JP4478945B2 - Vehicle occupant protection device - Google Patents

Description

  The present invention relates to a vehicle occupant protection device.

Conventionally, various measures have been taken to protect the occupant's legs during a vehicle collision.
For example, Patent Literature 1 below discloses that a knee airbag is provided on an under cover attached to an instrument panel below a steering wheel to protect an occupant's knee in the event of a vehicle collision.
Patent Document 2 below discloses that a floor airbag is provided on the lower surface of the floor panel in the vicinity of the pedal operation unit to protect the occupant's toes at the time of a vehicle collision.

JP-A-9-123863 Japanese Patent Laid-Open No. 10-310011

  However, when both the knee airbag and the floor airbag shown in Patent Documents 1 and 2 described above are provided, the effect of each airbag can be achieved by simply deploying both airbags at the time of collision. The present inventors have found that there is a possibility that it cannot be fully exhibited.

Referring now to FIG. 10, the configuration of the vehicle is schematically shown in (A). The vehicle 50 is a front engine vehicle, and an engine 51 is mounted on a frame 52 in front of the vehicle. 53 is a dash panel, and 54 is a steering wheel.
FIGS. 5B to 5D show the situation when the vehicle 50 of FIG. As for the collision mode of the vehicle, a full-lap collision in which the collision surface of the front surface of the own vehicle and the obstacle colliding with the own vehicle completely overlaps on the front surface of the vehicle, and an obstacle that collides with the front surface of the own vehicle and the own vehicle. There is an offset collision in which a collision surface with an object is partially biased. FIG. 4B shows a full wrap collision, FIG. 4C shows a right offset collision, and FIG. 4D shows a left offset collision.

In the case of the full lap collision shown in (B), the area of the own vehicle that receives the impact at the time of the collision is larger than the offset collision, and the amount of deformation of the vehicle body component such as the toe board on the vehicle front side is reduced to the vehicle interior side. On the other hand, the acceleration applied to the occupant increases, and the occupant is greatly moved to the front side of the vehicle.
Accordingly, the behavior of the occupant's legs at the time of full lap collision is that the knee collides with a position in front of the vehicle such as an instrument panel due to the movement of the occupant to the front side, and at that time, the floor airbag is deployed. Because the leg part of the toe does not move freely from the knee part, a large load is applied to the occupant's leg part.

On the other hand, in the case of the offset collision shown in (C) and (D), the area of the own vehicle that receives the impact at the time of collision is smaller and the degree of deformation of the vehicle body is larger than in the case of full-lap collision. Specifically, for example, as shown in (C) or (D), at the time of a collision, the collision-side frame 52 is greatly deformed, and the engine 51 is largely retracted while falling downward. For this reason, the deformation amount of the vehicle body component such as the toe board on the vehicle front side toward the vehicle interior is large with respect to the full lap collision, and the acceleration applied to the occupant is small.
Therefore, the behavior of the occupant's legs at the time of an offset collision is that the toes move toward the rear upper side due to the intrusion of the toe board or the like and the deployment of the floor airbag. If the bag is fixed by the deployment of the bag, the leg part of the toe does not move freely from the knee part, so that a large load is applied to the occupant's leg part.

  As described above, if both the knee airbag and the floor airbag are simply deployed at the same time, the movement of the legs may be restricted, and a large load may be applied to the legs. The effect of the bag may not be fully demonstrated.

Further, the present inventors have found that, among the leg portions of the occupant, the portions affected by the obstacle are different depending on the difference in the collision form of the vehicle.
That is, as described above, in the case of a full lap collision, the acceleration applied to the occupant is large, and the occupant is greatly moved to the front side of the vehicle, so there is a concern that a burden is applied to the occupant's knee.
On the other hand, in the case of an offset collision, the amount of deformation of a vehicle body component such as a toe board on the vehicle front side to the vehicle interior side is large compared to a full lap collision, so that the toe board that has entered may put a burden on the occupant's feet. Concerned. On the other hand, as described above, the amount of deformation of the vehicle body component toward the passenger compartment is large, and the acceleration applied to the occupant is small. There is little concern about the burden on Therefore, in the case of an offset collision, there is a concern that a burden is placed on the occupant's feet.
As described above, it can be seen that the portion of the occupant's leg where the burden is a problem is different depending on the collision mode.
In other words, since the legs to be protected preferentially differ according to the collision mode, it is possible to protect the passenger's legs without necessarily deploying both the knee airbag and the floor airbag. The present inventors have found that this is the case.

  The present invention has been made in consideration of the above-described problems, and its purpose is to prevent the effect of the airbag from being sufficiently exerted due to the occupant's legs not freely moving during a vehicle collision. An object is to provide a vehicle occupant protection device.

