Processing method and system for composite sealing structure of power valve of carrier rocket

Abstract

The invention provides a processing method and system for a composite sealing structure of a power valve of a carrier rocket. The processing method comprises the following steps: processing a valve clack metal boss and an annular sealing groove on the end surface of a valve clack metal matrix; an annular non-metal sealing ring is machined, end face turning machining is conducted, then turning machining is conducted on a step structure of the annular non-metal sealing ring, and a step-shaped non-metal sealing piece is formed; the step-shaped non-metal sealing piece is pressed into the annular sealing groove, rolling machining is conducted on the valve clack metal boss through a hobbing cutter structure, the valve clack metal boss is turned and deformed towards the interior of the annular sealing groove step by step, the step-shaped non-metal sealing piece is wrapped, and the valve clack sealing structure reliable in sealing is formed. According to the method, the wrapping reliability of the metal boss on the sealing piece after the metal boss is turned up is guaranteed through specific technological parameters, the situation that the metal boss is broken along the root or rolled and thinned is avoided, effective and continuous pressing force on the sealing piece is formed, the possibility of blow-by of the valve clack is reduced, and the sealing reliability and quality stability of the valve clack are improved.

Description

Technical Field

[0001] This invention relates to the field of metal plate processing or treatment technology with minimal cutting, specifically to a processing method and system for a composite sealing structure of a launch vehicle power valve. Background Technology

[0002] Power valves are a key component of the pressurization and delivery system of launch vehicles, primarily used in the pressurization and delivery pipelines for rocket propellants. The sealing performance of these valves directly affects the safe and stable operation of the pressurization and delivery system. For rocket power valves, to ensure sealing performance, the sealing valve disc is typically a metal / non-metal composite sealing structure. This is achieved by creating an annular sealing groove in the metal substrate of the valve disc and then pressing a non-metallic sealing element into the groove, using an interference fit to achieve relative fixation between the metal substrate and the non-metallic sealing element. However, the interference fit is significantly affected by material properties and the amount of interference, and there is a risk of loosening during significant temperature changes or valve vibration, resulting in insufficient stability of the valve disc's sealing performance. Currently, techniques such as non-metallic hot pressing or interfacial bonding are used to connect the sealing element to the metal substrate; however, these techniques are only applicable to specific non-metallic materials. A considerable number of valve discs still rely on mechanical connections for their non-metallic / metallic components. Therefore, a processing technology for the composite sealing structure of power valves is needed to achieve a highly reliable mechanical connection between the non-metallic and metallic components, ensuring the sealing performance of the valve disc. Summary of the Invention

[0003] To address the shortcomings of existing technologies, the purpose of this invention is to provide a processing method and system for a composite sealing structure of a launch vehicle power valve.

[0004] The processing method of the composite sealing structure of the launch vehicle power valve provided by the present invention includes: Step S1: Precision machining of valve disc metal substrate: A valve disc metal boss and an annular sealing groove are integrally machined on the end face of the valve disc metal substrate; wherein, the height and thickness of the valve disc metal boss are precisely machined to 0.5mm; Step S2: Precision machining and process verification of stepped non-metallic seals: Step S2.1: Machining the annular non-metallic sealing ring involves turning its end face to ensure that the end face in contact with the bottom of the annular sealing groove has a flatness of ≤0.01mm and a surface roughness of Ra0.8. Step S2.2: The annular non-metallic sealing ring is machined to form a stepped structure, resulting in a stepped non-metallic seal; the design dimensions of the stepped non-metallic seal satisfy the following: its inner diameter is interference-fitted with the minor diameter of the annular sealing groove, and its outer diameter is clearance-fitted with the major diameter of the annular sealing groove. Step S2.3: After processing, use a special plug gauge to verify the process of the stepped non-metallic seal: insert the plug gauge into its inner hole and check whether its outer diameter after simulated expansion is accurately greater than the major diameter of the annular sealing groove by 0.01mm to 0.02mm. Step S3: Composite Assembly and Metal Encapsulation Forming: Step S3.1: Press the stepped non-metallic seal into the annular sealing groove, and make the height of the stepped non-metallic seal lower than the opening of the annular sealing groove, with its stepped end face tightly against the side wall of the valve disc metal boss; during the pressing process, use a press and maintain the pressing state for 10 minutes. Step S3.2: The valve disc metal boss is rolled using a hobbing cutter. By controlling the machine tool spindle speed, hobbing feed speed and tool offset, the top of the valve disc metal boss undergoes plastic folding deformation inward, and the folding angle is greater than 90°, thereby forming a continuous metal flange that wraps around the upper part of the stepped non-metallic seal, and finally forming a composite sealing structure.

