Molding device, screw, and operational method

Abstract

To provide a molding device, a screw, and an operational method capable of suitably performing production of a molding.SOLUTION: A molding device includes a barrel 82 to which a molding material is supplied, a heater 85 for heating the material supplied into the barrel 82, a rotary screw provided in the barrel 82 for transferring the material heated by the heater 85, a nozzle for discharging the material transferred by the screw, and a colorant injection mechanism 60 for injecting a colorant fluid into the barrel 82 and / or nozzle between the position where the material is supplied to the barrel 82 to the position where the material is discharged from the nozzle.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a molding machine, a screw, and an operating method. [Background technology]

[0002] In recent years, modeling devices have been used to create three-dimensional objects. One modeling device method is the fused deposition modeling method. In the fused deposition modeling method, pellets or filaments of thermoplastic resin, which are the modeling material, are supplied to a print head together with a colorant, so that the pellets or filaments ejected from the print head are colored. For example, Patent Document 1 discloses that when the filament is supplied to the print head, the filament is coated with a colorant before being supplied to the print head. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Special Publication No. 2014-516829 Summary of the Invention [Problem to be solved by the invention]

[0004] In the conventional method of supplying the modeling material and colorant to the print head from the same supply port, as in Patent Document 1, when switching colors or cleaning (flushing) the material path inside the print head, unnecessary modeling material had to be removed from the entire material path from the supply port to the discharge port inside the print head, which was time-consuming.

[0005] Furthermore, when pellets of the modeling material and pellets of the colorant are supplied to the print head from the same supply port, color unevenness is likely to occur.

[0006] In addition, in this case, since the optimal melting temperature for the modeling material is different from the optimal melting temperature for the colorant, it was not possible to optimize the temperature setting for heating the mixture of modeling material and colorant in the print head for both the modeling material and the colorant.

[0007] Furthermore, as in Patent Document 1, conventionally, the modeling material often remained in the barrel or nozzle for a long time, which could cause the modeling material to deteriorate and adversely affect its material properties, such as the viscosity and degree of solidification of the heated material, the strength and crystallinity of the material after hardening, and the appearance of the modeled object.

[0008] In view of the above, an object of the present invention is to provide a molding apparatus, a screw, and an operation method that can suitably manufacture a molded object. [Means for solving the problem]

[0009] A modeling apparatus according to a first aspect of the present invention comprises: a barrel into which material for molding is supplied; a heater for heating the material supplied into the barrel; a rotating screw provided in the barrel for transporting the material heated by the heater; a nozzle for discharging the material transported by the screw; and a colorant injection mechanism that injects a colorant fluid into the barrel and / or the nozzle between a position where the material is supplied to the barrel and a position where the material is discharged from the nozzle.

[0010] With the above configuration, the distance over which the material in the barrel is colored is shortened, allowing, for example, color switching and barrel cleaning to be performed in a short time. Furthermore, for example, since the colorant fluid is injected into the molten material before kneading, color unevenness is less likely to occur, and the melting temperature of the material can be controlled independently of the melting temperature of the colorant. This allows for optimal production of shaped objects.

[0011] The colorant injection mechanism may inject the colorant into the barrel and / or the nozzle near the nozzle.

[0012] According to the above configuration, the distance over which the material in the barrel is colored is shortened, so that, for example, color switching and barrel cleaning can be completed in a shorter time, thereby enabling the production of a shaped object to be performed in a more suitable manner.

[0013] The screws are arranged in the following order from the top end to the tip: a supply section to which the material before melting is supplied; a compression section that compresses the molten material; a metering section that transfers the compressed material at a constant flow rate; a kneading section for kneading the material and the colorant; Equipped with The colorant injection mechanism may inject the colorant into the barrel and / or the nozzle at a position where the metering section or the kneading section is housed.

[0014] With the above configuration, the distance over which the material in the barrel is colored is shortened, allowing for quick color changes and barrel cleaning, for example. Furthermore, because the same screw is used for both material extrusion and kneading, unlike when separate screws are used for extrusion and kneading, the rotation speed of the screw for extrusion and the rotation speed of the screw for kneading are the same, resulting in high reproducibility of the kneading results. This allows for optimal production of shaped objects.

[0015] The ink supply device may include a plurality of colorant injection mechanisms for injecting colorants of different colors into the barrel.

[0016] According to the above configuration, it is possible to reproduce an infinite number of colors by combining a plurality of colorants, which makes it possible to suitably manufacture shaped objects.

[0017] the colorant injection mechanism includes a colorant supply unit and a colorant kneading unit; the colorant supplying section preheats the colorant to at least partially melt it and supplies it to the colorant kneading section; The colorant kneading section may heat and knead the colorant supplied from the colorant supply section, and inject the kneaded colorant into the barrel.

[0018] According to the above configuration, for example, the colorant is melted in advance by the colorant supply unit, so that the colorant can be melted well even in a relatively small colorant kneading unit, thereby enabling the production of a shaped object to be carried out favorably.

[0019] The image forming apparatus may further include a colorant supply device that supplies colorant to the colorant injection mechanism when the remaining amount of colorant in the colorant injection mechanism falls below a predetermined remaining amount.

[0020] According to the above configuration, it is possible to prevent the colorant from running out in the colorant injection mechanism, thereby enabling the production of a shaped object to be carried out in an optimal manner.

