Tap Valve Insert Thread Geometry for Precise Axial Positioning
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing tap valve inserts face challenges in achieving accurate and simple positioning within the tap valve due to component tolerances and surface conditions, leading to incorrect assembly and potential damage during threaded connections.
Innovation Solution
The external thread of the main valve insert features a unique design with flank angles between 25° and 70° for the outer flank portion and less than 20° for the inner flank portion, combined with a thread pitch more than twice the width of the elevations, allowing for precise thread engagement and accurate axial positioning through a simple locating of the thread entry point.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If standard or pointed threads (e.g., metric threads with 60° flank angle) are used for the threaded connection, then the threaded connection can be easily manufactured, but accurate positioning of the main valve insert along the central axis cannot be achieved due to component tolerances and surface conditions
Solution Approach 1:
The thread elevation is divided into two distinct flank portions: an outer flank portion with a larger flank angle (25°-70°) for load-bearing and self-locking, and an inner flank portion with a smaller flank angle (less than 20°) for precise guiding and positioning. This segmentation allows each portion to optimize its function independently, resolving the contradiction between easy manufacturing and precise positioning.
Solution Approach 2:
Different regions of the thread elevation are assigned different geometric properties: the outer flank portion has a larger flank angle optimized for mechanical strength and self-locking, while the inner flank portion has a smaller flank angle optimized for accurate guidance. This local differentiation enables the single thread structure to simultaneously achieve both ease of manufacture and positioning accuracy.
2Volume of moving object
If the thread pitch is small relative to the width of thread elevations, then the threaded connection is compact, but the thread entry point cannot be easily located leading to incorrect assembly
Solution Approach 1:
The thread pitch is designed to be more than twice the width of the thread elevation, creating a specific geometric parameter relationship. This parameter change makes the thread entry point easily locatable during assembly while maintaining a compact overall structure, as the enlarged pitch provides clear visual and tactile cues for alignment without excessive size increase.
3Force
If the flank angle in the outer flank portion is small (less than 20°), then the thread flanks are better for transmitting force during screwing-in, but the self-locking capability and secure hold are reduced
Solution Approach 1:
The thread elevation is segmented into two flank portions with different angle characteristics. The inner flank portion (less than 20°) optimizes force transmission during assembly, while the outer flank portion (25°-70°) provides superior self-locking and secure holding. This segmentation resolves the contradiction by assigning opposite optimization goals to different regions of the same structure.
Solution Approach 2:
Different angular properties are applied locally to different portions of the thread elevation. The inner flank uses a shallow angle for force transmission efficiency, while the outer flank uses a steeper angle for self-locking reliability. This local quality differentiation enables the thread to simultaneously achieve both force transmission and self-locking capabilities.
Data Source
AI summary
The invention relates to a main valve insert (20) for a tap valve (10) for dispensing a fluid, having a channel (13) extending through the main valve insert (20), a valve seat (21) designed to cooperate with a main valve body (14) of the tap valve (10) to control a fluid flow through the channel (13), and an external thread (22) for connecting the main valve insert (20) to the tap valve (10). According to the invention, the external thread (22) comprises, viewed in cross-section, a plurality of thread elevations (23) having an outer flank portion (24) and an inner flank portion (25), wherein a flank angle of the thread elevations (23) in the outer flank portion (24) is in the range between 25° and 70° and in the inner flank portion (25) is less than 20°, wherein a thread pitch of the external thread is more than 2 times a width of the thread elevations (23) measured at the junction between the flank portions (24, 25).