Vehicle air conditioner with front and rear air conditioning units

• US 20040074246A1
• Filed: 10/15/2003
• Published: 04/22/2004
• Est. Priority Date: 10/21/2002
• Status: Active Grant

• Current Assignee: DENSO Corporation
• Original Assignee: DENSO Corporation
• Inventors: Takano, Yoshiaki, Kurata, Shun
• Granted Patent: US 6,971,246 B2
• Time in Patent Office: Days
• US Class Current: 62/196.4
• CPC Class Codes: B60H 1/00328 of the liquid-air type
• CPC Class Codes: B60H 1/00885 Controlling the flow of heating or cooling liquid, e.g. valves or pumps B60H1/00899 takes precedence; constructions of valves B60H1/00485
• CPC Class Codes: B60H 1/323 characterised by comprising auxiliary or multiple systems, e.g. plurality of evaporators, or by involving auxiliary cooling devices
• CPC Class Codes: B60H 2001/00942 comprising a plurality of heat exchangers, e.g. for multi zone heating or cooling
• CPC Class Codes: F25B 2339/0441 containing a drier or a filter
• CPC Class Codes: F25B 2339/0444 where the flow of refrigerant through the condenser receiver is split into two or more flows, each flow following a different path through the condenser receiver
• CPC Class Codes: F25B 2400/0403 for the condenser
• CPC Class Codes: F25B 2400/23 Separators
• CPC Class Codes: F25B 41/24 Arrangement of shut-off valves for disconnecting a part of the refrigerant cycle, e.g. an outdoor part
• CPC Class Codes: F25B 43/006 Accumulators
• CPC Class Codes: F25B 5/02 arranged in parallel

Abstract

In a vehicle air conditioner having front and rear air conditioning units, a refrigerant cycle includes front and rear evaporators for cooling air in a cooling mode, a hot-gas bypass passage through which hot-gas refrigerant discharged from a compressor flows into the front evaporator while bypassing a condenser in a heating mode, and a fixed throttle between the condenser and the front evaporator for decompressing refrigerant flowing from the condenser in the cooling mode. Further, a refrigerant outlet side of the fixed throttle and a refrigerant outlet side of the hot-gas bypass passage are joined to a refrigerant pipe, and a refrigerant outlet of the refrigerant pipe is connected to a refrigerant inlet of the front evaporator. Therefore, a refrigerant pipe structure of the refrigerant cycle can be made simple.

Claims

1. An air conditioner for a vehicle comprising:

a front air conditioning unit for air-conditioning a front area in a passenger compartment of the vehicle;

a rear air conditioning unit for air-conditioning a rear area in a passenger compartment;

a compressor for compressing refrigerant;

a condenser for condensing gas refrigerant discharged from the compressor in a cooling mode;

a front evaporator disposed in the front air conditioning unit, for cooling air in the cooling mode and for heating air in a heating mode;

a rear evaporator disposed in the rear air conditioning unit for cooling air in the cooling mode;

a hot-gas bypass passage through which the gas refrigerant discharged from the compressor flows into the front evaporator while bypassing the condenser in the heating mode;

a decompression unit, disposed between the condenser and the front evaporator, for decompressing refrigerant flowing from the condenser in the cooling mode; and

a refrigerant pipe to which a refrigerant outlet side of the decompression unit and a refrigerant outlet side of the hot-gas bypass passage are joined,

wherein the refrigerant pipe has a refrigerant outlet that is connected to a refrigerant inlet of the front evaporator.

2. The air conditioner according to claim 1, wherein:

the condenser includes first and second heat-exchanging units which are disposed in this order in a refrigerant flow direction, and a high-pressure gas-liquid separator disposed between the first heat-exchanging unit and the second heat-changing unit for separating refrigerant into gas refrigerant and liquid refrigerant; and

the high-pressure gas-liquid separator is disposed such that an amount of the liquid refrigerant stored in the gas-liquid separator is changed in accordance with a superheating degree of the gas refrigerant discharged from the compressor.

3. The air conditioner according to claim 1, wherein the decompression unit is a fixed throttle.

4. The air conditioner according to claim 1, further comprising:

a low-pressure gas-liquid separator for separating refrigerant into gas refrigerant and liquid refrigerant, wherein;

the low-pressure gas-liquid separator is coupled to a refrigerant outlet of the front evaporator and a refrigerant outlet of the rear evaporator; and

the low-pressure gas-liquid separator has a refrigerant outlet portion through which gas refrigerant is introduced to a suction port of the compressor.

5. The air conditioner according to claim 4, further comprising:

an evaporator outlet pipe having one end connected to the refrigerant outlet of the rear evaporator, and the other end connected to the low-pressure gas-liquid separator; and

a check valve disposed in the evaporator outlet pipe, for preventing a reverse flow from the low-pressure gas-liquid separator toward the rear evaporator, wherein;

the evaporator outlet pipe has a wall portion defining a reduced passage area; and

the check valve has a valve body that contacts the wall portion when a refrigerant flow from the gas-liquid separator toward the rear evaporator is shut.

6. The air conditioner system according to claim 5, further comprising:

an engagement portion provided in the valve body, wherein the engagement portion is engaged with the wall portion to regulate an opening degree of the check valve when the valve body is moved to a valve-opening position.

7. The air conditioner according to claim 4, further comprising:

an evaporator outlet pipe including a first pipe portion connected to the refrigerant outlet of the rear evaporator, and a second pipe portion connected to the low-pressure gas-liquid separator; and

a check valve disposed between the first pipe portion and a second pipe portion to be connected therebetween, for preventing a reverse flow from the low-pressure gas-liquid separator toward the rear evaporator.