Patent Publication Number: US-2019168460-A1

Title: Three-dimensional shaping apparatus, control method of three-dimensional shaping apparatus, and control program of three-dimensional shaping apparatus

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application is based upon and claims the benefit of priority from Japanese patent application No. 2017-232906, filed on Dec. 4, 2017, the disclosure of which is incorporated herein in its entirety by reference. 
     BACKGROUND OF THE INVENTION 
     Field of the Invention 
     The present invention relates to a three-dimensional shaping apparatus, a control method of the three-dimensional shaping apparatus, and a control program of the three-dimensional shaping apparatus. 
     Description of the Related Art 
     In the above technical field, patent literature 1 discloses a technique of blocking the lower end of the vertical moving path of a stage by providing, on the inner circumferential surface of a frame portion, a contact portion protruding inward. 
     [Patent Literature 1] Japanese Patent Laid-Open No. 2013-75389 
     SUMMARY OF THE INVENTION 
     In the technique described in the above literature, however, it is impossible to position a platform accurately. 
     The present invention enables to provide a technique of solving the above-described problem. 
     One example aspect of the present invention provides a three-dimensional shaping apparatus for shaping a three-dimensional shaped object, comprising: 
     a material storage that stores a material of the three-dimensional shaped object; 
     a platform arranged facing the material storage; 
     a moving unit that moves the platform in a vertical direction; 
     a shaping pad that is provided on a surface, facing the material storage, of the platform, so that the three-dimensional shaped object is shaped; 
     a first detector that detects downward movement of the material storage; and 
     a movement controller that controls, if the downward movement of the material storage is detected, the movement of the platform by the moving unit. 
     Another example aspect of the present invention provides a control method of a three-dimensional shaping apparatus for shaping a three-dimensional shaped object, including 
     a material storage that stores a material of the three-dimensional shaped object, 
     a platform arranged facing the material storage, 
     a moving unit that moves the platform in a vertical direction, 
     a shaping pad that is provided on a surface, facing the material storage, of the platform, so that the three-dimensional shaped object is shaped, 
     a first detector that detects downward movement of the material storage, and 
     a movement controller that controls, if the downward movement of the material storage is detected, the movement of the platform by the moving unit, 
     the method comprising: 
     causing the moving unit to move the platform in the vertical direction; 
     detecting the downward movement of the material storage; and 
     controlling, if the downward movement of the material storage is detected, the movement of the platform by the moving unit. 
     Still other example aspect of the present invention provides a control program of a three-dimensional shaping apparatus for shaping a three-dimensional shaped object, including 
     a material storage that stores a material of the three-dimensional shaped object, 
     a platform arranged facing the material storage, 
     a moving unit that moves the platform in a vertical direction, 
     a shaping pad that is provided on a surface, facing the material storage, of the platform, so that the three-dimensional shaped object is shaped, 
     a first detector that detects downward movement of the material storage, and 
     a movement controller that controls, if the downward movement of the material storage is detected, the movement of the platform by the moving unit, 
     the program for causing a computer to execute a method, comprising: 
     causing the moving unit to move the platform in the vertical direction; 
     detecting the downward movement of the material storage; and 
     controlling, if the downward movement of the material storage is detected, the movement of the platform by the moving unit. 
