JPH11198647A - Vehicular air conditioner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the cooling capacity of an air-conditioning unit by installing three bypass passages in an electrostatic air filter so as to make much air flow into a sectional part being lower in surface temperature as compared with other spots of an evaporator. SOLUTION: In a frame body 31 of an electrostatic air filter 19, three bypass passages 34 to 36 interconnecting both air upstream and downstream sides of the frame body 31 are formed in a section comformed to a sectional part being lower in surface temperature as compared with other spots of an evaporator 12, whereby much air is made so as to flow into the sectional part where the surface temperature of the evaporator 12 is low in consequence. With this, a blowoff air qunatity of air being blown into a cabin from a supply opening of an air-conditioning duct is made so as to be sufficiently securable in consequence.

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 that purifies polluted air contaminated by dust or dirt entering a passenger compartment or cigarette smoke emitted by an occupant in the passenger compartment.

[0002]

2. Description of the Related Art Conventionally, for example, contaminated air has been introduced into an air conditioning duct of an automotive air conditioner (car air conditioner) in order to prevent airborne dust or smoke from tobacco from adhering to an evaporator of a refrigeration cycle or from an outlet. In order to prevent the air from being blown into the vehicle interior, an electrostatic filter is disposed upstream of the evaporator in the air.

[0003]

However, in the conventional electrostatic filter for a car air conditioner, a bypass passage is provided at a position which is easy to manufacture in order to secure the amount of air blown from the outlet into the vehicle compartment. However, the position of the bypass passage is not specified. And from the bypass passage,
Since the airflow resistance is low, a large amount of air flows, so that the air does not uniformly flow into the evaporator, and much air flows only into the portion where the bypass passage is provided. As a result, the surface temperature increases only at the portion where the bypass passage is provided, and the temperature of the air blown into the vehicle interior increases, thereby causing a problem that the cooling performance of the car air conditioner decreases.

[0004]

SUMMARY OF THE INVENTION The present invention focuses on the fact that the surface temperature of a heat exchanger is not uniform, and bypasses such that more air flows into a portion having a different surface temperature as compared with other portions of the heat exchanger. An object of the present invention is to improve the air conditioning performance of a vehicle air conditioner by providing a passage in an electrostatic filter.

[0005]

According to the first aspect of the present invention, a bypass passage is provided in a portion of the surface of a heat exchanger of an electrostatic filter corresponding to a portion having a different surface temperature of the heat exchanger. With this arrangement, a large amount of air flows into portions of the heat exchanger having different surface temperatures. As a result, the amount of air blown out from the ventilation path into the vehicle interior can be secured, and the air conditioning performance of the vehicle interior can be improved.

According to the second aspect of the present invention, the surface temperature of the evaporator is reduced by providing a bypass passage in a portion of the surface of the evaporator corresponding to a portion where the surface temperature of the evaporator is low. A lot of air will flow into the site. As a result, the amount of air blown out from the ventilation path into the vehicle compartment can be secured. In addition, since the amount of air that is efficiently cooled when passing through the evaporator increases, the cooling performance in the vehicle compartment can be improved.

According to the third aspect of the present invention, by providing a bypass passage in the frame of the electrostatic filter in order to bypass the air from the electrostatic precipitator, the charging which is a main part of the electrostatic filter is provided. The bypass passage can be formed without reducing the effective area of the portion and the electric dust collecting portion. Thus, the amount of air blown out from the ventilation path into the vehicle compartment can be secured without significantly lowering the air purification performance of the electrostatic filter.

[0008]

1 to 5 show an embodiment of the present invention. FIG. 1 is a view showing an electrostatic air filter and an evaporator, and FIG. 2) is a diagram illustrating a main part of an air conditioning unit of the vehicle air conditioner, and FIG. 2B is a diagram illustrating a structure of an electrostatic air filter.

