Numerically controlled slot milling machine

Abstract

The application discloses a numerical control slot milling machine tool, which comprises a machine tool workbench, a milling mechanism, a main shaft box, a tool automatic replacement mechanism, a center frame, a tail frame, a fixed protective cover, a double-open electric door and a numerical control system, wherein the numerical control system is connected with the milling mechanism, the main shaft box, the tail frame, the center frame and the double-open electric door respectively; the machine tool is combined with the tail frame and the center frame which can be synchronously and accurately moved through the multi-degree-of-freedom milling mechanism, and thus the vibration and deformation problems in the machining of an ultra-long workpiece and a complex slot type are solved fundamentally, high machining precision and surface quality are realized, and an online intelligent detection system is integrated to realize real-time quality monitoring and closed-loop control in the machining process.

Description

Technical Field

[0001] This invention relates to the field of CNC machine tools, and more specifically to a CNC slot milling machine tool. Background Technology

[0002] A spiral groove is a helical groove structure machined on a cylindrical or flat surface. Spiral grooves are widely used, particularly in engineering machinery where many bushing-type parts have them. Spiral grooves can be further categorized by angle, shape, and number, such as those with a rhomboid or elliptical cross-section, or double spiral groove structures. Traditionally, milling, turning, or grinding are used for machining these grooves, but these methods are complex and require intricate calculations before machining. Machining more complex spiral grooves, such as rhomboid or double grooves, requires multiple clamping and machining passes, and some even require specialized tooling. A single clamping operation cannot complete all machining steps, increasing both time and cost. Currently, there are CNC machine tools for machining spiral grooves, such as the one described in Chinese patent number ZL2020221370. Patent 15.6 discloses a CNC spiral groove milling machine to solve the problems of incomplete machining and poor machining accuracy of existing special-purpose machine tools. This patent first clamps the workpiece in a three-jaw chuck, then moves the internal milling power head laterally and longitudinally along the X-axis motor and lead screw drive and the Y-axis motor and lead screw drive, aligning the milling cutter head with the workpiece in the three-jaw chuck. The machining angle is adjusted by rotating the CNC indexing head, and then the internal milling power head is activated to drive the milling cutter to rotate at high speed. This allows for thorough machining, high precision, and a compact machining process, reducing the usable area of ​​the machine tool and minimizing wear and tear. However, this patent can only machine workpieces within the three-jaw chuck, limiting the machining length and preventing the machining of long workpieces. It also cannot support long workpieces during machining, and the dimensions of the workpiece during machining cannot be monitored in real time.

[0003] There are also multi-point fixed support structures for machining long workpieces. However, multi-point fixed support structures need to be frequently loosened, clamped, and moved away along the direction of the milling mechanism during the milling process. Otherwise, it will affect the movement of the milling mechanism and the machining of the workpiece. Furthermore, as the milling mechanism moves, the distance between the support point on the workpiece and the cutting point of the tool on the workpiece will change continuously, thus affecting the stability of the support, the machining quality of the workpiece, and the machining efficiency of the machine tool.

[0004] Therefore, although special-purpose machine tools have become essential tools for the machining industry to process such products and improve their quality and efficiency, many mechanical equipment uses outdated technologies that cannot keep up with the progress of industrialization. In particular, milling machines have many technical problems, such as workpiece processing length, spiral groove cross-sectional shape, number of spiral grooves, and automated monitoring during the processing. This results in long processing time, low efficiency, inability to guarantee accuracy and product quality, and a large number of defective products, failing to achieve the ideal processing effect. Summary of the Invention

[0005] In view of the shortcomings of the prior art, the purpose of this invention is to provide a CNC milling machine tool.

[0006] The technical solution adopted by this invention to solve its technical problem is: A CNC milling machine tool includes a machine tool worktable, a milling mechanism movably mounted in the middle of the machine tool worktable, a spindle box fixedly mounted at one end above the machine tool worktable, an automatic tool changing mechanism fixedly mounted on the top of the spindle box, a center frame mounted above the machine tool worktable to support the workpiece in conjunction with the milling mechanism, a tailstock movably mounted at the other end above the machine tool worktable near the milling mechanism, a fixed protective shell fixedly mounted on the machine tool worktable to prevent chip splashing, a double-opening electric door installed in conjunction with the fixed protective shell, and a CNC system installed on the double-opening electric door. The CNC system is connected to the milling mechanism, the spindle box, the center frame, the double-opening electric door, and the tailstock respectively. The center frame and the milling mechanism are located on both sides of the spindle centerline of the spindle housing. The center frame includes a center frame slide, a workpiece support seat movably mounted on the upper part of the center frame slide, and a workpiece chuck embedded in the upper part of the workpiece support seat with its clamping opening facing the spindle centerline of the spindle housing. A cylinder is fixedly mounted on one end of the center frame slide and its output end is fixedly mounted to the workpiece support seat. A support seat guide rail is fixedly mounted on the upper end of the center frame slide by bolts, and a support seat guide slider that cooperates with the support seat guide rail is fixedly mounted on the lower end of the workpiece support seat by bolts. The workpiece chuck includes a chuck double-headed cylinder embedded in the upper end of the workpiece support, a chuck hook hinged to the output end of the chuck double-headed cylinder, a chuck hook rolling element installed at the end of the chuck hook, a front push cylinder embedded in the middle part of the chuck double-headed cylinder, and a front push rolling element installed at the output end of the front push cylinder. The center frame also includes a servo translation motor with a built-in reduction mechanism and gears mounted on the upper side of the center frame slide, and a spur rack mounted on the machine tool worktable and meshing with the gears of the servo translation motor. The center frame also includes a scraper rod fixedly installed on one side of the lower end of the center frame slide by bolts, scrapers symmetrically welded to the bottom of the center frame slide, and a workpiece quality inspection device installed on the center frame slide. The workpiece quality inspection device includes a base fixedly installed with the central frame slide, a multi-degree-of-freedom robotic arm mounted on the base, and an arc-shaped inspection strip mounted on the multi-degree-of-freedom robotic arm for approaching the workpiece. The arc-shaped detection strip includes an arc-shaped strip body, an arc-shaped groove formed inside the arc-shaped strip body, and a laser interferometer, a camera, and an ultrasonic probe that are sequentially fixed inside the arc-shaped groove; the ultrasonic probe is an air-coupled ultrasonic probe. Two center frames are provided, and the two center frames are respectively located in front of and behind the milling mechanism along the moving direction of the milling mechanism; When the milling mechanism is milling a workpiece, the CNC system calculates and controls the moving speed and distance of the center frame by the moving speed of the milling mechanism and the distance between the center frame and the milling mechanism, so that the center frame and the milling mechanism move synchronously.

