JP3601352B2 - Vehicle suspension device - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a vehicle suspension device, and in particular, attaches a knuckle for pivotally supporting wheels to a lower wall component of a vehicle body via an independent suspension having a link mechanism using an upper arm and a shock absorbing mechanism using a coil spring. The present invention relates to a vehicle suspension device.
[0002]
[Prior art]
The suspension system of the vehicle has a link mechanism that connects the wheels to the vehicle body so that it can move up and down, and a shock absorbing mechanism that absorbs the fluctuation component of the road surface reaction force input via the wheels. In addition, the impact on the occupants on the vehicle body side is reduced, and the comfort is improved.
Among these suspension devices, a double wishbone type independent suspension suspension equipped with a link mechanism having a plurality of suspension arms such as an upper arm and a lower arm, and a shock absorbing mechanism in which a coil spring and a shock absorber are juxtaposed provides steering stability and comfort. It is often used as an excellent one.
By the way, the double wishbone type independent suspension, especially when turning, causes the roll center to move to the outer wheel side due to the roll of the vehicle and generates an upward reaction force on the roll center, which makes the steering unstable during turning. In some cases, a so-called jack-up phenomenon may occur, and it is effective to increase the length of the upper arm as one of preventive measures.
[0003]
For this reason, when manufacturing a double wishbone type independent suspension, the upper arm is set as long as possible, but in such a configuration, the pivot end of the upper arm should be attached to the center of the vehicle as much as possible. However, the length of the upper arm cannot be sufficiently secured because the side wall of the vehicle is often restricted.
Therefore, it is considered effective to pivot the base end side of the upper arm below the floor of the passenger compartment, and an example thereof is disclosed in JP-A-9-158969. This rear suspension device has a sub-frame whose front and rear ends are supported by side members below the floor, and whose intermediate portion is formed to curve toward the center of the vehicle body. A pivotal end of an upper arm is pivotally supported on the intermediate curved portion of the subframe, and pivotally supports the upper arm below the floor.
[0004]
[Problems to be solved by the invention]
However, in the rear suspension device disclosed in Japanese Patent Application Laid-Open No. Hei 9-1589697, the sub-frame receives the load from the upper arm in the central curved portion, and distributes the load to the side members from the front and rear ends outside the vehicle from that position. . For this reason, the subframe is always subjected to torsional stress, and there is a problem in securing durability. In addition, the upper end of the coil spring is connected to the side member, and the coil spring needs to be separately attached to the side member separately from the link mechanism during the assembling operation. .
An object of the present invention is to provide a vehicle suspension device that can ensure durability and has good assembling workability.
[0005]
[Means for Solving the Problems]
In order to achieve the above object, the invention according to claim 1 includes a subframe having a vehicle width direction extending member and a pair of left and right front and rear direction extending members, wherein the vehicle width direction extending member is arranged in a vehicle longitudinal direction. The left and right ends are tightened and connected to a pair of left and right side members extending to the vehicle body, and the rear ends of the pair of left and right front and rear extension members are disposed at a predetermined amount from the left and right ends of the same vehicle width direction extension member toward the center of the vehicle body. At the position where the front end is disposed at a predetermined amount from the left and right ends of the cross member that connects the two side members to the center of the vehicle body, and has an upper arm, and one end of the upper arm pivotally supports the wheel. The other end is connected to the front and rear direction extending member, and the lower arm is connected to the front and rear direction extending member, and the lower arm is connected at one end to the wheel supporting member and the other end is connected to the vehicle width direction extending member. , The vehicle width direction extension It is deploying a coil spring between the right and left ends and the upper portion of the lower arm.
[0006]
Here, the rear ends of the front and rear extending members are fixedly joined to the vehicle body center by a predetermined amount from the left and right ends of the vehicle width direction extending member, and the front ends thereof are tightened to the vehicle center by a predetermined amount from the left and right ends of the cross member. Are combined. As described above, since the front-rear extension members are disposed closer to the center of the vehicle than the left and right side members, the upper arm connecting the front-rear extension member and the knuckle can be formed relatively long, and the upper arm is used. Steering instability due to the jack-up phenomenon that easily occurs with an independent suspension can be prevented. In addition, since the coil springs are connected to the left and right ends of the vehicle width direction extending member, the link mechanism including the upper arm and the lower arm and the coil springs are incorporated into the subframe, and the suspension device can be assembled after subassembly. Thus, the assembling work on the assembling line is facilitated.
[0007]
BEST MODE FOR CARRYING OUT THE INVENTION
FIGS. 1 to 3 show a rear suspension device S as a vehicle suspension device to which the present invention is applied.
