Capacity Control Valve Cap Structure for Precise Valve Seating
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The existing capacity control valve requires high suction pressure to open the CS communication passage due to a narrowed pressure receiving surface, which can lead to imprecise seating of the cap on the valve seat, influenced by the welding bead formed during assembly.
Innovation Solution
A capacity control valve design with a recessed portion on the outer peripheral end of the cap to house the welding bead, ensuring a larger pressure receiving surface and precise seating, while suppressing the influence of the welding bead on the valve operation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If the cap is welded to the bellows core, then the on-off valve element is sealed and structurally integrated, but the welding bead influences the seating precision of the cap on the valve seat
Solution Approach 1:
The patent applies the nesting principle by creating a recessed portion in the cap that houses the welding bead, effectively nesting the welding defect within a dedicated space. This allows the welding bead to be contained without interfering with the seating surface, resolving the contradiction between achieving strong welding and maintaining precise seating.
Solution Approach 2:
The patent applies local quality by differentiating the function of different regions of the cap: the outer peripheral end portion contains the recessed portion for housing the welding bead, while the inner diameter side maintains a flat seal face for precise seating on the valve seat. This localized functional differentiation allows both welding strength and seating precision to coexist.
2Speed
If the pressure receiving surface is enlarged to improve responsiveness, then the cap cannot be precisely seated on the valve seat due to welding bead interference
Solution Approach 1:
The recessed portion acts as a nested space that accommodates the welding bead, allowing the pressure receiving surface to extend to the outer peripheral end of the cap without compromising seating precision. The welding bead is nested within the recessed portion, separating it from the seating interface.
Solution Approach 2:
The cap is segmented into distinct functional zones: the recessed portion at the outer periphery houses the welding bead, the flat seal face on the inner diameter side ensures precise seating, and the pressure receiving surface extends across the available area. This segmentation allows each region to optimize its specific function without interfering with others.
3Manufacturing precision
If the recessed portion is formed on the cap to house the welding bead, then seating precision is improved, but the cap structure becomes more complex
Solution Approach 1:
The recessed portion is localized to the outer peripheral end of the cap, affecting only a small region while leaving the majority of the cap structure simple and flat. This localized modification minimizes the increase in structural complexity while achieving the goal of precise seating.
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
The solution allows for precise seating of the cap on the valve seat without being affected by the welding bead, ensuring a larger pressure receiving surface and improved operational reliability of the capacity control valve.
Implementation Method 1
a valve element is moved in the axial direction by electromagnetic force generated in a solenoid
Implementation Method 2
by contracting the bellows core and separating the cap of the on-off valve element from the valve seat by receiving suction pressure Ps in the CS communication passage
Data Source
Figure 1
Figure 2
Figure 3
AI summary
A capacity control valve not influenced by a welding bead while ensuring largeness of a pressure receiving surface of a cap is provided. A capacity control valve V includes a main valve 50 opens and closes communication between a discharge port 12 and a control port 14 formed in a valve housing 10 by movement of a rod 83 to be driven by a solenoid 80, a CS communication passage 55 providing communication between a control fluid supply chamber 60 formed in the valve housing 10 and a suction port 13, and an on-off valve 54 formed by a communication passage forming member 52 having an annular valve seat 52a in an outer periphery of the CS communication passage 55 and an on-off valve element 61 biased in the valve closing direction with respect to the valve seat 52a. The on-off valve element 61 includes a cap 70 configured for seating on and separating from the valve seat 52a, and a bellows core 62 welded to an outer peripheral end portion 70d of the cap 70, and a recessed portion 70e that houses a welding bead WB is provided in the outer peripheral end portion 70d of the cap 70.