Fixture for machining aircraft engine casing and machining equipment based on the fixture

Abstract

The present invention discloses a fixture for processing aircraft engine casings, including a clamping device for clamping a workpiece during processing. The clamping device is equipped with a supporting unit, a clamping unit and a positioning unit, which provide comprehensive and stable support and clamping for the workpiece. A recessed portion is provided on the top surface of the supporting unit to form a supporting surface, corresponding to the bottom of the workpiece; the clamping unit has a clamping block, which wraps the outer circumferential surface of the workpiece and exposes the part to be processed; the positioning unit contains a top cover plate, a positioning column and a positioning disk, which realize the covering and precise positioning of the top of the workpiece. The above structure integrates supporting, clamping and positioning, realizes stable clamping and precise positioning of the workpiece, and is matched with a modularly designed anti-vibration knife structure to effectively suppress processing vibration. At the same time, the present invention will also propose processing equipment based on the fixture to optimize processing efficiency and quality, and provide strong guarantee for aircraft engine casing processing.

Description

Technical Field

[0001] The invention relates to the technical field of aircraft engine casing processing, and in particular to a fixture for aircraft engine casing processing and processing equipment based on the fixture. Background Art

[0002] The machining accuracy and service performance of key parts of aircraft engines are constantly improving with the advancement of aviation industry technology. Modern aircraft engines widely use thin-walled structural materials, which have the characteristics of asymmetry, variable cross-section, deep cavity and complex structure. The titanium alloy and aluminum alloy materials mainly used have relatively small elastic modulus, resulting in low stiffness of thin-walled structures, which are prone to deformation during processing such as milling of blanks.

[0003] As the core component of an aircraft engine, the casing has an important impact on the service performance and life of the engine. Since the dimensional accuracy of the casting blank is low and the surface quality cannot meet the use requirements, the casing must be machined to obtain the surface profile and roughness that meet the aerodynamic performance requirements. In the research on the processing and clamping of integral aviation structural parts, the square cavity blank usually adopts the peripheral clamping method, while the cylindrical thin-walled casing mostly adopts the bottom edge surface clamping or internal cylinder support.

[0004] During the machining process, the design of the clamping scheme and the arrangement of the clamping position are crucial. Reasonable fixture design can reduce part deformation while fixing the parts, reduce the impact of cutting force on part shape, and thus improve machining accuracy. In order to meet the requirements of smooth transition of the casing wall and continuous change of geometric curvature, milling is usually required on a swing-head five-axis machining center. However, the depth-to-diameter ratio of thin-walled casings is large, and interference between the tool and casing is likely to occur during milling, and cutting chatter, that is, tool vibration, is likely to occur, especially on the protruding part of the outer circumferential surface of the casing, which is more obvious, seriously affecting the cutting efficiency.

[0005] Existing solutions are mainly divided into two types: bottom clamping only and composite clamping. When only the bottom is clamped, the support surface of the receiver is placed on the pad to provide vertical support. However, during the milling process, the concentrated deformation caused by the cutting force mainly occurs on the outer wall surface at and near the processing position. The maximum deformation can reach 0.2-0.3mm. The volume of the deformed part is large, accounting for 10%-15% of the thickness of the outer wall. Composite clamping combines the top cover plate with the bottom support. Although the maximum deformation is reduced to 0.12-0.18mm, the vibration phenomenon is still not completely solved, and the deformation is still large, which cannot effectively control the deformation effect of the cutting force on the outer wall.

[0006] In summary, the clamping method has a significant impact on the deformation of the workpiece during casing milling. Although the composite clamping in the prior art has made some improvements, it still has some shortcomings. Therefore, we propose a new fixture for machining aircraft engine casings to solve the above problems. Summary of the invention

[0007] In view of the problems existing in the above-mentioned prior art, the present invention provides a fixture for processing aircraft engine casings, which integrates support, clamping and positioning, realizes stable clamping and precise positioning of the workpiece, and is equipped with a modularly designed anti-vibration knife structure to effectively suppress processing vibration. At the same time, the present invention will also propose processing equipment based on the fixture to optimize processing efficiency and quality, thereby providing strong guarantee for aircraft engine casing processing.

[0008] In order to achieve the above purpose, the aircraft engine casing processing fixture used in the present invention includes a clamping device for clamping the workpiece during processing. The clamping device is equipped with a supporting unit, a clamping unit and a positioning unit, which provides comprehensive and stable support and clamping for the workpiece. The top surface of the supporting unit is provided with a recessed portion to form a supporting surface corresponding to the bottom of the workpiece. Specifically, the top surface of the supporting unit has a recessed portion, and the recessed portion is formed with a supporting surface and the supporting surface corresponds to at least a section of the bottom of the workpiece; the clamping unit has a clamping block, which wraps the outer circumferential surface of the workpiece and exposes the part to be processed. Specifically, the clamping surface formed by the clamping block on the clamping unit wraps at least a section of the outer circumferential surface of the workpiece and exposes the part to be processed; the positioning unit includes a top cover plate, a positioning column and a positioning disk to achieve covering and precise positioning of the top of the workpiece. Specifically, the top cover plate can be arranged at the top opening of the workpiece and cover the top opening of the workpiece. A positioning column is provided under the top cover plate, and the top cover plate is connected to the positioning column through a first positioning pin. The central axis of the positioning column coincides with the central axis of the workpiece. At least one positioning disk is installed on the outer circumferential surface of the positioning column, and the outer circumferential surface of the positioning disk forms a positioning surface and the positioning surface contacts the protrusion on the inner surface of the workpiece; a positioning hole is set in the center of the top surface of the supporting unit to receive the positioning column.

