Miniature turbojet engine centrifugal machine case group batch manufacturing method

Abstract

The invention discloses a batch manufacturing method for centrifugal machine cases of a micro turbojet engine, which comprises the following steps of: 1, designing five centrifugal machine cases as a group, and preparing plate blanks according to corresponding specifications and dimensions; 2, outer circles, inner circles and end face positioning faces of all parts of the centrifugal machine boxes are milled, and bridge type connecting bosses between all the centrifugal machine boxes in the same direction are milled; 3, the blank is cut through linear cutting; 4, a bench worker goes to a bridge type connecting boss between the centrifugal machine boxes in the same direction; step 5, loading on a numerical control lathe and a numerical control milling machine to finish a subsequent semi-finishing process; and 6, a numerical control lathe and a numerical control milling machine finish subsequent finish machining procedures. Five centrifugal machine cases can be machined at a time, the material consumption of the centrifugal machine case of the micro turbojet engine can be reduced by 17%, compared with single-piece machining, the clamping and aligning frequency is reduced, the machining efficiency is greatly improved, the final product specification is consistent, and the product quality can be effectively guaranteed.

Description

Technical Field

[0001] This invention relates to the field of manufacturing technology for key components of aero-engines, specifically to a batch manufacturing method for centrifuge casings of a micro turbojet engine. Background Technology

[0002] Miniature turbojet engines are commonly used in unmanned aerial vehicles (UAVs), with high demand in both military and civilian markets, making them highly sensitive to manufacturing costs. The centrifuge casing is a core component of the compressor in a miniature turbojet engine, integrating aerodynamics, structure, and thermal management. Its design and manufacturing level directly affects the engine's efficiency, thrust, weight, reliability, and lifespan. Under the premise of meeting design and manufacturing technical requirements, its manufacturing cost directly determines whether the product can meet market demand.

[0003] Conventional manufacturing processes for centrifuge casings in micro turbojet engines involve machining single-piece bar stock. First, the general shape of the centrifuge casing is machined on a CNC lathe, then the sensor mounting base, assembly lugs, and mounting flange edges are machined on a CNC milling machine. This conventional process, primarily based on turning, results in significant material removal and low material utilization. Therefore, there is an urgent need to develop a process that meets manufacturing requirements, significantly improves machining efficiency, and saves materials to substantially reduce manufacturing costs. Summary of the Invention

[0004] The purpose of this invention is to provide a batch manufacturing method for centrifuge casings of micro turbojet engines. By using an efficient batch processing route and method, the processing efficiency of centrifuge casings of micro turbojet engines is improved, and the manufacturing cost is reduced by increasing material utilization.

[0005] The present invention is implemented as follows:

[0006] A method for batch manufacturing of centrifuge casings for a micro turbojet engine includes the following steps:

[0007] Step 1: Taking advantage of the T-shaped cross-section of the centrifuge casing, design a group of 5 centrifuge casings, with 3 centrifuge casings designed to face upwards and 2 centrifuge casings designed to face downwards, and prepare sheet metal blanks according to the corresponding specifications and dimensions.

[0008] Step 2: According to the designed centrifuge casing position distribution, while the sheet metal blank is in the blank state, mill out the outer circle, inner circle and end face positioning surface of each part of the centrifuge casing, and mill out the bridge-type connecting boss between centrifuge casings in the same direction.

[0009] Step 3: Use wire cutting to divide the blank;

[0010] Step 4: The fitter removes the bridge-type connecting boss between the centrifuge casings in the same direction;

[0011] Step 5, the subsequent semi-finishing process is completed by the numerical control lathe and the numerical control milling machine;

[0012] Step 6, the subsequent finishing process is completed by the numerical control lathe and the numerical control milling machine.

[0013] In step 1 of the present application, the optimal topological layout scheme is designed by deeply mining the geometric symmetry and complementarity of specific parts, and the discrete single-piece manufacturing task is integrated into an intensive sheet processing task, so that the raw materials are saved to the greatest extent at the source. The geometric optimization of topological layout follows the principle of shape complementarity and minimum gap. The "T" shaped profile of the centrifuge case side provides the possibility for shape complementarity of the upright and inverted states. The protruding part of the upright part ("T" top) provides a containing position for the recessed part of the inverted part (the space formed after the "T" bottom is turned over). This concave-convex interlocking geometric relationship is the basis for realizing profile complementary nesting. In traditional single-piece bar or simple side-by-side sheet processing, a large amount of process waste will be generated outside the part profile. Through the specific combination of 3 upright and 2 inverted, the present application innovatively makes the profile lines of adjacent parts close to each other or even partially coincide, compresses the gap area that would otherwise become waste to the theoretical minimum, and improves the utilization rate of sheet materials.

