Design method for automotive ball joint, automotive ball joint, and automotive ball joint assembly

Abstract

The application relates to the technical field of ball hinge structure design, and discloses a design method of an automobile ball hinge, which comprises the following steps: simulating the maximum load of the automobile ball hinge through software; obtaining the minimum ball head diameter D' according to a formula 球头 ; building an assembly digital model of an automobile suspension system through software to obtain the minimum swing angle beta' of the automobile ball hinge; obtaining the minimum chord length L' according to the formula L' 弦长 =D' 球头 *sin beta', that is, obtaining the minimum chord length L' 弦长 ; obtaining sigma' j ' according to the formula and the strength calculation formula in step 2, carrying out optimization design on the minimum ball head diameter D' 球头 , and obtaining the optimal ball head diameter D 球头 . By using the design method, the maximum load and the strength of the automobile ball hinge can be considered in the early stage of design of the automobile ball hinge, the ball head diameter can be accurately designed, and problems such as fracture and abnormal wear after sale can be effectively avoided.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of spherical hinge structure design, and particularly relates to a design method of a vehicle spherical hinge, a vehicle spherical hinge and a vehicle spherical hinge assembly. BACKGROUND

[0002] The spherical hinge assembly in the vehicle suspension system is used for connecting the control arm and the steering knuckle, has the characteristics of restricting the translational freedom and releasing the rotational freedom, bears the weight of the whole vehicle and transmits the torque, simultaneously meets the wheel steering space and realizes the steering effect through the spherical hinge structure, is mainly composed of a spherical hinge, a spherical bowl seat and a spherical hinge sleeve, and the spherical hinge is a main force receiving component. The spherical hinge mainly comprises a spherical head, a spherical neck and a spherical pin, the spherical head and the spherical pin are connected by the spherical neck, the spherical head and the inner spherical surface of the spherical bowl seat form a spherical surface friction pair of the spherical hinge assembly, and the spherical pin is connected with the brake steering knuckle.

[0003] Since the working environment of the vehicle chassis suspension system is harsh, the spherical hinge bears the tensile and compressive load for a long time, the strength requirement is high, the spherical surface friction pair of the spherical hinge moves and wears under the action of the compressive force, the rigidity requirement is also high, and therefore the spherical hinge design needs to meet the reliability requirement for long-term use. At present, the design and development of the spherical hinge mainly concentrates on the experience design, that is, a design scheme is finally determined by analyzing and optimizing a large amount of test data, which increases the development cycle and cost and reduces the development efficiency. SUMMARY

[0004] Therefore, the present application provides a design method of a vehicle spherical hinge, a vehicle spherical hinge and a vehicle spherical hinge assembly to solve the problems that the spherical hinge design needs to meet the reliability requirement for long-term use and improve the development efficiency.

[0005] In a first aspect, the present application provides a design method of a vehicle spherical hinge, the vehicle spherical hinge comprising a spherical head, a spherical neck and a spherical pin, and the design method comprising:

[0006] Step 1: simulating the maximum load of the vehicle spherical hinge by software and decomposing the maximum radial force F1max and the maximum axial force F2max borne by the vehicle spherical hinge;

[0007] Step 2: calculating the minimum spherical head diameter D' according to the strength calculation formula Wherein σ j ≤ 25-30 MPa, and the projection area formula S j of the spherical head on the plane perpendicular to the maximum radial force F1max is 球头 2 球头 ;

[0008] Step 3: building an assembly numerical model of the vehicle suspension system by software and obtaining the minimum swing angle β' of the vehicle spherical hinge through simulation analysis.​

[0009] Step 4, according to formula L′ 弦长 =D′ 球头 By applying sinβ′, the minimum chord length L′ can be obtained. 弦长 ;

[0010] Step 5, according to the formula The strength calculation formula in step 2 yields σ. j If σ j 'Does not satisfy σ j If the pressure is ≤25~30MPa, then the minimum diameter of the ball head D′ should be... 球头 Optimize the design by incrementing the step size, repeating steps 4 and 5 until σ is achieved. j ′ Satisfies σ j If the pressure is ≤25~30MPa, then the corresponding ball head diameter D′ 球头 This is the optimal diameter D of the ball head. 球头 .

[0011] The maximum load on a car ball joint is simulated using software, and the minimum ball head diameter is calculated using the strength formula. Then, the minimum swing angle of the car ball joint is obtained through software modeling and simulation analysis. From the minimum swing angle and the minimum ball head diameter, the minimum chord length can be calculated. From this chord length, the projected area S of the ball head on the plane perpendicular to the maximum radial force F1max can be calculated. j ′, and the strength calculation formula can be used to calculate the projected area S again. j The corresponding strength σ' j The minimum ball head diameter is then optimized using a certain step size increment until σ is achieved. j By meeting the strength requirements, the optimal ball joint diameter can be obtained. That is, by adopting the design method of this invention, the maximum load and strength of the automotive ball joint can be considered in the early stage of automotive ball joint design, so that the ball joint diameter can be accurately designed, effectively avoiding problems such as breakage and abnormal wear after sales, improving development efficiency, and reducing development cycle and cost.

[0012] In one alternative implementation, the design method includes:

[0013] Step 6: Perform CAE pull-out force verification on the automotive ball joint according to the design pull-out force value ≥ 10 * maximum single-wheel full load, using L′ 弦长 By performing optimization design with a certain step size increment, the optimal chord length L is obtained. 弦长 The optimal swing angle β is then obtained by revising the calculation, where the maximum single-wheel full load is the design input given by the whole vehicle.