The air conditioner for a vehicle according to the present embodiment uses air conditioning units (actuators) in an air conditioning unit (air conditioner unit) 1 for air conditioning the interior of a vehicle equipped with a traveling engine or a traveling motor (not shown). The air-conditioning control device (hereinafter, referred to as an air-conditioning ECU) or a manual operation lever (not shown) performs automatic control or manual control.

The air-conditioning unit 1 has an air-conditioning duct 3 forming a ventilation path 2 for guiding conditioned air into the vehicle cabin at the front side of the vehicle cabin. On the upstream side of the air conditioning duct 3, an inside / outside air switching box 6 in which an outside air suction port 4 and an inside air suction port 5 are formed, and an inside / outside air switching door 7 for selectively opening and closing these suction ports are provided. A centrifugal blower 8 is provided downstream of the air.

The centrifugal blower 8 includes a scroll casing 9 integrally formed downstream of the inside / outside air switching box 6 on the air side, a blower motor 10 controlled by a blower driving circuit (not shown), and a centrifugal rotor driven by the blower motor 10. And a fan 11. In addition, air conditioning duct 3
An outlet switching box (not shown) having a defroster outlet, a face outlet, and a foot outlet formed on the downstream side of the air, and an outlet switching door (FIG. 1) for selectively opening and closing each of these outlets. (Not shown).

Next, a hot water heater (not shown), which is a heating heat exchanger for reheating the air passing through the evaporator 12, which will be described later, is provided upstream of the air outlet from the air outlet. An air mix door (not shown) is provided for adjusting the amount of air passing therethrough and the amount of air bypassing the hot water heater to adjust the temperature of the air blown from the air outlet into the vehicle interior.

An evaporator (refrigerant evaporator) 12, which is a component of a refrigeration cycle mounted on an automobile, is disposed upstream of the hot water heater so as to cover the entire ventilation path 2. Here, the refrigeration cycle includes a compressor (refrigerant compressor) that compresses and discharges the refrigerant, a condenser (refrigerant condenser) that condenses and liquefies the refrigerant discharged from the compressor, and gas-liquid separation of the refrigerant flowing from the condenser. (Neither is shown).

Further, the refrigeration cycle is shown in FIGS.
, A box-type automatic temperature expansion valve (pressure reducing means) 13 for reducing and expanding the liquid refrigerant flowing from the receiver,
And the evaporator 12 for evaporating and evaporating the refrigerant flowing from the expansion valve 13. The low pressure pipe 14 and the high pressure pipe 15 of the refrigeration cycle are inserted into the box-type automatic temperature expansion valve 13.
Further, a case 16 having a built-in diaphragm of the box-type automatic temperature expansion valve 13 and a heat-sensitive cylinder 17 attached to the low-pressure pipe 14 are connected via a capillary tube 18.

Next, the evaporator 12 is shown in FIGS.
This will be briefly described based on the above. Here, FIG. 3 is a diagram showing the downstream side of the air of the evaporator, FIG. 4 (a) is a diagram showing the temperature distribution of the air blown out from the evaporator, and FIG. 4 (b) is a flow direction of the refrigerant in the evaporator. FIG. 5 is a diagram showing the flow direction of the refrigerant in the evaporator.

The evaporator 12 is a cooling heat exchanger for cooling air purified by an electrostatic air filter 19 described later. The evaporator 12 has two tank portions at one end and a refrigerant evaporation passage at the other portion. This is a stacked heat exchanger in which a plurality of flat flow pipes 20 and corrugated fins 21 are alternately stacked. In order to standardize the shape by using the box-type automatic temperature expansion valve 13, the evaporator 12 has the inlet pipe 22 and the outlet pipe 28 adjacent to the approximate center of the plurality of flow pipes 20 in the stacking direction. Arranged to fit.

