An electrical discharge machining method for a deep and narrow ventilation groove of a guide vane, and a guide vane

Abstract

The application provides an electric spark machining method for a deep and narrow ventilation groove of a guide vane and the guide vane, and the method comprises the following steps: first, electric spark high-speed small-hole machining is adopted, a plurality of bottom holes are machined on the guide vane to be machined by using a first electrode; then, a second electrode is made, the shaped electrode and corresponding clamping auxiliary components are installed to an electric spark forming machine; electric spark forming oil immersion machining is adopted, the lateral oil flushing of the guide vane to be machined is increased, the machining parameters of the electric spark forming machine are set, and the deep and narrow ventilation groove is machined. The application pre-machines part of the bottom holes in the position to be machined in the guide vane, and the method of electric spark forming machining of the shaped groove is adopted to machine the deep and narrow ventilation groove on the plurality of bottom holes, so that the oil flushing and chip removal conditions during the forming machining of the deep and narrow ventilation groove are improved, the electric spark forming machining efficiency and surface machining quality of the guide vane are improved. Moreover, the application can be applied to the machining of various deep holes, grooves and flow channels, and has good applicability.

Description

Technical Field

[0001] This invention belongs to the field of processing technology of air grooves for guide vanes, specifically relating to an electrical discharge machining method for deep and narrow air grooves of guide vanes and guide vanes. Background Technology

[0002] For aero-engine guide vanes made of LD2 aluminum alloy, to enhance cooling, the middle of the guide vane is machined with a deep and narrow ventilation groove, an inner cavity groove, and an exhaust port. A welded strip at the head position forms a cold air passage. The deep and narrow ventilation groove, located in the middle of the journal at the blade root, is inside the blade body and is relatively small, making it difficult to achieve using machining methods.

[0003] Currently, electrical discharge machining (EDM) is generally used for the guide vanes. However, due to the narrow width and deep depth of the grooves, and the fact that it involves blind cavity machining, the EDM process presents challenges in terms of scouring and chip removal. Poor removal of electrolytic corrosion products from the machined area can easily lead to carbon buildup and abnormal discharges, causing processing halts and extended processing times, thus affecting processing speed. Normally, machining this groove might take around 30 minutes, but if abnormal conditions such as carbon buildup and discharge occur, the machining time could exceed one hour. Furthermore, the blades are made of LD2 aluminum alloy, a material with high thermal conductivity and a low melting point, making it less machinable than EDM. Surface defects are prone to occur, including excessively thick remelted layers, cracks within the remelted layer, and arc burns. During installation and use, blade surface defects caused surface cracks. In summary, the current process for forming guide vane grooves may involve issues with oil flushing and chip removal, resulting in low processing efficiency, and the surface finish of the blades requires further optimization. Summary of the Invention

[0004] This invention provides an electrical discharge machining method for deep and narrow ventilation grooves of guide vanes and guide vanes, aiming to solve the problems of oil flushing and chip removal that may occur during the forming process of guide vane grooves, resulting in low processing efficiency and the need for further optimization of the processing quality of the blade surface.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] This invention provides an electrical discharge machining method for deep and narrow ventilation grooves of guide vanes, comprising the following steps:

[0007] S1. High-speed small hole machining using electrical discharge machining is employed. Machining parameters are set and the first electrode is selected. Several bottom holes are machined from the root side journal position of the guide vane to be machined inward.

[0008] Among them, the deep and narrow ventilation groove formed by the guide vane to be processed is a groove extending from the blade root side journal position to the inside of the guide vane to be processed.

[0009] S2. According to the groove shape parameters of the deep and narrow ventilation groove, fabricate the second electrode and install the second electrode and the corresponding auxiliary components into the EDM machine.

[0010] The cross-section of the second electrode is adapted to the cross-sectional shape of the deep and narrow ventilation groove;

[0011] S3. Install the second electrode onto the chuck and electrode clamp, and then install it onto the EDM machine; install the guide vane with several bottom holes onto the EDM machine using the vane clamp, and align the blade root side journal position of the guide vane with the second electrode; purge the guide vane laterally with liquid, add oil to the EDM machine, set the processing parameters of the EDM machine, and process the deep and narrow ventilation groove;

[0012] The guide vane to be processed has an inner cavity groove that opens along the head position, and at least a portion of the bottom hole is connected to the inner cavity groove.

