JP2002114159A - Steering column device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a steering column device capable of improving a driver's safety in case of a collision and realizing decrease in number of components. SOLUTION: When an automobile collides with some other automobile or an obstacle on a road at medium-high speed, an ECU 37 first supplies an ignition current to a gas generator 59 of a column retract mechanism 47. When the column retract mechanism 47 is operated, an outer column 41 is retracted forward by a designated amount together with a steering wheel 11. After that, the ECU 37 supplies an ignition current to an inflator 18 for deploying an air bag. Whereupon, while the air bag is developed and inflated, a gap between the steering wheel 11 and a driver 21 is secured enough because the outer column 41 is retracted forward at that time, whereby the rear of the air bag is prevented from strongly striking the driver's face and breast.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a steering column device provided with a column driving means, and more particularly to a technique for improving driver safety and reducing the number of components in a collision.

[0002]

2. Description of the Related Art When an automobile collides with another automobile, a building, or the like, the driver sometimes makes a secondary collision with the steering wheel due to inertia. In recent years, in order to prevent the driver from being injured in such a case, in addition to the shock absorbing steering shaft and the shock absorbing steering column device, airbags and seat belt pretensioners have been widely adopted in passenger cars and the like in such cases. In a shock absorbing type steering column device, when a driver makes a secondary collision, the steering column separates with the steering shaft. Usually, the steering column collapses simultaneously with the steering shaft, and at that time, shock energy is absorbed. As a specific example,
As described in JP-A-35527, a ball type in which a metal ball is interposed between an outer column and an inner column and a plastic groove is formed on the inner peripheral surface of the outer column and the outer peripheral surface of the inner column at the time of collapse. Etc. are used. Also,
The airbag is such that a bag made of a nylon cloth or the like is housed in a steering pad or the like, and is deployed and inflated using a gas generator (inflator) at the time of a collision, thereby preventing a driver from hitting the steering wheel. . The seat belt pretensioner is provided with a winding mechanism at the base of the seat belt, and winds up the seat belt using a gas generator (gas generator) at the time of collision. Restrict forward movement.

[0003]

The airbag expands and inflates in a very short time on the basis of an output signal from an impact sensor or the like at the time of a collision, but the following problems are caused by this. Was. Normally, the capacity (volume when inflated) of the airbag is set on the assumption that a driver of a standard size drives a vehicle in a standard posture. However, when the driver is a small woman with a short arm, the distance between the steering wheel and the driver tends to be smaller than an expected value by pulling the steering column or advancing the seat. . In this state, if the airbag is suddenly deployed due to the collision of the automobile, the rear surface of the airbag hits the driver's face and chest, and the spectacle wearer may suffer unexpected damage. Generally, the distance between the steering wheel and the driver's body is determined by the NHTSA (National Highway) in the United States.
As described in a collision test report of Traffic Safety Administration, etc., it is desirable that the height be 25.4 cm (10 inches) or more.

[0004] Therefore, starting with Patent No. 2596200,
British Patent GB 2340457A and German Patent DE 195
No. 42491C1, International Publication WO98 / 22325
A technique for solving these problems has been proposed in Japanese Patent Application Publication No. H11-163873. The devices described in these documents allow the forward movement of the steering column and the switching of the collapse load to be performed at the time of collision in accordance with the internal pressure of the airbag body, the presence or absence of a seat belt, and the like. In addition to the actuators used for the switching of the above, a sensor for detecting a collision, an ECU (Electronic Control Unit) for arithmetically processing various information, and the like are configured. However, these devices require relatively expensive sensors and ECs.
Since U is provided independently of the ECU such as an airbag, it is inevitable that the number of constituent parts is large and the apparatus cost is increased. In addition, since the position control of the steering column is performed independently of the deployment control of the airbag, the forward movement of the steering column does not end when the airbag is deployed, and the rear face of the airbag hits the driver's face and chest with the aforementioned problem. Could not be solved.

Further, in the above-described shock absorbing type steering column device, the steering column collapses when a predetermined collapse load is applied. However, this causes the following problem. Usually, the collapse load is set based on the kinetic energy of a driver having a standard weight colliding with the steering wheel at a predetermined speed. However, when the vehicle collides at such a low speed that the airbag does not deploy, the kinetic energy of the driver naturally becomes small, so that even if the driver makes a secondary collision with the steering wheel, the steering column hardly collapses and the impact is reduced. Energy will not be absorbed smoothly. As a result, the shock-absorbing steering column device cannot perform its intended operation, and the driver may receive an impact on the chest or head. The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a steering column device that realizes a reduction in the number of components and the like while improving the safety of a driver in a collision.

