JP3085329B2 - 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 capable of heating a vehicle interior by circulating air (inside air) in the vehicle interior.

[0002]

2. Description of the Related Art As a technique for improving the heating capacity of an air conditioner for a vehicle, there is a technique of sucking and heating inside air and blowing the air into a vehicle compartment. This technique is particularly effective for vehicles having a low heat source for heating, such as diesel engine vehicles and electric vehicles, but has the problem of fogging of window glass. Therefore, a technique disclosed in Japanese Utility Model Laid-Open No. 57-163409 has been proposed. In this technology, humidity in a vehicle compartment is detected by a humidity sensor, and air outside the vehicle compartment (outside air) is sucked in accordance with the detected humidity to prevent fogging of a window glass.

[0003]

In the prior art, a dedicated humidity sensor for detecting the humidity of inside air is required, and there is a problem that unnecessary outside air is introduced due to a detection error of the humidity sensor.

[0004]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and has as its object to reduce unnecessary dehumidification by paying attention to the fact that the humidity in the vehicle interior changes according to the number of occupants. It is an object of the present invention to provide an air conditioner for a vehicle in which heating performance is improved or energy required for heating is reduced.

[0005]

The vehicle air conditioner of the present invention employs the following technical means. A duct for sending air toward the cabin, a blower for generating an airflow toward the cabin in the duct, and arranged in the duct,
Heating means for heating the air passing therethrough, is provided in the duct so as to be able to heat the inside air circulation that sucks the room air, and the duct is introduced by introducing the outside air of the vehicle compartment, or is arranged in the duct. The air conditioner for a vehicle capable of dehumidifying by operating the cooling means for cooling the air passing therethrough includes an occupant number detecting means for detecting the number of occupants of the vehicle. A control circuit is provided for performing dehumidification when the dehumidification start time set according to the number of occupants detected by the detection means is reached.

[0006]

In the heating operation for circulating the inside air, the inside air is sucked into the duct, and the sucked air is heated by the heating means and blown out into the passenger compartment to heat the passenger compartment. On the other hand, the control circuit
The dehumidification start time is set based on the number of occupants detected by the occupant number detecting means. Then, the elapsed time counted from the time when the occupant determines that the humidity in the passenger compartment starts to increase, such as after the occupant gets on the vehicle, or after the window glass is closed, or since the previous dehumidification is finished,
When the dehumidification start time is reached, the outside air is sucked into the duct or the cooling means in the duct is operated to blow low-humidity air into the passenger compartment. Thereby, the humidity in the vehicle compartment is suppressed, and the fogging of the window glass is suppressed.

[0007]

As described above, the air conditioner for a vehicle according to the present invention dehumidifies the interior of the vehicle according to the number of occupants. Since the humidity in the cabin changes according to the number of occupants, unnecessary dehumidifying operation can be reduced by performing dehumidification in the cabin according to the number of occupants, and as a result, the heating capacity is improved, or heating is required. Energy consumption can be reduced.

[0008]

Next, an air conditioner for a vehicle according to the present invention will be described with reference to an embodiment shown in the drawings. 1 to 11 show an embodiment of the present invention, and FIG. 1 is a schematic structural view of a duct of an air conditioner. The vehicle air conditioner 1 according to the present embodiment is mounted on, for example, an electric vehicle, and includes a duct 2 forming an air passage for sending air toward a room. One end of the duct 2 is connected to a first blower 3 and a second blower 4 for generating an airflow toward the room in the duct 2. The first blower 3 is provided with inside / outside air switching means 5 for switching the intake air into inside air or outside air. The inside / outside air switching means 5 includes an inside air introduction port 6 for introducing inside air, and an outside air introduction port 7 for introducing outside air. The inside / outside air switching means 5 includes an inside / outside air switching damper 8, and the inside / outside air switching damper 8 can switch the air sucked by the first blower 3 between inside air and outside air. The second blower 4 always sucks only inside air, and has an inside air inlet 9 for introducing inside air.

At the other end of the duct 2, there is formed an outlet for blowing air passing through the duct 2 toward each part in the room. The air outlet is mainly a center face air outlet 10 for blowing cold air toward the upper body of the occupant from the center of the front of the cabin, and a center face air outlet 10 from both sides of the front of the cabin to the upper body or the side window glass of the occupant. A side face outlet 11 for blowing cold air to the front, a defroster outlet 12 for blowing hot air mainly toward the front window glass, and a foot outlet 13 for blowing hot air mainly toward the feet of the occupant.
In the duct 2, a center face damper 14, a defroster damper 16, and a foot damper 17 for controlling an air flow to each air outlet are provided in an air passage leading to another air outlet except the side face air outlet 11. ing.

