Five-axis linkage engraving and milling machine

Abstract

The application provides a five-axis linkage engraving and milling machine applied to the technical field of machine tool equipment, which comprises a base, a machine tool shell, a column, a Z-axis mechanism, a clamping mechanism, a tool magazine, an XY-axis mechanism, a workbench and a safety limiting mechanism; wherein the safety limiting mechanism is used for avoiding driving overload failure of the clamping mechanism, and the safety limiting mechanism is linked and matched with the clamping mechanism and the Z-axis mechanism; the safety limiting mechanism, the clamping mechanism and the Z-axis mechanism are linked and matched, through the synergistic effect of a triggering mechanism, a self-locking mechanism and a pneumatic brake, the self-locking and emergency braking can be triggered quickly when the clamping mechanism collides and is driven to be overloaded, so that the cutter, the main shaft, the Z-axis mechanism and the workpiece are prevented from being damaged, meanwhile, the Z-axis servo motor is provided with an automatic brake holding function, the safety protection reliability is further improved, and the defects that the safety protection of the existing equipment depends on software and the response is lagged are solved.

Description

Technical Field

[0001] This application relates to the field of machine tool equipment technology, and in particular to a five-axis linkage engraving and milling machine. Background Technology

[0002] A five-axis linkage milling and engraving machine is a precision CNC machine tool that integrates milling and engraving. With the advantage of multi-axis linkage, it can achieve efficient processing of complex curved surfaces and irregular structures, and is widely used in aerospace, mold manufacturing, precision parts processing and other fields.

[0003] With the continuous improvement of machining accuracy and automation requirements, existing five-axis linkage engraving and milling machines have gradually exposed many defects. More specifically, during the machining process, the clamping mechanism of existing five-axis linkage engraving and milling machines is prone to excessive machining load, tool collision with workpiece or fixture due to parameter errors. This can lead to loss of control of the Z-axis mechanism, tool breakage, spindle damage, and even workpiece scrapping and equipment failure, seriously affecting machining safety and product qualification rate.

[0004] Therefore, a five-axis linkage engraving and milling machine is proposed to solve the above problems. Summary of the Invention

[0005] The purpose of this application is to address the technical problem that existing five-axis linkage engraving and milling machines lack necessary safety devices for the Z-axis drive mechanism, which can easily lead to equipment damage due to parameter errors during tool feed. Compared to existing technologies, this application provides a five-axis linkage engraving and milling machine, comprising: Base; The machine tool housing, located on top of the base, is used for equipment protection; The column is fixed on the base and includes two sets of vertically and symmetrically arranged slide rails. A Z-axis lead screw is rotatably connected between the two sets of slide rails. The Z-axis lead screw is driven by a Z-axis servo motor. The Z-axis mechanism includes a lever arm that is slidably connected to a column in the vertical direction. One side of the lever arm is fixed with a slider that cooperates with a slide rail and a nut seat that cooperates with a Z-axis lead screw. A clamping mechanism, located on the other side of the lever arm, is used to clamp the cutting tool; A tool magazine, located on one side of the column, is used to provide tools for the clamping mechanism. The tool magazine is an automatic tool changer. The XY axis mechanism is fixed on the base and is used to drive the worktable to move in XY axis linkage. A worktable is fixed to the output end of the XY axis mechanism, and a clamp for holding the workpiece is fixed to the top of the worktable. A safety limit mechanism is used to prevent the clamping mechanism from experiencing a drive overload failure. The safety limit mechanism works in conjunction with the clamping mechanism and the Z-axis mechanism.

[0006] Furthermore, the safety limiting mechanism includes a self-locking disc fixed to the outer periphery of the nut seat, a mounting base fixed to one side of the lever arm, a self-locking mechanism fixed on the mounting base, a slider rotatably connected to the self-locking mechanism, and two sets of symmetrically arranged axial sleeves connected in the self-locking mechanism in the vertical direction via a spline structure. An actuating airbag is sandwiched between the two sets of axial sleeves, and a clutch plate is fixed to the side of the two sets of axial sleeves that are far apart from each other. The clutch plate is provided with meshing teeth on the side opposite to the self-locking disc. Both the axial sliding sleeve and the self-locking mechanism are fixed with a clutch spring. The clutch spring has an elastic force that drives the two sets of axial sliding sleeves to approach each other. In the free state, the clutch plate engages with the meshing teeth on the self-locking disc to lock and achieve self-locking positioning of the Z-axis mechanism.

[0007] Furthermore, the safety limiting mechanism also includes a triggering mechanism disposed within the clamping mechanism. The clamping mechanism includes an outer housing fixed to the end of the lever arm. A drive shaft is rotatably connected within the outer housing. A coaxial slide rod is sleeved at the bottom end of the drive shaft. A limiting slide rod is fixed at the top of the coaxial slide rod. A limiting air chamber that cooperates with the limiting slide rod is provided at the bottom end of the drive shaft. A tension spring is also clamped between the coaxial slide rod and the drive shaft. The top of the coaxial slide rod extends to the outer side of the bottom end of the outer housing and detachably clamps the tool. The triggering mechanism includes an annular seat fixed to the outer wall of the coaxial slide rod. Several arc-shaped elastic rods are evenly fixed at the top of the annular seat. Each arc-shaped elastic rod has a support end fixed at its top. The outer wall of the coaxial slide rod is provided with a storage groove for accommodating the support end. The inner wall of the drive shaft is provided with a snap-fit ​​protrusion that mates with the top of the support end and a contact sensor that mates with the arc-shaped elastic rod. The contact sensor is used to monitor the collision or overload trigger signal of the clamping mechanism.