In order to achieve the above object, a vehicle occupant protection device according to one aspect of the present invention comprises the following arrangement.
That is, an occupant protection device for a vehicle that protects an occupant's legs in a collision from the front of the vehicle, and is provided in an engine room disposed in front of the vehicle and a toe board behind the engine room to protect the occupant's toes. A floor airbag, a knee airbag that is provided below the instrument panel on the vehicle interior side and protects the occupant's knee, a collision type determination means that determines whether the collision is a full lap collision or an offset collision, and the collision In the case of a full wrap collision, the knee airbag is deployed while restricting the deployment of the floor airbag. On the other hand, if the collision is an offset collision, the deployment of the knee airbag is regulated. And an airbag control means to be deployed.

According to the above configuration, the knee airbag is preferentially deployed when it is a full lap collision, while the floor airbag is preferentially deployed when it is an offset collision. For this reason, in the case of a full wrap collision where there is a concern about obstacles to the knee, while deploying the knee airbag, the knee airbag is protected and the deployment of the floor airbag is restricted, and the freedom of movement of the legs downward Can be secured, and the burden on the legs can be reduced.
In addition, in the case of an offset collision, while protecting the toes by deploying the floor airbag, the deployment of the knee airbag is restricted and the degree of freedom of upward movement of the leg can be secured. Can be reduced.

  By the way, as can be seen by referring to FIGS. 10C and 10D, in the case of an offset collision, the collision-side frame is greatly deformed, and the engine 51 rotates while descending downward, and retreats greatly. Therefore, in the seat on the same side as the offset collision side, the vehicle body component such as a toe board approaches the occupant, so that the occupant's feet can be protected (while regulating the deployment of the knee airbag as described above) ) Floor airbags need to be deployed immediately. On the other hand, since the retraction amount of the engine 51 is small in the seat on the other side from the side where the offset collision occurred, there is no situation in which a vehicle body component member such as a toe board approaches the seat. Then, it can be said that there is no need to deploy the floor airbag in the seat on the other side of the side where the offset collision occurred.

  Therefore, according to a preferred embodiment of the present invention, when the collision is an offset collision, the airbag further includes a left-right offset collision determination unit that determines whether the offset collision is a right offset collision or a left offset collision. When the collision is an offset collision, the control means regulates the deployment of the knee airbag in the seat on the same side as the offset collision generation unit side determined by the left and right offset collision determination means, while controlling the deployment of the seat on the same side. It is preferable to deploy the floor airbag.

  According to such a configuration, the floor airbag can be deployed only in the seat on the same side as the side on which the offset collision has occurred, and thereby deployment of a useless airbag can be suppressed.

  Further, the airbag control means further regulates the deployment of the floor airbag on the other side seat with respect to the offset collision occurrence portion side determined by the left and right offset collision determination means, while the knee airbag of the other side seat is restricted. Is preferably developed.

  According to this configuration, the knee airbag is deployed in a state where the deployment of the floor airbag on the seat on the other side of the side where the offset collision has occurred is restricted, so that the degree of freedom of the occupant's toe is ensured. Meanwhile, the knee can be protected by the knee airbag. Such a knee protection can reduce the burden on the legs.

  According to a preferred embodiment of the present invention, when the airbag control means deploys the knee airbag in response to the collision being determined by the collision form determination means as a full lap collision, It is preferable that the floor airbag is further deployed after a predetermined delay time has elapsed since the deployment of the knee airbag.

Here, even in the case of a full lap collision, if the impact at the time of the collision is large, there is a concern about the burden on the occupant's feet due to the intrusion of the toeboard into the vehicle interior side, so it is necessary to protect the toes. is there.
The behavior of the occupant's legs at the time of a full lap collision is as follows. First, the knee collides with a position in front of the vehicle such as an instrument panel by the movement of the occupant to the front side, and then the toes move downward. Trying to move, but once the leg is fully extended and its position is determined, the impact on the leg is less affected, and even if the floor airbag is deployed, there is no impact on the leg .
In this regard, according to the above configuration, the floor airbag is deployed after a predetermined delay time after the knee airbag is deployed at the time of a full wrap collision, so that the toe extends after the knee airbag is deployed downward. After it has been exhausted, the floor airbag can be deployed. For this reason, the freedom degree of the downward movement of a leg part can be ensured, and protection of a foot tip can be aimed at, reducing the burden to a leg part.

  According to a preferred embodiment of the present invention, when the airbag control unit deploys the floor airbag in response to the collision type determination unit determining that the collision is an offset collision, It is preferable that the knee airbag is further deployed after a predetermined delay time has elapsed since the deployment of the floor airbag.