[0021] A screw according to a second aspect for use in the molding apparatus according to the first aspect comprises: From the top to the tip, in order: a supply unit to which a pre-melted modeling material is supplied; a compression section that compresses the molten material; a metering section that transfers the compressed material at a constant flow rate; a kneading section for kneading the material and the colorant; Equipped with.

[0022] According to the above configuration, since the extrusion and kneading of the material are performed using the same screw, unlike when the extrusion and kneading of the material are performed using separate screws, the rotation speed of the screw for extrusion and the rotation speed of the screw for kneading are the same, and the kneading results are highly reproducible, which allows for the production of shaped objects in an optimal manner.

[0023] An operating method according to a third aspect of the present invention comprises: An operating method performed by a modeling apparatus according to a first aspect, When the time during which the material is not extruded from the barrel while the barrel is heated during modeling exceeds a predetermined time, a material supply stopping step of stopping the supply of the material to the barrel; a material extruding step forcing the material out of the barrel to substantially empty the barrel; Equipped with.

[0024] According to the above-described configuration, the material inside the barrel does not change in quality, and problems associated with the change in quality of the material can be avoided, thereby enabling the production of a shaped object to be carried out in an optimal manner.

[0025] An operating method according to a fourth aspect of the present invention comprises: An operating method performed by a modeling apparatus according to a first aspect, When cleaning the barrel, a material supply stopping step of stopping the supply of the material to the barrel; a barrel heating step of heating the material in the barrel to a predetermined temperature exceeding the melting temperature of the material; a material extruding step forcing the material out of the barrel to substantially empty the barrel; Equipped with.

[0026] According to the above configuration, in the modeling performed after cleaning, the altered material remains in the barrel, so that the adverse effects of the altered material on the modeling operation and the modeled object are not exerted. This allows for the optimal production of the modeled object. [Effects of the Invention]

[0027] According to the present invention, it is possible to provide a molding apparatus, a screw, and an operation method that can suitably manufacture a molded object. [Brief explanation of the drawings]

[0028] [Figure 1] FIG. 1 is a perspective view of a molding apparatus according to an embodiment of the present invention. [Figure 2] FIG. 2 is a perspective view of a print head of the modeling apparatus according to the present embodiment. [Figure 3] FIG. 2 is a side view showing the kneading and discharging unit of the modeling apparatus according to the present embodiment, with the motor removed. [Figure 4] FIG. 4 is a cross-sectional view taken along line AA in FIG. [Figure 5] 3A and 3B are diagrams illustrating a screw of the molding apparatus according to the present embodiment. [Figure 6] 1A and 1B are a side view and a top view of a colorant injection mechanism of a modeling apparatus according to the present embodiment. [Figure 7] FIG. 7 is a cross-sectional view taken along line BB in FIG. 6. [Figure 8] 1A and 1B are schematic diagrams of a colorant supply device according to a modified example, in which (a) the recess opens to the inlet of the metering device, and (b) the recess opens to the outlet of the metering device. The circles in the figure schematically represent colorants. DETAILED DESCRIPTION OF THE INVENTION

[0029] A modeling apparatus 100 according to an embodiment of the present invention will be described with reference to the drawings. The modeling apparatus 100 is an apparatus (3D printer) that models a three-dimensional object using an additive manufacturing method. The modeling apparatus used in this embodiment is, for example, a fused deposition modeling (FDM) apparatus that melts and layers pellets made of thermoplastic resin.

[0030] 1, the X direction is defined as the "left-right direction," the Y direction is defined as the "front-rear direction," and the Z direction perpendicular to the X and Y directions is defined as the "up-down direction."

[0031] (Overview of the modeling apparatus 100) As shown in FIG. 1 , the modeling apparatus 100 is formed by assembling a plurality of housing units. The modeling apparatus 100 includes a bottom housing unit 10, a pair of side housing units 20, a pair of upper beam units 30 connecting the pair of side housing units 20, an upper housing unit 40 mounting a first print head 1A and a second print head 1B as working heads, a modeling table 50 on which a modeled object is placed, and a control unit 300. The first print head 1A and the second print head 1B melt pellets made of thermoplastic resin and eject them toward the modeling table 50. The bottom housing unit 10, the side housing unit 20, the upper beam unit 30, the upper housing unit 40, and the modeling table 50 are housing units that form the housing of the modeling apparatus 100.

[0032] A pair of side housing units 20, aligned left and right, are installed on the edges of the top surface of the bottom housing unit 10 and form the sides of the modeling apparatus 100. Each of the pair of side housing units 20 has an elevating mechanism 200 in the center. The pair of elevating mechanisms 200 move the modeling table 50 up and down.

[0033] The pair of upper beam units 30 extend in the left-right direction and are arranged facing each other in the front-rear direction. The pair of upper beam units 30 connect the upper parts of the pair of side housing units 20.

[0034] The upper housing unit 40 includes a frame portion 41 and a print head drive mechanism 400 disposed on the upper surface of the frame portion 41. The frame portion 41 is a frame-shaped member formed in a rectangular shape.

[0035] The print head drive mechanism 400 includes a first print head drive mechanism 410 that drives the first print head 1A and a second print head drive mechanism 420 that drives the second print head 1B. The first print head 1A is moved in the front-to-back and left-to-right directions by the first print head drive mechanism 410 under the control of the control unit 300, as indicated by the solid arrows. The second print head 1B is moved in the front-to-back and left-to-right directions by the second print head drive mechanism 420 under the control of the control unit 300, as indicated by the dashed arrows. In this embodiment, the modeling apparatus 100 is a dual-head modeling apparatus equipped with two print heads, but a single print head is also acceptable.

