JP2015229394A - Steering column device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a steering column device which simplifies an impact absorption structure by reducing the number of part items, and can reduce costs.SOLUTION: A jacket 4 which supports a steering shaft 3, and can be contracted in an axial line direction together with the steering shaft has an upper tube 41 and a lower tube 42. A housing 81 which accommodates a reduction gear 8 and is fixed to a vehicle body 10 has protrusions 9 which oppose an upper bracket 5 fixed to the upper tube 41 in the axial line direction, protrude to the outside of a radial direction from a part of an external periphery 82 of the housing 81, and are aligned in two rows. The upper bracket 5 has an aluminum capsule 56 which removes the upper bracket 5 from the vehicle body 10 by an impact load not smaller than a prescribed load, and absorbs the impact load by the deformation of the protrusions 9 by a front bending part 55 of the upper bracket 5 accompanied by the contraction of the upper tube 41 to a vehicle front part by the impact load.

Description

  The present invention relates to a steering column device.

  2. Description of the Related Art Conventionally, for example, a steering column device mounted on a vehicle such as an automobile includes an impact absorbing structure that absorbs part of the impact load when an impact load greater than a predetermined load is applied to the steering wheel.

  This shock absorbing structure absorbs the impact load by detaching the steering shaft connected to the steering wheel from the vehicle body by shearing the resin shear pin by the impact load and tearing the slit portion of the ripping plate. There exists a structure (for example, refer patent document 1).

Japanese Patent Laid-Open No. 10-217981

  However, the above steering column device requires not only a shear pin but also a ripping plate as an impact absorbing structure. As a result, the number of parts is increased, the structure is complicated, and the cost is increased. Therefore, the steering column device has a problem of simplifying the shock absorbing structure by reducing the number of parts and reducing the cost.

  The present invention has been made to solve such a problem, and an object of the present invention is to provide a steering column device that can simplify the shock absorbing structure by reducing the number of parts and reduce the cost. To do.

  In order to solve the above problems, the structural features of the steering column device according to claim 1 are: a steering shaft that can contract in the axial direction; and a speed reducer that decelerates the power of the electric motor and transmits it to the steering shaft. An upper bracket that is disposed on the vehicle rear side of the speed reducer and is fixed to the vehicle body. The housing that houses the speed reducer and is fixed to the vehicle body has an axis line Facing the upper bracket in a direction, projecting radially outward from a part of the outer periphery of the housing, and having a protrusion formed at least in one axial direction, the upper bracket having a predetermined load or more A detaching portion for detaching the upper bracket from the vehicle body by an impact load of the vehicle, and the steer by the impact load. As the ring shaft contracts forward of the vehicle, the upper bracket absorbs the impact load by deforming the protrusion.

  According to the steering column device of the first aspect, as the steering shaft contracts due to an impact load, the upper bracket that supports the steering shaft and separates from the vehicle body deforms the protruding portion that protrudes from the housing that houses the reduction gear. To absorb the impact load. As a result, this steering column device eliminates the need for a ripping plate that has been required in the prior art, so that the shock absorbing structure can be simplified by reducing the number of parts and the cost can be reduced.

  The structural feature of the steering column device according to claim 2 is that the protrusion is plastically processed integrally with the housing by an aluminum alloy.

  According to the steering column device of the second aspect, since the protruding portion is plastically processed integrally with the housing by the aluminum alloy, the shock absorbing structure can be simplified by reducing the number of parts and the cost can be reduced.

  ADVANTAGE OF THE INVENTION According to this invention, the steering column apparatus which can simplify the impact absorption structure of a steering column by reduction of a number of parts, and can aim at cost reduction can be provided.

It is the side view which showed schematic structure of the steering column apparatus which is one Embodiment of this invention. It is A arrow directional view of FIG.

Hereinafter, an embodiment in which a steering column device of the present invention is embodied will be described with reference to the drawings.
FIG. 1 is a side view showing a schematic configuration of a steering column device 1 according to an embodiment of the present invention. FIG. 2 is a view taken in the direction of arrow A in FIG. As shown in FIGS. 1 and 2, for example, a steering column device 1 mounted on a vehicle such as an automobile includes a steering shaft 3 to which a steering wheel 2 is connected at one end, and a jacket 4 that rotatably supports the steering shaft 3. And an upper bracket 5 that fixes the jacket 4 to the vehicle body 10 and an assist mechanism 6 that is disposed on the other end side of the steering shaft 3 and applies an operation assisting force for steering operation to the steering shaft 3.

