JP2003118596A - Impact force relaxing structure for automobile steering device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a simple construction permitting the sure relaxation of an impact force given to a driver through a steering column at a secondary collision of the driver with the steering column. SOLUTION: The steering column 19 is supported on a body resting side member 9 forming a front face portion of a vehicle room 4 by a bracket 25 mounted on the cast steering column 19. The bracket 25 is integrally formed on the steering column 19. A rupture promoting portion 33 is formed on the bracket 25 for promoting rupture effected on the bracket 25 by the impact force given to the bracket 25.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an automobile in which a vehicle collides with an object in front of it (primary collision).
The present invention relates to an impact force mitigating structure in a steering device for an automobile, which is configured to reduce an impact force applied to the driver from the steering column side when the driver collides with the steering column side (secondary collision).

[0002]

2. Description of the Related Art Conventionally, Japanese Patent Application Laid-Open No. 2000-20343 has been used as a shock absorbing structure for a vehicle steering system.
3 publications.

According to the above-mentioned publication, the steering device is arranged in the front part of the vehicle compartment and extends toward the upper rear side, the steering shaft supported by the steering column, and the steering shaft. A steering wheel attached to an upper end portion, a bracket supported by a fastener on a vehicle body stationary side member forming a front surface portion of the vehicle compartment to support the steering column, and interposed between the steering column and the bracket. An impact force absorbing member that allows the steering column to move relative to the bracket by the impact force given to the stationary member on the vehicle body at the time of a primary collision is provided.

When the steering column is moved relative to the bracket by the impact force absorbing member during the primary collision of the automobile, immediately after the primary collision,
Even if the driver makes a secondary collision with the steering wheel on the steering column side, the impact force applied to the driver from the steering column side is alleviated by the relative movement of the steering column, thus protecting the driver. It is supposed to be done.

[0005]

According to the above-mentioned conventional technique, in the steering apparatus, the steering column, the bracket for supporting the steering column on the stationary member of the vehicle body, and the impact force absorbing member are separate from each other. The number of parts is large and the structure of the steering device is complicated.

The present invention has been made by paying attention to the above circumstances. When the driver collides with the steering column side in a secondary collision, the impact force applied to the driver from the steering column side is simple. Therefore, the issue is to ensure that it is alleviated.

[0007]

Means for Solving the Problems An impact force mitigating structure in a vehicle steering system of the present invention for solving the above problems is as follows.

According to the first aspect of the present invention, the steering column 19 is fixed to the body stationary member 9 forming the front surface of the vehicle compartment 4 by the bracket 25 attached to the cast steering column 19. In an impact force mitigating structure for an automobile steering device supported by 9,

A bracket 25 is integrally formed on the steering column 19,

The bracket 25 is formed with a breakage promoting portion 33 for promoting the breakage of the bracket 25 when the bracket 25 is about to break due to the impact force applied to the bracket 25.

According to a second aspect of the present invention, in addition to the first aspect, the steering column 19 to the bracket 2 are provided.
5 is projected, and the fracture promoting portion 33 is formed on the base portion 25a of the bracket 25.

The invention of claim 3 is the invention of claim 1 or 2.
In addition to the above invention, the steering column 19 is arranged so that its axis 18 extends rearward and upward, and the steering column 19 is supported by the vehicle body stationary side member 9 by upper and lower brackets 25, 25. In impact force mitigation structure for automobile steering device,

Of the upper and lower brackets 25, 25,
The breakage promoting portion 33 is formed only on the lower bracket 25.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings.

In the figure, reference numeral 1 is a one-box type automobile, and an arrow Fr indicates the front of the automobile 1.

The vehicle body 2 of the automobile 1 constitutes a lower portion of the vehicle body 3 and extends in the front-rear direction and has high strength and rigidity. The vehicle body frame 3 is supported on the vehicle body frame 3 to form an interior space as a vehicle compartment 4. The vehicle body 5 is made of sheet metal.
6 is a front window.

The body stationary member 9 made of sheet metal and forming the front surface of the vehicle compartment 4 is joined to the front plate 10 of the vehicle body 2 and the upper edge of the front plate 10 so as to cover substantially the entire width of the vehicle body 2. The front cowl 11 extends, a reinforcing panel 12 coupled to a middle portion of the front plate 10 in the vertical direction and extending over substantially the entire width of the vehicle body 2, and the front cowl 11
The vehicle body frame 3, the reinforcing panel 12, and a pedal bracket 14 that is installed to extend over the stay 13 and pivotally supports an accelerator pedal (not shown). .

