An aircraft refueling control valve nut internal thread repair device and method of manufacture

Abstract

The present application relates to the field of aviation equipment maintenance, and particularly relates to an aircraft refueling control valve nut inner thread repairing device and a manufacturing method thereof, which comprises a base plate, further comprises a positioning gyroscope connected with a piston and a screw tap tenon, a cylindrical gyroscope handle with the same shape as the through hole of the piston is arranged on the positioning gyroscope, and a gyroscope disc with the same shape as the groove of the piston is arranged on the positioning gyroscope, the shape of the positioning gyroscope is gyroscope, and the specific steps are as follows: S1, size design; S2, positioning gyroscope model creation; S3, model data processing; S4, 18Ni300 die steel powder preparation; S5, positioning gyroscope rapid preparation; S6, aircraft refueling control valve nut inner thread repairing device assembly; the positioning gyroscope with the size of the piston accessory and the screw tap accessory is designed to be gap fit with both, 18Ni300 maraging steel material is selected, laser selection melting forming technology is adopted for rapid manufacturing, and finally the aircraft refueling control valve nut inner thread repairing device with variable range of clamping angle is obtained.

Description

Technical Field

[0001] This invention relates to the field of aviation equipment maintenance, specifically to a device for repairing the internal threads of an aircraft refueling control valve nut and its manufacturing method. Background Technology

[0002] The nut is a component of the aircraft refueling control valve, connected to the piston via threads to cut off the fuel supply. Due to the severe, high-frequency vibrations generated during aircraft flight, to prevent loosening of the threaded connection and potential accidents, a safety break is performed on the threaded connection between the nut and piston before installation. This breaks the nut's threads to achieve a highly reliable connection. Therefore, during aircraft repair, the refueling control valve must be disassembled, and the threads of the safety break nut must be repaired. Currently, the main method for thread repair is manual repair using a tap. Repairing the threads requires ensuring the nut's axis is collinear with the tap's axis. However, there is a significant clearance between the tap's cutting surface and the nut being repaired. This presents the following challenges for direct tap thread repair: 1. The angle between the nut's axis and the tap's axis can vary widely, reaching a maximum of 20°; 2. Correctly aligning the nut and tap is difficult; 3. High skill level is required from the operator; 4. Secondary damage to the threads is easily caused during repair.

[0003] Selective laser melting forming technology is characterized by short manufacturing cycles and the ability to manufacture complex and detailed parts. MS1 maraging steel is characterized by low cost (200-300 RMB / kg), high deposition strength (≥1100MPa), high hardness (≥40HRC), and high elastic modulus (≥190GPa). Therefore, a nut internal thread repair device is designed according to the size of the nut and tap to be repaired, and maraging steel material is selected to be rapidly manufactured using selective laser melting forming technology. This enables rapid and personalized manufacturing of thread repair devices, ultimately reducing the variable range of the angle between the nut axis and the tap axis, reducing the difficulty of thread repair, and helping operators to efficiently repair the internal threads of nuts. Summary of the Invention

[0004] To address the aforementioned problems, this invention proposes a device for repairing the internal thread of an aircraft refueling control valve nut and its manufacturing method.

[0005] A device for repairing the internal thread of an aircraft refueling control valve nut includes a positioning gyroscope connected to a piston and a tap and tenon joint. The positioning gyroscope is provided with a cylindrical gyroscope shank with the same shape as the through hole of the piston and a gyroscope disk with the same shape as the groove of the piston. The positioning gyroscope is gyroscope-shaped.

[0006] Furthermore, the dimensions of the gyroscope handle and gyroscope disk are designed such that the gyroscope handle can penetrate the end face of the through hole after the positioning gyroscope is inserted into the piston.

[0007] Furthermore, the gap between the gyroscope disk of the positioning gyroscope and the grooved cylindrical surface of the piston is between 0 and 0.1 mm.

[0008] Furthermore, the gap between the gyroscope shank of the positioning gyroscope and the cylindrical surface of the piston through hole is between 0 and 0.1 mm.

