JPH03279010A - Suspension for vehicle - Google Patents

Abstract

PURPOSE:To increase the turning stability of a vehicle by applying the constitution wherein the ends of upper and lower arms at the side of a wheel are kept near each other, one of the aforesaid arms at the side of a body is connected to the body via a turning link and this turning link is connected to the other arm with a control link, respectively in the suspension device of double wishbone type or the like. CONSTITUTION:A bracket 20 of approximately triangular form as a turning link is fitted to a suspension member 13 at the side of a wheel. In addition, an upper arm 23 at the side of a body is con nected to the upper apex of the bracket 20 via a rubber bush 22. Also, a control link 25 is connected to the lower apex via a rubber bush 24, and the other end thereof is connected to a lower arm 29 via a rubber bush 31. The lower arm 29 at the side of the body is connected to the suspension member 13. Furthermore, the ends of the lower arm 29 and upper arm 23 at the side of the wheel are so positioned as to be tensioned toward each other and respectively connected to a wheel knuckle. According to the aforesaid construction, the turning stability of a vehicle is improved.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a vehicle suspension, and in particular, a double wishbone type suspension in which at least an upper link and a lower link are swingably interposed between a vehicle body and wheels. , relates to vehicle suspensions such as multi-link types.

[Conventional technology]

Conventionally, as this type of vehicle suspension, one having the configuration shown in FIG. 6 is known. This suspension is of the double wishbone type, and in the figure,
1 is a wheel, 2 is a vehicle body, and 3 is a suspension member provided on the vehicle body 2.

An upper arm 4. is located between the knuckle (not shown) on the wheel 1 side and the suspension member 3. A lower arm 5 is provided, the end of each arm 4, 5 on the wheel side is connected to the knuckle via a ball joint 6, and the end on the vehicle body side is connected to the suspension member 3 via a rubber bush 7. ing.

As is well known, in such a suspension structure, the roll center height is determined by the height of the upper arm 4. A line segment (
The height from the road surface of the point RC (roll center) where the swing arm) intersects with the vehicle body center line is obtained as tc (see Automotive Technology Extra Line "New Automotive Engineering Handbook" published in 1978).

[Problem to be solved by the invention]

In the above-mentioned suspension structure shown in Fig. 6, the installation of both arms 4.5 is as follows when viewed from the longitudinal direction of the vehicle:
Since the slope narrows toward the inside of the vehicle, when the vehicle bounces, the projected length of the upper arm 4 in the vehicle width direction (hereinafter referred to as the lateral length) becomes smaller than the initial state, as shown in FIG. 7(a). Since the lateral length of the lower arm 5 becomes longer, the camber angle of the wheel 1 changes in the negative direction.

However, since the instantaneous rotation center IC of the wheel is located on the inside of the vehicle, when turning with high lateral acceleration (G) as shown in Fig. 8(a), the cornering force CF of the outer wheel
The amount of load movement acting upward due to z “ΔWoat =
CF t ・tan θ2" is the load movement amount "-
ΔJ, = CF I-tanθ1” becomes larger (
During a high-G turn, cF < CFz), the overall jerk increases.

Therefore, if the longitudinal shape of both arms 4.5 in FIG. 6 is set at an angle that narrows toward the outside of the vehicle as shown in FIG. It is located on the outside, so that the roll center RC is formed below the ground. In other words, this situation is opposite to the case shown in Fig. 8(a), and during a high-G turn, the downward load movement amount "-ΔW" due to the cornering force CF of the outer wheel
oat=CF! ian θ2” is the amount of load movement acting upward due to the cornering force CFI of the inner race.
Δw,fi=CF r ·tan θ,'', resulting in an overall jerk down.

However, in the case of such a bounce, Figure 7 (b)
As shown in , the lateral length of the upper arm 4 becomes longer than the initial state, and the lateral length of the lower arm 5 conversely becomes shorter, so the camber angle of the wheel 1 changes in the positive direction.

In this way, with the conventional suspension structure shown in Fig. 6, it is not possible to obtain a negative ground balance angle and jack down at the same time during high-G turns, so it is difficult to achieve high running stability during high-G turns. However, there has been a problem in that it has not been possible to fully meet the demand.

