The present invention relates to a fabricating apparatus and a method for manufacturing a fabrication object.
Three-dimensional (3D) printers are becoming widespread as a device capable of producing many types of products in small quantities without using dies or the like. 3D printers using a thermal melting lamination method (hereinafter, abbreviated as FFF (fused filament fabrication)) have been lowered in price in recent years and are also penetrating for consumers. There is known a technique of roughening and laminating the surfaces of layers to prevent the strength of a three-dimensional fabrication object from decreasing in a lamination direction of the three-dimensional fabrication object.
Patent Literature 1 discloses a three-dimensional fabricating apparatus that includes a discharge unit to discharge a fabrication material toward a fabrication stage to form a fabrication material layer, a smoothing unit to smooth the surface of the fabrication material layer formed by the discharging unit, a hardening unit to perform hardening treatment to promote hardening of at least the surface of the fabrication material layer smoothed by the smoothing unit, and a roughening unit to roughen the hardened surface of the fabrication material layer hardened by the hardening treatment of the hardening unit. According to Patent Literature 1, since the next fabrication material layer (N+1th layer) is formed on the roughened surface of the fabrication material layer (Nth layer), the adhesion between the fabrication material layers would increase due to an increase in contact area between the fabrication material layer (Nth layer) and the next fabrication material layer (N+1th layer) and an anchoring effect that the fabrication material of the next fabrication material layer (N+1th layer) incorporates into the roughened surface of the fabrication material layer (Nth layer).
PTL 1: Japanese Unexamined Patent Application Publication No. 2015-074164
However, when the surface of the fabrication material layer is roughened to enhance the adhesion between the fabrication material layers, there is a problem that the fabrication accuracy of the fabrication object decreases.
In an aspect of the present invention, there is provided a fabricating apparatus that includes a discharger and a heating unit. The discharger discharges a melted fabrication material to form a fabrication material layer. The heating unit heats the fabrication material layer formed by the discharger. The discharger discharges the melted fabrication material to the fabrication material layer heated by the heating unit, to laminate another fabrication material layer on the fabrication material layer heated by the heating unit.
The present invention has an effect that the deterioration of fabrication accuracy of a fabrication object can be prevented while enhancing the adhesiveness between fabrication material layers.
Hereinafter, embodiments of the present invention are described with reference to the drawings.
Overall Structure
Below, a three-dimensional fabricating apparatus to fabricate a three-dimensional object by fused filament fabrication (FFF) is described as an embodiment of the present invention. The three-dimensional fabricating apparatus according to the present embodiment is not limited to a three-dimensional fabricating apparatus using fused filament fabrication (FFF), but may be any method for fabricating a three-dimensional fabrication object on a mount surface of a mount table by a fabrication unit
The interior of a housing 2 of the three-dimensional fabricating apparatus 1 is a processing space for fabricating a three-dimensional fabrication object MO. A fabrication table 3 as a mount table is disposed inside the housing 2, and the three-dimensional fabrication object MO is molded on the fabrication table 3.
For fabrication, a long filament F is used that is made of a resin composition using a thermoplastic resin as a matrix. The filament F is an elongated wire-shaped solid material and is set on a reel 4 outside the housing 2 of the three-dimensional fabricating apparatus 1 in a wound state. The reel 4 is pulled by the rotation of an extruder 11, which are driving units of the filament F, to rotate without greatly exerting a resistance force.
A discharge module 10 (fabrication head) as a fabrication material discharger is disposed above the fabrication table 3 inside the housing 2. The discharge module 10 is modularized by the extruder 11, a cooling block 12, a filament guide 14, a heating block 15, a discharge nozzle 18, image pickup modules 101, a torsion rotation assembly 102, and other components. The filament F is drawn in by the extruder 11 and supplied to the discharge module 10 of the three-dimensional fabricating apparatus 1.
