Finish machining forming cutter for throttling hole of fuel nozzle of airspace engine

Abstract

The utility model discloses a finish machining forming cutter for a throttle hole of a fuel nozzle of an airspace engine, which comprises a cutter bar. Three chamfering edges which are uniformly distributed along the central axis of the cutter bar and are used for machining chamfering holes, three first reaming edges which are uniformly distributed along the central axis of the cutter bar and are used for machining first cylindrical holes, and three main cutting edges which are uniformly distributed along the central axis of the cutter bar and are used for machining taper holes are sequentially arranged at the lower part of the cutter bar from top to bottom; the first reaming blades are evenly distributed along the central axis of the cutter bar and used for machining first cylindrical holes, the second reaming blades are evenly distributed along the central axis of the cutter bar and used for machining second cylindrical holes, the horizontal end blades are evenly distributed along the central axis of the cutter bar and used for machining flat-bottom end faces, the blade inclination angle of each horizontal end blade is 0 degree, and the chamfering blades, the first reaming blades, the main cutting blades, the second reaming blades and the central axis of the cutter bar are coaxially arranged. According to the utility model, the central axes of the chamfered hole, the first cylindrical hole, the conical hole and the second cylindrical hole in the conical head large hole are coaxial with the central axis of the cylindrical bottom hole, and the planeness precision of the processed end face at the intersection of the cylindrical bottom hole and the second cylindrical hole is high.

Description

Technical Field

[0001] This utility model relates to a metal cutting tool for machining, and in particular to a finishing forming tool for the throttle hole of a fuel nozzle in an aerospace engine, belonging to the technical field of metal cutting tools. Background Technology

[0002] Aerospace engines are highly complex and precise thermodynamic machines. As the heart of an aircraft, they not only power flight but also serve as a vital driving force for the development of aviation. Every major transformation in the history of human aviation has been inseparable from technological advancements in engines.

[0003] The fuel nozzle throttling orifice of an aerospace engine includes a small-diameter cylindrical bottom hole and a large-diameter conical orifice. The conical orifice comprises, from top to bottom, a chamfered hole, a first cylindrical hole, a conical hole, and a second cylindrical hole. The intersection of the cylindrical bottom hole and the second cylindrical hole is a flat bottom face. The small-diameter cylindrical bottom hole is a pre-machined hole. When machining the large-diameter conical orifice, a chamfering drill, two milling cutters or reamers of different diameters, a taper drill or taper milling cutter, and an end mill are typically used. Machining chamfered holes, first cylindrical holes, tapered holes, and second cylindrical holes, as well as flat end faces, has two main drawbacks. First, due to the use of multiple cutting tools and repeated clamping, the central axes of the chamfered holes, first cylindrical holes, tapered holes, and second cylindrical holes are often not aligned with the central axis of the cylindrical bottom hole, leading to defective workpieces or even scrapping. Furthermore, the machining accuracy is low, making it difficult to meet process requirements. Second, the flatness accuracy of the end face at the intersection of the cylindrical bottom hole and the second cylindrical hole after machining is low, often failing to meet process requirements. Summary of the Invention

[0004] The technical problem to be solved by this utility model is to overcome the shortcomings of the prior art and provide a precision machining tool for the throttling hole of aerospace engine fuel nozzle that can ensure that the central axes of the chamfered hole, the first cylindrical hole, the conical hole and the second cylindrical hole in the large conical hole are coaxial with the central axis of the cylindrical bottom hole, and that the flatness accuracy of the end face at the intersection of the cylindrical bottom hole and the second cylindrical hole is high after machining, and has a simple structure and low manufacturing cost.

