanism comprises a balancing weight, a rotating disc, a lead screw transmission mechanism, a mounting plate and a driving motor; the rotary disc is driven by the driving motor to rotate relative to the mounting plate; the balancing weight can be driven by the lead screw transmission mechanism to do linear motion along the main shaft. In the machining process, the dynamic balance parameters of the machine tool are automatically adjusted, the dynamic unbalance phenomenon of the rotary machine tool in the machining process is reduced, the machining precision is improved, and the device is suitable for machining of workpieces of different types.

Description

Technical Field

[0001] This utility model relates to the field of rotary machine tool technology, and in particular to a machine tool spindle dynamic balancing system. Background Technology

[0002] Rotary machine tools, such as CNC lathes and boring machines, use a clamping mechanism to rotate a workpiece or cutting tool on the machine spindle. This creates relative motion and cutting forces between the clamping end and the fixed end of the workpiece and tool, thus machining the workpiece. During actual machining, the center of mass of the clamped workpiece or tool may not coincide with the axis of rotation of the machine spindle. As the machine rotates, the mechanism generates inertial forces and inertial torques. The magnitude and direction of these forces change periodically with the machine's operation. When these forces are unbalanced, the entire machine vibrates, leading to decreased machining accuracy and quality, wear and fatigue of parts, and noise. If the vibration frequency approaches the natural frequency of the machine tool system, it may cause resonance and damage to the machine. To mitigate harmful mechanical vibrations, improve machining accuracy and quality, enhance machine performance, and extend service life, it is necessary to dynamically balance the inertial forces and inertial torques generated during the machining process.

[0003] Existing machine tool spindle balancing devices typically involve adding a fixed counterweight to the clamping end, making the center of mass of the clamping end close to the axis of rotation. However, this type of device has the following drawbacks:

[0004] 1) Due to the dynamic imbalance that occurs during machine tool processing, the use of fixed counterweights cannot automatically adjust the deviation of the center of mass from the machine tool spindle axis, which can easily lead to machine tool vibration.

[0005] 2) Before processing, a special counterweight needs to be made, and the manufacturing accuracy and installation position accuracy of the counterweight will affect the dynamic balancing effect.

[0006] 3) For different processing tasks, the fixed counterweight has limited adjustment space, requiring machine shutdown to replace the counterweight, which increases production costs. Utility Model Content

[0007] The main objective of this invention is to provide a machine tool spindle dynamic balancing system, which aims to solve at least one of the technical problems of existing machine tool spindle balancing devices, namely, the inability to automatically adjust the deviation of the center of mass from the axis during machining, reliance on high-precision counterweight manufacturing, and poor adaptability.

[0008] To achieve the above objectives, this utility model provides a machine tool spindle dynamic balancing system, comprising a first connecting plate, a first force sensor, a dynamic balancing counterweight mechanism, a second force sensor, a second connecting plate, and a chuck connected coaxially in sequence; an actuator is installed at the front end of the chuck; a grating is fitted on the dynamic balancing counterweight mechanism, and a speed sensor is provided within the detection range of the grating;

[0009] The dynamic balancing counterweight mechanism includes a housing, inside which are arranged two planar rotary mechanisms and a circuit board unit, with the two planar rotary mechanisms respectively arranged on both sides of the circuit board unit; a wireless signal transceiver device connected to the circuit board unit is provided on the outer surface of the housing.

[0010] The planar rotary mechanism includes a counterweight, a rotary disk, a lead screw transmission mechanism, a mounting plate, and a drive motor. The drive motor is located on one side of the mounting plate away from the circuit board unit, and the rotary disk, connected to the output shaft of the drive motor, is located on the other side. The rotary disk rotates relative to the mounting plate under the drive of the drive motor. The lead screw transmission mechanism is mounted on the main shaft of the rotary disk. The counterweight is connected to the lead screw transmission mechanism and can move linearly along the main shaft under the drive of the lead screw transmission mechanism. The lead screw transmission mechanism and the drive motor are electrically connected to the circuit board unit.

[0011] Preferably, the housing has a charging port, which is electrically connected to the circuit board unit via a wire to supply power to the circuit board unit.

[0012] Preferably, the planar rotary mechanism further includes a power supply collector ring and a signal collector ring, which are coaxially fixed to the inner surface of the housing; a first brush and a second brush are symmetrically arranged at both ends of the secondary shaft of the rotary disk; the power supply collector ring slides in contact with the first brush and is connected to the power supply terminal on the circuit board unit through a power line; the signal collector ring slides in contact with the second brush and is connected to the signal output terminal on the circuit board unit through a signal line.

[0013] Preferably, a positioning hole is provided at the center of both the mounting plate and the rotary table, and a retaining ring is sleeved on the output shaft of the drive motor after it passes through the positioning holes of the mounting plate and the rotary table in sequence.

[0014] Preferably, a key is fixedly installed in the positioning hole of the rotary table, and a keyway that mates with the key is provided on the circumferential surface of the output shaft of the drive motor.

[0015] Preferably, the lead screw transmission mechanism includes a pair of guide rods, a motor mounting bracket, and a lead screw stepper motor; the pair of guide rods are arranged parallel and symmetrically on both sides of the main shaft of the rotary table; the two sides of the motor mounting bracket are slidably mounted on the pair of guide rods, and the lead screw stepper motor is fixedly connected to one end of the motor mounting bracket near the center of the rotary table, and the counterweight is fixedly connected to the other end; the lead screw stepper motor is electrically connected to the first brush and the second brush respectively through wires.

[0016] Preferably, a sliding mounting hole is provided on each of the two sides of the motor mounting bracket; the sliding mounting hole is slidably connected to the guide rod on the corresponding side, so that the motor mounting bracket carries the counterweight and the lead screw stepper motor and moves radially along the guide rod.

