JP5354301B2 - Vehicle collision detection device - Google Patents

Description

  The present invention relates to a collision detection device that detects a collision of a pedestrian or the like with a vehicle.

  In recent years, regarding vehicle safety, not only ensuring the safety of a vehicle occupant during an accident, but also reducing the damage to the pedestrian when the pedestrian collides with the vehicle is required. Therefore, by detecting a collision of a pedestrian with a vehicle and operating a pedestrian protection device such as an active hood or a cowl airbag, the injury value (walking) that a pedestrian who collides with the vehicle and falls into the hood Have been proposed to reduce the impact received by a person.

  For example, as described in Japanese Patent Application Laid-Open No. 2006-117157 (Patent Document 1), a chamber member is disposed in front of a bumper reinforcement in a vehicle bumper, and a pressure change in a chamber space is detected by a pressure sensor. There has been proposed a vehicle collision detection device configured to detect a collision of a pedestrian or the like with a vehicle bumper by detection. That is, the chamber member is deformed by the collision, and the collision of a pedestrian or the like is detected based on the pressure change in the chamber space.

JP 2006-117157 A

  In such a chamber type collision detection device, it is required to increase the sensor output and improve the S / N ratio.

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide a vehicle collision detection device capable of increasing the output of a pressure sensor and improving the S / N ratio.

  The invention according to claim 1, which has been made to achieve the above object, includes a chamber member disposed on a front surface of a bumper reinforcement within a bumper cover of a vehicle bumper and having a chamber space formed therein. A vehicle comprising: an absorber disposed on a front surface of a reinforcement; and a pressure sensor that detects a pressure in a chamber space, and configured to detect a collision with a bumper cover based on a detection result of the pressure sensor. In the collision detection apparatus, the chamber member includes a chamber main body portion in which the chamber space is formed, and an insertion member disposed between the rear wall of the chamber main body portion and the front surface of the bumper reinforcement, In the cross-section perpendicular to the extending direction of the chamber member, the width of the insertion member in the vehicle longitudinal direction is the width in the vehicle longitudinal direction where the absorber remains crushed in the event of a collision. And said that it is the lower.

  According to this configuration, the presence of the insertion member reduces the initial volume of the chamber space. Thereby, the degree of the pressure increase at the time of a collision becomes large, and the output of a pressure sensor can be enlarged. An insertion member having a predetermined width in the front-rear direction is disposed behind the chamber body. The occupied portion of the insertion member is originally a portion where the chamber member (chamber space) is not deformed by the collision, and therefore there is no influence on the pressure change due to the collision. Therefore, it is possible to detect a collision without deteriorating accuracy. In the present invention, “at the time of collision” means when an adult (male) collides with a vehicle bumper at the upper limit speed of operation of the pedestrian protection device. The general operation upper limit condition is about 50 to 60 km / h.

  The invention according to claim 2 is characterized in that the chamber member includes a chamber main body portion in which the chamber space is formed, and an insertion member installed in the chamber main body and on the rear wall.

  According to this configuration, as in the first aspect of the invention, the initial volume of the chamber space can be reduced and the output of the pressure sensor can be increased.

  The invention according to claim 3 is characterized in that the insertion member is made of foamed resin, polypropylene, or polyethylene. According to this configuration, even if the pedestrian's leg reaches the insertion member at the time of the collision, the insertion member itself is soft, so that the leg can be sufficiently protected.

  The invention according to claim 4 is characterized in that the insertion member is a hollow member made of polyethylene or polypropylene. According to this configuration, as described above, since the insertion member itself is soft, the leg portion can be sufficiently protected.

  The invention according to claim 5 is characterized in that, in the cross-section orthogonal to the extending direction of the chamber member, the width of the insertion member in the vehicle front-rear direction is 20% or less of the width of the chamber member in the vehicle front-rear direction. According to this configuration, it is possible to reliably increase the output of the pressure sensor and improve the S / N ratio.