[0008] Furthermore, the tension spring has an elastic force that drives the coaxial slide rod to move downward away from the drive shaft. The coaxial slide rod has a built-in electromagnetic core. The outer shell has an upper magnetic ring fixed at the top of the coaxial slide rod, and the drive shaft has a lower magnetic ring fixed at the bottom of the coaxial slide rod. When the coaxial slide rod is in normal use, the upper magnetic ring has a downward magnetic repulsive force on the coaxial slide rod, and the lower magnetic ring has a downward magnetic attraction force on the coaxial slide rod. The clamping mechanism is also equipped with a control unit, which is used to adjust the magnitude and direction of the magnetic force of the electromagnetic core inside the coaxial slide bar, so as to control the lifting and lowering of the coaxial slide bar and the clamping state of the tool.

[0009] Furthermore, the arc-shaped elastic rod has an elastic force away from the contact sensor, and the top of the support end is provided with a snap-fit ​​flat end for engaging with the snap-fit ​​protrusion and a guide inclined end for guiding the support end to slide along the snap-fit ​​protrusion. The snap-fit ​​flat end cooperates with the snap-fit ​​protrusion to lock the position of the coaxial slide rod, and the guide inclined end is used to trigger the guide unlocking of the mechanism.

[0010] Furthermore, a pressure sensor is connected between the bottom of the coaxial slide rod and the drive shaft. The pressure sensor is used to monitor the pressure value between the coaxial slide rod and the drive shaft when it moves down. A gap sensor is also fixed to the top of the coaxial slide rod. The gap sensor is used to monitor the gap between the coaxial slide rod and the drive shaft. The pressure sensor, the spacing sensor, and the electromagnetic core inside the coaxial slide rod are all electrically connected to the control unit. The control unit controls the operation of the safety limit mechanism based on the signals from the pressure sensor and the spacing sensor.

[0011] Furthermore, the drive shaft is provided with an air passage, the top of the outer shell is provided with an air guide slip ring, the bottom end of the air passage is connected to the limiting air chamber, the top end of the air passage is connected to the input end of the air guide slip ring, and the output end of the air guide slip ring is connected to the actuator airbag through an air guide pipe to realize the air circuit linkage between the triggering mechanism and the self-locking mechanism.

[0012] Furthermore, the slider is also equipped with a pneumatic brake. The air supply structure of the pneumatic brake is connected to the air guide pipe. When the triggering mechanism is triggered, the control unit supplies air to the execution airbag through the air guide pipe and simultaneously supplies air to the pneumatic brake to realize the emergency braking of the Z-axis mechanism.

[0013] Furthermore, the tool magazine includes a translation cylinder fixed to one side of the column, a tool changing motor is fixed to the output end of the translation cylinder, a tool disc is fixed to the output end of the tool changing motor, and a plurality of elastic clamping ports that cooperate with the tools are evenly distributed at equal angles on the tool disc, and a protective cover is sleeved on the outside of the tool changing motor. The tool magazine is driven by a translation cylinder to move the tool changing motor and the tool disc. The tool changing motor drives the tool disc to rotate, thereby realizing automatic tool changing.

[0014] Compared to existing technologies, the advantages of this application are: The safety limit mechanism proposed in this invention works in conjunction with the clamping mechanism and the Z-axis mechanism. Through the coordinated action of the triggering mechanism, the self-locking mechanism, and the pneumatic brake, it can quickly trigger self-locking and emergency braking when the clamping mechanism collides or the drive is overloaded, thus avoiding damage to the tool, spindle, Z-axis mechanism, and workpiece. At the same time, the Z-axis servo motor has an automatic brake function, which further improves the reliability of safety protection. Attached Figure Description

[0015] Figure 1This is a schematic diagram of the overall structure of this application; Figure 2 This is a front view of the internal structure of this application; Figure 3 This is an exploded structural diagram of the tool magazine proposed in this application; Figure 4 This is a rear view of the internal structure of this application; Figure 5 This is a front structural schematic diagram of the Z-axis mechanism proposed in this application; Figure 6 This is a schematic diagram of the back structure of the Z-axis mechanism proposed in this application; Figure 7 This is a cross-sectional structural diagram of the Z-axis mechanism proposed in this application; Figure 8 for Figure 7 Enlarged structural diagram of section A in the middle; Figure 9 This is a cross-sectional structural diagram of the clamping mechanism proposed in this application; Figure 10 for Figure 9 Enlarged structural diagram of section B in the middle; Figure 11 This is an exploded structural diagram of the clamping mechanism proposed in this application; Figure 12 This is a schematic diagram of the triggering mechanism proposed in this application; Figure 13 This is a schematic diagram showing the force direction of the coaxial slide bar proposed in this application.

