JP3317014B2 - Humidity sensor failure determination device and vehicle air conditioner - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a device for determining a failure of a humidity sensor for detecting indoor humidity and an air conditioner for controlling a dehumidifying means in accordance with the detected humidity of the humidity sensor.

[0002]

2. Description of the Related Art For example, in an automobile air conditioner,
Some air conditioners are provided with a humidity sensor for detecting the humidity in the vehicle compartment, and the air conditioning operation is controlled in accordance with the detected humidity of the humidity sensor. By controlling the humidity in the cabin within a certain range, a comfortable cabin space is provided to the occupant, or by introducing dehumidified air into the cabin when the outside air temperature is low, the humidity in the cabin is improved. Is controlled to a predetermined value or less to prevent the fogging of the window from occurring.

In this case, as the above-mentioned humidity sensor, for example, as schematically shown in FIG. 13, a humidity sensor 4 in which a polymer film 1 as a dielectric is sandwiched between a pair of electrode plates 2 and 3 is used. Is common. In this case, when the polymer film 1 absorbs moisture in the air according to the humidity, the impedance such as the resistance value or the capacitance value changes according to the degree of the absorption.
The detection output can be obtained in accordance with the humidity by electrically detecting the detection signal via the sensor.

[0004]

If the humidity sensor 4 breaks down, it becomes impossible to control the humidity in the passenger compartment. For example, if a disconnection or a short-circuit failure occurs, the humidity detected by the humidity sensor 4 may be reduced. Is 0% or 100%
Therefore, there is a problem that the air-conditioning control based on the extreme value shifts to an extreme direction.
Therefore, conventionally, the humidity detected by the humidity sensor 4 is 0%.
Alternatively, when an extreme value such as 100% is indicated, it is considered that the air conditioning control device determines that the humidity sensor 4 is out of order and stops the air conditioning control based on the humidity detected by the humidity sensor 4. .

However, in such a humidity sensor 4, unlike a general sensor, in addition to the above-described failure mode, there is a failure mode in which a detection output with respect to humidity fluctuates in a unique manner. This is because the impedance characteristics fluctuate due to dust or chemicals adhering to the side surface of the polymer film 1 constituting the humidity sensor 4,
Alternatively, the impedance characteristic fluctuates due to aging, which causes a problem that the correlation between the actual humidity and the impedance value of the humidity sensor 1 shifts.

In such a failure mode, for example, FIG.
As shown in FIG. 4, there is a tendency that the impedance characteristic with respect to the humidity becomes partially constant as shown by the broken line in the figure, compared with the impedance characteristic in the normal state shown by the solid line (high in the figure). An example is shown in which the detected humidity is constant in the humidity range). As a whole, the detected characteristics are shifted so that the detected humidity is higher, and fluctuate to 100% in the high humidity range.

In such a failure mode, the sensor output does not become a value indicating an extreme detection humidity such as 0% or 100%, so that the conventional configuration can determine the failure state. However, as a result, if air conditioning control is performed based on the detection output from the humidity sensor 4,
Due to the difference between the actual humidity and the detected humidity, there is a problem that the air conditioning control in the vehicle compartment cannot be properly performed.

The present invention has been made in view of the above circumstances, and an object of the present invention is to determine a failure mode due to aging of a humidity sensor and to cope with a failure state when the failure state is detected. It is an object of the present invention to provide a humidity sensor failure determination device and a vehicle air conditioner, which can estimate the humidity in the vehicle compartment and perform appropriate air conditioning control.

[0009]

SUMMARY OF THE INVENTION The present invention relates to a humidity sensor failure judging apparatus for detecting a humidity in a room whose humidity is controlled by the operation of the dehumidifying means. Under the condition that the operation is switched on and off, the value of the detection output of the humidity sensor from that point changes.
If there is no substantially equal value or if it exhibits a substantially equal value with a change
Characterized in was constructed by providing the determination means for determining failure of the humidity sensor based on the internal medicine.

The determination means may be configured to determine the failure of the humidity sensor by comparing the on-off switching time of the dehumidifying means and the detection output of the humidity sensor after a lapse of a predetermined time from the switching time.

It is preferable that the determination means is configured to determine a failure of the humidity sensor based on an on / off switching time at which the dehumidifying means is switched from an off state to an on state.

It is preferable that the determination means is configured to determine the failure of the humidity sensor based on an on / off switching time at which the dehumidifying means is switched from an off state to an on state. In addition, because of the humidity sensor of the present invention,
The failure determination device controls the compressor on / off to perform dehumidification.
Detects indoor humidity where humidity is controlled by the operation of the humidifier
Humidity sensor, the detection signal of this humidity sensor is
The humidity in the room shown is substantially 0 or 100%.
If the value is correct, determine the failure state and
The compressor is switched from the off state to the on state.
When the operation time of the compressor starts counting from the
The off-data is the detected humidity of the humidity sensor at that time
At the time when a predetermined time has elapsed since the start of the timing.
The detected humidity of the humidity sensor is almost equal to the off data
With control means to determine the failure state
It has features.

