Blisk rough milling blade profile cutter and preparation method thereof

Abstract

The blisk blade profile rough milling cutter comprises a dish-shaped cutter head with an inner side molded surface and an outer side molded surface, the inner side molded surface is used for milling and washing a blade back of a blade, and the outer side molded surface is used for milling and washing a blade basin of the blade. The preparation method of the cutter comprises the following steps that the molded surface of the blade back of the blade is made to move horizontally, an initial inner side molded surface is obtained, and the molded surface of the blade basin of the blade is made to move horizontally; obtaining an initial outer side molded surface; the interference position of the initial inner side molded surface to the blade basin is found and corrected, and the interference position of the initial outer side molded surface to the blade back is found and corrected; and the dish-shaped cutter head with the corrected inner side molded surface and the corrected outer side molded surface is obtained. The molded surface of the cutter is obtained through direct fitting and correction according to the molded surface of the blade and the distortion degree, and the efficiency is high and the material removal rate is low.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of blade manufacturing processing, in particular to the field of rough milling blade profile cutters. BACKGROUND

[0002] The blisk is a new type of structural component designed to meet the requirements of high-performance aero-engines, which integrates the engine rotor blades and the wheel disc, eliminates the tenon, mortise and locking device in the traditional connection, reduces the structural weight and the number of parts, avoids the airflow loss of the tenon, and improves the aerodynamic efficiency.

[0003] However, the blisk channel is narrow and complex, the blade is twisted, the material removal rate of rough machining of the blade profile is large, and the machining cycle is long, which seriously affects the machining delivery cycle and the machining cost of the blisk.

[0004] Therefore, there is an urgent need for a rough milling blade profile cutter for directly machining the blisk to finely and efficiently machine the blisk. SUMMARY

[0005] An object of the present application is to provide a blisk rough milling blade profile cutter preparation method to obtain a rough milling blade profile cutter for efficiently machining the blisk.

[0006] The blisk rough milling blade profile cutter preparation method for achieving the above object comprises the following steps:

[0007] Translate the blade back profile to obtain an initial inner side profile, and translate the blade basin profile to obtain an initial outer side profile;

[0008] Find the interference position of the initial inner side profile to the blade basin and correct it, and find the interference position of the initial outer side profile to the blade back and correct it;

[0009] Obtain a disc cutter with a corrected inner side profile and a corrected outer side profile.

[0010] In one or more embodiments, the thickness of the disc cutter with the initial inner side profile and the initial outer side profile is adjusted so that the disc cutter can completely extend into the space defined by the adjacent blade.

[0011] In one or more embodiments, after the disc cutter completely extends into the space defined by the adjacent blade, the distance between the inner side profile and the blade back is greater than 0.5 mm, and the distance between the outer side profile and the blade basin is greater than 0.5 mm.

[0012] In one or more embodiments, the cutter further comprises an adapter root connected to the disc cutter, and an inner concave ring groove is formed on the adapter root to avoid the blade tip.

[0013] Another object of the present application is to provide a rough milling blade profile cutter for blisk, which comprises a disc-shaped cutter disc including an inner profile and an outer profile, the disc-shaped cutter disc extends into the space defined by adjacent blades, the inner profile is used to mill the blade back of the blade, and the outer profile is used to mill the blade basin of the blade.

[0014] In one or more embodiments, the cutter further comprises an adapter root provided with an inner concave ring groove for avoiding the blade tip.

[0015] In one or more embodiments, the inner profile and / or the outer profile comprises a local straight line segment.

[0016] In one or more embodiments, the cutter further comprises a blade circumferentially arranged on the disc-shaped cutter disc.

[0017] In one or more embodiments, the disc-shaped cutter disc gradually thickens from the cutter head to the cutter handle.