[0009] As a further optimization of the above-mentioned scheme, the present invention focuses on optimizing the anti-vibration knife function and positioning accuracy of the fixture. First, the clamping blocks in the clamping unit are designed to be spliced ​​with each other, which is not only convenient for flexible adjustment according to the shape of the workpiece, but also through the arrangement of the first anti-vibration knife assembly, it effectively reduces the vibration during the processing and improves the smoothness and accuracy of the processed surface. Specifically, the first anti-vibration knife assembly is arranged on the clamping block, and the position of the first anti-vibration knife assembly is adjusted to ensure that it fits with the protruding part on the workpiece.

[0010] Secondly, the positioning plate adopts a splicing design, which makes positioning more flexible and can adapt to workpieces of different specifications, while ensuring positioning accuracy. Specifically, the positioning plate includes a first positioning part and a second positioning part, the first positioning part is installed on the positioning column, and the second positioning part is installed on the first positioning part through a second positioning pin, and the two adjacent second positioning parts are spliced ​​together.

[0011] In addition, the threaded engagement design between the clamping block and the first anti-vibration knife assembly enables precise adjustment of the anti-vibration knife assembly, further improving the processing accuracy. The cooperation between the driving rail and the second anti-vibration knife assembly, as well as the design of the fixed slot and the lock, ensure the stability and reliability of the anti-vibration knife assembly during the processing, and provide strong support for high-quality processing. Specifically, the clamping block is formed with an internal threaded surface, and the first anti-vibration knife assembly is threadedly engaged with the internal threaded surface. The rotation of the first anti-vibration knife assembly drives the first anti-vibration knife assembly to perform axial translation along the clamping surface. The horizontal surface of the first anti-vibration knife assembly is provided with two relatively arranged limiting perforations. After the position of the first anti-vibration knife assembly is fixed, the driving rail passes through the limiting perforations and extends into the annular groove reserved in the supporting unit. The second anti-vibration knife assembly is clamped on the driving rail and the second anti-vibration knife assembly remains parallel to the first anti-vibration knife assembly. The driving rail is provided with a fixed slot in a straight line direction on the inner surface, and the second anti-vibration knife assembly is equipped with a lock that cooperates with the fixed slot. The lock fixes the second anti-vibration knife assembly in a predetermined position, and the number of the fixed slots is at least two.

[0012] As a further optimization of the above scheme, the present invention focuses on optimizing the supporting function of the protruding part of the outer surface of the clamp and the workpiece, and realizes precise guidance and stable support for the tool by setting guide grooves and guide rails in the first anti-vibration knife assembly and the second anti-vibration knife assembly, as well as the sliding fit and splicing fixation of the guide block, thereby ensuring the accuracy of the tool path and the processing stability during the processing. At the same time, the design of the installation groove in the guide block enables the support members to be arranged at equal intervals, corresponding to the position of the protruding part of the workpiece, further enhancing the support strength and stability of the clamp on the protruding part of the workpiece. In addition, the design of the guide grooves and plug-in grooves on the upper and lower sides of the guide block, as well as the elastic locking member fixing method of the support member, not only facilitate the rapid installation and disassembly of the support member, but also ensure the firmness and reliability of the support member during the processing, providing a strong guarantee for efficient and precise processing. Specifically:

[0013] The first anti-vibration knife assembly and the second anti-vibration knife assembly are both provided with arc-shaped guide grooves, the upper and lower inner walls of the guide grooves extend inwardly and constitute guide rails, the guide blocks are installed in the guide grooves and slidably cooperate with the guide rails, the two adjacent guide blocks are spliced ​​with each other and fixed by a third positioning pin, the inner circumferential surface of the guide block is provided with mounting grooves, the support members are arranged at equal intervals in the mounting grooves and correspond to the positions of the protruding parts of the workpiece, the upper and lower sides of the guide blocks are both provided with guide grooves that cooperate with the guide rails, the guide grooves are provided with plug-in grooves, the elastic locking member of the support member extends into the plug-in groove and fixes the support member through the plug-in groove.

