Power assembly rubber suspension, manufacturing method thereof and vehicle

Abstract

The invention discloses a power assembly rubber suspension, a manufacturing method thereof and a vehicle, and belongs to the technical field of vehicles. The power assembly rubber suspension comprises a main spring, an inner sleeve and an outer sleeve, an inner ring of the main spring and the metal inner sleeve are assembled together through the vulcanization effect, an outer ring of the main spring and the outer sleeve are assembled together through the vulcanization effect, the width of a rubber block connected with the inner ring and the outer ring of the main spring is W, the length of the rubber block is L, and the included angle theta between two adjacent rubber blocks is equal to 0. The distance D between the rubber block and the upper surface of the inner ring of the main spring and the diameter shrinkage r of the outer ring of the main spring when the outer sleeve is vulcanized: W is more than or equal to 13.22 mm and less than or equal to 17.33 mm; l is greater than or equal to 37.81 mm and less than or equal to 49.38 mm; 0 < = D < = 4mm; 0.1 mm < = r < = 0.2 mm; and theta is greater than or equal to 67.8 degrees and less than or equal to 90.27 degrees.

Description

Technical Field

[0001] The present invention belongs to the technical field of vehicles, and more specifically, relates to a powertrain rubber suspension, a manufacturing method thereof, and a vehicle. Background Art

[0002] With the rapid development of the automobile manufacturing industry, consumers' requirements for driving experience are increasing day by day. They are no longer satisfied with the basic driving functions of the vehicle, but pursue a more refined and comfortable driving environment. In such a market context, noise, vibration and harshness (NVH) performance has become one of the important standards for measuring automobile quality. These three factors together constitute the overall sound and vibration feeling of the car during driving. Noise mainly comes from the engine, tire contact with the road, wind noise, etc. It not only affects the passengers' auditory experience, but also may interfere with the driver's attention, thereby affecting driving safety. Vibration mainly comes from the engine, transmission system and the interaction between the vehicle and the road. Long-term vibration will not only make passengers feel uncomfortable, but also may damage vehicle parts and shorten the service life of the vehicle. Harshness refers to the comprehensive feeling of sound and vibration, which reflects the overall sound and vibration quality of the vehicle. Faced with consumers' increasing pursuit of driving comfort, automobile companies have begun to invest more energy in improving NVH performance. They continuously reduce the noise and vibration levels of vehicles and improve the riding experience of passengers by adopting advanced sound insulation materials, optimizing vehicle structures, improving engines and transmission systems, etc. At the same time, the company has also strengthened the research and development and testing of NVH performance to ensure that each model can achieve the best sound and vibration performance. It is worth mentioning that the improvement of NVH performance is not only related to the comfort experience of passengers, but also closely related to the durability of automotive parts. Long-term vibration and noise will not only make passengers feel uncomfortable, but may also cause damage to the internal parts of the vehicle, resulting in reduced vehicle performance or even failure. Therefore, by improving NVH performance, not only can the driving experience of passengers be improved, but also the overall reliability and durability of the vehicle can be improved.

[0003] As an important part of the powertrain suspension system, the rubber suspension consists of key parts such as the rubber main spring, the metal inner core and the metal outer jacket. This structure is not only simple and clear, but also has a simple manufacturing process, which greatly improves production efficiency. The rubber suspension has a very high cost performance. First of all, compared with the hydraulic suspension and other complex suspension systems, the material cost of the rubber suspension is lower, and due to its simple structure, the processing and assembly process is more efficient. This makes the rubber suspension have a clear advantage in price and can meet the cost control needs of automobile manufacturers. At the same time, the performance of the rubber suspension is stable and reliable, which can meet the use requirements of the car under various working conditions. Secondly, the rubber suspension has a strong adaptability. The rubber material has good elasticity and damping properties, which can effectively isolate and reduce the vibration and noise generated by the powertrain. Whether it is urban roads or off-road driving, the rubber suspension can maintain good performance and ensure the stability and comfort of the vehicle. In addition, the rubber suspension also has strong durability and anti-aging ability, and can maintain stable performance during long-term use.

[0004] However, fatigue damage of rubber materials is often difficult to detect. Once failure occurs, the consequences are extremely serious, causing hidden dangers to driving safety and even threatening the life safety of passengers. The fatigue life of rubber suspension is related to its installation position and material factors. In practice, these two factors are limited. Therefore, it is necessary to adjust and optimize its structural parameters to ensure that the suspension reaches the target stiffness value while improving fatigue life. The reasonable design of the suspension main spring parameters determines the vibration isolation effect of the suspension. To ensure that the rubber suspension has a stable vibration isolation effect for a long time, it is necessary that it does not fail when subjected to loads under different working conditions. The optimization method of adjusting the rubber suspension parameters is conducive to improving the fatigue life of the suspension. For example, Chinese patent CN221137603U discloses a rubber suspension assembly and a vehicle, including: a suspension frame, a main spring and a bracket arm. An upper mounting hole is set in the middle of the suspension frame; the main spring is symmetrically arranged on both sides of the suspension frame with the upper mounting hole as the center; the bracket arm is installed in the upper mounting hole. The use of this symmetrically split main spring suspension assembly avoids the problem of fatigue damage and failure of the main spring due to concentrated transmission of exciting force, thereby increasing the service life of the suspension assembly.