[0016] Explanation of the labels in the diagram: 1. Base; 2. Machine tool housing; 3. Column; 31. Slide rail; 32. Z-axis lead screw; 4. Z-axis mechanism; 41. Lever arm; 42. Mounting base; 43. Slider; 431. Pneumatic brake; 44. Self-locking mechanism; 45. Nut seat; 441. Axial sleeve; 442. Actuating air chamber; 443. Clutch spring; 444. Clutch plate; 451. Self-locking disc; 5. Tool magazine; 51. Translation cylinder; 52. Tool changer motor; 53. Tool disc; 531. Flexible clamping port; 54. Protective cover; 6. XY axis mechanism; 7. Workbench; 71. Fixture; 8. Clamping mechanism; 801. Air guide tube; 81. Outer shell; 811. Upper magnetic ring; 82. Drive shaft; 821. Limiting air chamber; 822. Air passage; 823. Snap-fitting flange; 824. Contact sensor; 83. Tension spring; 84. Coaxial slide bar; 841. Limiting slide bar; 842. Storage groove; 85. Air guide slip ring; 86. Triggering mechanism; 861. Support end; 8611. Snap-fitting flat end; 8612. Guide inclined end; 862. Arc-shaped elastic rod; 863. Ring seat; 87. Lower magnetic ring; 88. Spacing sensor; 89. Pressure sensor; 9. Knives. Detailed Implementation

[0017] The embodiments will be described clearly and completely with reference to the accompanying drawings. All other embodiments obtained by those skilled in the art based on the embodiments in this application without creative effort are within the scope of protection of this application.

[0018] Example: This invention provides a five-axis linkage engraving and milling machine. Please refer to [link / reference]. Figure 1 - Figure 13 It includes a base 1, machine tool housing 2, column 3, Z-axis mechanism 4, clamping mechanism 8, tool magazine 5, XY-axis mechanism 6, worktable 7, and safety limit mechanism. All components work together to achieve five-axis linkage engraving and milling, automatic tool changing, and safety limit protection. The specific structure is as follows: Please refer to this first. Figure 1 The base 1, serving as the installation foundation for the entire machine, is integrally molded from gray iron 300, possessing sufficient structural strength and stability. It supports all components, including the column 3 and the XY axis mechanism 6, preventing vibration during processing and ensuring machining accuracy. A precast concrete foundation is required for the base 1 to be installed in conjunction with the entire machine.

[0019] The machine tool housing 2 is located on top of the base 1 and is made of sheet metal material that meets safety standards. It forms a protective chamber to protect all moving parts and electrical components on the base 1, preventing chips and dust from entering the equipment during processing. It also protects the personal safety of operators and avoids accidents. It has a pleasant appearance and reliable protection, meeting the standard requirements for machine tool protection.

[0020] The column 3 is fixed to the base 1 and secured with bolts to ensure a firm connection. The column 3 is also made of gray iron 300 material and features a complete heat treatment process to eliminate residual stress, ensuring sufficient strength, rigidity, and high stability, thanks to 3D computer-aided design optimization. For more details, please refer to [link to relevant documentation]. Figure 5 - Figure 6The column 3 includes two sets of vertically and symmetrically arranged slide rails 31. The slide rails 31 are P-grade ball bearing guides. The two sets of slide rails 31 are arranged in parallel, resulting in low dynamic and static friction with the slider 43, low wear, high positioning accuracy, high sensitivity, low high-speed vibration, long service life, and interchangeability. A Z-axis lead screw 32 is rotatably connected between the two sets of slide rails 31. The Z-axis lead screw 32 is a ground C5-grade ball bearing screw, driven by a Z-axis servo motor (Huichuan brand). The Z-axis servo motor is directly connected to the Z-axis lead screw 32 via a flexible coupling, reducing intermediate links and achieving backlash-free transmission. This results in flexible feeding, accurate positioning, and high transmission precision. The Z-axis servo motor also has an automatic brake function; in the event of a power failure, it automatically brakes and holds the motor shaft, preventing rotation and providing safety protection. The forward and reverse rotation of the Z-axis servo motor drives the Z-axis lead screw 32 to rotate, thereby driving the Z-axis mechanism 4 to rise and fall vertically.

[0021] The Z-axis mechanism 4 includes a lever arm 41 slidably connected to the column 3 in the vertical direction. The lever arm 41 is made of aluminum alloy, combining lightweight and structural strength. A slider 43 that mates with the slide rail 31 and a nut seat 45 that mates with the Z-axis lead screw 32 are fixed to one side of the lever arm 41. The slider 43 slides with the slide rail 31 to guide the sliding of the lever arm 41. The nut seat 45 is threaded with the Z-axis lead screw 32. When the Z-axis lead screw 32 rotates, the nut seat 45 drives the lever arm 41 to rise and fall vertically along the slide rail 31, thereby driving the clamping mechanism 8 and the tool 9 to rise and fall, achieving machining feed in the Z-axis direction. The Z-axis travel range is 450mm.

