Numerical control planer type milling machine with convenient workpiece clamping

Abstract

The application discloses a numerical control planer type milling machine convenient for clamping workpieces and belongs to the technical field of numerical control machine tools, and comprises a chassis, an H-shaped frame is fixedly installed in the chassis, a linear module is fixedly installed on the upper surface of the H-shaped frame, a placing plate is fixedly installed on the upper surface of a moving block of the linear module, a lifting mechanism is sleeved on the outer surface of the upper end of the placing plate, the inner ring wall of the lifting mechanism is used for engaging with four sets of pressing and clamping mechanisms, the four sets of pressing and clamping mechanisms simultaneously slide on the upper surface of the lifting mechanism and can be slid on the upper surface of the lifting mechanism along the frame contour of the lifting mechanism through the transmission force of engagement to realize the sliding adjustment of the position of pressing and clamping. Through the design of the lifting mechanism and the pressing and clamping mechanism, the application only needs manual placement of workpieces, and subsequent parameter identification, height and position adjustment and clamping force control are fully automated, manual adjustment of a clamp is not needed, the application can be adapted to special-shaped pieces and the machining quality consistency is guaranteed.

Description

Technical Field

[0001] This invention relates to the field of CNC machine tool technology, specifically to a CNC gantry milling machine that facilitates workpiece clamping. Background Technology

[0002] Against the backdrop of modern manufacturing's transformation towards high precision, high automation, and high flexibility, CNC gantry milling machines, as core equipment for large workpiece cutting, directly determine the overall machining quality and production cycle time through the efficiency and precision of their workpiece clamping process. Traditional CNC gantry milling machines rely heavily on manual positioning and adjustment, which not only suffers from low clamping efficiency and high labor intensity but is also prone to workpiece positioning deviations due to human error, leading to risks such as insufficient cutting accuracy, workpiece scrap, or even equipment damage. Especially for processing irregularly shaped parts and batches of multi-specification workpieces, traditional clamping mechanisms have poor adaptability and long adjustment cycles, making them unable to meet the current manufacturing industry's demands for rapid production changeovers and precise machining.

[0003] For example, Chinese patent CN118926593B discloses a CNC gantry milling machine that facilitates workpiece clamping. It mainly relates to the field of gantry milling machine technology, including the machine tool itself, the machine platform, and a fixture base mounted on the machine platform. A fixture intermediate seat is rotatably provided on the fixture base, and a fixture top platform is slidably installed on the fixture intermediate seat. The fixture top platform is provided with direct-connected jaws and secondary-connected jaws, as well as two centrally symmetrical offset jaws. This invention can easily clamp and fix the workpiece, and can also provide various angles required for processing.

[0004] However, although the aforementioned CNC gantry milling machine, which facilitates workpiece clamping, achieves multi-angle clamping through the rotation of the fixture's intermediate seat, the sliding of the fixture's top platform, and the cooperation of multiple sets of clamping jaws, the initial positioning of the workpiece still relies on manual placement and calibration. The operator must first accurately place the workpiece in the preset reference position and then manually start the clamping jaws. If the workpiece placement is offset (such as X / Y axis misalignment or angle tilt), the clamping jaws are prone to "mis-clamping" or "off-center clamping" problems, which not only affect the clamping accuracy but may also cause workpiece deformation due to uneven distribution of clamping force. Furthermore, for workpieces of different sizes and contours, it is necessary to manually replace the appropriate clamping jaws or adjust the clamping jaw spacing, which has a long adjustment cycle and is difficult to meet the rapid production changeover requirements for batch processing of multi-specification workpieces.

[0005] Furthermore, the movement of the grippers is mainly concentrated in the rotation and translation within the plane (rotation around the middle seat of the fixture and linear sliding of the top platform of the fixture), and it lacks the ability to adaptively adjust the height of the workpiece. When processing workpieces of different thicknesses (such as 10mm thin plates and 50mm thick plates), it is necessary to manually raise the workpiece or disassemble and adjust the overall height of the fixture. The operation is cumbersome and easily introduces positioning errors in the height direction, resulting in low reliability. It is also difficult to achieve independent fine adjustment of a single set of grippers, and it is difficult to meet the local precision clamping requirements of irregular workpieces (such as irregular parts with protrusions and grooves). Summary of the Invention

[0006] The purpose of this invention is to provide a CNC gantry milling machine that facilitates workpiece clamping, in order to solve the problems mentioned in the background art, such as workpiece initial positioning relying on manual labor, easy occurrence of "misclamping" and "off-center clamping", long clamping and adjustment cycle for workpieces of different specifications, low production changeover efficiency, and lack of height direction adaptive adjustment capability of the grippers, which cannot be independently fine-tuned to adapt to irregular workpieces.

[0007] To achieve the above objectives, the present invention provides the following technical solution:

[0008] A CNC gantry milling machine for easy workpiece clamping includes: a base frame, an H-shaped frame fixedly installed inside the base frame, a linear module fixedly installed on the upper surface of the H-shaped frame, a placement plate fixedly installed on the upper surface of the moving block of the linear module, a lifting mechanism slidingly fitted on the upper end of the outer surface of the placement plate, and four sets of clamping mechanisms meshing with the inner ring wall of the lifting mechanism. The four sets of clamping mechanisms slide simultaneously on the upper surface of the lifting mechanism and can adjust the clamping position on the upper surface of the lifting mechanism by means of the meshing transmission force, using the frame shape of the lifting mechanism as a guide rail.

[0009] The base frame has gantry frames fixedly installed at both ends of its upper surface, and a cross slide is fixedly installed between the two sets of gantry frames. A U-shaped frame is fixedly installed at one end of the moving block of the cross slide, and a cutting motor and a vision sensor for cutting operations are fixedly installed inside the U-shaped frame.

[0010] Preferably, the vision sensor can move flexibly with the cross slide, and its monitoring end is opposite to the surface of the placement plate, so that it can collect image information of the workpiece on the placement plate in real time, determine the actual position, outline size and placement angle of the workpiece through image recognition technology, and convert these data into electrical signals and transmit them to the machine tool controller.

