An air suspension guide arm structure based on bamboo bionics and its design method

Abstract

The invention discloses an air suspension guide arm structure based on bamboo bionics and a design method thereof, which belongs to the field of lightweight automobile air suspension. The left section of the guide arm is an external variable cross-section structure, and the right section is a bionic bamboo structure with an external rectangular cross-section consistent with an internal variable cross-section hole; the external cross-section shape is rectangular, and the internal hollowed-out cross-section shape is rectangular plus an elliptical wide line; each section of the right section is straight on the outside, and the internal hollowed-out cross-section shape changes with the change of the length of the straight section; a rib plate arm is placed at the aperture of the right section of the guide arm and at both sides of the aperture; the spacing between the 12 rib plates of the right section of the guide arm is not equal, which belongs to the bionic bamboo internal bamboo rib plate variable spacing guide arm. Compared with the traditional Z-shaped guide arm, the bionic bamboo configuration provided by the invention has good lightweight characteristics, and the structure has better strength and rigidity while greatly reducing weight, and is a brand-new Z-shaped guide arm structure.

Description

Technical Field

[0001] The invention belongs to the technical field of lightweight automobile air suspension, and in particular relates to an air suspension guide arm structure based on bamboo bionics and a design method. Background Art

[0002] With the update and iteration of technology, people's requirements for vehicle weight, comfort, adaptability and other performance indicators are constantly increasing. Air suspension has been widely used in vehicles due to its excellent structural performance. At present, air suspension is widely used in road transport vehicles in some countries. As the use rate of air suspension gradually increases, it has also attracted many scholars to study its lightweight.

[0003] As the force transmission and guiding rod system and elastic element in the air suspension structure, the guide arm plays an important role in transmitting various forces and moments. However, it still has the problem of being too heavy. In order to achieve the goal of reducing the weight of the guide arm, the lightweight design of the guide arm is realized through the combination of bionic design and structural optimization.

[0004] Structural bionic design refers to starting from the macroscopic or microscopic level of the organism, studying the morphology, structure, material, function, etc. of the organism, and on the premise that the organism and the engineering object are highly similar, conducting design concepts or constructing mathematical and mechanical models, extracting biological characteristics for bionic design, and achieving design goals in the engineering object; structural optimization refers to obtaining the optimal force transmission path or optimal parameters of the structure through topological optimization and parametric optimization.

[0005] The optimization of the existing air suspension structure optimization guide arm is generally achieved through leaf spring material selection, leaf number selection, thickness design and variable section control, and has not been expanded in terms of cross-sectional shape and new configuration. There is a lack of overall optimization design of the air suspension guide arm, especially a comprehensive method for lightweight design. Summary of the invention

[0006] In view of the above technical problems, the present invention proposes an air suspension guide arm based on bamboo bionics and a design method thereof, which achieves a significant weight reduction while the structure has better strength and rigidity.

[0007] In order to solve the above technical problems, the present invention adopts the following technical solutions:

[0008] An air suspension guide arm based on bamboo bionics, characterized by comprising:

[0009] The upper guide arm comprises an upper overlapping contact section, a first variable cross-section section extending from the upper overlapping contact section to the left end, and a hinged end curled upward from the first variable cross-section section into a hole shape;

[0010] The lower guide arm comprises: a lower overlapping contact section located below and in contact with the upper overlapping contact section, a second variable cross-section section extending from the lower overlapping contact section to the left end, a hinged end curled upward from the second variable cross-section section to form a hole in synchronization with the upper guide arm; a vertical section extending downward from the lower overlapping contact section, and an extension section extending rightward from the vertical section; arc transition sections are provided between the lower overlapping contact section and the vertical section, and between the vertical section and the extension section;

[0011] The upper overlapping contact section and the lower guide arm are all bionic bamboo structure sections with the same outer cross-section in the direction of extending rightward from the lower overlapping contact section. Each bionic bamboo structure section is provided with a cross-sectional hole of a rectangle plus an arc-shaped width curve.

[0012] In the above technical solution, the first variable cross-section segment and the second variable cross-section segment are both variable cross-section rectangular segments whose edges gradually become thinner from the boundaries of their respective overlapping contact segments to the left.

