Thread processing device, method and system

Abstract

The embodiments of the present disclosure relate to a thread processing device (300), a method and a system. The thread processing device (300) comprises a spindle motor (310) suitable for driving a thread cutting tool (200) coupled to an output shaft of the spindle motor (310) to rotate at a rotational speed, and a feed device (320) movably coupled to the spindle motor (310) and configured to drive the spindle motor (310) to move the thread cutting tool (200) along an axial direction (X) of the spindle motor (310) at a moving speed, the moving speed being proportional to the rotational speed during thread processing. The solution of the embodiments of the present disclosure significantly improves the efficiency, stability and accuracy of thread processing.

Description

[Technical field]

[0001] TECHNICAL FIELD Embodiments of the present disclosure relate generally to the field of thread machining, and more specifically to thread machining devices, methods and systems. [Background technology]

[0002] Screws are widely used in mechanical connections. The machining accuracy of the screw greatly affects the quality of the screw. There are many screw machining methods, such as thread rolling, turning, milling, tapping, thread cutting, grinding, and whirling cutting, which are based on plastic deformation, usually processed by lathes and milling machines. Among them, tapping is the main method of machining female threads. Tapping is to screw a tap into a pre-drilled pilot hole on a workpiece with a certain torque to machine a female thread on the inner cylindrical surface of the workpiece.

[0003] Traditional methods of thread processing include manual tapping, thread processing on a CNC (computer numerical control) lathe, etc. Manual tapping has the disadvantages of low efficiency and low processing accuracy, while processing threads on a CNC lathe has the disadvantages of high cost and large floor space.

[0004] Therefore, there is a need for an improved thread processing device and method. Summary of the Invention [Problem to be solved by the invention]

[0005] In view of the above problems, various exemplary embodiments of the present disclosure provide thread machining apparatus, methods and systems to overcome at least one of the above deficiencies or potential other deficiencies. [Means for solving the problem]

[0006] In a first aspect of the present disclosure, an exemplary embodiment of the present disclosure provides a thread processing apparatus, comprising: a spindle motor adapted to drive a thread cutting tool coupled to an output shaft of the spindle motor to rotate at a rotational speed, and a feeder movably coupled to the spindle motor and configured to drive the spindle motor to move the thread cutting tool along an axial direction (X) of the spindle motor at a moving speed, wherein during thread processing, the moving speed is proportional to the rotational speed.

[0007] This arrangement allows synchronization between feeding and tapping, improving the machining accuracy of the screws.

[0008] In some embodiments, the ratio of the moving speed to the rotation speed is equal to the pitch of the thread cutting tool, so that the ratio of the moving speed to the rotation speed can be adjusted according to the pitch to be cut, which can significantly improve the cutting accuracy of the thread.

[0009] In some embodiments, the feed device includes a servo motor and a transmission device coupled to an output shaft of the servo motor and configured to convert rotation of the output shaft of the servo motor into linear movement along an axial direction of the spindle motor to drive the spindle motor.

[0010] With this arrangement, the transmission device converts the rotation of the output shaft of the servo motor into linear movement along the axial direction of the spindle motor to drive the spindle motor, thereby enabling the spindle motor to achieve accurate linear movement.

[0011] In some embodiments, the transmission device includes a gear box connected to an output shaft of the servo motor, a ball screw movably connected to a gear in the gear box, a ball nut disposed on the ball screw and configured to move along the axial direction of the ball screw as the ball screw rotates, and a slide member connected between the ball nut and the spindle motor and sliding as the ball nut moves, thereby driving the spindle motor to move along the axial direction of the spindle motor.

[0012] With this arrangement, the rotation of the output shaft of the servo motor can be easily and reliably converted into linear movement along the axial direction of the spindle motor.

[0013] In some embodiments, the transmission device includes a first belt pulley fixedly connected to an output shaft of the servo motor, a gearbox, a second belt pulley fixedly connected to a shaft of the gearbox, a belt that drives the second belt pulley together with the first belt pulley by connecting the first belt pulley to the second belt pulley, and a slide member that is connected between the gearbox and the spindle motor and slides with rotation of the output shaft of the servo motor, thereby driving the spindle motor to move along the axial direction of the spindle motor.

[0014] With this arrangement, the rotation of the output shaft of the servo motor can be easily and reliably converted into linear movement along the axial direction of the spindle motor.

[0015] In some embodiments, the transmission device includes a first belt pulley fixedly connected to an output shaft of the servo motor, a belt, a second belt pulley connected to the first belt pulley via the belt, a ball screw connected to a shaft of the second belt pulley and rotating with the rotation of the second belt pulley, a ball nut disposed on the ball screw and configured to move along the axial direction of the ball screw with the rotation of the ball screw, and a slide member connected between the ball nut and the spindle motor and sliding with the movement of the ball nut, thereby driving the spindle motor to move along the axial direction of the spindle motor.