A cooling means 18 for cooling the air flowing through the duct 2 is disposed upstream of the duct 2.
Downstream thereof, a heating means 19 for heating the air flowing in the duct 2 is arranged. The cooling means 18 is provided in the duct 2.
And a heating bypass passage 21 that bypasses the heating means 19.
Thereby, in the duct 2, the first flow path 22 that passes only the cooling means 18, the second flow path 23 that passes both the cooling means 18 and the heating means 19, and the second flow path 23 that passes only the heating means 19 The three flow paths 24 can be formed. The heating bypass passage 21 is provided with a cool damper 25 for opening and closing the heating bypass passage 21. By closing the heating bypass passage 21 with the cool damper 25,
All the air that has passed through the cooling means 18 passes through the heating means 19.

Further, a first partition wall 26 for separating the air blown out by the first blower 3 and the air blown out by the second blower 4 and passing the cooling means 18 upstream of the cooling means 18 in the duct 2. Is provided. The cooling means 18
A second partition wall 27 that separates the air that has passed through the cooling means 18 from the air that has passed through only the heating means 19 without passing through the cooling means 18 is provided downstream. Note that the heating means 19 is disposed in the duct 2 so as to penetrate the second partition wall 27. A differential mode opening 28 is provided downstream of the second partition wall 27 for guiding air that has passed only through the heating means 19 to the defroster outlet 12 in the defroster mode.
Is provided. The differential mode opening 28 has a differential mode damper 29 for opening and closing the differential mode opening 28.
Is provided to open the differential mode opening 28 when the defroster mode is selected by the user.

The cooling means 18 of this embodiment is a refrigerant evaporator of the refrigeration cycle 32, and the heating means 19 of this embodiment is a refrigerant condenser of the refrigeration cycle 32. An example of the refrigeration cycle 32 employed in this embodiment is shown in the refrigerant circuit diagram of FIG. The refrigeration cycle 32 of the present embodiment is an accumulator cycle. In addition to the refrigerant evaporator (cooling means 18) and the refrigerant condenser (heating means 19), an outdoor heat exchanger 33, a refrigerant compressor 34, a pressure reducing device 35, an accumulator 36, and a flow path switching means 37 for switching the flow direction of the refrigerant.
The outdoor heat exchanger 33 performs heat exchange between the outside air and the refrigerant outside the duct 2, and includes an outdoor fan 38 and an outside air shutter 39. The refrigerant compressor 34 performs suction, compression, and discharge of the refrigerant, and is driven by an electric motor 40. The refrigerant compressor 34 is disposed in the sealed case 41 integrally with the electric motor 40. The rotation speed of the electric motor 40 that drives the refrigerant compressor 34 is variable under the control of the inverter 42. The change in the rotation speed of the electric motor 40 changes the refrigerant discharge capacity of the refrigerant compressor 34. The vehicle air conditioner 1 of the present embodiment is
The blowout temperature is controlled by a change in capacity due to a change in the rotation speed of the refrigerant compressor 34. Decompression device 35
Is an expansion valve that decompresses and expands the refrigerant flowing into the refrigerant evaporator (cooling means 18), and is provided, for example, to adjust the supercool amount of the refrigerant condenser (heating means 19) during the dehumidifying operation. The refrigerant flow switching means 37 switches the flow direction of the refrigerant in a cooling operation, a heating operation, and a dehumidifying operation. Specifically, a four-way valve 43 for switching the discharge direction of the refrigerant compressor 34 between the outdoor heat exchanger 33 and the refrigerant condenser (heating means 19), a refrigerant evaporator (cooling means 1) during the heating operation.
8) An electromagnetic opening / closing valve 44 for bypassing the refrigerant valve, an electromagnetic three-way valve 45 for bypassing the refrigerant condenser (heating means 19) during cooling operation, and a check valve 46 for regulating the flow direction of the refrigerant.

