Gas Sensor Oil Removal via Localized Induction Heating
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing methods for manufacturing gas sensors, such as induction heating, often result in blackening of the protection cover, which increases the time required to reach operating temperature and decreases responsiveness due to oil absorption and potential damage from rapid temperature changes.
Innovation Solution
A method involving induction heating of a coil arranged around a cylindrical body to remove oil without directly heating the protection cover, using specific temperature control to prevent blackening and ceramic damage, ensuring efficient oil removal and maintaining detection accuracy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If induction heating is performed by applying current to a coil surrounding the protector, then oil adhering to the main metal fitting and protector is removed, but the protection cover becomes blackened
Solution Approach 1:
The patent applies local quality by positioning the induction heating coil to heat only specific portions of the assembly (main metal fitting and protector) while avoiding the protection cover. The coil is arranged to surround portions at the distal end side with respect to the proximal end of the flange portion, creating localized heating zones that remove oil without exposing the protection cover to temperatures that cause blackening.
Solution Approach 2:
The patent segments the heating process by dividing the assembly into different thermal zones. The induction heating coil is positioned to create distinct heated regions (main metal fitting and protector) and non-heated regions (protection cover). This segmentation allows selective oil removal from metal surfaces while preserving the protection cover's appearance and properties.
2Reliability
If the protection cover is blackened by induction heating, then oil is removed, but the time required for raising the temperature at the start of use increases and responsiveness decreases
Solution Approach 1:
By applying local quality through selective coil positioning, the patent removes oil from the main metal fitting and protector without blackening the protection cover. This prevents the formation of carbon deposits that would otherwise absorb radiant heat and delay temperature rise, thereby maintaining fast responsiveness while achieving effective oil removal.
3Productivity
If rapid temperature rise is used for efficient oil removal, then productivity increases, but the ceramic member may be damaged due to thermal shock
Solution Approach 1:
The patent applies parameter changes by controlling the temperature rise rate during induction heating. By adjusting the heating parameters to achieve a controlled temperature increase, the patent enables efficient oil removal while preventing thermal shock damage to the ceramic member. This optimization balances productivity with component reliability.
Solution Approach 2:
The patent employs beforehand cushioning by implementing controlled heating rates that prevent sudden thermal stress on the ceramic member. The induction heating process is designed to gradually increase temperature, cushioning the ceramic component against thermal shock while still achieving effective oil removal in a productive timeframe.
4Reliability
If the coil is arranged to surround the periphery of the protector, then oil removal is effective, but the protection cover absorbs radiant heat and blackens
Solution Approach 1:
The patent applies local quality by precisely positioning the induction heating coil to create localized heating fields. The coil surrounds portions at the distal end side with respect to the proximal end of the flange portion, generating heat only in the main metal fitting and protector regions. This localized approach eliminates radiant heat exposure to the protection cover, preventing blackening while maintaining effective oil removal.
Solution Approach 2:
The patent extracts the harmful radiant heat effect by removing the protection cover from the heating zone. By positioning the coil to exclude the protection cover from the electromagnetic field, the patent eliminates the source of radiant heat absorption that causes blackening, while still achieving oil removal from the metal components.
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 effectively removes oil from the gas sensor components without blackening the protection cover, enhancing the sensor's responsiveness and accuracy by controlling temperature rise rates and maintaining component integrity.
Implementation Method 1
induction heating the portion of the cylindrical body where the coil is arranged in the periphery by applying current to the coil
Implementation Method 2
induction heating by applying current to the coil
Data Source
Figure 1
Figure 2
Figure 3(a)~3(e)
AI summary
A coil 81 is arranged in a periphery of at least a portion of a cylindrical body 41 at the same side as the other end (upper end) of a sensor element 20 with respect to a protection cover 30 to avoid the protection cover 30 of an assembly 15, the portion of the cylindrical body 41 where the coil 81 is arranged in the periphery is induction heated by applying current to the coil 81, and hence oil adhering to the portion is removed.