JP2000135919A - Intake door control device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the generation of a malfunction so as to improve product quality by inhibiting the execution of normal intake door control in a state unfit to actuate an intake door control device due to the failure of an exhaust gas sensor or the like. SOLUTION: This control device is provided with an intake switching control means (d) for controlling an intake door (a) to be in an outside air mode in the clean state of outside air low in exhaust gas concentration and to be in an internal air mode in the polluted state of outside air high in exhaust gas concentration. In this case, the intake switching control means (d) is provided with a control execution propriety judging means (e) for judging whether to be in a state fit for the intake switching control means (d) to execute normal intake switching control, and a fail-safe control means (f) for inhibiting the execution of normal intake switching control when judging the execution of normal intake switching control improper, and executing specified fail-safe control which is control for preventing the generation of a malfunction generated in the case of executing normal intake switching control.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an intake system for detecting the concentration of exhaust gas outside a vehicle compartment, and setting the side to the outside air introduction mode when the outside air is clean, and setting the side to the inside air (circulation) mode when the outside air is contaminated. Belongs to the technical field of door control devices.

[0002]

2. Description of the Related Art Conventionally, as an intake door control device, for example, a device described on pages 149 to 152 of "Academic Lecture Meeting of the Society of Automotive Engineers of Japan, Preprint 975" (issued in October 1997) is known. Are known. In the above conventional source, it is provided at the outside air intake of the air conditioner unit mounted on the car,
An intake door that switches between an outside air mode and an inside air mode by an intake door actuator, an exhaust gas sensor that is installed in a vehicle and detects an exhaust gas concentration of the outside air,
A sensor signal from the exhaust gas sensor is input, and it is determined whether the outside air is in a clean state or a contaminated state based on whether the gas concentration sensor value is equal to or greater than a set threshold value. A device is described that includes a control unit that controls the drive of a servomotor that operates the intake door so as to be in the inside air mode in a polluted state.

[0003]

However, in the above-mentioned conventional apparatus, a failure such as disconnection or short circuit may occur in the exhaust gas sensor. In such a case, the output of the exhaust gas sensor is the maximum output or the minimum output. State, which corresponds to a state in which a signal indicating that the exhaust gas concentration is extremely low or extremely high is being output. Therefore, the control unit performs control based on an erroneous signal output due to a failure from the exhaust gas sensor, and keeps the intake door fully open in the former case and fully closed in the latter case. Control.
Therefore, if the intake door is kept fully open, depending on the driving conditions, outside air with a high exhaust gas concentration may be introduced and the occupant may feel uncomfortable, and the intake door may be fully closed. Without ぱ, the window glass may be fogged by a low temperature outside the vehicle and a large temperature difference from the temperature inside the vehicle, or by moisture caused by exhalation of a passenger.

[0004] Further, the risk of fogging of the window glass as described above may occur not only when the exhaust gas sensor fails as described above, but also when the intake door control is normally performed. That is, when the exhaust gas concentration of the outside air is high, the intake door is fully closed based on the intake door control. However, if the outside air temperature is low and the temperature difference from the vehicle interior temperature is large, or if the fan of the air conditioner unit is not driven while the outside air temperature is low, if the intake door is kept fully closed for a long time, The window glass may be fogged.

Further, in the above prior art, the intake door control device and the operation of the air conditioner unit are not related to each other. However, when the air conditioner unit is operated at a high load, the intake door control device operates the intake door control device. If the air conditioner unit is fully closed or fully opened, the load on the air conditioner unit will be too high and the intended performance may not be exhibited.In particular, if the intake door is fully opened during rapid cooling, the load will be too large. .

SUMMARY OF THE INVENTION The present invention has been made in view of the above-described problem, and is intended to prevent normal intake door control from being performed in a state where it is difficult to operate the intake door control device, for example, when an exhaust gas sensor fails. Therefore, the purpose is to prevent the occurrence of defects and thereby improve the product quality.