Further, in place of the failure determination device for a humidity sensor in the configuration described above, it may be a structure in which a failure determination device for a humidity sensor according to any one of claims 2 to 4.

[0014]

According to the first aspect of the present invention, when the operation of the dehumidifying means is switched on and off, the indoor humidity changes. Therefore, when the humidity sensor performs the normal detecting operation, the detected humidity is detected. It should also be possible to determine whether the humidity sensor is operating properly or not by detecting the indoor humidity from the detection output of the humidity sensor at that time. This makes it possible to determine a failure state in response to not only a short-circuit failure and a disconnection failure of the humidity sensor but also a characteristic change due to deterioration.

According to a second aspect of the present invention, the determination means performs a failure determination operation of the humidity sensor.
Since the failure of the humidity sensor is determined by comparing the detection output of the humidity sensor at the time of the on / off switching of the operation of the dehumidifying unit with the detection output of the humidity sensor after the lapse of the predetermined time, the on / off switching of the operation of the dehumidifying unit is performed. The failure determination operation of the humidity sensor can be reliably performed under certain conditions in accordance with the accompanying indoor humidity change.

According to the third aspect of the present invention, the determination means performs the failure determination operation of the humidity sensor.
Since the operation is performed based on the time when the operation of the dehumidifying unit is switched from the off state to the on state, the humidity sensor is placed in a humidity control environment in which the humidity in the room is controlled to decrease by starting the operation of the dehumidifying unit. Therefore, the failure determination of the humidity sensor can be performed quickly and reliably. Failure judgment of the humidity sensor according to claim 4.
According to the determination device, the determination means detects the detection signal of the humidity sensor.
The humidity indicated in the room is substantially 0 or 100%
Disconnection or short circuit when the value is equivalent to
Can determine the fault condition of the
Predetermined from when the machine is switched from off to on
The humidity detected by the humidity sensor at the time
Judge the failure state due to characteristic fluctuation when it is almost equal to the data
To determine disconnection or short-circuit failure of the humidity sensor
I can do it.

According to the fifth aspect of the present invention, when the failure state of the humidity sensor is determined by the determination means of each of the humidity sensor failure determination apparatuses described above, the air conditioning control based on the detection output of the humidity sensor. Therefore, the control means sets a predetermined humidity condition in accordance with the state set by the inside / outside air switching means at that time.

In this case, the humidity condition to be set is, for example, when the inside / outside air switching means is set to the inside air circulation mode, the dehumidifying means is operated based on the fact that fogging is expected to occur on the window glass. When the humidity value is set and the outside air introduction mode is set,
The humidity value is set so that the dehumidifying unit is not operated unnecessarily since the window glass is hardly fogged. Thus, even when the humidity sensor is out of order, it is possible to control the operation of the dehumidifying means so as to save power while at least preventing fogging of the window glass.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment in which the present invention is applied to an air conditioner for an automobile will be described below with reference to the drawings.
In FIG. 1 schematically showing the entire configuration, an air conditioner 11 is shown .
Are a duct 12 for guiding conditioned air into the vehicle interior, a blower 13 as a blowing means for introducing air into the duct 12 and blowing the air into the interior of the vehicle, a refrigeration cycle 14 as a dehumidifying means, a heater core 15 as a heating means, a determining means. And an air conditioner control device 16 having the function of control means.

The blower 13 blows air by driving a centrifugal fan 13a by a blower motor 13b, and is housed in a blower case 13c. Blower motor 13b
Is supplied with an applied voltage (blower voltage) in accordance with a control signal given from the air conditioner control device 16 via a drive circuit 17, and the rotation speed is determined by the applied voltage, thereby setting the air blowing amount of the fan 13a. Is done. The blower case 13c is formed with an inside air inlet 18 for introducing air (inside air) inside the vehicle compartment and an outside air inlet 19 for introducing air (outside air) outside the vehicle, and the inside air inlet 18 and the outside air inlet are formed. Reference numeral 19 is selectively openable / closable by an inside / outside air switching damper 20 as inside / outside air switching means in accordance with a setting state of either the inside air circulation mode or the outside air introduction mode.

The downstream end of the duct 12 includes a defroster duct 12a, a face duct 12b, and a foot duct 12c.
And each of the ducts 12a to 12a
2c is provided with a defroster outlet 21, a face outlet 22, and a foot outlet 23 provided in the vehicle interior.
It is connected to. The defroster outlet 21, face outlet 22, and foot outlet 23 can be opened and closed by outlet switching dampers 24a, 24b, 25, respectively.