[0006]

Therefore, in order to solve the above-mentioned problems, according to the present invention, a column drive means for retreating a driver from a steering column and a collision detection means for detecting a collision of a vehicle. And electrical control means for driving the column drive means and deploying the driver seat airbag based on the detection result of the collision detection means, and the electric control means operates the column drive means. Then, a steering column device for deploying the driver's seat airbag is proposed.

In the present invention, for example, when the electric control means determines a collision of the vehicle based on the detection signal from the collision detection means, it first drives the column driving means to pull the steering column forward, and then expands the steering column. Ensure the distance between the airbag and the driver.

According to a second aspect of the present invention, in the steering column device of the first aspect, a collision energy absorbing means for absorbing a secondary collision energy of a driver at the time of a vehicle collision, and the second collision energy absorbing means is provided by the collision energy absorbing means. An energy absorption amount adjusting means for changing the absorption amount of the next collision energy is proposed.

According to the present invention, for example, when the vehicle collides at such a speed that the airbag does not deploy, the electric control means controls the steering column so that the steering column is easily collapsed. The absorption amount of the next collision energy is reduced.

According to a third aspect of the present invention, in the steering column device according to the first or second aspect, the electric control means activates the seat belt pretensioner for a driver's seat after activating the column drive means. Suggest something.

According to the present invention, for example, after the electric control means pulls the steering column forward by the column driving means, the electric control means can deploy the driver airbag and operate the driver seat belt pretensioner with a predetermined time lag. And reliably restrain the driver to the seat when the driver's seat airbag is deployed.

[0012]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a side view showing a passenger compartment of a passenger car according to an embodiment, and reference numeral 1 in the figure denotes a steering device. The steering device 1 includes a steering column 7 attached to a vehicle body-side member 2 via a tilt bracket 3 and a lower bracket 5, an upper steering shaft 9 rotatably held in the steering column 7, and an upper steering shaft. 9 and a universal joint 1 at the lower end of the upper steering shaft 9.
The lower steering shaft 15 and the like are connected to each other via the lower steering shaft 3. In the drawing, a member indicated by reference numeral 17 is a steering pad provided at a central portion of the steering wheel 11, and accommodates an airbag, an inflator 18 for deploying the airbag, and the like. The member indicated by reference numeral 19 is a column cover, and the member indicated by reference numeral 20 is a tilt lever.

In this steering device, when the driver rotates the steering wheel 11, the rotational force is transmitted to a steering gear (not shown) via the upper steering shaft 9 and the lower steering shaft 15. The steering gear has a built-in rack-and-pinion mechanism that converts a rotational input into a linear motion, and the steering is performed by changing the steering angle of the wheel via a tie rod or the like. Various types of steering gears such as a ball screw type and a worm roller type are known in addition to the rack and pinion type.

The driver 21 sits on the driver seat 25 attached to the floor pan 23 and seats the seat belt 2.
7 restrains the seat 25. Sheet 25
Moves back and forth along a seat rail 29 fixed to the floor pan 23, and the angle of the backrest 31 can be adjusted according to the riding posture of the driver.
An ECU 37 and an impact sensor 39 for detecting a collision are provided between the dash panel 33 and the instrument panel 35, and a detection signal of the impact sensor 39 is transmitted to the ECU 37. In the case of the present embodiment, a vehicle speed sensor 34 and a seat belt sensor 36 are used in addition to the impact sensor 39 as a collision detection sensor, and these detection signals are also transmitted to the ECU 37. In FIG. 1, a member indicated by reference numeral 38 is a seat belt pretensioner, which operates with gas generated by a built-in gas generator 40 and winds up the seat belt 27 with a predetermined tension. The inflator 18 for deploying the airbag and the gas generator 40 for the seat belt pretensioner 38 are both ECUs.
37.

FIG. 2 is a side view of the steering column 7, and FIG. 3 is an enlarged view of a portion A in FIG. As shown in these figures, the steering column 7 has an outer column 41 and an inner column 43 both made of steel pipe, and a distance bracket 45 welded to the outer column 41.
, A column retracting mechanism 47 and a variable collision energy absorbing mechanism 49 as main components. In the case of the present embodiment, the distance bracket 45 is held by the tilt bracket 3 and detaches forward from the vehicle body side member 2 together with the tilt bracket 3 when a predetermined forward load is applied. In FIG. 2, a member denoted by reference numeral 50 is a capsule made of an aluminum alloy or the like, and is fixed to the tilt bracket 3 with a predetermined fastening force by resin injection. The member denoted by reference numeral 51 is a rubber bush interposed between the lower bracket 5 and the inner column 43, and absorbs the swing of the steering column 7 at the time of tilt.

