Macpherson front overhang knuckle strength analysis method and device

Abstract

The invention discloses a Macpherson front overhang knuckle strength analysis method which comprises the following steps: establishing a Macpherson front overhang knuckle geometric model, the geometric model comprises a steering knuckle, a swing arm ball pin, a steering pull rod ball pin, a vibration reduction supporting column lower support, a hub bearing inner ring, a hub bearing locking nut, a brake caliper supporting frame, a vibration reduction supporting column simulation beam unit, a swing arm simulation beam unit, a steering pull rod simulation beam unit, a wheel simulation beam unit and a brake disc simulation beam unit. Performing grid division on each part of the Macpherson front overhang steering knuckle geometric model; establishing a connection relationship among the components of the Macpherson front overhang steering knuckle; establishing a whole vehicle coordinate system, and setting boundary conditions; applying load according to different working conditions; and performing finite element analysis. According to the Macpherson front overhang knuckle strength analysis method disclosed by the invention, the model is simplified, the modeling efficiency can be improved, the calculation and analysis time can be shortened, the working condition of a real vehicle can be better simulated, and the calculation precision is ensured.

Description

Technical Field

[0001] The present invention relates to the field of vehicle technology, and more specifically, to a method and device for analyzing the strength of a McPherson front suspension steering knuckle. Background Art

[0002] McPherson front suspension, full name McPherson independent front suspension system, is a front suspension design widely used in modern cars. It is mainly composed of three core components: coil spring, shock absorber (also called shock absorber strut) and A-shaped lower control arm (or swing arm). The coil spring is responsible for absorbing and alleviating the vibration from the road, while the shock absorber further suppresses the excessive bounce of the spring through the damping effect to ensure that the wheel maintains good contact with the ground. The A-shaped lower control arm not only supports the wheel, but also converts the up and down bounce of the wheel into the swing of the control arm, thereby effectively controlling the lateral displacement of the wheel and maintaining the handling stability of the vehicle. McPherson front suspension has become the preferred solution for the front suspension system of many models with its compact structure, sensitive response and relatively low manufacturing cost.

[0003] The steering knuckle is a key component in the McPherson independent front suspension system. It plays the role of a bridge connecting the wheel and the suspension system. In the McPherson front suspension, the upper end of the steering knuckle is connected to the lower end of the shock absorber strut, the other end is connected to the wheel hub, the lower end is connected to the swing arm, and the side end is connected to the steering rod. When the driver turns the steering wheel, the steering rod will drive the steering knuckle to rotate along the kingpin, thereby driving the wheel to turn. When the car is driving, the steering knuckle is subjected to variable impact loads, so it is required to have high safety. Under the action of these loads, the strength of the steering knuckle plays a very important role. Its failure will cause the car to lose its ability to turn flexibly, causing unpredictable loss of life and property. Therefore, the strength analysis of the steering knuckle is very important.

[0004] There are two existing methods for analyzing the strength of the steering knuckle: 1. Constructing a complete suspension analysis model of the McPherson independent front suspension system (including the stiffness data of the front and rear bushings of the swing arm, the stiffness data of the upper support assembly of the shock absorber strut, the stiffness data of the buffer block, the stiffness data of the coil spring, and all suspension parts). The operation is complex and time-consuming, the analysis and calculation time is long, it is prone to errors, and the efficiency is low; 2. Constructing an analysis model with only the steering knuckle, and simulating the beam unit of the steering knuckle and the wheel radius. This method cannot simulate the actual vehicle working conditions well, the analysis accuracy is poor, and the analysis results deviate greatly from the actual conditions.

[0005] Therefore, how to improve the efficiency of steering knuckle strength analysis and save calculation time has become a technical problem that needs to be solved urgently by technical personnel in this field. Summary of the invention

[0006] In view of this, the object of the present invention is to provide a McPherson front suspension steering knuckle strength analysis method to improve the efficiency of steering knuckle strength analysis and save calculation time.