[0007]

In order to achieve the above object, the present invention, as shown in the claim correspondence diagram of FIG. 1, is provided at a suction port of an on-vehicle air conditioner unit au, and is provided with an outside air by an intake door actuator g. An intake door a that can be switched between an outside air mode in which the introduction side is the most open and an inside air mode in which the outside air introduction side is the most closed, an exhaust gas sensor b that is installed in the vehicle and detects an exhaust gas concentration of the outside air,
Input the sensor signal from this exhaust gas sensor b,
An exhaust gas concentration calculating means c for calculating an exhaust gas concentration based on a sensor signal; and, based on the exhaust gas concentration obtained by the exhaust gas concentration calculating means c, an outside air mode in an outside air clean state where the exhaust gas concentration is low, Inhalation switching control means d for controlling the driving of intake door actuator g so as to be in the inside air mode in the outside air pollution state where the exhaust gas concentration is high.
In the intake door control device comprising: a control execution determination unit that determines whether the suction switching control unit d is in a state in which the normal suction switching control may be performed by the suction switching control unit d. e, when the control execution availability determination means e determines that the normal suction switching control cannot be executed, the normal suction switching control is prohibited, and a problem occurs when the normal suction switching control is executed. And fail-safe control means f for executing a predetermined fail-safe control which is control not to be performed. Therefore, when the control execution possibility determination means e determines that the normal suction switching control cannot be executed (for example, when the exhaust gas sensor b is out of order or the intake door a is not fully closed), a failure occurs. The safe control means f prohibits the execution of the normal suction switching control and executes a predetermined fail-safe control, thereby preventing the occurrence of a problem that occurs when the normal suction switching control is executed.

[0008] In the intake door control device according to the first aspect, the fail-safe control executed by the fail-safe control means f is a control that causes the intake door a to be fully opened. Is preferred. Therefore, it is possible to prevent the window glass from fogging due to the intake of outside air.

According to a third aspect of the present invention, in the intake door control device according to the first aspect, the suction switching control means d is provided in an air conditioner control means h for controlling the air conditioner unit ac. The air conditioner control means h includes an automatic air conditioner control means j for automatically determining an air volume, an air temperature, an air outlet, and the like based on detection of environmental factors relating to a temperature environment in the vehicle cabin, and the fail safe control means f Except at the time of the fail-safe control, the suction switching control means d controls the driving of the intake door actuator g in preference to the automatic air-conditioning control by the automatic air-conditioning control means j. It is preferable that the fail-safe control is execution of the automatic air conditioning control by the automatic air conditioning control means j. Therefore, in the normal case where the control execution possibility determination means e determines that the suction switching control is executable, the control of the intake door a by the suction switching control means d according to the state of the outside air detected by the exhaust gas sensor b is prioritized, and the exhaust It is possible to balance the prevention of gas intrusion into the vehicle interior and the ventilation, and to control the suction switching of the intake door a by the suction switching control means d in the fail-safe state in which the control execution possibility determining means e determines that the suction switching control cannot be performed. And the execution of the automatic air-conditioning control by the automatic air-conditioning control means j can be continued, so that the temperature environment in the vehicle compartment can be maintained in a favorable state, so that the fogging of the window glass can be prevented.

According to a fourth aspect of the present invention, in the intake door control device according to the first to third aspects,
The control execution availability determination means e is configured to detect the presence or absence of a failure in the exhaust gas sensor b, determine that the suction switching control can be performed when no failure is detected, and determine that the suction switching control cannot be performed when the failure is detected. Is preferred. Therefore, when the exhaust gas sensor b fails, the control execution possibility determination means e determines that the suction switching control cannot be executed, and a predetermined fail-safe control is executed. Even if the exhaust gas concentration is extremely high or the outside air is extremely clean, the suction switching control means d does not execute the control of opening and closing the intake door a based on the erroneous signal, and Problems such as fogging can be prevented.

According to a fifth aspect of the present invention, in the intake door control device according to the first to fourth aspects, the control execution availability determination means e determines whether the air conditioner unit au is in a high load state when the air conditioner unit au is in a high load state. When the temperature is equal to or lower than the first predetermined temperature, when the outside air temperature is equal to or lower than a second predetermined temperature higher than the first predetermined temperature, and when the fan is stopped, the suction switching control is performed. It is preferable to configure so that it is determined that the execution cannot be performed, and otherwise, it is determined that the suction switching control can be performed. Here, the first predetermined temperature is, for example, a temperature within a range of 0 to -5 ° C. at which the window glass may be fogged even without turning the fan, and the second predetermined temperature is If the fan is running, the window glass may be fogged. For example, 8 to 15 degrees Celsius
Temperature within the range. Therefore, at least, when the air conditioner unit au is in a high load state, the load is further increased by fully opening or closing the intake door a, and when the outside air temperature is equal to or lower than the first predetermined temperature, the intake door a is fully closed and the window glass is opened. Fogging and preventing the window glass from fogging by fully closing the intake door a when the outside air temperature is equal to or lower than a second predetermined temperature higher than the first predetermined temperature and the fan is stopped. Can be.

