Vehicle body electrophoresis film thickness determination method, device, equipment and medium

Abstract

The invention relates to the technical field of vehicle body coating treatment, and discloses a vehicle body electrophoresis film thickness determination method, device and equipment and a medium, and the method comprises the steps: obtaining a film thickness-current relation model of a non-inner cavity structure of a vehicle body; according to the film thickness-current relation model and the total electrophoresis resistance of the vehicle body, a film thickness-voltage relation model of the non-inner-cavity structure of the vehicle body is obtained, and the film thickness-current relation model is used for representing the incidence relation between the ith second electrophoresis film thickness and the ith second voltage when the electrophoresis test is conducted on the vehicle body; according to the film thickness-voltage relation model, determining a non-inner-cavity electrophoresis film thickness value of the vehicle body non-inner-cavity structure; and determining the inner cavity electrophoresis film thickness value of the vehicle body inner cavity structure according to the non-inner cavity electrophoresis film thickness value. According to the method, the design efficiency is improved, the arrangement accuracy of the electrophoresis structure of the vehicle body is also ensured, and the design cost is reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of body painting treatment, and in particular to a method, device, equipment and medium for determining the electrophoretic film thickness of a body. Background Art

[0002] Currently, in the white body design stage, the electrophoretic structure setting in body painting production is mainly designed by referring to mass-produced models. However, with the increasing diversification of current models, in the body painting production stage, once the electrophoretic structure setting of some models is insufficient, it cannot meet the electrophoretic design requirements of the body structure, resulting in problems such as unstable bath liquid parameters, shortened replacement cycle of bath liquid consumables, and poor corrosion durability caused by non-compliant body electrophoretic coatings. Moreover, for some models, it is also easy to cause over-design (such as too many openings) and improper design (such as improper openings, and additional plugs or patches are needed to block the redundant openings) of the body electrophoretic structure, which will increase the vehicle model cost. Summary of the Invention

[0003] Based on this, it is necessary to provide a method, device, equipment and medium for determining the electrophoretic film thickness of a body to solve the technical problems such as insufficient or over-design caused by referring to mass-produced models in the prior art.

[0004] A method for determining the electrophoretic film thickness of a body includes:

[0005] Obtaining a film thickness-current relationship model of the non-lumen structure of the body, where the film thickness-current relationship model is used to characterize the correlation between the electrophoretic film thickness at the i-th second and the cathode current density at the i-th second during the electrophoretic test of the body;

[0006] According to the film thickness-current relationship model and the total electrophoretic resistance of the body, obtaining a film thickness-voltage relationship model of the non-lumen structure of the body, where the film thickness-current relationship model is used to characterize the correlation between the electrophoretic film thickness at the i-th second and the voltage at the i-th second during the electrophoretic test of the body;

[0007] Determining the non-lumen electrophoretic film thickness value of the non-lumen structure of the body according to the film thickness-voltage relationship model;

[0008] Determining the lumen electrophoretic film thickness value of the lumen structure of the body according to the non-lumen electrophoretic film thickness value.

[0009] A device for determining the electrophoretic film thickness of a body includes:

[0010] A first acquisition module, configured to acquire a film thickness-current relationship model of the non-lumen structure of the body, where the film thickness-current relationship model is used to characterize the correlation between the electrophoretic film thickness at the i-th second and the cathode current density at the i-th second during the electrophoretic test of the body;

[0011] A second acquisition module, configured to obtain a film thickness-voltage relationship model of the non-luminal structure of the vehicle body according to the film thickness-current relationship model and the total electrophoretic resistance of the vehicle body, where the film thickness-current relationship model is used to characterize the correlation between the electrophoretic film thickness at the i-th second and the voltage at the i-th second during the electrophoretic test of the vehicle body;

[0012] A first determination module, configured to determine the non-luminal electrophoretic film thickness value of the non-luminal structure of the vehicle body according to the film thickness-voltage relationship model;

[0013] A second determination module, configured to determine the luminal electrophoretic film thickness value of the luminal structure of the vehicle body according to the non-luminal electrophoretic film thickness value.

[0014] A computer device includes a memory, a processor, and computer-readable instructions stored in the memory and executable on the processor. When the processor executes the computer-readable instructions, the method for determining the electrophoretic film thickness of the vehicle body is implemented.

[0015] One or more readable storage media storing computer-readable instructions, which, when executed by one or more processors, cause the one or more processors to execute the method for determining the electrophoretic film thickness of the vehicle body.

[0016] In the above method, device, equipment and medium for determining the electrophoretic film thickness of the vehicle body, the method includes: obtaining a film thickness-current relationship model of the non-luminal structure of the vehicle body, where the film thickness-current relationship model is used to characterize the correlation between the electrophoretic film thickness at the i-th second and the cathode current density at the i-th second during the electrophoretic test of the vehicle body; obtaining a film thickness-voltage relationship model of the non-luminal structure of the vehicle body according to the film thickness-current relationship model and the total electrophoretic resistance of the vehicle body, where the film thickness-current relationship model is used to characterize the correlation between the electrophoretic film thickness at the i-th second and the voltage at the i-th second during the electrophoretic test of the vehicle body; determining the non-luminal electrophoretic film thickness value of the non-luminal structure of the vehicle body according to the film thickness-voltage relationship model; determining the luminal electrophoretic film thickness value of the luminal structure of the vehicle body according to the non-luminal electrophoretic film thickness value.