[0013] In some embodiments, in S1, the high-speed electrical discharge machining of small holes specifically includes:

[0014] A fixture is fixedly installed on the high-speed EDM hole drilling machine, and the guide vane to be processed is clamped on the fixture; the first electrode with the required size parameters is installed on the high-speed EDM hole drilling machine, and the processing parameters of the high-speed EDM hole drilling machine are set.

[0015] When operation is required, turn on the EDM high-speed small hole machine and the high-pressure working fluid supply switch. The first electrode rotates while the high-pressure working fluid flushes. The EDM high-speed small hole machine discharges pulse sparks and drills holes in the guide vanes to be processed, forming several bottom holes in sequence.

[0016] Furthermore, in S1, during high-speed small hole machining via electrical discharge machining, the parameters for the bottom hole are set as follows: the depth of the bottom hole is 5-6 mm less than the depth of the deep and narrow venting groove.

[0017] In some embodiments, in S1, during machining, if the bottom hole is machined to communicate with the inner cavity groove, the high-speed EDM small hole machine is controlled to complete the machining of the bottom hole.

[0018] In some embodiments, in S1, the first electrode is a hollow copper tube electrode, and in the working state, high-pressure working fluid is introduced into the interior of the hollow copper tube electrode.

[0019] Furthermore, in S1, the radial dimension of the hollow copper tube electrode is controlled to be 1.93mm-1.95mm, and the flushing pressure inside the hollow tube is controlled to be 8MPa-10MPa.

[0020] In some embodiments, in S2, the second electrode is a hollow-formed electrode, formed by pressing a copper tube into shape based on the dimensional parameters of the deep and narrow ventilation groove.

[0021] Furthermore, in S3, during the installation process, the hollow forming electrode is installed onto the chuck and electrode clamp, and then the chuck and electrode clamp are connected to the EDM machine. The chuck and electrode clamp can be connected to an external dielectric flushing pipe so that EDM oil can be flushed onto the part of the machined deep and narrow ventilation groove during the machining process.

[0022] In some embodiments, S3 further includes adjusting the processing parameters of the electrical discharge machining machine to perform secondary finishing on the deep and narrow ventilation grooves processed in S3, thereby completing the electrical discharge machining of the deep and narrow ventilation grooves on the blade.

[0023] The present invention also provides a guide vane having a deep and narrow venting groove, which is manufactured by the above-mentioned electrical discharge machining method for deep and narrow venting grooves of guide vanes.

[0024] Compared with the prior art, the present invention provides an electrical discharge machining method for deep and narrow ventilation grooves in guide vanes and guide vanes, which has the following advantages:

[0025] This invention discloses an electrical discharge machining (EDM) method for creating deep and narrow ventilation grooves on a guide vane, comprising the following steps: S1. Using high-speed small-hole EDM, setting machining parameters and selecting a first electrode, machining a plurality of bottom holes along the root-side journal position of the guide vane to be machined, extending inward; wherein, the deep and narrow ventilation groove formed by machining the guide vane to be machined is a groove extending from the root-side journal position of the guide vane to its interior; S2. According to the groove shape parameters of the deep and narrow ventilation groove, fabricating a second electrode, and installing the second electrode and corresponding auxiliary components onto an EDM forming machine; wherein, the horizontal... The cross-section is adapted to the cross-sectional shape of the deep and narrow ventilation groove; S3, the second electrode is installed on the chuck and electrode clamp, and then installed on the EDM machine; the guide vane to be processed with several bottom holes is installed on the EDM machine through the blade fixture, and the position of the blade root side journal of the guide vane to be processed corresponds to the second electrode, the guide vane to be processed is flushed with liquid to the side, the EDM machine is filled with oil, the processing parameters of the EDM machine are set, and the deep and narrow ventilation groove is processed; wherein, the guide vane to be processed has an inner cavity groove that opens along the head position, and at least a portion of the bottom holes are connected to the inner cavity groove. Based on the above, this invention pre-machines some bottom holes at the locations to be machined in the guide vane forming groove, and then uses hollow copper electrode EDM to machine the forming groove. This method processes and forms deep and narrow ventilation grooves on several bottom holes. Furthermore, it combines full immersion-assisted hollow electrode oil flushing and lateral oil flushing for forming, improving the oil flushing and chip removal conditions during the forming of deep and narrow ventilation grooves, thus increasing the EDM forming efficiency and surface finish of the guide vane. This invention utilizes high-speed small-hole EDM and EDM forming technologies, by machining pre-made bottom holes and then machining them, and by designing a corresponding EDM forming electrode structure. This solves the problems of slow EDM speed, unstable machining, and defects in the remelted layer in guide vane EDM, effectively improving the machining quality and efficiency of deep and narrow ventilation grooves in aero-engine aluminum alloy guide vanes. Moreover, the machining method of this invention can be extended to the EDM machining of other parts with similar structural features, and can also be extended to the machining of deep holes, grooves, and flow channels with similar structural features, demonstrating excellent applicability. Attached Figure Description

[0026] The accompanying drawings are provided to further understand the invention and constitute a part of this invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an improper limitation of the invention.