[0014] By CAE pull-out force checking of the automobile ball hinge, the problem of pull-out failure of the automobile ball hinge during movement can be prevented, and the design of the automobile ball hinge is more in line with actual needs.

[0015] In an alternative embodiment, the ball pin comprises a tapered rod comprising a large end and a small end, the large end being disposed proximate the ball head, and the design method comprises:

[0016] Step 7, according to the bending strength formula wherein M max =F 1max ·n s ·L, and σ s is the yield limit of the material of the automobile ball hinge, n s is a safety factor, L is the length from the ball center of the ball head to the large end of the tapered rod, and L≤D 球头 , and D 大端 is the diameter of the large end.

[0017] Since the automobile ball hinge can be simplified as a cantilever beam structure subjected to concentrated alternating load, the ball center of the ball head to the installation position of the tapered rod of the ball pin, i.e. the length of the force arm L, the shear force is constant on the cross section at any position of the length, and the bending moment is proportional to the force arm L, so the bending strength requirement of the large end of the ball pin is higher. By considering the bending strength factor in the design stage of the diameter of the large end of the tapered rod of the ball pin, the size of the ball pin calculated by the design can be more suitable for the bending strength in actual use, avoiding the problem of subsequent fracture.

[0018] In an alternative embodiment, n s =1.5; and / or, L=D 球头 ; and / or, the material of the automobile ball hinge is 40Cr steel or 42CrMo alloy structural steel.

[0019] In an alternative embodiment, the ball pin comprises a straight section rod and a limiting table, one end of the straight section rod is connected with the large end, the other end is connected with one end of the limiting table, the other end of the limiting table is disposed proximate the ball neck, and the design method comprises:

[0020] Step 8, the diameter D 直段杆 of the straight section rod is the same as the diameter D 大端 of the large end, the diameter D 限位台 of the limiting table is greater than the diameter D 大端 of the large end by at least 1 mm.

[0021] In an alternative embodiment, the outer side of the straight section rod and the limiting table is adapted to be assembled with a dust cover, and step 8 further comprises: the length L直段杆 and the diameter D of the limiting platform 限位台 is adapted to be revised according to the design input of the dust cover.

[0022] Since the automobile ball hinge assembly includes the dust cover, the dust cover is assembled and connected outside the straight section rod of the ball pin and the limiting platform. By revising the length of the straight section rod and the diameter of the limiting platform according to the design input of the dust cover, the straight section rod and the limiting platform can be made to satisfy the sufficient contact area between the straight section rod and the limiting platform and the surface of the sealing lip of the dust cover, so as to maintain the sealing state.

[0023] In an alternative embodiment, the design method comprises:

[0024] Step 9, the taper ratio of the tapered rod is 1:6, the diameter D of the small end 小端 is adapted to be determined according to the thickness of the brake knuckle.

[0025] Since the automobile ball hinge assembly has an acting force when assembled with the brake knuckle, the brake knuckle needs to be checked for crushing force. The thickness of the brake knuckle is the same as the height of the tapered rod. By setting the diameter of the small end of the tapered rod according to the thickness of the brake knuckle, the safety of the automobile ball hinge connected with the brake knuckle during use can be ensured.

[0026] In an alternative embodiment, the automobile ball hinge comprises a threaded rod connected with the small end, and the design method comprises:

[0027] Step 10, the diameter of the threaded rod is smaller than the diameter D of the small end 小端 , and the corresponding bolt is selected according to the diameter D of the small end 小端 , so as to obtain the radius r of the threaded rod.

[0028] Since the bolt is generally a series product and belongs to a mature specification product, the diameter of the threaded rod is generally slightly smaller than the diameter of the small end of the tapered rod. The bolt that is suitable for the threaded rod can be initially selected by the diameter of the small end, and then the radius of the threaded rod matched with the bolt can be known.

[0029] In an alternative embodiment, the step 10 further comprises:

[0030] According to the selected bolt, the corresponding thread pitch diameter thread angle ψ, tooth type angle α, and plane equivalent friction radius R can be obtained;

[0031] By performing force analysis on the threaded rod through software, the tightening torque M 力矩 can be obtained, and the axial force F a of the threaded rod can be obtained according to the calculation formula , and the axial force F a needs to satisfy F a ≥ns .F 2max ;

[0032] Wherein, tanψ=P / 2πr, the thread friction coefficient μ1 and the installation surface friction coefficient μ2 can be selected as the empirical value 0.12-0.18, P is the thread distance of the bolt, n s is the safety factor.

[0033] The axial force of the threaded rod can be obtained by force analysis of the threaded rod through software, and even if the axial force meets the actual demand in the design, the problem of fracture of the automobile ball hinge in use can be avoided.

[0034] In an alternative embodiment, the step 10 further comprises:

[0035] The length of the threaded rod at least meets the requirement of exposing 2-3 threads after assembly.

[0036] By setting the length of the threaded rod to at least meet the requirement of exposing 2-3 threads after assembly, the assembly can be facilitated, the strength can be improved, and the contact area with the nut can be increased.

[0037] In an alternative embodiment, the ball neck comprises a first circular arc, a second circular arc and a third circular arc, two ends of the second circular arc are connected with the first circular arc and the third circular arc respectively, the first circular arc is connected with the ball head, the starting end of the first circular arc is the endpoint of the chord length of the ball head, and the terminal end of the first circular arc has a height less than the chord height of the ball head.