[0016] In some embodiments, the speed of movement is proportional to the product of the circumference of the first belt pulley and the rotational speed of the servo motor.

[0017] With this arrangement, the moving speed of the spindle motor can be controlled simply and accurately.

[0018] In some embodiments, the transmission device further includes a slide track extending along the axial direction of the spindle motor, and the slide member slides along the slide track.

[0019] This arrangement allows the spindle motor to be driven smoothly along the slide track.

[0020] In some embodiments, the apparatus further comprises a positioning mechanism fixedly coupled to the feed device and adapted to position the feed device to align the threading tool with a threaded hole to be machined in the workpiece.

[0021] With this arrangement, the positioning mechanism can move freely within a predetermined space, so that the output shaft of the spindle motor can be easily moved to the part to be machined.

[0022] In some embodiments, the positioning mechanism comprises a robot and the feeder is fixedly coupled to the end of a mechanical arm of the robot.

[0023] With this arrangement, the processing efficiency can be significantly improved by utilizing a robot.

[0024] In some embodiments, the spindle motor comprises a clamp suitable for holding a threading tool, a controller suitable for controlling a rotational speed of the spindle motor, and an encoder coupled to the controller configured to: transmit the number of rotations of the spindle motor to the spindle motor controller in a speed control mode so that the controller controls the rotational speed of the spindle motor; and transmit the position of the clamp of the spindle motor holding the threading tool in a position control mode so that the controller controls the output shaft of the spindle motor to rotate to a predetermined position for replacing the threading tool.

[0025] The speed control mode and the position control mode are switched by the control unit according to the machining program. The speed control mode is used by default. When the tool change program is entered and the clamping unit reaches the tool change point, the control mode is switched to the position control mode, the axis of the spindle motor is rotated to the zero point, and the thread cutting tool is taken and changed. In short, the position control mode is only used in the tool change program (stage), and the speed control mode is used by default for other programs.

[0026] With this arrangement, the rotational speed of the spindle motor can be precisely controlled, and the change of thread cutting tools can be easily controlled.

[0027] In some embodiments, the threading tool comprises a tap. Such an arrangement allows for the machining of threads in a cost-effective and reliable manner.

[0028] In a second aspect of the present disclosure, an exemplary embodiment of the present disclosure provides a thread machining method, the method including: driving a thread cutting tool coupled to an output shaft of a spindle motor to rotate at a rotational speed; and driving the spindle motor to move the thread cutting tool along an axial direction of the spindle motor at a moving speed, the moving speed being proportional to the rotational speed during thread machining.

[0029] This arrangement allows for synchronization of feeding and tapping, improving the machining accuracy of the screws.

[0030] In some embodiments, the ratio of translation speed to rotation speed is equal to the pitch of the threading tool.

[0031] This arrangement allows synchronization between feeding and tapping, improving the machining accuracy of the screws.

[0032] In some embodiments, the spindle motor and feeder are synchronized so that the ratio of translation speed to rotation speed during tapping and exiting the threaded hole is equal to the pitch of the threading tool.

[0033] With this arrangement, synchronization between feeding and tapping can be ensured, thereby making it possible to obtain a good thread shape.

[0034] In some embodiments, the spindle motor and feeder are synchronized so that the ratio of translation speed to rotation speed is equal to the pitch of the thread cutting tool, at least from the time the thread cutting tool reaches the hole on the work surface to be machined.

[0035] This arrangement ensures synchronization between the feed and the tap, improving the thread machining accuracy and obtaining a good thread shape.

[0036] In some embodiments, the spindle motor and the feeder are synchronously controlled by the same controller.

[0037] With this arrangement, synchronous control of the spindle motor and the feed device can be easily and reliably achieved.

[0038] In a third aspect of the present disclosure, an exemplary embodiment of the present disclosure provides a system including the above-mentioned thread machining device.

