阅读说明：本技术 行星齿轮切换的双色三维打印机推料装置 (Double-color three-dimensional printer material pushing device switched by planetary gears ) 是由 罗天珍 吴小平 吴丹丽 于 2020-02-24 设计创作，主要内容包括：行星齿轮切换的双色三维打印机推料装置；属于机械构造领域；本发明主体结构包括：固定在结构板的供料电机、推料齿轮、承载推料齿轮的摆臂、进料孔或过料孔；基本安装关系：供料电机驱动摆臂上的推料齿轮与固定推料齿轮齿合后夹紧而推动料丝；至少1个推料齿轮使用的是行星推料齿轮；摆臂使用的是行星支架,行星推料齿轮被安装在行星支架上的行星轴上；从轴向看去,行星推料齿轮与固定推料齿轮的较小直径的齿部之间的无料丝下的自然空隙使得在2个齿轮轴线所确定的平面的截面齿部区域的内切圆的直径小于料丝的直径可以被广泛用于FDM-3D打印机中。(A pushing device of a double-color three-dimensional printer switched by a planetary gear; belonging to the field of mechanical construction; the main structure of the invention comprises: a feeding motor, a pushing gear, a swing arm for bearing the pushing gear, and a feeding hole or a material passing hole which are fixed on the structural plate; basic installation relation: the feeding motor drives the pushing gear on the swing arm to be meshed with the fixed pushing gear and then clamped tightly to push the material wires; at least 1 pushing gear uses a planetary pushing gear; the swing arm uses a planet support, and a planet pushing gear is arranged on a planet shaft on the planet support; the natural gap without the material wire between the teeth parts with the smaller diameters of the planetary pushing gear and the fixed pushing gear when viewed from the axial direction enables the diameter of an inscribed circle of a section tooth area of a plane determined by 2 gear axes to be smaller than the diameter of the material wire, so that the natural gap can be widely used in FDM-3D printers.)

1. A pushing device of a double-color three-dimensional printer switched by a planetary gear; the main structure body comprises: a feeding motor, a pushing gear, a swing arm for bearing the pushing gear, and a feeding hole or a material passing hole which are fixed on the structural plate; basic installation relation: the feeding motor drives the pushing gear on the swing arm to be meshed with the fixed pushing gear and then clamped tightly to push the material wires; the method is characterized in that: at least 1 pushing gear uses a planetary pushing gear; the swing arm uses a planet support, and a planet pushing gear is arranged on a planet shaft on the planet support; in detail: this blevile of push still includes: the friction plate is arranged between the end part of the sun gear or the planet pushing gear and the planet support; the basic working principle is as follows: when the motor shaft and the sun shaft rotate clockwise, the planetary support is driven to rotate clockwise under the action of friction force of the friction plate caused by axial pressure of the spring 1, so that the planetary pushing gear is disengaged with the fixed pushing gear 2 to push the material wires) to move upwards to finish feeding; the driving of the material wire is realized by the meshing of the unique structures of the planetary pushing gear and the fixed pushing gear; the main body structure of the planetary pushing gear is the same as that of the fixed pushing gear: there are larger diameter gear portions and smaller diameter gear portions arranged along the axial direction; the tooth parts with larger diameters are used for mutual meshing transmission, the tooth parts with smaller diameters are used for clamping and driving the material wires, and when viewed from the axial direction, natural gaps without the material wires between the tooth parts with smaller diameters of the planetary material pushing gear and the fixed material pushing gear enable the diameter of an inscribed circle of a section tooth part area of a plane determined by the axes of the 2 gears to be smaller than the diameter of the material wires.

2. The planet carrier of the pushing device of the double-color three-dimensional printer with the planet gear switching function according to claim 1, characterized in that: the planet support keeps a free and unconstrained state or is additionally provided with a spring fixed between the structure plates to play a bistable function, one end of the spring is a fixed fulcrum fixed on the structure plates, and the other end of the spring is fixed on a motion fulcrum of the planet pushing gear, so that the planet support can obtain a deviation torque in a position state deviating from the center no matter whether the spring is pulling force or pushing force.

