JPH08324379A - Side impact detecting device for vehicle - Google Patents

Abstract

PURPOSE: To prevent wrong detection in the case of detecting a side impact from the sudden pressure fluctuation of a space in a side door. CONSTITUTION: In the case of sudden air pressure rise being detected by an air pressure sensor 11 disposed in the door internal space 12 of a vehicle, an air bag expansion control device (side impact judging means) 13 judges a side impact and outputs an ignition signal to an inflator to expand an air bag. In the case of the air pressure sensor 11 detecting negative pressure lower than the specified value, the air bag expansion control device 13 measures the negative pressure duration and sets the side impact judgement inhibiting duration to 3.Δt time, for instance, according to the measured negative pressure duration Δt, and does not judge a side impact even if sudden air pressure rise caused by closing a door hard is detected before the lapse of the inhibiting duration 3.Δt.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a side collision detection device which detects a side collision of a vehicle such as an automobile and outputs a signal for activating a vehicle side protection occupant protection device or the like. .

[0002]

2. Description of the Related Art For example, as one of methods for detecting a side collision in which another vehicle collides with a side surface of a running vehicle, there is a method of detecting a side pressure collision in a space inside a side door having a substantially closed structure. is there.

FIGS. 8 and 9 show a conventional side collision detection device using the pressure sensor 1 described in German Published Patent Specification DE 4322488, in which the side surface of the vehicle is used. The pressure sensor 1 is fixed in the inner space of the door between the door outer panel (not shown) of the door 2 and the door inner panel 2a, and is fixed to the inner surface of the door inner panel 2a with the pressure introduction port 1a thereof facing the door outer panel. Is provided.

The pressure sensor 1 is a piezo-resistive pressure detector, and as shown in FIG. 9, the pressure inlet 1a is mounted substantially at the center of the inner surface of the door inner panel 2a so as to be oriented in a substantially horizontal direction. When the side collision accident occurs, the door outer panel is deformed inwardly of the vehicle body, so that the shock and vibration generated at this deformed portion are propagated through the air in the entire door inner space, and the pressure fluctuations caused by the shock and vibration are generated by the pressure sensor 1. To be detected. A side collision is determined based on the shocking pressure increase, and an operation signal or the like is sent to an occupant protection device such as an airbag device.

[0005]

However, in the above-described conventional side collision detection device, when the side door 2 is strongly closed, the same impact pressure increase as in a side collision may occur. This is because heavy items such as the power window regulator, door trim and armrests are attached to the door inner panel of the side door of the vehicle, so that the door inner panel swells to the inside of the vehicle due to the inertial force when the door is closed tightly. On the other hand, the door outer panel is formed of one thin steel plate and has an arc-shaped cross section, and is hardly deformed toward the vehicle interior side even when the door is strongly closed. Therefore, when the door is closed tightly, the volume of the space between the door inner panel and the door outer panel once increases and sucks air into the space, and when the inflated door inner panel returns to the original volume, As the air pressure decreases, the air in the space is compressed and the internal pressure rises.

Also, when a high-pressure air blow is blown into the door for cleaning the vehicle, the pressure in the door space also rises.

As described above, the internal pressure of the side door 2 of the vehicle is generated not only by the deformation due to the side collision but also during the strong closing or the cleaning, so that the pressure detected by the pressure sensor 1 becomes a predetermined value or more. In a device that determines that a side collision is due to a rise, there is a possibility that a pressure increase due to a strong closing of a door may be erroneously determined as a side collision.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a side collision detection device for a vehicle, which can detect a side collision with high accuracy without misjudging when a collision does not occur.

[0009]

[Means for Solving the Problems] When a sudden pressure increase occurs in the interior space of a door, the volume of the interior space of the door having a substantially closed structure is reduced, and the amount of air in the interior of the door due to inflow of air. Is considered to have increased.
Here, pay attention to the fact that the door panel is deformed during a side collision and the internal pressure rises due to this deformation, whereas in a non-collision, it becomes a negative pressure before the door internal pressure rises. The pressure rise after the occurrence is due to non-collision, and can be clearly distinguished from the pressure rise due to side collision without negative pressure generation.

