Method for repairing guide groove of piston rod of aircraft refueling exploring tube

Abstract

The invention discloses a method for repairing a guide groove of a piston rod of an aircraft refueling probe, which belongs to the field of guide groove repairing methods and comprises the following steps: step 1, designing and manufacturing an inner hole cladding head with the outer diameter of not more than 40mm, the laser focal length of 15-20mm and the powder coke of 15-20mm; 2, an inner groove of the oil receiving probe to be repaired is pretreated, namely a dry lubricant on the surface is removed through abrasive paper, and alcohol or acetone is used for cleaning after ultrasonic cleaning; 3, the high-strength stainless steel powder is subjected to vacuum drying at a certain temperature, the powder is taken out after being cooled, the powder is loaded into a powder bin of external powder feeding equipment, heating is started, and the temperature is set to be 50-80 DEG C; and 4, the oil receiving exploring tube is fixed to an external positioner. According to the method, the laser inner hole cladding repairing technology is adopted, the special inner hole cladding gun is assembled, the reachability of repairing the guide groove is good, the method has the advantages of low heat input, high repairing precision, small surface roughness and the like, the post-processing difficulty is greatly reduced, and the repairing success rate is high.

Description

Technical Field

[0001] The invention relates to the field of guide groove repairing methods, in particular to a guide groove repairing method for a piston rod of an aircraft oil receiving probe. Background Art

[0002] 0Cr15Ni5Cu2Ti is a precipitation hardening martensitic stainless steel with high strength and hardness, as well as good wear resistance. It is widely used in the aviation field. The aircraft refueling device is mainly made of 0Cr15Ni5Cu2Ti, which is responsible for refueling the receiving aircraft. Under the action of air load during operation, the internal guide groove is prone to eccentric wear. Repairing the eccentrically worn guide groove to restore the external dimensions and mechanical properties of the damaged part can reduce the cost of replacement.

[0003] The guide groove is located in the actuator, and the eccentric wear area is located on the narrow groove surface, so the repair operation space is extremely small. Conventional argon arc welding repair is difficult to reach the damaged location, the repair accuracy is low, and the heat input during welding is large, which will produce large internal stress, easily causing deformation and affecting assembly, resulting in difficulty in post-processing and low repair qualification rate.

[0004] Related patents: 202010379945.4 The production cost of cladding the inner wall of the hydraulic support cylinder is reduced by changing the wide spot laser cladding technology and the angled coaxial laser cladding technology. 201510785520.2 The corrosion resistance and wear resistance of the inner wall are improved by cladding alloy powder on the inner wall of the pipeline. 202111128310.8 The laser cladding method and composite device for the inner hole of the roller end sleeve of the rolling mill are disclosed. The above patents are mainly aimed at the repair of parts with relatively large inner diameters and simple structures. The repair of the inner wall guide grooves of parts with small inner diameters and complex structures has not been reported.

[0005] Therefore, those skilled in the art provide a method for repairing a piston rod guide groove of an aircraft oil receiving probe to solve the problems raised in the above-mentioned background technology. Summary of the invention

[0006] The purpose of the present invention is to provide a method for repairing the guide groove of the piston rod of an aircraft oil receiving probe, which adopts laser inner hole cladding repair technology and is equipped with a special inner hole cladding gun. The repair guide groove has good accessibility and has the advantages of low heat input, high repair accuracy, and small surface roughness. It greatly reduces the difficulty of post-processing and has a high repair success rate, so as to solve the problems raised in the above background technology.

[0007] To achieve the above object, the present invention provides the following technical solutions:

[0008] A method for repairing a piston rod guide groove of an aircraft oil receiving probe comprises the following steps:

[0009] Step 1: Design and manufacture an inner hole cladding head, wherein the outer diameter of the inner hole cladding head is not greater than 40 mm, the laser focal length is 15-20 mm, and the powder focal length is 15-20 mm;

[0010] Step 2: Pre-treat the inner groove of the oil receiving probe to be repaired, that is, use sandpaper to remove the surface dry lubricant, and then clean it with alcohol or acetone after ultrasonic cleaning;

[0011] Step 3: vacuum dry the high-strength stainless steel powder at a certain temperature, take it out after the powder cools down, put the powder into the powder bin of the external powder feeding equipment, turn on the heating, and set the temperature to 50-80℃;

