JP2002205534A - Gas sensor driving device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To quickly actuate auto intake control after power input. SOLUTION: This gas sensor driving device for driving a gas sensor provided in a vehicular air-conditioner for air-conditioning a vehicle room using air outside and inside a vehicle comprises a gas sensor having a sensor portion for detecting the degree of dirt of air outside the vehicle and a heater potion for heating the sensor up to a predetermined temperature, and a timer for counting a time alter power input to the heater portion. Rated voltage or higher (10 V) is applied to the heater portion for a period between a time of starting power input to the heater portion and a predetermined time and rated voltage (7 V) is applied to the heater portion after the passage of the predetermined time.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gas sensor driving device for driving a gas sensor used in an inside / outside air control device of a vehicle air conditioner to control a ratio between an inside air mode and an outside air mode in accordance with a degree of contamination of air outside the vehicle compartment. About.

[0002]

2. Description of the Related Art Conventionally, there is known a vehicle air conditioner having an outside air mode in which air from outside the vehicle is taken into the vehicle to perform air conditioning, and an inside air mode in which air conditioning is performed using air in the vehicle. I have. Conventionally, a vehicle air conditioner equipped with an inside / outside air switching control device using a gas sensor for detecting the degree of contamination of outside air is known.

An air conditioner for a vehicle equipped with a gas sensor switches between an inside air mode and an outside air mode by using a ratio of a degree of contamination outside the vehicle compartment detected by the gas sensor to a reference degree of contamination. At this time, in the conventional vehicle air conditioner,
Automatic intake control is performed by automatically setting the inside / outside air switching door to the outside air mode or the inside air mode by the servo motor.

[0004] This gas sensor takes about 5 to 5 seconds to stabilize the detected value after the vehicle is started and the power is turned on.
It took about 10 to 10 minutes, and the automatic intake control was not activated until the sensor detection value became stable after the engine was started.

[0005]

However, in the conventional vehicle air conditioner, the time required for the gas sensor to stabilize after the power is turned on is long, and the automatic intake control is stopped after the engine is started until the sensor is stabilized. Therefore, there is a problem that exhaust gas emitted from a preceding vehicle or the like during that time enters the vehicle interior.

Therefore, the present invention has been proposed in view of the above-described circumstances, and has as its object to provide a gas sensor driving device capable of operating auto-intake control immediately after power-on.

[0007]

In order to solve the above-mentioned problems, the invention according to claim 1 drives a gas sensor provided in a vehicle air-conditioning system that air-conditions a vehicle cabin using outside air and inside air of a vehicle. In the gas sensor driving device, a gas sensor including a sensor unit that detects a degree of contamination of air outside the vehicle, a heater unit that heats the sensor to a predetermined temperature, and a timer that measures time from when power is supplied to the heater unit And control means for applying a heat-up voltage equal to or higher than a predetermined voltage to the heater unit from a time when power supply to the heater unit is started to a predetermined time, and applying a predetermined voltage to the heater unit after a predetermined time has elapsed. .

[0008] In the invention according to claim 2, the control means starts the auto intake control after a lapse of a predetermined time after starting to apply a predetermined voltage to the heater section.

[0009]

According to the first aspect of the present invention, when driving a gas sensor provided in a vehicle air conditioner that air-conditions a vehicle interior using outside air and inside air of a vehicle, power supply to a heater unit is started. Since a control means for applying a heat-up voltage to the heater from the time to a predetermined time and applying a voltage equal to or lower than the heat-up voltage to the heater after a predetermined time is provided, the auto-intake control can be operated immediately after the power is turned on. it can.

According to the second aspect of the present invention, after the application of a voltage equal to or lower than the heat-up voltage to the heater section is started, the auto intake control is started after a predetermined time has elapsed.
The auto intake control can be operated immediately after the power is turned on, and when starting the auto intake control, an overshoot of a sensor signal can be avoided to avoid erroneous recognition of the gas sensor.

