JP6357374B2 - Air conditioner for vehicles - Google Patents

Description

  The present invention relates to a vehicle air conditioner, and more particularly to a vehicle air conditioner that cools using an electric motor driven compressor during idle stop.

In a vehicle equipped with an idle stop function, a general vehicle air conditioner includes an engine-driven compressor driven by power from a traveling engine and a motor-driven compressor driven by power from a battery. . As a result, during the cooling operation, when the engine is stopped due to a signal waiting or the like, the engine drive compressor stops due to the engine stop, but the motor drive compressor continues the cooling operation.
However, since the motor-driven compressor is driven by power from the battery, there is a problem that consumption of battery power increases.

  Therefore, in the invention described in Patent Document 1, when the compressor stops during idle stop, the amount of air blown by the blower is reduced. Of the outlets toward the upper body side of the occupant in the passenger compartment and the outlets toward the foot side It is designed to extend the time during which the comfort of the passenger compartment can be maintained by blowing from one side.

JP 2013-91385 A

  By the way, in the summer season when cooling is required, in order to maintain the comfort of the passengers in the passenger compartment, the air blowing mode in which the blown air directly hits the passenger's face and arms, and the cooling operation with a high cooling load is performed. It is assumed that

Here, during the cooling operation with a high cooling load, moisture contained in the air in the passenger compartment is condensed, and water droplets are attached to the surface of the evaporator.
In this state, when the state is shifted to the idle stop state and the cooling load of the electric motor driven compressor is reduced or the compressor is not used as in Patent Document 1, air that is not sufficiently dehumidified is blown into the vehicle interior. End up.

For this reason, if the cooling load is reduced during the idling stop and the cooling operation is performed in the air blowing mode as in the prior art, the air containing a lot of moisture directly hits the face and arms of the occupant. There is a problem.
As a result, the idling stop possible time is shortened by starting the engine and using the engine-driven compressor in order to improve the comfort in the passenger compartment.

  The present invention has been made by paying attention to such a conventional problem. During idle stop, the power consumption of the motor-driven compressor is reduced to suppress the battery power consumption and to reduce the discomfort of the occupant. An object of the present invention is to provide a vehicle air conditioner that can be used.

  In order to solve the above-mentioned problems, the present invention is characterized in that a vehicle air conditioner that cools using an electric motor driven compressor during idle stop has the following configuration.

  When the solar radiation amount sensor for detecting the solar radiation amount and the solar radiation amount detected by the solar radiation amount sensor during idling stop are below a predetermined value, the cooling load is reduced so as to reduce the power consumption of the motor-driven compressor. And a control device that reduces the amount of air flow toward the upper body side of the occupant.

According to the present invention, during idle stop, when the amount of solar radiation is below a predetermined value, the cooling load of the motor-driven compressor is reduced, and the amount of air flow toward the upper body side of the occupant is reduced, thereby containing a lot of moisture. Since the amount of air blown by the air hitting the occupant's face and arms is suppressed, the discomfort of the occupant can be reduced while suppressing battery power consumption.
In addition, the comfort in the vehicle compartment during idle stop is maintained, so that the idle stop possible time can be extended.

The schematic block diagram of the vehicle air conditioner which shows one Embodiment of this invention Control flow diagram during idle stop

Embodiments of the present invention will be described below with reference to the drawings.
FIG. 1 is a schematic configuration diagram of a vehicle air conditioner. The vehicle air conditioner according to the present embodiment uses an engine (internal combustion engine) 1 as a drive source and satisfies an idle stop condition corresponding to a signal waiting or the like. Thus, the present invention is applied to an idle stop vehicle having a function of automatically stopping the engine 1.

  The refrigerant circuit 2 circulates a fluorocarbon refrigerant, and includes an evaporator 22 disposed in an HVAC (Heating Ventilation and Air Conditioning) unit 20 described later, an engine-driven compressor 3 to which an outlet side pipe of the evaporator 22 is connected, A condenser 4 to which an outlet side pipe of the engine driven compressor 3 is connected and an electric motor driven compressor (hereinafter referred to as “electric compressor”) 5 arranged in parallel with the engine driven compressor 3 are included. The outlet side piping of the capacitor 4 is connected to the evaporator 22 via the liquid receiver 6 and the expansion valve 7.

