An electric spark tool for batch clamping turbine blades and a method of using the same

Abstract

The invention discloses an electric spark tool for batch clamping turbine blades, comprising a base, a positioning tooth block, a bracket, a pressure plate, a clamping screw and a positioning pin. The base is connected to a forming machine workbench and is provided with a plurality of inclined grooves and inclined surfaces, and the inclination angle α of each inclined groove and inclined surface is consistent with the inclination angle of the blade tenon; the positioning tooth block is arranged at the front end of the inclined groove of the base and is fixedly connected to the base, and a first positioning tooth is arranged at the front end to cooperate with the tenon at the back arc end of the blade; the bracket is arranged at the rear end of the inclined groove of the base and is fixedly connected to the base, and a notch is opened at the front end; the pressure plate is arranged above the positioning tooth block and the bracket, penetrates into the notch of the bracket and is connected to the bracket through a pin shaft, and a second positioning tooth is arranged at the front end to cooperate with the tenon at the inner arc end of the blade; the clamping screw is arranged at the rear end of the pressure plate and is screwed with the pressure plate to drive the pressure plate to move up and down to clamp or loosen the blade; the positioning pin is arranged on the inclined surface of the base and contacts with the tenon at the blade to limit the left and right movement of the blade; the invention also discloses a method for using the electric spark tool.

Description

Technical Field

[0001] The invention belongs to the technical field of electric spark machining of turbine blades, and relates to an electric spark tool for batch clamping turbine blades and a use method thereof. Background Art

[0002] The turbine rotor is the main rotating part of machines such as steam compressors, aeration blowers, and superchargers. It uses the steam generated by the heat recovery system to drive its operation through compression to do work. The turbine blades are important parts on the turbine rotor that convert the energy of high-temperature combustion gas into mechanical work of the rotor. The specific method is: the high-temperature combustion gas impacts the turbine blades, driving the turbine rotor to rotate at high speed. The higher the combustion gas temperature, the more work is done. However, when working, the turbine blades must not only withstand the corrosion and erosion caused by high-temperature combustion gas, but also the huge centrifugal force, gas force and vibration load generated by high-speed rotation. In order to ensure the working stability of the turbine rotor, it is necessary to process a tie rod hole at the front end of the turbine blade, and connect the blades into groups through tie rod wires to enhance the strength of the blades while adjusting the self-vibration frequency of the blades to improve the resonance.

[0003] Therefore, it is particularly important to ensure the quality of the processing and manufacturing of the tie rod holes of turbine blades. However, due to the extremely harsh working environment of turbine blades, it is necessary to use special alloy materials with high lasting strength and sufficient toughness in high temperature environments, good resistance to thermal fatigue and mechanical fatigue, and high resistance to high temperature oxidation and thermal corrosion. The material processing is difficult. Through on-site investigation, we learned in detail about the processing flow of the VTR304 turbine blades and learned that in the existing processing technology of the tie rod holes of turbine blades, the existing EDM tools have the following problems:

[0004] 1. When using this tool to process the reinforcement holes of turbine blades, only one blade can be clamped for processing at a time, and two processes are required: pre-drilling with an EDM machine and cutting into holes with a wire cutter. The processing efficiency is low and cannot meet the actual development needs of the enterprise;

[0005] 2. The reinforcement holes are prone to tapered holes during processing, which may cause the reinforcement wires to be blocked or even unable to pass through;

[0006] 3. Existing electric spark tools do not have locking devices. After the tools have been used for a period of time, the parts will wear out, which will cause the turbine blades to be unstable. Summary of the invention

[0007] The purpose of the present invention is to overcome the shortcomings of the prior art and to provide an EDM tool for batch clamping turbine blades and a method of using the tool for processing turbine blade tie rod holes. The tool can clamp 5 blades at the same time for processing and can be used in conjunction with an EDM forming machine tool to shorten the two-step process (EDM pre-hole drilling + wire cutting to cut holes) in the original tie rod hole processing process to a one-step process (EDM one-time forming of tie rod holes). While improving the processing efficiency, it also solves the problem of tapered holes generated during the processing of the original tie rod holes.