Here, even in the case of an offset collision, if the impact at the time of the collision is large, acceleration is applied to the occupant and there is a concern about the burden on the knee, so it is necessary to protect the knee.
The behavior of the occupant's leg at the time of the offset collision is as follows. First, the occupant's feet are about to move upward due to the deployment of the floor airbag. If the position is determined, the influence on the legs is small, and even if the knee airbag is deployed, there is no influence on the legs.
In this regard, according to the above configuration, the knee airbag is deployed after a predetermined delay time has elapsed after the floor airbag is deployed at the time of an offset collision, so that the toe is fully extended upward after the floor airbag is deployed. After that, the knee airbag can be deployed. For this reason, the freedom degree of the upward movement of a leg part can be ensured, and protection of a knee part can be aimed at, reducing the burden to a leg part.

  According to a preferred embodiment of the present invention, the apparatus further comprises knee distance detection means for detecting a distance between the instrument panel and the knee of the occupant, wherein the airbag control means is configured to detect that the collision is an offset collision. In this case, it is preferable to restrict the deployment of the knee airbag when the detection distance by the knee distance detection means becomes a predetermined value or less.

Here, in the case of an offset collision, if the distance between the instrument panel and the occupant's knee is short, the knee airbag is not deployed and the degree of freedom of movement of the knee is lost, and the leg may be damaged.
In this regard, according to the configuration as described above, when the distance between the instrument panel and the occupant's knee is equal to or less than a predetermined value, the deployment of the knee airbag is restricted. Can be suppressed.

  According to a preferred embodiment of the present invention, it is preferable that the airbag control means further adjusts the deploying force of the floor airbag and / or knee airbag according to the impact force at the time of collision.

  According to this configuration, since the deployment force of the knee airbag and the floor airbag is adjusted according to the impact force at the time of the collision with the vehicle, the toeboard that is different depending on the difference in the impact force at the time of the collision. It is possible to appropriately protect the occupant's leg according to the amount of intrusion and the degree of burden on the occupant's leg.

  According to a preferred embodiment of the present invention, it is preferable that the airbag control means further adjusts the delay time according to an impact force at the time of collision.

  According to this configuration, the predetermined delay time until the floor airbag is deployed after the knee airbag is deployed at the time of the full lap collision, or until the knee airbag is deployed after the floor airbag is deployed at the time of the offset collision. Since the predetermined delay time is adjusted according to the impact force at the time of the collision with the vehicle, the toe board intrudes into the passenger compartment and the degree of burden on the occupant's leg depending on the impact force at the time of the collision. Accordingly, it is possible to appropriately protect the legs of the occupants.

  ADVANTAGE OF THE INVENTION According to this invention, it can suppress that the effect of an airbag cannot fully be exhibited because a passenger | crew's leg part cannot move freely at the time of a vehicle collision.

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

FIG. 1 shows an overall configuration diagram relating to the present embodiment. The vehicle 1 is, for example, a front engine vehicle, and an engine room (shown by a broken line) 15 is provided in the front body as illustrated. Although not shown, the engine is mounted on the frame in the engine room 15.
On the lower side of the instrument panel 4 in front of the driver seat 2 and the passenger seat 3 of the vehicle 1, floor airbags 5, 5 and knee airbags 6, 6 are provided, respectively.
Further, knee distance detection sensors 7 and 7 for detecting the distance between the knee part of the occupant seated in each seat 2 and 3 and the instrument panel 4 are provided on the lower side of the instrument panel 4. Yes.
A right front G sensor 8 and a left front G sensor 9 are provided on the left and right sides of the front side of the vehicle 1, and a floor G sensor 10 is provided on the floor below the instrument panel 4.
Further, a dash panel retraction amount detection sensor 13 for detecting a distance between the dash panel 11 and the pillar 12 is provided.

Next, the input / output relationship with respect to the control unit (ECU) 50 as the airbag control means according to this embodiment will be described based on the control block diagram of FIG.
In FIG. 2, the control unit 50 detects the distance between the instrument panel 4 and the knee of the occupant, for example, a knee distance detection sensor 7 capable of detecting the distance between them using ultrasonic waves, radio waves, lasers, or the like. , A right front G sensor 8 for detecting the magnitude of acceleration input to the front right side of the vehicle, a left front G sensor 9 for detecting the magnitude of acceleration input to the front left side of the vehicle, and an acceleration input near the center of the vehicle. The distance between the floor G sensor 10 for detecting the size and the distance between the dash panel 11 and the pillar 12 can be detected by, for example, an ultrasonic wave, a radio wave, a laser, or the like. A detection signal from a dash panel retraction amount detection sensor 13 that indirectly detects a retraction amount of a toe board (not shown) provided in the vehicle is input. Going on.
Further, the control unit 50 is configured to control the inflator 5a for deploying the floor airbag 5 and the inflator 6a for deploying the knee airbag 6 based on detection signals input from the sensors.