[0012]

(Embodiment 1) Embodiment 1 corresponds to the first to fifth aspects of the present invention. FIG. 2 is an overall system diagram showing the intake door control device according to the first embodiment. In FIG. 2, 1 is an intake door, 2 is an outside air inlet, 3 is an inside air inlet, 4 is a deodorizing filter, 5 is a blower,
6 is a blower motor, 7 is a servo motor (corresponding to an intake door actuator in the claims), 8 is an exhaust gas sensor, 9 is a door position sensor, 10 is a vehicle speed sensor, 11 is an outside temperature sensor, and 12 is an air conditioner control unit. , 13 is a control unit, 14 is a blower air volume signal, 15 is a compressor signal, and 16 is a mode signal.

The intake door 1 is arranged on the suction side of the blower 5, and is driven by a servomotor 7 as an intake door actuator. Then, the fresh position (FRE) of the intake door 1 that blocks the inside air inlet 3
Then, it becomes 100% of outside air introduction rate, that is, outside air mode,
Conversely, at the recirculation position (REC) of the intake door 1 that blocks the outside air intake port 2, the outside air introduction rate of 0%,
That is, the inside air mode is set. In addition, the intake door 1
A deodorizing filter 4 for preventing exhaust gas odor by activated carbon or the like is arranged between the blower 5 and the blower 5.

The exhaust gas sensor 8 outputs a voltage signal Vs corresponding to the gas concentration by utilizing a change in resistance value due to the presence of gas. That is, the gas sensor element is composed of a gas detection section provided on a ceramic substrate with SnO2 as a main component, and a heater section for performing heating for promoting a reaction to the gas. When reacted, the electrical resistance changes due to the oxidation-reduction reaction. The exhaust gas sensor 8 is installed on a front grille that can efficiently and efficiently detect exhaust gas.
By providing the exhaust gas sensor 8 on the front grille portion that can detect the exhaust gas at the upstream side of the intake door 1 as the flow of air, the exhaust gas can be more reliably prevented from entering the passenger compartment. As shown in the figure, the exhaust gas sensor 8 has a first sensor S1 and a second sensor S1.
The sensor S2 has two sensing functions, one for a gasoline engine and one for a diesel engine. When the exhaust gas sensor 8 fails, the occurrence phenomenon differs depending on the failed sensor and the failure mode. FIG. 5 is a characteristic diagram showing the occurrence phenomena for each failure mode. When the first sensor S1 fails, the output voltage becomes 0 in the open (disconnection) mode and the voltage indicating the air clean state where the exhaust gas concentration is the lowest. In the short-circuit mode, the output voltage Vgs becomes the battery voltage Vdd, which is higher than the voltage indicating the highest exhaust gas concentration. On the other hand, the second sensor S2
In the short (short circuit) mode, the output voltage becomes 0 and becomes lower than the voltage indicating the lowest air clean state in the short (short circuit) mode. Conversely, in the open (disconnection) mode, the output voltage Vgs becomes lower. The battery voltage becomes Vdd, which is higher than the voltage indicating the highest exhaust gas concentration. That is, when the exhaust gas sensor 8 normally detects the exhaust gas concentration, the output voltage V
gs is configured to be, for example, an output voltage in a range from about 2 V to about 5 V. Therefore, at the time of failure, the output voltage Vgs is out of the normal output range.

The door position sensor 9 detects a door opening position of the intake door 1 and provides a signal processing circuit 13 with door opening feedback information. The vehicle speed sensor 1
0 indicates the vehicle speed Vc and outputs the vehicle speed information to the signal processing circuit 13.
Give to. The outside temperature sensor 11 detects outside temperature AMB and provides outside temperature information to the signal processing circuit 13.

The air conditioner control unit 12
Is equivalent to the automatic air conditioning control means in the claims,
A variety of sensors detect changes in the vehicle interior temperature due to changes in the outside air temperature, the amount of solar radiation, changes in the number of occupants, etc., and once set to the desired temperature, keep the vehicle interior temperature constant. It has a heating and temperature control unit using engine and cooling water, and automatically controls air conditioning by using a microcomputer to control the temperature of the blown air, the amount of the blown air, and the switching of the inlet and outlet. That.

The signal processing circuit 13 is a single control unit provided in the air conditioner control unit 12 and corresponds to the suction switching control means described in the claims. At 8, control is performed to automatically switch the suction port by driving and controlling the intake door 1. This signal processing circuit 1
Reference numeral 3 includes, as internal signals, a blower air volume signal based on a blower motor voltage value, a compressor signal for monitoring on / off of an air conditioner, whether or not a differential mode (DEF), or an automatic recirculation mode (auto REC). A mode signal for monitoring whether or not the signal is provided.