3. The combination of the friction plate and the sun gear or the planet pushing gear of the pushing device of the double-color three-dimensional printer switched by the planet gear according to claim 1 is characterized in that: the friction plate is directly contacted with the sun gear or the planet pushing gear or a gasket is additionally arranged between the friction plate and the sun gear or the planet pushing gear, and the gasket is in a connection relation with no slip or limited slip; under the condition of limited slip, a relative rotation limiting structure is additionally arranged between the sun gear or the planet pushing gear and the gasket, so that the relative slip angle is within +/-360 degrees.

4. The feeding hole or the material passing hole of the pushing device of the double-color three-dimensional printer switched by the planet gear as claimed in claim 1, wherein the feeding hole or the material guiding hole is a non-resistance through hole or a material wire resistance structure is placed in the feeding hole or the material guiding hole, and the structure is as follows: clamping spring, small hole or open elastic material with diameter smaller than the material moment.

[ technical field ]

The invention belongs to the field of mechanical manufacturing, and particularly relates to a single-motor-driven dual-channel FDM-3D printer extrusion device.

[ background art ]

The extruder structure of the current FDM-3D printer:

in the FDM-3D printer, an extruding device is one of the most key components of the whole printer, the extruding device determines the printing effect and efficiency, and the extruding device comprises a feeding component and an extruding component:

the feeding component is divided into long-distance feeding and short-distance feeding; the remote feeding is that the gear of the feeding motor drives the material wire to enter the Teflon hose, the Teflon hose leads to the melting cavity part through the throat, and the 2 ends of the Teflon hose are respectively and rigidly locked with the throat and the bracket of the feeding motor. The short-range feeding and the long-range feeding have no essential difference, and the difference is that a feeding motor is directly and rigidly connected with a throat pipe, so that a Teflon material guide pipe with the transmission function is omitted.

The throat pipe in the extrusion assembly is made of stainless steel, so that the heat conducting performance of the throat pipe is reduced, the stainless steel throat pipe is internally lined with Teflon for a certain time, the temperature inside the throat pipe is increased due to long-term heating and printing of the extruder assembly, so that materials in the throat pipe are in a molten state, the materials are adhered in the throat pipe after printing and cooling are stopped, the adhesion materials in the throat pipe cannot be melted immediately when the extruder assembly is restarted for printing next time, the throat pipe is blocked, and the Teflon is lined in the throat pipe, so that the materials in the throat pipe cannot be melted and adhered, and the problem of the plug can be greatly solved. Meanwhile, the author adds a radiating fin and a fan on the extruder assembly, mainly aims to reduce the temperature of the upper part of the throat pipe and prevent the problem of a choke plug, and also can radiate the extruder assembly.

The feeding of the material wires is similar to that of a piston, and the plastic wires serve as the piston to generate pressure on a melting cavity before melting and are extruded out through a nozzle; in detail: the plastic wire is pushed into the throat pipe from the inlet end of the extruder assembly, guided by the throat pipe and sent into the melting cavity of the heating aluminum block, most of the plastic wire is subjected to indirect heating on the aluminum block by a heating rod, and the plastic wire is extruded from a nozzle under the action of the pressure of a subsequent wire feeding (piston) after being fully melted.

The action point of the gear is on one side of the material wire and is pressed by the pressing wheel, so that the balance is poor, the pressure is limited, the pressure is small, the discharging is slow, and the like.

Background art for FDM-3D printer:

FDM: the Fused Deposition Modeling technique is Fused Deposition Modeling (FDM).