[0022] Please refer to this first. Figure 5 - Figure 11 The clamping mechanism 8 is located on the other side of the lever arm 41 and is used to clamp the tool 9, ensuring that the tool 9 does not loosen or shift during machining, thus guaranteeing machining accuracy. The clamping mechanism 8 is linked with the Z-axis mechanism 4, rising and falling together with the Z-axis mechanism 4, and can also achieve its own rotational movement. In conjunction with the movement of the XY-axis mechanism 6 and the worktable 7, it realizes five-axis linkage machining. The machine tool adopts a column AC five-axis structure and has a tool tip following function. The drive shaft 82 inside the clamping mechanism 8 is connected to the spindle. The spindle adopts a domestic high-end 80 spindle with a diameter of φ80mm, featuring high precision and high rigidity. The bearings are P4 grade. After the entire spindle is assembled under constant temperature conditions, it has passed dynamic balancing and running-in tests, improving the service life and reliability of the entire spindle. The spindle can achieve stepless speed regulation within its speed range, with a speed of up to 24000r / min. The spindle power is 2.2kW. The spindle is controlled by an encoder, which can realize spindle orientation and rigidity functions. The spindle can be equipped with a chilled water circulating water cooling system.

[0023] Please refer to this first. Figure 3The tool magazine 5 is located on one side of the column 3 and is fixedly connected to the column 3 by bolts. It is used to provide tools 9 for the clamping mechanism 8. The tool magazine 5 is an automatic tool changer structure, installed on the side, which can realize the automatic storage and switching of tools 9 without manual intervention, greatly improving the tool changing efficiency. When changing tools, the tool disc 53 is driven and positioned by a servo motor and harmonic reducer, and then coordinated with the XYZ three-axis linkage to make the tool changing process fast and accurate. In this embodiment, the tool magazine 5 has a capacity of 10 tools, a maximum tool weight of 5kg, a tool changing time of 3 seconds, a tool diameter clamping range of 1-13φ, and a tool length range of 10-150mm.

[0024] The XY axis mechanism 6 is fixed on the base 1 and adopts a cross slide structure. It consists of an X-axis servo motor, a Y-axis servo motor, an X-axis lead screw, a Y-axis lead screw, and guide rails. The X and Y axis lead screws are ground C5 grade ball screws, directly connected by a flexible coupling to achieve backlash-free transmission. The travel range of both the X and Y axes is 350mm. It is used to drive the worktable 7 to move in conjunction with the XY axis, realizing the movement and feeding of the workpiece on the horizontal plane. It works in conjunction with the Z-axis mechanism 4 and the clamping mechanism 8 to complete the five-axis linkage engraving and milling machining.

[0025] The worktable 7 is fixed to the output end of the XY-axis mechanism 6 and moves along the XY-axis with the mechanism. The machining surface of the worktable 7 is φ180mm, equipped with an M8 T-slot, and has a maximum load capacity of 30kg. A clamp 71 for holding the workpiece is fixed at the top of the worktable 7. The clamp 71 can be adjusted according to the shape and size of the workpiece to achieve a firm grip on the workpiece, prevent the workpiece from shifting during machining, and ensure machining accuracy.

[0026] The safety limit mechanism is used to prevent the clamping mechanism 8 from experiencing drive overload failure. The safety limit mechanism works in conjunction with the clamping mechanism 8 and the Z-axis mechanism 4. When the clamping mechanism 8 experiences a collision or drive overload, it can quickly trigger self-locking and braking to protect the clamping mechanism 8, the Z-axis mechanism 4, the tool 9, and the workpiece.

[0027] Furthermore, the safety limiting mechanism includes a self-locking disc 451 fixed to the outer periphery of the nut seat 45. The self-locking disc 451 is coaxially arranged with the nut seat 45 and fixed by a key connection, rotating together with the nut seat 45. A mounting base 42 is fixed to one side of the lever arm 41. The mounting base 42 is integrally formed with the lever arm 41 or fixed by bolts. A self-locking mechanism 44 is fixed on the mounting base 42. The self-locking mechanism 44 is fixed to the mounting base 42 by bolts. The slider 43 is rotatably connected to the self-locking mechanism 44, realizing the relative rotation of the slider 43 and the self-locking mechanism 44.

[0028] Within the self-locking mechanism 44, two symmetrically arranged axial sleeves 441 are connected in a vertical direction via a spline structure. The spline structure allows the axial sleeves 441 to slide vertically while limiting their rotation, ensuring the stability of their movement. An actuating airbag 442 is sandwiched between the two sets of axial sleeves 441. The actuating airbag 442 is made of a high-pressure, high-temperature resistant elastic material and can move the axial sleeves 441 vertically by inflating and deflating. The air pressure in the actuating airbag 442 comes from the compressed gas in the limiting air chamber 821.

[0029] Both sets of axial sliding sleeves 441 have a clutch plate 444 fixed on the side away from each other. The clutch plate 444 is fixed to the axial sliding sleeve 441 by bolts. The clutch plate 444 and the self-locking disc 451 are provided with meshing teeth on the side opposite to each other. The meshing teeth adopt a helical tooth structure, which can realize the fixation of the nut seat 45 and the self-locking mechanism 44, so that the clutch plate 444 and the self-locking disc 451 are tightly engaged and locked.

