JP2023032489A - Three-dimensional molding device and abnormality detection device - Google Patents

Abstract

To accurately detect abnormality of unevenness on a surface of a powder bed.SOLUTION: A three-dimensional modeling device 1 comprises: a supply unit 35 for forming a powder bed PA on a main surface 6a of a table 6 by supplying powder P onto the main surface 6a; an irradiation unit 33 for obtaining a three-dimensional object M in which the powder P is solidified by irradiating the powder bed PA with an electron beam; an abnormality detection unit 34 for detecting that an unevenness of an application surface PB of the powder bed PA irradiated with the electron beam is not within an allowable range. The abnormality detection unit 34 comprises: a first detection plate 42A that faces the application surface PB in a normal direction D1; a second detection plate 42B configured to be displaced from a position separated from the first detection plate 42A in the normal direction D1 to a position in contact with the first detection plate 42A; and a continuity detection unit 43 for detecting continuity between the first detection plate 42A and the second detection plate 42B when the second detection plate 42B contacts the first detection plate 42A according to a force acting in the normal direction D1.SELECTED DRAWING: Figure 4

Description

The present disclosure relates to a three-dimensional modeling apparatus and an anomaly detection apparatus.

Patent Documents 1 to 3 disclose techniques related to three-dimensional modeling apparatuses. A three-dimensional modeling apparatus forms a three-dimensional object by repeating an operation of laying powder of metal or the like in a layer and an operation of solidifying the powder by irradiating it with an energy beam. In a three-dimensional modeling apparatus, when solidifying powder by irradiation with an energy beam, unintended large projecting solidified substances (projections) may be formed on the surface of the powder bed. Such projections may cause problems such as interfering with a coating mechanism for spreading the powder in layers. Therefore, in order to avoid interference between the projections and the coating mechanism, it is conceivable to detect the presence of the projections as an abnormality in the unevenness of the surface of the powder bed. For example, Patent Literature 1 discloses a three-dimensional modeling apparatus equipped with a contact detection sensor for detecting such protrusions.

The contact detection sensor disclosed in Patent Document 1 detects the presence or absence of a projection to be detected (hereinafter referred to as "target projection") while moving horizontally on the surface of the powder bed. The contact detection sensor includes a pair of leaf springs extending vertically on the surface of the powder bed and arranged with a gap in the moving direction of the contact detection sensor, and a conduction sensor for detecting electrical connection between the pair of leaf springs. have. The lower ends of the pair of leaf springs are maintained at a height that interferes with the target projection. When the contact detection sensor moves horizontally in this state, when the pair of leaf springs collide with the target projection, one of the leaf springs is displaced so as to bend toward the other leaf spring. Then, when one leaf spring contacts the other leaf spring, the conduction sensor detects conduction between the pair of leaf springs, and the contact detection sensor detects the presence of the target projection on the surface of the powder bed, That is, it detects that the irregularities on the surface of the powder bed are abnormal.

JP 2020-026577 A JP 2004-277881 A JP 2007-100199 A

In the contact detection sensor described above, the height of the lower ends of the pair of leaf springs, that is, the vertical spacing between the surface of the powder bed and the pair of leaf springs is important in order to accurately detect the target projection. . However, under the high-temperature environment during molding, the vertical dimensions of the pair of leaf springs tend to change greatly due to the influence of thermal expansion. If the change in the vertical dimension of the pair of leaf springs changes significantly, the vertical distance between the surface of the powder bed and the pair of leaf springs will change significantly accordingly. Even protrusions can be detected. Therefore, with the contact detection sensor described above, it is difficult to accurately detect the target projection, that is, to accurately detect an abnormality in the unevenness of the surface of the powder bed.

The present disclosure describes a three-dimensional modeling apparatus and an anomaly detection apparatus capable of accurately detecting irregularities on the surface of a powder bed.

A three-dimensional modeling apparatus according to an aspect of the present disclosure includes a supply unit that supplies powder onto the main surface of a table to form a powder bed that is a stack of powder on the main surface, and an energy beam on the powder bed. and an anomaly detection part for detecting that the unevenness of the surface of the powder bed irradiated with the energy beam is not within an allowable range, and an anomaly The detection unit is arranged between a first conductor facing the surface in the normal direction of the main surface and between the surface and the first conductor in the normal direction, and is separated from the first conductor in the normal direction. a second conductor that is configured to be displaced from a position where it contacts the first conductor to a position that contacts the first conductor; and a continuity detection unit for detecting continuity between the first conductor and the second conductor.

An abnormality detection device according to one embodiment of the present disclosure is an abnormality detection device for detecting that unevenness of the surface of a powder bed irradiated with an energy beam on the main surface of a table is not within an allowable range, and a first conductor facing in the normal direction of the main surface, and the first conductor from a position separated from the first conductor in the normal direction. and the first conductor and the first conductor when the second conductor contacts the first conductor in response to a force acting in the normal direction. and a continuity detection unit that detects continuity with the two conductors.

In the three-dimensional modeling apparatus and the anomaly detection apparatus described above, when a projection that is not within the allowable range (hereinafter referred to as a "target projection") exists on the surface of the powder bed, the second conductor receives a force from the target projection. is displaced in the normal direction by and contacts the first conductor. At this time, the continuity detection unit detects continuity between the first conductor and the second conductor. Therefore, when the continuity detection unit detects the continuity between the first conductor and the second conductor, the unevenness of the surface of the powder bed is not within the allowable range, that is, the unevenness of the surface of the powder bed is abnormal. can be detected. In this way, when the first conductor and the second conductor are arranged side by side in the normal direction, these conductors are arranged along the surface of the powder bed so as to stand against the surface of the powder bed. Compared to the arrangement, the influence of the dimensional change of the first conductor and the second conductor due to thermal expansion on the abnormality detection accuracy of the unevenness of the surface of the powder bed can be reduced. Therefore, in the configuration described above, even if the dimensions of the first conductor and the second conductor change due to thermal expansion, the positions of the first conductor and the second conductor remain normal with respect to the surface of the powder bed. It is possible to suppress a situation in which there is a large change in the linear direction. That is, even in a high-temperature environment, the distance between the first conductor, the second conductor, and the surface of the powder bed can be maintained. As a result, the target projection can be detected with high accuracy. As a result, it is possible to accurately detect an irregularity in the unevenness of the surface of the powder bed.

In some embodiments, when the continuity detection unit detects continuity between the first conductor and the second conductor, the abnormality detection unit determines that the unevenness of the surface of the powder bed is not within the allowable range. It may further include an abnormality determination unit that determines that the unevenness of the surface is in an abnormal state. In this case, the state in which the first conductor and the second conductor are electrically connected can be determined as the state in which the unevenness of the surface of the powder bed is abnormal.

In some aspects, the second conductor may be a conductive plate having a normal direction as a thickness direction, and may have a curved portion curved toward the surface in the normal direction. In this case, the presence of the curved portion facilitates adjustment of the spacing between the second conductor and the surface of the powder bed. As a result, it becomes possible to detect the target projection with higher accuracy.

In some aspects, the first conductor and the second conductor are movable relative to the surface in a scanning direction along the major surface, and the curved portion is , may exhibit an arcuate shape that is convex toward the surface. In this configuration, when the target projection exists on the surface of the powder bed, the curved portion of the second conductor receives force from the target projection and is easily displaced in the normal direction. As a result, the second conductor can be more reliably brought into contact with the first conductor when the target projection exists on the surface of the powder bed. That is, it is possible to more reliably detect the target projection.

In some aspects, the curved portion may be configured to elastically deform from a position spaced apart from the first conductor to a position in contact with the first conductor. In this case, it is possible to easily realize a configuration in which the second conductor is displaced from a position separated from the first conductor to a position in contact with the first conductor.

In some aspects, the three-dimensional modeling apparatus further includes an insulating support that supports the first conductor and the second conductor, both ends of the second conductor are supported by the support, and the second conductor The portion between the ends of the body may constitute the bend. In this case, it is possible to easily configure the second conductor having the curved portion while ensuring electrical insulation between the first conductor and the second conductor.

In some aspects, the three-dimensional modeling apparatus is disposed between the surface and the second conductor in the normal direction, and is in contact with the second conductor from a position separated from the second conductor in the normal direction. The continuity detection unit detects the third conductor when the third conductor contacts the second conductor in response to a force acting in the normal direction. outputting a first continuity detection signal indicating that continuity between the body and the second conductor is detected, and when the second conductor contacts the first conductor in accordance with the force acting in the normal direction, the first A second continuity detection signal indicating that continuity between the two conductors and the first conductor has been detected may be output. In this case, the height of the target projection present on the surface of the powder bed can be detected stepwise according to the state of continuity between the first conductor, the second conductor, and the third conductor.

In some embodiments, when the continuity detection unit detects continuity among any one of the first conductor, the second conductor, and the third conductor, the abnormality detection unit detects that the unevenness of the surface of the powder bed is within the allowable range. It further has an abnormality determination unit that determines that the unevenness of the surface of the powder bed is in an abnormal state, and the abnormality determination unit determines that the powder bed is not When it is determined that the unevenness of the surface of the powder bed is the first abnormal state, and the continuity detection unit outputs both the first continuity detection signal and the second continuity detection signal, the unevenness of the surface of the powder bed is the first abnormal state may be determined to be different second abnormal states. In this configuration, when the continuity detection unit outputs only the first continuity detection signal, a state in which a target projection having a height not reaching at least the first conductor exists on the surface of the powder bed (first abnormal state). can be determined to be On the other hand, when the continuity detection unit outputs both the first continuity detection signal and the second continuity detection signal, the number of target projections on the surface of the powder bed is higher than when the continuity detection unit outputs only the first continuity detection signal. It can be determined that the state exists (second abnormal state). As described above, according to the above-described configuration, it is possible to detect an abnormal state of unevenness on the surface of the powder bed in a stepwise manner according to the conduction state of the first conductor, the second conductor, and the third conductor. It becomes possible.

