Adjusting Screw Tappet Clearance Setting with Undulation Compensation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The existing methods for setting tappet clearance in engines face challenges due to processing distortions in the end surfaces of adjusting screws, leading to errors in clearance settings, which affect valve operation efficiency and noise levels.
Innovation Solution
A method and device that continuously measure and calculate the movement of the adjusting screw's end surface during return rotation, accounting for undulation and distortion, to accurately set the tappet clearance to a prescribed value by integrating a screwdriver, measuring unit, and return rotation control system.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If the end surface of the adjusting screw is processed with high precision to reduce distortion, then manufacturing precision is improved, but manufacturing cost and process complexity increase significantly
Solution Approach 1:
The invention converts the harmful effect of end surface distortion into a measurable parameter. By using a displacement sensor to detect the undulation amount caused by distortion during return rotation, the system compensates for the distortion effect through calculation, transforming a manufacturing defect into a correctable measurement variable.
Solution Approach 2:
The invention replaces the need for high-precision mechanical machining with a measurement and calculation system. Instead of relying on precision processing to eliminate distortion, the system uses a displacement sensor to measure the actual distortion and compensates through computational adjustment of the clearance value.
2Reliability
If the tappet clearance is set to an optimal value with narrow tolerance, then engine efficiency and noise reduction are improved, but measurement precision requirements increase
Solution Approach 1:
The invention implements feedback by continuously measuring the actual position of the adjusting screw end surface during return rotation using a displacement sensor. The system monitors the undulation movement in real-time and uses this feedback to calculate the precise clearance value, ensuring accurate setting despite manufacturing variations.
Solution Approach 2:
The invention performs preliminary measurement of the undulation amount during the return rotation phase before final clearance setting. By measuring and calculating the distortion effect in advance, the system can compensate for it when determining the final clearance value, ensuring accurate setting.
3Ease of operation
If the adjusting screw rotation is returned based on calculated movement amount from screw pitch and rotation angle, then ease of operation is improved, but measurement precision deteriorates due to unaccounted undulation
Solution Approach 1:
The invention introduces a displacement sensor as an intermediary measurement device between the adjusting screw and the clearance determination process. This sensor directly measures the actual movement and undulation of the screw end surface, providing accurate data that bridges the gap between simple rotational control and precise clearance measurement.
Data Source
AI summary
Even in the case where, due to distortion (undulation) or the like of an end surface of an adjusting screw abutting on a valve stem end, there exists a non-linear undulation movement amount in a movement amount of the end surface with respect to a rotation return angle of the adjusting screw, the undulation movement amount is continuously measured, and a screw return movement amount based on a screw pitch and on the rotation return angle is continuously calculated, and, when a total movement amount of the undulation movement amount and the screw return movement amount has attained a prescribed clearance, return rotation is ended.