JPH10297273A - Air conditioner for automobile - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an air conditioner for automobile excellent in temperature adjustment characteristics in a compartment by controlling a temperature of the air blown into the compartment by one heat exchanger on indoor side to heat and cool the compartment. SOLUTION: A supply piping 4 and a return piping 5 are connected an between indoor side heat exchanger 2 which controls the temperature of the air blown into a compartment PR and an engine 1, a bypass piping 6 is connected between the return piping 5 and the supply piping 4, a flow closing passage which bypasses the engine cooling water flowing out of the heat exchanger on indoor side 2 into the return piping 5 into the supply piping 2 without returning the engine cooling water to an engine side is formed, and a heater exchange part 16 formed in the bypass flow passage is arranged in an evaporator 15 which constitutes air conditioning cycle to heat and cool the compartment PR by the indoor side heat exchanger 2.

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 an automobile, in which heating and cooling of air blown into a vehicle compartment is performed by a single heat exchanger to control the temperature of the vehicle compartment to a desired temperature. Related to the device.

[0002]

2. Description of the Related Art Generally, an air conditioner for an automobile has an evaporator (cooler) for cooling air and a heater core (heater) through which high-temperature engine cooling water flows, and the heater / cooler is controlled by a control method. There are an independent system, a heater / cooler switching system, a semi-air conditioner system, a full air conditioner system, and a reheat system.

In the independent heater / cooler system, an evaporator and a heater core are independently arranged, and only the evaporator or the heater core is used at the time of air distribution.

[0004] The heater / cooler switching system is similar in function to the heater / cooler independent system, but is a type in which the use of an evaporator or a heater core is selected by a switching door provided at an outlet. is there.

[0005] In the semi-air conditioner system, all air is guided to an evaporator, and is blown out without passing through a heater core during cooling, and the air cooled and dehumidified by the evaporator is heated during heating to control the flow rate of hot water flowing through the heater core. It is a type that warms more.

[0006] The full air conditioner system is also called an air mix system, in which air that has passed through an evaporator is branched into air that enters a heater core and air that does not enter, and both airs are mixed in front of an outlet. It is.

In the reheat method, all air passing through an evaporator is passed through a heater core (in which the flow rate of hot water flowing through the core is adjusted), heated again, and then supplied from each outlet into the vehicle interior. It is a type that was made.

[0008] At present, of these systems, the full air conditioner system is frequently used.

[0009]

In the aforementioned air conditioner for a full air-conditioner type vehicle, the evaporator is incorporated in the cooler unit, and the heater core is incorporated in the heater unit. The taken-in air is first cooled by an evaporator and then heated by a heater core for dehumidification.

In the full air conditioner system, an air mixing door is required to adjust the ratio of the air passing through the evaporator to the air entering the heater core and the air not entering the heater core, but the reheating system does not require such a door. There are advantages. However, in the reheat method, the temperature of the vehicle interior is controlled by adjusting the amount of engine cooling water flowing through the heater core. Therefore, when it is not necessary to increase the heating capacity as in the case of the intermediate period, the heater core is heated. It is necessary to reduce the amount of the engine cooling water supplied to the heater core, and the temperature distribution of the engine cooling water in the heater core varies.

For this reason, there is a problem that a temperature difference occurs between the outlets into the vehicle compartment and the temperature control characteristics cannot be improved.

In many air conditioners for automobiles, an intake unit, a cooler unit, and a heater unit are connected in series in the vehicle width direction in this order, so that a large installation space is required. In addition, since three unit cases are separately required, the number of parts is large, and it is difficult to reduce the cost.

The present invention controls the temperature of the air blown into the vehicle interior by one heat exchanger to perform heating and cooling of the vehicle interior, thereby providing a vehicle air with excellent temperature control characteristics in the vehicle interior. It is intended to provide a harmony device.

[0014]

In order to achieve the above object, an invention according to a first aspect of the present invention is directed to an inlet of an indoor heat exchanger for controlling a temperature of air blown into a vehicle interior and an engine cooling water flow. A supply pipe for supplying engine cooling water heated by an engine to the indoor heat exchanger is connected between the outlet and the outlet, and between the outlet of the indoor heat exchanger and the engine cooling water inlet. Connecting a return pipe for returning the engine cooling water flowing out of the indoor heat exchanger to the engine side, and connecting a bypass pipe between the return pipe and the supply pipe; Forming a closed flow path for bypassing the engine cooling water flowing out of the cooler into the supply pipe without returning the engine cooling water to the engine side. Place a replacement unit in the room Characterized in that to perform the passenger compartment heating and the cooling by the heat exchanger.