[0039] It should be understood that this summary is not intended to identify key or essential features of the embodiments of the present disclosure, nor to limit the scope of the present disclosure. Other features of the present disclosure will be readily apparent from the following description. [Brief description of the drawings]

[0040] The above and other objects, features and advantages of exemplary embodiments disclosed herein will become more readily understood through the following detailed description, taken in conjunction with the accompanying drawings, in which certain exemplary embodiments disclosed herein are illustrated, by way of example and not limitation, in which: [Figure 1] FIG. 2 is a schematic cross-sectional view of a female screw. [Diagram 2] FIG. [Diagram 3] FIG. 1 is a perspective view of a thread processing device according to an embodiment of the present disclosure. [Figure 4] FIG. 4 is a front view of the thread machining device shown in FIG. [Diagram 5] FIG. 4 is a perspective view of a robot in the screw machining device shown in FIG. [Figure 6] 4 is a plan view of a spindle motor and a feed device of the thread machining device shown in FIG. 3. [Figure 7] FIG. 7 is a perspective view of the spindle motor shown in FIG. [Figure 8] FIG. 2 is a plan view of a feed device according to an embodiment of the present disclosure. [Figure 9] FIG. 9 is a front view of the feed device shown in FIG. 8. [Figure 10] 1 is a schematic plan view illustrating a configuration of a feed device according to an embodiment of the present disclosure. [Figure 11]FIG. 11 is a schematic bottom view of the feeder shown in FIG. [Figure 12] FIG. 13 is a schematic plan view showing a configuration of a feed device according to another embodiment of the present disclosure. [Figure 13] FIG. 13 is a schematic plan view showing a configuration of a feed device according to still another embodiment of the present disclosure. [Figure 14] 1 is a schematic block diagram showing a system including a thread machining device according to an embodiment of the present disclosure.

[0041] In the figures, the same or similar reference numbers are used to denote the same or similar elements. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0042] The principles of the present disclosure will now be described with reference to several exemplary embodiments shown in the drawings. Although exemplary embodiments of the present disclosure are illustrated in the drawings, it should be understood that these embodiments are merely set forth to facilitate those skilled in the art in better understanding and thereby achieving the present disclosure, and are not intended to limit the scope of the present disclosure in any way.

[0043] The terms "comprise" or "include" and variations thereof should be understood as open-ended terms meaning "including, but not limited to." The term "or" should be read as "and / or" unless the context explicitly indicates otherwise. The term "based on" should be understood as "based at least in part on." The term "operable" means that a function, action, movement, or state can be achieved by manipulation performed by a user or an external mechanism. The terms "one embodiment" and "embodiment" should be understood as "at least one embodiment." The term "another embodiment" should be understood as "at least one other embodiment." The terms "first," "second," etc. may refer to different or the same object. The following may include other explicit and implicit definitions. The definitions of terms are consistent throughout the description unless the context explicitly indicates otherwise.

[0044] As described in the Background of the Invention section, conventional thread machining methods have the disadvantages of low efficiency, high cost, and low machining accuracy.

[0045] Generally speaking, there are three methods for thread machining:

[0046] 1. Screw machining on a CNC (Computer Numerical Control) lathe.

[0047] CNC lathes cover a large area, which is not favorable for cooperating with other equipment to realize an automatic production line. The cost of CNC lathes itself is very high. And it needs customized tooling fixtures to adapt to the machining of different workpieces, which reduces the flexibility. In addition, it requires complex programming and high skill of operators.

[0048] 2. Manual tapping.

[0049] As described above, tapping is to screw a tap into a pre-drilled pilot hole on a workpiece with a certain torque and process a female thread on the inner cylindrical surface of the workpiece. Figure 1 shows a schematic cross-sectional view of a female thread, and Figure 2 is a front view of a tap that can be used to manually tap the female thread of Figure 1. This manual tapping has the disadvantages of high labor costs, low efficiency, and low reliability.

[0050] 3. Use a 6-axis industrial robot.

[0051] The 6-axis industrial robot is used to directly mount the spindle motor and the screw tap on its flange for thread processing. However, the 6-axis industrial robot has a problem of insufficient rigidity. If the electric spindle is directly connected to the high-speed thread cutting cutter head in the mechanical structure, the external force generated by the cutter head during high-speed rotation will have a dynamic effect on the transmission mechanism of the robot body, which is very likely to cause unfavorable reaction forces and motion deviations that affect the processing accuracy. In addition, thread processing not only has problems such as high cost, low efficiency, and poor stability, but also has strict requirements for the synchronization of the electric spindle and the tap, as well as other motion mechanisms for thread processing, otherwise motion interference will occur, which will directly affect the quality of the screw.

[0052] In the process of thread machining, because the blade is long, it is easy for the blade to crack or the cutter to bite into the machining surface of the workpiece. In order to ensure accuracy, there must be an appropriate cutting depth and cutting length. The feed rate and rotation speed of the spindle during thread machining must maintain a strict transmission ratio to avoid serious problems such as thread slippage (loosening of the thread), damage to the surface roughness, and damage to the plasticity of the tool material.

