An optimization method for a limiting structure of an automobile steering knuckle

Abstract

The present invention provides an optimization method for a limiting structure of an automobile steering knuckle. A front suspension motion simulation analysis and design in the form of a double wishbone is created in software, and the steering rack stroke and tire bounce stroke of the vehicle model are substituted to obtain a complete front suspension motion simulation analysis and design model of the vehicle model. The front suspension motion simulation analysis and design model is subjected to full-working-condition motion simulation to find the specific value of the steering wheel angle limit required to ensure a safe spacing between suspension parts. Then, a matching first limiting structure and a second limiting structure are designed on the suspension lower arm and the steering knuckle, respectively. The second limiting structure is designed and fixed to the steering knuckle according to a curved surface s, where the curved surface s is the contour surface of the second limiting structure on the steering knuckle. The second limiting structure has a smooth steering limit and reduces abnormal steering noise, thereby better achieving the purpose of steering wheel angle limit.

Description

Technical Field

[0001] The present invention relates to the field of automobile design, and in particular to an optimization method for a limiting structure of an automobile steering knuckle. Background Art

[0002] Passenger cars and multi-purpose trucks are increasingly demanding more space for passengers and cargo, and the wheelbase setting is also increasing accordingly, resulting in a larger turning radius and reduced maneuverability. With the wheelbase and track remaining unchanged, designers typically optimize the turning radius by increasing the steering wheel angle. However, under extreme conditions, increasing the steering wheel angle can lead to dynamic interference between the wheels and suspension components. Many automakers address this dynamic tire interference issue by adding steering limit brackets to limit the steering wheel angle under extreme conditions. However, current steering limit measures have problems such as abnormal steering noise and abrupt limiting. Summary of the Invention

[0003] The purpose of the present invention is to provide an optimization method for a limiting structure of an automobile steering knuckle in view of the defects and shortcomings of the prior art, aiming to solve the problems in the prior art.

[0004] To achieve the above object, the technical solution adopted by the present invention is: a method for optimizing the limiting structure of an automobile steering knuckle, comprising the following steps:

[0005] Step 1. Create a double-wishbone front suspension kinematic analysis design in the software. Substitute the vehicle's steering rack travel and tire runout to obtain a complete front suspension kinematic analysis design model.

[0006] Step 2. Perform full-condition motion simulation on the front suspension motion simulation analysis and design model, find the minimum spacing between adjacent parts under all conditions, and identify the conditions where the spacing between all parts is less than the safety requirement.

[0007] Step 3. For working conditions where the spacing between parts is less than the safety requirement, first set the first limit structure on the lower arm;

[0008] Step 4. Obtain several limit points and corresponding straight lines according to the first limit structure;

[0009] Step 5. Based on the limit points and the corresponding straight lines, all adjacent straight lines are bridged in sequence by a software bridging module to obtain an irregular curved surface s;

[0010] Step 6. Fix the second limiting structure on the steering knuckle according to the curved surface s, where the curved surface s is the contour surface of the second limiting structure.

[0011] The beneficial effects of the present invention are: creating a front suspension motion simulation analysis and design in the form of a double wishbone in the software, substituting the steering rack stroke and tire bounce stroke of the vehicle model, and obtaining a complete front suspension motion simulation analysis and design model of the vehicle model, performing full-condition motion simulation on the front suspension motion simulation analysis and design model, and finding the specific value of the steering wheel angle limit required to ensure a safe distance between the suspension parts, and then designing a matching first limiting structure and a second limiting structure on the suspension lower arm and the steering knuckle respectively, and fixing the second limiting structure design to the steering knuckle according to the curved surface s, which is the contour surface of the second limiting structure on the steering knuckle, and the steering limit of the second limiting structure is smooth, reducing abnormal steering noise, thereby better achieving the purpose of steering wheel angle limit.

[0012] Furthermore, the steps of obtaining a plurality of limiting points and corresponding straight lines according to the first limiting structure are:

[0013] Step A. Divide the required limit jump stroke into n equal parts, namely G1, G2, G3...Gn;

[0014] Step B. Using a dynamic motion model to simulate the working condition corresponding to G1, find the limit point p1 on the steering knuckle corresponding to the first limit structure, and draw a straight line l1 in the horizontal plane parallel to the tire sidewall through the limit point p1;

[0015] Step C. Repeat step B. When all working conditions of G1, G2, G3…Gn are simulated, a series of limit points p1, p2, p3…pn and corresponding straight lines l1, l2, l3…ln can be obtained.

[0016] Furthermore, the adjacent parts include a tire and a lower control arm, and a tire and a stabilizer bar.