In the refrigeration cycle 14, the refrigerant 2 is passed through a condenser 26, which compresses the refrigerant, sequentially through a condenser 27, a receiver 28, an expansion valve 29, and an evaporator 30 as a refrigerant circulation path.
6 is connected by a pipe 31 in a ring shape. The compressor 26 is rotatably driven from a traveling engine (not shown) via an electromagnetic clutch 32, and discharges the refrigerant as a high-temperature and high-pressure refrigerant. The electromagnetic clutch 32 is driven by a drive circuit 33 according to an on / off control signal from the air conditioner control device 16.

The condenser 27 condenses and liquefies the high-temperature and high-pressure refrigerant by blowing the cooling fan 34 and discharges it to the receiver 28. The expansion valve 29 adiabatically expands the liquid refrigerant stored in the receiver 28 and sends it to the evaporator 30. The evaporator 30 is disposed downstream of the blower 13 in the duct 12,
The air blown by the air is circulated. At this time, by performing heat exchange with the low-temperature and low-pressure refrigerant flowing into the inside, the air is cooled, and the air itself evaporates and returns to the compressor 26 again. It is designed to be inhaled.

The heater core 15 is disposed downstream of the evaporator 30 in the duct 12 and circulates cooling water for the engine therein. The cooling water is used as a heat source in the duct 12. Heat the flowing air. Note that the heater core 15 is arranged so as to occupy a part of the duct 12, and a cool air bypass 35 is provided in which air flowing in the duct 12 bypasses the heater core 15.
The amount of air flowing through the duct 12 via the evaporator 30 is adjusted by the air mix damper 36 between the air passing through the cool air bypass 35 and the air passing through the heater core 15. I have.

The air conditioner control device 16 comprises a microcomputer, a ROM, a RAM (storage means) and the like, stores an air conditioning control program, receives an operation signal from an air conditioner operation panel 37, and
Each damper (inside / outside air switching damper 20, air outlet switching damper 24a,
24b, 25, a drive circuit 17 for driving the blower motor 13b, while providing a control signal to the corresponding servo motors 38 to 40 to drive the air mix damper 36).
And outputs a control signal to the drive circuit 33 of the electromagnetic clutch 32.

The air-conditioner operation panel 37 is provided on an instrument panel (not shown) in the vehicle compartment. The air-conditioner operation panel 37 includes a temperature setter 41 for setting the room temperature and an air-conditioning control for automatically operating the air conditioner. An auto switch 42, an outlet mode switch 43 for selecting the outlets 21 to 23, and an inlet (the inside air inlet 18 or the outside air inlet 1).
An inlet mode switch 44 for selecting 9), an air volume setting switch 45 for setting the air volume of the blower 13, and the like are provided.

The various sensors include an inside air temperature sensor 46 for detecting the temperature inside the vehicle (inside air temperature Tr) and an outside air temperature sensor 4 for detecting the temperature outside the vehicle (outside air temperature Tam).
7, a solar radiation sensor 48 for detecting the amount of solar radiation (solar radiation Ts),
The temperature of the blown air immediately after passing through the evaporator 30 (temperature T
e) a post-evaporation temperature sensor 49 for detecting the temperature of the engine cooling water, a water temperature sensor 50 for detecting the temperature of the engine cooling water (cooling water temperature Tw), and a humidity sensor 51 for detecting the humidity in the vehicle interior (vehicle interior humidity RH). I have.

Next, the operation of this embodiment will be described with reference to the flowcharts of the control programs shown in FIGS.
The description will be made with reference to the explanatory diagrams shown in FIGS. In addition,
In the following description, (a) the outline of the air conditioning control will be described first, then (b) the failure determination of the humidity sensor 51 will be described, and (c) the contents of the air conditioning control corresponding to the operation state of the humidity sensor 51 Will be described.

(A) Outline of Air Conditioning Control First, the details of the air conditioning control performed by the air conditioner control device 16 will be described with reference to the flowchart of the control program shown in FIG. That is, the air conditioner control device 1
When the air conditioning control is started according to the control program shown in FIG. 2, first, initialization processing of various built-in counters, flags, and the like is performed (step S1), and subsequently, the set temperature signal Tset set by the temperature setter 41 Is read (step S2), and the detection signals T of the various sensors 46 to 51 are read.
r, Tam, Ts, Te, Tw and RH are read (step S3).