The image pickup modules 101 pick up a 360° image of the filament F drawn into the discharge module 10, that is, an omnidirectional image of a certain part of the filament F. Here, a cross section of the discharge module 10 will be described with reference to
The torsion rotation assembly 102 includes rollers and regulates a direction of the filament F by rotating the filament F drawn into the discharge module 10 in a width direction. A diameter measuring unit 103 measures a width between edges of the filament F in two directions of X axis and Y axis as a diameter, from an image of the filament F picked up by the image pickup modules 101, and outputs error information in response to detection of an outsize diameter. The output destination of the error information may be a display, a speaker, or another device. The diameter measuring unit 103 may be a circuit or a function realized by the processing of a central processing unit (CPU).
The heating block 15 includes heat sources 16, such as heaters, and a thermocouple 17 to control the temperature of the heat sources 16. The heating block 15 heats and melts the filament F supplied to the discharge module 10 via a transfer path, and supplies the melted filament F to a discharge nozzle 18.
The cooling block 12 is disposed above the heating block 15. The cooling block 12 includes cooling sources 13 and cools the filament F. Accordingly, the cooling block 12 prevents a reverse flow of a melted filament FM to an upper part in the discharge module 10, an increase in resistance in pushing out the filament, or clogging in the transfer path due to solidification of the filament. Between the heating block 15 and the cooling block 12, a filament guide 14 is disposed.
As illustrated in
In the present embodiment, two discharge nozzles are disposed in the discharge module 10. A first discharge nozzle fuses and discharges a filament of a model material constituting a three-dimensional fabrication object, and a second discharge nozzle fuses and discharges a filament of a support material to support the model material. In
The support material discharged from the second discharge nozzle is typically a material different from the model material constituting the three-dimensional fabrication object. A support portion formed of the support material is finally removed from a model portion formed of the model material. The filament of the support material and he filament of the model material are separately melted in the heating block 15, are discharged so as to be extruded from the respective discharge nozzles 18, and are sequentially laminated in layers.
The three-dimensional fabricating apparatus 1 includes heating modules 20 to heat a lower layer below a layer being formed by the discharge module 10. Each heating module 20 includes a laser source 21 that emits a laser. The laser source 21 emits the laser to a position in the lower layer immediately downstream from a position to which the filament FM is discharged. The laser source is not particularly limited but may be, for example, a semiconductor laser. The emission wavelength of the laser may be, for example, 445 nm.
The discharge module 10 and the heating module 20 are slidably held by a connecting member with respect to an X-axis driving shaft 31 (an X-axis direction) extending in a lateral direction (a horizontal direction in
The X-axis driving motor 32 is held slidably along a Y-axis driving shaft (Y-axis direction) extending in a device front-back direction (a depth direction in
Meanwhile, the fabrication table 3 is passed through by a Z-axis driving shaft 34 and a guide shaft 35, and is held to be movable along the Z-axis driving shaft 34 extending in a vertical direction (up-down direction in
When the melting and discharging of the filament continue over time, a peripheral portion of the discharge nozzle 18 may be contaminated with melted resin. On the other hand, a cleaning brush 37 of the three-dimensional fabricating apparatus 1 regularly performs a cleaning operation on the peripheral portion of the discharge nozzle 18 to prevent the resin from sticking to a tip of the discharge nozzle 18. From the viewpoint of prevention of sticking, it is preferable that the cleaning operation be performed before the temperature of the resin is fully lowered. In such a case, the cleaning brush 37 is preferably made of a heat resistant member. Abrasive powder generated during the cleaning operation may be accumulated in a dust box 38 of the three-dimensional fabricating apparatus 1 and regularly discarded from the dust box 38, or may be discharged to the outside via a suction path of the three-dimensional fabricating apparatus 1.
The three-dimensional fabricating apparatus 1 is disposed with an X-axis coordinate detection mechanism to detect the position of the discharge module 10 in the X-axis direction. The detection result of the X-axis coordinate detection mechanism is sent to the controller 100. The controller 100 controls the driving of the X-axis driving motor 32 according to the detection result, and moves the discharge module 10 to a target position in the X-axis direction.
The three-dimensional fabricating apparatus 1 is disposed with a Y-axis coordinate detection mechanism to detect the position of the discharge module 10 in the Y-axis direction. The detection result of the Y-axis coordinate detection mechanism is sent to the controller 100. The controller 100 controls the driving of the Y-axis driving motor 33 according to the detection result and moves the discharge module 10 to a target position in the Y-axis direction.