As shown in FIG. 2, the column retraction mechanism 47
A gas cylinder 53 fitted and fixed to the lower bracket 5, a piston 55 held in the gas cylinder 53 so as to be able to be urged, a rod 57 having both ends connected to the piston 55 and the distance bracket 45, And a gas generator 59 mounted on the rear upper surface of the cylinder 53. The gas generator 59
The ECU 37 is connected to the ECU 37 and ignites by the ignition current from the ECU 37 to discharge gas from the piston 5 in the gas cylinder 53.
5 Feed to the rear. The rear end of the rod 57 is hook 58
And is engaged with a locking pin 60 fixed to the distance bracket 45.

FIG. 3, FIG. 4 (viewed in the direction of arrow B in FIG. 3), FIG.
As shown in (C-C cross-sectional view in FIG. 3), the variable collision energy absorbing mechanism 49 includes a first metal ball holding cylinder 61 interposed between the outer column 41 and the inner column 43,
The main constituent members are a second metal ball holding tube 63 disposed in front of the first metal ball holding tube 61 and a holding tube locking device 65 for locking the second metal ball holding tube 63.

The first metal ball holding cylinder 61 and the second metal ball holding cylinder 63 are both made of a synthetic resin or a sintered oil-impregnated alloy, and rotatably hold steel balls 67 and 69, respectively. In the case of the present embodiment, the first metal ball holding cylinder 61 and the second metal ball holding cylinder 63 are connected with a predetermined engaging force by engaging claws (not shown), but are connected by a resin shear pin or the like. Is also good.

The outer diameters of the steel balls 67 and 69 are set to be larger than the gap between the outer column 41 and the inner column 43 by a predetermined amount, and when the outer column 41 and the inner column 43 relatively move in the axial direction. Plastic grooves are formed on the inner and outer peripheral surfaces of both columns 41 and 43. The steel ball 67 on the first metal ball holding cylinder 61 side and the steel ball 69 on the second metal ball holding cylinder 63 side
Is different in angular phase in the rotation direction.

The holding cylinder locking device 65 includes the outer column 41
A housing 71 made of aluminum alloy, synthetic resin, steel or the like fixed to the outer column 41, a housing 71 made of aluminum alloy, synthetic resin, steel or the like fixed to the outer column 41, and a cylinder 73 in the housing 71
Piston 75 slidably held in the housing 7 and the housing 7
1 comprises a gas generator 79 and the like which is screwed into the rear part and ignition-controlled by the ECU 37. A through-hole 81 is formed in the second metal ball holding cylinder 63, and a locking pin 83 projecting from the center of the piston 75 is fitted into the through-hole 81 in the locked state of FIG. 4. . In FIG.
Indicates a gas passage formed in the housing 71,
The gas generator 79 communicates with the front of the piston 75.

The housing 71 has a pair of movement preventing pins 91 whose cone-shaped tips engage with the rear surface of the piston 75.
And a coil spring 93 that urges the movement preventing pin 91 toward the piston 75, and is held in a locked state so that the piston 75 is not accidentally moved. In the figure, a member indicated by reference numeral 95 is a plug for holding the coil spring 93, and a member indicated by reference numeral 97 is a plug for preventing the piston 75 from falling off, and both are press-fitted and fixed to the housing 71.

In the present embodiment, a positioning projection 99 is formed on the housing 71, and the positioning projection 9
By fitting the inside end of 9 into a locking hole (not shown) formed in outer column 41, positioning of housing 71 with respect to outer column 41 and prevention of rotation are performed. When the housing 71 is fixed to the outer column 41, a method may be employed in which the housing 71 is formed into a cylindrical shape whose inner diameter is smaller than the outer diameter of the outer column 41 by a predetermined amount, and then press-fitted into the outer column 41.

Hereinafter, the operation of the embodiment will be described. When the vehicle starts running, the ECU 37 detects a collision at a predetermined control interval based on input signals from the impact sensor 39, the vehicle speed sensor 34, and the seat belt sensor 36. And, the relative speed of the car is higher than the predetermined value (medium speed)
When the ECU 37 determines that the vehicle has collided with another vehicle or an obstacle on the road, the ECU 37 first supplies an ignition current to the gas generator 59 of the column retracting mechanism 47 and the gas generator 79 of the variable collision energy absorbing mechanism 49.

