JP2003118623A - Steering knuckle structure of vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a steering knuckle of vehicle capable of efficiently improve strength and rigidity of a tie rod arm of the steering knuckle. SOLUTION: In root parts 8b of the tie rod arm 8 for a main body of steering knuckle 7, an overlay part 21 is arranged at an inside position α in a direction of width of the vehicle seen on a flat surface level so that the root part 8b of the tie rod arm 8 is set wider than the basic dimension width of the ball stud attachment part (a tip 8a of the tie rod arm 8) passing through a center line O of a ball stud 12 in straight line orthogonal to an axial line K of the tie rod arm 8 and is made larger than the ball stud attachment part.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a steering knuckle structure for a vehicle such as an automobile.
A vehicle having a tubular steering knuckle main body that rotatably supports wheels via bearings, and a tie rod arm to which a ball stud for connecting a tie rod is attached at a tip end portion of the steering knuckle main body is projected. The present invention relates to a steering knuckle structure.

[0002]

2. Description of the Related Art FIG. 4 shows a steering knuckle mounting portion of an automobile. In FIG. 4, reference numeral 1 is a brake disc, and 2 is a wheel (front wheel) (not shown) that is rotatably supported. Steering knuckles 3, 4, and 5 are tie rods, suspension struts, and suspension lower arms attached to the steering knuckle 2, and 6 is a drive shaft for driving front wheels.

The steering knuckle 2 is shown in FIGS.
As shown in FIG. 3, a steering wheel knuckle body 7 has a tubular steering knuckle body 7 (wheel support) that rotatably supports the front wheels via bearings (not shown). , A strut arm 9, a brake caliper arm 10, etc. are integrally projected. Further, a ball stud 12 for connecting a tie rod is attached to the nut 13 at the tip portion 8a of the tie rod arm 8.
(See FIG. 9) and the like, and one end of the tie rod 3 is rotatably attached to the ball stud 12. Thus, the steering force from the steering shaft (not shown) is transmitted to the front wheels (steering wheels) through the tie rod 3, the ball stud 12, the tie rod arm 8 and the steering knuckle 2 in order.

Further, the lower end portion of the suspension strut 4 is attached to the strut arm 9 of the steering knuckle 2, and the suspension lower arm 5 is attached to the ball stud 14 (see FIG. 5) fixed to the lower end portion of the steering knuckle 2. One end is rotatably connected. A brake caliper (not shown) can be attached to the brake caliper arm 10 of the steering knuckle 2.

By the way, loads are input to the tie rod arm 8 from various directions as indicated by arrows in FIGS. 5 and 6 (a) according to the cutting condition of the front wheels (steering operation of the tire). That is, the load (inner load) F ₁ from the inside of the vehicle corresponding to the tire turning angle is input from the direction shown by the angle range θ ₁ in FIGS. 5 and 6 (a), or the vehicle outside depending on the tire turning angle. The load (outer load) F ₂ from is input from the direction indicated by the angle range θ ₂ in FIGS. 5 and 6A.

As shown in FIG. 7, when the load input f ₁ to the tie rod arm 8 is in the direction β which intersects the tie rod arm axial direction α, the tip portion (ball stud mounting portion) 8a of the tie rod arm 8 and Tie rod arm 8
Intermediate part (arm intermediate part) 8c with the base part 8b of the
The bending moment mainly acts at. Further, as shown in FIG. 8, when the load input f ₂ to the tie rod arm 8 is parallel to the tie rod arm axial direction α, the tie rod arm 8 is twisted and bent from the base portion 8b of the tie rod arm 8. It becomes a mode.

[0007]

In such a steering knuckle structure, when the vehicle weight increases as the displacement of the automobile engine increases, the strength and rigidity of the tie rod arm 8 also increase accordingly. There is a need. As a means for this, it is conceivable to simply thicken the entire tie rod arm 8, but such means is not efficient (that is, if the tie rod arm 8 is simply thickened, the strength and rigidity are correspondingly improved. However, there is a problem in that the weight of the vehicle increases as the weight increases in the part that does not contribute to the improvement of strength and rigidity). There is a problem that the stud 12 has to be remade to have a new dimension and shape.

