JP2003002027A - Front suspension structure for automobile - Google Patents

Abstract

PROBLEM TO BE SOLVED: To miniaturize a ball joint, prevent caster trail reduction during steering and play of the ball joint against load input, and improve durability against reaction force of a damper while reconciling improving collar attachment accuracy to a support part of a wheel support and preventing reduction of collar strength by arranging ball parts of two ball joints at an upper part of a suspension arm support part of a wheel support. SOLUTION: The ball parts of the two ball joints 13, 14 are closely arranged at the upper part of the suspension arm support part 12d of the wheel support 21 formed by casting. A collar 34 formed by forging is arranged at an opening part for fixing the ball joint arranged on the support part 12d. An outer part of the collar 34 is worked and an inner taper part is formed by only forging.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a front suspension structure for an automobile of a double pivot type in which two ball joints are provided at a connecting portion between a wheel support (knuckle) and a suspension arm.

[0002]

2. Description of the Related Art Conventionally, a double wishbone type front suspension has an upper arm 82 for swingably supporting a front wheel 81 (wheel) to a vehicle body or a suspension cross member via a wheel support as shown in a front view of FIG. And a lower arm 83, and the upper arm 8
2, an upper ball joint 84 at the outer side end of the vehicle body,
An imaginary kingpin shaft 86 that connects the lower ball joint 85 to the outer end of the lower arm 83 is formed, and the kingpin shaft 86 contacts the road surface 87 when the vehicle body is viewed from the front, and the tire centerline (wheel centerline). A kingpin offset 89 as shown in FIG. 8 is set between the point 88) contacting the road surface 87.

In this case, as shown in the plan view of FIG. 9, during braking, a rearward force is applied to the front wheel 81 around the grounding point of the tire as indicated by an arrow a in the figure, and in relation to the kingpin shaft 86. The front wheel 81 becomes toe-out as shown by an imaginary line b in FIG. 9, and the sense of stability deteriorates.

In order to eliminate such toe-out during braking, the lower ball joint 85 shown in FIGS. 8 and 9 is used.
Although it is better to shift the position of the above to the outside of the tire center line 88, a braking device such as a brake disc and a caliper is present in the front wheel 81, so that the lower ball joint 85
It is impossible to shift the position of (1) to the inside of the front wheel 81.

Therefore, as a means for eliminating the toe-out at the time of braking, the upper arm 82 is formed to have a short shape, as shown in FIG.
Although it is conceivable to configure a kingpin axis as indicated by the dotted line c, if the above-mentioned upper arm 82 is set to be extremely short, the camber will change or become excessive.

By the way, in the front suspension structure of the double pivot type automobile, the above problems can be solved by suitably setting the kingpin offset.

That is, as shown in FIG. 10, a lower arm 90 having a lateral link structure for supporting a front wheel 81 on a suspension cross member or a vehicle body via a wheel support, and a lower arm 91 having a compression link structure.
When the ends of the two lower arms 90, 91 on the outer side of the vehicle body are connected to the wheel support by two ball joints 92, 93, the lower arms 90, 91 are extended in extra war on the outer side of the vehicle body. An intersection point 94 is formed, and this intersection point 94 through which the kingpin axis passes is located outside the tire center line 88, so that the toe-out during braking can be eliminated and the toe-in during braking can be achieved.

However, this double-pivot type front suspension structure has the following problems. That is, the virtual kingpin axis 95 (see FIG. 11)
When the front wheels 81 are steered around as shown by the phantom line in the figure, the above-mentioned intersection point 94 moves rearward as shown by the phantom line d in FIG. When this intersection point 94 moves rearward, the caster trail 97 (self-definition) as the distance between the point where the kingpin axis 95 shown in the side view in FIG. 11 crosses the road surface 87 and the point where the tire center line 96 intersects with the road surface 87. The trail which contributes to the aligning torque) decreases, and the steering wheel return becomes worse.

Particularly, when the span between the two ball joints 92 and 93 shown in FIG. 10 is large, the displacement amount of the intersection point 94 becomes large, and the retreat amount of the intersection point 94 at the time of steering becomes excessively large, and the caster trail 97 is greatly reduced. The handle return error becomes noticeable.

