Cutting Tool Holder With Internal Weight for Radial Vibration Damping
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Solution Overview
Problem
Cutting tools with low rigidity in the stem generate radial vibrations, leading to reduced machining accuracy when the protrusion amount of the cutting edge exceeds the stem diameter, particularly when machining metal workpieces.
Innovation Solution
A holder design incorporating a weight with a different natural frequency, an elastic member, and a lid press-fitted into a recessed portion with varying surface roughness to absorb radial vibrations, ensuring firm fixation and effective vibration reduction.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the protrusion amount of the cutting edge is increased to improve machining capability, then the cutting performance is improved, but radial vibration is easily generated due to low stem rigidity
Solution Approach 1:
The patent applies vibration damping by introducing a weight with different natural frequency into the stem cavity. The weight vibrates at a different frequency than the stem, creating destructive interference that reduces radial vibrations. This allows the cutting edge to protrude further without generating harmful vibrations, thus improving cutting performance while maintaining machining accuracy.
Solution Approach 2:
The patent creates a composite structure by combining the steel stem with a weight material having different damping characteristics. This composite system leverages the high strength of steel for structural support while the weight material provides superior vibration damping, enabling the stem to handle larger cutting edge protrusions without excessive vibration.
2Reliability
If a weight is inserted into the stem cavity to reduce vibration, then vibration damping is improved, but the weight may move or become loose during operation
Solution Approach 1:
The patent applies preliminary action by providing a fixing member that secures the weight to the stem before operation begins. The fixing member includes a pressing portion that applies predetermined force to press the weight against the cavity wall, preventing movement or loosening during machining operations while maintaining the vibration damping effect.
3Reliability
If the stem rigidity is increased to reduce vibration, then machining accuracy is improved, but the weight cannot be accommodated in the stem
Solution Approach 1:
The patent applies local quality by creating a recessed portion with greater radial depth at specific locations along the stem where vibration damping is most needed. This localized cavity design provides sufficient volume to accommodate the weight while maintaining the overall stem rigidity, as the reinforcement is concentrated where it provides maximum benefit rather than requiring a complete redesign of the entire stem structure.
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
The holder effectively reduces radial vibrations, enhancing machining accuracy and stability by integrating the weight and elastic member to absorb and dampen vibrations, thereby improving the cutting tool's performance.
Implementation Method 1
an elastic member (14) having a ring shape in contact with an inner peripheral surface of the recessed portion (11c)
Implementation Method 2
a weight (13) having a natural frequency different from that of the stem and vibrating the stem and the weight at different frequencies
Data Source
AI summary
The holder includes a body having a rod shape extending from a first end surface to a second end surface and including a large-diameter portion which is a recess extending from the first end surface, a weight located in the large-diameter portion, a ring-shaped first elastic member, and a lid press-fitted into the large-diameter portion from the side of the first end surface. The inner peripheral surface of the large-diameter portion includes a first region located on the side of the first end surface and a second region located closer to the second end surface than the first region. The first elastic member comes into contact with the inner peripheral surface of the large-diameter portion in the second region to fix the weight to the inner peripheral surface. The surface roughness of the second region is greater than the surface roughness of the first region.