The present invention has been made by focusing on such problems with conventional suspensions, and its object is to make the camber angle of the outer wheel negative to the ground during high G turns, and to reduce the effect of jacking down the vehicle. The objective is to improve the turning stability.

[Means to solve the problem]

In order to solve the above problems, the present invention provides a vehicle suspension having an upper link and a lower link that are swingably interposed between a vehicle body side member and each wheel. Both links are arranged so that both links narrow toward the outside of the vehicle when viewed, and the vehicle body side end of one of the upper link and the lower link is swingably supported, and the vehicle body side member and a control link that connects the other link to a mounting position closer to the wheel than the predetermined mounting position of the swing link.

[Effect]

In the present invention, the instantaneous center of rotation of the wheel formed by the upper link and the lower link is located on the outside of the vehicle opposite to its own wheel, and as a result, the roll center is located below the road surface, and the bounce state during high G turns Then you will get a jatsuki down effect.

At the same time, when turning, the control link urges the connection point with the rotation link upward as both links swing upward of the vehicle. As a result, the rotation link is rotated around the mounting position with the vehicle body side member, and as a result,
The upper link is pulled into the inside of the vehicle (if one link is the upper link) or the lower link is pushed out to the outside of the vehicle (if one of the links is the lower link), and the camber angle of the outer wheel relative to the ground becomes negative.

In this way, in a high turning state, the jacking down effect and the negative camber of the outer wheel are simultaneously ensured, and turning stability is significantly improved.

〔Example] Embodiments of the present invention will be described below with reference to the drawings.

(First example) A first embodiment is shown in FIGS. 1 to 3.

FIGS. 1 and 2 show the configuration of a vehicle having double wishbone type suspensions for both the front and rear wheels, as viewed from the rear side.

In the figure, 11L and 11R are the rear left and rear right wheels.

Reference numeral 12 indicates a vehicle body, and reference numeral 13 indicates a suspension member as a vehicle body side member fixedly installed on the vehicle body 12 side.

The suspension member 13 has an upper pivot position (an attachment point on the wheel side) U at a predetermined position above both sides in the vehicle width direction.
are respectively set, and lower pivot positions are respectively set at predetermined positions below the attachment point U. Brackets 20 as rotation links are attached to the sides of the suspension members 13 facing the wheels. As shown in the figure, the bracket 20 is formed into a substantially triangular shape when viewed from the longitudinal direction of the vehicle, and one vertex of the bracket is connected to the upper pivot position U of the suspension member 13 via a rubber bushing 21, so that the bracket 20 It is rotatable around the central axis of the rubber bush 21.

Of the remaining two apexes of the bracket 20, the upper apex is connected to the vehicle body side end of an upper arm 23 as an upper link via a rubber bush 22.
The lower apex portion is connected to a control link 25 via a rubber bush 24. The wheel side end of the upper arm 23 is attached to the upper end of a knuckle (not shown) via a ball joint 26.

On the other hand, the vehicle body side end of a lower arm 29 as a lower link is attached to each of the lower pivot positions L of the suspension member 13 via rubber bushings 28, and the wheel side end of this lower arm 29 is attached to the lower end of the knuckle. It is attached to the section via a pole joint 30.

Furthermore, each lower arm 29 has a locking position M set at a predetermined intermediate position inside the vehicle body from the position of the rubber bush 24 of the bracket 20 when viewed from the vehicle longitudinal direction.

Then, the other end of the control arm 25 mentioned above is at the stop position 111M, and the lower arm 29 is connected via the rubber bush 31.
is connected to.

Here, when the above-mentioned configuration is viewed from the longitudinal direction of the vehicle when traveling straight on flat ground, the position of the rubber bush 24 of each bracket 20 is positioned to be further outward from the vehicle body than the position of the rubber bush 22, and the position of the rubber bush 22 is It is positioned further outward from the vehicle body than the upper pivot position U). Furthermore, each upper arm 23 is positioned lower on the wheel side than on the vehicle body side, so that when viewed from the front and rear directions of the vehicle, both arms 23 and 29 narrow toward the outside of the vehicle body as shown in the figure. It has a shape.

Note that the front wheel side also has the same configuration as described above.Next, the operation of the first embodiment will be explained.

