JP4704138B2 - Vehicle suspension - Google Patents

Description

  The present invention relates to a double wishbone type vehicle suspension.

  In recent years, in vehicle suspensions, double wishbone suspensions that have a high degree of freedom in design, such as geometry changes and compliance tuning, have been adopted not only for the front but also for the rear, in order to achieve higher levels of ride comfort and handling stability. Tend to be widely adopted.

In this type of double wishbone type suspension, as a technique for realizing a change in geometry according to the running state of a vehicle, for example, in Patent Document 1, a ball joint is provided at an intermediate portion of one arm portion of an upper arm. Enables bending and connects the other end of the connecting arm, one end of which is connected to the arm near the ball joint, offset to the kingpin axis of the knuckle arm, and the actual arm length (camber angle) of the upper arm according to the vertical stroke A technique for making the variable variable is disclosed.
JP 7-257125 A

  By the way, in the double wishbone type suspension, the shock absorber operates in a three-dimensionally complicated manner due to the complicated link operation and the like. For this reason, during the vertical stroke of the suspension, the stress in the twisting direction can be easily input to the shock absorber.

  When the stress in the twisting direction is input to the shock absorber, the top mount is twisted, the elastic body becomes non-linear characteristics, the bound rigidity is increased, and the damping function of road surface vibration transmitted to the vehicle body via the suspension There is a problem that the original function required for the system cannot be obtained. Here, “twisting” means that the rubber between the inner and outer cylinders is in a complex strain state due to shearing and twisting by relative rotation and relative inclination between the inner and outer cylinders such as the top mount.

  In addition, if excessive stress in the direction of twisting is input to the shock absorber, it may cause a decrease in fatigue strength of the rod or the like.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a vehicle suspension that can suppress shock absorber twisting and improve road vibration damping function and fatigue strength.

The present invention allows an upper arm whose inner end portion is connected to the vehicle body while allowing the outer end side to swing in the vertical direction, and allows the inner end portion to be connected to the vehicle body while allowing the outer end side to swing in the vertical direction. A lateral link, a hub carrier in which the outer end portion of the upper arm and the outer end portion of the lateral link are connected to each other vertically, an upper end portion is fixed to the vehicle body via a top mount, and a lower end portion is the lateral link. A shock absorber that is connected to the vehicle, a trailing link that allows the outer end to be pivoted in the vertical direction and the inner end to be connected to the vehicle body, and the outer end is connected to the lower portion of the hub carrier , and the outer end side. A double wishbone type vehicle suspension having an inner end connected to the vehicle body and a toe control link connected to the hub carrier on the outer end side while allowing vertical swinging of the vehicle There are, in a side view in the static state, the intersection of the first virtual line and the axis of the trailing link through the outer end portion and parallel to the swing axis of the inner end of the upper arm of the upper arm, The axis of the shock absorber is substantially orthogonal to a second imaginary line passing through the outer end of the lateral link.

  According to the vehicle suspension of the present invention, the shock absorber can be prevented from being twisted, and the road surface vibration damping function and fatigue strength can be improved.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. The drawings relate to an embodiment of the present invention, FIG. 1 is a bottom view showing the suspension structure on the left side of the rear part of the vehicle body, FIG. 2 is a side view showing the suspension structure on the left side of the rear part of the vehicle body, and FIG. FIG. 4 is a cross-sectional view of the main part of the top mount of the shock absorber.

  1 and 2, reference numeral 1 denotes a vehicle body, and reference numeral 2 denotes a sub-frame fixed to the lower part of the left and right main frames 1 a extending in the front-rear direction of the vehicle body 1. The subframe 2 has a front subframe portion 3 and a rear subframe portion 4 extending in the vehicle width direction, and a pair of left and right vertical frame portions 5 that connect the frame portions 3 and 4 back and forth. The part is composed. In addition, elastic bushes 6 and 7 are fixed to the left and right end portions of the sub-frame portions 3 and 4, respectively. The frame portions 3 and 4 are connected to the left and right main frames via the elastic bushes 6 and 7, respectively. It is installed in 1a.

  A pair of front and rear brackets 10 and 11 are fixed on the upper surface of the vertical frame portion 5, and each bracket 10 and 11 has a fixed end portion (inner end portion) of the upper arm 12 having a bifurcated structure on the fixed end side. 12a and 12b are pivotally supported via elastic bushings 13 and 14, respectively. As a result, the upper arm 12 has its free end side (outer end side) oriented outward from the vehicle body 1 and is swingable in the vertical direction. Further, the free end portion (outer end portion) 12 c of the upper arm 12 is pivotally supported on the upper portion of the hub carrier 17 connected to the rear drive axle 16.

  A bracket 20 is integrally formed in the middle of the rear sub-frame portion 4 in the vicinity of the connection portion with the vertical frame portion 5, and the bracket 20 has a fixed end portion (inner end portion) 21 a of the lateral link 21. Are supported in an integral manner via an elastic bush 23. As a result, the lateral links 21 and 22 have their free end sides (outer end sides) oriented outward from the vehicle body 1 and are swingable in the vertical direction. Further, a free end portion (outer end portion) 21 b of the lateral link 21 is pivotally supported at the lower portion of the hub carrier 17, and a lower end portion 25 a of a shock absorber 25 is pivotally supported in the middle of the lateral link 21. Yes.

