Nested Valve Arrangement for Turbocharged Engine Air Supply
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Solution Overview
Problem
Turbocharged diesel engines in heavy-duty vehicles experience inadequate torque and power during low rpm conditions due to turbo lag, leading to reduced performance and increased fuel smoke from incomplete combustion, as the turbocharger hinders air supply and requires fuel limitation.
Innovation Solution
A valve arrangement with a first valve and a second valve coaxially arranged within the first valve, featuring a junction leakage preventing means to reduce liquid leakage and coking, allowing additional air supply to the combustion chamber, and a guide leakage preventing means to prevent liquid from entering the valve guide air passage, enhancing performance and reducing wear.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If a valve-in-valve arrangement is used to supply additional air to the combustion chamber, then engine torque and power are improved during low rpm conditions, but liquid leakage and coking increase due to environmental conditions in the engine
Solution Approach 1:
The second valve is nested within the first valve, with the second valve stem assembly positioned inside the first valve stem assembly. This nested configuration allows additional air supply while maintaining a compact structure that reduces exposure to harmful environmental conditions in the engine.
Solution Approach 2:
A junction seal is introduced as an intermediary element between the first valve stem assembly and the second valve stem assembly. This seal acts as a protective barrier that prevents liquid leakage and coking from affecting the valve stems, thereby improving reliability while maintaining the power-enhancing function.
2Quantity of substance
If the second valve is positioned within the internal cavity of the first valve, then additional air supply is enabled, but junction leakage occurs between the valve stem assemblies
Solution Approach 1:
The junction seal serves as an intermediary protective element positioned between the first valve stem assembly and the second valve stem assembly. It specifically addresses the harmful effect of liquid leakage at the junction while preserving the air supply function of the nested valve configuration.
Solution Approach 2:
The junction seal is implemented as a flexible sealing element that can adapt to the junction between the valve stem assemblies. This flexible film structure effectively blocks liquid leakage pathways while allowing the nested valve arrangement to maintain its air supply function.
3Loss of time
If the valve arrangement operates in the engine environment, then turbo lag is reduced, but wear increases due to environmental stresses
Solution Approach 1:
The junction seal acts as a protective intermediary that shields the valve stem assemblies from harmful environmental factors such as liquid leakage and coking. This protection reduces wear and maintains the strength of the valve components during operation.
Solution Approach 2:
The nested valve configuration protects the second valve and its stem assembly within the internal cavity of the first valve. This nesting provides a degree of shielding from environmental stresses while enabling the rapid air supply needed to reduce turbo lag.
Data Source
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Figure 3a
AI summary
The invention relates to a valve arrangement (200) for supplying air to a combustion chamber of an internal combustion engine, said valve arrangement comprising a first valve (206), said first valve (206) comprising a first valve head (208), a first valve stem assembly (212) and an internal cavity (224), which is at least partly located in the first valve stem assembly (212), said first valve (206) being movable between an upper, closed position of the valve, and a lower, open position, in which open position air may be supplied to the combustion chamber past the first valve head (208), a second valve (226) partly arranged within said internal cavity (224) of said first valve (206), said second valve (226) comprising a second valve head (228) and a second valve stem assembly (232), and being movable within said internal cavity between an upper, closed position, in which closed position said second valve head (228) is in contact with an inner surface (230) of said first valve head (208), and a lower, open position in which open position additional air may be supplied to the combustion chamber via said internal cavity (224) past the second valve head (228), wherein a junction seal (223) extending over a junction between said first valve stem assembly (212) and said second valve stem assembly (232), when said second valve 226 is in said closed position. A leakage preventing means (400) is arranged to hinder leakage of liquid from the outside of said junction seal (223) from reaching in between said first valve stem assembly (212) and said second valve stem assembly (232).