[0030] A clutch spring 443 is fixed between the axial sliding sleeve 441 and the self-locking mechanism 44. The clutch spring 443 is sleeved on the outside of the axial sliding sleeve 441. The clutch spring 443 has an elastic force that drives the two sets of axial sliding sleeves 441 to approach each other. In the free state, the clutch plate 444 and the meshing teeth on the self-locking disc 451 are engaged and locked to realize the fixation of the nut seat 45 and the self-locking mechanism 44, realize the cooperation between the nut seat 45 and the Z-axis lead screw 32, and drive the Z-axis mechanism 4 to rise and fall normally.

[0031] The safety limit mechanism also includes a trigger mechanism 86 disposed within the clamping mechanism 8. The trigger mechanism 86 is used to monitor collision or overload signals of the clamping mechanism 8 and trigger the self-locking and braking actions of the safety limit mechanism. The clamping mechanism 8 includes an outer housing 81 fixed to the end of the lever arm 41. The outer housing 81 is fixed to the lever arm 41 by bolts. A drive shaft 82 is rotatably connected inside the outer housing 81. The drive shaft 82 is rotatably connected to the outer housing 81 through a bearing, enabling high-speed rotation and providing driving force for the tool 9.

[0032] A coaxial slide rod 84 is sleeved at the bottom end of the drive shaft 82. The coaxial slide rod 84 is coaxially arranged with the drive shaft 82. A limiting slide rod 841 is fixed at the top of the coaxial slide rod 84. The limiting slide rod 841 and the coaxial slide rod 84 are integrally formed. The bottom end of the drive shaft 82 is provided with a limiting air cavity 821 that cooperates with the limiting slide rod 841. The limiting slide rod 841 is inserted into the limiting air cavity 821 and can slide vertically along the limiting air cavity 821. At the same time, it restricts the relative rotation between the coaxial slide rod 84 and the drive shaft 82, ensuring that the rotational power of the drive shaft 82 can be transmitted to the coaxial slide rod 84, thereby driving the tool 9 to rotate.

[0033] A tension spring 83 is also clamped between the coaxial slide bar 84 and the drive shaft 82. The tension spring 83 is sleeved on the outside of the limiting slide bar 841. The tension spring 83 has the elastic force to drive the coaxial slide bar 84 downward away from the drive shaft 82, ensuring that the tool 9 can maintain a stable clamping state during normal machining. The top of the coaxial slide bar 84 extends to the outside of the bottom end of the housing 81 and detachably clamps the tool 9. The tool 9 and the coaxial slide bar 84 are detachably connected by a chuck, which facilitates the replacement and maintenance of the tool 9 and is compatible with the automatic tool changing action of the tool magazine 5.

[0034] The triggering mechanism 86 includes an annular seat 863 fixed to the outer wall of the coaxial slide bar 84. The annular seat 863 is connected and fixed to the coaxial slide bar 84 by a key and rises and falls together with the coaxial slide bar 84. Several arc-shaped elastic rods 862 are evenly fixed at equal angles on the top of the annular seat 863. The arc-shaped elastic rods 862 are made of elastic metal material and have good elastic restoring ability. The top of each arc-shaped elastic rod 862 is fixed with a support end 861. The support end 861 is integrally formed with the arc-shaped elastic rod 862. The outer wall of the coaxial slide bar 84 is provided with a storage groove 842 for storing the support end 861. The size of the storage groove 842 is adapted to the support end 861 to ensure that the support end 861 can be smoothly stored in the storage groove 842 and avoid interfering with the normal movement of the coaxial slide bar 84. The inner wall of the drive shaft 82 is provided with a snap-fit ​​protrusion 823 that mates with the top of the support end 861 and a contact sensor 824 that mates with the arc-shaped elastic rod 862. The contact sensor 824 is used to monitor the collision or overload trigger signal of the clamping mechanism 8. The contact sensor 824 is electrically connected to the control unit and can quickly transmit the trigger signal to the control unit.

[0035] The tension spring 83 has the elastic force to drive the coaxial slide bar 84 downward away from the drive shaft 82. The coaxial slide bar 84 has a built-in electromagnetic core. The outer shell 81 has an upper magnetic ring 811 fixed on the top of the coaxial slide bar 84, and the drive shaft 82 has a lower magnetic ring 87 fixed on the bottom of the coaxial slide bar 84. When the coaxial slide bar 84 is in normal use, the upper magnetic ring 811 has a downward magnetic repulsive force on the coaxial slide bar 84, and the lower magnetic ring 87 has a downward magnetic attraction force on the coaxial slide bar 84. The dual magnetic forces, together with the elastic force of the tension spring 83, ensure the stable positioning of the coaxial slide bar 84, thereby ensuring the clamping stability of the tool 9.

[0036] The clamping mechanism 8 is also equipped with a control unit, which is linked with the CNC system of the whole machine. The CNC system has functions such as automatic tool setting and changing, five-axis linkage, and tool tip following. The control unit is used to adjust the magnitude and direction of the magnetic force of the electromagnetic core in the coaxial slide bar 84 to control the lifting and lowering of the coaxial slide bar 84 and the clamping state of the tool 9, so as to ensure that the tool 9 is firmly clamped and can be changed smoothly.