A steering device 17 which is an electric power steering (EPS) is provided at the front of the vehicle body 2.

The steering device 17 is provided in the vehicle compartment 4
A steering column 19 arranged at the front part of the steering column 19 and having an axis 18 extending rearward and upward.
A steering shaft 20 supported by the steering column 19 so as to be rotatable about the shaft center 18, a steering wheel 21 fixed to the upper end of the steering shaft 20, and the steering column 19. The upper brackets 25 and 25, which are attached to and supported by the fasteners 24 on the pedal brackets 14 of the vehicle body stationary side member 9 to support the steering column 19, the lower brackets 25, 25, and the electric motor 26 supported by the steering column 19, and Steering column 19
And a worm type gear set 27 that is internally included in the electric motor 26 and connects the steering shaft 20 to the electric motor 26.

Of the upper and lower brackets 25, 25,
The insertion portion 24a of the fastener 24 formed on the upper bracket 25 is a notch that opens rearward and upward. The insertion portion 24a is removably fitted to the fastener 24 screwed into the pedal bracket 14 from the lower front side thereof, whereby the bracket 25 has a fastening force of the fastener 24. While being opposed to the (friction force), it can be detached from the fastener 24 side toward the lower front side.

On the other hand, the insertion portion 24b of the fastener 24 formed on the lower bracket 25 is simply a circular hole.

A lower end portion of the steering shaft 20 is connected to a rack gear device 30 supported by the vehicle body frame 3 via a universal joint shaft 29. The rack gear device 30 is connected to left and right front wheels which are steering wheels. ing.

The lower portion 19a of the steering column 19
Is in the shape of a pipe made of aluminum casting, the upper portion 19b is in the shape of a sheet metal pipe extending rearward and upward from the upper end of the lower portion 19a, and the lower portion 19a and the upper portion 19b are on the axis 18 above. Is located in. The electric motor 26 is supported between the upper and lower brackets 25, 25 in the axial direction of the lower portion 19a of the steering column 19 and in the axially intermediate portion of the lower portion 19a.

A pair of upper and lower brackets 25, 25 are provided on the left and right sides, respectively, and each has a rectangular flat plate shape having a substantially constant thickness and has substantially the same size. The upper and lower brackets 25, 25 are integrally formed by casting on the upper and lower ends of the lower portion 19a of the steering column 19, and from the lower portion 19a toward the left and right outer sides in the width direction of the vehicle body 2. It is projected.

When a driver seated behind the steering column 19 and the steering shaft 20 in the passenger compartment 4 steers the steering wheel 21, the operating force is freely transmitted from the steering wheel 21 to the steering shaft 20. It is transmitted to each front wheel through the joint shaft 29 and the rack gear device 30, and these front wheels are steered. In this case, with the steering operation of the steering wheel 21 by the driver, the electric motor 26 is automatically driven to assist the driver's operation.

When the vehicle 1 undergoes a primary collision, the impact promoting force applied to the bracket 25 causes the fracture promoting portion 33 to accelerate the fracture when the bracket 25 is about to fracture. It is molded on the surface (rear surface) of 25a.

The breakage promoting portion 33 is formed in each bracket 25.
To the lower portion 19a of the steering column 19 is provided in a corner portion, and the cross section of the corner portion is machined so as to have a substantially right-angled shape instead of the arc shape at the time of casting. Is the above bracket 2
5 is formed over the entire width direction (direction substantially orthogonal to the protruding direction of the bracket 25). In the above case, the breakage promoting portion 33 may have an acute angle shape that is less than a right angle.

According to the above structure, the bracket 25 attached to the cast steering column 19 is fastened to the stationary member 9 forming the front surface of the vehicle compartment 4 by the fastener 24.
And the steering column 19 is supported by the stationary member 9 of the vehicle body.
The bracket 25 is integrally formed with the base plate 9.

Therefore, since the steering column 19 and the bracket 25 are integrally formed with each other, the number of parts of the steering device 17 is reduced and the structure of the steering device 17 is simplified.

A breakage promoting portion 33 is formed on the bracket 25 to promote the breakage of the bracket 25 when the bracket 25 is about to break due to the impact force applied to the bracket 25.

