JP3753301B2 - Steering shaft column structure - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a column structure that rotatably supports a steering shaft of an automobile.
[0002]
[Prior art]
For example, as a column structure of a steering shaft employed in an automobile, as shown in FIG. 4, a steering shaft 41 is rotatably supported by a steel tube column tube 40, and the column tube 40 is connected to a coupling member 43 of a cross member 42. Generally, a structure attached to and fixed to is used.
[0003]
When such a column structure is employed, conventionally, brackets 44 and 45 are welded to both ends of the column tube 40 from the viewpoint of increasing the support rigidity of the steering shaft 41, and the brackets 44 and 45 are connected to the coupling member 43. In some cases, the bolts may be fixed by bolting (for example, see JP-A-10-59213).
[0004]
In addition, from the viewpoint of suppressing the impact on the occupant by absorbing the impact force acting on the steering shaft 41 in the event of a vehicle collision, the column tube 40 is divided into two parts, an outer cylinder 40a and an inner cylinder 40b. There is a case in which an impact absorbing mechanism 46 is provided between them, or an impact absorbing mechanism (not shown) is provided between the column tube 40 and the coupling member 43 (for example, JP-A-10-59213 and JP-A-11). -29050).
[0005]
[Problems to be solved by the invention]
However, since the conventional column structure is a structure in which separate brackets 44 and 45 are welded to the column tube 40, there is a problem that the cost increases as the welding work and the number of parts increase.
[0006]
In addition, when a structure in which a separate impact force absorbing mechanism is provided in the column tube to absorb collision energy as in the conventional case, the column structure becomes complicated and the number of parts increases, and the cost increases as described above. There is a problem of doing.
[0007]
The present invention has been made in view of the above-described conventional situation, and an object of the present invention is to provide a steering shaft column structure that can secure the steering shaft support rigidity and the energy absorption capability at the time of collision without increasing the number of parts. Yes.
[0008]
[Means for Solving the Problems]
The present invention is a column structure of a steering shaft so as to rotatably support the steering shaft by a column which is mounted fixed to the vehicle body, and the column body and the column, Ru extends so as to cover the occupant side of the steering shaft, The column main body has upper and lower bracket portions formed on the upper and lower portions in the longitudinal direction and fixed to the vehicle body . The column main body, upper and lower bracket portions are formed of a single member. The column body has an opening extending in the longitudinal direction along the steering shaft and opening toward the steering shaft, and has a circular cross-sectional shape. A detaching machine that detaches from the vehicle body when an axial impact force acts on the steering shaft on the upper bracket portion. When the impact force is applied, the edge of the opening of the column body is positioned closer to the occupant side than the axis of the steering shaft so that the column body deforms downward between the upper and lower brackets. It is characterized by that.
[0009]
Here, as the above-mentioned detachment mechanism, when the upper bracket portion is fixed to the vehicle body by bolting, for example, the upper bracket portion is notched so as to open the bolt hole, or a notch groove is formed in the fastening bolt. It can be realized by forming.
[0011]
[Effects of the invention]
According to the column structure of the present invention, the column is constituted by the arc-shaped column main body that covers the passenger side of the steering shaft, and the bracket portions formed at both ends of the column main body. And the bracket portion can be formed at the same time, so that it is possible to eliminate the need for welding work in the case of welding a separate conventional bracket, reduce the number of parts, and reduce the cost. Further, since the column main body has an arcuate cross section and both end bracket portions of the column main body are fixedly attached to the vehicle body, the rigidity in the axial direction of the steering shaft can be ensured.
[0012]
In the present invention, the column main body extends along the steering shaft, and the release mechanism is provided on the upper bracket portion. Therefore, when an impact force in the axial direction acts on the steering shaft at the time of a collision, the upper bracket portion is Since the lower bracket portion is fixed to the vehicle body while being detached from the vehicle body, the column main body is deformed in the axial direction, thereby absorbing the collision energy. As a result, the column itself functions as an impact absorbing mechanism, and the structure can be simplified and the number of parts can be reduced as compared with the case where a conventional separate impact absorbing mechanism is provided. In this respect, the cost can be reduced.