[0038] The third circular arc is connected with the limiting table of the ball pin, and the starting end of the third circular arc is the endpoint of the straight section rod of the limiting table away from the ball pin, and the radius of the circle where the terminal end of the third circular arc is located is 3mm-5mm.

[0039] The ball neck of the automobile ball hinge is between the ball head and the ball pin, the ball neck comprises a first circular arc, a second circular arc and a third circular arc, the first circular arc is connected with the ball head, the third circular arc is connected with the ball pin, and the second circular arc connects the first circular arc and the third circular arc, the first circular arc is designed in relation to the chord length and chord height of the ball head, and the third circular arc is designed in relation to the limiting table of the ball pin, so that the production and design of the automobile ball hinge are more in line with the actual demand.

[0040] In an alternative embodiment, the design method comprises:

[0041] Step 11, static strength checking of the automobile ball hinge is performed by using software to obtain the yield load of the ball pin that the automobile ball hinge can withstand, and the yield load needs to meet greater than or equal to 20KN.

[0042] The static strength of the automobile ball hinge is checked by software, so as to check whether the yield load of the ball pin damage that can be borne by the automobile ball hinge is within the required range, so that the design of the automobile ball hinge can be more in line with the actual demand, and the problem of fracture in the subsequent use process is effectively avoided.

[0043] In a second aspect, the application provides an automobile ball hinge designed by the above design method.

[0044] In a third aspect, the application provides an automobile ball hinge assembly, comprising:

[0045] A ball bowl seat;

[0046] A ball hinge sleeve arranged in the ball bowl seat;

[0047] The above automobile ball hinge is movably arranged in the ball hinge sleeve.

[0048] The beneficial effects of the application are:

[0049] (1) The maximum load of the automobile ball hinge is simulated by software, the minimum ball head diameter is calculated according to the strength calculation formula, then the minimum swing angle of the automobile ball hinge is obtained by software modeling and simulation analysis, and the minimum chord length can be obtained from the minimum swing angle and the minimum ball head diameter, and the projection area S j ′ of the chord length of the ball head on the plane perpendicular to the maximum radial force F1maX can be calculated, and the strength σ j ′ corresponding to the projection area S j ′ can be calculated again according to the strength calculation formula, and the minimum ball head diameter is optimized according to a certain step increment until σ j ′ meets the strength requirement, that is, the optimal ball head diameter can be obtained, that is, by using the design method of the application, the maximum load and strength of the automobile ball hinge can be considered in the early design of the automobile ball hinge, so that the ball head diameter can be accurately designed, and the problems of fracture and abnormal wear after sale can be effectively avoided, the development efficiency is improved, and the development cycle and cost are reduced.

[0050] (2) The CAE pull-out force check of the automobile ball hinge can prevent the automobile ball hinge from being pulled out and failing during movement, so that the design of the automobile ball hinge is more in line with the actual demand.

[0051] (3) Since the ball joint of an automobile can be simplified as a cantilever beam structure subjected to concentrated alternating loads, the installation position from the center of the ball head to the tapered rod of the ball pin, i.e. the length of the lever arm at the large end, is L. At any position of this length, the shear force remains unchanged, and the bending moment is proportional to the lever arm L. Therefore, the bending strength requirement of the large end of the ball pin is high. This invention considers the bending strength factor in the design stage of the large end diameter of the tapered rod of the ball pin, so that the size of the ball pin obtained by the design calculation can be more suitable for the bending strength in actual use, and avoid the problem of subsequent breakage.

[0052] (4) Since the automotive ball joint assembly includes a dust cover, which is assembled and connected to the outside of the straight section rod and the limiting platform of the ball pin, the present invention can modify the length of the straight section rod and the diameter of the limiting platform according to the design input of the dust cover, so that the straight section rod and the limiting platform have sufficient contact area with the sealing lip surface of the dust cover to maintain the sealing state.

[0053] (5) Since there is an interaction force between the automotive ball joint assembly and the brake steering knuckle, the crushing force of the brake steering knuckle needs to be checked. The thickness of the brake steering knuckle is the same as the height of the tapered rod. By setting the small end diameter of the tapered rod according to the thickness of the brake steering knuckle, the safety of the connection between the automotive ball joint and the brake steering knuckle during use can be guaranteed.

[0054] (6) Since bolts are generally a series of products and belong to mature specifications, the diameter of the threaded rod is generally set slightly smaller than the small end diameter of the tapered rod. The present invention can initially select the bolt that is compatible with the threaded rod by the small end diameter, and then the radius of the threaded rod that is matched with the bolt can be known.

[0055] (7) This invention analyzes the stress on the threaded rod using software and calculates the axial force of the threaded rod according to the calculation formula. Even if the axial force meets the actual requirements during the design, it can avoid the problem of breakage of the ball joint in the use of automobiles.

[0056] (8) By setting the length of the threaded rod to at least 2-3 threads exposed after assembly, the present invention can facilitate assembly, improve strength, and increase the contact area with the nut.

[0057] (9) The ball neck of the automotive ball joint is located between the ball head and the ball pin. The ball neck includes a first arc, a second arc and a third arc. The first arc is connected to the ball head, the third arc is connected to the ball pin, and the second arc connects the first arc and the third arc. By designing the first arc in relation to the chord length and chord height of the ball head, and designing the third arc in relation to the limiting platform of the ball pin, the present invention makes the production design of the automotive ball joint more in line with actual needs.

