JP6850431B2 - 3D modeling equipment - Google Patents

Description

The present invention relates to a three-dimensional modeling apparatus.

Conventionally, by extruding a modeling material such as resin from a modeling means and moving it in a two-dimensional direction relatively along a horizontal plane with respect to the mounting table, the modeling material layers are sequentially laminated on the mounting table, and finally. A three-dimensional modeling device for modeling a three-dimensional model is known. Further, in this type of three-dimensional modeling apparatus, in order to improve the bondability, reactivity, adhesion, etc. between thermoplastic materials at the laminated interface, the surface of the modeling material layer formed on the mounting table by the modeling means is discharged. Those provided with a surface modifying means for modifying the surface of the molding material layer by discharging or irradiating with ultraviolet rays are known.

In Patent Document 1, in the above-mentioned three-dimensional modeling apparatus, after the unit layer modeling process for modeling one layer of modeling material by the modeling means is completed, the surface modifying means is moved relative to the mounting table. A surface modification treatment for modifying the surface of the molding material layer is described.

However, in the three-dimensional modeling apparatus described in Patent Document 1, there is a risk that the time required to complete the three-dimensional modeled object will be long.

In order to solve the above problems, the present invention comprises a mounting table, a modeling means for forming a modeling material layer on the mounting table by moving relative to the above-described table while extruding the modeling material, and the above-mentioned. a surface modification means for modifying the surface of the shaped material layer, the surface modification means, and means for relatively moving with respect to the mounting table with said shaping means, Bei example, said surface modification means , The holding means is held by the holding means for holding the modeling means so as to be located on the upstream side in the relative movement direction of the modeling means with respect to the previously described stand, and the holding means is held in a horizontal plane. It is a three-dimensional modeling device characterized by being rotatably provided.

According to the present invention, the modeling time can be shortened.

The schematic front view which shows the internal structure of the 3D modeling apparatus 1 in this embodiment. FIG. 1A is a cross-sectional view taken along the line AA of FIG. Schematic cross-sectional view of the modeling head. A control block diagram showing a part of an electric circuit in a three-dimensional modeling device. Schematic diagram of a cross section showing a unit layer molding operation and a surface treatment operation. Schematic diagram showing the unit layer molding operation and the surface treatment operation. The schematic diagram explaining the state at the time of modeling the long part in the direction inclined with respect to the X-axis direction of the modeling material layer to be modeled. (A) is a schematic view showing a state when the inclined portion is modeled without rotating the rotary table, and (b) shows a state when the rotating table is rotated and the inclined portion is modeled. Pattern diagram. The schematic diagram which shows the example which used the UV lamp as a surface modification apparatus. The perspective view of the straight-line modeled product which is modeled in the verification test 1. The figure explaining the measurement of the interface strength. The graph which shows the relationship between the time from pushing out a filament from a nozzle 21 to irradiating plasma to an interface, and the interface strength.

Hereinafter, an embodiment in which the present invention is applied to a three-dimensional modeling apparatus for modeling a three-dimensional model by the Fused Deposition Modeling (FDM :: Fused Deposition Modeling) method will be described. In the three-dimensional modeling apparatus using the Fused Deposition Modeling method, a long filament made of a resin composition using a thermoplastic resin as a modeling material as a matrix is prepared in advance. This filament is supplied to the modeling head, and the filament is heated in the modeling head to melt or semi-melt the thermoplastic resin of the matrix. Then, after that, the melt or semi-melt is extruded linearly from the tip of the nozzle of the modeling head and gradually piled up to be cooled and solidified. In the Fused Deposition Modeling method, it is possible to form a three-dimensional model in which the mold becomes complicated or cannot be molded by injection molding. The present invention is not limited to the Fused Deposition Modeling Method (FDM), and other modeling methods for modeling a three-dimensional model by sequentially laminating the modeling material layers, and modeling completely different from this. Depending on the method, it can also be applied to a three-dimensional modeling device for modeling a three-dimensional modeled object.

FIG. 1 is a schematic front view showing the internal structure of the three-dimensional modeling apparatus 1 according to the present embodiment, and FIG. 2 is a sectional view taken along the line AA of FIG. Hereinafter, the vertical direction will be described as the Z-axis direction, the left-right direction of the device as the X-axis direction, and the depth direction of the device as the Y-axis direction.

In the three-dimensional modeling apparatus 1, a mounting table 7 is provided in a processing space inside the housing 10, and a three-dimensional modeled object M is modeled on the mounting table 7. A mounting table guide shaft 44 penetrates near both ends of the mounting table 7 in the X-axis direction, and a Z-axis feed screw 42 penetrates near one end of the mounting table 7 in the Y-axis direction. A female screw is formed on the inner peripheral surface of the through hole through which the Z-axis feed screw 42 of the mounting base 7 penetrates, and the mounting base 7 is screwed into the Z-axis feed screw 42.

The lower end of the Z-axis feed screw 42 is connected to the Z-axis drive motor 41 provided on the bottom surface of the housing 10. Further, on the bottom surface of the housing 10, a Z-axis coordinate detection mechanism 43 for detecting the position of the mounting table 7 in the Z-axis direction is provided.

The Z-axis feed screw 42 is rotationally driven by the Z-axis drive motor 41, so that the mounting table 7 screwed into the Z-axis feed screw 42 moves in the Z-axis direction while being guided by the pair of mounting table guide shafts 44. To do. The Z-axis drive motor 41 is controlled based on the detection result of the Z-axis coordinate detection mechanism 43.

Further, it is preferable to provide a table heating unit 400 for heating the mounting table 7 to heat the mounting table 7 to a predetermined temperature. By heating the mounting table 7 to a predetermined temperature, it is possible to prevent the modeling material layer on the mounting table 7 from cooling during modeling. As a result, expansion and contraction due to cooling of the modeling material layer can be suppressed, and occurrence of warpage and the like can be suppressed.

A reel 31 around which a filament 30 which is a modeling material made of a thermoplastic resin such as an elongated wire-shaped ABS resin or PLA resin is wound is rotatably attached to the outer surface of the housing 10. The reel 31 is rotated in a form of being pulled by an extruder 25 that sends out the filament 30, so that the wound filament 30 is unwound.

