CN202703154U - Multi-connecting rod rectilinear translation type suspension using ball spline pair - Google Patents

Abstract

The utility model relates to a multi-connecting rod rectilinear translation type suspension using ball spline pairs. The suspension comprises a spring absorber system, a wheel, an vehicle body and a steering knuckle, as well as an upper-side first suspension branch chain, an upper-side second suspension branch chain, a lower-side first suspension branch chain and a lower-side second suspension branch chain, wherein the spring absorber system is in hinged connection with the steering knuckle and the vehicle body respectively, the steering knuckle cooperates with the wheel through a wheel hub unit, and two ends of the four suspension branch chains are hinged to the steering knuckle and the vehicle body respectively. The beneficial effects of the utility model are that positional parameters such as a wheel camber angle, a kingpin inclination angle and caster angle, a toe-in (toe-out), a left and right wheel span and a front and back wheel base can always remain unchanged when the wheel is bounced up and down, thereby effectively reducing abrasion of tires and effectively raising operation stability, running smoothness and riding comfortableness of an automobile; and the suspension branch chains are simple in structure, and the ball spline pairs are replaceable after being worn, thereby increasing service life of the suspension branch chains.

Description

Multi-connecting-rod linear translation type suspension with ball spline pair

Technical Field

The utility model relates to an automotive suspension system, especially an adopt vice many connecting rods straight line translation formula suspension of ball spline.

Background

Suspension is a general term for devices which ensure elastic connection between a wheel or an axle and a vehicle bearing system (a frame or a bearing type vehicle body) and can transmit load, cushion impact, damp vibration, adjust the position of the vehicle body during driving of the vehicle, and the like. The general suspension mainly comprises an elastic element, a damping device and a guide mechanism. In some cases, a component can serve two or three functions, for example, a leaf spring can serve as both the elastic element and the guide mechanism. The function of the guiding mechanism is to ensure reliable transmission of all forces and moments between the wheel and the body or frame and to determine the displacement characteristics of the wheel relative to the body or frame. The guide mechanism determines the change conditions of the motion track and the wheel positioning parameters when the wheels jump, and the positions of the front and rear roll centers and the pitch center of the automobile, thereby greatly influencing the operation stability and the pitch resistance of the whole automobile.

According to the characteristics of the guide mechanism, the automobile suspension mainly can be divided into a non-independent suspension and an independent suspension. A typical feature of a non-independent suspension is that the left and right wheels are coupled by a rigid beam or non-decoupled axle, which directly affects the wheel on the other side when the wheel on one side is jumping. The left wheel and the right wheel of the independent suspension are respectively connected with a vehicle body or a vehicle frame in an 'independent' mode or form a disconnected axle. In addition, there is a semi-independent suspension featuring an intermediate between the non-independent suspension and the independent suspension. The disadvantages of the non-independent suspension are obvious, such as mutual influence of the jumping of the left wheel and the right wheel, large non-suspension mass and the like, and the requirements of the current automobile on the aspects of driving smoothness and operating stability cannot be met, so that the independent suspension is greatly developed.

The independent suspension has the structural characteristics that wheels on two sides are separately connected with a vehicle body or a vehicle frame through the elastic suspension, and an axle is in a disconnected mode. Therefore, the independent suspension has the following advantages: in a certain deformation range of the elastic element of the suspension, wheels on two sides can move independently without mutual influence, so that the vibration of a frame and a vehicle body can be reduced when the vehicle runs on an uneven road, the adverse phenomenon that a steering wheel continuously deflects is favorably eliminated, the linear running capacity of the vehicle is improved, and good operation stability is ensured. And secondly, the unsprung mass of the automobile is reduced. In the case of a non-independent suspension, the entire axle and wheel belong to the unsprung mass section. Under the condition of an independent suspension, for a drive axle, a main speed reducer, a differential and a shell of the differential are fixed on a frame to form a sprung mass; for a steer axle, it has only a kingpin and knuckle, while the central integral beam is no longer present. So with independent suspensions the unsprung mass, including the wheel mass and all or part of the mass of a part of the suspension system, is significantly smaller than with non-independent suspensions. The smaller the unsprung mass is when the road condition and the vehicle speed are the same, the smaller the impact load is on the suspension, so the use of an independent suspension can improve the ride comfort of the vehicle and the grounding performance of the tires. And thirdly, when the disconnected axle is adopted, the position of the engine assembly can be lowered and moved forwards to lower the gravity center of the automobile, so that the driving stability of the automobile is improved. Meanwhile, the wheel has larger up-and-down movement space, so that the rigidity of the suspension can be designed to be smaller, the vibration frequency of the vehicle body is reduced, and the driving smoothness is improved. Fourthly, the driving wheel steering is easy to realize. The advantages enable the independent suspension to be widely applied to modern automobiles, particularly the independent suspension is commonly adopted by the steering wheel of the car, and in order to improve the driving safety, the independent suspension is also adopted by the rear suspension of more and more high-grade cars.