[0007] Another core of the present invention is to disclose a MacPherson front suspension steering knuckle strength analysis device.

[0008] To achieve the above object, the present invention provides the following technical solutions:

[0009] A strength analysis method for a McPherson front suspension steering knuckle, comprising:

[0010] Establish the geometric model of the McPherson front suspension steering knuckle, which includes the steering knuckle, swing arm ball pin, steering tie rod ball pin, shock absorber strut lower bracket, wheel hub bearing inner ring, wheel hub bearing locking nut, brake caliper support frame, shock absorber strut simulation beam unit, swing arm simulation beam unit, steering tie rod simulation beam unit, wheel simulation beam unit and brake disc simulation beam unit;

[0011] Mesh the components of the MacPherson front suspension steering knuckle geometry model;

[0012] Establish the connection relationship between the various components of the McPherson front suspension steering knuckle;

[0013] Establish the vehicle coordinate system and set boundary conditions;

[0014] Apply loads according to different working conditions;

[0015] Perform finite element analysis.

[0016] Optionally, in the above-mentioned McPherson front suspension steering knuckle strength analysis method, the step of establishing the McPherson front suspension steering knuckle geometric model includes: importing the part models and suspension hard point coordinates of the steering knuckle, the swing arm ball pin, the steering tie rod ball pin, the shock absorber strut lower bracket, the wheel hub bearing inner ring, the wheel hub bearing locking nut and the brake caliper support frame;

[0017] The vibration-damping strut simulation beam unit, the swing arm simulation beam unit, the pull rod simulation beam unit, the wheel simulation beam unit and the brake disc simulation beam unit are respectively established through the suspension hard point coordinates and various parts.

[0018] Optionally, in the above-mentioned McPherson front suspension steering knuckle strength analysis method, the suspension hard point coordinates include: the coordinates of the upper end point of the shock absorber strut, the coordinates of the front point of the swing arm simulation beam unit, the coordinates of the rear point of the swing arm simulation beam unit, the coordinates of the inner point of the steering rod, the coordinates of the wheel center point and the coordinates of the wheel contact point.

[0019] Optionally, in the above-mentioned McPherson front suspension steering knuckle strength analysis method, the vibration-damping strut simulation beam unit is established by the upper end point of the vibration-damping strut and the center point of the inner cylindrical surface of the lower bracket of the vibration-damping strut;

[0020] The swing arm simulation beam unit is established through the front point of the swing arm simulation beam unit, the rear point of the swing arm simulation beam unit and the center point of the swing arm ball pin;

[0021] The steering tie rod simulation beam unit is established through the inner point of the steering tie rod and the center point of the steering tie rod ball pin;

[0022] The wheel simulation beam unit is established through the wheel center point and the wheel grounding point;

[0023] The brake disc simulated beam unit is established by the center point of the first brake pad mounting groove, the center point of the second brake pad mounting groove and the center point of the wheel.

[0024] Optionally, in the above-mentioned McPherson front suspension steering knuckle strength analysis method, in the step of establishing the connection relationship between the components of the McPherson front suspension steering knuckle, the lower bracket of the shock absorbing strut is bound and connected to the steering knuckle;

[0025] The ball pin of the steering tie rod is bound and connected to the steering knuckle;

[0026] The inner ring of the wheel hub bearing is in contact with the bearing mounting pin of the steering knuckle;

[0027] The wheel hub bearing locking nut is bound to the steering knuckle and the inner ring of the wheel hub bearing and a nut locking torque is applied;

[0028] The brake caliper support frame is bound and connected to the steering knuckle.

