JP2004082868A - Shock absorbing type steering column device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a shock absorbing type steering column device achieving stable shock absorbing performance in spite of having a tilt mechanism and a telescopic mechanism. <P>SOLUTION: Between a head part 83 of an adjusting bolt 51 and an outer side surface of a left stay 42, an operation lever 89 is provided as well as an engagement rack mechanism 85 as a tilt holding means and a cam mechanism 87. The engagement rack mechanism 85 is composed of a fixed side rack 91 welded with the left stay 42, and a movable side rack 97 energized in a separating direction from the fixed side rack 91 through a lifter spring 93 doubling as a guide. The cam mechanism 87 is composed of a fixed side cam 101 with the movable side rack 97 of the engagement rack mechanism 85, and a movable side cam 103 engaged with the operation lever 89. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a shock-absorbing steering column device having a tilt mechanism and a telescopic mechanism, and more particularly, to a technique for achieving stable shock-absorbing performance.
[0002]
[Prior art]
When a vehicle collides with another vehicle, a building, or the like, the driver may cause a secondary collision with the steering wheel due to inertia. In recent years, in order to prevent the driver from being injured in such cases, an impact-absorbing steering column device is widely used together with a seat belt, an airbag, and the like. There are various types of shock absorbing mechanisms employed in the shock absorbing type steering column device. However, when a driver makes a secondary collision, the steering column collapses (shortens) together with the steering shaft, and at that time the collision energy is reduced. Are generally of the double tube type.
[0003]
This type of shock absorbing type steering column device is, for example, interposed between an outer column held on a vehicle body side bracket, an inner column slidably fitted to the outer column, and an outer column and the inner column. The inner column enters the outer column when an axial load of a predetermined value or more acts on the outer column. At that time, the impact energy is absorbed by the impact energy absorbing means. You.
[0004]
On the other hand, since a steering device of an automobile is used (steered) by an unspecified number of drivers, it is desirable that the position of a steering wheel can be adjusted according to an individual's physique or driving posture. In order to respond to such demands, not only passenger cars but also freight cars and the like often employ a tilt mechanism or a telescopic mechanism.
[0005]
The tilt mechanism is a mechanism for vertically adjusting the position of the steering wheel, and includes a tilt pivot for swingably supporting the steering column and a tilt holding means for holding the steering column at a desired position (swing angle). Etc. The telescopic mechanism is a mechanism for adjusting the position of the steering wheel in the front-rear direction (axial direction of the steering shaft). (Telescopic holding means) for holding the steering shaft by (extension / contraction amount).
[0006]
In a steering device provided with a tilt mechanism and a telescopic mechanism, as described in Utility Model Registration No. 2584258 (hereinafter referred to as prior art) and the like, in order to facilitate operation and the like, tilt holding means and telescopic holding are provided. The mainstream is to provide a tilt / telescopic holding means integrated with the means, and to drive the tilt / telescopic holding means with a single operation lever. In the prior art steering apparatus, when the occupant makes a secondary collision with the steering wheel, the steering column falls off the vehicle body, and the steel plate impact energy absorbing member fixed to the steering column deforms (curls) and tears (rips). ) To absorb the impact energy.
[0007]
On the other hand, in a steering system for an automobile, an electric power steering device (hereinafter, referred to as EPS) using an electric motor as a power source has been actively used in recent years. In the EPS, the in-vehicle battery is used as the power source of the electric motor, so that there is no direct engine drive loss, and the electric motor is started only at the time of steering assist, so that the running fuel efficiency is reduced (the engine drive loss related to the alternator). In addition to this, it has features that electronic control can be performed very easily. The EPS is classified into a column-assist type, a rack-assist type, and the like according to a mounting portion of the electric motor. At present, a column-assist type, which is superior in manufacturing cost and installation space, is mainly used.
[0008]
[Problems to be solved by the invention]
When the tilt / telescopic holding means driven by the single operation lever described above is applied to a double-tube type shock absorbing steering column device, the following problems may occur.