[0005] In addition, in the early stages of product development and design, in order to ensure that the stiffness of the rubber suspension meets the design requirements, the company uses CAE simulation to optimize its performance by adjusting the structural parameters of the suspension. This method can foresee the performance of the product in the early stages of product development, shorten the development cycle, and improve development efficiency. At the same time, through structural optimization, potential risks can also be discovered and improved, thereby ensuring the NVH performance and driving safety of the entire vehicle. Summary of the invention

[0006] 1. Problem to be solved

[0007] In view of the technical problems existing in the prior art, the present invention provides a powertrain rubber suspension and a manufacturing method and a vehicle, optimizes the structural parameters of the rubber suspension, and improves the fatigue life of the rubber suspension.

[0008] 2. Technical solution

[0009] In order to solve the above problems, the technical solution adopted by the present invention is as follows:

[0010] A first aspect of the present invention provides a powertrain rubber suspension, which includes a main spring, an inner sleeve and an outer sleeve, the inner ring of the main spring is assembled with the metal inner sleeve by vulcanization, the outer ring of the main spring is assembled with the outer sleeve by vulcanization, the width W of the rubber block connecting the inner ring and the outer ring of the main spring, the length L of the rubber block, the angle θ between two adjacent rubber blocks, the distance D between the rubber block and the upper surface of the inner ring of the main spring, and the reduction r of the outer ring of the main spring when the outer sleeve is vulcanized are: 13.22mm≤W≤17.33mm; 37.81mm≤L≤49.38mm; 0≤D≤4mm; 0.1mm≤r≤0.2mm; 67.8°≤θ≤90.27°.

[0011] According to any embodiment of the first aspect of the present invention, the rubber suspension parameter combination is as follows: the rubber block width W is 17 mm, the length L is 44 mm, the angle θ between two adjacent rubber blocks is 68°, the distance D is 4 mm, and the diameter reduction r is 0.2 mm.

[0012] The second aspect of the present invention provides a method for manufacturing a powertrain rubber suspension, comprising the steps of: analyzing the dimensions of the input inner and outer rings of the suspension main spring, that is, the main parameters of the main spring structure are subject to the dimensions and shapes of the inner and outer rings, so when designing the internal rubber body of the main spring, based on experience and size restrictions, the width W and length L of the rubber block connecting the inner and outer rings of the main spring, the angle θ between two adjacent rubber blocks, and the distance D from the upper surface of the inner ring are selected as structural design parameters, and the size of the outer ring diameter reduction r of the rubber main spring when the outer shell is vulcanized is selected;

[0013] Decoupling optimization and dynamic and static stiffness design are performed on the input design parameters to obtain a rubber mount stiffness value that meets the decoupling target of more than 80%. The stiffness values ​​of each item in the local coordinate system UVW are 300N / mm, 480N / mm, and 120N / mm respectively. Because the mount installation position is in the V direction under the local coordinate system of the mount, meeting the stiffness requirements in this direction is the primary optimization goal.

[0014] The binomial function of the rubber block width W, length L, and the angle θ between two adjacent rubber blocks, which have a greater impact on the suspension stiffness, and the stiffness value Kv is obtained. The stiffness value is predicted by the curve, and the parameter range is appropriately narrowed, which is conducive to the next step of orthogonal testing.

[0015] An orthogonal test with 5 factors and 3 levels was designed, and the stiffness and fatigue life of the suspension under 27 different combinations were calculated. The optimal level combination that met the stiffness target value requirement and the optimal level combination that met the maximum fatigue life value were obtained.

[0016] According to any embodiment of the second aspect of the present invention, when the angle θ is between 67.8° and 90.27°, with 5° as the interval unit, the other three parameters and the structural shape remain unchanged, and the rubber block is rotated by a certain angle (symmetrically) in Catia software and numbered sequentially as θi (i=1-8).

[0017] According to any embodiment of the second aspect of the present invention, when the distance D is between 0-4mm and the interval unit is 1mm, the other three parameters and the structural shape remain unchanged, the main spring of the rubber suspension is modeled in the Catia software, and in the second limitation of more functions of the "boss", the distance from the upper surface of the inner ring is set to different values, and the main springs with different values ​​from the upper and lower surfaces of the inner ring are obtained, which are numbered Di (i=1-5) in sequence.

[0018] According to any implementation scheme of the second aspect of the purpose of the present invention, a C3D8RH type unit is used to divide the grid in ABAQUS software, and the grid is divided into 19582 units. The material properties are set to the Ogden model, and a "step-1 / 2" analysis step is created. The step-1 analysis step is used to set the size of the reduction. When calculating, the suspension is first reduced in diameter. Considering the requirements of the reduction process, the reduction amount r of the rubber suspension is generally less than 10% of the thickness of the outer ring of the main spring, and the buffer thickness of the rubber jacket is 2mm. Therefore, the reduction amount is 0.1mm, 0.125mm, 0.15mm, and 0.2mm; step-2 is used to set the loading displacement load, and the boundary condition setting is the same as the previous section. When the reduction process is performed, a displacement of 6mm is set in the V direction in the local coordinate system of the suspension to complete the setting.

[0019] According to any embodiment of the second aspect of the present invention, in order to control the deviation of the stiffness value near the target stiffness value and thus narrow the parameter value range, the least squares method is used to fit the data in Matlab for the parameter value with a greater influence, and a quadratic polynomial function is fitted:

[0020] The fitting results are as follows:

[0021]

[0022] According to any embodiment of the second aspect of the present invention, according to the stiffness requirement within the range of 480±15%, the stiffness value can range from 408≤Kv≤552, then the rubber block value range obtained by calculating the suspension parameters by quadratic polynomials (1-4), (1-5), and (1-6) is as shown in formulas (1-7), (1-8), and (1-9), all in mm:

[0023] 13.22≤W≤17.33 (1-7)

[0024] 37.81≤L≤49.33 (1-8)

[0025] 67.8°≤θ≤90.27°(1-9).