[0018] The rough milling blade profile cutter for blisk and the preparation method provide a blade profile cutter, the outer profile and the inner profile of the cutter disc are directly approximated and fitted according to the blade basin profile and the blade back profile of the part blade, and the interference problem of the cutter and the strength of the cutter are considered at the same time, which can effectively improve the rigidity and stability of the cutter, reduce cutter vibration, reduce cutter wear, improve cutting parameters, and then improve the machining efficiency, the cutting efficiency and the quality of the machined surface, and achieve the purpose of high-efficiency and low-cost manufacturing of high-quality blisk. BRIEF DESCRIPTION OF DRAWINGS

[0019] The above and other features, properties, and advantages of the present application will become more apparent by the following description with reference to the accompanying drawings and embodiments, in which:

[0020] Figure 1 is a partial sectional view of the rough milling blade profile cutter for blisk;

[0021] Figure 2 is a schematic view of the rough milling blade profile cutter for blisk machining the blade;

[0022] Figure 3 is a schematic view of the preparation of the inner profile and the outer profile;

[0023] Figure 4 is a flowchart of the preparation method of the rough milling blade profile cutter for blisk;

[0024] Figure 5 is a schematic view of the machining interference position.

[0025] SYMBOL EXPLANATION

[0026] 1 disc-shaped cutter disc

[0027] 2 blade

[0028] 3 blade

[0029] 4 wheel

[0030] 5 transition root

[0031] 6 flow passage

[0032] 11 inner profile

[0033] 12 outer profile

[0034] 31 blade back

[0035] 32 blade pot

[0036] 310 initial outer profile

[0037] 320 initial inner profile DETAILED DESCRIPTION

[0038] The present application is further described in the following Examples and Figures, and with the further particularity discussed in the following description. It should be understood that the application can be practiced with modification and alteration, and that the application be limited only by the scope of the appended claims. Thus, it should be understood that although the application has been described in detail with respect to specific embodiments and illustrative examples, the application is not to be limited to such but only seeks for protection furnished by the appended claims.

[0039] It is to be noted that these and other attached drawings have been included for illustrative purposes only and are not drawn to scale, and should not be used to construe the scope of the application as claimed.

[0040] Some embodiments use numerals to describe components, quantities of attributes. It should be understood that such numerals used in the description of embodiments, in some examples, are modified by the adjectives "about", "approximately", or "substantially". Unless otherwise stated, "about", "approximately" or "substantially" indicate that the number can vary by ±20%. Accordingly, numerical parameters such as those outlined in the application and claims are approximations, and can vary depending upon the desired properties sought to be obtained by the particular embodiments. In some embodiments, numerical parameters are approximations and can vary depending upon the desired properties sought to be obtained by the particular embodiments. In some embodiments, numerical parameters should be considered in the context of the number of significant digits used for those numerical parameters. Although the numerical ranges and parameters setting forth the broad scope of the application in some embodiments are approximations, the numerical values set forth in the specific examples are reported as precisely as practicable. The numerical values set forth in the specific examples are provided to be as precise as practicable.

[0041] An aero engine comprises major structures such as a fan, compressor, turbine, and combustion chamber. The fan draws in a large volume of air, while the compressor compresses the air drawn into the core, progressively increasing its pressure and temperature to achieve efficient combustion in the combustion chamber. The combustion chamber mixes the high-pressure air and fuel, igniting the fuel to produce high-temperature, high-pressure combustion gases. The turbine uses these gases to drive the fan and compressor, expelling the expanded airflow at high speed, generating thrust.

[0042] Blades are key components in aero engines and have a significant impact on engine performance. Blade design and hub structure are crucial for providing higher thrust efficiency.

[0043] Integral bladed disks (IBDs) are a new type of structural component designed to meet the requirements of high-performance aero engines. They integrate the engine rotor blades and the disk into a single structure, used to fix and support the blades and transmit power during rotation. IBDs are generally made of high-strength alloy materials, such as nickel-based alloys or titanium alloys, which have good thermal stability and mechanical properties.

[0044] The integral bladed disk eliminates the tenons, mortises, and locking devices found in traditional connections, reducing structural weight and the number of parts, avoiding airflow loss at the tenons, improving aerodynamic efficiency, and greatly simplifying the engine structure.

[0045] The hub and blades of integral bladed disks are typically manufactured using precision machining methods such as milling, which involve fine machining to meet design requirements. Milling removes material and shapes the workpiece to the desired form and size by moving a rotating cutting tool across it.