With this configuration, the temperature of the air blown into the vehicle interior by one indoor heat exchanger can be controlled to perform heating and cooling of the vehicle interior, so that the air conditioner for an automobile can be realized. Can be greatly reduced in the installation space in the vehicle for the equipment constituting the vehicle. Further, it is possible to eliminate a refrigerant pipe extending between the vehicle compartment and the engine room.

According to the second aspect of the present invention, by controlling the temperature of the heat medium supplied to the indoor heat exchanger, it is possible to prevent the temperature distribution in the indoor heat exchanger from fluctuating. It is possible to prevent a temperature difference between the air blown into the vehicle compartment from each outlet. Furthermore, the practical application of the reheat-type automotive air conditioner is achieved.

According to the third or fourth aspect of the present invention, the flow rate of the heat medium flowing through the indoor heat exchanger is blown into the vehicle interior by controlling the operation of a flow control valve and a circulation pump. The temperature of the air can be set to any temperature.

According to a fifth aspect of the present invention, a return pipe is provided between an engine cooling water outlet and an engine cooling water inlet, and a drive unit driven by the engine cooling water flowing in the return pipe is provided with a circulation pump. And the driving unit drives the circulating pump.

According to this configuration, since the circulation pump is driven using the flow of the engine cooling water as a driving force, a special driving mechanism is not required, and a compact air conditioner having a simple structure can be obtained.

According to a sixth aspect of the present invention, there is provided a heating mode in which the engine cooling water is supplied from the supply pipe to the heat exchanger and then returned to the engine via the return pipe, and the heat exchanger is connected via the bypass pipe. And a control means for switching control to a cooling mode in which the heat medium in the inside is circulated in the closed flow path without returning to the engine side.

In this manner, the mode is automatically switched to the heating mode or the cooling mode, and the interior of the vehicle can be maintained at the predetermined temperature set by the occupant.

[0022]

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

FIG. 1 is a schematic diagram showing an automotive air conditioner according to an embodiment of the present invention. This automotive air conditioner has an engine cooling water cycle E in which high-temperature engine cooling water heated by the engine is circulated by a circulation pump P, and a cooling cycle R in which refrigerant circulates.

First, in the cooling water cycle E, an outlet 2b of the indoor heat exchanger 2 and an engine 2 are connected by a supply pipe 4 between the outlet 1a of the engine 1 and the inlet 2a of the indoor heat exchanger 2. It is connected to the inflow port 1b on one side by a return line 5. Therefore, only the piping through which the cooling water flows through the indoor heat exchanger 2 is present in the passenger compartment PR, and most of the other devices are present in the engine room ER. It is characterized in that the refrigerant pipe does not exist in the vehicle compartment PR as in the air conditioner for automobiles.

In the cooling water cycle E, a bypass pipe 6 is connected between the connecting portion 4a and the connecting portion 5a,
By the bypass pipe 6, the engine cooling water flowing out of the indoor heat exchanger 2 is returned to the indoor heat exchanger 2 via the supply pipe 4 without returning to the engine 1.

A return line 7 is connected between the connecting portion 5b and the connecting portion 4b provided on the engine 1 side with respect to the connecting portion 5a. The engine cooling water discharged from the side is returned to the engine side again without being guided to the indoor heat exchanger 2.

The supply pipe 4 is provided with a flow regulating valve 8 between the connecting portions 4a and 4b to control the flow rate of the engine cooling water flowing through the supply pipe 4 and flowing into the indoor heat exchanger 2. doing. A circulation pump P is provided in the supply pipe 4 in order to control the flow rate of the engine coolant flowing into the indoor heat exchanger 2 in addition to the flow control valve 8 in the supply pipe 4. Alternatively, the flow rate may be controlled only by the circulation pump P.

On the other hand, a cooling cycle R is arranged in a compressor 11 and an engine room ER driven by the engine 1 and a fan 13 as in a normal cooling cycle.
It has a condenser 12, an expansion valve 14, and a cooler 15, which are cooled by the like.

The compressor 11 used here may be a fixed displacement compressor or a variable displacement compressor.

A heat exchange section 16 is provided in the cooler 15 so as to exchange heat between the engine cooling water flowing in the supply pipe 4 and the refrigerant flowing in the cooling cycle R. The heat exchange section 16 may be, for example, a meandering pipe line 4 as shown in the figure. However, in order to further enhance the heat exchange efficiency, heat exchange in a heat exchanger such as a so-called intercooler is required. It is preferable to use one provided with an exchanger. However, the present invention is not limited to this, and may employ another system.