In some aspects, the third conductor may be a conductive plate having a normal direction as a thickness direction, and may have a curved portion curved toward the surface in the normal direction. In this case, the presence of the curved portion facilitates adjustment of the distance between the third conductor and the surface of the powder bed. As a result, it becomes possible to detect the target projection with higher accuracy.

In some aspects, the three-dimensional modeling apparatus further includes a control unit that controls operations of the supply unit and the irradiation unit, and the control unit controls the surface unevenness when the abnormality determination unit determines that the surface unevenness is in the first abnormal state. Then, the supply unit and the irradiation unit are caused to perform a recovery operation to eliminate the irregularity of the surface unevenness, and when the abnormality determination unit determines that the surface unevenness is in the second abnormal state, the supply unit and the irradiation unit You can stop the operation. In this way, by taking appropriate measures according to the abnormal state of irregularities on the surface of the powder bed, it is possible to reliably carry out the modeling process in a normal state.

According to some aspects of the present disclosure, there are provided a three-dimensional modeling apparatus and an abnormality detection apparatus capable of accurately detecting irregularities in the surface irregularities of the powder bed.

FIG. 1 is a cross-sectional view showing a three-dimensional modeling apparatus according to one embodiment. 2 is a plan view showing a processing section of the three-dimensional modeling apparatus of FIG. 1. FIG. FIG. 3 is a block diagram showing the configuration of the control unit of the three-dimensional modeling apparatus of FIG. 1; FIG. 4 is a cross-sectional view showing an abnormality detection unit of the three-dimensional fabrication device of FIG. 1; FIG. 5(a) is a cross-sectional view showing a state in which continuity is established between the second detection plate and the third detection plate in the cross section shown in FIG. FIG. 5(b) is a cross-sectional view showing a state in which the first detection plate, the second detection plate, and the third detection plate are all electrically connected in the cross section shown in FIG. FIG. 6 is a flow chart showing the operation performed by the control unit when forming one layer of the modeled object. FIG. 7 is a flowchart showing details of the recovery operation shown in FIG. FIG. 8(a) is a diagram for explaining a problem that a conventional abnormality detection unit has. FIG.8(b) is a figure for demonstrating the effect which the abnormality detection unit which concerns on one Embodiment shows. FIG. 9 is a cross-sectional view showing a modification of the abnormality detection unit. FIG. 10(a) is a cross-sectional view showing a state in which the second detection plate and the third detection plate are electrically connected in the cross section shown in FIG. FIG. 10(b) is a cross-sectional view showing a state in which the first detection plate, the second detection plate, and the third detection plate are all electrically connected in the cross section shown in FIG. FIG. 11 is a cross-sectional view showing another modification of the abnormality detection unit. 12A is a cross-sectional view showing a state in which the second detection plate and the third detection plate are electrically connected in the cross section shown in FIG. 11. FIG. FIG. 12(b) is a cross-sectional view showing a state in which the first detection plate, the second detection plate, and the third detection plate are all electrically connected in the cross section shown in FIG.

Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. In the description of the drawings, the same elements are denoted by the same reference numerals, and overlapping descriptions are omitted as appropriate.

A three-dimensional modeling apparatus 1 shown in FIG. 1 is a so-called 3D printer. The three-dimensional modeling apparatus 1 employs an electron beam as an energy beam. That is, the three-dimensional modeling apparatus 1 employs a so-called electron gun powder bed melting method. The three-dimensional modeling apparatus 1 uses powder P to model a three-dimensional object M. As shown in FIG. The three-dimensional modeling apparatus 1 first supplies powder P onto the table. After that, the three-dimensional modeling apparatus 1 irradiates the powder P with an electron beam. The powder P irradiated with the electron beam is melted or sintered. Then, when the three-dimensional modeling apparatus 1 stops the irradiation of the electron beam, the temperature of the powder P drops, so the powder P solidifies. The three-dimensional modeling apparatus 1 models a three-dimensional modeled object M by repeatedly performing such irradiation and stopping of the electron beam.

The modeled object M is, for example, a machine part or the like. The modeled object M may be another structure. The powder P is composed of many powder bodies. The powder P is, for example, metal powder. Examples of metal powders include titanium-based metal powders, Inconel (registered trademark) powders, and aluminum powders. The powder P is not limited to metal powder. The powder P may be, for example, resin powder or powder containing carbon fiber and resin such as CFRP (Carbon Fiber Reinforced Plastics). The powder P may be any other powder having electrical conductivity. The powder P need not be electrically conductive. For example, when using a laser as the energy beam, the powder P does not have to be electrically conductive.

As shown in FIG. 1 , the 3D modeling apparatus 1 includes a housing 5 , a driving section 10 , a modeling processing section 30 and a control section 50 . Housing 5 is supported by a plurality of columns. The housing 5 forms a modeling space S. As shown in FIG. The modeling space S is a pressure-reduced airtight space for processing the powder P by the modeling processing section 30 . In the modeling space S, a table 6 and a modeling tank 7 are arranged. A table 6 is a processing table on which modeling processing is performed. The table 6 has a disk shape, for example, and is installed rotatably about a rotation axis C. As shown in FIG. The rotation axis C is set, for example, along the vertical direction. On the main surface 6a of the table 6, the powder P, which is the raw material of the modeled object M, is arranged. A main surface 6a of the table 6 is a modeling surface (upper surface) on which the modeled object M is modeled. The main surface 6a is arranged so as to be orthogonal to the rotation axis C. As shown in FIG. That is, the normal direction D1 of the main surface 6a matches the direction in which the rotation axis C extends.

In the following description, the terms "upper" and "lower" are used on the basis that the normal direction D1 is along the vertical direction. In a state where the normal direction D1 is along the vertical direction, the word "down" indicates the side of the ground in the vertical direction, and the word "up" indicates the side opposite to the ground in the vertical direction. Also, the “circumferential direction D2” indicates the direction along the ring around the rotation axis C. As shown in FIG. The “circumferential direction D2” includes a rotation direction D21 in which the table 6 rotates about the rotation axis C. As shown in FIG. “Radial direction” indicates a direction perpendicular to the rotation axis C. As shown in FIG. In the present embodiment, the “circumferential direction D2” and the “radial direction” are directions along the surface direction along the main surface 6a of the table 6 . That is, the "circumferential direction D2" and the "radial direction" are included in the surface direction of the main surface 6a. Here, the "plane direction" may be any direction along the main surface 6a of the table 6, and includes directions other than the "circumferential direction D2" and the "radial direction".

The drive unit 10 realizes various operations required for modeling. For example, the drive unit 10 rotates and raises/lowers the table 6 . The driving section 10 has a rotation unit 11 and a lifting unit 12 . The rotation unit 11 rotates the table 6 around the rotation axis C. As shown in FIG. The upper end of the rotating unit 11 is connected to the table 6, and the lower end of the rotating unit 11 is connected to a drive source (eg, motor). The elevating unit 12 elevates the table 6 . This elevation is performed along the normal direction D1.

The modeling processing section 30 obtains a modeled object M by processing the powder P. As shown in FIG. The processing of the powder P includes, for example, powder P supply processing, powder P preheating (preheating processing), powder P modeling processing, and powder P abnormality detection processing. The modeling processing unit 30 is arranged above the main surface 6a of the table 6 and arranged at a position facing the main surface 6a in the normal direction D1. As shown in FIG. 2, the modeling processing section 30 has, for example, a first modeling processing unit 31A and a second modeling processing unit 31B. The first modeling processing unit 31A and the second modeling processing unit 31B are arranged side by side along the circumferential direction D2. The first modeling processing unit 31A and the second modeling processing unit 31B are located at rotationally symmetrical positions of 180° with respect to the rotation axis C, for example. The first modeling processing unit 31A and the second modeling processing unit 31B have, for example, the same components as each other.

Hereinafter, when the first modeling processing unit 31A and the second modeling processing unit 31B are not particularly distinguished and described, they are collectively referred to simply as the "modeling processing unit 31". Note that the first modeling processing unit 31A and the second modeling processing unit 31B may have components different from each other. For example, one component of the first modeling processing unit 31A and the second modeling processing unit 31B may be part of the other component.

The modeling processing unit 31 has, for example, a heating section 32 , an irradiation section 33 , an abnormality detection section 34 (an abnormality detection device), and a supply section 35 . The supply unit 35 supplies the powder P onto the main surface 6 a of the table 6 . Supply unit 35 includes a raw material tank and a powder coating mechanism. The raw material tank stores the powder P and supplies the powder P onto the main surface 6 a of the table 6 . The powder coating mechanism smoothes the surface (upper surface) of the uppermost layer of the laminate of powder P supplied onto the main surface 6 a of the table 6 . Hereinafter, this stack of powder P will be referred to as "powder bed PA". The “powder bed PA” here refers to both the laminate of the powder P before being irradiated with the electron beam and the laminate including the solidified product of the powder P formed by the irradiation of the electron beam. The powder application mechanism is, for example, a rod-shaped or plate-shaped member, and is arranged on the main surface 6a of the table 6 so as to extend in the radial direction. As the powder coating mechanism, for example, a recoater, a roller, a rod-shaped member, or a brush may be used. As the table 6 rotates, the powder coating mechanism comes into contact with the surface of the powder bed PA to evenly spread the powder. In this way, the powder bed PA is applied on the main surface 6a with a uniform thickness. Hereinafter, the surface of the powder bed PA applied onto the main surface 6a will be referred to as "application surface PB".