[0011]

Embodiments of the present invention will be described below with reference to the drawings.

[Configuration of Vehicle Air Conditioner] FIG. 1 shows the overall configuration of a host vehicle 1 having a vehicle air conditioner 20. As can be seen from FIG. 1, the front end 1a of the host vehicle 1
A gas sensor 2 for detecting the degree of contamination of outside air based on exhaust gas such as 0 is provided, and a vehicle air conditioner 20 for controlling air conditioning in a vehicle cabin using outside air and inside air is provided inside the vehicle. . The gas sensor 2 and the vehicle air conditioner 20 are connected to a control device 30 that performs automatic intake control of the vehicle air conditioner 20 based on the sensor detection value of the gas sensor 2.

The gas sensor 2 is used in response to the exhaust gas of the leading vehicle 10 to suppress the exhaust gas from entering the passenger compartment. The gas sensor 2 mainly includes a sensor unit that detects the degree of contamination of the outside air and sends a sensor signal to the control device 30, and a heater unit that performs heating for operating the sensor unit.

The sensor section is, for example, Sn which is an n-type semiconductor.
The O ₂ to form sintered composed. The heater generates heat when a voltage is applied to activate the oxidation-reduction reaction of the sensor. When the sensor section is heated to a predetermined temperature, the resistance value changes when a dirt component contained in the outside air such as exhaust gas adheres to the surface thereof, and the sensor signal is controlled according to the resistance value. Output to the device 30. In addition,
In this example, the gas sensor 2 including the sensor unit whose resistance value decreases when a dirt component adheres will be described. However, the gas sensor 2 is not limited thereto.

The control device 30 obtains a resistance value at the time of a gas reaction based on a sensor signal from the sensor unit, and calculates a gas concentration based on a ratio of the resistance value of the sensor unit to the resistance value in clean air.
When it is equal to or less than the reference value, it is determined that the outside air is dirty, and the automatic intake control for restricting the intake of outside air in the vehicle compartment is performed.

FIG. 2 shows a configuration example of the vehicle air conditioner 20. The vehicle air conditioner 20 is a so-called front-rear, left-right and left-right independent temperature control type air conditioner, which mainly divides a passenger compartment into four regions and controls the temperature of each compartment. The intake unit 110, the cooler unit 120, and the heater unit 13
0.

In the following description, a front-rear, left-right and left-right independent temperature control type air conditioner is taken as an example, but the invention is not limited to this.

The intake unit 110 is provided with an intake door 113 for opening and closing the outside air intake 111 and the inside air intake 112 at a free opening, and a fan 115 rotated by a motor 114. While the mixture ratio of the inside and outside air introduced into the vehicle interior is determined accordingly, the amount of air introduced into the vehicle interior is determined according to the rotation speed of fan 115. The drive of intake door 113 is controlled by intake door actuator 116, and motor 114 is driven by fan control amplifier 117.
Is driven and controlled.

The cooler unit 120 is provided with an evaporator 121 (evaporator) for cooling the air introduced by the intake unit 110.
1 is connected to a cooling cycle (not shown) composed of a compressor, a condenser (condenser), an expansion valve, a liquid tank, and the like, and supplies a refrigerant compressed by the compressor.

The heater unit 130 is provided with a heater core 131 through which engine cooling water circulates. On both sides of the heater core 131, bypass paths 132, 132 bypassing the heater core 131 are formed. The air flowing down the cooler unit 120 is heated by passing through the heater core 131.