     According to the present invention, it is possible to position a platform accurately. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a view showing the arrangement of a three-dimensional shaping apparatus according to the first example embodiment of the present invention; 
         FIG. 2A  is a perspective view showing an outline of the arrangement of a three-dimensional shaping apparatus according to the second example embodiment of the present invention; 
         FIG. 2B  is a plan view showing the arrangement of the three-dimensional shaping apparatus according to the second example embodiment of the present invention; 
         FIG. 2C  is a schematic side view showing the arrangement of the three-dimensional shaping apparatus according to the second example embodiment of the present invention; 
         FIG. 2D  is a schematic front view for explaining an outline of the operation of the three-dimensional shaping apparatus according to the second example embodiment of the present invention; 
         FIG. 3A  is a view for explaining alignment of a platform by the three-dimensional shaping apparatus according to the second example embodiment of the present invention; 
         FIG. 3B  is a view for explaining the alignment of the platform by the three-dimensional shaping apparatus according to the second example embodiment of the present invention; 
         FIG. 3C  is a view for explaining the alignment of the platform by the three-dimensional shaping apparatus according to the second example embodiment of the present invention; 
         FIG. 3D  is a view for explaining the alignment of the platform by the three-dimensional shaping apparatus according to the second example embodiment of the present invention; 
         FIG. 3E  is a view for explaining the alignment of the platform by the three-dimensional shaping apparatus according to the second example embodiment of the present invention; 
         FIG. 3F  is a view for explaining the alignment of the platform by the three-dimensional shaping apparatus according to the second example embodiment of the present invention; 
         FIG. 3G  is a view for explaining the alignment of the platform by the three-dimensional shaping apparatus according to the second example embodiment of the present invention; 
         FIG. 3H  is a view for explaining the alignment of the platform by the three-dimensional shaping apparatus according to the second example embodiment of the present invention; 
         FIG. 3I  is a view for explaining the alignment of the platform by the three-dimensional shaping apparatus according to the second example embodiment of the present invention; 
         FIG. 3J  is a view for explaining the alignment of the platform by the three-dimensional shaping apparatus according to the second example embodiment of the present invention; 
         FIG. 4  is a view showing an outline of the arrangement of a three-dimensional shaping apparatus according to third example embodiment of the present invention; and 
         FIG. 5  is a flowchart for explaining the operation procedure of the three-dimensional shaping apparatus according to third example embodiment of the present invention. 
     
    
    
     DESCRIPTION OF THE EXAMPLE EMBODIMENTS 
     Example embodiments of the present invention will now be described in detail with reference to the drawings. It should be noted that the relative arrangement of the components, the numerical expressions and numerical values set forth in these example embodiments do not limit the scope of the present invention unless it is specifically stated otherwise. 
     First Example Embodiment 
     A three-dimensional shaping apparatus  100  according to the first example embodiment of the present invention will be described with reference to  FIG. 1 . The three-dimensional shaping apparatus  100  is an apparatus that shapes a three-dimensional shaped object by irradiating a material of the three-dimensional shaped object with a light beam. 
     As shown in  FIG. 1 , the three-dimensional shaping apparatus  100  includes a material storage  101 , a platform  102 , a moving unit  103 , a shaping pad  104 , a first detector  105 , and a movement controller  106 . 
     The material storage  101  stores a material  111  of a three-dimensional shaped object. The platform  102  is arranged facing the material storage  101 . The moving unit  103  moves the platform  102  in the vertical direction. The shaping pad  104  is provided on a surface, facing the material storage  101 , of the platform  102 , so that the three-dimensional shaped object is shaped. The first detector  105  detects downward movement of the material storage  101 . If downward movement of the material storage  101  is detected, the movement controller  106  controls the movement of the platform  102  by the moving unit  103 . 
     According to this example embodiment, it is possible to position the platform accurately. 
     Second Example Embodiment 
     A three-dimensional shaping apparatus according to the second example embodiment of the present invention will be described with reference to  FIGS. 2A to 3J . 
       FIG. 2A  is a perspective view showing an outline of the arrangement of the three-dimensional shaping apparatus according to this example embodiment.  FIG. 2B  is a plan view showing the arrangement of the three-dimensional shaping apparatus according to this example embodiment.  FIG. 2C  is a schematic side view showing the arrangement of the three-dimensional shaping apparatus according to this example embodiment. 
     A three-dimensional shaping apparatus  200  includes a light source  201 , a column  202 , a table  203 , a material storage  204 , a platform  205 , a stepping motor  206 , a proximity sensor  207 , and a supporter  208 . 