The position of the heat exchange section 16 is provided in the supply pipe 4 in the illustrated case. However, if the section forms a closed flow path, the bypass pipe 6 and the return pipe 5 may be provided between the outlet 2b and the connecting portion 5a. Regarding the bypass line 6, an on-off valve for opening and closing the passage may be provided.

Next, the operation will be described. When heating the interior of the passenger compartment PR, the clutch (not shown) provided between the engine and the compressor 11 is disengaged, the operation of the compressor 11 is stopped, and the circulating pump P is driven to cool the engine. Water is supplied from the supply pipe 4 to the indoor heat exchanger 2
Supply within. The supply amount of the engine cooling water is controlled by the opening of the flow control valve 8, whereby a predetermined amount of the engine cooling water is introduced into the indoor heat exchanger 2.

In the indoor heat exchanger 2, since the air outside the vehicle compartment is introduced by the fan 3, the heat of the high-temperature engine cooling water and the air exchange heat and is blown into the vehicle compartment PR. The engine coolant flowing out of the outlet 2b of the indoor heat exchanger 2 returns to the engine 1 through the return pipe 5 through the inlet 1b on the engine 1 side.

FIG. 4 is a graph showing the opening of the flow control valve 8 during heating and during cooling. As shown in FIG. 4, the temperature of the blown air blown into the vehicle compartment PR is:
An arbitrary temperature is set according to the opening degree of the flow control valve 8. When the heating capacity is set to the maximum, that is, at the time of full hot, the opening of the flow control valve 8 is controlled to be fully opened, and a large amount of engine cooling water flows through the indoor heat exchanger 2, and the air to be heated thereby is heated. Becomes high temperature corresponding to full hot.

In the heating mode H other than the full hot mode, the opening degree of the flow control valve 8 is set in accordance with the temperature set by the occupant operating the controller provided in the passenger compartment PR. It is automatically controlled, so that the air matches the set temperature. The flow control valve 8 is closed both in the cooling mode M at an intermediate temperature (for example, about 25 ° C.) and in a cooling mode C at a lower temperature, which will be described later.

In the case where the operation of the circulation pump P is controlled without using the flow control valve 8 or together with the use of the flow control valve 8, a predetermined amount of engine cooling water is surely supplied to the indoor heat exchanger 2.
The operation of the circulation pump P is controlled at the timing shown in FIG.

Next, when cooling the interior of the passenger compartment PR, the flow control valve 8 is fully closed, and the engine cooling water flowing out of the outlet 1a is returned to the engine side by the return line 7 and is returned to the engine side. It is not supplied to the inner heat exchanger 2. However, since the circulation pump P is driven, the circulation pump P →
The engine cooling water in the closed flow path formed by the heat exchange section 16 → the indoor heat exchanger 2 → the return pipe 5 → the bypass pipe 6 flows through the closed flow path as a heat medium.

In this state, when the clutch is engaged and the compressor 11 is driven by the engine, a well-known cooling cycle R is operated, and a low-temperature and low-pressure refrigerant flows through the cooler 15. Therefore, the heat medium of the engine cooling water flowing through the heat exchange section 16 in the cooler 15 is:
Cooled by the refrigerant, it is supplied to the indoor heat exchanger 2 as a low-temperature heat medium, and the indoor air is cooled. By controlling the temperature of the heat medium, the temperature of the air blown into the passenger compartment PR can be controlled to an arbitrary temperature.

FIG. 5 is a graph showing the temperature state of the engine cooling water, that is, the heat medium, during heating and during cooling.
By controlling the flow rate of the circulation pump P, the cooling temperature can be controlled as shown by the solid line in FIG. Here, assuming that the temperature of the heat medium at the engine coolant outlet 1a is E, the temperature of the heat medium flowing into the indoor heat exchanger 2 is controlled by controlling the opening of the flow control valve 8 with this temperature E as the maximum temperature. Can be set to any temperature. If an antifreeze liquid that does not freeze even at 0 ° C. or less is used as engine cooling water, the temperature of the heat medium can be reduced to 0 ° C.
It can also be set to below ° C.

However, the control of the temperature of the blown air can be changed by the air volume and the temperature of the heat medium.
The temperature of the vehicle interior air may be controlled by both the air volume and the temperature of the heat medium. That is, this means that the vehicle air conditioner can perform two types of control.

