Air-conditioning control for a motor vehicle

• US 4,478,049 A
• Filed: 09/13/1982
• Issued: 10/23/1984
• Est. Priority Date: 09/15/1981
• Status: Expired due to Term

• Current Assignee: Nippondenso Co., Ltd. (DENSO Corporation)
• Original Assignee: Nippondenso Co., Ltd. (DENSO Corporation)
• Inventors: Eguchi, Osamu, Fukui, Tomonori
• Primary Examiner(s): TANNER, HARRY B
• Application Number:
  US06/417,611
• Time in Patent Office: 771 Days
• Field of Search: 62/78, 62/186, 62/158, 62/244, 62/179, 236/49, 236/46 F, 98/2.01, 98/2.06, 98/2.11, 165/12, 165/16, 165/43, 165/42, 364/418
• US Class Current: 62/179
• CPC Class Codes: B60H 1/0073 Control systems or circuits characterised by particular algorithms or computational models, e.g. fuzzy logic or dynamic models
• CPC Class Codes: B60H 1/008 the input being air quality
• CPC Class Codes: B60H 3/0085 Smell or pollution preventing arrangements B60H3/0007, B60H3/0071, B60H3/02, B60H3/06 take precedence

Abstract

A gas sensor is provided to detect the concentration of a gas component included in external air which may be led into the compartment of a motor vehicle. When the level of an output signal from the sensor exceeds a first predetermined value, the air-conditioning system is switched to internal air recirculation mode so that unclean external air is not led into the vehicle compartment. When the level of the gas sensor output is continuously kept below a second predetermined value, which is smaller than the first predetermined value, for a predetermined period of time, the system is switched to external air introduction mode. Instead of directly comparing the level of the gas sensor output with the first and second predetermined levels, a relative value of the gas sensor output may be compared therewith. In one embodiment, it is detected whether the motor vehicle travels in a city area or suburb from the varying state of the gas sensor output or its relative value so that the first predetermined value may be set to either higher or lower value.

Claims

1. An air conditioning system for use with a motor vehicle, comprising:

(a) an air-conditioning unit arranged to control the temperature of air in the compartment of said motor vehicle by either introducing external air or recirculating internal air in said compartment;

(b) switching means for switching the airflow led to said air-conditioning unit so that one of said external and internal air is led to said air-conditioning unit in accordance with a control signal;

(c) means for producing an output signal indicative of the concentration of a gas component included in said external air which may be led into said vehicle compartment; and

(d) controlling means responsive to said output signal for producing said control signal so that said switching means is controlled such that said internal air is led to said air-conditioning unit when said level of said output signal is equal to or greater than a predetermined value, said controlling means being arranged to change said predetermined value in accordance with the number of times of detecting that said level is greater than or equal to said predetermined value and the number of times of detecting that a predetermined period of time has lapsed after said level becomes below said predetermined value.

3. An air-conditioning system as claimed in claim 1, wherein said controlling means is further for determining whether said motor vehicle travels in a city area or a suburb by detecting the state of variation in the level of said output signal, and for changing said predetermined value such that a higher value is set when it is detected that said motor vehicle travels in a city area, and a lower value is set when it is detected that said motor vehicle travels in a suburb.

5. An air-conditioning system as claimed in claim 3 or 4, wherein said controlling means is arranged to detect the place where said motor vehicle travels by detecting the state of variation and the level of said output signal, further changing a variable in one direction by a predetermined amount each time said level is detected to be greater than or equal to said first predetermined value and in opposite direction by said predetermined amount each time it has been detected that said level is kept below said first predetermined value for a predetermined period of time, and by detecting the value of said variable.

2. An air-conditioning system for use with a motor vehicle, comprising:

(a) an air-conditioning unit arranged to control the temperature of air in the compartment of said motor vehicle by either introducing external air or recirculating internal air in said compartment;

(b) switching means for switching the airflow led to said air-conditioning unit so that one of said external and internal air is led to said air-conditioning unit in accordance with a control signal;

(c) means for producing an output signal indicative of the concentration of a gas component included in said external air which may be led into said vehicle compartment; and

(d) controlling means responsive to said output signal for producing said control signal so that said switching means is controlled, said switching means being controlled such that said internal air is recirculated to be led to said air-conditioning unit when said level of said output signal exceeds a first predetermined value, and said external air is led to said air-conditioning unit when said level of said output signal is continuously kept below a second predetermined value, which is smaller than said first predetermined value, for a predetermined period of time, said controlling means being arranged to change said first predetermined value in accordance with the number of times detecting that said level is greater than or equal to said first predetermined value and the number of times of detecting that a predetermined period of time has lapsed after said level becomes below said first predetermined value.