(Embodiment 1)
Next, deployment control of the inflator 5a of the floor airbag 5 and the inflator 6a of the knee airbag 6 relating to the first embodiment will be described with reference to FIGS.
FIG. 3 is a flowchart relating to the first embodiment, FIG. 4 is a diagram showing an airbag deployment state relating to the embodiment 1, and FIG. 5 is a time chart showing the deployment state of each airbag.

In step S1 of FIG. 3, detection signals detected by the right front G sensor 8, the left front G sensor 9, and the floor G sensor 10 are read.
In step S2, it is determined whether or not the vehicle has collided based on detection signals from the right front G sensor 8, the left front G sensor 9, and the floor G sensor 10. For example, when all the G sensors 8, 9, and 10 detect G that is equal to or greater than a predetermined value, it is determined that a collision has occurred.
When it determines with YES by step S2, it progresses to step S3 and determines a collision form.
For example, the difference 1 between the acceleration detected by the right front G sensor 8 and the acceleration detected by the floor G sensor 10, and the acceleration detected by the left front G sensor 9 and the acceleration detected by the floor G sensor 10 A difference 2 is obtained, and a deviation 3 which is a deviation between the difference 1 and the difference 2 is obtained. When the deviation 3 is equal to or less than a predetermined value, that is, when the acceleration of the vehicle with respect to the left and right is substantially the same, it is considered that the acceleration is applied substantially evenly to the front surface of the vehicle. On the other hand, if the obtained deviation 3 is equal to or greater than a predetermined value, that is, there is a difference in G with respect to the left and right of the vehicle, it is considered that the acceleration is applied biased to either the left or right in front of the vehicle. Is determined to be an offset collision from the larger side.

In step S4, it is determined whether or not the collision mode determined in step S3 is a full lap collision.
When it is determined NO in step S4, that is, when it is determined that the collision is an offset collision, the process proceeds to step S5, where the impact force is calculated based on the acceleration detected by the floor G sensor, and then in step S6, step S6 is performed. As the impact force calculated in S5 is higher, a larger deployment force (deployment pressure) is set, and in step S7, the inflator 5a is controlled based on the deployment force (deployment pressure) set in step S6. Is expanded.

  When it is determined YES in step S4, that is, when it is determined that a full lap collision has occurred, the process proceeds to step S8, where the impact force is calculated based on the acceleration detected by the floor G sensor, and then step S9. In step S8, a deployment force (deployment pressure) is set according to the impact force calculated in step S8. In step S10, the inflator 6a is controlled based on the deployment force (deployment pressure) set in step S9. Only expands.

Therefore, according to the first embodiment, as shown in FIGS. 4 (1) and 5 (1), in the case of an offset collision, only the floor airbag is deployed. The knee airbag 6 is not allowed to be deployed while ensuring freedom of movement of the legs upward, and the burden on the legs can be reduced.
In the case of a full lap collision, as shown in FIGS. 4 (2) and 5 (2), only the knee airbag 6 is deployed, while the knee airbag 6 is deployed to protect the knee and Deployment of the airbag 5 is prohibited, so that the degree of freedom of movement of the leg portion downward can be ensured, and obstacles to the leg portion can be reduced.

  Further, since the deployment force (deployment pressure) of the knee airbag 6 and the floor airbag 5 is set larger as the impact force at the time of collision with the vehicle is larger, the deformation of the vehicle body is larger as the impact force at the time of collision is larger. Even if the amount increases and the degree of burden on the occupant's legs due to the amount of penetration of the toe board into the passenger compartment and the acceleration applied to the occupant increases, the occupant's legs can be properly protected.

  In the first embodiment, an example in which only one airbag is deployed according to the collision mode and the deployment of the other airbag is completely prohibited at the time of a vehicle collision has been described. However, the degree of freedom of the occupant's legs is limited to some extent. The deployment force (deployment pressure) may be made smaller than usual so that the airbag can be secured, and the deployment speed of the airbag may be lowered.

(Embodiment 2)
Next, deployment control of the inflator 5a of the floor airbag 5 and the inflator 6a of the knee airbag 6 according to the second embodiment will be described with reference to FIGS.
In the first embodiment, at the time of a vehicle collision, an example in which only one airbag of the floor airbag 5 or the knee airbag 6 is deployed and the deployment of the other airbag is completely prohibited according to the collision mode. In the second embodiment, even in the case of an offset collision, the distance between the knee and the instrument panel 4 can be ensured to be a predetermined value or more after the leg part due to the collision has been fully extended upward. The knee airbag 6 is deployed to protect the knee, but even in a full wrap collision, the toe board is retracted after the leg has fully extended downward. In the case of continuing, an example is shown in which the floor airbag 5 is deployed to protect the toes.
6A to 6D are flowcharts related to the second embodiment, FIG. 7 is a diagram illustrating an airbag deployment state at the time of an offset collision according to the second embodiment, and FIG. 8 is a diagram illustrating an airbag deployment state at the time of a full wrap collision according to the second embodiment. 9 is a time chart showing the deployed state of each airbag.

