Ventilator-Equipped Engine Fresh Air Introduction Passage
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Solution Overview
Problem
Existing ventilator-equipped engines suffer from reduced ventilation efficiency due to fresh air flowing straight through the head cover and being discharged without circulating in the crankcase, leading to potential closure of the fresh air introduction passage at low temperatures and reduced performance under high loads.
Innovation Solution
A ventilator-equipped engine design where fresh air is directly introduced into the internal space of the cylinder head through a fresh air introduction passage that extends across the intake passage and cylinder head, with a separate fresh air introduction chamber adjacent to the intake manifold and water jacket, creating a curved path to enhance circulation and prevent direct discharge through the head cover.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If fresh air is supplied into the head cover, then the structure is simple, but the fresh air may flow straight through the head cover and be discharged without circulating in the crankcase, deteriorating ventilation efficiency
Solution Approach 1:
The patent segments the head cover internal space into distinct regions: a fresh air introduction region and a blow-by gas discharge region. By providing a partition wall that divides these spaces, the fresh air is prevented from directly mixing with and flowing through the blow-by gas discharge path, thereby ensuring proper circulation in the crankcase while maintaining structural simplicity.
2Productivity
If fresh air introduction passage is extended to introduce fresh air directly into cylinder head, then ventilation efficiency is enhanced, but the passage is exposed to outside air and may freeze and close at extremely low temperatures
Solution Approach 1:
The patent applies preliminary action by providing a heating device that pre-heats the fresh air before it enters the fresh air introduction passage. The heating device, which may be a heater or utilize engine waste heat, raises the temperature of the fresh air to above freezing point, preventing the passage from freezing and closing at extremely low temperatures, thus maintaining reliability while achieving high ventilation efficiency.
3Stress or pressure
If pressure regulating valve regulates blow-by gas flow rate, then pressure rise in crankcase is prevented, but when high load is applied, the amount of blow-by gas exceeds the regulated flow rate and may not be fully returned to intake passage
Solution Approach 1:
The patent applies dynamics by making the blow-by gas discharge passage configurable - it can be selectively connected or disconnected from the head cover based on operating conditions. When high load is applied and the pressure regulating valve cannot handle the excessive blow-by gas volume, the system dynamically switches to an alternative discharge path, ensuring complete recirculation of all blow-by gas while maintaining proper crankcase pressure control under normal conditions.
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 enhances ventilation efficiency by ensuring fresh air circulates effectively within the crankcase, reducing the risk of passage closure due to freezing and maintaining performance under high loads, while minimizing the risk of fresh air introduction passage closure.
Implementation Method 1
providing the fresh air introduction chamber with the cylinder head so as to be adjacent to a water jacket
Implementation Method 2
a blow-by gas is returned to an intake passage by a negative pressure of the intake passage through a pressure regulating valve
Data Source
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AI summary
Provided is a ventilator-equipped engine which has been improved so as to enhance ventilation efficiency in the engine by further improving a structure for introducing fresh air into the engine. The ventilator-equipped engine is configured to: guide a blow-by gas generated in a crankcase to an intake passage k through an inside of a cylinder head 2, an inside of a head cover 3, and a pressure regulating valve 27; and to directly introduce fresh air into an internal space 2S of the cylinder head 2 by providing a fresh air introduction passage 28 that extends across the intake passage k and the cylinder head 2.