Casting Plunger Valve Design for Melt Flow Control

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Conventional casting pistons and units face challenges in the design and functionality of shut-off valves, particularly in ensuring efficient melt material flow and preventing backflow, especially during melt suction and mold filling processes.

Innovation Solution

The casting piston features a piston sleeve with a valve seat and a piston tappet containing a valve body, allowing for defined opening and closing of the valve, while the riser channel shut-off valve has a cylindrical valve body with axial passage openings and a stop ring, optimizing melt flow and pressure conditions to maintain the valve open under low melt volume, reducing back pressure and promoting material compaction.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a conventional non-return valve is used in the casting piston and riser channel, then the valve structure is simple, but the valve behavior is inadequate under low melt volume conditions, causing backflow prevention issues and poor material compaction

Engineering Contradiction:
Improvevalve behaviorVSAvoidvalve structure
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The casting piston is divided into multiple functional segments: a piston sleeve containing the valve seat, a piston tappet with the valve body, and axial grooves for melt flow distribution. This segmentation allows each component to be optimized for its specific function, improving valve reliability while maintaining manageable complexity through modular design

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The valve body is nested within the piston tappet, which itself is positioned within the casting piston assembly. The piston sleeve contains the valve seat and surrounds the valve body. This nested arrangement allows the valve mechanism to be integrated compactly within the piston structure, achieving improved valve behavior without proportionally increasing overall device complexity

Inventive Principle:
Principle #7Nested doll (Nesting)

2Productivity

If the valve body is designed with axial passage openings and stop ring, then melt flow efficiency is improved and back pressure is minimized, but the valve body design becomes more complex

Engineering Contradiction:
Improvemelt flow efficiencyVSAvoidvalve body design
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The valve body is designed with non-uniform local characteristics: axial passage openings are positioned at specific locations to optimize melt flow paths, and the stop ring is placed at a specific axial position to control valve lift. This local optimization of structure and flow paths improves melt flow efficiency and reduces back pressure while keeping the overall valve body design relatively simple

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The valve body incorporates axial passage openings that create three-dimensional flow paths through the valve structure. The stop ring adds an axial dimension constraint to the valve body movement, controlling the opening distance. This multi-dimensional design approach optimizes melt flow characteristics and pressure distribution without requiring overly complex valve geometry

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

3Manufacturing precision

If the piston sleeve and piston tappet are spaced to allow defined valve opening/closing, then valve control precision is improved, but the clearance requirements increase the complexity of sealing and positioning

Engineering Contradiction:
Improvevalve control precisionVSAvoidsealing and positioning
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The piston sleeve and piston tappet are spaced to allow the valve mechanism to self-regulate its opening and closing through the interaction of melt pressure and the defined clearance. The axial grooves in the piston tappet guide melt flow that naturally acts on the valve body to control its position. This self-service approach improves valve control precision while minimizing the need for complex external sealing and positioning mechanisms

Inventive Principle:
Principle #25Self-service

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 enhances the valve behavior by minimizing back pressure and ensuring efficient melt flow, even under low melt volume conditions, and maintains the valve open to facilitate material compaction during solidification, improving the overall functionality of the casting unit.

Implementation Method 1

a piston tappet (12) which contains a valve body (13) and interacts with the valve seat (11)

Methodology Applied
Scientific EffectMechanical Force: Mechanical Force

Implementation Method 2

a casting piston (3) arranged in an axially movable manner in a casting cylinder (2)

Methodology Applied
Scientific EffectPressure Gradient: Pressure Gradient

Implementation Method 3

The second tappet part (12b) includes a piston sleeve driver stop (74)

Methodology Applied
Scientific EffectMechanical Force: Mechanical Force

Data Source

PatentEP2701866B1Casting plunger and casting unit with shut-off valve
Publication Date: 2018.11.14 OSKAR FRECH GMBH CO KG
  • EP2701866B1 patent drawingFigure 1
  • EP2701866B1 patent drawingFigure 2
  • EP2701866B1 patent drawingFigure 3~5

AI summary

The invention relates to a casting plunger (3) with an integrated shut-off valve (7) and to a casting unit for a casting machine having a casting vessel (1), wherein the casting unit comprises a casting plunger, which is arranged axially movably in a casting cylinder of the casting vessel and/or a standpipe shut-off valve (8) in a standpipe (4) of the casting vessel. A casting plunger according to the invention has a plunger sleeve (9), which can be brought to bear against an inner wall (10) of a casting cylinder (2) of the casting unit and comprises a valve seat (11) for the integrated shut-off valve, and has a plunger ram (12), which comprises an associated valve body (13), wherein the plunger sleeve and the plunger ram are movable axially with respect to each other by a predeterminable valve stroke. A casting unit according to the invention has such a casting plunger and/or a standpipe shut-off valve (8) with a special valve body (20) through which molten material can flow. Use for example for hot-chamber pressure diecasting machines. Figure 1.