Bending-resistant multi-connecting-rod rear suspension pull rod structure

Abstract

The invention relates to the technical field of multi-connecting-rod rear suspension pull rods, and discloses an anti-bending multi-connecting-rod rear suspension pull rod structure which comprises a pull rod body and a lining plate, the cross section of the pull rod body and the cross section of the lining plate are both in a U shape, the lining plate is arranged on the inner side of the pull rod body, and a lining plate web and a pull rod web are attached and provided with corresponding mounting holes. The pull rod body and the inner lining plate are fixed through the connecting piece, and rigid connection in a non-welding mode is formed. The inner lining plate is arranged on the inner side of the pull rod body, the pull rod body and the inner lining plate are fixed through the connecting piece, rigid connection in a non-welding mode is formed, the structure of the pull rod body is optimally designed on the basis of a traditional stamping welding piece structure, and the structural defects of bending and breaking of the pull rod are overcome from the anti-torsion characteristic of the section; the problem that the pull rod is prone to deformation or breakage due to the fact that the pull rod of the rear suspension system bears large compressive stress under the limiting working condition, and particularly when lateral impact force is large, the bending strength is insufficient is solved.

Description

Technical Field

[0001] The invention relates to the technical field of multi-link rear suspension tie rods, in particular to a bending-resistant multi-link rear suspension tie rod structure. Background Art

[0002] At present, multi-link rear suspension is widely used, and front McPherson and rear four-link, front double wishbone and rear five-link are all mainstream suspension structures. Because the multi-link structure requires a large layout space and is heavy, it affects the economy of the vehicle. Especially for new energy vehicles, a larger layout space will take up more battery space. Therefore, higher requirements are put forward for the structure and materials of the suspension structural parts, which are required to meet the mechanical properties and plastic deformation under various working conditions; they must also ensure the lightweight and minimized space size of the components, minimize the weight of the vehicle, and ensure the layout space of other components.

[0003] The tie rod is an important part of the multi-link rear suspension. One end is connected to the subframe and the other end is connected to the steering knuckle, providing basic structural support to ensure the wheel posture. During the operation of the vehicle, in addition to the impact force from all directions of the vehicle, it also has to withstand torsional forces under various conditions. For tie rods arranged horizontally or nearly horizontally, after load analysis, the bending force on the tie rod body during lateral impact is the largest. Therefore, from the perspective of structural design, it is necessary to ensure that the body has sufficient compressive strength (i.e., buckling reaction force).

[0004] There are two types of tie rod body structures that are widely used at present. One is stamping parts; the other is to weld reinforcement plates on the basis of stamping parts to enhance the compressive strength of the body. However, this structure still has some defects. First, there is the existence of welding heat-affected zone, which affects the stress of the body; second, under extreme working conditions, a simple strengthening solution is still difficult to meet the requirements. The compressive stress of the tie rod of the rear suspension system is relatively large, which is a great test for the simple stamping and welding structure, bringing challenges and after-sales problems to the structure under extreme conditions. Summary of the invention

[0005] In view of the deficiencies in the prior art, the purpose of the present invention is to provide a bending-resistant multi-link rear suspension tie rod structure, wherein an inner lining plate is arranged on the inner side of the tie rod body, and the web of the inner lining plate and the web of the tie rod are fitted together and corresponding mounting holes are arranged, and the tie rod body and the inner lining plate are fixed by connecting parts to form a non-welded rigid connection, and the tie rod body structure is optimized and designed based on the traditional stamping and welding structure, and the bending and fracture structural defects of the tie rod are solved from the perspective of the torsional properties of the cross section.

[0006] In order to achieve the above object, the present invention is implemented through the following technical solutions:

[0007] A bending-resistant multi-link rear suspension tie rod structure includes a tie rod body and an inner lining plate, wherein the cross-sections of the tie rod body and the inner lining plate are both U-shaped, and the inner lining plate is arranged inside the tie rod body, the web of the inner lining plate and the web of the tie rod are fitted and provided with corresponding mounting holes, and the tie rod body and the inner lining plate are fixed by a connecting piece to form a rigid connection in a non-welding form.