[0007] Furthermore, the machine tool worktable includes a worktable body, a chip collection groove with a chip discharge port that is bolted to the front end of the worktable body, an automatic chip conveyor that is embedded in the lower end of the worktable body and connected to the CNC system and works with the chip collection groove to clean chips, a first mounting groove opened at the upper end of the worktable body, milling mechanism linear guides that are bolted to both sides of the first mounting groove, a milling mechanism drive screw mechanism that is installed inside the first mounting groove for driving the displacement of the milling mechanism, a second mounting groove opened at the lower end of the worktable body and with a chip discharge port, a tailstock drive screw mechanism that is installed inside the second mounting groove for driving the displacement of the tailstock, and an inclined support seat located at one end of the second mounting groove for fixing the spindle box; the worktable body is inclined.

[0008] Furthermore, the fixed protective shell includes a back panel fixedly installed with the machine tool worktable, and side guards located on both sides of the back panel and fixedly installed with the machine tool worktable by bolts; the double-opening electric door is assembled on the outside of the side guards.

[0009] Furthermore, the milling mechanism includes a large milling slide, a middle milling slide mounted on the large milling slide, a middle slide drive screw mechanism mounted in the middle of the upper part of the large milling slide for driving the middle milling slide to move, a C-axis rotation mechanism mounted on the upper part of the middle milling slide via a round shaft, a C-shaped rack detachably mounted on the lower end of the C-axis rotation mechanism, a steering drive motor fixedly mounted on the upper part of the middle milling slide, equipped with gears and meshing with the C-shaped rack, a vertical slide assembled on the inner side of the upper end of the C-axis rotation mechanism, a tool holder fixedly mounted on the vertical slide and equipped with a tool, and a vertical screw drive motor mounted on the outer side of the upper end of the C-axis rotation mechanism.

[0010] Preferably, the steering drive motor has a built-in reduction mechanism, with a gear installed at the front end of the reduction mechanism, and the gear meshing with a C-shaped rack; The lower end of the large milling slide is fixed with a milling mechanism guide slider by bolts, and the upper end of the large milling slide is fixed with a milling middle slide guide rail by bolts. The inner side of the C-axis rotating mechanism is fixed with two parallel vertical guide rails by bolts, and a vertical lead screw that drives the vertical slide plate to move is installed between the two vertical guide rails. The vertical lead screw and the vertical lead screw drive motor are connected by a belt. The milling mechanism guide slider is assembled with the milling mechanism linear guide rails on both sides of the first mounting groove.

[0011] Furthermore, the claw-shaped rolling element and the front-mounted rolling element are either balls or rollers.

[0012] Furthermore, the servo translation motor is connected to the CNC system and is used to drive the center support slide to move along the machine tool table.

[0013] Preferably, the scraper bar extends into the chip collection groove.

[0014] The beneficial effects of this invention are: (1) By coordinating the control of the CNC system with the milling large slide, milling middle slide, vertical slide and C-axis rotation mechanism, the tool can be accurately positioned and moved in at least four degrees of freedom, and can be used to mill grooves on the workpiece. The spindle box and tailstock can effectively clamp the workpiece. At the same time, the movable tailstock expands the length range of the workpiece, so that both long and short workpieces can be processed. (2) The center rest can be positioned according to the workpiece length and machining position by means of cylinders and servo translation motors, always providing stable support for the workpiece. This effectively suppresses bending deformation and vibration caused by excessive workpiece overhang or cutting force, ensuring machining dimensional accuracy and surface finish. Moreover, when machining extra-long workpieces, the CNC system calculates and controls the moving speed and distance of the center rest by means of the milling mechanism's moving speed and the distance between the center rest and the milling mechanism, so that the center rest and the milling mechanism move synchronously. Through threshold setting and time cut-off, the system monitors the following error and the clamping state of the center rest on the workpiece in real time and adjusts it automatically, thereby controlling the movement of the center rest and the milling mechanism. The precise synchronization of the cutting mechanism ensures that the corresponding position near the cutting point of the tool is always rigidly supported, replacing some multi-point fixed clamping support devices used for machining ultra-long workpieces. This solves the problems faced by multi-point fixed clamping support devices, such as the support device hindering the movement of the milling mechanism due to continuous movement, requiring frequent moving away or forwarding, greatly reducing the working efficiency of the machine tool, and the distance between the support point and the cutting point constantly changing with the movement of the milling mechanism, resulting in unstable support points and unstable support force. It fundamentally avoids chatter and torsion, and improves the machining stability when machining deep grooves such as rhomboid grooves, elliptical grooves, or double grooves or heavy-duty cutting. (3) The center frame and tailstock are mounted on different mounting slots on the machine tool worktable, which makes full use of the increased usable area of ​​the inclined worktable body. This can completely avoid the influence of the center frame on the movement of the milling mechanism, ensuring high-quality processing of the entire length of the workpiece by the milling mechanism. At the same time, the center frame can be set in the front and back directions of the milling mechanism, which further strengthens the support of the milling mechanism for processing the workpiece, preventing vibration and torsion. It is especially suitable for processing slender workpieces, and can further improve the processing quality and efficiency of the workpiece. (4) The workpiece quality inspection device integrates a laser interferometer, a camera and an ultrasonic probe. It can perform non-contact online inspection of the surface roughness, grooving size and crack defects of the workpiece during processing or during processing intervals. It also maintains the normal operation of the laser interferometer, camera and ultrasonic probe by compressed gas blowing and other methods, realizing the integration of processing and inspection. It can detect defective products in time, reduce subsequent inspection links, and ensure that the products are qualified as soon as they are taken off the production line. (5) Equipped with an automatic tool changing mechanism, it can reduce non-machining auxiliary time. The tilting worktable design, combined with the automatic chip conveyor, chip collection trough and the chip scraper and scraper attached to the center frame, realizes the automatic and efficient collection and removal of cutting chips, keeps the working area clean, ensures the reliability of long-term operation of the equipment, reduces the labor intensity of manual cleaning, and improves the environmental performance of the machine tool. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the structure of Embodiment 1 of the present invention; Figure 2 for Figure 1 A schematic diagram of the back structure; Figure 3 for Figure 1 A combined structural diagram of the machine tool's worktable, milling mechanism, spindle box, automatic tool changing mechanism, center rest, and tailstock; Figure 4 for Figure 3 Structural diagram of the milling mechanism; Figure 5 for Figure 3 Structural diagram of the central frame; Figure 6 for Figure 5 Structural diagram of the workpiece chuck; Figure 7 This is a schematic diagram of the central frame structure in Embodiment 2 of the present invention; Figure 8 This is a schematic diagram of the structure of Embodiment 3 of the present invention; Figure 9 This is a combined structural diagram of the machine tool worktable, milling mechanism, spindle box, automatic tool changing mechanism, center rest and tailstock in Embodiment 3 of the present invention; Figure 10 for Figure 9 Structural diagram of the central frame; Figure 11 for Figure 10 Bottom structure diagram; Figure 12 for Figure 10 Structural diagram of the workpiece quality inspection device; Figure 13 for Figure 12 Structural diagram of the arc-shaped detection strip; Figure 14 This is a flowchart illustrating the synchronous movement of the milling mechanism and the center frame behind it controlled by the CNC system.

