JPS61135812A - Air conditioner for vehicle - Google Patents

Abstract

PURPOSE:To keep an objective temperature even when the open air temperature is extremely down, according to a method wherein the lower limit of the quantity range of blast is changed in response to the open air temperature in a quantity of blast control type air conditioner. CONSTITUTION:A room temperature 1, an open air temperature 2, a set temperature 3, and other information 4 are inputted to a micro computer 5. At the start of heating, the difference between the temperatures 1 and 3 exceed an upper limit, so that the rapid heating is performed with predetermined large quantity of blast. The quantity of blast decrease with the rising of the room temperature, the difference between the set temperature and the detected temperature changes under a lower limit. In this case, when the open air temperature decreases to a predetermined temperature for example under -5 deg.C, the voltage is gradually increased and the quantity of blast is increased in proportion to the decrease of the open air temperature in accordance with the relation between the open air temperature and a fan motor driving voltage which are stored in a control portion 5. According to the above constitution, the room temperature can be stably kept.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a vehicle air conditioner that controls the amount of air blown within a predetermined air amount range according to the difference between a detected indoor temperature and a target indoor temperature. .

(Prior art and its problems) Conventionally, a vehicle air conditioner is known that automatically controls the amount of air blown within a predetermined air amount range depending on the detected indoor temperature and the target indoor temperature (for example, Japanese Unexamined Patent Publication No. 1983-
43816M etc.).

With this type of device, when there is a large difference between the detected indoor temperature and the target indoor temperature, such as immediately after winter heating, rapid heating is performed with a predetermined large air volume, while the interior of the vehicle is heated. As the room warms up, the air volume decreases dramatically, and if the temperature falls within a certain range relative to the target indoor temperature,
It has the advantage that it is fixed at a predetermined small air volume and does not waste power.

However, with conventional devices of this type, when the outside temperature drops extremely during the cold season, the heat dissipation effect through the window glass increases, and depending on the preset lower limit air volume value, the air near the window glass increases. There was a problem that the temperature could not be maintained at the target temperature.

(Object of the invention) The object of the invention is to provide a vehicle air conditioner of this type,
To provide a vehicle air conditioner capable of maintaining indoor temperature at a target temperature even when the outside temperature is extremely low, such as during the severe cold season.

(Structure of the Invention) The present invention will be described in detail with reference to the claim correspondence diagram in FIG.

The vehicle air conditioner 100 controls the amount of air blown within a predetermined air amount range according to the difference between the detected indoor temperature and the target indoor temperature.

In particular, the present invention is characterized in that a changing means 101 is provided for changing the lower limit of the air volume range in accordance with the outside temperature.

(Description of Embodiment) FIG. 2 is a block diagram showing the hardware configuration of an embodiment of the present invention.

In the figure, room temperature sensor 1. The outside temperature sensor 2 is each composed of a temperature sensing element such as a thermistor, and the room temperature sensor 1
The outside temperature sensor 2 is installed inside the vehicle interior, and the outside temperature sensor 2 is installed inside the front bumper, for example.

The room temperature setting device 3 is composed of a digital switch or a potentiometer, and outputs an electric signal corresponding to the target room temperature.

, other sensors 4 are comprised of various glues 1 to switches, pressure switches, etc. required for air conditioning control.

These room temperature sensors1. Outside temperature sensor 2. The outputs of the room temperature setting device 3 and other sensors 4 are taken into a microcomputer 5 that executes a system program to be described later.

The DC/DC converter 6 variably controls the output voltage of the vehicle battery 7 according to instructions from the microcomputer 5, and applies this to the fan motor 8 for blowing air.

In the fan motor 8, the torque is controlled in proportion to the applied voltage, and thereby the air volume is controlled to increase or decrease.

Further, the output of the microcomputer 5 controls a refrigeration compressor drive device 9 and a damper control device 10 that controls an air mix damper, etc., and performs well-known automatic heating and cooling control.

Next, FIG. 3 is a flowchart showing the software configuration of the embodiment of the present invention, and the operation of the present apparatus will be systematically explained below in accordance with this flowchart.