[0017] The method for determining the electrophoretic film thickness of the vehicle body according to the present invention can, after determining the non-luminal electrophoretic film thickness value of the non-luminal structure of the vehicle body (i.e., the structural area corresponding to a single ideal vehicle body sheet metal surface), further determine the luminal electrophoretic film thickness value of the luminal structure of the vehicle body (i.e., the structural area corresponding to multiple sheet metals) based on the above non-luminal electrophoretic film thickness value. In this way, the electrophoretic structure setting of the vehicle body is accurately quantified and guided according to the above non-luminal electrophoretic film thickness value and luminal electrophoretic film thickness value, improving the design efficiency, ensuring the accuracy of the electrophoretic structure setting of the vehicle body, and reducing the design cost. Description of the Drawings

[0018] To more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for the description of the embodiments of the present invention. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0019] Figure 1 is a schematic flowchart of a method for determining the electrophoretic film thickness of a vehicle body according to an embodiment of the present invention;

[0020] Figure 2 is a schematic flowchart of step S20 of the method for determining the electrophoretic film thickness of a vehicle body according to an embodiment of the present invention;

[0021] Figure 3 is a schematic flowchart of step S40 of the method for determining the electrophoretic film thickness of a vehicle body according to an embodiment of the present invention;

[0022] Figure 4 is a schematic structural diagram of a device for determining the electrophoretic film thickness of a vehicle body according to an embodiment of the present invention. Specific Embodiments

[0023] The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the drawings in the embodiments of the present invention. Obviously, the described embodiments are some, but not all, of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts fall within the scope of protection of the present invention.

[0024] In one embodiment, as Figure 1 shown, a method for determining the electrophoretic film thickness of a vehicle body is provided, including the following steps S10 - S40:

[0025] S10. Obtain a film thickness - current relationship model for the non - inner cavity structure of the vehicle body. The film thickness - current relationship model is used to characterize the correlation between the electrophoretic film thickness at the i - th second (where i is any second during the electrophoretic test of the vehicle body) and the cathode current density at the i - th second during the electrophoretic test of the vehicle body. In the present invention, first, an electrophoretic test platform needs to be established to conduct an electrophoretic test on the vehicle body. At the same time, the electrophoretic film thickness at the i - th second and the cathode current density at the i - th second during the electrophoretic test of the vehicle body are measured through the electrophoretic simulation device in the electrophoretic test platform. Then, an ideal film thickness - current relationship model is established based on the electrophoretic film thickness at the i - th second and the cathode current density at the i - th second, so that the film thickness - current relationship model matches the measurement results such as the electrophoretic film thickness at the i - th second and the cathode current density at the i - th second recorded during the electrophoretic test of the vehicle body.

[0026] In one embodiment, the film thickness - current relationship model includes:

[0027] n i = A * M / (ρ 电泳层Z F) * j i

[0028] Where:

[0029] n i is the electrophoretic film thickness at the i-th second during the electrophoretic test of the vehicle body;

[0030] A is the electrophoretic solution deposition parameter; each electrophoretic solution has a fixed electrophoretic solution deposition parameter A.

[0031] M is the molar mass of the coating particles; each electrophoretic solution has a fixed molar mass of the coating particles.

[0032] ρ 电泳层 is the electrophoretic layer density; the electrophoretic layer density ρ 电泳层 is the equivalent density value per second during the electrophoretic test of the vehicle body.

[0033] Z is the number of charges of the electrode reaction; each electrophoretic solution has a fixed Z value, so Z can be regarded as a constant value.

[0034] F is the Faraday constant;

[0035] j i is the cathode current density at the i-th second; the cathode current density j at the i-th second i is equal to the quotient of the current on the cathode surface divided by the coating film area. The unit of the coating film area can be square millimeters. In one embodiment, it can be considered that the electrophoretic film thickness within each square millimeter is of equal thickness, and thus the cathode current density j at the i-th second is calculated under this ideal uniform thickness i .

[0036] In this embodiment, the electrophoretic solution can be replaced and adjusted multiple times to change the various parameters related to the electrophoretic solution. Then, after the electrophoretic solution parameters finally adjusted (such as the electrophoretic solution deposition parameter A and the molar mass M of the coating particles, etc.) are determined in this film thickness - current relationship model, the electrophoretic film thickness n at the i-th second during the electrophoretic test of the vehicle body in this film thickness - current relationship model i and the cathode current density j at the i-th second i, it can match the measurement results such as the electrophoretic film thickness at the i-th second and the cathode current density at the i-th second recorded during the electrophoretic test of the vehicle body. At this time, each parameter in the film thickness-current relationship model is the ideal value. Understandably, when replacing and adjusting the electrophoretic solution, the normal distribution value of the electrophoretic coating deposition parameter A within its corresponding numerical boundary can be calibrated and solved multiple times, and then an optimal electrophoretic coating deposition parameter can be selected based on this normal distribution value. Furthermore, based on this optimal electrophoretic coating deposition parameter, the electrophoretic solution can be further adjusted.