[0058] (10) The application carries out static strength checking on the automobile ball hinge through software, so as to check whether the yield load of the ball pin damage that the automobile ball hinge can bear is within the required range, so that the design of the automobile ball hinge can be more in line with the actual demand, and the problem of fracture in the subsequent use process is effectively avoided. BRIEF DESCRIPTION OF DRAWINGS

[0059] In order to more clearly illustrate the specific embodiments of the present application or the technical solutions in the prior art, the drawings needed to be used in the specific embodiments or the prior art description will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present application, and other drawings can also be obtained by those skilled in the art without creative labor on the basis of these drawings.

[0060] Figure 1 It is a schematic diagram of load and movement of an automobile ball hinge assembly of an embodiment of the present application;

[0061] Figure 2 It is a schematic diagram of the structure of an automobile ball hinge of an embodiment of the present application;

[0062] Figure 3 It is a schematic diagram of the structure of a threaded rod;

[0063] Figure 4 It is a schematic diagram of the structure of an automobile ball hinge assembly;

[0064] Figure 5 It is a schematic diagram of the structure of a spherical friction pair and positive pressure.

[0065] BRIEF DESCRIPTION OF DRAWINGS

[0066] Among them, 1, ball head; 2, ball neck; 3, conical rod; 301, large end; 302, small end; 303, straight section rod; 304, limit table; 4, threaded rod; 5, dust cover; 6, brake knuckle; 7, nut; 8, ball bowl seat; 9, ball hinge sleeve; 10, ball hinge pressing plate. DETAILED DESCRIPTION

[0067] In order to make the purpose, technical scheme and advantages of the embodiments of the present application more clear, the technical scheme in the embodiments of the present application will be described clearly and completely below in combination with the drawings in the embodiments of the present application. Obviously, the described embodiments are some embodiments of the present application, not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the present application. It should be understood that the preferred embodiments are only for illustrating the present application, not for limiting the protection scope of the present application.

[0068] It is to be understood that the figures provided in the following embodiments are only schematic and that the drawings are only intended to facilitate the understanding of the application, and that the shapes, the number, and the dimensions of the components shown in the drawings are not necessarily drawn to scale, and that the shapes, the number, and the dimensions of the components in actual implementation can be arbitrarily changed, and the layout of the components can be more complex.

[0069] The embodiments of the application are described below in conjunction with Figures 1 to 5 .

[0070] According to the embodiments of the application, in a first aspect, a design method of an automobile ball joint is provided, the automobile ball joint comprising a ball head 1, a ball neck 2 and a ball pin, the design method comprising:

[0071] Step 1, simulating the maximum load of the automobile ball joint by software, and decomposing the maximum radial force F1max and the maximum axial force F2max borne by the automobile ball joint;

[0072] Step 2, according to the strength calculation formula wherein σ j ≤25-30MPa, and the projection area formula S j of the ball head 1 on the plane perpendicular to the maximum radial force F1max 球头 2 , the minimum ball head diameter D′ 球头 can be obtained.

[0073] Step 3, building an assembly model of the automobile suspension system by software, and obtaining the minimum swing angle β′ of the automobile ball joint by simulation analysis;

[0074] Step 4, according to the formula L′ 弦长 =D′ 球头 ·sinβ′, the minimum chord length L′ 弦长 can be obtained.

[0075] Step 5, according to the formula and the strength calculation formula in Step 2, σ j ′ is obtained, if σ j ′ does not satisfy σ j ′≤25-30MPa, then the minimum ball head diameter D′ 球头 is increased by a certain step size for optimization design, and Steps 4 and 5 are repeated until σ j ′ satisfies σ j ′≤25-30MPa, then the corresponding ball head diameter D′ 球头 is the optimal ball head diameter D 球头 .

[0076] The maximum load on the automotive ball joint is simulated using software, and the minimum ball head diameter is calculated based on the strength formula. Then, the minimum swing angle of the ball joint is obtained through software modeling and simulation analysis. From the minimum swing angle and the minimum ball head diameter, the minimum chord length can be calculated. From this chord length, the projected area S of the ball head 1 on the plane perpendicular to the maximum radial force F1max can be calculated. j ′, and the strength calculation formula can be used to calculate the projected area S again. j The corresponding strength σ' j The minimum ball head diameter is then optimized using a certain step size increment until σ is achieved. j By meeting the strength requirements, the optimal ball joint diameter can be obtained. That is, by adopting the design method of this invention, the maximum load and strength of the automotive ball joint can be considered in the early stage of automotive ball joint design, so that the ball joint diameter can be accurately designed, effectively avoiding problems such as breakage and abnormal wear after sales, improving development efficiency, and reducing development cycle and cost.

[0077] Specifically, in step 1, the loads on the car ball joint under various working conditions can be decomposed by finite element software simulation. After fitting, the maximum radial force F1max and the maximum axial force F2max on the car ball joint can be obtained.

[0078] Specifically, in step 2, since the car ball joint is a body of revolution and all its cross-sections are circular, the diameter of the cross-section of ball head 1 is the diameter of the sphere, and the projected area S of ball head 1 on the plane perpendicular to the radial maximum force F1max is... j =1 / 4·π·D 球头 2 During the design process, empirical values ​​can be used to determine σ. j Select a σ within the range of ≤25~30MPa j Find the minimum diameter of the ball head, D′. 球头 .

[0079] Specifically, in step 3, the assembly model of the car suspension system can be built using 3D modeling software, and the mechanism motion module can be used for simulation analysis to simulate the entire vertical jump of the car tires, thereby obtaining the minimum swing angle β′ of the car ball joint.

