Efficient processing method and device for thin-wall conical-spherical fairing crescent groove

Abstract

The application discloses a kind of thin-walled conical surface fairing crescent groove high-efficiency processing method and device, device includes the lower mould with crescent groove, the upper mould with crescent blade, positioning pin, stud, open washer and nut.Adopting punching mode to process crescent groove on fairing, punch one each time, when punching, the axis of fairing and vertical direction forms an angle, the angle ensures that the punching direction is consistent with the projection direction of crescent groove on fairing, with round hole positioning to ensure circumferential position, the middle part of crescent groove on fairing is used as mould punching center, and the normal direction of conical surface generatrix at this place is the direction of mould punching.The processing method of the application is matched with processing device, solves the problem that section ablation layer is difficult to remove and processing efficiency is low caused by laser and electric processing of thin-walled curved surface narrow groove, avoids the problem that milling tool is greatly worn and difficult to cut, the quality of crescent groove punching section is good, the force of punching device is uniform, and high-efficiency and rapid processing is realized.

Description

Technical Field

[0001] This invention belongs to the field of aero-engine main combustion chamber component processing technology, specifically the process method and apparatus for processing thin-walled curved irregular groove features. Background Technology

[0002] The deflector is a key component of the flame tube vortex generator. The vortex generator is composed of the deflector, the ball head seat, and multiple evenly distributed swirl vanes on the surface of the deflector. The vortex generator is welded to the head shell to form the flame tube head with the vortex generator. It is used to install the main pipe fuel injector of the combustion chamber. While being installed and fixed, it introduces the low-temperature gas outside the flame tube into the inner area of ​​the head to cool the main pipe fuel injector, reduce the temperature around the fuel injector, and improve the working reliability of the fuel injector.

[0003] The large end of the fairing is conical, transitioning to a spherical shape in the middle, and the bottom is a cylindrical sheet metal part (such as...). Figure 1 This part is made of high-temperature alloy sheet with a wall thickness of 1mm, which is cut off after multiple deep drawing processes. On the spherical surface of the deflector, multiple normal circular holes are evenly distributed around the cylindrical axis. On the spherical and conical walls, multiple crescent grooves are evenly distributed around the circular holes. On the normal direction of the conical surface at the same position as the circular holes, the center line of the crescent groove is an arc and a tangent straight line. The two sides of the groove are curves offset from the center line to both sides, with an offset distance of less than 1mm. The two ends of the groove are tangent to the offset lines on both sides by arcs, and the center of the arc is the two endpoints of the center line. One end of the arc in the centerline is located on the right side of the circular hole and close to the spherical region of the fairing, while the other end of the tangent is located on the left side of the circular hole and close to the large end region of the conical surface of the fairing. The lower end of the tangent is projected onto the tangential plane at a certain distance L1 from the central axis of the fairing, and the tangent forms a certain angle α with the central axis of the fairing. The distance between the right end of the arc segment of the crescent groove centerline and the left end of the tangent segment is L. The actual contour boundary of the crescent groove is the intersection boundary formed by the outer curve of the groove along the normal of the plane, running from the outside to the inside of the fairing surface. The arc segment of the crescent groove spans the spherical and conical surfaces, while the straight segment of the crescent groove is located on the conical surface of the fairing.

[0004] A set of circular holes concentric with the cylinder are distributed on the spherical wall of the deflector. The center line of the circular holes is at a fixed angle to the axis of the cylinder. The number of circular holes is the same as the number of crescent grooves.

[0005] The circumferential position of the crescent groove is based on the size of the round hole. The crescent groove and the round hole have a certain positional relationship. Therefore, the machining of the crescent groove uses the round hole as the positioning reference to ensure the correct position of the round hole, the crescent groove and the shape of the guide shield.

[0006] For holes and grooves in thin-walled curved sheet metal parts, common processing methods include laser cutting, electrical discharge machining (EDM), and milling. However, laser cutting and EDM leave an ablation layer on the groove wall, which is particularly difficult to remove in narrow grooves, affecting weld quality during subsequent welding. Furthermore, these methods are inefficient and costly. Because crescent grooves are very narrow and curved, milling tools are prone to wear and breakage, resulting in long processing cycles, low efficiency, and difficulty in meeting batch processing requirements.

