JP2001219731A - Air conditioner for automobile - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an air conditioner for an automobile capable of restricting lowering of blown air temperature to provide comfortableness at the time of heating. SOLUTION: In this air conditioner for an automobile provided with a warm water type heater 9 using cooling water in an internal combustion engine 20 as a heat source, and an electric heater 10 for supplementing heating capacity of the warm water type heater 9, a control unit 40 starts actuation of the electric heater 10 when the internal combustion engine 20 is stopped while the air conditioner is actuated.

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, and more particularly to an air conditioner for a vehicle having a hot water heater using heat of engine cooling water as a heat source and an electric heater for converting electric energy into heat.

[0002]

2. Description of the Related Art A conventional air conditioner for a vehicle includes a hot water heater for heating air and an electric heater for supplementing insufficient heating of air by the hot water heater. This type of automotive air conditioner is mounted on a so-called hybrid vehicle that uses, for example, an internal combustion engine and an electric motor as running power sources.

The hot water heater includes an inlet tank into which engine cooling water flows, an outlet tank from which engine cooling water flows, and a plurality of flat tubes for guiding the engine cooling water from the inlet tank to the outlet tank. Have.

[0004] The inlet and outlet tanks are arranged parallel to each other, and a plurality of flat tubes are arranged in the longitudinal direction of both tanks. The heating element of the electric heater is arranged between the flat tubes.

[0005] One end of an inflow and outflow hot water pipe is connected to the inlet and outlet tanks, respectively, and the other end of the hot water pipe is connected to a water jacket of the internal combustion engine. A water temperature sensor is mounted in the hot water pipe. The water temperature sensor and the electric heater are each electrically connected to the control unit.

When the engine coolant circulates between the water jacket and the hot water heater, the hot water heater radiates heat. As the air in the air conditioning unit passes through the hot water heater, the air is heated. The amount of heat released from the hot water heater is managed by monitoring the temperature of the engine cooling water. That is, the temperature of the engine cooling water is detected by the water temperature sensor,
This water temperature information is sent to the control unit.

When the temperature of the engine cooling water drops due to the stop of the engine, or when the temperature of the engine cooling water does not rise due to being used in a cold region and the heating amount of the hot water heater is insufficient, the control unit is used. Activates the electric heater. As a result, the heating element of the electric heater generates heat.

FIG. 6 is a diagram showing changes over time in the temperature of air blown out of a conventional automotive air conditioner and the temperature of engine cooling water.

When the internal combustion engine stops and the temperature 150 of the engine cooling water drops below a predetermined value (temperature at which the operation of the hot water heater starts), the electric heater operates to compensate for the insufficient heating capacity of the hot water heater. As a result, the temperature 151 of the air blown out from the vehicle air conditioner increases.

[0010]

However, as described above, since the electric heater is started when the temperature of the engine cooling water falls below a predetermined value, it takes time until the temperature of the engine cooling water reaches the predetermined value. Meanwhile, there is a problem in that the temperature of the air blown out from the vehicle air conditioner decreases, and comfort during heating is impaired.

In particular, in a hybrid vehicle equipped with an internal combustion engine and an electric motor, the driving power source is switched in accordance with the driving state, and the frequency of the stop of the internal combustion engine and the decrease in the temperature of the engine cooling water increases. The temperature of the air blown out of the air conditioner tends to decrease, and the problem may become more serious.

The present invention has been made in view of such circumstances, and an object of the present invention is to provide a vehicle air conditioner that can suppress a decrease in the temperature of blown air at the time of heating and can obtain comfort. .

[0013]

According to a first aspect of the present invention, there is provided an air conditioner for a vehicle, comprising: a hot water heater using cooling water of an internal combustion engine as a heat source; and a heating capacity of the hot water heater. An air conditioner for an automobile, comprising: an electric heater for compensating for the above problem, characterized in that the air conditioner further comprises control means for starting the operation of the electric heater when the internal combustion engine is stopped while the air conditioner is operating. I do.

When the internal combustion engine is stopped while the air conditioner is operating, the operation of the electric heater is started, so that the time from when the temperature of the blown air starts to decrease until it returns to the original temperature is shortened. In addition, the decrease in the temperature of the blown air decreases.

According to a second aspect of the present invention, in the vehicle air conditioner according to the first aspect, the control unit is configured to control the electric heater when the temperature of the electric heater exceeds a predetermined value. The operation of is stopped.

As described above, when the temperature of the electric heater exceeds a predetermined value, the control means stops the operation of the electric heater, so that the temperature of the blown air is maintained at the predetermined value.

