A method for processing a pressure hull of an unmanned underwater vehicle

Abstract

The application discloses a kind of unmanned underwater vehicle pressure hull processing method, it is related to underwater vehicle technical field, the technical points of the present application: first respectively using titanium alloy forging pipe material or bar material, cake material, sheet material, by customizing raw material, preset parameter machine, hole making, cleaning, cooperate with ray detection to complete shell, head, clamp processing, head still needs laser marking mark.Assembling stage, O-shaped sealing ring sealing is arranged at the connecting part of shell and head, and the plug of through-cabin part is fixed and assembled by clamp.Then, the vacuum degree change is monitored by vacuum pressure maintaining mode for air tightness detection, and after passing, hydrostatic pressure test is used, the pressure is increased according to preset pressure step and is maintained to the specified time length, whether deformation leakage is detected, finally the pressure hull processing is completed, the structural strength and sealing performance are guaranteed, and the underwater use demand is met.

Description

Technical Field

[0001] This invention relates to the field of underwater vehicle technology, and in particular to a method for processing a pressure hull for an unmanned underwater vehicle. Background Technology

[0002] Unmanned underwater vehicles (UUVs) need to operate in complex underwater environments for extended periods. Their pressure hulls, as the core load-bearing and protective structure, directly impact the overall safety, reliability, and operational efficiency of the vehicle. Therefore, extremely high requirements are placed on the hull's structural strength, sealing performance, and dimensional accuracy. The manufacturing of the pressure hull involves multiple critical stages, including raw material processing, machining, component assembly, and quality inspection. The quality and coordination of each stage are crucial, requiring systematic control to ensure the hull can withstand pressure impacts at different depths underwater, while preventing water infiltration and damage to the equipment due to seal failure. However, traditional manufacturing methods fail to achieve integrated coordination across these stages, exhibiting significant shortcomings in raw material compatibility, parameter control, assembly processes, and testing methods. This makes it difficult to balance component precision, overall sealing performance, and production efficiency, and cannot fully meet the high-performance requirements of UUVs for pressure hulls. A more precise and efficient manufacturing solution is urgently needed to overcome existing technological bottlenecks.

[0003] The first significant drawback of existing technologies lies in the processing stage. Traditional processing does not utilize customized raw materials suitable for the pressure hull requirements, and the machining parameters lack scientific pre-setting and precise control. This leads to dimensional deviations in core components such as titanium alloy hulls, end caps, and clamps after processing. Some components may also experience structural deformation or hidden defects due to mismatch between raw materials and processing parameters, which not only compromises the structural integrity of the components but also creates difficult-to-correct problems in subsequent assembly stages, directly affecting the overall structural strength of the pressure hull. The second drawback exists in the testing process. Existing airtightness testing does not combine vacuum pressure holding with real-time monitoring, and pressure testing does not employ a scientific method of stepped pressure increase and holding tests. This fails to comprehensively cover the leakage risks and structural deformation hazards of the hull and connecting parts, often resulting in missed defects or inaccurate test results. This allows pressure hulls that do not meet safety standards to enter subsequent use stages, seriously threatening the operational safety of unmanned underwater vehicles during underwater operations. Summary of the Invention

[0004] In order to overcome the shortcomings and deficiencies of the existing technology, the present invention provides a method for processing the pressure hull of an unmanned underwater vehicle.

[0005] The technical solution adopted in this invention is a method for processing a pressure hull for an unmanned underwater vehicle, comprising the following steps: S1. Processing a titanium alloy hull, using titanium alloy forged tubes or bars for integral machining. First, custom-made tubes or bars that meet the size requirements are selected. Then, the inner surface, outer surface, and length of the tubes or bars are machined according to preset machining parameters. Subsequently, holes are drilled at preset positions on the hull. After machining, the hull is cleaned. Finally, non-destructive testing of the hull is performed using X-ray inspection technology. S2. Processing a titanium alloy end cap, using titanium alloy discs for integral machining. First, custom-made discs that meet the material and size requirements are selected. Then, the inner surface, outer surface, and length of the discs are machined according to preset machining parameters. Simultaneously, connector mounting holes are machined and drilled at preset positions. After machining, the end cap is cleaned. Non-destructive testing of the end cap is performed using X-ray inspection technology. Finally, markings are made on the surface of the end cap using laser engraving. S3. Processing titanium alloy clamps, using titanium alloy plates for integral machining. Forming: First, in the sheet metal workshop, titanium alloy sheets are cut to preset dimensions. Then, the inner and outer surfaces and height of the cut sheets are machined according to preset machining parameters. Next, holes are drilled at preset positions on the sheets, and finally, cuts are made at designated positions. After machining, the clamps are cleaned. S4: The shell and head are assembled and connected. O-rings are used to seal the connection between the shell and head. The sealed shell and head are assembled and fixed using clamps. Simultaneously, the plugs for the through-chamber components are assembled. S5: The assembled pressure shell undergoes an airtightness test. A vacuum pressure holding method is used to evacuate the gas inside the pressure shell to a preset vacuum level. After closing the air valve, the change in the vacuum level inside the shell is monitored using a pressure gauge to determine if the airtightness meets the standard. S6: The pressure shell that passes the airtightness test undergoes a pressure test. A hydrostatic pressure test is conducted. The pressure is increased using a stepped pressure increase method according to the preset test pressure and held for a preset time to check for deformation and leakage in the pressure shell.

[0006] Furthermore, when machining the titanium alloy shell in S1, the shell thickness deviation control model is as follows: ,in, This indicates the shell thickness deviation value. Indicates the actual machined thickness of the shell. Indicates the standard thickness of the casing. Indicates the temperature effect coefficient. This indicates the amount of temperature change during the processing. This represents the coefficient of influence of processing speed. This represents the machining speed; simultaneously, the calculation model for the dimensional deviation of the outer surface of the shell is: ,in, This indicates the dimensional deviation of the outer surface of the casing. This indicates the actual dimension of the outer surface of the shell in the x-direction. This indicates the standard dimension of the outer surface of the housing in the x-direction. This indicates the actual dimension of the outer surface of the shell in the y-direction. This indicates the standard dimension of the outer surface of the housing in the y-direction. This represents the influence coefficient of processing time. This indicates the machining time.

[0007] Furthermore, when machining titanium alloy heads in S2, the calculation model for the positional accuracy of the head connector mounting hole seat is as follows: ,in, This indicates the positional accuracy of the hole seat. This indicates the actual coordinates of the hole seat in the x-direction. This represents the standard coordinate of the hole seat in the x-direction. This indicates the actual coordinates of the hole seat in the y-direction. This indicates the standard coordinates of the hole seat in the y-direction. This represents the actual coordinates of the hole seat in the z-direction. This represents the standard coordinates of the hole seat in the z-direction. Indicates the influence coefficient of processing force. This represents the force applied during the machining process; and the laser marking clarity evaluation model is as follows: ,in, This indicates the signage clarity assessment value. Indicates the reference light intensity for laser marking. This indicates the actual light intensity during laser engraving. Indicates the influence coefficient of engraving depth. This indicates the actual depth of the laser engraving.

[0008] Furthermore, when machining titanium alloy clamps in S3, the clamp cut dimension accuracy control model is as follows: ,in, This indicates the deviation value of the clamp cut size. This indicates the actual size of the clamp cut. This indicates the standard dimensions of the clamp cut. This represents the coefficient of influence of changes in processing speed. Indicates the change in processing speed. This represents the coefficient of influence of changes in processing force. This represents the change in processing force; simultaneously, the calculation model for the inner surface roughness of the clamp is: ,in, This indicates the surface roughness value of the clamp's inner surface. This indicates the surface roughness of the clamp substrate. This represents the influence coefficient of polishing time. Indicates the polishing process time. This indicates the influence coefficient of polishing pressure. This indicates the pressure applied during the polishing process.

