Method for Determining the Heating Characteristic of a Glow Plug

• US 20100283489A1
• Filed: 04/29/2010
• Published: 11/11/2010
• Est. Priority Date: 05/05/2009
• Status: Active Grant

• Current Assignee: Borgwarner BERU Systems GmbH (BorgWarner Incorporated)
• Original Assignee: Borgwarner BERU Systems GmbH (BorgWarner Incorporated)
• Inventors: KERNWEIN, Markus
• Granted Patent: US 8,552,751 B2
• Time in Patent Office: Days
• US Class Current: 324/693
• CPC Class Codes: F02D 2041/2027 Control of the current by pulse width modulation or duty cycle control
• CPC Class Codes: F02P 17/12 Testing characteristics of the spark, ignition voltage or current testing of sparking plugs H01T13/60
• CPC Class Codes: F02P 19/022 using intermittent current supply
• CPC Class Codes: F02P 19/023 Individual control of the glow plugs
• CPC Class Codes: F02P 19/025 with means for determining glow plug temperature or glow plug resistance

Abstract

A method for determining a heating characteristic of a glow plug, wherein pulse-width-modulated voltage pulses are applied to the glow plug and an electric variable is measured repeatedly during a voltage pulse with the heating characteristic of the glow plug determined by evaluating the difference of successive measurement results of this variable.

Claims

1. A method for determining the heating characteristic of a glow plug, wherein pulse-width-modulated voltage pulses are applied to said glow plug, wherein an electric variable is measured repeatedly during a voltage pulse and the heating characteristic of the glow plug is determined by evaluating the difference of successive measurement results of this variable.

2. The method according to claim 1, wherein the electric variable is measured at the beginning and at the end of the voltage pulse in order to determine two successive measurement results of the electric variable.

3. The method according to claim 1, wherein, for evaluation, the difference is divided by a variable which is correlated with the energy input during a voltage pulse.

4. The method according to claim 3, wherein the variable correlated with the energy input is the pulse length.

5. The method according to claim 3, wherein the variable correlated with the energy input is the current intensity.

6. The method according to claim 3, wherein the variable correlated with the energy input is the on-board voltage.

7. The method according to claims 3, wherein the variable correlated with the energy input is the energy input itself.

8. The method according to claim 1, wherein the measured electric variable is the electric resistance.

9. The method according to claim 1, wherein the measurement results are each determined by a plurality of measurements.

10. The method according to claim 1, wherein, two measurement results of the electric variable are determined for each of a plurality of voltage pulses, and a plurality of difference values is calculated between successive measurement results and are evaluated.

11. The method according to claim 10, wherein an average value of several difference values is evaluated.

12. The method according to claim 1, wherein, for evaluation the difference or a variable calculated therefrom is compared with stored parameter values each of which represents a specific glow plug type with a known heating characteristic and the glow plug type and the heating characteristic of the glow plug are, thus, determined.

13. A control unit for glow plugs, wherein the control unit comprises a memory, with a program which performs a method according to any one of the preceding claims during operation being stored in said memory.