JP5772780B2 - Vehicle collision detection device - Google Patents

Description

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

  Pedestrian protection devices that reduce damage to pedestrians when a vehicle collides with pedestrians have been put into practical use. This pedestrian protection device instantly raises the rear end of the engine hood after collision detection in order to reduce the impact of the pedestrian hitting the engine hood, and supports the increased stroke with a buffer mechanism. It is called by names such as pop-up hood, pop-up engine hood, active bonnet, and active hood. As another form, an airbag is deployed from the engine hood outside the vehicle body to the lower part of the front window to cushion the impact of pedestrians, and is called by the names of cowl airbags, hood airbags, etc. .

  In these devices, a bumper unit is provided with a collision detection device, which detects the contact of an object and operates the device. As such a collision detection device, a vehicle collision detection device is proposed in which a chamber member is disposed in a bumper and configured to detect a pressure change in the chamber when an object collides with the bumper ( For example, Patent Document 1).

  For example, in the vehicle collision detection device described in Patent Document 1, a breathing hole is provided on the lower surface side of the chamber member so that the inside of the chamber communicates with the outside so that the pressure in the chamber is always kept at atmospheric pressure. The pressure change in the chamber member due to the collision with the bumper can be accurately detected without being affected by the fluctuation. In addition, by providing a breathing hole on the lower surface side of the chamber member, it also functions as a drain hole for draining water accumulated inside the chamber member after running on a road flooded by the vehicle It is said.

JP 2012-96758 A

  However, when a breathing hole having a diameter of about 4 [mm] is provided on the lower surface side of the chamber member, when the vehicle travels on a rough road or a road flooded with muddy water, mud and sand are removed when muddy water is discharged. It turns out that there is a case to block. It was also found that insects and spiders may invade from the respiratory holes and form a nest in the respiratory hole. And when communication between the atmosphere in the chamber and the atmosphere is hindered due to these, the detection accuracy of the collision detection device decreases due to the influence of altitude difference and temperature, and the pedestrian protection device should be activated May malfunction, or may malfunction if it should not be activated.

  The present invention has been made in view of the above-described problems, and in a pressure detection chamber member, intrusion of muddy water and insects is prevented, the function of a breathing hole is secured, and a highly reliable vehicle collision is achieved. An object is to provide a detection device.

In order to achieve the above-mentioned object, the invention according to claim 1 comprises a chamber member having a chamber body disposed in front of a bumper force in a vehicle bumper and having a chamber space formed therein, and the chamber A collision sensor for a vehicle, comprising: a pressure sensor that is attached to a member and detects a pressure in the chamber space, and configured to detect a collision with the vehicle bumper based on a pressure detection result by the pressure sensor; The chamber member has a breathing hole that allows the chamber space to communicate with the outside at a position spaced in the vehicle width direction from a position where the pressure sensor is attached, and a filter member is attached to the breathing hole. The breathing hole is provided on a back surface of the chamber member, and the back surface of the chamber member provided with the breathing hole is formed on the bumper line. Contact with Osu, said filter member, said support together while ensuring ventilation and prevent venting membrane penetration of water (33), support for supporting the gas permeable membrane (32), covering the gas permeable membrane A cover member (34) for forming an opening between the body and the body, wherein the cover member and the support form a ventilation path of a labyrinth structure between the opening and the ventilation film, It is characterized in that it is provided behind the front surface of the bumper force through an opening hole formed at a position away from the left and right ends of the front surface of the bumper force.

  According to this configuration, since the filter member is attached to the breathing hole, it is possible to prevent foreign matter from entering the chamber member while ensuring air permeability. For example, since the intrusion of muddy water can be prevented even when the vehicle travels on a bad road or a road flooded with muddy water, the breathing hole is not blocked by sand or mud. Also, insects and spiders do not enter from the breathing holes, and the breathing holes are not blocked by the nesting. Therefore, the respiratory function of the breathing hole is ensured, and highly reliable collision detection can be performed.

It is a schematic diagram which shows the structure of the collision detection apparatus for vehicles in the 1st reference example of this invention by planar view. It is a schematic diagram which shows the structure in a vehicle bumper by a side view. It is III-III sectional drawing which shows the structure of the principal part of the collision detection apparatus for vehicles. It is IV-IV sectional drawing which shows the structure of the principal part of the collision detection apparatus for vehicles. It is an expanded sectional view which expands and shows the insert bracket and filter member in FIG. It is A view of the filter member in FIG. It is a disassembled perspective view which shows the structure of an insert bracket and a filter member. It is a schematic diagram which shows a mode that insert molding of an insert bracket is carried out with a metal mold | die in blow molding of a chamber member. It is IV-IV sectional drawing which shows the structure of the principal part of the collision detection apparatus for vehicles which concerns on embodiment of this invention . It is IV-IV sectional drawing which shows the structure of the principal part of the collision detection apparatus for vehicles which concerns on a 2nd reference example. It is a schematic diagram which shows the attachment state of the insert bracket and filter member in the chamber member which concerns on a 3rd reference example by planar view.

