Concentric Synchronizing Cylinder With Bypass Flow for Low-Loss Stroke Motion

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Solution Overview

Problem

Existing forming devices, such as strand press and ring rolling systems, face inefficiencies due to high flow losses and mechanical friction in hydraulic cylinders, particularly in equalizing cylinders with two guided piston rods and pistons, which hinder quick and energy-efficient operation between different configurations.

Innovation Solution

A compact and durable equalizing cylinder design featuring a concentric arrangement of an outer and inner cylinder with a double-acting work piston, bypass valves, and an annular gap or bypass line, allowing fluid communication between pressure chambers to reduce flow losses and mechanical friction, enabling efficient and fast movement with a third-party drive.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If synchronous cylinders with two guided piston rods and pistons are used, then the cylinder can be switched from drag to working mode over the entire stroke, but high mechanical friction forces and flow losses occur

Engineering Contradiction:
Improvemode switching capabilityVSAvoidflow losses and friction
Core Design Contradiction:
Adaptability or versatilityVSLoss of energy

Solution Approach 1:

The invention extracts the bypass function from the main hydraulic circuit by introducing a separate bypass line with a bypass valve. This allows the main cylinder to focus on force generation while the bypass circuit handles the mode switching function, separating the conflicting requirements of adaptability and energy efficiency.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The bypass valve acts as an intermediary element that mediates between the two operating modes. By controlling the bypass flow, it enables smooth transitions between drag mode and working mode without requiring the main cylinder to directly handle both functions simultaneously, reducing energy losses.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Ease of operation

If hydraulic cylinders with large strokes are used for moving the ingot holder, then the holder can be positioned between ingot change position and working position, but the system becomes less efficient due to internal friction and flow losses

Engineering Contradiction:
Improveholder positioning capabilityVSAvoidenergy efficiency
Core Design Contradiction:
Ease of operationVSUse of energy by moving object

Solution Approach 1:

The invention introduces dynamic control of the hydraulic circuit through the bypass valve, which can adjust the flow path based on the operational requirements. During positioning operations, the bypass can be activated to reduce resistance and improve movement efficiency, while during force application, the bypass closes to maximize cylinder performance.

Inventive Principle:
Principle #15Dynamics

3Use of energy by moving object

If electric motors are used to move the holder, then internal forces in hydraulic cylinders must be overcome, but this adds complexity to the drive system

Engineering Contradiction:
Improveenergy efficiencyVSAvoiddrive system complexity
Core Design Contradiction:
Use of energy by moving objectVSDevice complexity

Solution Approach 1:

The hydraulic cylinder is designed to perform multiple functions: it can operate in drag mode for efficient positioning movements and in working mode for force application. The bypass device enables this multi-functionality, allowing the same hydraulic system to serve both positioning and forming operations without requiring separate electric motors.

Inventive Principle:
Principle #6Universality (Multi-functionality)

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 equalizing cylinder achieves energy-saving and rapid movement over the entire stroke, reducing flow losses and inner friction, allowing the system to develop full design force in each position, thus enhancing operational efficiency in forming devices like extrusion and ring rolling systems.

Implementation Method 1

a fluid connection between the two pressure chambers is established via the annular gap and/or the at least one bypass line

Methodology Applied
Scientific EffectHydraulic fluid flow: Hydraulic Press

Data Source

PatentEP3417178B1Double acting double rod cylinder for an extrusion press
Publication Date: 2021.04.14 SMS GROUP GMBH
  • EP3417178B1 patent drawingFigure 1
  • EP3417178B1 patent drawingFigure 2
  • EP3417178B1 patent drawingFigure 3

AI summary

The invention relates to a synchronizing cylinder (1), preferably for an extrusion plant, comprising an outer cylinder (10), an inner cylinder (20) accommodated therein and arranged concentrically thereto, a double-acting working piston (41) that is displaceably provided in the inner cylinder, and a bypass device (50) having a bypass valve (52). The working piston (41) subdivides the inner cylinder (20) into two pressure chambers (42) and can be acted upon by both pressure chambers (42) with a hydraulic fluid. The bypass device (50) is designed such that in a bypass position of the bypass valve (52), a fluid connection between the two pressure chambers (42) is established via a direct connection, preferably at least one bypass line, and in a working position of the bypass valve (52), no such fluid connection exists.