  The engine-driven compressor 3 is driven by power from the engine 1 via a pulley and a belt 12, and has a clutch 13 interposed between the pulley and the drive shaft of the compressor 3.

The electric compressor 5 has a built-in electric motor (motor) and is driven by this motor. The motor is supplied with power from the battery 9. The battery 9 is charged by an alternator 10 that is belt-driven by the engine 1.
Each of the compressors 3 and 5 compresses a low-pressure low-temperature gas refrigerant to obtain a high-pressure high-temperature gas refrigerant.

  The condenser 4 uses the cooling fan 8 to cool the high-pressure high-temperature gas refrigerant from the compressor 3 or 5 to the condensation point with the outdoor air, and reduces the refrigerant to a high-pressure normal-temperature liquid refrigerant.

  The liquid receiver 6 temporarily stores the refrigerant liquefied by the capacitor 4 and supplies only the liquid refrigerant. Moreover, the liquid receiver 6 removes the water | moisture content in a refrigerant | coolant by letting it pass through a desiccant so that it may be called RD (receiver dryer). The expansion valve 7 is provided at the inlet of the evaporator 22 and depressurizes the refrigerant flowing into the evaporator 22. Moreover, it has integrally the detection part 7a which detects the exit temperature and exit pressure of the evaporator 22. FIG.

  The HVAC unit 20 includes a blower 21 that takes in air from the outside air inlet or the inside air inlet, an evaporator 22 that is a cooling heat exchanger, a heater core 24 that is a heating heat exchanger, and an evaporator 22 or a heater core 24. And an air-conditioning outlet that blows out the temperature-controlled air by heat exchange. As the air-conditioning air outlet, the air blown out is a foot air outlet 25 directed toward the passenger's foot, a face air outlet 26 directed toward the upper body side of the occupant, and a defroster air outlet 27 for removing fog such as windshield. Is provided.

  The evaporator 22 is arrange | positioned in the ventilation path by the blower 21, and evaporates the refrigerant | coolant from the expansion valve 7, taking heat from the circumference | surroundings. This cools indoor air (air blown out into the passenger compartment). The heater core 24 is disposed downstream of the evaporator 22 in the air passage, and warms the cooled air during heating.

  Further, a damper 23 that can freely open and close the vent is attached to the vent of the heater core 24. The opening / closing angle of the damper 23 is controlled according to the temperature setting. The air blown from the blower 21 is first cooled by the evaporator 22. The cooled air is heated by the heater core 24 and the amount of air that flows to the air conditioning outlet and the amount of air that bypasses the heater core 24 and flows to the air conditioning outlet while being cooled are adjusted by the damper 23.

  Each outlet 25, 26, and 27 is provided with a foot valve 25a, a face valve 26a, and a defroster valve 27a, and the amount of air blown from each outlet is appropriately controlled by valve control.

  Specific valve control includes a foot mode in which only the foot valve 25a is opened and air is blown toward the occupant's feet, a face mode in which only the face valve 26a is opened and air is directed toward the occupant's upper body, the foot valve 25a and There is a bi-level mode in which the face valve 26a is simultaneously opened to blow air toward the upper body side and the foot side.

  A radiator 11 is provided in the cooling water circuit 14 of the engine 1, and the radiator 11 cools the engine cooling water that has circulated through the engine 1 and has become high temperature by exchanging heat with outside air. Here, the heater core 24 is arranged in parallel with the radiator 11. Therefore, in the HVAC unit 20, the heater core 24 can heat the air flowing through the engine cooling water (cooling water received by cooling the engine 1) as a heat medium.

  During the cooling operation of the vehicle air conditioner, the refrigerant in the refrigerant circuit 2 is compressed by the engine-driven compressor 3 or the electric compressor 5, condensed by the condenser 4, expanded by the expansion valve 7, and then sent to the evaporator 22. After being evaporated, the flow returns to the compressor 3 or 5.

