JP2000255350A - Front car body structure of vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To efficiently relieve impact by bringing down an obstacle onto a hood at collision time by projecting a movable member up to a second position in front of and lower than the tip position from a first position in the rear of a vehicle lengthwise directional tip position of a bumper when detecting or anticipating a collision with the obstacle. SOLUTION: An arm 5 projecting while rotating up to a position (a second position) in the rear of a tangent connecting the edge on the tip of a hood 8 and a tip position of a bumper 6 in front of and lower than the tip position from a normal time housing position (a first position) in the rear of a vehicle lengthwise directional tip position of the bumper 6, is rotated by a driving mechanism composed of a piston mechanism 9, a rack 10 of the tip part and a pinion 11 on the basis of a signal from a collision detecting sensor 2. Thus, since an obstacle and the arm 5 contact with each other in the first place at collision time to the obstacle, the obstacle can be reliably brought down on the hood 8 more than when contacting with the bumper 6 in the first place to thereby relieve impact applied to the obstacle.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a front body structure of a vehicle, for example, to a front body structure of a typical automobile.

[0002]

2. Description of the Related Art There have been proposed many protection mechanisms provided on a vehicle such as an automobile for reducing the impact of the vehicle upon an obstacle at the time of collision.

As such a protection mechanism, for example, Japanese Utility Model Laid-Open No. 57-101653 proposes a protection mechanism having a movable member that projects forward of a vehicle when a collision occurs with a pedestrian.

Japanese Patent Application Laid-Open No. 6-144154 proposes a protection mechanism having an airbag projecting forward from a bumper when a collision with a pedestrian occurs.

[0005]

However, the protection mechanism proposed in Japanese Utility Model Laid-Open No. 57-101653 is intended for vehicles such as trucks without a hood.
By dropping obstacles on the bonnet at the time of collision,
The impact applied to the obstacle cannot be reduced.

[0006] The protection mechanism proposed in Japanese Patent Application Laid-Open No. 6-144154 not only provides the impact of the vehicle at the time of collision,
It is also expected that the obstacle will be bounced off by the deployment force of the airbag or the reaction force generated at the moment of contact with the deployed airbag.

Accordingly, the present invention provides a front vehicle body structure for a vehicle which, when a collision with an obstacle is made, falls down on the hood more reliably, thereby effectively reducing the impact applied to the obstacle. Aim.

[0008]

In order to achieve the above object, a front body structure of a vehicle according to the present invention has the following features.

That is, a front body structure of a vehicle having a bumper on a hood in front of a vehicle compartment, wherein a first position behind a front end position of the bumper in a vehicle longitudinal direction and a first front position below and below the front end position thereof. A movable member capable of projecting to the second position, and a drive mechanism for projecting the movable member from the first position to the second position when a collision with an obstacle is detected or predicted. I do.

Further, for example, the second position is the first position.
At a position obliquely above the vehicle in the vehicle longitudinal direction, or at a position rearward of a tangent line connecting the edge of the tip of the bonnet and the tip of the bumper.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A front body structure of a vehicle according to the present invention will be described below in detail with reference to the drawings as an embodiment of a typical automobile.

[First Embodiment] FIG. 1 shows a first embodiment of the present invention.
It is a conceptual diagram explaining operation | movement of the protection mechanism in embodiment, and represents the state which looked at the front part of the motor vehicle from the lateral direction. FIG. 2 is a perspective view showing a shape of a protection mechanism according to the first embodiment of the present invention (a drive mechanism described later is omitted).

In FIGS. 1 and 2, an impact detection sensor 2 embedded in a bumper 6 is a general pressure-sensitive sensor capable of detecting a collision with an obstacle. The collision prediction sensor 4 is embedded in, for example, the front edge of the hood 8 and acquires a CCD (Charge Coup) that obtains information on which a collision with an obstacle is predicted.
This is a camera such as a led device) or an ultrasonic sensor (the collision prediction sensor 4 is used in the second embodiment).

The arm 5 is supported by a rotary shaft 21 near the tip end of the frame 7 of the automobile, and is normally stored at the storage position (first position) behind the tip end of the bumper 6 in the vehicle longitudinal direction.
From the position (2) to the operating position (2nd position) forward and below the tip position. In the present embodiment, the second position is obliquely above the first position in the vehicle longitudinal direction as shown in FIG.
In addition, it is a position behind a tangent connecting the edge of the front end of the hood 8 and the front end position of the bumper 6.

