Intelligent quenching control system for hollow substrate of automobile camshaft

Abstract

The present invention discloses an intelligent quenching control system for a hollow substrate of an automobile camshaft, which relates to the field of quenching control and solves the problem that the quenching process of the hollow substrate of the automobile camshaft corresponding to the original workpiece cannot be optimized and controlled according to the strain situation when the hollow substrate of the automobile camshaft is processed. The intelligent quenching control system comprises a material analysis module, a heat treatment processing module, a quenching analysis module, a strain judgment module and a quenching optimization module. The material analysis module is used to set a heat treatment processing flow for the original workpiece corresponding to the hollow substrate of the automobile camshaft, and the heat treatment processing module is used to process the original workpiece; the quenching analysis module is used to analyze the total strain generated by the original workpiece in the quenching sub-flow; the strain judgment module is used to judge the total strain generated by the original workpiece in the quenching sub-flow; and the quenching optimization module is used to optimize the quenching sub-flow. The present invention realizes optimized control of the quenching process of the original workpiece corresponding to the hollow substrate of the automobile camshaft.

Description

Technical Field

[0001] The invention belongs to the technical field of quenching control, in particular to an intelligent quenching control system for a hollow substrate of an automobile camshaft. Background Art

[0002] The hollow base of the automotive camshaft is a core component of the piston engine, used to control the opening and closing of the valves, ensuring sufficient air intake and exhaust in the cylinder, and directly affecting the engine's power performance and operating characteristics. It has the advantage of being light in weight. However, due to its light weight, in order to ensure that the hardness of the hollow base of the automotive camshaft meets the standard, it is necessary to ensure that the quenching process of the original workpiece is complete.

[0003] However, when quenching the hollow substrate of an automotive camshaft, if there is a need to optimize the quenching process, the traditional method can only make gradual adjustments through enumeration, without analyzing the strain of the original workpiece during quenching and making optimized control, resulting in a large waste of human resources.

[0004] To this end, the present invention proposes an intelligent quenching control system for a hollow substrate of an automobile camshaft. Summary of the Invention

[0005] The purpose of the present invention is to propose an intelligent quenching control system for a hollow substrate of an automobile camshaft, so as to solve the problems raised in the above background technology.

[0006] In order to achieve the above object, the present invention adopts the following technical solutions:

[0007] An intelligent quenching control system for a hollow automotive camshaft substrate includes a data acquisition module, a material analysis module, a heat treatment module, a quenching analysis module, a strain determination module, and a quenching optimization module. The data acquisition module is used to collect the material type and expected processing dimensions of the original workpiece corresponding to the hollow automotive camshaft substrate and send them to the material analysis module. The material analysis module is used to set an initial heat treatment process flow for the original workpiece corresponding to the hollow automotive camshaft substrate and send the set heat treatment process flow of the original workpiece to the heat treatment module.

[0008] The heat treatment processing module is used to process the original workpiece according to the heat treatment processing flow, obtain a temperature field model of the original workpiece, and send it to the quenching analysis module; the quenching analysis module is used to analyze the total strain generated by the original workpiece in the quenching sub-process in combination with the temperature field model, and obtain the total thermal strain and total phase change strain of the original workpiece at all times in the quenching sub-process and send them to the strain judgment module;

[0009] The strain judgment module is used to judge the total strain generated by the original workpiece in the quenching sub-process, and send the phase change adjustment signal, thermal strain adjustment signal and corresponding time number generated by the judgment to the quenching optimization module; the quenching optimization module is used to optimize the quenching sub-process.

[0010] Further, the expected processing dimensions include the outer diameter of the hollow base, the inner diameter of the hollow base, and the length of the hollow base;

[0011] Workpiece material types include low alloy steel, ductile iron, and powder metallurgy steel.

[0012] Furthermore, the working process of the material analysis module is as follows:

[0013] Obtain the workpiece material type and expected processing dimensions of the original workpiece corresponding to the hollow substrate of the automobile camshaft, and obtain the outer diameter, inner diameter, and length of the hollow substrate;

[0014] The internal aspect ratio is obtained by dividing the length of the hollow substrate by the internal diameter of the hollow substrate; the external aspect ratio is obtained by dividing the length of the hollow substrate by the external diameter of the hollow substrate; and the aspect ratio difference is obtained by subtracting the internal aspect ratio from the external aspect ratio;

[0015] Identify multiple historical heat treatment processes of the same workpiece material type according to the workpiece material type of the hollow substrate of the automobile camshaft corresponding to the original workpiece, and obtain the historical substrate outer diameter, historical substrate inner diameter, and historical substrate length of the hollow substrate of the automobile camshaft by identifying the corresponding historical heat treatment processes;

[0016] Similarly, calculate the historical aspect ratio difference of the hollow substrate of the automobile camshaft corresponding to the historical heat treatment process;

[0017] The matrix length similarity value is obtained by taking the absolute value of the difference between the hollow matrix length and the historical matrix length and dividing it by the hollow matrix length; the matrix aspect ratio similarity value is obtained by taking the absolute value of the difference between the aspect ratio difference and the historical aspect ratio difference and dividing it by the aspect ratio difference;

[0018] The matrix aspect ratio similarity value and the matrix length similarity value are multiplied by the corresponding proportional coefficients in sequence and then added together to obtain the corresponding processing similarity;

[0019] If any processing similarity is greater than or equal to the processing similarity threshold, the heat treatment process is sorted in descending order of processing similarity, and the historical heat treatment process at the top is selected as the corresponding heat treatment process;

[0020] If all processing similarities are less than the processing similarity threshold, the design plan of the heat treatment process is executed.

