Three-dimensional shaping device and method of shaping

A three-dimensional shaping device comprises: a shaping vessel that has an outer peripheral wall and a shaping stand, the shaping stand configuring a bottom portion of the shaping vessel; a rotation mechanism that rotates the shaping stand; and a raising/lowering device that raises/lowers the shaping stand, wherein shaping is performed while the outer peripheral wall and the shaping stand are being rotated at the same angular speed by the rotation mechanism.

CROSS-REFERENCE TO RELATED APPLICATION

This application is based upon and claims the benefit of priority from Japanese Patent Application No. 2020-064309 filed on Mar. 31, 2020, the contents of which are incorporated herein by reference.

BACKGROUND OF THE INVENTION

Field of the Invention

The present invention relates to a three-dimensional shaping device and a method of shaping for forming a three-dimensional shaped object by jetting a binder onto a powder layer.

Description of the Related Art

In shaping of a three-dimensional shaped object, there have been proposed a variety of three-dimensional shaping devices that repeat an operation of hardening a necessary portion while overlaying powder in a layered manner. For example, there are the likes of a binder jetting system in which a binder is delivered from an ink jet head (Binder Jetting) and a powder bed fusion binding system in which the powder is solidified by being irradiated with the likes of a laser beam or electron beam (Powder bed fusion). The powder bed fusion binding system, which requires from several minutes to several tens of minutes for shaping of one layer, requires time for the shaping.

On the other hand, the binder jetting system, which is capable of high-speed processing due to there being no need for the powder to be melted, can perform shaping of one layer in a short time of the order of several seconds. With the advancements in ink jet technology of recent years, further improvements in shaping speed are expected.

Incidentally, a three-dimensional shaping device of the binder jetting system performs shaping while forming a powder layer of a shaping material inside a shaping vessel which is configured by a side wall and by a shaping stand that configures a bottom portion of the shaping vessel. However, in a conventional three-dimensional device, in which a step of forming the powder layer and a step of coating with the binder need to be alternately performed, an operation for forming the powder layer is intermittently performed, and a wasteful waiting time occurs. This results in a problem of the shaping speed slowing.

In order to solve such a problem, Japanese Patent No. 6266676 discloses a three-dimensional shaping device that rotates both a supply unit for supplying powder of the shaping material to a cylindrical shaping vessel and a coating unit for performing coating with the binder, and thereby performs formation of the powder layer and coating with the binder in a continuous operation.

SUMMARY OF THE INVENTION

In the three-dimensional shaping device of Japanese Patent No. 6266676, since it is difficult for a stable powder layer to be formed under conditions of a centrifugal force acting, the supply unit and the coating device are rotated at a constant speed with respect to the shaping vessel, without a shaping vessel side being rotated.

However, in the case of the supply unit and the coating device being rotated, it is required that the likes of piping for material supply and power supply wiring are provided in a rotating portion, and device configuration becomes complicated and hence large-scale. Moreover, there is a problem that, due to weight increase of the rotating portion, rotational speed of a shaping unit and the coating device cannot be increased, shaping speed slows, and shaping of mass-produced articles becomes difficult.

Moreover, if, in order to improve the rotational speed, configuring members of the supply unit and coating unit are downsized, then when a comparatively large shaped object is continuously shaped, replenishment of the shaping material and binder becomes necessary, and the device must be stopped midway, so production efficiency worsens.

Accordingly, an embodiment has an object of providing a three-dimensional shaping device and a method of shaping that, while simplifying a structure of a rotating portion, enable formation of a stable powder layer, and excel in shaping speed and production efficiency.

One aspect of the following disclosure is found in a three-dimensional shaping device comprising: a shaping vessel that has an outer peripheral wall and a shaping stand, the shaping stand configuring a bottom portion of the shaping vessel; a rotation mechanism that rotates the shaping stand; and a raising and lowering device that raises and lowers the shaping stand inside the outer peripheral wall, wherein the rotation mechanism rotates the shaping stand and the outer peripheral wall at a same angular speed.

Another aspect is found in a method of shaping employing a three-dimensional shaping device, the three-dimensional shaping device comprising: a shaping vessel that has an outer peripheral wall and a shaping stand, the shaping stand configuring a bottom portion of the shaping vessel; a rotation mechanism that rotates the shaping vessel; a raising and lowering device that raises and lowers the shaping stand with respect to the outer peripheral wall; a chute that is disposed above the shaping stand, and that delivers powder of a shaping material to the shaping vessel; a leveling plate that levels into a flat powder layer the powder that has been supplied from the chute; and a coating device that coats the powder layer with a binder, the method comprising: while continuously rotating the outer peripheral wall and the shaping stand at a same angular speed by the rotation mechanism, forming the powder layer with the chute and the leveling plate, coating the powder layer with the binder using the coating device, and every time the shaping vessel makes one rotation, lowering the shaping stand by the raising and lowering device for a new powder layer to be formed.

