JP3317160B2 - Vehicle impact mitigation device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle impact mitigation device suitable for use in an automobile.

[0002]

2. Description of the Related Art A vehicle such as an automobile is provided with a bumper as a device (impact mitigation device) capable of reducing an impact at the time of a collision. Such a bumper (impact mitigation device)
Is generally intended to protect a vehicle and its occupants during a collision. On the other hand, in recent years, there has been a demand for the development of a vehicle structure that takes into account not only the protection of passengers but also the protection of pedestrians, and among them, it is possible to reduce injuries when a pedestrian collides with a running vehicle. Bumper (impact mitigation device)
There is also a demand for development.

[0003] By the way, when a vehicle collides with an object or another vehicle, the bumper mounted on the vehicle absorbs the collision energy by deformation, thereby reducing the impact force acting on the vehicle and the occupants of the vehicle. However, for this purpose, it is necessary to provide required rigidity and strength. However, if the rigidity and strength of the bumper are high, the impact on a pedestrian or the like when a pedestrian or the like collides is large. Of course, if the bumper is made to be soft with little effect on pedestrians and the like, the influence on pedestrians and the like can be reduced. However, if the bumper is always soft, it will not function sufficiently as a bumper.

Meanwhile, as a bumper having a high shock absorbing performance, a shock absorbing bumper as shown in FIG. 7 has been developed. The bumper is mounted on the vehicle body 100 so as to support the bumper 102 via the shock absorber 101, so that the shock can be absorbed by the shock absorbing action of the shock absorber 101. That is, when the impact force F is applied to the bumper 102, the rod 103 is driven rearward and the shock absorber 101 contracts. ), The damping force due to the oil flow resistance is exerted, and the impact on the bumper 102 is reduced.

In Japanese Utility Model Laid-Open Publication No. 4-48442 and Japanese Utility Model Laid-Open Publication No. 1-77153, there is disclosed a technique for improving the damping characteristic of the above-described shock absorber in absorbing shock. This is a technique similar to the above-described shock absorber.

[0006]

However, the conventional shock absorbing bumper as described above is designed to protect the occupants and the body of the vehicle at the time of a collision, and particularly to protect pedestrians and the like. Not something. That is, when a vehicle collides with an object or another vehicle, the impact energy is generally large, and considering that the stroke of the shock absorber 101 is limited, the shock absorber 10
Unless the elastic force and damping force exerted by 1 are set to be large to some extent, it is not possible to sufficiently absorb shock within a desired vehicle speed region. Therefore, in the conventional shock absorbing bumper, the elastic force and the damping force of the shock absorber 101 are set to a certain level. Therefore, the elasticity and damping force of the bumper are too high to protect pedestrians and the like.

In view of this, it is conceivable to apply a variable damper, which has recently been put into practical use as a vehicle suspension, to the shock absorber 101 of the bumper. That is, when the pedestrian approaches the vehicle, the damping force of the variable damper is reduced to soften the bumper. However, if the damping force of the variable damper is reduced after the impact input, the response is delayed, and it is impossible to absorb a desired impact force.

Japanese Patent Application Laid-Open No. Hei 6-144132 discloses that a liquid is jetted toward an obstacle before the obstacle collides with the vehicle to attenuate the traveling speed of the vehicle and reduce the impact at the time of the collision. A vehicle impact mitigation device that reduces damage to occupants is disclosed. However, this device detects a distance to an obstacle by a distance sensor and operates when the obstacle approaches a predetermined distance.However, the device does not consider a pedestrian as an object and is intended to protect the pedestrian. It is not preferable as a shock absorbing device.

Japanese Patent Application Laid-Open No. 4-154457 discloses an energy absorbing bumper for buffering a collision with a pedestrian. However, the position of the load acting on the pedestrian at the time of the collision is deviated downward. In order to reduce the damage to pedestrians, the buffering effect is limited and a large buffering effect cannot be expected, and it is not possible to sufficiently protect the pedestrian.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and enables a passenger or a vehicle to be protected at all times against a collision with an object or another vehicle, while reliably protecting against a pedestrian during a collision with a pedestrian. It is an object of the present invention to provide a vehicle impact mitigation device capable of protecting a vehicle.