[0029] Optionally, in the above-mentioned McPherson front suspension steering knuckle strength analysis method, in the steps of establishing the vehicle coordinate system and setting the boundary conditions,

[0030] The first degree of freedom, the second degree of freedom and the third degree of freedom of the upper end of the vibration-damping support simulation beam unit are constrained, and the lower end of the vibration-damping support simulation beam unit is fixedly connected to the vibration-damping support lower bracket;

[0031] The first degree of freedom, the second degree of freedom and the third degree of freedom are constrained at the front point of the swing arm simulation beam unit and the rear point of the swing arm simulation beam unit; the outer point of the swing arm simulation beam unit is connected to the swing arm ball pin to constrain the first degree of freedom, the second degree of freedom and the third degree of freedom;

[0032] The first end of the steering tie rod simulation beam unit is connected to the steering tie rod ball pin to constrain the first degree of freedom, the second degree of freedom and the third degree of freedom, and the first degree of freedom, the second degree of freedom, the third degree of freedom and the fifth degree of freedom of the second end of the steering tie rod simulation beam unit are constrained;

[0033] Connecting the wheel simulation beam unit to the inner ring of the hub bearing, constraining the first degree of freedom, the second degree of freedom, the third degree of freedom, the fourth degree of freedom and the sixth degree of freedom;

[0034] The brake disc simulation beam unit is connected to the brake caliper support frame;

[0035] The wheel simulation beam unit is fixedly connected to the brake disc simulation beam unit.

[0036] Optionally, in the above-mentioned McPherson front suspension steering knuckle strength analysis method, in the step of connecting the brake disc simulation beam unit and the brake caliper support frame,

[0037] When a load of a forward braking condition is applied, the brake disc simulation beam unit is fixedly connected to the first brake pad mounting groove of the brake caliper support frame;

[0038] When a load of a reverse braking condition is applied, the brake disc simulation beam unit is fixedly connected to the second brake pad mounting groove of the brake caliper support frame;

[0039] When non-braking loads are applied, the brake disc simulation beam element and the brake caliper support frame are not constrained.

[0040] Optionally, in the above-mentioned McPherson front suspension steering knuckle strength analysis method, in the step of applying a load to a tire contact point according to different working conditions, the load is applied to the wheel contact point.

[0041] Optionally, in the above-mentioned McPherson front suspension steering knuckle strength analysis method, before the step of establishing a whole vehicle coordinate system and constraining the degrees of freedom of each component of the McPherson front suspension steering knuckle, the method further includes the step of defining material properties of each component of the McPherson front suspension steering knuckle.

[0042] A MacPherson front suspension steering knuckle strength analysis device, comprising:

[0043] Meshing unit, used to mesh the geometry model of the MacPherson front suspension steering knuckle;

[0044] A connection relationship unit is used to establish the connection relationship between various components in the McPherson front suspension steering geometry model;

[0045] The freedom constraint unit is used to constrain the freedom of each component in the McPherson front suspension steering geometry model;

[0046] Analyze the unit, perform finite element analysis, and read the analysis results.

[0047] It can be seen from the above scheme that the McPherson front suspension steering knuckle strength analysis method disclosed in the present invention uses a shock-absorbing strut simulation beam unit to simulate a shock-absorbing strut, a swing arm simulation beam unit to simulate a swing arm, a steering rod simulation beam unit to simulate a steering rod, a wheel simulation beam unit to simulate a wheel, and a brake disc simulation beam unit to simulate a brake disc. Compared with the prior art that constructs a complete McPherson independent front suspension system suspension analysis model, the model is simplified, the modeling efficiency can be improved, and the calculation and analysis time can be shortened; at the same time, the constraint mode of the front point of the swing arm simulation beam unit, the rear point of the swing arm simulation beam unit and the upper end point of the shock-absorbing strut is simplified from the actual six-degree-of-freedom constraint to a three-degree-of-freedom constraint (only the first degree of freedom, the second degree of freedom and the third degree of freedom are constrained), the model is simplified, the steering knuckle strength analysis efficiency can be further improved, the research and development cycle can be shortened, and the steering knuckle strength analysis efficiency can be improved; compared with the prior art that only constructs an analysis model of the steering knuckle, the actual vehicle working condition can be better simulated to ensure the calculation accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. 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 creative work.

