JPS6233085B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a device for air conditioning a vehicle interior, and more particularly to a vehicle air conditioner with improved fuel efficiency.

In recent years, various devices,
A mechanism etc. is installed or adopted in a vehicle. Among these, the following control method has been adopted in vehicle air conditioners as an aid to achieving the above-mentioned objective. That is, when the outside air temperature is lower than the required air temperature to be blown into the vehicle interior by a predetermined temperature or more during cooling, the vehicle interior is cooled by outside air without driving the compressor. Specifically, the configuration is as shown in FIG. In the same figure, 1 is the intake door, 3
is a blower fan, 5 is an evaporator, 7 is a temperature sensor that detects the temperature of the air passing through the evaporator, 9 is a heater core, 11 is an air mix door, 13 is a differential door, 15 is a vent door, 17 is a floor door, 19 is an inside temperature sensor, 21 is a For example, as shown in FIG. 2, an outside temperature sensor is installed on a front bumper 22 of the vehicle body, 23 is a control unit, 25 is a balance control for setting the interior temperature of the vehicle, and 26 is a solar radiation sensor.

When controlling the temperature in the vehicle interior with such a configuration, the control unit 23 controls the set temperature set by the balance control 25, the vehicle interior temperature detected by the interior temperature sensor 19, and the temperature detected by the outside temperature sensor 21. The required temperature of the air to be blown into the vehicle interior (hereinafter referred to as ``outlet temperature'') is calculated based on the outside air temperature and the amount of solar radiation detected by the solar radiation sensor 26, and the air that has passed through the evaporator 5 is calculated first. The opening degree of the air mix door 11 is controlled based on the temperature detected by the temperature sensor 7 in order to set the temperature at which the air is blown into the vehicle interior. Particularly when cooling the vehicle interior, the control unit 23 controls the intake lever (not shown).
is the outside air introduction side (FRESH), and when the outside air temperature detected by the outside air temperature sensor 21 is lower than the outlet temperature by a predetermined temperature or more, a compressor (not shown) is activated to cool the passenger compartment with outside air. No driving will be performed.

Therefore, the vehicle air conditioner configured as described above can perform accurate temperature control and at the same time contribute to fuel-efficient driving. However, when deciding not to drive the compressor for fuel-saving driving as mentioned above, the temperature detected by the outside air temperature sensor installed in the front bumper is used for this judgment, but this is not an appropriate place to detect outside air temperature. , when outside air is taken into the vehicle,
During the journey to the evaporator, there is a possibility that the temperature becomes higher than the detected temperature due to the influence of heat such as engine temperature. Therefore, there is a possibility that the inside of the vehicle cannot be reliably cooled by the outside air taken in, and as a result, appropriate fuel-saving operation may not be achieved. In addition, since the temperature detected by the outside air temperature sensor is used for the above judgment, this judgment cannot be made when the inside air is being circulated, so the above-mentioned cooling effect for fuel-saving operation can only be performed when outside air is introduced. It is not possible to improve the efficiency of fuel-efficient driving.

This invention has been made in view of the above, and in order to improve fuel efficiency, the external conditions necessary for the temperature of the air circulated immediately before the air intake side of the evaporator or the air introduced from outside to reach the set temperature in the passenger compartment. The compressor is not driven when the evaporator outlet temperature is lower than the evaporator outlet temperature required by.

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

FIG. 3 shows an embodiment of the present invention, the feature of which is that a temperature sensor 27 is provided just before the air suction side of the evaporator 5, so that the air temperature immediately before the suction side enters the passenger compartment during cooling of the passenger compartment. When the temperature is lower than the blowout temperature, the air passing through the evaporator 5 is used to cool the interior of the vehicle without driving the compressor 28 regardless of the position of the intake door 1. Note that the same reference numerals as in FIGS. 1 and 2 indicate the same components.

As shown in FIG. 4, the control unit 23' controls the airflow into the vehicle interior using a predetermined calculation formula based on the output signals of the inside temperature sensor 19, outside temperature sensor 21, balance control 25, temperature sensor 27, and solar radiation sensor 26. an arithmetic circuit 29 that calculates the temperature;
A comparison control circuit 31 is provided which compares the blowout temperature with the temperature detected by the temperature sensor 27 and does not drive the compressor 28 when it is detected that the blowout temperature is higher.

Note that the inside temperature sensor 19, outside temperature sensor 21, and temperature sensor 27 used in the embodiment shown in FIG. 3 are sensors with negative characteristics as shown in FIG.

Next, the operation of this embodiment will be explained using A to C of FIG. 6. FIG. 6A is a characteristic diagram showing changes in the temperature detected by the temperature sensor 27 (solid line) and the outlet temperature calculated by the arithmetic circuit 29 (broken line) with respect to time, and FIG. 6B is the output of the temperature sensor 27 with respect to time. Characteristic diagram showing changes in voltage (solid line) and output voltage (broken line) of the arithmetic circuit 29, FIG. 6C
2 is a diagram illustrating an example of the on/off operation of the compressor 28 with respect to time.

The temperature control function inside the vehicle is almost the same as the conventional one, and the opening degree control of the air mix door 11 is performed based on the calculation result of the air temperature passing through the evaporator 5 from the detected temperature output of the temperature sensor 27 by the control unit 23'. However, the temperature control performance is at the same level as the conventional method.

When cooling the vehicle interior, the control unit 23' calculates the air outlet temperature, detects that the temperature of the air that has been circulated or introduced from the outside just before the air suction side of the evaporator 5 is lower than the air outlet temperature, and then controls the compressor 28. The low-temperature air passing through the evaporator 5 provides an appropriate cooling effect without being driven (see A to C in FIG. 6).

As explained above, according to the present invention, the air temperature immediately before the air suction side of the evaporator is determined by the external conditions necessary to maintain the set temperature in the passenger compartment, regardless of whether the inside air is being circulated or the outside air is being introduced. When the evaporator outlet air temperature is lower than the
Since the compressor is not driven and the interior of the vehicle is cooled with the low-temperature air, it is possible to perform accurate fuel-saving driving and improve fuel-saving driving efficiency.

[Brief explanation of the drawing]

Figures 1 and 2 are conventional examples of vehicle air conditioners, Figure 3 is an embodiment of the present invention, Figure 4 is an explanatory diagram of the configuration of the control unit, and Figure 5 is the characteristics of the temperature sensor used in the embodiment. Figures A to C in Figure 6
is an explanatory diagram of the action of FIG. 3. (Explanation of symbols representing main parts of drawings), 5
... Evaporator, 27... Temperature sensor, 28... Compressor, 31... Comparison control circuit.

Claims (1)

[Claims] 1 In a device for air-conditioning a vehicle interior, a means is provided immediately before the air suction side of the evaporator to detect the temperature of the circulated inside air or the air introduced from the outside immediately before the suction side, and a means for detecting the temperature of the air that is circulated inside the air or introduced from outside, and that the detected temperature sets the temperature of the vehicle interior during cooling. 1. A vehicle air conditioner comprising means for not driving a compressor when the evaporator outlet air temperature is lower than the temperature of the evaporator outlet air required by external conditions.