Diesel engine glow plug energization control circuit

• US 4,137,885 A
• Filed: 10/11/1977
• Issued: 02/06/1979
• Est. Priority Date: 10/11/1977
• Status: Expired due to Term

• Current Assignee: General Motors Corporation (Motors Liquidation Co. GUC Trust)
• Original Assignee: General Motors Corporation (Motors Liquidation Co. GUC Trust)
• Inventors: Van Ostrom, David L.
• Primary Examiner(s): Lazarus, Ronald H.
• Assistant Examiner(s): Reynolds, David D.
• Application Number:
  US05/841,126
• Time in Patent Office: 483 Days
• Field of Search: 123/179 B, 123/179 BG, 123/179 H
• US Class Current: 123/179.21
• CPC Class Codes: F02B 3/06 with compression ignition compression ignition engines using air or gas for blowing fuel into compressed air in cylinder F02B13/02
• CPC Class Codes: F02P 19/025 with means for determining glow plug temperature or glow plug resistance

Abstract

A glow plug temperature simulator circuit produces an electrical signal having a rate of increase of potential level substantially corresponding to the rate of increase of glow plug temperature and a rate of decrease of potential level substantially corresponding to the rate of decrease of glow plug temperature upon glow plug energization and subsequent deenergization, respectively. An electrical switching arrangement is effective to complete a glow plug energizing circuit across an operating potential source in response to the application of operating potential and, thereafter, is effective to alternately interrupt and complete the glow plug energizing circuit in response to the increase of the electrical signal to a predetermined potential level and in response to the decrease of the electrical signal to another lower predetermined potential level, respectively, to cyclically complete and interrupt the glow plug energizing circuit.

Claims

1. A Diesel engine glow plug energization control circuit for use with Diesel engines having at least one glow plug comprising in combination with a circuit operating potential source;

glow plug temperature simulator means energized by said operating potential source for producing an electrical signal having a rate of increase of potential level substantially corresponding to the rate of increase of glow plug temperature and a rate of decrease of potential level substantially corresponding to the rate of decrease of glow plug temperature upon glow plug energization and subsequent deenergization, respectively, whereby the instantaneous potential level of said electrical signal is indicative of glow plug temperature at that instant; and

means effective to complete a glow plug energizing circuit across said operating potential source in response to the application of operating potential and, thereafter, being effective to alternately interrupt and complete said glow plug energizing circuit in response to the increase of said electrical signal to a predetermined potential level and in response to the decrease of said electrical signal to another lower predetermined potential level, respectively, whereby said glow plug energizing circuit is cyclically completed and interrupted.

2. A Diesel engine glow plug energization control circuit for use with Diesel engines having at least one glow plug comprising in combination with a circuit operating potential source;

glow plug temperature simulator means energized by said operating potential source for producing an electrical signal having a rate of increase of potential level substantially corresponding to the rate of increase of glow plug temperature and a rate of decrease of potential level substantially corresponding to the rate of decrease of glow plug temperature upon glow plug energization and subsequent deenergization, respectively, whereby the instantaneous potential level of said electrical signal is indicative of glow plug temperature at that instant;

means effective to complete a glow plug energizing circuit across said operating potential source in response to the application of operating potential and, thereafter, being effective to alternately interrupt and complete said glow plug energizing circuit in response to the increase of said electrical signal to a predetermined potential level and in response to the decrease of said electrical signal to another lower predetermined potential level, respectively, whereby said glow plug energizing circuit is cyclically completed and interrupted; and

means for preventing said electrical signal from decreasing in potential level below a predetermined potential level indicative of glow plug temperature as a result of engine heat of combustion.

3. A Diesel engine glow plug energization control circuit for use with Diesel engines having at least one glow plug comprising in combination with a circuit operating potential source;

means for producing a first electrical signal of a direct current potential level that is a function of the square of the output potential level of said operating potential source;

means responsive to said first electrical signal for producing a second electrical signal having a rate of increase of potential level substantially corresponding to the rate of increase of glow plug temperature and a rate of decrease of potential level substantially corresponding to the rate of decrease of glow plug temperature upon glow plug energization and subsequent deenergization, respectively, whereby the instantaneous potential level of said second electrical signal is indicative of glow plug temperature at that instant; and

means effective to complete a glow plug energizing circuit across said operating potential source in response to the application of operating potential and, thereafter, being effective to alternately interrupt and complete said glow plug energizing circuit in response to the increase of said second electrical signal to a predetermined potential level and in response to the decrease of said second electrical signal to another lower predetermined potential level, respectively, whereby said glow plug energizing circuit is cyclically completed and interrupted.

4. A Diesel engine glow plug energization control circuit for use with Diesel engines having at least one glow plug comprising in combination with a circuit operating potential source;

means for producing a first electrical signal of a direct current potential level that is a function of the square of the output potential level of said operating potential source;

means responsive to said first electrical signal for producing a second electrical signal having a rate of increase of potential level substantially corresponding to the rate of increase of glow plug temperature and a rate of decrease of potential level substantially corresponding to the rate of decrease of glow plug temperature upon glow plug energization and subsequent deenergization, respectively, whereby the instantaneous potential level of said second electrical signal is indicative of glow plug temperature at that instant;

means effective to complete a glow plug energizing circuit across said operating potential source in response to the application of operating potential and, thereafter, being effective to alternately interrupt and complete said glow plug energizing circuit in response to the increase of said second electrical signal to a predetermined potential level and in response to the decrease of said second electrical signal to another lower predetermined potential level, respectively, whereby said glow plug energizing circuit is cyclically completed and interrupted; and

means for preventing said second electrical signal from decreasing in potential level below a predetermined potential level indicative of glow plug temperature as a result of engine heat of combustion.

5. A Diesel engine glow plug energization control circuit for use with Diesel engines having at least one glow plug comprising in combination with a circuit operating potential source;

means for producing a first electrical signal of a potential level indicative of desired glow plug temperature;

glow plug temperature simulator means energized by said operating potential source for producing a second electrical signal having a rate of increase of potential level substantially corresponding to the rate of increase of glow plug temperature and a rate of decrease of potential level substantially corresponding to the rate of decrease of glow plug temperature when said glow plug energizing circuit is completed and interrupted, respectively, whereby the instantaneous potential level of said second electrical signal is indicative of glow plug temperature at that instant; and

means effective to complete a glow plug energizing circuit across said operating potential source in response to the application of operating potential, and thereafter, being effective to alternately interrupt and complete said glow plug energizing circuit in response to the increase of said second electrical signal to a predetermined potential level and in response to the decrease of said second electrical signal to another lower potential level substantially equal to that of said first electrical signal, respectively, whereby said glow plug energizing circuit is cyclically completed and interrupted.

6. A Diesel engine glow plug energization control circuit for use with Diesel engines having at least one glow plug comprising in combination with a circuit operating potential source;

means for producing a first electrical signal of a potential level indicative of desired glow plug temperature;

glow plug temperature simulator means energized by said operating potential source for producing a second electrical signal having a rate of increase of potential level substantially corresponding to the rate of increase of glow plug temperature and a rate of decrease of potential level substantially corresponding to the rate of decrease of glow plug temperature when said glow plug energizing circuit is completed and interrupted, respectively, whereby the instantaneous potential level of said second electrical signal is indicative of glow plug temperature at that instant;

means effective to complete a glow plug energizing circuit across said operating potential source in response to the application of operating potential and, thereafter, being effective to alternately interrupt and complete said glow plug energizing circuit in response to the increase of said second electrical signal to a predetermined potential level and in response to the decrease of said second electrical signal to another lower potential level substantially equal to that of said first electrical signal, respectively, whereby said glow plug energizing circuit is cyclically completed and interrupted; and

means for preventing said second electrical signal from decreasing in potential level below a predetermined potential level indicative of glow plug temperature as a result of engine heat of combustion.

7. A Diesel engine glow plug energization control circuit for use with Diesel engines having at least one glow plug comprising in combination with a circuit operating potential source;

an electrically operable electrical switching arrangement effective to complete a glow plug energizing circuit across said operating potential source and to interrupt said energizing circuit;

means for producing, while said glow plug energizing circuit is interrupted, a first electrical signal of a potential level indicative of desired glow plug temperature;

means for producing, while said glow plug energizing circuit is completed, a second electrical signal of a potential level indicative of maximum glow plug temperature;

glow plug temperature simulator means energized by said operating potential source for producing a third electrical signal having a rate of increase of potential level substantially corresponding to the rate of increase of glow plug temperature and a rate of decrease of potential level substantially corresponding to the rate of decrease of glow plug temperature when said glow plug energizing circuit is completed and interrupted, respectively, whereby the instantaneous potential level of said third electrical signal is indicative of glow plug temperature at that instant; and

means effective upon the application of circuit operating potential to operate said electrical switching arrangement to complete said glow plug energizing circuit in response to the combination of said first and third electrical signals and, thereafter, being effective to operate said electrical switching arrangement to interrupt said glow plug energizing circuit in response to the combination of said second and third electrical signals when the potential of said third electrical signal has increased to a level substantially equal to that of said second electrical signal and to operate said electrical switching arrangement to complete said glow plug energizing circuit in response to the combination of said first and third electrical signals when the potential of said third electrical signal has decreased to a level substantially equal to that of said first electrical signal whereby said glow plug energizing circuit is cyclically completed and interrupted.

