CN115891140A - Additive manufacturing device and additive manufacturing method for wire forming - Google Patents

Abstract

The invention provides an additive manufacturing device and an additive manufacturing method for wire forming. The additive manufacturing device includes a fuse pressing mechanism, a wire feeding mechanism, a moving mechanism and a control device. The fuse pressing mechanism has at least one fuse pressing head capable of heating and heating to realize the real-time heating and pressing function of the wire; the wire feeding mechanism is installed on the fuse pressing mechanism through a connecting piece to tilt the wire It is transported downward to the lower surface of the fuse pressing head to ensure that the wire is continuously fed into the area to be formed; the moving mechanism is used to drive the fuse pressing mechanism to move, and the forming path, the temperature of the fuse pressing head, and the feeding are completed by the control device. Synergistic control of functions such as silk. The invention carries out fusing and pressing at the same time, realizes the additive manufacturing of wire materials, has a compact structure, and is convenient to operate, and can meet the needs of additive manufacturing of large and complex shape parts under the limit condition of microgravity.

Description

Additive manufacturing device and additive manufacturing method for wire forming

technical field

The invention relates to the field of additive manufacturing, relates to a molding technology using wire as a raw material, and in particular to an additive manufacturing device and an additive manufacturing method for wire molding.

Background technique

Additive Manufacturing (AM) technology is a technology that uses CAD design path data and continuously accumulates materials layer by layer to complete the molding of three-dimensional solid objects. Compared with traditional manufacturing technology, AM technology can quickly and precisely manufacture parts with complex shapes on one piece of equipment, and has the characteristics of simple processing procedures, short processing cycle and high degree of automation. Thermoplastic materials and fiber-reinforced composite materials are widely used in the field of additive manufacturing due to their good plasticity, low requirements for molding conditions, and good performance of molded products.

The materials used in Fused Deposition Modeling (FDM) technology are mainly filaments made of thermoplastic materials and fiber-reinforced composite materials. The traditional FDM additive manufacturing technology is to heat and melt the filament inside the processing head, and then extrude and print through the nozzle. During the molding process of this printing method of FDM technology, the temperature of the molten thermoplastic material in the nozzle channel decreases, making it easy to form agglomerates at the bottom of the small nozzle and block the nozzle, resulting in a decrease in molding accuracy or even failure to shape. Patent CN113787712A discloses a split-type FDM 3D printer nozzle system, which cleans the residual material blocking the extrusion hole through the thread structure, but its structure is complicated, the production cost is high, and it is difficult to process accurately, and when the filament is a composite material or performance When the material is not uniform, it will still cause the nozzle to be blocked due to insufficient melting, resulting in unstable performance of the processed molded part. At the same time, due to the lack of a hot pressing process for materials, FDM technology still faces outstanding problems such as low interface bonding strength and high porosity of molded parts, which makes the interlayer mechanical properties of molded parts worse than those prepared by traditional processes, which will seriously limit thermoplasticity. Materials or filaments made of fiber-reinforced composites for effective application in the field of additive manufacturing.

Contents of the invention

The invention provides an additive manufacturing device and manufacturing method for wire forming, which can realize simultaneous melting and compaction of thermoplastic wire or fiber-reinforced composite wire during the additive manufacturing process, and has a compact structure and Simple, to improve the strength, surface quality, and interface bonding force of the formed thermoplastic material or fiber-reinforced composite material. The form of side-axis wire feeding is adopted, which improves the accuracy of wire feeding and simplifies the molding path when additively manufacturing complex parts.

In order to achieve the above object, the present invention adopts the following technical solutions:

The invention provides an additive manufacturing device for wire forming, the wire is a thermoplastic wire or a fiber-reinforced composite wire, which is characterized in that it includes a fuse pressing mechanism, a wire feeding mechanism, a moving mechanism and control device;

The fuse pressing mechanism is installed on the moving mechanism through a connecting piece, and the fuse pressing mechanism has at least one fuse pressing head capable of heating up;

The wire feeding mechanism is installed on the fuse pressing mechanism through a connecting piece, and is used to transport the wire obliquely downward to the bottom of the fuse pressing head;

The moving mechanism is used to drive the fuse pressing mechanism to move in the three-dimensional space, so as to realize the moving process in the space;

The control device is used to control the movement of the moving mechanism, the temperature rise of the fuse pressing head and the wire feeding of the wire feeding mechanism;

The moving mechanism is controlled by the control device to drive the fuse pressing head to move according to the set path, and the wire sent to the bottom of the fuse pressing head through the wire feeding mechanism is pressed against the surface of the template or core mold and heated and melted at the same time. When the compaction head moves to the next compaction point, the molten filament at the previous compaction point is cooled and solidified, so that additive manufacturing can be performed on the template or mandrel.