In the evaporator 12, FIG.
As shown in FIG. 5B and FIG. 5, the inlet pipe 22 → the inlet tank 23 → a plurality of substantially U-shaped inlet-side refrigerant evaporation passages 24 → the intermediate tank 25 → a plurality of substantially U-shaped outlet refrigerants. The refrigerant flows in the order of the evaporating passage 26 → the outlet tank 27 → the outlet pipe 28. Then, the evaporator 12 adjusts the refrigerant amount by the box-type automatic temperature expansion valve 13,
The refrigerant in the gas-liquid two-phase state exchanges heat with air in the inlet-side refrigerant evaporating passage 24 to be mostly evaporated and vaporized.
At the outlet side of 6, the evaporation is completed.

As a result, the surface temperature of the evaporator 12 is lower on the inlet side than on the outlet side.
As shown in (a), the temperature of the blown air that is exchanged with the refrigerant flowing in the inlet-side refrigerant evaporation passage 24 and is blown to the downstream side of the air is higher than the temperature of the refrigerant flowing in the outlet-side refrigerant evaporation passage 26 and the heat. The temperature becomes lower than the temperature of the blown air blown to the downstream side of the air after being replaced.

As shown in FIG. 4 (a), the refrigerant flowing from the inlet pipe 22 into the inlet tank 23 is the outermost flow pipe among the plurality of flow pipes 20. The flowability of the evaporator 12 toward the center in the stacking direction of the flow pipes 20 is higher, so that the cooling performance is higher. , Lower the surface temperature.

Similarly, the refrigerant flowing into the outlet tank 27 from the plurality of outlet-side refrigerant evaporation passages 26 is shown in FIG.
As shown in (a), the outermost one of the plurality of flow pipes 20 is located at the most central position of the plurality of flow pipes 20 than the outermost flow pipe. Since it is easier to flow toward the side flow pipe, the cooling performance is higher and the surface temperature is lower as the flow pipe 20 of the evaporator 12 is closer to the center in the stacking direction.
The tip of the inlet pipe 22 and the tip of the outlet pipe 28 are inserted into a joint plate 29 for mounting the box-type automatic temperature expansion valve 13.

Next, the electrostatic air filter 19 will be briefly described with reference to FIGS. The electrostatic air filter 19 is disposed in the ventilation path 2 between the centrifugal blower 3 and the evaporator 12 and is disposed so as to cover the entire ventilation path 2. Then, the electrostatic air filter 19
As shown in FIGS. 2A and 2B, a frame 31 forming a passage 30 therein and a passage 30 of the frame 31 are formed.
The charging unit 32 provided in the inside and the fine particles in the air charged by the charging unit 32 (tobacco smoke and dust invading from outside,
And an electric dust collecting unit 33 for collecting floating substances such as dust.

The frame body 31 is a resin frame formed in a substantially square shape, and corresponds to a portion where the surface temperature of the evaporator 12 is lower than other portions (portion surrounded by a broken line in FIG. 1). Have bypass passages 34-36. These bypass passages 34 to 36 are formed at the time of resin molding of the frame body 31 and penetrate the frame body 31 so as to communicate the air upstream side surface and the air downstream side surface. The bypass passages 34 to 36 are desirably provided at a portion corresponding to a portion where the surface temperature of the evaporator 12 is the lowest, but a portion having a lower temperature than a portion where the surface temperature of the evaporator 12 is relatively higher. Or a portion corresponding to a portion where the surface temperature of the evaporator 12 is lower than the portion where the surface temperature is the highest.

The charging section 32 is composed of a needle electrode and a counter electrode, and charges (positive or negative) fine particles in the air passing through the passage opening 30. The charging unit 3
As 2, an ionizer (ionization part) composed of a needle electrode and a plate-shaped counter electrode may be used. The electrostatic precipitator 33 is formed by spirally winding a plate-shaped electrode and a counter electrode and housed in the frame 31, and is an air for collecting and purifying fine particles charged by the charging unit 32. It is a purification unit. Note that a corrugated collector, a honeycomb-shaped collector, or the like may be used as the electric dust collector 33.

