Oil sump modal and multi-rigidity collaborative design method, device and equipment

Abstract

The application is suitable for the technical field of oil pan design, and particularly relates to an oil pan modal and multi-rigidity collaborative design method, device and equipment. The method comprises the following steps: establishing an oil pan finite element model; performing modal analysis according to the finite element model to obtain the minimum order natural frequency of the oil pan; performing rigidity analysis according to the finite element model to obtain the static rigidity of multiple key points of the oil pan; obtaining a modal margin based on the minimum order natural frequency of the oil pan and the maximum excitation frequency of the engine; obtaining n rigidity margins based on the static rigidity of the multiple key points of the oil pan and the corresponding key point rigidity requirement values; jointly evaluating a design state according to the modal margin and the n rigidity margins, and modifying the finite element model according to the design state; and iterating the modified finite element model until the joint evaluation result meets the standard to obtain a final design. In the method, the problem of low design efficiency and unbalanced performance of the existing design method of the automobile oil pan can be solved.

Description

Technical Field

[0001] This application belongs to the field of oil pan design technology, and in particular relates to oil pan modal and multi-stiffness collaborative design methods, devices and equipment. Background Technology

[0002] The oil pan is a critical component of a car engine, primarily functioning to store engine oil, seal the lubrication system, and assist in heat dissipation. During engine operation, the oil pan withstands a wide frequency range of excitation from the engine (mainly the ignition frequency and its harmonics), while its flange face needs to maintain sufficient sealing pressure to prevent oil leakage. The design of the oil pan faces two main interdependent technical challenges: 1. Modal matching problem: If the lowest natural frequency of the oil pan is close to the engine's main excitation frequency (usually the ignition frequency), it will trigger structural resonance, leading to loosening of fixing bolts, gasket failure, and even fatigue cracking. To avoid resonance, engineering practices typically require the natural frequency of the oil pan to avoid the excitation frequency by a certain range (i.e., maintaining sufficient "modal margin"). 2. Local stiffness problem: The oil pan contains several functionally sensitive areas, such as the flange sealing zone, oil pump mounting point, and drain plug seat. Insufficient local static stiffness in these areas can cause excessive deformation even under quasi-static loads (such as bolt preload and oil pressure), leading to seal failure or loss of accessory installation accuracy. Furthermore, under dynamic excitation, insufficient local stiffness can exacerbate the vibration response in that area, leading to structural noise (i.e., "bulging" phenomenon).

[0003] Existing automotive oil pan design methods typically address these two issues separately, requiring repeated trial and error and resulting in low efficiency. Consequently, existing design methods suffer from low design efficiency and uneven performance. Summary of the Invention

[0004] This application provides a method, apparatus, and equipment for modal and multi-stiffness collaborative design of oil pan, which can solve the problems of low design efficiency and unbalanced performance in existing automotive oil pan design methods.

[0005] In a first aspect, embodiments of this application provide a method for collaborative design of oil pan modes and multiple stiffnesses, including: Establish a finite element model of the oil pan; Modal analysis was performed based on the finite element model to obtain the minimum natural frequency of the oil pan. Stiffness analysis is performed based on the finite element model to obtain the static stiffness of multiple key points of the oil pan; wherein, the multiple key points include at least: a sealing key point located at the midpoint of the line connecting adjacent bolt connection points on the flange face of the oil pan, and an installation key point located at the oil pump mounting point or the drain plug seat; the stiffness analysis includes: applying a test force along the failure-sensitive direction on the key point, obtaining the deformation in that direction, and obtaining the static stiffness of the corresponding key point based on the test force and the deformation; Based on the minimum natural frequency of the oil pan and the maximum excitation frequency of the engine, the modal margin is obtained; based on the static stiffness of multiple key points of the oil pan and the corresponding key point stiffness requirement values, n stiffness margins are obtained; wherein, the key point stiffness requirement values ​​are obtained by back-calculation through the functional failure boundary of the location of the key point, and the functional failure boundary includes: for the sealing key point, the maximum normal separation displacement allowed by the gasket to maintain the minimum sealing compressive stress; for the installation key point, the maximum permissible relative displacement for normal operation of the accessory; The design state is jointly evaluated based on the modal margin and n stiffness margins, and the finite element model is modified based on the design state. The modified finite element model is iterated until the joint evaluation results meet the standards, thus obtaining the final design.

[0006] The technical solutions described in this application embodiment have at least the following technical effects: The oil pan modal and multi-stiffness collaborative design method provided in this application firstly establishes a finite element model of the oil pan; this step establishes an initial finite element model of the oil pan for simulation. Secondly, modal analysis is performed based on the finite element model to obtain the minimum natural frequency of the oil pan; stiffness analysis is performed based on the finite element model to obtain the static stiffness of multiple key points of the oil pan; this step involves performing modal and stiffness analyses on the finite element model separately to obtain the minimum natural frequency and multiple key point static stiffnesses, which can represent the specific performance of the current oil pan design. Then, based on the minimum natural frequency of the oil pan and the maximum excitation frequency of the engine, modal margins are obtained; based on the multiple key point static stiffnesses of the oil pan and the corresponding key point stiffness requirements, n stiffness margins are obtained; this step compares the current minimum natural frequency of the oil pan with the maximum excitation frequency of the engine, and then compares the multiple key point static stiffnesses of the oil pan with the corresponding key point stiffness requirements to determine the modal and stiffness margins of the current oil pan design, which is used to judge whether the various performance characteristics of the current design meet the standards. Next, the design state is jointly evaluated based on the modal margin and n stiffness margins, and the finite element model is modified accordingly. In this step, the quality of the design is assessed using modal margin and stiffness margin to identify areas of design non-compliance. Finally, the modified finite element model is iterated until the joint evaluation results meet the standards, resulting in the final design. This iterative process ensures the final oil pan design meets performance standards, addressing the issues of low design efficiency and uneven performance in existing automotive oil pan design methods. In this method, a finite element model is established for simulation, followed by modal analysis to obtain the modal margin. Stiffness analysis is also performed on multiple key points of the finite element model to obtain n stiffness margins. The current design is modified using modal margin and stiffness margin, and after multiple iterations meeting the conditions, the final design is determined. This method effectively solves the problems of low design efficiency and uneven performance in existing automotive oil pan design methods.