[0026] According to any implementation scheme of the second aspect of the present invention, the obtained parameter range is rounded, and the length L of the rubber block is limited by the suspension structure and takes the maximum value, that is, the right end point in formula (1-8) is 44 mm; the width, length, and angle of the suspension rubber block after value adjustment are as shown in formulas (1-10), (1-11), and (1-12):

[0027] 13≤W≤17 (1-10)

[0028] 38≤L≤44 (1-11)

[0029] 68°≤θ≤90° (1-12)

[0030] The range of values ​​of the distance D between the rubber block and the upper surface of the inner ring and the diameter reduction of the suspended outer ring are as shown in formulas (1-13) and (1-14);

[0031] 0≤D≤4 (1-13)

[0032] 0.1≤r≤0.2 (1-14).

[0033] A third aspect of the present invention provides a vehicle having the powertrain rubber mount of the first aspect.

[0034] 3. Beneficial effects

[0035] Compared with the prior art, the present invention has the following beneficial effects:

[0036] (1) The vibration isolation effect of the powertrain rubber mount of the present invention is determined by the reasonable design of the main spring parameters of the mount. The mount should be neither too soft nor too hard. Therefore, how to optimize the selection of the mount stiffness is an extremely important issue in the early stage of the mount design. To ensure that the rubber mount has a stable vibration isolation effect for a long time, it is required that it does not fail when subjected to loads under different working conditions. By optimizing the structural parameters of the rubber mount, the fatigue life of the rubber mount is increased by at least 10%.

[0037] (2) The powertrain rubber suspension of the present invention can not only reduce the vibration transmitted from the engine to the frame, reduce the vibration and noise of the whole vehicle, and improve the ride comfort, but also reduce the vibration damage to the powertrain caused by road excitation, which is beneficial to improving the NVH of the whole vehicle. Reasonable static characteristics of the suspension are necessary to avoid interference between the powertrain and the vehicle body and surrounding components and to control the displacement of the powertrain. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] The technical solution of the present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments, but it should be understood that these drawings are designed only for explanation purposes and are not intended to limit the scope of the present invention. In addition, unless otherwise specified, these drawings are intended only to conceptually illustrate the structural configurations described herein and are not necessarily drawn to scale.

[0039] Figure 1 A three-dimensional modeling diagram of initial parameters of the rubber main spring of the present invention;

[0040] Figure 2 It is a plane projection diagram of the inner and outer diameters UV of the suspension main spring of the present invention;

[0041] Figure 3 is a schematic diagram of a powertrain rubber mount of the present invention;

[0042] Figure 4 Simplify the meshing of the rubber main spring model of the present invention;

[0043] Figure 5 The boundary condition setting of the rubber main spring of the present invention;

[0044] Figure 6 The coupling point of the rubber main spring RP-1 of the present invention is created;

[0045] Figure 7 This is a diagram of different widths of the rubber block of the present invention;

[0046] Figure 8 This is a diagram of different lengths of the rubber block of the present invention;

[0047] Fig. 9 This is a diagram of different angles of adjacent rubber blocks in the V direction of the present invention;

[0048] Fig.10 A distance diagram of the rubber main spring from the upper surface of the inner ring of the present invention;

[0049] Fig.11 It is the finite element mesh loading model after loading the diameter reduction amount of the present invention;

[0050] Fig.12 is a fitting relationship curve between various parameters and stiffness of the rubber block of the present invention;

[0051] Fig.13 is the sensitivity of the input variable of the present invention to the output response Kv;

[0052] Fig.14 It is the sensitivity of the input variable to the output response Nf of the present invention. DETAILED DESCRIPTION

[0053] The following detailed description of exemplary embodiments of the present invention refers to the accompanying drawings, which form a part of the description, and in which exemplary embodiments of the present invention that can be implemented are shown as examples. Although these exemplary embodiments are described in sufficient detail to enable those skilled in the art to implement the present invention, it should be understood that other embodiments can be implemented and various changes can be made to the present invention without departing from the spirit and scope of the present invention. The following more detailed description of the embodiments of the present invention is not intended to limit the scope of the claimed invention, but is only for the purpose of illustrating and not limiting the description of the characteristics and features of the present invention, so as to propose the best mode for performing the present invention and to enable those skilled in the art to implement the present invention. Therefore, the scope of the present invention is limited only by the appended claims.

[0054] The following detailed description of the present invention and example embodiments may be better understood in conjunction with the accompanying drawings, in which elements and features of the present invention are identified by reference numerals.

[0055] The powertrain rubber suspension of the present invention includes a main spring, an inner sleeve and an outer sleeve. The inner ring of the main spring is assembled with the metal inner sleeve by vulcanization, and the outer ring of the main spring is assembled with the outer sleeve by vulcanization. Before the design of the rubber suspension main spring, its inner ring and outer ring are assembled with the metal inner sleeve and outer sleeve respectively by vulcanization. Since the size and shape of the inner and outer sleeves are determined, the size and shape of the inner and outer diameters of the suspension main spring are determined. In Catia software, a three-dimensional schematic diagram of the inner ring and outer ring of the rubber suspension main spring before design is designed according to the size requirements as shown in the figure. Figure 1 (a) Figure 1 (b) as shown.

