CN116738740B - Structure optimization method and device for large die casting - Google Patents

Abstract

The disclosure relates to a method and a device for optimizing a structure of a large die casting, wherein the method comprises the following steps: dividing the large die casting into a plurality of optimized areas; acquiring material mechanical property information in each optimized region; and optimizing the structure of the large die casting according to the material mechanical property information of the plurality of optimizing areas and the optimizing areas. According to the technical scheme, the structure of the large die casting is optimized according to the material mechanical property information of the plurality of optimized areas and the optimized areas, so that the structural design is more refined extremely, redundant design is avoided, the weight reduction of the structure is facilitated, and related problems are at least partially solved.

Description

Structure optimization method and device for large die casting

Technical Field

The disclosure relates to the technical field of structural optimization, in particular to a structural optimization method and device for a large die casting.

Background

At present, research on integrated large die castings is mainly focused on heat treatment-free die casting material research and design research of a junction frame, and in the related technology, each manufacturer takes the large die castings as a whole for consideration when in structural design and CAE (computer aided engineering) analysis, namely, the mechanical properties of materials of the large die castings are the same, so that the CAE analysis of the large die castings is not accurate enough, redundant design exists in the structural design, and the structural light-weight target cannot be met.

Disclosure of Invention

The invention aims to provide a structure optimization method and device for a large die casting, and the method optimizes the structure of the large die casting according to a plurality of optimization areas and material mechanical property information of the optimization areas, so that the structural design is more refined and extremely, redundant design is avoided, the weight reduction of the structure is facilitated, and related problems are at least partially solved.

In order to achieve the above object, the present disclosure provides a structure optimization method of a large die casting, the method comprising:

dividing the large die casting into a plurality of optimized areas;

acquiring material mechanical property information in each optimized region;

and optimizing the structure of the large die casting according to the material mechanical property information of the plurality of optimizing areas and the optimizing areas.

Optionally, the dividing the large die casting into a plurality of optimized areas includes:

obtaining structural characteristics of a large die casting, and determining a first preset optimization area according to the structural characteristics of the large die casting;

acquiring process characteristics of the large die casting, and determining a second preset optimization area according to the process characteristics of the large die casting;

and determining a plurality of optimized areas according to the first preset optimized area and the second preset optimized area.

Optionally, the determining the first preset optimizing area according to the structural feature of the large die casting includes:

acquiring a connection state of the structural feature in a whole vehicle state and a performance requirement corresponding to the structural feature;

performing performance analysis on the large die casting in a whole vehicle state according to the connection state and the performance requirement;

and determining a first preset optimization area according to the connection state and the performance analysis result.

Optionally, the performance analysis of the large die casting under the whole vehicle state according to the connection state and the performance requirement includes:

carrying out simulation analysis on the large die casting in the whole vehicle state; and/or

And carrying out whole-vehicle actual experimental analysis on the large die casting in a whole-vehicle state.

Optionally, the performance analysis includes: at least one of collision analysis, durability analysis, modal analysis, connection analysis, and sealing analysis.

Optionally, the obtaining the process feature of the large die casting, and determining the second preset optimization area according to the process feature of the large die casting includes:

acquiring casting process parameters, a mould structure and a pouring system design of a large die casting;

casting simulation is carried out according to casting process parameters, a mold structure and casting system design;

And determining a second preset optimization area according to casting process parameters, the mold structure and casting system design and casting simulation results.

Optionally, the determining the second preset optimizing area according to the casting process parameters, the mold structure, the casting system design and the casting simulation result includes:

obtaining thickness sizes of different positions of the large die casting;

obtaining the distances between different positions of the large die casting and the pouring gate;

determining the flow position of the casting material at the same moment by using casting simulation;

determining a mechanical property distribution diagram of the large die casting according to thickness sizes of different positions of the large die casting, distances between different positions and a pouring gate and flowing positions of pouring materials at the same moment;

and determining a second preset optimization area according to the mechanical property distribution diagram.

Optionally, the casting process parameters include: injection speed, mold locking force, mold temperature, vacuum degree and material composition.

Optionally, the optimizing the structure of the large die casting according to the material mechanical property information of a plurality of optimizing areas and optimizing areas includes:

establishing a CAE model of the large die casting according to the material mechanical property information of the plurality of optimized areas and the optimized areas;

And optimizing the structure of the large die casting by using the CAE model of the large die casting.

Optionally, the optimizing the structure of the large die casting by using the CAE model of the large die casting includes:

optimizing the thickness in the optimized region of the large die casting;

the number and arrangement of the reinforcing ribs in the optimization area of the large die casting are optimized.

The present disclosure also provides a structure optimization device of a large die casting, the device comprising:

the dividing module is used for dividing the large die casting into a plurality of optimized areas;

the acquisition module is used for acquiring the material mechanical property information in each optimized area;

and the optimizing module is used for optimizing the structure of the large die casting according to the material mechanical property information of the optimizing areas.

According to the technical scheme, namely the structural optimization method of the large die casting, the large die casting is divided into a plurality of optimization areas, material mechanical property information in each optimization area is acquired, area division is carried out according to the characteristics of a die casting process and the structural characteristics of the large die casting, namely, the respective material mechanical properties are given to different optimization areas of the large die casting, and the large die casting is divided into a plurality of modularized areas, so that CAE modeling is more accurate and simulation analysis is more accurate; and optimize the structure of the said big die casting according to the material mechanical property information of a plurality of optimization areas and optimization area, make the structural design refine extremely more, avoid redundant design, help the light weight of the structure.

Additional features and advantages of the present disclosure will be set forth in the detailed description which follows.

