Large electric spark forming machine tool

Abstract

The invention provides an electric spark forming machining tool, relates to the technical field of electric spark machining tools, and solves the problem of contradiction between high acceleration and high speed requirements and high rigidity and large torque requirements of a machine tool servo shaft for machining of narrow-groove narrow-slit and large-area molded surface molds. The device comprises an X-axis module, a Y-axis module, a Z-axis module and a W-axis module, the Y-axis module is arranged at the driving end of the X-axis module, the Z-axis module is arranged at the driving end of the Y-axis module, the W-axis module is arranged at the driving end of the Z-axis module, the driving direction of the Z-axis module is the same as that of the W-axis module, the Z-axis module comprises a speed reducing and torque increasing mechanism, and the W-axis module is of a motor direct-drive structure. The dynamic response characteristic of the W-axis module is higher than that of the Z-axis module. The dynamic response characteristic of the W-axis module is higher, the requirement for high-speed cutter lifting of narrow grooves and narrow slits can be met, and inertia matching with large moving parts is met through the Z-axis module.

Description

Technical Field

[0001] This invention relates to the field of electrical discharge machining (EDM) machine tool technology, and in particular to an EDM forming machine tool. Background Technology

[0002] With the booming development of my country's new energy vehicle industry, the demand for new product development is constantly rising, leading to a sharp increase in the demand for various automotive molds. In the automotive mold field, both die-casting molds and injection molds contain many large molds, and the processing of these molds generally utilizes large electrical discharge machining (EDM) machines. For EDM, there are generally two requirements for these molds: one is the machining of narrow grooves and slits in molds used as reinforcing ribs for parts; the other is the surface machining of larger body panel molds. Because these molds are large, often weighing several tons, they cannot be processed on small EDM machines. These two types of machining represent two contradictory requirements on large EDM machines. This is because EDM is performed on micron-level gaps, which is challenging for areas exceeding 400 cm². 2 In the above-described surface EDM machining, the negative pressure during tool lift-off is considerable, placing high demands on the clamping firmness of the tool electrode and the rigidity and strength of the servo spindle. Therefore, in large-area surface EDM, the tool lift-off start-up speed of the EDM servo axis must be as low as possible, and the servo axis system must have high rigidity to maintain the accuracy between the mold and the electrode. To obtain high torque from the servo axis, using a reduction gear instead of a direct connection between the motor and the lead screw is a better inertia matching method. However, machining narrow grooves and slits requires the highest possible tool lift-off start-up speed, because a higher tool lift-off acceleration results in a stronger ability to remove machining chips, which is a determining factor in the depth of narrow grooves that an EDM machine can machine.

[0003] Currently, most large EDM machines on the market use direct motor coupling to achieve high acceleration and sensitivity in order to adapt to the machining of narrow slots and gaps. However, due to the large mass of the components, large EDM machines have an inherent characteristic of large inertia. This makes it difficult to achieve inertia matching between the motor and the moving parts of the machine tool when directly coupled, resulting in difficulty in achieving the goal of high acceleration. Instead, it greatly reduces the maximum torque output capability of the servo axis. This compromise reduces the performance of narrow slot and gap machining and large-area EDM, falling far short of optimal performance. Summary of the Invention

[0004] The purpose of this invention is to provide an electrical discharge machining (EDM) machine tool that solves the contradiction between the high acceleration and high speed requirements and the high rigidity and high torque requirements of the machine tool servo axis in the machining of narrow slots, narrow gaps, and large-area surface molds. The numerous technical effects of the preferred solutions among the many technical solutions provided by this invention are detailed below.

[0005] To achieve the above objectives, the present invention provides the following technical solution: The present invention provides an electrical discharge machining (EDM) machine tool, comprising an X-axis module, a Y-axis module, a Z-axis module, and a W-axis module. The Y-axis module is disposed on the drive end of the X-axis module, the Z-axis module is disposed on the drive end of the Y-axis module, and the W-axis module is disposed on the drive end of the Z-axis module. The Z-axis module and the W-axis module drive in the same direction. The Z-axis module includes a speed reduction and torque amplification mechanism. The W-axis module is a direct-drive structure with a motor. The dynamic response characteristics of the W-axis module are higher than those of the Z-axis module.

