Magnetic particle grinding and finishing machining method for internal flow channel of additive manufacturing fuel oil spray rod

Abstract

The invention discloses a magnetic particle grinding and finishing processing method for an inner runner of an additive manufacturing fuel spray rod. The method comprises the following steps: assembling processing equipment; a nozzle opening of the fuel oil spray rod is blocked; filling a magnetic grinding particle medium and an aqueous grinding liquid; blocking a main oil inlet of the fuel oil spray rod; mounting the fuel spray rod to processing equipment; the magnetic grinding machine is started, and the magnetic grinding particle medium is driven to move disorderly to grind and finish the inner flow channel of the fuel oil spray rod under the magnetic force action of the rotating magnetic field; the rotation angle of the fuel spray rod is periodically adjusted in the magnetic grinding process; closing the magnetic grinding machine after the magnetic grinding time is ended; dismounting the fuel spray rod, dismounting the plug, and pouring out the magnetic grinding particle medium and the aqueous grinding fluid; flushing the fuel spray rod by using high-pressure water; the fuel oil spraying rod is dried; and demagnetizing the fuel spray rod. According to the method, the surface polishing problem of the inner flow channel of the integrated additive manufacturing fuel spray rod is solved, the surface quality of the inner flow channel can be greatly improved after polishing, and the use requirement of the fuel spray rod in a spacecraft propulsion system is met.

Description

Technical Field

[0001] The invention belongs to the technical field of surface finishing of parts, and in particular relates to a magnetic particle grinding and finishing method for an inner flow channel of an additively manufactured fuel spray rod. Background Art

[0002] In the aerospace field, fuel spray rods play a vital role. The main function of the fuel spray rods is to accurately spray fuel into the cylinders in the engine to ensure that the mixing and combustion of fuel and oxidizer can achieve the best thrust output. The propulsion system of the spacecraft has much higher requirements for fuel injection than engines in other fields, because the spacecraft must operate stably under extreme conditions, and the propulsion system not only needs to face extreme temperature and pressure changes, but also needs to work in a microgravity environment. This requires the fuel spray rods to have extremely high stability and durability in both structure and function. It must be able to withstand extreme working conditions, such as strong vibrations and drastic temperature changes, while maintaining the accuracy of the injection to ensure that the engine can operate stably and reliably.

[0003] However, the standards for the surface finish of the inner flow channel of the fuel nozzle rod in other fields can no longer meet the requirements for use in spacecraft propulsion systems. Since the fuel nozzle rod has achieved integrated additive manufacturing, traditional finishing methods are difficult to apply to the polishing of the inner flow channel surface of the fuel nozzle rod, and the surface finish of the inner flow channel of the fuel nozzle rod after polishing using traditional finishing methods cannot meet the requirements for use in spacecraft propulsion systems. Summary of the invention

[0004] In view of the problems existing in the prior art, the present invention provides a method for magnetic particle grinding and finishing of the inner flow channel of an additively manufactured fuel spray rod, which solves the problem of surface polishing of the inner flow channel of an integrated additively manufactured fuel spray rod, especially the difficult-to-polish parts at the intersection of the main channel and the nozzle. After polishing, the surface quality can be greatly improved. Under the action of strong vibration and drastic temperature changes, the fatigue resistance of the fuel spray rod can be effectively improved, thereby meeting its use requirements in spacecraft propulsion systems.

[0005] In order to achieve the above-mentioned purpose, the present invention adopts the following technical scheme: a method for magnetic particle grinding and finishing of the inner flow channel of a fuel injection rod in additive manufacturing, comprising the following steps:

[0006] Step 1: Prepare a magnetic grinder, a robotic arm and a three-jaw chuck, and process a spray bar fixing seat. The magnetic grinder and the robotic arm are arranged in parallel;

[0007] Step 2: Install the three-jaw chuck as the end effector on the robot arm, and then clamp the spray boom fixing base to the three-jaw chuck;

[0008] Step 3: Block all nozzles of the fuel spray rod to be processed, leaving only one main fuel inlet unblocked;

[0009] Step 4: First, load the magnetic abrasive particle medium into the fuel spray rod through the main oil inlet, and then pour the water-based abrasive liquid into the fuel spray rod through the main oil inlet until the water-based abrasive liquid overflows from the main oil inlet, and finally seal the main oil inlet;

[0010] Step 5: Fix the fuel spray rod filled with magnetic abrasive particle media and aqueous abrasive liquid to the spray rod fixing seat;

[0011] Step 6: Move the fuel spray rod to the top of the magnetic grinder's disk by the mechanical arm, so that the fuel spray rod is parallel to the disk;

[0012] Step 7: Start the magnetic grinding machine, set the magnetic grinding time, generate a rotating magnetic field through the magnetic disk, and place the fuel spray rod in the rotating magnetic field. Under the magnetic force of the rotating magnetic field and the combined force of inertia, grinding fluid buoyancy and mutual collision between media, the magnetic grinding particle media will move disorderly inside the fuel spray rod, and then the flow channel inside the fuel spray rod will be ground and smoothed by the disorderly moving magnetic grinding particle media;