In order to solve such a problem, 2
It is desirable to make the distance between the two ball joints 92, 93 as close as possible. That is, as shown in FIG. 12, in the lower arm support portion 98a of the wheel support 98, one ball joint 93 has its ball portion supported by the support portion 9a.
8a and the ball joint 92 on the other side is fixed to the ball portions 92a and 93b of the ball joints 92 and 93 with nuts 99 and 99 so that the ball portion is located below the support portion 98a. The ball joints 92 and 93 can be arranged close to each other. Note that FIG.
In FIG. 2, 90a is an end of the lower arm 90 on the outer side of the vehicle body, and 91a is an end of the lower arm 91 on the outer side of the vehicle body.
Reference numeral 0 is a rubber seal as a seal member.

However, in the double-pivot type front suspension structure shown in FIG. 12, the lower arm 90 on the lateral link side, which is involved in determining the roll center.
Since the damper is attached to the ball joint via the damper fork, a strong reaction force from the damper and the damper fork acts on the ball joint 92 via the lower arm 90 when the front wheel 81 is pushed up. There was a problem that it could not secure sufficient proof strength.

In order to improve the proof stress against the reaction force from the above-mentioned damper, two ball joints 92 and 93 are used.
It is conceivable that all of the spherical parts of the above are arranged side by side above the lower arm support part 98a of the wheel support 98. In this case, the ends 90 of the lower arms 90, 91 on the outer side of the vehicle body.
It is necessary to avoid mutual interference between a and 91a and ball joints 92 and 93.

In order to avoid such mutual interference, the ball joint 9 with the stud bolt having a predetermined diameter maintained.
When the balls 2 and 93 are separated, both ball joints 92 and 9
Since the span between three becomes large and the caster trail 97 decreases due to the backward movement of the intersection 94 during steering, it is necessary to reduce the diameters of the hole joints 92, 93 and their stud bolts to avoid mutual interference.

In this way, the ball joints 92, 93
In the case of downsizing the wheel support 98, the surface pressure of the lower arm support portion 98a of the wheel support 98 becomes high, the support portion 98a deteriorates, and rattling between the ball joints 92 and 93 occurs. It was

[0015]

SUMMARY OF THE INVENTION According to the present invention, the ball portions of two ball joints are arranged close to each other on the upper portion of the suspension arm support portion of the wheel support formed by casting, while the balls provided on the support portion are provided. A collar formed by forging is provided in the opening for fixing the joint, the collar is processed on the outside, and the internal taper is left as forged to improve the accuracy of mounting the collar to the support part of the wheel support. It is possible to reduce the size of the ball joint while achieving both the strength of the collar and prevention of deterioration of the strength of the collar. In addition, the caster trail during steering can be reduced.
An object of the present invention is to provide an automobile front suspension structure capable of preventing (backward) movement, preventing rattling of a ball joint against a load input, and improving resistance to a reaction force from a damper. .

[0016]

A vehicle front suspension structure according to the present invention is a double pivot type vehicle front suspension structure in which two ball joints are provided in a connecting portion between a wheel support and a suspension arm. While placing the ball parts of the two ball joints on the upper part of the suspension arm support part of the wheel support formed by casting,
A collar formed by a forged product is set in an opening for fixing a ball joint provided in the support portion, the collar is processed on the outside, and the inner tapered portion is forged only. The suspension arm configured as described above can be set to the lower arm, and the suspension arm support portion of the wheel support can be set to the lower arm support portion.

According to the above construction, since the collar is processed on the outside thereof, it is possible to improve the mounting accuracy of the wheel support to the supporting portion. Further, since the inner taper portion of the collar is formed by forging in other words, only the forging process is performed, so that the strength of the collar can be prevented from lowering.

That is, when a metal is forged, content defects such as voids and eccentricities disappear, a fibrous structure (metal flow) is formed, and mechanical strength and toughness are improved. The part is only forged by the above-mentioned improved strength and toughness.

Since the ball joints are arranged close to each other while the size of the ball joints is reduced, it is possible to prevent the caster trail from being reduced at the time of steering, and by mounting the ball joints on the collar of the forged product, it is possible to cope with the load input. It is possible to prevent the rattling of the ball joint, and the ball parts of the two hole joints are located above the suspension arm support part of the wheel support, and the ball joint is made by forging only. By attaching to the, it is possible to improve the proof stress against the input from the damper.

In one embodiment of the present invention, the suspension arm includes a lateral link side arm and a compression link side arm arranged in the vehicle width direction, and corresponds to the lateral link side ball joint. Forged product color is provided.