[0049] Figure 1 The structure of the McPherson front suspension steering knuckle model disclosed in the embodiment of the present invention is shown in FIG. Figure 1 ;

[0050] Figure 2 The structure of the McPherson front suspension steering knuckle model disclosed in the embodiment of the present invention is shown in FIG. Figure 2 ;

[0051] Figure 3 A diagram showing the connection relationship between the components of the McPherson front suspension steering knuckle disclosed in an embodiment of the present invention;

[0052] Figure 4 It is a schematic diagram of assembling the steering knuckle, the wheel hub bearing locking nut and the wheel hub bearing inner ring disclosed in an embodiment of the present invention;

[0053] Figure 5 The present invention is a flowchart of a method for analyzing the strength of a McPherson front suspension steering knuckle disclosed in an embodiment of the present invention.

[0054] Among them, 1 is a steering knuckle, 2 is a swing arm ball pin, 21 is a center point of a swing arm ball pin, 3 is a steering tie rod ball pin, 31 is a center point of a steering tie rod ball pin, 4 is a lower bracket of a shock absorber strut, 41 is a center point of an inner cylindrical surface of the lower bracket of a shock absorber strut, 5 is an inner ring of a wheel hub bearing, 6 is a wheel hub bearing locking nut, 7 is a brake caliper support frame, 71 is a first brake pad mounting groove, 711 is a center point of a first brake pad mounting groove, 72 is a second brake pad mounting groove, 721 is a center point of a second brake pad mounting groove, 8 is a shock absorber strut simulated beam unit, 81 is an upper end point of a shock absorber strut, 9 is a swing arm simulated beam unit, 91 is a front point of a swing arm simulated beam unit, 92 is a rear point of a swing arm simulated beam unit, 93 is an outer point of a rear point of a swing arm simulated beam unit, 10 is a steering tie rod simulated beam unit, 101 is an inner point of a steering tie rod, 11 is a wheel simulated beam unit, 111 is a wheel grounding point, 112 is a wheel center point, and 12 is a brake disc simulated beam unit. DETAILED DESCRIPTION

[0055] The core of the invention is to disclose a McPherson front suspension steering knuckle strength analysis method, which improves the efficiency of steering knuckle strength analysis and saves calculation time.

[0056] Another core of the present invention is to disclose a MacPherson front suspension steering knuckle strength analysis device.

[0057] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0058] like Figure 5 As shown, the embodiment of the present invention discloses a method for analyzing the strength of a McPherson front suspension steering knuckle, comprising the following steps:

[0059] S10, establishing a geometric model of the MacPherson front suspension steering knuckle;

[0060] Specifically, the geometric model of the McPherson front suspension steering knuckle includes a steering knuckle 1, a swing arm ball pin 2, a steering tie rod ball pin 3, a shock absorber strut lower bracket 4, a wheel hub bearing inner ring 5, a wheel hub bearing locking nut 6, a brake caliper support frame 7, a shock absorber strut simulation beam unit 8, a swing arm simulation beam unit 9, a steering tie rod simulation beam unit 10, a wheel simulation beam unit 11 and a brake disc simulation beam unit 12, as shown in FIG. Figure 1 and Figure 2 The shock-absorbing strut simulation beam unit 8 is used to simulate the shock-absorbing strut, the swing arm simulation beam unit 9 is used to simulate the swing arm, the steering rod simulation beam unit 10 is used to simulate the steering rod, the wheel simulation beam unit 11 is used to simulate the wheel, and the brake disc simulation beam unit 12 is used to simulate the brake disc.

[0061] Specifically, first import the part models and suspension hard point coordinates of the steering knuckle 1, the swing arm ball pin 2, the steering rod ball pin 3, the shock absorber strut lower bracket 4, the hub bearing inner ring 5, the hub bearing locking nut 6 and the brake caliper support frame 7. The suspension hard point coordinates specifically include the coordinates of the upper end point 81 of the shock absorber strut, the coordinates of the front point 91 of the swing arm simulation beam unit, the coordinates of the rear point 92 of the swing arm simulation beam unit, the coordinates of the inner point 101 of the steering rod, the coordinates of the wheel center point 112 and the coordinates of the wheel ground contact point 111.

