JP2017170997A - Vehicle occupant protection apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the force acting on the area where a strap comes into contact with an occupant's body.SOLUTION: A vehicle occupant protection apparatus has a strap 11 configured to extend across the front of a body of an occupant sitting on a seat 5 of a vehicle, a pre-tensioner configured to retract the strap 11, a vehicle orientation sensor configured to detect either a change in the orientation of the vehicle or an operation for changing the orientation, and a controller configured to cause the pre-tensioner to start retracting the strap 11 prior to a collision or when a collision occurs. After starting retracting the strap 11, the controller temporarily stops or eases the retraction of the strap 11 in accordance with the change in the orientation of the vehicle.SELECTED DRAWING: Figure 7

Description

  The present invention relates to an occupant protection device for a vehicle such as an automobile.

  Patent Documents 1 to 3 disclose a pre-tension mechanism that winds up a strap of a seat belt device that is passed in front of an occupant seated on a seat of an automobile before or after the collision. By the pretensioning operation, the back surface of the occupant seated on the seat is pressed against the backrest of the seat before or at the time of the collision, and the occupant's posture can be corrected when the occupant moves forward by the collision. Thereby, it becomes easy to act on the passenger | crew of the state to which the impact load at the time of a collision was restrained appropriately with the strap, and it can be expected that the protection performance of the passenger at the time of the collision is obtained.

Japanese Patent Laid-Open No. 10-167000 JP 2000-142321 A JP 2011-152837 A

By the way, in recent vehicles, in addition to the seat belt device, an airbag device is provided.
Moreover, in the existing pretensioning mechanism described above, a pretensioning operation for winding the strap is started before or at the time of the collision, and the collision is performed as it is.
For this reason, there is a possibility that a compression load due to the contact of the deployed airbag will act on the part where the strap of the occupant's body abuts, for example, the chest, in addition to the compression pressure by the pretensioning operation for correcting the posture. There is. And if it collides after that, the impact load by a collision will also act. There is a high possibility that these three types of forces are directly added and act on the contact portion.

  As described above, in the vehicle occupant protection device, it is required to reduce the force acting on the portion of the occupant's body against which the strap abuts.

  A vehicle occupant protection device according to the present invention includes a strap that is stretched in front of the body of an occupant seated on a vehicle seat, a pretensioner that winds the strap, and the pretensioner before or during a collision. A control unit that starts winding the strap; and an airbag device that deploys an airbag around the occupant in the vehicle, and the control unit starts winding the strap, The winding of the strap is temporarily stopped or loosened according to the deployed state of the airbag.

  Preferably, the control unit may temporarily stop or loosen the winding of the strap when the airbag is deployed after starting the winding of the strap.

  Preferably, the airbag includes a deployment sensor that detects a deployment state of the airbag, and the control unit overlaps the airbag and the strap based on a deployment state of the airbag detected by the deployment sensor. If there is a possibility of hitting the passenger, the winding of the strap may be temporarily stopped or loosened.

  Preferably, the control unit may temporarily stop or loosen the winding of the strap at an early stage of deployment when at least a part of the airbag is not inflated.

  Preferably, the control unit may resume the winding of the strap again in the middle of deployment after the entire airbag starts to inflate.

  Preferably, the control unit may temporarily stop or loosen the winding of the strap again at a later stage of deployment after the entire airbag is inflated to a desired shape.

  Preferably, the vehicle has an occupant state sensor that detects the state of the occupant, and the control unit detects whether the airbag is in the deployed state detected by the deployment sensor and the state of the occupant detected by the occupant state sensor. Accordingly, the winding of the strap may be controlled.

  Preferably, the occupant state sensor includes a belt tension sensor that detects a tension acting on the strap, and a belt winding sensor that detects a winding amount of the strap, and the control unit includes the belt Based on the correlation between the detection value of the tension sensor and the detection value of the belt winding sensor, the winding of the strap by the pretensioner is controlled, and the winding of the strap is controlled according to the deployment state of the airbag. It is good to change the target range or target value at.

