Method for controlling swash plate compressor and swash plate compressor

Abstract

A method for controlling a swash plate compressor and a swash plate compressor capable of preventing an overload by reducing an inclination angle of the swash plate if the torque calculated using compressor information is overloaded. Disclosed is a method for controlling a swash plate compressor including: a measuring step for measuring a compressor operation information of a swash plate compressor; a torque calculating step for calculating a calculated torque value of the swash plate compressor based on the compressor operation information; an overload determining step for determining whether an overload occurred or not by comparing the calculated torque value calculated in the torque calculating step with a torque set value; and an overload preventing step for preventing an overload by reducing an inclination angle of the swash plate of the swash plate compressor if the overload determining step determines that an overload occurred.

1 . A method for controlling a swash plate compressor, comprising:
 a measuring step for measuring compressor operation information of a swash plate compressor;   a torque calculating step for calculating a calculated torque value of the swash plate compressor based on the compressor operation information measured in the measuring step;   an overload determining step for determining whether an overload occurred or not by comparing the calculated torque value calculated in the torque calculating step with a torque set value; and   an overload preventing step for preventing an overload by reducing an inclination angle of the swash plate of the swash plate compressor if the overload determining step determines that an overload occurred.   
     
     
         2 . The method for controlling the swash plate compressor of  claim 1 , wherein the measuring step measures the compressor operation information including a stroke and a revolutions per minute (RPM). 
     
     
         3 . The method for controlling the swash plate compressor of  claim 2 , wherein the measuring step measures the stroke through a stroke sensor equipped in the swash plate compressor. 
     
     
         4 . The method for controlling the swash plate compressor of  claim 2 , wherein the measuring step measures the compressor operation information that further comprises a discharge pressure. 
     
     
         5 . The method for controlling the swash plate compressor of  claim 4 , wherein the measuring step measures the compressor operation information that further comprises a suction pressure. 
     
     
         6 . The method for controlling the swash plate compressor of  claim 1 , wherein the measuring step comprises:
 a cycle measuring step for measuring a reciprocating cycle of a piston of the swash plate compressor;   a stroke calculating step for calculating a stroke of the swash plate compressor based on the reciprocating cycle of the piston measured in the cycle measuring step; and   an RPM calculating step for calculating an RPM of the swash plate compressor based on the reciprocating cycle of the piston measured in the cycle measuring step.   
     
     
         7 . The method for controlling the swash plate compressor of  claim 1 , wherein the overload determining step determines that an overload occurred if the calculated torque value exceeds the torque set value. 
     
     
         8 . The method for controlling the swash plate compressor of  claim 1 , wherein the overload determining step determines that a load is normal if the calculated torque value is equal to or less than the torque set value, and wherein the method further comprises a refrigerant discharge amount adjusting step for adjusting the inclination angle of the swash plate based on a temperature of air flowed through an evaporator of an air-conditioner if the overload determining step determines that a load is normal. 
     
     
         9 . The method for controlling the swash plate compressor of  claim 8 , wherein the refrigerant discharge amount adjusting step comprises:
 an air temperature measuring step for measuring a temperature of air flowed through the evaporator;   an air temperature comparing step for comparing the air temperature measured in the air temperature measuring step with an air temperature set value; and   an inclination angle adjusting step for adjusting the inclination angle of the swash plate based on the comparison result of the air temperature comparing step.   
     
     
         10 . The method for controlling the swash plate compressor of  claim 9 , wherein the inclination angle adjusting step comprises:
 an inclination angle increasing step for increasing the inclination angle of the swash plate if the measured air temperature value exceeds the air temperature set value in the air temperature comparing step; and   an inclination angle decreasing step for decreasing the inclination angle of the swash plate if the measured air temperature value is below the air temperature set value in the air temperature comparing step.   
     
     
         11 . The method for controlling the swash plate compressor of  claim 1 , further comprising:
 a transmitting step for transmitting the calculated torque value calculated in the torque calculating step to an engine control unit.   
     
