Hydraulic Piston Assembly Material Split for Fastener Tool Weight Reduction

Solution Overview

Problem

Existing fastener installation tools require high strength and toughness materials for hydraulic piston assemblies due to high pressures and mechanical shocks, leading to unnecessary material usage and increased weight, cost, and machining complexity.

Innovation Solution

Forming the elongate draw part and hollow piston part of the hydraulic piston assembly from different materials, where the hollow piston part is made from a low density material like aluminum and the elongate draw part from high strength steel, allowing for optimization of each part separately and reducing the need for high strength steel throughout the assembly.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the entire hydraulic piston assembly is formed from high strength steel, then the tool can withstand high pressures and mechanical shocks, but the tool weight increases and machining complexity increases

Engineering Contradiction:

Improvewithstand high pressures and mechanical shocksVSAvoidtool weight

Core Design Contradiction:

ReliabilityVSWeight of moving object

Solution Approach 1:

The patent applies local quality by making different parts of the hydraulic piston assembly from different materials with different properties. Specifically, the draw part is made from high strength steel to withstand high tensile loads during rivet installation, while the piston body is made from aluminum alloy to reduce weight. This localized material selection optimizes the overall tool by providing high strength only where needed rather than throughout the entire assembly.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The patent employs composite materials by combining high strength steel and aluminum alloy in a single hydraulic piston assembly. The draw part uses high strength steel for its superior tensile strength and toughness, while the piston body uses aluminum alloy for its low density and weight reduction. This composite approach allows the tool to achieve both high reliability under load and reduced overall weight.

Inventive Principle:

Principle #40Composite materials

2Reliability

If the entire hydraulic piston assembly is formed from high strength steel, then the tool can withstand high pressures and mechanical shocks, but machining difficulty increases

Engineering Contradiction:

Improvewithstand high pressures and mechanical shocksVSAvoidmachining difficulty

Core Design Contradiction:

ReliabilityVSEase of manufacture

Solution Approach 1:

The patent applies local quality by making different parts of the hydraulic piston assembly from different materials with different properties. Specifically, the draw part is made from high strength steel to withstand high tensile loads during rivet installation, while the piston body is made from aluminum alloy to reduce weight. This localized material selection optimizes the overall tool by providing high strength only where needed rather than throughout the entire assembly.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The patent employs composite materials by combining high strength steel and aluminum alloy in a single hydraulic piston assembly. The draw part uses high strength steel for its superior tensile strength and toughness, while the piston body uses aluminum alloy for its low density and weight reduction. This composite approach allows the tool to achieve both high reliability under load and reduced overall weight.

Inventive Principle:

Principle #40Composite materials

3Strength

If high strength steel is used throughout the assembly, then structural integrity is maintained under high loads, but material cost increases

Engineering Contradiction:

Improvestructural integrity under high loadsVSAvoidamount of high strength steel

Core Design Contradiction:

StrengthVSQuantity of substance

Solution Approach 1:

The patent applies local quality by making different parts of the hydraulic piston assembly from different materials with different properties. Specifically, the draw part is made from high strength steel to withstand high tensile loads during rivet installation, while the piston body is made from aluminum alloy to reduce weight. This localized material selection optimizes the overall tool by providing high strength only where needed rather than throughout the entire assembly.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The patent employs composite materials by combining high strength steel and aluminum alloy in a single hydraulic piston assembly. The draw part uses high strength steel for its superior tensile strength and toughness, while the piston body uses aluminum alloy for its low density and weight reduction. This composite approach allows the tool to achieve both high reliability under load and reduced overall weight.

Inventive Principle:

Principle #40Composite materials

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 approach minimizes the use of high density, high strength materials, reduces tool weight and machining difficulties, and results in a lighter, more durable tool with improved usability and durability.

Implementation Method 1

a hydraulic piston assembly located in the hydraulic cylinder for use in drawing back the stem of a fastener

Methodology Applied

Scientific EffectHydraulic pressure: Hydraulic Press

Implementation Method 2

the hollow piston part provides at least part of a hydraulic fluid contacting piston surface of the hydraulic piston assembly

Methodology Applied

Scientific EffectHydraulic force transmission: Pascal's Law

Data Source

PatentUS9492862B2Fastener installation tool

Publication Date: 2016.11.15 AVDEL UK LTD

AI summary

A fastener installation tool for installing a fastener by gripping and drawing back a stem of the fastener comprises a hydraulic cylinder, and a hydraulic piston assembly located in the hydraulic cylinder for use in drawing back the stem of a fastener. The hydraulic piston assembly comprises an elongate draw part and a separate hollow piston part mounted on the elongate draw part such that the elongate draw part extends at least partly through the hollow piston part. The elongate draw part and the hollow piston part are formed from different materials.