  Here, as shown in FIGS. 2 and 3, a top mount 26 is connected to an upper portion of the shock absorber 25, and an upper end portion of the shock absorber 25 is fixed to the vehicle body 1 through the top mount 26. Yes. As shown in FIG. 4, the top mount 26 includes an inner cylinder 26a fixed to the upper part of the shock absorber 25, an outer cylinder 26b fastened and fixed to the vehicle body 1 on the outer peripheral side of the inner cylinder 26a, and an inner cylinder 26a. And a mounting rubber 26c interposed between the outer cylinders 26b. Further, the mount rubber 26c is formed with a stopper 26d for preventing contact interference between the inner cylinder 26a and the outer cylinder 26b at the time of bounding or rebounding.

  A bracket 30 is fixed to the end of the front sub-frame portion 3 adjacent to the elastic bush 6, and a fixed end (inner end) 31 a of the trailing link 31 is attached to the bracket 30. The shaft is supported via an elastic bush 32. As a result, the trailing link 31 has its free end side (outside end side) oriented toward the outside of the rear portion of the vehicle body 1 and is swingable in the vertical direction. Further, the free end portion (outer end portion) 31 b of the trailing link 31 is axially supported by the lower portion of the hub carrier 17 via the elastic bush 33 in front of the lateral link 21.

  A bracket 35 is fixed to the lower surface of the vertical frame portion 5, and a fixed end (inner end) 36 a of a toe control link 36 is pivotally supported on the bracket 35 via an elastic bush 37. ing. Thereby, the free end side (outer end side) of the toe control link 36 is directed to the outside of the vehicle body 1 and is swingable in the vertical direction. Further, the free end portion (outer end portion) 36 b of the toe control link 36 is pivotally supported via an elastic bush 38 on an arm portion 17 a extending forward from the hub carrier 17.

  Thus, in the present embodiment, a double wishbone rear suspension is formed at the rear portion of the vehicle body 1. As shown in FIG. 3, the layout of each member constituting the suspension passes through the outer end portion 12 c of the upper arm 12 and the inner end of the upper arm 12 in a side view when the vehicle is stationary (when the vehicle is stopped or cruising). Second imaginary line d passing through the intersection point o between the first imaginary line b parallel to the swing axis a of the portions 12a and 12b and the axis c of the trailing link 31 and the outer end 21b of the lateral link 21. In addition, the layout is set so that the axis e of the shock absorber 25 is substantially orthogonal. That is, each member is attached to the inner end portion and the outer end portion so that the angle θ formed by the second imaginary line d and the axis line e of the shock absorber 25 is approximately 90 ° in a side view in a static state. Etc. are set.

  According to such a configuration, the angle θ formed by the second imaginary line d and the axis e of the shock absorber 25 is set to approximately 90 °, thereby acting on the shock absorber 25 in a side view during the vertical stroke of the suspension. The two-dimensional twist angle can be suppressed. As a result, the final three-dimensional twist angle acting on the shock absorber 25 can be easily suppressed, the mount rubber 26c of the top mount 26 becomes non-linear characteristics, and the road vibration damping function is reduced. It is possible to effectively suppress the occurrence of defects.

  In particular, the stopper 26d formed on the mount rubber 26c of the top mount 26 can accurately suppress early interference due to twisting, and the feeling of hardness of the top mount 26 in a large stroke can be reduced. Accordingly, even when the axial spring of the shock absorber 25 is set to be hard so as to enhance the damper damping force in a small stroke, a good damping function can be realized over a wide range from a small stroke to a large stroke. .

  Moreover, since it can suppress that the stress of the excessive twist direction is input into the shock absorber 25, fatigue strength, such as a rod, can be improved.

Bottom view showing the suspension structure on the left side of the rear of the vehicle Side view showing the suspension structure on the left side of the rear of the vehicle Explanatory drawing which shows the positional relationship of each part which comprises a suspension Cross-sectional view of the main part of the shock absorber top mount

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Car body 1a ... Main frame 2 ... Sub-frame 3 ... Front sub-frame part 4 ... Rear sub-frame part 5 ... Vertical frame part 12 ... Upper arm 12a, 12b ... Inner end part 12c ... Outer end part 17 ... Hub carrier 21 ... Lateral Link 21b ... Outer end 25 ... Shock absorber 25a ... Lower end 26 ... Top mount 31 ... Trailing link a ... Oscillating axis b ... First imaginary line c ... Trailing link axis d ... Second imaginary line e … Shock absorber axis o… intersection

Claims (1)

An upper arm in which the inner end is connected to the vehicle body while allowing the outer end to swing in the vertical direction;
A lateral link that allows the outer end to swing in the vertical direction and the inner end is connected to the vehicle body;
A hub carrier in which the outer end portion of the upper arm and the outer end portion of the lateral link are respectively connected vertically.
A shock absorber having an upper end fixed to the vehicle body via a top mount and a lower end connected to the lateral link;
A trailing link that allows the outer end side to swing in the vertical direction and the inner end portion is connected to the vehicle body, and the outer end side is connected to the lower portion of the hub carrier ;
This is a double wishbone type vehicle suspension having an inner end connected to the vehicle body while allowing the outer end to swing in the vertical direction, and a toe control link connected to the hub carrier on the outer end. And
In a side view in a static state, an intersection of a first imaginary line passing through the outer end of the upper arm and parallel to the swing axis of the inner end of the upper arm and the axis of the trailing link, and the lateral link A suspension for a vehicle, wherein an axis of the shock absorber is substantially orthogonal to a second imaginary line passing through an outer end of the vehicle.

Images