[0006] Preferably, the W-axis module includes a moving part, and the moving part is made of a lightweight material.

[0007] Preferably, the W-axis module includes a W-axis base plate, a W-axis servo motor, a coupling, a W-axis lead screw, a W-axis guide rail, a W-axis slide, a W-axis frame, and a W-axis extension shaft. The W-axis base plate is disposed at the drive end of the Z-axis module. The W-axis servo motor, the coupling, and the W-axis guide rail are all disposed on the W-axis base plate. The drive end of the W-axis servo motor is connected to the W-axis lead screw via the coupling. The W-axis slide is slidably disposed on the W-axis guide rail. The W-axis lead screw is connected to the W-axis slide. The W-axis frame is disposed on the W-axis slide. The W-axis extension shaft is disposed at the bottom of the W-axis frame. Electrode assemblies are disposed on the W-axis extension shaft.

[0008] Preferably, both the W-axis substrate and the W-axis frame are made of aluminum alloy.

[0009] Preferably, the W-axis extension shaft is made of polymer resin.

[0010] Preferably, the Z-axis module includes a Z-axis mounting bracket, a Z-axis backplate, a Z-axis servo motor, a reduction and torque-increasing mechanism, a Z-axis lead screw, a Z-axis guide rail, a Z-axis slide, and a Z-axis frame. The Z-axis mounting bracket is disposed at the drive end of the Y-axis module, the Z-axis backplate is disposed on the Z-axis mounting bracket, the Z-axis servo motor is disposed on the Z-axis mounting bracket, the Z-axis guide rail is disposed on the Z-axis backplate, the Z-axis slide is slidably disposed on the Z-axis guide rail, the Z-axis servo motor is connected to the Z-axis lead screw through the reduction and torque-increasing mechanism, the Z-axis lead screw is connected to the Z-axis slide, the Z-axis frame is disposed on the Z-axis slide, and the W-axis module is disposed on the Z-axis frame.

[0011] Preferably, the speed reduction and torque amplification mechanism includes a driving pulley, a transmission belt, and a driven pulley. The driving pulley is disposed at the drive end of the Z-axis servo motor, the driven pulley is disposed on the Z-axis lead screw, and the transmission belt is disposed between the driving pulley and the driven pulley. The diameter of the driving pulley is smaller than the diameter of the driven pulley.

[0012] Preferably, the speed reduction and torque amplification mechanism is a gear reducer or a sprocket reducer.

[0013] The application employs the above technical solution and has at least the following beneficial effects: An electrical discharge machining (EDM) machine tool includes an X-axis module, a Y-axis module, a Z-axis module, and a W-axis module. The Y-axis module is mounted on the drive end of the X-axis module, the Z-axis module is mounted on the drive end of the Y-axis module, and the W-axis module is mounted on the drive end of the Z-axis module. The Z-axis and W-axis modules drive in the same direction. The Z-axis module includes a reduction and torque amplification mechanism. This mechanism allows the Z-axis module to achieve inertia matching between the motor and large moving parts, meeting the requirements for high torque and high inertia caused by the large lifting negative pressure resulting from the large area and narrow gap during large tool electrode discharge, thus ensuring machining accuracy. The W-axis module has a direct-drive motor structure. Its dynamic response characteristics are higher than those of the Z-axis module, resulting in greater acceleration. This meets the requirements for low spindle inertia and high acceleration in actual narrow groove and slot machining. Higher acceleration also improves chip removal in narrow groove and slot machining, enabling the machining of narrow grooves and slots with a greater depth ratio.

[0014] It should be understood that the above general description and the following detailed description are exemplary and explanatory only, and do not limit this application. Attached Figure Description

[0015] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0016] Figure 1 This is a schematic diagram of the electrical discharge machining machine tool provided in an embodiment of the present invention; Figure 2 This is a schematic diagram of the W-axis module structure provided in an embodiment of the present invention.

