A new manufacturing method for thin-walled alloy parts of diesel engines

Abstract

The application relates to a novel manufacturing method for a thin-wall alloy part of a diesel engine, which comprises the following steps: S1: forming a casting blank; and S2: mechanical processing manufacturing. The application optimizes pouring process parameters, strictly controls operation points in a pouring process, and sets a water cooling device at corresponding positions of a casting mold according to simulated simulation prediction of defect results and positions with high defect risks of a casting, so that the generation of shrinkage cavity and shrinkage porosity defects of the casting is reduced, and problems such as leakage and substandard performance caused by defects at key positions of the casting are avoided. Meanwhile, in the mechanical processing of the part, residual stress distribution is simulated through three-dimensional simulation, a processing process scheme and a pressing device are adjusted, a stress removal scheme is optimized, processing parameters are optimized, and stress deformation is reduced. The application is simple to operate, can be widely applied to stress processing of thin-wall high-precision alloy parts, and improves processing precision.

Description

Technical Field

[0001] This application relates to the field of thin-walled alloy parts manufacturing technology, and in particular to a novel manufacturing method for thin-walled alloy parts for diesel engines. Background Technology

[0002] A key military component serves as the carrier of the free-end transmission system of a diesel engine, transmitting power to the engine's cooling and lubrication systems, fuel supply system, and accessory systems. The parameters of this component have the most direct impact on the diesel engine's performance. Simultaneously, this component provides interfaces for the installation of external accessories such as thermostats, generators, air conditioning compressors, and fan drives. This part is a complex thin-walled aluminum alloy casting. Due to its special structure and high precision requirements, it is prone to shrinkage cavities, porosity, and hot cracking defects during the casting process. Deformation is also highly likely during machining, resulting in a yield rate of less than 10%. For example, the main problems with the low-pressure casting process for complex thin-walled box-shaped metal molds include the easy formation of shrinkage cavities and porosity defects in thick, hot joints; and the inconsistency in solidification shrinkage due to the casting structure, which easily leads to hot cracking at joints during the solidification stage. Furthermore, due to the complex, thin-walled, porous, and non-closed structural characteristics of the part, deformation is easily caused during machining due to clamping and processing forces, leading to dimensional and behavioral tolerance deformation.

[0003] With the development of computer simulation technology, numerical simulation of the casting process has become an important means of optimizing processes and predicting defects. Current casting process simulations mostly focus on the analysis of single processes (such as solidification or filling processes), lacking systematic simulation and closed-loop optimization of the entire process, including filling, solidification, and heat treatment. This results in insufficient process optimization and the continued existence of defects and risks such as cold shuts, incomplete filling, gas entrapment, shrinkage cavities, hot cracks, deformation, and residual stress, making it difficult to meet the high-quality production requirements of complex castings.

[0004] Therefore, there is an urgent need for a processing method that can cover the entire casting process and achieve collaborative control of multiple defects in order to improve casting quality, effectively eliminate stress, and reduce manufacturing costs. Summary of the Invention

[0005] The technical problem to be solved by this application is the stress deformation caused by processing during the entire manufacturing cycle of key components of diesel engines.

[0006] To address the aforementioned technical problems, this application provides a novel manufacturing method for thin-walled alloy parts for diesel engines, comprising the following steps:

[0007] S1: Casting blank forming:

[0008] a. Casting process simulation optimization: 1) Initial solidification analysis and preliminary determination of the pouring scheme; 2) Simulation of the filling process and optimization of the pouring system; 3) Simulation of the solidification process and optimization of the feeding system; 4) Simulation of the heat treatment process and optimization of the post-treatment process; 5) Process review and final process output;

[0009] b. Metal molten metal is smelted using rotary jet degassing refining technology;

[0010] c. Based on the final process optimized by simulation, carry out the casting operation, and identify high-risk areas of casting defects based on the results of the filling / solidification simulation;

[0011] d. Add water cooling devices to the high-risk areas of the casting mold to solidify the casting;

[0012] e. After the casting is poured, artificial aging and heat treatment are carried out, using the T6 process for long-term aging to reduce stress; then vibration aging is carried out, in which the casting is clamped on a vibration platform and the resonance frequency is detected using a special instrument. Mechanical resonance is used to eliminate and homogenize the residual stress inside the workpiece; finally, natural aging is carried out, in which the casting is placed in the open air for 3-6 months, relying on temperature difference and gravity to relax the internal residual stress and release the stress.