[0080] In the final assembly of the ball joint assembly, the stamping and riveting of the ball joint sleeve 9 involves applying a positive pressure P to the ball cup seat 8 and the ball head 1. 正压力 The process, therefore, the force-bearing area S of the spherical head surface. 球头 Let S be the area of ​​the inner spherical surface of the spherical bowl seat 8. 球碗座 S 球头 =S 球碗座 ,like Figure 5 As shown, the analysis of the ball-shaped bowl seat 8 will be used as an example for explanation.

[0081] When the ball neck 2 swings, the angle of contact between it and the ball cup seat 8 is greater than the minimum swing angle β′. The minimum chord length L′ of the projection plane can be obtained by spatial verification using β′. 弦长 ,like Figure 5 As shown, L′ 弦长 =D′ 球头 ·sinβ′.

[0082] Similarly, as Figure 5 As shown, it can be done according to the formula. Find the projected area S of the chord length of the ball head 1 on the plane perpendicular to the maximum radial force F1max. j ′, and the smallest ball head diameter D′ 球头 The optimization design is carried out according to a certain step size increment, such as 1mm or 2mm. As a possible implementation method, the certain step size increment can also be other specific values, which are not restricted in detail here.

[0083] Specifically, in step 5, when optimizing the design of the minimum ball head diameter according to a certain step size increment, and substituting the calculation formulas from steps 4 and 5, the calculation is repeated until σ is achieved for the first time. j The ball head diameter D is satisfied within the range of 25 to 30 MPa. 球头 That is, the diameter D of the ball head we need for our design. 球头 .

[0084] The design method in this embodiment also includes:

[0085] Step 6: Perform CAE (Computer-Aided Engineering) pull-out force verification on the automotive ball joint according to the design pull-out force value ≥ 10 * maximum single-wheel full-load load, using L′ as the value. 弦长 By performing optimization design with a certain step size increment, the optimal chord length L is obtained. 弦长 The optimal swing angle β is then obtained by revising the calculation, where the maximum single-wheel full load is the design input given by the whole vehicle.

[0086] Specifically, the increment of the chord length can be 1 mm or 2 mm. As an alternative implementation, the increment can also be other specific values, which are not limited here.

[0087] By performing CAE pull-out force verification on automotive ball joints, it is possible to prevent the ball joints from coming out of control during operation, making the design of automotive ball joints more in line with actual needs.

[0088] In this embodiment, the ball pin includes a tapered rod 3, which includes a large end 301 and a small end 302. The large end 301 is located close to the ball head 1. The design method includes:

[0089] Step 7, according to the bending strength formula Among them, M max =F 1max ·n s ·L, and σ s n is the yield strength of the material of the automotive ball joint. s For safety factor; L is the length from the center of the ball head 1 to the large end 301 of the conical rod 3, and L≤D 球头 The diameter D of the large end 301 can be obtained. 大端 .

[0090] Since an automotive ball joint can be simplified as a cantilever beam structure subjected to concentrated alternating loads, the installation position from the center of the ball head 1 to the tapered rod 3 at the large end 301, with a lever arm length of L, is as follows: Figure 1 As shown, at any position of the cross section along this length, the shear force remains constant, and the bending moment is proportional to the lever arm L. Therefore, the bending strength requirement for the large end 301 of the ball pin is relatively high. By considering the bending strength factor in the design stage of the diameter of the large end 301 of the tapered rod 3 of the ball pin, the size of the ball pin obtained by the design calculation can be more suitable for the bending strength in actual use, thus avoiding the problem of subsequent breakage.

[0091] Specifically, in one embodiment, n s =1.5, L=D 球头 The ball joint of the car is made of 40Cr steel. Of course, in other embodiments, n s It can also be other specific values, with L being slightly less than D. 球头 The material of automotive ball joints is 42CrMo alloy structural steel, or other types of steel.

[0092] like Figure 2 As shown, the ball pin in this embodiment includes a straight section rod 303 and a limiting platform 304. One end of the straight section rod 303 is connected to the large end 301, and the other end is connected to one end of the limiting platform 304. The other end of the limiting platform 304 is located near the ball neck 2. The design method includes:

[0093] Step 8, the diameter D of the straight section rod 303 直段杆 The diameter D of the large end 301 大端 Similarly, the diameter D of the limiting stage 304 is... 限位台 The diameter D is greater than that of the large end 301. 大端 At least 1mm.

[0094] In this embodiment, the outer sides of the straight rod 303 and the limiting platform 304 are suitable for mounting and connecting the dust cover 5. Step 8 also includes: the length L of the straight rod 303 直段杆 The diameter D of the limiting stage 304 限位台 Suitable for revision based on the design input of dust cover 5.

[0095] Since the automobile ball hinge assembly comprises the dust cover 5, the dust cover 5 is assembled and connected outside the straight section rod 303 of the ball pin and the limiting table 304, by inputting and revising the length of the straight section rod 303 and the diameter of the limiting table 304 according to the design of the dust cover 5, the straight section rod 303 and the limiting table 304 can satisfy sufficient contact area with the sealing lip surface of the dust cover 5 to maintain the sealing state.

