Electronic trim for a variable delivery pump in a hydraulic system for an engine

Abstract

Electronically controlled variable delivery pumps produce output based upon a control signal generated by an electronic control module. The electronic control module includes programming that acknowledges that each pump may have performance characteristics that deviate from a hypothetical nominal pump. Actual pump performance characteristics are then programmed into the electronic control module so that pump control signals are customized or electronically trimmed to suit the performance characteristics of that individual pump. The performance characteristics of the individual pump are gained through testing. The electronic pump trimming strategy of the present invention is particularly applicable to hydraulic systems, such as fuel injection systems, used in internal combustion engines.

1 - 20 . (canceled)  
   
   
       21 . A method of preparing a mechanically actuated electronically controlled variable delivery pump for tuning before installation in a fluid system, comprising the steps of: 
 testing at least one pump operating condition at least in part by mechanically powering the pump while supplying a pump controller with a predetermined electronic control signal;    recording at least one pump test result indicative of an output flow rate magnitude from the pump;    determining information for programming an electronic controller of a fluid system to adjust a pump control signal based upon the pump test result.    
   
   
       22 . The method of  claim 21  including a step of attaching coded information based on the pump test result to the pump.  
   
   
       23 . The method of  claim 22  wherein said attaching step includes a step of attaching a bar code to the pump.  
   
   
       24 . The method of  claim 21  wherein said testing step includes a step of determining a threshold control signal at which the pump begins to produce output.  
   
   
       25 . The method of  claim 21  wherein the determining step includes a step of determining a shape of a function curve relating control signal magnitude to pump output rate magnitude.  
   
   
       26 . The method of  claim 25  wherein the determining step includes a step of estimating a linear relationship between a control signal and a pump output rate magnitude that includes an intercept and a slope.  
   
   
       27 . The method of  claim 21  including a step of comparing the pump test result to an expected pump result; and 
 the information includes data that is a function of a difference between the expected pump result and the pump test result.    
   
   
       28 . The method of  claim 21  wherein the information includes first data that is a function of a threshold control signal at which the pump begins to produce output, second data that is a function of a curve slope relating control signal magnitude to pump output rate magnitude, and third data that is a function of a maximum control signal magnitude beyond which the pump produces no additional output.  
   
   
       29 . A method of installing a mechanically actuated electronically controlled variable delivery pump, in a fluid system, comprising the steps of: 
 fluidly connecting an inlet and an outlet of the pump to the fluid system;    reading data that is based on test results of the pump's performance characteristics from a data storage device associated with the pump;    programming an electronic controller to generate pump control signals that are a function of the data; and    establishing a control communication link between a pump controller of the pump and the electronic controller.    
   
   
       30 . The method of  claim 29  wherein the reading step includes a step of scanning coded information from a code attached to the pump.  
   
   
       31 . The method of  claim 30  wherein the scanning step includes a step of scanning a bar code attached to the pump.  
   
   
       32 . The method of  claim 29  wherein the programming step includes adjusting a pump model.  
   
   
       33 . The method of  claim 29  wherein the programming step includes a step of setting a threshold control signal at which the pump begins to produce output.  
   
   
       34 . The method of  claim 29  wherein the programming step includes a step of setting a slope of a linear relationship between control signal magnitude and pump output rate magnitude.  
   
   
       35 . The method of  claim 29  including a step of attaching the pump to an engine.  
   
   
       36 . A variable delivery pump comprising: 
 a housing with an inlet and an outlet;    an electronic controller attached to said housing; and    a data storage device attached to said housing; and    pump performance data stored on said data storage device in a machine readable format, wherein the data is based upon a pump output flow rate magnitude test result.    
   
   
       37 . The pump of  claim 36  wherein said data storage device includes a bar code.  
   
   
       38 . The pump of  claim 36  wherein said pump performance data includes a threshold control signal at which said pump begins to produce output.  
   
   
       39 . The pump of  claim 36  wherein said pump performance data includes a curve slope relating control signal magnitude to pump output rate magnitude.  
   
   
       40 . The pump of  claim 36  wherein said pump performance data includes data that is a function of a maximum control signal magnitude beyond which the pump produces no additional output.