According to the above construction, the forged product collar can be provided only on the ball joint side for the lateral link side suspension arm which is arranged in the vehicle width direction and to which a high load is inputted, and the suspension on the compression link side. The above collar can be omitted on the side of the ball joint for the arm.

[0022]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described in detail below with reference to the drawings. The drawing shows a double wishbone type front suspension structure of an automobile. In FIG. 1, a wheel inner panel 2 which constitutes an outer wall of an engine room 1 is provided, and a suspension tower portion 3 is integrally formed on an upper portion of the wheel inner panel 2. A front fender panel 4 is attached to the outside of the suspension tower portion 3 by being integrally formed.

Further, a front side frame 5 having a closed cross section structure extending in the front-rear direction of the vehicle is provided at the lower portion of the wheel inner panel 2, and a front side frame 5 as a vehicle body rigid member is provided with a rubber mount 6 as an elastic body. The suspension cross member 7 is supported. On the other hand, the front wheel 1 including the wheel disc 8 and the tire 9
0 (wheel) is provided, and a wheel support 12 is provided on the wheel hub 11 (see FIG. 3) via a bearing.

The wheel support 12 is made of a cast product, and the wheel support 12 is a front wheel 10.
Rotatably supporting the high mount upper arm 12a extending upward as shown in FIG.
And an extension portion 12b for connecting a tie rod extending rearward,
An extension portion 12c for connecting the lower arm extending downward is provided.

A lower arm support portion 12d, which is substantially horizontal and extends in the vehicle width direction, is integrally formed by casting at the lower end portion of the above-mentioned extension portion 12c. The lower arm support portion 12d is provided with lower arms 15 via ball joints 13 and 14. 1
Ends 15a, 16a (see FIG. 5) on the outer side of the vehicle body 6 are connected.

The front lower arm 15 of the above-mentioned two lower arms 15 and 16 is composed of a lateral link extending laterally, and the end portion of the lower arm 15 on the inner side of the vehicle body is shown in FIGS. Thus, the suspension cross member 7 is swingably supported via the lower arm bush 17 as an elastic body.

Of the two lower arms 15 and 16 described above, the lower arm 16 on the rear side is composed of a compression link, and the lower arm 16 extends obliquely rearward,
As shown in FIG. 2, an end of the lower arm 16 on the inner side of the vehicle body is swingably supported by the suspension cross member 7 via a lower arm bush 18 as an elastic body.

That is, by supporting the lower arms 15 and 16 with respect to the suspension cross member 7 which is rubber-mounted on the front side frame 5, the road noise input from the lower arms 15 and 16 and the suspension cross-member 7 is supplied to the rubber mount 6. The part is configured to cut off.

On the other hand, as shown in FIGS. 1 and 4, the end of the high mount upper arm 20 on the outer side of the vehicle body is connected to the upper end of the extension 12a of the wheel support 12 via a ball joint 19. .

The above-mentioned upper arm 20 is composed of an A-shaped arm, and an end portion of the upper arm 20 on the inner side of the vehicle body is, as shown in FIGS. 2 and 4, an upper arm bush 21 as an elastic body and a bracket (not shown). ), And is swingably supported by the wheel inner panel 2.

A damper 22 is stretched between the lower arm 15 and the suspension tower portion 3 as shown in FIG. The damper 22 includes a damper fork 23 whose lower end is rotatably supported at an intermediate portion of the lower arm 15, and a coil spring 26 stretched between an upper seat 24 and a lower seat 25.

Further, as shown in FIG. 2, a tie rod 28 is connected to the rear portion of the extension 12b of the wheel support 12 via a ball joint 27, and the tie rod 28 and the gear rack 29 are connected via a ball joint 30. Are connected together and each element 29, 30, 28, 27, 1 is operated by operating a steering wheel (so-called steering wheel).
The front wheel 10 is configured to be steered around the kingpin axis via the wheels 2b and 12.

In FIG. 3, reference numeral 31 is a control link, 32 is a stabilizer, and the stabilizer 32 suppresses the roll angle at the time of rebounding by bumping only one wheel by the resistance of torsional rigidity. Further, in the figure, F indicates the front of the vehicle.

FIG. 5 shows a double pivot type connection structure of the ends 15a and 16a of the lower arms 15 and 16 on the outer side of the vehicle body and the lower arm support portion 12d of the wheel support 12, in which the lower arm support portion 12d has two parts. Openings 33, 33 for fixing the ball joints are formed corresponding to the one ball joint 13, 14. Collars 34, 34 as strength members formed by forging are provided in the above-mentioned openings 33, 33, respectively.

