JP2008230267A - Shock absorbing steering column device - Google Patents

Abstract

An abrupt change in shock absorption load is reduced even when an impact load is applied to a driver during a secondary collision.
A pair of fixing members (30h) are arranged apart from each other in the vehicle width direction, and a moving member (32d) is arranged between the pair of fixing members. The energy absorbing member 48 disposed on the pair of fixing members and the moving member includes a central curved portion 48a spanning a curved surface facing the front in the vehicle front-rear direction of the moving member, and a rear of the fixing member in the vehicle front-rear direction. A pair of end curved portions 48b that are stretched over the curved surface facing each other, and a knot 48d that extends from the pair of end curved portions toward the front in the vehicle front-rear direction and loosens the knot in the middle. And a pair of straight portions 48c.
[Selection] Figure 4

Description

  The present invention relates to an impact absorption type steering column device that relieves an impact force applied to a driver during a secondary collision.

  In the event of a collision accident, a secondary collision in which the driver's body collides with the steering wheel occurs following a primary collision in which the automobile collides with another automobile or the like. A driver protection device called an impact-absorbing steering column device is used to alleviate the impact on the driver's body during this secondary collision and prevent serious damage to the driver's body. However, various types have been conventionally considered.

  Various members that absorb impact load in the event of a secondary collision are also known. Of these, the energy absorbing member is plastically deformed at the same time as the steering column strokes forward in the vehicle front-rear direction during a secondary collision. Has been generally used as a member that can obtain a shock absorbing steering device that is relatively simple, small and inexpensive (see, for example, Patent Document 1).

The device of Patent Document 1 includes a moving member that is fixed to a steering column that strokes forward in the vehicle longitudinal direction due to the impact of a collision accident, and a vehicle longitudinal direction that is fixed to a vehicle body side member and receives an impact of a collision accident. A cylindrical fixing member that does not displace and an energy absorbing member formed by bending a metal wire. The energy absorbing member includes a base portion and a folded portion integrated with the base portion, the base portion is stretched over the locking portion of the moving member, and the folded portion is stretched over the outer periphery of the fixed member. When the steering column strokes forward in the longitudinal direction of the vehicle in the event of a collision, the folding deformation part is handled on the outer periphery of the fixed member and plastically deforms to generate an impact absorbing load and absorb the impact energy. It has become.
Japanese Patent No. 3389767

By the way, when the steering column strokes to the stroke limit position (when the steering column bottoms out), there is a possibility that the shock absorbing load suddenly increases. Therefore, it is desirable that the shock absorbing load gradually increases immediately before the steering column reaches the bottom, and the shock absorbing load is equal to or less than a predetermined value at the bottom.
However, since the energy absorbing member of the device of Patent Document 1 does not have a structure in which the absorbing capacity of the impact load can be changed according to the change in the stroke of the steering column, the impact absorbing load may increase rapidly. That is, since the apparatus of Patent Document 1 absorbs only a constant impact load from the initial stroke position of the steering column to the bottom, as in the shock absorption characteristic shown in FIG. May rise rapidly.

  Therefore, the present invention has been made paying attention to the unsolved problems of the above-described conventional example, and even if an impact load is applied to the driver at the time of a secondary collision, it is possible to reduce a sudden change in the shock absorption load. An object of the present invention is to provide a shock absorbing steering column device.

  In order to achieve the above object, an impact absorption type steering column apparatus according to a first aspect of the present invention includes a steering column that rotatably supports a steering shaft on an inner side and strokes forward in the vehicle front-rear direction due to the impact of a collision accident. A fixed member that is fixed to the vehicle body side member and does not displace in the vehicle front-rear direction even when an impact of a collision accident is input, a moving member fixed to the steering column, and the fixed member and the moving member engaged And an energy absorbing member that absorbs an impact load at the time of a secondary collision by plastic deformation accompanying a stroke of the steering column, wherein one of the moving member and the fixed member These members are arranged in a pair spaced apart in the vehicle width direction, and the other member of the moving member and the fixed member is 1st plasticity which is arrange | positioned between one pair of said members, and the said energy absorption member was bent and formed with the predetermined curvature so that the curved surface which faces the front or back of the vehicle front-back direction of said other member may be followed. A pair of deformed portions and a pair of one member that is bent at a predetermined curvature so as to extend along the vehicle longitudinal direction of the pair of one member from the first plastic deformable portion and toward the rear or front of the vehicle in the vehicle front-rear direction. The second plastic deformation portion and the pair of second plastic deformation portions extend forward or rearward in the vehicle front-rear direction, and the front or rear end in the vehicle front-rear direction is fixed to the vehicle body side member. In addition to a metal wire having a pair of third plastic deformation portions, a deformation start portion is provided that extends and plastically deforms the entire energy absorbing member from the latter half of the stroke of the steering column.

