JPH0257419A - Air conditioner for vehicle - Google Patents

Abstract

PURPOSE:To prevent the blow-out of cold air at the start of heating and enable the rapid rise of room temperature by changing over blast stoppage and defroster blast in accordance with the judged result of an outer air temperature when a cooling water temperature is lower than a defined value. CONSTITUTION:A changeover door 20, a blower 30, an evaporator 40, a heater 50, an air mix damper 60, and changeover doors 70, 80 are provided inside an air duct 10. The heater 50 is drivingly controlled by a microcomputer 99 via a driving circuit 31 while also controlling the air mix damper 60 and the changeover doors 70, 80 thereby via servomotors 61-81, based on the detected signals of various sensors 91a-94, etc. In this case, the microcomputer 99 judges whether the detected value of an outer air temperature sensor 91b is higher than a defined value. When the detected value of a cooling water temperature sensor 92a is lower than a defined value, blast is stopped if the outer air temperature is lower than the defined value while carrying out defroster blast if the outer air temperature is higher than the defined value.

Description

[Detailed description of the invention]

[Industrial Field of Application] The present invention relates to an improvement in the initial stage of heating in a vehicle air conditioner. BACKGROUND ART Conventionally, engine cooling water has been used as a heating source in vehicle air conditioners. For this reason, empty F! ] If the cooling water is cold when the system is started, cold air will blow into the passenger compartment, causing discomfort to the occupants. To prevent this, the air blowing can be stopped until the cooling water temperature exceeds a predetermined value, but if the predetermined value is too high, the room temperature will rise slowly, and if the predetermined value is low, cold air will still blow out. , which has the disadvantage of causing discomfort. In order to improve this drawback, we set a temperature range in the low temperature range of the cooling water, stop the air blowing until the cooling water temperature exceeds the lower limit of that temperature range, and when the cooling water temperature is within that temperature range, the cooling A device is known that controls the amount of air blown to be gradually increased as the water temperature rises (Japanese Patent Application Laid-open No. 130811/1983). Also, a control method is known in which during a warm-up period in a certain temperature range, a defroster is used to relieve the cold sensation.

[Security to be Solved by the Invention 8] However, even if the air volume is proportional to the cooling water temperature as described above, the air blowing will be stopped during the period when the cooling water temperature is below the lower limit of the temperature range. , the rise in room temperature becomes slower. However, if air is directly blown into the room in a temperature range below the lower limit, the cold air will still hit the occupants and cause discomfort. Also, even if the feeling of coldness can be alleviated by defroster air,
There is a limit, and if the outside temperature is low, the airflow inside the vehicle will cause the occupants to feel cold. The present invention is based on the f! l! This was developed to solve the problem, and its purpose is to eliminate the discomfort caused by blowing cold air at the beginning of heating and to achieve a faster rise in room temperature.

[Means to solve the problem]

In order to solve the above problems, the present invention uses engine cooling water as a heat source for air conditioning, and the cooling water temperature is between a first predetermined temperature and a second predetermined temperature lower than the first predetermined temperature. Sometimes, in a dual-use air conditioner that gradually increases the amount of air blown as the temperature of the cooling water increases, an outside temperature sensor detects the outside temperature, and a check is made to determine whether the temperature detected by the outside temperature sensor is higher than a predetermined value. cooling water temperature determining means for determining whether or not the cooling water temperature is lower than a second predetermined temperature; and an air blowing control means for switching between stopping air blowing and defroster air blowing according to the determination result by the outside temperature determining means.

[Effect]

In the present invention, when the cooling water temperature is lower than a second predetermined temperature, it is determined whether the outside air temperature is lower than a predetermined value,
When the outside air temperature is lower than a predetermined value, the air blowing is stopped, and when the outside air temperature is higher than the predetermined value, the defroster air is turned on. Therefore, when the outside air temperature is low and the slight airflow inside the vehicle interior makes the occupants feel cold, the air blowing is stopped in favor of comfort. On the other hand, if the outside air temperature is not very low, if you use a defroster instead of blowing air directly to the occupants, even if the cooling water temperature is low, the occupants will not feel cold. Since the amount of heat from the initial heating of the water can be supplied to the vehicle interior, the room temperature rises more quickly.

