Washing Machine Front Door Welding with Notch-Based Alignment

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Solution Overview

Problem

Existing washing machines face challenges in achieving precise fitting and strong welding between the door frame and frame cover, which affects the structural integrity and aesthetic appeal of the front door.

Innovation Solution

The implementation of notches and placement portions on the welding lines between the door frame and frame cover, along with fixation tabs and L-shaped welding portions, enhances the welding strength and contact surface, ensuring a secure and aesthetically pleasing connection through ultrasonic welding.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If conventional welding connection is used between door frame and frame cover, then manufacturing process is simple, but welding strength and fitting precision are insufficient

Engineering Contradiction:
Improvewelding strengthVSAvoidstructure complexity
Core Design Contradiction:
StrengthVSDevice complexity

Solution Approach 1:

The welding line is segmented into multiple sections by introducing notches that divide the continuous welding line into discrete welding sections. This segmentation allows for more precise welding control and improved welding strength at each section while maintaining overall structural integrity.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Notches are strategically positioned at specific locations along the welding line where enhanced welding strength is needed. The notches create local variations in the welding structure, concentrating welding energy and improving bond strength at critical areas without requiring complex changes to the entire structure.

Inventive Principle:
Principle #3Local quality

2Manufacturing precision

If conventional welding line is used between door frame and frame cover, then manufacturing is simple, but fitting precision is poor

Engineering Contradiction:
Improvefitting precisionVSAvoidmanufacturing complexity
Core Design Contradiction:
Manufacturing precisionVSEase of manufacture

Solution Approach 1:

Notches are pre-formed on the welding surfaces of both the door frame and frame cover before the welding process. This preliminary action ensures precise alignment and positioning of the components, improving fitting precision while simplifying the actual welding operation by providing predetermined welding locations.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The mechanical alignment and fitting process is enhanced by the notched structure, which provides self-aligning features that guide the components into precise positions during assembly, reducing the need for complex mechanical adjustment mechanisms.

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

3Strength

If welding portions slide during welding process, then welding strength decreases, but preventing sliding increases structure complexity

Engineering Contradiction:
Improvewelding strengthVSAvoidfixation structure complexity
Core Design Contradiction:
StrengthVSDevice complexity

Solution Approach 1:

The notched structure on the welding surfaces provides self-fixation during the welding process. The interlocking notches automatically prevent sliding between the door frame and frame cover without requiring additional external fixation devices, maintaining welding strength while avoiding increased structural complexity.

Inventive Principle:
Principle #25Self-service

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 solution improves the fitting precision and welding strength between the door frame and frame cover, preventing sliding during the welding process and allowing for the integration of a door glass, resulting in a more robust and visually appealing front door.

Implementation Method 1

a door frame (11) and a frame cover (14) connected to each other by means of welding

Methodology Applied
Scientific EffectWelding: Welding

Implementation Method 2

The welding portions, provided on the inner edge side, are provided in L form in an opposite manner with respect to each other. Thus, the edge line on the welding portion is expanded.

Methodology Applied
Scientific EffectUltrasonic welding: Ultrasonic Vibration

Data Source

PatentEP2938773B1A washing machine having a front door
Publication Date: 2017.06.07 BSH HAUSGERATE GMBH
  • EP2938773B1 patent drawingFigure 1
  • EP2938773B1 patent drawingFigure 2
  • EP2938773B1 patent drawingFigure 3a~3b

AI summary

The present invention relates to a washing machine having a drum (20) wherein laundry to be washed is to be disposed, a loading opening (30) through which laundry can be loaded to the drum (20), a front door (10) closing the loading opening (30) and having a frame cover (4) and a door frame (11) connected to the frame cover (14) by means of welding, and each of the frame cover (14) and the door frame (11) having respective welding lines (122, 132, 52, 162) on at least one portion of a side facing a respective other of the frame cover (14) and the door frame (11). The frame cover (14) and the door frame (11) comprise at least one notch (123, 133, 153, 163) provided on one of the welding lines (122, 132, 152, 162), and at least one placement portion (124, 134, 154, 164) on another of the welding lines (122, 132, 52, 162) for mating the notch (123, 133, 153, 163), with the notch (123, 133, 153, 163) disposed in the placement portion (124, 134, 154, 164).