  The invention according to claim 6 is characterized in that the chamber body and the insertion member are integrally formed. According to this structure, the attachment to a vehicle becomes easy.

  The invention according to claim 7 is characterized in that the insertion member is installed in the entire vehicle width direction of the chamber body. According to this configuration, the sensor output can be increased more effectively.

BRIEF DESCRIPTION OF THE DRAWINGS It is a whole block diagram which shows the collision detection apparatus 1 for vehicles of 1st embodiment by planar view. It is principal part sectional drawing which looked at the collision detection apparatus 1 for vehicles of 1st embodiment from the side. It is a figure which shows the output signal of a pressure sensor. It is principal part sectional drawing which shows the deformation | transformation aspect of 1st embodiment. It is a schematic cross section showing chamber member 7A of a second embodiment. It is a schematic cross section which shows the chamber member 7B of 3rd embodiment.

  Next, the present invention will be described in more detail with reference to embodiments.

<First embodiment>
A first embodiment will be described with reference to FIGS. As shown in FIG. 1, the vehicle collision detection device 1 includes a chamber member 7 disposed in a vehicle bumper 2, a pressure sensor 8, a pedestrian protection device electronic control unit (hereinafter referred to as an electronic control unit as an ECU). (Abbreviated) 10.

  As shown in FIGS. 1 and 2, the vehicle bumper 2 is mainly composed of a bumper cover 3, a bumper reinforcement 4, a side member 5, an absorber 6, and a chamber member 7.

  The bumper cover 3 is a resin (for example, polypropylene) cover member that extends in the vehicle width direction (left-right direction) at the front end of the vehicle and is attached to the vehicle body so as to cover the bumper reinforcement 4, the absorber 6, and the chamber member 7. is there.

  The bumper reinforcement 4 is a metal structural member that is disposed in the bumper cover 3 and extends in the vehicle width direction, and as shown in FIG. It is a hollow member which has.

  The side members 5 are a pair of metal members that are located on both the left and right sides of the vehicle and extend in the vehicle front-rear direction, and the bumper reinforcement 4 described above is attached to the front ends thereof.

  The absorber 6 is a foamed resin member that extends in the vehicle width direction and is attached to the lower side of the front surface 4 a of the bumper reinforcement 4 within the bumper cover 3, and exhibits an impact absorbing action in the vehicle bumper 2.

  The chamber member 7 is disposed in the bumper cover 3 above the bumper reinforcement front surface 4a. The chamber member 7 includes a chamber main body 71 and an insertion member 72. The chamber body 71 has a body 711 and an extending part 712, and forms a chamber space 71a therein.

  Specifically, the main body 711 is a substantially box-shaped hollow member made of a soft resin such as polyethylene and extending in the vehicle width direction. The main body 711 forms a substantially sealed chamber space 71a extending in the vehicle width direction and surrounded by a soft resin wall surface having a thickness of several millimeters. The main body 711 is disposed on the front surface of an insertion member 72 described later. The main body 711 is a part that is deformed by a collision, and a pressure change in the main body 711 is detected as a pressure change in the chamber space 71a.

  The extending portion 712 is integrally formed with the main body portion 711 by a soft resin, extends from a substantially central portion in the vehicle width direction of the main body portion 711 to above the bumper reinforcement upper surface 4b, and from the front side of the vehicle body to the rear side of the vehicle body It is an extended part. The internal space of the extending portion 712 communicates with the internal space of the main body portion 711, and forms a part of the chamber space 71a. In addition, an insertion port 712 a that allows the internal space (that is, the chamber space 71 a) to communicate with the outside is provided in the upper portion of the extending portion 712.

