JPH03143720A - Air conditioning device for vehicle - Google Patents

Abstract

PURPOSE:To improve comfortableness with a noise suppressed without fixing a fan speed by controlling the blower fan speed at the time of a fuel saving auto-mode to a lower speed from at the time of a normal auto-mode, when a vehicle thermal load is in not less than a predetermined value. CONSTITUTION:Any of a normal auto-mode and a fuel saving auto-mode is commanded by a means 103 so as to control a blower fan 101 and a compressor 102, which press-feeds a refrigerant, in accordance with a vehicle thermal load. While a speed of the blower fan 101 is commanded by a means 104. Further when any of the above described auto-modes is commanded, the blower fan 101 is drive-controlled by a means 105 in accordance with the vehicle thermal load and a command from the means 104. Operation of the compressor 102 is controlled by a means 106 in such a manner that an engine load for the compressor 102 is reduced at the time of a command of the fuel saving auto- mode smaller than at the time of a command of the normal auto-mode.

Description

DETAILED DESCRIPTION OF THE INVENTION A. Field of Industrial Application The present invention relates to a vehicle air conditioner in which a normal auto mode and a fuel saving auto mode can be selected.

In a conventional vehicle air conditioner capable of automatic mode control, the blower fan and compressor are controlled in accordance with the vehicle heat load when in automatic mode. In other words, the applied voltage to be applied to the blower fan is determined according to the vehicle heat load, and the speed of the blower fan is controlled thereby to control the air volume, and the compressor is turned on/off or the discharge capacity is controlled depending on this heat load. control.

In addition, some air conditioners allow you to select between normal auto mode and fuel saving auto mode. (For example, 1 Nissan Motor Co., Ltd., "Service Weekly" No. 578, June 1988) 6 Problems to be Solved by the C1 Invention By the way, as the speed of the blower fan increases, the noise also increases. Especially when the air volume is at its maximum, the loud noise can cause problems such as difficulty in having a conversation or hearing audio.

Therefore, 1. For example, if the fan speed is reduced by operating the air volume selector switch (instruction means) in hand a, the noise can be reduced, but in this case, the air volume is fixed at a constant value, so the above-mentioned vehicle heat load Even under conditions where the air volume can be further reduced, the air volume cannot be reduced further, and there is a risk that comfort may be impaired.

A technical problem of the present invention is to reduce the noise of a blower fan without fixing the air volume.

00 Means for Solving the Problems To explain with reference to FIG. 1, which is a diagram corresponding to the claims, the present invention includes a blower fan 101, a compressor 102 that pumps refrigerant, and a system that operates the blower fan 101 and the compressor 102 according to the vehicle heat load. A command means 103 commands either the normal auto mode or the fuel saving auto mode to be controlled, and a command means 104 commands the speed of the blower fan 101. When either of the above auto modes is commanded, the vehicle Blower fan 1 depending on heat load
01 and drives the blower fan 101 at a speed according to the instruction from the instruction means 104. When the fuel saving auto mode is instructed, the normal auto mode is instructed. The present invention is applied to a vehicle air conditioner including a compressor control means 106 that operates the compressor 102 so that the engine load on the compressor 102 is reduced compared to when the compressor 102 is not in use. The fan control means 105 is configured as follows, thereby solving the above technical problem.

That is, when the vehicle thermal load is greater than or equal to a predetermined value, the blower fan speed when the fuel saving auto mode is commanded is set lower than when the normal auto mode is commanded.

When the vehicle thermal load is equal to or greater than a predetermined value, the E0 effect fan control means 105 sets the blower fan speed at the time of the fuel saving auto mode command to be lower than that at the time of the normal auto mode command. Therefore, by instructing the fuel saving auto mode, it is possible to reduce the noise caused by the high speed rotation of the blower fan without fixing the amount of air blown.

F. Example An embodiment of the present invention will be described with reference to FIGS. 2 to 6.

As shown in FIG. 2, the vehicle air conditioner according to the present invention has the following features:
Variable displacement compressor 2 driven by engine 1
．． Capacitor 3. Evaporator 4° liquid tank 5.
A compression refrigeration cycle cooler unit 100 including an expansion valve 6 is provided.

The variable displacement compressor 2 increases the displacement by increasing the inclination angle when the suction pressure exceeds the set pressure.The set pressure is determined by the solenoid current rSQL supplied from the control circuit 30 shown in FIG. controlled by

Further, the evaporator 4 is disposed within an air conditioning duct 7 having an outside air introduction lower a and an inside air introduction lower b.

