Machining method for large fan outlet guide vane panel type aviation blade

Abstract

The machining method for the large fan outlet guide vane panel type aviation blade comprises the steps that S101, a forged piece blank is subjected to primary machining, specifically, the forged piece blank is subjected to milling treatment through a numerical control machine tool, and a datum hole is milled in a preset position; s102, forging blank roughing process treatment is carried out; s103, the side vertical faces of the semi-finished product blade are symmetrically clamped through a pair of frog pliers, primary machining of allowance removal is carried out on the to-be-machined part, and the primary machining comprises primary machining of a flat basin back and a square datum of the to-be-machined part; s104, the basin, the back and the peripheral contour of the to-be-machined part are subjected to finish milling; and S105, all the twigs are removed, and the processing efficiency of the blades is improved.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of blade processing, and particularly relates to a processing method for large fan outlet guide vane panel type aviation blades. BACKGROUND

[0002] With the continuous increase of the bypass ratio of civil turbofan engines, the outer diameter of the bypass is also increasing, and the size of the fan outlet guide vane is also increasing. The number of blades is relatively large, generally several tens, and the weight of the blades is relatively heavy, which leads to a sharp increase in the weight of the outer bypass. If the weight of the fan outlet guide vane can be reduced, it will have a significant significance for the weight reduction of the entire engine. Currently, the world leading aircraft engine manufacturers all manufacture blades into hollow blades of multiple shapes. The hollow fan outlet guide vane assembly is divided into two parts: the fan outlet guide vane body + the fan outlet guide vane panel. The fan outlet guide vane panel is a large thin-walled aluminum alloy blade, and the wall thickness of the panel is 4mm. The panel is a thin-walled structure with an irregular curved surface, and the curvature changes greatly, and the machining rigidity is poor. At the same time, the panel itself has no fixture clamping reference and detection reference. The structure of the panel determines that it is the most easily deformed part in the entire product. If the panel does not match well with the body, it will directly lead to the size of the final assembly part blade to be out of tolerance. Moreover, the detection of the panel is also a big problem, and the process scheme requires extremely high. Therefore, how to give a reasonable processing scheme is the key to processing qualified panels.

[0003] The traditional method is to use the plate rib forming process for processing, and the deformation stress cannot be eliminated. Based on the influence of the machining stress deformation, the final blade size is more than 1mm out of tolerance. Since the profile tolerance requirement of the blade itself is within 0.1mm, the processing efficiency is low.

[0004] Therefore, the present application is proposed. SUMMARY

[0005] The purpose of the present application is to provide a processing method for large fan outlet guide vane panel type aviation blades, which solves the technical problem of low processing efficiency of the existing method, and effectively overcomes the difficult processing problem of large fan outlet guide vane panel type aviation blades, thereby improving the blade processing qualification rate. The technical scheme of the present application has many technical advantages, which will be introduced as follows: A processing method for large fan outlet guide vane panel type aviation blades is suitable for processing of fan outlet guide vane of a turbofan engine, and the processing method comprises, S101: initial processing of a forging blank, wherein the forging blank is subjected to milling flat treatment by a numerical control machine tool, and a reference hole is milled at a preset position; S102: roughing process treatment of the forging blank, wherein the target size of the designed blade is determined and the to-be-processed part with a margin is left, the forging blank is installed and roughing process treatment is performed according to the size of the to-be-processed part, the outer periphery of the to-be-processed part is connected to the forging blank through a plurality of wickers, and the space between any two wickers is hollow, thereby forming a semi-finished blade S103: the side vertical surface of the semi-finished blade is clamped in a symmetrical manner by using a frog clamp, and the to-be-processed part is subjected to margin removal primary processing, including primary processing of the flat basin back and four square references of the to-be-processed part; S104: the basin, back and four peripheral contours of the to-be-processed part are precisely milled; S105: all the wickers are removed.