[0009] Furthermore, during assembly and connection in S4, the O-ring sealing performance evaluation model is as follows: ,in, This indicates the sealing performance evaluation value. This indicates the maximum permissible pressure difference of the sealing ring. This indicates the actual pressure difference between the sealing rings. This indicates the influence coefficient of assembly temperature. This indicates the amount of temperature change during the assembly process. This indicates the influence coefficient of assembly pressure. This represents the clamping force during the assembly process; and the calculation model for the tightness of the clamp assembly is as follows: ,in, This indicates the tightness value of the clamp assembly. This indicates the actual tightening force of the clamp. This indicates the minimum allowable tightening force of the clamp. This indicates the maximum allowable tightening force of the clamp. This represents the influence coefficient of assembly time. This indicates the change in assembly time. This represents the coefficient affecting assembly speed. This indicates the change in assembly speed.

[0010] Furthermore, when performing airtightness testing in S5, the calculation model for the rate of change of vacuum degree is as follows: ,in, Indicates the rate of change of vacuum degree. Indicates the vacuum level at the initial moment of detection. Indicates the vacuum level at the end of the test. Indicates the start time of the detection. Indicates the end time of the test. This represents the initial vacuum level influence coefficient. This represents the initial vacuum level. This indicates the influence coefficient of the detection temperature. This represents the temperature change during the testing process; simultaneously, the threshold model for determining airtightness is: ,in, This indicates the threshold for determining whether airtightness is acceptable. Indicates the basic judgment threshold. This represents the influence coefficient of pressure holding time. Indicates the holding time. Indicates the environmental pressure influence coefficient. This indicates the environmental pressure being tested.

[0011] Further, S3 specifically includes the following sub-steps: S3.1. At the sheet metal workshop, mark the cutting outline on the titanium alloy sheet according to the design dimensions and shape parameters of the clamp, and use special equipment to cut along the outline, controlling the cutting speed and depth to avoid deformation or defects; S3.2. Adjust the tool rotation speed, feed rate and cutting depth of the equipment according to the preset machining parameters. First, rough-machine the outer surface of the sheet to remove excess material, and then finish-machine it to the design standard. Machine the inner surface in the same way to ensure coaxiality; S3.3. Determine the position, quantity and size of the holes according to the clamp assembly requirements, drill holes with special equipment, make positioning marks before drilling, control the drilling speed and pressure, and polish the inner surface of the holes after completion; S3.4. Determine the notch parameters according to the clamp structure design, process the notch with cutting equipment, monitor the accuracy in real time and adjust the parameters, and chamfer the notch edge after processing to remove sharp edges.

[0012] Further, S4 specifically includes the following sub-steps: S4.1. Clean the oil stains and impurities at the connection part between the shell and the head, check the flatness and dimensional accuracy, and if it exceeds the standard, use grinding equipment to correct it to meet the assembly requirements; S4.2. Select a suitable O-ring seal and place it in the preset sealing groove, ensure no distortion or deformation, and apply special sealing grease on the surface of the seal; S4.3. Put the clamp on the connection part and align the mounting holes, insert the bolts, and use a torque wrench to gradually tighten symmetrically according to the preset torque to ensure uniform clamping force; S4.4. Select a suitable through-hull fitting plug, clean the inner surface of the mounting hole, apply sealant on the sealing surface of the plug and then insert it into the hole, and control the tightening force to fix the plug.

[0013] Further, S5 specifically includes the following sub-steps: S5.1. Connect the pressure-resistant shell with the vacuum pumping equipment and the pressure gauge with special pipes and ensure sealing, and check the operating status of each component to meet the detection requirements; S5.2. Start the vacuum pumping equipment to pump out the gas inside the shell, monitor the pressure gauge in real time, and close the valve to maintain the vacuum state after reaching the preset vacuum degree; S5.3. Start timing after closing the valve, regularly record the pressure gauge readings within the preset pressure holding duration, and check and handle the leakage points if the vacuum degree drops significantly; S5.4. Compare the vacuum degrees before and after pressure holding. If the change amount is within the allowable range, it is determined that the airtightness is qualified; if it exceeds the standard, re-check and handle it until it meets the standard.

[0014] The beneficial technical effects of this invention are as follows: This invention proposes a method for processing the pressure hull of an unmanned underwater vehicle. Through integral machining of the titanium alloy hull, end caps, and clamps, combined with multi-stage non-destructive testing and a refined assembly and inspection process, it achieves significant beneficial effects. In the processing stage, customized raw materials and preset parameters are used for machining, along with targeted cleaning and inspection, effectively improving the dimensional accuracy and structural integrity of each component. This avoids component deformation or defects caused by poor material compatibility and improper parameter control in traditional processing. During assembly, O-ring sealing, symmetrical clamp tightening, and precise assembly of through-hull plugs, combined with the use of sealing grease and sealant, greatly enhance overall sealing performance, solving the problems of sealing failure and uneven tightening force at connection points in the prior art. Air tightness testing employs vacuum pressure holding and real-time monitoring. Pressure testing uses stepped pressure increase and holding tests to comprehensively identify potential leaks and deformations, overcoming the shortcomings of missed defects and inaccurate judgments in existing testing methods. The overall process achieves integrated management and control of processing, assembly, and testing, improving the structural strength, sealing performance, and safety and reliability of the pressure hull, meeting the usage requirements of unmanned underwater vehicles in complex underwater environments, while reducing repetitive processing and testing operations and improving production efficiency. Attached Figure Description

[0015] Figure 1 This is a flowchart of the method steps of the present invention;

[0016] Figure 2 This is a diagram showing the unit composition of the method implementation of the present invention;

[0017] Figure 3 This is a schematic diagram of the structure of the pressure-resistant shell of the battery compartment of the present invention;

[0018] Figure 4 This is a schematic diagram of the structure of the pressure-resistant shell of the instrument compartment of the present invention;

[0019] Figure 5 This is a schematic diagram of the structure of the pressure-resistant shell of the power distribution compartment of the present invention;

[0020] Figure 6 This is a schematic diagram of the pressure-resistant shell of the emergency safety electronic compartment of the present invention.

[0021] In the diagram, 1 is the front end cap; 2 is the shell; 201 is the reinforcing rib; 202 is the threaded hole; 3 is the rear end cap; 4 is the clamp; and 5 is the end cap. Detailed Implementation

[0022] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. The application will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0023] like Figure 1As shown, a method for processing a pressure hull for an unmanned underwater vehicle includes the following steps:

[0024] S1. Machining the titanium alloy shell: The titanium alloy forged tube or bar is integrally machined. First, the tube or bar that meets the size requirements is customized. Then, the inner surface, outer surface and length of the tube or bar are machined according to the preset machining parameters. Then, holes are made in the preset position of the shell. After the machining is completed, the shell is cleaned. Finally, the shell is non-destructively inspected using X-ray inspection technology.

[0025] Specifically, S1 aims to manufacture a titanium alloy hull that meets the pressure resistance requirements of unmanned underwater vehicles through a monolithic machining process. Titanium alloy is a high-strength, corrosion-resistant material that can withstand complex underwater pressure environments. Monolithic machining avoids the weaknesses in strength caused by spliced ​​structures, ensuring the overall structural stability of the hull. Subsequent cleaning and radiographic testing are used to remove residual impurities from machining and to check for internal defects, respectively, providing quality assurance for the subsequent assembly and underwater use of the hull and ensuring that the hull does not experience structural failure within the preset underwater depth range.

[0026] In practice, first, custom-made titanium alloy forged tubes or bars with a diameter range of 300-500 mm and a length of 800-1200 mm are prepared, with the initial wall thickness controlled at 15-25 mm. Following preset machining parameters, the tubes or bars are fixed on a CNC machining center, with the tool speed set to 800-1200 rpm and the feed rate controlled at 100-200 mm / min. The outer surface is machined to ensure the final outer diameter error is controlled within ±0.1 mm; after machining the inner surface, the inner diameter error is controlled within ±0.2 mm, and the length is machined to the preset dimensions with an error not exceeding ±0.5 mm. Holes with a diameter of 8-12 mm are drilled at axial intervals of 200-300 mm around the shell. After machining, the shell is soaked in industrial cleaning agent for 30-60 minutes, then rinsed with a high-pressure water gun. Finally, a radiographic inspection device with an energy of 1.5-2.5 MeV is used to scan the entire length of the shell to ensure there are no internal cracks, porosity, or other defects.