     
         12 . A method for controlling a swash plate compressor, comprising:
 an air temperature measuring step for measuring a temperature of air flowed through an evaporator of an air-conditioner;   a target stroke calculating step for calculating a target stroke based on a gap between the measured air temperature and an air temperature set value;   a target ECV opening amount calculating step for calculating a target external control valve (ECV) opening amount based on the target stroke calculated in the target stroke calculating step; and   an ECV opening amount adjusting step for adjusting an actual ECV opening amount to be a target ECV opening amount.   
     
     
         13 . The method for controlling the swash plate compressor of  claim 12 , further comprising:
 a stroke comparing step for comparing a measured stroke with a target stroke after the ECV opening amount adjusting step, wherein the ECV opening amount calculating step and the ECV opening amount adjusting step are retried if the measured stroke and the target stroke do not match in the stroke comparing step.   
     
     
         14 . A method for controlling a swash plate compressor, comprising:
 a measuring step for measuring a revolutions per minute (RPM) of a swash plate compressor;   a comparing step for comparing the RPM measured in the measuring step with a calculated RPM; and   a protecting step for stopping a clutch and generating an error alarm or for reducing an inclination angle of a swash plate to a minimum and generating an error alarm if the measured RPM and the calculated RPM do not match in the comparing step, and wherein the generation of an error alarm is characterized in lighting a warning lamp, or generating a diagnostic code.   
     
     
         15 . (canceled) 
     
     
         16 . A swash plate compressor, comprising:
 a housing having a crankcase, a cylinder bore, a suction chamber and a discharge chamber;   a rotating shaft rotatably mounted on the housing;   a swash plate rotating inside the crankcase and interworking with the rotating shaft;   a piston interworking with the swash plate, reciprocating inside the cylinder bore and forming a compression chamber together with the cylinder bore;   a measurement device measuring a reciprocating cycle of the piston; and   a control device performing at least one among controlling a refrigerant discharge amount, controlling a torque, preventing belt slip and preventing compressor sticking according to the method of  claim 1  based on the measured value of the measurement device, wherein the measurement device is a stroke sensor measuring a change in a magnetic field occurred by a groove formed in the piston when the piston reciprocates.   
     
     
         17 . (canceled) 
     
     
         18 . The swash plate compressor of  claim 16 , further comprising:
 a first pressure sensor disposed in the discharge chamber and measuring a discharge pressure.   
     
     
         19 . The swash plate compressor of  claim 16 , further comprising:
 a second pressure sensor disposed in the suction chamber and measuring a suction pressure.   
     
     
         20 . A method for controlling a swash plate compressor, comprising:
 a measuring step for measuring a compressor operation information of a swash plate compressor;   a low refrigerant state determining step for determining whether the swash plate compressor is in a low refrigerant state or not; and   an error alarm generating step for generating an error alarm if the swash plate compressor is in the low refrigerant state, wherein the generation of an error alarm is characterized in lighting a warning lamp, or generating a diagnostic code, wherein the measuring step measures the compressor operation information including a stroke, and wherein the low refrigerant state determining step is characterized in determining that the swash plate compressor is in the low refrigerant state if a gap between the current value of the stroke and a predetermined appropriate value of the stroke exceeds a first reference value.   
     
     
         21 . (canceled) 
     
     
         22 . The method for controlling a swash plate compressor of  claim 20 , wherein the measuring step measures the compressor operation information including a stroke and a discharge pressure; and a temperature of air flowed through an evaporator of an air-conditioner, and wherein the low refrigerant state determining step is characterized in:
 calculating a current refrigerant amount of the swash plate compressor by using the stroke, the discharge pressure and the air temperature; and   determining that the swash plate compressor is in the low refrigerant state if a gap between a predetermined normal value of the refrigerant amount and the current refrigerant amount exceeds a second reference value.