JPH0550832A - Outside air temperature detecting device for automobile - Google Patents

Abstract

PURPOSE:To set an outside air temperature of good accuracy when an engine is restarted. CONSTITUTION:In a first time process after starting an engine, in the case of high engine temperature further with a sensor detection value Ta larger than a memory value Tadm (in the case of both NO of judging of steps 103, 105), correction is judged necessary. A deviation DELTATw between an engine cooling water temperature Tw and a reference value 55 deg.C is obtained (step 106) to obtain (step 107) a correction coefficient alpha in accordance with the deviation and to obtain(step 108) a deviation DELTATw between the memory value Tadm and the detection value Ta, and from these values, an adequate outside air temperature Tad is calculated (step 109) by the following formula Tad=Tadm+alphaXDELTAT. Here, the correction coefficient alpha is set to a value such that the lower is an engine temperature the larger the value is increased and the higher is the engine temperature the smaller the value is decreased.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle outside air temperature detecting device for detecting an appropriate outside air temperature by using a signal from an outside air temperature sensor installed in a place where the outside air hits.

[0002]

2. Description of the Related Art In an automobile air conditioner (automatic air conditioner), air conditioning control is performed based on outside air temperature data detected by an outside air temperature sensor. In that case, because it is necessary to accurately detect the outside temperature, install the outside temperature sensor in a place that is exposed to the outside air and is not easily affected by direct sunlight or heat such as the engine, such as a well-ventilated radiator grill or bumper. ing.

By the way, when the vehicle is stopped or restarted in a short time after the engine is stopped, the temperature around the outside air temperature sensor may be higher than the actual outside air temperature mainly due to the heat effect of the engine. The detected value of can not be used as it is as an appropriate outside air temperature. Therefore, in such a case, the data subjected to the predetermined processing is set as the outside air temperature.

Conventionally, as this type of outside air temperature detecting device,
The one described in JP-A-1-273713 is known. When the engine temperature is already above a predetermined value when the engine is started, it is considered that the outside air temperature sensor is affected by the heat of the engine or the like. Then, the intake of the signal from the outside air temperature sensor is prohibited for a predetermined time after the engine is started, and instead, the outside air temperature data before stop stored in advance is set as the outside air temperature at the present time. According to this, even if the temperature detected by the outside air temperature sensor deviates from the actual outside air temperature due to the heat influence of the engine or the like, the influence does not affect the contents of the air conditioning control.

[0005]

By the way, the heat influence of the engine on the outside air temperature sensor is naturally large as the temperature of the engine is high. Therefore, when setting the appropriate value of the outside air temperature in consideration of the heat effect of the engine, it is originally desirable to set the appropriate value in consideration of the magnitude of the heat effect in order to improve the accuracy. In this regard, in the above-mentioned conventional publication, the stored outside air temperature value at the previous stop is uniformly set as the appropriate outside air temperature at the start, regardless of the temperature of the engine. That is, the same value is set as the appropriate outside air temperature regardless of whether the engine heat effect is large or not. Therefore, accurate setting of the appropriate outside air temperature has not been performed.

Therefore, an object of the present invention is to set a proper outside air temperature with high accuracy by taking into consideration the degree of thermal influence of the engine.

[0007]

As shown in FIG. 1, an outside air temperature detecting device for a vehicle according to the present invention includes an outside air temperature sensor 1 installed at a place exposed to the outside air and outputting a detection value Ta corresponding to an ambient temperature. An outside air temperature determining means 2 for determining an appropriate outside air temperature Tad using the detected value Ta of the sensor 1 as main data, and an outside air temperature data storage means 3 for holding a stored value Tadm of the appropriate outside air temperature Tad when the engine is stopped,
The engine temperature detecting means 4 for detecting the temperature of the engine mounted in the vehicle, and the outside air temperature should be corrected when the engine temperature is higher than a predetermined value and the sensor detection value Ta is higher than the stored value Tadm when the engine is started. The correction determining means 5 that determines that there is a coefficient α that is larger when the engine temperature is lower and smaller when the engine temperature is higher (where 0 ≦ α ≦
1) the correction coefficient calculation means 6 for calculating, and the stored value Tadm
And a deviation calculation means 7 for calculating the deviation ΔT of the sensor detection value Ta. Then, the correction determination means 5
When it is determined that the correction should be made, the outside air temperature determining means 2
However, using the coefficient α calculated by the correction coefficient calculation means 6 and the deviation ΔT calculated by the deviation calculation means 7, the appropriate outside air temperature Tad is calculated and set by the following equation: Tad = Tadm + α × ΔT.