The three-dimensional fabricating apparatus 1 is disposed with a Z-axis coordinate detection mechanism to detect the position of the fabrication table 3 in the Z-axis direction. The detection result of the Z-axis coordinate detection mechanism is sent to the controller 100. The controller 100 controls the driving of the Z-axis driving motor 36 according to the detection result and moves the fabrication table 3 to a target position in the Z-axis direction.
In such a manner, the controller 100 controls the movement of the discharge module 10 and the fabrication table 3 to move the relative three-dimensional positions of the discharge module 10 and the fabrication table 3 to the target three-dimensional positions.
The controller 100 sends control signals to drivers of the extruder 11, the cooling block 12, the discharge nozzle 18, the laser source 21, the cleaning brush 37, the rotary stage RS, the image pickup module 101, the torsion rotation assembly 102, the diameter measuring unit 103, and the temperature sensor 104 to control the driving of each of the extruder 11, the cooling block 12, the discharge nozzle 18, the laser source 21, the cleaning brush 37, the rotary stage RS, the image pickup module 101, the torsion rotation assembly 102, the diameter measuring unit 103, and the temperature sensor 104. The rotary stage RS, a side cooler 39, the image pickup module 101, the torsion rotation assembly 102, the diameter measuring unit 103, and the temperature sensor 104 are described later.
<<Heating Method>>
During the fabrication of an upper layer by the discharge module 10, the laser source 21 emits the laser to a position just ahead of a position to which the filament FM is discharged, in a direction of movement of the discharge module 10. The term “reheating” refers to heating again after the melted filament FM has cooled and solidified. The reheating temperature is not particularly limited, but it is preferable that it is not lower than the temperature at which the lower filament FM melts. In the following description, the reheating at or above the temperature at which the underlying filament FM melts may be referred to as remelting.
The temperature of the lower layer before heating is sensed by the temperature sensor 104. The position of the temperature sensor 104 is arranged at any position at which the temperature sensor 104 can sense the surface of the lower layer before heating. For the present embodiment, in
Reheating the surface of the lower layer reduces the temperature difference between the lower layer and the filament FM discharged onto the surface of the lower layer and mixes the lower layer and the discharged filaments, thus enhancing the adhesiveness in the lamination direction.
In the present embodiment, the upper layer Ln layer is formed in a state in which the lower layer Ln−1 is partially remelted. Accordingly, entanglement of polymers between the upper layer Ln and the lower layer Ln−1 is promoted, thus enhancing the strength of the fabrication object. In addition, appropriate setting of the conditions for remelting can achieve both of the accuracy of shape and the strength of the model part M in the lamination direction. Hereinafter, a setting example of a remelted region and an effect of setting of the remelted region in the present embodiment is described below.
A model material and a support material may be the same material or may be different. For example, even when the model part M and the support part S are made of the same material, controlling the strength of the interface allows separation of the model part M and the support part S after fabrication.
In the fabrication method of
The fabrication method of
In the fabrication method of
The fabrication method in
In the fabrication method of
The fabrication method of
The fabrication method of
<<Process and Operation>>
Subsequently, the processing and operation of the three-dimensional fabricating apparatus 1 in one embodiment is described below.
The controller 100 of the three-dimensional fabricating apparatus 1 accepts input of data of a three-dimensional model. The data of the three-dimensional model is constructed by image data of each layer obtained when the three-dimensional model is sliced at predetermined intervals.
The controller 100 of the three-dimensional fabricating apparatus 1 drives the X-axis driving motor 32 or the Y-axis driving motor 33 to move the discharge module 10 in the X-axis direction or the Y-axis direction. While the discharge module 10 is moving, the controller 100 causes the discharge nozzle 18 to discharge melted or semi-melted filament FM to the fabrication table 3 according to image data of a lowest layer among the input data of the three-dimensional model. Thus, the three-dimensional fabricating apparatus 1 forms, on the fabrication table 3, a layer having a shape based on the image data (step S11).