[0007] For the reasons mentioned above, it is necessary to develop an efficient machining method to achieve rapid, accurate, and efficient machining of the crescent groove while maintaining the correct positional relationship with the circular hole. Summary of the Invention

[0008] The present invention aims to provide a method and apparatus for efficient machining of crescent grooves on thin-walled conical spherical guide fairings, thereby achieving efficient machining of crescent grooves on thin-walled curved surfaces and solving technical problems such as difficulty in removing the ablation layer of the cross section, low machining efficiency, large wear of milling tools, and difficulty in cutting caused by laser and electrical discharge machining of narrow grooves on thin-walled curved surfaces.

[0009] To achieve the above objectives, the present invention adopts the following technical solution: A high-efficiency machining device for the crescent groove of a thin-walled conical spherical guide shield includes: The lower mold mainly consists of a base and a positioning surface. The base is a truncated pyramid, which includes a first side, a second side, a third side perpendicular to the bottom surface, and a fourth side at an acute angle to the bottom surface. The positioning surface is located on the fourth side surface and includes a cylindrical surface, a spherical surface, and a conical surface tangent to the spherical surface and concentric with the cylindrical surface, connected in sequence. The conical surface is connected to the fourth side surface, and there is an annular groove between the conical surface and the fourth side surface. A threaded hole is opened on the axial end face of the cylindrical surface away from the fourth side surface. The generatrix length of the cylindrical surface is... The length of the cylindrical surface is less than the length of the cylindrical surface of the fairing, and the generatrix length of the conical surface is greater than the generatrix length of the conical surface of the fairing. The shape and other dimensions of the cylindrical surface, spherical surface and conical surface are consistent with the inner surface of the fairing. A lower die cutting edge that meets the shape and size requirements of the crescent groove of the fairing is provided along the direction perpendicular to the bottom surface of the truncated pyramid and directly above the spherical surface and the conical surface. The height of the lower die cutting edge extends downward along the surface. Below the lower die cutting edge is a material leakage hole that can contain the lower die cutting edge. Below the spherical surface is a cylindrical hole for inserting a pin that corresponds to the lower die cutting edge. The upper die includes an upper die cutting edge whose shape and size conform to the crescent groove of the fairing; The stud has external threads on both its first axial end surface and its second axial end surface, wherein the second axial end of the stud is connected to the threaded hole on the axial end surface of the cylindrical surface of the lower die. A nut, which is connected to the first axial end of a stud; An open washer, the open washer including an open long groove that extends through the thickness of the open washer, the open washer being disposed between the nut and the cylindrical axial end face of the guide shield, the width of the open long groove being greater than the outer diameter of the stud; A positioning pin is inserted into a cylindrical hole below the spherical surface of the lower mold, and at least one section of the positioning pin has an outer diameter equal to the diameter of the circular hole on the flow guide.

[0010] As one possible solution: the lower end of the base of the lower mold is connected to a cube, and the side length of the cube is greater than the maximum bottom side length of the base of the corresponding quadrangular frustum of the base.

[0011] As one option: the upper mold further includes a cube block, which is located above the cutting edge of the upper mold, and the cube block and the cutting edge of the upper mold are connected by a cuboid that encompasses the crescent-shaped cutting edge.

[0012] A high-efficiency machining method for the crescent groove of a thin-walled conical spherical air guide includes: The crescent groove is machined on the fairing by punching. One crescent groove is punched at a time. During punching, the axis of the fairing forms an angle with the vertical direction. This angle ensures that the punching direction is consistent with the projection direction of the crescent groove on the fairing. The circumferential position is ensured by positioning with a circular hole. The middle part of the crescent groove on the fairing is used as the punching center of the mold, and the normal direction of the generatrix of the conical surface at this point is the punching direction of the mold.

