JPH07164985A - Active roll bar device - Google Patents

Abstract

PURPOSE:To provide an active roll bar device which is constituted to properly ensure safety of a passenger by judging the occurrence of the rapid overturn of a vehicle. CONSTITUTION:Based on a relation between an inclination angle detected by an inclination angle detecting means 5 and inclination and a tilting angular velocity detected by a tilting angular velocity detecting means 4, the turnover of a vehicle is decided. A control means 6 to effect rise of roll bars 2a and 2b through actuation of an actuator 3 is provided and the living space of a passenger is ensured.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an active roll bar device which automatically stands up when a vehicle is capsized and protects an occupant.

[0002]

2. Description of the Related Art As a conventional roll bar, a fixed type in which it is fixed in a state of standing upright behind a seat of a vehicle is mainstream, but from the viewpoint of feeling of freedom and design, it automatically stands up when the vehicle is overturned. The format is shifting to the so-called active type.

As such an active roll bar device, for example, one in which the roll bar rotates from the rear to the front and stands up (Japanese Patent Laid-Open No. 1-95956),
Further, there is known a roll bar in which the roll bar rotates laterally to stand up (Japanese Patent Laid-Open No. 3-128742).

[0004]

In the above-described conventional active roll bar device, the inclination angle of the vehicle is detected, and when the inclination angle exceeds a certain threshold value, it is determined that the vehicle is overturned, and the roll bar is automatically rotated. I am trying to launch it.

However, even if it is possible to judge the slow rolling of the vehicle only by detecting the inclination angle of the vehicle as in the conventional case, it is delayed to judge the rapid rolling of the vehicle.
It was necessary to significantly improve the performance of the actuator that launches the roll bar. Further, in order to assist the judgment of the vehicle overturning, it is performed to detect the departure of the tire and the acceleration in the front-rear direction, but still it was not possible to reliably judge the overturning of the vehicle. .

The present invention has been made in view of the above-mentioned prior art, and an object of the present invention is to provide an active roll bar device capable of promptly judging the overturning of a vehicle.

[0007]

The structure of the present invention which achieves such an object is a roll bar supported so as to be able to stand up behind a seat of a vehicle, and a lock for raising the roll bar and locking the raised state. In an active roll bar device having an actuator with a mechanism,
The relationship between the inclination angle detecting means for detecting the inclination angle of the vehicle, the inclination angular velocity detecting means for detecting the inclination angular velocity of the vehicle, and the inclination angle detected by the inclination angle detecting means and the inclination angular velocity detected by the inclination angular velocity detecting means. And a control means for determining the overturning of the vehicle based on the above and operating the actuator to start up the roll bar.

[0008]

When the relationship between the vehicle inclination angle detected by the inclination angle detecting means and the vehicle inclination angular velocity detected by the inclination angular velocity detecting means satisfies a certain condition, it is determined that the vehicle has overturned and the locking mechanism. The actuator with the actuator operates to automatically start the roll bar. This secures a living space for the occupant and reduces injury to the occupant. Further, even when the inclination angle is small, when the inclination angular velocity is large, a rapid rollover of the vehicle is predicted, so that the roll bar can be automatically started up.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail below with reference to the embodiments shown in the drawings. 1 to 3 show an embodiment of the present invention. As shown in the figure, behind the seat of the vehicle 1, active roll bars 2a and 2b are provided on the left and right respectively. These active roll bars 2a, 2
1 is normally stored in the vehicle body as indicated by the broken line in FIG. 1, but when the vehicle is overturned, it is in a posture in which the vehicle is swung laterally up to the state shown by the solid line in FIG. .

That is, the active roll bars 2a, 2b
Is a round pipe that is bent inward of the vehicle, and one end of the circular pipe is pivotally attached to the vehicle body side at the rear of the seat of the vehicle 1 about the longitudinal axis of the vehicle. An expandable actuator 3 is interposed between the active roll bars 2a and 2b and the vehicle body side. As shown in FIGS. 3A and 3B, the actuator 3 is provided with a pre-compressed spring 3a and a trigger mechanism 3b for releasing the pre-compression of the spring 3a, and further extended. A one-way lock 3c for holding the state is provided.

For this reason, the actuator 3 is normally in a contracted state as shown in FIG. 3A, but when the trigger mechanism 3b is operated, the spring 3 is moved as shown in FIG. 3B.
Due to the restoring force of a, will be instantly extended. Incidentally, the actuator 3 is not limited to such a structure, and various types shown in Japanese Patent Laid-Open No. 1-95956 can be used, for example.

