JP6879802B2 - Three-dimensional laminated modeling equipment - Google Patents

Description

The present invention relates to a three-dimensional laminated molding apparatus.

A laminated modeling apparatus that manufactures a three-dimensional model by repeating layer formation of a powder material and solidification of a predetermined portion of the powder material layer is known.

As such a laminated molding device, for example, a laminated molding device including a recorder unit for storing sand as a powder material and a print head unit for discharging a binder for binding sand has been proposed (for example, a patent). See Reference 1.).

Then, in such a laminated modeling device, the recorder unit moves and sand is sprinkled on the modeling table to form a sand layer, and then the print head unit discharges and applies a binder onto the sand layer. Solidify the binder-coated part of the sand layer.

Japanese Unexamined Patent Publication No. 2015-189835

However, in the laminated modeling apparatus described in Patent Document 1, sand may not be uniformly stored inside the recorder unit and may be biased. In this case, if the recorder unit sprinkles sand to form a sand layer, the thickness of the sand layer becomes uneven due to the unevenness of the sand inside the recorder unit, and there is a possibility that accurate modeling cannot be performed.

Therefore, the present invention provides a three-dimensional laminated molding apparatus capable of forming a powder material into layers with high accuracy and improving the accuracy of a modeled object.

The present invention [1] is a three-dimensional laminated molding apparatus that repeatedly forms a layer of a powder material and then solidifies the layer of the powder material, and can store the powder material. A discharge unit that discharges the stored powder material in layers and a control unit that controls the operation of the discharge unit are provided, and the discharge unit includes a container capable of storing the powder material and a container that can store the powder material. A screw member that is rotatable with respect to the container and that conveys the powder material in the container in the direction in which the rotation axis extends is provided, and the control unit sets the rotation direction of the screw member in the first direction. It includes a three-dimensional laminated molding apparatus that controls the rotation direction so as to be switchable between the first rotation direction and the second rotation direction opposite to the first rotation direction.

However, as shown in FIG. 3A, the container of the discharge unit stores the powder material by being supplied with the powder material. The powder material stored in the container may be biased toward the supply port formed in the container. Therefore, as shown in FIG. 3B, it is considered to provide a screw member in the container to convey the powder material.

However, when the powder material is transported by the screw member, the powder material may be accumulated in the downstream portion in the transport direction of the powder material, and the powder material may not be uniformly stored inside the container.

On the other hand, according to the above configuration, the control unit controls the rotation direction of the screw member so as to be switchable between the first rotation direction and the second rotation direction opposite to the first rotation direction. Therefore, after rotating the screw member in the first rotation direction and transporting the powder material from one side in the extending direction of the rotation axis toward the other side, the rotation direction of the screw member is switched to the second rotation direction. Therefore, the powder material can be conveyed from the other side in the extending direction of the rotation axis to one side. As a result, the powder material can be uniformly stored inside the container. As a result, the discharge portion can accurately form the powder material in layers, and the accuracy of the modeled object can be improved.

According to the three-dimensional laminated molding apparatus of the present invention, the powder material can be formed into layers with high accuracy, and the accuracy of the modeled object can be improved.

FIG. 1 is a plan view of a 3D printer as an embodiment of the three-dimensional laminated modeling apparatus of the present invention. FIG. 2 is a sectional view taken along the line AA of the recorder shown in FIG. FIG. 3A is a cross-sectional view taken along the line BB of the recorder shown in FIG. 1, showing a state in which the powder material is biased toward the vicinity of the supply port. FIG. 3B shows a state in which the powder material is conveyed by the screw member following FIG. 3A. FIG. 3C shows a state in which the powder material is uniformly stored inside the container, following FIG. 3B. FIG. 4A is a perspective view of the 3D printer shown in FIG. 2, showing a process in which the recorder forms the first powder material layer. FIG. 4B is an explanatory diagram for explaining the process shown in FIG. 4A. FIG. 5A is a perspective view of the 3D printer shown in FIG. 2, showing a step in which the jet head supplies a binder to the first powder material layer. FIG. 5B is an explanatory diagram for explaining the process shown in FIG. 5A. FIG. 6A shows a step of forming a second powder material layer on the first powder material layer, following FIG. 5B. FIG. 6B shows a step of supplying a binder to the second powder material layer following FIG. 6A. FIG. 7A shows a step of forming a modeled object by sequentially repeating layer formation of a powder material and supply of a binder, following FIG. 6B. FIG. 7B is a perspective view of the modeled object shown in FIG. 7A. FIG. 8 is a schematic configuration diagram of cast sand as an embodiment of the powder material stored in the recorder shown in FIG.

