Segmented Sleeve for Extensible Driving Device Slidability
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Solution Overview
Problem
The extensible/contractible driving device experiences issues with slidability due to shape distortion of the intervening sleeve and interference among components, leading to rubbing sounds and decreased workability, particularly when using metallic cylinders.
Innovation Solution
The device incorporates a rotatable driving member, a drive force-transmitting member, and an elastic member with an intervening sleeve that includes multiple component parts with a longitudinal length, allowing relative displacement to prevent distortion and interference, thus enhancing slidability and assembly efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a sleeve is provided to cover most part of the inner surface of the external cylinder to suppress rubbing sound and smooth relative movement, then slidability is improved, but the sleeve shape becomes difficult to form by die forming and may be distorted
Solution Approach 1:
The sleeve is divided into multiple segments (first sleeve segment and second sleeve segment) that can be formed separately by die forming and then assembled together. This segmentation allows each segment to be formed without distortion while maintaining the overall function of covering the inner surface of the external cylinder.
Solution Approach 2:
The multiple sleeve segments are nested or fitted together to form the complete sleeve structure. The segments are assembled in sequence within the external cylinder, allowing the sleeve to achieve full coverage while avoiding the distortion problems of single-piece forming.
2Ease of operation
If a long-length sleeve is used to cover most part of the external cylinder, then slidability is improved, but the sleeve shape may be distorted during extrusion molding
Solution Approach 1:
The long-length sleeve is segmented into multiple shorter sections that can be formed by die forming without distortion. Each segment maintains the necessary length for smooth operation while avoiding the shape distortion that occurs with single-piece extrusion of long components.
Solution Approach 2:
The sleeve segments are pre-formed by die forming to precise dimensions before assembly. This preliminary formation ensures each segment has the correct shape and dimensions, preventing distortion during the final assembly process.
3Ease of manufacture
If a distorted sleeve is used, then manufacturing may be simpler, but contact between the sleeve and external cylinder/internal cylinder deteriorates slidability
Solution Approach 1:
By segmenting the sleeve into multiple sections formed by die forming, the invention achieves manufacturing simplicity without distortion. Each segment is formed to precise dimensions, ensuring proper contact surfaces with the external and internal cylinders while maintaining ease of assembly.
Solution Approach 2:
The sleeve segments are designed with specific local qualities - the outer surface of each segment is precision-formed to ensure proper contact with the external cylinder, while the inner surface contacts the internal cylinder. This localized precision ensures slidability without requiring the entire sleeve to be formed in one complex operation.
4Ease of manufacture
If a distorted sleeve is used, then manufacturing may be simpler, but interference among composing members deteriorates workability
Solution Approach 1:
The segmented sleeve structure allows each segment to be manufactured separately with precise dimensions, eliminating interference problems. The segments are designed to assemble in a specific sequence without interference among composing members, improving overall workability while maintaining manufacturing simplicity.
Solution Approach 2:
The sleeve segments are pre-formed with precise dimensions and features that facilitate interference-free assembly. The preliminary formation includes provision of assembly features such as fit surfaces and alignment elements that guide the assembly process and prevent interference among components.
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 effectively suppresses the problems of shape distortion and interference, reducing abnormal noise and improving the smooth operation of the extensible/contractible driving device, ensuring stable and smooth extension/contraction for opening/closing applications.
Implementation Method 1
an elastic member disposed in the periphery of the drive force-transmitting member, connected to the leading end of the internal cylinder, and configured to apply biasing force in the rotary shaft direction to the drive force-transmitting member
Implementation Method 2
an intervening member stored in an inner space between the external cylinder and the internal cylinder, disposed in the periphery of the internal cylinder, and intervening between the internal cylinder and the external cylinder
Data Source
AI summary
This extensible/contractible driving device includes a rotatable driving member configured to be rotated by drive force of a driving unit; a drive force-transmitting member connected to a leading end of the internal cylinder, configured to be driven by the rotatable driving member so as to move along a rotary shaft direction of the rotatable driving member; and an elastic member disposed in the periphery of the drive force-transmitting member, connected to the leading end of the internal cylinder, and configured to apply biasing force in the rotary shaft direction to the drive force-transmitting member. The rotatable driving member, the drive force-transmitting member, and the elastic member include an intervening member (24) stored in an inner space between external and internal cylinders, disposed in the periphery of the internal cylinder, and intervening between the internal cylinder and the external cylinder. The intervening member (24) includes a plurality of component parts (31a, 31b) having a length in a longitudinal direction of the external cylinder. One of the component parts (31a) is displaced relatively with respect to the other component part (31b) so that the intervening member (24) is opened widely outward. Accordingly, it is possible to suppress a problem of slidability caused by distortion in shape of the intervening member (24) and a problem of interference among the composing members.