  According to a second aspect of the present invention, in the shock absorbing steering column device according to the first aspect, the deformation start portion is formed in the middle of the pair of third plastic deformation portions, and in the first half of the stroke of the steering column, It has a loosely tied shape and is a knot that becomes a tight knot in the latter half of the stroke of the steering column.

  According to the shock absorbing type steering column device of the present invention, the deformation start portion extends the entire energy absorbing member and plastically deforms and absorbs an impact load in the latter half of the stroke of the steering column. The shock absorbing load can be gradually increased until the bottom reaches the bottom of the steering column, and the shock absorbing load can be set to a predetermined value or less.

Hereinafter, the best mode for carrying out the present invention (hereinafter referred to as an embodiment) will be described in detail with reference to the drawings.
FIG. 1 is a diagram schematically showing an embodiment of a vehicle according to the present invention.
In the shock absorbing steering column device indicated by reference numeral 12, a steering shaft 11 having a steering wheel 13 mounted at the rear end in the vehicle front-rear direction is rotatably supported. An intermediate shaft 15 that can be expanded and contracted is connected to the front end of the steering shaft 11 in the vehicle longitudinal direction via a universal joint 14.

  A rack and pinion type steering gear 17 is connected to the lower end of the intermediate shaft 15 via a universal joint 16, and a steered wheel 19 is connected to the steering gear 17 via a tie rod 18 and the like. The steered wheel 19 can be steered by steering. Note that peripheral components P such as a combination switch and a column cover are disposed behind the shock absorbing steering column device 12 in the longitudinal direction of the vehicle.

(First embodiment)
2 to 4 show the shock absorption type steering column device 12 according to the first embodiment of the present invention. FIG. 2 is a view showing the shock absorbing steering column device 12 of the present embodiment from the vehicle width direction. FIG. 3 is a view taken along line AA in FIG. 4 is a view taken in the direction of arrows BB in FIG.

  The shock absorbing steering column device 12 of the present embodiment is fixed to an inner column 20 that extends in the vehicle front-rear direction and a vehicle body side member 22, and a front end portion of the inner column 20 in the vehicle body front-rear direction is connected to a pivot pin 24. Are fixed to the vehicle body side member 22, the column connection bracket 26 connected via the outer column 28, the outer column 28 slidably fitted in the axial direction on the rear side of the inner column 20 in the longitudinal direction of the vehicle body. A support bracket 30, a moving bracket 32 supported by the support bracket 30 so as to surround the upper and side portions of the outer column 28, and movable in the vehicle front-rear direction, and bulges below the cylindrical outer column 28. The column side through hole 36 formed in the distance bracket 34 formed in this manner, and the side plate 3 of the moving bracket 32 that contacts the distance bracket 34. The bracket side through hole 40 formed in a, the tilt rod 42 inserted through the column side through hole 36 and the bracket side through hole 40, and the movable bracket 32 via the tilt rod 42 by the swinging operation of the operation lever 44. A lock mechanism 46 that couples to or releases from the outer column 28 and an energy absorbing member 48 that is mounted between the support bracket 30 and the moving bracket 32 are provided. A steering shaft 11 on which the above-described steering wheel 13 is mounted is rotatably supported on the outer column 28 on the rear side of the outer column 28 in the longitudinal direction of the vehicle body.