[0017] Preferably, the rotary table includes a rotary table chassis, a nut mounting base assembly, and two guide rod mounting bases; the two guide rod mounting bases are symmetrically fixed at both ends of the main shaft of the rotary table chassis for mounting the pair of guide rods; the nut mounting base assembly is fixed on the main shaft of the rotary table chassis and is slidably connected to the lead screw of the lead screw stepper motor.

[0018] Preferably, the housing includes a cylindrical outer shell, a front cover plate and a rear cover plate that are fixedly connected to both ends of the cylindrical outer shell.

[0019] Preferably, the inner surface of the cylindrical shell is provided with a first annular mounting plate, a circuit board mounting bracket, and a second annular mounting plate in sequence along the axial direction. The first annular mounting plate is fixedly connected to the first planar rotation mechanism, the circuit board mounting bracket is fixedly connected to the circuit board unit, and the second annular mounting plate is fixedly connected to the second planar rotation mechanism.

[0020] The above-mentioned machine tool spindle dynamic balancing system has the following beneficial effects:

[0021] 1) The machine tool spindle dynamic balancing system adopts a dual-plane rotary mechanism. Compared with the traditional machine tool that uses a counterweight with a fixed center diameter to adjust the dynamic imbalance, the two correction planes can be independently controlled to synchronously compensate for the dynamic imbalance of the machine tool spindle, effectively suppressing machine tool vibration and extending the service life of the machine tool.

[0022] 2) Each planar rotary mechanism uses a screw drive to drive the counterweight to move radially, thereby changing the radial distance of the center of mass of the planar rotary mechanism. Simultaneously, a drive motor drives the rotary table to rotate circumferentially, changing the circumferential angle of the center of mass of the planar rotary mechanism. This dual-degree-of-freedom adjustment mechanism can precisely control the centrifugal force vector of the counterweight mechanism, thus achieving automatic adjustment of the machine tool spindle dynamic balance parameters during machining. This not only effectively reduces dynamic imbalance during rotary machine tool machining and improves machining accuracy, but also significantly shortens the dynamic balance adjustment time through electromechanical synchronous drive, effectively improving machine tool production efficiency.

[0023] 3) The machine tool spindle dynamic balancing system enables the machine tool spindle to quickly reach a balanced state by synchronously adjusting the radial distance and circumferential angle of the center of mass of the dual-plane rotary mechanism. This improves the flexibility of counterweight adjustment and makes the system widely applicable, suitable for machining different types of blanks. Attached Figure Description

[0024] To more clearly illustrate the technical solutions of the embodiments of this utility model, the drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this utility model and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0025] Figure 1 This is a schematic diagram of the installation of the machine tool spindle dynamic balancing system in a machine tool according to one embodiment of the present invention;

[0026] Figure 2 This is a schematic diagram of the principle structure of the machine tool spindle dynamic balancing system in one embodiment of the present invention;

[0027] Figure 3 This is an exploded view of the machine tool spindle dynamic balancing system in one embodiment of the present invention;

[0028] Figure 4 for Figure 3 Exploded view of the dynamic balancing counterweight mechanism of the spindle dynamic balancing system of a medium-sized machine tool;

[0029] Figure 5 for Figure 4 A schematic diagram of the cylindrical outer shell of the dynamic balancing counterweight mechanism;

[0030] Figure 6 This is a schematic diagram of the planar rotary mechanism in one embodiment of the present invention;

[0031] Figure 7 This is an exploded view of a planar rotary mechanism in one embodiment of the present invention.

[0032] Figure 8 This is a schematic diagram of the rotary table in one embodiment of the present invention;

[0033] Figure 9 This is a schematic diagram of the communication between the machine tool spindle dynamic balancing system and the host computer in one embodiment of the present invention;

[0034] Figure 10 This is a schematic diagram of the initial position of the planar rotary mechanism in one embodiment of the present invention;

[0035] Figure 11 This is a schematic diagram of the adjusted position of the planar rotary mechanism in one embodiment of the present invention.

[0036] The serial numbers in the diagram are explained in detail below:

[0037] 100. Machine tool spindle dynamic balancing system; 200. Machine tool;

[0038] 1. First connecting plate; 2. First force sensor; 3. Dynamic balancing counterweight mechanism; 4. Second force sensor; 5. Second connecting plate; 6. Chuck; 7. Grating; 8. Speed ​​sensor; 9. Actuating element;

[0039] 31. Housing; 311. Front cover; 312. Cylindrical outer shell; 313. Rear cover; 32a. First planar rotation mechanism; 32b. Second planar rotation mechanism; 33. Circuit board unit;

[0040] 311. Front cover plate; 312. Cylindrical outer shell; 313. Rear cover plate; 314. First annular mounting plate; 315. Circuit board mounting bracket; 316. Second annular mounting plate;

[0041] 321. Mounting plate; 322. Rotary table; 323. Counterweight; 324. Screw drive mechanism; 3241. Motor mounting bracket; 3242. Screw stepper motor; 3243. Guide rod; 325. Drive motor; 326. Power supply slip ring; 327. Signal slip ring; 328. Snap ring;

[0042] 3221. Rotary table chassis; 3222. Nut mounting bracket assembly; 3223. Guide rod mounting bracket; 3224. First brush; 3225. Second brush; 3226. Key; 3227. Keyway. Detailed Implementation

[0043] To better understand the above technical solutions, exemplary embodiments of this disclosure will be described in more detail below with reference to the accompanying drawings. While exemplary embodiments of this disclosure are shown in the drawings, it should be understood that this disclosure can be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of this disclosure to those skilled in the art.

[0044] It should be understood that the specific embodiments described herein are merely illustrative of the present invention and are not intended to limit the present invention.

