JP2002019622A - Shock absorbing steering device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a shock absorbing steering device capable of stabilizing absorbing amount of impact energy compared to a conventional capsule structure and applicable to various kinds of machines and to solve a problem that a conventional shock absorbing steering device had a complicated structure and was expensive. SOLUTION: This steering device 1 is simply constructed by combining a plate shaped simple shock absorbing plate 33 fixed on an installation seat 22 of an upper bracket 7 supporting a steering column 4 with a bolt 31 for holding. The bolt 31 breaks the shock absorbing plate 33 to absorb the impact energy. A groove 42 is formed on a surface of the shock absorbing plate 33 so that the shock absorbing plate 33 is surely broken along a breakage schedule line 44 of a bottom 43 of the groove 42. Thus, the impact energy is sufficiently absorbed. Further, a guiding surface 41 formed on the shock absorbing plate 33 guides the bolt 31 to the groove 42. Thus, positioning of the bolt 31 and the shock absorbing plate 33 can be simplified and assembly cost can be reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a steering device. In particular, the present invention relates to a shock-absorbing steering device that reduces the impact of an automobile collision.

[0002]

2. Description of the Related Art There is a so-called capsule structure as a shock absorbing structure used in a conventional shock absorbing steering device. This capsule structure is interposed between the bracket supporting the steering column and the vehicle body. The capsule structure includes a pair of holding members for holding the mounting seat of the bracket while passing the fastening bolt, a cylindrical member for passing the fastening bolt while regulating the interval between the pair of holding members, and a pair of small holes of the holding member and the bracket. And a pin for inserting the same. As the steering column and bracket move forward relative to the vehicle body during the impact action, the pins of the capsule structure are sheared, and the friction generated between the pair of sandwiching members and the bracket reduces the impact. Is done.

[0003] The above-mentioned pair of regulating members and the cylindrical member include:
Usually, it is formed of a metal such as aluminum. On the other hand, the pin is formed by injection molding a synthetic resin into the small holes in a state where the holding member and the bracket are positioned with respect to each other and the pair of small holes communicate with each other. As described above, the capsule structure has a complicated structure in which a resin-made pin is injection-molded on a metal member, so that the manufacturing cost is high.

Further, the friction mainly determining the amount of impact energy absorbed by the capsule structure greatly varies depending on the surface condition of the members that are in contact with each other, so that the amount of impact energy absorbed tends to vary from individual to individual. For this reason,
In order to reduce the variation in the amount of absorption of impact energy,
It is necessary to use high-precision parts capable of stabilizing the above-mentioned friction, and this also increases the cost.

SUMMARY OF THE INVENTION It is an object of the present invention to solve the above-mentioned technical problems and to provide a low-cost shock-absorbing steering apparatus in which the variation in shock-absorbing energy among individuals is small.

[0006]

According to the first aspect of the present invention, there is provided a bolt fixed to a vehicle body for holding a steering column relatively moved with respect to the vehicle body at the time of absorbing a shock with a predetermined holding force. And a shock absorbing plate fixed to the steering column so as to be integrally movable and made of a flat plate substantially perpendicular to the axis of the bolt, and the shock absorbing plate is divided by the bolt when the shock is absorbed. Provided is an impact-absorbing steering device, which includes an expected breaking line to be torn.

According to the present invention, the simple columnar shock absorbing plate is combined with the original column holding bolt, so that the shock absorbing structure can be simplified and the cost can be reduced. Further, since the shock absorbing structure is simple, it can be applied to various types of steering devices. Also, by mainly using the tear, it is possible to reduce the variation in the absorption amount of the impact energy among the individuals, as compared with the case where the friction is mainly used.

In particular, since the shock absorbing plate is torn along the predetermined breaking line, the amount of shock energy absorbed can be further stabilized. According to a second aspect of the present invention, there is provided the shock-absorbing steering apparatus according to the first aspect, wherein the predetermined breaking line is formed by a bottom of the groove. According to the present invention, the shock absorbing plate is easily torn at the bottom of the groove, so that the shock absorbing plate is surely torn along the expected breaking line. Therefore, the amount of impact energy absorption can be further stabilized.

According to a third aspect of the present invention, in the shock absorbing type steering apparatus according to the first or second aspect, the impact absorbing plate includes a guide surface for guiding the bolt to enter the expected breaking line. A shock absorbing steering device is provided. ADVANTAGE OF THE INVENTION According to this invention, a bolt can be made to enter into an expected breaking line smoothly and reliably.