[0037] S20. Obtain the film thickness-voltage relationship model of the non-inner cavity structure of the vehicle body according to the film thickness-current relationship model and the total electrophoretic resistance of the vehicle body. The film thickness-current relationship model is used to characterize the correlation between the electrophoretic film thickness at the i-th second and the voltage at the i-th second during the electrophoretic test of the vehicle body. In this embodiment, the cathode current density at the i-th second, the electrophoretic film thickness at the i-th second, and the voltage at the i-th second can be measured by the electrophoretic simulation device in the electrophoretic test platform. Then, based on the cathode current density at the i-th second, the voltage at the i-th second, the electrophoretic film thickness at the i-th second, the preset fixed resistance value corresponding to the electrophoretic test of the vehicle body, etc., the film thickness-voltage relationship model can be determined.

[0038] In one embodiment, as Figure 2 shown, the step S20, that is, the step of obtaining the film thickness-voltage relationship model of the non-inner cavity structure of the vehicle body according to the film thickness-current relationship model and the total electrophoretic resistance of the vehicle body, includes the following steps S201-203:

[0039] S201. Determine the total electrophoretic resistance of the vehicle body corresponding to the i-th second according to the voltage at the i-th second and the cathode current density at the i-th second. Further, the step S201, that is, the step of determining the total electrophoretic resistance of the vehicle body corresponding to the i-th second according to the voltage at the i-th second and the cathode current density at the i-th second, includes:

[0040] Judge whether the cathode current density at the i-th second is greater than or equal to the preset minimum current density value. The preset minimum current density value is the minimum current density value at which the vehicle body can form a film. When the cathode current density at the i-th second is greater than or equal to the preset minimum current density value, the vehicle body can continuously form a film during the electrophoretic operation, and the total electrophoretic resistance of the vehicle body will continuously increase due to the increase in the electrophoretic film thickness at the i-th second (however, the preset fixed resistance value in the total electrophoretic resistance of the vehicle body is a fixed value and usually does not change). When the cathode current density at the i-th second is less than the preset minimum current density value, no more film will be formed, and the total electrophoretic resistance of the vehicle body will no longer change. Understandably, the preset minimum current density value is strongly related to the properties of the electrophoretic material, and there are obvious differences in the different specifications of electrophoretic paints produced by different electrophoretic manufacturers. Therefore, the preset minimum current density value can be set according to the actual situation.

[0041] When the cathode current density in the i-th second is greater than or equal to the preset minimum current density value, the quotient of dividing the voltage in the i-th second by the cathode current density in the i-th second is determined as the total body electrophoresis resistance corresponding to the i-th second; that is, when the cathode current density in the i-th second is greater than or equal to the preset minimum current density value, the total body electrophoresis resistance will continuously increase due to the increase in the electrophoresis film thickness in the i-th second. Therefore, at this time, it is necessary to determine the latest total body electrophoresis resistance based on the voltage in the i-th second and the cathode current density measured in real time, and then calculate the film thickness in the subsequent steps based on this total body electrophoresis resistance.

[0042] When the cathode current density in the i-th second is less than the preset minimum current density value, it is determined that the total body electrophoresis resistance corresponding to the i-th second is equal to the total body electrophoresis resistance of the previous second. That is, when the cathode current density in the i-th second is less than the preset minimum current density value, since the total body electrophoresis resistance will no longer change, only the total body electrophoresis resistance corresponding to the i-th second needs to be equal to the total body electrophoresis resistance of the previous second, and the subsequent film thickness will not change either. At this time, the calculation of the film thickness in the subsequent steps can also be aborted.

[0043] S202. Determine the electrophoresis coating resistance coefficient according to the preset fixed resistance value, the electrophoresis film thickness in the i-th second, and the total body electrophoresis resistance corresponding to the i-th second; further, before the step S202, that is, before determining the electrophoresis coating resistance coefficient according to the preset fixed resistance value, the electrophoresis film thickness in the i-th second, and the total body electrophoresis resistance corresponding to the i-th second, includes:

[0044] Determine the preset fixed resistance value according to the following preset resistance model;

[0045] R 0 = Cl + R 阴 + R 阳

[0046] Where:

[0047] R 0 is the preset fixed resistance value during the electrophoresis test of the vehicle body;

[0048] Cl is the electrophoresis bath solution resistance; where, C is the bath solution resistance coefficient; l is the minimum distance from the anode to the electrophoresis position;

[0049] R 阴 is the cathode resistance; the cathode resistance refers to the cumulative resistance of the cathode area during the electrophoresis test of the vehicle body; the cathode resistance is a fixed value related to the equipment attributes.

[0050] R 阳 is the anode resistance; the anode resistance refers to the cumulative resistance of the anode area during the electrophoresis test of the vehicle body. The anode resistance is a fixed value related to the equipment attributes.

[0051] Among them, the preset fixed resistance value can be composed of the electrophoresis bath liquid resistance, the cathode resistance, and the anode resistance. When calculating according to the steady state, during the electrophoresis operation process, all three are fixed values. Therefore, the preset fixed resistance value is also a fixed value. Understandably, in different electrophoresis production lines, there may be obvious differences in the electrophoresis bath liquid resistance, the cathode resistance, and the anode resistance. Therefore, the electrophoresis bath liquid resistance, the cathode resistance, and the anode resistance corresponding to each production line need to be measured and determined before starting the operation.

[0052] Further, step S202, that is, determining the electrophoresis coating resistance coefficient according to the preset fixed resistance value, the electrophoresis film thickness at the i-th second, and the total body electrophoresis resistance corresponding to the i-th second, includes:

[0053] Determine the electrophoresis coating resistance coefficient according to the following calculation model:

[0054] R i =B*n i+ R 0

[0055] Wherein:

[0056] n i is the electrophoresis film thickness at the i-th second during the electrophoresis test on the vehicle body;

[0057] R i is the total body electrophoresis resistance corresponding to the i-th second;

[0058] B is the electrophoresis coating resistance coefficient;

[0059] R 0 is the preset fixed resistance value during the electrophoresis test on the vehicle body.