[0056] like Figure 2 (a) is the UV plane projection diagram of the suspension main spring. Figure 2 (b) is a UW plane cross-sectional view. The local coordinate system of the rubber suspension is UVW, and the V direction is in the vertical direction of the vehicle, that is, the gravity direction. This embodiment uses this type of rubber suspension, which is mainly subjected to the load in the V direction after installation. The rubber body connecting the inner and outer rings of the main spring of the suspension is called a rubber block. Figure 2As shown in (a), in the figure, there are five rubber suspension structural parameters: the width (Width, W), length (Length, L), angle (θ) of the rubber block connecting the inner and outer rings of the rubber main spring, the distance (Distance, D) from the upper surface of the inner ring, and the diameter reduction (r) of the outer ring of the rubber main spring when the outer shell is vulcanized.

[0057] This embodiment takes GMW14116 as an example, which is a technical standard document of General Motors on the powertrain suspension subsystem. It puts forward detailed requirements for the design, manufacture, and testing of the powertrain suspension system to ensure that the suspension system can meet the technical standards of General Motors and the performance requirements of the vehicle. The document involves a reasonable suspension torque-angle relationship curve, which can ensure that the suspension system has good vibration isolation performance and can suppress excessive displacement of the powertrain under conditions with large motion amplitude. The schematic diagram of the powertrain suspension system design of the present invention is shown in FIG. Figure 3 shown.

[0058] In the vehicle coordinate system, the X direction points to the rear of the car and the Z direction points upward. The powertrain mass and moment of inertia required for the suspension design are shown in Table 1-1, and the coordinates of the suspension elastic center and the powertrain center of mass are shown in Table 1-2. Under these conditions, the vehicle coordinate system is referenced.

[0059] Table 1-1 Powertrain mass and moment of inertia

[0060]

[0061] Table 1-2 Coordinates of suspension elastic center and powertrain mass center

[0062]

[0063] The target frequency of powertrain stiffness is shown in Table 1-3.

[0064] Table 1-3 Powertrain rigid body target frequency

[0065]

[0066] The stiffness of the three main axis directions of the left suspension, right suspension and rear suspension are taken as the optimization objects, with a total of 9 variables to be optimized. The maximum decoupling rate on the 6 degrees of freedom is taken as the goal. The MATLAB decoupling rate optimization program is used in conjunction with Isight for joint simulation calculation. The obtained suspension decoupling rate is shown in Table 1-4 below, where the dynamic stiffness is 1.4 times the static stiffness.

[0067] Table 1-4 Natural frequency and decoupling rate of the optimized system

[0068]

[0069]

[0070] It can be seen from the above table that the decoupling rates all meet the requirement of being greater than 80% of the target value.

[0071] Table 1-5 Optimized suspension spindle stiffness

[0072]

[0073] It should be noted that the model mesh division and boundary condition setting are performed in ABAQUS as follows:

[0074] (1) Construction of grid system

[0075] The model is divided into hexahedral meshes in ABAQUS. The advantages of using hexahedral meshes are:

[0076] (a) Better numerical stability: Hexahedral elements have better numerical stability and exhibit better convergence characteristics for certain problems (such as solid mechanics problems), and can usually converge to an accurate solution faster.

[0077] (b) Reducing the number of meshes: Compared with tetrahedral elements, using hexahedral elements can achieve higher mesh quality under the same geometric model, thereby reducing the number of required meshes. This helps to reduce computational costs and improve computational efficiency.

[0078] (c) Better strain / displacement interpolation: Hexahedral elements usually have better strain and displacement interpolation properties and can more accurately capture the strain and deformation distribution of the structure.

[0079] (d) More suitable for certain material behaviors: For some materials, such as isotropic materials such as rubber, hexahedral elements are more suitable for describing their mechanical behavior.

[0080] (e) Support for partial volume meshing: Hexahedral elements are generally easier to implement partial volume meshing, which means that complex geometries can be more conveniently refined locally to better capture local details. However, it should be noted that in some cases, tetrahedral elements may be more suitable, especially for problems with complex geometries or that require free meshing. In practical applications, it is usually necessary to select the appropriate element type based on the characteristics and requirements of the specific problem, and sometimes it is necessary to mix different types of elements to achieve the best analysis results. For example, in the early stages of design, the geometry needs to be resized to meet certain requirements. Using the tetrahedral mesh "Adaptive Mesh" function allows the system to automatically encrypt or delete meshes in areas with high stress gradients, thereby improving pre-processing efficiency.

[0081] like Figure 4 For the rubber suspension model, a second-order hexahedral 8-node linear hybrid reduction unit with a size of 2 mm was used for meshing (C3D8RH) in ABAQUS, where the number of grids was 14274 and the number of nodes was 22030. In the "property" module, the material was set to the hyperelastic Mooney-Rivlin constitutive model, the material constants are shown in the table below, and "Solid-Homogeneous" was selected for creating the section.

[0082]

[0083]

[0084] (2) Setting of boundary conditions

[0085] Before creating loads and constraints, create "step1" and "step2" analysis steps in the "step" module. The "step1" analysis step is used to constrain the six degrees of freedom of the outer contour of the rubber suspension to facilitate the subsequent shrinkage simulation. The "step2" analysis step is used to apply load constraints, and the output quantities such as "S, U, RT, NE, SENER" are set in the "Field output manager".