[0007] Secondly, embodiments of this application provide an oil pan mode and multi-stiffness coordination device, comprising: Establish model elements to create a finite element model of the oil pan; The analysis unit is used to perform modal analysis based on the finite element model to obtain the minimum natural frequency of the oil pan; it is also used to perform stiffness analysis based on the finite element model to obtain the static stiffness of multiple key points of the oil pan; wherein, the multiple key points include at least: a sealing key point located at the midpoint of the line connecting adjacent bolt connection points on the flange face of the oil pan, and an installation key point located at the oil pump mounting point or the drain plug seat; the stiffness analysis includes: applying a test force along the failure-sensitive direction on the key point, obtaining the deformation in that direction, and obtaining the static stiffness of the corresponding key point based on the test force and the deformation; The margin determination unit is used to obtain the modal margin based on the minimum natural frequency of the oil pan and the maximum excitation frequency of the engine; it is also used to obtain n stiffness margins based on the static stiffness of multiple key points of the oil pan and the corresponding key point stiffness requirement values; wherein, the key point stiffness requirement values ​​are obtained by back-calculation through the functional failure boundary of the location of the key point, and the functional failure boundary includes: for the sealing key point, the maximum normal separation displacement allowed by the gasket to maintain the minimum sealing compressive stress; for the installation key point, the maximum permissible relative displacement for normal operation of the accessory; A joint evaluation unit is used to jointly evaluate the design state based on the modal margin and n stiffness margins, and modify the finite element model based on the design state; An iterative unit is used to iterate with the modified finite element model until the results of the joint evaluation meet the requirements, thus obtaining the final design.

[0008] Thirdly, embodiments of this application provide an oil pan modal and multi-stiffness cooperative device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement the method described in any of the first aspects above.

[0009] Fourthly, embodiments of this application provide a computer-readable storage medium storing a computer program that, when executed by a processor, implements the method described in any of the first aspects above.

[0010] Fifthly, embodiments of this application provide a computer program product that, when running on an oil pan modal and multi-stiffness cooperative device, causes the oil pan modal and multi-stiffness cooperative device to execute the oil pan modal and multi-stiffness cooperative design method described in any one of the first aspects.

[0011] It is understood that the beneficial effects of the second to fifth aspects mentioned above can be found in the relevant descriptions in the first aspect mentioned above, and will not be repeated here. Attached Figure Description

[0012] To more clearly illustrate the technical solutions in the embodiments of this application, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0013] Figure 1 This is a flowchart illustrating the oil pan modal and multi-stiffness collaborative design method provided in an embodiment of this application; Figure 2This is a schematic diagram of the structure of the oil pan mode and multi-stiffness cooperative device provided in the embodiments of this application; Figure 3 This is a schematic diagram of the structure of the oil pan modal and multi-stiffness collaborative device provided in the embodiments of this application. Detailed Implementation

[0014] In the following description, specific details such as particular system architectures and techniques are set forth for illustrative purposes and not for limitation, in order to provide a thorough understanding of the embodiments of this application. However, those skilled in the art will understand that this application may also be implemented in other embodiments without these specific details. In other instances, detailed descriptions of well-known systems, apparatuses, circuits, and methods have been omitted so as not to obscure the description of this application with unnecessary detail.

[0015] It should be understood that, when used in this application specification and the appended claims, the term "comprising" indicates the presence of the described features, integrals, steps, operations, elements and / or components, but does not exclude the presence or addition of one or more other features, integrals, steps, operations, elements, components and / or a collection thereof.

[0016] It should also be understood that the term “and / or” as used in this application specification and the appended claims means any combination of one or more of the associated listed items and all possible combinations, and includes such combinations.

[0017] As used in this application specification and the appended claims, the term "if" may be interpreted, depending on the context, as "when," "once," "in response to determination," or "in response to detection." Similarly, the phrase "if determined" or "if detected [the described condition or event]" may be interpreted, depending on the context, as meaning "once determined," "in response to determination," "once detected [the described condition or event]," or "in response to detection [the described condition or event]."

[0018] Furthermore, in the description of this application and the appended claims, the terms "first," "second," "third," etc., are used only to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0019] References to "one embodiment" or "some embodiments" as described in this specification mean that one or more embodiments of this application include a specific feature, structure, or characteristic described in connection with that embodiment. Therefore, the phrases "in one embodiment," "in some embodiments," "in other embodiments," "in still other embodiments," etc., appearing in different parts of this specification do not necessarily refer to the same embodiment, but rather mean "one or more, but not all, embodiments," unless otherwise specifically emphasized. The terms "comprising," "including," "having," and variations thereof mean "including but not limited to," unless otherwise specifically emphasized.