<3D printer>
The 3D printer 1 as an embodiment of the three-dimensional laminated modeling apparatus of the present invention will be described with reference to FIGS. 1 to 4B.

The 3D printer 1 is an apparatus capable of modeling a modeled object based on 3D-CAD data. After forming the powder material in layers, a binder is supplied to the powder material layer to form the powder material layer. It is shaped by repeating hardening.

As shown in FIG. 1, the 3D printer 1 includes a modeling unit 10, a recorder 13 as an example of a discharge unit, a jet head 14, and a control unit 20.
(1) Modeling Unit As shown in FIGS. 4A and 4B, the modeling unit 10 includes a job box 11, a stage 12, and a support shaft 18.

The job box 11 has a substantially rectangular frame shape in a plan view, and extends in the vertical direction. The upper end of the job box 11 is open.

The stage 12 has a plate shape having a substantially rectangular shape in a plan view, and is arranged in the job box 11. The stage 12 is fixed to the upper end of a support shaft 18 that can be raised and lowered in the vertical direction. The stage 12 can be moved in the vertical direction in the job box 11 by raising and lowering the support shaft 18.
(2) Recorder As shown in FIGS. 3C and 4B, the recoater 13 is capable of storing powder material, and is configured to discharge the stored powder material in a layered manner on the stage 12. To. The recorder 13 can move in one direction in the plane direction of the stage 12 so as to pass above the stage 12 in a state of being parallel to the stage 12 at intervals. In the following, the direction in which the recorder 13 can move is defined as the horizontal direction (X direction), and the direction orthogonal to both the horizontal direction and the vertical direction is defined as the vertical direction (Y direction).

As shown in FIGS. 2 and 3A, the recorder 13 includes a container 15, a blade 16, and a screw member 21.

The container 15 can store the powder material. The container 15 has a trapezoidal cross section whose lower base is shorter than that of the upper base, and extends in the vertical direction. The container 15 includes a first side wall 15A and a second side wall 15B which are arranged at intervals in the vertical direction, a third side wall 15C and a fourth side wall 15D which are arranged at intervals in the horizontal direction, and a container 15. A bottom wall 15E located at the lower end of the container 15 and an upper wall 15F located at the upper end of the container 15 are provided.

As shown in FIG. 3A, the first side wall 15A is located at one end of the container 15 in the vertical direction. The second side wall 15B is located at the other end of the container 15 in the vertical direction.

As shown in FIG. 2, the third side wall 15C is located at one end of the container 15 in the lateral direction. The third side wall 15C connects one end of the first side wall 15A in the lateral direction and one end of the second side wall 15B in the lateral direction. The lower end of the third side wall 15C is located at a distance from the bottom wall 15E.

The fourth side wall 15D is located at the other end of the container 15 in the lateral direction. The fourth side wall 15D connects the other end of the first side wall 15A in the lateral direction and the other end of the second side wall 15B in the lateral direction.

The bottom wall 15E connects the lower end of the first side wall 15A and the lower end of the second side wall 15B. The bottom wall 15E is continuous with the lower end of the fourth side wall 15D, while being spaced apart from the lower end of the third side wall 15C.

A discharge port 17 for discharging the powder material is partitioned by a lower end portion of the third side wall 15C, a lateral end portion of the bottom wall 15E, and the first side wall 15A and the second side wall 15B. The discharge port 17 is located below the third side wall 15C. The discharge port 17 communicates with the inside and outside of the container 15. The discharge port 17 extends in the vertical direction. The vertical dimension of the discharge port 17 is substantially the same as the vertical dimension of the stage 12.

The upper wall 15F connects the upper end portion of the first side wall 15A and the upper end portion of the second side wall 15B. The upper wall 15F connects the upper end portion of the third side wall 15C and the upper end portion of the fourth side wall 15D.

As shown in FIG. 1, the upper wall 15F has a supply port 19 for receiving the supply of the powder material. The supply port 19 is located at one end of the upper wall 15F in the vertical direction. Although not shown, the supply port 19 is connected to a tank in which the powder material is housed.

As shown in FIG. 2, the blade 16 is arranged in the container 15. The blade 16 regulates the powder material stored in the container 15 from undesirably flowing out. Further, the blade 16 can vibrate so that the powder material is discharged from the discharge port 17 at a desired timing. The blade 16 has an L-shape in a side view, and has a plate 16A and a protruding portion 16B.