Currently, the most widely used independent suspensions on automobiles are mainly: a double-wishbone independent suspension, a macpherson independent suspension and a multi-link independent suspension. The double-wishbone independent suspension has the outstanding advantages of flexible design, but when the automobile wheel adopting the suspension jumps, the wheel positioning parameters and the wheel track change greatly, the straight-line driving capability of the automobile is reduced, the operation stability is poor, and meanwhile, the tire abrasion is serious. The Macpherson suspension has the advantages that the structure is simple, the space is saved, the wheel track, the toe-in, the wheel camber and other positioning parameters are not greatly changed in the wheel jumping process, the tire abrasion is reduced, the automobile has better operation stability, but the designability is poor, friction force exists between a piston rod and a guide sleeve of the shock absorber, the dynamic stiffness of the suspension is increased, the elastic characteristic is poor, and the influence is more obvious particularly in small displacement. The multi-connecting-rod independent suspension has the advantages that the change of wheel positioning parameters is small when the wheel jumps, but the design flexibility is poor, the multi-connecting-rod independent suspension is very sensitive to the structural parameters of the connecting rods, the requirement on processing and manufacturing precision is high, and the assembly and adjustment are difficult, so that the multi-connecting-rod independent suspension is mainly applied to medium and high-grade cars at present.

Although the conventional independent suspension can meet the design requirement of the suspension functionally, the wheel alignment parameters are changed when the wheel jumps. In practical applications, a large change in wheel alignment parameters may adversely affect the handling stability or other performance of the vehicle, for example, a change in the track width may cause a decrease in the straight-driving capability of the vehicle, and also cause an increase in the rolling resistance and an effect on the steering system; the change in camber angle causes abnormal wear of the tire.

How to ensure that the positioning parameters of the wheels are not changed when the wheels jump is a key point and a difficulty in the innovative design of the independent suspension structure. Universal group and the university of qinghua have jointly proposed three kinds of linear guide mechanisms that can be used for automotive suspensions, see [ 1. zhao seishan, wangjian yi. 200910085582.7, 2009-11-4. ] in [ 2. Guilin, Zhao Jingshan, Zhangjie, Liu Ding. CN201110215816.2, 2012-02-22., [ 3. zhangjie, zhao seoshi, zixian, wangjian. CN201110218599.2, 2012-02-22 ]. In the patent [ 1 ], the suspension branched chain is an RPR kinematic chain, which has good anisotropic stiffness, but the RPR kinematic chain has a moving pair, so that the sliding friction at the moving pair is large, and the RPR kinematic chain is not suitable for being used as a suspension guide mechanism; 【2】 The middle suspension branch chains are RRR kinematic chains, the rigidity of the middle suspension branch chains along the direction vertical to the plane determined by the RRR kinematic chains is poor, and a plurality of hinge kinematic pairs are provided; 【3】 The branched chains of the middle suspension are all elastic multi-connecting rods, the rigidity of a guide mechanism of the middle suspension along the longitudinal direction of the wheel is poor, and when the guide mechanism jumps up and down to the limit position, the elastic rods can generate movement mutation; and has high requirements on the elasticity, the strength and the toughness of the composite material of the guide rod. Therefore, the above 3 types of suspension guide rods are not highly practical and need to be continuously improved.