Drawings

The accompanying drawings are included to provide a further understanding of the disclosure, and are incorporated in and constitute a part of this specification, illustrate the disclosure and together with the description serve to explain, but do not limit the disclosure. In the drawings:

FIG. 1 is a flow chart of a method of structural optimization of a large die casting provided by some embodiments of the present disclosure;

FIG. 2 is a flow chart of dividing a large die casting into a plurality of optimized regions provided by some embodiments of the present disclosure;

FIG. 3 is a flow chart of determining a first predetermined optimization zone based on structural features of a large die casting provided by some embodiments of the present disclosure;

FIG. 4 is a flow chart for acquiring process features of a large die casting and determining a second predetermined optimization zone based on the process features of the large die casting provided by some embodiments of the present disclosure;

FIG. 5 is a flow chart of determining a second predetermined optimization zone based on casting process parameters, mold structure, and casting system design and casting simulation results provided by some embodiments of the present disclosure;

FIG. 6 is a flow chart of optimizing the structure of the large die casting based on a plurality of optimization regions and material mechanical property information for the optimization regions provided by some embodiments of the present disclosure;

FIG. 7 is a block diagram of an integral die cast body rear floor provided by some embodiments of the present disclosure;

FIG. 8 is a side view of an integrally die-cast body rear floor provided by some embodiments of the present disclosure;

fig. 9 is an enlarged view of a portion a based on fig. 8;

FIG. 10 is a top view of an integral die cast body rear floor provided by some embodiments of the present disclosure;

FIG. 11 is a schematic structural view of an integrally die-cast body rear floor dividing a plurality of optimized regions provided by some embodiments of the present disclosure, wherein the figure is a side view;

FIG. 12 is a schematic view of a unitary die-cast body rear floor dividing a plurality of optimized regions provided in accordance with some embodiments of the present disclosure, wherein the view is a top view;

FIG. 13 is a schematic illustration of a model of an integrally die-cast body rear floor dividing a plurality of optimization zones provided by some embodiments of the present disclosure, wherein the illustration is a side view;

FIG. 14 is a schematic illustration of a model of an integrally die-cast body rear floor dividing a plurality of optimization zones provided by some embodiments of the present disclosure, wherein the illustration is a top view;

fig. 15 is a block diagram of a structural optimization device for large die castings provided by some embodiments of the present disclosure.

Description of the reference numerals

1-a longitudinal beam; 11-middle and rear sections of the longitudinal beams; 111-a stringer body; 111 a-roof side rail; 111 b-lower side beams; 111 c-an intermediate beam; 112-a stiffener structure; 112 a-a first stiffener; 112 b-a second stiffener; 12-a front section of the longitudinal beam; 2-wheel cover; 21-the rear section of the wheel cover; 21 a-a damper mount; 22-front section of wheel cover; 22 a-a body portion; 22 b-a flanging part; 3-front cross beam; 4-a middle cross beam; 5-a rear cross beam; 6-floor panels;

100-a first region; 110-region one; 120-region two; 200-a second region; 210-region three; 220-region four; 220 a-partition one; 220 b-partition two; 300-a third region; 400-fourth region;

700-a structure optimizing device of a large die casting; 710-partitioning module; 720-an acquisition module; 730-optimization module.

Detailed Description

Specific embodiments of the present disclosure are described in detail below with reference to the accompanying drawings. It should be understood that the detailed description and specific examples, while indicating and illustrating the disclosure, are not intended to limit the disclosure.

In the present disclosure, unless otherwise indicated, terms of orientation such as "front and rear" are used generally to refer to the front and rear of a vehicle that is conveniently driven, to refer to the interior and exterior of the outline of the corresponding component, and to refer to the distance from the corresponding structure or component or another structure or component; in addition, it should be noted that terms such as "first, second", etc. are used to distinguish one element from another element without order or importance. In addition, in the description with reference to the drawings, the same reference numerals in different drawings denote the same elements.

As shown in fig. 1 to 9, the present disclosure provides a structural optimization method for a large die casting, which can be applied to a large high-pressure aluminum thin-wall structural member of an automobile body, and can also be extended to other fields, and all the large high-pressure aluminum thin-wall structural members can be structurally optimized by adopting the method, such as a large battery pack thin-wall high-pressure aluminum casting shell, an integrated automobile body rear floor, an integrated aluminum casting subframe and the like.

As shown in fig. 1, in order to achieve the above object, the present disclosure provides a structure optimizing method of a large die casting, the method comprising:

s110, dividing the large die casting into a plurality of optimized areas.

S120, acquiring material mechanical property information in each optimized area.

S130, optimizing the structure of the large die casting according to the material mechanical property information of the plurality of optimized areas and the optimized areas.

According to the technical scheme, namely the structural optimization method of the large die casting, the large die casting is divided into a plurality of optimization areas, and then material mechanical property information in each optimization area is acquired, for example, area division is carried out according to the characteristics of a die casting process and the structural characteristics of the large die casting, namely, the respective material mechanical properties are given to different optimization areas of the large die casting, and the large die casting is divided into a plurality of modularized areas, so that CAE modeling is more accurate and simulation analysis is more accurate; and optimize the structure of the said big die casting according to the material mechanical property information of a plurality of optimization areas and optimization area, make the structural design refine extremely more, avoid redundant design, help the light weight of the structure.

It should be noted that, the structure of optimizing the big die casting includes optimizing the concrete structure in each optimizing area, including the thickness of big die casting in each optimizing area, the quantity of strengthening rib, the arrangement mode of strengthening rib for structural optimization can modularization, and is more pointed, improves and optimizes the precision.

As shown in fig. 2, in some embodiments, the step of dividing the large die casting into a plurality of optimized regions includes:

s210, obtaining structural features of the large die casting, and determining a first preset optimization area according to the structural features of the large die casting.

S220, obtaining the process characteristics of the large die casting, and determining a second preset optimization area according to the process characteristics of the large die casting.

S230, determining a plurality of optimized areas according to the first preset optimized area and the second preset optimized area.

According to the structural characteristics of the large die casting, the structural characteristics of the large die casting can be obtained, a plurality of first preset optimizing areas of the large die casting are determined according to the areas where the structural characteristics are located, meanwhile, the process characteristics of the large die casting can be obtained according to the die casting process characteristics of the large die casting, a plurality of second preset optimizing areas of the large die casting are determined according to the process characteristics, the first preset optimizing areas and the second preset optimizing areas are different, the positions of the first preset optimizing areas and the second preset optimizing areas are different, the number of the second preset optimizing areas can be different, the area range of the first preset optimizing areas needs to be adjusted based on the first preset area, the area range is enlarged and reduced, and the adjusted area range is the optimizing area.

As shown in fig. 3, in some embodiments, the step of determining the first preset optimized region according to the structural feature of the large die casting includes:

s310, acquiring the connection state of the structural feature in the whole vehicle state and the performance requirement corresponding to the structural feature.

S320, performing performance analysis on the large die casting under the whole vehicle state according to the connection state and the performance requirement.

S330, determining a first preset optimization area according to the connection state and the performance analysis result.