[0036] The modeling table 50 is a platform on which a model is placed, and both opposing edges of the platform 50 are attached to the lifting mechanism 200 .

[0037] The molding apparatus 100 includes a plate-shaped reinforcing member 51 on the outside of the molding apparatus 100 to reinforce the joint between the bottom case unit 10 and the side case unit 20. Furthermore, the molding apparatus 100 includes a plate-shaped reinforcing member 52 on the outside of the molding apparatus 100 to reinforce the joint between the side case unit 20 and the upper beam unit 30.

[0038] The control unit 300 controls the operation of each unit of the modeling apparatus 100. The control unit 300 is composed of a CPU (Central Processing Unit), a memory, etc. The control unit 300 executes a modeling process in accordance with a preset program.

[0039] (About the configuration of print heads 1A and 1B) Next, we will explain the print heads 1A and 1B, which are components of the modeling apparatus 100. Note that the print heads 1A and 1B basically have the same configuration, and to avoid redundant description, only the print head 1A will be explained below.

[0040] As shown in Figure 2, the print head 1A has a mixing and dispensing unit 80 that mixes the material and dispenses it onto the modeling table 50, and a support unit 90 that supports the mixing and dispensing unit 80 and attaches it to the first print head drive mechanism 410.

[0041] The support unit 90 has a first support plate 91 attached to the first print head drive mechanism 410, a second support plate 92 arranged parallel to the first support plate 91 and spaced apart in the vertical direction, and four connecting pillars 93 connecting the first support plate 91 and the second support plate 92.

[0042] The kneading and discharging unit 80 heats and melts natural pellets supplied as a modeling material while transporting the pellets, and kneads the pellets with a colorant near the discharge port to discharge the material colored to a desired color onto the modeling table 50. As shown in Figures 2 and 3, the kneading and discharging unit 80 includes a material input section 81 into which the material is input, a barrel 82 to which the material input from the material input section 81 is supplied, a screw 83 that rotates within the barrel 82 and transports the molten material as it rotates, a motor 84 that drives the screw 83 to rotate, a heater 85 that heats the material in the barrel 82, a nozzle 86 that discharges the material transported by the screw 83, a heat dissipation section 87 that dissipates heat between the heater 85 and the motor 84, and a colorant injection mechanism 60 that injects a colorant fluid into the lower part of the barrel 82.

[0043] The material input section 81 is a cylindrical member with a passage 81a through which the natural pellets pass. This passage 81a leads to a hollow section 82a of the barrel 82. Because the material input section 81 is an inclined passage that descends toward the barrel 82, when the material is carried downward by the screw 83 inside the barrel 82 and the upper part of the hollow section 82a of the barrel 82, i.e., the groove of the supply section 83a of the screw 83 described below, becomes empty, the material input into the material input section 81 naturally slides down into the empty gap in the hollow section 82a of the barrel 82, and the material is replenished inside the barrel 82.

[0044] As shown in FIG. 4, the barrel 82 is a cylindrical member having a circular hollow portion 82a bored out of a cylindrical body. The barrel 82 is arranged with its axis aligned vertically. The barrel 82 has an opening (not shown) that connects the passage 81a of the material feed section 81 with the hollow portion 82a. The barrel 82 also has a lower portion formed with multiple injection holes 82b through which the colorant is injected. These injection holes 82b extend from the outer circumferential surface of the barrel 82 to the hollow portion 82a, and the number of injection holes 82b is equal to the number of colorant injection mechanisms 60 that can be installed. For example, to share a cleaning path, the injection holes 82b may be located at the same height as possible across the barrel 82.

[0045] The screw 83 has its upper end connected to a motor 84 and its tip housed in a nozzle 86, and as shown in Figure 5, from the upper end to the tip, it has, in order, a supply section 83a, a compression section 83b, a metering section 83c, and a kneading section 83d.

[0046] The supply section 83a, the compression section 83b and the metering section 83c are provided with spiral grooves that extend continuously across these areas.

[0047] The supply section 83a is supplied with the unmelted material that has been supplied from the material input section 81 to the barrel 82. The depth of the grooves in the supply section 83a is equal to or greater than the depth of the grooves in the compression section 83b and the metering section 83c. As long as the supply section 83a can hold the unmelted material, which is bulkier than the molten material, the depth of the grooves in the supply section 83a may be constant from the upper end of the screw 83 toward the tip, or may vary, for example, become gradually shallower.

[0048] In compression section 83b, the material transferred from supply section 83a is further transferred to metering section 83c while being melted by heating by heater 85. The depth of the grooves in compression section 83b gradually becomes shallower toward the tip. Therefore, the volume of the grooves in compression section 83b gradually decreases toward the tip, and the material transferred through the grooves in compression section 83b toward metering section 83c is compressed in the process.

[0049] In the metering section 83c, the material transferred from the compression section 83b is transferred to the kneading section 83d at a constant flow rate. The depth of the grooves in the metering section 83c is equal to or less than the depths of the supply section 83a and the compression section 83b. The depth of the grooves in the metering section 83c is constant, for example, from the upper end to the tip of the screw 83 so that the flow rate of the material transferred to the kneading section 83d, i.e., the volume of material transferred per unit time, is constant. Note that the flow rate of the material in the kneading section 83d (described later) without taking the metering section 83c into consideration is slower than the flow rate of the material in the metering section 83c, and therefore the flow rate of the material in the metering section 83c determines the flow rate of the material discharged from the nozzle 86 via the kneading section 83d.

