JP2018167674A - Pedestrian collision detection apparatus - Google Patents

Abstract

To provide a pedestrian collision detection apparatus capable of further improving detection accuracy of a pressure sensor at collision in a bumper end side (a vehicular width direction) while suppressing a time lag.SOLUTION: A pedestrian collision detection apparatus includes: a bumper having a bumper reinforce member 7 extending in a vehicular width direction and a bumper face member 9 disposed on a front side of the bumper reinforce member; a flexible tube member 17 extending in the vehicular width direction and between the bumper reinforce member and bumper face member; pressure sensors 19, disposed at each end of the tube member, for detecting a pressure change within the tube member in association with collision with the bumper; and further a tube deformation suppression part 25, disposed around a tube portion at vehicular width end of the tube member, for suppressing a deformation amount of the tube portion when colliding toward vehicular width ends of the bumper.SELECTED DRAWING: Figure 2

Description

  The present invention relates to an improvement in a pedestrian collision apparatus configured by assembling a tube in a bumper of a vehicle.

  The pedestrian collision detection device has a structure in which a flexible tube, for example, a silicon tube, for example, is incorporated in a vehicle bumper as disclosed in the cited document 1. In many cases, the silicon tube extends between the bumper reinforcement member constituting the bumper and the bumper face member disposed on the front side of the bumper reinforcement member so as to extend in the vehicle width direction. And a pressure sensor is provided in the edge part (vehicle width direction end) of a silicon tube, and the collision of a pedestrian is detected from the pressure change in a silicon tube accompanying the collision with a bumper.

JP, 2006-52828, A

By the way, the output of the pressure sensor may differ depending on the bumper collision position.
For example, when a collision occurs at the center of the bumper in the vehicle width direction, the volume change occurs between the long distance between the center of the silicon tube in the vehicle width direction and the tube end where the pressure sensor is located, and the pressure in the silicon tube reflects this change. Is output from the pressure sensor. On the other hand, when a collision occurs on the bumper end side (vehicle width direction), especially near the end, the volume of the tube section changes rapidly because the position of the collision and the tube end with the pressure sensor are extremely short. It is easy to show a higher output value when a collision occurs at the end of the bumper than at other collision positions. For this reason, in the case of a collision at the end of the bumper, the output of the pressure sensor becomes saturated exceeding the upper limit value, and there is room for further improving the detection accuracy.

In Cited Document 1, in order to increase the detection accuracy, the length of the silicon tube on the bumper end side is increased from the central region in the bumper vehicle width direction. However, this causes the tube length to be excessive, and the time lag spent on pressure detection is increased. There is a difficulty that becomes excessive.
Accordingly, an object of the present invention is to provide a pedestrian collision detection device that further improves the detection accuracy of a pressure sensor at the time of a bumper end (vehicle width direction) collision while suppressing a time lag.

  An aspect of the present invention includes a bumper reinforcement member extending along a vehicle width direction, a bumper reinforcement member disposed on the front side of the bumper reinforcement member, and a bumper reinforcement member. A flexible tube member provided so as to extend in the vehicle width direction between the member and the bumper face member, and a pressure change in the tube member due to a collision with the bumper provided at each end of the tube member In the pedestrian collision detection device configured to include a pressure sensor for detecting the tube portion, the tube portion at the time of collision to the vehicle width direction end side of the bumper is around the tube portion at the vehicle width direction end portion of the tube member. It has a tube deformation suppression part which suppresses the deformation amount.

According to the present invention, when a collision load is applied to the end side (vehicle width direction) of the bumper, the deformation amount of the tube portion on the end side of the bumper is suppressed to a predetermined amount by the tube deformation suppressing portion. Thereby, a sudden and large volume change in the tube portion is suppressed, and an excessive output of the pressure sensor due to a collision at the end of the bumper is suppressed.
Therefore, it is possible to further improve the detection accuracy of the pressure sensor at the time of a collision at the bumper end side (vehicle width direction). A collision can be detected.

The perspective view which shows the pedestrian collision detection apparatus used as the aspect which concerns on one Embodiment of this invention. The plane sectional view of the pedestrian collision detection device. The sectional side view which follows the AA line in FIG. The sectional side view which follows the BB line in FIG.