[0010]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of a shock absorbing steering apparatus according to an embodiment of the present invention. FIG. 1 is a plan view of a steering device according to one embodiment of the present invention. In the following description, the direction along the traveling direction of the vehicle is referred to as the front-back direction, and the traveling direction is referred to as the front. Arrows indicating directions are shown in each figure. The steering device 1 includes wheels (not shown).
A steering shaft 3 for transmitting the movement of a steering wheel (not shown) for steering the steering wheel, and a steering column 4 for rotatably supporting the steering shaft 3 therethrough. A steering wheel is connected to one end (the right end in FIG. 1) of the steering shaft 3. Further, the steering device 1 has an upper bracket 7 for holding an upper portion of the steering column 4 on the vehicle body and a lower bracket 8 for holding a lower portion of the steering column 4 on the vehicle body. The steering column 4 is moved by the upper bracket 7 and the lower bracket 8 along the front-rear direction.
(Only a part is shown in FIG. 2). Further, the upper bracket 7 is provided with an impact absorbing structure 6 for absorbing impact energy at the time of impact.

When no impact is applied, the steering column 4 is held at a predetermined portion of the vehicle body by bolts 31 via the upper bracket 7 and the lower bracket 8. On the other hand, at the time of impact, the steering column 4 and the upper bracket 7 can move relative to the vehicle body. At this time, the lower bracket 8 moves the lower portion of the steering column 4 so as not to hinder the relative movement of the steering column 4. Is displaceably supported.

At the time of impact, the steering column 4 extends in the direction in which the steering column 4 extends (also in the direction in which the steering shaft 3 extends, hereinafter referred to as the axial direction).
reference. ), The impact absorbing structure 6 absorbs impact energy while moving relative to the vehicle body toward the front (to the left in FIG. 1). The upper bracket 7 is disposed at a central portion when viewed from the axial direction, and is supported by being welded and fixed to the upper outer peripheral surface of the tubular jacket of the steering column 4 and provided on both left and right sides of the support portion 21. It has a pair of flat mounting seats 22. A long hole 25 (see FIG. 3) opened rearward is formed in each mounting seat 22. Each mounting seat 22 is attached to a predetermined portion of the vehicle body by a bolt 31 at a peripheral portion of the long hole 25. An internal thread is formed in a predetermined portion of the vehicle body. When the male screw of the bolt 31 is screwed into the female screw, the mounting seat 22 is held at a predetermined portion of the vehicle body with a predetermined holding force.

The shock absorbing structure 6 of the present invention includes the above-described bolt 31 fixed to the vehicle body for holding the steering column 4 with a predetermined holding force, and the steering column 4 which moves relatively to the vehicle body when absorbing a shock. It has a shock absorbing plate 33 which is fixed so as to be integrally movable and is made of a flat plate substantially orthogonal to the axis 38 of the bolt 31. This shock absorbing plate 33
Includes an expected break line 44 which is torn by the bolt 31 when the bolt 31 is split when the impact is absorbed. When the bolt 31 tears the shock absorbing plate 33 along the line 44, the shock energy is sufficiently absorbed.

FIG. 2 is a side sectional view of the shock absorbing structure, and shows a cross section taken along line AA of FIG. FIG. 3 is an exploded perspective view of the shock absorbing structure. The shock absorbing plate 33 is formed to be long in one direction, and the longitudinal direction thereof is arranged parallel to the axial direction. The shock absorbing plate 33 has a V-shaped insertion hole 40 for passing a bolt. The insertion hole 40 is open toward one side in the longitudinal direction, which is the front side, and has a size that allows the bolt 31 to pass therethrough.

The shock absorbing plate 33 is disposed along the upper surface of the mounting seat 22 between the mounting seat 22 and a predetermined portion of the vehicle body. In this state, the insertion hole 40 of the shock absorbing plate 33 is
And the long hole 25 of the mounting seat 22 are communicated with each other, and a bolt 31 is inserted through the inside thereof. Head 35 of bolt 31
Is in contact with the lower surface of the mounting seat 22 through the washer 32, the shaft portion 36 of the bolt 31 passes through the elongated hole 25 and the insertion hole 40, and the male screw of the shaft portion 36 is screwed into the female screw of a predetermined portion of the vehicle. I have. When the bolt 31 is tightened, the mounting seat 22 and the shock absorbing plate 3 are placed between the head 35 of the bolt 31 and a predetermined portion of the vehicle.
The steering column 4 is held via the upper bracket 7 by obtaining the above-mentioned predetermined holding force by the friction generated between the respective members. When an impact force exceeding a predetermined holding force is applied, the steering column 4
Moves relative to the vehicle body.