While the discharge module 10 is moving, the controller 100 causes the laser source 21 to emit a laser based on image data of the lowest layer of layers that have not been fabricated in the input data of the three-dimensional model. Accordingly, a position in the lower layer to which the laser is emitted is remelted (step S12). Note that the controller 100 may causes the laser source 21 to emit the laser inside a range indicated by the image data as in the fabrication methods of
While the discharge module 10 is moving, the controller 100 causes the discharge nozzle 18 to discharge the filament FM to a lower layer on the fabrication table 3 according to the image data of the lowest layer of the layers that have not been fabricated, among the data of the input three-dimensional model. Accordingly, a layer having a shape corresponding to the image data is formed on the lower layer (step S13). At this time, since the lower layer is remelted, the adhesion of the interface between the layer to be fabricated and the lower layer is enhanced.
Note that the process of remelting the lower layer in step S12 and the process of forming the layer in step S13 may be overlapped. In such a case, the three-dimensional fabricating apparatus 1 starts discharge of the filament FM after the start of the process of emitting the laser to the lower layer and before the completion of emission of the laser to the entire emission range.
The controller 100 of the three-dimensional fabricating apparatus 1 determines whether the layer formed in step S13 is the outermost layer (step S14). The outermost layer is a layer formed based on image data having the largest coordinate in the lamination direction (Z axis) among the data of the three-dimensional model. If NO in step S14, the controller 100 of the three-dimensional fabricating apparatus 1 repeats the remelting process (step S12) and the layer formation process (step S13) until the outermost layer is formed.
When the formation of the outermost layer is completed (YES in step S14), the three-dimensional fabricating apparatus 1 terminates the fabrication process.
<<<Variation A of Embodiment>>>
Subsequently, a description is given of a variation A of the above-described embodiment with respect to differences from the above-described embodiment.
In the variation A, the heating module 20 has a hot air source 21′. As the hot air source 21′, for example, a heater or a fan may be used. In the variation A of the above-described embodiment, the hot air source 21′ blows hot air to a lower layer to heat and remelt the lower layer. Also in the variation A of the above-described embodiment, the filament FM is discharged to the remelted lower layer to form an upper layer. Accordingly, the materials of the lower layer and the upper layer are mixed, thus enhancing the adhesiveness between the upper layer and the lower layer.
<<<Variation B of Embodiment>>>
Next, a variation B of the above-described embodiment is described with respect to differences from the above-described embodiment.
In the variation B, the heating module 20 of the three-dimensional fabricating apparatus 1 according to the above-described embodiment is replaced with a heating module 20′. The heating module 20′ includes a heating plate 28 to heat and pressurize a lower layer of the three-dimensional fabrication object MO, a heating block 25 to heat the heating plate 28, a cooling block 22 to prevent heat conduction from the heating block 25. The heating block 25 includes a heat source 26, such as a heater, and a thermocouple 27 to control the temperature of the heating plate 28. The cooling block 22 includes a cooling source 23. A guide 24 is disposed between the heating block 25 and the cooling block 22.
The heating module 20′ is slidably held by a connecting member with respect to the X-axis driving shaft 31 (the X-axis direction) extending in the lateral direction (the horizontal direction in
In the heating module 20′, a lower end of the heating plate 28 is arranged to be lower by one layer than a lower end of the discharge nozzle 18. While the discharge module 10 and the heating module 20′ are scanned in a direction indicated by hollow arrows of
According to the variation B, physically mixing the materials between the layers can enhance the adhesion at the interface between the layers. Further, according to the variation B, a lower layer is selectively heated without collapsing the outer shape of the fabrication object and the next discharge is performed while the lower layer is remelted, thus enhancing the adhesion of the interface.
<<<Variation C of Embodiment>>>
Next, a variation C of the above-described embodiment is described with respect to differences from the variation B of the above-described embodiment.
In the variation C, the heating plate 28 in the heating module 20′ is replaced with a tap nozzle 28′. The tap nozzle 28′ is heated by the heating block 25. The tap nozzle 28′ performs a tapping operation of repeatedly tapping the three-dimensional fabrication object MO from vertically above the three-dimensional fabrication object MO by power of a motor or the like, to heat and pressurize a lower layer in the three-dimensional fabrication object MO. Accordingly, the temperature difference between the layer under fabrication and the layer below the layer under fabrication is reduced and the materials are mixed between the layers, thus enhancing the interlayer strength of the fabrication object. After the tapping operation, the filament FM is discharged from the discharge nozzle 18 to fill the surface of the lower layer dented by the tapping operation. Filling the dented portion of the lower layer with the filament FM smoothly finishes the shape of the outermost surface.