Here, in the above case, the ball stud 12
To briefly explain why we had to recreate,
It is as follows. First, the strength of the tie rod arm 8
In order to improve the rigidity, it is necessary to make the following dimensions and shapes in comparison with the conventional tie rod arm shape. That is, for the base portion 8b of the tie rod arm 8, the thickness of the base portion 8b (particularly, the dimension (wall thickness) in the vehicle width direction of the base portion 8b shown in FIG. Regarding the tip portion 8a, the thickness of the tip portion 8a (particularly, in FIG.
Dimension (wall thickness) in the vehicle up-down direction of the tip portion 8a indicated by
It is necessary to make T) thicker and to make the cross-sectional areas of these portions 8a and 8b larger than in the conventional case. In this case, since the root portion 8b of the tie rod arm 8 does not affect other components (interference, etc.), it is relatively easy to design the cross section to be larger and thicker than the conventional one.

On the other hand, the tip portion 8a of the tie rod arm 8
As for the tie rod arm 8, as shown in FIG. 11, the tie rod arm 8 is made thicker than the conventional one (see the chain line P in FIG. 11).
Indicates the size and shape of the tie rod arm 8 having the conventional thickness). When the ball stud 12 having the same size and shape as the conventional one is to be shared, the tip portion 8a of the tie rod arm 8 is cut and processed. A step-shaped portion (undercut-shaped portion) 15 as shown in FIG. 11 is produced. The reason is as follows. That is, the tip portion 8 of the tie rod arm 8 of the steering knuckle material M
The upper and lower surfaces of the portion corresponding to a are machined to form a machined surface N, and this portion is used as a ball stud mounting portion (see FIG. 10). On the other hand, in order to commonly use the ball stud 12 that has been used conventionally, the thickness T ′ of the tip portion 8a of the tie rod arm that is the ball stud mounting portion (see FIG.
It is necessary to cut (see 1) to the same thickness as the conventional one. Therefore, in order to make the tie rod arm 8 thicker than the conventional material (the material M having the dimension and shape shown by the one-dot chain line in FIG. 10) as the material thereof, when the ball stud mounting portion is cut, A pair of step-shaped portions (undercut-shaped surfaces) 15 are produced.
The shape indicated by the alternate long and short dash line P in FIG. 11 is a conventional tie rod arm shape having a thickness. Thus, the existence of the step-shaped portions 15 causes stress concentration in these step-shaped portions 15 and eventually causes a decrease in strength and rigidity of the tie rod arm 8. Therefore, in order to avoid such stress concentration, it is necessary to newly remake the ball stud and change the design so as to eliminate the stepped portion 15 as described above.

The present invention has been made in view of the above circumstances, and its main purpose is to steer a vehicle such that the strength and rigidity of a tie rod arm of a steering knuckle can be efficiently improved. To provide a knuckle structure.

[0011]