A modeling module 100 is provided above the mounting table 7 in the processing space. The modeling module 100 is composed of a modeling head 20 as a modeling means, a rotary table 82 as a holding means, a support member 28, and the like.

The modeling head 20 includes an extruder 25 as an introduction part for sending out the filament 30, a cooling block 24 as a cooling part for cooling the filament 30, a heating block 22 for heating and melting the filament 30, and an extrusion part for extruding the melted filament 30. The nozzle 21 and the like are provided. In the present embodiment, the molten filament 30 is ejected from the nozzle 21 so as to be extruded, so that the modeling material layers are sequentially laminated on the mounting table 7 to form a three-dimensional modeled object.

In this embodiment, two modeling heads 20 are provided side by side in the Y-axis direction, and are integrated except for the nozzles of the modeling heads. The modeling head 20 is held by the rotary table 82, and the rotary table 82 is rotatably attached to the support member 28.

Of the two modeling heads, the nozzle of one modeling head discharges the molten filament of the model material constituting the three-dimensional model, and the nozzle of the other modeling head ejects the molten filament of the support material. .. The support material is usually formed of a material different from the filament of the model material that constitutes the 3D model, and is finally removed from the 3D model. The filaments of the support material discharged from the other nozzle are also sequentially laminated in layers like the filaments of the model material.

Further, on the rotary table 82, two electrodes 81 of the atmospheric pressure plasma radiating device, which is a surface modifying means and a plasma radiating means, are held side by side in the X-axis direction (direction orthogonal to the arranging direction of the nozzles 21). Has been done. The rotary table 82 is rotatably provided on the support member 28. A table rotation motor 83 for rotating the rotary table 82 is attached to the support member 28. For example, external teeth are formed on the outer peripheral surface of the rotary table 82, and the motor gear 83a of the table rotary motor 83 meshes with the external teeth of the rotary table 82. As a result, the driving force is transmitted from the table rotation motor 83, and the rotary table 82 rotates.

An X-axis guide shaft 54 extending in the X-axis direction and an X-axis feed screw 52 penetrate through the support member 28. A female screw is formed on the inner peripheral surface of the through hole through which the X-axis feed screw 52 of the support member 28 penetrates, and the support member 28 is screwed into the X-axis feed screw 52.

A Y-axis guide shaft 64 is provided at one end in the X-axis direction (left side in the figure) of the upper part of the housing, and a Y-axis feed screw 62 is provided at the other end in the X-axis direction (right side in the figure) of the upper part of the housing. It is provided. A guided member 66 is attached to the Y-axis guide shaft 64 so as to be movable in the Y-axis direction, and a moving member 65 is screwed to the Y-axis feed screw 62. The guided member 66 holds one end of the X-axis guide shaft 54 and the X-axis feed screw 52. The X-axis feed screw 52 is rotatably held by the guided member 66. The moving member 65 holds the other end of the X-axis guide shaft 54, the X-axis drive motor 51, and the X-axis coordinate detection mechanism 53 that detects the position of the modeling module 100 in the X-axis direction. The other end of the X-axis feed screw 52 is connected to the X-axis drive motor 51. As a result, the support member 28 that supports the modeling head 20 and the like is held by the Y-axis feed screw 62 and the Y-axis guide shaft 64 so as to be bridged by the X-axis guide shaft 54 and the X-axis feed screw 52.

Further, one end of the Y-axis feed screw 62 is rotatably supported by the feed screw holding portion 61a, and the other end is connected to the Y-axis drive motor 61 attached to the side surface of the housing 10. A Y-axis coordinate detection mechanism 63 that detects the position of the modeling module 100 in the Y-axis direction is attached to the lead screw holding portion 61a.

When the Y-axis feed screw 62 is rotationally driven by the Y-axis drive motor 61, the moving member 65 screwed into the Y-axis feed screw 62 moves in the Y-axis direction. As a result, the modeling module 100 held by the moving member 65 via the X-axis guide shaft 54 and the X-axis feed screw 52 moves in the Y-axis direction while being guided by the Y-axis guide shaft 64. The Y-axis drive motor 61 is controlled based on the detection result of the Y-axis coordinate detection mechanism 63.

Further, the X-axis feed screw 52 is rotationally driven by the X-axis drive motor 51, so that the modeling module 100 is guided by the X-axis guide shaft 54 together with the support member 28 screwed to the X-axis feed screw 52 in the X-axis direction. Move to. The X-axis drive motor 51 is controlled based on the detection result of the X-axis coordinate detection mechanism 53.

Further, a nozzle cleaning unit 70 for cleaning the nozzle 21 of the modeling head 20 is provided in the housing 10. If the melt discharge of the filament 30 is continued over time, the periphery of the nozzle may become dirty due to the dripping of the filament from the nozzle 21 and the residual filament adhering to the nozzle 21, which may hinder an appropriate discharge operation. Therefore, it is necessary to clean the nozzle regularly.

The nozzle cleaning unit 70 is provided at one end of the mounting table 7 in the X-axis direction, and mainly includes a brush 71 for removing foreign substances such as residual filaments of the nozzle 21, a brush motor 72 for rotating the brush 71, and a brush. A collection box 73 for collecting the foreign matter removed by 71 is provided.

To clean the nozzles, the mounting table 7 and the modeling module 100 are moved so that the nozzles 21 come into contact with the brush 71. Then, the brush 71 is rotated by the brush motor 72 to remove foreign substances such as residual filaments adhering to the nozzle 21. Preferably, it is better to clean the residual filament adhering to the nozzle before the temperature is completely lowered from the viewpoint of sticking. In that case, it is preferable to use a heat-resistant resin for the brush 71. The foreign matter removed from the nozzle 21 falls into the collection box 73 and is collected in the collection box 73. The collection box 73 is detachably provided with respect to the mounting table 7. The collection box 73 is removed from the mounting table 7, and the foreign matter collected in the collection box 73 is periodically discarded. In the present embodiment, the collection box 73 is provided inside the housing, but the foreign matter removed from the nozzle 21 by the brush 71 is transported to the collection box 73 provided outside the housing by, for example, a suction machine. You may try to do it.