[0005] Preferably, the cutting head of the hobbing cutter structure is a circular hob with a tapered surface. The hob is mounted on a rotating shaft and rotates freely around the shaft, which is fixed to the tool holder.

[0006] Preferably, the machine tool speed is 350 r / min, the hob cutter feed rate is 0.45 mm / r, the hob cutter principal cutting edge angle is 105°, and the hob tip offset relative to the root of the valve disc metal boss is 0.01 mm to 0.1 mm.

[0007] Preferably, the outer side of the valve disc metal substrate has a thin boss structure with a thickness of 0.25mm to 0.9mm; the step width of the stepped non-metallic seal is 0.3mm to 0.4mm greater than the height of the valve disc metal boss.

[0008] Preferably, the interference fit between the inner ring of the stepped non-metallic seal and the inner ring of the annular sealing groove is 0.01mm~0.1mm; the stepped non-metallic seal and the outer ring of the annular sealing groove are fitted with a clearance fit, and the clearance is 0.01mm~0.05mm.

[0009] The processing system for the composite sealing structure of a launch vehicle power valve according to the present invention includes: Module M1: Precision machining of valve disc metal substrate: A valve disc metal boss and an annular sealing groove are integrally machined on the end face of the valve disc metal substrate; wherein, the height and thickness of the valve disc metal boss are precisely machined to 0.5mm; Module M2: Precision machining and process verification of stepped non-metallic seals: Module M2.1: Machining annular non-metallic sealing rings by turning their end faces to ensure that the end face in contact with the bottom of the annular sealing groove has a flatness of ≤0.01mm and a surface roughness of Ra0.8; Module M2.2: The annular non-metallic sealing ring is machined to form a stepped structure, resulting in a stepped non-metallic seal; the design dimensions of the stepped non-metallic seal satisfy the following: its inner diameter is interference-fitted with the minor diameter of the annular sealing groove, and its outer diameter is clearance-fitted with the major diameter of the annular sealing groove. Module M2.3: After machining, use a special plug gauge to verify the process of the stepped non-metallic seal: insert the plug gauge into its inner hole and check whether its outer diameter after simulated expansion is accurately greater than the major diameter of the annular sealing groove by 0.01mm to 0.02mm. Module M3: Composite Assembly and Metal Encapsulation Forming Module M3.1: Press the stepped non-metallic seal into the annular sealing groove, ensuring that the height of the stepped non-metallic seal is lower than the opening of the annular sealing groove, with its stepped end face tightly against the side wall of the valve disc metal boss; during the pressing process, use a press and maintain the pressing state for 10 minutes. Module M3.2: The valve disc metal boss is rolled using a hobbing cutter. By controlling the machine tool spindle speed, hobbing feed speed and tool offset, the top of the valve disc metal boss undergoes plastic folding deformation inward, and the folding angle is greater than 90°, thereby forming a continuous metal flange that wraps around the upper part of the stepped non-metallic seal, ultimately forming a composite sealing structure.

[0010] Preferably, the cutting head of the hobbing cutter structure is a circular hob with a tapered surface. The hob is mounted on a rotating shaft and rotates freely around the shaft, which is fixed to the tool holder.

[0011] Preferably, the machine tool speed is 350 r / min, the hob cutter feed rate is 0.45 mm / r, the hob cutter principal cutting edge angle is 105°, and the hob tip offset relative to the root of the valve disc metal boss is 0.01 mm to 0.1 mm.

[0012] Preferably, the outer side of the valve disc metal substrate has a thin boss structure with a thickness of 0.25mm to 0.9mm; the step width of the stepped non-metallic seal is 0.3mm to 0.4mm greater than the height of the valve disc metal boss.

[0013] Preferably, the interference fit between the inner ring of the stepped non-metallic seal and the inner ring of the annular sealing groove is 0.01mm~0.1mm; the stepped non-metallic seal and the outer ring of the annular sealing groove are fitted with a clearance fit, and the clearance is 0.01mm~0.05mm.