[0017] In the diagram: 1. X-axis module; 2. Y-axis module; 3. Z-axis module; 4. W-axis module; 5. W-axis base plate; 6. W-axis servo motor; 7. Coupling; 8. W-axis lead screw; 9. W-axis guide rail; 10. W-axis slide; 11. W-axis frame; 12. W-axis extension shaft; 13. Z-axis mounting bracket; 14. Z-axis back plate; 15. Z-axis servo motor; 16. Z-axis lead screw; 17. Z-axis guide rail; 18. Z-axis slide; 19. Z-axis frame; 20. Drive pulley; 21. Drive belt; 22. Driven pulley. Detailed Implementation

[0018] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be described in detail below. Obviously, the described embodiments are merely some embodiments of this invention, and not all embodiments. Based on the embodiments of this invention, all other implementation methods obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0019] A specific embodiment of the present invention provides an electrical discharge machining (EDM) machine tool, as shown in the attached figure. Figure 1 As shown, it mainly includes an X-axis module 1, a Y-axis module 2, a Z-axis module 3, and a W-axis module 4. The Y-axis module 2 is set on the drive end of the X-axis module 1, the Z-axis module 3 is set on the drive end of the Y-axis module 2, and the W-axis module 4 is set on the drive end of the Z-axis module 3. The Z-axis module 3 and the W-axis module 4 drive in the same direction. The Z-axis module includes a speed reduction and torque amplification mechanism. The W-axis module is a direct-drive structure of a motor. The dynamic response characteristics of the W-axis module are higher than those of the Z-axis module.

[0020] The core motion components of the machine tool consist of four modules: X-axis module 1, Y-axis module 2, Z-axis module 3, and W-axis module 4. Specifically, X-axis module 1 performs precise horizontal movement to meet the lateral position adjustment requirements during machining; Y-axis module 2, also horizontal but perpendicular to the X-axis module, achieves precise longitudinal positioning; Z-axis module 3 moves vertically to control the up-and-down movement of the machining tool, thus completing the machining task; and W-axis module 4 moves in the same direction as Z-axis module 3. Specifically, Y-axis module 2 is mounted on the drive end of X-axis module 1, Z-axis module 3 is vertically mounted on Y-axis module 2, and W-axis module 4 is positioned on the side of Z-axis module 3 closest to the machining area. The Z-axis module includes a reduction and torque amplification mechanism, enabling inertia matching between the motor and large moving parts. This meets the demands of large torque and inertia required by the large lifting negative pressure caused by the large area and narrow gap of the large tool electrode discharge, thereby ensuring machining accuracy. The W-axis module is a direct-drive motor structure. The dynamic response characteristics of the W-axis module are higher than those of the Z-axis module, resulting in a larger acceleration of the W-axis module. This can meet the requirements of small spindle inertia and large acceleration in the actual machining of narrow slots and gaps. The greater the acceleration, the better the chip removal in the machining of narrow slots and gaps, and the more depth ratio of narrow slots and gaps can be processed.

[0021] In a specific embodiment of this application, the W-axis module includes a moving part, which is made of a lightweight material. Using a lightweight material for the moving part can effectively reduce the mass of the moving end of the W-axis module, thereby reducing the inertial force during movement, ensuring that the W-axis module has greater acceleration, and further meeting the requirements of narrow slots and slits with a greater depth-to-depth ratio.

[0022] In some embodiments, in conjunction with the appendix Figure 1 and attached Figure 2As shown, the W-axis module 4 includes a W-axis base plate 5, a W-axis servo motor 6, a coupling 7, a W-axis lead screw 8, a W-axis guide rail 9, a W-axis slide 10, a W-axis frame 11, and a W-axis extension shaft 12. The W-axis base plate 5 is set on the drive end of the Z-axis module 3. The W-axis servo motor 6, the coupling 7, and the W-axis guide rail 9 are all set on the W-axis base plate 5. The drive end of the W-axis servo motor 6 is connected to the W-axis lead screw 8 through the coupling 7 to ensure accurate and efficient power transmission. The W-axis lead screw 8 is rotatably mounted on the W-axis base plate 5. W-axis guide rails 9 are arranged parallel to both sides of the lead screw 8, providing precise guidance for the movement of the W-axis slide 10. Driven by the lead screw 8, the slide 10 moves linearly along the guide rails 9. The slide 10 is slidably mounted on the guide rails 9 and threadedly engages with the lead screw 8. The W-axis frame 11 is mounted on the slide 10, and the W-axis extension shaft 12 is located at the bottom of the frame 11. Electrode assemblies are mounted on the extension shaft 12. One end of the extension shaft 12 is connected to the frame 11, and the other end is used to connect to the machine tool spindle. This structural arrangement ensures the stability of the connections between components and the precision of the transmission, thereby better realizing the various functions of the W-axis module.