  Preferably, the control unit lowers the upper limit value or the target value of the target range of the belt tension at the initial stage of deployment of the airbag.

  Preferably, the control unit lowers the upper limit value or the target value of the target range of the belt tension in the latter stage of deployment of the airbag.

  Preferably, the vehicle has a traveling state sensor that detects a traveling state of the vehicle, and the control unit predicts a collision of the vehicle before the collision based on the detection of the traveling state sensor, and uses the pretensioner. It is preferable that winding of the strap is started, and when the airbag is deployed during the winding control of the strap by the pretensioner, winding of the strap by the pretensioner is stopped or temporarily loosened.

  Preferably, the vehicle has an impact sensor that detects a collision of the vehicle or a movement of the body due to the collision, and the control unit uses the strap by the pretensioner with reference to a detection timing of the collision or the movement by the impact sensor. It is good to stop or temporarily loosen the winding.

  Preferably, the control unit sends out the strap so as to release the restraint state of the body with respect to the seat in the control of temporarily loosening the winding of the strap.

In the present invention, winding of the strap by the pretensioner is started before or during the collision. Pretensioning can support the occupant's body correctly.
In addition, after starting the winding of the strap, the winding of the strap is temporarily stopped or loosened according to the deployed state of the airbag. Therefore, even if the compression pressure due to the pretensioning action is applied to the contact portion of the strap for the occupant, it can be reduced by resetting it. The pressure applied by the pre-tension and the pressure applied by the deployed airbag are added as they are to the strap contact part, making it difficult to act. In addition, even if an impact load due to a collision subsequently acts, these three types of forces are added as they are, making it difficult to act on the contact portion.

FIG. 1 is an explanatory diagram of an automobile according to a first embodiment of the present invention. FIG. 2 is an explanatory diagram of an example of a vehicle occupant protection device provided on the vehicle body of FIG. FIG. 3 is an explanatory diagram of an example of an occupant protection operation by a general occupant protection device. 4 is a block diagram of a control system of the occupant protection device of FIG. FIG. 5 is a flowchart of occupant protection control by the control unit of FIG. FIG. 6 is an explanatory diagram of an example of an occupant protection operation (first half) by the control of FIG. FIG. 7 is an explanatory diagram of an example of an occupant protection operation (second half) by the control of FIG. FIG. 8 is a flowchart of occupant protection control in the second embodiment. FIG. 9 is a characteristic diagram showing an example of the correspondence between the belt tension and the belt winding amount corresponding to the chest displacement. FIG. 10 is a timing chart showing an example of strap winding control in accordance with the deployed state of the airbag.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

[First Embodiment]
FIG. 1 is an explanatory diagram of an automobile 1 according to the first embodiment of the present invention. The automobile 1 is an example of a vehicle. FIG. 1 also shows another vehicle 1 that travels in front of the vehicle 1.

  An automobile 1 in FIG. 1 has a vehicle body including a front chamber 2, a passenger compartment 3, and a rear chamber 4. In the front chamber 2, a power unit such as an engine and an electric motor is arranged. A luggage space is provided in the rear chamber 4. The passenger compartment 3 is provided with a seat 5 on which an occupant is seated. In the passenger compartment 3, operating members such as an accelerator pedal, a brake pedal, and a handle are provided in front of the driver's seat 5. The automobile 1 travels, stops, and turns left and right based on the driver's operation.

FIG. 2 is an explanatory diagram of an example of a vehicle occupant protection device provided on the vehicle body of FIG.
FIG. 2 shows a three-point seat belt device 10 and an airbag device 35.