[0014] Compared with the prior art, the present invention has the following beneficial effects: This invention achieves the rolling of a metal boss of a specific thickness on the side of the valve disc metal substrate by using a hobbing cutter, thereby wrapping and fixing the stepped non-metallic seal. Specific process parameters ensure the reliability of the metal boss's wrapping of the seal after rolling, preventing the metal boss from breaking along its root or thinning due to rolling, forming an effective and continuous clamping force on the seal, reducing the possibility of valve disc leakage, and improving the reliability and quality stability of the valve disc seal. Attached Figure Description

[0015] Other features, objects, and advantages of the present invention will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings: Figure 1 This is a schematic diagram illustrating the manufacturing process of a composite sealing structure for valve discs. Figure 2 This is a schematic diagram of the hobbing cutter structure.

[0016] In the diagram: 1. Metal substrate; 2. Non-metallic sealing ring; 3. Valve disc boss; 4. Hob; 5. Tool holder; 6. Rotary shaft. Detailed Implementation

[0017] The present invention will now be described in detail with reference to specific embodiments. These embodiments will help those skilled in the art to further understand the present invention, but do not limit the invention in any way. It should be noted that those skilled in the art can make several changes and improvements without departing from the concept of the present invention. These all fall within the protection scope of the present invention.

[0018] Example 1 like Figure 1 As shown, the valve disc involved in this invention is a composite structure of metal and non-metal materials, and the whole is a rotating part. First, the metal matrix material of the valve disc is aluminum alloy (5A06). 5A06 material has the following characteristics: 1) Medium plasticity, cold rolling easily causes work hardening, and parameters need to be controlled to avoid boss breakage (thickness is only 0.5mm, weak resistance to deformation); 2) Strength: tensile strength is about 310MPa, and pressure and deformation need to be balanced during rolling to prevent excessive extrusion that could cause deformation of the sealing groove.

[0019] This invention provides a highly reliable composite valve disc sealing structure and its precision manufacturing process, which solves the technical problems of existing valve disc sealing structures under high pressure, high frequency or severe temperature difference conditions, such as sealing stress relaxation, interface micro-leakage and non-metallic ring detachment caused by the difference in thermal expansion coefficients of metal and non-metal materials.

[0020] To achieve the above objectives, the innovation of this invention mainly lies in the collaborative design of the sealing structure, the specific combination of key process parameters, and the integrated application of specialized processing methods. The specific steps are as follows: 1. Precision forming and differentiated fit design of the matrix: A valve disc boss 3 and an annular sealing groove are integrally machined on the end face of the metal substrate 1. The height and thickness of the valve disc boss 3 are optimized and precisely controlled to 0.5mm. This size is not a conventional choice in the field, but rather provides precise material volume reserve for subsequent rolling and folding at a specific angle, ensuring the controllability and consistency of deformation after folding.

[0021] The innovative design of the annular sealing groove lies in its differentiated composite fit with the non-metallic sealing ring 2: the inner diameter of the non-metallic sealing ring 2 and the small diameter of the sealing groove are interference-fitted to achieve initial positioning and radial pre-tightening; while its outer diameter and the large diameter of the sealing groove are precisely clearance-fitted. This "tight inside, loose outside" fit design is one of the key features of this invention, and its purpose is to: a) reserve radial expansion space for the non-metallic material under pressure and temperature changes, preventing the sealing ring from breaking or the matrix from plastic deformation due to the accumulation of thermal stress; b) ensure that the sealing pressure mainly acts on the contact interface between the axial end face of the sealing ring and the bottom of the groove, optimizing the distribution of sealing stress.

[0022] 2. Precision machining and process verification of non-metallic sealing rings: When machining the non-metallic sealing ring 2, the end face that contacts the bottom of the groove must have a flatness ≤0.01mm and a surface roughness of Ra0.8 to ensure a tight fit with the metal groove bottom without microscopic gaps after pressing, eliminating interface leakage channels. After machining the stepped structure, a special plug gauge is required for process inspection: insert the plug gauge into the inner hole of the sealing ring to simulate its expansion under working conditions, and check whether its outer diameter expansion is precisely controlled within the range of 0.01mm~0.02mm larger than the large diameter of the sealing groove. This step is a key process control point to ensure the accuracy and consistency of the "clearance fit". This specific expansion range has been experimentally verified to optimally balance the requirements of anti-loosening and stress release.

[0023] 3. Step-by-step composite assembly and stress stabilization process: When pressing the non-metallic sealing ring 2 into the base sealing groove, a special press is used and the pressing state is maintained for 10 minutes. This specific pressure holding time is not a routine operation. Its purpose is to allow the non-metallic material to undergo controllable creep, fully fill the micro-unevenness, and allow the internal stress to be initially relaxed and stabilized, forming a stable pre-tightened sealing interface.