The flow path switching means 37 switches the flow of the refrigerant as follows in accordance with the cooling operation, the heating operation, and the dehumidifying operation. During the cooling operation, the refrigerant compressor 3
The refrigerant discharged in 4 is supplied to the four-way valve 43 → the outdoor heat exchanger 33 →
Depressurizing device 3 bypassing refrigerant condenser (heating means 19)
5 → refrigerant evaporator (cooling means 18) → four-way valve 43 → accumulator 36 → refrigerant compressor 34 (arrow C in the figure)
reference). During the heating operation, the refrigerant discharged from the refrigerant compressor 34 passes the four-way valve 43 → the refrigerant condenser (the heating unit 19) → the decompression device 35 → bypasses the refrigerant evaporator (the cooling unit 18) to the outdoor heat exchanger 33 ( Outdoor fan 38 ON, shutter 39 open)
→ Flow in the order of the four-way valve 43 → the accumulator 36 → the refrigerant compressor 34 (see arrow H in the figure). During the dehumidifying operation, the refrigerant discharged from the refrigerant compressor 34 is supplied to the four-way valve 43 → the refrigerant condenser (the heating unit 19) → the pressure reducing device 35 → the refrigerant evaporator (the cooling unit 1).
8) → The outdoor heat exchanger 33 (the outdoor fan 38 is OFF, the shutter 39 is closed) → the four-way valve 43 → the accumulator 36 → the refrigerant compressor 34 flows in this order (see arrow D in the figure).

The first blower 3, the second blower 4, the inverter 42 of the electric motor 40, the outdoor fan 38, the four-way valve 43, the electromagnetic on-off valve 44, the electromagnetic three-way valve 45, and the actuators for driving the dampers and the shutter 39 ( Electric components (not shown) are controlled to be energized by the control device 47. The control device 47 controls the energization of each electric component in accordance with an operation signal of an operation panel (not shown) operated by an occupant, and the operation panel is installed at a position in the room with good operability. The control of the air conditioner 1 by the control device 47 according to the present embodiment can be automatically controlled so that the vehicle interior is maintained at a temperature set by the user. As shown in FIG. , An inside air sensor 49 for detecting the inside air temperature, an outside air sensor 50 for detecting the outside air temperature, a solar radiation sensor 51 for detecting the amount of solar radiation, and an occupant number detecting means 5 for detecting the number of occupants.
2 is provided. Then, when an auto air conditioner switch (not shown) set on the operation panel is operated, the temperature in the vehicle compartment is automatically controlled to the temperature set by the temperature setting means 48 according to the following flowchart.

The operation of the automatic temperature control by the controller 47 will be described with reference to the flowchart of FIG. First, it is determined whether or not an ignition switch (not shown) is turned on (step S1). If the determination is NO, the process returns to step S1, and if YES, the elapsed time T since the ignition switch was turned on is counted (step S2). Subsequently, a signal from each sensor or the like is input, and the set temperature Tset, the inside air temperature Tr, and the outside air temperature Ta are input.
m, the amount of solar radiation Ts, and the number of occupants are input (step S3).
Next, the target outlet temperature TAO is calculated based on the following equation (step S4).

## EQU00001 ## TAO = Kset.times.Tset-Kr.times.Tr-Kam.times.Tam-Ks.times.Ts + C Note that Kset, Kr, Kam, and Ks are coefficients of each sensor, and C is a constant. Next, based on the calculated target blow temperature TAO, the relationship between the target blow temperature TAO shown in FIG. 5 and the airflow of the first blower 3 and the second blower 4 indicates that the first blower 3 and the second blower 4 The air volume is set (step S5). Then, based on the calculated target outlet temperature TAO, the target outlet temperature TAO shown in FIG.
From the relationship of the switching state of the inside / outside air switching damper 8, it is determined whether the air sucked by the first blower 3 is inside air or outside air (step S6). Subsequently, based on the calculated target outlet temperature TAO, the outlet mode is determined from the relationship between the target outlet temperature TAO and the outlet mode (face mode, bi-level mode, foot mode) shown in FIG. 7 (step S7). . Subsequently, the open / close state of the cool damper 25 and the differential mode damper 29 is determined according to the blowing mode (step S8).
). Subsequently, the operation state of the refrigeration cycle 32 is determined according to the target outlet temperature TAO. That is, the refrigerant compressor 3
The rotation speed (including the rotation speed 0) and the operation mode (cooling operation, heating operation, dehumidification operation) of Step 4 are determined (Step S9).
). Next, control is performed to determine whether or not to perform a dehumidifying operation (step S10). This dehumidification operation control will be described later. Thereafter, according to the determination result of step S5, the first blower 3
And the energization voltage of the second blower 4 is controlled (step S1).
1) The inside / outside air switching damper 8 is controlled according to the determination result of step S6 to switch the inside / outside air (step S12), and the center face damper 1 is controlled according to the determination result of step S7.
4. The blow mode is set by controlling the defroster damper 16 and the foot damper 17 (step S13), and step S8 is performed.
The cool damper 25 and the differential mode damper 29 are controlled in accordance with the determination result (step S14). Then, the operation state of the refrigeration cycle 32 is controlled in accordance with the result of the determination in step S9 (step S15), and the process returns.

