JP3141620B2 - Vehicle air conditioner - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an air conditioner for a vehicle having a variable displacement compressor connected to a driving source for driving the vehicle.

[0002]

2. Description of the Related Art In recent years, electric vehicles using a motor as a drive source for running a vehicle have been provided. The air conditioner of this electric vehicle is configured so that a compressor for a refrigeration cycle is directly connected to a motor as a driving source for traveling.
The compressor is rotated and driven according to the rotation of the motor. Therefore, when the electric vehicle is operated at a high speed, the compressor is also driven at a high speed, so that the cooling capacity becomes more than necessary, and a large power consumption is required for driving the compressor. Becomes extremely large.

[0003] On the other hand, in a vehicle equipped with an engine having a small displacement as a driving source, when a compressor is directly connected to the engine for air conditioning, a part of the driving force of the engine is consumed for driving the compressor. As a result, the engine output is reduced and the driving capability is reduced.

In order to solve these drawbacks, a regulator is provided between the compressor and the driving source so that the rotation of the compressor does not increase more than a set number of rotations even if the rotation of the driving source increases. However, in such a configuration, the regulator is complicated and the cost is greatly increased.

[0005] On the other hand, like an air conditioner for a vehicle shown in Nippon Denso Publication Technical Report No. 70-020,
It has been proposed to provide a variable displacement compressor and drive the variable displacement compressor rotating at the same speed as the engine in a small capacity, low capacity operation when the engine speed reaches a set speed. According to this, power saving operation can be realized with a simple configuration.

[0006]

However, in the above-mentioned conventional construction, the rotational speed at which the variable displacement compressor switches to the small capacity, low capacity operation is fixed, so that the power saving operation is smaller than the cooling capacity of the compressor. However, there is a disadvantage that power saving operation cannot be realized unless the rotation speed of the drive source reaches the set rotation speed even when priority is given to

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and has as its object to provide a vehicle for which power saving operation can be arbitrarily executed in a configuration in which power saving operation is performed by using a variable displacement compressor. An object of the present invention is to provide an air conditioner.

[0008]

SUMMARY OF THE INVENTION The present invention provides a variable displacement compressor for a refrigeration cycle which is provided so as to be connectable to a driving source for a vehicle and is capable of switching from a rated capacity operation to a small capacity low capacity operation. A vehicle air conditioner comprising: a detection unit for detecting a physical quantity corresponding to the number of revolutions of the vehicle; and a control device for switching the compressor from a rated capacity operation to a low capacity operation when the physical quantity detected by the detection means exceeds a set value. In the device, the vehicle interior occupant is provided with changing means for changing the set value, and the control device is configured to switch the operation state of the compressor in accordance with the set value by the changing means.

[0009]

When a variable displacement compressor is connected to a vehicle drive source, the rotation of the compressor increases with the rotation of the drive source, thereby increasing the cooling capacity of the compressor and the power consumption. Then, the control device switches the compressor to a small capacity, low capacity operation when the detected physical quantity detected by the detecting means for detecting the physical quantity corresponding to the rotation speed of the compressor becomes equal to or greater than a set value. As a result, the cooling capacity of the compressor decreases and the power consumption also decreases.

At this time, since the cooling capacity of the compressor is saturated, the rate of decrease is smaller than the rate of decrease in power consumption. Therefore, the power consumption is greatly reduced while the cooling capacity is not significantly reduced. Therefore, it is possible to prioritize the driving force by the drive source while securing the cooling capacity by the compressor.

Here, when the occupant changes the set number of revolutions by the changing means, the number of revolutions at which the compressor switches from the rated capacity operation to the low capacity operation can be arbitrarily changed. Power-saving operation can be executed according to.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment in which the present invention is applied to an air conditioner for an electric vehicle will be described below with reference to FIGS. FIG. 2 shows the configuration of the refrigeration cycle. In FIG. 2, the variable displacement compressor 1 discharges a high-temperature and high-pressure vaporized refrigerant in a driving state. The condenser 2 liquefies the refrigerant by condensing the high-temperature and high-pressure vaporized refrigerant from the compressor 1. The receiver 3 temporarily stores the liquefied refrigerant from the condenser 2 and removes water contained in the refrigerant. The expansion valve 4 atomizes the liquefied refrigerant from the receiver 3 by expanding it and sends the liquefied refrigerant to the evaporator 5. The expansion valve 4 is configured as a temperature-actuated valve that adjusts the amount of refrigerant to pass according to the outlet temperature of the evaporator 5. The evaporator 5
The atomized refrigerant from the expansion valve 4 is evaporated to absorb the surrounding heat and is liquefied before being discharged to the compressor 1.

