Combined electrode double circuit electric spark efficient low-loss forming processing method, system and machine tool

Abstract

The application provides a combined electrode double-circuit electric spark efficient low-loss forming machining method, system and machine tool.The method comprises the following steps: arranging a combined electrode double-circuit before machining; simultaneously machining by using a double-pulse power double-circuit in the machining process; controlling electrode loss and machining efficiency in the machining process; and automatically cutting off short-circuit current in a poor machining state in the machining process.The machining system comprises a combined electrode double-circuit, a servo control system, a processor, a converter, a comparison ring and a gap ring.The implementation of each step in the method and the composition of each component of the system are closely related, closely combined and mutually influenced, and jointly provide corresponding assistance for overcoming the high-efficiency low-loss machining problem, thereby providing technical support for batch low-cost high-efficiency production and manufacturing of engine inlet titanium alloy protection grating mesh plates of similar aircrafts.

Description

Technical Field

[0001] This invention relates to the field of electrical discharge machining technology, specifically to a high-efficiency, low-loss forming machining method, system, and machine tool for dual-circuit combined electrode electrical discharge machining. It is particularly suitable for machining the group of oblique holes in the titanium alloy protective grid mesh plate of the engine air intake of shipborne aircraft, etc. It is a dedicated high-efficiency, low-loss electrical discharge machining technology and equipment for precision machining of critical protective components in aerospace applications. Background Technology

[0002] Electrical discharge machining (EDM) is a method of machining workpieces by means of pulsed electrical discharges between a tool electrode and the workpiece in a specific medium. The EDM performance of titanium alloys is quite unique, and the EDM performance of their cavities differs from that of carbon steel.

[0003] Machining multiple holes in titanium alloy materials is not only impossible by machining, but also extremely difficult by electrical discharge machining (EDM). The main difficulties lie in low efficiency and a high tendency for carbon buildup. When machining conductive materials with a 100A current, the pulse width of the pulse parameter is more than 10 times the machining current, i.e., ≥1000µs. When machining titanium alloy mesh using this parameter, both the electrode and the workpiece burn out, making normal machining impossible.

[0004] The air intake shields for shipborne aircraft engines are made of titanium alloy. As an important protective component, they are used repeatedly in large quantities. The manufacturing process of the complex structure holes (including rhomboid holes and rhomboid holes) on the shields is technically demanding and difficult to process. To date, no other process can mass-produce them. The mass production of such parts has been accomplished by electrical discharge machining (EDM) and its specialized equipment. With the continuous improvement of application technology requirements, even higher requirements have been placed on the EDM process for titanium alloy gratings.

[0005] In view of this, how to provide technical support for the mass production of multi-hole titanium alloy protective plates at low cost and high efficiency, and solve the problem of efficient and low-loss processing, has become the research content of this invention. Summary of the Invention

[0006] The purpose of this invention is to provide a method, system, and machine tool for high-efficiency, low-loss forming and machining of dual-circuit combined electrodes using electric discharge machining.

[0007] To achieve the above objectives, the first aspect of the present invention adopts the following technical solution: providing a high-efficiency, low-loss forming method for dual-circuit electrical discharge machining with combined electrodes, the method comprising: Before processing, a dual-circuit combination electrode is arranged. The first processing circuit is supplied with the first circuit pulse power supply to the first circuit processing area, and the second processing circuit is supplied with the second circuit pulse power supply to the second circuit processing area. The first circuit processing area and the second circuit processing area contain the workpiece to be processed and the processing electrode. The first processing circuit and the second processing circuit are controlled by the same servo control system, thereby forming a dual-circuit combination electrode. During the processing, a dual-pulse power supply is used for simultaneous processing in two circuits. The same servo control system controls the servo signals of the combined electrode dual circuits. A pulse energy with a large peak current and narrow pulse width is applied between the workpiece to be processed and the processing electrode in the first and second processing circuits. Controlling electrode wear and processing efficiency during processing: Inductor control is added to the first and second processing circuits respectively. By adjusting the inductance value, the current rising edge waveform of the pulse waveform is controlled to match the control electrode wear and processing efficiency. During the processing, the short-circuit current under undesirable processing conditions is automatically cut off. The status of the first and second processing circuits during the processing gap discharge period is statistically analyzed, and the short-circuit rate percentage is reasonably set. When the short-circuit rate reaches the set value, the processing current is automatically cut off, leaving only a small processing current for judging the processing status.

[0008] To achieve the above objectives, the technical solution adopted in the second aspect of the present invention is: to propose a combined electrode dual-circuit EDM high-efficiency low-loss forming machining system, the machining system being used to implement the combined electrode dual-circuit EDM high-efficiency low-loss forming machining method described in the first aspect of the present invention, the machining system comprising a combined electrode dual-circuit, a servo control system, a processor, a converter, a comparison loop, and a gap loop.

[0009] To achieve the above objectives, the technical solution adopted in the third aspect of the present invention is: to propose an electrical discharge machining (EDM) machine tool, wherein the EDM machine tool includes the combined electrode dual-circuit EDM high-efficiency and low-loss forming machining system described in the second aspect of the present invention.