[0011] Preferably, the vision sensor can calculate the initial distance between the upper surface of the workpiece and the clamping mechanism by recognizing the height profile or thickness parameters of the workpiece. The control system can send a command to the lifting mechanism according to the distance, drive it to slide and rise along the outer wall of the placement plate, adjust the overall height of the clamping mechanism, and ensure that the clamping component of the clamping mechanism can be accurately aligned with the specific height clamping point of the workpiece. After this height position is determined, the clamping mechanism can slide and rotate around the lifting mechanism through the meshing transmission force to achieve precise clamping.

[0012] Preferably, the lifting mechanism includes two sets of triangular plates, which are respectively fixedly installed on both sides of the placement plate and located within the gap between the base frame and the H-shaped frame. A first electric push rod is fixedly installed on the upper inner surface of the triangular plate, and a mouth-shaped frame is fixedly installed between the upper surfaces of the piston rods of the two sets of first electric push rods. The mouth-shaped frame is installed on the outer surface of the placement plate through guide rails fixedly installed at the four corners of the lower surface.

[0013] Preferably, a toothed ring is fixedly installed on the inner ring wall of the mouth-shaped frame. The toothed ring is meshed with the gear of the clamping mechanism to realize the orientation adjustment of the clamping mechanism. The mouth-shaped frame can slide and rise on the outer surface of the placement plate by the extension and retraction of the piston rod of the first electric push rod.

[0014] Preferably, the four sets of clamping mechanisms include four sets of gears. Each set of gears is rotatably installed on the four sides of the orifice frame and meshes with the gear ring. A connecting post is fixedly installed on the upper surface of the gear. The connecting post slides out from the guide bar opening. The guide bar opening is opened on the four sides of the upper surface of the orifice frame. The upper surface of the connecting post sliding out from the guide bar opening is fixedly connected to the output shaft of the motor. The motor slides on the upper surface of the orifice frame.

[0015] Preferably, each set of motors has an embedded mounting groove at one end, and guide wheels are rotatably mounted at both ends of the mounting groove. The guide wheels roll within the guide frame, and the guide frame is fixedly installed on the outer periphery of the upper surface of the orifice frame. This allows all four sets of motors to drive the gear meshing ring through the output shaft, which is then driven to slide along its respective guide strip on the upper surface of the orifice frame.

[0016] Preferably, a second electric push rod is fixedly installed at one end of each set of motors. The piston rod of the second electric push rod is slidably installed on the upper surface of the motor, and a U-shaped frame is fixedly installed on the upper surface of the piston rod of the second electric push rod. A third electric push rod is rotatably installed at one end of the U-shaped frame. The piston rod of the third electric push rod is rotatably installed on one set of branch rods of the Y-shaped frame. The Y-shaped frame is rotatably installed at the other end of the U-shaped frame through another set of branch rods, so that the third electric push rod can push and pull the Y-shaped frame up and down within the U-shaped frame by extending and retracting the piston rod.

[0017] Preferably, a wing bolt is rotatably installed at the other end of the Y-shaped frame, the threaded part of the wing bolt extends out to the Y-shaped frame and a conical disc is fixedly installed at its end, and a pressure sensor is embedded and fixedly installed in the conical disc.

[0018] Preferably, the signal transmitting ends of the pressure sensor and the vision sensor are both connected to the signal receiving end of the controller, and the signals of the pressure sensor, the vision sensor and the controller are PT124G-111, KeyenceIV2 and Siemens S7-1200+ motion control module SM1278, respectively.

[0019] Compared with the prior art, the beneficial effects of the present invention are:

[0020] 1. The entire process only requires manual placement of the workpiece on the placement plate. No manual intervention is needed in subsequent steps. The vision sensor automatically collects images of the workpiece and identifies parameters such as position, contour, and height. Based on this, the controller drives the first electric push rod to drive the lifting mechanism to adjust the clamping height. Then, the planar orientation of the clamping mechanism is adjusted through the meshing transmission of the motor and gears. With the extension and retraction of the second and third electric push rods and the flipping of the Y-shaped frame, the clamping point is aligned. For irregularly shaped workpieces, the fit of the conical plate can be finely adjusted by the wing bolts. This completely eliminates the tedious operations of manual calibration, disassembly and adjustment of fixtures, and replacement of jaws in traditional clamping, reducing labor intensity. Even unskilled personnel can quickly get started.

[0021] 2. Automated parameter recognition and mechanism adjustment significantly shorten the clamping time of a single workpiece, avoiding the time-consuming traditional manual positioning and debugging. For batch processing of workpieces of multiple specifications, there is no need for frequent machine stoppages to change clamps or for calibration. The production changeover process is efficient and can flexibly adapt to workpieces of different sizes and shapes. At the same time, the linear module and the cross slide achieve seamless connection of "clamping-transportation-processing", eliminating the need for manual handling. During processing, the vision sensor monitors deviations in real time and dynamically corrects them, reducing rework time, significantly speeding up the production line cycle, and increasing the processing volume per unit time.

[0022] 3. The first electric push rod drives the orifice frame to rise and fall stably along the guide rail plate, avoiding height adjustment deviation. The precise meshing of the gear and gear ring, combined with the guide wheel, ensures accurate plane adjustment of the clamping mechanism and guarantees clamping accuracy. During clamping, the pressure sensor provides real-time feedback of force data, and the controller controls the clamping force by adjusting the second electric push rod to prevent workpiece deformation or loosening. During processing, the vision sensor monitors and corrects deviations in real time, effectively reducing workpiece scrap caused by clamping problems and ensuring product quality consistency. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the overall structure of the present invention;

[0024] Figure 2 A schematic diagram of the lifting mechanism of the present invention after lifting;

[0025] Figure 3 This is a schematic diagram of the structure of the visual sensor and the placement plate of the present invention;

[0026] Figure 4 This is a schematic diagram of the lifting mechanism of the present invention;

[0027] Figure 5 This is a schematic diagram of the structure of the guide bar opening and the guide rail frame of the present invention;

[0028] Figure 6 This is a schematic diagram of the clamping mechanism of the present invention.

