JPS6345364Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a control device for a vehicle air conditioner, and particularly to a control device aimed at saving energy in an automatic air conditioner.

In recent years, automatic air conditioning systems (hereinafter referred to as automatic air conditioners) that automate the control of vehicle air conditioners have been increasingly installed. A block diagram of such an automatic air conditioner is shown in FIG. The temperature of this system is controlled by cooling air sucked in by a fan 10 with an evaporator 1, heating it with a heater 2, and blowing it out into the vehicle interior. The blowing temperature at this time is controlled by adjusting the opening degree of the air mix damper 3.
The control is based on temperature setpoint, vehicle interior temperature, duct temperature,
This is done by processing the value of the amount of solar radiation in the control unit 4. Here, the temperature setting value is set by a temperature setting resistor 5, the vehicle interior temperature is detected by a room temperature sensor 6, and the amount of solar radiation is detected by a solar radiation sensor 7. FIGS. 2A to 2D show the state of each part relative to the heating and cooling load.

In the curve of the temperature of the air blown into the vehicle interior shown in FIG. It shows the energy loss area.

As can be seen from the figure, in conventional automatic air conditioners, the temperature of the air blown out from the evaporator 1 is always kept constant, and then the air mix damper 3 is adjusted (that is, the mixing ratio of cold air and hot air that passes through the heater 2 is adjusted). The temperature is controlled. Therefore, from the point of view of energy conservation, which has become a hot topic of discussion in recent years due to the high price of gasoline, conventional automatic air conditioners that control temperature by reheating the air cooled by the evaporator 1 using the heater 2 are considered to be contrary to energy conservation. It turns out.

In addition, in the conventional automatic air conditioner control device, the blower changeover switch 8 and the damper actuator for cooling/heating control are directly connected and controlled.
Compressa 9 even in spring and autumn when the cooling load is low
It has been difficult to effectively realize energy-saving operation because the motor must be operated at all times.

This invention was proposed in view of the above points,
The air mix damper is operated by a heat load command value generation circuit that outputs a heat load command value, which is made up of at least a vehicle interior temperature sensor, and an air mix damper opening feedback amount generation circuit that is made of a potentiometer that is linked to the air mix damper. In the air mix damper actuator control circuit that controls
A fixed resistor is connected in parallel to the potentiometer, which can be disconnected or disconnected in response to a switching means that can switch between energy-saving operation mode and dehumidification mode, and in the energy-saving operation mode, the fixed resistor is connected. Then, set the air mix damper to be fully closed at the position where the above heat load command value corresponds to approximately the midpoint of cooling/heating, and input the above heat load command value so that the heat load command value corresponds to approximately the midpoint of the above. In the area larger than the dehumidifying operation mode, the temperature is adjusted by changing the duty ratio of the compressor on and off using the compressor ON and OFF control circuit that outputs the compressor ON and OFF signals, which is composed of the evaporator outlet air temperature sensor. A vehicle air conditioner characterized in that the fixed resistor is cut off, the input of a heat load command value is cut off by a dehumidification control circuit linked to the switching means, and the compressor is always turned on by a compressor ON/OFF control circuit. control device. The purpose is to provide a control device for a vehicle air conditioner that can suppress unnecessary compressor operation and realize energy savings.

Hereinafter, the present invention will be explained based on illustrated embodiments.

Figure 3 is a circuit diagram of the control device, where 21 is a constant voltage generation circuit, 22 is a thermal load command value generation circuit, 23 is an air mix damper opening feedback amount generation circuit, and 24 is an air mix damper actuator control. 25 is a blower control circuit, 26 is a compressor ON/OFF control circuit, and 27 is a dehumidification control circuit.

The thermal load command value generation circuit 22 is a fixed resistance (RI)
28, temperature setting variable resistor (VRS) 29, vehicle interior temperature sensor (Rr) 30, vehicle exterior temperature sensor (Rφ) 31, and solar radiation sensor (SS) 32 and fixed resistor (R2) 33 arranged in parallel are arranged in series, and a potential (unit: volt) is generated at point a as follows: V=A−B・VRS+C・Rr+D・Rφ+E・SS (1). Here, A, B, C, D, and E are appropriately determined constants.

