JPH0361115A - Vehicle air conditioning device - Google Patents

Abstract

PURPOSE:To circulate hot water maintained at a relatively low temperature at the time of room temperature, and secure the safety when the hot water is leaked off by sucking high temperature hot water heated by an internal combustion engine into a pump only when blow-off air is at low temperature, and heating the blow-off air by a heater core. CONSTITUTION:A pump 4 is driven to circulate hot water between a supply passage 22, a heater core 6, a delivery passage 23, and a bypass passage 26. The air passing in an air-passage 8 through an evaporator 10 is heated by the heater core 6. On the other hand, when the temperature of the hot water is lowered to reduce the blow-off temperature of the air passing through the heater core 6, a control valve 2 is opened by a control device 14 based on a detection signal of a blow-off temperature sensor 12. Thus, high temperature hot water heated by an internal combustion engine 1 is sucked through a suction passage 20 into a pump 4. Accordingly, the temperature of the circulating hot water can be held lower than the temperature of the hot water delivered from the internal combustion engine 1, and thereby the safety can be secured even when the circulating hot water is leaked off.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a vehicle air conditioner that supplies cooling water of an internal combustion engine as a heat exchange fluid to a heater core and heats the heat exchange fluid.

[Prior Art] Conventionally, reheat type air conditioners have been commonly used in buses and the like as vehicle air conditioners.

For example, as stated in Japanese Patent Application Laid-Open No. 63-87306,
Air that has been dehumidified and cooled by an evaporator is reheated to a predetermined temperature by a heater core.

Reheating in the heater core is performed by supplying hot water, which is the heat exchange fluid heated by the internal combustion engine, to the heater core via a control valve using a pump, and heating the air, which is the heat exchange fluid, that passes through the heater core. There is. The temperature of the heated air was adjusted by adjusting the opening degree of the control valve to adjust the flow rate of hot water supplied to the heater core. In other words, as shown in FIG. Hot water can be sucked into a pump 4 via a control valve 2, and the discharge side of the pump 4 is connected to a heater core 6. The heater core 6 and the internal combustion engine are communicated with each other to return hot water to the internal combustion engine. An evaporator 10 is provided on the upstream side thereof to send out dehumidified and cooled air. A blowout temperature sensor 12 is disposed on the downstream side to detect the temperature of the air that has passed through the heater core 6 and is heated. The temperature signal detected by this blowout temperature sensor 12 is input to the control device 14, and the opening degree of the control valve 2 is controlled by the control device 14.
4, air heated to a desired temperature is blown into the vehicle interior as warm air.

[Problems to be solved by the invention] However, with these conventional vehicle air conditioners,
High-temperature hot water heated by the internal combustion engine 1 is directly supplied to the heater core 6 . Therefore, when applied to a bus, a plurality of heater cores 6 are generally installed near the ceiling of the vehicle, and high-temperature hot water is supplied to each heater core 6 through the ceiling. The fact that high-temperature hot water passes through the ceiling of a bus in this way is not necessarily desirable, and there are points that need to be improved. Aiming to solve problems,
An object of the present invention is to provide a vehicle air conditioning system that takes safety into account.

[Means for Solving the Problems] In order to achieve the above objectives, the present invention adopts the following configuration as a means for solving the problems. In a vehicle air conditioner equipped with a pump that supplies heat exchange fluid, a circulation flow path is formed to draw the heat exchange fluid that has passed through the heater core into the pump and supply it to the heater core again, and the pump is controlled. A vehicle for use in a vehicle, characterized in that the fluid to be heat exchanged heated by the internal combustion engine can be sucked in through a valve, and has a return flow path for returning a portion of the fluid to be heat exchanged that has passed through the heater core to the internal combustion engine. This is the configuration of the air conditioner.

[Function] In the vehicle air conditioner having the above configuration, the pump supplies the heat exchange fluid to the heater core, and sucks the heat exchange fluid that has passed through the heater core into the pump through the circulation flow path, and the pump supplies the heat exchange fluid to the heater core. Circulating the heat exchanged fluid between the pumps. Then, the control valve allows the heat exchange fluid heated by the internal combustion engine to be sucked into the pump according to the temperature of the heat exchange fluid, and a part of the heat exchange fluid that has passed through the heater core via the return flow path. Return to internal combustion engine. Therefore, the heat exchange fluid supplied to the heater core is not directly supplied with the heat exchange fluid heated by the internal combustion engine, but is supplied with the heat exchange fluid circulating in the circulation flow path. The temperature can be kept low.

[Example] Embodiments of the present invention will be described in detail below based on the drawings.

FIG. 1 is a schematic circuit diagram of a vehicle air conditioner which is an embodiment of the present invention. Components that are the same as those in the conventional apparatus shown in FIG.

The hot water discharge side of the internal combustion engine 1 and the suction side of the pump 4 are connected by a suction passage 20 in which a control valve 2 is installed, so that hot water heated by the internal combustion engine 1 as a heat exchange fluid can be sucked. is being used. Further, the discharge side of the pump 4 is communicated with the inlet side of the heater core 6 through a supply flow path 22,
One end of a discharge flow path 23 is connected to the outlet side of the heater core 6 .

A return flow path 24 connected to the hot water suction side of the internal combustion engine 1 and a bypass flow path 26 connected to the suction side of the pump 4 are connected to the other end of the discharge flow path 23 . The supply flow path 22, the discharge flow path 23, and the bypass flow path 26 form a circulation flow path for sucking hot water that has passed through the heater core 6 into the pump 4 and supplying it to the heater core 6 again.

The bypass flow path 26 has a predetermined flow path resistance 28,
The hot water passing through the heater core 6 and flowing through the discharge passage 23 can be divided into a return passage 24 and a bypass passage 26 .

The flow path resistance 28 may be configured by piping resistance of the bypass flow path 26, or a crest valve or the like may be provided in the bypass flow path 26. Note that instead of providing the flow path resistance 28 in the bypass flow path 26, it is also possible to provide a predetermined flow path resistance in the return flow path 24. The flow path resistance to be provided in which direction may be appropriately determined by considering the arrangement of the heater core 6, the piping resistance of each flow path, and the like.

On the other hand, on the downstream side of the heater core 6, a blowout temperature sensor 12 is disposed to detect the temperature of the air that has passed through the heater core 6 and is heated. The temperature signal detected by this blowout temperature sensor 12 is input to a control device 14, as shown in FIG. Then, the preset blowout temperature and the detected temperature signal are compared, and if the detected temperature is low, the i-control device 141
By energizing the coil 32 of the relay 30,
It is configured to close the contact 34 of the relay 30 and open the control valve 2. The control valve 2 may be a simple on-off valve, but may also be a flow rate regulating valve that can adjust its flow rate in accordance with the excitation current output from the control device 14 in accordance with the level of the detected temperature.

When the above-mentioned vehicle air conditioner is applied to a bus, as shown in FIG. A blowout temperature sensor 12 is disposed corresponding to the heater core 6 of each card. In addition, each hita core 6 is connected in series, and the pump 4
The hot water discharged from the heater core 6 is supplied to the first heater core 6 via the supply channel 22, and is then sequentially supplied to the pot heater core 6. Then, from the last heater core 6 to the discharge flow path 23
The internal combustion engine 11 is configured to be returned to the pump 4 via the bypass flow path 26, and to the internal combustion engine 11 via the discharge flow path 23 and the return flow path 24.

Next, the operation of the vehicle air conditioner of this embodiment will be explained using an example in which it is applied to the bus.

First, when the internal combustion engine 1 is started, the temperature of the internal combustion engine 1 is low, and the hot water in each heater core 6, supply flow path 22, discharge flow path 23, bypass flow path 26, return flow path 24, etc. The temperature is also low. 8- When the temperature of the internal combustion engine 1 rises, hot water of sufficient temperature is supplied.