The seat belt device 10 includes a strap 11, an anchor 12, a tongue plate 13, a buckle 14, a retractor device 15, and a holder 16.
The strap 11 is a belt that is stretched in front of the body of an occupant seated on the seat 5.
The anchor 12 fixes the tip of the strap 11 at a position outside the seat surface of the seat 5.
The strap 11 is passed through the tongue plate 13.
The buckle 14 is fixed to the inner position of the seat surface of the seat 5. The tongue plate 13 is detachably attached to the buckle 14.
The retractor device 15 includes a reel 17 that winds up the strap 11, a motor 18 that drives the reel 17 to rotate forward and backward with an arbitrary torque, and a gas generator (not shown) that instantaneously rotates the reel 17 in the winding direction. Have. The motor 18 and the gas generator can function as a pretensioner that winds the strap 11 before the collision.
The retractor device 15 is provided at a position below and outside the seat 5, such as a lower portion of the B pillar.
The holder 16 is provided at an upper position outside the seat 5 such as an upper part of the B pillar. The strap 11 is passed through the holder 16.
Then, the occupant seated on the seat 5 pulls the tongue plate 13 to pull out the strap 11 from the retractor device 15, and attaches the tongue plate 13 to the buckle 14. As a result, the strap 11 extends from the holder 16 toward the buckle 14, further extends from the buckle 14 toward the anchor 12, and is stretched around the waist and chest of the occupant seated on the seat 5.

The airbag device 35 includes an airbag main body 36, an airbag 37, and an inflator 38.
The airbag main body 36 accommodates an airbag 37 and an inflator 38.
The airbag 37 has a bag. The airbag 37 is provided with a gas blowing valve.
The inflator 38 blows out high-pressure gas into the airbag 37.
The airbag main body 36 of the airbag apparatus 35 of FIG. 2 is provided in a handle | steering-wheel or a dashboard, for example. The airbag in which the high-pressure gas is injected from the inflator 38 is deployed rearward from the handle or the dashboard. As a result, the airbag 37 is deployed in front of an occupant seated on the seat 5 in the vehicle.

FIG. 3 is an explanatory diagram of an example of an occupant protection operation by a general occupant protection device.
Prior to the collision, as shown in FIG. 3A, the strap 11 of the seat belt device 10 is suspended in front of an occupant seated on the seat 5. At this point, the strap 11 may be loose and may not be restrained to press the occupant's body against the seat 5.
Next, for example, when a collision is predicted, the pretensioner of the retractor device 15 operates to wind the strap 11 as shown in FIG. Accordingly, the occupant's body can be restrained to press against the seat 5. Moreover, the retractor apparatus 15 hold | maintains the strap 11 so that it may not be drawn out with the torque below predetermined.
As described above, the back of the occupant seated on the seat 5 is pressed against the backrest of the seat 5 before or after the collision by the pre-tension operation before the collision. When the passenger moves forward due to the collision, the posture of the passenger can be corrected. It can be expected that the impact load at the time of collision easily acts on the occupant in a state of being restrained appropriately by the strap 11, and the protection performance of the occupant at the time of collision can be expected.
Next, as shown in FIG. 3 (C), when the vehicle body actually collides with, for example, another automobile 1 in FIG. 1, the airbag device 35 moves the airbag 37 from the front as shown in FIG. 3 (D). Expand later.
Accordingly, the occupant's body seated on the seat 5 tends to move relatively forward from the seat 5, but can be supported by the airbag 37 that has been deployed.

However, in these existing pretensioning mechanisms, a pretensioning operation for winding the strap 11 is started before or at the time of the collision, and the collision occurs as it is. For this reason, in addition to the compression pressure by the pretensioning operation for correcting the posture, a compression load caused by the deployment of the deployed airbag 37 acts on a portion of the occupant's body where the strap 11 abuts, for example, the chest. there is a possibility. And if it collides after that, the impact load by a collision will also act. There is a high possibility that these three types of forces are directly added and act on the contact portion.
Therefore, in the present embodiment, the force acting on the part of the occupant's body against which the strap 11 abuts is reduced, and the occupant protection performance is enhanced.

