JP2817120B2 - Intake control device for vehicle air conditioner - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an intake control device for a vehicle air conditioner using a variable displacement compressor.

[Prior Art] In a conventional vehicle air conditioner, for example,
As described in No. 53366, the required inside air temperature is calculated based on the vehicle interior temperature, the outside air temperature, the amount of solar radiation, and the set temperature,
The intake door is controlled according to the calculation result.

On the other hand, an air conditioner using a variable capacity compressor has recently appeared, and in this type of air conditioner, the capacity of the compressor is controlled in accordance with the air temperature immediately after the evaporator detected by a duct sensor.

[Problems to be Solved by the Invention] As described above, the intake door is conventionally controlled irrespective of the capacity of the compressor. Therefore, for example, although the cooling capacity of the compressor tends to be insufficient, the intake door is controlled to increase the amount of outside air introduced, so that the evaporator temperature rises, or even though the compressor has sufficient surplus capacity, In some cases, the door was controlled to increase the amount of inside air introduced, resulting in insufficient ventilation.

[Means for Solving the Problems] In order to solve the above problems, the intake control device of the present invention adjusts the ratio of the outside air introduction amount and the inside air introduction amount by the opening degree of the intake door as shown in FIG. Inside and outside air introduction amount adjusting means 1, a duct sensor 2 for detecting the temperature of the air immediately after passing through the evaporator, a variable capacity compressor 3 forming a cooling cycle together with the evaporator, and a compressor for the compressor according to the detection value of the duct sensor. A compressor capacity control means 4 for controlling the capacity, further comprising: a means 5 for detecting the capacity of the compressor; and a control signal supplied to the inside / outside air introduction amount adjusting means 1 in accordance with the detection value of the means 5. And an intake door control means 6 which is provided.

Here, the intake door control means 6 in the first aspect of the present invention periodically compares the detection value of the compressor capacity detection means 5 with a preset reference value, and according to the comparison result, the intake door control means 6 has a small unit amount. The control signal for increasing or decreasing the opening is supplied to the inside / outside air introduction amount adjusting means 1.

[Operation] According to the device of the first aspect of the present invention, the intake door control means 6 compares the compressor capacity with the reference value,
The intake door opening is increased or decreased by a small unit amount according to the comparison result. Then, the temperature of the evaporator changes due to the change in the opening degree of the intake door, and the change is detected by the duct sensor. When the detection value of the duct sensor changes, the capacity of the compressor changes.

Then, by repeating this periodically, the intake door is controlled so that the inside and outside air introduction amount is optimized, and accordingly, the compressor capacity is controlled within a predetermined range determined by the reference value. Therefore, the optimal amount of outside air is introduced according to the surplus capacity of the compressor, and the temperature rise of the evaporator is avoided, and the ventilation is sufficiently performed.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

FIG. 2 shows a schematic configuration of an automotive air conditioner incorporating the intake control device of the embodiment. In this air conditioner, an inside air inlet 10A and an outside air inlet 10B are formed at the most upstream portion of the air conditioning duct 10, and by controlling the opening of the intake door 11, the inside air and outside air to be introduced into the air conditioning duct 10 are controlled. The ratio can be adjusted.

The air conditioning duct 10 includes a blower fan 12, an evaporator 13, an air mix door 14, and a heater 15
Is provided. The evaporator 13 is a compressor 1
6. The refrigeration cycle is constituted by piping connection with the condenser 17, the receiver tank 18, and the expansion valve 19.

As the compressor 16, a wobble plate type variable displacement compressor of the same type as that disclosed in JP-A-52-96407, JP-A-63-9682 and the like is used.

In the compressor 16, the capacity is determined by the inclination angle of the swash plate (oscillating plate), the inclination angle of the swash plate is determined by the pressure in the crank chamber, and the pressure in the crank chamber is determined by the actual opening of the solenoid valve. Decided. That is, when the supply current to the solenoid valve is increased, the compressor capacity is reduced, and when the supply current to the solenoid valve is reduced, the compressor capacity is increased. Therefore, in this compressor, the solenoid valve constitutes the capacity adjusting mechanism 16A.

The compressor 16 is provided with a stroke sensor 16B for detecting the inclination of the swash plate, and the current displacement can be known from the detected value of the stroke sensor 16B.

The variable displacement compressor 16 is driven by a force transmitted from the engine, and is driven and controlled by connecting and disconnecting an electromagnetic clutch (not shown).

The air mix door 14 adjusts the ratio of air passing through the heater 15 and air not passing through the heater 15 in accordance with the degree of opening. Then, the air that has passed through the heater 15 and the air that does not ventilate are mixed downstream of the heater 15 to adjust the temperature, and are blown into the vehicle from the outlet.

The rear end of the air conditioning duct 10 has a defrost outlet 21 for blowing air toward the inner surface of the windshield, a vent outlet 22 for blowing air toward the occupant's face, and a blower for blowing air toward the occupant's feet. An outlet 23 is provided in the vehicle interior, and each of the outlets 21, 22, 23 is provided with a mode door 24, 25, 26, respectively. And by selectively opening and closing these mode doors 24, 25, 26,
The blowing mode can be changed.

