Fuel Pump Relief Valve Venturi Nozzle Vapor Bubble Stability
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing overflow valves in fuel injection systems suffer from unstable and weak vapor bubbles, leading to inadequate hydraulic damping and pressure fluctuations, which affect the precision of regulating inlet pressure and quantity to the high-pressure pump.
Innovation Solution
The overflow valve features a Venturi nozzle with a tapering, smallest, and expanding cross-section design, along with a circumferential groove and control bores, creating negative pressure to enhance fuel suction and mobility, and a cup-shaped recess to stabilize vapor formation, improving hydraulic damping and pressure control.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a throttle is used to connect the spring chamber to the return line, then fuel can be supplied to the spring chamber, but the vapor bubble becomes unstable and weak, leading to inadequate hydraulic damping
Solution Approach 1:
The radial bore is divided into three distinct sections (first section with tapering cross-section, second section with smallest cross-section, third section with expanding cross-section), each serving a specific function in generating and stabilizing the vapor bubble. This segmentation allows optimized control of fuel flow and pressure distribution to maintain stable vapor bubble formation.
Solution Approach 2:
The patent changes the physical parameters of the bore by creating a Venturi nozzle structure with varying cross-sections. The tapering, smallest, and expanding sections create specific pressure and velocity distributions that stabilize the vapor bubble. The circumferential groove further modifies parameters by controlling fuel emergence and increasing flow speed, thereby stabilizing the vapor bubble composition.
2Stress or pressure
If fuel flows quickly through the throttle into the spring chamber, then pressure build-up is reduced, but a negative pressure forms causing vapor bubble formation that is unstable and weak
Solution Approach 1:
The dynamic structure of the Venturi nozzle with its varying cross-section creates optimal conditions for vapor bubble formation and stabilization. The first section's tapering, second section's smallest area, and third section's expanding area work together to dynamically control fuel flow velocity and pressure, maintaining stable vapor bubble composition while achieving precise pressure control.
Solution Approach 2:
The patent adds a circumferential groove dimension to the radial bore structure. This groove frees the outlet area of the third section, allowing fuel to emerge more easily and increasing flow speed. This dimensional addition stabilizes the vapor bubble by optimizing the multi-dimensional flow patterns within the spring chamber.
3Stability of the object's composition
If the outlet area of the third section is blocked, then the vapor bubble can be maintained, but the flow through the nozzle is reduced, decreasing the negative pressure and suction capacity
Solution Approach 1:
The circumferential groove adds a dimensional element that frees the outlet area of the third section without compromising vapor bubble stability. This groove allows fuel to emerge more easily from the nozzle, increasing flow speed and maintaining negative pressure while the vapor bubble remains stable due to the optimized flow patterns created by the groove's geometry.
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 stabilizes the vapor bubble, enhances hydraulic damping, and improves the precision of regulating inlet pressure and quantity to the high-pressure pump, ensuring consistent performance under varying operating conditions.
Implementation Method 1
The fuel flowing through the Venturi nozzle creates a negative pressure in the second section of the nozzle, with the negative pressure sucking fuel out of the spring chamber via the channel
Implementation Method 2
the negative pressure generated in the spring chamber promotes the formation of a vapor volume
Data Source
Figure 1
Figure 1a~2
AI summary
The invention relates to a bypass valve (10) for regulating a fuel flow rate in a low-pressure circuit of a fuel injection system and to a high-pressure pump (100) with such a bypass valve (10). The bypass valve (10) has a valve housing (12) and a valve piston (14) that is slidable in the valve housing (12), wherein a spring chamber (15) is formed between the valve piston (14) and the valve housing (12). A valve spring (16) is arranged in the spring chamber (15), by means of which the valve piston (14) is supported against the valve housing. At least one control bore (17) is formed in the valve housing (12), which is at least largely closed by the valve piston (14) when the valve spring (16) is unloaded.The valve piston (14) has a radial bore (18) in the form of a Venturi nozzle (19), comprising a first section (21) with a tapered cross-section, a second section (22) with a smallest cross-section and a third section (23) with an expanding cross-section, wherein the second section (22) is hydraulically connected to the spring chamber (15) via a channel (24).