In step S21 of FIG. 6A, detection signals detected by the right front G sensor 8, the left front G sensor 9, and the floor G sensor 10 are read.
In step S22, it is determined whether the vehicle has collided based on detection signals from the right front G sensor 8, the left front G sensor 9, and the floor G sensor 10. For example, when all the G sensors 8, 9, and 10 detect an acceleration equal to or higher than a predetermined value, it is determined that a collision has occurred.
When it determines with YES by step S22, it progresses to step S23 and determines a collision form.
For example, as in the first embodiment, the difference 1 between the acceleration detected by the right front G sensor 8 and the acceleration detected by the floor G sensor 10, and the acceleration detected by the left front G sensor 9 and the floor G sensor 10 A difference 2 from the detected acceleration is obtained, and a deviation 3 which is a deviation between the difference 1 and the difference 2 is obtained. When the deviation 3 is equal to or less than a predetermined value, that is, when the acceleration of the vehicle with respect to the left and right is substantially the same, it is considered that the acceleration is applied substantially evenly to the front surface of the vehicle. On the other hand, if the obtained deviation 3 is equal to or greater than a predetermined value, that is, there is a difference in G with respect to the left and right of the vehicle, it is considered that the acceleration is applied to either the left or right of the front of the vehicle. Is determined to be an offset collision from the larger side.

Subsequently, in step S241, it is determined whether or not the collision mode determined in step S23 is a full lap collision.
When it is determined NO in step S241, that is, when it is determined that there is an offset collision, control at the time of offset collision (processing block surrounded by a broken line) after step S242 is executed, and conversely YES in step S241. When it is determined, that is, when it is determined that it is a full lap collision, the control at the time of full lap collision in step S300 is executed.

In the offset collision control executed when it is determined that the collision mode is an offset collision, first, in step S242, it is determined whether or not the offset collision is a right offset collision.
For example, if the acceleration detected by the right front G sensor 8 is larger than the acceleration detected by the left front G sensor 9, it is determined that a right offset collision has occurred. On the other hand, if the acceleration detected by the left front G sensor 9 is larger than the acceleration detected by the right front G sensor 8, it is determined that a left offset collision has occurred.

  In the present embodiment, when it is determined in step S242 that the offset collision is a right offset collision, the “airbag deployment control A” in step S400 is applied to the driver seat that is the same seat as the offset collision generating unit. ”Is executed, and“ airbag deployment control B ”in step S500 is executed for the passenger seat that is the seat on the other side of the offset collision occurrence portion side.

FIG. 6B is a flowchart illustrating an example of a specific procedure of the airbag deployment control A in step S400 that is executed on the driver's seat side in the case of a right offset collision.
First, in step S25, an impact force is calculated based on the acceleration detected by the floor G sensor 10, and in the subsequent step S26, a larger deployment force (deployment pressure) is set as the impact force calculated in step S25 is larger. In step S27, the inflator 5a is controlled based on the deployment force (deployment pressure) set in step S26, and the floor airbag 5 on the driver's seat side is deployed. Note that the deployment of the knee airbag 6 is restricted at this point.

In a succeeding step S28, it is determined whether or not the delay timer T has been counted up to a predetermined value. That is, after the floor airbag 5 is deployed, it is determined whether or not a period of time has elapsed in which the occupant's leg portion is fully extended upward and the leg portion is located at a certain position.
If NO is determined in step S28, the process proceeds to step S29, the delay timer T is counted up, the process returns to step S28 again, and this loop is repeated until the delay timer T reaches a predetermined value.

When it is determined YES in step S28, that is, when it is determined that the legs of the occupant are fully extended after the floor airbag 5 is deployed and the positions of the legs are determined, the process proceeds to step S30. The detection signal detected by the knee distance detection sensor 7 is read.
In step S31, it is determined whether or not the distance between the knee and the instrument panel 4 is greater than or equal to a predetermined value.
When YES is determined in step S31, that is, when the distance between the knee and the instrument panel 4 is a predetermined value or more and the knee is not fixed even when the knee airbag 6 is deployed. The process proceeds to step S32.
In step S32, a larger deployment force (deployment pressure) is set as the impact force calculated in step S25 is larger. In step S33, the inflator 6a is controlled based on the deployment force (deployment pressure) set in step S32. The knee airbag 6 on the driver's seat side is deployed.
Further, when it is determined NO in step S31, the deployment of the knee airbag 6 is prohibited by leaving the airbag deployment control A as it is.

