JP4358688B2 - Air conditioner for vehicles - Google Patents

Description

  The present invention relates to a vehicle air conditioner mounted on a vehicle or the like.

Conventionally, a compressor that compresses a low-temperature and low-pressure gas refrigerant and sends out a high-temperature and high-pressure gas refrigerant (hot gas), and a heat exchanger (condenser) that condenses the high-temperature and high-pressure gas refrigerant into a high-temperature and high-pressure liquid refrigerant A throttling mechanism that decompresses and expands the high-temperature and high-pressure liquid refrigerant to form a low-temperature and low-pressure liquid refrigerant (mist), and a heat exchanger that vaporizes the low-temperature and low-pressure liquid refrigerant to form a low-temperature and low-pressure gas refrigerant (evaporator); 2. Description of the Related Art A vehicle air conditioner using a refrigeration cycle that is formed by connecting the two by a refrigerant flow path is known.
This refrigeration cycle is used as a cooling device for cooling and dehumidification in an ordinary vehicle air conditioner. Further, as the heating device, a heat exchanger (heater core) using waste heat of a vehicle running engine (internal combustion engine) is generally used. The waste heat in this case uses the heat of engine cooling water that has been heated by cooling the engine to become hot water, and is also called a hot water heater.

In such a vehicle air conditioner, an evaporator having a cooling capability for cooling and dehumidification and a heater core having a heating capability for heating are provided in a flow path of conditioned air, for example, HVAC (Heating, Ventilation, and Air). -Conditioning) are arranged in series in the unit. And the air flow path which air-conditions with a damper etc. is switched, and cooling operation, heating operation, dehumidification heating operation, etc. are implemented.
In such a heating apparatus using waste heat of an internal combustion engine, the amount of waste heat tends to decrease with the recent increase in efficiency of the engine, and it has become difficult to obtain sufficient heating capacity. Therefore, a method of using an auxiliary heater such as an electric heater has been proposed in order to make up for the insufficient heating capacity (see, for example, Patent Document 1).
Further, a method has been proposed in which a part of the air heated by the heater core is further heated by an auxiliary heater and mixed on the downstream side (see, for example, Patent Documents 2 and 3).
Japanese Patent Laid-Open No. 11-5426 Japanese Patent Laid-Open No. 10-157444 JP 2003-34114 A

  In Patent Document 1 described above, since the auxiliary heater is disposed on the entire surface of the first air passage, the flow resistance of the first air passage may increase and the flow rate of air flowing through the first air passage may decrease. was there. When the air flow rate decreases, it becomes difficult to sufficiently use the heating capacity of the heater core having a larger heating capacity than that of the auxiliary heater, resulting in insufficient heating capacity.

In Patent Documents 2 and 3 described above, the air conditioning duct between the evaporator and the heater core is formed with a wall portion from the side surface toward the center portion, so that air tends to flow in a direction that escapes from the wall portion. there were.
Therefore, the distribution of the air flow rate flowing through the heater core becomes non-uniform, and there is a problem that the heating capacity of the heater core cannot be used sufficiently and the heating capacity tends to be insufficient.

In addition, since the auxiliary heater is disposed in a region where the air flow rate on the side where the wall portion of the air conditioning duct is formed is small, there is a problem that it is difficult to sufficiently use the heating capacity of the auxiliary heater.
Further, since the auxiliary heater has flow resistance, there is a problem that the flow rate of air flowing through the auxiliary heater is further reduced, and the heating capacity of the auxiliary heater is hardly exhibited.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a vehicle air conditioner that can improve the heating capacity.

In order to achieve the above object, the present invention provides the following means.
The vehicle air conditioner according to claim 1 is a casing that forms a flow path of air, an evaporator that cools air that has flowed into the flow path, a heater core that heats the cooled air, and a heater An auxiliary heater that heats a part of the air, and a wall portion that extends upward from a lower surface of the flow path so as to block the flow of the air in the flow path between the evaporator and the heater core. The heater core is supplied with hot water from the lower part of the heater core, and after exchanging heat with air, flows out from the upper part of the heater core, and the auxiliary heater is located above the downstream side of the heater core, and It is arrange | positioned in the area | region where the flow of the air biased by the wall part hits .

According to the present invention, by arranging the auxiliary heater in a region where the flow resistance is small, that is, in a region where the air flow rate is large, the flow resistance in the region where the auxiliary heater is arranged is increased, and the auxiliary heater is placed in another region Compared with the case where it arrange | positions, the flow volume distribution of the air which flows through the inside of the flow path of a heater core vicinity area | region can be equalize | homogenized. Therefore, heat can be uniformly transmitted to the air from substantially the entire surface of the heater core, and the heating capacity of the heater core can be used more effectively.
In addition, by arranging the auxiliary heater in a region where the air flow rate is large, more air can be applied to the auxiliary heater than in the case where the auxiliary heater is arranged in a region where the flow rate is low. Can be used more effectively. A PTC heater is suitable as the auxiliary heater.