According to the structural characteristics of a large die casting, the performance requirements of each area structure are divided from the whole vehicle angle, the integral die casting type rear floor of the vehicle body is taken as an example for illustration, and the structural characteristics of the integral die casting type rear floor of the vehicle body mainly comprise a longitudinal beam 1, a damper seat 21a, a wheel cover 2, a wheel cover flanging, a front cross beam 3, a middle cross beam 4, a rear cross beam 5 and a floor panel 6, wherein the damper seat 21a is used for connecting a damper, and the main corresponding performance requirements are structural durability and modal requirements; the longitudinal beam 1 is used for installing an auxiliary frame and bearing collision, and the main corresponding performance requirements are rear collision safety and structural durability; the main corresponding performance requirements of the wheel cover 2 are to meet the modal requirements; the flange of the wheel cover is riveted with the reinforcing plate of the vehicle body, and the main corresponding performance requirement is that the SPR riveting requirement is met; the front cross beam 3 is used for fixing the battery pack, and the main corresponding performance requirement is structural durability; the main corresponding performance requirements of the floor panel 6 are to meet the modal and sealing requirements.

Corresponding connection performance tests can be carried out on connection states of all structural features in the integral die-casting type automobile body rear floor and other structures of the automobile body, for example, riveting tests are carried out on wheel cover flanging, and cracking conditions of the wheel cover flanging are obtained. And performing a back collision test, a durability test, a modal test and a sealing test on the integrated die-casting type automobile body back floor in the whole automobile state, or performing one or more performance analyses of back collision simulation, durability simulation, modal simulation and sealing simulation on the integrated die-casting type automobile body back floor. And dividing a first preset optimization area according to the connection state of the structural characteristics and other structures of the vehicle body and the performance analysis result.

It can be understood that the preliminary region division can be performed on the large die casting according to each structural feature, and different performance analysis results, such as a stress diagram, a strain diagram, a displacement diagram, a damage value distribution diagram, a modal analysis diagram and the like, are obtained by combining each performance analysis corresponding to each structural feature, and the preliminary region division is adjusted by using the performance analysis results, wherein the adjustment can refer to the principle that the stress, the strain, the displacement, the damage or the modal results are the same or similar, and the first preset optimized region is obtained by the adjustment.

It should be noted that, specific test and simulation may refer to test conditions, methods and software known in the related art, and will not be described herein.

Optionally, the performance analysis corresponding to the structural feature may include: at least one of collision analysis, durability analysis, modal analysis, connection analysis, and sealing analysis. The performance analysis is not limited to the above types, and for the large die casting, according to the use environment or working condition, technical specifications and requirements in the field, other types of performance analysis can be performed, and those skilled in the art can select according to actual requirements, so that details are not repeated here.

Optionally, the step of performing performance analysis on the large die casting under the whole vehicle state according to the connection state and the performance requirement includes:

carrying out simulation analysis on the large die casting in the whole vehicle state; and/or carrying out whole-vehicle actual experimental analysis on the large die casting in a whole-vehicle state.

In some embodiments of the present disclosure, the performance analysis may be obtained through a simulation analysis of a large die casting in a complete vehicle state, for example, a collision simulation performance analysis, a endurance fatigue simulation performance analysis, a modal simulation performance analysis, and the like. Taking an integral die-casting type automobile body rear floor as an example, the performance analysis can comprise a rear collision simulation in a whole automobile state and a endurance fatigue simulation in the whole automobile state, cloud patterns corresponding to the simulation analysis are obtained on a computer, and the obtained cloud patterns are utilized to adjust preliminary region division obtained by structural features so as to obtain a first preset optimization region.

In other embodiments of the present disclosure, the performance analysis may be obtained through an actual test analysis of the large die casting in the whole vehicle state, for example, a collision test performance analysis, a endurance fatigue test performance analysis, a modal test performance analysis, and the like. Taking an integral die-casting type automobile body rear floor as an example, performance analysis can comprise a rear collision test in a whole automobile state and a endurance fatigue test in the whole automobile state, the results of corresponding test analysis are obtained in the modes of deformation of an actual workpiece and pasting of a strain gauge, the results include but are not limited to deformation, stress, strain and the like, and the primary area division obtained by structural characteristics is adjusted by utilizing the results, so that a first preset optimized area can be obtained.

In other embodiments of the present disclosure, the preliminary region division obtained by the structural features may be adjusted by combining the simulation analysis and the test analysis results to obtain the first preset optimized region, and the division manner may be used to combine the simulation and the test results to improve the accuracy of the region division.

As shown in fig. 4, in some embodiments, the step of obtaining the process characteristics of the large die casting and determining the second preset optimized region according to the process characteristics of the large die casting includes:

S410, obtaining casting process parameters, a mold structure and a pouring system design of the large die casting.

S420, performing casting simulation according to casting process parameters, a mold structure and casting system design.

S430, determining a second preset optimization area according to casting process parameters, mold structures and casting system design and casting simulation results.

As the characteristics of the die casting process can be known, the performances of the corresponding positions of the large die castings, which are close to the pouring gate and correspond to the main pouring runner and the secondary pouring runner, are different, the first preset optimization area can be optimized and adjusted according to the casting process characteristics of the large die castings on the basis of dividing the areas according to the structural characteristics, and the accuracy of area division is further improved.

The process characteristics of the large die casting can comprise casting process references, a mold structure, a pouring system design structure and the like, wherein the process references mainly comprise injection speed, mold locking force, mold temperature, vacuum degree, material composition and the like; the die structure can meet the requirement of the die casting production of the large die casting, is matched with the design of a pouring system, is usually designed in advance, and mainly influences the positions of pouring gates, primary pouring runners and secondary pouring runners, so that the performances of different positions of the large die casting are influenced, and comprehensive consideration is needed. Under the condition of acquiring casting process references, mold structures and casting system designs, corresponding CAE modeling is carried out, simulation of the casting process is carried out according to the casting process references, the mold structures and the casting system designs can be combined according to simulation results, thicknesses of different positions of the large die castings, distances from pouring gates, positions of materials in a main pouring runner or a secondary pouring runner and pouring simulation (namely, positions of the materials at the same moment) are obtained, the thicknesses are the same, the distances from the pouring gates are the same, the positions of the pouring materials at the same pouring runner and the same moment can be regarded as similar or approximate material properties, and the large die castings can be used as a reference for regional division.

