Press Machine Controller Vibration Restart Bottom Dead Center
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Solution Overview
Problem
Conventional press machines require large and expensive servo motors to restart the slide at the bottom dead center due to static friction, increasing production costs.
Innovation Solution
A press machine controller that generates a vibration command to add dynamic friction when the slide is at the bottom dead center, allowing for restart with a small torque by adding a vibration command to the position, speed, or torque commands for the servo motor.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Force
If a large servo motor is used to restart the press machine at the bottom dead center, then the press machine can overcome static friction and restart, but the production cost increases
Solution Approach 1:
The patent applies mechanical vibration by adding a vibration command to the servo motor control during the restart phase. This vibration creates dynamic friction conditions that prevent the slide from remaining stationary at the bottom dead center, thereby reducing the torque requirement and allowing a smaller, more cost-effective servo motor to be used.
Solution Approach 2:
The patent implements periodic action through the vibration command that is added during the restart sequence. This periodic vibration is applied only during the critical restart phase from the bottom dead center position, creating temporary dynamic conditions that reduce friction without requiring continuous high torque, thus enabling the use of a smaller motor.
2Ease of operation
If the press machine is stopped at the bottom dead center for operation confirmation, then operational checking is enabled, but static friction prevents restart with a small torque
Solution Approach 1:
The patent applies preliminary action by detecting when the slide is positioned at the bottom dead center and preparing the vibration command in advance. When restart is initiated, the vibration command is immediately applied to transition from static to dynamic friction conditions, enabling restart with minimal torque after operational confirmation.
Solution Approach 2:
The patent uses mechanical vibration during the restart sequence to overcome static friction. The vibration command is added to the servo motor control, creating dynamic motion that reduces friction from static to dynamic levels, allowing restart with a small torque even after the machine has been stopped for operation confirmation.
3Force
If the reduction ratio is maximized at the bottom dead center, then torque requirement is increased, but this requires a larger servo motor size
Solution Approach 1:
The patent applies mechanical vibration during the restart phase to reduce the torque requirement. By creating dynamic friction conditions through vibration, the system can restart with minimal torque even when the reduction ratio is maximized at the bottom dead center, thereby avoiding the need for an oversized servo motor.
Solution Approach 2:
The patent changes the control parameters by adding a vibration command to the servo motor control during restart. This parameter change transforms the friction condition from static to dynamic, reducing the torque requirement and allowing the use of a smaller servo motor even when the mechanical reduction ratio is maximized.
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
Enables the press machine to restart under dynamic friction with a small torque, reducing the need for a large servo motor and lowering production costs.
Implementation Method 1
the inertial force fails to work and the static friction acts on the link mechanism, etc. Therefore, a large torque is required to restart the press machine
Data Source
AI summary
A press machine controller (10) for controlling a press machine (30) having a servo motor (41) to drive a slide (38) via a reduction mechanism (37) changed in reduction ratio in accordance with the position of the slide (38) is disclosed. The device includes a command generator (20) for generating at least one of a position command, a speed command and a torque command for the servo motor (41); a vibration command generator (13) for generating a vibration command based on a parameter preset for the press machine controller (10); a slide position detector (12) for detecting the position of the slide (38); and a vibration command adding portion (21, 22, 23) for adding the vibration command to any one of the position command, the speed command and the torque command for the servo motor (41) in the case where the slide position is in a predetermined range. The press machine, even if stopped with the slide at the bottom dead center, can be restarted with a small torque.