<<<Variation D of Embodiment>>>
Next, a variation D of the above-described embodiment is described with respect to differences from the above-described embodiment.
In the variation D, the heating module 20 includes a side cooler 39 to cool a side surface, which is a surface parallel to the Z axis, of the three-dimensional fabrication object MO. The side cooler 39 is not limited to a particular type of cooling source and may be any cooling source capable of cooling the side surface of the three-dimensional fabrication object MO. For example, a fan is used as the side cooler 39.
If the outer peripheral portion of the three-dimensional fabrication object MO is reheated without being processed for maintaining the outer shape, the outer shape would collapse and the fabrication accuracy would deteriorate. Hence, in the variation D, the heating module 20 reheats the outer peripheral portion of the three-dimensional fabrication object MO while applying cooling air to the side surface of the three-dimensional fabrication object MO, thus allowing lamination of materials while maintaining the shape of a fabricated portion.
<<<Variation E of Embodiment>>>
Next, a variation E of the above-described embodiment is described with respect to differences from the above-described embodiment.
When fabrication is performed while heating a lower layer or the fabrication space, the viscosity of a heated portion in the three-dimensional fabrication object MO decreases, which may collapse the outer shape and reduce the fabrication accuracy. By contrast, when fabrication is performed without heating a lower layer or the fabrication space, the viscosity of the three-dimensional fabrication object MO increases, which may hamper the maintenance of the strength in the lamination direction. Hence, in the variation E, a filament having an uneven material composition is used for fabrication.
The high viscosity resin Rh disposed on both sides of the filament F is not limited to any particular type of resin. For example, a high viscosity resin, such as alumina, carbon black, carbon fiber, or glass fiber, which is made highly viscous by blending a filler, may be used. If the filler inhibits a desired function, a resin having a controlled molecular weight may be used as the high viscosity resin Rh.
The low viscosity resin R1 disposed in the center portion of the filament F is not also limited to any particular type of resin. For example, a resin having a low molecular weight grade is used.
However, when the filament of
To enhance the adhesion in the lamination direction of the outer peripheral portion, the outer peripheral portion is preferably heated in a state in which the plate directly contacting the fabrication object from a lateral side of the fabrication object. Such heating can restrict the movement of the resin in the horizontal direction due to the viscosity decrease.
In the example of
It is preferable that the plate of the assist mechanism 41 is heated to a temperature higher than normal temperature. Although depending on a resin used, in the case of a crystalline resin, the resin is quenched when the resin is hit by the plate at normal temperature. Accordingly, amorphization progresses and a desired strength may not be obtained.
Generally, viscosity is expressed as a function of temperature and shear rate. Engineering plastic or super engineering plastic etc. used in the fused filament fabrication (FFF) method exhibits nonlinear behavior with respect to a variable, such as temperature or shear rate. Accordingly, even if it is not higher than the melting point Tm of the resin, the shear resistance, that is, the viscosity of the resin necessary in the FFF method may be obtained. On the other hand, if the viscosity at a desired shear rate (S. Rate) is too low in an area higher than the Tm, there may occur problems, such as a liquid drip from the nozzle, an insufficient retraction in the filament retraction (retracting motion), an associated short shot at the initial discharge, the collapse of the fabrication object.
When the resin is at a predetermined temperature equal to or higher than Tm, generally, the resin has a highest viscosity at the temperature at the time of S. Rate=0, that is, non-discharge operation. If the liquid drips even in such a state, compositing of the resin by a filler can be an effective means for preventing the dripping. By adding a filler to the resin and controlling the compounding ratio or the particle size, fiber length distribution etc. of the compound to be blended, thixotropy at melting is imparted. Such a configuration prevents the liquid from dripping at non-discharge operation and causes the liquid to be in a state of low viscosity at discharge operation.