The potential generated at point a is further impedance-converted by the buffer (IC1) 34, and
The potential at point b, which is the same potential as point b, is given, and this potential at point b is referred to as a command value.

The air mix damper opening feedback amount generation circuit 23 includes a potentiometer (VRP) 35 interlocked with the air mix damper 51, fixed resistors (R4) 37, (R5) 38, and (R6) 39 arranged in series. Furthermore, a fixed resistor (R3) 36 is connected in parallel with the potentiometer (VRP) 35 or disconnected as the relay contact (RYD) 103a of the dry relay (RYD) 103, which will be described later, is turned on and off. It is arranged so that it can be used.

The dry relay contact 103a is ON during energy saving operation and OFF during dehumidification operation, and the relationship between the air mix damper opening degree and the combined resistance between points c and d is as follows.
The result will be as shown in the figure.

In other words, the resistance Rc~ between points c and d during dehumidification operation
d・D is Rc~d・D=VRP...(2) Resistance between points c and d during energy saving operation Rc _~ d・E is Rc~d・E=VRP×R3/VRP+R3...(3) becomes.

Here, the resistance or combined resistance at point A shown in Figure 5, that is, the resistance on the MAXHOT side, should be almost the same value during dehumidification operation and energy saving operation, and the combined resistance at point C should be the same value during dehumidification operation. Fixed resistor (R3) 36 so that it is about 60% of the resistance fluctuation.
is determined appropriately. Furthermore, the potential at point a or b given by the equation (1) above, that is, the command value, which varies within a predetermined control range shown in FIG. It operates to have almost the same value as the potential at point d, which fluctuates due to resistance changes, but from the viewpoint of comfortable temperature control, potentiometer (VRP) 3
5 resistance characteristics and fixed resistance (R4) 37, (R5)
The resistance values of 38 and (R6) 39 are appropriately determined.

Air mix damper actuator control circuit 2
4 is composed of comparators (IC2) 40, (IC3) 41, transistors 42 to 49, air mix damper actuator motor 50, air mix damper 51, feedback potentiometer (VRP) 35, etc. and point b and point d or b
The air mix damper opening degree changes due to the potential difference between point and e, and the resistance of potentiometer (VRP) 35 linked to this moves in the direction of reducing the potential difference between point b and point d or point b and point e. . Here, the fixed resistor (R5) 38 is the comparator (IC2) 40,
(IC3) It is a dead zone where both 41 are OFF,
The fixed resistors 52 and 53 provide hysteresis for the comparators 40 and 41, and are appropriately determined in order to obtain comfortable temperature control.

Also, during dehumidification operation, the contact 103a of the dry relay 103 is in the open state, and the relationship between the command value and the air mix damper opening at this time is as shown by the dotted line in Figure 4B. As shown, potentiometer (VRP) 35 and fixed resistor (R3)
36 are connected in parallel, the potentials at points d and e rise, and the comparator (IC3) 41
ON, (IC2) 40 turns OFF, air mix damper 51 and potentiometer (VRP) 35 turn off.
It moves to the COOL side and stops when the potentials at points d and e approach the potential at point b. The fixed resistor (R3) 36 is arranged in parallel so that the amount of variation with respect to the command value to the COOL side of the air mix damper 51 due to the parallel resistance arrangement of the fixed resistor (R3) 36 is near point A in FIG. 4B. The value is determined appropriately.