Next, when the process proceeds to step S4, the air conditioner control device 16 executes the failure determination of the humidity sensor 51 according to the failure determination program shown in FIG. 3 and stores the determination result as described later. Proceeding to step S5, the target outlet air temperature TAO is calculated according to the following equation. TAO = Kset · Tset-Kr · Tr-Kam · Tam-K
s · Ts + C (1) where Kset is a temperature setting gain, Kr is an inside air temperature gain, Kam is an outside air temperature gain, Ks is a solar radiation gain, and C is a correction constant.

Next, the air conditioner control device 16 associates the blower voltage, the inlet mode, and the outlet mode with the set conditions shown in FIGS. 5 to 7 based on the calculated target outlet air temperature TAO. (Step S
6 to S8). In this case, FIGS. 5 to 7 show the relationship between the blower voltage Ve, the inlet mode and the outlet mode with respect to the target outlet air temperature TAO, respectively, and these relationships are stored in advance as data. .

After proceeding to step S9, the air conditioner control device 16 calculates and determines the target post-evaporation temperature TEO according to the TEO (target post-evaporation temperature) determination program shown in FIG. In this case, if the humidity sensor 51 is normal, various TEOs are calculated and determined based on the detected humidity RH, and if the humidity sensor 51 is out of order, the target EVA is determined according to predetermined conditions. The temperature TEO is determined.

Thereafter, the air conditioner control device 16 uses the above-mentioned various data to control the air mix damper 3 so that the temperature of the air blown into the vehicle compartment becomes the target air temperature TAO.
6 is calculated according to the following equation (step S:
10). SW = [(TAO-Te) / (Tw-Te)] × 100
(%)… (2)

Thereafter, the air conditioner control device 16
Outputs a control signal to each of the servomotors 38 to 40 and the drive circuit 17 so as to obtain the above-mentioned various target values, and outputs the inside / outside air switching damper 20, the outlet switching dampers 24a, 24a.
b, 25, the air mix damper 36 and the blower motor 13b are controlled (step S11). Subsequently, when a predetermined control cycle τ elapses (step S1).
2), the air conditioner control device 16 returns to step S
The second and subsequent processes are repeated.

(B) Judgment of Failure of Humidity Sensor Next, the operation of judging the failure of the humidity sensor 51 will be described. When the air conditioner control device 16 starts the failure determination program shown in FIG. 3, first, in step T1, the humidity RH in the vehicle compartment indicated by the detection signal input from the humidity sensor 51 corresponds to the humidity of 0% or 100%. It is determined whether or not the compressor 26 is operating normally, and if “NO”, the process proceeds to step T2, where it is determined whether or not the compressor 26 has been switched from the off state to the on state. here,
If the determination is "NO", the failure determination program is terminated (via step T5), and the control returns to the control program.

If the determination is "YES", that is, immediately after the compressor 26 is turned on, the air conditioner control device 16 proceeds to step T3 and checks the check flag M
F is set to "1", and a count operation of a built-in timer TCon for counting the operation time of the compressor 26 is started. In the subsequent step T4, the detected humidity RH of the humidity sensor 51 at that time is stored as off-time data RHH. I do.

Next, since the check flag MF is "1" at step T5, the air conditioner control device 16 determines "YES" and shifts to step T6 where the count time TCon of the built-in timer is read. Then, it is determined whether or not the count time TCon exceeds a predetermined time α (for example, several minutes to several tens of minutes) ( step T7 ). Here, when the count time TCon has not reached the predetermined time α, the air conditioner control device 16 determines “NO”, returns to the control program, and repeats the above steps. If it is determined to be "YES", the process proceeds to step T8, where the check flag MF is set to "0" and the count value of the built-in timer TCon is cleared to "0".

Next, air conditioning control device 16, step
At T9, the detection signal Rh of the humidity sensor 51 is read, and it is determined whether or not the humidity RH at that time is substantially equal to the off-time data RHH previously stored at Step T4. That is, at this time, the humidity RH detected by the humidity sensor 51 should correspond to the indoor humidity in a state where a predetermined time has elapsed after the operation of the compressor 26 is started. If so, the value is lower than the off-time data RHH. Therefore, the air conditioner control device 16 determines “NO” here to confirm the normal state of the humidity sensor 51, and thereafter returns to the control program. I will be.

However, as described above, the humidity sensor 5
No disconnection or short-circuit failure occurred in No. 1, but the characteristics were deteriorated due to aging, adhesion of chemicals, dust, and the like, and the characteristics fluctuated as shown in FIG. 14 shown in the section of the conventional example. In such a case, even if the detection error is included, the detected humidity RH may fluctuate slightly. Accordingly, the air conditioner control device 16 determines “YES” in step T9 and shifts to step T10. Then, "1" is set to the failure flag F as a value indicating the failure state, and the program ends, and thereafter, the control program returns.