Due to the three-dimensional shaping device and the method of shaping of the above-described aspects, a stable powder layer can be formed, structure of a rotating portion is simplified, and shaping speed and production efficiency improve.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Preferred embodiments of a three-dimensional shaping device and a method of shaping will be presented and described in detail below with reference to the accompanying drawings.

First Embodiment

As shown inFIG.1, a three-dimensional shaping device10according to the present embodiment is a system that supplies a shaping material88(FIG.3) of a powder to a shaping vessel12, and coats the shaping material88with a binding agent (a binder) binding the shaping material88, thereby manufacturing a three-dimensional shaped object. Specifically, the three-dimensional shaping device10forms a powder layer80(FIG.2) of a certain thickness in an upper portion of the shaping vessel12, and coats this powder layer80with the binder to bind the powder, thereby forming a single shaped layer. The three-dimensional shaping device10repeats the above-described formation of the powder layer80and coating with the binder to laminate the shaped layers, and thereby form one shaped object.

Hereafter, an example where the three-dimensional shaping device10manufactures as the shaped object a sand mold (a core) for casting, will mainly be described. Note that the shaped object of the three-dimensional shaping device10is not limited to a mold for casting.

In the case of manufacturing a sand mold for casting, the likes of silica sand, alumina sand, zircon sand, chromite sand, olivine sand, and mullite sand, for example, may be cited as the shaping material88. Moreover, in addition to these, slag-based particles of the likes of ferrochrome-based slag, ferronickel-based slag, and converter slag can be employed. Moreover, in the case of shaping another shaped object, gypsum particles, starch particles, and particles of various kinds of resins, and so on, can be used.

The binder with which the shaping material88is to be coated is appropriately selected according to the shaping material88. To handle the above-described shaping material88employed in the mold for casting, there may be cited the likes of an organic material such as a phenol-based resin and a furan resin, and a water-soluble inorganic compound such as a clay, cement, and water glass, for example. The binder may include a catalyst promoting a hardening reaction of the shaping material88itself.

The three-dimensional shaping device10has: a base14; a plurality of frames16extending upwardly coupled to the base14; and a deck18that supports the shaping vessel12. A drive mechanism20for driving the shaping vessel12is provided between the base14and the deck18. The shaping vessel12is disposed on the deck18. Moreover, a supply device22for supplying the shaping material88, and a coating device24for coating with the binder, are provided above the shaping vessel12.

The supply device22comprises a hopper26, a circle feeder28, a connecting portion30, a chute32, and a leveling plate34. The hopper26, which is a funnel-shaped member provided in an upper end portion of the supply device22, houses on its inside the shaping material88configured by the powder. A bottom portion of the hopper26is provided with an opening, and the opening is connected with the circle feeder28. An inside of a cylindrically-shaped main body of the circle feeder28is provided with: an inner rotor formed with radially-extending blades; and an outer rotor comprising blades that circle an outer periphery of the inner rotor. By the inner rotor and the outer rotor of the circle feeder28rotating, the circle feeder28delivers at a desired flow rate to the connecting portion30the shaping material88flowing in from a lower portion of the hopper26.

The connecting portion30, which is a rectangular tube-like member connected between an outlet of the circle feeder28and the chute32, extends in a vertical direction. A lower end of the connecting portion30is connected with the chute32.

As shown inFIG.3, the chute32is a tube-like channel member having a discharge port32aformed in its lower end. A channel32cof rectangular shape elongated in a certain direction in planar view is formed inside the chute32. Note that althoughFIG.3shows a state where, for convenience of explanation, the chute32has been cut at its lower part, in reality, as shown inFIG.1, the connecting portion30is connected to an upper side of the chute32. The chute32is formed in a shape of a taper whose width (length in a short side direction) gradually narrows from an upper end side to a lower end side of the chute32. The shaping material88that has dropped down from the circle feeder28is stored to a certain height on a lower side of the chute32. The chute32has a powder sensor36installed on its side, and the shaping material88is supplied from the circle feeder28in such a manner that an upper end position of the stored shaping material88maintains a position of the powder sensor36.