4. An air-conditioning system as claimed in claim 2, wherein said controlling means is further for determining whether said motor vehicle travels in a city area or a suburb by detecting the state of variation in the level of said output signal, and for changing said first predetermined value such that a higher value is set when it is detected that said motor vehicle travels in a city area, and a lower value is set when it is detected that said motor vehicle travels in a suburb.

6. An air-conditioning system for use with a motor vehicle, comprising:

(a) an air-conditioning unit arranged to control the temperature of air in the compartment of said motor vehicle by either introducing external air or recirculating internal air in said compartment;

(b) switching means for switching the airflow led to said air-conditioning unit so that one of said external and internal air is led to said air-conditioning unit in accordance with a control signal;

(c) means for producing an output signal indicative of the concentration of a gas component included in said external air which may be led into said vehicle compartment; and

(d) controlling means responsive to said output signal for producing said control signal so that said switching means is controlled, said controlling means producing a relative value of the level of said output signal by detecting the difference between an actual level and a reference level, said switching means being controlled such that said internal air is recirculated to be led to said air-conditioning unit when said relative value exceeds a first predetermined value, said controlling means being arranged to detect the place where said motor vehicle travels by detecting the state of variation in said relative value, said first predetermined value being set to a higher value when it is detected that said motor vehicle travels in a city area and to a lower value when it is detected that said motor vehicle travels in a suburb, said switching means being controlled such that said external air is led to said air-conditioning unit when said relative value is continuously kept below a second predetermined value, which is smaller than the lower value of said first predetermined value, for a second predetermined period of time after it has been detected that said motor vehicle travels in a city area and when said relative value is continuously kept below said first predetermined value for a predetermined period of time, and it is detected that said motor vehicle travels in a suburb.

7. A method of controlling an air-conditioning system for use with a motor vehicle, which system is arranged to selectively assume an external air introduction mode in which external air is led through said air-conditioning system into the compartment of said vehicle and an internal air recirculation mode in which internal air in said compartment is recirculated through said air-conditioning unit, comprising the steps of:

(a) detecting the concentration of a gas component included in said external air which may be led into the compartment of said motor vehicle;

(b) comparing a value indicative of said concentration with a predetermined value;

(c) setting a predetermined period of time in a counter;

(d) detecting the count of said counter to see whether the predetermined time has passed when said value indicative of said concentration has been detected in the step (b) of comparing to be smaller than said predetermined value; and

(e) establishing said external air introduction mode when it has been detected in the step (d) of detecting that said predetermined period of time has passed;

(f) counting the number of times of detecting that said level is greater than or equal to said predetermined value and the number of times of detecting that a predetermined period of time has lapsed after said level becomes below said predetermined value; and

(g) changing said predetermined value in accordance with a count resulted from the counting step.

8. A method of controlling an air-conditioning system for use with a motor vehicle, which system is arranged to selectively assume an external air introduction mode in which external air is led through said air-conditioning system into the compartment of said vehicle and an internal air recirculation mode in which internal air in said compartment is recirculated through said air-conditioning unit, comprising the steps of:

(a) detecting the concentration of a gas component included in said external air which may be led into the compartment of said motor vehicle;

(b) producing a relative value of said concentration by detecting the difference between an actual value and a reference value;

(c) comparing said relative value with a first predetermined value;

(d) establishing said internal air introduction mode when said relative value is greater than or equal to said first predetermined value;

(e) comparing said relative value with a second predetermined value which is smaller than said first predetermined value when it has been detected in the step (c) of comparing that said relative value is smaller than said first predetermined value;

(f) setting a predetermined period of time in a counter;

(g) detecting the count of said counter to see whether the predetermined period of time has passed when said relative value has been detected in the step (e) of comparing to be smaller than said second predetermined value; and

(h) establishing said external air introduction mode when it has been detected in the step (g) of detecting that said predetermined period of time has passed.

