JP2011255793A - Collision detection device for vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a collision detection device for a vehicle, allowing a chamber to be reliably fixed even with a small number of attaching parts and to be easily attached to the vehicle.SOLUTION: The collision detection device includes: the chamber 3 made of an elastic member having a hollow portion therein; and a pressure sensor 4 for detecting a pressure change in the hollow portion. The collision detection device can detect collision of an object to the vehicle based on the output of the pressure sensor 4. The chamber 3 is biased toward a bumper reinforcement 1 of the vehicle by stress SB by action of springback accompanying elastic deformation of the chamber itself. The chamber includes a side end part W2 which bends at a predetermined angle (α°) with regard to the vehicle width direction at both ends in the vehicle width direction before installation to the vehicle, and the bumper reinforcement 1 on which the chamber 3 is fixed has its ends in the vehicle width direction bent at β° with regard to the vehicle width direction, where α is set to be larger than β.

Description

  The present invention relates to a vehicle collision detection device that detects a collision of an object with a vehicle.

  In recent years, for the purpose of protecting pedestrians, it is determined whether or not the colliding object is a pedestrian when an object collides with a vehicle. The practical application of a technology for operating an air bag is underway.

  As a means for detecting the collision of an object with a vehicle, for example, Patent Document 1 discloses an impact force at the time of an object collision as well as being arranged on the vehicle front side of a bumper reinforcement extending in the vehicle width direction of the vehicle. Absorber that absorbs by compressive deformation, a chamber that is disposed in front of the bumper reinforcement on the vehicle and has a hollow part that can be deformed inside, and a pressure sensor that can detect a pressure change in the hollow part , A vehicle collision detection device is disclosed. This vehicle collision detection device can detect a collision by utilizing the fact that when an object collides with the vehicle, the chamber is deformed along with the compression deformation of the absorber, and the atmospheric pressure in the hollow portion is changed. A mounting portion protruding in a tongue shape is formed integrally with the main body portion at two locations in the vehicle width direction in the chamber, and the chamber is fixed to a bumper reinforcement upper surface of the bumper reinforcement via the mounting portion. Fixed by.

  Further, Patent Document 2 discloses a vehicle collision detection device in which tongue-shaped attachment portions protruding from the chamber are arranged at approximately equal intervals in the vehicle width direction in order to fix the chamber to the bumper reinforcement. Is disclosed. The attachment portions are each bolted to the upper surface of the bumper reinforcement.

JP 2009-220785 A JP 2010-47113 A

  Here, since the chamber is a long member extending in the vehicle width direction, the fixing strength of the entire chamber with respect to the bumper reinforcement is insufficient when fixing only two places in the vehicle width direction as in Patent Document 1. Therefore, the position of the chamber with respect to the bumper reinforcement is greatly displaced due to the vibration generated by the traveling of the vehicle, and there is a concern that a pressure change occurs in the hollow portion and erroneously detects a collision.

  Therefore, as in Patent Document 2, if a large number of mounting portions are provided in the vehicle width direction of the chamber, the processing cost of the chamber increases, and the number of work steps for mounting on the vehicle increases.

  The present invention has been made in view of such circumstances, and provides a collision detection device for a vehicle in which the chamber can be reliably fixed even with a small number of mounting portions and the chamber can be easily mounted on the vehicle. With the goal.

(Invention of Claim 1)
A vehicle collision detection apparatus according to the present invention includes a chamber made of an elastic member having a hollow portion therein, and a pressure sensor that detects a change in atmospheric pressure in the hollow portion, and the collision of an object with the vehicle based on the output of the pressure sensor. In the vehicular collision detection device, the chamber is urged toward the bumper reinforcement of the vehicle by the action of a springback accompanying its own elastic deformation.

A chamber made of an elastic member acts as a springback that returns to its original state when it is elastically deformed by an external force, so that a stress in that direction is generated in the chamber. This stress biases the chamber toward the bumper reinforcement so that the chamber is securely fixed and positioned relative to the bumper reinforcement.
(Invention of Claim 2)
2. The collision detection device for a vehicle according to claim 1, wherein the chamber is refracted at a predetermined angle with respect to the vehicle width direction at a center portion substantially parallel to the vehicle width direction at a vehicle width direction center and at both ends in the vehicle width direction. An end portion, and the side end portion is biased toward the bumper reinforcement.