The discharge port32ain a lower portion of the chute32is disposed facing a shaping surface12aappearing at an upper end of the shaping vessel12. A length in a longitudinal direction of the discharge port32ais formed smaller than a radius of the shaping vessel12. The discharge port32ais disposed with an orientation that its longitudinal direction is matched to a radial direction of the shaping vessel12. That is, the chute32supplies the shaping material88to a rectangular region lying along the radial direction.

The leveling plate34, which is a plate-like member disposed facing an inclined surface32bof the chute32, is fixed to the inclined surface32bby a method such as bolting, for example. The leveling plate34is disposed, at a certain interval, further on a downstream side in a rotating direction of the shaping vessel12than the chute32is. The leveling plate34is formed with the same length as the length in the longitudinal direction of the discharge port32a, and a lower end side34aof the leveling plate34flatly levels the powder of the shaping material88that has been discharged from the discharge port32aof the chute32of the shaping vessel12, and thereby forms the powder layer80.

On the other hand, the coating device24comprises: a coating head38of long length extending in the radial direction of the shaping vessel12; and a piping38athat supplies the coating head38with the binder, a drive current, and so on. The coating head38, which is provided with numerous nozzles on a surface thereof facing the shaping surface12aat the upper end of the shaping vessel12, discharges droplets of the binder from the nozzles toward the powder layer80. The coating head38is supplied with electric power and the binder via the piping38a. The coating device24, which is fixed to the frame16via a stay38b, is provided in a non-rotating portion.

Next, the shaping vessel12and its drive mechanism20will be described.

As shown inFIG.3, the shaping vessel12is disposed on the deck18. The shaping vessel12, which is a cylindrical vessel, is formed able to rotate around its axis. As shown inFIG.2, the shaping vessel12has: an outer peripheral wall40configuring a side portion of the shaping vessel12; and a shaping stand42configuring a bottom portion of the shaping vessel12. The outer peripheral wall40has at its upper end a flange portion40aextending out to an outer peripheral side, and, on its lower end side, comprises a bottom surface portion40bextending toward a center of the shaping vessel12, the bottom surface portion40bhaving formed on an inner peripheral side thereof a through-hole40c.

The bottom surface portion40bof the outer peripheral wall40abuts on a guiding member44. The guiding member44is disposed between the deck18and the bottom surface portion40b, and comprises a freely rotating roller44a. The guiding member44is configured in such a manner that by its roller44aabutting on the bottom surface portion40b, it guides rotation in a circumferential direction of the outer peripheral wall40, and prevents looseness (inclination) of the shaping vessel12.

The outer peripheral wall40has joined thereto at close to a center of its bottom surface portion40ban outer peripheral wall rotating shaft46. The outer peripheral wall40is supported in an axially rotatable manner by the outer peripheral wall rotating shaft46. Moreover, a shaping stand rotating shaft48of the shaping stand42is disposed in a penetrating manner in the through-hole40cof the outer peripheral wall40.

The shaping stand42, which is a plate-like member fitted to an inner side of the outer peripheral wall40, is formed in substantially the same shape as an inner peripheral surface40dof the outer peripheral wall40. The shaping stand42configures the bottom portion of the shaping vessel12. The shaping material88is supplied on top of the shaping stand42, and the powder layer80and shaped layers are progressively laminated on top of the shaping stand42. The shaping stand rotating shaft48is joined to the shaping stand42at a center of a lower end of the shaping stand42. The shaping stand42is supported in a rotatable manner by the shaping stand rotating shaft48.

The drive mechanism20comprises: the outer peripheral wall rotating shaft46; the shaping stand rotating shaft48; a rotation mechanism50; a synchronous rotation mechanism52that synchronizes rotation of the outer peripheral wall rotating shaft46and the shaping stand rotating shaft48; and a raising/lowering device54that raises/lowers the shaping stand42.

The outer peripheral wall rotating shaft46, which is joined to the bottom surface portion40bof the outer peripheral wall40, supports and axially rotates the outer peripheral wall40. The outer peripheral wall rotating shaft46, which is formed in a cylindrical shape extending cylindrically in an axial direction, has formed in its central portion a shaft hole46apenetrating in the axial direction. The shaft hole46ahas the shaping stand rotating shaft48inserted therein. A lower end portion46bof the outer peripheral wall rotating shaft46abuts on a supporting member56via a first bearing portion47. The supporting member56is fixed to the deck18and the frame16. The rotation mechanism50is provided at a side of the outer peripheral wall rotating shaft46.