[0013] In the above technical solution, the bionic bamboo structure segments have consistent outer cross-sections and are all rectangular structures that are connected to the maximum cross-section of the variable cross-section rectangular segments of the first variable cross-section segment and the second variable cross-section segment.

[0014] In the above technical solution, the length, width and / or width of the cross-sectional hole of the bionic bamboo structure segment rectangle plus arc-shaped width curve changes with the change of the length of the external straight segment or vertical segment.

[0015] In the above technical solution, the cross-sectional hole of the bionic bamboo structure segment with a rectangle plus an arc-shaped width curve is a variable cross-sectional rectangular elliptical hole, a variable cross-sectional rectangular quadratic curve hole, or a variable cross-sectional rectangular sine curve hole.

[0016] In the above technical solution, each bionic bamboo structure segment is provided with a plurality of groups of bamboo rib support structures, and each group of bamboo rib support structures is a plurality of closed transverse rectangular wide curved cross-section bamboo ribs arranged at unequal intervals.

[0017] In the above technical solution, each group of bamboo rib support structures is composed of three closed transverse bamboo ribs arranged at intervals. The thickness of the middle transverse bamboo rib is greater than the transverse bamboo ribs on both sides of the rib, and the middle transverse bamboo rib and the bamboo ribs on both sides form parallel transverse holes.

[0018] Furthermore, the bamboo rib support structure is located at the connection between the upper guide arm, the lower guide arm and the U-bolt, and the connection between the lower guide arm and the air spring, and the thickness of the rib is the largest at the aperture of the connection hole.

[0019] Furthermore, the length of the overlapping contact section of the bamboo-based bionic guide arm is greater than the diameter of the U-bolt provided thereon.

[0020] A method for designing an air suspension guide arm based on bamboo bionics, characterized by comprising the following steps:

[0021] S1. Select bamboo with a similar structure to the guide arm from nature, and extract the cross-sectional shape characteristics, variable cross-sectional characteristics, bamboo rib characteristics, and bamboo rib variable spacing characteristics of the bamboo;

[0022] S2. Bionic structure screening to determine the overall structure of the bionic bamboo guide arm: the left section of the upper guide arm and the lower guide arm is a variable cross-section section, and the right section is a variable cross-section hole section or a bionic bamboo structure section with the same appearance;

[0023] S3. Combine and optimize the above-extracted cross-sectional shape features, variable cross-sectional features, bamboo rib features and bamboo rib variable spacing features, and apply them to the bionic bamboo structure segment to determine the specific structure of the bamboo bionic structure segment: determine the shape of the variable cross-sectional hole based on the strength design, and determine the position of the bamboo rib support structure based on the optimization of the bamboo node variable pitch arrangement characteristics.

[0024] Therefore, the present invention studies a new configuration of an air suspension guide arm, and optimizes the design of the guide arm by imitating the internal cross-sectional characteristics, variable cross-sectional characteristics, bamboo node characteristics, and bamboo node variable spacing characteristics of bamboo.

[0025] The invention provides an air suspension guide arm structure based on bamboo bionics, wherein the guide arm consists of a left section external variable cross-section structure and a right section bionic bamboo structure; the right section of the guide arm has an external cross-section shape of a rectangle, and an internal hollow cross-section shape of a rectangle plus an elliptical wide line; the right section of the guide arm is bounded by an arc corner, the upper guide arm is divided into one section, and the lower guide arm is divided into three sections, each section is straight on the outside, and the internal hollow cross-section shape changes with the change of the length of the straight section; a rib plate is respectively placed at an aperture of the right section of the guide arm and at both sides of the aperture, with a total of 12 rib plates; the spacing between the 12 rib plates of the right section of the guide arm is not equal.

[0026] Compared with the existing Z-shaped guide arm structure, the present invention has the following beneficial effects: the present invention has a significant weight reduction and at the same time the structure has better strength and rigidity, and the cross-sectional shape of the right section of the guide arm is processed to imitate bamboo to improve the bending strength of the guide arm and reduce the structural mass of the guide arm; the right section of the guide arm is processed to imitate bamboo to make the cross-sectional shape variable to further reduce the mass of the structure; and variable-spacing bamboo ribs are added to the hollowed-out part of the right section of the guide arm to improve the shear resistance and lateral compressive resistance of the overall guide arm structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is an overall structural diagram of the air suspension guide arm based on bamboo bionics of the present invention.