Further, the moving mechanism is a three-dimensional moving mechanism or a multi-axis mechanical arm.

Further, the fuse crimping head includes a heat-conducting metal head and a heating device for raising its temperature. The lower part of the heat-conducting metal head is a conical structure for increasing pressure, and the end of the conical structure is a smooth crimping head.

Further, the heating device is an electric heating device sleeved on the heat-conducting metal head.

Further, a guide groove for supporting and guiding the wire is provided between the wire outlet of the wire feeding mechanism and the lower end of the fuse pressing head.

Further, the wire feeding mechanism is connected with the connecting piece through a rotating pair capable of locking the angle, so that the wire feeding angle can be adjusted.

Further, the fiber-reinforced composite wire is prepared as a wire coated with polymer material.

Further, the fibers are chopped fibers or continuous fibers, one of carbon fibers, glass fibers or mixed fibers.

Further, the wire feeding mechanism includes a housing base and a pair of wire feeding rollers arranged in the housing base, the housing base is installed on the connector, and the guide groove is installed on the outlet of the housing base. Silk mouth end.

The present invention also provides an additive manufacturing method for wire forming, using the additive manufacturing device described in any one of the above, characterized in that it includes the following steps:

Step 1. Assemble the additive manufacturing device, and install the fuse pressing mechanism of the additive manufacturing device on the moving mechanism; adjust the inclination angle and wire feeding speed of the wire feeding mechanism according to the additive manufacturing object and wire material type;

Step 2. Use the control device to drive the fuse clamping head to move to the vicinity of the surface of the template or mandrel through the moving mechanism, start the wire feeding mechanism, and send the front end of the wire to the bottom of the fuse clamping head;

Step 3. Drive the fuse pressing head and the wire below it to move to the surface of the template or mandrel and press it tightly through the moving mechanism;

Step 4. Simultaneously start the heating function of the moving mechanism, the wire feeding mechanism and the fuse pressing head; the wire feeding mechanism continuously sends the wire to the bottom of the fuse pressing head; the moving mechanism drives the fuse pressing head according to the setting The fixed path continues to move and maintains the pressing force on the wire below it. The wire and the fuse pressing head are in contact with the outside to be heated and melted. At the same time, the wire is compacted during the pressing process, so that the molten layer and the already Sedimentary layers are tightly bound. When the fuse pressing head moves to the next point, the wire at the previous point is cooled and solidified to form the required workpiece material, and the wire forming additive manufacturing is completed.

The beneficial technical effects of the present invention are as follows:

1. The present invention integrates the melting and compaction process of thermoplastic wire or fiber-reinforced composite wire, which simplifies the mechanical structure. While melting the polymer material, the electrothermal processing head will also exert pressure on the wire to compress it. Solid, which improves the strength, surface quality and interface bonding force of the formed product.

2. In the traditional nozzle-extruded wire-out mode, the wire is melted inside the heating chamber, and the nozzle is easy to be blocked when the composite material is extruded, resulting in discontinuous manufacturing. In the present invention, the wire material outside the processing head is mainly heated through heat conduction, without nozzle extrusion, and no nozzle clogging, making the additive manufacturing process more continuous and reliable.

3. The invention utilizes the form of side-axis wire feeding to improve the accuracy of wire feeding, and simplifies the path when printing complex parts. It can be used with multi-axis machine tools, multi-axis robot processing equipment, etc., and has a wide range of applications. In addition, compared with other non-contact heating side-axis wire feeding equipment that uses laser as a heat source, the present invention does not require a laser, has lower cost, and has more controllable wire compaction, enabling precise manufacturing of large curvature geometric features .

4. The wire feeding mechanism and the fuse pressing mechanism of the present invention remain relatively fixed. During the wire feeding process, there is no need to separately adjust the angle and moving path of the wire feeding mechanism itself, and only need to control the moving path of the fuse pressing mechanism and the contact with the wire material The contact pressure is enough, the control is simple, and the processing quality is high. Forming mainly relies on contact pressure, rather than the gravity of the wire, so that the deposited layer has better spreadability, which can meet the needs of additive manufacturing in extreme environments such as microgravity and space.

Description of drawings

Fig. 1 is a schematic view of the use state of the additive manufacturing device for wire forming in the embodiment of the present invention.

Fig. 2 is a schematic diagram of an additive manufacturing device for wire forming in an embodiment of the present invention.