[0027] Figure 1 This invention provides an electrical discharge machining method for deep and narrow ventilation grooves in a guide vane, and a schematic diagram of the structure of the guide vane.

[0028] Figure 2 This invention provides an electrical discharge machining method for deep and narrow venting grooves in a guide vane, and a schematic diagram of the location and structure of the deep and narrow venting grooves in the guide vane.

[0029] Figure 3 This invention provides an electrical discharge machining method for a deep and narrow ventilation groove in a guide vane, and a schematic diagram of the structure of the inner cavity groove in the guide vane.

[0030] Figure 4 This is a schematic diagram of the electrical discharge machining method for a deep and narrow ventilation groove in a guide vane, and the structure of the chuck and electrode clamping in the guide vane according to the present invention.

[0031] Figure 5 This is a schematic diagram of the electrical discharge machining method for deep and narrow ventilation grooves of guide vanes and the structure of the hollow forming electrode in the guide vanes according to the present invention.

[0032] Among them, 1. guide vane, 2. deep and narrow venting groove, 3. inner cavity groove, 4. exhaust hole, 5. sealing part, 6. hollow formed electrode, 7. tightening screw, 8. electrode clamp, 9. pull stud, 10. oil nozzle. Detailed Implementation

[0033] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0034] Therefore, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without inventive effort are within the scope of protection of the invention.

[0035] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0036] In the description of the embodiments of the present invention, it should be noted that if terms such as "upper," "lower," "horizontal," or "inner" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the product of the invention is in use, they are only for the convenience of describing the present invention 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 the present invention. Furthermore, terms such as "first" and "second" are only used to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0037] Furthermore, the use of the term "horizontal" does not imply that the component must be absolutely horizontal, but rather that it can be slightly tilted. For example, "horizontal" simply means that its direction is more horizontal than "vertical," and does not mean that the structure must be completely horizontal, but can be slightly tilted.

[0038] In the description of the embodiments of the present invention, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set," "install," "connect," and "link" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in the present invention according to the specific circumstances.

[0039] How to improve the oil flushing and chip removal conditions during the forming process of deep and narrow venting grooves, improve the efficiency and surface finish of electrical discharge machining when forming guide vanes for deep and narrow venting grooves, and thus improve the quality of guide vanes.

[0040] like Figures 1-3 As shown, the present invention provides an electrical discharge machining method for deep and narrow ventilation grooves of guide vanes, comprising the following steps:

[0041] S1. High-speed small hole machining using electrical discharge machining is employed. Machining parameters are set and the first electrode is selected. Several bottom holes are machined from the root side journal position of the guide vane to be machined inward.

[0042] Among them, the deep and narrow ventilation groove 2 formed by processing the guide vane to be processed is a groove extending from the blade root side journal position to the inside of the guide vane to be processed.

[0043] S2. Fabricate the second electrode according to the groove shape parameters of the deep and narrow ventilation groove 2, and install the second electrode and the corresponding auxiliary components into the EDM machine.

[0044] The cross-section of the second electrode is adapted to the cross-sectional shape of the deep and narrow ventilation groove 2;

[0045] S3. Install the second electrode onto the chuck and electrode clamp, and then install it onto the EDM machine; install the guide vane with several bottom holes onto the EDM machine using the blade fixture, and align the blade root side journal position of the guide vane with the second electrode. Use EDM oil immersion machining, and completely immerse the guide vane in the EDM oil. Pour liquid into the side of the guide vane, add oil to the EDM machine, set the machining parameters of the EDM machine, and perform machining of the deep and narrow ventilation groove 2.

[0046] The guide vane to be processed has an inner cavity groove 3 that opens along the head position, and at least a portion of the bottom hole is in communication with the inner cavity groove 3.

