An automotive panel die design method

Abstract

The present invention relates to the technical field of automotive die production, and specifically to a design method for automotive panel dies. The present invention constructs a virtual three-dimensional model containing each sub-component according to the geometric structure of the automotive panel, then establishes a finite element CAD digital model, determines the compensation coefficient, performs the first compensation on the finite element CAD digital model, and performs the second compensation on the basis of the first compensation, thereby obtaining the parameters for the design of the automotive panel die, obtaining the formed automotive panel die base material, and finally preprocessing the automotive panel die base material, followed by machining and assembly to complete the design of the automotive panel die. The method provided by the present invention processes the die surface and performs compensation, which can offset the influence caused by the deformation of the actual die, improve the cavity surface fitting degree, shorten the die debugging cycle, and reduce the die manufacturing cost.

Description

Technical Field

[0001] The invention relates to the technical field of automobile mold production, in particular to a method for designing an automobile covering part mold. Background Art

[0002] Automobile covering parts refer to the spatially shaped surface or internal parts made of metal sheets that cover the engine, chassis, and constitute the cab and body.

[0003] When stamping automobile cover parts, the mold needs to ensure that the precision of the stamped cover parts meets the design requirements and the quality is stable. However, during use, the mold will deform unevenly, causing problems such as low precision and unstable quality of the parts. Therefore, how to effectively improve the quality of automobile molds has become an important issue that needs to be urgently solved in my country's automobile mold production and processing industry.

[0004] Therefore, the present invention provides a method for designing a mold for an automobile cover, which is used to solve the above-mentioned related technical problems. Summary of the invention

[0005] The purpose of the present invention is to provide a method for designing an automobile cover mold. The method provided by the present invention can process the mold surface and perform compensation, which can offset the impact of actual mold deformation, improve the fit of the cavity surface, shorten the mold debugging cycle, and reduce the mold manufacturing cost.

[0006] To achieve the above object, the present invention provides the following technical solutions:

[0007] The present invention provides a method for designing a mold for an automobile cover, comprising the following steps:

[0008] S1. Divide the automobile cover into several sub-components according to the geometric structure of the automobile cover, and construct a virtual three-dimensional model containing each sub-component;

[0009] S2. According to the constructed virtual three-dimensional model containing each sub-component, a finite element CAD digital model is established, and a compensation coefficient is determined, and then a first compensation of the finite element CAD digital model is performed based on the compensation coefficient, and then a second compensation is performed based on the first compensation;

[0010] S3. According to the twice-compensated finite element CAD digital model, the design parameters of the automobile cover mold are obtained, the raw material is melted under high temperature and high pressure, and poured into the mold cavity, and hardened to obtain the molded automobile cover mold base material;

[0011] S4. Pre-treat the base material of the automobile cover mold, and then process and assemble it.

[0012] The further setting of the present invention is: in the step S1, the process of constructing the virtual three-dimensional model containing each sub-component is as follows:

[0013] Obtain the base points of each sub-component, and connect the adjacent base points to form a base three-dimensional model;

[0014] Compare the formed base three-dimensional model with the geometric structure of the automotive panel, and adjust the corresponding connecting lines of the base points to obtain the virtual three-dimensional model containing each sub-component.

[0015] The further setting of the present invention is: the base points include convex points, inflection points, and concave points.

[0016] The further setting of the present invention is: the adjustment of the corresponding connecting lines of the base points means adjusting the connecting lines of the base points, smoothing the surface formed by the connecting lines of the base points, and making it conform to the geometric structure of the automotive panel.

[0017] The further setting of the present invention is: in the step S2, the calculation formula of the compensation coefficient is:

[0018] ρ = (1 + ΔT × α1) / (1 + ΔT × α2), where ΔT is the temperature difference between room temperature and curing temperature, α1 is the coefficient of thermal expansion of the composite material of the automotive panel, and α2 is the coefficient of thermal expansion of the mold material.

[0019] The further setting of the present invention is: in the step S2, the calculation formula for the first compensation of the finite element CAD digital model based on the compensation coefficient is:

[0020] H1 = (ρ + 1) × H2, where ρ is the compensation coefficient and H2 is the theoretical size of the mold.