  4 is a block diagram of a control system of the occupant protection device of FIG.

  4 includes an imaging device 21, a vehicle acceleration sensor 22, a vehicle speed sensor 23, a brake operation sensor 24, a vehicle angular speed sensor 25, a belt tension sensor 26, a belt winding amount sensor 27, a seating sensor 28, and a deployment sensor 31. , A timer 29, and a control unit 30 to which these are connected. FIG. 4 also shows the seat belt device 10 and the airbag device 35 that are controlled objects connected to the control unit 30.

  The imaging device 21 is, for example, a pair of imaging elements, and is provided forward on the roof of the passenger compartment 3 as shown in FIG. 1, and observes the surrounding situation in front of the vehicle by imaging. The control unit 30 can identify an obstacle such as another automobile 1 in front of the vehicle, for example, as a surrounding situation of the vehicle from the captured image, and can determine the possibility of the collision of the obstacle. Thereby, the traveling state of the vehicle before the collision can be detected.

  The vehicle acceleration sensor 22 is fixed to the vehicle body, and detects the acceleration of the vehicle due to acceleration / deceleration as the running state of the vehicle. Thereby, the posture change of the vehicle before the collision can be detected. Further, since a large deceleration occurs at the time of a collision, a vehicle collision can be detected.

  The vehicle speed sensor 23 is fixed to the vehicle body and detects the speed of the vehicle as the traveling state of the vehicle.

  The brake operation sensor 24 is provided in the passenger compartment 3 and detects a depression operation of the brake pedal by the passenger.

  The vehicle angular velocity sensor 25 is fixedly provided at the front portion or the rear portion of the vehicle body, and detects, for example, the angular velocity in the vertical direction of the vehicle as the traveling state of the vehicle.

  The belt tension sensor 26 is provided in the retractor device 15, for example, and detects the tension acting on the strap 11. Accordingly, it is possible to detect the movement of the occupant's body that moves relatively forward during deceleration or the tension acting on the strap 11 due to the movement of the body. Thereby, a passenger | crew's state can be detected.

  The belt winding amount sensor 27 is provided, for example, in the retractor device 15 and detects the winding amount of the strap 11. Thereby, a passenger | crew's state can be detected.

  The seating sensor 28 is provided, for example, on the seating surface of the seat 5 and detects the presence / absence of seating of the occupant on the seat 5, seating pressure, and seating position. In the event of a collision, the occupant's body tries to move forward. Thereby, a passenger | crew's state can be detected.

  The deployment sensor 31 is provided in the airbag main body 36, for example, and detects the deployment state of the airbag 37. As the deployment state of the airbag 37, for example, at the initial deployment stage where at least a part of the airbag 37 is not inflated, during the middle deployment period after the entire airbag 37 starts to be inflated, the entire airbag 37 is inflated to a desired shape. There are later stages of development. The deployment sensor 31 may determine these deployment states based on, for example, a pressure change in the airbag 37.

  The timer 29 measures time.

  The control unit 30 controls the occupant protection operation by the seat belt device 10 and the airbag device 35 based on the detection signals of these sensors. For example, the control unit 30 performs pre-collision control in which the strap 11 is wound up by the pretensioner based on the collision prediction, and performs the on-collision control based on the collision detection.

FIG. 5 is a flowchart of occupant protection control by the control unit 30 of FIG. The control unit 30 repeatedly executes the process of FIG. 5 to control the winding of the strap 11 by the pretensioner.
6 and 7 are explanatory diagrams of an example of an occupant protection operation by the control of FIG. Time flows in the order from FIG. 6 (A) to FIG. 6 (C) and further from FIG. 7 (A) to FIG. 7 (C). Then, the vehicle 1 collides with another vehicle 1 at the timing of FIG.

