JP3794528B2 - Car suspension equipment - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an automobile suspension device, and more particularly to a torsion beam type rear suspension device.
[0002]
[Prior art]
As a conventional automobile suspension device, a torsion beam connected between the left and right rear wheels, and a plate-like structure that allows displacement in the vehicle width direction, extending from both ends of the torsion beam in the vehicle body length direction, respectively. The trailing arm is supported by the body frame via the bush, and the trailing end of each trailing arm is joined to the left and right ends of the torsion beam by welding or the like. There is another torsion beam type rear suspension device (refer to Japanese Patent Laid-Open No. 4-283114).
[0003]
This torsion beam type rear suspension device has been installed in light vehicles for some time because of its simple structure and low cost, but the center of the coil diameter of the coil spring is not directly above the trailing arm or torsion beam, but against the torsion beam. By arranging the coil springs at an offset position, the floor height can be lowered and the rear luggage space can be widened. Demand for wagon-type and box-type automobiles in recent years has been increased. Has increased.
[0004]
[Problems to be solved by the invention]
However, in the technique of the above publication, when a spring seat or its bracket is formed at the corner portion, the substantial effective length of the trailing arm is shortened, so that the torsional elasticity is increased and the riding comfort is deteriorated. For this reason, it is conceivable to lengthen the trailing arm as the effective length is shortened, but doing so deteriorates the layout. Although it is conceivable to lengthen the torsion beam, it is necessary to increase the strength of the part where the torsion beam torsional elasticity becomes too low and the running stability is deteriorated or the torsion beam torsional stress is concentrated. There is a risk of increasing costs.
[0005]
In addition, in the suspension device in which the coil diameter center of the coil spring is offset with respect to the torsion beam, the torsional beam torsion peels off the joining surface of the spring seat and the torsion beam, and the torsional stress is concentrated even if the joining strength is increased. As a result, there is a problem that cracks occur on the joint surface of the torsion beam.
[0006]
The present invention has been made in view of the above-described problems, and an object of the present invention is to provide a suspension device for an automobile that can suppress suspension of a spring seat and crack of a beam due to concentration of torsional stress of a torsion beam, and can maintain suspension performance at a low cost. That is.
[0007]
[Means for Solving the Problems]
In order to solve the above-described problems and achieve the object, a suspension device for an automobile according to the present invention is a torsion beam type rear suspension device, which is fixed to a torsion beam connected between left and right wheels and an end of the torsion beam. A torsion beam corresponding to a joint portion of the coil spring seat, and the coil spring seat has a rear flange portion erected at the rear end in the vehicle longitudinal direction and a vehicle width. A box shape having inner and outer flange portions erected at both ends in the direction is provided, and at least the rear surface of the rear flange portion is joined to the front surface of the torsion beam in the longitudinal direction of the vehicle body .
[0008]
Preferably, the torsion beam has an inverted U-shaped cross section that opens downward, and the lower open end edge of the coil spring seat is expanded compared to the others.
[0010]
Preferably, the reinforcing portion is formed at a location corresponding to a joint portion of the inner flange portion.
[0011]
Preferably, the reinforcing portion is formed at a location corresponding to a joint portion of the outer flange portion.
[0012]
Preferably, the plate further includes a plate-like trailing arm that extends from the torsion beam to a predetermined position in the vehicle longitudinal direction and is pivotally supported at the predetermined position, and the coil spring seat includes the trailing arm. Provided at a predetermined interval in the vehicle width direction.
[0013]
Preferably, a damper is further provided with a lower end pivotally supported at the predetermined interval.
The suspension device for an automobile according to the present invention is a torsion beam type rear suspension device, wherein a torsion beam connected between right and left wheels, a coil spring seat fixed to an end of the torsion beam, and a vehicle body longitudinal direction from the torsion beam. A plate-like trailing arm extending to a predetermined position and pivotally supported at the predetermined position, and means for allowing the torsion beam and the coil spring seat to be twisted and deformed. The coil spring seat is joined to one side of the torsion beam on the front side of the vehicle body, and the coil spring seat is provided at a predetermined interval in the vehicle width direction from the trailing arm. The lower end of the damper is pivotally supported at the lower end. The one end connected to the trailing arm, the other end is axially supported rotatably connected to a rod to the spring seat.
