JP2000313340A - Steering column device with electric power steering device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the vibration generated within a housing from being trans mitted to a steering wheel by interposing a cushion member between members to be adjacently connected to each other. SOLUTION: A steering shaft 1 comprises an inner shaft 2 and an outer shaft 3, and the front end of the inner shaft 2 is connected to the rear end of the outer shaft 3 through a spline connection part having small sliding resistance, which is covered with a synthetic resin easy to slip. Accordingly, the whole length of the inner shaft 2 and the outer shaft 3 is contracted in the event of a collision, and the transmission of vibration from the outer shaft 3 to the inner shaft 2 is also prevented. A cylindrical steering column 4 having the steering shaft 1 inserted thereto comprises an outer column 5 and an inner column 6 which are combined in telescopic form, and has a so-called collapsible structure in which the whole length is contracted, when an axial impact is applied, while absorbing the energy by the impact.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement of a steering column device with an electric power steering device for reducing a steering force by utilizing a rotational force of an electric motor, and vibration is transmitted to a steering wheel during traveling. It is to prevent that.

[0002]

2. Description of the Related Art A steering force assisting device called a power steering device is widely used to reduce a force (steering force) required to turn a steering wheel when changing a course. In small vehicles such as mini vehicles, electric motors are generally used as a power source of a power steering device. Such an electric power steering device includes a steering shaft for fixing a steering wheel to a rear end, a steering column through which the steering shaft can be inserted, a housing connected to a front end of the steering column, and a housing supported by the housing. And an electric motor for applying a force in the rotation direction to the steering shaft when energized. At the time of steering, the electric motor applies an auxiliary torque to the steering shaft via a gear type speed reducer such as a worm speed reducer provided in the housing, and provides a steering force for rotating the steering wheel. We aim at reduction.

[0003]

In the case of a gear type speed reducer constituting an electric power steering apparatus, there is an unavoidable gap (backlash) inside such as a meshing portion between a worm and a worm wheel. For this reason, the meshing portion may rattle due to vibration during traveling, and the resulting new vibration may be transmitted from the housing to the steering wheel via the steering column and the steering shaft. The new vibration generated at such a meshing portion is different from the vibration at the time of traveling, and it is desired to eliminate or attenuate the vibration in order to give the driver an uncomfortable feeling. The steering column device with an electric power steering device of the present invention has been invented in view of such circumstances.

[0004]

All of the steering column devices with an electric power steering device according to the present invention have a steering wheel fixed to the rear end, similarly to a conventionally known steering column device with an electric power steering device. Steering shaft, a steering column through which the steering shaft can be inserted, a housing coupled to the front end of the steering column, and a rotational force applied to the steering shaft by energization by being supported by the housing. An electric motor.

[0005] In particular, in the steering column device with the electric power steering device according to the first aspect, the shock is generated in the housing by interposing a cushioning member between adjacent members that are coupled to each other. Vibration is prevented from being transmitted to the steering wheel. or,
In the steering column device with the electric power steering device according to the second aspect, the housing is made of a magnesium alloy to prevent the vibration generated in the housing from being transmitted to the steering wheel.

[0006]

In any case, the electric power steering apparatus of the present invention configured as described above can prevent the vibration generated in the housing from being transmitted to the steering wheel, thereby preventing the driver from feeling uncomfortable. .

[0007]

FIG. 1 shows a first embodiment of the present invention in which the present invention is applied to the structure described in Japanese Utility Model Laid-Open No. 6-87142. A steering wheel (not shown) is fixed to the upper end, and the steering shaft 1 rotated in the torsional direction by the operation of the steering wheel connects the inner shaft 2 and the outer shaft 3 to each other by a spline engaging portion. It is configured to be freely transmitted and displaceable in the axial direction. In particular, in the case of the present invention, the steering shaft 1 has a spline having a small sliding resistance, in which the front end of the inner shaft 2 and the rear end of the outer shaft 3 are coated with a slippery synthetic resin or the like. They are connected by an engaging part. Therefore, while the inner shaft 2 and the outer shaft 3 shorten the overall length at the time of collision,
The transmission of vibration from the outer shaft 3 to the inner shaft 2 is prevented.