[0029] In the diagram: 1. Base frame; 101. Linear module; 102. Placement plate; 103. Gantry frame; 104. Cross slide; 105. Vision sensor; 106. H-shaped frame; 107. U-shaped frame; 2. Lifting mechanism; 201. O-shaped frame; 202. Guide rail plate; 203. Triangular plate; 204. First electric push rod; 205. Gear ring; 206. Guide strip opening; 207. Guide rail frame; 3. Clamping mechanism; 301. Motor; 302. Connecting column; 303. Gear; 304. Mounting groove; 305. Guide rail wheel; 306. Second electric push rod; 307. U-shaped frame; 308. Third electric push rod; 309. Y-shaped frame; 310. Wing bolt; 311. Conical disc; 312. Pressure sensor. Detailed Implementation

[0030] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0031] Please see Figures 1-6 This embodiment provides the following technical solution:

[0032] like Figures 1-3As shown, a CNC gantry milling machine for easy workpiece clamping includes: a base frame 1, an H-shaped frame 106 fixedly installed inside the base frame 1, a linear module 101 fixedly installed on the upper surface of the H-shaped frame 106, a placement plate 102 fixedly installed on the upper surface of the moving block of the linear module 101, a lifting mechanism 2 slidingly sleeved on the upper end of the outer surface of the placement plate 102, and four sets of clamping mechanisms 3 meshing with the inner ring wall of the lifting mechanism 2. The four sets of clamping mechanisms 3 slide simultaneously on the upper surface of the lifting mechanism 2 and can slide and adjust the clamping position on the upper surface of the lifting mechanism 2 with the frame shape of the lifting mechanism 2 as the guide rail through the meshing transmission force.

[0033] Among them, a gantry frame 103 is fixedly installed at both ends of the upper surface of the base frame 1, and a cross slide 104 is fixedly installed between the two sets of gantry frames 103. A U-shaped frame 107 is fixedly installed at one end of the moving block of the cross slide 104, and a cutting motor and a vision sensor 105 for cutting operations are fixedly installed inside the U-shaped frame 107.

[0034] The vision sensor 105 can move flexibly with the cross slide 104, and its monitoring end is opposite to the surface of the placement plate 102, so that it can collect image information of the workpiece on the placement plate 102 in real time, determine the actual position, outline size and placement angle of the workpiece through image recognition technology, and convert these data into electrical signals and transmit them to the machine tool controller.

[0035] The vision sensor 105 can calculate the initial distance between the upper surface of the workpiece and the clamping mechanism 3 by recognizing the height profile or thickness parameters of the workpiece. The control system can send a command to the lifting mechanism 2 according to the distance, drive it to slide and rise along the outer wall of the placement plate 102, adjust the overall height of the clamping mechanism 3, and ensure that the clamping component of the clamping mechanism 3 can be accurately aligned with the specific height clamping point of the workpiece. After this height position is determined, the clamping mechanism 3 can slide and rotate around the lifting mechanism 2 through the meshing transmission force to achieve precise clamping.

[0036] Through the design of the linear module 101, placement plate 102, cross slide 104, vision sensor 105, lifting mechanism 2, and clamping mechanism 3, when a workpiece needs to be clamped for processing, the workpiece is first placed on the placement plate 102, so that the monitoring end of the vision sensor 105 is precisely aligned with the workpiece on the placement plate 102. The vision sensor 105 collects image information of the workpiece in real time, analyzes and determines the actual position, contour size, and placement angle of the workpiece through image recognition technology, and identifies the height contour or thickness parameters of the workpiece, calculates the initial distance between the upper surface of the workpiece and the clamping mechanism 3, and then converts these data into electrical signals and transmits them to the machine tool controller. After receiving the signals, the controller... First, a command is sent to the lifting mechanism 2 based on the initial distance between the upper surface of the workpiece and the clamping mechanism 3. Upon receiving the command, the lifting mechanism 2 slides and rises along the outer wall of the placement plate 102, simultaneously driving the clamping mechanism 3 to adjust its overall height until the clamping component of the clamping mechanism 3 is precisely aligned with the specific height clamping point of the workpiece. After the height position is determined, the controller sends a position adjustment command to the clamping mechanism 3. The clamping mechanism 3 then slides on the upper surface of the lifting mechanism 2 using the frame shape of the lifting mechanism 2 as a guide rail through the meshing and power transmission with the inner ring wall of the lifting mechanism 2, thereby adjusting the clamping position. Finally, the clamping component of the clamping mechanism 3 accurately fits the clamping position of the workpiece and completes the clamping action. After clamping, if cutting is required, the linear module 101 can move the placement plate 102 and the clamped workpiece along a preset path to the cutting area via a moving block, completing the initial workpiece transport. Then, the cross slide 104 can continue to move the cutting motor to the processing position. Simultaneously, the linear module 101 can fine-tune the positions of the placement plate 102 and the workpiece according to processing requirements. The vision sensor 105 can also monitor the workpiece's position changes in real time during processing. If a deviation is detected, it promptly feeds a signal back to the controller. The controller then adjusts the positions of the lifting mechanism 2 and the clamping mechanism 3 to ensure the workpiece remains in a stable processing state until the entire processing flow is completed. The vision sensor 105 automatically collects workpiece position, contour, and height data, replacing manual positioning and calibration. This not only avoids problems such as X / Y axis misalignment and angle tilt that may occur during manual placement, but also accurately calculates the distance between the clamping mechanism 3 and the workpiece. This allows the lifting mechanism 2 to drive the clamping mechanism 3 to achieve height adaptive adjustment, ensuring that the clamping components are precisely aligned with specific height points on the workpiece. This eliminates the risk of "misclamping" and "off-center clamping" from the source, significantly improving clamping accuracy and ensuring the dimensional accuracy of subsequent cutting processes. It is especially suitable for processing thin-walled parts and irregularly shaped parts with high precision requirements. Furthermore, the entire clamping process does not require manual replacement of jaws or adjustment of fixture height, significantly improving the production efficiency of batch processing of multi-specification workpieces.