According to a third aspect of the present invention, there is provided an air conditioner for a vehicle according to the first or second aspect.
The control means stops the operation of the electric heater when the amount of air passing through the hot water heater is adjusted to zero by an air mixing door.

When no air passes through the electric heater, the operation of the electric heater is stopped, so that the electric heater does not heat wastefully.

[0019]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram of an air conditioner for a vehicle according to an embodiment of the present invention, FIG. 2 (a) is a front view of a heater, FIG. 2 (b) is a side view, and FIG. 3 is FIG. III-III
It is sectional drawing which follows a line.

This automobile air conditioner has a blower unit 1
An air conditioner unit 2 for adjusting the air from the blower unit 1, a heater control system 38 for controlling the heating amount of the heater 6 in the air conditioner unit 2, a duct 31 for guiding the air from the air conditioner unit 2 to the passenger compartment, 32,3
3 is provided.

This automotive air conditioner is mounted, for example, on a hybrid vehicle using an internal combustion engine 20 and an electric motor (not shown) as a driving power source.

The blower unit 1 has a fan 3 and a motor 4 for driving the fan 3.

The air conditioner unit 2 includes a blower unit 1
An evaporator 5 for cooling air from the heater, a heater 6 for heating air passing through the evaporator 5, and a heater 6
An air mix door 7 for adjusting the ratio of air passing through and air not passing therethrough, and a unit case 8 accommodating them.

The evaporator 5 is arranged on the upstream side of the heater 6.

The heater 6 is a hot water type heater 9 (PTC)
And an electric heater 10 that compensates for the lack of heating capacity of the hot water heater 9.

The hot water heater 9 is a heater that uses engine cooling water (cooling water) of the internal combustion engine 20 as a heat source. As shown in FIG. 2, the hot water type heater 9 includes tanks 11 and 12.
While guiding the engine cooling water from the upstream chamber 11a of the tank 11 to the tank 12,
Flat tubes 13 and 14 for guiding to one downstream chamber 11b
And fins (not shown) for promoting heat radiation of the engine cooling water in the flat tubes 13 and 14. The flat tube 13 is a tube on the outward path flowing from the tank 11 to the tank 12, and the flat tube 14 is a tube on the return path flowing from the tank 12 to the tank 11.

The tanks 11 and 12 are arranged in parallel with each other, and a plurality of flat tubes 13 and 14 and fins are alternately stacked in the longitudinal direction of the tanks 11 and 12. However, FIG. 2A is a schematic diagram, and fins are not shown. The upstream chamber 11a of the tank 11 has an inlet 15 for engine cooling water, and the downstream chamber 11b of the tank 11 has an outlet 1
6 are provided. An opening 17 for inserting an electric heater 10 described later is formed at one end of the tank 11 in the longitudinal direction. The width H1 of the tank 11 is formed wider than the width H2 of the tank 12, and the volume in the tank 11 is larger than the tank 12 by the volume of the electric heater 10 (see FIG. 3).

The inflow port 15 and the outflow port 16 are connected to one ends of hot water pipes 18 and 19 for inflow and outflow, respectively. The other ends of the hot water pipes 18 and 19 are connected to a water jacket (not shown) of the internal combustion engine 20.

The electric heater 10 is a battery (not shown)
Is a heater that converts the electric energy of the above into heat. The electric heater 10 has a heating unit 21. A connector 22 is electrically connected to the heat generating portion 21. Electric heater 1
0 is inserted into the upstream chamber 11 a of the tank 11 of the hot water heater 9, and the connector 22 is exposed to the outside through the opening 17. The tank 11 is hermetically sealed by fitting a fitting portion (not shown) formed at the end 10 a of the electric heater 10 into the opening 17.

The engine cooling water circulates between the water jacket of the internal combustion engine 20 and the hot water heater 9, and the heat of the internal combustion engine 20 is transmitted to the hot water heater 9 via the engine cooling water. The engine cooling water flowing from the inlet 15 enters the upstream chamber 11a of the tank 11, and this upstream chamber 1a
From 1a, it passes through the flat tube 13 and flows into the tank 12. The engine cooling water in the tank 12 passes through the flat tube 14 and returns to the downstream chamber 11b of the tank 11.

The width H1 of the tank 11 is equal to the width H2 of the tank 12.
And the volume in the tank 11 is larger than that of the electric heater 10.
Therefore, even if the electric heater 10 is inserted into the tank 11, the cross-sectional area of the flow path of the tank 11 does not become smaller than the cross-sectional area of the flow path of the tank 12.