In order to achieve the above-mentioned object, the present invention has a tubular steering knuckle body for rotatably supporting wheels via bearings,
In a steering knuckle structure of a vehicle in which a tie rod arm to which a ball stud for connecting a tie rod is attached to a tip portion is projectingly provided on the steering knuckle body portion, in a plan view of a root portion of the tie rod arm with respect to the steering knuckle body portion. A padding portion is provided at an inner portion in the vehicle width direction, whereby the base portion of the tie rod arm passes through the center line of the ball stud and is orthogonal to the axis of the tie rod arm. The width is set to be wider than the basic dimension width, and the ball stud mounting portion is configured to be thicker. Further, in the present invention, a tie rod arm having a tubular steering knuckle body portion that rotatably supports a wheel via a bearing, and a ball stud for connecting a tie rod is attached to a tip portion of the steering knuckle body portion is projected to the steering knuckle body portion. In the steering knuckle structure of the vehicle, the padding portion extending between the intermediate portion of the tie rod arm and the ball stud mounting portion of the tie rod arm in a plan view is provided on the tie rod arm, whereby the meat is formed. The tie rod arm portion provided with the heap portion is configured to be thicker than the ball stud mounting portion. Further, in the present invention, the padding portions are provided on both sides of the ball stud mounting portion in plan view. Further, in the present invention, a tie rod arm having a tubular steering knuckle body portion that rotatably supports a wheel via a bearing, and a ball stud for connecting a tie rod is attached to a tip portion of the steering knuckle body portion is projected to the steering knuckle body portion. In the steering knuckle structure of the vehicle, the cross-sectional shape of the tip portion of the tie rod arm is such that the length in the vehicle vertical direction is longer than the length in the vehicle width direction, and the cross-sectional shape of the intermediate portion of the tie rod arm. 4 has a substantially square basic cross-sectional shape whose lengths in the vehicle width direction and the vehicle up-down direction are substantially equal to each other.
The two corners have a cross-sectional shape having an arc surface with a relatively large curvature radius, and the cross-sectional shape of the root portion of the tie rod arm is a cross-sectional shape having a length in the vehicle width direction longer than a length in the vehicle vertical direction. . Further, in the present invention, the tie rod arm is set such that the cross-sectional area increases in the order of the intermediate portion, the tip portion, and the root portion.

[0012]

DETAILED DESCRIPTION OF THE INVENTION An embodiment of the present invention will be described below with reference to FIGS. 1 to 3, the same parts as those in FIGS. 4 to 11 are designated by the same reference numerals, and overlapping description will be omitted.

FIG. 1 shows a first embodiment in which the present invention is applied to a steering knuckle structure of an automobile.
As shown in FIG. 1A, a steering knuckle 20 according to the present embodiment is an automobile part (integrally molded product) formed by projecting a tie rod arm 8, a strut arm 9, a brake caliper arm 10 and the like on a steering knuckle body 7. ) And the tip portion 8a of the tie rod arm 8 that is the ball stud attachment portion (the tip portion 8a of the tie rod arm 8 is the ball stud attachment portion), and the dimensional shape of the base portion 8b of the tie rod arm 8. Different from the case of the product, these parts 8a,
8b has a specific shape and is thicker than the conventional product.

Specifically, as shown in FIG. 1 (b), the root portion 8b of the tie rod arm 8 with respect to the steering knuckle body portion 7 has an inner portion α of the root portion 8b in the vehicle width direction in plan view. The first padding portion 21 is provided on the tie rod 8 so that the base portion 8b of the tie rod arm 8 serves as a ball stud mounting portion.
It is thicker than the basic cross section (basic dimensions) of the tip portion 8a. That is, the width of the base portion 8b of the tie rod arm 8 is in the direction passing through the center line O of the ball stud 12 attached to the tip portion 8a of the tie rod arm 8 and orthogonal to the axis K of the tie rod arm 8. Basic width W of the mounting part (Fig. 1
(See (b)), so that the base portion 8b is thicker than the tip portion 8a which is the ball stud mounting portion. The base part 8
The padding portion b is not provided at the outer side portion β in the vehicle width direction in a plan view, and has the same shape as the conventional product.

Further, as shown in FIG. 1B, the tip portion 8a of the tie rod 8 has a tie rod arm 8 in plan view.
The second portion extending between the intermediate portion 8c and the tip portion 8a (the ball stud attachment point γ of the tie rod arm 8).
Of the tip portion 8a of the tie rod arm 8 which is the tie rod arm portion on which the second padding portions 22a and 22b are provided. It is thicker than the basic cross section of the ball stud mounting portion (the cross section of the basic dimension width W shown in FIG. 1B). In the present embodiment, the second padding portions 22a and 22b described above have substantially symmetrical shapes that project in a curved shape (for example, an arc shape) in the vehicle width direction, and are viewed in a plan view. They are provided on both sides of the ball stud attachment point γ or the tip portion 8a which is the ball stud attachment portion.