[0050] The kneading section 83d kneads the material and the colorant, and includes, for example, a rough mixing section 83da and a homogenizing section 83db as shown in FIG.

[0051] The coarse mixing section 83da is located inside the barrel 82 directly below the injection hole 82b that connects to the colorant injection mechanism 60, and coarsely mixes the colorant injected into the barrel 82 from the colorant injection mechanism 60 with the material transferred from the metering section 83c. The mixture of material and colorant is transferred to the homogenizing section 83db by the pressure of the material transferred from the metering section 83c. The coarse mixing section 83da has, for example, a gentle spiral groove with a smaller twist angle than the metering section 83c.

[0052] The homogenizing unit 83db kneads the mixture of the material and the colorant transferred from the rough mixing unit 83da until the colorant is uniformly dispersed in the material. The homogenizing unit 83db has, for example, a plurality of protrusions.

[0053] The motor 84 is, for example, a servo motor, a stepping motor, or the like, and can rotate an output shaft (not shown) at different rotational speeds under the control of the control unit 300.

[0054] 2 to 4, heaters 85 are provided on the outer periphery of barrel 82, and heat the material and colorant supplied inside barrel 82. Four heaters 85 are arranged in barrel 82 in the longitudinal direction.

[0055] 2 to 4, the nozzle 86 is connected to the lower end of the barrel 82. The tip of the screw 83 is inserted into the nozzle 86. The material transported by the screw 83 is discharged from the nozzle 86 onto the modeling table 50.

[0056] 3 and 4, the heat dissipation unit 87 is connected to the upper end of the barrel 82. The heat dissipation unit 87 dissipates some or all of the heat transferred from the heater 85 through the barrel 82 and the screw 83 to the motor 84 and the connecting parts between the motor 84 and the screw 83. This prevents the motor 84 and the connecting parts between the motor 84 and the screw 83 from being damaged by heat.

[0057] As shown in Fig. 2, the colorant injection mechanisms 60 are attached to the outer edge of the second support plate 92. In this embodiment, five colorant injection mechanisms 60 that have the same configuration and can be controlled independently are attached. As shown in Fig. 6, the colorant injection mechanisms 60 include a colorant supply unit 61 and a colorant kneading unit 62.

[0058] The colorant supply unit 61 accommodates colored pellets, preheats them, and at least partially melts them before supplying them to the colorant kneading unit 62. The colorant supply units 61 of the colorant injection mechanisms 60 accommodate colored pellets of different colors. As shown in FIGS. 6 and 7 , the colorant supply unit 61 includes a hopper 61a that accommodates the colored pellets, a screw cap 61b that seals the hopper 61a, and a heater 61c attached to the periphery of the hopper 61a. The hopper 61a includes a hollow portion 61d that tapers toward the coloring barrel 62a. The screw cap 61b includes an air passage 61e that is connected to an air compressor (not shown). When colored pellets are added to the colorant supply unit 61, the screw cap 61b is removed from the hopper 61a. Otherwise, the screw cap 61b seals the hopper 61a.

[0059] The colorant kneading unit 62 heats and kneads the colorant supplied from the colorant supply unit 61, and injects the kneaded colorant into the barrel 82. As shown in Figures 6 and 7, the colorant kneading unit 62 includes a coloring barrel 62a to which the colorant is supplied from the colorant supply unit 61, a heater 62b attached to the periphery of the coloring barrel 62a, a screw 62c that rotates within the coloring barrel 62a, a motor 62d that rotates the screw 62c, a connection unit 62e that connects the screw 62c to the motor 62d, and a nozzle 62f from which the molten colorant is ejected.

[0060] When the colorant injection mechanism 60 injects molten colored pellets as a colorant into the barrel 82, the heater 61c attached to the periphery of the hopper 61a first at least partially melts the colored pellets in the hollow portion 61d. The molten colored pellets are supplied to the coloring barrel 62a by the pressure of air sent from the air passage 61e of the screw cap 61b, against the pressure inside the coloring barrel 62a. Under the control of the control unit 300, the motor 62d drives the screw 62c to rotate, and the colored pellets supplied to the coloring barrel 62a are further heated by the heater 62b attached to the periphery of the coloring barrel 62a and then injected into the barrel 82 through the injection hole 82b shown in FIG. 3.

[0061] Furthermore, when colorant is not injected into the barrel 82 from the colorant injection mechanism 60, the pressure inside the coloring barrel 62a is reduced, so that the material being transported and pressurized by the screw 83 inside the barrel 82 does not flow back into the colorant injection mechanism 60 from the injection hole 82b by applying pressure to the molten colorant inside the colorant supply section 61 and the colorant kneading section 62 using air supplied from an air compressor.

[0062] (About the modeling method using the modeling apparatus 100) Next, we will explain a modeling method using the modeling apparatus 100. In this modeling method, the control unit 300 controls the first print head drive mechanism to cause the first print head 1A to scan the XY plane on the modeling table 50, and during this process, controls the discharging of modeling material by the first print head 1A based on modeling data for forming a modeled object. In other words, the control unit 300 causes the first print head 1A to discharge material when the relative positions of the modeling table 50 and the first print head 1A are at the position where the material should be discharged.

