A nozzle ring vane profile hole line cutting clamp and processing method

Abstract

The nozzle ring vane type hole linear cutting processing clamp provided by the application comprises an inner ring and an outer ring, and a guide hole is arranged on the inner ring and the outer ring at the position of a vane type hole, so that the guide hole is parallel to the axial line of the vane type hole to be processed; before cutting processing, one end surface of a nozzle ring workpiece with the guide hole is tightly attached to an upright plate, the bottom of the workpiece is placed on two supporting rollers, the workpiece is rotated so that the guide hole corresponding to the vane type hole to be processed is located at the lowermost positioning pin supporting hole of the positioning mechanism opposite to the bottom, the positioning pin is passed through the guide hole on the inner ring and the guide hole on the outer ring from top to bottom, the bottom of the positioning pin is inserted into the positioning pin supporting hole, after ensuring that the positioning pin is in a vertical state, the nozzle ring workpiece to be processed is tightly pressed on the upright plate through a pressing plate, the positioning of the nozzle ring workpiece to be processed is completed, then the guide hole is taken as the cutting point of a linear cutting machine, a cutting metal wire is passed through the guide hole, and linear cutting processing of the vane type hole is performed.

Description

Technical Field

[0001] This invention relates to the field of nozzle ring machining technology, specifically to a fixture and machining method for wire cutting nozzle ring blade-shaped holes. Background Technology

[0002] Nozzle ring blades are a core component of turbochargers and a key technology for improving turbocharger efficiency. Machining the nozzle ring's airfoil profile is a crucial process for achieving stable nozzle ring blade assembly, forming stable air passages between blades, and ensuring adequate flow area. For example... Figure 1 The figure shows the turbocharger nozzle ring to be processed in this application, which includes an outer ring a1, an inner ring a2, and a flow channel a3 disposed between the outer and inner rings. Airfoil holes a4 are evenly distributed on the outer and inner rings where no flow channel is provided. The airfoil holes a4 on the inner ring a2 and outer ring a1 correspond one-to-one. Our existing process involves first machining the inner and outer ring features of the nozzle ring, then machining the airfoil holes for mounting the blades, and finally machining the nozzle ring blades. The nozzle ring blades (not marked in the figure) are generally blades with a uniform cross-section, and are mounted on the nozzle ring through airfoil holes a4 distributed on the inner and outer rings. Regarding the machining of the airfoil holes, the existing technology uses milling, but because the blade cross-section is small, milling the airfoil holes can lead to problems such as out-of-tolerance airfoil grooves and long machining times.

[0003] Some technicians have considered using molybdenum wire EDM to process the blade orifices. When using wire EDM, the blade orifice processing of the nozzle ring is mostly done on a piece-by-piece basis; that is, different models of nozzle rings have essentially the same structure, only the blade orifices differ. However, there are no standard fixtures for wire EDM of nozzle rings in the current technology. Most tooling fixtures are temporary fixtures pieced together by machining personnel based on their personal experience. Different machining personnel will design different fixtures to process different blade orifices, making it impossible to ensure machining accuracy. This easily leads to uneven distribution of blade orifices and makes it impossible to ensure that the axial line of each set of blade orifices meets the design accuracy requirements, resulting in a low yield rate. Summary of the Invention

[0004] To address the problem that existing wire EDM-based machining methods for nozzle annular blade orifices cannot guarantee machining accuracy, this invention provides a fixture for wire EDM machining of nozzle annular blade orifices, which can improve machining accuracy and yield. This application also discloses a method for wire EDM machining of nozzle annular blade orifices.

[0005] The structure of the present invention is as follows: a fixture for wire cutting of nozzle annular holes, characterized in that it comprises: a base, a vertical plate, a pressure plate, a support roller, a positioning pin, a guide hole, and a positioning structure;

[0006] The upright plate is mounted on the base in a manner perpendicular to the horizontal plane, and one side of the upright plate is set as the processing surface;

[0007] The pressure plate is disposed on one side of the machined surface of the vertical plate;

[0008] The support roller includes: a rotating shaft, a bearing, and a cylindrical roller, the roller being rotatably mounted on the rotating shaft based on the bearing; the rotating shaft is mounted on one side of the machined surface of the vertical plate in a manner perpendicular to the vertical plate;

[0009] The number of pressure plates is greater than one, and they are respectively set on the outer side of the outer ring and the inner side of the inner ring of the nozzle ring to be processed;

[0010] The support roller is horizontally symmetrically positioned below the nozzle ring to be processed, with the center of the nozzle ring as the point of symmetry.