[0013] Furthermore, the high-efficiency machining method for the crescent groove of the thin-walled conical spherical guide shield employs the aforementioned high-efficiency machining device and includes: Step 1: Use a pressure plate to fix the upper die to the upper platform of the punch press, and use a pressure plate to fix the lower die to the lower platform of the punch press. Check and adjust the upper and lower dies to ensure that the gap between the cutting edge of the upper die and the periphery of the cutting edge of the lower die is uniform. Step 2: Install the flow guide with evenly distributed round holes onto the positioning surface of the lower mold, rotate the flow guide and align any one of the round holes with the cylindrical hole below the spherical surface of the lower mold, and insert the positioning pin. Step 3: Align the open slot of the open washer with the stud, press the end face of the open washer against the end face of the guide cylinder, and screw the nut and stud together until the guide is pressed tightly against the positioning surface of the lower mold. Step 4: Start the punch press. The upper die moves downward under the action of the upper platform. The cutting edge of the upper die cuts off the material on the wall of the guide shroud until it enters the cutting edge of the lower die. The cut-off waste is discharged along the material discharge hole of the lower die. Step 5: The upper mold moves up with the upper platform, loosen the nut, remove the open washer, and pull out the positioning pin; Step 6: Move the guide shield a certain distance away from the lower mold positioning surface, then rotate the guide shield counterclockwise. When the other round hole on the guide shield is aligned with the cylindrical hole below the spherical surface of the lower mold, insert the positioning pin again. Step 7: Repeat steps 3 through 6 to complete the punching of all crescent-shaped grooves.

[0014] Compared with existing technologies, this invention proposes an efficient processing method and apparatus for machining crescent grooves on the surface of thin-walled conical spheres in sheet metal. Its innovation lies in the fact that after process analysis of the dimensions, orientation, position, and boundary contour lines formed by the narrow grooves on the curved surface, a highly efficient and reliable cutting method is designed. The implementation of this method greatly improves the machining efficiency of the parts, and the position of the narrow grooves on the parts is accurate, ensuring the relative positional relationship between the crescent grooves and the circular holes, providing accurate and reliable positioning for subsequent welding of guide vanes.

[0015] The processing apparatus and method of the present invention ensure that the narrow groove punching cut surface of the part has good quality and the mold is subjected to uniform force, thus achieving the requirements of high-efficiency and rapid processing. It solves the technical problems of high cost and inability to remove the ablation layer in laser and EDM feature processes, and also avoids the efficiency and cost problems caused by the small size of milling tools, low cutting efficiency, and especially the easy breakage of small-sized tools.

[0016] The processing apparatus and processing method of the present invention can also be extended to the field of processing thin-walled components with curved surfaces, and have great application value and promotion significance. Attached Figure Description

[0017] Figure 1 This is a drawing of the fairing part to be processed in this invention; Figure 2 An exploded view of the high-efficiency processing device (punching die) for the fairing; Figure 3 This is a sectional view of the lower mold; Figure 4 This is a top view of the lower mold; In the diagram: 1—Nut; 2—Open washer; 3—Diffuser; 4—Stud; 5—Positioning pin; 6—Upper mold; 7—Lower mold. Detailed Implementation

[0018] The present invention will be further described below with reference to specific embodiments, but it should not be construed as limiting the scope of the subject matter of the present invention to the following embodiments. All modifications, substitutions and alterations made based on ordinary technical knowledge and common practices in the art without departing from the above-described technical concept of the present invention are included within the scope of the present invention.

[0019] The efficient processing method and apparatus for the crescent groove of the thin-walled conical spherical guide shield in this invention combines, for example, the following Figure 1 The structural features of the flow guide shroud 3 shown are obtained through a comprehensive analysis of the shape and distribution area of ​​the crescent groove, groove size, and technical requirements.

[0020] See Figure 1The crescent groove of the flow guide 3 spans both spherical and conical surfaces in the axial direction, and is located within a 30° range in the axial direction. Therefore, the shape of the crescent groove is distributed in a spatial curve on the wall surface. During processing, it is difficult to achieve synchronous force at the edge of the crescent groove. As a result, the uneven load on the part during processing can easily lead to the breakage of the thin punch cutting edge. According to the product requirements, the cutting edge structure for punching is designed in the projection direction of the crescent groove size to determine the feasibility of using a punching die for processing. The force on the cutting edge during the punching process is analyzed in order to understand the punch strength of the crescent groove processing method and the part's ability to withstand uneven load.

[0021] In addition, there are axial and circumferential positional relationships between the uniformly distributed crescent grooves and the uniformly distributed circular holes. When designing the punching process, it is necessary to consider not only the punching feasibility of the crescent grooves, but also the precise control of their positioning. Through the analysis of the shape and size of the parts, combined with the design of the structural function of the punching die, a punching processing method with spherical surface centering, cylindrical limit at the bottom of the spherical surface, and angular positioning of the uniformly distributed circular holes is proposed.