Before printing, built-in software of the FDM-3D printer automatically reads 3D model data and layers the data, after layering, liquid molten at high temperature is extruded out through a nozzle of an extruder, after extrusion, the liquid is rapidly condensed and solidified when being cooled, and then a three-dimensional object is formed by swinging the extruder on a plane and downward displacement of a printing plate. 3D printing needs to be completed through processes of 3D scanning and 3D modeling, and finally, a 3D printing finished product is completed. Of course, 3D printers based on FDM molding technology are no exception. In addition to the 3D scanning and 3D modeling processes, the FDM forming technique generally goes through the following links as far as 3D printing itself is concerned. Firstly, the FDM software analyzes and stratifies the 3D model data to generate a printing path and a supporting path. Second, the extruder and printed article carrying table will rise to the temperature set by the 3D model. And finally, in the printing process, a three-dimensional space is formed by the displacement of the extruder on the plane and the vertical displacement of the printing object bearing table, and the extruder and the printing object bearing table print according to the generated path. In the printing process, after the extruder finishes a printing task on one plane, the bearing table for the printed object automatically descends by one layer, and the extruder continues printing. And circulating to and fro until the finished product is finished. During the printing process, the wire inserted into the extruder is rapidly melted and extruded by the extruder to be instantly coagulated. The temperature of the extruder is relatively high, and the temperature of the extruder is relatively different according to different materials and different model design temperatures. In order to prevent the occurrence of the problems of edge warping and the like of a printed object, the printed object bearing table is generally heated, and the printed object bearing table is generally covered with adhesive paper so as to facilitate the peeling of a printed finished product. The principle of fused deposition modeling is as follows: firstly, inputting a slice file (section contour information) into a computer, wherein the thickness of a slice is generally selected to be 0.1-0.6 mm; the heating nozzle is controlled by a computer to do X-Y plane motion according to the (slice) section profile information of a product part, the thermoplastic filamentous material is sent to the hot melting nozzle by a wire supply mechanism, is heated and melted into semi-liquid state in the nozzle, is extruded out, is selectively coated on a working table, and forms a layer of sheet profile with the thickness of about 0.127mm after being rapidly cooled. And after the section of one layer is formed, the workbench descends by a certain height, then cladding of the next layer is carried out, the section outline is like to be 'drawn' layer by layer, and the steps are repeated, so that the three-dimensional product part is finally formed. The combination of the FDM-3D technology and the engraving and milling technology (CNC) at present does not have a scheme which is cost-effective and has the best effect.

The following description of the slicing procedure is given by taking the version of the open source software as an example:

the three-dimensional model file is generated into a file exported into an STL format, and then the STL format file is generated into a file in a Gcode format to be printed, so that the three-dimensional model file can be manufactured in 3ds max and other three-dimensional model manufacturing software such as Solid Works, Chinese-stroke UG, Chinese-stroke MAYA and the like. Next, a model of this block needs to be derived at 3ds max, a file in STL format is derived, and named as the appropriate file name, and it should be noted that the naming operation is performed using english or pinyin, or a combination of both alphabetic and numeric characters.

And opening the Cura software, and opening the derived STL format three-dimensional model file in the Cura software. The support is divided into two types, wherein the first item is an external support, namely a support structure which can be in contact with a printer platform, and the second item Everywhere means that all places with suspended structures are provided with support assistance; the first item is that a circle of base is added on the periphery of the model to help the model to be more firmly adhered to the platform, and the second item is that a base is added on the whole bottom of the model to help the model to be adhered to the platform, wherein the first item is generally recommended to be used; the diameter of the wire is the diameter of a consumable used by the 3D printer, and the input 2.95 is the flow value of 100% because the wire is a consumable of 3 MM; two other important parameters also need to be set: "machine settings" and "advanced settings". The setting options of the machine setting needing attention are the setting of the platform size and the extrusion amount; advanced arrangements typically require only modification of the packing density of the support therein.

The current situation and defects of the existing double-channel extruder are as follows:

the existing double-channel extruder drives independent material wires by using independent motors, and the material wires enter a material melting cavity to be mixed and extruded. For the case of non-hybrid switched use, the 2-way motors work in turn, in terms of the operating efficiency of the device: the efficiency of the drive motor is not fully exploited.