[0063] Furthermore, when a predetermined color other than the color of the natural pellets is to be imparted to the material being dispensed from the first print head 1A to a predetermined position on the modeling table 50, the control unit 300 controls the colorant injection mechanism 60 of the first print head 1A according to the color prior to dispensing the material. That is, the control unit 300 injects colorant into the barrel 82 from one or more colorant injection mechanisms 60 corresponding to a single colorant or a combination of multiple colorants capable of imparting that color to the material in an amount sufficient to reproduce the shade and hue of that color. For example, when coloring a material green, the control unit 300 controls the colorant injection mechanism 60 containing a cyan colorant and the colorant injection mechanism 60 containing a yellow colorant to inject the same amount of colorant into the barrel 82 from these mechanisms. Furthermore, when the color of the material being dispensed from the first print head 1A to a predetermined position on the modeling table 50 is to be returned to the color of the natural pellets, the control unit 300 stops the injection of colorant by the colorant injection mechanism 60 prior to dispensing the material.

[0064] If necessary, when changing the color of the material dispensed from the first print head 1A to a predetermined position on the modeling table 50, the control unit 300 may perform a so-called trial injection operation by controlling the first print head drive mechanism to move the first print head 1A to a modeling material disposal unit (not shown), then controlling the colorant injection mechanism 60 to change the color of the material to the desired color, then causing the first print head 1A to dispense the material of the previous color remaining in the barrel 82 and nozzle 86 to the modeling material disposal unit, and then controlling the first print head drive mechanism to return the first print head 1A to a predetermined position on the modeling table 50. Note that when the color of the material is to be continuously changed, for example, when gradation is to be expressed, the trial injection operation may not be performed, and the amount of colorant dispensed from the colorant injection mechanism 60 to the barrel 82 may be continuously changed depending on the position of the modeling table 50.

[0065] If the object is a three-dimensional object having thickness in the Z direction, the control unit 300 forms the layers that make up the object one by one using the above process, and maintains a constant distance between the first print head 1A and the forming table 50 by lowering the forming table 50 in the Z direction by the thickness of one layer each time a layer is formed.

[0066] (Effects of this embodiment) According to the modeling apparatus 100 of this embodiment, a model can be suitably manufactured.

[0067] For example, in the modeling apparatus 100, the colorant injection mechanism 60 injects the colorant into the barrel 82 near the nozzle 86, which shortens the distance over which the material in the barrel 82 is colored compared to conventional methods. Therefore, the modeling apparatus 100 allows color switching and barrel cleaning to be performed in a short time.

[0068] Furthermore, in the molding apparatus 100, color unevenness is less likely to occur because the colorant fluid is injected into the molten material and then kneaded.

[0069] Furthermore, in the modeling apparatus 100, the melting of the modeling material by the kneading and discharging unit 80 and the melting of the colored pellets by the colorant injection mechanism 60 can be controlled independently. This allows the melting of the modeling material and the colored pellets to be performed at their respective optimal melting temperatures.

[0070] Furthermore, in the molding device 100, the extrusion and kneading of the material are performed using the same screw 83, and therefore, unlike when the extrusion and kneading of the material are performed using separate screws, the rotation speed of the screw for extrusion and the rotation speed of the screw for kneading are the same, resulting in high reproducibility of the kneading results.

[0071] Furthermore, since the molding apparatus 100 includes a plurality of colorant injection mechanisms 60 that inject colorants of different colors into the barrel 82, it is possible to reproduce an infinite number of colors by combining a plurality of colorants.

[0072] Furthermore, in the molding device 100, the colorant injection mechanism 60 preheats the colorant in the colorant supply section 61 to at least partially melt it, and then the colorant is completely heated and kneaded in the colorant kneading section 62, so that the colorant can be melted well even in a relatively small colorant kneading section.

[0073] In addition, in the molding apparatus 100, the barrel 82 and screw 83 of the kneading and discharging unit 80 are arranged vertically, so that gravity causes the material in the barrel 82 to move downward and air bubbles, such as air, which have a lower density than the material, to move upward. Therefore, compared to when the barrel 82 and screw 83 of the kneading and discharging unit 80 are arranged horizontally, the driving load on the screw 83 is reduced and the amount of air bubbles remaining in the barrel 82 is also reduced.

[0074] The present invention is not limited to the above-described embodiment, and various modifications and applications are possible. In the above-described embodiment, the colorant injection mechanism 60 injects the colorant into the barrel 82 near the nozzle 86. However, the colorant fluid may be injected into the barrel 82 and / or the nozzle 86 at any position between the position where the material is supplied to the barrel 82 and the position where it is discharged from the nozzle 86, for example, at the position of the metering section 83c and / or the kneading section 83d of the screw 83.

[0075] In the above embodiment, natural pellets are used as the material for molding, but pellets of thermoplastic resin containing additives such as colorants may also be used, or materials other than thermoplastic resin may be used as long as they can be ejected by heating and kneading.

[0076] In the above embodiment, a fluid of molten colored pellets is used as the colorant, but other colorants may be used as long as they can be discharged by heating and kneading.

[0077] In the above embodiment, the colorant fluid is injected into the barrel 82 using the colorant injection mechanism 60. However, any device that injects the colorant from the side of the barrel 82, such as a side feeder, liquid feeder, or extruder, may also be used. In this case, instead of using a molten solid colorant, a fluid colorant, such as a liquid or sol, may be used. Note that in the following modified examples, the colorant injection mechanism 60 may be any device that injects the colorant from the side of the barrel 82.