[0027] S2. Processing titanium alloy heads: The titanium alloy blank is integrally machined. First, a blank that meets the material and size requirements is customized. Then, the inner surface, outer surface and length of the blank are machined according to the preset machining parameters. At the same time, the connector mounting hole seat is machined and the hole is drilled at the preset position. After machining, the head is cleaned. Radiographic testing technology is used to perform non-destructive testing on the head. Finally, the marking is made on the surface of the head by laser engraving process.

[0028] Specifically, S2 manufactures titanium alloy end caps that fit the shell through integral machining. As the end structure of the pressure-resistant shell, the end caps need to have good sealing compatibility and structural strength. The machining of the connector mounting holes provides a foundation for subsequent equipment installation. Laser engraving marks facilitate subsequent assembly identification and quality traceability. Cleaning and X-ray inspection ensure the machining accuracy and internal quality of the end caps, avoiding the impact of end cap defects on the overall sealing performance and structural safety of the pressure-resistant shell.

[0029] In practice, a titanium alloy blank with a diameter matching the shell and a thickness of 20-30 mm is first customized. The blank is fixed in the machining equipment, with the tool speed set to 600-1000 rpm and the feed rate controlled at 80-150 mm / min. The outer surface of the blank is machined to ensure its radius of curvature error is within ±0.3 mm. After machining the inner surface, the gap between the blank and the shell mating surface is controlled within 0.1-0.2 mm, and the length is machined to 50-80 mm with an error not exceeding ±0.3 mm. Simultaneously, connector mounting holes with a diameter of 20-30 mm and a depth of 15-25 mm are machined, and holes with a diameter of 5-8 mm are made at intervals of 10-15 mm around the mounting holes. After machining, the blank is cleaned with an ultrasonic cleaner for 20-40 minutes and inspected using a radiographic inspection device with the same parameters as the shell. Finally, a laser marking device with a wavelength of 1064 nm is used to create a marking on the outer surface of the head containing material and batch information, with characters 2-3 mm high.

[0030] S3. Processing titanium alloy clamps: The titanium alloy sheet is integrally machined. First, the titanium alloy sheet is cut into blanks according to the preset dimensions in the sheet workshop. Then, the inner surface, outer surface and height of the blanked sheet are machined according to the preset machining parameters. Then, holes are made in the preset positions of the sheet. Finally, cuts are made in the specified positions of the sheet. After the machining is completed, the clamp is cleaned.

[0031] Specifically, the S3-machined titanium alloy clamps are used for the subsequent assembly and fixation of the shell and end cap. The integral machining process ensures that the clamps have sufficient clamping strength and structural stability, preventing loosening of the connection after assembly due to insufficient clamp strength. The cutting accuracy and machining parameter control directly affect the compatibility of the clamps with the shell and end cap. The hole-making and slit-making operations provide conditions for clamp installation and fixation and structural clearance, respectively. Cleaning removes machining residues, ensuring the fit of the clamps during assembly, thereby improving the assembly reliability of the overall pressure-resistant shell.

[0032] In practice, titanium alloy plates with a thickness of 8-12 mm and a width of 50-80 mm are selected in the sheet metal workshop. Based on the clamp circumference, CNC shearing equipment is used to cut the plates, with the dimensional error controlled within ±0.5 mm. The cut plates are then fixed on a milling machine, with the cutter speed set to 1000-1500 rpm and the feed rate controlled at 150-250 mm / min. The inner surface is machined to achieve a surface roughness controlled within Ra1.6-Ra3.2 micrometers; the outer surface is machined to a flatness error not exceeding 0.1 mm, and the height is machined to 30-50 mm, with an error controlled within ±0.2 mm. Holes with a diameter of 10-14 mm are made at intervals of 20-30 mm at both ends of the plate. A cut with a width of 15-20 mm and a depth of 10-15 mm is made on one side of the plate. After machining, surface debris is removed using a high-pressure air jet, and the plate is then wiped clean with alcohol to ensure no machining residue remains.

[0033] S4. Assemble and connect the shell and the head, and install an O-ring seal at the connection between the shell and the head for sealing. Use clamps to assemble and fix the sealed shell and head, and at the same time complete the assembly operation of the plug of the through compartment.

[0034] Specifically, S4 is a crucial step in assembling the processed shell and head into a single structure. The O-ring seal is essential for ensuring the sealing performance of the connection, effectively preventing underwater liquids from seeping into the shell. The clamp assembly provides clamping force to the shell and head, ensuring a tight fit and preventing loosening due to changes in underwater pressure. The assembly of the plugs sealing the pre-drilled holes further guarantees overall sealing. These coordinated operations lay a solid foundation for subsequent airtightness testing.

[0035] In practice, first clean the connection between the shell and the end cap by wiping with a lint-free cloth dampened with acetone to remove oil and impurities. Select an O-ring with a cross-sectional diameter of 5-8 mm made of fluororubber and embed it into the pre-set sealing groove at the shell connection end. The depth of the sealing groove should be 0.2-0.3 mm smaller than the diameter of the O-ring, ensuring that the O-ring completely fits the groove wall. Place the clamp on the connection between the shell and the end cap and adjust its position so that the hole on the clamp aligns with the hole on the shell and the end cap, with an alignment error controlled within 0.1-0.2 mm. Insert titanium alloy bolts with a diameter matching the hole diameter and tighten them gradually in a symmetrical circumferential sequence using a torque wrench at a torque value of 20-30 N·m. After tightening each bolt, check the gap at the connection to ensure that the gap does not exceed 0.1 mm. At the same time, select a plug that matches the mounting hole of the through-cabin part, apply silicone rubber sealant with a thickness of 0.1-0.2 mm to the sealing surface of the plug, insert the plug into the hole, and use a wrench to fix it with a torque of 15-25 N·m.

[0036] S5. Perform an airtightness test on the assembled pressure-resistant housing. Use a vacuum pressure holding method to evacuate the gas inside the pressure-resistant housing to a preset vacuum level. After closing the air valve, monitor the change in the vacuum level inside the housing using a pressure gauge to determine whether the airtightness meets the standard.

[0037] Specifically, the S5 airtightness test is a crucial step in verifying the sealing performance of the pressure-resistant housing. The vacuum pressure holding method simulates an underwater negative pressure environment, allowing for precise detection of even minor leaks by monitoring changes in vacuum levels. Compared to conventional pneumatic testing, vacuum pressure holding can more sensitively detect sealing defects, preventing leaks during subsequent pressure testing due to poor sealing, or liquid infiltration that could damage internal equipment during underwater use. This provides direct verification of the sealing reliability of the pressure-resistant housing.

[0038] In practice, the pressure-resistant housing is connected to a vacuum pump and a precision pressure gauge via a dedicated pipeline. The pipeline joints are sealed with sealing rings to ensure no additional leakage. The vacuum pump is started to extract the gas from inside the housing, and the pressure gauge reading is monitored in real time. When the pressure drops to the preset vacuum level of -0.095 to -0.098 MPa, the pump valve is closed. After closing the valve, a timer is started. During the 30-60 minute pressure holding period, the pressure gauge reading is recorded every 5-10 minutes. If the vacuum level change during the pressure holding period does not exceed 0.002 MPa, the airtightness is considered to meet the standard. If the change exceeds this limit, the pipeline connections, the connection between the housing and the end cap, and the plug assembly must be checked to locate the leak and reseal it until the vacuum level change meets the requirements.

[0039] S6. Perform a pressure test on the pressure-resistant shell that has passed the airtightness test. Use a hydrostatic pressure test, pressurize according to the preset test pressure through a step-by-step pressurization method, and hold the pressure for the preset time to check whether the pressure-resistant shell is deformed or leaking.

[0040] Specifically, the S6 pressure test is used to verify the structural strength and anti-leakage capability of the pressure hull. The hydrostatic pressure test can simulate the actual underwater pressure environment. The stepped pressure increase method avoids deformation or damage to the hull due to excessive instantaneous stress caused by a sudden increase in pressure. The pressure holding process can further observe the stability of the hull under continuous pressure, ensuring that the hull does not undergo structural deformation or leakage within the preset underwater working depth and a certain safety margin, thus ensuring the underwater operation safety of the unmanned underwater vehicle.

