Machine Tool Workpiece Clamping with Friction Compensation
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Solution Overview
Problem
Existing clamping devices for machine tools face issues with operational inaccuracy due to varying frictional forces on hydraulic pistons, leading to uneven clamping of workpieces, which can deform lightweight materials like aluminum and compromise machining quality.
Innovation Solution
A device with a friction compensation assembly and lubrication system that adjusts preload forces on clamping pistons to ensure simultaneous and stable clamping of workpieces, using hydraulic and pneumatic pistons with lubrication to minimize friction and synchronize piston movements.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Force
If hydraulic pistons are used to exert large clamping forces, then the clamping force is improved, but the frictional resistance from seals causes uneven piston timing and jaw contact
Solution Approach 1:
The patent introduces a friction compensation assembly that applies a compensating force parameter to counterbalance the varying frictional resistance from seals. This ensures that despite differences in seal compression and friction between pistons, all jaws contact the workpiece simultaneously, resolving the timing precision issue while maintaining high clamping force.
2Stability of the object's composition
If high clamping forces are applied to secure lightweight materials, then the workpiece stability is improved, but the risk of workpiece deformation increases
Solution Approach 1:
The patent employs preliminary action by pre-compressing the sealing elements to a controlled degree during assembly, and by pre-adjusting the friction compensation assembly to provide balanced forcing. This preliminary preparation ensures that when clamping forces are applied, all jaws contact the workpiece simultaneously and evenly, maintaining both stability and dimensional accuracy of lightweight materials.
3Reliability
If seal compression is increased to improve sealing, then the leak prevention is improved, but the sliding resistance of pistons increases
Solution Approach 1:
The patent optimizes the seal compression parameter to achieve the minimum necessary for effective sealing while minimizing frictional resistance. The friction compensation assembly then provides a controlled additional force to balance any remaining differences in piston resistance, allowing reliable sealing without excessive sliding resistance that would cause uneven jaw contact.
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 device achieves precise and reliable clamping of workpieces without deformation, ensuring accurate and repeatable machining by compensating for frictional differences in piston operations.
Implementation Method 1
the pistons allow, thanks to the thrust exerted by a pressurized hydraulic fluid, the sliders to slide along opposite ways of their relevant directions of work
Implementation Method 2
the seals fitted on the hydraulic pistons always exert a certain resistance to the sliding of the latter and that this resistance has, not infrequently, different intensities between one piston and another
Implementation Method 3
A device with a friction compensation assembly and lubrication system that adjusts preload forces on clamping pistons to ensure simultaneous and stable clamping of workpieces, using hydraulic and pneumatic pistons with lubrication to minimize friction
Data Source
AI summary
The device (1) for clamping workpieces on machine tools comprises:a basic body (2);gripping means (7) associated with the basic body (2) and movable between a clamping configuration and a release configuration;a movement unit (8) which is associated with the basic body (2) and is adapted to move the gripping means (7) between the clamping configuration and the release configuration, comprising:a first slider (9a);a first clamping piston (11a) associated with the first slider (9a);a first release piston (12a) associated with the first slider (9a);a second slider (9b);a second clamping piston (11b) associated with the second slider (9b);a second release piston (12b) associated with the second slider (9b); anda friction compensation assembly (30, 31) associated with the clamping pistons (11a, 11b).