Joined Body Groove Insertion Press-Fitting Damage Prevention
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Solution Overview
Problem
Existing joined bodies that rely on press-fitting to regulate relative movement between members often require increased diameter and restoring force, which can lead to damage during the press-fitting process, especially when the cylindrical member attempts to return to its original shape.
Innovation Solution
A joined body design featuring a groove portion and an insertion portion on one member, and an engagement portion on the other, which allows for reliable press-fitting and rotation regulation without relying solely on the restoring force, thereby preventing damage and misalignment.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If the press-fitted margin of the cylindrical member is increased to achieve higher joined force, then the joined force between the main body and the cylindrical member is increased, but the cylindrical member is possibly damaged by press-fitting
Solution Approach 1:
The invention divides the joining function into two independent parts: (1) the press-fitted cylindrical member provides joined force through radial expansion in the hole, and (2) the separate inclined surface provides rotational regulation through engagement with the inner edge portion. This segmentation allows each part to be optimized independently, so the cylindrical member does not need to be oversized for rotation control, reducing press-fitting damage risk while maintaining adequate joined force.
Solution Approach 2:
The inclined surface acts as an intermediary element between the cylindrical member and the main body's inner edge portion. It mediates the rotational regulation function, allowing the cylindrical member to focus on providing joined force through press-fitting without needing to be directly engaged for rotation control, thereby reducing the press-fitted margin required and preventing damage.
2Stability of the object's composition
If the diameter of the cylindrical member is increased to regulate relative movement, then the joined force is increased, but the device complexity and member size increase
Solution Approach 1:
The invention segments the functional responsibilities: the cylindrical member's primary function is to provide joined force through press-fitting, while the inclined surface (a separate structural feature) handles rotational regulation. This allows the cylindrical member to maintain a smaller, optimized diameter for its press-fitting function without needing to be oversized for rotation control, reducing overall device complexity and member size.
Solution Approach 2:
The inclined surface introduces a new dimensional aspect (angular/rotational dimension) to the joining mechanism. Instead of relying solely on the cylindrical member's radial dimension for both force and rotation control, the inclined surface adds a rotational dimension of control through its engagement with the inner edge portion, allowing the cylindrical member to remain compact.
3Strength
If the restoring force of the cylindrical member is increased to regulate relative movement, then the joined force is increased, but the cylindrical member is possibly damaged during press-fitting
Solution Approach 1:
The invention separates the joined force generation function (cylindrical member's restoring force) from the rotational regulation function (inclined surface engagement). This allows the cylindrical member to be optimized for providing adequate joined force through controlled radial expansion, while the inclined surface handles rotation control without requiring excessive restoring force that would cause press-fitting damage.
Solution Approach 2:
The invention changes the parameter of rotational control from radial dimension (cylindrical member diameter) to angular dimension (inclined surface geometry). This parameter change allows the cylindrical member's restoring force to be optimized for joined force generation at appropriate levels, without needing to be excessively high for rotation control, thereby preventing press-fitting damage.
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 design effectively regulates relative rotation and movement between members, ensuring reliable press-fitting and joint stability without being influenced by the size of the press-fitted margin, thus preventing damage and maintaining structural integrity.
Implementation Method 1
a restoring force of one of the two members that is press-fitted to a hole provided in the other member is applied to a portion where the one member and the other member abut against each other, so as to regulate relative movement of the one member to the other member, the restoring force causing the one member to attempt to return to an original shape
Data Source
AI summary
A joined body includes: a first member having a hole; and a second member that is press-fitted to the hole. The second member has a second abutment surface abutting against a first abutment surface which is an inner wall of the first member forming the hole. A groove portion is defined on one of an inner wall of the first member and an outer wall of the second member, and has a groove formed to extend in a press-fitting direction of the second member to the first member. An insertion portion is formed to protrude in a radial direction from the other of the inner wall of the first member and the outer wall of the second member, and is inserted in the groove. The groove portion has an engagement portion that is able to be engaged with an end portion of the insertion portion in the press-fitting direction.