[0009] Furthermore, the positioning gyroscope is provided with a gyroscope tip that is cone-shaped and has the same shape as the groove of the tap.

[0010] The gyroscope tip and the groove of the tap are fitted together with a clearance fit, and the fit size is between 0 and 0.1 mm.

[0011] The positioning gyroscope has a hole inside, and the minimum wall thickness of the positioning gyroscope must be ≥2mm during the hole-making process.

[0012] As another improvement of the present invention, a method for manufacturing a repair device for the internal thread of an aircraft refueling control valve nut includes the following specific steps:

[0013] S1. Size Design: Determine the size of the positioning gyroscope based on the dimensions of the piston and tap;

[0014] S2. Creating the positioning gyroscope model: Use 3D modeling software to create a 3D model of the positioning gyroscope and save the model as an STL file.

[0015] S3. Model Data Processing:

[0016] a. The positioning gyroscope is placed with the tip of the gyroscope pointing upwards, the shank pointing downwards, and the angle between the axis of symmetry and the base plate being 45 to 55 degrees.

[0017] b. Use slicing software to determine the areas in the positioning gyroscope model that need to be supported. Use columnar point supports, set the diameter of the columnar support and the connection end with the substrate to 0.8mm, and the diameter of the connection end with the positioning gyroscope to 0.4mm.

[0018] c. Save the model with added support as an STL file, repair the model, then slice and layer the model to generate the scan path;

[0019] S4, 18Ni300 mold steel powder preparation: The powder is homogeneous spherical micro powder with a particle size range of 15-53μm, and the presence of a small amount of satellite spherical powder is allowed;

[0020] S5. Rapid Fabrication of Positioning Gyroscopes: Positioning gyroscopes are fabricated using selective laser melting technology, with specific parameters as follows:

[0021] a. The process parameters for the internal filling part are: laser power of 270-320W, scanning speed of 900-1100mm / s, scanning spacing of 0.07-0.11mm, and powder layer thickness of 0.03-0.05mm;

[0022] b. The contouring process parameters are: laser power 200-250W and scanning speed 400-700mm / s;

[0023] The scaling factors in the c, X, Y, and Z directions are 1.00025 to 1.00040;

[0024] d. After the positioning gyroscope is formed, remove the support and take it off the base plate;

[0025] S6. Assembly of the internal thread repair device for the aircraft refueling control valve nut:

[0026] a. The piston used in the aircraft refueling control valve nut internal thread repair device is the same as the original piston of the aircraft refueling control valve. The piston and the nut to be repaired are mating parts.

[0027] b. During assembly, insert the gyroscope disk and gyroscope shank of the positioning gyroscope into the groove and through hole of the piston to make the positioning gyroscope collinear with the piston axis.

[0028] c. The tip of the positioning gyroscope is inserted into the groove two of the tap, and the surface one of the positioning gyroscope is in contact with the surface two of the tap, so as to make the positioning gyroscope and the tap axis collinear.

[0029] d. The positioning gyroscope is connected to the piston and tap using a mortise and tenon joint.

[0030] e. The selected tap is a standard specification tap determined according to the specifications of the nut to be repaired. After the nut to be repaired is tapped, the damaged threads will be repaired.

[0031] f. After assembling the piston and tap into one piece using a positioning gyroscope with mortise and tenon joints, the included angle between the central axes of the piston and tap is within the range of 0 to 2°.

[0032] Furthermore, in step S4, the 18Ni300 mold steel powder needs to be vacuum dried at a temperature of 100-110°C for 3-6 hours, with a Hall flow rate of <25s / 50g.

[0033] Furthermore, in step S6a, when repairing the nut to be repaired, the nut to be repaired needs to be connected to the piston by threads before assembling the internal thread repair device for the aircraft refueling control valve nut. When connecting, the end of the nut to be repaired that has not been subjected to the punching safety treatment faces the piston. After connection, the purpose of the nut to be repaired and the piston thread axis being collinear can be achieved.