According to the steering knuckle structure thus constructed, the first and second padding portions 21, 22a are formed.
Since the tie rod arms 8 and 22b are provided with only the necessary portions (the portions that effectively increase the strength and rigidity) thickened, it is possible to efficiently improve the strength and rigidity. Therefore, the increase in weight can be minimized. Specifically, by providing the first padding portion 21, the strength and rigidity with respect to the load in the direction perpendicular to the tie rod arm axis are improved, and the second padding portion 2 is provided.
By providing 2a and 22b, the strength and rigidity with respect to the load in the direction parallel to the tie rod arm axis are improved.
Further, since the thickened portion of the tie rod arm 8 is limited as described above, the machined surface N of the tip portion 8a, which is the ball stud mounting portion, may be formed in the conventional manner. Therefore, the ball stud 12 used conventionally is remade. It is possible to use (shared) without any change.

2 and 3 show a steering knuckle 30 according to a second embodiment of the present invention. The above-described first embodiment is designed to provide a steering knuckle structure according to the present invention by modifying the design of an existing mass-produced product (steering knuckle), while the present embodiment is newly added. Steering knuckle 30
It is an embodiment when designing.

In this embodiment, the cross section of the tip portion 8a, the intermediate portion 8c, and the root portion 8b of the tie rod arm 8 is shown in FIG. , (B) and (c), the shape is set to be increased in the effective direction. More specifically, the cross-sectional shape of the tip portion 8a of the tie rod arm 8 is set in the vehicle vertical direction rather than in the vehicle width direction as shown in FIG. 3A to prevent bending moment of the arm axial load. The cross-section has a long length. In addition, the middle portion 8c of the tie rod arm 8
In order to prevent the torsion of the load in the direction perpendicular to the arm axis, the cross-sectional shape of is a substantially square basic cross-sectional shape whose lengths in the vehicle width direction and the vehicle vertical direction are substantially equal to each other as shown in FIG. The four corners have a cross-sectional shape having an arcuate surface R having a relatively large curvature radius. Further, the cross-sectional shape of the base portion 8b of the tie rod arm 8 is shown in FIG.
As shown in (c), the cross-sectional shape is longer in the vehicle width direction than in the vehicle vertical direction. In the present embodiment, the cross-sectional area is set to increase in the order of the intermediate portion 8c, the tip portion 8a, and the root portion 8b.

In the case of such a construction, unlike the case of the above-described first embodiment, the ball stud 12 is newly made to correspond, and the strength and rigidity of the tie rod arm 8 are improved with a minimum weight increase. It is possible to

Although one embodiment of the present invention has been described above, the present invention is not limited to this embodiment.
Various modifications and changes can be made based on the technical idea of the present invention. For example, the root portion 8b of the tie rod arm 8
The first built-up portion 21 provided on the inner side of the tie rod arm 8 is an inner side portion α in the vehicle width direction of the tie rod arm 8 in plan view, and
It may have any shape as long as it extends between the intermediate portion 8c of the tie rod arm 8 and the steering knuckle body 7. In addition, the second padding portion 22a provided on the side of the tip portion 8a of the tie rod arm 8,
The shape of 22b does not necessarily have to be an arc shape in a plan view, and may be any shape as long as it is a build-up shape that extends between the tip portion 8a and the intermediate portion 8c of the tie rod arm 8. .