[0011] The positioning structure is disposed below the supporting roller;

[0012] The positioning structure includes: a positioning pin support hole, the positioning pin support hole being perpendicular to the horizontal plane, and the diameter of the positioning pin support hole being adapted to the outer diameter of the positioning pin; the positioning pin is a cylindrical rod-shaped structure.

[0013] The guide hole is formed on the inner and outer rings of the nozzle ring, parallel to the axial line of the blade-shaped hole to be processed; the diameter of the guide hole is adapted to the outer diameter of the locating pin.

[0014] Its further features are:

[0015] The pressure plate includes: a pressure plate body and a pressure plate connecting bolt. The pressure plate body is arranged parallel to the vertical plate on one side of the machined surface of the vertical plate. A horizontal threaded hole for the pressure plate is opened on the vertical plate. The internal thread of the threaded hole for the pressure plate is adapted to the external thread of the pressure plate connecting bolt. The pressure plate connecting bolt passes through the pressure plate body and is threaded into the threaded hole for the pressure plate.

[0016] The pressure plate body has a through groove for the pressure plate along the length direction, and the pressure plate connecting bolt passes through the through groove for the pressure plate and is threaded into the threaded hole for the pressure plate.

[0017] The through groove of the pressure plate is located on the diameter of the nozzle ring to be processed;

[0018] The pressure plate shall be provided in a minimum of 4, with two located on the inner side of the inner ring and two located on the outer side of the outer ring;

[0019] The positioning structure also includes: a movable base, a support plate, a slider positioning screw, a slider positioning nut, and a horizontal slider;

[0020] A horizontal adjustment groove is provided on the upright plate, and the horizontal adjustment groove is located below the horizontal line connecting the two support rollers;

[0021] The size and shape of the movable seat are adapted to the horizontal adjustment groove, and the movable seat is disposed in the horizontal adjustment groove; the support plate is L-shaped, the vertical plate is mounted on the movable seat, and the horizontal plate is horizontally disposed on one side of the machined surface of the vertical plate;

[0022] The horizontal slider is T-shaped, and a vertical positioning pin support hole is provided on the vertical part of the horizontal slider; a positioning pin adjustment groove and a slider positioning groove perpendicular to the vertical plate are provided on the horizontal plate of the support plate; the vertical part of the T-shaped horizontal slider is inserted into the positioning pin adjustment groove; a slider positioning hole is provided on the horizontal part of the horizontal slider; the slider positioning screw passes through the slider positioning hole and the slider positioning groove from top to bottom, and is positioned by the slider positioning nut;

[0023] The positioning structure also includes: a limiting plate and positioning screws;

[0024] The movable seat is a wedge-shaped body with a trapezoidal interface, and its thickness on one side of the vertical plate is greater than the thickness on the other side of the vertical plate; the shape of the horizontal adjustment groove is a wedge-shaped groove adapted to the shape of the movable seat.

[0025] The limiting plate is located on the side of the vertical plate away from the processing surface, and the movable seat is movably inserted into the horizontal adjustment groove; the limiting plate 52 has an internal thread through hole, the movable seat 54 has an internal thread hole, and the positioning screw 53 is connected to both the internal thread hole and the internal thread through hole based on the thread.

[0026] A method for wire cutting nozzle annular orifices, characterized by comprising the following steps:

[0027] S1: On the nozzle ring to be processed, confirm the starting position and stopping position of the guide hole for the blade-shaped hole processing;

[0028] Using the two edges of the longer flow channel as a reference, draw a line parallel to the flow channel edge at a preset distance on the end face of the nozzle ring to be processed. These lines are recorded as the starting position line and the ending position line, respectively.

[0029] S2: Based on the starting position line and the ending position line, obtain the processing start position and the processing stop position on the outer ring surface of the nozzle ring to be processed;

[0030] S3: Using a four-axis horizontal machining center with indexing and positioning function, set the spindle indexing operation parameters according to the distribution position of the air-shaped holes to be processed, so that the machined guide hole is parallel to the axial line of the air-shaped hole to be processed.

[0031] S4: Install the positioning end face of the nozzle ring to be processed on the rotary table of the four-axis horizontal machine tool. After aligning the center, align the spindle of the machining center with the machining start position on the outer ring surface of the nozzle ring to be processed. Run and adjust the four-axis horizontal machining center with preset parameters until the final stop position of the spindle is aligned with the machining stop position, so as to obtain the blade guide hole position and the indexing parameters of the four-axis horizontal machine tool table that meet the design requirements.

