JP2012001080A - Steering column mounting bracket - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a mounting bracket composing a shock absorber for a steering mechanism so as to be adjusted in a direction where load-deflection characteristics can be easily adjusted, and in particular, peak loads can be easily raised.SOLUTION: The mounting bracket 1 is a support member which causes a steering column 2 to support a vehicle body member 3. A mounting surface 11 which is fixed to the vehicle body member 3 and a support surface 12 which is mounted on the steering column 2 compose a bent cross section through a main bent edge 14 which extends to be orthogonal to the steering column 2. In this case, the mounting bracket 1 for the steering column 2 has a bead 15 formed which is disposed in such a way as to intersect a main bent edge 14 while extending over the mounting surface 11 and the support surface 12.

Description

  The present invention relates to a mounting bracket for supporting a steering column on a vehicle body side member.

  A steering mechanism (steering mechanism) in a vehicle is composed of a steering column that rotatably stores a steering shaft with a handle attached thereto, and is supported by a vehicle body side member via a support member. Although it is sufficient for the steering mechanism to be able to stably support the steering column on the vehicle body side member, in order to prevent the driver from being injured from the "secondary collision" in which the driver hits the steering wheel in the event of a vehicle collision, An impact absorbing device that absorbs impact energy is incorporated.

  The shock absorber of the steering mechanism is a ripping plate type that absorbs impact energy by tearing a dedicated member (ripping plate), or a bending deformation (plastic deformation) of a support member (mounting bracket) that supports the steering column on the vehicle body side member. There is a bending type that absorbs impact energy using The latter bending type shock absorbing device for a steering mechanism is preferable as a simple configuration that does not require a separate member in the steering mechanism.

  Patent Document 1 discloses an attachment surface (first plate portion) fixed to a vehicle body side member, a support surface (second plate portion) attached to a steering column, and an L-shaped connection surface connecting the attachment surface and the support surface. (Connecting plate part) is connected via a main bent edge (first bent part) and a lower secondary bent edge (second bent part), and separated from the main bent edge and the secondary bent edge. A mounting bracket composed of a plate material in which a subfolded edge (third bent portion) is provided on the connecting plate portion is disclosed (Patent Document 1, Claim 1 and others). In the mounting bracket disclosed in Patent Document 1, bending deformation occurs between the upper and lower sub-bending edges, so that the support surface is moved in parallel to prevent the steering column from being twisted and to absorb good impact energy. This is realized (Patent Document 1 [0005] et al.).

JP 2008-087537 A

  The mounting bracket disclosed in Patent Document 1 adjusts the load displacement characteristics (particularly peak load) by changing the overall shape and plate thickness, as well as opening through holes across each surface or each surface. However, it is difficult to adjust the load displacement characteristics by changing the overall shape or the plate thickness, and there is a problem that it cannot be adjusted as designed. Further, the adjustment of the load displacement characteristics by the through holes can be adjusted only in the direction in which the peak load is lowered by facilitating bending deformation, and cannot be adjusted in the direction in which the peak load is increased (Patent Document 1 [0006], etc.). . Therefore, a mounting bracket that constitutes the shock absorbing device of the steering mechanism has been studied so that the load displacement characteristics can be easily adjusted, and in particular, the peak load can be increased.

  What has been developed as a result of the study is a support member that supports the steering column with respect to the vehicle body side member, and the mounting surface fixed to the vehicle body side member and the support surface attached to the steering column are perpendicular to the steering column. In the mounting bracket which comprises the bending cross section via the main bending edge extended, it is a mounting bracket of the steering column by which the bead which cross | intersects a main bending edge and extends over a mounting surface and a support surface is formed. As will be described later, since the outer shape or cross-sectional shape and depth of the bead are free, the bead only needs to intersect the main folding edge, but if the bead is an outer shape having directionality, the bead is main folded. It is preferable to be orthogonal to the curved edge.

  The mounting bracket that constitutes the shock absorber of the steering mechanism has a support surface that moves integrally with the steering column that moves forward in response to the impact against the mounting surface that is fixed to the vehicle body side member. And absorb impact energy. The mounting bracket of the present invention forms a bead extending across the mounting surface and the support surface by intersecting the main folding edge to increase the rigidity at the main folding edge, and bending required for bending deformation occurring across the main folding edge. By increasing the stress, the load displacement characteristics are improved (the peak load is increased and the energy absorption amount is also increased).