In step T1, "YE
S ”, that is, when the humidity sensor 51 has failed due to disconnection or short-circuit and the detection signal R
If the value of the detected humidity RH based on h is equal to 0% or 100%, the air conditioner control device 16 jumps to step T10, sets the value of the failure flag F to “1”, and sets the control program. To return to.

(C) Air Conditioning Control Corresponding to the Operating State of the Humidity Sensor Next, the value of the target post-evaporation temperature TEO determined in step S9 of the control program is compared with the humidity sensor 51 described above.
A description will be given corresponding to the failure determination result. In this case, the air conditioner control device 16 first determines whether or not the failure flag F has been set (F = “1”) in step P1, and if the humidity sensor 51 is operating normally and the failure flag F
Is "0", the process proceeds to the step in the case where the normal control of step P2 is performed.

That is, in step P2, the air conditioner control device 16 determines the absolute humidity RHz in the vehicle cabin based on the humidity RH data detected by the humidity sensor 51 and the inside air temperature Tr detected by the inside air temperature sensor 46. Is calculated. Next, in step P3, TEO-A, which is the target post-evaporation temperature required for air conditioning, is set in accordance with the following equation. When TAO> Tin + α, TEO-A = 100 (temporary value) When TAO ≦ Tin + α, TEO-A = TAO-β (3)

In this case, the value of Tin indicates the temperature of the intake air to the evaporator 30, which is determined by the setting state of the suction mode switch 44 and the air introduced into the duct 12 according to the setting state. The temperature is determined based on the detection signal of the inside air temperature sensor 46 or the outside air temperature sensor 47. When the intake air temperature Tin is lower than the target outlet air temperature TAO, that is, when it is not necessary to operate the refrigeration cycle 14, the target post-evaporation temperature TEO-A
Is set to a very large temporary value “100”, and when the intake air temperature Tin is equal to or higher than the target outlet air temperature TAO, as shown in FIG. 8, a value in consideration of the temperature rise β inside the air conditioner 11. It is set to. However, TE
The lower limit of the value of O-A is the frost limit temperature T1 of the evaporator 30, and the upper limit is the set temperature T2 for preventing foul odor.

Next, proceeding to step P4, the air conditioner control device 16 determines the target post-evaporation temperature TEO-B required to maintain the humidity comfort in the vehicle cabin. In this case, generally, the comfortable humidity range for humans is 20 to 60% as a relative humidity when the room temperature is 25 ° C., so that the humidity is controlled to enter this range in the air-conditioning operation state. Therefore, the value of the absolute humidity RHz as the index is calculated from the correlation shown in FIG. 9 based on the absolute humidity RHz1 and RHz2 when the relative humidity RH at room temperature of 25 ° C. is 20% and 60%. Obtain the temperature TEO-B.

Subsequently, proceeding to step P5, the air conditioner control device 16 determines the target post-evaporation temperature TEO-C necessary to prevent the fogging of the window. In this case, the fogging generated on the window glass is generally caused by the temperature of the surface of the window glass on the vehicle interior side and the absolute humidity RHz in the vehicle interior.
And the air conditioner control device 16
Can set the target post-evaporation temperature TEO-C as follows. The temperature inside the cabin of the window glass is
It depends on the setting conditions of the outside air temperature Tam, the inside air temperature Tr, the vehicle speed, the outlet mode, and the like, but here, for simplicity, it is assumed to be equal to the outside air temperature Tam. Further, since the absolute humidity RHW at which fogging occurs at the temperature of the windshield inside the vehicle can be obtained from a psychrometric chart,
The absolute humidity RHW and the absolute humidity RH in the vehicle interior at that time
It can be determined from the value of the difference from z (= RHW-RHz) whether or not fogging occurs, and the target post-evaporation temperature TEO-C is set based on the relationship shown in FIG. Become.

When three target post-evaporation temperatures TEO-A, TEO-B and TEO-C are obtained in this way,
The air conditioner control device 16 sets the one showing the smallest value among these values as the final target post-evaporation temperature TEO (step P6). That is, TEO = MIN (TEO-A, TEO-B, TEO-C) (4). Then, the air conditioner control device 16 controls the operation of the compressor 26 by turning on and off the electromagnetic clutch 32 via the drive circuit 33 as shown in FIG. 12 so as to reach the determined target post-evaporation temperature TEO. (Step P7).

Next, a case where the humidity sensor 51 has failed, that is, a case where the value of the failure flag F has been set to "1" and "YES" is determined in step P1 will be described. That is, in this case, the air conditioner control device 16 determines whether or not the internal air circulation mode is currently set in Step P8. Device 16
Determines "YES" and proceeds to step P9, in which the target post-evaporation temperature TEO-D for comfort is set to the set temperature T2 for the prevention of foul odor to correspond to a predetermined humidity value.