[0024] 4. Innovative metal-wrapped fixing process: After assembly, this invention uses a custom-designed hobbing cutter (such as...). Figure 2As shown, the valve disc boss 3 is subjected to directional rolling and folding processing. By strictly controlling a specific combination of parameters such as the machine tool spindle speed, hob feed speed, and the offset of the tool relative to the boss, the top of the valve disc boss 3 is folded inward by more than 90° (preferably 92°~95°), thereby forming a continuous, plastically deformable metal wrapping edge on the upper part of the step of the non-metallic sealing ring 2.

[0025] This "large-angle inward folding and wrapping" structure is the core innovation of this invention: a) It mechanically locks the non-metallic sealing ring, completely preventing it from axially dislodging; b) The folded metal applies a continuous radial clamping force to the sealing ring, which, together with the preload generated by the initial interference fit and the working medium pressure, constitutes a multi-level synergistic sealing force system; c) This wrapping structure allows the non-metallic sealing ring to have a certain elastic deformation space in the radial direction, but the axial displacement is strictly limited, achieving the excellent effect of "hard axial constraint and soft radial compensation".

[0026] Because the protrusions of this structure are folded inward at a large angle, micro-cracks are prone to appear during the folding process. These cracks can be removed through subsequent anodizing.

[0027] The process of end face turning is as follows: Clamping the workpiece: Place the sealing ring in the lathe chuck or special fixture to ensure accurate positioning; clamp the sealing ring with appropriate force to ensure that it does not shift during machining. Setting parameters: Set an appropriate spindle speed based on material hardness and tool material; set a reasonable cutting feed rate to ensure machining efficiency and surface quality; determine the depth of cut for each pass based on the required machining allowance; Machining process: First, rough turning is performed to remove most of the excess material and achieve near-final dimensions. After rough turning, finish turning is performed to ensure that the dimensional accuracy and surface roughness of the sealing ring end face meet the requirements. If necessary, a slight chamfer can be applied to the edge of the end face to reduce stress concentration. Inspection: Use tools such as vernier calipers and micrometers to measure key dimensions such as the diameter and thickness of the sealing ring; check the end face for defects such as scratches and burrs, and if necessary, use a surface roughness tester to measure the surface roughness.

[0028] The cutting head of the hob tool structure is a circular hob 4 with a tapered surface. The hob 4 is mounted on a rotating shaft 6 and can rotate freely around the rotating shaft 6. The rotating shaft 6 is fixed on the tool holder 5.

[0029] This structure, due to the large inward folding angle of the metal substrate boss, is prone to micro-cracks at the outer root of the boss during the flanging process, leading to product scrap. Through extensive testing and practice, the factors affecting the flanging quality of this sealing structure have been identified: 1) Metal material; 2) Surface roughness of the metal substrate sealing groove; 3) Gap between the inner ring of the metal substrate sealing groove and the non-metallic sealing ring hole, and interference fit between the outer ring of the metal substrate sealing groove and the outer circle of the non-metallic sealing ring; 4) Spindle speed; 5) Tool feed rate; 6) Principal cutting edge angle of the roller tool; 7) Roller tool tip offset. Factors 1) to 3) have already been described above. The probability of cracks occurring during flanging has been reduced to less than 10%.

[0030] To produce a qualified valve disc, the criteria are as follows: 1) The boss on the valve disc base should completely cover the non-metallic full-step surface after being folded; 2) After folding, the folded part of the metal base and the metal surface should not have defects such as cracking, wrinkling, or roughening; 3) After the valve disc assembly is folded, the non-metallic surface is finished, but a 0.5mm allowance is required. Then, a "gas leakage test" is performed. If there is no gas leakage on any surface, the valve disc assembly is deemed to be qualified after folding. Finally, the non-metallic surface is finished to obtain a qualified product.

[0031] To ensure that the non-metallic stepped surface is completely covered after the valve disc is flanged, and that there are no defects such as cracks, wrinkles, or roughening at the folded part of the metal substrate and on the metal surface, the processing parameters need to be verified through testing. Based on the common characteristics of the flanging process and the properties of the valve disc material, the initial parameter range is preset as follows:

[0032] Single-factor variable experimental design 1. Experimental Design Principles Only one parameter is changed each time, while the other three are fixed at the baseline value (the midpoint of the interval). Five gradient levels were set for each parameter, and the experiment was repeated three times for each level. The average value was then used for analysis.