  The steering shaft 3 has an upper shaft (not shown) and a lower shaft (not shown), and is supported in the jacket 4 so as to be rotatable about its axis and contractible in the axial direction. A steering wheel 2 is fixed to one end of the steering shaft 3 on the vehicle rear side. On the other hand, an intermediate shaft (not shown) is connected to the other end of the steering shaft 3 on the front side of the vehicle via a universal joint (not shown), and rotation (steering torque) accompanying the steering operation is racked. The steering angle of a steered wheel (not shown) is changed by being transmitted to a steered mechanism (not shown) such as an & pinion mechanism.

  The jacket 4 has an upper tube 41 disposed on the vehicle rear side and a lower tube 42 disposed on the vehicle front side, and has a double tube structure. As the steering shaft 3 contracts, the upper tube 41 contracts relative to the lower tube 42.

  The upper bracket 5 is fixed to the upper side of the vehicle front side end portion of the upper tube 41 via a U-shaped tube connection bracket (not shown) whose lower side is opened. The top plate 51 of the upper bracket 5 is fastened and fixed to the upper surface of the tube connection bracket by bolts. The upper bracket 5 is formed with a pair of vehicle body mounting portions 52 that step down from both sides of the top plate 51 in the vehicle width direction and extend in the vehicle width direction. The vehicle body attachment portion 52 is formed with bent portions 53 that bend downward from both outer sides in the vehicle width direction and extend downward. The pair of vehicle body mounting portions 52 are each formed with a substantially U-shaped cutout 54 that is open on the vehicle rear side.

  The upper bracket 5 is mounted with an aluminum capsule 56 made of an aluminum alloy that is inserted into the vehicle body mounting portion 52 from the rear side of the vehicle and clamped. The relative positions of the vehicle body attachment portion 52 and the aluminum capsule 56 sandwiching the vehicle body attachment portion 52 are regulated by shear pins 58 formed by pouring resin into four holes penetrating them. Then, a bolt (not shown) is inserted into a hole 57 formed in the center of the aluminum capsule 56 and penetrating vertically and the notch 54, and the vehicle body mounting portion 52 of the upper bracket 5 together with the aluminum capsule 56 and the vehicle body 10. Fastened and fixed to. Here, the notch 54, the aluminum capsule 56, and the shear pin 58 correspond to the separation portion of the present invention.

  The upper bracket 5 is formed with a forward bending portion 55 that extends from the vehicle front side end portion of the top plate 51 to the vehicle front side and extends further from the front end of the top plate 51 in a direction perpendicular to the axis line of the jacket 4. As a material of the upper bracket 5, for example, a hot rolled steel plate “SPHC” is used.

  The assist mechanism 6 includes an electric motor 7 and a speed reducer 8 that decelerates the power of the electric motor 7 and transmits it to the steering shaft 3. The speed reducer 8 is a worm and wheel type speed reducer, and is housed in a housing 81 that is plastic-worked with an aluminum alloy. The case of the electric motor 7 is fixed to the housing 81. The housing 81 is fastened and fixed to the vehicle body 10 by bolts (not shown) or the like.

  The housing 81 has a protruding portion 9 that protrudes outward in the radial direction, facing the front bent portion 55 of the upper bracket 5 in a part of the outer periphery 82 at the vehicle rear side end. The protrusions 9 are formed in a quadrangular shape when viewed in the axial direction, and are arranged in two rows in the axial direction. The protrusion 9 is plastically processed integrally with the housing 81.

  The housing 81 is formed with a reduced diameter portion (not shown) extending from the outer periphery 82 to the rear side of the vehicle. By fitting the tip of the lower tube 42 to the outer periphery of the reduced diameter portion, the jacket 4 and the speed reducer 8 are connected.

  At the tip of the lower tube 42, a flange 42a protruding outward in the radial direction is formed over the entire circumference. Here, as will be described later, when an impact load equal to or greater than a predetermined load is applied to the steering wheel 2, the jacket 4 contracts as the steering shaft 3 contracts. The jacket 4 contracts until the tip 41a of the upper tube 41 abuts against the flange 42a of the lower tube 42, and the contraction amount is the contraction length L. As a result, the front bent portion 55 of the upper bracket 5 fixed to the upper tube 41 when the jacket 4 contracts is at a position indicated by a two-dot chain line. Then, when the jacket 4 contracts, two rows of protrusions 9 are arranged on the trajectory along which the front bending portion 55 moves.