[0008] As a further implementation method, the inner lining plate also includes an inner lining plate wing connected to both sides of the inner lining plate web, and the tie rod body also includes a tie rod wing connected to both sides of the tie rod web, and the inner lining plate wing is fitted to the inner side of the tie rod wing to form a clearance fit.

[0009] As a further implementation, through holes are provided at both ends of the pull rod body, and an outer bushing and an inner bushing are sequentially pressed into the inner side of the through holes.

[0010] As a further implementation method, both ends of the inner tube of the inner bushing are provided with knurling structures to increase the friction coefficient of the joint surface.

[0011] As a further implementation method, the inner lining plate and the tie rod body are both formed by stamping, and the stamping outer fillet radius of the inner lining plate is larger than the stamping inner fillet radius of the tie rod body.

[0012] As a further implementation, the connecting piece uses a metal hexagonal flange bolt and a pressure-bearing surface toothed locking nut.

[0013] As a further implementation, the thickness of the inner lining plate is not greater than the thickness of the pull rod body.

[0014] As a further implementation, a plurality of the mounting holes are arranged on the web of the inner lining plate and the web of the tie rod along the length direction.

[0015] As a further implementation, weight-reducing holes are provided on the web of the inner lining plate.

[0016] As a further implementation, the material grade of the pull rod body is not lower than the material grade of the lining plate.

[0017] The beneficial effects of the present invention are as follows:

[0018] 1. The present invention arranges an inner lining plate on the inner side of the tie rod body, and the web of the inner lining plate and the web of the tie rod are fitted and provided with corresponding mounting holes, and the tie rod body and the inner lining plate are fixed by a connecting piece to form a rigid connection in a non-welded form. On the basis of the traditional stamping and welding structure, the tie rod body structure is optimized and designed, and the bending and fracture structural defects of the tie rod are solved from the perspective of the torsional properties of the cross section, and the compressive stress on the tie rod of the rear suspension system under extreme working conditions is relatively large, which puts a great test on the simple stamping and welding structure, especially when the lateral impact force is large, and the bending strength is insufficient, which easily causes the tie rod to deform or fracture, thereby increasing the problem of after-sales failures.

[0019] 2. The stamped outer fillet radius of the inner lining plate of the present invention is larger than the stamped inner fillet radius of the tie rod body, ensuring that the tie rod and the inner lining plate are reliably connected at the R angle without interference; the present invention does not open holes on the tie rod wing plate and the inner lining plate wing plate, thereby increasing the risk of deformation and cracking under stress; the tie rod body and the inner and outer bushings are pressed together instead of circumferential welding, thereby avoiding the influence of the heat-affected zone on the stress of the body. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The accompanying drawings in the specification, which constitute a part of the present invention, are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute improper limitations on the present invention.

[0021] Figure 1 Schematic diagram of the anti-bending multi-link rear suspension tie rod structure in an embodiment of the present invention;

[0022] Figure 2 is an exploded view of a bending-resistant multi-link rear suspension tie rod structure in an embodiment of the present invention;

[0023] Figure 3 is a cross-sectional view of a bending-resistant multi-link rear suspension tie rod structure in an embodiment of the present invention;

[0024] Figure 4 It is a tooth view of the end face of the inner tube of the bushing in an embodiment of the present invention.

[0025] In the figure: the distances or sizes between parts are exaggerated to show the positions of various parts, and the schematic diagram is for reference only.

[0026] Among them: 1: tie rod body, 2: inner lining plate, 3: outer bushing, 4: inner bushing, 5: hexagonal flange bolt, 6: hexagonal flange nut; 11. tie rod wing plate, 12. tie rod web plate, 21. inner lining plate wing plate, 22. inner lining plate web plate. DETAILED DESCRIPTION

[0027] It should be noted that the following detailed descriptions are illustrative and intended to provide further explanation of the present invention. Unless otherwise specified, all technical and scientific terms used in the present invention have the same meanings as those commonly understood by those skilled in the art to which the present invention belongs.