[0086] In order to simulate the vulcanization effect between the outer ring of the rubber main spring and the inner ring of the metal jacket, the six degrees of freedom of the rubber main spring are constrained respectively. The purpose is to make the outer ring of the rubber main spring not deform or the deformation effect is very small and negligible when simulating the actual working conditions during finite element analysis. Figure 5 To apply loads and create a constraint diagram for the rubber outer ring.

[0087] (3) Construction of connection relationship

[0088] According to the actual stress conditions of the rubber suspension, the load is often applied to the metal inner ring and the constraints are applied to the metal outer ring. In order to simulate the actual stress state of the metal inner ring, a coupling point is created at the geometric center of the inner ring of the rubber main spring. There are two types of coupling constraints for this point: one is the "Tie" constraint, which is usually used to simulate the vulcanization effect of the rubber main spring and the inner and outer sleeves to rigidly bind the two surfaces; the other is the "Couping" constraint, which controls the motion state of the unit node on a surface through a geometric reference point; in addition, the "Couping" constraint is divided into distributed coupling and motion coupling. Distributed coupling is to evenly transfer the force to each node, allowing the controlled surface to deform, while motion coupling is to establish a constraint relationship between the control point and the node.

[0089] When the rubber suspension metal ring in the present invention is subjected to force, the force is not evenly distributed on the surface. The forces on each surface are different, and the deformation of the metal ring itself is very small and can be ignored. Therefore, the kinematic coupling method should be used in this analysis to couple and constrain the point at the centroid of the metal inner ring with the point on the outer surface of the metal ring, such as Figure 6 As shown, the "RP-1" point is the coupling point. When adding a load constraint, it will act on this point, thereby applying the load to the outer surface of the metal inner ring.

[0090] In addition, rubber materials have the characteristic of large deformation. In finite element simulation, in order to prevent the rubber main springs from penetrating each other, it is necessary to impose constraints on the points or surfaces that may contact the rubber main springs. The face-to-face contact allows the slave surface to pass through the master surface but does not allow the master surface to pass through the slave surface. Based on the characteristics of the rubber main spring and the actual working conditions, face-to-face contact constraints are imposed on it. The contact surfaces do not contact in the tangential direction. The default is radial direct contact, and the friction coefficient between the contact surfaces is set to 0.3.

[0091]

Main rubber spring rubber block width W

[0092] In order to obtain the relationship between the width W of the rubber block and the V-direction stiffness in the local coordinate system of the rubber suspension, the width of the rubber block is taken as the research target. The width is between 10-22 mm, with 2 mm as the interval unit. The other three parameters and structural shape remain unchanged. The main spring of the rubber suspension is modeled in Catia software, and the width of the main spring rubber is translated in the direction of the original rubber block. The purpose of the translation is to keep the angle between the two main springs unchanged. The original V-direction angle between the two springs remains unchanged, and the main spring rubber blocks of different widths are obtained. They are numbered in sequence as Wi (i=1-7), and their local coordinate system UV plane diagram is shown as follows Figure 7 As shown in (a) and (b) in .

[0093] The seven models were meshed and finite element simulated in turn. The constraints during the simulation were consistent with the size and shape of the inner and outer diameters of the main springs of the suspension mentioned above. A displacement of 6 mm was applied in the V direction of the local coordinate system of the suspension for simulation calculation. The results are shown in Table 1-6.

[0094] Table 1-6 Effect of rubber block width on stiffness and effective tensile strain

[0095]

[0096] From the data in the above table, it can be concluded that as the width of the main spring rubber block increases, the stiffness value also increases, and the two tend to be positively correlated. The difference between the maximum and minimum values ​​is 423.7N / mm; the effective tensile strain increases when the main spring width is 10-20mm, and decreases when it is 20-22mm, and at the same time has an inverse relationship with the fatigue life.

[0097]

Rubber main spring rubber block length L

[0098] In order to obtain the relationship between the length L of the rubber main spring rubber block and the V-direction stiffness and fatigue life, the length is between 34-44mm, with 2mm as the interval unit, and the other three parameters and structural shape remain unchanged. In the Catia software, the stretching function in the "boss" of the main spring rubber block is used to stretch it to the set length value, and it is numbered Li (i=1-6) in sequence. The model diagram is as follows Figure 8 As shown in (a) and (b).

[0099] Table 1-7 Effect of rubber block length on stiffness and fatigue life

[0100]

[0101] It can be concluded from the data in the above table that as the length of the main spring rubber block increases, the stiffness value also increases, and the two tend to be positively correlated. The difference between the maximum and minimum stiffness values ​​is 123.18N / mm, which is a large difference; the effective tensile strain increases when the length of the main spring rubber block is 34-40mm, and the maximum is 0.3370. When it is 40-44mm, the effective tensile strain decreases.

[0102]

Angle θ between two adjacent rubber blocks

[0103] In order to obtain the relationship between the angle θ between adjacent rubber blocks of the rubber main spring and the V-direction stiffness and fatigue life, the rubber blocks are rotated by a certain angle (symmetrically) in Catia software when the angle is between 67.8° and 90.27°, with an interval of 5 degrees as the unit, and the other three parameters and structural shape remain unchanged. The rubber blocks are numbered sequentially as θi (i=1-8), and the model diagram is as follows: Fig. 9 As shown in (a) and (b).