The shock absorbing plate 33 is a flat plate made of steel. The material of the shock absorbing plate 33 is not limited to steel, and may be appropriately selected so as to obtain a desired absorption amount of shock energy. Similarly, the planned fracture line 44 can also be appropriately set so as to obtain a desired amount of impact energy absorption. The break line 44 is formed by the bottom 43 of the groove 42. The groove 42 is provided along one of the surfaces of the shock absorbing plate 33 and in the direction of relative movement.
3 along the longitudinal direction. The groove 42 may be formed on only one plate surface (see FIG. 4A) or may be formed on both plate surfaces (see FIG. 4B).

Before the impact is applied, the portions on both sides of the bottom 43 of the groove 42 sandwiching the expected breaking line 44 are connected together, but when absorbing the impact, the above-mentioned portions on both sides are connected to one end. From one another to the other end. The bottom 43 of the groove 42 forming the scheduled break line 44 has a shape in which the portion where the plate thickness is the thinnest is substantially linear, for example, a V-shaped cross section or a U-shaped cross section. As a result, a tear can be easily generated along the scheduled break line 44.

The break line 44 reaches the end of the shock absorbing plate 33 opposite to the insertion hole 40. This allows
By effectively utilizing the entire length of the shock absorbing plate 33, the amount of shock energy absorbed can be increased. The break line 44 is formed with a predetermined length from one end of the shock absorbing plate 33 on the side of the insertion hole 40 along the direction of relative movement, and does not reach the other end, but the other end. May be formed at a predetermined distance from the end of the second member. The predetermined length of the groove 42 makes the formation of the tear relatively easy, while making the split relatively difficult after the split has been formed of the predetermined length. As a result, it is possible to prevent the tear from becoming too long and prevent the relative movement distance of the steering column 4 from exceeding a predetermined value excessively.

Further, the shock absorbing plate 33 is provided with a predetermined breaking line 44.
And a guide surface 41 for guiding the entry of the bolt 31 into the vehicle. The guide surface 41 is formed in a pair at the peripheral edge of the insertion hole 40. The pair of guide surfaces 41 extend in a direction crossing each other, and virtual extension surfaces of the respective guide surfaces 41 intersect at an intersection. The direction in which the guide surface 41 extends and the groove 4
The two extending directions make the same angle for the two guide surfaces 41. Each guide surface 41 guides the relatively moving bolt 31 toward the intersection. Also, at this intersection, a groove 42
Are disposed.

A notch 45 is provided at an end of the groove 42. The notch 45 is provided in the groove 42 where the crack starts to occur.
At the end. When the bolt 31 presses the guide surface 41, the notch 45 causes a concentration of stress due to the notch effect at the end of the planned breaking line 44, and promotes generation of a tear at the end of the planned breaking line 44. As a result, the rising load at the time of absorbing the impact is suppressed, and it is possible to prevent the load from becoming excessively large.

The notch 45 is formed in a V-shape when viewed from the direction normal to the plate surface of the shock absorbing plate 33, and promotes the formation of a crack at the top of the V-shape. The V-shape of the notch 45 extends perpendicular to the plate surface of the shock absorbing plate 33, and the inside of the notch 45 is open to both sides of the shock absorbing plate 33 and the insertion hole 40. The V-shape of the notch 45 is arranged such that the angles formed by the pair of sides and the direction in which the groove 42 extends are substantially the same. The gap on the V-shaped open side of the notch 45 is smaller than the diameter of the shaft 36 of the bolt 31. The angle of the top of the V-shape is smaller than the angle at which the pair of guide surfaces 41 intersect. The shape of the notch 45 may be a substantially rectangular slit shape.