Hereinafter, the present invention will be described based on an embodiment shown in FIGS.
FIG. 1 shows the entire pedestrian collision detection apparatus 1, and FIGS. 2 to 4 show cross sections of the respective parts of the apparatus 1.
In FIG. 1, reference numeral 3 denotes a vehicle body, and reference numeral 5 denotes a front bumper (hereinafter simply referred to as a bumper) installed on the front side of the vehicle body 3. The bumper 5 includes a bumper reinforcement member 7 extending in the vehicle width direction that forms the skeleton of the bumper 5, a bumper face member 9 disposed on the front side of the bumper reinforcement member 7, and the bumper reinforcement member 7. The shock absorbing member 11 is attached to the front surface portion in the vehicle width direction. The bumper reinforcement member 7 is composed of, for example, a hollow square member, the bumper face member 9 is composed of, for example, a synthetic resin panel member, and the impact absorbing member 11 is, for example, a foamed resin member (for example, a foamed polypropylene material). Consists of. Reference numeral 13 denotes a pair of vehicle body mounting legs protruding from the back of the bumper reinforcement member 7.

  As shown in FIGS. 1 and 2, the pedestrian detection device 1 is arranged on the front surface of a bumper reinforcement member 7 covered with an impact absorbing member 11 and is interposed between the bumper face member 9 and the flexible A tube member having a property, for example, a silicon tube 17 having the same cross-sectional shape, and a pressure sensor 19 attached to each end of the silicon tube 17 is configured. The silicon tube 17 extends in a straight line over the vehicle width direction of the bumper reinforcement member 7 (bumper 5). Accordingly, when a collision load is applied from the front of the bumper face member 9 due to the collision and a part of the silicon tube 17 is pressed and deformed, a signal corresponding to a pressure change in the silicon tube 17 is output from the pressure sensor 19. The The pressure sensor 19 is configured such that a collision body (not shown) that collides with the bumper 5 is connected to a control unit 21 (for example, constituted by a microcomputer) that determines the collision of a pedestrian, and an output signal (pressure value) from the pressure sensor 19. Based on the above, the pedestrian determination (detection of pedestrians) can be performed.

The pedestrian detection device 1 is provided with means for suppressing an excessive output when it collides with the end of the bumper 5. For this means, a structure in which a tube deformation suppressing portion 25 is provided around the silicon tube portion on the end side of the bumper 5 and the deformation amount of the silicon tube portion on the end side of the bumper 5 is suppressed more than other portions is used. .
For example, the tube deformation suppressing portion 25 uses a groove portion 27 provided on the front surface portion of the bumper reinforcement member 7 to support the silicon tube 17 so as to set a predetermined deformation amount of the silicon tube portion on the end side of the bumper 5. The technology to regulate is used.

  Here, the groove part 27 that supports the silicon tube 17 is formed over the entire width of the bumper reinforcement member 7 as shown in FIGS. 1 to 3. The groove portion 27 has a concave shape (here, square) corresponding to the outer diameter of the silicon tube 17. The silicon tube 17 is fitted in the groove 27. The silicon tube 17 is supported in the groove 27 via a support member 29 (shown only in FIGS. 2 and 3).

  As shown in FIGS. 1 to 3, the structure for suppressing the amount of deformation on the end side of the silicon tube 17 (tube deformation suppressing portion 25) is a groove near the end of the silicon tube 17 where the pressure sensor 19 is arranged, that is, The depth d1 (FIG. 4) of the groove part 27a into which the end-side silicon tube part 17a fits is deeper than the groove part d2 (FIG. 3) into which the other silicon tube part 17b fits. Thereby, the deformation amount of the silicon tube portion 17a near the end close to the pressure sensor 19 is set to be smaller than that of the other silicon tube portion 17b due to the restriction of the deformation amount caused by the groove shape having the depth d1. That is, the deformation amount of the silicon tube portion 17a close to the pressure sensor 19 is suppressed.

  In particular, the depth of the groove portion 27 into which the silicon tube 17 is fitted is shown in FIGS. 1 to 3 so that the pressure sensor 19 exhibits a uniform detection performance regardless of the location where the bumper 5 collides in the vehicle width direction. As shown in the drawing, the shallowest depth dimension in the bumper central region L1 on the vehicle width direction center side of the bumper 5 is set to “d2”, and the end region L2 from the bumper central region L1 end to the bumper end is The depth dimension is gradually increased as it goes to the depth, and the depth dimension is set to “L2” in this case, which is deepest in the vicinity of the end, for example, up to 60% or more of the outer diameter of the silicon tube 17. By setting the depth dimension of each part of the groove 27, when the same collision body collides with the vehicle width direction center and the vehicle width direction end side of the bumper 5 under the same situation, the output value of the pressure sensor 19 is It is made to be almost uniform.

Next, the operation of the pedestrian collision detection apparatus 1 configured as described above will be described.
For example, when a collision load is applied from the front of the vehicle to the center side of the bumper 5 (in the vehicle width direction) as shown by an arrow X in FIG. And the silicon tube part 17b located in the same part is pressed. That is, the silicon tube portion 17b on the center side (vehicle width direction) is deformed, and the pressure in the silicon tube 17 changes.