Next, the operation will be described. [Regarding Intake Door / Ventilation Door Control Operation] FIG. 3 is a flowchart showing the flow of the intake door / ventilation door control operation executed in the signal processing circuit 13 of the first embodiment. Each step will be described below.

In step 30, a gas sensor value process for obtaining a calculation gas sensor value FGSC from a gas sensor A / D value GSAD described later is performed by a subroutine call. In step 31, it is determined whether or not 60 seconds (sufficient time from when the power is turned on until the sensor output stabilizes) have elapsed since the ignition switch was switched from OFF to ON. Before 60 seconds,
Proceeding to step 32, the timer counter of the delay timer from REC to FRE is initialized.

In step 35, the control characteristic graph shown in FIG. 6 and the calculation gas sensor value FGSC obtained in step 30 (this value is inversely related to the exhaust gas concentration, that is, the smaller the exhaust gas concentration, the smaller the value. Is determined, and the delay time Rsec is set. This delay time Rsec may be a fixed value, or may be a variable value such that the delay time Rsec becomes longer as the vehicle speed decreases.

In the following step 351, it is determined whether or not the calculation gas sensor value FGSC = 0, and FGSC ≠
If it is 0, the process directly proceeds to step 36, where FGSC = 0.
In the case of, the routine proceeds to step 352, where the target door opening FTI =
After setting to 0, the process proceeds to step 36. Step 36
Then, it is determined whether or not the movement is in the REC → FRE direction. If the determination is NO (when the movement is in the FRE → REC direction), the process proceeds to step 37; if the determination is YES (in the case of the movement in the REC → FRE direction), Proceed to step 39. In step 37, the timer counter of the delay timer is initialized. In step 38, the door opening determined in step 35 is set as the target door opening FTI.

In step 39, it is determined whether the delay time Rsec has elapsed. If the delay time Rsec has elapsed, the process proceeds to steps 37 and 38,
Initialization of the timer counter and setting of the target door opening FTI are performed. In step 40, before the delay time Rsec elapses, the target door opening FTI is held. However, fully closed (F
The continuous time for maintaining the ULREC is set to a maximum of 15 minutes or less in consideration of an increase in the CO2 concentration in the vehicle interior. This continuous time can be controlled in consideration of an increase in the CO2 concentration in the vehicle cabin by, for example, detecting the number of occupants with an occupant sensor and shortening the number as the number of occupants increases.

In step 41, when the target door opening FTI of the intake door 1 set in step 38 or step 40 is in the inside air mode, a negative pressure prevention control is executed to prevent the vehicle compartment from becoming negative pressure. If necessary, control for inhibiting control to the inside air mode is executed. This negative pressure prevention control will be described later with reference to FIG. In step 42, a command value for obtaining the target door opening degree FTI of the intake door 1 set in step 41 is output to the servomotor 7.

[Regarding Intake Door Opening Control] FIG. 6
In FIG. 7, the solid line shows the control characteristics at the normal time, in which the first threshold value TH1, the second threshold value TH2, and the third threshold value TH3 are set as the control threshold values. When the sensor value FGSC is less than the first threshold value, the intake door 1 is set to the inside air mode with the outside air introduction rate of 0%, and when the calculation gas sensor value FGSC is equal to or more than the second threshold value TH2, the intake door 1 is set to the outside air introduction rate of 100. % In the outside air mode, and the outside air introduction rate of the intake door 1 is a predetermined percentage (40% in the first embodiment) in a region where the calculation gas sensor value FGSC is in the range from the third threshold TH3 to the second threshold TH2. And the calculation gas sensor value FGSC is changed from the first threshold value TH1 to the third threshold value T.
In the region up to H3, the variable opening mode is set so that the door opening is steplessly changed to the inside air mode side as the calculation gas sensor value FGSC becomes lower. As will be described later, a characteristic B indicated by a dotted line in FIG. 6 is a control characteristic at the time of high-speed running at a vehicle speed of 100 km / h or more. In this case, the intake door 1 is controlled based on the fourth threshold value TH4. Control is performed to switch between the inside air mode and the outside air mode. The control characteristic graph is set in advance based on the correlation characteristics of the calculation gas sensor value FGSC with respect to the odor intensity and the CO concentration in the vehicle cabin obtained by the actual vehicle running test.

In the first embodiment, when controlling the opening degree of the intake door 1 from the FRE side to the REC side, the timer counter is initialized, the opening degree is immediately changed, and the invasion of exhaust gas (odor) is prevented. Prevent surely. On the other hand, when the opening degree of the intake door 1 is controlled from the REC side to the FRE side, a delay time Rsec is set from when the control is determined to when the command value is actually output, so that the exhaust gas concentration becomes lower. When the outside air introduction rate is increased in accordance with the change to the above, the remaining exhaust gas is not introduced so that the user does not feel odor.