[0041] During specific implementation, the pressure-resistant shell that has passed the airtightness test is completely immersed in the hydrostatic test tank. It is connected to the inside of the shell through a pressurization device, and a stepped pressure increase method is adopted. First, the pressure is increased to 1 - 2 MPa and kept for 5 - 10 minutes; then it is increased to 3 - 5 MPa and kept for 10 - 15 minutes; finally, it is increased to the preset test pressure of 8 - 12 MPa and kept for 20 - 30 minutes. During the pressure holding period, observe whether there are bubbles on the outer surface of the shell through the observation window of the test tank, and at the same time use a micrometer to measure the outer diameter changes in the middle and both ends of the shell. If there are no bubbles during the pressure holding period and the outer diameter change does not exceed 0.5 mm, it is determined that the pressure test is qualified; if bubbles appear or the outer diameter change exceeds the standard, the shell structure needs to be inspected, and after repairing the defects, the airtightness test and the pressure test are carried out again until the standard is met.

[0042] Preferably, when processing the titanium alloy shell in S1, the shell thickness deviation control model is: , where represents the shell thickness deviation value, represents the actual processed thickness of the shell, represents the standard thickness of the shell, represents the temperature influence coefficient, represents the temperature change amount during the processing, represents the processing speed influence coefficient, represents the machining speed; at the same time, the shell outer surface dimension deviation calculation model is: , where represents the shell outer surface dimension deviation value, represents the actual dimension of the shell outer surface in the x direction, represents the standard dimension of the shell outer surface in the x direction, represents the actual dimension of the shell outer surface in the y direction, represents the standard dimension of the shell outer surface in the y direction, represents the processing time influence coefficient, represents the machining time.

[0043] Specifically, for the S1 titanium alloy shell machining process, the control methods for thickness deviation and outer surface dimensional deviation are further refined, and precise control of machining accuracy is achieved through specific calculation logic. During shell machining, thickness deviation control needs to comprehensively consider the basic difference between the actual machined thickness and the standard thickness, while also incorporating the influence factors of temperature and machining speed. The temperature influence coefficient is set to 0.02-0.05 based on the material characteristics of titanium alloy, and the temperature change during machining is usually controlled within ±5℃. The machining speed influence coefficient is set to 0.01-0.03, and the machining speed is maintained at 800-1200 rpm. Through the synergistic calculation of these parameters, the shell thickness deviation can be controlled within ±0.05 mm, avoiding uneven thickness caused by ignoring a single factor. The calculation of external surface dimensional deviation focuses on the difference between the actual dimensions and the standard dimensions in both the x and y directions. The comprehensive deviation is represented by the sum of squares and the square root, while a machining time influence coefficient is introduced. This coefficient is set to 0.005-0.01 based on the stability of the machining equipment. The machining time is controlled between 2-4 hours based on the shell length to ensure that the external surface dimensional deviation does not exceed ±0.1 mm. During implementation, a temperature sensor and speed monitoring module are installed in the CNC machining center to collect real-time temperature changes and machining speed data, simultaneously recording dimensional data in the x and y directions. Machining parameters are adjusted in real-time through preset calculation logic. When the thickness deviation approaches the threshold, the machining speed is automatically fine-tuned or the cooling system is adjusted to control the temperature. When the external surface dimensional deviation exceeds the limit, the tool feed path is adjusted. Ultimately, dynamic control of the shell machining accuracy is achieved, providing a fundamental guarantee for subsequent assembly and pressure resistance performance.

[0044] Preferably, when machining titanium alloy heads in S2, the calculation model for the positional accuracy of the head connector mounting hole seat is as follows: ,in, This indicates the positional accuracy of the hole seat. This indicates the actual coordinates of the hole seat in the x-direction. This represents the standard coordinate of the hole seat in the x-direction. This indicates the actual coordinates of the hole seat in the y-direction. This indicates the standard coordinates of the hole seat in the y-direction. This represents the actual coordinates of the hole seat in the z-direction. This represents the standard coordinates of the hole seat in the z-direction. Indicates the influence coefficient of processing force. This represents the force applied during the machining process; and the laser marking clarity evaluation model is as follows: ,in, This indicates the signage clarity assessment value. Indicates the reference light intensity for laser marking. This indicates the actual light intensity during laser engraving. Indicates the influence coefficient of engraving depth. This indicates the actual depth of the laser engraving.

[0045] Specifically, the processing of S2 titanium alloy heads focuses on optimizing the control methods for the positional accuracy of connector mounting holes and the clarity of laser-engraved markings. Multi-factor calculations are used to improve the processing quality of key parts of the head. The hole mounting positional accuracy calculation needs to cover coordinate deviations in the x, y, and z spatial directions. The difference between the actual coordinates and the standard coordinates is converted into a comprehensive accuracy value through square root calculations. The influence of processing force is also considered; the processing force influence coefficient is set to 0.003-0.008 based on the hardness of the titanium alloy blank. The force applied during machining is controlled within 500-800 Newtons to ensure that the hole mounting positional accuracy is controlled within ±0.15 mm, avoiding difficulties in subsequent connector assembly due to hole position deviations. The clarity assessment of laser-engraved markings is based on the ratio of the difference between the reference light intensity and the actual light intensity, introducing an engraving depth influence coefficient. This coefficient is set to 0.01-0.04 according to the laser equipment power, and the actual laser engraving depth is controlled between 0.1-0.3 mm to maintain the marking clarity assessment value above 0.8, ensuring that the markings remain clearly identifiable even after long-term underwater use. During implementation, a three-dimensional coordinate measuring instrument is installed on the processing equipment to collect spatial coordinate data in real time during the hole-base processing. Simultaneously, a force sensor monitors the processing force. When the accuracy value approaches the upper limit, the tool cutting angle and feed rate are adjusted. The reference light intensity is calibrated before laser engraving, and the engraving depth is monitored in real time during the engraving process using a depth measuring instrument. If the clarity assessment value is lower than the standard, the laser power and engraving speed are adjusted to ensure the adaptability of the hole-base assembly and the effectiveness of marking traceability, avoiding the impact of end-cap processing defects on the overall pressure-resistant shell function.

[0046] Preferably, when machining titanium alloy clamps in S3, the clamp cut dimension accuracy control model is as follows: ,in, This indicates the deviation value of the clamp cut size. This indicates the actual size of the clamp cut. This indicates the standard dimensions of the clamp cut. This represents the coefficient of influence of changes in processing speed. Indicates the change in processing speed. This represents the coefficient of influence of changes in processing force. This represents the change in processing force; simultaneously, the calculation model for the inner surface roughness of the clamp is: ,in, This indicates the surface roughness value of the clamp's inner surface. This indicates the surface roughness of the clamp substrate. This represents the influence coefficient of polishing time. Indicates the polishing process time. This indicates the influence coefficient of polishing pressure. This indicates the pressure applied during the polishing process.

[0047] Specifically, the machining of S3 titanium alloy clamps improves the adaptability and fit of the clamp structure by calculating and controlling the kerf size deviation and internal surface roughness. The kerf size deviation control needs to consider the absolute difference between the actual size and the standard size, while also incorporating the effects of changes in machining speed and machining force. The influence coefficient for machining speed variation is set at 0.002-0.006, with the machining speed variation controlled within ±100 rpm. The influence coefficient for machining force variation is set at 0.004-0.009, with the machining force variation maintained within ±50 N, ensuring that the kerf size deviation does not exceed ±0.2 mm, thus preventing the clamp from failing to install properly due to kerf deviation. The internal surface roughness calculation is based on the basic roughness of the substrate, superimposed with the effects of polishing time and polishing pressure. The polishing time influence coefficient is set to 0.05-0.12, and the polishing time is controlled at 10-20 minutes. The polishing pressure influence coefficient is set to 0.03-0.08, and the polishing pressure is maintained at 20-40 Newtons, so that the internal surface roughness value is controlled within Ra1.6-Ra3.2 micrometers, ensuring the tight fit between the clamp and the shell and end cap. During implementation, a speed monitor and force sensor are installed on the CNC shearing equipment to record the changes in processing speed and processing force in real time. When the kerf size deviation approaches the threshold, the shearing speed or pressure is adjusted. After the internal surface is processed, the surface roughness is tested using a roughness measuring instrument. If the value exceeds the standard, the polishing time is extended or the polishing pressure is adjusted to ensure the clamp kerf fit and the smoothness of the internal surface, avoiding assembly loosening due to clamp processing problems and improving the overall structural stability.