[0034] The beneficial effects of this invention are as follows: a positioning gyroscope with clearance fit between the piston fitting and the tap fitting is designed according to their dimensions; 18Ni300 martensitic aging steel is selected; laser selective melting forming technology is used for rapid manufacturing; and finally, an aircraft refueling control valve nut internal thread repair device is assembled, which can reduce the variable range of the angle between the axis of the aircraft refueling control valve nut and the axis of the tap. Attached Figure Description

[0035] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0036] Figure 1 This is a schematic diagram of the main structure of the positioning gyroscope of the present invention;

[0037] Figure 2 This is a schematic diagram of the left side structure of the positioning gyroscope of the present invention;

[0038] Figure 3 This is a top view schematic diagram of the positioning gyroscope structure of the present invention;

[0039] Figure 4 For the present invention Figure 1 A schematic diagram of the AA structure;

[0040] Figure 5 For the present invention Figure 1 Schematic diagram of BB structure;

[0041] Figure 6 This is a schematic diagram of the positioning gyroscope placement structure of the present invention;

[0042] Figure 7 This is a schematic diagram of the main structure of the tap of the present invention;

[0043] Figure 8 For the present invention Figure 7 A schematic diagram of the CC structure;

[0044] Figure 9 For the present invention Figure 7 Schematic diagram of DD structure;

[0045] Figure 10 This is a schematic diagram of the piston structure of the present invention;

[0046] Figure 11 This is a schematic diagram of the piston structure of the present invention from the side.

[0047] Figure 12 For the present invention Figure 10 EE structure diagram;

[0048] Figure 13 This is a schematic diagram of the main structure of the nut internal thread repair device of the present invention;

[0049] Figure 14 For the present invention Figure 13 A schematic diagram of the FF structure. Detailed Implementation

[0050] To make the technical means, creative features, objectives and effects of this invention easier to understand, the invention will be further described below.

[0051] like Figures 1 to 14 As shown, an internal thread repair device for an aircraft refueling control valve nut includes a positioning gyroscope 1 that is mortised and tenoned with a piston 3 and a tap 4. The positioning gyroscope 1 is provided with a cylindrical gyroscope shank c that is the same shape as the through hole h of the piston 3 and a gyroscope disk a that is the same shape as the groove i of the piston 3. The positioning gyroscope 1 is gyroscope-shaped.

[0052] Based on the dimensions of piston 3 and tap 4, a positioning gyroscope 1 with clearance fit between them is designed. 18Ni300 martensitic aging steel is selected and laser selective melting forming technology is used for rapid manufacturing. Finally, an aircraft refueling control valve nut internal thread repair device is assembled, which can reduce the variable range of the angle between the axis of the aircraft refueling control valve nut and the axis of tap 4.

[0053] The dimensions of the gyroscope handle c and the gyroscope disk a are designed such that after the positioning gyroscope 1 is inserted into the piston 3, the gyroscope handle c can penetrate the end face of the through hole h.

[0054] The gap between the gyroscope disk a of the positioning gyroscope 1 and the groove-i cylindrical surface of the piston 3 is between 0 and 0.1 mm.

[0055] The gap between the gyroscope shank c of the positioning gyroscope 1 and the cylindrical surface of the through hole h of the piston 3 is between 0 and 0.1 mm.

[0056] The positioning gyroscope 1 is provided with a gyroscope tip b that is cone-shaped and has the same shape as the groove f of the tap 3.

[0057] The gyroscope tip b is fitted with the groove f of the tap 3, and the fit is a clearance fit with a fit dimension between 0 and 0.1 mm.

[0058] The positioning gyroscope 1 has a hole inside. During the hole-making process, the minimum wall thickness of the positioning gyroscope 1 must be ≥2mm. The purpose is to reduce manufacturing costs, shorten manufacturing time, reduce the weight of the positioning gyroscope 1, and at the same time ensure that the positioning gyroscope 1 has strong resistance to deformation.