FIG. 3 shows a connection structure between a motor as a drive source for running an electric vehicle and a compressor 1 for a refrigeration cycle. In FIG. 3, the motor 6 is connected to a drive system 8 of the electric vehicle via a clutch 7. A pulley 9 provided on a rotating shaft of the motor 6 is connected to a magnet clutch 11 of the compressor 1 via a timing belt 10. Therefore, when the clutch 7 is engaged, the drive system 8 is driven according to the rotation of the motor 6 to drive the electric vehicle, and when the magnet clutch 11 is energized, the compressor 1 is driven according to the rotation of the motor 6. It is designed to be driven.

Here, the compressor 1 is provided with a magnet valve 12.
Of the compressor 1 at the rated capacity of 100
% Is switched to a small capacity, for example, 20%. That is, the compressor 1 is provided so as to be switchable between a rated capacity operation and a small capacity low capacity operation. Further, the compressor 1 is provided with a rotation sensor 13 as rotation speed detecting means, and the rotation sensor 13 outputs an AC signal indicating the rotation speed of the compressor 1.

FIG. 4 schematically shows the configuration of the air conditioner. In FIG. 4, a blower fan 15 is provided at the start end of the air conditioning duct 14, and an inside / outside air switching damper 16 is provided opposite to the blower fan 15 according to the switching position of the inside / outside air switching damper 16. Outside air or inside air is drawn into the air conditioning duct 14. The evaporator 5 cools the air from the blower fan 15 in a passing state. On the rear side of the evaporator 5, a heater 17 that can be closed by an air mix damper 17a is provided. This heater 1
7 comprises an electric heater such as a PTC heater. A foot damper 18, a defroster damper 19, and a face damper 20 are provided corresponding to each of the air outlets provided at the end of the air conditioning duct 14.

FIG. 1 shows a control device for controlling the operation of the compressor 1. In FIG. 1, the control device 21 includes a power supply control circuit 22 and a capacity switching circuit 23. The power supply control circuit 22 has a positive power supply terminal 26 connected to the positive terminal of the vehicle battery 24 via a fuse 25, has a 0V terminal 27 connected to the negative terminal of the battery 24, and further has a power supply terminal. 28. One end of a relay coil 29 is connected to the positive power supply terminal 26. The collector of the transistor 30 is connected to the other end of the relay coil 29, and the emitter is connected to the 0V terminal. A relay switch 31 is connected between the positive power supply terminal 26 and the power supply terminal 28.

In this case, a high-level air conditioner ON signal is supplied to the base of the transistor 30 from an air conditioner switch (not shown). Therefore, when the air conditioner switch is turned on,
When the relay switch 31 is turned on in response to the turning on of the transistor 30, the power supply voltage of the battery 24 is output from the power supply terminal 28.

In the capacitance switching circuit 23, the power supply input terminal 32 is connected to the power supply terminal 28 of the power supply control circuit 22 and to the power supply terminal 33 for output.
The magnet coil 11 of the compressor 1 is connected to the power supply terminal 33. A rotation sensor 13 provided in the compressor is connected to the signal input terminals 34 and 35, and an AC signal from the rotation sensor 13 is supplied to the control main circuit 3.
6 given. The signal input terminal 35 is a 0V terminal 37.
To the negative terminal of the battery 24.

The emitter of the transistor 38 is connected to the power input terminal 32, and the collector is connected to the magnet valve 12 provided in the compressor 1 through the power supply terminal 39. The output of the control main circuit 36 is given to the base of the transistor 38.

The control main circuit 36 normally includes the transistor 3
When the frequency of the AC signal from the rotation sensor 13, that is, the rotation speed of the compressor 1 exceeds the set rotation, the transistor 38 is turned on.
Outputs a low-level signal to the base of.

FIG. 5 shows a control main circuit 36 of the capacity switching circuit 23.
Is schematically shown. That is, in the control main circuit 36, the waveform amplifying circuit 40 mainly includes the operational amplifier 41, and amplifies the AC signal input from the rotation sensor 13 through the noise filter 42. FV conversion circuit 43
Converts the AC signal input through the waveform shaping circuit 44 into a voltage corresponding to the frequency and outputs the voltage. Judgment circuit 45
Consists mainly of the comparator 46, and the comparator 4
The voltage signal from the FV conversion circuit 43 is supplied to the inverting input terminal 6. A voltage dividing circuit 49 composed of a series circuit of a resistor 47 and a variable resistor 48 supplies a reference voltage to a non-inverting input terminal of the comparator 46. Note that a hysteresis resistor 50 is connected to the comparator 46, and the reference voltage from the voltage dividing circuit 49 is changed according to the output level from the comparator 46. The output from the comparator 46 is supplied to the base of the transistor 38 through the buffer 51.

