Lamination molding apparatus

A lamination molding apparatus including: an irradiator irradiating a material layer with a beam to form a solidified layer; and a temperature adjustment device which abuts against a part or all of the solidified body including an upper surface of the solidified body, and heats and cools the part or all of the solidified body to a set temperature. The temperature adjustment device has a temperature adjustment plate and a revolving portion. The revolving portion sets the temperature adjustment plate to an upright state when the part or all of the solidified body including the upper surface of the solidified body is not heated and cooled by the temperature adjustment device, and sets the temperature adjustment plate to a lying state when the part or all of the solidified body including the upper surface of the solidified body is heated and cooled by the temperature adjustment device.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims the priority benefit of Japan application serial no. 2020-096084, filed on Jun. 2, 2020. The entirety of the above-mentioned patent application is hereby incorporated by reference herein and made a part of this specification.

BACKGROUND

Technical Field

The disclosure relates to a lamination molding apparatus of a three-dimensional molded object.

Related Art

There are a plurality of methods for metal laminate molding, and for example, with respect to a sintering laminate molding method, in a closed chamber filled with an inert gas, a material powder made of a metal material is laminated on a molding table that can be moved in an up-down direction, and a laser light or an electron beam is irradiated to a predetermined section of the laminated material layer to melt or sinter the material powder at the irradiation position, and thereby a plurality of solidified layers are formed. The plurality of solidified layers are laminated, and a desired three-dimensional molded object is formed. Here, the solidified layer includes a melted layer and a sinter layer. In addition, the laminated solidified layer is referred to as a solidified body.

In this metal laminate molding, temperature adjustment may be performed on the three-dimensional molded object after molding or the solidified layer during molding. For example, in Patent literature 1 (Japanese Patent No. 6295001) and Patent literature 2 (Japanese Patent Application No. 2018-234241), disclosed is an invention relating to a lamination molding apparatus and a manufacturing method of a three-dimensional molded object which can suppress deformation of the molded object by reducing a tension stress due to metal contraction by a compression stress due to martensitic transformation and controlling a residual stress of the molded object in a manner of intentionally progressing the martensitic transformation each time one or more solidified layers are formed. Here, in order to intentionally progress the martensitic transformation, adjustment to a predetermined temperature is performed on the solidified layers each time the one or more solidified layers are formed.

However, when the laminate molding method as described in Patent literature 1 is performed, the solidified layer is cooled and heated. Conventionally, the temperature adjustment of the solidified layer is performed by a temperature adjustment mechanism arranged in the molding table, and thus it is necessary to cool and heat the entire laminated solidified body each time the one or more solidified layers are formed. When this temperature adjustment method is performed, there is a problem that the temperature adjustment takes a long time, and a cooling waiting time is not fixed because a temperature response time of an upper surface of the solidified body differs according to the height of the solidified body.

The problem in the temperature adjustment mechanism arranged in the molding table can be expected to be solved by a temperature adjustment method in which a temperature adjustment device is arranged in a machining head and a cooling plate is closely attached to the upper surface of the laminated solidified body as in Patent literature 2.

Meanwhile, it is known that the progress of the martensitic transformation can be further promoted not only by cooling but also by heating the upper surface of the laminated solidified body. Therefore, a simple mechanism is desired which is capable of not only cooling but also heating the upper surface of the solidified body without interfering with other steps and is capable of switching from heating to cooling in a shorter time.

In addition, strictly, a parallelism of the upper surface of the solidified body is different for each layer, and thus if the cooling plate is merely revolved from an upright state to a lying state and arranged on the upper surface of the solidified body, there is a possibility that the cooling plate does not properly abut against the upper surface of the solidified body and only contacts a part of the upper surface of the solidified body, and the upper surface of the solidified body cannot be uniformly and evenly cooled. In this way, even when the parallelism of the solidified body is poor, if the upper surface of the solidified body can be cooled uniformly and evenly, the upper surface of the solidified body can be heated and cooled more efficiently.

The disclosure provides a lamination molding apparatus of a three-dimensional molded object capable of quickly and uniformly heating and cooling the upper surface of the solidified body without interfering with other steps.

SUMMARY

A lamination molding apparatus of the disclosure includes: an irradiator irradiating a material layer with a beam to form a solidified layer, wherein the material layer is formed for each of a plurality of divided layers obtained by dividing a desired three-dimensional molded object at a predetermined height in 22a molding region; and a temperature adjustment device which abuts against a part or all of a solidified body, which includes an upper surface of the solidified body that is formed by laminating the solidified layer, and heats and cools the part or all of the solidified body to a set temperature. The temperature adjustment device has a temperature adjustment plate which is heated and cooled to the set temperature, and includes a revolving portion which revolves the temperature adjustment plate between an upright state in which the temperature adjustment plate stands upright along a vertical direction and a lying state in which the temperature adjustment plate lies down along a horizontal direction. The revolving portion sets the temperature adjustment plate to the upright state when the part or all of the solidified body including the upper surface of the solidified body is not heated and cooled by the temperature adjustment device, and sets the temperature adjustment plate to the lying state when the part or all of the solidified body including the upper surface of the solidified body is heated and cooled by the temperature adjustment device.