By a wall portion provided between the d Baporeta and the heater core, as impinging on the flow of air deviates above the flow path, the auxiliary heater is disposed above the flow path. Therefore, compared with the case where an auxiliary heater is arrange | positioned in another area | region, the flow volume distribution of the air of a heater core vicinity area | region can be equalize | homogenized. Thereby, heat can be uniformly transmitted to the air from substantially the entire surface of the heater core, and the heating capacity of the heater core can be sufficiently used.
In addition, since the auxiliary heater is disposed so as to strike a biased air flow, more air can be applied to the auxiliary heater as compared with the case where it is disposed in other areas, and the capacity of the auxiliary heater is sufficiently Can be used. A PTC heater is suitable as the auxiliary heater.

  Further, for example, in the case where the air is heated by flowing warm water having a temperature higher than that of air in one direction in the heater core, the auxiliary heater is disposed in a region where the temperature of the warm water is reduced, thereby increasing the heating capacity of the auxiliary heater. It can be used sufficiently. Further, by arranging the heater core so that the region where the hot water temperature decreases and the region where the air flow is biased coincide with each other, the heating capacity of the heater core can be sufficiently used.

According to the vehicle air conditioner of the present invention, since the auxiliary heater is disposed in the region where the flow path resistance is low, more air can be applied to the auxiliary heater, and the heating capacity of the auxiliary heater is used more effectively. Can be achieved, and the heating capacity can be improved.
Moreover, since the flow rate distribution of the air hitting the heater core can be made uniform by arranging the auxiliary heater, the heating capacity of the heater core can be used more effectively, and the heating capacity can be improved. Play.

A vehicle air conditioner according to an embodiment of the present invention will be described with reference to FIGS. 1 to 3.
FIG. 1 is a perspective view showing a state in which the vehicle air conditioner according to the present embodiment is arranged at the front of the vehicle.
As shown in FIG. 1, the vehicle air conditioner 1 includes a vehicle air conditioning unit 10 that performs air conditioning such as cooling and heating, a refrigerant system 50 that supplies a refrigerant to the air conditioning unit 10 during cooling operation, and a heating operation. The heating source system 60 supplies engine cooling water serving as a heat source to the air conditioning unit 10.

FIG. 2 shows a cross section of a schematic configuration of the air conditioning unit 10.
The air conditioning unit 10 includes a casing 11, a blower fan (not shown) that sends air into the casing 11, an evaporator 12 that cools and dehumidifies the air, a heater core 13 that heats the cooled and dehumidified air, PTC (Positive Temperature Coefficient) heater (auxiliary heater) 14 that further heats the generated air. Hereinafter, the air conditioning unit 10 will be described in the order of air flow.

  An air inlet 21 is formed in the casing 11, and air is fed into the inlet 21 from a blower fan. The air flows in the flow path 22 formed in the casing 11 and flows into the evaporator 12. The evaporator 12 receives supply of low-temperature and low-pressure liquid refrigerant from a refrigerant system 50 (see FIG. 1), which will be described later, during the cooling operation, and performs heat exchange between the air passing through the evaporator 12 and the liquid refrigerant. As a result, the air is cooled and dehumidified by the heat absorbed by the refrigerant. During the heating operation, air that has passed through the evaporator 12 that is not operating is guided to the heater core 13 described later.

The heater core 13 is arranged in a substantially horizontal direction with respect to the evaporator 12, and hot water is supplied from the engine of the heating source system 60 (see FIG. 1). Hot water is supplied from the lower part of the heater core 13 (lower part in the figure), exchanges heat with air, flows out from the upper part of the heater core 13 (upper part in the figure), and is returned to the engine again.
A partition portion (wall portion) 23 that rises from the inner surface of the flow path 22 to the substantially central portion in the height direction is formed between the evaporator 12 and the heater core 13. The partition portion 23 blocks water dehumidified by the evaporator 12 and water such as rain that has entered the casing 11 from the outside so that the water does not enter further downstream at the lower corners thereof. The water blocked by the partition 23 is discharged from a drain 24 formed between the partition 23 and the evaporator 12.