[0008]

In the apparatus of the present invention, when the engine is stopped and the vehicle is parked, the value of the outside air temperature used for air conditioning control at that time, that is, the data of the appropriate outside air temperature Tad is stored. When the engine temperature is higher than the predetermined value and the stored value Tadm stored in advance is larger than the detection value Ta of the outside air temperature sensor 1 when the engine is started next time, the engine is affected by heat. Judge that it should be corrected. On the other hand, the deviation calculating means 7 determines that the stored value Tadm
Then, the deviation ΔT of the sensor detection value Ta is calculated, and the correction coefficient calculating means 6 calculates the correction coefficient α according to the engine temperature. When it is determined that the correction should be made, the outside air temperature determining means 2 calculates and sets the appropriate outside air temperature Tad based on a predetermined formula. In this case, the set value Tad is that the higher the engine temperature is, the more the engine is affected by heat, and the reliability of the sensor detection value Ta is low. Therefore, the set value Tad is close to the stored value Tadm. Further, the lower the engine temperature is, the less the thermal influence is, and the higher the reliability of the sensor detection value is.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. FIG. 2 shows a schematic configuration of an automobile air conditioner including the outside air temperature detecting device of the embodiment. In this air conditioner, the inside air inlet 10A and the outside air inlet 10B are formed in a bifurcated manner at the most upstream portion of the air conditioning duct 10, and an intake door 11 is provided at the divided portion. By controlling the opening and closing of the intake door 11, the ratio of the inside air and the outside air to be introduced into the air conditioning duct 10 can be adjusted.

The air conditioning duct 10 is provided with a blower fan 12, an evaporator 13, an air mix door 14 and a heater 15 in order from the downstream side. The evaporator 13, together with the compressor 16, the condenser 17, the receiver tank 18, and the expansion valve 19, is pipe-connected to form a refrigeration cycle. The compressor 16 is driven by the force transmitted from the engine, and its drive is controlled by connecting and disconnecting the electromagnetic clutch.

The air mix door 14 is
The ratio of the air passing through the heater 15 and the air not passing through the heater 15 is adjusted. Then, the air that has passed through the heater 15 and the air that does not pass through the heater 15 are mixed on the downstream side of the heater 15 so that the temperature of the air is adjusted and the air is blown into the vehicle from the air outlet.

The rear end of the air conditioning duct 10 is divided into a defrost outlet 21, a vent outlet 22, and a heat outlet 23 and opens into the vehicle compartment.
Mode doors 24, 25, and 26 are provided at 23, respectively. And these mode doors 24, 25, 26
The blowing mode can be changed by selectively opening and closing.

The vent outlet 22 is further divided into left and right vent outlets 22R and 22L. Then, by opening and closing the air distribution door 27, it is possible to adjust the air distribution balance from the left and right vent outlets 22R and 22L.

The intake door 11, the air mix door 14, the mode doors 24 to 26, and the air distribution door 27 described above are controlled to open and close by actuators 30, 31, 32, and 33, respectively. These actuators 30, 31, 3
2, 33, the blower fan 12, and the compressor 16
Are controlled by the control unit 50.

The control unit 50 includes a drive circuit for driving the actuator, the blower fan, etc., a microcomputer for supplying a control signal to each drive circuit, an A / D converter connected to the microcomputer, and a multiplexer. It includes. As is well known, the microcomputer includes a CPU, a ROM, a battery backed up RAM, a timer, and the like, and at least the outside air temperature determination means 2, the outside air temperature data storage means 4, and the correction determination means 5 shown in FIG. The functions of the correction coefficient calculation means 6 and the deviation calculation means 7 are fulfilled.

