Glow plug controller
First Claim
1. Apparatus for governing application of electrical power to a plurality of glow plugs in a diesel engine that applies motive power to a motor vehicle, said apparatus comprising:
- a) a temperature sensor for producing a temperature signal corresponding to a temperature at a region of said diesel engine;
b) a programmable controller for controlling application of electrical power to the glow plugs of said diesel engine;
said programmable controller including i) a power input coupled to a motor vehicle battery;
ii) a temperature input coupled to the temperature sensor for monitoring said temperature signal iii) a stored program for determining a glow plug pre-glow period as a function of sensed temperature from the temperature sensor;
iv) an enable input to signal the stored program to determine a pre-glow time period and v) an output for producing a glow plug control signal during a pre-glow time period determined by the stored program in response to receipt of the enable input, said stored program distinguishing between two different signals at the enable input to allow the motor vehicle operator to manually override the pre-glow energization time period;
c) output circuitry coupled to the programmable controller for responding to the glow plug control signal from the programmable controller and applying electrical power to the glow plugs;
d) a waterproof housing for the programmable controller that is attached to the diesel engine for enclosing the programmable controller; and
e) structure for supporting the glow plug controller and the temperature sensor within the waterproof housing.
3 Assignments
1 Petition
Accused Products
Abstract
An improved glow plug controller is disclosed. The glow plug controller includes an analog temperature sensor, circuitry for converting an analog temperature signal to digital form, a microprocessor for analyzing temperature and other operating parameters and for controlling glow plugs and monitoring indicators in accordance with algorithms defined in the microprocessor. The temperature and control signals from the microprocessor are converted to analog form and applied to actuate glow plugs and indicators in accordance with determinations made by the microprocessor. A specific embodiment includes a manual override for facilitating operation even if the microprocessor should fail. A false temperature input is provided so that a false temperature representation can be directly applied to the microprocessor for factory and service center testing of microprocessor operation. Glow plug operation is controlled by way of a relay and multiple, independently fused glow plug circuits. Diagnostic means are provided for indicating to an operator when a glow plug short circuit has caused a fuse to open the glow plug circuit, and to indicate as well the number of such circuits which have been opened by short circuit malfunctions. Disabling means are provided for cutting off power to the glow plugs in response to engine temperature exceeding a predetermined maximum of 88° Celsius. The programmed microprocessor includes means for establishing a preglow period as a function of engine temperature, and for initiating the afterglow in response to the cessation of cranking the engine.
26 Citations
14 Claims
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1. Apparatus for governing application of electrical power to a plurality of glow plugs in a diesel engine that applies motive power to a motor vehicle, said apparatus comprising:
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a) a temperature sensor for producing a temperature signal corresponding to a temperature at a region of said diesel engine; b) a programmable controller for controlling application of electrical power to the glow plugs of said diesel engine;
said programmable controller including i) a power input coupled to a motor vehicle battery;
ii) a temperature input coupled to the temperature sensor for monitoring said temperature signal iii) a stored program for determining a glow plug pre-glow period as a function of sensed temperature from the temperature sensor;
iv) an enable input to signal the stored program to determine a pre-glow time period and v) an output for producing a glow plug control signal during a pre-glow time period determined by the stored program in response to receipt of the enable input, said stored program distinguishing between two different signals at the enable input to allow the motor vehicle operator to manually override the pre-glow energization time period;c) output circuitry coupled to the programmable controller for responding to the glow plug control signal from the programmable controller and applying electrical power to the glow plugs; d) a waterproof housing for the programmable controller that is attached to the diesel engine for enclosing the programmable controller; and e) structure for supporting the glow plug controller and the temperature sensor within the waterproof housing. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
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10. Apparatus for governing application of electrical power to a one or more glow plugs in a diesel engine, the diesel engine having associated therewith a starter for starting the engine, said apparatus comprising:
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a) a user actuated switch for applying power to the glow plugs prior to starting the engine; b) user actuated apparatus and circuitry for actuating said starter and for producing a cranking signal only when said starter is operating; c) a temperature sensor mounted to the diesel engine for monitoring an ambient temperature prior to starting of the diesel engine; and d) glow plug control circuitry comprising; i) a programmable controller electrically connected to said temperature sensor and to said user actuated switch having a stored program that responds to actuation of said switch by calculating a preglow period if a sensed temperature as indicated by a signal from the temperature sensor is below a first set point temperature; and ii) output circuitry coupled to the programmable controller responsive to the cessation of said cranking signal to apply electrical power to said glow plug during an afterglow period initiated in response to cessation of said cranking signal. - View Dependent Claims (11, 12, 13)
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14. Apparatus for governing application of electrical power to a one or more glow plugs in a diesel engine, the diesel engine having associated therewith a starter for starting the engine, said apparatus comprising:
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a) a user actuated switch for applying power to the glow plugs prior to starting the engine; b) user actuated apparatus and circuitry for actuating said starter and for producing a cranking signal only when said starter is operating; c) a temperature sensor mounted to the diesel engine for monitoring an ambient temperature prior to starting of the diesel engine; and d) glow plug control circuitry electrically connected to said temperature sensor, to said user actuated switch, and to the circuitry for actuating the starter;
said glow plug control circuitry distinguishing between momentary and continuous user operation of the user actuated switch in responding to first and second set point temperatures that are sensed by the temperature sensor;
wherein the control circuitry responds to either continuous or momentary actuation of said user actuated switch to apply electrical power to said glow plugs during a preglow period if the sensed temperature is below both the first and the second set point temperatures but wherein the control circuitry responds to only continuous actuation of sad user actuated switch to apply electrical power to said glow plugs during a preglow period if the sensed temperature is above a first set point temperature but below the second set point temperature;e) said glow plug control circuitry responsive to the cessation of said cranking signal to apply electrical power to said glow plug during an afterglow period in response to cessation of said cranking signal.
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Specification