JPH0619368Y2 - Automotive air conditioner - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention relates to an air conditioner for an automobile, and more particularly to an air conditioner equipped with a variable displacement compressor.

(Prior Art) Conventionally, as an apparatus of this type, for example, the actual exploitation 63-37
As disclosed in Japanese Patent No. 411, in a compressor in which driving of the compressor is intermittently performed according to the temperature of the evaporator, reference temperatures for intermittently providing the compressor are provided at the time of introducing the outside air and at the time of introducing the inside air, and at the time of introducing the inside air. It is publicly known that the reference temperature of is set lower than that at the time of introducing the outside air to enhance the dehumidifying ability of the evaporator at the time of introducing the inside air.

(Problems to be solved by the invention) However, since the operation of the cooling cycle is accompanied by a delay, in the above-mentioned conventional example, the temperature of the evaporator is expected to decrease to near the reference temperature and the dehumidifying ability is expected to improve. It takes a certain amount of time after the inside / outside air switching door is switched until the ready state is reached. on the other hand,
Since the intake air temperature and the intake humidity of the evaporator rise by introducing the inside air, the dehumidification amount becomes insufficient until the evaporator becomes sufficiently low temperature, and there is a problem that clouding occurs in the vehicle window immediately after introducing the inside air. there were.

This also applies to a device using a variable capacity compressor, and particularly when the outside air temperature is, for example, 5 ° C. or lower, that is, a so-called low outside air temperature, when the compressor is operated for the purpose of demisting to introduce the outside air, Since the compressor is operated with a small capacity, there is a problem that dehumidification becomes insufficient and cloudy occurs in the vehicle window immediately after the introduction of the inside air, for the same reason as in the case of the fixed capacity type compressor described above.

Then, this invention solves the problem of the said prior art example, prevents generation | occurrence | production of cloudy weather immediately after an inside / outside air switching door switching, and makes it a subject to provide the air conditioning system for vehicles which can contribute to the safe driving of a vehicle. It is a thing.

(Means for Solving the Problems) As shown in FIG. 1, the vehicle air conditioner according to the present invention has a variable capacity compressor 18 capable of varying the discharge capacity in accordance with an external signal and an inside / outside air switching door. Target cooling temperature setting means 100 for setting the target cooling temperature of the evaporator in accordance with the position, cooling temperature detecting means 110 for detecting the substantial cooling temperature of the evaporator, and the target set by the target cooling temperature setting means 100. An automotive air conditioner comprising: a drive control means 120 for controlling the capacity of the variable capacity compressor 18 so that a deviation between a cooling temperature and a detection value detected by the cooling temperature detection means 110 becomes a predetermined value or less, Immediately after the inside / outside air switching door is switched from the outside air introducing position to the inside air introducing position, the target cooling temperature setting means 100 sets the temperature. The cooling temperature correction means 130 is provided to reduce the target cooling temperature by a predetermined amount and then return it to the original target cooling temperature in a predetermined time.

(Operation) Therefore, immediately after the inside / outside air switching door is switched from the outside air introduction position to the inside air introduction position, the target cooling temperature is higher than the value when the cooling temperature correction means is in a thermally stable state in the inside air introduction state. As a result of being temporarily lowered to a lower value, the compressor is driven with a large capacity by the drive control means, so that an increase in air temperature and humidity immediately after the evaporator is suppressed immediately after the door is switched. Then, after that, the target cooling temperature is gradually returned to the value set by the target cooling temperature setting means, so that a large capacity operation of the compressor more than necessary is avoided, and therefore, the above-mentioned problem can be achieved.

(Embodiment) An embodiment of the present invention will be described below with reference to the drawings.

In FIG. 2, the vehicle air-conditioning control device includes an air-conditioning duct 1
The intake door switching device 2 is provided on the most upstream side of the intake door switching device 2. In the intake door switching device 2, the inside air / outside air switching door 5 is arranged at a portion where the inside air inlet 3 and the outside air inlet 4 are separated. Is operated by the actuator 6 so that the air introduced into the air conditioning duct 1 can be selected between the inside air and the outside air.

The blower 7 sucks air into the air conditioning duct 1 and blows the air downstream, and an evaporator 8 and a heater core 9 are provided behind the blower 7.

