Balancer Device for Parallel Twin Cylinder Engine Vibration
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Solution Overview
Problem
In parallel twin cylinder internal combustion engines, setting the balancer device becomes restricted when crank phase angles are set at irregular intervals, such as 270 degrees, leading to complex vibrations and reduced degree of freedom in layout due to increased space occupation in the crankcase.
Innovation Solution
A balancer device configuration that resolves the primary vibration into inertial force and couple components, using inertial force balancers and couple balancers arranged symmetrically and coaxially to face these components, allowing flexible mass and layout settings, and positioning these balancers outside the crankcase to reduce space occupation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If crank phase angles are set at irregular intervals (e.g., 270 degrees) to characterize output characteristics, then torque variation and output characteristics are improved, but primary vibration becomes complex and space occupation in crankcase increases
Solution Approach 1:
The patent segments the balancer device into two distinct functional components: an inertial force balancer and a couple balancer. This segmentation allows each component to address specific vibration types independently, enabling effective vibration reduction with more compact individual components that reduce overall space occupation in the crankcase.
Solution Approach 2:
The patent positions the balancers in three-dimensional space outside the crankcase housing, utilizing vertical and lateral dimensions rather than only horizontal plane arrangement. This spatial reconfiguration reduces the footprint within the crankcase while maintaining vibration reduction effectiveness.
2Power
If crank phase angles are set at irregular intervals, then output characteristics are improved, but the degree of freedom in layout is reduced due to complex vibration patterns
Solution Approach 1:
By dividing the vibration control function into separate inertial force and couple balancers, the patent provides independent adjustment capabilities for each vibration component. This segmentation increases layout flexibility as each balancer can be positioned and sized independently based on specific vibration characteristics.
Solution Approach 2:
The patent employs dynamic balancing where the balancers are configured to counteract specific vibration components based on the irregular crank phase angles. The inertial force balancer and couple balancer can be independently tuned to adapt to different crank phase configurations, maintaining layout freedom while achieving effective vibration reduction.
3Object-affected harmful factors
If a biaxial primary balancer is used to reduce primary vibration, then vibration reduction is achieved, but the balancer occupies most of the space in the crankcase
Solution Approach 1:
The patent replaces the traditional single biaxial balancer with segmented inertial force and couple balancers. This segmentation allows for more efficient space utilization as each smaller balancer can be positioned optimally, reducing the total volume occupied in the crankcase while maintaining effective vibration reduction.
Solution Approach 2:
The patent extracts the vibration reduction function from a single large biaxial balancer and separates it into two smaller specialized balancers. This extraction allows the components to be positioned outside or at the periphery of the crankcase, freeing up internal space while maintaining the vibration reduction function.
4Object-affected harmful factors
If balancers are arranged inside the crankcase to reduce vibration, then vibration reduction effectiveness is maintained, but the engine cannot be downsized
Solution Approach 1:
The patent extracts the balancers from the internal crankcase space and positions them externally or at the periphery. This extraction maintains vibration reduction effectiveness while freeing up internal engine space, enabling downsizing of the overall engine package and allowing closer placement of transmission and starter components.
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 effectively reduces primary vibration, improves the degree of freedom in layout, and enables downsizing of the engine by allowing closer placement of transmission and starter components to the crankshaft, while maintaining efficient vibration reduction.
Implementation Method 1
an inertial force balancer is provided for generating force facing the inertial force component
Implementation Method 2
a couple balancer is provided for generating force facing the couple component
Data Source
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AI summary
A device is provided for reducing first cylinder vibratory force (F1) and second cylinder vibratory force (F2) which are generated when a crankshaft (5) is rotated, in a parallel twin cylinder internal combustion engine in which a crankshaft (5) is provided with a first crankpin (5PL) and a second crankpin (5PR) at a predetermined phase angle (θ) and a cylinder block (8) is formed with a first cylinder (#1) and a second cylinder (#2). In the device, a straight line for bisecting an angle formed between the first cylinder (#1) vibratory force (F1) and the second cylinder (#2) vibratory force (F2) is defined as an angle bisector (DL), force with the first cylinder (#1) vibratory force (F1) and the second cylinder (#2) vibratory force (F2) resolved in a direction parallel to the angle bisector (DL) is defined as an inertial force component, force with the first cylinder vibratory force (F1) and the second cylinder vibratory force (F2) resolved in a direction parallel to a plane perpendicular to the angle bisector (DL) is defined as a couple component, an inertial force balancer is provided for generating force facing the inertial force component, and a couple balancer is provided for generating force facing the couple component.