JP6936162B2 - Steering support structure - Google Patents

Description

The present invention relates to a steering support structure provided in a vehicle.

FIG. 4 is an example of the steering support structure.
This steering support structure has an instrument paneling force extending in the width direction of the vehicle, a steering support upper facing the instrument paneling force from above and fixed to the instrument paneling force, and facing the instrument paneling force from below. It also has an instrument panel reinforcement and a steering support lower fixed to the steering support upper. Further, a steering column (not shown) is supported by the steering support upper and the steering support lower, and the steering column supports the steering shaft so as to be rotatable and non-sliding in the axial direction.

The steering support upper has a top plate that constitutes the entire upper surface thereof, and a pair of left and right side plates that extend downward from both left and right sides of the top plate. Further, welded portions having a substantially semicircular side surface are formed on the lower surfaces of the left and right side plates. The left and right welds are in contact with the outer peripheral surface of the instrument panel from above. The entire left and right welds are arc-welded to the outer peripheral surface of the instrument panel force. Further, the upper surface plate is formed with an arcuate cross-sectional portion whose position in the front-rear direction is substantially the same as that of the welded portion and whose side surface shape (cross-sectional shape) is substantially arcuate.

A welded portion having a substantially semicircular side surface is formed on the upper surface of the steering support lower. This weld is in contact with the outer peripheral surface of the instrument panel from below. The entire welded portion is arc-welded to the outer peripheral surface of the instrument panelin force. Further, the front end of the steering support lower is welded to the front end of the steering support upper. Further, the steering column is fastened (fixed) to the rear end of the steering support upper and the steering support lower by bolts and nuts, and the steering column is fastened (fixed) to the front end of the steering support upper by bolts and nuts. Has been done.

Japanese Unexamined Patent Publication No. 2014-210548

When the driver of a vehicle equipped with the steering support structure rotates the steering wheel supported by the steering shaft, so-called rack end contact may occur. When the rack end contact is generated, a large force is applied from the rack shaft to the steering shaft, and this force generates a rotational force around the axis of the steering shaft. Then, this rotational force is transmitted as a torsional force to the front part of the steering support upper via the steering column.

Then, stress is generated in the welded portions provided on the left and right side plates of the steering support upper. Then, the largest stress is generated at the front end of the welded portion. In other words, the stress generated in the weld is concentrated at the front end.

Further, since the cross-sectional arcuate portion has an arcuate shape, the torsional rigidity of the arcuate cross-sectional portion is high, and therefore the arcuate cross-sectional portion is hardly deformed. That is, at this time, the arcuate portion of the cross section hardly absorbs this torsional force.

Therefore, the value of the stress concentrated on the front end of the welded portion of the steering support upper may become extremely large. If an extremely large stress is generated at the front end of the weld, this stress may damage the front end of the weld and its vicinity.

In order to prevent such a situation from occurring, in the steering support structure, the front end portion and the rear end portion of the steering support lower are fixed to the front end portion and the rear end portion of the steering support upper, respectively.

However, in order to fix the front end and the rear end of the steering support lower to the front end and the rear end of the steering support upper, respectively, it is necessary to increase the front-rear dimension of the steering support lower. Therefore, the mass of the steering support lower increases. Further, in order to make the steering support lower into a shape that can be turned to the front end of the steering support upper, it is necessary to manufacture the steering support lower by drawing, so that the manufacturing cost is high. Therefore, the mass and manufacturing cost of the steering support structure become large.

The present invention has been made to address the above-mentioned problems. That is, one of the objects of the present invention is a steering support structure capable of reducing the risk of damage to the steering support upper due to rack end contact or the like without increasing the mass and manufacturing cost of the steering support lower and the steering support structure. Is to provide.

The steering support structure (10) of the present invention
Instrument panel force (20) extending in the vehicle width direction,
It has welded portions (35, 41) that are welded while facing the instrument paneling force from above and in contact with the outer peripheral surface of the instrument paneling force, and rotatably supports the steering shaft (60). A steering support upper (30) that supports the steering column (50) and
The steering support lower (45), which is located below the steering support upper and is fixed to the instrument panel force and the steering support upper,
With
The steering support upper connects the front portion (31) that supports the steering column, the rear portion (36) that is separated rearward from the front portion, and the front portion and the rear portion of the steering shaft. It has a flat plate-shaped connecting portion (43) located on the outer peripheral side, and has.
The welded portion has a front welded portion (35) provided in the front portion and a rear welded portion (41) provided in the rear portion.