[0013] S2: Mechanical processing and manufacturing:

[0014] a. Clamping castings;

[0015] b. Cutting process.

[0016] S2: Mechanical processing and manufacturing:

[0017] a. Clamping castings;

[0018] b. Cutting process.

[0019] According to an embodiment of this application, step S1, the initial solidification analysis and preliminary determination of the casting scheme, includes the following specific steps:

[0020] (1) The first-round single solidification process simulation of the target casting was carried out. The solidification process of the casting was numerically calculated using casting simulation software to identify the location and size of hot spots in the casting.

[0021] (2) Based on the distribution of hot spots, the type of gating system, the gating location and the direction of shrinkage compensation are initially determined to form a preliminary gating scheme.

[0022] According to an embodiment of this application, step S1, the simulation of the filling process and the optimization of the gating system, further includes the following specific steps:

[0023] (1) Optimization analysis of filling temperature: Set different pouring temperatures and mold preheating temperatures to simulate the temperature field changes during the filling process of molten metal, analyze the fluidity of molten metal during the filling process, and identify the locations where cold shuts and incomplete pouring defects may occur;

[0024] (2) Optimization analysis of filling rate: By adjusting the parameters such as the cross-sectional area of ​​the gating gate and the pouring pressure of the gating system, the flow state of the molten metal is simulated, the flow field distribution during the filling process is analyzed, and the locations where air entrapment and slag formation defects may occur are identified.

[0025] (3) Optimization of the gating system: Based on the results of the filling simulation, optimize the structure and size of the gate, runner and ingate, optimize the filling temperature parameters, ensure the smooth filling of the molten metal and reduce the risk of defects in the filling process.

[0026] According to an embodiment of this application, step S1, the solidification process simulation and feeding system optimization step includes the following specific steps:

[0027] (1) Conduct shrinkage cavity and porosity simulation analysis to predict the location and size of shrinkage cavity and porosity defects in castings;

[0028] (2) Conduct hot cracking simulation analysis to assess the locations where hot cracks are likely to occur in the casting during solidification;

[0029] (3) Conduct gas retention simulation analysis to identify the locations in castings that are prone to porosity defects;

[0030] (4) Based on the above simulation results, the feeding system design is optimized through multiple rounds of iteration, the position, size and shape of the riser are adjusted, the arrangement of the chills is optimized, and the sequential solidification control of the casting is realized to eliminate or reduce the risk of shrinkage cavities, hot cracks and gas retention defects.

[0031] According to an embodiment of this application, step S1, the heat treatment process simulation and post-treatment process optimization step includes the following specific steps:

[0032] (1) Conduct deformation and shrinkage simulation analysis to predict the deformation trend and shrinkage of castings during heat treatment;

[0033] (2) Conduct residual stress simulation analysis to evaluate the residual stress distribution of the casting after heat treatment;

[0034] (3) Based on the deformation simulation results, reverse deformation design is carried out, and the deformation compensation amount is preset in advance in the mold design to offset the deformation during the heat treatment process;

[0035] (4) Based on the residual stress simulation results, optimize the shot peening process parameters, introduce compressive stress on the surface of the casting through shot peening, regulate the residual stress distribution of the casting, and improve the fatigue performance and dimensional stability of the casting.

[0036] According to the embodiments of this application, the final process includes pouring temperature, pouring rate, gating system parameters, feeding system parameters, heat treatment process parameters, and post-treatment process parameters, which serve as the basis for casting production.