[0021] Furthermore, the heat treatment process specifically includes: a first heating sub-process, a first holding sub-process, a quenching sub-process, a second heating sub-process, a second holding sub-process and an annealing sub-process, and each sub-process includes the expected processing time and expected processing temperature of the sub-process.

[0022] Furthermore, the processing process of the heat treatment processing module is as follows:

[0023] Obtaining the heat treatment process flow of the original workpiece, obtaining a first heating sub-process, a first holding sub-process, a quenching sub-process, a second heating sub-process, a second holding sub-process, and an annealing sub-process; the heat treatment processing module sequentially executes the above sub-processes and performs analysis when executing the quenching sub-process;

[0024] The heat conduction control equation and boundary conditions of the original workpiece are obtained through analysis. The boundary conditions include inner surface boundary conditions and outer surface boundary conditions.

[0025] The temperature field model of the original workpiece is obtained by integrating the inner surface boundary conditions, outer surface boundary conditions and heat conduction control equations; wherein, the temperature field model is used to describe the real-time temperature value of the original workpiece at any spatial point at any time in the quenching sub-process.

[0026] Furthermore, the analysis process of the quenching sub-process is specifically as follows:

[0027] Pour quenching liquid onto the surface of the original workpiece and measure the real-time temperature value of any spatial point of the original workpiece;

[0028] Construct the real-time temperature field of the original workpiece in the quenching sub-process, regard the original workpiece as a cylindrical object, establish a cylindrical coordinate system corresponding to the original workpiece, and record any spatial point on the original workpiece as P (r, θ, z);

[0029] Where r is the mirror distance, which refers to the distance from the projection point of the spatial point on the reference plane to the origin, and its value is greater than zero; θ is the azimuth, which refers to the angle between the projection point and the X-axis, and its value is between 0 and 2π; z is the vertical height, which refers to the coordinate value along the z-axis;

[0030] The heat conduction control equation of the original workpiece is constructed by the heat conduction law. The heat conduction control equation is as follows:

[0031] Wherein, ρ is the material density of the original workpiece corresponding to the workpiece material type, c is the material specific heat capacity of the original workpiece corresponding to the workpiece material type; SWD is the real-time temperature value of the spatial point above the original workpiece, and SJ is the number at different times; Indicates the rate at which the workpiece's heat conduction controls the temperature change over time; RD is the thermal conductivity of the original workpiece corresponding to the workpiece material type;

[0032] is the radial heat conduction term; is the axial heat conduction term;

[0033] The expression on the left represents the thermal energy accumulation rate of the original workpiece per unit time; the expression on the right represents the net heat inflow rate caused by heat conduction to the original workpiece;

[0034] The boundary conditions of the original workpiece are constructed based on the outer diameter and the inner diameter of the hollow substrate. The boundary conditions are as follows:

[0035] External surface boundary conditions: ; In the formula, the value of r is the outer diameter of the hollow substrate divided by two; CR is the heat transfer coefficient, and WDh is the real-time ambient temperature;

[0036] The left-hand term represents the rate at which internal heat is transferred to the outer surface, and the sign indicates that the direction of heat transfer is opposite to the distribution direction of the temperature gradient; the right-hand term represents the rate at which the quenching liquid removes heat from the outer surface;

[0037] Internal surface boundary conditions: ; In the formula, the value of r is the hollow inner diameter divided by two, and CRn is the internal heat transfer coefficient.

[0038] Furthermore, the analysis process of the quenching analysis module is as follows:

[0039] Obtain the temperature field model of the original workpiece, and then obtain the real-time temperature value SWD of the original workpiece at any spatial point at any time in the quenching sub-process;

[0040] Compare the real-time temperature values ​​of the original workpiece at all spatial points in the quenching sub-process with the transformation temperature value ZWD of martensite;

[0041] If the real-time temperature values ​​of all spatial points are greater than the transformation temperature value of martensite, no operation is performed; if the real-time temperature value of any spatial point is less than or equal to the transformation temperature value of martensite, it is determined that the martensite transformation process has started, and the martensite transformation success rate ZHL of the original workpiece at any time during the quenching process is calculated by the formula. The specific formula is as follows:

[0042] ; In the formula, e is the natural constant and β is the material constant;

[0043] The number of conversions of spatial points whose real-time temperature value is less than or equal to the conversion temperature value is counted, and the conversion rate of the spatial point at the corresponding moment is obtained by dividing the number of conversions by the total number of spatial points.