The above-described intake door 11, air mix door 14, and mode doors 24-26 are controlled to be opened and closed by actuators 27, 28, and 29, respectively. Each of these actuators 27-2
9, blower fan 12, compressor 16 capacity adjustment mechanism 16A,
The drive of each of the electromagnetic clutches is controlled by the control unit 50.

The control unit 50 includes the actuators 27
To 29, a blower fan 12, a capacity adjustment mechanism 16A, a drive circuit for driving an electromagnetic clutch and the like, a microcomputer for supplying a control signal to each drive circuit, an A / D converter connected to the microcomputer, And a multiplexer.

Then, the A /
The D converter includes a potentiometer 51 for detecting the degree of opening of the air mix door 14, a solar radiation sensor 52 for detecting the amount of solar radiation entering the vehicle interior, and an outdoor air temperature sensor for detecting the outdoor air temperature.
53 and an inside air temperature sensor 54 for detecting a representative temperature in the cabin
And a temperature setter 55 for setting the temperature in the vehicle cabin, and a duct sensor 56 for detecting the air temperature immediately after passing through the evaporator 13, so that the detection data from each sensor is input to the microcomputer. It has become.

Next, a control operation example of the microcomputer in the control unit 50 will be described.

Note that the air blowing control, the air mixing door control, and the mode door control are the same as those of the related art, and thus description thereof is omitted here.

The compressor control is the same as the conventional one, but briefly, the microcomputer is a duct sensor.
Based on the evaporator temperature detected by 56, a drive signal is supplied to the capacity adjusting means 16A to control the compressor capacity. That is, the compressor capacity is increased as the evaporator temperature is higher, and the compressor capacity is decreased as the evaporator temperature is lower.

 Next, the contents of the intake control will be described.

FIG. 3 is a flowchart of intake control shown as a first embodiment of the present invention. This control routine is repeatedly executed at regular intervals. When the process of this routine is started, various switch signals and sensor (outside air temperature sensor, stroke sensor) signals are input in a first step 101. Next, at step 102, it is determined whether or not the intake AUTO (mode for automatically controlling the intake door) is selected.

If intake AUTO is not selected, step
The determination at 102 is NO, the process proceeds to steps 103 and 104, and it is determined whether the manual switch is operated to “FRESH (introducing outside air)” or “REC (internal air circulation)”. Step 105 if operated
To control the intake door to the FRESH position. If the operation is "REC", the process proceeds to step 106, where the intake door is controlled to the REC position. If neither is the case, the determinations in steps 103 and 104 are both NO, and control returns to the main routine (not shown).

On the other hand, if intake AUTO is selected, the determination in step 102 is YES, and the blowout mode
DEF (defrost), fan switch (FAN S
Check if W) is ON and if the air conditioner switch (A / C SW) is ON.

When the blow mode is DEF, when the fan switch is OFF, and when the air conditioner switch is OFF, the process proceeds to step 105, and the intake door is controlled to the FRESH position.

Also, the blow mode is not DEF and the fan switch is set to O
If N and the air conditioner switch is ON, the process proceeds to step 110. In step 110, the outside air temperature
It is determined whether Ta is larger or smaller than a reference value having a predetermined hysteresis. That is, the reference value a on the descending side (for example, 18 ° C.) and the reference value b on the ascending side (for example,
22 ° C.) to determine which side is A or B.

If it is on the A side, since the outside air temperature is lower than the standard, the outside air is entirely introduced, so that the routine proceeds to step 105, where the intake door is controlled to the FRESH position. On the B side, since the outside air temperature is equal to or higher than the reference, the intermediate opening control of the intake door described below is performed.

That is, first, in step 111, the detection value 1 of the stroke sensor is read, and the process proceeds to the next step 112. The above step 112 is further divided into smaller steps as shown in FIG.
It is determined whether a ratio ST (hereinafter, referred to as a stroke ratio) to the maximum value of the stroke sensor detection value is larger or smaller than a reference value having a predetermined hysteresis. That is, the ST value is 90% of the descending reference value,
Judge which side is A or B for 95%.

If it is on the A side, the process proceeds to step 112-2, where the opening of the intake door is increased by β%. On the B side,
Proceeding to step 112-3, setting the opening of the intake door to α
% Decrease. It should be noted that the values of α% and β% are minute unit amounts, and are set to values of the opening adjustment minimum unit amount determined from the mechanism up to about 5%. The values of α and β may be different from each other, but may be equal. Then, after adjusting the intake door opening by α% and β%, the process returns to the main routine.

Since the intake control of this embodiment is executed periodically, the following operational effects can be obtained.

In one process, the intake door opening is increased or decreased by a small unit amount according to the capacity of the compressor (corresponding to the value detected by the stroke sensor). Then, the amount of outside air introduced changes due to a change in the opening degree of the intake door, so that the temperature of the evaporator changes, and the change is detected by the duct sensor. When the detection value of the duct sensor changes, the capacity of the compressor changes accordingly.