Hereinafter, reference examples and embodiments of a vehicle collision detection device of the present invention will be described with reference to the drawings. As shown in FIGS. 1 and 2, the vehicle collision detection device 1 according to the reference example of the present invention is configured to detect a collision of an object with a bumper 2 in front of the vehicle and activate the pedestrian protection device 3. Device.

  As shown in FIG. 1 and the like, the vehicle collision detection apparatus 1 includes a bumper 2, a chamber member 5 disposed in the bumper 2 and having a chamber space 4 formed therein, and a pressure change in the chamber space 4. A pressure sensor 6 to be detected and a pedestrian protection device electronic control unit (hereinafter, the electronic control unit is abbreviated as ECU) 7 are provided.

  As shown in FIGS. 3 and 4, which are enlarged sectional views of FIG. 2, the bumper 2 mainly includes a bumper cover 8, a chamber member 5, a bumper absorber 9, and a bumper force 10.

  The bumper cover 8 is a cover member made of a resin such as polypropylene provided so as to cover the components of the bumper 2, and configures the appearance of the bumper 2.

  The chamber member 5 is a hollow member made of low density polyethylene (LDPE) that is disposed in the bumper 2 above the front surface of the bumper force 10 and extends in the vehicle width direction. The hollow portion of the chamber member 5 is a chamber space 4.

  More specifically, as shown in FIGS. 3 and 4, the chamber member 5 includes a main body portion 11 that extends in the vehicle width direction and has a chamber space 4 formed therein, and extends from the main body portion 11. It consists of two extending portions 12 and one extending portion 13 communicating with the chamber space 4. The extending portions 12 and 13 are each integrally formed with the main body portion 11 by blow molding.

  The extending portion 12 is a portion formed for attaching the pressure sensor 6, and as shown in FIGS. 1 and 3, at two places on the left side and the right side across the center in the vehicle width direction of the chamber member 5, The upper surface of the main body 11 extends upward from the bumper force 10. Each of the two extending portions 12 has an opening 12a formed on the upper surface thereof, and the pressure sensor 6 is attached in a state where the pressure introducing pipe 6a is inserted into the opening 12a. The two pressure sensors 6 are provided to ensure redundancy in collision detection.

  The extending portion 13 is a portion formed for attaching the insert bracket 21 and the filter member 31, and extends from the upper surface of the main body portion 11 at the center in the vehicle width direction of the main body portion 11 as shown in FIGS. 1 and 4. It is installed. An insert bracket 21 having a breathing hole 23 is attached to the rear surface of the extended portion 13 on the vehicle rear side by insert molding.

  The insert bracket 21 is a polybutylene terephthalate (PBT) member having a breathing hole 23, and a filter member 31 is attached to the insert bracket 21. The chamber space 4 is always at atmospheric pressure because it communicates with the outside air without being sealed by the breathing hole 23 of the insert bracket 21. As a result, it is possible to prevent a difference in atmospheric pressure from occurring due to a difference in altitude or a change in temperature in the chamber space 4, and the vehicle collision detection device 1 can detect a collision without being affected by a change in altitude or temperature. ing. Note that the breathing hole 23 is a small hole having a diameter of several millimeters, and the chamber space 4 can be regarded as a substantially sealed state when a sudden pressure change in the chamber space 4 due to a collision is detected.

  In more detail, the insert bracket 21 is comprised from the cylinder part 22, the flange part 24, and the umbrella part 25, as shown in FIGS.

  The cylindrical portion 22 is formed in a cylindrical shape having a breathing hole 23 in the center, and the filter member 31 is inserted and fitted from the vehicle rear side.

  The flange portion 24 is formed in a bowl shape on the vehicle front side of the cylindrical portion 22 and is a portion that is insert-molded when the chamber member 5 is blow-molded as shown in FIG. In blow molding, since the thickness is reduced as the distance from the parting line increases, the mating surface of the mold 101 on the vehicle front side and the mold 102 on the vehicle rear side is located near the rear surface of the chamber member 5 on the vehicle rear side. By providing the parting line (PL), the thickness of the portion where the flange portion 24 of the insert bracket 21 is inserted can be increased. Thereby, the insert bracket 21 is firmly fixed without inhibiting the deformation of the chamber member 5 at the time of the collision.