The method of adding a filler to the filament is also preferable to prevent the fabrication object from easily collapsing with an increase in the temperature of the lower layer. If the fabrication accuracy cannot be maintained even with the addition of the filler, it is preferable to regulate a lateral side of the fabrication object.
<<<Variation F of Embodiment>>>
Next, a variation F of the above-described embodiment is described with respect to differences from the above-described variation E.
In the case of using a filament in which the material composition is unevenly distributed, it is preferable to regulate the direction in which the filament is introduced into the discharge module 10 so that the high viscosity resin Rh is arranged on the outer peripheral portion of the fabrication object.
The controller 100 receives the image data of the filament transmitted by the image pickup module 101 (step S21). The controller 100 analyzes the image data of the received filament and calculates the rotation amount (step S22). There is no particular limitation on the method of calculating the rotation amount. For example, a method is used of determining the rotation amount such that the boundary between the high viscosity resin Rh and the low viscosity resin R1 in the filament F is at a predetermined position. For example, in the case of discharging the filament while moving the discharge module 10 in the X-axis direction, the high viscosity resin Rh in the filament is unevenly distributed in the positive and negative directions of the Y-axis. Thus, the high viscosity resin is arranged at an outermost portion of the fabrication object. Therefore, the controller 100 determines the rotation amount of the filament so that the high viscosity resin Rh is unevenly distributed in the positive and negative directions of the Y axis.
Based on the determined rotation amount, the controller 100 transmits a signal for rotating the filament to the torsion rotation assembly 102. The torsion rotation assembly 102 rotates the filament based on the signal (step S23). As a result, the filament is regulated in a desired direction.
When a high viscosity resin is disposed on the outside of the filament, the flow velocity on the wall side of the filament becomes extremely slow in the transfer path and the high viscosity resin stays, thus hampering discharge of the filament in a desired arrangement. Therefore, in a region downstream from the heating block 25, that is, in a region to which a temperature equal to or higher than the melting point is applied, the inner wall of the transfer path is preferably processed with fluorine or the like having high heat resistance. By forming the release layer in the transfer path, the frictional resistance between the melted resin and the inner wall of the transfer path decreases, and the stay of the high viscosity resin is unlikely to occur.
In consideration of a time lag of the conveyance in a section from the torsion rotation assembly 102 to the discharge nozzle 18, the controller 100 preferably performs feedforward control to prevent control delay. For example, the controller 100 controls driving of the torsion rotation assembly 102 so that the direction of the filament is switched at the timing when the movement direction of the discharge module 10 is turned. Also, when advancing the discharge module 10 along a curved line, the controller 100 controls driving of the torsion rotation assembly 102 stepwise in consideration of time lag.
If the filament is extremely twisted, the filament might be entangled in the route from the reel 4 to the introduction part of the discharge module 10. It would be very troublesome for a user to unravel the entanglement. Therefore, a guide tube is preferably introduced from the reel 4 to the introduction portion. However, if the filament is extremely twisted, the frictional resistance between the guide tube and the filament would increase and the filament may not be normally introduced. In addition, the filament may be scraped at an orifice portion having a narrow inner diameter, such as a joint of the guide tube. In a reinforced filament or the like in which a filler is blended, the flexibility peculiar to resin is often lost. When such a filament is subjected to a torsional load, the filament may be broken, thus hampering normal fabrication.
Therefore, the controller 100 preferably regulates the cumulative twist amount of the filament, for example, in a range from a reference angle to ±180°.
Further, instead of the mechanism for rotating the filament, a mechanism capable of rotating the entire discharge module 10 may be used so that the resin is arranged in a desired state in the discharged object, for example, as illustrated in
<<<Variation G of Embodiment>>>
Subsequently, a description is given of a variation G of the above-described embodiment with respect to differences from the above-described embodiment.