[0078] Any means may be used to supply colorant to colorant injection mechanism 60. For example, a colorant supply device may be provided that supplies colorant to colorant injection mechanism 60 when the remaining amount of colorant in colorant injection mechanism 60 becomes low, particularly when the remaining amount is less than or equal to a predetermined remaining amount (but the predetermined remaining amount is greater than 0). This prevents colorant from running out in colorant injection mechanism 60.

[0079] The colorant supply device may be, for example, a colorant supply device 63 including a colorant master batch storage section 63a and a metering device 63b, as shown in FIG.

[0080] The colorant masterbatch storage unit 63a stores a colorant of a predetermined color and may have a larger capacity than, for example, the colorant supply unit 61 of the colorant injection mechanism 60 or the colorant supply unit of the device that injects the colorant. Any means may be used to supply the colorant from the colorant masterbatch storage unit 63a to the metering device 63b, but the colorant masterbatch storage unit 63a may be installed above the metering device 63b in the direction of gravity, and the colorant masterbatch storage unit 63a and the metering device 63b may be connected to each other by a pipeline or the like so that the colorant falls by gravity from an outlet 63aa of the colorant masterbatch storage unit 63a to an inlet 63ba of the metering device 63b.

[0081] When the amount of colorant remaining in the colorant injection mechanism 60 becomes low, particularly when it becomes less than a predetermined remaining amount or equal to or less than the predetermined remaining amount (however, the predetermined remaining amount is greater than 0), the metering device 63b measures out the colorant supplied from the inlet 63ba as described above and supplies a predetermined amount of colorant from the outlet 63bb to the colorant injection mechanism 60. The outlet 63bb of the metering device 63b is connected to the colorant supply unit 61 of the colorant injection mechanism 60 or the colorant supply unit of the device that injects the colorant by a pipe or the like so that the colorant can flow therethrough.

[0082] The metering device 63b may have any configuration as long as it can supply a predetermined amount of colorant. For example, as shown in FIG. 8, the inlet 63ba of the metering device 63b may be located above the outlet 63bb in the direction of gravity, and the metering device 63b may be installed above the colorant injection mechanism 60 in the direction of gravity. The metering device 63b and the colorant injection mechanism 60 may be connected by a conduit or the like so that the colorant falls by gravity from the outlet 63bb to the colorant supply unit 61 of the colorant injection mechanism 60 or the colorant supply unit of the colorant injection device. The metering device 63b may include a rotatable metering unit 63bc that is mechanically or electronically controlled and is provided within the socket 63bd. The center line connecting the center of the inlet 63ba and the center of the outlet 63bb may be approximately perpendicular to the direction of gravity.

[0083] The metering unit 63bc has a surface 63bca and a recess 63bcb. The surface 63bca abuts the socket 63bd or is separated from the socket 63bd by a gap large enough to prevent colorant from flowing in. The recess 63bcb can hold a predetermined amount of colorant and opens toward the inlet 63ba when the metering unit 63bc faces upward along the direction of gravity. The recess 63bcb opens toward the outlet 63bb when the metering unit 63bc faces downward along the direction of gravity. Under the control of the control unit 300, when the remaining amount of colorant in the colorant injection mechanism 60 becomes low—for example, when the remaining amount is less than or equal to a predetermined amount (but the predetermined amount is greater than zero)—the modeling apparatus 100 rotates the metering unit 63bc, using an electric motor or the like, from a position in which the recess 63bcb opens toward the inlet 63ba to a position in which the recess 63bcb opens toward the outlet 63bb. Then, the colorant in the recess 63bcb falls to the outlet 63bb by gravity, and is then supplied to the colorant injection mechanism 60.

[0084] The method for determining whether the remaining amount of colorant in the colorant injection mechanism 60 has become low, for example, whether it has become less than a specified remaining amount or equal to or less than a specified remaining amount (however, the specified remaining amount is greater than 0), is arbitrary, and may be determined indirectly based on, for example, the usage history of the colorant, or may be determined directly based on the remaining amount of colorant in the colorant injection mechanism 60 measured by a sensor provided in the colorant injection mechanism 60, such as a weight sensor or optical sensor.

[0085] In the above embodiment, the kneading and discharging unit 80 is used, but except for the point that the colorant fluid is injected at a predetermined position, a configuration similar to the kneading and discharging unit of the discharge head used in a conventional modeling apparatus or a configuration equivalent thereto can be adopted. Furthermore, the configuration of the modeling apparatus 100 excluding the kneading and discharging unit 80 can be the configuration of a conventional fused deposition modeling apparatus.

[0086] The means for supplying materials such as natural pellets to the material input section 81 is arbitrary, and for example, the material supply section that supplies the material may be connected to the material input section 81 directly or indirectly via a passage such as a pipe, in a closed or open manner.

[0087] A shutoff mechanism for shutting off the supply of material to barrel 82 may be provided in molding apparatus 100, for example, in material input section 81, barrel 82, and / or the material supply section described above.

[0088] The surface of the hollow portion 82a of the barrel 82, the inner surface of the nozzle 86, and / or the surface of the screw 83 may be subjected to a surface treatment, such as an oxo treatment, to prevent the molten material from sticking together. In this case, the molten material can be more easily extruded from the barrel 82. In particular, even if the viscosity of the molten material in the barrel 82 is higher than expected due to deterioration of the material or the like, the molten material can be extruded from the barrel 82 without clogging.