     The light source  201  emits a light beam  211  with which a material  241  of a three-dimensional shaped object is irradiated. The material  241  is, for example, a photo-curing resin. The light beam  211  with which the material  241  is irradiated may be any light beam  211  as long as it has a wavelength that can cure the material  241  of the three-dimensional shaped object. The light beam  211  has, for example, a wavelength of 405 nm but may have a wavelength of 200 nm to 400 nm. The present invention is not limited to this. 
     The table  203  is attached to the column  202 . A photosensor  231  is attached to the table  203  via a sensor supporter (sensor bracket)  232 . The position of the photosensor  231  is adjusted using a sensor adjustment stage  233 . 
     The material storage (vat)  204  is placed on the table  203 . The material  241  of the three-dimensional shaped object is charged and stored in the material storage  204 . A bottom surface  242  of the material storage  204  is formed by including a member capable of transmitting the light beam  211 . The member capable of transmitting the light beam  211  is represented by, for example, a glass member but the present invention is not limited to this. The entire material storage  204  may be formed by a member capable of transmitting the light beam  211 . Note that the material storage  204  may be fixed to a predetermined position on the table  203  by a screw or the like, or may simply be placed on the table  203 . A method of placing the material storage  204  on the table  203  is not limited to them. 
     The platform  205  is attached to a platform support member  251  by a platform mounting screw  253 . In addition, the platform  205  is attached to the column  202  via the platform support member  251 . The platform  205  can be detached from the platform support member  251  by loosening the platform mounting screw  253 . The platform  205  can be fixed to the platform support member  251  by tightening the platform mounting screw  253 . 
     The platform  205  is arranged facing the material storage  204 . A shaping pad  252  on which a three-dimensional shaped object is shaped is provided on a surface, facing the material storage  204 , of the platform  205 . A three-dimensional shaped object is shaped on the shaping pad  252 . 
     A linear actuator  221  and the stepping motor  206  are provided in the column  202 . The platform  205  can be moved in the vertical direction by a moving unit including the platform support member  251 , the linear actuator  221 , and the stepping motor  206 . The position of the platform  205  can be detected using a contact bracket  222  and the photosensor  231 . 
     The proximity sensor  207  is arranged on the table  203 . The proximity sensor  207  is arranged between the material storage  204  and the column  202 . Then, the proximity sensor  207  detects movement of the material storage  204  in a direction (downward direction) in which the material storage  204  approaches the table  203 . Note that the arrangement position of the proximity sensor  207  is not limited to the above-described one, and may be any position at which the movement of the material storage  204  can be detected. 
     Instead of detecting the downward movement of the material storage  204  using the proximity sensor  207 , the downward movement of the material storage  204  may be detected using a mechanical switch or the like. 
     The supporter  208  supports the material storage  204  from the side of the bottom surface  242  of the material storage  204 . The supporter  208  is arranged between the table  203  and the material storage  204 . The material storage  204  floats from the table  203  by the supporter  208 . In this example, the supporter  208  is a member such as a spring that is deflected when applied with a load. The supporter  208  is a member that has a strength enough to reliably support the material storage  204  not to move its position in a normal state but is deflected when a load is applied to the material storage  204 . Note that one or a plurality of supporters  208  may be provided on the side of the table  203  of the bottom surface  242  of the material storage  204 . A position at which the supporter  208  is arranged is not limited, and may be, for example, a position at which the light beam  211  from the light source  201  is not blocked. Furthermore, the supporter  208  is made of, for example, a material capable of transmitting the light beam  211 . 
     If the downward movement of the material storage  204  is detected, a movement controller  209  controls the movement of the platform  205  by the moving unit in correspondence with the position of the platform  205 . If the downward movement of the material storage  204  is detected, for example, the movement controller  209  stops the movement of the platform  205 . Since this stops the movement of the platform  205 , the material storage  204  does not lower downward, and thus no excessive load is applied to the bottom surface  242 , thereby making it possible to prevent damage to the bottom surface  242 . 
