RU2225796C2 - Independent suspension of vehicle steerable wheels - Google Patents

Abstract

FIELD: transport engineering; passenger cars. SUBSTANCE: proposed suspension contains steering knuckles hinge-coupled with car body by lower wishbone and longitudinal leaf spring coupled by ends with car body. Plane of spring leaves in place of its fastening to guide strut can be arranged square to longitudinal axis of strut. Spring can be hinge coupled by its central part either directly with wheel steering knuckle, or with damper housing made in form of Macpherson strut with rigid coupling with wheel steering knuckle, axes of hinge coupling lying on longitudinal axis of shock absorbing strut. This can be provided by making hole in central part of spring through which rod of shock absorbing strut passes, spring and shock absorbing strut being coupled by means of thrust bearing. Damper can coupled car body with lower wishbone of suspension. Hinge coupling of spring with steering knuckle or with damper housing can be made in form of ball support. Spring proper can be made single-leaf and/or of plastic materials. EFFECT: improved convenience of arrangement of suspension, prevention of transmission of forces from opposite wheels through spring, reduced longitudinal pliability of spring. 7 cl, 4 dwg

Description

 The invention relates to the field of transport engineering and is intended for use primarily in cars.

The MacPherson independent suspension ("candle" suspension) is widely known with a lower wishbone and an attachment point replacing the upper arm on a car body in the form of a guide rack ([1], p.240) - shock absorber ([1], p.275- 277, Fig. 6.47) or spring ([1], p.263-268, Fig. 6.35 and 6.39). In the first case, the body of the damping element (cylindrical shock absorber) is rigidly connected to the steering knuckle (rack) of the wheel, and its stem is connected to the car body (usually, to the wing splash shield), while the elastic element (spring, torsion, leaf spring) is connected with lower lever.

In the second case, the elastic element (coil spring), covering the telescopic shock absorber, is installed between its body and the area of its rod on the body. This design option is the closest to the claimed. The main advantage of the spring strut guide is that all parts performing elastic work and guiding functions can be combined into one mounting unit. The main drawback of the suspension with a spring guide strut is the contradiction associated with providing the most favorable kinematics of the wheel movement, which is determined by the relative position of the elements (lateral tilt of the strut, spring displacement, etc.), and with geometric restrictions (break-in shoulder, tire width and etc.). In particular, for the installation of wide tires, the middle part of the body of the damping element (shock absorber) is forced to be “pressed in” ([1], p.242-243, Fig. 6.3). The main limiting factor is the spring, which limits the engine compartment in the upper zone and increases the height of the front end of the car, which, in particular, adversely affects aerodynamics. In addition, the "point" mount of the shock absorber rod (upper support) creates a concentration of loads on the car body, which necessitates the strengthening of this site.

An independent front suspension of the vehicle’s steered wheels is also known, containing a transverse leaf spring, while the wheel strut with its lower part is pivotally connected to the body by a transverse lever, and the upper part - with the end of the spring and a damping element - a telescopic shock absorber ([2], p.188 and 189, Fig. 3.4.19a). Such a suspension is simple and cost-effective, since the spring perceives the action of loading forces in all directions and therefore can replace two levers and springs. However, with such a design, the layout is complicated, since it is necessary to pass the spring through the space occupied by the power unit, which, in particular, leads to an increase in the height of the hood and deterioration of the aerodynamics of the car. In addition, the transverse spring has increased longitudinal flexibility, and through it the forces are transmitted from one wheel to another (which negatively affects their kinematics, especially with unlike wheel travel).

The technical result of the invention consists in increasing the convenience of the suspension arrangement, eliminating the transmission of forces through the spring from the opposite wheels, and also in reducing the longitudinal flexibility of the spring.

The technical result is achieved by the fact that in the known suspension of steered wheels with an elastic element in the form of a spring and fastening to it the upper support of the steering knuckle of the wheel, the spring is made longitudinal, with its middle part pivotally connected to the steering knuckle of the wheel, and the ends with the car body, and the plane spring sheets in the place of its attachment to the guide rack can be placed perpendicular to the longitudinal axis of the rack. The spring with its ends can be connected to the car body by means of elastic supports, and its central part is pivotally connected either directly to the steering knuckle of the wheel or to the body of the damping element, made in the form of a MacPherson strut with a rigid connection with the steering knuckle of the wheel, while the axis of the hinge ties lie on the longitudinal axis of the MacPherson strut. This can be achieved by making a hole in the central part of the spring through which the rod of the MacPherson strut absorber passes, while the spring and the MacPherson strut are interconnected by means of a thrust bearing.

In addition, the damping element can connect the car body with the lower suspension arm, the articulation of the spring with the steering knuckle or the body of the damping element can be made in the form of a ball bearing, and the spring itself can be made of single-sheet and / or plastic materials.