[0047] This invention employs high-speed small-hole EDM technology to machine several bottom holes inward from the journal position on the root side of the guide vane to be processed. These bottom holes form the basis for the subsequent formation of the deep and narrow ventilation groove 2. A second electrode is fabricated according to the groove shape parameters of the deep and narrow ventilation groove 2 and installed on the EDM machine along with auxiliary components. The cross-section of the second electrode matches the cross-sectional shape of the deep and narrow ventilation groove 2. The second electrode and the guide vane to be processed are installed on the EDM machine, and the deep and narrow ventilation groove 2 is processed by lateral flushing and setting processing parameters. The guide vane to be processed has an inner cavity groove 3, and some of the bottom holes are connected to the inner cavity groove 3. This method can accurately and efficiently process the deep and narrow ventilation groove 2, meeting the complex structural requirements of the guide vane. This invention is applicable to a wide range of processing materials, and there is no significant mechanical stress during processing, avoiding damage to the guide vane. This method reduces processing time, improves the flushing and chip removal during groove forming, and enhances the processing quality.

[0048] This invention employs high-speed EDM small-hole machining for the bottom holes, resulting in high efficiency and improved machining quality. High-speed EDM small-hole machining utilizes high-pressure water flushing, leading to fast processing speeds, a significant advantage in machining blind holes, and high machining accuracy. Machining four bottom holes takes only about 10 minutes. The depth of the deep-narrow venting groove 2 is typically 56mm, and the bottom hole machining depth of the hollow copper tube electrode is generally 5-6mm less than the depth of the deep-narrow venting groove 2. The radial dimension of the hollow copper tube electrode is controlled at 1.93mm-1.95mm, and the flushing fluid pressure inside the hollow tube is controlled at 8MPa-10MPa. This invention, by rationally setting the bottom hole depth, provides sufficient space for the subsequent machining of the deep-narrow venting groove 2, while avoiding over-machining that would result in the subsequent forming groove not completely covering the machined bottom hole. The hollow copper tube electrode provides better cooling and chip removal, contributing to improved machining efficiency and electrode lifespan. Precise control of electrode dimensions and flushing fluid pressure ensures the stability and accuracy of EDM.

[0049] The four pre-fabricated bottom holes are machined into a row of bottom holes with their edges close together but not connected. This can maintain high-pressure water pressure during the high-speed small hole machining process of EDM, and prevent pressure loss due to the small holes connecting together, thus giving full play to the high efficiency of high-speed small hole machining of EDM. At the same time, as much material can be removed as possible, which removes most of the machining allowance for forming the deep and narrow ventilation groove 2. In actual operation, the original forming time can be shortened from 30-40 minutes to 10 minutes.

[0050] The second electrode of this invention is a hollow-formed electrode 6 made by pressing a hollow copper tube. Copper electrodes have good discharge properties, good ductility, and are easy to form. The center of the hollow-formed electrode 6 is hollow, allowing the flow of a dielectric medium, increasing the discharge of electro-erosion products, improving the discharge condition, and enhancing the surface quality of the EDM (Electrical Discharge Machining) process. The hollow-formed electrode 6 is designed with a wall thickness of 1mm and a center gap of approximately 0.5mm. It can be pressed from a copper tube with an outer diameter of 10mm and a wall thickness of 1mm. The outer shape is ground to a 2.5mm × 14.5mm hollow-formed electrode 6, with a single-sided discharge gap of approximately 0.20mm, ensuring that the dimensions of the machined groove are within acceptable limits. This invention ensures the correct installation and stable processing of the hollow-formed electrode 6, while providing the necessary cooling and chip removal conditions.

[0051] By fully utilizing the milled inner cavity groove 3 from the previous process, and connecting it with the bottom hole of the high-speed small-hole machining to form a flushing channel, the flushing fluid inside the copper electrode core is increased, enhancing oil flushing and chip removal. This timely flushing removes electro-erosion products and carbon deposits generated during machining, ensuring sufficient cooling during the machining process. This improves the situation of carbon buildup and abnormal discharge during EDM, accelerates the discharge of discharge products, and improves the efficiency and surface quality of EDM. By adjusting the EDM process parameters, combining roughing and finishing, and increasing translational motion, the final EDM surface quality of the deep and narrow ventilation groove 2 is improved.

[0052] This invention also provides a guide vane having the aforementioned deep and narrow venting groove, which is formed by the electrical discharge machining (EDM) method of this invention. The final formed guide vane 1 has a deep and narrow venting groove 2, an inner cavity groove 3, and an exhaust port 4 machined in its middle, and a welded strip at the head position to form a cold air passage. The guide vane of this invention, with its precisely machined deep and narrow venting groove using EDM, can meet complex operational requirements and improve the performance and reliability of the guide vane.