[0011]

According to a first aspect of the present invention, there is provided a shock absorbing device for a vehicle, comprising: a bumper supported on a vehicle body frame at a front end or a rear end of the vehicle; A shock absorbing damper interposed between the frame and
A damping force variable mechanism capable of changing the damping force of the shock absorbing damper; a human body detecting means installed near the bumper or the bumper for detecting the presence of a human body in front of the bumper; Control means for controlling the damping force to be weakened through the damping force variable mechanism based on the information, and when the human body detecting means detects the presence of a human body,
The case where the human body detecting means does not detect the presence of a human body
It is characterized by weakening the damping force .

According to a second aspect of the present invention, in the vehicle impact reducing apparatus according to the first aspect, the damping force variable mechanism includes an inner cylinder in a fluid cylinder device that supports the bumper in a direction of reducing the impact. Is characterized by being constituted by a variable orifice provided in the. Claim 3
The impact mitigation device for a vehicle according to the present invention is described in claim 1 or 2.
The apparatus according to claim 1, further comprising a vehicle speed detecting unit configured to detect a vehicle speed of the vehicle, wherein the control unit detects information from the human body detecting unit when the vehicle speed is equal to or less than a predetermined value based on detection information from the vehicle speed detecting unit. Is controlled so as to weaken the damping force based on

According to a fourth aspect of the present invention, there is provided a vehicle impact mitigation apparatus according to any one of the first to third aspects.
The human body detecting means is characterized by comprising presence detecting means for detecting the presence of the human body and position detecting means for detecting a relative position of the human body with respect to the vehicle.

[0014]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view showing an embodiment of the present invention; FIG.
As shown in FIGS. 1 to 3, a bumper 3 is supported on a vehicle body frame 2 at a front end of a vehicle body 1 of the vehicle. This bumper 3 is a bumper reinforcement (bumper frame) 3
A is used as a base material, and the surface is covered with a bumper facer 3B. The bumper reinforcement 3A is connected to the vehicle body frame 2. A shock absorbing damper (shock absorber) 4 as shown in FIGS. 3, 5, and 6 is interposed between the bumper 3 and the body frame 2. As shown in FIGS. 5 and 6, the shock absorbing damper 4 includes a damping force variable mechanism 5 that can change the damping force.

On the other hand, in the bumper 3 or in the vicinity of the bumper 3,
An infrared camera 6A and an infrared sensor 6B constituting the human body detecting means 6 are provided. The infrared camera 6A functions as presence detecting means for detecting the presence of a human body in front of the bumper 3, and the infrared sensor 6B It functions as position detecting means for detecting the relative position of the human body. That is, the infrared camera 6A can detect the heat generated by the object in front of the bumper 3 that has been photographed. By photographing the area in front of the bumper 3, the infrared camera 6A can detect the object existing in front of the bumper 3 and generate heat. (Temperature state) can be detected. The image information and the heat generation information (temperature information) obtained by the infrared camera 6A are input to the controller 7.

The infrared sensor 6B can detect the distance to the object by emitting infrared light to the object and capturing the reflection of the light, and emits infrared light to the front of the bumper 3 to allow the vehicle ( The distance from the bumper 3) to the object in front of the bumper 3) can be detected. In particular, here, a plurality of infrared sensors 6B cooperate while sharing the area in front of the bumper 3 and cooperate with the presence information (information including the size of the object) and the position information (the information including the size of the object) of the object in front of the bumper 3. (Distance information from the infrared sensor 6B), and a detection signal from each infrared sensor 6B is input to the controller 7.

The controller 7 determines from the image information and the temperature information from the infrared camera 6A whether or not there is a thing like a human body in front of the bumper 3, and the presence information and the presence information on the forward object from the plurality of infrared sensors 6B. The presence of the object in front, the size of the object, and the distance to the object are grasped from the position information, and the information from the infrared camera 6A and the information from the infrared sensor 6B are integrated, so that the human body is in front of the bumper 3. A function (human body determining means) 6C for estimating the presence or absence and the distance to the human body when present is provided.