The plate 16A is arranged along the third side wall 15C. The protrusion 16B is located near the upper side of the discharge port 17 on the third side wall 15C. The protruding portion 16B protrudes from the lower end portion of the plate 16A toward the fourth side wall 15D. The free end portion (the end portion on the side opposite to the plate 16A) of the protruding portion 16B is arranged laterally spaced apart from the fourth side wall 15D. The distance L between the free end of the protrusion 16B and the fourth side wall 15D in the lateral direction is, for example, 0.3 mm or more, preferably 0.7 mm or more, for example, 6.0 mm or less, preferably 1. It is 5 mm or less.

As shown in FIG. 3A, the screw member 21 is configured to convey the powder material in the container 15 in the vertical direction (an example in the direction in which the rotation axis extends). The screw member 21 is arranged in the container 15. The screw member 21 includes a shaft portion 22 and a screw blade 23.

The shaft portion 22 has a substantially cylindrical shape extending in the vertical direction. Both ends of the shaft portion 22 in the vertical direction are rotatably supported by the first side wall 15A and the second side wall 15B.

The screw blade 23 is provided on the peripheral surface of the shaft portion 22, and is located between the first side wall 15A and the second side wall 15B. The screw blade 23 has a spiral shape extending clockwise from one side in the vertical direction toward the other side.

The screw member 21 is rotatable with respect to the container 15 about an axis extending in the vertical direction. Specifically, the screw member 21 is rotatable in a first rotation direction and a second rotation direction opposite to the first rotation direction. When the screw member 21 rotates in the first rotation direction, the powder material in the container 15 is conveyed from one side to the other side in the vertical direction (an example of the direction in which the axis extends). When the screw member 21 rotates in the second rotation direction, the powder material in the container 15 is conveyed from the other side in the vertical direction toward one side.

(3) Powder material As shown in FIG. 3C, the powder material is stored in the container 15 of the recoater 13. Specifically, the powder material is stored in the space above the protrusion 16B of the blade 16 inside the container 15. The powder material is not particularly limited, and examples thereof include known modeling materials applicable to three-dimensional laminated modeling. Examples of the powder material include casting sand, resin particles, ceramic particles, glass powder and the like, and preferably casting sand.

Examples of the casting sand include mixed sand of sand (described later) and a curing agent (described later), casting sand 2 shown in FIG. 8, and preferably casting sand 2 shown in FIG.

As shown in FIG. 8, the casting sand 2 is a curing agent composed of sand 3, a surface modification layer 4 containing a resin cured product covering the sand 3, and a curing agent adhering to the surface of the surface modification layer 4. It includes a layer 5.

Examples of the sand 3 include natural silica sand and artificial sand.

Examples of the cured resin product contained in the surface modification layer 4 include furan resin, phenol resin, epoxy resin, silicone resin, and resole type phenol resin, and furan resin is preferable from the viewpoint of heat resistance.

The curing agent of the curing agent layer 5 contains, for example, an acid catalyst that cures a binder described later. As the acid catalyst, for example, an aliphatic sulfonic acid (for example, methanesulfonic acid, ethanesulfonic acid, etc.), an aromatic sulfonic acid (for example, benzenesulfonic acid, paratoluenesulfonic acid, xylenesulfonic acid, etc.), an inorganic acid (for example, xylenesulfonic acid, etc.), an inorganic acid (for example, Examples include sulfuric acid, phosphoric acid, hydrochloric acid, etc.), carboxylic acid (eg, maleic acid, oxalic acid, etc.) and the like. The acid catalyst can be used alone or in combination of two or more.

Casting sand 2 can be prepared by mixing sand and a resin composition corresponding to the above-mentioned cured resin product, and then adding a curing agent.

(4) Jet Head As shown in FIGS. 5A and 5B, the jet head 14 is configured to supply a binder to a layer of powder material formed on the stage 12. Although not shown, the jet head 14 is connected to a binder tank accommodating a binder, and the binder is replenished from the binder tank. The jet head 14 is movable in the vertical and horizontal directions so as to pass above the stage 12 in a state of being parallel to the stage 12 at intervals.

The binder is not particularly limited as long as it can solidify the powder material. Examples of the binder include a furan resin composition, a phenol resin composition, an alkaline phenol resin composition and the like, and preferably a furan resin composition and the like.

