Ceramic Glow Plug Superproportional Voltage Heating
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Ceramic glow plugs fail to achieve the desired long service life due to rapid heating processes that often result in overheating and material damage, despite efforts to prevent temperature overshooting by gradually reducing electric voltage during heating.
Innovation Solution
A method where the electric voltage increases superproportionally at the beginning of the heating process, starting from a lower base voltage and reaching a maximum value quickly, followed by a potential decrease to maintain the operating temperature, using a pulse-width modulation process to achieve rapid heating while minimizing material stress.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If the electric voltage is gradually reduced during the heating-up process to prevent temperature overshooting, then the temperature control is improved, but the heating speed decreases and service life is not maximized
Solution Approach 1:
The patent inverts the conventional voltage control approach by initially increasing the voltage beyond nominal values (e.g., to 1.2-1.5 times nominal) during the first 0.1-0.3 seconds of heating, then subsequently reducing it. This inversion allows rapid heating followed by temperature stabilization, resolving the contradiction between heating speed and temperature control.
Solution Approach 2:
The patent implements dynamic voltage control where the voltage profile changes over time: starting with a high voltage surge, then transitioning to a reduced voltage level. This dynamic adjustment optimizes both heating speed during the initial phase and temperature control during the stabilization phase, thereby extending service life.
2Speed
If full voltage is applied at the onset of heating to achieve rapid heating, then heating speed is improved, but local overheating and material damage occur reducing service life
Solution Approach 1:
The patent applies a preliminary high voltage surge at the very beginning of heating (first 0.1-0.3 seconds) when the ceramic material is still cold and has lower resistance. This preliminary action achieves rapid initial heating without causing damage, as the brief duration prevents thermal stress accumulation. After this preliminary phase, voltage is reduced to maintain temperature without overheating.
3Productivity
If the voltage is increased superproportionally at the beginning of heating, then heating efficiency is improved, but voltage control complexity increases
Solution Approach 1:
The patent employs periodic voltage control with distinct phases: an initial high-voltage surge phase lasting 0.1-0.3 seconds, followed by a reduced voltage phase. This periodic structure simplifies control implementation while achieving superior heating efficiency, as each phase serves a specific purpose in the heating process.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach significantly extends the service life of ceramic glow plugs by allowing rapid heating without material damage, as the voltage increase generates local current paths that manage temperature effectively, ensuring efficient heating to the desired operating temperature.
Implementation Method 1
the electric voltage increases superproportionally to the elapsed heating-up time... the voltage increase generates local current paths that manage temperature effectively
Implementation Method 2
Caused by the temperature, the electric resistance increases during the heating-up process so that, in order to heat up to a desired operating temperature as rapidly as possible, the electric voltage can also be increased without damaging the material
Data Source
AI summary
Herein is described a method for the heating-up of a ceramic glow plug by applying a variable electric voltage to the glow plug. In accordance with the invention it is provided that, starting from a base value, the electric voltage increases in a time-averaged manner superproportional to the elapsed heating-up time. The invention relates also to a glow plug control unit for carrying out of such a method.