Hand-Held Power Tool Control Unit Layout Beside the Fuel Tank

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Solution Overview

Problem

Existing hand-held power tools, such as angle grinders and chain saws, face challenges in optimizing the installation space and weight distribution of control devices, leading to inefficient use of available space and potential mechanical damage, as well as difficulties in accessing and protecting electrical components.

Innovation Solution

The control device is strategically arranged alongside the fuel tank, allowing for effective use of installation space, improved weight distribution, and enhanced accessibility by being housed in an open receptacle with secure fastening, while being vibration-decoupled from the internal combustion engine to minimize mechanical stress.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If the control device is arranged above the fuel tank and above the intake duct (conventional position), then the installation space is utilized in a traditional manner, but the available space is not used effectively and the center of gravity is unfavorable

Engineering Contradiction:
Improvecenter of gravity optimizationVSAvoidinstallation space utilization
Core Design Contradiction:
Ease of operationVSArea of stationary object

Solution Approach 1:

The control device is relocated from a vertical arrangement (above the fuel tank) to a lateral arrangement (beside the fuel tank). This spatial reconfiguration in a different dimension enables effective use of previously unused side spaces while optimizing the center of gravity position for improved handling characteristics

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Ease of operation

If the control device is exposed without a receptacle, then accessibility is maximized, but the control device is vulnerable to mechanical damage

Engineering Contradiction:
Improveaccessibility of control deviceVSAvoidprotection against mechanical damage
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The control device is nested within a receptacle that is open on the side facing the operator. This nested structure provides mechanical protection for the control device while maintaining easy accessibility through the open side, allowing the operator to reach the controls without removing any components

Inventive Principle:
Principle #7Nested doll (Nesting)

3Ease of manufacture

If connection lines are routed externally, then installation is simpler, but the connection lines are exposed to mechanical damage and interference

Engineering Contradiction:
Improverouting of connection linesVSAvoidprotection of connection lines
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The connection lines are routed through the fuel tank housing, utilizing the existing structural space. This nested routing approach protects the connection lines from mechanical damage and interference while maintaining a clean, organized installation without requiring additional external conduits

Inventive Principle:
Principle #7Nested doll (Nesting)

4Reliability

If the control device is fixed with multiple fastening points, then the fixing is more secure, but the installation requires more space and complexity

Engineering Contradiction:
Improvefixing security of control deviceVSAvoidnumber of fastening points
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The fixing system is segmented into two functional parts: vibration decoupling (achieved through the receptacle design that isolates the control device from engine vibrations) and positional securing (achieved through strategically placed fastening points). This segmentation allows secure mounting with minimal fastening points while maintaining reliability

Inventive Principle:
Principle #1Segmentation

Data Source

PatentEP3181856B1Manually operated working device having a control device
Publication Date: 2021.11.17 ANDREAS STIHL AG & CO KG
  • EP3181856B1 patent drawingFigure 1~3
  • EP3181856B1 patent drawingFigure 4~5
  • EP3181856B1 patent drawingFigure 6~7

AI summary

The invention relates to a hand-held power tool comprising a housing (2) in which an internal combustion engine (7) is arranged to drive a tool of the power tool. The power tool has a fuel tank (11) and a control unit (29) for controlling at least one electrical component of the power tool. The control unit (29) is an electronic control unit. The control unit (29) is connected to at least one electrical component of the power tool. The power tool has a top surface (47) which faces upwards when the power tool is placed in a normal storage position (42) on a flat, horizontal storage surface (41). An advantageous design of the power tool is achieved when the control unit (29) is arranged laterally next to the fuel tank (11) in the normal storage position (42).