In the variation G, the three-dimensional fabricating apparatus 1 includes a heating module 20″. The heating module 20″ includes a horn 30 to heat and pressurize the three-dimensional fabrication object MO. The three-dimensional fabricating apparatus 1 includes an ultrasonic vibration device. The horn 30 moves downward from above the lamination surface of the three-dimensional fabrication object MO by the Z-axis driving motor, and applies pressure to the lamination surface. Thus, the vibration of an ultrasonic wave generated by the ultrasonic vibration device is transmitted to the three-dimensional fabrication object MO. When the ultrasonic vibration is transmitted to the three-dimensional fabrication object MO, the upper layer Ln and the lower layer Ln−1 of the three-dimensional fabrication object MO are welded and joined. In the three-dimensional fabricating apparatus 1, the number of the horn 30 is not limited to one, and is appropriately selected. In the case in which a plurality of horns 30 is disposed, the shape of the horn need not be unified, and horns of different shapes may be mounted.
In the following examples and comparative examples, the maximum tensile strength of a fabrication object formed by the three-dimensional fabricating apparatus 1 is measured. Note that Autograph AGS-5 kNX (manufactured by Shimadzu Corporation) was used for measuring the maximum tensile strength of the fabrication object.
In comparative examples, a tensile test piece is formed without executing the remelting operation (step S12) using the three-dimensional fabricating apparatus 1. In Comparative Example 1, a thermally-soluble resin is used as a filament being a fabrication material. For the introduction part of the discharge module 10, a pair of rollers made of stainless steel (SUS) 304 of φ12 was used. The dimensional shape of the transfer path of the discharge module 10 was a bar shape having a circular cross section. The discharge nozzle 18 at the tip of the discharge module 10 was made of brass and the opening diameter of the tip was 0.5 mm. The part to be the transfer path was made to be a cavity of φ2.5 mm. The cooling block 22 was made of SUS 304. The cooling block 22 was passed through by a water cooling pipe and connected to a chiller. The set temperature of the chiller was 10° C. Similarly with the cooling block 22, the heating block 25 was also made of SUS 304. A cartridge heater serving as the heat source 26 was passed through the heating block 25, and the thermocouple 27 was disposed on the side symmetrical to the filament to control the temperature. The set temperature of the cartridge heater was set to be equal to or higher than the melting temperature of the resin. A tensile test piece as illustrated in
In Comparative Example 2, a thermally-soluble resin is used as a filament being a fabrication material. For the introduction part of the discharge module 10, a pair of rollers made of stainless steel (SUS) 304 of p12 was used. The dimensional shape of the transfer path of the discharge module 10 was a bar shape having a circular cross section. The discharge nozzle 18 at the tip of the discharge module 10 was made of brass and the opening diameter of the tip was 0.5 mm. The part to be the transfer path was made to be a cavity of φ2.5 mm. The cooling block 22 was made of SUS 304. The cooling block 22 was passed through by a water cooling pipe and connected to a chiller. The set temperature of the chiller was 10° C. Similarly with the cooling block 22, the heating block 25 was also made of SUS 304. A cartridge heater serving as the heat source 26 was passed through the heating block 25, and the thermocouple 27 was disposed on the side symmetrical to the filament to control the temperature. The set temperature of the cartridge heater was set to be equal to or higher than the melting temperature of the resin. A tensile test piece as illustrated in
In Example 1, a tensile test piece was fabricated using the three-dimensional fabricating apparatus 1 including the heating module 20 at the same setting (image data to be used, temperature, and scanning speed) as in Comparative Example 1. At this time, a process was repeated of, after a lower layer was cooled, reheating a lower layer to a temperature higher than the melting point of the filament to remelt the surface of the lower layer (step S12) and forming an upper layer.
In Example 2, a tensile test piece was fabricated using the three-dimensional fabricating apparatus 1 including the heating module 20 at the same setting (image data to be used, temperature, and scanning speed) as in Comparative Example 2. At this time, a process was repeated of, after a lower layer was cooled, reheating a lower layer to a temperature higher than the melting point of the filament to remelt the surface of the lower layer (step S12) and forming an upper layer.
In any of Examples 1 and 2, the maximum tensile strength greater than the maximum tensile strength of each of Comparative Examples 1 and 2 was obtained. From the above, it is understood that the strength in the lamination direction of the three-dimensional fabrication object can be increased by the three-dimensional fabricating apparatus 1 having the configuration of the above-described embodiment.
