JPH0747253Y2 - Shock energy absorption type steering column - Google Patents

Description

TECHNICAL FIELD The present invention relates to an impact energy absorption type steering column.

2. Description of the Related Art As a conventional impact energy absorption type steering column, for example, as shown in FIGS. 11 and 12, a lower tube 3 is inserted into an upper tube 2 to which a steering wheel 1 is attached. There is one in which steel balls 4 and 5 are interposed between the two. A slope 6 is formed on the outer periphery of the lower tube 3 and an upper tube 7 is formed.
Slopes 7 are provided on the inner periphery of the vehicle, and the occupant's chest collides with the steering wheel 1 and the upper tube 2
Is pressed against the lower tube 3, the steel balls 4,5 absorb the impact energy while cold working the upper tube 2 and the lower tube 3, and the steel balls 4,5 reach the slopes 6,7. And a larger impact energy is absorbed (this structure is disclosed in JP-A-60-35659).

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention However, in the above-mentioned conventional impact energy absorption type steering, it is possible to effectively absorb the impact energy under a wide range of load conditions from low load to high load. As a means for changing the load characteristics, it is necessary to make the energy absorbing portion stroke in the axial direction, and a large stroke is required to obtain the optimum load characteristics.

Therefore, this device does not require a large stroke,
An impact energy absorption type steering system capable of obtaining an optimum energy absorption characteristic is provided.

Means for Solving the Problems An impact energy absorption type steering column that absorbs the impact energy of an occupant during a vehicle collision.

The vehicle is provided with means for detecting the deceleration of the vehicle, means for detecting the weight of the occupant, and an energy absorbing device capable of changing the energy absorbing characteristics in accordance with the target load calculated from the detected values of these means. .

Action The deceleration of the vehicle and the weight of the occupant are detected, and the target load at which the occupant collides with the steering wheel is calculated from these detected values. Then, the energy absorption characteristics of the energy absorption device are set in real time according to this target load,
Prepare for a vehicle collision.

Embodiment Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings. First to
In FIG. 6, 8 shows an energy absorption bracket as an energy absorption device. This energy absorption bracket 8
Is welded and fixed to the upper tube 9 and the clamp 10
It is fixed by bolt 11 (with lever). S
Indicates a stopper.

On the other hand, a sliding block 12 is fixed to the vehicle body side, and a clamp 10 is attached to the sliding block 12 via a resin pin (not shown). A first solenoid 13 is fixed to the sliding block 12, and a coaxial hole (not shown) provided in the sliding block 12 and the clamp 10 by the first solenoid 13 is provided.
A metal pin can be inserted into or removed from. The operation of the first solenoid 13 is performed by an electric signal.

Further, the upper tube 9 has a bellows as an energy absorbing device at a position below the energy absorbing bracket 8.
14 are provided.

The lower tube 15 is inserted into the lower end portion of the upper tube 9 and is integrated by the caulking portion 16 (energy absorbing device). A second solenoid 17 is attached to the upper tube 9, and a metal pin (not shown) protruding by the second solenoid 17 is attached to the upper tube 9.
And coaxial hole formed in the lower tube 15 (not shown)
It can be plugged in and pulled out. The second solenoid 17 is also operated by an electric signal similarly to the first solenoid 13.

By the way, a vehicle seat is provided with a sensor for measuring the weight of an occupant. Further, a sensor for detecting the traveling speed of the vehicle is provided, and when the occupant collides with the steering wheel or the like during a vehicle collision, the deceleration α when the occupant moves forward is calculated at each moment. There is. Alternatively, the deceleration rate α may be directly measured by an acceleration sensor. It should be noted that this variable speed α is considered within the range of deceleration that humans can endure.

By the way, in the above embodiment, the case where the energy is absorbed only by the bellows 14 and the energy absorption bracket
18 and the caulking portion 16 can be set in two ways to absorb energy, and the bellows 14 is made to function when the impact load is large.

