JP2003040115A - Shock absorber for steering device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To efficiently absorb impact energy based on secondary collision. SOLUTION: A tubular column to be provided on the outside of a steering shaft 3 is divided into two parts in a vertical direction to form an upper column 21 and a lower column 22. Terminals 211, 221 of the divided parts of these two columns 21, 22 are installed to be slidable with each other. A cylindrical collar 1 is provided in an engagement area between the upper and lower columns 21, 22, which is formed to be plastically deformed in the axial direction with the relative sliding motions of the columns 21, 22 when a predetermined impact load is inputted between the two columns 21, 22. The collar 1 formed of an elastomer material comprises a cylindrical portion 11 and peripheral ribs 12 provided at both ends and at the middle of the cylindrical portion 11.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an impact energy absorbing device for a steering column, and more particularly to absorbing impact energy for a so-called secondary collision caused by a driver's chest or the like colliding with a steering wheel. It is intended to be a shock energy absorbing device.

[0002]

2. Description of the Related Art As a conventional impact energy absorbing device of this type, for example, the one described in Japanese Patent Laid-Open No. 7-76279 can be cited. In this type, the steering shaft is vertically divided into two parts, and the two divided shafts are connected by a plastic shear pin or the like. A two-divided steering column and a spacer installed between the upper and lower steering columns to relatively slide the upper and lower columns are provided. And
At the time of the secondary collision, first, the shear pin provided at the steering shaft is cut by the impact energy at the time of the collision. Also,
At the same time, the vertically divided steering column is relatively slid with a spacer interposed therebetween. The relative sliding motion of the upper and lower steering columns with the spacer sandwiched therebetween absorbs the impact energy at the time of the secondary collision.

[0003]

By the way, in the above-mentioned conventional one, the absorbing action of the impact energy due to the secondary collision is caused by the relative sliding motion between the contact surfaces of the spacers provided between the upper and lower steering columns. It is supposed to be done. Therefore, the energy absorption capability is determined by the sliding frictional resistance between the spacer surface and the upper and lower steering column contact surfaces. Against this background, the spacer is made of a material in which a plastic material such as Teflon (registered trademark) resin is coated on the surface of a metal mesh material, and the sliding friction resistance value (force) is naturally limited. . Further, there is a problem in the impact energy absorption mode that the impact absorption load changes abruptly with respect to the displacement (deformation) of the member. In order to solve such a problem, when a shock load is input, the cylindrical collars installed between the upper and lower steering columns are plastically deformed. It is an object (problem) of the present invention to provide an absorber.

[0004]

In order to solve the above-mentioned problems, the following measures are taken in the present invention. That is, according to the first aspect of the invention, in the impact absorbing device for a steering device, the column tube provided on the outside of the steering shaft is made of a two-part type which is vertically divided into two parts. The divided end portions of the divided upper and lower columns are engaged with each other so as to be slidable with each other, and a predetermined impact is applied between the upper and lower columns at the engaging portions of the upper and lower columns. The configuration is such that a cylindrical collar formed so as to plastically deform in the axial direction when a load is input is adopted.

By adopting such a structure, in the present invention, when the impact energy due to the secondary collision is propagated to the engaging portions of the upper and lower columns, the columns move relative to each other. At the same time, the cylindrical collars provided between the upper and lower columns are plastically deformed mainly in the buckling deformation in the axial direction. Due to the plastic deformation action mainly due to this buckling deformation,
The impact energy due to the secondary collision is absorbed.

Next, the invention according to claim 2 will be described. This one is also the same as the one described in claim 1 in the basic point. The feature is that a collar which is plastically deformed is provided at the connecting portion of the two-division type steering shaft. That is, in the present invention, regarding the impact absorbing device for a steering device, the steering shaft is made of a two-part type that is divided into two parts in the vertical direction, and the end parts of the divided parts of the upper and lower shafts. They are engaged with each other so as to be slidable relative to each other, and when a predetermined impact load is input between the upper and lower shafts at the engaging portions of the upper and lower shafts, the shafts move in the axial direction thereof. The configuration is such that a cylindrical collar formed so as to be plastically deformable is provided.

By adopting such a structure, also in the case of the present invention, as in the case of the above-mentioned claim 1, the effect of absorbing the impact energy with respect to the secondary collision can be smoothly performed. Specifically, in the present invention, the impact energy absorbing action is performed by the plastic deformation mainly based on the buckling deformation of the cylindrical collar provided between the two divided steering shafts.