[0059] A method for manufacturing a device for repairing the internal thread of an aircraft refueling control valve nut, comprising the following specific steps:

[0060] S1. Size Design: The size of the positioning gyroscope 1 is determined based on the dimensions of the piston 3 and the tap 4;

[0061] S2. Creating the Positioning Gyroscope 1 Model: Use 3D modeling software to create a 3D model of the positioning gyroscope 1 and save the model as an STL file.

[0062] S3. Model Data Processing:

[0063] a. The positioning gyroscope 1 is arranged with the gyroscope tip b facing upward, the gyroscope stem d facing downward, and the symmetry axis e forming an angle of 45 to 55° with the base plate 2;

[0064] b. Use slicing software to determine the area in the positioning gyroscope 1 model that needs to be supported. Use columnar point support and set the diameter of the columnar support and the connection end of the substrate 2 to 0.8mm and the diameter of the connection end of the positioning gyroscope 1 to 0.4mm. The purpose is to ensure low roughness of the mating surface, no deformation during part forming, and easy removal from the substrate.

[0065] c. Save the model with added support as an STL file, repair the model, then slice and layer the model to generate the scan path;

[0066] S4, 18Ni300 mold steel powder preparation: The powder is homogeneous spherical micro powder with a particle size range of 15-53μm, and the presence of a small amount of satellite spherical powder is allowed;

[0067] S5. Rapid fabrication of positioning gyroscope 1: Positioning gyroscope 1 is fabricated using selective laser melting technology, with the following specific parameters:

[0068] a. The process parameters for the internal filling part are: laser power of 270-320W, scanning speed of 900-1100mm / s, scanning interval of 0.07-0.11mm, and powder layer thickness of 0.03-0.05mm. The purpose is to ensure that the internal filling part is formed quickly and with few defects.

[0069] b. The contour process parameters are laser power of 200-250W and scanning speed of 400-700mm / s, in order to ensure that the surface roughness of the formed positioning gyroscope 1 is low.

[0070] The scaling factors in the c, X, Y, and Z directions are 1.00025 to 1.00040, the purpose of which is to ensure that the difference between the actual formed size and the design size of the positioning gyroscope 1 is within the range of -0.03 to 0.03 mm;

[0071] d. After the positioning gyroscope 1 is formed, remove the support and take it off the base plate 2;

[0072] S6. Assembly of the internal thread repair device for the aircraft refueling control valve nut:

[0073] a. The piston 3 used in the aircraft refueling control valve nut internal thread repair device is the same as the original piston of the aircraft refueling control valve. The piston 3 and the nut to be repaired are mating parts.

[0074] b. During assembly, insert the gyroscope disk c and gyroscope handle d of the positioning gyroscope 1 into the groove i and through hole h of the piston 3 to make the positioning gyroscope 1 and the piston 3 axis collinear.

[0075] c. The tip b of the positioning gyroscope 1 is inserted into the groove f of the tap 4, and the surface a of the positioning gyroscope 1 is in contact with the surface g of the tap 4, which makes the axis of the positioning gyroscope 1 and the tap 4 collinear.

[0076] d. The positioning gyroscope 1 is connected to the piston 3 and tap 4 by mortise and tenon joints, which makes the parts easy to disassemble, carry and store.

[0077] e. The selected tap 4 is a standard tap of a size determined according to the specifications of the nut to be repaired. After the nut to be repaired is tapped by tap 4, the damaged threads will be repaired.

[0078] f. After the piston 3 and tap 4 are assembled into one piece using the positioning gyroscope 1 with mortise and tenon joints, the included angle between the central axes of the piston 3 and tap 4 is within the range of 0 to 2°.

[0079] In step S3, the spatial arrangement of the positioning gyroscope 1 is shown in the diagram below. Figure 6 As shown, the purpose of this arrangement is to ensure that the surfaces of the positioning gyroscope 1 that mate with the piston 3 and tap 4 do not require additional support, thus eliminating the need for post-forming grinding and reducing the number of powder layers required for forming, thereby shortening the preparation time of the positioning gyroscope 1.