An air mix door 10 is provided in front of the heater core 9, and the opening of the air mix door 10 is adjusted by an actuator 11 so that the heater core 9 is
The ratio of the air that passes through and the air that bypasses the heater core 9 is adjusted. Further, the downstream side of the heater core 9 is divided into a defrost outlet 12, a vent outlet 13, and a heat outlet 14 to open in the vehicle compartment, and mode doors 15a and 15b are provided at the divided portions. 15b is the actuator 1
The blowing mode can be switched by operating 6 and 17.

The evaporator 8 constitutes a cooling cycle together with a variable capacity compressor 18, a condenser 19, a liquid tank 20 and an expansion valve 21 described below. The variable capacity compressor 18 is, for example, a wobble plate type, and as shown in FIG.
A drive shaft 24 connected to the engine 22 via the is inserted into the compressor body 25, and a wobble plate 26 is connected to the drive shaft 24 via hinge balls 27. This wobble plate 26 is a compressor body 25.
A crank chamber 28 formed inside is swingably supported on a drive shaft 24 with a hinge ball 27 as a fulcrum, and a piston 29 connected to the wobble plate 26 is connected to a cylinder bore 30 according to a swing angle. It is designed to reciprocate inside. Further, the variable capacity compressor 18 is provided with a pressure control valve 31 so as to face the crank chamber 28,
The pressure control valve 31 includes a valve body 33 that adjusts a communication state between the crank chamber 28 and a suction chamber 32 that communicates with the suction side, and a pressure responsive member 34 that moves the valve body 33 according to the pressure in the suction chamber 32. , and a solenoid 36 for moving the valve body 33 in accordance with the current amount _{I SOL} to the electromagnetic coil 35, by controlling the current amount _{I SOL} to the electromagnetic coil 35 from the outside, between the piston 29 and the cylinder bore 30 The amount of blow-by gas that leaks into the crank chamber 28 from the space is returned to the suction side. Then, the capacity variable device 37 for changing the capacity of the variable capacity compressor 18 is constructed from the pressure control valve 31 and the like, and when the energization amount I _SOL flowing through the electromagnetic coil 35 is increased and the magnetic force of the solenoid 36 is increased, the valve body 33 is moved. A force acts in the direction to reduce the communication between the crank chamber 28 and the suction chamber 32, and the amount of blow-by gas leaking from the crank chamber 28 to the suction chamber 32 is reduced. Therefore, the pressure in the crank chamber 28 increases and the piston 29
Since the force acting on the back surface of the wobble plate 26 increases, the wobble plate 26 rotates about the hinge ball 27 in the direction in which the swing angle decreases, and the stroke of the piston 29, that is, the capacity of the compressor decreases.

The variable capacity device 37 not only controls the amount of blow-by gas to the suction side by the pressure control valve, but also changes the number of cylinders used by the compressor, and a belt transmission device that connects the compressor and the engine 22. The pulley ratio may be changed, or the number of effective vanes in the vane type compressor may be changed so long as the capacity is substantially changed.

The actuators 6, 11, 16 and 17, the motor 7a of the blower 7, the electromagnetic clutch 23 of the variable capacity compressor 18 and the capacity varying device 37 are output to the output signals from the microcomputer 41 via the drive circuits 40a to 40f, respectively. It is controlled based on. The microcomputer 41 includes a central processing unit (CPU) (not shown),
A well-known device having a read-only memory (ROM), a random access memory (RAM), an input / output port (I / O), and the like. The microcomputer 41 has a vehicle interior temperature sensor for detecting the temperature inside the vehicle interior. 42, the vehicle interior temperature T _R , the outside air temperature T _A from the outside air temperature sensor 43 that detects the temperature of the outside air, the insolation amount T _S from the insolation sensor 44 that detects the insolation amount, and are provided on the downstream side of the evaporator 8. The air temperature T _INT immediately after the evaporator from the air temperature sensor 45 immediately after the evaporator that detects the temperature of the air on the downstream side of the evaporator 8 (hereinafter referred to as the “air temperature immediately after the evaporation”) and the refrigerant that is input to the evaporator 8. The refrigerant temperature T _REF from the refrigerant temperature sensor 46 that detects the temperature of the A / D converter 4 is selected via the multiplexer 47.
It is converted into a digital signal via 8 and input.

Further, an output signal is input to the microcomputer 41 from the operation unit 49. The operation unit 49 connects and disconnects the automatic control state (AUTO) as the control state of the air conditioner.
A UTO switch, a switch for changing the inside / outside air (INTAKE DOOR) 5, a switch for manually setting the speed of the blower 7, and a temperature setting switch (not shown) for setting the temperature inside the vehicle Is.

