Rapid-forming automatic powder spreading quantity adjusting closed-loop control system and method

Abstract

The invention discloses a rapid-forming automatic powder spreading quantity adjusting closed-loop control system. The system comprises a powder spreading time detection mechanism, a powder spreading controller, a computer, a servo motor, a servo driver and a zero-point travel switch; the servo driver is connected with the output end of the powder spreading controller; the servo motor is connected with the servo driver; the zero-point travel switch is mounted on a powder spreading platform and connected with the input end of the powder spreading controller; the powder spreading time detection mechanism comprises a fixed support, an upper powder falling pipe, a lower powder falling pipe and a photoelectric sensor; a transparent pipe is connected between the upper powder falling pipe and the lower powder falling pipe; the emission end and the receiving end of the photoelectric sensor are located on the two sides of the transparent pipe, respectively; the input end of the powder spreading controller is connected with a timer; the signal output end of the photoelectric sensor is connected with the signal input end of the timer. The invention also discloses a rapid-forming automatic powder spreading quantity adjusting closed-loop control method. The rapid-forming automatic powder spreading quantity adjusting closed-loop control system is capable of realizing high-precision control of the powder spreading quantity and improving the forming precision and quality of parts.

Description

technical field [0001] The invention belongs to the technical field of rapid prototyping, and in particular relates to a closed-loop control system and method for automatic adjustment of powder spreading amount in rapid prototyping. Background technique [0002] Automatic powder-spreading high-energy beam selective melting technology is a newly developed direct 3D printing technology for metal parts. Its principle is to use a computer to layer the 3D CAD model and process the cross-section information, and then input the cross-section data into the 3D printer. The data spreads the metal powder layer by layer and uses the high-energy beam to melt the selected area of ​​the powder layer. After all the cross-sections are melted layer by layer and superimposed, the three-dimensional solid parts of the designed structural shape are obtained. The powder spreading process is a key process in the automatic powder spreading high-energy beam selective melting technology. The thickness...

AI Technical Summary

Problems solved by technology

However, since it is difficult to directly and accurately detect the amount of powder spreading powder, in the current commonly used scraper / sheet powder spreading method, the powder spreading mechanism is used to spread powder on the powder spreading platform, and the powder spreading scraper is installed in the powder spreading mechanism. Control the landing of the forming platform to control the thickness of the powder layer. There is no rapid prototyping powder amount detection device, and it is impossible to accurately detect the amount of powder in real time, and it is impossible to make real-time compensation and adjustment according to the actual powder demand, which affects the high-energy beam selective melting process. Optimization adjustment

If the amount of powder spread is too small, the powder spread in the powder spread area will be incomplete, which will cause the error of the forming size of the part. The formation is terminated due to powder, which seriously affects the stability of the high-energy beam selective melting process, and the formed parts are often defective or scrapped.

At present, the commonly used method of quantitative powder feeding is an open-loop control system. It is difficult to compensate and adjust the powder amount in real time according to the actual situation. The excessive powder amount method, the powder waste is serious, and the powder amount of the real powder layer is still uncontrollable

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