According to the structure of the above embodiment, when the metal pin of the first solenoid 13 is first removed and the metal pin of the second solenoid 17 is inserted, when the occupant collides with the steering wheel, the energy absorbing bracket 8 is clamped by the clamp 10. Since it is separated from the sliding block 12, energy is not absorbed, and energy is absorbed only by buckling of the bellows 14 (see FIG. 3).

Further, in a state where the metal pin of the first solenoid 13 is inserted and the metal pin of the second solenoid 17 is removed, when the occupant collides with the steering wheel, the lower tube 15 destroys the caulking portion 16 and the upper tube 9 The energy absorbing bracket 8 which is press-fitted into the upper tube 9 and moves together with the upper tube 9 has its lower portion fixed to the clamp 10 by the bolt 11 and its upper portion is stopped by the stopper S, so that the energy absorbing bracket 8 is cut from the end portion to absorb energy. (At this time, the bellows 14 has a high buckling load and does not deform.) Before the collision first
Fig. 2 shows the results after collision in Figs.

This will be described with reference to the flowchart of FIG.

First, m ₁ and α are input, and the target load F ₀ = m ₁ · α is calculated (steps 0, 1). Here, m ₁ is the weight of the occupant, and α is the deceleration of the occupant when the vehicle collides at that time. The reason why the target load is calculated only by m ₁ and α is that the collision load on the steering wheel is determined by the weight of the occupant and the deceleration applied to the occupant.

It should be noted that the height, age, sex, vehicle crushing characteristics, and collision direction of the occupant are not considered because they have less influence than the occupant's weight and deceleration described above.

Next, the target load F ₀ > withstand load (the load that a person can withstand) F ₁
Is determined (step 2), if YES is set to F ₀ = F ₁ (step 3), and if NO, step 4 is reached.

In step 4, F ₀ is equal to F ₂ (buckling load of bellows 14) and F 0
₃ (the resultant force of the deformation loads of the energy absorbing bracket 8 and the caulking portion 16) is compared.

If F ₀ ≧ F ₂ , the metal pin is pulled out by the first solenoid 13OFF and the metal pin is inserted by the second solenoid 17ON so that energy is absorbed only by the bellows 14 (step 5). On the other hand, when F ₂ <F ₀ ≦ F ₃ , the metal pin is inserted by the first solenoid 13ON and the metal pin is pulled out by the second solenoid 17OFF, and energy is absorbed by the deformation of the energy absorption bracket 8 and the caulking portion 16. (Step 6).

Here, F ₃ is the limit point of the load on the average occupant, and when F ₀ <F ₃ , the occupant's safety is maintained.

Then, the process returns from step 7, returns to step 0 again, and the energy absorption characteristic is optimized in response to the situation that changes moment by moment, and the stroke for energy absorption can be shortened.

The energy absorption characteristics can be set at various stages by appropriately setting the buckling load of the bellows 14 and the deformation loads of the energy absorbing bracket 8 and the caulking portion 16.

Next, FIGS. 7 to 10 show a second embodiment of the present invention.

In this embodiment, an energy absorbing device 18 described below is provided between the upper tube 9 and the lower tube 15.

The upper tube 9 is fixed to the clamp 10 by welding or the like, and the clamp 10 is fixed to the vehicle body through the sliding block 12 by bolts. An upper shaft 19 having a closed lower end is inserted into the upper tube 9, and a lower shaft 20 integrated with a resin pin P is provided on the lower end of the upper shaft 19 and sealed by an O-ring 21.

A stopper 22 made of an elastic material is fitted to the lower end of the lower shaft 20, and a fluid 23 is enclosed in the lower shaft 20 by the stopper 22. In addition, at the lower end of the upper tube 9,
A lower tube 15 is attached to surround the lower shaft 20. Inside the lower shaft 20, a support material is provided near the stopper 22.
A top 25 supported by 24 and rotating in the lower shaft 20 is attached, and a circular orifice 26 is formed on the top 25.

