| Control apparatus for variable capacity compressor and method of calculating torque of variable capacity compressor -> Monitor Keywords |
|
|
  Control apparatus for variable capacity compressor and method of calculating torque of variable capacity compressorRelated Patent Categories: Pumps, Condition Responsive Control Of Drive Transmission Or Pump Displacement, Adjustable Cam Or Linkage, Axial Cam, With Sump Pressure ActuationThe Patent Description & Claims data below is from USPTO Patent Application 20060275145. Brief Patent Description - Full Patent Description - Patent Application Claims
CROSS REFERENCE TO RELATED APPLICATIONS AND INCORPORATION BY REFERENCE [0001] This application is based on and claims the benefit of priority from the prior Japanese Patent Application No. 2005-153188 filed on May 25, 2005; the entire contents thereof are incorporated herein by reference. BACKGROUND OF THE INVENTION [0002] 1. Field of the Invention [0003] The present invention relates to a method of and an apparatus for calculating and controlling torque of a variable capacity compressor arranged in a refrigeration cycle. [0004] 2. Description of Related Art [0005] A variable capacity compressor is utilized in a refrigeration cycle of, for example, an air conditioner of a vehicle. In the vehicle, the compressor is connected to a vehicle engine by an endless belt. The belt connects a main pulley fixed to a drive shaft of the engine to a follower pulley fixed to a drive shaft of the compressor. The engine serves as a driving source for driving the compressor. If the compressor varies its coolant discharge capacity, the load on the engine varies, which may cause an engine stall during an idling operating. To prevent this, an engine controller must control an intake air quantity (fuel mixture supply quantity) in response to the load (torque) of the compressor. To achieve this, the engine controller must know the torque of the compressor. For this, there have been proposed various compressor torque calculating apparatuses, such as those disclosed in Japanese Unexamined Patent Application Publications No. Hei-5-99156, No. 2004-211663, and No. 2003-278660. [0006] Among these torque calculation apparatuses, Japanese Unexamined Patent Application Publications No. Hei-5-99156 calculates a coolant flow rate according to information (a high pressure in a refrigeration cycle, a coolant temperature in a condenser, an ambient temperature, and the like), and according to the calculated coolant flow rate, estimates torque of the compressor. The torque estimated by this related art is a steady-state torque, i.e., an operating torque of the compressor during a period in which a refrigeration cycle is steadily passing coolant. SUMMARY OF THE INVENTION [0007] In a short period at the start of operation of the variable capacity compressor, for example, in a period of about four seconds after the start of the compressor, the flow of coolant is unstable, and therefore, it is impossible for the related art to estimate torque based on a coolant flow rate. When the compressor is stopped, coolant in the compressor changes its pressure to an equilibrium state. During the pressure changing period, a piston in the compressor is moving, and therefore, it is difficult to estimate the position of the piston, and therefore, it is impossible to estimate a start torque of the compressor when the compressor is restarted soon after being stopped. Due to this, some related art compressor controllers prohibit activation of the compressor for ten seconds after the compressor is stopped. This is inconvenient in terms of free control of the compressor. The compressor must be turned on and off whenever required. [0008] the present invention provides a method of and an apparatus for calculating torque of a variable capacity compressor, even when the compressor is restarted just after being stopped. [0009] A first aspect of the present invention provides a method of calculating torque of a variable capacity compressor. The compressor includes a suction chamber, a cylinder bore, a discharge chamber, a piston to draw coolant from the suction chamber into the cylinder bore, compress the drawn coolant, and discharge the compressed coolant into the discharge chamber, a clutch configured to transmit driving force from a driving source to drive the piston and configured to disconnect the driving force of the driving source so that the piston is not driven, and a pressure adjuster to adjust a back pressure introduced from the discharge chamber to the back of the piston and thereby adjust a piston stroke. The method includes counting an OFF time when the clutch is tuned off from an ON state until the clutch is next turned on, determining whether or not the OFF time is less than a predetermined time, and calculating a start torque of the compressor