[0053] In view of the above, according to an embodiment of the present disclosure, a new thread processing device, method and system are provided in the present invention. The thread processing device includes a spindle motor and a feed device. The spindle motor has an output shaft. The thread cutting tool is connectable to the output shaft of the spindle motor. The spindle motor can drive the thread cutting tool to rotate at a rotational speed. The feed device is movably connected to the spindle motor and can drive the spindle motor to move at a moving speed along the axial direction of the spindle motor. During thread processing, the moving speed can be proportional to the rotational speed. The above idea may be realized in various ways, as will be described in detail in the following paragraphs.

[0054] The principles of the present disclosure will be described in detail below with reference to Figures 3 to 14. First, with reference to Figures 3 to 5, Figure 3 is a perspective view of a thread processing device according to an embodiment of the present disclosure, Figure 4 is a front view of the thread processing device shown in Figure 3, and Figure 5 is a perspective view of the robot shown in Figure 3.

[0055] In some embodiments, as shown in FIG. 3 and FIG. 4, the thread cutting device 300 includes a spindle motor 310 and a feed device 320. The spindle motor 310 is adapted to drive the thread cutting tool 200 coupled to the output shaft of the spindle motor 310 to rotate at a rotational speed. For example, as shown in FIG. 2, the thread cutting tool 200 may be a tap. The feed device 320 is movably coupled to the spindle motor 310 and configured to drive the spindle motor 310 to move at a moving speed along the axial direction X of the spindle motor 310. During thread cutting, the moving speed is proportional to the rotational speed. In some embodiments, the ratio of the moving speed to the rotational speed is equal to the pitch of the thread cutting tool 200. In this way, synchronization between the feed and the tapping can be realized, thereby improving the processing accuracy of the thread.

[0056] In some embodiments, as shown in FIG. 5 , the thread machining apparatus 300 may further include a positioning mechanism 350 fixedly coupled to the feed apparatus 320 and suitable for positioning the feed apparatus 320 such that the thread cutting tool 200 is aligned with a threaded hole to be machined in a workpiece.

[0057] As shown in Figs. 3-5, the positioning mechanism 350 forms the main body of the screw processing device 300. Specifically, the positioning mechanism 350 may be a robot. The robot may be a six-axis industrial robot. The six-axis industrial robot is connected to the feeder 320 at the robot flange 352 to form seven spatial degrees of freedom. The six-axis industrial robot may be installed near the workpiece to be processed. When processing the screw hole, the six-axis industrial robot remains stationary. The spindle motor 310 is coupled to the feeder 320 which moves the threading tool 200 together with the spindle motor 310 in a linear direction. The positioning mechanism 350 can move the feeder 320 to any position within a predetermined range from the positioning mechanism 350. Specifically, the positioning mechanism 350 can move the feeder 320 to a predetermined position such that the output shaft of the spindle motor 310 is aligned with the hole of the workpiece to be processed. In this way, it becomes possible to easily position the output shaft of the spindle motor 310 on the workpiece to be processed.

[0058] An exemplary structure of the thread machining device 300 will be described with reference to Fig. 6 and Fig. 7. Fig. 6 is a plan view of the spindle motor 310 and the feed device 320 of the thread machining device 300 shown in Fig. 3, and Fig. 7 is a perspective view of the spindle motor 310 shown in Fig. 6.

[0059] As shown in Fig. 6, the spindle motor 310 is connected to the feed device 320. Specifically, the spindle motor 310 has a connection part 342 fixedly connected to a connection plate 344 of the feed device 320. The connection plate 344 of the feed device 320 can slide along the axial direction X shown in Fig. 7 by being driven by a drive mechanism in the feed device 320.

[0060] 7, the coupling flange 314 is fixed on the output shaft 312 of the spindle motor 310 and is suitable for connecting the threading tool 200. The spindle motor 310 may further include a clamp 316 used to hold the threading tool 200.

[0061] FIG 8 is a plan view of the feeder 320 according to an embodiment of the present disclosure. FIG 9 is a front view of the feeder 320 shown in FIG 8. In FIG 8, the outer frame of the connection plate of the spindle motor 310 is indicated by 328. A cable train is indicated by 806 in FIG 8 and FIG 9, and is used to feed the cable connecting the feeder 320 and the servo motor 336 to the control cabinet. A terminal box 810 shown in FIG 8 and FIG 9 is used for transferring the cable of the feeder 320, which is convenient for disassembly and maintenance of the feeder 320.

[0062] An exemplary configuration of the feeder 320 will be further described with reference to Figs. 10 to 13. Fig. 10 is a schematic plan view showing the configuration of the feeder 320 according to an embodiment of the present disclosure. Fig. 11 is a schematic bottom view of the feeder 320 shown in Fig. 10. Fig. 12 is a schematic plan view showing the configuration of the feeder 320 according to another embodiment of the present disclosure. Fig. 13 is a schematic plan view showing the configuration of the feeder 320 according to yet another embodiment of the present disclosure.