[0010] The relevant content in the above technical solution is explained as follows: 1. In the technical solution of this invention, through research on the EDM machining of group oblique holes in titanium alloy protective grating plates similar to those used in the air intakes of shipborne aircraft engines, and in response to the applicant's need to provide technical support for the mass production of protective plates with group holes at low cost and high efficiency, the invention solves the problem of high-efficiency and low-loss machining. Therefore, the invention innovatively designs a combined electrode dual-circuit EDM high-efficiency and low-loss forming machining method, system, and machine tool. In the combined electrode dual-circuit EDM high-efficiency and low-loss forming machining method, a combined electrode dual-circuit is arranged before machining, and the first and second machining circuits are controlled by the same servo control system. This provides the equipment foundation for subsequent EDM machining, allowing the same servo control system to better collect, process, and control the signals and data from the first and second machining circuits during EDM machining, thereby providing optimal machining process parameters for the combined electrode dual-circuit. During the processing, efficient and low-loss processing is achieved through the organic combination of the following three steps: First, dual-pulse power supply is used for simultaneous processing in both circuits. The same servo control system controls the servo signals of the combined electrode dual circuits, applying pulse energy with a large peak current and narrow pulse width between the workpiece and the processing electrode. Second, inductor control is added to the first and second processing circuits respectively. By adjusting the inductance value, the current rising edge waveform of the pulse waveform is controlled to match the electrode wear and processing efficiency. Third, short-circuit current under poor processing conditions is automatically cut off. The state of the first and second processing circuits during the processing gap discharge is statistically analyzed, and the short-circuit rate percentage is reasonably set. When the short-circuit rate reaches the set value, the processing current is automatically cut off, leaving only a small processing current for judging the processing state.For the first step, a dual-pulse power supply machining circuit with single servo axis control and dual-loop machining mode is used, while high peak current and narrow pulse width are employed to achieve high-efficiency machining. For the second step, considering that the inductance value is inversely proportional to the rising edge slope of the pulse current waveform, the rising edge waveform of the pulse waveform is controlled by adjusting the inductance value. Since the rising edge slope angle of the current waveform is directly proportional to electrode wear and machining efficiency, adjusting the inductance value controls the rising edge waveform of the pulse waveform to match and control electrode wear and machining efficiency. This allows for better machining performance even when electrode wear is reduced using the first step. The process comprehensively considers both high processing efficiency and low electrode wear requirements. For the third step, by automatically cutting off the short-circuit current under unfavorable processing conditions during the processing, carbon buildup during electrical discharge machining can be avoided, thus preventing damage to the workpiece and electrodes. The implementation step involves statistically analyzing the state during the discharge interval between the first and second processing circuits. The processing states obtained by using dual-pulse power supply for simultaneous processing in the first step and by adding inductor control to the first and second processing circuits respectively in the second step are categorized and statistically analyzed to serve as the basis for automatically cutting off the short-circuit current under unfavorable processing conditions.

[0011] Therefore, the implementation of each step in the above method and the composition of each component of the system are closely related, closely integrated, and mutually influential, jointly providing corresponding assistance in overcoming the problem of efficient and low-damage processing, thereby providing technical support for the mass production of titanium alloy protective grating plates for engine air intakes of aircraft such as carrier-based aircraft at low cost and high efficiency.

[0012] In the first aspect of the above solution, the peak current is >200A; the pulse period of the narrow pulse is <100µs, and the pulse width of the narrow pulse is <40µs. Compared to other materials, the reason for using this pulse energy with a large peak current and narrow pulse width is to improve the processing efficiency of difficult-to-machine titanium alloys: the large peak current mainly improves the processing efficiency of titanium alloys, while the narrow pulse aims to reduce the probability of carbon buildup during the processing of this difficult-to-machine material. Therefore, using the above-mentioned reasonable pulse energy with a large peak current and narrow pulse width can maximize processing efficiency while ensuring stable processing.

[0013] In the first aspect of the solution described above, the inductance value ranges from 10μh to 200μh. The inductance value is inversely proportional to the slope of the rising edge waveform of the pulse current, and the slope angle of the rising edge waveform is controlled between 30° and 60°. The slope angle of the rising edge waveform is directly proportional to electrode loss and processing efficiency. The purpose of controlling the inductance value is to achieve an optimal trade-off between electrode loss and processing efficiency, minimizing electrode loss while maintaining high-efficiency processing. Therefore, selecting an inductance value range of 10μh to 200μh and controlling the slope angle of the rising edge waveform between 30° and 60° can meet different processing requirements.

[0014] 4. In the first aspect of the above solution, four sets of workpieces are processed simultaneously using four combined electrodes in a dual-circuit configuration. During the processing, to control electrode wear and processing efficiency, and prioritizing processing efficiency, the rising edge slope angle of the pulsed current waveform is controlled between 45° and 60°. The processing time is <210s, and the electrodes can be reused ≤5 times. The processing material is titanium alloy mesh; the hole diameter is 2.5mm*2.5mm, the material thickness H is 2mm, the hole tilt angle θ is 60°, and 2672 holes are processed simultaneously. This more specific processing technology maximizes processing efficiency while minimizing electrode wear.