[0032] S5: Based on the adjusted parameters, use a four-axis horizontal machining center to machine all the guide holes on the nozzle ring to be processed;

[0033] S6: Install the nozzle ring to be processed with the guide hole onto the wire EDM fixture; one end face of the nozzle ring to be processed is in close contact with the vertical plate, and the bottom of the workpiece is placed on two support rollers;

[0034] S7: Adjust the angle of the nozzle ring to be processed, pass the positioning pin through the two bottom guide holes and the positioning pin support hole at the same time, and ensure that the positioning pin is parallel to the cutting metal wire to complete the positioning of the nozzle ring to be processed.

[0035] S8: Remove the positioning pin, pass the wire cutting metal wire through the guide hole, and perform wire cutting of the leaf-shaped hole;

[0036] S9: Repeat steps S7~S8 until all leaf-shaped holes are machined.

[0037] This application provides a fixture for wire EDM machining of nozzle ring blade-shaped holes. First, guide holes are made on the inner and outer rings at the locations of the blade-shaped holes, making the guide holes parallel to the axial line of the blade-shaped hole to be machined. Before cutting, one end face of the nozzle ring workpiece with the guide holes is pressed tightly against a vertical plate, and the bottom of the workpiece is placed on two support rollers. The workpiece is rotated so that the guide hole corresponding to the blade-shaped hole to be machined is located at the bottom of the nozzle ring, directly opposite the positioning pin support hole in the bottom positioning mechanism. The positioning pin is then passed from top to bottom through the guide holes on the inner ring and the outer ring, with the bottom of the positioning pin inserted into the positioning mechanism. After ensuring the locating pin is vertical in the support hole, the nozzle ring workpiece to be processed is pressed onto the vertical plate by the pressure plate, thus completing the positioning of the nozzle ring workpiece. Then, the guide hole is used as the entry point of the wire EDM machine. The cutting wire is passed through the guide hole to perform wire EDM processing of the blade hole. By controlling the position of the complex blade hole through the relatively simple guide hole, the uniformity of the blade hole distribution is ensured. At the same time, wire EDM based on the guide hole can ensure that the axial line of the blade hole after wire EDM is parallel to the wire hole, improving the processing accuracy and thus improving the processing yield. Attached Figure Description

[0038] Figure 1 This is a three-dimensional structural diagram of the nozzle ring to be processed in this application;

[0039] Figure 2 A three-dimensional structural diagram of a fixture for wire EDM of nozzle annular orifices;

[0040] Figure 3 A structural schematic diagram of the non-machined side of the vertical plate;

[0041] Figure 4 Example of mounting a nozzle ring with a guide hole;

[0042] Figure 5 This is a three-dimensional structural diagram of the positioning structure;

[0043] Figure 6 A cross-sectional structural diagram of the sliding groove for the movable seat and horizontal adjustment;

[0044] Figure 7 A schematic diagram of the structure supporting the roller;

[0045] Figure 8 Examples of the start and stop position lines on the end face of the nozzle ring to be processed;

[0046] Figure 9 This is an example of a nozzle ring to be processed after machining. Detailed Implementation

[0047] like Figures 2-9As shown, this application includes a fixture for wire EDM of nozzle annular holes, comprising: a vertical plate 1, a base 2, a pressure plate 3, a support roller 4, a positioning pin 6, a guide hole 7, and a positioning structure 5. The vertical plate 1 is mounted on the base 2 in a manner perpendicular to the horizontal plane, and one side of the vertical plate 1 is configured as the machining surface.

[0048] like Figure 3 As shown, the pressure plate 3 includes: a pressure plate body 31 and a pressure plate connecting bolt 32. The pressure plate body 31 is arranged on one side of the machined surface of the vertical plate 1 in a manner parallel to the vertical plate 1.

[0049] A horizontal threaded hole 12 for the pressure plate is opened on the upright plate 1. The internal thread of the threaded hole 12 for the pressure plate is compatible with the external thread of the connecting bolt 32 for the pressure plate. The connecting bolt 32 for the pressure plate passes through the pressure plate body 31 and is threaded into the threaded hole for the pressure plate. The connecting bolt 32 for the pressure plate is a double-ended screw. It is tightened on the screw by the nut 35 for the pressure plate, so that the pressure plate 1 presses the nozzle ring to be processed, ensuring that the end face of the nozzle ring fits against the upright plate 1.