[0013]
Furthermore, according to the present invention, since the column main body has an arc shape in cross section, for example, when the occupant's foot or knee collides, the column main body is deformed and absorbs the impact force. It is possible to obtain an energy absorption function that was difficult in some cases.
[0014]
In the present invention, since the edge of the opening of the column main body is formed so as to be positioned closer to the occupant side than the axis of the steering shaft, the deformation due to the collision force can be easily and reliably performed while maintaining the support rigidity of the steering shaft. , The energy absorption function can be further enhanced.
[0015]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.
[0016]
1 to 3 are views for explaining a column structure of a steering shaft according to an embodiment of the present invention. FIG. 1 is a partially sectional side view showing the periphery of the column of the steering shaft, and FIG. 2 is a perspective view of the column. FIGS. 3A and 3B are cross-sectional views (a cross-sectional view taken along the line III-III in FIG. 1) in a column mounting state.
[0017]
In the figure, reference numeral 1 denotes an automobile steering device, which connects and fixes a steering wheel 3 to an upper end 2a of a steering shaft 2 and connects an intermediate shaft 5 to a lower end 2b via a universal joint 4, A steering gear (not shown) is connected to the intermediate shaft 5.
[0018]
The steering shaft 2 is supported by a cross member (vehicle body) 7 via a column 6 described later. The cross member 7 is made of a steel pipe, and both ends thereof are coupled to left and right front pillars (not shown), and the intermediate portion is coupled to a cowl panel (not shown) in front of the vehicle via a bracket. ing.
[0019]
A connecting member 8 having a box shape with a closed cross section is joined to the cross member 7 by welding. The coupling member 8 is formed by welding and joining the upper member 8a and the lower member 8b in the middle, and the column 6 is attached to the lower surface of the lower member 8b.
[0020]
The column 6 is made of sheet metal formed by press molding, extends over substantially the entire length of the steering shaft 2, and has a column main body 10 having an arcuate cross section that covers the lower surface occupant side of the steering shaft 2. The left and right upper bracket portions 11 and 11 extending outward in the vehicle width direction at the upper end portion of the column body 10 and the left and right lower bracket portions 12 and 12 extending outward in the vehicle width direction at the lower end portion; Are integrally formed.
[0021]
The column main body 10 is formed so that the edge 10a of the opening is located below (the occupant side) from the axis A of the steering shaft 2, and specifically, about 1/3 of the entire circumference of the column main body. Is set to
[0022]
A cylindrical portion 13 is integrally formed on the upper side of the upper bracket 11 of the column body 10. The cylindrical portion 13 is formed by forming a cylindrical body at the time of the press molding and joining the butted portion 13a of the cylindrical body by welding. A bearing 14 is inserted and fixed in the cylindrical portion 13, and the steering shaft 2 is rotatably supported by the bearing 14.
[0023]
Each lower bracket portion 12 is formed with a bolt hole 12a, and the lower bracket portion 12 is fastened and fixed to the lower member 8b of the coupling member 8 by bolts 16 and 16 inserted into the bolt hole 12a. ing.
[0024]
Each upper bracket portion 11 is formed with a slit 11a constituting a detaching mechanism. The slit 11a is formed by cutting out the rear edge of the bracket portion 11 so as to open. The upper bracket portion 11 is fastened and fixed to the lower member 8b by bolts 17 and 17 inserted in the slit 11a. In this manner, the upper bracket portion 11 is configured to be detached from the coupling member 8 when an impact force exceeding the fastening force of the bolt 17 is applied to the steering shaft 2.
[0025]
Next, the effect of this embodiment is demonstrated.