Next, the basic control of this apparatus by the microcomputer 41 described above will be explained with reference to the main flow chart shown in FIG.

First, the microcomputer 41 starts execution from step 200, proceeds to step 202, and initializes various variables and flags.

In the next step 204, the above-mentioned vehicle interior temperature sensor 42
A detection signal or the like is input from the above, and the process proceeds to step 206. In step 206, the target blowing temperature X _M of the air blown into the vehicle compartment is calculated using the detection signal input in step 204 described above, for example, according to the following equation.

X _M = A ・ T _D + B ・ T _R + C ・ T _A + D ・ T _S + E (1) where A, B, C and D are calculation coefficients and E is a calculation constant. . Further, _{T D} is the set temperature, _{T R} is the cabin temperature, _{T A} is the ambient air temperature, _{T S} is the amount of solar radiation.

Then, the process proceeds to the next step 300, the opening degree of the air mix door 10 is calculated with respect to the above-mentioned target outlet temperature X _M , and the air mix door 10 is rotated via the drive circuit 40b so as to reach this opening degree. It Here, the target outlet temperature X
Rotational speed of the opening degree blower 7 of the air mix door 10 with respect to _M, mode doors 15a, 15b door position of, is predetermined with door position inside and outside air switching door 5, for example, an air mixing door opening for this X _M RO characteristic
The opening degree is controlled using an M-shaped one.

Thereafter, the processes of steps 400 to 700 are basically the same as those of step 300 described above (the blower 7, the mode doors 15a and 15b, and the inside / outside air switching door 5).
Drive control is performed.

In step 700, the drive control of the variable displacement compressor 18 is performed, but its control state can be variously changed according to the state immediately after the start-up and the steady state or the running state. In this step 700, various control subroutines are variously selected and appropriate. Compressor control is performed. This step 700
After the above process, the process returns to the above-mentioned step 204 and the above-mentioned processes are repeated.

FIG. 5 shows step 700 of the main routine described above.
The flow chart of the capacity control routine performed in FIG. 3 is shown, and the contents will be described below with reference to the same figure.

First, the microcomputer 41 starts execution from step 702 and proceeds to step 704 to determine whether the inside / outside air switching door 5 has been switched from the outside air introducing position to the inside air introducing position. If it is determined that the outside air introduction (FRE) position is switched to the inside air introduction (REC) position (YES), the process proceeds to step 710, and if not (NO), the inside air introduction (RE) is continuously performed at step 708.
C) Judge whether it is the position or not. In the case of the inside air introduction (REC) position (YES), the process proceeds to step 710, and in other cases (NO), the process returns to the main routine via step 720.

In step 710, it is determined whether or not the elapsed time t after switching from the outside air introduction (FRE) position to the inside air introduction (REC) position in step 704 has reached the predetermined time t ₁ . If the predetermined time t ₁ has elapsed (YES), the process proceeds to step 712, where the immediately-after-air temperature T _INT detected by the immediately-after-air temperature sensor 45 is a predetermined value α.
_It is determined whether it is ₁ or more or a predetermined value α ₂ or less. If T _INT is larger than the predetermined value α ₁ (A), the process proceeds to step 714. If it is smaller than α ₂ (B), the air temperature T immediately after the evaporation T
_Assuming that _INT is below the freezing limit, the routine proceeds to step 718, the operation of the variable displacement compressor 18 is stopped, and the routine returns to the main routine via step 720.

On the other hand, in step 710, when the predetermined time t ₁ is not reached (NO), the air temperature T _INT immediately after the evaporation is equal to or lower than the freezing limit, that is, when it is smaller than α ₂ in step 712 (B), the freezing is actually stopped. Does not occur, the process proceeds to step 714 without going through step 712.

Here, the specific value of t _1, for example, t _{1 =} about 5 minutes is used.

At step 714, the air temperature T _INTS is calculated immediately after the target evaporation. Air temperature T immediately after this target evaporation
_INTS is the air temperature immediately after the evaporator 8 which is to be obtained by the variable capacity electric power transfer of the variable capacity compressor 18, and is set according to the following equation.

However, T _A is the outside air temperature, T is a predetermined time constant, for example, 60
Seconds are set. Further, at t, the elapsed time after the inside / outside air switching door 5 is set to the inside air introduction position is the present step 714.
Is set each time is executed. T at step 714
_{After INTS} is calculated, the process proceeds to step 716 | T
_The displacement of the variable displacement compressor 18 is controlled so that _INT- T _INT | <1. That is, | T _INT −
When the value of T _INTS | is large, the capacity of the variable capacity compressor 18 also greatly changes, and when T _INT −T _INTS is a positive value and large, the capacity increases, and conversely T _INT −T
_{If INTS} is a negative value and large, the capacity decreases.