Here, as described above, the steering column 19 and the brackets 25 are integrally formed by casting, and since the brackets 25 have lower toughness as compared with the case where they are formed of, for example, a steel plate, It has the property of being relatively easily broken by impact force.

Therefore, as described above, each bracket 2
Since the breakage promoting portion 33 is formed on the bracket 5, if the impact force is applied to the bracket 25 during the primary collision of the automobile 1, the impact force causes the bracket 25 to break more reliably. The support of the steering column 19 with respect to the vehicle body stationary side member 9 is released (see FIG. 2).
Medium dashed line).

Therefore, immediately after the primary collision, the steering wheel 21 on the steering column 19 side is provided.
Even if the driver has a second collision, the impact force applied to the driver from the steering wheel 21 on the steering column 19 side is mitigated because the support of the steering column 19 on the stationary body side member 9 is released. Therefore, the driver is more surely protected.

That is, according to the above configuration, when the driver makes a secondary collision with the steering wheel 21 on the steering column 19 side, the impact force applied to the driver from the steering column 19 side is further reduced by the simple configuration. It will certainly be alleviated.

Further, the steering column 19 is above,
The lower brackets 25, 25 support the vehicle body stationary side member 9, and below the steering column 19, the vehicle body frame 3 having strength and rigidity higher than that of the vehicle body stationary side member 9 extends in the front-rear direction. The rack gear device 30 is disposed on the vehicle body frame 3 and is supported by the vehicle body frame 3.

In general, when the vehicle 1 has a primary collision, the vehicle body frame 3 moves rearward together with the rack gear device 30 more than the deformation dimension in which the vehicle body stationary side member 9 plastically deforms rearward. Since it becomes larger, the above-mentioned steering column 19 will be used at the time of a primary collision.
The rack gear device 30 is relatively displaced rearward with respect to the lower end of the steering gear, and the rack gear device 30 is moved to the lower end of the steering column 19 via the universal joint shaft 29 and the lower end of the steering shaft 20. It will give an impact force.

Therefore, the upper and lower brackets 25, 25 described above
Of these, since the lower bracket 25 breaks faster, immediately after the primary collision, in addition to the impact force on the lower end of the steering column 19, the weight of the lower portion 19a of the steering column 19, and particularly, The upper bracket 2 being detached and / or broken from the fastener 24 side due to the weight of the electric motor 26, which is a heavy object.
5, the lower portion 19a of the steering column 19 pivots rearward (arrow A in FIG. 2), while the upper portion 19b of the steering column 19 located above the upper bracket 25 is raised. The steering wheel 21 which is the upper end portion on the steering column 19 side is rotated forward (arrow B in FIG. 2).

The direction of the forward rotation of the steering wheel 21 is determined by the steering wheel 21.
Since the direction coincides with the direction in which the driver makes a secondary collision, the impact force applied from the steering wheel 21 to the driver at the time of the secondary collision can be more reliably alleviated.

Further, as described above, each of the brackets 25 is projected from the steering column 19, and the breakage promoting portion 33 is formed on the base portion 25a of each of the brackets 25.

Here, when an impact force is applied to the bracket 25, stress concentration tends to occur in the base portion 25a of the bracket 25, and in cooperation with this, the breakage promoting portion 33 causes the bracket 25 to move. Is more reliably broken.

Therefore, the above-mentioned various effects are further promoted.

As shown by the alternate long and short dash line in FIG. 1, the fracture promoting portion 33 may be a notch or a groove, which is formed by machining.

As described above, according to the illustrated example, the steering column 19 is arranged so that its axis 18 extends rearward and upward, and the steering column 19 is mounted on the stationary member of the vehicle body by the upper and lower brackets 25, 25. In the impact force mitigating structure of the automobile steering device supported by 9, the breakage promoting portion 33 may be formed only on the lower bracket 25 of the upper and lower brackets 25, 25.

With the above arrangement, the lower bracket 25 of the upper and lower brackets 25, 25 is more reliably and more quickly broken by the impact force of the primary collision.

Further, the steering column 19 and the bracket 25 may be made of cast iron, and one that is slightly enlarged along the outer shape of the steering column 19 is wholly or partially machined. The steering column 19 may be formed by molding.

The breakage promoting portion 33 may be formed as it is by casting, or may be formed only on a part of the bracket 25 in the width direction. Further, the insertion portion 24a of the upper bracket 25 may be a simple circular hole.

[0047]

The effects of the present invention are as follows.