depending on the determination. [0010] According to a second aspect of the present invention provides a method of calculating torque of a variable capacity compressor. The compressor includes a suction chamber, a cylinder bore, a discharge chamber, a piston to draw coolant from the suction chamber into the cylinder bore, compress the drawn coolant, and discharge the compressed coolant into the discharge chamber, a clutch configured to transmit driving force from a driving source to drive the piston and configured to disconnect the driving force of the driving source so that the piston is not driven, and a pressure adjuster to adjust a back pressure introduced from the discharge chamber to the back of the piston and thereby adjust a piston stroke. The method includes: providing the pressure adjuster with an external control signal for at least a predetermined time after the clutch is turned off, the external control signal being identical to a maximum capacity signal to establish a full piston stroke; and calculating a start torque of the compressor when the clutch is turned on. [0011] A third aspect of the present invention provides a method of calculating torque of a variable capacity compressor. The compressor includes a suction chamber, a cylinder bore, a discharge chamber, a piston to draw coolant from the suction chamber into the cylinder bore, compress the drawn coolant, and discharge the compressed coolant into the discharge chamber, a clutch configured to transmit driving force from a driving source to drive the piston and configured to turn off so as to disconnect the driving force of the driving source so as to stop the piston, and a pressure adjuster to adjust a back pressure introduced from the discharge chamber to the back of the piston and thereby adjust a piston stroke. The method includes providing the pressure adjuster with an external control signal after the clutch is turned off from an ON state, the external control signal being identical to a maximum capacity signal to establish a full piston stroke, counting an OFF time when the clutch is tuned off from an ON state until the clutch is next turned on, determining whether or not the OFF time is less than a predetermined time, and calculating a start torque of the compressor depending on the determination. BRIEF DESCRIPTION OF THE DRAWINGS [0012] FIG. 1 is a view generally showing a vehicle air conditioner according to an embodiment of the present invention; [0013] FIG. 2 is a sectional view showing a variable capacity compressor of the air conditioner of FIG. 1; [0014] FIG. 3 is a view explaining a capacity changing mechanism of the compressor of FIG. 2; [0015] FIG. 4 is a block diagram showing a compressor controller of the air conditioner of FIG. 1; [0016] FIG. 5 is a view showing a refrigeration cycle in the air conditioner of FIG. 1 and a Mollier chart of the refrigeration cycle; [0017] FIG. 6 is a view showing characteristic curves of compressor suction pressure and compressor discharge pressure with different duty factors in the air conditioner of FIG. 1; [0018] FIG. 7 is a view showing characteristic curves of compressor discharge pressure and torque with a constant load on the refrigeration cycle (evaporator) and different duty factors; [0019] FIG. 8 shows compressor discharge pressure and torque with different loads on the refrigeration cycle (evaporator); [0020] FIG. 9 is a view showing a characteristic curve of torque and compressor discharge pressure with a constant duty factor of 60%; Continue reading... Full patent description for Control apparatus for variable capacity compressor and method of calculating torque of variable capacity compressor Brief Patent Description - Full Patent Description - Patent Application Claims Click on the above for other options relating to this Control apparatus for variable capacity compressor and method of calculating torque of variable capacity compressor patent application. ###  How KEYWORD MONITOR works... a FREE service from FreshPatents1. Sign up (takes 30 seconds). 2. Fill in the keywords to be monitored. 3. Each week you receive an email with patent applications related to your keywords. Start now! - Receive info on patent apps like Control apparatus for variable capacity compressor and method of calculating torque of variable capacity compressor or other areas of interest. ### Previous Patent Application: Jet-venturi back flow prevention structure for a fuel delivery module Next Patent Application: Cleaning apparatus Industry Class: Pumps ### FreshPatents.com Support Thank you for viewing the Control apparatus for variable capacity compressor and method of calculating torque of variable capacity compressor patent info. IP-related news and info Results in 0.35377 seconds Other interesting Feshpatents.com categories: Tyco , Unilever , Warner-lambert , 3m |
||