It should be noted that, the performance difference corresponding to different thicknesses and the performance difference at different flow points should be fully considered, and the performance change caused by the process characteristics may be determined according to the content of patent publication No. CN114487337B, and the patent name "test method for verifying a sample piece and a die-casting material for die-casting manufacturability" or may be adaptively adjusted based thereon to obtain the product.

Based on the technological characteristics of the large die casting, the performance of the position close to the pouring gate is higher than that of the position far from the pouring gate, the performance of the main pouring runner is higher than that of the secondary pouring runner, the thickness and the flow length (the distance from the pouring gate) of the large die casting are different, and the corresponding performances are different, so that the difference of the performances corresponding to the different thicknesses and the difference of the performances at different flow points are fully considered, and the performance change caused by the technological characteristics can be determined according to the patent 'test piece and test method for verifying the die casting manufacturability' of CN 114487337B.

The method is characterized in that the optimization region division is performed on the premise that the requirements of the whole vehicle are optimized and met, meanwhile, the casting manufacturability is met, in the optimization region division process, the region division is performed under the condition that the performance analysis under the whole vehicle state is met, for example, the conditions of collision analysis, durability analysis, modal analysis, connection analysis, sealing analysis and the like are met, and the optimization adjustment of the region is performed after the casting technology characteristics are considered, namely, the first preset optimization region is adaptively adjusted through the second preset optimization region on the basis of the first preset optimization region.

As shown in fig. 5, in some embodiments, the determining the second preset optimized region according to the casting process parameters, the mold structure, and the casting system design and the casting simulation result includes:

s510, obtaining thickness dimensions of different positions of the large die casting.

S520, obtaining the distances from different positions of the large die casting to the pouring gate.

S530, determining the flow position of the casting material at the same moment by using casting simulation.

S540, determining a mechanical property distribution diagram of the large die casting according to thickness dimensions of different positions of the large die casting, distances between different positions and a pouring gate and flowing positions of pouring materials at the same time.

S550, determining a second preset optimization area according to the mechanical property distribution diagram.

The thickness sizes of different positions of the large die casting can be obtained through the structure of the large die casting, and can also be obtained through casting simulation; the distances between different positions of the large die casting and the pouring gate can be obtained through the design of a die structure and a pouring system, the flowing position of the pouring material at the same moment can be determined through combining pouring simulation, in the pouring simulation, the flowing position of the pouring material at the same moment can be intercepted, under the condition that the pouring speed is the same, the distances between the flowing position of the pouring material and the pouring gate at the same moment can be considered to be the same, the corresponding mechanical properties of the materials can be the same or similar, and the materials can be divided into one region, so that a mechanical property distribution diagram of the large die casting is obtained, and a second preset region can be determined according to the mechanical property distribution diagram.

It can be appreciated that in large die castings, the positions of the same structural features are generally required to be the same or similar, and in combination with the characteristics of die casting production, in order to meet the above-mentioned performance is the same or similar, when the die design and the pouring system design are to be performed, the positions of the same or similar flow lengths are generally the same, so that the second preset optimizing region of the present disclosure is free from disorder in a larger range, even if a small part of the second preset optimizing region is obviously different from other regions or unreasonable, the second preset optimizing region can be deleted or adjusted according to the actual situation, and the adaptability adjustment is performed under the condition that the integral structure of the first preset optimizing region is not affected, thereby guaranteeing the overall vehicle performance and the casting process characteristics.

The step of determining the mechanical property distribution map of the large die casting according to the thickness sizes of different positions of the large die casting, the distances between different positions and the pouring gate and the flowing positions of the pouring material at the same moment is determined by combining the content of patent publication No. CN114487337B, patent name test method for verifying the die casting process sample and the die casting material and the simulation of the large die casting. That is, test pieces of the same casting material as large die castings, different thicknesses and different distances from the pouring gate can be manufactured by the method disclosed in the patent, and then the corresponding mechanical properties of the materials can be obtained by a performance test method.

Under the condition that the first preset optimizing area is known, the second preset optimizing area is combined to adjust the range of the first preset optimizing area, so that the range of the first preset optimizing area can meet the whole vehicle state and the casting process characteristics, and the accuracy of structure optimization is improved.

In other embodiments, when the first preset optimizing area is known, an area with the same or similar thickness to the certain optimizing area around the certain optimizing area in the first preset optimizing area may be adjusted and combined into the optimizing area, an area with the same or similar distance from the certain optimizing area around the certain optimizing area to the pouring gate may also be adjusted and combined into the optimizing area, and of course, an area with the same or similar flow position of the casting material at the same time around the certain optimizing area in the first preset optimizing area may also be adjusted and combined into the optimizing area. And then, determining a second preset optimization area by combining the mechanical property distribution diagram to optimize, and adjusting the first preset optimization area.

Optionally, the casting process parameters include, but are not limited to, injection speed, mold clamping force, mold temperature, vacuum degree, and material composition, and may be other parameters that may affect the performance of the large die casting, which will not be described in detail herein.

As shown in fig. 6, in some embodiments, the optimizing the structure of the large die casting according to the material mechanical property information of the plurality of optimized regions and the optimized region includes:

s610, a CAE model of the large die casting is built according to the material mechanical property information of the plurality of optimized areas and the optimized areas.

S620, optimizing the structure of the large die casting by using the CAE model of the large die casting.

The large die casting is divided into a plurality of optimized areas, the material mechanical property information of each optimized area is determined, the CAE model of the large die casting is suggested by utilizing the optimized areas and the corresponding material mechanical property information, and the CAE model can be used for optimizing the structural characteristics of different areas of the large die casting through simulation analysis, so that the large die casting can be optimized integrally or locally, and the optimization is not limited to the uniform material mechanical property, so that the optimization is more accurate, and the lightweight design is realized more easily.

Optionally, the optimizing the structure of the large die cast part using the CAE model of the large die cast part may include: optimizing the thickness in the optimized region of the large die casting; the number and arrangement of the reinforcing ribs in the optimization area of the large die casting are optimized. The thickness of the large die casting can be optimized, the number or arrangement mode of the reinforcing ribs in a certain area can be optimized, for example, the thickness can be further reduced for an area with relatively low mechanical property requirements, the number and arrangement mode of the reinforcing ribs can be reduced, and the method can also comprise optimizing the rib lifting height of the reinforcing ribs.