[0021] The further setting of the present invention is: in the step S4, the pre-treatment means first cleaning the base material of the automotive panel mold with a cleaning agent 3 to 4 times, then rinsing it with deionized water 2 to 4 times, and finally drying it at 30 to 40 °C for 60 to 70 minutes;

[0022] The cleaning agent is made of the following raw materials by weight: 10 to 20 parts of alkali metal salts, 8 to 12 parts of alcohol solvents, and 25 to 35 parts of deionized water;

[0023] The preparation process of the cleaning agent is as follows:

[0024] Accurately weigh the alkali metal salts, alcohol solvents, and deionized water, and place the alkali metal salts, alcohol solvents, and deionized water in a stirrer and mix them evenly;

[0025] Discharge it, and then successively go through the inspection and metering packaging processes to finally obtain the finished cleaning agent.

[0026] A further setting of the present invention is that the alkali metal salt is any one of sodium chloride, sodium sulfate decahydrate, and potassium alum dodecahydrate.

[0027] A further setting of the present invention is that the alcohol solvent is any one of 2-ethyl-1-butanol, 2-methylcyclohexanol, triethylene glycol, and triethylene glycol monomethyl ether.

[0028] A further setting of the present invention is that in the step S4, the processing process is as follows:

[0029] Milling the base material of the automotive panel die with a milling machine;

[0030] Then using a grinding device to finely grind the base material of the automotive panel die to the designed size.

[0031] Compared with the prior art, the beneficial effects of the present invention are:

[0032] The present invention will construct a virtual three-dimensional model containing each sub-component according to the geometric structure of the automotive panel, then establish a finite element CAD digital model, determine the compensation coefficient, perform the first compensation on the finite element CAD digital model, and perform the second compensation on the basis of the first compensation, so as to obtain the parameters for the design of the automotive panel die, obtain the formed base material of the automotive panel die, and finally perform pre-treatment on the base material of the automotive panel die, and then process and assemble to complete the design of the automotive panel die; the method provided by the present invention will perform the treatment of the die surface and will perform compensation, which can offset the influence brought by the actual die deformation, improve the cavity surface fitting degree, shorten the die debugging cycle, and reduce the die manufacturing cost. Description of the Drawings

[0033] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the following drawings are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained according to these drawings.

[0034] Figure 1 It is a flowchart of a method for designing an automotive panel die of the present invention. Detailed Embodiments

[0035] The following will clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present invention.

[0036] Example 1:

[0037] As Figure 1 shown, this embodiment provides a method for designing an automotive panel die, including the following steps:

[0038] S1. According to the geometric structure of the automotive panel, divide the automotive panel into several sub-parts, and construct a virtual three-dimensional model containing each sub-part.

[0039] Among them, the process of constructing the virtual three-dimensional model containing each sub-part is as follows:

[0040] Obtain the basic points of each sub-part, and connect the adjacent basic points to form a basic three-dimensional model;

[0041] Compare the formed basic three-dimensional model with the geometric structure of the automotive panel, and adjust the corresponding connecting lines of the basic points to obtain a virtual three-dimensional model containing each sub-part.

[0042] Furthermore, the basic points include convex points, inflection points, and concave points.

[0043] Adjusting the corresponding connecting lines of the basic points means adjusting the connecting lines of the basic points, smoothing the surface formed by the connecting lines of the basic points, and making it conform to the geometric structure of the automotive panel.

[0044] In this embodiment, it should be noted that when constructing the virtual three-dimensional model containing each sub-part, the movement and contact relationships between the parts of the model can be determined; the basic three-dimensional model is constructed using the basic points, and then the preliminary shape of the automotive panel is obtained. In order to reduce the error between the shape of the automotive panel and the actual situation, the corresponding connecting lines of the basic points will be adjusted to ensure the smoothness of the surface.