[0096] Specifically, the diameter of the limiting table 304 in the embodiment is greater than the diameter of the large end 301 by 1 mm, if the diameter of the limiting table 304 is too small than the diameter of the large end 301, it can cause poor limiting of the dust cover 5 and slip off, and if the diameter of the limiting table 304 is too large, it can cut the dust cover 5 at the swing limit of the automobile ball hinge, causing damage to the dust cover 5. As an alternative embodiment, the diameter of the limiting table 304 can be greater than the diameter of the large end 301 by 2 mm or 3 mm.

[0097] Since there is an acting force between the automobile ball hinge assembly and the brake knuckle 6, the brake knuckle needs to be checked for crushing force, and the thickness of the brake knuckle 6 is the same as the height of the tapered rod 3, as shown in Figure 4 The design method in the embodiment comprises the following steps: 小端 The thickness of the brake knuckle 6 is determined, so that the safety of the automobile ball hinge connected with the brake knuckle during use can be ensured. As an alternative embodiment, the taper ratio of the tapered rod 3 can be 1:8 or other empirical values, which are not limited here.

[0098] As shown in Figure 2 The automobile ball hinge in the embodiment comprises a threaded rod 4 connected with the small end 302, and the design method comprises the following steps:

[0099] Step 10, the diameter of the threaded rod 4 is smaller than the diameter D 小端 of the small end 302, and the corresponding bolt is selected according to the diameter D 小端 of the small end 302, so that the radius r of the threaded rod 4 can be obtained.

[0100] The bolt is generally a series product, which belongs to a mature specification product. Generally, the diameter of the threaded rod 4 is slightly smaller than the diameter of the small end of the tapered rod 3, the bolt suitable for the threaded rod 4 can be initially selected through the small end diameter, and then the radius of the threaded rod 4 matched with the bolt can be known.

[0101] Step 10 further comprises the following steps:

[0102] According to the selected bolt, the corresponding thread pitch diameter, thread angle ψ, tooth type angle α, and plane equivalent friction radius R can be obtained, as shown in Figure 3 .

[0103] By force analysis of the threaded rod 4 through software, the tightening torque M 力矩 , and according to the calculation formula , the axial force F of the threaded rod 4 can be obtained a , and the axial force F a needs to meet F a ≥ n s · F 2max ;

[0104] Wherein, tanψ=P / 2πr, the threaded friction coefficient μ1 and the installation surface friction coefficient μ2 can be selected according to the empirical value 0.12-0.18, P is the threaded distance of the bolt, n s is the safety factor. Specifically, μ1 and μ2 can both be 0.15, and n s can be 1.5.

[0105] By force analysis of the threaded rod 4 through software, the axial force of the threaded rod 4 can be obtained according to the calculation formula, and even if the axial force meets the actual demand during design, the problem of fracture of the automobile ball hinge during use can be avoided.

[0106] In order to facilitate assembly, improve strength, and increase the contact area with the nut 7, the step 10 in the embodiment further includes that the length of the threaded rod 4 at least meets 2-3 threads exposed after assembly.

[0107] The ball neck 2 in the embodiment includes a first circular arc, a second circular arc, and a third circular arc, the two ends of the second circular arc are connected with the first circular arc and the third circular arc respectively, the first circular arc is connected with the ball head 1, the starting end of the first circular arc is the endpoint of the chord length of the ball head 1, and the terminal end of the first circular arc is lower than the chord height of the ball head 1, where the chord height is the distance between the plane where the chord length is located and the plane where the vertex of the complete ball is located, and the diameter where the terminal end of the first circular arc is located is the minimum diameter D 球颈 of the ball neck 2. Figure 5

[0108] The third circular arc is connected with the limiting table 304 of the ball pin, the starting end of the third circular arc is the endpoint of the straight section rod 303 of the limiting table 304 away from the ball pin, and the radius of the circle where the terminal end of the third circular arc is located is 3mm-5mm.

[0109] The ball neck 2 of the automobile ball hinge is between the ball head 1 and the ball pin, the ball neck 2 includes a first circular arc, a second circular arc, and a third circular arc, the first circular arc is connected with the ball head 1, the third circular arc is connected with the ball pin, the second circular arc connects the first circular arc and the third circular arc, the first circular arc is designed in relation to the chord length and chord height of the ball head 1, and the third circular arc is designed in relation to the limiting table 304 of the ball pin, so that the production and design of the automobile ball hinge are more in line with the actual demand.

[0110] ​Specifically, the end of the first segment of the circular arc of the ball neck 2 is flush with the top end of the ball hinge sleeve 9. Since the diameter of the circle on which the end of the first segment of the circular arc is located is the minimum diameter of the ball neck 2, by making the end of the first segment of the circular arc of the ball neck 2 flush with the top end of the ball hinge sleeve 9, the first segment of the circular arc of the ball neck 2 is flush with or lower than the top end of the ball hinge sleeve 9 in the case of extreme working conditions or machining tolerance, so that the first segment of the circular arc does not contact the force first in the swinging process. As a convertible embodiment, the end of the first segment of the circular arc can also be lower than the chord height of the ball head 1, and the end of the first segment of the circular arc is lower than the top end of the ball hinge sleeve 9.

[0111] The design method in this embodiment includes:

[0112] Step 11, checking the static strength of the automobile ball hinge by using software to obtain the yield load of the ball pin failure that the automobile ball hinge can withstand, and the yield load needs to be greater than or equal to 20KN.

[0113] The static strength of the automobile ball hinge is checked by software to check that the yield load of the ball pin failure that the automobile ball hinge can withstand is within the required range, so that the design of the automobile ball hinge can better meet the actual needs and effectively avoid the problem of fracture in the subsequent use process.