[0020] In related technologies, the design of the oil pan mainly faces the following two mutually restrictive technical challenges: 1. Modal matching problem: If the lowest natural frequency of the oil pan is close to the main excitation frequency of the engine (usually the ignition frequency), it will cause structural resonance, leading to loosening of fixing bolts, failure of gaskets, and even fatigue cracking. To avoid resonance, engineering usually requires that the natural frequency of the oil pan avoid the excitation frequency within a certain range (i.e., maintain sufficient "modal margin"). 2. Local stiffness problem: There are several functionally sensitive areas on the oil pan, such as the flange sealing strip, oil pump mounting point, and drain plug seat. When the local static stiffness of these areas is insufficient, even under quasi-static loads (such as bolt preload and oil pressure), excessive deformation may occur, leading to seal failure or loss of accessory installation accuracy. In addition, under dynamic excitation, insufficient local stiffness will also aggravate the vibration response of the area, causing structural noise (i.e., "bulging" phenomenon). Existing automotive oil pan design methods typically address these two issues separately, requiring repeated trial and error and resulting in low efficiency. Consequently, existing design methods suffer from low design efficiency and uneven performance.

[0021] To address the aforementioned issues, this application provides a method for collaborative design of oil pan modal and multi-stiffness parameters. First, a finite element model of the oil pan is established; this initial finite element model is used for simulation. Second, modal analysis is performed based on the finite element model to obtain the minimum natural frequency of the oil pan; stiffness analysis is then performed based on the finite element model to obtain the static stiffness of multiple key points of the oil pan. This step involves performing modal and stiffness analyses on the finite element model to obtain the minimum natural frequency and the static stiffness of multiple key points, which can represent the specific performance of the current oil pan design. Then, based on the minimum natural frequency of the oil pan and the maximum excitation frequency of the engine, the modal margin is obtained; based on the static stiffness of multiple key points of the oil pan and the corresponding stiffness requirements, n stiffness margins are obtained. In this step, the current minimum natural frequency of the oil pan is compared with the maximum excitation frequency of the engine, and the static stiffness of multiple key points of the oil pan is compared with the corresponding stiffness requirements to determine the modal and stiffness margins of the current oil pan design, which is used to judge whether the various performance characteristics of the current design meet the standards. Next, the design state is jointly evaluated based on the modal margin and the n stiffness margins, and the finite element model is modified according to the design state. In this step, the quality of the design is evaluated using the modal margin and stiffness margin to identify design defects. Finally, the modified finite element model is iterated until the joint evaluation result meets the standards, resulting in the final design. In this step, the above steps are iterated to ensure that the performance of the final oil pan design meets the standards, which can solve the problems of low design efficiency and uneven performance of existing automotive oil pan design methods. In this method, a finite element model is established for simulation, and then modal analysis is performed on the finite element model to obtain the modal margin. In addition, stiffness analysis is performed on multiple key points of the finite element model to obtain n stiffness margins. The current design is modified based on the modal margin and stiffness margin. After multiple iterations to meet the conditions, the final design is determined. This method can solve the problems of low design efficiency and uneven performance of existing automotive oil pan design methods.

[0022] The oil pan modal and multi-stiffness collaborative design method provided in this application embodiment can be applied to oil pan modal and multi-stiffness collaborative devices. In this case, the oil pan modal and multi-stiffness collaborative device is the execution subject of the oil pan modal and multi-stiffness collaborative design method provided in this application embodiment. This application embodiment does not impose any restrictions on the specific type of oil pan modal and multi-stiffness collaborative device.

[0023] For example, oil pan mode and multi-stiffness collaborative devices can be tablet computers, laptops, ultra-mobile personal computers (UMPCs), netbooks, personal digital assistants (PDAs), desktop computers, computers, laptops, etc.

[0024] To better understand the oil pan modal and multi-stiffness collaborative design method provided in the embodiments of this application, the specific implementation process of the oil pan modal and multi-stiffness collaborative design method provided in the embodiments of this application will be described by way of example below.

[0025] Figure 1 This illustration shows a schematic flowchart of the oil pan modal and multi-stiffness collaborative design method provided in an embodiment of this application. The oil pan modal and multi-stiffness collaborative design method includes: S100, establish the finite element model of the oil pan.

[0026] It is understandable that an initial finite element model of the oil pan is established using computer software, such as ANSYS or ABAQUS. The parameters of the initial finite element model can be the default parameters of the lightest oil pan without reinforcing ribs. Constraints are applied to the connection surfaces or connection points on the finite element model, such as applying axial constraints along the bolt direction at bolt connection points or applying normal constraints on the flange sealing strip.

[0027] S200: Modal analysis was performed using the finite element model to obtain the minimum natural frequency of the oil pan. Stiffness analysis was then performed using the finite element model to obtain the static stiffness of several key points on the oil pan. These key points include at least the sealing key point located at the midpoint of the line connecting adjacent bolt connection points on the oil pan flange face, and the installation key point located at the oil pump mounting point or drain plug seat. The stiffness analysis involved applying a test force along the failure-sensitive direction at each key point and obtaining the deformation in that direction. The static stiffness of the corresponding key point was then determined based on the test force and deformation.

