Deep hole electric discharge machining method

Abstract

The invention discloses a deep hole electric discharge machining method, and relates to the technical field of electric discharge machines. In order to solve the problem that an existing discharge machining method lacks deep hole machining for materials difficult to machine, the following technical scheme is provided: S1, positioning and clamping; s2, mounting and positioning a workpiece; s3, starting a working solution circulating system; s4, starting a pulse power supply and adjusting parameters; and S5, electric discharge machining is executed. According to the invention, high-precision, high-efficiency and high-stability control of the deep hole machining process is realized through accurate positioning and clamping, effective working solution circulation, accurate pulse power supply control and detailed pretreatment and inspection and maintenance measures. Due to the beneficial effects, the scheme has wide application prospects and important economic value in the deep hole machining field of difficult-to-machine materials.

Description

Technical Field

[0001] The invention relates to the technical field of electric discharge machining, and in particular to a deep hole electric discharge machining method. Background Art

[0002] Deep hole processing technology has always been an important field in the manufacturing industry, especially in the fields of aerospace, automobile manufacturing and precision machinery, where the requirements for deep hole processing are becoming increasingly stringent. However, when facing difficult-to-process materials, such as high-strength and high-hardness materials such as cemented carbide and titanium alloy, traditional deep hole processing methods often face technical difficulties such as low efficiency, severe tool wear, and difficulty in ensuring processing accuracy.

[0003] These technical problems are mainly reflected in the easy wear of tools, easy deformation of workpieces, and poor surface quality during processing. In addition, due to the particularity of deep hole processing, the heat and debris generated during processing are difficult to be effectively discharged, further aggravating tool loss and unstable processing quality. Therefore, how to effectively solve the technical problems in deep hole processing and improve processing efficiency and processing quality has become an important issue that needs to be solved in the current manufacturing industry. Summary of the invention

[0004] The object of the present invention is to provide a deep hole electrical discharge machining method to solve the problem that the existing machining methods lack the deep hole machining for difficult-to-machine materials.

[0005] The technical solution of the present invention to solve the above technical problems is as follows: A deep hole electrical discharge machining method comprises the following steps: S1. Positioning and clamping: Use the triangular chuck of the lathe spindle to clamp the tool connection sleeve, keep the lathe spindle still, and at the same time, tighten the drill electrode tool and the tool connection sleeve through the insulating connecting pin, adjust the slide box to position the specific axial position of the clamp, and ensure that the tool head of the drill electrode tool is located in the middle of the filter joint; S2. Workpiece installation and positioning: Place the workpiece in the through hole of the positioning plate, use the axial clamping frame to adjust the position of the clamp body, align the workpiece surface to be processed with the filter joint, and radially tighten the workpiece through the clamping ring and the positioning plate to prevent it from jumping; S3, start the working fluid circulation system: start the system, inject the high-pressure working fluid from the working fluid injection ring and the filter joint, flow into the processing surface through the through hole of the trepanning drill electrode tool, and flow back from the inner cavity of the tool and the gap between the core; S4, start pulse power supply and adjust parameters: start pulse power supply, adjust peak current, pulse width and pulse interval to preset range, and set axial feed speed, forward feed time and reverse feed time of the clamp; S5. Execute discharge machining: When the power is on, start the axial feed of the clamp body, first perform forward feed processing, and then reverse feed for a period of time until the deep hole processing of the entire workpiece is completed.

[0006] Preferably, in step S2, the workpiece installation and positioning further includes: accurately adjusting the position of the workpiece by an axial clamping frame to ensure that the surface to be processed is accurately located in the middle of the filter joint; adjusting the relative position between the clamping ring and the positioning plate to achieve radial tightening of the workpiece to prevent radial movement or jumping of the workpiece during processing; using clamping bolts to firmly fit the axial clamping frame to the end face of the workpiece to ensure the axial stability of the workpiece.

[0007] Preferably, in step S3, the starting working fluid circulation system further includes: ensuring that the pressure of the high-pressure working fluid is 0.5 MPa; after the working fluid is injected from the working fluid injection ring and the filter joint, it flows evenly through the through hole of the drilling electrode tool to effectively cool the processing surface; the heat and debris generated by the processing are effectively discharged through the inner cavity of the drilling electrode tool and the gap between the core, and flow back into the working fluid recovery system.

[0008] Preferably, in step S4, the starting pulse power supply and adjustment parameters further include: the adjustment range of the peak current is 1-20A; the adjustment range of the pulse width is 100μs-500μs; the adjustment range of the pulse interval is 100μs-500μs; the axial feed speed of the clamp is set to 0.1-0.8mm / min, the forward feed time is set to 5-10min, and the reverse feed time is set to 1-3min.