  Therefore, in the HVAC unit 20, the evaporator 22 takes the heat of vaporization from the air flowing through it and cools the air. The air cooled by the evaporator 22 is blown out from an appropriate outlet and is used for cooling the passenger compartment.

Next, the idle stop vehicle will be described.
In an idle stop vehicle, the engine is automatically stopped under a predetermined idle stop condition corresponding to a signal wait or the like, and after the idle stop, the engine is used with a starter motor under a predetermined idle stop release condition corresponding to a start operation or the like. Is automatically started.

The idle stop condition is, for example, when the following (1) to (3) are established.
(1) Vehicle speed = 0
(2) Shift position is non-traveling position (neutral position) or clutch is disengaged (clutch pedal switch ON)
(3) Brake pedal switch ON

The idle stop cancellation condition is, for example, when any of the following (1) to (3) is satisfied.
(1) Shift position changes to travel position (gear-in position) (2) Clutch changes to connected state (clutch pedal switch OFF) (3) Brake switch turns OFF However, these conditions are only examples and other conditions It goes without saying that (or a combination) may be adopted.

The idling stop vehicle compresses the refrigerant using the engine drive compressor 3 because the engine 1 is driven during normal operation.
On the other hand, since the engine 1 is stopped during the idle stop, the electric compressor 5 is used to compress the refrigerant.

  Here, in summer when cooling is required, for example, when the difference between the air temperature from the air outlet and the temperature in the passenger compartment is large and the cooling load is high, the air is usually blown toward the upper body side of the occupant. It is assumed that the face mode is automatically controlled.

  However, as already described, when shifting to the idle stop state while being controlled in the face mode, if the cooling load is reduced in order to reduce the power consumption of the electric compressor 5, the evaporator 22 flows. The air is not sufficiently dehumidified, and air containing a large amount of moisture is blown out from the face outlet 26. As a result, air containing a lot of moisture directly hits the occupant's face and arms, making the occupant uncomfortable and impairing the comfort of the passenger compartment.

  Therefore, in this embodiment, when there is a cooling operation request during idle stop, the amount of solar radiation entering the vehicle interior is a predetermined value or less, that is, at night such as summer when cooling is required or when the sunlight is relatively weak, In addition to energy-saving control of the electric compressor 5, control is performed to switch the air blowing mode from the face mode to another mode so that the amount of air blown on the face and arms of the occupant without being dehumidified can be suppressed. Thereby, during idle stop, while dissipating battery 9 electric power, a passenger | crew's discomfort is reduced and it can maintain the comfort in a vehicle interior.

The air conditioning control during the idle stop is executed by the control device 30 in FIG.
Moreover, the control apparatus 30 reads the solar radiation amount detected by the solar radiation amount sensor 40 in FIG. 1, for example, the solar radiation amount sensor 40 outputs the detected solar radiation amount to the control apparatus 30 as an electric current value. . In addition to the amount of solar radiation, the control device 30 reads various sensor values such as the inside air temperature and humidity, the outside air temperature and humidity, and the battery voltage detected by various sensors (not shown).

  The air conditioning control during idle stop according to the present invention will be described with reference to the control flowchart of FIG. This flow is executed when the vehicle shifts to the idle stop state during the cooling operation in the state controlled by the face mode (normal control). Since the engine 1 is stopped simultaneously with the start of this flow, the electric compressor 5 is operated in place of the engine drive compressor 3.

In step S1, the various sensor values are read by the control device 30.
In step S2, it is determined whether or not the amount of solar radiation among the various sensor values is equal to or less than a predetermined value. Here, the amount of solar radiation is represented by the amount of heat per unit area (W / m ² ).

  In step S <b> 3, the target value of the outlet air temperature of the evaporator 22 is set high, thereby increasing the refrigerant temperature and reducing the cooling load of the electric compressor 5. That is, the target value of the outlet air temperature of the evaporator 22 is set to 10 ° C., for example, and energy saving control is performed with reduced power consumption of the electric compressor 5 (in contrast, the target of the outlet air temperature of the evaporator 22 in high output control) The value is 3 ° C).

