3D Printing Nozzle

Abstract

The present invention relates to the technical field of 3D printing, and discloses a 3D printing nozzle, including a nozzle body, the nozzle body including a feed section, a heating section and a spray section from top to bottom, a pipe is vertically arranged in the feed section, a support plate, a cutting mechanism and an air intake mechanism are arranged on one side of the feed section, the cutting mechanism includes a cam driven by a first motor, a first connecting rod is hinged at the center of the cam, a second connecting rod is hinged at the end of the first connecting rod away from the cam, a slider is hinged at the end of the second connecting rod, the center of the cam is horizontally connected to the side wall of the feed section through a third connecting rod, the slider slides horizontally along the third connecting rod, a fourth connecting rod is horizontally fixedly connected to the side of the slider close to the feed section, a cutter that can cut wire is fixedly connected at the end of the fourth connecting rod, the cutter includes a spike section and a push-out section that increases a gap for the cut wire, and the spike section and the push-out section are fixedly connected. The present invention reduces the heat transfer to the solid wire of the feed section, avoids the premature softening of the wire in the feed section, and realizes the smoothness of the nozzle spraying.

Description

Technical Field

[0001] The present invention relates to the technical field of 3D printing, and in particular to a 3D printing nozzle. Background Art

[0002] 3D printing is a new manufacturing method that combines technical features such as digitization, artificial intelligence, and the application of new materials. In today's 3D printing field, the types of printing technologies are diverse. According to different printing principles, they can be divided into fused deposition modeling (FDM), stereolithography (SLA), three-dimensional powder bonding (3DP), and selective laser sintering (SLS). Compared with other technologies, the operating environment of 3D printers based on FDM technology is simple and safe. No toxic gases or chemicals are produced during the printing process. They are suitable for use in homes and offices. The requirements for printing materials are relatively low. Printing materials have the advantages of low cost, high utilization rate, and quick and easy transportation. Among them, the 3D printer includes a nozzle, a wire feeding mechanism, a transmission mechanism, a servo system and a temperature control system, etc. A feeding section, a heating section and a spraying section are set in the nozzle. The spraying section is provided with a discharge port. A pair of rollers are provided on both sides of the feeding section to roll relative to each other. Now, the solid wire is generally pushed by the rollers. The wire enters the heating section, and the solid wire becomes molten. The solid wire above acts as a plunger to provide power for the advancement of the molten wire. The pressure transmitted by the solid wire squeezes the molten wire out of the discharge port of the spraying section. However, the existing nozzle has the following problems: the temperature of the melted wire in the heating section is relatively high, which will cause excessive heat to be transferred to the solid wire in the feeding section, causing the wire in the feeding section to soften prematurely and lose the power source, so that the molten wire will block the nozzle. Summary of the invention

[0003] The present invention aims to provide a 3D printing nozzle, reduce the heat transferred to the solid wire in the feeding section, avoid the wire in the feeding section from softening prematurely, and achieve smooth spraying of the nozzle.

[0004] To achieve the above-mentioned purpose, the present invention adopts the following technical scheme: a 3D printing nozzle, including a nozzle body, which includes a feeding section, a heating section and a spraying section from top to bottom, the feeding section includes two rollers for pushing the wire forward, the wire passes through the middle of the roller and extends downward, a tube is vertically arranged in the feeding section, the lower end of the tube is connected to the upper end surface of the heating section, the tube is located directly below the roller, a support plate, a cutting mechanism and an air intake mechanism are arranged on one side of the feeding section, the support plate is horizontally fixedly connected to the side wall of the feeding section, the cutting mechanism includes a cam driven by a first motor, the center of the cam is hinged with a first connecting rod, the end of the first connecting rod away from the cam is hinged with a second connecting rod, the end of the second connecting rod is hinged with a slider, the center of the cam is horizontally connected to the side wall of the feeding section through a third connecting rod, and the slider moves along The third connecting rod slides horizontally, and the side of the slider close to the feeding section is horizontally fixedly connected with the fourth connecting rod, and the end of the fourth connecting rod is fixedly connected with a cutter for cutting the wire, and the cutter includes a spike section and a push-out section for increasing the gap for the cut wire, and the spike section and the push-out section are fixedly connected; the air intake mechanism includes an expansion airbag placed on a support plate, and a cam is located above the expansion airbag. When the cam rotates, the raised part of the cam can be squeezed with the expansion airbag, and the top of the expansion airbag is connected to the bottom of the expansion airbag through a first spring, and the side of the expansion airbag away from the feeding section is horizontally fixedly connected with an air intake pipe, and a one-way air intake valve is installed on the air intake pipe, and the other side of the expansion airbag is connected to the other side of the pipe through an air outlet pipe, and a one-way air outlet valve is installed on the air outlet pipe, and the end of the air outlet pipe is in the same horizontal plane as the cutter.