FIG. 6C is a flowchart showing an example of a specific procedure of the airbag deployment control B in step S500 executed for the passenger seat side in the case of a right offset collision.
First, in step S51, an impact force is calculated based on the acceleration detected by the floor G sensor 10, and it is determined whether the impact force is a predetermined value or more. If it is determined that the impact force is greater than or equal to the predetermined value, the process proceeds to step S52. On the other hand, when it is determined that the impact force is less than the predetermined value, the airbag deployment control B is exited as it is. That is, no airbag is deployed on the passenger seat side which is the seat on the other side from the offset collision occurrence side.
In step S52, a larger deployment force (deployment pressure) is set as the impact force calculated in step S51 is larger, and in step S53, the inflator 6a is operated based on the deployment force (deployment pressure) set in step S52. Control and deploy the passenger side knee airbag.

  As described above, in the present embodiment, in the case of an offset collision, the contents of the airbag deployment control differ between the driver seat side and the passenger seat side. In summary, on the driver's seat side, which is the same side as the offset collision, the engine mounted on the frame moves backward while dropping, as described above, and the body components such as the toe board approach the occupant. Therefore, as the airbag deployment control A, basically, the floor airbag 5 on the driver's seat side is deployed while regulating the deployment of the knee airbag 6 (step S27). As a result, while deploying the floor airbag to protect the toes, the deployment of the knee airbag is restricted and the freedom of movement upward of the leg can be secured, reducing the burden on the leg. can do.

  Further, as a mode of restricting the deployment of the knee airbag 6, it may be simply prohibited to deploy the knee airbag 6, but a predetermined delay time has elapsed after the floor airbag 5 is deployed as in the above example. It is preferable to deploy the knee airbag 6 later (step S33) later (steps S28 and S29). In this way, after the floor airbag 5 is deployed, the knee airbag 6 can be deployed after the occupant's toes have fully extended upward. For this reason, the freedom degree of the upward movement of a leg part can be ensured, and protection of a knee part can be aimed at, reducing the burden to a leg part.

  The deployment of the knee airbag 6 in step S33 described above is more preferably performed only when the distance between the occupant's knee and the instrument panel 4 is a predetermined value or more (step S31). . This is because if the distance between the instrument panel 4 and the knee part of the occupant is short, the knee airbag 6 is unfolded and the freedom of movement of the knee is lost, and the leg part may be damaged.

  Further, the deploying force of the floor airbag 5 and / or the knee airbag 6 is preferably adjusted according to the impact force of the collision (Steps S25, S26, S32). Accordingly, it is possible to more appropriately protect the occupant's leg according to the amount of penetration of the toe board into the vehicle compartment and the degree of burden on the occupant's leg according to the difference in impact force at the time of collision.

On the other hand, on the passenger side, which is the offset collision and the other side of the seat, as described above, the engine moves away from the passenger seat due to the offset collision, so that a vehicle body component such as a toe board approaches the seat. It will not be. Therefore, the airbag deployment control B in step S500 is basically a control process for restricting the deployment of the floor airbag 5 and the knee airbag 6 on the passenger seat side. Thereby, useless deployment of the airbag can be suppressed.
However, depending on the impact force of the collision, there is a possibility that the passenger in the passenger seat, which is the seat on the other side of the offset collision generation unit side, may be moved to the front side of the vehicle. Therefore, as shown in FIG. 6 is preferably developed (step S53).

  By the way, in the case of the right offset collision (step S242, YES), the above description has explained that the contents of the airbag deployment control differ between the driver seat side and the passenger seat side, but in the case of the left offset collision (step S242). , NO), it will be understood that the contents of the airbag deployment control described above will be interchanged between the driver seat side and the passenger seat side. That is, as shown in FIG. 6A, when it is determined in step S242 that the offset collision is a left offset collision, the offset collision generating unit side is the other side of the driver seat of step S500. The airbag deployment control B is executed, and the airbag deployment control A in step S400 is executed for the passenger seat that is the same seat as the offset collision generating unit side.

Next, the control at the time of full wrap collision in step S300, which is executed when it is determined in step S241 that it is a full lap collision, will be described.
FIG. 6D is a flowchart showing the content of the control at the time of full lap collision in step S300.
First, in step S34, an impact force is calculated based on the acceleration detected by the floor G sensor 10, and in the subsequent step S35, a larger deployment force (deployment pressure) is set as the impact force calculated in step S34 is larger. In step S36, the inflator 6a is controlled based on the deployment force (deployment pressure) set in step S35 to deploy the knee airbag 6. Note that the deployment of the floor airbag 5 is restricted at this point.