FIG. 3 is a schematic cross-sectional view of the modeling head 20.
The modeling head 20 includes an extruder 25 for supplying the filament 30, a cooling block 24 for cooling the filament 30, a heating block 22 for heating and melting the filament 30, a nozzle 21 for discharging the molten filament 30, and the like. Further, between the cooling block 24 and the heating block 22, there is a guide block 23 that guides the filament 30 that has passed through the cooling block 24 to the heating block 22. A transfer path 26 for transferring the filament 30 introduced from the extruder 25 to the nozzle 21 is formed in the heating block 22, the guide block 23, and the cooling block 24, respectively.

The heating block 22 includes a heat source 22a, which is a heating unit for heating the filament 30, and a thermocouple 22b, which is a temperature detection unit for detecting the temperature of the filament 30 heated by the heat source 22a. The thermocouple 22b is arranged on the side opposite to the side where the heat source 22a is arranged with the transfer path 26 to which the filament 30 is transferred. The heating block 22 heats the filament 30 in the transfer path 26 to bring it into a molten state, and the molten filament 30a in the molten state is transferred to the nozzle 21.

The heat from the heating block 22 propagates not only to the filament 30 in the transfer path 26 but also to the upstream side of the filament 30 in the transfer direction. However, the filament 30 at a position distant from the transfer path in the heating block 22 to the upstream side in the transfer direction is heated and melted. When the heat treatment by the heating block 22 is stopped or interrupted, the molten filament 30 solidifies in the transfer path 26. After that, when the heat treatment by the heating block 22 is restarted, the solidified filament in the transfer path of the heating block 22 is immediately remelted, but at a position separated from the transfer path in the heating block 22 on the upstream side in the transfer direction. The solidified filament takes time to remelt. As a result, the filament 30 fed by the extruder 25 cannot be transferred to the nozzle 21 and becomes clogged. Therefore, the heating range of the filament 30 by the heating block 22 should not be expanded as much as possible to the upstream side in the filament transfer direction so that the adhered filament can be quickly remelted after the heat treatment by the heating block 22 is restarted. is important.

Therefore, the cooling block 24 is provided on the upstream side of the heating block 22 in the filament transfer direction. The cooling block 24 is made of a highly heat-conducting material such as aluminum, and a flow path 24a through which the refrigerant flows is provided around the transfer path 26 of the cooling block 24. The cooling block 24 transfers the heat of the filament 30 in the transfer path 26 to the refrigerant flowing in the flow path 24a and cools the block 24. As a result, it is possible to prevent the filament 30 at a position separated from the transfer path in the heating block 22 on the upstream side in the transfer direction from being heated by the heating block 22 and melting.

The guide block 23 arranged between the heating block 22 and the cooling block 24 is made of a heat insulating material and suppresses the heat of the heating block 22 from propagating upstream in the filament transfer direction. As a result, the filament 30 at a position separated from the transfer path in the heating block 22 on the upstream side in the transfer direction can be further suppressed from being heated and melted by the heating block 22. In addition, the heat transfer of the heating block 22 is suppressed, and the filament in the good heating block 22 transfer can be heated.

The extruder 25 is provided with a pair of feed rollers 25a, and the filament 30 is fed into the transfer path 26 by the feed rollers 25a. The molten filament 30a heated and melted by the heating block 22 is discharged from the nozzle 21 by the feeding force of the extruder 25.

In the present embodiment, the extruder 25 of one modeling head 20 and the extruder 25 of the other modeling head 20, the cooling block 24 of one modeling head 20 and the cooling block 24 of the other modeling head 20, and the guide of one modeling head 20. The block 23 and the guide block 23 of the other modeling head 20, the heating block 22 of one modeling head 20 and the heating block 22 of the other modeling head 20 constitute one modeling head 20 as shown in FIG. Is integrated into.

FIG. 4 is a control block diagram showing a part of an electric circuit in the three-dimensional modeling apparatus 1.
The control device 200, which is a control means, is composed of a CPU (Central Processing Unit) 402, which is a calculation means, a RAM (Random Access Memory) 404, which is a data storage means, a ROM (Read Only Memory) 406, a non-volatile memory 408, and the like. Then, various arithmetic processes and control program execution can be performed.

Reference numeral 90 in the figure is a drive unit, and the drive unit 90 is an X-axis, Y-axis, Z-axis drive motor 41, 51, 61, a table rotation motor 83, an X-axis, a Y-axis, and a Z-axis coordinate detection mechanism 43. , 53, 63, etc. Further, reference numeral 80 in the figure is an atmospheric pressure plasma radiating device serving as a surface modification means, and the atmospheric pressure plasma radiating device 80 is composed of a surface treatment device power supply 85, electrodes 81 and the like.

The control device 200 includes a data generation unit 201, a heating temperature control unit 202, an extrusion amount control unit 203, a drive control unit 204, a surface treatment control unit 205, and the like. The data generation unit 201 is divided into a large number in the vertical direction based on the modeled object data input from an external device such as a personal computer connected to the three-dimensional modeling device 1 so as to be able to perform data communication by wire or wirelessly. Generate modeling material layer data (slice data for modeling). The slice data corresponding to each modeling material layer corresponds to each modeling material layer formed by the filament 30 extruded from the modeling head 20 of the three-dimensional modeling apparatus 1, and the thickness of the modeling material layer is three-dimensional. It is appropriately set according to the capacity of the modeling device 1. Further, the slice data may be generated by an external device, and the slice data may be input to the three-dimensional modeling device 1.

The slice data is text data with an extension of ".gcode" called G-code, and ".gcode" is basically 1. Data of vertex coordinates of the modeled object, 2. Velocity data moving to each vertex, 3. It is composed of three points of velocity data for sending out the filament. Above 3. The speed data for feeding the filament includes data on the feed start timing and the feed stop timing. In addition to the above, the data generation unit 201 generates heating temperature data, ON / OFF timing data of the surface treatment device power supply, and the like.