In the heater unit 130, a front air mixing door 133f is provided upstream of the heater core 131.
And a rear air mix door 133r are provided rotatably. The front air mix door 133f is for controlling the temperature of the conditioned air blown to the front seat, while the rear air mix door 133r is for controlling the temperature of the conditioned air blown to the rear seat. Things. That is, regarding the front air mix door 133f, the ratio between the amount of air passing through half of the heater core 131 and the amount of air passing through the bypass passage 132 is determined in accordance with the degree of opening thereof, whereby the front seat air distribution is performed. The temperature of the air flowing down to the passage 135f is adjusted. Similarly, for the rear air mix door 133r, the temperature of the air flowing down to the rear seat air distribution passage 135r is adjusted according to the opening degree of the rear air mix door 133r.

These two front air mix doors 1
The driving of the rear air mixing door 133r and the rear air mixing door 133r are controlled by a front air mixing door actuator 134f and a rear air mixing door actuator 134r, respectively.

The downstream side of the heater core 131 is divided by a partition wall 136 into a front-seat side air distribution passage 135f and a rear-seat side air distribution passage 135r. The front seat differential air outlet 137, the front seat differential door 137D for opening and closing it, the front seat vent air outlet 138
And a front seat vent door 138D for opening and closing it, a front seat foot outlet 139, and a front seat door 13 for opening and closing the same.
9 are provided. These three front doors 1
Since the combination of the open / close positions of 37D, 138D, and 139D is determined in the outlet mode on the front seat side, the drive is collectively controlled by the front mode actuator 140 via the link mechanism.

On the other hand, air flowing through the front air passage 135f and the rear air passage 135r is provided to the rear air passage 135r formed downstream of the heater core 131 to the rear seat. Front and rear air distribution ratio adjusting door 141D for adjusting the air distribution ratio of the rear, and rear for adjusting the air distribution ratio of the conditioned air blown out from the rear seat vent outlet 143 and the rear seat foot outlet 144, respectively. A mode door 145 is provided.

The front and rear air distribution ratio adjusting door 141D is driven and controlled by a front and rear air distribution ratio adjusting door actuator 142, and can rotate between a position where the rear seat air distribution passage 135r is fully opened and a position where it is fully closed. it can. When the front / rear air distribution ratio adjusting door 141D is turned to a position where a part of the rear air distribution passage 135r is shielded, the front air distribution passage 135f is rotated.
Since a part of the communication path 141 opened in the partition wall 136 between the heater core 13 and the rear air distribution path 135r is opened,
A part of the conditioned air passing through the rear seat 1 flows down to the front seat air distribution passage 135f, whereby the amount of air blown to the front seat increases relatively to the rear seat.

The front and rear air distribution ratio adjusting door 141D
Is a preferred form for the independent temperature control type air conditioner of the present invention because it is provided to make the temperature difference between the front seat side and the rear seat side more sharp, but it is not necessarily essential. Absent.

The rear mode door 145 is driven and controlled by a rear mode door actuator 146. The rear mode door actuator 146 controls the rear mode door 145 according to the opening of the rear mode door 145.
The ratio of the conditioned air flowing down to each of the third and rear foot outlets 144 is adjusted.

A front duct 147f and a rear duct 147r shown in FIG. 3 are connected to the front seat air distribution passage 135f and the rear seat air distribution passage 135r, respectively. More specifically, each of the front seat vent outlet 138 and the front seat foot outlet 139 of the front seat side air distribution passage 135f includes:
A front duct 147f is connected to each of the front ducts 147f, and a rear duct 147 is connected to each of the rear vent vent 143 and the rear foot vent 144 of the rear air distribution passage 135r.
r are connected to each other. FIG. 3 illustrates one of them.

For example, inside a front duct 147f connected to the front seat vent outlet 138, a front left / right air distribution ratio adjusting door 148 for adjusting the air distribution ratio between the left and right front (driver's seat and front passenger's seat). The drive is controlled by a front left / right air distribution ratio adjusting door actuator 149. The front left / right air distribution ratio adjusting door 148
Is rotated from the neutral position to, for example, the right seat side, the amount of air flowing down to the left seat side increases and the amount of air flowing down to the right seat side decreases by that much. As a result, the air conditioning capacity of the left and right seats on the front seat side changes.