Since the side edge of the chamber is refracted at a predetermined angle with respect to the vehicle width direction, when the chamber is assembled to the bumper reinforcement, the chamber is elastically deformed to conform to the shape of the bumper reinforcement. . Due to the action of the springback accompanying this elastic deformation, stress in the bumper reinforcement direction is generated at the side end. This stress urges the chamber toward the bumper reinforcement.
(Invention of Claim 3)
The collision detection device for a vehicle according to claim 2, wherein when the predetermined angle in the state before the chamber is assembled to the vehicle is α °, the bumper reinforcement has both ends in the vehicle width direction with respect to the vehicle width direction. It is refracted at an angle β °, and α is an angle larger than β.

The refraction angle α of the side end portion before the chamber is assembled to the vehicle is set to be larger than the refraction angle β of the bumper reinforcement. For this reason, when the chamber is assembled to the bumper reinforcement, the side end of the chamber is elastically deformed into a shape that conforms to the shape of the bumper reinforcement, and the refraction angle α becomes substantially equal to β. Due to the action of the springback accompanying this elastic deformation, stress in the bumper reinforcement direction is generated at the side end.
(Invention of Claim 4)
The vehicle collision detection device according to any one of claims 1 to 3, wherein a tongue-shaped mounting portion protrudes from a central portion of the chamber, and the chamber is fixed to the bumper reinforcement via the mounting portion. It is characterized by.

At the same time that the central portion of the chamber is fixed to the bumper reinforcement by the tongue-shaped attachment portion, the side end portion of the chamber is biased toward the bumper reinforcement by the action of the spring back. As a result, even if only the central portion of the chamber is fixed, as a result, the entire chamber is securely fixed and positioned with respect to the bumper reinforcement.
(Invention of Claim 5)
5. The vehicle collision detection device according to claim 4, wherein the bumper reinforcement is formed with a first mounting hole, and the mounting portion is formed by inserting the first fixing member into the first mounting hole. It is fixed to the reinforcement.

By inserting the first fixing member into the first mounting hole formed in advance in the bumper reinforcement, the mounting portion of the chamber can be securely fixed to the bumper reinforcement.
(Invention of Claim 6)
The collision detection device for a vehicle according to claim 4 or 5, wherein the attachment portion is formed integrally with the chamber.

Accordingly, the mounting portion can be provided in the chamber without adding the number of parts.
(Invention of Claim 7)
7. The vehicle collision detection device according to claim 5, wherein the first fixing member is a pin-shaped clip having a wedge portion at a tip, and the wedge portion is engaged with the first attachment hole. It is characterized by that.

As a result, the mounting portion can be easily fixed to the bumper reinforcement, and the fixing member can be reliably prevented from coming off.
(Invention of Claim 8)
The vehicle collision detection device according to any one of claims 1 to 7, wherein the pressure sensor is attached to the chamber via a bracket, and the bracket is fixed to a bumper reinforcement.

By fixing the bracket for attaching the pressure sensor to the chamber to the bumper reinforcement, the chamber can be fixed to the bumper reinforcement via the bracket. As a result, the fixing by the mounting portion of the chamber can be reinforced, and even a chamber having no mounting portion can be easily fixed to the bumper reinforcement.
(Invention of Claim 9)
9. The collision detection device for a vehicle according to claim 8, wherein the bumper reinforcement is formed with a second mounting hole, and the bracket is inserted into the second mounting hole by inserting the second fixing member into the bumper rain. It is fixed to the force.

By inserting the second fixing member into the second mounting hole formed in advance in the bumper reinforcement, the bracket can be reliably fixed to the bumper reinforcement.
(Invention of Claim 10)
10. The vehicle collision detection device according to claim 9, wherein the second fixing member is a pin-shaped clip that protrudes from the lower surface of the bracket and has a wedge portion at the tip, and the wedge portion is formed in the second mounting hole. It is characterized by being engaged.