The heating temperature data is transmitted to the heating temperature control unit 202. The heating temperature control unit 202 feedback-controls the heat source 22a of the heating block 22 based on the detection result detected by the thermocouple 22b so that the heating temperature becomes the heating temperature sent from the data generation unit 201.

Further, in order to ensure the temperature stability of the tip nozzle, the heating temperature control unit 202 starts the operation before the start of the filament feeding operation, and is heated to the above heating temperature at the start of the filament feeding operation. preferable. Specifically, the feedforward control for controlling the heat source 22a is performed by predicting the filament feeding operation start timing based on the data for starting the feeding of the filament 30 and the data for the apex coordinates of the modeled object. Further, feedback control may be performed to start the modeling operation when the thermocouple 22b detects that the heating temperature has reached the above heating temperature.

G-code 3. The speed data for feeding the filament is sent to the extrusion amount control unit 203. The extrusion amount control unit 203 controls the extruder 25 so as to be the filament feed rate sent from the data generation unit 201. Further, it is preferable that the extrusion amount control unit 203 performs a suction operation of drawing in the filament 30 by rotating the extruder 25 in the reverse direction before stopping the ejection of the filament 30 from the nozzle 21 (before stopping the drive of the extruder 25). By performing such an operation, it is possible to suppress the dripping of the filament from the nozzle 21, and it is possible to improve the shape accuracy of the modeled object.

G-code above 1. Data of vertex coordinates of the modeled object, 2. The velocity data moving to each of the vertices is sent to the drive control unit 204. The drive control unit 204 is described in 1. above, which is sent from the data generation unit 201. Data of vertex coordinates of the modeled object, 2. Each drive motor 41, 51, 61, 83 is controlled based on the speed data moving to each of the vertices. Further, the drive control unit 204 performs feedback control for moving to the target coordinate point based on the detection results of the coordinate detection mechanisms 43, 53, 63 so as not to cause an operation defect.

The ON / OFF timing data of the surface treatment device power supply is sent to the surface treatment control unit 205. The surface treatment control unit 205 controls ON / OFF of the surface treatment device power supply 85 based on the ON / OFF timing data sent from the data generation unit 201.

The extrusion amount control unit 203 is synchronized with the drive control unit 204, and the extrusion amount (feed speed) of the filament 30 and the feed start / stop of the filament 30 are controlled according to the movement of the modeling head 20. .. Further, the surface treatment control unit 205 is also synchronized with the drive control unit 204, and ON / OFF of the surface treatment device power supply 85 is controlled according to the movement of the modeling head 20.

When the modeling is started by a user's instruction operation or the like, first, the energization of the heat source 22a of the heating block 22 is turned on, and the heating is heated to the heating temperature generated by the data generation unit 201 based on the modeled object data. Further, the drive control unit 204 controls the Z-axis drive motor 41 to raise the mounting table 7 from a predetermined standby position (for example, the lowest point) and move it to the modeling position.

When the Z-axis coordinate detection mechanism 43 detects that the mounting table 7 has reached the modeling position, the Z-axis drive motor 41 is stopped and the process proceeds to the modeling process. In the modeling process, first, the bottom layer of the modeling material is created on the surface of the mounting table 7 based on the slice data of the bottom layer (first layer). Specifically, based on the slice data of the lowest layer (first layer), the detection result of the X-axis coordinate detection mechanism 53, and the detection result of the Y-axis coordinate detection mechanism 63, the drive control unit 204 drives the X-axis drive motor 51. And the Y-axis drive motor 61 is controlled to sequentially move the tip of the nozzle 21 of the modeling head 20 to the target position (target position on the XY plane). Further, in synchronization with the drive control of the drive control unit 204, the extrusion amount control unit 203 controls the extruder 25 based on the slice data to extrude the filament 30 from the nozzle 21. As a result, the filament is ejected from the nozzle 21 while sequentially moving the tip of the nozzle 21 of the modeling head 20 to the target position, and the modeling material layer is placed on the mounting table 7 according to the slice data of the lowest layer (first layer). Is formed. A support material that does not constitute a three-dimensional model may also be created, but the description here will be omitted.

When the modeling process (unit layer modeling operation) of the modeling material layer according to the slice data of the lowest layer (first layer) is completed, the drive control unit 204 drives the Z-axis based on the detection result of the Z-axis coordinate detection mechanism 43. The motor 41 is controlled to lower the mounting table 7 by a distance corresponding to one layer of the modeling material layer. After that, the X-axis drive motor 51 and the Y-axis drive motor 61 are controlled by the drive control unit 204 based on the slice data of the second layer, and the tip of the nozzle 21 of the modeling head 20 is sequentially moved to the target position. At the same time, the extruder 25 is controlled by the extrusion amount control unit 203 to discharge the filament 30 from the nozzle 21. As a result, a modeling material layer according to the slice data of the second layer is formed on the modeling material layer of the lowest layer formed on the mounting table 7.

In this way, while controlling the Z-axis drive motor 41 and sequentially lowering the mounting table 7, the unit layer modeling operation in which the modeling material layers are laminated in order from the lower layer is repeated, and the three-dimensional modeling data is followed. The three-dimensional modeled object is modeled on the mounting table 7. When the three-dimensional modeled object is modeled, the Z-axis drive motor 41 is controlled to lower it to the standby position.

In the present embodiment, the atmospheric pressure plasma radiating device 80 is provided, and by irradiating the surface of the modeling material layer of the mounting table 7 with plasma to modify the surface of the modeling material layer, adhesion at the interface between the layers is performed. The force is increased, and the strength in the stacking direction of the three-dimensional model is increased.

The three-dimensional modeling apparatus 1 for modeling a three-dimensional model by the Fused Deposition Modeling method has a problem that the strength in the lamination direction is extremely low. Specifically, when modeling various three-dimensional objects, it takes time from the first layer to the second layer when modeling a large object, and that time is particularly free. The results showed that the molding (peeling) strength was extremely low at the site. The strength in the stacking direction is affected by the compatibility state of the resin. For example, when time elapses after the first layer is formed, the temperature of the molten resin drops, and even if the second layer is formed on the first layer, the first and second layers are formed at the interface. The temperature will be incompatible with.

