Log Saw Grinding Wheels Inversion for Blade Shape

Solution Overview

Problem

Existing saw machines for cutting logs of web material, such as tissue paper, face issues with non-uniform grinding of disc-shaped cutting blades, leading to reduced blade life and compromised cutting quality due to suboptimal grinding methods.

Innovation Solution

The saw machine incorporates two grinding wheels arranged to rotate with their velocity directed towards the inside of the cutting edge, supported by friction with the blade, ensuring symmetrical contact areas and optimal grinding conditions, preventing chip formation and maintaining blade shape.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If conventional grinding methods are used with grinding wheels pressed against the cutting edge, then the blade can be ground, but non-uniform consumption occurs and the cutting edge becomes polygonal

Engineering Contradiction:

Improvegrinding uniformityVSAvoidcutting edge roundness

Core Design Contradiction:

Manufacturing precisionVSShape

Solution Approach 1:

Instead of pressing grinding wheels against the cutting edge from the outside, the patent inverts the approach by having the grinding wheel periphery contact the cutting edge from the inside, with the grinding wheel rotating in the opposite direction to the blade rotation. This inversion eliminates the polygonal deformation caused by conventional external pressing methods.

Inventive Principle:

Principle #13The other way round (Inversion)

Solution Approach 2:

The grinding wheel is driven into rotation by friction contact with the rotating disc blade itself, rather than by an external motor. The blade's own rotational motion serves to drive the grinding wheel, creating a self-service grinding system that ensures uniform contact and eliminates polygonal deformation.

Inventive Principle:

Principle #25Self-service

2Ease of manufacture

If grinding wheels are pressed against the cutting edge to grind the blade, then grinding can be performed, but the blade deformation occurs and useful life decreases

Engineering Contradiction:

Improvegrinding operationVSAvoidblade useful life

Core Design Contradiction:

Ease of manufactureVSDuration of action of moving object

Solution Approach 1:

The grinding wheel is driven into rotation by friction contact with the rotating disc blade itself, rather than by an external motor. The blade's own rotational motion serves to drive the grinding wheel, creating a self-service grinding system that ensures uniform contact and eliminates polygonal deformation.

Inventive Principle:

Principle #25Self-service

Solution Approach 2:

Instead of pressing grinding wheels against the cutting edge from the outside, the patent inverts the approach by having the grinding wheel periphery contact the cutting edge from the inside, with the grinding wheel rotating in the opposite direction to the blade rotation. This inversion eliminates the polygonal deformation caused by conventional external pressing methods.

Inventive Principle:

Principle #13The other way round (Inversion)

3Productivity

If disc-shaped cutting blades are used for cutting logs, then cutting can be performed, but the blades wear and require frequent grinding and replacement

Engineering Contradiction:

Improvecutting operationVSAvoidblade service life

Core Design Contradiction:

ProductivityVSDuration of action of moving object

Solution Approach 1:

The grinding wheel is driven into rotation by friction contact with the rotating disc blade itself, rather than by an external motor. The blade's own rotational motion serves to drive the grinding wheel, creating a self-service grinding system that ensures uniform contact and eliminates polygonal deformation.

Inventive Principle:

Principle #25Self-service

Solution Approach 2:

Instead of pressing grinding wheels against the cutting edge from the outside, the patent inverts the approach by having the grinding wheel periphery contact the cutting edge from the inside, with the grinding wheel rotating in the opposite direction to the blade rotation. This inversion eliminates the polygonal deformation caused by conventional external pressing methods.

Inventive Principle:

Principle #13The other way round (Inversion)

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 provides regular grinding, enhances cutting quality, and extends the useful life of the disc-shaped cutting blade by preventing deformation and improving cutting efficiency.

Implementation Method 1

The grinding wheels are supported idle and driven into rotation by friction between the active surface of the grinding wheel and the blade surface to be ground

Methodology Applied

Scientific EffectFriction: Friction

Data Source

PatentEP3448644B1Log saw machine with grinding wheels and grinding method

Publication Date: 2020.02.12 FABIO PERINI SPA

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AI summary

The saw machine (1) comprises a feeding path (PA) for the logs (L) to be cut and a cutting head (5) arranged along the feeding path (PA). The cutting head comprises a disc-shaped cutting blade (9) rotating around a rotation axis (B-B) and provided with a cyclic movement for cutting the logs (L). The cutting head 5 also comprises two grinding wheels (32, 34), which are arranged and configured to grind two sides of a cutting edge (9B) of the disc-shaped cutting blade (9), and each of which rotates around its rotation axis (C-C; D-D). The grinding wheels (32, 34) are so arranged, with respect to the disc-shaped cutting blade (9), that, in a contact area (Z32, Z34) between each grinding wheel (32; 34) and 10 the disc-shaped cutting blade (9), the grinding wheel (32; 34) has a velocity directed towards the inside of the cutting edge.