[0021]

According to the first aspect of the present invention, a padding portion is provided at an inner portion of the tie rod arm with respect to the steering knuckle main body portion in the vehicle width direction in a plan view, whereby the root portion of the tie rod arm is provided. Is set wider than the basic dimension width of the ball stud mounting portion in a straight line direction that passes through the center line of the ball stud and is orthogonal to the axis of the tie rod arm, and is configured to be thicker than the ball stud mounting portion. Therefore, the presence of the above-mentioned built-up portion can improve the strength / rigidity (impact strength) against a load in the direction perpendicular to the tie rod arm axis. Further, according to the present invention, the tie rod arm is not simply thickened as a whole, but the built-up portion is provided only in a portion necessary for improving strength and rigidity, and only that portion is thickened. Can be minimized.

According to a second aspect of the present invention, the intermediate portion of the tie rod arm (the portion between the tip portion and the base portion, which is the ball stud attachment portion) and the ball stud attachment portion of the tie rod arm in plan view. The tie rod arm is provided with a build-up portion that extends across the tie rod arm, and the tie rod arm portion where the build-up portion is provided is made thicker than the ball stud mounting portion. As a result, it is possible to improve strength and rigidity (impact strength) against a load in a direction parallel to the tie rod arm axis. Further, even if the above-mentioned build-up portion is provided, the thickness dimension of the mounting seat surface of the ball stud mounting portion does not change, so there is no need to remake the ball stud.
Therefore, the ball studs that have been conventionally used can be used as they are, and the ball studs can be shared or shared. Further, since the built-up portion is provided in the above-mentioned portion, it is possible to avoid the built-up portion from interfering with other parts.

Further, according to the present invention as defined in claim 3, since the built-up portions are provided on both sides of the ball stud mounting portion in plan view, the load is not biased to one side only, and the ball stud is not biased. Since both sides of the mounting portion bear the load, it is possible to prevent stress concentration on the tie rod arm.

Further, the present invention according to claim 4 has a tie rod having a cylindrical steering knuckle main body for rotatably supporting a wheel via a bearing, and a ball stud for connecting a tie rod is attached to a tip portion thereof. In a steering knuckle structure for a vehicle in which an arm is provided so as to project from a steering knuckle body, a cross-sectional shape of a tip portion of a tie rod arm is a cross-sectional shape in which a vehicle vertical direction length is longer than a vehicle width direction length. The cross-sectional shape of the intermediate portion is a substantially square basic cross-sectional shape whose lengths in the vehicle width direction and the vehicle up-down direction are substantially equal to each other, and the four corners have an arc surface with a relatively large curvature radius. The cross section of the base of the tie rod arm is longer than the length in the vehicle vertical direction. Therefore, the bending moment of the arm axial load at the tip part of the tie rod arm, the twisting measure of the arm axis vertical direction load at the middle part of the tie rod arm, and the arm axis vertical load load at the root part of the tie rod arm Bending moment countermeasures can be taken, and the strength and rigidity of the tie rod arm can be improved.

Further, according to the present invention as set forth in claim 5, the tie rod arm is set so that the cross-sectional area increases in the order of the intermediate portion, the tip portion and the root portion.
When making a new ball stud, the strength and rigidity of the tie rod arm can be improved with a minimum increase in weight.

[Brief description of drawings]

FIG. 1 is a first steering knuckle structure according to the present invention.
1 shows an embodiment, FIG. 1 (a) is a side view of a steering knuckle, and FIG. 1 (b) is an enlarged sectional view taken along the line AA in FIG. 1 (a).

[2] The second steering knuckle structure according to the present invention
FIG. 3 is a side view of the steering knuckle, for explaining the embodiment. FIG.

3 (a) is an enlarged sectional view taken along line XX in FIG. 2, FIG. 3 (b) is an enlarged sectional view taken along line YY in FIG. 2, and FIG. 3 (c) is taken along line ZZ in FIG. It is a line expansion sectional view.

FIG. 4 is a perspective view showing a steering knuckle arrangement portion of an automobile.

FIG. 5 is a perspective view of a steering knuckle that has been conventionally used.