As a countermeasure against the problem of low strength in the stacking direction, it is conceivable to raise the temperature of the molten filament 30a extruded from the nozzle 21, but if the temperature of the molten filament 30a is raised, the molding accuracy is lowered. This is because raising the temperature causes a decrease in the viscosity of the molten filament 30a discharged from the nozzle 21. As a result, the modeling material layer cannot maintain a desired shape in a form that cannot withstand the shearing force applied from the nozzle 21 when ejecting from the nozzle 21.

It is also conceivable to suppress the decrease in strength in the stacking direction by increasing the molding speed and suppressing the decrease in the lower layer temperature to some extent. However, the modeling speed depends on the size of the modeled object, and in addition, there is a problem that the viscoelasticity of the molten filament 30a discharged from the nozzle 21 decreases in proportion to the modeling speed. Further, when the molding speed is increased, the shear stress in the molten filament extruded from the nozzle 21 increases, and the resin orientation strongly appears in the skin layer on the surface, so that there is a concern that the anisotropy of the material is further increased. As described above, in the Fused Deposition Modeling method, there is a trade-off between the strength in the stacking direction, the molding accuracy, and the speed (modeling time).

The forces that are the source of the adhesion at the interface between layers are generally 1. 2. The force with which the diffused molecular chains are entangled with each other due to molecular diffusion by compatibility. 3. Mechanical bonding force obtained from the anchor effect obtained from the surface roughness at the interface. Intermolecular force at the interface, 4. Examples include the force obtained by chemically bonding the functional groups on each surface. Above 1. As mentioned above, increasing the force with which the diffused molecular chains are entangled with each other due to molecular diffusion by compatibility is due to the limitation of the nozzle trajectory (hereinafter abbreviated as tool path), various types including temperature. It is extremely difficult to keep the process conditions in-plane (in-layer) constant.

In the present embodiment, the atmospheric pressure plasma radiating device 80 irradiates the interface of the layer with plasma to cut the molecular chain of the interface and cause a functional group to appear at the interface of the lower molding material layer. As a result, the functional group at the interface of the lower modeling material layer and the functional group of the upper modeling material layer laminated on this interface are chemically bonded to increase the adhesive force at the interface between the layers and increase the strength in the stacking direction. Can be enhanced. Further, by cutting the molecular chain at the interface of the lower molding material layer, hydrophilic functional groups such as a hydroxyl group and a carboxyl group appear at the interface. As a result, the wettability of the interface of the lower modeling material layer can be enhanced, and the adhesion with the upper modeling material layer laminated at the interface of the lower modeling material layer can be further enhanced.

FIG. 5 is a schematic cross-sectional view showing a modeling operation and a surface treatment operation, and FIG. 6 is a schematic plan view showing a unit layer modeling operation and a surface treatment operation.
As shown in FIGS. 5 and 6, plasma is irradiated from the electrode 81 on the upstream side of the nozzle 21 in the modeling head moving direction (direction of arrow A in the figure) of the two electrodes 81. As a result, the surface of the filament immediately after being extruded from the nozzle is irradiated with plasma, and the interface of the modeling material layer (upper modeling material layers m2 and s2 in FIGS. 5 and 6) is modified. In the present embodiment, the electrode 81 is arranged at the center between the two nozzles in the nozzle arrangement direction. As a result, as shown in FIG. 6, the interface between the model material modeling material layer (m1 and m2) formed by the filament of the model material and the support material modeling material layer (s1 and s2) formed by the filament of the support material. Plasma can be applied to the interface between the two. Therefore, it is possible to modify the interface of the model material modeling material layer and the interface of the support material modeling material layer with one electrode. The support material modeling material layer is for supporting the model material modeling material layer. Therefore, if the adhesion at the interface between the layers of the support material shaping material layer is weak, the model material shaping material layer may not be supported satisfactorily. As in the present embodiment, the interface of the support material modeling material layer is also surface-modified to increase the adhesion at the interface between the layers, so that the model material modeling material layer can be satisfactorily supported and the modeling accuracy is improved. Can be done.

Plasma irradiation from the electrode 81 is started after a predetermined time has elapsed from the start of driving the extruder 25. As shown in FIG. 6, the specified time can be obtained from (distance L from the tip nozzle to the maximum irradiation region of the plasma irradiation region S in the movement direction of the modeling head 20) / (moving speed of the modeling head 20). .. Further, after the drive of the extruder 25 is stopped and the above-mentioned specified time elapses, the plasma irradiation is stopped. The data generation unit 201 described the above 2. of the generated G-code. Velocity data moving to each apex of the modeled object, 3. The ON / OFF timing data of the surface treatment device power supply is created based on the speed data of sending out the filament and the like.

In addition, when the layers to be modeled are switched, or when the modeling material layers are separated like a remote island, the surface treatment device is stopped to partially stop the atmospheric pressure plasma from the electrodes. Avoid concentrating surface irradiation on the surface.

In the present embodiment, the electrode 81 of the atmospheric pressure plasma radiating device 80 is held by a member (rotary table 82 in the present embodiment) in which the modeling head 20 is held, and is configured to move together with the modeling head 20. Has been done. As a result, the surface modification treatment by the atmospheric pressure plasma radiating device 80 can be performed while modeling the modeling material layer by the modeling head. As a result, the completion time until the three-dimensional structure is completed is compared with the one in which the atmospheric pressure plasma radiating device 80 is moved to modify the surface of the modeling material layer after the modeling material layer is formed by the modeling head 20. Can be shortened.

Further, since the electrode 81 is arranged in the vicinity of the nozzle 21 of the modeling head 20, the surface of the filament can be irradiated with plasma within a predetermined time by being extruded from the nozzle to modify the interface of the modeling material layer. ..