[0045] It should be understood that in the embodiments of this utility model, the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicate the orientation or positional relationship based on the coordinate system shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0046] In this utility model, unless otherwise explicitly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0047] In this utility model, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is within the detection range of the second feature or diagonally above it, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0048] refer to Figure 1 This is a schematic diagram showing the installation position of the machine tool spindle dynamic balancing system 100 on the machine tool 200 in the first embodiment of this utility model. Figure 2 and Figure 3 The machine tool spindle dynamic balancing system 100 of the first embodiment of this utility model includes a first connecting plate 1, a first force sensor 2, a dynamic balancing counterweight mechanism 3, a second force sensor 4, a second connecting plate 5, and a chuck 6 connected coaxially in sequence; an actuator 9 is installed at the front end of the chuck 6; a grating 7 is sleeved on the dynamic balancing counterweight mechanism 3, and a speed sensor 8 is arranged within the detection range of the grating 7; wherein, the detection range refers to the spatial area in which the scale of the grating 7 can be recognized by the speed sensor 8.

[0049] Understandably, the first connecting plate 1 of the machine tool spindle dynamic balancing system 100 is connected to the machine tool spindle to realize the overall fixed connection between the machine tool spindle dynamic balancing system 100 and the machine tool 200. Except for the speed sensor 8, all other components of the machine tool spindle dynamic balancing system 100 rotate synchronously with the machine tool spindle.

[0050] The two connecting discs (i.e., the first connecting disc 1 and the second connecting disc 5) are the connecting parts between the dynamic balance counterweight mechanism 3, the two force sensors and the chuck 6, and play a connecting role between different components.

[0051] The two force sensors (i.e., the first force sensor 2 and the second force sensor 4) have integrated wireless signal transmitters. The force sensors are used to detect the equivalent force of the reference surface corresponding to the force sensor and transmit the equivalent force to the host computer through the wireless signal transmitter.

[0052] The dynamic balancing counterweight mechanism 3 is equipped with a wireless transceiver device. The dynamic balancing counterweight mechanism 3 is used to adjust the resultant force of the centrifugal force of two or more counterweights in a plane perpendicular to the main shaft.

[0053] The grating 7 is fixedly connected to other components (including but not limited to two connecting discs, two force sensors, chuck 6, etc.) to achieve a fixed connection with the machine tool spindle, and has the same real-time rotational speed and azimuth angle as the machine tool spindle. Optionally, the grating 7 is sleeved on the housing 31 of the dynamic balancing counterweight mechanism 3.

[0054] Speed ​​sensor 8 is positioned within the detection range of grating 7. By detecting the real-time rotational speed and azimuth angle of grating 7, the speed and azimuth angle of the machine tool spindle are monitored. Speed ​​sensor 8 can be a photoelectric speed sensor, which is connected to the host computer via wired or wireless means. A wireless or wired speed sensor is preferred. Preferably, speed sensor 8 is positioned directly above grating 7.

[0055] The actuator 9 is the main component that generates the cutting force and cutting speed of the machine tool 200. It can be a cutting tool or a workpiece and is relatively stationary with respect to the machine tool spindle during machining. For example, when the actuator 9 is a lathe tool, the machine tool 200 is a lathe; when the actuator 9 is a workpiece, the machine tool 200 is a boring machine.

[0056] The chuck 6 is a connector that connects the machine tool spindle and the actuator 9, keeping the actuator 9 stationary relative to the machine tool spindle. Optionally, a clamp is provided on the side of the chuck 6 away from the second connecting plate 5. This clamp can be a chuck type, spindle type, angle iron type, or collet type clamp structure.

[0057] Preferably, the first connecting plate 1 has bolt holes on both sides that match the machine tool 200 and the first force sensor 2, respectively, and the center of the first connecting plate 1 has a slot that matches the machine tool spindle. The first force sensor 2 has bolt holes on both sides that match the first connecting plate 1 and the dynamic balancing counterweight mechanism 3, respectively. The housing 31 of the dynamic balancing counterweight mechanism 3 has bolt holes on both sides that match the first force sensor 2 and the second force sensor 4, respectively, and the housing 31 of the dynamic balancing counterweight mechanism 3 is equipped with a wireless signal transceiver. The grating 7 is provided with a clamp for fixing the grating 7 to other rotating elements. Optionally, the grating 7 is sleeved on the side of the dynamic balancing counterweight mechanism 3 closest to the first force sensor 2. The second force sensor 4 has bolt holes on both sides that match the dynamic balancing counterweight mechanism 3 and the second connecting plate 5, respectively. The second connecting plate 5 has bolt holes on both sides that match the second force sensor 4 and the chuck 6, respectively. That is, in this embodiment, the machine tool spindle dynamic balancing system 100 can achieve fixed connection between the components through bolt connection holes, and the machine tool spindle dynamic balancing system 100 as a whole can be fixedly connected to the machine tool spindle through the slot.

[0058] In other embodiments, the speed sensor 8 can be an electromagnetic, Hall effect, ultrasonic, or gyroscope speed sensor, and the obtained parameter results are the same as those of the photoelectric speed sensor. In this case, the measured element will change from the grating 7 to the measured element based on the corresponding sensor principle.

[0059] refer to Figure 4 The dynamic balancing counterweight mechanism 3 includes a housing 31, within which two planar rotary mechanisms 32 and a circuit board unit 33 are disposed. The two planar rotary mechanisms 32 are respectively disposed on both sides of the circuit board unit 33. A wireless signal transceiver device connected to the circuit board unit 33 is disposed on the outer surface of the housing 31.