[0005] The principle of this scheme is: in actual application, turn on the first motor, first pass the wire through the upper end of the feed section into the feed section, the free end of the wire extends between the two rollers, the two rollers rotate relative to each other, the rollers and the surface of the wire rub against each other, so that the rollers convey the wire into the tube. The first motor drives the cam to rotate clockwise, the first connecting rod hinged with the cam moves toward the feed section, the second connecting rod hinged with the first connecting rod pushes the slider to move along the third connecting rod toward the feed section, the fourth connecting rod fixedly connected to the side wall of the slider pushes the cutter to move toward the wire in the tube, the spiked section of the cutter cuts the wire, the slider continues to push the cutter, the push-out section of the cutter separates the two sections of wire and slowly increases the gap between them. When the raised part of the cam contacts the upper end of the inflatable airbag, the inflatable airbag is squeezed, the volume inside the inflatable airbag becomes smaller, the pressure increases, and the gas is released by opening the one-way outlet valve. The gas enters the tube from the outlet pipe. Since the cutter and the end of the outlet pipe are at the same level, the gas in the outlet pipe fills the gap between the two sections of wire, so that the two sections of wire are isolated by the gas. According to the above principle, the wire is cut by the cutter that cuts intermittently in the tube, forming multiple wire gaps. When the wire gap moves into the heating section, the wire is heated until it melts. The molten wire is pushed to the spray section under the action of the wire in the feeding section, and finally sprayed out to form a 3D printed product.

[0006] Beneficial effects:

[0007] 1. In the present invention, the solid wire in the tube is cut to form multiple sections of solid wire, and the solid wire is pushed by the push-out section of the cutter to enlarge the gap between the solid wires, and then gas is filled into the gap, so that the multiple sections of solid wire are isolated by the gas. In this way, even if the wire is heated at a high temperature in the heating section, the heat conduction rate of the gas is lower than that of the solid, which greatly reduces the waste heat of the heating section from flowing back to the solid wire in the feeding section, avoiding the situation where the feeding section softens prematurely, so that the solid wire can play the role of a plunger, ensuring the smoothness of spraying the molten wire.

[0008] 2. In the present invention, the solid wire is first cut by the sharp section of the cutter, and then the gap between the two sections of the solid wire is enlarged by the push-out section, which is convenient for filling with gas; at the same time, the push-out section serves as one of the power sources for pushing the molten wire, which increases the power for driving the movement of the molten wire and can greatly reduce the blockage of the spraying section.

[0009] Preferably, a through hole is provided on one side of the tube near the cam, and the push-out section of the cutter slides horizontally in the through hole, and the push-out section includes a conical section and a sliding section, and the conical section and the sliding section are fixedly connected. By arranging the push-out section in this way, it is convenient for the push-out section to move horizontally in the tube, and it is convenient to increase the gap between the two sections of wire.

[0010] Preferably, a horizontally arranged exhaust pipe is provided at the bottom of the tube, and the free end of the exhaust pipe extends out of the feeding section. Since the gap between the two sections of wire is filled with gas, the wire becomes molten in the heating section, and the gas is mixed in it, so that there are pores in the printed product, which affects the quality of the product. Therefore, exhaust is performed before the solid wire enters the heating section.