[0033] 2. Detailed Procedures for Parameterized Experiments (1) Experiment on the effect of spindle speed Fixed reference values: f = 0.45 mm / r, κr = 105°, Δ = 0.05; Speed ​​gradient: 200→300→400→500→600rpm; Key observations: Whether vertical cracks appear at the root of the metal substrate flange when the rotation speed is >500 rpm; whether wrinkles appear on the folded surface of the metal substrate when the rotation speed is <200 rpm.

[0034] (2) Experiment on the effect of tool feed rate Fixed reference values: n=400rpm, κr=75°, Δ=0.05; Feed rate gradient: 0.35→0.40→0.45→0.50→0.55mm / r; Key observation: Correlation between feed rate and thickness reduction rate.

[0035] (3) Experiment on the influence of the principal deflection angle of the roller Fixed reference values: n=400rpm, f=0.5mm / r, Δ=0.05; Angular gradient: 60°→75°→90°→105°→120° Key observations: whether the verticality of the vertical edge is reduced below 60°; whether the thickness unevenness is aggravated above 120°.

[0036] (4) The effect of tool tip offset on the experiment Reference fixed values: n=400rpm, f=0.5mm / r, κr=105°; Offset gradient: 0.01→0.03→0.05→0.07→0.09 Key observations: Does insufficient offset lead to "breakage at the fold"? Does excessive offset lead to "insufficient fold angle, unable to fully cover the non-metallic step surface"?

[0037] 3. Defect-oriented parameter optimization 3.1 Typical Defects and Parameter Adjustment Strategies

[0038] 3.2 Optimization of verification experiments Three sets of optimized parameter combinations were selected for batch trial production (20 pieces per set), and the pass rate was calculated. The final parameters must meet the following requirements: pass rate ≥ 90% and tool life ≥ 500 pieces.

[0039] 4. Setting process and effects of key rolling process parameters A set of optimal coordination parameters was obtained through theoretical calculations and experimental verification. The specific setting process and technical principles are as follows: 4.1 Specific process and technical considerations for parameter setting: a) Coordinated setting of machine tool speed (350 r / min) and feed rate (0.45 mm / r): Objective: To achieve efficient and stable progressive folding forming while ensuring sufficient plastic flow of metal and avoiding cutting or tearing.

[0040] Process: Excessive rotational speed (e.g., >500 r / min) results in insufficient contact time between the tool and material, leading to high impact force and making thin-walled bosses (0.5 mm thick) prone to chattering or fatigue cracks. Insufficient rotational speed (e.g., <200 r / min) results in low production efficiency and is prone to localized overheating of the material due to heat accumulation, altering its properties. Excessive feed rate can cause material accumulation and discontinuous folding; insufficient feed rate leads to low processing efficiency and may damage the surface of non-metallic sealing rings due to excessive rolling.

[0041] Creative Setup: Through multiple rounds of process testing, it was discovered that fixing the rotation speed at 350 r / min and matching it with a feed rate of 0.45 mm / r produces the optimal "rolling-extrusion" effect within the specific dimensions of this invention (0.5 mm boss height / thickness). This combination allows the metal material to bend inward in a near-uniform plastic rheological manner under the action of the tool, ensuring the continuity of deformation and providing a controllable deformation basis for the next step of forming a final angle greater than 90°.

[0042] b) Creative design of the hobbing cutter's principal cutting edge angle (105°): Objective: To guide the metal material to flow primarily axially (inward), rather than being cut or pushed away radially, while providing the necessary strength to the tool tip.

[0043] Process: The principal cutting edge angle of a conventional lathe tool is usually 90° or less. If a 90° principal cutting edge angle is used, the lateral force on the tool is relatively large, which can easily cause radial instability and deformation of a 0.5mm thick boss. If the angle is too large (such as close to 120°), it is not conducive to guiding the inward folding.

[0044] Creative Design: The present invention specifically designs the main deflection angle to be 105°. This specific angle produces two key effects: (1) it generates a component force pointing towards the center of the valve disc, actively guiding the metal flow to bend inward and downward (towards the sealing ring), rather than simply being crushed; (2) the blade tip structure that matches the 105° angle can form a "guide surface" when it contacts the boss, pre-bending the metal and creating the initial conditions for the subsequent ultimate folding of more than 90°. This is one of the key structural innovations for achieving large-angle wrapping.

[0045] c) Precise control of hobbing cutter tip offset (0.05mm): Objective: To precisely control the position of the rolling start point and the folding root, ensuring that the starting point of the folded package is accurate and the shape is consistent, without damaging the non-metallic sealing ring.