[0050] To ensure the nozzle ring to be processed is fixed to the vertical plate and remains stable during wire EDM, a minimum of four pressure plates 3 are installed: two inside the inner ring a2 and two outside the outer ring a1. The two pressure plates 3 inside the inner ring a2 are horizontally symmetrical about the center of the nozzle ring and simultaneously press against the end face of the inner ring. The two pressure plates 3 outside the outer ring are also horizontally symmetrical about the center of the nozzle ring and simultaneously press against the end face of the outer ring. Because the wire EDM operation is located at the lower part of the nozzle ring, the pressure plates 3 are also placed in the lower half of the nozzle ring.

[0051] To ensure that the pressure plate 3 is suitable for nozzle rings of various diameters, a through groove 33 for the pressure plate is formed along the diameter direction on the pressure plate body, and the through groove 33 for the pressure plate is located on the diameter of the nozzle ring to be processed. When positioning the nozzle ring to be processed, after placing the nozzle ring on the two support rollers 4, adjust the angle, and then adjust the position of the pressure plate body 31 based on the through groove 33 for the pressure plate, so that the pressure plate 3 on the inner side of the inner ring and the pressure plate 3 on the outer side of the outer ring can respectively press the inner and outer ring end faces of the nozzle ring. Then, the pressure plate connecting bolt 32 passes through the through groove 33 for the pressure plate and is threaded into the threaded hole 12 for the pressure plate, and is then fixed in position by the pressure plate nut 35. In actual operation, threaded holes 12 for the pressure plate can also be set on different diameter circumferences on the vertical plate 1, so that the pressure plate can be used for nozzle rings of more sizes to be processed, ensuring that the fixture of this application is more versatile.

[0052] like Figure 7As shown, the support roller 4 includes a rotating shaft 41, a bearing 42, and a cylindrical roller 43. The roller 43 is rotatably mounted on the rotating shaft 41 based on the bearing 42. The rotating shaft 41 is mounted perpendicular to the machining surface of the vertical plate 1. In specific applications, the rotating shaft 41 is fixed to the vertical plate 1 based on a hexagonal nut 44. To ensure stable support of the nozzle ring to be machined, two support rollers 4 are horizontally symmetrically arranged below the nozzle ring to be machined, with the center of the nozzle ring as the symmetrical point.

[0053] When the nozzle ring to be processed is pressed on the two support rollers 4 by its own weight, and the angle needs to be adjusted, the nozzle ring is rotated directly. The rollers 43 are made of stainless steel and rotate with the nozzle ring based on friction, so that the nozzle ring can be adjusted smoothly. This can effectively avoid the problem of damaging the outer ring surface of the nozzle ring during the adjustment of the nozzle ring angle.

[0054] like Figure 3 and Figure 5 As shown, the positioning structure 5 is located below the support roller 4; the positioning structure 5 includes: a support plate 51, a limiting plate 52, a positioning screw 53, a moving seat 54, a horizontal slider 55, a slider positioning screw 56, a slider positioning nut 59, and a positioning pin support hole 551.

[0055] The positioning pin support hole 551 is perpendicular to the horizontal plane, and the diameter of the positioning pin support hole 551 is adapted to the outer diameter of the positioning pin 6; the positioning pin 6 is a cylindrical rod-shaped structure.

[0056] A horizontal adjustment groove 11 is provided on the upright plate 1, and the horizontal adjustment groove 11 is located below the horizontal line connecting the two support rollers 4.

[0057] The size and shape of the movable seat 54 are adapted to the horizontal adjustment groove 11, and the movable seat 54 is set in the horizontal adjustment groove 11; the support plate 51 is L-shaped, the vertical plate is mounted on the movable seat 54 based on the fixing screw 511, and the horizontal plate is horizontally set on one side of the machined surface of the vertical plate 1.

