Method of repairing a double-shouldered vane profile

Abstract

The application discloses a kind of efficient double-shaft neck vane profile repair methods, including using self-centering jaw to hold the flat mouth at upper shaft neck, to ensure that the center of double-shaft neck vane A axis angular direction and Z axis direction coincides with the center of rotation of machine tool;Using the tool bar radius less than the tool bar of boss exposure upper shaft neck distance to limit the position of upper shaft neck in X axis, Y axis direction;First, use rough milling to process the excess of double-shaft neck vane profile to uniform state, then through precision milling to ensure the size of double-shaft neck vane profile, while eliminating the deformation amount in rough milling.The application solves the problems of large deformation, low positioning efficiency and low pass rate of double-shaft neck vane profile repair parts at present.

Description

Technical Field

[0001] This invention belongs to the field of machining technology, specifically relating to an efficient machining method for reworking the profile of a double-judge blade. Background Technology

[0002] Aero-engine blades are technology-intensive, high-investment, and high-risk products that directly impact the safety and reliability of aero-engine operation. The compressor is one of the most critical components of an aero-engine, directly affecting its thrust-to-weight ratio, lifespan, reliability, safety, and maintainability. As a type of double-journal blade used in the compressor, its A-axis angular direction is not uniform due to blade deformation during rework. Therefore, the angular direction must be determined based on the even distribution of blade margin. However, the clamping range of the finished double-journal blade is small, and requirements such as preventing journal damage must be met, severely limiting the rework pass rate of double-journal blades. Summary of the Invention

[0003] This invention aims to provide a method for reworking the surface of a double-judge blade, solving the problems of large deformation, low positioning efficiency, and low pass rate in the current rework of double-judge blade surfaces.

[0004] To achieve the above objectives, the present invention adopts the following technical solution:

[0005] A method for reworking the profile of a double-journal blade, wherein the upper journal of the double-journal blade contains a flat opening and a boss, and the rework method includes...

[0006] Step 1: Use self-centering jaws to clamp the flat end at the upper journal to ensure that the center of the double journal blade in the A-axis angular direction and the Z-axis direction coincides with the rotation center of the machine tool;

[0007] Step 2: Use a tool holder with a radius smaller than the distance the boss protrudes from the upper journal to define the position of the upper journal in the X and Y axis directions;

[0008] Step 3: First, use rough milling to process the allowance of the double journal blade profile to a uniform state, and then use finish milling to ensure the dimensions of the double journal blade profile while eliminating the deformation in the rough milling.

[0009] Furthermore, in step one, the flat end at the upper journal is clamped using self-centering jaws, ensuring that the plane of the flat end is parallel to the horizontal plane.

[0010] Furthermore, in step two, the theoretical center position of the tool holder is used as the positioning reference point, and the tangent points of the maximum value points of the outer contour of the tool holder in the X-axis direction and the Y-axis direction with the outer surface of the boss and the outer surface of the upper journal are used as limiting points to define the position of the upper journal in the X-axis and Y-axis.

[0011] Compared with the prior art, the present invention, on the one hand, uses a self-centering jaw to clamp and align the A-axis angular direction and Z-axis direction, and corrects the journal to compensate for the error caused by the deformation of the part; on the other hand, it uses a tool holder to limit the position of the journal in the X-axis and Y-axis directions to achieve fast and accurate positioning and ensure the consistency of clamping; finally, rough milling is used to determine the allowance and finish milling is used to ensure the dimensions, so as to avoid scrap caused by rework. Attached Figure Description

[0012] Figure 1 This is a schematic diagram of the blade clamping and centering of the blade in the A-axis angular direction and Z-axis direction according to the present invention;

[0013] Figure 2 This is a schematic diagram showing the X-axis and Y-axis positions of the upper journal of the blade clamping tool holder in this invention;

[0014] Figure 3 for Figure 2 The right view;

[0015] Figure 4 for Figure 2 Top view;

[0016] In the diagram: 1-upper journal, 2-flat mouth, 3-boss. Detailed Implementation

[0017] The present invention will be further described below with reference to the accompanying drawings and specific embodiments. However, it should not be construed that the scope of the subject matter of the present invention is limited to the following embodiments. All modifications, substitutions and alterations made based on ordinary technical knowledge and common practices in the art without departing from the above-described technical concept of the present invention are included within the scope of the present invention.

[0018] This invention proposes a suitable processing method for the rework of double-judge blade profiles, mainly including the following aspects:

[0019] (1) Use self-centering jaws to clamp the flat end 2 (i.e., the upper journal 1) at the journal 1. Figure 3 The structure consists of two parallel planes on the left side of the upper journal 1 to ensure that the center of the double journal blade in the A-axis angular direction and the Z-axis direction coincides with the rotation center of the machine tool. This is because the center of the self-centering jaw is at the rotation center, and the two jaws move synchronously towards the center when the self-centering jaw clamps, so it can ensure that the center of the double journal blade in the Z-axis direction coincides with the rotation center of the machine tool.

[0020] (2) Use a tool holder with a radius smaller than the exposed distance of the boss 3 at the upper journal 1 to define the X-axis and Y-axis positions of the upper journal 1.