When the air conditioner is powered on, after initial processing (step 101), the set room temperature, detected air temperature, and outside temperature are read (steps 102, 103, and 1).
04>.

As is well known, in this type of vehicle air conditioner, heating mode and cooling mode are automatically selected as needed.
In the following explanation, the cooling mode will be omitted, and only the heating mode, which is closely related to the present invention, will be explained in detail (step 105).
.

Assuming that the heating has just started, in this state the difference between the set indoor temperature and the detected indoor temperature exceeds the predetermined upper limit, so in this case the air flow rate is fixed at the predetermined upper limit ( Steps 106, 107>. Therefore, in this case,
The interior of the vehicle is rapidly heated using a predetermined large weight.

When the temperature inside the vehicle gradually increases and the difference between the set temperature and the detected temperature becomes equal to or less than a predetermined upper limit (step 108), the air flow rate is proportionally controlled according to the difference between the set temperature and the detected temperature (step 108). Step 109). Therefore, in this case, as the detected indoor temperature approaches the set indoor temperature, the air flow rate gradually decreases.

Next, when the indoor temperature rises and approaches the target temperature, the difference between the set temperature and the detected temperature becomes less than the predetermined lower limit of exposure, and in this case, the process for optimizing the lower limit of air volume according to the present invention is performed. It will be done.

That is, as shown in the graph of FIG. 5, a table is set in the memory of the microcomputer that shows the relationship between the outside temperature and the fan motor drive voltage. While the drive voltage is fixed at 5.5 cm, a characteristic is set such that when the outside temperature drops below 15°C, the drive voltage gradually increases in proportion to the drop in outside temperature.

When converted into air volume, this means that when the outside temperature is 15°C or above, the airflow is fixed at a predetermined low airflow, but when the outside temperature is below -5°C, the airflow is set to increase as the outside temperature falls. (Step 110).

Next, with reference to the table shown in the graph of FIG. 5, if the driving voltage corresponding to the lower limit value of air flow is determined (Stella 1 110), the air flow rate is fixed to the lower limit value thus determined. (Step 111).

According to the above processing, as shown in Fig. 4 (A>), when the outside temperature is 15°C or higher, the lower limit of air volume decreases to 4.5■ in terms of drive voltage; As shown in FIG. 4(B), when the outside temperature is 15° C. or lower, the lower limit value of the air flow rate decreases to only 5.5 cm when converted to the drive voltage.

For this reason, when the outside temperature drops extremely, such as during the coldest season, the air flow rate is maintained at a slightly higher level, which counteracts the heat dissipation from the window glass and lowers the room temperature near the window glass. This means that it is possible to prevent this from decreasing.

(Effects of the Invention) As is clear from the description of the embodiments above, according to the present invention, in this type of vehicle air conditioner, the window The temperature inside the school can be maintained stably without increasing the heat dissipation effect from the glass, etc., and in particular, it is possible to prevent occupants near the window glass from feeling cold.

[Brief explanation of the drawing]

Fig. 1 is a diagram corresponding to claims of the present invention, Fig. 2 is a block diagram showing the hardware configuration of an embodiment of the present invention, Fig. 3 is a flowchart showing the software configuration, and Fig. 4 (A) is a diagram showing how the outside temperature is A graph showing the heating cycle in a state where the outside temperature has not dropped, Figure 4 (B) is a graph showing the heating cycle when the outside temperature has dropped extremely, and Figure 5 shows the relationship between the outside temperature and the lower limit of air volume (drive voltage conversion). It is a graph showing the relationship. 100 Vehicle air conditioner 101 Change means 1 Room temperature sensor 2 Outside temperature sensor 3 Room temperature setter 5 Microcomputer 6 - DC/DC converter 7・In-vehicle battery 8...Fun motor

Claims (1)

[Claims] (1) In a vehicle air conditioner that controls the air volume within a predetermined air volume range according to the difference between the detected indoor temperature and the target indoor temperature; The lower limit value of the air volume range is changed according to the outside temperature. A vehicle air conditioner characterized by being provided with a changing means for changing the air conditioner.