The heater control system 38 includes a water temperature sensor 39 for monitoring the temperature of the engine cooling water, a sensor 43 for detecting the operating state of the internal combustion engine 20, a sensor 44 for detecting the operating state of the fan 3, and a vehicle air conditioner. Inside air temperature sensor 45 for detecting the temperature of air blown out of the device
And a control unit (control means) 40 for controlling the electric heater 10 based on signals from the sensors 39 and the like.
And

The water temperature sensor 39 is mounted in the hot water pipe 15 for inflow, the sensor 43 is mounted on the internal combustion engine 20, the sensor 44 is mounted on the fan 3, and the inside air temperature sensor 45 is mounted on the instrument panel (not shown). . The water temperature sensor 39, the fan 3, the motor 4, the sensors 43 and 44, the inside air temperature sensor 45, and the electric heater 10 are electrically connected to the control unit 40. A switch panel 41 is connected to the control unit 40. The control unit 40 operates or stops the motor 4 according to the input from the switch panel 22.

In the unit case 8, the evaporator 5
An air mix space where the cold air bypass passage 25 through which the air passing through the air flows, the hot air passage 26 through which the air passing through the heater 6 flows, and the air downstream of the cool air bypass passage 25 and the air downstream of the hot air passage 26 are mixed. 27 are formed.

The air mix space 27 is located downstream of the air mix door 7. Downstream of the air mix space 27 of the unit case 8, an opening 28 for diff blowing, an opening 29 for vent blowing, and an opening 30 for foot blowing are formed.
Ducts 31, 32, and 33 are connected to the differential blowing opening 28, the vent blowing opening 29, and the foot blowing opening 30, respectively.

Air mix space 2 in unit case 8
Downstream of 7, the mode switching doors 34, 35, 36 are rotatably provided. Mode switching doors 34, 35, 36
Is operated by a link mechanism (not shown), and the blowing mode is determined.

Here, the flow of air when the blowing mode is set to the full hot mode, the air mix door 7 is opened to the maximum, the mode switching doors 34 and 36 are opened, and the mode switching door 35 is closed will be described. I do.

From the blower unit 1 to the air conditioner unit 2
The air introduced therein goes to the evaporator 5. All the air passing through the evaporator 5 goes to the heater 6. The air that has passed through the heater 6 is blown out of the unit case 8 from the differential blowing opening 28 and the foot blowing opening 30 through the warm air passage 26. This air is blown into the passenger compartment through ducts 31 and 33.

FIG. 4 is a diagram showing the change over time in the temperature of the air blown from the automotive air conditioner and the temperature of the engine cooling water, and FIG. 5 is a flow chart for explaining the control method of the electric heater by the control unit. . Note that S1 to S11 indicate each step of the processing.

As shown in FIG. 4, before the internal combustion engine 20 stops, the temperature 50 of the engine cooling water and the temperature 51 of the air blown out from the vehicle air conditioner are each maintained at a predetermined value. When the driving power source is switched from the internal combustion engine 20 to the electric motor and the internal combustion engine 20 stops, the temperature 50 of the engine cooling water and the temperature 51 of the blown air begin to decrease.

At this time, as shown in FIG.
It is determined whether or not the fan 3 is operating based on the information from (1) (step S1). When the fan 3 is operating (YES), the process proceeds to step S2.

Next, in step S2, based on the information from the sensor 43, it is determined whether or not the internal combustion engine 20 is operating. When the internal combustion engine 20 is stopped, the process proceeds to step S8.

In step S8, it is determined whether or not the blow mode is other than the full cool mode (the blow mode in which the amount of air passing through the heater 6 by the air mix door 7 is adjusted to zero). When the blowing mode is the full hot mode (YES), the process proceeds to step S9.

In step S9, the operation of the electric heater 10 is started. Since the electric heater 10 starts operating immediately after the internal combustion engine 20 stops, the time from when the temperature 51 of the air blown from the automotive air conditioner decreases to when it rises becomes short, and the air blown out Of the temperature 51 decreases (see FIG. 4).

Next, based on the information from the inside air temperature sensor 45, it is determined whether or not the temperature of the air blown out from the vehicle air conditioner has exceeded a predetermined value (step 10).
When the temperature of the air blown out from the automotive air conditioner is lower than the predetermined value (NO), the electric heater 10 is kept operating and step S10 is repeated again. When the temperature of the air blown from the automotive air conditioner exceeds a predetermined value (YES), the operation of the electric heater 10 is stopped (step 11), and the process returns to step S1.