  The outer shape or cross-sectional shape or depth of the bead (hereinafter referred to as the outer shape or the like) is free, and the load displacement characteristics by the mounting bracket are adjusted by adjusting the outer shape and the like. In addition to the specific outer shape of the bead, it also depends on the outer shape of the mounting bracket and the degree of interference with other members attached to the steering mechanism and vehicle body side members. Here, the bead start end (bead start of the bead on the mounting surface) and bead end point (end of the bead on the support surface) are all within the range of the mounting surface and the support surface, and the bead cross section is at the periphery of the mounting surface or the support surface. It is desirable not to appear. More specifically, the bead also intersects a line (fastening line) connecting a mounting portion (screw hole or the like) with respect to the vehicle body side member on the mounting surface, and the bead starting end is positioned between the peripheral edge of the mounting surface and the fastening line. Good.

  The support surface is divided into a lower support surface attached to the steering column and an upper support surface connecting the lower support surface and the main bent edge with a sub-folded edge extending perpendicular to the steering column. In the configuration, the bead may be formed across the mounting surface and the upper support surface so as to intersect the main folding edge. There may be a plurality of minor folding edges. In this case, if the folding direction is changed for each minor folding edge (for example, mountain folding → valley folding → mountain folding, etc.), the lower support surface advances under impact. Since the steering column can be moved in parallel with the steering column and the steering column that moves forward is not twisted, the effect of improving the load displacement characteristics by providing beads on the main folding edge (higher peak load) The effect of increasing the amount of energy absorption is not impaired.

  The mounting bracket of the present invention has the effect of improving the rigidity at the main bent edge by forming a bead that intersects the main bent edge, and in particular has the effect of increasing the peak load. Deformation is difficult to occur, and the function of the mounting bracket as an impact absorbing device is impaired. Therefore, in order to moderately reduce the peak load that has become too high by forming the bead, the bead opens a through hole and reduces the rigidity at the main bent edge. The outer shape and size of the through holes are determined so that the rigidity due to the formation of the beads is lowered and the peak load is within the allowable range of the required design value.

  Moreover, in order to reduce the peak load which became too high by forming a bead like the above-mentioned, the bead may form the dent (driving) which corresponds to the main bending edge which cross | intersects. The dent is a part that facilitates bending deformation of the bead, and has a function of reducing rigidity due to the formation of the bead. As long as the bending deformation of the bead can be promoted in this way, the dent may be formed on either the front surface side or the back surface side of the bead. The cross-sectional shape and depth of the dent are determined so that the rigidity due to the formation of the bead is lowered and the peak load is within the allowable range of the required design value.

  The present invention brings about an effect that the load displacement characteristic of the mounting bracket constituting the shock absorbing device of the steering mechanism can be easily adjusted. This is an effect by the bead formed crossing the main bending edge first. And this invention also brings about the effect which enlarges the adjustment width | variety of the load displacement characteristic of the said mounting bracket. This is because the bead provides an adjustment allowance for increasing the peak load that affects the amount of energy absorption, and an adjustment allowance for reducing the peak load by a through hole or a recess opening in the bead. The effect of easily adjusting the load displacement characteristics and increasing the adjustment range makes it easy to realize the required load displacement characteristics (especially peak load), and has the advantage of maintaining quality even if the number of samples for sampling inspection is reduced. Bring.

  The formation of a bead that intersects the main bent edge increases the rigidity of the mounting bracket at the main bent edge, and even if the thickness of the mounting bracket to which the present invention is applied can be reduced, sufficient and sufficient load displacement characteristics can be secured. This means that a thin plate material is used as compared with the conventional mounting bracket of the same type, thereby reducing the material cost and bringing about a secondary effect of realizing weight reduction. In particular, the weight-reduced mounting bracket has a higher natural vibration value than the conventional mounting bracket of the same type, and brings about a secondary effect of suppressing the vibration of the supporting steering column. As described above, the present invention not only improves the load displacement characteristics of the mounting bracket as the shock absorbing device, but also improves the cost and mechanical properties of the mounting bracket as the structural member.

It is the perspective view which looked at an example of the attachment bracket to which this invention was applied from the front direction. It is a front view of the mounting bracket of this example. It is a side view of the steering column supported by the vehicle body side member by the mounting bracket of this example. It is the perspective view equivalent to FIG. 1 which looked at the attachment bracket (without a through-hole) of another example from the front direction. It is the perspective view equivalent to FIG. 1 which looked at the attachment bracket (bead is equal width) of another example from the front direction. It is the perspective view equivalent to FIG. 1 which looked at the mounting bracket (bead start end appears on the periphery of a mounting surface) of another example from the front direction. It is the perspective view equivalent to FIG. 1 which looked at the mounting bracket (single support surface) of another example from the front direction. It is a side view of the mounting bracket of this example which supported the steering column. FIG. 4 is a side view corresponding to FIG. 3 of the mounting bracket of the present example plastically deformed to absorb impact energy.