[0045] S2. According to the constructed virtual three-dimensional model containing each sub-part, establish a finite element CAD digital model, determine the compensation coefficient, then perform the first compensation on the finite element CAD digital model based on the compensation coefficient, and then perform the second compensation on the basis of the first compensation.

[0046] Among them, the calculation formula for the compensation coefficient is:

[0047] ρ = (1 + ΔT × α1) / (1 + ΔT × α2), where ΔT is the temperature difference between room temperature and curing temperature, α1 is the coefficient of thermal expansion of the composite material of the automotive panel, and α2 is the coefficient of thermal expansion of the die material.

[0048] The calculation formula for performing the first compensation on the finite element CAD digital model based on the compensation coefficient is:

[0049] H1 = (ρ + 1) × H2, where ρ is the compensation coefficient and H2 is the theoretical size of the die.

[0050] In this embodiment, it should be noted that if the mold material and the composite material of the automotive panel have different coefficients of thermal expansion, it will affect the shape and dimensional accuracy of the automotive panel. The thermal expansion of a mold with a small size hardly affects the composite parts, but if the mold size is too large, especially when the composite parts have important shape or assembly features, the influence caused by the different coefficients of thermal expansion between the composite material and the mold material needs to be considered. Therefore, size compensation is required during the mold design process.

[0051] In addition, the second compensation refers to increasing the size of the automotive panel mold, such as by 0.2 mm, for subsequent milling and grinding to ensure the designed size.

[0052] S3. According to the finite element CAD digital model with two compensations, obtain the parameters for the design of the automotive panel mold. Melt the raw material under high temperature and high pressure and pour it into the cavity, and harden it to obtain the formed base material of the automotive panel mold.

[0053] S4. Pretreat the base material of the automotive panel mold, and then perform reprocessing and assembly.

[0054] Among them, the pretreatment means first cleaning the base material of the automotive panel mold 3 times with a cleaning agent, then rinsing it 2 times with deionized water, and finally drying it at 30 °C for 60 min;

[0055] The cleaning agent is made from the following raw materials by weight: 10 parts of alkali metal salt, 8 parts of alcohol solvent, and 25 parts of deionized water;

[0056] The preparation process of the cleaning agent is as follows:

[0057] Accurately weigh the alkali metal salt, alcohol solvent, and deionized water, and place the alkali metal salt, alcohol solvent, and deionized water in a stirrer and mix them evenly;

[0058] Discharge it, and then successively go through the inspection and metering packaging processes to finally obtain the finished cleaning agent.

[0059] Furthermore, the alkali metal salt is selected as sodium chloride.

[0060] The alcohol solvent is selected as 2-ethyl-1-butanol.

[0061] In addition, the processing process is as follows:

[0062] Use a milling machine to perform milling on the base material of the automotive panel mold;

[0063] Then use a grinding device to finely grind the base material of the automotive panel mold to the designed size.

[0064] In this embodiment, it should be noted that the mold is cleaned with a cleaning agent to ensure the cleanliness of the mold after forming, and then reprocessed and assembled to complete the design of the automotive panel mold.

[0065] Embodiment 2:

[0066] As Figure 1 shown, this embodiment provides a method for designing an automotive panel mold, including the following steps:

[0067] S1. According to the geometric structure of the automotive panel, the automotive panel is divided into several sub-parts, and a virtual three-dimensional model containing each sub-part is constructed.

[0068] Among them, the process of constructing a virtual three-dimensional model containing each sub-part is as follows:

[0069] Obtain the basic points of each sub-part, and connect the adjacent basic points to form a basic three-dimensional model;

[0070] Compare the formed basic three-dimensional model with the geometric structure of the automotive panel, and adjust the corresponding connecting lines of the basic points to obtain a virtual three-dimensional model containing each sub-part.

[0071] Furthermore, the basic points include convex points, inflection points, and concave points.

[0072] Adjusting the corresponding connecting lines of the basic points means adjusting the connecting lines of the basic points, smoothing the surface formed by the connecting lines of the basic points, and making it conform to the geometric structure of the automotive panel.