[0063] In some embodiments, the feeder 320 may include a servo motor 336 and a transmission device 352. The transmission device 352 is coupled to an output shaft of the servo motor 336 and configured to convert rotation of the output shaft of the servo motor 336 into linear movement along the axial direction X of the spindle motor 310 to drive the spindle motor 310. In this way, the spindle motor 310 can achieve accurate linear movement. The transmission device 352 can be configured in various ways, which will be further described in conjunction with FIGS. 10 to 13.

[0064] First, refer to FIG. 10. As shown in FIG. 10, the transmission device 352 generally includes a first belt pulley 321, a belt 324, a second belt pulley 322, a ball screw 339, a ball nut 337, and a slide member 340. The first belt pulley 321 is fixedly connected to an output shaft of a servo motor 336. The second belt pulley 322 is connected to the first belt pulley 321 via a belt 324. The ball screw 339 is connected to the shaft of the second belt pulley 322 at one end and rotates with the second belt pulley 322. The ball screw 339 is connected to a support portion 334 fixedly connected to a base of the feed device 320 at the other end. The ball nut 337 is disposed on the ball screw 339 and configured to move along the axial direction X with the rotation of the ball screw 339. The slide member 340 is coupled between the ball nut 337 and the spindle motor 310. The slide member 340 is driven by the ball nut 337 and moves together with the ball nut 337, thereby driving the spindle motor 310 to move along the axial direction X of the spindle motor 310. In this way, the rotation of the output shaft of the servo motor 336 can be easily and reliably converted into linear movement along the axial direction X of the spindle motor 310. In some embodiments, the slide member 340 is directly connected to the spindle motor 310 and can slide along a track along the axial direction X.

[0065] Figure 11 is a schematic bottom view of the feeder 320 shown in Figure 10. A plate is indicated at 332, allowing the spindle motor 310 to move thereon with the movement of the slide member 340.

[0066] 12, the transmission device 352 generally includes a first belt pulley 321, a gear box 338, a belt 324, a second belt pulley 322, and a slide member 340. The first belt pulley 321 is fixedly connected to an output shaft of the servo motor 336. The second belt pulley 322 is fixedly connected to a shaft of the gear box 338. The belt 324 connects the first belt pulley 321 to the second belt pulley 322, thereby driving the first belt pulley 321 and the second belt pulley 322. The slide member 340 is connected between the gear box 338 and the spindle motor 310, and slides with the rotation of the output shaft of the servo motor 336, thereby driving the spindle motor 310 to move along the axial direction X of the spindle motor 310.

[0067] In some embodiments, the gearbox 338 may include an external gear (not shown) disposed at a first end of the gearbox 338, and at least one internal gear (not shown) disposed within the gearbox 338 and coupled to the external gear. The internal gear is adapted to drive the external gear. The second belt pulley 322 is located at a second end of the gearbox 338, coupled to the shaft of the internal gear of the gearbox 338, and configured to drive the internal gear. The slide member 340 is coupled between the external gear and the spindle motor 310, and drives the spindle motor 310 by sliding with the rotation of the outer gear. In this way, the rotation of the output shaft of the servo motor 336 can be easily and reliably converted into linear movement along the axial direction of the spindle motor 310.

[0068] In some embodiments, the moving speed of the spindle motor 310 is proportional to the product of the circumference of the first belt pulley 321 and the rotation speed of the servo motor 336. In this way, the moving speed of the spindle motor 310 can be easily and accurately controlled.

[0069] The transmission device 352 will be further described with reference to FIG. 13. As shown in FIG. 13, the transmission device 352 generally includes a gear box 338, a ball screw 339, a ball nut 337, and a slide member 340. The gear box 338 is connected to an output shaft of the servo motor 336. The ball screw 339 is movably connected to the gear box 338. The ball nut 337 is disposed on the ball screw 339 and configured to move along an axial direction Y of the ball screw 339 as the ball screw 339 rotates. The slide member 340 is connected between the ball nut 337 and the spindle motor 310. The slide member 340 slides with the movement of the ball nut 337, and drives the spindle motor 310 to move along the axial direction Y of the ball screw 339. In some embodiments, the axial direction Y of the ball screw 339 may be parallel to the axial direction X of the spindle motor 310.

[0070] In some embodiments, the transmission device 352 may further include a slide track (not shown) extending along the axial direction X of the spindle motor 310, and the slide member 340 may slide along the slide track. In this way, the spindle motor 310 can be smoothly driven along the slide track.