  An insert member 712b is insert-molded in the vicinity of the insertion port 712a in the upper portion of the extended portion 712. Insert molding is one of blow molding methods, and is integrated with the main body 711 by installing the insert member 712b in a mold and inflating a soft resin. The insert member 712b is made of a material harder than the soft resin that is the material of the chamber body 71, for example, a metal such as iron, or a hard resin such as nylon or PBT (polybutylene terephthalate). The insert member 712b is a member for attaching the pressure sensor 8 described later to the chamber body 71. That is, the pressure sensor 8 is screwed to the insert member 712b. The insert member 712b is provided with a through hole corresponding to the insertion port 712a.

  The insertion member 72 is a plate-shaped foamed resin member that extends in the vehicle width direction and is disposed above the front surface 4 a of the bumper reinforcement 4 in the bumper cover 3. The insertion member 72 is disposed between the rear wall 71 b of the chamber body 71 and the front surface 4 a of the bumper reinforcement 4. The insertion member 72 is a substantially rectangular parallelepiped plate-like body, and extends in the entire vehicle width direction in which the chamber body 71 extends in accordance with the chamber body 71. The insertion member 72 is formed integrally with the chamber body 71 by welding (or adhesion) during molding or the like.

  In the cross-section orthogonal to the extending direction of the chamber member 7 (see FIG. 2), the width A in the vehicle front-rear direction of the insertion member 72 is equal to or smaller than the width in the vehicle front-rear direction in which the absorber 6 remains crushed during a collision. In other words, the cross section perpendicular to the extending direction of the chamber member 7 is a cross section when the chamber member 7 is cut in a direction (substantially front-rear direction) orthogonal to the extending direction (substantially left-right direction) of the chamber member 7. The width A in the vehicle front-rear direction means the maximum lateral width in the cross section. Hereinafter, the width in the vehicle front-rear direction in the cross section is abbreviated as a lateral width.

  Specifically, the lateral width A of the insertion member 72 is approximately 10 mm. This is based on the lateral width in which the absorber 6 remains crushed during a collision. The height (vertical width) of the insertion member 72 is approximately the same as that of the main body 711.

  In this embodiment, the lateral width in which the absorber 6 remains crushed is calculated assuming that the lateral width of the initial absorber 6 is approximately 50 mm and an adult (male) collides with the vehicle bumper 2 at a speed of approximately 55 km / h. . That is, the result was that the absorber 6 having a width of 50 mm remained crushed by about 10 mm in width (about 20% of the cross-sectional area) due to the collision under the operating conditions.

  The lateral width of the chamber member 7 is approximately 50 mm. That is, the lateral width A of the insertion member 72 is set to approximately 20% of the lateral width of the chamber member 7. In the present embodiment, the lateral width A of the insertion member 72 is set to the maximum lateral width in which the absorber 6 remains crushed during a collision.

  The pressure sensor 8 is a sensor device capable of detecting a gas pressure, and is configured to be attached to the chamber main body 71 so as to detect a pressure change in the chamber space 71a. Specifically, the pressure sensor 8 includes a sensor main body 81 and a pressure introduction pipe 82. The sensor body 81 is a part that is outside the chamber body 71 and accommodates a substrate or the like on which a sensor element for pressure detection is provided. The sensor body 81 outputs a pressure signal and transmits a signal to the pedestrian protection apparatus ECU10 via the signal line 10a. The sensor main body 81 has a flange portion fixed to the insert member 712b of the extending portion 712 by screws.

  The pressure introduction pipe 82 is a substantially cylindrical pipe that introduces the pressure of the chamber space 71 a into the sensor body 81, and extends downward from the sensor body 81. The pressure introducing pipe 82 is inserted into an insertion port 712 a provided in the extending part 712 of the chamber body 71. The sensor main body 81 detects the pressure in the chamber space 71a via the pressure introduction pipe 82.

  The pedestrian protection device ECU 10 is an electronic control device for performing start-up control of a pedestrian protection device (not shown) (for example, a known pedestrian protection airbag or hood flip-up device), and is output from the pressure sensor 8. Signal is input via the transmission line 10a. The pedestrian protection device ECU 10 executes a process for determining whether or not a pedestrian (that is, a human body) has collided with the vehicle bumper 2 based on the pressure detection result of the pressure sensor 8.