[0021] (3) Use rough milling to determine the allowance and finish milling to ensure the dimensions, thus ensuring the pass rate of the rework process.

[0022] like Figures 1-4 As shown, for the CNC milling of double-jersey blade profile rework, this embodiment uses a fixture and tool holder for rapid alignment and positioning, rough milling to determine the allowance, and finish milling to ensure dimensions, thus performing double-jersey blade profile rework efficiently and stably.

[0023] In this embodiment, the clamp used is a self-centering jaw, which can keep the blade's Z-axis at the machine tool's rotation center during the clamping of the flat jaw 2. The exposed distance of the boss 3 at the upper journal 1 (i.e., Figure 2 The distance D3, where D3 = (D2 - D1) / 2), is used with a D3R1.5 tool holder to limit the position of the upper journal 1 in the X and Y axes. This is sufficient to ensure that the tool holder contacts the boss 3 and the upper journal 1 at the maximum contour values ​​in the X and Y axes. Figure 4 In the middle, the maximum point of the outer contour of the tool holder in the Y-axis direction is tangent to the outer surface of the upper journal 1 at point A, and the maximum point of the outer contour of the tool holder in the X-axis direction is tangent to the outer surface of the boss 3 (flow channel surface) at point B.

[0024] Specifically, the rework method for dual-journey blades includes the following steps:

[0025] Step one: Due to the slender shape of the double-jersey blades, deformation occurs during machining and subsequent storage. To correct the impact of this deformation on the rework of the double-jersey blade profile, the flat end 2 at journal 1 is used as a positioning reference to clamp the double-jersey blades in conjunction with the lower journal. For example... Figure 1 As shown, the flat end 2 at the upper journal 1 is clamped by a self-centering jaw to ensure that the center of the double journal blade in the A-axis angular direction and the Z-axis direction coincides with the rotation center (A-axis) of the machine tool.

[0026] Step two: To ensure quick alignment of the X and Y axis origins, if a dial indicator is used for alignment, the X-axis direction is not fixed each time it is clamped, requiring re-entry each time, which is prone to errors and introduces errors with each dial indicator reading, increasing the difficulty of rework. For example... Figures 2-4 As shown, a tool holder with a radius smaller than the exposed distance D3 of the boss 3 at the upper journal 1 is used (only by meeting this condition can it be guaranteed that the maximum values ​​of the outer contour of the tool holder on the X and Y axes are tangent to the boss 3 and the upper journal 1). The theoretical position of the center of the tool holder is calculated. Each time, the tool holder is moved to a fixed position and the outer contour of the tool holder is made to contact the boss 3 (flow channel surface) and the upper journal 1 at the maximum values ​​in the X and Y axes. The machining origin is then aligned to ensure efficient machining of the double journal blade profile rework.

[0027] Step 3: Due to differences in the position of the reworked dual-journal blades, using a fixed procedure for the rework of the dual-journal blade profile would result in the scrapping of some parts. To ensure a high pass rate, a separate roughing and finishing milling method is adopted (because the double-journal blades have already been machined, there is an uneven distribution of allowance in the area to be repaired. Rough milling will make the allowance uniform, and finishing milling will ensure the machining dimensions of the profile while eliminating rough milling deformation). By determining the allowance through rough milling and ensuring the dimensions through finishing milling, the rework of the double-journal blade profile is guaranteed to be 100% qualified.

[0028] Contents not described in detail in this specification are prior art known to those skilled in the art. Although the present invention has been described above with reference to specific embodiments, it should be understood that the present invention is not limited to the scope of the specific embodiments. For those skilled in the art, any variations falling within the scope defined by the claims are protected by this invention.

Claims

1. A method for reworking the profile of a double-journal blade, wherein the upper journal (1) of the double-journal blade contains a flat opening (2) and a boss (3), characterized in that: Repair methods include, Step 1: Use self-centering jaws to clamp the flat end (2) at the upper journal (1) to ensure that the center of the double journal blade in the A-axis angular direction and the Z-axis direction coincides with the rotation center of the machine tool; Step 2: Use a tool bar with a radius smaller than the distance from the boss (3) to the upper journal (1) to define the position of the upper journal (1) in the X and Y axes; Step 3: First, use rough milling to machine the allowance of the double journal blade profile to a uniform state, and then use finish milling to ensure the dimensions of the double journal blade profile while eliminating the deformation in the rough milling. In step one, the flat opening (2) at the upper journal (1) is clamped using self-centering jaws, and the plane of the flat opening (2) is parallel to the horizontal plane. In step two, the theoretical center position of the tool holder is used as the positioning reference point. The maximum point of the outer contour of the tool holder in the X-axis direction and the Y-axis direction is used as the tangent point to the outer surface of the boss and the outer surface of the upper journal (1) to limit the position of the upper journal (1) in the X-axis and Y-axis. The exposed distance of the boss (3) at the upper journal (1) is calculated. The theoretical position of the center of the tool holder is obtained by calculation. Each time, the tool holder is moved to a fixed position and the outer contour of the tool holder is in contact with the flow channel surface of the boss (3) and the upper journal (1) at the maximum value in the X-axis and Y-axis directions. The origin of the double journal blade surface machining is found.

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