JPH0615290B2 - Vehicle air conditioner - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an air conditioner for a vehicle, in which frequent changes in air volume of a blower are prevented.

(Prior Art) Conventionally, there is, for example, a vehicle air conditioner disclosed in Japanese Examined Patent Publication No. 59-19849 as a vehicle air conditioner that controls the speed of a blower so as to attain a target blowout temperature based on a temperature setting.

This vehicle air conditioner calculates the target blown air temperature based on the temperature set by the occupant and the temperatures detected by the outside air temperature sensor and the vehicle interior temperature sensor, and determines the target blown air temperature to determine the vehicle interior temperature. While detecting with the temperature sensor, it switches to the inside air introduction or the outside air introduction and controls the blower at low speed or high speed according to the target blown air temperature to automatically adjust the passenger compartment temperature according to the passenger's preference. It is adjusted accordingly.

(Problems to be Solved by the Invention) However, in the above conventional vehicle air conditioner,
Since the temperature detected by the vehicle interior temperature sensor changes in accordance with the change in the blown air volume by the blower, there is a problem that so-called hunting occurs in which the blown air volume frequently changes.

Especially in a region where the blown air volume is high, the fluctuation in the temperature detected by the temperature sensor inside the vehicle also becomes large, which causes a significant change in the blown air volume due to the blower, and the occupant's discomfort due to the blown air volume fluctuation is also large. Also, there is a problem that the sound quality of the wind noise caused by the blower becomes severe, causing uncomfortable occupant discomfort.

Therefore, an object of the present invention is to solve the above problems by providing a hysteresis in a region of a control pattern in which the amount of air blown by a blower becomes large.

(Means for Solving Problems) The vehicle air conditioner of the present invention is based on an output signal from at least a vehicle interior temperature sensor that detects the temperature of the vehicle interior and a temperature setter that arbitrarily sets the vehicle interior temperature. A calculating means for calculating the control signal, and a blower driving means for driving the blower based on a control pattern in which an air volume is low in an intermediate area of the control signal from this arithmetic means and is high in a low area or a high area of the control signal. And setting a first point between the low region and the middle region of the control signal and a second point between the middle region and the high region of the control signal in the control pattern. , From the zero point of the control signal to the first
Between the points, and in a region above the second point, hysteresis is provided, and the first and second points are set to have the same air volume.

(Operation) Therefore, when the air flow rate based on the control signal is equal to or less than the predetermined air flow value, the normal air flow control is performed. In contrast,
When the air flow rate based on the control signal exceeds the predetermined air flow rate value, the blower is controlled based on the control pattern having hysteresis, and the air flow rate due to the fluctuation of the vehicle interior temperature in the large air flow rate region is controlled. You can prevent frequent fluctuations,
It is possible to prevent the sound quality of the wind noise caused by the blower from changing.

(Example) Below, one Example of this invention is described based on drawing.

FIG. 1 shows an automobile air conditioner 10, and FIG. 2 shows a schematic configuration of a control circuit 11 thereof. First, the air conditioner 10 will be described. On the most upstream side of the duct 12, an intake door 15 that switches between the inside air inlet 13 and the outside air inlet 14 is provided. Inside the duct 12, the blower 16 and the evaporator 17 are sequentially installed from the upstream side. , The mix door 18 and the heater core 19 are provided, and the passenger compartment 2 is provided on the most downstream side of the duct 12.
Vent outlet 21 and defroster outlet 2 communicating with 0
2, a foot outlet 23 is provided. The outlet 21 and the defroster outlet 22 are switched by a switching door 24 for mode switching, and the foot outlet 23 is opened and closed by a switching door 25.

The intake door 15 includes a motor actuator 33.
Is driven by the switch to switch between the outside air in the intake air and the air inside the vehicle compartment. The blower 16 is a drive circuit (blower drive means) 3
5 to suck air into the duct 12 through the intake door 15. The evaporator 17 includes a compressor 26 for compressing and circulating a refrigerant and a condenser 2
7, receiver tank 28, expansion valve 29, and cooler 3
Configures 0. The cooler 30 is driven via a magnet clutch 32 by a pulley 31 to which the power of the engine 41 is transmitted. The air introduced by the blower 16 passes through the inside of the evaporator 17 and is cooled.

Further, engine cooling water is passed through the heater core 19 to heat the air that has passed through the evaporator 17. The ratio of the air passing through the heater core 19 is set by the opening degree of the mix door 18, and the mix door 1
8 is driven by a motor actuator 37. The switching doors 24 and 25 for mode switching are driven by the motor actuator 39, select the vent outlet 21, the defroster outlet 22 and the heat outlet 23, and send out conditioned air into the vehicle interior 20.

Further, a potentiometer 42 for detecting the opening θ _x of the mix door 18 and a solar radiation amount t for detecting the intensity of solar radiation.
solar radiation sensor 43 for detecting the _s, the outside air temperature sensor 44 for detecting the outside air temperature t _a, a temperature setter 46 for setting the passenger compartment temperature sensor 45, and the passenger compartment 20 to a predetermined temperature for detecting the vehicle interior temperature t _r , And these output signals are input to the control circuit 11 via the A / D converter 47.