DESCRIPTION OF THE EMBODIMENTS

A lamination molding apparatus of the disclosure includes: an irradiator irradiating a material layer with a beam to form a solidified layer, wherein the material layer is formed for each of a plurality of divided layers obtained by dividing a desired three-dimensional molded object at a predetermined height in a molding region; and a temperature adjustment device which abuts against a part or all of a solidified body, which includes an upper surface of the solidified body that is formed by laminating the solidified layer, and heats and cools the part or all of the solidified body to a set temperature. The temperature adjustment device has a temperature adjustment plate which is heated and cooled to the set temperature, and includes a revolving portion which revolves the temperature adjustment plate between an upright state in which the temperature adjustment plate stands upright along a vertical direction and a lying state in which the temperature adjustment plate lies down along a horizontal direction. The revolving portion sets the temperature adjustment plate to the upright state when the part or all of the solidified body including the upper surface of the solidified body is not heated and cooled by the temperature adjustment device, and sets the temperature adjustment plate to the lying state when the part or all of the solidified body including the upper surface of the solidified body is heated and cooled by the temperature adjustment device.

Here, the set temperature specifically refers to a molding temperature T1and a cooling temperature T2.

According to the disclosure, the upper surface of the solidified body not only can be cooled but also can be heated by the temperature adjustment device arranged in the lamination molding apparatus, and the progress of the martensitic transformation can be further promoted. Furthermore, because the simple mechanism which switches the temperature adjustment plate between the upright state and the lying state is mounted, when the temperature adjustment of the upper surface of the solidified body is not performed, the temperature adjustment plate is set to the upright state, and when the temperature adjustment of the upper surface of the solidified body is performed, the temperature adjustment plate is set to the lying state. Thereby, the temperature adjustment of the upper surface of the solidified body can be appropriately performed without interfering with other steps.

In the lamination molding apparatus of the disclosure, the temperature adjustment plate has thermoelectric elements.

According to the disclosure, because the temperature adjustment plate is configured by the thermoelectric elements, the temperature adjustment plate can be switched from a heating state to a cooling state in a shorter time, and a solidified layer forming step can be performed quickly.

The lamination molding apparatus of the disclosure includes an attachment portion connecting the temperature adjustment plate and the revolving portion. The attachment portion includes a ball joint fixed to a back surface of the temperature adjustment plate and a receiving piece connected to the ball joint.

According to the disclosure, because the revolving portion and the temperature adjustment plate are slidably connected via the attachment portion, even when the parallelism of the solidified body is poor, the temperature adjustment plate can be reliably abutted against the upper surface of the solidified body, and the upper surface of the solidified body can be cooled uniformly and evenly.

In the lamination molding apparatus of the disclosure, the temperature adjustment device has a locking member to be connected to a drive device, and the locking member is a cylinder actioned to project a pin body and fit the pin body into a locking hole of the drive device when the temperature adjustment device is connected to the drive device. When a part or all of the solidified body including the upper surface of the solidified body is heated and cooled, the locking member is connected to the drive device, and by moving the drive device, the temperature adjustment device is moved from a retraction position away from the molding region to a processing position for heating and cooling which is adjacent to the molding region.

In addition, the lamination molding apparatus of the disclosure has the temperature adjustment device fixed to a back surface of a working door.

According to the disclosure, a structure can be adopted in which the temperature adjustment device is arranged in the processing position adjacent to the molding region when the temperature adjustment of the upper surface of the solidified body is performed, and the temperature adjustment device is arranged in the retraction position away from the molding region when the temperature adjustment of the upper surface of the solidified body is not performed. In addition, a structure can also be adopted in which the temperature adjustment device is fixed to the back surface of the working door.

By adopting the arrangement structure of the temperature adjustment device in this way, the temperature adjustment device does not interfere with other devices and other steps when the solidified layer forming step is performed.

In the lamination molding apparatus of the disclosure, the drive device is a recoater head which reciprocatively moves in a horizontal uniaxial direction and supplies and flattens a material powder to form the material layer, and the temperature adjustment device is connected to the recoater head and reciprocatively moves in the horizontal uniaxial direction.

According to the disclosure, because the drive mechanism for reciprocatively moving the temperature adjustment device also serves as a drive mechanism of the recoater head, it is not necessary to arrange an additional drive mechanism for the temperature adjustment device, and the function of the temperature adjustment device can be realized with a simpler structure.

According to the lamination molding apparatus of the disclosure, when the temperature adjustment of the solidified body is performed, the temperature adjustment plate which has been heated and cooled is set to the lying state and is abutted against the upper surface of the solidified body. Thereby the temperature of the solidified body can be increased or reduced more quickly, and the progress of the martensitic transformation can be promoted.

In addition, because the arrangement of the temperature adjustment plate can be switched from the upright state to the lying state, other steps such as a cutting step, loading and unloading of the three-dimensional molded object, or the like is not interfered with.

Furthermore, the lamination molding apparatus can be provided in which, by slidably connecting the temperature adjustment plate to the revolving portion, the temperature adjustment plate is inclined in accordance with the parallelism of the upper surface of the solidified body when the temperature adjustment plate is in the lying state, and thereby the temperature adjustment plate is steadily abutted against the upper surface of the solidified body, and the cooling can be uniformly performed.

1. First Embodiment

An embodiment of the disclosure is described below with reference to the drawings. Various feature items shown in the embodiment shown below can be combined with each other. In addition, each feature item independently constitutes an invention. In the following description, directions of an X-axis, a Y-axis, and a Z-axis are as defined inFIG.1andFIG.2. Specifically, a predetermined horizontal uniaxial direction is referred to as the X-axis, another horizontal uniaxial direction orthogonal to the X-axis is referred to as the Y-axis, and a predetermined vertical uniaxial direction is referred to as the Z-axis.

