JP3196295B2 - Automotive air purifier - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an air purifier equipped with a gas sensor and mounted on an automobile tower.

[0002]

2. Description of the Related Art In a conventional air purifier equipped with a gas sensor, the number of revolutions of a motor is controlled without taking into account changes in the output of the gas sensor due to changes in the humidity of the atmosphere in which the gas sensor is placed. Was.

[0003]

In such a configuration of a conventional on-vehicle air purifier, for example, when the rain suddenly falls or the air conditioner is turned on, the humidity in the vehicle interior changes, which causes an apparent change. The gas sensor erroneously detects that the gas has become dirty, and there is a problem in that the fan motor is rotated even though the air in the vehicle interior is not dirty, and an erroneous operation does not match the actual feeling.

An object of the present invention is to solve the above-mentioned problems, and an object of the present invention is to provide an on-vehicle air purifier capable of performing stable operation regardless of the influence of humidity around a gas sensor.

[0005]

In order to achieve the above object, a vehicle air purifier according to the present invention has a motor drive unit for controlling the rotation of a motor via a control circuit, and a gas sensor for detecting dirt in a vehicle interior. And a humidity sensor installed near the gas sensor, and the initial value of the gas sensor and the humidity sensor.
Storage means for storing an initial value;
Set motor rotation based on initial value and initial value of humidity sensor
Establish a reference value to determine the current humidity sensor value.
The reference value is changed accordingly.

[0006]

DETAILED DESCRIPTION OF THE INVENTION The present invention in a configuration as described above, since if they lowered resistance value of the sensor portion of the gas sensor by humidity change is input from the humidity sensor to the correction means, the voltage by the resistance value change of the sensor unit Is reduced to a constant value, it is possible to eliminate a malfunction due to a change in humidity.

Further, it becomes possible to eliminate the malfunction does not reach a level to rotate the motor even when the humidity changes in the gas Susensa.

[0008]

(Embodiment 1) Hereinafter, a first embodiment of the present invention will be described with reference to FIGS. In the figure, 1 is a battery,
The motor 2 is connected to a motor drive unit 3 that controls the rotation of the motor 2. 4 is a gas sensor 5 and a humidity sensor 6
And a power supply unit connected to supply power to the correction unit 7 and the control circuit 8.

In the above configuration, the operation of the gas sensor 5 will be described. When the sensor section 10 is heated by the heater 9 and the sensor section 10 detects gas, the sensor section 1
The resistance value of 0 becomes smaller. Here, assuming that the resistance value of the sensor unit 10 is Ri and the fixed resistance 11 is Rc, the voltage at the point A is R
Since it can be expressed by c * Vce / (Ri + Rc), the change in Ri is converted into a voltage change and output to the next stage. However, if there is a change in humidity near the gas sensor 5, the gas sensor 5
Since the resistance value of the sensor unit 10 is reduced due to the above characteristic, the gas is output to the next stage in the same manner as when gas is detected. Also,
The humidity sensor 6 does not output when there is no change in the absolute humidity,
When the resistance value of the sensor unit 10 of the gas sensor 5 decreases due to a change in humidity, an input from the humidity sensor 6 is input to the correction unit 7. A due to the change in the resistance value of the sensor unit 10
By lowering the voltage at the point to a constant value, it is possible to eliminate malfunctions due to the influence of humidity changes.

(Embodiment 2) Hereinafter, a second embodiment of the present invention will be described with reference to FIGS. As shown in the figure, a first initial value storage device 12 is provided for the output of the gas sensor 5 and a second initial value storage device 13 is provided for the output of the humidity sensor 6, and the respective initial values are stored. The resistance value of 10 is defined as Rio, and the level for rotating the motor 2 at low speed is defined as Ri1 / Ri.
0, the level for high-speed rotation is set to Ri2 / Ri0, and the resistance value of the sensor unit 10 when the gas sensor 5 changes in humidity is Ri3, the low-speed rotation level of the motor 2 is Ri4 / Ri3, and the high-speed level As Ri5 / Ri3, Ri4 / Ri3> Ri1 / Ri0, Ri5 / Ri
When 3> Ri2 / Ri0 is set, the state shown in FIG.
Even if there is a change in humidity in the gas sensor 5, it does not reach the level at which the motor 2 is rotated, and malfunction can be eliminated. Here, it is possible to easily change the setting of the level by making the level setting correspond to the reference value 1: 1 with the microprocessor.

[0011]

As is clear from the above embodiment, according to the present invention, the humidity sensor is provided near the gas sensor and the output of the gas sensor is corrected by the correction means. It is possible to provide an on-vehicle air purifier capable of operating an appropriate air purifier irrespective of the influence of humidity and performing stable operation.

[Brief description of the drawings]

FIG. 1 is a circuit block diagram of a vehicle air purifier according to a first embodiment of the present invention.

FIG. 2 is a circuit diagram of the gas sensor according to the first embodiment.

FIG. 3 is a circuit block diagram of a vehicle air purifier according to the second embodiment.

FIG. 4 is a characteristic diagram showing an output operation of the gas sensor.

[Explanation of symbols]

 2 Motor 3 Motor drive unit 5 Gas sensor 6 Humidity sensor 7 Correction unit 8 Control circuit 12, 13 Storage means

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) B01D 46/46 B01D 53/30 B60H 3/06

Claims (1)

(57) [Claims] 1. A motor drive unit for controlling rotation of a motor via a control circuit, a gas sensor for detecting dirt in a vehicle interior, a humidity sensor installed near the gas sensor,
Record the initial value of the gas sensor and the initial value of the humidity sensor.
Storage means, the initial value of the gas sensor and the humidity sensor.
Set a reference value to set the rotation of the motor based on the initial value
Together with the reference value according to the current value of the humidity sensor.
Changing vehicle air purifier.