The rotation mechanism50is configured by a motor, and has its drive shaft50aconnected to the outer peripheral wall rotating shaft46via a belt60. The belt60, which is bridged over the drive shaft50aand an outer peripheral portion of the outer peripheral wall rotating shaft46, transmits a driving force of the drive mechanism50to the outer peripheral wall rotating shaft46, and thereby rotates the outer peripheral wall rotating shaft46.

The shaping stand rotating shaft48, which is a circular column-like member extending in the axial direction, has its upper end connected to the shaping stand42, and has its lower end connected to the raising/lowering device54. The shaping stand rotating shaft48is connected to the raising/lowering device54via a second bearing portion58, and rotational movement of the shaping stand rotating shaft48is configured not to be transmitted to the raising/lowering device54.

The synchronous rotation mechanism52is provided to the shaft hole46abeing an abutting portion of the outer peripheral wall rotating shaft46and the shaping stand rotating shaft48. The synchronous rotation mechanism52comprises: a raising/lowering groove62provided in an outer peripheral portion of the shaping stand rotating shaft48; and a sliding projection64projecting inwardly from the outer peripheral wall rotating shaft46to be inserted in the raising/lowering groove62. One or a plurality of the raising/lowering grooves62, each of which is formed as a groove extending in the axial direction of the shaping stand rotating shaft48, are provided in the outer peripheral portion of the shaping stand rotating shaft48. In the example ofFIG.2, two raising/lowering grooves62are provided separated by 180° in a circumferential direction.

The sliding projection64, which is formed in a size enabling it to be inserted in the raising/lowering groove62, is configured capable of sliding in an axial direction along an inside of the raising/lowering groove62, along the raising/lowering groove62. The sliding projection64, which is formed integrally with the outer peripheral wall rotating shaft46, engages with the raising/lowering groove62to prevent relative rotation of the shaping stand rotating shaft48and the outer peripheral wall rotating shaft46.

The raising/lowering device54, which comprises: a motor54a; and a ball screw mechanism54bdriven by that motor54a, raises/lowers a shaft54c. The raising/lowering device54raises/lowers the shaping stand rotating shaft48through the shaft54c.

The three-dimensional shaping device10of the present embodiment, which is configured as above, will have its action described below along with the method of shaping.

The three-dimensional shaping device10shown inFIG.1performs a shaping operation, while rotating the shaping vessel12at a constant speed, by the drive mechanism20. As shown inFIG.2, the drive mechanism20applies a rotational force to the outer peripheral wall rotating shaft46through the rotation mechanism50. As a result, the outer peripheral wall40rotates integrally with the outer peripheral wall rotating shaft46. Moreover, rotational movement of the outer peripheral wall rotating shaft46is transmitted to the shaping stand rotating shaft48via the sliding projection64and the raising/lowering groove62configuring the synchronous rotation mechanism52. Thus, the shaping stand rotating shaft48rotates along with the outer peripheral wall rotating shaft46, and the shaping stand42supported by the shaping stand rotating shaft48rotates. As a result, the outer peripheral wall40and the shaping stand42rotate at the same angular speed.

After rotational speed of the shaping vessel12has settled at a constant speed, the supply device22starts to supply powder of the shaping material88. The shaping material88of the hopper26of the supply device22ofFIG.1is delivered to the connecting portion30through the circle feeder28. The shaping material88that has been delivered to the connecting portion30drops down toward the chute32. Then, while the shaping material88that has dropped down is stored in the chute32to the position of the powder sensor36, some of it is discharged from the discharge port32aat the lower end of the chute32.

As shown inFIG.3, the shaping material88that has been discharged from the chute32accumulates on top of the shaping stand42, and, with rotational movement of the shaping stand42, moves to a downstream side in the rotating direction. Then, the shaping material88is flatly leveled by the leveling plate34to form the flat powder layer80. The powder layer80passes below the coating device24, due to rotational movement of the shaping stand42. The coating device24discharges the binder at a certain position of the powder layer80, and thereby forms a desired shaped pattern (a slice or shaped layer).

Subsequently, the drive mechanism20performs a lowering operation displacing the shaping stand42downwards by a constant height, every time the shaping stand42makes one rotation. In the lowering operation of the shaping stand42, the raising/lowering device54ofFIG.2draws in the shaft54cdownwardly. Due to drawing-in of the shaft54c, the shaping stand rotating shaft48is displaced downwards via the second bearing portion58. At that time, the sliding projection64slides along the raising/lowering groove62, so displacement downwards of the shaping stand rotating shaft48is not prevented by the synchronous rotation mechanism52. The shaping stand42ascends/descends along with the shaping stand rotating shaft48.