[0114] Specifically, the static strength of the automobile ball hinge can be checked by using CAE analysis means. CAE analysis, i.e. computer aided engineering analysis, is a technology that uses computer technology to assist in solving the problems of mechanical performance analysis, structure optimization, etc. in complex engineering and product design. The core of CAE analysis is to simulate and analyze the design of engineering or product by computer software to predict its performance, optimize the design scheme, reduce the need for physical prototype testing, thereby reducing cost and improving design efficiency. This analysis technology is widely used in many fields, including but not limited to automobile design, aerospace, mechanical manufacturing, etc., among which automobile CAE analysis places particular emphasis on the performance analysis, prediction and optimization of automobile engineering or automobile products, and thus belongs to a very mature analysis means in the field, which will not be described here.

[0115] If the yield load of the ball pin failure that the automobile ball hinge can withstand is less than 20KN in the checking process, the diameter of the ball head 1 or the diameter of the large end of the ball pin can be increased to adjust until the yield load of the ball pin failure that the automobile ball hinge can withstand is greater than or equal to 20KN.

[0116] The design method of the automobile ball hinge provided in this embodiment can accurately design the diameter of the ball head 1 and the diameter of the ball pin at the initial design stage, which can effectively avoid problems such as fracture and abnormal wear after sale, improve development efficiency, and reduce development cycle and cost.

[0117] According to the second aspect of the embodiment of the present application, the automobile ball hinge is designed by the above design method, so that the automobile ball hinge can effectively prevent the problems of fracture and abnormal wear during use, and the service life of the automobile ball hinge is improved.

[0118] The automobile ball hinge in the embodiment can effectively prevent the problems of fracture and abnormal wear during use, and the service life of the automobile ball hinge is improved.

[0119] According to the third aspect of the embodiment of the present application, the automobile ball hinge assembly comprises a ball cup seat 8, a ball hinge sleeve 9 arranged in the ball cup seat 8, and the automobile ball hinge described above movably arranged in the ball hinge sleeve 9.

[0120] As shown in Figure 4 , the automobile ball hinge assembly mainly comprises a ball hinge, a ball hinge sleeve 9, a ball cup seat 8, a ball hinge pressing plate 10, and a dust cover 5, and the main force component is the ball hinge.

[0121] The ball hinge comprises a ball head 1, a ball pin, and a ball neck 2, and the ball pin comprises a threaded rod 4, a tapered rod 3, a straight rod 303, and a limiting platform 304, which are arranged in sequence from top to bottom. By arranging the tapered rod 3, the ball hinge has good strength and certain guiding effect. The threaded rod 4 is fastened with the brake steering knuckle 6 through the nut 7. By reserving 2-3 threads on the outer side of the threaded rod 4 during design, the contact area of the threaded rod 4 and the nut 7 can be increased, and the connection strength can be improved.

[0122] The ball head 1 is in contact with the spherical surface in the ball cup seat 8 to form a spherical friction pair, and the end face of the tapered rod 3 of the ball pin is subjected to shearing force and bending moment. According to the principle of tribology, two objects in contact with each other must have a normal pressure to press the two objects together. Because no two surfaces are completely flat, the contact point only occurs at the highest points of the surfaces of the two objects. The existence of the normal pressure causes the highest points of the surfaces to be extruded and deformed until the contact pressure of the surfaces of the two objects reaches balance and is locked with each other. This process is friction.

[0123] As shown in Figure 5 , in the general assembly of the automobile ball hinge assembly, the punching and riveting of the ball hinge sleeve 9 is the process of applying the normal pressure P 正压力 of the ball cup seat 8 and the ball head 1 by the ball hinge pressing plate 10.

[0124] Therefore, as shown in Figure 5As shown, the ball socket 8 in the embodiment is a notch covering structure, and the slot angle θ of the ball socket 8 is less than 30°. The notch setting can reduce the contact area between the ball head 1 and the ball socket 8, and can improve the steering sensitivity of the automobile ball hinge assembly. Specifically, the slot angle θ of the ball socket 8 can be set to 25°. As a variable implementation, the slot angle θ of the ball socket 8 can also be set to other specific values.

[0125] Of course, in other embodiments, the ball socket 8 can also be a global head covering structure without a notch to improve wear resistance.

[0126] The automobile ball hinge assembly in the embodiment also necessarily has the same technical effects as the automobile ball hinge described above, and will not be described here.

[0127] Although the embodiments of the present application are described in conjunction with the drawings, various modifications and changes can be made by those skilled in the art without departing from the spirit and scope of the present application, and such modifications and changes fall within the scope defined by the appended claims.

Claims

1. A method for designing a vehicle ball joint, which comprises a ball head (1), a ball neck (2) and a ball pin, characterized in that, The design method comprises: Step 1, simulate the maximum load of the automobile ball joint by software simulation, and decompose the radial maximum force F 1max and the axial maximum force F 2max experienced by the automobile ball joint Step 2, intensity calculation formula where σ j ≤ 25 ~ 30 MPa, and the formula S of the projected area of the ball head (1) on the plane perpendicular to the radial maximum force F1max j = 1 / 4 - π - D 球头 2 The minimum ball head diameter D' can be obtained 球头 ; Step 3, the minimum swing angle β' of the automobile ball joint is obtained by simulating and analyzing the assembly numerical model of the automobile suspension system built by software; Step 4, the minimum chord length L' is obtained according to the formula L' = D' • sin β' 弦长 球头 弦长 ;​​ Step 5, σ ′ is calculated according to the formula j ′, if σ j ′ does not satisfy σ j ′≤25-30MPa, then the smallest ball head diameter D′ 球头 The optimization design is carried out according to a certain step increment, and steps 4 and 5 are repeated until σ j ′ satisfies σ j ′≤25-30MPa, then the corresponding ball head diameter D′ 球头 is the optimal ball head diameter D 球头 .