[0046] Disc cutter heads are one of the most commonly used cutting tools in milling. They consist of a disc-shaped cutter head and multiple inserts. The inserts are the parts with cutting edges used to cut the workpiece and remove material. The cutter head is the part that connects and fixes the inserts, which are connected to the cutter head by methods such as clamping, welding, or nailing. Disc cutter heads have the advantages of high cutting efficiency and strong interchangeability in milling, and can also be used to machine integral bladed disks.

[0047] Integral bladed disks are key components of aero engines. The rapid development of engines requires aero bladed disks to rotate at higher speeds, operate at higher temperatures and pressures, which in turn requires significant improvements in the geometry, material properties and manufacturing precision of the bladed disks.

[0048] As blades become increasingly distorted, longer, and narrower, only slender rod-shaped milling cutters can be used for milling. Especially when rough milling blades, the material removal is very large because the parts are solid and have grooves. However, due to the slenderness and insufficient rigidity of the cutter, the cutting force fluctuates greatly during the milling process. This leads to two problems: firstly, vibration is likely to occur on the blade surface, causing the cutter to wear quickly; secondly, in order to reduce vibration and extend tool life, cutting parameters are usually reduced, resulting in low rough milling efficiency, long processing time, and high manufacturing costs.

[0049] Based on this, the present invention proposes a method for preparing a rough milling tool for integral bladed disks, so as to prepare an integral bladed disk rough milling tool capable of fine and efficient machining of integral bladed disks.

[0050] Reference Figures 1 to 3 Understandably, the cutting tool includes a disc-shaped cutter head 1 and a cutting insert 2, with the cutting insert 2 clamped on the cutter head 1. The cutting insert 2 is a carbide round insert, circumferentially arranged on the disc-shaped cutter head 1, with a diameter of less than or equal to 13 mm, preferably 6-10 mm.

[0051] The disc-shaped cutter head 1 includes an inner profile 11 and an outer profile 12, which are used to mill the blade back 31 and blade base 32 of the blade 3, respectively. The blade 3 and the disc 4 are an integral structure.

[0052] like Figure 3 As shown, the method includes the following steps:

[0053] The blade back surface 31 is translated to obtain the initial inner surface 310, and the blade base surface is translated to obtain the initial outer surface 320.

[0054] Find and correct the interference position of the initial inner profile 310 with the blade tip 32, and find and correct the interference position of the initial outer profile 320 with the blade back 31. Figure 5 The machining interference N shown is caused by the excessively large arc of the surface, and there will also be machining interference positions caused by the tool being too wide.

[0055] To obtain a disc-shaped cutter head with modified inner and outer profiles, that is... Figure 1 The inner surface 11 and the outer surface 12 are shown. Figure 3 The area A shown, or Figure 5 If interference or strength problems occur at region N, then corrections are made to that region, for example, by using local straight lines or curves and making that region transition smoothly with the rest, thus correcting the initial surface.

[0056] Furthermore, the thickness of the disc-shaped cutterhead with the initial inner profile 310 and the initial outer profile 320 is adjusted so that the disc-shaped cutterhead can fully extend into the space defined by the adjacent blades, such as... Figure 1The flow channel 6 is shown. Due to the large blade twist, the flow channel 6 between the blades becomes narrower closer to the wheel 4, so it is necessary to ensure that the disc cutter head 1 can be fully inserted into the flow channel 6.

[0057] In some embodiments, after the disc-shaped blade is fully inserted into the space defined by the adjacent blade, the distance between the inner profile 11 and the back of the blade 31 is greater than 0.5 mm, and the distance between the outer profile 12 and the blade base 32 is greater than 0.5 mm.

[0058] The cutting tool also includes an adapter root 5 connected to the disc-shaped cutter head 2, which has an inner concave annular groove 13 on the adapter root 5 to avoid the blade tip 33, and can also reduce the size of the entire cutter head.

[0059] Based on the above description of the preparation method, a rough milling tool for integral bladed disks can also be understood. The disc-shaped cutter head 1 includes an inner profile 11 and an outer profile 12. The disc-shaped cutter head 1 extends into the space defined by the adjacent blades 3. The inner profile 11 is used to mill the blade back 31, and the outer profile 12 is used to mill the blade base 32.