Even during the lowering operation of the shaping stand42, the shaping stand42and the outer peripheral wall40continue their rotation at a constant speed. Moreover, supply of the shaping material88is performed at a constant flow rate from the chute32, and the powder layer80whose shaping has been completed has a new powder layer80formed on top thereof. Moreover, coating with the binder by the coating device24is simultaneously performed.

The three-dimensional shaping device10repeats formation of the powder layer80and shaping of the shaped layer while rotating the shaping vessel12at 20 to 60 rpm, for example. Since the shaping vessel12does not stop in an interval of the shaping operation, wasteful waiting time can be eliminated, and mass productivity is excellent.

As shown in a comparative example ofFIG.4A, when rotational speeds (angular speeds) of the shaping stand42and the outer peripheral wall40differ, the powder layer80formed on top of the shaping stand42is unstable due to receiving a resistance force from friction with the outer peripheral wall40, and has an unevenness81formed on its surface.

To counter this, in the three-dimensional shaping device10of the present embodiment, the shaping stand42and the outer peripheral wall40rotate at the same angular speed, hence the powder layer80on top of the shaping stand42can be formed flatly as shown inFIG.4B.

The three-dimensional shaping device10of the present embodiment displays the following advantages.

The three-dimensional shaping device10in the viewpoint described above comprises: the shaping vessel12having the outer peripheral wall40and the shaping stand42, the shaping stand42configuring the bottom portion of the shaping vessel12; the rotation mechanism50that rotates the shaping stand42; and the raising/lowering device54that raises/lowers the shaping stand42inside the outer peripheral wall40, wherein the outer peripheral wall40and the shaping stand42are connected via the synchronous rotation mechanism52that, while restricting relative movement in the circumferential direction with respect to each other of the outer peripheral wall40and the shaping stand42, enables their relative movement in the axial direction.

Due to the above-described configuration, in the shaping vessel12, the outer peripheral wall40and the shaping stand42are rotated at the same speed (angular speed), hence even when rotational speed of the shaping vessel12has been increased several tens of rpm, a stable powder layer80can be formed.

Moreover, it becomes possible for the supply device22and the coating device24to be provided in a non-rotating region, hence there is no need for the likes of piping for material supply or power supply wiring to be provided in a rotating region, and device configuration can be simplified. Since replenishment with the shaping material88of the supply device22and replenishment with the binder of the coating device24are easy, a large-sized shaped article too can be easily handled.

Furthermore, since the rotating portion is the shaping vessel12alone, the rotating portion is weight-lightened, hence improvement in rotational speed is easy, and suitable use is possible in mass-produced articles too.

In the above-described three-dimensional shaping device10, the synchronous rotation mechanism52may have: the raising/lowering groove62that is provided on either one of a shaping stand42and an outer peripheral wall40, and that extends in the axial direction; and the sliding projection64that is provided on the other of the shaping stand42and the outer peripheral wall40, and that, while engaging with the raising/lowering groove62to prevent relative rotation of the shaping stand42and the outer peripheral wall40, is capable of sliding in the axial direction along the raising/lowering groove62.

Due to the above-described configuration, the outer peripheral wall40and the shaping stand42can be rotated at the same speed by a simple device configuration. Moreover, the outer peripheral wall40and the shaping stand42can be rotated by a common rotation mechanism50.

In the above-described three-dimensional shaping device10, there may be provided: the shaping stand rotating shaft48that supports the shaping stand42; and the outer peripheral wall rotating shaft46that supports the outer peripheral wall40and has a shaft hole46athrough which the shaping stand rotating shaft48is inserted, wherein the raising/lowering groove62may be provided in the shaping stand rotating shaft48, and the sliding projection64may be provided in the outer peripheral wall rotating shaft46. Due to this configuration, the synchronous rotation mechanism52can be provided in a portion not sneaked into by powder of the shaping material88, hence reliability is excellent.

In the above-described three-dimensional shaping device10, the raising/lowering device54may be connected to the shaping stand rotating shaft48via the second bearing portion58. As a result, the raising/lowering device54can be provided in a non-rotating portion, hence device configuration can be simplified.

In the above-described three-dimensional shaping device10, the lower end of the outer peripheral wall40may be provided with the guiding member44that guides rotation of the outer peripheral wall40. Due to this configuration, inclination or looseness of the outer peripheral wall40are prevented, so that a stable powder layer80can be formed in the shaping vessel12.