[0062] The shock absorber strut simulation beam unit 8 is established through the shock absorber strut upper end point 81 and the center point 41 of the inner cylindrical surface of the shock absorber strut lower bracket, the swing arm simulation beam unit 9 is established through the swing arm simulation beam unit front point 91, the swing arm simulation beam unit rear point 92 and the swing arm ball pin center point 21, the steering rod simulation beam unit 10 is established through the steering rod inner point 101 and the steering rod ball pin center point 31, the wheel simulation beam unit 11 is established through the wheel center point 112 and the wheel grounding point 111, the brake disc simulation beam unit 12 is established through the first brake pad installation groove center point 711, the second brake pad installation groove center point 721 and the wheel center point 112, forming a T-shape, as shown in detail. Figure 1 shown.

[0063] S20. Mesh the components of the McPherson front suspension steering knuckle geometric model.

[0064] S30, establishing a connection relationship between various components of the McPherson front suspension steering knuckle;

[0065] Specifically, the lower bracket 4 of the damping strut is bound and connected to the steering knuckle 1, the steering tie rod ball pin 3 is bound and connected to the steering knuckle 1, the inner ring of the wheel hub bearing 5 is in contact with the bearing mounting pin of the steering knuckle 1, the wheel hub bearing locking nut 6 is bound and connected to the steering knuckle 1 and the inner ring of the wheel hub bearing 5 and the nut locking torque is applied, and the brake caliper support frame 7 is bound and connected to the steering knuckle 1. Figure 4 It should be noted that the binding connection here refers to two parts being connected together and both can be deformed at the same time.

[0066] S30', define the material properties of each component of the McPherson front suspension steering knuckle.

[0067] S40, establishing a vehicle coordinate system and setting boundary conditions;

[0068] First, establish the vehicle coordinate system, such as Figure 3 As shown, along the length direction of the vehicle, the direction toward the rear of the vehicle is the X-axis direction; along the width direction of the vehicle, facing the front of the vehicle, the right side of the vehicle is the Y-axis direction; along the height direction of the vehicle, the roof of the vehicle is the Z-axis direction.

[0069] It should be noted that the first degree of freedom refers to the linear movement along the X-axis (indicated by 1), the second degree of freedom refers to the linear movement along the Y-axis (indicated by 2), the third degree of freedom refers to the linear movement along the Z-axis (indicated by 3), the fourth degree of freedom refers to the rotation around the X-axis (indicated by 4), the fifth degree of freedom refers to the rotation around the Y-axis (indicated by 5), and the sixth degree of freedom refers to the degree of freedom around the Z-axis (indicated by 6).

[0070] The first degree of freedom, the second degree of freedom and the third degree of freedom of the upper end of the vibration-damping strut simulation beam element 8 are constrained ( Figure 3 123 is shown as fixed), the lower end of the vibration-damping strut simulation beam unit 8 is fixedly connected to the vibration-damping strut lower bracket 4 ( Figure 3 123456 constraint connections are shown in FIG); constraining the first degree of freedom, the second degree of freedom, and the third degree of freedom of the front point 91 of the swing arm simulation beam unit and the rear point 92 of the swing arm simulation beam unit ( Figure 3 123 is shown as fixed); the first end of the steering rod simulation beam unit 10 is connected to the steering rod ball pin 3, constraining the first degree of freedom, the second degree of freedom and the third degree of freedom ( Figure 3 123 constraint connection), constraining the first degree of freedom, the second degree of freedom, the third degree of freedom and the fifth degree of freedom of the second end of the steering tie rod simulation beam unit 10 ( Figure 3 1235 is shown as fixed); the wheel simulation beam unit 11 is connected to the inner ring of the wheel hub bearing, and the first degree of freedom, the second degree of freedom, the third degree of freedom, the fourth degree of freedom and the sixth degree of freedom are constrained (12346 constraint connection); the brake disc simulation beam unit 12 is connected to the brake caliper support frame 7; the wheel simulation beam unit 11 is fixedly connected to the brake disc simulation beam unit 12 (123456 constraint connection), and the constraint relationship between the components is as follows Figure 3 shown.

