Diesel engine starting controller and method

• US 6,164,258 A
• Filed: 06/18/1999
• Issued: 12/26/2000
• Est. Priority Date: 02/23/1998
• Status: Expired due to Fees

• Current Assignee: United States Of America As Represented By The Secretary Of The Army (Government of the United States of America)
• Original Assignee: The United States Of America As Represented By The Secretary Of The Army
• Inventors: Petrovich, Paul A., Schmitz, John J., Stormer, A. David, Rodgers, Jack G.
• Primary Examiner(s): Argenbright, Tony M.
• Assistant Examiner(s): GIMIE, MAHMOUD
• Application Number:
  US09/336,102
• Time in Patent Office: 557 Days
• Field of Search: 123/179.3, 123/179.6, 123/179.21, 123/145 A, 701/102, 219/501, 219/506, 340/640
• US Class Current: 123/179.6
• CPC Class Codes: F02P 19/022 using intermittent current supply

Abstract

A starting controller for a diesel engine. The controller has a microprocor that will provide a current to the glow plugs until they are heated to the desired operating temperature and will then distribute sequential pulses to the individual plugs until the engine reaches the desired operating temperature. The system can have a latching circuit that will prevent the preglow cycle from being reinitiated until the glow plugs have been allowed to cool to a level where reinitiation will not represent a substantial degrading effect on the glow plugs.

Claims

1. A method of starting a diesel cycle engine having a plurality of glow plugs comprising the steps of:

measuring the voltage to be applied to the glow plugs;

calculating a pre-glow time necessary to apply a predetermined number of Watts to the glow plugs to raise the glow plug to an operating temperature;

applying current to the glow plugs for the calculated pre-glow time while simultaneously locking out the starter circuit to prevent premature starting attempts;

initiating engine starter and fuel supply systems after the required pre-glow time has been reached, to begin engine operation;

calculating the time required to provide a predetermined after glow pulse of predetermined wattage to the glow plugs after the pre-glow time to maintain the glow plugs at an optimal operating temperature;

applying current to individual glow plugs in sequence for the calculated time for a predetermined after glow time to help the engine start and reduce the pollutants generated during the initial few minutes of run time while maintaining a nearly constant current flow;

activating a latching circuit upon cessation of the after glow time which prevents reinitiating of the pre-glow cycle for a predetermined period but allows the controller to energize the plugs in the after glow mode should the starter be activated while the protection timer is active.

2. A control system for use in starting a diesel engine having an plurality of glow pugs there being at least one glow plug per cylinder with a source of direct current power source to provide starting energy, including:

a starting switch for activating the control system and provide electrical flow to the engine components;

a voltage sensor which measures the voltage of the direct current power source;

a microprocessor electrically connected to the starting switch and the voltage sensor, the microprocessor adapted to execute a starting protocol in response to the position of the starting switch, the microprocessor taking the measured voltage and a preselected glow plug resistance to calculate a preglow time necessary to raise the temperature of the glow plug to the desired operating temperature, the microprocessor providing an operator signal that the starting switch should be moved to the second, cranking position, after the calculated time has elapsed and a sufficient amount of power has been furnished to the glow plugs, the microprocessor will then provide sequential essentially square wave after glow pulses of energy to individual glow plugs, the after glow pulses of energy being calculated based on the measured voltage from the voltage sensor to maintain the glow plugs at the desired operating temperature for a predetermined time, the after glow pulses being delivered so as to maintain the after glow current at a relatively constant level; and

a starter circuit activated by the microprocessor to furnish current to the starter motor and crank the engine until the combustion cycle begins to function unaided.

3. The control system of claim 2 having a latching circuit associated with the microprocessor, the latching circuit being adapted to maintain a current flow to the microprocessor for a predetermined period of time after the starting circuit has been deactivated so as to prevent the reinitiation of preglow for a period of time sufficient to allow the glow plugs to cool from the preglow cycle.