According to the structural optimization method of the large die casting, CAE modeling is more accurate; the CAE simulation analysis is more accurate; the structural design of the integrated large die casting is more extreme; the performance of the integrated large die casting can more accurately meet the performance requirement of the whole vehicle; the manufacturability of the integrated large die casting fully considers the modularization performance (namely, different optimized areas endow different mechanical properties of materials), so that the process debugging target can be more accurate.

As shown in fig. 7 to 14, the present disclosure describes in detail a structural optimization method of a large die cast by taking an integrally die cast vehicle body rear floor as an example:

as shown in fig. 7 to 10, the vehicle body rear floor is characterized in terms of its structural characteristics, and may include, for example, a side member 1, a wheel cover 2, a damper seat 21a, a wheel cover flange, a front cross member 3, a center cross member 4, a rear cross member 5, and a floor panel 6.

The performance requirements of the area structure where each structural feature is located are divided from the whole vehicle angle, for example, the longitudinal beam 1 and the rear cross beam 5 meet the requirements of rear collision safety and structural durability, the castings at the shock absorber seat 21a meet the requirements of structural durability and modal, the wheel cover flanging meets the requirements of SPR riveting, the wheel cover 2 meets the requirements of modal, the front cross beam 3 and the middle cross beam 4 meet the requirements of modal and structural durability, and the floor panel 6 meets the requirements of modal and sealing; and carrying out simulation analysis on the whole vehicle state through the structural characteristics and the corresponding performance requirements to obtain a first preset optimization area.

Based on the process characteristics of the large die casting, the performance of the position close to the pouring gate is higher than the performance of the position far away from the pouring gate, the performance of the main pouring runner is higher than the performance of the secondary pouring runner, the performance difference corresponding to different thicknesses and the performance difference at different flows are fully considered, and the performance change caused by the process characteristics can be determined according to the content of patent publication No. CN114487337B, test method for verifying test pieces and die casting materials for die casting manufacturability, so as to determine a second preset optimizing area.

According to the technical characteristics, the integral large die casting is subjected to modularized performance division, namely a plurality of optimized areas are determined by utilizing the first preset optimized area and the second preset optimized area, so that the whole vehicle requirement is preferentially met, and casting manufacturability (technological parameters, mold structure and casting system design) are simultaneously met, wherein the technological parameters comprise injection speed, mold locking force, mold temperature, vacuum degree and material composition, and the area division is performed.

As shown in fig. 11, 12, 13 and 14, the post-die-casting floor structure may include: a first region 100 including at least one of the middle cross member 4, the rear cross member 5, and the two spaced side members 1, the present embodiment is described taking the first region 100 including the middle cross member 4, the rear cross member 5, and the two spaced side members 1 as an example; a second region 200 comprising two spaced apart wheel covers 2; and a third region 300 including a front cross member 3; wherein at least a portion of the material mechanical properties of the first region 100 are greater than those of the second region 200, and at least a portion of the material mechanical properties of the second region 200 are greater than those of the third region 300.

Through the technical scheme, namely, the die-cast floor structure disclosed by the invention, the die-cast floor structure is divided into the first area 100 comprising at least one of the middle cross beam 4, the rear cross beam 5 and the two longitudinal beams 1 arranged at intervals according to the mechanical properties of materials, the second area 200 comprising the wheel covers 2 arranged at intervals and the third area 300 comprising the front cross beam 3, at least part of the mechanical properties of the materials of the first area 100 are larger than those of the second area 200, at least part of the mechanical properties of the materials of the second area 200 are larger than those of the third area 300, the requirements of vehicle performance are met, the casting process characteristics of die castings are met, the modeling precision is improved, the simulation analysis accuracy is improved, the structural design and optimization are more extreme, the process debugging target is more accurate, and the front design and the subsequent structural optimization of the die-cast floor structure are facilitated.

As shown in fig. 10, 12 and 14, in some embodiments, the post-die-cast floor structure further includes a fourth region 400, the fourth region 400 includes the floor panel 6, and at least a portion of the fourth region 400 has a material mechanical property that is less than a material mechanical property of the third region 300. Wherein the fourth region 400 is configured to mainly satisfy NVH performance for reducing road noise. The thickness of the floor panel 6 is 2.0-3mm in consideration of manufacturability and performance. For example, the floor panels may be 2.0mm, 2.5mm, 2.8mm, 3.0mm.

It should be noted that, the first area 100, the second area 200, the third area 300 and the fourth area 400 are formed by performing performance modularization partition on the die-cast floor structure under the dual factors of fully considering the performance requirement of the whole vehicle and the characteristics of the die-casting process, for example, the first area 100 mainly meets the safety performance requirement of the whole vehicle, namely the vehicle rear collision performance requirement; the second region 200 mainly meets the durability and NVH (modal) requirements of the whole vehicle structure, and the flange portion 22b of the wheel cover 2 needs to further meet the SPR (riveting) requirements in consideration of the riveting relation with the vehicle body structure; the third region 300 is mainly connected to the battery pack while being required to withstand side impact.

As the characteristics of the die casting process can be known, the performances of the corresponding positions of the large die castings, which are close to the pouring gate and correspond to the main pouring runner and the secondary pouring runner, are different, the regional division can be optimized and adjusted according to the casting process characteristics of the large die castings on the basis of dividing the regions according to the structural characteristics, and the regional division accuracy is further improved.

The process characteristics of the large die casting can comprise a casting process reference, a mold structure, a pouring system design structure and the like, wherein the process reference mainly comprises injection speed, mold locking force, mold temperature, vacuum degree, material composition and the like; the die structure can meet the requirement of the production of the die-cast floor structure, is matched with the design of a pouring system, is usually designed in advance, and mainly influences the positions of pouring gates, primary pouring runners and secondary pouring runners, so that the performances of different positions of the die-cast floor structure are influenced, and comprehensive consideration is needed. Under the condition of acquiring casting process references, mold structures and casting system designs, corresponding CAE modeling is carried out, simulation of the casting process is carried out according to the casting process references, the mold structures and the casting system designs can be combined according to simulation results, thicknesses of different positions of the die-cast floor structure, distances from pouring gates, positions of materials in a main pouring runner or a secondary pouring runner and pouring simulation (namely, positions of the materials at the same moment) are obtained, the thicknesses are the same, the distances from the pouring gates are the same, the positions of the pouring materials at the same pouring runner and the same moment can be regarded as similar or approximate material properties, and the die-cast floor structure can be used as a reference for regional division.

