Hedge Trimmer Blade Hardness Gradient for Wear Resistance
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Solution Overview
Problem
Current hedge trimmers experience reduced cutting efficiency due to the wear and blunting of cutting blades, requiring frequent sharpening to maintain sharpness.
Innovation Solution
The hedge trimmer design features cutting blades with a base body and cutting portions that include a first section with high surface hardness (750HV1-800HV1) for improved abrasion resistance and a second section with lower surface hardness (310HV1-360HV1), allowing the cutting edges to remain sharp for longer periods.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If the cutting blade is made with uniform high hardness material, then abrasion resistance is improved, but toughness and resistance to chipping deteriorate
Solution Approach 1:
The cutting blade employs different material compositions in different zones: the cutting edge portion uses a high-hardness material (HV750-800) for abrasion resistance, while the base portion uses a tougher material (HV310-360) for chipping resistance. This local differentiation of material properties resolves the contradiction between hardness and toughness.
Solution Approach 2:
The cutting blade is constructed as a composite structure with at least two different materials: a first material for the cutting edge portion and a second material for the base portion. This composite approach allows each zone to have optimized properties for its specific function, achieving both abrasion resistance and chipping resistance.
2Duration of action of stationary object
If the cutting blade is made with high hardness material, then service life is extended, but manufacturing complexity increases
Solution Approach 1:
The cutting blade is divided into distinct segments (cutting edge portion and base portion) that can be manufactured separately using different materials and processes, then assembled together. This segmentation simplifies manufacturing by allowing each part to be optimized independently rather than requiring complex processing of a uniform high-hardness material throughout.
Solution Approach 2:
By using composite materials with different properties in different zones, the manufacturing process can be simplified through modular construction. The high-hardness cutting edge can be manufactured or attached as a separate component, reducing the overall manufacturing complexity compared to processing a uniformly hard material.
Data Source
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AI summary
A hedge trimmer (100) that includes cutting portions (12) spaced from each other in a direction of the longitudinal axis (101). A base body (11) is formed in each cutting blade (10) with several coupling holes (111) for coupling the cutting blades (10) with a movable guiding bar (80). The coupling holes (111) go through the base body (11) in a direction of a vertical axis (103) which is substantially perpendicular to the longitudinal axis (101) and the lateral axis (102). Each cutting portion (12) includes a bottom surface (13) and a cutting surface (14). The cutting surface (14) is intersected obliquely with the bottom surface (13). The bottom surface (13) and the cutting surface (14) form a cutting edge (15). In the direction of the vertical axis (103), the cutting edge (15) includes a first section (151) close to the bottom surface (13) and a second section (152) far from the bottom surface (13), and the first section (151) has greater abrasive resistance than the second section (152). The cutting blades (10) of the hedge trimmer (100) have longer service life.