The first control method is a method of changing the temperature of the heat medium. For example, it can be used to change the discharge amount from the compressor by using a variable displacement compressor, but as shown by the solid line in FIG. 5, the temperature of the heat medium is changed so as to gradually decrease. When the air volume is changed so that it gradually decreases,
While maintaining the temperature of the vehicle interior air at a predetermined value, the control width of the air volume blown into the vehicle interior PR can be adjusted.

In the case where the temperature of the heat medium flowing through the closed flow path is varied as described above, if the temperature of the heat medium is increased while the cooling load is small, the air volume can be secured while suppressing a decrease in the blow-out temperature. The temperature distribution in the passenger compartment PR can be improved.

The second control method is a method of changing the air volume. For example, it can be used when a fixed displacement compressor is used and the discharge amount from the compressor is constant, but when the temperature of the heat medium is kept constant as shown by a broken line in FIG. Is the passenger compartment PR
Temperature control can be performed by controlling the amount of air blown into the inside. As described above, when a heat medium having a constant temperature is circulated, the blowing temperature of the cool air is controlled by the air volume. The larger the air volume, the higher the cooling capacity, and the smaller the air volume, the lower the blowing temperature.

In the case of the first method of controlling the temperature of the heat medium, a method of controlling the temperature of the heat medium by controlling the cooling cycle on / off may be used. It is preferable to use a variable displacement compressor capable of performing control, or to control the amount of refrigerant flowing through the cooling cycle by using an electronic expansion valve, because it is more stable and energy saving can be ensured.

FIG. 6 is a block diagram showing a control circuit for controlling the operation of the air conditioner for a vehicle.
0, a liquid temperature sensor 21 for detecting the temperature of the heat medium in the indoor heat exchanger 2, a solar radiation sensor 22 for detecting the amount of solar radiation applied to the vehicle, and a vehicle room temperature sensor for detecting the temperature in the passenger compartment PR. 23, a detection signal from an outside air temperature sensor 24 for detecting the temperature outside the vehicle is sent, and furthermore, a signal of the set temperature inputted by the occupant operating a temperature setting unit 25 provided in the controller. Is sent to the control unit 20.

An operation signal is sent from the control unit 20 to the flow regulating valve 8 and the circulating pump P. Further, a control signal for controlling the operation of the electronic expansion valve 14 and the rotation speed of the fan 3 Control signal for controlling the amount of air blown into the passenger compartment PR by controlling the
The control signals for controlling the operation of the
It is sent from.

When a fixed displacement compressor is used as the compressor 11, the on-off control of the compressor clutch and the control of the amount of air blown into the passenger compartment PR control the temperature of the passenger compartment during cooling. .
When a variable displacement compressor is used, the vehicle interior temperature during cooling is controlled by controlling the electronic expansion valve 14 and controlling the air volume.

FIG. 7 is a flowchart showing the operation procedure of the air conditioner for a vehicle performed by the control circuit shown in FIG.

First, when the air conditioner for a vehicle is started, initialization is performed by a CPU or the like in the control unit 20 in step S1. Next, in step S2, detection values from each sensor such as the liquid temperature sensor 21 are read, and in steps S3 to S7, respective correction values are calculated, and the heat medium to be supplied into the indoor heat exchanger 2 is calculated. Is set in step S8.

It is determined in step S9 whether to heat or cool the interior of the passenger compartment PR according to the set temperature. If it is determined in step S9 that the air conditioner is in the cooling mode, the air conditioner enters the cooling mode. In step S10, the flow regulating valve 8 is closed, and devices such as the compressor 11 that constitute a cooling cycle are operated.

On the other hand, if it is determined that heating is to be performed, the operation of the compressor 11 is stopped, and the opening of the flow control valve 8 is controlled in step S11.

FIG. 2 is a view showing an air conditioner for a vehicle according to another embodiment of the present invention. In this case, an impeller rotationally driven by engine cooling water flowing through the return line 7 is provided. A driving unit T is provided, and the circulation pump P is driven by the rotation of the driving unit T. Therefore, in this case, the return line 7 is used as a drive source for driving the circulation pump P.
Since the liquid flowing through the pump is used, the circulating pump P can be driven without providing an external driving means, so that the structure of the pump can be reduced in weight and size, and a circulating pump which is hard to break down and has excellent durability can be obtained.

FIG. 3 is a view showing an air conditioner for a vehicle according to still another embodiment of the present invention. In this case, an engine is connected to a return line 5 from an outlet 2b of an indoor heat exchanger 2 through an engine. A check valve 9 is provided to allow the flow toward the inflow port 1b on the one side and to prevent the flow in the opposite direction. This check valve 9 may be provided also in the case shown in FIG.