[0014] In step 2 of the present application, the global unified reference and separable physical connection are constructed simultaneously in the intensive rough machining stage to realize the precision guarantee and efficient segmentation of the subsequent process. In traditional single-piece processing, each part needs to be independently aligned and a machining reference is established, which has cumulative errors. In this scheme, the outer circle, inner circle and end face positioning surface of all five parts are milled in the sheet blank stage. The fundamental principle is to establish a unique and common geometric reference when the material is still integrated.

[0015] The outer circle and the inner circle define the unified coordinate system of the whole set of parts in the radial (X / Y) direction, and all subsequent machining with the center of the circle as the reference inherits this reference, completely eliminating the concentricity deviation caused by repeated clamping of individual parts. The end face positioning surface defines the unified reference surface of the whole set of parts in the axial (Z) direction. This ensures that the machining allowance of all parts in the thickness direction is consistent, providing accurate height positioning reference for subsequent wire cutting. This step prepositions and integrates the dispersed "individual reference" established subsequently into "overall reference", ensuring the accuracy consistency and inheritance between parts and processes in the source, and ensuring that the centrifuge case has the same specifications.

[0016] Step 3 of this invention utilizes precision cutting technology without mechanical stress to achieve the lossless transfer and inheritance of high-precision datum from the "integral blank group" to the "independent single blank," realizing the precise migration from the overall datum to the individual datum. This solution presupposes that the blank already possesses pre-fabricated high-precision datums (outer circle, inner circle, and end face). The core of wire EDM segmentation technology lies in the fact that its processing does not generate macroscopic mechanical cutting forces. Traditional sawing and milling segmentation produce significant lateral forces and vibrations, easily causing micro-displacement or deformation in weak parts fixed only by "bridge-type connecting bosses," thus rendering the previously uniformly milled precision datum surface meaningless. Wire EDM relies on extremely fine metal wires for discharge etching, with negligible force, ensuring that the relative position of each part to the pre-fabricated datum surface remains unchanged throughout the segmentation process. This fundamentally eliminates the cumulative error caused by inconsistent datums, improving the dimensional consistency of the final parts.

[0017] Compared with the prior art, the present invention has at least the following outstanding technical effects:

[0018] The present invention provides a batch manufacturing method for centrifuge casings of micro turbojet engines, which can process 5 centrifuge casings at a time, reducing the material consumption of the micro turbojet engine centrifuge casings by 17%. Compared with single-piece processing, it reduces the number of clamping and alignment times, greatly improves processing efficiency, and ensures that the final product specifications are consistent and the product quality can be effectively guaranteed. Attached Figure Description

[0019] Various objects, features, and advantages of the invention will become more apparent from the following detailed description of preferred embodiments of the invention, taken in conjunction with the accompanying drawings. The drawings are merely illustrative of the invention and are not necessarily drawn to scale.

[0020] Figure 1 This is a schematic diagram of the batch processing blank design for a centrifuge casing assembly according to an embodiment of the present invention.

[0021] Figure 2 This is a diagram illustrating the batch processing steps of a centrifuge casing assembly according to an embodiment of the present invention.

[0022] Figure 3 This is a schematic diagram of a rough milling and wire EDM cutting of a blank according to an embodiment of the present invention. Detailed Implementation

[0023] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit the present invention or its application or use. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0024] Techniques, methods, and equipment known to those skilled in the art may not be discussed in detail, but where appropriate, such techniques, methods, and equipment should be considered part of the specification.

[0025] As attached Figure 2 The diagram illustrates the specific steps of a batch manufacturing method for a micro turbojet engine centrifuge casing according to an embodiment of the present invention, including:

[0026] Step 1: Utilizing the T-shaped shape of the centrifuge casing, design a layout of 5 blanks, with 3 facing upwards and 2 facing downwards, and prepare the materials according to the design dimensions. The X / Y direction spacing between adjacent centrifuge casings should be sufficient to allow the milling cutter to pass through in Step 2. Specifically, the X-direction spacing between the three upright centrifuge casings (1-1, 1-2, 1-3) should be ≥14mm, and the X-direction spacing between the two inverted centrifuge casings (2-1, 2-2) should be ≥14mm. The Z-direction spacing between the three upright centrifuge casings and the two inverted centrifuge casings should be ≥5mm. To compensate for the potential impact of blank material deformation and processing errors, the distance between the centrifuge casing and the material boundary should be ≥3mm.

