THREE-DIMENSIONAL LAMINATING AND SHAPING APPARATUS, CONTROL METHOD OF THREE-DIMENSIONAL LAMINATING AND SHAPING APPARATUS, AND CONTROL PROGRAM OF THREE-DIMENSIONAL LAMINATING AND SHAPING APPARATUS

The shaping precision is improved without performing finishing processing. A three-dimensional laminating and shaping apparatus includes a material ejector that ejects a material of a three-dimensional laminated and shaped object onto a shaping table on which the three-dimensional laminated and shaped object is shaped, a light beam irradiator that irradiates the ejected material with a light beam, a cutter that cuts a bead formed when the material irradiated with the light beam is melted and solidified, and a controller that controls ejection of the material by the material ejector, irradiation with the light beam by the light beam irradiator, and cutting of the bead by the cutter. The cutter cuts an upper surface of the bead by a dimension which is smaller than a laminating height and is ½ or less of a bead thickness.

TECHNICAL FIELD

The present invention relates to a three-dimensional laminating and shaping apparatus, a control method of the three-dimensional laminating and shaping apparatus, and a control program of the three-dimensional laminating and shaping apparatus.

BACKGROUND ART

In the above technical field, patent literature 1 discloses a technique of removing the outer layer and unnecessary portion of a shaped object during formation of the shaped object in a powder bed type three-dimensional laminating and shaping apparatus.

CITATION LIST

Patent Literature

SUMMARY OF THE INVENTION

Technical Problem

In the technique described in the above literature, however, cutting of the side surface of a shaped object is complicated depending on the shape of the shaped object, thereby requiring a long time.

The present invention enables to provide a technique of solving the above-described problem.

Solution to Problem

One aspect of the present invention provides a three-dimensional laminating and shaping apparatus comprising:a material ejector that ejects a material of a three-dimensional laminated and shaped object onto a shaping table on which the three-dimensional laminated and shaped object is shaped;a light beam irradiator that irradiates the ejected material with a light beam; anda cutter that cuts a bead formed when the material irradiated with the light beam is melted and solidified,wherein the cutter cuts an upper surface of the bead at least once during a plurality of shaping steps by the material ejector and the light beam irradiator.

Another aspect of the present invention provides a control method of a three-dimensional laminating and shaping apparatus, comprising:ejecting a material of a three-dimensional laminated and shaped object onto a shaping table on which the three-dimensional laminated and shaped object is shaped;irradiating the ejected material with a light beam; andcutting a bead formed when the material irradiated with the light beam is melted and solidified,wherein in the cutting, an upper surface of the bead is cut at least once during a plurality of shaping steps in the ejecting and the irradiating.

Still other aspect of the present invention provides a control program of a three-dimensional laminating and shaping apparatus, for causing a computer to execute a method, comprising:ejecting a material of a three-dimensional laminated and shaped object onto a shaping table on which the three-dimensional laminated and shaped object is shaped;irradiating the ejected material with a light beam; andcutting a bead formed when the material irradiated with the light beam is melted and solidified,wherein in the cutting, an upper surface of the bead is cut at least once during a plurality of shaping steps in the ejecting and the irradiating.

Advantageous Effects of Invention

According to the present invention, it is possible to improve the shaping precision without performing finishing processing.

DESCRIPTION OF THE EMBODIMENTS

First Embodiment

A three-dimensional laminating and shaping apparatus100according to the first embodiment of the present invention will be described with reference toFIG. 1. The three-dimensional laminating and shaping apparatus100is an apparatus for shaping a three-dimensional laminated and shaped object by ejecting a material130onto a shaping table120, and irradiating the ejected material130with a light beam140. As shown inFIG. 1, the three-dimensional laminating and shaping apparatus100includes a material ejector101, a light beam irradiator102, a cutter103, and a controller104.

The material ejector101ejects the material130of a three-dimensional laminated and shaped object150onto the shaping table120on which the three-dimensional laminated and shaped object150is shaped. The light beam irradiator102irradiates the material130with the light beam140. The cutter103cuts a bead160formed when the material130irradiated with the light beam140is melted and solidified. The cutter103cuts the upper surface of the bead by a dimension which is smaller than a laminating height and is ½ or less of a bead thickness. The controller104controls ejection of the material130by the material ejector101, irradiation with the light beam140by the light beam irradiator102, and cutting of the bead160by the cutter103.