[0017] Furthermore, the first limiting structure includes a cylindrical structure and a hemispherical structure arranged at the outer end of the cylindrical structure.

[0018] Furthermore, the software for creating the dynamic motion model of the double wishbone suspension system is CATIA software. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0020] Figure 1 Schematic diagram of the front suspension dynamic motion model according to an embodiment of the present invention.

[0021] Figure 2 Schematic diagram of the relationship between p1 and l1 on the first limiting structure according to an embodiment of the present invention.

[0022] Figure 3 Schematic diagram of the curved surface s structure according to an embodiment of the present invention.

[0023] Figure 4 Schematic diagram of the curved surface s on the steering knuckle model according to an embodiment of the present invention.

[0024] Figure 5 This is a schematic diagram showing the completion of installation of the first limiting structure and the second limiting structure according to an embodiment of the present invention.

[0025] Figure 6 Schematic diagram of the first limiting structure and the second limiting structure in the process of limiting contact according to an embodiment of the present invention.

[0026] Figure 7 This is a schematic diagram of extreme jump + steering in an embodiment of the present invention.

[0027] Among them: 1 is the upper control arm, 2 is the steering knuckle, 3 is the stabilizer rod, 4 is the stabilizer bar, 5 is the shock absorber, 6 is the steering rod, 7 is the lower control arm, 8 is the first limiting structure, 9 is the second limiting structure, p1 is the limiting point, l1 is the straight line drawn by the p1 limiting point in the horizontal plane parallel to the tire sidewall, l12 is the straight line drawn by the p12 limiting point in the horizontal plane parallel to the tire sidewall, and s is an irregular curved surface. DETAILED DESCRIPTION

[0028] The following describes embodiments of the present invention in detail, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the embodiments of the present invention, and should not be construed as limiting the present invention.

[0029] The present invention will be further described in detail with reference to the accompanying drawings.

[0030] In one embodiment of the present invention, a method for optimizing a limiting structure of an automobile steering knuckle includes the following steps:

[0031] Step 1. Create a double wishbone front suspension motion simulation analysis design in the software, substitute the steering rack travel and tire runout of the vehicle model, and obtain the complete front suspension motion simulation analysis design model of the vehicle model. Figure 1As shown, the front suspension dynamic motion model includes an upper arm 1, a steering knuckle 2, a stabilizer rod 3, a stabilizer bar 4, a shock absorber 5, a steering rod 6, and a lower arm 7. Specifically, the internal code of the vehicle model is JP360, the tire runout stroke is ±95mm, and the steering rack stroke is ±82.5mm. It is understandable that different vehicle models have different parameters, so the values of the steering rack stroke and the tire runout stroke are determined according to the vehicle model.

[0032] Step 2. Reference Figure 7 As shown, the front suspension motion simulation analysis and design model is subjected to full-condition motion simulation, and the minimum spacing between adjacent parts under all working conditions is respectively found, and the working conditions where the spacing between all parts is less than the safety requirement are found. Specifically, the adjacent parts include the tire and the lower arm 7, and the tire and the stabilizer bar 4. In this embodiment, two groups are listed, as shown in Table 1, where working condition 1 is the working condition where the spacing between parts is less than the safety requirement. It can be understood that the spacing between the tire and other suspension parts may also be included;

[0033] Step 3. For the working condition where the spacing between parts is less than the safety requirement, a first limiting structure 8 is first set on the lower arm. Specifically, the first limiting structure 8 includes a cylindrical structure and a hemispherical structure arranged at the outer end of the cylindrical structure;

[0034] Step 4. Obtain several limiting points and corresponding straight lines according to the first limiting structure 8;

[0035] Step 5. According to the limit point and the corresponding straight line,

[0036] Specifically, the steps of obtaining a plurality of limiting points and corresponding straight lines according to the first limiting structure 8 are as follows:

[0037] Step A. Specifically, in this vehicle model, the required limit jump stroke is divided into 12 parts, namely G1, G2, G3, G4, G5, G6, G7, G8, G9, G10, G11, and G12;

[0038] Step B. Simulate the working condition corresponding to G1 through dynamic motion model, refer to Figure 2 As shown, find the limiting point p1 on the steering knuckle corresponding to the first limiting structure 8, and draw a straight line l1 in the horizontal plane parallel to the tire sidewall through the limiting point p1;

[0039] Step C. Repeat step B. After all the working conditions of G1, G2, G3, G4, G5, G6, G7, G8, G9, G10, G11, and G12 are simulated, a series of limit points p1, p2, p3, p4, p5, p6, p7, p8, p9, p10, p11, and p12 and the corresponding straight lines l1, l2, l3, l4, l5, l6, l / 7, l8, l9, l10, l11, and l12 can be obtained.