Therefore, according to the present invention, as means for solving the above-mentioned problems, a side collision is determined when the pressure in the door inner space detected by the air pressure sensor arranged in the side door is higher than a predetermined value. In the vehicle side collision detection device, the negative pressure detection means for detecting the negative pressure in the door inner space, and the side collision is temporarily judged when the negative pressure detection means detects a negative pressure of a predetermined value or less. It is characterized in that it comprises a determination prohibition means for prohibiting.

Further, based on the negative pressure time measuring means for measuring the duration of the negative pressure state in the interior space of the door, and the negative pressure time measured by the negative pressure time measuring means, the judgment prohibiting means prohibits the judgment. The configuration may further include determination prohibition time setting means for setting the duration of the state.

[0012]

Therefore, according to the present invention, the negative pressure detecting means for detecting the generation of the negative pressure in the inner space of the door and the side collision judgment are temporarily performed when the negative pressure detecting means detects the negative pressure below a predetermined value. Since a side-collision detection signal is provided immediately after the side-collision, a rise in internal pressure in the door space is detected without negative pressure. Is output.

On the other hand, when no negative pressure is detected by the negative pressure detecting means during a non-collision, the determination prohibiting means operates for a certain period of time thereafter. Even if a high pressure is detected, the side collision is not judged.

Further, the duration of the negative pressure generated in the interior space of the door is measured by the negative pressure time measuring means, and the duration of the determination prohibited state by the determination inhibiting means is determined based on the measured negative pressure time. If the time is set by the time setting means, the duration of the determination prohibited state can be set to the necessary minimum, so that the range in which the side collision can be detected is expanded.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment in which the vehicle side collision detection device of the present invention is applied to the collision determination means of a side collision airbag device will be described below with reference to FIGS.

The side door 12 of an automobile is formed in a hollow cross section by a door outer panel 12a outside the vehicle body (left side in FIG. 1) and a door inner panel 12b inside the vehicle, as shown in FIG. Door space 12
c is an air pressure sensor 11 capable of measuring positive pressure and negative pressure.
However, it is fixed to approximately the center of the inner surface of the door inner panel 12b so that the air pressure in the door inner space 12c can be measured.

More specifically, the air pressure sensor 11 is a semiconductor pressure sensor, in which a part of an elastic body made of single crystal silicon is formed in a thin plate shape, and diffusion piezoresistors are arranged at four positions on the surface thereof. The pressure introducing port 11 is housed in the container and is perpendicular to the silicon thin plate portion.
a is formed. And as shown in FIG.
The pressure introducing port 11a is provided with a communicating portion so that the pressure fluctuation of the door inner space 12c can be introduced, and then the pressure introducing port 11 is attached downward to prevent intrusion of rainwater, muddy water, dust and the like. Two cover members 11b and 11c
Enclose the lower and lateral sides of the pressure introducing port 11a with
Prevents the air blow from blowing directly.

The air pressure sensor 11 is connected to an airbag deployment control unit (ECU) 13. The signal input from the air pressure sensor 11 is processed to determine a side collision, and when the side collision is determined, an inflator ignition signal is output to the airbag module 14. The airbag module 14 is configured by assembling an inflator and an airbag. Further, in FIG. 1, reference numeral 15 is a door window glass, and in FIG. 4, reference numeral 16 is a side sill.

Here, the airbag deployment control device 13 is
The ignition signal is not output only when the pressure detected by the air pressure sensor 11 is equal to or higher than a predetermined value, and the predetermined negative pressure is not generated immediately before the increase in the pressure. It is configured. That is,
Judgment prohibition control for preventing an erroneous judgment of a side collision is performed. The control routine will be described. As shown in FIG. 3, when the control is started, first, it is lower than the first negative pressure set value Pm1. When the negative pressure detecting means for detecting the pressure P detects a pressure P lower than the first negative pressure set value Pm1, the process proceeds to step 2, and the timer of the negative pressure time measuring means is started, and then step 3 Proceed to.