[0028] Embodiment 1

[0029] In a typical embodiment of the present invention, reference is made to Figure 1-Figure 4 As shown, a bending-resistant multi-link rear suspension tie rod structure includes a tie rod body 1 and an inner lining plate 2. The cross-sections of the tie rod body 1 and the inner lining plate 2 are both U-shaped. The inner lining plate 2 is arranged on the inner side of the tie rod body. The inner lining plate web 22 and the tie rod web 12 are fitted and provided with corresponding mounting holes. The tie rod body 1 and the inner lining plate 2 are fixed by connecting parts to form a rigid connection in a non-welded form.

[0030] For the pull rod body 1, the torsion and bending resistance are closely related to the section inertia moment. Under the condition of constant bending moment and material, the greater the section inertia moment, the smaller the bending stress. For the commonly used U-shaped section, the simplified calculation result of the section inertia moment is as shown in Formula 1:

[0031] Formula 1:

[0032] It can be seen from formula 1 that the section inertia W is proportional to the size h, width b, and thickness t. When the section size is constant, the larger the thickness t, the larger the section inertia, and thus the better the bending resistance.

[0033] Therefore, this embodiment adds an inner lining plate 2 similar in shape to the tie rod body 1, and the tie rod body is integrally combined. The connection can be made by riveting or bolting to ensure strength and reliability, improve the bending resistance of the tie rod body, and solve the problem that the tie rod of the rear suspension system is subjected to large compressive stress under extreme working conditions, which is a great challenge to simple stamping and welding structures.

[0034] like Figure 1 and Figure 2 As shown, the inner lining plate 2 includes an inner lining plate web 22 and inner lining plate wing plates 21 connected to both sides of the inner lining plate web 22 , and the tie rod body 1 includes a tie rod web 12 and tie rod wing plates 11 connected to both sides of the tie rod web 12 .

[0035] like Figure 2 As shown, mounting holes are correspondingly provided on the tie rod web 12 and the inner lining plate web 22, and the inner lining plate web 22 is mounted on the inner side of the tie rod web 12 through a connecting piece.

[0036] like Figure 2As shown, the fixing points of the mounting holes of the tie rod body 1 and the web 2 should be preferentially arranged on the flat web, and the mounting points should be arranged longitudinally and transversely according to the size of the web. In this example, the longitudinal mounting spacing is 60mm, and the transverse mounting spacing is 30mm. For cross-sectional positions with smaller transverse dimensions, the mounting points can be arranged in a single row. The opening size of the fixing point is ≤φ8.2mm, and the series of φ5.2mm, φ6.2mm, and φ8.2mm are selected. The belly surface of the tie rod body 1 of this embodiment is a plane. If it is a multi-plane or curved structure, in principle, the inner lining plate 2 should also have such a multi-plane or curved structure.

[0037] In order to ensure the reliability of the connection between the tie rod body 1 and the inner lining plate 2, priority is given to the use of metal hexagonal flange bolts and nuts, and priority is given to the use of locking nuts with teeth on the pressure-bearing surface, that is, the connecting parts are hexagonal flange bolts 5 and hexagonal flange nuts 6 with teeth on the pressure-bearing surface, and the non-welded rigid connection of the tie rod body 1 and the inner lining plate 2 is achieved through the connecting parts. Considering that the flange side of the tie rod body is a curved surface and the alternating stress is complex, the tie rod body 1 and the inner lining plate 2 do not have holes on the flange side, reducing the risk of stress deformation and cracking at the opening position and avoiding the risk of fatigue stress damage on the curved surface.

[0038] like Figure 1 and Figure 2 As shown, in order to ensure dimensional consistency and assembly accuracy, the main body and the inner lining plate are both stamped to improve product accuracy and assembly convenience. The inner lining plate wing 21 is fitted to the inner side of the tie rod wing 11, so that the inner lining plate 2 and the tie rod body 1 are matched with a small gap on the wing surface.