【Example】

FIG. 1 shows an example in which the present invention is applied to a known air conditioning system for a vehicle.Inside the air duct 10 of this air conditioning system, a switching door 20. Blower 30° Evaporator 40.
Heater 50. Air mix damper 60 and switching door To
, 80 are arranged. The switching door 20 introduces outside air into the air duct 10 from outside the vehicle when the inlet 11 of the air duct 10 is manually opened.
When the recirculation port 12 is opened, the air in the vehicle interior 13 is recirculated into the air duct 10. The blower 30 sucks air from the inlet 11 or the reflux port 12, and sends it to the evaporator 40 as an air flow having a flow ff1W depending on the rotational speed of the air. The evaporator 40 cools the airflow from the blower 30 in cooperation with a cooling system including an electromagnetic clutch 41 and a compressor 42, and applies the cooled airflow to the air mix damper 60 as a cooling airflow. still,? [! MIA clutch 41 is driven under the control of electric control circuit 90 to selectively connect compressor 42 to internal combustion engine E. The heater 50 receives cooling water from the cooling device of the internal combustion engine E and warms the cooling air flow sent from the evaporator 40 . The air mix damper 60 is connected to a rod 62 of a J-bo motor 61, and when the servo motor 61 rotates by inputting a control signal from a control device 90 and moves the rod 62 upward or downward, the air mix damper 60 moves upward or downward. Opening type, the rod 62
It functions to decrease or increase depending on the upward or downward movement of . As a result, part of the cooling airflow from the evaporator 40 is applied to the heater 50 according to the opening degree of the air mix damper 60, while the remaining part of the cooling airflow from the evaporator 40 is applied to the heater 50. The mixed air flow is mixed with the air flow warmed by the air flow and sent to the switching door 70 as a mixed air flow. In this case, the air mix damper 60 has a minimum opening degree when the rod 62 is at the upper moving end in the drawing, and the entire cooling air flow from the evaporator 40 is directly applied to the switching door 70. On the other hand, when the rod 62 is at the lower moving end, the air mix damper 60 has the maximum opening degree, and the entire cooling airflow from the evaporator 40 is applied to the heater 50. The switching door 70 is operatively connected to a servo motor 71, and when the servo motor 71 is at the home position, the mixture flowing through the air duct 10 is maintained at the home position (indicated by the solid line in FIG. 1). The airflow is blown out into the passenger compartment 13 through the air outlet 14 of the air duct 10. This means that the switching door 70 is placed in heat mode. Further, the switching door 70 cooperates with the switching door 80 to blow out the mixed air flow into the passenger compartment 13 from the air outlet 14 , 15 of the air duct 10 or into the passenger compartment 13 from the air outlet 16 of the air duct 10 . Function. This means that the switching door 70.80 is in vent mode. This means that it is in pie level mode or defroster mode. Note that the switching door 70 is operated by a servo motor 7.
The switching door 80 is moved downward by rotation according to a command from the control device 90 and placed in vent mode, pie level mode, or defroster mode, and the switching door 80 is moved upward or downward by rotation according to a command from the control device 90. to put it in vent mode, pie level or defroster mode. The electric control circuit 90 includes various sensors 91a, 91b, 92
A-D connected to a, 92b, 93a, 93b and 94
It includes a converter 98, a microcomputer 99 connected to a temperature setter 95, a mode setter 96, and a control switch mechanism 97. The inside temperature sensor 91a is arranged inside the vehicle interior 13, detects the actual temperature T inside the grass hall 13, and generates an analog signal having a level corresponding to this inside temperature T. The outside temperature sensor 91b is placed close to the front grill of the vehicle radiator, and detects the actual temperature T of the air outside the vehicle.
am is detected, and an analog signal having a level corresponding to this outside temperature Tam is generated. The water temperature sensor 92a is disposed close to the inlet of the heater 50, detects the actual temperature Tw of the cooling water from the cooling device, and generates an analog signal having a level corresponding to the detected water temperature Tw. The air temperature sensor 92b is disposed close to the outlet of the evaporator 40, and detects the actual temperature T of the air flow from the evaporator 40. generates an analog signal having a level corresponding to . The opening sensor 93a is operatively connected to a rod 62 that is moved up and down by a servo motor 61, detects the actual opening A of the air mix damper 60, and uses this detected opening formula,
generates an analog signal having a level corresponding to . The opening sensor 93b is operatively connected to a rod that is moved up and down by the servo motor 71, detects the actual opening position A of the switching door 70 in relation to the displacement of this rod, and calculates the detection result. generates an analog signal having a level corresponding to . The solar radiation sensor 94 is arranged near the window of the vehicle interior 13, detects the actual solar radiation mTs, and generates an analog signal having a level corresponding to the actual solar radiation mTs. Based on a request from the microcomputer 99, the A-D converter 98 converts the analog signals from the sensors 9], a to 94 into digital signals, and converts these digital signals into internal temperature T r + opening degree A1. ．． Opening position Ap
, outside temperature Tam, water temperature T, air temperature T, and day flJ
Microcomputer 99 as a representation of fftTs
