Permanent Magnet AC Generator Braking for Vehicle Deceleration
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Solution Overview
Problem
Engine-equipped vehicles face challenges in providing a comfortable deceleration experience while suppressing fuel consumption, as existing systems can make riders feel uncomfortable during engine braking and struggle to balance gear shifting characteristics effectively.
Innovation Solution
The implementation of a permanent magnet type AC generator that applies a braking force to the crankshaft by short-circuiting its windings, allowing for adjustable braking force based on battery charge state, enabling more design freedom in deceleration feel and reduced fuel consumption.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If a transmission with lower gear ratio is adopted to suppress fuel consumption, then fuel efficiency is improved, but engine braking performance deteriorates making riders feel uncomfortable
Solution Approach 1:
The patent introduces a generator as an intermediary device between the engine and the transmission system. The generator applies a braking force to the crankshaft through electromagnetic resistance when the throttle is closed during deceleration, compensating for the reduced engine braking effect caused by lower gear ratios. This allows the transmission to maintain low gear ratios for fuel efficiency while the generator provides the necessary deceleration force for rider comfort.
2Use of energy by moving object
If engine resistance is reduced to suppress fuel consumption, then fuel efficiency is improved, but deceleration control capability deteriorates
Solution Approach 1:
The patent implements dynamic control of the generator's braking force based on vehicle deceleration requirements. The control device adjusts the generator's electromagnetic resistance in real-time according to the throttle opening degree and vehicle speed, enabling flexible deceleration control. This allows the engine to operate with reduced resistance for fuel efficiency while the generator dynamically compensates to provide appropriate deceleration control across different driving conditions.
3Use of energy by moving object
If gear shifting characteristics are optimized for fuel efficiency, then fuel consumption is reduced, but deceleration response becomes sluggish
Solution Approach 1:
The patent replaces the reliance on mechanical engine braking (which is weakened by fuel-efficient gear ratios) with electromagnetic braking through the generator. By substituting the mechanical deceleration mechanism with an electromagnetic one, the system can maintain optimized gear shifting characteristics for fuel efficiency while the generator provides rapid and responsive deceleration force when needed, improving overall deceleration response.
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 solution enhances the deceleration experience by providing adjustable braking force and reducing engine braking resistance, thereby improving comfort and fuel efficiency.
Implementation Method 1
a permanent magnet type AC generator which generates electric power in accordance with rotation of a crankshaft
Implementation Method 2
the permanent magnet type AC generator applies a load to rotation of the crankshaft, the magnitude of the load being depending on a current produced in the electric power generation
Data Source
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AI summary
An object of the present teaching is to provide an engine-equipped vehicle capable of giving more design freedom in terms of a brake control at a time of deceleration while giving more design freedom in terms of suppression of fuel consumption in an engine, and an engine-equipped vehicle includes: an engine; a drive member; a permanent magnet type AC generator; a battery; an inverter disposed between the permanent magnet type AC generator and the battery, the inverter including a plurality of switching parts that adjust a current to be outputted from the permanent magnet type AC generator; an acceleration command part that instructs that the rotational power of the engine be increased or decreased in accordance with an operation performed thereon; and a control device that directs the plurality of switching parts included in the inverter to bring the winding of the permanent magnet type AC generator into a short-circuit state, if an instruction to decrease the rotational power of the engine is given by the acceleration command part while the engine-equipped vehicle is in motion.