  The umbrella part 25 is a circular arc-shaped part having an open lower surface provided on the outer peripheral side of the cylindrical part 22, and extends from the rear part of the flange part 24 to cover the upper side of the cylindrical part 22 like a bag.

  The filter member 31 is attached to the cylindrical portion 22 of the insert bracket 21 in which the breathing hole 23 is provided, and prevents water and foreign matter from entering the chamber member 5 while ensuring air permeability.

  More specifically, as shown in FIGS. 5, 6, and 7, the filter member 31 includes a support body 32, a gas permeable membrane 33, and a cover 34.

  The support body 32 is a cylindrical member made of a thermoplastic elastomer, and covers the cylindrical portion 22 of the insert bracket 21 using elasticity.

The gas permeable membrane 33 is a polytetrafluoroethylene (PTFE) porous membrane capable of preventing air from entering while ensuring ventilation, and is formed in a circular sheet shape. The porous PTFE membrane is obtained by biaxially stretching a PTFE sheet to obtain a porous structure, and depending on the stretching ratio, an air flow rate of 50 to 1500 [cm ³ / min] and a water resistance of about 1 to 100 [kPa] are obtained. be able to. Since the two are contradictory characteristics, an appropriate characteristic is selected by experiment. The gas permeable membrane 33 is bonded to the opening edge on one end side of the support 32 by an adhesive.

  The cover 34 is a cap-shaped member made of polypropylene. The cover 34 is placed on one end of the support 32 where the gas permeable membrane 33 is provided to cover the gas permeable membrane 33 and form an opening between the support 32. That is, the cover 34, the support body 32, and the gas permeable membrane 33 are not in close contact except for a part, and air can enter and exit as indicated by arrows in FIG. A ventilation path having a labyrinth structure is formed between the opening and the ventilation film 33.

  The bumper absorber 9 is disposed below the front surface of the bumper force 10 and below the chamber member 5, and is a member responsible for shock absorption in the bumper 2. As the bumper absorber 9, for example, foamed polypropylene or the like can be suitably used.

  The bumper force 10 is a metal beam-like member such as aluminum that is disposed in the bumper 2 and extends in the vehicle width direction, and is formed at the front end of the side member 15 that is a pair of metal members that extend in the vehicle front-rear direction. It is attached.

  The pressure sensor 6 is a sensor device that can detect a change in gas pressure, outputs a signal proportional to the pressure, and is electrically connected to the pedestrian protection device ECU 7 via a signal line 7a. As described above, the pressure sensor 6 is attached to the chamber member 5 in the extending portion 12 and is configured to be able to detect a change in pressure of air in the chamber space 4.

  The vehicle speed sensor 16 is an existing speed sensor that detects the traveling speed of the vehicle, and is electrically connected to the pedestrian protection device ECU 7 via the signal line 7a.

  The pedestrian protection device ECU 7 is an electronic control device that is connected to the pressure sensor 6 and performs start-up control of the pedestrian protection device 3 disposed in the vehicle body, and a signal output from the pressure sensor 6 is a signal line. It is configured to be input via 7a. The pedestrian protection device ECU 7 executes a process of determining whether or not a pedestrian (ie, a human body) has collided with the vehicle bumper 2 based on the pressure detection result of the pressure sensor 6 and the vehicle speed detection result of the vehicle speed sensor 16. To do. When the pedestrian protection device ECU 7 determines that a pedestrian collision has occurred, the pedestrian protection device ECU 7 outputs a signal to the pedestrian protection device 3 to activate the pedestrian protection device 3.

  As the pedestrian protection device 3, known devices called by names such as a pop-up hood, a pop-up engine hood, an active bonnet, an active hood, a cowl airbag, and a hood airbag can be adopted. The pedestrian protection device 3 raises the rear end of the engine hood instantaneously after collision detection and increases the clearance to increase the absorption stroke of the hood itself, so that the pedestrian (particularly the head) can be a hard member such as an engine. The possibility of collision can be reduced.

Next, detection of a collision by the vehicle collision detection apparatus 1 of the first reference example will be described. When a pedestrian collides with the bumper 2 of the vehicle, the body (mainly the leg) of the pedestrian presses the bumper 2, presses the chamber member 5 through the bumper cover 8, and the chamber member 5 is pressed. The part is deformed and crushed. The gas pressure in the chamber space 4 increases due to the deformation of the chamber member 5. This increase in pressure is detected by the pressure sensor 6 attached to the extending portion 12, and an output signal is sent to the pedestrian protection device ECU 7 via the signal line 7a. And pedestrian protection apparatus ECU7 performs the process which discriminate | determines whether the pedestrian (namely, human body) collided with the bumper 2 based on the pressure detection result.

