Projection Bolt Welding Apparatus with Optical Sensor Timing

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Solution Overview

Problem

Existing welding technologies for projection bolts to steel plates face challenges in synchronizing the electrode's advancement with other moving members, leading to inaccuracies and inefficiencies, particularly when distances between welding points vary, and rely on mechanically movable sensors that are prone to displacement and maintenance issues.

Innovation Solution

A method and apparatus that utilize a timer unit to coordinate the electrode's advancement based on the projection bolt's insertion into the receiving hole and the alignment of the welding point, applying an air blast at precise timing to ensure accurate and efficient welding, while minimizing the use of mechanically movable sensor components.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If mechanically movable sensor components such as limit switches are used to accurately move the holding head a short distance at high speed, then the holding head can be positioned precisely, but the sensor components are prone to displacement, wear, and require frequent replacement and adjustment

Engineering Contradiction:
Improvepositioning accuracy of holding headVSAvoidreliability of sensor components
Core Design Contradiction:
Measurement precisionVSReliability

Solution Approach 1:

The patent replaces mechanically movable sensor components with a non-contact optical sensor system. The optical sensor detects the position of the holding head and feed rod without physical contact, eliminating wear and displacement issues associated with mechanical sensors while maintaining positioning accuracy.

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

Solution Approach 2:

The patent introduces an optical field as an intermediary between the sensor and the moving components. The optical sensor detects position information through light reflection or interruption, using the optical field as a mediator to transmit position data without mechanical contact.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Ease of operation

If the electrode advancement action is not organically linked to the actions of other moving members, then the system is simpler to control, but the welding timing and electrode position synchronization are inaccurate

Engineering Contradiction:
Improveease of controlVSAvoidwelding timing accuracy
Core Design Contradiction:
Ease of operationVSManufacturing precision

Solution Approach 1:

The patent implements a feedback control system where optical sensors continuously monitor the positions of the holding head and feed rod, and the control unit adjusts the electrode advancement timing based on this real-time position information. This ensures accurate synchronization without overly complex control mechanisms.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The patent uses preliminary action by detecting the position of the holding head and feed rod before electrode advancement begins, allowing the control unit to pre-calculate and prepare the appropriate advancement timing, ensuring synchronized welding action.

Inventive Principle:
Principle #10Preliminary action

3Adaptability or versatility

If the distances between welding points vary, then the welding apparatus can handle different workpiece configurations, but the advancing timing of the electrode must be changed according to different distances

Engineering Contradiction:
Improveadaptability to different welding point distancesVSAvoidcomplexity of timing control
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent employs dynamic timing adjustment where the electrode advancement timing is not fixed but is continuously adjusted based on real-time detection of holding head and feed rod positions. This dynamic adaptation allows the system to handle varying distances between welding points without requiring manual reconfiguration or complex preset timing mechanisms.

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 approach prevents misfeeding of the projection bolt, ensures reliable electrode advancement despite variations in welding point alignment, reduces overall welding time by overlapping bolt insertion and steel plate movement, and eliminates the need for precise mechanical sensors, enhancing operational efficiency and reducing maintenance.

Implementation Method 1

subsequently applying an air blast to complete the insertion

Methodology Applied
Scientific EffectAir blast: Jet

Implementation Method 2

welding of a projection bolt to a steel plate part by electric resistance welding

Methodology Applied
Scientific EffectElectric resistance welding: Joule Heating

Data Source

PatentEP2133168B1Projection bolt welding method, and welding apparatus
Publication Date: 2016.06.01 KUBUSHIKI KAISHA AOYAMA
  • EP2133168B1 patent drawingFigure 1A~1B
  • EP2133168B1 patent drawingFigure 2A~3B
  • EP2133168B1 patent drawingFigure 4

AI summary

Provided are a welding method and a welding apparatus capable of appropriately starting the advancement of an electrode based on the positioning of a welding point on a steel plate part to which a projection bolt is to be welded and on the state of completion of feeding of the projection bolt to the electrode. A bolt (10) held by a feed rod (17) is inserted into a receiving hole (20) of an electrode (6), and an air blast is applied from a holding head (18) to complete the insertion of the bolt into the receiving hole(20). Then, the feed rod (17) is retracted. Subsequently, the electrode (6) is advanced to weld the bolt to a steel plate part (30) by electric resistance welding. In this case, the electrode (6) is advanced toward the steel plate part (30) in response to a signal generated upon insertion of the bolt and a signal generated after a welding point on the steel plate part (30) is adjusted. Subsequently, pressurization and energization are carried out.