Metal Bushing with Elastic Inner Region for Captive Screw Fixation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing structures for build-in screws in bushings require additional processes such as screw rotation or additional parts for fixation, which complicate assembly and increase cycle time in sensor units within vehicles.
Innovation Solution
A metal bushing with an inner elastic region, typically made of plastic, is used to captively connect the screw by deforming the flexible area during injection molding, allowing for a press-in assembly without additional parts or rotation, enhancing stability and reducing assembly forces.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a screw connection is used to fix the screw in the bushing, then the screw is securely fixed, but additional parts and processes are required, increasing device complexity and assembly time
Solution Approach 1:
The invention merges the screw fixation function directly into the bushing structure by creating an integrated screw reception area with circumferential support surfaces. The screw is pressed directly into the bushing material without requiring separate retaining parts, combining the bushing and screw fixation into a single integrated component that reduces assembly complexity while maintaining secure fixation.
Solution Approach 2:
The bushing structure provides self-service fixation through its geometric design. The circumferential support surfaces and recess geometry automatically guide and secure the screw during the press-in process without requiring additional fastening operations or parts. The structure itself performs the fixation function through its shape and material properties.
2Reliability
If traditional screw fixation methods are used, then the screw is securely attached, but the assembly process requires screw rotation and additional steps, increasing assembly time and reducing productivity
Solution Approach 1:
The bushing is pre-formed with the screw reception area and circumferential support surfaces during manufacturing. This preliminary preparation eliminates the need for subsequent screw rotation or additional fixation steps during assembly. The press-in process directly achieves secure fixation without requiring preliminary threading or additional operations, significantly reducing assembly cycle time.
Solution Approach 2:
The invention extracts and eliminates unnecessary intermediate steps from the traditional screw fixation process. By removing the need for screw rotation, threading operations, and additional retaining parts, the design achieves secure screw attachment through a single press-in action, dramatically improving assembly productivity while maintaining connection stability.
3Reliability
If additional parts are used to fix the screw in the bushing, then the screw is securely retained, but the device complexity increases and assembly forces become more complex
Solution Approach 1:
The invention merges multiple functions into the single bushing component. The bushing simultaneously provides structural support, guidance, and screw fixation through its integrated recess geometry with circumferential support surfaces. This eliminates the need for separate retaining rings, clips, or other additional fixation parts, reducing component count while ensuring reliable screw retention.
4Ease of manufacture
If the screw is pressed in without deforming a flexible area, then the assembly process is simpler, but the screw and bushing are not captively connected, reducing fixation stability
Solution Approach 1:
The invention utilizes material parameter changes during the press-in process. The bushing material in the screw reception area is designed to deform elastically under pressing force, allowing the screw to be inserted, and then retains the screw through elastic recovery and friction. This parameter change enables captive connection through a simple press-in operation without requiring complex deformation mechanisms.
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 simplifies the assembly process, reduces cycle time, and improves the stability of the screw fixation within the sensor housing, enabling automated pre-assembly with low assembly forces and eliminating the need for additional parts or screw rotation.
Implementation Method 1
a elastic material at an inner region forming a flexible area in which a thread shank of the screw is pressed in by deforming the flexible area
Implementation Method 2
it is connected in the through hole of the component under elastic deformation with frictional engagement and/or with form fit
Data Source
Figure 1
Figure 2
Figure 3~4
AI summary
An improved structure of a build-in screw (20) in a bushing (30) comprises a bushing (30) made of metal and an elastic material (40) at an inner region (32) forming a flexible area (42) in which a thread shank (24) of said screw (20) is pressed in by deforming said flexible area (42), so that said screw (20) and said metal bushing (30) are captively connected.