[Operation of Embodiment] Next, the operation of the air conditioning unit 1 of the present embodiment will be briefly described with reference to FIGS.

When the operation switch and the ignition switch of the vehicle air conditioner are turned on, the compressor and the blower motor 10 are started. Thereby, the centrifugal fan 11 rotates and air is sucked into the ventilation path 2 from the outside air suction port 4 or the inside air suction port 5. And ventilation passage 2
Part of the air sucked into the inside first enters the passage 30 of the electrostatic air filter 19 and is charged by the charging unit 32 with fine particles in the air (tobacco smoke, dust, dust, and the like that enter from the outside). Floating substances) are charged. Then, the fine particles in the air charged by the charging unit 32 are collected by the electric dust collection unit 33. The air thus purified flows into the evaporator 12, where the inlet-side refrigerant evaporation passages 2 of the plurality of flow pipes 20 are provided.
4 and the refrigerant flowing through the outlet-side refrigerant evaporation passage 26 exchanges heat and is cooled.

On the other hand, the remainder of the air sucked into the ventilation passage 2 passes through the bypass passages 34 to 36 formed in the frame 31 of the electrostatic air filter 19 and is sucked into the evaporator 12. At this time, the air that has passed through the bypass passages 34 to 36 is concentrated and flows into a portion of the evaporator 12 having a low surface temperature, and flows through the inlet-side refrigerant evaporation passages 24 of the plurality of flow pipes 20. It exchanges heat with and is cooled.

The cold air blown from the evaporator 12 bypasses the hot water heater or passes through the hot water heater in accordance with the opening degree of the air mixing door, so that, for example, an optimum air temperature corresponding to the target blowing temperature (TAO) is obtained. It becomes the conditioned air of temperature. Then, the conditioned air having the optimum temperature is blown into the vehicle compartment from, for example, a face outlet. Thereby, the vehicle interior is cooled.

[Effects of the Embodiment] As described above, in the air conditioning unit 1 of the present embodiment, the frame 31 of the electrostatic air filter 19 is compared with other portions of the evaporator 12 (of the surface). 1) Bypass passages 34 to 36 are formed on the upstream side of the air at a portion where the surface temperature of the evaporator 12 is low (portion surrounded by a broken line in FIG. 1). As a result, a lot of air flows into a portion where the surface temperature of the evaporator 12 is low. Therefore, in the air-conditioning unit 1 in which the electrostatic air filter 19 is disposed in the middle of the ventilation path 2 so as to cover the entire ventilation path 2. Also, for example, the amount of air blown out from the face outlet into the vehicle interior can be sufficiently ensured. Furthermore, since a lot of air passes through a portion of the evaporator 12 where the surface temperature is low, the amount of air that is efficiently cooled in the portion where the surface temperature is low increases, thereby improving the cooling performance in the vehicle compartment. Can be.

The charging unit 3 of the electrostatic air filter 19
Since the bypass passages 34 to 36 are provided in the frame body 31 for diverting air from the second and electric dust collecting parts 33, the effective area of the electric dust collecting part 33 which is a main part of the electrostatic air filter 19 is reduced. The bypass passages 34 to 36 can be formed without any need. Thus, for example, the amount of air blown out from the face outlet into the vehicle compartment can be secured without significantly lowering the air purification performance of the electrostatic air filter 19.

[Other Embodiments] In the present embodiment, the bypass passage 3 extends through the frame 31 in order to bypass the suction air from the electrostatic precipitator 33 of the electrostatic air filter 19.
4 to 36 are provided, but the frame 3
A bypass pipe may be formed in the communication pipe by inserting a communication pipe that connects the air upstream side and the air downstream side. Further, since the portion where the surface temperature of the evaporator 12 is the lowest is on the inlet side of the flow path pipe forming the refrigerant evaporation path near the inlet pipe, heat exchange is performed with the refrigerant flowing through the refrigerant evaporation path in the flow path pipe. , A bypass passage may be formed.

