Glow plug controller

• US 5,327,870 A
• Filed: 08/26/1993
• Issued: 07/12/1994
• Est. Priority Date: 10/31/1991
• Status: Expired due to Term

• Current Assignee: Uusi LLC (Nartron Corporation)
• Original Assignee: Nartron Corporation
• Inventors: Boisvert, Mario P., Kienitz, Thomas P., Zoerner, Marty M.
• Primary Examiner(s): Dolinar, Andrew M.
• Application Number:
  US08/112,651
• Time in Patent Office: 320 Days
• Field of Search: 123/145 A, 123/179.6, 123/179.21, 361/264, 361/399, 361/752, 361/757, 361/265
• US Class Current: 123/145.00A
• 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: F02F 2007/0092 Transparent materials
• CPC Class Codes: F02P 19/02 electric, e.g. layout of circuits of apparatus having glowing plugs

Abstract

An improved glow plug controller for a diesel engine is disclosed. The glow plug controller has a novel packaging, and means for facilitating rapid and inexpensive assembly. A novel two-chamber tubular housing includes a smaller first chamber having a threaded exterior surface for engagement with a threaded hole in an engine block. This first chamber communicates with a larger second chamber also defined by the housing. A connector bearing conductive connector pins is provided for sealing the open end of the larger chamber. The connector includes a pair of support rails for engaging a piece of circuit board on which glow plug circuitry resides. In assembly, the circuit board is first mounted on the support rails which are subsequently inserted into the larger second chamber when the connector is affixed to the open end of the second chamber. The connector pins are conductively coupled to glow plug circuitry on the circuit board via portions of conductive foil on a surface of the circuit board. Each area of foil is aligned with a respective one of the connector pins, and the connector pins are directly conductively coupled to the foil areas by soldering. A unique short circuit cut-off is provided wherein a short circuit in the glow plug relay control disables application of power to the relay control circuit, and the power is re-enabled if the short circuit condition is remedied and the power to the glow plug controller is toggled.

Claims

1. A glow plug controller comprising:

a) a generally tubular housing having a wall defining a first chamber and a second chamber communicating with said first chamber, the portion of the outer surface of the wall which defines said first chamber being a threaded portion for threaded engagement in a hole;

b) glow plug controller circuitry including a temperature sensor located within said threaded portion and circuitry for controlling glow plug operation as a function of sensed temperature, said temperature sensor being located within said first chamber, and wherein glow plug controller circuitry is located with said second chamber of said housing; and

c) means for conductively coupling said glow plug controller circuitry to other circuitry external to said housing.

2. The glow plug controller of claim 1, wherein said housing comprises aluminum.

3. The glow plug controller of claim 1, further comprising:

potting compound located within said housing for rigidly positioning said temperature sensor and said glow plug controller circuitry within said housing.

4. The glow plug controller of claim 3, wherein:

said potting compound has a relatively high thermal conductivity.

5. The glow plug controller of claim 1, wherein:

the outer surface of the wall defining said second chamber of said housing being configured to define a region of generally hexagonal cross-section for facilitating engagement of said housing by a tool.

6. The glow plug controller of claim 1, further comprising:

the outer end of said first chamber of said tubular housing being sealed.

7. The glow plug controller of claim 1, wherein said means for conductively coupling said glow plug controller circuitry to other circuitry external to said housing comprises:

a) a shell connector adapted for covering the external end of said second chamber, and

b) a plurality of connector pins extending from locations external to said housing to locations within said second chamber.

8. The glow plug controller of claim 1, wherein:

said second chamber is larger than said first chamber.

9. The glow plug controller of claim 1, wherein:

a) said glow plug controller circuitry comprises power supply circuitry, and

b) said power supply circuitry is located within said housing at a location remote from said temperature sensor.

10. The glow plug controller of claim 9, wherein:

said power supply circuitry comprises a power transistor and a resistor.

11. The glow plug controller of claim 9, wherein:

said power supply circuitry is located proximate said conductive coupling means.