[0028] Figure 2The present invention is a structural diagram of an air suspension using the bamboo bionics-based air suspension guide arm.

[0029] Figure 3 It is a schematic diagram of the internal variable cross-section of the air suspension guide arm based on bamboo bionics of the present invention.

[0030] Figure 4 It is a structural diagram of the variable cross-section area of ​​the guide arm based on bamboo bionics of the present invention.

[0031] Figure 5 The invention is a schematic diagram of the cross-section of the elliptical rectangular holes of the right end sections of the variable cross-section section of the air suspension guide arm based on bamboo bionics.

[0032] Figure 6 The invention discloses a bamboo-based air suspension guide arm with a variable cross-section section having different width curve cross-section hole diagrams at the right end of each section.

[0033] Figure 7 It is a front view of the rib plate structure position and thickness of the air suspension guide arm based on bamboo bionics of the present invention.

[0034] Figure 8 The figure is a rib position and thickness profile diagram (vertical profile along the centerline position) of the air suspension guide arm based on bamboo bionics of the present invention.

[0035] Fig. 9 It is a schematic diagram of the rib structure shape of the air suspension guide arm based on bamboo bionics of the present invention.

[0036] Fig.10 The invention discloses a flow chart of a design method for an air suspension guide arm structure based on bamboo bionics, which includes, in sequence, screening bionic structures, determining bionic prototypes, performing cross-section bionic design based on bionic prototypes, variable cross-section bionic design, and rib bionic design in which the rib positions are determined by topological optimization.

[0037] Fig.11 It is a schematic diagram of the original structure and characteristic structure screening of the bionic bamboo of the present invention. DETAILED DESCRIPTION

[0038] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the following Figure 1-11 The present invention is further described in detail with reference to the embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0039] Embodiment 1:

[0040] The present invention provides a bamboo-based air suspension Z-shaped guide arm, which belongs to the field of lightweight automobile air suspension. The guide arm 100 is related to the overall structure of the air suspension. Figure 1 As shown, its application on the guide arm connecting beam 600 of the automobile suspension system is as follows Figure 2 shown.

[0041] like Figure 1 As shown, the guide arm 100 includes an upper guide arm and a lower guide arm, the upper guide arm and the lower guide arm have overlapping contact sections (upper overlapping contact section 3 and lower overlapping contact section 4) arranged in upper and lower overlapping contact, the upper guide arm and the lower guide arm extend from the overlapping contact sections to the left end in a substantially horizontal direction to form a variable cross-section section 2 at the same time, the upper guide arm and the lower guide arm curl upward from the variable cross-section section 2 to the left end to form a hinged end 1 that overlaps with each other, the lower guide arm first extends downward from the overlapping contact section (lower overlapping contact section 4) to form a substantially vertical vertical section 5, and then extends from the vertical section 5 to the right end in a substantially horizontal direction to form a Z-shaped extension section 6, the connection between the vertical section 5 and the lower overlapping contact section 4 is a circular arc transition section 51, and the connection between the vertical section 5 and the extension section 6 is a circular arc transition section 52.

[0042] like Figure 2 As shown, the hinged end 1 of the upper guide arm at the left end of the guide arm 100 is hinged at the bottom of the guide arm bracket 200 (the guide arm bracket 200 is fixed on the guide arm connecting beam 600), the extension section 6 extending to the right of the lower guide arm is fixed to the bottom of the air spring 400, the top of the air spring 400 is fixed on the guide arm connecting beam 600, the bottom of the air spring 400 is hinged to the telescopic shock absorber 500, and the top of the shock absorber 500 is fixed on the guide arm connecting beam 600; the upper guide arm and the lower guide arm overlapping sections (upper overlapping section 3 and lower overlapping section 4) of the guide arm 100 are fixed by U-bolts 300.