[0028] It is understandable that a special constraint is first applied to the entire finite element model to approximate its stress state as if it were installed on a vehicle body. Then, modal analysis is performed on the finite element model using finite element analysis software to determine its minimum natural frequency. Similarly, after applying a special constraint to the entire finite element model, a test force is applied at this constraint point, and the displacement of the key point in the direction of the force is obtained. The static stiffness of the key point is then calculated as test force / displacement. Key points include at least the sealing key point located at the midpoint of the line connecting adjacent bolt connection points on the oil pan flange face, and the installation key point located at the oil pump mounting point or drain plug seat. These key points are prone to leakage or connection points with components and can represent the overall stiffness of the oil pan. For key points on the sealing surface, the normal (perpendicular to the sealing surface) stiffness is mainly evaluated; for the oil pump mounting point, the stiffness in the direction perpendicular to the mounting plane is mainly evaluated.

[0029] In one possible implementation, in S200, stiffness analysis is performed based on a finite element model to obtain the static stiffness of several key points of the oil pan, including: S210, apply test forces at key points of the finite element model and obtain deformation.

[0030] It is understandable that key points can include the oil pump mounting point, the drain plug seat, points on the flange sealing strip (especially corner points), and interface points connecting to the gearbox or other components. In finite element analysis software, test forces are applied to these key points, and the direction of the test force is the direction of the force when these key points oscillate in the car. For example, when the oil pump mounting point is in the car, it is mainly subjected to force along the direction perpendicular to the mounting plane. After applying test forces to the key points, the deformation in the direction of the test force is detected.

[0031] S220, the static stiffness of the corresponding key point is obtained based on the test force and deformation.

[0032] It can be understood that static stiffness = test force / displacement. The static stiffness of a key point is obtained by dividing the test force at a key point by the deformation (i.e., displacement) of that key point in the direction of the test force.

[0033] This setting allows for accurate determination of the static stiffness at a key point.

[0034] S300, based on the minimum natural frequency of the oil pan and the maximum excitation frequency of the engine, yields the modal margin. Based on the static stiffness of multiple key points of the oil pan and the corresponding key point stiffness requirements, n stiffness margins are obtained. The key point stiffness requirements are derived by inversely calculating the functional failure boundary of the location of that key point. The functional failure boundary includes: for sealing key points, the maximum normal separation displacement allowed to maintain the minimum sealing compressive stress of the gasket; for installation key points, the maximum permissible relative displacement for normal operation of the accessories.

[0035] It can be understood that the engine's maximum excitation frequency fmax = Nmax is the engine's maximum speed, O is the engine's excitation order (divided by 60 to convert the unit to "per second"), and R is half the engine stroke. The most energy-intensive and primary excitation source in excitation order O is the engine's ignition order, which is also half the engine stroke (meaning O and R usually cancel each other out). Then, the minimum natural frequency of the oil pan and the engine's maximum excitation frequency fmax are substituted into the calculation formula. Modal margin indicates the modal safety of the oil pan. The smaller the modal margin, the less safe it is (i.e., the more likely it is to resonate).

[0036] The stiffness requirement for key points can be inferred from the functional failure boundary at the location of the key point. For example, the maximum allowable normal opening displacement for a gasket to effectively seal is X1 (i.e., the gasket cannot seal if the displacement exceeds X1). Also, consider the maximum possible excitation force applied to the key point during vehicle operation (considering not only the excitation force from the vehicle engine but also the excitation force during severe vehicle vibrations; this can be a large value, such as 3 to 5 times the average force). Through finite element analysis, the normal stiffness required for the normal opening displacement of the gasket to be less than or equal to X1 can be obtained; this normal stiffness is the stiffness requirement for the key point. Substituting the static stiffness of n key points with their corresponding stiffness requirement values ​​into the calculation formula... Stiffness margin (kact refers to the static stiffness of the critical point, and kreq refers to the stiffness requirement value) yields n stiffness margins. The stiffness margin represents the degree of stiffness safety of the critical point. The smaller the stiffness margin, the less stiff the oil pan is, which may lead to accidents such as oil leakage or structural fracture.

[0037] In one possible implementation, within S300, based on the static stiffness of multiple key points of the oil pan and the corresponding key point stiffness requirements, n stiffness margins are obtained, including: S310, the stiffness requirement value of the key point is inferred by back-calculating the functional failure boundary of the key point location.

[0038] It is understandable that each critical point has its own functional failure boundary X1. For example, the functional failure boundary X1 of the oil pump mounting point is the maximum allowable deformation of the oil pump mounting point in the direction of the test force (if it is greater than the maximum deformation, the oil pump cannot be stably installed on the mounting point). Then, the maximum excitation force is applied to the critical point, and through finite element analysis, the normal stiffness required to make the normal opening displacement of the sealing gasket less than or equal to X1 is obtained. This normal stiffness is the stiffness requirement value of the critical point.

[0039] S320, determine the stiffness margin of the key points based on the static stiffness and stiffness requirement values ​​of the key points.

[0040] It is understandable that the static stiffness of the key points and the corresponding stiffness requirement values ​​are substituted into the calculation formula. The stiffness margin (kact refers to the static stiffness of the critical point, and kreq refers to the stiffness requirement) is used to obtain the stiffness margin. The stiffness margin represents the degree of stiffness safety of the critical point. The smaller the stiffness margin, the less stiff the oil pan is, which may lead to accidents such as oil leakage or structural fracture. Performing this operation on n critical points yields the stiffness margin of n critical points.