In the present embodiment, the evaporator 12 is arranged so that the inlet tank 23, the intermediate tank 25 and the outlet tank 27 are located in the ventilation passage 2, but the air-conditioning duct 3 is provided with a concave portion, and the concave portion is provided. If the inlet tank 23, the intermediate tank 25, and the outlet tank 27 are located at the same position, the evaporator 12 can be disposed so that only the refrigerant evaporation passage is present in the ventilation passage 2.

In the present embodiment, an evaporator 1 is used as a heat exchanger in which an inlet pipe 22 and an outlet pipe 28 are disposed adjacent to each other at a substantially central portion in the stacking direction of a plurality of flow pipes 20.
Although the example using No. 2 was shown, as the heat exchanger, the inlet pipe and the outlet pipe were respectively connected to the outermost flow pipes on both sides arranged on the outermost side of the plurality of flow pipes. An evaporator may be used.

The evaporator 12 is used as a heat exchanger.
Condenser (refrigerant condenser) in addition to cooling heat exchangers
Alternatively, a heating heat exchanger such as a hot water heater (heater core) may be used. When such a heating heat exchanger is used, a portion of the surface of the heating heat exchanger where the surface temperature of the heating heat exchanger is high compared to other portions of the heating heat exchanger. A bypass passage is provided in a portion corresponding to.
In this case, by providing the bypass passage, the heating performance can be improved.

[Brief description of the drawings]

FIG. 1 is a perspective view showing an electrostatic air filter and an evaporator (Embodiment).

FIG. 2A is a schematic diagram illustrating a main part of an air conditioning unit of an automotive air conditioner, and FIG. 2B is an explanatory diagram illustrating a structure of an electrostatic air filter (embodiment).

FIG. 3 is a front view showing an air downstream side of the evaporator (embodiment).

FIG. 4A is a diagram showing a temperature distribution of air blown from an evaporator, and FIG. 4B is an explanatory diagram showing a flow direction of a refrigerant in the evaporator (Embodiment).

FIG. 5 is an explanatory diagram showing a flow direction of a refrigerant in an evaporator (embodiment).

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Air-conditioning unit 2 Ventilation path 3 Air-conditioning duct 12 Evaporator (Heat exchanger) 13 Box-type automatic temperature expansion valve 19 Electrostatic air filter (Electrostatic filter) 20 Flow pipe 22 Inlet pipe 28 Outlet pipe 30 Passage port 31 Frame Body 32 Charging part 33 Electric dust collecting part 34 Bypass passage 35 Bypass passage 36 Bypass passage

Claims (3)

[Claims] An air passage for sending air into a vehicle interior, a heat exchanger arranged to cover the entire surface of the air passage, and exchanging heat between air flowing through the air passage and a refrigerant, An air-conditioning system for a vehicle, comprising: an electrostatic filter having an electric dust-collecting unit for purifying contaminated air, the electrostatic filter being disposed to cover the entire surface of the ventilation path on the air upstream side of the exchanger. Has a bypass passage for diverting air from the electrostatic precipitator at a portion of the surface of the heat exchanger corresponding to a portion where the surface temperature of the heat exchanger is different. apparatus. 2. The vehicle air conditioner according to claim 1, wherein the heat exchanger is an evaporator for cooling the air flowing in the ventilation path by exchanging heat with a refrigerant, and the bypass passage is provided for the evaporator. The vehicle air conditioner is provided at a portion corresponding to a portion of the surface of the evaporator where the surface temperature of the evaporator is low. 3. The air conditioner for a vehicle according to claim 1, wherein the electrostatic filter is disposed so as to cover an entire surface of the ventilation path, and has a passage through which air passes. A frame, and a charging unit provided in a passage opening of the frame, for charging a floating substance, wherein the bypass passage penetrates the frame to bypass air from the electrostatic precipitator. An air conditioner for a vehicle, which is provided.