[0060] The inner surface 11 of the disc-shaped cutter head 1 is approximately fitted according to the surface of the blade back 31 of the part. The inner surface of the disc-shaped cutter head 1 can be simplified into a curve according to the blade surface and the degree of twist, and can also be a straight line in some areas. However, the distance between the inner surface of the disc-shaped cutter head 1 and the surface of the blade back 31 should be greater than or equal to 0.5 mm, preferably 0.8-1 mm.

[0061] The outer surface 12 of the disc-shaped cutter head 1 is approximately fitted according to the surface of the blade 32 of the part. The outer surface of the disc-shaped cutter head 1 can be simplified into a curve according to the blade surface and the degree of twist, and can also be a straight line in some areas. However, the distance between the outer surface of the disc-shaped cutter head 1 and the surface of the blade 32 is greater than or equal to 0.5 mm, preferably 0.8-1 mm.

[0062] The adapter root 5 of the cutting tool is provided with an inner concave annular groove 13, which is designed according to the shape and size of the blade tip 33 of the part, and is used to avoid the blade tip. This design can also reduce the size of the cutting tool.

[0063] The following describes how to use the rough milling tool for this integral bladed disk.

[0064] Determine the allowance for rough milling of the integral bladed disk blade profile to be used for finish milling, and determine the rough milling area. The allowance for rough milling of the blade profile to be used for finish milling should be ≥0.5mm, preferably 0.8-1.5mm.

[0065] In general CAM programming software, based on the tool prepared by the above method and the determined rough milling area, a model is established, the machining path is compiled, and the corresponding CNC program is generated. When compiling the rough milling path for the blade shape in the CAM programming software, grooving should be performed layer by layer, preferably dynamic milling. The allowance removed from each layer should be greater than or equal to 0.5 mm, preferably 0.5-1 mm.

[0066] Select the appropriate cutting parameters based on the material of the part, the material of the milling cutter, and the depth of cut.

[0067] Select a suitable five-axis machining center for rough milling blades. The five-axis machining center should be a machine tool suitable for heavy cutting, with a spindle torque ≥60 N.m, preferably ≥80 N.m; and a maximum spindle power ≥20 kW, preferably ≥30 kW.

[0068] The above-mentioned disc-shaped cutter head has the following advantages:

[0069] (1) It can significantly improve the rigidity of the tool: the blade gradually thickens from the tool head to the tool holder. Compared with the blade of the traditional straight blade, the rigidity of the tool is significantly increased due to the increase in the cross-sectional area and thickness of the blade. The blade of the disc blade is designed in an arc shape, which has higher load-bearing capacity and significantly increases the resistance to disturbance during the tool processing, further improving the rigidity of the tool. For example, when it is adapted to heavy cutting machine tools, it can effectively improve the rigidity system during the cutting process.

[0070] (2) It can also reduce the vibration of the cutting tool during the cutting process. Based on the fact that the rigidity of the disc cutter head is significantly improved compared with the traditional straight cutter head, the disc cutter head performs layer-by-layer slot milling, preferably dynamic milling, and the allowance removed from each layer should be greater than or equal to 0.5mm, preferably 0.5-1mm. The cutting depth is small and dynamic milling is adopted, which greatly reduces the probability of the tool entering and cutting. Considering that the tool and the workpiece are most likely to generate vibration when they first enter the cutter, the cutting resistance is small and stable, which can effectively reduce the vibration of the cutting tool during the cutting process, thereby improving the cutting efficiency and the quality of the machined surface.

[0071] (3) It can reduce tool wear, reduce material removal rate, improve cutting parameters and thus improve processing efficiency, so as to achieve the purpose of efficient and low-cost manufacturing of integral bladed disks. It is especially suitable for batch processing of integral bladed disks. Compared with the traditional method of using bar milling cutters to groove shape, the processing efficiency can be increased by more than 30%-50%, tool consumption and tool cost are reduced by more than 60%, and the overall manufacturing cost is reduced by more than 50%. It can efficiently complete the processing of integral bladed disks.