A signal corresponding to the pressure change in the silicon tube 17 is output from the pressure sensor 19. And based on the output signal (pressure value) of the pressure sensor 19, the control part 21 determines whether a collision body is a pedestrian. If it is determined that the person is a pedestrian, the airbag device is activated, or the pedestrian protection device that protects the pedestrian is activated (none of which is shown).
Further, when a collision load is applied from the front of the vehicle to the end side (the vehicle width direction) of the bumper 5 as indicated by an arrow Y in FIG. . Subsequently, the silicon tube portion 17a located in the same portion is pressed and deformed, and the pressure in the silicon tube 17 changes.

  At this time, unlike the central side of the bumper 5, the distance from the silicon tube portion (position of the arrow Y) where the impact load is applied to the position (tube end) where the pressure sensor 19 is present is extremely short. For this reason, although the collision object collides in the same manner, an extremely high output value tends to be output from the pressure sensor 19 when the collision occurs on the end side of the bumper 5. If there is, the output of the pressure sensor 19 tends to become saturated exceeding the upper limit value.

Here, the deformation amount of the silicon tube portion 17a on the end side (vehicle width direction) of the bumper 5 is regulated to a predetermined amount by a groove portion 27a (depth dimension d1) that accommodates many portions of the silicon tube 17 in advance, which is excessive. The output value is set so as not to be output.
Since the deformation of the silicon tube portion 17a is limited to only a slight cross-sectional shape portion of the silicon tube 17 protruding from the groove portion 27a, a sudden and large volume change in the silicon tube portion 17a on the end side of the bumper 5 can be suppressed. Thereby, an excessive output of the pressure sensor 19 due to a collision at the end side of the bumper 5 (silicon tube 17) is suppressed.

  As described above, since the deformation amount of the silicon tube portion 17b on the end side (vehicle width direction) of the bumper 5 is suppressed to a predetermined amount by the groove portion 27a having the depth dimension d1, which is the tube deformation suppressing portion 25, the upper limit value is reached. Can be suppressed (saturated state), and the detection accuracy on the bumper end side (vehicle width direction) of the pressure sensor 19 can be further improved.

Therefore, it is possible to determine whether the collision object is a pedestrian based on the output of the pressure sensor 19 regardless of the collision position of the bumper 5. In addition, there is no time lag that takes a long time to detect the pressure sensor 19, and good pedestrian collision detection performance can be obtained.
In addition, the amount of deformation of the silicon tube 17 can be suppressed by the groove 27 whose depth is set to the depth dimension d2, and a simple structure is sufficient.

In particular, the groove 27 has a depth dimension at which the output value of the pressure sensor 19 is uniform when the same colliding body collides with the center side and the end side (both in the vehicle width direction) of the bumper 5 under the same conditions. By setting to d2, the pressure sensor 19 can maintain a constant detection performance.
Note that the present invention is not limited to the above-described embodiment, and various modifications may be made without departing from the spirit of the present invention. For example, in one embodiment, the example in which the groove portion is also provided on the center side of the bumper has been described. You may make it suppress the deformation amount of a tube member. Of course, the present invention is not limited to the pedestrian detection device assembled to the front bumper of the vehicle, and may be applied to a pedestrian detection device assembled to the rear bumper of the vehicle.

1 Pedestrian collision detection device 3 Body (vehicle)
5 Bumper 7 Bumper Reinforce Member 9 Bumper Face Member 11 Shock Absorbing Member 13 Leg of Bumper Reinforce Member 17 Silicon Tube (Tube Member)
19 Pressure sensor 21 Control part 25 Tube deformation suppression part 27 Groove part 29 Support member

Claims (3)

A bumper reinforcement member configured to extend along the vehicle width direction, and a bumper face member disposed on the front side of the bumper reinforcement member;
A flexible tube member provided to extend in the vehicle width direction between the bumper reinforcement member and the bumper face member;
In a pedestrian collision detection device configured to include a pressure sensor provided at each end of the tube member and detecting a pressure change in the tube member due to a collision with the bumper,
A pedestrian having a tube deformation suppressing portion that suppresses a deformation amount of the tube portion when the bumper collides with the vehicle width direction end side of the bumper around the tube portion at the vehicle width direction end portion of the tube member. Collision detection device.   The tube deformation suppressing portion is formed on a front surface of the bumper reinforcement member, and is configured by a groove portion that fits the tube portion and has a depth that restricts a deformation amount of the tube portion to a predetermined value. The pedestrian collision detection device according to 1.   The depth of the groove is a depth at which the output value of the pressure sensor is uniform when the same colliding body collides with the vehicle width direction center side and the vehicle width direction end side of the bumper under the same conditions. The pedestrian collision detection device according to claim 2, having dimensions.

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