[0008] The object of the present invention is achieved in that:

[0009] An electric spark tool for batch clamping turbine blades is placed on a workbench of an electric spark forming machine and is used for batch processing of tie rod holes of turbine blades. It includes a base connected to the workbench, a top of the base is provided with a plurality of inclined grooves and a plurality of inclined surfaces along the front-to-back direction, and an inclination angle α of each inclined groove and inclined surface to the horizontal plane is consistent with the inclination angle of the tenon of the turbine blade, so that the turbine blade is clamped to the electric spark tool at an angle of α; a positioning tooth block is arranged at the front end of the inclined groove of the base and is fastened with a screw of the base, a first positioning tooth is arranged at the front end of the positioning tooth block, and cooperates with the tenon at the back arc end of the turbine blade to locate the clamping position of the turbine blade; a bracket is arranged at the rear end of the inclined groove of the base and is fastened with the base by screws, a notch is opened at the front end of the bracket; a pressing plate is arranged above the positioning tooth block and the bracket, penetrates into the notch of the bracket and is connected to the bracket through a pin shaft, and the pressing plate A second positioning tooth is provided at the front end, which cooperates with the tenon tooth at the inner arc end of the turbine blade. The pressure plate is used in conjunction with the positioning tooth block. After the positioning tooth block clamps and positions the turbine blade, the second positioning tooth of the pressure plate presses the tenon tooth of the turbine blade downward to fix the turbine blade in place and limit the up and down movement of the turbine blade; a clamping screw is arranged at the rear end of the pressure plate and is threadedly connected to the pressure plate. The pressure plate is driven to move up and down by rotating the clamping screw, and the second positioning tooth of the pressure plate then clamps or loosens the turbine blade; a positioning pin is arranged on each inclined surface of the base and is tightly connected to the base. The positioning pin is provided with a spherical head, which contacts with a side surface of the tenon tooth of the turbine blade to limit the movement of the turbine blade in the left and right directions and improve the clamping position accuracy of the turbine blade; after the electric spark tool clamps and positions the turbine blade, the electrode rod installed in the vertical direction of the electric spark forming machine is directly opposite to the processing position of the reinforcing bar hole of the turbine blade.

[0010] Furthermore, the base is provided with five inclined grooves and five inclined surfaces, and each inclined groove is installed with a positioning tooth block, a bracket, a pressure plate and a tightening screw.

[0011] Furthermore, the positioning tooth block is provided with two first positioning teeth. When the positioning tooth block is clamped on the turbine blade, the first positioning tooth located at the front end cooperates with the fourth tenon tooth at the back arc end of the turbine blade for positioning, and the first positioning tooth located at the rear end cooperates with the second tenon tooth at the back arc end of the turbine blade for positioning.

[0012] Furthermore, when the pressure plate presses the turbine blade, the second positioning tooth of the pressure plate cooperates with the third tenon tooth at the inner arc end of the turbine blade for positioning. A pin hole and a clearance groove are provided in the middle of the pressure plate. The pin hole is used to pass the pin shaft, and the clearance groove cooperates with the support ear at the front end of the bracket to be installed so that the middle part of the pressure plate is clamped in the groove of the bracket.

[0013] Furthermore, the clamping screw can increase or decrease the number of rotations according to the wear of the parts in the electric spark tool, and freely adjust the clamping force of the pressure plate to achieve locking of the pressure plate on the turbine blades.

[0014] Furthermore, cylindrical pins are provided between the positioning tooth block and the inclined groove of the base, and between the bracket and the inclined groove of the base. The positioning tooth block is reliably positioned by the cylindrical pins, screws and the inclined groove of the base, and the bracket is reliably positioned and installed with the base by the screws and cylindrical pins.

[0015] A method for using an electric spark tool for batch clamping turbine blades comprises the following steps:

[0016] Step 1: Assemble the aforementioned EDM tool for batch clamping turbine blades. First, place the positioning tooth block and the bracket in each inclined groove of the base and fix them with screws and cylindrical pins. Ensure that the positioning tooth block and the bracket are installed in place on the base by inserting the cylindrical pins, screws and the inclined grooves of the base. Then connect the pressure plate and the bracket through the pin shaft, screw the clamping screw into the threaded hole at the rear end of the pressure plate, and finally install the positioning pin on each inclined surface of the base.