Assume that you are currently traveling straight at a constant speed on a good road. In this state, although there is no inertial force acting on the car body and no upper or lower blades, the car body is held almost flat, and the relative distances between the left and right sprung tops and bottoms are kept the same, and the arms 23 and 29 shown in FIG. It forms the slope of In other words, since the upper arm 23 and the lower arm 29 have a shape that narrows closer to each other as they approach the wheel, the instantaneous center of rotation is formed by virtually extending the swing axes of both arms 23 and 29. The ICs are formed on the outside of the vehicle facing the own wheels 11L and IIR, respectively.

Therefore, the height h of the roll center RC is Hl', +=
-h0 (the area below the road surface is taken as negative).

Assume that the vehicle shifts from straight-ahead driving to cornering driving with high lateral acceleration. As a result, the vehicle body 12 has a roll angle corresponding to the acting inertia force F and the roll stiffness, for example, the vehicle body 12 on the left wheel 11L side.
2 sinks and the vehicle body 12 rises on the right wheel 11R side, resulting in a rolling state. In the process of reaching this rolling state, the upper arm 23 and lower arm 29 tend to displace upward within a predetermined swing plane as the vehicle body sinks on the outer wheel 11L side (that is, the outer wheel 11L bounces relatively), and the inner wheel As the vehicle body lifts up on the 11R side (that is, relatively, rebound of the inner ring 11R), the upper arm 23 and the lower arm 29 tend to displace downward within a predetermined swing plane.

Therefore, on the outer wheel ILL side, as shown in FIG. 2, the upper side of the suspension member 13 and the pot position U are lowered and the control link 25 is urged upward, so that the rotation link 20 moves from the pivot position U. Arrow R in the same figure
It rotates clockwise (as seen from the rear of the vehicle) as shown in the figure. As a result, the upper arm 23 is pulled closer to the center of the vehicle, so that the ground camber angle of the outer wheel 11L is adjusted to the third position.
As shown in the figure, it changes in the negative direction. On the other hand, inner circle 1
On the 1R side, the rotation link 2 is
0 is rotated clockwise, the upper arm 23 is allowed to move outward from the vehicle body, and the ground camber angle of the inner ring 11R changes in the positive direction as shown in FIG.

In this rolling state, the instantaneous rotation centers I C, ..., I Cin of the outer and inner wheels are both the same as the own wheel 1.
Since it is located on the outside of the vehicle facing 1L and 11R, it is the outer wheel side roll center RC. , (the height is -h,,t) and the inner wheel side roll center RCz- (the height is -h1) are both below the road surface. Here, )Lout l > l
htRl. Therefore, the amount of load movement ΔW between the inner and outer rings
i 11 + ΔW,, t (arm reaction bone) is the cornering force CF on the outer ring 11L side, as described above, - ΔWout = CFz ・tanθ2 Inner ring 11
On the R side, the cornering force CF is ΔWi, = CFI ・tan θ.

As the turning state becomes high G, that is, as the skid limit approaches, especially CFt>CFt and θ2>θ
, the influence of the outer wheel cornering force CF t on the jacking down becomes large, and the downward force "-Δ
When Woat J exceeds the upward force ΔW in J, a jack-down effect is obtained.

In this way, in the first embodiment, in a high G turning state,
The outer wheel's ground camber angle changes negatively or becomes more negative, and it also provides the effect of jacking down the vehicle body, so turning stability is significantly improved compared to the conventional case where only one or the other can be obtained. improves.

(Second Embodiment) Next, a second embodiment will be described based on FIGS. 4 and 5. Here, the same reference numerals are used for the same components as in the first embodiment, and the description thereof will be omitted or simplified.

In this second embodiment, a rotating link is provided on the lower link side. Specifically, suspension mesh bar-1
3 through the rubber bushing 40 at the lower pivot position.
A substantially triangular rotating link 41 is connected, and a lower arm 42 as a lower link is connected to another vertex of the rotating link 41.
are connected via a rubber bush 43. Further, an upper arm 44 serving as an upper link is swingably connected between the upper pivot position U of the suspension member 13 and the knuckle. The locking position M of the upper arm 44 is connected to one end of a control link 46 via a rubber bushing 45, and the other end of the link 46 is connected to the remaining apex portion of the rotation link 41 via a rubber bushing 47.

Furthermore, upper arm 44. The lower arm 42 is disposed in a shape that is narrowed toward its own wheel when viewed from the front-rear direction of the vehicle. The rest of the structure is the same as that of the first embodiment.