As a result, the mounting portion can be easily fixed to the bumper reinforcement, and the fixing member can be reliably prevented from coming off.
(Invention of Claim 11)
10. The vehicle collision detection device according to claim 9, wherein the second fixing member is a bolt having a male screw portion, and a female screw portion communicating with the second mounting hole is formed on the lower surface of the bracket. Is screwed into the female thread portion through the second mounting hole.

Thereby, the bracket can be firmly fixed to the bumper reinforcement by an easy means of screwing with a bolt.
(Invention of Claim 12)
12. The vehicle collision detection device according to claim 2, wherein an absorber that absorbs an impact force of the collision with the vehicle is arranged in parallel with the chamber, and the absorber stands in front of the central portion of the chamber. It has a wall part, The front-end surface of a center part is contact | abutting to the rear-end part of a wall part, It is characterized by the above-mentioned.

  As a result, the central part of the chamber is sandwiched between the wall of the absorber and the bumper reinforcement, so that it is possible to reinforce the fixing with the mounting part of the chamber and the bracket of the pressure sensor, and there is no structure with no mounting part or bracket Even these chambers can be easily fixed to the bumper reinforcement.

It is a top view which shows the structure of the collision detection apparatus for vehicles which concerns on this invention. It is AA sectional drawing of FIG. 1 at the time of (a) normal time and (b) collision. It is explanatory drawing of the chamber which concerns on Example 1 before the assembly | attachment to the vehicle (a) after the assembly | attachment to the vehicle. It is explanatory drawing of the chamber which concerns on Example 2 before the assembly | attachment to the vehicle (a) after the assembly | attachment to the vehicle. FIG. 6 is a cross-sectional view taken along the line BB in FIG. FIG. 6 is a cross-sectional view taken along line B-B of FIG. FIG. 6 is a cross-sectional view taken along the line B-B of FIG.

Embodiments of the present invention will be described below with reference to the drawings. However, parts corresponding to each other in all the drawings in this specification are denoted by the same reference numerals, and description of the overlapping parts will be omitted as appropriate.
Example 1
1 is a plan view showing a configuration of a vehicle collision detection apparatus according to Embodiment 1 of the present invention. In FIG. 1, the front half of the vehicle is shown in a simplified manner, and the engine room is further seen through.

  2 is a cross-sectional view taken along line AA of FIG. 1 at (a) normal time and (b) at the time of collision.

  The vehicle collision detection device shown in FIGS. 1 and 2 is disposed on the vehicle front side of a bumper reinforcement 1 extending in the vehicle width direction of the vehicle and absorbs an impact force caused by an object collision by compressive deformation. Detecting the pressure change in the hollow portion 3a, the chamber 3 having the hollow portion 3a that is parallel to the front side of the bumper reinforcement 1 and above the absorber 2 and that can be deformed inside the absorber 2. Possible pressure sensor 4.

  As shown in FIG. 1, the absorber 2 extends in the vehicle width direction as shown in FIG. 2A at the front end portions of the two side members 5 that are installed in the vehicle longitudinal direction and constitute the vehicle skeleton. The bumper reinforcement 1 is arranged such that one end surface abuts against the lower half of the vehicle front side. Here, the bumper reinforcement 1 is provided in order to ensure the strength of the front portion of the vehicle against the collision of an object, and is generally made of a highly rigid metal material. The material constituting the absorber 2 is a foamed resin having excellent elasticity such as foamed polypropylene (PP), for example, and at the time of a vehicle collision, as shown in FIG. It has a function to absorb by compressive deformation.

  As shown in FIG. 1, the chamber 3 is a long box-shaped synthetic resin member having a substantially arcuate shape in the vehicle width direction. As shown in FIG. 2A, the vehicle of the bumper reinforcement 1 is used. It is arranged in parallel with the absorber 2 so that one end surface side contacts the upper half of the front side. At the time of a vehicle collision, as shown in FIG. 2B, the capacity of the hollow portion 3a is reduced by the deformation of the hollow portion accompanying the compression deformation of the absorber 2. Further, the chamber 3 is disposed away from the absorber 2 in order to allow the bulge in the vertical direction accompanying the deformation of the hollow portion 3a.