The column side through hole 36 is formed in a long hole shape such that the long axis of the distance bracket 34 extends in the vehicle front-rear direction.
The bracket side through hole 40 is formed in a long hole shape on the side plate 32a of the moving bracket 32 that contacts the distance bracket 34 so that the long axis extends in the vehicle vertical direction.
Next, specific configurations of the moving bracket 32, the support bracket 30, and the energy absorbing member 48 will be described in detail with reference to FIGS.

  As shown in FIG. 3, the moving bracket 32 is formed integrally with the upper plate 32 b from both edges in the width direction of the upper plate 32 b so as to have a U-shaped cross section, and extends in parallel with each other. Side plate 32a. A pair of guide rails 32c are formed on both sides of the upper plate 32b so as to be engaged with a pair of guide grooves 30c (to be described later) of the support bracket 30 so that the entire moving bracket 32 is movable in the vehicle longitudinal direction. Match.

As shown in FIG. 4, a cylindrical first protrusion is formed on the upper surface of the upper plate 32 b disposed above the outer column 28 in the vehicle vertical direction by the engagement of the support bracket 30 and the pair of guide rails 32 c. A portion 32d is formed to protrude.
As shown in FIGS. 3 and 4, the support bracket 30 is integrally formed with a bracket body 30 a having a rectangular appearance and the bracket body 30 a, and is fixed by a fixing bolt 50 via a connection linear portion 26 a of the column connection bracket 26. A connecting straight portion 30b connected to the vehicle body side member 22 and a pair of guide grooves 30c provided extending in the vehicle front-rear direction so that the pair of guide rails 32c of the moving bracket 32 described above are fitted thereinto. I have.

  The bracket main body 30a fixed to the vehicle body side member 22 is formed with an opening hole that opens in communication with the vehicle in the vertical direction. This opening hole has a large vehicle width direction length on the front side in the vehicle front-rear direction. A first opening hole 30d that opens in a region, and a second opening hole 30e that is provided continuously to the first opening hole 30d and opens in a region that is smaller in the vehicle width direction than the first opening hole 30d. . Further, a step surface 30g lower than the contact surface 30f that contacts the vehicle body side member 22 is formed around the second opening hole 30e, and the second opening hole 30e on the step surface 30g is sandwiched therebetween. Thus, a pair of cylindrical second convex portions 30h are formed at positions spaced substantially equidistant from one and the other in the vehicle width direction.

And the 1st convex part 32d formed in the upper board 32b of the movable bracket 32 enters the 2nd opening hole 30e of the bracket main body 30a from below, and it is located above the step surface 30g in the vehicle up-down direction. It protrudes.
The energy absorbing member 48 is a steel wire material having excellent corrosion resistance with an increased content of chromium and nickel, such as a piano wire (for example, SWRS82A) and a stainless wire (for example, SUS301). The energy absorbing member 48 has a perfect circular cross section and is formed of a steel wire having a uniform thickness.

As shown in FIG. 4, the energy absorbing member 48 includes a central curved portion 48a, a pair of end curved portions 48b integrally formed at both ends of the central curved portion 48a, and the pair of end curved portions. The member includes a pair of straight portions 48c extending in a direction away from the portion 48b and a knot 48d formed on the free end side of the pair of straight portions 48c.
Then, the central curved portion 48a of the energy absorbing member 48 is stretched over a curved surface facing forward in the vehicle front-rear direction of the first convex portion 32d of the moving bracket 32 protruding upward from the second opening hole 30e of the support bracket 30. The pair of curved end portions 48b are stretched over the curved surfaces of the pair of second convex portions 30h of the support bracket 30 facing the rear in the vehicle front-rear direction, and the pair of straight portions 48c extend forward in the vehicle front-rear direction. An end portion 48e that protrudes from a knot 48d that is located forward of the pair of linear portions 48c in the vehicle front-rear direction is fixed to the bracket body 30a via an end fixing member 49. .