[ summary of the invention ]

The purpose of the invention is as follows:

the invention aims to overcome the defect that double paths in the prior art need independent driving motors, and 2 independent motors are replaced by a single motor.

The invention is characterized in that:

the structure is simple and mature, and the operation is reliable.

The technical scheme of the invention is as follows:

this blevile of push includes: a feeding motor fixed on the structural plate, a sun shaft, a sun gear, a planet support, a planet pushing gear, a fixed pushing gear, a planet shaft and a friction plate.

Basic installation relation: a feeding motor arranged on the structural plate drives a sun shaft to drive a sun gear, a planet support is positioned on the same rotation center as the sun shaft, and a planet pushing gear is wound on a planet shaft fixed on the planet support; friction plates are arranged between the ends of at least 1 gear of the sun gear and the planet pushing gear and the planet support; the number of the fixed pushing gears is 2, and the number of the feeding holes and the number of the material guide holes are also 2 respectively and are respectively arranged on 2 sides of the solar shaft; .

The basic working principle is as follows: when the motor shaft and the sun shaft rotate clockwise, the planetary support is driven to rotate clockwise under the action of friction force of the friction plate caused by axial pressure of the spring 1, so that the planetary pushing gear is disengaged with the fixed pushing gear 2 to push the material wires) to move upwards to finish feeding; the driving of the material wire is realized by the meshing of the unique structures of the planetary pushing gear and the fixed pushing gear, and the unique structure is as follows: the planetary pushing gear and the fixed pushing gear have the same structure: there are larger diameter gear portions and smaller diameter gear portions arranged along the axial direction; the tooth parts with larger diameters are meshed with each other and used for transmitting power mutually, the tooth parts with smaller diameters are used for clamping and driving the material wires, when the motor shaft and the sun shaft rotate anticlockwise, the condition is the same as that of the motor shaft and the sun shaft, and the planetary material pushing gear is meshed with the fixed material pushing gear on the other side. In summary; the pushing gear comprises a planetary pushing gear and a fixed pushing gear which are respectively combined with a planetary shaft and a fixed shaft, tooth structures with large diameter and small diameter are arranged along the axial direction, and a tooth structure for driving (moving) materials (wires) and a tooth structure for driving (moving) the materials (wires) are respectively processed, the structure for driving (moving) the materials (wires) is a crescent-shaped material driving tooth, the protruding height of the tooth is relatively shallow, and the contact area of the tooth and the wires can be increased; viewed from the axial direction: when the tooth parts (the maximum diameter and the most protruded part) are mutually driven to be tightly meshed, the gaps between the small-diameter tooth parts of the planetary pushing gear and the fixed pushing gear cannot allow the material filaments to smoothly pass through (the section between the minimum gaps (a plane determined by the axis of the gear 2) and the diameter of the inscribed circle of the tooth parts is smaller than that of the material filaments), so that the material filaments can be clamped.

Further: the planet support keeps a free and unconstrained state or is additionally provided with a spring fixed between the structure plates to play a bistable function, one end of the spring is a fixed fulcrum fixed on the structure plates, and the other end of the spring is fixed on a motion fulcrum of the planet pushing gear, so that the planet support can obtain a deviation torque in a position state deviating from the center no matter whether the spring is pulling force or pushing force.

Further: the sun gear or the planet pushing gear is in driving connection without slip or in connection with a gasket with slip (angle), and a relative rotation limiting structure is additionally arranged between the sun gear or the planet pushing gear and the gasket, so that the relative slip angle is within +/-360 degrees; specifically, a gasket is additionally arranged between the friction plate and the sun gear or the planet pushing gear; one side of the gasket is in contact with the friction plate. The other surface of the friction plate is contacted with the contact protrusion on the end surface of the sun gear or the planet pushing gear through the contact protrusion on the end surface of the gasket, and the contact protrusion is far smaller than the dimension of the sun gear or the planet pushing gear, so that the contact protrusions can be contacted again only when the direction is changed by idling for a certain slip angle.