[0014] As a further optimization of the above-mentioned scheme, the present invention also introduces the aircraft engine casing processing fixture described in the above-mentioned technical scheme into the existing processing equipment, and forms a processing equipment based on the fixture. For the processing equipment, preferably, the present invention selects a five-axis linkage turning and milling compound processing machine tool, that is, introduces the aircraft engine casing processing fixture described in the present invention into the five-axis linkage turning and milling compound processing machine tool to improve the actual production efficiency and production effect of the five-axis linkage turning and milling compound processing machine tool.

[0015] The aircraft engine casing processing fixture of the present invention and the processing equipment based on the fixture have the following beneficial effects:

[0016] The aircraft engine casing processing fixture of the present invention provides comprehensive and stable support and clamping for the workpiece through the coordinated action of the supporting unit, the clamping unit and the positioning unit. The concave design of the supporting unit ensures stable support for the bottom of the workpiece, the clamping block of the clamping unit tightly wraps the outer circumference of the workpiece and accurately exposes the part to be processed, and the positioning unit realizes accurate covering and positioning of the top of the workpiece, effectively avoiding shaking or deviation during the processing process, and significantly improving the processing accuracy and stability.

[0017] The fixture for machining aircraft engine casings of the present invention is optimized with emphasis on the function and positioning accuracy of the anti-vibration knife. The splicing design of the clamping block in the clamping unit and the arrangement of the first anti-vibration knife assembly effectively reduce machining vibrations and improve the finish and accuracy of the machined surface. The splicing design of the positioning plate makes positioning more flexible and precise, and is suitable for workpieces of different specifications. At the same time, the threaded engagement design of the clamping block and the first anti-vibration knife assembly and the coordination of the drive rail and the second anti-vibration knife assembly ensure the stability and reliability of the anti-vibration knife assembly during machining, providing a strong guarantee for high-quality machining.

[0018] The fixture for processing the aircraft engine casing of the present invention realizes precise guidance and stable support of the tool by providing guide grooves and guide rails in the first anti-vibration knife assembly and the second anti-vibration knife assembly, as well as the sliding fit and splicing fixation of the guide blocks. The design of the mounting grooves in the guide blocks enables the support members to be arranged at equal intervals, corresponding to the positions of the protruding parts of the workpiece, thereby enhancing the support strength and stability of the fixture on the workpiece. In addition, the design of the guide grooves and plug-in grooves on the upper and lower sides of the guide blocks and the elastic locking member fixing method of the support members facilitate the rapid installation and disassembly of the support members, ensuring the firmness and reliability of the support members during the processing, thereby improving the processing efficiency.

[0019] With reference to the following description and drawings, a specific embodiment of the present invention is disclosed in detail, indicating the manner in which the principle of the present invention can be adopted. It should be understood that the scope of the embodiment of the present invention is not limited thereby, and the embodiment of the present invention includes many changes, modifications and equivalents. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 This is a schematic diagram of the structure of a fixture for machining an aircraft engine casing;

[0021] Figure 2 It is a structural schematic diagram of the supporting unit in the present invention;

[0022] Figure 3 It is a structural schematic diagram of the clamping unit in the present invention;

[0023] Figure 4 It is a structural schematic diagram of the clamping block in the present invention;

[0024] Figure 5 It is a structural schematic diagram of the positioning unit in the present invention;

[0025] Figure 6 It is a structural schematic diagram of the positioning plate in the present invention;

[0026] Figure 7 It is a structural schematic diagram of the second anti-vibration knife assembly in the present invention;

[0027] Figure 8 It is a structural schematic diagram of the first anti-vibration knife assembly in the present invention;

[0028] Fig. 9 It is a structural schematic diagram of the guide groove in the present invention;

[0029] Fig.10 This is a schematic diagram of the milling processing effect in the present invention (there is a color change but no obvious tool mark in the figure).

[0030] In the figure: 1. supporting unit; 11. recessed portion; 12. positioning hole; 13. annular groove; 2. clamping unit; 21. clamping block; 211. internal threaded surface; 3. positioning unit; 31. top cover plate; 32. positioning column; 33. positioning plate; 331. first positioning part; 332. second positioning part; 4. first anti-vibration knife assembly; 41. limiting perforation; 5. driving track; 51. fixing notch; 6. second anti-vibration knife assembly; 61. locking buckle; 7. guide groove; 71. guide slide rail; 8. guide block; 81. mounting groove; 82. supporting member; 821. elastic locking member; 83. guide slide groove; 831. plug-in groove. DETAILED DESCRIPTION

[0031] In order to make the purpose, technical solution and advantages of the present invention more clear, the present invention is further described in detail below through the accompanying drawings and embodiments. However, it should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the scope of the present invention.

[0032] It should be noted that when an element is referred to as being "disposed on, provided with" another element, it may be directly on the other element or there may also be a central element. When an element is considered to be "connected, connected to" another element, it may be directly connected to the other element or there may be a central element at the same time. "Fixed connection" means a fixed connection. There are many ways of fixed connection, which are not within the scope of protection of this article. The terms "vertical", "horizontal", "left", "right" and similar expressions used in this article are for illustrative purposes only and do not represent the only implementation method.