In FIGS. 2 and 3, members common to those shown in FIG. 1 are denoted by the same reference numerals.

[0055]

As described above, according to the present invention, 1
By arranging the two heat exchangers in the vehicle compartment, heating and cooling of the vehicle compartment can be performed, so that the space occupied by the vehicle air conditioner can be effectively used.

Heating and cooling of the vehicle interior can be performed by one heat exchanger, so that the number of components of the components of the air conditioner for a vehicle can be reduced, and the space occupied in the vehicle interior can be reduced. As a result, an inexpensive heat exchanger can be provided, and the entire system becomes compact. By controlling the temperature of the heat medium supplied to the heat exchanger,
Variations in the temperature distribution of the heat medium in the heat exchanger can be prevented, and a temperature difference from each outlet into the vehicle compartment can be prevented.

Further, since there is no refrigerant pipe in the vehicle cabin, assembly becomes easy, maintenance is excellent, and product quality and serviceability are improved.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing an embodiment of the present invention.

FIG. 2 is a schematic view showing another embodiment of the present invention.

FIG. 3 is a schematic view showing still another embodiment of the present invention.

FIG. 4 is a graph showing the opening of a flow control valve during heating and during cooling.

FIG. 5 is a graph showing the temperature of the heat medium during heating and during cooling.

FIG. 6 is a block diagram showing a control circuit according to the embodiment of the present invention.

FIG. 7 is a flowchart showing a control procedure according to the embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Engine, 1a ... Engine cooling water outlet, 1b ... Engine cooling water inlet, 2 ... Indoor heat exchanger, 2a ... Inlet, 2b ... Outlet, 4 ... Supply line, 5 ... Return line, 6 ... Bypass line, 7 return line, 8 flow control valve, 9 check valve, 11 compressor, 12 condenser, 14 expansion valve, 20 control unit, ER engine room, PR cabin, R: Cooling cycle.

Claims (6)

[Claims] An engine (1) is provided between an inlet (2a) of an indoor heat exchanger (2) for controlling the temperature of air blown into a vehicle compartment (PR) and an engine cooling water outlet (1a). A supply pipe (4) for supplying the engine cooling water heated by (1) to the indoor heat exchanger (2) is connected, and the outlet (2b) of the indoor heat exchanger (2) and the engine cooling water are connected. A return line (5) for returning engine cooling water flowing out of the indoor heat exchanger (2) to the engine side is connected between the water inlet (1b) and the return line (5) and the supply line. A bypass pipe (6) is connected between the pipe and the pipe (4) so that the engine cooling water flowing from the indoor heat exchanger (2) to the return pipe (5) is not returned to the engine side. Forming a closed flow path for bypassing in the supply pipe line (4); disposing a heat exchange part (16) formed in the bypass flow path in a cooler (15) constituting a cooling cycle (R); Indoor heat exchange Vessel (2) automotive air conditioner being characterized in that to perform the heating and cooling of the inner casing (PR) by. 2. The heating and cooling in the vehicle compartment (PR) by varying the temperature of the heat medium supplied into the indoor side heat exchanger (2). 2. The automotive air conditioner according to 1. 3. The vehicle according to claim 1, further comprising a flow rate control means (P, 8) for controlling a flow rate of the heat medium supplied to the indoor heat exchanger (2). Air conditioner. 4. A circulating pump (P) for circulating a heat medium in the closed flow path is provided, and the indoor heat exchanger (2) is provided.
The vehicle air conditioner according to claim 1 or 2, wherein a flow rate of the heat medium supplied to the air conditioner is controlled. 5. A return pipe (7) is provided between an engine coolant outlet (1a) and an engine coolant inlet (1b), and is driven by the engine coolant flowing through the return pipe (7). The vehicle air conditioner according to claim 4, wherein a driving unit (T) is connected to the circulating pump (P), and the circulating pump (P) is driven by the driving unit (T). apparatus. 6. The return line after supplying engine cooling water from the supply line (4) to the indoor heat exchanger (2).
(5) A heating mode in which the heat medium is returned to the engine (1) through the bypass pipe (6), and the heating medium in the indoor heat exchanger (2) is returned to the engine (1) through the bypass pipe (6) without being returned to the engine (1). The air conditioner for a vehicle according to claim 1 or 2, further comprising control means (20) for switching control to a cooling mode for circulating in the flow path.