In addition, in a lamination molding apparatus of the embodiment, a control axis in the horizontal uniaxial direction, which is a moving direction of a recoater head11, is set as a B-axis, a horizontal uniaxial direction orthogonal to the B-axis of the recoater head11is set as a C-axis, and a control axis in a vertical uniaxial direction, which is a moving direction of a molding table5, is set as a U-axis. Furthermore, in the machine of the lamination molding apparatus, a side where a working door1cof a chamber1is arranged is set as an anterior surface or a front surface, a right-hand side toward the anterior surface is set as a right-side surface, a left-hand side is set as a left-side surface, and a rear side is set as a back surface. A dotted line in the diagram shows an irradiation path of a laser light L or a signal line.

FIG.1is a schematic front view of a lamination molding apparatus100according to a first embodiment of the disclosure, andFIG.2is a schematic side view of the lamination molding apparatus100according to the embodiment of the disclosure.FIG.3is a schematic perspective view of a material layer forming device3and an irradiator13according to the embodiment of the disclosure.FIG.5is a front perspective view of a temperature adjustment device60according to the embodiment of the disclosure, andFIG.6is a rear perspective view of the temperature adjustment device60according to the embodiment of the disclosure.

The lamination molding apparatus100according to the embodiment of the disclosure is a lamination molding apparatus which generates a three-dimensional molded object having a desired shape by laminating a plurality of solidified layers in a manner of repeating steps in which a material layer8is formed, and a beam which is, for example, the laser light L, is irradiated to an irradiation region of the material layer8to melt or sinter the irradiation region of the material layer8.

The lamination molding apparatus100of the disclosure includes the chamber1, an inert gas supply device15, a protection window pollution prevention device17, a fume collector19, a molding table5, the irradiator13, the material layer forming device3, a control device40, a cutting device50, the temperature adjustment device60, a temperature measurement unit70, and a table temperature adjustment device90. The chamber1covers a predetermined molding region R and is filled with an inert gas having a predetermined concentration.

The chamber1is a housing body of the lamination molding apparatus100, and inside the chamber1, the material layer forming device3is arranged which forms a material layer for each of a plurality of divided layers obtained by dividing a desired three-dimensional molded object at a predetermined height in the molding region R. A formed opening1bis arranged in an anterior surface of the chamber1, and the working door1chaving a viewing window is arranged in the opening1b(FIG.2).

The working door1cmay be revolvably arranged in the opening1bin a hinge opening/closing type, or may be formed into a left-right or up-down slide type. By opening or closing the working door1c, the taking out of the three-dimensional molded object, the removal of an unsintered material powder, and the like can be performed.

The temperature adjustment device60described later is arranged on a back surface of the working door1cto be capable of moving backward and forward in the B-axis direction along an inner side surface of the chamber1(FIG.2).

Specifically, a guide rail for temperature adjustment device64ais arranged in close proximity to a guide rail16R of the recoater head11described later in a manner of being parallel to the guide rail16R along the B-axis direction, which is a moving direction of the recoater head11(FIG.5andFIG.7). One end of the guide rail for temperature adjustment device64aextends to a position which is away from the molding region R and retracts from the back surface of the working door1c(a retraction position PE), and the other end is arranged extending to a processing position which is adjacent to the molding region R and is used for heating and cooling an upper surface of the solidified body81(a heating/cooling position PT).

When the temperature adjustment device60moves in the B-axis direction, the temperature adjustment device60and the recoater head11are connected, the recoater head11becomes a drive device for the temperature adjustment device60, and the temperature adjustment device60reciprocatively moves in the B-axis direction by a drive force of the recoater head11.

In addition, a locking member for retraction position1eis arranged at the retraction position PE (FIG.5) of the temperature adjustment device60in the chamber1, and a locking member for heating/cooling position1tis arranged at the heating/cooling position PT (FIG.5).

The locking member for retraction position1eand the locking member for heating/cooling position1tare members for engaging with a position fixing hole66of the temperature adjustment device60. The locking member for retraction position1eand the locking member for heating/cooling position1tare, for example, fluid pressure cylinders and electric cylinders. The locking member for retraction position1eand the locking member for heating/cooling position1tinclude a pin body, and the pin body can freely advance to and retract from the position fixing hole66of the temperature adjustment device60by an action of the cylinder. When the temperature adjustment device60is in a standby state or in the heating/cooling processing, the cylinder is actioned to project the pin body, and the pin body is inserted and fitted into the position fixing hole66to fix the temperature adjustment device60to the chamber1. On the other hand, when the temperature adjustment device60is moved, the cylinder is actioned to withdraw the pin body and pull out the pin body from the position fixing hole66, and the connection with the chamber1is released.

The material layer forming device3has a base4and the recoater head11. In the embodiment, the material forming the material layer8is made of a material powder. The material powder is, for example, a metal powder, and has, for example, a spherical shape having an average particle size of 20 μm.

The base4has the molding region R in which the desired three-dimensional molded object is formed. The molding region R is arranged on the molding table5. The molding table5is driven by a molding table drive mechanism31and can move in an up-down direction (the U-axis direction shown by an arrow inFIG.1). In the embodiment, when the lamination molding apparatus is used, a base plate33is arranged on the molding table5, and a material layer8which is the first layer is formed on the base plate33. Moreover, the irradiation region of the material layer8exists in the molding region R and almost coincides with a region defined by a contour shape of the desired three-dimensional molded object.

A powder holding wall26is arranged around the molding table5. An unsolidified material powder is held in a powder holding space surrounded by the powder holding wall26and the molding table5. A powder discharge portion capable of discharging the material powder in the powder holding space may be arranged on a lower side of the powder holding wall26.