An air mix damper 25 is disposed above the partition portion 23. The air mix damper 25 is provided so as to be rotatable around a substantially horizontal rotation shaft 25a facing the width direction of the casing 11 (perpendicular to the paper surface), and the tip end portion 25b swings. The partition portion 23 is brought into contact with and separated from the partition portion 23.
When the air mix damper 25 and the partition portion 23 are in contact with each other, the air mix damper 25 and the partition portion 23 prevent air from flowing into the heater core 13. The blocked air flows upward and flows into a defrost outlet 26, a face outlet 27, or a foot outlet 28 described later. As the air mix damper 25 is rotated and separated from the partition portion 23, the amount of inflow into the heater core 13 increases.
During the heating operation, the air mix damper 25 rotates upward, and all of the air that has passed through the evaporator 12 flows into the heater core 13.

A PTC heater 14 is disposed substantially parallel to the heater core 13 above the downstream side (left side in the figure) of the heater core 13.
As shown in FIG. 3, the PTC heater 14 supplies power to the heater casing 15, the PTC element 16 that generates heat, the fins 17 that transfer the heat generated from the PTC element 16 to the air, and the PTC element 16. The wiring 18 is schematically configured. The air flows in a direction perpendicular to the paper surface and flows between the surface of the PTC element 16 and the fins 17, thereby receiving heat from the PTC heater 14 and being heated.

  As shown in FIG. 2, the air heated by the heater core 13 and the PTC heater 14 flows upward behind the heater core 13 and the PTC heater 14 (rear stream side), and the defrost outlet 26 and the face blower described later. It flows into the outlet 27 or the foot outlet 28. A damper 29 sharing the air mix damper 25 and the rotating shaft 25a is disposed on the downstream side of the PTC heater 14. The damper 29 is configured to rotate in conjunction with the air mix damper 25. In a state where the air mix damper 25 is in contact with the partition portion 23, the damper 29 closes the flow path 22 so that the cool air does not flow backward to the heater core 13. During the heating operation, the flow path 22 is opened to allow heated air to flow into the defrost outlet 26, the face outlet 27, or the foot outlet 28.

In the upper part of the casing 11, a defrost outlet 26, a face outlet 27 and a foot outlet 28 are provided. A defrost / face damper 30 is attached between the defrost outlet 26 and the face outlet 27, and a foot damper 31 is attached between the face outlet 27 and the foot outlet 28.
The defrost / face damper 30 is supported so as to rotate about the rotation shaft 30a, and is arranged so as to close the defrost outlet 26 or the face outlet 27 by rotating. The foot damper 31 is supported so as to rotate about a rotation shaft 31a, and is disposed so as to close the foot outlet 28 by rotating. Further, the foot damper 31 can adjust the flow rate of air flowing to the foot outlet 28 and the flow rate of air flowing to the defrost outlet 26 or the face outlet 27 by changing the rotation position thereof.

Next, the configuration of the refrigerant system 50 will be described with reference to FIGS. 1 and 2.
As shown in FIGS. 1 and 2, the refrigerant system 50 supplies a low-temperature and low-pressure liquid refrigerant to the evaporator 12, and includes, in addition to the evaporator 12, a compressor 51, a condenser 52, and an expansion valve 53. It is roughly structured.
The compressor 51 compresses the low-temperature and low-pressure gas refrigerant vaporized by taking the heat of the air inside or outside the vehicle by the evaporator 12 and sends it to the condenser 52 as a high-temperature and high-pressure gas refrigerant. In the case of an automotive air conditioner, the compressor 51 receives a driving force for compressing the gas refrigerant from the normal engine 61 via a belt and a clutch.

  The condenser 52 is disposed in the front portion of the engine room 6 and discharges heat of the high-temperature and high-pressure gas refrigerant supplied from the compressor 51 to the outside air to condense and liquefy the gaseous refrigerant. The liquefied refrigerant is sent to a receiver (not shown) for gas-liquid separation, and then only the high-temperature and high-pressure liquid refrigerant is sent to the expansion valve 53. The expansion valve 53 decompresses and expands the high-temperature and high-pressure liquid refrigerant to form a low-temperature and low-pressure liquid (mist-like) refrigerant and supplies it to the evaporator 12. The expansion valve 53 is generally installed together with the evaporator 12.

Next, the configuration of the heat source system 60 will be described with reference to FIGS. 1 and 2.
As shown in FIGS. 1 and 2, the heating source system 60 supplies high-temperature engine cooling water serving as a heat source to the heater core 13. From the engine cooling water system that circulates between the engine 61 and the radiator 62, A part is introduced into the air conditioner.