[0058] The horizontal slider 55 is T-shaped, and a vertical positioning pin support hole 551 is provided on the vertical part of the horizontal slider 55. A positioning pin adjustment groove 57 and a slider positioning groove 58 perpendicular to the vertical plate 1 are provided on the horizontal plate of the support plate 51. The vertical part of the T-shaped horizontal slider 55 is inserted into the positioning pin adjustment groove 57. A slider positioning hole is provided on the horizontal part of the horizontal slider 55. The slider positioning screw 56 passes through the slider positioning hole and the slider positioning groove 58 from top to bottom, and the relative position of the horizontal slider 55 and the support plate 51 is positioned by the slider positioning nut 59. Based on the cooperation between the horizontal slider 55 and the slider positioning groove 58, this application can be applied to nozzle rings with different widths of the outer and inner ring end faces. If the nozzle ring is narrow, the horizontal slider 55 drives the positioning pin support hole 551 to move towards the vertical plate 1. If the nozzle ring is wide, the horizontal slider 55 drives the positioning pin support hole 551 to move away from the vertical plate 1, ensuring that the fixture of this application is more versatile.

[0059] In this embodiment, the positioning pin support hole 551 is opened on the vertical part of the horizontal slider 55, so that the positioning pin support hole 551 has a certain depth, ensuring that if the guide hole 7 on the inner ring and the outer ring deviates from the angle of the positioning pin support hole 551, the positioning pin 6 cannot be inserted into the positioning pin support hole 551.

[0060] To achieve the relative positioning of the horizontal slider 55 and the vertical plate 1, in this application, the movable seat 54 is a wedge-shaped body with a trapezoidal cross-section, and the horizontal adjustment groove 11 is a wedge-shaped groove adapted to the structure of the movable seat 54. Figure 6 As shown, the thickness of the movable seat 54 on one side of the machined surface of the upright plate 1 (the side connected to the support plate 51) is greater than the thickness of the other side of the upright plate 1. The movable seat 54 is in the sliding groove 11 for horizontal adjustment, while the limiting plate 52 is set on the side of the upright plate 1 away from the machined surface. The limiting plate 52 has an internally threaded through hole, and the movable seat 54 has an internally threaded hole. The positioning screw 53 is connected to both the internally threaded hole and the internally threaded through hole based on the thread. In this embodiment, the positioning screw 53 is a round-headed hexagonal socket screw.

[0061] After the movable seat 54, carrying the horizontal slider 55, slides along the horizontal adjustment groove 11 to the appropriate position, tighten the positioning screw 53. During the tightening process, the movable seat 54 will be driven by the positioning screw 53 to move towards the limiting plate 52. Because the movable seat 54 is a wedge-shaped block and the horizontal adjustment groove 11 is a wedge-shaped groove, the movable seat 54 will press against the horizontal adjustment groove 11 during the movement, fixing the relative position of the horizontal slider 55 and the vertical plate 1. When it is necessary to adjust the position of the horizontal slider 55 in the horizontal adjustment groove 11, the positioning screw 53 is turned in the opposite direction. After the movable seat 54 moves to the appropriate position away from the limiting plate 52, the movable seat 54 can move laterally in the horizontal adjustment groove 11 with the horizontal slider 55, making the fixture of this application more versatile.

[0062] Before wire EDM machining of the nozzle ring blade-shaped hole, the universal fixture for wire EDM machining of the nozzle ring blade-shaped hole described in this application is installed on the worktable of the wire EDM equipment. The nozzle ring is placed on the two sets of support rollers 4, so that one end face of the nozzle ring is in contact with the vertical plate 1. The pressure plate 3 is adjusted to press the nozzle ring to be machined, and the nozzle ring is initially fixed. According to the left and right offset distance of the blade-shaped hole guide hole, the translational moving seat 54 is adjusted and the positioning screw 53 is locked. According to the distance between the blade-shaped hole and the end face of the nozzle ring, the position of the horizontal slider 55 is adjusted and the slider positioning screw 56 is locked. The guide hole 7 in the nozzle ring is adjusted to a vertical state, the positioning pin 6 is inserted, and the translational moving seat 54 and the horizontal slider 55 are finely adjusted to achieve final positioning. The pressure plate nut 35, the positioning screw 53 and the slider positioning screw 56 on the pressure plate 3 are fixed again to complete the final positioning of the pressure plate 3, the moving seat 54 and the horizontal slider 55.

[0063] The wire-cut molybdenum wire is passed through the guide hole 7 to perform wire cutting of the blade-shaped hole; after the first blade-shaped hole is processed, the nut 35 of the pressure plate is loosened, the nozzle ring to be processed is rotated so that the guide hole of the next blade-shaped hole is in a vertical state, the positioning pin 6 is inserted and the positioning is checked, and the nut 35 of the pressure plate is tightened to achieve the positioning of the next blade-shaped hole.

