Automotive air-conditioning servicing system and method
First Claim
1. A method for servicing air-conditioning systems, comprising:
- measuring the high and low side pressures of an air-conditioning system;
converting said measured pressures to electrical signals corresponding to said measured pressures;
analyzing said electrical signals by comparing said electrical signals to electrical signals provided by a data-storage means corresponding to standard pressure values for proper functioning of said system;
providing an output indicating whether said air-conditioning system is functioning properly;
providing an output if said system is not functioning properly indicating one or more possible causes of malfunction of the system; and
providing an output indicating the procedure to be followed by the operator to effect repair of said system if said system is not functioning properly.
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Accused Products
Abstract
Method and apparatus for servicing air-conditioning systems employing electronic processing means for initially diagnosing the air-conditioning system and, thereafter, if tests or repairs are needed, for guiding the mechanic to correction of its defective operation and for charging the system with refrigerant and oil. The apparatus, according to a preferred embodiment, includes a microprocessor operable in three modes: a "system selection" mode during which the type of system being serviced is identified; a "diagnose" mode during which the microprocessor receives signals indicative of the high and low side pressures of the air-conditioning system and develops a list of possible causes of system malfunction, and a "charging" mode during which the microprocessor automatically charges the system with the desired amount of refrigerant and oil. The apparatus further includes means controlled by the microprocessor for automatically compensating for changes in the viscosity and temperature and, hence, of the flow rate of the oil to ensure the air-conditioning system will always be correctly filled. The invention permits accurate diagnosis and repair to be carried out by relatively inexperienced personnel in a straightforward, efficient manner.
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Citations
28 Claims
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1. A method for servicing air-conditioning systems, comprising:
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measuring the high and low side pressures of an air-conditioning system; converting said measured pressures to electrical signals corresponding to said measured pressures; analyzing said electrical signals by comparing said electrical signals to electrical signals provided by a data-storage means corresponding to standard pressure values for proper functioning of said system; providing an output indicating whether said air-conditioning system is functioning properly; providing an output if said system is not functioning properly indicating one or more possible causes of malfunction of the system; and providing an output indicating the procedure to be followed by the operator to effect repair of said system if said system is not functioning properly. - View Dependent Claims (2, 3, 4, 6, 8, 10)
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5. determining from said measured pressures the flow rate through the orifice during each short interval of time and the total flow through the orifice in each short interval of time;
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subtracting the total flow through the orifice in each short interval of time from the amount of fluid needed to charge the air-conditioning system until a zero quantity is reached and terminating the fluid supply.
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7. Apparatus for servicing air-conditioning systems, comprising:
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means for measuring the high and low side pressure of an air-conditioning system; means for converting said high and low side measured pressures to electrical signals corresponding to said measured pressures; electronic processing means for receiving said electrical signals and for comparing said electrical signals with data representing standard values for the proper functioning of said air-conditioning system; and output means connected to said electronic processing means for providing an output indicating whether said system is functioning properly and if said system is not functioning properly, for indicating possible causes of the malfunction and the procedure to be followed by the operator to effect repair of said system. - View Dependent Claims (9, 11, 13)
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12. Apparatus for servicing automotive air-conditioning systems, said apparatus including means for measuring the high and low side pressures of said air-conditioning system, means for charging said system with refrigerant, and means for charging said system with oil;
- the improvement comprising electronic processing means connected to said pressure-measuring means for analyzing said measured high and low side pressures and for diagnosing the condition of said air-conditioning system as a function of said measured high and low side pressure, and output means coupled to said electronic processing means for outputting said diagnosis, indicating one or more possible causes of the malfunction and the procesure to be followed by the operator to effect repair of said system.
- View Dependent Claims (14, 15, 16)
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17. In apparatus for servicing automotive air-conditioning systems, said apparatus including means for measuring the high and low side pressures of said air-conditioning system, means for charging said system with refrigerant, and means for charging said system with refrigerant and oil;
- and microprocessor means, the improvement wherein said means for charging said system with refrigerant and with oil includes a fixed orifice and means to measure the pressure on each side of the fixed orifice, valve means to operate said refrigerant and oil-charging means, and said microprocessor means includes means for operating said valve means, and means for generating a plurality of short time intervals during operation of the refrigerant and oil-charging means, means for calculating the rate of flow of refrigerant and oil and the total flow of refrigerant and oil through the small orifice in each of the plurality of short time intervals and for subtracting the total flow of refrigerant and oil during each of the short time intervals from an amount of refrigerant and oil predetermined by said microprocessor means to properly charge the air-conditioning system until zero is reached and then terminating operation of said valve means.
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18. A method of recharging an air-conditioning system, comprising:
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determining the amount of oil or refrigerant to charge the air-conditioning system; supplying oil or refrigerant to the air-conditioning system through a fixed orifice; measuring the oil or refrigerant pressure on each side of the fixed orifice during a plurality of intervals of time; determining from said measured pressures the flow rate of oil or refrigerant through the orifice during each short interval of time and the total flow of oil or refrigerant through the orifice in each short interval of time; and subtracting the total flow of oil or refrigerant through the orifice in each short interval of time from the amount of oil or refrigerant, respectively, needed to charge the air-conditioning system until a zero quantity is reached and terminating the oil supply. - View Dependent Claims (20, 21, 22, 23, 24, 25, 26, 27, 28)
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19. An apparatus for servicing one of a plurality of different automotive air-conditioning systems, comprising:
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a cabinet, said cabinet including first and second means for measuring the high and low side pressures, respectively, of said automotive air-conditioning systems; an oil storage means; refrigerant storage means; fluid-delivery means coupled to said refrigerant and said oil storage means for charging said systems with refrigerant and oil from said refrigerant and oil storage means, respectively; means for evacuating said systems; means for connecting said first and second pressure-measuring means, said charging means and said evacuating means to said air-conditioning systems; a microprocessor; means for entering information and said high and low side pressures into said microprocessor, said microprocessor providing means to analyze said information and high and low side pressures, to compare said high and low side pressure values with standard values provided by a data-storage means representing proper functioning of said system and to analyze said information and comparison and determine possible causes of malfunctions of a connected air conditioning system and a procedure to effect its repair; and output means connected to said microprocessor for indicating whether said system is functioning properly and, if not, for indicating possible causes of a system malfunction and the procedure to be followed by the operator to effect repair of said system.
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Specification