[0013] Step 8: During the magnetic grinding process, the central axis of the three-jaw chuck is used as the rotation center line, and the mechanical arm periodically adjusts the rotation angle of the fuel spray rod so that the disorderly moving magnetic grinding particle medium is fully in contact with all parts of the flow channel in the fuel spray rod;

[0014] Step 9: When the magnetic grinding time is over, turn off the magnetic grinder, first lift the fuel spray rod from above the magnetic grinder's disk, and then remove the fuel spray rod from the spray rod fixing seat;

[0015] Step 10: Remove the plugs at the main fuel inlet and all nozzles of the fuel spray rod, then pour out all the magnetic abrasive particle media and aqueous abrasive liquid in the fuel spray rod, and recycle the poured out magnetic abrasive particle media for reuse;

[0016] Step 11: Introduce high-pressure water from the main oil inlet of the fuel spray rod to flush the inner flow channel of the fuel spray rod, and clean all the remaining grinding chips, magnetic abrasive particle media and aqueous abrasive liquid;

[0017] Step 12: Place the cleaned fuel spray rod into a drying box for drying to remove residual moisture on the surface of the fuel spray rod;

[0018] Step 13: Send the dried fuel spray rod into the demagnetization machine to complete the demagnetization of the fuel spray rod.

[0019] Beneficial effects of the present invention:

[0020] The magnetic particle grinding and finishing processing method for the inner flow channel of the additively manufactured fuel spray rod of the present invention solves the problem of surface polishing of the inner flow channel of the integrated additively manufactured fuel spray rod, especially the difficult-to-polish parts at the intersection of the main flow channel and the nozzle. After polishing, the surface quality can be greatly improved. Under the action of strong vibration and drastic temperature changes, the fatigue resistance of the fuel spray rod can be effectively improved, thereby meeting its use requirements in the spacecraft propulsion system. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a schematic diagram of the structure of the assembly of the mechanical arm, the three-jaw chuck, the spray rod fixing seat and the fuel spray rod;

[0022] Figure 2 This is a microscopic image of the first measuring point on the inner flow channel surface of the fuel injection rod before grinding;

[0023] Figure 3 This is a microscopic image of the first measuring point on the inner flow channel surface of the fuel injection rod after grinding;

[0024] Figure 4 This is a microscopic image of the second measuring point on the inner flow channel surface of the fuel injection rod before grinding;

[0025] Figure 5 This is a microscopic image of the second measuring point on the inner flow channel surface of the fuel injection rod after grinding;

[0026] In the figure, 1 is a mechanical arm, 2 is a three-jaw chuck, 3 is a spray rod fixing seat, and 4 is a fuel spray rod. DETAILED DESCRIPTION

[0027] The present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0028] A method for magnetic particle grinding and finishing of an inner flow channel of an additively manufactured fuel spray rod comprises the following steps:

[0029] Step 1: Prepare a magnetic grinding machine, a robotic arm 1 and a three-jaw chuck 2, and process a spray bar fixing seat 3. The magnetic grinding machine and the robotic arm 1 are arranged in parallel;

[0030] Step 2: Install the three-jaw chuck 2 as the end effector on the robot arm 1, and then clamp the spray rod fixing base 3 on the three-jaw chuck 2;

[0031] Step 3: Block all nozzle openings of the fuel spray rod 4 to be processed, leaving only one main fuel inlet unblocked;

[0032] Step 4: first, fill the magnetic abrasive particle medium into the fuel spray rod 4 through the main oil inlet, and then pour the aqueous abrasive liquid into the fuel spray rod 4 through the main oil inlet until the aqueous abrasive liquid overflows from the main oil inlet, and finally block the main oil inlet; in this embodiment, the filling amount of the magnetic abrasive particle medium is 50g to 100g, and the particle size of the magnetic abrasive particle medium is 0.5μm;

[0033] Step 5: Fix the fuel spray rod 4 filled with magnetic abrasive particles and aqueous abrasive liquid to the spray rod fixing base 3, as shown in FIG. Figure 1 As shown;

[0034] Step 6: Move the fuel spray rod 4 to above the magnetic disk of the magnetic grinder through the mechanical arm 1, so that the fuel spray rod 4 is parallel to the magnetic disk;

[0035] Step 7: Start the magnetic grinding machine, set the magnetic grinding time, generate a rotating magnetic field through the magnetic disk, and place the fuel spray rod 4 in the rotating magnetic field. Under the magnetic force of the rotating magnetic field and the combined force of inertia, buoyancy of the grinding fluid and mutual collision force between the media, the magnetic grinding particle media will make disorderly movement inside the fuel spray rod 4, and then the flow channel inside the fuel spray rod will be ground and smoothed by the disorderly moving magnetic grinding particle media;

[0036] Step 8: During the magnetic grinding process, the central axis of the three-jaw chuck 2 is used as the rotation center line, and the mechanical arm 1 periodically adjusts the rotation angle of the fuel spray rod 4 so that the disorderly moving magnetic grinding particle medium is fully in contact with all parts of the flow channel in the fuel spray rod 4;

