JP7574724B2 - 3D modeling equipment - Google Patents

Description

This disclosure relates to a three-dimensional modeling device.

Conventionally, there is an apparatus that manufactures three-dimensional products (models) by arranging raw powder material in layers on a work table (modeling plate) and irradiating selected parts of the powder layer with an electron beam to melt them in sequence (see, for example, Patent Document 1). In such an apparatus for manufacturing three-dimensional products, selected parts of one powder layer are melted, and after the molten powder has hardened, selected parts of another powder layer formed on top are melted and hardened. In this way, three-dimensional products are manufactured by repeating melting (hardening) and stacking.

International Publication No. 2017/081812

In a three-dimensional modeling device, a model can be produced while preheating the stacked powder layers. In this case, for example, the heat input to the part of the powder layer that corresponds to the model can be greater than the heat input to other parts, causing the temperature distribution on the modeling plate to become non-uniform. This can cause distortion in the modeling plate, making it difficult to perform proper modeling.

One aspect of the present disclosure aims to provide a three-dimensional printing device that can suppress the occurrence of distortion in a printing plate.

A three-dimensional modeling apparatus according to one embodiment of the present disclosure includes a plate that supports a powder material and a model made of the powder material, a beam irradiation unit that irradiates a beam onto the powder material placed on the plate to preheat the powder material, a status sensor that measures the strain distribution of the plate, and a control device that identifies a strain position in the plate where strain is occurring based on the strain distribution measured by the status sensor and controls the amount of heat input for preheating by the beam irradiation unit so as to reduce the strain at the identified strain position.

The above-mentioned three-dimensional modeling device has a status sensor that measures the distortion distribution of the plate. Therefore, when distortion occurs in the plate due to irradiation with a beam during the modeling process of the model, the position of the distortion is identified based on the distortion distribution. When preheating the powder material, the heat input of the preheating is controlled so that distortion at the distortion position is reduced, thereby suppressing distortion in the plate.

An example of the condition sensor may be an optical fiber sensor. In this configuration, the strain distribution of the plate can be obtained using a small number of condition sensors (e.g., one).

In one example, the optical fiber sensor may be arranged in a spiral shape on the plate when viewed in a plan view. In this configuration, the optical fiber can be easily laid out within the surface of the plate.

In one example, the optical fiber sensors may be arranged in a grid pattern on the plate when viewed in a plan view. In this configuration, the optical fibers can be easily laid out across the surface of the plate.

As an example, the optical fiber sensor may be arranged back and forth on the plate when viewed in a plan view. In this configuration, the optical fiber can be easily laid out within the surface of the plate.

An example of a condition sensor may measure the temperature distribution of the plate in addition to measuring the strain distribution. In this configuration, for example, temperature data at the strain position can be obtained.

When it is determined that no distortion has occurred in the plate based on the distortion distribution measured by the state sensor, the control device in one example may control the amount of heat input for preheating by the beam irradiation unit so that the temperature of the plate becomes uniform based on the temperature distribution. In this configuration, distortion of the plate caused by non-uniformity in the temperature of the plate is suppressed.

According to one embodiment of the present disclosure, a three-dimensional printing device is provided that can suppress the occurrence of distortion in a printing plate.

FIG. 1 is a vertical cross-sectional view showing an example of a three-dimensional modeling apparatus. FIG. 2 is a schematic plan view of an example of a shaping plate viewed from below. FIG. 2 is a block diagram showing a control system of an example of a three-dimensional printing apparatus. FIG. 11 is a flow chart illustrating an example of an operation of heat input control in the three-dimensional modeling apparatus. 13 is a schematic plan view of another example of a shaping plate as viewed from below. FIG. 13 is a schematic plan view of still another example of a shaping plate as viewed from below. FIG. 13 is a schematic plan view of still another example of a shaping plate as viewed from below. FIG.

Embodiments of the present disclosure will be described in detail below with reference to the drawings. Note that the same or equivalent parts in each drawing are given the same reference numerals, and duplicated explanations will be omitted.