[0016] Figure 1-14In the middle section, the machine tool includes a worktable 1, a worktable body 11, a chip collection groove 12, an automatic chip conveyor 13, a first mounting slot 14, a linear guide rail for the milling mechanism 15, a lead screw mechanism for the milling mechanism 16, a second mounting slot 17, a tailstock drive lead screw mechanism 18, an inclined support seat 19, a milling mechanism 2, a large milling slide 21, a guide slider for the milling mechanism 211, a guide rail for the middle milling slide 212, a middle milling slide 22, a lead screw mechanism for the middle slide 23, a C-axis rotation mechanism 24, a vertical guide rail 241, a vertical lead screw 242, a C-shaped rack 25, a steering drive motor 26, a vertical slide 27, a tool holder 28, a vertical lead screw drive motor 29, a spindle box 3, an automatic tool changing mechanism 4, and a center rest 5. 51. Center frame slide plate, 511. Support base guide slide rail, 52. Workpiece support base, 521. Support base guide slider, 53. Workpiece chuck, 531. Double-headed chuck cylinder, 532. Claw hook, 533. Claw hook rolling element, 534. Front lifting cylinder, 535. Front lifting rolling element, 54. Cylinder, 55. Servo translation motor, 56. Straight rack, 57. Scraper bar, 58. Scraper, 59. Workpiece quality inspection device, 591. Base, 592. Multi-degree-of-freedom robotic arm, 593. Arc-shaped inspection strip, 5931. Arc-shaped strip body, 5932. Arc-shaped groove, 5933. Laser interferometer, 5934. Camera, 5935. Ultrasonic probe, 6. Tailstock, 7. Fixed protective shell, 71. Back baffle, 72. Side baffle, 8. Double electric door, 9. CNC system. Detailed Implementation

[0017] The present invention will be further described below with reference to the accompanying drawings and specific embodiments, so that those skilled in the art can better understand and implement the present invention, but the embodiments are not intended to limit the present invention. Example 1

[0018] like Figure 1-3 As shown, a CNC milling machine tool includes a machine tool table 1, a milling mechanism 2 movably mounted in the middle of the machine tool table 1, a spindle housing 3 fixedly mounted on one end of the machine tool table 1, an automatic tool changing mechanism 4 fixedly mounted on the top of the spindle housing 3, a center support 5 mounted on the machine tool table 1 to support the workpiece in conjunction with the milling mechanism 2, a tailstock 6 movably mounted on the other end of the machine tool table 1 near the milling mechanism 2, and a fixed protective shell 7 fixedly mounted on the machine tool table 1 to prevent chip splashing. The double-opening electric door 8 is installed in conjunction with the fixed protective shell 7, and the CNC system 9 is installed on the double-opening electric door 8. The workpiece is fixed between the spindle box 3 and the tailstock 6. Workpieces of different lengths can be clamped by moving the tailstock 6 and adjusting the distance between the tailstock 6 and the spindle box 3. The CNC system 9 is connected to the milling mechanism 2, the spindle box 3, the center support 5, the double-opening electric door 8 and the tailstock 6 respectively. The fixed protective shell 7 can also prevent processing debris and other materials from splashing outside the machine tool during operation, which can protect the cleanliness of the production site and improve environmental protection and safety.

[0019] The machine tool worktable 1 includes a worktable body 11, a chip collection groove 12 with a chip discharge port that is bolted to the front end of the worktable body 11, an automatic chip conveyor 13 that is embedded in the lower end of the worktable body 11 and connected to the CNC system, and works with the chip collection groove 12 to clean chips, a first mounting groove 14 that is opened at the upper end of the worktable body 11, milling mechanism linear guide rails 15 that are bolted to both sides of the first mounting groove 14, a milling mechanism drive screw mechanism 16 that is installed inside the first mounting groove 14 for driving the displacement of the milling mechanism 2, a second mounting groove 17 with a chip discharge port that is opened at the lower end of the worktable body 11, a tailstock drive screw mechanism 18 that is installed inside the second mounting groove 17 for driving the displacement of the tailstock 6, and an inclined support seat 19 located at one end of the second mounting groove 17 for fixing and mounting the spindle box 3.

[0020] It should be further explained that the automatic chip conveyor 13 is connected to the CNC system 9 and is controlled by it to work; the CNC system 9 realizes the movement control of the tailstock 6 by connecting to the tailstock drive screw mechanism 18 of the tailstock 6.

[0021] In this embodiment, the worktable body 11 is inclined, and the chips generated by cutting can naturally slide into the chip collection groove 12 at the front end under the action of gravity, thereby improving the chip removal efficiency.

[0022] The fixed protective shell 7 includes a back baffle 71 that is fixedly installed to the machine tool worktable 1 by bolts, and side baffles 72 that are fixedly installed to the machine tool worktable 1 and located on both sides of the back baffle 71 by bolts. Specifically, the double electric door 8 is assembled on the outside of the side baffles 72 to facilitate the opening and closing of the double electric door 8.