The blower control circuit 25 is a comparator (IC4) 5
4, minus side of (IC5) 55, (IC6) 56, comparison calculator (IC7) 57, (IC8) 58, (IC9) 59
The command value is on the plus side of
Fixed resistance 60, 61, 6 on the positive side of 5, 56
2, the potential divided by 63, the comparison calculator 5
Fixed resistance 64, 6 on the negative side of 7, 58, 59
The divided potentials are added at 5, 66, and 67, and the result of the comparison operation is sent to the subsequent transistor 68.
73 to 74 to 79, and fixed resistors 83 to 8 arranged in series with the blower via power relays (RY1) 80, (RY2) 81, (RY3) 82, etc.
5 to power relay contacts 80a, 81a, 8, respectively.
fan motor 8 by shorting through 2a
By switching the voltage to 6, the air volume can be increased or decreased in stages. Here, the comparison calculators 54, 5
5 and 56 are heating area switching and comparison calculators 57 and 5.
8 and 59 are used to switch the cooling area, and the resistance values of fixed resistors 60 to 63 and 64 to 67 are determined appropriately from the viewpoint of temperature control, but they are designed to have the characteristics as shown in Fig. 4A. It's getting old.

The compressor ON/OFF control circuit 26 corresponds to the potential at point g, which is divided by the evaporator air temperature sensor (RE) 87 and fixed resistors 88 and 89 arranged in series with it, that is, the evaporator air temperature. The potential is compared to the comparator (IC10) 9
On the other hand, since the command value is given from the negative side, the comparator 90 turns on and off depending on the magnitude of the command value potential.
The potential at point g required to do this is designed to fluctuate. The relationship between the command value and the evaporator air temperature when the transistor (TR1) 94 is ON is shown in the loss region during energy-saving operation in FIG. 4C. Furthermore, the potential at point g is also input to the negative side of the comparator (IC11) 91, and is compared with the voltage divided by the fixed resistors 92 and 93, and the transistor (TR2)
When 95 is ON, the relationship between the temperatures of the evaporator air blown out is as shown in area C during dehumidification operation and energy saving operation in Figure 4C. Note that the comparison calculator 91
Evaporator outlet temperature sensor 8 by ON/OFF
The average temperature of 7 corresponds to the antifreeze temperature of the evaporator. In addition, transistors 94 and 95 have an AND configuration, and the air conditioner switch (A/C
When S/W) 98 is ON, transistor 96,
97, compressor (COMP) 10 via power relay ((RYM) 99 and its contact 99a
By turning on and off 0, the cooling action by the evaporator 101 is turned on and off.
An evaporator blown air temperature sensor 87 placed at the outlet detects the blown air temperature, and turns the compressor on and off repeatedly so that the potential at point g becomes the same potential as the potential at point f on average. .

In the case of energy-saving operation, the air mix damper 51 is fully closed (MAXCOOL) in the cooling load range as shown in Figure 4B, so the temperature control as an automatic air conditioner is performed according to the command value as described above. This is done by creating an evaporator outlet air temperature, and a fixed resistor 8 to create this relationship.
8 and 89 are appropriately determined.

In the dehumidification control circuit 27, the dry relay (RYD) 103 is excited when the dry switch (DS/w) 102 is turned ON during dehumidification operation, and the potentiometer of the fixed resistor (R3) 36 is excited when the relay contact 103a is turned OFF as described above. The parallel connection to the meter (VRP) 35 is released and the transistor (TR3) 104
turns on and plays the role of grounding point f. f
By grounding the point, the comparator 90 is always ON, and the ON/OFF of the compressor 100 is controlled by the comparator 9.
It will be carried out depending only on 1. In other words, the function is to simply prevent the evaporator 101 from freezing without changing the temperature of the air blown out from the evaporator in accordance with the command value as in the case of energy-saving operation.

Next, the effect will be explained.

In this embodiment, when a certain indoor temperature setting value is given, the system finally matches the heat load and the heating and cooling capacity, and operates to make the indoor temperature match the set temperature.

First, a desired vehicle interior temperature is set using the temperature setting variable resistor 29. Then, a vehicle interior temperature sensor 30, a vehicle exterior temperature sensor 31, and a solar radiation sensor 32
From each temperature and amount of solar radiation detected in (1) above, the potential at point a, that is, the potential at point b is given as a command value. This command value V fluctuates from V to V ₀ as shown in Fig. 4D, and when V = 0, the maximum heating is reached.
Maximum cooling occurs when V=V ₀ . Then, as described above, a fan voltage as shown in FIG. 4A is applied to the fan motor 86 via the blower control circuit 25, and the fan motor 86 is driven so that the air volume increases step by step in areas with large cooling and heating loads. do.