The table temperature adjustment device90for adjusting a temperature of the molding table5is arranged inside the molding table5. As shown inFIG.4, the molding table5including the table temperature adjustment device90includes a top plate5aand three support plates5b,5c, and5d. A heater92capable of heating the top plate5ais arranged between the top plate5aand the support plate5badjacent the top plate5a. In addition, a cooler93capable of cooling the top plate5ais arranged between two support plates5cand5don a lower side of the support plate5b. The molding table5is configured to be capable of adjusting the temperature by the heater92and the cooler93, and the heater92and the cooler93configure the table temperature adjustment device90. Moreover, in order to prevent thermal displacement of the molding table drive mechanism31, a constant temperature portion which is maintained at a constant temperature may be arranged between the table temperature adjustment device90and the molding table drive mechanism31. By configuring the table temperature adjustment device90as described above, a lower solidified layer and the base plate33which is in contact with the top plate5aof the molding table5set to a desired temperature can be adjusted to a desired temperature. Moreover, the material layer8is desired to be preheated to a predetermined temperature when the material layer8is sintered or melted, and the table temperature adjustment device90acts as a preheating device of the material layer8.

The recoater head11shown inFIG.3has a material accommodation portion11a, a material supply portion11b, a material discharge portion (not shown), and a guide mechanism11c. The material accommodation portion11aaccommodates the material powder. The material supply portion11bis arranged on an upper surface of the material accommodation portion11a, and is a receiving port for the material powder supplied from a material supply device (not shown) to the material accommodation portion11a. The material discharge portion is arranged on a bottom surface of the material accommodation portion11aand discharges the material powder in the material accommodation portion11a. The material discharge portion is configured in a slit shape extending in the horizontal uniaxial direction (the C-axis direction shown by an arrow) orthogonal to the moving direction (the B-axis direction shown by an arrow) of the recoater head11. In addition, blades12are respectively arranged on both side surfaces of the recoater head11. The blade12flattens the material powder discharged from the material discharge portion to form the material layer8.

The guide mechanism11cis configured by a pair of bearings14R and14L, guide rails16R and16L which are a pair of shaft members respectively received by each of the bearings14R and14L, and a servomotor (not shown). The recoater head11reciprocatively moves on the molding table5in the B-axis direction along the guide rails16R and16L of the guide mechanism11cby the servomotor based on a scanning command of the control device40.

In addition, a locking hole18for fixing the temperature adjustment device60to the recoater head11is arranged on a side plate of the bearing14R of the guide mechanism11c. The locking hole18may have a shape engaging with a transport locking member65arranged in the temperature adjustment device60, and may be, for example, a groove, a non-through hole, a through hole, or the like.

An inert gas having a predetermined concentration is supplied to the chamber1, and the inert gas containing fume generated when the material layer8is melted is discharged. The inert gas discharged from the chamber1may be returned to the chamber1with the fume removed. Specifically, the inert gas supply device15is connected to the chamber1, and the fume collector19is connected to the chamber1via duct boxes21and23. The position and the number of the supply port and the discharge port of the inert gas which are arranged in the chamber1are not particularly limited. Moreover, in the disclosure, the inert gas refers to a gas that does not substantially react with the material, and an appropriate inert gas is selected from a nitrogen gas, an argon gas, a helium gas, and the like according to the type of the material.

The inert gas supply device15has a function of supplying the inert gas, and is, for example, an inert gas generation device which generates the inert gas having the predetermined concentration from the surrounding air or a gas cylinder in which the inert gas having the predetermined concentration is stored. As the inert gas generation device, inert gas generation devices in various methods, such as a membrane separation method, a PSA method, and the like, can be adopted according to the type and the concentration of the generated inert gas. The inert gas supply device15supplies the inert gas from the supply port arranged in the chamber1, and fills the inside of the chamber1with the inert gas having the predetermined concentration. Here, the inert gas supplied from the inert gas supply device15is desired to be dry. Specifically, a dew point temperature of the inert gas is desired to be lower than the temperature of the temperature adjustment device60. Because a temperature adjustment plate61described later of the temperature adjustment device60moves in the chamber1, if the inside of the chamber1is filled with the inert gas, the dew condensation of the temperature adjustment plate61can be suppressed. That is, when the inert gas supply device15is an inert gas generation device, a drying device which dries the air used as the raw material for generating the inert gas is desired to be arranged. In addition, when the inert gas supply device15is a gas cylinder, a gas cylinder in which the inert gas that has been sufficiently dried is stored is desired to be used.

The inert gas which is discharged from the discharge port of the chamber1and includes a large amount of fume is sent to the fume collector19, and after the fume is removed, the inert gas is returned to the chamber1. The fume collector19may have a function of removing the fume, and is, for example, an electrostatic precipitator or a filter.

The cutting device50includes a machining head51in which a spindle head52is arranged, and the machining head51moves the spindle head52to a desired position by a machining head drive mechanism (not shown).

The spindle head52is configured to be capable of gripping and rotating cutting tools (not shown) such as an end mill and the like, and can perform cutting machining on the surface and the unnecessary part of the solidified layer obtained by sintering the material layer8. The cutting tools may be a plurality of types of cutting tools, and the used cutting tool can also be replaced during molding by an automatic tool replacement device (not shown). By the above configuration, the machining head51can perform the cutting machining on the solidified layer at an arbitrary position in the chamber1.