[0064] The wire EDM fixture designed in this application is a general-purpose fixture that can be applied to the machining of nozzle rings with a wider range of diameters. The rolling assembly and the blade hole position adjustment mechanism mounted on the base can meet the positioning requirements of adjusting the eccentricity and end face distance of the guide hole of the blade hole for nozzle rings of different sizes, thereby achieving wire EDM positioning of the blade hole and ensuring smooth movement during continuous machining of the blade hole. This demonstrates the versatility of the wire EDM fixture for nozzle ring blade holes.

[0065] The machining method based on the above-mentioned fixture for wire EDM of nozzle annular holes includes the following steps.

[0066] In this application, the guide hole 7 is formed on the inner ring a2 and outer ring a1 of the nozzle ring, parallel to the axial line of the blade-shaped hole to be machined; the diameter of the guide hole 7 is adapted to the outer diameter of the locating pin 6. The guide hole 7 is machined before wire cutting.

[0067] S1: On the nozzle ring to be processed, confirm the starting position and stopping position of the guide hole 7 for the blade-shaped hole processing;

[0068] like Figure 8 As shown, using the two edges of the longer flow channel as references, lines parallel to the flow channel edge are drawn at preset distances on the end face of the nozzle ring to be processed, moving away from the flow channel edge. These lines are denoted as the starting position line and the ending position line, respectively. In this embodiment, the starting position line is offset outward by d1 = 5mm from one edge of the longer flow channel a3 (marked by the red line in the figure), which is the starting position marked by the blue line. The ending position line is offset outward by d2 = 8mm from the other edge of the longer flow channel a3 (marked by the red line in the figure), which is the ending position marked by the blue line. The specific values ​​of d1 and d2 are set according to the processing requirements.

[0069] The smaller flow channel a3 is set as the non-processing position. Similarly, the two ends of the smaller flow channel a3 (marked by the red line in the figure) are offset outward by d3=6.41mm and d4=6.41mm respectively, to obtain the two non-processing position start line and end line marked by the blue line.

[0070] S2: Based on the starting position line and the ending position line, obtain the machining start position and machining stop position on the outer ring surface of the nozzle ring to be machined.

[0071] In practice, since the end face of the nozzle ring to be processed is perpendicular to the outer ring surface, the starting position and the stopping position can be drawn on the outer ring surface using an L-shaped square based on the starting position line and the stopping position line, respectively.

[0072] S3: Using a four-axis horizontal machining center with indexing and positioning function, set the spindle indexing operation parameters according to the distribution position of the blade-shaped holes to be machined, so that the machined guide hole 7 is parallel to the axial line of the blade-shaped holes to be machined.

[0073] In the online cutting process of this application, the nozzle ring to be processed is positioned by the guide holes 7 on the inner and outer rings and the positioning pins 6. Therefore, it is essential to ensure the accuracy of the position of the guide holes 7. In this application, the guide holes are machined using a four-axis horizontal machining center equipped with an indexing rotary table, which can effectively improve the positional accuracy of the guide holes. Commonly used four-axis horizontal machining centers with indexing and positioning functions, such as the Niigata four-axis horizontal machining series from Japan and the Jingyan series from Taiwan, China, can meet the processing requirements of this application.

[0074] In practice, the accuracy of the position of the guide hole 7 can be determined by measuring the distance between two adjacent guide holes 7 on the outer ring surface.

[0075] S4: Install the positioning end face of the nozzle ring to be processed on the rotary table of the four-axis horizontal machine tool. After aligning the center, align the spindle of the machining center with the machining start position on the outer ring surface of the nozzle ring to be processed. Run and adjust the four-axis horizontal machining center with preset parameters until the final stop position of the spindle is aligned with the machining stop position, so as to obtain the position of the blade guide hole 7 and the indexing parameters of the four-axis horizontal machine tool table that meet the design requirements.

[0076] In practice, one end face of the nozzle ring to be processed is placed on the rotary table of a four-axis horizontal machine tool as the positioning surface to find the center. The machine tool spindle is aligned with the starting position of the airfoil guide hole and the marking line is drawn. With the starting marking line as the initial position, the worktable is rotated according to the preset indexing machining parameters to check the marking line at the end position of the airfoil guide hole. If the spindle is aligned with the marking line at the end position of the airfoil guide hole, it can be verified that the position of the airfoil guide hole is correct and the indexing rotation of the four-axis horizontal machine tool worktable is correct.