[0017] Step 2: Clean the work surface of the EDM forming machine, and then place the EDM tool. After placement, make sure that the parallelism between the upper plane of the EDM tool and the plane of the work surface and the verticality between the side of the EDM tool and the plane of the work surface are within the design range, and then use the electromagnet on the work surface to suck the base and securely fix the EDM tool;

[0018] Step 3: Clamp the positioning rod on the EDM tool, determine the position of the reinforcement hole to be processed on each turbine blade by aligning the positioning rod, and input the coordinate values ​​corresponding to each hole in the CNC program;

[0019] Step 4: Remove the positioning measuring rod, clamp the turbine blade on the electric spark tool, and face the inner arc end of the turbine blade upward. The fourth tenon and the second tenon on the back arc end of the turbine blade are respectively positioned with the first positioning teeth at the front and rear ends of the positioning tooth block to determine the clamping position of the turbine blade. After the positioning tooth block positions the turbine blade, rotate the clamping screw to drive the pressure plate to move downward. The second positioning tooth at the front end of the pressure plate presses the third tenon at the inner arc end of the turbine blade downward to position and clamp the turbine blade. The profile on one side of the tenon of the turbine blade contacts the head of the positioning pin to limit the left and right directions of the turbine blade.

[0020] Step 5: Process the reinforcement holes one by one. Before processing the reinforcement holes, the verticality of the electrode rod needs to be calibrated to ≤0.01mm.

[0021] Due to the adoption of the above technical solution, the present invention has the following beneficial effects:

[0022] 1. The electric spark tool of the present invention can clamp a plurality of turbine blades in batches at one time.

[0023] 2. The application of the electric spark tool of the present invention simplifies the processing technology, shortening the original electric spark pre-hole drilling + wire cutting to hole cutting to electric spark one-time hole cutting.

[0024] 3. Shortened processing time and improved processing efficiency. According to experimental verification, it took 2189 minutes to process 200 blades using the original processing method. After adopting the new EDM tool, the processing technology was streamlined and the processing time was shortened to 1513 minutes. The processing efficiency was improved by about 30%.

[0025] 4. The electric spark tool of the present invention is used to perform one-time electric spark machining of the rod drawing hole to a finished hole, thereby solving the problem of the original machining method leading to the formation of a tapered hole and improving the machining quality.

[0026] 5. Five turbine blades are clamped on the EDM tool at one time for processing. The processing time for one blade is about 7 minutes, and the total processing time is about 35 minutes. This reduces the frequency of workers changing blades for clamping and reduces the labor intensity of workers. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a front view of the present invention;

[0028] Figure 2 is a top view of the present invention;

[0029] Figure 3 yes Figure 1 Middle AA section view;

[0030] Figure 4 It is the front view of the base;

[0031] Figure 5It is a top view of the base;

[0032] Figure 6 It is the front view of the positioning gear block;

[0033] Figure 7 It is a top view of the positioning gear block;

[0034] Figure 8 It is the front view of the pressure plate;

[0035] Fig. 9 is a top view of the pressure plate;

[0036] Fig.10 is a schematic diagram of the structure of the compression screw;

[0037] Fig.11 is the main view of the bracket;

[0038] Fig.12 is a top view of the bracket;

[0039] Fig.13 It is the left side view of the bracket;

[0040] Fig.14 It is a schematic diagram of the structure of the positioning pin;

[0041] Fig.15a It is the main view of the positioning measuring rod;

[0042] Fig.15b yes Fig.15a BB cross-sectional view;

[0043] Fig.15c yes Fig.15b Rotate the view in the A direction;

[0044] Fig.16a It is a schematic diagram of the structure of the tenon tooth part of the turbine blade;

[0045] Fig.16b It is a schematic diagram of the structure of the back arc end and inner arc end of the turbine blade.

[0046] Reference numerals

[0047] In the attached drawings, 1 is a base, 2 is a screw, 3 is a positioning tooth block, 4 is a pressure plate, 5 is a pin shaft, 6 is a retaining ring, 7 is a clamping screw, 8 is a bracket, 9 is a cylindrical pin, 10 is a positioning pin, 11 is a turbine blade, 12 is a positioning measuring rod,

[0048] 101 is an inclined groove, 102 is an inclined slope, 301 is a first positioning tooth, 401 is a second positioning tooth, 402 is a pin hole, 403 is a clearance groove, 801 is a notch, 802 is a support ear, 1001 is a spherical head, 1101 is the back arc end of the turbine blade, 1102 is the inner arc end of the turbine blade, 1103 is the fourth tenon tooth, 1104 is the second tenon tooth, 1105 is the third tenon tooth, 1106 is a profile on one side of the tenon tooth, and 1107 is a tie rod hole. DETAILED DESCRIPTION

[0049] The embodiments of the present invention are further described in detail below with reference to the accompanying drawings.