In step S4, air blow mode switching control is performed. Specifically, control for switching the air blowing mode from the face mode to the foot mode or the bi-level mode is performed.
In step S5, it is determined whether an idle stop cancellation condition is met. If applicable, the idle stop is canceled and the engine 1 is started, so the engine-driven compressor 3 is operated in place of the electric compressor 5. If not, it is determined again whether the idle stop cancellation condition is met.

On the other hand, when the amount of solar radiation is larger than the predetermined value in step S2, energy saving control and air blow mode switching control are not performed.
At this time, if energy saving control or switching control to a mode other than the face mode is performed, there is a concern that the amount of air flow toward the upper body side of the occupant decreases and the sensible temperature rises, or the vehicle interior becomes hot due to solar heat. Is done. In other words, when the daytime or sunlight is strong, such as in summer, it is required to perform a cooling operation under normal control in which the cooling load of the compressor is increased and the amount of air flow toward the occupant's upper body is increased by the face mode.
Accordingly, the energy saving control and the air blowing mode switching control are not performed, and the process proceeds to step S6 to perform the cooling operation by the normal control. Then, it progresses to step S5 and it is determined whether it corresponds to idle stop cancellation | release conditions.

  After the start of operation of the engine drive compressor 3 in step S5, the routine shifts to normal control.

  According to the present embodiment, during idle stop, when the amount of solar radiation is less than a predetermined value, the evaporator outlet air temperature is set high to reduce the cooling load, thereby reducing the power consumption of the electric compressor. Cooling operation can be performed at.

According to this embodiment, as described above, the cooling load is reduced so as to reduce the power consumption of the electric compressor, and the moisture is controlled by controlling the air blowing mode from the face mode to the foot mode or the bi-level mode. The contained air is blown to the foot side of the occupant or from both the upper body side and the foot side.
In other words, when the sun needs to be cooled, such as in the summer or when the sun is relatively weak, even if air that has not been sufficiently dehumidified is blown into the passenger compartment due to the energy-saving control of the electric compressor, it will directly hit the passenger's face and arms. Air volume is suppressed.
Therefore, it is possible to reduce the discomfort of the occupant while suppressing the consumption of battery power during the idle stop, and as a result, it is possible to maintain the comfort in the passenger compartment, and thus it is possible to extend the idle stop possible time.

  The illustrated embodiment is merely an example of the present invention, and the present invention is not limited to the embodiment described directly, but includes various improvements or modifications made by those skilled in the art within the scope of the claims. Needless to say, it encompasses changes.

DESCRIPTION OF SYMBOLS 1 ... Engine 2 ... Refrigerant circuit 3 ... Engine drive compressor 4 ... Condenser 5 ... Electric motor drive compressor 6 ... Liquid receiver 7 ... Expansion valve 7a ... Detection part 8 ... Cooling fan 9 ... Battery 10 ... Alternator 11 ... Radiator 12 ... Belt DESCRIPTION OF SYMBOLS 13 ... Clutch 14 ... Cooling water circuit 20 ... HVAC unit 21 ... Blower 22 ... Evaporator 23 ... Damper 24 ... Heater core 25 ... Foot outlet 25a ... Foot valve 26 ... Face outlet 26a ... Face valve 27 ... Defroster outlet 27a ... Defroster Valve 30 ... Control device 40 ... Solar radiation sensor

Claims (3)

In a vehicle air conditioner that cools using an electric motor driven compressor during idle stop,
A solar radiation sensor for detecting solar radiation;
During idle stop, when the amount of solar radiation detected by the solar radiation amount sensor is below a predetermined value, the cooling load is reduced so as to reduce the power consumption of the motor-driven compressor, and the amount of air flow toward the upper body side of the occupant A control device for lowering,
A vehicle air conditioner comprising:   2. The vehicle air conditioner according to claim 1, wherein the control device reduces a cooling load by setting a target value of an outlet air temperature of the evaporator to be high.   From the face mode that blows air toward the upper body side of the occupant, the foot mode that blows air toward the feet side of the occupant, or the bi-level that blows air toward both the upper body side and the foot side of the occupant The vehicle air conditioner according to claim 1 or 2, wherein an air flow rate toward the upper body side of the occupant is reduced by switching to a mode.