Fuel Pump Jet Valve for Cold Start Pressure
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Solution Overview
Problem
The existing fuel supply systems for vehicles, particularly those with saddle-shaped fuel tanks, experience delays in increasing fuel pressure to the engine during cold starts, leading to degraded cold startability due to the additional second jet pump, which causes a loss in flow rate and prolongs the time for the engine to reach the required pressure.
Innovation Solution
A valve system for the vehicle fuel pump is introduced, featuring a jet pump control valve that manages the flow path between the fuel pump and the jet pump, opening when the engine starts and reaches a set pressure, and closing when the pressure drops below a second set pressure, utilizing a plunger and foldable leaf spring mechanism to control the flow and prevent fuel loss.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a second jet pump is added to charge the reservoir cup from the second fuel storage space, then the fuel supply capability is improved, but the flow rate loss increases and cold startability deteriorates
Solution Approach 1:
The jet pump control valve is configured to open the jet pump flow path in advance before engine start, allowing fuel to be pre-supplied to the jet pump. This preliminary action ensures that when the engine starts, the fuel pressure reaches the required level faster, improving cold startability while maintaining the fuel supply capability provided by the second jet pump
2Reliability
If the jet pump flow path remains open during engine operation, then the jet pump remains operable, but fuel flow rate is lost
Solution Approach 1:
The jet pump control valve dynamically adjusts the jet pump flow path based on engine operating conditions. During engine operation, the valve closes the jet pump flow path to prevent fuel flow rate loss. During engine start, the valve opens the flow path to ensure jet pump operability. This dynamic adjustment resolves the contradiction between maintaining reliability and preventing substance loss
3Reliability
If fuel is continuously supplied to the jet pump, then the jet pump can operate anytime, but the fuel pressure buildup time increases
Solution Approach 1:
The jet pump control valve implements periodic action by opening the jet pump flow path only during specific periods (engine start and low pressure conditions) and closing it during other periods (normal operation). This periodic control ensures the jet pump is available when needed while minimizing the duration of fuel supply that would otherwise extend pressure buildup time
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 solution significantly reduces the time for the engine to reach the necessary fuel pressure during cold starts, improving cold startability and ensuring the jet pump's operability by preventing fuel flow rate loss and maintaining the jet pump's functionality post-engine start.
Implementation Method 1
a foldable leaf spring, which is configured to be elastically deformed when a pressure of fuel discharged from the fuel pump to the engine is increased to reach a set pressure
Data Source
AI summary
A valve system of a vehicle fuel pump includes: a reservoir cup disposed within a fuel tank storing fuel in the reservoir cup; a fuel pump configured to pump fuel from the reservoir cup to the engine while supplying fuel to a jet pump through a first discharge port; a jet pump configured to charge the reservoir cup with fuel by drawing fuel from the fuel tank by using a pressure of fuel supplied by the fuel pump; and a jet pump control valve disposed on the first discharge port and configured to control a flow of fuel discharged from the fuel pump to the jet pump.