[0012] Step 4: Fix the oil probe to the external positioner. To prevent scratches, wrap the clamping position with a heat-resistant plastic sheet or thick paper for protection;

[0013] Step 5: Position the laser at the damaged position, that is, insert the inner hole cladding head into the oil receiving probe, and then position the laser at the damaged position through the inner hole cladding head;

[0014] Step 6: Start repairing. The repairing process parameters are: laser power 600W~1000W, overlap rate 40%~50%, scanning speed 8~12mm / s, spot diameter 1.2~1.5mm;

[0015] Step 7: Perform rough EDM machining on the oil receiving probe tube, and then polish it to make the size and surface condition of the oil receiving probe tube meet the process requirements;

[0016] Step 8: Evaluate the performance of the repaired oil probe.

[0017] As a further solution of the present invention: in the step one, the inner hole cladding head includes a shell, an inner cylinder is embedded in the middle position of the shell, and a focusing mirror is embedded at one end of the inner cylinder, a reflecting mirror is embedded on one side of the inner cylinder, and a light outlet is provided on the inner wall of the shell below the reflecting mirror, a powder guide tube is embedded in the shell on the side of the light outlet, and a powder inlet connected to the top opening of the powder guide tube is provided on the outer side of the shell, and the powder inlet is connected to a powder bin of an external powder feeding device.

[0018] As a further solution of the present invention: in the step three, the composition (wt%) of the high-strength stainless steel powder is: C: 0.19-0.21, Cr: 2.8-3.0, Mn: ≤0.01, Si: ≤0.01, Ni: 10-12, Mo: 1.1-1.3, Co: 13-14, Fe: balance.

[0019] As a further solution of the present invention: the stainless steel powder is prepared by electrode induction atomization method.

[0020] As a further solution of the present invention: in step five, after the laser is positioned at the damaged position, a heat-resistant plastic bag is used to wrap the oil receiving probe and the front 20 cm portion of the inner hole cladding head and the bag is tied with a cable tie.

[0021] As a further solution of the present invention: in step six, the laser path is parallel to the guide groove, and the cladding is paused for one minute until the temperature is lower than 40°C.

[0022] As a further solution of the present invention: in step six, in order to prevent the temperature from rising beyond 80°C during the repair process, dry ice is used for cooling, and infrared temperature detection is used. When the guide groove temperature exceeds 80°C, cladding is stopped, and cladding is resumed after cooling to 40°C, wherein the dry ice is placed outside the oil receiving probe.

[0023] As a further solution of the present invention: in step seven, the electrospark machining process is a pulse current of 4 to 6A, a period of 200 to 300ms, and a duty cycle of 0.4 to 0.5.

[0024] Compared with the prior art, the present invention has the following beneficial effects:

[0025] The invention aims at the problems of poor accessibility, low surface precision, large deformation, low repair qualification rate, etc. of the current aircraft oil probe piston rod guide groove repair, and creatively proposes to repair the aircraft oil probe piston rod guide groove by laser inner hole cladding process, and finally obtains a non-deformed, high-precision repaired part. The conventional repair methods of aircraft titanium alloy rocker arms have solved the shortcomings of low surface precision, large deformation, low repair qualification rate, etc. Among them, 30% of the repair tensile strength reaches 1356±20MPa, and the hardness HRC 53±2, which increases its wear resistance and repair qualification rate, effectively prolongs the service life of parts, saves rework costs and time, and economic losses caused by scrapped parts.

[0026] The tensile strength of conventional argon arc welding at 30% repair depth is only 1256±30MPa, the elongation is 6%, and the hardness HRC is 53±2. This method can significantly improve the repair service performance.

[0027] Compared with conventional argon arc welding, it not only has excellent mechanical properties, but also the surface of the inner hole laser cladding is smooth and easy to process, and the repair qualification rate is increased by 70%. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 It is a flow chart of a method for repairing a piston rod guide groove of an aircraft oil receiving probe;

[0029] Figure 2 It is a structural schematic diagram of an inner hole cladding head in a method for repairing a piston rod guide groove of an aircraft oil receiving probe;

[0030] Figure 3It is an internal view of an inner hole cladding head in a method for repairing a piston rod guide groove of an aircraft oil receiving probe;

[0031] Figure 4 This is a metallographic diagram of the interface structure after repair in a method for repairing the piston rod guide groove of an aircraft oil receiving probe.

