High-Pressure Fuel Pump Cylinder Fixation With Radial Clearance
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
High-pressure fuel pumps face increased costs due to the need for specialized facilities for ring mash bonding and risk of plunger sticking due to radial displacement of the cylinder, which can lead to reduced fuel pressure and efficiency.
Innovation Solution
A high-pressure fuel pump design that uses a pump body with a pressing chamber and a cylinder inserted into a hole, where the cylinder is swaged or screwed into place, creating a clearance in the radial direction to prevent radial displacement and sticking.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If ring mash bonding is used to fix the cylinder to the pump body, then the cylinder is securely fixed, but specialized facilities are required and manufacturing costs increase
Solution Approach 1:
The invention extracts the cylinder from the pressing chamber region and positions it in a hole formed in the pump body away from the pressing chamber. This extraction eliminates the need for ring mash bonding facilities while maintaining secure fixation through the hole structure, thereby reducing manufacturing complexity without compromising fixation reliability
Solution Approach 2:
The invention introduces a hole in the pump body as an intermediary structure to fix the cylinder. This hole acts as a mediator that secures the cylinder without requiring direct contact bonding with the pressing chamber, thus eliminating the need for specialized bonding facilities while maintaining secure fixation
2Stress or pressure
If the cylinder is fixed near the pressing chamber to withstand high pressure, then pressure containment is improved, but thermal expansion causes radial displacement and plunger sticking
Solution Approach 1:
The invention extracts the cylinder from the pressing chamber region and relocates it to a hole formed in the pump body away from the pressing chamber. This relocation separates the cylinder from the high-temperature zone, preventing thermal expansion-induced radial displacement and plunger sticking, while the hole structure maintains secure fixation
Solution Approach 2:
The invention segments the pump structure by separating the cylinder positioning function from the pressing chamber function. The cylinder is positioned in a dedicated hole in the pump body rather than being directly attached to the pressing chamber, allowing independent optimization of pressure containment and thermal management
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 allows for a simple and effective fixation of the cylinder, reducing radial displacement and preventing plunger sticking, thereby maintaining high fuel pressure and efficiency even at elevated temperatures.
Implementation Method 1
The cylinder 6 is swaged to the hole 1a by pressing a convex portion 6b on an outside in a radial direction to fit into the hole 1a on an opposite side to the pressing chamber 11
Implementation Method 2
by screwing a formed screw thread into the hole
Implementation Method 3
The cylinder 6 is formed with a clearance 6c in the radial direction with respect to the hole 1a of the pump body all over a region from a bonding portion 6d to an upper end
Data Source
Figure 1
Figure 2
Figure 3
AI summary
Provided is a high-pressure fuel pump which can fix a cylinder to a pump body using a simple structure, and can reduce a displacement amount inward in a radial direction of the cylinder. A high-pressure fuel pump includes a pump body which is formed with a pressing chamber and a cylinder which is inserted in a hole formed in the pump body. The cylinder is swaged to the hole by pressing a convex portion on an outside in a radial direction to fit into the hole on an opposite side to the pressing chamber, by screwing a formed screw thread into the hole, or by being swaged with the opposite side to the pressing chamber. The cylinder is formed with a clearance in the radial direction with respect to the hole of the pump body all over a region from a bonding portion to an upper end.