Further, the above command value is input to the air mix damper actuator control circuit 24, and the air mix damper 51 is driven as described above, and as a result,
As shown in FIG. 4B, the opening degree of the air mix damper 51 is controlled during a cooling load or a heating load. Here, the dry switch 102
During energy-saving operation in which the air mix damper 51 is OFF, the opening degree of the air mix damper 51 is at the MAXCOOL position when the command value V is approximately 0.6×V ₀ as described above.

Furthermore, the above command value is for compressor ON/OFF.
It is input to the control circuit 26 and the air conditioner switch 98
is ON, turns compressor 100 ON/OFF
Control. That is, the dry switch 102
During energy-saving operation, which is OFF, the compressor 100 is repeatedly turned ON and OFF so that the potential at point g becomes the same as the potential at point f, as described above.
As shown in Figure B, in the cooling load region, the air mix damper 51 is fully closed (MAXCOOL), so by turning the compressor 100 on and off, the evaporator blows out according to the command value as shown in Figure 4C. By creating air temperature, the temperature is controlled as an automatic air conditioner, and on the other hand, during dehumidification operation when the dry switch 102 is turned on, the evaporator blown air temperature is varied in response to the command value, like during energy-saving operation. As with the conventional one, the compressor is connected to the comparator 91 as described above.
The evaporator is operated while preventing freezing of the evaporator, and the temperature is controlled by keeping the air blown from the evaporator constant and controlling the opening degree of the air mix damper 51.

As described above, it is possible to switch between energy-saving operation and dehumidification operation, and temperature control during energy-saving operation is performed by controlling the temperature of the air blown from the evaporator by turning the compressor on and off, without using the air mix damper. Because of this, unnecessary compressor operation can be suppressed, thereby realizing energy savings. Furthermore, in areas with large heating and cooling loads, the air volume from the fan is increased in stages, allowing for comfortable temperature control that corresponds to the load.

[Brief explanation of the drawing]

Fig. 1 is a configuration diagram of a conventional air conditioner, Fig. 2 A to D are its sequence diagram, Fig. 3 is a control circuit diagram showing an embodiment of the present invention, Fig. 4 A to D are its sequence diagram, and Fig. 4 is a sequence diagram of the conventional air conditioner. FIG. 5 is a diagram showing the relationship between the air mix damper opening degree and the potentiometer combined resistance. 21... Constant voltage generation circuit, 22... Thermal load command value generation circuit, 23... Air mix damper opening feedback amount generation circuit, 24... Air mix damper actuator control circuit, 25... Blower control Circuit, 26... Compressor ON/OFF control circuit, 27... Dehumidification control circuit, 35... Potentiometer, 36... Fixed resistor, 51... Air mix damper, 86... Fan motor, 100...
Compressor, 102...Dry switch, 10
3...Dry relay, 103a...Dry relay contact.

Claims (1)

[Scope of utility model registration request] The air mix damper is operated by a heat load command value generation circuit that outputs a heat load command value, which is made up of at least a vehicle interior temperature sensor, and an air mix damper opening feedback amount generation circuit that is made of a potentiometer that is linked to the air mix damper. In the air mix damper actuator control circuit which controls Connect the wires,
In the above energy saving operation mode, the above fixed resistor is connected and the air mix damper is fully closed at a position where the above heat load command value corresponds to approximately the midpoint of cooling/heating, and the above heat load command value is input. In a region where the heat load command value is larger than the position corresponding to the approximate midpoint above, the compressor ON/OFF duty ratio is changed by the compressor ON/OFF control circuit that outputs the compressor ON/OFF signal, which is comprised of an evaporator outlet air temperature sensor. In the dehumidifying operation mode, the fixed resistor is cut off, the input of the heat load command value is cut off by the dehumidifying control circuit linked to the switching means, and the compressor is always turned on by the compressor ON/OFF control circuit. A control device for a vehicle air conditioner, characterized in that: