Electrical starting system for diesel engines

• US 6,148,258 A
• Filed: 05/12/1998
• Issued: 11/14/2000
• Est. Priority Date: 10/31/1991
• Status: Expired due to Fees

• Current Assignee: Uusi LLC (Nartron Corporation)
• Original Assignee: Nartron Corporation
• Inventors: Rigling, Timothy J., Shank, David W., Boisvert, Mario, Ballast, Ronald L.
• Primary Examiner(s): LOUIS JACQUES, JACQUES H
• Application Number:
  US09/076,291
• Time in Patent Office: 917 Days
• Field of Search: 701/99, 701/101, 701/102, 701/113, 123/145 A, 123/179 H, 123/179 GH, 123/179.6, 123/179.21, 123/179.25, 123/DIG. 3, 123/179.3, 219/492, 219/497, 219/511, 219/518, 361/265, 361/757, 74/7 E, 74/7 C, 74/6
• US Class Current: 701/99
• CPC Class Codes: F02P 19/022 using intermittent current supply
• CPC Class Codes: F02P 19/025 with means for determining glow plug temperature or glow plug resistance
• CPC Class Codes: F02P 19/027 Safety devices, e.g. for diagnosing the glow plugs or the related circuits

Abstract

An integrated electronic starting control system module for diesel engines which provides unique packaging with integration of a multiplicity of features previously unavailable or available only in separate control modules. Integrated into one modular device are improved glow plug and starting system control, monitoring, protection, and diagnostic features. These features for rendering improved glow plug control and diagnostics include: Microprocessor control, adaptive control algorithms, engine analog temperature sensing for glow plug operational compensation, over temperature shut down protection, system glow plug voltage sensing for glow plug operational compensation, timers for control of glow plug operation and duty cycles, sensing of glow plug current for protective shutdown, control relays and/or solid state switches for control of glow plug current(s), manual override control, load dump voltage spike avoidance circuitry based upon alternator output speed, system monitoring with diagnostics communication capability.

Claims

1. For use with a motor vehicle diesel engine having one or more glowplugs for maintaining temperature control of one or more diesel engine combustion chambers, apparatus comprising:

a) a starter control housing supported by the motor vehicle and including a cable connector for routing energization signals into a housing interior from a vehicle mounted power source for use in energizing the glowplugs;

b) monitor circuitry supported within a housing interior for providing an indicator signal corresponding to a voltage applied to the one or more glowplugs;

c) a programmable controller supported within the housing interior that is coupled to the monitor circuitry and produces a control output for supplying energy to the glowplugs;

d) at least one switching device supported within the housing interior that is coupled to the control output from the programmable controller for energizing the one or more glow plugs in a controlled time sequence prior to, during an/or after engine cranking by selectively coupling the energization signals to the glowplugs; and

e) load protection circuitry supported within the housing interior for temporarily maintaining an alternator to battery power correction after removal or an ignition signal until engine speed has been reduced to a specified value.

2. The apparatus of claim 1 additionally comprising a separate circuit located outside the housing for monitoring a temperature status of the vehicle engine.

3. The apparatus of claim 1 wherein the programmable controller is programmed to differentiate between signals from a second glow plug control circuit and signals from a temperature sensor.

4. The apparaus of claim 3 wherein the second glow plug circuit includes a controller having at least one output for energizing the glow plugs and a glow plug control signal from the second glow plug circuit is sensed by the programmable controller and said control signal is replaced by signals from separate control circuitry coupled to the programmable controller.

5. The apparatus of claim 4 wherein a cable connector from the programmable controller is plug compatible with a cable connector of the second glow plug controller to allow the programmable controller to replace the second glow plug controller.

6. The apparatus of claim 1 wherein the programmable controller includes a memory for storing diagnostic information relating to diesel engine operation during a previous time period of engine operation.

7. The apparatus of claim 1 additionally comprising communications signal carrying conductors that are routed through the housing connector to enable the programmable controller to communicate with signal generating devices attached to the motor vehicle outside the housing.

8. The apparatus of claim 7 wherein the programmable controller communicates with other modules and/or vehicle electronics via multiplex (MUX) and demultiplex (DEMUX) circuitry and/or dedicated wiring and/or optical methods and/or magnetic field and/or electric field and/or electromagnetic field and/or sonic methods.

9. The apparatus of claim 1 wherein the programmable controller comprises a microprocessor and further wherein analog signals routed into the housing representing a voltage signals from the power source are performed by the microprocessor.

10. The apparatus of claim 1 wherein the housing comprises a metal housing that shields electronic components within the housing from extraneous electromagnetic fields.