It should be noted that, the performance changes of different areas caused by the characteristics of the die casting process, including the difference of the performance corresponding to different thicknesses and the difference of the performance at different flow points (i.e. the distance from the pouring gate) should be fully considered, and may be determined by referring to the content of patent publication No. CN114487337B, the patent name "test sample for verifying the die casting process and test method for die casting materials", or may be adaptively adjusted based thereon to obtain the product.

Optionally, the material mechanical properties include at least one of yield strength, tensile strength, elongation after break, and bend angle. The mechanical properties of the materials in the first region 100, the second region 200, the third region 300, and the fourth region 400 may include yield strength, tensile strength, elongation after break, and bending angle, and in addition, other performance references including these properties, such as fatigue strength, riveting performance, area reduction, etc., may be used in the design, simulation, and optimization process of the die-cast floor structure, and those skilled in the art may perform adaptive selection according to actual needs, which will not be described herein again.

As shown in fig. 11 and 14, in some embodiments, according to the connection relationship between the longitudinal beam 1 and other structural members in the die-cast floor structure, and other opponents of the vehicle body, the first area 100 may be further divided into an area one 110 and an area two 120, where the longitudinal beam 1 includes a longitudinal beam front section 12 and a longitudinal beam middle rear section 11; the first area 110 is an annular frame surrounded by the middle cross beam 4, the rear cross beam 5 and the middle and rear sections 11 of the two longitudinal beams which are arranged at intervals; the second region 120 includes two spaced apart stringer front sections 12. The first area 100 is mainly used for absorbing and transmitting the effect of the vehicle back collision test, so the material mechanical property of the first area 100 should be highest in the three areas, and since the first area 110 is closer to the direction of the vehicle back collision test than the second area 120, the material mechanical property of the first area 110 is generally greater than the material mechanical property of the second area 120.

Optionally, the first region 110 and the second region 120 are configured to meet a backside impact performance requirement. The ring frame is mainly used for bearing the impact of the rear collision of the whole vehicle when the vehicle is in a rear collision test, so the first area 110 is configured to meet the rear collision performance requirement. Meanwhile, the front side member 12 forming the second area 120 is mainly used for connecting with the sill beam, and also transmits the acting force during the back collision, so that the second area 120 can be configured to meet the back collision performance requirement. The requirements for the rear collision performance can be the performance requirements in the rear collision simulation and/or the rear collision test of the whole vehicle in the whole vehicle state, and can also be the rear collision test aiming at a single structural member of the die-casting rear floor structure.

In some embodiments, considering the positional relationship of the first region 110 and the second region 120 in the back collision test and the performance requirement actually required, the mechanical properties of the first region 110 are greater than those of the second region 120.

In some embodiments, the material mechanical properties of the first region 110 may satisfy: the yield strength is more than or equal to 130MPa, the tensile strength is more than or equal to 260MPa, the elongation after fracture is more than or equal to 10 percent, and the bending angle is more than or equal to 30 degrees; the mechanical properties of the material of the second region 120 may satisfy: the yield strength is more than or equal to 125MPa, the tensile strength is more than or equal to 250MPa, the elongation after fracture is more than or equal to 7%, and the bending angle is more than or equal to 25 degrees.

The first region 100 of the die-cast floor structure is refined again by constructing the first region 100 into the first region 110 and the second region 120 with different material mechanics, so that the manufacturability of the die-cast floor structure is more facilitated, the modularization performance is fully considered, and the process debugging target can be more accurate.

In some embodiments, as shown in fig. 7, 8 and 9, the middle and rear section 11 of the stringer includes a stringer body 111, the stringer body 111 includes an upper side rail 111a, a lower side rail 111b, a middle rail 111c connecting the upper side rail 111a and the lower side rail 111b, and a reinforcement structure 112; the reinforcing rib structure 112 is disposed between the upper side beam 111a and the lower side beam 111b, and connects the upper side beam 111a, the lower side beam 111b, and the intermediate beam 111c, respectively.

The stiffener structure 112 may be designed in any suitable configuration, and in some embodiments, the stiffener structure 112 includes a first stiffener 112a and a second stiffener 112b; the first reinforcing ribs 112a are vertically connected to the roof side rail 111a, the roof side rail 111b, and the center rail 111c, respectively; the second reinforcing rib 112b is vertically connected to the intermediate beam 111c, and is inclined with respect to the upper side beam 111a and/or the lower side beam 111 b. Wherein, the extending direction of the first reinforcing rib 112a is perpendicular to the upper side beam 111a and the lower side beam 111b respectively to improve the strength and rigidity between the upper side beam 111a and the lower side beam 111b, and in addition, a second reinforcing rib 112b which is obliquely arranged relative to the upper side beam 111a or the lower side beam 111b is added for the angle of rotation of the upper side beam 111a and the lower side beam 111b to further improve the strength and rigidity at the position so as to meet the performance requirement of the longitudinal beam 1.

Alternatively, the stringer body 111 has a thickness of 4-7mm; the thickness of the reinforcing rib structure 112 is 2.5-4mm; and/or the thickness of the middle cross beam 4 is 2.5-4.5mm; the thickness of the front cross beam 3 is 2.5-3mm; the thickness of the rear cross beam 5 is 2.5-3mm. Wherein, middle crossbeam 4 includes the crossbeam body and locates the strengthening rib of crossbeam body, and the strengthening rib mainly increases the rigidity of seat mounting point and safety belt mounting point position. The reinforcing ribs are arranged in a W shape or approximately W shape along the extending direction of the beam body, and the thickness of the beam body is 2.5-3.5mm; the thickness of the reinforcing rib is 3-4.5mm. The front beam 3 is the most difficult part to be filled by die casting, and the front beam 3 has the main function of being connected with a battery pack and keeping sealing with the battery pack. The rear cross beam 5 is close to the gate, the performance is high, the thickness of the structure can be reduced as much as possible under the condition of process permission in design, and the limit can be 2.5mm.

The thickness of the upper side rail 111a, the lower side rail 111b, and the middle rail 111c of the side rail body 111 may be selected in the range of 4-7mm, for example, may be 4mm, 5mm, 6mm, and 7mm; the thicknesses of the first and second reinforcing ribs 112a and 112b may be 2.5mm, 3mm, 3.5mm, and 4mm.