[0006] Compared with the prior art, the technical scheme provided by the present application has the following beneficial effects: The method can remove stress multiple times before finishing, avoid deformation stress interference with the milling cutter during finishing, and ensure that the profile of the formed blade is within 0.1 mm. BRIEF DESCRIPTION OF DRAWINGS

[0007] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or the prior art description. Obviously, the drawings in the following description only represent some of the embodiments of the present application, and those skilled in the art can obtain other drawings according to these drawings without any creative effort.

[0008] Fig. 1 The flowchart of the present application; Fig. 2 The schematic diagram of processing the wickers. DETAILED DESCRIPTION

[0009] The embodiments of the present application will be described below through specific and concrete examples, and those skilled in the art can easily understand other advantages and effects of the present application from the disclosure. Obviously, the described embodiments are only some of the embodiments of the present application, not all. The present application can also be implemented or applied by other different specific embodiments, and the details in the specification can be modified or changed based on different views and applications without departing from the spirit of the present application. It should be noted that the following embodiments and features in the embodiments can be combined with each other without conflict. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without any creative effort are within the scope of protection of the present application.

[0010] It should be noted that various aspects of embodiments within the scope of the appended claims are described below. It will be apparent that the aspects described herein can be embodied in a wide variety of forms, and any particular structure and / or function described herein is merely illustrative. Based on this invention, those skilled in the art will understand that one aspect described herein can be implemented independently of any other aspect, and two or more of these aspects can be combined in various ways. For example, any number of aspects set forth herein can be used to implement the device and / or practice the method. Additionally, this device and / or method can be implemented using structures and / or functionalities other than one or more of the aspects set forth herein.

[0011] It should also be noted that the illustrations provided in the following embodiments are only schematic representations of the basic concept of the present invention. The drawings only show the components related to the present invention and are not drawn according to the actual number, shape and size of the components in the actual implementation. In the actual implementation, the form, quantity and proportion of each component can be arbitrarily changed, and the layout of the components may also be more complex.

[0012] Furthermore, specific details are provided in the following description to facilitate a thorough understanding of the examples. However, those skilled in the art will understand that aspects can be practiced without these specific details. To enable those skilled in the art to better understand the invention, the invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. The terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, features defined as "first" and "second" may explicitly or implicitly include one or more of that feature. In the description of the invention, unless otherwise stated, "a plurality of" means two or more.

[0013] like Figs. 1-2 The processing method for large fan outlet guide vane panels, as shown, is applicable to the processing of turbofan engine fan outlet guide vanes. Generally, blades larger than 400mm are considered large. The processing method includes... S101: Preliminary machining of the forging blank, wherein the forging blank is milled flat using a CNC machine tool, and reference holes are milled at preset positions. Reference holes are also opened at the four corner positions for subsequent machining references. Specifically... The six sides of the forging blank are clamped with a general-purpose vise. The CNC machine tool uses a D40R0.8 round nose end mill, and the milling cooling method is coolant. The machining parameters are set to a rotational speed S=1200-1400r / min and a feed rate F=600-800mm / min. The reference hole is machined using a D10 reamer and a milling coolant. The machining parameters of the CNC machine tool are set to a rotational speed of S = 4500-5000 r / min and a feed rate of F = 50-100 mm / min.

[0014] S102: Roughing process for forging blanks, which involves determining the target dimensions of the blades required by the design and the area to be machined after leaving allowances. After the forging blank is assembled, roughing is performed according to the dimensions of the area to be machined. See [link / reference]. Fig. 2 The outer circumference of the part to be processed is connected to the forging blank via multiple brambles, with a hollow structure between any two brambles, forming a semi-finished blade. The purpose is to achieve the removal of a large amount of excess material. Simultaneously, using brambles to connect the part to be processed to the continuously forged blank effectively releases stress during the bramble formation process, ensuring that the profile of the target blade is within 0.1mm during subsequent finishing, avoiding interference from micro-deformation stress. Specifically… The roughing of the back of the workpiece is done with a D20R2 end mill, and the machining method of simultaneous milling of the side edge and bottom teeth is adopted. The cooling method is milling coolant. The machining parameters of the CNC machine tool are set to a speed S=2300-2500r / min and a feed rate F=800-1200mm / min. The area to be machined is equipped with a D10 end mill, cooled by milling coolant, and the machining parameters are set to a rotational speed of S = 4500-5000 r / min and a feed rate of F = 600~800 mm / min. When semi-finish milling the back of the panel basin of the part to be machined, an Ø10R5 alloy ball end mill is used, and the side edge and bottom teeth are milled simultaneously. The milling coolant is used for cooling. The machining parameters are set as follows: rotational speed S=4500-5000r / min and feed rate F=1000-1200mm / min.

