Needle Valve Seat Self-Centering During Oscillating Assembly
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Solution Overview
Problem
The precise positioning and fixing of valve seats with respect to valve needles in needle valves, especially with smaller diameters, pose challenges for achieving good sealing performance due to the high demands on assembly precision.
Innovation Solution
A method involving an oscillating movement of the valve needle while the valve seat plate is initially fastened to the housing with limited movement, allowing self-centering of the valve seat during the assembly process, with preferred frequencies around 50 Hz and using carbide for the needles and stainless steel for the seat plate to enhance precision and sealing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If the valve seat plate is fixed to the housing in the first step, then the assembly structure is simplified, but the positioning precision of the valve seat with respect to the valve needle deteriorates
Solution Approach 1:
The valve seat plate is designed with dynamic characteristics that allow it to oscillate at specific frequencies (10-100 Hz, preferably 30-70 Hz, more preferably 45-55 Hz) during the assembly process. This dynamic behavior enables the valve seat to self-center relative to the valve needle through controlled oscillations, achieving precise positioning that would be difficult to obtain through static assembly methods alone.
Solution Approach 2:
The invention utilizes mechanical vibration by setting the valve needle into oscillating movement during assembly. This vibration causes the valve seat to self-center with respect to the valve needle, improving positioning precision. The oscillating movement creates dynamic conditions that facilitate accurate alignment between the valve seat and valve needle, resolving the contradiction between simple assembly structure and high positioning precision.
2Length of moving object
If the valve needle diameter is reduced, then the outlet opening size is reduced for better precision application, but the assembly precision requirements increase
Solution Approach 1:
The assembly method employs self-centering of the valve seat with respect to the valve needle through oscillating movement. This self-service mechanism automatically achieves precise positioning without requiring complex external positioning devices or manual adjustment, thereby maintaining high assembly precision even when working with smaller diameter valve needles and correspondingly smaller outlet openings.
3Device complexity
If the valve seat plate is fully fixed early in assembly, then the assembly process is simplified, but the ability to achieve self-centering deteriorates
Solution Approach 1:
The valve seat plate is preliminarily fixed to the housing in the first step, but not completely secured. This preliminary fixation maintains limited mobility, allowing the valve seat to perform self-centering movements during the oscillation phase in the second step. The preliminary action of partial fixation enables both simplified assembly process and maintained self-centering capability, resolving the contradiction between device complexity and manufacturing precision.
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 method enables precise self-centering of the valve seat with respect to the valve needle, ensuring effective sealing performance by allowing the valve seat to center itself during the oscillating motion, thereby improving the assembly precision and sealing efficiency of needle valves.
Implementation Method 1
each valve needle (16) is set into an oscillating movement, in which it is alternately placed on the valve seat (26) assigned to it and lifted off therefrom
Data Source
Figure 1~2
AI summary
The invention relates to a method for assembling a needle valve (10) that comprises a housing (12), at least one valve needle (16), which is longitudinally displaceably guided in the housing (12) in a first spatial direction (14), and at least one valve seat plate (18), wherein the valve seat plate (18) for each valve needle (16) has a valve seat (26) associated with said valve needle, at which valve seat an outlet opening (28) for a fluid can be closed and opened by a back and forth movement of the relevant valve needle (16). According to the invention, in a first step the valve seat plate (18) is fastened to the housing (12) by fastening means (20) such that it can move in a limited manner with respect to the housing (12); in a second step each valve needle (16) is set into a back and forth movement in which it is alternatingly placed onto the valve seat (26) associated therewith and lifted up therefrom; and in a third step the valve seat plate (18) is fixed on the housing (20) while the at least one valve needle (16) moves back and forth.