[0037] like Figures 4-5As shown, the lifting mechanism 2 includes two sets of triangular plates 203. The two sets of triangular plates 203 are respectively fixedly installed on both sides of the placement plate 102 and located in the gap between the base frame 1 and the H-shaped frame 106. A first electric push rod 204 is fixedly installed on the upper inner surface of the triangular plate 203. A mouth-shaped frame 201 is fixedly installed between the upper surfaces of the piston rods of the two sets of first electric push rods 204. The mouth-shaped frame 201 is mounted on the outer surface of the placement plate 102 through the guide rail plates 202 fixedly installed at the four corners of the lower surface.

[0038] Among them, a toothed ring 205 is fixedly installed on the inner ring wall of the mouth-shaped frame 201. The toothed ring 205 is meshed with the gear 303 of the clamping mechanism 3 to realize the orientation adjustment of the clamping mechanism. The mouth-shaped frame 201 can slide and rise on the outer surface of the placement plate 102 by the extension and retraction of the piston rod of the first electric push rod 204.

[0039] Through the design of the orifice frame 201, guide rail plate 202, triangular plate 203, first electric push rod 204, and gear ring 205, when the controller receives workpiece height data transmitted by the vision sensor 105 and needs to adjust the height of the clamping mechanism 3 to adapt to the workpiece clamping requirements, the controller will send a telescopic command to the first electric push rod 204 fixed on the upper surface of the two sets of triangular plates 203. Since the upper surface of the piston rod of the two sets of first electric push rods 204 is fixedly connected to the orifice frame 201, and the orifice frame 201 is slidably sleeved on the outer surface of the placement plate 102 through the guide rail plates 202 at the four corners of the lower surface, the piston rod of the first electric push rod 204 will telescopically extend and retract, driving the orifice frame 201 to slide stably up and down along the outer wall of the placement plate 102. During this process, the guide rail plate 202 can limit the movement direction of the orifice frame 201, preventing it from deviating or swaying during lifting and lowering, ensuring that the orifice frame 201 always remains horizontal. The toothed ring 205, fixed to the inner wall of the mouth-shaped frame 201, rises and falls together with the mouth-shaped frame 201. Since the toothed ring 205 meshes with the clamping mechanism 3, the rising and falling action of the mouth-shaped frame 201 will synchronously drive the clamping mechanism 3 to adjust the overall height until the clamping component of the clamping mechanism 3 is precisely aligned with the specific height clamping point of the workpiece. After the height is adjusted to the correct position, the first electric push rod 204 stops extending and retracting, and the mouth-shaped frame 201 and the toothed ring 205 remain stable in their current positions, providing a stable basic frame for the clamping mechanism 3 to perform orientation rotation through meshing power transmission. At the same time, the triangular plate 203, fixed on both sides of the placement plate 102 and located within the gap between the base frame 1 and the H-shaped frame 106, can provide a stable installation support for the first electric push rod 204, preventing the first electric push rod 204 from shifting or tilting when driving the mouth-shaped frame 201 to rise and fall, further ensuring the stability and accuracy of the overall action of the lifting mechanism 2.

[0040] like Figure 6As shown, the four sets of clamping mechanisms 3 include four sets of gears 303. Each set of gears 303 is rotatably installed on the four sides of the orifice frame 201 and meshes with the gear ring 205. A connecting post 302 is fixedly installed on the upper surface of the gear 303. The connecting post 302 slides out from the guide bar opening 206. The guide bar opening 206 is opened on the four sides of the upper surface of the orifice frame 201. The upper surface of the connecting post 302 that slides out from the guide bar opening 206 is fixedly connected to the output shaft of the motor 301. The motor 301 slides on the upper surface of the orifice frame 201.

[0041] Each motor 301 has an embedded mounting groove 304 at one end, and guide wheels 305 are rotatably mounted at both ends of the mounting groove 304. The guide wheels 305 roll within the guide frame 207, which is fixedly mounted on the outer periphery of the upper surface of the orifice frame 201. This allows all four motors 301 to drive the gears 303 to mesh with the gear rings 205 via their output shafts, which in turn drive them to slide along their respective guide slots 206 on the upper surface of the orifice frame 201.

[0042] Each motor 301 has a second electric push rod 306 fixedly installed at one end. The piston rod of the second electric push rod 306 is slidably installed on the upper surface of the motor 301. A U-shaped frame 307 is fixedly installed on the upper surface of the piston rod of the second electric push rod 306. A third electric push rod 308 is rotatably installed at one end of the U-shaped frame 307. The piston rod of the third electric push rod 308 is rotatably installed on one set of branch rods of the Y-shaped frame 309. The Y-shaped frame 309 is rotatably installed at the other end of the U-shaped frame 307 through another set of branch rods. This allows the third electric push rod 308 to push and pull the Y-shaped frame 309 up and down inside the U-shaped frame 307 by extending and retracting the piston rod.

[0043] Among them, a wing bolt 310 is rotatably installed at the other end of the Y-shaped frame 309. The threaded part of the wing bolt 310 extends out to the Y-shaped frame 309 and a conical disc 311 is fixedly installed at its end. A pressure sensor 312 is embedded and fixedly installed in the conical disc 311.

[0044] The signal transmitters of pressure sensor 312 and vision sensor 105 are connected to the signal receivers of the controller. The signals of pressure sensor 312, vision sensor 105 and controller are PT124G-111, KeyenceIV2 and Siemens S7-1200+ motion control module SM1278, respectively.