Therefore, in the next process, the intake door opening is readjusted based on the changed capacity. By repeating this, the optimal intake door opening degree according to the compressor capacity is determined. Accordingly, the compressor capacity is controlled to a predetermined range determined by the reference value, in this case, a range of 90% to 95% (corresponding to a stroke ratio).

For this reason, leaving little spare capacity of the compressor,
The amount of outside air introduced can be set to the maximum, and sufficient ventilation can be performed. Further, since the intake door is controlled in accordance with the compressor capacity, a rise in the temperature of the evaporator is avoided.

Next, an intake control operation according to a second embodiment of the present invention will be described. The control operation of this embodiment is performed in step 112 of FIG.
Is characterized in that step 112 in FIG. 5 is executed instead of. The other points are the same as those of the first embodiment, and the description is omitted.

The above step 112 'is further divided into smaller steps. First, in step 112'-1, it is determined whether or not the timer for determining the intake door opening adjustment cycle is cleared. If it has been cleared, the timer is started in step 112'-2, and 60 seconds are counted. Then, based on the determination in step 112'-3, the following processing is performed every 60 seconds.

That is, first, the timer is cleared (step 11).
2'-4) Then, step 112'-5 and step 112 '
At -6, the capacity ratio of the compressor is checked. What is the capacity ratio?
(Current capacity) / (maximum capacity), which corresponds to the stroke ratio described above. This capacity ratio can be replaced by the term “operating rate”.

Then, step 112'-5 and step 112'-6
To determine whether the current capacity ratio is 60% or more or 40% or less, and
In the above case, the process proceeds to step 112'-7, and the intake door is moved to the FRESH side by 5%. In addition, the capacity ratio is 40
If not, the process proceeds to step 112'-8, and the intake door is moved to the REC side by 5%. Also, 40% and 60%
In the case of, the process returns to the main routine without making any changes.

According to the intake control of the second embodiment, the intake door opening is adjusted in a cycle of 60 seconds. Then, as in the above embodiment, the optimum intake door opening is determined according to the compressor capacity. In addition, a predetermined range in which the compressor capacity is determined by the reference value, in this case, 40% to 60%
(Capacity ratio). For this reason, an optimal amount of outside air can be introduced while achieving power saving of the compressor. Further, since the intake door is controlled in accordance with the compressor capacity, an increase in the temperature of the evaporator is avoided.

In the above-described embodiment, the case where the wobble plate type variable displacement compressor is used is shown. However, the present invention can of course be applied to a case where another compressor, for example, a rotary type variable displacement compressor is used. .
However, in that case, it is necessary to change the structure of the capacitance detecting means accordingly.

[Effects of the Invention] As described above, according to the intake control device of the present invention, the intake door is controlled according to the capacity of the compressor. Therefore, the optimal amount of outside air is introduced according to the surplus capacity of the compressor, and the temperature rise of the evaporator is avoided, and the ventilation is sufficiently performed.

Further, since the compressor capacity is controlled within a predetermined range determined by the reference value, power-saving operation can be performed by setting the reference value. Driving can also be performed.

[Brief description of the drawings]

FIG. 1 is a block diagram showing the configuration of the present invention, FIG. 2 is a schematic diagram showing the configuration of one embodiment of the present invention, FIG. 3 is a flowchart showing the control contents of one embodiment of the present invention, FIG. Is the third
FIG. 5 is a flowchart showing the detailed contents of step 112 of the flowchart shown in FIG. 5, and FIG. 5 is a flowchart showing the control contents of another embodiment. DESCRIPTION OF SYMBOLS 1 ... Inside and outside air introduction amount adjustment means 2 ... Duct sensor 3 ... Variable capacity compressor 4 ... Compressor capacity control means 5 ... Compressor capacity detection means 6 ... Intake door control means 10A ... Inside air inlet, 10B ... Outside air inlet 11 Intake door 13 Evaporator 16 Variable capacity compressor 16A Capacity adjustment mechanism 16B Stroke sensor (capacity detection means) 27 Intake door actuator 50 Control unit 56 Duct sensor

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int.Cl. ⁶ , DB name) B60H 1/00 B60H 1/32

Claims (1)

(57) [Claims] 1. An inside / outside air introduction amount adjusting means for adjusting a ratio between an outside air introduction amount and an inside air introduction amount according to an opening degree of an intake door.
It has a duct sensor for detecting the temperature of the air immediately after passing through the evaporator, a variable capacity compressor which forms a cooling cycle together with the evaporator, and a compressor capacity control means for controlling the capacity of the compressor according to the detection value of the duct sensor. In the air conditioner for a vehicle, a means for detecting the capacity of the compressor and a detection value of the means are periodically compared with a preset reference value, and the intake door opening is increased or decreased by a small unit amount according to the comparison result. An intake door control means for supplying a control signal to be supplied to the inside / outside air introduction amount adjusting means.