JPH0665532B2 - Occupant detection device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Object of the Invention (Field of Industrial Application) The present invention relates to an occupant detection device on a moving body.

INDUSTRIAL APPLICABILITY The occupant detection device of the present invention is used for controlling the blowing of an air conditioner for a vehicle, controlling a car audio system, and preventing forgetting to close the side window, sunroof, and the like.

(Prior Art) As a conventional occupant detection device, as shown in FIG. 9, a contact movable portion 31 that moves when a human body sits down, and a contact fixing portion 32 that comes into contact with the contact movable portion 31 by this movement. It is known that a seating sensor is provided in a vehicle seat to control the position of a speaker (Japanese Patent Laid-Open No. 60-1).
10546 publication).

(Problems to be Solved by the Invention) Since the conventional seating sensor described above is mechanically turned on / off by the load of an object, it does not detect objects other than the human body or detect a light person (eg, baby). There are drawbacks such as.

Further, as a non-contact type means for detecting the presence / absence and position of an occupant, a method using a television camera or the like can be considered. However, with this means, (1) the detection unit and the detection circuit are complicated and the sensor is expensive, (2) the detection area cannot be easily set due to the size and arrangement of the electrodes, and (3) the appearance inside. There are drawbacks such as difficulty in mounting the sensor without changing the design.

The present invention overcomes these drawbacks, and an object of the present invention is to provide an occupant detection device capable of reliably detecting a human body with little deterioration in detectability.

[Structure of the Invention] (Means for Solving Problems) An occupant detection device according to the present invention includes a sheet-shaped conductive layer provided on a resin vehicle seat having a resin seat frame that supports a seat cushion, An on-vehicle conductor facing the conductive surface of the conductive layer with at least a portion of an occupant seated on the on-vehicle seat interposed therebetween, and a change in capacitance between the on-vehicle conductor and the conductive layer, It is characterized in that it has a detecting means for detecting, and a detection processing means for generating an electric signal indicating the presence of an occupant when the detecting means detects an increase in capacitance.

The greatest feature of the occupant detection device of the present invention is (1) the use of a resin-made vehicle seat having a resin seat frame,
(2) The vehicle seat is equipped with a sheet-shaped conductive layer.

In an on-vehicle seat equipped with a conductive layer, a seat frame that supports a seat cushion is made of resin. For example, as the resin seat frame, a flat surface portion is formed on the support surface of the seat cushion so as to extend toward the front of the substantially central portion of the seat frame, and the front surface of the seat cushion is elastic by the flat surface portion. Can be supported by.

The conductive layer need only be in the form of a sheet and have a wide surface, and is mounted on the flat portion of the seat frame. The width of this surface is preferably as wide as possible. Further, it is preferable that the conductive layer is arranged below the hip of the seated occupant. Usually, this conductive layer is formed by attaching a conductive sheet,
A method for forming a thin film by sputtering or vapor deposition may be used. Usually, aluminum, chromium, nickel or the like is used as a material for forming the conductive layer.

An automobile body is usually used as the on-vehicle conductor.

As the detecting means, a known means for detecting a change in capacitance between the on-vehicle conductor and the conductive layer can be used.
The detection processing means generates an electric signal indicating the presence of an occupant when the detection means causes an increase in electrostatic capacity, and known means can be used. As these means, for example, a detection circuit or the like that detects a change in output voltage or frequency output can be used.

(Function) The human body can be regarded as a substance that is electrically equivalent to water and has a high dielectric constant (about 80). On the other hand, other solid materials generally have a low induction rate except for conductive materials.

Therefore, in the occupant detection device of the present invention, as shown in FIG. 8, a sheet-shaped conductive layer 25 provided on a resin vehicle seat and an on-board conductor 29 facing the conductive surface of the conductive layer 25. When the human body 30 is placed between the and, a change in the dielectric constant occurs, and the change can be detected.

Therefore, if this device is used, the presence or absence of a human body on the vehicle seat can be detected safely and reliably.

(Examples) Hereinafter, the present invention will be described with reference to Examples.

(Embodiment 1) An overall perspective view of a vehicle seat used in an occupant detection system of this embodiment is shown in FIG. 3, and a perspective view and a longitudinal sectional view of a resin seat frame having a conductive layer are respectively shown in FIG. It is shown in FIG.

The resin car seat is a car seat having a seat cushion 1 and a seat back 3. The lower surface of the seat cushion 1 is supported by the seat cushion frame 2, the seat back 3 is supported by the seat back frame 4, and the seat cushion frame 2 is supported between the seat cushion frame 2 and the floor (not shown). The seat adjusters 5 and 6 as means are provided,
A cover 7 is attached to cover the seat adjusters 5 and 6.

