JPH05330399A - Impact sensor mounting structure in vehicle - Google Patents

Abstract

PURPOSE:To shorten a span of impact detection time by attaching a sensor case to a car body via an impact absorbing means which absorbs an impact in a sense along the traveling direction of sensing mass being produced in the sensor case in time of a car crash. CONSTITUTION:Even if an impact sensor 14 is installed in the vicinity of a collisional part in a vehicle and sudden deceleration (acceleration) is produced in this part in time of a car crash, any impact in a sense along the traveling direction of sensing mass 20 being added to a sensor case 16 from a car body is absorbed by an impact absorbing means 36. Therefore such a fear that suddenly variable deceleration (acceleration) is produced in the sensor case 16 in a short time is preventable from occurring, thus a contact part 22 is prevented from being vibrated piecemeal as well as this contact part 22 can be prevented from being turned on or off bit by bit.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle collision sensor mounting structure, and more particularly, to a vehicle body mounting structure for a sensor case that holds a contact portion that is brought into contact with a sensing mass moved during a vehicle collision. Regarding improvement.

[0002]

2. Description of the Related Art Conventionally, for example, an automobile is known to be equipped with an airbag device in order to ensure the safety of passengers in the event of a vehicle collision. The airbag device protects the occupant by preventing a secondary collision of an occupant by inflating the airbag at the time of a vehicle collision, and the airbag device is provided with a collision sensor for detecting a vehicle collision. There is.

This collision sensor is generally a mechanical one having a sensing mass as a moving contact and a contact portion as a fixed contact. The sensing mass is always held at a predetermined position on the vehicle by a spring, a magnet, or the like, and moves in a predetermined direction due to inertia when a deceleration (acceleration) greater than a predetermined value occurs at the vehicle part at the position where the sensing mass is held at the time of a vehicle collision. Is configured to. on the other hand,
The contact portion is held at a front position in the moving direction of the sensing mass by a sensor case attached to the vehicle body,
It is configured to be conducted by contacting with the sensing mass that has moved during a vehicle collision. Further, the normal sensing mass is housed in the sensor case together with the contact portion, and is configured to move in the sensor case in the event of a vehicle collision. When the contact portion comes into contact with the sensing mass and becomes conductive, a signal is output from the collision sensor, and the gas generator is activated by this output signal to generate a predetermined gas,
The generated gas inflates the airbag (Japanese Utility Model Laid-Open No. 2-10159).

[0004]

By the way, it is desirable that the collision detection time of the collision sensor is shorter. For example,
If the collision detection time of the collision sensor used in the airbag device can be shortened, the inflation time of the airbag can be lengthened accordingly, and the increase in the air pressure in the passenger compartment due to the inflation of the airbag can be moderated. There are advantages.

The collision detection time of the collision sensor is set such that the collision sensor is provided close to the collision area of the vehicle (the area where the vehicle first comes into contact with the collision object), for example, in the case of detecting a head-on collision of the vehicle. It becomes possible to shorten by providing the front end portion of the front frame. That is, when the collision sensor is provided close to the collision area of the vehicle, compared with the case where the collision sensor is provided away from the collision area of the vehicle, the collision sensor is provided with a predetermined value or more in a short time after the collision of the vehicle. Since deceleration occurs, the time for the sensing mass to start moving is shortened, and thus the time from the collision of the vehicle to the contact between the sensing mass and the contact portion can be shortened.

However, there is a problem in providing the collision sensor near the collision site of the vehicle. Conventionally, since the sensor case is firmly fixed to the vehicle body, if the sensor case is provided near the collision site of the vehicle, a strong impact will be generated on the sensor case via the mounting portion to the vehicle body. In that case, deceleration or acceleration (high-frequency G) that fluctuates drastically in a short time occurs in the sensor case, and the contact part held in the sensor case vibrates in small steps, and the conduction of the contact part decreases in small steps. Since it is turned on / off, it becomes difficult to output a stable signal.

In view of the above problems, the present invention provides a vehicle collision sensor mounting structure capable of outputting a stable collision detection signal even if a collision sensor is provided near the collision site in order to shorten the collision detection time. The purpose is to provide.