[0005] To solve the above-mentioned technical problems, this utility model employs a precision machining tool for aerospace engine fuel nozzle throttling orifices, including a tool holder. The fuel nozzle throttling orifice includes a cylindrical bottom hole with a small diameter section and a conical head hole with a large diameter section. The conical head hole includes a chamfered hole, a first cylindrical hole, a conical hole, and a second cylindrical hole arranged sequentially from top to bottom. The intersection of the cylindrical bottom hole and the second cylindrical hole is a flat bottom end face. Three holes for machining the chamfered holes are arranged sequentially from top to bottom along the central axis of the tool holder at the lower part of the tool holder. The tool holder has a chamfering edge, three first reaming edges evenly distributed along the central axis of the tool holder for machining the first cylindrical hole, three main cutting edges evenly distributed along the central axis of the tool holder for machining the tapered hole, three second reaming edges evenly distributed along the central axis of the tool holder for machining the second cylindrical hole, and three horizontal end edges evenly distributed along the central axis of the tool holder for machining the flat end face. The inclination angle of the horizontal end edges is 0°. The chamfering edge, the first reaming edge, the main cutting edge, and the second reaming edge are coaxial with the central axis of the tool holder.

[0006] In a preferred embodiment of this utility model, the rake angle of the main cutting edge is 0°.

[0007] In a preferred embodiment of this utility model, the included angle α of the chip removal grooves located between adjacent main cutting edges is 80° to 90°.

[0008] By adopting the above structure, this utility model has the following beneficial effects:

[0009] This utility model has three chamfering edges for machining chamfered holes, three first reaming edges for machining first cylindrical holes, three main cutting edges for machining tapered holes, three second reaming edges for machining second cylindrical holes, and three horizontal end edges for machining flat-bottomed faces, arranged sequentially from top to bottom on the lower part of the tool holder. During operation, the chamfering edge, the first reaming edge, the main cutting edge, and the second reaming edge are set coaxially with the central axis of the tool holder. The central axis of the tool holder is coaxial with the central axis of the cylindrical bottom hole. This effectively ensures that the central axes of the chamfering hole, the first cylindrical hole, the tapered hole, and the second cylindrical hole in the machined conical head are coaxial with the central axis of the cylindrical bottom hole, greatly improving the product qualification rate and machining accuracy requirements. Moreover, the inclination angle of the horizontal end edge of this utility model is 0°, which ensures high flatness accuracy of the end face at the intersection of the cylindrical bottom hole and the second cylindrical hole after machining.

[0010] This invention features, from top to bottom, three chamfering edges evenly distributed along the central axis of the tool holder for machining chamfered holes, three first reaming edges evenly distributed along the central axis of the tool holder for machining first cylindrical holes, three main cutting edges evenly distributed along the central axis of the tool holder for machining tapered holes, three second reaming edges evenly distributed along the central axis of the tool holder for machining second cylindrical holes, and three horizontal end edges evenly distributed along the central axis of the tool holder for machining flat-bottomed end faces. This three-edge odd-numbered cutting system ensures symmetrical force distribution on the tool during machining, reducing vibration marks.

[0011] The rake angle of the main cutting edge of this invention is 0°. This improves the surface finish of the machined area, better meeting process requirements, and also enhances the strength of the main cutting edge while reducing vibration.

[0012] In this invention, the included angle α of the chip removal grooves between adjacent main cutting edges is 80° to 90°. This increases the chip removal space and improves the tool cooling effect.

[0013] This invention has a simple structure, low manufacturing cost, and produces products without burrs or tool marks after processing. Attached Figure Description

[0014] The specific embodiments of this utility model will be further described in detail below with reference to the accompanying drawings.

[0015] Figure 1 This is a schematic diagram of a cutting tool for precision machining the throttling orifice of a fuel nozzle for an aerospace engine, according to the present invention.

[0016] Figure 2 for Figure 1 A diagram showing the view from below.