[0060] In this embodiment, the above calculation model can be first determined according to the characteristic that the coating resistance shows a linear relationship with the increase of the electrophoresis coating film thickness. Then, the electrophoresis coating resistance coefficient is calibrated according to the above calculation model. Finally, the calculation model is made to match the correlation between the actual determined total body electrophoresis resistance corresponding to the i-th second and the electrophoresis film thickness at the i-th second in the above steps. At this time, the obtained electrophoresis coating resistance coefficient is the ideal value.

[0061] S203, determine the film thickness-voltage relationship model according to the electrophoresis coating resistance coefficient and the film thickness-current relationship model. That is, when the above film thickness-current relationship model and the electrophoresis coating resistance coefficient are both determined, the film thickness-voltage relationship model for characterizing the correlation between the electrophoresis film thickness at the i-th second and the voltage at the i-th second can be obtained according to the above film thickness-current relationship model and the electrophoresis coating resistance coefficient. Further, the film thickness-voltage relationship model includes:

[0062] B*ni ^2 + R 0 *n i -H 0 *U i =0

[0063] Wherein:

[0064] B is the electrophoretic coating resistivity;

[0065] n i is the electrophoretic film thickness at the i-th second during the electrophoretic test on the vehicle body;

[0066] R 0 is the preset fixed resistance value;

[0067] j i is the cathode current density at the i-th second;

[0068] U i is the voltage at the i-th second during the electrophoretic test on the vehicle body;

[0069] H 0 is the preset constant value; and H 0 =A*M / (ρ 电泳层Z F);

[0070] A is the electrophoretic solution deposition parameter;

[0071] M is the molar mass of the coating particles;

[0072] ρ 电泳层 is the electrophoretic layer density;

[0073] Z is the number of charges of the electrode reaction;

[0074] F is the Faraday constant.

[0075] Specifically, in the present invention, when performing a steady-state calculation on the non-lumen structure of the vehicle body, it is assumed that there is no change in the concentration of the electrophoretic solution during the electrophoretic process of the vehicle body. That is, in the above film thickness-voltage relationship model, since the electrophoretic coating resistivity B has been determined, and the preset constant value H 0以及 the preset fixed resistance value R 0 are all fixed values that can be calculated or known, the voltage at the i-th second during the electrophoretic test on the vehicle body can be measured by the electrophoretic simulation device in the electrophoretic test platform. Therefore, according to the above film thickness-voltage relationship model, the electrophoretic film thickness of each second can be calculated.

[0076] S30. Determine the non-lumen electrophoretic film thickness value of the non-lumen structure of the vehicle body according to the film thickness-voltage relationship model; wherein, the non-lumen structure of the vehicle body refers to the structural area corresponding to a single ideal vehicle body sheet metal surface (rather than multiple sheet metals).

[0077] In one embodiment, step S30, that is, determining the non-luminal electrophoretic film thickness value of the vehicle body non-luminal structure according to the film thickness-voltage relationship model, includes:

[0078] Determining the electrophoretic film thickness at the i-th second during the electrophoretic test on the vehicle body according to the film thickness-voltage relationship model; that is, in the above film thickness-voltage relationship model, since the electrophoretic coating resistance coefficient B has been determined, and the preset constant value H 0以及 Preset fixed resistance value R 0 Are all fixed values that can be calculated or known. The voltage at the i-th second during the electrophoretic test on the vehicle body can be measured by the electrophoretic simulation device in the electrophoretic test platform. Therefore, according to the above film thickness-voltage relationship model, the electrophoretic film thickness of each second of the vehicle body non-luminal structure can be calculated.

[0079] Determining the non-luminal electrophoretic film thickness value of the vehicle body non-luminal structure according to the preset accumulation model; the preset accumulation model includes:

[0080] n 1 = ∑ 0 t n i

[0081] Where:

[0082] n i Is the electrophoretic film thickness at the i-th second during the electrophoretic test on the vehicle body;

[0083] t is the total number of seconds of the electrophoretic test on the vehicle body;

[0084] n 1 Is the non-luminal electrophoretic film thickness value of the vehicle body non-luminal structure.

[0085] That is, in this embodiment, the above preset accumulation model can be obtained through linear fitting. Furthermore, according to the above preset accumulation model, the electrophoretic film thickness of each second of the vehicle body non-luminal structure calculated by the above film thickness-voltage relationship model can be accumulated to obtain the non-luminal electrophoretic film thickness value of the vehicle body non-luminal structure.

[0086] S40. Determining the luminal electrophoretic film thickness value of the vehicle body luminal structure according to the non-luminal electrophoretic film thickness value. That is, in this embodiment, based on the non-luminal electrophoretic film thickness value of the vehicle body non-luminal structure (that is, the structural area corresponding to a single ideal vehicle body sheet metal surface) calculated above, the luminal electrophoretic film thickness value of the vehicle body luminal structure (that is, the structural area corresponding to multiple sheet metals) can be further determined. Specifically, in this embodiment, the non-steady state accounting of the vehicle body structure lumen mainly considers the influence of the attenuation coefficient of the lumen electromagnetic shielding and the concentration parameter of the film-forming substance in the electrophoretic solution.