[0027] Step 2: In the blank state of the sheet metal, use a D8 or D12 milling cutter (diameters of 8mm and 12mm respectively) to mill out the outer circle, inner circle and end face positioning surface of each centrifuge casing, leaving a margin of ≥1mm. Mill out the bridge-type connecting boss between each centrifuge casing in the same direction. The boss width is 10mm, the overall thickness of the boss is 3mm, the length of the bridging part is the diameter of the milling cutter, and the thickness of the bridging part is 0.5mm.

[0028] Step 3: Use wire EDM to cut the blank with the pre-made reference. When the cutting thickness exceeds 100mm, use an electrode wire with a diameter of 0.25mm. Thicker wires have better rigidity and are less prone to vibration during deep cutting, which helps maintain stable processing and straightness.

[0029] Step 4: The fitter removes the bridge-type connecting boss between parts moving in the same direction;

[0030] Step 5: Complete the subsequent semi-finishing process on a CNC machining center (or CNC lathe, CNC milling machine);

[0031] Step 6: Complete the subsequent finishing process on a CNC machining center (or CNC lathe or CNC milling machine).

[0032] Steps 4-6 are conventional technical solutions well known to those skilled in the art. Those skilled in the art can perform corresponding operations according to the actual situation. As long as the corresponding operating procedures are met, the basic purpose of the present invention can be achieved. They will not be elaborated here.

[0033] Although the present invention has been described herein with reference to illustrative embodiments, the above embodiments are merely preferred embodiments of the present invention, and the implementation of the present invention is not limited to the above embodiments. It should be understood that those skilled in the art can devise many other modifications and implementations, which will fall within the scope and spirit of the principles disclosed in this application.

Claims

1. A method of batch manufacturing a micro turbojet engine centrifugal casing, characterized in that It comprises the following steps: Step 1, using the shape characteristics of the T-shaped cross section of the centrifuge box, design 5 centrifuge boxes as a group, of which 3 centrifuge boxes are designed as front up, 2 centrifuge boxes are designed as front down, and prepare the plate blank according to the corresponding size; Step 2, according to the designed position distribution of the centrifuge box, mill the outer circle, inner circle and end face positioning surface of each part of the centrifuge box in the state of the plate blank, and mill the bridge connection boss between each same direction centrifuge box; Step 3, use wire cutting to separate the blank; Step 4, remove the bridge connection boss between the same direction centrifuge boxes by bench work; Step 5, complete the subsequent semi-finishing process on the numerical control lathe and numerical control milling machine; Step 6, complete the subsequent finishing process on the numerical control lathe and numerical control milling machine.

2. The batch manufacturing method of the micro turbojet engine centrifuge box according to claim 1, wherein: In step 1, the X / Y direction layout gap between adjacent centrifuge boxes can meet the requirement of the milling cutter passing through in step 2.

3. The batch manufacturing method of the micro turbojet engine centrifuge box according to claim 2, wherein: In step 1, the X direction gap between the three normal centrifuge boxes is ≥14mm, the X direction gap between the two inverted centrifuge boxes is ≥14mm, the Z direction gap between the three normal centrifuge boxes and the two inverted centrifuge boxes is ≥5mm, and the distance between the centrifuge box and the material boundary is ≥3mm.

4. The batch manufacturing method of the micro turbojet engine centrifuge box according to claim 1, wherein: In step 2, use D8 or D12 milling cutter to mill the outer circle, inner circle and end face positioning surface of each centrifuge box, leaving a margin of ≥1mm, mill the bridge connection boss between each same direction centrifuge box, the boss width is 10mm, the boss overall thickness is 3mm, the bridge part length is the diameter of the milling cutter, and the bridge part thickness is 0.5mm.

5. The batch manufacturing method of the micro turbojet engine centrifuge box according to claim 1, wherein: In step 3, select 0.25mm diameter electrode wire for wire cutting.

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