JPS62244713A - Air conditioner for automobile - Google Patents

Abstract

PURPOSE:To aim at improvement in cooling efficiency, by constituting an air conditioner so as to prohibit the closure of an outside air inlet at a time when the outside air is less than the specified value with maximum cool and a refrigerant compressor is turned on, in case of the inside air circulating quantity-outside air intake quantity automatic control type air conditioner. CONSTITUTION:A max-cool setting signal is inputted into a controlling device 400 from a max-cool setting device 100, and an operating mode from a compressor operating mode judging device 200, respectively. On the other hand, outside temperature to be detected by an outside air sensor 29 is inputted into an outside temperature judging device 300, and if it is less than the specified value, a judging signal is inputted into a controller 400 outputs a signal prohibiting the closure of an outside air inlet 3 to an inside-outside air adjusting device 500 when a compressor is operated and of a max-cool mode and that the outside temperature is less than the specified value. With this constitution, even at time of the max-cool mode, the outside air is utilized for cooling, thus cooling efficiency is improved.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an air conditioner for an automobile, and particularly to an air conditioner for an automobile of a type that automatically controls the amount of internal air circulation or the amount of outside air introduced.

(Prior Art) It is well known that outside air is used for cooling in automotive air conditioners. For example, in Japanese Patent Application Laid-Open No. 56-31809, the outside air temperature is detected, and when the detected outside air temperature is below a predetermined temperature, the outside air switching door of the air conditioning duct is moved to introduce 100x of outside air, improving cooling efficiency. It is disclosed to reduce the heat load on the evaporator and reduce the operating rate of the compressor.

(Problem to be solved by the invention) However, in the past, when the temperature setting is set to max cool, if the compressor operation mode is on, the internal air circulation mode is set regardless of the outside air temperature. Therefore, even when the outside air temperature is low, the inside air Wl ring is forced, resulting in a problem that the cooling efficiency decreases.

Therefore, this invention solves the above-mentioned conventional problems, and
An object of the present invention is to provide an air conditioner for an automobile that can perform cooling using outside air even during maximum cooling, thereby increasing cooling efficiency.

(Means for Solving the Problems) The gist of the present invention is, as shown in FIG. an evaporator 6 disposed in the air conditioning duct 1, a refrigeration cycle 36 including a compressor 7 for compressing the refrigerant evaporated by the evaporator 6, and a Mac configured to operate the compressor 7 at maximum. School setting means 100,
A compressor operation mode determining means 200 that determines whether the compressor 7 is in an on mode, an outside air sensor 29 that detects the temperature of outside air, and whether the outside air temperature detected by this outside air sensor 29 is equal to or higher than a predetermined value. an outside air temperature determining means 300 for determining whether or not the outside air temperature is present; and an outside air adjusting means 500 for adjusting the opening degree between the outside air population 2 and the inside air population 3.
and the outside air adjustment means 500 according to the determination results of the max cool setting means 100, the compressor operation mode determination means 200, and the outside air temperature determination means 300.
control means 400 for controlling the amount of adjustment of , and outputs a control signal to the outside air adjustment means 500 to prevent the outside air population 3 from closing when the outside air temperature determination means 300 determines that the outside air temperature is below a first predetermined value. It's what I did.

(Function) Therefore, when the compressor 7 is set to max cool by the max cool setting means 100 when the compressor 7 is in the ON mode, the outside air temperature detected by the outside air sensor 29 is determined to be below the first predetermined temperature by the outside air temperature determining means 300. If it is determined that there is an outside air population 3, the control means 400
A control signal to prevent the air conditioning duct from closing is output, and the inside/outside air adjustment means 500 receives this and opens the outside air population 3 even slightly, so that low-temperature outside air is introduced into the air conditioning duct 1. , it is possible to achieve the above problems.

(Example) In Fig. 2, the air conditioner for an automobile is formed in such a way that an inside air population 2 and an outside air population 3 are divided into two parts on the most upstream side of an air conditioning duct 1, and an inside/outside air switching door is provided in the divided part. 4 is provided, and the opening degree of the inside/outside air switching door 4 changes continuously to adjust the ratio of inside air and outside air to be introduced into the air conditioning duct 1.

The blower 5 is for sucking air into the air conditioning duct 1 and blowing it to the downstream side, and an evaporator 6 is provided on the downstream side of the blower 5.

The evaporator 6 is connected with piping together with a compressor 7, a condenser, a receiver tank 9, an expansion valve 10, and a pressure control valve 11 to form a refrigeration cycle 36. The compressor 7 has an electromagnetic clutch 13 for connecting and connecting the driving force transmitted from the engine 12. The pressure control valve 11 controls the evaporation pressure of the evaporator 6 so that the temperature of the evaporator 6 does not drop below the freezing temperature even when the compressor 7 is continuously operated.