[0037] The arc-shaped elastic rod 862 has elastic force away from the contact sensor 824. The top of the support end 861 is provided with a snap-fit ​​flat end 8611 for engaging with the snap-fit ​​protrusion 823 and a guide inclined end 8612 for guiding the support end 861 to slide along the snap-fit ​​protrusion 823. The snap-fit ​​flat end 8611 and the snap-fit ​​protrusion 823 cooperate to lock the position of the coaxial slide rod 84, ensuring that the coaxial slide rod 84 does not undergo axial displacement during normal processing. The guide inclined end 8612 is used to trigger the guide unlocking of the mechanism 86. When the clamping mechanism 8 collides or is overloaded, the coaxial slide rod 84 is forced upward, and the guide inclined end 8612 slides along the snap-fit ​​protrusion 823, causing the arc-shaped elastic rod 862 to deform towards the contact sensor 824, triggering the contact sensor 824 to send a signal.

[0038] A pressure sensor 89 is connected between the bottom of the coaxial slide rod 84 and the drive shaft 82. The pressure sensor 89 is used to monitor the pressure value between the coaxial slide rod 84 and the drive shaft 82 as it moves downward. A gap sensor 88 is also fixed to the top of the coaxial slide rod 84. The gap sensor 88 is used to monitor the gap between the coaxial slide rod 84 and the drive shaft 82. The pressure sensor 89, the gap sensor 88, and the electromagnetic core inside the coaxial slide rod 84 are all electrically connected to the control unit. The control unit controls the action of the safety limit mechanism based on the signals from the pressure sensor 89 and the gap sensor 88. When the pressure value or gap exceeds the preset range, the control unit triggers the safety limit mechanism to start, thereby achieving overload protection.

[0039] The drive shaft 82 is also provided with an air passage 822, and the top of the outer shell 81 is provided with an air guide slip ring 85. The bottom end of the air passage 822 is connected to the limiting air chamber 821, and the top end of the air passage 822 is connected to the input end of the air guide slip ring 85. The output end of the air guide slip ring 85 is connected to the actuator airbag 442 through the air guide pipe 801 to realize the air circuit linkage between the trigger mechanism 86 and the self-locking mechanism 44. The setting of the air guide slip ring 85 ensures that the air circuit does not get tangled and the connection is stable when the drive shaft 82 rotates.

[0040] The slider 43 is also equipped with a pneumatic brake 431. The air supply structure of the pneumatic brake 431 is connected to the air guide pipe 801. When the triggering mechanism 86 is triggered, the control unit supplies air to the actuator airbag 442 through the air guide pipe 801 and at the same time supplies air to the pneumatic brake 431 to realize the emergency braking of the Z-axis mechanism 4, quickly stop the lifting and lowering movement of the Z-axis mechanism 4, avoid equipment damage caused by collision or overload, and improve the response speed of safety protection.

[0041] The tool magazine 5 includes a translation cylinder 51 fixed to one side of the column 3. A tool changing motor 52 is fixed to the output end of the translation cylinder 51, and a tool disc 53 is fixed to the output end of the tool changing motor 52. The tool disc 53 is provided with several elastic clamping ports 531 at equal angles to cooperate with the tools 9. The elastic clamping ports 531 can accommodate tools 9 of different sizes to ensure the stable storage of the tools 9 in the tool magazine 5. A protective cover 54 is sleeved on the outside of the tool changing motor 52. The protective cover 54 is used to protect the tool changing motor 52 and the tool disc 53, prevent chips and dust from entering, and extend the service life. The tool magazine 5 drives the tool changing motor 52 and the tool disc 53 to move through the translation cylinder 51, and drives the tool disc 53 to rotate through the tool changing motor 52, so as to realize the automatic replacement of the tools 9. The tool changing action is linked with the control unit and the CNC system.

[0042] Before processing, the workpiece is fixed on the worktable 7 by the fixture 71. The control unit controls the tool magazine 5 to move, the translation cylinder 51 drives the tool disc 53 to move, and the tool changer motor 52 drives the tool disc 53 to rotate, so that the required tool 9 is sent to the lower part of the clamping mechanism 8. The control unit adjusts the magnetic force of the electromagnetic core in the coaxial slide bar 84, and with the cooperation of the tension spring 83, the upper magnetic ring 811 and the lower magnetic ring 87, the coaxial slide bar 84 moves down to clamp the tool 9, thus completing the automatic tool change.

[0043] During machining, the Z-axis servo motor drives the Z-axis lead screw 32 to rotate, which in turn raises and lowers the power arm 41, clamping mechanism 8 and tool 9. The XY-axis mechanism 6 drives the worktable 7 to move along the XY axis, and the clamping mechanism 8 drives the tool 9 to rotate, thus realizing five-axis linkage engraving and milling machining.

[0044] When the clamping mechanism 8 experiences a collision or drive overload, the coaxial slide bar 84 moves upward under force, the limiting slide bar 841 moves upward along the limiting air chamber 821, and the guide inclined end 8612 of the support end 861 slides along the snap-fit ​​protrusion 823, causing the arc-shaped elastic rod 862 to deform towards the contact sensor 824. The contact sensor 824 sends a trigger signal to the control unit. At the same time, the pressure value monitored by the pressure sensor 89 and the distance monitored by the distance sensor 88 exceed the preset range, further sending signals to the control unit.