[Gas Sensor Value Processing] FIGS. 4 and 5 are flowcharts showing the flow of gas sensor value processing performed by the signal processing circuit 13. Step 50
Step 57 is a step of calculating a gas sensor value GSC (0% to 100%) indicating the exhaust gas concentration from the sensor measurement value by using the gas sensor A / D value GSAD and the clean air value GSMX. Instead of directly converting GSAD to gas concentration, the clean air value GS
By using MX as a reference value, the variation, temperature, and humidity characteristics of the sensor alone are corrected (corresponding to the exhaust gas concentration calculating means c).

In step 50, the gas sensor A / D value GSAD is calculated by the equation GSAD = 255-GSAD. The GSAD in the equation is the exhaust gas sensor 8
The gas sensor A / D value obtained by the measurement read in the current processing is subtracted from the value of 255 because the degree of air contamination is represented by 255 bits and the characteristics are inverted. Therefore, the maximum clean air value of the gas sensor A / D value GSAD is 255,
The maximum dirty air value is zero.

At step 51, it is determined whether or not a set time of 60 seconds (sufficient time from when the power is turned on until the sensor output is stabilized) has elapsed since the ignition switch was turned from OFF to ON.
The process proceeds to step 53 if YES. In step 52, a preset initial value is set as the gas sensor A / D value GSAD before 60 seconds have elapsed since the ignition switch was turned from OFF to ON. In addition, the gas sensor A / D value set in this manner is used in a later-described step 56 in a clean air value GSM.
It will be set as the initial value of X. Step 53
After 60 seconds have passed since the ignition switch was turned from OFF to ON, the gas sensor A / D value GSAD obtained in step 50 is compared with the clean air value GSMX indicating that the air is the cleanest. . Here, the clean air value GSMX is a value indicating that the air is the cleanest from the time when the ignition switch is turned on until the previous processing, and is stored in the rewritable RAM.

In step 54, if the determination in step 53 is YES, that is, if GSAD> GSSMS, the gas sensor A / D value GSAD is compared with the limit value of the clean air value GSMX. Here, the clean air value GSMX
Is a predetermined limit value because there is a limit to the value no matter how clean the air is (maximum limit value 255). In step 55, when GSAD> limit value in step 54, the gas sensor A
It is determined that the / D value GSAD is an abnormal value, and the limit value is stored as the clean air value GSMX.
Proceed to. In step 56, in step 54, GSAD ≦
When it is the limit value, it is determined that the gas sensor A / D value GSAD is a normal value, and the gas sensor A / D value GSAD
Is stored as the clean air value GSMX. Step 57
In, the ratio of the gas sensor A / D value GSAD to the clean air value GSMX, which is the reference value, is defined as the gas sensor value (exhaust gas concentration) GSC.

In FIG. 5, steps 58 to 6
6 performs a differentiation process of the gas sensor value (exhaust gas concentration) GSC (0% to 100%) obtained in step 57, and determines the final calculation gas sensor value FGSC (0 to 0) to determine the target door opening FTI. (255 bits).

In step 58, it is determined whether the differentiation time ΔAsec has elapsed. In step 59, the previous gas sensor value OGSC and the current gas sensor value G
A GSC differential value DTGS, which is a sensor value change amount per time ΔAsec, is obtained from the difference from the SC. In step 60, it is determined whether the GSC differential value DTGS is larger than 0, that is, whether DTGS> 0.

In step 61, when the determination in step 60 is DTGS ≦ 0, that is, when the change in the gas concentration state is in the stable or clean direction, the GSC differential value DTGS is set to DTGS = 0. In step 62, when the determination in step 60 is DTGS> 0, that is, when the gas concentration state change is in the dirt direction, whether or not the previous GSC differential value 0 DTGS = 0, that is, when the previous gas concentration state change is It is determined whether the direction is stable or clean. In step 63, it is determined whether or not the GSC differential value DTGS, which is the current change in the gas concentration state, is equal to or greater than the differential threshold value DGC, which is the set value in the dirt direction.

In step 64, the determination in step 62 that the previous gas concentration state change is in the stable or clean direction and the determination in step 63 that the current GSC differential value DTGS is equal to or greater than the differential threshold value DGC. Assuming that the outside air moves in the dirt direction based on the
C = 0, that is, a value at which the intake door 1 is fully closed. In step 65, the GSC differential value DTGS
Is set to the previous GSC differential value 0DTGS. In step 66, the gas sensor value GSC is set as the calculation gas sensor value FGSC. As shown in FIG. 6, the gas sensor value for calculation FGSC is 100% indicating that the air is the cleanest, and 0% indicates that the exhaust gas concentration is the highest, that is, dirty.

