High-Pressure Fuel Pump Piston Securing Mechanism

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

The existing high-pressure fuel pump designs face issues with securing the connection between the pump piston and the tappet, leading to potential instability and misalignment, which affects the pump's performance.

Innovation Solution

A secure connection is achieved by using a disc with a larger outer diameter than the pump piston, fastened to the piston with a securing element such as an elastic spring ring, which is snapped into a circumferential annular groove on the tappet, ensuring limited relative movement and reliable attachment.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a spring is used as a securing element to hold the disc in contact with the pump piston, then the connection is maintained under normal conditions, but the connection is not adequately secured under certain circumstances

Engineering Contradiction:
Improveconnection reliabilityVSAvoidsecuring strength
Core Design Contradiction:
ReliabilityVSStrength

Solution Approach 1:

The securing element is divided into multiple functional segments: a retaining ring portion for mechanical retention, a spring portion for maintaining contact force, and a bearing portion for load distribution. This segmentation allows each segment to perform its specific function optimally, ensuring both reliability and strength of the connection.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The securing element combines multiple material properties within a single component: elastic properties of the spring portion for continuous contact, rigid properties of the retaining ring for secure retention, and bearing properties of the bearing portion for load distribution. This composite approach ensures both reliable connection and adequate securing strength under all operating conditions.

Inventive Principle:
Principle #40Composite materials

2Device complexity

If the pump piston is directly connected to the tappet without additional securing elements, then the structure is simple, but the connection is unstable and misalignment occurs

Engineering Contradiction:
Improvestructure complexityVSAvoidconnection stability
Core Design Contradiction:
Device complexityVSStability of the object's composition

Solution Approach 1:

Multiple securing functions are merged into a single integrated securing element that combines retaining ring, spring, and bearing functions. This unified component maintains connection stability and prevents misalignment while adding minimal complexity compared to multiple separate securing components.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The securing element serves multiple functions simultaneously: it retains the disc on the pump piston, maintains continuous contact through spring force, distributes loads through the bearing portion, and prevents misalignment. This multi-functionality ensures connection stability without requiring multiple separate components.

Inventive Principle:
Principle #6Universality (Multi-functionality)

3Reliability

If a complex securing mechanism is used to ensure reliable connection, then the connection stability is improved, but the manufacturing and assembly process becomes more difficult

Engineering Contradiction:
Improveconnection reliabilityVSAvoidmanufacturing ease
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The securing element is designed as a segmented component with distinct functional zones (retaining ring, spring portion, bearing portion) that can be manufactured using standard processes and then assembled as a complete unit. This segmentation enables reliable connection while maintaining ease of manufacture through modular construction.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The securing element acts as an intermediary component between the disc and the pump piston, providing all necessary securing functions through a single mediating component. This eliminates the need for multiple complex securing mechanisms, thereby ensuring reliable connection while simplifying manufacturing and assembly.

Inventive Principle:
Principle #24Intermediary (Mediator)

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 provides a reliable and simple securing mechanism for the pump piston to the tappet, enhancing the pump's stability and ease of manufacturing, while allowing for a straightforward attachment process, thus improving the overall performance and assembly efficiency.

Implementation Method 1

a securing element (64), in particular an elastic spring ring, which is snapped into a circumferential annular groove (62) on the tappet

Methodology Applied
Scientific EffectElastic deformation: Elasticity

Implementation Method 2

with a spring being provided, by which the tappet is acted upon towards the drive shaft

Methodology Applied
Scientific EffectMechanical force: Mechanical Force

Data Source

PatentEP2271838B1Pump, particularly a high-pressure fuel pump
Publication Date: 2011.06.08 ROBERT BOSCH GMBH
  • EP2271838B1 patent drawingFigure 1
  • EP2271838B1 patent drawingFigure 2

AI summary

The invention relates to a pump, comprising at least one pump element (18), which has a pump piston (20) driven in a lifting motion at least indirectly by a drive shaft (14). The pump piston (20) is guided in a cylinder bore (22) of a housing part (24) of the pump, wherein the housing part (24) has a cylindrical section (44) surrounding the cylinder bore (22). A cup-shaped tappet (50) is disposed between the pump piston (20) and the drive shaft (14) and has base (52) facing the drive shaft (14), and a jacket (54) connected thereto, wherein the jacket (54) of the tappet (50) is guided on the cylindrical section (44) of the housing part (24) in a displaceable manner. A spring (58) is provided, by means of which the tappet (50) is pressurized toward the drive shaft (14). The pump piston (20) abuts the base (52) of the tappet (50) with the front (21) thereof facing the drive shaft (14). A disk (60) is mounted on the pump piston (20) in the end region thereof facing the base (52) of the tappet (50), said disk having a greater outside diameter than the pump piston (20). The pump piston (20) comprising the disk (60) is secured in the tappet (50) in the direction of the longitudinal axis (23) of the pump piston (20) by means of a safety element (64) engaging in the disk (60).