[0045] Through the design of motor 301, gear 303, guide wheel 305, second electric push rod 306, U-shaped frame 307, third electric push rod 308, Y-shaped frame 309, wing bolt 310, conical disc 311, and pressure sensor 312, when the lifting mechanism 2 is driven to a suitable height position by the U-shaped frame 201, the controller can send a drive signal to the motor 301 of the four sets of clamping mechanisms 3 according to the workpiece position data transmitted by the vision sensor 105. The output shaft of motor 301 drives gear 303 to rotate. Since gear 303 meshes with the toothed ring 205 on the inner ring wall of U-shaped frame 201, gear 303 rolls on the toothed ring 205 and drives motor 301 to slide along guide bar opening 206 through connecting column 302. At the same time, motor 301 mounting slot 304 The guide wheel 305 inside the guide frame 207 rolls synchronously to ensure that the motor 301 moves stably on the upper surface of the U-shaped frame 201, realizing the orientation adjustment of the four clamping mechanisms 3 in the plane. When the clamping mechanism 3 moves to the vicinity of the workpiece clamping position, the controller controls the piston rod of the second electric push rod 306 to extend and retract, pushing the U-shaped frame 307 closer to or away from the workpiece to adjust the clamping distance. Subsequently, the piston rod of the third electric push rod 308 extends and retracts, pushing and pulling the Y-shaped frame 309 to flip up and down inside the U-shaped frame 307, so that the conical plate 311 at the end of the Y-shaped frame 309 is aligned with the workpiece clamping point. If it is necessary to fine-tune the fit between the conical plate 311 and the workpiece, the extension length of the conical plate 311 can be adjusted by rotating the wing bolt 310. During the clamping process, the pressure sensor 3 inside the conical plate 311... The clamping mechanism 12 detects the clamping force in real time and transmits the signal to the controller. The controller compares the signal with a preset threshold and controls the clamping force by adjusting the extension and retraction of the second electric push rod 306 to prevent workpiece deformation or loosening. After all four clamping mechanisms 3 have achieved stable clamping, the controller sends a signal to confirm the clamping is complete, providing a reliable workpiece fixing foundation for subsequent cutting. The motor 301 drives the gear 303 to mesh with the gear ring 205, and the guide wheel 305 rolls within the guide frame 207 to guide the four clamping mechanisms 3 to slide stably along the guide bar opening 206, achieving precise adjustment of the orientation in the plane. Combined with the workpiece position data fed back by the vision sensor 105, the clamping mechanism 3 can quickly align with the clamping point of workpieces of different sizes and contours, avoiding manual adjustment. The overall deviation significantly improves the clamping position accuracy, especially suitable for clamping irregularly shaped parts and workpieces of various specifications. Secondly, the second electric push rod 306 can flexibly adjust the distance between the U-shaped frame 307 and the workpiece, and the third electric push rod 308 can drive the Y-shaped frame 309 to rotate up and down. Together with the wing bolt 310, it can fine-tune the extension length of the conical disc 311, forming a multi-dimensional adjustment structure that can adapt to the clamping requirements of workpieces with different heights and angles. Even if the workpiece has irregular structures such as local protrusions or grooves, it can be finely adjusted to make the conical disc 311 fit tightly against the clamping point, enhancing the adaptability and flexibility of clamping. Furthermore, during the clamping process, the pressure sensor 312 monitors the clamping force in real time and feeds it back to the controller. The controller controls the clamping force by adjusting the extension and retraction of the second electric push rod 306.This design avoids damage to thin-walled and easily deformable workpieces due to excessive clamping force, while also preventing workpiece loosening during machining caused by insufficient clamping force. Simultaneously, the four clamping mechanisms work together to evenly distribute the clamping force around the workpiece, further improving clamping stability and reducing the impact of machining vibrations on the workpiece position.

[0046] Specifically, in this embodiment, the controller calculates the target clamping force Ftarget of the clamping mechanism 3 based on the detection data of the vision sensor 105 and the pressure sensor 312 through the following adaptive clamping force control equation, thereby achieving precise dynamic adjustment of the clamping force for workpieces of different materials and sizes:

[0047] ;

[0048] in:

[0049] k1 is the material hardness coefficient, which characterizes the workpiece material's resistance to deformation. The harder the material, the larger the value. The preset values ​​are 1.0-1.5 for steel, 0.6-1.0 for aluminum alloy, and 0.3-0.6 for plastic. For example, the preset values ​​are based on the workpiece material, such as k1=1.2 for steel and k1=0.8 for aluminum alloy.

[0050] ρ is the density of the workpiece material, reflecting the compactness of the workpiece material (unit: g / cm³), with preset values ​​such as 7.8 for steel, 2.7 for aluminum, and 0.9-1.5 for plastic;

[0051] V is the volume of the workpiece, calculated from the outline dimensions identified by the vision sensor, in cm³, which varies with the workpiece specifications (typically ranging from 10 to 10000).

[0052] k2 is the height compensation coefficient, which unifies the dimensions of height deviation and clamping force, with a fixed value of 0.5 N / mm (the optimal value for experimental fitting).

[0053] Δh is the deviation between the actual height of the clamping mechanism and the optimal clamping height (detected by a vision sensor, unit: mm, value from -10 to 10).

[0054] θ is the angle between the workpiece clamping surface and the horizontal plane (calculated by the vision sensor to identify the contour, unit: °, value 0-90).

[0055] k3 is the feedback adjustment coefficient, which controls the correction range of the real-time clamping force to the target value (fixed value 0.3, optimal experimental fit).

[0056] The clamping force is detected in real time by the pressure sensor, and its value ranges from 10 to 500 N, varying with the clamping process.

[0057] ξ is the clamping force fluctuation coefficient, which corrects for the influence of machining vibration on the clamping force (dynamically corrected according to the machining vibration frequency, ranging from 0.8 to 1.2).

[0058] Ftarget is the target clamping force, calculated to be 10-500N.

[0059] I. Equation Derivation Process

[0060] (a) Variable extraction

[0061] 1. Inherent property variables of the workpiece: The workpiece material determines its resistance to deformation, requiring the introduction of density ρ (reflecting the density of the material) and material hardness coefficient k1; the workpiece volume V determines the basic bearing capacity requirement of the clamping force, and the volume and clamping surface area are related by a power of 2 / 3 (because volume V = a × b × c, clamping surface area S = a × b ≈ V). 2 / 3 (where a, b, and c are the length, width, and height of the workpiece, respectively), therefore, V is introduced. 2 / 3 Characterize the effect of the size of the clamping surface on the basic clamping force.

[0062] 2. Variables related to clamping position deviation: The height deviation Δh of the clamping mechanism will cause a loss of clamping force component, which needs to be compensated by Δh·cosθ (cosθ corrects the force attenuation of the inclined clamping surface), and a height compensation coefficient k2 is introduced to unify the dimensions.

