During the laser cladding process, the stability of the powder feeding amount is a key parameter to ensure process quality. In large parts and batch laser cladding processing, the stability of long-term uninterrupted powder feeding is often interfered with by many factors such as powder feeding air pressure, remaining powder amount, powder path wear, etc., resulting in large fluctuations in cladding accuracy and quality. Huirui independently developed a high-precision powder feeder HR-SFPFH-DT1H06 with a real-time weighing function, which can completely solve the above-mentioned cladding process stability problem. The dynamic weighing of the powder feeder can monitor the powder delivery amount in real-time, detect the powder amount in the powder barrel in real time, improve the powder delivery accuracy, and realize online visualization of powder delivery parameters.
When using the real-time weighing powder feeder, it is divided into speed mode and powder feeding rate mode, and the corresponding selection can be made in the system settings. When the powder feed rate is “ON”, the system operates to automatically calibrate the powder feed rate. In manual mode, enter the required powder feeding rate, and the system will automatically feed powder according to the set powder feeding rate during operation. At this time, the speed mode is invalid, and the system will match the corresponding speed according to the real-time powder feeding rate without manual intervention. When the powder feed rate is set to “OFF” in the system settings, the powder feed rate is invalid. In manual mode, enter the corresponding speed, and the system will carry out powder-feeding operations according to the set speed.
The closed-loop control system of the powder feeder will quickly and effectively make corresponding powder feeding speed adjustments based on the set powder feeding rate value and the collected weight change value, and achieve the set goal through constant comparison, adjustment, and correction. parameters until the powder feeding amount stabilizes within a set area and beating range.
The test data is shown in Figure 4. The closed-loop controlled powder feed amount (green curve) undergoes a short “damping” vibration and stabilizes at the powder feed rate value set by the powder feeder, and is consistent with the actual measured powder weight data.
The powder feeder sets the powder feed rate for step changes and tests the dynamic stability and accuracy of the powder feeder closed-loop control system rising or falling according to the set value. The test is shown in Figure 5. The powder feeder will make speed adjustments in time according to the set powder feeding rate to achieve a timely response to accurate powder feeding needs. You can see the decreasing curve of the weight in the barrel (pink), which also fluctuates according to the fluctuation of the powder feed rate.
Through the above tests, it can be concluded that the real-time weighing powder feeder developed by Huirui can monitor the powder feeding amount and its long-term stability in real-time. The closed-loop control function can control the powder feeding amount to reach the user setting in a short time (30s). value, achieving the effect of stable powder feeding for a long time, and the accuracy of the powder feeding amount can be controlled within 5%. It can realize real-time online visualization of powder feeding parameters and detect the remaining powder weight in the powder cylinder, which facilitates the stable monitoring of important parameters of powder feeding during long-term laser cladding operation.