[0015] S103: After step 2, the semi-finished blade will generally deform. Step 3 processes its four edges to ensure the accuracy of the part during subsequent finishing. A vise clamp is used to symmetrically clamp the side surfaces (width edges) of the semi-finished blade. Preliminary machining of the part to be machined involves removing excess material, including preliminary machining of the flat back and four square reference points. For example, a D40R0.8 round nose end mill is used on the CNC machine tool, with milling coolant, and machining parameters set to a rotational speed S = 1200-1400 r / min and a feed rate F = 600-800 mm / min. It should be noted that clamping the side surfaces of the forging blank with a vise clamp reduces the rebound force on the reference surface due to vertical pressure machining, ensuring the required contour accuracy.

[0016] S104: Finish milling the basin, back, and surrounding contours of the part to be machined, specifically... The milling of the basin and the back side are carried out using an Ø10R5 alloy ball end mill, and the side edge and bottom teeth are milled simultaneously. The milling coolant is used for cooling. The machining parameters are set as follows: rotational speed S=4500-5000r / min and feed rate F=1200-1500mm / min. The four side profiles of the part to be machined are milled using a Ø10 ball end mill with milling coolant. The machining parameters are set to a spindle speed S = 4500-5000 r / min and a feed rate F = 600-800 mm / min, and no individual blades are milled. Since the stress and vertical pressure have been eliminated, the finishing process is not affected by deformation stress and will not produce deformation, ensuring that the final profile of the target blade is within 0.1 mm.

[0017] S105: Remove all brambles. Preferably, all brambles are removed manually using a handheld cutter to avoid leaf loss and damage, thus obtaining the final leaves.

[0018] Workflow: 1) Fix the blade to the worktable of the three-axis CNC machine tool with a vise according to the positioning method in the process specification. Use a D40R0.8 round nose milling cutter to mill the six planes of the part to the required dimensions in the process specification. Use a D10 reamer to machine the reference hole to the required dimensions.

[0019] 2) Place the milled part blank onto a special fixture. Use a feeler gauge to check that the gap between the part and the fixture contact surface is no greater than 0.02mm. After the blade is clamped, align the fixture. The non-parallelism of the base surface perpendicular to the X and Y axes of the machine tool, as measured by a dial indicator, should be no greater than 0.02mm. The operator calls up the machining program according to the process engineering and CNC operation card. First, use a D20R2 end mill to roughen the back of the basin, then use a D10 end mill to roughen the large allowance around the panel, and finally use a Ø10R5 alloy ball end mill for semi-finish milling of the back of the panel basin.

[0020] 3) Then, remove the panel from the special fixture. Use a frog pliers to press the rough-cut back and side reference surfaces of the part with a D40R0.8 round nose end mill to ensure the accuracy of the reference surfaces for subsequent finishing. Next, mount the part with the reference surfaces flattened onto the special fixture. Use a feeler gauge to check that the gap between the part and the fixture contact surface is no greater than 0.02mm. After the blades are clamped, align the fixture, ensuring that the non-parallelism of the base surfaces perpendicular to the X and Y axes of the machine tool, as measured by a dial indicator, is no greater than 0.02mm. The operator calls the machining program according to the CNC operation card, first using a Ø10R5 alloy ball end mill to finish mill the back of the panel, then using a Ø10 ball end mill to finish mill the surrounding contours. Finally, use a handheld cutting machine to cut off the surrounding brambles, and then use clamping and trimming the cut parts to complete the part machining.