According to a first aspect of the present invention, a vehicle body stationary side member forming a front portion of a vehicle interior is supported by a bracket mounted on a cast steering column to support the steering column on the vehicle body stationary side member. The impact force mitigation structure of the steering device for automobiles,

A bracket is formed integrally with the steering column.

Therefore, since the steering column and the bracket are integrally formed with each other, the number of parts of the steering device is reduced, and the structure of the steering device is simplified.

Further, a breakage promoting portion for promoting the breakage of the bracket when the bracket is about to break due to the impact force applied to the bracket is formed on the bracket.

Here, as described above, the steering column and the bracket are integrally formed by casting, and the bracket has a lower toughness as compared with the case where the bracket is formed of, for example, a steel plate. It has the property of being relatively easy to break.

Therefore, as described above, the breakage promoting portion is formed in the bracket. Therefore, when an impact force is applied to the bracket during the primary collision of the automobile, the impact force causes the bracket to move more securely. When the steering column is broken, the support of the steering column for the stationary member of the vehicle body is released.

Therefore, even if the driver collides with the steering column side immediately after the primary collision, the steering column side is released from the steering column side as much as the support of the steering column to the stationary member of the vehicle body is released. The impact force applied to the driver is mitigated, and the driver is more reliably protected.

That is, according to the above-mentioned invention, when the driver makes a secondary collision with the steering column side, the impact force given to the driver from the steering column side can be more reliably alleviated by the simple structure.

According to the second aspect of the present invention, the bracket is projected from the steering column, and the fracture promoting portion is formed on the base portion of the bracket.

Here, when an impact force is applied to the bracket, stress concentration tends to occur at the base portion of the bracket, and in conjunction with this, the fracture promoting portion ensures more reliable fracture of the bracket. To be made.

Therefore, the effect of the above-mentioned claim 1 is further promoted.

According to a third aspect of the present invention, the steering column for an automobile is arranged such that the axis of the steering column extends rearward and upward, and the steering column is supported by the body stationary side member by upper and lower brackets. In the impact force relaxation structure in the device,

Of the upper and lower brackets, the fracture promoting portion is formed only on the lower bracket.

Therefore, due to the impact force of the primary collision, the lower bracket of the upper and lower brackets is more reliably and more quickly broken.

Therefore, immediately after the primary collision, the lower part of the steering column pivots rearward about the upper bracket due to its own weight of the lower part of the steering column, while the upper bracket does not rotate. The upper end portion on the steering column side, which is located higher than the above, rotates forward.

The direction of forward rotation of the upper end portion on the steering column side coincides with the direction when the driver makes a secondary collision with the upper end portion on the steering column side. Sometimes, the impact force applied to the driver from the steering column side is more reliably alleviated.

[Brief description of drawings]

1 is a cross-sectional view taken along the line 1-1 of FIG.

FIG. 2 is a side view of a steering device.

FIG. 3 is a partially enlarged partial sectional view of FIG.

FIG. 4 is a view taken along line 4-4 of FIG.

[Explanation of symbols]

1 car 2 car body 3 body frame 4 car compartment 5 Body 9 Body rest side member 17 Steering device 18 axis 19 Steering column 19a lower part 19b upper part 20 steering shaft 21 steering wheel 24 Fastener 25 bracket 25a base 26 electric motor 33 Fracture promoting part

Claims (3)

[Claims] Claim: What is claimed is: 1. An impact in a steering apparatus for a vehicle, wherein a bracket mounted on a cast steering column supports a steering column for a vehicle body stationary side member forming a front portion of a vehicle compartment, the steering column being supported by the vehicle body stationary side member. In the force relaxation structure, a bracket is integrally formed on the steering column, and a rupture promoting portion that promotes the rupture when the bracket is about to break due to the impact force applied to the bracket is formed on the bracket for an automobile. Impact force mitigation structure for steering device. 2. The impact force mitigating structure for a vehicle steering system according to claim 1, wherein the bracket is projected from the steering column, and the breakage promoting portion is formed on a base portion of the bracket. 3. The impact force mitigation of a steering device for an automobile, wherein the steering column is arranged so that its axis extends rearward and upward, and the steering column is supported by the body stationary side member by upper and lower brackets. In the structure, the impact force alleviating structure in a steering apparatus for an automobile according to claim 1 or 2, wherein the fracture promoting portion is formed only on a lower bracket among the upper and lower brackets.