[0008]

In order to solve the above-mentioned problems, a vehicle collision sensor mounting structure according to the present invention is always held at a predetermined position of the vehicle, and in the case of a vehicle collision, it is separated from the predetermined position due to inertia and moves in a predetermined direction. A moving sensing mass, and a contact portion held by a sensor case attached to the vehicle body at a position ahead of the predetermined position in the moving direction of the sensing mass and brought into contact by contact with the sensing mass moved at the time of a vehicle collision. A structure for mounting a collision sensor provided on a vehicle body, wherein the sensor case comprises:
It is characterized in that it is attached to a vehicle body via an impact mitigating means for mitigating impact in a direction along the moving direction of the sensing mass generated in the sensor case at the time of vehicle collision.

The shock absorbing means can be made of elastic rubber.

Further, the shock absorbing means can be constituted by a mounting bracket having a wave-like deformed portion so as to be easily deformed by an impact at the time of a vehicle collision.

[0011]

According to the above construction, the collision sensor is provided near the collision area of the vehicle, and even if a sudden deceleration (acceleration) is generated at the collision area of the vehicle, the sensing mass added from the vehicle body to the sensor case. Since the shock in the direction along the moving direction of the sensor is mitigated by the shock mitigating means, it is possible to prevent the sensor case from undergoing a rapidly fluctuating deceleration (acceleration), which makes the contact part smaller. It is possible to prevent vibration and prevent the contact part from being turned on / off in small steps.

As described above, according to the vehicle collision sensor mounting structure of the present invention, since the sensor case is mounted on the vehicle body through the shock absorbing means, even if the collision sensor is provided in the vicinity of the collision site of the vehicle, the contact point can be contacted. Partial conduction is small O
It is possible to prevent the N / OFF, and thus it is possible to shorten the collision detection time of the collision sensor and to output a stable collision detection signal.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a vehicle collision sensor mounting structure according to the present invention will be described below with reference to the accompanying drawings.

First, a first embodiment of a vehicle collision sensor mounting structure according to the present invention will be described. 1 is an external perspective view of a vehicle body of an automobile, FIG. 2 is an enlarged perspective view of a portion A in FIG. 1, FIG. 3 is a view in the direction of arrow B in FIG. 2 showing a mounting state of a collision sensor, and FIG. FIG. 4 is a cross-sectional view taken along line IV-IV in FIG. 3 showing a configuration of a vehicle collision sensor mounting structure according to an embodiment.

The vehicle collision sensor mounting structure according to this embodiment shown in the drawings applies the present invention to a vehicle body mounting structure of a collision sensor used in an automobile air bag device. The left front end portion (A portion) of the vehicle body 2 shown in FIG. 1 is, as shown in FIG. 2, a front frame 4 extending rearward from the vehicle body front end portion, a side panel 6 joined to the front frame 4, and the side. The shroud panel 8 is joined to the panel 6, and the side panel 6 is provided with a tie-down hook 10, a bumper bracket 12, and the like.

The collision sensor 14, as shown in FIG.
It is attached to the side panel 6 side at the joint between the front frame 4 and the side panel 6. As shown in FIG. 4, the collision sensor 14 includes a sensor case 16, a sensing mass 20 held in the sensor case 16 at a predetermined position by a magnet 18, and the sensor case 16 held at a predetermined position in the figure. And a contact portion 22.

The sensing mass 20 is always held at the predetermined position by the magnet, but if a deceleration more than a predetermined value is generated in the collision sensor 14 during a vehicle collision (a head-on collision), the sensing mass 20 is moved from the predetermined position by the illustrated position. It is configured to move away to the left in the drawing (front of the vehicle body) and come into contact with the contact portion 22. On the other hand, the contact portion 22 is configured to be conductive by coming into contact with the moved sensing mass 20, and when the contact portion 22 is conductive, the contact portion 2
A collision detection signal is output via an electric wire 24 (see FIG. 3) connected to the No. 2, and an airbag (not shown) is deployed in the vehicle compartment by the output signal. A spring may be used instead of the magnet 18 to hold the sensing mass 20 at a predetermined position.

A mounting bracket 26 is fixed to the sensor case 16, and a bolt 28 and a nut 30 are mounted on both ends of the mounting bracket 26, respectively. Further, the bolts 32 and the nuts 34 are also attached to the predetermined positions of the side panel 6 shown in the figure. And
An elastic rubber 36 is interposed between the bolts 28 and 32 as a shock absorbing means for absorbing a shock applied to the sensor case 16 in the vehicle front-rear direction, that is, a direction along the moving direction of the sensing mass 20 at the time of a vehicle collision. ing. That is, the sensor case 16 is attached to the vehicle body via the elastic rubber 36, and the impact applied to the collision sensor 14 at the time of a vehicle collision is mitigated by the elastic rubber 36 (this will be described later).