According to this embodiment, it is possible to reduce the surface roughness of the shaped object while performing high-precision and high-efficiency laminating and shaping.

Second Embodiment

A three-dimensional laminating and shaping apparatus according to the second embodiment of the present invention will be described with reference toFIGS. 2 to 9. Note that an LMD (Laser Metal Deposition) type three-dimensional laminating and shaping apparatus will be exemplified as a three-dimensional laminating and shaping apparatus200. The three-dimensional laminating and shaping apparatus200can adjust the width and height of a bead260by controlling the output of the light beam240and the ejection amount of a material230, thereby shaping a three-dimensional laminated and shaped object250using a high-efficiency shaping and high-precision shaping. High-efficiency shaping indicates shaping of the three-dimensional laminated and shaped object250by forming the bead260having relatively large width and height. High-precision shaping indicates shaping of the three-dimensional laminated and shaped object250by forming the bead260having relatively small width and height.

FIG. 2is a view for explaining the arrangement of the three-dimensional laminating and shaping apparatus according to this embodiment. The three-dimensional laminating and shaping apparatus200includes a material ejector201, a light beam irradiator202, a cutter203, a controller204, and an inclination unit205.

The material ejector201ejects the material230such as a metal powder onto a shaping table220. The three-dimensional laminated and shaped object250is shaped on the shaping table220. The material230is not limited to the metal powder, and may be, for example, a resin powder or the like.

The light beam irradiator202irradiates, from the distal end portion of the material ejector201, the material230with the light beam240such as a laser beam or electron beam emitted from the light beam irradiator202. Note that the light beam240is not limited to the laser beam or electron beam, and may be a light beam of another wavelength. The material230irradiated with the light beam240such as a laser beam is melted by heat (energy) applied from the light beam240, thereby forming a molten pool. After that, the molten pool is cooled and solidified, thereby forming the bead260. The material230is laminated by repeating ejection of the material230and irradiation with the light beam240, thus forming the three-dimensional laminated and shaped object250.

The cutter203cuts the surface of the bead260formed when the material230is melted by heat applied by the light beam240and solidified. The bead260formed when the material230is melted and solidified has an elliptic sectional shape. The cutter203cuts the surface of the bead260, for example, the upper surface or side surface so that the surface (upper surface or side surface) of the bead260is horizontal to the shaping surface of the shaping table220or perpendicular to a laminating direction. As the cutting amount of the upper surface of the bead260by the cutter203, the cutter203preferably cuts the upper surface by a dimension which is smaller than a laminating height and is ½ or less of the thickness of the bead260. The present invention, however, is not limited to this, and the cutter203may cut the upper surface by an arbitrary amount, as needed.

At the time of cutting of the bead260, the three-dimensional laminating and shaping apparatus200moves the shaping table220so that the bead260is positioned below the cutter203. To the contrary, the three-dimensional laminating and shaping apparatus200may move the cutter203so that the bead260is positioned below the cutter203. Note that the cutter203is, for example, a cutting tool such as an end mill. The present invention, however, is not limited to this, and any tool capable of cutting the surface of the bead260may be used.

The controller204controls ejection of the material230, irradiation with the light beam240, and cutting of the bead260. Upon, for example, completion of laminating of one layer by ejecting the material230by the material ejector201and irradiating the material230with the light beam240by the light beam irradiator202, the controller204may execute cutting by the cutter203. Alternatively, upon completion of laminating of a plurality of layers (n layers), the controller204may execute cutting by the cutter203. The controller204decides the cutting amount of the bead260based on the shaping precision required by the three-dimensional laminated and shaped object250to be shaped.

The inclination unit205inclines the shaping table220. For example, if the material230having a high reflectance for the light beam240is used as the material230of the three-dimensional laminated and shaped object250, the light beam240with which the material230is irradiated is reflected. The reflected light damages a condenser lens (not shown) included in the material ejector201, an oscillator (not shown) for the light beam240, or the like. To cope with this, the inclination unit205inclines the shaping table220so the reflected light does not enter the material ejector201, thereby preventing the reflected light from entering the material ejector201. If the three-dimensional laminated and shaped object250having a complicated shape is shaped, the shaping table220is inclined.