[0046] Process: Rolling the boss directly with the blade tip (offset of 0) will cause excessive stress concentration, making it very easy to generate micro-cracks at the root. If the offset is too large (e.g., >0.1mm), the rolling point will be too high, which may cause the upper part of the boss to be curled up too early and fail to effectively wrap the sealing ring.

[0047] Creative Setting: The present invention creatively sets the blade tip at a precise offset of 0.05mm from the root of the valve disc metal boss towards the end face. This means that the initial point of action of the rolling is located on the side wall of the boss near the root but not the weakest point. This setting brings unexpected beneficial effects: (1) a small "deformation guide zone" is formed above the root of the boss, making the bending radius of the subsequent folding smaller and easier to break through the 90° limit; (2) stress concentration at the root is avoided, fundamentally preventing the generation of rolling cracks; (3) it ensures that the folding deformation starts from the preset point, so that the final metal wrapping edge has a consistent height and uniform clamping force.

[0048] 4.2 The synergistic effect produced by the above parameter combination: The synergistic application of this set of parameters produces creative technical effects that far exceed the simple summation of individual parameters: This invention achieves "non-destructive large-angle plastic folding": With the combined effect of a 350 r / min rotation speed and a 0.45 mm / r feed rate, along with the guidance of a 105° main cutting edge tool and precise 0.05 mm starting point control, a 0.5 mm thick metal boss can undergo continuous, smooth plastic folding exceeding 90° (actually measured at 92°~95°) without cracking or breaking. This large-angle folding is a prerequisite for achieving complete mechanical encapsulation and locking, and is the core physical manifestation of this invention.

[0049] This results in a "continuous and uniform radial clamping force": this parameter combination ensures that the folding process is a uniform, controllable plastic deformation, rather than impact deformation. The folded metal wrapping edge retains precisely controlled residual stress due to its deformation history (determined by this specific set of parameters). This stress translates into a long-term, stable, and uniformly distributed radial clamping force on the non-metallic sealing ring step, which is crucial to preventing the sealing ring from "cold-flowing" or loosening during the high-frequency vibration and pressure cycles of the rocket engine.

[0050] Achieving highly reliable assembly with "zero process damage": a precise offset of 0.05mm avoids root cracks; optimized speed and feed rate prevent machining chatter; and the guiding effect of the 105° principal cutting edge angle reduces lateral forces. These three factors combine to ensure that the underlying non-metallic sealing ring is completely unaffected by shearing or crushing damage during the intense metal forming process, protecting the integrity of its sealing surface, thus achieving a perfect balance between metal forming and sealing protection.

[0051] Example 2 The present invention also provides a processing system for a composite sealing structure of a launch vehicle power valve. The processing system for the composite sealing structure of the launch vehicle power valve can be implemented by executing the process steps of the processing method for the composite sealing structure of the launch vehicle power valve. That is, those skilled in the art can understand the processing method for the composite sealing structure of the launch vehicle power valve as a preferred embodiment of the processing system for the composite sealing structure of the launch vehicle power valve.

[0052] The processing system for the composite sealing structure of a launch vehicle power valve according to the present invention includes: Module M1: Precision machining of valve disc metal substrate: A valve disc metal boss and an annular sealing groove are integrally machined on the end face of the valve disc metal substrate; wherein, the height and thickness of the valve disc metal boss are precisely machined to 0.5mm; Module M2: Precision machining and process verification of stepped non-metallic seals: Module M2.1: Machining annular non-metallic sealing rings by turning their end faces to ensure that the end face in contact with the bottom of the annular sealing groove has a flatness of ≤0.01mm and a surface roughness of Ra0.8; Module M2.2: The annular non-metallic sealing ring is machined to form a stepped structure, resulting in a stepped non-metallic seal; the design dimensions of the stepped non-metallic seal satisfy the following: its inner diameter is interference-fitted with the minor diameter of the annular sealing groove, and its outer diameter is clearance-fitted with the major diameter of the annular sealing groove. Module M2.3: After machining, use a special plug gauge to verify the process of the stepped non-metallic seal: insert the plug gauge into its inner hole and check whether its outer diameter after simulated expansion is accurately greater than the major diameter of the annular sealing groove by 0.01mm to 0.02mm. Module M3: Composite Assembly and Metal Encapsulation Forming Module M3.1: Press the stepped non-metallic seal into the annular sealing groove, ensuring that the height of the stepped non-metallic seal is lower than the opening of the annular sealing groove, with its stepped end face tightly against the side wall of the valve disc metal boss; during the pressing process, use a press and maintain the pressing state for 10 minutes. Module M3.2: The valve disc metal boss is rolled using a hobbing cutter. By controlling the machine tool spindle speed, hobbing feed speed and tool offset, the top of the valve disc metal boss undergoes plastic folding deformation inward, and the folding angle is greater than 90°, thereby forming a continuous metal flange that wraps around the upper part of the stepped non-metallic seal, ultimately forming a composite sealing structure.