[0043] like Figure 3 and 4 The guide arm 100 is characterized in that: the guide arm 100 is bounded by the left end boundary of the U-bolt (also the left end boundary of the overlapping contact section, 311 and 410), the left end is a variable cross-section section 2, and the upper overlapping contact section 3, the lower overlapping contact section 4, the vertical section 5, the arc transition sections 51 and 52, and the extended section 6 starting from the overlapping contact section at the right end are all bionic bamboo structure sections. In the upper overlapping contact segment 3, the lower overlapping contact segment 4, the basic vertical segment 5, the arc transition segments 51 and 52, and the extended segment 6 at the right end, each segment is straight on the outside and has hollowed-out cross-sectional shapes with axially different curved cross-sectional holes (hole 30 in the upper overlapping contact segment 3, hole 40 in the lower overlapping contact segment 4, hole 50 in the vertical segment 5, hole 60 in the extended segment 6, holes between the boundaries of the arc transition segment 45, and holes between the boundaries of the arc transition segment 56). The hollowed-out cross-sectional shapes of different curved widths change with the change of the length of the axial straight segment of the hole, presenting an internal variable-section guide cylinder with a bionic bamboo structure.

[0044] like Figure 1-5As shown, the external cross-section shape of the internal variable-section guide tube of the bionic bamboo structure is a rectangle with a consistent cross-section, and the internal hollow cross-section shape is a rectangle with a variable cross-section plus an elliptical wide line (such as Figure 5 as shown); Figure 6 As shown in FIG. 1 , since the internal hollow cross-section of the bamboo is quasi-circular, and the middle hollow cross-section is rectangular, the bending strength of the beam structure is high. Therefore, by changing the wide straight line of the rectangular hollow cross-section of the guide arm to different width curves, i.e., elliptical curves, sine curves, and quadratic curves, the different width curves of the cross-section holes of each bionic guide arm are as shown in FIG. Figure 6 This embodiment is as shown. Figure 6 The final selection of many curves Figure 5 A rectangle plus an elliptical wide line, that is Figure 5 However, the present invention does not exclude the protection of holes with sinusoidal, quadratic or other similar curve cross-sections.

[0045] like Figure 7-9 As shown, at least one group of bamboo rib support structures (31, 41 or 61) is arranged in each of the horizontal sections (upper overlapping section 3, lower overlapping section 4, and extended section 6) at the right end of the variable cross-section section 2 of the guide arm 100, and two groups of bamboo rib support structures 61 are arranged at intervals in the extended section 6; each group of bamboo rib support structures is three closed transverse bamboo ribs (31, 41 or 61) arranged at intervals, the thickness of the transverse bamboo rib in the middle is greater than the transverse bamboo ribs on both sides of the rib, and the transverse bamboo rib in the middle and the bamboo ribs on both sides form parallel transverse small holes. A total of 4 groups of bamboo rib structures include 12 bamboo ribs with thick walls and thin walls, which are derived from the bamboo rib structure inside the bionic bamboo. The spacing between the 12 bamboo ribs in the right section of the guide arm is not equal, that is, the spacing between the three closed transverse bamboo ribs arranged at intervals in each group of bamboo rib support structures (31, 41 or 61) is not equal. This structure is derived from the variable spacing structure of bamboo ribs inside bionic bamboo. Each bamboo rib is characterized by a hollow cross-sectional shape, that is, an elliptical rectangular hole with a rectangular plus an elliptical wide curve, such as Fig. 9 shown.

[0046] Compared with the traditional Z-shaped guide arm, the bionic bamboo configuration provided by the present invention has good lightweight characteristics. While greatly reducing the weight, the structure has better strength and rigidity. It is a brand-new Z-shaped guide arm structure.

[0047] like Fig.10 and 11 The figure shows the design method of the Z-shaped guide arm of the air suspension based on bamboo bionics.

[0048] Step 1: Select biological prototypes from nature that are similar to the guide arm structure (such as Fig.11The left and right pictures of the guide arm are used to conduct functional analysis and similarity evaluation to select the most suitable bionic prototype structure. Bamboo and the guide arm have a high degree of similarity in function, load and structure, so bamboo is selected as the bionic prototype of the guide arm structure.

[0049] Extract the structural features of the bionic prototype ( Fig.11 ), namely the internal hollow cross-section shape characteristics, variable cross-section characteristics, bamboo node characteristics, and variable spacing characteristics between bamboo nodes. The specific reference bamboo structure diagram is shown in the middle partial structure of 11, and then the guide arm is designed accordingly.