Fig. 3 is a schematic diagram of the surface structure of the workpiece prepared by the additive manufacturing method in the embodiment of the present invention.

Legend: 100-fuse clamping mechanism, 110-fuse clamping head, 111-thermal metal head, 112-electric heating device, 113-conical structure, 114-pressing head, 120-flange; 200 -Wire feeding mechanism, 210-guide groove, 300-three-dimensional moving mechanism, 301-base, 302-door frame, 303-X slide table, 304-Y slide table, 305-Z slide table, 400- Base plate, 500-connector, 501-crossbar, 502-clamp, 503-fastening bolt, 600-control device, 700-wire.

Detailed ways

Embodiments of the present invention will be further described in detail below in conjunction with the accompanying drawings and examples. The following examples are used to illustrate the present invention, but should not be used to limit the scope of the present invention.

In order to more clearly understand the above objects, features and advantages of the present invention, the present invention will be further described below in conjunction with the accompanying drawings and embodiments. It should be noted that, in the case of no conflict, the embodiments of the present application and the features in the embodiments can be combined with each other.

In the following description, numerous specific details are set forth in order to provide a thorough understanding of the invention, but the invention may also be practiced otherwise than as described herein. Accordingly, the present invention is not limited to the specific examples disclosed in the following description.

Embodiment 1, as shown in FIG. 1 , an additive manufacturing device for wire forming, the wire is a thermoplastic wire or a fiber-reinforced thermoplastic composite wire, including a fuse pressing mechanism 100, a wire feeding mechanism 200. Moving mechanism and control device

The fuse pressing mechanism 100 is installed on the moving mechanism through a connecting piece, and the fuse pressing mechanism 100 has at least one fuse pressing head 110 capable of heating up;

The wire feeding mechanism 200 is installed on the fuse pressing mechanism 100 through the connecting piece 500, and is used to transport the wire material 700 obliquely downward to the bottom of the fuse pressing head 110;

The moving mechanism is used to drive the fuse pressing mechanism 100 to move in the three-dimensional space, so as to realize the moving process in the space;

The control device is used to control the movement of the moving mechanism, the temperature rise of the fuse pressing head 110 and the wire feeding of the wire feeding mechanism 200;

The control device controls the moving mechanism to drive the fuse pressing head 110 to move according to the set path, and press the wire under the fuse pressing head 110 on the surface of the template or mandrel while heating and melting, when the fuse pressing head moves When reaching the next compaction point, the molten filament at the previous compaction point is cooled and solidified, so that additive manufacturing can be performed on the template or mandrel.

The moving mechanism is a three-dimensional moving mechanism 300 or a multi-axis robot arm, the specific form is not limited, and a six-axis robot arm.

The present invention also provides a three-dimensional moving mechanism 300, which has the ability to move in the three directions of X, Y, and Z, and specifically includes a base 301, a door frame 302 installed on the base 301, and a door frame installed on the door frame 302. The Y-direction slide table 304 between the two vertical beams and the Z-direction slide table 305 installed on the Y-direction slide table 304, the fuse pressing mechanism 100 is fixed on the Z-direction slide table 305 through a flange, in this embodiment , the template is a substrate 400, and the substrate 400 is installed on the base 301 through the X-direction slide 303, thereby forming a three-dimensional moving mechanism 300, so that the fuse pressing mechanism 100 can be arbitrarily moved within a certain range of three-dimensional space relative to the substrate 400 move.

As a preferred embodiment, the fuse crimping head 110 includes a heat-conducting metal head 111 and a heating device for raising its temperature. The lower part of the heat-conducting metal head 111 is a conical structure 113 for increasing pressure, and the end of the conical structure 113 is smooth. The compression head 114, the top of the heat-conducting metal head 111 is provided with a flange for connection.

As a preferred embodiment, the heating device is an electric heating device 112 sleeved on the heat-conducting metal head 111. Specifically, it can be a resistance wire heating sleeve sleeved on the upper end of the heat-conducting metal head 111. After heating, the heat-conducting metal head 111 The temperature of the pressing head 114 is raised by heat conduction, so as to realize the heating of the wire.

As a preferred embodiment, the fiber-reinforced composite filament is a filament prepared from a fiber-coated thermoplastic polymer material; the fiber is a chopped fiber or a continuous fiber, which is one of carbon fiber and glass fiber Or mixed fibers.

As a preferred embodiment, the temperature of the heat-conducting metal head 111 is set at 5-100°C above the melting point of the resin contained in the fiber-reinforced composite material; the contact pressure of the heat-conducting metal head 111 on the fiber-reinforced composite material is 0.5- 10MPa.