[0045] After receiving the signal, the control unit immediately changes the direction of the magnetic field of the electromagnetic core inside the coaxial slide bar 84, causing the upper magnetic ring 811 to generate an upward magnetic attraction force on the coaxial slide bar 84, and the lower magnetic ring 87 to generate an upward magnetic repulsion force on the coaxial slide bar 84. This drives the coaxial slide bar 84 to move upward instantaneously. At this time, the limit slide bar 841 moves upward and compresses the air chamber of the limit air chamber 821, and supplies air to the actuator airbag 442 through the air guide pipe 801. The actuator airbag 442 expands, pushing the two sets of axial sliding sleeves 441 away from each other. The clutch plate 444 disengages from the self-locking disc 451, releasing the self-locking of the Z-axis mechanism 4. At this time, the nut seat 45 is in a self-locking position. In the current state, the Z-axis mechanism 4 no longer engages with the Z-axis lead screw 32 for drive, and thus no longer undergoes displacement in the Z-axis direction. Simultaneously, the control unit supplies air to the pneumatic brake 431, which activates to achieve emergency braking of the Z-axis mechanism 4, preventing damage to the equipment and workpiece. After the overload or collision is resolved, the limit slide bar 841 moves down to reset by changing the magnetic field, creating negative pressure in the pressure limit air chamber 821. This causes the gas in the actuator air bag 442 to be adsorbed, causing the actuator air bag 442 to contract. The clutch spring 443 pushes the axial sliding sleeve 441 to reset, and the clutch plate 444 re-engages with the self-locking disc 451, resuming normal processing.

[0046] The safety limit mechanism proposed in this invention works in conjunction with the clamping mechanism 8 and the Z-axis mechanism 4. Through the coordinated action of the triggering mechanism 86, the self-locking mechanism 44, and the pneumatic brake 431, the self-locking and emergency braking can be quickly triggered when the clamping mechanism 8 collides or is overloaded, so as to avoid damage to the tool 9, the spindle, the Z-axis mechanism 4 and the workpiece. At the same time, the Z-axis servo motor has an automatic brake function, which further improves the reliability of safety protection.

[0047] The above description is only the best implementation method adopted in this application in combination with current practical needs, but the scope of protection of this application is not limited thereto.

Claims

1. A five-axis linkage engraving and milling machine, characterized in that, include: Base (1); The machine tool housing (2) is located on top of the base (1) and is used for equipment protection; The column (3) is fixed on the base (1) and includes two sets of vertically and symmetrically arranged slide rails (31). A Z-axis lead screw (32) is rotatably connected between the two sets of slide rails (31). The Z-axis lead screw (32) is driven by a Z-axis servo motor. Z-axis mechanism (4) includes a lever arm (41) that is slidably connected to the column (3) in the vertical direction. One side of the lever arm (41) is fixed with a slider (43) that cooperates with the slide rail (31) and a nut seat (45) that cooperates with the Z-axis lead screw (32). The clamping mechanism (8) is located on the other side of the lever arm (41) and is used to clamp the cutting tool (9). The tool magazine (5) is located on one side of the column (3) and is used to provide tools (9) for the clamping mechanism (8). The tool magazine (5) is an automatic tool changer. The XY axis mechanism (6) is fixed on the base (1) and is used to drive the worktable (7) to move in XY axis linkage. The worktable (7) is fixed to the output end of the XY axis mechanism (6), and the top of the worktable (7) is fixed with a clamp (71) for clamping the workpiece. A safety limit mechanism is used to prevent the clamping mechanism (8) from experiencing a drive overload failure. The safety limit mechanism is linked and cooperates with the clamping mechanism (8) and the Z-axis mechanism (4). The safety limiting mechanism includes a self-locking disc (451) fixed to the outer periphery of the nut seat (45), a mounting base (42) fixed on one side of the lever arm (41), a self-locking mechanism (44) fixed on the mounting base (42), a slider (43) rotatably connected to the self-locking mechanism (44), and two sets of symmetrically arranged axial sleeves (441) connected in the self-locking mechanism (44) in the vertical direction through a spline structure. An actuating airbag (442) is sandwiched between the two sets of axial sleeves (441), and a clutch plate (444) is fixed on the side of the two sets of axial sleeves (441) that are far apart. The clutch plate (444) and the side opposite to the self-locking disc (451) are provided with meshing teeth. The safety limiting mechanism also includes a triggering mechanism (86) disposed in the clamping mechanism (8). The clamping mechanism (8) includes an outer shell (81) fixed to the end of the lever arm (41). A drive shaft (82) is rotatably connected inside the outer shell (81). A coaxial slide rod (84) is sleeved at the bottom end of the drive shaft (82). The triggering mechanism (86) includes an annular seat (863) fixed to the outer wall of the coaxial slide bar (84). Several arc-shaped elastic rods (862) are evenly fixed at the top of the annular seat (863). Each arc-shaped elastic rod (862) has a support end (861) fixed at its top. The outer wall of the coaxial slide bar (84) is provided with a storage groove (842) for storing the support end (861). The inner wall of the drive shaft (82) is provided with a snap-fit ​​protrusion (823) that cooperates with the top of the support end (861) and a contact sensor (824) that cooperates with the arc-shaped elastic rod (862). The contact sensor (824) is used to monitor the collision or overload trigger signal of the clamping mechanism (8).