SUMMERY OF THE UTILITY MODEL

The utility model aims to solve the shortcoming of above-mentioned prior art, the utility model provides a can be used to the vice multi-link straight line translation formula suspension of adoption ball spline of car independent suspension system, realize the camber angle of wheel, king pin inclination and caster angle, control the wheel base, toe-in (toe-in) and the fore-and-aft axle base can remain unchanged all the time at the wheel in-process of beating from top to bottom, thereby improve the handling stability of car, ride comfort and the travelling comfort of taking, and can effectively reduce the wearing and tearing of tire. Meanwhile, on the premise of stronger implementability, the suspension mechanism can be ensured to have higher all-directional rigidity, and the loaded deformation is reduced as much as possible.

The utility model provides a technical scheme that its technical problem adopted: the multi-connecting-rod linear translation type suspension with the ball spline pair comprises a spring shock absorber system, a wheel, a vehicle body, a steering knuckle, an upper side first suspension branched chain, an upper side second suspension branched chain, a lower side first suspension branched chain and a lower side second suspension branched chain, wherein the spring shock absorber system is hinged with the steering knuckle and the vehicle body respectively, the steering knuckle is matched with the wheel through a hub unit, and two ends of the four suspension branched chains are hinged with the steering knuckle and the vehicle body respectively.

Preferably, the upper first suspension branch, the upper second suspension branch, the lower first suspension branch and the lower second suspension branch are all provided with ball spline pairs, and the ball spline pairs comprise a dust cover, a short connecting rod, a fixed pin, a buffer washer, a spline shaft, an oil hole screw, a flat key, a spline shaft sleeve, a retainer ring, a bolt and a long connecting rod. The short connecting rod and the spline shaft are in transition fit and are fixedly connected through a fixing pin, the spline shaft is matched with a spline shaft sleeve, a spline retaining ring is connected with the spline shaft through a bolt, a flat key is arranged on the spline shaft sleeve and is in transition fit with the long connecting rod, and a dust cover is further arranged on the suspension branched chain.

Preferably, the vertical planes on which the upper set of 2 suspension branches are located are not coplanar, the vertical planes on which the lower set of 2 suspension branches are located are also not coplanar, and the intersecting lines of the two sets of vertical planes are collinear or parallel.

Preferably, the vertical planes of the upper first suspension branched chain and the lower first suspension branched chain are coplanar, the vertical planes of the upper second suspension branched chain and the lower second suspension branched chain are coplanar, and the included angle between the two vertical planes is 90 degrees.

Preferably, the steering knuckle is provided with an upper first lug, an upper second lug, a lower first lug and a lower second lug, and is further provided with a spring damper connecting hole I, a spring damper connecting hole II, a brake caliper connecting hole I and a brake caliper connecting hole II.

The beneficial effect of utility model is: the positioning parameters of camber angle, caster angle and caster angle of the wheel, toe-in (toe-out) of the wheel, left and right wheel tracks, front and rear wheel base and the like can be kept unchanged all the time in the up-and-down jumping process of the wheel, so that the abrasion of the tire is effectively reduced, and the control stability, the driving smoothness and the riding comfort of the automobile can be effectively improved; the suspension branch chain is simple in structure, the ball spline pair can be replaced after being worn, and the service life of the suspension branch chain is prolonged.

Drawings

Fig. 1 is a schematic structural diagram of the present invention.

Fig. 2 is a schematic view of a suspension branch structure.

Fig. 3 is a schematic structural view of a knuckle.

Fig. 4 is a top view of the suspension system.

Figure 5 is an axial view of the suspension system along the x-axis.