As a preferred embodiment, a force sensor may be provided between the fuse pressing head 110 and the moving mechanism, so as to control the pressure of the fuse pressing head 110 to press the wire.

It should be noted that the specific shape and structure of the wire feeding mechanism 200 are not limited, and the existing technology can be used. For example, this embodiment provides a structure. The wire feeding mechanism 200 includes a housing base 301 and a A pair of wire feeding rollers (not shown in the figure) in the seat 301, the housing base 301 is installed on the connecting piece 500, and the guide groove 210 is installed at the wire outlet end of the housing base 301.

As a preferred embodiment, a guide groove 210 for guiding the wire is provided between the wire outlet of the wire feeding mechanism 200 and the lower end of the fuse pressing head 110, so that the wire feeding mechanism 200 has enough room for adjusting the angle , and the wire 700 can smoothly reach the lower surface of the fuse holder 110 .

It can be further preferably improved, and the guide groove 210 is set as a telescopic guide groove 210 that can be stretched. After adjusting the inclination angle of the wire feeding mechanism 200 here, it can also ensure that the guide groove 210 is seamless with the lower surface of the fuse pressing head 110 butt.

As a preferred embodiment, the wire feeding mechanism 200 is connected with the connecting member 500 through a rotating pair capable of locking the angle, so that the wire feeding angle can be adjusted. Specifically, the connecting piece 500 is a cross bar 501, one section of the cross bar 501 is fixed on the upper end of the fuse clamping head 110 through a hoop 502, the other end is provided with a screw hole, and the wire feeding mechanism 200 is fastened by a bolt 503 is fixed in the screw hole.

Taking carbon fiber as an example, the additive manufacturing method based on the above-mentioned additive manufacturing device will be described, including the following steps:

Step 1: Assemble the additive manufacturing device, the fuse pressing mechanism 100 of the additive manufacturing device is installed on the moving mechanism; the fiber reinforced composite material is installed on the wire feeding mechanism 200, and the fiber reinforced composite is passed through the wire feeding mechanism 200 The front end of the material is sent to the bottom of the fuse pressing head 110; the inclination angle and wire feeding speed of the wire feeding mechanism 200 are adjusted according to the additive manufacturing object and the type of fiber reinforced composite material; the wire 700 used is continuous fiber reinforcement of ABS coated carbon fiber Composite material, the diameter of the wire 700 is 1.75mm, and the additive speed is 10mm/s.

Step 2: Drive the fiber-reinforced composite material under the fuse pressing head 110 to move to the surface of the template or mandrel through the moving mechanism and press it;

Step 3: Simultaneously start the heating function of the moving mechanism, the wire feeding mechanism 200 and the fuse pressing head 110; the wire feeding mechanism 200 continuously sends the fiber reinforced composite material under the fuse pressing head 110; the moving mechanism drives the fuse The wire pressing head 110 continues to move according to the set path and maintains the pressing force on the fiber-reinforced composite material below it. The fuse wire pressing head 110 heats up during the pressing process to melt and compact the fiber-reinforced composite material. When the fuse pressing head 110 moves to the next point, the fiber reinforced composite material at the previous point is cooled and solidified to form the required workpiece material, and the additive manufacturing of the fiber reinforced composite material is completed. In this embodiment, the temperature is controlled at 400° C., and multiple layers of additive deposition are performed to obtain a plate-shaped workpiece.

As a preferred embodiment, the control device is an industrial computer or a PLC controller, which is used for coordinated control of the movement of the moving mechanism, the heating of the electric heating device 112 and the wire feeding of the wire feeding mechanism 200 .

Its overall working principle is that in the process of using continuous fiber reinforced composite materials for additive manufacturing, it is first necessary to connect the fuse pressing mechanism 100 and the wire feeding mechanism 200, and fix them on the machine tool with bolts through flanges. The wire material 700 is pressed against the compression head 114 of the fuse compression mechanism 100 by the head end of the wire feeding mechanism 200, and after the carbon fiber filament is compressed, the fuse compression mechanism 100 is energized through the control device, and the fuse compression mechanism 100 is preheated for a certain period of time. After the temperature is stable, the switch of the drive motor of the wire feeding mechanism 200 is turned on, and the processing path, processing temperature, wire feeding and other functions are completed under the action of the control device. Carbon fiber-reinforced composite materials undergo processes such as melting, compaction, and movement to realize product molding. In this example, the filament 700 used is a continuous fiber-reinforced composite material of ABS coated carbon fiber, the diameter of the filament 700 is 1.75mm, and the additive speed is 10mm/s. As shown in Fig. 3, when the temperature is controlled at 400°C, this method is applied, and the additive deposition results of more than 700 layers of this silk material are obtained.