11. The apparatus of claim 1 wherein the housing encloses circuitry for filtering transients transmitted through the housing connector.

12. The apparatus of claim 1 comprising reverse voltage protection circuitry within the housing.

13. The apparatus of claim 1 additionally comprising over voltage and under voltage detection circuitry mounted within the housing.

14. The apparatus of claim 1 wherein the at least one switching device comprises at least one solid state switch.

15. The apparatus of claim 1 wherein the at least one switching device comprises at least one switching relay.

16. The apparatus of claim 15 additionally comprising an inductor connected in series with the resistor means having a ferromagnetic core and an inverse parallel freewheeling diode such that the characteristic resistance-inductance electrical rise time with rising current is slow relative to the time of electromechanical contact bounce so as to reduce contact wear and to reduce electrical transients.

17. The apparatus of claim 1 additionally comprising a remote temperature sensor positoned outside the housing for monitoring engine temperature.

18. The apparatus of claim 17 wherein the temperature sensor comprising one of the following a thermistor, a positive temperature coefficient resistor (PTC), a negative temperature coefficient resistor (NTC), a resistance temperature device (RTD), a temperature sensing diode, a temperature sensing integrated circuit, a bimetallic temperature sensor, and a temperature sensitive pressure bulb.

19. The apparatus of claim 17 wherein the temperature sensor is a platinum resistance temperature devices integral within at least one glowplug which can be monitored for control of maximum and minimum glow plug temperatures.

20. The apparatus of claim 17 wherein the temperature sensor monitors a temperature of a glowplug and comprises a circuit for monitoring glow plug resistance by applying a voltage and/or current to the glow plug.

21. The apparatus of claim 20 wherein the glow plug temperature measurement means comprises a circuit for monitoring glow plug resistance by applying an alternating and/or direct voltage and/or current to the glow plug during on and/or off glow plug power energization times and calculating glow plug resistance which correlates with glow plug temperature.

22. The apparatus of claim 20 wherein the glow plug temperature measurement means comprises a circuit for monitoring glow plug resistance by measuring energizing glow plug power voltage and current and calculating glow plug resistance which correlates with glow plug temperature.

23. The apparatus of claim 20 wherein the glow plug temperature measurement means comprises an integral resistance temperature device (RTD) integrated within at least one glow plug.

24. The apparatus of claim 20 wherein the glow plug temperature measurement means comprises a glass fiber that transmits thermal radiation spectra from at least one glow plug to an interface sensor that correlates said spectra with thermal radiation corresponding to temperature.

25. The apparatus of claim 20 wherein the glow plug temperature measurement means is based upon adaptive learned empirical characteristics of glow plug resistance versus temperature sensed by a discrete known engine component temperature sensing element versus time.

26. The apparatus of claim 1 wherein the programmable controller includes an operating system to adjust glowplug energization based upon one or more of the following sensed conditions:

Battery voltage, glow plug voltage(s), glow plug current(s), engine temperature(s), ambient air temperature, ambient air density, ambient air humidity, fuel injector operating parameters, intake mass air flow, exhaust gas composition, exhaust gas temperature, alternator output, engine speed, engine torque, engine power, engine compression, engine age, fuel type.

27. The apparatus of claim 1 wherein the programmable controller includes an operating system stored in a memory and wherein the operating system functions can be reprogrammed by adjusting the contents of the memory that are based on temperature sensor characteristics, glowplug resistance versus temperature characteristics, engine age, cylinder compression ratio, mileage, or integrated fuel consumption.

28. The apparatus of claim 1 additionally comprising a current sensor for monitoring current through one or more glow plugs and wherein the programmable controller opens a connection to the glow plugs in the event too high a current is sensed to avoid damage to the glow plugs.

29. The apparatus of claim 1 wherein the programmable controller comprises means based upon various sensed conditions to adjust a preglow energization time and an afterglow energization time to limit excessive temperatures of the glow plugs while applying adequate glow plug energy to facilitate engine starting and warmup.

30. The apparatus of claim 29 wherein the programmable controller adjusts the preglow and afterglow energization times to maintain the glowplug temperature with a specified range above ambient temperature.

31. The apparatus of claim 30 wherein the target temperature for the glow plugs is 850 to 1000 degrees Celsius.

32. The apparatus of claim 29 wherein a wait to start lamp outside the housing is energized during a preglow time period.

33. The apparatus of claim 1 additionally comprising a temperature sensor coupled to the programmable controller and further comprising an output circuit contained within the housing coupled through the housing connector to a light outside the housing and wherein upon application of a power signal to the programmable controller within the housing, the programmable controller outputs an activation signal to illuminate the light during a preglow period unless sensed temperature is above a limit.