Next, the invention according to claim 3 will be described. Also in this case, the basic points are the same as those described in claim 1 or claim 2. That is, in the present invention, in the impact absorbing device for a steering device according to claim 1 or 2, the collar is formed in a cylindrical shape, and both ends thereof have a predetermined height and thickness. A circumferential rib having a height, and at least one or more circumferential ribs having substantially the same shape as those provided at both end portions are provided at an intermediate portion in the axial direction thereof. I decided to take it. By adopting such a configuration, in the present invention, when the impact load (force) is input, the cylindrical collar buckles and deforms at the cylindrical portion formed between the circumferential ribs. As a result, the entire cylindrical collar is uniformly plastically deformed. As a result, the impact energy resulting from the secondary collision is efficiently absorbed.

Next, the invention according to claim 4 will be described. Also in this case, the basic points are the same as those in claims 1 to 3 above. That is, in the present invention, in the shock absorbing device for a steering device according to the first to third aspects, the collar is formed of a predetermined elastomer material. By adopting such a configuration, also in the case of the present invention, as in the case of the above-mentioned claim 1 to claim 3, the cylindrical collar is buckled and deformed in the axial direction, so that the overall structure is improved. It becomes plastically deformed evenly. As a result, the impact energy of the secondary collision can be efficiently absorbed, and the driver's chest can be effectively protected.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention will be described with reference to FIGS. As shown in FIG. 1, the configuration according to the present embodiment is a tubular column provided outside the steering shaft 3, and the upper column 21 and the upper column 21 are divided into two in the vertical direction. The lower column 22 and the split terminal portions 211, 221 of these two columns 21, 22 are installed so as to be slidable relative to each other, and at the engaging portions of the upper and lower columns 21, 22, respectively. The two columns 21 and 2 that are provided
When a predetermined impact load is input between the two columns,
It is basically composed of a cylindrical collar 1 formed so as to be plastically deformed in the axial direction in accordance with the relative sliding movement of Nos. 1 and 22.

In such a structure, the collar 1 provided at the engaging portions of the upper and lower columns 21 and 22 is basically cylindrical as shown in the upper half of FIG. Based on the tubular portion 11 having a predetermined diameter, the axial end portion thereof has a predetermined protrusion amount in the radial direction and has a certain degree in the axial direction. A circumferential rib 12 formed so as to have a width is provided. Then, at a predetermined position in the axial direction of the tubular portion 11 having such a configuration, at least one or more circumferential ribs 12 having substantially the same shape as those provided at the both end portions,
Preferably, a plurality of them are provided at equal intervals. In addition, the main collar 1 having such a structure is formed entirely of an elastomer material having a predetermined rigidity and elasticity.

Further, the collar 1 is, as shown in FIG.
Generally, it is provided at an engaging portion of both columns 21 and 22 divided into two, but in some cases, as shown in FIG.
As shown in FIG. 3, it is possible to consider one provided at the steering shaft 3. In this case, the column tube 2 is divided into two, and is formed by the upper column 21 and the lower column 22, which are slidable at the divided end portions 211 and 221. Is engaged. The steering shaft 3 installed inside these column tubes 2 is of a two-division type like the column tubes, that is, the upper shaft 31 and the lower shaft 32.
It is formed by and. Further, both shafts 31 and 32 are engaged with each other so that they can slide with each other, as in the case of the column tube 2. Between the shafts 31 and 32 as described above, there is a tubular portion 11 'having a predetermined diameter as shown in the lower half of FIG. 3, and both end portions or intermediate portions of the tubular portion 11' are provided. Circumferential rib 1 having a predetermined shape on a portion or the like
A collar 1'having 2'is intended to be installed. The collar 1'in this case has a smaller diameter (radius) than the one provided at the column tube 2 as shown in the upper half of FIG. Circumferential rib 12 'provided on 11'
The installation interval is also short.

In either case, the collar 1 is provided on the column tube 2 side (see FIG. 1) or the steering shaft 3 side (see FIG. 2). A spline engagement portion 33 is provided between the upper shaft 31 and the lower shaft 32 of the shaft 3. As a result, the steering force from the steering handle is smoothly transmitted to the steering gear mechanism side between the shafts 31 and 32.