[0040] Reference Figure 3-4 As shown, through the software bridging module, all adjacent straight lines are bridged in the order of l1, l2, l3, l4, l5, l6, l / 7, l8, l9, l10, l11, and l12 to obtain an irregular surface s;

[0041] Step 6. Reference Figure 5-Figure 6 As shown, the second limiting structure 9 is fixed on the steering knuckle according to the design of the curved surface s. The curved surface s is the contour surface of the second limiting structure 9. After the first limiting structure 8 and the second limiting structure 9 are installed, as shown in Table 1, the working condition 2 is the working condition where the spacing between the parts after limiting is greater than the safety requirement.

[0042] The beneficial effects of the present invention are: creating a front suspension motion simulation analysis and design in the form of a double wishbone in the software, substituting the steering rack stroke and tire bounce stroke of the vehicle model, and obtaining a complete front suspension motion simulation analysis and design model of the vehicle model, performing full-condition motion simulation on the front suspension motion simulation analysis and design model, and finding the specific value of the steering wheel angle limit required to ensure a safe distance between the suspension parts, and then designing a matching first limiting structure 8 and a second limiting structure 9 on the suspension lower arm 7 and the steering knuckle 2 respectively, and designing the second limiting structure 9 to be fixed to the steering knuckle 2 according to the curved surface s, and the curved surface s is the contour surface of the second limiting structure 9 on the steering knuckle, and the steering limit of the second limiting structure 9 is smooth, reducing abnormal steering noise, thereby better achieving the purpose of steering wheel angle limit.

[0043]

[0044] Table 1

[0045] Throughout this specification, reference to terms such as "one embodiment," "some embodiments," "examples," "specific examples," or "some examples" means that a specific feature, structure, material, or characteristic described in conjunction with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, schematic representations of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

[0046] The above-described embodiments merely illustrate several implementations of the present invention, and while their descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that a person skilled in the art would be able to make numerous variations and improvements without departing from the spirit of the present invention, all of which fall within the scope of protection of the present invention. Therefore, the scope of protection of the present invention shall be determined by the appended claims.

Claims

1. A method for optimizing a limiting structure of a steering knuckle of an automobile, characterized in that: The steps include: Step 1. Create a double-wishbone front suspension kinematic analysis design in the software. Substitute the vehicle's steering rack travel and tire runout to obtain a complete front suspension kinematic analysis design model. Step 2. Perform full-condition motion simulation on the front suspension motion simulation analysis and design model, find the minimum spacing between adjacent parts under all conditions, and identify the conditions where the spacing between all parts is less than the safety requirement. Step 3. For working conditions where the spacing between parts is less than the safety requirement, first set the first limit structure on the lower arm; Step 4. Obtain several limit points and corresponding straight lines according to the first limit structure; Step 5. Based on the limit points and the corresponding straight lines, all adjacent straight lines are bridged in sequence by a software bridging module to obtain an irregular curved surface s; Step 6. Fix the second limiting structure on the steering knuckle according to the curved surface s, where the curved surface s is the contour surface of the second limiting structure.

2. The optimization method for the limiting structure of the automobile steering knuckle according to claim 1, characterized in that: The steps of obtaining a plurality of limiting points and corresponding straight lines according to the first limiting structure are: Step A. Divide the required limit jump stroke into n equal parts, namely G1, G2, G3...Gn; Step B. Based on the working condition corresponding to G1, a motion simulation analysis is performed to find a limit point p1 on the steering knuckle corresponding to the first limit structure, and a straight line l1 is drawn through the limit point p1 in the horizontal plane and parallel to the tire sidewall; Step C. Repeat step B. When all working conditions of G1, G2, G3…Gn are simulated, a series of limit points p1, p2, p3…pn and corresponding straight lines l1, l2, l3…ln can be obtained.

3. The optimization method for the limiting structure of the automobile steering knuckle according to claim 1, characterized in that: The adjacent parts include tires and lower control arms, and tires and stabilizer bars.

4. The optimization method for the limiting structure of the automobile steering knuckle according to claim 1, characterized in that: The first limiting structure includes a cylindrical structure and a hemispherical structure arranged at the outer end of the cylindrical structure.

5. The optimization method for the limiting structure of the automobile steering knuckle according to claim 1, characterized in that: The software for creating the dynamic motion model of the double wishbone suspension system is CATIA software.

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