Gas generator 5 of column retraction mechanism 47
9 instantaneously generates a large amount of gas when the ignition current is supplied, and advances the piston 55 in the gas cylinder 53 as shown in FIG. Thus, the distance bracket 45 connected to the piston 55 via the rod 57
Is also pulled forward, the tilt bracket 3 separates from the capsule 50 (that is, the vehicle body member 2) forward, and the outer column 41 is pulled forward by a predetermined amount together with the steering wheel 11.

The gas generator 79 of the variable collision energy absorbing mechanism 49 also generates a large amount of gas instantaneously when the ignition current is supplied, and the gas flows through the gas passage 85 into the front surface of the piston 75. I do. Then, as shown in FIG. 7, the piston 75 pushes back the movement preventing pin 91 urged by the coil spring 93 and immediately retreats, and the locking pin 83 of the piston 75 and the second metal ball holding cylinder 63 Is disengaged from the through-hole 81 and is released.

The ECU 37 supplies an ignition current to the gas generator 59 of the column retracting mechanism 47 and the gas generator 79 of the variable collision energy absorbing mechanism 49, and after a predetermined time (for example, several milliseconds) has elapsed, An ignition current is supplied to the bag inflator 18 and the gas generator 40 of the seat belt pretensioner 38.
Then, at the same time when the airbag is deployed and inflated, the driver 21 is securely restrained by the seat 31 by the seatbelt 27 wound by the seatbelt pretensioner 38. At this time, since the outer column 41 is pulled forward, the steering wheel 11 and the driver 21
Is sufficient (30 cm or more), the rear surface of the airbag does not hit the face or chest of the driver 21 hardly, and even a spectacle wearer or the like is liable to suffer unexpected damage from the airbag. It is gone.

After the airbag is contracted, the driver 21 makes a secondary collision with the steering wheel 11 due to its inertia, and the steering wheel 11 is pressed forward, and as shown in FIG. 8, after the outer column 41 is retracted. When the inner column 43 enters the outer column 41 by the extra stroke, the steering column 7 starts to collapse. At this time, since the first metal ball holding cylinder 61 and the second metal ball holding cylinder 63 of the variable collision energy absorbing mechanism 49 are connected, as shown in FIG. Integrally move forward between the outer column 41 and the inner column 43 with a movement amount of a half of the movement amount of the inner column 43. Accordingly, plastic grooves formed by the steel balls 67 on the first metal ball holding cylinder 61 side and the steel balls 69 on the second metal ball holding cylinder 63 side are formed on the inner peripheral surface of the outer column 41 and the outer peripheral surface of the inner column 43. Are formed, and a relatively large impact energy absorption is realized. The solid line in FIG. 10 is at this time (at the time of a large collapse load).
3 shows the test results.

On the other hand, if it is determined that the vehicle has collided with another vehicle or an obstacle on the road at a relative speed (low speed) lower than a predetermined value, the ECU 37 deploys the airbag and drives the variable collision energy absorbing mechanism 49. Column retraction mechanism 4
7 and the seat belt pretensioner 38 are not operated.
When the driver 21 makes a secondary collision with the steering wheel 11 in this state, the steering column 7 starts to collapse after the outer column 41 separates from the vehicle body side member 2. At this time, since the second metal ball holding cylinder 63 is locked by the piston 75, as shown in FIG.
The metal ball holding cylinder 61 cannot be retracted (the two metal ball holding cylinders 61 and 63 are separated by overcoming the engaging force of the locking claw or the like), and the plastic groove formed by the steel ball 67 on the first metal ball holding cylinder 61 side. Only is formed, and the amount of impact energy absorbed is relatively small. As a result, even in the case of a slight collision, the steering column 7 is smoothly collapsed, and the impact on the chest and head of the driver 21 is reduced. The broken line in FIG. 10 indicates the test result at this time (at the time of a small collapse load), and it is understood that the small collapse load is significantly smaller than the large collapse load.

Next, as a modification of the above-described embodiment, a case where a two-stage deployable airbag is adopted will be described. In the airbag according to the present modification, the volume at the time of inflation is different between the fully deployed setting and the small deployed setting.
Is small and the distance from the steering wheel 11 is 25.4
cm is set to a small expansion setting. When it is determined that the vehicle has collided with another vehicle or an obstacle on the road at a medium or high speed when the airbag is set to the small deployment, the ECU 37 determines whether the gas generator 79 of the variable collision energy absorbing mechanism 49 has No ignition current is supplied to the gas generator 59 of the column retraction mechanism 47, the inflator 18 for deploying the airbag, and the gas generator 40 of the seat belt pretensioner 38 at the same time. The distance between the driver 21 and the steering wheel 11 can be detected by a known infrared distance measuring sensor or the like.