As shown in FIG. 6, the collar 34 has a taper portion 34a formed therein for allowing the stud bolts 13a, 14a having the taper shafts of the hole joints 13, 14 to pass therethrough. In other words, 34a is left as forged in other words.

That is, since the mechanical strength and toughness are improved by forging a metal, the tapered portion 34a is not subjected to any cutting work, and the improved mechanical strength and toughness are maintained. Therefore, the tapered portion 34 described above
Since the precision of a is required to be obtained only by the forging process, the precision forging device is used as the forging device of the collar 34.

On the other hand, the outer portion 34b of the collar 34 is subjected to processing such as cutting in order to secure the accuracy of attachment to the opening 33 after forging. The ball joints 13 and 14 described above have stud bolts 13a and 14a and spheres 13b and 14b, and the two support joints 13 and 14 are provided above the lower arm support portion 12d of the wheel support 12 formed by casting. Each ball 13
These two ball joints 13 and 14 are juxtaposed and attached to the lower arm support portion 12d via the above-mentioned collars 34 and 34 so that b and 14b are arranged close to each other.

That is, the nut 35 is tightened on the threaded portions of the stud bolts 13a and 14a protruding from the taper portion 34a of the collar 34 to the lower portion of the lower arm support portion 12d,
The two ball joints 13 and 14 are attached to the lower arm support portion 12d, and the lower arms 15 and 1 are attached to the spherical portions 13b and 14b located above the lower arm support portion 12d.
The outer end portions 15a and 16a of the vehicle body 6 are attached.
In the figure, 36 is the end portion 15 of the lower arm 15, 16.
a, 16a is a rubber seal as a seal member interposed between the lower surface of the collar 16a and the upper surface of the collar 34.

As described above, the vehicle front suspension structure of the embodiment shown in FIGS. 1 to 6 has the wheel support 12 and the suspension arms (lower arms 15, 16).
2 ball joints 13 and 14 at the connecting part with
Is a front suspension structure of a double-pivot type vehicle provided with a ball support of two ball joints 13 and 14 above a suspension arm support portion (see lower arm support portion 12d) of a wheel support 12 formed by casting. While arranging the parts 13b and 14b close to each other, collars 34 and 34 formed by forging are set in the openings 33 and 33 for fixing the ball joint, which are provided in the support part 12d, and the collar 34 is the outside thereof. Three
4b is processed, and the internal tapered portion 34a is forged only. . According to this configuration, the collar 34 is processed on the outside 34b thereof, so that the mounting accuracy of the wheel support 12 to the support portion 12d can be improved. Further, since the taper portion 34a inside the collar 34 is left as forged in other words, only the forging process is performed, so that the strength of the collar 34 can be prevented from lowering.

That is, when a metal is forged, content defects such as voids and eccentricities disappear, a fibrous structure (metal flow) is formed, and mechanical strength and toughness are improved. The tapered portion 34a is formed by only the forging process in which the strength and toughness are improved.

Since the ball joints 13 and 14 are downsized and the two ball joints 13 and 14 are arranged as close to each other as possible by this downsizing, the caster trail during steering around the kingpin axis of the front wheel 10 is reduced. It is possible to prevent the occurrence of rattling of the ball joints 13 and 14 against the load input by attaching the ball joints 13 and 14 to a portion of the collar 34 of the forged product which has strength and toughness that is formed only by forging. It is possible to prevent the two hole joints 13,
14 ball portions 13b, 14b are arranged above the suspension arm support portion (see lower arm support portion 12d) of the wheel support 12, and the ball joints 13, 14 are provided.
The taper part 3 inside the collar 34, which is formed by forging only
By attaching to 4a, it is possible to improve the proof stress against the input from the damper 20 and the damper fork 23.

FIG. 7 shows another embodiment of the front suspension structure of an automobile. In the previous embodiment shown in FIG. 5, each ball joint 13 for the lower arm 15 on the lateral link side and the lower arm 16 on the compression link side is shown. , 14 corresponding to the forged collar 34,
In this embodiment shown in FIG. 7, the forged collar 34 is provided only for the ball joint 13 of the lower arm 15 on the lateral link side arranged in the vehicle width direction.