[0023] like Figure 4 As shown, the milling mechanism 2 includes a large milling slide 21, a middle milling slide 22 mounted on the large milling slide 21, a middle slide drive screw mechanism 23 mounted on the upper middle part of the large milling slide 21 for driving the middle milling slide 22 to move, a C-axis rotation mechanism 24 mounted on the middle milling slide 22 via a round shaft, a C-shaped rack 25 detachably mounted on the lower end of the C-axis rotation mechanism 24, a steering drive motor 26 fixedly mounted on the middle milling slide 22, equipped with gears and meshing with the C-shaped rack 25, a vertical slide 27 assembled on the inner side of the upper end of the C-axis rotation mechanism 24, a tool holder 28 fixedly mounted on the vertical slide 27 and equipped with a tool, and a vertical screw drive motor 29 mounted on the outer side of the upper end of the C-axis rotation mechanism 24.

[0024] Specifically, the steering drive motor 26 has a built-in reduction mechanism, and a gear is installed at the front end of the reduction mechanism. Through the meshing of the gear with the C-shaped rack 25, the C-direction rotation mechanism 24 can be driven to work stably.

[0025] The lower end of the milling slide 21 is fixed with a milling mechanism guide slider 211 by bolts, and the upper end of the milling slide 21 is fixed with a milling slide guide rail 212 by bolts.

[0026] The inner side of the C-axis rotating mechanism 24 is fixedly installed with two parallel vertical guide rails 241 by bolts, and a vertical lead screw 242 for driving the vertical slide plate 27 is installed between the two vertical guide rails 241. The vertical lead screw 242 is connected to the vertical lead screw drive motor 29 by a belt, and the vertical lead screw 242 can be driven by the vertical lead screw drive motor 29 to drive the vertical slide plate 27 to adjust its vertical displacement.

[0027] It should be further explained that the large milling slide 21 drives the milling mechanism 2 to move along the length of the worktable, i.e., the Z-direction, while the middle milling slide 22 drives the tool holder 28 to move along the front-back direction, i.e., the X-direction. The C-direction rotation mechanism 24 is installed on the middle milling slide 22 and drives the tool holder 28 to rotate at any angle in a direction perpendicular to the plane of the middle milling slide 22, which can facilitate the processing of various helical angles. The vertical slide 27 is installed at the bottom of the C-direction rotation mechanism 24 and drives the tool holder 28 to move up and down, i.e., move in the Y-direction.

[0028] The milling mechanism guide slider 211 is assembled with the milling mechanism linear guide rails 15 on both sides of the first mounting groove 14. It plays a guiding role when the milling mechanism drive screw mechanism 16 drives the milling mechanism 2 to move, and enables the milling mechanism 2 to move smoothly and accurately. At the same time, the milling middle slide guide rail 212 facilitates the middle slide drive screw mechanism 23 to start the milling middle slide 22 to move smoothly and accurately. The vertical screw drive motor 29 drives the vertical screw 242 to drive the vertical slide 27 to make precise up and down displacement adjustments, so that the tool holder 28 can accurately contact the tool with the workpiece. This not only improves the milling accuracy of the workpiece, but also improves the surface finish of the milled surface of the workpiece, and also facilitates precise displacement when machining spiral grooves with asymmetrical cross-sections.

[0029] like Figure 5-6 As shown, the center frame 5 includes a center frame slide 51, a workpiece support seat 52 movably mounted on the upper end of the center frame slide 51, a workpiece chuck 53 embedded in the upper end of the workpiece support seat 52 with its mounting opening facing the spindle centerline of the spindle housing 3, and a cylinder 54 fixedly mounted above one end of the center frame slide 51 with its output end fixedly mounted to the workpiece support seat 52.

[0030] The upper end of the center frame slide plate 51 is fixedly mounted with a support seat guide slide rail 511 by bolts, and the lower end of the workpiece support seat 52 is fixedly mounted with a support seat guide slider 521 that cooperates with the support seat guide slide rail 511 by bolts.

[0031] Specifically, the workpiece chuck 53 includes a chuck double-headed cylinder 531 embedded in the upper end of the workpiece support 52, a claw hook 532 hinged to the chuck double-headed cylinder 531 and connected to the output end of the chuck double-headed cylinder 531, a claw hook rolling element 533 installed at the end of the claw hook 532, a front-lifting cylinder 534 embedded in the middle part of the chuck double-headed cylinder 531, and a front-lifting rolling element 535 installed on the output end of the front-lifting cylinder 534. Specifically, when the workpiece chuck 53 is assembled with the workpiece, the claw hook 532 is driven by the chuck double-headed cylinder 531 to hug the workpiece, so that the claw hook rolling element 533 contacts the workpiece. At the same time, the front-lifting cylinder 534 extends, so that the front-lifting rolling element 535 abuts against the workpiece. Together with the claw hook rolling element 533 of the workpiece chuck 53, three fulcrums are formed to clamp the workpiece, but the rotation of the workpiece is not affected. This can effectively reduce the vibration of the workpiece during processing and prevent torsion.

[0032] It should be further noted that the claw-hook rolling element 533 and the front-mounted rolling element 535 are either balls or rollers. In this embodiment, the claw-hook rolling element 533 and the front-mounted rolling element 535 are rollers.

[0033] It should be further explained that, through the cooperation of the support base guide slide rail 511 and the support base guide slider 521, the cylinder 54 can smoothly drive the workpiece support base 52 to move and adjust, so that the workpiece chuck 53 can support workpieces of different specifications and models, meet the anti-vibration requirements of different groove machining, prevent the workpiece from being affected by tool vibration or torsional force due to cutting by the tool during the machining process, and also avoid the milling mechanism 2 from being unable to accurately mill due to the workpiece being too long and bending deformation.

[0034] It should be further explained that the center frame 5 is mounted on the second mounting slot 17 via the center frame slide 51 to avoid affecting the movement of the milling mechanism 2.

[0035] It should be further explained that a tool guard is installed above the tool holder 28 to prevent the impact of debris. The workpiece and tool are cooled by compressed gas blowing, which can not only meet the cooling requirements of the workpiece and tool, but also avoid the pollution of the on-site equipment and environment by the coolant. Example 2

[0036] The difference between this embodiment 2 and embodiment 1 lies in the structural change of the central frame 5.