The rear suspension device S employs a four-wheel independent suspension system, and includes a chassis member 1 (see FIG. 3) as a sub-frame which is provided at a lower portion of a vehicle body (not shown) and a sub-frame to which a plurality of portions are tightened and connected. On the other hand, the rear wheel 2 is connected via a link mechanism s1 and a shock absorbing mechanism s2.
Here, as shown in FIGS. 1 and 2, the lower wall component member has a pair of left and right members which are joined to the floor member 3 whose upper surface is opposed to the cabin R and the lower surface of the floor member 3 and are long in the front-rear direction X of the vehicle body. It comprises a side member 4 and a cross member 5 for integrally connecting the two side members. The cross member 5 is welded to a relatively front side (upper side in FIG. 1) of the pair of left and right side members 4, and front left and right front mounting portions J1 are formed at a predetermined amount from the left and right ends of the cross member 5 toward the vehicle body center. In addition, a rear left and right rear mounting portion J2 is formed at a relatively rear side (a lower side in FIG. 2) of the pair of left and right side members 4, respectively.
[0008]
Each of the mounting portions J1 and J2 is provided with a bolt hole (not shown) for vertically inserting a tightening bolt (not shown), and a chassis member abutted on the lower surface of each of the mounting portions J1 and J2 by the bolt inserted into the bolt hole. Each of the opposing portions on one side is configured to be fastened and joined.
As shown in FIG. 3, the chassis member 1 that is fastened and joined to the lower wall component member has a vehicle width direction extending member 6 that extends in the vehicle width direction Y and a rear end that is attached to the vehicle width direction extending member 6. A pair of left and right front-rear extension members 7 extending in the front-rear direction X is provided.
[0009]
The vehicle width direction extending member 6 extends straight in the vehicle width direction Y as shown in FIG. 1 in plan view, and extends in a bent bar shape as shown in FIG. 2 in rear view. . That is, the vehicle width direction extending member 6 has a straight central portion 601, a rising portion 602 extending obliquely upward from the lower bent side ends 604 on both sides of the central portion 601, and a vehicle width extending from the left and right ends of the rising portion 602. And a spring receiving end 603 extending substantially horizontally outward in the direction Y. As shown in FIG. 4, the upper plate 6a and the lower plate 6b having a hat-shaped cross section are overlapped with each other to form a peripheral portion. Are welded to form a closed cross-sectional shape. The vehicle width direction extending member 6 has upper and lower plate members 6a and 6b formed at both ends as dish-shaped ends, and these are vertically stacked to form a dish-shaped spring receiving end 603. The center portion of the spring receiver is formed with a bolt hole h, which is superimposed on each of the rear mounting portions J2 of the left and right side members 4 and fastened and fixed with a fastening bolt (not shown).
[0010]
A pair of left and right longitudinally extending members 7 extending in the longitudinal direction X and juxtaposed to each other have their rear ends a predetermined distance from the left and right ends of the vehicle widthwise extending member 6 toward the vehicle body center, that is, the spring receiving end 603. The front end is welded and fixed to the side wall on the center side of the vehicle body, and the front end is fastened and fixed to a pair of left and right front mounting portions J1 on the cross member 5. The front and rear extension members 7 form substantially straight bar members, and are arranged side by side with respect to the both side members 4 on the center side of the vehicle body. Here, the front and rear extending members 7 are joined at their intermediate portions to each other by a pipe member 8, and their front ends are connected to both front mounting portions J1 of the cross member 5, and their rear ends are connected to the vehicle width direction extending members. 6 is welded. Therefore, the rigidity of the chassis member 1 as a whole as well as the rigidity of the pair of left and right longitudinally extending members 7 is sufficiently enhanced.
[0011]
The front and rear arm brackets 9 and 11 are joined and fixed to the outer wall surface of the middle part of the front and rear arm members 7 at predetermined intervals in the front and rear direction. A base end of an upper arm 12 described later as a suspension arm is connected to the front and rear arm brackets 9 and 11. In this case, of the input loads from the front and rear arm brackets 9 and 11, the load in the vehicle width direction is mutually canceled by the pipe member 8, and the other loads applied to the front and rear extension members 7 are mounted on the front and rear sides. It is dispersed and transmitted to the cross member 5 and the vehicle width direction extending member 6 via the portion J1 and both rear mounting portions J2. At this time, each of the straight front and rear direction extending members 7 generates only bending stress. It is configured such that no torsional stress is generated. Note that a differential device (not shown) is supported by such a chassis member 1 via a reinforcing member 27.