[0009] Preferably, before performing the discharge machining in step S5, the process also includes: pre-inspecting the tool connecting sleeve, the drill electrode tool, the insulating connecting pin and the clamp body to ensure that they are intact and fit tightly; pre-treating the workpiece to remove surface impurities to ensure the cleanliness of the machined surface.

[0010] Preferably, during the discharge machining process performed in step S5, the process also includes: real-time monitoring of current and voltage waveform changes during the machining process; real-time adjustment of the feed speed of the clamp according to the monitoring data to ensure the stability of the discharge machining; regular inspection and replacement of worn electrodes during the machining process to ensure machining quality and efficiency. The present invention has the following beneficial effects: This solution ensures the stability and accuracy of the workpiece and tool during the machining process through precise positioning, clamping, workpiece installation and positioning steps. The tool connection sleeve is clamped by the triangular chuck of the lathe spindle, and the drill electrode tool is fastened to the tool connection sleeve through the insulating connecting pin, which effectively prevents the tool from loosening and offsetting during the machining process. At the same time, the precise positioning and radial fastening of the workpiece are achieved through the cooperation of the axial clamping frame and the clamping ring with the positioning plate, which prevents the workpiece from jumping and moving radially during the machining process. The axis accuracy and surface quality of the machined hole are guaranteed.

[0011] Secondly, by starting the working fluid circulation system, effective cooling and chip removal of the machined surface is achieved. After the high-pressure working fluid is injected from the working fluid injection ring and the filter joint, it flows evenly through the through hole of the trepanning drill electrode tool, effectively removing the heat and debris generated during the machining process. These heat and debris are discharged through the inner cavity of the trepanning drill electrode tool and the gap between the core, and flow back into the working fluid recovery system. This step not only ensures the stability of the machining process, but also extends the service life of the tool and improves machining efficiency.

[0012] In addition, by starting the pulse power supply and accurately adjusting the parameters, precise control of the EDM process is achieved. The precise adjustment of the peak current, pulse width and pulse interval, as well as the reasonable setting of the clamp body axial feed speed, forward feed time and reverse feed time, jointly determine the energy size and distribution of the EDM, thus affecting the machining efficiency and surface quality. By real-time monitoring of the current and voltage waveform changes during the machining process and adjusting the clamp body feed speed in real time according to the monitoring data, the stability of the EDM can be ensured, and the machining quality and efficiency can be further improved.

[0013] Finally, the solution also focuses on the pretreatment of tools and workpieces, as well as regular inspection and maintenance during the machining process. Pre-inspect tool sleeves, drill electrode tools, insulating connecting pins, and clamp bodies to ensure they are intact and fit tightly; pre-treat workpieces to remove surface impurities and ensure the cleanliness of the machined surface. These measures help reduce the failure rate and loss rate during machining, and improve machining efficiency and economic benefits. At the same time, regular inspection and replacement of worn electrodes during machining can ensure the stability and consistency of machining quality. DETAILED DESCRIPTION

[0014] The technical solution of the present invention is described clearly and completely below. Obviously, the described embodiments are only a part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present invention.

[0015] The present invention relates to an efficient and precise deep hole processing technology, which is particularly suitable for deep hole processing of difficult-to-process materials such as cemented carbide and titanium alloy. The method achieves high-quality deep hole processing by combining precise positioning and clamping technology, efficient working fluid circulation system and precise pulse power supply control. The following is a specific implementation of the present invention: First, the positioning and clamping step (S1) is performed. In this step, the tool connection sleeve is clamped using the triangular chuck of the lathe spindle to ensure the stability and accuracy of the tool connection sleeve during the processing. The lathe spindle remains stationary to ensure that no additional errors are introduced due to the rotation of the spindle during the processing. At the same time, the drill electrode tool is fastened to the tool connection sleeve through the insulating connecting pin. The use of the insulating connecting pin not only ensures a firm connection between the tool and the connection sleeve, but also ensures electrical insulation to prevent the processing effect from being affected by current leakage. Next, the slide box is adjusted to accurately locate the axial position of the clamp to ensure that the tool head of the drill electrode tool is accurately located in the middle of the filter joint. This step is crucial to the accuracy of subsequent processing, because the position of the tool head will directly affect the axis accuracy and surface quality of the processed hole.

[0016] Next, the workpiece installation and positioning step (S2) is entered. In this step, the workpiece is first placed in the through hole of the positioning plate. The design of the positioning plate ensures the stability and accuracy of the workpiece during the installation process. Then, the position of the clamp body is accurately adjusted using the axial jacking frame so that the workpiece surface to be processed is accurately aligned with the filter joint. In this step, the use of the axial jacking frame not only ensures the precise positioning of the workpiece in the axial direction, but also achieves fine-tuning of the workpiece position through its adjustment function, ensuring the precise alignment of the surface to be processed with the filter joint. Next, the workpiece is radially tightened by the clamping ring and the positioning plate to prevent it from jumping or radially moving during the processing. In order to ensure the radial stability of the workpiece, the relative position between the clamping ring and the positioning plate is adjusted so that it fits the workpiece tightly and is fixed by a locking device. In addition, the axial jacking frame is firmly fitted to the end face of the workpiece using a tightening bolt, further ensuring the axial stability of the workpiece. The completion of this step lays the foundation for subsequent discharge machining.