[0080] Table 1 Performance of Deposited Molded Parts

[0081]

[0082] Selective laser melting forming of 18Ni300 mold steel results in high deposited strength (≥1100MPa), high hardness (≥40HRC), and high elastic modulus (≥190GPa). Positioning gyroscopes formed from this material do not require subsequent heat treatment to meet usage requirements, and the manufacturing cycle is shortened by more than 50% compared to traditional machining.

[0083] Table 2 Weight Reduction Table for Positioning Gyroscopes

[0084] Manufacturing method weight cycle Manufacturing costs Traditional machining 0.62Kg 13 days 500 yuan Selective laser melting forming 0.44Kg 6 days 300 yuan

[0085] The comprehensive cost of the selective laser melting forming positioning gyroscope 1 is 200-300 yuan per unit. The positioning gyroscope 1 manufactured using the forming process in this patent does not require subsequent grinding to achieve the surface roughness required for use. Compared with traditional machining, the cost is reduced by 40% and the production cycle is shortened by 7 days.

[0086] After using the nut internal thread repair device, the variable range of the angle between the nut axis and the tap axis was reduced from 0-20° before use to 0-2°. The qualified rate of the repaired nut increased from 73% before use to 100%, which greatly reduced the repair difficulty and improved the repair efficiency.

[0087] In step S4, the 18Ni300 mold steel powder needs to be vacuum dried at a temperature of 100-110°C for 3-6 hours, with a Hall flow rate of <25s / 50g.

[0088] In step S6a, when repairing the nut to be repaired, the nut to be repaired needs to be connected to the piston 3 by thread before assembling the internal thread repair device for the aircraft refueling control valve nut. When connecting, the end of the nut to be repaired that has not been punched for safety treatment faces the piston 3. After connection, the purpose of the nut to be repaired and the piston 3 thread axis being collinear can be achieved.

[0089] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely prisms of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the present invention as claimed. The scope of protection of this invention is defined by the appended claims and their equivalents.

Claims

1. A method for manufacturing a device for repairing the internal thread of an aircraft refueling control valve nut, characterized in that: The specific steps are as follows: S1. Size design: The size of the positioning gyroscope (1) is determined according to the size of the piston (3) and the tap (4); S2, Model creation of positioning gyroscope (1): Use 3D modeling software to create a 3D model of positioning gyroscope (1) and save the model as an STL file; S3. Model Data Processing: a. The positioning gyroscope (1) is placed with the gyroscope tip (b) facing up, the gyroscope stem (d) facing down, and the angle between the axis of symmetry (e) and the base plate (2) being 45 to 55 degrees. b. Use slicing software to determine the area in the positioning gyroscope (1) model that needs to be supported, use columnar point support, set the diameter of the columnar support and the connection end of the substrate (2) to 0.8mm, and the diameter of the connection end of the positioning gyroscope (1) to 0.4mm; c. Save the model with added support as an STL file, repair the model, then slice and layer the model to generate the scan path; S4, 18Ni300 mold steel powder preparation: The powder is homogeneous spherical micro powder with a particle size range of 15~53μm, and the presence of a small amount of satellite spherical powder is allowed; S5. Rapid fabrication of positioning gyroscope (1): Positioning gyroscope (1) is fabricated using selective laser melting forming technology, with the following specific parameters: a. The process parameters for the internal filling part are: laser power of 270-320W, scanning speed of 900-1100mm / s, scanning spacing of 0.07-0.11mm, and powder layer thickness of 0.03-0.05mm; b. The contouring process parameters are: laser power 200~250W, scanning speed 400~700mm / s; The scaling factors in the c, X, Y, and Z directions are 1.00025 to 1.00040; d. After the positioning gyroscope (1) is formed, remove the support and take it off the base plate (2); S6. Assembly of the internal thread repair device for the aircraft refueling control valve nut: a. The piston (3) used in the aircraft refueling control valve nut internal thread repair device is the same as the original piston of the aircraft refueling control valve. The piston (3) and the nut to be repaired are mating parts. b. During assembly, insert the gyroscope disk (c) and gyroscope handle (d) of the positioning gyroscope (1) into the groove (i) and through hole (h) of the piston (3) to make the positioning gyroscope (1) and piston (3) collinear. c. The tip (b) of the positioning gyroscope (1) is inserted into the groove (f) of the tap (4), and the surface (a) of the positioning gyroscope (1) is in contact with the surface (g) of the tap (4), which serves to make the axis of the positioning gyroscope (1) and the tap (4) collinear. d. The positioning gyroscope (1) is connected to the piston (3) and tap (4) by mortise and tenon joints; e. The selected tap (4) is a standard specification tap determined according to the specifications of the nut to be repaired. After the nut to be repaired is tapped by the tap (4), the damaged thread will be repaired. f. After the piston (3) and tap (4) are assembled into one piece by using a positioning gyroscope (1) in a mortise and tenon connection, the included angle between the central axes of the piston (3) and tap (4) is within the range of 0 to 2°.

