Regenerative Switching Element Abnormality Detection in Fuel Injection Valves
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Solution Overview
Problem
Existing electromagnetic valve driving devices do not effectively detect abnormalities in synchronous switching elements, which can lead to excessive current flow due to removed regenerative current paths and back electromotive voltage issues.
Innovation Solution
Incorporating a regenerative switching element between the solenoid coil and ground, along with a control unit that includes a voltage detection unit and an abnormality detection unit to monitor the voltage and control the switching elements, allowing for detection of abnormalities before fuel injection valve operation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If a synchronous switching element is used to enable regenerative current to return to the solenoid coil, then energy efficiency is improved, but the risk of excessive current flow increases when the switching element fails
Solution Approach 1:
A diode is introduced as an intermediary component between the control unit and the solenoid coil. This diode acts as a one-way valve for current flow, allowing current to flow from the control unit to the solenoid coil but blocking any reverse current. This protects the control unit from excessive current while maintaining the regenerative braking function through the synchronous switching element.
Solution Approach 2:
The diode is pre-installed in the circuit path before the solenoid coil, creating a permanent protective barrier against reverse current. This preliminary protective measure ensures that even if the synchronous switching element fails, the control unit is automatically protected without requiring additional detection or response time.
2Reliability
If the drain terminal of the synchronous switching element opens due to abnormality, then the regenerative current path is removed, but excessive current flows from the control unit to the solenoid coil
Solution Approach 1:
The diode converts the potentially harmful reverse current into a blocked current path. When the synchronous switching element fails and attempts to create a reverse current path, the diode automatically blocks it, transforming what would be a harmful condition into a safe state without requiring active detection or control.
3Measurement precision
If voltage detection is performed continuously to detect switching element abnormalities, then detection accuracy is improved, but energy consumption increases
Solution Approach 1:
Instead of continuous monitoring, the system performs voltage detection periodically at specific moments: when the ignition switch is turned on and before each fuel injection operation. This periodic detection approach maintains adequate monitoring capability while significantly reducing energy consumption compared to continuous monitoring.
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
Enables the detection of synchronous switching element abnormalities, preventing excessive current flow and ensuring safe operation of the fuel injection valve by stopping the driving mechanism when an abnormality is detected.
Implementation Method 1
a current generated due to a back electromotive voltage of the solenoid coil (hereinafter referred to as a 'regenerative current')
Data Source
AI summary
An electromagnetic valve driving device which drives a fuel injection valve having a solenoid coil, includes: a regenerative switching element disposed between a first end portion of the solenoid coil and the ground; and a control unit configured to control the regenerative switching element to be in an ON state or an OFF state, wherein the control unit includes: a voltage detection unit configured to detect a voltage of the first end portion of the solenoid coil; and an abnormality detection unit configured to detect an abnormality of the regenerative switching element on the basis of the voltage detected by the voltage detection unit.