The irradiator13is arranged above the chamber1. The irradiator13irradiates a beam such as the laser light L or the like to the predetermined section of the material layer8which is formed on the molding region R to melt or sinter the material layer8at the irradiation position, thereby forming the solidified layer. As shown inFIG.3, the irradiator13has a light source42, a two-axis galvano scanner43, and a focus control unit44. Moreover, the galvano scanner43includes galvano mirrors43aand43band actuators (not shown) which respectively rotate the galvano mirrors43aand43b.

The light source42irradiates the laser light L. Here, the laser light L is a laser capable of melting the material powder, and is, for example, a CO2laser, a fiber laser, a YAG laser, or the like. Moreover, the light source42may irradiate an electron beam.

The focus control unit44collects the laser light L output by the light source42and adjusts the laser light L to a desired spot diameter. The galvano mirrors43aand43bcontrollably scan the laser light L output by the light source42in a two-dimensional manner. Rotation angles of the galvano mirrors43aand43bare respectively controlled according to the magnitude of a rotation angle control signal input from the control device40. According to this feature, the laser light L can be irradiated to the desired position by changing the magnitude of the rotation angle control signal input to each actuator of the galvano scanner.

The laser light L passing through the galvano mirrors43aand43bpenetrates a protection window1aarranged in the chamber1and is irradiated to the material layer8formed in the molding region R. The protection window1ais formed by a material which the laser light L can penetrate. For example, when the laser light L is a fiber laser or a YAG laser, the protection window1acan be configured by quartz glass.

The protection window pollution prevention device17is arranged on an upper surface of the chamber1in a manner of covering the protection window1a. The protection window pollution prevention device17includes a cylindrical housing body17aand a cylindrical diffusion member17carranged in the housing body17a. An inert gas supply space17dis arranged between the housing body17aand the diffusion member17c. In addition, on a bottom surface of the housing body17a, an opening portion17bis arranged on an inner side of the diffusion member17c. A large number of fine holes17eare arranged in the diffusion member17c, and the clean inert gas supplied to the inert gas supply space17dfills a clean room17fthrough the fine holes17e. Besides, the clean inert gas filled in the clean room17fis ejected toward the bottom of the protection window pollution prevention device17through the opening portion17b.

The control device40performs overall control of the entire lamination molding apparatus100, and the control device40receives molding data generated in a CAM device (not shown), and performs numerical value control of controlling the laminate molding based on the received data. In addition, the control device40also serves as a device which performs the drive control of the material layer forming device3, the molding table5, the recoater head11, the irradiator13, the inert gas supply device15, the fume collector19, the cutting device50, the temperature adjustment device60, the temperature measurement unit70, the table temperature adjustment device90, and the like.

The temperature measurement unit70is a detection unit which measures the temperature of the solidified body81, and is attached to the cutting device50and used (FIG.2andFIG.14). For example, the temperature measurement unit70includes a contact type temperature sensor70awhich contacts the upper surface of the solidified body81and measures the temperature, and a temperature sensor elevating device70bwhich moves the temperature sensor70ain the vertical direction. The temperature sensor70ais, for example, a thermocouple, and other temperature sensors such as a resistance temperature detector and the like may be used. The temperature sensor elevating device70bis, for example, an air cylinder, and other drive mechanisms such as a hydraulic cylinder, an electric motor, and the like may be used. In addition, the temperature measurement unit70may also be configured by a non-contact type temperature sensor, and the temperature of the solidified body81can be measured more accurately by using the contact type temperature sensor70a. By using the temperature measurement unit70, feedback control corresponding to the temperature of the solidified body81can be performed. For example, the temperature measurement unit70can be configured to carry out a cooling step or a heating step performed by the temperature adjustment plate61until the temperature measured by the temperature sensor70areaches a predetermined temperature.

The temperature measurement unit70is not an essential component and may be omitted.

FIG.7is an enlarged front perspective view of the temperature adjustment device60according to the embodiment of the disclosure, andFIG.8is an enlarged rear perspective view of the temperature adjustment device60according to the embodiment of the disclosure. Moreover, inFIGS.7to9, a part of components of the lamination molding apparatus100such as the working door1cand the like are omitted in consideration of visibility.

The temperature adjustment device60according to the embodiment of the disclosure is a device for cooling or heating the three-dimensional molded object by bringing the temperature adjustment plate61into close contact with the upper surface of the solidified layer obtained by sintering the material layer8. The temperature adjustment device60is arranged on the back surface of the working door1cbetween an inner wall of the chamber1on a front surface side and the recoater head11, and is arranged in a manner of engaging with the recoater head11to be capable of reciprocatively moving in the B-axis direction (FIG.1andFIG.7).

The temperature adjustment device60is configured by the temperature adjustment plate61, an attachment portion62, a revolving portion63, the transport locking member65, and the position fixing hole66.

The temperature adjustment plate61is a flat plate shape member which is in close contact with the upper surface of the solidified body81formed by laminating the solidified layers which are formed by irradiating the beam such as the laser light L or the like to the material layer8, and heats and cools the upper surface of the solidified body81. The temperature adjustment plate61is configured by a heating/cooling plate61a, thermoelectric elements61b, and a lead wire connection portion61c. Moreover, the upper surface of the solidified body81means an upper surface of the uppermost solidified layer at the time when heating and cooling are performed by the temperature adjustment device60.

The heating/cooling plate61ais a substrate which actually contacts the upper surface of the solidified body81, and functions as a contact surface for heating and cooling the solidified body81. The heating/cooling plate61ais formed by an insulating substrate such as a ceramic material or the like.