Here, the knot 48d positioned forward in the vehicle front-rear direction with respect to the pair of straight portions 48c has a knot shape so that the substantially entire area of the straight portion 48c does not become tightly tied until the second convex portion 30h is moved. It is a stop knot formed by loosening.
The outer column 28 of the present embodiment corresponds to the steering column of the present invention, the pair of second convex portions 30h corresponds to the fixing member of the present invention, and the first convex portion 32d corresponds to the moving member of the present invention. The central curved portion 48a corresponds to the first plastic deformable portion of the present invention, the pair of end curved portions 48b corresponds to the second plastic deformable portion of the present invention, and the pair of linear portions 48c correspond to the third plastic deformable portion of the present invention. The knot 48d corresponds to the deformation start portion of the present invention.

Next, the operation of the shock absorbing steering column device 12 of the present embodiment will be described with reference to FIGS.
The shock absorption type steering column device 12 of the present embodiment acts as follows in the event of a collision to alleviate the impact applied to the driver's body that hits the steering wheel 13. At the time of the secondary collision, the moving bracket 32 is displaced forward in the vehicle longitudinal direction together with the outer column 28. On the other hand, the support bracket 30 fixed to the vehicle body side member 22 is not displaced in the vehicle front-rear direction and remains in the position as it is.

  At this time, as shown in FIG. 5, from the initial stroke to the middle stroke in which the first convex portion 32d of the moving bracket 32 moves forward in the vehicle longitudinal direction, the central curved portion 48a of the energy absorbing member 48 is the first convex portion. It is handled by 32d and undergoes plastic deformation. Further, since the central curved portion 48a is plastically deformed while being pulled forward in the vehicle longitudinal direction, the pair of end curved portions 48b are also handled by the pair of second convex portions 30h and plastically deformed ( The range from the initial position in FIG. 7 to the stroke S1).

  In the second half of the stroke in which the first convex portion 32d further moves to the front bottom position in the vehicle front-rear direction, first, the pair of linear portions 48c move toward the pair of second convex portions 30h, It is handled by the second convex portion 30h and undergoes plastic deformation. Further, the knot 48d formed by loosening the knot shape is plastically deformed while the knot shape is gradually becoming harder due to the movement of the pair of linear portions 48c toward the pair of second convex portions 30h ( Range from stroke S1 to stroke S2 in FIG. 7).

Further, in the latter half of the stroke near the bottoming position, as shown in FIG. 6, the knot 48d becomes a tight knot, and the end 48e is fixed to the bracket body 30a as the first protrusion 32d moves forward in the vehicle front-rear direction. The entire energy absorbing member 48 is stretched and plastically deformed (range from the stroke S2 to the bottoming position in FIG. 7).
Thus, in the latter half of the stroke of the outer column 28 (first convex portion 32d), the pair of straight portions 48c are first handled by the pair of second convex portions 30h and are plastically deformed to loosen the knot shape. Since the knot shape of the knot 48d formed in this manner is gradually hardened and plastically deformed, the shock absorbing load gradually increases. Further, in the second half of the stroke near the bottoming position, the knot 48d becomes a tight knot, so that the entire energy absorbing member 48 is stretched and plastically deformed, so that the shock absorbing load gradually increases.

  That is, in this embodiment, in the second half of the stroke of the outer column 28, the knot shape of the knot 48d is gradually hardened and plastically deformed, and the energy absorbing member 48 as a whole is stretched and plastically deformed, thereby increasing the ability to absorb the impact load. Therefore, as is apparent from the shock load absorption characteristics of FIG. 7, the shock absorption load gradually increases until just before the outer column 28 bottoms out, and when the outer column 28 bottoms out, it is less than a predetermined value. The impact load is absorbed.

Therefore, the shock absorbing load is gradually increased until immediately before the steering column (outer column 28) bottoms, and the shock absorbing load below a predetermined value can be obtained at the bottom.
In addition, the energy absorbing member 48 of the present embodiment is formed by bending a metal wire, and is a member in which a knot 48d having a loose knot is formed in the middle of a pair of straight portions 48c, so that it is complicated to process. A mold or the like is not required, and the manufacturing cost can be reduced.

(Second Embodiment)
Here, what is shown in FIG. 8 is a diagram showing an impact absorption type steering column apparatus using an energy absorbing member having a shape different from that of the energy absorbing member used in the first embodiment.