[0041] With this setting, the stiffness margin of n key points can be accurately obtained.

[0042] S400 evaluates the design state based on modal margin and n stiffness margins, and modifies the finite element model according to the design state.

[0043] It is understandable that combining modal margin and stiffness margin to evaluate the design state of the current finite element model allows setting respective thresholds (all greater than 0) for the modal margin and n stiffness margins. When both the modal margin and the n stiffness margins are greater than their respective thresholds, the current design is considered safe, meaning the oil pan will not resonate or leak under extreme conditions. When the modal margin or any stiffness margin fails to meet the threshold, it indicates a design flaw, and the finite element model is then modified accordingly. If the modal margin fails to meet the threshold, it signifies a risk of resonance, which can be addressed by altering the overall mass distribution or overall stiffness of the oil pan, such as by adding reinforcing ribs or increasing the plate thickness. If the stiffness margin fails to meet the threshold, it signifies a risk of localized leakage or fracture (the n stiffness margins correspond to n key points, and also to the local areas where these key points are located), which can be addressed by adjusting the local stiffness, such as by thickening local reinforcing ribs or increasing the fillet radius. When neither the modal margin nor at least one stiffness margin is met, it is treated as a failure of the modal margin. The risk of resonance is eliminated first, and then the risk of failure of the stiffness margin is eliminated in the next iteration.

[0044] In one possible implementation, in S400, the design state is jointly evaluated based on the modal margin and n stiffness margins, and the finite element model is modified according to the design state, including: S410 sets respective compliance thresholds for modal margin and n stiffness margins. All compliance thresholds are greater than 0. Compliance is defined as the modal margin or stiffness margin exceeding its corresponding compliance threshold.

[0045] It is understandable that a threshold is set for modal margin, and all thresholds are greater than 0. When the modal margin or stiffness margin is greater than the corresponding threshold, it is considered to be compliant. When the modal margin is greater than the threshold, it means that the natural frequencies of the finite element model being designed are sufficiently large, and there is enough margin. Then, thresholds are set for each of the n stiffness margins. When the stiffness margin is greater than the corresponding threshold, it means that the stiffness of the key points is sufficient to maintain stability.

[0046] S420: When the modal margin is not up to standard, the overall mass distribution and overall stiffness of the finite element model are adjusted to increase the natural frequency of the finite element model.

[0047] It is understandable that when the modal margin is not up to standard, it means that the natural frequency of the finite element model is not high enough. Therefore, the overall mass distribution and overall stiffness of the finite element model need to be adjusted to increase the natural frequency of the finite element model. The most direct way to adjust the overall mass distribution and overall stiffness is to add reinforcing ribs or thicken the outer shell plate of the oil pan.

[0048] S430: When the modal margin meets the standard but the arbitrary stiffness margin does not meet the standard, the local stiffness of the key point corresponding to the non-compliant stiffness margin is adjusted to increase the stiffness of the key point.

[0049] It is understandable that when the modal margin meets the standard but the arbitrary stiffness margin does not, it means that the natural frequency of the finite element model meets the standard but the local stiffness does not meet the standard. Therefore, stiffeners are added or the shell plate of the local area is thickened. The local area refers to the area where the stiffness margin does not meet the standard, so as to increase the stiffness of the key point.

[0050] This setup clarifies the order of modal margin and stiffness margin. When the modal margin is not up to standard, the modal margin is addressed first, and only after the modal margin meets the standard is the stiffness margin addressed. This allows for more accurate modification of the finite element model based on the design conditions.

[0051] Optionally, the method also includes: S440, when performing overall stiffness adjustment or local stiffness adjustment, the adjustment amount is proportional to the first difference. The first difference is the absolute value of the difference between the substandard modal margin or stiffness margin and the corresponding acceptable threshold.

[0052] It is understandable that the substandard modal margin or stiffness margin must be less than the corresponding compliance threshold. Therefore, the first difference = |substandard margin - compliance threshold| = compliance threshold - substandard margin. When adjusting the overall stiffness or local stiffness (i.e., when adding stiffeners to the whole or local area), the adjustment amount is proportional to the first difference (i.e., the thickness or width of the stiffener is proportional to the first difference).

[0053] This setting allows for a clear determination of the adjustment amount for overall stiffness adjustment or local stiffness adjustment.

[0054] Optionally, the method also includes: S450 When the modal margin and arbitrary stiffness margin are both substandard, the overall mass distribution and overall stiffness of the finite element model are adjusted, and the adjustment range includes the key points corresponding to the substandard stiffness margin.

[0055] It is understandable that when the modal margin and arbitrary stiffness margin are both substandard, it means that the natural frequency of the finite element model in the current design is not high enough and the local stiffness is also insufficient. Therefore, when adjusting the overall mass distribution and overall stiffness of the finite element model, the adjustment range should include the key points corresponding to the substandard stiffness margin, so as to adjust the overall stiffness and local stiffness at the same time.

[0056] With this setting, when neither the modal margin nor the arbitrary stiffness margin is up to standard, the adjustment range of the overall stiffness adjustment or mass distribution adjustment includes the key points corresponding to the unsatisfactory stiffness margin, so that the overall stiffness adjustment and local stiffness adjustment can be performed simultaneously, which can effectively shorten the time required to adjust the finite element model.

[0057] S500 uses the modified finite element model iteratively until the joint evaluation results meet the standards, thus obtaining the final design.