8. A Diesel engine glow plug energization control circuit for use with Diesel engines having at least one glow plug comprising in combination with a circuit operating potential source;

an electrically operable electrical switching arrangement effective to complete a glow plug energizing circuit across said operating potential source and to interrupt said energizing circuit;

means for producing, while said glow plug energizing circuit is interrupted, a first electrical signal of a potential level indicative of desired glow plug temperature;

means for producing, while said glow plug energizing circuit is completed, a second electrical signal of a potential level indicative of maximum glow plug temperature;

means for producing, while said glow plug energizing circuit is completed, a third electrical signal of a direct current potential level that is a function of the square of the output potential level of said operating potential source;

means responsive to said third electrical signal for producing a fourth electrical signal having a rate of increase of potential level substantially corresponding to the rate of increase of glow plug temperature and a rate of decrease of potential level substantially corresponding to the rate of decrease of glow plug temperature when said glow plug energizing circuit is completed and interrupted, respectively, whereby the instantaneous potential level of said fourth electrical signal is indicative of glow plug temperature at that instant; and

means effective upon the application of circuit operating potential to operate said electrical switching arrangement to complete said glow plug energizing circuit in response to the combination of said first and fourth electrical signals and, thereafter, being effective to operate said electrical switching arrangement to interrupt said glow plug energizing circuit in response to the combination of said second and fourth electrical signals when the potential of said fourth electrical signal has increased to a level substantially equal to that of said second electrical signal and to operate said electrical switching arrangement to complete said glow plug energizing circuit in response to the combination of said first and fourth electrical signals when the potential of said fourth electrical signal has decreased to a level substantially equal to that of said first electrical signal whereby said glow plug energizing circuit is cyclically completed and interrupted.

9. A Diesel engine glow plug energization control circuit for use with Diesel engines having at least one glow plug comprising in combination with a circuit operating potential source;

an electrically operable electrical switching arrangement effective to complete a glow plug energizing circuit across said operating potential source and to interrupt said energizing circuit;

means for producing, while said glow plug energizing circuit is interrupted, a first electrical signal of a potential level indicative of desired glow plug temperature;

means for producing, while said glow plug energizing circuit is completed, a second electrical signal of a potential level indicative of maximum glow plug temperature;

glow plug temperature simulator means energized by said operating potential source for producing a third electrical signal having a rate of increase of potential level substantially corresponding to the rate of increase of glow plug temperature and a rate of decrease of potential level substantially corresponding to the rate of decrease of glow plug temperature when said glow plug energizing circuit is completed and interrupted, respectively, whereby the instantaneous potential level of said third electrical signal is indicative of glow plug temperature at that instant;

means effective upon the application of circuit operating potential to operate said electrical switching arrangement to complete said glow plug energizing circuit in response to the combination of said first and third electrical signals and, thereafter, being effective to operate said electrical switching arrangement to interrupt said glow plug energizing circuit in response to the combination of said second and third electrical signals when the potential of said third electrical signal has increased to a level substantially equal to that of said second electrical signal and to operate said electrical switching arrangement to complete said glow plug energizing circuit in response to the combination of said first and third electrical signals when the potential of said third electrical signal has decreased to a level substantially equal to that of said first electrical signal whereby said glow plug energizing circuit is cyclically completed and interrupted; and

means for preventing said third electrical signal from decreasing in potential level below a predetermined potential level indicative of glow plug temperature as a result of engine heat of combustion.

10. A Diesel engine glow plug energization control circuit for use with Diesel engines having at least one glow plug comprising in combination with a circuit operating potential source;

an electrically operable electrical switching arrangement effective to complete a glow plug energizing circuit across said operating potential source and to interrupt said energizing circuit;

means for producing, while said glow plug energizing circuit is interrupted, a first electrical signal of a potential level indicative of desired glow plug temperature;

means for producing, while said glow plug energizing circuit is completed, a second electrical signal of a potential level indicative of maximum glow plug temperature;

means for producing, while said glow plug energizing circuit is completed, a third electrical signal of a direct current potential level that is a function of the square of the output potential level of said operating potential source;

means responsive to said third electrical signal for producing a fourth electrical signal having a rate of increase of potential level substantially corresponding to the rate of increase of glow plug temperature and a rate of decrease of potential level substantially corresponding to the rate of decrease of glow plug temperature when said glow plug energizing circuit is completed and interrupted, respectively, whereby the instantaneous potential level of said fourth electrical signal is indicative of glow plug temperature at that instant;

means effective upon the application of circuit operating potential to operate said electrical switching arrangement to complete said glow plug energizing circuit in response to the combination of said first and fourth electrical signals and, thereafter, being effective to operate said electrical switching arrangement to interrupt said glow plug energizing circuit in response to the combination of said second and fourth electrical signals when the potential of said fourth electrical signal has increased to a level substantially equal to that of said second electrical signal and to operate said electrical switching arrangement to complete said glow plug energizing circuit in response to the combination of said first and fourth electrical signals when the potential of said fourth electrical signal has decreased to a level substantially equal to that of said first electrical signal whereby said glow plug energizing circuit is cyclically completed and interrupted; and

means for preventing said fourth electrical signal from decreasing in potential level below a predetermined potential level indicative of glow plug temperature as a result of engine heat of combustion.