Fuel Pump Diaphragm Mass Addition for Pulsation Damping
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing fuel pumps with dual metal diaphragms for pressure pulsation reduction require multiple diaphragm designs to accommodate varying engine and vehicle types, increasing production costs due to the need for different diaphragm shapes and sizes to manage changing pressure pulsation frequencies.
Innovation Solution
A fuel pump design featuring a pair of metal diaphragms with a mass addition member, such as a resin film, attached to one diaphragm, allowing for different characteristic frequencies without altering the diaphragm shape or size, enabling effective pressure pulsation reduction across varying frequencies while maintaining cost efficiency by using the same diaphragm shape and size.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If two metal diaphragms with different uneven shapes in cross section are provided to achieve different characteristic frequencies, then the pressure pulsation reduction effect is improved across varying frequencies, but the product cost increases and manufacturing complexity increases
Solution Approach 1:
The patent changes the physical parameter of mass by attaching a mass addition member to one of the diaphragms. This modifies the characteristic frequency of that diaphragm without changing its shape or size, thereby achieving different characteristic frequencies between the two diaphragms while maintaining manufacturing simplicity and cost-effectiveness
Solution Approach 2:
The mass addition member acts as an intermediary element that is attached to one diaphragm to alter its dynamic properties. This intermediary component enables the diaphragm to have a different characteristic frequency without requiring complex shape modifications, thus resolving the contradiction between performance and manufacturing cost
2Reliability
If two metal diaphragms with different uneven shapes in cross section are provided to achieve different characteristic frequencies, then the pressure pulsation reduction effect is improved across varying frequencies, but the device complexity increases
Solution Approach 1:
Instead of changing the geometric shape of the diaphragms, the patent changes the mass parameter by adding a mass addition member. This simplifies the device design because the diaphragms can have the same shape while still achieving different characteristic frequencies through parameter modification
Solution Approach 2:
The same diaphragm shape can be used for both diaphragms, making the design universal and easier to manufacture. The mass addition member provides the differentiation needed for different characteristic frequencies without requiring different diaphragm geometries, thereby reducing device complexity
3Reliability
If various kinds of uneven metal diaphragms are prepared in accordance with engine type and vehicle type, then the pressure pulsation reduction effect is optimized for specific applications, but the product cost increases significantly
Solution Approach 1:
The patent creates a universal diaphragm design where the same diaphragm shape can be used across different engine and vehicle types. By attaching mass addition members of different weights or configurations, the characteristic frequency can be adjusted for different applications without needing to manufacture different diaphragm shapes, thereby significantly reducing product cost
Solution Approach 2:
The patent uses parameter changes (mass addition) rather than geometric changes to adapt the diaphragm to different applications. This allows a single diaphragm design to serve multiple purposes across different engine and vehicle types, reducing the need for multiple specialized diaphragm designs and lowering overall product cost
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
The solution effectively reduces pressure pulsation in fuel pumps by ensuring one diaphragm does not resonate when the pulsation frequency matches its characteristic frequency, maintaining pulsation reduction efficacy across changing engine speeds without increasing production costs.
Implementation Method 1
a mass addition member attached to an inside surface of at least one of the first and second diaphragms
Implementation Method 2
the diaphragm is elastically deformed by receiving the fuel pressure
Implementation Method 3
used as a damper mechanism for reducing a pressure pulsation of the fuel
Data Source
AI summary
A fuel pump includes a housing having therein a suction passage and a pressurization chamber into which fuel from the suction passage flows, a plunger held in the housing to be reciprocable so as to pressurize the fuel flowing into the pressurization chamber, and a diaphragm device located in a suction chamber that is provided in the suction passage. The diaphragm device includes a pair of first and second diaphragms that are arranged to define an inner space therebetween and air-tightly sealed at its entire peripheries. A mass addition member may be attached to an inside surface of at least one of the first and second diaphragms, so that the first and second diaphragms with the mass addition member have different characteristic frequencies. Accordingly, pressure pulsation of the fuel in the suction chamber can be effectively reduced by the pulsation damper.