[0015] 5. In the first aspect of the above solution, four sets of workpieces are processed simultaneously using four combined electrodes in a dual-circuit configuration. During the processing, to control electrode wear and processing efficiency, and prioritizing low wear, the rising edge slope angle of the pulsed current waveform is controlled between 30 and 45°. The processing time is >310 seconds, and the electrodes can be reused ≥25 times. The processing material is titanium alloy mesh; the hole diameter is 2.5mm*2.5mm, the material thickness H is 2mm, the hole inclination angle θ is 60°, and 2672 holes are processed simultaneously. This more specific processing technology maximizes the reduction of electrode wear while maintaining processing efficiency.

[0016] 6. In the above-mentioned first aspect of the solution, the process of controlling the servo signal of the combined electrode dual-loop by the servo control system includes the following steps: To address the gap voltage during the processing, a gap ring is used to proportionally reduce the gap voltage. The servo given voltage by the processor is compared with the servo input voltage via a comparison loop to generate a servo direction signal (DIR signal) and a comparison voltage. The comparison voltage is converted into a servo pulse signal (CP signal) by a converter, and then input into the processor along with the servo direction signal; The processor receives two sets of servo direction signals and servo pulse signals from the two loops. Following the principle of prioritizing backtracking, the processor processes and combines them into a single set of servo direction signals and servo pulse signals, which are then sent to the servo control system as servo drive signals. This enables servo control of the dual loops of the combined electrode through the movement of the machining axis.

[0017] The above steps are based on the use of dual-pulse power supply for simultaneous dual-circuit machining. Since the machining axis servo system for simultaneous dual-circuit machining control is shared, it is necessary to judge and process the two DIR / CP signals of the two circuits. For the servo direction signal DIR, the principle of backtracking priority is followed. For the CP signal, appropriate redundancy technology is adopted to ensure efficient and stable machining.

[0018] 7. In the solution of the first aspect above, the process of automatically cutting off the short-circuit current under poor processing conditions during the processing includes the following steps: The states of the first and second machining circuits during the discharge period in the machining gap are statistically analyzed and categorized based on the pulse waveform; The percentage of open circuits, discharges, and short circuits is calculated cyclically over a period of time, the duration of which is controlled by adaptive sensitivity. Set the short-circuit percentage short-circuit rate setting value. When the short-circuit percentage reaches the short-circuit rate setting value, the processing current is automatically cut off, and only a minimum processing current is retained to determine the processing status. When the processing status is restored, the previously set processing current is automatically reloaded and restored.

[0019] By implementing the above steps, short-circuit currents under adverse processing conditions are automatically cut off, ensuring no carbon buildup and no damage to the workpiece and electrodes.

[0020] 8. In the above-mentioned second aspect of the solution, the combined electrode dual circuit includes a first processing circuit and a second processing circuit. The first processing circuit is supplied with a first circuit pulse power supply to the first circuit processing area, and the second processing circuit is supplied with a second circuit pulse power supply to the second circuit processing area. The first circuit processing area and the second circuit processing area have a workpiece to be processed and a processing electrode. The first processing circuit and the second processing circuit are controlled by a servo control system.

[0021] The servo control system is used to control the servo signals of the combined electrode dual circuit, and to apply pulse energy with large peak current and narrow pulse waveform between the workpiece to be processed and the processing electrode in the first and second processing circuits.

[0022] The gap ring is used to proportionally reduce the gap voltage during the machining process.

[0023] The comparison loop is used to compare the proportionally reduced gap voltage with the servo given voltage by the processor to generate a servo direction signal and a comparison voltage.

[0024] The converter is used to convert the comparison voltage into a pulse signal.

[0025] The processor is used to acquire and process servo direction signals and pulse signals, and then issue servo drive signals, which are then controlled by the servo control system to control the servo signals of the combined electrode dual circuit.

[0026] The various components with specific functions described above are organically combined to form a complete and effective dual-circuit EDM high-efficiency low-loss forming and machining system, which can realize high-efficiency low-loss EDM machining of oblique holes in titanium alloy protective grating plates for engine air intakes of aircraft such as carrier-based aircraft.

[0027] 9. In the description of this application, it should be understood that the terms "upper", "lower", "vertical", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.

[0028] 10. In the above scheme, the terms "installation," "connection," "linking," and "fixing" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise explicitly defined. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0029] 11. In the above-described scheme, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0030] Due to the application of the above-mentioned solution, the present invention has the following advantages and effects compared with the prior art: 1. In the above-mentioned solution of the present invention, through research on the EDM machining of group oblique holes in titanium alloy protective grating plates for engine air intakes of aircraft such as carrier-based aircraft, and in response to the applicant's need to provide technical support for the mass production of protective plates with group holes at low cost and high efficiency, the present invention innovatively designs a combined electrode dual-circuit EDM high-efficiency low-loss forming machining method, system, and machine tool. In the combined electrode dual-circuit EDM high-efficiency low-loss forming machining method, a combined electrode dual-circuit is arranged before machining, and the first machining circuit and the second machining circuit are controlled by the same servo control system. This provides the equipment foundation for subsequent EDM machining, and allows the same servo control system to better collect, process, and control the signals and data of the first and second machining circuits during EDM machining, thereby providing the optimal machining process parameters for the combined electrode dual-circuit.