[0089] In order to reduce the extrusion resistance when extruding the molten material from the barrel 82, the screw 83 may be provided with an additional kneading section such as a Unimelt, for example, between the supply section 83a and the compression section 83b of the screw 83. In this case, the molten material can be more easily extruded from the barrel 82. In particular, even if the viscosity of the molten material in the barrel 82 is higher than expected due to deterioration of the material or the like, the molten material can be extruded from the barrel 82 without clogging.

[0090] The barrel 82 may be equipped with an internal sealing mechanism for airtightly sealing the rear end of the hollow portion 82a of the barrel 82 (the end opposite to the end connected to the nozzle 86) when necessary. Additionally or alternatively, the barrel 82 may be configured so that the rear end of the hollow portion 82a of the barrel 82 is always airtightly sealed. In either case, if the supply of material to the barrel 82 is stopped and the material continues to be extruded from the barrel 82 while the rear end of the hollow portion 82a of the barrel 82 is airtightly sealed, the air at the rear end of the hollow portion 82a of the barrel 82 is heated and expands, and this expanded air promotes the extrusion of the material from the barrel 82. This makes it easier to extrude the molten material from the barrel 82. In particular, even if the viscosity of the molten material in the barrel 82 is higher than expected due to deterioration of the material, the molten material can be extruded from the barrel 82 without clogging.

[0091] The modeling apparatus 100 may be configured to perform a barrel emptying process under the control of the control unit 300 when, during modeling, the barrel 82 is heated, for example, to the melting temperature of the material, but no material is extruded from the barrel 82 for a predetermined time or longer. The predetermined time is set, for example, so as to prevent deterioration of the material due to heating, so that the material's properties, such as the viscosity and solidification of the heated material, the strength and crystallinity of the material after hardening, and the appearance of the modeled object, can be maintained even if deterioration of the material occurs due to heating. The predetermined time varies depending on the material, but for example, if the material is polypropylene, the predetermined time is any time equal to or greater than 20 minutes, such as 30 minutes.

[0092] For this reason, for example, the molding apparatus 100, and in particular the control unit 300, may include a timer that measures the time during which the barrel 82 is heated, for example, to the melting temperature of the material, but no material is being extruded from the barrel 82. In this case, when the time measured by the timer reaches or exceeds a predetermined time, the molding apparatus 100 performs a barrel emptying process under the control of the control unit 300.

[0093] (Barrel emptying process) The barrel emptying process mainly includes a material supply stopping step, a barrel temperature increasing step, and a material extrusion step. These three steps may be performed in this order or in parallel, or the material supply stopping step and the barrel temperature increasing step may be performed in any order or in parallel before the material extrusion step.

[0094] (Material supply stop process) In the material supply stopping process, the supply of material to the barrel 82 is stopped. For example, if a user has manually supplied material to the barrel 82 via the material input unit 81, the user stops the supply. Also, if material has been automatically supplied to the barrel 82 via the material input unit 81 from the above-mentioned material supply unit or the like, the material supply unit or the shutoff mechanism of the above-mentioned modified example or the like stops the supply of material to the barrel 82 under the control of the control unit 300.

[0095] (Barrel heating process) In the barrel heating process, the material in the barrel 82 is heated to a predetermined temperature that exceeds the melting temperature of the material. For example, under the control of the control unit 300, the heater 85 heats the material in the barrel 82 to a predetermined temperature that exceeds the melting temperature of the material, for example, for a predetermined heating time. The predetermined temperature is any temperature that is 20°C higher than the melting temperature of the material. For example, if the material is polypropylene, the predetermined temperature is any temperature that is 180°C or higher, for example, 200°C.

[0096] (Material extrusion process) In the material extrusion process, the material is extruded from the barrel 82 to substantially empty it. For example, under the control of the control unit 300, the molding apparatus 100 rotates the screw 83, for example, at a higher speed than during normal molding, for example, at the highest speed, for example, for a predetermined rotation time until the barrel 82 is empty. After the barrel 82 is emptied, the remaining volume of the material in the barrel 82 is preferably less than 1% of the volume of the hollow portion 82a of the barrel 82.

[0097] (Other processes) After the barrel emptying process, the molding apparatus 100 ends or suspends molding under the control of the control unit 300. The end or suspension of molding includes stopping the heating of the barrel 82 by the heater 85.

[0098] In the case of barrel emptying treatment over time, a step of heating the material in the barrel 82 to the melting temperature of the material may be provided instead of the barrel temperature increase step. Furthermore, a configuration or step for more easily extruding the molten material from the barrel 82, such as the above-described modified example, may be combined with the barrel emptying treatment. For example, the barrel emptying treatment may include a step of airtightly sealing the barrel 82, particularly the rear end of the hollow portion 82a of the barrel 82, using the above-described internal barrel sealing mechanism or the like.

[0099] Prolonged heating above the melting temperature can alter the material, potentially changing its properties. For example, the altered material may become more viscous in the molten state, or may not fully melt at the desired melting temperature and may remain solid. The resulting hardened material may also exhibit changes in strength, crystallinity, and the appearance of the resulting object. The barrel emptying process, which occurs over time, avoids these problems by preventing the material in the barrel 82 from deteriorating.

[0100] In addition to or instead of the barrel emptying process over time, the molding apparatus 100 may be configured to perform the above-described barrel emptying process when cleaning the barrel 82 under the control of the control unit 300.