[0012]
The link mechanism s1 of the rear suspension device S is provided with a knuckle 15 for pivotally supporting the rear wheel 2 as shown in FIGS. It is connected to the vehicle body using two suspension arms. Here, four suspension arms including a lower arm 16, an upper arm 12, a toe control arm 17, and a trailing arm 18 are arranged in parallel between the knuckle 15 and the vehicle body. That is, the lower arm 16 is rotatably pin-connected to the lower boss 151 of the knuckle 15 and the lower bent side end 604 of the vehicle width direction extending member 6 via a rubber bush (not shown). Are connected to the upper boss 152 of the knuckle 15 via a ball joint (not shown), and the base end is rotatably pin-connected to the front and rear arm brackets 9 and 11 of the front / rear extending member 7 via rubber bushes (not shown), respectively. The toe control arm 17 is rotatably pin-connected to the front boss 153 of the knuckle 15 and the downward bracket 19 of the front-rear extension member 7 via a rubber bush (not shown), and the trailing arm 18 is connected to the upper boss of the knuckle 15. An upper front boss (not shown) near 152 and the cross member mounting structure position of the side member 4 at the front side Is rotatably pin-connected via a rubber bush (not shown) respectively to the railing arm bracket 20.
[0013]
In the link mechanism s1, as shown in FIG. 5, an intersection P1 at which both the extension lines of the lower arm 16 and the trailing arm 18 intersect is set, and a king pin connecting this to the position P2 of the ball joint at the swing end of the upper arm 12. The axis K is set. Here, the rotational displacement of the rear wheel 2 and the knuckle 15 side around the kingpin axis K is prevented by the toe control arm 17, and is configured as a link mechanism for non-steered wheels.
The shock absorbing mechanism s2 of the rear suspension device S absorbs and reduces the reaction force fluctuation component from the road surface e input from the rear wheel 2, and includes a coil spring 13 and a shock absorber. The left and right coil springs 13 are mounted between the spring receiving end 603 formed on the vehicle width direction extending member 6 and the spring receiver 161 in the middle of the lower arm 16 in a state of being biased by compression. The pair of left and right shock absorbers 14 are pin-connected at their lower ends to lower end mounting portions 162 provided in the lower arm 16, and are pin-connected at upper ends to upper end mounting portions 22 provided on the side vertical wall plate 21 on the vehicle body side via cushioning members. Is done.
[0014]
The left and right rear wheels 2 are regulated by a stabilizer 23 disposed in the vehicle width direction with respect to excessive relative vertical fluctuation. The stabilizer 23 is a torsion bar made of metal, and its left and right ends are fastened to the front lower wall of the longitudinally extending member 7 by stabilizer brackets 24 via rubber bushes (not shown). The left and right ends of the stabilizer 23 form a straight lever portion 231, and the front end portion is pin-connected to the lower end of the vertical link 25. Each vertical link 25 has its upper end pin-connected to a mounting piece 26 welded to the lower surface of the opposing upper arm 12. As described above, the stabilizer 23 is securely supported by the chassis member 1, but is appropriately bent to avoid interference with peripheral members.
At the time of production of a vehicle equipped with the above-described rear suspension device S, a link mechanism s1, an impact absorbing mechanism s2, a stabilizer 23, a differential mechanism (not shown) and the like are temporarily assembled in the chassis member 1 in advance, and the chassis production line is used as a chassis member assembly. Supplied to
[0015]
In this production line, four fastening portions of the chassis member 1 are opposed to the lower wall component on the rear side of the vehicle body on which the above-described mounting portions J1 and J2 are formed. Then, the front ends of the left and right longitudinal extension members 7 are sequentially tightened and connected to the front left and right front mounting portions J1 of the cross member 5 with a tightening bolt (not shown), and the rear left and right rear mounting portions of the side member 4 are provided. The spring receiving ends 603 at the left and right ends of the vehicle width direction extending member 6 are sequentially tightened and connected to J2 with a tightening bolt (not shown). Thereby, the chassis member assembly side is easily and reliably supported by the lower wall constituent member. After the chassis member 1 is assembled, in the link mechanism s1, the front end of the trailing arm 18 is pin-coupled to the trailing arm bracket 20 in front of the cross member mounting structure position of the side member 4, and in the shock absorbing mechanism s2, the shock is absorbed. The upper end of the absorber 14 is pin-connected to an upper end mounting portion 22 provided on the side vertical wall plate 21. As a result, the rear suspension device S can be mounted by a relatively easy mounting operation.