The heating unit 32 preheats (preheats) the powder bed PA applied on the main surface 6a. The heating unit 32 raises the temperature of the powder bed PA by, for example, radiant heat. The heating unit 32 may be, for example, an infrared heater or a heater that heats by another method. Here, "preheating" means heating so that the temperature of the powder P in the preheating area becomes higher than the temperature of the powder P in the supply area.

The irradiation unit 33 irradiates the preheated powder bed PA with an electron beam. The irradiation unit 33 is, for example, an electron gun. The irradiation unit 33 generates an electron beam according to the potential difference generated between the cathode and the anode. Then, the irradiation unit 33 irradiates a desired position of the powder bed PA with the electron beam converged by adjusting the electric field. The electron beam heats the powder P in the powder bed PA. That is, the irradiation unit 33 applies energy to the powder P. As shown in FIG. As a result, the powder P is heated and melted or sintered. The heating temperature of the powder P at this time is higher than the preheating temperature of the powder P by the heating unit 32 and is a temperature at which the modeled object M can be formed (that is, the sintering temperature or the melting temperature). Then, when the irradiation unit 33 stops irradiating the powder P with the electron beam, the temperature of the powder P decreases, so that the powder P solidifies. As the table 6 rotates, the object M is formed by repeating irradiation and stopping of the electron beam to the powder P a plurality of times.

The abnormality detection unit 34 detects an abnormality in unevenness of the application surface PB of the powder bed PA irradiated with the electron beam. A state in which unevenness of the coating surface PB is abnormal means a state in which the unevenness of the coating surface PB is out of the allowable range. The state in which the unevenness of the coating surface PB is not within the allowable range means that the height (degree) of the unevenness of the coating surface PB is not within a certain allowable range. A projection having an unacceptable height) exists on the coating surface PB. An unintended large protrusion is, for example, a large warped portion of the modeled object M that is generated when the powder P is irradiated with the electron beam. The melting and solidification of the powder P by electron beam irradiation is accompanied by thermal deformation due to the material properties of the powder P. At this time, the modeled object M may be greatly warped so as to protrude upward from the application surface PB by receiving an unintended thermal stress.

When such a large projection (that is, the warped portion of the model M) exists on the application surface PB, the operation of the supply unit 35 may be hindered by the contact of the supply unit 35 with the projection. It may be difficult for the device 1 to perform the modeling process normally. Therefore, when detecting a large protrusion to be detected (hereinafter referred to as "target protrusion TP"), the abnormality detection unit 34 detects that the unevenness of the coating surface PB is abnormal. In this embodiment, the target projections TP (see FIGS. 5A and 5B to be described later) refer to projections having a height of 0.1 mm or more with respect to the coating surface PB. In other words, a state in which a protrusion having such a height exists on the coating surface PB is defined as a state in which the unevenness of the coating surface PB is not within the allowable range. The height of the target projection TP may be the height of the tip (upper end) of the target projection TP when the height of the coating surface PB in the normal direction D1 is used as a reference.

In this embodiment, when detecting the target projection TP on the application surface PB, the abnormality detection unit 34 detects the size (height) of the target projection TP in stages. When the target projection TP has a height H1 within a range of, for example, 0.1 mm or more and less than 1 mm (hereinafter referred to as a “restorable range”) (see FIG. 5A described later), the coating surface PB is Normal modeling processing can be continued by performing recovery operation for eliminating the state in which the target projection TP exists. Therefore, when the target projection TP having the height H1 within the restorable range exists on the application surface PB, the modeling process can be continued without stopping, so that the unevenness of the application surface PB can be treated as a mild abnormal state ( first abnormal state). Details of the recovery operation will be described later. On the other hand, for example, when the height H2 of the target projection TP is in a range of 1 mm or more (hereinafter referred to as a non-restorable range) (see FIG. 5B described later), the modeled object M is large as a whole. Most likely deformed. In this case, the modeling process cannot be continued in a normal state. Therefore, when the target projection TP having the height H2 in the unrecoverable range exists on the coating surface PB, the unevenness of the coating surface PB is a severe abnormal state (second abnormal state) in which the modeling process should be abnormally stopped. I can say.

Therefore, when the abnormality detection unit 34 detects the target projection TP having the height H1 within the restorable range, the abnormality detection unit 34 detects the first abnormality detection signal S1 ( 3 to be described later) is output to the control unit 50 . On the other hand, when the abnormality detection unit 34 detects the target projection TP having the height H2 within the unrecoverable range, the second abnormality detection signal S2 ( 3 to be described later) is output to the control unit 50 . Note that when the target projection TP does not exist on the coating surface PB (that is, when a projection having a height of less than 0.1 mm exists on the coating surface PB, or when there is no projection on the coating surface PB) Since the normal modeling process can be continued without performing the recovery operation, it can be said that the unevenness of the coating surface PB is within the allowable range, that is, the unevenness of the coating surface PB is normal. In this case, the abnormality detection unit 34 does not detect an abnormality in the unevenness of the coating surface PB. Therefore, when the unevenness of the coating surface PB is within the allowable range, the height of the protrusions that may exist on the coating surface PB is within a certain range (for example, less than 0.1 mm) that allows the continuation of the normal modeling process. say something The continuation of normal modeling processing here means a state in which normal modeling processing can be continued without performing a recovery operation. Therefore, when the unevenness of the coating surface PB is within the allowable range, it can be said that the height of the protrusions that may exist on the coating surface PB is not within the recoverable range or the non-restorable range. The unevenness of the coating surface PB is not within the allowable range means that the height of the protrusions that may exist on the coating surface PB is within a range (for example, less than 0.1 mm) that does not allow the continuation of normal modeling processing. The range in which the continuation of normal modeling processing is not permitted includes both the recoverable range in which normal modeling processing cannot be continued without recovery action, and the non-recoverable range in which normal modeling processing cannot be continued even if recovery action is performed. means Therefore, when the unevenness of the coating surface PB is not within the allowable range, it can be said that the height of the protrusions that may exist on the coating surface PB is within the restorable range or the unrestorable range.

As shown in FIG. 2, the heating unit 32, the irradiation unit 33, the abnormality detection unit 34, and the supply unit 35 rotate above the main surface 6a of the table 6 in a rotation direction D21 (counterclockwise direction in FIG. 2). are arranged in this order along the With the heating unit 32, the irradiation unit 33, the abnormality detection unit 34, and the supply unit 35 arranged side by side in the rotation direction D21, the table 6 rotates in the rotation direction D21. Heat treatment, modeling processing by the irradiation unit 33, abnormality detection processing by the abnormality detection unit 34, and supply processing by the supply unit 35 are performed in parallel. By repeating each process according to the rotation of the table 6, the modeled object M is modeled on the main surface 6a. When each process is performed in parallel in this way, there is an advantage that the modeling time of the modeled object M can be shortened as compared with the case where each process is performed sequentially.

A control unit 50 shown in FIG. 1 is an electronic control unit that controls the entire three-dimensional modeling apparatus 1 . The control unit 50 is, for example, a computer including hardware such as a CPU (Central Processing Unit), ROM (Read Only Memory), and RAM (Random Access Memory), and software such as programs stored in the ROM. The form and location of the control unit 50 are not particularly limited. The control section 50 may be electrically connected to the driving section 10 and the modeling processing section 30 . As shown in FIG. 3, the control unit 50 includes, as functional components, an operation control unit 51 that controls the operations of the drive unit 10 and the modeling processing unit 30, and an operation selection unit that selects the control contents of the operation control unit 51. a portion 52; These functional components are implemented by the CPU executing programs.

The operation control unit 51 performs rotation control for rotating the table 6 . For example, the operation control unit 51 sets the rotational speed of the table 6 and the like. The operation control section 51 outputs a control signal for controlling the rotation of the table 6 to the rotation unit 11, and the rotation unit 11 operates according to the control signal. As a result, the table 6 rotates in the rotation direction D21 at a constant rotation speed, for example.

The operation control unit 51 performs elevation control for raising and lowering the table 6 . For example, the operation control unit 51 sets the lowering speed of the table 6 and the like. The operation control section 51 outputs a control signal for controlling the elevation of the table 6 to the elevation unit 12, and the elevation unit 12 operates according to the control signal. As a result, the table 6 descends, for example, at a constant descent speed. The descending speed of the table 6 may be determined according to the rotation speed of the table 6, for example.

The operation control unit 51 performs supply control for supplying the powder P onto the main surface 6 a of the table 6 . For example, the operation control unit 51 sets the timing of supplying the powder P onto the main surface 6a, the supply amount of the powder P, the operation of the powder coating mechanism, and the like. The operation control unit 51 outputs a control signal for performing supply control to the supply unit 35, and the supply unit 35 operates according to the control signal. As a result, the powder P on the main surface 6a of the table 6 is spread evenly as the table 6 rotates, forming a powder bed PA on the main surface 6a.

The operation control unit 51 performs preheating control for preheating the powder bed PA formed on the main surface 6 a of the table 6 . For example, the operation control unit 51 sets the amount of heat to be applied to the powder bed PA. The amount of heat given to the powder bed PA may be determined according to the material and type of the powder P, the rotation speed of the table 6, and the like. The operation control unit 51 outputs a control signal for preheating control to the heating unit 32, and the heating unit 32 operates according to the control signal. As a result, the powder bed PA on the main surface 6a is preheated at the heating section 32 position.

The operation control unit 51 controls irradiation of the electron beam when the powder P in the powder bed PA is melted or sintered. For example, the operation control unit 51 sets the timing of starting the irradiation of the electron beam, the timing of ending the irradiation of the electron beam, the irradiation position of the electron beam, and the like. The irradiation position of the electron beam is set to a region where the modeled object M is to be formed on the coating surface PB of the powder bed PA. Three-dimensional CAD (Computer Aided Design) data of the object M is input to the motion control unit 51 . The motion control unit 51 generates two-dimensional slice data based on this three-dimensional CAD data. The slice data is, for example, horizontal cross-sectional data of the modeled object M, and is a collection of a large number of data corresponding to vertical positions. The motion control unit 51 sets the irradiation position of the electron beam based on this slice data. The operation control unit 51 outputs a control signal for controlling irradiation to the irradiation unit 33, and the irradiation unit 33 operates according to the control signal. As a result, the preheated powder P melts and then solidifies at the electron beam irradiation position. By solidifying the powder P, a modeled object M is formed.

