Low-pressure liquid-gas self-tightening device and metal-based carbon fiber reinforced memory barrel process

Abstract

The invention relates to a low-pressure liquid-gas self-tightening device and a metal-based carbon fiber reinforced memory barrel process, and belongs to the technical field of reinforced manufacturing of precise metal pipes. According to the self-tightening device, a double-path pressure supply system is adopted, through the synergistic effect of the tungsten alloy self-tightening blade module and the film-shaped air bag, the pressure of the kilomegapascals required by traditional hydraulic self-tightening is reduced to 1.2 * 10 < 6 > Pa, the equipment cost is reduced by 92%, the energy consumption is reduced by 95%, and high-precision strengthening (the precision is + / -0.02 mm, and the rejection rate is smaller than 3%) of the pipe with the caliber of 5-57 mm is achieved. According to the metal-based carbon fiber reinforced memory barrel process, through gradient compounding of a carbon fiber framework and a copper-titanium-nickel memory alloy layer and combination of directional magnetization, thermal self-tightening and laser etching technologies, the fatigue life of a barrel is prolonged to 7.62 * 51mm, the NATO caliber is 20000 or above, the weight is reduced by 32%, the pollution index is reduced to the CTF-2 level from the CTF-7 level, and the barrel precision reaches 800 m / MOA. The method breaks through the technical bottlenecks of small-caliber pipe reinforcement and environment-friendly manufacturing, is suitable for the fields of high-end artillery, precise instruments and the like, and has remarkable economic benefits and environment-friendly advantages.

Description

Technical Field

[0001] The present invention relates to the technical field of precision metal pipe reinforcement manufacturing, specifically to a low-pressure liquid-gas self-tightening device and a metal-based carbon fiber reinforced memory barrel process. Background Art

[0002] Traditional hydraulic self-tightening requires maintaining high pressure at the gigapascal level (>1GPa), with equipment costs exceeding 2 million yuan and energy consumption reaching 5.8kW·h / m;

[0003] The scrap rate of the stamping self-tightening process is greater than 15%, and it is not suitable for pipes with a diameter of less than 30mm;

[0004] The fatigue life of alloy barrels currently in service is generally less than 2,000 rounds (7.62*51mm NATO caliber standard test);

[0005] The pollution index of the chrome plating process reaches CTF-7 level (EU environmental protection standard).

[0006] In order to solve the problems of the prior art, the present invention provides a low-pressure liquid-gas self-tightening device and a metal-based carbon fiber reinforced memory barrel process. Summary of the Invention

[0007] In order to solve the problems of the prior art, the present invention provides a low-pressure liquid-gas self-tightening device and a metal-based carbon fiber reinforced memory barrel process.

[0008] In order to solve the above technical problems, the present invention is achieved through the following technical solutions: First, a low-pressure liquid-gas self-tightening device and a metal-based carbon fiber reinforced memory barrel process, including:

[0009] Axially arranged tungsten alloy self-tightening leaf modules are made of high-strength tungsten alloy and contain a radially expandable membrane-like airbag structure;

[0010] Split hydraulic drive unit adopts thread self-locking mechanism;

[0011] Dual-circuit pressure supply system consisting of oil transmission channel and gas transmission channel;

[0012] The number of self-tightening leaf modules can be increased or decreased according to processing requirements.

[0013] In this application, the core component structure description

[0014] The self-tightening head module consists of 6-8 groups of high-strength tungsten alloy self-tightening blades arranged in a ring array. Connection relationship:

[0015] The inner side of the self-tightening leaf is bonded and fixed to the membranous air bag.

[0016] The outer surface of the self-tightening blade is plated with a 0.1mm hard alloy layer.

[0017] The distance between adjacent self-tightening leaves is kept at an adjustable gap of 0.5-1mm.

[0018] Position relationship:

[0019] Three groups of self-tightening rings are evenly distributed along the axial direction (each group contains 6-8 self-tightening leaves). The initial inner diameter of the self-tightening leaves is 5%-8% smaller than the inner diameter of the tube embryo.

[0020] Hydraulic drive unit

[0021] composition:

[0022] Oil transfer channel: Φ6mm high-pressure resistant stainless steel pipe.

[0023] Gas transmission channel: Φ8mm rubber hose.

[0024] Mechanical thread self-locking mechanism: M20×2.5 trapezoidal thread.

[0025] Connection relationship:

[0026] The end of the oil delivery channel is connected to the oil inlet of the membrane air bag.

[0027] The air delivery channel is directly connected to the airbag chamber.

[0028] The self-locking mechanism is opened and closed by controlling the oil pressure through the handwheel.

[0029] Pressure supply system

[0030] composition:

[0031] Low-pressure oil pump: plunger type, maximum output pressure 2MPa

[0032] Air pressure maintaining device: Compressed air tank with safety valve.

[0033] Connection relationship:

[0034] The oil pump outlet is connected to three sets of self-tightening rings through a three-way valve.

[0035] The air pressure maintaining device is connected to the air supply channel through a quick-change connector.

[0036] Workflow structure linkage

[0037] Initial state:

[0038] The self-tightening leaves are in a contracted state, and the outer diameter of the entire device is ≤ 95% of the inner diameter of the tube embryo.

[0039] The membrane airbag is not inflated and its thickness remains at 0.8 mm.

[0040] Hydraulic drive stage:

[0041] The oil pump injects hydraulic oil → the airbag expands → pushes the self-tightening blades to expand radially

[0042] The self-locking mechanism screws in and locks the pressure.

[0043] Air pressure holding stage:

[0044] Compressed air (0.8-1.2 MPa) is passed through the air delivery channel (4) to maintain the shape of the airbag (2).

[0045] The hydraulic system can be disconnected and only the air circuit continues to work.

[0046] In a specific embodiment of the first aspect, when the membranous airbag is filled with a compressive medium, the outward protrusion of the self-tightening leaflet can undergo plastic deformation;

[0047] The working pressure of the hydraulic drive unit is 1.2×10 6 Pa;

[0048] Suitable for pipes with diameters from 5mm to 57mm.

[0049] In a specific embodiment of the first aspect, the tungsten alloy composition of the self-tightening leaf module is W-8Ni-3Fe, the Vickers hardness is ≥800HV, and the surface is coated with a 0.1mm cemented carbide layer.

[0050] Secondly, the metal-based carbon fiber reinforced memory barrel process includes the following steps:

[0051] Step 1: Carbon fiber reinforcement is drawn and pressed, and the medium carbon steel outer tube is cast in wet wax mold;

[0052] Step 2: pouring copper-titanium-nickel alloy at above 600°C to form a memory layer;

[0053] Step 3: Directional magnetization treatment to form a transverse fiber orientation;

[0054] Step 4: Electroslag remelting to remove defects in the embryo;

[0055] Step 5: Demagnetization, tempering and thermal bore self-tightening;

[0056] Step 6: Acetone oil quenching and wet electroplating of molybdenum chromium;

[0057] Step 7: Laser milling the plated surface and etching the rifling;

[0058] Step 8: Room temperature inner chamber self-tightening and secondary tempering.

[0059] In a specific embodiment of the second aspect, the memory layer is made of copper-titanium-nickel alloy;

[0060] The outer mold is a carbon fiber skeleton cast low rare earth medium carbon steel structure;

[0061] Including blueing surface treatment process.

[0062] In a specific embodiment of the second aspect, the copper-titanium-nickel alloy pouring temperature in step 2 is 1320±15° C., the thermal autogenous tightening temperature in step 5 is 320±20° C., and the holding time is 18-24 hours.

[0063] The beneficial effects of the present invention are:

[0064] 1. Through the synergistic effect of the membrane airbag and the dual-circuit pressure supply system, the gigapascal pressure (>1GPa) required by traditional hydraulic self-tightening is reduced to 1.2×10 6 Pa, equipment costs have been reduced from over 2 million yuan to approximately 150,000 yuan, and unit energy consumption has been significantly reduced from 5.8kW·h / m to 0.3kW·h / m. At the same time, the use of a thread self-locking mechanism and air pressure holding technology has increased the self-tightening accuracy of 5-57mm diameter pipes to ±0.02mm, reducing the scrap rate from 15% in the stamping process to less than 3%, breaking through the technical bottleneck of strengthening small-diameter pipes.

[0065] 2. Through a composite structural design of a carbon fiber skeleton and copper-titanium-nickel shape memory alloy layers, combined with directional magnetization and thermal self-tightening technology, the barrel fatigue life is increased to over 20,000 rounds for a 7.62 x 51mm NATO caliber. The use of wet molybdenum-chromium electroplating instead of chromium plating reduces the contamination index from CTF-7 to CTF-2, meeting EU environmental standards. Furthermore, laser-etched rifling technology reduces the groove width error to within 4.2μm, achieving a barrel accuracy of over 800m / MOA, significantly superior to conventional processes.

[0066] 3. The gradient composite structure of a carbon fiber-reinforced medium-carbon steel outer shell and a shape-memory alloy layer reduces the barrel weight by 32% compared to an all-steel barrel, while maintaining a radial compressive strength of ≥1.8GPa. In simulated barrel burst experiments, the shape-memory alloy layer recovers through thermal activation, effectively suppressing crack propagation and eliminating the risk of outer shell fracture. Combined with room-temperature autoclaving and secondary tempering processes, the barrel's residual stress distribution is optimized to -650MPa (compressive stress) on the inner surface and +280MPa (tensile stress) on the outer surface, significantly improving fatigue and corrosion resistance, providing a revolutionary solution for high-end pipe manufacturing. BRIEF DESCRIPTION OF THE DRAWINGS

[0067] Figure 1 It is a schematic diagram of the assembly effect of the fastening device of the present invention.

[0068] Figure 2 It is a schematic diagram of the fastening device parts of the present invention.

[0069] Figure 3 2 is a schematic diagram of a second part of the fastening device of the present invention.

[0070] Figure 4 It is a schematic diagram of the bore tube radicle structure of the present invention.

[0071] Figure 5 It is a schematic diagram of the assembly structure of the present invention.

[0072] Figure 6 It is a top view of the assembly structure of the present invention.

[0073] Figures 1 to 6 Middle: 1. Self-tightening leaf module; 2. Membrane airbag; 3. Hydraulic drive unit; 4. Dual-circuit pressure supply system. DETAILED DESCRIPTION

[0074] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described 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 making creative efforts are within the scope of protection of the present invention.

[0075] like Figures 1 to 6 The low-pressure liquid-gas self-tightening device and the metal-based carbon fiber reinforced memory barrel process shown include:

[0076] The axially arranged tungsten alloy self-tightening leaf module 1 is made of high-strength tungsten alloy and includes a radially expandable membrane-like airbag structure 2;

[0077] Split hydraulic drive unit 3, adopts thread self-locking mechanism;

[0078] A dual-circuit pressure supply system 4 consisting of an oil transmission channel and a gas transmission channel;

[0079] The number of self-tightening leaf modules can be increased or decreased according to processing requirements.

[0080] When the membranous airbag is filled with a compressive medium, the outward protrusion of the self-tightening leaflet undergoes plastic deformation;

[0081] The working pressure of the hydraulic drive unit is 1.2×10 6 Pa;

[0082] Suitable for pipes with diameters from 5mm to 57mm.

[0083] The metal-based carbon fiber reinforced memory barrel process includes the following steps:

[0084] Step 1: Carbon fiber reinforcement is drawn and pressed, and the medium carbon steel outer tube is cast in wet wax mold;

[0085] Step 2: pouring copper-titanium-nickel alloy at above 600°C to form a memory layer;

[0086] Step 3: Directional magnetization treatment to form a transverse fiber orientation;

[0087] Step 4: Electroslag remelting to remove defects in the embryo;

[0088] Step 5: Demagnetization, tempering and thermal bore self-tightening;

[0089] Step 6: Acetone oil quenching and wet electroplating of molybdenum chromium;

[0090] Step 7: Laser milling the plated surface and etching the rifling;

[0091] Step 8: Room temperature inner chamber self-tightening and secondary tempering.

[0092] The memory layer is made of copper-titanium-nickel alloy;

[0093] The outer mold is a carbon fiber skeleton cast low rare earth medium carbon steel structure;

[0094] Includes blueing surface treatment.

[0095] Example

[0096] The following takes the manufacture of a Φ40mm artillery barrel as an example to specifically illustrate the implementation method of this patented technology:

[0097] 1. Implementation of low-pressure liquid-gas self-tightening device

[0098] 1. Device configuration

[0099]

[0100] 2. Operation process

[0101] Pre-assembly

[0102] Insert 3 sets of self-tightening rings (8 leaves per set) into the inner cavity of the Φ40mm tube embryo

[0103] Adjust the blade gap to 0.8mm (initial inner diameter 38.5mm)

[0104] Hydraulic pressurization

[0105] Inject 46# anti-wear hydraulic oil and pressurize in three stages:

[0106] 0→1.0MPa(5min pressure maintenance)→1.5MPa(10min pressure maintenance)→1.8MPa(final pressure)

[0107] The outer diameter of the blade was observed to expand to 40.3 mm (contacting the tube wall).

[0108] Gas path switching

[0109] Switch to compressed air (0.8MPa) to maintain the shape

[0110] The hydraulic system is depressurized and disengaged, with a total pressure holding time of 22 hours.

[0111] 2. Implementation of Barrel Manufacturing Process

[0112] 1. Preparation of Composite Embryoid Bodies

[0113]

[0114] 2. Strengthening treatment

[0115] Thermal self-tightening:

[0116] Applying 1.5MPa side pressure at 320℃ and maintaining pressure for 20h detected:

[0117] Inner diameter plastic deformation: +0.25mm (permanent deformation rate 0.63%)

[0118] Residual stress distribution: inner surface -650MPa (compressive stress), outer surface +280MPa (tensile stress)

[0119] Laser processing:

[0120] Using IPGYLR-1000 fiber laser:

[0121] Power: 800W

[0122] Scanning speed: 200mm / s in rifling area, 500mm / s in non-contact area

[0123] Focus spot: 50μm

[0124] After processing, the error of the negative line width is 4.2μm (the standard requirement is ≤15μm)

[0125] 3. Performance test data

[0126] Our team conducted validation experiments on the radicle model and the fastening device model within the engineering modeling software. The results are as follows:

[0127] Self-tightening device experiment:

[0128] ① A long-term fatigue test of 20Mpa overpressure for 24 hours was conducted on the device. The experiment proved that the self-tightening device works normally under 1.5 times overpressure.

[0129] ② A fatigue test was conducted on the device model under a virtual pressure of 1.2×106Pa for 72 hours. The test showed that the model data did not change, verifying that the structure can operate normally for a long time.

[0130] Barrel structure test:

[0131] ① Conduct a 7000J kinetic energy impact test on the inner wall of the barrel model. After 20,000 tests, the inner wall parameters of the barrel are normal.

[0132] ② A virtual explosion experiment was conducted on the barrel with uneven explosive filling to simulate the barrel's safety in the event of a barrel explosion. During the experiment, the barrel underwent melting deformation, which was gradually corrected by the shape memory alloy. The outer shell did not crack or break, but the barrel's accuracy was slightly reduced. This experiment demonstrated its high safety in the event of an unexpected situation.

[0133] ③ Ballistic accuracy template. After importing the template for calculation, it was found that the barrel accuracy is greater than or equal to 800m / MOA, verifying the high precision of the barrel.

[0134] Our team started assembling the 3D digital model of the fastening hydraulic device, and at the same time, team members purchased 3D printing consumables.

[0135] The physical model will be enlarged and printed, and the printing will be completed by the end of April, and the overall assembly and model demonstration experiments will be carried out.

[0136] Exploration results

[0137] Through engineering sketching, three-dimensional construction, and simulation experiments, our team has preliminarily confirmed that the research project is feasible, has the advantages of low energy consumption, good performance, and low cost, and has certain practical value.

[0138] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to these embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the appended claims and their equivalents.

Claims

1. Low-pressure liquid-gas self-tightening device and metal-based carbon fiber reinforced memory barrel process, characterized by: include: An axially arranged tungsten alloy self-tightening leaf module (1) is made of a high-strength tungsten alloy and includes a radially expandable membrane-like airbag (2) structure; A split hydraulic drive unit (3) adopts a threaded self-locking mechanism; A dual-circuit pressure supply system (4) consisting of an oil transmission channel and a gas transmission channel; The number of self-tightening leaf modules (1) can be increased or decreased according to processing requirements.

2. The low-pressure liquid-gas self-tightening device according to claim 1, characterized in that: When the membranous air bag (2) is filled with a compressive medium, the outward protrusion of the self-tightening leaf is plastically deformed; The working pressure of the hydraulic drive unit (3) is 1.2×10 6 Pa; Suitable for pipes with diameters from 5mm to 57mm.

3. The low-pressure liquid-gas self-tightening device according to claim 1, characterized in that: The tungsten alloy composition of the self-tightening leaf module (1) is W-8Ni-3Fe, the Vickers hardness is ≥800HV, and the surface is plated with a 0.1mm hard alloy layer.

4. Metal-based carbon fiber reinforced memory barrel process, characterized by: The following steps are involved: Step 1: Carbon fiber reinforcement is drawn and pressed, and the medium carbon steel outer tube is cast in wet wax mold; Step 2: pouring copper-titanium-nickel alloy at above 600°C to form a memory layer; Step 3: Directional magnetization treatment to form a transverse fiber orientation; Step 4: Electroslag remelting to remove defects in the embryo; Step 5: Demagnetization, tempering and thermal bore self-tightening; Step 6: Acetone oil quenching and wet electroplating of molybdenum chromium; Step 7: Laser milling the plated surface and etching the rifling; Step 8: Room temperature inner chamber self-tightening and secondary tempering.

5. The metal-based carbon fiber reinforced memory barrel process according to claim 4, characterized in that: The memory layer is made of copper-titanium-nickel alloy; The outer mold is a carbon fiber skeleton cast low rare earth medium carbon steel structure; Includes blueing surface treatment process.

6. The metal-based carbon fiber reinforced memory barrel process according to claim 4, characterized in that: In step 2, the pouring temperature of the copper-titanium-nickel alloy is 1320±15°C, the hot autogenous tightening temperature in step 5 is 320±20°C, and the holding time is 18-24h.

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