An air mix door 14 is provided on the downstream side of the evaporator 6.
and the heater core 15 are arranged, and the air mix door 14
The ratio of air sent to the heater core 15 and air bypassing the heater core 15 is adjusted according to the opening degree of the heater core 15 . The air that has passed through the heater core 15 and the bypassed air are later mixed and their temperature is adjusted.

The rear end of the air conditioning duct 1 is divided into a defrost outlet 16, a vent outlet 17, and a heat outlet 18, which open into the vehicle interior 19, and mode doors 20a, 20b are installed in the separated parts.
are provided, and the blowing mode can be changed by selectively opening and closing the mode doors 20a and 2Qb.

The above-mentioned internal/external air switching door 4, air mix door 14, and mode doors 20a, 20b are operated by actuators 21a to 21c, respectively, and the actuators 21a to 21c are connected to the microcomputer 23 via drive ports u22a to 22c. is controlled based on the output signal of. Further, the rotation speed of the blower 5 and the on/off of the electromagnetic clutch 13 are similarly controlled by the drive circuits 22d and 22, respectively.
It is controlled based on the output signal from the microcomputer 23 via e. Note that the inside/outside air switching door 4, the actuator 21a, and the drive circuit 22a constitute the inside/outside air adjusting means 500 shown in FIG.

The microcomputer 23 includes central processing units CPU, l.
Output-only memory ROM, random access memo + JR
, AM, and a clock generator that generates reference pulses with a crystal oscillator 24. An AD converter 25 is connected to the microcomputer 23. This A-D converter 25 includes an in-vehicle sensor 2G that detects the temperature inside the vehicle interior 19, an opening sensor 27 that detects the opening degree of the air mix door 14 (the detected opening degree is θ),
A solar radiation sensor 28 that detects the amount of solar radiation entering the cabin 19, an outside air sensor 29 that detects the outside air temperature (the detected temperature is Ll), a mode sensor 30 that detects the temperature of the evaporator 6, and a temperature inside the cabin 19. A temperature setting device 31 for setting the temperature and a fan voltage detection circuit 32 for detecting the terminal voltage of the blower 5 described above are connected, and the analog signals input from these are converted into digital signals and sent to the microcomputer 23.
send to By setting the knob at one end of the temperature setting device 31, it is possible to specify a maximum cooling mode for operating the compressor at its maximum, and this temperature setting device 31
Thus, the maximum cool setting means 100 shown in FIG. 1 is configured. The microcomputer 23 includes a blower 5.
Signals are input from a fan switch 33 that commands the rotation speed of the compressor, an A/C switch 34 that commands the operating mode of the compressor, and an inside/outside air auto switch 35 that commands whether or not to automatically control the introduction of inside and outside air. . Based on these input signals, the microcomputer 23 calculates control signals to be output to the aforementioned drive circuits 223 to 22e.

Note that the max cool setting means 100 may be constructed from a temperature setting device having an up/down switch and a digital display, or the max cool switch may be provided separately from the temperature setting device. .

Next, an example of the control operation of the microcomputer 23 will be explained, but since the control of the blower 5, compressor 7, air mix door 14, and mode doors 20a, 20b is the same as in the conventional case, the explanation will be omitted, and the control of the inside/outside air switching door 4 will be omitted. Only this will be explained below.

In FIG. 3, in the control of the inside and outside air, first, in step 50, it is determined whether or not the command for controlling the inside and outside air is set to auto based on the output from the inside and outside air auto switch 35. If it is not set to auto, the process proceeds to step 61, where the internal and external air is controlled manually. on the other hand,
If it is determined to be automatic, the process advances to the next step 51.

In this step 51, it is determined whether the fan switch 33 is off based on the output from the fan switch 33 mentioned above. If it is determined that the fan switch 33 is off, the process proceeds to step 60, where the outside air is introduced at 100%. On the other hand, if the fan switch 33 is on, the process advances to step 52.

In this step 52, it is determined whether or not the operating mode of the compressor 7 is on based on the output from the A/C switch 34 mentioned above. If it is determined that the compressor 7 is not in the on mode, the process proceeds to step 60, where the outside air is introduced at 100%.

On the other hand, if it is determined that the compressor 7 is not in the on mode, the process proceeds to step 53. Note that the process of step 52 constitutes the compressor operation mode determining means 200 shown in FIG.

In step 53, it is determined based on the output from the temperature setting device 31 mentioned above whether or not the maximum cool is commanded. If it is determined that it is the maximum school, the process advances to step 54.

In this step 54, the above-mentioned outside air sensor 29
It is determined whether the outside air temperature t detected at is lower than a first predetermined value α. 1. If <α, the process proceeds to step 60, and outside air is introduced at 100%. As a result, even when the maximum cooling setting is set, if the outside air is low, the cooling efficiency can be improved by introducing outside air. On the other hand, in step 54, 1. If it is determined that <α is not the case, cooling can no longer be achieved by introducing outside air, so the process proceeds to step 58, where the inside air circulation is set at 100%. In this step 54, 1. If it is determined that <α, the process may proceed to step 59, and the outside air may be partially introduced instead of all.