[0060] Understandably, the housing 31 of the dynamic balancing counterweight mechanism 3 contains a first planar rotary mechanism 32a, a circuit board unit 33, and a second planar rotary mechanism 32b, which are fixedly connected. The first planar rotary mechanism 32a and the second planar rotary mechanism 32b are arranged in a mirror-symmetrical configuration with respect to the central normal plane of the circuit board unit 33. The two planar rotary mechanisms 32 (i.e., the first planar rotary mechanism 32a and the second planar rotary mechanism 32b) are electrically connected to the circuit board unit 33 via wires. The planar rotary mechanisms 32 are the main execution units of the dynamic balancing counterweight mechanism 3, and each planar rotary mechanism 32 corresponds to a correction plane. The circuit board unit 33 includes a circuit board integrating control circuitry and a battery. The circuit board unit 33 is the electronic control device of the dynamic balancing counterweight mechanism 3, capable of storing electrical energy, processing instructions sent from the host computer, and transmitting signals.

[0061] As a preferred option, refer to Figure 4The housing 31 includes a cylindrical outer shell 312, a front cover plate 311 and a rear cover plate 313 respectively fixedly connected to both ends of the cylindrical outer shell 312.

[0062] More specifically, bolt connection holes are provided on both ends of the cylindrical housing 312. The front cover plate 311 is fixedly connected to the front end of the cylindrical housing 312 (i.e., the end near the first force sensor 2) through the bolt connection holes, and the rear cover plate 313 is fixedly connected to the rear end of the cylindrical housing 312 (i.e., the end near the second force sensor 4) through the bolt connection holes.

[0063] Further, refer to Figure 5 The inner surface of the cylindrical outer shell 312 is provided with a first annular mounting plate 314, a circuit board mounting bracket 315 and a second annular mounting plate 316 in sequence along the axial direction. The first annular mounting plate 314 is fixedly connected to the first planar rotation mechanism 32a, the circuit board mounting bracket 315 is fixedly connected to the circuit board unit 33, and the second annular mounting plate 316 is fixedly connected to the second planar rotation mechanism 32b.

[0064] More specifically, the side of the first annular mounting plate 314 facing the front cover plate 311 is connected to the first planar rotary mechanism 32a by fasteners (such as screws, locating pins, etc.), the circuit board mounting bracket 315 includes multiple connecting plates evenly distributed around the cylindrical housing 312, the circuit board unit 33 is fixedly connected to the multiple connecting plates, and the side of the second annular mounting plate 316 facing the rear cover plate 313 is connected to the second planar rotary mechanism 32b by fasteners.

[0065] refer to Figure 6 and Figure 7 The planar rotary mechanism includes a counterweight 323, a rotary disk 322, a lead screw transmission mechanism 324, a mounting plate 321, and a drive motor 325. The drive motor 325 is mounted on one side of the mounting plate 321 away from the circuit board unit 33, and the rotary disk 322, connected to the output shaft of the drive motor 325, is mounted on the other side of the mounting plate 321. The rotary disk 322 rotates relative to the mounting plate 321 under the drive of the drive motor 325. The lead screw transmission mechanism 324 is mounted on the main shaft of the rotary disk 322. The counterweight 323 is connected to the lead screw transmission mechanism 324, and the counterweight 323 can move linearly along the main shaft under the drive of the lead screw transmission mechanism 324. The lead screw transmission mechanism 324 and the drive motor 325 are electrically connected to the circuit board unit 33.

[0066] Understandably, the planar rotary mechanism includes, but is not limited to, a counterweight 323, a rotary table 322, a lead screw transmission mechanism 324, a mounting plate 321, and a drive motor 325. The mounting plate 321 has circumferential mounting holes, allowing it to be fixedly connected to the housing 31.

[0067] The drive motor 325 mainly consists of a motor body and an output shaft. The motor body is preferably a worm gear stepper motor 27. The motor body of the drive motor 325 is fixedly connected to the side of the mounting plate 321 near the circuit board unit 33. The output shaft of the drive motor 325 passes through the positioning hole in the center of the mounting plate 321 and is fixedly connected to the rotary disk 322 so that the rotary disk 322 obtains torque and rotates relative to the mounting plate 321, thereby changing the circumferential angle of the center of mass of the planar rotary mechanism.

[0068] The screw drive mechanism 324 can adopt a combination structure of ball screw and linear guide rail, or a combination structure of parallel guide rod and screw stepper motor 3242. When the screw drive mechanism 324 adopts the combination structure of ball screw and linear guide rail, it includes a mounting base, a linear guide rail fixedly connected to the mounting base, a movable sleeve fixedly connected to one side of the mounting base, a servo motor fixedly connected to the other side of the mounting base, a ball screw fixedly connected to the output end of the motor, the end of the ball screw away from the servo motor being movably connected to the movable sleeve, and a slider threaded to the outer side of the ball screw. This slider can move linearly along the axial direction of the guide rail under the drive of the servo motor. For the screw drive mechanism 324 with the above structure, its mounting base is fixedly connected to the main shaft of the rotary table 322, and the counterweight 323 is fixedly connected to the slider. When the servo motor is started, the output end of the servo motor drives the ball screw to rotate, thereby driving the slider and the counterweight 323 to move radially along the linear guide rail, thereby changing the radial distance of the center of mass of the planar rotary mechanism.

[0069] In summary, the machine tool spindle dynamic balancing system 100 of this embodiment has the following beneficial effects:

[0070] 1) The machine tool spindle dynamic balancing system 100 in this embodiment adopts a dual-plane rotary mechanism. Compared with the fixed counterweight used in traditional machine tools, it can synchronously compensate for the dynamic imbalance of the machine tool spindle by independently controlling two correction planes, effectively suppressing machine tool vibration and extending the service life of the machine tool.