[0016]
As described above, when assembling the chassis member assembly, it is only necessary to tighten and join the chassis member 1 side to the pair of left and right side rails 4 and the cross member 5 as the lower wall constituent members, and the assembly work performed on the production line is extremely small. , Workability can be improved. In addition, since the components on the chassis member assembly side are accurately assembled in advance to the chassis member 1, the assembly accuracy after the outfitting can be easily ensured.
[0017]
Further, in such a rear suspension device S, the pair of left and right front-rear extending members 7 including the opposing portions of the front and rear mounting portions J1 and J2 are all arranged side by side with respect to both side members 4 at the center of the vehicle body. Therefore, the upper arm 12 pivotally supported by each of the front and rear arm brackets 9 and 11 on each of the front and rear extension members 7 can have a relatively long arm length in the vehicle width direction. As described above, the length of the upper arm in the double wishbone type independent suspension can be set to be long, and the occurrence of a so-called jack-up phenomenon that causes instability of steering during turning can be suppressed. In addition, at this time, even if a road surface reaction force is input to the front-rear extending member 7 from the upper arm 12 via the front-rear arm brackets 9 and 11, the input load is applied to both the front mounting portion J1 and the rear mounting portion J2. The transmission is distributed to the cross member 5 and the vehicle width direction extending member 6 via the shaft. At this time, each of the straight front and rear direction extending members 7 generates only bending stress, and does not generate torsional stress. Sufficient durability can be secured. In particular, the input load in the vehicle width direction here is mutually canceled by the pipe member 8, and the chassis member 1 including the longitudinally extending member 7 can secure more sufficient durability.
[0018]
In the above-described process, the middle portions of the front and rear extension members 7 are connected to each other by the pipe member 8. However, the pipe member 8 may be omitted in some cases to simplify the structure of the chassis member 1. In this case, substantially the same operation and effect as those of the rear suspension device S of FIG. 1 can be obtained.
Although the rear suspension device S of FIG. 1 has four suspension arms, the present invention can be applied to a double wishbone type independent suspension suspension having other upper arms. In those cases, the rear suspension device S of FIG. Almost the same effects can be obtained. Further, although the rear suspension device S has been described in the above description, the present invention can be applied to a front-side suspension device, and in those cases, substantially the same operation and effects as those of the rear suspension device S of FIG. 1 can be obtained.
[0019]
【The invention's effect】
According to the first aspect of the present invention, since the front and rear extending members are disposed closer to the center of the vehicle body than the left and right side members, the upper arm connecting the front and rear extending members and the knuckle can be formed relatively long. Instability due to the jack-up phenomenon that tends to occur in the independent suspension using the suspension can be prevented. In addition, since the coil springs are connected to the left and right ends of the vehicle width direction extending member, the link mechanism including the upper arm and the lower arm and the coil springs are incorporated into the subframe, and the suspension device can be assembled after subassembly. Thus, the assembling work on the assembling line is facilitated.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view of a main part of a rear suspension device as one embodiment of the present invention in plan view.
FIG. 2 is a sectional view of a main part of the rear suspension device of FIG. 1 as viewed from the rear.
FIG. 3 is a perspective view of a subframe in the rear suspension device of FIG. 1;
FIG. 4 is an enlarged cross-sectional view taken along line AA of FIG. 2;
FIG. 5 is a functional explanatory diagram of a link mechanism in the rear suspension device of FIG. 1;
[Explanation of symbols]
REFERENCE SIGNS LIST 1 chassis member 2 rear wheel 4 side member 5 cross member 6 vehicle width direction extending member 7 front and rear direction extending member 12 upper arm 13 coil spring 15 knuckle 16 lower arm s1 link mechanism s2 shock absorbing mechanism X body longitudinal direction S rear suspension device

Claims (1)

A vehicle width direction extending member whose left and right ends are tightened and coupled to a pair of left and right side members extending in the vehicle front and rear direction, and a rear end is located at a predetermined distance from the left and right ends of the vehicle width direction extending member to the center of the vehicle body. A pair of left and right front-rear extending members fastened and joined at a position where the front end is disposed at a predetermined distance from the left and right ends of the cross member connecting the two side members to the center of the vehicle body at a deployed position. Sub-frame, an upper arm having one end connected to a wheel support member pivotally supporting the wheel and the other end connected to the front-rear extension member, one end connected to the wheel support member, and the other end extending in the vehicle width direction. A vehicle suspension device comprising: a lower arm connected to an extension member; and a coil spring disposed between left and right ends of the vehicle width direction extending member and an upper portion of the lower arm.

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