Motorcycle Exhaust Oxygen Sensor Mounting via Stand Overlap
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Solution Overview
Problem
Existing exhaust devices for saddle-type vehicles face challenges in detecting catalyst deterioration and maintaining purifying performance, especially in limited spaces where oxygen sensors must be positioned both functionally and aesthetically, while preventing failures and exposure to external elements.
Innovation Solution
The exhaust device incorporates two oxygen sensors, one heaterless upstream and one heater-mounted downstream, positioned to overlap with the stand device for protection and mounted in a way that utilizes existing components for a neat appearance, with a catalyst diagnosing unit to detect deterioration and activate an indicator for the rider.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If two oxygen sensors are installed for catalyst deterioration detection, then the purifying performance monitoring is improved, but the device complexity and space requirements increase
Solution Approach 1:
The exhaust pipe structure serves multiple functions: it acts as both the exhaust gas passage and a protective cover for the oxygen sensors. The pipe wall integrates sensor mounting provisions, eliminating the need for separate protective housings and reducing overall device complexity while maintaining reliable deterioration detection capability
Solution Approach 2:
The protective cover and oxygen sensor mounting structure are merged into a single integrated component. The exhaust pipe itself becomes the protective enclosure, with sensors mounted directly to the pipe wall, combining structural support, protection, and sensor housing functions into one element
2Reliability
If oxygen sensors are positioned exposed outwardly for functional access, then the deterioration detection function is maintained, but the sensors become vulnerable to external damage and aesthetic appearance deteriorates
Solution Approach 1:
The exhaust pipe wall acts as an intermediary structure between the oxygen sensors and the external environment. Sensors are mounted on the outer surface of the pipe, using the pipe wall as a protective barrier against stones, water, and other external hazards while maintaining sensor accessibility and aesthetic appearance
3Measurement precision
If oxygen sensors are mounted inside the exhaust pipe for optimal measurement, then the detection accuracy is improved, but the sensors become difficult to access and protect from external factors
Solution Approach 1:
Instead of mounting sensors radially inside the pipe where they would be difficult to access, the sensors are positioned on the outer cylindrical surface of the exhaust pipe. This dimensional relocation maintains measurement functionality while dramatically improving accessibility for installation, maintenance, and protection from external elements
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 catalyst deterioration, protection from external factors, and efficient use of space, ensuring the exhaust device maintains performance and appearance while preventing the vehicle from being operated with a deteriorated catalyst.
Implementation Method 1
a catalyzer for purifying an exhaust gas that is disposed midway in an exhaust passage
Implementation Method 2
an oxygen sensor (O2 sensor) for detecting the oxygen concentration of the exhaust gas
Implementation Method 3
said upstream oxygen sensor includes a heaterless oxygen sensor free of a heater function and said downstream oxygen sensor includes a heater-mounted oxygen sensor with a heater function
Data Source
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AI summary
An exhaust device (20) for a saddle-type vehicle having a pipe section (19) with respect to a vehicle body and housing a catalyzer (C) therein, and a muffler (26) connected to a rear end of the pipe section (19) includes an upstream oxygen sensor (U) positioned upstream of the catalyzer (C) and a downstream oxygen sensor (D) positioned downstream of the catalyzer (C). The downstream oxygen sensor (D) is disposed in either a position overlapping a main stand (22) for supporting a motorcycle (1) as viewed from below the vehicle body when the main stand (22) is stored, or a position overlapping a stand receiver (90) for abutting against the main stand (22) as viewed from below the vehicle body when the main stand (22) is stored. The pipe section (19) includes a larger-diameter portion (61) having an increased diameter for housing the catalyzer (C) therein.