In the A / D converter in the control unit 50, a potentiometer 51 for detecting the opening degree of the air mix door 14, a solar radiation sensor 52 for detecting the amount of solar radiation entering the passenger compartment, and an outside air temperature are detected. An outside air temperature sensor 53, an in-vehicle temperature sensor 54 for detecting a representative temperature in the vehicle compartment, a temperature setter 55 for setting a temperature in the vehicle compartment, a water temperature sensor 56 for detecting a cooling water temperature of the engine, an ignition switch 57, etc. are connected. There is. The outside air temperature sensor 53 in this case is attached to the front grill in front of the engine room as in the conventional case.

Further, the control unit 50 is connected to an operation panel 60 for issuing an operation command of the device. The operation panel 60 has, in addition to switches for issuing various operation commands, a display unit 61 that normally displays the in-vehicle set temperature and, if necessary, the outside air set temperature and the like.

Next, an example of control operation of the microcomputer in the control unit 50 will be described.
Since only the routine for detecting the outside air temperature is different from the conventional control here, only that routine will be described and the other description will be omitted. FIG. 3 shows a routine for detecting the outside air temperature. The processing of this routine is repeatedly performed at regular intervals (for example, 1 sec).

When this process starts, first, at step 101, the ignition switch is turned on, and then it is determined whether or not it is the first process. If it is the first processing (YES in step 101), the delay timer described later is cleared in step 102, and the process proceeds to step 103. Then, it is determined here whether the water temperature Tw of the engine cooling water detected by the water temperature sensor 56 is lower than 55 ° C. The value of 55 ° C. in this case is a value that is a standard for determining whether or not the engine temperature is high, and any value that is a standard may be changed to another value.

If the water temperature Tw is low (YES) as a result of the determination in step 103, the vehicle has been stopped for a long time, and the outside air temperature sensor 53 outputs a value corresponding to the actual outside air temperature. Therefore, the routine proceeds to step 104, where the detected value Ta of the outside air temperature sensor 53 is set as it is as the appropriate outside air temperature Tad.

Even when the water temperature Tw is 55 ° C. or higher (NO at step 103), if the sensor detection value Ta is smaller than the stored value Tadm of the outside air temperature data when the vehicle was stopped last time (step 105). If the determination is YES), it is considered that the outside air temperature sensor 53 is not affected by the heat of the engine, and the process proceeds to step 104.

On the other hand, when the water temperature Tw is high and the detected value Ta of the outside air temperature sensor is larger than the stored value Tadm, both determinations at steps 103 and 105 are NO.
This determination is a determination that the outside air temperature sensor 53 is affected by the heat of the engine and the sensor detection value Ta cannot be used as it is, so that the correction should be performed.
If this determination is made, the process proceeds to step 106. Then, in step 106, the current water temperature Tw and the reference value (55
C.) deviation ΔTw is calculated. In other words, how high is the water temperature above the standard? Next, at step 107, the correction coefficient α is calculated according to the magnitude of the deviation ΔTw. That is, in this case, the smaller the deviation ΔTw (in other words, the lower the engine temperature) is, the larger the coefficient α is, and the deviation ΔTw is increased.
Is larger (in other words, the higher the engine temperature is)
Reduce the coefficient α. However, 0 ≦ α ≦ 1. next,
In step 108, a deviation ΔT between the stored value Tadm of the outside air temperature data and the outside air temperature sensor detection value Ta is obtained.

Then, the routine proceeds to step 109, where the proper outside air temperature Tad is calculated and set based on the following expression Tad = Tadm + α × ΔT. As described above, when the outside air temperature sensor is affected by the heat of the engine, in the first process after the ignition switch is turned on, the appropriate outside air temperature Ta corresponding to the degree of the heat influence of the engine is obtained.
Since d is set, accurate setting is achieved.

If it is not the first processing, that is, the processing after the ignition switch is turned on for the second time and thereafter, the judgment in step 101 becomes NO and the routine proceeds to step 110. Then, it is checked here whether the water temperature Tw is lower than 55 ° C., and if the water temperature Tw is low (if the determination in step 110 is YES), the detection value Ta of the outside air temperature sensor 53 is directly set in step 111. Set as temperature Tad. Further, when the water temperature Tw is high (when the determination in step 110 is NO), the routine proceeds to step 112, where the previously set appropriate outside air temperature Ta is set.
It is determined whether the sensor detection value Ta is smaller than d. When the sensor detection value Ta becomes smaller than the appropriate outside air temperature Tad, this determination becomes YES, the routine proceeds to step 113, the delay timer is cleared, and the routine proceeds to step 111.