Then, the steering column 7 absorbs a small amount of impact energy (that is, collapses relatively easily). Therefore, when the column retracting mechanism 47 is operated, the steering column 7 is retracted more forward than at the time of the full extension setting, and the driving is performed. The distance between the driver 21 and the steering wheel 11 is sufficiently ensured. In addition, since the absorption amount of the impact energy is small, the relatively light driver
Even in the case of a secondary collision, the steering column 7 smoothly collapses to absorb the collision energy, and the impact received on the chest and head of the driver 21 is reduced.

The description of the specific embodiment has been completed.
The aspects of the present invention are not limited to the above embodiment.
For example, in the above embodiment, the deployment of the airbag and the driving of the seatbelt pretensioner are performed at the same time, but after the outer column is retracted and the seatbelt pretensioner is driven, the airbag is deployed. You may. In the above embodiment, both the column retracting mechanism and the collision energy absorbing mechanism are provided. However, only the column retracting mechanism may be provided. In addition to the overall structure of the steering device, the specific structures of the column retracting mechanism and the collision energy absorbing mechanism,
Modifications can be made as appropriate without departing from the spirit of the present invention.

[0032]

As described above, according to the steering column device of the present invention, the column driving means for retracting the steering column for the driver, the collision detecting means for detecting the collision of the vehicle, An electric control unit that drives the column driving unit and deploys the driver seat airbag based on the detection result of the collision detection unit, and the electric control unit operates the column driving unit after the column control unit is operated. Since the driver's seat airbag is deployed, the steering column is retracted when the airbag is deployed, so that the rear surface of the airbag does not strike the driver's face or chest and the safety in the event of a collision is eliminated. In addition to the above, it is possible to share sensors and ECUs for collision detection, thereby reducing the cost of the apparatus.

[Brief description of the drawings]

FIG. 1 is a side view showing a passenger compartment of a passenger car according to an embodiment.

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

FIG. 3 is an enlarged view of a portion A in FIG. 2;

FIG. 4 is a view as seen from the arrow B in FIG. 3;

FIG. 5 is a sectional view taken along line CC in FIG.

FIG. 6 is an explanatory view showing the operation of the column retracting mechanism.

FIG. 7 is an explanatory diagram showing the operation of the collision energy absorbing mechanism.

FIG. 8 is an explanatory diagram showing the operation of the collision energy absorbing mechanism.

FIG. 9 is an explanatory view showing the operation of the collision energy absorbing mechanism.

FIG. 10 is a graph showing a relationship between a movement stroke of an outer column and a collapse load.

FIG. 11 is an explanatory diagram showing the operation of the collision energy absorbing mechanism.

[Explanation of symbols]

1 Steering device 3 Tilt bracket 5 Lower bracket 7 Steering column 11 Steering wheel 18 Inflator (for airbag) 21 Driver 25 Seat 34 Vehicle speed sensor 36 ‥ Seat belt sensor 37 ‥‥ ECU 38 ‥‥ Seat belt pretensioner 39 ‥‥ Impact sensor 40 ‥‥ Gas generator (for seat belt pretensioner) 41 ‥‥ Outer column 43 ‥‥ Inner column 45 ‥‥ Distance bracket 47 ‥‥ Column driving mechanism 49 Variable impact energy absorbing mechanism 53 Gas cylinder 55 Piston 57 Rod 59 Gas generator (for column driving mechanism) 61 First metal ball holding cylinder 63 Second Metal ball holding cylinder 65 ‥‥ Holding cylinder locking device 67, 69 ‥ Steel ball 71 ‥‥ housing 73 ‥‥ cylinder 75 ‥‥ piston 79 ‥‥ gas generator (for variable impact energy absorbing mechanism) 81 ‥‥ through hole 83 ‥‥ locking projection

Claims (3)

[Claims] 1. A column driving means for retracting a steering column with respect to a driver; a collision detecting means for detecting a collision of a vehicle; and a driving and driving of the column driving means based on a detection result of the collision detecting means. An electric control unit for performing deployment of a seat airbag, wherein the electric control unit deploys the driver seat airbag after operating the column driving unit. apparatus. 2. A collision energy absorbing means for absorbing a secondary collision energy of a driver at the time of a vehicle collision, and an energy absorption amount adjusting means for changing an absorption amount of the secondary collision energy by the collision energy absorbing means. The steering column device according to claim 1, further comprising: 3. The seat belt pretensioner for a driver's seat after the electric control means operates the column driving means.
The steering column device according to the above.