[0031] 2. In the above-mentioned solution of the present invention, high-efficiency and low-loss processing is achieved through the organic combination of the following three steps: First, dual-pulse power supply is used for simultaneous processing in dual circuits. The same servo control system controls the servo signals of the dual circuits of the combined electrodes, applying pulse energy with a large peak current and narrow pulse width between the workpiece to be processed and the processing electrode; Second, inductor control is added to the first and second processing circuits respectively. The current rising edge waveform of the pulse waveform is controlled by adjusting the inductance value to match the electrode wear and processing efficiency; Third, short-circuit current under poor processing conditions is automatically cut off. The state during the discharge period of the processing gap between the first and second processing circuits is statistically analyzed, and the percentage of short-circuit rate is reasonably set. When the short-circuit rate reaches the set value, the processing current is automatically cut off, leaving only a small processing current for judging the processing state.

[0032] 3. In summary, the implementation of each step in the method of this invention and the composition of each component of the system are closely related, interdependent, and mutually influential. From the perspective of electrical discharge machining (EDM), the main discharge process parameters are analyzed, the process rules are summarized, and the optimal processing parameters are obtained. Combined with the development of process control methods and the manufacturing of specialized process equipment, efficient and low-loss machining is achieved. Therefore, this invention has outstanding substantive features and significant progress, and together they provide corresponding assistance in overcoming the problem of efficient and low-loss machining, thereby providing technical support for the mass production of low-cost and high-efficiency titanium alloy protective grating plates for engine air intakes of aircraft such as carrier-based aircraft. Attached Figure Description

[0033] Figure 1 This is a schematic flowchart of the high-efficiency, low-loss forming process of the dual-circuit EDM with combined electrodes according to an embodiment of the present invention. Figure 2 This is a schematic diagram of the combined electrode dual circuit arranged in an embodiment of the present invention; Figure 3This is a schematic diagram of the combined electrode dual-circuit EDM high-efficiency low-loss forming process according to an embodiment of the present invention; Figure 4 This is a circuit diagram of the dual-loop combined electrode in an embodiment of the present invention.

[0034] In the attached diagrams above: 1. Combined Electrode Dual Circuit 11 First processing circuit 111 First Circuit Pulse Power Supply 112 First Circuit Processing Area 12 Second processing circuit 121 Second Circuit Pulse Power Supply 122 Second Circuit Processing Area 2 Servo Control System 3 processors 4. Converter 5. Comparison ring 6. Gap ring. Detailed Implementation

[0035] To make the above-mentioned objectives, features, and advantages of this application more apparent and understandable, the specific embodiments of this application are described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a thorough understanding of this application. However, this application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of this application. Therefore, this application is not limited to the specific embodiments disclosed below.

[0036] This invention aims to solve the problem of high-efficiency and low-loss machining by using the research on the electro-discharge machining of group oblique holes in titanium alloy protective grating plates for engine air intakes of aircraft such as carrier-based aircraft, and to provide technical support for the mass production of protective plates with group holes at low cost and high efficiency. The invention has innovatively designed a combined electrode dual-circuit 1 electro-discharge high-efficiency and low-loss forming machining method, system and machine tool.

[0037] The following detailed description will be provided with specific examples.

[0038] Example 1: As Figure 1 As shown, Embodiment 1 of the present invention proposes a high-efficiency, low-loss EDM forming method with a combined electrode dual-circuit 1, the method comprising: Before processing, a combined electrode dual-loop 1 is arranged. The first processing loop 11 is supplied to the first processing area 112 by the first loop pulse power supply 111, and the second processing loop 12 is supplied to the second processing area 122 by the second loop pulse power supply 121. The first processing area 112 and the second processing area 122 contain the workpiece to be processed and the processing electrodes. The first processing loop 11 and the second processing loop 12 are controlled by the same servo control system 2, thereby forming the combined electrode dual-loop 1. The arrangement of the combined electrode dual-loop 1 can be referenced. Figure 2 As shown; During the processing, a dual-pulse power supply is used for simultaneous processing in two circuits. The same servo control system 2 controls the servo signal of the combined electrode dual circuit 1. A pulse energy with a large peak current and narrow pulse width is applied between the workpiece to be processed and the processing electrode in the first processing circuit 11 and the second processing circuit 12. During the processing, electrode wear and processing efficiency are controlled by adding inductor control to the first processing circuit 11 and the second processing circuit 12 respectively. The current rising edge waveform of the pulse waveform is controlled by adjusting the inductor value to match the control of electrode wear and processing efficiency. During the processing, the short-circuit current under undesirable processing conditions is automatically cut off. The state of the first processing circuit 11 and the second processing circuit 12 during the processing gap discharge is statistically analyzed, and the percentage of short-circuit rate is reasonably set. When the short-circuit rate reaches the set value, the processing current is automatically cut off, and only a small processing current is retained to judge the processing state.

[0039] In the combined electrode dual-loop 1 high-efficiency low-loss forming process of the present invention, the combined electrode dual-loop 1 is arranged before processing, and the first processing loop 11 and the second processing loop 12 are controlled by the same servo control system 2. This provides the equipment foundation for subsequent EDM processing, and allows the same servo control system 2 to better collect, process and control the signals and data of the first processing loop 11 and the second processing loop 12 during EDM processing, thereby providing the best processing parameters for the combined electrode dual-loop 1.