The shock absorbing plate 33 has a pair of fixing portions 47 fixed to the mounting seat 22 of the upper bracket 7. The pair of fixing portions 47 are disposed on both sides of the insertion hole 40 with the extension line of the expected break line 44 interposed therebetween. Fixed part 47
Is located at the end of the shock absorbing plate 33, which end is on the side opposite to the direction in which the tear is advanced when the shock absorbing plate 33 is torn. Fixing part 4 at the rear in the direction of travel of the rift
7 is fixed, the breach and the bolt 31 can be brought into contact with each other in a wide range, and the shock absorbing plate 33 and the bolt 31
And the impact energy can be further absorbed.

Each of the fixing portions 47 is fixed to the mounting seat 22 of the upper bracket 7 by welding. As described above, since the counterpart member to which the shock absorbing plate 33 is welded is a single member called the upper bracket 7, it is easy to weld and can contribute to a reduction in manufacturing cost. This is because when there are a plurality of mating members, it takes time to position the members during welding. FIG. 5 is a schematic view showing the operation of the shock absorbing structure.

When an impact is applied, the upper bracket 7 and the impact absorbing plate 33 move integrally with respect to the bolt 31. As shown in FIG. 5A, the bolt 31 moves along the guide surface 41, reaches the notch 45, and
A crack is formed at the end of the bottom 43 of the second (the range S1 of the crack at this time is shown in FIG. 5B). When a breach occurs, the gap between the guide surfaces 41 and the gap on the open side of the notch 45 become wider, so that the bolt 31 can enter the notch 45 (see FIG. 5B). At the same time, the split absorbs impact energy while extending along the groove 42 (see FIG. 5C. The range S2 of the split at this time is shown in FIG. 5C). And bolt 31
While being guided along the crevices formed along the groove 42 and further to the back, the bottom 43 of the groove 42 is further torn to absorb impact energy.

Further, in the shock absorbing structure 6, the shock energy is mainly absorbed by the formation of the tear, and is additionally absorbed by the friction generated between the following parts. The friction occurs between the upper surface of the shock absorbing plate 33 and a predetermined portion of the vehicle body, between the shaft portion 36 of the bolt 31 and the shock absorbing plate 33 serving as a tear, and between the washer 32 and the lower surface of the mounting seat 22 of the upper bracket 7. Occurs between As described above, according to the present embodiment, a simple flat plate-like shock absorbing plate 33 is combined with the original bolt 31 for holding the steering column 4, so that the shock absorbing structure 6 can be simplified, resulting in cost reduction. Can be achieved. Further, since the shock absorbing structure 6 is simple, it can be applied to various types of steering devices.

For example, since the shock absorbing plate 33 is substantially perpendicular to the bolt 31, the shock absorbing plate 33 can be disposed near the boundary with the vehicle body, which can be easily disposed, and can be disposed in a small space corresponding to the plate thickness. Therefore, even if the space around the steering column 4 has little room, the shock absorbing plate 3
3 can be installed. Also, by mainly using tearing, the variation in the amount of impact energy absorbed (impact absorbed energy) among individuals can be reduced and stabilized, as compared with the case mainly due to friction. That is, the amount of absorption of impact energy due to tearing is determined by the shape and material of the impact absorbing plate 33, and it is easy to stably stabilize it, whereas the amount of absorption of impact energy by friction as in the conventional capsule structure is This is because it is difficult to stabilize by changing due to the surface condition between the pair of members where friction occurs.

In particular, since the shock absorbing plate 33 is torn along the predetermined breaking line 44, the amount of shock energy absorbed can be further stabilized. This is because, assuming that an unexpected portion of the shock absorbing plate 33 is torn, the tear length and the tear load may be different from those along the break line 44. Further, a groove 42 forming a break line 44 is formed in the shock absorbing plate 33.
Since the shock absorbing plate 33 is easily torn at the bottom 43 of the groove 42, it is surely torn along the expected breaking line 44. As a result, the amount of impact energy absorption can be further stabilized.

Further, since the guide surface 41 for guiding the entry of the bolt 31 into the expected break line 44 is provided, the bolt 31 can smoothly and reliably enter the expected break line 44. Further, the guide surface 41 allows the bolt 31 to reliably enter the expected break line 44 even when the bolt 31 and the expected break line 44 are not correctly aligned. Therefore, at the time of assembly, the bolt 31 and the breaking line 4
4 can be roughly aligned, so that assembly costs and component costs can be reduced.