[0032] In the figure: 101, shell; 102, inner cylinder; 103, focusing mirror; 104, reflecting mirror; 105, light outlet; 106, powder guide tube; 107, powder inlet. DETAILED DESCRIPTION

[0033] 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.

[0034] As mentioned in the background technology of this application, research has found that the existing guide groove is located in the actuator cylinder, and the eccentric wear area is located on the narrow groove surface, so the repair operation space is extremely small. Conventional argon arc welding repair is difficult to reach the damaged location, the repair accuracy is low, and the heat input during welding is large, which will produce large internal stress, easily causing deformation and affecting assembly, resulting in great difficulty in post-processing and a low repair qualification rate. There are certain defects.

[0035] In order to solve the above-mentioned defects, the present application discloses a method for repairing the guide groove of the piston rod of an aircraft oil receiving probe, which adopts laser inner hole cladding repair technology and is equipped with a special inner hole cladding gun. The repaired guide groove has good accessibility and has the advantages of low heat input, high repair accuracy, and small surface roughness, which greatly reduces the difficulty of post-processing and has a high repair success rate.

[0036] The following will describe in detail how the solution of the present application solves the above technical problems in conjunction with the accompanying drawings.

[0037] See also Figure 1In an embodiment of the present invention, a method for repairing a piston rod guide groove of an aircraft oil receiving probe comprises the following steps: Step 1: designing and manufacturing an inner hole cladding head, wherein the outer diameter of the inner hole cladding head is not greater than 40 mm, the laser focal length is 15 to 20 mm, and the powder coke is 15 to 20 mm; Step 2: pre-treating the inner groove of the oil receiving probe to be repaired, i.e., removing the surface dry lubricant with sandpaper, and cleaning with alcohol or acetone after ultrasonic cleaning; Step 3: vacuum drying high-strength stainless steel powder at a certain temperature, taking out the powder after cooling, and loading the powder into the powder bin of an external powder feeding device, turning on the heating, and setting the temperature to 50 to 80 ° C; Step 4: cladding the oil receiving probe Fixed to the external positioner, to prevent scratches, the clamping position is wrapped with heat-resistant plastic sheets or thick paper for protection; Step 5: Position the laser to the damaged position, that is, insert the inner hole cladding head into the oil-receiving probe, and then position the laser to the damaged position through the inner hole cladding head; Step 6: Start repair, the repair process parameters are: laser power 600W~1000W, overlap rate 40%~50%, scanning speed 8~12mm / s, spot diameter 1.2~1.5mm; Step 7: Perform electrospark rough machining on the oil-receiving probe, and then polish it so that the size and surface state of the oil-receiving probe meet the process requirements; Step 8: Evaluate the performance of the repaired oil-receiving probe. This application adopts laser inner hole cladding repair technology, assembles a special inner hole cladding gun, has good accessibility to the repair guide groove, and has the advantages of low heat input, high repair accuracy, and small surface roughness, which greatly reduces the difficulty of post-processing and has a high repair success rate.

[0038] In this embodiment, if Figure 2 and Figure 3 As shown, in step one, the inner hole cladding head includes a shell 101, an inner cylinder 102 is embedded in the middle position of the shell 101, and a focusing mirror 103 is embedded at one end of the inner cylinder 102, a reflector 104 is embedded on one side of the inner cylinder 102, and a light outlet 105 is provided on the inner wall of the shell 101 below the reflector 104, a powder guide tube 106 is embedded in the shell 101 on the side of the light outlet 105, and a powder inlet 107 connected to the top opening of the powder guide tube 106 is provided on the outer side of the shell 101, and the powder inlet 107 is connected to the powder bin of the external powder feeding equipment. The laser enters the inner cylinder 102 from one end of the shell 101, and is focused by the focusing mirror 103 and irradiated onto the reflector 104. The reflector 104 reflects the focused laser light, and the reflected laser light irradiates the guide groove to be repaired of the oil receiving probe along the light outlet 105. At the same time, the external powder feeding equipment runs to feed the high-strength stainless steel powder in the powder bin into the powder guide tube 106 through the powder inlet 107. The powder guide tube 106 then guides the high-strength stainless steel powder to the guide groove to be repaired below. The laser cooperates with the high-strength stainless steel powder to complete the repair of the guide groove.

