Abrasive Disc Hole Pattern for Dust Extraction and Stability

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Solution Overview

Problem

Existing abrasive articles face challenges in maximizing material removal during surface machining while preventing clogging and maintaining mechanical stability, as high hole densities often lead to tearing and reduced service life due to increased structural instability.

Innovation Solution

A coated grinding wheel with a hole pattern featuring a decreasing hole density from the interior to the exterior region, incorporating elongated holes arranged in a spiral line pattern, which enhances suction efficiency and mechanical stability by reducing the nozzle effect and distributing forces more evenly.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If high hole density is used to increase dust extraction efficiency, then material removal capability is improved, but mechanical stability deteriorates leading to tearing and reduced service life

Engineering Contradiction:
Improvematerial removal capabilityVSAvoidmechanical stability
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The patent applies local quality by varying the hole density across different regions of the abrasive article. The inner region (first region) has a higher hole density to enhance dust extraction where material removal is most intensive, while the outer region (second region) has a lower hole density to maintain mechanical stability and prevent tearing at the edges. This spatial variation in hole density optimizes both productivity and reliability locally across the article surface.

Inventive Principle:
Principle #3Local quality

2Productivity

If high hole density is used to improve dust extraction, then clogging prevention is improved, but structural instability increases

Engineering Contradiction:
Improvedust extraction efficiencyVSAvoidstructural stability
Core Design Contradiction:
ProductivityVSStability of the object's composition

Solution Approach 1:

The patent implements local quality by creating region-specific hole densities that address different functional requirements. The first region with higher hole density efficiently extracts dust and prevents clogging during intensive grinding operations, while the second region with lower hole density maintains the structural integrity and compositional stability of the overall abrasive article, preventing tears and extending service life.

Inventive Principle:
Principle #3Local quality

3Ease of manufacture

If uniform hole distribution is used to simplify manufacturing, then ease of manufacture is improved, but dust extraction efficiency deteriorates due to nozzle effect

Engineering Contradiction:
Improvehole pattern manufacturingVSAvoiddust extraction efficiency
Core Design Contradiction:
Ease of manufactureVSProductivity

Solution Approach 1:

The patent applies local quality by differentiating hole density between the inner and outer regions. This non-uniform distribution prevents the nozzle effect that occurs with uniform hole patterns, where adjacent holes create competing airflows that reduce extraction efficiency. The varied density pattern optimizes airflow dynamics and dust extraction while remaining manufacturable through standard punching or drilling processes.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The patent employs asymmetry by deliberately creating an asymmetric hole distribution pattern across the abrasive article surface. The inner region contains more holes per unit area than the outer region, breaking the symmetry of uniform distributions. This asymmetric arrangement optimizes the airflow paths and prevents the nozzle effect, thereby enhancing dust extraction efficiency without significantly complicating the manufacturing process.

Inventive Principle:
Principle #4Asymmetry

4Productivity

If elongated holes are used to improve dust extraction, then suction efficiency is improved, but manufacturing complexity increases

Engineering Contradiction:
Improvesuction efficiencyVSAvoidhole pattern complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The patent applies the curvature principle by using elongated holes instead of circular holes in the abrasive article. The elongated shape creates more favorable airflow paths that enhance suction efficiency and dust extraction capability. While slightly more complex than circular holes, the elongated shape can still be manufactured using standard punching or drilling equipment, balancing performance improvement with manufacturing feasibility.

Inventive Principle:
Principle #14Spheroidality (Curvature)

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 improves dust extraction efficiency, reduces clogging, and enhances the mechanical stability of the abrasive article, allowing for increased material removal while extending the service life by optimizing hole distribution and flow dynamics.

Implementation Method 1

a plurality of holes (12b) arranged in a hole pattern (14b), with a hole density decreasing from an inner region (18b) of the hole pattern (14b) to an outer region (20b) of the hole pattern (14b), for extracting grinding dust from a working surface (202) during a grinding process on the working surface (202)

Methodology Applied
Scientific EffectSuction: Suction

Data Source

PatentEP3681675B1Abrasive article
Publication Date: 2024.10.09 ROBERT BOSCH GMBH
  • EP3681675B1 patent drawingFigure 1
  • EP3681675B1 patent drawingFigure 2
  • EP3681675B1 patent drawingFigure 3

AI summary

The invention relates to an abrasive article (10a,10b,10c,10d), in particular a coated abrasive disc, comprising a plurality of holes (12a,12b,12c,12d) which are arranged in a hole pattern (14a,14b,14c,14d), wherein the density of holes decreases from an inner region (18a,18b,18c,18d) of the hole pattern (14a,14b,14c,14d) to an outer region (20a,20b,20c,20d) of the hole pattern (14a,14b,14c,14d). The invention is characterized in that at least one hole (12a,12b,12c,12d) in the hole pattern (14a,14b,14c,14d) is designed as an elongated hole (38a,38b,38c,38d).