2. A five-axis linkage engraving and milling machine according to claim 1, characterized in that, A clutch spring (443) is fixed between the axial sliding sleeve (441) and the self-locking mechanism (44). The clutch spring (443) has an elastic force that drives the two sets of axial sliding sleeves (441) to approach each other. When the clutch spring (443) is in a free state, the clutch plate (444) engages with the meshing teeth on the self-locking disc (451) to lock and achieve self-locking positioning of the Z-axis mechanism (4).

3. A five-axis linkage engraving and milling machine according to claim 2, characterized in that, The top of the coaxial slide rod (84) is fixed with a limiting slide rod (841), and the bottom end of the drive shaft (82) is provided with a limiting air chamber (821) that cooperates with the limiting slide rod (841). A tension spring (83) is also sandwiched between the coaxial slide rod (84) and the drive shaft (82). The top of the coaxial slide rod (84) extends to the outside of the bottom end of the outer shell (81) and detachably holds the cutting tool (9).

4. A five-axis linkage engraving and milling machine according to claim 3, characterized in that, The tension spring (83) has an elastic force that drives the coaxial slide rod (84) to move downward away from the drive shaft (82). The coaxial slide rod (84) has a built-in electromagnetic core. The outer shell (81) has an upper magnetic ring (811) fixed at the top of the coaxial slide rod (84). The drive shaft (82) has a lower magnetic ring (87) fixed at the bottom of the coaxial slide rod (84). When the coaxial slide rod (84) is in normal use, the upper magnetic ring (811) has a downward magnetic repulsion force on the coaxial slide rod (84), and the lower magnetic ring (87) has a downward magnetic attraction force on the coaxial slide rod (84). The clamping mechanism (8) is also equipped with a control unit, which is used to adjust the magnitude and direction of the magnetic force of the electromagnetic core in the coaxial slide (84) to control the lifting and lowering of the coaxial slide (84) and the clamping state of the tool (9).

5. A five-axis linkage engraving and milling machine according to claim 4, characterized in that, The arc-shaped elastic rod (862) has an elastic force away from the contact sensor (824). The top of the support end (861) is provided with a snap-fit ​​flat end (8611) for engaging with the snap-fit ​​protrusion (823) and a guide inclined end (8612) for guiding the support end (861) to slide along the snap-fit ​​protrusion (823). The snap-fit ​​flat end (8611) and the snap-fit ​​protrusion (823) cooperate to lock the position of the coaxial slide rod (84). The guide inclined end (8612) is used to trigger the guide unlocking of the mechanism (86).

6. A five-axis linkage engraving and milling machine according to claim 4, characterized in that, A pressure sensor (89) is also connected between the bottom of the coaxial slide rod (84) and the drive shaft (82). The pressure sensor (89) is used to monitor the pressure value between the coaxial slide rod (84) and the drive shaft (82) when the coaxial slide rod (84) moves down. A gap sensor (88) is also fixed to the top of the coaxial slide rod (84). The gap sensor (88) is used to monitor the gap between the coaxial slide rod (84) and the drive shaft (82). The electromagnetic cores inside the pressure sensor (89), the spacing sensor (88), and the coaxial slide bar (84) are all electrically connected to the control unit. The control unit controls the operation of the safety limit mechanism based on the signals from the pressure sensor (89) and the spacing sensor (88).

7. A five-axis linkage engraving and milling machine according to claim 4, characterized in that, The drive shaft (82) is also provided with an air passage (822), and the top of the outer shell (81) is provided with an air guide slip ring (85). The bottom end of the air passage (822) is connected to the limiting air chamber (821), and the top end of the air passage (822) is connected to the input end of the air guide slip ring (85). The output end of the air guide slip ring (85) is connected to the execution airbag (442) through the air guide pipe (801) to realize the air circuit linkage between the trigger mechanism (86) and the self-locking mechanism (44).

8. A five-axis linkage engraving and milling machine according to claim 7, characterized in that, The slider (43) is also equipped with a pneumatic brake (431). The air supply structure of the pneumatic brake (431) is connected to the air guide pipe (801). When the triggering mechanism (86) is triggered, the control unit supplies air to the execution airbag (442) through the air guide pipe (801) and supplies air to the pneumatic brake (431) at the same time, so as to realize the emergency braking of the Z-axis mechanism (4).

9. A five-axis linkage engraving and milling machine according to claim 1, characterized in that, The tool magazine (5) includes a translation cylinder (51) fixed to one side of the column (3). A tool changing motor (52) is fixed to the output end of the translation cylinder (51). A tool disc (53) is fixed to the output end of the tool changing motor (52). Several elastic clamping ports (531) that cooperate with the tool (9) are evenly distributed at equal angles on the tool disc (53). A protective cover (54) is sleeved on the outside of the tool changing motor (52). The tool magazine (5) drives the tool changer motor (52) and the tool disc (53) to move through the translation cylinder (51), and drives the tool disc (53) to rotate through the tool changer motor (52), thereby realizing the automatic replacement of the tool (9).

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