The mounting bracket 26 may be attached to the sensor case 16 by extending the mounting bracket 26 in the vertical direction as shown in FIG. 5 unless the direction of the collision sensor 14 with respect to the vehicle body is changed. .. Here, FIG. 5 is a view showing another mounting state of the collision sensor.

Next, a second embodiment of the vehicle collision sensor according to the present invention will be described. FIG. 6 is a view showing a structure of a vehicle collision sensor mounting structure according to a second embodiment of the present invention, IV in FIG.
It is a figure equivalent to the IV line sectional view. In this embodiment, the same elements as those in the first embodiment are designated by the same reference numerals and the description thereof will be omitted.

A feature of the vehicle collision sensor mounting structure according to the illustrated embodiment is that the sensor case 16 is mounted on the vehicle body (side panel 6) through a mounting bracket 26 'as a shock absorbing means. That is, as shown in FIG. 6, the mounting bracket 2 is attached to the sensor case 16.
6'is fixed, and both ends of the mounting bracket 16 are fixed to the side panel 6 by bolts 38 and nuts 40. The mounting bracket 26 'has a deformed portion 42 formed in a wave shape so as to be easily deformed by an impact at the time of a vehicle collision, in the vehicle body front-rear direction (lateral direction in the drawing) of the sensor case 16, that is, in the moving direction of the sensing mass 20. It is formed on both sides along the direction. The impact applied to the sensor case 16 at the time of a vehicle collision is mitigated by the deformation of the deformable portion (this will be described later).

Next, a third embodiment of the vehicle collision sensor mounting structure according to the present invention will be described. FIG. 7 is a view corresponding to a sectional view taken along line IV-IV in FIG. 3 showing a structure of a vehicle collision sensor mounting structure according to a third embodiment of the present invention. In the present embodiment, the same elements as those in the first and second embodiments are designated by the same reference numerals and the description thereof will be omitted.

The characteristic of the vehicle collision sensor mounting structure according to the present embodiment shown in the figure is that an elastic rubber 44 as an impact absorbing means is mounted on the outer peripheral portion of the sensor case 16, and the sensor case 16 is mounted on the vehicle body via the elastic rubber 44. It is attached to (side panel 6). That is, as shown in FIG. 6, the elastic rubber 44 is attached to the outer peripheral portion of the sensor case 16 so as to cover the sensor case 16,
The sensor case 16 includes two upper and lower members 26 "a, 26".
It is held so as to be sandwiched by an elastic rubber 44 by a mounting bracket 26 ″ composed of b.
Both end portions of are fixed to the side panel 6 with bolts 38 and nuts 40, respectively. The impact applied to the sensor case 16 at the time of a vehicle collision is mitigated by the elastic rubber 44 (this will be described later).

The attachment of the mounting bracket 26 "to the sensor case 16 is performed by the collision sensor 14
If the direction with respect to the vehicle body is not changed, the mounting method as shown in FIG. 5 may be used as in the first embodiment.

Next, the operation of the vehicle collision sensor mounting structure according to each of the above-described embodiments at the time of vehicle collision will be described with reference to FIG. FIG. 8 is a diagram showing a change in deceleration with time in a sensor case at the time of a vehicle collision. FIG. 8A shows a case where a collision sensor is provided away from a collision portion of a vehicle body by a conventional mounting structure. (A) shows the case where the collision sensor is provided near the collision site of the vehicle body by the conventional mounting structure, and (c) of the figure shows the case where the collision sensor is provided near the collision site of the vehicle body by the mounting structure according to the present invention.

As shown in FIG. 8 (a), a conventional mounting structure, that is, a shock absorbing means is not provided between the sensor case and the vehicle body as in the present invention, and the sensor case is firmly fixed to the vehicle body. Due to the mounting structure, when the collision sensor is provided away from the collision site of the vehicle body, the sensor case is not subjected to a sudden impact, and the deceleration occurring in the sensor case changes gently. However, it takes a long time Tc from when the collision area of the vehicle comes into contact with the collision object to when the deceleration of the predetermined value Gc or more occurs in the sensor case. Therefore, the sensing mass starts moving slowly and the sensing mass contacts the contact portion. It takes a long time to come into contact with the collision detection time.