In step 3, the negative pressure detecting means for detecting the pressure P lower than the second negative pressure setting value Pm2 lower than the first negative pressure setting value Pm1 is the second negative pressure setting value. It is judged whether or not the pressure P lower than Pm2 is detected, and if not detected, the routine proceeds to step 4, where it is judged whether or not the measured value of the timer is 50 msec or more. If 50 msec or more has passed in step 4, the pressure fluctuation is gentle and therefore there is no possibility of being erroneously determined to be a side collision, so the timer is canceled in step 5 and the measurement of negative pressure time is stopped. To be done.

In step 4, the elapsed time is 50
If it is less than msec, return to step 3. And 50ms
If a pressure P lower than the second negative pressure set value Pm2 is detected before ec has elapsed, the routine proceeds to step 6.

In step 6, the pressure P which is lower than the second negative pressure set value Pm2 and then rises again and becomes higher than the first negative pressure set value Pm1 is detected, and this pressure P is detected. If detected, the timer is stopped in step 7 and the measurement of the negative pressure time is completed.

Next, the measured duration Δt of the negative pressure state
After the mask mode time Tα for prohibiting the side collision judgment is set by the judgment prohibition time setting means in step 8, the mask mode in the judgment prohibition state is entered in step 9.

Then, in step 10, the mask mode time T
It is determined whether or not α has not elapsed, the mask mode is maintained while α has not elapsed, and when the mask mode time Tα has elapsed, the mask mode is automatically switched to the normal mode.
Return to 1.

Here, the mask mode time Tα will be described. The mask mode is a mode in which a collision signal is not output even when the pressure P in the door inner space 12c rises, and therefore its duration is preferably as short as possible within a range that prevents erroneous determination. Therefore, the mask mode time Tα may be set according to the fluctuation of the pressure P due to a reason other than the collision.

Therefore, first, when the door is closed tightly and in the door inner space 1
When the air pressure sensor 11 arranged in the door inner space 12c measures the pressure fluctuation of the door inner space 12c at the time of blowing air into the 2c, as shown in FIG. 6, when the door is strongly closed (FIG. 4B). Immediately after (state), the pressure drops sharply. This is because when the side door 12 is strongly closed as shown in FIG. 4 (A), the door inner panel 12b to which a power window regulator or the like is attached immediately after the side door 12 is strongly closed as shown in FIG. 4 (B). It is considered that this is caused by such a deformation in which the door inner panel 12b swells to the passenger compartment side and then the door inner panel 12b returns to the original state from the swelled state as shown in FIG.

Further, the pressure fluctuation in the door inner space 12 due to the air blown from the working hole 12d at the time of cleaning is
Since the cover members 11b and 11c are provided so that the air blow is not directly blown into the pressure introduction port 11a of the air pressure sensor 11, as shown in FIG. , When the air is blown in the direction of the arrow Y (obliquely downward),
No sharp pressure fluctuation was detected by No. 1.

When blown in the direction of arrow Z (obliquely upward) shown in FIG. 5B, the cover member 11b,
Since high-speed air flows near the slits between 11c, the air around the pressure introducing port 11a is sucked and a negative pressure is detected. The pressure fluctuation in the door inner space 12c at this time is as shown in FIG. In addition, a negative pressure was generated while the air blow was continuously blown, and when the air blow was not blown, a pressure increase (positive pressure) was observed due to the inflow of air to make up for the negative pressure.