FIG. 6 shows an adjustment knob provided on the instrument panel of the vehicle. In FIG. 6, an adjustment knob 52 serving as a changing means adjusts the resistance value of the variable resistor 48 provided in the determination circuit 45 of the capacitance switching circuit 23, and furthermore, the reference voltage supplied from the voltage dividing circuit 49 to the comparator 46. From the “Max” position to “Ec
The rotation operation can be performed in the range up to the "o" position. In this case, when the adjustment knob 52 is positioned at “Max”, the reference voltage from the voltage dividing circuit 49 is the signal level of the voltage signal output when the compressor 1 is rotated at 2500 rpm from the FV conversion circuit 43. Is set to In the state where the adjustment knob 52 is located at “Eco”,
The reference voltage from the voltage dividing circuit 43 is set to the signal level of the voltage signal output from the FV converter circuit 43 when the compressor 1 rotates at 1700 rpm.

Next, the operation of the above configuration will be described. In the idling state where the accelerator is off, the motor 6
Is rotating at a predetermined speed. When the clutch 7 is engaged, the electric vehicle runs according to the rotation of the motor 6.

When an air conditioner switch (not shown) is turned on to air-condition the vehicle interior, the transistor 30 of the power supply control circuit 22 is turned on and the relay switch 3 is turned on.
When the switch 1 is turned on, the power supply voltage of the battery 24 is supplied to the magnet coil 11 through the capacity switching circuit 23. Thus, the compressor 11 is driven in accordance with the energization of the magnet coil 11, and the refrigerant circulates through the refrigeration cycle to cool the evaporator 5 accordingly. When the air is sucked into the air conditioning duct 14 in response to the drive of the blower fan 15, the air is cooled when passing through the evaporator 5, and a part of the cool air is adjusted to the angle of the air mix damper 17a. Accordingly, the air is heated when passing through the heater 17 to generate the conditioned air. This conditioned air is blown into the vehicle compartment from a predetermined outlet in accordance with the degree of opening of each of the dampers 18, 19, 20.

On the other hand, in the driving state of the compressor 1, an AC signal indicating the number of rotations of the compressor 1 is output from the rotation sensor 13 provided in the compressor 1 to the capacity switching circuit 23, and from the FV conversion circuit 43. A voltage signal corresponding to the rotation speed of the compressor 1 is output to the determination circuit 45.

At this time, in order to maximize the cooling capacity of the compressor 1, the adjustment knob 52 is set to "Ma".
Rotate to the "x" position. Then, the reference voltage output from the voltage dividing circuit 49 provided in the determination circuit 45 of the capacity switching circuit 23 becomes the reference voltage of the voltage signal output from the FV conversion circuit 43 when the rotation speed of the compressor 1 becomes 2500 rpm. Since the signal level is set, when the rotation speed of the motor 6 is low and the rotation speed of the compressor 1 is low, the voltage signal output from the FV conversion circuit 43 is equal to the reference voltage output from the voltage dividing circuit 49. Below. Therefore, since the comparator 46 outputs a high-level signal and the transistor 38 is turned off, the power supply voltage of the battery 24 is not supplied to the magnet valve 12, and the compressor 1 has a rated capacity of 100% capacity. Driven by

When the rotation of the motor 6 increases in response to the accelerator and the compressor 1 rotates at 2500 rpm or more, the voltage signal output from the FV conversion circuit 43 exceeds the reference voltage supplied to the comparator 46. As a result, the comparator 46 outputs a low level signal. As a result, the transistor 38 is turned on, and the power supply voltage of the battery 24 is supplied to the magnet valve 12 through the transistor 38, so that the magnet valve 12 is energized. Switch to operation. As a result, when the compressor 1 becomes 2500 revolutions or more, although the cooling capacity of the compressor 1 decreases,
Since the power consumption of the compressor 1 also decreases, the power consumption of the compressor 1 can be reduced while the cooling capacity of the compressor 1 is ensured, so that the power saving operation can be executed.