[0022] The punching process for thin-walled curved surfaces with narrow crescent grooves involves rotating the crescent groove of the guide shield with conical and spherical surfaces to a vertical direction, depending on the product's dimensional orientation, such as... Figure 4 The middle part of the crescent groove on the guide cover (i.e. the midpoint of the center line of the crescent groove) is used as the punching center of the mold, and the normal direction of the generatrix of the conical surface at this point is the punching direction of the mold. In this way, the cross section of the punched convex surface can be consistent with the cross section of the crescent groove design drawing, which can effectively ensure that the punching shape meets the dimensional requirements of the part design.

[0023] During punching, the axis of the fairing 3 is made at an angle to the vertical direction (i.e., the normal direction of the generatrix of the conical surface on the fairing 3 is vertical, see [reference]). Figure 3 and Figure 4 This included angle ensures that the punching direction is consistent with the projection direction of the crescent groove on the fairing (at this time, the punching direction is consistent with the direction of the generatrix normal of the conical surface on the fairing 3, correctly reflecting the formation method of the crescent groove on the fairing 3, see the background technology section, and...). Figure 1 (The dimensions and positions are consistent), the circumferential position is ensured by the circular hole positioning, the middle part of the crescent groove on the guide cover is used as the punching center of the mold, and the normal direction of the generatrix of the conical surface at this point is the punching direction of the mold.

[0024] The crescent-shaped groove punching die uses a cylindrical stop at the bottom of a spherical surface, with evenly distributed circular holes for angular positioning. The cylindrical end face is used for clamping, ensuring the stability and reliability of the part during the punching process and preventing the upper die (punch) from breaking due to part movement under stress. To improve part clamping efficiency, the end face of the cylindrical surface at the bottom of the spherical surface is clamped using a combination of an open washer 2 and a nut 1. The open washer 2 is connected to the positioning surface via a central stud 4, pressing the guide shield 3 onto the spherical and conical surfaces that meet the lower die cutting edge. During processing, a positioning pin 5 is inserted at the opposite circular hole position of each crescent groove to ensure accurate positioning of the crescent groove and the circular hole. After punching one crescent groove, the positioning pin 5 is removed, the nut 1 is loosened, the guide shield 3 is rotated 30°, the positioning pin 5 is reinserted into the positioning hole, the open washer 2 is placed on the end face, and the nut 1 is tightened to begin the next punching process. This process is repeated until all crescent grooves are punched.

[0025] This embodiment provides an efficient machining method for thin-walled curved crescent grooves and a punching die for machining the flow guide 3. The machining process of the crescent groove is as follows: 1. First, design a high-efficiency processing device for crescent grooves, namely a crescent groove punching die, such as... Figures 2-4 The punching die consists of a lower die 7 with a crescent-shaped lower cutting edge, an upper die 6 with a crescent-shaped upper cutting edge, a positioning pin 5, a stud 4, an open washer 2, a nut 1, and other parts. 1.1 The lower die 7 consists of a cylindrical surface, a spherical surface, and a conical surface tangent to the spherical surface and concentric with the cylinder for positioning. Its shape and dimensions conform to the inner surface of the fairing. The cylinder has a threaded hole at its center. The length of the cylindrical surface is less than the length of the fairing, and the length of the conical surface is greater than the conical surface of the fairing. The common axis of the cylindrical and conical surfaces is at a specified angle to the horizontal plane. The bottom of the conical surface is connected to a prism (truncated pyramid) with one side at a fixed angle to the horizontal plane and the other three sides perpendicular to each other and to the horizontal plane. The bottom of the prism is a cube of a certain thickness, and the boundary dimensions of the cube are greater than the boundary dimensions of the prism. Directly above the spherical and conical surfaces, a lower die cutting edge conforming to the shape and size requirements of the crescent groove of the fairing is provided. The height of the lower die cutting edge is 5mm along the surface (e.g., ...). Figure 3 The lower die cutting edge extends 5mm from the outside in along the projection direction of the cutting edge on the spherical and conical surfaces where the crescent groove is located. Below the lower die cutting edge is a rectangular discharge hole that can contain the cutting edge for discharging punching waste. A cylindrical hole corresponding to the crescent groove is provided on the spherical surface below the lower die 7 for inserting the positioning pin 5 during punching.