It should be noted that other reinforcing ribs may not be provided between the upper side beam 111a and the lower side beam 111b, and the other individual reinforcing ribs may be provided in a manner that they are appropriately increased or decreased based on CAE analysis after the subsequent application of the modular material cards, or may be increased according to performance requirements.

As shown in fig. 7, 8, 11 and 13, in some embodiments, the wheel cover 2 includes a wheel cover mid-front section 22 and a wheel cover rear section 21; the second region 200 includes a region three 210 formed by the rear section 21 of the wheel cover and a region four 220 formed by the front section 22 of the wheel cover. The front section 22 in the wheel cover 2 far away from the rear cross beam 5 and the rear section 21 in the wheel cover near to the rear cross beam 5 can respectively consider the mechanical properties of materials in the two areas, the modularized areas can be divided more accurately, the modeling accuracy is improved, and the CAE simulation analysis accuracy is improved.

Since the wheel cover 2 body is mainly disposed around the tire of the vehicle, it is necessary to consider the NVH (modal performance) requirement, and since the damper seat 21a is formed on the wheel cover 2 for mounting the damper, it is necessary to consider the durability of the whole vehicle, and in summary, the third region 210 and the fourth region 220 are required to be configured to satisfy the durability requirement and the NVH requirement of the whole vehicle.

Considering that the third region 210 is closer to the side of the vehicle rear impact test collision, at least a portion of the performance of the third region 210 may be greater than that of the fourth region 220, i.e., at least a portion of the material mechanical properties of the third region 210 are greater than that of the fourth region 220. For example, the material mechanical properties of region three 210 may satisfy: the yield strength is more than or equal to 125MPa, the tensile strength is more than or equal to 250Pa, the elongation after fracture is more than or equal to 7%, and the bending angle is more than or equal to 25 degrees; and the mechanical properties of the material of the fourth region 220 can satisfy the following conditions: the mechanical properties of the material of the first sub-region 220a satisfy the following conditions: the yield strength is more than or equal to 120MPa, the tensile strength is more than or equal to 250Pa, the elongation after fracture is more than or equal to 5%, and the bending angle is more than or equal to 20 degrees.

As shown in fig. 7 and 11, in other embodiments, the front section 22 of the wheel cover may include a body portion 22a and a flange portion 22b; the fourth region 220 includes a first sub-region 220a formed by the body portion 22a and a second sub-region 220b formed by the burring portion 22b, and the second sub-region 220b is configured to meet the caulking performance requirements. The first sub-region 220a corresponding to the body portion 22a needs to meet the requirements of durability and NVH of the whole vehicle, and the second sub-region 220b corresponding to the flange portion 22b needs to be riveted with the reinforcing plate of the vehicle body, so that the flange portion 22b needs to meet the requirements of durability and NVH of the whole vehicle and also needs to meet the requirements of SPR riveting. The method is used for improving the actual performance requirement of the floor structure after die casting, improving the accuracy of structural design and optimization, and better meeting the die casting process requirement and the connecting process requirement.

On the premise of meeting the material mechanical property requirement of the first sub-region 220a, at least part of the material mechanical property of the second sub-region 220b is larger than that of the first sub-region 220a, so as to meet the riveting requirement of the flanging part 22 b. For example, the material mechanical properties of the region three 210 satisfy: the yield strength is more than or equal to 125MPa, the tensile strength is more than or equal to 250Pa, the elongation after fracture is more than or equal to 7%, and the bending angle is more than or equal to 25 degrees; the mechanical properties of the material of the first sub-region 220a satisfy the following conditions: the yield strength is more than or equal to 120MPa, the tensile strength is more than or equal to 250Pa, the elongation after fracture is more than or equal to 5%, and the bending angle is more than or equal to 20 degrees; the mechanical properties of the material of the second sub-region 220b satisfy the following conditions: the yield strength is more than or equal to 125MPa, the tensile strength is more than or equal to 250Pa, the elongation after fracture is more than or equal to 7%, and the bending angle is more than or equal to 25 degrees.

Alternatively, the thickness of the body portion 22a of the front section 22 in the wheel cover is 2.5-5mm; the thickness of the flanging part 22b of the front section 22 in the wheel cover is 2.5-3mm; and/or the thickness of the rear section 21 of the wheel cover is 4-6mm. Wherein the thickness near the side member 1 may be set to 4-5mm, and the thickness near the burring 22b and burring 22b may be set to 2.5-3mm. In addition, considering that the wheel cover rear section 21 is provided with the damper seat 21a, the thickness at the damper seat 21a may be set to 4.5-6mm to ensure rigidity and strength thereat.

Optionally, the third region 300 is configured to meet side impact performance requirements. Wherein the third area 300 is formed by the front cross member 3 of the die-cast floor structure, the third area 300 is connected with the battery pack, and therefore, the third area 300 mainly needs to bear side impact requirements, and in some embodiments, the material mechanical properties of the third area 300 can meet the following requirements: the yield strength is more than or equal to 120MPa, the tensile strength is more than or equal to 240Pa, the elongation after fracture is more than or equal to 5%, and the bending angle is more than or equal to 20 degrees.

In a second aspect of the present disclosure, a vehicle is further provided, where the vehicle includes the above-mentioned post-die-cast floor structure, and therefore, the vehicle also has the advantages of the post-die-cast floor structure, which are not described herein.

According to the die-cast floor structure and the vehicle, as the die-cast floor structure is a large die-cast structure, the performances of different areas of actual parts are not consistent due to the characteristics of a die-casting process, and the integrated die-cast floor structure is subjected to performance modularization partition under the double factors of fully considering the whole vehicle performance requirement and the die-casting process characteristics, so that the requirement of the whole vehicle performance can be ensured, and the die-casting process requirement and the connecting process requirement can be met.

In addition, the die-cast floor structure partitioned according to the mechanical properties of the materials is more accurate in CAE modeling; the simulation result is more accurate in CAE simulation analysis; meanwhile, the structural design of the integrated die-cast floor structure is more extreme; the performance of the integrated die-cast floor structure can more accurately meet the performance requirement of the whole vehicle; and the manufacturability of the integrated die-cast floor structure fully considers the modularization performance, so that the process debugging target can be more accurate.

