Multi-Part Mold Core for Thin-Walled Concrete Pipe Liners

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Solution Overview

Problem

Existing methods for producing concrete pipes with thin-walled plastic inner pipes are inefficient and costly, as they require complex and expensive expanding cores for stabilization, and the widening sections at the ends of the pipes are prone to deformation and leakage during concrete pouring.

Innovation Solution

A multi-part mold core is designed to match the shape of the plastic inner pipe, including sections for the inner and widened areas, which prevents concrete penetration and stabilizes the pipe ends, allowing for the use of thin-walled pipes and eliminating the need for additional sealing means.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If a multi-part mold core is used to match the shape of the plastic inner pipe, then manufacturing precision and reliability are improved, but device complexity increases

Engineering Contradiction:
Improvefitting precision of pipe endsVSAvoidmold core structure
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The mold core is divided into multiple parts: a first mold core part with a first outer section matching the expanded cross-section of pipe ends, and a second mold core part with a second outer section matching the smaller cross-section of the pipe middle section. This segmentation allows each part to be precisely shaped for its specific location, improving overall manufacturing precision while keeping individual parts manageable in complexity.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Different sections of the mold core have different cross-sectional dimensions tailored to the local geometry of the plastic inner pipe. The first outer section has a larger cross-section for the expanded pipe ends, while the second outer section has a smaller cross-section for the pipe middle, ensuring precise local fitting throughout the pipe structure.

Inventive Principle:
Principle #3Local quality

2Loss of substance

If thin-walled plastic inner pipes are used, then material cost and weight are reduced, but stability during concrete pouring deteriorates

Engineering Contradiction:
Improveplastic material consumptionVSAvoidpipe stability during pouring
Core Design Contradiction:
Loss of substanceVSStability of the object's composition

Solution Approach 1:

The mold core parts are inserted into the thin-walled plastic inner pipe before concrete pouring to provide preliminary stabilization. The first mold core part stabilizes the expanded pipe ends, while the second mold core part stabilizes the pipe middle section, preventing deformation during the concrete pouring process.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The mold core acts as an intermediary support structure between the thin-walled plastic inner pipe and the concrete base body. It provides the necessary mechanical support during pouring without becoming part of the final pipe structure, as it is removed after concrete hardening.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Adaptability or versatility

If expanding sections are provided at pipe ends for assembly, then adaptability and ease of operation are improved, but susceptibility to concrete penetration and leakage increases

Engineering Contradiction:
Improveassembly compatibilityVSAvoidconcrete penetration and leakage
Core Design Contradiction:
Adaptability or versatilityVSObject-affected harmful factors

Solution Approach 1:

The first outer section of the mold core is designed to match the expanded cross-section of the pipe ends and provides preliminary sealing action before concrete pouring. This prevents concrete from penetrating into the expanding sections during the pouring process, while still maintaining the expanded geometry needed for assembly compatibility.

Inventive Principle:
Principle #9Preliminary anti-action

Data Source

PatentEP2504138B1Method and mould for producing concrete pipes having a plastic inner pipe
Publication Date: 2023.06.14 SCHLUSSELBAUER JOHANN
  • EP2504138B1 patent drawingFigure 1~2
  • EP2504138B1 patent drawingFigure 3~5
  • EP2504138B1 patent drawingFigure 6A~8B

AI summary

The invention relates to a method and a mould for producing a concrete pipe (1) which comprises a basic body (2) made of concrete and a plastic inner pipe (3) and which is intended for conducting a liquid. The method comprises the steps of introducing a mould core (4) into the plastic inner pipe (3), introducing the plastic inner pipe (3) into an outer mould (5) and pouring concrete into an intermediate space between the outer mould (5) and plastic inner pipe (3) in order to form the basic body (2), wherein, after the concrete has solidified, the plastic inner pipe (3) remains as inner formwork in the basic body (2) made of concrete and the mould body (4) is removed after the concrete has solidified, and wherein the plastic inner pipe (3) comprises an inner section (3c) and, at both ends, respective widened sections (3a, 3b) which have a larger cross section than the inner section (3c). According to the invention, the mould core (4) is adapted to the shape of the plastic inner pipe (3) in such a way that an inner section of the mould core (4) substantially has a cross section corresponding to the cross section of the inner section (3c) of the plastic inner pipe (3), and the outer sections of the mould core (4) substantially have a cross section corresponding to the cross sections of the widened sections (3a, 3b) at the ends of the plastic inner pipe (3). The mould core (4) is formed in at least two parts.