JPS62255213A - Airconditioning device for automobile - Google Patents

Abstract

PURPOSE:To prevent the excessive cooling of a cabin and ensure comfortability under an airconditioning condition by raising compressor capacity within a range of allowable maximum capacity corresponding to cabin temperature when the window glass of an automobile has been frosted with humidity. CONSTITUTION:An airconditioning device has a cooling cycle comprising an evaporator 3 in an airconditioning duct 1 and a variable capacity type compressor 5. In this case, there are provided a frost judgement means 100 for making judgement as to whether window glass has been frosted with humidity and a temperature data generation means 200 for generating the data of temperature in a cabin 15. And depending upon output from said means 200, the allowable maximum capacity of the compressor 5 is set by a maximum capacity setting means 300. And when the occurrence of frost has been judged by the frost judgement means 100, a compressor control means 400 is made to control the capacity of the compressor 5 for a capacity increase until the frost of the window glass 16 is cleared within a range established with the maximum capacity setting means 300.

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 equipped with a variable capacity compressor.

(Prior Art) In this type of automobile air conditioner, it is known, for example, from Japanese Utility Model Application Laid-open No. 59-92013, to control the capacity of a compressor depending on the fogging of the automobile window glass. This system not only drives the compressor when the car's window glass becomes foggy, but also increases the capacity of the compressor in stages until the fog clears, and uses the evaporator to perform the necessary and sufficient dehumidification, thereby saving power and saving energy. This is to save energy.

(Problems to be Solved by the Invention) However, in the conventional example described above, the capacity of the compressor increases indefinitely unless the window glass becomes foggy. Therefore, for example, even if the temperature inside the vehicle is very low, the compressor is driven at maximum capacity, and even if the air mix door is set to the full heat position, the temperature inside the vehicle cannot be increased significantly. There is a problem in that the temperature control inside the vehicle may be sacrificed.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide an air conditioner for an automobile that can solve the above-mentioned conventional problems and can automatically and efficiently clear the fog on the window glass without neglecting to control the temperature inside the vehicle. It is said that

(Means for Solving the Problems) As shown in FIG. A refrigeration cycle 9 including a disposed evaporator 3 and a variable capacity compressor 5 that compresses the refrigerant evaporated by the evaporator 3, and a fogging process for determining whether fogging has occurred on the window glass 16 constituting the vehicle interior 15. determination means 100; temperature data generation means 200 for generating data regarding the temperature inside the vehicle compartment 15;
maximum capacity setting means 300 for setting the allowable maximum capacity of the compressor 5 according to the output of the temperature data generation means 200; The compressor control means 400 controls the capacity of the compressor 5 to be increased within the range set in step 300 until the window glass 16 is defogged.

(Function) Therefore, as described above, when the fogging determining means 100 determines that the window glass 16 of the automobile is fogged, the compressor controlling means 400 controls the capacity of the compressor 5 to be increased. Similar to the conventional example, in such a case, the maximum capacity of the compressor 5 according to the output from the temperature data generating means 200 is set by the maximum capacity setting means 300, and the maximum capacity of the compressor 5 is set so as not to exceed the set value. Since the capacity is controlled, it is possible to prevent the capacity of the compressor 5 from becoming excessive, and therefore the above-mentioned object can be achieved.

(Example) In FIG. 2, an air conditioner for an automobile has an air conditioning duct 1 whose one end opens into a vehicle interior 15.
A blower 2, an evaporator 3, and a heater core 4 are arranged in this order. The blower 2 sucks inside air or outside air from the upstream side of the air conditioning duct 1 and sends it to the downstream side.

The evaporator 3 is connected to piping together with a compressor 5, a condenser 6, a liquid tank 7, and an expansion valve 8 to form a refrigeration cycle 9. The compressor 5 is of a known capacity variable type, for example, if it is a swash plate type, the angle of the swash plate is changed, if it is a vane type, the number of effective vanes is changed, or a solenoid valve is provided in the recirculation passage.
The amount of refrigerant returned to the suction side is adjusted by the opening degree of this solenoid valve, and an actuator 5a is used to adjust the capacity, and an i-magnetic valve is used to connect and disconnect the compressor 5 with an engine (not shown). and a latch 5b.