[0009]
Normally, in a telescopic mechanism attached to a double tube type shock absorbing type steering column device, both collapse and telescopic of the steering column are performed by relative movement between an outer column and an inner column. Therefore, if the telescopic holding force of the steering column is set small to achieve a smooth collapse, the tilt holding force also decreases in accordance with the telescopic holding force, and when the occupant makes a secondary collision with the steering wheel, the steering column is tilted. And jumped up, and the impact energy might not be absorbed.
[0010]
Also, if the tilt holding force is set to a large value to solve this problem, the telescopic holding force will also increase according to the tilt holding force, and when the occupant makes a secondary collision with the steering wheel, the steering column will have a large telescopic holding force There was a possibility that the collapse could not be performed smoothly and the impact energy could not be absorbed.
[0011]
On the other hand, in the prior art steering apparatus, the steering column falls off when the occupant makes a secondary collision with the steering wheel. However, when the column assist type EPS described above is employed, the following problem occurs. That is, since the steering column is provided with an electric motor, a speed reduction mechanism, and the like constituting the EPS, the momentary movement at the time of the secondary collision is hindered by an increase in the inertial mass, and the collapse is not performed smoothly. was there. There is also a method in which the EPS mechanism is not moved, and only the part on the steering wheel side of the EPS mechanism is dropped off and collapsed. In this case, however, since the EPS mechanism is not moved, a sufficient collapse stroke after falling off is obtained. There was a problem that it could not be secured.
[0012]
The present invention has been made in view of the above circumstances, and has as its object to provide a shock-absorbing steering column device that realizes stable shock-absorbing performance while including a tilt mechanism and a telescopic mechanism.
[0013]
[Means for Solving the Problems]
In order to solve the above problem, according to the first aspect of the present invention, the steering shaft is rotatably supported, collapsed by a predetermined collapse load, tilted around a tilt pivot, and further telescopically moved with the steering shaft. A steering column, energy absorbing means for absorbing a secondary collision energy of an occupant at the time of a vehicle collision according to the collapse of the steering column, tilt holding means for holding the steering column at a predetermined angular position, and the steering column In a shock absorbing type steering column device, comprising: a telescopic holding means for holding the camera at a predetermined axial position; and operating means for simultaneously operating the tilt holding means and the telescopic holding means. Retention of arm proposes what was set larger than the holding force of the steering column by the telescopic holding means.
[0014]
According to a second aspect of the present invention, there is provided the shock absorbing steering column device according to the first aspect, wherein the tilt holding means is a meshing rack mechanism provided between the vehicle body side bracket and the steering column. .
[0015]
According to a third aspect of the present invention, in the shock absorbing steering column device of the first aspect, the tilt holding means is a multi-plate friction engagement mechanism provided between the vehicle body side bracket and the steering column. Suggest.
[0016]
According to a fourth aspect of the present invention, in the shock absorbing steering column device according to the first to third aspects, the telescopic holding means includes an outer column swinging around the tilt pivot, and the outer column slidably mounted on the outer column. It is proposed that the inner column fitted therein and the holding mechanism for reducing the diameter of the outer column are constituent elements.
[0017]
According to a fifth aspect of the present invention, in the shock absorbing type steering column device according to the first to fourth aspects, the energy absorbing means is externally fitted and press-fitted into the steering column, and is attached to the steering column during the collapse movement. The present invention proposes an annular member that relatively moves.
[0018]
According to a sixth aspect of the present invention, there is provided the shock absorbing steering column device according to the fifth aspect, wherein the annular member is fitted around the inner column and doubles as a stopper when the steering column is telescopically operated. .
[0019]
According to a seventh aspect of the present invention, there is provided the shock absorbing type steering column device according to any of the first to sixth aspects, further comprising an electric assist mechanism attached to the steering column and assisting a steering force of the steering wheel. I do.
[0020]
According to the shock absorbing steering column device of the present invention, it is possible to hold the steering column with an appropriate telescopic holding force while sufficiently increasing the tilt holding force. A smooth collapse of the steering column is realized.
[0021]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a side view showing a vehicle cabin side portion of the steering device according to the first embodiment of the present invention. 2 is a side view of the shock absorbing steering column device according to the embodiment, FIG. 3 is a sectional view taken along line AA in FIG. 2, and FIG. 4 is a sectional view taken along line BB in FIG. is there.