The bolt 31 is arranged near the end of the groove 42 so that the bolt 31 tears the portion of the shock absorbing plate 33 immediately before the traveling direction at the time of the impact action. As a result, when the shock absorbing plate 33 is torn, the plate does not have to be significantly deformed.
The moving amount of 1 is also small. Therefore, at the time of an impact operation, the bolt 31 can quickly tear the impact absorbing plate 33 with a small relative movement amount, and the inclination of the rising of the absorption amount of the impact energy can be increased.

Further, since the shock absorbing structure 6 absorbs a large amount of shock energy and is stable, the conventional capsule structure having a complicated structure can be omitted, and the cost can be further reduced. ing. The above-described shock absorbing structure 6 is for reducing the impact on the secondary side when the driver collides with the steering wheel at the time of a collision of an automobile. It may be used to reduce a primary impact acting on the wheel. In this case, the direction in which the impact is applied is reversed, so that the impact absorbing plate 33 is attached to the bolt 31 in the front-rear direction.

As shown in the sectional view of FIG. 6, the above-described shock absorbing structure 6 is used in combination with a so-called capsule structure 10 in which the mounting seat 22 of the upper bracket 7 is clamped and the mounting seat 22 is mounted on the vehicle body. You may. Capsule structure 10
Has a pair of holding portions 11 for holding the mounting seat 22 of the upper bracket 7, and a cylindrical portion 12 for passing the bolt 31 while connecting the pair of holding portions 11. The cylindrical portion 12 is fitted in a long hole 25 of the mounting seat 22. One holding portion 11
The mounting seat 22 and the mounting seat 22 are formed with small holes communicating with each other, and the resin pins 13 are provided in these small holes. The pin 13 is formed by directly injection molding into a pair of communicating small holes. Capsule structure 1
0 indicates that the mounting seat 22 is held on the vehicle body with the mounting seat 22 held therebetween until an impact is applied.
3, the mounting seat 22 is supported so as to be relatively movable forward with respect to the vehicle body. By the shearing of the pin 13, impact energy can be absorbed with a desired rising load, and thereafter, the impact energy can be continuously absorbed by friction between the holding portion 11 and the cylindrical portion 12 and the upper bracket 7. The shock absorbing plate 33 is interposed between the washer 32 and the holding portion 11 and is fixed to the lower surface of the mounting seat 22 of the upper bracket 7. In other respects, the configuration is the same as in the above-described embodiment.

In this case, the amount of impact energy absorbed is equal to the sum of the amount of impact energy absorbed by the capsule structure 10 and the amount of impact energy absorbed by the impact absorbing structure 6, so that a greater amount of impact energy can be absorbed. it can. Therefore, it is preferable for secondary-side impact absorption requiring a large amount of impact energy absorption with a limited relative movement stroke. In addition, the capsule structure 10 can be simplified, so that the cost can be reduced.

In addition, various design changes can be made without changing the gist of the present invention.

[Brief description of the drawings]

FIG. 1 is a plan view of a steering device according to an embodiment of the present invention.

FIG. 2 is a side cross-sectional view of the shock absorbing structure of the steering device of FIG. 1, and shows a cross section taken along line AA of FIG.

FIG. 3 is an exploded perspective view of the shock absorbing structure of the steering device of FIG.

FIG. 4 is a cross-sectional view of the shock absorbing plate showing an expected break line;
(A) and (b) show different embodiments.

FIG. 5 is a schematic plan view showing the operation of the shock absorbing structure, and (a) to (c) illustrate the state of shock absorption over time.

FIG. 6 is a cross-sectional view of a shock-absorbing steering device according to another embodiment, showing a cross-section when viewed from an axial direction.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Shock absorbing steering device 4 Steering column 31 Bolt 33 Shock absorbing plate 38 Bolt axis 41 Guide surface 42 Groove 43 Groove bottom 44 Expected break line 60 Body

Claims (3)

[Claims] 1. A bolt fixed to a vehicle body for holding a steering column relatively movable with respect to the vehicle body with a predetermined holding force when absorbing an impact, and a bolt fixed to the steering column so as to be integrally movable and substantially aligned with the axis of the bolt. A shock-absorbing plate composed of orthogonal flat plates, wherein the shock-absorbing plate includes a breaking line that is torn by the bolt that is divided by the bolt when absorbing the shock. . 2. The shock absorbing steering device according to claim 1, wherein the predetermined breaking line is formed by a bottom of the groove. 3. The shock-absorbing steering device according to claim 1, wherein the shock-absorbing plate includes a guide surface for guiding a bolt to enter a predetermined breaking line. apparatus.