RU193256U1 - DEVICE FOR LOCAL THERMAL STABILIZATION OF PRODUCTS FROM COMPOSITE MATERIALS IN ADDITIVE PRODUCTION - Google Patents

Abstract

A useful model of the device for local thermal stabilization of products from composite materials in additive manufacturing relates to the field of additive technologies and can be used for thermal stabilization in the manufacture of parts and structures from composite materials reinforced with continuous fibers, such as brackets, fittings, housing elements, wearable products, mesh and honeycomb structures, various accessories for use in aviation, rocket and space technology, medicine, automotive and other industries The device consists of a print head for additive production and a vortex tube mounted on a holding bracket, with the end of the vortex tube designed to discharge the hot fraction located in the immediate vicinity of the working area of the extruder nozzles. In this case, thermal stabilization is carried out in the following way: the previous laid out layer is heated and at the same time the current, newly laid out layer is cooled to a temperature in the range limited by the temperature of the working fluid of the tube and a temperature exceeding the working fluid temperature by 110 ° С.

Description

The technical field to which the utility model relates.

The utility model relates to the field of additive technologies and can be used for temperature preparation of the product working area in the manufacture of parts and structures made of composite materials reinforced with continuous fibers, such as brackets, fittings, housing elements, wearable products, mesh and honeycomb structures, various accessories for Applications in aviation, rocket and space technology, medicine, automotive and other industries. More specifically, the present utility model relates to a device for providing the necessary temperature conditions for the manufacture of articles of composite materials using compressed air.

State of the art

A printhead for additive manufacturing of products is known from the prior art, consisting of a plastic filament feeder, a reinforcing fiber feed mechanism, a reinforcing fiber trimmer, feed tubes, and a heating unit. RU 2662015 C1 publ.: 07.23.2018 Bull. No. 21.

Also known from the prior art is a printhead for a 3D printer, comprising a movable platform made in a single housing with: a stepper motor; toothed pulley; base; flange guide plate; radiator; extruder assembly; filament channels; belt drive pulley; a fan; a spring pressing the driven gear pulley to the lead; a guide axle mounted between two supports; belt and supports. RU 174069 U1 publ.: 09/28/2017 Bull. No. 28.

Also known from the prior art is a combined system for heating and cooling — a vortex tube. In a tube containing a swirl and diffuser connected by a vortex tube, and cold and hot flow nozzles, holes and central bodies of the swirl and diffuser are placed along the axis of the vortex tube, and the swirl is connected to the central body by radial blades having a minimum twist angle near the central body and the maximum near the swirl, and the hole of the cold flow is made circular and placed between the swirl and the vortex tube. RU 2671555 C2, publ.: 11/01/2018 Bull. No. 31.

In the technical solutions described above, to improve the quality of the product and print speed, cooling fans of the printed part are used, which are directed directly under the nozzles of the print heads. Such cooling allows you to quickly reduce the temperature of the laid layer of the molten polymer (including reinforced with continuous fibers) and thereby prevents a significant change in the hermetic parameters of the part caused by creep of the heated material. There is no heating of the part in the described solutions.

Utility Model Disclosure

The task to which the claimed utility model is directed is to increase the mechanical properties, ensure the quality of the manufactured part, and also increase the speed of its manufacture.

The technical result of the claimed utility model is: increasing the laying speed of the next layer of molten thermoplastic polymer reinforced or unreinforced with continuous fibers; increased interlayer adhesion; providing the given geometry of the manufactured parts; preventing the reinforcing fiber from slipping, which reduces the strength of manufactured products; reduction of residual stresses arising due to uneven cooling of the layers of the product material.

The technical result is achieved due to the fact that a vortex tube is fixed near the print head on an arm located on a movable unit of the installation for additive production, the operation of which is based on the effect of dividing the working fluid (gas or liquid) into two fractions when it is twisted in a cylindrical or conical chamber .