[Regarding Fail-Safe Control] In the first embodiment, two types of fail-safe control, ie, fail-safe control-1 shown in FIG. 8 and fail-safe control-2 shown in FIG. 9, are performed. The fail-safe control-1 is a fail-safe control for preventing inconvenience when the exhaust gas sensor 8 fails, and the fail-safe control-2 is a fail-safe control for preventing fogging of the window glass. This control is for safe control and high-speed running.

In FIG. 8, in step 81, the gas sensor A / D value GSAD is set to a predetermined value Vdd × 0.1
V (= a value smaller than the minimum value of the output value when the exhaust gas sensor 8 is normal) is determined. If the value is smaller than the predetermined value, the process proceeds to step 84, where the sensor failure determination timer SFT is performed. Is greater than or equal to 30 seconds, and if GSAD ≧ Vdd × 0.1V, step 82
Proceed to. In step 82, the gas sensor A / D value GS
It is determined whether or not AD is larger than a predetermined value Vdd × 0.9 V (= a value larger than the maximum value of the output value when the exhaust gas sensor 8 is normal), and GSAD> Vdd ×
If 0.9 V, the process proceeds to step 84, where GSAD ≦ Vd
If d × 0.9 V, the routine proceeds to step 83, where the sensor failure determination timer SFT is cleared. Therefore, the gas sensor A / D value GSAD is Vdd × 0.1V ≦ GS
If AD ≦ Vdd × 0.9 V, the sensor failure determination timer SFT is cleared, and intake door control is executed, but the gas sensor A / D value GSAD is
If the state outside this range exceeds 30 seconds, it is determined that the sensor has failed, the intake door control is prohibited, and only the automatic air conditioning control by the microcomputer in the control unit 12 is executed.

Next, fail-safe control-2 shown in FIG.
When the vehicle is driven to be in the inside air mode by controlling the intake door corresponding to the exhaust gas even though the operation for removing the fogging of the window is performed during running, the fogging of the window will not easily disappear. Therefore, as shown in step 91 of FIG. 9, when the differential mode, which can be estimated as an operation for removing window fogging, is selected, the exhaust gas intake door control is prohibited and the automatic air conditioning control is executed. Steps 94 and 95 of FIG.
As shown in the figure, when the outside air temperature is equal to or lower than the first predetermined temperature of 12 ° C. and the fan is not rotating, and when the outside air temperature is lower than the second predetermined temperature of −2 ° C. Also in this case, if the inside air mode is set by the exhaust gas corresponding intake door control, the window may be fogged. Therefore, the intake door control is prohibited and the automatic air conditioning control is executed.

In the automatic air-conditioning control, when the heat load is large and the cool-down control is executed, and when the air is clean and the outside air mode is set by the intake door control, the high load state cannot be easily eliminated. Therefore, as shown in step 92, even under a high load, the intake door control is prohibited and the automatic air conditioning control is executed. Incidentally, at such a high load, the intake door is controlled to the inside air mode by the automatic air conditioning control.

As described above, the vehicle speed is 100 km.
/ H or higher, the control characteristic graph B in FIG.
Are selected. That is, at the time of high-speed running, the ingress and departure of the environment where the exhaust gas concentration is high is performed in a short time, and the exhaust gas concentration around the exhaust gas sensor 8 becomes lean due to the ram pressure. , So that the response can be made sensitively in a short time.

[External air contamination prediction control] When the door opening / closing control is performed by the gas concentration control, if the nose of a person smells the most, such as when a single odor is generated due to the start of a preceding vehicle or a vehicle interruption, etc. If the computational gas sensor value FGSC indicating the gas concentration does not exceed the set threshold value even if the user feels the situation, the intake door 1 is not fully closed, and the response time of the door closing operation delays the exhaust gas. Will allow the car to enter the cabin.

Therefore, the differential value D of the gas sensor value GSC
It is conceivable to perform control to close the door to the REC only under the present differential value condition that TGS is a value indicating an increase in gas concentration. However, in this case, since the control is performed only with the magnitude of the differential value DTGS of this time, in a combination with a system in which noise easily enters or a gas sensor with an excessively good response, the control is frequently closed to the REC. And it becomes very annoying. In addition, as a result, the execution time for closing to the REC becomes longer, so that the control is performed with poor ventilation efficiency in the vehicle interior.