[0044] Furthermore, the analysis process of the quenching analysis module also includes:

[0045] When the spatial point conversion rate is less than the conversion rate threshold, no operation is performed;

[0046] When the spatial point conversion rate is greater than or equal to the conversion rate threshold, the calculation of the martensite conversion success rate is stopped, and the calculated martensite conversion success rates are summarized with the time as the number;

[0047] The total phase transformation strain of the original workpiece at the corresponding moment is obtained by multiplying the martensite transformation success rate by the spatial point transformation rate by the transformation volume expansion coefficient at the same moment;

[0048] The thermal expansion strain of any spatial point at all times is calculated by the formula. The formula for thermal expansion strain is as follows:

[0049] Thermal expansion strain = thermal expansion coefficient × (real-time temperature value - ambient temperature value);

[0050] The total thermal strain of the original workpiece at the corresponding moment is obtained by adding up the thermal expansion strains of all spatial points.

[0051] Furthermore, the judgment process of the strain judgment module is as follows:

[0052] Obtain the total thermal strain and total phase transformation strain of the original workpiece at all times in the quenching sub-process;

[0053] The total phase change strain of the original workpiece is compared with the phase change strain threshold. If the total phase change strain is greater than or equal to the phase change strain threshold, a phase change adjustment signal at the corresponding moment is generated; if the total phase change strain is less than the phase change strain threshold, the process proceeds to the next step.

[0054] The total thermal strain of the original workpiece is compared with the thermal strain threshold. If the total thermal strain at any moment is greater than or equal to the thermal strain threshold, the real-time temperature values ​​of all spatial points at the corresponding moment are identified. The real-time temperature values ​​of all spatial points at the corresponding moment are added and averaged to obtain the average temperature value at the corresponding moment.

[0055] The variance of the real-time temperature values ​​corresponding to all spatial points is calculated based on the average temperature value and recorded as the variance temperature value;

[0056] The first comparison temperature value is obtained by subtracting the variance temperature value from the average temperature value, and the second comparison temperature value is obtained by adding the variance temperature value to the average temperature value; the temperature comparison interval at the corresponding moment is obtained with the first comparison temperature value as the left endpoint and the second comparison temperature value as the right endpoint;

[0057] If the real-time temperature value is outside the temperature comparison interval, the corresponding spatial point is regarded as an abnormal spatial point and a thermal strain adjustment signal is generated; if the real-time temperature value is within the temperature comparison interval, no operation is performed.

[0058] Furthermore, the optimization process of the quenching optimization module is as follows:

[0059] Obtaining a phase change adjustment signal, a thermal strain adjustment signal, and corresponding time numbers;

[0060] Replace the operations in the quenching sub-process based on the time number, specifically:

[0061] If the signal is for phase transformation adjustment, the martensite formation rate is smoothed by extending the air cooling method or injecting quenching liquid through a distributed nozzle;

[0062] If it is a thermal strain adjustment signal, the temperature difference between the inner and outer surfaces is reduced by reducing the injection amount of quenching liquid and blowing it into the corresponding inner cavity of the original workpiece.

[0063] In summary, due to the adoption of the above technical solution, the beneficial effects of the present invention are:

[0064] 1. The present invention first collects the material type and expected processing dimensions of the original workpiece corresponding to the hollow substrate of the automobile camshaft, and then uses the material analysis module to set a corresponding heat treatment processing flow for the original workpiece corresponding to the hollow substrate of the automobile camshaft. The present invention facilitates setting an adaptive heat treatment processing process for the original workpiece corresponding to the hollow substrate of the automobile camshaft;

[0065] 2. The heat treatment processing module in the present invention processes the original workpiece in combination with the heat treatment processing flow to obtain a temperature field model of the original workpiece, and then the quenching analysis module analyzes the total strain generated by the original workpiece in the quenching sub-process in combination with the temperature field model. The total thermal strain and total phase change strain of the original workpiece at all times in the quenching sub-process are analyzed and sent to the strain judgment module. The strain judgment module judges the total strain generated by the original workpiece in the quenching sub-process, and sends the generated phase change adjustment signal, thermal strain adjustment signal and corresponding moment number to the quenching optimization module. Finally, the quenching sub-process is optimized by the quenching optimization module. The present invention accurately analyzes the strain condition of the original workpiece corresponding to the hollow substrate of the automobile camshaft during the processing process, and realizes the optimized control of the quenching process of the hollow substrate of the automobile camshaft based on the analysis results. BRIEF DESCRIPTION OF THE DRAWINGS

[0066] To facilitate understanding by those skilled in the art, the present invention is further described below with reference to the accompanying drawings.