[0026]
According to the present embodiment, the upper bracket portion 11 and the lower bracket portion 12 that are bolted and fixed to the coupling member 8 are integrally formed on the arc-shaped column body 10 that extends so as to cover the passenger side of the steering shaft 2. Since the cylindrical portion 13 that supports the steering shaft 2 is integrally formed, the column main body 10, the bracket portions 11, 12 and the cylindrical portion 13 can be formed simultaneously by press molding, and a conventional separate bracket is welded. In this case, the welding work can be eliminated, and the number of parts can be reduced, thereby reducing the cost.
[0027]
Further, since the column main body 10 has an arcuate cross section and the bracket portions 11 and 12 of the column main body 10 are bolted and fixed to the coupling member 8, the support rigidity in the axial direction of the steering shaft 2 can be ensured.
[0028]
In the present embodiment, the column body 10 is extended along the steering shaft 2 and the upper bracket portion 11 is detached by an impact force equal to or greater than a predetermined value. When the force is applied, the upper bracket portion 11 is detached from the coupling member 8, while the lower bracket portion 12 is fastened and fixed to the coupling member 8, so that the column main body 10 is deformed downward, and accordingly The collision energy will be absorbed. As a result, the column 6 itself functions as an impact absorbing mechanism, and the structure can be simplified and the number of parts can be reduced as compared with the case where a conventional separate impact absorbing mechanism is provided. In this respect, the cost can be reduced.
[0029]
Furthermore, in the present embodiment, the column body 10 is formed such that the edge 10a of the opening is located below the axis A of the steering shaft 2, so that deformation due to impact force can be easily and reliably performed. The energy absorption function can be further enhanced while maintaining the support rigidity of the steering shaft 2.
[0030]
Further, since the column main body 10 has an arcuate cross section, when the occupant's foot or knee collides for some reason, the column main body 10 is deformed and absorbs the impact force, so that a conventional steel tube column tube is used. In this way, it is possible to obtain an energy absorption function that was difficult to achieve, and to avoid the influence on the passenger.
[0031]
In the above embodiment, the case where energy is absorbed by deforming the entire column main body 10 downward in the event of a collision has been described. However, the present invention can be applied to the column main body 10 as shown in FIG. It is also possible to cut and form the thin portion 10b with a predetermined interval in the longitudinal direction, thereby compressing and deforming the column main body 10 in the axial direction, and in this case, the amount of downward deformation can be reduced.
[Brief description of the drawings]
FIG. 1 is a partial cross-sectional side view for explaining a column structure of a steering shaft according to an embodiment of the present invention.
FIG. 2 is a perspective view of a column according to the embodiment.
FIG. 3 is a cross-sectional view (a cross-sectional view taken along line III-III in FIG. 1) in a state where the column is mounted and fixed.
FIG. 4 is a diagram showing a conventional general column structure.
[Explanation of symbols]
2 Steering shaft 6 Column 7 Cross member (vehicle body)
10 Column body 10a Opening edge 11 Upper bracket 11a Slit (detaching mechanism)
12 Lower bracket part A Steering shaft axis

Claims (1)

In the column structure of the steering shaft so as to rotatably support the steering shaft by a column which is mounted fixed to the vehicle body, the column, the column body which Ru extending so as to cover the occupant side of the steering shaft, of the column body The upper and lower bracket portions are formed on the upper and lower portions in the longitudinal direction and are fixed to the vehicle body . The column main body and the upper and lower bracket portions are formed simultaneously from one member. The column body has an opening extending in the longitudinal direction along the steering shaft and opening toward the steering shaft, and has a circular cross-sectional shape. Providing a detaching mechanism for detaching from the vehicle body when an axial impact force acts on the steering shaft; The edge of the opening of the column body is positioned closer to the occupant side than the axis of the steering shaft so that the column body deforms downward between the upper and lower brackets when the impact force is applied. Characteristic steering shaft column structure.

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