Pin hole wear life prediction calculation method

Abstract

The application provides a pin shaft hole wear life prediction calculation method, comprising the following steps: establishing a suspension assembly motion dynamics model through simulation software, performing suspension dynamics simulation analysis calculation, calculating and extracting the maximum radial force value between the suspension swing arm pin shaft and the mounting seat; analyzing the position of the pin shaft with the maximum stress, performing contact finite element analysis calculation on the suspension swing arm pin shaft and the mounting seat, calculating and extracting the maximum shear stress value of the mounting seat hole; calculating the anti-wear times of the suspension swing arm pin shaft and the mounting seat hole according to the IBM wear calculation method in the tribology principle; calculating the wear life of the suspension swing arm pin shaft and the mounting seat hole according to the suspension natural frequency and the working time length. The application discretizes the continuous wear process, converts the complex dynamic problem into a simple quasi-static problem, has the characteristics of short period, low cost and the like, and can be repeatedly performed, and can effectively shorten the research and development period and reduce the research and development cost.

Description

TECHNICAL FIELD

[0001] The application relates to a pin shaft hole wear life prediction calculation method and belongs to the technical field of wear life prediction calculation reliability. BACKGROUND

[0002] Due to the complexity and diversity of wear problems, traditional test research methods cannot well and timely solve and judge actual wear problems. Although the test method is closer to the actual situation, it needs to consume a large amount of manpower and material resources, and has a long research period and high cost. SUMMARY

[0003] The application aims to provide a pin shaft hole wear life prediction calculation method, which discretely processes the continuous wear process and converts a complex dynamic problem into a simple quasi-static problem, has the characteristics of short period, low cost and the like, can be repeatedly performed, and can effectively shorten the research and development period and reduce the research and development cost.

[0004] In order to achieve the above-mentioned purpose, the application is implemented through the following technical scheme.

[0005] A pin shaft hole wear life prediction calculation method comprises the following steps:

[0006] Step 1: first, a suspension assembly motion dynamics model is established through simulation software, suspension dynamics simulation analysis and calculation are performed, and the maximum radial force value between a suspension swing arm pin shaft and a mounting seat is extracted through post-processing calculation;

[0007] Step 2: a finite element analysis model of the suspension swing arm pin shaft and the mounting seat is established through finite element analysis software, the position of the pin shaft with the maximum stress is analyzed, the simplified model of the pin shaft and the mounting seat is taken as an analysis object, the maximum radial force value between the suspension swing arm pin shaft and the mounting seat is taken as an input load, contact finite element analysis and calculation are performed on the suspension swing arm pin shaft and the mounting seat, and the maximum shear stress value of the mounting seat hole is extracted;

[0008] Step 3: the maximum shear stress value of the mounting seat hole is taken as a fatigue life limit, and the number of times of wear resistance of the suspension swing arm pin shaft and the mounting seat hole is calculated according to the IBM wear calculation method in the tribology principle;

[0009] Step 4: the wear life of the suspension swing arm pin shaft and the mounting seat hole is calculated according to the suspension frequency deviation and the working time length.

[0010] Preferably, the maximum radial force value extracted through the post-processing calculation includes the maximum radial force of the upper swing arm pin shaft, the maximum radial force of the front pin shaft of the lower swing arm, and the maximum radial force of the rear pin shaft of the lower swing arm.

[0011] Preferably, the most stressed pin shaft in step 2 is considered in the finite element analysis of the simplified model of the mounting seat, and the friction torque is considered, and the friction coefficient is 0.15.

[0012] Preferably, the IBM wear calculation method in the tribological principle is used to calculate the anti-wear times of the suspension swing arm pin shaft and the mounting seat hole, and the calculation method is as follows:

[0013] 1) According to the relationship of the metal material fatigue curve, the relationship between the stroke times under the condition of guaranteeing zero wear and the maximum shear stress is established:

[0014]

[0015] In the formula, τ max is the maximum shear stress of the mounting seat, τ s is the shear yield limit of the material, and γ0 is the friction coefficient.