[0067] Figure 1 is a block diagram of the overall system of the present invention;

[0068] Figure 2 Schematic diagram of the structure of the hollow substrate of the present invention;

[0069] Figure 3 Schematic diagram of the heat treatment process in the present invention;

[0070] Figure 4 Schematic diagram of the cylindrical coordinate system of the present invention;

[0071] Figure 5 The present invention is a flow chart of the method. DETAILED DESCRIPTION

[0072] The technical solutions of the present invention will be clearly and completely described below in conjunction with the embodiments. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0073] Example 1, please refer to Figures 1-4 As shown, the technical solution provided by the present invention is: an intelligent quenching control system for a hollow substrate of an automobile camshaft. The system generates an initial heat treatment process flow based on the workpiece material type and expected processing dimensions of the original workpiece corresponding to the hollow substrate of the automobile camshaft. The system then executes the initial heat treatment process flow, analyzes the heat treatment process flow, identifies the thermal stress phase change and phase change strain corresponding to the quenching sub-process, and optimizes the quenching sub-process based on the thermal stress phase change and phase change strain, thereby realizing intelligent optimization control of the quenching process of the hollow substrate of the automobile camshaft.

[0074] In the present invention, the intelligent quenching control system includes a data acquisition module, a material analysis module, a heat treatment processing module, a quenching analysis module, a strain judgment module and a quenching optimization module;

[0075] In the present invention, the data acquisition module is used to collect the workpiece material type and expected processing dimensions of the original workpiece corresponding to the hollow substrate of the automobile camshaft, the expected processing dimensions including the outer diameter of the hollow substrate, the inner diameter of the hollow substrate, and the length of the hollow substrate; the workpiece material types include low alloy steel, ductile iron, and powder metallurgy steel;

[0076] The data acquisition module sends the workpiece material type and expected processing size of the original workpiece corresponding to the hollow substrate of the automobile camshaft to the material analysis module.

[0077] In this embodiment, the material analysis module is used to set an initial heat treatment process flow for the original workpiece corresponding to the hollow substrate of the automobile camshaft. The setting process is as follows:

[0078] Obtain the workpiece material type and expected processing dimensions of the original workpiece corresponding to the hollow substrate of the automobile camshaft, and obtain the outer diameter, inner diameter, and length of the hollow substrate;

[0079] The internal aspect ratio is obtained by dividing the length of the hollow substrate by the internal diameter of the hollow substrate; the external aspect ratio is obtained by dividing the length of the hollow substrate by the external diameter of the hollow substrate; and the aspect ratio difference is obtained by subtracting the internal aspect ratio from the external aspect ratio;

[0080] Identifying multiple historical heat treatment processing flows of the same workpiece material type stored in a database based on the workpiece material type of the hollow substrate of the automobile camshaft corresponding to the original workpiece, identifying the corresponding historical heat treatment processing flows to obtain a historical substrate outer diameter, a historical substrate inner diameter, and a historical substrate length of the hollow substrate of the automobile camshaft;

[0081] It should be noted that if Figure 3 As shown, the heat treatment process specifically includes: a first heating sub-process, a first holding sub-process, a quenching sub-process, a second heating sub-process, a second holding sub-process and an annealing sub-process; each sub-process includes an expected processing time and an expected processing temperature of the sub-process;

[0082] Similarly, calculate the historical aspect ratio difference of the hollow substrate of the automobile camshaft corresponding to the historical heat treatment process;

[0083] The matrix length similarity value is obtained by taking the absolute value of the difference between the hollow matrix length and the historical matrix length and dividing it by the hollow matrix length; the matrix aspect ratio similarity value is obtained by taking the absolute value of the difference between the aspect ratio difference and the historical aspect ratio difference and dividing it by the aspect ratio difference;

[0084] The matrix aspect ratio similarity value and the matrix length similarity value are multiplied by the corresponding proportional coefficients in sequence and then added together to obtain the corresponding processing similarity;

[0085] If any processing similarity is greater than or equal to the processing similarity threshold, the heat treatment process is sorted in descending order of processing similarity, and the historical heat treatment process at the top is selected as the corresponding heat treatment process;

[0086] If all processing similarities are less than the processing similarity threshold, the design plan of the heat treatment process is executed; in practice, a process engineer is hired to design the heat treatment process based on experience;

[0087] The material analysis module sends the heat treatment process flow of the original workpiece to the heat treatment module.

[0088] The heat treatment processing module is used to process the original workpiece according to the heat treatment processing flow. The processing process is as follows:

[0089] Obtaining the heat treatment process flow of the original workpiece, obtaining a first heating sub-process, a first holding sub-process, a quenching sub-process, a second heating sub-process, a second holding sub-process, and an annealing sub-process; the heat treatment processing module sequentially executes the above sub-processes and performs analysis when executing the quenching sub-process;

[0090] It should be explained that after the first heating sub-process, the chemical elements in the original workpiece begin to transform into austenite; and after the first holding sub-process, all the chemical elements in the original workpiece will be transformed into austenite.