On the other hand, when the pump 4 is driven, hot water is supplied to each heater core 6 via the supply channel 22. The hot water that has passed through the heater core 6 is sucked into the pump 4 again via the discharge passage 23 and the bypass passage 26 and is supplied to each heater core 6 . In this way, when the control valve 2 is closed, hot water is supplied to the pump 4, the supply channel 22, the heater core 6, the discharge channel 23,
It circulates between the bypass channels 28.

Furthermore, the air flowing through the ventilation channel 8 is first dehumidified and cooled by the evaporator 10, but when it passes through the heater core 6, heat is exchanged between the hot water supplied to the heater core 6 and the cooled air. The heated air becomes hot air and is blown into the bus interior.

The temperature of the air blown out is detected by a blowout temperature sensor 2, and the temperature signal is input to the control device 14. When this temperature signal is lower than a predetermined temperature, the control device 14 causes the coil 32 of the relay 30 to
is energized, control valve 2 is opened. When the control valve 2 is opened, high-temperature hot water heated by the internal combustion engine 1 is supplied to the suction side of the pump 4 via the suction passage 20. Therefore, the high temperature hot water supplied from this suction flow path 20,
The water is mixed with the hot water supplied from the circulation channel 28 and sucked into the pump 4. Then, a portion of the cooled hot water circulating between the pump 4, the supply channel 22, the heater core 6, the discharge channel 23, and the bypass channel 28 is adjusted according to the amount of newly supplied high-temperature hot water. is returned to the internal combustion engine 1 via the return passage 24.

As a result, the temperature of the hot water sucked into the pump 4 increases. Then, when this hot water is supplied to the heater core 6 via the supply channel 22, the temperature of the air passing through the heater core 6 rises, and when it reaches a predetermined temperature, the relay 30 is de-energized and the control valve 2 is activated. The valve is closed.

When the control valve 2 closes, hot water flows through the pump 4 and the supply channel 2.
2. It circulates between the heater core 6, the discharge flow path 23, and the bypass flow path 28. Then, heat exchange is performed between the circulating hot water and the air to heat the air. This pump 4, supply channel 22, heater core 6, discharge channel 23, bypass channel 2
The hot water circulating between the two heaters heats the air passing through the heater and blows the warmed air into the passenger compartment.

At this time, if the amount of hot water circulating between the pump 4, the supply channel 22, the heater core 6, the discharge channel 23, and the bypass channel 28 is sufficient, the circulating hot water can
-Can temporarily warm the air.

When the temperature of the circulating hot water drops and the air cannot be sufficiently warmed, and the temperature of the air flowing through the heater core 6 drops below a predetermined temperature, the control valve 2 is opened and the internal combustion Supply high temperature hot water from engine 1. As a result, the temperature of the hot water circulating between the pump 4, the supply channel 22, the heater core 6, the discharge channel 23, and the bypass channel 28 increases, and the temperature of the hot water flowing through the heater core 6 also increases.

1. Therefore, the amount and temperature of the hot water circulating between the pump 4, the supply flow path 22, the heater core 6, the discharge flow path 23, and the bypass flow path 28 are such that the air is heated and the blowing temperature that passes through the heater core 6 is maintained at a predetermined temperature. It is sufficient that the temperature can be increased to a level higher than the temperature. If the amount of hot water that circulates is 1 minute, the hot water has enough heat to warm the air even if the temperature is low.

Therefore, this pump 4, supply channel 22, heater core 6,
The temperature of the hot water circulating between the discharge flow path 23 and the bypass flow path 28 does not require that the high-temperature hot water from the internal combustion engine 1 be circulated at the same temperature; it is sufficient to lower the temperature of the circulating hot water. It can warm the air.