[0037] According to an embodiment of this application, in step S1, during the molten metal smelting process, the rotary jet degassing is set to 0.3 MPa of Ar gas, 500-600 r / min rotation speed, 20-30 min time, hydrogen content ≤0.15 mL / 100 g Al, and temperature 720-730 °C.

[0038] According to an embodiment of this application, in step S1, the pouring temperature of the pouring operation is 690-710℃, the pouring time is ≤30s, and the water cooling device is: local water cooling of the mold, T mold = 250-300℃.

[0039] According to an embodiment of this application, during the machining process in step S2, the clamping torque is ≤5Nm and the hole position accuracy is ≤0.02mm.

[0040] According to the embodiments of this application, the clamping of the casting in step S2 specifically includes the following steps: 1) clamping with an adaptive fixture; 2) activating the synchronous equal torque pneumatic clamping function; 3) completing rapid positioning and confirming that the clamping is secure.

[0041] According to the embodiments of this application, the cutting process in step S2 specifically includes the following steps: 1) Installing special tools; 2) Setting the processing equipment according to the parameters of high speed, small depth of cut, and fast feed; 3) Carrying out cutting process: the processing flow is roughing, semi-finishing, finishing, vibration aging, and secondary finishing.

[0042] According to an embodiment of this application, the machining parameters of the machining tool are: rotational speed ≥ 6500 r / min, depth of cut ≤ 0.2 mm, and feed rate ≥ 1000 mm / min.

[0043] According to the embodiments of this application, in the roughing process, most of the excess material is removed, leaving a 2-3 mm allowance; in the semi-finishing process, a 0.5-1 mm allowance is left; the vibration aging is 30 min; in the finishing process, a 0.1-0.2 mm allowance is left; and in the secondary finishing process, a 0.05-0.1 mm allowance is left.

[0044] According to the embodiments of this application, the cutting process also includes special side processing, which includes the following steps: 1) Before the pin hole processing, all sides are rough milled uniformly and completed in one go, leaving a machining allowance; 2) After the pin hole processing, all sides are finely processed with the pin hole as the reference for positioning.

[0045] Compared with the prior art, the technical solution of this application has the following beneficial effects:

[0046] This application not only considers the causes of stress throughout the entire manufacturing cycle, but also simplifies operation and improves machining accuracy: First, through multi-dimensional simulation analysis, the process plan and parameters are optimized to avoid defects at the source, which is the foundation for subsequent casting; the aluminum alloy molten metal melting adopts rotary jet degassing refining technology to improve the purity of the aluminum alloy molten metal and reduce the hydrogen content of the alloy molten metal; the pouring operation is based on the simulation results to accurately identify high-risk areas of casting defects and avoid inherent defects caused by cold shuts and uneven wall thickness; water cooling devices are added to the corresponding high-risk areas of the casting mold to control the local solidification rate and reduce the incidence of shrinkage cavities and porosity defects in the casting; stress is released step by step through multi-processing and vibration aging, and secondary finishing ensures the final accuracy; customized adaptive fixtures improve clamping efficiency and eliminate the manual alignment process; by dividing general cutting requirements and special side machining, machining deformation caused by tool cutting force, resonance, and high temperature is reduced to meet machining accuracy requirements. Attached Figure Description

[0047] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings of the embodiments will be briefly described below. Obviously, the drawings described below only relate to some embodiments of this application, and are not intended to limit this application.

[0048] Figure 1 This is a schematic diagram illustrating the simulation and optimization process of casting process during the forming of a casting blank, as exemplified by the present invention.

[0049] Figure 2 This is a flowchart illustrating the steps of a novel manufacturing method for thin-walled alloy parts for diesel engines, as exemplified by the present invention. Detailed Implementation

[0050] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this application. Based on the described embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0051] Unless otherwise defined, the technical or scientific terms used herein shall have the ordinary meaning as understood by one of ordinary skill in the art to which this application pertains. The terms “first,” “second,” and similar terms used in the specification and claims of this patent application do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Similarly, the terms “an” or “a,” and similar terms, do not indicate a limitation of quantity, but rather indicate the presence of at least one.