[0033] Unless otherwise defined, all technical and scientific terms used herein have the same meanings as those commonly understood by those skilled in the art to which the present invention belongs. The terms used in the specification are only for the purpose of describing specific embodiments and are not intended to limit the present invention. The term "and / or" used herein includes any and all combinations of one or more related listed items.

[0034] Please refer to the instruction manual Figure 1-8 The present invention provides a first embodiment of a fixture for machining an aircraft engine casing. The fixture design of this embodiment is based on the three major elements of the fixture, positioning, supporting and clamping, and designs a clamping device consisting of a supporting unit 1, a clamping unit 2 and a positioning unit 3, which provides comprehensive and stable support and clamping for a workpiece R (in the following embodiments, the workpiece is represented by R). The specific structure is as follows:

[0035] A recessed portion 11 is provided on the top surface of the supporting unit 1 to form a supporting surface corresponding to the bottom of the workpiece R. Preferably, in the present embodiment, the supporting unit 1 selects a pad structure fixedly arranged on the machine tool, so as to realize the support of the above-mentioned workpiece R in the vertical direction. Specifically, the top surface of the supporting unit 1 has a recessed portion 11, and the recessed portion 11 forms a supporting surface and the supporting surface corresponds to at least a section of the bottom of the workpiece R. At the same time, the supporting unit 1 in the present embodiment also has the functions of auxiliary clamping of the workpiece R, and positioning the positioning column 32 and the clamping unit 2. Specifically, in the present embodiment, a positioning hole 12 is set in the center of the top surface of the supporting unit 1 to receive the positioning column 32.

[0036] In some preferred embodiments, there are two connection mechanisms for fixing the supporting unit 1 and the clamping unit 2. One is a pin-type connection, in which a precise pin hole is preset on the supporting component to form a pin fit with the clamping component, and the connection between the two is achieved by inserting a fixing pin. The other is a pressure block connection, in which a pressure block that matches the outer side of the clamping component is used, and the pressure block is tightly fixed to the supporting component by fixing bolts and other fastening means, thereby ensuring the overall stability of the clamp structure.

[0037] The positioning unit 3, in this embodiment, includes a top cover plate 31, a positioning column 32 and a positioning disk 33, so as to achieve covering and precise positioning of the top of the workpiece R. Specifically, the top cover plate 31 can be arranged at the top opening of the workpiece R and cover the top opening of the workpiece R. A positioning column 32 is provided below the top cover plate 31. The top cover plate 31 is connected to the positioning column 32 through a first positioning pin. The central axis of the positioning column 32 coincides with the central axis of the workpiece R. At least one positioning disk 33 is installed on the outer circumferential surface of the positioning column 32. The outer circumferential surface of the positioning disk 33 forms a positioning surface and the positioning surface contacts the protrusion on the inner surface of the workpiece R. A positioning hole 12 is set at the center of the top surface of the supporting unit 1 to receive the positioning column 32. In the above structure, the positioning unit 3 and the supporting unit 1 work together to limit the horizontal rotation and vertical displacement of the workpiece R.

[0038] As a further description of the above scheme, in this embodiment, the top cover plate 31 adopts a hollow structure, specifically, including a central part located at the center of the top cover plate 31, a support plate part connected to the central part, and an outer ring part connected to the support plate part, together forming a hollow top cover plate 31 structure, thereby reducing the weight of the entire clamp.

[0039] Preferably, with respect to the positioning plate 33 in the above structure, the positioning plate 33 in this embodiment adopts a splicing design, so that the positioning is more flexible, and can adapt to workpieces R of different specifications, while ensuring the positioning accuracy. Specifically, the positioning plate 33 includes a first positioning portion 331 and a second positioning portion 332, the first positioning portion 331 is installed on the positioning column 32, and the second positioning portion 332 is installed on the first positioning portion 331 through a second positioning pin. Of course, in this embodiment, bolts and other structures can also be used for fixing. Preferably, in this embodiment, Figure 5 as well as Figure 6 In the embodiment, the first positioning portion 331 and the second positioning portion 332 are fixed by bolts, and two adjacent second positioning portions 332 are spliced ​​together.

[0040] Preferably, in the present embodiment, the first positioning portion 331 adopts a circular ring structure design, and the first positioning portion 331 is arranged with at least two circles of positioning grooves along the circumferential direction. In some examples, the number of positioning grooves is two circles, so that in the actual working process, the positioning grooves of the appropriate circle layer can be flexibly selected according to specific needs, and then the stable connection between the first positioning portion 331 and the second positioning portion 332 is ensured through a matching fixing method.