[0026] 1.2 The upper mold 6 has an upper mold cutting edge with a shape and size that matches the crescent groove of the fairing and a certain height. Above the upper mold 6 is a cube block of a certain thickness. The upper mold cutting edge and the cube block above are connected by a small cuboid that contains the crescent-shaped cutting edge.

[0027] 1.3. The stud 4 is a cylindrical shape with threads at both ends. The outer diameter of the thread at the lower end is smaller and is used to connect with the central threaded hole inside the cylindrical platform of the lower mold 7. The outer diameter of the thread at the upper end is larger and the thread size is the same as that of the nut 1.

[0028] 1.4 The positioning pin 5 is cylindrical at one end, with an outer diameter that matches the circular hole on the deflector 3. The other end has a larger outer diameter and its surface can be knurled.

[0029] 1.5. The open washer 2 is a circular piece with a certain thickness and a diameter greater than the diameter of the cylindrical end face of the guide shroud 3. There is a long groove in the circular piece with a width greater than the diameter of the stud 4. One end of the long groove is a semicircle concentric with the circular piece, and the other end extends to the outside of the circular piece.

[0030] 1.6 Nut 1 is an external hexagonal part with a thread diameter matching that of stud 4. The maximum external hexagonal dimension is smaller than the inner diameter of the cylinder of the fairing 3. A standard part can be selected.

[0031] 2. Install the above-mentioned punching die onto the lower platform of the punch press. Use a pressure plate to fix the upper die 6 onto the upper platform of the press. In the same way, fix the lower die 7 onto the lower platform. Check and adjust the gap between the upper die cutting edge of the upper die 6 and the lower die cutting edge of the lower die 7 to ensure uniformity.

[0032] 3. Remove the positioning pin 5 and the open washer 2. Install the guide cover with evenly distributed round holes onto the positioning surface of the lower mold 7. Rotate the guide cover 3 and align the round holes with the positioning holes of the lower mold 7. Insert the positioning pin 5.

[0033] 4. Align the opening groove of the open washer 2 with the stud 4, press the end face against the cylindrical end face of the guide shroud 3, and screw the nut 1 into the stud 4 until the guide shroud 3 is pressed tightly against the positioning surface of the lower mold 7.

[0034] 5. Turn on the equipment. The upper mold 6 moves downward under the action of the upper platform. The cutting edge of the upper mold 6 cuts off the material on the wall of the guide shroud until it enters the groove of the lower mold 7. The cut waste is discharged downward along the opening of the lower mold 7.

[0035] 6. As the upper mold 6 moves up the platform, use a wrench to turn the loose nut 1 in the opposite direction, remove the open washer 2, and pull out the positioning pin 5.

[0036] 7. Move the guide shield 3 outward a certain distance and rotate it counterclockwise. When the left circular hole of the guide shield 3 is in the position of the positioning hole of the lower mold 7, insert the positioning pin 5.

[0037] 8. Repeat steps 4, 5, 6 and 7 to complete the punching of all slots, remove the guide shield 3, and complete the processing of the crescent groove.

[0038] Contents not described in detail in this specification are prior art known to those skilled in the art. Although illustrative specific embodiments of the invention have been described above to facilitate understanding by those skilled in the art, it should be understood that the invention is not limited to the scope of the specific embodiments. Various modifications are readily apparent to those skilled in the art as long as they fall within the spirit and scope of the invention as defined and determined by the appended claims, and all inventions utilizing the concept of this invention are protected.