<<Main Effects of the Embodiment>>
The discharge module 10 (an example of a discharger) of the three-dimensional fabricating apparatus 1 (an example of a fabricating apparatus) of the above-described embodiment discharges a melted filament (an example of a fabrication material) to form a fabrication material layer. The heating module 20 (an example of a heating device) of the three-dimensional fabricating apparatus 1 heats the formed building material layer. The discharge module 10 discharges the melted filament to the heated fabrication material layer, to laminate fabrication material layers for fabrication. According to the above-described embodiment, the filament is discharged to a melted fabrication material layer (lower layer) to laminate a fabrication material layer (upper layer) on the melted fabrication material layer. Accordingly, materials between layers mix together, thus allowing enhancement of the strength in the lamination direction of the fabrication object. Further, the process of laminating the upper layer allows fabrication to be performed without affecting the fabrication accuracy of the outer shape.
The heating module 20 of the three-dimensional fabricating apparatus 1 selectively heats a predetermined region of the fabrication material layer. Thus, fabrication can be performed while maintaining the shape of the fabrication object.
The rotary stage RS (an example of a conveyor) of the three-dimensional fabricating apparatus 1 conveys the heating module 20 so that a predetermined position can be heated from different directions. Thus, the heating module 20 can heat the fabrication material layer following the movement of the discharge module 10.
The three-dimensional fabricating apparatus 1 includes the temperature sensor 104 (an example of a measuring unit) to measure the temperature of a fabrication material layer heated by the heating module 20. The heating module 20 heats the fabrication material layer according to the temperature measured by the temperature sensor 104. Thus, the three-dimensional fabricating apparatus 1 can appropriately reheat the fabrication material layer according to desired characteristics, such as interlayer adhesion strength or fabrication accuracy.
The heating module 20 may be a laser source 21 (an example of an emitter) that emits laser light. Thus, the heating module 20 can selectively heat the fabrication object without contacting the fabrication object.
The heating module 20 may be a hot air source (an example of an air blower) for blowing heated air. Thus, the heating module 20 can selectively heat the fabrication object without contacting the fabrication object.
The heating module 20′ may be the heating plate 28 or the tap nozzle 28′ (an example of a member of the heating module 20′) to contact and heat the fabrication material layer. Thus, the heating module 20′ can selectively heat the fabrication object.
The three-dimensional fabricating apparatus 1 may include a plurality of heating modules 20. Thus, even if the scanning direction of the discharge module 10 is changed, at least one of the heating modules 20 can heat the fabrication object, thus shortening the fabrication time.
The side cooler 39 (an example of a cooler) of the three-dimensional fabricating apparatus 1 cools the outer peripheral portion of the fabrication object formed of the fabrication material. Thus, the three-dimensional fabricating apparatus 1 can fabricate the fabrication object while maintaining the shape of the fabrication object.
A plurality of materials having different viscosities is arranged in the filament. Thus, under the control of the controller 100, the discharge module 10 can discharge the filament so that a material having a lower viscosity is disposed at the outer peripheral portion.
The assist mechanism 41 (an example of a supporter) of the three-dimensional fabricating apparatus 1 supports the formed fabrication material layer. Thus, the three-dimensional fabricating apparatus 1 can fabricate the fabrication object while maintaining the shape of the formed fabrication material layer.
The above-described embodiments are illustrative and do not limit the present invention. Thus, numerous additional modifications and variations are possible in light of the above teachings. For example, elements and/or features of different illustrative embodiments may be combined with each other and/or substituted for each other within the scope of the present invention.
This patent application is based on and claims priority pursuant to 35 U.S.C. § 119(a) to Japanese Patent Application No. 2017-216116, filed on Nov. 9, 2017, and Japanese Patent Application No. 2018-097691, filed on May 22, 2018, in the Japan Patent Office, the entire disclosure of each of which is hereby incorporated by reference herein.
Number | Date | Country | Kind |
---|---|---|---|
2017-216116 | Nov 2017 | JP | national |
2018-097691 | May 2018 | JP | national |
Filing Document | Filing Date | Country | Kind |
---|---|---|---|
PCT/JP2018/041192 | 11/6/2018 | WO | 00 |