Here, the reason why the tip position of the arm 5 is set to the second position will be described. Generally, an obstacle (especially, an obstacle whose height direction is longer than the lateral direction) is prevented from being bounced off by an impact at the time of a collision, and the impact applied to the obstacle is more efficiently mitigated. It is desirable that the position where the obstacle first contacts the vehicle at the moment of collision is close to the ground surface below the obstacle. Therefore, in the present embodiment, the position shown in FIG. 1 described above is set as the operating position (second position). Further, as in the present embodiment, the storage position in the normal state (first
), A so-called approach angle, which is indispensable for an automobile, is secured.

As shown in FIG. 2, the arm 5 includes a rod-like member extending in the vehicle lateral direction, and the rod-like member is made of a low-rigidity member capable of absorbing an impact (for example, a soft metal material). It is recommended to use a pipe consisting of

As shown in FIG. 2, the rotation shaft 21 is provided with a lock mechanism 20 for preventing the arm 5 from rotating again in the first position direction when the arm 5 rotates to the second position. ing. The lock mechanism 20 will be described.

FIG. 3 is a view for explaining a lock mechanism of an arm of a vehicle body front structure according to the first embodiment of the present invention.

As shown in FIG. 1, the lock mechanism 20 comprises a plurality of claws 22 provided along a rotation shaft 21 of the arm 5 and a stopper 24 movable around the rotation shaft 23. . With this mechanism, the arm 5 is rotatable in the rotation direction (clockwise) when the arm is projected, but when a force is applied in the rotation direction (counterclockwise) at the time of collision, the claw 22 and the stopper are stopped. 24 are engaged. Thus, it is possible to prevent the arm 5 from rotating in the first position direction due to the reaction force due to the collision with the obstacle.

Next, a drive mechanism for rotating the arm 5 from the first position to the second position will be described.

FIG. 4 is a view for explaining an arm drive mechanism having a front vehicle body structure of a vehicle according to a first embodiment of the present invention.

In the present embodiment, the drive mechanism of the arm 5 includes a piston mechanism 9 operable in the downward direction of the vehicle and a rack 1 provided at the tip of the piston as shown in FIG.
And a rack-and-pinion mechanism constituted by a pinion 11 provided around the rotation axis 21 of the arm 5 and the arm 5. With this drive mechanism, the arm 5 is moved from the normal state shown in FIG. 4A in response to the operation of the piston mechanism 9 by the reaction of an inflator (not shown).
The arm 5 is rotated by the rack and pinion mechanism as shown in FIG.

In the present embodiment, the piston mechanism 9 is disposed in the lower direction of the vehicle. However, the piston mechanism 9 may be disposed in parallel with the frame 7.

Next, a control mechanism for controlling the operation of the above-described drive mechanism will be described.

FIG. 8 is a block diagram showing a control mechanism of a vehicle body front structure according to a first embodiment of the present invention. An output signal from a collision detection sensor 2 is input to a microcomputer 1. The movable member 3 corresponding to the above-described driving mechanism is operated based on the signal. Here, the microcomputer 1 may be provided exclusively for the drive mechanism of the arm 5, for example, near the dashboard, or may be shared with other control units. In particular, the cost can be reduced by substituting the microcomputer 1 for the airbag control unit.

FIG. 9 is a flowchart showing a control process of the front body structure of the vehicle according to the first embodiment of the present invention. The program stored in the microcomputer 1 is stored in a CPU (not shown) in the computer. Shows the processing to be executed.

In the figure, step S1: an output value of the collision detection sensor 2 is read.

Steps S2 and S3: It is determined whether or not a collision has occurred by comparing the read output value of the collision detection sensor 2 with a predetermined threshold value. ), And in the case of YES (when a collision occurs), the movable member 3 is operated and the process returns.

As described above, according to the above-described embodiment, at the time of collision with an obstacle, the obstacle and the arm 5 first come into contact with each other at a position closer to the ground surface than the bumper 6.
The impact applied to the obstacle can be reduced more efficiently by lowering (releasing) the obstacle on the bonnet 8 more reliably than when the bumper 6 first contacts the bumper 6.

[Second Embodiment] In the present embodiment, the first
Based on the front body structure of the vehicle in the embodiment of
A different control method of the drive mechanism of the arm 5 will be described.

FIG. 10 is a block diagram showing a control mechanism for a front body structure of a vehicle according to a second embodiment of the present invention. The block diagram of FIG. And a vehicle speed V detected by a vehicle speed sensor (not shown). In the present embodiment, in addition to the control processing of the drive mechanism of the arm 5 based on the output signal of the collision detection sensor 2, a collision with an obstacle is predicted based on the output signal of the collision prediction sensor 4, and it is determined that a collision occurs. Then, the rotation of the arm 5 is started prior to the collision.