Next, in the steering column apparatus 1 configured as described above, an operation when an impact load greater than a predetermined load is applied to the steering wheel 2 will be described.
As shown in FIGS. 1 and 2, for example, when a driver hits the steering wheel 2 during a vehicle collision, an impact load greater than a predetermined load is applied to the steering wheel 2. Due to this impact load, a load is applied to the upper tube 41 toward the front side of the vehicle, and the shear pin 58 is sheared, so that the aluminum capsule 56 attached to the vehicle body attachment portion 52 of the upper bracket 5 is detached. For this reason, the upper bracket 5 is detached from the vehicle body 10.

  Then, the jacket 4 contracts until the upper tube 41 moves to the front side of the vehicle and the tip 41a of the upper tube 41 contacts the flange 42a of the lower tube 42. When the jacket 4 contracts, the front bending portion 55 bends and deforms the two rows of protrusions 9.

  As described above, when an impact load equal to or greater than a predetermined load is applied to the steering wheel 2, a part of the impact load is absorbed mainly by the load P1 for shearing the shear pin 58 and the load P2 for bending the protruding portion 9. Here, the shock absorbing structure that absorbs a part of the shock load has a structure in which the shear pin 58 is sheared and a structure in which the protrusion 9 is bent.

  As described above, according to the steering column apparatus 1 according to the present embodiment, the shock absorbing structure is configured by the shear pin 58 and the protrusion 9 that is plastically processed integrally with the housing 81. For this reason, in this steering column device 1, for example, a ripping plate that has been conventionally required is not required, so that the shock absorbing structure can be simplified by reducing the number of parts and the cost can be reduced.

  Further, according to the steering column device 1 according to the present embodiment, the protruding portion 9 is bent so that the leading end 41a of the upper tube 41 abuts against the flange 42a of the lower tube 42, that is, immediately before the so-called bottoming. Therefore, the load P2 before the bottom is generated. For this reason, in this steering column apparatus 1, the acceleration to the vehicle front side concerning a driver | operator before bottoming can be reduced, and a driver | operator's damage can be suppressed.

In addition, this invention is not limited to this embodiment, In the range which does not deviate from the summary of this invention, it can implement with a various form.
In the present embodiment, the projecting portion 9 is plastically processed integrally with the housing 81 by an aluminum alloy, but is not limited thereto.

  Further, in the present embodiment, the projections 9 are provided in quadrangular positions at the position before bottoming in two rows. However, the present invention is not limited to this, for example, by changing the shape, quantity, position, etc. The load generated at the time of contraction with respect to the contraction amount can be set as appropriate.

  Further, in the present embodiment, the detachment portion has the configuration of the aluminum capsule 56 and the shear pin 58, but is not limited thereto. For example, the separation portion is applied to a configuration of a resin capsule formed integrally with the protruding pin. May be.

  In the present embodiment, the projection 9 is bent and deformed by the front bending portion 55, but the present invention is not limited to this. For example, the projection 9 is applied to a configuration that is bent and plastically deformed by the front bending portion 55. May be.

  In the present embodiment, the tilt mechanism and the telescopic mechanism are not mentioned, but the present invention can be applied to any configuration regardless of whether or not the tilt mechanism and the telescopic mechanism are included.

DESCRIPTION OF SYMBOLS 1: Steering column apparatus, 2: Steering wheel, 3: Steering shaft, 4: Jacket, 5: Upper bracket, 6: Assist mechanism, 7: Electric motor, 8: Reduction gear, 9: Protruding part, 10: Car body, 41 : Upper tube, 41a: Tip, 42: Lower tube, 42a: Spear, 51: Top plate, 52: Body mounting part, 53: Bending part, 54: Notch, 55: Front bending part, 56: Aluminum capsule, 57 : Hole, 58: shear pin, 81: housing, 82: outer periphery, L: contraction length

Claims (2)

A steering shaft capable of contracting in the axial direction;
A decelerator that decelerates the power of the electric motor and transmits it to the steering shaft;
An upper bracket that rotatably supports the steering shaft and is disposed on the vehicle rear side of the speed reducer and is fixed to a vehicle body,
A housing that houses the speed reducer and is fixed to the vehicle body is opposed to the upper bracket in the axial direction, protrudes radially outward from a part of the outer periphery of the housing, and is formed in at least one axial direction. Having a protrusion
The upper bracket has a detachment part that detaches the upper bracket from the vehicle body by an impact load equal to or greater than a predetermined load.
The steering column device absorbs the impact load by the upper bracket deforming the protrusion as the steering shaft contracts forward of the vehicle due to the impact load.   The steering column device according to claim 1, wherein the protrusion is plastically formed integrally with the housing by an aluminum alloy.

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