  Hereinafter, modes for carrying out the present invention will be described. The present invention is applied to a mounting bracket 1 constituting an impact absorbing device for a steering mechanism, as seen in FIGS. In the mounting bracket 1 of this example, an attachment surface 11 fixed to the vehicle body side member 3 and an upper support surface 12 attached to the steering column 2 are interposed via a main bent edge 14 extending perpendicularly to the steering column 2. A bead 15 extending across the attachment surface 11 and the upper support surface 12 is formed so as to intersect the main bending edge 14. The attachment surface 11 is provided with a pair of left and right bolt notches (attachment portions) 111 and 111 on the periphery parallel to the main bent edge 14. The bead starting end 151 intersects the fastening line connecting the bolt notches 111 and 111 and extends toward the peripheral edge, and is positioned between the peripheral edge of the mounting surface 11 and the fastening line.

  In the mounting bracket 1 of this example, the support surface that is bent and deformed with respect to the mounting surface 11 via the main bent edge 14 is divided into an upper support surface 12 and a lower support surface 13. Specifically, an upper support surface 12 descending obliquely rearward (leftward in FIG. 1) from the mounting surface 11 and a lower support surface 13 orthogonal to the steering column 2 are connected with an intermediate surface 122 interposed therebetween. The bead end 151 is within the range of the upper support surface 12. The lower support surface 13 is opened around a shaft through hole 132 through which a steering shaft (not shown) extending from the steering column 2 passes, and a bolt hole 133 through which a connecting bolt 21 joined to the steering column 2 is inserted into the shaft through hole. A pair is provided diagonally across the hole 132.

  The mounting surface 11 and the upper support surface 12 are valley-folded (concave section with respect to the right side in FIG. 3) via a main bending edge 14 orthogonal to the steering column 2. The bending angle between the mounting surface 11 and the upper support surface 12 in this example is 135 degrees. The upper support surface 12 and the intermediate surface 122 are mountain-folded (a convex cross section with respect to the right side in FIG. 3) via a first sub-bending edge 121 orthogonal to the steering column 2. The bending angle between the upper support surface 12 and the intermediate surface 122 in this example is 75 degrees. The lower support surface 13 and the intermediate surface 122 are folded at a valley (a concave cross section with respect to the right side in FIG. 3) via a second auxiliary folding edge 131 orthogonal to the steering column 2. The bending angle between the lower support surface 13 and the intermediate surface 122 in this example is 90 degrees.

  As shown in FIG. 3, the steering column 2 is connected to a bolt hole 133 provided in the lower support surface 13 of the mounting bracket 1 by a connecting bolt 21, and a vehicle body side member (for example, Deck cross member etc.) 3 is supported. A steering shaft (not shown) extending from the steering column 2 passes through the shaft through hole of the lower support surface 13 and extends forward (rightward in FIG. 3). In addition, the steering column 2 is supported by another part of the vehicle body side member 3 via the auxiliary bracket 22. The auxiliary bracket 22 allows the steering column 2 to be easily separated when an impact is applied to the steering column 2 from behind (a driver hits a handle not shown in the case of a collision accident or the like).

  A feature of the mounting bracket 1 of the present invention is a bead 15 formed so as to intersect the main bent edge 14. The bead 15 of the present example is a convex portion that bulges a square plane in front view, and as described above, intersects with the fastening line connecting the bolt notches 111, 111 toward the periphery of the mounting surface 11. The bead starting end 151 extends from the upper side. Accordingly, the rigidity reduction of the mounting surface 11 due to the provision of the bolt notch 111 is reinforced by the bead starting end 151 of the bead 15. The bead 15 of this example is provided with a through hole 153 in a plane that hangs on the upper support surface 12 and forms a recess (driving) 154 that coincides with the main folding edge 14, so that the main folding edge 14 is excessively raised. Rigidity is lowered and bending deformation is easily caused to absorb impact energy.

  As shown in FIG. 4, the bead 16 of another example is provided with a bead start end 161 and a bead end 162 similar to the bead 15 of the present example, and further forms a recess 164 that coincides with the main bent edge 14, By not providing, the rigidity at the main bent edge 14 is higher than in this example. In addition, as shown in FIG. 5, the bead 17 of another example has no through holes and dents, the bead end 172 is the same as that of this example, the mounting surface 11 is wider than this example, and the notches 111, 111 for bolts are used. By extending the bead start end 171 that intersects with the fastening line that connects to the periphery of the mounting surface 11 while maintaining the same width as the main body of the bead 17, the rigidity at the main bent edge 14 is increased. In this case, as shown in FIG. 6, the bead 18 having the bead starting end 181 reaching the periphery of the mounting surface 11 while the width of the mounting surface 11 and the bead end 182 are the same as the bead 17 is the main bent edge. The rigidity at 14 can also be made slightly lower than when the beads 17 are provided.