Also, the technical result is achieved by local heating of the previous layer in the area of operation of the extruder nozzle to increase interlayer adhesion, increase the laying speed of the next layer of material (in the case of laying reinforced thermoplastic polymer) and reduce internal residual stresses, which in turn leads to an increase in product strength. In this case, the current layer can be heated to a temperature that is in the range limited by the temperature of the working fluid of the tube and a temperature exceeding the temperature of the working fluid by 110 ° C.

Also, the technical result is achieved by local cooling of the current layer in the area of operation of the extruder nozzle to ensure the desired geometric shape of the manufactured part and to prevent the reinforcing fiber from sliding off the specified reinforcement path (in the case of laying the reinforced thermoplastic polymer). In this case, the current layer can be cooled to a temperature that is in the range limited by the temperature of the working fluid of the tube and a temperature exceeding the temperature of the working fluid by 110 ° C.

Brief Description of the Drawings

In FIG. 1 - Device for local thermal stabilization of products from composite materials in additive manufacturing.

In the figure, the numbers indicate the following positions:

1 - tube for supplying a working fluid of a vortex tube; 2 - bracket; 3 - printhead for additive production; 4 - nozzles of the extruder of the print head; 5 - vortex tube; 6 - end of the vortex tube to exit the hot fraction of the working fluid.

Utility Model Implementation

The device for local thermal stabilization of products from composite materials in additive manufacturing is a combination of a print head fixed to a holding bracket (2) for additive manufacturing (3) of products and a vortex tube (5). The print head is capable of spreading reinforced or unreinforced thermoplastic polymer. The vortex tube is installed in such a way that the end of the tube from which the heated air (6) exits is located above the working area of the extruder nozzle (4), which provides local heating of the previous layer and simultaneous cooling of the current layer to a temperature in the range limited by the temperature of the working the body of the tube and a temperature exceeding the temperature of the working fluid by 110 ° C.

The device temperature preparation of products from composite materials in additive manufacturing works as follows:

- a print head for additive manufacturing of products mounted on a moving mechanism, in accordance with the control program and the reinforcement scheme, performs the laying out of a thermoplastic polymer reinforced or unreinforced with fiber;

- the working fluid is fed into the vortex tube under excess pressure, where, due to the Rank-Hills effect, it is divided into two fractions - hot and cold. The hot fraction is fed into the working area of the extruder nozzles, where the process of local heating of the previous layer and, simultaneously, local cooling of the current layer takes place.

The printhead for additive manufacturing can be represented by the printheads described in patents RU 2662015 C1 or RU 174069 U1.

The moving mechanism can be represented by a multi-axis industrial robot, for example, KUKA KR3 R540.

The control program can be represented by a set of commands executed in the programming language of devices with numerical program control - G-code according to GOST 20999-83.

Thermoplastic thread can be represented by serial plastics: PLA, ABS, PA (nylon), PET-G, PC, PEI, etc.

Reinforcing fiber can be represented by composite carbon fiber CCF-1.5, manufactured by Anisoprint LLC.

A vortex tube may be represented by a vortex tube described in RU 2671555 C2.

The working fluid of the vortex tube can be represented by compressed air with a pressure of 6.5 kPa. This pressure gives stable characteristics of the fractions of the working fluid. At the same time, the cold fraction from the vortex tube can be used to cool the working space of an industrial robot, the temperature of which should not exceed 55 ° C.

Claims (3)

1. The device for local thermal stabilization of products from composite materials in additive manufacturing, characterized in that the device consists of a print head for additive production and a vortex tube mounted on a holding bracket, and the end of the vortex tube, designed to drain the hot fraction, is located in close proximity to extruder nozzles the laid-out layer by blowing with an air stream leaving the end of the vortex tube intended for removal of the hot fraction, and the temperature of the air stream leaving the vortex tube can be changed in the range limited by the temperature of the working fluid of the tube and the temperature of the air flow entering the vortex tube by no more than 110 ° C. 2. The device for temperature preparation of products from composite materials in additive manufacturing according to claim 1, characterized in that a vortex tube is used as a part cooling device. 3. The device for the temperature preparation of products from composite materials during additive manufacturing according to claim 1, characterized in that a vortex tube is used as a device for heating the part.

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