[0022]
As shown in these figures, the steering column 1 is supported by a cross member 7 as a vehicle body structural member via an upper bracket 3 and a lower bracket 5. The steering column 1 includes an upper column 13 for rotatably holding a steering upper shaft 9 having a telescopic function and a collapse function via a bearing 11, and a lower column equivalent member 15 on which the upper column 13 is slidably fitted. And an electric assist mechanism 17 integrated with the tip of the lower column equivalent member 15 as main constituent members.
[0023]
The electric assist mechanism 17 includes an electric motor 21, a reduction gear housing 23, an output shaft 25, a torque sensor (not shown), and the like. In the case of the present embodiment, the lower column equivalent member 15 and the reduction gear housing 23 are integrally formed products made of an aluminum alloy, and the front center of the reduction gear housing 23 is provided at the lower end of the lower bracket 5 with a pivot pin (tilt pivot). It is swingably connected via 31. In FIG. 1, reference numeral 35 denotes a steering intermediate shaft, which is connected to the tip of the output shaft 25 via a universal joint 37.
[0024]
A steering wheel 41 is attached to the rear end of the steering upper shaft 9. When the driver turns the steering wheel 41, the rotational force is increased by the electric assist mechanism 17 and then the output shaft 25 is turned on. The power is transmitted to a steering intershaft 35 and further transmitted to a steering gear under the vehicle body via a lower-side universal joint (not shown).
[0025]
As shown in FIG. 4, the fixing bracket 3 is a welded structure product made of a steel plate, and is formed by connecting left and right stays 42 and 43 having a substantially L-shape by a connection plate 45. The right and left stays 42 and 43 are provided with arc holes 47 and 49 having the pivot pin 31 as a center. The adjust bolt 51 penetrates the arc hole 47 of the left stay 42 and the arc holes 49 of the right stay 43. , A guide bolt 53 penetrates. The left and right stays 42 and 43 may be formed with long holes of the same size instead of the arc holes 47 and 49.
[0026]
As shown in FIGS. 3 and 4, an annular groove 61 is formed at a rear portion of the lower column-equivalent member 15, and a substantially U-shaped clamp 63 is loosely fitted into the annular groove 61 from above. The left and right lower ends (open ends) are connected by retaining bolts 65.
[0027]
The right end of the clamp 63 in FIG. 4 abuts against the inner surface of the right stay 43, and the right side of the clamp 63 is screwed with a male screw portion 71 of a guide bolt 53 penetrating through the arc hole 49 of the right stay 43. In FIG. 4, reference numeral 73 denotes a collar portion of the guide bolt 53, and reference numeral 75 denotes a guide pin portion of the guide bolt 53. In the case of the present embodiment, since the width of the collar portion 73 is larger than the thickness of the right stay 43, the clamp 63 can freely move up and down with respect to the right stay 43 even when the guide bolt 53 is fastened. On the other hand, the guide pin portion 75 of the guide bolt 53 passes through a through hole 77 formed in the lower column equivalent member 15 and a guide hole 79 formed in the upper column 13.
[0028]
On the other hand, the left end of the clamp 63 in FIG. 4 has a predetermined gap with the inner surface of the left stay 42, and the male screw portion 81 of the adjusting bolt 51 penetrating the arc hole 47 of the left stay 42 is provided on the left side of the clamp 63. Is screwed. An operation lever 89 is interposed between the head 83 of the adjustment bolt 51 and the outer surface of the left stay 42, in addition to the meshing rack mechanism 85 and the cam mechanism 87 as tilt holding means.
[0029]
The meshing rack mechanism 85 includes a fixed rack 91 welded to the left stay 42 and a movable rack 97 urged in a direction away from the fixed rack 91 via a lifter spring 93 also serving as a guide. Have been. The cam mechanism 87 includes a fixed cam 101 engaged with the movable rack 97 of the meshing rack mechanism 85 and a movable cam 103 engaged with the operation lever 89.