That is, since the infrared camera 6A can capture the heat of the opposing object, the human body determination means 6C of the controller 7 can determine whether or not it is a human body based on the state of heat. this is,
The human body emits infrared rays in a specific range of frequencies due to the heat, and it is possible to determine whether or not the subject is a human body based on the presence or absence of the infrared rays.

There are other types of animals other than the human body, such as animals, which have heat. The human body determining means 6C distinguishes them from the human body by using image information from the infrared camera 6A, that is, the approximate shape of a human body. And the recognition of the size of the object by the infrared sensor 6B. The infrared camera 6A, the infrared sensor 6B and the human body determining means 6C constitute the human body detecting means 6.

Further, the controller 7 is provided with a function (ie, control means) 7A for controlling the damping force variable mechanism 5. Further, the vehicle is provided with vehicle speed detecting means 8 for detecting the vehicle speed of the vehicle.
And the vehicle speed information detected by the vehicle speed detecting means 8 are input to the control means 7A.

In the control means 7A, in the vehicle speed range where the vehicle speed is determined to be equal to or less than the predetermined value from the information from the vehicle speed detecting means 8,
If the human body detecting means 6 determines that the opposing object is a human body, the damping force of the shock absorbing damper 4 is reduced by controlling the damping force variable mechanism 5 so that the impact of the human body on the bumper 3 is reduced. To relax. In particular, the reason why the damping force variable mechanism 5 is controlled to the damping force decreasing side as described above is as follows.
As shown in FIG. 1, the operation is performed when the human body 20 enters the virtual area 19 in front of the bumper 3. The virtual area 19 is referred to as a virtual bumper because the virtual area 19 assumes a virtual bumper surface a predetermined distance ahead of the surface of the bumper 3.

That is, a virtual bumper 19 is provided in front of the actual surface of the bumper 3 by a predetermined distance, and when the human body 20 collides with the virtual bumper 19, the damping force of the shock absorbing damper 4 is weakened, so that the shock input is reduced. The damping force of the bumper 3 can be reduced without delay before being applied, and the impact on the human body can be reliably reduced.

The control in the vehicle speed range where the vehicle speed is determined to be equal to or lower than the predetermined value (in the middle and low vehicle speed range) is performed by reducing the damping force of the shock absorbing damper 4 to reduce the damping effect on pedestrians. This is because it cannot be expected at the time of running, and at the time of high-speed running, the reduction of the damping force of the shock absorbing damper 4 is considered to be rather disadvantageous in protecting the occupants of the host vehicle. Therefore, such speed limitation can be unnecessary unless a buffering effect for pedestrians is obtained even during high-speed running, or if it is not disadvantageous to protect the occupants of the host vehicle.

The shock absorbing damper 4 has a fluid cylinder 9 for supporting the bumper 3 in the direction of reducing the impact, as shown in FIG. Palinforcement 3A is bound. Reference numeral 10A denotes a coupling flange provided at the tip of the piston rod 10.

The fluid cylinder 9 includes an inner cylinder 14 and an outer cylinder 1 surrounding the inner cylinder 14.
5, a piston 11 connected to a piston rod 10 is an inner cylinder 1
4 so that you can move in and out. A spring 12 is interposed in front of the piston 11 in the inner cylinder 14, and a fluid chamber 13 is formed behind the piston 11 in the inner cylinder 14.

The spring 12 has a front end locked to the front inner end wall of the inner cylinder 14 and a rear end locked to the end surface of the piston 11 on the piston rod 10 side. The front and rear positions of the bumper 3 are positioned while being held at a required position. And
When the bumper 3 receives an impact from the front, the piston rod 1
The piston 11 retreats backward (to the right in FIG. 5) while allowing the zero to enter the inner cylinder 14, and the spring 12 expands, and according to the amount of expansion (ie, the stroke of the piston 11). Thus, it is configured to oppose the movement of the piston 11, that is, to exert a biasing force directed rearward (to the left in FIG. 5).