[0048] Preferably, when assembling and connecting in S4, the O-ring sealing performance evaluation model is as follows: ,in, This indicates the sealing performance evaluation value. This indicates the maximum permissible pressure difference of the sealing ring. This indicates the actual pressure difference between the sealing rings. This indicates the influence coefficient of assembly temperature. This indicates the amount of temperature change during the assembly process. This indicates the influence coefficient of assembly pressure. This represents the clamping force during the assembly process; and the calculation model for the tightness of the clamp assembly is as follows: ,in, This indicates the tightness value of the clamp assembly. This indicates the actual tightening force of the clamp. This indicates the minimum allowable tightening force of the clamp. This indicates the maximum allowable tightening force of the clamp. This represents the influence coefficient of assembly time. This indicates the change in assembly time. This represents the coefficient affecting assembly speed. This indicates the change in assembly speed.

[0049] Specifically, in the S4 assembly and connection process, the sealing performance and clamp tightness are calculated and evaluated to ensure the sealing and stability of the connection between the shell and the end cap. The O-ring sealing performance evaluation focuses on the ratio of the difference between the maximum allowable pressure difference and the actual pressure difference, while also considering the effects of assembly temperature and assembly pressure. The assembly temperature influence coefficient is set at 0.005-0.011, and the temperature change during assembly is controlled within ±3℃. The assembly pressure influence coefficient is set at 0.007-0.013, and the clamping force during assembly is controlled at 100-150 Newtons to maintain the sealing performance evaluation value above 0.9, ensuring that no liquid seeps into the connection area. The clamp assembly tightness calculation is based on the ratio of the difference between the actual tightening force and the minimum allowable tightening force to the difference between the maximum and minimum allowable tightening forces. The effects of assembly time and speed variations are taken into account. The assembly time influence coefficient is set at 0.003-0.008, with the variation controlled within ±5 minutes. The assembly speed influence coefficient is set at 0.002-0.006, with the assembly speed maintained at 5-10 mm / s, ensuring the tightness value is controlled between 0.7-1.0, avoiding connection problems caused by insufficient or excessive tightening force. During implementation, pressure and temperature sensors are installed at the assembly station to monitor the sealing pressure and assembly temperature in real time. When the sealing performance evaluation value approaches the lower limit, the sealing ring specification is adjusted or the tightening force is increased. The clamp tightening force is recorded using a torque wrench, and the tightness is calculated based on the assembly time and speed data. If the value is abnormal, the bolt tightening sequence or torque value is adjusted to ensure reliable and stable sealing of the assembly connection, laying a good foundation for subsequent airtightness testing.

[0050] Preferably, when performing airtightness testing in S5, the calculation model for the vacuum degree change rate is as follows: ,in, Indicates the rate of change of vacuum degree. Indicates the vacuum level at the initial moment of detection. Indicates the vacuum level at the end of the test. Indicates the start time of the detection. Indicates the end time of the test. This represents the initial vacuum level influence coefficient. This represents the initial vacuum level. This indicates the influence coefficient of the detection temperature. This represents the temperature change during the testing process; simultaneously, the threshold model for determining airtightness is: ,in, This indicates the threshold for determining whether airtightness is acceptable. Indicates the basic judgment threshold. This represents the influence coefficient of pressure holding time. Indicates the holding time. Indicates the environmental pressure influence coefficient. This indicates the environmental pressure being tested.

[0051] Preferably, S3 specifically includes the following steps: S3.1 In the sheet metal workshop, according to the design dimensions and shape parameters of the clamp, mark the material outline on the titanium alloy sheet, and use special equipment to cut along the outline, controlling the cutting speed and depth to avoid deformation or defects; S3.2 Adjust the tool speed, feed rate and cutting depth of the equipment according to the preset machining parameters, first rough machine the outer surface of the sheet to remove excess material, and then finish machine to the design standard, and machine the inner surface in the same way to ensure coaxiality; S3.3 Determine the position, number and size of the holes according to the clamp assembly requirements, drill the holes with special equipment, mark the positioning before drilling, control the drilling speed and pressure, and grind the inner surface of the holes after completion; S3.4 Determine the cutting parameters according to the clamp structure design, process the cutting with cutting equipment, monitor the accuracy in real time and adjust the parameters, and chamfer the edges of the cutting after processing to remove sharp edges.

[0052] Preferably, S4 specifically includes the following steps: S4.1 Clean the oil and impurities at the connection between the shell and the end cap, check the flatness and dimensional accuracy, and correct any deviations using grinding equipment to meet assembly requirements; S4.2 Select a suitable O-ring and place it into the preset sealing groove, ensuring no twisting or deformation, and apply special sealing grease to the surface of the O-ring; S4.3 Place the clamp on the connection and align it with the mounting hole, insert the bolt, and tighten it symmetrically and gradually with a torque wrench according to the preset torque to ensure uniform clamping force; S4.4 Select a suitable plug for the through-hole component, clean the inner surface of the mounting hole, apply sealant to the sealing surface of the plug, insert it into the hole, and control the tightening force to fix the plug.

[0053] Preferably, S5 specifically includes the following steps: S5.1 Connect the pressure-resistant housing to the vacuum pumping equipment and pressure gauge using a dedicated pipeline and ensure a seal. Check the operating status of each component to meet the testing requirements; S5.2 Start the vacuum pumping equipment to remove the gas inside the housing, monitor the pressure gauge in real time, and close the valve to maintain the vacuum state after reaching the preset vacuum level; S5.3 After closing the valve, start a timer and record the pressure gauge reading at regular intervals within the preset pressure holding time. If the vacuum level drops significantly, check and handle the leak point; S5.4 Compare the vacuum level before and after pressure holding. If the change is within the allowable range, the airtightness is deemed qualified. If it exceeds the standard, re-inspect and handle until it meets the standard.

[0054] like Figure 2As shown, a method for processing a pressure hull for an unmanned underwater vehicle is disclosed. This method is implemented through different units, including: a titanium alloy integral machined cylindrical hull unit, a titanium alloy integral machined cylindrical head unit, a titanium alloy integral machined clamp connection unit, an O-ring sealing unit, a through-hull plug assembly unit, and an airtightness and pressure testing unit. The titanium alloy integral machined cylindrical hull unit and the titanium alloy integral machined cylindrical head unit are fixedly connected by the titanium alloy integral machined clamp connection unit, and the O-ring seal is sealed. The sealing ring unit is located at the connection between the integral machined cylindrical shell unit and the integral machined cylindrical head unit of titanium alloy, and is used to seal between the two. The through-hole plug assembly unit is installed at the preset hole position of the integral machined cylindrical head unit of titanium alloy, and is used to seal the through-hole installation hole. The air tightness and pressure test unit is connected to the integral structure composed of the integral machined cylindrical shell unit and the integral machined cylindrical head unit of titanium alloy, and is used to perform air tightness test and pressure test on the integral structure.

[0055] Specific implementation method one: as follows Figure 3 , Figure 4 , Figure 5 , Figure 6 As shown, this embodiment illustrates a method for manufacturing a pressure hull for an unmanned underwater vehicle. The pressure hull is a cylindrical pressure chamber, comprising a cylindrical shell 2 and a cylindrical end cap. The end cap is provided with airtight holes and insert mounting holes. The manufacturing method includes the following steps:

[0056] Step 1: Machining the titanium alloy shell 2;

[0057] Step 2: Machining the titanium alloy end cap;

[0058] Step 3: Machining titanium alloy clamp 4;

[0059] Step 4: After sealing the shell 2 and the head with an O-ring, they are assembled and connected by clamps 4, including the assembly of the through-hole plug;

[0060] Step 5: Perform airtightness and pressure testing on the assembled pressure-resistant housing according to airtightness and pressure testing standards.