FIG. 12 is a graph showing the relationship between the time from pushing the filament out of the nozzle 21 to irradiating the interface with plasma and the interface strength.
As shown in FIG. 12, the shorter the time from when the filament is extruded from the nozzle 21 of the modeling head 20 to when the filament is irradiated with plasma, the stronger the strength at the interface between the modeling layers can be improved. By setting the time from the extrusion of the filament from the nozzle 21 of the modeling head 20 to the plasma irradiation within 50 seconds, the interfacial strength can be made 0.3 N / mm or more, which is preferable. As in the present embodiment, the electrode 81 is held by the member (rotary table 82) in which the modeling head 20 is held, the electrode 81 is arranged in the vicinity of the nozzle 21 of the modeling head 20, and the electrode 81 is moved together with the modeling head 20. By doing so, the surface of the filament can be irradiated with plasma within a predetermined time (50 seconds) by being pushed out from the nozzle 21 without changing the positional relationship between the nozzle 21 and the electrode 81. As a result, the interface of the molding material layer can be modified within a predetermined time (50 seconds), which is preferable. Further, the interfacial strength can be made larger than 0.4 N / mm by setting the predetermined time within 20 seconds, which is more preferable. The interfacial strength was measured by the same method as in the verification test 1 described later.

FIG. 7 is a schematic view illustrating a state when a long modeling material layer is formed in a direction inclined with respect to the X-axis direction.
For example, as shown by the dotted line in FIG. 7, when forming a long molding material layer mk in a direction inclined by 45 ° with respect to the X-axis direction, the X-axis drive motor 51 and the Y-axis drive motor 61 are driven. Then, as shown by the arrow C in the figure, the modeling module 100 is moved in a direction inclined by 45 ° with respect to the X-axis direction. By moving the modeling module 100 in this way, the modeling accuracy can be improved and the modeling time can be shortened as compared with the case where the modeling material layer mk is formed by reciprocating in the X-axis direction. Can be planned. Further, by modeling a portion of the housing 10 of the three-dimensional modeling apparatus 1 that is longer than the X-axis or Y-axis direction along a direction inclined by 45 ° with respect to the X-axis direction, the X-axis or the housing 10 is formed. A three-dimensional modeled structure having a portion longer than the Y-axis direction can be modeled inside the housing 10.

Further, in the present embodiment, before moving the modeling module 100 in the direction of arrow C in the drawing, the table rotation motor 83 is driven to rotate the rotary table 82 holding the modeling head 20 and the electrodes 81 by 45 °. As a result, the nozzles 21 are arranged in a direction orthogonal to the moving direction of the modeling module 100 (direction of arrow C in the drawing), and the electrodes 81 are arranged in the moving direction of the modeling module 100.

FIG. 8A is a schematic view showing a state when a modeling material layer mk inclined with respect to the X-axis direction is formed without rotating the rotary table 82, and FIG. 8B is a rotary table. It is a schematic diagram which shows the state when the modeling material layer mk inclined with respect to the X-axis direction is formed by rotating 82.
As shown in FIG. 8A, when the modeling material layer mk inclined with respect to the X-axis direction is formed without rotating the rotary table 82, a part of the support material discharged from one nozzle and the other A part of the model material discharged from the nozzle overlaps. As a result, after modeling the three-dimensional modeled object, the support material may not be removed well, or a recess may be formed in the three-dimensional modeled object. Therefore, the support material and the model material cannot be discharged at the same time, and the molding time becomes long. Further, when plasma irradiation is performed while modeling the modeling material layer mk inclined in the X-axis direction, plasma cannot be irradiated to the entire interface of the modeling material layer mk of the model material, and the modeling material is modeled. The entire interface of the material layer mk cannot be modified.

On the other hand, as shown in FIG. 8B, the nozzles 21 are arranged in a direction orthogonal to the moving direction of the modeling module 100 (direction of arrow C in the figure), and the electrodes 81 are arranged in the moving direction of the modeling module 100. By rotating the rotary table 82, even if the support material and the model material are discharged at the same time, the support material and the model material do not overlap. As a result, even if the support material and the model material are discharged at the same time, there is no possibility that the support material cannot be removed well or a recess is formed in the three-dimensional modeled object. Thereby, in the modeling of the modeling material layer mk inclined with respect to the X-axis direction, the support material modeling material layer sk and the model material modeling material layer mk can be simultaneously modeled. As a result, the modeling time can be shortened. Further, even if plasma irradiation is performed while forming the modeling material layer mk inclined in the X-axis direction, plasma is applied to the entire interface of both the support material modeling material layer sk and the model material modeling material layer mk. Can be irradiated. As a result, the surface can be modified while forming the modeling material layer mk inclined in the X-axis direction.

Further, when forming a modeling material layer long in the Y-axis direction, the rotary table 82 is rotated by 90 ° from the state shown in FIG. 2, and then the Y-axis drive motor 61 is driven to drive the modeling module 100 on the Y-axis. It is moved in the direction to form a long molding material layer in the Y-axis direction.

Further, in the present embodiment, two electrodes are provided at an interval of 180 ° in the rotation direction of the rotary table 82. As a result, the rotation angle of the rotary table 82 can be reduced as compared with the case where one electrode is provided. For example, the modeling module 100 is moved in the + X-axis direction to form a portion of the modeling material layer extending in the X-axis direction, then moved by a predetermined distance in the Y-axis direction, and the modeling module 100 is moved in the −X-axis direction. When forming parts of the modeling material layer extending in the X-axis direction at different positions in the Y-axis direction, if there is only one electrode, rotate the rotary table 180 ° to move the electrode to the modeling module rather than the nozzle. It must be located upstream in the direction.

On the other hand, when two electrodes are provided with an interval of 180 ° in the rotation direction of the rotary table 82 as in the present embodiment, any of the two electrodes can be provided without rotating the rotary table 82. One of them is located upstream of the nozzle 21 in the direction of movement of the modeling module. Therefore, it is not necessary to rotate the rotary table 82 when the modeling module 100 is moved in the + X-axis direction for modeling and then the modeling module 100 is moved in the −X-axis direction for modeling. As a result, the molding time can be shortened as compared with the case where there is only one electrode.

