Double-Structure Ball-Cam Camshaft for Six-Cycle Pumping Loss
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Solution Overview
Problem
Conventional six-cycle internal-combustion engines suffer from pumping loss during intake and exhaust strokes, leading to reduced engine output and inferior performance compared to four-cycle engines.
Innovation Solution
Combining four-cycle strokes (intake, compression, combustion, exhaust) with two-cycle strokes (intake, compression, combustion, exhaust) and employing a valve mechanism that adjusts opening degrees based on engine speed, using a ball cam with a double structure camshaft, and incorporating an external supercharger and EGR device to optimize fuel usage and reduce pumping loss.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a six-cycle internal-combustion engine is configured by adding intake and exhaust strokes after four-cycle strokes, then the engine can operate with six strokes per cycle, but pumping loss increases during the two additional strokes, causing engine output deterioration
Solution Approach 1:
The camshaft is designed with variable cam timing that can dynamically adjust the opening and closing timing of intake and exhaust valves based on engine operating conditions. This dynamic adjustment allows the engine to optimize valve timing for different stroke sequences, reducing pumping loss during the additional intake and exhaust strokes of the six-cycle operation while maintaining engine output.
Solution Approach 2:
The invention changes the timing parameters of valve opening and closing through the variable cam timing mechanism. By adjusting these timing parameters according to engine load and speed, the system can minimize the negative impact of pumping loss during the extended six-cycle strokes while preserving the benefits of the six-cycle configuration.
2Loss of energy
If a variable cam timing mechanism with double structure camshaft is employed, then valve opening degrees can be adjusted based on engine speed to reduce pumping loss, but device complexity increases
Solution Approach 1:
The camshaft is segmented into a double structure with separate cam lobes for different valve timing control. This segmentation allows independent adjustment of intake and exhaust valve timing, enabling precise control over valve opening degrees to reduce pumping loss while maintaining a mechanically integrated solution that avoids excessive complexity.
Solution Approach 2:
The variable cam timing mechanism is nested within the existing camshaft structure, with the double structure camshaft integrating multiple functions into a single component. This nesting approach allows the complex variable timing functionality to be incorporated without proportionally increasing overall device complexity, as the mechanism shares common structural elements with the base camshaft design.
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 reduces pumping loss, increases output, and enhances thermal efficiency, making it suitable for gasoline and diesel engines, with improved fuel consumption and reduced environmental impact.
Implementation Method 1
using a ball cam with a double structure camshaft
Implementation Method 2
incorporating an external supercharger
Implementation Method 3
incorporating an external supercharger and EGR device to optimize fuel usage
Data Source
AI summary
A camshaft includes, as a cam that opens and closes an exhaust valve and an intake valve, a ball cam whose protrusion amount changes according to rotation of the camshaft, wherein the camshaft has a double structure consisting of an inner shaft and an outer shaft provided in a manner that the inner shaft is helically displaced with respect to the outer shaft around an axis of the camshaft according to a rotation speed of the camshaft, and the ball cam is accommodated movably in a guide groove provided in the inner shaft and protrudes from the outer shaft, and a protrusion amount of the ball cam from the outer shaft changes when the ball cam moves in the guide groove due to the helical displacement of the inner shaft with respect to the outer shaft.