As shown in FIG. 5, the control unit 30 periodically predicts a collision (step ST1). The control unit 30 may determine the possibility of a collision that is not easy to avoid.
For example, the control unit 30 specifies an obstacle such as another automobile 1 in front of the vehicle from the image in front of the vehicle imaged by the imaging device 21. If an obstacle is specified, the possibility of collision is determined. If there is a possibility of collision, predict the time to collision. For example, the appearance of an obstacle nearby is different between images of a pair of image sensors arranged in the vehicle width direction. Therefore, nearby obstacles can be identified based on the difference between the obstacles in the pair of images. Further, the direction and distance of the obstacle can be calculated by trigonometry from the arrangement of the pair of imaging elements and the imaging position of the obstacle in the pair of images. From this distance and the vehicle speed by the vehicle speed sensor 23, the time until the vehicle reaches the obstacle and collides can be calculated. Further, the control unit 30 predicts the moving direction and distance of the obstacle from the information on the direction and distance of the plurality of sets of obstacles that move forward and backward in time, and predicts the collision with the obstacle based on the prediction result. May be.
In addition, for example, the control unit 30 is based on a rapid vehicle deceleration for avoiding a collision detected by the vehicle acceleration sensor 22 or a rapid deceleration operation for avoiding a collision detected by the brake operation sensor 24. Thus, the possibility of a collision may be determined.

And when the possibility of a collision is anticipated, the control part 30 starts winding of the strap 11 by a pretensioner before a collision (step ST2). In this case, the control unit 30 may drive the motor 18 in the winding direction. Thereby, winding of the strap 11 spanned in front of the passenger | crew's body is started before a collision. The occupant's body is restrained by the strap 11 and pressed against the seat 5. The occupant's body is corrected to the correct posture with the back touching the seat 5. For example, as shown in FIG. 6A, the upper body of the occupant who is separated from the seat 5 forward is pressed against the seat 5 before the collision by being restrained by the strap 11 as shown in FIG. 6B.
Conversely, when the possibility of a collision is not expected, the control unit 30 ends the process of FIG.

  After starting the winding of the strap 11 by the pretensioner, the control unit 30 detects a collision (step ST3). Specifically, for example, the detection of an impact sensor such as the vehicle acceleration sensor 22 or the belt tension sensor 26 is monitored. The control unit 30 determines that a collision has occurred when the vehicle acceleration sensor 22 detects a high acceleration at the time of collision or when the belt tension sensor 26 detects a high tension at the time of collision.

When a collision is detected as shown in FIG. 6C, the control unit 30 ignites the inflator 38 of the airbag device and deploys the airbag 37 from the front to the rear by the high-pressure gas generated thereby. Thereby, deployment of the airbag 37 is started (step ST4).
Some airbags 37 take time from the start of deployment to the later stage of deployment. In this case, the control unit 30 may ignite the inflator 38 of the air bag device based on the elapsed time from the expected collision timing measured by the timer 29.
A portion of the airbag 37 is inflated in the initial stage of deployment when deployment is started. At this time, the airbag 37 is deployed so as to extend from the front to the rear as shown in FIG.
In the middle deployment stage in which the front-to-back deployment is finished, the airbag 37 starts to inflate as a whole as shown in FIG.
The entire airbag 37 swells into a substantially desired shape. Thereafter, the internal pressure of the airbag 37 increases. Thereby, as shown in FIG. 7C, the airbag 37 can support an occupant attempting to move relatively forward in the event of a collision from the front.
In the later stage of deployment after the airbag 37 is deployed, gas begins to leak from the valve of the airbag 37. Thereafter, the airbag 37 shrinks as the internal pressure decreases.

  Further, when a collision is detected as shown in FIG. 6C, the control unit 30 temporarily stops or loosens the strap 11 that has been wound up by the pre-tensioning operation so far depending on the deployed state of the airbag 37. Implement control. During the winding control of the strap 11 by the pretensioner, a control for stopping or temporarily loosening the winding of the strap 11 is performed based on the detection timing of the collision or the movement.