[0011] Preferably, the cam is fixedly connected to the first motor via the first rotating shaft, a supporting rod is vertically connected to the supporting plate, a sleeve is provided at the free end of the supporting rod, a rolling bearing is provided in the sleeve, the first rotating shaft passes through the rolling bearing and is rotatably connected to the sleeve, and the first rotating shaft and the supporting rod are perpendicular to each other. By such an arrangement, the cam can be ensured to rotate stably under the drive of the first motor.

[0012] Preferably, the heating section comprises a feed pipe, and heating blocks are respectively arranged on both sides of the feed pipe. The structure has heating blocks arranged on both sides, which can heat the solid wire evenly and quickly. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 It is a structural schematic diagram of an embodiment of a 3D printing nozzle of the present invention;

[0014] Figure 2 for Figure 1 A partial enlarged view of the middle A;

[0015] Figure 3 for Figure 1 A partial enlarged view of point B in the middle;

[0016] Figure 4 for Figure 1 Schematic diagram of the structure of the coordination among the middle cam, the first motor, the support rod and the sleeve. DETAILED DESCRIPTION

[0017] The present invention is further described in detail below through specific embodiments:

[0018] The figure marks in the drawings of the specification include: feeding section 1, heating section 2, spraying section 3, feeding pipe 4, heating block 5, roller 6, fixing plate 7, pipe 8, support plate 9, cam 10, first motor 11, first rotating shaft 12, support rod 13, sleeve 14, first connecting rod 15, second connecting rod 16, slider 17, third connecting rod 18, fourth connecting rod 19, spike section 20, push-out section 21, exhaust pipe 22, expansion airbag 23, first spring 24, air inlet pipe 25, air outlet pipe 26, one-way air inlet valve 27, one-way air outlet valve 28, air inlet section 29, air outlet section 30, third spring 31, sphere 32.

[0019] Implementation example Figure 1 , Figure 3 and Figure 4As shown: 3D printing nozzle, including nozzle body, the nozzle body includes feeding section 1, heating section 2 and spraying section 3 from top to bottom, heating section 2 includes feeding pipe 4, heating blocks 5 are respectively arranged on both sides of feeding pipe 4, heating blocks 5 include electric heating wire, resistor and power supply. Feeding section 1 includes two rollers 6 arranged opposite to each other, rollers 6 are welded to the side wall of feeding section 1 through fixing plate 7, fixing plate 7 is arranged horizontally, fixing plate 7 is rotatably connected with rollers 6, rollers 6 are key-connected with a second rotating shaft, the end of the second rotating shaft extends out of the side wall of feeding section 1 and is connected with a second motor, and the wire passes through the middle of rollers 6 and extends downward. A pipe 8 is vertically bolted in feeding section 1, the lower end of pipe 8 is bolted to the upper end face of heating section 2, pipe 8 is located directly below roller 6, and the inner diameter of pipe 8 is the same as the diameter of the wire. A support plate 9, a cutting mechanism and an air intake mechanism are arranged on the left side of the feeding section 1. The support plate 9 is horizontally welded on the left side wall of the feeding section 1. The cutting mechanism includes a cam 10 and a first motor 11. The cam 10 and the first motor 11 are keyed to each other via a first rotating shaft 12. A support rod 13 is vertically welded on the support plate 9. A sleeve 14 is arranged at the free end of the support rod 13. A rolling bearing is arranged in the sleeve 14. The first rotating shaft 12 is rotatably connected to the sleeve 14 through the rolling bearing. The first rotating shaft 12 and the support rod 13 are perpendicular to each other. The center of the cam 10 is hinged with a first connecting rod 15, the right end of the first connecting rod 15 is hinged with a second connecting rod 16, the right end of the second connecting rod 16 is hinged with a slider 17, the center of the cam 10 is horizontally connected to the side wall of the feed section 1 through a third connecting rod 18, the slider 17 slides horizontally along the third connecting rod 18, the right side of the slider 17 is horizontally welded with a fourth connecting rod 19, the end of the fourth connecting rod 19 is bolted with a cutter, the cutter includes a spike section 20 and a push-out section 21 for increasing the gap of the cut wire, the spike section 20 and the push-out section 21 are welded, a through hole is opened on the left side of the tube 8, the push-out section 21 of the cutter slides horizontally in the through hole, the push-out section 21 includes a conical section and a sliding section, the conical section and the sliding section are welded. A horizontally arranged exhaust pipe 22 is provided at the bottom of the tube 8, and the free end of the exhaust pipe 22 extends out of the feed section 1.