[0071] Among them, the connection between the brake disc simulation beam unit 12 and the brake caliper support frame 7 needs to be determined according to different working conditions. Specifically, when the load of the forward braking working condition is applied, the braking direction is along the +X axis direction, that is, the working condition contains the braking situation of the vehicle moving forward and stepping on the brake, the brake disc simulation beam unit 12 is fixedly connected to the first brake pad mounting groove 71 of the brake caliper support frame 7 (specifically 123456 connection constraints), that is, at this time, the first brake pad mounting groove 71 cooperates with the brake disc simulation beam unit 12 to generate braking force; when the load of the backward braking working condition is applied, the braking direction is along the -X axis direction, that is, the working condition contains the braking situation of the vehicle moving backward and stepping on the brake, the brake disc simulation beam unit 12 is fixedly connected to the second brake pad mounting groove 72 of the brake caliper support frame 7 (specifically 123456 connection constraints), that is, at this time, the second brake pad mounting groove 72 cooperates with the brake disc simulation beam unit 12 to generate braking force; when the load of the non-braking working condition is applied, that is, when there is no braking, the brake disc simulation beam unit 12 and the brake caliper support frame 7 are not constrained.

[0072] S50, applying a load at the wheel contact point 111 according to different working conditions;

[0073] Specifically, the load is applied to the wheel grounding point 111, and the vehicle operating conditions include forward braking conditions, forward emergency braking conditions, forward steering braking conditions (right turn), forward limit steering and deep pit conditions. In the above conditions, the brake disc simulation beam unit 12 is connected and constrained with the first brake pad mounting groove 71 in 12346; the vehicle operating conditions also include backward braking conditions and backward emergency braking conditions. In the above conditions, the brake disc simulation beam unit 12 is connected and constrained with the second brake pad mounting groove 72 in 12346; the vehicle operating conditions also include passing through double-sided convex humps conditions, passing through single-sided convex humps conditions (left side), passing through single-sided deep pit conditions (left side), limit steering conditions (right turn), steering drive conditions (right turn), and diagonal twisting conditions (left side). In the above conditions, the brake disc simulation beam unit 12 is not constrained with the second brake pad mounting groove 72.

[0074] S60, perform finite element analysis;

[0075] Specifically, the material properties of each component of the McPherson front suspension steering knuckle are defined, and finite element analysis and calculation are performed.

[0076] The inventor used this model and a complete McPherson independent front suspension system suspension analysis model to simulate and compare the strength of the steering knuckle and found that the calculation result deviation was less than 5%, but the time was saved by 70%-80%.

[0077] In summary, the McPherson front suspension steering knuckle strength analysis method disclosed in the embodiment of the present invention uses the shock absorber strut simulation beam unit 8 to simulate the shock absorber strut, the swing arm simulation beam unit 9 to simulate the swing arm, the steering rod simulation beam unit 10 to simulate the steering rod, the wheel simulation beam unit 11 to simulate the wheel, and the brake disc simulation beam unit 12 to simulate the brake disc. Compared with the prior art that constructs a complete McPherson independent front suspension system suspension analysis model, the model is simplified, which can improve the modeling efficiency and shorten the calculation and analysis time; at the same time, the constraint mode of the swing arm simulation beam unit front point 91, the swing arm simulation beam unit rear point 92 and the shock absorber strut upper end point 81 is simplified from the actual six degrees of freedom constraint to three degrees of freedom constraint (only constraining the first degree of freedom, the second degree of freedom and the third degree of freedom), which simplifies the model, can further improve the steering knuckle strength analysis efficiency, can shorten the research and development cycle, and improve the steering knuckle strength analysis efficiency; compared with the prior art that only constructs the analysis model of the steering knuckle, it can better simulate the actual vehicle working condition and ensure the calculation accuracy.

