Laminated Plyboard Drum Shell with Phenol-Resin Core
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional drum manufacturing techniques face challenges in reducing vibration energy loss due to internal friction while maintaining high rigidity and affordability, particularly with the use of high-specific-gravity wood materials, which are expensive and difficult to obtain.
Innovation Solution
A laminated plyboard structure is employed with a phenol-resin impregnated layer sandwiched between two layers of common natural wood veneers, offering higher rigidity and reduced energy loss, and using a three-layer configuration where the phenol-resin layer has a specific gravity of 1.0 to 2.0, allowing for easier manufacturing and cost-effectiveness.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If an internal veneer having low specific gravity is used, then the cost is reduced and ease of manufacture is improved, but the loss of vibration energy due to internal friction increases and sound volume decreases
Solution Approach 1:
The patent applies local quality by assigning different specific gravity characteristics to different layers of the plyboard. The internal veneer has low specific gravity (0.3-0.6) for ease of manufacture and cost reduction, while the outer veneers have high specific gravity (0.7-1.2) to provide structural support and reduce vibration energy loss. This spatial differentiation of material properties resolves the contradiction between manufacturing ease and energy loss.
Solution Approach 2:
The patent uses composite materials by combining veneers with different specific gravity values in a laminated structure. The composite plyboard consists of multiple layers with varying density characteristics, where low-specific-gravity internal veneers are sandwiched between high-specific-gravity outer veneers. This composite approach allows simultaneous achievement of cost reduction and vibration energy preservation.
2Loss of energy
If an internal veneer having high specific gravity is used, then the loss of vibration energy due to internal friction is reduced and sound volume increases, but the cost increases and ease of manufacture decreases
Solution Approach 1:
The patent applies local quality by strategically placing high-specific-gravity veneers (0.7-1.2) only in the outer layers where structural support is needed, while using low-specific-gravity veneers (0.3-0.6) for the internal layer to minimize cost and manufacturing difficulty. This localized assignment of material properties resolves the contradiction between energy loss reduction and manufacturing ease.
Solution Approach 2:
The patent employs composite materials by creating a laminated structure that combines veneers of different specific gravity values. The composite plyboard integrates high-specific-gravity outer veneers for structural integrity and low-specific-gravity internal veneers for cost-effectiveness, thereby resolving the contradiction between reducing vibration energy loss and maintaining ease of manufacture.
3Strength
If all veneers are made of high specific gravity wood, then high rigidity is achieved and sound quality improves, but the cost becomes excessively high and material availability decreases
Solution Approach 1:
The patent applies local quality by assigning high-specific-gravity wood (0.7-1.2) specifically to the outer veneers where rigidity and structural strength are required, while using low-specific-gravity wood (0.3-0.6) for the internal veneer where cost reduction is prioritized. This spatial differentiation resolves the contradiction between achieving high rigidity and controlling manufacturing cost.
Solution Approach 2:
The patent uses composite materials by constructing a laminated plyboard with veneers of different specific gravity values. The composite structure combines high-specific-gravity outer veneers for rigidity with low-specific-gravity internal veneers for cost reduction, thereby resolving the contradiction between strength and manufacturing cost.
4Reliability
If a polygonal shell structure is used, then sound characteristics are improved, but the drum head stretching structure becomes complex and typical head frames cannot be used
Solution Approach 1:
The patent applies segmentation by dividing the shell into a cylindrical body portion and a separate flange portion. The cylindrical body provides optimized sound characteristics, while the flange is designed as a separate component that facilitates standard drum head mounting. This segmentation resolves the contradiction between sound quality and structural complexity.
Solution Approach 2:
The patent applies universality by designing the flange portion with a structure that accommodates standard drum head mounting hardware. The flange serves multiple functions: structural support for the drum head, mounting interface for tension rods, and acoustic reinforcement. This multi-functionality resolves the contradiction between optimized sound characteristics and structural complexity.
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 achieves a sound with minimal distortion and increased volume, providing high rigidity and favorable acoustic characteristics at a lower cost by reducing internal friction and utilizing more readily available and affordable wood materials.
Implementation Method 1
these are then pressed so as to harden the resin and cause the plates and the paper to bond together
Implementation Method 2
a phenol-resin impregnated layer sandwiched between two layers of common natural wood veneers
Data Source
Figure 1A~1B
Figure 2A~2B
Figure 3A~3C
AI summary
A laminated plyboard for a musical instrument which reduces a loss of vibration energy due to internal friction while securing high rigidity with inexpensive cost. A laminated plyboard 20 comprises a first layer portion S1 including layers 24 and 25, a second layer portion S2 including layers 26 and 27, and an impregnated layer 21 impregnated with phenol and sandwiched between the first layer portion S1 and the second layer portion S2. A rigidity coefficient of the impregnated layer 21 is higher than rigidity coefficients of the layers 24 to 27 that configure the first layer portion S1 and the second layer portion S2.