JP2511213Y2 - Vehicle occupant protection device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention relates to a vehicle occupant protection device mounted on a steering wheel of a vehicle.

(Prior Art) Conventionally, a switch mechanism has been used as a collision detection sensor used in a vehicle occupant protection device that protects an occupant from an impact by inflating an airbag when an acceleration of a predetermined value or more is applied during a vehicle collision. There is known a mercury sensor in which mercury particles are stored in a container having (for example, Japanese Utility Model Laid-Open No. 1-40141). This mercury sensor is usually mounted on a vehicle with a certain angle of inclination with respect to the horizontal direction so that the mercury particles do not come into contact with the switch. It overcomes and moves in the container to close the switch.

(Problems to be solved by the invention) By the way, although such a mercury sensor is lightweight and compact, when it is installed in a steering wheel of a vehicle, the position of mercury particles in the mercury sensor varies depending on the rotational position of the steering wheel. There may be variations in the detection of collisions. Therefore, conventionally, this mercury sensor has been arranged on the vehicle body side.

However, as a vehicle occupant protection device for the purpose of downsizing and cost reduction, it is preferable to mount components of all devices including an airbag in a steering wheel, and it is possible to collide with the vehicle in the conventional manner. Arranging only the detection sensor on the vehicle body side has hindered downsizing and cost reduction of the device.

The present invention has been made in view of the above circumstances, and provides a vehicle occupant protection device in which a mercury sensor as a collision detection sensor can be mounted in a steering wheel of a vehicle, which can be made compact and low cost. The purpose is to

(Means for Solving the Problems) In order to solve the above problems, the present invention provides a vehicle occupant protection device including a collision detection sensor disposed on a steering wheel of a vehicle, wherein the collision detection sensor is made of a conductive material. A housing made of a conductive member containing a weight,
An electrode disposed in the housing via an insulating member, the electrode being disposed along the central axis of the housing, and the central axis of the housing being substantially parallel to the axis of the steering shaft. The steering wheel is mounted on the steering wheel, and the weight moves to electrically connect the housing and the electrode when an acceleration of a predetermined value or more is applied to the vehicle.

(Operation) Since the electrode of the collision detection sensor is arranged along the central axis of the housing and the central axis is arranged parallel to the axis of the steering shaft, the position of the weight changes even if the steering wheel is rotated. Absent.

Embodiment An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is an exploded perspective view showing the overall structure of a vehicle occupant protection system according to an embodiment of the present invention.

In the drawing, reference numeral 1 denotes a steering wheel, and a housing case 3 for housing and fixing a protective device main body 2 is provided at a central portion of the steering wheel 1, and a female screw 4 and left and right through holes are provided at a bottom portion of the housing case 3. 5, 5, a central through hole 6 and an opening 7 are provided respectively.

The protective device main body 2, the inflator 8 and the retainer 9 are sequentially accommodated in the accommodating case 3 and fixed with bolts (not shown). A nylon airbag 10 is folded and accommodated in the retainer 9 to cover the airbag 10. As described above, the urethane cover 11 is attached to the retainer 9.

The protective device main body 2 includes a gas dump sensor 12, a mercury sensor (collision detection sensor) 13, a drive signal supply battery 14, a stabilizing capacitor 15, an indicator 16, and a circuit unit.
17 are integrated together. From the circuit unit 17, a male portion 18a of a short coupler 18 described later and a battery power supply connector 19 extend.

The steering wheel 1 to which the protection device is attached is attached to a column 21 via a slip ring 20. A coupler 22 to which the female portion 18b of the short coupler 18, the battery power connector 19 and another connector (not shown) such as a horn switch are connected to the rotary plate 20a of the slip ring 20.
Attach the rotating plate 20a to the steering wheel 1
A pair of attachment members 23, 23 are provided. The female portion 18b of the short coupler 18 has a structure in which both terminals thereof are short-circuited to each other, and is adhered to the surface of the rotary plate 20a by adhesion or the like. On the other hand, the coupler 22 is connected to the battery 26 (FIG. 2) via the wiring on the back side of the rotating plate 22a.

The steering wheel 1, together with the protective device, is attached to the column 21 via the slip ring 20 as described below.

First, attach the steering wheel 1 to the mounting members 23, 23.
To the through holes 5, 5 and the steering wheel shaft 24
Is inserted into the central through hole 6, the couplers 22 and 18b are inserted into the opening 7, and then the tip of the steering wheel shaft 24 is fastened with a screw (not shown) so as to be coupled with the slip ring 5 and the column 21. Attach to. Next, the connector extending from the unit 17 of the protective device main body 2
After connecting 19 and other connectors to the coupler 22 in the opening 7, the male portion 18a of the short coupler 18 extending from the unit 17 is connected to the female portion 18b of the short coupler in the opening 7. Then, the protector main body 2, the inflator 8, the airbag 10, and the retainer 9 to which the cover 11 is previously mounted are sequentially housed in the housing case 3 of the steering wheel 1 to mount the protective device on the steering wheel 1.