[0071] 2) Each planar rotary mechanism uses a lead screw drive mechanism 324 to drive the counterweight 323 to move radially to change the radial distance of the center of mass of the planar rotary mechanism. At the same time, the drive motor 325 drives the rotary table 322 to rotate circumferentially to change the circumferential angle of the center of mass of the planar rotary mechanism. This dual-degree-of-freedom adjustment method can accurately change the centrifugal force vector of the dynamic balance counterweight mechanism, thereby realizing the automatic adjustment of the dynamic balance parameters of the machine tool spindle during the processing. This not only effectively reduces the dynamic imbalance phenomenon in the processing of rotary machine tools and improves the machining accuracy of the machine tool, but also significantly shortens the dynamic balance adjustment time through electromechanical synchronous drive, effectively improving the machine tool production efficiency.

[0072] 3) The machine tool spindle dynamic balancing system 100 in this embodiment enables the machine tool spindle to quickly reach a balanced state by simultaneously adjusting the radial distance and circumferential angle of the center of mass of the dual-plane rotary mechanism. This improves the flexibility of counterweight adjustment and makes the system widely applicable, suitable for processing different types of workpiece blanks.

[0073] In a preferred embodiment, the housing 31 is provided with a charging port, which is electrically connected to the circuit board unit 33 via a wire to supply power to the circuit board unit 33.

[0074] In this embodiment, the charging port on the housing 31 can be located near the circuit board unit 33 to shorten the circuit wiring.

[0075] refer to Figure 6 and Figure 7 In a preferred embodiment, the planar rotary mechanism 32 further includes a power supply collector ring 326 and a signal collector ring 327, which are coaxially fixed to the inner surface of the housing 31. A first brush 3224 and a second brush 3225 are symmetrically arranged at both ends of the secondary shaft of the rotary disk 322. The power supply collector ring 326 is in sliding contact with the first brush 3224 and is connected to the power supply terminal on the circuit board unit 33 via a power line. The signal collector ring 327 is in sliding contact with the second brush 3225 and is connected to the signal output terminal on the circuit board unit 33 via a signal line.

[0076] Understandably, since the lead screw drive mechanism 324 is located on the side of the rotary table 322 away from the circuit board unit 33, and the rotary table 322 needs to rotate relative to the mounting plate 321, a fixed wiring method would easily lead to the risk of wire tangling. Therefore, in this embodiment, the planar rotary mechanism 32 adopts a combination wiring method of slip ring and brush, which effectively avoids the problem of wire tangling or breakage caused by the relative rotational movement between the lead screw drive mechanism 324 and the rotary table 322, and enhances the reliability of electrical connection.

[0077] In this embodiment, both the power supply collector ring 326 and the signal collector ring 327 of the planar rotary mechanism 32 adopt a ring structure design. The two collector rings are based on a ring-shaped insulating substrate. The inner surface of the ring-shaped insulating substrate is provided with an intermediate insulating plate, and the first conductor and the second conductor are symmetrically arranged on both sides. The conductor material is copper or aluminum and other metals. The first brush 3224 and the second brush 3225 on the rotary disk 322 both adopt a sandwich brush head structure. The brush head structure consists of a first conductive layer, an intermediate insulating layer and a second conductive layer from top to bottom. The brush head has a built-in spring to keep it in contact with the ring structure. Each brush has a mounting post at the bottom, which is fixedly connected to the rotary disk 322. The outer surfaces of the power supply slip ring 326 and the signal slip ring 327 are adhered to the housing 31 with insulating adhesive. The first and second conductors of the power supply slip ring 326 are respectively connected to the positive and negative terminals of the power supply of the circuit board unit 33. By cooperating with the corresponding conductive layer of the first brush 3224, a power supply circuit is formed to supply power to the lead screw drive mechanism 324. The first and second conductors of the signal slip ring 327 are respectively connected to the two ends of the motor control signal of the circuit board unit 33. Through the corresponding conductive layer of the second brush 3225, a signal transmission path is formed to transmit the control signal to the lead screw drive mechanism 324. For example, when the motor control signal is a single-ended pulse signal, the two ends are the signal end and the reference end, respectively.

[0078] To optimize wiring, mounting plate 321 is provided with at least one wire through hole to facilitate wiring between slip ring and circuit board unit 33, ensuring the neatness and reliability of the overall structure.

[0079] refer to Figure 6 and Figure 7 In a preferred embodiment, positioning holes are provided at the center of both the mounting plate 321 and the rotary table 322. After the output shaft of the drive motor 325 passes through the positioning holes of the mounting plate 321 and the rotary table 322 in sequence, a retaining ring 328 is fitted on it.

[0080] In this embodiment, the front end of the output shaft of the drive motor 325 is provided with a slot corresponding to the snap ring 328. By cooperating with the snap ring 328 and the slot, the rotary table 322 can be prevented from coming off the output shaft of the drive motor 325, thereby improving the connection stability.

[0081] refer to Figure 8 In a preferred embodiment, a key 3226 is fixedly installed in the positioning hole of the rotary table 322, and a keyway 3227 that mates with the key 3226 is provided on the circumferential surface of the output shaft of the drive motor 325.

[0082] In this embodiment, keyways 3227 are provided on the inner wall of the positioning hole of the rotary disk 322 and the outer side of the output shaft of the drive motor 325. A key 3226 is fixedly connected in the keyway 3227. The rotary disk 322 can obtain torque and rotate relative to the mounting plate 321 by the cooperation of the key 3226 and the keyway 3227.