[0017] Figure 3 This is a schematic diagram of one structure of the throttling orifice in this utility model. Detailed Implementation

[0018] See Figures 1 to 3The tool shown is a precision machining tool for aerospace engine fuel nozzle throttling orifice, comprising a tool holder 1. The fuel nozzle throttling orifice includes a cylindrical bottom hole 7 with a small diameter section and a conical head hole 8 with a large diameter section. The conical head hole 8 includes, from top to bottom, a chamfered hole 8-1, a first cylindrical hole 8-2, a conical hole 8-3, and a second cylindrical hole 8-4, arranged sequentially. The intersection of the cylindrical bottom hole 7 and the second cylindrical hole 8-4 forms a flat bottom end face 8-5. Three chamfering edges 2 are arranged sequentially from top to bottom along the central axis 1-1 of the tool holder 1 for machining the chamfered hole 8-1. The tool holder 1 has three primary reaming edges 3 evenly distributed along its central axis 1-1 for machining the first cylindrical hole 8-2, three secondary reaming edges 4 evenly distributed along its central axis 1-1 for machining the tapered hole 8-3, three secondary reaming edges 5 evenly distributed along its central axis 1-1 for machining the second cylindrical hole 8-4, and three horizontal end edges 6 evenly distributed along its central axis 1-1 for machining the flat end face 8-5. The inclination angle of the horizontal end edges 6 is 0°. The chamfering edges 2, the first reaming edges 3, the primary cutting edges 4, and the second reaming edges 5 are coaxially arranged with the central axis 1-1 of the tool holder 1. In this invention, the three chamfering edges 2 and the three primary cutting edges 4 are all tapered.

[0019] In a preferred embodiment of this invention, the clearance angle of the flank face of the main cutting edge 4 is 0°. This improves the surface finish of the machined area, enhances the strength of the main cutting edge 4, and reduces vibration.

[0020] As a preferred embodiment of this utility model, such as Figure 2 As shown, the included angle α of the chip removal grooves located between adjacent main cutting edges 4 is 80° to 90°. This increases the chip removal space and improves the tool cooling effect.

[0021] After trial use, this utility model has a simple structure and can ensure that the central axes of the chamfered hole, the first cylindrical hole, the conical hole and the second cylindrical hole in the large hole of the conical head are coaxial with the central axis of the cylindrical bottom hole. The flatness accuracy of the end face at the intersection of the cylindrical bottom hole and the second cylindrical hole after machining is high, and the tool cooling effect is good, thus achieving good practical results.

Claims

1. A tool for precision machining a throttling orifice of a fuel nozzle for an aerospace engine, comprising a tool holder (1), wherein the throttling orifice of the fuel nozzle comprises a cylindrical bottom hole (7) of a small diameter section and a conical large hole (8) of a large diameter section, wherein the conical large hole (8) comprises, from top to bottom, a chamfered hole (8-1), a first cylindrical hole (8-2), a conical hole (8-3), and a second cylindrical hole (8-4), wherein the intersection of the cylindrical bottom hole (7) and the second cylindrical hole (8-4) is a flat bottom end face (8-5), characterized in that: The lower part of the tool holder (1) is provided with three chamfering edges (2) evenly distributed along the central axis (1-1) of the tool holder (1) for machining the chamfered hole (8-1), three first reaming edges (3) evenly distributed along the central axis (1-1) of the tool holder (1) for machining the first cylindrical hole (8-2), three main cutting edges (4) evenly distributed along the central axis (1-1) of the tool holder (1) for machining the tapered hole (8-3), and three cutting edges (5) evenly distributed along the central axis (1-1) of the tool holder (1) for machining the tapered hole (8-3). The tool holder (1) has a second reaming edge (5) evenly distributed along its central axis (1-1) for machining the second cylindrical hole (8-4), and three horizontal end edges (6) evenly distributed along its central axis (1-1) for machining the flat end face (8-5). The inclination angle of the horizontal end edges (6) is 0°. The chamfering edge (2), the first reaming edge (3), the main cutting edge (4), and the second reaming edge (5) are coaxial with the central axis (1-1) of the tool holder (1).

2. The precision machining tool for the throttle orifice of aerospace engine fuel nozzle according to claim 1, characterized in that: The back angle of the main cutting edge (4) is 0°.

3. The precision machining tool for the throttle orifice of aerospace engine fuel nozzle according to claim 1 or 2, characterized in that: The included angle α of the chip grooves located between adjacent main cutting edges (4) is 80° to 90°.

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