Premixed Compression Ignition Engine Intake Passage Segmentation
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Solution Overview
Problem
Premixed compression ignition type engines without a supercharger face challenges in managing the excess or deficiency of intake mixture when switching between spark ignition and homogeneous charge compression ignition combustion, as existing solutions rely on superchargers to control ignition timing and mixture conditions.
Innovation Solution
The engine incorporates a first and second branch intake passage, a common intake passage with a fuel supply for mixing, a switching valve to direct the mixture flow between these passages, and a throttle valve for flow rate adjustment, controlled by an ECU to ensure stable mixture supply during combustion mode transitions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If the throttle valve is controlled to fully open upon switching from SI combustion to HCCI combustion, then the mixture supply is maximized, but the amount of mixture supplied to the combustion chamber remains insufficient due to negative pressure in the intake passage
Solution Approach 1:
The intake passage is divided into a first branch intake passage with a throttle valve and a second branch intake passage without a throttle valve. By segmenting the intake system, the patent allows selective routing of mixture flow to different combustion chambers, enabling independent control of mixture supply during combustion mode transitions and eliminating the negative pressure problem in the second branch passage.
2Reliability
If the amount of in-cylinder gas is increased when switching from SI combustion to HCCI combustion, then stable HCCI combustion is achieved, but the throttle valve must close causing negative pressure and insufficient mixture supply
Solution Approach 1:
The intake passage is divided into a first branch intake passage with a throttle valve and a second branch intake passage without a throttle valve. By segmenting the intake system, the patent allows selective routing of mixture flow to different combustion chambers, enabling independent control of mixture supply during combustion mode transitions and eliminating the negative pressure problem in the second branch passage.
3Reliability
If a supercharger is used to control ignition timing and mixture conditions, then HCCI combustion is enabled, but the engine structure becomes more complex and the solution does not apply to engines without a supercharger
Solution Approach 1:
The intake passage is divided into a first branch intake passage with a throttle valve and a second branch intake passage without a throttle valve. By segmenting the intake system, the patent allows selective routing of mixture flow to different combustion chambers, enabling independent control of mixture supply during combustion mode transitions and eliminating the negative pressure problem in the second branch passage.
Solution Approach 2:
The switching valve dynamically routes the mixture flow between the first and second branch intake passages based on the required combustion mode. This dynamic switching capability allows the engine to adapt between SI and HCCI combustion modes without requiring a supercharger, simplifying the overall engine structure while maintaining control flexibility.
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 prevents mixture deficiency during HCCI to SI transitions and excess during SI to HCCI transitions, maintaining stable combustion by adjusting mixture flow rates and internal EGR, regardless of the presence of a supercharger.
Implementation Method 1
a fuel supply device provided in the common intake passage, for mixing air with fuel to produce a mixture
Implementation Method 2
a fuel supply device provided in the common intake passage, for mixing air with fuel to produce a mixture
Implementation Method 3
a switching means for bringing the common intake passage into communication with at least one of the first branch intake passage and the second branch intake passage
Implementation Method 4
a flow rate adjusting means provided in the first branch intake passage, for controlling a flow rate of the mixture flowing through the first branch intake passage
Implementation Method 5
premixed compression self-ignition (HCCI) type engines which operate with high efficiency
Data Source
AI summary
An intake passage (10) communicating with a combustion chamber (3) comprises a first branch intake passage (16) having an intake port (4) at one end thereof and also having an intake manifold including a surge tank (13), a second branch intake passage (17) having an intake port (14) at one end thereof and also having an intake manifold including a surge tank (23), and a common intake passage (19) communicating with the ends of the first branch intake passage (16) and the second branch intake passage (17). The common intake passage (19) is provided with a mixer (11) for producing a mixture. The intake passage (10) is provided with a switching valve (18) for bringing the common intake passage (19) into communication with at least one of the first branch intake passage (16) and the second branch intake passage (17).