[0053] The following detailed description of the present invention, including an electrical discharge machining method for a deep and narrow ventilation groove in a guide vane and the guide vane itself, is provided through specific embodiments.

[0054] Electrical discharge machining (EDM) methods for deep and narrow grooves in aluminum alloy guide vanes:

[0055] Pre-machine the pilot hole;

[0056] like Figure 1 As shown, during the EDM (Electrical Discharge Machining) process for the groove, the inner cavity groove on the side of the guide vane head, which is ultimately sealed by the welding strip, has been milled, forming a narrow slit 2mm wide. At this time, the strip has not yet been assembled and welded, creating an open space.

[0057] To address the issue of poor oil cooling in venting grooves during EDM machining, a pre-milled inner cavity groove 3 is utilized. A high-speed EDM small hole machine is used to pre-machine a bottom hole from the journal side. Within a 3mm × 15mm area at the groove location, the bottom hole is machined, connecting with the milled inner cavity groove. Oil is then laterally flushed through the milling cutter groove gap, creating an open channel that improves chip removal and cooling. To facilitate small hole machining, four adjacent 2mm diameter holes are machined side-by-side, with no connection between them. This facilitates high-speed EDM discharge and allows for the removal of more machining material in subsequent processes.

[0058] like Figure 4 and Figure 5 As shown, in actual operation, the present invention can use a copper electrode to process the hollow electrode 6, making the center a hollow electrode, and adding an oil flushing channel on the electrode chuck 8. The hollow electrode flushes and cools the EDM part, promptly flushing away the discharge products and forming a good discharge environment.

[0059] Specifically: Fixtures and blades are fixedly installed on the high-speed EDM small hole machine, aligned and tightened.

[0060] The high-speed EDM small hole machine is equipped with a copper tube electrode with a diameter of 1.95mm. High-pressure water is turned on to flush the fluid. Four bottom holes with a diameter of 2mm are machined in the journal hole of the guide vane 1 to find the position of the aligning groove. The machining depth is set to 50mm. The machining process is adjusted based on visually observing the water flow to ensure that the hole is connected to the inner cavity groove.

[0061] like Figure 4 As shown, the electrode shaft of the EDM machine is connected by the rivet 9. The electrode chuck 8 and the hollow forming electrode 6 are installed on the EDM machine. The tightening screw 7 tightens the hollow forming electrode 6. An oil flushing channel is added to the electrode chuck 8. An oil nozzle 10 is installed on the electrode chuck and connected to the dielectric oil flushing pipe (not shown in the figure). EDM oil is flushed to the part of the deep and narrow ventilation groove 2 through the channel of the oil nozzle 10 and the hollow forming electrode 6.

[0062] The blade fixture is installed on the EDM machine, and the guide vane 1 is installed. The side flushing oil pipe is aligned with the milling cutter edge of the cavity groove 3 and flushes oil from the side. The EDM machine is filled with oil until the liquid level submerges the guide vane 1. The forming process is carried out by using full immersion assisted hollow electrode flushing and side flushing.

[0063] The present invention first selects electrical discharge machining parameters to rough machine the deep and narrow ventilation groove 2 by electrical discharge forming. After the rough machining of the deep and narrow ventilation groove 2 is completed, the parameters are adjusted to finish the deep and narrow ventilation groove 2. At the same time, translation is increased to improve the accuracy of the inner surface of the groove, and finally the finely machined guide vane is formed.

[0064] This invention discloses an electrical discharge machining (EDM) method for deep and narrow ventilation grooves on guide vanes, and the guide vanes themselves. This method solves the problems of long machining time, thick remelted layer, arc burns, and rough surface of ventilation grooves on guide vanes of a certain type of aero-engine. By optimizing the EDM parameters, the problems of slow EDM speed, unstable machining, and defects in the remelted layer of the guide vane 1 are improved. In practical applications, the machining time of the deep and narrow ventilation groove 2 is reduced from 40 minutes to less than 20 minutes, and the production efficiency is more than doubled. This machining method can be applied to the EDM machining of other parts with similar structural features, as well as the machining of deep holes, grooves, and flow channels with similar structural features. By pre-fabricating a flushing channel in the EDM forming area of ​​the part, the high efficiency of the high-speed small-hole EDM machining method can be utilized to remove some material, and the problems of poor flushing and abnormal discharge during the EDM forming process can be improved, which can significantly improve the production efficiency and has good applicability.