[0091] In the present invention, the analysis process of the quenching sub-process is specifically as follows:

[0092] Pour quenching liquid onto the surface of the original workpiece, and measure the real-time temperature value of any spatial point of the original workpiece through the temperature measuring device;

[0093] like Figure 4 As shown in the figure, the real-time temperature field of the original workpiece in the quenching sub-process is constructed, the original workpiece is regarded as a cylindrical object, a cylindrical coordinate system corresponding to the original workpiece is established, and any spatial point on the original workpiece is recorded as P (r, θ, z);

[0094] Where r is the mirror distance, which refers to the distance from the projection point of the spatial point on the reference plane (OXY plane) to the origin, and its value is greater than zero; θ is the azimuth, which refers to the angle between the projection point and the X-axis, and its value is between 0 and 2π; z is the vertical height, which refers to the coordinate value along the z-axis;

[0095] The heat conduction control equation of the original workpiece is constructed by the heat conduction law. The heat conduction control equation is as follows:

[0096] Wherein, ρ is the material density of the original workpiece corresponding to the workpiece material type, c is the material specific heat capacity of the original workpiece corresponding to the workpiece material type; SWD is the real-time temperature value of the spatial point above the original workpiece, and SJ is the number at different times; Indicates the rate at which the workpiece's heat conduction controls the temperature change over time; RD is the thermal conductivity of the original workpiece corresponding to the workpiece material type;

[0097] is the radial heat conduction term; is the axial heat conduction term;

[0098] The expression on the left represents the thermal energy accumulation rate of the original workpiece per unit time; the expression on the right represents the net heat inflow rate caused by heat conduction to the original workpiece;

[0099] The boundary conditions of the original workpiece are constructed based on the outer diameter and the inner diameter of the hollow substrate. The boundary conditions are as follows:

[0100] External surface boundary conditions: ; In the formula, the value of r is the outer diameter of the hollow substrate divided by two; CR is the heat transfer coefficient, and WDh is the real-time ambient temperature;

[0101] The left-hand term represents the rate at which internal heat is transferred to the outer surface. The symbol indicates that the direction of heat transfer is opposite to the distribution direction of the temperature gradient (heat flows from the high temperature area to the low temperature area). The right-hand term represents the rate at which the quenching liquid removes heat from the outer surface.

[0102] Internal surface boundary conditions: ; In the formula, the value of r is the hollow inner diameter divided by two, and CRn is the internal heat transfer coefficient;

[0103] The temperature field model of the original workpiece is obtained by combining the inner surface boundary conditions, the outer surface boundary conditions and the heat conduction control equation. The temperature field model is used to describe the real-time temperature value of the original workpiece at any spatial point at any time in the quenching sub-process.

[0104] The heat treatment processing module sends the temperature field model of the original workpiece to the quenching analysis module.

[0105] In the present invention, the quenching analysis module is used to analyze the total strain generated by the original workpiece in the quenching sub-process in combination with the temperature field model. The analysis process is as follows:

[0106] Obtain the temperature field model of the original workpiece, and then obtain the real-time temperature value SWD of the original workpiece at any spatial point at any time in the quenching sub-process;

[0107] Compare the real-time temperature values ​​of the original workpiece at all spatial points in the quenching sub-process with the transformation temperature value ZWD of martensite;

[0108] It should be explained that if the real-time temperature of the original workpiece is below the transformation temperature of martensite, and under the action of a specific quenching liquid, the austenite in the original workpiece will transform into martensite with a stronger structure; the transformation temperature of martensite is determined by the type of base material and is generally 250℃-400℃;

[0109] If the real-time temperature values ​​of all spatial points are greater than the transformation temperature value of martensite, no operation is performed; if the real-time temperature value of any spatial point is less than or equal to the transformation temperature value of martensite, it is determined that the martensite transformation process has started, and the martensite transformation success rate ZHL of the original workpiece at any time during the quenching process is calculated by the formula. The specific formula is as follows:

[0110] ; In the formula, e is the natural constant, β is the material constant, obtained through experimental fitting, and is usually taken as 0.011;

[0111] Count the number of spatial points whose real-time temperature is less than or equal to the conversion temperature value, and divide the number of conversions by the total number of spatial points to get the spatial point conversion rate at the corresponding moment; when the spatial point conversion rate is less than the conversion rate threshold, no operation is performed;

[0112] When the spatial point conversion rate is greater than or equal to the conversion rate threshold, the calculation of the martensite conversion success rate is stopped, and the calculated martensite conversion success rates are summarized with the time as the number;

[0113] The total phase transformation strain of the original workpiece at the corresponding moment is obtained by multiplying the martensite transformation success rate by the spatial point transformation rate by the transformation volume expansion coefficient at the same moment;

[0114] The conversion volume expansion coefficient is a physical quantity that describes the rate of change of the element volume of the original matrix when the temperature changes; the value is usually 0.3%-0.5%;

[0115] The thermal expansion strain of any spatial point at all times is calculated by the formula. The formula for thermal expansion strain is as follows:

[0116] Thermal expansion strain = thermal expansion coefficient × (real-time temperature value - ambient temperature value); the thermal expansion relationship tree can be obtained by checking the material manual;

[0117] The total thermal strain of the original workpiece at the corresponding moment is obtained by adding up the thermal expansion strains of all spatial points;

[0118] The quenching analysis module sends the total thermal strain and the total phase change strain of the original workpiece at all times in the quenching sub-process to the strain judgment module.