6A is a plan view of the steering knuckle viewed from a direction indicated by an arrow H in FIG. 5, for explaining a load input to the tie rod arm via the ball stud. FIG. 6B is a sectional view taken along line BB in FIG.

FIG. 7 is a plan view of a steering knuckle showing a deformation mode of the tie rod arm when a load is input to the tie rod arm via a ball stud from a direction perpendicular to the tie rod arm axis.

FIG. 8 is a side view of the steering knuckle showing a deformation mode of the tie rod arm when a load is input to the tie rod arm via a ball stud from a direction parallel to the tie rod arm axis.

FIG. 9 is a cross-sectional view showing a mounted state of a ball stud at a tip portion of a tie rod arm.

FIG. 10 is a side view of the ball stud mounting portion after cutting the ball stud mounting portion at the tip portion of the tie rod arm.

FIG. 11 is a side view showing the shape of the tip portion of the tie rod arm after cutting the ball stud mounting portion at the tip portion of the tie rod arm when the overall size of the tie rod arm is increased.

[Explanation of symbols]

7 Steering knuckle body 8 Tie rod arm 8a Tip part that is a ball stud mounting part 8b Base part 8c middle part 20 steering knuckle 21 First padding part 22a, 22b Second padding part 30 steering knuckle K Tie rod arm axis O Stud bolt center line W basic dimension width α Inside of vehicle width direction γ Ball stud mounting location

Claims (5)

[Claims] 1. A steering knuckle body having a cylindrical steering knuckle body for rotatably supporting a wheel via a bearing, and a ball stud for connecting a tie rod attached to a tip portion of the steering knuckle body. In the steering knuckle structure of the vehicle consisting of, of the root portion of the tie rod arm with respect to the steering knuckle body portion, a buildup portion is provided at an inner portion in the vehicle width direction in a plan view, whereby the root portion of the tie rod arm is provided. It is configured to be wider than the basic dimension width of the ball stud mounting portion in a straight line direction passing through the center line of the ball stud and orthogonal to the axis line of the tie rod arm, and configured to be thicker than the ball stud mounting portion. The steering knuckle structure of the vehicle characterized by. 2. A steering knuckle body having a tubular steering knuckle body for rotatably supporting a wheel via a bearing, and a ball stud for connecting a tie rod attached to a tip portion of the steering knuckle body. In the steering knuckle structure of a vehicle comprising the above, the tie rod arm is provided with a build-up portion extending across an intermediate portion of the tie rod arm and a ball stud mounting portion of the tie rod arm in plan view, whereby the build-up portion is provided. The steering knuckle structure for a vehicle according to claim 1, wherein a tie rod arm portion provided with a portion is configured to be thicker than the ball stud mounting portion. 3. The steering knuckle structure for a vehicle according to claim 2, wherein the padding portions are provided on both sides of the ball stud mounting portion in a plan view. 4. A steering knuckle body having a tubular steering knuckle body for rotatably supporting a wheel via a bearing, and a ball stud for connecting a tie rod attached to a tip end portion of the steering knuckle body. In the steering knuckle structure of the vehicle configured as described above, the cross-sectional shape of the tip portion of the tie rod arm is a cross-sectional shape in which the length in the vehicle up-down direction is longer than the length in the vehicle width direction, and the cross-sectional shape of the intermediate portion of the tie rod arm is A quadrangular basic cross-sectional shape whose lengths in the vehicle width direction and the vehicle up-down direction are substantially equal to each other, and in which the four corners have an arc surface with a relatively large curvature radius, The cross-sectional shape of the root portion is a cross-sectional shape in which the length in the vehicle width direction is longer than the length in the vehicle vertical direction, The steering knuckle structure of the vehicle characterized by. 5. The steering knuckle structure for a vehicle according to claim 4, wherein the tie rod arm is set so that its cross-sectional area increases in the order of an intermediate portion, a tip portion, and a root portion.