FIG. 2 is a circuit diagram showing a configuration of an electric part of the passenger protection device.

An ignition switch 27 and a fuse 28 are connected in series to a positive electrode of a battery 26 mounted on a vehicle of the vehicle body side circuit 1, and an output side end of the fuse 28 is connected to the steering wheel via the slip ring 20. The side circuit 29 is connected.

An input end of the steering wheel side circuit 29 is connected to a drive circuit 32 and a CPU 33 as a monitor circuit via diodes 30 and 31, respectively.

The drive circuit 32 is a circuit for supplying a drive signal to the squib 37 built in the inflator 8 in the event of a vehicle collision, and the drive circuit 32 has a battery 14 (for example, a lithium battery) as a drive signal supply power source. It is incorporated. The battery
A short coupler 18 is connected to the positive electrode of 14, and a diode 34, a mercury sensor 13, a squib 37, and a gas dump sensor 12 are connected in series in this order to the short coupler 18. In addition, a stabilizing capacitor 15 is connected in parallel with the battery 14 via a short coupler 18.

The short coupler 18 is the male part on the circuit side as described above.
18a and a female part 18b on the column side of the vehicle.
By connecting a and 18b, the battery 14 is connected to the circuit.

The mercury sensor 13 and the gas dump sensor 12 are acceleration sensors provided as a sub sensor and a main sensor, respectively. As shown in FIG. 3, the mercury sensor 13 is a housing 1 made of a conductive member in which mercury (weight) 13a is enclosed.
3b and an electrode 13d arranged on the central axis of the housing 13b via an insulating member 13c. The housing 13b has a substantially cylindrical shape that is symmetrical with respect to the electrode 13d on the central axis thereof. The mercury sensor 13 is attached to the protective device main body 2, and when the protective device main body 2 is mounted on the steering wheel 1, the central axis of the housing 13b is substantially parallel to the axis of the steering shaft 24 as shown in FIG. Is installed. The inner end of the electrode 13d is the housing 1
The center of the bottom of 3b is separated by an interval such that the intervening mercury 13a simultaneously contacts the inner end and the bottom. Therefore, when the vehicle is traveling normally, as shown in FIG.
The mercury 13a in the housing 13b is on the side wall of the housing 13b and is not in contact with the electrode 13d (off state).
Further, for example, as shown in FIG. 5, the steering wheel 1 is maintained in the off state even when rotated from the neutral position in FIG. That is, the mercury 13a moves to the center of the bottom of the housing 13b and comes into contact with the electrode 13d only when the acceleration of a predetermined value or more is applied at the time of a vehicle collision, and the electrode 13d and the housing 13b are electrically connected (on state). It is like this.

Switch 12a of the gas dump DOO sensor 12 includes a movable contact 12a ₁ consisting of a roll made from the fixed contact 12a ₂ Prefecture, provided such roll spring 12b is against the movement of the fixed contacts 12a ₂ side of the roll There is. The roll spring 12b
Is electrically connected in parallel to the switch 12a of the sensor 12, and a breakage thereof can be detected by supplying a weak current to the roll spring 12b.

The output end of the battery 14 in the drive circuit 32, that is, between a terminal 33a of the CPU33 point between the coupler 18 and the diode 34, and a line l ₁ is connected, the該線l ₁ A transistor switch 34 is provided on the way. The movable contact of the transistor switch 34 is connected to another terminal 33b of the CPU 33, the transistor switch 34 is normally open and the line l ₁ is opened, and the command signal from the CPU 33 sent from the terminal 33b is transmitted. It is designed to close at the time of supply to close the line l ₁ .

The point b between the diode 34 and the mercury sensor 13 and the CPU 3
A series circuit consisting of a resistor 35 and a transistor switch 36 is located in the middle of a line l ₂ connecting the terminal 33c of the mercury switch 13
It is installed in parallel with. The transistor switch 36
The movable contact is CP
There U33 always connected to the terminal 33d is in open line l ₂ of the open state, is adapted to closing a line l ₂ when the supply of the command signal from the CPU33 that via the terminal 33d.

A line l ₃ is connected between the squib 37 side end of the gas dump sensor 12 of the drive circuit 32 and the terminal 33e of the CPU 33. CP
To the terminal 33f of the U33, an indicator 16 composed of a photodiode that lights up to warn an occupant when any abnormality occurs in the drive circuit 32 is connected.