In this manner, the vehicle air conditioner described above circulates hot water between the pump 4, the supply channel 22, the heater core 6, the discharge channel 23, and the bypass channel 28, and heats the air with the heater core 6. When the temperature of the hot water decreases and the barking temperature passing through the heater core 6 decreases, the control valve 2 is opened.
The suction channel 20 receives high-temperature hot water heated by the internal combustion engine.
It is sucked into the pump 4 through 2-. Due to this (2), the temperature of the hot water supplied to the heater core 6 rises, and the blowout temperature also rises.Also, when the blowout temperature exceeds a predetermined temperature,
Control valve 2 is closed.

Therefore, the temperature of the hot water flowing between the pump 4, the supply channel 22, the heater core 6, the discharge channel 23, and the bypass channel 28 can be lower than the temperature of the high-temperature hot water discharged from the internal combustion engine 1. . Therefore, for some reason, pump 4
, offering! Even if hot water leaks from between the 8 flow path 22, the hita core 6, the discharge flow path 23, the bypass flow path 28, etc., the temperature of the hot water is low.

In particular, since the supply flow path 22, heater core 6, discharge flow path 23, etc. are provided on the ceiling of the bus, even if hot water leaks from the ceiling of the bus, the temperature of the hot water will be low, which is preferable for safety.

Next, a vehicle air conditioner according to a second embodiment will be explained with reference to FIG. Components that are the same as those in the embodiment described above are designated by the same numbers and detailed explanations will be omitted.

This is an accumulator 3 that stores hot water in the supply channel 22.
0 is inserted. Thereby, the heat capacity of the hot water circulating between the pump 4, the supply channel 22, the heater core 6, the discharge channel 23, and the bypass channel 28 can be increased. Therefore, the time during which air can be warmed only by the circulating hot water becomes longer, the frequency of opening and closing of the control valve 2 can be reduced, and hunting of the control valve 2 can be prevented. Note that the accumulator 30 can be similarly implemented even if it is provided in the return flow path 24 or the bypass flow path 28.

In addition, in this embodiment, the case where the heater core 6 is installed on the ceiling is taken as an example, but this is not limited to this case.Even if the heater core 6 is installed on the floor etc., hot water may leak for some reason. In some cases, it is preferable for safety that the temperature is low.

The present invention is not limited to these embodiments in any way, and may be implemented in various forms without departing from the gist of the present invention.

[Effects of the Invention] As described in detail above, the vehicle air conditioner of the present invention can prevent heat exchange even if the fluid to be heat exchanged, which is generally supplied to the heater core provided on the ceiling of a bus or the like, leaks for some reason. The temperature of the hot water is low, which prevents harm caused by the high temperature of the hot water and is advantageous in terms of safety.

[Brief explanation of drawings]

FIG. 1 is a schematic circuit diagram of a vehicle air conditioner as an embodiment of the present invention, FIG. 2 is a circuit diagram of an electrical system of this embodiment, and FIG.
The figure is a layout diagram as an example of applying the present invention to a bus.
FIG. 4 is a schematic circuit diagram of a vehicle air conditioner according to a second embodiment, and FIG. 5 is a schematic circuit diagram of a conventional vehicle air conditioner. 1... Internal combustion engine 2-... Control valve 4...
Pump 6... Heater core 14... Control device 22... Supply channel 23... Discharge channel 24... Return channel 26... Bypass channel

Claims (1)

[Scope of Claims] A vehicle air conditioner including a pump that supplies heat exchange fluid to a heater core disposed in a flow of heat exchange fluid, wherein the heat exchange fluid that has passed through the heater core is pumped to the heater core. A circulation flow path is formed to supply the heat exchange fluid heated by the internal combustion engine to the pump via a control valve, and the heat exchange fluid that has passed through the heater core can be sucked into the pump through a control valve. A vehicle air conditioner characterized by having a return flow path for returning a portion of exchange fluid to an internal combustion engine.