The heater core 4 is configured to heat the air passing through the heater core 4 through which cooling water of an engine (not shown) is circulated, and an air mix door 11 is provided in front of the heater core 4 . The air mix door 11 adjusts the ratio of air passing through the heater core 4 to air bypassing the heater core 4 by the opening degree of the air mix door 11. The air is mixed and temperature-controlled on the downstream side of the heater core 4, and the defrost outlet 12, vent outlet 13, and heat outlet 1 are formed at the rear end of the air conditioning duct 1.
The air is blown out into the vehicle compartment 15 via 4.

These air outlets 12 to 14 are selected by opening and closing a mode door (not shown), but the defrost air outlet 12 that opens along the front window glass 16 constituting the vehicle interior 15 is normally selected from the window glass 16. It will be opened automatically or manually when cloudy weather occurs.

The microcomputer 17 includes a central processing unit CPU, a read-only memory ROM, and a random access memory RAM.
This microcomputer 17 is connected to an A/D converter 18. This A/
A multiplexer 19 is connected to the D converter 18, and this multiplexer 19 is further connected to, for example, a dew condensation sensor 20 provided on the above-mentioned window glass 16 to detect fogging of the window glass 16, and a vehicle interior sensor to detect the temperature inside the vehicle interior. sensor 21
, a temperature setting device 22 that sets the temperature inside the vehicle interior, and an outside air sensor 23 that detects the outside air temperature are connected. and,
Analog signals from these sensors or setters 20 to 23 are selected by a multiplexer 19, and the A/D converter 1
8 converts it into a digital signal and inputs it to the microcomputer 17. The microcomputer 17 also has an A/C command that commands the on/off mode of the compressor.
C switch 24 is connected.

The output side of the microcomputer 17 is a drive circuit 25.
The motor of the blower 2 and the compressor 5 are connected via a to 25d.
actuator 5a and electromagnetic clutch 5b, and an actuator l for driving the air mix door 11.
The microcomputer 17 controls the blower 2, compressor 5, and air mix door 11 based on the above-mentioned input signals.

In FIG. 3, the compressor control routine of the microcomputer is shown, and the microcomputer starts calculations for compressor control from step 30.
In step 31, it is determined whether dew has formed on the window glass 16 based on the output from the dew condensation sensor 20 described above. The process of step 31 and the dew condensation sensor 20 constitute the cloudy determination means 100 shown in FIG.

If it is determined in step 31 that there is no condensation, the process proceeds to step 32, where a normal compressor is operated. That is, the capacity is controlled to correspond to the required blowing temperature. on the other hand,
If it is determined in this step 32 that there is dew condensation, the process proceeds to the next step 33.

In this step 33, the above-mentioned in-vehicle sensor 21
Input the output from and store this value as Tr.

This step 33 and the in-vehicle sensor 21 constitute the temperature data generating means 200 shown in FIG.

In the next step 34, the maximum allowable capacity C, . . . of the compressor is determined based on the vehicle interior temperature Tr.

That is, as shown in FIG. 4, when the inside temperature Tr is low, the allowable maximum capacity CIIIX of the compressor is the minimum, but as the inside temperature Tr rises, it increases, and when the inside temperature Tr exceeds a predetermined value. If so, it will be at full capacity. This step 34 constitutes the maximum capacity setting means 300 shown in FIG.

Then, proceeding to the next step 35, it is determined whether the compressor is in the on mode based on the output of the A/C switch 24 mentioned above. If the compressor is in ON mode, proceed to step 36.