[0017] Subsequently, the working fluid circulation system is started (S3). The start-up of the working fluid circulation system is an important preparatory step before EDM. First, ensure that the pressure of the high-pressure working fluid is 0.5 MPa. This pressure value can ensure the effective injection and cooling effect of the working fluid, and avoid damage to the workpiece and tool caused by excessive pressure. Then, the working fluid is injected from the working fluid injection ring and the filter joint, and flows evenly through the through hole of the drilling electrode tool. The uniform flow of the working fluid not only ensures the effective cooling of the machined surface, but also takes away the heat and debris generated during the machining process. These heat and debris are effectively discharged through the inner cavity of the drilling electrode tool and the gap between the core, and finally flow back into the working fluid recovery system. The effective operation of the working fluid circulation system ensures the stability and efficiency of the machining process.

[0018] Next, start the pulse power supply and adjust the parameters (S4). Starting the pulse power supply is one of the key steps in EDM. In this step, first start the pulse power supply, and then adjust the peak current, pulse width and pulse interval to the preset range. The peak current adjustment range is 1 to 20A, and this range is selected based on the processing requirements of different materials and experimental data. The peak current directly affects the efficiency and surface quality of EDM. The pulse width adjustment range is 100μs to 500μs, and the pulse interval adjustment range is 100μs to 500μs. The selection of pulse width and pulse interval is crucial to the stability and efficiency of EDM. Too wide pulse width and too short pulse interval may cause excessive discharge energy, causing damage to the workpiece and tool; while too narrow pulse width and too long pulse interval may cause insufficient discharge energy, affecting processing efficiency and surface quality. Therefore, in actual operation, it is necessary to reasonably adjust these parameters according to the processing materials and processing requirements. At the same time, set the axial feed speed, forward feed time and reverse feed time of the clamping concrete. The axial feed speed of the clamping body is set to 0.1-0.8mm / min. This speed range can ensure the stability of the processing process and avoid damage to the workpiece and tool caused by excessive feed speed. The forward feed time is set to 5-10min, and the reverse feed time is set to 1-3min. The combined use of forward feed and reverse feed not only improves the processing efficiency, but also helps to improve the quality and uniformity of the processed surface.

[0019] Before performing EDM in step S5, some necessary preparations are required. First, pre-inspect the tool connection sleeve, the drill electrode tool, the insulating connection pin and the clamp body to ensure that they are intact and fit tightly. The integrity and tight fit of these parts are the basis for ensuring the smooth progress of EDM. Secondly, pre-treat the workpiece to remove surface impurities and ensure the cleanliness of the machined surface. This step is crucial to improving machining quality and efficiency, because the presence of surface impurities may affect the stability and efficiency of EDM.

[0020] Enter step S5 and perform discharge machining. In the power-on state, start the axial feeding of the clamp body, first perform forward feeding processing, and then reverse feed for a period of time until the deep hole processing of the entire workpiece is completed. During the discharge machining process, the changes in the current and voltage waveforms during the machining process are monitored in real time. The current and voltage waveforms are important indicators reflecting the state of discharge machining. By real-time monitoring of these parameters, abnormal conditions during the machining process can be discovered and adjusted in time to ensure the stability of the discharge machining. At the same time, the feed speed of the clamp body is adjusted in real time according to the monitoring data. During the machining process, the machining state may change due to factors such as material removal and heat accumulation. Therefore, it is necessary to adjust the feed speed of the clamp body in real time according to the real-time monitoring data to adapt to the changes in the machining state and ensure the stability and efficiency of the machining process. In addition, the worn electrodes are regularly checked and replaced during the machining process. The electrode is a key component in discharge machining, and its degree of wear directly affects the machining quality and efficiency. Therefore, it is necessary to regularly check the wear of the electrode during the machining process, and replace the electrode with severe wear in time to ensure the machining quality and efficiency.

[0021] When implementing the deep hole discharge machining method of the present invention, the following points need to be noted: First, ensure the cleanliness and fit accuracy of all parts. The cleanliness and fit accuracy of tool connection sleeves, trepanning drill electrode tools, insulating connection pins, and clamps are crucial to the smooth progress of EDM. Therefore, these parts need to be carefully cleaned and inspected before processing to ensure that they meet the processing requirements.