[0020] like Figure 1 and Figure 2As shown, the air intake mechanism includes an expansion bag 23 placed on a support plate 9, and a cam 10 is located above the expansion bag 23. When the cam 10 rotates, the raised portion of the cam 10 can be pressed against the expansion bag 23. The top of the expansion bag 23 is connected to the bottom of the expansion bag 23 through a first spring 24. The left side of the expansion bag 23 is horizontally connected with an air intake pipe 25, and a one-way air intake valve 27 is installed on the air intake pipe 25. The one-way air intake valve 27 sequentially connects an air intake section 29 and an air outlet section 30. The shape of the air intake section 29 is triangular. The end of the air intake section 29 away from the air outlet section 30 is connected to a third spring 31, and the end of the third spring 31 is connected to a sphere 32. The right side of the expansion bag 23 is connected to the other side of the pipe 8 through an air outlet pipe 26. A one-way air outlet valve 28 is installed on the air outlet pipe 26. The end of the air outlet pipe 26 is in the same horizontal plane as the cutter.

[0021] In actual application, the first motor 11 and the second motor are turned on, and the wire is first passed through the upper end of the feed section 1 into the feed section 1, and the free end of the wire is inserted between the two rollers 6. The two rollers 6 are driven by the second motor to rotate relative to each other, and the rollers 6 rub against the surface of the wire, so that the rollers 6 convey the wire into the tube 8. The first motor 11 drives the cam 10 to rotate clockwise (such as Figure 1 As shown in the figure, the first connecting rod 15 hinged with the cam 10 moves in the direction of the feed section 1, the second connecting rod 16 hinged with the first connecting rod 15 pushes the slider 17 to move along the third connecting rod 18 in the direction of the feed section 1, and the fourth connecting rod 19 fixedly connected to the side wall of the slider 17 pushes the cutter to move toward the wire in the tube 8, the spike section 20 of the cutter cuts the wire, the slider 17 continues to push the cutter, and the push-out section 21 of the cutter separates the two sections of wire and slowly increases the gap between them. When the raised part of the cam 10 abuts against the upper end of the expansion airbag 23, the expansion airbag 23 is squeezed, the volume inside the expansion airbag 23 becomes smaller, the pressure becomes larger, the gas is released by opening the one-way outlet valve 28, and the gas enters the tube 8 from the outlet pipe 26. Since the cutter and the end of the outlet pipe 26 are at the same horizontal plane, the gas in the outlet pipe 26 is filled into the gap between the two sections of wire, so that the two sections of wire are isolated by the gas. When the raised portion of the cam 10 is separated from the upper end of the expansion bag 23, the first spring 24 in the expansion bag 23 returns to its original position, the air pressure in the expansion bag 23 decreases, forming a negative pressure state, and the one-way air intake valve 27 opens, and the outside air enters the expansion bag 23. According to the above principle, the wire is cut by the cutter that cuts intermittently in the tube 8, forming a plurality of wire gaps. When the wire gap moves into the heating section 2, the wire is heated until it melts, and the molten wire is pushed to the spraying section 3 under the action of the wire in the feeding section 1, and finally sprayed out to form a 3D printed product.