       FIG. 2D  is a schematic front view for explaining an outline of the operation of the three-dimensional shaping apparatus according to this example embodiment. As shown in  FIG. 2D , the material storage  204  is supported by the supporter  208  to float from the table  203 . If the material storage  204  is pressed by the platform  205  or the like to move (lower) downward (in the direction of an arrow in  FIG. 2D ), the proximity sensor  207  detects the downward movement of the material storage  204 . Then, if the downward movement of the material storage  204  is detected, the movement controller  209  stops the movement of the platform  205 . 
     When shaping a three-dimensional shaped object, the platform  205  is moved downward and positioned so that the shaping pad  252  contacts the bottom surface  242  of the material storage  204 . In this case, if the downward movement of the material storage  204  is detected using the proximity sensor  207 , the movement controller  209  stops the downward movement of the platform  205 . Therefore, it is possible to prevent damage to the bottom surface  242  caused by an excessive load applied from the platform  205  (shaping pad  252 ) to the bottom surface  242  of the material storage  204 . 
     Note that although not shown, the three-dimensional shaping apparatus  200  may be provided with a notifier that sends an alert notification based on the detection results of the photosensor  231  and the proximity sensor  207  or the detection result of one of the photosensor  231  and the proximity sensor  207 . The alert notification sent by the notifier is implemented by a sound, light, a vibration, a text message, or the like. However, the present invention is not limited to them. 
     A procedure of positioning the platform  205  will be described next with reference to  FIGS. 3A to 3J . As shown in  FIG. 3A , for example, the position of the platform  205  in the vertical direction (plumb direction) is adjusted (Z-axis position adjustment) in a manual mode of software for controlling the three-dimensional shaping apparatus  200 , and the platform  205  is lowered to a position near the bottom surface  242 , made of glass, of the material storage  204 . That is, if the platform support member  251  is moved in the vertical direction using the movement controller  209 , the platform  205  also moves in the vertical direction in accordance with the movement of the platform support member  251 . 
     The platform  205  is gradually, finely moved by visual observation by adjusting the moving distance of the platform  205  in the vertical direction (Z-axis direction) by, for example, 10 mm, 1 mm, or 0.1 mm. Then, the platform  205  is moved and lowered to a position at which a gap of 1 to 2 mm is generated between the shaping pad  252  provided on the platform  205  and the bottom surface  242  of the material storage  204 . 
     As shown in  FIG. 3B , the shaping pad  252  (shaping pad surface) and the bottom surface  242  are mated with each other by loosening the platform mounting screw  253  of the platform  205 . The platform mounting screw  253  is loosened to generate no gap between the shaping pad  252  and the bottom surface  242  and generate a gap between the platform  205  and the platform support member  251 . That is, the platform  205  is separated from the platform support member  251  by loosening the platform mounting screw  253 , and drops downward, thereby making it possible to mate the shaping pad  252  and the bottom surface  242  with each other. 
     As shown in  FIG. 3C , adjustment is performed so as to generate a gap of 50 to 100 μm between the platform  205  and the platform support member  251 . That is, as shown in  FIG. 3B , in this state, the platform mounting screw  253  is loosened. Thus, even if the platform support member  251  is moved in the vertical direction using the movement controller  209 , the platform  205  does not move in the vertical direction. Therefore, the platform support member  251  is moved in the vertical direction to generate a gap of 50 to 100 μm between the platform  205  and the platform support member  251 . 
     Note that in this case, if the photosensor  231  operates (an LED (Light Emitting Diode) is turned off) to prevent the position of the platform support member  251  from being lowered, the sensor adjustment stage  233  is used to lower the position of the photosensor  231 . In this way, by lowering the position of the photosensor  231 , the position of the platform  205  can be further lowered (adjusted to a position at which the LED is turned on). 