FIG. 3is a view showing the shape of the bead260formed by the three-dimensional laminating and shaping apparatus200. The bead260has an elliptic shape when viewed sideways. The major axis of the ellipse corresponds to a laminating width, the minor axis of the ellipse corresponds to the bead thickness, and a portion extending from the upper surface of the shaping table220corresponds to the laminating height. The three-dimensional laminating and shaping apparatus200shapes the three-dimensional laminated and shaped object by laminating a plurality of beads260.

FIG. 4is a view for explaining an example of shaping of the three-dimensional laminated and shaped object250by the three-dimensional laminating and shaping apparatus200according to this embodiment. After the bead260of one layer is shaped (401inFIG. 4), the three-dimensional laminating and shaping apparatus200cuts, using the cutter203, the upper surface of the bead260by a predetermined amount (402inFIG. 4). This predetermined amount is, for example, ½ or more of the laminating height but the present invention is not limited to this. As described above, by cutting the upper surface by ½ or more of the laminating height, it is possible to cut a curve portion261of the ellipse, and leave a portion262approximate to a straight line of the ellipse. The bead260with the thus cut upper surface has an almost vertical side surface.

The three-dimensional laminating and shaping apparatus200shapes a new bead260of one layer on the bead260which has been cut and has the almost vertical side surface (403inFIG. 4), and then cuts the upper surface of the newly formed bead260by the cutter203(404inFIG. 4). The three-dimensional laminating and shaping apparatus200shapes a next bead260(405inFIG. 4). By repeating these steps, the three-dimensional laminating and shaping apparatus200can laminate the plurality of beads260each having an almost vertical side surface, and shape the three-dimensional laminated and shaped object250having high side surface accuracy. The surface roughness of the side surface of the three-dimensional laminated and shaped object250obtained by performing cutting by the three-dimensional laminating and shaping apparatus200is about 1/10 of that of a three-dimensional laminated and shaped object obtained without performing cutting.

Note that an example in which cutting is performed for every layer has been explained as a cutting timing. The cutting timing is not limited to this. For example, cutting may be performed for every predetermined number of layers (n layers).

FIG. 5is a view showing the three-dimensional laminated and shaped object shaped without performing cutting by the three-dimensional laminating and shaping apparatus200and the three-dimensional laminated and shaped object shaped by performing cutting by the three-dimensional laminating and shaping apparatus200according to this embodiment. The three-dimensional laminated and shaped object shaped without performing cutting by the three-dimensional laminating and shaping apparatus200is shaped by laminating the beads260each having the elliptic sectional shape, and thus the shaping roughness of the side surface is large (501inFIG. 5).

To the contrary, since the three-dimensional laminated and shaped object shaped by performing cutting by the three-dimensional laminating and shaping apparatus200is shaped by laminating the beads260each having the almost vertical side surface, the roughness of the side surface of the shaped object is small (502inFIG. 5).

FIGS. 6A to 6Care views for explaining a problem in another example of shaping of the three-dimensional laminated and shaped object250by the three-dimensional laminating and shaping apparatus200according to this embodiment. If the material230of the three-dimensional laminated and shaped object250is the material230having a high reflectance for the light beam240, such as copper (Cu), aluminium (Al), or iron (Fe), it is necessary to perform laminating and shaping by inclining the shaping table220, as shown inFIG. 6A.

This is because if the material230having a high reflectance for the light beam240is used, light610reflected from a molten pool620formed when the material230is melted by heat of the light beam240enters the material ejector201, and damages the light beam oscillator for the light beam240, the condenser lens for the light beam240, or the like.

However, if, as shown inFIG. 6A, the shaping table220is inclined, a locally deformed bead260is formed, as shown inFIG. 6B. Then, if, as shown inFIG. 6C, shaping is continued while the bead260is locally deformed, the local deformation is accumulated, thereby forming the three-dimensional laminated and shaped object250having a large shaping error.

FIG. 7is a view for explaining the other example of shaping of the three-dimensional laminated and shaped object250by the three-dimensional laminating and shaping apparatus200according to this embodiment. Referring toFIG. 7, the shaping table220is horizontally drawn on a sheet but is actually inclined.

