Electromagnetic Fuel Injector With Linear Armature Closing Control
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Solution Overview
Problem
Existing electromagnetic fuel injectors face issues with high noise, accelerated degradation, and unpredictable fuel injection due to the use of gaseous fuels like hydrogen, which causes rapid armature impact and requires large passage areas, leading to complex and inaccurate magnetic force control.
Innovation Solution
The design incorporates a main and secondary electromagnet system where the secondary electromagnet lacks a fixed armature, providing a linear magnetic force to control the plunger's movement accurately, reducing impact velocity and wear, and is manufactured with simple, cost-effective components.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a single electromagnetic actuator with fixed armature is used, then the injection valve can be controlled, but the movable armature impacts violently against the fixed armature at high speed causing high noise and accelerated degradation
Solution Approach 1:
The single electromagnetic actuator is divided into two separate actuators: a first electromagnetic actuator with a first movable armature and first fixed armature, and a second electromagnetic actuator with a second movable armature and second fixed armature. This segmentation allows independent control of the opening and closing operations, enabling the plunger to be decelerated during closing to reduce impact velocity and noise while maintaining effective valve control.
Solution Approach 2:
The first electromagnetic actuator is activated in advance to open the injection valve before the second electromagnetic actuator is activated to close it. This preliminary action sequence allows the system to prepare for the closing operation by ensuring the valve is fully open, then control the closing speed to minimize impact when the plunger contacts the fixed armature.
2Quantity of substance
If the passage area for hydrogen is increased to inject sufficient mass, then the required hydrogen volume is reduced, but the plunger stroke length increases leading to higher impact speed
Solution Approach 1:
The system uses dynamic control of the second electromagnetic actuator to adjust the closing speed of the plunger based on its position. As the plunger approaches the fixed armature, the actuator reduces the closing velocity to minimize impact speed, while maintaining the longer stroke necessary for sufficient hydrogen mass injection through the larger passage area.
3Object-affected harmful factors
If magnetic force control is implemented to reduce impact speed, then the armature impact is reduced, but the control becomes extremely complex and inaccurate due to non-linear magnetic force
Solution Approach 1:
The control function is segmented between two electromagnetic actuators, with each responsible for specific phases of valve operation. The second actuator specifically handles the closing phase and can be controlled to reduce impact speed without requiring complex non-linear magnetic force control algorithms, as the segmentation simplifies the control requirements for each individual actuator.
Solution Approach 2:
The second electromagnetic actuator serves as an intermediary mechanism between the plunger's natural high-speed closing motion and the fixed armature. It provides a controlled deceleration phase, acting as a mediator that reduces impact speed through its magnetic field without requiring direct complex control of the plunger's non-linear magnetic forces.
4Device complexity
If a single electromagnetic actuator is used, then the device structure is simple, but the fuel injection amount exhibits randomness due to rebound phenomenon
Solution Approach 1:
The single actuator is segmented into two separate electromagnetic actuators, with the second actuator specifically designed to control the closing phase. This segmentation eliminates the rebound phenomenon that occurs with a single actuator, as the second actuator provides controlled deceleration during closing, ensuring consistent plunger stopping position and eliminating randomness in fuel injection amount.
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 solution achieves low noise and modest degradation by ensuring controlled plunger dynamics, reducing rebound phenomena and manufacturing complexity while maintaining precise fuel injection.
Implementation Method 1
The electromagnetic actuator comprises a (at least one) coil arranged externally and in a fixed position around the support body, a movable armature made of ferromagnetic material, which is rigidly connected to the plunger and is movably mounted within the support body, and a fixed armature (or bottom member) made of ferromagnetic material, which is arranged inside the support body in the area of the coil and is designed to magnetically attract the movable armature when the coil is energized.
Implementation Method 2
a movable armature made of ferromagnetic material, which is rigidly connected to the plunger and is movably mounted within the support body, and a fixed armature (or bottom member) made of ferromagnetic material
Data Source
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AI summary
An electromagnetic fuel injector (1) having: a tubular support body (4); an injection nozzle (3) arranged at one end of the support body (4); an injection valve (7) coupled to the injection nozzle (3); a plunger (8), which is movable, so as to adjust the fuel flow through the injection nozzle (3), between a closed position and an open position of the injection valve (7); an electromagnetic actuator (6) provided with at least one main electromagnet (11) and at least one secondary electromagnet (12); and a closing spring (10) configured to push the plunger (8) towards the closed position of the injection valve (7). The secondary electromagnet (12) has a secondary coil (17) and a secondary movable armature (18), which is arranged inside the support body (4), is movable, is integral to the plunger (8) and is magnetically coupled to the secondary coil (17) but lacks a secondary fixed armature, which is integral to the support body (4), is arranged inside the support body (4) and is magnetically coupled to the secondary movable armature (18) so as to magnetically attract the secondary movable armature (18).