Next, the dehumidification control performed in step S10 will be described. When the heating operation is performed by the above control, the control device 47 performs the heating operation by circulating the internal air. The heating by the inside air circulation means the inside / outside air switching means 5.
Completely shuts off the outside air, sucks the inside air into the duct 2,
It is heated by the heating means 19 and blown out into the vehicle interior to heat the vehicle interior. Since the humidity in the heating by the inside air circulation increases, the control device 47 performs the dehumidifying operation intermittently according to the number of occupants of the vehicle. Specifically, when the heating operation is performed (even in the present embodiment other than the heating operation), the elapsed time T from the time when the vehicle occupant gets on the vehicle (in this embodiment, from the time when the ignition is turned on). Control unit 47
When the elapsed time T reaches a dehumidification start time set according to the number of occupants, dehumidification is performed.
FIG. 8 shows the relationship between the absolute humidity in the passenger compartment and the riding time with respect to the number of passengers, and FIG. 9 shows the relationship between the dehumidification start time and the number of passengers. In addition, the dehumidification of the present embodiment includes the introduction of outside air into the duct 2, the dehumidification operation by the refrigeration cycle 32, and the first dehumidification.
The dehumidification is performed by increasing the air volume of the blower 3 and the second blower 4. Then, a dehumidifying operation is performed for a predetermined time (for example, 1 to 5 minutes) (this dehumidifying time may be set according to the number of occupants). After the dehumidifying operation is performed for a predetermined time, the heating operation by the inside air circulation is performed again. . When the heating operation time due to the inside air circulation again reaches the dehumidification start time set according to the number of occupants, the dehumidification operation is performed, and the intermittent dehumidification heating operation is repeated. Further, in the present embodiment, as the occupant number detecting means 52 for detecting the number of occupants of the vehicle, a seat belt wearing detection switch mounted on a buckle of each seat belt (not shown) is used. This switch is an existing switch that turns on when the seat belt is worn.
The number of occupants can be detected from the number.

Next, the dehumidifying operation control by the control device 47 will be described with reference to the flowchart of FIG. First,
It is determined whether the number of occupants is one, the cooling operation is being performed, or the dehumidifying operation is manually selected by the user (step S16). If the result of this determination is YES (any one of the above determinations is YES), the operation proceeds to step S11 described above. When the determination result is NO (all of the above determinations are NO), from the relationship between the number of occupants and the dehumidification start time shown in FIG.
A dehumidification start time t (long when the number of occupants is small and short when the number of occupants is large) is set according to the number of occupants (step S17). Next, it is determined whether or not the time T from when the ignition counted by the control device 47 is turned ON or the time T after the previous dehumidification has ended reaches the dehumidification start time t set in step S17. Make a decision (Step S1
8). If the result of the determination is NO, the process proceeds to step S11 without the need for dehumidification. If the result of the determination is YES, the dehumidifying operation is performed for a predetermined time. That is, the air volume of the first and second blowers 3, 4 is increased, and the inside / outside air switching means 5 is switched to outside air introduction,
A dehumidification operation in which the refrigeration cycle 32 is operated for dehumidification is performed for a predetermined period of time (step S19). Then, after the end of the dehumidifying operation, the process proceeds to step S11, and the temperature control is performed.

[Operation of Embodiment] Next, the operation of the above embodiment will be described with reference to a time chart of FIG. When the occupant gets into the vehicle (ignition is turned on) and heating by the inside air circulation is started, the humidity in the vehicle compartment increases as indicated by the rising line A. When the dehumidification start time set according to the number of occupants is reached after the ignition is turned on, the dehumidification operation is performed for a predetermined time by the operation of the control device 47, and the humidity in the vehicle interior decreases as indicated by the descending line B. I do. When the dehumidification is completed, the heating by the internal air circulation is started again, and the humidity in the vehicle compartment rises as shown by the rising line C. When the dehumidification start time set according to the number of occupants is reached after the end of the previous dehumidification, the control device 47 operates to perform the dehumidification operation again for a predetermined time, and the humidity in the vehicle compartment is indicated by a falling line D. So fall. Thereafter, heating and dehumidification of the internal air circulation are intermittently repeated. In other words, even if the humidity rises due to the heating by the inside air circulation, dehumidification is started immediately before the window glass becomes clouded, so that the window glass can be prevented from being clouded.