[0077] In this application, the accuracy of the machining parameters of a four-axis horizontal machine tool is determined by setting the machining start position and machining stop position on the outer ring surface of the nozzle to be machined. The specific method for achieving indexing machining using a four-axis horizontal machine tool is based on existing technology.

[0078] S5: Based on the adjusted parameters, use a four-axis horizontal machining center to machine all the guide holes 7 on the nozzle ring to be processed.

[0079] After verification, all airfoil guide holes are machined into place according to the CNC program to ensure uniform distribution of airfoil holes.

[0080] S6: Install the nozzle ring to be processed with the guide hole 7 onto the wire EDM fixture; one end face of the nozzle ring to be processed is in close contact with the vertical plate 1, and the bottom of the workpiece is placed on the two support rollers 4.

[0081] The wire cutting equipment used in this application is a medium-sized wire cutting machine, such as the automatic wire feeding machine from Suzhou Sanguang Technology, which can meet the processing requirements. In this embodiment, molybdenum wire is used as the metal wire for cutting.

[0082] S7: Adjust the angle of the nozzle ring to be processed, and pass the positioning pin 6 through the two bottom guide holes 7 and the positioning pin support hole 551 at the same time. Ensure that the positioning pin 6 is parallel to the cutting metal wire to complete the positioning of the nozzle ring to be processed.

[0083] During processing, one end face of the nozzle ring to be processed is attached and fixed to the vertical plate of the wire EDM universal fixture. Ensure that the direction of the guide pin 7 is parallel to the molybdenum wire. Insert the guide pin 7 into the blade guide hole 6 to ensure that the axial line of the blade hole after wire EDM is parallel to the wire hole.

[0084] S8: Remove the positioning pin 6, pass the wire cutting metal wire through the guide hole 7, and perform wire cutting of the leaf-shaped hole.

[0085] After the previous blade-shaped hole is processed, the pressure plate 3 is released from the end face of the nozzle ring, the nozzle ring to be processed is rotated and placed on the support roller 4, and the guide pin 7 is inserted into the next guide hole 6. Based on the completed positioning of the guide hole 6, the next blade-shaped hole is processed, thereby realizing the wire cutting of the blade-shaped hole.

[0086] S9: Repeat steps S7-S8 until all airfoil holes are machined. The machined airfoil holes are as follows: Figure 9 As shown.

[0087] Using the technical solution of this application can effectively solve the problems of excessive tolerance in the blade profile of nozzle ring blade hole machining, uneven distribution, and non-parallelism between the blade hole guide and the blade hole axial line, and can effectively improve the machining yield.

Claims

1. A fixture for wire EDM of nozzle annular blade type holes, characterized in that, It includes: Base, upright plate, pressure plate, support roller, positioning pin, guide hole and positioning structure; The upright plate is mounted on the base in a manner perpendicular to the horizontal plane, and one side of the upright plate is set as the processing surface; The pressure plate is disposed on one side of the machined surface of the vertical plate; The support roller includes: a rotating shaft, a bearing, and a cylindrical roller, the roller being rotatably mounted on the rotating shaft based on the bearing; the rotating shaft is mounted on one side of the machined surface of the vertical plate in a manner perpendicular to the vertical plate; The number of pressure plates is greater than one, and they are respectively set on the outer side of the outer ring and the inner side of the inner ring of the nozzle ring to be processed; The support roller is horizontally symmetrically positioned below the nozzle ring to be processed, with the center of the nozzle ring as the point of symmetry. The positioning structure is disposed below the supporting roller; The positioning structure includes: a positioning pin support hole, the positioning pin support hole being perpendicular to the horizontal plane, and the diameter of the positioning pin support hole being adapted to the outer diameter of the positioning pin; the positioning pin is a cylindrical rod-shaped structure. The guide hole is formed on the inner and outer rings of the nozzle ring, parallel to the axial line of the blade-shaped hole to be processed; the diameter of the guide hole is adapted to the outer diameter of the locating pin. The pressure plate includes: a pressure plate body and a pressure plate connecting bolt. The pressure plate body is arranged parallel to the vertical plate on one side of the machined surface of the vertical plate. A horizontal threaded hole for the pressure plate is opened on the vertical plate. The internal thread of the threaded hole for the pressure plate is adapted to the external thread of the pressure plate connecting bolt. The pressure plate connecting bolt passes through the pressure plate body and is threaded into the threaded hole for the pressure plate. The positioning structure also includes: a movable base, a support plate, a slider positioning screw, a slider positioning nut, and a horizontal slider; A horizontal adjustment groove is provided on the upright plate, and the horizontal adjustment groove is located below the horizontal line connecting the two support rollers; The size and shape of the movable seat are adapted to the horizontal adjustment groove, and the movable seat is disposed in the horizontal adjustment groove; the support plate is L-shaped, the vertical plate is installed on the movable seat, and the horizontal plate is horizontally disposed on one side of the machined surface of the vertical plate; The horizontal slider is T-shaped, and a vertical positioning pin support hole is provided on the vertical part of the horizontal slider; a positioning pin adjustment groove and a slider positioning groove perpendicular to the vertical plate are provided on the horizontal plate of the support plate; the vertical part of the T-shaped horizontal slider is inserted into the positioning pin adjustment groove; a slider positioning hole is provided on the horizontal part of the horizontal slider; the slider positioning screw passes through the slider positioning hole and the slider positioning groove from top to bottom, and is positioned by the slider positioning nut; The positioning structure also includes: a limiting plate and positioning screws; The movable seat is a wedge-shaped body with a trapezoidal cross-section, and its thickness on one side of the vertical plate is greater than the thickness on the other side of the vertical plate; the shape of the horizontal adjustment groove is a wedge-shaped groove adapted to the shape of the movable seat. The limiting plate is located on the side of the vertical plate away from the processing surface, and the movable seat is movably inserted into the horizontal adjustment groove; the limiting plate has an internal thread through hole, the movable seat has an internal thread hole, and the positioning screw is connected to both the internal thread hole and the internal thread through hole based on the thread.