[0037] like Figure 7As shown, the center frame 5 includes a center frame slide 51, a workpiece support seat 52 movably mounted on the upper end of the center frame slide 51, a workpiece chuck 53 embedded in the upper end of the workpiece support seat 52 with its mounting opening facing the spindle centerline of the spindle housing 3, a cylinder 54 fixedly mounted above one end of the center frame slide 51 with its output end fixedly mounted to the workpiece support seat 52, a servo translation motor 55 mounted on one side of the upper end of the center frame slide 51, and a rack 56 mounted on the machine tool worktable 1 and cooperating with the servo translation motor 55.

[0038] The servo translation motor 55 is connected to the CNC system 9 and is used to drive the center frame slide to move along the machine tool worktable 1.

[0039] Specifically, the servo translation motor 55 has a built-in reduction mechanism, which is equipped with gears. The gears mesh with the rack 56, which can drive the center frame slide plate 51 to move and work stably.

[0040] The upper end of the center frame slide plate 51 is fixedly mounted with a support seat guide slide rail 511 by bolts, and the lower end of the workpiece support seat 52 is fixedly mounted with a support seat guide slider 521 that cooperates with the support seat guide slide rail 511 by bolts.

[0041] Combined with appendix Figure 1-4 and attached Figure 6 The cylinder 54 can smoothly drive the workpiece support 52 to move and adjust by the cooperation of the support base guide slide rail 511 and the support base guide slider 521, so that the workpiece chuck 53 can support the processing of workpieces of different specifications and different groove shapes, and prevent the workpiece from bending and deforming due to excessive length, which would prevent the milling mechanism 2 from accurately milling.

[0042] Furthermore, the milling mechanism 2 is controlled by the CNC system 9 to drive the lead screw mechanism 16 to smoothly mill the workpiece. Meanwhile, the center support 5 is controlled by the CNC system 9 to move in conjunction with the servo translation motor 55 and the rack 56. This avoids the center support 5 from obstructing the translation of the milling mechanism 2. When machining extra-long workpieces, the CNC system can also control the center support 5 and the milling mechanism 2 to move synchronously, ensuring that the milling part of the workpiece is stably supported synchronously. This better prevents workpiece vibration and deformation, and is more conducive to improving machining accuracy and milling surface finish, as well as improving machining efficiency.

[0043] It should be noted that, as Figure 14 As shown, the process by which the CNC system control center frame 5 and the milling mechanism 2 move synchronously during the milling of the workpiece by the milling mechanism 2 is as follows: S1: After all preparations are completed, the CNC system 9 issues a start command to move the milling mechanism 2 and begin milling the workpiece to process the spiral groove. At this time, the center support 5 does not run. S2: When the milling mechanism 2 moves to the upper limit of the support setting, the center frame 5 is moved, and the time relay is activated at the same time; S3: The CNC system 9 calculates the distance between the milling mechanism 2 and the center frame 5 by measuring the moving speed and moving time of the milling mechanism 2. Based on the parameters of the milling mechanism's drive screw mechanism and the gear and rack of the servo translation motor, it activates the electronic gear ratio conversion model to convert the gear-to-rack driving speed into the linear moving speed of the milling mechanism's lead screw. It sets the relative position difference between the center frame 5 and the milling mechanism 2 as the chasing moving distance, controls the driver of the center frame's servo translation motor to execute the position closed loop, calculates the acceleration of the center frame, and makes the center frame accelerate to chase the milling mechanism 2, complete the displacement of the specified distance, and reach the specified position. S4: After the center frame 5 catches up to the designated position, the electronic gear ratio conversion model is activated to switch the moving speed of the center frame 5 to the same moving speed as the milling mechanism 2, so that the center frame 5 and the milling mechanism 2 move synchronously. S5: After the center frame 5 reaches the designated position and moves synchronously with the milling mechanism 2, the CNC system 9 issues a command to start the center frame cylinder to clamp the workpiece; S6: Within the time set by the time relay, check the center frame clamping signal. If there is no clamping signal, issue an alarm message, stop the machine tool, and stop for inspection and maintenance. If there is a clamping signal, the milling mechanism continues to mill the workpiece. S7: During the milling process, the synchronous movement of the center frame 5 and the milling mechanism 2 is set with a distance following error threshold for the center frame 5 to the milling mechanism 2. The CNC system 9 monitors the following error of the center frame 5 to the milling mechanism 2. When the following error exceeds the set threshold, the CNC system 9 automatically starts S3 to S6 to keep the distance between the center frame 5 and the milling mechanism 2 within the set distance range, thereby maintaining the synchronous movement of the center frame 5 and the milling mechanism 2. When the following error is within the set range, the milling mechanism continues to mill the workpiece until the set processing task is completed.

[0044] It should be further explained that, in order to ensure that the workpiece is supported by the center frame 5 when the milling mechanism 2 starts working, a center frame can be added in front of the milling mechanism in the direction of movement, forming a structure with a center frame supporting the milling mechanism both in front of and behind it along the direction of movement. Figure 14This is a flowchart illustrating how a CNC system controls a center rest positioned behind the milling mechanism to move synchronously with it in the direction of movement. Specifically, it's a flowchart of controlling the milling mechanism to maintain synchronous movement with the center rest supporting the machined portion of the workpiece. For the center rest positioned in front of the milling mechanism, supporting the unmachined portion of the workpiece, during machine operation, the CNC system first moves the center rest in front of the milling mechanism to a designated position. This movement is synchronized with the movement of the milling mechanism 2 when it begins milling the workpiece. The moving speed is set using an electronic gear ratio conversion model, based on the parameters of the milling mechanism's drive screw mechanism and the gears and racks of the servo translation motor. This converts the gear-to-rack drive speed into the linear movement speed driven by the milling mechanism's lead screw, ensuring the center rest maintains the same moving speed as the milling mechanism 2, achieving synchronous movement. The center rest stops supporting the workpiece and retracts before reaching the milling endpoint, ensuring the milling mechanism can complete the full length milling of the workpiece. The center rest behind the milling mechanism continues to move synchronously. Figure 14 The process moves synchronously with the milling mechanism to effectively support the workpiece. With the support of the two center frames at the front and rear of the milling mechanism, the workpiece is better supported and vibration is prevented during the machining process, which is more conducive to the precise machining of spiral grooves and the improvement of workpiece machining quality. It is especially suitable for machining slender workpieces. Example 3