On the other hand, in the first embodiment, as shown in steps 62, 63 and 64 in FIG. 5, the previous change in the gas concentration state in step 62 is in the dirt direction, and When it is determined that the GSC differential value DTGS is greater than or equal to the differential threshold value DGC, it is predicted that the nose of a person will be the most smell due to the occurrence of a single odor in the future. The gas sensor value GSC is set to GSC = 0 based on the prediction of the shift to the dirt direction.
Therefore, according to the processing in step 35 of the flow shown in FIG. 3, the intake door 1 is in the inside air mode, that is, fully closed.

As described above, the change in the gas concentration state at the previous time is stable as shown in FIG.
This GSC only when it is in the clean direction as shown in
Because the door closing control is performed according to the magnitude of the differential value DTGS, high ventilation response is ensured only when absolutely necessary, such as when a single odor is generated, while ensuring good ventilation efficiency without the hassle of frequently entering the door closing control. , The door closing control is performed.

(Other Embodiments) In the first embodiment, fail-safe control-1 and fail-safe control-2
The above two types of fail-safe control are executed. However, only one of them may be executed. In the fail-safe control-2, it is possible to cope with a high load in step 92. , At least one of the control corresponding to the outside air temperature and the driving state of the fan in step 94 and the control corresponding to only the outside air temperature in step 95 may be executed.
Even a combination of these two controls. In the first embodiment, an example is shown in which the characteristic graph of the control of the intake door 1 in FIG. 6 is set with threshold values TH1 to TH4 for determining the intake door opening degree by correlating the characteristic graph with the odor intensity based on the actual vehicle measurement. However, the setting and magnitude of these thresholds TH1 to TH4 are arbitrary. Further, in the first embodiment, the intermediate opening mode is set between the third threshold TH3 and the second threshold TH2 in this control characteristic graph. The setting of the threshold value TH3 may be omitted, and the opening may be variably controlled within the range of the outside air introduction rate of 0% to 100% in the entire range between the first threshold value and the second threshold value. . Further, in the first embodiment, an example is shown in which control using a control characteristic graph is further combined with outside air contamination prediction control based on a gas concentration differential value so that higher quality control can be executed. Even if the control does not combine the dirt prediction control, the desired effect can be obtained. In the first embodiment,
The calculation gas sensor value FGS is used as a value indicating the gas concentration.
Although the example using C is shown, the gas sensor value GSC based on the clean air value GSMX may be used as the gas concentration calculation value, or the value obtained by A / D conversion of the measurement value from the exhaust gas sensor may be used. May be.

[0044]

As described above, claims 1 to 5
In the described invention, when there is a possibility that a malfunction may occur when the normal suction switching control is performed, such as in a state in which the exhaust gas sensor fails or a malfunction that completely closes the intake door occurs, a fail-safe The control means executes the predetermined fail-safe control, thereby preventing the occurrence of a failure and improving the product quality. According to the second aspect of the invention, at the time of the fail-safe control, an effect is obtained in which the outside air is taken in to prevent the window glass from fogging and the product quality can be improved. According to the third aspect of the invention, the control of the intake door by the suction switching control means according to the state of the outside air detected by the exhaust gas sensor is normally performed when the control execution determination means determines that the suction switching control is executable. By prioritizing, it is possible to balance the prevention of exhaust gas intrusion into the vehicle interior and the ventilation, and at the time of fail-safe when the control execution possibility determining means determines that the suction switching control cannot be executed, the intake door by the suction switching control means In addition to prohibiting the suction switching control, the execution of the automatic air-conditioning control by the automatic air-conditioning control means can be continued, the temperature environment in the vehicle compartment can be maintained in a favorable state, and the fogging of the window glass can be prevented. The effect that the product quality can be improved can be obtained. According to the fourth aspect of the present invention, when the exhaust gas sensor fails, predetermined fail-safe control is executed, and based on an erroneous signal from the failed exhaust gas sensor, opening / closing control of the intake door is executed. Can prevent the occurrence of problems such as fogging of the window,
The effect that the product quality can be improved can be obtained. In the invention according to claim 5, at least when the air conditioner unit is in a high load state, the load is further increased by fully opening and closing the intake door, and when the outside air temperature is equal to or lower than the first predetermined temperature. When the intake door is fully closed and the window glass is fogged, and when the outside air temperature is lower than or equal to a second predetermined temperature higher than the first predetermined temperature and the fan is stopped, the intake door is fully closed and the window glass is fogged. , Can be prevented,
Thereby, there is an effect that the product quality can be improved.