[0041] At the same time, the second positioning part 332 is preferably an arc-shaped structure, and the specific implementation form is an arc plate, which can form a complete annular structure through splicing. In order to further enhance the accuracy and stability of positioning, an auxiliary groove that matches the positioning groove on the first positioning part 331 is specially provided on the arc plate. In actual operation, by accurately passing the second positioning pin through the positioning groove and the auxiliary groove, the first positioning part 331 and the second positioning part 332 can be firmly fixed, thereby ensuring the high accuracy and reliability of the entire clamp system.

[0042] Taking into account the possible slight changes in the raised position of the inner wall of the flow channel of the cavity R of the workpiece during milling, in order to ensure the precision of the milling operation and effectively suppress the vibration of the tool, this embodiment proposes the following solution: by flexibly adjusting the connection position of the second positioning part 332 and the first positioning part 331, that is, selecting positioning grooves of different layers for fixing, the diameter between the outer circumferential surface of the second positioning part 332 and the central axis of the positioning column 32 is precisely adjusted. Ensure that the second positioning part 332 can fit closely to the raised part of the inner wall of the flow channel R of the workpiece, thereby significantly improving the actual application efficiency of the fixture and ensuring the accuracy and stability of the milling operation.

[0043] The clamping unit 2, in this embodiment, is a relatively large improvement on the basis of the existing composite clamp. In this embodiment, the clamping unit 2 has a clamping block 21, which wraps the outer circumferential surface of the workpiece R and exposes the part to be processed. Specifically, the clamping surface formed by the clamping block 21 on the clamping unit 2 wraps at least a section of the outer circumferential surface of the workpiece R and exposes the part to be processed of the workpiece R.

[0044] Based on the above discussion, the above fixture is applied to a five-axis linkage turning and milling machine tool. The tool is CNMG120404MS coated cemented carbide and a positive rake angle blade. The fixture of the present invention is used to clamp the workpiece R, and it is used with a 3mm cushion block. A 0.5mm large end face is reserved for turning as a fine turning reference. The large end face is required to be 100% visible to light and the flatness is less than or equal to 0.12mm. After turning, the deformation of the parts is checked. The maximum deformation of the fixture of the present invention at the processing position and the outer wall surface near it is only between 0.05-0.06mm. At the same time, there is almost no visible processing trace on the surface of the casing after processing, such as Fig.10 As shown, there is a color change at the cutting joint but no obvious cutting marks, and the surface roughness is better than Ra1.6μm, which meets the processing requirements of the receiver.

[0045] After an in-depth analysis of the background technology, it can be concluded that the clamping method has a significant impact on the deformation of parts. In the prior art, the bottom clamping and compound clamping methods are widely used. However, this mechanism can only effectively limit the two degrees of freedom of the receiver in the up and down directions and the rotational direction, which has obvious limitations. In contrast, the positioning fixture design proposed in the present invention realizes the precise positioning, support and clamping of all six degrees of freedom of the receiver, greatly improving the stability during the processing and effectively reducing the risk of deformation caused by processing. In particular, the positioning column 32 forms an internal support through the internal positioning plate 33, and cooperates with the external support formed by the external clamping unit 2 to act on the receiver together, significantly reducing the uneven force phenomenon of the receiver in the circumferential direction during the processing, thereby effectively controlling the deformation amount and achieving a high-precision, low-deformation clamping effect.

[0046] Please refer to the instruction manual Figure 1-8 The present invention provides a second embodiment of a fixture for machining an aircraft engine casing. This embodiment further designs the fixture in detail in view of the machining characteristics of the aircraft engine casing. In this embodiment, the clamping unit 2 of the fixture adopts a split design, which is convenient for flexible adjustment according to the size and shape of the workpiece R, ensuring comprehensive support for the outer circumferential surface of the workpiece R.

[0047] Specifically, the clamping block 21 of the clamping unit 2 in this embodiment adopts a modular design, and is spliced ​​and adjusted according to the shape of the outer circumferential surface of the workpiece R while maintaining sufficient clamping force. In this embodiment, the clamping block 21 adopts a roughly fan-shaped structure, and multiple fan-shaped clamping blocks 21 are spliced ​​to form a roughly annular clamping structure, and the inner surface of the clamping structure forms a clamping surface that wraps the outer circumferential surface of the workpiece R.

[0048] When analyzing the actual processing conditions, the outer circumferential surface of the workpiece R is designed with at least one row of protrusions, which are distributed in a circular array to form an air flow channel. This type of protrusion design is prone to cause problems in actual processing: because it is higher than the surface, if the fixture does not clamp this specific area specifically, tool vibration is likely to occur during processing, affecting the processing quality.

[0049] In view of this, the present embodiment integrates the first anti-vibration knife assembly 4 in the clamping unit 2, aiming to significantly reduce the machining vibration and improve the finish and precision of the machined surface. Specifically, the first anti-vibration knife assembly 4 is arranged on the clamping block 21, and its layout corresponds to the annular array protrusions on the outer circumferential surface of the workpiece R. By adjusting the position of the first anti-vibration knife assembly 4, it is ensured that it fits closely with the protrusions on the workpiece R, achieving effective support and fixation, thereby eliminating the risk of knife vibration caused by insufficient restraint of the protrusions.