2. The manufacturing method of the aircraft refueling control valve nut internal thread repair device according to claim 1, characterized in that: In step S4, the 18Ni300 mold steel powder needs to be vacuum dried at a temperature of 100-110°C for 3-6 hours, with a Hall flow rate of <25s / 50g.

3. A method for manufacturing a device for repairing the internal thread of an aircraft refueling control valve nut according to claim 2, characterized in that: In step S6a, when repairing the nut to be repaired, the nut to be repaired needs to be connected to the piston (3) by thread before assembling the internal thread repair device for the aircraft refueling control valve nut. When connecting, the end of the thread of the nut to be repaired that has not been punched for safety treatment faces the piston (3). After connection, the purpose of achieving the collinearity of the thread axis of the nut to be repaired and the piston (3) can be achieved.

4. An internal thread repair device using the manufacturing method of an aircraft refueling control valve nut internal thread repair device according to any one of claims 1 to 3, characterized in that: The positioning gyroscope (1) is mortised and tenoned with the piston (3) and the tap (4). The positioning gyroscope (1) is provided with a cylindrical gyroscope handle (c) with the same shape as the through hole (h) of the piston (3) and a gyroscope disk (a) with the same shape as the groove (i) of the piston (3). The positioning gyroscope (1) is gyroscope-shaped. The positioning gyroscope is designed with clearance fit between the piston fitting and the tap fitting according to their dimensions. 18Ni300 martensitic aging steel is selected and laser selection melting forming technology is used for rapid manufacturing. Finally, the internal thread repair device of the aircraft refueling control valve nut is assembled, which can reduce the variable range of the angle between the axis of the aircraft refueling control valve nut and the axis of the tap. The dimensions of the gyroscope handle (c) and the gyroscope disk (a) are designed so that the gyroscope handle (c) can penetrate the end face of the through hole (h) after the positioning gyroscope (1) is inserted into the piston (3). The positioning gyroscope (1) is hollowed out. When hollowing out, the minimum wall thickness of the positioning gyroscope (1) must be ≥2mm.

5. The internal thread repair device according to claim 4, characterized in that: The gap between the gyroscope disk (a) of the positioning gyroscope (1) and the cylindrical surface of the groove (i) of the piston (3) is between 0 and 0.1 mm.

6. The internal thread repair device according to claim 4, characterized in that: The gap between the gyroscope shank (c) of the positioning gyroscope (1) and the cylindrical surface of the through hole (h) of the piston (3) is between 0 and 0.1 mm.

7. The internal thread repair device according to claim 4, characterized in that: The positioning gyroscope (1) is provided with a gyroscope tip (b) with a cone-shaped protrusion, which is the same as the groove (f) of the tap (4).

8. The internal thread repair device according to claim 7, characterized in that: The gyroscope tip (b) is fitted with the groove (f) of the tap (4) in a clearance fit, and the fit size is between 0 and 0.1 mm.

Images