The above is only a preferred embodiment of the present invention, and is not intended to limit the present invention to other forms. Any skilled person who is familiar with this field may use the technical content disclosed above to change or remodel it into an equivalent implementation of the equivalent change. Examples are applied to other fields, but any simple modifications, equivalent changes and modifications made to the above embodiments according to the technical essence of the present invention still belong to the scope of protection of the technical solutions of the present invention, as long as they do not depart from the content of the solutions of the present invention.

Claims (10)

1. An additive manufacturing device for wire forming, the wire is a thermoplastic wire or a fiber-reinforced composite wire, characterized in that it includes a fuse pressing mechanism, a wire feeding mechanism, a moving mechanism and a control device ; The fuse pressing mechanism is installed on the moving mechanism through a connecting piece, and the fuse pressing mechanism has at least one fuse pressing head capable of heating up; The wire feeding mechanism is installed on the fuse pressing mechanism through a connecting piece, and is used to transport the wire obliquely downward to the bottom of the fuse pressing head; The moving mechanism is used to drive the fuse pressing mechanism to move in the three-dimensional space, so as to realize the moving process in the space; The control device is used to control the movement of the moving mechanism, the temperature rise of the fuse pressing head and the wire feeding of the wire feeding mechanism; The moving mechanism is controlled by the control device to drive the fuse pressing head to move according to the set path, and the wire sent to the bottom of the fuse pressing head through the wire feeding mechanism is pressed against the surface of the template or core mold and heated and melted at the same time. When the compaction head moves to the next compaction point, the molten filament at the previous compaction point is cooled and solidified, so that additive manufacturing can be performed on the template or mandrel. 2. The additive manufacturing device according to claim 1, wherein the moving mechanism is a three-dimensional moving mechanism or a multi-axis robotic arm. 3 . The additive manufacturing device according to claim 1 , wherein the fuse clamping head comprises a heat-conducting metal head and a heating device for raising its temperature. 4 . 4. The additive manufacturing device according to claim 3, wherein the heating device is an electric heating device sleeved on a heat-conducting metal head. 5 . The additive manufacturing device according to claim 1 , wherein a guide groove for supporting and guiding the wire is provided between the wire outlet of the wire feeding mechanism and the lower end of the fuse pressing head. 6 . The additive manufacturing device according to claim 1 , wherein the wire feeding mechanism is connected to the connecting member through a rotating pair capable of locking the angle, so that the wire feeding angle can be adjusted. 7 . 7. The additive manufacturing device according to claim 1, characterized in that: the fiber-reinforced composite wire is a wire prepared by coating fibers with polymer materials. 8. The additive manufacturing device according to claim 7, wherein the fibers are chopped fibers or continuous fibers, one of carbon fibers, glass fibers or mixed fibers. 9. The additive manufacturing device according to claim 5, characterized in that: the wire feeding mechanism comprises a housing base and a pair of wire feeding rollers arranged in the housing base, the housing base is installed on the connection On the piece, the guide groove is installed on the wire outlet end of the housing base. 10. An additive manufacturing method for wire forming, using the additive manufacturing device according to any one of claims 1-8, characterized in that it comprises the following steps: Step 1. Assemble the additive manufacturing device, and install the fuse clamping mechanism of the additive manufacturing device on the moving mechanism; adjust the inclination angle and wire feeding speed of the wire feeding mechanism according to the additive manufacturing object and wire material type; Step 2. Use the control device to drive the fuse clamping head to move to the vicinity of the surface of the template or mandrel through the moving mechanism, and start the wire feeding mechanism to send the front end of the wire to the bottom of the fuse clamping head; Step 3. Drive the fuse pressing head and the wire below it to move to the surface of the template or mandrel and press it tightly through the moving mechanism; Step 4. Simultaneously start the heating function of the moving mechanism, the wire feeding mechanism and the fuse pressing head; the wire feeding mechanism continuously sends the wire to the bottom of the fuse pressing head; the moving mechanism drives the fuse pressing head according to the setting The fixed path continues to move and maintains the pressing force on the wire below it. The wire and the fuse pressing head are in contact with the outside to be heated and melted. At the same time, the wire is compacted during the pressing process, so that the molten layer and the already Sedimentary layers are tightly bound. When the fuse pressing head moves to the next point, the wire at the previous point is cooled and solidified to form the required workpiece material, and the wire forming additive manufacturing is completed.

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