  As is apparent from the above description, the vehicle collision detection apparatus 1 includes a chamber body 11 that is disposed in front of the bumper force 10 in the vehicle bumper 2 and has a chamber space 4 formed therein. An apparatus comprising a member 5 and a pressure sensor 6 for detecting a pressure in the chamber space 4, and configured to detect a collision with the vehicle bumper 2 based on a pressure detection result by the pressure sensor 6. The member 5 has a breathing hole 23 that allows the chamber space 4 to communicate with the outside, and a filter member 31 is attached to the breathing hole 23.

  According to this configuration, since the filter member 31 is attached to the breathing hole 23, it is possible to prevent entry of foreign matter into the chamber member 5 while ensuring air permeability. For example, even if the vehicle travels on a rough road or a road flooded with muddy water, the filter member 31 can prevent muddy water from entering, so the breathing hole 23 is not blocked by sand or mud. Further, insects and spiders do not enter from the breathing hole 23, and the breathing hole 23 is not blocked by the nesting. Therefore, the breathing function of the breathing hole 23 is ensured, and highly reliable collision detection can be performed.

  The breathing hole 23 is provided on the back side of the chamber member 5. According to this configuration, even if the breathing hole 23 is submerged by traveling on a flooded road, the respiratory function can be reliably ensured because there is little water exposure from the front. Moreover, when the back surface side of the chamber member 5 runs on an icy and snowy road, it is possible to reduce the possibility that snow or the like adheres.

  An insert bracket 21 having a breathing hole 23 is attached to the chamber member 5, and a filter member 31 is attached to the chamber member 5 via the insert bracket 21. Even if the chamber member 5 is formed of a soft material such as low density polyethylene having low adhesiveness, the filter member 31 can be firmly fixed through the hard insert bracket 21. In particular, the insert bracket 21 is easily and reliably fixed by being insert-molded into the flexible chamber member 5.

  The insert bracket 21 includes an umbrella portion 25 that covers at least the upper portion of the filter member 31. According to this configuration, even when a small amount of water is splashed with water splash or the like, it is possible to prevent water from entering the filter member 31.

  The chamber member 5 includes an extending portion 13 that extends from the main body 11 and communicates with the chamber space 4 inside. The breathing hole 23 is provided in the extending portion 13. According to this configuration, since the breathing hole 23 is provided in the insert bracket 21 provided in the extending portion 13, the collision can be accurately detected without hindering the deformation of the chamber member 5 at the time of the collision. . In particular, since the extending portion 13 is provided on the upper surface of the chamber member 5, the breathing hole 23 can be provided without requiring special processing on the bumper force 10 side adjacent to the vehicle rear side.

  Further, the filter member 31 has a gas permeable membrane 33 that can prevent water from entering while ensuring ventilation. According to this configuration, muddy water and insects can be prevented from entering the chamber member 5, the function of the breathing hole 23 can be ensured, and highly reliable collision detection can be performed. Furthermore, since it is possible to prevent water from entering, there is no concern that the water that has entered inside freezes. In particular, since the gas permeable film 33 is a polytetrafluoroethylene porous film, the gas permeable film is excellent in water repellency, heat resistance, and chemical resistance. Moreover, a porous film can be easily created by biaxial stretching, and by changing the stretching ratio, the air flow rate and water resistance, which are contradictory properties, can be made to some extent.

  The filter member 31 further includes a support 32 that supports the gas permeable membrane 33, and a cover 34 that covers the gas permeable membrane 33 and forms an opening 35 between the support 32 and the cover 34. The support 32 forms a ventilation path with a labyrinth structure between the opening 35 and the ventilation film 33. According to this configuration, it is possible to prevent the air-permeable membrane 33 from being damaged due to the collision of large foreign matters such as sand and pebbles, and it is difficult for moisture to enter the filter member 31 by the air passage of the labyrinth structure.