[0073] In this embodiment, it should be noted that when constructing a virtual three-dimensional model containing each sub-part, the movement and contact relationships between the parts of the model can be determined; the basic three-dimensional model is constructed using the basic points, and then the preliminary shape of the automotive panel is obtained. In order to reduce the error between the shape of the automotive panel and the actual situation, the corresponding connecting lines of the basic points will be adjusted to ensure the smoothness of the surface.

[0074] S2. According to the constructed virtual three-dimensional model containing each sub-part, a finite element CAD digital model is established, and a compensation coefficient is determined. Then, the first compensation of the finite element CAD digital model is performed based on the compensation coefficient, and the second compensation is performed on the basis of the first compensation.

[0075] Among them, the calculation formula of the compensation coefficient is:

[0076] ρ = (1 + ΔT×α1) / (1 + ΔT×α2), where ΔT is the temperature difference between room temperature and curing temperature, α1 is the coefficient of thermal expansion of the composite material of the automotive panel, and α2 is the coefficient of thermal expansion of the mold material.

[0077] The calculation formula for the first compensation of the finite element CAD digital model based on the compensation coefficient is:

[0078] H1 = (ρ + 1) × H2, where ρ is the compensation coefficient and H2 is the theoretical size of the mold.

[0079] In this embodiment, it should be noted that if the mold material and the composite material of the automotive panel have different coefficients of thermal expansion, it will affect the shape and dimensional accuracy of the automotive panel. The thermal expansion of a mold with a smaller size hardly affects the composite parts, but if the mold size is too large, and there are important shape or assembly features in the composite parts, the influence caused by the different coefficients of thermal expansion of the composite material and the mold material needs to be considered. Therefore, size compensation is required during the mold design process.

[0080] In addition, the second compensation means increasing the size of the automotive panel mold, such as 0.2 mm, for subsequent milling and grinding to ensure the designed size.

[0081] S3. According to the finite element CAD digital model with two compensations, obtain the parameters for the design of the automotive panel mold, melt the raw material under high temperature and high pressure, and pour it into the cavity to obtain the formed automotive panel mold base material after hardening.

[0082] S4. Pretreat the automotive panel mold base material, and then perform machining and assembly.

[0083] Among them, the pretreatment means first cleaning the automotive panel mold base material 4 times with a cleaning agent, then rinsing it 3 times with deionized water, and finally drying it at 35 °C for 65 min;

[0084] The cleaning agent is made from the following raw materials by weight: 15 parts of alkali metal salt, 10 parts of alcohol solvent, and 30 parts of deionized water;

[0085] The preparation process of the cleaning agent is as follows:

[0086] Accurately weigh the alkali metal salt, alcohol solvent, and deionized water, and place the alkali metal salt, alcohol solvent, and deionized water in a stirrer and mix them evenly;

[0087] Discharge it, and then successively go through the inspection and metering packaging processes to finally obtain the finished cleaning agent.

[0088] Further, the alkali metal salt is selected as sodium sulfate decahydrate.

[0089] The alcohol solvent is selected as 2-methylcyclohexanol.

[0090] In addition, the machining process is as follows:

[0091] Milling process the automotive panel mold base material with a milling machine;

[0092] Then, use a grinding device to finely grind the base material of the automotive body panel die to the designed dimensions.

[0093] In this embodiment, it should be noted that the die is cleaned with a cleaning agent to ensure the cleanliness of the die after forming, and then reprocessed and assembled to complete the design of the automotive body panel die.

[0094] Embodiment 3:

[0095] As Figure 1 shown, this embodiment provides a design method for an automotive body panel die, including the following steps:

[0096] S1. According to the geometric structure of the automotive body panel, divide the automotive body panel into several sub-parts, and construct a virtual three-dimensional model containing each sub-part.

[0097] Among them, the process of constructing a virtual three-dimensional model containing each sub-part is as follows:

[0098] Obtain the basic points of each sub-part, and connect the adjacent basic points to form a basic three-dimensional model;

[0099] Compare the formed basic three-dimensional model with the geometric structure of the automotive body panel, and adjust the corresponding connection lines of the basic points to obtain a virtual three-dimensional model containing each sub-part.