12. A glow plug controller for controlling application of electric power to a glow plug by controlling a glow plug relay coil circuit, said glow plug controller comprising:

a) a temperature sensor;

b) glow plug controller circuitry for controlling application of electric power to the glow plug as a function of sensed temperature;

c) circuitry for detecting a short circuit current in the glow plug relay coil circuit; and

d) circuitry for disabling application of power to said glow plug relay circuit in response to the detection of a short circuit current in said relay coil circuit.

13. The glow plug controller of claim 12, further comprising:

circuitry for re-enabling the application of power to said glow plug relay coil circuit in response to removal of power from said glow plug controller and the re-application of power to said glow plug controller.

14. A glow plug controller comprising:

a) a temperature sensor;

b) glow plug controller circuitry for controlling application of power to a circuit feeding a glow plug, as a function of sensed temperature, said glow plug controller circuitry being coupled to said temperature sensor and including capacitive impedances, and

c) wherein capacitive impedance in said glow plug controller circuitry is embodied by capacitance multiplier circuitry.

15. A glow plug controller comprising:

a) a generally tubular housing having a wall defining a first chamber and a second chamber communicating with said first chamber, the outer surface of the wall defining said first chamber being threaded for threaded engagement in a hole;

b) glow plug controller circuitry comprising a printed circuit board and including a temperature sensor and circuitry for controlling glow plug operation as a function of sensed temperature, said temperature sensor being located within said first chamber, and wherein glow plug controller circuitry is located within said second chamber of said housing; and

,

c) means for conductively coupling said glow plug controller circuitry to other circuitry external to said housing.

16. A glow plug controller comprising:

a) a generally tubular housing having a wall defining a first chamber and a second chamber communicating with said first chamber, the outer surface of the wall defining said first chamber being threaded for threaded engagement in a hole;

b) glow plug controller circuitry including a temperature sensor and circuitry for controlling glow plug operation as a function of sensed temperature, said temperature sensor being located within said first chamber, and wherein glow plug controller circuitry is located within said second chamber of said housing;

c) said glow plug controller circuitry comprising a printed circuitry board, said board defining a major portion adapted for insertion into said second chamber of said housing, said board further defining a protrusion positioned and sized for extension into said first chamber when said major portion of said circuit board is inserted into said second chamber;

d) said protrusion bearing said temperature sensor and said major portion bearing glow plug controller circuitry; and

,

e) means for conductively coupling said glow plug controller circuitry to other circuitry external to said housing.

17. The glow plug controller of claim 16, further comprising:

a) said glow plug controller circuitry including two separate circuit boards; and

,

b) a ribbon cable conductively coupling circuitry on one of said boards with circuitry on the other of said boards.

18. The glow plug controller of claim 17, wherein:

said two circuit boards are disposed within said second chamber in a closely spaced parallel stacked arrangement.

19. A glow plug controller for use in connection with a diesel engine having a block, said glow plug controller comprising:

a) a housing adapted for mounting on the block;

b) a temperature sensor and glow plug controller circuitry disposed within said housing, said temperature sensor not being in direct mechanical contact with said housing, but being thermally coupled to said housing by a path of low thermal resistance; and

c) means for facilitating the conductive coupling of the glow plug controller circuitry to circuitry external to said housing.

20. A glow plug controller comprising:

a) a generally tubular housing having a wall defining a first chamber and a second chamber communicating with said first chamber, the outer surface of the wall defining said first chamber being threaded for threaded engagement in a hole;

b) glow plug controller circuitry including a thermistor temperature sensor and circuitry for controlling glow plug operation as a function of sensed temperature, said temperature sensor being located within said first chamber, and wherein glow plug controller circuitry is located within said second chamber of said housing, and

c) means for conductively coupling said glow plug controller circuitry to other circuitry external to said housing.

21. A glow plug controller for use in connection with a diesel engine having a block defining a jacket for engine coolant, said glow plug controller comprising:

a) a housing comprising aluminum-containing material having a high thermal conductivity;

b) circuitry including a temperature sensor and glow plug controller circuitry disposed within said housing, said housing containing potting compound having a high thermal conductivity extending between said sensor and said housing; and

c) means facilitating the coupling of said glow plug controller circuitry to circuitry external to said housing.