[0014]
【The invention's effect】
As described above, according to the first aspect of the present invention, the torsional strength for the portion where the torsional stress of the torsion beam tends to concentrate can be increased by forming the reinforcing portion on the torsion beam corresponding to the joint portion of the coil spring sheet. .
The coil spring seat has a box shape having a rear flange portion erected at the rear end in the vehicle longitudinal direction and inner and outer flange portions erected at both ends in the vehicle width direction, and at least the rear flange portion Since the back surface of the torsion beam is joined to the front surface of the torsion beam in the longitudinal direction of the vehicle body, the coil spring seat can be arranged offset to the torsion beam, the floor height can be lowered, and cracking of the torsion beam can be suppressed.
[0015]
According to the second aspect of the present invention, the torsion beam has an inverted U-shaped cross section opened downward, and the torsional stress of the torsion beam is concentrated by expanding the lower open end edge of the coil spring seat compared to the other. It is possible to increase the torsional strength for easy locations and suppress the occurrence of cracks and the like.
[0017]
According to the invention of claim 3 , the reinforcing portion is formed at a location corresponding to the joint portion of the inner flange portion, thereby increasing the torsional strength of the inner flange portion where the torsional stress of the torsion beam tends to concentrate, cracking, etc. Can be suppressed.
[0018]
According to the invention of claim 4 , the reinforcing portion is formed at a location corresponding to the joint portion of the outer flange portion, thereby increasing the torsional strength of the outer flange portion where the torsional stress of the torsion beam tends to concentrate, cracking, etc. Can be suppressed.
[0019]
According to the fifth and seventh aspects of the present invention, the coil spring seat is provided at a predetermined interval in the vehicle width direction from the trailing arm, so that the torsional stress of the torsion beam is easily sheared by the biasing force of the coil spring. Even if force is applied, the strength to suppress cracks and the like can be secured.
[0020]
According to the sixth and seventh aspects of the present invention, by further including a damper whose lower end is pivotally supported at a predetermined interval, the urging force of the coil spring and the damper can be applied to a location where the torsional stress of the torsion beam is likely to concentrate. Even if a shearing force is applied due to the damping force, it is possible to ensure the strength to suppress cracks and the like.
Further, according to the invention of claim 7, since the torsional deformation of the portion where the torsional stress of the torsion beam tends to concentrate can be allowed by the means for allowing the torsional deformation of the torsion beam, the peeling and the joining strength due to the torsional deformation of the torsion beam are strengthened. It is possible to suppress the occurrence of cracks due to.
[0021]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.
[0022]
FIG. 1 is a plan view of the automobile suspension device of the present embodiment. FIG. 2 is a plan view showing details of the vicinity of the end of the torsion beam. FIG. 3 is a side view showing details in the vicinity of the end of the torsion beam. FIG. 4 is an enlarged view of FIG.
[0023]
As shown in FIGS. 1 to 4, as an example of this embodiment, a plate-shaped trailing arm 1 having elasticity that allows twisting inward in the vehicle width, and left and right wheels extending in the vehicle width direction are illustrated. A torsion beam type rear suspension device including a torsion beam 4 (a beam having elasticity in a torsional direction) connected between two and three and arranged by offsetting the center of the coil diameter of the coil spring with respect to the axial center of the torsion beam 4 is there.
[0024]
The torsion beam 4 has an inverted U-shaped cross section that opens downward. The trailing arm 1 extends in the front-rear direction of the vehicle body, its front end 1a is rotatably supported by the floor arm 7 via a support bush 5 and a bracket 6, and the rear end 1b is opened rearward when viewed from the side. A concave portion is formed, and the concave portion is joined to the inner front surface from both ends of the torsion beam 4 by welding or the like to form a connecting portion 8 between the trailing arm 1 and the torsion beam 4 (see FIG. 3).