[0058] It is understandable that the modified finite element model is iterated and the steps from S200 to S400 are repeated until the design state obtained by the joint evaluation of the S400 step is qualified, and then the current finite element model is used as the final design.

[0059] This setup involves establishing a finite element model for simulation, performing modal analysis on the finite element model to obtain modal margins, and conducting stiffness analysis on multiple key points of the finite element model to obtain n stiffness margins. The current design is modified based on the modal margins and stiffness margins. After multiple iterations to meet the conditions, the final design is determined. This approach can solve the problems of low design efficiency and uneven performance in existing automotive oil pan design methods.

[0060] Optionally, the method also includes: S610, obtains the oil level in the oil pan.

[0061] It is understandable that the maximum amount of engine oil a different oil pan design can hold is different. When there are multiple oil pans of the same volume, the one that can hold more engine oil will have its natural frequency affected to a greater extent (resulting in a lower natural frequency). That is, the oil capacity carrying ratio = maximum engine oil volume / oil pan volume. The higher the oil capacity carrying ratio, the lower the natural frequency of the oil pan.

[0062] S620, the minimum natural frequency is corrected according to the oil level load ratio.

[0063] It is understandable that when there is a large amount of engine oil in the oil pan, the influence of engine oil mass must be considered when taking into account the mass distribution of the oil pan. This mass distribution significantly affects the magnitude of the minimum natural frequency. Therefore, it is necessary to correct the minimum natural frequency based on the oil volume ratio. The correction factor K for the minimum natural frequency of the oil pan with different oil volume ratios can be verified through physical experiments. The corrected minimum natural frequency = K × the original minimum natural frequency.

[0064] This setting allows for consideration of the maximum amount of engine oil that different oil pans can hold, and the minimum natural frequency can be adjusted accordingly.

[0065] Optionally, the method also includes: S630 uses different materials to construct the oil pan, resulting in a variety of final designs with different materials, and determines the cost and weight of the final designs with different materials.

[0066] It is understandable that common materials for manufacturing oil pans include aluminum alloys, steel plates, and composite materials. The main structure of the oil pan includes the shell, reinforcing ribs, and flange edges. By constructing the main structure of the oil pan with different materials and implementing this method, the final design of multiple different materials can be determined, and the cost and weight of the final design of multiple different materials can be evaluated based on the amount of materials used and the process.

[0067] S640 determines different biases in the final design based on the cost and weight of various materials used in the final design.

[0068] It is understandable that different types of cars have different priorities when it comes to oil pan design. For example, high-end cars focus more on quietness and weight reduction, while economy cars focus more on cost. Therefore, based on the cost and weight of the final design using various materials, a cost-to-weight ratio is constructed, and then different cost-to-weight ratios are constructed to determine the final design with different priorities.

[0069] This design takes into account the priorities of different types of cars, allowing for the selection of a more suitable final design.

[0070] It should be understood that the sequence number of each step in the above embodiments does not imply the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of this application.

[0071] Corresponding to the oil pan modal and multi-stiffness collaborative design method described in the above embodiments, this application also provides an oil pan modal and multi-stiffness collaborative device, the various units of which can realize the various steps of the oil pan modal and multi-stiffness collaborative design method. Figure 2 The diagram shows a structural block diagram of the oil pan mode and multi-stiffness coordination device provided in the embodiments of this application. For ease of explanation, only the parts related to the embodiments of this application are shown.

[0072] Reference Figure 2 The device includes: Establish model elements to create a finite element model of the oil pan; The analysis unit is used to perform modal analysis based on the finite element model to obtain the minimum natural frequency of the oil pan; it is also used to perform stiffness analysis based on the finite element model to obtain the static stiffness of multiple key points of the oil pan; wherein, the multiple key points include at least: the sealing key point located at the midpoint of the line connecting adjacent bolt connection points on the flange face of the oil pan, and the installation key point located at the oil pump mounting point or the drain plug seat; the stiffness analysis includes: applying a test force along the failure-sensitive direction on the key point, obtaining the deformation in that direction, and obtaining the static stiffness of the corresponding key point based on the test force and deformation. The margin determination unit is used to obtain the modal margin based on the minimum natural frequency of the oil pan and the maximum excitation frequency of the engine; it is also used to obtain n stiffness margins based on the static stiffness of multiple key points of the oil pan and the corresponding key point stiffness requirement values; wherein, the key point stiffness requirement value is obtained by back-calculation through the functional failure boundary of the location of the key point, and the functional failure boundary includes: for sealing key points, the maximum normal separation displacement allowed for the gasket to maintain the minimum sealing compressive stress; for installation key points, the maximum permissible relative displacement for the normal operation of the accessory; The joint evaluation unit is used to jointly evaluate the design state based on the modal margin and n stiffness margins, and modify the finite element model according to the design state. The iterative unit is used to iterate with the modified finite element model until the joint evaluation results meet the requirements and the final design is obtained.

[0073] It should be noted that the information interaction and execution process between the above-mentioned units are based on the same concept as the method embodiments of this application. For details on their specific functions and technical effects, please refer to the method embodiments section, which will not be repeated here.

[0074] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the above-described division of functional units is used as an example. In practical applications, the above functions can be assigned to different functional units as needed, that is, the internal structure of the device can be divided into different functional units to complete all or part of the functions described above. The functional units in the embodiments can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit. Furthermore, the specific names of the functional units are only for easy differentiation and are not intended to limit the scope of protection of this application. The specific working process of the units in the above system can be referred to the corresponding process in the foregoing method embodiments, and will not be repeated here.

