Method and apparatus for checking engine performance

• US 4,129,034 A
• Filed: 04/19/1971
• Issued: 12/12/1978
• Est. Priority Date: 04/19/1971
• Status: Expired due to Term

• Current Assignee: Caterpillar Incorporated
• Original Assignee: Caterpillar Americas Company (Caterpillar Incorporated)
• Inventors: Grob, Russel W., Gardner, William J., Franzen, Larry H., Niles, Albert B.
• Primary Examiner(s): Myracle, Jerry W.
• Application Number:
  US05/135,300
• Time in Patent Office: 2,794 Days
• Field of Search: 73/117, 73/113, 73/114, 73/116, 73/707, 73/119 A, 73/117.3, 235/150.51, 235/150.52, 235/151.34, 235/61 J
• US Class Current: 73/114.14
• CPC Class Codes: G01F 9/001 with electric, electro-mechanic or electronic means G01F9/008 and G01F9/02 take precedence
• CPC Class Codes: G01M 15/042 by monitoring a single specific parameter not covered by groups G01M15/06 - G01M15/12
• CPC Class Codes: G01M 15/044 by monitoring power, e.g. by operating the engine with one of the ignitions interrupted; by using acceleration tests

Abstract

Brake horsepower of an internal combustion engine is determined rapidly and without necessarily removing the engine from a vehicle or other work installation and without requiring a complex test installation such as a dynamometer. It has been found that the power output of an engine at a specific engine speed and constant load, is a function of the rate of fuel consumption by the engine provided that certain readily detectable engine malfunctions are absent. A compact instrument, preferably using digital circuits to provide a horsepower readout, is coupled to the engine through a digitizing flow meter disposed in the engine fuel line and through a digitizing tachometer coupled to a rotating element of the engine, the instrument also having means connected to the engine to assure that readings are taken only under substantially constant load conditions.

Claims

1. In a method of determining the power output of an internal combustion engine which is of a type having a known Specific Fuel Consumption rating at a predetermined speed, the steps comprising measuring the rate of fuel consumption at said engine while operating said engine substantially at said predetermined speed, maintaining said speed of said engine and the load thereon substantially constant while measuring said fuel consumption rate thereof to assure validity of said power output determination, and multiplying said measured fuel consumption rate by said known Specific Fuel Consumption rating to determine power output of said engine, wherein said fuel consumption rate measurement is made with timing means in conjunction with a volume measuring flow meter of the form having rotatable fluid metering means, and including the further steps of determining fuel consumption rate by determining the time required for passage of a predetermined amount of fuel through said meter wherein said predetermined amount of fuel is equal to the amount of fuel which said meter transmits in an integral number of revolutions of said rotatable means, and damping fluid pressure pulsations in the fuel flow passage between said engine and said meter.

2. Apparatus for determining the power output of an engine wherein said engine has a known specific fuel consumption value at said particular speed which specific fuel consumption value is a ratio of quantity of fuel consumed per unit power output in a unit time, and wherein power output at a particular speed has a predeterminable mathematical relationship to said specific fuel consumption value and the rate of fuel consumption at said speed, comprising:

means for measuring the rate of fuel consumption of said engine while operating substantially at said speed and for producing an output signal indicative of said rate of fuel consumption, said means for measuring the rate of fuel consumption of said engine including a rotary fluid flow meter coupled to a fuel supply conduit of said engine,

computation means coupled to said fuel consumption rate measuring means and receiving said output signal therefrom and having means for entering said specific fuel consumption value for computing said power output of said engine in accordance with said mathematical relationship, and

accumulator means communicated with said fuel supply conduit for dampening pressure pulsations in the fuel flow therethrough.