[0078] In addition, an embodiment of the present invention further discloses a McPherson front suspension steering knuckle strength analysis device, which includes a grid division unit, a connection relationship unit, a degree of freedom constraint unit and an analysis unit.

[0079] The mesh division unit is used to mesh the McPherson front suspension steering knuckle model; the connection relationship unit is used to establish the connection relationship between the components in the McPherson front suspension steering knuckle model; the degree of freedom constraint unit is used to constrain the degrees of freedom of each component in the McPherson front suspension steering knuckle model; and the analysis unit is used to perform finite element analysis and read the analysis results.

[0080] It should be noted that the various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the various embodiments can be referenced to each other.

[0081] In the following, the terms "first" and "second" are used for descriptive purposes only and are not to be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features.

[0082] The principles and implementation methods of the present invention are described in this article using specific examples. The description of the above embodiments is only used to help understand the core idea of ​​the present invention. It should be pointed out that for ordinary technicians in this technical field, without departing from the principles of the present invention, the present invention can also be improved and modified, and these improvements and modifications also fall within the scope of protection of the claims of the present invention.

Claims

1. A strength analysis method for a McPherson front suspension steering knuckle, characterized in that: include: Establishing a geometric model of a McPherson front suspension steering knuckle, the geometric model comprising a steering knuckle (1), a swing arm ball pin (2), a steering tie rod ball pin (3), a shock absorber strut lower bracket (4), a wheel hub bearing inner ring (5), a wheel hub bearing locking nut (6), a brake caliper support frame (7), a shock absorber strut simulation beam unit (8), a swing arm simulation beam unit (9), a steering tie rod simulation beam unit (10), a wheel simulation beam unit (11) and a brake disc simulation beam unit (12); Meshing each component of the McPherson front suspension steering knuckle geometric model; Establishing a connection relationship between the components of the McPherson front suspension steering knuckle; Establish the vehicle coordinate system and set boundary conditions; Apply loads according to different working conditions; Perform finite element analysis.

2. The McPherson front suspension steering knuckle strength analysis method according to claim 1, characterized in that: The step of establishing a MacPherson front suspension steering knuckle geometric model comprises: importing the part models and suspension hard point coordinates of the steering knuckle (1), the swing arm ball pin (2), the steering tie rod ball pin (3), the shock absorber strut lower bracket (4), the wheel hub bearing inner ring (5), the wheel hub bearing locking nut (6) and the brake caliper support frame (7); The vibration-damping strut simulation beam unit (8), the swing arm simulation beam unit (9), the pull rod simulation beam unit, the wheel simulation beam unit (11) and the brake disc simulation beam unit (12) are respectively established through the suspension hard point coordinates and various parts.

3. The McPherson front suspension steering knuckle strength analysis method according to claim 2, characterized in that: The suspension hard point coordinates include: the coordinates of the upper end point (81) of the shock absorbing strut, the coordinates of the front point (91) of the swing arm simulation beam unit, the coordinates of the rear point (92) of the swing arm simulation beam unit, the coordinates of the inner point (101) of the steering rod, the coordinates of the wheel center point (112) and the coordinates of the wheel ground contact point (111).

4. The McPherson front suspension steering knuckle strength analysis method according to claim 3, characterized in that: The vibration-damping strut simulated beam unit (8) is established by the upper end point (81) of the vibration-damping strut and the center point (41) of the inner cylindrical surface of the lower bracket of the vibration-damping strut; The swing arm simulation beam unit (9) is established through a swing arm simulation beam unit front point (91), a swing arm simulation beam unit rear point (92) and a center point of the swing arm ball pin (2); The steering tie rod simulation beam unit (10) is established through the steering tie rod inner point (101) and the center point of the steering tie rod ball pin (3); The wheel simulation beam unit (11) is established through the wheel center point (112) and the wheel ground contact point (111); The brake disc simulated beam unit (12) is established by the center point of the first brake pad installation groove (711), the center point of the second brake pad installation groove (712) and the wheel center point (112).