Description of reference numerals: the suspension system comprises a spring damper system 1, a wheel 2, a vehicle body 3, a steering knuckle 4, an upper first suspension branched chain 5a, an upper second suspension branched chain 5b, a lower first suspension branched chain 6a, a lower second suspension branched chain 6b, a dust cover 7, a short link 8, a fixing pin 9, a buffer gasket 10, a spline shaft 11, an oil hole screw 12, a flat key 13, a spline shaft sleeve 14, a retainer ring 15, a bolt 16, a long connecting rod 17, a spring damper connecting hole I18 a, a spring damper connecting hole II 18b, a brake caliper connecting hole I19 a, a brake caliper connecting hole II 19b, a hub unit fixing shaft 20, an upper first lug 21a, an upper second lug 21b, a lower first lug 22a and a lower second lug 22 b.

Detailed Description

The present invention will be further explained with reference to the accompanying drawings:

example (b): as shown in fig. 1, the multi-link linearly translating suspension includes a wheel 2, a vehicle body 3, a spring damper system 1 and a knuckle 4. The steering knuckle 4 is connected with the wheel 2 through a hub unit, and the spring damper system 1 is respectively hinged with the steering knuckle 4 and the vehicle body 3. The system further comprises four suspension branch chains, namely an upper side first suspension branch chain 5a, an upper side second suspension branch chain 5b, a lower side first suspension branch chain 6a and a lower side second suspension branch chain 6b, wherein two ends of the four suspension branch chains are respectively hinged with the steering knuckle 4 and the vehicle body 3.

The suspension branches shown in fig. 2 each include a dust cover 7, a short link 8, a fixing pin 9, a cushion washer 10, a spline shaft 11, an oil hole screw 12, a flat key 13, a spline shaft sleeve 14, a retainer ring 15, a bolt 16, and a long link 17. The short connecting rod 8 and the spline shaft 11 are in transition fit and are connected through a fixing pin 9, so that the short connecting rod and the spline shaft are convenient to disassemble and assemble. The spline shaft 11 and the spline shaft sleeve 14 are matched, so that the suspension branched chain only has the freedom of expansion and contraction along the axial direction, and the ball spline pair is a standard part. The spline ring 15 is connected to the spline shaft 11 by bolts 16, and functions to prevent the spline shaft from being pulled out and the balls inside the spline shaft housing 14 from falling out. The spline shaft sleeve 14 and the long connecting rod 17 are in transition fit, and the flat key 13 can transmit large torque. The dust cover 7 is arranged on the suspension branch chain and has the functions of dust prevention, water prevention and corrosion prevention.

The over-constraint of the four suspension branch chains enables the suspension system to have only one degree of freedom, wherein the vertical planes where the four suspension branch chains are located are not coplanar, and the intersecting lines are collinear or parallel. In order to improve the configuration stability and the bearing capacity of the suspension mechanism, the vertical planes of the upper first suspension branched chain 5a and the lower first suspension branched chain 6a are coplanar, the vertical planes of the upper second suspension branched chain 5b and the lower second suspension branched chain 6b are coplanar, and the included angle between the two vertical planes is 90 degrees, as shown in fig. 4.

As shown in fig. 3, the knuckle 4 is provided with an upper first lug 21a, an upper second lug 21b, a lower first lug 22a and a lower second lug 22b, and the knuckle 4 is further provided with a spring damper connecting hole one 18a, a spring damper connecting hole two 18b, a brake caliper connecting hole one 19a and a brake caliper connecting hole two 19 b. The four support lugs are provided with suspension branch chain connecting holes, and the intersection line of two vertical planes determined by the suspension branch chain connecting hole axes of the two support lugs at the upper side and the intersection line of two vertical planes determined by the suspension branch chain connecting hole axes of the two support lugs at the lower side are overlapped or parallel.

The utility model provides a many connecting rods straight line translation formula suspension only has the degree of freedom that moves along the z axle and is decided by the mechanism characteristic of this suspension mechanism, just analyzes the mechanics motion characteristic of this suspension mechanism next.

