JP2605689Y2 - Sub-frame mounting structure for double wishbone suspension - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an automobile suspension, and more particularly to a sub-frame mounting structure for a double wishbone suspension.

[0002]

2. Description of the Related Art A double wishbone suspension for a motor vehicle is shown in FIG.
And a sub-frame 15 suspended and supported between a pair of vehicle body side members 14 provided along both lower sides of the vehicle body 13.
An upper arm 16 and a lower arm 17 having an inner end pivotally supported by the sub-frame 15 and an outer end pivotally mounted to the housing 12, a shock absorber having an upper end supported by the vehicle body 13 and a lower end pivotally mounted to the housing 12, and It has a vertical force transmission member (not shown) made of a spring provided along the shock absorber.

[0003] As shown in a sectional view of a main part of FIG. 4, a floating bush 16L and a sub-frame 15 are connected to each other.
16R. The floating bushes 16L, 16R are provided on the lower surface 14a of the vehicle body side member 14.
The base end is fixed to the shaft 16a, the shaft 16a extends in the vertical direction, the outer cylinder 16b fitted to the shaft 16a and fixed to the end of the sub-frame 15, and the shaft between the shaft 16a and the outer cylinder 16b. It is formed by the rubber-like elastic body 16c mounted.

Further, a stopper 17 is provided at the lower end of the shaft 16a to abut on the elastic body 16c to the outer cylinder 16b to regulate the relative movement amount between the vehicle body 13 and the sub-frame 15.

[0005] In the suspension configured as described above, when a lateral force F inwardly acts on the wheels 11 from the road surface due to the turning of the vehicle or the like, the wheels 1 of the sub-frame 15 are moved.
1 force acts F ₂ to the outside direction of the lateral force F ₁ and the upper in a portion opposite to the and the lateral force F ₃ and a lower inner direction in the portion of the sub-frame 15 of the wheel 11 side Force F
₄ works.

Therefore, when a lateral force F acts on the ground contact point of the wheel 11 due to turning or the like, the floating bush 16L located on the turning outer wheel side is downward and inward, and the floating bush 16R located on the turning inner wheel side is inverted. Upward and outward. As a result, the sub-frame 15 swings above the floating bushes 16L and 16R with the swing center O.
And moves relatively to the vehicle body 13 in the roll direction R. The ground contact point of the wheel largely moves inward, and there is a problem that a cornering force is delayed and good maneuverability is hindered. In addition, it is necessary to raise the floor surface in order to avoid interference between the upper arm 16 and the vehicle body side member 14 at the time of swinging, and there is a problem that the stability is further reduced.

As a countermeasure, a floating bush 20 interposed between a vehicle body and a subframe is connected to a first bush 21 and a first bush 21 as disclosed in Japanese Patent Application Laid-Open No. 3-287405 and shown in a cross section in FIG. The first bush 21 includes an inner cylinder 24 extending vertically along an axis 23, an outer cylinder 25 fitted to the inner cylinder 24, and interposed therebetween. It is composed of a rubber-like elastic body 26. The outer peripheral surface of the inner cylinder 24 is inclined inward when viewed from the lower end to the upper end inside the vehicle.
5 has an inner peripheral surface formed in parallel with the outer peripheral surface of the inner cylinder 24.

Similarly, the second bush 22 has an inner cylinder 27 extending vertically along an axis 23, an outer cylinder 28 fitted to the inner cylinder 27, and a rubber-like material interposed therebetween. The outer cylinder 2 is made of an elastic body 29, and the outer peripheral surface of the inner cylinder 27 is inclined inward when viewed from above inside the vehicle.
8 is formed in parallel with the outer peripheral surface of the inner cylinder 27.

With this configuration, a vehicle suspension has been proposed in which the spring constant in the vertical direction is increased, and substantial roll displacement is suppressed from occurring in the sub-frame even when the vehicle turns.

[0010]

According to the vehicle suspension described above, the vertical spring constant of the floating bush interposed between the vehicle body and the subframe is increased, and the ground contact point of the wheel 11 due to turning of the vehicle or the like. When lateral force acts on the sub-frame, the roll displacement of the sub-frame is suppressed, and good maneuverability can be secured. However, since the spring constant in the vertical direction of the floating bush is increased, vibration and noise are induced when the vehicle is running, and the shape and configuration of the floating bush are complicated, leading to an increase in manufacturing cost. .