9. A method of controlling an air-conditioning system for use with a motor vehicle, which system is arranged to selectively assume an external air introduction mode in which external air is led through said air-conditioning system into the compartment of said vehicle and an internal air recirculation mode in which internal air in said compartment is recirculated through said air-conditioning unit, comprising the steps of:

(a) detecting the concentration of a gas component included in said external air which may be led into the compartment of said motor vehicle;

(b) producing a relative value of said concentration by detecting the difference between an actual value and a reference value;

(c) setting a first predetermined value to a higher value when a variable is below a predetermined number, and to a lower value when said variable is greater than or equal to said predetermined number;

(d) comparing said relative value with said first predetermined value;

(e) decreasing said variable by 1 when said relative value is greater than or equal to said first predetermined value;

(f) setting a first predetermined period of time in a first down counter;

(g) establishing said internal air introduction mode after the step (f) of setting;

(h) detecting the count of said first down counter to see whether said first predetermined period of time has passed when said relative value is smaller than said first predetermined value;

(i) increasing said variable by 1 when it has been detected in the step (h) of detecting that said first predetermined period of time has passed;

(j) setting said first predetermined period of time in said first down counter;

(k) detecting said first predetermined value to see whether said motor vehicle travels in a city area or a suburb either after said step (j) of setting or when it has been detected that said first predetermined period of time has not passed yet;

(l) comparing said relative value with a second predetermined value which is smaller than the lower value of said first predetermined value when it has been detected in the step (k) of detecting that said motor vehicle travels in a city area;

(m) setting a second predetermined period of time in a second down counter either after the step (g) of establishing or when it has been detected in the step (l) of comparing that said relative value is greater than or equal to said second predetermined value;

(n) detecting the count of said second down counter to see whether the second predetermined period of time has passed when said relative value has been detected in the step (l) of comparing to be smaller than said second predetermined value; and

(o) establishing said external air introduction mode either when it has been detected in the step (n) of detecting that said second predetermined period of time has passed or when it has been detected in the step (k) of detecting that said motor vehicle travels in a suburb.

10. An air-conditioning system for use with a motor vehicle, comprising:

(a) an air-conditioning unit arranged to control the temperature of air in the compartment of said motor vehicle by either introducing external air or recirculating internal air in said compartment;

(b) switching means for switching the airflow led to said air-conditioning unit so that one of said external and internal air is led to said air-conditioning unit in accordance with a control signal;

(c) means for producing an output signal indicative of the concentration of a gas component included in said external air which may be led into said vehicle compartment; and

(d) controlling means responsive to said output signal for producing said control signal so that said switching means is controlled, said switching means being controlled such that said internal air is recirculated to be led to said air-conditioning unit when said level of said output signal exceeds a first predetermined value, and said external air is led to said air-conditioning unit when said level of said output signal is continuously kept below a second predetermined value, for a predetermined period of time, said controlling means being arranged to detect the place where said motor vehicle travels by detecting the state of variation in the level of said output signal, said controlling means being arranged to change said first predetermined value such that a higher value is set when it is detected that said motor vehicle travels in a city area, and a lower value is set when it is detected that said motor vehicle travels in a suburb.

11. An air-conditioning system for use with a motor vehicle, comprising:

(a) an air-conditioning unit arranged to control the temperature of air in the compartment of said motor vehicle by either introducing external air or recirculating internal air in said compartment;

(b) switching means for switching the airflow led to said air-conditioning unit so that one of said external and internal air is led to said air-conditioning unit in accordance with a control signal;

(c) means for producing an output signal indicative of the concentration of a gas component included in said external air which may be led into said vehicle compartment; and

(d) controlling means responsive to said output signal for producing said control signal so that said switching means is controlled, said switching means being controlled such that said internal air is recirculated to be led to said air-conditioning unit when said level of said output signal exceeds a first predetermined value, and said external air is led to said air-conditioning unit when said level of said output signal is continuously kept below a second predetermined value, which is smaller than said first predetermined value, for a predetermined period of time, said controlling means being arranged to detect the place where said motor vehicle travels by detecting the state of variation in the level of said output signal, said controlling means being arranged to detect the state of variation in one direction by a predetermined amount each time said level is detected to be greater than or equal to said first predetermined value and in opposite direction by said predetermined amount each time it has been detected that said level is kept below said first predetermined value for a predetermined period of time, and by detecting the value of said variable, said controlling means being arranged to change said first predetermined value such that a higher value is set when it is detected that said motor vehicle travels in a city area, and a lower value is set when it is detected that said motor vehicle travels in a suburb.