  Here, the effect of this embodiment is demonstrated. In this embodiment, since the chamber member 7 has the insertion member 72, the initial volume of the chamber body 71 that forms the chamber space 71a is reduced accordingly. Thereby, the degree of the pressure rise with respect to a collision becomes large, and the output signal of the pressure sensor 8 also becomes large. As shown in FIG. 3, in this embodiment, the output increased by about 20% compared to the case where the insertion member 72 was not inserted (conventional). By increasing the output, the ratio (S / N ratio) between the sensor output signal due to the increase in air pressure in the chamber space 71a and the sensor output signal due to the noise component is improved.

  In addition, the fact that the absorber 6 remains crushed at the time of a collision means that it is not crushed any more at the time of the collision. Therefore, the rear part occupied by the insertion member 72 in the chamber member 7 is a part that does not deform at the time of collision even if the chamber main body 71 (chamber space 71a) extends to the rear part. This part is a part of the chamber member 7 that does not affect the pressure change at the time of collision. In the present embodiment, the insertion member 72 is disposed in the portion, and only the output can be increased without affecting the collision detection accuracy.

  In this embodiment, the initial volume of the chamber space 71a is minimized by setting the lateral width A of the insertion member 72 to the lateral width where the absorber 6 remains uncrushed. Therefore, the output of the pressure sensor 8 can be increased most effectively. However, the lateral width A of the insertion member 72 only needs to be equal to or less than the lateral width remaining to be crushed, and the occupied volume integral and output of the insertion member 72 can be increased.

  The lateral width of the absorber 6 that remains crushed may vary depending on the shape of the absorber 6 and the like, but the absorber 6 is mounted in the vehicle bumper 2 and a dummy assuming an adult (male) is set to a general operating upper limit condition (50 to 60 km / It can be easily identified by performing an experiment (or calculation) by colliding with h).

  The vehicle collision detection device 1 of the first embodiment is not limited to the above. For example, the chamber body 71 and the insertion member 72 may not be formed integrally. That is, the chamber body 71 and the insertion member 72 may be arranged without being welded (or bonded). The insertion member 72 may be formed by injection molding.

  Further, the insertion member 72 may not be made of foamed resin, but may be made of polypropylene (PP) or polyethylene (HDPE, LDPE, etc.). Moreover, the insertion member 72 may be a hollow member made of a soft resin (PE, PP, etc.) as shown in FIG. In this case, the insertion member 72 may be formed in the same manner as the chamber main body 71. This also makes it possible to sufficiently protect the legs.

  Further, the lateral width A of the insertion member 72 is preferably equal to or less than the lateral width that remains to be crushed and is approximately 20% or less of the lateral width of the chamber member 7. In addition, it is preferable that the lateral width A of the insertion member 72 is about 3 mm or more on a product design. Further, the lateral width A of the insertion member 72 may be equal to or less than the width that remains to be crushed, and may be equal to or greater than half the width that remains to be crushed. Thereby, a sensor output can be raised more effectively.

  A plurality of pressure sensors 8 may be installed. For example, two pressure sensors 8 may be installed at different locations of the chamber member 7, and one of them may be used as a safing sensor.

  Further, the insertion member 72 may be provided in a part of the chamber body 71 in the vehicle width direction. For example, the insertion member 72 may be installed on the central straight portion (the entire straight portion) of the chamber main body 71 excluding the end in the vehicle width direction of the chamber main body 71.

<Second embodiment>
The vehicle collision detection device of the second embodiment will be described with reference to FIG. In the second embodiment, unlike the first embodiment, the insertion member 72A is wound together at the time of blow molding and formed integrally with the chamber body 71A. The second embodiment has the same configuration as the first embodiment except for the shape of the main body and the insertion member. FIG. 5 shows only the configuration of the chamber member 7A in a simplified manner.