[0083] refer to Figure 6 and Figure 7 In a preferred embodiment, the lead screw transmission mechanism 324 includes a pair of guide rods 3243, a motor mounting bracket 3241, and a lead screw stepper motor 3242; the pair of guide rods 3243 are symmetrically arranged on both sides of the main shaft of the rotary table 322; the two sides of the motor mounting bracket 3241 are slidably mounted on the pair of guide rods 3243, and the lead screw stepper motor 3242 is fixedly connected to one end of the motor mounting bracket 3241 near the center of the rotary table 322, and the counterweight block 323 is fixedly connected to the other end; the lead screw stepper motor 3242 is electrically connected to the first brush 3224 and the second brush 3225 respectively through wires.

[0084] In this embodiment, the lead screw transmission mechanism 324 adopts a combination structure of parallel guide rods and a lead screw stepper motor 3242, mainly composed of a pair of guide rods 3243, a motor mounting bracket 3241, and the lead screw stepper motor 3242. The motor mounting bracket 3241 has an axial mounting hole in the middle of its end near the positioning hole of the rotary table 322 (i.e., the front end of the motor mounting bracket 3241), which is used to clamp the motor housing of the lead screw stepper motor 3242 through an interference fit. The rear end of the motor mounting bracket 3241 is fixedly connected to the counterweight 323. The two sides of the motor mounting bracket 3241 can be slidably connected to the corresponding guide rods 3243 via linear bearings or sliding sleeves. The axes of the guide rods 3243 and the lead screw stepper motor 3242 are parallel to each other.

[0085] The lead screw stepper motor 3242 mainly consists of a motor body and a lead screw. One end of the motor body is fixed in the axial mounting hole on the motor mounting bracket 3241, and the other end is connected to the lead screw through an output shaft. The length of the lead screw is approximately 0.9 to 1.1 times the radius of the rotary table 322. Figure 10As shown. The first brush 3224 is connected to the lead screw stepper motor 3242 via a power cable to provide power, and the second brush 3225 is connected to the lead screw stepper motor 3242 via a signal cable to transmit signals. Optionally, the lead screw stepper motor 3242 can be a lead screw motor with or without a ball nut. When the lead screw stepper motor 3242 is a lead screw motor with a ball nut, the rotary table 322 is provided with a nut mounting bracket that is compatible with the ball nut; when the lead screw stepper motor 3242 is a lead screw motor without a ball nut, the rotary table 322 is provided with a nut mounting seat assembly 3222, which consists of a ball nut and a base.

[0086] When the lead screw stepper motor 3242 is powered on and started, it drives the lead screw to rotate. The lead screw and the ball nut sleeved on the outside of the lead screw form a linear motion pair. Since the ball nut is fixed on the rotary table 322, the lead screw will generate a reaction force at the connection with the rotary table 322 when it rotates. This force pushes the motor mounting bracket 3241, the counterweight 323 and the lead screw stepper motor 3242 to move radially along the guide rod 3243, thereby changing the radial distance of the center of mass of the planar rotary mechanism 32.

[0087] Preferably, the motor mounting bracket 3241 has a sliding mounting hole on each side; the sliding mounting hole is slidably connected to the guide rod 3243 on the corresponding side, so that the motor mounting bracket 3241 carries the counterweight 323 and the lead screw stepper motor 3242 and moves radially along the guide rod 3243.

[0088] In summary, in this embodiment, the lead screw transmission mechanism 324, the guide rod 3243 and the lead screw stepper motor 3242 are arranged separately and connected to the counterweight block 323 through the motor mounting frame. Compared with the combined structure of ball screw and linear slide rail, the structure is more compact.

[0089] refer to Figure 6 and Figure 8 In a preferred embodiment, the rotary table 322 includes a rotary table base 3221, a nut mounting seat assembly 3222, and two guide rod mounting seats 3223; the two guide rod mounting seats 3223 are symmetrically fixed at both ends of the main shaft of the rotary table base 3221 for mounting the pair of guide rods 3243; the nut mounting seat assembly 3222 is fixed on the main shaft of the rotary table base 3221 and is slidably connected to the lead screw of the lead screw stepper motor 3242.

[0090] In this embodiment, the rotary table 322 adopts a symmetrical structural design, with its rotary table base 3221 serving as the main supporting element. The rotary table base 3221 is equipped with a main shaft and a secondary shaft that are perpendicular to each other, and the intersection of the two shafts is located at the center of the rotary table base 3221. Two guide rod mounting seats 3223 are symmetrically arranged at both ends of the main shaft of the rotary table base 3221, and a first brush 3224 and a second brush 3225 are symmetrically arranged at both ends of the secondary shaft. The nut mounting seat assembly 3222 is fixed to the main shaft of the rotary table base 3221 near the positioning hole, forming a threaded engagement with the lead screw of the lead screw stepper motor 3242, thereby converting the rotational motion of the lead screw into linear motion.

[0091] Two guide rod mounting seats 3223 are used to install and fix a pair of guide rods. More specifically, the guide rod mounting seats 3223 are provided with two symmetrically distributed guide rod connecting holes. The two ends of each guide rod 3243 are respectively fixedly connected to the guide rod connecting holes on the same side of the two guide rod mounting seats 3223. The center of the guide rod mounting seat 3223 is also provided with a limiting opening adapted to the counterweight 323 to constrain the maximum displacement of the counterweight 323.

[0092] In summary, the rotary table 322 in this embodiment adopts a symmetrical structural design, which can improve the stability of mechanical transmission and make the whole structure more compact and reasonable.

[0093] refer to Figure 10 When the machine tool spindle dynamic balancing system 100 is connected to the host computer 300, the dynamic balancing adjustment process of the machine tool spindle dynamic balancing system 100 is as follows:

[0094] Step S10: Start the machine tool and drive the machine tool spindle dynamic balancing system to rotate. The two planar rotary mechanisms in the machine tool spindle dynamic balancing system self-lock and remain in the initial position.

[0095] Before starting the machine tool, the actuator is installed on the chuck of the machine tool spindle dynamic balancing system. The actuator is the workpiece blank or tool to be processed.