[0050] See also Figure 1-16b As shown, an EDM tool for batch clamping turbine blades is placed on a workbench of an EDM forming machine and is used for batch processing of the reinforcing holes 1107 of turbine blades 11. The tool comprises a base 1, a positioning tooth block 3, a bracket 8, a pressure plate 4, a clamping screw 7 and a positioning pin 10. The base 1 is connected to the workbench. A plurality of inclined grooves 101 and a plurality of inclined slopes 102 are provided on the top of the base 1 along the front-to-back direction. Since the turbine blade 11 in the present invention is in the shape of a helical tenon, the inclination angle α of each inclined groove 101 and inclined slope 102 with the horizontal plane is consistent with the inclination angle of the tenon of the turbine blade 11. The inclination angle of the tenon of the turbine blade 11 in the present invention is 17°. Therefore, the top of the base 1 is designed to be inclined so that the turbine blade 11 is clamped on the EDM tool at a certain angle (17°), so that the electrode rod installed in the vertical direction of the EDM forming machine can face the processing position of the reinforcing hole 1107 of the turbine blade.

[0051] like Figure 4 , Figure 5 As shown, in this embodiment, the base is provided with five inclined grooves 101 and five inclined surfaces 102, each inclined groove 101 is installed with a positioning tooth block 3, a bracket 8, a pressure plate 4 and a clamping screw 7, and a safety distance is set between two adjacent inclined grooves 101 to ensure that the turbine blades 11 are installed smoothly without interfering with each other.

[0052] like Figure 1 , Figure 6 , Figure 7As shown, the positioning tooth block 3 is arranged at the front end of the inclined groove 101 of the base, and is fastened to the base 1 by a screw 2. A first positioning tooth 301 is provided at the front end of the positioning tooth block 3, which cooperates with the tenon tooth of the back arc end 1101 of the turbine blade to position the clamping position of the turbine blade 11; there are two first positioning teeth 301 of the positioning tooth block. When the positioning tooth block 3 clamps the turbine blade, the inner arc end 1102 of the turbine blade faces upward, the first positioning tooth 301 at the front end cooperates with the fourth tenon tooth 1103 at the back arc end of the turbine blade for positioning, and the first positioning tooth 301 at the rear end cooperates with the second tenon tooth 1104 at the back arc end of the turbine blade for positioning, and a cylindrical pin 9 is further provided between the positioning tooth block 3 and the inclined groove 101 of the base. Each positioning tooth block 3 is connected to the base 1 by an M6 screw 2. The positioning tooth block 3 is ensured to be installed in place on the base by means of the cylindrical pin 9 and the inclined groove 101 of the base that is snapped into place.

[0053] like Figure 1 , Figure 11-13 As shown, the bracket 8 is arranged at the rear end of the inclined groove 101 of the base and is fastened to the base 1 by means of screws 2. A slot 801 is provided at the front end of the bracket 8. A cylindrical pin 9 is also provided between the bracket 8 and the inclined groove 101 of the base. The bracket 8 is reliably positioned and installed with the base by means of the M8 screws 2 and the cylindrical pin 9.