[0039] In this embodiment, in step 3, the composition of the high-strength stainless steel powder (wt%) is: C: 0.19-0.21, Cr: 2.8-3.0, Mn: ≤0.01, Si: ≤0.01, Ni: 10-12, Mo: 1.1-1.3, Co: 13-14, Fe: balance. The stainless steel powder with this ratio has excellent physical properties, excellent corrosion resistance and durability, good floating and film-forming properties.

[0040] In this embodiment, stainless steel powder is prepared by electrode induction gas atomization. The electrode induction gas atomization powder making process is to regionally refine the prefabricated stainless steel raw materials under appropriate vacuum conditions and protective gas conditions. The metal liquid flows vertically downward through the nozzle continuously, and the high-pressure airflow through the nozzle atomizes and breaks the metal liquid into a large number of fine droplets. The droplets solidify into particles during the flight process, thereby producing stainless steel powder.

[0041] In this embodiment, in step 5, after the laser is positioned at the damaged position, a heat-resistant plastic bag is used to wrap the oil receiving probe and the front 20 cm portion of the inner hole cladding head and tie the bag with a cable tie. This setting is to protect these key components from high temperature or other potential damages generated by the laser.

[0042] In this embodiment, in step six, the laser path is parallel to the guide groove (this path planning ensures that the laser energy can act on the guide groove surface evenly and continuously, thereby achieving high-quality cladding repair), and the cladding process is paused for one minute until the temperature is lower than 40°C (in the laser cladding process, after each cladding process, a pause is required for temperature control and material cooling. This period of time allows the oil probe and the cladding layer to cool sufficiently to reduce thermal stress and prevent material deformation). This setting avoids damage to parts caused by high temperatures caused by long-term repair.

[0043] In this embodiment, in step six, in order to prevent the temperature from rising above 80°C during the repair process, dry ice is used for cooling, and infrared temperature detection is used. When the guide groove temperature exceeds 80°C, the cladding is stopped, and the cladding is resumed after cooling to 40°C, wherein the dry ice is placed on the outside of the oil receiving probe. During the laser repair process, the high energy generated by the laser will cause the temperature of the oil receiving probe and its guide groove to rise sharply. Excessive temperature may cause material deformation, thermal stress, and even cracks, thereby affecting the repair effect and performance. Therefore, temperature control is a key link to ensure the quality of the repair. In order to effectively control the temperature, dry ice is placed on the outside of the oil receiving probe. Since dry ice has an extremely low temperature (-78.5°C), it can quickly absorb the heat of the oil receiving probe and its surrounding environment, thereby reducing the temperature. Dry ice cooling can significantly slow down the temperature rise rate of the oil receiving probe during the laser repair process, keeping the temperature within a controllable range. At the same time, the cooling effect of dry ice can also reduce thermal stress and reduce the risk of material deformation.

[0044] In this embodiment, in step seven, the EDM process is a pulse current of 4-6A, a period of 200-300ms, and a duty cycle of 0.4-0.5. EDM is based on the electro-erosion phenomenon during pulsed spark discharge between the tool electrode and the workpiece (positive and negative electrodes). During the discharge process, the metal on the surface of the electrode and the workpiece is melted, vaporized, and thrown out by high temperature, thereby achieving material removal.

[0045] In this embodiment, in step eight, the repaired oil receiving probe interface structure is as follows: Figure 4 As shown, the structure is dense and has no defects. Repair strength evaluation: The tensile strength of the inner hole laser cladding 30% repair depth reaches 1356±20MPa, the elongation is 16%, and the hardness HRC 53±2.

[0046] The present invention aims at the problems that the current aircraft oil probe piston rod guide groove has poor accessibility, low surface accuracy, large deformation, low repair qualification rate, etc., and creatively proposes to repair the aircraft oil probe piston rod guide groove with a laser inner hole cladding process, and finally obtains a deformation-free, high-precision repaired part. The conventional repair methods of aircraft titanium alloy rocker arms have solved the shortcomings of low surface accuracy, large deformation, and low repair qualification rate. Among them, the 30% repair tensile strength reaches 1356±20MPa, and the hardness HRC 53±2, which increases its wear resistance and repair qualification rate, effectively prolongs the service life of the parts, saves rework costs and time, and the economic losses caused by the scrapping of parts. The conventional argon arc welding 30% repair depth tensile strength is only 1256±30MPa, the elongation is 6%, and the hardness HRC 53±2. This method can significantly improve the repair service performance. Compared with conventional argon arc welding, it not only has excellent mechanical properties, but also the inner hole laser cladding surface is flat and easy to process, and the repair qualification rate is increased by 70%.