FIG. 11 is a flowchart showing a control process of a front body structure of a vehicle according to a second embodiment of the present invention. The program stored in the microcomputer 1 is stored in a CPU (not shown) in the computer. Shows the processing to be executed.

In FIG. 5, step S11: The output value of the collision detection sensor 2 and the current vehicle speed V are read.

Step S12: By comparing the read output value of the collision detection sensor 2 with a predetermined threshold value,
It is determined whether or not a collision has occurred. If NO (when there is no collision), the process proceeds to step S13, and if YES (when there is a collision), the process proceeds to step S18.

Step S13, Step S14: The output signal of the collision prediction sensor 4 is read (Step S13),
A coefficient K indicating the possibility of collision is calculated by a general method based on the read signal (step S1).
4).

Step S15: It is determined whether or not the calculated coefficient K is larger than a predetermined value Ka, and YES (K> Ka)
If so, the process proceeds to step S16, and if NO (K ≦ Ka), there is no possibility of collision, and the process returns.

Step S16: A predicted collision time T at which a collision will actually occur is calculated based on the vehicle speed V and the collision possibility coefficient K (step S16).

Steps S17 and S18: It is determined whether or not the current time is a timing that is a predetermined time TP before the calculated expected collision time T (step S17).
If NO (the time until the expected collision time T is equal to or longer than the predetermined time TP
(When it is longer), the determination of this step is repeated, and YE
In the case of S (when the time until the expected collision time T is shorter than the predetermined time TP), the movable member 3 is operated and the routine returns.

According to the present embodiment for performing such control, the arm 5 can be operated more reliably than in the first embodiment.

[Third Embodiment] In the present embodiment, the first
Based on the front body structure of the vehicle in the embodiment of
A case where a different driving method is used for the driving mechanism of the arm 5 will be described.

FIG. 5 is a view for explaining an arm drive mechanism of a front body structure of a vehicle according to a third embodiment of the present invention.

In this embodiment, the arm 5 in the normal storage position (second position) is fixed by a breakable bolt 12 having an inflator (not shown) inside as shown in FIG. When the bolt breaks as shown in FIG. 3B due to the reaction of the inflator, the arm 2 rotates counterclockwise by the reaction force of a not-shown torsion bar spring provided on the rotating shaft 21. To start.

Even when such a drive mechanism according to the present embodiment is employed, similarly to the first embodiment, at the time of collision with an obstacle, the obstacle and the arm are positioned closer to the ground surface than the bumper 6. Since the first contact with the bumper 5 is more reliable than the first contact with the bumper 6, the obstacle is more reliably dropped on the hood 8, so that the impact applied to the obstacle can be efficiently reduced. it can.

[Fourth Embodiment] In the present embodiment, the first
Based on the front body structure of the vehicle in the embodiment of
A case where a different driving method is adopted for the driving mechanism of the arm will be described.

FIG. 6 is a conceptual diagram illustrating the operation of the protection mechanism according to the fourth embodiment of the present invention. FIG.
FIG. 8 is a diagram illustrating an arm drive mechanism of a front body structure of a vehicle according to a fourth embodiment of the present invention.

6 and 7, the difference from the first embodiment is that the arm 5A (FIG. 7 a) protrudes linearly forward in the longitudinal direction of the vehicle to the position of the arm 5A (see FIG. 7B) indicated by a broken line in FIG. 6 during operation.

Even if such a driving mechanism according to the present embodiment is employed, the same effect as that of the first embodiment can be obtained.

<Modification of Fourth Embodiment> In this modification, a case will be described in which a different arm shape is adopted based on the front body structure of the vehicle in the fourth embodiment.

FIG. 12 is a perspective view illustrating a protection mechanism according to a modification of the fourth embodiment of the present invention.

The arm 5B in this embodiment constitutes the lower end of the bumper 6 in the normal storage position (first position) as shown by the solid line in FIG.
By the piston mechanism 17 described in the fourth embodiment, it protrudes to a second position indicated by a broken line in FIG.

Even if such an arm 5B according to the present embodiment is employed, the same effect as that of the first embodiment can be obtained, and the appearance can be improved.

[0052]

As described above, according to the present invention,
When the vehicle collides with an obstacle, the obstacle is more reliably dropped on the hood, thereby providing a front body structure of the vehicle that efficiently reduces the impact applied to the obstacle.

That is, according to the first aspect of the present invention, when the movable member protrudes to the second position, it collides with an obstacle,
Since the obstacle and the movable member come into contact first at a position closer to the ground surface than the bumper, the impact applied to the obstacle is efficiently mitigated by falling down the obstacle more securely on the hood. Can be.