The three-dimensional modeling device shown in FIG. 1 is a so-called 3D (three-dimensional) printer. In the following description, the three-dimensional modeling device is simply referred to as a "modeling device." The modeling device 1 repeats a process of preheating the powder material 2 by irradiating the powder material 2 with an electron beam, and a process of melting the powder material 2 by irradiating the powder material 2 with an electron beam to model a part of an object, and stacks the solidified powder material to model an object. Preheating is a process of heating the powder material 2 at a temperature below the melting point of the powder material 2 before modeling an object. This preheating heats and provisionally sinters the powder material 2, suppresses the accumulation of negative charges in the powder material 2 due to the irradiation of the electron beam, and suppresses the smoke phenomenon in which the powder material 2 scatters and rises when the electron beam is irradiated. In the following description, preheating may be referred to as preheating.

The molded object 3 is, for example, a machine part. The molded object 3 may be other structures. The powder material 2 may be metal powder such as titanium-based metal powder, Inconel (registered trademark) powder, aluminum powder, stainless steel powder, etc. The powder material of the molded object 3 is not limited to metal powder. The powder material may contain carbon fiber and resin, such as CFRP (Carbon Fiber Reinforced Plastics). The powder material may also contain other materials. For example, the powder material may contain a conductive material having electrical conductivity.

The modeling apparatus 1 includes a vacuum chamber 4, a work table 5, a lifting device 6, a powder supplying device 7, an electron beam irradiation device 8 (beam irradiation section), a modeling tank 10, and a control device 18. The vacuum chamber 4 is a container capable of creating a vacuum (low pressure) state inside. A vacuum pump (not shown) is connected to the vacuum chamber 4. The shape of the work table 5 is, for example, a plate shape. The shape of the work table 5 is, for example, a circle in a plan view. The shape of the work table 5 is not limited to a circle. The shape of the work table 5 may be a rectangle. The shape of the work table 5 may also be another shape.

A shaping plate 15 is placed on the working table 5. A powder material 2, which is the material of the shaping object 3, is placed on the shaping plate 15. The powder material 2 on the shaping plate 15 is placed, for example, in layers in multiple batches. FIG. 2 is a plan view showing a schematic bottom surface of the shaping plate 15. An example of the shaping plate 15 has a plate shape having an approximately circular shape in a plan view. For example, the shaping plate 15 may be a metal plate member, and may be stainless steel (e.g., SUS304) as an example. The thickness of the shaping plate 15 in the Z direction is not particularly limited, but may be about 10 mm as an example. The shaping plate 15 is provided with an optical fiber sensor 16 (status sensor). The optical fiber sensor 16 is a status sensor that measures the temperature distribution of the shaping plate 15 and the strain distribution of the shaping plate 15.

An example of the optical fiber sensor 16 includes an optical fiber 16a connected to a measuring instrument 17. For example, in the optical fiber sensor 16, input light is input from a light source included in the measuring instrument 17 to the optical fiber 16a. At each position in the longitudinal direction of the optical fiber 16a, Rayleigh scattered light is generated by the input light. The Rayleigh scattered light is reflected and input to the measuring instrument 17. The measuring instrument 17 derives the temperature and the amount of strain at each position in the longitudinal direction of the optical fiber 16a by analyzing the acquired Rayleigh scattered light. In one example, optical frequency domain reflectometry (OFDR) may be used to analyze the reflected light. The measuring instrument 17 outputs the derived temperature and amount of strain to the control device 18. The amount of strain may be a ratio of the change in the length of the optical fiber. The amount of strain may be derived as a positive value when the change in the length of the optical fiber is positive (distortion due to expansion), and may be derived as a negative value when the change in the length of the optical fiber is negative (distortion due to contraction).

The optical fiber 16a is fixed to the lower surface of the shaping plate 15. As shown in FIG. 2, the optical fiber 16a is laid out within the surface of the shaping plate 15 in a plan view. For example, when the lower surface of the shaping plate 15 is virtually divided into a plurality of analysis regions at substantially equal intervals, the optical fiber sensor 16 is fixed to the lower surface so as to pass through all the analysis regions. In one example, the optical fiber 16a is arranged in a spiral shape on the lower surface of the shaping plate 15. Arranged in a spiral shape means that the optical fiber 16a is arranged so that the distance to the center becomes gradually or stepwise smaller from the outer periphery toward the center, or the distance from the center becomes gradually or stepwise larger from the center toward the outer periphery. In the illustrated example, the optical fiber 16a is arranged in a spiral shape curved from the outer periphery toward the center of the shaping plate 15 so that the interval between adjacent optical fibers 16a in the radial direction is the same at any position. For example, when the analysis region is a square, the length of one side of the analysis region may be the same as the interval between adjacent optical fibers in the radial direction. If you want to increase the resolution, i.e., if you want to reduce the analysis area, the optical fibers 16a are arranged densely.