A tubular steering column 4 through which the steering shaft 1 is inserted is formed by combining an outer column 5 and an inner column 6 in a telescopic manner.
When an impact in the axial direction is applied, the so-called collapsible structure is adopted, in which the overall length is reduced while absorbing the energy due to the impact. In particular, in the case of the present invention, the front end of the outer column 5 and the rear end of the inner column 6 are
They are fitted to each other via a rubber sleeve 7 as a buffer member. That is, the sleeve 7 is sandwiched between the inner peripheral surface of the front end portion of the outer column 5 and the outer peripheral surface of the rear end portion of the inner column 6 while being elastically pressed.

In such a steering column 4, an intermediate portion and a lower end portion thereof are formed by an upper support bracket 8 and a lower support bracket 9, such as a lower surface of a dashboard or the like.
Part of 0 is supported. Upper support bracket 8 of these
Is formed by bending a metal plate, and is fixed to the outer peripheral surface of the intermediate portion of the outer column 5 constituting the steering column 4 by welding or the like. Such an upper support bracket 8 is supported on the vehicle body 10 via a locking member 11 made of a slippery material.

An electric motor 12 serving as a power source of the power steering device is supported by a housing 13 connected to the front end of the steering column 4. A worm (not shown) fixed to the output shaft of the electric motor 12 and a worm wheel (not shown) fixed to the front outer peripheral surface of the steering shaft 1 mesh with each other,
It constitutes a worm wheel type gear reducer. In addition, a force in the rotational direction can be applied to the steering shaft 1 when the electric motor 12 is energized. The front end of the inner column 6 constituting the steering column 4 is connected and fixed to the rear end surface of the housing 13. The lower support bracket 9 is provided between the housing 13 and the vehicle body 10.

When an impact is applied to the steering wheel due to a secondary collision caused by a collision accident, the impact is immediately transmitted to the steering shaft 1 and the steering column 4, and the two members 1, 4 are strongly pushed in the axial direction. It is.
In this manner, the impact force applied in the axial direction between the steering shaft 1 and the steering column 4 causes the coupling force between the inner shaft 2 and the outer shaft 3, the coupling force between the inner column 6 and the outer column 5, and the upper support bracket. When the sum of the coupling force between the steering shaft 8 and the locking member 11 becomes larger, the upper support bracket 8 comes out of the locking member 11, and the steering shaft 1 and the steering column 4 can be displaced. Then, the steering wheel on which the driver's body collides is displaced forward to prevent a large impact from being applied to the driver's body.

Further, in the case of the electric power steering apparatus according to the present invention, the housing 1 is moved with the vibration during traveling.
It is possible to prevent the specific vibration generated by the rattling of the gear type speed reducer provided in 3 from being transmitted to the steering wheel. That is, the vibration generated in the housing 13 and transmitted to the inner column 6 is attenuated by the rubber sleeve 7 and is hardly transmitted to the outer column 5. Therefore, the above specific vibration is not transmitted from the outer column 5 to the inner shaft 2. Also, from the gear reducer to the outer shaft 3
The vibration transmitted to the inner shaft 2 is attenuated on the basis of the displacement of the spline engagement portion.
The above specific vibration is not transmitted. Thus, it is possible to prevent the above-mentioned specific vibration from being transmitted to the steering wheel fixed to the rear end of the inner shaft 2, thereby preventing the driver from feeling uncomfortable.

Next, FIG. 2 shows a second embodiment of the present invention.
3 to 3 examples are shown. In each of these examples, the outer peripheral surfaces of the inner shafts 2a and 2b and the outer shafts 3a and 3a
b has a non-circular shape such as an oval {FIG. 2 (A)} or a triangle {FIG. 2 (B)}, and the outer peripheral surfaces of the inner shafts 2a and 2b and the outer shaft 3a. A rubber sleeve 14 is sandwiched between the inner peripheral surface of the inner sleeve 3b and the inner sleeve 3b while being elastically compressed. With such a configuration, transmission of vibration between the inner shafts 2a, 2b and the outer shafts 3a, 3b can be more reliably prevented. Since the configuration and operation of the other parts are the same as those of the first example described above, illustration and description of the equivalent parts are omitted.