In the outside air mode, "N
O ”, the air conditioner control device 16
In Step P10, the target post-evaporation temperature TEO-D for comfort is set to "100" to correspond to a predetermined humidity value. And the air conditioner control device 16
When the process proceeds to step P11, the target post-evaporation temperature TEO-E for air conditioning is calculated in the same manner as in the case of calculating the above-described step P3.

Next, the air conditioner control device 16 estimates the target post-evaporation temperature TEO-F for anti-fog (step P1).
2). That is, the value of the target post-evaporation temperature TEO-F is shown in FIG.
As shown in FIG. 1, for example, when two passengers have a relative humidity of outside air of 70% and a vehicle speed of 40 km / h, a condition that no fogging occurs in the window glass is set according to the value of the outside air temperature Tam. The value is stored, and the target post-evaporation temperature TEO-F corresponding to the outside air temperature Tam at that time is read and set.

Thereafter, the air conditioner control device 16 determines the obtained target post-evaporation temperatures TEO-D, TEO-E and TEO-F.
Is set as the final target post-evaporation temperature TEO (step P).
13). That is, TEO = MIN (TEO-D, TEO-E, TEO-F) (5). Then, the air conditioner control device 16 controls the operation of the compressor 26 by turning on and off the electromagnetic clutch 32 via the drive circuit 33 as shown in FIG. 12 so as to reach the determined target post-evaporation temperature TEO. (Step P7).

Thus, even when the humidity sensor 51 fails, necessary conditions are estimated in accordance with the setting conditions such as the inside air temperature Tr, the outside air temperature Tam, and the setting state of the inside air circulation mode, and the fogging of the window is prevented. As described above, the air-conditioning control can be performed, and the safety in traveling can be improved.

According to this embodiment, the following effects can be obtained. That is, first, when the air conditioner control device 16 compares the humidity detected by the humidity sensor 51 at the time of turning on the compressor 26 with the humidity detected by the humidity sensor 51 at the time when a predetermined time has elapsed, and there is no change. Since the failure state of the humidity sensor 51 is determined, in addition to the detection of the disconnection or the short-circuit failure, it is possible to quickly and accurately detect the characteristic deterioration of the humidity sensor 51 due to aged deterioration or the like.

Second, when the failure of the humidity sensor 51 is determined by the air conditioner control device 16, a condition for operating the compressor 26 is set as a humidity condition when the internal air circulation mode is set. When the outside air introduction mode is set, a condition for stopping the compressor 26 is set as a humidity condition to control the operation of the compressor 26, so that the anti-fogging property for preventing the fogging of the vehicle window is maintained. In addition, air conditioning control with excellent power saving can be performed.

Third, the failure determination of the humidity sensor 51 is performed by the air conditioner control device 16 when the compressor 26 shifts from the OFF state to the ON state. By comparing the change in the detection output of the humidity sensor 51 under the environment, the failure state of the humidity sensor 51 can be quickly and reliably determined.

The present invention is not limited to the above embodiment, but can be modified or expanded as follows. A temperature sensor for directly detecting the intake air temperature Tin may be provided.
A notifying means for notifying the failure state of the humidity sensor when it is determined can be provided. In this case, a display means such as a lamp and a sounding means such as a buzzer disposed in the vehicle interior or the like can be used as the notifying means. The compressor 26 is stopped when the outside air temperature Tam is equal to or lower than 0 ° C. However, if dehumidification is required, a configuration may be adopted in which the defrost mode is set.

The air conditioner for a vehicle can be applied to a configuration using a reheat type heating means instead of the air mix type of this embodiment. In the case of the reheat type air conditioner, the opening degree of the flow rate control valve of the engine coolant can be adjusted by, for example, duty ratio control. The present invention is also applicable to a variable displacement refrigeration cycle using a variable displacement compressor. The present invention can also be applied to an EPR refrigeration cycle using an evaporation pressure regulating valve between an evaporator and a compressor. The invention can be applied to all air conditioners using dehumidifying means. The present invention can be applied to an air conditioner having a function of performing air conditioning control for cooling and heating.

[0057]

According to the first aspect of the present invention, the value of the detection output of the humidity sensor changes from the point of time on condition that the operation of the dehumidifying means is switched on and off. Not approximately equal or strange
Since the failure is determined based on whether the values are not substantially equal to each other due to the change in humidity, the detection output of the humidity sensor should be obtained in accordance with the indoor humidity that changes when the operation of the dehumidifying unit is switched on and off. This makes it possible to reliably determine the operation state, and has an excellent effect that the failure state can be determined in response to not only a short-circuit failure and a disconnection failure of the humidity sensor but also a characteristic change due to deterioration. .