Claims

1. A processing device for the crescent groove of a thin-walled conical spherical flow guide, characterized in that, include: The lower mold (7) consists of a base and a positioning surface. The base is a truncated pyramid, which includes a first side, a second side, a third side perpendicular to the bottom surface, and a fourth side at an acute angle to the bottom surface. The positioning surface is located on the fourth side surface and includes a cylindrical surface, a spherical surface, and a conical surface tangent to the spherical surface and whose centerline is concentric with the cylindrical surface, connected in sequence. The conical surface is connected to the fourth side surface, and there is an annular groove between the conical surface and the fourth side surface. A threaded hole is opened on the axial end face of the cylindrical surface away from the fourth side surface, and the generatrix length of the cylindrical surface is less than 1 / 3 of the length of the cylinder surface. The length of the cylinder of the guide shield (3) is greater than the length of the generatrix of the conical surface. The shape and size of the cylindrical surface, spherical surface and conical surface are consistent with the inner surface of the guide shield (3). A lower die cutting edge that meets the shape and size requirements of the crescent groove of the guide shield (3) is provided along the direction perpendicular to the bottom surface of the quadrangular frustum and directly above the spherical surface and the conical surface. The height of the lower die cutting edge extends downward along the surface. Below the lower die cutting edge is a material leakage hole that can contain the lower die cutting edge. Below the spherical surface is a cylindrical hole for inserting a pin that corresponds to the lower die cutting edge. The upper mold (6) includes an upper mold cutting edge whose shape and size correspond to the crescent groove of the fairing (3); Stud (4), the first axial end surface and the second axial end surface of the stud (4) are both threaded externally, wherein the second axial end of the stud (4) is connected to the threaded hole on the axial end surface of the cylindrical surface of the lower die (7); Nut (1), the nut (1) is connected to the first axial end of the stud (4); An open washer (2) includes an open long groove that extends through the thickness of the open washer (2). The open washer (2) is located between the axial end face of the nut (1) and the guide shield (3). The width of the open long groove is greater than the outer diameter of the stud (4). The positioning pin (5) is inserted into the cylindrical hole below the spherical surface of the lower mold (7). At least one section of the positioning pin (5) has an outer diameter equal to the diameter of the circular hole on the guide shield (3).

2. The device for processing crescent grooves of a thin-walled conical spherical guide shield according to claim 1, characterized in that: The lower end of the base of the lower mold (7) is connected to a cube, and the side length of the cube is greater than the maximum bottom side length of the base of the corresponding quadrangular frustum.

3. The device for processing crescent grooves of a thin-walled conical spherical flow guide according to claim 1, characterized in that: The upper mold (6) also includes a cube block, which is located above the upper mold cutting edge, and the cube block and the upper mold cutting edge are connected by a cuboid that encompasses the crescent-shaped cutting edge.

4. A method for machining the crescent groove of a thin-walled conical spherical air guide, characterized in that, Using the processing device described in claim 1, a crescent groove is processed on the guide shroud (3) by punching. Each time a crescent groove is punched, the axis of the guide shroud (3) is made at an angle with the vertical direction during punching. This angle ensures that the punching direction is consistent with the projection direction of the crescent groove on the guide shroud (3). The circumferential position is ensured by positioning with a circular hole. The middle part of the crescent groove on the guide shroud (3) is used as the punching center of the mold, and the normal direction of the generatrix of the conical surface at this point is the punching direction of the mold. The processing method includes the following steps: Step 1: Use a pressure plate to fix the upper die (6) to the upper platform of the punch press, and use a pressure plate to fix the lower die (7) to the lower platform of the punch press. Check and adjust the upper die (6) and the lower die (7) to make the gap between the cutting edge of the upper die and the periphery of the cutting edge of the lower die uniform. Step 2: Install the flow guide (3) with evenly distributed round holes onto the positioning surface of the lower mold (7), rotate the flow guide (3) and align any one of the round holes with the cylindrical hole below the spherical surface of the lower mold (7), and insert the positioning pin (5). Step 3: Align the open long groove of the open washer (2) with the stud (4), press the end face of the open washer (2) against the cylindrical end face of the guide shield (3), and screw the nut (1) and the stud (4) together until the guide shield (3) is pressed tightly against the positioning surface of the lower mold (7). Step 4: Start the punch press. The upper die (6) moves downward under the action of the upper platform. The upper die cutting edge cuts off the wall material of the guide shield (3) until it enters the lower die cutting edge of the lower die (7). The cut waste material is discharged along the material leakage hole of the lower die (7). Step 5: The upper mold (6) moves up with the upper platform, loosen the nut (1), remove the open washer (2), and pull out the positioning pin (5). Step 6: Move the guide shield (3) a certain distance away from the positioning surface of the lower mold (7), then rotate the guide shield (3) counterclockwise. When the other round hole on the guide shield (3) is aligned with the cylindrical hole below the spherical surface of the lower mold (7), insert the positioning pin (5) again. Step 7: Repeat steps 3 through 6 to complete the punching of all crescent-shaped grooves.

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