[Brief description of the drawings]

FIG. 1 is a diagram corresponding to a claim showing an intake door control device of the present invention.

FIG. 2 is an overall system diagram showing an intake door control device according to the first embodiment.

FIG. 3 is a flowchart illustrating a flow of an intake door control operation performed by the signal processing circuit according to the first embodiment;

FIG. 4 is a flowchart showing a flow of gas sensor value processing performed by the signal processing circuit of the first embodiment.

FIG. 5 is a flowchart showing a flow of gas sensor value processing (differential processing) performed by the signal processing circuit of the first embodiment.

FIG. 6 is a characteristic graph (a target door opening characteristic diagram) used in the exhaust gas concentration corresponding door control performed by the signal processing circuit of the first embodiment.

FIG. 7 is a circuit diagram of an exhaust gas sensor.

FIG. 8 is a flowchart of fail-safe control-1 performed by the signal processing circuit of the first embodiment.

FIG. 9 is a flowchart of a fail-safe control-2 performed by the signal processing circuit according to the first embodiment.

FIG. 10 is a characteristic diagram showing a reduction in the number of occurrences of two exhaust gas sensors in different failure modes.

FIG. 11 is a diagram showing a gas concentration differential value change pattern in which control for completely closing an intake door is executed in the outside air contamination prediction control according to the first embodiment.

[Explanation of symbols]

 a intake door b exhaust gas sensor c exhaust gas concentration calculating means d suction switching control means e control execution feasibility determining means f fail safe control means g intake door actuator h air conditioner control means j automatic air conditioning control means au air conditioner unit 1 intake door 2 outside air Inlet 3 Inside air inlet 4 Deodorizing filter 5 Blower 6 Blower motor 7 Servo motor 8 Exhaust gas sensor 9 Door position sensor 10 Vehicle speed sensor 11 Outside temperature sensor 12 Air conditioner control unit 13 Signal processing circuit 14 Blower air volume signal 15 Compressor signal 16 Mode signal

Claims (5)

[Claims] 1. An intake door provided at a suction port of an air-conditioning unit mounted on a vehicle, wherein an intake door actuator switches between an outside air mode in which an outside air introduction side is most open and an inside air mode in which the outside air introduction side is closed most, and is installed on a vehicle. An exhaust gas sensor for detecting an exhaust gas concentration of the outside air, an exhaust gas concentration calculating means for inputting a sensor signal from the exhaust gas sensor and calculating an exhaust gas concentration based on the sensor signal; Based on the exhaust gas concentration obtained by the means, the intake air switching is performed to control the drive of the intake door actuator so that the outside air mode is set in the clean state of the outside air where the exhaust gas concentration is low, and the inside air mode is set in the case of the outside air polluted with the high exhaust gas concentration. And an intake door control device comprising: A control execution determination unit that determines whether the suction switching control unit is in a state in which the normal suction switching control may be executed, and a case where the control execution determination unit determines that the normal suction switching control cannot be executed. Fail-safe control means for performing a predetermined fail-safe control, which is a control for inhibiting execution of the normal suction switching control and preventing a problem that occurs when the normal suction switching control is executed, An intake door control device, which is provided. 2. The intake door control device according to claim 1, wherein the fail-safe control executed by the fail-safe control means is a control for bringing the intake door to a fully opened state. 3. The air-conditioning control means for controlling the air-conditioning unit is provided in the air-conditioning control means. Automatic air-conditioning control means for executing automatic air-conditioning control for automatically determining an outlet temperature, an air outlet, and the like, except for the fail-safe control by the fail-safe control means, wherein the suction switching control means comprises the automatic air-conditioning control means Wherein the drive of the intake door actuator is controlled prior to the automatic air conditioning control by the automatic air conditioning control means, and the fail safe control by the fail safe control means is the execution of the automatic air conditioning control by the automatic air conditioning control means. Item 2. An intake door control device according to Item 1. 4. The control execution availability determination means detects presence or absence of a failure of the exhaust gas sensor, determines that suction switching control can be executed when no failure is detected, and determines that suction switching control cannot be executed when a failure is detected. 4. The intake door control device according to claim 1, wherein the intake door control device is configured to perform the following operations. 5. The control execution availability determination unit includes: a second controller configured to determine whether the outside air temperature is higher than the first predetermined temperature when the air conditioner unit is in a high load state and the outside air temperature is equal to or lower than the first predetermined temperature. When the temperature is equal to or lower than the predetermined temperature and the fan is stopped, it is determined that suction switching control cannot be executed, and otherwise, it is determined that suction switching control can be executed. An intake door control device according to claim 1, wherein