JP2008094340A - Air conditioner for vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent a refrigerant leaking from an air conditioner from flowing into a cabin. <P>SOLUTION: This air conditioner for a vehicle feeding the air heat-exchanged with the refrigerant by an evaporator 4 disposed in an air conditioner casing 1 into the cabin comprises a leakage detection means for detecting the leakage or the possibility of the leakage of the refrigerant from the evaporator 4 and an intake door 2 and mode doors 10, 11, 12 isolating at least the refrigerant leaking into the air conditioner casing 1. The refrigerant leaking from the evaporator 4 and isolated from the intake door 2 and the mode doors 10, 11, 12 is sucked into a negative pressure area on the intake side where a negative pressure is produced by the sucking operation of an engine through an opened suction passage 13. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a vehicle air conditioner that suppresses inflow of refrigerant into a passenger compartment when the refrigerant leaks from the air conditioner.

  Conventionally, as this type of technology, for example, those described in the following documents are known (see Patent Document 1). In this document 1, a shutter door for closing the air passage is provided on the downstream side of the air flow of the evaporator, a discharge door for opening and closing the discharge port is provided on the upstream side of the air flow from the shutter door, and the air blown from the blower is evaporated. A bypass door that opens and closes a bypass passage that bypasses the heater and leads to the heater is provided. When refrigerant leaks from the evaporator into the air conditioning casing, the blower is closed with the shutter door closed and the discharge port and bypass passage open. A technique is disclosed in which the refrigerant leaking from the evaporator is discharged to the outside by operating the.

  Further, in the literature 1, as a vehicle air conditioner improved in the above technique, a discharge door that opens and closes a discharge port that communicates the inside and outside of the first air passage from the blower to the evaporator is provided to evaporate the air blown from the blower When a passage bypass door is provided for switching between the second air passage and the first air passage to bypass the heater and lead to the upstream side of the air flow of the heater, and when it is detected that the refrigerant has leaked into the air conditioning casing, And the second air passage side and the first air passage side are opened and the refrigerant leaking into the air conditioning casing is discharged from the outlet to the outside of the passenger compartment.

On the other hand, in other Patent Document 2 shown below, a connection in which a heat exchanger in an indoor unit and a pipe through which a refrigerant flows is mechanically connected between a partition wall between the indoor and the outdoor and a heat exchanger. A technology is described that provides a cover member that surrounds the pipe and the pipe, and surrounds the vicinity of the connecting portion including the pipe with the cover member, thereby preventing outflow into the room due to refrigerant leakage with an inexpensive configuration.
JP 2004-189129 A JP2002-174448

  In such a conventional vehicle air conditioner, in order to discharge the leaked refrigerant out of the passenger compartment, a complicated communication path, a plurality of opening / closing doors, and a cover member are provided. This resulted in an increase in the time required for assembly work and an increase in cost.

  Therefore, the present invention has been made in view of the above, and an object thereof is to provide a vehicle air conditioner that prevents the refrigerant leaked from the air conditioner from flowing into the vehicle interior.

  In order to achieve the above object, a means for solving the problems of the present invention is a vehicle air conditioner for sending air, which has been heat exchanged with a refrigerant by a heat exchange means disposed in an air conditioning casing, into a vehicle interior. A refrigerant leakage detecting means for detecting a leakage of the refrigerant from the heat exchanging means, a refrigerant isolating means for isolating at least the refrigerant leaked into the air conditioning casing, and a refrigerant leaking from the heat exchanging means. And a suction means for sucking the refrigerant separated by the separation means into a negative pressure region where a negative pressure is generated by an intake action of the engine.

  According to the present invention, the leaked refrigerant is isolated and sucked out of the air conditioning casing, whereby the leaked refrigerant can be prevented from entering the vehicle interior.

  DESCRIPTION OF THE PREFERRED EMBODIMENTS The best embodiment for carrying out the present invention will be described below with reference to the drawings.

  FIG. 1 is a diagram illustrating a configuration of a vehicle air conditioner according to a first embodiment of the present invention. In the apparatus of Embodiment 1 shown in FIG. 1, the air conditioning casing 1 is a duct means that constitutes a passage for sending air into the passenger compartment, and an intake door 2 is provided on the most upstream side of the airflow of the air conditioning casing 1. It has been. The intake door 2 is means for switching between taking air from the passenger compartment into the air conditioning casing 1 (internal air circulation) or taking air from outside the passenger compartment into the air conditioning casing 1 (introducing outside air). A blower 3 for blowing the air in the air conditioning casing 1 downstream is provided on the downstream side of the air flow of the intake door 2. An evaporator 4 that cools the air by exchanging heat between the air and the refrigerant is provided on the downstream side of the air flow of the blower 3. The evaporator 4 is a heat exchanger having a cooling function by evaporating a refrigerant of, for example, carbon dioxide that has been decompressed. As the refrigerant, for example, propane or ammonia can be used in addition to carbon dioxide.