According to the performance division of the optimized area of the large die casting, material cards (material mechanical property information) are established according to the corresponding performances of each thickness and flow length obtained from a test piece for verifying the die casting manufacturability and a test method of die casting materials, and are input into a CAE model for analysis. Through the plurality of optimized areas and the corresponding mechanical properties of the materials, the accuracy of CAE analysis is higher, and structural design is more extreme.

As shown in fig. 15, a block diagram of a structure optimizing apparatus for a large die casting according to an embodiment of the present disclosure, the structure optimizing apparatus 700 for a large die casting includes a dividing module 710, an acquiring module 720, and an optimizing module 730.

The dividing module 710 is used to divide the large die casting into a plurality of optimized regions.

The obtaining module 720 is configured to obtain the mechanical property information of the material in each optimized region.

The optimizing module 730 is configured to optimize the structure of the large die casting according to the material mechanical property information of the plurality of optimizing regions and the optimizing regions.

The specific manner in which the various modules perform the operations in the apparatus of the above embodiments have been described in detail in connection with the embodiments of the method, and will not be described in detail herein.

The preferred embodiments of the present disclosure have been described in detail above with reference to the accompanying drawings, but the present disclosure is not limited to the specific details of the above embodiments, and various simple modifications may be made to the technical solutions of the present disclosure within the scope of the technical concept of the present disclosure, and all the simple modifications belong to the protection scope of the present disclosure.

In addition, the specific features described in the foregoing embodiments may be combined in any suitable manner, and in order to avoid unnecessary repetition, the present disclosure does not further describe various possible combinations.

Moreover, any combination between the various embodiments of the present disclosure is possible as long as it does not depart from the spirit of the present disclosure, which should also be construed as the disclosure of the present disclosure.

Claims (8)

1. A method for optimizing the structure of a large die casting, the method comprising:

dividing the large die casting into a plurality of optimized areas;

acquiring material mechanical property information in each optimized region;

optimizing the structure of the large die casting according to the material mechanical property information of the plurality of optimizing areas and the optimizing areas;

the dividing the large die casting into a plurality of optimized areas includes:

obtaining structural characteristics of a large die casting, and determining a first preset optimization area according to the structural characteristics of the large die casting;

acquiring process characteristics of the large die casting, and determining a second preset optimization area according to the process characteristics of the large die casting;

determining a plurality of optimization areas according to the first preset optimization area and the second preset optimization area;

the determining a first preset optimizing area according to the structural characteristics of the large die casting comprises the following steps:

acquiring a connection state of the structural feature in a whole vehicle state and a performance requirement corresponding to the structural feature;

Performing performance analysis on the large die casting in a whole vehicle state according to the connection state and the performance requirement;

determining a first preset optimization area according to the connection state and the performance analysis result;

the obtaining the process characteristics of the large die casting, and determining a second preset optimization area according to the process characteristics of the large die casting comprises the following steps:

acquiring casting process parameters, a mould structure and a pouring system design of a large die casting;

casting simulation is carried out according to casting process parameters, a mold structure and casting system design;

and determining a second preset optimization area according to casting process parameters, the mold structure and casting system design and casting simulation results.

2. The method of claim 1, wherein said performing a performance analysis of the large die cast part in the complete vehicle state based on the connection state and the performance requirement comprises:

carrying out simulation analysis on the large die casting in the whole vehicle state; and/or

And carrying out whole-vehicle actual experimental analysis on the large die casting in a whole-vehicle state.

3. The method according to claim 1 or 2, wherein the performance analysis comprises: at least one of collision analysis, durability analysis, modal analysis, connection analysis, and sealing analysis.

4. The method of claim 1, wherein determining the second predetermined optimized region based on casting process parameters, mold structure, and casting system design and casting simulation results comprises:

obtaining thickness sizes of different positions of the large die casting;

obtaining the distances between different positions of the large die casting and the pouring gate;

determining the flow position of the casting material at the same moment by using casting simulation;

determining a mechanical property distribution diagram of the large die casting according to thickness sizes of different positions of the large die casting, distances between different positions and a pouring gate and flowing positions of pouring materials at the same moment;

and determining a second preset optimization area according to the mechanical property distribution diagram.

5. The method of claim 1, wherein the casting process parameters include: injection speed, mold locking force, mold temperature, vacuum degree and material composition.

6. The method of claim 1, wherein optimizing the structure of the large die cast part based on the plurality of optimization regions and the material mechanical property information of the optimization regions comprises:

establishing a CAE model of the large die casting according to the material mechanical property information of the plurality of optimized areas and the optimized areas;

And optimizing the structure of the large die casting by using the CAE model of the large die casting.

7. The method of claim 6, wherein optimizing the structure of the large die cast part using the CAE model of the large die cast part comprises:

optimizing the thickness in the optimized region of the large die casting;

the number and arrangement of the reinforcing ribs in the optimization area of the large die casting are optimized.

8. A structure optimizing apparatus for large die castings, the apparatus comprising:

the dividing module is used for dividing the large die casting into a plurality of optimized areas;

the acquisition module is used for acquiring the material mechanical property information in each optimized area;

the optimizing module is used for optimizing the structure of the large die casting according to the material mechanical property information of the optimizing areas;

the dividing the large die casting into a plurality of optimized areas includes:

obtaining structural characteristics of a large die casting, and determining a first preset optimization area according to the structural characteristics of the large die casting;

acquiring process characteristics of the large die casting, and determining a second preset optimization area according to the process characteristics of the large die casting;

determining a plurality of optimization areas according to the first preset optimization area and the second preset optimization area;

The determining a first preset optimizing area according to the structural characteristics of the large die casting comprises the following steps:

acquiring a connection state of the structural feature in a whole vehicle state and a performance requirement corresponding to the structural feature;

performing performance analysis on the large die casting in a whole vehicle state according to the connection state and the performance requirement;

determining a first preset optimization area according to the connection state and the performance analysis result;

the obtaining the process characteristics of the large die casting, and determining a second preset optimization area according to the process characteristics of the large die casting comprises the following steps:

acquiring casting process parameters, a mould structure and a pouring system design of a large die casting;

casting simulation is carried out according to casting process parameters, a mold structure and casting system design;

and determining a second preset optimization area according to casting process parameters, the mold structure and casting system design and casting simulation results.