[0100] Furthermore, the basic points include convex points, inflection points, and concave points.

[0101] Adjusting the corresponding connection lines of the basic points means adjusting the connection lines of the basic points, smoothing the surface formed by the connection lines of the basic points, and making it conform to the geometric structure of the automotive body panel.

[0102] In this embodiment, it should be noted that when constructing a virtual three-dimensional model containing each sub-part, the movement and contact relationships between various parts of the model can be determined; the basic three-dimensional model is constructed using the basic points, and then the preliminary shape of the automotive body panel is obtained. In order to reduce the error between the shape of the automotive body panel and the actual situation, the corresponding connection lines of the basic points will be adjusted to ensure the smoothness of the surface.

[0103] S2. According to the constructed virtual three-dimensional model containing each sub-part, establish a finite element CAD digital model, determine the compensation coefficient, then perform the first compensation on the finite element CAD digital model based on the compensation coefficient, and then perform the second compensation on the basis of the first compensation.

[0104] Among them, the calculation formula for the compensation coefficient is:

[0105] ρ = (1 + ΔT × α1) / (1 + ΔT × α2), where ΔT is the temperature difference between room temperature and curing temperature, α1 is the coefficient of thermal expansion of the composite material of the automotive body panel, and α2 is the coefficient of thermal expansion of the die material.

[0106] The calculation formula for the first compensation of the finite element CAD digital model based on the compensation coefficient is as follows:

[0107] H1 = (ρ + 1) × H2, where ρ is the compensation coefficient and H2 is the theoretical size of the mold.

[0108] In this embodiment, it should be noted that if the mold material and the composite material of the automotive panel have different thermal expansion coefficients, it will affect the shape and dimensional accuracy of the automotive panel. The thermal expansion of a mold with a smaller size hardly affects the composite parts, but if the mold size is too large, and there are important shape or assembly features in the composite parts, the influence caused by the different thermal expansion coefficients of the composite material and the mold material needs to be considered. Therefore, size compensation is required during the mold design process.

[0109] In addition, the second compensation refers to increasing the size of the automotive panel mold, such as 0.2 mm, for subsequent milling and grinding to ensure the design size.

[0110] S3. Obtain the parameters for the design of the automotive panel mold according to the finite element CAD digital model after two compensations, melt the raw material under high temperature and high pressure, and pour it into the cavity, and harden it to obtain the formed automotive panel mold base material.

[0111] S4. Pretreat the automotive panel mold base material, and then perform reprocessing and assembly.

[0112] Among them, the pretreatment means first cleaning the automotive panel mold base material with a cleaning agent 3 - 4 times, then rinsing it with deionized water 4 times, and finally drying it at 40 °C for 70 min;

[0113] The cleaning agent is made from the following raw materials by weight: 20 parts of alkali metal salt, 12 parts of alcohol solvent, and 35 parts of deionized water;

[0114] The preparation process of the cleaning agent is as follows:

[0115] Accurately weigh the alkali metal salt, alcohol solvent, and deionized water, and place the alkali metal salt, alcohol solvent, and deionized water in a stirrer and mix them evenly;

[0116] Discharge it, and then successively go through the inspection and metering packaging processes to finally obtain the finished cleaning agent.

[0117] Further, the alkali metal salt is selected as potassium alum.

[0118] The alcohol solvent is selected as triethylene glycol monomethyl ether.

[0119] In addition, the processing process is as follows:

[0120] Milling machining is performed on the base material of the automotive panel die using a milling machine;

[0121] Then, a grinding device is used to finely grind the base material of the automotive panel die to the designed dimensions.

[0122] In this embodiment, it should be noted that the die is cleaned using a cleaning agent to ensure its cleanliness after molding, and then reprocessed and assembled to complete the design of the automotive panel die.

[0123] In the description of this specification, the descriptions referring to terms such as "one embodiment", "example", "specific example", etc. mean that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic expressions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in a suitable manner in any one or more embodiments or examples.