Firstly, a corresponding coordinate system oxyz is established, the axis of a rotation pair at the joint of the upper first suspension branched chain 5a and the vehicle body is an x-axis, a y-axis is positioned in a vertical plane where the suspension branched chain is positioned along the horizontal direction, and a corresponding z-axis is positioned along the vertical direction, as shown in fig. 4 and 5. Provided with a suspension branch chain A₁B₁Has a length of l₁The angle between the axis of the branch chain of the suspension and the plane oxy isAccording to the theory of freedom analysis of robot mechanism [ M ] of Zhao Jing shan, Feng Jing, Zhu Fu Zi]Beijing: scientific publishing, 2009 ] proposed analysis theory of mechanism degrees of freedomCan write out the suspension branch chain A₁B₁The motion spiral system is as follows:

${\$}_{A_1{\mathrm{<figure-callout\; id="1"\; label="B"\; filenames="HDA0000157232600000011.png"\; state="\{\{state\}\}">B</figure-callout>}}_1}=\left[\begin{array}{ccc}{\$}_{A_1}& {\$}_{{\mathrm{<figure-callout\; id="1"\; label="P"\; filenames="HDA0000157232600000011.png"\; state="\{\{state\}\}">P</figure-callout>}}_1}& {\$}_{B_1}\end{array}\right]---\left(1\right)$

wherein, ${\$}_{A_1}={\left[\begin{array}{cccccc}1& 0& 0& 0& 0& 0\end{array}\right]}^T$

suspension branch chain A₁B₁Terminal constraint of

Can be derived from the reciprocal helix theory, i.e.

$^TE$^r=0（2）

Wherein $ is a moving screw system, $E=\left[\begin{array}{cc}0& I_3\\ I_3& 0\end{array}\right],$ $I_3=\left[\begin{array}{ccc}1& 0& 0\\ 0& 1& 0\\ 0& 0& 1\end{array}\right],$ $^ris a reverse helix system of $.

Explicit matrix

The conditions for rank reduction are:

if l₁Zero, then the revolute pair A₁And B₁Coincident, practically rotating pairs A₁And B₁Are misaligned so that the suspension branch A₁B₁Terminal constraint of

Can be obtained by the reciprocal helix theory. Can be obtained from the formula (2)

Comprises the following steps:

${\$}_{A_1{B}_1}^r={\left[\begin{array}{cccccc}1& 0& 0& 0& 0& 0\\ 0& 0& 0& 0& 1& 0\\ 0& 0& 0& 0& 0& 1\end{array}\right]}^T---\left(3\right)$

similarly, another suspension arm A can be written₂B₂The constraining helix of (a) is:

${\$}_{A_2{B}_2}^r={\left[\begin{array}{cccccc}0& 1& 0& 0& 0& 0\\ 0& 0& 0& 1& 0& 0\\ 0& 0& 0& 0& 0& 1\end{array}\right]}^T---\left(4\right)$

the steering knuckle 4 is therefore subject to the constraints:

${\$}_4^r=\left[\begin{array}{cc}{\$}_{A_1{B}_1}^r& {\$}_{A_2{B}_2}^r\end{array}\right]---\left(5\right)$

by substituting equation (5) into equation (2), the free motion of the knuckle 4 can be obtained as:

$₄=[0 0 0 0 0 1]^T（6）

equation (6) shows that the knuckle 4 has a free movement in translation along the z-axis direction, so that the knuckle 4 of the spatial multi-link linearly guided suspension mechanism can make a single degree of freedom fixed linear translation movement. Similarly, it can be found that the knuckle has only free motion in translation along the z-axis direction under the constraint of the four suspension branches. Therefore, the spatial multi-link straight guide suspension mechanism can keep parameters such as camber angle, caster angle and caster angle of the wheel connected with the knuckle 4, wheel track and wheel base constant during the wheel jump. Therefore, the abrasion of the tires can be reduced to the maximum extent, and the operation stability, the driving smoothness and the riding comfort of the automobile are improved. Meanwhile, as the standard part ball spline pair is adopted, the suspension branch chain has a simple structure and a simple processing technology; the over-constraint of the four suspension branch chains enhances the bearing capacity of the suspension mechanism.