The thermoelectric element61bis an element that converts electric energy into heat energy, and a plurality of the thermoelectric elements61bare arranged in an array on a back surface of the heating/cooling plate61a. As the thermoelectric element61b, for example, a semiconductor thermoelectric element such as a Peltier element or the like is used. When a direct current flows through the lead wire connection portion61c, the thermoelectric element61bcools (absorbs heat) at one end surface connected to the heating/cooling plate61a, and generates heat (heats) at the other end surface. When the direction of the direct current is changed, the cooling surface and the heating surface are switched, and the switching between heating and cooling can be performed in a short time. By performing the cooling and the heating at one surface of the thermoelectric element61bin this way, the upper surface of the solidified body81can be heated and cooled via the heating/cooling plate61a, and highly precise and quick temperature management can be realized.

The lead wire connection portion61cis a terminal for connecting the thermoelectric element61band a lead wire (not shown).

FIG.9is a side view of the temperature adjustment device60in which the temperature adjustment plate61according to the embodiment of the disclosure is in an upright state, andFIG.10is a side view of the temperature adjustment device60in which the temperature adjustment plate61according to the embodiment of the disclosure is in a lying state.

The revolving portion63is a member which revolves the temperature adjustment plate61between the lying state in which the temperature adjustment plate61lies down along the horizontal direction (a direction parallel to an XY plane) and the upright state in which the temperature adjustment plate61stand upright along the vertical direction (a Z direction). When the temperature adjustment by the temperature adjustment device60is not performed, the temperature adjustment plate61is set to the upright state shown inFIG.9. When the temperature adjustment by the temperature adjustment device60is performed, the temperature adjustment plate61is set to the lying state shown inFIG.10. In this way, when the solidified layer is formed by the irradiator13, when the solidified layer is machined by the cutting device50, when the material layer8is formed on the base plate33by the recoater head11, and in other cases, each device of the lamination molding apparatus100and the temperature adjustment plate61can be prevented from interfering with each other.

The revolving portion63is, for example, an air rotary actuator. As the revolving portion63, other revolving mechanisms such as a hydraulic rotary actuator, an electric rotary actuator, and the like may be used.

The attachment portion62is a member for connecting the temperature adjustment plate61and the revolving portion63, and is configured by a back surface attachment portion621and a lower attachment portion622.

The back surface attachment portion621is fixed to a back surface of the thermoelectric element61b, and a ball joint621ais arranged at the center position of the thermoelectric element61b. A lower end of the lower attachment portion622is fixed to a rotation shaft of the revolving portion63and is erected in the vertical direction, and a receiving piece622aconnected to the ball joint621ais arranged at an upper end of the lower attachment portion622.

An abutting surface between the ball joint621aand the receiving piece622ais formed to slide freely, and the revolving portion63and the temperature adjustment plate61are slidably connected via the attachment portion62.

By using this connection structure between the revolving portion63and the temperature adjustment plate61, even when a parallelism of the upper surface of the solidified body81is poor, the temperature adjustment plate61can be appropriately abutted against the upper surface of the solidified body81, and an excessive force can be avoided to be applied to either the temperature adjustment plate61or the upper surface of the solidified body81.

In addition, a slider64bis fixed to a bottom surface of the revolving portion63, and the slider64bslides along the guide rail for temperature adjustment device64a. Moreover, as the slider64b, a known slider can be properly used, and the temperature adjustment device60reciprocatively moves in the B-axis direction in a manner of being connected to the recoater head11.

The transport locking member65is a member for engaging with the locking hole18of the recoater head11, and for example, a known fluid pressure cylinder or a known electric cylinder is used. The transport locking member65is arranged at a position which is below the temperature adjustment device60when the temperature adjustment plate61is in the upright state and can be engaged with the locking hole18of the recoater head11.

A cylinder65, which is the transport locking member65, includes a pin body65b, and the pin body65bcan freely advance to and retract from the locking hole18of the recoater head11by the action of the cylinder65. When the temperature adjustment device60is connected to the recoater head11, the cylinder65is actioned to project the pin body65b, and the pin body65bis inserted and fitted into the locking hole18of the recoater head11. In addition, when the connection between the temperature adjustment device60and the recoater head11is released, the cylinder65is actioned to withdraw the pin body65band pull out the pin body65bfrom the locking hole18of the recoater head11.

The position fixing hole66is a hole for fixing the temperature adjustment device60to the retraction position PE and the processing position PT for performing the heating and the cooling, and the position fixing hole66is arranged below the temperature adjustment device60(FIG.8). The position fixing hole66may have a shape engaging with the locking member for retraction position1eand the locking member for heating/cooling position1t, and may be, for example, a groove, a non-through hole, a through hole, or the like.

(1.3 Manufacturing Method of Three-Dimensional Molded Object)

FIG.11is an illustration diagram (a standby state) of a solidified layer forming step using the lamination molding apparatus100according to the embodiment of the disclosure.FIG.12is an illustration diagram (a state before rotation) of the solidified layer forming step using the lamination molding apparatus100according to the embodiment of the disclosure, andFIG.13is an illustration diagram (a state after rotation) of the solidified layer forming step using the lamination molding apparatus100according to the embodiment of the disclosure.FIG.14is an illustration diagram (a temperature detection step) of the solidified layer forming step using the lamination molding apparatus100according to the embodiment of the disclosure, andFIG.15is a flow diagram showing the solidified layer forming step using the lamination molding apparatus100according to the embodiment of the disclosure. A manufacturing method of a three-dimensional molded object using the lamination molding apparatus100is described with reference toFIGS.11to15. Here, with respect to the illustration diagrams ofFIGS.11to14, the solidified body81is omitted for convenience of the description, but in the actual solidified layer forming step, the solidified body81is formed in the molding region R.