That is, the lower arm 1 on the lateral link side
Since the forged product collar 34 is not provided on the side of the ball joint 14 for the lower arm 16 on the side of the compression link where the load input is lower than that of the stud 5, the stud is attached to the ball joint 14 mounting portion of the lower arm support portion 12d of the wheel support 12. A tapered opening 37 corresponding to the shape of the bolt 14a is formed.

As described above, in the vehicle front suspension structure shown in FIG. 7, the suspension arms (see lower arms 15 and 16) are the lateral link side arm 15 and the compression link side arm which are arranged in the vehicle width direction. 16 and the forged collar 34 is provided corresponding to only the ball joint 13 for the arm 15 on the side of the lateral link.

According to this structure, the lower arm 1 on the lateral link side, which is arranged in the vehicle width direction and receives a high load, is inputted.
Forged collar 34 only on the side of the ball joint 13 for 5
Can be provided, and the collar 34 can be omitted on the side of the ball joint 14 for the lower arm 16 on the compression link side, which can reduce the number of assembling steps and the cost of the entire front suspension. .

Instead of the structure of FIG. 7, the ball joint 1 for the lower arm 16 on the compression link side.
The forged product collar 34 may be provided on the fourth side as well, and in this case, the tapered portion 34b of the collar 34 may be configured to improve accuracy by cutting.

In the correspondence between the configuration of the present invention and the above-described embodiment, the suspension arm of the present invention corresponds to the lower arms 15 and 16 of the embodiment, and similarly, the suspension arm support portion is the lower arm support portion 12d. The inner taper portion of the collar corresponds to the taper portion 34a, the lateral link side arm corresponds to the lower arm 15, and the compression link side arm corresponds to the lower arm 16. It is not limited to the configuration of the embodiment.

[0048]

According to the present invention, the ball portions of the two ball joints are arranged close to each other on the upper portion of the suspension arm supporting portion of the wheel support formed by casting, while the ball joint fixing provided on the supporting portion is fixed. By providing a collar formed of a forged product in the opening for use, processing the outside of the collar and leaving the inner tapered portion as forged, the accuracy of mounting the collar to the support portion of the wheel support is improved, It is possible to reduce the size of the ball joint while preventing the strength of the collar from decreasing, and at the same time, it is possible to prevent the caster trail from decreasing during steering, and the rattling of the ball joint against the load input occurs. This has the effect of preventing it and improving the proof stress against the reaction force from the damper.

[Brief description of drawings]

FIG. 1 is a skeleton diagram showing a front suspension structure of an automobile according to the present invention.

FIG. 2 is a skeleton diagram as seen from a plane.

FIG. 3 is a perspective view of a double wishbone front suspension.

FIG. 4 is a perspective view of a peripheral portion of an upper arm.

FIG. 5 is an enlarged sectional view of a double pivot portion.

FIG. 6 is an enlarged sectional view of a forged product collar.

FIG. 7 is a cross-sectional view showing another embodiment of the front suspension structure for an automobile of the present invention.

FIG. 8 is a schematic front view showing a conventional front suspension.

FIG. 9 is a schematic plan view for explaining a toe-out by a conventional front suspension.

FIG. 10 is a schematic plan view for explaining a problem of a double pivot type suspension.

FIG. 11 is a schematic side view of the same.

FIG. 12 is a sectional view showing a conventional ball joint mounting structure.

[Explanation of symbols]

12 ... Wheel support 12d ... Lower arm support part (suspension arm support part) 13, 14 ... Ball joint 13b, 14b ... Ball part 15, 16 ... Lower arm (suspension arm) 33 ... Opening part 34 ... Collar 34a ... Tapered part (internal taper) Part) 34b ... external

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Tadashi Yoshimura             3-1, Shinchi, Fuchu-cho, Aki-gun, Hiroshima Prefecture Mazda             Within the corporation F term (reference) 3D001 AA17 AA42 BA32 DA04 DA05

Claims (2)

[Claims] 1. A front suspension structure for an automobile of a double pivot type in which two ball joints are provided at a connecting portion between a wheel support and a suspension arm, wherein the suspension arm supporting portion of the wheel support is made of a cast product. The balls of the two ball joints are arranged close to each other on the upper part, and a collar formed by forging is set in the opening for fixing the ball joint provided in the support part, and the collar is processed on the outside. , The front taper part of the car is made by forging only. 2. The suspension arm includes a lateral link side arm and a compression link side arm arranged in the vehicle width direction, and a forged collar is provided corresponding to the lateral link side ball joint. The front suspension structure for an automobile according to claim 1.