Machining method for high-precision fuel oil flow channel of aero-engine fuel oil nozzle swirler

Abstract

The invention relates to the technical field of precision machining and aero-engine manufacturing, and discloses a machining method of a high-precision fuel runner of an aero-engine fuel nozzle swirler, which comprises the following steps: primarily machining a bar raw material to obtain a semi-finished swirler with a stepped conical surface; and then a plurality of rectangular fuel oil flow channels which are uniformly distributed are formed in the stepped conical surface. According to the method, the problems that a remelting layer which is not easy to remove appears on a machining surface and the precision is poor due to the adoption of traditional linear cutting and electric spark machining processes can be avoided; and the bottom surface of the rectangular fuel oil flow channel is in a semicircular shape or a horn mouth shape. The negative factors that the electromachining process is poor in precision, the appearance does not meet the requirement and the like can be effectively solved, and the appearance requirement and the size precision of an ultra-thin and high-precision fuel flow channel of a fuel nozzle swirler of an aero-engine can be guaranteed.

Description

Technical Field

[0001] The invention relates to the technical field of precision machining and aeroengine manufacturing, and in particular to a method for machining a high-precision fuel flow channel of a fuel nozzle swirler of an aeroengine. Background Art

[0002] In aircraft engines, swirlers are mainly used in fuel supply systems, especially in the process of fuel mixing and atomization. It uses the principle of rotating fluid to fully mix fuel and air, ensuring the fuel atomization effect in the engine combustion chamber, thereby improving combustion efficiency and reducing emissions. The swirler in an aircraft engine is usually installed in front of the fuel nozzle. Its main function is to disperse the fuel into small droplets through the centrifugal force generated by the rotating air flow. This can increase the contact area between fuel and air, ensuring more complete and uniform combustion.

[0003] The existing ultra-fine, high-precision fuel flow channel processing technology generally adopts electrical machining, namely wire cutting and electric spark. The electrical machining process will cause a remelting layer to appear on the processing surface, which is difficult to remove and has excessive precision; the wire cutting process will cause the surface of the fuel flow channel to be semicircular; the electric spark machining process will cause the fuel flow channel to have a "trumpet-shaped" shape. The above shortcomings do not meet the requirements of the shape and size of the ultra-fine, high-precision fuel flow channel, affecting the injection volume and atomization cone angle of the aircraft engine fuel nozzle. Summary of the invention

[0004] The purpose of the present invention is to provide a method for processing a high-precision fuel flow channel of an aircraft engine fuel nozzle swirler, so as to solve the problems that the use of conventional processing technology will result in a remelted layer that is difficult to remove on the processing surface, poor precision; and the bottom surface of the rectangular fuel flow channel is semicircular and has a "bell-mouth" appearance.

[0005] The present invention is realized by the following technical scheme: a method for processing a high-precision fuel flow channel of a swirler of an aircraft engine fuel nozzle, comprising: performing preliminary processing on a rod raw material to obtain a semi-finished swirler with a stepped conical surface, and then opening a plurality of uniformly distributed rectangular fuel flow channels on the stepped conical surface; specifically comprising: Step S1, clamping the selected bar material on a machine tool, and using the machine tool to sequentially process the bar material into four sides, a first cylindrical surface, a first conical surface, a second cylindrical surface, a second conical surface, an oil inlet plane, and an oil guide conical surface to obtain a semi-finished cyclone; Step S2, using a clamping tool to clamp the semi-finished cyclone, and then clamping the tool on a five-axis machining center; Step S3, a five-axis machining center uses a tool to machine a rectangular fuel flow channel on the semi-finished cyclone in a rough-first-then-fine manner, wherein the starting end of the rectangular fuel flow channel is located on the oil inlet plane, and the ending end is located on the first cylindrical surface.

[0006] In order to better realize the present invention, further, the method of roughing first and then finishing in step 3 is specifically as follows: during roughing, a layered processing method is adopted, and the processing depth of each layer is controlled at 0.3mm; then semi-finishing is performed in the same layered processing method, and the processing depth of each layer is controlled at 0.1mm, leaving a margin of 0.01mm on the side and bottom of the rectangular fuel flow channel; finally, finishing is performed, and the finishing requires one-time processing.

