Exhaust Sensor Alignment Using Intake Negative Pressure
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Solution Overview
Problem
Engines with low engine displacement, such as those in passenger cars or small commercial vehicles, often lack an air compressor for generating positive pressure, and existing exhaust sensors can be contaminated by oil from turbo compressors when using positive pressure from turbo compressors.
Innovation Solution
An exhaust sensor arrangement structure that utilizes negative pressure during the engine's intake stroke to draw in air and exhaust gas, with connections between the exhaust pipe, intake pipe, and atmosphere pipe, eliminating the need for a positive pressure-generating device, and optionally includes a turbo compressor, metering valve, and filter.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If an air compressor is used to generate positive pressure for supplying air to the exhaust sensor, then the exhaust sensor can obtain sufficient air for measurement, but the device complexity and cost increase
Solution Approach 1:
The system uses the engine's own intake negative pressure to supply air to the exhaust sensor, eliminating the need for external air compressors. The exhaust sensor arrangement structure self-regulates air intake through the atmosphere pipe connected to the intake manifold, where the engine's suction during intake strokes naturally draws in the required air.
Solution Approach 2:
The intake manifold serves multiple functions: it not only supplies air to the engine cylinders but also provides air to the exhaust sensor through the atmosphere pipe. This multi-functional use of the existing intake system eliminates the need for dedicated air compression equipment.
2Quantity of substance
If a turbo compressor is used to generate positive pressure for supplying air to the exhaust sensor, then sufficient air can be supplied, but the exhaust sensor may be contaminated with oil from the turbo compressor
Solution Approach 1:
The system extracts air supply function from the turbo compressor and relocates it to the intake manifold. By connecting the atmosphere pipe to the intake manifold rather than using turbo compressor output, the design separates the air supply function from the pressure generation function, eliminating oil contamination risks while maintaining adequate air supply.
3Device complexity
If no positive pressure-generating device is used, then the device complexity is reduced, but it is difficult to supply sufficient air to the exhaust sensor for measurement
Solution Approach 1:
The exhaust sensor system leverages the engine's own operation to supply air. During intake strokes, the engine creates negative pressure that automatically draws air through the atmosphere pipe into the exhaust sensor, eliminating the need for external pressure-generating devices while ensuring adequate air supply for measurement.
Solution Approach 2:
The system utilizes the periodic negative pressure generated during engine intake strokes to supply air to the exhaust sensor. This periodic suction action, synchronized with the engine's four-stroke cycle, continuously replenishes air in the exhaust sensor without requiring continuous positive pressure generation.
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
Enables the supply of air required for exhaust gas component measurement without a positive pressure-generating device, preventing contamination and ensuring efficient operation.
Implementation Method 1
air is sucked into the exhaust sensor through the atmosphere pipe due to intake negative pressure generated during an intake stroke of the engine
Data Source
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AI summary
Air required for measurement of exhaust gas components is supplied to an exhaust sensor without using a device for generating positive pressure. In a structure for arrangement, in an engine (1), of an exhaust sensor (10) that measures exhaust gas components and requires air for the measurement of the exhaust gas components, an exhaust pipe (5) of the engine (1) communicates with the exhaust sensor (10) through an introduction pipe (15), the exhaust sensor (10) communicates with an intake pipe (2) of the engine (1) through a discharge pipe (16), and an atmosphere pipe (17) open to the atmosphere is connected to the exhaust sensor (10), so that exhaust gas is sucked into the exhaust sensor (10) through the introduction pipe (15) while air is sucked into the exhaust sensor (10) through the atmosphere pipe (17) due to intake negative pressure generated during an intake stroke of the engine (1).