According to the second and sixth aspects of the present invention, the original function of the movable member during operation (second position) and the approach angle of the vehicle during storage (first position) are ensured. Can be compatible.

According to the seventh and eighth aspects of the present invention, it is possible to efficiently absorb the impact on the obstacle.

According to the ninth aspect, the appearance can be improved.

According to the tenth to twelfth aspects of the present invention, the movable member can be reliably operated with a relatively simple configuration.

[Brief description of the drawings]

FIG. 1 is a conceptual diagram illustrating an operation of a protection mechanism according to a first embodiment of the present invention.

FIG. 2 is a perspective view illustrating a shape of a protection mechanism according to the first embodiment of the present invention.

FIG. 3 is a diagram illustrating a lock mechanism of an arm of a front vehicle body structure of the vehicle according to the first embodiment of the present invention.

FIG. 4 is a diagram illustrating an arm drive mechanism of a front vehicle body structure of the vehicle as the first embodiment of the present invention.

FIG. 5 is a diagram illustrating an arm drive mechanism of a front vehicle body structure of a vehicle as a third embodiment of the present invention.

FIG. 6 is a conceptual diagram illustrating an operation of a protection mechanism according to a fourth embodiment of the present invention.

FIG. 7 is a diagram illustrating an arm drive mechanism of a front body structure of a vehicle according to a fourth embodiment of the present invention.

FIG. 8 is a block diagram showing a control mechanism of a front vehicle body structure of the vehicle as the first embodiment of the present invention.

FIG. 9 is a flowchart showing control processing of a front body structure of the vehicle as the first embodiment of the present invention.

FIG. 10 is a block diagram showing a control mechanism of a front body structure of a vehicle as a second embodiment of the present invention.

FIG. 11 is a flowchart illustrating control processing of a front body structure of a vehicle according to a second embodiment of the present invention.

FIG. 12 is a perspective view illustrating a protection mechanism according to a modification of the fourth embodiment of the present invention.

[Explanation of symbols]

 1: microcomputer, 2: shock detection sensor, 3: movable member, 4: collision prediction sensor, 5, 5A, 5B: arm, 6: bumper, 7: frame, 8: bonnet, 9, 17: piston mechanism, 10 : Rack, 11: pinion, 12: breakable bolt, 20: lock mechanism, 21, 23: rotating shaft, 22: claw, 24: stopper,

Claims (12)

[Claims] 1. A front body structure of a vehicle having a bumper on a hood in front of a vehicle compartment, the vehicle body structure comprising: a first position behind a front end position of the bumper in a vehicle longitudinal direction; A movable member capable of projecting to a second position, and a drive mechanism for projecting the movable member from the first position to the second position when a collision with an obstacle is detected or predicted. The front body structure of the vehicle. 2. The front body structure of a vehicle according to claim 1, wherein the second position is obliquely above the first position in a vehicle longitudinal direction. 3. The front body structure of a vehicle according to claim 1, wherein the movable member is supported by a frame of the vehicle. 4. The front body structure of a vehicle according to claim 1, wherein the drive mechanism detects a collision with an obstacle based on an output signal of a pressure sensor embedded in the bumper. 5. The front body structure of a vehicle according to claim 1, wherein the drive mechanism predicts a collision with an obstacle based on an output signal of a collision prediction sensor provided in the vehicle. 6. The front body structure of a vehicle according to claim 1, wherein the second position is behind a tangent connecting an edge of the bonnet tip and a tip of the bumper. 7. The front body structure of a vehicle according to claim 1, wherein said movable member includes a rod-shaped member extending in a vehicle lateral direction. 8. The bar-shaped member is made of a low-rigidity member capable of absorbing a shock.
The front body structure of the vehicle as described. 9. The front body structure of a vehicle according to claim 7, wherein said rod-shaped member forms a lower end portion of said bumper at said first position. 10. The driving mechanism, comprising: an inflator that operates when detecting or predicting a collision with an obstacle; and moving the movable member from the first position to the second position when the inflator reacts. The vehicle body structure according to claim 1, further comprising: a piston mechanism configured to protrude to a maximum extent. 11. The front body structure of a vehicle according to claim 10, wherein the piston mechanism is operable forward in the longitudinal direction of the vehicle, and the movable member projects in the same direction as the operation direction. . 12. The drive mechanism further includes a rack and pinion mechanism for rotating the movable member from the first position to the second position, wherein the movable member is operated by the piston mechanism. sometimes,
The front body structure of a vehicle according to claim 10, wherein the rack and pinion mechanism protrudes while rotating.