The working table 5 and the modeling plate 15 are disposed in the modeling tank 10 within the vacuum chamber 4. In the modeling tank 10, the working table 5 can move in the Z direction (up and down). The working table 5 descends sequentially according to the number of layers of the powder material 2. The side wall 10a of the modeling tank 10 guides the movement of the working table 5. The shape of the side wall 10a corresponds to the outer shape of the working table 5. For example, when the shape of the working table 5 is a disk shape, the shape of the side wall 10a may be a cylindrical shape. Also, when the shape of the working table 5 is a rectangle, the shape of the side wall 10a may be a square tube shape. The side wall 10a of the modeling tank 10 and the working table 5 form a storage section that stores the powder material 2 and the modeled object 3. The working table 5 may constitute the bottom of the modeling tank 10.

The lifting device 6 lifts and lowers the work table 5. When the lifting device 6 lifts and lowers the work table 5, the modeling plate 15 on the work table 5, the powder material 2 on the modeling plate 15, and the model 3 are lifted and lowered. The lifting device 6 includes, for example, a rack-and-pinion type drive mechanism. With these mechanisms, the lifting device 6 moves the work table 5 in the Z direction. The lifting device 6 includes a vertical member 6a (rack) and a drive source 6b. The vertical member 6a is a rod-shaped member that is connected to the back surface of the work table 5 and extends downward. The drive source 6b drives the vertical member 6a. For example, an electric motor may be used as the drive source 6b. A pinion is provided on the output shaft of the electric motor. A tooth profile that meshes with the pinion is provided on the side of the vertical member 6a. When the electric motor is driven, the pinion rotates. Power is transmitted by the rotation of this pinion. As a result, the vertical member 6a moves in the vertical direction. When the rotation of the electric motor is stopped, the vertical member 6a is positioned. As a result, the position of the work table 5 in the Z direction is determined, and the position of the work table 5 is maintained. The lifting device 6 is not limited to a rack-and-pinion type drive mechanism. For example, the lifting device 6 may be equipped with other drive mechanisms such as a ball screw, a cylinder, etc.

The powder supplying device 7 includes a raw material tank 11. The raw material tank 11 is a storage section that stores the raw material powder material 2. The raw material tank 11 is disposed within the vacuum chamber 4. The raw material tank 11 is disposed above the work table 5 in the Z direction. The raw material tank 11 is disposed, for example, on both sides of the electron beam irradiation area D of the electron beam irradiation device 8 in the X direction that intersects with the Z direction. An outlet is provided at the bottom of the raw material tank 11. The outlet is continuous in, for example, the Y direction. The Y direction is a direction that intersects with the X direction and the Z direction.

Below the raw material tank 11, an extension plate 12 is provided, which extends laterally from the upper end of the side wall 10a of the modeling tank 10. The extension plate 12 forms a plane that intersects with the Z direction around the work table 5, i.e., a plane that runs along the X direction and the Y direction.

The powder supplying device 7 includes a recoater 7a, which is a powder application mechanism that levels the powder material 2. The recoater 7a can move in the X direction above the work table 5 and the extension plate 12. By this movement, the recoater 7a scrapes the powder material 2 deposited on the extension plate 12 onto the work table 5. Furthermore, by this movement, the recoater 7a levels the surface 2a (upper surface) of the top layer of the stack of powder material 2 on the work table 5. Hereinafter, the "stack of powder material 2" is referred to as the powder bed A. The recoater 7a abuts against the surface 2a of the powder bed A to make the height of the powder bed A uniform. The recoater 7a has a predetermined width in the Y direction. The length of the powder application mechanism in the Y direction corresponds to, for example, the total length of the work table 5 in the Y direction. The powder supplying device 7 may include, for example, a rack-and-pinion type drive mechanism as a mechanism for moving the recoater 7a along the horizontal direction.