[0061] In this embodiment, components such as airtight holes, plug mounting holes, and through-hull plugs are conventional features on the pressure hulls of existing unmanned underwater vehicles and are not innovative aspects of this invention. This embodiment includes four types of pressure hulls: two for the battery compartment, one for the instrument compartment, one for the power distribution compartment, and two for the emergency safety electronics compartment. Each pressure hull is a rotating structure made of TC4 titanium alloy. The final assembly, airtightening, and pressurization steps are performed after the pressure hull assembly is complete.

[0062] Specific implementation method two: such as Figure 3 , Figure 4 , Figure 5 , Figure 6 As shown, this embodiment describes the process of machining the shell 2 in the first step. The shell is formed integrally using titanium alloy forged tubular or bar stock, and includes the following steps:

[0063] Step 1: Customize pipe or bar stock:

[0064] Step 2, Machining: Machin the inner and outer surfaces and lengths according to the machining requirements, and then drill holes;

[0065] Step 3, Cleaning: Clean the casing;

[0066] Step 4, Non-destructive testing: Perform radiographic non-destructive testing.

[0067] The machining requirements for step 2 are as follows: After the shell is machined, the thickness deviation of the shell is 0-+1mm at four positions spaced 90° apart on any cross section of the shell.

[0068] There are no abrupt changes on the outer surface of the shell, and the local dimensional deviation is ≤0.5mm;

[0069] The shell 2, end cap and clamp 4 are all machined into one piece, and there is no welding in the production process of the pressure-resistant shell.

[0070] Step 4, non-destructive testing, shall be conducted in accordance with the provisions of NB / T47013.2-2015 "Non-destructive testing of pressure equipment - Part 2: Radiographic testing", and the test results shall meet the Class I requirements of the standard.

[0071] The method for preparing the titanium alloy forged tubing used in processing the shell 2 in this embodiment is as follows:

[0072] Step 1: Powder metallurgy for tube blank preparation:

[0073] In the metallurgical step, titanium powder is used as raw material, and mixed with Al: 2.5%-4.5% and V: 5.5%-8.5%, and TC4 titanium alloy tube blank is prepared by powder metallurgy sintering method.

[0074] Step 2, Radial Forging:

[0075] The radial forging process includes: heating the TC4 titanium alloy tube blank to 50-120°C above the β phase transformation temperature, holding it at that temperature for 20-50 minutes, and performing a single-pass radial forging with a forging amount of less than 20% to obtain a primary forged tube; further heating the primary forged tube to 20-90°C below the β phase transformation temperature, holding it at that temperature for 20-50 minutes, and performing a second-pass radial forging with a forging amount of more than 40% to obtain an intermediate forged tube; further heating the intermediate forged tube to 20-80°C below the β phase transformation temperature, holding it at that temperature for 20-60 minutes, and performing a third-pass radial forging with a forging amount of more than 40% to obtain a TC4 titanium alloy tube.

[0076] In this embodiment, TC4 titanium alloy tubes are produced by powder metallurgy to form tube blanks and radial forging. The tube blanks are subjected to a two-stage radial forging process at high and low temperatures to produce seamless tubes with uniform deformation and high strength. This improves the uniformity of metal deformation during the process, ensures the dimensional uniformity of the titanium alloy tubes, and results in high surface quality.

[0077] The other components and connections are the same as in Specific Implementation Method 1.

[0078] Specific implementation method three: such as Figure 3 , Figure 4 , Figure 5 , Figure 6 As shown, this embodiment describes the process of machining the end cap in step two. The end cap is formed entirely from a titanium alloy sheet using machining, and includes the following steps:

[0079] Step 1: Customize the toppings:

[0080] Step 2, Machining: Machin the inner and outer surfaces and lengths according to the machining requirements; machine the connector mounting holes and make the holes;

[0081] Step 3, Cleaning: Clean the casing;

[0082] Step 4, Non-destructive testing: Perform radiographic non-destructive testing;

[0083] Step 5: Make the logo: Laser engraving logo.

[0084] The machining requirements for step 2 are as follows: After the shell is machined, the thickness deviation of the shell is 0-+1mm at four positions spaced 90° apart on any cross section of the shell.

[0085] There are no abrupt changes on the outer surface of the shell, and the local dimensional deviation is ≤0.5mm;

[0086] The shell 2, end cap and clamp 4 are all machined into one piece, and there is no welding in the production process of the pressure-resistant shell.

[0087] Step 4, non-destructive testing, shall be conducted in accordance with the provisions of NB / T47013.2-2015 "Non-destructive testing of pressure equipment - Part 2: Radiographic testing", and the test results shall meet the Class I requirements of the standard.

[0088] The other components and connections are the same as in Specific Implementation Method 1.

[0089] Specific implementation method four: such as Figure 3 , Figure 4 , Figure 5 , Figure 6 As shown, this embodiment is illustrated. In this embodiment, step three, machining the clamp 4, involves integrally machining a titanium alloy sheet, including the following steps:

[0090] Step 1, Material Cutting: Material cutting is carried out in the sheet metal workshop;

[0091] Step 2, Machining: Machin the inner and outer surfaces and height according to the machining requirements, then make holes, and finally make cuts;

[0092] Step 3, Cleaning: Clean the clamps.

[0093] The machining requirements for step 2 are as follows: After the shell is machined, the shell thickness deviation is 0 to +1 mm at four positions spaced 90° apart on any cross section of the shell.

[0094] There are no abrupt changes on the outer surface of the shell, and the local dimensional deviation is ≤0.5mm;

[0095] The shell 2, end cap and clamp 4 are all machined into one piece, and there is no welding in the production process of the pressure-resistant shell.

[0096] In this embodiment, the method for preparing the titanium alloy sheet used to process the clamp 4 includes the following steps:

[0097] Substrate preparation: Take TC4 titanium alloy blank plate, clean the surface dust, heat to 440-470℃, hold for 10 minutes for pretreatment to remove surface oxide scale, polish the surface of the blank plate, and finally clean with ethanol solution and blow dry to make the substrate.

[0098] Rolled-up preparation: Take several substrates, stack them in alignment, weld and fix one end of the substrate, place it on the lower cover plate for positioning, cover it with the upper cover plate, and seal the edges of the upper and lower cover plates with steel plates welded on the periphery. Two air inlets are symmetrically opened on both sides of the steel plate away from the welded end of the substrate to make the rolled-up.

[0099] First rolling: The heating furnace is preheated to 800-900℃. Argon gas is introduced through the gas filling port of the ladle and then the ladle is placed in the heating furnace and heated to 1000-1020℃. The holding time T is 14-16 minutes. After that, the ladle is taken out and bit into the substrate welding end for rolling. The rolling speed is 1.5-2 m / s. Two passes are rolled per heat. The first pass is longitudinal rolling, and the rolling deformation is controlled at 8%. The second pass is transverse rolling, and the rolling deformation is controlled at 5%.

[0100] Re-rolling: The process is the same as the first rolling process. Before each heating furnace preheating, argon gas of the same volume as the furnace chamber is introduced into the furnace. The re-rolling holding time is Tn = T - 2n, where n is the number of re-rolling times, until the thickness of each substrate is 0.4-0.6 mm. The rolling speed is 1.5-2 m / s. Each heating furnace is rolled in two passes. The first pass is longitudinal rolling, and the rolling deformation is controlled at 8%. The second pass is transverse rolling, and the rolling deformation is controlled at 5%.

[0101] Annealing: Take out the rolled ladle and air cool it to a surface temperature of 100-150℃. Separate it by ultrasonic vibration, take out the substrate, put it back into the heating furnace, heat it to 600-750℃, hold it for 8-10 minutes, and then anneal it isothermally to room temperature in the heating furnace.

[0102] Post-processing: The annealed substrate is placed in dilute sulfuric acid and the surface of the substrate is brushed with a wire brush. After rinsing, drying, oiling and storage are carried out to produce TC4 titanium alloy thin plates.

[0103] In a preferred embodiment, during the roll-up process, the positioning is specifically such that the substrate welding end is 5-10mm from the front end face of the lower cover plate, the opposite end of the substrate welding end is 20-30mm from the rear end face of the lower cover plate, and both sides of the substrate are 3-5mm from the two end faces of the lower cover plate.