[0071] Although the structure of the transmission device 352 has been described above with reference to Figures 10-13, it should be understood that the illustrated configurations are merely examples. The transmission device 352 is not limited to the above-described configurations, but may have any other configuration. The scope of the present disclosure is not intended to be limited in this respect.

[0072] A description will now be given of the thread processing device 300. The thread processing device 300 may be implemented in a variety of configurations in accordance with embodiments of the present disclosure. The scope of the present disclosure is not intended to be limited in this respect.

[0073] The following describes the operation of the thread machining apparatus 300. In some embodiments, a method for thread machining includes driving the thread cutting tool 200 coupled to an output shaft of a spindle motor 310 to rotate at a rotational speed, and driving the spindle motor 310 to move the thread cutting tool 200 along an axial direction X of the spindle motor 310 at a moving speed, wherein the moving speed is proportional to the rotational speed during thread machining.

[0074] In some embodiments, the spindle motor 310 and feeder 320 are synchronized such that the ratio of translation speed to rotation speed during tapping and exiting a threaded hole is equal to the pitch of the threading tool 200.

[0075] In some embodiments, the spindle motor 310 and the feeder 320 are synchronized so that the ratio of the translation speed to the rotation speed is equal to the pitch of the thread cutting tool 200, at least until the thread cutting tool 200 reaches the hole on the workpiece surface to be machined.

[0076] In some embodiments, the spindle motor 310 and the feed device 320 are synchronously controlled by the same controller, so that the synchronous control of the spindle motor and the feed device can be easily and reliably achieved, thereby improving the machining accuracy.

[0077] The operation of the above-described thread cutting device is exemplary only and the scope of the present disclosure is not intended to be limited in this respect.

[0078] An exemplary structure of a thread processing system 1400 including a thread processing device will be described with reference to Fig. 14. Fig. 14 is a schematic block diagram showing a system including a thread processing device according to an embodiment of the present disclosure. As shown in Fig. 14, the thread processing system 1400 may include an integrated control unit 1402, a robot control unit 1404, a positioning device 350, a feed device 320, a spindle motor 310, a thread cutting tool 200, a PLC (Programmable Logic Controller) 1410, a workpiece 1412, an MQL device 1414, and a tool exchange device 1408.

[0079] The core concept of the synchronization algorithm of the present invention is to achieve precise motor synchronization between the linear velocity of the feeder 320 and the rotational speed of the spindle motor 310 by establishing a mathematical and logical relationship between them.

[0080] The present inventors have recognized that in order to obtain high machining accuracy, it is extremely important that the moving speed (feed rate) is proportional to the rotation speed.

[0081] Specifically, during tapping, it is preferable that the feed in the pitch direction, i.e., along the axial direction of the spindle motor 310, maintains a strict speed ratio relationship with the rotation of the spindle motor 310. For each rotation of the spindle motor 310, the total feed amount of the feeder 320 should be equal to the pitch of the tap to achieve synchronization between the feed and the tapping.

[0082] F=P*S1 (1) Here, P represents the pitch of the tap (mm / R) (eg, as shown in FIG. 2), F represents the feed speed of the feeder 320 (mm / min), and S1 represents the rotation speed of the spindle motor 310 (R / min).

[0083] The above relationship between the feed rate of feeder 320 and the rotational speed of spindle motor 310 is merely exemplary, and the scope of the present disclosure is not intended to be limited in this respect.

[0084] From equation (1), it can be derived that the ratio of the moving speed to the rotation speed is equal to the pitch (P shown in FIG. 2) of the thread cutting tool 200. As a result, the processing accuracy of the thread cutting can be significantly improved. For example, thread slippage (loosening of the thread), damage to the surface roughness, damage to the plasticity of the tool material, etc. can be avoided.

[0085] It should be understood that the thread processing device 300 and method of the present invention are not intended to be limited in this respect. The ratio of the moving speed to the rotation speed can vary within a certain range according to the actual requirements, such as from 0.9 times the pitch of the thread cutting tool 200 to 1.1 times the pitch of the thread cutting tool 200, or from 0.95 times the pitch of the thread cutting tool 200 to 1.05 times the pitch of the thread cutting tool 200. A satisfactory thread processing accuracy can also be obtained.

[0086] In some embodiments, the feeder 320 is a motor-pulley configuration, and the relationship between the feed rate F and the feeder 320 may be as follows:

[0087] S2=F / C (2) Here, C represents the circumference of the pulley (mm / R), and S2 represents the rotational speed of the feed device 320 (R / min).

[0088] This formula (2) does not take into account the transmission ratio of other transmission mechanisms in the feeder 320. If the transmission ratio is taken into account, this formula needs to be multiplied by the corresponding coefficient. In short, in some embodiments, the moving speed is proportional to the product of the circumference of the first belt pulley 321 and the rotation speed of the servo motor 336.