[0119] In this embodiment, the strain judgment module is used to judge the total strain generated by the original workpiece in the quenching sub-process. The judgment process is as follows:

[0120] Obtain the total thermal strain and total phase transformation strain of the original workpiece at all times in the quenching sub-process;

[0121] The total phase change strain of the original workpiece is compared with the phase change strain threshold. If the total phase change strain is greater than or equal to the phase change strain threshold, a phase change adjustment signal at the corresponding moment is generated; if the total phase change strain is less than the phase change strain threshold, the process proceeds to the next step.

[0122] The total thermal strain of the original workpiece is compared with the thermal strain threshold. If the total thermal strain at any moment is greater than or equal to the thermal strain threshold, the real-time temperature values ​​of all spatial points at the corresponding moment are identified. The real-time temperature values ​​of all spatial points at the corresponding moment are added and averaged to obtain the average temperature value at the corresponding moment.

[0123] The variance of the real-time temperature values ​​corresponding to all spatial points is calculated based on the average temperature value and recorded as the variance temperature value;

[0124] The first comparison temperature value is obtained by subtracting the variance temperature value from the average temperature value, and the second comparison temperature value is obtained by adding the variance temperature value to the average temperature value; the temperature comparison interval at the corresponding moment is obtained with the first comparison temperature value as the left endpoint and the second comparison temperature value as the right endpoint;

[0125] If the real-time temperature value is outside the temperature comparison interval, the corresponding spatial point is regarded as an abnormal spatial point and a thermal strain adjustment signal is generated; if the real-time temperature value is within the temperature comparison interval, no operation is performed;

[0126] The strain judgment module sends the phase change adjustment signal, the thermal strain adjustment signal and the number of the corresponding time to the quenching optimization module;

[0127] The quenching optimization module is used to optimize the quenching sub-process. The optimization process is as follows:

[0128] Obtaining a phase change adjustment signal, a thermal strain adjustment signal, and corresponding time numbers;

[0129] Replace the operations in the quenching sub-process based on the time number;

[0130] Specifically, if the signal is for phase change adjustment, the air cooling extension method or the injection of quenching liquid through a distributed nozzle is used to achieve a smooth martensite formation rate and prevent localized violent expansion;

[0131] If it is a thermal strain adjustment signal, the temperature difference between the inner and outer surfaces is reduced by reducing the injection amount of quenching liquid and blowing it into the corresponding inner cavity of the original workpiece.

[0132] In this application, if a corresponding calculation formula appears, the above calculation formula is dimensionless and its numerical calculation is performed. The weight coefficient, proportional coefficient and other coefficients in the formula are set to a result value obtained by quantifying each parameter. Regarding the size of the weight coefficient and the proportional coefficient, as long as it does not affect the proportional relationship between the parameter and the result value, it is acceptable.

[0133] Example 2, please refer to Figure 5 As shown, based on another concept of the same invention, an intelligent quenching control method for a hollow substrate of an automobile camshaft is proposed, comprising the following steps:

[0134] Step S10, collecting the workpiece material type and expected processing size of the original workpiece corresponding to the hollow substrate of the automobile camshaft;

[0135] Step S20, setting a heat treatment process for the original workpiece corresponding to the hollow substrate of the automobile camshaft in combination with the workpiece material type and the expected processing size,

[0136] Step S30, processing the original workpiece according to the heat treatment process to obtain a temperature field model of the original workpiece;

[0137] Step S40, analyzing the total strain generated by the original workpiece in the quenching sub-process in combination with the temperature field model, and obtaining the total thermal strain and total phase transformation strain of the original workpiece at all times in the quenching sub-process;

[0138] Step S50 , judging the total strain generated by the original workpiece in the quenching sub-process, generating a phase change adjustment signal, a thermal strain adjustment signal and a corresponding time number, and optimizing the quenching sub-process according to the signal.

[0139] The preferred embodiments of the present invention disclosed above are intended only to help illustrate the present invention. These preferred embodiments do not exhaustively describe all details, nor do they limit the present invention to specific embodiments. Obviously, many modifications and variations are possible based on the contents of this specification. These embodiments are selected and described in detail in this specification to better explain the principles and practical applications of the present invention, thereby enabling those skilled in the art to better understand and utilize the present invention. The present invention is limited only by the claims and their full scope and equivalents.