Similarly to the front duct 147f, a rear left / right air distribution ratio adjusting door 150 for adjusting the air distribution ratio of the right and left rear seats is provided in the rear duct 147r, and a rear left / right air distribution ratio adjusting door actuator is provided. The drive control is performed by 151. And this rear right and left air distribution ratio adjusting door 1
When 50 is rotated from the neutral position to, for example, the right seat side,
As the amount of air flowing to the left seat increases, the amount of air flowing to the right seat decreases correspondingly. As a result, the air conditioning capacity of the left and right seats on the rear seat side changes.

The above intake door actuator 11
6. Fan control amplifier 117, front air mix door actuator 134f, rear air mix door actuator 134r, front mode actuator 140, front / rear air distribution ratio adjustment door actuator 14
2. Command signals to the rear mode door actuator 146, the front left / right air distribution ratio adjusting door actuator 149, and the rear left / right air distribution ratio adjusting door actuator 151 are sent from the control device 30, respectively.

The control device 30 controls each of the actuators described above and heats the gas sensor 2. Then, after the heating process, control device 30 performs an automatic intake operation based on a sensor signal from gas sensor 2.

[Heat Treatment by Controller 30] FIG.
4 shows a flowchart of a processing procedure of a heating process by the control device 30.

The controller 30 starts the heating process starting from step S1 by operating the ignition switch by the driver. In step S1,
The control device 30 determines whether or not a predetermined period T1 has elapsed since the ignition switch was turned on from off. Here, the predetermined period T1 is a heat-up time shown in FIG. 5 for quickly raising the temperature of the sensor unit by applying a voltage equal to or higher than the rated voltage to the heater unit of the gas sensor 2. When determining that the predetermined period T1 has elapsed, the control device 30 proceeds to step S2,
If it is determined that the predetermined period T1 has not elapsed, the process proceeds to step S3.

In step S2, the control device 30
The voltage applied to the heater is set to the rated voltage Vh, and the process proceeds to step S4. On the other hand, in step S3,
The control device 30 adjusts the voltage applied to the heater section to the rated voltage V
A heat-up voltage (Vh + Vα) equal to or higher than the rated voltage obtained by adding Vα to h is applied. Here, the rated voltage Vh is, for example, 7 V, and the heat-up voltage (Vh + Vα) is 1
Set to 0V.

In step S4, the control device 30 determines whether or not a predetermined period T2 has elapsed since the ignition switch was turned on from off. Control device 3
If 0 is determined that the predetermined period T2 has elapsed, the process proceeds to step S5 to control the vehicle air conditioner 20 to perform an auto intake operation.

The above-mentioned predetermined period T2 is a warm-up period shown in FIG. 5 until the sensor reaches a predetermined temperature, the sensor operates stably, and the sensor signal stabilizes. 20 does not perform any processing for suppressing exhaust gas. Further, the control device 30 enters a semi-inside air mode in which the outside air and the inside air are taken into the vehicle air conditioner 20 at the same ratio or a predetermined ratio (for example, outside air: inside air = 6: 4) within the predetermined period T2. Further, the control device 30
The voltage applied to the heater is changed to a heat-up voltage (Vh + V
When the sensor voltage is switched from α) to the rated voltage Vh, the overshoot in FIG. 5 in which the sensor signal temporarily increases sharply is avoided, and the automatic intake control is started. By providing the predetermined period T2, the control device 30 can avoid erroneous recognition of the gas sensor when starting the automatic intake control.

In the control device 30 according to the present embodiment, when controlling the auto intake operation, the following control may be performed.