[0040] The following three steps are organically combined during the processing to achieve efficient and low-damage processing: The first method uses a dual-pulse power supply for simultaneous processing in both circuits. The same servo control system 2 controls the servo signal of the combined electrode dual circuit 1, applying pulse energy with a large peak current and narrow pulse width to the workpiece and the processing electrode.

[0041] The second method involves adding inductor control to the first processing circuit 11 and the second processing circuit 12 respectively. By adjusting the inductance value, the current rising edge waveform of the pulse waveform is controlled to match the control electrode wear and processing efficiency.

[0042] The third is to automatically cut off the short-circuit current under poor processing conditions. The state of the first processing circuit 11 and the second processing circuit 12 during the processing gap discharge is statistically analyzed, and the percentage of short-circuit rate is reasonably set. When the short-circuit rate reaches the set value, the processing current is automatically cut off, and only a small processing current is retained to judge the processing state.

[0043] For the first step, a dual-pulse power supply is used to control the dual-loop machining mode with a single servo axis, while high peak current and narrow pulse width are adopted to achieve efficient machining.

[0044] For the second step, considering that the inductance value is inversely proportional to the rising edge slope of the pulse current waveform, the current rising edge of the pulse waveform can be controlled by adjusting the selected inductance value. The slope angle of the current rising edge waveform is directly proportional to the electrode loss and the processing efficiency. Therefore, by adjusting the inductance value, the current rising edge waveform of the pulse waveform can be controlled to match the control of electrode loss and processing efficiency. Thus, even when the electrode loss is reduced by using the first step, it is still possible to comprehensively consider the processing requirements of high processing efficiency and low loss for different processing conditions.

[0045] For the third step, by automatically cutting off the short-circuit current under undesirable machining conditions during the machining process, carbon buildup during electrical discharge machining can be further avoided, thus preventing damage to the workpiece and electrodes. The implementation step is to statistically analyze the state during the discharge of the machining gap between the first machining circuit 11 and the second machining circuit 12. The states obtained by using dual-pulse power supply for simultaneous machining in the first step and by adding inductor control to the first machining circuit 11 and the second machining circuit 12 in the second step are categorized and statistically analyzed to serve as the basis for automatically cutting off the short-circuit current under undesirable machining conditions.

[0046] Therefore, the implementation of each step in the above method and the composition of each component of the system are closely related, closely integrated, and mutually influential, jointly providing corresponding assistance in overcoming the problem of efficient and low-damage processing, thereby providing technical support for the mass production of titanium alloy protective grating plates for engine air intakes of aircraft such as carrier-based aircraft at low cost and high efficiency.

[0047] For titanium alloy protective grating plates for engine air intakes of aircraft such as carrier-based aircraft, the different processing requirements can be roughly divided into two categories: those that prioritize processing efficiency and those that prioritize low loss.

[0048] This system uses a dual-circuit, four-electrode configuration to simultaneously process four sets of workpieces. During processing, to balance electrode wear and efficiency, and prioritizing efficiency, the pulse current waveform rise slope angle is controlled between 45° and 60°. Processing time is less than 210 seconds, and the electrodes can be reused ≤5 times. The processing material is titanium alloy mesh; the aperture is 2.5mm x 2.5mm, and the material thickness H is 2mm. The hole tilt angle θ is 60°, and 2672 holes are processed simultaneously. This more specific processing technique maximizes efficiency while minimizing electrode wear.

[0049] This process utilizes a dual-circuit four-electrode combination to simultaneously process four sets of workpieces. During processing, to control electrode wear and efficiency, and prioritizing low wear, the pulse current waveform rise edge slope angle is controlled between 30 and 45°. The processing time is >310 seconds, and the electrodes can be reused ≥25 times. The processing material is titanium alloy mesh; the aperture is 2.5mm x 2.5mm, and the material thickness H is 2mm. The hole tilt angle θ is 60°, and 2672 holes are processed simultaneously. This more specific processing technology maximizes electrode wear reduction while maintaining processing efficiency.

[0050] In one embodiment of the present invention, the peak current is >200A; the pulse period of the narrow pulse is <100µs, and the pulse width of the narrow pulse is <40µs. Compared to other materials, the reason for using this pulse energy with a large peak current and narrow pulse width is to improve the processing efficiency of difficult-to-machine titanium alloys: the large peak current mainly improves the processing efficiency of titanium alloys, while the narrow pulse aims to reduce the probability of carbon buildup during the processing of this difficult-to-machine material. Therefore, using the above-mentioned reasonable pulse energy with a large peak current and narrow pulse width can maximize processing efficiency while ensuring stable processing. An optimal trade-off can be made between electrode wear and processing time, achieving high processing efficiency while minimizing electrode wear.