From the above, it has been found that there is a certain law in the pressure fluctuations that occur depending on the degree to which the door is strongly closed when the door is strongly closed. That is, after a rapid pressure decrease due to the strong closing of the door, a rapid pressure increase always occurs, and the pressure fluctuation in such a case ends in a short time. Similarly, after a relatively gradual decrease in pressure, a gradual increase in pressure also occurred, and the pressure fluctuation in such a case took a slightly longer time to end. Therefore, the time required for the pressure to rise and to end when the door is closed or blown with air is proportional to the duration of the negative pressure state that occurred before this pressure rise. Also in this case, it was about 2 to 3 times the duration of the negative pressure state (slightly different depending on the shape of the door, the mounting position of the air pressure sensor 11, etc.).

Therefore, as shown in FIG. 2, when the air pressure sensor 11 detects a negative pressure lower than the predetermined value Pm1, a timer is started to measure the duration Δt of this negative pressure state, and this measurement is performed. A side collision determination inhibition time (= mask mode time Tα) is obtained based on the duration Δt. As an example, the mask mode time Tα is 3 · Δt, which is three times the duration Δt.

Next, the operation of the vehicle side collision detection system of this embodiment constructed as described above will be described with reference to FIGS.

When another vehicle collides with the side door 12 on the side of the vehicle, a door outer panel 12a of the side door 12 is provided.
Is crushed and deformed in a direction of approaching the door inner panel 12b, and the volume of the interior space 12c of the door decreases and the atmospheric pressure sharply rises. The sudden pressure increase in the door inner space 12c is detected by the air pressure sensor 11, and the detected value is sent to the airbag deployment control device 13.

In the airbag deployment control device 13,
At the same time when the ignition key is turned on, the side collision determination program and the side collision erroneous determination prevention program (see Fig. 3) have started together. If the pressure is not detected, it is immediately determined to be a side collision, an ignition signal is transmitted from the airbag deployment control device 13 to the inflator of the airbag module 14, and the gas generating agent in the inflator is ignited. Then, the gas generated by the inflator is filled and the airbag of the airbag module 14 inflates and deploys in the space between the occupant and the side door 12. Therefore, the impact when the vehicle collides with the inside of the side door 12 at the time of a side collision is buffered by the airbag and the occupant is protected.

Further, for example, when the door is strongly closed, the internal pressure fluctuates due to the deformation of the door panel.
If the pressure P detected by 1 is lower than the first predetermined value Pm1, the timer is started and the measurement of the negative pressure duration Δt, which is the basic data for determining the mask mode time Tα, is started.

Since the detected pressure P fluctuates due to the deformation of the door panel and the subsequent restoration, if the pressure P falls below the second predetermined value Pm2 which is lower than the predetermined value Pm1, the subsequent pressure P The timer stops counting when the pressure becomes higher than the first predetermined value Pm1 due to the return of the pressure. In this way, the duration of the pressure of the first predetermined value Pm1 is obtained, whereby the mask mode time Tα
(3 · Δt) is set. This master mode Tα is
As described above, since the collision detection signal is not output even when the pressure P is increased to a predetermined value or more, the collision detection signal is not output even if the pressure P is detected by the compression of air by the return of the door panel.

As described above, in the above control device, the collision and the strong closing of the door are discriminated based on the state of the negative pressure preceding the increase of the pressure in the door inner space 12c, in other words,
Since the side collision is not determined only by the increase in the pressure in the door inner space 12c, the erroneous determination of the side collision is surely prevented.

The case where air is blown into the door inner space 12c during cleaning will be described. When an air blow for blowing away dust or the like is blown into the door inner space 12c, the internal pressure fluctuates, and the air pressure sensor 11 is operated. When the air flows near the pressure introducing port 11a at high speed, the air near the pressure introducing port 11a is sucked by the principle of the Venturi tube. Therefore, at this time, the air pressure sensor 11
If the pressure P detected by is less than the first predetermined value Pm1, the timer is started and the measurement of the negative pressure duration Δt, which is the basic data for determining the mask mode time Tα, is started.