On the other hand, when it is desired to prioritize the power saving operation over the cooling capacity of the compressor 1, the adjustment knob 52 is rotated to the "Eco" position. Then, the voltage dividing circuit 49
The reference voltage from the compressor is 1700 rpm.
When the rotation speed of the motor 6 increases and the rotation speed of the compressor 1 exceeds 1700 rpm, the magnet valve 12 is energized. Then, the compressor 1 is switched to the low-capacity operation with a capacity of 20%. Therefore, when the compressor 1 rotates at 1700 rpm or more, although the cooling capacity of the compressor 1 decreases,
Since the power consumption of the compressor 1 also decreases, the power consumption of the compressor 1 can be reduced from a low rotation speed, and a further power-saving operation can be performed, as compared with the above case.

FIGS. 7 and 8 show the cooling capacity Q and the power consumption L with respect to the rotation of the compressor 1 using the capacity (100%, 20%) of the compressor 1 as a parameter. In this case, FIG. 7 shows that the capacity of the compressor 1 is switched from 100% to 20% at 2500 rpm.
Shows the characteristics when the capacity of the compressor 1 is switched at 1700 rpm. From FIGS. 7 and 8, when the compressor 1 is in a high rotation state of 1700 rpm or more, the consumed horsepower L increases in proportion to the rotation speed, whereas the cooling capacity Q becomes saturated and the degree of the increase increases. You can see it drops. Therefore, when the compressor 1 is switched from the rated capacity operation to the small capacity low capacity operation when the compressor 1 is rotating at a high speed of 1700 rpm or more, the reduction rate of the power consumption L is larger than that of the cooling capacity Q. Become. In other words, the power consumption L can be reduced without significantly impairing the cooling capacity Q.

According to the above configuration, the adjustment knob 52 can arbitrarily adjust the rotation speed at which the variable displacement compressor 1 switches from the rated capacity operation to the low capacity operation within a predetermined speed range. Unlike the conventional example in which the number of revolutions at which the capacity of the displacement type compressor is changed is constant, the compressor 1 is switched to a small capacity at an arbitrary rotation according to the running state of the electric vehicle or as desired, thereby cooling the compressor 1. The power saving operation can be executed by effectively reducing the power consumption of the compressor 1 while securing the capacity.

In the above embodiment, the number of rotations at which the compressor 1 is switched to the small capacity by the adjustment knob 52 is set to 170.
The range was set from 0 rpm to 2500 rpm, but the range can be set arbitrarily. That is, as an example, when the idling rotation speed of the motor 6 is set as the minimum rotation speed at which the compressor 1 switches to the small capacity, when the adjustment knob 52 is set to the “Eco” position, the compressor 1 is in the idling state of the motor 6. In this case, the low-capacity operation with a capacity of 20% allows the power-saving operation to be constantly executed. In this case, "Eco" of the adjustment dial 52
The display may be displayed as “idle” or “Idol”.

FIGS. 9 and 10 show a second embodiment of the present invention. The same parts as those of the first embodiment are denoted by the same reference numerals, and description thereof will be omitted. Only different parts will be described. FIG.
Denotes an operation button related to the air conditioner. An ECO button 54 as a changing means is provided beside the air conditioner button 53.

FIG. 10 shows the capacitance switching circuit 23.
In FIG. 10, the voltage dividing circuit 55 of the capacity switching circuit 23
Is formed by connecting a resistor 47, a switch 56 and resistors 57 and 58 as shown in the figure, and a common connection point between the contact 47 and the switch 56 is connected to the non-inverting input terminal of the comparator 46. This switch 56 is an ECO button 54
When the switch 56 is turned on in response to a pressing operation, the connection state to the resistor 57 is switched to the connection state to the resistor 58. In this case, when the switch 56 is off, the reference voltage from the voltage dividing circuit 55 is set to the signal level of the voltage signal output from the FV conversion circuit 43 when the compressor 1 rotates at 2500 rpm.
When the switch 56 is turned on, the reference voltage from the voltage dividing circuit 55 is supplied from the FV conversion circuit 43 to the compressor 1.
Is set to the signal level of the voltage signal output when rotating at 1700 rpm.

When the air conditioner button 53 is pressed, the compressor 1 is driven by the motor 6. At this time, when the ECO button 54 is not operated, the switch 56 of the voltage dividing circuit 55 is off.
To the non-inverting input terminal of the comparator 46, a reference voltage corresponding to the time when the rotation speed of the compressor 1 is 2500 rpm is output from the voltage dividing circuit 55. Therefore, the FV conversion circuit 4
Since the high level signal is output from the comparator 46 regardless of the signal level of the voltage signal from 3, the magnet valve 12 is not energized, and the compressor 1 is operated at the rated capacity.