Therefore, an object of the present invention is to suppress the roll displacement of the sub-frame even when the lateral force acts on the ground contact point of the wheel without increasing the vertical spring constant of the floating bush, and having a simple structure. It is an object of the present invention to provide a sub-frame mounting structure for a double wishbone suspension which can ensure good operability.

[0012]

In order to achieve the above object, the double wishbone suspension subframe mounting structure according to the present invention has a floating bush between lower surfaces of a pair of vehicle body side members provided along both lower sides of the vehicle body. In the sub-frame mounting structure of the double wishbone suspension to be mounted, the lower surface of the vehicle body side member is inclined so as to rise as it moves toward the vehicle body end, and the floating bush has its base end coupled to the lower surface and moves downward. A shaft inclined so as to move toward the vehicle body side end as it moves, an outer cylinder fitted to the shaft and fixed to an end of the subframe, and a rubber-like member interposed between the shaft and the outer cylinder. And a spring constant of the floating bush is set when the sub-frame moves downward. Person in the case of more upward movement is what is larger.

[0013]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of a double wishbone suspension according to an embodiment of the present invention;

FIG. 1 is a schematic explanatory view as viewed from the rear side of the vehicle body. In the figure, reference numeral 1 denotes a vehicle body, and a pair of vehicle body side members 2 are provided along both lower sides of the vehicle body 1. The vehicle body side member 2 has a substantially hat shape in cross section, and its lower surface 2a is inclined so as to gradually rise as it moves toward the vehicle body end toward the upper surface 4c of the upper arm 4 at the time of the maximum bump described later.

A sub-frame 3 having both ends coupled to each other via floating bushes 8L and 8R to be described later is suspended between the vehicle body side members 2.

At the end of the sub-frame 3, an upper arm 4 whose inner end 4a is pivotably supported and a lateral link 5 whose inner end 5a is also pivotably mounted are arranged. The outer end 4b of the upper arm 4 and the outer end 5a of the lateral link 5 are swingably connected to a housing 7 that rotatably supports the wheels 6. The two-dot chain line 4 'indicates the position of the upper arm 4 at the time of the maximum bump.

Further, an upper end is supported by the vehicle body 1 and a lower end is provided with a vertical force transmitting member (not shown) composed of a shock absorber pivotally mounted on the housing 7 and a spring disposed along the shock absorber. .

As shown in FIG. 2, the floating bushes 8L and 8R connecting the vehicle body side member 2 and the subframe 3 have their base ends fixed to the lower surface 2a of the vehicle body side member 2 and move downward. A shaft 8a inclined so as to sequentially move toward the vehicle body end in accordance with the following, an outer cylinder 8b loosely fitted to the shaft 8a and fixed to an end of the sub-frame 3, and a shaft 8a.
a between the shaft 8a and the outer cylinder 8b.
It is formed by a rubber-like elastic body 8c adhered to b.

At the end of the shaft 8a, there is provided a stopper 9 which comes into contact with the lower end of the elastic body 8c and regulates the relative movement amount between the vehicle body 1 and the sub-frame 3.

Normally, the upper end of the elastic body 8c is in contact with the lower surface 2c of the vehicle body side member 2, and the lower end is formed to face the stopper 9 with a predetermined gap therebetween, so that the floating bushes 8L, 8R Is set to be larger when the sub-frame 3 moves upward than when it moves downward.

In the suspension configured as described above, when an inward lateral force F acts on the wheels 6 due to turning of the vehicle or the like, an outward lateral force F is applied to a portion of the subframe 3 opposite to the wheels 6. ₁ and the force F ₂ acts upward, and the force of the lateral force F ₃ and a lower inward F ₄ acts on the portion of the sub-frame 3 of the wheel 6 side.

Accordingly, when the lateral force F acts on the ground contact point of the wheel 6 due to turning or the like, the floating bush 8L located on the turning outer wheel side is downward and inward, and the floating bush 8R located on the turning inner wheel side is applied to the floating bush 8R. On the contrary, a force acts to displace upward and outward.

However, the end of the subframe 3 located on the turning inner wheel side moves toward the vehicle body end as the shaft 8a constituting the floating bush 8R supporting the end moves downward, that is, The elastic body 8 is inclined so as to move toward the turning outer wheel as it moves upward.
The upper end of the sub frame 3 abuts against the lower surface 2c of the vehicle body side member 2 and the spring constant in the direction in which the sub-frame 3 moves upward is set to a large value. I do.