[0051] In another embodiment of the present invention, the inductance value ranges from 10μh to 200μh. The inductance value is inversely proportional to the slope of the current rising edge waveform, and the slope angle of the current rising edge waveform is controlled between 30° and 60°. The slope angle of the current rising edge waveform is directly proportional to electrode loss and processing efficiency. A balance is sought between electrode loss and processing time; therefore, selecting an inductance value range of 10μh to 200μh and controlling the slope angle of the current rising edge waveform between 30° and 60° can meet different processing requirements.

[0052] In another embodiment of the first embodiment of the present invention, reference can be made to Figure 3As shown, the process of controlling the servo signal of the combined electrode dual-loop 1 by the servo control system 2 includes the following steps: The gap voltage during the processing is reduced proportionally by the gap ring 6; The servo given voltage from processor 3 is compared with the servo given voltage by comparison loop 5 to generate a servo direction signal (DIR signal) and a comparison voltage; The comparison voltage is converted into a servo pulse signal (CP signal) by converter 4, and input to processor 3 together with the servo direction signal; Processor 3 receives two sets of servo direction signals and servo pulse signals from the two loops. Following the principle of prioritizing backtracking, it processes and combines them into a set of servo direction signals and servo pulse signals, which are then sent to servo control system 2 as servo drive signals. The movement of the machining axis enables servo control of the combined electrode dual loop 1.

[0053] The implementation of the above steps is based on the simultaneous machining of two circuits using a dual-pulse power supply. Since the machining axis servo system controlled by the simultaneous machining of two circuits is shared, it is necessary to judge and process the two DIR / CP signals of the two circuits. For the servo direction signal DIR, the principle of backtracking priority is followed. For the CP signal, appropriate redundancy technology is adopted to ensure efficient and stable machining.

[0054] In one embodiment of the present invention, the process of automatically cutting off short-circuit current under defective processing conditions during the processing includes the following steps: The states of the first machining circuit 11 and the second machining circuit 12 during the discharge period in the machining gap are statistically classified according to the pulse waveform; The percentage of open circuits, discharges, and short circuits is calculated cyclically over a period of time, the duration of which is controlled by adaptive sensitivity. Set the short-circuit percentage short-circuit rate setting value. When the short-circuit percentage reaches the short-circuit rate setting value, the processing current is automatically cut off, and only a minimum processing current is retained to determine the processing status. When the processing status is restored, the previously set processing current is automatically reloaded and restored.

[0055] By implementing the above steps, short-circuit currents under adverse processing conditions are automatically cut off, ensuring no carbon buildup and no damage to the workpiece and electrodes.

[0056] Example 2: This invention proposes a combined electrode dual-loop 1 EDM high-efficiency low-loss forming machining system. The machining system is used to implement the combined electrode dual-loop 1 EDM high-efficiency low-loss forming machining method described in Example 1 of this invention. The machining system includes a combined electrode dual-loop 1, a servo control system 2, a processor 3, a converter 4, a comparison ring 5, and a gap ring 6.

[0057] In Embodiment 2 of the present invention, as Figure 2 As shown, the combined electrode dual-loop 1 includes a first processing loop 11 and a second processing loop 12. The first processing loop 11 is supplied to the first processing area 112 by a first loop pulse power supply 111, and the second processing loop 12 is supplied to the second processing area 122 by a second loop pulse power supply 121. The first processing area 112 and the second processing area 122 contain workpieces to be processed and processing electrodes, respectively. The first processing loop 11 and the second processing loop 12 are controlled by a servo control system 2. A circuit diagram of the combined electrode dual-loop 1 can be found in [reference needed]. Figure 4 As shown.

[0058] The servo control system 2 is used to control the servo signal of the combined electrode dual circuit 1, and to apply pulse energy with large peak current and narrow pulse waveform between the workpiece to be processed and the processing electrode in the first processing circuit 11 and the second processing circuit 12.

[0059] The gap ring 6 is used to proportionally reduce the gap voltage during the processing.

[0060] The comparison ring 5 is used to compare the proportionally reduced gap voltage with the servo given voltage provided by the processor 3 to generate a servo direction signal and a comparison voltage.

[0061] The converter 4 is used to convert the comparison voltage into a pulse signal.

[0062] The processor 3 is used to acquire and process servo direction signals and pulse signals, and then issue servo drive signals, which are then controlled by the servo control system 2 to control the servo signals of the combined electrode dual circuit 1.

[0063] The various components and functions described above are organically combined to form a complete and effective combined electrode dual-circuit EDM high-efficiency low-loss forming and processing system, which can realize high-efficiency and low-loss EDM processing of group oblique holes for titanium alloy protective grating plates for engine air intakes of aircraft such as carrier-based aircraft.

[0064] Example 3: This invention proposes an electrical discharge machining (EDM) machine tool, which includes the combined electrode dual-circuit 1 EDM high-efficiency low-loss forming system described in Example 2 of this invention. The components are not described in detail here.

[0065] The following section will introduce the specific implementation process and some process adjustments and selections made during the electrical discharge machining process.

[0066] This invention employs a dual-pulse power supply machining circuit with single-servo axis control in a dual-loop machining mode, while utilizing high peak current and narrow pulse waveforms to achieve efficient and low-loss machining. Specifically: peak current > 200A; pulse period < 100µs; pulse width < 40µs.