Therefore, in a normal state, since the actuator 3 is contracted, the active roll bars 2a and 2b are in the posture stored in the vehicle body as shown by the broken line in the figure, but it is determined that the vehicle is overturned. Then, the trigger mechanism 3b
Is activated and the spring 3a is extended by the restoring force, and the active roll bars 2a and 2b are rotated laterally to be in a posture of rising and unfolding, as shown by solid lines in the figure. In this state, the actuator 3 is locked in the contracting direction by the one-way lock 3c, so that the roll bars 2a and 2b are maintained in the expanded state while withstanding the load during the overturning.

FIG. 4 shows the control system of the above embodiment. As shown in the figure, this control system includes an angular velocity sensor 4 which is a lean angular velocity detecting means, a lean angle sensor 5 which is a lean angle detecting means, a signal processing section 6 and a power source section 7, and determines whether the vehicle is overthrown. Then, the trigger mechanism 3b is energized to deploy the roll bars 2a and 2b. The angular velocity sensor 4 measures the inclination angular velocity of the vehicle body, and for example, a vibration gyro or a piezo element can be used. In this embodiment, the roll angle, which is the lateral inclination angle of the vehicle, is measured.
However, the present invention is not limited to this, and the pitch angle, which is the inclination angle of the vehicle in the front-rear direction, may be measured.

The inclination angle sensor 5 measures the inclination angle of the vehicle body from the horizontal, and in the present embodiment, it measures the roll angle which is the inclination angle of the vehicle in the lateral direction. However, the present invention is not limited to this, and the pitch angle, which is the inclination angle of the vehicle in the front-rear direction, may be measured. The power supply unit 7 supplies operating power for the above-mentioned units and the active roll bar.

The signal processing unit 6 determines the rollover of the vehicle according to the flowchart shown in FIG.
A procedure for determining the vehicle rollover in the signal processing unit 6 will be described with reference to FIG.

First, the initial vehicle body inclination angle θ ₀ is measured. The initial vehicle body inclination angle θ ₀ is the inclination angle θ (de) detected by the inclination angle sensor 5 after the ignition switch is turned on.
g) is measured a predetermined number of times at predetermined intervals and the values are averaged. The reason for averaging in this way is that the ignition switch may be turned on when the vehicle body is tilted. Next, by the angular velocity sensor 4, the angular velocity ω
Measure (deg / sec). If the angular velocity ω is a function of time, the integral of the angular velocity and the initial vehicle body inclination angle θ ₀
From this, the vehicle body inclination angle θ is obtained as shown in the following equation (1).

[0017]

[Equation 1]

Here, the angular velocity ω is set to a predetermined time T (se
Sampling is performed in step c), and the values are sequentially added as shown in the following equation (2). θ ′ = ω · T + θ (2) where θ ′ is the current vehicle body tilt angle, T is the sampling period of the angular velocity ω, and θ is one step before (past time T)
Is the vehicle body inclination angle.

Subsequently, it is determined from the relationship between the angular velocity ω and the vehicle body inclination angle θ whether or not the rollover occurs. Whether or not the rollover occurs is determined by the balance between the angular velocity ω and the vehicle body inclination angle θ, but the rollover is more likely to be determined as the angular velocity ω and the vehicle body inclination angle θ increase.

In the present embodiment, rollover is determined when the region satisfies the following expression (3) or (4), that is, the region shown by the broken line in FIG. θ + A × ω> 90 (3) θ + A × ω <−90 (4) where A is a constant determined by the vehicle type. When the vehicle inclination angle θ is within a relatively small predetermined range (within ± θ _s ), rollover is not determined even if the angular velocity ω is large. In addition, the vehicle body inclination angle θ is a relatively large predetermined value or a relatively small predetermined value or less (θ _r or more and −θ _r or less).
When, the rollover is determined regardless of the value of the angular velocity ω.

This is because in the region where the vehicle body inclination angle θ is close to 0, that is, when the vehicle body angle is almost horizontal, rollover is generally not considered. Further, if the vehicle body inclination angle θ is extremely large or small, it is inevitable that the vehicle body will roll over due to the position of the center of gravity of the vehicle. However, the rollover determination map shown in FIG. 6 shows an example of the determination and is not limited to this, and may be appropriately rewritten and used according to the type, purpose, environment, etc. of the vehicle.