[0022] The above is only an embodiment of the present invention, and the common knowledge such as the known specific technical solutions and / or characteristics in the solution is not described in detail here. It should be pointed out that for those skilled in the art, without departing from the technical solution of the present invention, several modifications and improvements can be made, which should also be regarded as the protection scope of the present invention, and these will not affect the effect of the implementation of the present invention and the practicality of the patent. The scope of protection required by this application shall be based on the content of its claims, and the specific implementation methods and other records in the specification can be used to interpret the content of the claims.

Claims

1. A 3D printing nozzle, comprising a nozzle body, wherein the nozzle body comprises a feeding section, a heating section and a spraying section in sequence from top to bottom, wherein the feeding section comprises two rollers for pushing the wire forward, wherein the wire passes through the middle of the rollers and extends downward, wherein a tube is vertically arranged in the feeding section, wherein the lower end of the tube is connected to the upper end surface of the heating section, and the tube is located directly below the roller, wherein a support plate, a cutting mechanism and an air intake mechanism are arranged on one side of the feeding section, wherein the support plate is horizontally fixedly connected to the side wall of the feeding section, wherein the cutting mechanism comprises a cam driven by a first motor, wherein a first connecting rod is hinged at the center of the cam, wherein a second connecting rod is hinged at the end of the first connecting rod away from the cam, wherein a slider is hinged at the end of the second connecting rod, wherein the center of the cam is horizontally connected to the side wall of the feeding section through a third connecting rod, and wherein the slider slides horizontally along the third connecting rod, A fourth connecting rod is horizontally fixedly connected to a side of the slider close to the feeding section, and a cutter for cutting the wire is fixedly connected to the end of the fourth connecting rod, the cutter comprises a spike section and a push-out section for increasing the gap for the cut wire, and the spike section and the push-out section are fixedly connected; the air intake mechanism comprises an expansion air bag placed on a support plate, a cam is located above the expansion air bag, and when the cam rotates, the raised portion of the cam can be squeezed against the expansion air bag, the top of the expansion air bag is connected to the bottom of the expansion air bag through a first spring, an air intake pipe is horizontally fixedly connected to a side of the expansion air bag away from the feeding section, a one-way air intake valve is installed on the air intake pipe, the other side of the expansion air bag is connected to the other side of the pipe through an air outlet pipe, a one-way air outlet valve is installed on the air outlet pipe, and the end of the air outlet pipe is in the same horizontal plane as the cutter; The heating section includes a feed pipe, and heating blocks are respectively arranged on both sides of the feed pipe, and the heating blocks include electric heating wires, resistors and power supplies; the feeding section includes two rollers arranged opposite to each other, and the rollers are welded to the side walls of the feeding section through a fixed plate, the fixed plate is arranged horizontally, and the fixed plate is rotatably connected to the rollers, and the roller keys are connected to the second rotating shaft, and the ends of the second rotating shaft extend out of the side walls of the feeding section and are connected to the second motor, and the wire passes through the middle of the rollers and extends downward; a pipe is connected to the feeding section by vertical bolts, and the lower end of the pipe is bolted to the upper end face of the heating section, and the pipe is located directly below the roller, and the inner diameter of the pipe is the same as the diameter of the wire.

2. The 3D printing nozzle according to claim 1, characterized in that: A through hole is provided on one side of the tube close to the cam, and the push-out section of the cutter slides horizontally in the through hole. The push-out section includes a conical section and a sliding section, and the conical section and the sliding section are fixedly connected.

3. The 3D printing nozzle according to claim 2, characterized in that: A horizontally arranged exhaust pipe is provided at the bottom of the tube, and a free end of the exhaust pipe extends out of the feed section.

4. The 3D printing nozzle according to claim 3, characterized in that: The cam is fixedly connected to the first motor via a first rotating shaft. A support rod is vertically connected to the support plate. A sleeve is provided at the free end of the support rod. A rolling bearing is provided in the sleeve. The first rotating shaft is rotatably connected to the sleeve through the rolling bearing. The first rotating shaft and the support rod are perpendicular to each other.

5. The 3D printing nozzle according to any one of claims 1 to 4, characterized in that: The heating section comprises a feed pipe, and heating blocks are respectively arranged on both sides of the feed pipe.

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