[0096] During the balancing phase, the machine tool with the actuators installed is started, causing the machine tool spindle dynamic balancing system to rotate. The two planar rotary mechanisms in the machine tool spindle dynamic balancing system achieve self-locking under centrifugal force and remain stationary. Figure 10 The initial position is shown.

[0097] The working principle of the self-locking mechanism is as follows:

[0098] For the lead screw drive mechanism, which includes a lead screw stepper motor, the lead screw stepper motor adopts a short lead screw. When the helix angle of the lead screw is less than the equivalent friction angle of the threaded pair, the threaded pair formed by the lead screw and the nut mounting seat assembly on the rotary table satisfies the self-locking condition, thereby realizing the self-locking of the lead screw drive mechanism.

[0099] For the drive motor, a worm gear stepper motor is adopted. Under static conditions, when the lead angle of the worm is less than the equivalent friction angle between the gears (i.e., the equivalent friction angle when the worm gear meshes), the worm output shaft cannot drive the worm input shaft in reverse, thereby realizing the mechanical self-locking characteristic of the worm gear transmission. This characteristic, together with the electromagnetic self-locking when the stepper motor is energized, constitutes a double protection.

[0100] Step S20: The unbalanced centrifugal force signal is collected by the first force sensor and the second force sensor, and the rotational speed and phase angle signal is collected by the speed sensor.

[0101] Because the actuator has a dynamic unbalanced mass, the resulting unbalanced centrifugal force can be detected by the force sensor in the first base plane corresponding to the first force sensor and the second base plane corresponding to the second force sensor, according to the principle of parallel force equivalence. The force sensor then sends the results to the host computer, which receives and displays the unbalanced centrifugal force in the two base planes. This unbalanced centrifugal force is a vector force with magnitude and direction.

[0102] Secondly, the speed sensor detects the rotational speed (angular velocity ω) and phase angle of the machine tool spindle in real time and sends them to the host computer, which receives and displays them.

[0103] Step S30: Based on the spatial dynamic balance mechanical model, and according to the unbalanced centrifugal force signal, the rotational speed and phase angle signal, obtain the adjustment parameters of the center of mass of each planar rotary mechanism; the adjustment parameters include the target displacement of the counterweight and the target angle of the rotary disk.

[0104] In this embodiment, the unbalanced centrifugal force signal and the speed and phase angle signal are both analog signals. After receiving the unbalanced centrifugal force signal and the speed and phase angle signal, the host computer performs analog-to-digital conversion to obtain the corresponding digital quantities, namely the unbalanced centrifugal force of the two base planes and the speed of the machine tool spindle. Combined with the spatial dynamic balance mechanical model, the radial distance and circumferential angle that the center of mass of the two planar rotary mechanisms should be adjusted are calculated. At this time, the target displacement of the counterweight in the planar rotary mechanism can be determined based on the calculated radial distance that the center of mass should be adjusted, and the target angle of the rotary disk in the planar rotary mechanism can be determined based on the calculated circumferential angle that the center of mass should be adjusted. Here, the spatial dynamic balance mechanical model refers to the model where the mass-radius product in the base plane is zero ∑m. i ′r i ′=∑m i "r i "=0 or the resultant centrifugal force ∑F i ′=∑F i "=0 means zero".

[0105] Step S40: For each of the planar rotary mechanisms, the mass block is driven to move to the target displacement through the lead screw transmission mechanism, and the rotary table is driven to rotate to the target angle through the drive motor. After the adjustment is completed, the planar rotary mechanism is self-locked.

[0106] In this embodiment, the lead screw drive mechanism uses a lead screw stepper motor to drive the mass block to move radially along the guide rail, and the drive motor uses a worm gear stepper motor to drive the rotary table to rotate circumferentially. At this time, the host computer obtains the adjustment parameters of the center of mass of the planar rotary mechanism, generates a balance adjustment command, and sends it to the circuit board unit. The circuit board unit receives and parses the balance adjustment command.

[0107] The circuit board unit calculates the number of drive steps (i.e., the number of pulses received by the stepper motor) corresponding to the lead screw stepper motor and the worm gear stepper motor based on the adjustment parameters obtained from the analysis. At the same time, it generates a first pulse control signal to control the lead screw stepper motor and a second pulse control signal to control the worm gear stepper motor. The first pulse control signal is transmitted to the lead screw stepper motor through the signal collector ring, the second brush, and the signal line, driving the output shaft of the lead screw stepper motor to rotate by a corresponding angle. This pushes the motor mounting bracket and counterweight connected to the lead screw stepper motor to move radially. After moving to the target displacement, they stop and self-lock, thereby changing the radial distance of the center of mass of the planar rotary mechanism. Simultaneously, the second pulse control signal is transmitted to the worm gear stepper motor through the signal line, driving the worm gear stepper motor to rotate precisely by a corresponding angle. This drives the rotary disk connected to the worm gear stepper motor to rotate circumferentially. After rotating to the target angle, it stops and self-locks, thereby changing the circumferential angle of the center of mass of the planar rotary mechanism. Ultimately, by changing the radial distance and circumferential angle of the center of mass of the planar rotary mechanism, the centrifugal force of the planar rotary mechanism corresponding to the correction plane is changed, thus achieving dynamic balance of the entire machine tool spindle dynamic balancing system. At this point, the adjusted planar rotary mechanism has the following position of its counterweight: Figure 11 As shown.

[0108] It should be noted that, in addition to the stepper motor control method described in the above embodiments, those skilled in the art can use other methods in the prior art to control the motor based on the structure in this application, as long as the same or equivalent technical effects as this application can be achieved. The specific stepper motor control method will not be described in detail here.