The seat cushion frame 2 is formed of resin or the like by resin molding. Then, as shown in FIGS. 1 and 2,
The seat cushion frame 2 has a rectangular shape as a whole. Both sides 13a, 1 of the seat cushion frame 2
Side walls 9 are provided upright on 3b and front and rear edges 13c and 13, respectively, and support portions 8 and 10 are provided on the front edge 13c. The lower surface of the seat cushion 1 is supported by the support portions 8 and 10, and the side walls 9 provide the seat cushion 1
The sides of are retained. Also seat cushion frame 2
A flange is provided on the periphery of the seat cushion frame 2, and the peripheral edge 20 of the surface layer material 19 of the seat cushion 1 placed on the seat cushion frame 2 is locked by a clip as shown in FIG.

The front ends of the support portions 8 and 10 of the seat cushion frame 2 are located substantially in the center of the seat cushion frame 2 in the front-rear direction, and the front edge 1 of the seat cushion frame 2 is located from this front end.
A pair of left and right flat surface portions 11 are formed to extend toward 3c. Therefore, the flat surface portion 11 is located at a portion that supports the left and right knees of the seat occupant via the seat cushion 1. Moreover, since the flat surface portion 11 has a flat plate shape and is made of resin, it can be moved up and down around the front ends of the support portions 8 and 10.

The rear end of the support portion 8 of the seat cushion frame 2 is located substantially in the center of the seat cushion frame 2 in the front-rear direction, and another flat surface portion 12 is formed from this rear end toward the rear edge 13 of the seat cushion frame 2. ing. Therefore, the flat portion 12 is located at a portion that supports the buttocks of the seat wearer through the seat cushion 1. Moreover, since the flat surface portion 11 has a flat plate shape and is made of resin, it can be moved up and down around the rear end of the support portion 8. Flat part 11
Two notches 12a are formed at the rear end.

The rear edge 13 of the seat cushion frame 2 is formed with a pair of first locking grooves 15a facing rearward and a pair of second locking grooves 15b facing upward on both sides at a central portion thereof. A root portion of the torsion spring 17 is locked in each locking groove 15a, 15b. The ends of the torsion spring 17 are locked and fixed on both sides of the seat cushion frame 2. The tip 17a of the torsion spring 17 elastically supports the rear end of the flat portion 12 upward. That is, the flat portion 12 elastically supports the buttocks supporting portion of the seat occupant of the seat cushion 1. As shown in FIG. 2, there is a ridge 12b extending in the left-right direction of the seat on the lower surface of the rear end of the flat portion 12 to prevent forward movement of the front end 17a of the torsion spring 17. It has been stopped.

Mounting grooves 21 and 22 are formed on the support surface 8 and the rear edge 13 of the seat cushion frame 2 along the left-right direction of the seat. Coupling members 23 and 24 that support the seat cushion frame 2 are fitted in the mounting grooves 21 and 22, respectively. The connecting members 23 and 24 support the seat cushion frame 2 on the floor via the seat adjusters 5 and 6. Moreover, the connecting member 24 is located below the root portion of the torsion spring 17, and the torsion spring 17 is provided via the rear edge 13 of the seat cushion frame 2.
Support.

Further, in this occupant detection device, as shown in FIG. 1, about 150 is provided on the flat portion 12 of the seat frame 2.
mm × 200mm conductive layer (materials Al, Cr, Ni, etc.) 25
a is equipped with one electrode. In addition, the automobile body (8th embodiment) facing the conductive surface of the conductive layer 25a.
A condenser is constructed in the vehicle compartment by using 29) in the figure as the other electrode.

The detection means for detecting the change in electrostatic capacitance is the sixth
The detection circuit for detecting the fluctuation of the output voltage (B) shown in the figure or the detection circuit for detecting the fluctuation of the frequency output shown in FIG. 7 may be used. Further, A in these figures is a detection unit (capacitor composed of both electrodes) E is a reference capacitor, C in FIG. 7 is an oscillation circuit, and D is an output frequency processing means.

According to the present embodiment, when a human body enters the condenser, the capacitance of the condenser changes, so that the occupant can be detected in a non-contact manner.

Example 2 A perspective view of a resin seat frame used in this example is shown in FIG. This seat frame mainly has (1) a reclining mechanism 26, and (2) two grooves 27 in the flat surface portion of the top plate supporting portion.
Substantially the same as that used in Example 1 except that the conductive layer 25b is provided between the two, and (3) the flat portion has a predetermined cutout 28 so as to be an elastic member. is there.

