Straddled Vehicle Catalyst Temperature Control
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Solution Overview
Problem
Motorcycles face challenges in enhancing exhaust gas purification performance without enlarging the catalyst, which is limited by installation space, and existing solutions do not provide freedom in catalyst arrangement while maintaining performance.
Innovation Solution
A control device manages fuel injection in a straddled vehicle to perform intermittent injections, including minimum and intermediate fuel injections, to regulate catalyst temperature and enhance purification performance without enlarging the catalyst, allowing for flexible arrangement.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the catalyst is enlarged to increase the surface area, then the exhaust gas purification performance is enhanced, but the installation space is exceeded and the vehicle size increases
Solution Approach 1:
The invention changes the operational parameters of the catalyst by controlling the temperature through intermittent fuel injection. Instead of increasing the physical size of the catalyst, the system optimizes the thermal conditions (temperature parameter) to enhance purification performance. The fuel injection amount is adjusted to maintain catalyst temperature within an optimal range, thereby improving exhaust gas purification without enlarging the catalyst volume.
2Reliability
If the catalyst is enlarged to increase the surface area, then the exhaust gas purification performance is enhanced, but the installation space is exceeded
Solution Approach 1:
The invention resolves this contradiction by changing the operational parameters rather than the physical dimensions. By controlling the catalyst temperature through fuel injection management, the system achieves enhanced purification performance within the existing installation space constraints. The catalyst remains compact while operating at optimized temperatures for maximum efficiency.
3Power
If minimum fuel injection is performed periodically to reduce engine output torque, then the drive power is reduced, but the catalyst temperature rises excessively
Solution Approach 1:
The invention implements a feedback control mechanism where the fuel injection amount is adjusted based on the catalyst temperature. When the catalyst temperature rises excessively due to minimum fuel injection, the system detects this condition and increases the fuel injection amount to cool the catalyst. This closed-loop feedback ensures that both engine output torque and catalyst temperature are maintained within optimal ranges.
Solution Approach 2:
The system uses periodic fuel injection with variable amounts to control catalyst temperature. Instead of uniform minimum fuel injection, the invention applies periodic fuel injection where the amount varies based on catalyst temperature conditions. This periodic action with modulation allows the system to reduce engine output torque when needed while preventing excessive catalyst temperature rise.
4Reliability
If the fuel injection amount is increased to cool the catalyst, then the exhaust gas purification performance is improved, but the engine output torque decreases
Solution Approach 1:
The invention uses feedback control to balance exhaust gas purification performance and engine output torque. The fuel injection amount is dynamically adjusted based on catalyst temperature and purification performance requirements. When purification performance needs improvement, the system increases fuel injection to cool the catalyst, but only to the extent necessary to maintain optimal operation, thereby minimizing the impact on engine output torque.
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 approach effectively suppresses excessive catalyst temperature and improves exhaust gas purification performance, enabling freedom in catalyst arrangement without increasing the vehicle's size.
Implementation Method 1
a catalyst disposed in the exhaust passage
Implementation Method 2
The injector is disposed at a location between the throttle valve and the combustion chamber, and is configured to inject fuel toward the intake air flowing through the intake passage part
Data Source
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AI summary
Provided is a straddled vehicle including a catalyst for purifying exhaust gas discharged from a combustion chamber of an engine, the straddled vehicle being capable of enhancing exhaust gas purification performance even without enlarging the catalyst and therefore achieving freedom in arrangement of the catalyst. A control device controls fuel injection of an injector to satisfy the following (A), (B), and (C) with a throttle valve open and its opening degree constant. (A) A minimum fuel injection, by which fuel is injected in a minimum fuel injection amount, takes place plural times intermittently. (B) An intermediate fuel injection takes place plural times between two of the plural minimum fuel injections taking place intermittently, the intermediate fuel injection being greater in amount than the fuel injection amount for the minimum fuel injection, the intermediate fuel injection done by accordingly injecting the fuel into the intake passage part. (C) Amounts of the fuel injections for at least two of the plural intermediate fuel injections differ from each other.