[0039] like Figure 1 and Figure 2 As shown, through holes are provided at both ends of the tie rod body 1, and outer bushings 3 and inner bushings 4 are pressed in turn inside the through holes. The tie rod body 1 and the inner and outer bushings are pressed together without circumferential welding to avoid the influence of the heat-affected zone on the stress of the body. In order to avoid slippage between the tie rod inner bushing and the connecting bolts of the rear subframe, knurled structures are used at both ends of the inner tube of the inner bushing 4 to increase the friction coefficient of the joint surface and reduce the risk of slippage when installing the fixing bolts, such as Figure 4 As shown, the height dimension of the knurled structure is 0.5 mm.

[0040] In order to ensure the consistency of size and assembly accuracy, the tie rod body 1 and the inner lining plate 2 are both formed by stamping to improve product accuracy and assembly convenience.

[0041] In order to reduce the risk of interference between the web and wing plates of the tie rod body 1 and the inner lining plate 2 at the R angle, the stamped outer fillet radius of the inner lining plate is larger than the inner fillet radius of the tie rod body stamped part.

[0042] To ensure the vehicle is lightweight, the thickness of the inner lining should not be greater than the thickness of the tie rod body while ensuring the strength. Figure 3 shown.

[0043] Furthermore, the rod body 1 and the inner lining plate 2 are made of the same material, or the inner lining plate 2 has a material property one level lower than that of the rod body 1. The thickness of the inner lining plate 2 is in principle smaller than that of the rod body 1, which can be specifically determined based on CAE load analysis.

[0044] Considering the lightness of the parts, the inner web can have weight-reducing holes on the belly surface, and the hole size should be as small as possible and as far away from the R angle area as possible. No holes are opened on the belly surface of the tie rod body 1, and no holes are opened on the wing surfaces of the tie rod body 1 and the inner web 2.

[0045] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A bending-resistant multi-link rear suspension tie rod structure, characterized in that: It includes a tie rod body and an inner lining plate, the cross-sections of the tie rod body and the inner lining plate are both U-shaped, the inner lining plate is arranged on the inner side of the tie rod body, the web of the inner lining plate and the web of the tie rod are fitted and corresponding mounting holes are arranged, the tie rod body and the inner lining plate are fixed by connecting parts to form a rigid connection in a non-welding form.

2. The anti-bending multi-link rear suspension tie rod structure according to claim 1, characterized in that: The inner lining plate also includes inner lining plate wings connected to both sides of the inner lining plate web, and the tie rod body also includes tie rod wings connected to both sides of the tie rod web. The inner lining plate wings are fitted to the inner side of the tie rod wings to form a clearance fit.

3. The anti-bending multi-link rear suspension tie rod structure according to claim 1, characterized in that: Through holes are arranged at both ends of the pull rod body, and an outer bushing and an inner bushing are pressed in sequence inside the through holes.

4. The anti-bending multi-link rear suspension tie rod structure according to claim 3, characterized in that: Both ends of the inner tube of the inner bushing are arranged with knurling structures to increase the friction coefficient of the joint surface.

5. The anti-bending multi-link rear suspension tie rod structure according to claim 2, characterized in that: The inner lining plate and the pull rod body are both formed by stamping, and the stamping outer fillet radius of the inner lining plate is larger than the stamping inner fillet radius of the pull rod body.

6. The anti-bending multi-link rear suspension tie rod structure according to claim 1, characterized in that: The connecting piece adopts a metal hexagonal flange bolt and a pressure-bearing surface toothed locking nut.

7. The anti-bending multi-link rear suspension tie rod structure according to claim 1, characterized in that: The thickness of the inner lining plate is not greater than the thickness of the pull rod body.

8. The anti-bending multi-link rear suspension tie rod structure according to claim 7, characterized in that: A plurality of mounting holes are arranged on the web of the inner lining plate and the web of the tie rod along the length direction.

9. The anti-bending multi-link rear suspension tie rod structure according to claim 1, characterized in that: The web of the inner lining plate is provided with weight-reducing holes.

10. The anti-bending multi-link rear suspension tie rod structure according to claim 1, characterized in that: The material grade of the pull rod body is not lower than the material grade of the inner lining plate.

Images