  A heater 5 of a heat exchanger that heats air by exchanging heat between air and a heat medium is provided on the downstream side of the air flow of the evaporator 4. A heater door 6 for switching whether to supply air to the heater 5 is provided on the upstream side of the air flow of the heater 5.

  At the most downstream side of the air flow of the air conditioning casing 1, there is a defroster outlet 7 for sending air from the air conditioning casing 1 to the window glass of the vehicle, and a face outlet for sending air from the air conditioning casing 1 mainly to the upper body of the passenger in the passenger compartment. 8 and a foot outlet 9 for sending air mainly to the lower body of the occupant. The defroster outlet 7 is provided with a mode door 10 for controlling communication between the air-conditioning casing 1 and the passenger compartment. Similarly, the face outlet 8 is provided with a mode door 11 for controlling communication between the air-conditioning casing 1 and the passenger compartment. The foot outlet 9 is provided with a mode door 12 for controlling the communication between the air conditioning casing 1 and the passenger compartment. By closing these mode doors 10, 11, 12, the air conditioning casing 1 and the passenger compartment are not in communication.

  On the upstream side of the air flow of the evaporator 4, a suction path 13 is provided as a suction path when the refrigerant leaked from the evaporator 4 is sucked out of the air conditioning casing 1. The suction path 13 is provided with a communication control valve 14 that controls communication of the suction path 13. The air flow downstream side of the suction passage 13 is connected to a negative pressure region on the intake side that is negative with respect to atmospheric pressure when the cylinder 16 of the engine performs an intake operation via the intake port 17. A vacuum booster 15 that assists the braking force using this negative pressure is connected to the negative pressure region.

  Further, the vehicle air conditioner of the first embodiment includes a refrigerant leakage detection means (not shown) for detecting refrigerant leakage and an air conditioning control unit 18.

  The refrigerant leakage detection means is constituted by a concentration sensor that detects the concentration of carbon dioxide or oxygen in the refrigerant, and this concentration sensor is provided in the air conditioning casing 1 or in the passenger compartment. Alternatively, the refrigerant leakage detection means is constituted by vehicle collision detection means for detecting a collision of a vehicle on which the vehicle air conditioner is mounted. The vehicle collision detection means includes, for example, a vehicle control unit 19 that has a function of controlling the overall traveling of the vehicle and controlling the operation of an air bag mounted when the vehicle collides. In this case, an airbag activation signal for activating the airbag is output from the vehicle control unit 19 to the air conditioning control unit 18, and it is estimated that the refrigerant may leak due to a collision of the vehicle to the extent that the airbag is activated. It is assumed that refrigerant leakage is detected by the refrigerant leakage detection means.

  The air conditioning control unit 18 functions as a control center that controls the operation of the vehicle air conditioner, and includes resources such as a CPU, a storage device, and an input / output device necessary for a computer that controls various operation processes based on a program. For example, it is realized by a microcomputer or the like. The air conditioning control unit 18 reads signals collected by various sensors (not shown) including the refrigerant concentration detection means, and takes in the intake door based on the read various detection signals and control logic (program) stored in advance inside. 2, an operation control signal is sent to the blower 3, the evaporator 4, the heater 5, the heater door 6, the mode doors 10, 11, 12 and the communication control valve 14, and the operation of the apparatus including the operation when the refrigerant described below is leaked. Supervises and controls all operations necessary for operation.

  Next, the operation when the refrigerant leaks from the evaporator 4 will be described with reference to the flowchart of FIG.

  First, it is determined whether or not the refrigerant has leaked from the evaporator 4 by the refrigerant leakage detection means. When the refrigerant leakage means is composed of the above-described concentration sensor that detects the concentration of the refrigerant, it is determined that the refrigerant is leaking if the concentration detected by the concentration sensor is equal to or higher than a preset concentration. . On the other hand, in the case where the refrigerant leakage means is constituted by the vehicle collision detection means described above, when the airbag operation signal is given from the vehicle control unit 19 to the air conditioning control unit 18, the evaporator 4 is damaged by the collision of the vehicle. It is considered that the refrigerant has leaked because there is a possibility that the refrigerant will leak due to failure (step S21).

  When leakage of the refrigerant is detected, the blower 3 is stopped to stop air blowing (step S22). Subsequently, all the mode doors 10, 11, and 12 are closed (step S23), and then the intake door 2 is switched to the outside air introduction side (step S24). Thereby, the refrigerant | coolant which leaked in the air conditioning casing 1 from the evaporator 4 is isolated from the passenger | crew in a vehicle interior.

  Next, the communication control valve 14 of the suction path 13 is opened from the closed state, and the air conditioning casing 1 and the intake side of the engine are connected via the suction path 13 to be in a communication state (step S25). As a result, the refrigerant that has leaked into the air conditioning casing 1 is forcibly sucked into the intake side of the engine that becomes a negative pressure region due to the intake operation of the engine.