  As shown in FIG. 2A, the pressure sensor 4 is attached via a bracket 4 b so that the sensitive part 4 a is inserted into the hollow part 3 a with respect to the hole formed in the chamber 3. The sensing unit 4a detects a change in atmospheric pressure in the hollow portion of the chamber 3 due to a vehicle collision, and outputs the change in atmospheric pressure as an electrical signal. The output signal is transmitted to an ECU (electronic control unit) (not shown) or the like via an output line 4c, and is used as information for controlling the operation of an active hood or a pedestrian protection airbag (not shown). Since the control method here is a well-known technique, a detailed description is omitted.

  As shown in FIG. 2A, the absorber 2 and the chamber 3 are covered at the front part by a bumper cover 6 that is arranged with a predetermined space from each front end part. Since the bumper cover 6 constitutes a design in front of the vehicle, the bumper cover 6 may be a member having relatively low strength. When an object collides with the vehicle, the bumper cover 6 comes into contact with the front end of the absorber 2 and the chamber 3 with deformation as shown in FIG.

  Next, the chamber 3 according to the characterizing portion of the present invention will be described in detail with reference to FIG.

  As shown in FIG. 3A, the chamber 3 has a central portion W1 that is substantially parallel to the vehicle width direction at the center in the vehicle width direction and a vehicle width direction at both ends in the vehicle width direction before being assembled to the vehicle. And a side end W2 that is refracted at a predetermined angle (α °). The bumper reinforcement 1 to which the chamber 3 is fixed is also refracted at β ° with respect to the vehicle width direction at the end in the vehicle width direction. The refraction angle α ° of the chamber is the refraction angle β of the bumper reinforcement 1. It is set larger than °. Here, the vehicle width direction means a direction perpendicular to the center line in the front-rear direction of the vehicle.

  In the assembly process of the chamber 3 to the vehicle, the side end W2 of the chamber 3 has a refraction angle α ° larger than the refraction angle β ° of the bumper reinforcement. Abuts against reinforcement 1. At this time, a space is generated between the central portion W1 and the bumper reinforcement 1. Thereafter, the chamber 3 is elastically deformed along the shape of the bumper reinforcement 1 while being elastically deformed, and the space with the bumper reinforcement 1 is gradually reduced. As shown in FIG. 3B, when the central portion W1 of the chamber 3 is completely in contact with the bumper reinforcement 1, the refraction angle α ° of the chamber 3 is the refraction angle of the bumper reinforcement 1. It becomes approximately equal to β °. At this time, due to the action of the spring back accompanying the elastic deformation of the chamber 3, a stress SB in the direction of the arrow shown in FIG. That is, the side end portion W <b> 2 of the chamber 3 is urged toward the bumper reinforcement 1.

From the central portion W1 of the chamber 3, two tongue-shaped attachment portions 3b are integrally projected by a synthetic resin member that constitutes the chamber 3. Further, the bumper reinforcement 1 is previously formed with a mounting hole 1a (first mounting hole of the present invention) at a position corresponding to the mounting portion 3b when the chamber 3 is assembled. Then, the chamber 3 is fixed to the mounting hole 1a of the bumper reinforcement 1 by fixing the mounting portion 3b of the chamber 3 with, for example, a pin-shaped clip 7 (first fixing member of the present invention) having a wedge portion at the tip. Is assembled to the bumper reinforcement 1 and kept in an elastically deformed state. Here, since the clip 7 is a known general-purpose product, a detailed description thereof is omitted.
(Effect of Example 1)
According to the configuration of the first embodiment, the chamber 3 generates a stress SB at the side end portion W2 due to the action of the spring back accompanying the elastic deformation of the chamber 3 when it is assembled to the bumper reinforcement 1. Since the chamber 3 is fixed to the bumper reinforcement 1 by the mounting portion 3b protruding from the central portion W1 while maintaining the elastic deformation state, the stress SB is always on the side after the assembly to the bumper reinforcement 1 of the chamber 3. Working at end W2. The stress SB is directed toward the bumper reinforcement 1 as shown in FIG. 3B, so that the chamber 3 is urged toward the bumper reinforcement 1. As described above, by effectively utilizing the action of the spring back associated with the elastic deformation of the chamber 3 and assembling the bumper reinforcement 1, the number of mounting portions 3b is small (in this embodiment, two in the central portion W1). Even so, the chamber 3 is securely fixed and positioned. This eliminates the need for a large number of mounting portions 3b, thereby reducing the processing cost of the chamber 3 and reducing the number of assembling operations. In addition, a pressure change occurs in the hollow portion 3a due to vibration generated by running of the vehicle. The possibility of erroneously detecting a collision is suppressed.