Next, the operation mode and the like of the present embodiment having such a configuration will be described. First, when a secondary collision occurs, the columns 21 and 2 in the two-divided state having the configuration shown in FIG. 1 or FIG.
The impact energy due to the secondary collision is propagated to both ends of the collar 1 provided at the engaging portions of the steering shafts 31 and 32 or 2 or the steering shafts 31 and 32.
By inputting this impact energy, the color 1,
1'buckles and deforms in the axial direction at its cylindrical portions 11 and 11 ', and plastically deforms so as to be crushed in the axial direction as a whole. Due to the axial plastic deformation of the collars 1, 1 ′ mainly due to such buckling deformation, energy absorption is performed at the collars 1, 1 ′. Specifically, the adjacent ribs 12
The tubular portion 11 (11 ′) between (12 ′) is crushed into a bellows shape in order from the handle side (upper column 21, upper shaft 31 side). The energy absorbing action at this time is as shown in FIG.
With respect to the deformation amount (displacement amount) in the axial direction of, the energy absorption amount at each position does not change significantly, and the energy absorption action is performed in a relatively uniform state. As a result, the impact energy due to the secondary collision is efficiently absorbed at the collars 1 and 1 ', so that the driver's chest is effectively protected.

[0015]

According to the present invention, in the shock absorbing device for a steering device, the column tube provided on the outside of the steering shaft is of a two-part type which is vertically divided into two parts.
The divided end portions of the divided upper and lower columns are engaged with each other so as to be slidable with each other, and a predetermined impact is applied between the upper and lower columns at the engaging portions of the upper and lower columns. Since the configuration is such that a cylindrical collar formed so as to plastically deform in the axial direction when a load is input is adopted, the impact energy due to the secondary collision is generated by the engaging portions of the upper and lower columns. When it is propagated to the column, the cylindrical collar provided between the upper and lower columns will undergo plastic deformation mainly in buckling deformation in the axial direction, and this buckling deformation will occur. The impact energy due to the secondary collision comes to be absorbed by the plastic deformation action mainly.

In the present invention, the above color is
In the case where it is provided at the connecting portion of the steering shaft that is divided into the upper and lower parts, a predetermined impact load is input between the upper and lower shafts at the engaging portions of the upper and lower shafts. At the same time, the collar is plastically deformed in its axial direction, whereby the impact energy for secondary collision is smoothly absorbed.

Further, in the present invention, the collar is formed in a cylindrical shape, and circumferential ribs having a predetermined height and thickness are provided at both ends thereof.
Further, at least one or more circumferential ribs having substantially the same shape as those provided at the both end portions are provided at the intermediate portion in the axial direction, so that the collar When an impact load (force) is input to the cylindrical collar, the cylindrical collar will undergo buckling deformation at the cylindrical portion formed between the circumferential ribs, and the entire cylindrical collar will be uniform. Began to plastically deform. As a result, the impact energy resulting from the secondary collision has been efficiently absorbed.

In the present invention, the above color is
Since it is made of a predetermined elastomer material, when an impact load (force) is input to the collar, the cylindrical collar will undergo buckling deformation in the axial direction, and the overall collar will be even. It began to plastically deform in the state. As a result, the impact energy of the secondary collision can be efficiently absorbed, and the driver's chest can be effectively protected.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view showing an overall configuration of an embodiment according to the present invention.

FIG. 2 is a vertical sectional view showing the overall configuration of another embodiment according to the present invention.

FIG. 3 is a half cross-sectional view showing the overall structure of a collar forming a main part of the present invention.

FIG. 4 is a diagram (graph) showing an impact energy absorption mode in the present invention.

[Explanation of symbols]

1 color (for column tube installation) 1'color (for mounting steering shaft) 11 tubular part 11 'tubular part 12 circumferential ribs 12 'circumferential rib 2 column tubes 21 Upper Column 211 Split unit terminal unit 22 Lower Column 221 Dividing unit Terminal unit 3 steering shaft 31 Upper shaft 32 Lower shaft 33 Spline engagement part

Claims (4)

[Claims] 1. A column tube provided outside a steering shaft is divided into two in the vertical direction.
The split type end portions of the upper and lower columns, which are divided into two parts, are engaged with each other so as to be slidable with each other. A shock absorbing device for a steering device, characterized in that a cylindrical collar formed so as to be plastically deformed in the axial direction when a predetermined shock load is input between the upper and lower columns. . 2. The steering shaft is made of a two-part type which is divided into two parts in the vertical direction, and the divided end parts of the two parts of the upper and lower shafts are engaged with each other so that they can slide. When the predetermined impact load is applied between the upper and lower shafts, the engaging portions of the upper and lower shafts are formed so as to be plastically deformable in the axial direction thereof. A shock absorbing device for a steering device, characterized in that a cylindrical collar is provided. 3. The shock absorbing device for a steering device according to claim 1 or 2, wherein the collar is formed in a cylindrical shape, and a predetermined height and thickness are provided at both ends thereof. And a circumferential rib having substantially the same configuration as that provided at the both end portions at the intermediate portion in the axial direction thereof. Shock absorbing device for steering system. 4. The shock absorbing device for a steering device according to claim 1, wherein the collar is made of a predetermined elastomer material.