In the energy absorbing member 48 of the present embodiment, a knot 48f on the free end side of the pair of linear portions 48c is formed by an eight-shaped knot.
The eight-knot knot 48f is also formed with a loose knot so that it does not become a tight knot until substantially the entire area of the straight part 48c moves toward the second convex part 30h.
Note that the knot 48d of the present embodiment corresponds to a deformation start portion of the present invention.

  In the second half of the stroke in which the first convex portion 32d moves to the front bottom position in the vehicle front-rear direction at the time of a secondary collision, the pair of linear portions 48c move toward the pair of second convex portions 30h. The knots 48f formed by loosening the knot shape while being handled and plastically deformed by the pair of second convex portions 30h are formed as a pair of second convex portions of the pair of linear portions 48c. The knot shape is gradually hardened by the movement toward the 30h side, and the plastic deformation occurs.

In the latter half of the stroke near the bottoming position, the knot 48f of the figure eight knot is fixed, and the end 48e is fixed to the bracket body 30a as the first convex part 32d moves forward in the vehicle front-rear direction. The entire energy absorbing member 48 is stretched and plastically deformed.
Thus, in the second half of the stroke of the outer column 28 (first convex portion 32d), the pair of straight portions 48c are first handled by the pair of second convex portions 30h and plastically deformed, and the knot of the eight-letter knot is formed. The knot shape of 48f is gradually hardened and plastically deformed, and the shock absorbing load is gradually increased. In the second half of the stroke near the bottoming position, the knot 48f is firmly knotted so that the entire energy absorbing member 48 is Since the plastic deformation occurs, the shock absorption load gradually increases.

Therefore, in this embodiment as well, the shock absorbing load is gradually increased until just before the steering column (outer column 28) bottoms, and the shock absorbing load below a predetermined value can be set at the bottom.
In addition, the energy absorbing member 48 of the present embodiment forms an eight-shaped knot 48f in which wires are intertwined in a complicated manner as compared with the knot 48d of the first embodiment, so that the knot shape gradually increases. The deformation resistance at the time of becoming harder increases, and compared with the case where the energy absorbing member 48 of the first embodiment is used, the overall value of the impact load can be gradually increased while raising. .

  In the above embodiment, the central curved portion 48a of the energy absorbing member 48 is stretched over the curved surface facing the front in the vehicle front-rear direction of the first convex portion 32d of the moving bracket 32, and the pair of end curved portions 48b are The pair of second convex portions 30h of the support bracket 30 is mounted between the support bracket 30 and the moving bracket 32 by being spanned on the curved surface facing the rear in the vehicle front-rear direction, but the gist of the present invention is limited to this. Instead, the pair of second convex portions 30h are integrated with the moving bracket 32, the first convex portion 32d is integrated with the support bracket 30, and the central curved portion 48a is arranged on the front and rear of the first convex portion 32d in the vehicle. The same effect can be obtained by spanning the curved surface facing the rear in the direction and spanning the pair of end curved portions 48b on the curved surface facing the front in the vehicle front-rear direction of the pair of second convex portions 30h.

In the first embodiment, one knot 48d is formed in the middle of the straight portion 48c, and in the second embodiment, one knot 48f is formed in the middle of the straight portion 48c. However, the gist of the present invention is limited to this. However, in both the first and second embodiments, two or more knots may be formed in the middle of the straight portion 48c.
Moreover, in the said embodiment, although the 1st convex part 32d of the movement bracket 32 and the 2nd convex part 30h of the support bracket 30 were formed in the cylindrical shape, the center curved part 48a of the energy absorption member 48, and a pair of edge part curved part A shape other than the cylindrical shape may be used as long as the side in contact with 48b is a curved shape.

  In addition, a coating process is applied to a portion of the energy absorbing member 48 that contacts the central curved portion 48a, the end curved portion 48b, the first convex portion 32d and the pair of second convex portions 30h of the linear portion 48c, or grease is applied. When the coating is applied so that the friction is reduced upon contact with the first convex portion 32d and the pair of second convex portions 30h, a change in the impact load absorption characteristics of the energy absorbing member 48 can be prevented.