[0109] In step S50, the adjusted residual centrifugal force signal is collected by the first force sensor and the second force sensor, and the machine tool spindle dynamic balancing system is in a dynamic balance state after the residual centrifugal force signal meets the preset dynamic balance standard.

[0110] In this embodiment, the dynamic balance standard refers to the residual centrifugal force signal being less than or equal to a preset dynamic balance threshold, which is preferably 10N.

[0111] That is, the centrifugal force after dynamic imbalance adjustment is detected by the first force sensor and the second force sensor, and sent to the host computer as the residual centrifugal force. The host computer receives and judges whether the two centrifugal forces after dynamic imbalance adjustment are both less than or equal to 10N. If both are less than or equal to 10N, the machine tool spindle dynamic balancing system is confirmed to be in a dynamic balance state. If the centrifugal force after dynamic imbalance adjustment is greater than 10N, it is determined that it does not meet the dynamic balance standard, and a new balance adjustment command is generated and sent to the circuit board unit until the machine tool spindle dynamic balancing system is in a dynamic balance state.

[0112] The above are merely preferred embodiments of this utility model and do not limit the patent scope of this utility model. Any equivalent structural or procedural transformations made based on the description and drawings of this utility model, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of this utility model.

Claims

1. A machine tool spindle dynamic balancing system, characterized in that, It includes a first connecting plate, a first force sensor, a dynamic balancing counterweight mechanism, a second force sensor, a second connecting plate, and a chuck, all connected coaxially in sequence; an actuator is installed at the front end of the chuck; a grating is fitted on the dynamic balancing counterweight mechanism, and a speed sensor is set within the detection range of the grating; The dynamic balancing counterweight mechanism includes a housing, inside which are arranged two planar rotary mechanisms and a circuit board unit, with the two planar rotary mechanisms respectively arranged on both sides of the circuit board unit; a wireless signal transceiver device connected to the circuit board unit is provided on the outer surface of the housing. The planar rotary mechanism includes a counterweight, a rotary disk, a lead screw transmission mechanism, a mounting plate, and a drive motor. The drive motor is located on one side of the mounting plate away from the circuit board unit, and the rotary disk, connected to the output shaft of the drive motor, is located on the other side. The rotary disk rotates relative to the mounting plate under the drive of the drive motor. The lead screw transmission mechanism is mounted on the main shaft of the rotary disk. The counterweight is connected to the lead screw transmission mechanism and can move linearly along the main shaft under the drive of the lead screw transmission mechanism. The lead screw transmission mechanism and the drive motor are electrically connected to the circuit board unit.

2. The machine tool spindle dynamic balancing system as described in claim 1, characterized in that, The housing has a charging port, which is electrically connected to the circuit board unit via a wire to supply power to the circuit board unit.

3. The machine tool spindle dynamic balancing system as described in claim 1, characterized in that, The planar rotary mechanism further includes a power supply collector ring and a signal collector ring, which are coaxially fixed to the inner surface of the housing. A first brush and a second brush are symmetrically arranged at both ends of the secondary shaft of the rotary table. The power supply collector ring slides in contact with the first brush and is connected to the power supply terminal on the circuit board unit through a power line. The signal collector ring slides in contact with the second brush and is connected to the signal output terminal on the circuit board unit through a signal line.

4. The machine tool spindle dynamic balancing system as described in claim 1, characterized in that, The mounting plate and the rotary table are both provided with positioning holes at their center positions. The output shaft of the drive motor passes through the positioning holes of the mounting plate and the rotary table in sequence and is fitted with a retaining ring.

5. The machine tool spindle dynamic balancing system as described in claim 4, characterized in that, A key is fixedly installed in the positioning hole of the rotary table, and a keyway that mates with the key is provided on the circumferential surface of the output shaft of the drive motor.

6. The machine tool spindle dynamic balancing system as described in claim 3, characterized in that, The lead screw transmission mechanism includes a pair of guide rods, a motor mounting bracket, and a lead screw stepper motor; the pair of guide rods are arranged parallel and symmetrically on both sides of the main shaft of the rotary table; the two sides of the motor mounting bracket are slidably mounted on the pair of guide rods, and the lead screw stepper motor is fixedly connected to one end of the motor mounting bracket near the center of the rotary table, and the counterweight is fixedly connected to the other end; the lead screw stepper motor is electrically connected to the first brush and the second brush respectively through wires.

7. The machine tool spindle dynamic balancing system as described in claim 6, characterized in that, The motor mounting bracket has a sliding mounting hole on each side; the sliding mounting hole is slidably connected to the guide rod on the corresponding side, so that the motor mounting bracket carries the counterweight and the lead screw stepper motor and moves radially along the guide rod.

8. The machine tool spindle dynamic balancing system as described in claim 7, characterized in that, The rotary table includes a rotary table chassis, a nut mounting base assembly, and two guide rod mounting bases; the two guide rod mounting bases are symmetrically fixed at both ends of the main shaft of the rotary table chassis for mounting the pair of guide rods; the nut mounting base assembly is fixed on the main shaft of the rotary table chassis and is slidably connected to the lead screw of the lead screw stepper motor.

9. The machine tool spindle dynamic balancing system as described in claim 1, characterized in that, The housing includes a cylindrical outer shell, a front cover plate and a rear cover plate that are fixedly connected to both ends of the cylindrical outer shell.

10. The machine tool spindle dynamic balancing system as described in claim 9, characterized in that, The inner surface of the cylindrical shell is provided with a first annular mounting plate, a circuit board mounting bracket, and a second annular mounting plate in sequence along the axial direction. The first annular mounting plate is fixedly connected to a first planar rotation mechanism, the circuit board mounting bracket is fixedly connected to the circuit board unit, and the second annular mounting plate is fixedly connected to a second planar rotation mechanism.

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