Hydraulic Electrode Actuation for Compact High-Pressure Welding

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Solution Overview

Problem

Existing resistance welding apparatuses face challenges in applying high pressures efficiently due to structural complexity and bulkiness, leading to space occupation issues and reliability concerns, especially when high thrusts are required.

Innovation Solution

A welding apparatus utilizing a hydraulic pump-activated linear actuator with a closed circuit filled with oil, eliminating the need for complex pneumatic systems by integrating the actuation circuit within metallic blocks and using a symmetrical piston design to achieve high pressures with reduced space and structural complexity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Stress or pressure

If pneumatic systems are used to apply high pressure in welding apparatus, then high pressure can be achieved, but the structure becomes complex and bulky

Engineering Contradiction:
ImprovepressureVSAvoidstructural complexity
Core Design Contradiction:
Stress or pressureVSDevice complexity

Solution Approach 1:

The patent replaces the pneumatic system with a hydraulic system. The hydraulic cylinder (13) filled with incompressible fluid provides high pressure more efficiently than pneumatic systems, reducing the need for complex pressure multiplication mechanisms while maintaining the ability to generate high welding pressures.

Inventive Principle:
Principle #29Pneumatics and hydraulics

Solution Approach 2:

The patent replaces the mechanical linkage system with a direct hydraulic actuation system. The hydraulic cylinder directly drives the welding electrode without requiring complex mechanical transmission mechanisms, thereby simplifying the overall structure while maintaining high pressure capability.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

2Stress or pressure

If pneumatic systems are used to apply high pressure in welding apparatus, then high pressure can be achieved, but the apparatus occupies large space

Engineering Contradiction:
ImprovepressureVSAvoidspace occupation
Core Design Contradiction:
Stress or pressureVSVolume of moving object

Solution Approach 1:

The hydraulic system with incompressible fluid allows for more compact design compared to pneumatic systems. The hydraulic cylinder (13) can generate high pressure in a smaller volume, reducing the overall space occupation of the welding apparatus while maintaining high pressure capability.

Inventive Principle:
Principle #29Pneumatics and hydraulics

3Stress or pressure

If complex pneumatic structures are used for high pressure, then high pressure can be achieved, but reliability decreases and maintenance increases

Engineering Contradiction:
ImprovepressureVSAvoidoperational reliability
Core Design Contradiction:
Stress or pressureVSReliability

Solution Approach 1:

The hydraulic system with incompressible fluid provides more stable and reliable pressure generation compared to pneumatic systems. The hydraulic cylinder (13) maintains consistent pressure without the compressibility issues of gas, improving operational reliability and reducing maintenance requirements.

Inventive Principle:
Principle #29Pneumatics and hydraulics

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 apparatus effectively applies high thrusts and pressures with improved reliability and reduced space occupation, minimizing energy consumption and eliminating risks of contamination, while ensuring precise control and high cycle repeatability.

Implementation Method 1

a welding apparatus utilizing a hydraulic pump-activated linear actuator with a closed circuit filled with oil

Methodology Applied
Scientific EffectHydraulic pressure: Hydraulic Press

Implementation Method 2

said electric current causes the localized heating of the area of interest up to the melting of the material involved by Joule effect

Methodology Applied
Scientific EffectJoule effect: Joule Heating

Data Source

PatentEP3895836B1Welding apparatus
Publication Date: 2023.02.22 TECNA
  • EP3895836B1 patent drawingFigure 1
  • EP3895836B1 patent drawingFigure 2
  • EP3895836B1 patent drawingFigure 3

AI summary

The present application relates to a welding apparatus. The apparatus comprises a fixed supporting structure for an assembly (3) for the movement of at least one electrode, which can be crossed by current in order to perform welding treatments. The movement assembly (3) comprises a hydraulic pump (6) for the actuation of a linear hydraulic actuator, which comprises a hollow cylinder (7) which is rigidly supported by the structure and forms internally a compartment (7a) for the at least partial accommodation of a piston (8); the piston (8) supports even indirectly the electrode and can move with an alternating rectilinear motion in order to press the electrode against the parts to be welded. The actuator is activated by the pump (6) by means of a closed hydraulic actuation circuit, which is filled with a liquid and comprises the pump (6), the compartment (7a), a delivery duct (9) and an intake duct (10); the ducts (9, 10) are constituted respectively by one or more pairs of distinct intermediate channels (9a, 10a), which are substantially mutually parallel correspondingly inside one or more perforated blocks (11A, 11B, 11C) which are interposed between the pump (6) and the cylinder (7), and by a pair of distinct terminal channels (9b, 10b), which are substantially mutually parallel in the side wall (7b) of the cylinder (7) and lead to the compartment (7a).