Each of the introduction lowers a, 7b is provided with an inside/outside air switching door 8 that controls the flow rate of air introduced into the air conditioning duct 7. Furthermore, inside the air conditioning duct 7, there is a well-known rib blower fan 9,
A heater unit 1o and an air mix door 11 are provided, as well as a vent door 12 and a foot door 13 for adjusting the amount of air blowing from a vent blowing lower c and a foot blowing lower d provided in the air conditioning duct 7, respectively.

Furthermore, a defroster blowout lower e provided in the air conditioning duct 7
A defroster door 14 is provided.

FIG. 3 shows a control system, and the control circuit 30 consists of a CPU 31, an input circuit 32 and an output circuit 33 connected to the CPU 31. The input circuit 32 receives the outside air temperature T AM
An outside temperature sensor 41° that detects B; an indoor temperature sensor 42 that detects the vehicle interior temperature TINC; a solar radiation sensor 43 that detects solar radiation 1Qsus; a suction temperature sensor that detects the air temperature downstream of the evaporator 4 (hereinafter referred to as suction temperature) TINT. 44 are connected to each other, and these sensors 41 to 44
Various temperature information and heat amount information (vehicle heat load) are input to the CPU 31 via the input circuit 32.

The input circuit 32 also includes an economy switch 21. installed in the driver's seat. An air conditioner switch 22, an air volume changeover switch 23, and an air outlet selection switch 24 are connected. The economy switch 21 is a switch for setting a fuel-saving auto mode, which will be described later, and the air conditioner switch 22 is a switch for setting a normal auto mode. The air volume selection switch 23 is a switch that is operated to set the air volume of the blower fan to a desired amount, and the air outlet selection switch 24 is a switch that is operated to select an air outlet.

Further, a blower fan control circuit 51 is connected to the CPU 31 via an output circuit 33.
1 is connected to the above-mentioned blower fan motor 9.

Further, the compressor 2 is connected to the output circuit 33 via a relay 52.

The CPU 31 controls each sensor 41 to 44 and each switch 21 to
Based on various information inputted from 24, the air inlet, outlet and outlet temperature or the capacity of the compressor 2 are appropriately controlled.

The blower fan motor 9 is driven and controlled via the blower fan control circuit 51.

Next, the operation of the embodiment will be explained.

FIG. 4 is a flowchart showing the basic control of the air conditioning control device executed by the CPU 31.

In step SIO, initial settings are performed, and in auto mode, for example, the set temperature TPTc is initially set to 25°C. In step S20, various information from each sensor is input.

To specifically explain the data information of each of these sensors,
The set temperature TPTc is obtained from the control panel 42 (not shown), the outside air temperature TAMB is obtained from the outside air temperature sensor 41, the suction temperature TINT is obtained from the suction temperature sensor 44, and the amount of solar radiation Q! 3LIN is given from the solar radiation sensor 43.

Next, in step S30, the outside air temperature TAMB obtained from the outside air temperature sensor 41 is processed to a value TAM corresponding to the actual outside air temperature by removing the influence from other heat sources. Next, in step S40, the solar radiation amount information as the light amount from the solar radiation sensor 43 is converted into a value Q's as a heat amount suitable for subsequent conversion.
Process to υN.

In step S50, a value T' is obtained by correcting the set temperature TPTC set on the control panel according to the outside temperature.
Process to PTC. In step S60.

Using T'prc+ T INc+ TAMI Q'suN, To=(A+D)T'pTc+B-TAMIC
-Q'5uN-D-TIN(:+E (however, A to E are constants) to calculate the target blowout temperature To, and adjust the air mix door 11 according to the deviation between the target blowout temperature To and the actual blowout temperature. Calculate the opening degree.

In step S70, the compressor 2 is controlled.

In step S80, each outlet is controlled. Step S9
0 controls selection switching of the suction ports, that is, the outside air introduction lower a and the inside air introduction lower b. In step 5100, the blower fan 9 is controlled to control the air volume from the outlet. After step 5100, step S10
Return to and repeat the above process.

FIG. 5(a) shows the compressor control in step 570 (FIG. 4).