The electron beam irradiation device 8 includes an electron gun (not shown) that irradiates an electron beam (electron beam) as an energy beam. In FIG. 1, an irradiation region D through which the emitted electron beam passes is indicated by a two-dot chain line. The electron beam emitted from the electron gun is irradiated into the vacuum chamber 4. The electron beam heats the powder material 2. In other words, the electron beam irradiation device 8 imparts energy to the powder material 2.

The electron beam irradiation device 8 may include a coil device that controls the irradiation of the electron beam. The coil device includes, for example, an aberration coil, a focus coil, and a deflection coil. The aberration coil is installed around the electron beam emitted from the electron gun and converges the electron beam. The focus coil is installed around the electron beam emitted from the electron gun and corrects the deviation of the focus position of the electron beam. The deflection coil is installed around the electron beam emitted from the electron gun and adjusts the irradiation position of the electron beam. The deflection coil performs electromagnetic beam deflection. With electromagnetic beam deflection, the scanning speed during irradiation of the electron beam is faster than with mechanical beam deflection. The electron gun and the coil unit are arranged at the top of the vacuum chamber 4. The electron beam emitted from the electron gun is converged by the coil unit, the focus position is corrected, the scanning speed is controlled, and the electron beam reaches the irradiation position of the powder material 2.

The control device 18 controls the operation of the molding device 1. The control device 18 is a computer including hardware such as a CPU (Central Processing Unit), a ROM (Read Only Memory), and a RAM (Random Access Memory), and software such as a program stored in the ROM. The control device 18 includes an input signal circuit, an output signal circuit, a power supply circuit, etc. Each function of the control device 18 is realized by operating the input/output unit under the control of the CPU and reading and writing data. There are no particular limitations on the form and location of the control device 18.

Figure 3 is a block diagram for explaining a control device of an example three-dimensional modeling device. As shown in Figure 3, the control device 18 is electrically connected to the electron beam irradiation device 8, the powder supply device 7, the lifting device 6, and the measuring instrument 17. The control device 18 also includes, as functional units, a drive control unit 18a, a powder supply control unit 18b, and an irradiation control unit 18c.

The drive control unit 18a outputs a control signal to the lifting device 6 and controls the lifting and lowering of the work table 5 through the operation of the lifting device 6. For example, the drive control unit 18a positions the work table 5 at the top of the modeling tank 10 at the beginning of modeling, and lowers the work table 5 as the modeling of the model 3 progresses.

The powder supply control unit 18b outputs a control signal to the powder supply device 7 to control the supply of the powder material 2. For example, the powder supply control unit 18b controls the raw material tank 11 so that a constant amount of powder material 2 is supplied to the top surface of the work table 5. The powder supply control unit 18b also controls the operation of the recoater 7a so that the surface layer of the powder material 2 on the work table 5 is spread evenly.

The irradiation control unit 18c outputs a control signal to the electron beam irradiation device 8 and controls the emission of the electron beam. In one example, the irradiation control unit 18c controls the electron beam irradiation device 8 so that the electron beam is irradiated to a set irradiation position. For example, the irradiation control unit 18c controls an aberration coil to converge the electron beam. The irradiation control unit 18c controls a focus coil to control the focus position of the electron beam. The irradiation control unit 18c controls a deflection coil to control the irradiation position (irradiation direction) of the electron beam.

In one example, the irradiation control unit 18c outputs a control signal to the electron beam irradiation device 8 so that the object 3 is shaped and the powder material 2 is preheated by irradiating the electron beam. The irradiation position of the electron beam for shaping the object 3 can be set based on slice data of a cross section of the object 3. In one example, the slice data of the object 3 can be acquired based on three-dimensional computer-aided design (CAD) data of the object 3. For example, multiple slice data can be acquired according to the upper and lower positions of the object 3. One layer of slice data corresponds to one layer of the powder material 2. The object 3 is shaped by irradiating the electron beam to the irradiation position set based on the slice data.