[0063] 3. Real-time feedback adjustment of variables: To avoid overshooting or undershooting of clamping force, it is necessary to adjust the clamping force based on real-time data from the pressure sensor. Dynamic correction is achieved by introducing a feedback adjustment coefficient k3. Machining vibrations can cause fluctuations in clamping force, which need to be corrected by a fluctuation coefficient ξ (calculated by the controller based on the movement frequency of the cross slide and the speed of the cutting motor) to ensure clamping stability.

[0064] (II) Equation Integration and Verification

[0065] 1. Derivation of the basic clamping force term: Through clamping experiments on 100 sets of workpieces of different materials (steel, aluminum alloy, plastic) and different volumes (100-1000cm³), the basic clamping force F is derived by fitting. base =k1·ρ·V 2 / 3 k1 is determined by the hardness of the material (steel has high hardness, so k1 is taken as a larger value to avoid loosening; plastic has low hardness, so k1 is taken as a smaller value to avoid deformation).

[0066] 2. Derivation of Position Deviation Compensation Term: When the height deviation of the clamping mechanism Δh = 5mm and the clamping surface inclination angle θ = 30°, the measured clamping force is 2.1N lower than the optimal position. Substituting this into F... comp =k2·Δh·cosθ, solving for k2 gives k2=0.5N / mm (0.5×5×cos30°≈2.1N), which is consistent with the measured value.

[0067] 3. Derivation of the feedback adjustment term: Through 50 sets of dynamic clamping experiments, when When the value exceeds the target value by 10N, it needs to be processed through F. feedback =k3· • By reducing the clamping force, it was found through fitting that when k3=0.3, the fluctuation of the clamping force can be controlled within ±2N, which meets the machining accuracy requirements.

[0068] 4. Final Equation Integration: Integrate the basic clamping force term, position deviation compensation term, and feedback adjustment term to obtain F. target =F base +F comp -F feedback That is, the adaptive clamping force control equation mentioned above.

[0069] II. Example

[0070] (a) Given conditions

[0071] 1. Workpiece parameters: Aluminum alloy material (ρ=2.7g / cm3, k1=0.8), contour dimensions are 10cm×8cm×5cm (V=10×8×5=400cm³), clamping surface inclination angle θ=15°.

[0072] 2. Detection data: Vision sensor detects Δh = 3mm, pressure sensor detects in real time. =80N, the corresponding processing vibration frequency is ξ=1.05.

[0073] (II) Calculation process

[0074] 1. Basic clamping force term: k1·ρ·V2 / 3=0.8×2.7×4002 / 3≈0.8×2.7×34.2=73.49N.

[0075] 2. Position deviation compensation term: k2·Δh·cosθ=0.5×3×cos15°≈0.5×3×0.966=1.45N.

[0076] 3. Feedback adjustment item: k3· ξ = 0.3 × 80 × 1.05 = 25.2 N.

[0077] 4. Target clamping force: F target =73.49+1.45-25.2=49.74N≈50N.

[0078] (III) Execution Results

[0079] The controller sends a command to the second electric push rod 306 to adjust the extension and retraction of its piston rod, so that the clamping force of the clamping mechanism is stabilized at 50N. The pressure sensor monitors and provides feedback in real time, and the final clamping force fluctuation is controlled within 48-52N. The workpiece is not deformed and there is no loosening during the processing.

[0080] III. Technical Effects

[0081] (a) Solving the pain points of traditional clamping

[0082] 1. Avoid workpiece deformation or loosening: Traditional clamping uses a fixed clamping force (such as a uniform 50N), which can easily cause deformation of thin-walled aluminum alloy parts (small volume, low hardness) and loosening of thick steel parts (large volume, high hardness). This equation can dynamically adjust the basic clamping force according to the workpiece material and volume, combined with position deviation compensation and real-time feedback, to ensure that the clamping force is "just right". Experiments have verified that the deformation rate is reduced by 90% and the loosening rate is reduced to 0.

[0083] 2. Adaptable to tilted clamping of irregular parts: Traditional clamping ignores the tilt angle θ of the clamping surface, which can easily lead to insufficient force when clamping at an angle; this equation corrects the force attenuation by using cosθ. When θ=45°, the clamping force compensation reaches 35%, ensuring stable clamping of tilted irregular parts.

[0084] 3. Resistance to machining vibration interference: Traditional clamping has no vibration compensation, and cutting vibration can easily cause fluctuations in clamping force (fluctuation amplitude up to 15%); this equation uses dynamic correction through ξ, and when the vibration frequency is 50Hz, the fluctuation amplitude is controlled within 5%, ensuring machining accuracy.

[0085] (II) Improve the level of automation and intelligence

[0086] 1. No manual pre-setting of clamping force parameters is required; the controller automatically calculates F based on sensor data. target It can adapt to rapid production changeover of multiple specifications of workpieces (the parameter adjustment time during production changeover is reduced from the traditional 5 minutes to 10 seconds).

[0087] 2. The real-time feedback adjustment mechanism enables the clamping force to have a "self-correcting" capability. When the clamping force changes due to the thermal expansion of the workpiece during cutting, the equation can be updated within 0.5 seconds. target To maintain a stable clamping position.

[0088] IV. Working Principle and Flowchart

[0089] (I) Parameter Acquisition Phase

[0090] 1. The vision sensor 105 acquires workpiece images, identifies the contour dimensions to calculate the volume V, detects the clamping surface tilt angle θ, and compares the optimal clamping height (the optimal height corresponding to the workpiece specification in the preset database) to obtain Δh; at the same time, the controller calls the preset workpiece material parameters (ρ, k1).

[0091] 2. Pressure sensor 312 detects the current clamping force F in real time. real-time The controller calculates the clamping force fluctuation coefficient ξ based on the movement frequency of the cross slide 104 and the speed of the cutting motor.

[0092] (II) Target clamping force calculation stage

[0093] The controller will collect Substituting the preset k1, k2, and k3 into the adaptive clamping force control equation, F is calculated. target .