On the other hand, a bulged portion 27 is formed on the inner wall of the lower shaft 20, and the bulged portion 27 forms a circular opening 28 at the lower end of the lower shaft 20. Then, the bulge 27
A pinion 29 that meshes with the outer edge of the top 25 is provided inside and is rotatable by a step motor 30 so that the area of the passage 31 formed by the orifice 26 and the opening 28 can be changed. (See FIG. 8).

According to the structure of the above-described embodiment, when the occupant collides with the steering wheel during a vehicle frontal collision, the upper shaft 19 is pressed.

When the upper shaft 19 is pressed, the resin pin P is cut, the fluid 23 in the lower shaft 20 is pushed out of the passage 31, and the passage resistance absorbs impact energy without requiring many strokes.

At this time, the fluid 23 pushed out causes the stopper 22 to fall off, so that the internal pressure of the lower shaft 20 does not increase.

Therefore, when the step motor 30 rotates the top 25 through the pinion 29, the impact load that can be absorbed can be increased (decreased) when the area of the passage 31 is small (large).

As a result, as shown in FIG. 9, the area of the passage 31 is changed by the step motor 30 so as to obtain a predetermined reaction force (kg) predetermined by the weight of the occupant (kg), the speed of the vehicle, and the like. The optimum impact energy absorption characteristics can be continuously set.

Next, a description will be given with reference to the flowchart of FIG.

First, the current load F is read (step 0), and the load specified by the current passage 31 is input. Next, m ₁ and α are input to calculate the target load F ₀ = m ₁ · α, and the target load F ₀ > withstand load F ₁ is discriminated (steps 1 to 3). If YES, F ₀ = Set to F ₁ (step 4), and if NO, go to step 5.

In this step 5, F ₀ is compared with F, and when F ₀ > F, the step motor 30 is set so that the area of the passage 31 becomes smaller.
When F ₀ <F, the step motor 30 is rotated one step so that the area of the passage 31 is increased (step 7). When F ₀ = F, the step motor 30 is rotated. Do not rotate (step motor 8). And it returns to the start.

This embodiment is advantageous in that the energy absorption characteristics can be continuously changed.

Effect of the Invention As described above, according to the present invention, the target load that collides with the steering wheel of the occupant is calculated, and the energy absorption characteristic of the energy absorption device changes correspondingly. There is an effect that the optimum energy absorption characteristics can be exhibited without requiring a large stroke.

[Brief description of drawings]

FIG. 1 is a side view of the first embodiment of the present invention, FIG. 2 is a bottom view of the same main part, FIG. 3 is a side view showing the same shock absorbing state, and FIG.
FIG. 5 is a side view showing another shock absorbing state, FIG. 5 is a bottom view of a main part of FIG. 4, FIG. 6 is a flow chart, FIG. 7 is a side view of another embodiment, and FIG. FIG. 9 is an explanatory view of the vicinity of the orifice in the lower shaft, FIG. 9 is a graph, FIG. 10 is a flow chart, and FIGS. 8 ... Energy absorption bracket (energy absorption device),
14 ... Bellows (energy absorbing device), 16 ... Caulking part (energy absorbing device), 18 ... Energy absorbing device.

Front Page Continuation (72) Hideo Omura Inventor Hideo Omura 2 Takaracho, Kanagawa-ku, Yokohama, Kanagawa Nissan Motor Co., Ltd. (56) Reference JP-A-49-75981 (JP, A)

Claims (1)

[Scope of utility model registration request] 1. An impact energy absorption type steering column which absorbs impact energy of an occupant in a vehicle collision,
A means for detecting the deceleration of the vehicle, a means for detecting the weight of the occupant, and an energy absorption device capable of changing the energy absorption characteristics in accordance with the target load calculated from the detection values of these means are provided. A shock energy absorption type steering column.