Hydraulic Partial-Piston Pressing Structure for Multi-Stage Compression

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Solution Overview

Problem

Existing hydraulically actuated hand-held devices face challenges in multi-stage pressing due to complex designs, large first partial pistons, and incomplete retraction issues, which complicate maintenance and efficiency during workpiece changes.

Innovation Solution

A simplified design where the piston rod has a single total impact area encompassing all partial impact areas, with all partial pistons subjected to hydraulic pressure, and a single return spring resetting all pistons, allowing the piston rod to be extended from the hydraulic cylinder, enabling easier maintenance and immediate next-stage pressing without full retraction.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Force

If the first partial piston passes through the hydraulic cylinder and acts on the piston rod outside the hydraulic cylinder, then the pressing force can be applied externally, but the device complexity increases and maintenance becomes difficult

Engineering Contradiction:
Improvepressing forceVSAvoiddevice complexity
Core Design Contradiction:
ForceVSDevice complexity

Solution Approach 1:

The patent merges the action surfaces of all partial pistons onto a single piston rod that remains entirely within the hydraulic cylinder. This consolidation eliminates the need for external piston rod extensions and complex sealing arrangements, thereby reducing device complexity while maintaining the ability to apply pressing force through the unified piston rod structure.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The single piston rod serves as a universal actuation element for all partial pistons, replacing the need for separate piston rods for each partial piston. This multi-functional design simplifies the overall structure, reduces the number of components, and facilitates easier maintenance while still enabling all partial pistons to contribute to the pressing force.

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

2Stress or pressure

If the first partial piston is relatively large to accommodate the hydraulic cylinder passage, then the hydraulic medium can act on it effectively, but the device volume increases

Engineering Contradiction:
Improvehydraulic pressure transmissionVSAvoiddevice volume
Core Design Contradiction:
Stress or pressureVSVolume of stationary object

Solution Approach 1:

The patent employs a nested arrangement where multiple partial pistons are positioned concentrically within the hydraulic cylinder, with each subsequent partial piston having a smaller effective area than the previous one. This nesting allows all partial pistons to be accommodated within the same cylindrical space, maximizing pressure transmission efficiency without increasing the overall device volume.

Inventive Principle:
Principle #7Nested doll (Nesting)

3Loss of energy

If the first partial piston is always retracted with priority after pressing, then the hydraulic fluid can flow out efficiently, but the productivity decreases due to required complete retraction before next workpiece

Engineering Contradiction:
Improvehydraulic fluid flowVSAvoidproductivity
Core Design Contradiction:
Loss of energyVSProductivity

Solution Approach 1:

The patent implements dynamic control of partial piston retraction through independent control valves for each partial piston. This allows the system to adapt the retraction sequence and timing based on operational requirements, enabling partial retraction configurations that maintain hydraulic efficiency while minimizing idle time between workpieces, thereby improving productivity.

Inventive Principle:
Principle #15Dynamics

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 ease of maintenance, allows for efficient multi-stage pressing, and prevents the need for complete retraction of pistons, enabling continuous operation with reduced downtime between workpieces.

Implementation Method 1

the partial pistons are movable in a travel direction in the hydraulic cylinder under pressure from a hydraulic medium

Methodology Applied
Scientific EffectHydraulic pressure: Hydraulic Press

Implementation Method 2

a return spring is mounted in the hydraulic cylinder, wherein the partial pistons are movable in the direction of travel in the hydraulic cylinder under pressure of hydraulic fluid against the force of the return spring

Methodology Applied
Scientific EffectElastic force: Spring

Data Source

PatentEP4226050B1Handheld hydraulic actuated working device
Publication Date: 2024.11.20 GUSTAV KLAUKE GMBH
  • EP4226050B1 patent drawingFigure 1~2
  • EP4226050B1 patent drawingFigure 3
  • EP4226050B1 patent drawingFigure 4

AI summary

The invention relates to a hydraulically actuatable work device (1), designed to perform a work operation, having a hydraulic cylinder (6) and having at least a first and a second partial piston (9, 10), provided in the hydraulic cylinder (6), wherein: the partial pistons (9, 10) can be displaced in the hydraulic cylinder (6) in a displacement direction (V) under pressure applied by a hydraulic medium in order to perform the work operation; each partial piston (9, 10) has at the lower end thereof an action surface (17, 18) against which the hydraulic medium can act; the same hydraulic pressure in each case continues to be applied to the action surfaces of the partial pistons (9, 10) throughout the entire work operation; also provided is a piston rod (11) which is coupled to the hydraulic cylinder (6); the piston rod (11) has at the lower end thereof an impingement surface (18) against which the partial pistons (9, 10) can act; the piston rod (11) is also provided separate from the partial pistons (9, 10) and can be impinged upon by only one partial piston (9, 10), by more than one partial piston or by all the partial pistons (9, 10) at the same time; in the hydraulic cylinder (6) there is attached a restoring spring; the partial pistons (9, 10) can be moved against the force of the restoring spring (22) in the hydraulic cylinder (6) in the displacement direction (V) under pressure applied by hydraulic fluid; a work part (13) is also provided which is coupled to the piston rod (11) and thus can be moved, and the partial pistons (9, 10) are designed to act on the same work part (13). To specify a hydraulically actuatable work device (1) which, with a simple design, enables effective and advantageous multi-stage compression, according to the invention the impingement surface (18) forms a first partial impingement surface against which the first partial piston (9) is designed to act, and a second partial impingement surface against which the second partial piston (10) is designed to act, wherein the first and the second partial impingement surfaces do not overlap with each other in a direction perpendicular to the displacement direction.