If the sensor detection value Ta is still higher than the previously set appropriate outside air temperature Tad (NO at step 112), the delay timer is counted up at step 114. When the timer count value is within 45 seconds, the determination at step 115 becomes NO, and when it exceeds 45 seconds, the determination becomes YES and the routine proceeds to step 116 where the delay timer is cleared and the appropriate outside air temperature Tad is set to 0. Raise by 3 ℃. In this way, while the water temperature Tw is high and the sensor detection value Ta is higher than the previously set appropriate outside air temperature Tad, 45
The value of the appropriate outside air temperature Tad is increased by 0.3 ° C. every second, and the appropriate outside air temperature Tad is gradually increased to the sensor detection value Ta. Also in this case, the time of 45 seconds and the raising amount of 0.3 ° C. may be slightly changed.

In any case, in step 118, which is the final step of one process, the appropriate outside air temperature Tad is updated and stored as a new storage value Tadm, and the process ends. This stored value is retained even when the engine is stopped. In addition, the proper outside air temperature Tad determined by one processing
Is displayed on the display unit 61 of the operation panel 60 as required by the occupant.

According to the above-mentioned processing, a value according to the degree of heat influence of the engine is set as the proper outside air temperature in the first processing after the ignition switch is turned on. Therefore, the setting with high accuracy is performed, and comfortable air conditioning control suitable for the actual situation without any discomfort is performed.

In the above embodiment, the water temperature sensor 56 for detecting the engine cooling water temperature is used as the means for detecting the engine temperature, but the sensor for detecting the temperature of the cylinder head may be replaced with this. .. Further, in the above embodiment, the detected outside air temperature is used for air conditioning control, but it may be used for other purposes.

[0029]

As described above, according to the present invention,
When the engine is restarted, a highly accurate outside air temperature is set in consideration of the heat effect of the engine. Therefore, it is possible to perform the air-conditioning control according to the actual situation.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of an automobile outside air temperature detection device of the present invention.

FIG. 2 is a block diagram showing the configuration of an automobile air conditioner including an embodiment of the present invention.

FIG. 3 is a view showing a flowchart of an outside air temperature detection process of the same embodiment.

[Explanation of Codes] 1 ... Outside air temperature sensor 2 ... Outside air temperature determining means 3 ... Outside air temperature data storing means 4 ... Engine temperature detecting means 5 ... Correction determining means 6 ... Correction coefficient calculating means 7 ... Deviation calculating means 50 ... Control unit 53 ... Outside air temperature sensor 56 ... Water temperature sensor (engine temperature detecting means) 57 ... Ignition switch

Claims (1)

[Claims] 1. An (a) an outside air temperature sensor which is installed in a place exposed to the outside air and outputs a detection value Ta corresponding to an ambient temperature, and (b) an appropriate outside air temperature Tad using the detection value Ta of the sensor as main data. Means for determining the outside air temperature, and (c) the appropriate outside air temperature Tad when the engine is stopped.
The outside air temperature data storage means for holding the stored value Tadm of (3), (d) engine temperature detection means for detecting the temperature of the engine mounted on the vehicle, and (e) when the engine is started, the engine temperature is higher than a predetermined value, Further, when the sensor detection value Ta is higher than the stored value Tadm, correction determining means for determining that the outside air temperature should be corrected, and (f) a coefficient α that is larger as the engine temperature is lower and smaller as the engine temperature is higher. (However, 0 ≦ α ≦ 1), and (g) a deviation Δ between the above-mentioned stored value Tadm and the sensor detection value Ta.
And a means for calculating T, wherein the outside air temperature determining means determines the coefficient α calculated by the correction coefficient calculating means and the deviation calculated by the deviation calculating means when the correction determining means determines that the correction should be performed. An outside air temperature detecting device for a vehicle, which uses ΔT to calculate and set an appropriate outside air temperature Tad by the following equation: Tad = Tadm + α × ΔT.