JPS5979840A - Smoke detecting apparatus for vehicle - Google Patents

Abstract

PURPOSE:To prevent erroneous operation under a usual state to be used, by a method wherein an electric signal is generated in correspondence with the amount of impurities contained in atmospheric air and an output signal is gennerated when the amount of impurities exceed a set value. CONSTITUTION:A signal generating apparatus 1 is constituted in such a structure that a light emitting element 3 and a light receiving element 4 are arranged in a case 2 in opposed relation to each other through a small window and the light path between both of them is usually a straight advance path but straight advance light is reduced when the light path is blocked by smoke particles 5 while the electric signal generated by the light receiving element 4 is also reduced. This signal generating apparatus 1 is arranged to a proper position of a vehicle ceiling. The electric signal of the signal generating apparatus 1 is transmitted to a comparison apparatus 6 and compared with a preset value therein to output an electric output signal S0 showing whether said electric signal exceeds the set value or not. By this method, erroneous operation under a usual state to be used can be prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a device that detects harmful smoke components such as cigarettes in a vehicle interior, and adjusts the operating state of an air conditioning unit, ventilation system, or air purifier based on the detection signal. It can be used in combination with a control device.

The problem with detecting smoke in a vehicle interior is that the state of air flow within the vehicle interior is not constant and changes depending on the usage status of the air conditioning unit and window glass, and individual differences in the smoking methods of the occupants.

Experiments have revealed that simply placing the smoke detection element at an appropriate position on the vehicle ceiling has problems such as variations in detection due to airflow and slow response speed of the detection element.

In view of the above-mentioned problems, the present invention provides a smoke detection device for a vehicle that can obtain sufficient detection sensitivity especially when detection sensitivity is required, and does not cause false detection when the person is not in a smoking state. The purpose is to

For this reason, the present invention employs a signal generating device that generates an electric signal corresponding to the amount of impurity components contained in the ambient air,
The present invention is characterized in that, in response to this electrical signal, a set value of a comparator that generates an output signal when the amount of the impure component exceeds a preset value is changed in accordance with the usage state of the smoking device.

According to the present invention, the signal generating device 1 can be of a photo-electric conversion type as shown in FIG. 1 or FIG. 2. In the example shown in FIG. 1, the signal generating device 1 has a light emitting element 3 and a light receiving element 4 disposed facing each other in a case 2 through a small window, and although the optical path between them is normally a straight path, smoke particles When the light receiving element 5 blocks the optical path, the amount of straight light is reduced, and the electrical signal generated by the light receiving element 4 is also reduced. In addition, in the example of FIG. 2, the light emitting element 3 and the light receiving element 4 do not have a straight optical path, but the particles 5
When particles fly to a certain position, a reflection path is created by the particles, and the electric signal generated by the light receiving element 4 increases. In addition, it is also possible to use a material that generates an electric signal depending on the amount of oxidizing impurity gas components attached by utilizing an oxidation reaction such as tin oxide.

These signal generators 1 are arranged at an appropriate position on the ceiling of the vehicle or at an air introduction part within the case of an air purifier (not shown).

The electrical signal from the signal generator 1 is sent to the comparator 6 shown in FIG. 1 or 2, where it is compared with a preset value and an electrical output signal S o l/ indicating whether or not it exceeds the set value.
, l<is output. This electrical output signal SO is input to an electrical control device (not shown), thereby controlling the operation of the main or auxiliary air conditioning unit, ventilation device, or air purifier. Further, instead of such operation control, it is also possible to simply turn on an indicator light.

FIG. 3 shows the circuit configuration of the comparison device 6.

In FIG. 3, a light emitting diode is used as the light emitting element 3, which is connected in series with a resistor 3, and a constant voltage CC is applied to it, so that it emits light with a constant amount of light.

The degree of conductivity of the light receiving element 4 increases as the amount of light received increases,
The voltage value of the signal voltage Vs generated at the emitter resistance increases. The signal voltage Vs is determined by the comparator 9 to the comparison set value V
c and a level signal corresponding to the magnitude relationship is generated from the output terminal of the comparator 9 as an electrical output signal SO.