In addition, to preheat the powder material 2, the irradiation control unit 18c controls the amount of preheating heat input by the electron beam irradiation device 8 to the powder material 2 placed on the modeling plate 15 for each irradiation position. In one example, the irradiation control unit 18c controls the amount of preheating heat input based on the temperature distribution of the modeling plate 15 measured by the optical fiber sensor 16 and the strain distribution of the modeling plate 15 measured by the optical fiber sensor 16.

For example, the irradiation control unit 18c acquires the temperature data and the strain amount data derived by the measuring instrument 17. In one example, the temperature data and the strain amount data are data corresponding to the longitudinal position of the optical fiber 16a in the optical fiber sensor 16. The irradiation control unit 18c then acquires the temperature distribution and the strain amount distribution on the shaping plate 15 based on the temperature data and the strain amount data. The temperature distribution may be temperature data for each position on the shaping plate 15, and the strain amount distribution may be strain amount data for each position on the shaping plate 15. For example, the irradiation control unit 18c may derive the temperature distribution and the strain amount distribution on the shaping plate 15 by referring to data indicating the correspondence between the longitudinal position of the optical fiber sensor and the position on the shaping plate 15.

The irradiation control unit 18c determines whether or not distortion has occurred in the modeling plate 15 based on the acquired distortion distribution data. For example, the irradiation control unit 18c compares the distortion distribution data with a predetermined threshold value, and determines that distortion has occurred in the modeling plate 15 when a distortion amount equal to or greater than the threshold value is measured.

The irradiation control unit 18c identifies the position where distortion occurs (hereinafter, sometimes referred to as the distortion position). For example, the irradiation control unit 18c may compare the data of the distortion amount distribution with a predetermined threshold value, and identify the position in the forming plate 15 where the distortion amount equal to or greater than the threshold value is measured as the distortion position.

The irradiation control unit 18c may execute a heat input correction calculation. The heat input correction calculation may be a calculation for deriving the amount of heat input for each irradiation position, which is necessary to make the temperature distribution in the modeling plate 15 uniform. For example, the irradiation control unit 18c may have data indicating the correspondence between the amount of heat input by the electron beam and the rising temperature of the powder material. Based on the correspondence between the amount of heat input and the rising temperature, the irradiation control unit 18c calculates the amount of heat input based on the temperature distribution before preheating so that the temperature distribution of the modeling plate 15 approaches a uniform state after preheating. For example, the amount of heat input at a position with a high temperature is smaller than the amount of heat input at a position with a low temperature. The amount of heat input may be calculated as the irradiation time of the electron beam.

The irradiation control unit 18c may execute a distortion correction calculation. The distortion correction calculation may be a calculation for deriving the amount of heat input for each irradiation position, which is necessary to uniformize the distribution of the amount of distortion in the shaping plate 15. For example, the irradiation control unit 18c may have data indicating the correspondence between the amount of distortion and the amount of heat input for reducing the amount of distortion. In one example, the amount of heat input for reducing the amount of positive distortion may be set smaller than the amount of heat input that serves as the reference in normal preheating, and the amount of heat input for reducing the amount of negative distortion may be set larger than the amount of heat input that serves as the reference in normal preheating. The irradiation control unit 18c calculates the amount of heat input at the distortion position based on the correspondence between the amount of distortion and the amount of heat input. The amount of heat input that serves as the reference in normal preheating may be arbitrarily determined depending on the components of the powder material. For example, the amount of heat input that serves as the reference in normal preheating may be a predetermined temperature that is lower than the melting point of the powder material.

The irradiation control unit 18c may generate a preheating irradiation path. The preheating irradiation path may be data indicating the amount of heat input in the preheating operation at each irradiation position in the shaping plate 15. The irradiation control unit 18c derives the amount of heat input at each irradiation position in the entire shaping plate 15, including the distortion position, based on the result of the heat input correction calculation or the distortion correction calculation. The irradiation control unit 18c controls the electron beam irradiation device 8 so that preheating is performed according to the generated preheating irradiation path. In other words, the irradiation position and energy of the electron beam irradiated by the electron beam irradiation device 8 are determined by the preheating irradiation path.

