Flow Switching Valve Assembly Using Rotated Ball and Relaxed Seals

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Solution Overview

Problem

Existing flow channel switching valves face challenges in assembly precision due to difficulties in inserting the ball valve member between seat members and compressing sealing members, often resulting in inclined seat member installation.

Innovation Solution

A flow channel switching valve design featuring a valve body with integral flow channels, a ball valve member with a switching flow channel, and a pair of seat members that support the valve member, along with a sealing member and a rotation driving section. The valve member has a smaller size in the direction of the rotation axis, allowing for a compressed sealing member state during assembly and a restoration state during assembly posture, facilitated by jig mounting portions for precise rotation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If the ball valve member is directly supported by the valve case or interposed between seat members with compressed sealing members, then the valve can be assembled, but assembly precision deteriorates and seat members become inclined

Engineering Contradiction:
Improveassembly precisionVSAvoidassembly complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The valve member is pre-positioned in a specific rotational orientation within the valve chamber before final assembly. The rotation driving section is pre-installed to enable controlled rotation during assembly, allowing the valve member to be initially positioned with correct orientation before the sealing members are compressed into place. This preliminary positioning prevents the seat members from becoming inclined during assembly.

Inventive Principle:
Principle #10Preliminary action

2Reliability

If sealing members are compressed during assembly, then sealing performance can be ensured, but it becomes difficult to insert members into the valve chamber

Engineering Contradiction:
Improvesealing performanceVSAvoidease of assembly
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The sealing members are designed with elastic properties that allow them to dynamically change their compression state during assembly. During the insertion phase, the sealing members remain in a relaxed, uncompressed state to facilitate easy insertion of the valve member and seat members into the valve chamber. Once assembly is complete, the sealing members are compressed to their operational state to ensure sealing performance. This dynamic transition between relaxed and compressed states resolves the contradiction between ease of assembly and sealing performance.

Inventive Principle:
Principle #15Dynamics

Data Source

PatentEP3825587B1Flow passage switching valve and assembly method therefor
Publication Date: 2025.02.12 FUJIKOKI CORP
  • EP3825587B1 patent drawingFigure 1
  • EP3825587B1 patent drawingFigure 2
  • EP3825587B1 patent drawingFigure 3

AI summary

A flow channel switching valve that enables assembly precision to be effectively increased and a method for assembling the flow channel switching valve are provided. The size (H) of a ball valve member (20) of a flow channel switching valve (1) in the direction of a rotation axis (L) is smaller than the size (W) thereof in the direction perpendicular to the rotation axis (L) such that sealing members (31, 31) are in a restoration state when the ball valve member (20) has an assembly posture, and such that the sealing members (31, 31) are in a compressed state when the ball valve member (20) has a support posture. When the flow channel switching valve (1) is assembled, seat members (30, 30) and the sealing members (31, 31) are installed in a valve chamber (14), and the ball valve member (20) is disposed between the seat members (30, 30) so as to have the assembly posture. A rod-shaped jig is inserted through a second flow channel (12) of a valve body (10), and a tip end portion thereof and a recessed portion (27a) of a jig mounting portion (27) of the ball valve member (20) are fit together. The rod-shaped jig is rotated, and the ball valve member (20) is rotated from the assembly posture into the support posture.