Further, as shown in FIG. 8B, when the collision sensor is provided near the collision area of the vehicle body by the conventional mounting structure, the collision area of the vehicle comes to a predetermined position after the collision area contacts the collision object. The time Tc required until deceleration equal to or greater than the value Gc occurs is short, so that the sensing mass starts moving quickly and the time until the sensing mass contacts the contact portion is shortened. However, since the sensor case is firmly fixed to the vehicle body, a severe impact is applied to the sensor case, and the deceleration generated in the sensor case greatly changes in a short time such that the acting direction is reversed. Therefore, even if the contact part held in the sensor case vibrates in small steps, even if the sensing mass comes into contact with the contact part once, the continuity of the contact part is turned on / off in small steps and a stable collision detection signal is output. It becomes difficult to do.

On the other hand, in the vehicle collision sensor mounting structure according to the above embodiments of the present invention, the sensor case 1
Since the respective 6 are attached to the vehicle body via the impact absorbing means, even if the collision sensor 14 is provided near the collision area of the vehicle body, the impact applied to the sensor case 16 at the time of the vehicle collision is mitigated by the impact absorbing means. The deceleration generated in the sensor case 16 does not fluctuate greatly but changes gently. Therefore, the sensing mass 20 and the contact portion 22 can be stably contacted for a predetermined time, the conduction of the contact portion 22 is prevented from being turned ON / OFF in small steps, and the collision detection signal is stably output. It becomes possible. Moreover, since the time Tc at which the sensing mass 20 starts to move is short, it is possible to shorten the collision detection time.

Although the embodiment of the vehicle collision sensor mounting structure according to the present invention has been described above, the vehicle collision sensor mounting structure according to the present invention is not limited to this mode.

For example, each of the above embodiments relates to a collision sensor mounting structure for detecting a head-on collision of an automobile. The vehicle collision sensor mounting structure according to the present invention is a collision sensor for detecting a side collision or a rear collision of a vehicle. It can also be applied to the mounting structure of.

[Brief description of drawings]

FIG. 1 is an external perspective view of an automobile body

FIG. 2 is an enlarged perspective view of part A in FIG.

FIG. 3 is a view on arrow B in FIG. 2 showing a state in which a collision sensor is attached.

FIG. 4 is a sectional view taken along the line IV-IV in FIG. 3 showing the structure of the vehicle collision sensor mounting structure according to the first embodiment of the present invention.

FIG. 5 is a view showing another mounting state of the collision sensor.

FIG. 6 is a view corresponding to a sectional view taken along line IV-IV in FIG. 3 showing a structure of a vehicle collision sensor mounting structure according to a second embodiment of the present invention.

FIG. 7 is a view corresponding to a sectional view taken along line IV-IV in FIG. 3 showing a structure of a vehicle collision sensor mounting structure according to a third embodiment of the present invention.

FIG. 8 is a diagram showing changes over time in deceleration occurring in the sensor case during a vehicle collision.

[Explanation of symbols]

 6 Side Panel (Car Body) 14 Collision Sensor 16 Sensor Case 18 Magnet 20 Sensing Mass 22 Contact Point 26, 26 ', 26 "Mounting Bracket 36, 44 Elastic Rubber 42 Deformation Section

Claims (3)

[Claims] 1. A sensing mass that is normally held at a predetermined position of a vehicle and moves in a predetermined direction away from the predetermined position due to inertia when a vehicle collides, and a sensing case attached to a vehicle body causes the sensing mass to move beyond the predetermined position. A structure for mounting a collision sensor on a vehicle body, which is held at a front position in the moving direction of the vehicle, and which is brought into contact with the sensing mass moved at the time of the vehicle collision, the sensor case being attached to the vehicle body at the time of the vehicle collision. A collision sensor mounting structure for a vehicle, wherein the collision sensor mounting structure for a vehicle is mounted on a vehicle body through a shock absorbing means for relaxing an impact in a direction along a moving direction of the sensing mass generated in the sensor case. 2. The vehicle collision sensor mounting structure according to claim 1, wherein the impact absorbing means is made of elastic rubber. 3. The vehicle according to claim 1, wherein the shock absorbing means is constituted by a mounting bracket having a wavy deformable portion that is easily deformed by an impact at the time of a vehicle collision. Collision sensor mounting structure.