The method of shaping of the present embodiment is a method of shaping employing the three-dimensional shaping device10, the three-dimensional shaping device10comprising: the shaping vessel12having the outer peripheral wall40and the shaping stand42, the shaping stand42configuring the bottom portion of the shaping vessel12; the rotation mechanism50that rotates the shaping vessel12; the raising/lowering device54that raises/lowers the shaping stand42with respect to the outer peripheral wall40; the chute32that is disposed above the shaping stand42, and that supplies powder of the shaping material88to the shaping vessel12; the leveling plate34that levels into a flat powder layer80the powder that has been supplied from the chute32; and the coating device24that coats the powder layer80with the binder, wherein, in the method, while the outer peripheral wall40and the shaping stand42are being continuously rotated at the same angular speed by the rotation mechanism50, the powder layer80is formed by the chute32and the leveling plate34, coating with the binder is performed by the coating device24, and, every time the shaping vessel12makes one rotation, the shaping stand42is lowered by the raising/lowering device54for a new powder layer80to be formed. Due to this method of shaping, shaping of the shaped object can be quickly performed.

Second Embodiment

As shown inFIG.5, a three-dimensional shaping device10A of the present embodiment differs from the three-dimensional shaping device10described with reference toFIGS.1to3regarding its drive mechanism20A. In the following, description will be made focusing on the drive mechanism20A, and descriptions of the supply device22and the coating device24will be omitted. Moreover, in the three-dimensional shaping device10A ofFIG.5, configurations the same as in the three-dimensional shaping device10ofFIG.2will be assigned with the same reference symbols as inFIG.2, and detailed descriptions thereof will be omitted.

The drive mechanism20A shown inFIG.5has a structure in which the shaping stand rotating shaft48supporting the shaping stand42has transmitted thereto rotational force of the rotation mechanism50. The shaping stand rotating shaft48has rotational force of the drive shaft50aof the rotation mechanism50transmitted thereto via the belt60. The shaping stand rotating shaft48is connected to the raising/lowering device54via the second bearing portion58.

In a shaping vessel12A, the bottom surface portion40bof an outer peripheral wall40A extends to an inner peripheral side to configure an outer peripheral wall rotating shaft46A that abuts on an outer peripheral surface of the shaping stand rotating shaft48. Moreover, a synchronous rotation mechanism52A of the present embodiment is provided in an abutting portion of the outer peripheral wall rotating shaft46A and the shaping stand rotating shaft48. The synchronous rotation mechanism52A comprises: a raising/lowering groove62A extending in the axial direction, provided in an outer periphery of the shaping stand rotating shaft48; and a sliding projection64A projecting from the outer peripheral wall rotating shaft46A. The sliding projection64A is inserted in the raising/lowering groove62A to prevent the outer peripheral wall40A and the shaping stand rotating shaft48from rotating relatively to each other. When a raising/lowering operation of the shaping stand rotating shaft48is performed, the sliding projection64A slides along the raising/lowering groove62A, and is thereby kept in a state of engagement with the raising/lowering groove62A.

As indicated above, the drive mechanism20A of the three-dimensional shaping device10A of the present embodiment has a configuration in which rotational force is transmitted to the shaping vessel12A via the shaping stand rotating shaft48. The three-dimensional shaping device10A of the present embodiment too enables similar advantages to those of the three-dimensional shaping device10of the first embodiment to be obtained.

Third Embodiment

As shown inFIG.6, a three-dimensional shaping device10B of the present embodiment differs from the three-dimensional shaping device10described with reference toFIGS.1to3regarding its drive mechanism20B. In the following, description will be made focusing on the drive mechanism20B, and descriptions of the supply device22and the coating device24will be omitted. Moreover, in the three-dimensional shaping device10B ofFIG.6, configurations the same as in the three-dimensional shaping device10ofFIG.2will be assigned with the same reference symbols as inFIG.2, and detailed descriptions thereof will be omitted.

In the drive mechanism20B shown inFIG.6, the shaping stand rotating shaft48supporting a shaping stand42B does not have the rotation mechanism50connected thereto, and a lower end of the shaping stand rotating shaft48is connected to the raising/lowering device54via the second bearing portion58.

On the other hand, an outer peripheral wall40B of a shaping vessel12B is supported by the guiding member44and a guiding member44B. The guiding member44B has connected thereto a rotation mechanism50B, and the rotation mechanism50B rotates the outer peripheral wall40B through the guiding member44B.