When the rotation speed of the compressor 1 becomes 2500 rpm or more as the rotation of the motor 6 rises, the signal level of the voltage signal from the FV conversion circuit 43 becomes equal to the reference voltage from the voltage dividing circuit 55. As a result, the low level signal is output to the transistor 38, so that the magnet valve 12 is energized and the compressor 1 is switched to the low-capacity operation with a capacity of 20%, whereby the power-saving operation can be executed.

When priority is given to the power saving operation over the cooling capacity of the compressor 1, the ECO button 54 is pressed. Then, the switch 56 of the voltage dividing circuit 55 is turned on, and the reference voltage corresponding to the rotation speed of the compressor 1 of 1700 rpm is output from the voltage dividing circuit 55, so that the rotation of the compressor 1 When the number becomes 1700 rpm or more, the signal level of the voltage signal output from the FV conversion circuit 43 exceeds the reference voltage of the voltage dividing circuit 55. Then, the comparator 46
Outputs a low-level signal to turn on the transistor 38, so that the magnet valve 12 is energized and the compressor 1 is switched to low-capacity operation with a capacity of 20%. As a result, although the cooling capacity of the compressor 1 is reduced, the power consumption of the compressor 1 can be effectively reduced to a rate equal to or more than the reduction rate, and the power saving operation can be performed.

The display of the ECO button 54 is "Ec
Instead of "o", a character "power saving" may be displayed as shown in FIG. Further, in each of the above embodiments, the power supply control circuit 22 and the capacity switching circuit 23 are configured independently, but instead, both circuits may be configured integrally. Further, the present invention may be configured to be applied to an automobile using an engine as a drive source.

In addition, the number of rotations of the compressor 1 is detected from the rotation of the compressor 1 itself, but it is needless to say that the same function is provided even if a rotation signal of the motor 6 is input. In this case, without directly inputting the rotation of the compressor 1 or the motor 6, a means for detecting a physical quantity that changes in proportion to the rotation speed of the compressor 1 such as a discharge flow rate of the refrigerant from the compressor 1 is provided. Is also good.

[0039]

As is apparent from the above description, according to the air conditioner for a vehicle of the present invention, a variable displacement compressor connected to a drive source for driving a vehicle is provided, and the compressor is controlled by the control device to control the rotational speed. In the apparatus for switching from the rated capacity operation to the small capacity low capacity operation in accordance with the corresponding physical quantity, a change unit for changing a set value for switching the compressor from the rated capacity operation to the low capacity operation is provided, and the control device is provided in the vehicle interior. Since the operation state of the compressor is switched in accordance with the set value by the change means changed in response to the operation by the occupant , power saving operation is performed by using a variable displacement compressor. In the configuration, there is an excellent effect that power saving operation can be arbitrarily performed.

[Brief description of the drawings]

FIG. 1 is an overall electric circuit diagram showing a first embodiment of the present invention.

FIG. 2 is a schematic diagram of a refrigeration cycle.

FIG. 3 is a schematic diagram showing a connection structure between a motor and a compressor.

FIG. 4 is a schematic diagram showing a configuration of an air conditioning duct.

FIG. 5 is an electric circuit diagram showing a capacitance switching circuit.

FIG. 6 is a front view of an adjustment knob.

FIG. 7 is a characteristic diagram showing the relationship between the number of revolutions of the compressor, cooling capacity, and consumed horsepower.

FIG. 8 is a characteristic diagram showing the relationship between the number of revolutions of the compressor, the cooling capacity, and the consumed horsepower.

FIG. 9 is a front view of an operation button according to a second embodiment of the present invention.

FIG. 10 is a diagram corresponding to FIG. 5;

FIG. 11 is a view corresponding to FIG. 9 showing another embodiment of the present invention.

[Explanation of symbols]

1 is a compressor, 12 is a magnet valve, 13 is a rotation sensor (rotation speed detecting means), 21 is a control device, 52 is an adjustment knob (change means), and 54 is an ECO button (change means).

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int.Cl. ⁷ , DB name) B60H 1/32 624

Claims (1)

(57) [Claims] 1. A variable displacement compressor for a refrigeration cycle, which is provided so as to be connectable to a driving source for a vehicle and is capable of switching from a rated capacity operation to a small capacity, low capacity operation, and a physical quantity corresponding to a rotation speed of the compressor. Detecting means for detecting;
A moving vehicle air-conditioning apparatus provided with a control device for switching the low capacity operation from the rated operation capacity of the compressor when the detected physical quantity by the detecting means becomes a set value or more, changes the vehicle interior occupant changes the set value Means, and the control device is configured to switch an operation state of the compressor in accordance with a set value by the change means.