[0030]
As shown in FIG. 3, the lower column-equivalent member 15 is provided with distance portions 105 and 107 respectively before and after the annular groove 61 (in the horizontal direction in FIGS. 2 and 3), and these distance portions 105 and 107 are provided. Are pressed against the inner surfaces of the left and right stays 42, 43. The lower column-equivalent member 15 is provided with a slit 109 on the lower surface of the rear portion thereof, and reduces the diameter when the pressing force acts from right and left to hold the upper column 13. In the case of the present embodiment, the holding force of the upper column 13 by the lower column equivalent member 15 is set relatively small.
[0031]
As shown in FIGS. 2 and 3, an EA ring 111 serving as a shock absorbing means is press-fitted into the upper column 13 behind the fixed bracket 3. In the case of the present embodiment, the EA ring 111 is disposed at a distance S1 to the lower column equivalent member 15 in the state of FIG. Further, the guide pin portion 75 of the guide bolt 53 described above is relatively movable by a distance S2 with respect to the tip of the guide hole 79 in the state of FIG. That is, the upper column 13 can enter the lower column-equivalent member 15 with the distance S1 and can exit with the distance S2, which is a telescopic stroke.
[0032]
Further, since the guide pin portion 75 of the guide bolt 53 can be moved relative to the rear end of the guide hole 79 by the distance S3 in the state of FIG. The distance S4 in which the upper column 13 can move after the contact is S3-S1, which is the shock absorbing stroke.
[0033]
Hereinafter, the operation of the first embodiment will be described.
When the position of the steering wheel 41 becomes inappropriate due to a change of the driver or the like, in the steering device of the first embodiment, the driver first turns the operation lever 89 clockwise. Then, the movable cam 103 engaged with the operation lever 89 rotates relatively to the fixed cam 101, and the axial dimension of the cam mechanism 87 decreases. As a result, the movable rack 97 biased by the lifter spring 93 is separated from the fixed rack 91, the fixing by the meshing rack mechanism 85 is released, and the steering column 1 can be tilted about the pivot pin 31.
[0034]
Further, when the axial dimension of the cam mechanism 87 is reduced, the pulling force acting between the left and right stays 42 and 43 via the clamp 63 is also eliminated, and the pressing force of the inner surfaces of the left and right stays 42 and 43 against the distance portions 105 and 107 is reduced. Disappears. As a result, the lower column equivalent member 15 expands in diameter due to its elasticity and loses the tightening force on the upper column 13, so that the upper column 13 can be telescopically moved.
[0035]
When the driver finishes adjusting the position of the steering wheel 41 by tilting or telescopically turning the steering column 1, the driver turns the operation lever 89 counterclockwise. Then, since the axial dimension of the cam mechanism 87 increases, the movable rack 97 meshes with the fixed rack 91 in the meshing rack mechanism 85, and the steering column 1 is fixed in the tilt direction. At the same time, a tensile force is generated between the left and right stays 42 and 43 via the clamp 63, and the distance portions 105 and 107 are pressed by the left and right stays 42 and 43, whereby the lower column equivalent member 15 is reduced in diameter, and the upper column is reduced. 13 is fixed in the telescopic direction.
[0036]
On the other hand, when a running vehicle collides with another vehicle or an obstacle on the road, the driver secondary collision collides with the steering wheel 41 due to inertia, and a large collapse load acts on the upper column 13. Since the holding force of the lower column equivalent member 15 for holding the upper column 13 is relatively small, the upper column 13 enters the lower column equivalent member 15 and the collapse of the steering column 1 is started. When the upper column 13 enters the lower column-equivalent member 15 by a predetermined amount, the EA ring 111 abuts and locks on the rear end of the lower column-equivalent member 15, and thereafter the collapse occurs as the EA ring 111 is pressed into the upper column 13. proceed. As a result, the impact energy is absorbed by the press-fit resistance of the EA ring 111, and the injury to the driver is suppressed.
[0037]
In this embodiment, the holding force of the upper column 13 by the lower column equivalent member 15 is relatively small, but the steering column 1 is firmly held by the meshing rack mechanism 85. Therefore, even at the time of the secondary collision of the driver with the steering wheel 41, a problem such as the jumping of the steering column 1 does not occur, and the above-described impact energy is smoothly absorbed by the EA ring 111. Further, since the electric assist mechanism 17 does not move during the collapse of the steering column 1, the occupant does not receive a large impact due to its inertial mass, and does not become a hindrance factor when the collision energy is absorbed.
[0038]
FIG. 5 is a side view of a main part of the steering column device according to the second embodiment, and FIG. 6 is a cross-sectional view taken along the line CC in FIG. The overall configuration of the present embodiment is the same as that of the above-described first embodiment, and a description of overlapping mechanisms and operations will be omitted.
[0039]
In the second embodiment, a pair of multi-plate frictional engagement mechanisms 121 and 123 are used as tilt holding means. That is, two friction plates 125 are fixed to the outer surfaces of the left and right stays 42 and 43, respectively, by a pair of upper and lower rivets 127, and a disk-shaped friction ring 129 is interposed between the friction plates 125. ing. An arc hole 131 having the pivot pin 31 as a center is formed in the friction plate 125, and the adjustment bolt 51 and the guide bolt 53 pass through the arc hole 131 and the friction ring 129. Further, the clamp 63 is divided into left and right pieces 133 and 135 and fastened and integrated by a pair of bolts 137. In addition, a long hole of the same size may be formed in the friction plate 125 instead of the arc hole 131.
[0040]
Also in the case of the present embodiment, when the operation lever 89 is loosened, the axial dimension of the cam mechanism 87 decreases, and the pressure contact force between the friction plate 125 and the friction ring 129 in the multi-plate friction engagement mechanism 121 disappears. In addition, the clamp 63 moves to the right in FIG. 6 by a predetermined amount, and the pressing force between the friction plate 125 and the friction ring 129 in the multi-plate friction engagement mechanism 123 also disappears. As a result, the fixing by the two-plate friction engagement mechanisms 121 and 123 is released, and the steering column 1 can be tilted about the pivot pin 31. Further, when the operation lever 89 is tightened, the axial dimension of the cam mechanism 87 increases, a pressing force is generated between the friction plate 125 and the friction ring 129, and the steering column 1 is moved by the multi-plate friction engagement mechanisms 121 and 123. Firmly fixed. Other operations of the present embodiment are the same as those of the above-described first embodiment.
[0041]
FIGS. 7 to 9 are longitudinal cross-sectional views of essential parts showing first to third modifications of the second embodiment.
In the first modified example shown in FIG. 7, the steering column 1 has a steel plate welded structure, and a distance bracket 143 is welded and integrated below the column tube 141. The two-plate friction engagement mechanisms 121 and 123 are structured to be tightened by a nut 145 fixed to the operation lever 89 and an adjustment bolt 51. Further, the second modified example shown in FIG. 8 has substantially the same configuration as the first modified example, but the lower column equivalent member 15 is made of an aluminum alloy. The third modified example shown in FIG. 9 has substantially the same configuration as the second modified example, but the two-plate friction engagement mechanisms 121 and 123 each have three friction plates 125. ing. The operation of these modifications is the same as that of the second embodiment.
[0042]
This concludes the description of specific embodiments, but aspects of the present invention are not limited to the above embodiments. For example, in each of the above embodiments, the present invention is applied to a shock absorbing steering column device having a column assist type electric assist mechanism. It may be applied to a device having a hydraulic assist mechanism. Further, the tilt holding means and the telescopic holding means are not limited to those described in the above embodiment, and energy absorbing means for plastically deforming a steel plate or a steel wire or a steel ball between an upper column and a lower column may be used. It is possible to adopt the one mounted. In addition, the entire configuration and the like of the steering column device can be appropriately changed without departing from the gist of the present invention.
[0043]
【The invention's effect】
As described above, according to the shock absorbing steering apparatus of the present invention, the steering shaft is rotatably supported, collapsed by a predetermined collapse load, tilted about a tilt pivot, and further tilted. A steering column that moves telescopically with the shaft, energy absorbing means for absorbing secondary collision energy of an occupant during a vehicle collision in accordance with the collapse of the steering column, and tilt holding means for holding the steering column at a predetermined angular position And a telescopic holding means for holding the steering column at a predetermined axial position, and an operating means for simultaneously operating the tilt holding means and the telescopic holding means. By means Since the holding force of the steering column is set to be larger than the holding force of the steering column by the telescopic holding means, it is possible to hold the steering column with an appropriate telescopic holding force while sufficiently increasing the tilt holding force. This makes it possible to realize a smooth collapse of the steering column when the occupant makes a secondary collision with the steering wheel, thereby improving the occupant's secondary collision safety.
