Electric Spindle Axial Force Control for Friction Welding
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current friction welding machines lack sensitivity and control due to excessive friction in hydraulic systems, leading to low-quality welds and slow correction speeds, as they are either too heavy or too weak, and fail to account for height changes during the welding process, resulting in dimensional inaccuracies and force variations.
Innovation Solution
An electric spindle with axial force control integrates a force sensor and electromechanical actuator, allowing real-time local adjustment of the tool height, enabling precise and quick force control and height correction within the spindle, independent of the machine's position, thus improving dynamic control and speed.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If hydraulic systems are used for position control, then force control is achieved, but sensitivity and control speed are reduced due to excessive friction
Solution Approach 1:
The patent replaces the hydraulic system with an electromechanical actuator that directly adjusts the tool height. This substitution eliminates the friction inherent in hydraulic seals and allows for faster, more sensitive force control through direct electromagnetic actuation of the spindle position.
Solution Approach 2:
The patent extracts the force sensing and control function from the overall machine system and places it directly in the electric spindle. By integrating a force sensor and electromechanical actuator within the spindle, the system achieves local, independent force control without relying on the machine's hydraulic position control system.
2Manufacturing precision
If the whole machine moves to correct position, then height correction is achieved, but correction speed is reduced due to great mass to be moved
Solution Approach 1:
The patent segments the height correction function from the overall machine positioning system. Instead of moving the entire machine to correct height, only the electric spindle (a small, lightweight component) is moved by the electromechanical actuator. This segmentation enables fast, precise local adjustment without the inertia constraints of moving the whole machine.
Solution Approach 2:
The patent implements dynamic height correction by using an electromechanical actuator that can rapidly adjust the spindle position in real-time based on force sensor feedback. This dynamic adjustment capability allows the system to respond quickly to surface irregularities without the speed limitations imposed by moving large machine masses.
3Strength
If CNC machines are used, then stiffness is high, but mass is very heavy reducing dynamics
Solution Approach 1:
The patent segments the stiff support structure (CNC machine) from the dynamic adjustment mechanism (electromechanical actuator in the spindle). The CNC machine provides the necessary stiffness and stability, while the lightweight electromechanical actuator provides fast, dynamic height correction without adding significant mass to the moving components.
4Weight of moving object
If articulated robots are used, then mass is low, but stiffness is very weak reducing control capability
Solution Approach 1:
The patent merges the advantages of both CNC machines and articulated robots by combining the stiff support structure of CNC machines with the lightweight, fast electromechanical actuation system. The electric spindle assembly provides the necessary stiffness for precision work while the electromechanical actuator keeps the moving mass low for fast dynamics.
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 enables precise and uniform welds by controlling force application directly at the tool tip, enhancing welding speed and quality, and improving economic profitability by reducing the need for external corrections and minimizing machine movement.
Implementation Method 1
a force sensor associated with the tool by means of an internal shaft that can move axially
Implementation Method 2
via an electromechanical actuator, allows the real-time local adjustment of the height of the tool
Implementation Method 3
the tool, with the necessary force on the product to be welded, has acquired the adequate speed and has heated the material due to friction
Implementation Method 4
has heated the material due to friction, the material begins to soften, acquiring a plastic state
Data Source
Figure 1
Figure 2
Figure 3~4
AI summary
Electric spindle with axial force control intended for friction welding and other uses, of the type used industrially for the automated welding of metal plates or metal elements, characterized in that it incorporates, inside the body of the electric spindle, a force sensor, associated with the tool by means of an internal shaft that can move axially and which, via an electromechanical actuator, allows the real-time local adjustment of the height of the tool above the material to be welded, such as to maintain a constant, controlled force during the welding and/or machining processes. The main advantage of the invention that is presented is that the height is corrected according to the force, automatically in the electric spindle itself, with much greater precision and speed, thereby providing more uniform welding results without irregularities.