[0045] like Figure 8-9 As shown, a CNC milling machine tool includes a machine tool worktable 1, a milling mechanism 2 movably mounted in the middle of the machine tool worktable 1, a spindle housing 3 fixedly mounted on one end of the upper part of the machine tool worktable 1, an automatic tool changing mechanism 4 fixedly mounted on the top of the spindle housing 3, a center frame 5 mounted on the upper part of the machine tool worktable 1 to cooperate with the milling mechanism 2 to support the workpiece, a tailstock 6 movably mounted on the other end of the upper part of the machine tool worktable 1 near the milling mechanism 2, a fixed protective shell 7 fixedly mounted on the machine tool worktable 1 to prevent chip splashing, a double electric door 8 installed in cooperation with the fixed protective shell 7, and a CNC system 9 installed on the double electric door 8. The CNC system 9 is connected to the milling mechanism 2, the spindle housing 3, the center frame 5, the double electric door 8 and the tailstock 6 respectively.

[0046] The machine tool worktable 1 includes an inclined worktable body 11, a chip collection groove 12 with a chip discharge port that is bolted to the front end of the worktable body 11, an automatic chip conveyor 13 that is embedded in the lower end of the worktable body 11 and connected to the CNC system 9 and works with the chip collection groove 12 to clean chips, a first mounting groove 14 opened at the upper end of the worktable body 11, milling mechanism linear guide rails 15 that are bolted to both sides of the first mounting groove 14, a milling mechanism drive screw mechanism 16 that is installed inside the first mounting groove 14 and is used to drive the displacement of the milling mechanism 2, a second mounting groove 17 with a chip discharge port opened at the lower end of the worktable body 11, a tailstock drive screw mechanism 18 that is installed inside the second mounting groove 17 and is used to drive the displacement of the tailstock 6, and an inclined support seat 19 located at one end of the second mounting groove 17 and used to fix and install the spindle box 3.

[0047] The fixed protective shell 7 includes a back baffle 71 that is fixedly installed to the machine tool worktable 1 by bolts, and side baffles 72 that are fixedly installed to the machine tool worktable 1 and located on both sides of the back baffle 71 by bolts. Specifically, the double electric door 8 is assembled on the outside of the side baffles 72 to facilitate the opening and closing of the double electric door 8.

[0048] In this embodiment, the worktable body 11 is inclined, and the chips generated by milling can naturally slide into the chip collection groove 12 at the front end under the action of gravity, thereby improving chip removal efficiency.

[0049] like Figure 4 As shown, the milling mechanism 2 includes a large milling slide 21, a middle milling slide 22 mounted on the large milling slide 21, a middle slide drive screw mechanism 23 mounted on the upper middle part of the large milling slide 21 for driving the middle milling slide 22 to move, a C-axis rotation mechanism 24 mounted on the middle milling slide 22 via a round shaft, a C-shaped rack 25 detachably mounted on the lower end of the C-axis rotation mechanism 24, a steering drive motor 26 fixedly mounted on the middle milling slide 22, equipped with gears and meshing with the C-shaped rack 25, a vertical slide 27 assembled on the inner side of the upper end of the C-axis rotation mechanism 24, a tool holder 28 fixedly mounted on the vertical slide 27 and equipped with a tool, and a vertical screw drive motor 29 mounted on the outer side of the upper end of the C-axis rotation mechanism 24.

[0050] Specifically, the steering drive motor 26 has a built-in reduction mechanism, and a gear is installed at the front end of the reduction mechanism. Through the meshing of the gear with the C-shaped rack 25, it can drive the C-direction rotation mechanism 24 to work stably. The angle can be set and adjusted according to process requirements.

[0051] The lower end of the milling slide 21 is fixed with a milling mechanism guide slider 211 by bolts, and the upper end of the milling slide 21 is fixed with a milling slide guide rail 212 by bolts.

[0052] The inner side of the C-axis rotating mechanism 24 is fixedly installed with two parallel vertical guide rails 241 by bolts, and a vertical lead screw 242 for driving the vertical slide plate 27 is installed between the two vertical guide rails 241. The vertical lead screw 242 is connected to the vertical lead screw drive motor 29 by a belt, and the vertical lead screw 242 can be driven by the vertical lead screw drive motor 29 to drive the vertical slide plate 27 to adjust its vertical displacement.

[0053] It should be further explained that the large milling slide 21 drives the milling mechanism 2 to move along the length of the bed, i.e., the Z direction, while the middle milling slide 22 drives the tool holder 28 to move along the front-back direction, i.e., the X direction. The C-axis rotation mechanism 24 is installed on the middle milling slide 22 and drives the tool holder 28 to rotate at any angle in a direction perpendicular to the plane of the middle milling slide 22. The vertical slide 27 is installed at the bottom of the C-axis rotation mechanism 24 and drives the tool holder 28 to move up and down, i.e., move in the Y direction.

[0054] The milling mechanism guide slider 211 is assembled with the milling mechanism linear guide rails 15 on both sides of the first mounting groove 14. It plays a guiding role when the milling mechanism drive screw mechanism 16 drives the milling mechanism 2 to move, and enables the milling mechanism 2 to move smoothly and accurately. At the same time, the milling middle slide guide rail 212 facilitates the middle slide drive screw mechanism 23 to drive the milling middle slide 22 to move smoothly and accurately. The vertical screw drive motor 29 drives the vertical screw 242 to drive the vertical slide 27 to make precise up and down displacement adjustments, so that the tool holder 28 can accurately contact the tool with the workpiece. This not only improves the milling accuracy of the workpiece, but also improves the surface finish of the milled surface of the workpiece. At the same time, it can also adjust and process workpieces with any groove shape.

[0055] like Figure 10-13 As shown, the center frame 5 includes a center frame slide 51, a workpiece support seat 52 movably mounted on the upper end of the center frame slide 51, a workpiece chuck 53 embedded in the upper end of the workpiece support seat 52 with its mounting opening facing the spindle centerline of the spindle housing 3, a cylinder 54 fixedly mounted above one end of the center frame slide 51 with its output end fixedly mounted to the workpiece support seat 52, a servo translation motor 55 with a drive gear mounted on one side of the upper end of the center frame slide 51, a rack 56 mounted on the machine tool worktable 1 and cooperating with the servo translation motor 55, a scraper bar 57 fixedly mounted on one side of the lower end of the center frame slide 51 by bolts, scrapers 58 symmetrically welded to the bottom of the center frame slide 51, and a workpiece quality inspection device 59 mounted on the center frame slide 51.