For example, when the steering shaft generates a large rotational force due to the rack end contact, this rotational force extends to the front part of the steering support upper via the steering column as a torsional force, and is further caused by this torsional force. Stress is generated in the front weld. The stress generated at the front end and the rear end of the front weld is larger than the stress generated at other parts of the front weld. In other words, stress is not concentrated only on the front end of the front weld.

Further, the steering support upper has a flat plate-shaped connecting portion that connects the front portion and the rear portion and is located on the outer peripheral side of the steering shaft. Since the torsional rigidity of the flat plate-shaped connection portion is low, when the torsional force reaches the flat plate-shaped connecting portion, the flat plate-shaped connecting portion is twisted (deformed). That is, at this time, the flat plate-shaped connecting portion efficiently absorbs the twisting force.

Therefore, there is almost no possibility that the stress generated at the front end and the rear end of the front welded portion becomes extremely large. Therefore, it is not necessary to increase the size of the steering support lower in order to connect the front end and the rear end of the steering support lower to the front end and the rear end of the steering support upper. Therefore, the risk of damage to the steering support upper can be reduced without increasing the mass and manufacturing cost of the steering support lower and the steering support structure.

In the above description, in order to help the understanding of the present invention, the names and / or symbols used in the embodiments are added in parentheses to the configurations of the invention corresponding to the embodiments described later. However, each component of the present invention is not limited to the embodiment defined by the reference numerals. Other objects, other features and accompanying advantages of the invention will be readily understood from the description of embodiments of the invention described with reference to the drawings below.

It is a perspective view seen from the front of the steering support structure which concerns on embodiment of this invention. It is a top view which omitted some members of a steering support structure. It is a side view seen from the right side which omitted some members of a steering support structure. It is the same side view as FIG. 3 of the comparative example.

Hereinafter, the steering support structure 10 according to the embodiment of the present invention and provided in the vehicle will be described with reference to the accompanying drawings.
The steering support structure 10 has an instrument panel force 20, a steering support upper 30, a steering support lower 45, and a steering column 50 as main components.

The instrument panel force 20 is a metal pipe that extends linearly in the width direction (left-right direction) of the vehicle. Both ends of the instrument panel force 20 are fixed to the body shell (not shown). Further, an instrument panel (not shown) is fixed to the instrument panel force 20.

The metal steering support upper 30 includes a front portion 31, a rear portion 36, and a flat plate-shaped connecting portion 43. The steering support upper 30 can be manufactured, for example, by press-molding a metal plate.

The front portion 31 has a substantially flat upper surface plate 32, a pair of side plates 33 extending downward from both side edges of the upper surface plate 32, and extending downward from the front edge portion of the upper surface plate 32, and the left and right end portions thereof are left and right. It has a front plate 34 connected to each of the front ends of the side plate 33. Further, a front welded portion 35 having a substantially arc-shaped side surface is formed on the lower edge portion of the rear end portion of the left and right side plates 33. The radius of curvature of the front welded portion 35 is substantially the same as the radius of curvature of the outer peripheral surface of the instrument panelin force 20.

The rear portion 36 has a base portion 37 constituting the front portion thereof and a steering support lower support portion 38 constituting the rear portion. As shown in FIG. 3, the base portion 37 and the steering support lower support portion 38 are inclined to each other in the side view. The rear portion 36 (base portion 37 and steering support lower support portion 38) has an upper surface plate 39 and a pair of side plates 40 extending downward from both side edges of the upper surface plate 39. Further, a rear welded portion 41 having a substantially arc-shaped side surface is formed on the lower edge portion of the front end portion of the left and right side plates 40. The radius of curvature of the rear welded portion 41 is substantially the same as the radius of curvature of the outer peripheral surface of the instrument panelin force 20.