As described above, since the elastic reaction force against the impact of the bumper 3 is exerted by the extension of the spring 12, the amount of extension of the spring 12 is sufficiently ensured, and The retracting stroke is also sufficiently secured. As shown in FIG. 6, an orifice 16 communicating between the inside and outside of the fluid chamber 13 is interposed at the rear end of the inner cylinder. And the fluid chamber 13
The inside is filled with a viscous fluid such as oil, and the bumper 3
When the piston 11 retreats to the right in FIG. 5 due to an impact from the front, the volume of the fluid chamber 13 is reduced, so that the viscous fluid in the fluid chamber 13 is outside the fluid chamber 13 from the orifice 16, ie, It flows out into the space 17 between the outer cylinder 15.

The communication passage 18 communicating between the fluid chamber 13 and the space 17 and having the orifice 16 interposed therebetween is connected to the fluid chamber 1.
3, the space 1 in which the communication passage 18 is opened.
Since the viscous fluid is housed in the lower part of 7, the air does not enter the fluid chamber 13 from the communication passage 18. The orifice 16 is configured as a variable orifice having a variable flow path cross-sectional area. That is, as shown in FIG. 6, the variable orifice 16 includes a spool 16A disposed so as to partially block the communication path 18 and the spool 1A.
A solenoid 16B for driving the 6A forward and backward is provided. In addition, 16C is a harness for energizing the solenoid 16B.

If the solenoid 16B is not energized, the spool 16A will be in the forward position as shown in FIG. 6 (the position to the left in FIG. 6), and the normal diameter portion of the spool 16A (beyond the tip portion). When the solenoid 16B is energized, the spool 16A retreats (moves to the right in FIG. 6) when the large-diameter portion is positioned on the communication passage 18 to reduce the cross-sectional area of the flow passage. Then, the tapered portion 16a at the leading end of the spool 16A is positioned above the communication passage 18, so that the cross-sectional area of the flow passage is enlarged.

That is, in the damping force variable mechanism 5, the damping force can be changed by controlling the power supply to the solenoid 16B. For example, when the power is supplied to the solenoid 16B, the damping force is reduced and the power supply to the solenoid 16B is stopped. If it does, the damping force will increase (return to the original). Therefore, in the control means 7A, the power supply to the solenoid 16B is normally stopped so that the shock absorbing damper 4 exerts a required damping force, while the control means 7A is based on information from the human body detecting means 6 and the vehicle speed detecting means 8. When the vehicle speed is equal to or less than the predetermined value and the human body 20 enters the area of the virtual bumper 19, the solenoid 16B is energized to reduce the damping force of the shock absorbing damper 4.

In FIG. 5, reference numeral 21 denotes a dust cover,
Reference numeral 22 denotes an O-ring. In FIG. 6, reference numeral 23 denotes a spring, reference numeral 24 denotes a ball, and reference numeral 25 denotes a flow path. The ball 24 is normally urged by the spring 23 to close the flow path 25. When the internal pressure in the fluid chamber 13 increases, the spring 2
3, the ball 24 is driven against the urging force to open the flow path 25, and the viscous fluid in the fluid chamber 13 also flows out of the flow path 25 to the space 17 side. The viscous fluid can be discharged.

Since the impact mitigation device for a vehicle according to one embodiment of the present invention is configured as described above, at the front end of the vehicle, based on information detected by the human body detecting means 6 and the vehicle speed detecting means 8, When a human body enters the virtual bumper 19 imagined in front of the bumper 3, control is performed so that the damping force of the shock absorbing damper 4 is weakened. That is, the infrared camera 6A captures an image of the front of the bumper 3 to detect the presence of an object in front of the bumper 3 and the heat generation state (temperature state) of the object. Then, image information and heat generation information (temperature information) obtained by the infrared camera 6A
Is input to the controller 7.

Further, the infrared sensor 6B emits infrared light to an object in front of the bumper 3, thereby detecting the distance from the bumper 3 to the object in front of the bumper. In addition, the plurality of infrared sensors 6B detect the distance to the object ahead in each of the detection areas, and thereby position information on the object ahead of the bumper 3 (distance information between the bumper 3 and the object).
In addition the presence information (information including also the size of the object) is obtained, is also input to the controller 7 such information.