[0104] In a preferred embodiment, during the first rolling and re-rolling processes, after the rolling ladle is placed in the heating furnace, the heating rate is 10-12℃ / min.

[0105] In a preferred embodiment, during the annealing process, the isothermal annealing cooling rate is 12-15°C / min.

[0106] In a preferred embodiment, the mass fraction of dilute sulfuric acid in the post-processing step is 10%.

[0107] In this embodiment, a multi-pass rolling process with small deformation is used to produce TC4 titanium alloy thin plates. Each pass involves two vertically reversed rolling passes. The deformation is controlled at 8% in the first pass and 5% in the second pass. By rationally designing the heating temperature, holding time, and rolling speed, the anisotropy of the plate is significantly reduced. During the preparation of the rolled ladle, one end of the substrate is welded and fixed to prevent slippage and misalignment during rolling. The resulting TC4 titanium alloy thin plates exhibit low inconsistency. Using the above-described preparation method, the clamp-type TC4 titanium alloy sheet is processed into a thin-walled structure with a minimum wall thickness of 3mm, achieving high dimensional tolerance accuracy for the parts.

[0108] The other components and connections are the same as in Specific Implementation Method 1.

[0109] Specific Implementation Method Five: Combining Figure 3 , Figure 4 , Figure 5 , Figure 6 This embodiment describes the airtightness standard for step five as follows:

[0110] 1. After the pressure-resistant housing is assembled, an airtightness test is performed by vacuum pressure holding. The gas inside the pressure-resistant housing is evacuated to a vacuum degree of 0.7, the gas valve is closed, and the vacuum degree inside the housing is observed through the pressure gauge. If there is no change in the vacuum degree after 15 minutes, the airtightness of the product is qualified.

[0111] 2. The internal airtightness test shall be conducted at a room temperature of 15℃-35℃.

[0112] The pressure testing standards for step five are as follows:

[0113] A hydrostatic pressure test was conducted on the airtight pressure-resistant shell. The test pressure was 18.75 MPa. The pressure was increased to 18.75 MPa using a step-by-step pressurization method and held for 2 hours. After the hydrostatic pressure test, the pressure-resistant shell showed no deformation or leakage.

[0114] The other components and connections are the same as in Specific Implementation Method 1.

[0115] Specific Implementation Method Six: Combination Figure 3 , Figure 4 , Figure 5 , Figure 6 This embodiment describes the airtightness standard for step five as follows:

[0116] 1. After the pressure-resistant housing is assembled, an airtightness test is performed by vacuum pressure holding. The gas inside the pressure-resistant housing is evacuated to a vacuum degree of 0.7, the gas valve is closed, and the vacuum degree inside the housing is observed through a pressure gauge. If there is no change in the vacuum degree after 10-20 minutes, the airtightness of the product is qualified.

[0117] 2. The internal airtightness test shall be conducted at room temperature of 20℃-40℃.

[0118] The pressure testing standards for step five are as follows:

[0119] A hydrostatic pressure test was conducted on the airtight pressure-resistant shell. The test pressure was 18.75 MPa. The pressure was increased to 18.75 MPa using a step-by-step pressurization method and held for 1-4 hours. After the hydrostatic pressure test, the pressure-resistant shell showed no deformation or leakage.

[0120] The other components and connections are the same as in Specific Implementation Method 1.

[0121] Specific implementation method seven: such as Figure 3 , Figure 4 , Figure 5 , Figure 6 As shown, this embodiment is described. In this embodiment, the airtightness standard for step five is as follows: 1. After the pressure-resistant housing is assembled, the airtightness is checked by vacuum pressure holding. The gas inside the pressure-resistant housing is evacuated to a vacuum degree of 0.7, the air valve is closed, and the vacuum degree inside the housing is observed by the pressure gauge. If there is no change in the vacuum degree for 10 minutes, the airtightness of the product is qualified.

[0122] 2. The internal airtightness test was conducted at room temperature (20℃).

[0123] The pressure testing standards for step five are as follows:

[0124] A hydrostatic pressure test was conducted on the airtight pressure-resistant shell. The test pressure was 18.75 MPa. The pressure was increased to 18.75 MPa using a step-by-step pressurization method and held for 1 hour. After the hydrostatic pressure test, the pressure-resistant shell showed no deformation or leakage.

[0125] In this embodiment, the airtightness standard for step five is as follows: 1. After the pressure-resistant housing is assembled, the airtightness is checked by vacuum pressure holding. The gas inside the pressure-resistant housing is evacuated to a vacuum degree of 0.7, the gas valve is closed, and the vacuum degree inside the housing is observed by the pressure gauge. If there is no change in the vacuum degree for 20 minutes, the airtightness of the product is qualified.

[0126] 2. The internal airtightness test was conducted at room temperature (40℃).

[0127] The pressure testing standards for step five are as follows:

[0128] A hydrostatic pressure test was conducted on the airtight pressure-resistant shell. The test pressure was 18.75 MPa. The pressure was increased to 18.75 MPa using a step-by-step pressurization method and held for 4 hours. After the hydrostatic pressure test, the pressure-resistant shell showed no deformation or leakage.

[0129] The other components and connections are the same as in Specific Implementation Method 1.

[0130] Specific implementation method eight: Combination Figure 3 , Figure 4 , Figure 5 , Figure 6 This embodiment describes four types of pressure-resistant housings: two sets of pressure-resistant housings for the battery compartment, one set of pressure-resistant housings for the instrument compartment, one set of pressure-resistant housings for the power distribution compartment, and two sets of pressure-resistant housings for the emergency safety electronic compartment. All pressure-resistant housings are made of TC4 material.

[0131] The pressure-resistant shell of the battery compartment consists of a front end cap 1, a shell 2 and a rear end cap 3. The inner surfaces of the left and right ends of the shell 2 are sealing surfaces. Reinforcing ribs 201 are evenly distributed inside the shell 2. Threaded holes 202 are provided in the radial and axial directions of the shell 2.

[0132] The pressure-resistant housing of the instrument compartment consists of a front end cap 1, a housing 2 and a rear end cap 3. The inner surfaces of the left and right ends of the housing 2 are sealing surfaces. The housing 2 is equipped with reinforcing ribs 201 inside, and threaded holes 202 are provided in the radial and axial directions of the housing 2.

[0133] The power distribution compartment pressure shell consists of a front end cap 1, a shell 2 and a rear end cap 3. The inner surfaces of the left and right ends of the shell 2 are sealing surfaces. There are no reinforcing ribs inside the shell 2. Threaded holes 202 are provided radially on the outer surface of the shell 2.

[0134] The pressure-resistant shell of the emergency safety electronic compartment consists of shell 2 and end cap 5. One end of the emergency safety electronic compartment is closed and the other end is open. The inner surface of the open end is a sealing surface. There are no reinforcing ribs inside or outside the shell 2.

[0135] The other components and connections are the same as in Specific Implementation Method 1.

[0136] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "set," "install," "connect," "link," and "fix" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal communication between two components. Those skilled in the art will understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0137] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various equivalent changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A method for processing a pressure hull for an unmanned underwater vehicle, characterized in that, The process includes the following steps: S1. Machining the titanium alloy shell: The shell is integrally machined from titanium alloy forged tubing or bar stock. First, a tubing or bar stock meeting the dimensional requirements is customized. Then, the inner surface, outer surface, and length of the tubing or bar stock are machined according to preset machining parameters. Holes are then drilled at preset positions on the shell. After machining, the shell is cleaned. Finally, non-destructive testing of the shell is performed using X-ray inspection. S2. Machining the titanium alloy end cap: The end cap is integrally machined from titanium alloy disc stock. First, a disc stock meeting the material and dimensional requirements is customized. Then, the inner surface, outer surface, and length of the disc stock are machined according to preset machining parameters. Simultaneously, connector mounting holes are machined and drilled at preset positions. After machining, the end cap is cleaned. S1. Non-destructive testing of the head is performed using X-ray inspection technology, and finally, markings are made on the surface of the head using laser engraving. S2. Processing titanium alloy clamps: The titanium alloy sheet is integrally machined. First, the titanium alloy sheet is cut into pre-set dimensions in the sheet metal workshop. Then, the inner surface, outer surface, and height of the cut sheet are machined according to pre-set machining parameters. Then, holes are made at pre-set positions on the sheet, and finally, cuts are made at designated positions on the sheet. After machining, the clamps are cleaned. S3. Assembling and connecting the shell and the head: O-rings are set at the connection between the shell and the head for sealing. The sealed shell and head are assembled and fixed using clamps. At the same time, the assembly of the through-hole plug is completed. When machining titanium alloy shells in S1, the shell thickness deviation control model is as follows: ,in, This indicates the shell thickness deviation value. Indicates the actual machined thickness of the shell. Indicates the standard thickness of the casing. Indicates the temperature effect coefficient. This indicates the amount of temperature change during the processing. This represents the coefficient of influence of processing speed. This represents the machining speed; simultaneously, the calculation model for the dimensional deviation of the outer surface of the shell is: ,in, This indicates the dimensional deviation of the outer surface of the casing. This indicates the actual dimension of the outer surface of the shell in the x-direction. This indicates the standard dimension of the outer surface of the housing in the x-direction. This indicates the actual dimension of the outer surface of the shell in the y-direction. This indicates the standard dimension of the outer surface of the housing in the y-direction. This represents the influence coefficient of processing time. This indicates the machining time.