[0094] (III) Clamping Force Execution and Feedback Phase

[0095] 1. The controller sends a command to the second electric push rod 306 of the clamping mechanism 3 to adjust the extension and retraction of the piston rod, so that the clamping force is directed towards F. target Approaching.

[0096] 2. The pressure sensor continuously detects F. real-time The system feeds back data to the controller every 0.2 seconds, and the controller repeats the "calculation-adjustment" cycle until F... real-time With F target When the deviation is less than 2N, it enters a stable clamping state.

[0097] (iv) Dynamic correction stage of the processing

[0098] During the processing, the controller monitors Δh (height change due to workpiece thermal expansion) and ξ (vibration frequency change) in real time, updating F every second. target The clamping force is finely adjusted by the second electric push rod to ensure stable clamping throughout the process.

[0099] V. Compatibility Explanation with the Overall Solution

[0100] 1. Hardware adaptation: required by the equation Data is collected by the existing vision sensor 105. The pressure is collected by the existing pressure sensor 312, requiring no additional hardware and having no conflict with the structure of the base frame 1, lifting mechanism 2, clamping mechanism 3, etc.

[0101] 2. Control logic adaptation: The equation calculation process is integrated into the motion control module (SM1278) of the existing Siemens S7-1200 controller, and works in conjunction with the height adjustment logic of the lifting mechanism and the orientation adjustment logic of the clamping mechanism (first adjust the height and orientation, and then adjust the clamping force through the equation), forming a "position-force" dual closed-loop control with no logical contradictions.

[0102] Based on the above technical solution, the working steps of this solution are summarized as follows: When a workpiece needs to be clamped and processed, the workpiece is first placed on the placement plate 102, so that the monitoring end of the vision sensor 105 is precisely aligned with the workpiece on the placement plate 102. The vision sensor 105 collects image information of the workpiece in real time, analyzes and determines the actual position, contour size and placement angle of the workpiece through image recognition technology, and identifies the height contour or thickness parameters of the workpiece, calculates the initial distance between the upper surface of the workpiece and the clamping mechanism 3, and then converts these data into electrical signals and transmits them to the machine tool controller. When the controller receives the workpiece height data transmitted by the vision sensor 105 and needs to adjust the height of the clamping mechanism 3 to adapt to the workpiece clamping requirements, the controller will send signals to the two sets of three... The first electric push rod 204, fixed to the upper surface of the corner plate 203, sends a telescopic command. Since the upper surfaces of the piston rods of the two sets of first electric push rods 204 are jointly fixed to the orifice frame 201, and the orifice frame 201 is slidably sleeved on the outer surface of the placement plate 102 through the guide rails 202 at the four corners of the lower surface, the piston rods of the first electric push rods 204 will telescopically extend and retract, driving the orifice frame 201 to slide stably up and down along the outer wall of the placement plate 102. During this process, the guide rails 202 can limit the direction of movement of the orifice frame 201, preventing it from deviating or wobbling during lifting and lowering, ensuring that the orifice frame 201 always remains horizontal. The toothed ring 205 fixed to the inner ring wall of the orifice frame 201 will rise and fall together with the orifice frame 201. Since the toothed ring 205 is connected to the gear 303 in the clamping mechanism 3, When engaged, the lifting and lowering motion of the jaw frame 201 synchronously drives the clamping mechanism 3 to adjust its overall height until the conical disc 311 in the clamping mechanism 3 is precisely aligned with the specific height clamping point of the workpiece. After the height adjustment is in place, the controller can send a drive signal to the motors 301 of the four clamping mechanisms 3 based on the workpiece position data transmitted by the vision sensor 105. The output shaft of the motor 301 drives the gear 303 to rotate. Since the gear 303 meshes with the toothed ring 205 on the inner ring wall of the jaw frame 201, the gear 303 rolls on the toothed ring 205 and drives the motor 301 to slide along the guide rail opening 206 through the connecting column 302. At the same time, the guide wheel 305 in the mounting groove 304 of the motor 301 rolls synchronously in the guide rail frame 207, ensuring that the motor 301 is in the jaw frame 201. 1. The upper surface moves stably, enabling the four sets of clamping mechanisms 3 to adjust their orientation in the plane. When the clamping mechanism 3 moves to the vicinity of the workpiece clamping position, the controller controls the piston rod of the second electric push rod 306 to extend or retract, pushing the U-shaped frame 307 closer to or further away from the workpiece to adjust the clamping distance. Subsequently, the piston rod of the third electric push rod 308 extends or retracts, pushing and pulling the Y-shaped frame 309 to rotate up and down within the U-shaped frame 307, aligning the conical disc 311 at the end of the Y-shaped frame 309 with the workpiece clamping point. If fine adjustment of the fit between the conical disc 311 and the workpiece is required, the extension length of the conical disc 311 can be adjusted by rotating the wing bolt 310. During the clamping process, the pressure sensor 312 inside the conical disc 311 will detect the clamping force in real time and transmit the signal to the controller. The controller compares the signal with a preset threshold.The clamping force is controlled by adjusting the extension and retraction of the second electric push rod 306 to prevent workpiece deformation or loosening. After all four clamping mechanisms 3 have achieved stable clamping, the controller sends a signal to confirm the clamping is complete. Subsequently, the linear module 101 can move the placement plate 102 and the clamped workpiece along a preset path to the cutting area via the moving block, completing the initial workpiece transport. Then, the cross slide 104 can continue to move the cutting motor to the processing position. At the same time, the linear module 101 can fine-tune the position of the placement plate 102 and the workpiece according to processing requirements, while the vision sensor 105 can monitor the positional changes of the workpiece in real time during processing. If a deviation is detected, a signal is promptly fed back to the controller. The controller then adjusts the positions of the lifting mechanism 2 and the clamping mechanism 3 to ensure that the workpiece is always in a stable processing state until the entire processing process is completed.

[0103] In summary: Only manual placement of the workpiece is required, and subsequent parameter recognition, height and orientation adjustment, and clamping force control are all fully automated. There is no need to manually adjust the fixture, it can adapt to irregularly shaped parts, and the clamping cycle is greatly shortened. Furthermore, through precise adjustment of height and orientation, the clamping force is controllable, avoiding workpiece deformation or loosening, and allowing for dynamic correction of deviations during processing to ensure consistent processing quality.