Figure 4 is a flow diagram showing an example of the preheating operation of the modeling device 1. When the preheating operation is performed, first, the irradiation control unit 18c of the control device 18 acquires sensor information from the optical fiber sensor 16 (step S1). That is, based on the temperature data and the distortion data acquired from the measuring instrument 17, the irradiation control unit 18c derives a temperature distribution indicating the temperature at each position in the modeling plate 15 and a distortion distribution indicating the distortion at each position in the modeling plate 15.

Then, the irradiation control unit 18c judges whether or not distortion has occurred in the shaping plate 15 (step S2). This judgment is made based on the distortion amount distribution acquired in step S1. If it is judged in step S2 that distortion has not occurred, the irradiation control unit 18c judges whether or not the temperature in the shaping plate 15 is uniform (step S3). This judgment is made based on the temperature distribution acquired in step S1. If it is judged in step S3 that the temperature is uniform, the irradiation control unit 18c generates a preheating irradiation path so that the heat input amount is the same for each position on the shaping plate 15 (step S6). The irradiation control unit 18c controls the irradiation of the electron beam by the electron beam irradiation device 8 so that preheating is performed according to the preheating irradiation path (step S7).

If it is determined in step S3 that the temperature is not uniform, the irradiation control unit 18c identifies the distortion position and performs a heat input correction calculation (step S4). That is, the irradiation control unit 18c calculates the amount of heat input for each position on the shaping plate 15 so that the temperature distribution of the shaping plate 15 after preheating approaches uniformity. The irradiation control unit 18c generates a preheating irradiation path based on the result of the heat input correction calculation (step S6). The irradiation control unit 18c controls the irradiation of the electron beam by the electron beam irradiation device 8 so that preheating is performed according to the preheating irradiation path (step S7).

If it is determined in step S2 that distortion has occurred, the irradiation control unit 18c performs a distortion correction calculation (step S5). That is, the irradiation control unit 18c calculates the heat input amount for each position on the shaping plate 15 so that the distortion amount distribution of the shaping plate 15 after preheating approaches uniformity. The irradiation control unit 18c generates a preheating irradiation path based on the result of the distortion correction calculation (step S6). The irradiation control unit 18c controls the irradiation of the electron beam by the electron beam irradiation device 8 so that preheating is performed according to the preheating irradiation path (step S7).

As described above, the three-dimensional modeling device 1 includes a modeling plate 15 that supports the powder material 2, an electron beam irradiation device 8 that irradiates the powder material 2 arranged on the modeling plate 15 with an electron beam to preheat the powder material 2, an optical fiber sensor 16 (status sensor) that measures the strain distribution of the modeling plate 15, and a control device 18 that identifies the strain position where the strain is occurring within the modeling plate 15 based on the strain distribution measured by the optical fiber sensor 16, and controls the heat input of the preheating by the electron beam irradiation device 8 so as to reduce the strain at the identified strain position.

In the above-mentioned three-dimensional modeling device 1, in the modeling process of the model 3, the powder material 2 is irradiated with an electron beam for preheating, and the electron beam is irradiated to a predetermined position according to the shape of the model 3 for melting or sintering. In this way, since the heat input amount of the electron beam differs depending on the position on the modeling plate 15, the temperature distribution of the modeling plate 15 becomes non-uniform, and it is considered that distortion occurs in the modeling plate 15. One example of the three-dimensional modeling device 1 has an optical fiber sensor 16 that measures the distortion amount distribution of the modeling plate 15. Therefore, when distortion occurs in the modeling plate 15, the distortion position is identified based on the distortion amount distribution. When preheating the powder material 2, the heat input amount of preheating is controlled so that the distortion at the distortion position is reduced, so that distortion in the modeling plate 15 can be suppressed.

In one example, the strain distribution is acquired by the optical fiber sensor 16. In this manner, in a configuration in which the strain distribution is acquired by the optical fiber sensor, the strain distribution of the shaping plate 15 can be acquired by a small number of sensors (e.g., one).

In one example, the optical fiber sensor 16 is arranged in a spiral shape on the shaping plate 15 when viewed in a plane. In this configuration, the optical fiber 16a can be easily laid out within the surface of the shaping plate 15.