The execution of the elastic element in the form of a longitudinal leaf spring pivotally connected to the steering knuckle of the wheel makes it possible to improve the suspension properties by using the guiding properties of the longitudinal spring, isolate the loads transmitted from the wheels from each other, and "carry" the latter along the vehicle body (to the points of attachment of the spring ends) .

The placement of the leaf spring perpendicular to the longitudinal axis of the guide rack provides a more efficient operation of the spring (there are no tangential loads).

The connection of the springs with their ends with the car body by means of elastic supports, and with its central part - articulated with a rotary cam of the wheel, provides shock absorption of the loads transmitted to the body and the possibility of turning the wheel.

The hinged connection of the central part of the spring with the housing of the damping element, made in the form of a MacPherson strut with a rotary cam of the wheel and the placement of the pivot axis on the longitudinal axis of the MacPherson strut, provides "kinematic isolation" of the suspension and steering operation.

Making a hole in the central part of the spring through which the MacPherson strut rod passes and connecting the latter with the spring by means of a thrust bearing provides effective unloading of the shock absorber rod from lateral forces.

The connection of the damping element with the lower suspension arm allows simplifying the mounting of the spring with the steering knuckle of the wheel and ensures a minimum suspension height.

Performing a hinge connection between the spring and the knuckle or housing of the damping element in the form of a ball bearing provides the most effective perception of multidirectional loads from the suspension.

The implementation of single-leaf springs and / or from plastic materials simplifies the design and allows you to get the shape of the spring necessary for a particular layout.

The proposed technical solution is illustrated by the following graphic materials: figure 1 shows a General view of the suspension (front view); figure 2 is the same side view; figure 3 is an embodiment with a slope of the spring (front view); figure 4 is a design variant.

The suspension comprises a lower wishbone 1 pivotally connected to a rotary fist 2 of the wheel 3. The fist 2 is rigidly connected to the housing 4 of the telescopic shock absorber (damping element), the rod 5 of which, in turn, is connected to the car body 7 by means of a support 6. The housing 4 of the telescopic shock absorber is pivotally connected to the longitudinally arranged spring 8 by means of a thrust bearing 9. The leaves of the spring 8 can be oriented perpendicular to the longitudinal axis of the guide (shock absorber) of the stoic 4 (Fig. 3), and the spring 8 itself can be made semi-elliptical with fixed mounting of the ends of the spring in elastic (rubber) supports 10 (figure 2). If necessary, the maximum reduction in vehicle height and the use of small diameter wheels, the spring 8 is directly connected to the knuckle 2 by means of a ball bearing 12 (Fig. 4). At the same time, the damping element (hydraulic shock absorber) 4 is also shifted down and connects the car body 7 with the lower wishbone 1 of the suspension.

Suspension works as follows. When moving through bumps, the wheel 3 moves in a vertical plane, transmitting the impulse directly with its rotary fist 2 or the housing 4 of the shock absorber through the thrust bearing 9 or the ball bearing 12 to the spring 8, absorbing the dynamic load. The vibrations arising in this case are smoothed out by a damping element (hydraulic shock absorber) 4, which in this case can act as a guide upper arm. Thanks to the thrust bearing 9 or the ball bearing 12 during vertical movements of the wheel 3 provides the possibility of rotation.

Thus, the proposed solution provides a rational placement of suspension elements, facilitating the layout of the vehicle components, and also improves the suspension performance.

Sources of information:

1. Raimpel J. Car chassis. Suspension Designs. - M.: Mechanical Engineering, 1989.

2. Raimpel J. Car chassis. M .: Engineering, 1983.

Claims (7)

1. An independent suspension of the steered wheels of the vehicle, comprising a rotary cam of the wheel pivotally connected to the body by a lower wishbone and by means of a leaf spring, as well as a damping element, characterized in that the leaf spring is longitudinally and centrally pivotally connected to the rotary cam of the wheel, and ends - with a car body. 2. The suspension according to claim 1, characterized in that the spring with its central part is pivotally connected to the housing of the damping element, made in the form of a guide of the shock absorber strut with a rigid connection of its housing with a rotary cam of the wheel and articulated connection of its rod with the body, while the axis of the articulated ties lie on the longitudinal axis of the shock absorber strut guide. 3. Suspension according to claims 1 and 2, characterized in that the plane of the leaf sheets in the place of its attachment to the guide rack is placed perpendicular to the longitudinal axis of the rack. 4. The suspension according to claim 3, characterized in that a hole is made in the central part of the spring through which the rod of the shock absorber strut passes, while the spring and the shock absorber guide are interconnected by means of a thrust bearing. 5. The suspension according to claim 1, characterized in that the damping element connects the car body with the lower suspension arm. 6. Suspension according to claims 1, 2 and 5, characterized in that the articulated connection of the spring with the knuckle is made in the form of a ball bearing. 7. Suspension according to claims 1-6, characterized in that the spring is made univalent and / or from plastic materials.

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