[0065] Finally, it should be noted that the above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Those skilled in the art can readily implement the present invention according to the description and above. However, any modifications, alterations, or variations made by those skilled in the art without departing from the scope of the present invention, based on the disclosed technical content, are equivalent embodiments of the present invention. Furthermore, any equivalent changes, alterations, or variations made to the above embodiments based on the essential technology of the present invention are still within the protection scope of the present invention.

Claims

1. An electrical discharge machining method for deep and narrow ventilation grooves on guide vanes, characterized in that, Includes the following steps: S1. High-speed small hole machining using electrical discharge machining is employed. Machining parameters are set and the first electrode is selected. Several bottom holes are machined from the root side journal position of the guide vane to be machined inward. Among them, the deep and narrow ventilation groove (2) formed by processing the guide vane to be processed is a groove from the blade root side journal position to the inside of the guide vane to be processed. Several bottom holes are machined in a row, with their edges close together but not connected; High-speed electrical discharge machining for small holes specifically includes: A fixture is fixedly installed on the high-speed EDM hole drilling machine, and the guide vane to be processed is clamped on the fixture; the first electrode with the required size parameters is installed on the high-speed EDM hole drilling machine, and the processing parameters of the high-speed EDM hole drilling machine are set. When operation is required, turn on the EDM high-speed small hole machine and the high-pressure working fluid supply switch. The first electrode rotates while the high-pressure working fluid flushes. The EDM high-speed small hole machine discharges pulse sparks and drills holes in the guide vanes to be processed, forming several bottom holes in sequence. In high-speed small hole machining via electrical discharge machining, the parameters of the bottom hole are set as follows: the depth of the bottom hole is 5-6 mm smaller than the depth of the deep and narrow venting groove (2); S2. Fabricate the second electrode according to the groove parameters of the deep and narrow ventilation groove (2), and install the second electrode and the corresponding auxiliary components into the electrical discharge forming machine. Among them, the cross-section of the second electrode is adapted to the cross-sectional shape of the deep and narrow ventilation groove (2); The second electrode is a hollow-formed electrode (6). Based on the size parameters of the deep and narrow ventilation groove (2), it is formed by pressing copper tubes to form a hollow-formed electrode (6). The hollow forming electrode (6) is designed with a wall thickness of 1 mm and a center gap of 0.5 mm. It is made by pressing a copper tube with an outer diameter of 10 mm and a wall thickness of 1 mm. S3. The second electrode is installed on the electrode chuck and electrode clamp designed with an oil flushing channel, and then installed on the EDM machine. The guide blade with several bottom holes is installed on the EDM machine through the blade clamp, and the blade root side journal position of the guide blade corresponds to the second electrode. The guide blade is flushed with liquid to the side, the EDM machine is filled with oil, the processing parameters of the EDM machine are set, and the deep and narrow ventilation groove (2) is processed. During the installation process, the hollow forming electrode (6) is installed into the chuck and electrode clamp, and then the chuck and electrode clamp is connected to the EDM machine. The chuck and electrode clamp can be connected to an external dielectric flushing pipe so that EDM oil can be flushed onto the part of the deep and narrow ventilation groove (2) during the processing state. The guide vane to be processed has an inner cavity groove (3) with an opening at the head position, and at least a portion of the bottom hole is connected to the inner cavity groove (3).

2. The electrical discharge machining method for the deep and narrow ventilation grooves of the guide vanes according to claim 1, characterized in that, In S1, during the machining process, if the bottom hole is machined to be connected to the inner cavity groove (3), the high-speed small hole machine is controlled to complete the machining of the bottom hole.

3. The electrical discharge machining method for the deep and narrow ventilation grooves of the guide vanes according to claim 1, characterized in that, In S1, the first electrode is a hollow copper tube electrode, and in the working state, high-pressure working fluid is introduced into the interior of the hollow copper tube electrode.

4. The electrical discharge machining method for the deep and narrow ventilation grooves of the guide vanes according to claim 3, characterized in that, In S1, the radial dimension of the hollow copper tube electrode is controlled to be 1.93mm-1.95mm, and the flushing pressure inside the hollow tube is controlled to be 8MPa-10MPa.

5. The electrical discharge machining method for the deep and narrow ventilation grooves of the guide vanes according to claim 1, characterized in that, S3 also includes adjusting the processing parameters of the EDM forming machine to perform secondary finishing on the deep and narrow ventilation groove (2) processed by S3, thereby completing the EDM processing of the deep and narrow ventilation groove (2) of the blade.

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