Even in an occupant detection device using this seat frame,
It has the same effect as the first embodiment.

(Embodiment 3) The resin seat frame used in this embodiment is the same as that used in Embodiment 2, and the sheet-like conductive layer 25c has a predetermined flat portion of the seat frame as shown in FIG. It is equipped on almost the entire surface and has a large area.
Therefore, in the occupant detection device using this seat frame, the presence / absence of an occupant can be detected more safely and reliably than in the case of the second embodiment.

[Advantages of the Invention] The occupant detection device of the present invention includes at least a sheet-shaped conductive layer mounted on a resin vehicle seat having a resin seat frame that supports a seat cushion, and at least an occupant seated on the vehicle seat. An on-vehicle conductor facing a conductive surface of the conductive layer with a part interposed therebetween, a detection means for detecting a change in capacitance between the on-vehicle conductor and the conductive layer, and a predetermined detection process. And means.

On the other hand, it can be said that the human body is electrically equivalent to water and has a high dielectric constant. Therefore, when this human body is placed between the two electrodes, the capacitance of the capacitor is converted, so that the presence or absence of an occupant can be detected.

Therefore, the conventional occupant detection device has a short contact life because it uses the mechanical contact, while the occupant detection device of the present invention detects the human body in a non-contact manner, so that the detectability does not deteriorate.

In addition, this occupant detection device is (1) that the detection unit and detection circuit can be provided by a simple and inexpensive sensor compared to the non-contact method using a television camera, etc. (2) The detection area is the size of the electrode,
It can be easily set by placement, and (3) the sensor can be installed without changing the design of the internal appearance,
(4) Capacitance type consumes less current,
(5) Since it is mounted on the resin seat frame, there is an effect that the conductive layer can be arranged in the seat cushion without special insulating means and the seat structure is simplified.

[Brief description of drawings]

FIG. 1 is a perspective view of a resin seat frame having a conductive layer, which is used in the occupant detection apparatus according to the first embodiment. FIG. 2 shows the seat I having the seat frame shown in FIG.
It is a longitudinal cross-sectional view taken along the line I. FIG. 3 is an overall perspective view of the seat used in the first embodiment. FIG. 4 is a perspective view of a resin-made seat frame used in the second embodiment and having a conductive layer. FIG. 5 is a perspective view of a resin seat frame having a conductive layer used in the third embodiment. FIG. 6 is an explanatory diagram of a detection circuit which is used in an occupant detection device and determines whether or not a human body is seated by a change in output voltage. FIG. 7 is an explanatory diagram of a detection circuit that determines the sitting of a human body based on a change in frequency. 8th
The figure is an explanatory view showing the action of detecting an occupant when a human body is placed between both electrodes. FIG. 9 is an explanatory sectional view of an occupant detection sensor used in a conventional occupant detection device. DESCRIPTION OF SYMBOLS 1 ... Seat cushion, 2 ... Seat cushion frame, 3 ... Seat back, 4 ... See-back frame, 5, 6 ... Seat adjuster, 7 ... Cover, 8, 10 ... Support part, 9 ... Side wall, 11, 12 ... Plane part , 13 ... Rear edge, 15 ... Locking groove, 17 ... Torsion spring, 19 ... Surface material, 20 ... Peripheral material, 21, 22 ... Mounting groove, 23, 24 ... Connecting member, 25a, 25b, 25c ... Conductive layer, 26 ... Reclining mechanism, 27 ... Hole, 28 ... Notch, 29 ... On-vehicle conductor, 30 ... Human body, 31 ... Contact moving part, 32 ... Contact fixing part, A ... Detecting part (capacitor), B ... Output voltage, C ... Oscillation circuit, D ... Output frequency processing means, E ... Reference capacitor

Claims (2)

[Claims] 1. A sheet-like conductive layer provided on a resin vehicle seat having a resin seat frame for supporting a seat cushion and at least a part of an occupant seated on the vehicle seat, the conductive layer being provided between the sheet-like conductive layer and the conductive layer. An on-vehicle conductor facing the conductive surface of the layer, a detection unit that detects a change in capacitance between the on-vehicle conductor and the conductive layer, and a detection unit that detects an increase in capacitance. An occupant detection device comprising: a detection processing unit that generates an electric signal indicating the presence of an occupant. 2. The occupant detection device according to claim 1, wherein the on-vehicle conductor is a vehicle body.