If the answer in step S8 is negative (N
O), that is, when the blowing mode is the full cool mode, the process returns to step S1.

As described above, the temperature 51 of the air blown out of the vehicle air conditioner can be reduced in a short time by the internal combustion engine 2.
0 recovers to a predetermined value before the stop (the set value of the temperature of the air blown out from the automotive air conditioner). Further, the electric heater 10 is stopped when the temperature 51 of the blown air exceeds a predetermined value.
1 does not rise significantly from the predetermined value, and the predetermined value is maintained.

If the answer in step S2 is affirmative (YE
S), that is, while the internal combustion engine 20 is operating, it is determined whether or not the blowing mode is other than the full cool mode (step S3).

When the answer to step S3 is affirmative (YES), that is, when the blowing mode is other than the full cool mode,
It is determined whether the temperature of the engine cooling water is equal to or lower than a predetermined value (step S4).

When the answer to step S4 is affirmative (YES), that is, when the temperature of the engine cooling water is equal to or lower than a predetermined value,
The hot water heater 10 is operated (step S5).

Thereafter, it is determined whether or not the blow mode is other than the full cool mode (step S6). When the answer is affirmative (YES), that is, when the blow mode is other than the full cool mode, the temperature of the engine cooling water is determined. Is smaller than or equal to a predetermined value (step S7).

When the answer to step S7 is affirmative (YES), that is, when the temperature of the engine cooling water is equal to or lower than a predetermined value,
Returning to step S1, the above control is repeated.

When the answer in steps S1, S3 and S4 is negative (NO), the process returns to step S1.

If the answer to steps S6 and S7 is negative (NO), the process proceeds to step S11, where the operation of the hot water heater 10 is stopped, and the process returns to step S1. When the blowing mode is the full cool mode, heating by the heater 6 is unnecessary, and the same is true when the temperature of the engine cooling water is equal to or higher than a predetermined value. Therefore, the operation of the electric heater 10 is stopped and the electric heater is stopped. 10 wasteful heating can be prevented.

According to this embodiment, the occupant hardly feels a drop in the temperature 51 of the air blown out from the vehicle air conditioner, so that the drop in the blown air temperature during heating is suppressed.
Comfort can be improved.

Further, since the temperature 51 of the air blown out from the vehicle air conditioner can be maintained at a predetermined value or less, the comfort is not impaired.

When air is not passed through the heater 6 at all in the full cool mode, the electric heater 1
Since 0 does not wastefully heat, an energy saving effect is obtained.

In this embodiment, the case where the vehicle air conditioner of the present invention is mounted on a hybrid vehicle has been described. However, the present invention can be mounted not only on a hybrid vehicle but also on a gasoline engine vehicle used in cold regions.

[0060]

As described above, according to the automotive air conditioner of the first aspect of the present invention, it is possible to suppress a decrease in the temperature of the blown air during heating and to improve comfort.

According to the vehicle air conditioner of the second aspect of the present invention, the temperature of the blown air can be kept substantially constant, so that comfort is not impaired.

According to the vehicle air conditioner of the third aspect, an energy saving effect can be obtained.

[Brief description of the drawings]

FIG. 1 is a block diagram of an air conditioner for a vehicle according to an embodiment of the present invention.

FIG. 2 is a diagram for explaining a heater.

FIG. 3 is a sectional view taken along line III-III in FIG. 2 (a).

FIG. 4 is a diagram for explaining an automotive air conditioner.

FIG. 5 is a flowchart for explaining a method of operating an electric heater by a control unit.

FIG. 6 is a diagram for explaining a conventional automobile air conditioner.

[Explanation of symbols]

 7 Air mix door 9 Hot water heater 10 Electric heater 20 Internal combustion engine 40 Control unit (control means)

Claims (3)

[Claims] 1. An automotive air conditioner comprising: a hot water heater using a cooling water of an internal combustion engine as a heat source; and an electric heater for supplementing a heating capacity of the hot water heater. An air conditioner for a vehicle, comprising: control means for starting the operation of the electric heater when the internal combustion engine stops. 2. The automotive air conditioner according to claim 1, wherein the control unit stops the operation of the electric heater when the temperature of the electric heater exceeds a predetermined value. 3. The electric heater according to claim 1, wherein the control means stops the operation of the electric heater when the amount of air passing through the hot water heater is adjusted to zero by an air mixing door. The air conditioner for a vehicle according to the above.