[0053] The cutting head of the hobbing cutter structure is a circular hob with a tapered surface. The hob is mounted on a rotating shaft and rotates freely around the shaft, which is fixed to the tool holder.

[0054] The machine tool speed is 350 r / min, the hob feed rate is 0.45 mm / r, the hob main cutting edge angle is 105°, and the offset of the hob tip relative to the root of the valve disc metal boss is 0.01 mm to 0.1 mm.

[0055] The outer side of the valve disc metal substrate has a thin boss structure with a thickness of 0.25mm~0.9mm; the step width of the stepped non-metallic seal is 0.3mm~0.4mm greater than the height of the valve disc metal boss.

[0056] The interference fit between the inner ring of the stepped non-metallic seal and the inner ring of the annular sealing groove is 0.01mm~0.1mm; the stepped non-metallic seal and the outer ring of the annular sealing groove adopt a clearance fit, with a clearance of 0.01mm~0.05mm.

[0057] In the description of this application, it should be understood that the terms "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0058] Those skilled in the art will understand that, in addition to implementing the system, apparatus, and their modules provided by this invention in purely computer-readable program code, the same program can be implemented in the form of logic gates, switches, application-specific integrated circuits, programmable logic controllers, and embedded microcontrollers by logically programming the method steps. Therefore, the system, apparatus, and their modules provided by this invention can be considered a hardware component, and the modules included therein for implementing various programs can also be considered structures within the hardware component; alternatively, modules for implementing various functions can be considered both software programs implementing the method and structures within the hardware component.

[0059] Specific embodiments of the present invention have been described above. It should be understood that the present invention is not limited to the specific embodiments described above, and those skilled in the art can make various changes or modifications within the scope of the claims, which do not affect the essence of the present invention. Unless otherwise specified, the embodiments and features described in this application can be arbitrarily combined with each other.

Claims

1. A method for processing a composite sealing structure for a launch vehicle power valve, characterized in that, include: Step S1: Precision machining of valve disc metal substrate: A valve disc metal boss and an annular sealing groove are integrally machined on the end face of the valve disc metal substrate; wherein, the height and thickness of the valve disc metal boss are precisely machined to 0.5mm; Step S2: Precision machining and process verification of stepped non-metallic seals: Step S2.1: Machining the annular non-metallic sealing ring involves turning its end face to ensure that the end face in contact with the bottom of the annular sealing groove has a flatness of ≤0.01mm and a surface roughness of Ra0.

8. Step S2.2: The annular non-metallic sealing ring is machined to form a stepped structure, resulting in a stepped non-metallic seal; the design dimensions of the stepped non-metallic seal satisfy the following: its inner diameter is interference-fitted with the minor diameter of the annular sealing groove, and its outer diameter is clearance-fitted with the major diameter of the annular sealing groove. Step S2.3: After processing, use a special plug gauge to verify the process of the stepped non-metallic seal: insert the plug gauge into its inner hole and check whether its outer diameter after simulated expansion is accurately greater than the major diameter of the annular sealing groove by 0.01mm to 0.02mm. Step S3: Composite Assembly and Metal Encapsulation Forming: Step S3.1: Press the stepped non-metallic seal into the annular sealing groove, and make the height of the stepped non-metallic seal lower than the opening of the annular sealing groove, with its stepped end face tightly against the side wall of the valve disc metal boss; during the pressing process, use a press and maintain the pressing state for 10 minutes. Step S3.2: The valve disc metal boss is rolled using a hobbing cutter. By controlling the machine tool spindle speed, hobbing feed speed and tool offset, the top of the valve disc metal boss undergoes plastic folding deformation inward, and the folding angle is greater than 90°, thereby forming a continuous metal flange that wraps around the upper part of the stepped non-metallic seal, and finally forming a composite sealing structure.

