Patent ID: 12246787

DESCRIPTION OF EMBODIMENTS

Hereinafter, an embodiment of the invention will be described in detail.

FIG.1is a front view (a view seen from a vehicle side) of a support structure20for vehicle according to the present embodiment.FIG.2is a right side view of the support structure20for vehicle.FIG.3is a perspective view of the support structure20for vehicle.

The support structure20for vehicle (steering knuckle: hereinafter, simply referred to as knuckle) according to the present embodiment is made of aluminum, and is cast mainly by a gravity casting method.

FIGS.1to3show the knuckle20for a wheel which is a right front wheel. The knuckle for a left front wheel has a shape symmetrical to the knuckle20shown inFIG.1.

Since a basic structure and function of the knuckle20are known, they will be briefly described below.

As shown inFIG.3, the knuckle20has a recessed body portion22whose bottom portion is located on a wheel attachment portion side. A shaft hole21into which an axle of the wheel is rotatably fitted is formed in the center of the bottom surface of the recess of the body portion22. Four bolt holes22a,22b,22c,22dto which bolts of a wheel hub (not shown) serving as a wheel support are screwed and joined are formed in a bottom portion of the body portion22around the shaft hole21.

A plurality of support arms to which various members are connected extend from the body portion22.

A damper attachment portion24to which a damper (not shown) of a suspension is connected is formed at a distal end portion of a support arm24aextending to an upper portion of the body portion22.

A tie-rod attachment portion26to which a tie rod (not shown) for transmitting a steering force from a steering wheel (not shown) is connected is formed at a distal end portion of a support arm26aextending from the body portion22to any one of the front and rear directions of the vehicle (the rear side of the vehicle inFIG.1).

A lower arm attachment portion28to which a lower arm (not shown), which is a control arm of the suspension, is connected is formed in a lower portion of the body portion22.

Attachment holes30aand30bfor attaching a brake caliper (not shown) are formed in a side surface portion of the body portion22opposite to the tie-rod attachment portion26.

A first rib32connecting the damper attachment portion24with the tie-rod attachment portion26is formed between the damper attachment portion24and the tie-rod attachment portion26. The first rib32has a required height and a required width when viewed from the bottom surface of the body portion22.

A second rib34connecting the tie-rod attachment portion26with the lower arm attachment portion28is formed between the tie-rod attachment portion26and the lower arm attachment portion28. The second rib34has a required height and a required width when viewed from the bottom surface of the body portion22.

The second rib34is formed to be wider than the first rib32.

A third rib36is formed between the first rib32and the second rib34so as to bridge the first rib32and the second rib34. The third rib36constitutes a part of a wall portion of the recessed body portion22.

A recess38is formed by casting in a region surrounded by the first rib32, the second rib34, and the third rib36so that these ribs have a required width.

The first rib32, the second rib34, and the third rib36having a required height and a required width form a structure having a triangular shape in a front view, and as a result, the required strength (rigidity) is ensured even in an aluminum knuckle having a strength lower than an iron knuckle.

Reference numeral40denotes a through hole for attaching a wheel speed sensor provided in the side surface portion of the body portion22.

In the present embodiment, the first rib32is formed with a first inclined portion32ainclined such that the height gradually decreases from the damper attachment portion24toward the tie-rod attachment portion26, and a first thin portion32bhaving a low height, which is a bottom portion of the first inclined portion32a, is formed.

The third rib36is formed with a second inclined portion36ainclined such that the height gradually decreases from the second rib34toward the first rib32, and a second thin portion36bserving as a bottom portion of the second inclined portion36a.

Therefore, when viewed from a side surface side of the knuckle20(FIG.2), an inclined surface of the first inclined portion32aand an inclined surface of the second inclined portion36aintersect each other in a substantially V-shape. The first inclined portion32aand the second inclined portion36aare formed such that the first thin portion32band the second thin portion36bsubstantially overlap each other when viewed from the side surface side of the knuckle20.

In the present embodiment, the position of the through hole40for attaching a wheel speed sensor provided in the side surface portion of the body portion22is set so as to be in the vicinity of the first thin portion32band the second thin portion36b.

In this way, the first rib32and the third rib36are secured such that the ribs having a required height are relatively long by shortening the thin portions. As a result, a triangular structure is secured by the first rib32, the second rib34, and the third rib36, and the strength (rigidity) required in a normal state is maintained.

On the other hand, the first thin portion32band the second thin portion36bserve as starting points of bending of the first rib32and the third rib36, respectively. When an external force is applied to the knuckle20from a front direction or an oblique front direction due to an inadvertent external force from the front direction or the oblique front direction, the first thin portion32band the second thin portion36bserve as starting points of bending of the first rib32and the third rib36, respectively, the first rib32and the third rib36are bent, and the knuckle20is bent as a whole between the damper attachment portion24and the tie-rod attachment portion26. Thus, it is possible to reduce a possibility that the tie-rod attachment portion26enters the vehicle interior, and to suppress an influence on the vehicle interior.

By appropriately setting the length of the first inclined portion32a, that is, the position of the first thin portion32b, and the position of the second inclined portion36a, that is, the position of the second thin portion36b, a starting point of bending (fracture) can be controlled.

As described above, in the case where the position of the through hole40for attaching a wheel speed sensor provided in the side surface portion of the body portion22is set so as to be in the vicinity of the first thin portion32band the second thin portion36b, since the strength of the first thin portion32band the second thin portion36bis further reduced, when an inadvertent force is applied from the outside, the knuckle20is easily bent at the portion, and the influence on the vehicle interior can be further suppressed.