Induction Roller Temperature via Winding Impedance
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Solution Overview
Problem
Existing induction-heated roller apparatuses face challenges in accurately measuring the temperature of the roll main body due to difficulties in attaching temperature detecting elements and the limitations of non-contact methods, which can result in errors and low detection accuracy.
Innovation Solution
An induction-heated roller apparatus that calculates the temperature of the roll main body by determining the impedance of the winding and using relational data to correlate impedance with temperature, eliminating the need for a temperature detecting element, and includes an impedance correction mechanism to account for changes in power supply voltage and current penetration depth.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a temperature detecting element is attached to the roll main body, then temperature measurement is possible, but the contact state varies individually causing measurement errors and requiring sophisticated devices like rotary transformers
Solution Approach 1:
The patent replaces the mechanical contact-based temperature detection system with an electrical impedance measurement system. Instead of attaching physical temperature detecting elements to the rotating roll main body, the invention measures the impedance of the induction coil winding, which varies with temperature. This substitution eliminates the need for mechanical contact and complex rotary transformers, solving the contradiction between measurement accuracy and device complexity.
Solution Approach 2:
The patent introduces impedance as an intermediary parameter to indirectly measure temperature. Rather than directly measuring temperature with a detecting element on the roll, the system measures the electrical impedance of the induction coil, which changes in response to temperature variations of the roll main body. This intermediary measurement approach avoids the problems of direct contact measurement while maintaining accuracy.
2Ease of operation
If a radiation pyrometer is used to detect temperature non-contact, then no temperature detecting element is needed on the roll, but detection accuracy is low and affected by surface radiation rate
Solution Approach 1:
The patent replaces optical/non-contact radiation-based temperature detection with electrical impedance-based detection. Instead of using a radiation pyrometer that measures thermal radiation, the system measures the electrical impedance of the induction coil winding. This substitution provides contactless measurement like the pyrometer but achieves higher accuracy by measuring electrical properties that directly reflect temperature changes in the roll main body.
3Measurement precision
If impedance calculation is used to determine temperature, then no temperature detecting element is needed on the roll, but impedance varies with power supply conditions requiring correction mechanisms
Solution Approach 1:
The patent implements feedback mechanisms to monitor and correct impedance measurements. The system continuously monitors power supply voltage and current, and uses this feedback information to correct the impedance calculation. By incorporating feedback from power supply conditions, the system compensates for variations in impedance that are not related to temperature changes, maintaining measurement accuracy while managing the complexity through systematic correction.
Solution Approach 2:
The patent accounts for parameter changes in power supply conditions by dynamically adjusting the impedance calculation. Instead of using fixed impedance values, the system modifies the impedance measurement based on real-time power supply voltage and current parameters. This approach to handling parameter changes allows accurate temperature measurement while incorporating necessary correction mechanisms in a manageable way.
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 solution allows for accurate temperature calculation of the roll main body without a temperature detecting element, reducing measurement errors and improving detection precision by using impedance calculations and corrections based on power supply and material characteristics.
Implementation Method 1
a magnetic flux generating mechanism that is provided inside the roll main body and includes an iron core and a winding wound around the iron core
Implementation Method 2
a roll main body that is rotatably supported; a magnetic flux generating mechanism that is provided inside the roll main body
Implementation Method 3
induction-heated roller apparatus including: a roll main body that is rotatably supported; a magnetic flux generating mechanism
Implementation Method 4
an impedance calculation part that calculates impedance of the winding from an AC current value obtained by an AC current detecting part adapted to detect AC current flowing through the winding and an AC voltage value obtained by an AC voltage detecting part adapted to detect AC voltage applied to the winding
Data Source
AI summary
The present invention intends to eliminate the need for a temperature detecting element adapted to measure the temperature of a roll main body in an induction-heated roller apparatus, and includes an impedance calculation part that calculates the impedance of a winding, a relational data storage part that stores relational data indicating the relationship between the impedance of the winding and the temperature of the roll main body, and a roll temperature calculation part that calculates the temperature of the roll main body from the impedance obtained by the impedance calculation part and the relational data stored in the relational data storage part.