  In addition to the above-described examples (see FIGS. 1 to 6), the present invention can be applied to various conventionally known mounting brackets 1 that exhibit an impact absorbing function by plastic deformation. For example, as shown in FIG. 7, the steering column 2 is composed of a single support surface 193 provided with a hinge flange 195 for supporting (tilting) the tilting column 2 so that it can be swung up and down, and a mounting surface 11. In the case of the mounting bracket 1, a bead 19 is provided across the main bent edge 14 that is a boundary between the mounting surface 11 and the support surface 193 by applying the present invention. The bead 19 of this other example has the same width from the bead start end 191 to the bead end 192 and forms a recess 194 that coincides with the main bent edge 14.

Thus, the outer shape or cross-sectional shape and depth of the bead 15 are free, and the presence or absence of through holes or dents is also free. However, from the viewpoint of improving the rigidity at the main bent edge 14, as shown in FIG. 8, the bead 15 has a section modulus of the mounting bracket 1 including the bead 15 at the main bent edge 14 as Z 1, and the lower support surface 13. L1 is the distance from the load point M, which is the intersection of the axis of the steering column 2 to which the steering column 2 is attached, and the lower support surface 13 to the bead 15 at the main bent edge 14, and the mounting bracket 1 of the bead end 152 at the upper support surface 12 The section modulus of Z2 is Z2, the distance from the load point M that is the intersection of the axis of the steering column 2 to which the lower support surface 13 is attached and the lower support surface 13 to the bead end 152 is added to L2 and the load point M If the load to be applied is F,
L1 × F / Z1> L2 × F / Z2
Make a relationship. In other words, as long as the above relationship is followed, the outer shape or cross-sectional shape and depth of the bead 15 are free, and the presence or absence of a through hole or a recess is also free.

  When the mounting bracket 1 formed with the beads 15 according to the above relationship receives a load F from the steering column 2 due to an impact, the upper support surface 12 reduces the bending angle with respect to the mounting surface 11 as seen in FIG. Further, the intermediate surface 122 is bent with respect to the upper support surface 12 and the lower support surface 13 is bent with respect to the intermediate surface 122 so that the bending angle is increased. Absorb impact energy. Here, by bending and deforming the first sub-bending edge 121 and the second sub-bending edge 131 as well, the lower support surface 13 that moves forward in response to an impact becomes like moving parallel to the steering column 2 and moves forward. The steering column will not be twisted.

  The mounting bracket 1 as an impact absorbing device of the steering mechanism absorbs impact energy mainly by bending deformation at the main bent edge 14. In this example, bending deformation at the first sub-folding edge 121 and the second sub-folding edge 131 also contributes to the absorption of impact energy. The bead 15 prevents the bending deformation at the main bending edge 14 and increases the bending stress necessary to cause the bending deformation, thereby increasing the peak load and increasing the energy absorption amount. In the mounting bracket 1 of this example, the main bent edge 14 is bent and deformed so that the upper support surface 12 with respect to the mounting surface 11 has a small bending angle. This is a plastic deformation that generates excess meat in the bead 15, and usually excessively increases the bending stress required to cause the bending deformation. The dent 154 absorbs the excess meat of the bead 15 by its own shape deformation (in this example, it is deep with respect to the plane of the bead 15), and facilitates bending deformation of the bead 15 itself.

1 Mounting bracket
11 Mounting surface
12 Upper support surface
13 Lower support surface
14 Main bending edge
15 Bead 2 Steering column
21 Connecting bolt
22 Auxiliary bracket 3 Car body side member
31 Fixing bolt

Claims (4)

A support member for supporting the steering column with respect to the vehicle body side member, and a main bent edge in which an attachment surface fixed to the vehicle body side member and a support surface attached to the steering column extend perpendicular to the steering column In the mounting bracket that constitutes the bending section through
A mounting bracket for a steering column, characterized in that a bead extending between a mounting surface and a support surface is formed so as to intersect a main bent edge. The support surface is divided into a lower support surface attached to the steering column and an upper support surface connecting the lower support surface and the main bent edge with a sub-folded edge extending perpendicular to the steering column. ,
2. The steering column mounting bracket according to claim 1, wherein the bead is formed across the mounting surface and the upper support surface so as to intersect the main bending edge. The steering column mounting bracket according to claim 1 or 2, wherein the bead has a through hole. The mounting bracket for a steering column according to any one of claims 1 to 3, wherein the bead is formed with a recess corresponding to the intersecting main bent edges.

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