[0050] In this embodiment, two designs are made for the relative position and connection mode of the clamping block 21 and the first anti-vibration knife assembly 4. Specifically, the clamping block 21 is firmly mounted on the bottom support structure by fasteners such as fixing pins. In terms of design, the clamping block 21 is flexible, and can directly contact the outer circumferential surface of the workpiece R to provide support, or maintain a certain gap and only serve as a carrier of the first anti-vibration knife assembly 4. This embodiment prefers the latter, that is, the configuration in which the clamping block 21 does not directly contact the workpiece R, so as to independently achieve precise clamping of the outer circumferential surface of the workpiece R and its protruding portion through the first anti-vibration knife assembly 4.

[0051] In order to achieve stable installation of the clamping block 21, connection elements such as locating pins are used to ensure the firm and precise positioning between the clamping block 21 and the support structure. Subsequently, the first anti-vibration blade assembly 4 is installed on the top surface of the clamping block 21. For ease of installation and maintenance, a quick connection mechanism such as locating pins is also used between the first anti-vibration blade assembly 4 and the clamping block 21 to achieve reliable separation and fixation of the two, greatly improving the convenience and efficiency of assembly.

[0052] In summary, this embodiment designs the fixture in detail according to the processing characteristics of the aircraft engine casing. The fixture clamping unit 2 adopts a split and modular structure, which can be flexibly adjusted according to the size and shape of the workpiece R to ensure full support. In particular, the first anti-vibration knife assembly 4 is integrated with the protruding part of the outer circumferential surface of the workpiece R, which effectively avoids the vibration of the knife during processing and significantly improves the processing quality.

[0053] Please refer to the instruction manual Figure 1-8 The present invention provides a third embodiment of a fixture for machining an aircraft engine casing. Through multiple tests, this embodiment understands that the structure of the positioning pin fixing clamp block 21 supporting the first anti-vibration knife assembly 4 has limitations, which is mainly reflected in the need to customize clamp block 21 molds of various heights according to different workpiece R specifications, which increases production complexity and cost. Taking the early exploration of this embodiment as an example, five sets of molds have been prepared, which significantly improves the overall manufacturing cost of the fixture.

[0054] In view of the above problems, this embodiment further optimizes the clamping block 21 of the clamp and the first anti-vibration knife assembly 4. The specific optimization measures are as follows:

[0055] In the third embodiment, the present invention adopts a threaded engagement design to connect the clamping block 21 and the first anti-vibration knife assembly 4, so as to achieve the fine-tuning action of the first anti-vibration knife assembly 4, so as to further improve the processing accuracy. In addition, through the coordinated setting of the driving track 5 and the second anti-vibration knife assembly 6, and the stable design of the fixing notch 51 and the lock buckle 61, the high stability and reliability of the anti-vibration knife assembly during the processing are ensured, laying a solid foundation for achieving high-quality processing.

[0056] Specifically, if Figure 7 As shown, the clamping block 21 and the first anti-vibration knife assembly 4 abandon the traditional upper and lower relationship, and the clamping block 21 is designed to be slightly higher than the first anti-vibration knife assembly 4. An internal threaded surface 211 is processed on the inner surface of the clamping block 21, and at the same time, it is ensured that the inner circumferential surface of the clamping block 21 maintains a certain gap with the workpiece R to avoid direct contact. The first anti-vibration knife assembly 4 is engaged with the internal threaded surface 211 of the clamping block 21 through the threads on its outer surface. When the first anti-vibration knife assembly 4 is rotated, the first anti-vibration knife assembly 4 will perform a translational movement along the axial direction of the clamping surface, thereby realizing precise adjustment of the position of the first anti-vibration knife assembly 4 in the vertical direction. Thereby simplifying the adjustment process and greatly improving the accuracy and efficiency of the adjustment.

[0057] Further analysis shows that, given that there are often two or more rows of protruding parts on the outer circumferential surface of the workpiece R, the present application adds a second anti-vibration knife assembly 6 above the first anti-vibration knife assembly 4 to fully cope with complex surface morphology. In the preferred design scheme, the first anti-vibration knife assembly 4 and the second anti-vibration knife assembly 6 adopt the same structural design, and are both equipped with a threaded structure that matches the internal threaded surface 211, ensuring that both can achieve precise displacement adjustment in the vertical direction through a simple rotation operation. This design not only improves the adaptability and flexibility of the fixture, but also significantly enhances the stable support and anti-vibration effect of the protruding parts of the workpiece R during processing, thereby ensuring the consistency and high precision of the processing quality.