[0023] In some embodiments, specifically, the W-axis base plate 5 and the W-axis frame 11 are both made of aluminum alloy. Aluminum alloy has the advantages of being lightweight, high-strength, and corrosion-resistant, which can effectively reduce the overall weight of the machine tool, making the acceleration of the W-axis module 4 sufficiently large, while ensuring the stability and reliability of the machine tool during long-term operation, reducing failures and maintenance costs caused by material problems, and improving the service life and machining accuracy of the machine tool.

[0024] Furthermore, the W-axis extension shaft 12 is made of polymer resin. Polymer resin has excellent insulation properties, high chemical stability, and light weight. Using this material for the W-axis extension shaft 12 further reduces the weight of the W-axis module, thereby increasing acceleration and enabling the machining of narrow slots and slits with greater depth ratios. Its insulating properties also ensure insulation between the upper W-axis frame 11 and the lower electrode assembly.

[0025] In some embodiments, in conjunction with the appendix Figure 1As shown, the Z-axis module 3 includes a Z-axis mounting bracket 13, a Z-axis backplate 14, a Z-axis servo motor 15, a reduction and torque amplification mechanism, a Z-axis lead screw 16, a Z-axis guide rail 17, a Z-axis slide 18, and a Z-axis frame 19. The Z-axis mounting bracket 13 is located at the drive end of the Y-axis module 2, providing a stable support foundation for the entire Z-axis module 3. The Z-axis backplate 14 is mounted on the Z-axis mounting bracket 13, serving to connect and support other components. The Z-axis servo motor 15 serves as the power source and is mounted on the Z-axis mounting bracket 13. The Z-axis guide rail 17 is mounted on the Z-axis backplate 14, and the Z-axis slide 18 is slidably mounted on the Z-axis guide rail 17, providing precise guidance for the movement of the Z-axis slide 18 and ensuring the smoothness and accuracy of the movement. Z-axis servo motor 15 is connected to Z-axis lead screw 16 via a reduction and torque amplification mechanism. Z-axis lead screw 16 is connected to Z-axis slide 18 via a threaded connection. Driven by Z-axis servo motor 15, Z-axis slide 18 moves linearly along Z-axis guide rail 17. Z-axis frame 19 is mounted on Z-axis slide 18, and W-axis module 4 is mounted on Z-axis frame 19. Z-axis frame 19 reinforces and supports the structure of the entire Z-axis module 3, ensuring its rigidity and stability during machining.

[0026] In some embodiments, the speed reduction and torque amplification mechanism includes a drive pulley 20, a transmission belt 21, and a driven pulley 22. The drive pulley 20 is located at the drive end of the Z-axis servo motor 15, and the driven pulley 22 is located on the Z-axis lead screw 16. The transmission belt 21 is arranged between the drive pulley 20 and the driven pulley 22, and the diameter of the drive pulley 20 is smaller than the diameter of the driven pulley 22. This design achieves a speed reduction effect through belt transmission, enabling the high-speed rotation of the Z-axis servo motor to be converted into low-speed, high-torque rotation of the Z-axis lead screw. This meets the requirements of large EDM machine tools for Z-axis feed speed and accuracy during machining, achieves inertia matching between the motor and large moving parts, and meets the requirements for high torque and high inertia caused by the large lifting negative pressure due to the large area and narrow gap during large tool electrode discharge, thereby ensuring machining accuracy.

[0027] In some embodiments, the speed reduction and torque amplification mechanism may also be a gear reducer or a sprocket reducer.