The optical fiber sensor 16, in one example, measures the strain distribution and also measures the temperature distribution of the shaping plate 15. In this configuration, for example, temperature data at the strain position can be acquired. In addition, in this configuration, the amount of heat input for preheating can be controlled based on the temperature distribution. That is, when the control device 18, in one example, determines that no distortion has occurred in the shaping plate 15 based on the strain distribution measured by the optical fiber sensor 16, it can control the amount of heat input for preheating by the electron beam irradiation device 8 based on the temperature distribution so that the temperature of the shaping plate 15 becomes uniform. In this configuration, the occurrence of distortion in the shaping plate 15 due to the temperature of the shaping plate 15 becoming non-uniform is suppressed.

This disclosure is not limited to the above-described embodiments, and various modifications are possible without departing from the spirit and scope of the present invention.

For example, FIG. 5 is a schematic plan view of another example of a shaping plate viewed from below. As shown in FIG. 5, the optical fiber 16a may be arranged in a reciprocating manner on the underside of the disk-shaped shaping plate 15. The reciprocating arrangement includes an outward arrangement and a return arrangement in which the directions toward the tip are opposite to each other, and is an arrangement in which the outward arrangement and the return arrangement are formed alternately. In a configuration in which the optical fiber 16a is arranged in a reciprocating manner, the optical fiber 16a can be easily laid out within the surface of the shaping plate 15.

Figures 6 and 7 are schematic plan views of another example of a shaping plate viewed from below. As shown in Figure 6, the optical fibers 16a may be arranged in a spiral pattern on the lower surface of the rectangular shaping plate 15. As shown in Figure 7, the optical fibers 16a may be arranged in a lattice pattern on the lower surface of the rectangular shaping plate 15. The lattice pattern is formed by two mutually orthogonal reciprocating arrangements, and a lattice pattern is formed by the optical fibers 16a that are laid out. In a configuration in which the optical fibers 16a are arranged in a lattice pattern, the optical fibers 16a can be easily laid out within the surface of the shaping plate 15.

The three-dimensional printing device may also perform preheating of the powder material using an external heat source such as a heater. In this case, multiple heaters may be provided so that the amount of heat input from preheating can be changed for each position on the printing plate.

The shaping plate may also be formed as a hollow plate. In this case, the optical fiber constituting the optical fiber sensor may be disposed within the inner space of the shaping plate.

The strain distribution and temperature distribution may also be obtained by a condition sensor other than an optical fiber sensor. For example, the temperature distribution and strain distribution of the build plate may be obtained by attaching multiple thermocouples and multiple strain gauges to the build plate.

1 Modeling device (dimensional modeling device)
2 Powder material 3 Model 8 Electron beam irradiation device (beam irradiation section)
18 Control device 15 Modeling plate 16 Optical fiber sensor 17 Measuring instrument 16a Optical fiber

Claims (7)

A plate for supporting a powder material and a model made of the powder material;
a beam irradiation unit that irradiates a beam onto the powder material arranged on the plate to heat and melt the powder material, and that irradiates the beam onto the powder material on the plate to perform preheating to heat the powder material to a temperature below the melting point of the powder material before performing the heating to melt the powder material;
A state sensor that measures a strain distribution of the plate;
a control device that identifies a distortion position where distortion is occurring within the plate based on the distortion amount distribution measured by the state sensor, and controls the heat input of pre-heating by the beam irradiation unit so as to reduce distortion at the identified distortion position. The three-dimensional printing device according to claim 1, wherein the status sensor is an optical fiber sensor. The three-dimensional printing device according to claim 2, wherein the optical fiber sensor is arranged in a spiral shape on the plate in a plan view. The three-dimensional printing device according to claim 2, wherein the optical fiber sensors are arranged in a grid pattern on the plate in a plan view. The three-dimensional printing device according to claim 2, wherein the optical fiber sensor is arranged to reciprocate on the plate in a plan view. The three-dimensional printing device according to any one of claims 1 to 5, wherein the state sensor measures the strain distribution and the temperature distribution of the plate. The three-dimensional printing device according to claim 6, wherein the control device controls the amount of heat input for preheating by the beam irradiation unit so that the temperature of the plate becomes uniform based on the temperature distribution when it is determined that no distortion has occurred in the plate based on the distortion amount distribution measured by the state sensor.

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