[0058] However, in the actual application process, there is a specific problem: when only the position of the first anti-vibration knife assembly 4 needs to be adjusted, and the position of the second anti-vibration knife assembly 6 remains unchanged, the existing design requires that the second anti-vibration knife assembly 6 must be removed as a whole before the position adjustment in the vertical direction can be achieved by rotating the first anti-vibration knife assembly 4. In particular, the threaded structure, the operation process of screwing and removing is not only cumbersome, but also reduces the processing efficiency, and increases unnecessary labor costs and time consumption. Therefore, a more convenient and efficient adjustment scheme is urgently needed to achieve independent adjustment of the position of the first anti-vibration knife assembly 4 without affecting the stable operation of the second anti-vibration knife assembly 6.

[0059] In response to the above-mentioned problems, the present embodiment optimizes the structure of the first anti-vibration knife assembly 4. Specifically, the present application adds two relatively arranged limiting perforations 41 on the horizontal surface of the first anti-vibration knife assembly 4. When the position of the first anti-vibration knife assembly 4 is determined, the drive rail 5 will pass through the two limiting perforations 41 and continue to extend into the annular groove 13 pre-opened on the support unit 1. At this time, the second anti-vibration knife assembly 6 can be snapped onto the drive rail 5 and remain parallel to the first anti-vibration knife assembly 4. The original threaded fit is replaced by the snap-fit, making the removal of the second anti-vibration knife assembly 6 more convenient.

[0060] Therefore, the present application improves the structure of the first anti-vibration knife assembly 4, and the horizontal surface of the first anti-vibration knife assembly 4 is provided with two relatively arranged limit perforations 41. After the position of the first anti-vibration knife assembly 4 is fixed, the driving rail 5 passes through the limit perforation 41 and extends to the annular groove 13 reserved in the supporting unit 1. The second anti-vibration knife assembly 6 is clamped on the driving rail 5 and the second anti-vibration knife assembly 6 is kept parallel to the first anti-vibration knife assembly 4. The driving rail 5 is provided with a fixed slot 51 along a straight line direction on the inner surface, and the second anti-vibration knife assembly 6 is equipped with a lock 61 that matches the fixed slot 51. The lock 61 fixes the second anti-vibration knife assembly 6 in a predetermined position, and the number of the fixed slots 51 along the vertical direction is at least two.

[0061] Furthermore, the inner surface of the driving track 5 is provided with a fixed notch 51 along the straight direction, and the second anti-vibration blade assembly 6 is equipped with a lock 61 matching the fixed notch 51. Through the cooperation of the lock 61 and the fixed notch 51, the second anti-vibration blade assembly 6 can be fixed in a predetermined position. It is worth noting that the number of the fixed notches 51 arranged along the vertical direction is at least two, so that the second anti-vibration blade assembly 6 can select a suitable position for locking according to the actual situation.

[0062] Please refer to the instruction manual Figure 1-9 , the present invention discloses a fourth embodiment of a fixture for machining aircraft engine casings. In this embodiment, the present application has made more in-depth optimization and improvement on the anti-vibration knife assembly. Taking into account that the protruding portion of the outer circumferential surface of the workpiece R is actually a plurality of independent flow channels, and the extension distance of each flow channel may have slight deviations during the machining process, the clamping assembly of the above embodiment adopts a fixed-size annular anti-vibration knife assembly for clamping. Although the anti-vibration effect is improved compared to the existing composite fixture, there are still slight deficiencies. Especially for precision components such as aircraft engine casings, extremely high requirements are placed on the accuracy and adaptability of the anti-vibration knife assembly. Therefore, we propose the following specific improvement measures:

[0063] By setting the guide groove 7 and the guide rail 71 in the first anti-vibration knife assembly 4 and the second anti-vibration knife assembly 6, and the sliding fit and splicing fixation of the guide block 8, accurate guidance and stable support for the tool are achieved, ensuring the accuracy of the tool path and processing stability during the processing. At the same time, both anti-vibration knife assemblies are provided with an arc-shaped guide groove 7, and the upper and lower inner walls of the guide groove 7 extend inward to form a guide rail 71. The guide block 8 is placed in the guide groove 7 and realizes sliding fit with the guide rail 71. The adjacent guide blocks 8 are spliced ​​and fixed by the third positioning pin to ensure the overall stability.

[0064] The inner circumferential surface of the guide block 8 is provided with mounting grooves 81 for arranging support members 82 at equal intervals. The above-mentioned support members 82 correspond to the positions of the protruding parts of the workpiece R one by one, thereby significantly enhancing the supporting strength and stability of the fixture on the protruding parts of the workpiece R.

[0065] In addition, the upper and lower sides of the guide block 8 are provided with guide slots 83 matching the guide rails 71, and the slots are provided with plug-in slots 831. The support member 82 extends into the plug-in slot 831 through its built-in elastic locking member 821, so as to achieve fast and firm fixation. This facilitates the fast installation and removal of the support member 82, ensures the firmness and reliability of the support member 82 during the processing, and provides a solid guarantee for efficient and precise processing.