[0075] This application also provides an oil pan mode and multi-stiffness cooperative device. Figure 3 This is a schematic diagram of the structure of an oil pan modal and multi-stiffness cooperative device provided in an embodiment of this application. Figure 3 As shown, the oil pan modal and multi-stiffness cooperative device 4 of this embodiment includes: at least one processor 40 ( Figure 3 Only one is shown in the image), at least one memory 41 ( Figure 3 (Only one is shown in the image) and a computer program 42 stored in the at least one memory 41 and executable on the at least one processor 40. When the processor 40 executes the computer program 42, it causes the oil pan modal and multi-stiffness coordinating device 4 to implement the steps in any of the above embodiments of the oil pan modal and multi-stiffness coordinating design method, or causes the oil pan modal and multi-stiffness coordinating device 4 to implement the functions of each unit in the above embodiments of the device.

[0076] For example, the computer program 42 may be divided into one or more units, which are stored in the memory 41 and executed by the processor 40 to complete this application. The one or more units may be a series of computer program instruction segments capable of performing specific functions, which describe the execution process of the computer program 42 in the oil pan modal and multi-stiffness cooperative device 4.

[0077] The oil pan modal and multi-stiffness coordination device 4 can be a microcontroller, microprocessor, mobile phone, tablet computer, wearable device, vehicle-mounted device, laptop computer, ultra-mobile personal computer (UMPC), netbook, personal digital assistant (PDA), desktop computer, smart screen, smart TV, or handheld device with wireless communication capabilities. The oil pan modal and multi-stiffness coordination device 4 may include, but is not limited to, processor 40 and memory 41. Those skilled in the art will understand that... Figure 3 This is merely an example of the oil pan mode and multi-stiffness cooperative device 4, and does not constitute a limitation on the oil pan mode and multi-stiffness cooperative device 4. It may include more or fewer components than shown, or combine certain components, or different components, such as input / output devices, network access devices, buses, etc.

[0078] The processor 40 can be a Central Processing Unit (CPU), but it can also be other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. The general-purpose processor can be a microprocessor or any conventional processor.

[0079] In some embodiments, the memory 41 may be an internal storage unit of the oil pan modal and multi-stiffness cooperative device 4, such as a hard disk or memory of the oil pan modal and multi-stiffness cooperative device 4. In other embodiments, the memory 41 may be an external storage device of the oil pan modal and multi-stiffness cooperative device 4, such as a plug-in hard disk, smart media card (SMC), secure digital (SD) card, flash card, etc., equipped on the oil pan modal and multi-stiffness cooperative device 4. Further, the memory 41 may include both internal storage units and external storage devices of the oil pan modal and multi-stiffness cooperative device 4. The memory 41 is used to store operating systems, applications, bootloaders, data, and other programs, such as the program code of computer programs. The memory 41 can also be used to temporarily store data that has been output or will be output.

[0080] This application also provides a computer-readable storage medium storing a computer program that, when executed by a processor, implements the steps in any of the above method embodiments.

[0081] This application provides a computer program product that, when run on an oil pan mode and multi-stiffness cooperative device, enables the oil pan mode and multi-stiffness cooperative device to implement the steps in any of the above method embodiments.

[0082] If the integrated unit is implemented as a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, all or part of the processes in the methods of the above embodiments of this application can be implemented by a computer program instructing related hardware. The computer program can be stored in a computer-readable storage medium, and when executed by a processor, it can implement the steps of the various method embodiments described above. The computer program includes computer program code, which can be in the form of source code, object code, executable files, or certain intermediate forms. The computer-readable medium can include at least: any entity or device capable of carrying computer program code to the oil pan modal and multi-stiffness cooperative device, a recording medium, a computer memory, a read-only memory (ROM), a random access memory (RAM), an electrical carrier signal, a telecommunication signal, and a software distribution medium. Examples include USB flash drives, portable hard drives, magnetic disks, or optical disks.

[0083] In the above embodiments, the descriptions of each embodiment have different focuses. For parts that are not described in detail or recorded in a certain embodiment, please refer to the relevant descriptions of other embodiments.

[0084] Those skilled in the art will recognize that the units and algorithm steps of the various examples described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application.

[0085] In the embodiments provided in this application, it should be understood that the disclosed oil pan modal and multi-stiffness collaborative design method, oil pan modal and multi-stiffness collaborative device, and oil pan modal and multi-stiffness collaborative equipment can be implemented in other ways. For example, the oil pan modal and multi-stiffness collaborative design method, oil pan modal and multi-stiffness collaborative device, and oil pan modal and multi-stiffness collaborative equipment embodiments described above are merely illustrative. For example, the division of units is merely a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the displayed or discussed mutual coupling or direct coupling or communication connection may be an indirect coupling or communication connection through some interfaces, devices, or units, and may be electrical, mechanical, or other forms.

[0086] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0087] The above-described embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application, and should all be included within the protection scope of this application.