In a succeeding step S37, it is determined whether or not the delay timer T has been counted up to a predetermined value. That is, after the knee airbag 6 is deployed, it is determined whether or not a period of time has elapsed in which the occupant's leg has fully extended downward and the leg is located at a certain position.
If NO is determined in step S37, the process proceeds to step S38, the delay timer T is counted up, the process returns to step S37 again, and this loop is repeated until the delay timer T reaches a predetermined value.

When it is determined YES in step S37, that is, when it is determined that the leg portion of the occupant extends downward and the position of the leg portion is determined at a certain position after the knee airbag 6 is deployed, the process proceeds to step S39. A detection signal detected by the dash panel retraction amount detection sensor 13 is read.
In step S40, it is determined whether or not the toe board is being retracted based on the read back amount of the dash panel.
When it is determined YES in step S40, that is, when it is determined that the toe board is moving backward, the toe board may move backward even if it is a full lap collision, and the toe board may be burdened. Therefore, the process proceeds to step S41.
In step S41, a larger deploying force (deploying pressure) is set as the impact force calculated in step S34 is larger. In step S42, the inflator 5a is controlled based on the set deploying force (deploying pressure), and the driver's seat is set. The side airbags 5 and the passenger seat side airbags 5 are deployed.
When it is determined NO in step S40, the floor airbag 5 is prohibited from being deployed by exiting the full-lap collision control process.

Therefore, according to the second embodiment, as shown in FIGS. 7 (1) and 7 (b), immediately after the offset collision, only the floor airbag 5 on the driver's seat side, which is the same side as the offset collision generating unit side, is first deployed. Therefore, the freedom degree of the upward movement of the leg portion can be ensured, and the foot tip can be protected while reducing the burden on the leg portion.
Further, after the offset collision, when the occupant's leg is fully extended upward and the leg is positioned (after a predetermined time delay), the distance between the occupant's knee and the instrument panel 4 is predetermined. As shown in FIGS. 7 (1) (c), 9 (B) (1) (a), when there is no fear that the knee part of the occupant will be fixed even if the knee airbag 6 is deployed. Since the knee airbag 6 is deployed, the degree of freedom of upward movement of the legs can be secured, and the knee can be protected while reducing the burden on the legs.
Alternatively, in the case of an offset collision, even if the initial impact force at the time of the collision is small, it may increase thereafter, so the detection of the impact force is continued after the collision is detected, and after the collision is detected, the impact force reaches a predetermined value. When exceeded, the knee airbag 6 may be deployed, and the knee airbag 6 may be deployed after a predetermined time delay after the deployment of the floor airbag 5.
Further, after the offset collision, when the occupant's leg is fully extended upward and the leg is positioned (after a predetermined time delay), the distance between the occupant's knee and the instrument panel 4 is predetermined. When the knee airbag 6 is deployed and there is a possibility of fixing the occupant's knee, as shown in FIGS. 7 (1) (d), 9 (B) (1) (b), Deployment of the knee airbag 6 is prohibited.

  On the other hand, if the impact force of the collision is less than a predetermined value on the passenger seat side, which is the other side from the offset collision occurrence side, as shown in FIGS. 9B, 9B, and 9B, the floor air Deployment of both the bag 5 and the knee airbag 6 is restricted. In the case of offset collision, even if the initial impact force at the time of the collision is small, it may increase after that, so the detection of the impact force is continued even after the collision is detected, and after the collision is detected, the impact force reaches a predetermined value. When exceeded, the knee airbag 6 may be deployed. On the other hand, when the impact force of the collision is greater than or equal to a predetermined value, the knee airbag 6 is deployed as shown in FIGS. 7 (2) (b), 9 (B) (2) (a). Is called. At this time, since the deployment of the floor airbag 5 is restricted, the degree of freedom of movement of the leg portion downward is ensured, and the leg portion can be protected while reducing the burden on the leg portion.

Further, according to the second embodiment, as shown in FIG. 8, immediately after the full wrap collision, only the knee airbag 6 is first deployed, so that the freedom of movement of the legs downward is ensured. It is possible to protect the knee while reducing the burden on the leg.
Also, after the full lap collision, when the occupant's legs are fully extended downward and the legs are in a certain position (after a predetermined time delay), it is presumed that the toe board has been retreated. When there is a concern about the damage to the toes, as shown in FIGS. 8 (c), 9 (A) and 9 (a), the floor airbag 5 is deployed. The degree of freedom can be ensured, and the toes can be protected while reducing the burden on the legs.
In addition, after the full lap collision, when the occupant's legs are fully extended downward and the legs are in a certain position (after a predetermined time delay), it is presumed that the toe board retreat is converged. When there is no concern about damage to the toes, deployment of the floor airbag 5 is prohibited as shown in FIGS. 8 (d), 9 (A), and 9 (b).