The operation control unit 51 performs abnormality detection control of the abnormality detection unit 34 when detecting abnormality in the unevenness of the coating surface PB. For example, the operation control unit 51 sets the timing to start detection by the abnormality detection unit 34, the timing to end detection by the abnormality detection unit 34, and the like. The operation control unit 51 outputs a control signal for performing abnormality detection control to the abnormality detection unit 34, and the abnormality detection unit 34 operates according to the control signal. In this way, the operation control unit 51 executes a series of modeling processes for forming the modeled object M by performing rotation control, elevation control, preheating control, irradiation control, abnormality detection control, and supply control of the table 6. do.

The operation selection unit 52 selects the control content of the operation control unit 51 according to the detection result by the abnormality detection unit 34 . The abnormality detection unit 34 outputs the first abnormality detection signal S<b>1 or the second abnormality detection signal S<b>2 to the operation selection unit 52 when detecting that there is an abnormality in the unevenness of the coating surface PB. The operation selection unit 52 determines the abnormal state of unevenness of the coating surface PB according to the output of the first abnormality detection signal S1 or the second abnormality detection signal S2. Then, the operation control unit 51 outputs an instruction signal S3 to the operation control unit 51 to instruct the control content of the operation control unit 51 according to the determination result. The operation control section 51 performs operation control according to the instruction signal S3. Control contents of the operation control unit 51 include normal operation, recovery operation, and abnormal stop operation. A normal operation is an operation for performing normal modeling processing including supply processing, preheat processing, and irradiation processing. The recovery operation is an operation for recovering from a state in which there is an abnormality in the unevenness of the coating surface PB to a state in which there is no abnormality. The abnormal stop operation is an operation for abnormally stopping the modeling process.

When neither the first abnormality detection signal S1 nor the second abnormality detection signal S2 is received from the abnormality detection section 34, the operation selection section 52 determines that there is no abnormality in the uneven state of the coating surface PB. , normal operation is selected as the control content of the operation control unit 51 . In this case, the motion control unit 51 controls the driving unit 10 and the modeling processing unit 30 so as to continue normal modeling processing.
When the operation selection unit 52 receives the first abnormality detection signal S1 from the abnormality detection unit 34, that is, when it is determined that the unevenness of the coating surface PB is in a mild abnormal state, the operation control unit 51 controls the Select a recovery action. In this case, the control contents of the operation control unit 51 are switched from the normal operation to the restoration operation. Then, the operation control unit 51 controls the driving unit 10 and the modeling processing unit 30 so as to restore the unevenness of the application surface PB to a normal state.

The recovery operation is an operation in which a series of modeling processes by preheating control, irradiation control, and supply control are repeatedly performed while changing the modeling conditions of the abnormal occurrence location (that is, the position where the target projection TP exists) on the coating surface PB. be. The change in modeling conditions includes, for example, changing the scanning speed of the irradiation unit 33 and changing the current value of the electron beam. By changing the modeling conditions in this way, the formation speed of the target projection TP is made relatively slower than the formation speed of the layer of the surrounding modeled object M. When a series of modeling processes are performed in this state, the height of the target projection TP relative to the application surface PB becomes relatively low as the modeling process progresses.

As a result, since the target projection TP relative to the coating surface PB is gradually lowered, the target projection TP can be embedded in the coating surface PB. That is, the restoration operation is an operation for embedding the target projection TP in the coating surface PB. In this way, the state in which the target projections TP exist on the coating surface PB is eliminated. That is, the unevenness of the coating surface PB is restored to a normal state. The operation selection unit 52 selects the normal operation after restoring the unevenness of the application surface PB to a normal state. Therefore, the operation control unit 51 resumes the normal operation after finishing the restoration operation.

On the other hand, when the operation selection unit 52 receives the second abnormality detection signal S2 from the abnormality detection unit 34, that is, when it is determined that the unevenness of the coating surface PB is in a severe abnormal state, the operation control unit 51 controls the operation selection unit 52. Select abnormal stop action as the content. In this case, the control content of the operation control unit 51 is switched from normal operation to abnormal stop operation. Then, the operation control unit 51 forcibly stops the operations of the driving unit 10 and the modeling processing unit 30, and forcibly stops the series of modeling processing.

Here, the details of the configuration of the abnormality detection unit 34 will be described. As shown in FIG. 2, the abnormality detector 34 is arranged to extend radially with respect to the rotation axis C. As shown in FIG. The abnormality detection unit 34 is arranged between the supply unit 35 and the irradiation unit 33 in the circumferential direction D2. The abnormality detection unit 34 is arranged, for example, at a position adjacent to the supply unit 35 in the direction opposite to the rotation direction D21. The abnormality detection unit 34 may be fixed to the supply unit 35 in the opposite direction. The direction opposite to the rotation direction D21 matches the scanning direction (moving direction) of the abnormality detection unit 34 with respect to the table 6 . Therefore, the direction opposite to the rotation direction D21 will be described below as the scanning direction D22. The abnormality detection section 34 has a plurality of abnormality detection units 40 for detecting an abnormality in the uneven state of the coating surface PB. Each abnormality detection unit 40 is linearly arranged along the radial direction. Therefore, each abnormality detection unit 40 is arranged at a position different from each other in the radial direction. Each abnormality detection unit 40 may be fixed to each other in the radial direction. Each abnormality detection unit 40 has, for example, the same configuration as each other.

FIG. 4 shows a cross section of the abnormality detection unit 40 taken along a plane along the normal direction D1 and the circumferential direction D2. As shown in FIG. 4, the abnormality detection unit 40 includes an insulator 41 (support), a first detection plate 42A (first conductor), a second detection plate 42B (second conductor), and a third detection plate 42C. (third conductor), a continuity detection unit 43, and an abnormality determination unit 44. Hereinafter, when the first detection plate 42A, the second detection plate 42B, and the third detection plate 42C are not described separately, they are collectively referred to simply as the "detection plate 42".

The insulator 41 is a block-shaped member having electrical insulation. The insulator 41 is fixed at a position spaced upward from the coating surface PB with a predetermined gap. The insulator 41 is fixed, for example, to the supply portion 35 (see FIG. 2) adjacent in the circumferential direction D2. Therefore, when the table 6 rotates in the rotation direction D21, the insulator 41 rotates (moves) relatively to the table 6 together with the supply unit 35 in the scanning direction D22. A lower surface 41a of the insulator 41 faces the coating surface PB in the normal direction D1. A lower surface 41a of the insulator 41 functions as a support surface for supporting the first detection plate 42A, the second detection plate 42B, and the third detection plate 42C.

The lower surface 41a of the insulator 41 includes a pair of first support grooves 41b for supporting the first detection plate 42A, a pair of second support grooves 41c for supporting the second detection plate 42B, and a third detection plate 42C. includes a pair of third support grooves 41d for supporting the The pair of first support grooves 41b are spaced apart in the scanning direction D22 on the lower surface 41a of the insulator 41 and linearly extend in the radial direction. The pair of second support grooves 41c are arranged on the outer side of the pair of first support grooves 41b in the scanning direction D22 and extend linearly along the radial direction. The pair of third support grooves 41d are arranged on the outer side of the pair of second support grooves 41c in the scanning direction D22 and extend linearly along the radial direction. The spacing in the scanning direction D22 between the first support groove 41b and the second support groove 41c is set to be the same as the spacing in the scanning direction D22 between the second support groove 41c and the third support groove 41d.

The detection plate 42 is a conductive plate for detecting the target projection TP (that is, irregularities in the unevenness of the application surface PB), and is configured to be elastically deformable. Therefore, the detection plate 42 is made of a conductive and elastically deformable material. For example, the detection plate 42 may be made of a material having a higher elastic modulus than the modeled object M. The detection plate 42 is arranged between the lower surface 41a of the insulator 41 and the coating surface PB in the normal direction D1 so that the normal direction D1 is the thickness direction, and is curved so as to protrude downward. . The state in which the detection plate 42 is arranged so that the normal direction D1 is the thickness direction means that the detection plate 42 is arranged so that the thickness direction of the detection plate 42 is along the normal direction D1. In this state, the main surface of the detection plate 42 orthogonal to the thickness direction is arranged to face the coating surface PB in the normal direction D1. In other words, the detecting plate 42 is arranged so that the extending direction is along the surface direction. The detection plate 42 is supported by the lower surface 41 a of the insulator 41 . Therefore, when the table 6 rotates in the rotation direction D21, the detection plate 42 rotates (moves) relative to the table 6 together with the insulator 41 in the scanning direction D22. Since the detection plate 42 is supported by the insulator 41, the interval in the normal direction D1 between the coating surface PB and the detection plate 42 is maintained constant.

The first detection plate 42A, the second detection plate 42B, and the third detection plate 42C are arranged in this order from the lower surface 41a of the insulator 41 toward the coating surface PB in the normal direction D1. Therefore, the first detection plate 42A faces the coating surface PB in the normal direction D1 via the second detection plate 42B and the third detection plate 42C. The first detection plate 42A is supported by the pair of first support grooves 41b while being curved in the normal direction D1 from the lower surface 41a of the insulator 41 toward the coating surface PB. Specifically, both end portions 42a of the first detection plate 42A in the scanning direction D22 are fitted into the pair of first support grooves 41b without gaps. As a result, both ends 42a of the first detection plate 42A are supported and fixed to the pair of first support grooves 41b, respectively. A portion between both ends 42a of the first detection plate 42A is a curved portion 42b that is curved so as to be convex toward the coating surface PB from the both ends 42a in the normal direction D1.