[0054] like Figure 1 , Figure 8 , Fig. 9 As shown, the pressing plate 4 is arranged above the positioning tooth block 3 and the bracket 8, penetrates into the bracket notch 801 and is connected to the bracket 8 through the pin shaft 5 and the retaining ring 6. The pin shaft 5 limits the movement of the pressing plate 4 in the axial and radial directions, so that it can only rotate around the center of the pin shaft 5. The pressing plate 4 and the base 1 are connected through the bracket 8 to form a whole. The front end of the pressing plate 4 is provided with a second positioning tooth 401, which cooperates with the tenon tooth of the inner arc end 1102 of the turbine blade. The pressing plate 4 is used in conjunction with the positioning tooth block 3. When the positioning tooth block 3 is aligned with the turbine blade 11 After clamping and positioning, the second positioning tooth 401 of the pressure plate presses the tenon of the turbine blade downward to fix the turbine blade in place and restrict the up and down movement of the turbine blade 11; when the pressure plate 4 presses the turbine blade 11, the second positioning tooth 401 of the pressure plate cooperates with the third tenon 1105 at the inner arc end of the turbine blade for positioning, and a pin hole 402 and a clearance groove 403 are provided in the middle of the pressure plate 4. The pin hole 402 is used to pass the pin shaft 5, and the clearance groove 403 cooperates with the support ear 802 at the front end of the bracket to make the middle part of the pressure plate 4 clamped in the slot 801 of the bracket.

[0055] like Figure 1 , Fig.10As shown, the clamping screw 7 is arranged at the rear end of the pressure plate 4, and the clamping screw 7 is provided with a threaded section, which is threadedly connected with the pressure plate 4. After the clamping screw 7 is screwed into the threaded hole at the rear end of the pressure plate 4, the position of the pressure plate 4 is fixed by the bracket 8 and the pin 5. At this time, the pressure plate 4 is driven to move up and down by rotating the clamping screw 7, and the second positioning teeth 401 of the pressure plate further clamp or loosen the turbine blade 11; when the clamping screw 7 rotates clockwise, the pressure plate 4 moves down, and the second positioning teeth 401 of the pressure plate clamp the turbine blade 11, and when the clamping screw 7 rotates counterclockwise, the pressure plate 4 moves up, and the second positioning teeth 401 of the pressure plate loosen the turbine blade 11;

[0056] The clamping screw 7 can increase or decrease the number of rotations according to the wear of the parts in the EDM tool, and freely adjust the clamping force of the pressure plate 4 to achieve locking of the pressure plate 4 on the turbine blades 11, solving the problem of unstable clamping of the turbine blades due to wear of parts in the original EDM tool after use.

[0057] like Figure 1 , Fig.14 As shown, the positioning pin 10 is arranged on each inclined surface 102 of the base and is tightly connected with the base 1. The positioning pin 10 is provided with a spherical head 1001, which contacts with a side surface 1106 of the turbine blade tenon. Since the positioning tooth block 3 and the pressure plate 4 limit the movement of the turbine blade 11 in the up and down directions, the positioning pin 10 is designed to limit the movement of the turbine blade 11 in the left and right directions, thereby improving the clamping position accuracy of the turbine blade 11.

[0058] A method for using an electric spark tool for batch clamping turbine blades of the present invention comprises the following steps:

[0059] Step 1: Assemble the aforementioned EDM tool for batch clamping turbine blades. First, place the positioning tooth block and the bracket in each inclined groove of the base and fix them with screws and cylindrical pins. Ensure that the positioning tooth block and the bracket are installed in place on the base by inserting the cylindrical pins, screws and the inclined grooves of the base. Then connect the pressure plate and the bracket through the pin shaft, screw the clamping screw into the threaded hole at the rear end of the pressure plate, and finally install the positioning pin on each inclined surface of the base.

[0060] Step 2: Clean the work surface of the EDM forming machine, and then place the EDM tool. After placement, make sure that the parallelism between the horizontal surface of the EDM tool and the plane of the work surface and the verticality between the vertical surface of the EDM tool and the plane of the work surface are within the design range, and then use the electromagnet on the work surface to suck the base and securely fix the EDM tool;

[0061] Step 3: Clamp the positioning rod 12 on the EDM tool, determine the position to be processed of the tie rod hole 1107 on each turbine blade by aligning the positioning rod 12, and input the coordinate values ​​corresponding to each hole in the CNC program;

[0062] like Figures 15a to 15c As shown, the positioning rod is equivalent to a standard block. One end of the positioning rod has the same tooth shape as the tenon shape of the turbine blade. Before processing the turbine blade, the positioning rod is first installed on the EDM tool. The position of the hole on the positioning rod is the position of the tie rod hole to be processed on the turbine blade. Before the tie rod hole is processed, the position of the hole on the positioning rod is corrected to confirm the position of the tie rod hole to be processed on the turbine blade. After the turbine blade is processed, the actual processed tie rod hole and the hole position on the positioning rod are detected and compared with the instrument to determine whether the processing of the turbine blade tie rod hole is qualified.