[0052] like Figure 1 , Figure 2 As shown, this application exemplifies a novel manufacturing method for thin-walled alloy parts for diesel engines, comprising the following steps: S1: casting blank forming; S2: machining manufacturing. This application utilizes three-dimensional simulation technology to analyze and calculate the residual stress distribution during machining, and conducts experimental research and verification on influencing factors such as structure, shape, wall thickness, residual stress of the parts, and the selection of positioning and clamping methods and pressure points during machining of medium-to-large-sized thin-walled complex irregular parts. This results in the formation of stress deformation control technology, achieving dimensional stability. Furthermore, this application conducts extensive experimental verification of tool parameters using customized special-purpose tools, combines three-dimensional simulation technology research and analysis of the machining process with numerous research and development trials of multiple schemes, designs dedicated and efficient tooling, and forms an optimal comprehensive control technology scheme for dimensional and shape positional accuracy. This achieves high-precision machining and control of key dimensions, meeting the overall development requirements.

[0053] In this embodiment, S1: Casting blank forming:

[0054] a. Optimization of casting process simulation: 1) Initial solidification analysis and preliminary determination of pouring scheme; 2) Simulation of filling process and optimization of pouring system; 3) Simulation of solidification process and optimization of feeding system; 4) Simulation of heat treatment process and optimization of post-treatment process; 5) Process review and final process output.

[0055] Specifically, such as Figure 1 As shown, the specific steps of the casting process simulation optimization method are as follows:

[0056] Step 1: Initial solidification analysis and preliminary determination of the casting scheme

[0057] The first round of single solidification process simulation was conducted on the target casting. Casting simulation software was used to numerically calculate the solidification process of the casting and identify the location and size of hot spots in the casting. Based on the distribution of hot spots, the type of gating system, the pouring location, and the feeding direction were preliminarily determined, forming a preliminary pouring scheme.

[0058] Step 2: Simulation of the filling process and optimization of the gating system

[0059] 1. Optimization analysis of filling temperature: Set different pouring temperatures and mold preheating temperatures to simulate the temperature field changes during the filling process of molten metal, analyze the fluidity of molten metal during the filling process, and identify the locations where cold shuts and incomplete filling defects may occur;

[0060] 2. Filling rate optimization analysis: By adjusting parameters such as the gate cross-sectional area and pouring pressure of the gating system, the flow state of molten metal is simulated, the flow field distribution during the filling process is analyzed, and the locations where air entrapment and slag formation defects may occur are identified.

[0061] 3. Optimization of the gating system: Based on the results of the filling simulation, the structure and size of the gate, runner and ingate are optimized, and the filling temperature parameters are optimized to ensure that the molten metal fills the mold smoothly and reduce the risk of defects in the filling process.

[0062] Step 3: Solidification process simulation and feeding system optimization

[0063] 1. Conduct shrinkage cavity and porosity simulation analysis to predict the location and size of shrinkage cavity and porosity defects in castings;

[0064] 2. Conduct hot cracking simulation analysis to assess the locations where hot cracks are likely to occur in the casting during solidification;

[0065] 3. Conduct gas retention simulation analysis to identify locations in castings prone to porosity defects;

[0066] 4. Based on the above simulation results, the feeding system design is optimized through multiple rounds of iteration, the position, size and shape of the riser are adjusted, the arrangement of the chills is optimized, and the sequential solidification control of the casting is achieved, eliminating or reducing the risk of shrinkage cavities, hot cracks and gas retention defects.

[0067] Step 4: Simulation of heat treatment process and optimization of post-treatment process

[0068] 1. Conduct deformation and shrinkage simulation analysis to predict the deformation trend and shrinkage of castings during heat treatment;

[0069] 2. Conduct residual stress simulation analysis to evaluate the residual stress distribution of the casting after heat treatment;

[0070] 3. Based on the deformation simulation results, perform anti-deformation design and pre-set the deformation compensation amount in the mold design to offset the deformation during the heat treatment process;

[0071] 4. Based on the residual stress simulation results, optimize the shot peening process parameters (such as shot peening pressure, shot peening time, shot diameter, etc.), introduce compressive stress on the surface of the casting through shot peening, regulate the residual stress distribution of the casting, and improve the fatigue performance and dimensional stability of the casting.