In the human body determination means 6C of the controller 7,
These infrared cameras 6A and a plurality of infrared sensors 6B
It is determined based on the information from the user whether or not a human body is present in front of the bumper 3. If a human body is present, the virtual bumper 19 is assumed to be a predetermined distance ahead of the actual surface of the bumper 3. It is determined whether or not the human body 20 has entered the vehicle.
Sent to A.

On the other hand, the vehicle speed detecting means 8 detects the vehicle speed of the vehicle, and the detection result is sent to the control means 7A of the controller 7. In the control means 7A, the human body detecting means 6 places the human body 2 in the virtual bumper 19 in the vehicle speed region where the vehicle speed is determined to be equal to or less than the predetermined value from the information from the vehicle speed detecting means 8.
If it is determined that 0 has entered, the damping force of the shock absorbing damper 4 is weakened by controlling the damping force variable mechanism 5 so as to reduce the shock at the time of the collision of the human body with the bumper 3.

That is, in the control means 7A, the solenoid 16B of the damping force variable mechanism 5, which has been normally stopped to be energized, is energized to widen the opening area of the variable orifice 16 and weaken the damping force of the shock absorbing damper 4. Control. As a result, after the human body 20 enters the virtual bumper 19, as shown in FIG.
At this time, the bumper 3 already has a soft cushioning characteristic in which the damping force of the shock absorbing damper 4 is weakened.
And the damping force of the shock-absorbing damper 4 is significantly reduced as compared with the case where the bumper 3 collides with the normal case.

As a result, there is an advantage that the damage to the human body 20 is reduced and, for example, a place where a serious injury is caused by a slight injury and a possibility of avoiding an injury are increased. When the human body 20 is detected by the virtual bumper 19 (when the human body 20 enters the virtual bumper 19), the airbag may be opened or the bumper 3 may be opened.
It is also possible to provide more pedestrian protection by switching the performance of the vehicle or by lifting the hood and decelerating the vehicle.

By the way, when the vehicle collides with something other than the human body 20, the power supply to the solenoid 16B of the damping force variable mechanism 5 is stopped, and the damping force of the shock absorbing damper 4 is increased to a normal state. The opening area is kept narrow, and the shock absorbing damper 4 is kept in a state of high damping force and a firm cushioning characteristic. As a result, the bumper 3 is sufficiently supported by the body frame 2 via the shock absorbing damper 4, and protects the occupant of the host vehicle, the host vehicle, the occupant of the other vehicle, and the other vehicle in the event of a collision with an object or another vehicle. The normal function of the bumper 3 is secured.

The human body detecting means 6 is not limited to the above-described configuration. For example, a pyroelectric sensor may be provided in place of the infrared camera, and the human body temperature may be detected by the pyroelectric sensor. Good. The configurations of the shock absorbing damper 4 and the damping force variable mechanism 5 are not limited to those described in the above-described embodiment.

In the present embodiment, the case where the vehicle impact mitigation device according to the present invention is applied to a front bumper provided at the front end of the vehicle body 1 has been described. It may be applied to a rear bumper provided in a section.

[0041]

As described above in detail, according to the vehicle impact mitigation apparatus of the present invention, the collision between the vehicle and the human body can be detected before the collision, and the impact input at the time of the collision can be detected. By controlling the damping force of the shock absorbing damper to weaken in advance, there is an advantage that the impact on the human body can be reduced.

According to the second aspect of the present invention, it is possible to reliably control the damping force of the shock absorbing damper at the time of collision with a human body. According to the vehicle impact mitigation device of the present invention, the control is performed within the speed range in which the damping force control of the shock absorbing damper can provide a cushioning effect for pedestrians. In addition, since the damping force of the shock absorbing damper is not weakened during high-speed running, the first purpose of the impact mitigation device that protects the occupant of the host vehicle during high-speed running is secured. You.

According to the vehicle impact mitigation apparatus of the present invention, the presence of the human body is reliably detected by the presence detecting means for detecting the presence of the human body and the position detecting means for detecting the relative position of the human body to the vehicle. There is an advantage that a pedestrian can be protected with a simple configuration.