First, at the initial deployment of the airbag 37 shown in FIG. 7A, the control unit 30 temporarily stops or loosens the winding of the strap 11 (step ST5). Here, the control unit 30 may send out the strap 11 so as to release the restraint state of the body with respect to the seat 5. As a result, as shown in FIG. 7A, it is difficult for the hard airbag 37 to hit the upper body of an occupant that may be deformed by the pretensioning operation while remaining in a thin plate shape. Become.
In the next deployment middle period of the airbag 37, the control unit 30 takes up the strap 11 again (step ST6). Here, the control unit 30 may drive the motor 18 with a winding torque before being loosened. Accordingly, the body that has moved forward after correction in FIG. 6B can be restrained so as to be appropriately pressed against the sheet 5 as shown in FIG. 7B. Before the airbag 37 can be supported, it can be properly pressed against the seat 5.
In the later deployment stage of the next airbag 37, the airbag 37 is inflated to a desired shape as a whole and its internal pressure is increased. Therefore, the control unit 30 stops the winding of the strap 11 again or temporarily. (Step ST7). The body that is about to move forward due to the collision can be supported by the airbag 37 deployed at a high internal pressure.
The control unit 30 may control the series of controls based on the elapsed time from the time of the collision measured by the timer 29, for example. Or you may control by the elapsed time from the deployment start timing of the airbag 37. FIG. Thereby, the tension of the strap 11 can be adjusted at a timing that suitably corresponds to the deployed state of the airbag 37 that starts to be deployed at the time of a collision.

As described above, in the present embodiment, winding of the strap 11 by the pretensioner is started before or at the time of the collision. Pretensioning can support the occupant's body correctly.
In addition, after the winding of the strap 11 is started, the winding of the strap 11 is temporarily stopped or loosened according to the deployed state of the airbag 37. Therefore, even if the compression pressure by the pretensioning action is applied to the contact portion of the strap 11 for the occupant, it can be reduced by resetting it. The pressure applied by the pre-tension and the pressure applied by the deployed airbag 37 are added as they are to the contact portion of the strap 11 to make it difficult to act. In addition, even if an impact load due to a collision subsequently acts, these three types of forces are added as they are, making it difficult to act on the contact portion.

In particular, since the airbag 37 in the initial stage of deployment is a lump in which gas does not invade locally, there is a possibility that the hard airbag 37 may hit the occupant locally. By releasing the compression pressure at the time of pre-tensioning at or before this timing, a synergistic high compression pressure can hardly be applied to the occupant.
Further, since the winding of the strap 11 is resumed again in the middle deployment period after the entire airbag 37 starts to inflate, the occupant who intends to move forward in the period including the latter deployment stage after the middle deployment stage is returned to the strap 11. Thus, it can be sufficiently restrained to be pressed against the sheet 5. At this timing, since the massive airbag 37 is loosened, it is difficult for pressure to be generated by the rigid airbag 37 at the initial stage of deployment.
Further, in the latter stage of deployment after the entire airbag 37 is inflated to a desired shape, the winding of the strap 11 is temporarily stopped or loosened again. At this timing, since the airbag 37 is fully deployed in a desired shape, even if the winding of the strap 11 is loosened, the occupant trying to move forward can be supported by the airbag 37. If it does not loosen, the inertia of the occupant is supported by the strap 11 while being wound up, and there is a possibility that high compression pressure acts on the contact portion of the strap 11 with respect to the body.

[Second Embodiment]
The second embodiment of the present invention is different from the first embodiment in occupant protection control. In the following, differences from the first embodiment will be mainly described, and description of the configuration and operation common to the first embodiment will be omitted.

  FIG. 8 is a flowchart of occupant protection control in the second embodiment.