Further, the control circuit 11 is composed of a microcomputer having an I / O port, a CPU, a memory, etc., and by this microcomputer, as shown in FIG.
c is configured. Then, the total signal calculation means 11a
In the above, the integrated signal (control signal) T is calculated by each data input from the A / D converter 47, and the control circuit based on this integrated signal T controls the drive circuit 34 to switch the intake door 15. Control the drive circuit 36 to operate the cooler 30 via the magnet clutch 32, control the drive circuit 38 to control the opening of the mix door 18, and control the drive circuit 40 to control each switching door. Two
The blowing mode is set automatically by switching between No. 4 and No. 25. In the air volume calculation means 11b, the target air volume is calculated based on the total signal T from the total signal calculation means 11a, and the blower 16 is driven by the blower drive circuit (blower drive means) 36 based on this target air volume, and the blower 16 It is configured to control the air flow rate of.

Next, air volume control of the air conditioner will be described based on the flowchart shown in FIG. Incidentally, _P 1 to P ₇ in the figure indicate the respective steps.

First, the air volume control, at step _{P 1,} the detection signal _t s from the sensors 43, 44, _45, t a, _{t r}
And the output signal t _D of the temperature setter 46 is read. In step _{P 2,} the overall signal calculating means 11a, the respective signal _{t s, t a, t r} , using the _{t D,} the operation of the overall signal T for controlling the whole air conditioner according to the following equation is performed.

T = K _R · t _r + K _A · t _a · K _S · t _S −K _D · t _D However, K _R , K _A , K _S , and K _D respectively represent coefficients.

In step P _3, the target air volume value by the blower 16 based on the overall signal T in airflow calculating means 11b B
_{The LO} is calculated, and in step P ₄ , the determination means 11 c determines whether or not the target air volume value B _LO is larger than the preset predetermined air volume value α. The predetermined value α is determined based on the total signal T, and is set based on an air volume that does not cause an adverse effect due to hunting of the blower 16 due to a large heat load in the passenger compartment and an increase in the air flow.

If the target air flow rate value B _LO is less than or equal to the predetermined value α in step P ₄ , the content of the memory whose address is the total signal T is called in step P ₅ . In this memory, a control pattern having a predetermined value α or less as shown in step P ₅ of FIG. 3 is stored as a map. Therefore, when the target air volume value B _LO is less than or equal to the predetermined value α, the air volume control signal based on the control pattern without hysteresis is called, and this control signal is output to the blower drive circuit 35 in step P ₇ .

On the other hand, if the target air flow rate value B _LO is greater than or equal to the predetermined value α in step P ₄ , the content of the memory whose address is the total signal T is called in step P ₆ . In this memory, a control pattern having a predetermined value α or more shown in step P ₆ of FIG. 3 is stored as a map. The control pattern in this memory is configured as a pattern having hysteresis. Therefore, when the target air volume value B _LO is equal to or larger than the predetermined value α, the control signal having hysteresis is sent to the blower drive circuit 35 in step P ₇ . Is output.

In this way, since the normal control of the blower 16 is performed in the region where the hunting of the blower 16 is small, that is, in the region where the heat load in the passenger compartment is small and the amount of blown air is small, it is possible to maintain high temperature control accuracy.

In a region where the heat load in the passenger compartment is large and the amount of air blown is large, for example, in a high temperature region and a low temperature region, since the blower control with hysteresis is performed, the temperature control accuracy is slightly reduced, but Even if the indoor temperature fluctuates even slightly, the air blower does not fluctuate and stabilizes.Therefore, it is possible to reduce the frequent fluctuations in the air blower and the accompanying fluctuations in the sound quality of the wind noise caused by the blower. It is possible to improve the feeling of comfort. In this case, the temperature control accuracy is slightly lowered, but since the heat load is large in these regions, the temperature control accuracy is hardly affected.

In the above embodiment, the case where the air volume calculation means 11b, the determination means 11c, the memory map of the low air volume region and the memory map of the high air volume region are provided has been described, but the present invention is not limited to this. It is also possible to store the high air volume region and the high air volume region in one memory map, and to eliminate the air volume calculation means and the discrimination means.

(Effects of the Invention) As described above, according to the present invention, a hysteresis is provided in a range that is equal to or greater than a predetermined air flow rate value of a control pattern for driving and controlling a blower, so that a heat load in a passenger compartment is small and an air flow rate is small. Without impairing the high temperature control accuracy in the area,
It is possible to prevent frequent changes in the air flow rate in a region where the heat load in the vehicle interior is large and the air flow rate is large, and to prevent changes in the sound quality of the wind noise of the blower due to this, and to improve the passenger's comfort.

[Brief description of drawings]

1 to 3 relate to an embodiment of the present invention. FIG. 1 is a schematic configuration diagram of an air conditioner, FIG. 2 is a schematic configuration diagram of a control device, and FIG. 3 is an outline of air volume control processing. It is a flowchart. 11a ... Control signal calculation means 16, 35 ... Blower and its drive circuit 20 ... Vehicle compartment, 45 ... Vehicle interior temperature sensor 46 ... Temperature setting device T ... Control signal (overall signal)

Claims (1)

[Claims] 1. A calculation means for calculating a control signal on the basis of an output signal from at least a vehicle interior temperature sensor for detecting a temperature in the vehicle interior and a temperature setter for arbitrarily setting the vehicle interior temperature, and a computing means from the computing means. The control signal comprises a blower driving means for driving the blower based on a control pattern in which the air volume is low in the middle region of the control signal and high in the low region or high region of the control signal. A first point between the low range and the middle range and a second point between the middle range and the high range of the control signal are set, and between the zero point of the control signal and the first range. , And a hysteresis is provided in a region above the second point, and further, the first and second points are set to have the same air volume, the vehicle air conditioner.