[0087] In one embodiment, as Figure 3 shown, step S40, that is, determining the internal cavity electrocoating film thickness of the vehicle body internal cavity structure according to the non-internal cavity electrocoating film thickness, includes the following steps S401-403:

[0088] S401. Determine the first internal cavity electrocoating film thickness of the vehicle body internal cavity structure according to the attenuation coefficient and the non-internal cavity electrocoating film thickness. Further, step S401 includes: determining the product of the attenuation coefficient and the non-internal cavity electrocoating film thickness as the first internal cavity electrocoating film thickness of the vehicle body internal cavity structure.

[0089] In this embodiment, since the electrocoating cations are in the cavity of the vehicle body internal cavity structure, and the cations around are all attracted by the cathode, it is difficult for the electrocoating cations to electro-migrate to the surface of the vehicle body internal cavity structure. When there are openings on the vehicle body internal cavity structure, the force balance of the electrocoating ions at the opening position is destroyed, and the electrocoating ions can swim to the surface of the vehicle body internal cavity structure. And when the size of the hole and the sheet metal gap (the gap between multiple sheets of metal) remain unchanged, there are differences in the forces at positions at different distances from the hole, so the electrocoating film thicknesses of the films at positions at different distances from the hole also have different degrees of attenuation, and the attenuation coefficient is determined according to the above attenuation degree.

[0090] Specifically, the attenuation coefficient can be measured through actual tests. The attenuation coefficient refers to the electrocoating film thickness corresponding to the position on the surface of the vehicle body internal cavity structure at a preset distance from a specific hole and the non-internal cavity electrocoating film thickness corresponding to the position on the surface of the non-internal cavity structure of the vehicle body at a preset distance from the specific hole when the size of the hole and the sheet metal gap remain unchanged.

[0091] It can be understood that referring to the attenuation coefficient table for examples of some attenuation coefficients in Table 1 below to understand the attenuation coefficient. In the present invention, an attenuation coefficient database can be established. The attenuation coefficient database stores multiple sets of attenuation data, and each set of attenuation coefficients is associated with a sheet metal gap, an opening size, and a distance from the hole (that is, "XX from the hole" in Table 1).

[0092] Table 1 Attenuation Coefficient Database

[0093]

[0094] In a further embodiment, further adjustment can be performed based on the attenuation coefficient determined above. For example, according to actual needs, the attenuation coefficient can be adjusted according to the overall voltage value or the segmented voltage value in the electrocoating operation stage.

[0095] S402. Determine the second internal cavity electrocoating film thickness of the vehicle body internal cavity structure according to the film-forming substance concentration parameter in the electrocoating solution; further, step S402 includes:

[0096] Determine the second internal cavity electrocoating film thickness of the vehicle body internal cavity structure according to the preset concentration-film thickness model; the preset concentration-film thickness model is:

[0097] n 2 = C i *b*ρ 液 / (2*ρ 电泳层 )

[0098] Where:

[0099] n 2 is the second internal cavity electrocoating film thickness of the vehicle body internal cavity structure;

[0100] C i is the film-forming substance concentration parameter in the electrocoating solution (unit: kg / m 3 );

[0101] b is the sheet metal gap;

[0102] ρ 液 is the electrocoating solution density;

[0103] ρ 电泳层 is the electrocoating layer density.

[0104] In this embodiment, the electrocoating solution concentration change (such as the film-forming substance concentration parameter in the electrocoating solution) is used to calculate the second internal cavity electrocoating film thickness. Specifically, during actual electrocoating operations, the electrocoating film thickness is actually affected not only by the Faraday electrodeposition theory but also by the electrocoating solution concentration change, and the electrocoating solution concentration change is also affected by factors such as the sheet metal gap. In this embodiment, according to the above preset concentration-film thickness model, the second internal cavity electrocoating film thickness affected by the electrocoating solution concentration change can be determined.

[0105] S403. Determine the minimum value of the first internal cavity electrocoating film thickness and the second internal cavity electrocoating film thickness as the internal cavity electrocoating film thickness value of the vehicle body internal cavity structure. That is, in this embodiment, compare the first internal cavity electrocoating film thickness and the second internal cavity electrocoating film thickness, and determine the internal cavity electrocoating film thickness value of the vehicle body internal cavity structure as the minimum value of the two.

[0106] In the present invention, after determining the accounting value (including the non-lumen electrophoresis film thickness value or / and the lumen electrophoresis film thickness value) according to the above-mentioned vehicle body electrophoresis film thickness determination method, it is possible to repeatedly adjust the electrophoresis coating resistance coefficient B, the electrophoresis liquid deposition parameter A, the preset minimum current density value, the attenuation parameter D, etc. by comparing whether the actually measured film thickness is consistent with the accounting value (in the case where there is no room for optimization in the electrophoresis setting of the vehicle body structure, but the accounting value calculated by the vehicle body electrophoresis film thickness determination method cannot meet the standard requirements), so as to make the accounting value consistent with the actually measured film thickness, and finally make the accounting values obtained by each model in the above-mentioned vehicle body electrophoresis film thickness method more accurate. This process is an optimization and correction process for each model in the vehicle body electrophoresis film thickness method, which can continuously improve the calculation accuracy.

