Air conditioning system for a motor vehicle

Details Air conditioning system for a motor vehicle Air conditioning system for a motor vehicle

1999-08-20

2001-02-27

Doerrler, William (Department: 3744)

Refrigeration

Automatic control

Refrigeration producer

C062S160000, C062S228100

Reexamination Certificate

active

06192700

ABSTRACT:

TECHNICAL FIELD
The present invention relates to an air conditioning system for the passenger compartment of a motor vehicle, and more particularly to an air conditioning system which can provide both heating and cooling for the passenger compartment.
BACKGROUND OF THE INVENTION
Air conditioning systems for the passenger compartments of motor vehicles are well known. In general, these systems comprise an inside heat exchanger (located within the passenger compartment) and an outside heat exchanger (located outside the passenger compartment). A pair of fluid passages connect the heat exchangers to allow the circulation of fluid through the heat exchangers. An expansion device is positioned in one of the fluid passages. A compressor and accumulator/dryer is positioned in the other fluid passage. When fluid is pumped by the compressor through the outside heat exchanger, the expansion device, the inside heat exchanger and the accumulator/dryer in succession, air passing through the inside heat exchanger is cooled as the air flows into the passenger compartment. When fluid is pumped in the reverse direction through the inside heat exchanger, the expansion device, the outside heat exchanger and the accumulator/dryer in succession, air passing through the inside heat exchanger is heated as the air flows into the passenger compartment. A reversing valve can be positioned in the other fluid passage to provide the required flow direction for the fluid.
In general, a pneumatic arrangement is used to control the displacement of the compressor, the pneumatic arrangement having an essentially fixed control set point. Such an arrangement has restricted control and does not provide for full control of compressor displacement throughout the range of possible operating conditions, especially during heating of the passenger compartment. Also, the use of compressor speed control is unsuitable in motor vehicles because the compressor is driven by the engine of the motor vehicle, and the engine speed is continually varying.
SUMMARY OF THE INVENTION
It is an object of the present invention to overcome the above mentioned problems.
An air conditioning system in accordance with the present invention for a passenger compartment of a motor vehicle comprises a first heat exchanger positionable outside the passenger compartment; a second heat exchanger positionable inside the passenger compartment; a first fluid passage between the first and second heat exchangers; a second fluid passage between the first and second heat exchangers; an expansion device positioned in the first fluid passage; an accumulator/dryer fluidly connected with the second fluid passage; an electronically controlled variable stroke compressor for pumping fluid into the second fluid passage and either in a first direction sequentially through the first heat exchanger, the expansion device, the second heat exchanger and the accumulator/dryer, or in a second direction sequentially through the second heat exchanger, the expansion device, the first heat exchanger and the accumulator/dryer; reverse flow means in the second fluid passage for controlling the direction of the flow of fluid; sensing means providing an output signal dependent on one or more sensed conditions; and control means electrically connected to the sensing means and to the compressor for receiving the output signal from the sensing means and for controlling the stroke of the compressor dependent on the output signal during fluid flow in the second direction.
Because of the use of an electronically controlled variable stroke compressor, the present invention allows more precise control of the pumping capacity of the compressor when the air conditioning system is heating the passenger compartment. This has particular benefits when supplemental heating is required—that is, on initial starting of the engine of the motor vehicle or where an engine provides a low heat output. The present invention provides an air conditioning system which operates dependent on sensed conditions, thereby having the options of providing benefits in terms of fuel consumption, faster engine warm-up, reduced exhaust emissions, and improved passenger comfort.


REFERENCES:
patent: 2498861 (1950-02-01), Newton
patent: 4248053 (1981-02-01), Sisk
patent: 4269261 (1981-05-01), Kountz et al.
patent: 4345442 (1982-08-01), Dorman
patent: 4353220 (1982-10-01), Curwen et al.
patent: 4866944 (1989-09-01), Yamazaki
patent: 4939910 (1990-07-01), Umezu et al.
patent: 4989414 (1991-02-01), Murayama et al.
patent: 5537831 (1996-07-01), Isaji et al.
patent: 5628201 (1997-05-01), Bahel et al.
patent: 5632442 (1997-05-01), Misawa et al.
patent: 5673568 (1997-10-01), Isshiki
patent: 5689963 (1997-11-01), Bahel et al.
patent: 0 509 619 A2 (1992-10-01), None
patent: 2155165 (1985-09-01), None
patent: 2199125 (1988-06-01), None
patent: 2289124 (1995-11-01), None
patent: 2291181 (1996-01-01), None
patent: H5-87047 (1993-04-01), None

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