Further, the detected pressure P is determined by the door internal space 1
2b is continuously detected while the air is continuously blown in,
When the pressure P falls below the second predetermined value Pm2 which is lower than the predetermined value Pm1, the timer stops counting when the pressure P becomes higher than the first predetermined value Pm1 due to the subsequent pressure recovery. In this way, the duration of the pressure of the first predetermined value Pm1 is obtained, whereby the mask mode time Tα (3 · Δt) is set. This master mode T
As in the case of the strong door closing described above, α is a mode in which the collision detection signal is not output even if the pressure P rises above a predetermined value, so the pressure P above the predetermined value is detected by the internal pressure rise at the end of the air blow. Even if it is, the collision detection signal is not output.

As described above, in the above-mentioned control device, the pressure increase due to the side collision and the pressure increase due to the air blowing are discriminated based on the negative pressure state preceding the pressure increase in the door inner space 12c. If you do, the space 12c inside the door
Since the side collision is not determined only by the increase in the pressure of 1, the erroneous determination of the side collision is reliably prevented.

As described above, in the side collision detection device of this embodiment, the air pressure sensor 11 causes the predetermined value Pm1.
When the following negative pressure is detected, the duration Δt of the negative pressure state is measured and the side collision is prevented from being erroneously determined according to the length of the measured negative pressure duration Δt. The time during which the side collision cannot be detected was shortened as much as possible by deciding the time to continue the mask mode, so that the side collision erroneous judgment at the time of non-collision can be surely prevented and the side collision can be detected. And the reliability of the side collision airbag device is improved.

[0041]

As described above, according to the vehicle side collision detection device of the present invention, even when the pressure higher than the predetermined value is detected by the air pressure sensor arranged in the side door inner space, the predetermined value is obtained before that. When a lower negative pressure is detected, the side collision judgment is temporarily prohibited to prevent erroneous judgments when there is no collision such as when the door is closed tightly, and the negative pressure has not been detected before that. In this case, a side collision is immediately detected and a side collision detection signal is output, so that safety devices such as a side collision airbag device and a pre-loader type seat belt can be accurately operated, and at the same time, when these collisions occur, It is possible to prevent unnecessary operation of the bag device and the like.

Further, it is possible to measure the duration of this negative pressure state when the negative pressure is detected, and determine the duration for continuing the side collision determination prohibition according to the length of the measured negative pressure duration. For example, it is possible to improve the safety by reducing the side collision determination prohibition state, that is, the time during which the side collision is not detected.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of a vehicle side collision detection device according to the present invention.

FIG. 2 is an explanatory diagram showing a method of determining a duration of a side collision determination inhibition state (mask mode).

FIG. 3 is a control routine for preventing side collision misjudgment.

FIG. 4 is an explanatory diagram showing a volume change of a door internal space when the door is closed tightly.

FIG. 5 is an explanatory diagram showing a blown state of an air blow into an inner space of a door.

FIG. 6 is a diagram showing pressure fluctuations in the interior space of the door when the door is strongly closed.

FIG. 7 is a diagram showing pressure fluctuations in a door inner space when an air blow is blown.

FIG. 8 is a schematic view of a side door showing a mounting position of a pressure sensor in a conventional side collision detection device.

FIG. 9 is an enlarged sectional plan view of the same pressure sensor.

[Explanation of symbols]

 11 Air Pressure Sensor 11a Pressure Inlet 12 Side Door 12b Door Inner Panel 12c Door Inner Space 12d Working Hole 13 Airbag Deployment Control Device 14 Airbag Module

Claims (2)

[Claims] 1. A vehicle side collision detection device for determining a side collision when a pressure in the door inner space detected by an air pressure sensor arranged in the side door is higher than a predetermined value. It is characterized by comprising negative pressure detection means for detecting negative pressure and determination prohibition means for temporarily inhibiting the determination of a side collision when the negative pressure detection means detects a negative pressure below a predetermined value. Side collision detection device for vehicle. 2. The negative pressure time measuring means for measuring the duration of the negative pressure state of the interior space of the door, and the negative pressure time measured by the negative pressure time measuring means based on the negative pressure time. The vehicle side collision detection device according to claim 1, further comprising a determination prohibition time setting unit that sets a duration time of the state.