[0025]
A wheel support member 9 is joined to the left and right ends of the torsion beam 4, and a wheel support 11 having a spindle 10 is bolted to the upper end surface of the wheel support member 9, and the wheel is connected to the spindle 10 via a brake mechanism. (That is, rear wheels) 2 and 3 are attached.
[0026]
A substantially box-like lower spring seat 12 is joined to the front surface of the torsion beam 4 by welding or the like at a predetermined distance L (see FIG. 4) from the trailing arm 1 to the inside of the vehicle width. An upper spring sheet 13 is joined to the lower surface of the floor frame 7 by welding or the like so as to face each other, and a coil spring 14 is stretched between the upper and lower spring sheets 12 and 13.
[0027]
In the space of the predetermined interval L, a damper 15 is disposed so as to be substantially parallel to the vertical surface of the trailing arm 1 as shown in FIG.
[0028]
An upper end portion 15 a of the damper 15 is pivotally supported on the outer surface of the floor frame 7 by a mounting member 16. The lower end 15 b of the damper 15 is pivotally supported across the trailing arm 1 and the side surface of the lower spring seat 12. The lower end 15 b of the damper 15 is inserted into the bush 17 through a rod 18, and a hole 19 formed in the lower end of the trailing arm 1 and a rod mounting piece 12 a provided integrally with the lower spring seat 12. By inserting the nut 21 into the threaded portion 18a of the rod 18 and fixing the rod 18 to the trailing arm 1 and the rod mounting piece 12a of the lower spring seat 12 in a rigid manner. It is pivotally supported. Further, the damper 15 is rotatable around the longitudinal axis of the damper 15 orthogonal to the rotation axis of the bush 17, that is, in the direction of the arrow a shown in FIG.
[0029]
That is, the lower end portion 15 b of the damper 15 is disposed within a predetermined interval L, and is pivotally supported so as to be rotatable between the trailing arm 1 and the lower spring seat 12. A collar 22 is interposed on the inner surface of the lower end 15b and on the outer periphery of the rod 18 from the trailing arm 1 to the rod mounting piece 12a.
[0030]
A bump stopper rubber 23 is disposed between the torsion beam 4 and the floor frame 7 in the vicinity of the joint portion of the lower spring seat 12 to the torsion beam 4. Further, the upper support bush 24 extends over one of the floor frames 7 (the upper floor frame 7 in FIG. 1) located behind the torsion beam 4 and the back of the end of the torsion beam 4 far from the one floor frame 7. The lateral link 26 is stretched in a slant shape via the lower support bush 25 and restricts unnecessary movement of the trailing arm 1 in the vehicle width direction. In FIG. 1, F indicates the front direction of the vehicle body, and R indicates the rear direction of the vehicle body.
[0031]
As shown in FIG. 4, the lower spring seat 12 has an inner flange portion 12a in the vertical direction at the rear end in the vehicle front-rear direction and both ends in the vehicle width direction so that the upper end and the front end in the vehicle front-rear direction are opened. The outer flange portion 12b and the rear flange portion 12c are each formed in a box shape, and the rear edge of the inner and outer flange portions 12a, 12b and the rear surface of the rear flange portion 12c are in the longitudinal direction of the vehicle body of the torsion beam 4. It is joined along the front surface. Only the rear flange portion 12c may be joined to the torsion beam 4 and cantilevered.
[0032]
The coil spring seat 12 is cantilevered by the torsion beam 4 at the inner flange portion 12a, the outer flange portion 12b, and the rear flange portion 12c. The inner flange portion 12 a has an arm portion 12 e that extends to the top of the torsion beam 4.
[0033]
In the suspension device of the present embodiment, the end of the torsion beam 4 is twisted forward and displaced substantially directly above (slightly inward of the vehicle width) when the rear wheel bounces. Along with this, the rear end 1b of the trailing arm 1 is displaced while being twisted substantially right above (slightly inward in the vehicle width) along the circular arc locus with the support bush 5 as a fulcrum.