As shown in FIG. 8, the control unit 30 periodically predicts a collision (step ST11). The control unit 30 determines the possibility of a collision that is difficult to avoid.
When the possibility of a collision is predicted, the control unit 30 further acquires the deployment state of the airbag 37 detected by the deployment sensor 31 and the occupant state detected by the occupant state sensor (step ST12).
Then, the control unit 30 controls the winding of the strap 11 by the pretensioner based on the correlation between the detection value of the belt tension sensor 26 and the detection value of the belt winding amount sensor 27. Specifically, the winding of the strap 11 is started while changing the target range or the target value in the winding control of the strap 11 according to the deployed state of the airbag 37 (step ST13).

FIG. 9 is a characteristic diagram showing an example of the correspondence between the belt tension and the belt winding amount corresponding to the chest displacement.
The horizontal axis represents the belt tension, and the belt winding amount corresponding to the occupant's chest displacement.
FIG. 9 shows a solid line indicating a case where the relationship is good and a broken line indicating a case where the relationship is not good.
The chest of the occupant is greatly deformed as the strap 11 is wound up. Therefore, when this favorable relationship is maintained, the solid line relationship in FIG. 9 is established.
On the other hand, for example, when the occupant's chest has already been tightened and is difficult to deform further, the belt tension is increased without increasing the winding amount of the strap 11 as shown by the broken line in FIG. growing.

Then, when the belt airbag 37 in the initial stage of deployment hits the occupant's chest in a state where the belt tension is high, the displacement of the occupant's chest at that moment increases.
Therefore, specifically, the control unit 30 lowers the upper limit value or the target value of the target range of the belt tension at the initial stage of deployment of the airbag 37, and winds the strap 11 within the target range.
Thereafter, when a predetermined elapsed time is measured by the timer 29, the control unit 30 returns the upper limit value or the target value of the target range of the belt tension to the original value, and winds the strap 11 within the target range.
As a result, even if the hard airbag 37 in the initial deployment hits the occupant's chest, displacement of the occupant's chest can be suppressed.

Further, in the later stage of deployment after the airbag is deployed, the occupant can be prevented from moving forward even if the occupant's body is not tightened by the strap 11.
Therefore, specifically, the control unit 30 lowers the upper limit value or the target value of the target range of the belt tension at the initial stage of deployment of the airbag 37, and winds the strap 11 within the target range.
Thereafter, when a predetermined elapsed time is measured by the timer 29, the control unit 30 returns the upper limit value or the target value of the target range of the belt tension to the original value, and winds the strap 11 within the target range.
Thereby, in a state where the airbag 37 in the latter deployment stage that can sufficiently support the occupant is deployed, the strap 11 is loosened and the occupant is supported by the airbag 37 so that the chest displacement of the occupant does not continue for a long time. be able to.
Thereafter, the airbag 37 after being deployed contracts as the gas leaks from the valve and the internal pressure decreases.

FIG. 10 is a timing chart showing an example of the winding control of the strap 11 according to the deployed state of the airbag 37.
In FIG. 10, the belt tension control characteristic line is shown by a solid line. The vertical axis in FIG. 10 is the force acting on the chest, and the horizontal axis is time.
And the pretension of the strap 11 is started from the origin.
Further, in FIG. 10, the initial deployment stage, the middle deployment stage, and the later deployment stage of the airbag 37 are illustrated by arrows.
Thereafter, immediately after the start of deployment of the airbag 37, the belt tension decreases and then returns to the original state. As a result, as shown by the broken line in FIG. 10, even if the massive airbag 37 hits the occupant and thereby a force acts on the chest of the occupant, the total force acting on the chest can be reduced.
Further, in the latter stage of deployment of the airbag 37, the belt tension is lowered again. In this case, since the airbag 37 has already been fully deployed, the upper body of the passenger trying to move forward can be supported by the airbag 37.

  The above embodiment is an example of a preferred embodiment of the present invention, but the present invention is not limited to this, and various modifications or changes can be made without departing from the scope of the invention.