2. The fixture for wire EDM of nozzle annular holes according to claim 1, characterized in that: The pressure plate body has a through groove along its length, and the pressure plate connecting bolt passes through the through groove and is threaded into the threaded hole of the pressure plate.

3. The fixture for wire EDM of nozzle annular holes according to claim 2, characterized in that: The through groove of the pressure plate is located on the diameter of the nozzle ring to be processed.

4. The fixture for wire EDM of nozzle annular holes according to claim 1, characterized in that: The pressure plate is provided in a minimum of 4 units, with two units located on the inner side of the inner ring and two units located on the outer side of the outer ring.

5. A method for wire cutting nozzle annular holes based on the fixture for wire cutting of nozzle annular holes as described in any one of claims 1 to 4, characterized in that, It includes the following steps: S1: On the nozzle ring to be processed, confirm the starting position and stopping position of the guide hole for the blade-shaped hole processing; Using the two edges of the longer flow channel as a reference, draw a line parallel to the edge of the flow channel at a preset distance on the end face of the nozzle ring to be processed. These lines are recorded as the starting position line and the ending position line, respectively. S2: Based on the start position line and the end position line, obtain the processing start position and the processing stop position on the outer ring surface of the nozzle ring to be processed; S3: Using a four-axis horizontal machining center with indexing and positioning function, set the spindle indexing operation parameters according to the distribution position of the air-shaped holes to be processed, so that the machined guide hole is parallel to the axial line of the air-shaped hole to be processed. S4: Install the positioning end face of the nozzle ring to be processed on the rotary table of the four-axis horizontal machine tool. After aligning the center, align the spindle of the machining center with the machining start position on the outer ring surface of the nozzle ring to be processed. Run and adjust the four-axis horizontal machining center with preset parameters until the final stop position of the spindle is aligned with the machining stop position, so as to obtain the blade guide hole position and the indexing parameters of the four-axis horizontal machine tool table that meet the design requirements. S5: Based on the adjusted parameters, use a four-axis horizontal machining center to machine all the guide holes on the nozzle ring to be processed; S6: Install the nozzle ring to be processed with the guide hole onto the wire EDM fixture; one end face of the nozzle ring to be processed is in close contact with the vertical plate, and the bottom of the workpiece is placed on two support rollers; S7: Adjust the angle of the nozzle ring to be processed, pass the positioning pin through the two bottom guide holes and the positioning pin support hole at the same time, and ensure that the positioning pin is parallel to the cutting metal wire to complete the positioning of the nozzle ring to be processed. S8: Remove the positioning pin, pass the wire cutting metal wire through the guide hole, and perform wire cutting of the leaf-shaped hole; S9: Repeat steps S7~S8 until all leaf-shaped holes are machined.

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