As shown in701ofFIG. 7, if shaping is executed by inclining the shaping table220and irradiating the material230with the light beam240, the formed bead260is locally deformed. As shown in702ofFIG. 7, for example, after completion of laminating of the material230of one layer, the formed bead260is cut using the cutter203. As shown in703ofFIG. 7, the next material230is laminated on the cut bead260. By repeating the above procedure, it is possible to shape the three-dimensional laminated and shaped object250with high precision and high efficiency even if the shaping table220is inclined. Note that an example in which the shaping table220is inclined has been explained. However, the material ejector201and the cutter203may be inclined while maintaining the shaping table220in a horizontal position. After shaping, the inclination of the shaping table220may be adjusted to position the cutter203and the shaping table to be almost perpendicular to each other, thereby cutting the formed bead260.

FIG. 8Ais a view showing an example of the three-dimensional laminated and shaped object250having a structure advantageous in shaping by the three-dimensional laminating and shaping apparatus200according to this embodiment.FIG. 8Bis a view showing another example of the three-dimensional laminated and shaped object250having a structure advantageous in shaping by the three-dimensional laminating and shaping apparatus200according to this embodiment. As shown inFIG. 8A or 8B, if the three-dimensional laminated and shaped object250has a closed structure (hollow structure) including a space, even if an attempt is made to cut portions indicated by arrows801or802after completion of cutting, the cutting tool cannot reach them and it is thus difficult to cut them. To cope with this, if the three-dimensional laminating and shaping apparatus200according to this embodiment shapes such the three-dimensional laminated and shaped object250, the high-precision three-dimensional laminated and shaped object250can be obtained within a short time upon completion of shaping. All the beads260formed by the material ejector201can be processed by the cutter203. Therefore, the three-dimensional laminated and shaped object250having the structure advantageous in shaping by the three-dimensional laminating and shaping apparatus200according to this embodiment is not limited to those shown inFIGS. 8A and 8B. For example, the three-dimensional laminated and shaped object250having a more complicated structure or a simple structure may be used.

FIG. 9is a flowchart for explaining the processing procedure of the three-dimensional laminating and shaping apparatus200according to this embodiment. In step S901, the three-dimensional laminating and shaping apparatus200acquires the shaping model of the three-dimensional laminated and shaped object250, and acquires, based on the acquired shaping model, shaping data such as the kind of material230and the intensity of the light beam240with which irradiation is performed.

In step S903, the three-dimensional laminating and shaping apparatus200determines based on the acquired shaping data whether it is necessary to incline the shaping table220. The three-dimensional laminating and shaping apparatus200determines, from the acquired shaping data, the necessity to incline the shaping table220based on, for example, whether the material230has a high reflectance. If it is necessary to incline the shaping table220, the three-dimensional laminating and shaping apparatus200advances to step S905. In step S905, the three-dimensional laminating and shaping apparatus200inclines the shaping table220by a predetermined angle. If it is not necessary to incline the shaping table220, the three-dimensional laminating and shaping apparatus200advances to step S907.

In step S907, the three-dimensional laminating and shaping apparatus200performs laminating and shaping for one layer. In step S909, the three-dimensional laminating and shaping apparatus200cuts the surface, for example, the upper surface of the formed bead260by a predetermined amount.

In step S911, the three-dimensional laminating and shaping apparatus200determines whether laminating and shaping of the three-dimensional laminated and shaped object250have ended. If laminating and shaping have ended, the three-dimensional laminating and shaping apparatus200terminates the processing; otherwise, the three-dimensional laminating and shaping apparatus200repeats step S907and the subsequent steps.

According to this embodiment, it is possible to shorten the shaping time while shaping a high-precision three-dimensional laminated and shaped object. If a three-dimensional laminated and shaped object obtained by joining a plurality of materials having a weak joining strength is laminated and shaped by providing an intermediate layer, it is possible to obtain a dissimilar material-joined three-dimensional laminated and shaped object while decreasing the thickness of the intermediate layer. Furthermore, if a three-dimensional laminated and shaped object is shaped using a material having a high light beam reflectance, even if the shaping table is inclined, a bead having small local deformation can be formed, thereby obtaining a three-dimensional laminated and shaped object with high shaping precision.

Other Embodiments

The present invention is applicable to a system including a plurality of devices or a single apparatus. The present invention is also applicable even when an information processing program for implementing the functions of the embodiments is supplied to the system or apparatus directly or from a remote site. Hence, the present invention also incorporates the program installed in a computer to implement the functions of the present invention by the computer, a medium storing the program, and a WWW (World Wide Web) server that causes a user to download the program. Especially, the present invention incorporates at least a non-transitory computer readable medium storing a program that causes a computer to execute processing steps included in the above-described embodiments.