The comparison set value Vc of the comparator 9 is normally set by a resistor 10.
The value is determined by 11.12. The resistor 12 is for setting hysteresis. Therefore, a resistor 13 for changing settings and switches 14 and 15 are connected in parallel with the resistor 11. Switches 14 and 15 are responsive to smoking implements, and in this example, a switch 14 that is closed by pulling out the ashtray and a switch 15 that is closed by igniting a cigarette lighter are used together. When either of these switches closes, the value of Vc decreases. In other words, the comparator 9 responds to a smaller value of Vs.

According to this detection device, the comparison set value Vc of the comparator 9 becomes a small value when the smoking device is in use, so that the device operates sensitively to the presence of even a small amount of smoke. Conversely, when the smoking implement is not in use, the comparison set value VC is large, so that the device will not malfunction due to slight smoke or electrical noise that is not a problem.

Note that the present invention is not limited to the configuration of the above-described embodiments, and can be implemented with appropriate modifications. For example, switch 14.15 may be a relay contact actuated by a sensing switch responsive to an ashtray or cigarette lighter. Further, only the switch 14 that responds to the ashtray may be used, or if only the switch 15 that responds to the cigarette lighter is used, an appropriate delay device may be attached. In the case of using the Moron switch 14, a delay device can be provided, in which case the delay device comprises a holding relay connected in parallel with the switch 14 or 15, which holding relay is connected in parallel with the switch 14.1.
The configuration is such that the current path passing through the setting change resistor 13 is maintained for a certain period of time even after the resistor 5 is opened.

Furthermore, instead of changing the comparison setting value Vc of the comparator 9, it is also possible to change the value of the signal voltage Vs on the input side. In this case, an appropriate voltage dividing resistor is added to the circuit for the signal voltage
As the selection switch, a switch that responds to the state of use of the smoking implement may be employed.

Furthermore, as shown in FIG. 4, an amplifier circuit consisting of a transistor 16, a resistor 17, and a diode 18 is attached to the signal voltage circuit, and the amplification degree of this amplifier circuit is set to 1 or less. Switch 14.1
When the switch 5 is open, the signal voltage Vs is set to a smaller value, and when the switch is in a smoking state, the signal voltage is set to a larger value. Note that, when using the amplifier circuit, it is of course possible to select one or more amplification degrees using a switch. It is also possible to use such a change in the amplification degree together with the change in the setting value described above.

Furthermore, in the case of the photo-electric conversion type signal generating device 1, a light shielding body that moves mechanically in conjunction with the usage state of the smoking implement may be provided in the optical path. In this case, for example, in the case of the reflective type shown in FIG. 2, the light path width may be increased by removing the light shield when the smoking device is in use. In this case, the electrically set value of the comparator 6 does not change, but the signal voltage Vs
What is meant by this is that the amount of the above impurity component is changed, and thereby the comparator essentially changes the detection set point for the impurity component.

As described above, according to the present invention, the smoke detection sensitivity can be sufficiently increased only when necessary in response to smoking, and malfunctions can be prevented during normal use.

[Brief explanation of the drawing]

1 and 2 are block diagrams showing the cross-sectional structure of the signal generating device and the electrical connections of the comparison device, respectively, and FIGS. 3 and 4 are electrical connection diagrams showing the circuit structure, respectively. 1...Signal generator, 6...Comparison device, 9...Comparator, 14.15...Switch responsive to smoking implement. Representative Patent Attorney Takashi Okabe Figure 1 Figure 2 Figure 4

Claims (1)

[Claims] A signal generating device is placed in the vehicle interior and generates an electrical signal corresponding to the amount of impurity components contained in the ambient air, and a signal generating device that outputs an electric signal in response to the electrical signal when the amount of the impurity component exceeds a preset value. a comparator for generating a signal, the comparator being adapted to substantially change the set point in response to usage of the smoking device.