(5) Control Unit As shown in FIG. 1, the control unit 20 is configured to control the operations of the recorder 13 and the jet head 14. Further, the control unit 20 can switch the rotation direction of the screw member 21 between the first rotation direction and the second rotation direction (see FIGS. 3A to 3B). The control unit 20 is electrically connected to each of the recorder 13 and the jet head 14. Further, the control unit 20 can receive 3D-CAD data transmitted from the outside.

(6) Modeling with a 3D Printer Next, a modeling method with the 3D printer 1 will be described with reference to FIGS. 3A to 7B.

The modeling method in the 3D printer 1 includes a preparatory step of making the powder material in the container 15 substantially uniform (see FIGS. 3A to 3B) and a layer forming step of forming the powder material in layers (see FIGS. 4A and 4B). ), And a binder supply step (see FIGS. 5A and 5B) of supplying a binder to the layer of the powder material and solidifying the layer of the powder material. Then, at least the layer forming step and the binder supply step are repeated to manufacture the modeled object (see FIGS. 6A to 7B).

(6-1) Preparation Step As shown in FIG. 3A, in the preparation step, first, the powder material is supplied to the container 15 through the supply port 19. Then, after the powder material is supplied, the control unit 20 rotates the screw member 21 in the first rotation direction R1 so that the powder material becomes uniform inside the container 15, and then turns the screw member 21 into a first position. Rotate in the rotation direction R2 of 2.

Specifically, the control unit 20 rotates the screw member 21 in the first rotation direction R1 from the start of supply of the powder material until the first time T1 elapses. As a result, the screw member 21 conveys the powder material deposited below the supply port 19 toward the other side in the vertical direction.

The first time T1 is a time during which the screw member 21 rotating in the first rotation direction can convey the powder material located at one end in the vertical direction to the other end in the vertical direction inside the container 15. Is.

Next, as shown in FIG. 3B, after the lapse of the first time T1, the control unit 20 switches the rotation direction of the screw member 21 from the first rotation direction R1 to the second rotation direction R2. Then, the control unit 20 rotates the screw member 21 in the second rotation direction R2 from the switching of the rotation direction until the second time T2 elapses. As a result, the screw member 21 conveys the powder material accumulated at the other end in the vertical direction inside the container 15 toward one side in the vertical direction so as to be uniform.

The second time T2 is a time during which the screw member 21 rotating in the second rotation direction can uniformly convey the powder material accumulated at the other end in the vertical direction inside the container 15.

After that, the control unit 20 switches the rotation direction of the screw member 21 from the second rotation direction R2 to the first rotation direction R1 as necessary, and repeats the above operation.

As a result, as shown in FIG. 3C, the powder material becomes substantially uniform inside the container 15, and the preparation of the recoater 13 is completed.

(6-2) Layer Forming Step Next, as shown in FIGS. 4A and 4B, in the layer forming step, the control unit 20 laterally moves the recorder 13 for storing the powder material while slightly vibrating the blade 16. Move to. Then, the recorder 13 discharges the powder material from the discharge port 17 so as to be layered on the stage 12 (see FIG. 2). As a result, the first powder material layer 25 (powder material layer) is formed on the stage 12.

(6-3) Binder Supply Step Then, as shown in FIGS. 5A and 5B, in the binder supply step, the control unit 20 uses the jet head 14 to perform the first powder material based on the received 3D-CAD data. A binder is supplied to a portion of the layer 25 that becomes a modeled object. As a result, the first supply portion 26 to which the binder is supplied is formed on the first powder material layer 25. In the first supply portion 26, the supplied binders bond the powder materials to each other. As a result, the first supply portion 26 is solidified.

The control unit 20 can carry out the above-mentioned preparation step at the same time as the binder supply step. That is, while the jet head 14 supplies the binder to the first powder material layer 25, the powder material can be replenished to the container 15 and the powder material can be made substantially uniform inside the container 15.

(6-4) Repeating the layer forming step and the binder supply step Then, as shown in FIG. 6A, after the stage 12 is lowered by the thickness of the first powder material layer 25, the recoater 13 is subjected to the first powder material. The powder material is again discharged onto the layer 25 in a layered manner to form a second powder material layer 27 (powder material layer). After that, as shown in FIG. 6B, the jet head 14 supplies a binder to the portion of the second powder material layer 27 that becomes a sand mold to form the second supply portion 28.

Similarly, as shown in FIG. 7A, the layer formation of the powder material by the recoater 13 and the supply of the binder by the jet head 14 are sequentially repeated. When the layer formation of the powder material is repeated n times, the first powder material layer 25 to the nth powder material layer are sequentially laminated, and the first supply portion 26 to the nth supply portion are sequentially formed.

