Fuel Injection Controller Spill Valve Noise Reduction
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Solution Overview
Problem
Existing fuel injection control techniques for engines are limited in reducing the operation sound of the spill valve to a narrow range and struggle to maintain stable fuel supply across a wide engine driving range while achieving stable combustion.
Innovation Solution
A fuel-injection controller that adjusts the operation frequency and timing of the spill valve based on engine load and speed, allowing the air intake passage fuel injection device and inside cylinder fuel injection device to work in conjunction to control fuel injection, reducing spill valve operation frequency during low load driving and increasing it during high load driving, and varying valve closing timing to optimize fuel pressure and reduce friction.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the spill valve is operated frequently to maintain stable fuel injection, then fuel injection stability is improved, but operation sound of the spill valve increases
Solution Approach 1:
The spill valve operation frequency is made dynamic rather than fixed. The control device adjusts the spill valve operation frequency based on engine load and rotational speed, operating it frequently when stable fuel injection is critical (high load) and less frequently when noise reduction is prioritized (low to middle load), thus resolving the contradiction between injection stability and noise reduction
Solution Approach 2:
The operational parameters of the spill valve (operation frequency) are changed based on engine conditions. By varying the spill valve operation frequency according to engine load and rotational speed maps, the system achieves stable fuel injection when needed while reducing operation sound during low-to-middle load conditions
2Object-generated harmful factors
If the spill valve is stopped to reduce operation sound, then spill valve operation sound is reduced, but fuel injection stability deteriorates
Solution Approach 1:
The spill valve operation is made dynamic, switching between stopped and operating states based on engine conditions. The control device determines optimal operation frequency from maps based on engine load and rotational speed, stopping the spill valve during low-to-middle load conditions to reduce noise while maintaining injection stability through alternative control strategies
3Object-generated harmful factors
If the spill valve operation frequency is reduced to reduce noise, then operation sound is reduced, but fuel supply adequacy deteriorates
Solution Approach 1:
The spill valve operation frequency parameter is changed based on engine conditions. The control device selects appropriate operation frequencies from pre-defined maps based on engine load and rotational speed, reducing frequency during low-to-middle load to reduce noise while compensating fuel supply through optimized injection timing and duration
Solution Approach 2:
The system uses feedback from engine load and rotational speed sensors to dynamically adjust spill valve operation frequency. The control device continuously monitors engine conditions and adjusts the spill valve operation accordingly, ensuring adequate fuel supply is maintained even when operation frequency is reduced for noise reduction
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 approach effectively reduces spill valve operation noise across a wide engine driving range, maintains high discharge pressure, and improves fuel efficiency and output power by optimizing fuel injection modes and valve operations.
Implementation Method 1
drive of the cam with rotation of the drive shaft allows a plunger to reciprocate in a compressing chamber to pressurize fuel introduced in the compressing chamber and discharge the fuel under high pressure
Implementation Method 2
the high pressure pump includes a spill valve that is an opening/closing valve of an electromagnetic drive type
Data Source
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AI summary
There is provided a fuel-injection controller for an engine (1) that includes an air intake passage fuel injection valve (10) for injecting fuel to an intake port (4), and an inside cylinder fuel injection valve (11) for injecting fuel pressurized by a high pressure pump (20) into a combustion chamber (3). The high pressure pump (20) includes a plunger that reciprocates four times in a compressing chamber per one rotation of a drive shaft driven by the engine (1) to pressurize fuel in the compressing chamber, and a spill valve that opens and closes a supply passage of fuel to the compressing chamber. In addition, the fuel-injection controller for an engine includes a control unit (32) that controls driving of the spill valve. When the inside cylinder fuel injection valve (11) injects fuel, the control unit (32) changes the control of the spill valve to be driven twice per one rotation of the drive shaft during middle load driving with a load lower than a load during high load driving from four times per one rotation of the drive shaft during the high load driving.