Since the suspension system has only one degree of freedom of movement along the z-axis, revolute pair B₁The distance from the x-axis in the y-axis direction is constant during suspension bounce, and is set to L, as shown in fig. 5, then

When the suspension is supposed to be positioned at the upper and lower travel limits, the corresponding included angles are respectively

And

the stroke of the suspension and the length change of the branch chain of the suspension are respectively as follows:

therefore, the utility model provides an adopt vice many connecting rods straight line translation formula suspension of ball spline can carry out suspension mechanism stroke and corresponding other structural parameter designs according to the suspension system design requirement of reality. Compared with other known suspension mechanisms, the suspension mechanism can ensure that the wheel positioning parameters are not changed in the wheel jumping process, has large rigidity in all directions and simple structural design, and further improves the operation stability, the driving smoothness and the riding comfort of the automobile.

In addition to the above embodiments, the present invention may have other embodiments. All the technical solutions formed by adopting equivalent substitutions or equivalent transformations fall within the protection scope claimed by the present invention.

Claims (7)

1. The utility model provides an adopt vice multi-link straight line translation formula suspension of ball spline, includes spring damper system (1), wheel (2), automobile body (3) and knuckle (4) to and first suspension branch chain (5 a) of upside, second suspension branch chain (5 b) of upside and first suspension branch chain (6 a) of downside, second suspension branch chain (6 b) of downside, characterized by: the spring shock absorber system (1) is respectively hinged with the steering knuckle (4) and the vehicle body (3), the steering knuckle (4) is matched with the wheel (2) through the hub unit, and two ends of four suspension branch chains (5 a, 5b, 6a and 6 b) are respectively hinged with the steering knuckle (4) and the vehicle body (3).

2. The multi-link linear translatory suspension of claim 1 employing ball spline pairs wherein: the structure comprises a dust cover (7), a short connecting rod (8), a fixing pin (9), a buffer washer (10), a spline shaft (11), an oil hole screw (12), a flat key (13), a spline shaft sleeve (14), a retainer ring (15), a bolt (16) and a long connecting rod (17).

3. The multi-link linear translatory suspension of claim 2 employing ball spline pairs wherein: short connecting rod (8) and integral key shaft (11) adopt transition fit to through fixed pin (9) fixed connection, integral key shaft (11) and spline shaft sleeve (14) cooperation, spline retaining ring (15) are connected with integral key shaft (11) through bolt (16), are equipped with flat key (13) on spline shaft sleeve (14) and adopt transition fit with long connecting rod (17), still are equipped with dust cover (7) on the suspension branch chain.

4. The multi-link linear translatory suspension of claim 1 employing ball spline pairs wherein: the vertical planes of the upper group of 2 suspension branched chains (5 a, 5 b) are not coplanar, the vertical planes of the lower group of 2 suspension branched chains (6 a, 6 b) are also not coplanar, and the intersecting lines of the two groups of vertical planes are collinear or parallel.

5. The multi-link linear translatory suspension of claim 1 employing ball spline pairs wherein: the vertical planes of the upper first suspension branched chain (5 a) and the lower first suspension branched chain (6 a) are coplanar, the vertical planes of the upper second suspension branched chain (5 b) and the lower second suspension branched chain (6 b) are coplanar, and the included angle between the two vertical planes is 90 degrees.

6. The multi-link linear translatory suspension of claim 1 employing ball spline pairs wherein: the steering knuckle (4) is provided with an upper first support lug (21 a), an upper second support lug (21 b), a lower first support lug (22 a) and a lower second support lug (22 b), and the steering knuckle (4) is further provided with a spring damper connecting hole I (18 a), a spring damper connecting hole II (18 b), a brake caliper connecting hole I (19 a) and a brake caliper connecting hole II (19 b).

7. The multi-link linear translatory suspension of claim 6 employing ball spline pairs wherein: suspension branch connecting holes are formed in the four support lugs (21 a, 21b, 22a and 22 b), and the intersection line of two vertical planes determined by the suspension branch connecting hole axes of the upper two support lugs (21 a and 21 b) and the intersection line of two vertical planes determined by the suspension branch connecting hole axes of the lower two support lugs (22 a and 22 b) are overlapped or parallel.

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