Plastic Radiator Cap Valve Seat Structure for Stable Sealing

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Solution Overview

Problem

Existing radiator caps for automobiles suffer from unstable sealing due to the unrestrained movement of the valve seat, leading to potential leakage and spillover, and require metal surface treatment that can cause environmental pollution.

Innovation Solution

A radiator cap design featuring a top cover unit, intermediate seat unit, and input/output valve units made of plastic materials, with integrated reinforcing structures and movable hook portions to ensure stable sealing and reduce environmental impact.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If the valve seat is connected to the upper cover only by the first spring, then the structure is simple, but the valve seat becomes unrestrained and movable, causing unstable sealing

Engineering Contradiction:
Improvestructure simplicityVSAvoidsealing stability
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The valve seat connection structure is segmented into multiple independent restraining elements (first spring, second spring, and positioning protrusions) that work together to provide stable sealing while maintaining structural simplicity

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The positioning protrusions on the valve seat are pre-designed to engage with corresponding positioning structures on the upper cover, establishing preliminary constraints before the radiator cap is installed, preventing unrestrained movement

Inventive Principle:
Principle #10Preliminary action

2Strength

If the upper cover is made of metal material, then the strength is high, but surface treatment is required which causes environmental pollution

Engineering Contradiction:
Improveupper cover strengthVSAvoidenvironmental pollution
Core Design Contradiction:
StrengthVSObject-generated harmful factors

Solution Approach 1:

The upper cover is made of plastic material instead of metal, eliminating the need for surface treatment and associated environmental pollution, while maintaining sufficient strength through optimized design

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

Solution Approach 2:

The material of the upper cover is changed from metal to plastic, fundamentally altering the material parameters to eliminate the need for surface treatment while maintaining structural integrity

Inventive Principle:
Principle #35Parameter changes

3Adaptability or versatility

If the valve seat is unrestrainedly movable relative to the upper cover, then the structure is flexible, but the valve seat may be easily skewed, resulting in inaccurate closing and unsatisfactory sealing

Engineering Contradiction:
Improvemovement flexibilityVSAvoidclosing accuracy
Core Design Contradiction:
Adaptability or versatilityVSManufacturing precision

Solution Approach 1:

Positioning protrusions with asymmetric geometries are designed to engage with corresponding asymmetric positioning structures, ensuring accurate alignment and preventing skewed positioning of the valve seat relative to the upper cover

Inventive Principle:
Principle #4Asymmetry

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 new design provides stable sealing and reduces manufacturing costs and environmental pollution by using plastic components, enhancing structural integrity and ease of assembly.

Implementation Method 1

the first spring is caused to generate a spring force. When the liquids are depressurized, the spring force of the first spring restores the valve seat

Methodology Applied
Scientific EffectSpring force: Spring

Implementation Method 2

the second spring generates a spring force. As long as an attraction force applied on the pin rod is smaller than the spring force of the second spring, the spring force of the second spring restores the pin rod

Methodology Applied
Scientific EffectSpring force: Spring

Data Source

PatentEP4656854A1Radiator cap
Publication Date: 2025.12.03 COPLUS
  • EP4656854A1 patent drawingFigure 1
  • EP4656854A1 patent drawingFigure 2
  • EP4656854A1 patent drawingFigure 3

AI summary

A radiator cap includes a top cover unit (1), an intermediate seat unit (2), an output valve unit (3), and an input valve unit (4). The top cover unit (1) includes a stem (12). A washer (16) surrounds the stem (12). The intermediate seat unit (2) includes a connecting seat (22). The output valve unit (3) includes a valve seat (31) connected to the connecting seat (22). The valve seat (31) has hook portions engaged with guiding recesses (224) of the connecting seat (22). A valve disc (33) is connected to the valve seat (31). A first spring (35) is disposed between the valve seat (31) and the connecting seat (22). The input valve unit (4) includes a pin rod (41), and a second spring (42) to bias the pin rod (41) to thereby abut against the valve disc (33) so as to close a valve hole (314).