[0107] The vehicle body electrophoresis film thickness determination method of the present invention can, after determining the non-lumen electrophoresis film thickness value of the non-lumen structure of the vehicle body (i.e., the structural area corresponding to a single ideal vehicle body sheet metal surface), further determine the lumen electrophoresis film thickness value of the lumen structure of the vehicle body (i.e., the structural area corresponding to multiple sheet metals) based on the above-mentioned non-lumen electrophoresis film thickness value. In this way, the electrophoresis structure setting of the vehicle body is accurately and quantitatively guided according to the above-mentioned non-lumen electrophoresis film thickness value and the lumen electrophoresis film thickness value, improving the design efficiency, ensuring the accuracy of the vehicle body electrophoresis structure setting, and reducing the design cost. In the present invention, by establishing a simplified model, a relatively accurate quantitative reference can be provided for the forward development of the vehicle body electrophoresis structure setting, making the use and accounting of the vehicle body electrophoresis film thickness determination method of the present invention convenient and fast, accurately guiding the electrophoresis layout scheme of the vehicle body sheet metal, and ensuring the implementation of the vehicle body electrophoresis structure setting scheme.

[0108] It should be understood that the magnitudes of the sequence numbers of the steps in the above embodiments do not mean the order of execution. The order of execution of each process should be determined according to its function and internal logic, and should not constitute any limitation to the implementation process of the embodiments of the present invention.

[0109] In one embodiment, a vehicle body electrophoresis film thickness determination device is provided, and the vehicle body electrophoresis film thickness determination device corresponds one-to-one to the vehicle body electrophoresis film thickness determination method in the above embodiment. As Figure 4 shown, the vehicle body electrophoresis film thickness determination device includes:

[0110] A first acquisition module, configured to acquire a film thickness-current relationship model of the non-lumen structure of the vehicle body, where the film thickness-current relationship model is used to characterize the correlation between the electrophoresis film thickness at the i-th second and the cathode current density at the i-th second during the electrophoresis test of the vehicle body;

[0111] A second acquisition module, configured to obtain a film thickness-voltage relationship model of the non-luminal structure of the vehicle body according to the film thickness-current relationship model and the total electrophoresis resistance of the vehicle body, where the film thickness-current relationship model is used to characterize the correlation between the electrophoresis film thickness at the i-th second and the voltage at the i-th second during the electrophoresis test of the vehicle body;

[0112] A first determination module, configured to determine the non-luminal electrophoresis film thickness value of the non-luminal structure of the vehicle body according to the film thickness-voltage relationship model;

[0113] A second determination module, configured to determine the luminal electrophoresis film thickness value of the luminal structure of the vehicle body according to the non-luminal electrophoresis film thickness value.

[0114] In the above embodiments of the present invention, after determining the non-luminal electrophoresis film thickness value of the non-luminal structure of the vehicle body (that is, the structural area corresponding to a single ideal vehicle body sheet metal surface), the luminal electrophoresis film thickness value of the luminal structure of the vehicle body (that is, the structural area corresponding to multiple sheet metals) can be further determined based on the above non-luminal electrophoresis film thickness value. In this way, the setting of the vehicle body electrophoresis structure is accurately quantified and guided according to the above non-luminal electrophoresis film thickness value and the luminal electrophoresis film thickness value, improving the design efficiency, ensuring the accuracy of the vehicle body electrophoresis structure setting, and reducing the design cost.

[0115] For the specific limitations of the vehicle body electrophoresis film thickness determination device, reference can be made to the limitations of the vehicle body electrophoresis film thickness determination method in the above text, which will not be elaborated here. Each module in the above vehicle body electrophoresis film thickness determination device can be implemented in whole or in part by software, hardware, and their combination. The above modules can be embedded in the processor of the computer device in hardware form or independent of it, or stored in the memory of the computer device in software form, so that the processor can call and execute the operations corresponding to the above modules.

[0116] In one embodiment, a computer device is provided, and the computer device can be a server. The computer device includes a processor, a memory, a network interface, and a database connected through a system bus. Among them, the processor of the computer device is used to provide computing and control capabilities. The memory of the computer device includes a non-volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system, computer-readable instructions, and a database. The internal memory provides an environment for the operation of the operating system and computer-readable instructions in the non-volatile storage medium. The network interface of the computer device is used to communicate with an external terminal through a network connection. When the computer-readable instructions are executed by the processor, a vehicle body electrophoresis film thickness determination method is implemented.

[0117] In one embodiment, a computer device is provided, including a memory, a processor, and computer-readable instructions stored in the memory and executable on the processor. When the processor executes the computer-readable instructions, the method for determining the body electrophoresis film thickness in the above embodiment is implemented. To avoid repetition, it will not be elaborated here.

[0118] In one embodiment, a computer-readable storage medium is provided. Computer-readable instructions are stored on the computer-readable storage medium. When the computer-readable instructions are executed by a processor, the method for determining the body electrophoresis film thickness in the above embodiment is implemented. To avoid repetition, it will not be elaborated here. The computer-readable storage medium can be non-volatile or volatile.

