Impact Power Tool Weight and Elastic Element Vibration Absorption

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Solution Overview

Problem

Existing impact power tools face challenges in balancing the need for a rubber ring to cushion impact forces while maintaining positioning accuracy, as a soft rubber ring effectively absorbs rebound but a hard rubber ring is required for precise positioning, making it difficult to satisfy both functional requirements simultaneously.

Innovation Solution

The impact power tool incorporates a hammer actuating member, a weight, an elastic element, and a control member, where the reaction force from the workpiece is transmitted to a weight via a hard metal intervening member, allowing for efficient absorption of the reaction force through elastic deformation, and a control member prevents unnecessary forward force application, enabling precise positioning without adverse elastic forces.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If a soft rubber ring is used to cushion impact force, then the impact force absorption is improved, but the positioning accuracy deteriorates

Engineering Contradiction:
Improveimpact forceVSAvoidpositioning accuracy
Core Design Contradiction:
Object-affected harmful factorsVSMeasurement precision

Solution Approach 1:

The invention divides the impact absorption function into two separate components: a hard metal plate that transmits impact forces and a soft rubber ring that absorbs rebound forces. This segmentation allows each component to be optimized for its specific function without compromise - the metal plate maintains positioning accuracy while the rubber ring provides impact cushioning.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The hard metal plate acts as an intermediary element between the hammer actuating member and the rubber ring. It transmits the reaction force from the workpiece to the rubber ring, enabling the soft rubber to effectively cushion impact forces while the metal plate maintains the structural rigidity needed for accurate positioning.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Measurement precision

If a hard rubber ring is used to improve positioning accuracy, then the positioning accuracy is improved, but the impact force absorption deteriorates

Engineering Contradiction:
Improvepositioning accuracyVSAvoidimpact force
Core Design Contradiction:
Measurement precisionVSObject-affected harmful factors

Solution Approach 1:

The invention uses a composite structure combining hard metal and soft rubber materials. The hard metal plate provides the rigidity needed for accurate positioning, while the soft rubber ring provides elastic deformation capability for impact absorption. This composite approach allows both contradictory requirements to be satisfied simultaneously through material differentiation.

Inventive Principle:
Principle #40Composite materials

3Object-affected harmful factors

If the reaction force is transmitted to the weight through elastic deformation, then the vibration is reduced, but the force transmission efficiency deteriorates

Engineering Contradiction:
ImprovevibrationVSAvoidforce transmission efficiency
Core Design Contradiction:
Object-affected harmful factorsVSForce

Solution Approach 1:

The control member pre-compresses the elastic element before the hammer actuating member rebounds. This preliminary action ensures that when the reaction force occurs, the elastic element is already in a state ready to absorb the force efficiently, maximizing both vibration reduction and force transmission. The control member actively prepares the system in advance to optimize the interaction between force transmission and vibration damping.

Inventive Principle:
Principle #10Preliminary action

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 configuration allows for approximately 100% transmission of the reaction force, reducing vibration and enabling efficient absorption of the impact force, while maintaining accurate positioning of the tool, thus addressing the dual requirements of impact force reduction and positioning precision.

Implementation Method 1

the elastic element is elastically deformed and absorbs the reaction force

Methodology Applied
Scientific EffectElastic deformation: Elasticity

Data Source

PatentEP1754575B1Impact power tool
Publication Date: 2011.05.25 MAKITA CORP
  • EP1754575B1 patent drawingFigure 1
  • EP1754575B1 patent drawingFigure 2
  • EP1754575B1 patent drawingFigure 3

AI summary

It is an object of the invention to provide an improved technique for lessening an impact force caused by rebound of a tool bit after the striking movement of the tool bit Representative impact power tool (101) includes a tool body (103), a hammer actuating member (119, 145), a driving mechanism (113, 115), a weight (163) and an elastic element (165). A reaction force that the hammer actuating member receives from the workpiece when performing a hammering operation is transmitted from the hammer actuating member to the weight (163) and then, the weight (163) is caused to move rearward to push the elastic element (165). As a result, the reaction force can be absorbed by the elastic element (165). The elastic force of the elastic element (165) is prevented from acting upon the weight (163) forward beyond the reaction force transmitting position.