granted to. The temperature setting device 95 is provided in the vehicle compartment 13, and a desired temperature setting Tset is selected by manual operation by a passenger and is generated as a temperature setting signal. The mode setter 96 is composed of a plurality of manual switches, and by actuating any one of these switches, a command signal representing heat mode, pie level mode, vent mode, or defroster mode is generated. The control switch mechanism 97 is composed of first to fourth self-returning operation switches, and the first control switch generates a first command signal necessary for placing the blower 30 under automatic control by its operation. . Second. The third and fourth operation switches are operated to set the fiW of the airflow generated from the blower 30 to a predetermined high flow value 1 (intermediate flow value M, and low flow value), respectively. The microcomputer 99 is composed of a single-chip LSI, and receives a constant voltage from a constant voltage circuit (not shown) to be in a ready state. The computer 99 includes a CPU, ROM, RAM, an input/output interface (hereinafter referred to as I10), and a clock circuit.The RAM is connected to the A-D converter 98 through Ilo.
, the temperature setting signal from the temperature setting device 95, and each command signal from the mode setting device 96 and the control switch mechanism 97, temporarily storing the signals, and selectively applying these signals to the CPU. do. Further, in this embodiment, the RAM is constantly supplied with power from the DC power supply B and has a memory retention function. A predetermined control program is stored in the ROM, and the CPU changes the flow m signal representing the blown air ff1W, the optimum opening degree S11 of the air mix damper 60, and the actual opening degree according to the control program. <5ll) and the first opening signal representing the difference between the actual opening ^1 and the optimal opening! A second opening signal representing the difference from J (A, >SW) is generated. Furthermore, by executing the control program, the CPU generates a first opening position signal representing the difference between the optimum position Apo of the switching door 70 and the actual opening position AP (AP<static 0), and the actual opening position Apo. , and the optimum opening position Ap. (Static o<8p) A second opening position signal representing the difference between the opening position and the switching position of the switching door 80 is generated. With such a control signal, the air volume becomes the commanded value, the air mix damper 60 becomes the commanded opening degree, and the switching door 7
0 and the switching door 80 take the commanded position. Next, the control method will be explained with reference to FIG. In step 100, various sensors, ie, water temperature sensor 92a, inside temperature sensor 91a, outside temperature sensor 91b,
1 Output value of solar radiation sensor 94 and various setting devices 95.96
The output value of the control switch mechanism and the state output value of the control switch mechanism are input. Next, in step 102, the required blowout temperature TAO is calculated from these values, and in step 104, the opening degree and blowout mode of the air mix damper 60 determined by the required blowout temperature TAU are determined. Next, proceeding to step 106, the wind Hw is calculated from the required blowout temperature TAU,
In the next step 108, the blowout mode is determined, and +l
[lATMoP or mouth/1. If it is the mode, the process moves to step 110 and subsequent steps, and 11 controls, which are the characteristic features of the present invention, are executed. In step 110, it is determined whether the outside temperature Tam is 15 degrees Celsius or less, and if the outside temperature Tam is 15 degrees Celsius or less, the process moves to step 112, and the process is performed according to the cooling water temperature Tw measured at that time. The wind ff1W is calculated. That wind fi
W is determined by the characteristic shown by the solid line A in FIG. That is, when the water fiTw is lower than 30°C, the wind ff1W is zero, and when the water temperature Tw is in the temperature range from the second predetermined temperature of 30°C to the first predetermined temperature of 50°C, the wind mW is the water temperature. T
It is determined in proportion to w, and when the water temperature ↑W becomes 50° C. or higher, the air volume becomes constant, and is then controlled to the specified or optimal air volume by the control switch mechanism 97 or the like. Further, the blowing mode is set to the IIEAT mode or the pie level mode as shown by the solid line A in FIG. And step 118
And that! A control signal for controlling the rotational speed of the blower 30 to achieve ff1W is output to the drive circuit 31, and a control signal for controlling the switching doors 70 and 80 to the determined mode positions is output to the servo motors 71 and 81. . If it is determined in step 110 that the outside air temperature Tan is not below 15°C, the process proceeds to step 114, where it is determined whether the cooling water temperature Tw is below 30°C. Then, if the cooling water temperature Tw is not below 30°C, step 11
2, the wind fiW is calculated based on the cooling water temperature Tw, and in step 118, a control signal for realizing the wind fiW is output to the drive circuit 31. That is, in the characteristics shown in FIG. 3, of the characteristics shown by the - dotted chain line B, water temperature
This is the characteristic part where the temperature exceeds 0°C. This part is the same as the case where the outside air temperature is 15° C. or lower as described above. If it is determined in step 114 that the cooling water temperature Tw is 30° C. or lower, the process proceeds to step 116 where the defroster mode is set and the air ff1W is determined to be a constant air volume L0. Then, the process moves to step 118, and a control signal for controlling the positions of the switching doors 80 and 70 to switch to the defroster mode is output to the servo motors 81 and 71, and a control signal for setting the air volume to Lo is output to the drive circuit 31. . As a result, the switching doors 80 and 70 are switched to the defroster air blowing side, and the blower 30 is rotated at a rotational speed that provides the air volume L0. That is, in FIG. 3, the defroster mode is controlled by the wind ff1L shown by characteristic B in the range where the water temperature Tw is 30° C. or less, and the defroster mode is set as shown in the part where the water temperature Tw of characteristic B shown in FIG. 4 is 30° C. or less. .