FIG. 3 shows a fourth embodiment of the present invention.
An example is shown. In the case of this example, the front end of the inner column 6 constituting the steering column 4 is connected to the housing 1.
3 is externally fitted via a sleeve 16 made of rubber to a connection cylinder 15 provided on the rear end face. In this state, this sleeve 1
6 is in a state of being elastically compressed between the inner peripheral surface of the front end portion of the inner column 6 and the outer peripheral surface of the connection tubular portion 15. In the case of this example, the sleeve 16 prevents the specific vibration generated by the rattling of the gear type reduction gear provided in the housing 13 due to the vibration during traveling from being transmitted to the steering wheel. . In the illustrated example, the sleeve 7 is also provided at the fitting portion between the outer column 5 and the inner column 6, but the sleeve 7 may be omitted.

FIG. 4 shows a fifth embodiment of the present invention.
An example is shown. The steering column 4b constituting the structure of the present example is entirely constituted by one tube, and has a structure in which the entire length is not reduced even in the event of a collision. Instead, in the case of the present example, the steering column 4b is formed as a lower support bracket 9a for supporting the housing 13 with respect to the vehicle body 10 while being plastically deformed based on an impact load applied to the front accompanying the secondary collision. The one that allows it to be displaced is used. Other configurations and operations are the same as those of the fourth embodiment.
Since this is the same as in the example, description of the equivalent parts will be omitted.

FIG. 5 shows a fifth embodiment of the present invention.
As an example, a case where the present invention is applied to a structure described in Japanese Patent Application Laid-Open No. 10-76958 is shown. In the case of this example, the housing 13a is mounted on the vehicle body 10a by a support bracket that allows the steering column 4a to be displaced forward while being plastically deformed based on an impact load applied to the front along with the secondary collision. 17 support.
The front end of the steering column 4a is constituted by the inner column 6a, and the rear half is constituted by the outer column 5a. A coupling ring 18 externally fitted and fixed to the front end of the inner column 6a is abutted against the rear end surface of the housing 13a via a rubber buffer plate 19 and fixed with a plurality of screws 20. In the case of this example, the shock-absorbing plate 19 prevents the specific vibration generated by the rattling of the gear type speed reducer provided in the housing 13a accompanying the vibration during traveling from being transmitted to the steering wheel. I do. The configuration and operation of the other parts are described in the above-mentioned Japanese Patent Application Laid-Open No. H10-76958, and are not the gist of the present invention, so that detailed description will be omitted.

FIG. 6 shows a seventh embodiment of the present invention.
An example is shown. This embodiment shows a case where the present invention is applied to a structure having a tilt mechanism for adjusting the height position of a steering wheel. For this reason, in the case of the present embodiment, a coupling plate 22 fixed to a support cylinder 21 swingably supported at the front end of the inner column 6a is provided on the rear end surface and the rear end upper surface of the housing 13b with a rubber buffer plate. 19a
And fixed by a plurality of screws 20. The support cylinder 21 and the front end of the inner column 6a are swingably displaceably coupled to each other by a pair of concentric horizontal shafts provided at two positions on the outer peripheral surface of the support cylinder 21 on the diametrically opposite side. ing. Also, the steering shaft 1
The front end of a and the rotation transmission shaft provided in the housing 13b are connected by a universal joint provided inside the support cylinder 21.

The housing 13b is fixed to the vehicle body by the lower support bracket 9b, while the lifting bracket 24 fixed to the outer column 5a constituting the steering column 4a is fixed to the upper support bracket 8a fixed to the vehicle body. , Supported vertically. The lifting bracket 2 is mounted on the upper support bracket 8a.
A tilt lever 23 is provided to fix or release the fixing of the lever 4. The tilt steering mechanism including the tilt lever 23 has been conventionally known, and is not related to the gist of the present invention.
In the case of this example, the shock-absorbing plate 19a prevents the specific vibration generated by the rattling of the gear type reduction gear provided in the housing 13b due to the vibration during traveling from being transmitted to the steering wheel. I do.