[0028] In a specific embodiment of this application, to ensure the parallelism of the subsequent assembly of the W-axis module and the Z-axis module, the contact surfaces of the Z-axis frame 19 and the Z-axis slide 18 must be parallel to the contact surfaces of the Z-axis frame 19 and the W-axis base plate 5, i.e., they are mutually reference surfaces for precision grinding or precision milling. The right side of the W-axis base plate 5, as a reference surface, also needs to be precision ground, while ensuring its perpendicularity to the front and rear surfaces of the W-axis base plate 5. The assembly of the W-axis guide rail 9 and the W-axis lead screw 8 is based on the right side surface. The back of the W-axis base plate 5, through close contact with the Z-axis frame 19, constrains two degrees of freedom of the spatial attitude of the right side surface (i.e., pitch angle and yaw angle). The remaining degree of freedom, the roll angle, is precisely positioned by fine-tuning using locating pins and mounting screws provided on the W-axis base plate 5 and the Z-axis frame 19. In this way, the parallelism of the W-axis and Z-axis can be ensured by assembling with the right side surface of the W-axis base plate 5 as the reference surface.

[0029] In this invention, the terms "one embodiment," "some embodiments," "example," "specific example," and "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0030] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. An electrical discharge machining (EDM) machine tool, characterized in that, It includes an X-axis module, a Y-axis module, a Z-axis module, and a W-axis module. The Y-axis module is mounted on the drive end of the X-axis module, the Z-axis module is mounted on the drive end of the Y-axis module, and the W-axis module is mounted on the drive end of the Z-axis module. The Z-axis module and the W-axis module drive in the same direction. The Z-axis module includes a speed reduction and torque amplification mechanism. The W-axis module is a direct-drive motor structure. The dynamic response characteristics of the W-axis module are higher than those of the Z-axis module.

2. The electrical discharge machining tool according to claim 1, characterized in that, The W-axis module includes a moving part, which is made of a lightweight material.

3. The electrical discharge machining (EDM) machine tool according to claim 1, characterized in that, The W-axis module includes a W-axis base plate, a W-axis servo motor, a coupling, a W-axis lead screw, a W-axis guide rail, a W-axis slide, a W-axis frame, and a W-axis extension shaft. The W-axis base plate is disposed at the drive end of the Z-axis module. The W-axis servo motor, the coupling, and the W-axis guide rail are all disposed on the W-axis base plate. The drive end of the W-axis servo motor is connected to the W-axis lead screw via the coupling. The W-axis slide is slidably disposed on the W-axis guide rail. The W-axis lead screw is connected to the W-axis slide. The W-axis frame is disposed on the W-axis slide. The W-axis extension shaft is disposed at the bottom of the W-axis frame. Electrode assemblies are disposed on the W-axis extension shaft.

4. The electrical discharge machining tool according to claim 3, characterized in that, Both the W-axis substrate and the W-axis frame are made of aluminum alloy.

5. The electrical discharge machining tool according to claim 1, characterized in that, The W-axis extension shaft is made of polymer resin.

6. The electrical discharge machining tool according to claim 1, characterized in that, The Z-axis module includes a Z-axis mounting bracket, a Z-axis backplate, a Z-axis servo motor, a reduction and torque-increasing mechanism, a Z-axis lead screw, a Z-axis guide rail, a Z-axis slide, and a Z-axis frame. The Z-axis mounting bracket is disposed on the drive end of the Y-axis module. The Z-axis backplate is disposed on the Z-axis mounting bracket. The Z-axis servo motor is disposed on the Z-axis mounting bracket. The Z-axis guide rail is disposed on the Z-axis backplate. The Z-axis slide is slidably disposed on the Z-axis guide rail. The Z-axis servo motor is connected to the Z-axis lead screw through the reduction and torque-increasing mechanism. The Z-axis lead screw is connected to the Z-axis slide. The Z-axis frame is disposed on the Z-axis slide. The W-axis module is disposed on the Z-axis frame.

7. The electrical discharge machining tool according to claim 6, characterized in that, The speed reduction and torque amplification mechanism includes a drive pulley, a transmission belt, and a driven pulley. The drive pulley is located at the drive end of the Z-axis servo motor, and the driven pulley is located on the Z-axis lead screw. The transmission belt is located between the drive pulley and the driven pulley, and the diameter of the drive pulley is smaller than the diameter of the driven pulley.

8. The electrical discharge machining tool according to claim 6, characterized in that, The speed reduction and torque amplification mechanism is a gear reducer or a sprocket reducer.

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