[0104] Table 1-8 Effect of the angle between adjacent rubber blocks in the V direction on stiffness and fatigue life

[0105]

[0106] It can be concluded from the data in the above table that as the angle between adjacent rubber blocks increases, the stiffness value also decreases. The difference between the maximum and minimum stiffness values ​​is 230.21 N / mm, which is a large difference. The effective tensile strain gradually decreases when the angle between adjacent rubber blocks increases.

[0107] [Distance between the rubber block of the rubber main spring and the upper surface of the inner ring]

[0108] In order to obtain the relationship between the distance D between the rubber main spring and the upper surface of the inner ring and the V-direction stiffness and fatigue life, the main spring of the rubber suspension is modeled in Catia software when the distance is between 0-4mm and the interval unit is 1mm. The other three parameters and structural shape remain unchanged. In the second restriction of the more functions of the "boss", the distance from the upper surface of the inner ring is set to different values. The main springs with different values ​​from the upper and lower surfaces of the inner ring are obtained and numbered Di (i=1-5) in sequence. The figure is a simplified diagram of the local model. The parameters studied are marked in the figure. The model is local Fig.10 (a)(b).

[0109] Table 1-9 Effect of the distance between the rubber main spring and the upper surface of the inner ring on stiffness and fatigue life

[0110]

[0111] It can be concluded from the data in the above table that as the distance between the rubber main spring and the upper surface of the inner ring increases, the stiffness value increases at 0-2mm and decreases at 2-4mm. The difference between the maximum and minimum stiffness is 1.39N / mm, which is a small difference. When the distance is 0-2mm, the effective tensile strain decreases, when it is 2-3mm, the tensile strain increases, and when it is 1-4mm, the effective tensile strain decreases.

[0112] [The influence of the reduced diameter of the main spring outer ring on stiffness and durability]

[0113] It should be noted that the size of the rubber suspension reduction is usually selected according to design requirements and specific application scenarios, mainly depending on the following factors:

[0114] (1) Product design requirements: Determine the size of the rubber suspension reduction based on the product's functional and structural design requirements to ensure that it can achieve the expected functions and performance;

[0115] (2) Material properties: Consider the hardness, elastic modulus and other properties of the rubber material to determine the appropriate suspension reduction size so that it can function during use without affecting the overall performance of the product;

[0116] (3) Use environment: Determine the appropriate rubber suspension reduction size based on the environmental conditions in which the product will be used, such as temperature, pressure, vibration and other factors, to ensure the stability and durability of the product under various conditions.

[0117] Therefore, after the rubber main spring is vulcanized with the inner and outer sleeves, the rubber cools and shrinks, causing tensile stress in the molecules. When the main spring is subjected to load during operation, the stress distribution on different sides of the main spring structure is uneven, which often causes the chemical chain between molecules to break, resulting in cracks in the product. The main spring diameter reduction treatment can make the rubber molecules have pre-compressive stress. At the same time, by adjusting the compression amount, the rubber main spring is not affected by tensile stress during operation, thereby improving the durability of the product.

[0118] In ABAQUS software, C3D8RH type units are used to divide the mesh into 19582 units, the material properties are set to Ogden model, and a "step-1 / 2" analysis step is created. The step-1 analysis step is used to set the size of the reduction. When calculating, the suspension is first reduced in diameter. Considering the requirements of the reduction process, the reduction amount of the rubber suspension is generally less than 10% of the thickness of the outer ring of the main spring, and the buffer thickness of the rubber jacket is 2mm. Therefore, the reduction amount is 0.1mm, 0.125mm, 0.15mm, and 0.2mm.

[0119] Then use step-2 to set the displacement load. When performing the diameter reduction process, set a displacement of 6mm in the V direction of the suspension local coordinate system. The model after the setting is completed is as follows: Fig.11 shown.

[0120] Table 1-10 Effect of diameter reduction on stiffness and fatigue life

[0121]

[0122] It can be concluded from the data in the above table that as the reduction amount increases, the stiffness value and the effective tensile strain value both increase.

[0123] [Polynomial fitting linear relationship]

[0124] Under the premise of analyzing the structural parameters of the rubber suspension, the width and length of the rubber block and the angle between two adjacent rubber blocks have a greater impact on the stiffness value, while the distance and the reduction have a smaller impact, and the range of values ​​is greatly affected by the suspension structure. In order to control the deviation of the stiffness value near the target stiffness value and thus narrow the range of parameter values, the least squares method is used to fit the data in Matlab for the parameter values ​​with greater influence, and a quadratic polynomial function is fitted, such as Fig.12 (a), (b), and (c) are the relationships between the parameter values ​​and the stiffness Kv under each parameter variable.

[0125] The fitting results are as follows:

[0126]

[0127] The stiffness value under this parameter can be predicted based on the fitting curve. According to the stiffness requirements, the range of the above three parameters can be appropriately narrowed according to the error range, which is conducive to further orthogonal testing. According to the stiffness requirements within the range of 480±15%, the stiffness value can range from 408≤Kv≤552. The rubber block value range obtained by calculating the suspension parameters using quadratic polynomials (1-4), (1-5), and (1-6) is shown in formulas (1-7), (1-8), and (1-9), all in mm.

[0128] 13.22≤W≤17.33 (1-7)

[0129] 37.81≤L≤49.33 (1-8)

[0130] 67.8°≤θ≤90.27° (1-9)

[0131] In order to facilitate the operation during modeling, the obtained parameter range is rounded. In addition, the length of the rubber block is limited by the suspension structure and the maximum value is taken, that is, the right end point in formula (1-8) is 44mm; the width, length, and angle of the suspension rubber block after value adjustment are shown in formulas (1-10), (1-11), and (1-12).