     As shown in the left view of  FIG. 3D , after the gap between the platform  205  and the platform support member  251  can be adjusted to have 50 to 100 μm, the platform mounting screw  253  is tightened to fix the platform  205  to the platform support member  251 . Then, as shown in the right view of  FIG. 3D , after the position of the platform  205  can be fixed, the photosensor  231  is finely adjusted to a position at which the LED is turned off (a position at which the LED is just turned off). 
     In this state, Z-axis origin return of the software for controlling the three-dimensional shaping apparatus  200  is turned on. That is, this state is set as the reference position of the position of the platform  205 . After the platform  205  is raised, the platform is lowered slowly, and stopped at a position where the LED of the photosensor  231  is turned off (see the right view of  FIG. 3E ). 
     As shown in the left view of  FIG. 3F , the platform mounting screw  253  is loosened, and the gap between the platform  205  and the platform support member  251  is checked. As shown in the right view of  FIG. 3F , if the checked gap is large, the position of the photosensor  231  is lowered. If the checked gap is small, the position of the photosensor  231  is raised. 
     As shown in  FIG. 3G , while checking the gap between the platform  205  and the platform support member  251 , the procedure shown in  FIGS. 3E and 3F  is repeated to loosen the platform mounting screw  253  and fix the position of the platform  205 , thereby determining the origin setting position. That is, if a slice has 50 μm, the gap between the platform  205  and the platform support member  251  is set to about 50 μm. If the slice has 5 μm, setting is made to generate no gap (a state in which the platform  205  and the platform support member  251  are in tight contact with each other but are not pressed against each other). The slice represents the setting value for the Z-axis at the time of three-dimensional shaping. As the setting value is smaller, shaping is performed more precisely. 
     As shown in  FIG. 3H , the position of the platform  205  is largely raised upward (for example, by 50 mm), and a resin or the like is charged as the material  241  to the material storage  204 . 
     As shown in  FIG. 3I , after the material  241  is charged, the position of the platform  205  is lowered to the origin setting position to immerse the shaping pad  252  in the material  241 , and the gap between the shaping pad  252  and the bottom surface  242  of the material storage  204  is confirmed. If it is necessary to adjust the gap between the shaping pad  252  and the bottom surface  242  of the material storage  204 , the procedure shown in  FIGS. 3F, 3G, and 3I  is repeated. 
     As shown in the left view of  FIG. 3J , while the platform  205  is raised, the material  241  is irradiated with the light beam  211  from the light source  201  located under the material storage  204 , thereby starting shaping of a three-dimensional shaped object  301 . As shown in the right view of  FIG. 3J , if the shaping of the three-dimensional shaped object  301  ends and another platform  205  is attached to the platform support member  251 , the procedure shown in  FIG. 3I  is performed to confirm and adjust the position of the platform  205 . 
     According to this example embodiment, since the platform  205  can be aligned accurately, it is possible to align the platform  205  and the bottom surface  242  of the material storage  204  correctly. In addition, since the platform  205  and the bottom surface  242  can be aligned correctly, it is possible to shape a high-precision three-dimensional shaped object, for example, a three-dimensional shaped object with an accuracy of the order of several microns. 
     Furthermore, according to this example embodiment, since the downward movement of the material storage  204  is detected by the proximity sensor  207  and the supporter  208  at the time of alignment of the platform  205 , the bottom surface  242  (glass thereof) of the material storage  204  is never damaged. 
     Third Example Embodiment 
     A three-dimensional shaping apparatus according to the third example embodiment of the present invention will be described with reference to  FIGS. 4 and 5 .  FIG. 4  is a view showing an outline of the arrangement of the three-dimensional shaping apparatus according to this example embodiment. Note that elements unnecessary for the description are not illustrated in  FIG. 4 , as needed. The three-dimensional shaping apparatus according to this example embodiment is different from the above-described second example embodiment in that elastic members, a load detector, and a notifier are provided. The remaining components and operations are the same as those in the second example embodiment. Hence, the same reference numerals denote the same components and operations, and a detailed description thereof will be omitted. 