[0089] To accommodate machining of different types of threaded holes, the tool changer 1408 may interface with the tool / tool ​​holder 1406 to automatically change tools.

[0090] The head of the thread cutting tool 200 may be equipped with a peripheral micro lubricating fluid (MQL) device 1414 that provides an atomized spray during thread cutting to improve feed rates, reduce heat buildup, reduce tool wear, and extend the life of the thread cutting tool 200.

[0091] The PLC 1410 may communicate with the robot controller 1404, execute and control the task list, and enforce security measures.

[0092] The integrated controller 1402 has a compact layout and design. It integrates the driving of the feeder 320 and the spindle motor 310 for one-drive-two-synchronous control. Its synchronization is good, and the delay of the system can be avoided.

[0093] Based on the integrated controller design and the unique advantages of the physical structure and encoder software programming, a motor synchronization algorithm in the feed and withdraw process of thread machining is realized.

[0094] In the above embodiment, the machining of a female thread has been described as an example. In fact, the thread machining device 300 and method of the present invention are not intended to be limited in this respect. The thread machining device and method of the present invention can be applied to male thread machining as long as the spindle motor is equipped with the thread cutting tool 200 for machining a male thread.

[0095] It should be understood that the device is not limited to the configurations described above, but may be in any other configuration, and the scope of the present disclosure is not intended to be limited in this respect.

[0096] Additionally, this device may operate in combination with one or more additional devices, as desired. The scope of the present disclosure is not intended to be limited in this respect.

[0097] The optimization solution provided by the embodiment of the present invention solves the above problems of high cost, low efficiency, low stability and out-of-synchronization. A feeder, such as a single-axis servo flexible positioning device, may be added to the 6-axis industrial robot, and the spindle motor and the thread cutting tool 200 are mechanically connected. In addition, in order to better realize the synchronization between the linear movement of the spindle motor and the rotational movement of the spindle motor, the physical connection and synchronization algorithm between the feeder and the spindle motor are designed to solve the problem of the motor speeds being out of synchronization, which is caused by the independent control, which causes the problem that the two devices cannot be controlled and related by the same process algorithm, and avoids thread slippage and cutter sticking.

[0098] The innovative optimization solution provided by the embodiment of the present invention takes advantage of the flexibility and economy of industrial robots, specifically, adding a single-axis servo flexible positioner (feeder) as an intermediate motion mechanism to reduce the mechanical shock to the robot, thus solving the problem of insufficient robot stiffness.

[0099] In addition, the embodiment of the present disclosure allows the integrated design of the single-axis servo flexible positioning device and the drive unit of the spindle motor. The synchronous control becomes more flexible, and the synchronous speed delay of the spindle motor in the same system can be effectively reduced. The solution of the present invention greatly improves the cost, efficiency, stability and accuracy of thread processing.

[0100] While several inventive embodiments have been described and illustrated herein, those skilled in the art may readily conceive of various other means and / or structures for performing the functions and / or obtaining the results and / or one or more advantages described herein, and each such variation and / or modification is deemed to be within the scope of the inventive embodiments described herein. More generally, those skilled in the art will readily appreciate that all parameters, dimensions, materials, and configurations described herein are meant to be exemplary, and that the actual parameters, dimensions, materials, and / or configurations will depend on the particular application in which the teachings of the present invention are used. Those skilled in the art will recognize or be able to ascertain, using no more than routine experimentation, many equivalents to the specific inventive embodiments described herein. Thus, the above embodiments are presented by way of example only, and it should be understood that, within the scope of the appended claims and equivalents thereof, the present disclosure relates to each individual feature, system, article, material, kit, and / or method described in the present invention. Additionally, combinations of two or more such features, systems, articles, materials, kits, and / or methods are within the scope of the present disclosure, if such features, systems, articles, materials, kits, and / or methods are not mutually inconsistent.

Claims

1. A screw processing device (300), a spindle motor (310) adapted to drive a threading tool (200) coupled to an output shaft of the spindle motor (310) in rotation at a rotational speed; a feeder (320) movably coupled to the spindle motor (310) and configured to drive the spindle motor (310) to move at a moving speed along an axial direction (X) of the spindle motor (310); During thread machining, the moving speed is proportional to the rotation speed. Thread processing device (300).

2. The ratio of the translation speed to the rotation speed is equal to the pitch of the thread cutting tool (200). The thread machining device (300) of claim 1.