The lamination molding apparatus100of the embodiment is particularly effective for a manufacturing method of a three-dimensional molded object in which the temperature adjustment is performed on the solidified layer during molding. As the manufacturing method of a three-dimensional molded object in which the temperature adjustment is performed on the solidified layer during molding, a molding method is exemplified in which a martensitic metal is used as the material forming the material layer8, and the temperature adjustment is performed on the solidified layer each time the one or more solidified layers are formed to intentionally progress the martensitic transformation. More specifically, each time the one or more solidified layers are newly molded, the temperature adjustment is performed on the solidified layer which is newly molded in the order of a molding temperature T1, a cooling temperature T2, and the molding temperature T1. Moreover, if a martensitic transformation starting temperature of the solidified layer is set to Ms and a martensitic transformation ending temperature of the solidified layer is set to Mf, all the relationships of the following equations (1) to (3) are satisfied.
T1≥Mf(1)
T1>T2  (2)
T2≤Ms(3)

Moreover, the application invention is also effective for other manufacturing methods of a three-dimensional molded object in which the temperature adjustment is performed on the solidified layer during molding.

In the following, the one or more solidified layers cooled by the temperature adjustment device60are referred to as upper surface layers. The upper surface layer includes at least the uppermost solidified layer of the solidified body81at each cooling time point. After sintering, the upper surface layer before being cooled in the cooling step is in a state containing an austenite phase, and a part or all of the austenite phase is transformed into a martensite phase by cooling the upper surface layer to the cooling temperature T2.

First, a height of the molding table5is adjusted to an appropriate position in a state where the base plate33is placed on the molding table5(S101).

After the height of the molding table5is adjusted, the solidified layer forming step is performed. In the solidified layer forming step, the heater92of the table temperature adjustment device90arranged in the molding table5is driven to heat the molding table5to the molding temperature T1(S102), and the thermoelectric element61bof the temperature adjustment device60is applied to heat the heating/cooling plate61ato the molding temperature T1(S103). Here, as shown inFIG.11, the temperature adjustment device60is in a state where the temperature adjustment plate61is in the upright state and the temperature adjustment device60is stopped at the retraction position PE, the locking member for retraction position1eand the position fixing hole66of the temperature adjustment device60are engaged with each other, and the temperature adjustment device60is fixed to the chamber1.

Next, a recoating step and a solidification step shown below are repeated one or more times.

In the recoating step, the recoater head11in which the material powder is filled in the material accommodation portion11ais moved from a left side of the paper surface to the right side (FIG.1) in the B-axis direction shown by the arrow. Thereby, the material layer8is formed on the base plate33(S104).

Next, in the solidification step, by irradiating the laser light L to the irradiation region of the material layer8, this irradiation region is melted or sintered, and a solidified layer81awhich is the first layer is formed on the base plate33(S105).

When the temperature adjustment is performed on the plurality of solidified layers at once, the height of the molding table5is subsequently lowered by the thickness of the material layer8, and the recoating step and the solidification step are performed again. Specifically, the recoater head11is moved from a right side of the molding region R to the left side, and the material layer8is formed on the molding region. Then, the laser light L is irradiated to the irradiation region of the material layer8to melt or sinter the irradiation region, and a solidified layer81bwhich is the second layer is formed on the base plate33.

In this way, in the solidified layer forming step, the solidified body81is formed by repeating the formation of the plurality of solidified layers81a,81b. . . . These solidified layers which are sequentially laminated are firmly fixed to each other (FIG.22).

After the above steps are repeated and the predetermined one or more solidified layers are formed, the heating step and the cooling step are performed by the temperature adjustment device60. In the heating step, the temperature of the upper surface layer of the solidified body81is heated to the molding temperature T1, and then the temperature of the upper surface layer of the solidified body81is cooled to the cooling temperature T2in the cooling step.

In the heating step, first, the locking member for retraction position1eis operated to release the connection between the chamber1and the temperature adjustment device60, and the temperature adjustment device60and the recoater head11are connected by operating the transport locking member65. Then, the recoater head11is moved to the heating/cooling position PT along the B-axis direction, and thereby the connected temperature adjustment device60is moved from the retraction position PE to the heating/cooling position PT in the state where the temperature adjustment plate61is in the upright state (S106).

Thereafter, the locking member for heating/cooling position1tis operated to fix the temperature adjustment device60to the chamber1, the transport locking member65is operated to release the connection between the temperature adjustment device60and the recoater head11, and the recoater head11is retracted from the molding region R along the B-axis direction (FIG.12).

Then, as shown inFIG.13, by driving the revolving portion63, the temperature adjustment plate61is revolved to the lying state, the heating/cooling plate61ais abutted against the upper surface of the solidified body81, and the upper surface of the solidified body81is heated to the molding temperature T1(S107). By using the ball joint621aas the connection structure between the revolving portion63and the temperature adjustment plate61, the abutting surface between the ball joint621aand the receiving piece622aslides, and the heating/cooling plate61acan be brought into close contact with the entire upper surface of the solidified body81.

As shown inFIG.14, the temperature measurement unit70is moved above the solidified body81to measure the temperature of the upper surface of the solidified body81, and the feedback control may be performed in which the solidified body81is heated until the temperature of the upper surface of the solidified body81reaches the molding temperature T1(S108).