[0119] Those of ordinary skill in the art can understand that all or part of the processes in the methods of the above embodiments can be completed by instructing relevant hardware through computer-readable instructions. The computer-readable instructions can be stored in a non-volatile readable storage medium or a volatile readable storage medium. When the computer-readable instructions are executed, they can include the processes of the embodiments of the above methods. Among them, any reference to a memory, storage, database, or other medium used in the various embodiments provided in the present application can include non-volatile and / or volatile memories. Non-volatile memory can include read-only memory (ROM), programmable ROM (PROM), electrically programmable ROM (EPROM), electrically erasable programmable ROM (EEPROM), or flash memory. Volatile memory can include random access memory (RAM) or an external cache. By way of illustration and not limitation, RAM is available in various forms, such as static RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), double data rate SDRAM (DDR SDRAM), enhanced SDRAM (ESDRAM), synchronous link (Synchlink) DRAM (SLDRAM), memory bus (Rambus) direct RAM (RDRAM), direct memory bus dynamic RAM (DRDRAM), and memory bus dynamic RAM (RDRAM), etc.

[0120] Those skilled in the art can clearly understand that, for the convenience and brevity of description, only the above division of each functional unit and module is used as an example. In practical applications, the above functions can be allocated to different functional units and modules according to needs, that is, the internal structure of the device can be divided into different functional units or modules to complete all or part of the functions described above.

[0121] The above-described embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements on some of the technical features; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the various embodiments of the present invention, and should all be included within the protection scope of the present invention.

Claims

1. A method for determining the electrophoretic film thickness of a vehicle body, characterized in that, it includes: Obtain the film thickness-current relationship model of the non-inner cavity structure of the vehicle body, and the film thickness-current relationship model is used to characterize the correlation between the electrophoretic film thickness at the i-th second and the cathode current density at the i-th second during the electrophoretic test of the vehicle body; According to the film thickness-current relationship model and the total electrophoretic resistance of the vehicle body, obtain the film thickness-voltage relationship model of the non-inner cavity structure of the vehicle body, and the film thickness-current relationship model is used to characterize the correlation between the electrophoretic film thickness at the i-th second and the voltage at the i-th second during the electrophoretic test of the vehicle body; According to the film thickness-voltage relationship model, determine the non-inner cavity electrophoretic film thickness value of the non-inner cavity structure of the vehicle body; Determine the inner cavity electrophoretic film thickness value of the inner cavity structure of the vehicle body according to the non-inner cavity electrophoretic film thickness value.

2. The method for determining the electrophoretic film thickness of a vehicle body according to claim 1, characterized in that, the film thickness-current relationship model includes: n i = A * M / (ρ 电泳层Z F) * j i Where: n i The electrophoretic film thickness at the i-th second during the electrophoretic test of the vehicle body; A is the electrophoresis liquid deposition parameter; M is the molar mass of the coating particles; ρ 电泳层为 Electrophoretic layer density; Z is the number of charges of the electrode reaction; F is the Faraday constant; j i is the cathode current density at the i-th second.

3. The method for determining the electrophoretic film thickness of a vehicle body according to claim 1, characterized in that, the step of obtaining the film thickness-voltage relationship model of the non-inner cavity structure of the vehicle body according to the film thickness-current relationship model and the total electrophoretic resistance of the vehicle body includes: Determine the total electrophoretic resistance of the vehicle body corresponding to the i-th second according to the voltage at the i-th second and the cathode current density at the i-th second; Determine the electrophoretic coating resistance coefficient according to the preset fixed resistance value, the electrophoretic film thickness at the i-th second, and the total electrophoretic resistance of the vehicle body corresponding to the i-th second; Determine the film thickness-voltage relationship model according to the electrophoretic coating resistance coefficient and the film thickness-current relationship model.

4. The method for determining the electrophoretic film thickness of a vehicle body according to claim 3, characterized in that, the step of determining the total electrophoretic resistance of the vehicle body corresponding to the i-th second according to the voltage at the i-th second and the cathode current density at the i-th second includes: Judge whether the cathode current density at the i-th second is greater than or equal to the preset minimum current density value; When the cathode current density at the i-th second is greater than or equal to the preset minimum current density value, determine the quotient of dividing the voltage at the i-th second by the cathode current density at the i-th second as the total electrophoretic resistance of the vehicle body corresponding to the i-th second; When the cathode current density at the i-th second is less than the preset minimum current density value, determine that the total electrophoretic resistance of the vehicle body corresponding to the i-th second is equal to the total electrophoretic resistance of the vehicle body in the previous second.

5. The method for determining the electrophoretic film thickness of a vehicle body according to claim 3, characterized in that, the step of determining the electrophoretic coating resistance coefficient according to the preset fixed resistance value, the electrophoretic film thickness at the i-th second, and the total electrophoretic resistance of the vehicle body corresponding to the i-th second includes: Determine the electrophoretic coating resistance coefficient according to the following calculation model: R i = B * n i+ R 0 Where: n i The electrophoretic film thickness at the i-th second during the electrophoretic test of the vehicle body; R i is the total electrocoating resistance of the vehicle body corresponding to the i-th second; B is the electrophoretic coating resistance coefficient; R 0 Preset a fixed resistance value when performing an electrophoresis test on the vehicle body.

6. The method for determining the electrophoretic film thickness of a vehicle body according to claim 3, characterized in that, the film thickness-voltage relationship model includes: B*n i ^2+R 0 *n i -H 0 *U i =0 Where: B is the electrophoretic coating resistance coefficient; n i The electrophoretic film thickness at the i-th second during the electrophoretic test of the vehicle body; R 0 is a preset fixed resistance value; j i is the cathode current density at the i-th second; U i is the voltage at the i-th second during the electrocoating test of the vehicle body; H 0 is a preset constant value; and H 0 = A * M / (ρ 电泳层Z F); A is the electrophoresis liquid deposition parameter; M is the molar mass of the coating particles; ρ 电泳层 is the density of the electrophoresis layer; Z is the number of charges for the electrode reaction; F is the Faraday constant.