  In addition, the mounting hole 1a is formed in advance in the bumper reinforcement 1 at a position corresponding to the mounting portion 3b when the chamber 3 is assembled, so that the chamber 3 can be made bumper reinforcement by an easy means such as the clip 7. 1 can be fixed.

  And the attachment part 3b can be provided in the chamber 3 without adding a number of parts by forming the attachment part 3b in the chamber 3 which is a synthetic resin member by integral molding. Further, since the mounting portion 3b is integrally molded, the rigidity is high, the reaction force of the stress SB due to the action of the spring back of the chamber 3 can be sufficiently received, and the reliability of the strength of the apparatus is high.

In the present embodiment, the end portions in the vehicle width direction of the chamber 3 and the bumper reinforcement 1 are refracted, but one or both of them may be curved. For example, by making the radius of curvature of the chamber 3 smaller than the radius of curvature of the bumper reinforcement 1, the same springback action as in the present embodiment occurs, and the same effect can be obtained.
(Example 2)
In the second embodiment, instead of fixing the chamber 3 to the bumper reinforcement 1 by the mounting portion 3b in the first embodiment, as shown in FIG. 4, the bracket 4b of the pressure sensor 4 is effectively used and fixed. Is. Hereinafter, a specific configuration of fixing by the bracket 4b will be described.

  As shown in FIG. 4, a pressure sensor 4 is disposed at the approximate center of the chamber 3 in the vehicle width direction. As shown in FIG. 5, the pressure sensor 4 is fixed to the chamber 3 via a bracket 4b. On the bracket 4b, a clip portion 8 (second fixing member of the present invention) is formed so as to protrude from the bottom portion. An attachment hole 1b (second attachment hole of the present invention) is formed in advance at a position corresponding to the pressure sensor 4 when the chamber 3 is assembled. Then, the bracket 4b is fixed to the bumper reinforcement 1 by inserting the clip portion 8 of the bracket 4b into the mounting hole 1b. As a result, the chamber 3 is fixed to the bumper reinforcement 1 via the bracket 4b.

  As already described in the first embodiment, as shown in FIG. 4, the chamber 3 is urged toward the bumper reinforcement 1 by the stress SB due to the action of the springback accompanying its own elastic deformation. For this reason, the chamber 3 can be fixed to the bumper reinforcement 1 as a whole even if the bracket 4b of the pressure sensor 4 located substantially in the center in the vehicle width direction is used.

  Of course, it is good also as a structure which has the attaching part 3b of Example 1 in addition to the said structure. In this case, the fixing by the bracket 4b can reinforce the attachment portion 3b, and the reliability in terms of the strength of the apparatus can be further improved.

Other configurations and effects are the same as those of the first embodiment.
(Modification 1)
In Example 2, instead of fixing the bracket 4b to the bumper reinforcement 1 with the clip portion 8 protruding from the bottom, a bolt 9 may be used as shown in FIG. In this case, an internal thread portion is formed on the inner periphery of the mounting hole 1b formed in the bumper reinforcement 1, and the bolt 9 passes from the upper surface of the pressure sensor 4 to the lower surface of the bracket 4b and is screwed into the mounting hole 1b. Match. Accordingly, the bracket 4b can be firmly fixed to the bumper reinforcement 1 by an easy means of screwing with the bolt 9.