  Furthermore, although the cross-sectional shape of the energy absorbing member 48 is a perfect circle, other cross-sectional shapes may be used.

It is the schematic of the steering mechanism part of the motor vehicle carrying the shock absorption type steering column apparatus which concerns on this invention. It is the figure which showed the shock absorption type steering column apparatus concerning this invention from the vehicle width direction. It is an AA arrow directional view of FIG. It is a BB line arrow directional view of FIG. It is a figure which shows the plastic deformation state of the energy absorption member of 1st Embodiment in the middle stroke of a steering column. It is a figure which shows the plastic deformation state of the energy absorption member of 1st Embodiment in the stroke latter half of a steering column. It is a graph which shows the shock absorption characteristic of the shock absorption type steering column apparatus using the energy absorption member of 1st Embodiment. It is a figure which shows the principal part of the impact absorption type steering column apparatus using the energy absorption member of 2nd Embodiment. It is a graph which shows the shock absorption characteristic of the conventional shock absorption type steering column apparatus.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 11 ... Steering shaft, 12 ... Shock absorption type steering column apparatus, 13 ... Steering wheel, 14 ... Universal joint, 15 ... Intermediate shaft, 16 ... Universal joint, 17 ... Steering gear, 18 ... Tie rod, 19 ... Steering wheel, 20 ... Inner column, 22 ... body side member, 24 ... pivot pin, 26 ... column connecting bracket, 26a ... connecting linear part, 28 ... outer column (steering column), 30 ... support bracket, 30a ... bracket body, 30b ... connecting linear part 30c ... Guide groove, 30d ... Open hole, 30e ... Open hole, 30f ... Contact surface, 30g ... Step surface, 30h ... Second convex part (fixing member), 32 ... Moving bracket, 32a ... Side plate, 32b ... Up Plate, 32c ... guide rail, 32d ... first convex part (moving member), 34 ... distance bracket, 36 ... column Through hole, 40 ... Bracket side through hole, 42 ... Tilt rod, 44 ... Operation lever, 46 ... Lock mechanism, 48 ... Energy absorbing member, 48a ... Central bending part (first plastic deformation part), 48b ... End bending part (2nd plastic deformation part), 48c ... Linear part (3rd plastic deformation part), 48d, 48f ... Knot (deformation start part), 48e ... End part, 49 ... End part fixing member, 50 ... Fixing bolt, P ... Peripheral parts

Claims (2)

A steering shaft that supports the steering shaft in a freely rotatable manner and strokes forward in the longitudinal direction of the vehicle due to the impact of a collision accident, and is fixed to the vehicle body side member in the longitudinal direction of the vehicle even if a collision accident impact is input A fixed member that does not displace, a moving member fixed to the steering column, and a state in which the fixed member and the moving member are engaged with each other. In an impact absorption type steering column device comprising an energy absorbing member that absorbs a load,
One member of the moving member and the fixed member is disposed apart from each other in the vehicle width direction, and the other member of the moving member and the fixed member is disposed between the one pair of members. ,
The energy absorbing member includes a first plastic deformation portion bent at a predetermined curvature so as to follow a curved surface facing the front or the rear of the other member in the vehicle front-rear direction, and a vehicle width direction from the first plastic deformation portion. A pair of second plastic deformation portions that are bent at a predetermined curvature so as to extend along a curved surface that extends rearward or forward in the vehicle front-rear direction of the pair of one member, and the pair of second plastic deformation A metal wire provided with a pair of third plastic deformation portions that extend forward or rearward in the vehicle front-rear direction from the portion and have front or rear end portions fixed to the vehicle body side member. In addition, the shock absorbing type steering column apparatus is provided with a deformation starting portion that stretches and plastically deforms the entire energy absorbing member from the latter half of the stroke of the steering column.   The deformation start portion is formed in the middle of the pair of third plastic deformation portions, has a shape that is loosely tied in the first half of the stroke of the steering column, and a knot that becomes a tight knot in the latter half of the stroke of the steering column. The shock absorbing type steering column device according to claim 1, wherein the shock absorbing type steering column device is provided.

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