[0050] Step 2: Since the internal hollow cross-section of bamboo is quasi-circular, and the middle hollow cross-section is rectangular, the bending strength of the beam structure is high. Therefore, by changing the wide straight line of the rectangular hollow cross-section of the guide arm to curves of different widths, i.e., elliptical curves, sine curves, and quadratic curves, the cross-sections of different width curves of each bionic guide arm are shown in the figure below. Figure 6 As shown. Taking the midpoint of the wide line of the hollow rectangle in the cross section as the origin of the coordinates, the parametric equations of the left curves of each cross section are as follows:

[0051] Elliptic functions:

[0052] Sine function:

[0053] Quadratic function:

[0054] All three function curves take x∈(-a,0), Finally, the elliptical line with the best comprehensive performance is selected as the wide curve to imitate the cross-sectional shape characteristics of bamboo. The final elliptical rectangular cross-sectional shape is as follows Figure 5 shown.

[0055] Step 3: Refer to the design form of the variable-section isostress beam of the leaf spring and combine the structural characteristics of the guide arm to segment the equal-section of the guide arm. The leaf spring is usually divided into a straight section, a transition section and an isostress section. The length and thickness of the straight section are mainly determined by the assembly conditions and are located at the end and root of the leaf spring. The length and thickness of the transition section depend on the stiffness and strength constraints and are connected to the straight section. The longest section in the middle is the isostress section. Since the bamboo ribs are hollow inside, there is no need to consider installation and transition. Therefore, the right section of the guide arm is divided by the arc transition sections 51 and 52, and the upper overlapping section 3 of the upper guide arm is divided into one section, and the lower guide arm is divided into three sections (lower overlapping section 4, vertical section 5, and extended section 6) to imitate the variable-section characteristics of bamboo. The structural diagram of the variable-section area of ​​the guide arm is shown in the figure below. Figure 4 As shown, the bamboo bionic guide arm variable cross-section diagram is as follows Figure 3 shown.

[0056] Step 5: In order to explore the position of the ribs, topology optimization is used to optimize the guide arm, with the goal of minimizing the flexibility of the guide arm, that is, maximizing the stiffness of the guide arm, and the upper limit of the volume ratio of 0.1 as a constraint. The resulting topology optimization mathematical model is:

[0057] Design variables: Y = [y1, y2, ..., y n ] T ,y i ∈R N

[0058] Objective function: minA(Y)

[0059] Constraint: V≤0.1

[0060] Where: Y is the design variable, y i is the pseudo-density of the i-th unit; N is the number of units; A(Y) is the objective function; V is the volume ratio of the design space. Finally, the hollowing out of the middle of the guide arm is determined, and each group of ribs is set at the aperture to improve the shear resistance and lateral compression resistance of the guide arm to imitate the characteristics of the bamboo ribs of bamboo. The characteristics of the bamboo ribs are the hollowed-out cross-sectional shape, that is, an elliptical rectangular hole with a rectangular plus an elliptical wide curve, such as Fig. 9 shown.

[0061] Step 6: Arrange the bamboo ribs at unequal intervals to imitate the characteristics of bamboo ribs. The positions and thicknesses of the 12 ribs in the upper and lower guide arms are shown in the figure below. Figure 8 and Fig. 9 The final structure of the guide arm of the bionic bamboo is shown in Figure 1 shown.

[0062] Embodiment 2:

[0063] The present invention takes a certain 8x4 commercial vehicle composite air suspension as an example. Under the typical working condition of full load static, the maximum stress of its guide arm cannot exceed the allowable stress, i.e., 1500MPa. According to Table 1, by comparing the structural performance of the original guide arm and the bamboo bionic guide arm, it is found that the bamboo bionic guide arm has a 2.14% decrease in equivalent stress and 8.04% decrease in maximum deformation compared to the original guide arm, and the first-order prestressed constraint modal frequency increases by 30.02%, and the total mass decreases by 22.73%, achieving a significant weight reduction while having better strength and stiffness of the structure.

[0064] Table 1 Performance comparison of guide arm before and after optimization design

[0065]

[0066] It should be understood that those skilled in the art can make improvements or changes based on the above description, and all these improvements and changes should fall within the scope of protection of the appended claims of the present invention.