Of course, instead of forming the female screw portion in the mounting hole 1b of the bumper reinforcement 1, the bolt 9 may be fastened by a known means such as a nut.
(Modification 2)
As shown in FIG. 7, when the absorber 2 arranged in parallel with the chamber 3 is disposed in front of the bumper reinforcement 1 and has a wall portion 2 a that stands in front of the central portion W <b> 1 of the chamber 3, It is good also as a structure which the front-end surface of center part W1 contact | abuts the rear-end part of the wall part 2a. As a result, the central portion W1 of the chamber 3 is sandwiched between the wall portion 2a of the absorber 2 and the bumper reinforcement 1, so that the mounting portion 3b of the chamber 3 of the first embodiment and the pressure sensor 4 of the second embodiment are arranged. In addition to reinforcing the fixing by the bracket 4b, the chamber 3 having no mounting portion 3b or the bracket 4b can be easily fixed to the bumper reinforcement 1.

1 Bumper reinforcement 1a Mounting hole (first mounting hole)
1b Mounting hole (second mounting hole)
2 Absorber 2a Wall 3 Chamber 3a Hollow 3b Mounting 4 Pressure sensor 4b Bracket 7 Clip (first fixing member)
8 Clip part (second fixing member)
9 Bolt (second fixing member)

Claims (12)

A chamber made of an elastic member having a hollow portion inside,
A pressure sensor for detecting a change in atmospheric pressure in the hollow portion,
In a vehicle collision detection device that enables detection of a collision of an object with a vehicle based on an output of the pressure sensor,
The vehicle collision detection device according to claim 1, wherein the chamber is biased toward a bumper reinforcement of the vehicle by an action of a springback accompanying its own elastic deformation. The vehicle collision detection device according to claim 1,
The chamber has a central portion that is substantially parallel to the vehicle width direction at the center in the vehicle width direction and side end portions that are refracted at a predetermined angle with respect to the vehicle width direction at both ends in the vehicle width direction.
The vehicle collision detection device, wherein the side end portion is biased toward the bumper reinforcement. The vehicle collision detection device according to claim 2,
When the predetermined angle in the state before the assembly of the chamber to the vehicle is α °,
The bumper reinforcement is refracted at an angle β ° with respect to the vehicle width direction at both ends in the vehicle width direction, and α is an angle larger than β. In the vehicle collision detection device according to any one of claims 1 to 3,
A vehicular collision detection device, wherein a tongue-shaped attachment portion projects from the central portion of the chamber, and the chamber is fixed to the bumper reinforcement through the attachment portion. The vehicle collision detection device according to claim 4,
A first mounting hole is formed in the bumper reinforcement, and the mounting portion is fixed to the bumper reinforcement by inserting a first fixing member into the first mounting hole. A vehicle collision detection device. In the vehicle collision detection device according to claim 4 or 5,
The vehicle collision detection device, wherein the attachment portion is formed integrally with the chamber. In the vehicle collision detection device according to claim 5 or 6,
The vehicular collision detection device, wherein the first fixing member is a pin-shaped clip having a wedge portion at a tip, and the wedge portion is engaged with the first mounting hole. In the vehicle collision detection device according to any one of claims 1 to 7,
The pressure sensor is attached to the chamber via a bracket;
The vehicle collision detection device, wherein the bracket is fixed to the bumper reinforcement. The vehicle collision detection device according to claim 8,
A second mounting hole is formed in the bumper reinforcement, and the bracket is fixed to the bumper reinforcement by inserting a second fixing member into the second mounting hole. A vehicle collision detection device. The vehicle collision detection device according to claim 9,
The second fixing member is a pin-like clip that protrudes from the lower surface of the bracket and has a wedge portion at the tip, and the wedge portion is engaged with the second mounting hole. A vehicle collision detection device. The vehicle collision detection device according to claim 9,
The second fixing member is a bolt having a male screw portion,
A female thread portion communicating with the second mounting hole is formed on the lower surface of the bracket,
The vehicle collision detection device according to claim 1, wherein the bolt is screwed into the female screw portion through the second mounting hole. In the vehicle collision detection device according to any one of claims 2 to 11,
An absorber that absorbs the impact force of the collision with the vehicle is juxtaposed in the chamber,
The absorber has a wall portion that stands in front of the central portion of the chamber,
A collision detection apparatus for a vehicle, wherein a front end surface of the central portion is in contact with a rear end portion of the wall portion.

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