[0072] Step 5: Process Review and Final Process Output

[0073] Technical personnel specializing in process engineering, simulation, and production conduct a comprehensive review of the optimized gating system, feeding system, and post-processing techniques to verify the matching, feasibility, and stability of the process parameters at each stage. Upon successful review, a final casting process plan is developed, including parameters for pouring temperature, pouring rate, gating system parameters, feeding system parameters, heat treatment parameters, and post-processing parameters, serving as the basis for casting production.

[0074] b. Rotary jet degassing refining technology is used for molten metal melting; this step addresses defects such as shrinkage cavities, porosity, and pinholes. During the molten aluminum alloy melting process, rotary jet degassing refining technology is used to improve the purity of the molten aluminum alloy, reduce the hydrogen content of the molten alloy, and solve the problem of pinhole defects in castings.

[0075] c. Based on the optimized casting parameters from the simulation process, carry out the casting operation, and accurately identify high-risk areas of casting defects using the filling / solidification simulation results as a benchmark;

[0076] d. A water-cooling device is added to the high-risk areas of the casting mold to facilitate casting solidification. In this step, the temperature and flow rate of the water-cooling device are adjusted as needed (aiming to reduce shrinkage cavities and porosity defects), ensuring that the casting has no critical defects after solidification.

[0077] Specifically, in step S1, during the molten metal smelting process, the rotary jet degassing is set to 0.3 MPa of Ar gas, 500-600 r / min rotation speed, 20-30 min time, hydrogen content ≤0.15 mL / 100 g Al, and temperature 720-730 ℃.

[0078] Specifically, in step S1, the pouring temperature is 690-710℃, the pouring time is ≤30s, and the water cooling device is: local water cooling of the mold, T mold = 250-300℃.

[0079] S2: Mechanical processing and manufacturing:

[0080] a. Clamping castings;

[0081] b. Cutting process.

[0082] Specifically, step S2, clamping the casting, includes the following steps: 1) clamping using an adaptive fixture; 2) activating the synchronous equal torque pneumatic clamping function; 3) completing rapid positioning and confirming secure clamping. This adaptive fixture is designed primarily for the machining processes of key support parts of various assembly structural components. It employs pneumatic control and features the typical characteristic of clamping multiple parts at once for simultaneous machining, effectively avoiding the accuracy loss caused by repeated disassembly and assembly. The workpiece support uses a rigid adjustable mechanism, which effectively ensures machining stability and eliminates cutting vibration, while also effectively controlling the deformation problems caused by traditional manual clamping of the workpiece.

[0083] Specifically, in step S2 of the machining process, the clamping torque is ≤5Nm and the hole position accuracy is ≤0.02mm.

[0084] Specifically, step S2 includes the following steps for cutting: 1) Installing a special tool; 2) Setting the machining equipment according to high speed, small depth of cut, and rapid feed parameters; 3) Carrying out cutting: the machining process consists of roughing, semi-finishing, finishing, vibration aging, and secondary finishing, releasing machining stress step by step, controlling the deformation of thin-walled parts, and ensuring final accuracy. The preferred machining parameters for the tool are: speed ≥ 6500 r / min, depth of cut ≤ 0.2 mm, and feed rate ≥ 1000 mm / min.

[0085] Specifically, in rough machining, most of the excess material is removed, leaving a 2-3mm allowance; in semi-finish machining, a 0.5-1mm allowance is left; vibration aging is performed for 30 minutes; in finish machining, a 0.1-0.2mm allowance is left; and in secondary finish machining, a 0.05-0.1mm allowance is left.