As shown in FIG. 4, the cross-sectional shape of the curved portion 42b of the first detection plate 42A is arcuate so as to project from both ends 42a of the first detection plate 42A toward the coating surface PB. "Arcuate" means an arcuate shape and includes, for example, arcuate, parabolic, C-shaped, and U-shaped shapes. The curved portion 42b may be formed only on a portion of the first detection plate 42A. Since the first detection plate 42A is made of an elastically deformable material, the curved portion 42b is elastically deformable in the normal direction D1. Therefore, when pressed from below, the curved portion 42b is displaced upward due to elastic deformation due to upward reaction force. Note that the first detection plate 42A may be composed of a rigid body that does not deform elastically. In this case, the curved portion 42b is not displaced even when pressed from below.

The second detection plate 42B is arranged between the first detection plate 42A and the coating surface PB in the normal direction D1. The second detection plate 42B is supported by the pair of second support grooves 41c while being curved in the normal direction D1 from the lower surface 41a of the insulator 41 toward the coating surface PB. Specifically, both end portions 42c of the second detection plate 42B in the scanning direction D22 are fitted into the pair of second support grooves 41c without gaps. As a result, both ends 42c of the second detection plate 42B are supported and fixed to the pair of second support grooves 41c. A portion between both ends 42c of the second detection plate 42B is a curved portion 42d curved so as to be convex toward the coating surface PB from the both ends 42c in the normal direction D1.

As shown in FIG. 4, the cross-sectional shape of the curved portion 42d of the second detection plate 42B is arcuate so as to protrude from both ends 42c of the second detection plate 42B toward the coating surface PB. The curved portion 42d may be formed only on a portion of the second detection plate 42B. The curved portion 42d is curved, for example, along the curved portion 42b of the first detection plate 42A, and is spaced apart from the curved portion 42b of the first detection plate 42A at a constant interval. The state in which the curved portion 42d is spaced apart from the curved portion 42b by a constant distance means that the distance in the normal direction D1 between the curved portion 42d and the curved portion 42b is set at each position along the scanning direction D22. is maintained constant at Since the second detection plate 42B is made of an elastically deformable material, the curved portion 42d is elastically deformable in the normal direction D1. Therefore, when pressed from below, the curved portion 42d is displaced upward due to elastic deformation due to upward reaction force. As a result, the curved portion 42d is displaced upward from a position separated from the curved portion 42b to a position in contact with the curved portion 42b.

The third detection plate 42C is arranged between the second detection plate 42B and the coating surface PB in the normal direction D1. The third detection plate 42C is supported by the pair of third support grooves 41d while being curved in the normal direction D1 from the lower surface 41a of the insulator 41 toward the coating surface PB. Specifically, both ends of the third detection plate 42C in the scanning direction D22 are fitted into the pair of third support grooves 41d without gaps. As a result, both ends 42e of the third detection plate 42C are supported and fixed to the pair of third support grooves 41d. A portion between both ends 42e of the third detection plate 42C is a curved portion 42f curved so as to be convex toward the coating surface PB from the both ends 42e in the normal direction D1.

As shown in FIG. 4, the cross-sectional shape of the curved portion 42f of the third detection plate 42C is arcuate so as to protrude from both ends 42e of the third detection plate 42C toward the coating surface PB. The curved portion 42f may be formed only on a portion of the third detection plate 42C. The curved portion 42f is curved, for example, along the curved portion 42d of the second detection plate 42B, and is spaced apart from the curved portion 42d at a constant interval. The state in which the curved portion 42f is spaced apart from the curved portion 42d at a constant distance means that the distance in the normal direction D1 between the curved portion 42f and the curved portion 42d is different from each position along the scanning direction D22. is maintained constant at The distance d2 between the curved portion 42f of the third detection plate 42C and the curved portion 42d of the second detection plate 42B is, for example, the distance d3 between the curved portion 42d of the second detection plate 42B and the curved portion 42b of the first detection plate 42A. set to be the same as

Therefore, the first detection plate 42A, the second detection plate 42B, and the third detection plate 42C are vertically spaced apart from each other. Further, the third detection plate 42C is spaced apart from the coating surface PB with a predetermined distance d1 above. Since the third detection plate 42C is made of an elastically deformable material, the curved portion 42f of the third detection plate 42C is elastically deformable in the normal direction D1. Therefore, when pressed from below, the curved portion 42f is displaced upward due to elastic deformation due to upward reaction force. As a result, the curved portion 42f of the third detection plate 42C is displaced upward from a position separated from the curved portion 42d of the second detection plate 42B to a position in contact with the curved portion 42d of the second detection plate 42B.

The distance d1 between the third detection plate 42C and the application surface PB, the distance d2 between the second detection plate 42B and the third detection plate 42C, and the distance d3 between the first detection plate 42A and the second detection plate 42B are the target protrusions. It is set according to the height of the object TP. The intervals d1, d2 and d3 are, for example, set identical to each other. The sum of the distances d2 and d3 is set to the lower limit (for example, 0.1 mm) of the height H1 of the target projection TP within the restorable range. Therefore, as shown in FIG. 5(a), when the abnormality detection unit 40 passes through the target projection TP with the height H1 in the restorable range, the curved portion 42f of the third detection plate 42C does not reach the target projection TP. By colliding and being pushed upward, it is displaced upward while being elastically deformed. As a result, the third detection plate 42C comes into contact with the second detection plate 42B. On the other hand, the second detection plate 42B and the first detection plate 42A are kept separated.

The sum of the intervals d1, d2 and d3 is set to the lower limit value (for example, 1 mm) of the height of the target projection TP with the height H2 of the non-restorable range. Therefore, as shown in FIG. 5(b), when the abnormality detection unit 40 passes through the target projection TP in the non-recoverable range, the curved portion 42f of the third detection plate 42C collides with the target projection TP and moves upward. is pushed upward, it is displaced upward while being elastically deformed. Then, the curved portion 42f of the third detection plate 42C presses the curved portion 42d further upward while contacting the curved portion 42d of the second detection plate 42B. The curved portion 42d of the second detection plate 42B pressed upward is displaced upward while being elastically deformed, and contacts the curved portion 42b of the first detection plate 42A. As a result, the third detection plate 42C, the second detection plate 42B, and the first detection plate 42A come into contact with each other. Note that the intervals d1, d2, and d3 may not be set to be the same. For example, the interval d2 may be set smaller than the interval d3, and the interval d3 may be set smaller than the interval d2.

Please refer to FIG. 4 again. The continuity detection unit 43 detects continuity among the first detection plate 42A, the second detection plate 42B, and the third detection plate 42C. The continuity detection section 43 includes a first continuity detection circuit 46 and a second continuity detection circuit 47 . The first continuity detection circuit 46 is electrically connected to one end 42c of the second detection plate 42B and one end 42e of the third detection plate 42C. The first continuity detection circuit 46 includes a power supply 46a that applies a voltage to the second detection plate 42B and the third detection plate 42C, and a detection sensor 46b that detects continuity between the second detection plate 42B and the third detection plate 42C. ,including. The detection sensor 46b detects electrical connection between the third detection plate 42C and the second detection plate 42B, for example, according to a change in electrical resistance between the third detection plate 42C and the second detection plate 42B. In this case, the detection sensor 46b measures the current value flowing through the third detection plate 42C and the second detection plate 42B with an ammeter, and the current value is applied to the third detection plate 42C and the second detection plate 42B with a voltmeter. Measure the voltage value. Then, the detection sensor 46b calculates an electrical resistance value based on the measured current value and voltage value, and monitors changes in the calculated electrical resistance value.

As shown in FIG. 4, when the third detection plate 42C is separated from the second detection plate 42B, no current flows through the third detection plate 42C and the second detection plate 42B. The electric resistance value with the 2 detection plate 42B becomes infinite. In this case, the detection sensor 46b does not detect conduction between the third detection plate 42C and the second detection plate 42B because the electric resistance value between the third detection plate 42C and the second detection plate 42B does not change from infinity. On the other hand, as shown in FIG. 5A, when current flows through the third detection plate 42C and the second detection plate 42B due to the contact of the third detection plate 42C with the second detection plate 42B, the third detection The electrical resistance value between the plate 42C and the second detection plate 42B changes (decreases). In this case, the detection sensor 46b detects electrical continuity between the third detection plate 42C and the second detection plate 42B when the electric resistance value has decreased from infinity. Then, the detection sensor 46b outputs to the abnormality determination section 44 a first continuity detection signal S4 indicating that there is continuity between the third detection plate 42C and the second detection plate 42B.

As shown in FIG. 4, the second continuity detection circuit 47 is electrically connected to one end 42a of the first detection plate 42A and one end 42c of the second detection plate 42B. The second continuity detection circuit 47 includes a power source 47a that applies a voltage to the first detection plate 42A and the second detection plate 42B, and a detection sensor 47b that detects continuity between the first detection plate 42A and the second detection plate 42B. ,including. The detection sensor 47b detects electrical connection between the second detection plate 42B and the first detection plate 42A, for example, according to a change in electrical resistance between the second detection plate 42B and the first detection plate 42A. In this case, the detection sensor 47b measures the current value flowing through the second detection plate 42B and the first detection plate 42A with an ammeter, and the current value is applied to the second detection plate 42B and the first detection plate 42A with a voltmeter. Measure the voltage value. Then, the detection sensor 47b calculates an electrical resistance value based on the measured current value and voltage value, and monitors changes in the calculated electrical resistance value.