[0067] By inserting an inductor in the machining circuit, with an inductance value ranging from 10μh to 200μh, the inductance value is inversely proportional to the rise edge slope of the pulse waveform. By adjusting the inductance value to match the current rise edge of the pulse waveform, the current rise edge control is achieved. For different machining requirements, the slope angle of the current rise edge waveform is controlled between 30° and 60°. The slope angle of the current rise edge waveform is directly proportional to the electrode loss and machining efficiency.

[0068] If both high processing efficiency and low loss processing requirements are considered, then controlling the rising edge slope angle of the pulse current waveform to 45° can achieve a comprehensive processing time of <270s, and the electrode can be reused 20 times.

[0069] For situations where a single performance indicator (high efficiency or low loss) is emphasized, but the processing requirements can still be met: If processing efficiency is the priority, the slope angle of the rising edge of the pulse waveform should be controlled between 45° and 60°. A larger slope results in higher processing efficiency, but also greater electrode wear. Processing time can be controlled to <210s, and the electrode can be reused <5 times. However, as the number of reuses increases, the hole shape of the oblique hole processing deteriorates. If the focus is on low loss, then the slope angle of the rising edge of the pulse waveform is controlled between 30° and 45°. A small slope results in low electrode wear, but low processing efficiency and a processing time of >310s. The electrode can be reused up to 25 times, and the edges of the processed hole are clear.

[0070] The control of the servo signals of the combined electrode dual-loop 1 by the same servo control system 2 is further explained as follows: This case uses a dual-loop servo signal processing method (single servo axis control).

[0071] During the machining process, the gap voltage is reduced to 0-12V via gap ring 6. This voltage is then compared with the servo setpoint voltage provided by the computer via comparison ring 5, generating a servo direction signal DIR and a comparison voltage V. The comparison voltage V is converted into a frequency signal F (pulse signal CP) by V / F converter 4. This signal, along with the direction signal DIR, is sent to the long-line receiver input of the computer interface card via a long-line driver, and then transmitted to the computer bus via optocoupler isolation. The computer processes the received signal and issues the DIR / CP signal to the servo drive system to control the servo motor.

[0072] Because this invention features two machining loops operating simultaneously, but the controlled machining axis servo system is shared, it is necessary to process the two DIR / CP signals of the two loops. For the direction signal DIR, a backtracking priority is applied, while for the CP signal, appropriate redundancy techniques are employed to ensure efficient and stable machining.

[0073] The steps for automatically cutting off short-circuit current under undesirable processing conditions are explained in more detail below: The system features power supply adaptation control and macroscopic statistical analysis of the percentage of short-circuit current. Based on software settings ranging from 1% to 100%, it automatically cuts off short-circuit current under adverse processing conditions, ensuring no carbon buildup and no damage to the workpiece and electrodes.

[0074] The states of the two circuits during the discharge period of the processing gap are statistically analyzed in categories (based on the actual waveform). The percentage of open circuit, discharge and short circuit within a certain period of time is calculated cyclically. The duration is controlled by the adaptive sensitivity (0-15, equivalent to a gear). The sensitivity corresponds to the time (0 corresponds to 800ms, 15 corresponds to 50ms). When the short circuit rate reaches the software set value, the processing current is automatically cut off, and only the minimum processing current value is retained to judge the processing status. When the processing status is restored, the previously set processing current is automatically loaded and restored.

[0075] Through the implementation of the above embodiments, the present invention achieves the goal of efficient and low-damage processing, providing technical support for the mass production of titanium alloy protective grating plates for engine air intakes of aircraft such as carrier-based aircraft at low cost and high efficiency.

[0076] The above embodiments are only for illustrating the technical concept and features of the present invention, and are intended to enable those skilled in the art to understand the content of the present invention and implement it accordingly. They should not be construed as limiting the scope of protection of the present invention. All equivalent changes or modifications made in accordance with the spirit and essence of the present invention should be covered within the scope of protection of the present invention.

Claims

1. A high-efficiency, low-loss forming method for dual-circuit EDM with combined electrodes, characterized in that, The method includes: Before processing, a dual-circuit combination electrode is arranged. The first processing circuit is supplied with the first circuit pulse power supply to the first circuit processing area, and the second processing circuit is supplied with the second circuit pulse power supply to the second circuit processing area. The first circuit processing area and the second circuit processing area contain the workpiece to be processed and the processing electrode. The first processing circuit and the second processing circuit are controlled by the same servo control system, thereby forming a dual-circuit combination electrode. During the processing, a dual-pulse power supply is used for simultaneous processing in two circuits. The same servo control system controls the servo signals of the combined electrode dual circuits. A pulse energy with a large peak current and narrow pulse width is applied between the workpiece to be processed and the processing electrode in the first and second processing circuits. During the processing, electrode wear and processing efficiency are controlled by adding inductor control to the first and second processing circuits respectively. The current rising edge waveform of the pulse waveform is controlled by adjusting the inductor value to match the control of electrode wear and processing efficiency. During the processing, the short-circuit current under undesirable processing conditions is automatically cut off. The status of the first and second processing circuits during the processing gap discharge period is statistically analyzed, and the short-circuit rate percentage is reasonably set. When the short-circuit rate reaches the set value, the processing current is automatically cut off, leaving only a small processing current for judging the processing status.