[0086] Specifically, the cutting process also includes specialized side machining, which includes the following steps: 1) Before machining the pin holes, all sides are rough milled uniformly in one go, leaving machining allowance; 2) After machining the pin holes, all sides are precision machined using the pin holes as the reference for positioning. This machining process uses the machined pin holes as the reference for positioning and precision machining of all sides to ensure the shape and position accuracy and consistency of each side.

[0087] Example 1: Manufacturing and processing of a certain part

[0088] Manufacturing of the parts: The key component is made of ZL111 steel with an average wall thickness of 5.5 mm and a minimum wall thickness of less than 3 mm, requiring extremely high casting precision. It contains crankshaft positioning holes, air compressor positioning holes, gear shaft mounting holes, water pump holes, power output holes, oil pump holes, and locating pin holes, etc. The center distance of each hole has a positional accuracy of 0.02 mm, requiring high dimensional and positional accuracy, with a dimensional accuracy grade of 7. The flatness of the crankcase mating surface is 0.06 mm, with a large machined surface and high precision requirements. The sides mainly include the oil radiator mating surface, oil pan mating surface, oil filter mating surface, 90° side surfaces, 45° inclined surfaces, and 10° inclined surfaces, etc., which are scattered, requiring high dimensional and geometric tolerance accuracy and high surface roughness.

[0089] For the above machining processes, 3D simulation technology was used to study and analyze the impact of the machining sequence of each process and the different machining allowances for each process on the deformation and dimensional stability of the parts. Through calculation and experimental research and analysis of multiple schemes, the optimal machining allowance was finally determined to ensure the smooth connection between each process.

[0090] By applying the natural aging method, the residual internal stress of the parts is removed from the blank. By applying scientific and reasonable planning and production scheduling, the parts casting is arranged in advance. After the casting is completed, rough machining is carried out. After the rough machining process is completed, the parts blanks are placed naturally in the outdoor area for 1 month. The natural aging method is used to remove some of the residual stress of the parts.

[0091] After the part begins machining, vibration aging is used to treat it after the rough machining process. This process utilizes the principle of vibration aging to quickly remove residual stress, providing favorable conditions for subsequent machining processes.

[0092] After the semi-finishing process, a secondary vibration aging treatment is performed on the parts. Through the principle of vibration aging, residual internal stress in the parts is relatively thoroughly removed. This provides favorable conditions for finishing and indirectly ensures the final dimensional and shape positional accuracy of the product.

[0093] By applying 3D simulation technology, we can quickly, effectively, and reasonably design specialized tooling fixtures, so that the parts are in a reasonable clamping and positioning state for machining, thus eliminating the deformation problem of the parts themselves during clamping.

[0094] Example 2: Technical solution for machining the perpendicularity of the crankshaft center hole before vibration to remove residual stress

[0095] After the rough milling of each surface is completed and before the aging process, in order to reserve deformation for stress release during aging, the ○C reference plane is reserved by 0.5, the overall flatness is guaranteed to be 0.06, Φ50+0.025 is pre-machined to Φ49, and the Φ7.8 hole is machined to the finished product (to avoid burrs, extrusion micro-transformation protrusions, etc. at the intersection after finishing with the Φ50 hole, which would affect the quality of the Φ50 hole).

[0096] After aging, the flatness of the ○C datum plane is 0.1 and 0.05 / 100, and the locating pin holes of Φ50+0.025 and Φ10+0.02+0.005 are machined in one process to ensure the coordinate dimensions of 340±0.03, 170±0.02, 169±0.02, and 158.397±0.03, the crankshaft hole position accuracy of 0.05mm, and the perpendicularity of the crankshaft hole to the ○C datum plane of 0.015.

[0097] Example 3: High-precision machining technology for mounting hole positioning

[0098] After the rough milling of each surface is completed and before the aging process, the water pump mounting plane is left with a margin of 0.5 and the parallelism with the ○C datum plane is ensured to be 0.08. The water pump mounting hole, oil pump mounting hole and oil pump mounting hole are pre-machined with a margin of 1 in the diameter direction.