Claims

1. Intelligent quenching control system for hollow substrate of automobile camshaft, characterized by: The system comprises a data acquisition module, a material analysis module, a heat treatment processing module, a quenching analysis module, a strain judgment module and a quenching optimization module. The data acquisition module is used to collect the workpiece material type and expected processing dimensions of the original workpiece corresponding to the hollow substrate of the automobile camshaft and send them to the material analysis module. The expected processing dimensions include the outer diameter of the hollow substrate, the inner diameter of the hollow substrate and the length of the hollow substrate. The workpiece material types include low alloy steel, ductile iron and powder metallurgy steel. The material analysis module is used to set an initial heat treatment processing flow for the original workpiece corresponding to the hollow substrate of the automobile camshaft and send the set heat treatment processing flow of the original workpiece to the heat treatment processing module. The working process of the material analysis module is as follows: Obtain the workpiece material type and expected processing dimensions of the original workpiece corresponding to the hollow substrate of the automobile camshaft, and obtain the outer diameter, inner diameter, and length of the hollow substrate; The internal aspect ratio is obtained by dividing the length of the hollow substrate by the internal diameter of the hollow substrate; the external aspect ratio is obtained by dividing the length of the hollow substrate by the external diameter of the hollow substrate; and the aspect ratio difference is obtained by subtracting the internal aspect ratio from the external aspect ratio; Identify multiple historical heat treatment processes of the same workpiece material type according to the workpiece material type of the hollow substrate of the automobile camshaft corresponding to the original workpiece, and obtain the historical substrate outer diameter, historical substrate inner diameter, and historical substrate length of the hollow substrate of the automobile camshaft by identifying the corresponding historical heat treatment processes; Similarly, calculate the historical aspect ratio difference of the hollow substrate of the automobile camshaft corresponding to the historical heat treatment process; The matrix length similarity value is obtained by taking the absolute value of the difference between the hollow matrix length and the historical matrix length and dividing it by the hollow matrix length; the matrix aspect ratio similarity value is obtained by taking the absolute value of the difference between the aspect ratio difference and the historical aspect ratio difference and dividing it by the aspect ratio difference; The matrix aspect ratio similarity value and the matrix length similarity value are multiplied by the corresponding proportional coefficients in sequence and then added together to obtain the corresponding processing similarity; If any processing similarity is greater than or equal to the processing similarity threshold, the heat treatment process is sorted in descending order of processing similarity, and the historical heat treatment process at the top is selected as the corresponding heat treatment process; If all processing similarities are less than the processing similarity threshold, the design plan of the heat treatment process is executed; The heat treatment processing module is used to process the original workpiece according to the heat treatment processing flow, obtain a temperature field model of the original workpiece, and send it to the quenching analysis module; the quenching analysis module is used to analyze the total strain generated by the original workpiece in the quenching sub-process in combination with the temperature field model, and obtain the total thermal strain and total phase change strain of the original workpiece at all times in the quenching sub-process and send them to the strain judgment module; The strain judgment module is used to judge the total strain generated by the original workpiece in the quenching sub-process, and send the phase change adjustment signal, thermal strain adjustment signal and corresponding time number generated by the judgment to the quenching optimization module; the quenching optimization module is used to optimize the quenching sub-process.

2. The intelligent quenching control system for the hollow substrate of an automobile camshaft according to claim 1 is characterized in that: The heat treatment process specifically includes: a first heating sub-process, a first holding sub-process, a quenching sub-process, a second heating sub-process, a second holding sub-process and an annealing sub-process. Each sub-process includes the expected processing time and expected processing temperature of the sub-process.

3. The intelligent quenching control system for the hollow substrate of an automobile camshaft according to claim 2 is characterized in that: The processing process of the heat treatment processing module is as follows: Obtaining a heat treatment process flow of the original workpiece, and obtaining a first heating sub-flow, a first holding sub-flow, a quenching sub-flow, a second heating sub-flow, a second holding sub-flow, and an annealing sub-flow; The heat treatment processing module executes the above sub-processes in sequence and performs analysis when executing the quenching sub-process; The heat conduction control equation and boundary conditions of the original workpiece are obtained through analysis. The boundary conditions include inner surface boundary conditions and outer surface boundary conditions. The temperature field model of the original workpiece is obtained by integrating the inner surface boundary conditions, outer surface boundary conditions and heat conduction control equations; wherein, the temperature field model is used to describe the real-time temperature value of the original workpiece at any spatial point at any time in the quenching sub-process.

4. The intelligent quenching control system for the hollow substrate of an automobile camshaft according to claim 3 is characterized in that: The analysis process of the quenching sub-process is specifically as follows: Pour quenching liquid onto the surface of the original workpiece and measure the real-time temperature value of any spatial point of the original workpiece; Construct the real-time temperature field of the original workpiece in the quenching sub-process, regard the original workpiece as a cylindrical object, establish a cylindrical coordinate system corresponding to the original workpiece, and record any spatial point on the original workpiece as P (r, θ, z); Where r is the mirror distance, which refers to the distance from the projection point of the spatial point on the reference plane to the origin, and its value is greater than zero; θ is the azimuth, which refers to the angle between the projection point and the X-axis, and its value is between 0 and 2π; z is the vertical height, which refers to the coordinate value along the z-axis; The heat conduction control equation of the original workpiece is constructed by the heat conduction law. The heat conduction control equation is as follows: Wherein, ρ is the material density of the original workpiece corresponding to the workpiece material type, c is the material specific heat capacity of the original workpiece corresponding to the workpiece material type; SWD is the real-time temperature value of the spatial point above the original workpiece, and SJ is the number at different times; Indicates the rate at which the workpiece's heat conduction controls the temperature change over time; RD is the thermal conductivity of the original workpiece corresponding to the workpiece material type; is the radial heat conduction term; is the axial heat conduction term; The expression on the left represents the thermal energy accumulation rate of the original workpiece per unit time; the expression on the right represents the net heat inflow rate caused by heat conduction to the original workpiece; The boundary conditions of the original workpiece are constructed based on the outer diameter and the inner diameter of the hollow substrate. The boundary conditions are as follows: External surface boundary conditions: ; In the formula, the value of r is the outer diameter of the hollow substrate divided by two; CR is the heat transfer coefficient, and WDh is the real-time ambient temperature; The left-hand term represents the rate at which internal heat is transferred to the outer surface, and the sign indicates that the direction of heat transfer is opposite to the distribution direction of the temperature gradient; the right-hand term represents the rate at which the quenching liquid removes heat from the outer surface; Internal surface boundary conditions: ; In the formula, the value of r is the hollow inner diameter divided by two, and CRn is the internal heat transfer coefficient.