According to the humidity sensor failure judging device according to the second aspect, the judging means performs the malfunction judging operation of the humidity sensor by detecting the output of the humidity sensor at the time of switching the operation of the dehumidifying means on and off, and elapse of a predetermined time. Since the value was compared with the detection output of the humidity sensor later,
There is an excellent effect that the failure determination operation of the humidity sensor can be reliably performed under a certain condition in response to a change in indoor humidity due to the on / off switching of the operation of the dehumidifying unit.

According to the humidity sensor failure determination device of the third aspect, the failure determination operation of the humidity sensor is performed by the determination means based on the time when the operation of the dehumidification means is switched from the off state to the on state. Therefore, the failure determination operation can be performed in a state where the humidity sensor is placed in a humidity control environment in which the humidity in the room is controlled by starting the operation of the dehumidifying means, and the humidity sensor can be quickly and reliably performed. There is an excellent effect that the failure determination of the sensor can be performed quickly and reliably. The humidity cell according to claim 4.
According to the sensor failure judging device, the judging means makes the humidity sensor
If the humidity in the room indicated by the sensor detection signal is substantially zero.
Or if the value is equivalent to 100%, there is a disconnection
Fault condition can be determined, and
The compressor switched from off to on
Humidity sensor detection at the time when a predetermined time has elapsed from the time
If the humidity is almost equal to the OFF data, it may be
By judging the fault condition, disconnection or short circuit of the humidity sensor
Failure can be determined.

According to the fifth aspect of the present invention, when the control means determines that the humidity sensor has failed, the control means sets a predetermined humidity condition in accordance with the setting state of the inside / outside air switching means. Since the dehumidifying means is configured to be controlled, the humidity condition to be set is based on, for example, that when the inside / outside air switching means is set to the inside air circulation mode, fogging is expected to occur in the window glass. Set the humidity value such that the dehumidifying unit is operated, and set the humidity value such that when the outside air introduction mode is set, the dehumidifying unit is not operated unnecessarily because there is almost no fogging of the window glass. In this way, even when the humidity sensor is out of order, the operation control of the dehumidifying unit can be performed in a manner that saves power while minimizing fogging of the window glass. Uninaru.

According to the vehicle air conditioner of the sixth aspect ,
Even if the characteristics of the humidity sensor are degraded, it is possible to reliably detect the failure state from the operating state and control the dehumidifying means in response to this, and even if the humidity sensor is malfunctioning. In addition, there is an excellent effect that the operation control of the dehumidifying means can be performed so as to save power while at least preventing the fogging of the window glass.

According to the vehicle air conditioner of the seventh aspect ,
Even when the characteristics of the humidity sensor have deteriorated, it is possible to reliably and quickly detect a failure state from the operating state and control the dehumidifying means in response thereto, and the humidity sensor has failed. Even in this case, there is an excellent effect that the operation control of the dehumidifying means can be performed so as to save power while at least preventing fogging of the window glass.

[Brief description of the drawings]

FIG. 1 is a block diagram of an overall configuration showing an embodiment of the present invention.

FIG. 2 is an air conditioning control program (part 1)

FIG. 3 is a sensor failure determination routine of an air conditioning control program (part 2).

FIG. 4 is a control routine at the time of a sensor failure in the air conditioning control program (part 3).

FIG. 5 is a diagram showing a relationship between a target blow-off air temperature TAO and a set blower voltage Ve.

FIG. 6 is a diagram showing a relationship between a target outlet air temperature TAO and an inlet mode to be set;

FIG. 7 is a diagram showing a relationship between a target outlet air temperature TAO and an outlet mode to be set;

FIG. 8 is a diagram showing a relationship between a target outlet air temperature TAO and a target post-evaporation temperature TEO-A to be set.

FIG. 9 shows a target post-evaporation temperature TEO to be set as relative humidity RH.
Diagram showing the relationship with -B

FIG. 10 is a diagram showing a relationship between a humidity difference and a target post-evaporation temperature TEO-C to be set.

FIG. 11 shows a target post-evacuation temperature T to be set as the outside air temperature Tam.
Diagram showing the relationship with EO-E

FIG. 12 is a diagram showing the relationship between the post-evaporation temperature Te and the operation of the compressor.

FIG. 13 is a configuration diagram of a humidity sensor showing a conventional example.

FIG. 14 is a diagram showing detection characteristics and deteriorated detection characteristics of a humidity sensor.