[0101] In the case of cleaning the barrel 82, after the barrel emptying process, the molding apparatus 100 resumes molding under the control of the control unit 300. Resuming molding includes a step of lowering the heating temperature of the barrel 82 by the heater 85 and heating the material in the barrel 82 to the melting temperature of the material, and a step of resuming the supply of material to the barrel 82.

[0102] The barrel emptying process by cleaning the barrel 82 may be combined with a configuration or process such as the above-described modified example for more easily extruding the molten material from the barrel 82. For example, the barrel emptying process may include a process of airtightly sealing the barrel 82, particularly the rear end of the hollow portion 82a of the barrel 82, using the above-described internal barrel sealing mechanism or the like. In this case, resuming modeling may include a process of releasing the seal on the barrel 82.

[0103] If a material is altered for some reason, and its material properties change, various problems can occur. For example, the altered material may have a higher viscosity in the molten state, or may not melt sufficiently at the specified melting temperature and may remain solid in some cases. Furthermore, the strength, crystallinity, and appearance of the hardened material may change. By performing a barrel emptying process by cleaning the barrel 82, the altered material remains inside the barrel 82 during modeling after cleaning, preventing any adverse effects of the altered material on the modeling process or the model.

[0104] The features described in the above-described embodiments and modifications can be combined in any manner unless they are inconsistent. [Explanation of symbols]

[0105] 1A First print head 1B Second print head 10 Bottom housing unit 20 Side housing unit 30 Upper beam unit 40 Upper housing unit 41 Frame section 50 Modeling stand 51,52 Reinforcement member 60 Colorant injection mechanism 61 Colorant supply unit 61a Hopper 61b screw cap 61c Colorant supply heater 61d Hollow part of hopper 61e Screw cap air passage 62 Colorant mixing section 62a Coloring Barrel 62b Heater for colorant kneading section 62c Screw for colorant mixing section 62d Motor for colorant mixing section 62e Connection between screw and motor in colorant mixing section 62f Nozzle for colorant mixing section 63 Colorant supply device 63a Colorant masterbatch storage section 63aa Colorant masterbatch storage outlet 63b Quantification device 63ba Inlet of the metering device 63bb Outlet of the metering device 63bc Quantification Department 63bca Surface of the quantification section 63bcb Recessed portion of the metering section 63bd socket 80 Mixing and discharging unit 81 Material input section 81a Passageway 82 barrels 82a Hollow part 82b Injection hole 83 Screw 83a Supply section 83b Compression section 83c Measuring part 83d Mixing section 83da coarse mixing section 83db equalization section 84 Motor of mixing and discharging unit 85 Heater for mixing and discharging unit 86 nozzles 87 Heat radiation part 90 Support Unit 91 First support plate 92 Second support plate 93 Connecting column 96 nozzles 100 Modeling equipment 200 Lifting mechanism 300 control section 400 Printhead drive mechanism 410 First Print Head Drive Mechanism 420 Second Print Head Drive Mechanism

Claims

1. a barrel into which material for molding is supplied; a heater that heats the material supplied into the barrel; a rotating screw provided in the barrel for transporting the material heated by the heater; a nozzle for discharging the material transported by the screw; a colorant injection mechanism that injects a colorant fluid into the barrel and / or the nozzle between a position where the material is supplied to the barrel and a position where the material is discharged from the nozzle, Modeling equipment.

2. the colorant injection mechanism injects the colorant into the barrel and / or the nozzle near the nozzle; The molding apparatus according to claim 1 .

3. The screws are arranged in the following order from the top end to the tip: a supply section to which the material before melting is supplied; a compression section that compresses the molten material; a metering section that transfers the compressed material at a constant flow rate; a kneading section for kneading the material and the colorant; Equipped with the colorant injection mechanism injects the colorant into the barrel and / or the nozzle at a position where the metering unit or the kneading unit is accommodated; The molding apparatus according to claim 1 .

4. a plurality of colorant injection mechanisms for injecting colorants of different colors into the barrel; The molding apparatus according to claim 1 .

5. the colorant injection mechanism includes a colorant supply unit and a colorant kneading unit; the colorant supplying section preheats the colorant to at least partially melt it and supplies it to the colorant kneading section; the colorant kneading unit heats and kneads the colorant supplied from the colorant supply unit, and injects the kneaded colorant into the barrel; The molding apparatus according to claim 1 .

6. a colorant supply device that supplies colorant to the colorant injection mechanism when the remaining amount of colorant in the colorant injection mechanism falls below a predetermined remaining amount; The molding apparatus according to claim 1 .

7. From the top to the tip, in order: a supply unit to which a pre-melted modeling material is supplied; a compression section that compresses the molten material; a metering section that transfers the compressed material at a constant flow rate; a kneading section for kneading the material and the colorant; Equipped with A screw for use in the molding apparatus of claim 3.

8. An operating method performed by the molding apparatus according to claim 1, When the time during which the material is not extruded from the barrel while the barrel is heated during modeling exceeds a predetermined time, a material supply stopping step of stopping the supply of the material to the barrel; a material extruding step forcing the material out of the barrel to substantially empty the barrel; A driving method comprising:

9. An operating method performed by the molding apparatus according to claim 1, When cleaning the barrel, a material supply stopping step of stopping the supply of the material to the barrel; a barrel heating step of heating the material in the barrel to a predetermined temperature exceeding the melting temperature of the material; a material extruding step forcing the material out of the barrel to substantially empty the barrel; A driving method comprising:

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