Further: in the feed port or guide hole or silk passageway, place by material silk resistance structure, this structure is: the elastic sheet is clamped, and the elastic material is provided with small holes or openings smaller than the diameter of the material wire.

The invention has the beneficial effects that:

the pushing force is huge and stable, the flow of the nozzle is greatly increased, and 2-way feeding only uses a single motor.

[ description of the drawings ]

Fig. 1 is a schematic view of the structure and the working principle of a pushing gear.

Figure 2 is a schematic diagram of a planetary gear switching dual tone applicator.

FIG. 3 is a schematic of an extruder with a planetary gear switching dual color feeder.

FIG. 4 is a schematic view of the contact between the washer and the sun gear or the planetary pusher gear.

The attached drawings are marked as follows:

in the figure: 1. the device comprises fixed material pushing gears 1 and 2, fixed material pushing gears 2 and 3, a motor shaft and a sun shaft, 4, a sun gear, 5, a planetary material pushing gear, 6, a friction plate, 7, a planetary support, 8, a planetary shaft, 9, a material driving tooth structure 1 and 10, a material driving tooth structure 2 and 11, a spring, 12, a feed hole space, 13, a structural plate, 14, a material feeding motor, 15, a material wire, 16, a gasket, 17, a nozzle, 18, a spring hinge support, 19, a hinge shaft of the spring hinge support, 20, a throat material guide pipe, 21, a fixed shaft, 22, a heating aluminum block, 23, a heating resistor, 24, a contact protrusion, 25, a material driving tooth structure 1 and 26, a material driving tooth structure 2 and 27, a feed hole, 28, a material guide hole and material conveying hose clamp, 29, mutually driving tooth structures, 30, an axial view, 31, a sun shaft hole, 32, a feeding devices and an enlarged view, 33, a heat radiator, 34. slide hole, 35 slide block, 36, 37 extruding material wire, 38 axis

[ example of embodiment ]

The invention is further described in the following preferred embodiments with reference to the accompanying drawings in which:

as shown in fig. 1:

referring to the explanation of fig. 3 and 2, it can be seen that: the pushing gear comprises a planetary pushing gear (1) and a fixed pushing gear (2), the axes of the planetary pushing gear and the fixed pushing gear are axial lines (38), and the axial lines of the planetary pushing gear and the fixed pushing gear (2) are respectively combined with a planetary shaft (8) and a fixed shaft (21); the material driving tooth part structures 1 and 25 and the material driving tooth part structures 2 and 26 are respectively arranged along the axial direction of the material pushing gear, the structures are crescent-shaped material driving teeth, the protruding height of the teeth is relatively shallow, and the contact area of the teeth and the material wires is increased.

The graph enclosed by the dashed line on the right in fig. 1 is an axial view (30), and it can be seen that: when the tooth parts (29) (protruding parts) are mutually and tightly meshed, the gaps between the tooth parts with smaller diameters of the planetary pushing gear and the fixed pushing gear cannot allow the material wire (15) to smoothly pass through (the section between the minimum gaps (a plane determined by the axis of the gear 2), and the diameter of an inscribed circle of the tooth parts is smaller than that of the material wire); the teeth with smaller diameter are used for clamping the wire, and the teeth (29) are mutually driven to meet the meshing state while force is loaded on the wire.

As shown in fig. 2:

FIG. 2 (32) shows a feeding device and an enlarged view; a motor shaft and a sun shaft (3) of a feeding motor (14) fixed on the structural plate (13) drive a sun gear (4) to freely rotate relative to a sun shaft hole (31); under the constraint of the planet support (7), the planet pushing gear (5) rotates around the planet shaft (8), and the planet shaft (8) revolves around the motor shaft and the sun shaft (3); when the motor shaft and the sun shaft (3) rotate clockwise, the friction plate (6) caused by the axial pressure of the spring (11) provides the friction force between the planet support (7) and the gear, the planet support (7) is driven to rotate clockwise, the planet pushing gear (5) is driven to be meshed with the fixed pushing gear (1) and the fixed pushing gear (2), and the material wire (15) is pushed to move upwards to finish feeding; the driving of the material wire (15) is realized by the meshing of the unique structures of the planetary pushing gear and the fixed pushing gear, and the unique structures are as follows: the planetary pushing gear and the fixed pushing gear have the same structure: there are larger diameter gear portions and smaller diameter gear portions arranged along the axial direction; the tooth parts with larger diameters are mutually meshed and used for mutually transmitting power, and the tooth parts with smaller diameters are used for clamping and driving the material wires, so that the planetary pushing gear and the fixed pushing gear are required to have larger diameters; the spring (11) has a (bistable) function, one end of the spring is a fixed fulcrum fixed on the structural plate (13), and the other end of the spring is fixed on a moving fulcrum of the planetary pushing gear (5). The torque of the planet carrier (7) can be obtained no matter the spring is tension or push force; the hinge shaft (19) of the spring anchor causes the spring anchor (18) to anchor the end of the spring and change direction as the planet carrier turns, the post in the center of the spring acting to stabilize the spring against side bending.

The feeding hole (27) is used as a guide hole of the material wire, and rubber sheets with small holes (smaller than the diameter of the material wire) can be placed and filled in the corresponding feeding hole space (12) to play a role in resisting the drawing of the material wire; the material guide hole and material conveying hose clamp (28) is used for locking the material conveying hose.

As shown in fig. 3:

the main structure is the same as that of FIG. 2; a motor shaft and a sun shaft (3) of a feeding motor (14) fixed on the structural plate (13) drive a sun gear (4) to freely rotate relative to the sun shaft hole; under the constraint of the planet support (7), the planet pushing gear (5) rotates around a planet shaft, and the planet shaft revolves around the motor shaft and the sun shaft (3); when the motor shaft and the sun shaft (3) rotate clockwise, the planetary support (7) is driven to rotate clockwise under the action of friction force of the friction plate caused by axial pressure of the spring (11), so that the planetary pushing gear (5) is meshed with the fixed pushing gear (1) and the fixed pushing gear (2) to push the material wires (15) to move upwards to complete feeding; the driving of the material wire (15) is realized by the meshing of the unique structures of the planetary pushing gear and the fixed pushing gear, and the unique structures are as follows: the planetary pushing gear and the fixed pushing gear have the same structure: there are larger diameter gear portions and smaller diameter gear portions arranged along the axial direction; the tooth parts with larger diameters are mutually meshed and used for mutually transmitting power, and the tooth parts with smaller diameters are used for clamping and driving the material wires, so that the planetary pushing gear and the fixed pushing gear are required to have larger diameters; the spring (11) has a (bistable) function, one end of the spring is a fixed fulcrum fixed on the structural plate (13), and the other end of the spring is fixed on a moving fulcrum of the planetary pushing gear (5). The torque of the planet carrier (7) can be obtained no matter the spring is tension or push force; the hinge shaft (19) of the spring anchor causes the spring anchor (18) to anchor the end of the spring and change direction as the planet carrier turns, the post in the center of the spring acting to stabilize the spring against side bending.

The double-color feeder switched by the planet gear feeds the material filaments into a heating aluminum block (22) through a throat material guide pipe (20) and extrudes the material filaments through a nozzle (17); the heating resistor (23) heats the aluminum block, and the temperature sensor senses the temperature of the aluminum block; the heat radiation body (33) keeps the cooling state of the material wires in the material guide pipe (36), and the slide hole (34) on the slide block (35) passes through the horizontal optical axis in the X or Y direction to guide the extruder to run.

As shown in fig. 4:

a contact protrusion (24) is processed on the end surface of the sun gear (4) or the planet pushing gear; contact protrusions (24) are also machined on the opposite end faces of the gasket (16); therefore, when the sun gear (4) or the planet pushing gear rotates oppositely, namely the direction is changed, the contact protrusions can be contacted again only by mutually idling for a certain slip angle.