As shown in FIGS. 4 and 5A, when the second detection plate 42B is separated from the first detection plate 42A, no current flows through the second detection plate 42B and the first detection plate 42A. The electric resistance value between the second detection plate 42B and the first detection plate 42A becomes infinite. In this case, the detection sensor 47b does not detect electrical continuity between the second detection plate 42B and the first detection plate 42A because the electrical resistance value between the second detection plate 42B and the first detection plate 42A does not change from infinity. On the other hand, as shown in FIG. 5B, when the current flows through the second detection plate 42B and the first detection plate 42A due to the contact of the second detection plate 42B with the first detection plate 42A, the second detection The electrical resistance value between the plate 42B and the first detection plate 42A changes (decreases). In this case, the detection sensor 47b detects electrical continuity between the second detection plate 42B and the first detection plate 42A when the electrical resistance value has decreased from infinity. Then, the detection sensor 47b outputs to the abnormality determination section 44 a second continuity detection signal S5 indicating that the second detection plate 42B and the first detection plate 42A are electrically connected.

The abnormality determination unit 44 determines the presence or absence of abnormality in the unevenness of the coating surface PB and the degree of abnormality in the unevenness of the coating surface PB according to the detection result of the continuity detection unit 43 . When neither the first continuity detection signal S4 nor the second continuity detection signal S5 is received, the abnormality determination unit 44 determines that the unevenness of the coating surface PB is within the allowable range, and determines that the unevenness of the coating surface PB is within the allowable range. Determine that there is no abnormality. On the other hand, when receiving the first continuity detection signal S4 or both the first continuity detection signal S4 and the second continuity detection signal S5, the abnormality determination unit 44 determines that the unevenness of the coating surface PB is not within the allowable range. Then, it is determined that there is an abnormality in the unevenness of the coating surface PB. In this case, the abnormality determination unit 44 further determines the abnormal state of the unevenness of the coating surface PB, that is, the degree of the size of the target projection TP on the coating surface PB.

When the abnormality determination unit 44 receives only the first continuity detection signal S4, that is, when only the third detection plate 42C and the second detection plate 42B are electrically connected (see FIG. 5A), recovery is possible. It is determined that the target projection TP having the height H1 of the range exists on the coating surface PB. In this case, the abnormality determination section 44 outputs to the operation selection section 52 of the control section 50 a first abnormality detection signal S1 indicating that the unevenness of the application surface PB is in a mildly abnormal state. On the other hand, when the abnormality determination unit 44 receives both the first continuity detection signal S4 and the second continuity detection signal S5, that is, when the third detection plate 42C, the second detection plate 42B, and the first detection plate 42A are all If there is continuity (see FIG. 5(b)), it is determined that the target projection TP having a height H2 within the non-restorable range exists on the coating surface PB. In this case, the abnormality determination section 44 outputs to the operation selection section 52 of the control section 50 a second abnormality detection signal S2 indicating that the unevenness of the coating surface PB is in a severely abnormal state. The abnormality determination unit 44 may be included in the control unit 50 instead of the abnormality detection unit 34 . In this case, the first continuity detection signal S4 and the second continuity detection signal S5 from the continuity detection unit 43 are output to the control unit 50, and the abnormality determination unit 44 of the control unit 50 determines whether the unevenness of the coating surface PB is abnormal. be.

Next, with reference to FIG. 6, the operation performed by the control unit 50 when forming one layer of the modeled object M will be described.

The control unit 50 performs normal modeling processing while rotating the table 6 in the rotation direction D21. At this time, the operation selector 52 selects the normal operation. After forming the powder bed PA on the table 6 by supplying the powder P, the operation control unit 51 causes the heating unit 32 to preheat the powder P (step S11). After that, the powder P enters the area below the irradiation unit 33 while moving in the rotation direction D21 as the table 6 rotates. Next, the operation control unit 51 causes the irradiation unit 33 to execute the molding process of the powder P (step S12). Specifically, the operation control unit 51 irradiates the powder P existing within the irradiation range of the irradiation unit 33 with the electron beam, thereby solidifying the powder P irradiated with the electron beam. The solidified powder P approaches the abnormality detector 34 while moving as the table 6 rotates.

Next, the operation control unit 51 causes the abnormality detection unit 34 to execute abnormality detection processing. That is, the operation control unit 51 causes the abnormality detection unit 34 to detect whether there is an abnormality in the unevenness of the coating surface PB of the powder bed PA (step S13). Specifically, each abnormality detection unit 40 of the abnormality detection section 34 rotates (moves) relative to the coating surface PB in the scanning direction D22 while rotating (moving) the first detection plate 42A, the second detection plate 42B, and the second detection plate 42B. 3 Detects whether or not any one of the detection plates 42C is electrically connected. When the target projection TP does not exist on the application surface PB, none of the abnormality detection units 40 outputs the first abnormality detection signal S1 and the second abnormality detection signal S2 to the operation selector 52 . In this case, the operation selection unit 52 determines that there is no abnormality in the unevenness of the application surface PB (Yes in step S13), and continues to select the normal operation. Then, the operation control unit 51 executes the supply process to the coating surface PB determined to have no abnormality. That is, the operation control unit 51 causes the supply unit 35 to perform the application operation of spreading the application surface PB evenly after supplying the powder P to the application surface PB (step S14). As the table 6 makes one rotation while the operation control unit 51 performs the normal operation, a series of modeling processes for forming one layer of the modeled object M is normally completed.

On the other hand, when the target projection TP exists on the application surface PB, one of the abnormality detection units 40 outputs the first abnormality detection signal S1 or the second abnormality detection signal S2 to the operation selector 52 . In this case, the operation selection unit 52 determines that there is an abnormality in the unevenness of the coating surface PB (No in step S13), and then determines whether or not the abnormality in the unevenness of the coating surface PB can be recovered ( step S15). When the target projection TP having the height H1 within the restorable range exists on the coating surface PB, the third detection plate 42C is pushed upward and comes into contact with the second detection plate 42B, and the third detection plate 42C and the third detection plate 42C are pushed upward. 2 is electrically connected only to the detection plate 42B. In this case, one of the abnormality detection units 40 outputs the first abnormality detection signal S<b>1 to the operation selector 52 . Then, the operation selection unit 52 determines that the unevenness of the application surface PB can be recovered (Yes in step S15), and switches the control contents from the normal operation to the recovery operation. In response to this, the operation control unit 51 interrupts the normal operation and causes the recovery operation to be performed.

Now, with further reference to FIG. 7, the detailed operation of the recovery operation will be described. When executing the recovery operation, the operation control unit 51 first identifies the location of the abnormality on the application surface PB (that is, the position of the target projection TP present on the application surface PB). Specifically, the operation control unit 51 first determines the position of the location of the abnormality in the circumferential direction D2 (step S21). For example, the operation control unit 51 identifies the angular position around the rotation axis C (that is, the position in the circumferential direction D2) of the abnormality detection unit 34 that has output the first abnormality detection signal S1, and determines the identified angular position as the abnormality occurrence location. is determined as the position in the circumferential direction D2. Next, the operation control unit 51 determines the radial position of the location where the abnormality occurred (step S22). The abnormality detection section 34 is composed of a plurality of abnormality detection units 40 separated in the radial direction. Therefore, the operation control unit 51 identifies the abnormality detection unit 40 that has output the first abnormality detection signal S1 among the plurality of abnormality detection units 40, and determines the position of the identified abnormality detection unit 40 as the position of the abnormality occurrence location in the radial direction. Determined as

In this manner, the operation control unit 51 determines the position of the abnormal occurrence location on the coating surface PB. At this time, the operation control unit 51 can also calculate the range of the abnormal occurrence location in the scanning direction D22, that is, the width of the target projection TP in the scanning direction D22. When the abnormality detection unit 40 passes over the target projection TP present on the coating surface PB in the scanning direction D22, the third detection plate 42C contacts the second detection plate 42B at the location where the target projection TP exists. As a result, the third detection plate 42C and the second detection plate 42B are in a conductive state. The third detection plate 42C and the second detection plate 42B are not electrically connected. Therefore, the third detection plate 42C and the second detection plate 42B are electrically connected only while the abnormality detection unit 40 passes over the target projection TP. Therefore, the operation control unit 51 can grasp the width of the target projection TP in the scanning direction D22 from the time during which the third detection plate 42C and the second detection plate 42B are electrically connected. Specifically, the operation control unit 51 determines the width of the target projection TP in the scanning direction D22 from the moving speed of the abnormality detection unit 40 in the scanning direction and the conduction time between the third detection plate 42C and the second detection plate 42B. can be calculated.

Next, the operation control unit 51 changes the molding conditions for the determined abnormal location (step S23). Specifically, the operation control unit 51 changes the conditions for irradiating the electron beam to the target projection TP present on the abnormal occurrence location, ie, the coating surface PB. In this state, the operation control unit 51 repeats a series of modeling processes by preheating control, irradiation control, and supply control, thereby causing a state in which the target projection TP is present on the coating surface PB, i.e., an abnormality on the coating surface PB. Eliminate the situation where there is After that, when the operation control unit 51 ends the restoration operation, the operation selection unit 52 switches the control contents from the restoration operation to the normal operation. In response to this, the operation control unit 51 executes the rest of the interrupted normal operation. That is, as shown in FIG. 6, the operation control unit 51 causes the supply unit 35 to perform the rest of the application operation (step S14), and normally ends the series of processes.

On the other hand, when there is a target projection TP having a height H2 in the non-restorable range on the coating surface PB, the third detection plate 42C is pushed upward together with the second detection plate 42B, and the second sample plate is pushed upwards. It contacts the detection plate 42A, and conducts all of the third detection plate 42C, the second detection plate 42B, and the first detection plate 42A. Therefore, one of the abnormality detection units 40 outputs the second abnormality detection signal S<b>2 to the operation selector 52 . In this case, the operation selection unit 52 determines that the unevenness of the coating surface PB cannot be recovered (No in step S15), and switches the control content from the normal operation to the abnormal stop operation. In response to this, the operation control unit 51 forcibly stops the operation of the driving unit 10 and the modeling processing unit 30, and ends abnormally.