As shown in FIG. 2, the planar shape of the flat plate-shaped connecting portion 43 is substantially trapezoidal, and the left-right width thereof is narrower than that of the front portion 31 and the rear portion 36. The front end portion of the flat plate-shaped connecting portion 43 is connected to the rear end portion of the front portion 31 (upper surface plate 32), and the rear end portion of the flat plate-shaped connecting portion 43 is the front end portion of the rear portion 36 (upper surface plate 39). Is connected to.

The left and right front welds 35 of the steering support upper 30 are mounted on the front part of the upper part of the outer peripheral surface of the instrument panel force 20, and the left and right rear welds 41 are placed on the upper rear part of the outer peripheral surface of the instrument panel force 20. Has been done. Further, the steering support upper 30 is formed by arc-welding the left and right front welds 35 and the outer peripheral surfaces of the instrument paneling force 20 to each other and arc-welding the left and right rear welds 41 and the outer peripheral surfaces of the instrument paneling force 20 to each other. It is fixed to the instrument panel force 20. Further, the front portion 31 is connected to the vehicle body (dash panel) via a connecting member 25 (see FIG. 1) fixed to the front portion 31.

The metal steering support lower 45 includes a top plate 46 and a pair of side plates 47 extending downward from the left and right side edges of the top plate 46. Welded portions 48 having a substantially arc-shaped side surface are formed at the front end portions of the upper surface plate 46 and the front end portions of the left and right side plates 47. The radius of curvature of the welded portion 48 is substantially the same as the radius of curvature of the outer peripheral surface of the instrument panelin force 20. The steering support lower 45 can be manufactured, for example, by press-molding a metal plate.

The rear portion of the steering support lower 45 is in contact with the lower surface of the steering support lower support portion 38 from below, and the steering support lower 45 and the steering support lower support portion 38 are fixed to each other by bolts and nuts (both not shown). Has been done. Further, the welded portion 48 of the steering support lower 45 is in contact with the rear portion of the lower portion of the outer peripheral surface of the instrument panel force 20. Further, the steering support lower 45 is fixed to the instrument panel force 20 by arc welding the welded portion 48 and the outer peripheral surface of the instrument panel force 20 to each other.

The steering column 50 shown in FIG. 1 is fixed to the steering support upper 30 and the steering support lower 45. That is, the front portion of the steering column 50 is fixed to the fastening portion 33a formed at the front end portions of the left and right side plates 33 shown in FIGS. 1 and 3 by using bolts and nuts (not shown). Further, the fastening portions 38a formed on the left and right sides of the steering support lower support portion 38 and the fastening portions 45a formed on the left and right two locations of the steering support lower 45 shown in FIG. It is fixed using a nut (not shown). Further, the steering column 50 supports the steering shaft 60 (see the virtual line in FIG. 3) so that it can rotate around its axis and cannot move relative to the axis. As is well known, a steering hole (not shown) is fixed to the rear end of the steering shaft 60. Further, the front end portion of the steering shaft 60 is connected to a rack shaft (both not shown) extending in the vehicle width direction via a universal joint and a pinion shaft. The left and right ends of the rack axle are connected to the left and right front wheels via a tie bar or the like. When the driver of the vehicle rotates the steering wheel, this rotational force is transmitted to the rack shaft via the steering shaft 60, the universal joint, and the pinion shaft, and the rack shaft slides in the vehicle width direction. Then, the steering angles of the left and right front wheels change.

Subsequently, the operation of the steering support structure 10 will be described.
When the driver of the vehicle rotates the steering wheel, so-called rack end contact may occur. When the rack end contact is generated, a large force is applied from the rack shaft to the steering shaft 60 via the pinion shaft and the universal joint, and this force causes the steering shaft 60 to generate a rotational force around its own axis. Then, this rotational force is transmitted from the steering column 50 to the steering support upper 30 via the left and right fastening portions 33a as a twisting force for twisting the steering support upper 30 around the steering shaft 60.