[0132] 13≤W≤17 (1-10)

[0133] 38≤L≤44 (1-11)

[0134] 68°≤θ≤90° (1-12)

[0135] In addition, the range of values ​​of the distance D between the rubber block and the upper surface of the inner ring and the diameter reduction of the suspended outer ring are as shown in formulas (1-13) and (1-14).

[0136] 0≤D≤4 (1-13)

[0137] 0.1≤r≤0.2 (1-14)

[0138]

Orthogonal Experimental Design

[0139] After obtaining the relationship between the suspension structure parameters and the reduction amount on the V-direction stiffness and fatigue life of the suspension, an orthogonal test design was carried out with the design of the V-direction stiffness of the suspension to reach the preset value as the constraint condition and the goal of maximizing its fatigue life. Under the design type, the number of factors was selected as 5. The experiment had 5 determined control factors, namely the width (W), length (L), angle (θ) of the rubber block connecting the inner and outer ring rubbers in the rubber main spring, the length from the upper surface of the inner ring (D) and the reduction amount (r). The orthogonal table is represented as L27 (35) in Minitab. A 3-level design was selected, and each factor had 3 levels, that is, the range of parameter values, as shown in the level list of each factor in Table 1-11 below. When designing the header of the orthogonal table, it is necessary to consider whether there is an interaction between the factors. If there is an interaction, a mixed level orthogonal table needs to be used to arrange the experiment. This experiment does not consider the interaction between factors, and the order of the header design does not affect the test results.

[0140] Table 1-11 List of levels of each factor

[0141]

[0142] According to Table 1-11, the number of runs of the orthogonal test arrangement is 27. Each set of test parameters is different, corresponding to 27 rubber suspension models, as shown in Table 1-12.

[0143] Table 1-12 5-factor 3-level orthogonal test table

[0144]

[0145]

[0146] First, the model parameters were modified in Catia software, and then imported into Abaqus software for finite element simulation, material setting, meshing, analysis step setting, contact setting, constraint conditions, and load application. After the finite element simulation of these 27 models was completed, the relevant test results were recorded in orthogonal tables 1-13.

[0147] Table 1-13 Orthogonal experiment results data

[0148]

[0149]

[0150] In the Hyperstudy platform, a prediction model is built based on the application of existing design data in Excel spreadsheets, that is, there is no simulation model, and a partial factor DOE analysis is performed. The relevant test data are given in Tables 1-8 and 1-9. The key design steps are:

[0151] (1) Define input variables: There are five variables in total, namely W, L, θ, D, and r, and enter the upper and lower limits of the parameters;

[0152] (2) Define output responses: Resp-Kv, Resp-Nf;

[0153] (3) Edit the matrix: Add 16 evaluations in the Add Action task, which is the experimental data input.

[0154] Furthermore, the post-processing module is used to obtain the sensitivity of the design variables to the design response in different value ranges. Using sensitivity analysis, it is possible to determine which value ranges of the design variables have a high sensitivity to the design response, which helps to determine the optimal value range of the design variables and improve system performance and stability.

[0155] In the Hyperstudy platform, the sensitivity of design variables to responses is usually displayed through a Pareto chart. The Pareto chart reflects the contribution percentage of each design variable to the response, and is presented in the form of a bar chart. The height of the bar chart represents the degree of contribution. By comparing the sensitivity of design variables in different intervals, the optimal interval range for optimization can be determined, which helps to select the most influential design variable range. Fig.13 , Fig.14 It is the sensitivity of the input variable to the output response, and based on the above-mentioned suspension parameters, V-direction stiffness Kv and fatigue life Nf, a reasonable interval is carefully selected as the value range of the design variable to provide a reference for multi-objective optimization.

[0156] Starting from the W factor (rubber block width), the experiments under the W factor level 1 are uniformly recorded as W1, and in the orthogonal table 1-12, they are 1, 4, 7, 10, 13, 16, 19, 22, and 25; the experiments under the W factor level 2 are uniformly recorded as W2, and in the orthogonal table, they are 2, 5, 8, 11, 14, 17, 20, 23, and 26; the experiments under the W factor level 3 are uniformly recorded as W3, and in the orthogonal table, they are 3, 6, 9, 12, 15, 18, 21, 24, and 27; L, θ, D, and r can be obtained in the same way. Sum the experimental indicators corresponding to the three different levels of the W factor respectively, and then make the level values ​​respectively, recorded as Kx1, Kx2, and Kx3, respectively. The calculated results are shown in Tables 1-14 and 1-15.

[0157] Table 1-14 Optimal combination table of stiffness orthogonal test

[0158]

[0159] Therefore, the orthogonal test method shows that when the rubber suspension meets the stiffness requirements, the optimal parameter combination of the rubber suspension is a rubber block width of 17 mm, a length of 44 mm, an angle of 68° between two adjacent rubber blocks, a distance of 4 mm, and a reduction of 0.2 mm.

[0160] Table 1-15 Fatigue life orthogonal test optimal level combination table

[0161]

[0162] Therefore, the orthogonal test method shows that the optimal structural parameter combination for improving the fatigue life of the rubber suspension is a rubber block width of 13 mm, a length of 41 mm, an angle of 90° between two adjacent rubber blocks, a distance of 0 mm, and a diameter reduction of 0.2 mm.

[0163] The two sets of optimal parameter combinations were modeled in Catia software and then imported into ABAQUS for FEA analysis. The obtained rubber suspension stiffness and fatigue life are shown in Table 1-16 below.

