Construction Machine Door Body Distortion Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The existing construction machines, such as hydraulic excavators, face issues with maintaining outer appearance beauty and increasing manufacturing costs due to the distortion caused by the gap between three-dimensional curved door bodies and flat reinforcing members during welding.
Innovation Solution
Incorporating an intermediate plate member with a thickness equal to or less than the door body between the door body and the reinforcing member, allowing for jointing through spot welding of the door body and intermediate plate member, and fillet welding of the intermediate and reinforcing members, which absorbs distortion and reduces manufacturing costs by eliminating the need for expensive press dies.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Shape
If the door body is press-formed into a three-dimensional curved surface configuration using a press die, then the outer appearance beauty is improved, but the manufacturing cost increases due to huge expenditures for the press die
Solution Approach 1:
The door is divided into two separate components: the door body (press-formed into three-dimensional curved surface) and the reinforcing member (formed by bending process). This segmentation allows each component to be manufactured using the most cost-effective process for its specific requirements, eliminating the need for an expensive press die while maintaining the curved surface appearance.
Solution Approach 2:
An intermediate plate member is introduced between the door body and the reinforcing member. This intermediary component facilitates the jointing of the two parts through spot welding and fillet welding, allowing the door body to maintain its three-dimensional curved shape without direct welding to the flat reinforcing member, thus preventing distortion.
2Ease of manufacture
If the reinforcing member is formed by bending process without press die to reduce manufacturing cost, then the manufacturing cost is reduced, but a slight gap is generated between the three-dimensional curved door body and the flat reinforcing member
Solution Approach 1:
The intermediate plate member serves as a mediator that fills and bridges the gap between the three-dimensional curved door body and the flat reinforcing member. By positioning this intermediate component between the two parts, the gap is eliminated and proper alignment is achieved, enabling effective welding without compromising manufacturing precision.
3Strength
If the reinforcing member is directly welded to the door body, then the joint strength is improved, but the door body is pulled toward the reinforcing member causing distortion and deteriorating outer appearance
Solution Approach 1:
The intermediate plate member acts as a buffer between the door body and reinforcing member during welding. It distributes and absorbs the welding forces, preventing the door body from being pulled toward the reinforcing member. This intermediary layer maintains the door body's three-dimensional curved shape while still achieving strong joint strength through spot welding and fillet welding.
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 configuration enhances the outer appearance beauty by preventing distortion in the door body and reduces manufacturing costs by using inexpensive reinforcing members without press dies, while maintaining the strength and aesthetic appeal of the housing cover.
Implementation Method 1
an intermediate plate member having a plate thickness equal to or less than that of the door body is provided between the door body and the reinforcing member
Implementation Method 2
the door body and the intermediate plate member are jointed by spot welding
Implementation Method 3
the intermediate plate member and the reinforcing member are jointed by fillet welding
Data Source
Figure 1
Figure 2
Figure 3
AI summary
An intermediate plate member (22) having a plate thickness equal to or less than that of a door body (19) is provided between the door body (19) and a reinforcing member (24) constituting a right side door (18). The door body (19) and the intermediate plate member (22) are jointed by spot welding, and the intermediate plate member (22) and the reinforcing member (24) are jointed by fillet welding, thereby jointing the reinforcing member (24) through the intermediate plate member (22) on the inner side surface (19A) of the door body (19). Thereby, at the time of jointing the door body (19) and the intermediate plate member (22) by welding, the intermediate plate member (22) having the strength lower than that of the door body (19) can be distorted by priority, thus restricting the generation of distortion in the door body (19) and keeping the outer appearance beauty of the right side door (18) in good conditions.