A synchronous rotation mechanism52B of the present embodiment is provided to the inner peripheral surface40dof the outer peripheral wall40B and to an outer peripheral portion of the shaping stand42B. That is, the synchronous rotation mechanism52B comprises: a raising/lowering groove62B extending in the axial direction, provided in the inner peripheral surface40d; and a sliding projection64B provided in the outer peripheral portion of the shaping stand42B. The sliding projection64B engages with the raising/lowering groove62B to rotate the shaping stand42B at the same speed as the outer peripheral wall40B. Moreover, by the sliding projection64B sliding in the axial direction along the raising/lowering groove62B, a raising/lowering operation of the shaping stand42B is enabled.

In the three-dimensional shaping device10B of the present embodiment configured as above, the synchronous rotation mechanism52B is provided to the inner peripheral surface40dof the outer peripheral wall40B and to the outer peripheral portion of the shaping stand42B. The three-dimensional shaping device10B of the present embodiment too enables similar advantages to those of the three-dimensional shaping device10of the first embodiment to be obtained.

Fourth Embodiment

As shown inFIG.7, in the three-dimensional shaping device10of the first embodiment, in the case of the powder layer80being formed while the shaping vessel12is being rotated at a constant rotational speed, it has become clear that, depending on conditions, an unevenness82like a surface of the powder layer80is undulating, will occur.

As shown inFIG.8, in the three-dimensional shaping device10of the first embodiment, a space between an outer peripheral end32eof the chute32and an outer peripheral end34eof the leveling plate34is open, and, at a time of formation of the powder layer80, the powder layer80is formed while some of the shaping material88that has been leveled off by the leveling plate34flows out to an outer peripheral side.

As a result of investigations having been performed by the inventors of the present application, it has become clear that if a distance h2(FIG.9A) between the discharge port32aof the chute32and the shaping surface12a, and a distance h1(FIG.9A) between the lower end side34aof the leveling plate34and the shaping surface12aare of the same height, then sometimes a supply deficiency of the shaping material88will occur, whereby an unleveled-off portion will occur. In addition, it has become clear that friction will occur between the shaping material88and the rotating flange portion40aof the outer peripheral wall40in a gap between the outer peripheral end32eof the chute32and the outer peripheral end34eof the leveling plate34, and that, as a result of this friction occurring, the laminated powder layer80will undulate.

Accordingly, in a three-dimensional shaping device10C of the present embodiment, as shown inFIG.9A, the distance h2between the shaping surface12aand the discharge port32aof the chute32is made larger than the distance h1between the lower end side34aof the leveling plate34and the shaping surface12a. Although not specifically limited, the distance h2can be set to about 3 mm, for example, and the distance h1can be set to about 1 mm, for example. As a result, an amount of the shaping material88discharged from the chute32increases, hence occurrence of the unevenness82due to supply deficiency of the shaping material88can be prevented.

Moreover, there is provided a blocking wall35that seals the gap between the outer peripheral end32eof the chute32and the outer peripheral end34eof the leveling plate34. As shown inFIG.9B, the blocking wall35is positioned above an end portion on an inner peripheral side of the flange portion40aof the outer peripheral wall40. By providing such a blocking wall35, the shaping material88between the chute32and the leveling plate34can be prevented from being discharged to the outer peripheral side, and frictional resistance between the shaping material88and the flange portion40acan be suppressed.

As indicated above, the three-dimensional shaping device10C of the present embodiment comprises: the shaping vessel12having the outer peripheral wall40and the shaping stand42, the shaping stand42configuring the bottom portion of the shaping vessel12; the rotation mechanism50(refer toFIG.2) that rotates the shaping stand42; the raising/lowering device54that raises/lowers the shaping stand42; the chute32that is disposed above the shaping stand42, and that delivers powder of the shaping material88to the shaping vessel12; and the leveling plate34that is provided on a downstream side in the rotating direction of the chute32, and that flatly levels the powder that has been delivered from the chute32, wherein the lower end side34aof the leveling plate34is disposed at a closer position to the shaping stand42than a lower end of the chute32is.

Due to the above-described configuration, the amount of the shaping material88discharged from the chute32increases, hence formation of the unevenness82due to a portion unleveled-off by the leveling plate34occurring as a result of supply deficiency of the shaping material88, can be prevented.

In the above-described three-dimensional shaping device10C, there may be provided the blocking wall35that blocks the gap between the outer peripheral end32eof the chute32and the outer peripheral end34eof the leveling plate34. Thus, the shaping material88between the chute32and the leveling plate34can be prevented from being discharged to the outer peripheral side, and frictional resistance between the shaping material88and the flange portion40acan be suppressed. As a result, occurrence of the unevenness82on the surface of the powder layer80can be prevented.