Then, as shown in FIG. 7B, the portion of the powder material layer to which the binder is not supplied is removed.

As described above, the modeled object 30 is manufactured. In FIG. 7A, for convenience, the surface of the modeled object 30 is shown to have a step, but in reality, the surface of the modeled object 30 is formed substantially smooth as shown in FIG. 7B. ..

(7) Action and Effect As shown in FIGS. 3A to 3C, in the 3D printer 1, the control unit 20 can switch the rotation direction of the screw member 21 between the first rotation direction R1 and the second rotation direction R2. To control. Therefore, the screw member 21 is rotated in the first rotation direction R1 to convey the powder material to the other side in the vertical direction, and then the rotation direction of the screw member 21 is switched to the second rotation direction R2 to obtain the powder. The material can be transported to one side in the vertical direction. Therefore, the powder material can be uniformly stored inside the container 15. Further, since the powder material circulates inside the container 15, it is possible to prevent the powder material from staying without being discharged for a long period of time. As a result, the recorder 13 can accurately form the powder material into layers, and the accuracy of the modeled object can be improved.

<Modification example>
In the above embodiment, the start timing of the first time T1 (that is, the start timing of the first rotation direction R1 of the screw member 21) is the same as the start of supply of the powder material to the container 15. The timing of the start of the first time T1 is not limited to this. For example, after the supply of the powder material to the container 15 is completed, the first time T1 may be started to rotate the screw member 21 in the first rotation direction R1.

In the above embodiment, after the lapse of the first time T1, the rotation direction of the screw member 21 is switched to the second rotation direction R2, but the timing of switching the rotation direction is not limited to this. For example, the rotation of the screw member 21 may be stopped for a predetermined time between the switching between the first rotation direction R1 and the second rotation direction R2. Specifically, after the first time T1 has elapsed, the rotation of the screw member 21 can be temporarily stopped, and then the screw member 21 can be rotated in the second rotation direction R2.

In the above embodiment, the control unit 20 controls switching of the rotation direction of the screw member 21 with reference to time, but the control of the control unit 20 is not limited to this. For example, the control unit 20 may control the switching of the rotation direction of the screw member 21 based on the detection result of the sensor.

In such a modification, the 3D printer 1 further includes a sensor 50, as shown by a virtual line in FIG. 3B. Further, the upper wall 15F of the container 15 has a sensor opening 51 for the sensor 50 to detect the powder material in the container 15. The sensor opening 51 is located at the other end of the upper wall 15F in the vertical direction.

Then, when the sensor 50 detects that the amount of the powder material accumulated in the other side portion in the vertical direction inside the container 15 exceeds a predetermined amount through the sensor opening 51, the control unit 20 causes the screw member 21. The rotation direction of is switched from the first rotation direction R1 to the second rotation direction R2. After the sensor 50 detects that there is a powder material in the other side portion in the vertical direction inside the container 15 through the sensor opening 51, the screw member 21 is rotated in the first rotation direction R1. It is also possible to maintain the screw member 21 for a predetermined time and then switch the rotation direction of the screw member 21 to the second rotation direction R2.

In the above embodiment, the 3D printer 1 is an inkjet type three-dimensional laminated molding apparatus that supplies a binder to a layer of a powder material and hardens the layer, but the three-dimensional laminated molding apparatus is not limited to this. The three-dimensional laminated molding apparatus may be a melting or sintering type three-dimensional laminated molding apparatus that hardens by melting or sintering a layer of a powder material. In this case, the three-dimensional laminated molding apparatus includes, instead of the jet head 14, a molten portion capable of melting the powder material or a sintered portion capable of sintering the powder material.

With these, the same action and effect as those of the above-described embodiment can be obtained. In addition, these embodiments and modifications can be combined appropriately.

1 3D printer 13 Recorder 15 Container 20 Control unit 21 Screw member R1 First rotation direction R2 Second rotation direction

Claims (1)

It is a three-dimensional laminated modeling device that repeatedly forms a layer of powder material and then solidifies the layer of powder material.
Is capable of storing the powder material, the recoater for discharging the powder material to be stored so that the layered,
A control unit that controls the operation of the recorder is provided.
The recorder is
A container capable of storing the powder material and
A screw member that is rotatable with respect to the container and that conveys the powder material in the container in the direction in which the rotation axis extends is provided.
The control unit is characterized in that it controls the rotation direction of the screw member so as to be switchable between a first rotation direction and a second rotation direction opposite to the first rotation direction. Former laminated molding equipment.

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