[0034]
By the way, when the torsion beam 4 is twisted, the inner flange portion 12a, the outer flange portion 12b, the rear flange portion 12c, and the arm portion 12e of the lower spring seat 12 have sufficient beam lengths with respect to the twist of the torsion beam 4. The occurrence of peeling due to torsional deformation and the occurrence of cracks in the torsion beam 4 due to torsional stress are small, but the outer flange portion 12b and the rear flange portion 12c have a shorter beam length than the torsion beam 4 torsion. Even if the joint strength of the joint portion is increased, the torsional stress is concentrated on the contrary, and a crack occurs at a corresponding portion of the torsion beam 4. This inconvenience easily appears when the upper end edge of the rear flange portion 12c is formed horizontally.
[0035]
Further, since the lower end portion 15b of the damper 15 is pivotally supported across the trailing arm 1 and the lower spring seat 12, the lower spring seat 12 has a biasing force in the extension direction of the coil spring 14 when the rear wheel bounces. The damping force of the damper 15 acts, and these act on the joint surface between the lower spring seat 12 and the torsion beam 4 as a shearing force in the peeling direction. For this reason, it is also necessary to increase the fatigue strength of the joint surface of the lower spring seat 12.
[0036]
Therefore, in the present embodiment, the above-described problem is solved by adopting a joining structure described below.
[First bonding structure]
FIG. 5 is a view showing a first joining structure of the lower spring seat 12 and the torsion beam 4. FIG. 6 is a front view of FIG.
[0037]
As shown in FIGS. 5 and 6, in the first joining structure, the upper end edge of the rear flange portion 12 c is formed so as to be inclined upward from the vehicle width outer side to the inner side.
[0038]
By this first joining structure, it is possible to suppress the peeling due to the torsional deformation of the torsion beam 4 at the joined portion of the rear flange portion 12c and the generation of cracks due to the strengthening of the joining strength to the torsion beam 4. Furthermore, by forming the arm portion 12e extending to the top of the torsion beam 4 on the inner flange portion 12a that is less affected by the torsional deformation of the torsion beam 4, it is possible to suppress the occurrence of cracks and increase the bonding strength.
[0039]
As a result, it is not necessary to improve the joining strength (welding strength) of the lower spring seat, and it is possible to reduce the unsprung weight without requiring an excessive increase in rigidity, and the running stability is also improved.
[Second bonding structure]
FIG. 7 is a view showing a second joining structure of the lower spring seat 12 and the torsion beam 4.
[0040]
As shown in FIG. 7, the second joining structure is such that a portion where the torsional stress tends to concentrate, that is, the inner flange portion 12 a of the lower spring seat 12 in the end edge portion 4 a bent substantially horizontally inward of the torsion beam 4. In addition, an extended portion 4b is formed by expanding a portion corresponding to the arm portion 12e as compared with the others, and the strength of the torsion beam 4 against torsional stress is increased. In addition, you may form the expansion part 4b in the location corresponding to the outer side flange part 12b.
[0041]
In the second joint structure, the strength of the torsion beam 4 with respect to a portion where the torsional stress tends to concentrate can be increased.
[0042]
[Third bonding structure]
FIG. 8 is a view showing a third joint structure of the lower spring seat 12 and the torsion beam 4. 9 is a cross-sectional view taken along the line XX in FIG.
[0043]
As shown in FIGS. 8 and 9, the third joint structure allows torsional deformation of the torsion beam 4 in the vehicle width direction at a position corresponding to the rear end edge of the inner flange portion 12 a and the joint surface on the front surface of the torsion beam 4. An uneven portion (bead portion) 4c is formed, and the recessed portion of the uneven portion 4c forms a non-welded portion with the inner flange portion 12a. In addition, you may form the uneven | corrugated shaped part 4c in the location corresponding to the joint surface of the outer side flange part 12a.