34. The apparatus of claim 33 wherein the programmable controller includes diagnostic routines for indicating fault conditions by pulsing the light on and off in a controlled sequence.

35. The apparatus of claim 33 wherein the programmable controller disables glow plug energization above a specified temperature.

36. The apparatus of claim 35 wherein if the programmable controller includes a means for sensing current through the switching device and if at any time current through the switching device exceeds a limit the programmable controller outputs a disabling signal for deactivating the switching device.

37. The apparatus of claim 1 additionally comprising circuitry within the housing for sensing an engine run condition and wherein a preglow period of glow plug energization is adjusted if an engine running condition is sensed within a set time period.

38. The apparatus of claim 37 the preglow period is disabled if the engine is sensed to be running.

39. The apparatus of claim 1 wherein the programmable controller includes an input for sensing if the diesel engine is running within a specified frequency range or an alternator is running or a starter motor is cranking the engine at a specified frequency during a preglow time interval then the preglow is disabled and a second afterglow time interval is enabled.

40. The method of claim 1 wherein the programmable controller includes an input for sensing if the diesel engine is running or an alternator is running within a specified frequency range or the starter motor is cranking the engine and wherein the programmable controller has two afterglow intervals and wherein sensing of a running engine or starter motor cranking causes the programmable controller to enter a second afterglow interval.

41. The apparatus of claim 40 wherein the programmable controller senses if the diesel engine and/or alternator is/are running or the starter motor cranking and if such condition is not sensed at the end of a first afterglow time period, then a glow plug control output is shutdown to save battery energy pending a running signal pending such sensed conditions at which time a second afterglow time commences.

42. The apparatus of claim 41 wherein if the programmable controller determines the engine is running above some speed with glow plugs energized in a second afterglow interval and a run/start switch is changed from a run to an off position, the switching off of the glow plug relay and/or the load dump relay will be delayed until a determination via a connection from the alternator, based upon some set signal frequency and/or amplitude, that its speed has slowed down sufficiently before the glow plug relay and/or the load dump relay are/is deenergized so as to reduce the magnitude of alternator produced load dump voltage spikes when electrical current load sourced from the alternator is switched off.

43. The apparatus of claim 1 comprising two or more relays or solid state switches and including at least one switch per glow plug thus enabling independent switching on and off of glow plugs or groups with staggered switching times for affecting reduction of switching transients and especially reduction of load dump magnitude.

44. The apparatus of claim 1 comprising two or more relays or solid state switches and including at least one switch per glow plug thus enabling independent and possibly individual control based upon inputs and calculated variables.

45. The apparatus of claim 1 wherein the programmable controller includes an input for sensing if the diesel engine and/or alternator is/are running above a specified speed and wherein the programmable controller will not energize glow plugs when power is applied by the vehicle start/run switch to temperature resulting from intermittent electrical connections.

46. The apparatus of claim 1 wherein the programmable controller includes a timer means to measure the time elapsed since the last glow plug energization cycle and wherein the programmable controller prorates an immediate preglow energization time of glow plugs based on said elapsed time.

47. The apparatus of claim 1 comprising at least one solid state switch per glow plug to enable independent switching on and off of glow plugs or groups thereof with controlled switching slew rates for affedting reduction of switching transients.

48. For use with a motor vehicle diesel engine having one or more glowplugs for maintaining temperature control of one or more diesel engine combustion chambers, a method of starting the diesel engine comprising the steps of:

a) monitoring an indicator signal corresponding to a voltage applied to the one or more glowplugs;

b) providing a programmable controller and supporting the programmable controller within a housing interior;

c) producing a controlled output from the programmable controller to produce a controlled energization of the glowplugs prior to, during, and/or after engine cranking;

d) coupling the controlled output from the programmable controller to at least one a switching device supported within the housing interior for energizing the one or more glow plugs in a controlled time sequence prior to during, and/or after engine cranking;

e) sensing an output from a vehicle alternator to sense engine speed; and

f) temporarily maintaining alternator to battery power connection after removal of an ignition signal until engine speed has been reduced to a specific value.

49. The method of claim 48 additionally comprising the step of storing operating parameters of the diesel engine in a programmable controller memory for use in diagnosing engine conditions.

50. The method of claim 48 additionally comprising the step of generating communications signals to other programmable controllers within the motor vehicle.

51. The method of claim 48 additionally comprising the steps of monitoring a temperature of the vehicle engine to control glow plug energiziation.

52. The method of claim 51 wherein the step of monitoring the temperature is performed by receipt of a temperature signal from outside the housing.