Vertical Cam Barrel Tool Changer for Machine Tools
Solution Overview
Problem
Existing mechanical cam gears in tool changers for machine tools have large diameters, leading to high moments of inertia and mechanical loadings, requiring high driving powers and significant constructional space, which increases tool change cycle times and is inefficient.
Innovation Solution
A compact mechanical cam gear design with a cam barrel and Maltese wheel system, where the cam curve is on the peripheral surface, allowing a smaller diameter and reduced inertias, enabling fast tool changes with lower mechanical loadings and reduced space requirements.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If a large diameter cam barrel is used, then the mechanical loading is reduced, but the moment of inertia increases and the device occupies more space
Solution Approach 1:
The invention transitions from a conventional horizontal cam barrel arrangement to a vertical cam barrel arrangement. The cam barrel is positioned vertically with its axis oriented in the vertical direction, allowing the tool gripper to be lifted and lowered by vertical movement of the supporting column. This dimensional change enables compact horizontal space utilization while maintaining effective cam mechanism functionality for generating lifting and rotating movements.
Solution Approach 2:
The invention employs a dynamically adjustable supporting column that can vary its length during operation. The supporting column is extended or retracted based on the operational phase: extended during tool changing operations to provide sufficient travel distance for the cam mechanism, and retracted during metal cutting operations to minimize the overall device height. This dynamic adjustment allows the system to optimize space utilization while maintaining mechanical strength requirements.
2Volume of moving object
If a small diameter cam barrel is used, then the moment of inertia is reduced and the device occupies less space, but the mechanical loading increases
Solution Approach 1:
The supporting column incorporates dynamic length adjustment capability, allowing it to extend when high mechanical strength is needed (during tool changing) and retract when space minimization is prioritized (during metal cutting). This dynamic behavior enables the system to use a smaller cam barrel diameter without permanently compromising mechanical loading capacity, as the extended column position provides the necessary structural support during critical operations.
Solution Approach 2:
The supporting column is designed as a segmented or telescopic structure that can adjust its effective length. This segmentation allows the column to provide full structural support when extended for tool changing operations, enabling the use of a smaller cam barrel, while retracting to minimize device footprint during metal cutting operations when the cam mechanism is not actively loading the structure.
3Speed
If the cam barrel diameter is reduced, then the acceleration and deceleration speeds increase, but the curve steepness increases causing higher mechanical loadings
Solution Approach 1:
The dynamic length adjustment of the supporting column compensates for the increased mechanical loadings resulting from steeper cam curves. When the cam barrel operates with steeper curves (enabling faster acceleration and deceleration), the supporting column is in its extended position, providing maximum structural support and load-bearing capacity. This dynamic support allows the system to exploit the speed benefits of smaller cam barrels without suffering from excessive mechanical loadings.
4Area of stationary object
If a large constructional space is required, then the work spindle must be moved to the tool changer, increasing tool change cycle times
Solution Approach 1:
The invention repositions the tool changer in a vertical arrangement where the cam barrel axis is vertical, allowing the tool gripper to be positioned directly below the work spindle. This vertical dimensionality change enables the tool changer to occupy minimal horizontal space while maintaining direct alignment with the work spindle, eliminating the need for time-consuming horizontal movements of the work spindle or carriage units during tool changing operations.
Solution Approach 2:
The dynamically adjustable supporting column enables the tool changer to adapt its configuration for compact positioning near the work spindle. During tool changing, the column extends to provide the necessary travel distance for rapid tool exchange. During metal cutting, the column retracts to minimize the device footprint, allowing the work spindle to remain stationary and eliminating time-consuming repositioning movements.
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 compact design minimizes space and energy requirements, allowing for faster and more efficient tool changes with reduced mechanical stress on components, enabling the tool changer to operate in limited spaces and reducing tool change cycle times.
Implementation Method 1
a cam curve for the lifting movement of the tool gripper on its circumference
Implementation Method 2
the tappet engages with a Maltese wheel supported on a shaft which is parallel to the rotational axis of the tool gripper
Data Source
AI summary
A tool changer for machine tools, the tool changer having at least one rotatable tool gripper, a supporting column for the tool gripper which can be lifted and lowered and rotated about a rotational axis, a mechanical cam gear for generating the lifting and rotating movements of the tool gripper, all driven by a drive motor connected to a cam barrel and intermediate gearing. The cam barrel has a tappet for the rotational drive of the tool gripper on its upper front and a cam curve or groove on its peripheral surface for the lifting movement of the tool gripper. The tappet drives a Maltese wheel supported on a shaft parallel to the rotational axis of the tool gripper. The Maltese wheel, the cam barrel, and the supporting column of the tool gripper are successively supported in a manner parallel to the axis.