Motorcycle Exhaust Oxygen Sensor Placement
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Solution Overview
Problem
Existing exhaust devices for motorcycles face challenges in detecting catalyzer deterioration and optimizing the placement of oxygen sensors for effective performance and appearance, especially on saddle-type vehicles with limited space.
Innovation Solution
The exhaust device incorporates two oxygen sensors positioned upstream and downstream of the catalyzer within a larger-diameter portion, utilizing a heaterless design and dispersing means to enhance measurement accuracy and reduce exposure, while the catalyzer is housed in a larger-diameter portion with a bent outlet pipe to optimize space utilization and appearance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If two oxygen sensors are installed upstream and downstream of the catalyzer for deterioration detection, then the ability to detect catalyzer deterioration is improved, but the device complexity and space requirements increase
Solution Approach 1:
The patent combines both upstream and downstream oxygen sensors into a single exhaust pipe section that houses the catalyzer. The sensors are integrated into the same structural component (the exhaust pipe with larger-diameter portion), merging multiple sensing functions into one location rather than requiring separate mounting points throughout the exhaust system.
Solution Approach 2:
The oxygen sensors are positioned within the larger-diameter portion of the exhaust pipe that contains the catalyzer. This nested arrangement allows the sensors to be housed within the same structural space as the catalyzer, utilizing the available volume efficiently and reducing the need for additional external mounting structures.
2Ease of repair
If oxygen sensors are exposed outwardly for functional access, then ease of maintenance is improved, but the appearance is worsened and vulnerability to damage increases
Solution Approach 1:
The exhaust pipe is designed with a localized larger-diameter portion that specifically houses the catalyzer and oxygen sensors. This creates a dedicated functional zone with different structural characteristics (larger diameter) than the rest of the exhaust pipe, allowing the sensors to be protected within this specific section while maintaining overall system functionality.
Solution Approach 2:
The patent positions the oxygen sensors in the vertical dimension (upwardly of the central line) rather than exposing them laterally. This dimensional repositioning allows the sensors to be accessible from above while being shielded from lateral impacts and improving appearance by hiding them within the exhaust pipe structure.
3Weight of moving object
If the exhaust pipe maintains a small diameter to reduce weight, then the weight is reduced, but the space available for housing the catalyzer and sensors is limited
Solution Approach 1:
The exhaust pipe features a localized larger-diameter portion rather than being uniformly large-diameter throughout. This allows the catalyzer and sensors to be housed in a specific section with increased volume, while the rest of the exhaust pipe maintains a smaller diameter to minimize overall weight.
Solution Approach 2:
The catalyzer and oxygen sensors are nested within the larger-diameter portion of the exhaust pipe, utilizing the increased volume only where needed. This nested arrangement maximizes the use of available space for housing components without requiring the entire exhaust pipe to be large-diameter, thereby reducing overall weight.
4Power
If the cylinder axis is inclined forwardly for optimal engine performance, then the engine performance is improved, but the positioning of the larger-diameter portion becomes more constrained
Solution Approach 1:
The exhaust pipe is designed with a flexible layout that includes a bent portion, allowing the larger-diameter portion to be positioned at an angle relative to the cylinder axis. This dynamic positioning capability enables the exhaust system to adapt to the inclined cylinder axis configuration while maintaining optimal engine performance.
Solution Approach 2:
The patent utilizes the vertical dimension by positioning the larger-diameter portion and sensors upwardly of the central line, creating a three-dimensional layout that accommodates the inclined cylinder axis. This spatial repositioning in the vertical dimension provides the necessary flexibility to maintain both engine performance and proper exhaust system function.
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 allows for effective detection of catalyzer deterioration, improved sensor accuracy, reduced costs due to heaterless sensors, and enhanced appearance by minimizing sensor exposure, while effectively utilizing available space on motorcycles.
Implementation Method 1
a catalyzer (C) for purifying an exhaust gas
Implementation Method 2
an upstream oxygen sensor (U) disposed on said pipe section (19) and positioned upstream of said catalyzer (C) and a downstream oxygen sensor (D) disposed on said pipe section (19) and positioned downstream of said catalyzer (C)
Data Source
AI summary
An exhaust device for a saddle-type vehicle having a pipe section with respect to a vehicle body and housing a catalyzer therein, and a muffler connected to a rear end of the pipe section includes an upstream oxygen sensor disposed on the pipe section and positioned upstream of the catalyzer and a downstream oxygen sensor disposed on the pipe section and positioned downstream of the catalyzer. The pipe section includes a larger-diameter portion having an increased diameter for housing the catalyzer therein. The downstream oxygen sensor is disposed in the larger-diameter portion. The upstream oxygen sensor and the downstream oxygen sensor are positioned upwardly of a central line of the larger-diameter portion with respect to the vehicle body as viewed in side elevation of the vehicle body.