[Explanation of symbols]

11 is an air conditioner, 12 is a duct, 13 is a blower (blowing means), 14 is a refrigeration cycle, 15 is a heater core, 16 is an air conditioner control device (control means), 20 is an inside / outside air switching damper, 26 is a compressor, and 27 is a compressor. Condenser, 29 is an expansion valve, 30
Is an evaporator, 32 is an electromagnetic clutch, 34 is a cooling fan, 3
5 is a cool air bypass, 36 is an air mix damper, 37
Is an air conditioner operation panel, 46 is an inside air sensor, 47 is an outside air sensor, 48 is a solar radiation sensor, 49 is a post-evacuation sensor, 50
Is a water temperature sensor, and 51 is a humidity sensor.

──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Masafumi Kawashima 1-1-1 Showa-cho, Kariya-shi, Aichi Japan Inside Denso Co., Ltd. (56) References JP-A-59-100333 (JP, A) JP-A-55 JP-A-43690 (JP, A) JP-A-62-219110 (JP, A) JP-A-63-110018 (JP, A) JP-A-64-41753 (JP, A) JP-A-62-178415 (JP, A) JP-A-57-147907 (JP, A) JP-A-62-234713 (JP, A) JP-A-62-91306 (JP, A) Japanese Utility Model Application Sho-63-43928 (JP, U) (58) Field (Int.Cl. ⁷ , DB name) B60H 3/00 B60H 1/00 101 B60H 1/00 B60H 1/32 613 B25B 49/02 570

Claims (7)

(57) [Claims] 1. A humidity sensor for detecting the humidity in a room whose humidity is controlled by the operation of a dehumidifying means, the condition being on / off switching of the operation of the dehumidifying means.
The value of the detection output of the humidity sensor from the time does not change
It is almost the same value or changes and does not become almost the same value
Crab Based on failure determination device for a humidity sensor, characterized in that a determination means for determining failure of the humidity sensor. 2. The method according to claim 1, wherein the determination unit determines whether the humidity sensor has failed by comparing the detection output values of the humidity sensor with each other at a time when the dehumidifying unit is turned on and off and after a predetermined time has elapsed from the time when the switching is performed. The failure determination device for a humidity sensor according to claim 1. 3. The apparatus according to claim 1, wherein the determination unit is configured to determine the failure of the humidity sensor based on an on / off switching time at which the dehumidifying unit is switched from an off state to an on state. 3. The failure determination device for a humidity sensor according to 2. 4. A dehumidifier for controlling on / off of a compressor to perform dehumidification.
Detects indoor humidity where humidity is controlled by the operation of the humidifier
The humidity in the room indicated by the detection signal of the humidity sensor is substantially
When the value is equivalent to 0 or 100%
The compressor is turned off in other cases.
When the compressor is switched from the ON state to the ON state,
The operation time is started and the humidity sensor at that time is started.
The detected humidity of the sensor is stored as off data, and the timing starts.
After a predetermined time has elapsed, the humidity detected by the humidity sensor
When the degree is substantially equal to the off data, a failure state is determined.
Of a humidity sensor characterized by providing a control means
Judgment device. 5. An air blowing means for blowing air into the vehicle interior, an internal / external air switching means capable of switching air blowing by the air blowing means to either internal air circulation or external air introduction, and a humidity sensor for detecting humidity in the vehicle interior. And a dehumidifying unit for dehumidifying the interior of the vehicle based on the detection output of the humidity sensor, further comprising a failure determination device for the humidity sensor according to claim 1 , wherein the determination unit in the failure determination device for the humidity sensor comprises: An air conditioner for a vehicle, comprising: a control unit that sets a predetermined humidity condition according to a setting state of the inside / outside air switching unit and controls the dehumidifying unit when a failure of the humidity sensor is determined. . 6. An air blowing means for blowing air into the vehicle interior, an internal / external air switching means capable of switching air blowing by the air blowing means to either internal air circulation or external air introduction, and a humidity sensor for detecting humidity in the vehicle interior. And a dehumidifying means for dehumidifying the interior of the vehicle based on the detection output of the humidity sensor, and a failure determination device for the humidity sensor according to claim 2; An air conditioner for a vehicle, comprising: a control unit that sets a predetermined humidity condition according to a setting state of the inside / outside air switching unit and controls the dehumidifying unit when a failure of the humidity sensor is determined. . 7. An air blowing means for blowing air into a vehicle interior, and the air blowing means
Means ventilation is either internal air circulation or external air introduction
A switchable inside / outside air switching means, and a humidity in the vehicle interior.
The humidity sensor to be detected and the detection output of the humidity sensor
And dehumidifying means for dehumidifying the interior of the vehicle.
In both cases, a failure determination device for a humidity sensor according to claim 3 is provided.
For example, the determination means in the failure determination device for the humidity sensor
When the failure of the humidity sensor is determined,
Set a predetermined humidity condition according to the setting state of the switching means
A control unit for controlling the dehumidifying unit is provided.
Vehicle air conditioner.