Transfer Pump Fuel Flow Regulation via Solenoid Oil Diversion
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Solution Overview
Problem
Existing transfer pumps for high-pressure gasoline injection in internal combustion engines face challenges in regulating fuel flow and preventing gasoline persistence in the circuit after engine stoppage, requiring complex solutions involving partial recycling and oil supply regulation.
Innovation Solution
A transfer pump design utilizing a piston and deformable bellows, where oil is diverted to a chamber without pressure to control the piston's stroke and fuel quantity delivered to the rail, employing a solenoid valve to manage oil flow and prevent pressure increase, allowing for adjustable fuel delivery and efficient operation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If partial recycling of fuel flow downstream of the pump is used to regulate fuel flow, then fuel flow regulation is achieved, but device complexity increases
Solution Approach 1:
The patent introduces oil as an intermediary substance to control the piston's movement. The solenoid valve regulates oil flow to the piston chamber, which in turn controls the piston stroke and thereby the fuel pumping action. This intermediary control mechanism simplifies the overall system by decoupling the direct fuel flow control from the pumping mechanism.
2Ease of operation
If fuel flow regulation is performed by acting on oil supply to the transfer pump, then fuel flow regulation is achieved, but device complexity increases
Solution Approach 1:
The patent replaces direct mechanical control of fuel flow with a solenoid-controlled oil delivery system. The solenoid valve, controlled by electrical signals, regulates oil flow to the piston, which mechanically controls the fuel pumping. This substitution of electrical control for mechanical fuel flow control simplifies the regulation mechanism.
3Productivity
If the piston delivers oil into the deformable element under high pressure, then fuel pumping efficiency is improved, but fuel persistence in the circuit after engine stoppage occurs
Solution Approach 1:
The patent employs a deformable bellows element that dynamically changes volume in response to pressure variations. The bellows expands when oil pressure increases and contracts when pressure decreases, allowing the system to adapt its fuel delivery characteristics in real-time and prevent fuel persistence by returning excess fuel to the tank.
4Ease of operation
If the solenoid valve is normally open to divert oil without pressure, then fuel flow control is simplified, but fuel delivery quantity decreases
Solution Approach 1:
The patent uses periodic activation of the solenoid valve to control fuel delivery. The valve alternates between open and closed states, creating periodic cycles of fuel pumping. During the closed state, fuel is pumped to the rail; during the open state, oil is diverted without pressurizing the fuel. This periodic action allows precise control of fuel quantity while maintaining system simplicity.
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 design effectively regulates fuel flow and prevents fuel persistence, enhancing engine efficiency by allowing precise control of high-pressure fuel injection, improving resistance and longevity of components, and maintaining high-pressure injection during engine stoppages.
Implementation Method 1
A transfer pump design utilizing a piston and deformable bellows, where oil is diverted to a chamber without pressure to control the piston's stroke and fuel quantity delivered to the rail, employing a solenoid valve to manage oil flow
Implementation Method 2
the deformations of this member being caused by a hydraulic pump with high pressure
Implementation Method 3
an elastically deformable member, resistant to the attacks of modern fuels
Implementation Method 4
The discharge pipe 21 includes a non-return valve 24 at the outlet of the pump
Data Source
AI summary
Transfer pump for high-pressure petrol injection of the type comprising a piston (1) which delivers oil into a deformable element such as a bellows (8), the deformations of said bellows (8) in a cylindrical chamber (6) filled with fuel causing a pumping effect whereby said fuel is pumped towards a rail (40) supplying high-pressure injectors, wherein means are arranged for diverting some or all of the oil pumped by the piston (1) towards a chamber (15) without pressuring it so as to determine at will the useful stroke of said piston (1) and hence the quantity of fuel pumped at high pressure towards the rail (40).