[0072] In the description of this application, it should be understood that the orientation or positional relationship indicated by directional terms such as "front, back, up, down, left, right", "inner", "outer", "horizontal, vertical, horizontal" and "top, bottom" are generally based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description. Unless otherwise stated, these directional terms do not indicate or imply that the device or element referred to must have a specific orientation or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on the scope of protection of this application; the directional terms "inner" and "outer" refer to the inside and outside relative to the outline of each component itself.

[0073] For ease of description, spatial relative terms such as "above," "on top of," "on the upper surface of," "above," etc., are used herein to describe the spatial positional relationship of a device or feature as shown in the figures to other devices or features. It should be understood that spatial relative terms are intended to encompass different orientations in use or operation beyond the orientation of the device as described in the figures. For example, if the device in the figures were inverted, a device described as "above" or "on top of" other devices or structures would subsequently be positioned as "below" or "under" other devices or structures. Thus, the exemplary term "above" can include both "above" and "below." The device may also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatial relative descriptions used herein will be interpreted accordingly.

[0074] Furthermore, this application uses specific terms to describe embodiments of the application. For example, "an embodiment," "one embodiment," and / or "some embodiments" refer to a particular feature, structure, or characteristic related to at least one embodiment of the application. Therefore, it should be emphasized and noted that "an embodiment," "one embodiment," or "an alternative embodiment" mentioned twice or more in different locations in this specification do not necessarily refer to the same embodiment. In addition, certain features, structures, or characteristics in one or more embodiments of the application can be appropriately combined.

[0075] While the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the invention. Any variations and modifications can be made by those skilled in the art without departing from the spirit and scope of the invention. Therefore, any modifications, equivalent changes, and alterations made to the above embodiments based on the technical essence of the present invention, without departing from the scope of the invention, fall within the protection scope defined by the claims of the present invention.

Claims

1. A method for preparing a rough milling tool for an integral bladed disk, the tool comprising a disc-shaped cutter head, wherein the disc-shaped cutter head includes an inner profile and an outer profile, characterized in that, Includes the following steps: The blade back profile is translated to obtain the initial inner profile, and the blade base profile is translated to obtain the initial outer profile. Find and correct the interference position of the initial inner shape surface to the blade leaf basin; find and correct the interference position of the initial outer shape surface to the blade leaf back. A disc-shaped cutterhead with modified inner and outer profiles is obtained.

2. The method for preparing a rough milling blade for an integral bladed disk as described in claim 1, characterized in that, The thickness of the disc-shaped cutterhead with initial inner and outer profiles is adjusted so that the disc-shaped cutterhead can fully extend into the space defined by the adjacent blades.

3. The method for preparing a rough milling blade profile tool for an integral bladed disk as described in claim 1, characterized in that, After the disc-shaped blade extends completely into the space defined by the adjacent blades, the distance between the inner surface and the back of the blade is greater than 0.5 mm, and the distance between the outer surface and the leaf base is greater than 0.5 mm.

4. The method for preparing a rough milling blade for an integral bladed disk as described in claim 1, characterized in that, The cutting tool also includes an adapter root connected to the disc-shaped cutting disc, with an inner concave annular groove on the adapter root to avoid the blade tip.

5. A rough milling tool for integral bladed disks, characterized in that, Prepared using the method described in any one of claims 1-4, the tool includes a disc-shaped cutter head, including an inner profile and an outer profile, the disc-shaped cutter head extending into a space defined by adjacent blades, the inner profile being used for milling the back of the blade, and the outer profile being used for milling the base of the blade.

6. The integral bladed disk rough milling blade profile cutter as described in claim 5, characterized in that, The tool also includes an adapter root, which has an inner concave annular groove to avoid the blade tip.

7. The integral bladed disk rough milling blade profile cutter as described in claim 5, characterized in that, The inner surface and / or the outer surface include local straight line segments.

8. The integral bladed disk rough milling blade profile cutter as described in claim 5, characterized in that, The tool also includes blades circumferentially arranged on the disc-shaped cutter head.

9. The integral bladed disk rough milling blade profile cutter as described in claim 5, characterized in that, The disc-shaped cutter head gradually thickens from the cutter head to the handle.

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