When the vehicle is running, the control device 30 controls the intake door 11 based on the degree of contamination of the outside air.
The intake door actuator 116 may be controlled so as to change the driving speed of the third actuator. That is, when driving the intake door actuator 116, the control device 30 changes the coefficient for adjusting the driving speed of the intake door actuator 116 according to the magnitude of the sensor signal from the gas sensor 2. The control device 30 drives the intake door 113 slowly when the outside air is clean, and controls the intake door 11 when the outside air is dirty.
By controlling intake door actuator 116 so that drive 3 is driven fast, it is possible to suppress a large amount of dirty outside air from entering the vehicle interior.

Control device 30 may control the automatic intake operation by changing the coefficient for calculating the sensor signal according to the vehicle speed. That is, the control device 30
When determining the degree of contamination of the outside air based on the resistance value of the gas sensor, the coefficient is changed. This makes it easy to detect that the degree of dirt is large even when the vehicle speed is low, for example. Specifically, when the current gas sensor resistance value GRs is equal to or lower than a predetermined value (Ω), the control device 30 normally air-conditions only with outside air when the vehicle speed becomes equal to or higher than a predetermined vehicle speed (for example, 60 km / h). Below a predetermined vehicle speed (for example, 50
km / h) or less, the intake door actuator 116 is used to perform air conditioning using a predetermined ratio of inside air.
To control. Then, when the current gas sensor resistance value GRs is equal to or higher than the predetermined value (Ω), the control device 30 performs air conditioning only with the outside air when the current vehicle sensor speed is equal to or higher than the predetermined vehicle speed (for example, 60 km / h), For example, 50km /
h) The intake door actuator 11 is used to perform air conditioning by using the inside air more than the above predetermined ratio when the following conditions are satisfied.
6 is controlled.

Further, the control device 30 may determine whether or not to perform the auto intake control having the semi-inside air mode based on the outside air temperature and the vehicle speed in order to prevent the knees of the vehicle user from getting cold. As a result, the control device 30 performs the half inside air mode when the outside air temperature is high or when the outside air temperature is low and the vehicle speed is low, and can eliminate the half inside air mode under other conditions.

Further, the control device 30 controls the intake door actuator 116 so as to automatically take in outside air at predetermined intervals, for example, when the compressor is off, in order to prevent clouding of the vehicle window. It may be controlled.

Further, the control device 30 may change the ratio of using outside air based on the target blowing temperature and determine whether or not to perform the automatic intake control according to the ratio of using outside air. .

The above embodiment is an example of the present invention. For this reason, the present invention is not limited to the above-described embodiment, and other than the present embodiment, various modifications may be made according to the design and the like within a range not departing from the technical idea according to the present invention. Can be changed.

[Brief description of the drawings]

FIG. 1 is a diagram showing an entire configuration including a vehicle air conditioner to which the present invention is applied.

FIG. 2 is a configuration diagram of a vehicle air conditioner to which the present invention is applied.

FIG. 3 is a main part configuration diagram of a vehicle air conditioner to which the present invention is applied.

FIG. 4 shows a flowchart of a processing procedure of a heating process by a control device.

FIG. 5 is a diagram showing a relationship between a voltage applied to a heater unit, a sensor signal output from the sensor unit, and time when starting to use the gas sensor.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Own vehicle 2 Gas sensor 20 Vehicle air conditioner 30 Control device 111 Outside air intake 112 Inside air intake 113 Intake door 116 Intake door actuator

Claims (2)

[Claims] 1. A gas sensor driving device for driving a gas sensor provided in a vehicle air conditioner that air-conditions a vehicle cabin using outside air and inside air of a vehicle, a sensor unit for detecting a degree of contamination of air outside the vehicle, and the sensor A gas sensor having a heater unit for heating the heater unit to a predetermined temperature; a timer for measuring a time from power-on to the heater unit; and Control means for applying a heat-up voltage equal to or higher than a predetermined voltage and applying a predetermined voltage to the heater after a predetermined time has elapsed. 2. The gas sensor driving device according to claim 1, wherein the control means starts the automatic intake control after a predetermined time has elapsed after the application of the predetermined voltage to the heater section.