Fifth Embodiment

As shown inFIG.10A, in test example 1, evaluation of flatness of the powder layer80formed by the supply device22was performed. In test example 1, while the shaping vessel12was being rotated at a constant speed, the shaping material88was supplied from the chute32and flatly leveled by the leveling plate34to form the powder layer80. Arrangement of the leveling plate34and the chute32is assumed to be the same as inFIG.9A. Evaluation of flatness was performed by employing a height measuring device84to measure height of the powder layer80at a position of 70 mm from a rotational center and a position of 230 mm from the rotational center.

FIG.10Bshows measured results. InFIG.10B, time 0 min indicates a time when lowering of the shaping stand42of the shaping vessel12was stopped. R70 indicates change in height of the surface of the powder layer80at the position of 70 mm from the rotational center, and R230 indicates change in height of the surface of the powder layer80at the position of 230 mm from the rotational center. Although with passage of a certain time, the powder layer80settles at a constant height, there occurs a difference in height between the height (R70) of the powder layer80on an inner peripheral side and the height (R230) of the powder layer80on an outer peripheral side.

As shown inFIG.11A, in the chute32, in which the shaping material88is stored to the position of the powder sensor36, the shaping material88is discharged at a constant flow rate from the discharge port32a. When the shaping material88that has been discharged onto the shaping surface12ais leveled off by the leveling plate34, some of said shaping material88accumulates in the gap between the leveling plate34and the chute32. The shaping material88in a gap between the lower end side34aof the leveling plate34and the shaping surface12ais acted on by a pressure corresponding to height of the shaping material88that has accumulated in the gap between the leveling plate34and the chute32, and this pressure acts to increase an amount of the shaping material88passing through the gap between the leveling plate34and the shaping surface12a.

Meanwhile, in the gap between the lower end side34aof the leveling plate34and the shaping surface12a, as shown inFIG.11B, a speed gradient of the shaping material88occurs, and a pressure loss proportional to this speed gradient acts to negate the above-described pressure due to height of the shaping material88that has accumulated in the gap between the leveling plate34and the chute32.

As illustrated, linear speed of the shaping surface12ais larger on the outer peripheral side than on the inner peripheral side, hence the speed gradient dv/dh will be larger on the outer peripheral side (dv/dh(230)) than on the inner peripheral side (dv/dh(70)). As a result, the more the outer peripheral side is approached, the more difficult it becomes for the shaping material88to pass through the gap between the lower end side34aof the leveling plate34and the shaping surface12a. As a result, the more the outer peripheral side is approached, the lower the height of the powder layer80becomes.

Accordingly, in the present embodiment, as shown inFIG.12A, it has been decided to incline the lower end side34aof the leveling plate34in such a manner that the more the outer peripheral side is approached from the inner peripheral side, the more a separation distance from the shaping surface12aincreases. By configuring in this way, the more the outer peripheral side is approached, the more the gap between the lower end side34aof the leveling plate34and the shaping surface12aincreases. As a result, increase in the speed gradient dv/dh of the shaping material88in the gap between the lower end side34aof the leveling plate34and the shaping surface12acan be suppressed, and effects of pressure loss can be reduced. Moreover, expansion of a channel due to widening of the gap between the lower end side34aof the leveling plate34and the shaping surface12aresults in there also being obtained an advantage that passage flow rate of the shaping material88increases.

FIG.12Bshows measured results of test example 2 (the present embodiment) in which the leveling plate34that has had its lower end side34ainclined is employed. As illustrated, heights of the powder layer80are substantially the same on the inner peripheral side (R70) and the outer peripheral side (R230), and it can be confirmed that flatness of the powder layer80improves.

Sixth Embodiment

In the present embodiment, as shown inFIG.13, a surface of a shaping stand42C is configured by a friction surface42awhose friction with respect to the powder is high. The friction surface42acan be configured by the likes of a knurling-processed surface having fine grooves formed in a lattice shape therein, for example.

In the configuration for rotating the shaping vessel12, if the shaping stand42is configured by a smooth surface, then when supply of powder has begun to start, the powder will end up slipping on the surface of the shaping stand42, and time will end up being required until the powder stabilizes and the powder layer80is thereby formed.

In contrast, in the present embodiment, due to the surface of the shaping stand42C being configured by the friction surface42a, the shaping material88quickly establishes itself on the shaping stand42C, so that the powder layer80can be quickly formed, and a waiting time for a starting time of the three-dimensional shaping device10can be reduced.

Preferred embodiments of the present invention have been presented and described above. However, the present invention is not limited to the above-described embodiments, and it goes without saying that a variety of modifications thereof are possible in a range not departing from the spirit of the present invention.