Claims

1. A method for collaborative design of oil pan modes and multiple stiffnesses, characterized in that, The method includes: Establish a finite element model of the oil pan; Modal analysis was performed based on the finite element model to obtain the minimum natural frequency of the oil pan. Stiffness analysis is performed based on the finite element model to obtain the static stiffness of multiple key points of the oil pan; wherein, the multiple key points include at least: a sealing key point located at the midpoint of the line connecting adjacent bolt connection points on the flange face of the oil pan, and an installation key point located at the oil pump mounting point or the drain plug seat; the stiffness analysis includes: applying a test force along the failure-sensitive direction on the key point, obtaining the deformation in that direction, and obtaining the static stiffness of the corresponding key point based on the test force and the deformation; Based on the minimum natural frequency of the oil pan and the maximum excitation frequency of the engine, the modal margin is obtained; based on the static stiffness of multiple key points of the oil pan and the corresponding key point stiffness requirement values, n stiffness margins are obtained; wherein, the key point stiffness requirement values ​​are obtained by back-calculation through the functional failure boundary of the location of the key point, and the functional failure boundary includes: for the sealing key point, the maximum normal separation displacement allowed by the gasket to maintain the minimum sealing compressive stress; for the installation key point, the maximum permissible relative displacement for normal operation of the accessory; The design state is jointly evaluated based on the modal margin and n stiffness margins, and the finite element model is modified based on the design state. The modified finite element model is iterated until the joint evaluation results meet the standards, thus obtaining the final design.

2. The oil pan modal and multi-stiffness collaborative design method as described in claim 1, characterized in that, The stiffness analysis based on the finite element model yields the static stiffness of several key points of the oil pan, including: Test forces were applied to key points of the finite element model, and deformation was obtained. The static stiffness of the corresponding key point is obtained based on the test force and the deformation.

3. The oil pan modal and multi-stiffness collaborative design method as described in claim 1, characterized in that, Based on the static stiffness of multiple key points of the oil pan and the corresponding key point stiffness requirements, n stiffness margins are obtained, including: The stiffness requirement value of the key point is inferred by working backward from the functional failure boundary of the location of the key point. The stiffness margin of the key point is determined based on the static stiffness and stiffness requirement value of the key point.

4. The oil pan modal and multi-stiffness collaborative design method as described in claim 1, characterized in that, The step of jointly evaluating the design state based on the modal margin and n stiffness margins, and modifying the finite element model based on the design state, includes: Set respective compliance thresholds for the modal margin and the n stiffness margins; wherein, all compliance thresholds are greater than 0, and the condition is defined as compliance when the modal margin or stiffness margin is greater than the corresponding compliance threshold; When the modal margin is not up to standard, the overall mass distribution and overall stiffness of the finite element model are adjusted to increase the natural frequency of the finite element model. When the modal margin meets the standard and any stiffness margin does not meet the standard, the local stiffness of the key point corresponding to the non-compliant stiffness margin is adjusted to increase the stiffness of the key point.

5. The oil pan modal and multi-stiffness collaborative design method as described in claim 4, characterized in that, The method further includes: When adjusting the overall stiffness or local stiffness, the adjustment amount is proportional to the first difference; wherein, the first difference is the absolute value of the difference between the substandard modal margin or stiffness margin and the corresponding compliance threshold.

6. The oil pan modal and multi-stiffness collaborative design method as described in claim 4, characterized in that, The method further includes: When neither the modal margin nor any of the stiffness margins meets the requirements, the overall mass distribution and overall stiffness of the finite element model are adjusted, and the adjustment range includes the key points corresponding to the non-compliant stiffness margins.

7. The oil pan modal and multi-stiffness collaborative design method as described in claim 1, characterized in that, The method further includes: Obtain the oil volume carrying capacity ratio of the oil pan; The minimum natural frequency is corrected based on the oil volume carrying ratio.

8. The oil pan modal and multi-stiffness collaborative design method as described in claim 1, characterized in that, The method further includes: The oil pan is constructed with different materials to obtain a variety of final designs with different materials, and the cost and weight of the final designs with different materials are determined. The final design with different biases is determined based on the cost and weight of the final design using various different materials.

9. A pan mode and multi-stiffness coordination device, characterized in that, The device includes: Establish model elements to create a finite element model of the oil pan; The analysis unit is used to perform modal analysis based on the finite element model to obtain the minimum natural frequency of the oil pan; it is also used to perform stiffness analysis based on the finite element model to obtain the static stiffness of multiple key points of the oil pan; wherein, the multiple key points include at least: a sealing key point located at the midpoint of the line connecting adjacent bolt connection points on the flange face of the oil pan, and an installation key point located at the oil pump mounting point or the drain plug seat; the stiffness analysis includes: applying a test force along the failure-sensitive direction on the key point, obtaining the deformation in that direction, and obtaining the static stiffness of the corresponding key point based on the test force and the deformation; The margin determination unit is used to obtain the modal margin based on the minimum natural frequency of the oil pan and the maximum excitation frequency of the engine; it is also used to obtain n stiffness margins based on the static stiffness of multiple key points of the oil pan and the corresponding key point stiffness requirement values; wherein, the key point stiffness requirement values ​​are obtained by back-calculation through the functional failure boundary of the location of the key point, and the functional failure boundary includes: for the sealing key point, the maximum normal separation displacement allowed by the gasket to maintain the minimum sealing compressive stress; for the installation key point, the maximum permissible relative displacement for normal operation of the accessory; A joint evaluation unit is used to jointly evaluate the design state based on the modal margin and n stiffness margins, and modify the finite element model based on the design state; An iterative unit is used to iterate with the modified finite element model until the results of the joint evaluation meet the requirements, thus obtaining the final design.

10. A pan mode and multi-stiffness coordination device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, When the processor executes the computer program, it implements the method as described in any one of claims 1 to 8.

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