[0063] Step 4: Remove the positioning measuring rod, clamp the turbine blade on the electric spark tool, and face the inner arc end of the turbine blade upward. The fourth tenon and the second tenon on the back arc end of the turbine blade are respectively positioned with the first positioning teeth at the front and rear ends of the positioning tooth block to determine the clamping position of the turbine blade. After the positioning tooth block positions the turbine blade, rotate the clamping screw to drive the pressure plate to move downward. The second positioning tooth at the front end of the pressure plate presses the third tenon at the inner arc end of the turbine blade downward to position and clamp the turbine blade. The profile on one side of the tenon of the turbine blade contacts the head of the positioning pin to limit the left and right directions of the turbine blade.

[0064] Step 5: Process the reinforcement holes one by one. Before processing the reinforcement holes, the verticality of the electrode rod needs to be corrected ≤

[0065] 0.01mm.

[0066] To ensure the position of the tie rod holes and the roughness of the inner holes, before placing the EDM tool on the forming machine workbench, step 2 is required to clean the EDM forming machine workbench and align the tool end face to ensure that after the blade is installed on the EDM tool, the tie rod holes on the blade are at the same height and in the same straight line.

[0067] Since the EDM tool in this embodiment is to process five turbine blades continuously after one clamping, in order to ensure that the position of each tie rod hole meets the design requirements, step 3 needs to be performed to clamp the positioning rod after the new EDM tool is aligned and fixed. By aligning the positioning rod, the position of each turbine blade tie rod hole is determined.

[0068] To ensure the processing quality of the tie rod holes, step 5 needs to be performed to calibrate the verticality of the electrode rod to ≤0.01mm. The verticality needs to be recalibrated each time the electrode rod is replaced.

[0069] The novel EDM tool of the present invention is used in conjunction with the company's existing AF50 EDM forming machine. Before processing, the processing position of the tie rod hole of the first blade on the far left is first determined, and then the tie rod holes of each blade are processed to the right in turn. The present invention can integrate the original two-step process of pre-control hole drilling and hole cutting into a one-step EDM process, and five turbine blades can be processed continuously after one clamping, which improves the processing efficiency and can also solve the problem of tapered holes in the process of tie rod hole processing.

[0070] Finally, it should be noted that the above preferred embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail through the above preferred embodiments, those skilled in the art should understand that various changes can be made in form and details without departing from the scope defined by the claims of the present invention.

Claims

1. An EDM tool for batch clamping turbine blades, placed on the workbench of an EDM forming machine, used for batch processing of tie rod holes of turbine blades, characterized in that: include A base is connected to the workbench, and a plurality of inclined grooves and a plurality of inclined surfaces are provided on the top of the base along the front-back direction, and an inclination angle α of each inclined groove and inclined surface to the horizontal plane is consistent with an inclination angle of the tenon of the turbine blade, so that the turbine blade is clamped on the electric spark tool at an angle of α; The positioning tooth block is arranged at the front end of the inclined groove of the base and is fastened with the base screw. The front end of the positioning tooth block is provided with a first positioning tooth, which cooperates with the tenon tooth at the back arc end of the turbine blade to locate the clamping position of the turbine blade; The bracket is arranged at the rear end of the inclined groove of the base and is fastened to the base by screws, and a notch is provided at the front end of the bracket; A pressure plate is arranged above the positioning tooth block and the bracket, penetrates into the bracket notch and is connected to the bracket through a pin shaft. A second positioning tooth is arranged at the front end of the pressure plate, which cooperates with the tenon tooth at the inner arc end of the turbine blade. The pressure plate is used in conjunction with the positioning tooth block. After the positioning tooth block clamps and positions the turbine blade, the second positioning tooth of the pressure plate presses the tenon tooth of the turbine blade downward to tightly position the turbine blade and restrict the turbine blade from moving up and down. The clamping screw is arranged at the rear end of the pressure plate and is threadedly connected to the pressure plate. The pressure plate is driven to move up and down by rotating the clamping screw, and the second positioning teeth of the pressure plate clamp or loosen the turbine blades. A positioning pin is arranged on each inclined surface of the base and is tightly connected with the base. The positioning pin is provided with a spherical head and contacts with a side profile of the tenon of the turbine blade to limit the movement of the turbine blade in the left and right directions and improve the clamping position accuracy of the turbine blade; After the electric spark tool is clamped and positioned on the turbine blade, the electrode rod installed in the vertical direction of the electric spark forming machine is directly opposite to the processing position of the reinforcing bar hole of the turbine blade.