[Effects of the Embodiment] In this embodiment, the dehumidifying operation is intermittently performed at a rate corresponding to the number of occupants during the heating operation of the internal air circulation. Since the humidity in the vehicle interior changes according to the number of occupants, unnecessary dehumidification operation can be reduced by intermittently dehumidifying the interior of the vehicle at a rate corresponding to the number of occupants, and energy consumption for heating can be suppressed. As a result, the power consumption of the electric vehicle can be suppressed, the running distance can be improved, and the output can be prevented from lowering. Further, in this embodiment, since the seatbelt wearing switch is used as the occupant number detecting means 52 for detecting the number of occupants, it is not necessary to newly provide a detecting means for detecting the number of occupants. For this reason, the detection means for starting dehumidification becomes unnecessary, and the cost can be suppressed low.

[Modification] The air conditioner of the above embodiment is
Although an example in which the inside of the duct is divided into a plurality of layers has been described, the present invention is not limited to a duct having a plurality of layers, and for example, the present invention may be applied to a single-layer duct of one blower. That is, the present invention is applicable to all vehicle air conditioners that perform heating by internal air circulation. In the above-described embodiment, an example in which a seat belt wearing switch is used as the means for detecting the number of occupants is shown. However, as another means, an infrared sensor is provided in the vehicle compartment to detect the number of occupants, or Other detection means may be employed, such as providing a switch that is turned on when the operation is performed, or providing operation means for setting the number of occupants by manual operation of the occupant. In the above embodiment, the dehumidification start time is uniquely set according to the number of occupants. However, a learning function may be provided in the control device to vary the dehumidification start time. Specifically, for example, after the ignition is turned on, or after the previous dehumidification is completed,
The time until the defroster switch or the dehumidification switch is operated may be stored, the dehumidification start time may be corrected by the memory value, and the dehumidification may be automatically started at the corrected dehumidification start time from the next time. In the above embodiment, when performing the dehumidification, the example in which the amount of air is increased and the dehumidification by the introduction of the outside air and the dehumidification by the operation of the cooling means are performed at the same time, but only one of the introduction of the outside air or the operation of the cooling means is performed. It may be provided as follows. In the above embodiment, the air conditioner is mounted on an electric vehicle. However, the air conditioner may be mounted on an internal combustion engine, particularly a vehicle driven by a diesel engine. Furthermore, although a refrigerant condenser has been described as an example of the heating means, other heating means such as a hot water heater core, an electric heater, and a combustion heater may be used.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of a duct of an air conditioner.

FIG. 2 is a refrigerant circuit diagram of a refrigeration cycle.

FIG. 3 is a block diagram of a control device.

FIG. 4 is a flowchart of temperature control.

FIG. 5 is a graph showing a relationship between a target blowing temperature and an air volume of a blower.

FIG. 6 is a graph showing a relationship between a target outlet temperature and a switching state between inside and outside air.

FIG. 7 is a graph showing a relationship between a target blowing temperature and a blowing mode.

FIG. 8 is a graph showing the relationship between the absolute humidity in the vehicle compartment and the riding time.

FIG. 9 is a graph showing the relationship between the number of occupants and the dehumidification start time.

FIG. 10 is a flowchart of dehumidification control.

FIG. 11 is a time chart for explaining the operation.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Vehicle air conditioner 2 Duct 3 1st blower 4 2nd blower 18 Cooling means 19 Heating means 47 Control circuit 52 Number of occupants detecting means

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) B60H 3/00 B60H 1/00 101

Claims (1)

(57) [Claims] 1. A duct for sending air toward a passenger compartment, a blower for generating an airflow in the duct toward the passenger compartment, and a heating means disposed in the duct for heating the passing air, Heating of the inside air circulation that sucks the room air is provided therein, and the duct introduces the outside air of the vehicle interior, or the cooling means for cooling the passing air disposed in the duct is operated. Accordingly, the vehicle air conditioner is capable of dehumidifying, the vehicle air conditioner includes a number of occupants detecting means for detecting the number of occupants of the vehicle, when heating the internal air circulation, by the number of occupants detecting means An air conditioner for a vehicle, comprising: a control circuit for performing dehumidification when a dehumidification start time set according to a detected number of occupants is reached.