[0007] In order to better implement the present invention, further, the distance between the side of the rectangular fuel flow channel finally obtained in the step S3 and the axis of the swirler is 0.8±0.05mm, the distance between the starting end of the rectangular fuel flow channel and the axis of the swirler is 0.79±0.05mm, the width of the rectangular fuel flow channel is 0.26±0.01mm, the angle formed by the bottom surface of the rectangular fuel flow channel and the axis of the swirler is 143.2°±10′, the maximum depth of the rectangular fuel flow channel is 0.41mm, and the total length is 2.37mm.

[0008] In order to better implement the present invention, further, the blade length of the tool in step S3 is 0.05-0.1 mm greater than the depth of the rectangular fuel flow channel.

[0009] In order to better implement the present invention, further, the ratio of the blade length to the diameter of the tool is 2.5:1.

[0010] In order to better implement the present invention, further, the diameter of the tool is 0.2 mm and the blade length is 0.5 mm.

[0011] In order to better implement the present invention, further, the clamping positioning accuracy of the clamping tool in step S2 is 0.0005 mm.

[0012] In order to better implement the present invention, further, the material of the rod raw material described in step S1 is 9Cr18Mo, and after quenching and tempering treatment, the hardness is ≥50HRC.

[0013] Compared with the prior art, the present invention has the following advantages and beneficial effects: (1) The present invention can avoid the problems of difficult-to-remove remelting layer and poor precision on the machining surface caused by the use of traditional wire cutting and electrical spark machining processes, as well as the semicircular and "bell-mouth" appearance of the bottom surface of the rectangular fuel flow channel. It can effectively solve the unfavorable factors such as poor precision of the electrical machining process and non-compliant appearance, and can ensure that the aircraft engine fuel nozzle swirler is extremely fine and high-precision. The fuel flow channel shape requirements and dimensional accuracy; (2) The present invention can improve the production efficiency of the cyclone by setting a special tool size, while preventing the tool from chipping and the like. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is a schematic diagram of the process of the present invention.

[0015] Figure 2 Schematic diagram of the overall structure of the cyclone.

[0016] Figure 3 It is a schematic diagram of the overall structure of the cyclone from a front view.

[0017] Figure 4 It is a schematic diagram of the overall structure of the cyclone from a left angle.

[0018] Figure 5 It is a cross-sectional view of the overall structure of the cyclone from a front view angle.

[0019] Figure 6 Schematic diagram of tool structure.

[0020] Among them: 101-four sides; 102-first cylindrical surface; 103-first conical surface; 104-second conical surface; 105-oil inlet plane; 106-oil guide conical surface; 107-second cylindrical surface; 108-rectangular fuel flow channel; 11-tool. DETAILED DESCRIPTION

[0021] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0022] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be an indirect connection through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0023] Embodiment 1: This embodiment provides a method for machining a high-precision fuel flow channel of a fuel nozzle swirler of an aircraft engine, specifically, Figure 1-Figure 6As shown, the rod material is preliminarily processed to obtain a semi-finished cyclone with a stepped cone surface, and then a plurality of evenly distributed rectangular fuel flow channels 108 are opened on the stepped cone surface; in this embodiment, four rectangular fuel flow channels 108 are specifically selected, and the structural characteristics of the entire cyclone belong to a rotating body, with a maximum diameter of 5.4 mm, a minimum diameter of 0.88 mm, and a total length of 9.48 mm, and specifically includes: Step S1, clamping the selected bar material on a machine tool, and using the machine tool to sequentially process the bar material into four sides 101, a first cylindrical surface 102, a first conical surface 103, a second cylindrical surface 107, a second conical surface 104, an oil inlet plane 105, and an oil guide conical surface 106 to obtain a semi-finished cyclone; wherein the processing technology of the four sides 101 can be selected to be CNC milling or wire cutting, and rounding treatment is performed, and the shape and position tolerance symmetry is required to be 0.01mm; Step S2, using a clamping tool to clamp the semi-finished cyclone, and then clamping the tool on a five-axis machining center, wherein the clamping positioning accuracy of the clamping tool is 0.0005 mm; Step S3, the five-axis machining center uses the tool 11 to machine a rectangular fuel flow channel 108 on the semi-finished cyclone in a rough-first-then-fine manner, wherein the starting end of the rectangular fuel flow channel 108 is located on the oil inlet plane 105 and the ending end is located on the first cylindrical surface 102, and the machining is completed.