2. The high-efficiency, low-loss forming method for dual-circuit EDM with combined electrodes according to claim 1, characterized in that: The peak current is greater than 200A; the pulse period of the narrow pulse is less than 100µs, and the pulse width of the narrow pulse is less than 40µs.

3. The high-efficiency, low-loss forming method for dual-circuit EDM with combined electrodes according to claim 1, characterized in that: The inductance value ranges from 10μh to 200μh. The inductance value is inversely proportional to the slope of the current rising edge waveform of the pulse. The slope angle of the current rising edge waveform is controlled between 30° and 60°.

4. The high-efficiency, low-loss forming method for dual-circuit EDM with combined electrodes according to claim 1, characterized in that: The dual-circuit four-electrode combination processes four sets of workpieces simultaneously. During the processing, the electrode wear and processing efficiency are controlled. For cases where processing efficiency is the priority, the slope angle of the pulse current rise edge waveform is controlled between 45 and 60°. The processing time is <210s, and the electrodes can be reused ≤5 times. The processing material is titanium alloy mesh; the hole diameter is 2.5mm*2.5mm, the material thickness H is 2mm, the hole tilt angle θ is 60°, and 2672 holes are processed simultaneously.

5. The high-efficiency, low-loss forming method for dual-circuit EDM with combined electrodes according to claim 1, characterized in that: The dual-circuit four-electrode combination processes four sets of workpieces simultaneously. During the processing, the electrode wear and processing efficiency are controlled. For the case where low wear is required, the slope angle of the pulse current rise edge waveform is controlled between 30 and 45°. The processing time is >310s. The electrodes can be reused ≥25 times. The processing material is titanium alloy mesh plate. The hole diameter is 2.5mm*2.5mm. The material thickness H is 2mm. The hole tilt angle θ is 60°. The number of holes processed simultaneously is 2672.

6. The high-efficiency, low-loss forming method for dual-circuit EDM with combined electrodes according to claim 1, characterized in that: The process of controlling the servo signals of the combined electrode dual-loop by the servo control system includes the following steps: To address the gap voltage during the processing, a gap ring is used to proportionally reduce the gap voltage. The servo given voltage by the processor is compared with the servo input voltage via a comparison loop to generate a servo direction signal and a comparison voltage; The comparison voltage is converted into a servo pulse signal by a converter, and then input into the processor along with the servo direction signal. The processor receives two sets of servo direction signals and servo pulse signals from the two loops. Following the principle of prioritizing backtracking, the processor processes and combines them into a single set of servo direction signals and servo pulse signals, which are then sent to the servo control system as servo drive signals. This enables servo control of the dual loops of the combined electrode through the movement of the machining axis.

7. The high-efficiency, low-loss forming method for dual-circuit EDM with combined electrodes according to claim 1, characterized in that: The process of automatically cutting off short-circuit current under defective processing conditions during the processing includes the following steps: The states of the first and second machining circuits during the discharge period in the machining gap are statistically analyzed and categorized based on the pulse waveform; The percentage of open circuits, discharges, and short circuits is calculated cyclically over a period of time, the duration of which is controlled by adaptive sensitivity. Set the short-circuit percentage short-circuit rate setting value. When the short-circuit percentage reaches the short-circuit rate setting value, the processing current is automatically cut off, and only a minimum processing current is retained to determine the processing status. When the processing status is restored, the previously set processing current is automatically reloaded and restored.

8. A high-efficiency, low-loss forming system for dual-circuit combined electrode electrical discharge machining, characterized in that: The machining system is used to implement the combined electrode dual-loop EDM high-efficiency low-loss forming machining method as described in any one of claims 1 to 7. The machining system includes a combined electrode dual-loop, a servo control system, a processor, a converter, a comparison ring, and a gap ring.

9. The combined electrode dual-circuit EDM high-efficiency low-loss forming system according to claim 8, characterized in that: The combined electrode dual circuit includes a first processing circuit and a second processing circuit. The first processing circuit is supplied with a first circuit pulse power supply to the first circuit processing area, and the second processing circuit is supplied with a second circuit pulse power supply to the second circuit processing area. The first circuit processing area and the second circuit processing area contain workpieces to be processed and processing electrodes. The first processing circuit and the second processing circuit are controlled by a servo control system. The servo control system is used to control the servo signals of the combined electrode dual circuit, and to apply pulse energy with large peak current and narrow pulse waveform between the workpiece to be processed and the processing electrode in the first processing circuit and the second processing circuit. The gap ring is used to proportionally reduce the gap voltage during the processing; The comparison loop is used to compare the proportionally reduced gap voltage with the servo given voltage by the processor to generate a servo direction signal and a comparison voltage. The converter is used to convert the comparison voltage into a pulse signal. The processor is used to acquire and process servo direction signals and pulse signals, and then issue servo drive signals, which are then controlled by the servo control system to control the servo signals of the combined electrode dual circuit.

10. An electrical discharge machining (EDM) machine tool, characterized in that: The electrical discharge machining (EDM) machine tool includes the dual-circuit EDM high-efficiency low-loss forming system with combined electrodes as described in claim 8 or 9.

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