[0099] Using the precision-machined datum surface as the positioning plane, the Φ10+0.02+0.005 positioning pin hole is used for positioning. Tooling fixtures are used to complete the precision machining of the horizontal installation plane to ensure the parallelism requirement of the ○C datum surface. The water pump mounting hole, oil pump mounting hole, and oil pump mounting hole are also precision-machined to ensure the positional accuracy between the three holes.

[0100] In summary, the technical solution of this application has the following beneficial effects:

[0101] This application not only considers the causes of stress throughout the entire manufacturing cycle, but also simplifies operation and improves machining accuracy: First, through multi-dimensional simulation analysis, the process plan and parameters are optimized to avoid defects at the source, which is the foundation for subsequent casting; the aluminum alloy molten metal melting adopts rotary jet degassing refining technology to improve the purity of the aluminum alloy molten metal and reduce the hydrogen content of the alloy molten metal; the pouring operation is based on the simulation results to accurately identify high-risk areas of casting defects and avoid inherent defects caused by cold shuts and uneven wall thickness; water cooling devices are added to the corresponding high-risk areas of the casting mold to control the local solidification rate and reduce the incidence of shrinkage cavities and porosity defects in the casting; stress is released step by step through multi-processing and vibration aging, and secondary finishing ensures the final accuracy; customized adaptive fixtures improve clamping efficiency and eliminate the manual alignment process; by dividing general cutting requirements and special side machining, machining deformation caused by tool cutting force, resonance, and high temperature is reduced to meet machining accuracy requirements.

[0102] The above are merely exemplary embodiments of this application and are not intended to limit the scope of protection of this application, which is determined by the appended claims.

Claims

1. A novel manufacturing method for thin-walled alloy parts for diesel engines, characterized in that, Includes the following steps: S1: Casting blank forming: a. Casting process simulation optimization: 1) Initial solidification analysis and preliminary determination of the pouring scheme; 2) Simulation of the filling process and optimization of the pouring system; 3) Simulation of the solidification process and optimization of the feeding system; 4) Simulation of the heat treatment process and optimization of the post-treatment process; 5) Process review and final process output; b. Metal molten metal is smelted using rotary jet degassing refining technology; c. Based on the final process optimized by simulation, carry out the casting operation, and accurately identify high-risk areas of casting defects using the filling / solidification simulation results as a benchmark; d. Add water cooling devices to the high-risk areas of the casting mold to solidify the casting; e. After the casting is poured, artificial aging and heat treatment are carried out, using the T6 process for long-term aging to reduce stress; Next, vibration aging is performed. The casting is clamped onto a vibration platform, and the resonance frequency is detected using a special instrument. Mechanical resonance is used to eliminate and homogenize the residual stress inside the workpiece. Finally, natural aging is performed. The casting is placed outdoors for 3-6 months, and the internal residual stress is relaxed and released by temperature difference and gravity. S2: Mechanical processing and manufacturing: a. Clamping castings; b. Cutting process.

2. A novel manufacturing method for thin-walled alloy parts for diesel engines according to claim 1, characterized in that, In step S1, the initial solidification analysis and preliminary determination of the casting scheme include the following specific steps: (1) The first-round single solidification process simulation of the target casting was carried out. The solidification process of the casting was numerically calculated using casting simulation software to identify the location and size of hot spots in the casting. (2) Based on the distribution of hot spots, the type of gating system, the gating location and the direction of shrinkage compensation are initially determined to form a preliminary gating scheme.