2. The electric spark tool for batch clamping turbine blades according to claim 1, characterized in that: The base is provided with five inclined grooves and five inclined surfaces, and each inclined groove is equipped with a positioning tooth block, a bracket, a pressing plate and a tightening screw.

3. The electric spark tool for batch clamping turbine blades according to claim 1, characterized in that: The positioning tooth block is provided with two first positioning teeth. When the positioning tooth block is clamped on the turbine blade, the first positioning tooth at the front end cooperates with the fourth tenon tooth at the back arc end of the turbine blade for positioning, and the first positioning tooth at the rear end cooperates with the second tenon tooth at the back arc end of the turbine blade for positioning.

4. The electric spark tool for batch clamping turbine blades according to claim 1, characterized in that: When the pressure plate presses the turbine blade, the second positioning tooth of the pressure plate cooperates with the third tenon tooth at the inner arc end of the turbine blade for positioning. A pin hole and a clearance groove are provided in the middle of the pressure plate. The pin hole is used to pass the pin shaft. The clearance groove cooperates with the support ear at the front end of the bracket to install the middle part of the pressure plate in the notch of the bracket.

5. The electric spark tool for batch clamping turbine blades according to claim 1, characterized in that: The clamping screw can increase or decrease the number of rotations according to the wear of the parts in the electric spark tool, freely adjust the clamping force of the pressure plate, and realize the locking of the pressure plate to the turbine blade.

6. The electric spark tool for batch clamping turbine blades according to claim 1, characterized in that: Cylindrical pins are provided between the positioning tooth block and the inclined groove of the base, and between the bracket and the inclined groove of the base. The positioning tooth block is reliably positioned by the cylindrical pins, screws and the inclined groove of the base, and the bracket is reliably positioned and installed with the base by the screws and cylindrical pins.

7. A method for using an electric spark tool for batch clamping turbine blades, characterized in that: The following steps are involved: Step 1: Assemble an EDM tool for batch clamping turbine blades as described in any one of claims 1-6, first place the positioning tooth block and the bracket in each inclined groove of the base and fix them with screws and cylindrical pins, ensure that the positioning tooth block and the bracket are installed in place on the base through the cylindrical pins, screws and the inclined grooves of the base, then connect the pressure plate and the bracket through the pin shaft, screw the clamping screw into the threaded hole at the rear end of the pressure plate, and finally install the positioning pin on each inclined surface of the base; Step 2: Clean the work surface of the EDM forming machine, and then place the EDM tool. After placement, make sure that the parallelism between the horizontal surface of the EDM tool and the plane of the work surface and the verticality between the vertical surface of the EDM tool and the plane of the work surface are within the design range, and then use the electromagnet on the work surface to suck the base and securely fix the EDM tool; Step 3: Clamp the positioning rod on the EDM tool, determine the position of the reinforcement hole to be processed on each turbine blade by aligning the positioning rod, and input the coordinate values ​​corresponding to each hole in the CNC program; Step 4: Remove the positioning measuring rod, clamp the turbine blade on the electric spark tool, and face the inner arc end of the turbine blade upward. The fourth tenon and the second tenon on the back arc end of the turbine blade are respectively positioned with the first positioning teeth at the front and rear ends of the positioning tooth block to determine the clamping position of the turbine blade. After the positioning tooth block positions the turbine blade, rotate the clamping screw to drive the pressure plate to move downward. The second positioning tooth at the front end of the pressure plate presses the third tenon at the inner arc end of the turbine blade downward to position and clamp the turbine blade. The profile on one side of the tenon of the turbine blade contacts the head of the positioning pin to limit the left and right directions of the turbine blade. Step 5: Process the reinforcement holes one by one. Before processing the reinforcement holes, the verticality of the electrode rod needs to be calibrated to ≤0.01mm.

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