[0164] Table 1-16 FEA analysis results of optimal combination

[0165]

[0166] According to the orthogonal table and the results analysis of the optimal combination 1 and the optimal combination 2 in Table 1-16, the stiffness value of combination 1 is slightly different from the target stiffness value, with a difference of 3.12%, and the fatigue life exceeds the average value of the model data in the orthogonal experimental table in Table 1-13; the stiffness value of combination 2 is significantly different from the target stiffness value, with a difference of -23.87%, and the error of the difference is greater than 480±15%.

[0167] Therefore, the manufacturing method of the present invention obtains a combination of rubber suspension parameters when the fatigue life value is maximized while meeting the stiffness requirements. At the same time, the powertrain rubber suspension of the present invention is compared with the powertrain rubber suspension currently on the market. The fatigue life value obtained in the analysis is improved by more than 10%.

[0168] The present invention and its embodiments are described schematically above, which is not restrictive. The drawings show only one embodiment of the present invention, and the actual structure is not limited thereto. Therefore, if a person skilled in the art is inspired by it and creatively designs a structure and an embodiment similar to the technical solution without departing from the purpose of the invention, they shall all fall within the protection scope of the present invention.

Claims

1. A powertrain rubber suspension, comprising a main spring, an inner sleeve and an outer sleeve, wherein the inner ring of the main spring is assembled with the metal inner sleeve by vulcanization, and the outer ring is assembled with the metal outer sleeve by vulcanization, characterized in that: The structural parameters of the main spring satisfy the following ranges: 1) width W of the rubber block: 13.22mm≤W≤17.33mm; 2) length L of the rubber block: 37.81mm≤L≤49.38mm; 3) angle θ between two adjacent rubber blocks: 67.8°≤θ≤90.27°; 4) distance D between the rubber block and the upper surface of the inner ring of the main spring: 0≤D≤4mm; 5) reduction in diameter r between the outer ring of the main spring and the outer casing during vulcanization: 0.1mm≤r≤0.2mm.

2. The powertrain rubber mount according to claim 1, characterized in that: The structural parameter combination of the main spring is: W=17mm, L=44mm, θ=68°, D=4mm, and r=0.2mm.

3. A method for manufacturing a powertrain rubber mount as claimed in claim 1 or 2, characterized in that: The following steps are involved: (a) Analyze the dimensions of the inner and outer rings of the main spring, and select the rubber block width W, length L, angle θ, distance D and reduction r as design parameters; (b) Decouple the design parameters and design the dynamic and static stiffness so that the decoupling target is greater than 80%, and the stiffness values ​​in the local coordinate system UVW are met: 300N / mm in the U direction, 480N / mm in the V direction, and 120N / mm in the W direction; (c) Establish a binomial function of the rubber block parameters W, L, θ and the stiffness value Kv, predict the stiffness value through the curve and narrow the parameter range; (d) Design an orthogonal test with 5 factors and 3 levels, calculate the stiffness and fatigue life of 27 groups of parameter combinations, and screen the optimal level combination that meets the stiffness target and maximum fatigue life.

4. The method according to claim 3, characterized in that: In step (a), within the range of the included angle θ of 67.8° to 90.27°, the angle of the rubber block is adjusted at intervals of 5°, and the other parameters are kept unchanged, and models numbered (i=1-8) are generated in the Catia software.

5. The manufacturing method according to claim 4, characterized in that: In step (a), within the distance D of 0-4 mm, the main spring boss position is adjusted at intervals of 1 mm, and the other parameters are kept unchanged, and a model numbered (i=1-5) is generated in the Catia software.

6. The method according to claim 3, characterized in that: In step (b), perform the following operations in ABAQUS software: use C3D8RH units to divide the grid, with a total of 19582 units; set the material properties to Ogden model; create analysis steps step-1 and step-2: step-1 sets the reduction amount r, whose value is less than 10% of the thickness of the outer ring of the main spring; step-2 applies a 6mm displacement load in the V direction of the local coordinate system to complete the reduction process.

7. The method for manufacturing a powertrain rubber mount according to claim 3, characterized in that: The parameter values ​​are fitted using the least squares method in Matlab to obtain a quadratic polynomial function: The fitting results are as follows:

8. The method for manufacturing a powertrain rubber mount according to claim 7, characterized in that: According to the stiffness requirement within the range of 480±15%, the rubber block value ranges obtained by calculating the suspension parameters using quadratic polynomials (1-4), (1-5), and (1-6) are as follows (1-7), (1-8), and (1-9), all in mm: 13.22≤W≤17.33 (1-7) 37.81≤L≤49.33 (1-8) 67.8°≤θ≤90.27° (1-9).

9. The method for manufacturing a powertrain rubber mount according to claim 3, characterized in that: The obtained parameter range is rounded, and the rubber block length L takes the maximum value; the width, length, and angle of the suspension rubber block after rounding are as shown in formulas (1-10), (1-11), and (1-12): 13≤W≤17 (1-10) 38≤L≤44 (1-11) 68°≤θ≤90° (1-12) The distance D between the rubber block and the upper surface of the inner ring and the range of values ​​of the diameter reduction of the suspended outer ring are as shown in formulas (1-13) and (1-14); 0≤D≤4 (1-13) 0.1≤r≤0.2 (1-14)。 10. A vehicle, characterized in that: The invention comprises the powertrain rubber suspension as claimed in any one of claims 1 to 2.

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