[0037] Step 9: After the magnetic grinding time is over, turn off the magnetic grinder, first lift the fuel spray rod 4 from above the magnetic disk of the magnetic grinder, and then remove the fuel spray rod 4 from the spray rod fixing seat 3;

[0038] Step 10: Remove the plugging at the main oil inlet and all nozzle openings of the fuel spray rod 4, then pour out all the magnetic abrasive particle media and aqueous abrasive liquid in the fuel spray rod 4, and recycle the magnetic abrasive particle media for reuse;

[0039] Step 11: Introduce high-pressure water from the main oil inlet of the fuel spray rod 4 to flush the inner flow channel of the fuel spray rod 4, and clean all the remaining grinding chips, magnetic grinding particle media and aqueous grinding liquid;

[0040] Step 12: Send the cleaned fuel spray rod 4 into a drying box for drying to remove residual moisture on the surface of the fuel spray rod 4;

[0041] Step 13: Send the dried fuel spray rod 4 into a demagnetizing machine to complete the demagnetization of the fuel spray rod 4.

[0042] In order to verify the effectiveness of the magnetic particle grinding finishing method for the inner flow channel of the fuel injection rod of the additive manufacturing of the present invention, the surface of the inner flow channel of the fuel injection rod before and after grinding was experimentally measured and compared, and there were two measurement points in total. Among them, the microscopic appearance of the first measurement point before grinding is as follows Figure 2 As shown, the first measurement point is located at the microscopic surface after grinding. Figure 3 As shown in the figure, the second measurement point is the microscopic appearance before grinding. Figure 4 As shown in the figure, the second measurement point is located at the microscopic surface after grinding. Figure 5 As shown. It can be clearly seen from the microscopic morphology that the surface particles of the two measuring points have been significantly removed after grinding. In addition, the roughness of the first measuring point was measured before and after grinding. The roughness measurement value before grinding was Ra6.7453μm, and the roughness measurement value after grinding was Ra2.1932μm. From the roughness measurement results, the surface quality after grinding has been significantly improved.

[0043] The solutions in the embodiments are not intended to limit the protection scope of the present invention. All equivalent implementations or changes that do not deviate from the present invention are included in the protection scope of the present invention.

Claims

1. A method for magnetic particle grinding and finishing of the inner flow channel of a fuel spray rod in additive manufacturing, characterized in that: The steps include: Step 1: Prepare a magnetic grinder, a robotic arm and a three-jaw chuck, and process a spray bar fixing seat. The magnetic grinder and the robotic arm are arranged in parallel; Step 2: Install the three-jaw chuck as the end effector on the robot arm, and then clamp the spray boom fixing base to the three-jaw chuck; Step 3: Block all nozzles of the fuel spray rod to be processed, leaving only one main fuel inlet unblocked; Step 4: First, load the magnetic abrasive particle medium into the fuel spray rod through the main oil inlet, and then pour the water-based abrasive liquid into the fuel spray rod through the main oil inlet until the water-based abrasive liquid overflows from the main oil inlet, and finally seal the main oil inlet; Step 5: Fix the fuel spray rod filled with magnetic abrasive particle media and aqueous abrasive liquid to the spray rod fixing seat; Step 6: Move the fuel spray rod to the top of the magnetic grinder's disk by the robotic arm, so that the fuel spray rod and the disk remain parallel; Step 7: Start the magnetic grinding machine, set the magnetic grinding time, generate a rotating magnetic field through the magnetic disk, and place the fuel spray rod in the rotating magnetic field. Under the magnetic force of the rotating magnetic field and the combined force of inertia, grinding fluid buoyancy and mutual collision between media, the magnetic grinding particle media will move disorderly inside the fuel spray rod, and then the flow channel inside the fuel spray rod will be ground and smoothed by the disorderly moving magnetic grinding particle media; Step 8: During the magnetic grinding process, the central axis of the three-jaw chuck is used as the rotation center line, and the mechanical arm periodically adjusts the rotation angle of the fuel spray rod so that the disorderly moving magnetic grinding particle medium is fully in contact with all parts of the flow channel in the fuel spray rod; Step 9: When the magnetic grinding time is over, turn off the magnetic grinder, first lift the fuel spray rod from above the magnetic grinder's disk, and then remove the fuel spray rod from the spray rod fixing seat; Step 10: Remove the plugs at the main fuel inlet and all nozzles of the fuel spray rod, then pour out all the magnetic abrasive particle media and aqueous abrasive liquid in the fuel spray rod, and recycle the poured out magnetic abrasive particle media for reuse; Step 11: Introduce high-pressure water from the main oil inlet of the fuel spray rod to flush the inner flow channel of the fuel spray rod, and clean all the remaining grinding chips, magnetic abrasive particle media and aqueous abrasive liquid; Step 12: Place the cleaned fuel spray rod into a drying box for drying to remove residual moisture on the surface of the fuel spray rod; Step 13: Send the dried fuel spray rod into the demagnetization machine to complete the demagnetization of the fuel spray rod.

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