7. The method for determining the electrophoretic film thickness of a vehicle body according to claim 1, characterized in that, the step of determining the non-inner cavity electrophoretic film thickness value of the non-inner cavity structure of the vehicle body according to the film thickness-voltage relationship model includes: Determine the electrophoretic film thickness at the i-th second during the electrophoretic test on the vehicle body according to the film thickness-voltage relationship model; Determine the non-lumen electrophoretic film thickness value of the non-lumen structure of the vehicle body according to a preset accumulation model; the preset accumulation model includes: n 1 = ∑ 0 t n i Where: n i The electrophoretic film thickness at the i-th second during the electrophoretic test of the vehicle body; t is the total number of seconds for the electrophoretic test on the vehicle body; n 1 It is the non-cavity electrophoretic film thickness value of the non-cavity structure of the vehicle body.

8. The method for determining the electrophoretic film thickness of a vehicle body according to any one of claims 3 to 7, Characterized in that, Before determining the electrophoretic coating resistance coefficient according to the preset fixed resistance value, the electrophoretic film thickness at the i-th second, and the total electrophoretic resistance of the vehicle body corresponding to the i-th second, it includes: Determine the preset fixed resistance value according to the following preset resistance model; R 0 = Cl + R 阴 + R 阳 Where: R 0 The preset fixed resistance value during the electrocoating test for the vehicle body; Cl is the resistance of the electrophoretic bath solution; where, C is the bath solution resistance coefficient; l is the minimum distance from the anode to the electrophoretic position; R 阴 is the cathode resistance; the cathode resistance refers to the cumulative resistance of the cathode area during the electrophoretic test of the vehicle body; R 阳 is the anode resistance; the anode resistance refers to the cumulative resistance of the anode area during the electrophoretic test of the vehicle body.

9. The method for determining the electrophoretic film thickness of a vehicle body according to claim 1, Characterized in that, The step of determining the lumen electrophoretic film thickness value of the vehicle body lumen structure according to the non-lumen electrophoretic film thickness value includes: Determine the first lumen electrophoretic film thickness of the vehicle body lumen structure according to the attenuation coefficient and the non-lumen electrophoretic film thickness; Determine the second lumen electrophoretic film thickness of the vehicle body lumen structure according to the concentration parameter of the film-forming substance in the electrophoretic solution; Determine the minimum value of the first lumen electrophoretic film thickness and the second lumen electrophoretic film thickness as the lumen electrophoretic film thickness value of the vehicle body lumen structure.

10. The method for determining the electrophoretic film thickness of a vehicle body according to claim 9, Characterized in that, The step of determining the first lumen electrophoretic film thickness of the vehicle body lumen structure according to the attenuation coefficient and the non-lumen electrophoretic film thickness includes: Determine the product of the attenuation coefficient and the non-lumen electrophoretic film thickness as the first lumen electrophoretic film thickness of the vehicle body lumen structure.

11. The method for determining the electrophoretic film thickness of a vehicle body according to claim 9, Characterized in that, The step of determining the second lumen electrophoretic film thickness of the vehicle body lumen structure according to the concentration parameter of the film-forming substance in the electrophoretic solution includes: Determine the second lumen electrophoretic film thickness of the vehicle body lumen structure according to a preset concentration-film thickness model; the preset concentration-film thickness model is: n 2 = C i * b * ρ 液 / (2 * ρ 电泳层 ) Where: n 2 is the second inner cavity electrocoating film thickness of the vehicle body inner cavity structure; C i is the concentration parameter of the film-forming substance in the electrophoresis solution; b is the sheet metal gap; ρ 液 is the density of the electrophoresis solution; ρ 电泳层 is the electrophoretic layer density.

12. An apparatus for determining the electrophoretic film thickness of a vehicle body, Characterized in that, Comprises: A first acquisition module, configured to acquire a film thickness-current relationship model of the non-lumen structure of the vehicle body, where the film thickness-current relationship model is used to characterize the correlation between the electrophoretic film thickness at the i-th second and the cathode current density at the i-th second during the electrophoretic test on the vehicle body; A second acquisition module, configured to acquire a film thickness-voltage relationship model of the non-lumen structure of the vehicle body according to the film thickness-current relationship model and the total electrophoretic resistance of the vehicle body, where the film thickness-current relationship model is used to characterize the correlation between the electrophoretic film thickness at the i-th second and the voltage at the i-th second during the electrophoretic test on the vehicle body; A first determination module, configured to determine the non-lumen electrophoretic film thickness value of the non-lumen structure of the vehicle body according to the film thickness-voltage relationship model; A second determination module, configured to determine the lumen electrophoretic film thickness value of the vehicle body lumen structure according to the non-lumen electrophoretic film thickness value.

13. A computer device, comprising a memory, a processor, and computer-readable instructions stored in the memory and executable on the processor, Characterized in that, When the processor executes the computer-readable instructions, the method for determining the electrophoretic film thickness of the vehicle body according to any one of claims 1 to 11 is implemented.

14. One or more readable storage media storing computer-readable instructions, wherein when the computer-readable instructions are executed by one or more processors, the one or more processors are caused to execute the method for determining the electrophoretic film thickness of the vehicle body according to any one of claims 1 to 11.

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