1 ... Automobile (vehicle)
2 ... Front room 3 ... Passenger room 4 ... Rear room 5 ... Seat 10 ... Seat belt device 11 ... Strap 12 ... Anchor 13 ... Tongue plate 14 ... Buckle 15 ... Retractor device 16 ... Holder 17 ... Reel 18 ... Motor 21 ... Imaging device 22 ... Vehicle acceleration sensor 23 ... Vehicle speed sensor 24 ... Brake operation sensor 25 ... Vehicle angular speed sensor 26 ... Belt tension sensor 27 ... Belt take-up sensor 28 ... Seating sensor 29 ... Timer 30 ... Control unit 31 ... Deployment sensor 35 ... Air Bag device 36 ... Airbag body 37 ... Airbag 38 ... Inflator

Claims (13)

A strap that hangs in front of the body of an occupant seated in the vehicle seat;
A pretensioner for winding the strap;
A control unit for starting winding of the strap by the pretensioner before or during a collision;
An airbag device for deploying an airbag around the occupant in the vehicle;
Have
The control unit, after starting the winding of the strap, temporarily stops or loosens the winding of the strap according to the deployed state of the airbag,
Vehicle occupant protection device. The controller is
If the airbag is deployed after starting the winding of the strap, temporarily suspending or loosening the winding of the strap;
The vehicle occupant protection device according to claim 1. A deployment sensor for detecting a deployment state of the airbag;
The controller is
Based on the deployment state of the airbag detected by the deployment sensor, when there is a possibility that the airbag and the strap overlap and hit an occupant, the winding of the strap is temporarily stopped or loosened.
The vehicle occupant protection device according to claim 2. The controller is
Temporarily suspending or loosening the winding of the strap at an early stage of deployment when at least a portion of the airbag is not inflated;
The vehicle occupant protection device according to claim 3. The controller is
In the middle stage of deployment after the entire airbag begins to inflate, the winding of the strap is resumed again.
The vehicle occupant protection device according to claim 3 or 4. The controller is
In a later stage of deployment after the entire airbag is inflated to a desired shape, the strap is temporarily stopped or loosened again.
The vehicle occupant protection device according to claim 3 or 4. An occupant state sensor for detecting the state of the occupant,
The controller is
Controlling the winding of the strap according to the deployment state of the airbag detected by the deployment sensor and the state of the occupant detected by the occupant state sensor;
The vehicle occupant protection device according to any one of claims 3 to 6. As the occupant state sensor,
A belt tension sensor for detecting a tension acting on the strap; and a belt winding sensor for detecting a winding amount of the strap;
The controller is
Based on the correlation between the detection value of the belt tension sensor and the detection value of the belt winding sensor, the winding of the strap by the pretensioner is controlled,
According to the deployment state of the airbag, change the target range or target value in the winding control of the strap,
The vehicle occupant protection device according to claim 7. The controller is
In the initial deployment of the airbag, the upper limit value or the target value of the target range of the belt tension is lowered,
The vehicle occupant protection device according to claim 8. The controller is
Lowering the upper limit value or the target value of the target range of the belt tension in the later stage of deployment of the airbag,
The vehicle occupant protection device according to claim 8 or 9. A driving condition sensor for detecting the driving condition of the vehicle,
The controller is
Predicting the collision of the vehicle before the collision based on the detection of the traveling state sensor, starting the winding of the strap by the pretensioner,
When the airbag is deployed during the winding control of the strap by the pretensioner, the winding of the strap by the pretensioner is stopped or temporarily loosened.
The vehicle occupant protection device according to any one of claims 1 to 10. An impact sensor for detecting a collision of the vehicle or a movement of the body due to a collision,
The controller is
Stopping or temporarily loosening the winding of the strap by the pretensioner based on the detection timing of the collision or movement by the impact sensor;
The vehicle occupant protection device according to any one of claims 1 to 11. The control unit sends out the strap so as to release the restraint state of the body with respect to the seat in the control of temporarily loosening the winding of the strap.
The vehicle occupant protection device according to any one of claims 1 to 12.

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