[0024] When the swirler is installed in the nozzle, the second cylindrical surface 107 is inserted into the nozzle, and the second conical surface 104 cooperates with the fuel outlet in the nozzle to form a sealing surface to ensure that the fuel can only flow from the rectangular fuel flow channel 108, and the oil guide conical surface 106 is used to control the fuel flow rate flowing into the rectangular fuel flow channel 108; the oil guide conical surface 106 cooperates with the nozzle to form a first section of the flow channel, where the fuel is accelerated and rotated, and then enters the second section of the flow channel composed of multiple rectangular fuel flow channels 108, and then sprayed out in atomization.

[0025] The above-mentioned processing method can avoid the problems of difficult-to-remove remelting layer and precision tolerance on the processing surface caused by wire cutting and electrospark machining processes, as well as the semicircular and "bell-mouth" appearance of the bottom surface of the rectangular fuel flow channel 108. It can effectively solve the unfavorable factors such as poor electromachining process accuracy and appearance that does not meet the requirements, and can ensure the extremely fine and high-precision fuel flow channel appearance requirements and dimensional accuracy of the aircraft engine fuel nozzle swirler.

[0026] Embodiment 2: This embodiment is further expanded on the basis of the above embodiment. The method of roughing first and then finishing in step 3 is specifically as follows: roughing is performed in a layered processing manner, and the processing depth of each layer is controlled at 0.3mm; then semi-finishing is performed in a layered processing manner, and the processing depth of each layer is controlled at 0.1mm, leaving a margin of 0.01mm on the side and bottom of the rectangular fuel flow channel 108; finally, finishing is performed, and finishing requires one-time processing. Processing by this method can reduce the contact stress between the tool 11 and the cyclone, avoid damage to the tool 11, and take into account both processing speed and processing quality.

[0027] The other parts of this embodiment are the same as those of the above embodiment and will not be described in detail.

[0028] Embodiment 3: This embodiment is further expanded on the basis of the above embodiment. Figure 4 As shown, the distance between the side of the rectangular fuel flow channel 108 finally obtained in the step S3 and the axis of the swirler is 0.8±0.05mm, the distance between the starting end of the rectangular fuel flow channel 108 and the axis of the swirler is 0.79±0.05mm, the width of the rectangular fuel flow channel 108 is 0.26±0.01mm, the angle formed by the bottom surface of the rectangular fuel flow channel 108 and the axis of the swirler is 143.2°±10′, the maximum depth of the rectangular fuel flow channel 108 is 0.41mm, and the total length is 2.37mm.

[0029] The other parts of this embodiment are the same as those of the above embodiment and will not be described in detail.

[0030] Embodiment 4: The present embodiment is further expanded on the basis of the above-mentioned embodiment. Since the diameter of the tool 11 needs to be smaller than the width of the rectangular fuel flow channel 108, its blade length needs to be greater than the depth of the rectangular fuel flow channel 108 in order to complete the processing in one go and ensure sufficiently high precision, the blade length of the tool 11 in step S3 is 0.05-0.1mm greater than the depth of the rectangular fuel flow channel 108, and the ratio of the blade length to the diameter of the tool 11 is 2.5:1. Specifically, the diameter of the tool 11 is 0.2mm, and the blade length is 0.5mm.

[0031] The other parts of this embodiment are the same as those of the above embodiment and will not be described in detail.