[0022] Secondly, adjust the pressure and flow of the working fluid reasonably. The pressure and flow of the working fluid have an important impact on the stability and efficiency of EDM. Too high pressure may cause damage to the workpiece and tool, while too low pressure may affect the cooling and chip removal effect of the working fluid. Therefore, in actual operation, it is necessary to reasonably adjust the pressure and flow of the working fluid according to the processing requirements and experimental data.

[0023] In addition, pay attention to safety protection during the processing. Dangerous factors such as high temperature, sparks and harmful gases may be generated during the EDM process. Therefore, necessary safety protection measures need to be taken during the processing, such as wearing protective glasses, gloves and masks, to ensure the safety of operators.

[0024] Finally, handle abnormal situations in the machining process in a timely manner. During the EDM process, abnormal situations such as abnormal current and voltage waveforms, decreased machining efficiency, or poor workpiece surface quality may occur. These abnormal situations may be caused by factors such as material properties, machining parameters, or equipment status. Therefore, during the machining process, it is necessary to pay close attention to the changes in these indicators and take corresponding measures in a timely manner to ensure the smooth progress of the machining process and the stable improvement of machining quality.

[0025] In summary, the deep hole discharge machining method of the present invention realizes high-quality deep hole machining by combining precise positioning and clamping technology, efficient working fluid circulation system and precise pulse power supply control. In actual operation, it is necessary to pay attention to the cleanliness and matching accuracy of each component, reasonably adjust the pressure and flow of the working fluid, take necessary safety protection measures, and promptly handle abnormal situations during the machining process. The implementation of these measures will help improve machining efficiency and surface quality, reduce machining costs, and provide an efficient and precise machining method for the deep hole machining field.

[0026] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A deep hole electrical discharge machining method, characterized in that: The following steps are involved: S1. Positioning and clamping: Use the triangular chuck of the lathe spindle to clamp the tool connection sleeve, keep the lathe spindle still, and at the same time, tighten the drill electrode tool and the tool connection sleeve through the insulating connecting pin, adjust the slide box to position the specific axial position of the clamp, and ensure that the tool head of the drill electrode tool is located in the middle of the filter joint; S2. Workpiece installation and positioning: Place the workpiece in the through hole of the positioning plate, use the axial clamping frame to adjust the position of the clamp body, align the workpiece surface to be processed with the filter joint, and radially tighten the workpiece through the clamping ring and the positioning plate to prevent it from jumping; S3, start the working fluid circulation system: start the system, inject the high-pressure working fluid from the working fluid injection ring and the filter joint, flow into the processing surface through the through hole of the trepanning drill electrode tool, and flow back from the inner cavity of the tool and the gap between the core; S4, start pulse power supply and adjust parameters: start pulse power supply, adjust peak current, pulse width and pulse interval to preset range, and set axial feed speed, forward feed time and reverse feed time of the clamp; S5. Execute discharge machining: When the power is on, start the axial feed of the clamp body, first perform forward feed processing, and then reverse feed for a period of time until the deep hole processing of the entire workpiece is completed.

2. The deep hole electrical discharge machining method according to claim 1, characterized in that: In step S2, the workpiece installation and positioning further includes: accurately adjusting the position of the workpiece by an axial clamping frame; adjusting the relative position between the clamping ring and the positioning plate; and firmly fitting the axial clamping frame to the end face of the workpiece by using a clamping bolt.

3. The deep hole electrical discharge machining method according to claim 1, characterized in that: In step S3, the starting working fluid circulation system further includes: the pressure of the high-pressure working fluid is 0.5 MPa; after the working fluid is injected from the working fluid injection ring and the filter joint, it flows evenly through the through hole of the drilling electrode tool to effectively cool the processing surface; the heat and debris generated by the processing are discharged through the inner cavity of the drilling electrode tool and the gap between the core, and flow back into the working fluid recovery system.

4. The deep hole electrical discharge machining method according to claim 1, characterized in that: In step S4, the starting pulse power supply and adjustment parameters further include: the adjustment range of the peak current is 1-20A; the adjustment range of the pulse width is 100μs-500μs; the adjustment range of the pulse interval is 100μs-500μs; the axial feed speed of the clamp is set to 0.1-0.8mm / min, the forward feed time is set to 5-10min, and the reverse feed time is set to 1-3min.

5. The deep hole electrical discharge machining method according to claim 1, characterized in that: Before performing the electrical discharge machining in step S5, the method further includes: pre-inspecting the tool connecting sleeve, the drilling electrode tool, the insulating connecting pin and the clamping body; and pre-treating the workpiece to remove surface impurities.

6. The deep hole electrical discharge machining method according to claim 1, characterized in that: During the discharge machining process performed in step S5, the process also includes: real-time monitoring of current and voltage waveform changes during the machining process; real-time adjustment of the feed speed of the clamp according to the monitoring data; and regular inspection and replacement of worn electrodes during the machining process.