  In the second embodiment, at the time of offset collision, when a predetermined time elapses after the floor airbag 5 is deployed, the knee airbag 6 is used only when the distance between the occupant's knee and the instrument panel 4 can be secured to a predetermined value or more. Although an example of deployment has been shown, the deployment force (deployment pressure) is made smaller than usual so that the degree of freedom of the occupant's legs can be secured to some extent, and the distance between the occupant's knee and the instrument panel 4 is Regardless, the knee airbag 6 may be deployed.

  In the second embodiment, an example in which the floor airbag 5 is deployed only when the toe board is continuously retracted when a predetermined time elapses after deployment of the knee airbag 5 at the time of a full lap collision is shown. The floor airbag 5 may be deployed regardless of whether or not the toeboard is being retracted after the deployment force (deployment pressure) is made smaller than usual so that a certain degree of freedom can be secured.

  In the second embodiment, an example is shown in which it is detected based on the dash panel retraction amount detected by the dash panel retraction amount detection sensor 13 for determining whether or not the toe board is retreating. It may be determined whether or not the impact force detected by the floor G sensor 10 is greater than or equal to a predetermined value, and the toe board retreat is indirectly detected.

1 is an overall configuration diagram relating to an embodiment of the present invention. The control block diagram regarding embodiment of this invention. The deployment control flowchart of the inflator 5a of the floor airbag 5 and the inflator 6a of the knee airbag 6 regarding Embodiment 1 of this invention. The figure which shows the airbag deployment state regarding Embodiment 1 of this invention. The time chart which shows the deployment state of each airbag regarding Embodiment 1 of this invention. , , , The deployment control flowchart of the inflator 5a of the floor airbag 5 and the inflator 6a of the knee airbag 6 regarding Embodiment 2 of this invention. The figure which shows the airbag deployment state at the time of the offset collision regarding Embodiment 2 of this invention. The figure which shows the airbag deployment state at the time of the full wrap collision regarding Embodiment 2 of this invention. The time chart which shows the deployment state of each airbag regarding Embodiment 2 of this invention. Explanatory drawing explaining the conventional problem.

Explanation of symbols

1: Vehicle 4: Instrument panel 5: Floor airbag 6: Knee airbag 7: Knee distance detection sensor (knee distance detection means)
8: Right front G sensor 9: Left front G sensor 10: Floor G sensor 11: Dash panel 13: Dash panel retraction amount detection sensor 50: Control unit (airbag control means)

Claims (8)

A vehicle occupant protection device that protects an occupant's legs in a collision from the front of the vehicle,
An engine room arranged in front of the vehicle;
A floor airbag that is provided on a toe board at the rear of the engine room and protects a toe portion of an occupant;
A knee airbag that is provided below the instrument panel on the vehicle interior side and protects the knee of the occupant;
Collision type determination means for determining whether the collision is a full lap collision or an offset collision;
When the collision is a full wrap collision, the knee airbag is deployed while restricting the deployment of the floor airbag, and when the collision is an offset collision, the deployment of the knee airbag is regulated. Airbag control means for deploying the bag;
An occupant protection device for a vehicle, comprising: When the collision is an offset collision, further comprising a left and right offset collision determination means for determining whether the offset collision is a right offset collision or a left offset collision,
When the collision is an offset collision, the airbag control means regulates the deployment of the knee airbag of the seat on the same side as the offset collision generation part side determined by the left and right offset collision determination means, The vehicle occupant protection device according to claim 1, wherein the floor airbag of the seat is deployed.   The airbag control means further expands the knee airbag of the seat on the other side of the offset collision generation unit side determined by the left and right offset collision determination means and restricts the deployment of the floor airbag of the other seat. The vehicle occupant protection device according to claim 2.   When the knee airbag is deployed in response to the collision being determined to be a full lap collision by the collision mode determining means, the airbag control means, after a predetermined delay time has elapsed since the deployment of the knee airbag The vehicle occupant protection device according to any one of claims 1 to 3, wherein the floor airbag is further deployed.   In the case where the floor airbag is deployed in response to the collision being determined as an offset collision by the collision mode determining means, the airbag control means, after a predetermined delay time has elapsed since the deployment of the floor airbag The vehicle occupant protection device according to any one of claims 1 to 3, wherein the knee airbag is further deployed. A knee distance detecting means for detecting a distance between the instrument panel and the knee of the occupant;
The airbag control means regulates the deployment of the knee airbag when the detected distance by the knee distance detection means becomes a predetermined value or less when the collision is an offset collision. The vehicle occupant protection device described in 1.   The vehicle according to any one of claims 1 to 6, wherein the airbag control means further adjusts a deployment force of the floor airbag and / or knee airbag according to an impact force at the time of a collision. Occupant protection device.   6. The vehicle occupant protection device according to claim 4 or 5, wherein the airbag control means further adjusts the delay time according to an impact force at the time of a collision.

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