[0032] Embodiment 5: This embodiment is further expanded on the basis of the above embodiment. The material of the rod raw material described in step S1 is 9Cr18Mo, which is a high-carbon chromium martensitic stainless steel material. After quenching and tempering, the hardness is ≥50HRC, and it has high hardness and wear resistance; small deformation, good dimensional stability, and strong corrosion resistance, which can ensure that the cyclone works stably under the working parameters.

[0033] The other parts of this embodiment are the same as those of the above embodiment and will not be described in detail.

[0034] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any form. Any simple modification or equivalent change made to the above embodiment based on the technical essence of the present invention shall fall within the protection scope of the present invention.

Claims

1. A method for processing a high-precision fuel flow channel of an aircraft engine fuel nozzle swirler, characterized in that: The method comprises preliminarily processing a rod material to obtain a semi-finished cyclone having a stepped conical surface, and then opening a plurality of evenly distributed rectangular fuel flow channels (108) on the stepped conical surface; specifically comprising: Step S1, clamping the selected bar material on a machine tool, and using the machine tool to sequentially process the bar material into four sides (101), a first cylindrical surface (102), a first conical surface (103), a second cylindrical surface (107), a second conical surface (104), an oil inlet plane (105), and an oil guide conical surface (106), to obtain a semi-finished cyclone; Step S2, using a clamping tool to clamp the semi-finished cyclone, and then clamping the tool on a five-axis machining center; Step S3: Using a tool (11) on a five-axis machining center, a rectangular fuel flow channel (108) is machined on the semi-finished cyclone in a roughing-first-then-finishing manner, wherein the starting end of the rectangular fuel flow channel (108) is located on the oil inlet plane (105), and the ending end is located on the first cylindrical surface (102).

2. The method for machining a high-precision fuel flow channel of an aircraft engine fuel nozzle swirler according to claim 1, characterized in that: The method of roughing first and then finishing in step 3 is specifically as follows: roughing is performed in a layered manner, with the depth of each layer controlled at 0.3 mm; semi-finishing is then performed in a layered manner, with the depth of each layer controlled at 0.1 mm, leaving a margin of 0.01 mm on the side and bottom of the rectangular fuel flow channel (108); and finishing is finally performed, with the finishing requiring one-time completion.

3. The method for machining a high-precision fuel flow channel of a swirler of an aircraft engine fuel nozzle according to claim 1, characterized in that: The distance between the side of the rectangular fuel flow channel (108) finally obtained in step S3 and the axis of the swirler is 0.8±0.05 mm, the distance between the starting end of the rectangular fuel flow channel (108) and the axis of the swirler is 0.79±0.05 mm, the width of the rectangular fuel flow channel (108) is 0.26±0.01 mm, the angle formed by the bottom surface of the rectangular fuel flow channel (108) and the axis of the swirler is 143.2°±10′, the maximum depth of the rectangular fuel flow channel (108) is 0.41 mm, and the total length is 2.37 mm.

4. The method for machining a high-precision fuel flow channel of a swirler of an aircraft engine fuel nozzle according to claim 1, characterized in that: In step S3, the blade length of the tool (11) is 0.05-0.1 mm greater than the depth of the rectangular fuel flow channel (108).

5. The method for machining a high-precision fuel flow channel of a swirler of an aircraft engine fuel nozzle according to claim 4, characterized in that: The ratio of the blade length to the diameter of the tool (11) is 2.5:

1.

6. The method for machining a high-precision fuel flow channel of a swirler of an aircraft engine fuel nozzle according to claim 5, characterized in that: The cutter (11) has a diameter of 0.2 mm and a blade length of 0.5 mm.

7. The method for machining a high-precision fuel flow channel of a swirler of an aircraft engine fuel nozzle according to claim 1, characterized in that: The clamping positioning accuracy of the clamping tool in step S2 is 0.0005 mm.

8. The method for machining a high-precision fuel flow channel of a swirler of an aircraft engine fuel nozzle according to claim 1, characterized in that: The material of the rod raw material described in step S1 is 9Cr18Mo, and after quenching and tempering, the hardness is ≥50HRC.

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