Then, due to this torsional force, for example, as shown in FIG. 3, a downward force F is applied to the fastening portion 33a of the right side plate 33 and an upward force F is applied to the fastening portion 33a of the left side plate 33 (not shown). Omitted). That is, a force in the opposite direction is applied to the left and right fastening portions 33a. By the way, the left and right side plates 33 can be regarded as cantilever beams having the front welded portion 35 as a fixed end fixed to the instrument paneling force 20 and the end portion on the fastening portion 33a side as a free end. Therefore, a large stress is generated at the front ends of the left and right front welded portions 35 due to the above-mentioned force (F) applied to the left and right fastening portions 33a. Further, the rear ends of the left and right front welds 35 that are separated forward from the rear weld 41 (discontinuous with the rear weld 41) are compared with the case where the front weld 35 and the rear weld 41 are continuous. Is easily deformed. Therefore, a large stress is also generated at the rear ends of the left and right front welded portions 35. That is, the stress generated at the front end and the rear end of the left and right front welded portions 35 is larger than the stress generated at other portions of the front welded portion 35. In other words, the stress generated in the front weld 35 is not concentrated only on the front end. That is, most of the stress generated in the front welded portion 35 is dispersed in the front end and the rear end of the front welded portion 35.

At this time, stress caused by the above-mentioned force (F) generated in the fastening portions 33a of the left and right side plates 33 is also generated in the left and right rear welded portions 41, but the magnitude thereof is larger than the stress generated in the front welded portion 35. Is also small.

Further, since the flat plate-shaped connecting portion 43 of the steering support upper 30 has a flat plate shape, the torsional rigidity is low. In other words, the torsional rigidity of the flat plate-shaped connecting portion 43 of the present embodiment is lower than that of the case where the cross-sectional shape of the portion corresponding to the flat plate-shaped connecting portion 43 is an arc shape as in the comparative example. Moreover, since the vehicle width dimension of the flat plate-shaped connecting portion 43 is smaller than that of the front portion 31 and the rear portion 36, the vehicle width dimension of the flat plate-shaped connecting portion 43 is the same as that of the front portion 31 or the rear portion 36. The torsional rigidity of the flat plate-shaped connecting portion 43 is smaller. Therefore, when the twisting force reaches the flat plate-shaped connecting portion 43, the flat plate-shaped connecting portion 43 is twisted (deformed). That is, at this time, the flat plate-shaped connecting portion 43 efficiently absorbs the twisting force. If the torsional force at this time is extremely large, the flat plate-shaped connecting portion 43 is plastically deformed, and if the torsional force is not so large, the flat plate-shaped connecting portion 43 is twisted within the elastic limit.

Therefore, there is almost no possibility that the stress generated at the front end and the rear end of the left and right front welded portions 35 becomes extremely large. Therefore, it is not necessary to increase the size of the steering support lower 45 in the front-rear direction in order to connect the front end portion of the steering support lower 45 to the steering support upper 30 as in the comparative example. Therefore, the mass of the steering support lower 45 does not increase. Further, since it is not necessary to perform drawing processing when the steering support lower 45 is manufactured by press molding, it is possible to reduce the manufacturing cost of the steering support lower 45. Therefore, the risk of damage to the steering support upper 30 can be reduced without increasing the mass and manufacturing cost of the steering support structure 10 and the steering support lower 45.

Although the present invention has been described above based on the above-described embodiment, the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the object of the present invention.

For example, the front weld 35 and / or the rear weld 41 may be welded to the instrument panel force 20 in a manner different from arc welding. Similarly, the welded portion 48 may be welded to the instrument panel force 20 in a manner different from arc welding.

10 ... Steering support structure, 20 ... Instrument panel force, 30 ... Steering support upper, 31 ... Front part, 33 ... Side plate, 35 ... Front welded part, 36 ... Rear Part, 43 ... Flat plate connection part, 45 ... Steering support lower, 48 ... Welded part, 50 ... Steering column, 60 ... Steering shaft.

Claims (1)

Instrument panel force extending in the width direction of the vehicle,
A steering support upper that has a welded portion that faces the instrument paneling force from above and is welded while contacting the outer peripheral surface of the instrument paneling force, and supports a steering column that rotatably supports the steering shaft. When,
A steering support lower that is fixed to the instrument panel force and the steering support upper while being located below the steering support upper.
With
The steering support upper connects the front portion that supports the steering column, the rear portion that is separated rearward from the front portion, and the front portion and the rear portion, and is a flat plate that is located on the outer peripheral side of the steering shaft. Has a shape connection and
The welded portion has a front welded portion provided on the front portion and a rear welded portion provided on the rear portion.
Steering support structure.

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