[0056] Specifically, the servo translation motor 55 has a built-in reduction mechanism and is equipped with a drive gear, which can cooperate with the rack and pinion 56 to drive the center frame 5 to move and work stably.

[0057] The upper end of the center frame slide plate 51 is fixedly mounted with a support seat guide slide rail 511 by bolts, and the lower end of the workpiece support seat 52 is fixedly mounted with a support seat guide slider 521 that cooperates with the support seat guide slide rail 511 by bolts.

[0058] The workpiece quality inspection device 59 includes a base 591 fixedly installed with the central frame slide 51, a multi-degree-of-freedom robotic arm 592 mounted on the base 591, and an arc-shaped inspection strip 593 mounted on the multi-degree-of-freedom robotic arm 592 for approaching the workpiece.

[0059] The arc-shaped detection strip 593 includes an arc-shaped strip body 5931, an arc-shaped groove 5932 formed inside the arc-shaped strip body 5931, and a laser interferometer 5933, a camera 5934 and an ultrasonic probe 5935 that are sequentially fixed inside the arc-shaped groove 5932.

[0060] The multi-degree-of-freedom robotic arm 592 can flexibly adjust the position and orientation of the arc-shaped detection strip 593, and can perform motion detection around the workpiece surface. At the same time, the CNC system is set with a motion compensation program according to the movement of the multi-degree-of-freedom robotic arm 592 to ensure the smooth operation of the multi-degree-of-freedom robotic arm 592, and ensure the smooth operation of the laser interferometer 5933, camera 5934, and ultrasonic probe 5935. The laser interferometer 5933 uses the principle of light wave interference to analyze the surface morphology of the workpiece through interference fringes, and then feeds back to the CNC system 9 to judge the surface roughness of the workpiece. The high-resolution camera 5934 acquires images of the workpiece surface, and combines them with the image processing algorithm in the CNC system 9 to analyze the quality of the grooving part of the workpiece, such as the size of the grooving. The ultrasonic probe 5935 emits high-frequency ultrasonic waves into the workpiece. When it encounters a crack, it will be reflected. By analyzing the time, amplitude, and shape of the echo, the location, depth, and size of the crack are determined, thereby detecting the quality of the workpiece grooving process online and ensuring that the workpiece is a good finished product when it leaves the production line.

[0061] In this embodiment, a clear image of the workpiece is captured at a specific angle using a high-resolution camera 5934. After calibration (determining the actual size represented by each pixel), an image processing algorithm is used to automatically identify the pixel positions of the two sides of the workpiece groove edge in the image. The actual width, depth, curvature, and other dimensions are obtained by converting the pixel distance.

[0062] In this embodiment, the ultrasonic probe 5935 is an air-coupled ultrasonic probe. Compressed gas is used to periodically blow and clean the ultrasonic probe 5935, the laser interferometer 5933, and the camera 5934 to ensure their normal operation.

[0063] Combined with appendix Figure 8-11The cylinder 54 can smoothly drive the workpiece support 52 to move and adjust by the cooperation of the support base guide slide rail 511 and the support base guide slider 521, so that the workpiece chuck 53 supports the workpiece and changes the lifting position according to the machining groove shape, preventing the workpiece from bending and deforming due to excessive length, as well as excessive vibration and torque, which would prevent the milling mechanism 2 from being unable to mill accurately.

[0064] Furthermore, the milling mechanism 2 is controlled by the CNC system 9 to drive the lead screw mechanism 16 to smoothly mill the workpiece. The center support 5 is controlled by the CNC system 9 to move through the drive gear of the servo translation motor 55 in conjunction with the rack 56. This avoids the center support 5 obstructing the translation of the milling mechanism 2. When processing ultra-long workpieces, the CNC system can also control the center support 5 and the milling mechanism 2 to move synchronously, ensuring that the milling part of the workpiece is supported synchronously, preventing workpiece vibration, and further improving machining accuracy and milling surface finish. The method of controlling the synchronous movement of the milling mechanism 2 and the center support 5 by the CNC system is the same as in Embodiment 2. The difference is that if a structure with two center supports at the front and rear of the milling mechanism is adopted, the center support at the front of the milling mechanism does not need to be equipped with the workpiece quality detection device 59. The other structures are the same as the structure of the center support at the rear of the milling mechanism.

[0065] When machining cross-sections that are rhomboid or irregular, CNC milling machines need to adjust the tools mounted on the tool holder 28 to the required tool size. In addition, the tool holder 28 needs to be moved along the X-direction to any position required by the process by adjusting the milling slide 22 to ensure accurate machining of the groove shape. The components of the center frame 5 are also adjusted accordingly and precisely controlled by the CNC system to meet the machining requirements of various spiral grooves.

[0066] When the CNC milling machine is working, because the chip collection groove 12 is flat-bottomed, the chips roll into the chip collection groove 12 and cannot fall into the automatic chip conveyor 13 for automatic discharge. Therefore, the scraper rod 57 extends into the chip collection groove 12. When the servo translation motor 55 moves in conjunction with the rack 56, the scraper rod 57 can scrape the chips accumulated in the chip collection groove 12 into the automatic chip conveyor 13 for automatic discharge. The second mounting groove 17 is the part where the most chips accumulate during the milling process. In order to ensure the stable operation of the center frame 5 and the tail frame 6 and the machining accuracy of the workpiece, the scraper 58 scrapes the chips by moving left and right during the movement of the center frame 5. This pushes the chips to both sides, so that the chips fall into the automatic chip conveyor 13 through the chip outlet of the second mounting groove 17 for automatic discharge.

[0067] With the cooperation of the spindle box 3 and the tailstock 6, and the support of the center frame 5, the machine tool can also process workpieces of different diameters and lengths, making the machine tool more widely applicable.