  The insertion member 72A is a soft resin member having a substantially rectangular parallelepiped shape, and the lateral width A is set to the maximum lateral width in which the absorber 6 remains crushed at the time of collision, as in the first embodiment. The height (vertical width) of the insertion member 72A is smaller than the chamber body 71A. The insertion member 72 </ b> A is located between the rear wall 71 </ b> Ab of the chamber body 71 </ b> A and the front surface 4 a of the bumper reinforcement 4. The effect similar to 1st embodiment is exhibited also by 2nd embodiment.

<Third embodiment>
A vehicle collision detection apparatus 1B according to a third embodiment will be described with reference to FIG. In the third embodiment, unlike the first embodiment, the insertion member 72B is arranged in the chamber main body 71B. FIG. 6 shows only the configuration of the chamber member 7B in a simplified manner.

  The insertion member 72B is a soft resin member having a substantially rectangular parallelepiped shape, the lateral width A is the same as that of the first embodiment, and the height is slightly smaller than the chamber body 71B. The insertion member 72B is disposed inside the chamber main body 71B and bonded to the rear wall 71Bb of the chamber member 71B (main body). The effect similar to 1st embodiment is exhibited also by 3rd embodiment.

1: vehicle collision detection device,
2: Vehicle bumper, 3: Bumper cover, 4: Bumper reinforcement,
5: Side member, 6: Absorber, 7, 7A, 7B: Chamber member,
71, 71A, 71B: chamber main body part, 711: main body part, 712: extension part,
72, 72A, 72B: insertion member,
8: Pressure sensor, 10: Pedestrian protection device ECU,

Claims (7)

A chamber member disposed in front of the bumper reinforcement within the bumper cover of the vehicle bumper and having a chamber space formed therein; an absorber disposed in front of the bumper reinforcement; and A vehicular collision detection device comprising: a pressure sensor that detects pressure; and configured to detect a collision with the bumper cover based on a detection result of the pressure sensor;
The chamber member includes a chamber body portion in which the chamber space is formed, and an insertion member disposed between a rear wall of the chamber body portion and a front surface of the bumper reinforcement,
The vehicle collision detection apparatus according to claim 1, wherein in the cross section orthogonal to the extending direction of the chamber member, a width in the vehicle front-rear direction of the insertion member is equal to or less than a width in the vehicle front-rear direction in which the absorber remains crushed in a collision. A chamber member disposed in front of the bumper reinforcement within the bumper cover of the vehicle bumper and having a chamber space formed therein; an absorber disposed in front of the bumper reinforcement; and A vehicular collision detection device comprising: a pressure sensor that detects pressure; and configured to detect a collision with the bumper cover based on a detection result of the pressure sensor;
The chamber member includes a chamber body part in which the chamber space is formed, and an insertion member installed in the chamber body part and on the rear wall,
The vehicle collision detection apparatus according to claim 1, wherein in the cross section orthogonal to the extending direction of the chamber member, a width in the vehicle front-rear direction of the insertion member is equal to or less than a width in the vehicle front-rear direction in which the absorber remains crushed in a collision.   The vehicle collision detection device according to claim 1, wherein the insertion member is made of foamed resin, polypropylene, or polyethylene.   The vehicle collision detection device according to claim 1, wherein the insertion member is a hollow member made of polyethylene or polypropylene.   The vehicle according to any one of claims 1 to 4, wherein a width of the insertion member in the vehicle front-rear direction is 20% or less of a width of the chamber member in the vehicle front-rear direction in a cross section orthogonal to the extending direction of the chamber member. Collision detection device.   The collision detection device for a vehicle according to any one of claims 1 to 5, wherein the chamber body and the insertion member are integrally formed.   The collision detection device for a vehicle according to any one of claims 1 to 6, wherein the insertion member is installed in the entire vehicle width direction of the chamber body.

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