Each of the embodiments described above corresponds to the first embodiment, but the structure of each of the embodiments can implement the invention described in the second embodiment. That is, the housing 13 having the structure described in FIGS.
The housing 13a in the structure shown in FIG. 5 and the housing 13b in the structure shown in FIG. 6 are made of a magnesium alloy including the main body and the lid, respectively. Magnesium alloys have better vibration absorption performance (vibration damping characteristics) than aluminum alloys generally used for forming the housings 13, 13a, and 13b. Therefore, in each of the above examples,
Sleeves 14, 16 for absorbing vibration, buffer plate 1
Even when the parts 9 and 19a are omitted, it is possible to prevent the specific vibration generated in the gear reduction mechanism from being transmitted to the steering wheel. Of course, if the sleeves 14 and 16 and the buffer plates 19 and 19a are provided together, the characteristic vibration absorption characteristics will be more excellent.

In carrying out the invention described in claim 2, the housings 13, 13a, 13b and the lower support brackets 9, 9a, 9b for mounting the housings 13, 13a, 13b to a vehicle body are combined. They can be made together. Magnesium alloys have better dimensional stability associated with die-casting than aluminum alloys, so post-processing after forming is not required, and processing costs can be reduced. Furthermore, since the recyclability is good, it is not only preferable from the viewpoint of environmental measures, but also can contribute to cost reduction in a long term.

[0021]

The steering column apparatus with the electric power steering apparatus according to the present invention is constructed and operated as described above, so that vibrations which give a feeling of strangeness to the driver are prevented from being transmitted to the steering wheel. A steering device having an operational feeling can be realized.

[Brief description of the drawings]

FIG. 1 is a partial longitudinal sectional side view showing a first example of an embodiment of the present invention.

FIG. 2 is a view showing the second and third examples and corresponding to an enlarged cross section AA in FIG. 1;

FIG. 3 is a partial longitudinal sectional side view showing the fourth example.

FIG. 4 is a partial longitudinal side view showing the fifth example.

FIG. 5 is a partial longitudinal sectional side view showing the sixth example.

FIG. 6 is a partial vertical sectional side view showing the seventh example.

[Explanation of symbols]

 1, 1a Steering shaft 2, 2a, 2b Inner shaft 3, 3a, 3b Outer shaft 4, 4a Steering column 5, 5a Outer column 6, 6a Inner column 7 Sleeve 8, 8a Upper support bracket 9, 9a, 9b Lower support bracket DESCRIPTION OF SYMBOLS 10, 10a Vehicle body 11 Locking member 12 Electric motor 13, 13a, 13b Housing 14 Sleeve 15 Connection cylinder part 16 Sleeve 17 Support bracket 18 Coupling ring 19, 19a Buffer plate 20 Screw 21 Support cylinder 22 Connection plate 23 Tilt lever 24 Lifting bracket

Claims (2)

[Claims] 1. A steering shaft for fixing a steering wheel to a rear end, a steering column through which the steering shaft can be inserted, a housing connected to a front end of the steering column, and a housing supported by the housing and energized. In the steering column device with an electric power steering device provided with an electric motor that applies a rotational force to the steering shaft, by interposing a buffer member between adjacent members that are coupled to each other, A steering column device with an electric power steering device, wherein vibration generated in the housing is prevented from being transmitted to the steering wheel. 2. A steering shaft for fixing a steering wheel to a rear end, a steering column through which the steering shaft can be inserted, a housing connected to a front end of the steering column, and supported by the housing and energized by the housing. A steering column device with an electric power steering device provided with an electric motor for applying a rotational force to the steering shaft, wherein the housing is made of a magnesium alloy, so that vibrations generated in the housing are generated by the steering. A steering column device with an electric power steering device, wherein transmission to a wheel is prevented.