[0044]
In this third joint structure, the uneven portion 4c allows torsional deformation at a portion where the torsional stress of the torsion beam 4 is likely to concentrate, so that peeling due to torsional deformation of the torsion beam 4 or cracking due to increased bonding strength is prevented. Can be suppressed.
[0045]
Further, instead of forming the concavo-convex shape portion 4c, a gap that is not welded may be formed at the joint portion between the torsion beam 4 and the inner flange portion 12a (or the outer flange portion 12b) to allow torsional deformation of the torsion beam 4. .
[0046]
Note that the present invention can be applied to a modified or changed embodiment without departing from the spirit of the present invention.
[0047]
For example, the first to third joining structures can be appropriately combined.
[0048]
[Brief description of the drawings]
FIG. 1 is a plan view of a suspension device for an automobile according to an embodiment.
FIG. 2 is a plan view showing details of the vicinity of an end portion of a torsion beam.
FIG. 3 is a side view showing details in the vicinity of the end portion of the torsion beam.
FIG. 4 is an enlarged view of FIG. 2;
5 is a view showing a first joining structure of the lower spring seat 12 and the torsion beam 4. FIG.
6 is a front view of FIG. 5. FIG.
7 is a view showing a second joining structure of the lower spring seat 12 and the torsion beam 4. FIG.
8 is a view showing a third joining structure of the lower spring seat 12 and the torsion beam 4. FIG.
9 is a cross-sectional view taken along the line XX in FIG.
[Explanation of symbols]
1 Trailing arm 2, 3 Wheel 4 Torsion beam 8 Connecting part 12 Lower spring seat 15 Damper 17 Bush L Interval

Claims (7)

In the torsion beam type rear suspension device,
A torsion beam connected between the left and right wheels;
A coil spring seat fixed to the end of the torsion beam;
Forming a reinforcing portion on the torsion beam corresponding to the joint portion of the coil spring sheet ;
The coil spring seat has a box shape having a rear flange portion standing at the rear end in the vehicle longitudinal direction and inner and outer flange portions standing at both ends in the vehicle width direction, and at least the rear flange portion An automobile suspension device, characterized in that the back surface of the torsion beam is joined to the front surface of the torsion beam in the longitudinal direction of the vehicle body .   2. The automobile suspension device according to claim 1, wherein the torsion beam has an inverted U-shaped cross section that opens downward, and an end edge of the lower opening of the coil spring seat is expanded compared to the other. 3. The automobile suspension device according to claim 1, wherein the reinforcing portion is formed at a location corresponding to a joint portion of the inner flange portion. 4. The reinforcing part is an automobile suspension apparatus according to any one of claims 1 to 3, characterized in that it is formed at positions corresponding to the bonding portion of the outer flange portion. A plate-like trailing arm extending from the torsion beam to a predetermined position in the longitudinal direction of the vehicle body and pivotally supported at the predetermined position;
Automotive suspension system according to any one of claims 1 to 4, characterized in that said coil spring seats are provided at predetermined intervals in the vehicle width direction from the trailing arm. 6. The automobile suspension apparatus according to claim 5 , further comprising a damper having a lower end pivotably supported at the predetermined interval. In the torsion beam type rear suspension device,
  A torsion beam connected between the left and right wheels;
  A coil spring seat secured to the end of the torsion beam;
  A plate-like trailing arm that extends from the torsion beam to a predetermined position in the longitudinal direction of the vehicle body and is pivotally supported at the predetermined position;
  The torsion beam and the coil spring seat are joined via means for allowing torsional deformation of the torsion beam,
  The coil spring seat is joined to one side surface of the torsion beam on the vehicle body front side,
  The coil spring seat is provided at a predetermined interval in the vehicle width direction from the trailing arm, and the lower end of the damper is pivotally supported at the predetermined interval.
  An automobile suspension apparatus, wherein a lower end portion of the damper is pivotally supported by a rod having one end connected to the trailing arm and the other end connected to the spring seat.

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