Claims

1. An air suspension guide arm based on bamboo bionics, characterized in that include: The upper guide arm comprises an upper overlapping contact section, a first variable cross-section section extending from the upper overlapping contact section to the left end, and a hinged end curled upward from the first variable cross-section section into a hole shape; The lower guide arm comprises: a lower overlapping contact section located below and in contact with the upper overlapping contact section, a second variable cross-section section extending from the lower overlapping contact section to the left end, a hinged end curled upward from the second variable cross-section section to form a hole in synchronization with the upper guide arm; a vertical section extending downward from the lower overlapping contact section, and an extension section extending rightward from the vertical section; arc transition sections are provided between the lower overlapping contact section and the vertical section, and between the vertical section and the extension section; The upper overlapping contact section and the lower guide arm are all bionic bamboo structure sections with the same outer cross-section in the direction of extending to the right from the lower overlapping contact section, and each bionic bamboo structure section is provided with a cross-sectional hole of a rectangular plus an arc-shaped width curve; The length, width and / or width of the cross-sectional hole of the bionic bamboo structure segment rectangle plus arc-shaped width curve changes with the change of the length of the external straight segment or vertical segment; Each of the bionic bamboo structural sections is provided with a plurality of groups of bamboo rib support structures, and each group of bamboo rib support structures is a plurality of closed transverse rectangular wide curved cross-section bamboo ribs arranged at unequal intervals.

2. The bamboo bionic air suspension guide arm according to claim 1 is characterized in that The first variable cross-section segment and the second variable cross-section segment are both variable cross-section rectangular segments whose edges gradually become thinner from the boundaries of their respective overlapping contact segments to the left.

3. The bamboo bionic air suspension guide arm according to claim 1, characterized in that The bionic bamboo structure segments have consistent outer cross-sections and are all rectangular structures that are butt-jointed with the maximum cross-sections of the variable cross-section rectangular segments of the first variable cross-section segment and the second variable cross-section segment.

4. The bamboo bionic air suspension guide arm according to claim 1, characterized in that The cross-sectional hole of the bionic bamboo structure segment with a rectangle plus an arc-shaped width curve is a variable cross-sectional rectangular elliptical hole, a variable cross-sectional rectangular quadratic curve hole, or a variable cross-sectional rectangular sine curve hole.

5. The bamboo bionic air suspension guide arm according to claim 1, characterized in that Each group of bamboo rib support structures is composed of three closed transverse bamboo ribs arranged at intervals. The thickness of the middle transverse bamboo rib is greater than the transverse bamboo ribs on both sides of the rib, and the middle transverse bamboo rib and the bamboo ribs on both sides respectively form parallel transverse small holes.

6. The bamboo bionic air suspension guide arm according to claim 1, characterized in that The bamboo rib support structure is located at the connection between the upper guide arm, the lower guide arm and the U-bolt, and the connection between the lower guide arm and the air spring, and the thickness of the rib is the largest at the aperture of the connection hole.

7. The bamboo bionic air suspension guide arm according to claim 1, characterized in that The length of the overlapping contact section of the bamboo-based bionic guide arm is greater than the diameter of the U-shaped bolt arranged thereon.

8. A method for designing an air suspension guide arm based on bamboo bionics according to any one of claims 1 to 7, characterized in that The steps include: S1. Select bamboo with a similar structure to the guide arm from nature, and extract the cross-sectional shape characteristics, variable cross-sectional characteristics, bamboo rib characteristics, and bamboo rib variable spacing characteristics of the bamboo; S2. Bionic structure screening to determine the overall structure of the bionic bamboo guide arm: the left section of the upper guide arm and the lower guide arm is a variable cross-section section, and the right section is a variable cross-section hole section or a bionic bamboo structure section with the same appearance; S3. Combine and optimize the above-extracted cross-sectional shape features, variable cross-sectional features, bamboo rib features and bamboo rib variable spacing features, and apply them to the bionic bamboo structure segment to determine the specific structure of the bamboo bionic structure segment: determine the shape of the variable cross-sectional hole based on the strength design, and determine the position of the bamboo rib support structure based on the optimization of the bamboo node variable pitch arrangement characteristics.

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