[0016] 2) According to the suspension natural frequency, the anti-wear times N r of the pin shaft mounting seat per day are calculated.

[0017] N r = 60*60*f*h

[0018] In the formula, f is the suspension natural frequency, and h is the working time per day.

[0019] Preferably, the wear life calculation specific steps are as follows:

[0020]

[0021] In the formula, D is the wear days.

[0022] A pin shaft hole wear life prediction simulation model, comprising a frame assembly, a swing arm mounting seat assembly, an upper swing arm, a lower swing arm, a thrust rod, an oil gas spring, and a wheel assembly, the swing arm mounting seat assembly is fixed on one side of the frame assembly, the swing arm mounting seat assembly is connected with the upper swing arm through the upper swing arm pin shaft, and is connected with the lower swing arm through the front pin shaft and the rear pin shaft of the lower swing arm, one end of the thrust rod is connected to the frame assembly, the other end is connected to the wheel assembly, and the oil gas spring is connected between the frame assembly and the lower swing arm in the vertical direction.

[0023] The present application has the advantages that: the present application discretizes the continuous wear process, converts the complex dynamic problem into a simple quasi-static problem, and has the characteristics of short cycle, low cost and the like compared with the traditional test method, and the wear life problem of the suspension swing arm pin shaft and the mounting seat hole is studied by using the numerical simulation technology and the IBM wear calculation method, and the present application can be repeatedly carried out, and the research and development cycle can be effectively shortened and the research and development cost can be reduced. BRIEF DESCRIPTION OF DRAWINGS

[0024] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used together with the embodiments of the invention to explain the invention and do not constitute a limitation thereof.

[0025] Figure 1 This is a simulation model of the kinematics of a double wishbone independent suspension.

[0026] Figure 2 This is a curve showing the relationship between the radial force at each pivot of a double wishbone independent suspension and the wheel runout.

[0027] In the diagram: 1. Frame assembly; 2. Control arm mount assembly; 3. Upper control arm; 4. Lower control arm; 5. Thrust rod; 6. Gas spring; 7. Upper control arm pin; 8. Lower control arm front pin; 9. Lower control arm rear pin; 10. Wheel assembly; 71. Relationship curve between radial force and wheel runout at the upper control arm pin; 81. Relationship curve between radial force and wheel runout at the lower control arm front pin; 91. Relationship curve between radial force and wheel runout at the lower control arm rear pin. Detailed Implementation

[0028] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0029] Example:

[0030] The invention will be described in conjunction with the accompanying drawings. The method for predicting the wear life of suspension control arm pin mounting holes first establishes a kinematic and dynamic simulation model of a double wishbone independent suspension, as shown in the accompanying drawings. Figure 1 As shown, a kinematic simulation analysis was conducted based on a single-axle design axle load of 10 tons. The relationship curves between the radial force at each pin of the suspension control arm and the wheel runout are as follows: Figure 2 As shown. Within the wheel travel range, the maximum radial force at point 7 of the upper control arm pin is 3.8 x 10. 4 N; The maximum radial force at 8 points on the lower control arm front pin is 0.04 x 10 N. 4 N; The maximum radial force at 9 points on the rear pivot of the lower control arm is 5.2 x 10 N. 4 N.

[0031] The kinematic analysis of the suspension system shows that the maximum force is experienced at the rear pin 9 of the lower control arm. Taking the simplified model 21 of the lower control arm rear pin 9 and the mounting base as the analysis object, the maximum radial force at the rear pin 9 of the lower control arm is 5.2 x 10⁻⁶. 4N is the input load. Finite element analysis was performed on the simplified model 21 of the lower control arm rear pin 9 and the mounting base, considering the effect of frictional torque (friction coefficient f = 0.15). The analysis results show that the maximum shear stress of the mounting base is 13 MPa.

[0032] Based on the IBM wear calculation method in tribology and referring to the relationship of fatigue curves for metallic materials, a formula is established to determine the relationship between the number of strokes and the maximum shear stress under the condition of zero wear:

[0033]

[0034] From ①, it can be seen that the fatigue life limit is τ max At that time, the number of lifetime travels N is:

[0035]

[0036] In the formula: τ max The maximum shear stress experienced by the mounting base is 13 MPa.