[0068] The above embodiments of the present invention are not intended to limit the scope of protection of the present invention. The implementation of the present invention is not limited thereto. All other modifications, substitutions or alterations made to the above structure of the present invention based on the above content of the present invention, in accordance with ordinary technical knowledge and common practice in the field, without departing from the basic technical idea of ​​the present invention, shall fall within the scope of protection of the present invention.

Claims

1. A CNC milling machine tool, characterized in that, The machine tool includes a machine tool worktable, a milling mechanism movably mounted in the middle of the machine tool worktable, a spindle box fixedly mounted on one end of the machine tool worktable, an automatic tool changing mechanism fixedly mounted on the top of the spindle box, a center support mounted on the machine tool worktable to support the workpiece in conjunction with the milling mechanism, a tailstock movably mounted on the other end of the machine tool worktable near the milling mechanism, a fixed protective shell fixedly mounted on the machine tool worktable to prevent chip splashing, a double electric door installed in conjunction with the fixed protective shell, and a CNC system mounted on the double electric door. The CNC system is connected to the milling mechanism, the spindle box, the center support, the double electric door, and the tailstock respectively. The center frame and the milling mechanism are located on both sides of the spindle centerline of the spindle housing. The center frame includes a center frame slide, a workpiece support seat movably mounted on the upper part of the center frame slide, and a workpiece chuck embedded in the upper part of the workpiece support seat with its clamping opening facing the spindle centerline of the spindle housing. A cylinder is fixedly mounted on one end of the center frame slide and its output end is fixedly mounted to the workpiece support seat. A support seat guide rail is fixedly mounted on the upper end of the center frame slide by bolts, and a support seat guide slider that cooperates with the support seat guide rail is fixedly mounted on the lower end of the workpiece support seat by bolts. The workpiece chuck includes a chuck double-headed cylinder embedded in the upper end of the workpiece support, a chuck hook hinged to the output end of the chuck double-headed cylinder, a chuck hook rolling element installed at the end of the chuck hook, a front push cylinder embedded in the middle part of the chuck double-headed cylinder, and a front push rolling element installed at the output end of the front push cylinder. The center frame also includes a servo translation motor with a built-in reduction mechanism and gears mounted on the upper side of the center frame slide, and a spur rack mounted on the machine tool worktable and meshing with the gears of the servo translation motor. The center frame also includes a scraper rod fixedly installed on one side of the lower end of the center frame slide by bolts, scrapers symmetrically welded to the bottom of the center frame slide, and a workpiece quality inspection device installed on the center frame slide. The workpiece quality inspection device includes a base fixedly installed with the central frame slide, a multi-degree-of-freedom robotic arm mounted on the base, and an arc-shaped inspection strip mounted on the multi-degree-of-freedom robotic arm for approaching the workpiece. The arc-shaped detection strip includes an arc-shaped strip body, an arc-shaped groove formed inside the arc-shaped strip body, and a laser interferometer, a camera, and an ultrasonic probe that are sequentially fixed inside the arc-shaped groove; the ultrasonic probe is an air-coupled ultrasonic probe. Two center frames are provided, and the two center frames are respectively located in front of and behind the milling mechanism along the moving direction of the milling mechanism; When the milling mechanism is milling a workpiece, the CNC system calculates and controls the moving speed and distance of the center frame by the moving speed of the milling mechanism and the distance between the center frame and the milling mechanism, so that the center frame and the milling mechanism move synchronously.

2. The CNC milling machine tool according to claim 1, characterized in that, The machine tool worktable includes a worktable body, a chip collection groove with a chip discharge port that is bolted to the front end of the worktable body, an automatic chip conveyor that is embedded in the lower end of the worktable body and connected to the CNC system and works with the chip collection groove to clean chips, a first mounting groove on the upper end of the worktable body, milling mechanism linear guides that are bolted to both sides of the first mounting groove, a milling mechanism drive screw mechanism that is installed inside the first mounting groove for driving the displacement of the milling mechanism, a second mounting groove on the lower end of the worktable body with a chip discharge port, a tailstock drive screw mechanism that is installed inside the second mounting groove for driving the displacement of the tailstock, and an inclined support seat located at one end of the second mounting groove for fixing the spindle box; the worktable body is inclined.

3. The CNC milling machine tool according to claim 1, characterized in that, The fixed protective shell includes a back panel fixedly installed to the machine tool worktable, and side guards located on both sides of the back panel and fixedly installed to the machine tool worktable by bolts; the double electric door is assembled on the outside of the side guards.

4. A CNC milling machine tool according to claim 1, characterized in that, The milling mechanism includes a large milling slide, a middle milling slide mounted on the large milling slide, a middle slide drive screw mechanism mounted in the middle of the upper part of the large milling slide for driving the middle milling slide to move, a C-axis rotation mechanism mounted on the upper part of the middle milling slide via a round shaft, a C-shaped rack detachably mounted on the lower end of the C-axis rotation mechanism, a steering drive motor fixedly mounted on the upper part of the middle milling slide, equipped with gears and meshing with the C-shaped rack, a vertical slide mounted on the inner side of the upper end of the C-axis rotation mechanism, a tool holder fixedly mounted on the vertical slide and equipped with a tool, and a vertical screw drive motor mounted on the outer side of the upper end of the C-axis rotation mechanism.

5. A CNC milling machine tool according to claim 4, characterized in that, The steering drive motor has a built-in reduction mechanism, with a gear installed at the front end of the reduction mechanism and meshing with a C-shaped rack. The lower end of the large milling slide is fixed with a milling mechanism guide slider by bolts, and the upper end of the large milling slide is fixed with a milling middle slide guide rail by bolts. The inner side of the C-axis rotating mechanism is fixed with two parallel vertical guide rails by bolts, and a vertical lead screw that drives the vertical slide plate to move is installed between the two vertical guide rails. The vertical lead screw and the vertical lead screw drive motor are connected by a belt. The milling mechanism guide slider is assembled with the milling mechanism linear guide rails on both sides of the first mounting groove.

6. A CNC milling machine tool according to claim 1, characterized in that, The claw-shaped rolling element and the front-mounted rolling element are either balls or rollers.

7. A CNC milling machine tool according to claim 1, characterized in that, The servo translation motor is connected to the CNC system and is used to drive the center frame slide to move along the machine tool table.

8. A CNC milling machine tool according to claim 2, characterized in that, The scraper bar extends into the chip collection groove.

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