Temperature Sensor Tip Manufacturing Using Ceramic Powder Filling
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Solution Overview
Problem
Existing methods for manufacturing temperature sensors are difficult to automate, prone to leakage under high temperature conditions, limited in length and diameter flexibility, and fail to improve sensitivity and response time effectively.
Innovation Solution
A method involving a cylinder-shaped container filled with thermal conductive ceramic powder and a mineral powdered material of lower conductivity, allowing for the creation of a sensing tip with a distal end that is highly thermal conductive and resistant to high temperatures, while enabling universal length and diameter options, and reducing manufacturing costs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Extent of automation
If manual operations are used in the manufacturing process, then the process can be completed, but automation is difficult to achieve
Solution Approach 1:
The manufacturing process is divided into distinct sequential steps: introducing wires into the support tube, folding wire ends to form hot junction, filling with insulating material, and closing the tube. Each step is designed to be independently performable and suitable for automated execution, eliminating the need for complex manual operations while maintaining manufacturing feasibility.
2Reliability
If the protective sleeve is folded and welded to close the distal end, then the structure is sealed, but leakage occurs under high temperature conditions
Solution Approach 1:
The welding operation is completely removed from the distal end closing process. Instead of welding the protective sleeve folds, the invention uses insulating material filling that is mechanically contained, eliminating the thermal stress and potential failure points associated with welded joints in high temperature environments.
Solution Approach 2:
The closing method transitions from a thermal process (welding) to a mechanical containment process (filling and sealing). This parameter change in the closing mechanism eliminates the creation of thermal stress concentrations and potential leakage paths that occur with welded folds under high temperature conditions.
3Adaptability or versatility
If a support tube of fixed length is used, then the manufacturing process is simplified, but the temperature sensor length cannot be adjusted
Solution Approach 1:
The support tube length is made variable rather than fixed. The method allows selection of different support tube lengths based on the desired final sensor length, and the filling process adapts to any tube length. This dynamic approach enables customization of sensor length without requiring different manufacturing processes for each length.
4Speed
If the distal end is swaged to improve response time, then thermal conductivity increases, but the structural integrity may be compromised
Solution Approach 1:
The swaging operation is applied selectively only to the distal end portion of the support tube, leaving the proximal end and connection areas unaffected. This localized application improves thermal conductivity where needed for faster response time while preserving the structural integrity and wall thickness in areas requiring strength for mechanical support and connection.
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
The method results in a sensing tip that is resistant to high stress and temperature, offers improved thermal conductivity, reduced response time, and is cost-effective, with enhanced mechanical properties and flexibility in dimensions.
Implementation Method 1
The method involves a cylinder-shaped container filled with thermal conductive ceramic powder and a mineral powdered material of lower conductivity
Implementation Method 2
applying to the sensing tip a radial shrinking strength, thus forming a shrunk sensing tip
Implementation Method 3
two wires forming a thermocouple... connecting them by electric welding to form the hot junction of the thermocouple
Data Source
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AI summary
The invention relates to a method for manufacturing a sensing tip (1) for a temperature sensing device (10), characterized in that it comprises the steps of: a) providing with a thermocouple extending longitudinally and coaxially at least in part inside a cylinder-shaped container presenting one closed longitudinal end, named distal end and one open longitudinal end, named proximal end opposite to said distal end; a welding, named hot junction, of the thermocouple being positioned in the cylinder-shaped container at said distal end of the cylinder-shaped container, and; b) filling a free space extending inside the cylinder-shaped container with a quantity of at least one mineral powdered material, at least one part of the at least one mineral powdered material being a thermal conductive ceramic powder, said thermal conductive ceramic powder forming a layer, named distal layer, of said thermal conductive ceramic powder at least at said distal end; thus forming the sensing tip (1). The invention extends to a temperature sensing device (10) comprising said sensing tip (1) and to a combustion engine comprising the same and to an engine vehicle comprising said combustion engine.