The process when it is determined in step 53 that it is not Max Cool is, for example, according to Japanese Patent Application Laid-Open No. 60-8501.
This is similar to the conventional example shown in Publication No. 2.

That is, first in step 55, it is determined whether the outside air temperature t detected by the outside air sensor 29 is lower than the second predetermined value β. This second predetermined value β is set to α<β. This is because the blowing temperature may be higher than during maximum cooling. In this step 55,
1. If it is determined that <β, the process proceeds to step 60, where the outside air is introduced at 100%, and 1. If it is determined that it is not <β, the process proceeds to step 56. In this step 56, it is determined whether the opening degree θ of the air mix door 14 detected by the aforementioned potentiometer 27 is smaller than a predetermined value θ (for example, 10%) and the passage to the heater core 15 is closed. . If θ<θ1, the evaporator 6 has surplus capacity, so the process proceeds to step 59, and a mix mode is set in which, for example, 30% of outside air is introduced. On the other hand, if it is determined that e<e, the process proceeds to step 57, and the fan voltage detected by the aforementioned fan voltage detection circuit is set to a predetermined value ■1.
(In other words, whether the rotational speed of the blower 5 is larger than, for example, middle low) is determined. Blower 5
If the rotation speed is high, rapid cooling is required, so in that case, proceed to step 58 and set the internal air circulation to 100%.
If not, the process advances to step 59 and the mix mode is set.

Note that the outside air temperature determination means 300 shown in FIG. 1 is configured by the processing in steps 54 and 55, and the steps 58 and
59. The control means 400 shown in FIG.
is configured.

(Effects of the Invention) As described above, according to the present invention, even during maximum cooling, if the outside air temperature is lower than a predetermined value, outside air is introduced, so cooling efficiency can be improved. . Furthermore, even if the compressor is rendered inoperable by an external switch, such as a low pressure switch, outside air is introduced during maximum cooling, so the minimum cooling capacity can be ensured.

[Brief explanation of drawings]

Fig. 1 is a block diagram showing the configuration of the present invention, Fig. 2 is a block diagram showing an automotive air conditioner according to an embodiment of the invention, and Fig. 3 is a flowchart showing the internal/external air control routine of the microcomputer used in the above. It is. l... Air conditioning duct, 6... Evaporator, 7...
Compressor, 16 to 18... Air outlet, 19... Vehicle interior, 36... Refrigeration cycle, 100... Max cool setting means, 200... Compressor operation mode determining means, 300... Outside air temperature Judgment means, 400...
Control means, 500...Internal and external air adjustment means.

Claims (3)

[Claims] 1. An air conditioning duct having an inside air inlet, an outside air inlet, and a blowout opening opening into a vehicle compartment; a refrigeration cycle including an evaporator disposed in the air conditioning duct; and a compressor for compressing refrigerant evaporated by the evaporator; a compressor operation mode determining means for determining whether the compressor is in an on mode; an outside air sensor for detecting the temperature of outside air; and an outside air sensor for detecting the outside air temperature. an outside air temperature determining means for determining whether the temperature is above a predetermined value; an outside air adjusting means for adjusting the opening degree of the outside air inlet and the inside air inlet; the mask cool setting means; and the compressor operation mode determining means. and a control means for controlling the amount of adjustment of the inside and outside air adjusting means according to the determination result of the outside air temperature determining means, and the control means is configured to set a mask school by the mask school setting means and to control the compressor operation. A control signal for preventing the outside air inlet from closing when the mode determining means determines that the compressor is in the on mode and the outside air temperature determining means determines that the outside air temperature is below a first predetermined value. An air conditioner for an automobile, characterized in that the air conditioner outputs the air to the inside/outside air conditioning means. 2. The control means is configured such that the mask school setting means sets the compressor to a mask cool, the compressor operation mode determining means determines that the compressor is in the on mode, and the outside air temperature determining means determines that the outside air temperature is equal to or lower than a first predetermined value. The automotive air conditioner according to claim 1, wherein when it is determined that the air conditioner is present, a control signal is output to the inside/outside air adjusting means to completely close the inside air inlet and completely open the outside air inlet. Device. 3. The control means is set to a state other than the mask school by the mask school setting means, the compressor is determined to be in the on mode by the compressor operation mode determination means, and the outside air temperature is determined to be lower than the first predetermined value by the outside air temperature determination means. If it is determined that the inside air inlet is equal to or lower than a second predetermined high value, a control signal is output to the outside air adjusting means to completely close the inside air inlet and completely open the outside air inlet. An air conditioner for an automobile according to item 1 or 2.