3. A novel manufacturing method for thin-walled alloy parts for diesel engines according to claim 1, characterized in that, In step S1, the simulation of the filling process and the optimization of the casting system further include the following specific steps: (1) Optimization analysis of filling temperature: Set different pouring temperatures and mold preheating temperatures to simulate the temperature field changes during the filling process of molten metal, analyze the fluidity of molten metal during the filling process, and identify the locations where cold shuts and incomplete pouring defects may occur; (2) Optimization analysis of filling rate: By adjusting the parameters such as the cross-sectional area of ​​the gating gate and the pouring pressure of the gating system, the flow state of the molten metal is simulated, the flow field distribution during the filling process is analyzed, and the locations where air entrapment and slag formation defects may occur are identified. (3) Optimization of the gating system: Based on the results of the filling simulation, optimize the structure and size of the gate, runner and ingate, optimize the filling temperature parameters, ensure the smooth filling of the molten metal and reduce the risk of defects in the filling process.

4. A novel manufacturing method for thin-walled alloy parts for diesel engines according to claim 1, characterized in that, In step S1, the solidification process simulation and feeding system optimization steps include the following specific steps: (1) Conduct shrinkage cavity and porosity simulation analysis to predict the location and size of shrinkage cavity and porosity defects in castings; (2) Conduct hot cracking simulation analysis to assess the locations where hot cracks are likely to occur in the casting during solidification; (3) Conduct gas retention simulation analysis to identify the locations in castings that are prone to porosity defects; (4) Based on the above simulation results, the feeding system design is optimized through multiple rounds of iteration, the position, size and shape of the riser are adjusted, the arrangement of the chills is optimized, and the sequential solidification control of the casting is realized to eliminate or reduce the risk of shrinkage cavities, hot cracks and gas retention defects.

5. A novel manufacturing method for thin-walled alloy parts for diesel engines according to claim 1, characterized in that, In step S1, the heat treatment process simulation and post-treatment process optimization step includes the following specific steps: (1) Conduct deformation and shrinkage simulation analysis to predict the deformation trend and shrinkage of castings during heat treatment; (2) Conduct residual stress simulation analysis to evaluate the residual stress distribution of the casting after heat treatment; (3) Based on the deformation simulation results, reverse deformation design is carried out, and the deformation compensation amount is preset in advance in the mold design to offset the deformation during the heat treatment process; (4) Based on the residual stress simulation results, optimize the shot peening process parameters, introduce compressive stress on the surface of the casting through shot peening, regulate the residual stress distribution of the casting, and improve the fatigue performance and dimensional stability of the casting.

6. A novel manufacturing method for thin-walled alloy parts for diesel engines according to claim 1, characterized in that, The final process includes pouring temperature, pouring rate, gating system parameters, feeding system parameters, heat treatment process parameters, and post-treatment process parameters, which serve as the basis for casting production.

7. A novel manufacturing method for thin-walled alloy parts for diesel engines according to claim 1, characterized in that, During the machining process in step S2, the clamping torque is ≤5Nm and the hole position accuracy is ≤0.02mm.

8. A novel manufacturing method for thin-walled alloy parts for diesel engines according to claim 1, characterized in that, The specific steps for clamping the casting in step S2 include: 1) using an adaptive clamp; 2) activating the synchronous equal torque pneumatic clamping function; 3) completing rapid positioning and confirming that the clamping is secure.

9. A novel manufacturing method for thin-walled alloy parts for diesel engines according to claim 1, characterized in that, The cutting process in step S2 specifically includes the following steps: 1) Install special cutting tools; 2) Set the machining equipment according to the parameters of high speed, small depth of cut and fast feed; 3) Carry out cutting: the machining process is roughing, semi-finishing, finishing, vibration aging and secondary finishing.

10. A novel manufacturing method for thin-walled alloy parts for diesel engines according to claim 9, characterized in that, In the roughing process, most of the excess material is removed, leaving a 2-3mm allowance; in the semi-finishing process, a 0.5-1mm allowance is left; the vibration aging is performed for 30 minutes; in the finishing process, a 0.1-0.2mm allowance is left; in the secondary finishing process, a 0.05-0.1mm allowance is left; the cutting process also includes special side processing, which includes the following steps: 1) Before the pin hole processing, all sides are rough milled uniformly in one go, leaving a machining allowance; 2) After the pin hole processing, all sides are finished using the pin hole as a reference for positioning.

Images