  In the vehicle air conditioner 1 configured as described above, by driving a blower fan, air inside or outside the vehicle is introduced into the casing 11 from the inflow port 21 and sent to the evaporator 12. The air flowing in the evaporator 12 is cooled and dehumidified by taking heat away from the low-temperature and low-pressure refrigerant supplied from the refrigerant system 50, and further flows toward the heater core 13 on the downstream side.

Here, in the air flow toward the heater core 13, the flow below the flow path 22 is blocked by the partition portion 23, so that it flows above the flow path 22, and the air flow as a whole has low flow resistance. The flow is biased upwards of 22.
The air that has passed through the region where the partition 23 is formed then flows into the heater core 13. Since the PTC heater 14 is disposed above the downstream side of the heater core 13, the flow path resistance above the flow path 22 increases in the vicinity of the heater core 13. As a result, the air also flows below the heater core 13, the air flow biased upwards of the flow path 22 is made uniform, and the air flows uniformly into the heater core 13.

The air flowing into the heater core 13 is heated by the engine coolant when passing through the heater core 13. Since engine cooling water is supplied from below the heater core 13, the temperature is high below the heater core 13, and the temperature decreases as it flows upward. Therefore, also in the air heated by the heater core 13, the temperature of the air that has passed below is high, and the temperature of the air that has passed above is low.
The air that has passed over the heater core 13 flows into the PTC heater 14 and is heated when passing between the PTC element 16 and the fins 17.
The air heated by the heater core 13 and the PTC heater 14 is distributed to the outlets 26, 27, and 28 and blown out into the passenger compartment.

  According to the above configuration, the PTC heater 14 is disposed above the area where the air flow is biased by the partition 23, that is, above the flow path 22, so that the flow rate distribution of the air flowing in the vicinity of the heater core 13 is made uniform. Heat can be uniformly transmitted to the air from substantially the entire surface of the heater core 13. Therefore, compared with the case where a large amount of air flows through a partial region of the heater core 13, the amount of heat that can be transferred to the air can be increased, and the heating capacity of the vehicle air conditioner 1 can be improved.

In addition, since the PTC heater 14 is disposed above the heater core 13 where the temperature of the engine cooling water is decreased, the PTC heater 14 has a lower temperature air than in the case where it is disposed in another region. Flows in. Therefore, the PTC heater 14 can give more heat to the air that flows in, and the heating capacity of the PTC heater 14 can be used more effectively. As a result, the heating capacity of the vehicle air conditioner 1 can be improved.
Since a biased air flow is applied to the PTC heater 14, a large amount of air can be passed through the PTC heater 14, and the heating capacity of the PTC heater 14 can be increased compared to the case where a small amount of air is passed through the PTC heater 14. It can be used effectively.

Further, by using the PTC element 16 as a heat source of the PTC heater 14, the temperature of the PTC heater 14 can be kept constant without using a temperature sensor or a control unit. Moreover, even if the amount of air passing through the PTC heater 14 increases or the temperature of the passing air decreases, and the amount of heat taken away from the PTC heater 14 increases, the heat generation amount increases due to the characteristics of the PTC element 16. The temperature of the PTC heater 14 can be kept constant.
That is, the heating capacity of the PTC heater 14 can be used more effectively by disposing the PTC heater 14 above the flow path 22 that is a region where the air flow rate is high and the engine coolant temperature in the heater core 13 is lowered. Can do.

The technical scope of the present invention is not limited to the above embodiment, and various modifications can be made without departing from the spirit of the present invention.
For example, in the above-described embodiment, the PTC heater 14 using the PTC element 16 has been described as a configuration using the auxiliary heater of the heater core 13. However, the heating wire is not limited to the configuration using the PTC heater 14. It can be changed to an auxiliary heater using various other heat sources such as an auxiliary heater used or an auxiliary heater using engine cooling water.

It is the schematic which shows one Embodiment of the air conditioning apparatus for vehicles by this invention. It is sectional drawing which shows the air conditioning unit shown in FIG. It is a figure which shows the PTC heater shown in FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Vehicle air conditioner 11 Casing 12 Evaporator 13 Heater core 14 PTC heater (auxiliary heater)
22 Channel 23 Partition (wall)

Claims (1)

A casing that forms a flow path of air, an evaporator that cools air that has flowed into the flow path, a heater core that heats the cooled air, an auxiliary heater that heats a portion of the heated air, and the evaporator The flow path between the heater core and the heater core includes a wall portion that extends upward from the lower surface of the flow path so as to block the air flow ,
To the heater core, hot water is supplied from the lower part of the heater core, and after exchanging heat with air, flows out from the upper part of the heater core,
The vehicular air conditioner is characterized in that the auxiliary heater is disposed in a region above the wake side of the heater core and in a region where a flow of air biased by the wall portion hits .

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