Next, the operation of the vehicle occupant protection device of the present invention having the above configuration will be described.

When the ignition switch 27 is closed with the protective device attached to the steering wheel 1, the CPU 33
Supplies the command signal to the transistor switches 34 and 36 at predetermined time intervals for a predetermined short time. This command signal causes the switches 34 and 36 to close the lines l ₁ and l ₂ , respectively.

When closing the該線l _1, CPU 33 measures the potential of the point a via a line l _1, is in a state where the battery 14 or the capacitor 15 can supply a sufficient drive current (drive signal) to the squib 37 upon the vehicle collision To detect whether or not.

Further, when the line l ₂ is closed, the CPU 33 measures the potential at the squib 37 side end of the gas dump sensor 12 via the line l _3, and an abnormality such as breakage occurs in the gas dump sensor 12 which is the main sensor. It detects whether or not it is not.

As a result of the above two detections, when it is determined that at least one is abnormal, the CPU 33 alerts the occupant with the indicator 16.

Mercury sensor 13 and gas dump sensor at the time of vehicle collision
If 12 receives a strong shock, each switch 13a,
12a are closed together. Then vehicle battery power 26
Alternatively, a drive current is supplied from the battery 14 to the squib 37, the inflator 8 is activated, the airbag 10 is inflated, and the body of the occupant is protected.

As described above, in this embodiment, the electrode 13d is connected to the housing 13b.
A mercury switch located on the central axis of the steering wheel 1 is used as the mercury sensor 13, and the switch 13 is arranged so that the electrode 13d is substantially parallel to the steering shaft 24.
Since the position of the mercury particles 13a with respect to the electrode 13d does not change even when the steering wheel 1 is rotated during normal traveling of the vehicle, the collision detection does not vary. Therefore, since the mercury sensor 13 can be mounted on the steering wheel 1 together with the other components of the protection device, the protection device as a whole can be made compact, and the connection line between the sensor and the device body can be shortened and the two can be connected in advance. Therefore, the cost is low.

In addition, in the above-described embodiment, the occupant protection device including the collision detection sensor using mercury as the weight has been described.
The present invention can be applied to a sensor using a weight other than mercury, for example, a spherical body such as a steel ball, as long as the requirements described in the claims are satisfied.

(Advantages of the Invention) As described above, the present invention relates to a vehicle occupant protection device including a collision detection sensor disposed on a steering wheel of a vehicle, wherein the collision detection sensor is a conductive weight containing a conductive weight. A housing made of a member, and an electrode arranged in the housing via an insulating member,
The electrodes are arranged along the central axis of the housing, and the housing is attached to the steering wheel so that the central axis of the housing is substantially parallel to the axis of the steering shaft. When the weight is applied, the weight is moved so that the housing and the electrode are electrically connected, so that the collision detection sensor can detect the position of the weight with respect to the electrode even when the steering shaft is rotated during normal traveling of the vehicle. Does not change, so
There is no variation in collision detection. Therefore, since the collision detection sensor can be mounted inside the steering wheel, the protection device can be made compact and the cost can be reduced.

[Brief description of drawings]

FIG. 1 is an exploded perspective view showing an overall structure of a vehicle occupant protection device according to an embodiment of the present invention, FIG. 2 is a circuit diagram showing a structure of an electric part of the occupant protection device, and FIG. 3 is a mercury sensor. FIG. 4 is a front sectional view showing the structure, FIG. 4 is a schematic view showing a state in which the mercury sensor is arranged on a steering wheel, and FIG. 5 is a view showing a state in which the steering wheel is rotated from the state shown in FIG. 1 ... Steering wheel, 2 ... Protective device body, 13
...... Mercury sensor, 13a ...... Mercury particles, 13b ...... Housing,
13c ... Insulating member, 13d ... Electrode.

Claims (2)

(57) [Scope of utility model registration request] 1. A vehicle occupant protection device including a collision detection sensor arranged on a steering wheel of a vehicle, comprising:
The collision detection sensor includes a housing made of a conductive member containing a conductive weight, and an electrode arranged in the housing via an insulating member, and the electrode is arranged along a central axis of the housing. The housing is mounted on a steering wheel such that the central axis of the housing is substantially parallel to the axis of the steering shaft, and the weight moves when the vehicle is subjected to an acceleration of a predetermined value or more. An occupant protection device for a vehicle, characterized in that the electrode and the electrode are electrically connected. 2. The vehicle occupant protection system according to claim 1, wherein the weight is made of mercury.