Further, when it is determined that the rollover has occurred, a trigger current is supplied from the power supply section 7 to the trigger mechanism 3b. Trigger mechanism 3b supplied with trigger current
Activates the actuator 3 to cause the roll bars 2a, 2
b is in the expanded state.

On the other hand, when it is determined that the rollover has not occurred, the tilt angle θ _m is measured by the tilt angle sensor 5 on condition that the time t = n (sec). Subsequently, the inclination angle θ _m and the constant value θ _th are compared as shown in the following equation. θ _m ≦ θ _th (5) However, the constant value θ _th is preferably a relatively small value that is rewritable and does not roll over.

When the inclination angle θ _m is a constant value θ _th or less and the vehicle body inclination angle θ is 0 or more, a small angle θ _d is subtracted from the vehicle body inclination angle θ as shown in the following equation (6). On the contrary, when the vehicle body inclination angle θ exceeds 0, the minute angle θ _d is added to the vehicle body inclination angle θ as shown in the following expression (7). θ = θ−θ _d (6) θ = θ + θ _d (7)

That is, in this embodiment, when it is determined that the rollover is not performed, a fixed time has elapsed, and when the tilt angle θ _m measured by the tilt angle sensor is equal to or less than the constant value θ _th , the small angle θ is set. It is corrected by adding or subtracting _{d so} that the absolute value of the vehicle body inclination angle θ converges to zero. By correcting in this way, the error of the angular velocity ω measured by the angular velocity sensor 4 does not accumulate, which prevents the divergence of the vehicle body inclination angle θ.

As described above, the active roll bar device of this embodiment takes into consideration not only the tilt angle θ _m measured by the tilt angle sensor 5 but also the angular velocity ω measured by the angular velocity sensor 4 in consideration of the rollover. Therefore, for example, even when the angular velocity ω is large and rapid rollover of the vehicle is expected to occur, the rollover of the vehicle is quickly detected, the actuator 3 is operated, and the roll bar 2a,
2b can be expanded.

Therefore, the occupant's living space can be surely secured even when the vehicle rolls over, and the occupant's injury can be prevented. Further, in this embodiment, the roll bars 2a and 2b are housed in the rear of the rear seat, so that four passengers can ride in the vehicle. Particularly, since the roll bars 2a and 2b are stored by being rotated in the lateral direction, the dimension in the front-rear direction can be shortened. Further, since the roll bars 2a and 2b are left and right independent type, there is also an advantage that the weight is reduced as compared with the integrated type.

It is even more effective if other occupant protection devices, such as seat belt tensioners, are also operated simultaneously with the active roll bar device.

[0029]

As described above in detail with reference to the embodiments, the present invention determines the overturning of the vehicle on the basis of the angular velocity detected by the inclination angular velocity detecting means, so that a sudden rollover of the vehicle can be performed. It is possible to make an early prediction, reliably secure a living space for the occupant, and prevent injuries to the occupant in advance.

[Brief description of drawings]

FIG. 1 is an external view of an active roll bar device according to an embodiment of the present invention.

FIG. 2 is a front view of the roll bar in an expanded state according to an embodiment of the present invention.

3A and 3B are explanatory views showing a stretched state and an extended state of the actuator.

FIG. 4 is a control system diagram according to an embodiment of the present invention.

FIG. 5 is a flowchart showing a rollover detection algorithm.

FIG. 6 is a rollover determination map.

[Explanation of symbols]

 1 Vehicle 2a, 2b Roll bar 3 Actuator 3a Spring 3b Trigger mechanism 3c One-way lock 4 Angular velocity sensor 5 Inclination angle sensor 6 Signal processing unit 7 Power supply unit

Claims (1)

[Claims] 1. An active roll bar device having a roll bar supported rearwardly of a seat of a vehicle so as to be able to stand up, and an actuator with a lock mechanism for raising the roll bar and locking the state in which the roll bar is raised up. Based on the relationship between the inclination angle detecting means for detecting the angle, the inclination angle detecting means for detecting the inclination angular velocity of the vehicle, and the inclination angle detected by the inclination angle detecting means and the inclination angular velocity detected by the inclination angular velocity detecting means. An active roll bar device, comprising: a control unit that determines whether the vehicle is overturned and operates the actuator to start the roll bar.