[0066] As a further optimization of the above-mentioned scheme, the present invention also introduces the aircraft engine casing processing fixture described in the above-mentioned technical scheme into the existing processing equipment, and forms a processing equipment based on the fixture. For the processing equipment, preferably, the present invention selects a five-axis linkage turning and milling compound processing machine tool, that is, introduces the aircraft engine casing processing fixture described in the present invention into the five-axis linkage turning and milling compound processing machine tool to improve the actual production efficiency and production effect of the five-axis linkage turning and milling compound processing machine tool.

[0067] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modification, equivalent substitution or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A fixture for machining an aircraft engine casing, characterized in that: The invention comprises a clamping device for clamping a workpiece during a machining process, wherein the clamping device is provided with a supporting unit (1), a clamping unit (2) and a positioning unit (3), wherein: The top surface of the supporting unit (1) has a recessed portion (11), the recessed portion (11) forms a supporting surface, and the supporting surface corresponds to at least a section of the bottom of the workpiece; The clamping unit (2) has a clamping block (21), and a clamping surface formed by the clamping block (21) on the clamping unit (2) wraps around at least a section of the outer circumferential surface of the workpiece and exposes a portion of the workpiece to be processed; The positioning unit (3) comprises a top cover plate (31), the top cover plate (31) can be arranged at the top opening of the workpiece and cover the top opening of the workpiece, a positioning column (32) is arranged below the top cover plate (31), the top cover plate (31) is connected to the positioning column (32) via a first positioning pin, the central axis of the positioning column (32) coincides with the central axis of the workpiece, at least one positioning disk (33) is mounted on the outer circumferential surface of the positioning column (32), the outer circumferential surface of the positioning disk (33) forms a positioning surface, and the positioning surface contacts a protrusion on the inner surface of the workpiece; The center of the top surface of the supporting unit (1) also has a positioning hole (12) for receiving a positioning column (32); Two adjacent clamping blocks (21) in the clamping unit (2) are spliced ​​and matched with each other to form a clamping structure, and a first anti-vibration knife assembly (4) is arranged on the clamping block (21), and the position of the first anti-vibration knife assembly (4) is adjusted to ensure that it fits with a protruding portion on the workpiece; The horizontal surface of the first anti-vibration blade assembly (4) is provided with two relatively arranged limiting through holes (41); after the position of the first anti-vibration blade assembly (4) is fixed, the driving rail (5) passes through the limiting through hole (41) and extends into the annular groove (13) reserved in the supporting unit (1); the second anti-vibration blade assembly (6) is clamped on the driving rail (5) and the second anti-vibration blade assembly (6) is kept parallel to the first anti-vibration blade assembly (4).

2. The fixture for machining an aircraft engine casing according to claim 1, characterized in that: The positioning plate (33) comprises a first positioning portion (331) and a second positioning portion (332), wherein the first positioning portion (331) is mounted on the positioning column (32), and the second positioning portion (332) is mounted on the first positioning portion (331) via a second positioning pin, and two adjacent second positioning portions (332) are spliced ​​together.

3. The fixture for machining an aircraft engine casing according to claim 2, characterized in that: An internal thread surface (211) is formed on the clamping block (21), and the first anti-vibration knife assembly (4) is threadedly engaged with the internal thread surface (211), and the rotation of the first anti-vibration knife assembly (4) drives the first anti-vibration knife assembly (4) to perform an axial translational movement along the clamping surface.

4. The fixture for machining an aircraft engine casing according to claim 3, characterized in that: The driving track (5) is provided with a fixing notch (51) on the inner surface along a straight line direction, and the second anti-vibration blade assembly (6) is equipped with a lock buckle (61) matched with the fixing notch (51), and the lock buckle (61) fixes the second anti-vibration blade assembly (6) at a predetermined position.

5. The fixture for machining an aircraft engine casing according to claim 4, characterized in that: The number of the fixing notches (51) is at least two.

6. The fixture for machining an aircraft engine casing according to claim 5, characterized in that: The first anti-vibration knife assembly (4) and the second anti-vibration knife assembly (6) are both provided with an arc-shaped guide groove (7), the upper and lower inner walls of the guide groove (7) extend inwardly and form a guide rail (71), the guide block (8) is installed in the guide groove (7) and slidably cooperates with the guide rail (71), two adjacent guide blocks (8) are spliced ​​with each other and fixed by a third positioning pin, the inner circumferential surface of the guide block (8) is provided with a mounting groove (81), and the support members (82) are arranged at equal intervals in the mounting groove (81) and correspond to the position of the protruding part of the workpiece.

7. The fixture for machining an aircraft engine casing according to claim 6, characterized in that: The guide block (8) is provided with guide grooves (83) matched with the guide rails (71) on both upper and lower sides, and a plug-in groove (831) is provided on the guide groove (83), and the elastic locking member (821) of the support member (82) extends into the plug-in groove (831) and fixes the support member (82) through the plug-in groove (831).

8. Processing equipment, characterized in that The processing equipment uses the aircraft engine casing processing fixture as described in any one of claims 1-7.

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