2. The processing method of the composite sealing structure of the launch vehicle power valve according to claim 1, characterized in that, The cutting head of the hobbing cutter structure is a circular hob with a tapered surface. The hob is mounted on a rotating shaft and rotates freely around the shaft, which is fixed to the tool holder.

3. The processing method of the composite sealing structure of the launch vehicle power valve according to claim 2, characterized in that, The machine tool speed is 350 r / min, the hob feed rate is 0.45 mm / r, the hob main cutting edge angle is 105°, and the offset of the hob tip relative to the root of the valve disc metal boss is 0.01 mm to 0.1 mm.

4. The processing method of the composite sealing structure of the launch vehicle power valve according to claim 1, characterized in that, The outer side of the valve disc metal substrate has a thin boss structure with a thickness of 0.25mm~0.9mm; the step width of the stepped non-metallic seal is 0.3mm~0.4mm greater than the height of the valve disc metal boss.

5. The processing method of the composite sealing structure of the launch vehicle power valve according to claim 1, characterized in that, The interference fit between the inner ring of the stepped non-metallic seal and the inner ring of the annular sealing groove is 0.01mm~0.1mm; the stepped non-metallic seal and the outer ring of the annular sealing groove adopt a clearance fit, with a clearance of 0.01mm~0.05mm.

6. A machining system for a composite sealing structure of a launch vehicle power valve, characterized in that, include: Module M1: Precision machining of valve disc metal substrate: A valve disc metal boss and an annular sealing groove are integrally machined on the end face of the valve disc metal substrate; wherein, the height and thickness of the valve disc metal boss are precisely machined to 0.5mm; Module M2: Precision machining and process verification of stepped non-metallic seals: Module M2.1: Machining annular non-metallic sealing rings by turning their end faces to ensure that the end face in contact with the bottom of the annular sealing groove has a flatness of ≤0.01mm and a surface roughness of Ra0.8; Module M2.2: The annular non-metallic sealing ring is machined to form a stepped structure, resulting in a stepped non-metallic seal; the design dimensions of the stepped non-metallic seal satisfy the following: its inner diameter is interference-fitted with the minor diameter of the annular sealing groove, and its outer diameter is clearance-fitted with the major diameter of the annular sealing groove. Module M2.3: After machining, use a special plug gauge to verify the process of the stepped non-metallic seal: insert the plug gauge into its inner hole and check whether its outer diameter after simulated expansion is accurately greater than the major diameter of the annular sealing groove by 0.01mm to 0.02mm. Module M3: Composite Assembly and Metal Encapsulation Forming Module M3.1: Press the stepped non-metallic seal into the annular sealing groove, ensuring that the height of the stepped non-metallic seal is lower than the opening of the annular sealing groove, with its stepped end face tightly against the side wall of the valve disc metal boss; during the pressing process, use a press and maintain the pressing state for 10 minutes. Module M3.2: The valve disc metal boss is rolled using a hobbing cutter. By controlling the machine tool spindle speed, hobbing feed speed and tool offset, the top of the valve disc metal boss undergoes plastic folding deformation inward, and the folding angle is greater than 90°, thereby forming a continuous metal flange that wraps around the upper part of the stepped non-metallic seal, ultimately forming a composite sealing structure.

7. The machining system for the composite sealing structure of the launch vehicle power valve according to claim 6, characterized in that, The cutting head of the hobbing cutter structure is a circular hob with a tapered surface. The hob is mounted on a rotating shaft and rotates freely around the shaft, which is fixed to the tool holder.

8. The machining system for the composite sealing structure of the launch vehicle power valve according to claim 7, characterized in that, The machine tool speed is 350 r / min, the hob feed rate is 0.45 mm / r, the hob main cutting edge angle is 105°, and the offset of the hob tip relative to the root of the valve disc metal boss is 0.01 mm to 0.1 mm.

9. The machining system for the composite sealing structure of the launch vehicle power valve according to claim 6, characterized in that, The outer side of the valve disc metal substrate has a thin boss structure with a thickness of 0.25mm~0.9mm; the step width of the stepped non-metallic seal is 0.3mm~0.4mm greater than the height of the valve disc metal boss.

10. The machining system for the composite sealing structure of the launch vehicle power valve according to claim 6, characterized in that, The interference fit between the inner ring of the stepped non-metallic seal and the inner ring of the annular sealing groove is 0.01mm~0.1mm; the stepped non-metallic seal and the outer ring of the annular sealing groove adopt a clearance fit, with a clearance of 0.01mm~0.05mm.

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