Main Valve Insert Thread Geometry for Precise Tap Valve Positioning
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Solution Overview
Problem
Existing main valve inserts for dispensing nozzles lack precise and easy positioning within the dispensing valve, leading to potential incorrect assembly and damage due to component tolerances and surface finishes influencing friction.
Innovation Solution
The design of the external thread with varying flank angles (25°-70° for outer and <20° for inner) and a large thread pitch (twice the width of projections) facilitates precise positioning by ensuring easy thread entry and defined axial placement, aided by a guide projection for radial and axial alignment.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If standard or tapered threads with flank angle of 60° are used for threaded connection, then the connection is secure, but precise positioning of the main valve insert is difficult and assembly may be incorrect due to tolerances and surface finishes
Solution Approach 1:
The thread profile is divided into two distinct zones: an outer flank section with 25°-70° angle for load-bearing connection security, and an inner flank section with <20° angle for precise motion transmission and positioning. This local differentiation allows each section to optimize its function independently.
Solution Approach 2:
The thread projection is segmented into outer and inner flank sections with different geometric properties. The outer flank provides friction-based self-locking for secure connection, while the inner flank provides low-friction motion transmission for precise positioning, resolving the contradiction between security and precision.
2Device complexity
If standard threads are used, then the threaded connection is simple, but the main valve insert positioning is not precise and damage may occur during assembly
Solution Approach 1:
Different sections of the thread profile serve different protective functions: the outer flank with larger angle prevents over-tightening through self-locking, while the inner flank with smaller angle guides precise engagement, collectively preventing assembly damage without complicating the overall design.
3Manufacturing precision
If large thread pitch is used (more than twice the width of thread projections), then precise positioning and easy thread entry are achieved, but the thread structure becomes more complex
Solution Approach 1:
The thread pitch is specifically designed to be more than twice the width of thread projections, creating sufficient spacing for easy entry and precise positioning. This parameter optimization achieves high precision without requiring complex additional structures.
4Ease of operation
If friction from component tolerances and surface finishes is present, then assembly is difficult and incorrect assembly may occur, but eliminating it requires more complex precision mechanisms
Solution Approach 1:
The inner flank section with <20° angle creates a low-friction interface that minimizes the impact of tolerances and surface finishes on assembly ease, while the outer flank maintains precision through its geometric self-locking特性.
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 enables secure, precise, and damage-free assembly of the main valve insert, reducing incorrect assembly risks and ensuring optimal force transmission and positioning for effective operation.
Implementation Method 1
The external thread, viewed in cross-section, has a plurality of thread projections, each having an outer flank section and an inner flank section, wherein the flank angle of the thread projections in the outer flank section is in the range between 25° and 70° and in the inner flank section is less than 20°
Implementation Method 2
component tolerances and surface finishes influencing friction
Implementation Method 3
The flank angle of the thread projections in the outer flank section is in the range between 25° and 70° and in the inner flank section is less than 20°
Data Source
Figure 1
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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).