Therefore, in the bound state during turning, as the arms 44 and 42 swing toward the vehicle body, the rotating link 41 is also rotationally displaced toward the vehicle body 2, as shown by the solid line in FIG. . At this time, the lower arm attachment point 43 of the rotation link 41
draws a locus that bulges toward its own wheel, so the lower arm 42 is urged toward its own wheel and moves, causing the ground camber angle of the wheel 11R (IIL) to tend to be negative. The inner ring 11L (IIR) side has a positive tendency due to the opposite operation.

On the other hand, since the instantaneous centers of rotation of the wheels are located on the outside of the vehicle, the roll center is also located below the road surface, and a jack-down effect can be obtained as in the first embodiment.

Therefore, the second embodiment also provides the same effects as the first embodiment.

Note that the rotating link in the present invention is not limited to the substantially triangular shape as described in each of the above embodiments, and may be a pivot position (mounting position on the wheel side) of the suspension member, which is a vehicle body side member, with respect to the rotating link. However, any shape may be used as long as it can maintain the position inside the vehicle when viewed from the longitudinal direction of the vehicle relative to the mounting position of the rotation link relative to the control link.

Further, the type of vehicle suspension to which the present invention is applied is not limited to the double wishbone type as described above, but may be a so-called multi-link type.

〔Effect of the invention〕

As explained above, the present invention arranges both the upper link and the lower link so that they narrow toward the outside of the vehicle when viewed from the longitudinal direction of the vehicle, and also swings the end of the upper link (or lower link) on the vehicle body side. A rotating link that is movably supported and rotatably attached to a predetermined mounting position on the vehicle body side member; As a result, the instantaneous rotation center of the wheel is formed on the outside of the vehicle, and the roll center is formed below the road surface, so when turning with high lateral acceleration, the outer wheel is pushed down by the cornering force. The force becomes dominant and a jacking down effect is obtained, and when the outer wheel side transitions to a bound (bump) state during a turn, the control link relatively biases the rotation link upwards of the vehicle, which reduces rotation. The link rotates around a predetermined attachment position with the vehicle body side member, and with this movement, the upper link is displaced to the inside of the vehicle (or the lower link is displaced to the outside of the vehicle), and the camber angle of the outer wheel relative to the ground becomes negative. or strengthen negative tendencies. As a result,
Jack down or negative camber as before
Compared to a structure in which only one of the above can be obtained, the turning stability particularly when turning at a high lateral acceleration can be significantly improved.

[Brief explanation of drawings]

1 to 3 are diagrams showing a first embodiment of the present invention, in which FIG. 1 is a schematic configuration diagram when viewed from the rear side of the vehicle, and FIG. 2 is a rotation state of the outer wheel side bracket when turning. FIG. 3 is an explanatory diagram showing a rolling state during turning. 4 and 5 are diagrams showing a second embodiment of the present invention, in which FIG. 4 is a schematic configuration diagram of one wheel when viewed from the rear side of the vehicle, and FIG. 5 is a bound state of the outer wheel side. FIG. Fig. 6 is a schematic configuration diagram of a conventional example when viewed from the rear side of the vehicle, Fig. 7(a) and (b) are explanatory diagrams showing the mechanism of camber change in the conventional structure, respectively, and Fig. 8(a) (b) is an explanatory diagram showing the mechanism of jacking up and jacking down, respectively. 11L, IIR...Wheel, 13...Suspension member, 20.41...Bracket, 21...Rubber bush (upper pivot position U), 23.44...
Upper arm, 25.46... Control link, 28.40... Rubber bush (lower pivot position L)
), 29.42...lower arm

Claims (1)

[Claims] (1) In a vehicle suspension having an upper link and a lower link that are swingably interposed between a vehicle body side member and each wheel, when the upper link and the lower link are viewed from the front and back direction of the vehicle, both links are located on the outside of the vehicle. Both links are arranged so as to narrow toward the vehicle body, and the vehicle body side end of one of the upper link and the lower link is swingably supported and is rotatable to a predetermined mounting position of the vehicle body side member. A suspension for a vehicle, comprising: an attached rotating link; and a control link that connects the other link to a mounting position of the rotating link closer to a wheel than the predetermined mounting position.