Further, since the filter member 31 is provided at the rear of the vehicle with respect to the front surface of the bumper force 10, the structure is such that deformation of the chamber member 5 due to a collision does not directly affect the filter member 31 and does not easily fall off.
( Embodiment )
In the first reference example , the breathing hole 23 is provided on the back surface of the extending portion 13. However, in the embodiment of the present invention, as shown in FIG. 9, the extending portion 13 for the breathing hole is not provided. , the configuration of providing the back of the main body portion 11. In this case, to form the openings by performing a hole formation at a position away from the left and right ends of the front surface of the bumper reinforcement 10, arranged a filter member 31 through the opening hole. In this embodiment , since it is not necessary to provide the extended part 13 for breathing holes in the chamber member 5, the chamber member 5 becomes a simpler shape.
(Second reference example)
In the first reference example , the breathing hole 23 is provided on the back surface of the extending portion 13, but the extending portion 13 has the same shape as the extending portion 12 for the pressure sensor 6 as shown in FIG. A breathing hole 23 may be provided on the upper surface. According to this modification, since the breathing hole 23 is provided on the upper surface of the extending portion 13, the attachment position of the filter member 31 can be shifted rearward of the vehicle, and the degree of freedom in arrangement is improved.
(Third reference example)
In the first reference example , the extended portion 13 is provided above the main body portion 11. However, as shown in FIG. 11, the extended portion 13 is provided at an end portion of the main body portion 11 in the vehicle width direction to breathe. The hole 23 and the filter member 31 may be provided. Normally, the chamber member 5 has substantially the same vehicle width direction dimension as that of the bumper force 10, but in the modified example shown in FIG. 11, the front portion of the bumper force 10 is formed on the main body 11 on the left side of the vehicle. The extending portion 13 is provided at a portion protruding from the bumper force 10 toward the vehicle side. In FIG. 11, the illustration of the bumper cover 8 is omitted. Further, in the modification shown in FIG. 11, the example in which the extending portion 13, the breathing hole 23, and the filter member 31 are provided on the left side of the vehicle is shown.

According to this reference example, the extended portion 13 is provided on the side of the vehicle with respect to the end portion in the vehicle width direction of the bumper force 10, so that the bumper force 10 can be disposed without requiring processing. . Further, the collision can be detected with high accuracy without hindering the deformation of the chamber member 5 at the time of the collision.

  Note that the present invention is not limited to the above-described embodiment, and it is needless to say that various modifications can be made without departing from the gist of the present invention.

  Although the filter member 31 is bonded to the support 32 with an adhesive, the filter member 31 may be bonded by a double-sided tape, heat welding, or ultrasonic welding.

  Moreover, although the chamber member 5 showed the example which employ | adopted the low density polyethylene as a material, you may use another material. Further, the chamber member 5 may not be formed integrally.

  Further, since the low density polyethylene used for the chamber member 5 has low adhesiveness, the filter member 31 is attached to the chamber member 5 via the insert bracket 21. However, a good adhesive that can guarantee the adhesive force is obtained. If the chamber member 5 can be made of another material, the gas permeable membrane 33 of the filter member 31 or the like may be directly attached to the chamber member 5 without providing the insert bracket 21.

DESCRIPTION OF SYMBOLS 1 Vehicle collision detection apparatus 2 Bumper 4 Chamber space 5 Chamber member 6 Pressure sensor 10 Bumper force 11 Main-body part 12 Extension part (for pressure sensors)
13 Extension (for breathing holes)
21 Insert bracket 23 Breathing hole 31 Filter member

Claims (2)

A chamber member (5) having a chamber body (11) disposed in front of the bumper force (10) in the vehicle bumper (2) and having a chamber space (4) formed therein, and attached to the chamber member And a pressure sensor (6) for detecting a pressure in the chamber space (4), and configured to detect a collision with the vehicle bumper based on a pressure detection result by the pressure sensor. In device (1):
The chamber member has a breathing hole (23) that allows the chamber space to communicate with the outside at a position separated from the position where the pressure sensor is attached in the vehicle width direction. The breathing hole includes a filter member (31). )
The breathing hole is provided on a back surface of the chamber member;
The back surface of the chamber member provided with the breathing hole is in contact with the bumper force,
The filter member includes a gas permeable membrane (33) capable of preventing air intrusion while ensuring ventilation, a support (32) supporting the gas permeable membrane, and covering the gas permeable membrane and between the support. A cover member (34) for forming an opening, wherein the cover member and the support form a ventilation path of a labyrinth structure between the opening and the ventilation film, and the front surface of the bumper force A collision detection apparatus for a vehicle, wherein the vehicle collision detection device is provided behind the front surface of the bumper force through an opening formed at a position away from left and right ends of the vehicle. A bracket member (21) having the breathing hole is attached to the chamber member,
The filter member is attached to the chamber member via the bracket member,
The collision detection apparatus for a vehicle according to claim 1, wherein the bracket member includes an umbrella portion (25) that covers at least an upper portion of the filter member.

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