How to judge the stability of injection molding manipulator?

Judging the stability of injection molding manipulator can start from the following aspects:

First, the mechanical structure

Rationality of structural design

Observe the overall structure of the manipulator. A stable injection manipulator usually has a solid frame structure, such as a manipulator made of high-strength aluminum alloy or steel. This material can bear large load and stress, and it is not easy to deform during long-term and frequent work. Like an industrial-grade injection molding manipulator, the wall thickness and connecting part of the manipulator are carefully designed to ensure sufficient rigidity.

Reasonable joint design is also crucial. The joint parts of multi-joint manipulator should have good sealing and accuracy. For example, the joint with high-precision harmonic reducer can not only realize accurate motion control, but also effectively prevent impurities such as dust and oil pollution from entering, thus ensuring the long-term stable operation of the joint.

Mass of moving parts

The quality of linear guide rail, slider and other moving parts in the manipulator directly affects the stability. High-quality linear guide rail has high-precision raceway, which can ensure the stability of mechanical arm in the process of linear motion. For example, some manipulators with high-precision grinding-grade linear guides can achieve micron-level accuracy, and will not get stuck or shake during frequent movements such as expansion, contraction and lifting.

For rotating parts, such as motors and rotating joints, its rotating accuracy and stability are very important. Servo motor is usually used to provide accurate rotating power. The higher the accuracy of its encoder, the more accurate the rotation control of the motor. For example, a servo motor with a high-resolution encoder (such as more than 20 bits per revolution) can accurately control the rotation angle of the manipulator and reduce the angle error, thus improving the overall stability of the manipulator.

Second, the control system

Control algorithm accuracy

Advanced control algorithm can ensure the accuracy and stability of manipulator action. For example, the injection manipulator with PID (Proportional-Integral-Differential) control algorithm can adjust the output of the motor in real time according to the deviation between the set target position and the actual position, thus achieving accurate position control. In complex trajectory control, such as grasping and placing products according to specific curves in three-dimensional space, high-precision control algorithm can ensure that the manipulator moves strictly according to the predetermined trajectory without deviation or jitter.

Some high-end manipulators will also adopt intelligent control algorithms, such as fuzzy control or neural network control. These algorithms can automatically adjust the control parameters according to the changes of working environment and tasks, and further improve the stability. For example, when encountering products with different weights, the intelligent control system can automatically adjust the grasping strength and moving speed to ensure smooth operation.

Anti-jamming ability of system

There are usually various electromagnetic interference sources in injection molding workshop, such as motor start-stop and high-frequency heating equipment of large injection molding machine. A stable manipulator control system should have good anti-interference ability. For example, anti-interference measures such as shielded wires and filters are adopted in the circuit design of the control system, which can effectively reduce the influence of external electromagnetic interference on signal transmission.

In terms of software, the system has the function of error detection and correction. When there is short-term signal interference or wrong instructions, it can be found in time and take corresponding corrective measures, such as resending correct instructions or carrying out safety braking, so as to avoid abnormal actions of the manipulator.

Third, the work performance

Repetitive positioning accuracy

Repetitive positioning accuracy is an important index to measure the stability of injection molding manipulator. It represents the accuracy of the manipulator returning to the same target position many times under the same working conditions. For example, the repetitive positioning accuracy of an excellent injection manipulator can reach within 0.1 mm. This means that every time the product is grabbed and placed, the mechanical arm can reach the predetermined position accurately, ensuring the consistency and stability of the production process.

The accuracy of repeated positioning can be evaluated through actual tests. Select several test points in the working range of the manipulator, let the manipulator move to these points repeatedly, use high-precision measuring tools (such as laser interferometer) to measure the deviation between the actual position and the set position, and count the deviation data to judge its repeated positioning accuracy.

Balance between load capacity and stability

The injection manipulator should be stable under different load conditions. When it is close to the rated load, it should work normally without obvious jitter or instability. For example, a manipulator with a rated load of 10 kg can still smoothly complete the handling task when grabbing 8-10 kg of products.

You can test by gradually increasing the load and observe the motion state of the manipulator under different loads. If the manipulator appears obvious vibration intensification, uneven movement speed or decreased positioning accuracy during the process of load increase, it shows that there may be problems in the balance between load capacity and stability.