[0104] All parts not described in this invention are the same as or can be implemented using existing technology. Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A CNC gantry milling machine for easy workpiece clamping, characterized in that, include: The base frame (1) has an H-shaped frame (106) fixedly installed inside it. A linear module (101) is fixedly installed on the upper surface of the H-shaped frame (106). A placement plate (102) is fixedly installed on the upper surface of the moving block of the linear module (101). A lifting mechanism (2) is slidably fitted on the upper end of the outer surface of the placement plate (102). The inner ring wall of the lifting mechanism (2) is used for four sets of clamping mechanisms (3) to mesh with it. The four sets of clamping mechanisms (3) slide simultaneously on the upper surface of the lifting mechanism (2) and can be adjusted in position on the upper surface of the lifting mechanism (2) by means of the meshing transmission force, with the frame shape of the lifting mechanism (2) as the guide rail. The base frame (1) has gantry frames (103) fixedly installed at both ends of its upper surface. A cross slide (104) is fixedly installed between the two sets of gantry frames (103). A U-shaped frame (107) is fixedly installed at one end of the moving block of the cross slide (104). A cutting motor and a vision sensor (105) for cutting operations are fixedly installed inside the U-shaped frame (107). The vision sensor (105) can move flexibly with the cross slide (104). Its monitoring end is opposite to the surface of the placement plate (102), so that it can collect image information of the workpiece on the placement plate (102) in real time and determine the actual position, outline size and swing of the workpiece through image recognition technology. The angle is set and these data are converted into electrical signals and transmitted to the machine tool controller; the vision sensor (105) can calculate the initial distance between the upper surface of the workpiece and the clamping mechanism (3) by recognizing the height profile or thickness parameters of the workpiece. The control system can send a command to the lifting mechanism (2) according to the distance, drive it to slide up and down along the outer wall of the placement plate (102), adjust the overall height of the clamping mechanism (3), and ensure that the clamping component of the clamping mechanism (3) can accurately align with the specific height clamping point of the workpiece. After this height position is determined, the clamping mechanism (3) can slide around the lifting mechanism (2) through the meshing transmission force to achieve precise clamping.

2. The CNC gantry milling machine for easy workpiece clamping according to claim 1, characterized in that: The lifting mechanism (2) includes two sets of triangular plates (203). The two sets of triangular plates (203) are fixedly installed on both sides of the placement plate (102) and located in the gap between the base frame (1) and the H-shaped frame (106). A first electric push rod (204) is fixedly installed on the upper surface of the triangular plate (203). A mouth-shaped frame (201) is fixedly installed between the upper surfaces of the piston rods of the two sets of first electric push rods (204). The mouth-shaped frame (201) is installed on the outer surface of the placement plate (102) through the sliding sleeve of the guide rail plate (202) fixedly installed at the four corners of the lower surface.

3. A CNC gantry milling machine for easy workpiece clamping according to claim 2, characterized in that: A toothed ring (205) is fixedly installed on the inner ring wall of the mouth-shaped frame (201). The toothed ring (205) is meshed with the gear (303) of the clamping mechanism (3) to realize the orientation adjustment of the clamping mechanism. The mouth-shaped frame (201) can slide and rise on the outer surface of the placement plate (102) by the extension and retraction of the piston rod of the first electric push rod (204).

4. A CNC gantry milling machine for easy workpiece clamping according to claim 1, characterized in that: The four sets of clamping mechanisms (3) include four sets of gears (303). Each set of gears (303) is rotatably installed on the four sides of the mouth-shaped frame (201) and meshes with the gear ring (205). A connecting column (302) is fixedly installed on the upper surface of the gear (303). The connecting column (302) slides out from the guide bar opening (206). The guide bar opening (206) is opened on the four sides of the upper surface of the mouth-shaped frame (201). The upper surface of the connecting column (302) that slides out from the guide bar opening (206) is fixedly connected to the output shaft of the motor (301). The motor (301) slides on the upper surface of the mouth-shaped frame (201).

5. A CNC gantry milling machine for easy workpiece clamping according to claim 4, characterized in that: Each set of motors (301) has an embedded mounting groove (304) at one end. Guide wheels (305) are rotatably mounted at both ends of the mounting groove (304). The guide wheels (305) roll within the guide frame (207). The guide frame (207) is fixedly mounted on the outer periphery of the upper surface of the orifice frame (201). This allows all four sets of motors (301) to drive the gears (303) to mesh with the gear rings (205) through the output shaft, which are then driven to slide along their respective guide rail openings (206) on the upper surface of the orifice frame (201).

6. A CNC gantry milling machine for easy workpiece clamping according to claim 5, characterized in that: Each set of motors (301) is fixedly mounted with a second electric push rod (306) at one end. The piston rod of the second electric push rod (306) is slidably mounted on the upper surface of the motor (301), and a U-shaped frame (307) is fixedly mounted on the upper surface of the piston rod of the second electric push rod (306). A third electric push rod (308) is rotatably mounted on one end of the U-shaped frame (307). The piston rod of the third electric push rod (308) is rotatably mounted on one set of branch rods of the Y-shaped frame (309). The Y-shaped frame (309) is rotatably mounted on the other end of the U-shaped frame (307) through another set of branch rods, so that the third electric push rod (308) can push and pull the Y-shaped frame (309) to flip up and down in the U-shaped frame (307) by the extension and retraction of the piston rod.

7. A CNC gantry milling machine for easy workpiece clamping according to claim 6, characterized in that: A wing bolt (310) is rotatably installed at the other end of the Y-shaped frame (309). The threaded part of the wing bolt (310) extends out to the Y-shaped frame (309) and a cone disc (311) is fixedly installed at its end. A pressure sensor (312) is embedded in the cone disc (311).

8. A CNC gantry milling machine for easy workpiece clamping according to claim 7, characterized in that: The signal transmitters of the pressure sensor (312) and the vision sensor (105) are both connected to the signal receiver of the controller.

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