Further, plasma may be radiated from an electrode on the downstream side in the moving direction of the modeling module to surface-modify the interface of the lower modeling material layer immediately before the molten filament 30a extruded from the nozzle 21 is laminated. In such a configuration, since plasma is irradiated to the interface in a cold state, the surface modification effect is low, but the adhesion of the interface can be enhanced as compared with the case where the surface is not modified.

Further, by holding the electrode 81 on the same member (rotary table 82 in this embodiment) as the member on which the modeling head 20 is held, the following advantages can be obtained. That is, in the modeling by FDM, the distance between the tip of the nozzle 21 of the modeling head 20 and the modeling material layer on the mounting table 7 is always kept constant. Therefore, by holding the electrode 81 in the same member as the member in which the modeling head 20 is held, the distance between the tip of the electrode 81 and the modeling material layer is always kept constant. As a result, the plasma irradiation range of the electrode 81 can be kept constant at all times, plasma can be satisfactorily irradiated to the entire interface of the modeling material layer, and the interface of the modeling material layer can be uniformly modified.

Further, by holding the electrode 81 in the same member as the member in which the modeling head 20 is held, the electrode 81 can be moved by means for moving the modeling head 20. As a result, the cost of the apparatus can be reduced as compared with the case where the means for moving the modeling head 20 and the means for moving the electrodes 81 are separately provided.

FIG. 9 is a schematic view showing an example in which a UV lamp 181 as an ultraviolet irradiation means is used as a surface modification means for modifying the interface of the modeling material layer. 9 (a) is a schematic view seen from the Y-axis direction, FIG. 9 (b) is a schematic view seen from the X-axis direction, and FIG. 9 (c) is a schematic view seen from the Z-axis direction. ..
The UV lamp 181 is a long straight tube type and is held by a bracket 182 provided on the rotary table 82. As the UV lamp 181, any ozone-free type that mainly emits a wavelength of 254 nm, a low-pressure mercury lamp, an excimer lamp, and other ozone-generating types can be used. The rotary table 82 is attached to the modeling head 20, and the modeling head 20 is rotatably attached to the support member 28.

In the configuration shown in FIG. 9, unlike the pen-type atmospheric pressure plasma radiating device, UV light cannot be spotted only on the interface of the modeling material layer immediately after being extruded from the nozzle 21 and formed. Therefore, in FIG. 9, depending on the shape of the modeling material layer, there is an interface that is irradiated with UV light multiple times.

Also in the configuration shown in FIG. 9, the rotary table 82 is rotated so that the UV lamp 181 is located upstream of the nozzle 21 in the moving direction of the modeling module 100 before the start of the modeling operation. Then, the molten filament 30a extruded from the nozzle 21 on the interface of the mounting table 7 or the modeling material layer of the mounting table 7 is irradiated with ultraviolet rays by the UV lamp 181 to cut the molecular chain at the interface of the modeling material layer. As a result, the functional groups of the upper modeling material layer laminated at the interface of the modeling material layer are chemically bonded to each other, the adhesion force at the interface between the layers can be increased, and the strength in the stacking direction can be increased. Further, by cutting the molecular chain at the interface of the modeling material layer, hydrophilic functional groups such as a hydroxyl group and a carboxyl group appear at the interface. As a result, the wettability of the interface of the lower modeling material layer can be enhanced, and the adhesion with the upper modeling material layer laminated at the interface of the lower modeling material layer can be further enhanced.

Next, the verification test conducted by the applicant will be described.

[Verification test 1]
In the verification test 1, the interfacial strength between the case where the surface was modified and the case where the surface was not modified was verified.

[Comparative Example 1]
In Comparative Example 1, ABS resin was used for the filament 30 which is a modeling material. The size and shape of the filament 30 was a rod shape of φ2.0 mm. As the extruder 25 of the modeling head 20, an extruder having a φ12 mm SUS304 pair feed roller was used. The nozzle 21 was made of brass and had an opening diameter of 0.5 mm at the tip. The portion to be the transfer path 26 is made to be a cavity having a diameter of 2.5 mm. The cooling block 24 was made of SUS304, passed through a water cooling pipe, and connected to a chiller. The set temperature of the chiller was 10 ° C. The heating block 22 was also made of SUS304 like the cooling block 24, passed through a cartridge heater as a heat source, and a thermocouple was arranged on the side symmetrical with the filament to control the temperature. The set temperature of the cartridge heater was 230 ° C. The three-dimensional model to be modeled was a linear model Ms composed of two layers of modeling material as shown in FIG. 10, and the scanning speed of the nozzle during modeling was 10 mm / sec. In addition, the set temperature of the mounting table 7 was set to 130 ° C. The thickness (length in the Z-axis direction) of the modeling material layer, which directly affects the resolution in the stacking direction of the modeled object, was set to 0.3 mm.

[Comparative Example 2]
Comparative Example 2 had the same configuration and settings as Comparative Example 1 except that the scanning speed of the nozzle during modeling was 50 mm / sec.

[Example 1]
In Example 1, the pen-shaped electrode of the atmospheric pressure plasma radiating device was held on a rotary table as a surface treatment device, and plasma was irradiated to the interface of the modeling material layer immediately after being extruded from the nozzle, as compared with Comparative Example 1. The same configuration and settings were used. The electrode to be the pen tip was positioned so that the gap to the interface of the modeling material layer to be irradiated was 2.5 mm. The frequency of 20 KHz was set for the high frequency power supply as the power supply for the surface treatment device that applies voltage to the electrodes. As the nozzle scans the toolpath (the preset path of nozzle movement), the electrodes are programmed to rotate the rotary table so that they are located upstream of the nozzle in the nozzle movement direction and are extruded from the nozzle. It was made possible to irradiate the interface of the molding material layer immediately after the nozzle with plasma.

[Example 2]
In Example 2, the same configuration and settings as in Example 1 were used except that the scanning speed of the nozzle during modeling was set to 50 mm / sec.