[0021] The product provided by this invention has been described in detail above. Specific examples have been used to illustrate the principles and implementation methods of this invention. The descriptions of the embodiments above are merely for the purpose of helping to understand the core ideas of this invention. It should be noted that those skilled in the art can make various improvements and modifications to the invention without departing from the principles of the invention, and these improvements and modifications also fall within the protection scope of the invention claims.

Claims

1. A method for machining large fan outlet guide vane panels for aerospace blades, applicable to the machining of turbofan engine fan outlet guide vanes, characterized in that, The processing method includes, S101: Preliminary machining of forging blanks, wherein the forging blanks are milled flat by CNC machine tools and reference holes are milled at preset positions; S102: Roughing process of forging blank, wherein the target size of the blade required by the design and the part to be processed after leaving the allowance are determined, the forging blank is roughed according to the size of the part to be processed after being installed, so that the outer circumference of the part to be processed is connected to the forging blank through multiple braces, and any two braces are hollowed out to form a semi-finished blade. S103: The side surfaces of the semi-finished blades are clamped symmetrically using frog pliers, and the part to be processed is subjected to preliminary processing to remove excess material, including preliminary processing of the flat back and four-sided reference of the part to be processed. S104: Finish milling the basin, back, and surrounding contours of the part to be machined; S105: Remove all the described brambles.

2. The processing method according to claim 1, characterized in that, The initial processing of the forging blank in S101 includes, The six sides of the forging blank are clamped with a general-purpose vise. The CNC machine tool uses a D40R0.8 round nose end mill, and the milling cooling method is coolant. The machining parameters are set to a rotational speed S=1200-1400r / min and a feed rate F=600-800mm / min. The reference hole is machined using a D10 reamer and a milling coolant. The machining parameters of the CNC machine tool are set to a rotational speed of S = 4500-5000 r / min and a feed rate of F = 50-100 mm / min.

3. The processing method according to claim 1, characterized in that, The processing of the part to be processed in S102 includes, The roughing of the back of the workpiece is done with a D20R2 end mill, and the machining method of simultaneous milling of the side edge and bottom teeth is adopted. The cooling method is milling coolant. The machining parameters of the CNC machine tool are set to a speed S=2300-2500r / min and a feed rate F=800-1200mm / min. The area to be machined is equipped with a D10 end mill, cooled by milling coolant, and the machining parameters are set to a rotational speed of S = 4500-5000 r / min and a feed rate of F = 600~800 mm / min. When semi-finish milling the back of the panel basin of the part to be machined, an Ø10R5 alloy ball end mill is used, and the side edge and bottom teeth are milled simultaneously. The milling coolant is used for cooling. The machining parameters are set as follows: rotational speed S=4500-5000r / min and feed rate F=1000-1200mm / min.

4. The processing method according to claim 1, characterized in that, The initial processing in S103, which involves removing excess material from the part to be processed, includes... The CNC machine tool uses a D40R0.8 round nose end mill, employs milling coolant for cooling, and sets the machining parameters to a rotational speed of S=1200-1400r / min and a feed rate of F=600-800mm / min.

5. The processing method according to claim 1, characterized in that, In S104, the CNC machine tool performs machining on the front, back, and flip sides of the part to be machined. The milling of the basin and the back side are carried out using an Ø10R5 alloy ball end mill, and the side edge and bottom teeth are milled simultaneously. The milling coolant is used for cooling. The machining parameters are set as follows: rotational speed S=4500-5000r / min and feed rate F=1200-1500mm / min. The contours of the four sides of the part to be machined are milled using a Ø10 ball end mill, with milling coolant as the cooling method. The machining parameters are set as follows: rotational speed S=4500-5000r / min, feed rate F=600-800mm / min, and no individual bramble is milled or cut.

6. The processing method according to claim 1, characterized in that, S105 includes removing all the aforementioned brambles, All brambles were removed manually using a handheld cutter to obtain the final leaves.

Images