3. The feed device (320) A servo motor (336); a transmission device (352) connected to the output shaft of the servo motor (336) and configured to convert rotation of the output shaft of the servo motor (336) into linear movement along the axial direction (X) of the spindle motor (310) to drive the spindle motor (310); The thread machining device (300) of claim 1, comprising:

4. The transmission device (352) is a gear box (338) connected to the output shaft of the servo motor (336); a ball screw (339) movably connected to the gear box (338); a ball nut (337) disposed on the ball screw (339) and configured to move along an axial direction (Y) of the ball screw (339) as the ball screw (339) rotates; a slide member (340) that is connected between the ball nut (337) and the spindle motor (310) and slides with the movement of the ball nut (337), thereby driving the spindle motor (310) to move along the axial direction (Y) of the ball screw (339); The thread machining device (300) of claim 3, comprising:

5. The transmission device (352) is A first belt pulley (321) fixedly connected to an output shaft of the servo motor (336); A gear box (338); a second belt pulley (322) fixedly connected to the shaft of said gearbox (338); a belt (324) for connecting the first belt pulley (321) to the second belt pulley (322) to drive the first belt pulley (321) and the second belt pulley (322); a slide member (340) connected between the gear box (338) and the spindle motor (310), and sliding with rotation of the output shaft of the servo motor (336), thereby driving the spindle motor (310) to move along the axial direction (Y) of the spindle motor (310); The thread machining device (300) of claim 3, comprising:

6. The transmission device (352) is A first belt pulley (321) fixedly connected to an output shaft of the servo motor (336); A belt (324); a second belt pulley (322) connected to the first belt pulley (321) via the belt (324); a ball screw (339) connected to a shaft of the second belt pulley (322) and rotating in accordance with the rotation of the second belt pulley (322); a ball nut (337) disposed on the ball screw (339) and configured to move along an axial direction (Y) of the ball screw (339) as the ball screw (339) rotates; a slide member (340) that is connected between the ball nut (337) and the spindle motor (310) and slides with the movement of the ball nut (337), thereby driving the spindle motor (310) to move along the axial direction (X) of the spindle motor (310); The thread machining device (300) of claim 3, comprising:

7. The moving speed is proportional to the product of the circumference of the first belt pulley (321) and the rotation speed of the servo motor (336). Thread machining device (300) according to claim 5 or 6.

8. The transmission device (352) further includes a slide track extending along the axial direction (X) of the spindle motor (310), and the slide member (340) slides along the slide track. A thread machining device (300) according to any one of claims 4 to 6.

9. and a positioning mechanism (350) fixedly connected to the feeder (320) and adapted to position the feeder (320) to align the threading tool (200) with a threaded hole to be machined in a workpiece. The thread machining device (300) of claim 1.

10. The positioning mechanism (350) comprises a robot, and the feeder (320) is fixedly connected to the end of a mechanical arm of the robot.

10. The thread machining device (300) of claim 9.

11. The spindle motor (310) a clamp (316) suitable for holding said threading tool (200); a controller adapted to control the rotation speed of the spindle motor (310); an encoder coupled to the controller, In a speed control mode, the rotation speed of the spindle motor (310) is transmitted to the control unit of the spindle motor (310) so that the control unit controls the rotation speed of the spindle motor (310); and Transmitting the position of the clamping part of the spindle motor (310) holding the thread cutting tool (200) in a position control mode so as to control the output shaft of the spindle motor (310) to rotate the thread cutting tool (200) to a predetermined position for replacing the thread cutting tool (200); the encoder configured to: The thread machining device (300) of claim 1, comprising:

12. The threading tool (200) comprises a tap A thread machining device (300) according to any one of the preceding claims.

13. A thread processing method, comprising the steps of: Driving a threading tool (200) coupled to an output shaft of a spindle motor (310) to rotate at a rotational speed; Driving the spindle motor (310) to move the spindle motor (310) at a moving speed along an axial direction (X) of the spindle motor (310); During thread processing, the moving speed is proportional to the rotation speed. Screw machining method.

14. The ratio of the translation speed to the rotation speed is equal to the pitch of the thread cutting tool (200). The thread machining method according to claim 13.

15. The spindle motor (310) and the feeder (320) are synchronized such that the ratio of the translation speed to the rotation speed during tapping and exiting from the screw hole is equal to the pitch of the threading tool (200). The thread machining method according to claim 13.

16. The spindle motor (310) and the feeder (320) are synchronously controlled so that the ratio of the moving speed to the rotation speed is equal to the pitch of the thread cutting tool (200), at least after the thread cutting tool (200) has reached a hole on a workpiece surface to be threaded. The thread machining method according to claim 13.

17. The spindle motor (310) and the feed device (320) are synchronously controlled by the same control unit. The thread machining method according to claim 13.

18. The screw processing device (300) according to any one of claims 1 to 12 is provided. Thread machining system (1400).

Images