5. The McPherson front suspension steering knuckle strength analysis method according to claim 2, characterized in that: In the step of establishing the connection relationship between the components of the McPherson front suspension steering knuckle, the shock absorbing strut lower bracket (4) is bound and connected to the steering knuckle (1); The steering tie rod ball pin (3) is bound and connected to the steering knuckle (1); The wheel hub bearing inner ring (5) is in contact with and connected to the bearing mounting pin of the steering knuckle (1); The wheel hub bearing locking nut (6) is boundly connected to the steering knuckle (1) and the wheel hub bearing inner ring (5) and a nut locking torque is applied; The brake caliper support frame (7) is bound and connected to the steering knuckle (1).

6. The McPherson front suspension steering knuckle strength analysis method according to claim 5, characterized in that: In the steps of establishing the vehicle coordinate system and setting boundary conditions, The first degree of freedom, the second degree of freedom and the third degree of freedom of the upper end of the vibration-damping strut simulation beam unit (8) are constrained, and the lower end of the vibration-damping strut simulation beam unit (8) is fixedly connected to the vibration-damping strut lower bracket (4); The first degree of freedom, the second degree of freedom and the third degree of freedom of the front point (91) of the swing arm simulation beam unit and the rear point (92) of the swing arm simulation beam unit are constrained; the outer point of the swing arm simulation beam unit is connected to the swing arm ball pin (2) to constrain the first degree of freedom, the second degree of freedom and the third degree of freedom; The first end of the steering rod simulation beam unit (10) is connected to the steering rod ball pin (3) to constrain the first degree of freedom, the second degree of freedom and the third degree of freedom, and the first degree of freedom, the second degree of freedom, the third degree of freedom and the fifth degree of freedom of the second end of the steering rod simulation beam unit (10); Connecting the wheel simulation beam unit (11) to the wheel hub bearing inner ring (5) to constrain the first degree of freedom, the second degree of freedom, the third degree of freedom, the fourth degree of freedom and the sixth degree of freedom; The brake disc simulation beam unit (12) is connected to the brake caliper support frame (7); The wheel simulation beam unit (11) is fixedly connected to the brake disc simulation beam unit (12).

7. The McPherson front suspension steering knuckle strength analysis method according to claim 6, characterized in that: In the step of connecting the brake disc simulation beam unit (12) to the brake caliper support frame (7), When a load of a forward braking condition is applied, the brake disc simulation beam unit (12) is fixedly connected to the first brake pad mounting groove (71) of the brake caliper support frame (7); When a load of a reverse braking condition is applied, the brake disc simulation beam unit (12) is fixedly connected to the second brake pad mounting groove (72) of the brake caliper support frame (7); When a load in a non-braking condition is applied, the brake disc simulation beam unit (12) and the brake caliper support frame (7) are not constrained.

8. The McPherson front suspension steering knuckle strength analysis method according to claim 1, characterized in that: In the step of applying a load to the tire contact point according to different working conditions, the load is applied to the wheel contact point (111).

9. The McPherson front suspension steering knuckle strength analysis method according to claim 1, characterized in that: Before the step of establishing the whole vehicle coordinate system and constraining the degrees of freedom of each component of the McPherson front suspension steering knuckle, the method further includes the step of defining the material properties of each component of the McPherson front suspension steering knuckle.

10. A MacPherson front suspension steering knuckle strength analysis device, characterized in that: include: A meshing unit, used for meshing the geometric model of the McPherson front suspension steering knuckle; A connection relationship unit, used to establish the connection relationship between the components in the McPherson front suspension steering geometry model; A degree of freedom constraint unit, used for constraining the degree of freedom of each component in the McPherson front suspension steering geometry model; Analyze the unit, perform finite element analysis, and read the analysis results.

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