Screw type additive manufacturing spray head

Abstract

The invention discloses a screw type additive manufacturing spray head. Particles of the conventional size can be used as a raw material, the material extrusion process is stable, the extrusion force is large, and the forming efficiency is high. The screw type additive manufacturing spray head comprises a machine barrel, a nozzle fixed to the front end of the machine barrel, a screw arranged in the machine barrel and a drive motor fixed to the rear end of the machine barrel. The tail end of the screw is arranged in a cone shape. The front end of the screw is connected with the output end of the drive motor. The part, provided with a thread, of the screw is sequentially provided with a feeding segment, a compression segment and a metering segment from the front end to the tail end according to threaded groove depths. The groove depth of the feeding segment is the maximum, and the feeding segment is arranged in an equal groove depth manner. The groove depth of the metering segment is the minimum, and the metering segment is arranged in an equal groove depth manner. The groove depth of the compression segment is gradually changed into the minimum groove depth from the maximum groove depth. A feeding opening is formed in the position, corresponding to the feeding segment of the screw, of the machine barrel. A first heating ring is arranged at the position, corresponding to the compression segment, of the machine barrel, and a second heating ring is arranged at the position, corresponding to the metering segment, of the machine barrel. The interior of the nozzle is arranged in the manner of a conical face matched with the tail end of the screw. A set of heating bars is arranged on the nozzle in an inserted manner.

Description

technical field [0001] The invention belongs to the field of additive manufacturing (3D printing) material processing, relates to fusion deposition forming technology, and specifically relates to a screw type additive manufacturing nozzle. Background technique [0002] Fused deposition modeling (FDM) is a relatively mature technology in the field of rapid prototyping. Its main working principle is: the material is heated and melted in the nozzle, and extruded from the nozzle with a certain extrusion force. The nozzle moves along the section profile of the part and the filling track, the molten material is extruded, accumulated and solidified, and the material extruded from the next layer is bonded to the previous layer, superimposed layer by layer until the part is finally formed. The screw-type additive manufacturing nozzle has attracted widespread attention due to its advantages of high extrusion force and high forming efficiency. However, the existing screw-type additive...

AI Technical Summary

Problems solved by technology

However, the existing screw-type additive manufacturing nozzles have deficiencies in the selection range of raw materials, screw size and structural design, which limit its application range to a certain extent.

[0003] There are mainly the following deficiencies in the prior art: 1. Most screw-type additive manufacturing nozzles can only use wire as raw material, which increases the production cost of raw materials and limits the selection of raw materials

The small diameter of the screw will cause the following problems: it is impossible to use larger-sized pellets smoothly, and it is prone to jamming during operation; the extrusion efficiency of restricted materials cannot be further improved

The reasons for the decline of the forming effect due to the increase of the screw diameter are: (1) The space between the screw and the barrel increases, and the material is not easy to be filled densely, resulting in uneven discharge and affecting the forming quality; (2) The increase of the screw size makes it rotate The required torque increases and the load increases, which affects the stability of the nozzle operation and affects the stability of the material extrusion process; (3) The increase in the size of the screw increases the overall size and weight of the nozzle, which affects the operation of the equipment. process stability

The diameter of the screw directly limits the depth of the screw, and the smaller diameter of the screw prevents the smooth use of granular materials as raw materials, and the diameter of the screw directly limits the discharge speed of the nozzle, making it impossible to further improve the forming efficiency of the fused deposition modeling technology

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