5. The intelligent quenching control system for the hollow substrate of an automobile camshaft according to claim 3 is characterized in that: The analysis process of the quenching analysis module is as follows: Obtain the temperature field model of the original workpiece, and then obtain the real-time temperature value SWD of the original workpiece at any spatial point at any time in the quenching sub-process; Compare the real-time temperature values ​​of the original workpiece at all spatial points in the quenching sub-process with the transformation temperature value ZWD of martensite; If the real-time temperature values ​​of all spatial points are greater than the transformation temperature value of martensite, no operation is performed; if the real-time temperature value of any spatial point is less than or equal to the transformation temperature value of martensite, it is determined that the martensite transformation process has started, and the martensite transformation success rate ZHL of the original workpiece at any time during the quenching process is calculated by the formula. The specific formula is as follows: ; In the formula, e is the natural constant and β is the material constant; The number of conversions of spatial points whose real-time temperature value is less than or equal to the conversion temperature value is counted, and the conversion rate of the spatial point at the corresponding moment is obtained by dividing the number of conversions by the total number of spatial points.

6. The intelligent quenching control system for the hollow substrate of an automobile camshaft according to claim 5, characterized in that: The analysis process of the quenching analysis module also includes: When the spatial point conversion rate is less than the conversion rate threshold, no operation is performed; When the spatial point conversion rate is greater than or equal to the conversion rate threshold, the calculation of the martensite conversion success rate is stopped, and the calculated martensite conversion success rates are summarized with the time as the number; The total phase transformation strain of the original workpiece at the corresponding moment is obtained by multiplying the martensite transformation success rate by the spatial point transformation rate by the transformation volume expansion coefficient at the same moment; The thermal expansion strain of any spatial point at all times is calculated using the formula. The formula for thermal expansion strain is as follows: Thermal expansion strain = thermal expansion coefficient × (real-time temperature value - ambient temperature value); The total thermal strain of the original workpiece at the corresponding moment is obtained by adding up the thermal expansion strains of all spatial points.

7. The intelligent quenching control system for the hollow substrate of an automobile camshaft according to claim 6, characterized in that: The judgment process of the strain judgment module is as follows: Obtain the total thermal strain and total phase transformation strain of the original workpiece at all times in the quenching sub-process; The total phase change strain of the original workpiece is compared with the phase change strain threshold. If the total phase change strain is greater than or equal to the phase change strain threshold, a phase change adjustment signal at the corresponding moment is generated. If the total phase change strain is less than the phase change strain threshold, proceed to the next step; The total thermal strain of the original workpiece is compared with the thermal strain threshold. If the total thermal strain at any time is greater than or equal to the thermal strain threshold, the real-time temperature values ​​of all spatial points at the corresponding time are identified; The real-time temperature values ​​of all spaces at the corresponding moment are added and averaged to obtain the average temperature value at the corresponding moment; The variance of the real-time temperature values ​​corresponding to all spatial points is calculated based on the average temperature value and recorded as the variance temperature value; The first comparison temperature value is obtained by subtracting the variance temperature value from the average temperature value, and the second comparison temperature value is obtained by adding the variance temperature value to the average temperature value; The temperature comparison interval at the corresponding moment is obtained by taking the first comparison temperature value as the left endpoint and the second comparison temperature value as the right endpoint; If the real-time temperature value is outside the temperature comparison interval, the corresponding spatial point is regarded as an abnormal spatial point and a thermal strain adjustment signal is generated; if the real-time temperature value is within the temperature comparison interval, no operation is performed.

8. The intelligent quenching control system for the hollow substrate of an automobile camshaft according to claim 7, characterized in that: The optimization process of the quenching optimization module is as follows: Obtaining a phase change adjustment signal, a thermal strain adjustment signal, and corresponding time numbers; Replace the operations in the quenching sub-process based on the time number, specifically: If the signal is for phase transformation adjustment, the martensite formation rate is smoothed by extending the air cooling method or injecting quenching liquid through a distributed nozzle; If it is a thermal strain adjustment signal, the temperature difference between the inner and outer surfaces is reduced by reducing the injection amount of quenching liquid and blowing it into the corresponding inner cavity of the original workpiece.

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