Gripper Jaw Speed Control to Reduce Stop Impact Wear
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Solution Overview
Problem
Gripping or clamping devices with electric motors face high wear and tear due to the high number of gripping cycles required, often resulting in reduced service life and increased gripping times.
Innovation Solution
A method that involves a low start-up speed during the initial phase to detect stop positions, followed by a higher travel speed during the gripping phase, with controlled braking to reduce the impulse on stops, allowing for precise adjustment of motor currents and speeds to extend the device's service life.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the jaw is moved at high speed throughout the entire cycle, then gripping time is reduced and productivity increases, but the impulse on the stop increases causing damage and reducing service life
Solution Approach 1:
The patent applies periodic action by using different jaw speeds for different phases of the gripping cycle. During the approach phase, the jaw moves at high speed to reduce overall cycle time. When the jaw is near the stop (within a predetermined distance), the speed is reduced to a lower value to minimize impact impulse. This speed variation throughout the cycle allows both high productivity and reliable operation.
Solution Approach 2:
The patent changes the speed parameter dynamically during the gripping cycle. The control system adjusts the jaw speed based on the jaw's position relative to the stop. When the jaw is far from the stop, high speed is maintained for efficiency. When approaching the stop, speed is reduced to protect the stop from damage. This parameter change resolves the contradiction between speed and impact force.
2Reliability
If the jaw is moved at low speed throughout the entire cycle, then the impulse on the stop is reduced increasing service life, but gripping time increases and productivity decreases
Solution Approach 1:
The patent uses periodic action with two distinct speed phases: a high-speed approach phase for most of the travel distance, and a low-speed deceleration phase only when near the stop. This allows the majority of the cycle to benefit from high speed (improving productivity) while only the critical final portion uses low speed (protecting the stop).
Solution Approach 2:
The control system performs preliminary deceleration before the jaw reaches the stop. By detecting when the jaw is within a predetermined distance of the stop, the system提前 reduces speed to avoid high-impact collision. This preliminary action prevents damage while maintaining high overall cycle speed.
3Reliability
If the jaw is decelerated before striking the stop, then the impulse on the stop is reduced increasing service life, but the gripping time increases
Solution Approach 1:
The patent changes the speed parameter dynamically based on jaw position. Deceleration is applied only when the jaw is within a predetermined distance of the stop, not throughout the entire approach. This localized parameter change minimizes the time penalty while achieving the protective effect of reduced impact impulse.
Solution Approach 2:
The system performs preliminary deceleration at an optimal point before the stop, calculated based on the predetermined distance threshold. This timing allows the jaw to maintain high speed for as long as possible while still reducing speed in time to minimize impact, thus optimizing the balance between service life and gripping time.
4Productivity
If the motor is energized with high current to achieve high travel speed, then gripping cycle time is reduced, but the impulse on the stop increases causing damage
Solution Approach 1:
The patent applies periodic action to the motor current as well as speed. High current is supplied during the approach phase to achieve high speed, but current is reduced or cut off when the jaw is near the stop. This periodic current application pattern allows high productivity during most of the cycle while preventing high-impact damage during the critical final phase.
Solution Approach 2:
The patent changes the electrical parameter (motor current) in coordination with the mechanical parameter (jaw speed). When the jaw is within predetermined distance of the stop, the control system reduces or interrupts current supply, which naturally reduces speed and minimizes impact impulse. This parameter change eliminates the harmful effect while maintaining high overall productivity.
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 approach significantly increases the service life of gripping devices while maintaining high travel speeds and short gripping cycles by reducing the impulse on stops, allowing for reliable gripping and measurement of components.
Implementation Method 1
an electric motor and at least one jaw that is driven by the motor
Data Source
Figure 1~3
Figure 4~5
AI summary
The invention relates to a method for controlling a gripping or clamping device comprising an electric motor and at least one jaw driven by the motor and movable back and forth between stops, characterized in that: - in a start-up phase, the jaw (12) is moved at only a low approach speed vG, with which the jaw (12) is moved against the respective stop (16, 17, 20) without damage; - the position of the jaw (12) when the jaw (12) impacts the stop (16, 17, 20), and thus the positions of the at least one stop (16, 17, 20), are measured and recorded; and - in an operating phase following the start-up phase, the jaw (12) is initially moved over a distance xv at a travel speed vv that is greater than the approach speed vG, and the jaw (12) is then moved back and forth before impacting the stop (16, 17, 20). 17,20) by reducing the travel speed vv to a braking speed vgx, so that the jaw (12) is moved against the stop (16, 17, 20) without damage.