<effect>
Effects obtained by the three-dimensional modeling apparatus 1 and the abnormality detection unit 34 according to the present embodiment described above will be described. In this embodiment, the second detection plate 42B and the third detection plate 42C are arranged in a state in which the first detection plate 42A, the second detection plate 42B, and the third detection plate 42C are arranged side by side in the normal direction D1. Abnormalities in unevenness of the coating surface PB are detected by displacement in the normal direction D1. In this embodiment, all the detection plates 42 are arranged so that the normal direction D1 is the thickness direction, and are curved so as to protrude downward. When the detection plates 42 are arranged in this way, compared with the case where the detection plates 42 are arranged side by side in the scanning direction D22 so as to stand upright with respect to the coating surface PB, the dimensional change of the detection plates 42 due to thermal expansion is reduced. It is possible to reduce the influence of the unevenness of the coating surface PB on the abnormality detection accuracy.

FIG. 8(a) shows the case where the detection plate 142 is supported by the insulator 141 so as to stand upright with respect to the coating surface PB. In this way, when the detection plate 142 is arranged to extend in the normal direction D1, the dimension of the detection plate 142 in the normal direction D1 before thermal expansion is L, and the dimensional change of the detection plate 42 due to thermal expansion is Assuming that ΔL, the dimension in the normal direction D1 of the detection plate 142 after thermal expansion is expressed as (L+ΔL). On the other hand, as shown in FIG. 8B, in the present embodiment, the detection plate 42 is arranged so that the normal direction D1 is the thickness direction, and is curved so as to protrude downward. The example shown in FIG. 8B shows a case where the detection plate 42 is curved in a semicircular shape for the sake of simplicity of explanation. In this case, the dimension of the detection plate 42 before thermal expansion is L, which is the same as the dimension of the detection plate 142, and the dimensional change of the detection plate 42 due to thermal expansion is ΔL. Let R be the radial distance (hereinafter referred to as "radius"), and let ΔR be the change in the radius of the detection plate 42 due to thermal expansion. In this case, when the dimension (L + ΔL) of the detection plate 42 after thermal expansion is converted into the radius (R + ΔR) of the detection plate 42 after expansion, the dimension (L + ΔL) can be expressed as the radius (R + ΔR) x π. Comparing the changes .DELTA.L and .DELTA.R, it can be seen that the change .DELTA.R in the radius is smaller than the dimensional change .DELTA.L by 1/.pi.

In this way, by arranging the detection plate 42 not to stand upright in the normal direction D1 with respect to the application surface PB but to lay it down in the plane direction (that is, so that the detection plate 42 extends in the plane direction), heat can be detected. Even if the dimension of the detection plate 42 changes due to expansion, it is possible to prevent the position of the detection plate 42 from greatly changing in the normal direction D1 with respect to the coating surface PB. Therefore, in this embodiment, the distance between the detection plate 42 and the coating surface PB can be maintained even in a high-temperature environment. This makes it possible to accurately detect the target projection TP. In other words, it is possible to accurately detect irregularities in the unevenness of the coating surface PB.

In the present embodiment, when the continuity detection unit 43 detects continuity among any one of the first detection plate 42A, the second detection plate 42B, and the third detection plate 42C, the abnormality determination unit 44 detects the unevenness of the coating surface PB. is out of the allowable range, and the unevenness of the coating surface PB is determined to be in an abnormal state. As a result, the state in which the first detection plate 42A and the second detection plate 42B are electrically connected can be determined as the state in which the unevenness of the coating surface PB is abnormal.

In this embodiment, the second detection plate 42B is a conductive plate whose thickness direction is the normal direction D1, and has a curved portion 42d that curves toward the coating surface PB in the normal direction D1. In this case, the presence of the curved portion 42d facilitates adjustment of the distance between the second detection plate 42B and the application surface PB, so that the target projection TP can be detected with higher accuracy.

In this embodiment, the curved portion 42d has an arcuate shape that protrudes toward the coating surface PB in a cross section along the normal direction D1 and the scanning direction D22. In this case, when the third detection plate 42C moves relative to the coating surface PB in the scanning direction D22 and collides with the target projection TP, the curved portion 42d of the second detection plate 42B moves through the third detection plate 42C. , the object projection TP receives a reaction force and is easily displaced in the normal direction D1. As a result, when the target projection TP exists on the coating surface PB, the second detection plate 42B can be brought into contact with the first detection plate 42A more reliably. That is, the target projection TP can be detected more reliably.

In this embodiment, the curved portion 42d is configured to elastically deform from a position separated from the first detection plate 42A to a position in contact with the first detection plate 42A. In this case, it is possible to easily realize a configuration in which the second detection plate 42B is displaced from a position separated from the first detection plate 42A to a position in contact with the first detection plate 42A.

In this embodiment, both ends 42c of the second detection plate 42B are supported by the insulator 41, and a portion between the ends 42c of the second detection plate 42B constitutes a curved portion 42d. In this case, it is possible to easily configure the second detection plate 42B having the curved portion 42d while ensuring electrical insulation between the first detection plate 42A and the second detection plate 42B.

In this embodiment, when the third detection plate 42C contacts the second detection plate 42B, the continuity detection unit 43 detects the first detection plate 42C and the second detection plate 42B. A second continuity detection signal S4 is output to indicate that continuity between the second detection plate 42B and the first detection plate 42A is detected when the second detection plate 42B contacts the first detection plate 42A. Output S5. As a result, the height of the target projection TP present on the coating surface PB can be detected in stages according to the state of conduction among the first detection plate 42A, the second detection plate 42B, and the third detection plate 42C. Become.

In the present embodiment, when the continuity detection unit 43 outputs only the first continuity detection signal S4, the abnormality determination unit 44 determines that the unevenness of the coating surface PB is in the first abnormality state, and the continuity detection unit 43 When both the first conduction detection signal S4 and the second conduction detection signal S5 are output, it is determined that the unevenness of the coating surface PB is in the second abnormal state different from the first abnormal state. In this configuration, when the continuity detection unit 43 outputs only the first continuity detection signal S4, the target projection TP having a height not reaching at least the first detection plate 42A exists on the coating surface PB (first abnormal state). On the other hand, when the continuity detection unit 43 outputs both the first continuity detection signal S4 and the second continuity detection signal S5, the target projection TP is higher than when the continuity detection unit 43 outputs only the first continuity detection signal S4. exists on the coating surface PB (second abnormal state). As described above, according to the above-described configuration, the abnormal state of unevenness of the coating surface PB is detected step by step according to the conduction state of the first detection plate 42A, the second detection plate 42B, and the third detection plate 42C. becomes possible.

In this embodiment, the third detection plate 42C is a conductive plate whose thickness direction is the normal direction D1, and has a curved portion 42f that curves toward the coating surface PB in the normal direction D1. As a result, the presence of the curved portion 42f facilitates adjustment of the distance between the third detection plate 42C and the coating surface PB. As a result, it becomes possible to detect the target projection TP with higher accuracy.

In the present embodiment, when the abnormality determination unit 44 determines that the unevenness of the coating surface PB is in the first abnormal state, the operation control unit 51 supplies a recovery operation for eliminating the abnormality of the unevenness of the coating surface PB. If the abnormality determination unit 44 determines that the unevenness of the coating surface PB is in the second abnormal state, the operation of the supply unit 35 and the irradiation unit 33 is stopped. In this way, by taking appropriate measures according to the abnormal state of the unevenness of the coating surface PB, the modeling process can be reliably performed in a normal state.

Although one embodiment of the present disclosure has been described above, the present invention is not limited to the above embodiment.

<Modification 1>
In the abnormality detection unit 40A shown in FIG. 9, the first detection plate 42A, the second detection plate 42B, and the third detection plate 42C are configured by rigid bodies that do not elastically deform. is different from In the abnormality detection unit 40A, the second detection plate 42B and the third detection plate 42C are supported by the insulator 41A so as to be displaceable upward. As shown in FIG. 9, the pair of second support grooves 41e and the pair of third support grooves 41f formed in the lower surface 41a of the insulator 41A are larger than the second support grooves 41c and the third support grooves 41d according to the above embodiment. also extends upwards. When both ends 42c of the second detection plate 42B are supported by the pair of second support grooves 41e, both ends 42c of the second detection plate 42B are separated downward by a predetermined distance from the bottom surfaces of the pair of second support grooves 41e. It is also separated from the inner side surfaces of the pair of second support grooves 41e by a predetermined distance. Similarly, when both ends 42e of the third detection plate 42C are supported by the pair of third support grooves 41f, both ends 42e of the third detection plate 42C extend downward from the bottom surfaces of the pair of third support grooves 41f. It is separated by a predetermined distance, and is also separated by a predetermined distance from the inner side surfaces of the pair of third support grooves 41f. On the other hand, the pair of first support grooves 41b are fitted to both end portions 42a of the first detection plate 42A without gaps, as in the above embodiment.