     A three-dimensional shaping apparatus  400  further includes elastic members  401 , a load detector  402 , and a notifier  403 . 
     The elastic members  401  are provided on the lower surface of a material storage  204 . That is, the elastic members  401  are provided between a table  203  and the material storage  204 . The elastic members  401  serve as cushions that absorb a pressure applied from a platform  205  when the material storage  204  is pressed by the platform  205 . That is, if the table  203  and a bottom surface  242  of the material storage  204  are in direct contact with each other, the material storage  204  cannot avert the pressure applied from the platform  205 . Thus, the bottom surface  242  of the material storage  204  may be damaged. However, it is possible to prevent damage to the bottom surface  242  by providing the elastic members  401  between the table  203  and the bottom surface  242  of the material storage  204 , since the elastic members  401  absorb the pressure applied from the platform  205  to the material storage  204 . 
     The load detector  402  is provided between the platform  205  and a shaping pad  252 . The load detector  402  detects a load applied to the material storage  204 . Since the material storage  204  is provided with the elastic members  401 , the elastic members  401  can absorb a load to some extent. However, if an excessive load is applied, the bottom surface  242  is unwantedly damaged. To solve this problem, by using the load detector  402  to detect a load applied to the material storage  204 , it is possible to prevent damage to the bottom surface  242  of the material storage  204  and position the platform  205  more correctly. 
     The notifier  403  sends an alert notification based on the detection result of the load detector  402 . The alert notification sent by the notifier  403  is implemented by a sound, light, a vibration, a text message, or the like. However, the present invention is not limited to them. Note that the notifier  403  may send an alert notification based on the detection result of one of a photosensor  231 , a proximity sensor  207 , and the load detector  402 . Note also that the example in which the three-dimensional shaping apparatus  400  is provided with the elastic members  401  in addition to the supporter  208  has been explained above. However, in the three-dimensional shaping apparatus  400 , the elastic members  401  may be provided instead of the supporter  208 . 
       FIG. 5  is a flowchart for explaining the operation procedure of the three-dimensional shaping apparatus according to this example embodiment. In step S 501 , the three-dimensional shaping apparatus  400  causes a moving unit to move the platform  205  in the vertical direction. In step S 503 , the three-dimensional shaping apparatus  400  detects whether the material storage  204  has moved downward. If it is detected that the material storage  204  has not moved downward (NO in step S 503 ), the three-dimensional shaping apparatus  400  continues to move the platform  205 ; otherwise (YES in step S 503 ), the three-dimensional shaping apparatus  400  advances to the next step. In step S 505 , the three-dimensional shaping apparatus  400  controls the movement of the platform  205  by the moving unit. That is, the three-dimensional shaping apparatus  400  stops the movement of the platform  205 . In step S 507 , the three-dimensional shaping apparatus  400  determines whether the movement control of the platform  205  has ended. If the movement control of the platform  205  has not ended (NO in step S 507 ), the three-dimensional shaping apparatus  400  continues the movement control of the platform  205 ; otherwise (YES in step S 507 ), the three-dimensional shaping apparatus  400  ends the processing. Note that the flowchart shown in  FIG. 5  is equally applicable in the three-dimensional shaping apparatus  200  described in the second example embodiment. 
     According to this example embodiment, since the load detector is provided, it is possible to control the movement of the platform more reliably, and thus position the platform accurately. Furthermore, since the movement of the platform can be controlled more reliably, it is possible to effectively prevent damage to the bottom surface of the material storage. 
     Other Example Embodiments 
     While the invention has been particularly shown and described with reference to example embodiments thereof, the invention is not limited to these example embodiments. It will be understood by those of ordinary skill in the art that various changes in form and details may be made therein without departing from the spirit and scope of the present invention as defined by the claims. 
     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 example 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 example embodiments.