[0037] τ s The shear yield strength of the material is 189 MPa.

[0038] γ0 is the friction coefficient corresponding to a stroke count of 2000. The coefficient is 0.2 for dry friction and 1 for hydrodynamic friction. The friction form of this invention is dry friction, with a value of 0.2.

[0039] Substituting the above parameter values ​​into ②, we can see that the number of strokes in the service life N is 2.97 x 10^6. 7 .

[0040] The number of daily wear cycles (N) of the pin mounting seat is calculated based on the suspension misalignment frequency. r :

[0041] N r =60×60×f×h③

[0042] In the formula: f is the suspension offset frequency, which is 1.2Hz;

[0043] h represents the daily working hours, which is 4 hours.

[0044] Substituting into ③, we can see that the mounting bracket wears out N times per day. r The number is 17280.

[0045] Wear-out days calculation D:

[0046]

[0047] N, N rSubstitute into the formula ④, 4 hours a day, according to the calculation and analysis can be known, in the case of no wear and tear of the swing pin shaft and mounting seat, 4 hours a day can be sustained for 1719 days.

Claims

1. A method for predicting and calculating the wear life of a pin hole, characterized in that, Includes the following steps: Step 1: First, establish a motion dynamics model of the suspension assembly using simulation software, perform suspension dynamics simulation analysis and calculation, and extract the maximum radial force value between the suspension control arm pin and the mounting seat through post-processing calculation; Step 2: Establish a finite element analysis model of the suspension arm pin and mounting seat using finite element analysis software, analyze the pin position with the greatest force, take the simplified model of the pin and mounting seat as the analysis object, take the maximum radial force between the suspension arm pin and mounting seat as the input load, perform contact finite element analysis calculation on the suspension arm pin and mounting seat, and calculate and extract the maximum shear stress value of the mounting seat hole. Step 3: Using the maximum shear stress value of the mounting hole as the fatigue life limit, calculate the number of wear cycles between the suspension arm pin and the mounting hole according to the IBM wear calculation method in tribology. Step 4: Calculate the wear life of the suspension control arm pin and mounting hole based on the suspension bias frequency and working time; The IBM wear calculation method based on the tribological principle is used to calculate the number of wear cycles between the suspension control arm pin and the mounting hole as follows: 1) Referring to the fatigue curves of metallic materials, establish the relationship between the number of strokes and the maximum shear stress under the condition of zero wear: In the formula: The maximum shear stress experienced by the mounting base. The shear yield strength of the material. The coefficient of friction, 2) Calculate the daily wear frequency of the pin mounting bracket based on the suspension misalignment frequency. , = In the formula: f is the suspension bias frequency, and h is the daily working time; The specific steps for calculating the wear life are as follows: In the formula, D represents the number of days of wear and tear; The maximum radial force values ​​extracted by the post-processing calculation include the maximum radial force of the upper control arm pin, the maximum radial force of the lower control arm front pin, and the maximum radial force of the lower control arm rear pin.

2. The method for predicting and calculating the wear life of a pin hole according to claim 1, characterized in that, In step 2, frictional torque is added to the simplified model finite element analysis of the pin and mounting base subjected to the greatest force, with a friction coefficient of 0.

15.

3. A simulation model for predicting the wear life of a pin hole using any one of claims 1-2, characterized in that, The assembly includes a frame assembly (1), a swing arm mounting assembly (2), an upper swing arm (3), a lower swing arm (4), a thrust rod (5), a gas spring (6), and a wheel assembly (10). The swing arm mounting assembly (2) is fixed to one side of the frame assembly (1). The upper part of the swing arm mounting assembly (2) is connected to the upper swing arm (3) through the upper swing arm pin (7), and the lower swing arm (4) is connected through the lower swing arm front pin (8) and the lower swing arm rear pin (9). One end of the thrust rod (5) is connected to the frame assembly (1), and the other end is connected to the wheel assembly (10). The gas spring (6) is vertically connected between the frame assembly (1) and the lower swing arm (4).

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