2. The design method of the automotive ball hinge according to claim 1, characterized in that, The design method comprises: Step 6, CAE pull-out force checking is performed on the automobile ball hinge according to the pull-out force design value > 10 * the maximum single wheel full load, to L' 弦长 Optimization design is carried out according to a certain step increment, and the optimal chord length L 弦长 is obtained, and the optimal swing angle β is obtained by revision, wherein the maximum single wheel full load is a design input given by the whole vehicle.

3. The design method of the automotive ball hinge according to claim 1, characterized in that, The ball pin comprises a tapered rod (3), the tapered rod (3) comprises a large end (301) and a small end (302), the large end (301) is arranged close to the ball head (1), and the design method comprises: Step 7, according to the bending strength formula where M max = F 1max · n s · L, and σ s is the yield limit of the material of the automotive ball joint, n s is a safety factor, L is the length of the ball center of the ball head (1) to the large end (301) of the conical rod (3), and L≤D 球头 , the diameter D 大端 of the large end (301) can be obtained.

4. The design method of the automotive ball hinge according to claim 3, characterized in that, n s = 1.5; and / or, L = D 球头 ; and / or, the material of the automobile spherical hinge is 40Cr steel or 42CrMo alloy structural steel.

5. The design method of the automotive ball hinge according to claim 3, characterized in that, The ball pin comprises a straight section rod (303) and a limiting table (304), one end of the straight section rod (303) is connected with the large end (301), the other end is connected with one end of the limiting table (304), the other end of the limiting table (304) is arranged close to the ball neck (2), and the design method comprises: Step 8, the diameter D of the straight section rod (303) 直段杆 is the same as the diameter D of the large end (301) 大端 The diameter D of the limiting platform (304) 限位台 is greater than the diameter D of the large end (301) 大端 at least 1 mm.

6. The design method of a vehicle ball hinge according to claim 5, wherein The outer side of the straight section rod (303) and the limiting table (304) is suitable for assembling a dust cover (5). Step 8 further comprises: the length L of the straight section rod (303) 直段杆 and the diameter D of the limiting table (304) 限位台 is suitable for revision according to the design input of the dust cover (5).

7. The design method of a automotive ball joint according to any one of claims 3 to 6, characterized in that, The design method comprises: Step 9, the taper ratio of the tapering rod (3) is 1:6, the diameter D of the small end (302) is 20mm 小端 Suitable for determining according to the thickness of the brake knuckle (6).

8. The design method of the automotive ball hinge according to claim 7, characterized in that, The automobile ball joint comprises a threaded rod (4), the threaded rod (4) is connected with the small end (302), and the design method comprises: Step 10, the diameter of the threaded rod (4) is less than the diameter D of the small end (302) 小端 According to the diameter D of the small end (302) 小端 The corresponding bolt is selected, that is, the radius r of the threaded rod (4) is obtained.

9. The design method of a vehicle ball hinge according to claim 8, wherein The step 10 further comprises: According to the selected bolt, the corresponding thread pitch diameter thread angle ψ, tooth type angle α, and plane equivalent friction radius R can be obtained; By force analysis of the threaded rod (4) through software, the tightening torque M 力矩 can be obtained , and according to the calculation formula , the axial force F a of the threaded rod (4) can be obtained a , and the axial force F a needs to meet F a ≥ n s · F 2max ; where tan ψ = P / 2πr, the thread friction coefficient μ1 and the mounting surface friction coefficient μ2 can be selected as empirical values of 0.12-0.18, P is the thread distance of the bolt, n s is the safety factor.

10. The design method of the automotive ball hinge according to claim 9, wherein The step 10 further comprises: The length of the threaded rod (4) at least meets the requirement of exposing 2-3 threads after assembly.

11. The design method of a automotive ball joint according to any one of claims 1 to 6, 8 to 10, characterized in that, The ball neck (2) comprises a first segment circular arc, a second segment circular arc and a third segment circular arc, two ends of the second segment circular arc are connected with the first segment circular arc and the third segment circular arc respectively, and the first segment circular arc is connected with the ball head (1); The starting end of the first segment circular arc is the end point of the chord length of the ball head (1), and the end height of the first segment circular arc is less than the chord height of the ball head (1); The third segment circular arc is connected with the limiting table (304) of the ball pin, the starting end of the third segment circular arc is the end point of the limiting table (304) away from the straight section rod (303) of the ball pin, and the radius of the circle where the end of the third segment circular arc is located is 3mm-5mm.

12. The design method of an automotive ball joint according to any one of claims 1 to 6, 8 to 10, characterized in that, The design method comprises: Step 11, the static strength of the automobile ball joint is checked by using software to obtain the yield load of the ball pin that can be borne by the automobile ball joint, and the yield load needs to meet the requirement of being greater than or equal to 20KN.

13. A vehicle ball joint, characterized in that Designed by the design method in any one of claims 1-12.

14. An automotive ball joint assembly characterized by, Comprise: A ball bowl seat (8); A ball joint sleeve (9) arranged in the ball bowl seat (8); The automobile ball joint in claim 13 is movably arranged in the ball joint sleeve (9).

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