[Brief description of the drawings]
FIG. 1 is a side view showing a passenger compartment side portion of a steering device according to a first embodiment.
FIG. 2 is a side view of the shock absorbing steering column device according to the embodiment.
FIG. 3 is a sectional view taken along line AA in FIG. 2;
FIG. 4 is a sectional view taken along line BB in FIG. 2;
FIG. 5 is a side view of a main part of a steering column device according to a second embodiment.
6 is a sectional view taken along the line CC in FIG.
FIG. 7 is a longitudinal sectional view of a main part showing a first modification of the second embodiment.
FIG. 8 is a vertical sectional view of a main part showing a second modification of the second embodiment.
FIG. 9 is a vertical sectional view of a main part showing a third modification of the second embodiment.
[Explanation of symbols]
1 Steering column 3 Upper bracket 5 Lower bracket 9 Steering upper shaft 13 Upper column 15 Lower column equivalent member 17 Electric assist mechanism 23 Reduction gear housing 31 Pivot pin 41 ‥‥ steering wheel 42 ‥‥ left stay 43 ‥‥ right stay 47, 49 ‥‥ arc hole 51 ‥‥ adjustment bolt 53 ‥‥ guide bolt 61 ‥‥ annular groove 63 ‥‥ clamp 75 ‥‥ guide pin part 75
77 ‥‥ through hole 79 ‥‥ guide hole 85 ‥‥ meshing rack mechanism 87 ‥‥ cam mechanism 89 ‥‥ operating lever 91 ‥‥ fixed side rack 97 ‥‥ movable side rack 101 ‥‥ fixed side cam 103 ‥‥ movable side cam 105, 107 {Distance section 111} EA ring 121, 123} Multi-plate friction engagement mechanism 125> Friction plate 129> Friction ring 131> Arc hole 141> Column tube 143> Distance bracket 145} ‥nut

Claims (7)

A steering column that rotatably supports the steering shaft, collapses by a predetermined collapse load, tilts around a tilt pivot, and moves telescopically with the steering shaft,
Energy absorbing means for absorbing occupant secondary collision energy at the time of a vehicle collision according to the collapse of the steering column;
Tilt holding means for holding the steering column at a predetermined angular position,
Telescopic holding means for holding the steering column at a predetermined axial position,
An impact-absorbing steering column device including an operating unit that simultaneously operates the tilt holding unit and the telescopic holding unit,
An impact-absorbing steering column device, wherein a holding force of the steering column by the tilt holding means is set to be larger than a holding force of the steering column by the telescopic holding means. 2. The shock absorbing type steering column device according to claim 1, wherein the tilt holding means is a meshing rack mechanism provided between the vehicle body side bracket and the steering column. 2. The shock absorbing type steering column device according to claim 1, wherein said tilt holding means is a multi-plate type frictional engagement mechanism provided between a vehicle body side bracket and said steering column. The telescopic holding means includes an outer column swinging around the tilt pivot, an inner column slidably fitted in the outer column, and a holding mechanism for reducing the diameter of the outer column. The shock-absorbing steering column device according to any one of claims 1 to 3, characterized in that: 5. The energy absorbing device according to claim 1, wherein the energy absorbing device is an annular member that is fitted and pressed into the steering column and that moves relative to the steering column during the collapse movement. 6. Item 2. The shock-absorbing steering column device according to item 1. 6. The shock absorbing steering column device according to claim 5, wherein the annular member is fitted on the inner column and also functions as a stopper when the steering column is telescopically operated. The shock absorbing type steering column device according to any one of claims 1 to 6, further comprising an electric assist mechanism attached to the steering column and provided for assisting a steering force of the steering wheel.

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