In this step 36, a control signal is outputted to increase the previous compressor capacity by one level. However, it is assumed that the maximum allowable capacity xcmax set in step 34 is not exceeded. On the other hand, if it is determined in step 36 that the compressor is not in the on mode, that is, in the off mode, the process advances to step 37;
In step 7, the compressor was not driven last time, so first set the compressor to the minimum capacity and start driving, and from the next time onwards, gradually increase the capacity to prevent the engine from suddenly driving the compressor. Reduce load fluctuations. However, in this step 37 as well, the allowable maximum capacity Cm set in step 34
ax shall not be exceeded. The compressor control means 400 shown in FIG.
is configured.

When the processing in steps 36 and 37 is completed, the process proceeds to step 38. In this step 38, a timer built into the microcomputer is started. Then, in the next step 39, the process waits until the timer is up, and in the next step 40, the timer is stopped, and the process returns to the first step 31.

Therefore, if there is condensation on the window glass 16, steps 31.33 to 35.36 or 37.degree. 38 to 40 are repeated, and the capacity of the compressor 5 is increased to the maximum allowable capacity. However, if the fog on the window glass 16 clears while the capacity of the compressor 5 is being increased, the determination in step 31 will be reversed to "NO" and normal control will be performed from then on. .

In FIG. 5, another embodiment of the present invention is shown, in which steps 33 and 34 are replaced with steps 41 to 43 in comparison with the previously described embodiment. That is, in step 41, the signal Tr from the in-vehicle sensor 21 and the signal Td from the temperature setting device 22 are input, in step 42, the deviation ΔT is calculated, and in step 43
By using this deviation ΔT as a variable, the capacity of the compressor is controlled within the range of the maximum allowable capacity, as in the previous embodiment.

(Effects of the Invention) As described above, according to the present invention, even if the window glass of a car becomes foggy, the capacity of the compressor can be increased within the allowable maximum capacity corresponding to the temperature inside the car. This makes it possible to limit the increase in compressor capacity when the temperature inside the car is low, prevent the temperature inside the car from getting too cold, and efficiently prevent the window glass from fogging up while providing a good feeling. It is possible.

[Brief explanation of drawings]

Fig. 1 is a block diagram showing an outline of the present invention, Fig. 2 is a block diagram showing an embodiment of the invention, Fig. 3 is a flowchart showing an example of the control operation of the microcomputer used in the above, and Fig. 4 is a diagram showing the inside of the vehicle. FIG. 5 is a characteristic diagram showing changes in maximum allowable capacity with respect to temperature, and a flowchart showing another embodiment. 1... Air conditioning duct, 3... Evaporator, 5...
Compressor, 9... Refrigeration cycle, 15... Vehicle interior, 16... Window glass, 100... Fogging determination means, 2
00...Temperature data generation means, 300...Maximum capacity setting means, 400...Compressor control means. Figure 1

Claims (1)

[Scope of Claims] 1. A refrigeration cycle including an air conditioning duct whose one end opens into a vehicle interior, an evaporator disposed within the air conditioning duct, and a variable capacity compressor that compresses refrigerant evaporated by the evaporator; fogging determination means for determining whether or not fogging has occurred on the window glass constituting the vehicle interior; temperature data generation means for generating data regarding the temperature within the vehicle interior; and the compressor according to the output of the temperature data generation means. maximum capacity setting means for setting the maximum allowable capacity of the
Compressor control means for controlling the capacity of the compressor to increase the capacity of the compressor until the fog is cleared from the window glass within the range set by the maximum capacity setting means when the fogging determination means determines that fogging has occurred. An air conditioner for an automobile characterized by comprising: 2. The air conditioner for an automobile according to claim 1, wherein the temperature data generating means is comprised of an in-vehicle sensor that detects the temperature inside the vehicle interior. 3. The temperature data generation means includes an in-vehicle sensor that detects the temperature in the vehicle interior, a temperature setting device that sets the temperature in the vehicle interior, and a deviation calculation device that calculates the deviation between the outputs of the in-vehicle sensor and the temperature setting device. An air conditioner for an automobile according to claim 1, characterized in that it is comprised of: