Engine Valve System Plunger Guide Sleeve Assembly
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Solution Overview
Problem
Existing engine valve systems with cam summation mechanisms are difficult to assemble and adjust, particularly in maintaining desired clearance with hydraulic lash adjusters when the valve is fully closed.
Innovation Solution
The engine valve system features two coaxially mounted cams with a summation mechanism and a hydraulic lash adjuster, where the control spring and adjustment means are decoupled from the assembly process, allowing for simpler assembly and adjustment by using a plunger and guide sleeve system that can be assembled and adjusted externally, enabling precise clearance setting.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If the rod is pivotably connected to the summation lever and connected to a stationary component with an arrangement that allows clearance to be set, then the clearance can be set in the system, but the assembly process becomes difficult and complex
Solution Approach 1:
The invention divides the clearance setting function into separate components: the guide sleeve remains stationary while the plunger provides adjustable positioning. This segmentation allows the plunger to be independently adjusted to set clearance without requiring complex pivotable connections between the rod and summation lever, thereby simplifying assembly while maintaining precision.
Solution Approach 2:
The plunger acts as an intermediary element between the control spring and the stationary component. By introducing this intermediate adjustable element, the system achieves precise clearance setting through the plunger's position relative to the guide sleeve, avoiding the need for complex pivotable connections and making assembly straightforward.
2Device complexity
If the control spring and adjustment means are integrated into the assembly, then the structure is compact, but the assembly and adjustment process becomes difficult
Solution Approach 1:
The invention segments the adjustment mechanism into a stationary guide sleeve and a movable plunger with external adjustment capability. This allows the control spring to be pre-assembled in a compact manner while the plunger can be independently adjusted after assembly, resolving the conflict between structural compactness and assembly ease.
3Adaptability or versatility
If a pivotable connection is used for the rod, then the clearance can be adjusted, but measurement and verification of valve lift characteristics becomes difficult
Solution Approach 1:
The plunger serves as a measurable intermediary whose position relative to the guide sleeve directly indicates the clearance setting. This linear, accessible positioning system allows for straightforward measurement and verification of valve lift characteristics, replacing the difficult-to-measure pivotable connection system while maintaining full adjustability.
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 design simplifies the assembly and adjustment process, allowing for accurate setting of operating clearance and improved valve system performance by decoupling the control spring from the assembly, enabling easier measurement and verification of valve lift characteristics and timing.
Implementation Method 1
a hydraulic lash adjuster to maintain a desired clearance in the system when the valve is fully closed
Implementation Method 2
A disadvantage of the configuration in Figure 1 is that it is difficult to assemble the valve system and to set the clearance in the system
Data Source
Figure 1~2C
Figure 3A~4B
Figure 5A~6C
AI summary
A engine valve system is discloses that comprises two coaxially mounted cams (10, 12), a summation lever (14) movable in proportion to the sum of the instantaneous lifts of the respective cams, and a valve actuating rocker (20) pivoted to the summation lever (14) and acting on an engine valve (24). The actuating rocker (20) rests on a hydraulic lash adjuster (22), and a control spring (30) compresses the hydraulic lash adjuster (22). A stop is provided to limit expansion of the control spring (30). In the invention, the control spring (30) acts on the summation lever by way of a plunger ('42) that is constrained to reciprocate linearly within a bore that is stationary relative to the engine block and an end of the plunger ('42) is in sliding engagement with the summation lever (14), whereby a point of contact between the plunger ('42) and the summation rocker (14) is displaced in a direction transverse to the axis of the plunger during pivoting movement of the summation lever (14).