In FIG. 5(a), in step 5701, it is determined whether or not the air conditioner switch 22 is on, that is, whether the normal auto mode is set. If it is on, in step 5702, normal compressor control ( (detailed explanation is omitted). If the air conditioner switch 22 is off, it is determined in step 5703 whether the economy switch 21 is on, that is, whether the fuel saving auto mode is set. If the economy switch 21 is off, the compressor 2 is stopped in step 5704;
If it is on, fuel saving auto mode control from step 8705 onwards is performed.

That is, first in step 5705, it is determined whether the air outlet is in pie level (B/L) mode. Here, B
/L mode is a mode in which air is blown out from both the vent blowout lower c and the foot blowout lower d. If the mode is B/L mode, the process proceeds to step 5706, and if not the B/L mode, the process proceeds to step 5707. Steps 5706 and 57
In step 07, the target suction temperature T'lNT is determined from the target outlet temperature 'ro according to the graph in FIG. 5(b).

That is, in B/L mode, the target suction temperature T'lNT is set according to the characteristic diagram ■, and in modes other than B/L mode, the target suction temperature T'lNT is set according to the characteristic diagram I.
Set T.

Next, the process proceeds to step 8708, and it is determined whether the suction temperature TINT is in state 6 or 7 depending on which of the temperature ranges defined by the freezing start temperature T4 and the temperature T, which is a slightly lower temperature. Step 5
In step 709, it is determined whether or not the state is 7. If the answer is yes, that is, if the state is 7, the compressor is turned off in step 5710 and the process returns to the predetermined process. On the other hand, if it is determined that the state is 6, in step 5711, the solenoid current value ISQL is controlled based on the difference between the suction temperature T rur and the target suction temperature T″[NT, and the process returns to the predetermined process. The capacity of the compressor is controlled according to SQL.

According to the above procedure, the compressor 2 is extremely finely controlled so that the suction temperature TINT corresponds to the target outlet temperature To, resulting in fuel savings for the following reasons.

Power saving is achieved.

As in conventional control, when the opening degree of the air mix door 11 is adjusted based on the deviation between the current suction temperature T TNT and the target blow-off temperature To to obtain the desired blow-out temperature, the suction temperature T INT changes depending on the operating state. may become undesirably too low, and in this case, the air mix door 11 is slightly opened to control the blowing temperature to the target value. For this reason,
The compressor wastes power and has a negative impact on fuel efficiency.

According to the above-mentioned fuel-saving auto mode control, for a certain target blowout temperature To, it is determined by experimental values how much the air temperature downstream of the evaporator 4, that is, the suction temperature TINT, should be set in order to obtain that temperature. The target blowout temperature ' is calculated according to the graph in FIG. 5(b).
A target suction temperature T'lNT is determined from ro, and the discharge capacity of the compressor is controlled using this target suction temperature T'lNT to prevent the suction temperature TINT from dropping too much. That is, the engine load on the compressor is reduced compared to when the compressor is in a normal auto mode, and therefore the absorbed horsepower is also reduced, contributing to power saving and fuel saving.

FIG. 6 is a flowchart showing details of fan control (step 5100 in FIG. 4).

First, in step 5IOI, it is determined whether a stop switch (not shown) is on, and if it is on, step 5102
Stop the blower fan 9, and if it is off, step 51
At step 03, it is determined whether the air volume changeover switch 23 is being operated. If step 5103 is affirmative, then in step 5104 a voltage V corresponding to the operation of this switch 23 is applied to the blower fan motor 9, and the blower fan motor 9 is driven at a speed corresponding to the applied voltage (■). Step 51
If 03 is denied, in step 5105 the target blowout temperature TO (step S in FIG. 4) is determined based on the characteristics shown in FIG.
Step 8106 is then performed to determine the fan applied voltage V corresponding to the value calculated in step 60).

In step 8106, it is determined whether the economy switch 21 is on (whether the fuel saving auto mode is set or not), and if it is off, the process proceeds to step 5ilo. Here, the fact that step 5106 is negative means that the normal auto mode is set. In step 5Lio, the voltage V determined in step 5105 is applied to the blower fan motor 9 to drive it. As a result, the blower fan motor 9 is driven at a speed corresponding to the voltage V, and air is blown out at a corresponding amount.

-4: If it is determined in step 8106 that the economy switch 21 is on, the process proceeds to step 51o7, where it is determined whether the defroster outlet is selected by the outlet selection switch 24, that is, whether or not the mode is in the defroster mode. If it is on, it is determined that it is in the differential mode and the process proceeds to step 5il.
If it is off, it is determined that the differential mode is not present, and in step 5108, it is determined whether the voltage V obtained in step 5105 is equal to or higher than a predetermined value 71.