【Effect of the invention】

In the present invention, when the cooling water temperature is lower than the second predetermined temperature, the air blowing control sub-actor switches between stopping air blowing and defroster air blowing according to the determination result by the outside air temperature determining means, so that the outside air temperature is lower than the second predetermined temperature. If the air temperature inside the vehicle is low and the slight airflow inside the vehicle makes the occupants feel cold, the system will prioritize comfort and stop blowing air, and if the outside temperature is not too low, it will not blow air directly to the occupants. Defroster blows air. Therefore, the occupants do not feel cold, and depending on the outside temperature, the room temperature can be raised quickly.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the configuration of an air conditioner according to a specific embodiment of the present invention. FIG. 2 is a flowchart showing the processing procedure of the CPU used in the control device of the device of the embodiment. FIGS. 3 and 4 are characteristic diagrams showing operating characteristics. 30...Blower 31...Drive circuit 50...Heater 60...-Air mix standby To, 80...Switching door 90...Control device patent applicant Nippondenso Co., Ltd. Agent Patent attorney Osamu Fujitani

Claims (1)

[Claims] Engine cooling water is used as a heat source for air conditioning, and the cooling water temperature is the first
and a second predetermined temperature lower than the first predetermined temperature. an outside temperature sensor that detects a temperature detected by the outside temperature sensor; an outside temperature determination means that determines whether the temperature detected by the outside temperature sensor is higher than a predetermined value;
cooling water temperature determining means for determining whether or not the cooling water temperature is lower than a second predetermined temperature; and if the cooling water temperature is lower than a second predetermined temperature, stopping air blowing and defroster air blowing according to a determination result by the outside air temperature determining means. An air conditioner for a vehicle, characterized in that it is equipped with an air blow control means for switching.