2. The method for processing a pressure hull for an unmanned underwater vehicle according to claim 1, characterized in that, The method also includes: S5, performing an airtightness test on the assembled pressure-resistant housing, using a vacuum pressure holding method to evacuate the gas inside the pressure-resistant housing to a preset vacuum level, closing the air valve and monitoring the change in the vacuum level inside the housing through a pressure gauge to determine whether the airtightness meets the standard; S6, performing a pressure test on the pressure-resistant housing that has passed the airtightness test, using a hydrostatic pressure test, pressurizing according to a preset test pressure through a step-by-step pressurization method, holding the pressure for a preset time, and detecting whether the pressure-resistant housing has deformation or leakage.

3. The method for processing a pressure hull for an unmanned underwater vehicle according to claim 1, characterized in that, When machining titanium alloy heads in S2, the calculation model for the positional accuracy of the head connector mounting hole seat is as follows: ,in, This indicates the positional accuracy of the hole seat. This indicates the actual coordinates of the hole seat in the x-direction. This represents the standard coordinate of the hole seat in the x-direction. This indicates the actual coordinates of the hole seat in the y-direction. This indicates the standard coordinates of the hole seat in the y-direction. This represents the actual coordinates of the hole seat in the z-direction. This represents the standard coordinates of the hole seat in the z-direction. Indicates the influence coefficient of processing force. This represents the force applied during the machining process; and the laser marking clarity evaluation model is as follows: ,in, This indicates the signage clarity assessment value. Indicates the reference light intensity for laser marking. This indicates the actual light intensity during laser engraving. Indicates the influence coefficient of engraving depth. This indicates the actual depth of the laser engraving.

4. The method for processing a pressure hull for an unmanned underwater vehicle according to claim 1, characterized in that, When machining titanium alloy clamps in S3, the clamp cut dimension accuracy control model is as follows: ,in, This indicates the deviation value of the clamp cut size. This indicates the actual size of the clamp cut. This indicates the standard dimensions of the clamp cut. This represents the coefficient of influence of changes in processing speed. Indicates the change in processing speed. This represents the coefficient of influence of changes in processing force. This represents the change in processing force; simultaneously, the calculation model for the inner surface roughness of the clamp is: ,in, This indicates the surface roughness value of the clamp's inner surface. This indicates the surface roughness of the clamp substrate. This represents the influence coefficient of polishing time. Indicates the polishing process time. This indicates the influence coefficient of polishing pressure. This indicates the pressure applied during the polishing process.

5. The method for processing a pressure hull for an unmanned underwater vehicle according to claim 1, characterized in that, When assembling and connecting in S4, the O-ring sealing performance evaluation model is as follows: ,in, This indicates the sealing performance evaluation value. This indicates the maximum permissible pressure difference of the sealing ring. This indicates the actual pressure difference between the sealing rings. This indicates the influence coefficient of assembly temperature. This indicates the amount of temperature change during the assembly process. This indicates the influence coefficient of assembly pressure. This represents the clamping force during the assembly process; and the calculation model for the tightness of the clamp assembly is as follows: ,in, This indicates the tightness value of the clamp assembly. This indicates the actual tightening force of the clamp. This indicates the minimum allowable tightening force of the clamp. This indicates the maximum allowable tightening force of the clamp. This represents the influence coefficient of assembly time. This indicates the change in assembly time. This represents the coefficient affecting assembly speed. This indicates the change in assembly speed.

6. A method for processing a pressure hull for an unmanned underwater vehicle according to claim 2, characterized in that, When performing airtightness testing in S5, the calculation model for the rate of change of vacuum degree is as follows: ,in, Indicates the rate of change of vacuum degree. Indicates the vacuum level at the initial moment of detection. Indicates the vacuum level at the end of the test. Indicates the start time of the detection. Indicates the end time of the test. This represents the initial vacuum level influence coefficient. This represents the initial vacuum level. This indicates the influence coefficient of the detection temperature. This represents the temperature change during the testing process; simultaneously, the threshold model for determining airtightness is: ,in, This indicates the threshold for determining whether airtightness is acceptable. Indicates the basic judgment threshold. This represents the influence coefficient of pressure holding time. Indicates the holding time. Indicates the environmental pressure influence coefficient. This indicates the environmental pressure being tested.

7. The method for processing a pressure hull for an unmanned underwater vehicle according to claim 1, characterized in that, S3 specifically includes the following steps: S3.1 In the sheet metal workshop, according to the design dimensions and shape parameters of the clamp, mark the outline of the titanium alloy sheet and cut along the outline using special equipment, controlling the cutting speed and depth to avoid deformation or defects; S3.2 Adjust the machine tool speed, feed rate and cutting depth according to the preset machining parameters, first rough machine the outer surface of the sheet to remove excess material, and then finish machine to the design standard. Machine the inner surface in the same way to ensure coaxiality; S3.3 Determine the position, number and size of the holes according to the clamp assembly requirements, drill the holes with special equipment, mark the positioning before drilling, control the drilling speed and pressure, and grind the inner surface of the holes after completion; S3.4 Determine the cutting parameters according to the clamp structure design, process the cutting with cutting equipment, monitor the accuracy in real time and adjust the parameters, and chamfer the edges of the cutting after processing to remove sharp corners.

8. The method for processing a pressure hull for an unmanned underwater vehicle according to claim 1, characterized in that, S4 specifically includes the following steps: S4.1 Clean the oil and impurities at the connection between the shell and the end cap, check the flatness and dimensional accuracy. If they exceed the standards, use grinding equipment to correct them to meet the assembly requirements; S4.2 Select a suitable O-ring and place it into the preset sealing groove, ensuring that there is no twisting or deformation. Apply special sealing grease to the surface of the sealing ring; S4.3 Place the clamp on the connection part and align it with the mounting hole. Insert the bolt and use a torque wrench to tighten it symmetrically and gradually according to the preset torque to ensure uniform clamping force. S4.4 Select a suitable plug for the compartment, clean the inner surface of the mounting hole, apply sealant to the sealing surface of the plug, insert it into the hole, and control the tightening force to fix the plug.

9. A method for processing a pressure hull for an unmanned underwater vehicle according to claim 2, characterized in that, S5 specifically includes the following steps: S5.1 Connect the pressure-resistant housing to the vacuum pumping equipment and pressure gauge using a dedicated pipeline and ensure a seal. Check the operating status of each component to ensure it meets the testing requirements. S5.2 Start the vacuum pumping equipment to remove the gas inside the housing, monitor the pressure gauge in real time, and close the valve to maintain the vacuum state after reaching the preset vacuum level. S5.3 After closing the valve, start a timer and record the pressure gauge reading at regular intervals within the preset pressure holding time. If the vacuum level drops significantly, check and handle the leak point. S5.4 Compare the vacuum level before and after pressure holding. If the change is within the allowable range, the airtightness is deemed qualified. If it exceeds the standard, re-inspect and handle until it meets the standard.

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