In this manner, the second detection plate 42B and the third detection plate 42C are configured to be movable upward with respect to the coating surface PB by being displaced upward when pressed from below. Therefore, as shown in FIG. 10(a), when the target projection TP having the height H1 of the restorable range exists on the coating surface PB, the third detection plate 42C collides with the target projection TP. It receives a reaction force from the target projection TP, displaces upward, and contacts the second detection plate 42B. As a result, the third detection plate 42</b>C and the second detection plate 42</b>B are electrically connected, so that the abnormality determination section 44 transmits the first abnormality detection signal S<b>1 to the control section 50 . On the other hand, as shown in FIG. 10(b), when a target projection TP having a height H2 within the non-restorable range exists on the coating surface PB, the third detection plate 42C collides with the target projection TP. It displaces upward and pushes the second detection plate 42B further upward while contacting the second detection plate 42B. As a result, the second detection plate 42B is also displaced upward and comes into contact with the first detection plate 42A. As a result, all of the third detection plate 42C, the second detection plate 42B, and the first detection plate 42A are electrically connected, and the abnormality determination section 44 transmits the second abnormality detection signal S2 to the control section 50. FIG. Therefore, even when the abnormality detection unit 40A shown in FIG. 9 is used, the same effect as the above embodiment can be obtained.

<Modification 2>
An abnormality detection unit 40B shown in FIG. ), and a detection tube 42F (third conductor). The insulator 41B has one support groove 41g instead of the pair of first support grooves 41b, the pair of second support grooves 41c, and the pair of third support grooves 41d. The detection rod 42D is a conductive rod extending linearly in the radial direction. The detection rod 42D is made of a rigid body that is conductive and does not deform elastically. The insulator 41B supports, for example, both radial ends of the detection rod 42D. The detection tube 42E is a cylindrical conductive tube extending linearly in the radial direction. The detection tube 42E is made of a rigid body that is conductive and does not deform elastically. The detection tube 42E has a larger outer diameter than the detection rod 42D and is arranged to accommodate the detection rod 42D. The insulator 41B supports, for example, both radial ends of the detection tube 42E.

The detection tube 42F is a cylindrical conductive tube extending linearly in the radial direction. The detection tube 42F is made of a rigid body that is conductive and does not deform elastically. The detection tube 42F has an outer diameter larger than that of the detection tube 42E and is arranged to accommodate the detection tube 42E. The insulator 41B supports, for example, both radial ends of the detection tube 42F. The support groove 41g of the insulator 41B is a circular groove linearly extending in the radial direction. The support groove 41g has an inner diameter larger than the outer diameter of the detection tube 42F and accommodates the detection tube 42F. The width of the opening of the support groove 41g in the lower surface 41a of the insulator 41B in the scanning direction D22 is smaller than the outer diameter of the detection tube 42F. In such a configuration, downward movement of the detection tube 42F relative to the insulator 41B is restricted, while upward movement of the detection tube 42F relative to the insulator 41B is permitted.

Thus, the detection tube 42E and the detection tube 42F are configured to be displaceable upward when pressed from below. Therefore, as shown in FIG. 12(a), when the target projection TP having the height H1 of the restorable range exists on the application surface PB, the detection tube 42F collides with the target projection TP, thereby It receives a reaction force from the object TP, is displaced upward, and comes into contact with the detection tube 42E. As a result, the detection tube 42</b>F and the detection tube 42</b>E are electrically connected, so that the abnormality determination section 44 transmits the first abnormality detection signal S<b>1 to the control section 50 . On the other hand, as shown in FIG. 12(b), when there is a target projection TP having a height H2 in the non-restorable range on the coating surface PB, the detection tube 42F collides with the target projection TP and moves upward. It displaces and pushes the detection tube 42E further upward while contacting the detection tube 42E. As a result, the detection cylinder 42E is also displaced upward and comes into contact with the detection rod 42D. As a result, since the detection tube 42F, the detection tube 42E, and the detection rod 42D are all electrically connected, the abnormality determination section 44 transmits the second abnormality detection signal S2 to the control section 50. FIG. Therefore, even when the abnormality detection unit 40B shown in FIG. 11 is used, the same effect as the above embodiment can be obtained.

<Other Modifications>
The present disclosure is capable of other various modifications. For example, the above embodiments and modifications may be combined with each other according to the desired purpose and effect. Also, the configuration of the three-dimensional modeling apparatus may be changed as appropriate. For example, the 3D modeling apparatus may model a modeled object using an energy beam other than an electron beam. For example, the three-dimensional modeling apparatus may model a modeled object by irradiating an ion beam, a laser beam, an ultraviolet ray, or the like. In the above embodiment, the abnormality detection unit detects continuity among the first detection plate, the second detection plate, and the third detection plate by detecting changes in the electrical resistance values of these detection plates. It may be performed by detecting a change in current value measured by a meter or a change in voltage value measured by a voltmeter. In the above embodiment, the case where the abnormality detection unit includes the first detection plate, the second detection plate, and the third detection plate has been described, but the third detection plate may not be provided. Alternatively, the abnormality detection section may further include another detection plate between the coating surface and the third detection plate. The scanning direction of the abnormality detection unit with respect to the coating surface does not have to be along the circumferential direction, and may be along the radial direction or other directions along the main surface of the table. good.

1 Three-dimensional modeling device 6 Table 6a Main surface 33 Irradiation unit 34 Abnormality detection unit (abnormality detection device)
35 supply unit 41 insulator (support)
42A first detection plate (first conductor)
42a, 42c, 42e Both ends 42B Second detection plate (second conductor)
42b, 42d, 42f curved portion 42C third detection plate (third conductor)
42D detection rod (first conductor)
42E detection tube (second conductor)
42F detection tube (third conductor)
43 Continuity detection unit 44 Abnormality determination unit 50 Control unit D1 Normal direction D22 Scanning direction M Modeled object P Powder PA Powder bed PB Application surface (surface)

Claims (11)

a supply unit that supplies powder onto the main surface of a table to form a powder bed, which is a layered product of the powder, on the main surface;
an irradiation unit that obtains a three-dimensional modeled object in which the powder is solidified by irradiating the powder bed with an energy beam;
an abnormality detection unit that detects that the unevenness of the surface of the powder bed irradiated with the energy beam is not within an allowable range;
The abnormality detection unit is
a first conductor facing the surface in the normal direction of the main surface;
It is arranged between the surface and the first conductor in the normal direction, and is displaced from a position separated from the first conductor in the normal direction to a position in contact with the first conductor. a configured second electrical conductor;
a continuity detection unit that detects continuity between the first conductor and the second conductor when the second conductor contacts the first conductor in accordance with the force acting in the normal direction; A three-dimensional modeling apparatus. The abnormality detection unit determines that the unevenness of the surface of the powder bed is not within the allowable range when the continuity detection unit detects the continuity between the first conductor and the second conductor, The three-dimensional modeling apparatus according to claim 1, further comprising an abnormality determination unit that determines that the unevenness of the surface is in an abnormal state. The three-dimensional modeling according to claim 1 or 2, wherein the second conductor is a conductive plate having a thickness direction in the normal direction, and has a curved portion curved toward the surface in the normal direction. Device. the first conductor and the second conductor are movable relative to the surface in a scanning direction along the main surface;
4. The three-dimensional modeling apparatus according to claim 3, wherein the curved portion has an arcuate shape that protrudes toward the surface in a cross section along the normal direction and the scanning direction. The three-dimensional modeling apparatus according to claim 3 or 4, wherein the curved portion is configured to elastically deform from a position separated from the first conductor to a position in contact with the first conductor. further comprising an insulating support that supports the first conductor and the second conductor;
6. The device according to any one of claims 3 to 5, wherein both ends of said second conductor are supported by said support, and a portion between said both ends of said second conductor constitutes said curved portion. Three-dimensional modeling device. It is arranged between the surface and the second conductor in the normal direction, and is displaced from a position separated from the second conductor in the normal direction to a position in contact with the second conductor. further comprising a configured third electrical conductor;
The continuity detection unit is
A first indicating that the continuity between the third conductor and the second conductor is detected when the third conductor contacts the second conductor in accordance with the force acting in the normal direction. Outputs a continuity detection signal,
a second conductor indicating that continuity between the second conductor and the first conductor is detected when the second conductor contacts the first conductor in accordance with the force acting in the normal direction; The three-dimensional modeling apparatus according to any one of claims 1 to 6, which outputs a continuity detection signal. When the continuity detection unit detects continuity among any one of the first conductor, the second conductor, and the third conductor, the abnormality detection unit detects that the unevenness of the surface of the powder bed is within an allowable range. It further has an abnormality determination unit that determines that it is not, and determines that the unevenness of the surface of the powder bed is in an abnormal state,
The abnormality determination unit determines that the unevenness of the surface of the powder bed is in the first abnormal state when the continuity detection unit outputs only the first continuity detection signal, and the continuity detection unit detects the first The tertiary according to claim 7, wherein when both the continuity detection signal and the second continuity detection signal are output, it is determined that the unevenness of the surface of the powder bed is in a second abnormal state different from the first abnormal state. Former sculpting device. The three-dimensional modeling according to claim 7 or 8, wherein the third conductor is a conductive plate having a thickness direction in the normal direction, and has a curved portion curved toward the surface in the normal direction. Device. further comprising a control unit that controls operations of the supply unit and the irradiation unit;
When the abnormality determination unit determines that the unevenness of the surface is in the first abnormal state, the control unit causes the supply unit and the irradiation unit to perform a recovery operation to eliminate the abnormality of the unevenness of the surface. The three-dimensional modeling apparatus according to claim 8, wherein the operation of the supply unit and the irradiation unit is stopped when the abnormality determination unit determines that the unevenness of the surface is in the second abnormal state. An abnormality detection device for detecting that unevenness of the surface of the powder bed irradiated with the energy beam on the main surface of the table is not within the allowable range,
a first conductor facing the surface in the normal direction of the main surface;
It is arranged between the surface and the first conductor in the normal direction, and is displaced from a position separated from the first conductor in the normal direction to a position in contact with the first conductor. a configured second electrical conductor;
a continuity detection unit that detects continuity between the first conductor and the second conductor when the second conductor contacts the first conductor in accordance with the force acting in the normal direction; An anomaly detection device.

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