[0124] The preferred embodiments of the present invention disclosed above are only used to help explain the present invention. The preferred embodiments do not elaborate on all the details, nor do they limit the invention to the specific embodiments described. Obviously, many modifications and variations can be made according to the content of this specification. These embodiments are selected and specifically described in this specification to better explain the principles and practical applications of the present invention, so that those skilled in the art can well understand and utilize the present invention. The present invention is only limited by the claims and their full scope and equivalents.

Claims

1. A method for designing a mold for an automobile cover, characterized in that: The following steps are involved: S1. Divide the automobile cover into several sub-components according to the geometric structure of the automobile cover, and construct a virtual three-dimensional model containing each sub-component; S2. According to the constructed virtual three-dimensional model containing each sub-component, a finite element CAD digital model is established, and a compensation coefficient is determined, and then a first compensation of the finite element CAD digital model is performed based on the compensation coefficient, and then a second compensation is performed based on the first compensation; The calculation formula of the compensation coefficient is: ρ=(1+ΔT×α1) / (1+ΔT×α2), where ΔT is the difference between room temperature and curing temperature, α1 is the thermal expansion coefficient of the composite material of the automotive cover, and α2 is the thermal expansion coefficient of the mold material; The calculation formula for the first compensation of the finite element CAD digital model based on the compensation coefficient is: H1=(ρ+1)×H2, where ρ is the compensation coefficient and H2 is the theoretical size of the mold; The second compensation refers to increasing the size of the automobile panel mold; S3. According to the twice-compensated finite element CAD digital model, the design parameters of the automobile cover mold are obtained, the raw material is melted under high temperature and high pressure, and poured into the mold cavity, and hardened to obtain the molded automobile cover mold base material; S4. Pre-treat the base material of the automobile cover mold, and then process and assemble it.

2. A method for designing a mold for an automobile cover according to claim 1, characterized in that: In step S1, the process of constructing a virtual three-dimensional model containing various sub-components is as follows: Obtain the basic points of each sub-component and connect adjacent basic points to form a basic three-dimensional model; The formed basic three-dimensional model is compared with the geometric structure of the automobile cover, and the corresponding basic point connection lines are adjusted to obtain a virtual three-dimensional model containing various sub-components.

3. A method for designing a mold for an automobile cover according to claim 2, characterized in that: The basic points include convex points, inflection points and concave points.

4. The method for designing a mold for an automobile cover according to claim 2, characterized in that: The adjusting of the corresponding basic point connection lines refers to adjusting the connection lines of the basic points so as to make the curved surface formed by the connection lines of the basic points smooth and consistent with the geometric structure of the automobile cover.

5. The method for designing a mold for an automobile cover according to claim 1, characterized in that: In the step S4, the pretreatment means first cleaning the automobile cover mold base material with a cleaning agent for 3 to 4 times, then rinsing it with deionized water for 2 to 4 times, and finally drying it at 30 to 40° C. for 60 to 70 minutes; The cleaning agent is made of the following raw materials in parts by weight: 10 to 20 parts of alkali metal salt, 8 to 12 parts of alcohol solvent and 25 to 35 parts of deionized water; The preparation process of the cleaning agent is as follows: Accurately weigh the alkali metal salt, alcohol solvent and deionized water, and place the alkali metal salt, alcohol solvent and deionized water in a stirrer to mix them thoroughly; The material is discharged, and then successively inspected, measured and packaged to finally obtain the finished cleaning agent.

6. A method for designing a mold for an automobile cover according to claim 5, characterized in that: The alkali metal salt is selected from any one of sodium chloride, sodium sulfate decahydrate, and potassium aluminum sulfate dodecahydrate.

7. A method for designing a mold for an automobile cover according to claim 6, characterized in that: The alcohol solvent is selected from any one of 2-ethyl-1-butanol, 2-methylcyclohexanol, triethylene glycol, and triethylene glycol monomethyl ether.

8. The method for designing a mold for an automobile cover according to claim 5, characterized in that: In step S4, the processing process is as follows: Use milling machines to mill the base material of automobile cover molds; Then use grinding equipment to finely grind the base material of the automobile cover mold to the designed size.

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