[0047] Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include these modifications and variations.

[0048] What is described above is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A method for repairing a piston rod guide groove of an aircraft oil receiving probe, characterized in that: The following steps are involved: Step 1: Design and manufacture an inner hole cladding head, wherein the outer diameter of the inner hole cladding head is not greater than 40 mm, the laser focal length is 15-20 mm, and the powder focal length is 15-20 mm; Step 2: Pre-treat the inner groove of the oil receiving probe to be repaired, that is, use sandpaper to remove the surface dry lubricant, and then clean it with alcohol or acetone after ultrasonic cleaning; Step 3: vacuum dry the high-strength stainless steel powder at a certain temperature, take it out after the powder cools down, put the powder into the powder bin of the external powder feeding equipment, turn on the heating, and set the temperature to 50-80℃; Step 4: Fix the oil probe to the external positioner. To prevent scratches, wrap the clamping position with a heat-resistant plastic sheet or thick paper for protection; Step 5: Position the laser at the damaged position, that is, insert the inner hole cladding head into the oil receiving probe, and then position the laser at the damaged position through the inner hole cladding head; Step 6: Start repairing. The repairing process parameters are: laser power 600W~1000W, overlap rate 40%~50%, scanning speed 8~12mm / s, spot diameter 1.2~1.5mm; Step 7: Perform rough EDM machining on the oil receiving probe tube, and then polish it to make the size and surface condition of the oil receiving probe tube meet the process requirements; Step 8: Evaluate the performance of the repaired oil probe.

2. A method for repairing a piston rod guide groove of an aircraft oil receiving probe according to claim 1, characterized in that: In the step 1, the inner hole cladding head comprises a shell (101), an inner cylinder (102) is embedded in the middle position of the shell (101), and a focusing mirror (103) is embedded at one end of the inner cylinder (102), a reflecting mirror (104) is embedded on one side of the inner cylinder (102), and a light outlet (105) is provided on the inner wall of the shell (101) below the reflecting mirror (104), a powder guide tube (106) is embedded in the shell (101) on one side of the light outlet (105), and a powder inlet (107) connected to the top opening of the powder guide tube (106) is provided on the outer side of the shell (101), and the powder inlet (107) is connected to a powder bin of an external powder feeding device.

3. A method for repairing a piston rod guide groove of an aircraft oil receiving probe according to claim 2, characterized in that: In the step three, the composition (wt%) of the high-strength stainless steel powder is: C: 0.19-0.21, Cr: 2.8-3.0, Mn: ≤0.01, Si: ≤0.01, Ni: 10-12, Mo: 1.1-1.3, Co: 13-14, Fe: balance.

4. A method for repairing a piston rod guide groove of an aircraft oil receiving probe according to claim 3, characterized in that: The stainless steel powder is prepared by an electrode induction atomization method.

5. A method for repairing a piston rod guide groove of an aircraft oil receiving probe according to claim 4, characterized in that: In step 5, after the laser is positioned at the damaged position, a heat-resistant plastic bag is used to wrap the oil receiving probe and the front 20 cm portion of the inner hole cladding head and the bag is tied with a cable tie.

6. A method for repairing a piston rod guide groove of an aircraft oil receiving probe according to claim 5, characterized in that: In step six, the laser path is parallel to the guide groove, and the cladding is paused for one minute until the temperature is lower than 40°C.

7. A method for repairing a piston rod guide groove of an aircraft oil receiving probe according to claim 6, characterized in that: In step six, in order to prevent the temperature from rising beyond 80°C during the repair process, dry ice is used for cooling, and infrared temperature detection is used. When the guide groove temperature exceeds 80°C, cladding is stopped, and cladding is resumed after cooling to 40°C. The dry ice is placed outside the oil receiving probe.

8. A method for repairing a piston rod guide groove of an aircraft oil receiving probe according to claim 7, characterized in that: In step seven, the EDM process has a pulse current of 4-6A, a period of 200-300ms, and a duty cycle of 0.4-0.5.

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