Interchangeable Collet Chuck With Uniform Internal Clamping Force
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Solution Overview
Problem
Existing collets for machine tools face limitations in providing a consistent clamping force over the entire length of the gripping part, are not suitable for complex parts that require internal gripping, and lack interchangeability and customization for various shapes and sizes.
Innovation Solution
A collet design featuring a rigid collet body with a removable clamping head, a plunger that changes diameter under the action of a sliding sleeve, and a needle extending over 80% of the axial length, allowing for adjustable locking and customizable machining of the clamping head.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If the collet body is split along the longitudinal axis to define fingers and the collet tip is split to create jaws, then the collet can be assembled with interchangeable tips, but the elasticity of the collet body and collet tip prevents optimal clamping force on the workpiece
Solution Approach 1:
The collet is divided into three main segments: a rigid collet body (fixed to the spindle), a rigid collet tip (interchangeable for different workpiece types), and a flexible bridge section connecting them. This segmentation allows the tip to be customized for different workpieces while the bridge section provides the necessary elasticity for clamping force, resolving the contradiction between interchangeability and clamping effectiveness
Solution Approach 2:
Different parts of the collet have different mechanical properties: the collet body and tip are made rigid for precision and interchangeability, while the bridge section is made flexible to provide elastic deformation and clamping force. This local differentiation of material properties allows each section to perform its specific function optimally
2Device complexity
If the thrust axis exerts axial force only on one side of the clamping tip, then the clamping mechanism is simple, but the diameter increase is not constant along the axial length, causing clamping force variation and workpiece misalignment risk
Solution Approach 1:
The solution moves from single-point axial forcing to distributed axial forcing along the entire length of the bridge section. The thrust force is applied continuously along the axial dimension rather than at a single location, ensuring uniform radial expansion and constant clamping force throughout the gripping portion, thereby eliminating misalignment risks
3Adaptability or versatility
If a large number of collets are used to handle parts of different sizes or shapes, then all part types can be machined, but the device complexity and inventory requirements increase
Solution Approach 1:
The collet body is designed as a universal component that can accommodate multiple different collet tips. By keeping the body standardized and only changing the tips for different workpiece types, the system achieves multi-functionality without requiring a complete set of different collets for each part size and shape, thereby reducing inventory complexity
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 design ensures a consistent clamping force over the entire length, allows for interchangeable clamping heads, and enables customization to accommodate different workpiece shapes and sizes, reducing the risk of misalignment during machining.
Implementation Method 1
under the action of the sliding sleeve
Data Source
Figure 1~3
Figure 4~5
Figure 6~7
AI summary
The invention relates to a collet (10) for a workpiece adapted to cooperate with a sliding sleeve of a machine tool. The collet (10) comprises a collet body (12) and a removable collet head (50) mounted on the collet body (12) and having a distal portion (52) for holding a workpiece during machining. The collet body (12) has a guide body (14) defining a longitudinal axis. A pusher (40) is mounted to slide inside the guide body (14) along the longitudinal axis in order to move from a first axial position in which the distal portion (52) of the collet head (50) defines a first outer diameter around which a workpiece can be mounted, to a second axial position under the action of the sliding sleeve and in which the distal portion (52) of the collet head (50) defines a second outer diameter larger than the first diameter in order to clamp the workpiece.The clamp body (12) has a distal portion (18) comprising a housing (28). The removable clamping head (50) has a proximal portion (62) mounted in the housing (28). The clamping forceps (10) are characterized in that the distal portion (18) of the clamp body (12) is rigid.