[Brief description of the drawings]

FIG. 1 is a schematic longitudinal sectional view showing a main part of a vehicle impact mitigation apparatus as one embodiment of the present invention.

FIG. 2 is a schematic diagram showing a mounting state of a vehicle impact mitigation device as one embodiment of the present invention.

FIG. 3 is a schematic diagram showing a principle configuration of a vehicle impact mitigation device as one embodiment of the present invention.

FIG. 4 is a schematic control block diagram of the vehicle impact mitigation apparatus as one embodiment of the present invention.

FIG. 5 is a schematic longitudinal sectional view showing an internal structure of a damper of the vehicle impact mitigation apparatus as one embodiment of the present invention.

FIG. 6 is a schematic longitudinal sectional view showing a detailed structure of a rear end portion of a damper of the vehicle impact mitigation device as one embodiment of the present invention.

FIG. 7 is a schematic perspective view showing a conventional vehicle impact mitigation device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Body 2 Body frame 3 Bumper 3A Bumper reinforcement (Bumper frame) 3B Bumper facer 4 Shock absorption damper (Shock absorber) 5 Damping force variable mechanism 6 Human body detecting means 6A Infrared camera as presence detecting means 6B Position detecting means Infrared sensor 7 Controller 6C Human body determination means 7A Control means 8 Vehicle speed detection means 9 Fluid cylinder 10 Piston rod 10A Coupling flange part 11 Piston 12 Spring 13 Fluid chamber 14 Inner cylinder 15 Outer cylinder 16 Variable orifice 16B Solenoid 16C Harness 16a Spool 16A Tapered portion at the tip 17 Space 18 Communication passage 19A Spool 19 Virtual bumper (virtual area in front of bumper 3) 20 Human body 21 Dust cover 22 O-ring 23 Pulling 24 Ball 25 Flow path

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification code FI B60R 21/34 692 B60R 21/34 692 (72) Inventor Takahiro Maemura 33-3-8 Shiba 5-chome, Minato-ku, Tokyo Mitsubishi Motors Inside the Industrial Co., Ltd. (72) Inventor Norio Inoue 5-33-8 Shiba, Minato-ku, Tokyo Mitsubishi Motors Corporation (72) Inventor Misuzu Yamamoto 5-33-8 Shiba, Minato-ku, Tokyo Mitsubishi Motors (56) References JP-A-2-95950 (JP, A) JP-A-4-46814 (JP, A) JP-A-4-154457 (JP, A) JP-A-6-144132 (JP) JP-A-60-99739 (JP, A) JP-A-4-48442 (JP, U) JP-A-1-77153 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB B60R 19/48 B60R 19/28 B60R 19/32 B60R 21/34 691 B60R 21/34 692

Claims (4)

(57) [Claims] 1. A bumper supported on a vehicle body frame at a front end or a rear end of a vehicle, a shock absorbing damper interposed between the bumper and the vehicle body frame, and a damping force of the shock absorbing damper. A damping force variable mechanism that can be changed; a human body detecting means that is installed near the bumper or near the bumper and detects the presence of a human body in front of the bumper; and the damping force variable based on information from the human body detecting means. and a control means for controlling the damping force through mechanism, when the person body detection means detects the presence of the human body, the person
The attenuation is smaller than when the body detection means does not detect the presence of a human body.
A vehicle impact mitigation device characterized by weakening the force . Wherein said damping force control mechanism, In'nashiri in the fluid cylinder device for supporting the bumper on the shock easing
2. The impact mitigation device for a vehicle according to claim 1, wherein the impact mitigation device comprises a variable orifice provided in the cylinder . 3. A vehicle speed detecting means for detecting a vehicle speed of the vehicle, wherein the control means detects information from the human body detecting means when the vehicle speed is lower than a predetermined value based on detection information from the vehicle speed detecting means. 3. The impact mitigation device for a vehicle according to claim 1, wherein the damping force is controlled to be weakened based on the following equation. 4. The human body detecting means comprises: a presence detecting means for detecting the presence of the human body; and a position detecting means for detecting a relative position of the human body with respect to the vehicle. Item 4. The impact relaxation device for a vehicle according to any one of Items 1 to 3.