[Example 3]
In the third embodiment, the configuration shown in FIG. 9 above is adopted, and an ozone-free type cylindrical UV lamp that mainly emits a wavelength of 254 nm is attached to a rotary table as a surface treatment device, and the molding material layer immediately after being extruded from the nozzle The configuration and settings were the same as in Comparative Example 1 except that the interface was irradiated with ultraviolet rays. The Gap to the lower layer to be irradiated was set to be 8 mm.

[Example 4]
Example 4 has the same configuration and settings as Example 3 except that the UV lamp is changed to an ozone generation type lamp that mainly emits a wavelength of 185 nm.

Investigate the interfacial strength of the three-dimensional model formed in Comparative Examples 1 and 2 and Examples 1 to 4. Autograph AGS-5kNX (manufactured by Shimadzu Corporation) was used to measure the adhesive force at the interface of the modeled object.
FIG. 11 is a diagram illustrating the measurement of the interfacial strength.
As shown in FIG. 11, one end of the linear modeling product Ms composed of two modeling material layers is physically peeled off in advance to separate the lower modeling material layer m1 and the upper modeling material layer m2. Then, one end of the upper modeling material layer m2 is chucked to the upper chuck 110a, and one end of the lower modeling material layer m1 is chucked to the lower chuck. Next, as shown by the arrow in the figure, the upper chuck in the figure is moved upward at 200 mm / min to acquire the strength profile of the interface K between the upper modeling material layer m2 and the lower modeling material layer m1. In the acquired strength profile, the average value was obtained from the maximum value and the minimum value in the 10 mm section corresponding to the central portion, and the average value was taken as the interfacial strength. The results are shown in Table 1.

As can be seen from Table 1, Examples 1 to 4 in which the interface K of the lower modeling material layer m1 is irradiated with atmospheric pressure plasma or UV to modify the surface of the interface K are the lower modeling material layers. The interface strength was significantly stronger than that of Comparative Examples 1 and 2 in which the surface modification of the interface K of m1 was not performed. Further, although the interface strength can be increased by increasing the nozzle scanning speed, compared with the case where the interface K of the lower molding material layer m1 is surface-modified by performing atmospheric pressure plasma irradiation or UV irradiation. Its strength increase is slight. From this, it was found that the interface strength can be effectively increased by irradiating the interface K of the lower modeling material layer m1 with atmospheric pressure plasma or UV to modify the surface of the interface K. ..

1: Three-dimensional modeling device 7: Mounting table 10: Housing 20: Modeling head 21: Nozzle 22: Heating block 22a: Heat source 22b: Thermoelectric pair 23: Guide block 24: Cooling block 24a: Flow path 25: Extruder 25a: Feed Roller 26: Transfer path 28: Support member 30: Filament 30a: Molten filament 31: Reel 41: Z-axis drive motor 42: Z-axis feed screw 43: Z-axis coordinate detection mechanism 44: Mounting base guide shaft 51: X-axis drive motor 52: X-axis feed screw 53: X-axis coordinate detection mechanism 54: X-axis guide shaft 61: Y-axis drive motor 61a: Feed screw holder 62: Y-axis feed screw 63: Y-axis coordinate detection mechanism 64: Y-axis guide Shaft 65: Moving member 66: Guided member 70: Nozzle cleaning unit 71: Brush 72: Brush motor 73: Recovery box 80: Atmospheric pressure plasma radiator 81: Electrode 82: Rotating table 83: Table rotating motor 83a: Motor gear 85: Surface treatment device Power supply 90: Drive unit 100: Modeling module 110a: Upper chuck 181: UV lamp 182: Bracket 200: Control device 201: Data generation unit 202: Heating temperature control unit 203: Extrusion amount control unit 204: Drive control unit 205 : Surface treatment control unit K: Interface M: Three-dimensional model Mb: Model model Ms: Straight model S: Plasma irradiation region

Japanese Unexamined Patent Publication No. 2015-189024

Claims (9)

With a mounting table
A modeling means for forming a modeling material layer on a mounting table by moving relative to the above-mentioned stand while extruding the modeling material.
A surface modifying means for modifying the surface of the molding material layer and
The surface modifying means, Bei example and means for relatively moving with respect to the mounting table before with the shaping means,
The surface modifying means is held by a holding means for holding the modeling means so as to be located upstream of the modeling means in the relative moving direction of the modeling means.
A three-dimensional modeling device characterized in that the holding means is rotatably provided in a horizontal plane. The three-dimensional modeling apparatus according to claim 1, wherein the surface modification treatment is performed by the surface modification means during the unit layer modeling operation in which one layer of the modeling material layer is formed by the modeling means. The surface modification means is arranged in the vicinity of the modeling means,
The surface modifying means according to claim 1 or 2, wherein the surface of the modeling material extruded from the modeling means is modified within a predetermined time after the modeling material is extruded from the modeling means. The described three-dimensional modeling device. The three-dimensional modeling apparatus according to claim 3, wherein the predetermined time is within 50 seconds . Before Symbol surface modification means, the three-dimensional modeling apparatus according to claim 1 to 4 any one, characterized in that a plurality in the rotational direction of the holding means. The three-dimensional modeling apparatus according to any one of claims 1 to 5, wherein the surface modifying means modifies the surface of the modeling material layer by cutting the molecular chain of the modeling material. The three-dimensional modeling apparatus according to claim 6 , wherein the surface modifying means is a plasma emitting means that radiates plasma to the surface of the modeling material layer. The three-dimensional modeling apparatus according to claim 6, wherein the surface modifying means is an ultraviolet irradiation means that irradiates the surface of the modeling material layer with ultraviolet rays. The modeling means includes an introduction section for introducing the modeling material, an extrusion section for pushing out the modeling material, a transfer path for transferring the modeling material introduced from the introduction section to the extrusion section, and the transfer path. A heating unit that heats the modeling material inside, a cooling unit that is provided between the introduction unit and the heating unit and cools the modeling material in the transfer path, and the modeling that is heated by the heating unit. Claim 1 is characterized by comprising a temperature detecting unit for detecting the temperature of the material and a control means for controlling the modeling means so as to keep the temperature of the modeling material constant based on the temperature detecting unit. to 3D modeling equipment according to 8 have shifted or claim.

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