Here, this predetermined value v1 is a value lower than the selectable maximum voltage V MAX as shown in the above-mentioned characteristics. If step 3108 is negative, the process proceeds to step 5tto; if affirmative, V=Vl is set in step 5109, and the process proceeds to step 3110.

According to the above procedure, when the fuel saving auto mode is selected by turning on the economy switch 21 and the differential mode is not selected, the fan applied voltage V is
1 or less, and the speed of the blower fan is kept below a predetermined value. That is, when the target blowout temperature To shown in step 5105 is equal to or higher than the predetermined value To1, the blower fan speed in the fuel saving auto mode is lower than that in the normal auto mode, and the noise generated by driving the blower fan is suppressed. be done. Therefore, unlike conventional devices, problems such as difficulty in conversation or difficulty in hearing audio due to loud noises do not occur.

Also, unlike the case where the air volume is reduced by operating the manual air volume selector switch 23, the air volume is not fixed, and if the target blowing temperature To is equal to or higher than the predetermined value To□, it is the same as the normal auto mode. Since the air volume is controlled, comfort will not be compromised.

Further, when the differential mode is selected, priority is given to defogging the window glass, and vl is not set.

In the configuration of the above embodiment, the economy switch 21
The air conditioner switch 22 constitutes a command means 103, the air volume changeover switch 23 constitutes a command means 104, the CPU 31 and the blower fan control circuit 51 constitute a fan control means 105, and the CPU 31 constitutes a compressor control means 106.

Further, FIG. 7 shows a modification of the process, in which step 5111 is added between steps 5107 and 8108 in FIG.

That is, in the process shown in FIG. 6, v1 is set to a predetermined constant value, but in this example, v1 is determined according to the correction value TAM of the outside air temperature.

Specifically, when the outside air temperature is higher than a predetermined value, the higher the outside air temperature is, the larger the value of vl is, and the fan speed is increased. According to this, comfort at high temperatures is not impaired.

Note that the control during the fuel saving auto mode is not limited to the above-mentioned one. For example, in the above-mentioned control to turn off the compressor when the suction temperature falls below a predetermined temperature, the control in the fuel saving auto mode is more effective than in the normal auto mode. The above-mentioned predetermined temperature may be set relatively high.

G0 Effect of the invention According to the invention, when the vehicle heat load is equal to or higher than a predetermined value,
Since the blower fan speed in the fuel saving auto mode is set lower than in the normal auto mode, noise can be suppressed without fixing the fan speed. However,
By selecting the fuel-saving auto mode, you can eliminate the conventional inconveniences such as loud noises that make it difficult to listen to music or hear the audio, and even when the vehicle heat load is low, the air volume can be appropriately controlled, making it more comfortable. There is no loss of sexuality.

[Brief explanation of the drawing]

FIG. 1 is a complaint correspondence diagram. 2 to 6 show an embodiment of the present invention. FIG. 2 is an overall configuration diagram, FIG. 3 is a block diagram of a control system, and FIG. 4 is a basic flowchart 1-1. ) is a flowchart of compressor control, FIG. 5(b) is a characteristic diagram for determining the target suction temperature from the target outlet temperature, FIG. 6 is a flowchart of fan control, and FIG. 7 is a flowchart showing a modification of fan control. be. 2: Compressor 9 Ni blower fan 21: Economy switch 23: Air volume selection switch 3o: Control circuit 31: CP
U 51 Niblower fan control circuit 101 Niblower fan 102: Compressor 1o3: Command means
104: Instruction means 105: Fan control means 106: Compressor control means

Claims (1)

[Scope of Claims] A blower fan, a compressor that pumps refrigerant, and a command means that commands either a normal auto mode or a fuel-saving auto mode to control the blower fan and compressor according to the vehicle heat load; an instruction means for instructing the speed of the blower fan; and when one of the auto modes is instructed, the speed of the blower fan is controlled according to the vehicle heat load, and at a speed according to the instruction from the instruction means; a fan control means for driving the blower fan; and when the fuel saving auto mode is instructed, the compressor is operated so that an engine load on the compressor is reduced compared to when the normal auto mode is instructed. In the vehicle air conditioner comprising a compressor control means, when the vehicle heat load is equal to or higher than a predetermined value, the fan control means changes the blower fan speed during the fuel saving auto mode command to the normal auto mode command. A vehicle air conditioner characterized by a lower speed than the vehicle air conditioner.