On the other hand, the sub-frame 3 located on the turning outer wheel side
Moves downward because the shaft 8a that constitutes the floating bush 8L that supports the end is inclined so as to move toward the vehicle body end, that is, toward the turning outer wheel, as the shaft 8a that supports the end moves downward. Move to the turning outer wheel side. As a result, the sub-frame 3 has a swing center O
Is set downward and on the turning inner wheel side, the roll amount is suppressed, and the lateral movement of the wheel contact point is suppressed, so that a delay in the cornering force is avoided and the operability is improved.

Further, since the spring constants of the floating bushes 8L and 8R can be set relatively low, the generation of vibration and noise during traveling can be suppressed, and the lower surface 2a of the vehicle body side member 2 can be mounted on the upper arm 4 at the time of maximum bump. In combination with the inclination along the upper surface 4c, a low floor surface is secured while maintaining a sufficient cross-section in terms of strength, and the operability is further improved.

In the above description, the shaft 8a, the outer cylinder 8b and the shaft 8
Although the embodiment using the floating bushes 8L and 8R made of the elastic body 8c between the inner cylinder and the outer cylinder 8b has been described, the inner cylinder fitted to the shaft 8a is provided between the inner cylinder and the outer cylinder. It is also possible to use a floating bush with an elastic body interposed.

[0027]

According to the sub-frame mounting structure of the double wishbone suspension according to the present invention described above, the lower surface of the vehicle body side member to which the base end of the shaft of the floating bush supporting the sub-frame is fixed is directed toward the vehicle body side end. Incline to rise as you transition to
And the axis of the floating bush is inclined so as to shift toward the vehicle body end as it shifts downward, and the spring constant of the floating bush is larger when the subframe moves upward than when it moves downward. By setting so that, when the lateral force acts on the wheels due to turning etc., the roll rotation center of the sub-frame is located below, and is set to the turning inner wheel side, the lateral movement of the wheel ground point is suppressed, The cornering force delay is reduced and the operability is improved.Furthermore, the spring constant of the floating bush does not need to be extremely large, vibration and noise can be reduced, the structure is simple and the manufacturing cost can be reduced. Together with this, the practical effect is great.

[Brief description of the drawings]

FIG. 1 is a schematic explanatory view showing a main part of an embodiment of a sub-frame mounting structure of a double wishbone suspension according to the present invention as viewed from a rear side of a vehicle body.

FIG. 2 is an explanatory cross-sectional view of a main part, similarly showing a connection structure between a vehicle body side member and a subframe.

FIG. 3 is a schematic explanatory view showing a main part of a conventional double wishbone suspension viewed from the rear of a vehicle body.

FIG. 4 is an explanatory sectional view of a main part, similarly showing a connection structure between a vehicle body side member and a subframe.

FIG. 5 is a sectional view of a floating bush used to connect a conventional vehicle body side member and a subframe.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Body 2 Body side member 2a Lower surface 3 Subframe 4 Upper arm 4a Upper surface 8L, 8R Floating bush 8a Shaft 8b Outer cylinder 8c Elastic body

Continuation of front page (56) References JP-A-1-275205 (JP, A) JP-A-1-278810 (JP, A) JP-A-3-287405 (JP, A) JP-A-7-167208 (JP) , A) Japanese Utility Model Application Showa 62-196778 (JP, U) Japanese Utility Model Application Hei 4-9312 (JP, U) Japanese Utility Model Application Showa 62-49404 (JP, U) Japanese Utility Model Application Hei 5-25283 (JP, Y2) (58) Surveyed field (Int.Cl. ⁷ , DB name) B62G 3/20 B62G 7/00 B62D 21/00 B62D 21/11

Claims (2)

(57) [Scope of request for utility model registration] 1. A sub-frame mounting structure for a double wishbone suspension mounted via a floating bush between lower surfaces of a pair of vehicle body side members provided along both sides of a lower portion of the vehicle body, with the lower surface of the vehicle body side member facing the vehicle body end. The floating bush is fitted to the shaft, the shaft being inclined so as to ascend as it moves to, and having the base end coupled to the lower surface, and inclined so as to move toward the vehicle body end as it moves downward. An outer cylinder fixed to the end of the sub-frame, and a rubber-like elastic body interposed between the shaft and the outer cylinder, and the spring constant of the floating bush is such that the sub-frame moves downward. Sub-frame mounting structure for a double wishbone suspension, which is larger when moving upward than when Build. 2. A sub-frame mounting structure for a double wishbone suspension according to claim 1, wherein the lower surface of the vehicle body side member is inclined along the upper surface of the upper arm at the time of the maximum bump.