  Thereby, compared with the case where the leaked refrigerant | coolant is discharge | released to atmospheric pressure, the refrigerant | coolant which leaked reliably and rapidly can be discharged | emitted out of a vehicle interior. In addition, even in the situation where there is an obstacle that prevents air flow due to, for example, a collision inside and outside the intake door 2 and is not released to the outside air via the intake door 2, the intake air of the engine is isolated after isolating the leaked refrigerant. By sucking to the side, the leaked refrigerant can be reliably discharged out of the passenger compartment. Further, when a large amount of refrigerant leaks, if the blower 3 is stopped and the mode doors 10, 11, 12 are only closed, the refrigerant leaking from the gaps between the mode doors 10, 11, 12 and the like enters the vehicle interior. Although it may flow in, it is possible to reliably prevent intrusion into the vehicle interior and reflow of the refrigerant released from the air conditioning casing 1 to the outside of the vehicle interior into the air conditioning casing 1 by sucking the leaked refrigerant. it can.

  By adopting the airbag operation signal of the vehicle collision detection means as the refrigerant leak detection means, it is possible to detect the refrigerant leak and reliably perform the suction operation of the leaked refrigerant, and to detect the refrigerant leak There is no need to provide a new configuration.

  By constructing at least a means for isolating the refrigerant leaked from the intake door 2 and the mode doors 10, 11, 12, which has been conventionally provided in a vehicle air conditioner, into the air conditioning casing 1, a new configuration as an isolating means There is no need to provide a configuration, and an increase in the size of the configuration can be avoided.

  As shown in the flowchart of FIG. 3, after performing the operations in steps S21 to S25 similar to those shown in the flowchart of FIG. 2, the pressure in the vacuum booster 15 is detected by a pressure sensor (not shown). Then, it is determined whether or not the detected pressure is equal to or higher than a predetermined pressure set in advance (step S26), and the pressure in the vacuum booster 15 becomes equal to or higher than the predetermined pressure due to the suction operation of the leaked refrigerant. In that case, the communication control valve 14 of the suction path 13 may be closed (step S27) to stop the suction operation. By adopting such an operation, it is possible to prevent the brake assist force from being lowered by the vacuum booster 15 connected to the negative pressure region on the intake side of the engine. Therefore, the predetermined pressure is set to a value that does not cause a reduction in assist force.

It is a figure which shows the structure of the vehicle air conditioner which concerns on Example 1 of this invention. It is a flowchart which shows the procedure of the operation | movement which concerns on Example 1 of this invention. It is a flowchart which shows the procedure of the other operation | movement which concerns on Example 1 of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Air conditioning casing 2 ... Intake door 3 ... Blower 4 ... Evaporator 5 ... Heater 6 ... Heater door 7 ... Defroster delivery outlet 8 ... Face delivery outlet 9 ... Foot delivery outlet 10, 11, 12 ... Mode door 13 ... Suction path 14 ... Communication control valve 15 ... Vacuum booster 16 ... Cylinder 17 ... Intake port 18 ... Air conditioning control unit 19 ... Vehicle control unit

Claims (5)

In the vehicle air conditioner that sends out the air heat-exchanged with the refrigerant by the heat exchange means arranged in the air-conditioning casing into the vehicle interior,
Refrigerant leakage detection means for detecting leakage of refrigerant or the possibility of leakage from the heat exchange means;
Refrigerant isolating means for isolating at least the refrigerant leaking into the air conditioning casing;
A vehicle air conditioner comprising: suction means for sucking the refrigerant leaked from the heat exchange means and isolated by the refrigerant isolation means into a negative pressure region in which a negative pressure is generated by an intake action of the engine. 2. The apparatus according to claim 1, further comprising: a stopping unit that stops a blower that blows air in the air conditioning casing when the refrigerant leakage detection unit detects the leakage of the refrigerant or the possibility of the leakage. Vehicle air conditioner. The refrigerant leakage detection means is constituted by a vehicle collision detection means for detecting a vehicle collision, and detects the possibility of refrigerant leakage when a vehicle collision is detected by the vehicle collision detection means. The vehicle air conditioner according to claim 1 or 2. The refrigerant separating means opens and closes an intake door for switching between an outside air side and a vehicle interior side of an air introduction port introduced into the air conditioning casing, and a delivery port for sending the air in the air conditioning casing to the vehicle interior A door is configured, and when the refrigerant leaks, the intake door is switched to the outside air side, and the mode door is closed to shut off the vehicle interior and the air conditioning casing. The vehicle air conditioner according to any one of claims 3 to 4. Pressure detecting means for detecting the pressure in the vacuum booster that assists the braking force using the negative pressure generated by the intake action of the engine;
5. The suction device according to claim 1, wherein the suction device stops suction when the pressure detected by the pressure detection device becomes equal to or higher than a predetermined pressure. 6. Vehicle air conditioner.

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