Motor Valve Control Device Low Temperature Malfunction Prevention

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Solution Overview

Problem

The electric valve in air conditioning systems malfunctions at low temperatures due to the increased viscosity of refrigerant lubricant, which interferes with the rotation of the magnet rotor.

Innovation Solution

An electric valve control device that includes a temperature sensor to detect ambient temperature and performs a heat-generating operation by energizing the stator until the magnet rotor rotates normally, thereby reducing the viscosity of the refrigerant lubricant.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If the electric valve is used at low temperatures, then the valve can operate in cold environments, but the viscosity of the lubricant increases causing malfunction

Engineering Contradiction:
Improveoperating temperature rangeVSAvoidvalve operation reliability
Core Design Contradiction:
TemperatureVSReliability

Solution Approach 1:

The control device performs a heat-generating operation before the valve operation to pre-heat the lubricant and reduce its viscosity. This preliminary heating action ensures that the lubricant is in an appropriate viscosity state before the valve needs to operate, preventing malfunction in cold environments.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The control device changes the temperature parameter of the lubricant by generating heat through the stator coil. By controlling the temperature of the lubricant, the device changes its viscosity parameter from a high-viscosity state (at low temperature) to a lower-viscosity state suitable for proper valve operation.

Inventive Principle:
Principle #35Parameter changes

2Reliability

If the stator is energized to generate heat, then the lubricant viscosity is reduced, but energy is consumed

Engineering Contradiction:
Improvemagnet rotor rotation reliabilityVSAvoidenergy consumption
Core Design Contradiction:
ReliabilityVSUse of energy by moving object

Solution Approach 1:

The control device applies partial heating action by energizing the stator coil only for the duration and intensity necessary to reduce lubricant viscosity to the required level. The device monitors the heating process and stops when the viscosity is sufficient, avoiding excessive energy consumption while ensuring reliable rotor rotation.

Inventive Principle:
Principle #16Partial or excessive action

Solution Approach 2:

The heat-generating operation is performed periodically or intermittently based on temperature conditions rather than continuously. The control device activates heating only when low temperature conditions are detected and deactivates it when the lubricant reaches appropriate viscosity, optimizing energy usage.

Inventive Principle:
Principle #19Periodic action

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 heat-generating operation effectively reduces the viscosity of the refrigerant lubricant, allowing the magnet rotor to rotate normally and preventing malfunction of the electric valve at low temperatures.

Implementation Method 1

perform a heat-generating operation to cause the stator to generate heat when the temperature is lower than a reference temperature

Methodology Applied
Scientific EffectElectromagnetic heating: Dielectric Heating

Data Source

PatentEP4534878A1Motor-operated valve control device and motor-operated valve device
Publication Date: 2025.04.09 FUJIKOKI CORP
  • EP4534878A1 patent drawingFigure 1
  • EP4534878A1 patent drawingFigure 2
  • EP4534878A1 patent drawingFigure 3

AI summary

[Object] To provide an electric valve control device and an electric valve device that are capable of suppressing malfunction of an electric valve at low temperatures. [Solution] An electric valve control device (100) obtains temperature (K) based on a signal from a temperature sensor (126) disposed outside a can (20) and enters a preparation mode when the temperature (K) is lower than a reference temperature (Kr). When a magnet rotor (31) does not rotate normally in the preparation mode, the electric valve control device (100) performs a heat-generating operation to cause a stator (60) to generate heat until the magnet rotor (31) rotates normally. When the magnet rotor (31) rotates normally in the preparation mode, the electric valve control device (100) enters a standby mode.