Then, the capacitance changes as the value of | T _INT −T _INTS | decreases, and eventually | T _INT −T _INTS | <
When it reaches 1, the capacity becomes stable. The above operation is achieved by driving the capacity varying device 37 via the drive circuit 40b and changing the energization amount I _SOL to the electromagnetic coil 35 of the pressure control valve 31.

Steps 714 and 716 described above are repeated until the air temperature T _INTS immediately after the target evaporator reaches a steady value and then, after a few minutes, the cooling cycle is stabilized, and then the process returns to the main routine via step 720.

Here, the process from the start of the capacity control based on the above-mentioned T _INTS to the time when T _INTS becomes the steady value will be comprehensively described with reference to FIG.

First, when the inside / outside air switching door 5 is at the outside air introduction position, the absolute value of the difference between the refrigerant temperature T _REF detected by the refrigerant temperature sensor 46 and its target value T _REFS is smaller than “1”. The displacement control of the variable displacement compressor 18 is performed by another subroutine of step 700 not shown here. _As the value of T _REFS , for example, a value obtained by subtracting 4 ° C. from the outside air temperature T _A is set.

Then, when the inside / outside air switching door 5 is switched from the outside air introducing position to the inside air introducing position, the variable capacity compressor 18 operates
The capacity is controlled so that T _INT -T _INTS | <1. Here, T _INTS is or, after the switching straight As can be seen from the foregoing equation (2) (T _A -12) ° C., and the so on are exponentially increased over the subsequent time, outside air switching door 5 After a few minutes, T _INTS becomes a steady value of 0 ° C., and as long as the inside / outside air switching door 5 is in the inside air introduction position, the variable capacity compressor 18 remains | T _INT -T _INTS | <1.
The capacity is controlled so that Further, when the inside / outside air switching door 5 is switched to the outside air introduction position, the variable displacement compressor 18 is subjected to the displacement control by the other subroutine processing in the same manner as described above so that | T _REF -T _REFS | <1.

As described above, according to the present invention, the capacity of the compressor is increased immediately after the inside / outside air switching door is switched from the outside air introduction position to the inside air introduction position, and thereafter, at a predetermined rate. Since the capacity is returned to the normal stable state, the dehumidifying capacity of the evaporator is insufficient immediately after the outside air is introduced into the evaporator as in the conventional case, and clouding does not occur, which contributes to safe driving of the vehicle. That is the effect.

[Brief description of drawings]

FIG. 1 is a functional block diagram of an automobile air conditioner according to the present invention, FIG. 2 is a configuration diagram of the same automobile air conditioner, and FIG.
FIG. 4 is a sectional view of a variable capacity compressor used in the above-mentioned automobile air conditioner, FIG. 4 is a main flowchart showing an air conditioning control routine by a microcomputer used in the above automobile air conditioner, and FIG. 5 is a compressor by the microcomputer. FIG. 6 is a characteristic flowchart showing a change in the air temperature immediately after the target evaporation when the control routine shown in FIG. 5 is executed. 18 ... Variable capacity compressor, 37 ... Capacity changing device, 41 ... Microcomputer, 45 ... Air temperature sensor immediately after evaporation, 46 ... Refrigerant temperature sensor, 100 ...
Target cooling temperature setting means, 110 ... Cooling temperature detecting means,
120 ... Drive control means, 130 ... Cooling temperature correction means.

Claims (1)

[Scope of utility model registration request] 1. A variable capacity compressor capable of varying a discharge capacity according to an external signal, a target cooling temperature setting means for setting a target cooling temperature of an evaporator according to a position of an inside / outside air switching door, and a substantial cooling of the evaporator. Cooling temperature detecting means for detecting a temperature, and the variable capacity compressor such that a deviation between a target cooling temperature set by the target cooling temperature setting means and a detection value detected by the cooling temperature detecting means becomes a predetermined value or less. In a vehicle air conditioner equipped with a drive control means for controlling the capacity of, the target cooling temperature set by the target cooling temperature setting means is set immediately after the inside / outside air switching door is switched from the outside air introducing position to the inside air introducing position. A cooling temperature correction means is provided for reducing the temperature by a predetermined amount and then returning to the original target cooling temperature after a predetermined time. Automotive air conditioning system.