When the temperature of the upper surface of the solidified body81becomes the molding temperature T1, the process moves to the cooling step.

In the cooling step, the heater92of the table temperature adjustment device90which is arranged in the molding table5is stopped, the cooler93of the table temperature adjustment device90is driven, and the lower solidified layer and the base plate33which is in contact with the top plate5aof the molding table5are cooled (S109). At this time, the molding table5does not need to be cooled to the cooling temperature T2, as long as the molding table5is cooled to an extent that excessive heat transmission to the solidified body81can be suppressed.

Furthermore, the thermoelectric element61bof the temperature adjustment device60is applied to cool the heating/cooling plate61ato the cooling temperature T2, and the upper surface layer of the solidified body81is cooled to the cooling temperature T2by the temperature adjustment plate61(S110).

As described above, the cooling temperature T2is equal to or less than the martensitic transformation starting temperature Ms. The cooling temperature T2may be equal to or less than the martensitic transformation ending temperature Mf. At this time, the progress of the martensitic transformation of the three-dimensional molded object after molding can be prevented. Specific values of the martensitic transformation starting temperature Ms and the martensitic transformation ending temperature Mf vary according to the composition of the material. Therefore, it is necessary to set the cooling temperature T2to a low temperature such as −20° C. or the like according to the material. In the lamination molding apparatus100of the embodiment, only a part of the solidified body81including the upper surface layer may be cooled, and thus the upper surface layer can be quickly cooled even if the cooling temperature T2is low, and the upper surface layer can be quickly reheated to the molding temperature T1after the cooling step.

In addition, similar to the heating step, the temperature of the upper surface of the solidified body81is measured by the temperature measurement unit70, and the feedback control may be performed in which the solidified body81is cooled until the temperature of the upper surface of the solidified body81reaches the cooling temperature T2(S111).

When the cooling step is completed, the temperature adjustment plate61of the temperature adjustment device60is revolved from the lying state to the upright state by the revolving portion63(S112). Then, the recoater head11is driven to be moved to the heating/cooling position PT along the B-axis direction, the locking member for heating/cooling position1tis operated to release the connection between the chamber1and the temperature adjustment device60, and the temperature adjustment device60and the recoater head11are connected by operating the transport locking member65. By moving the recoater head11to the retraction position PE along the B-axis direction, the connected temperature adjustment device60is moved from the heating/cooling position PT to the retraction position PE in the state where the temperature adjustment plate61is in the upright state (S113).

Thereafter, the locking member for retraction position1eis operated to fix the temperature adjustment device60to the chamber1, and the transport locking member65is operated to release the connection between the temperature adjustment device60and the recoater head11.

Thereafter, the molding temperature T1is set and the solidified layer forming step is performed again. At least until the next solidification step is performed, the temperature of the molding table5is adjusted to the molding temperature T1by the table temperature adjustment device90arranged on the molding table5, and the thermoelectric element61bof the temperature adjustment device60is further applied to heat the heating/cooling plate61ato the molding temperature T1. The temperature of the material layer8is reheated to the molding temperature T1.

As described above, in the embodiment, the temperature of the temperature adjustment plate61is adjusted in a manner that the thermoelectric element61bof the temperature adjustment device60is applied to heat the heating/cooling plate61ato the molding temperature T1in the heating step, and the temperature adjustment plate61is switched from heating to cooling in a short time to adjust the temperature to the cooling temperature T2in the cooling step. The upper surface layer of the solidified body81is heated and cooled by abutting the temperature adjustment plate61against the upper surface of the solidified body81. Thereby, compared with the case in which only the temperature adjustment mechanism arranged in the molding table5is used to heat and cool, the temperature of the upper surface layer can be adjusted more quickly, and the molding time of the three-dimensional molded object can be shortened.

2. Second Embodiment

FIG.16is a schematic side view of a lamination molding apparatus200according to a second embodiment of the disclosure.FIG.17is a rear perspective view of a temperature adjustment device260according to the embodiment of the disclosure.

The temperature adjustment device60according to the first embodiment is arranged to be capable of moving backward and forward in the B-axis direction along the inner side surface of the chamber1, but the temperature adjustment device260according to the second embodiment of the disclosure is different in that the temperature adjustment device260is integrally attached to the back surface of the working door1c, and other configurations and actions in the first embodiment are the same as those in the second embodiment. Thus, the same configurations and actions are designated by the same reference numerals and detailed description thereof is omitted.

The lamination molding apparatus200according to the embodiment of the disclosure is a lamination molding apparatus which generates a three-dimensional molded object having a desired shape by laminating the plurality of solidified layers in a manner of repeating the steps in which the material layer8is formed in the molding region R in which the three-dimensional molded object is formed, and the beam which is, for example, the laser light L, is irradiated to the irradiation region of the material layer8to melt or sinter the irradiation region of the material layer8.

The lamination molding apparatus200of the disclosure includes the chamber1, the inert gas supply device15, the protection window pollution prevention device17, the fume collector19, the molding table5, the irradiator13, the material layer forming device3, the control device40, the cutting device50, the temperature adjustment device260, the temperature measurement unit70, and the table temperature adjustment device90.

The chamber1is a housing body of the lamination molding apparatus200, the formed opening1bis arranged in the anterior surface of the chamber1, and the working door1chaving a viewing window1dis arranged in the opening1b(FIG.16,FIG.17, andFIG.20).

The working door1cis revolvably arranged in the opening1bin a hinge opening/closing type, and the temperature adjustment device260described later is fixed to the back surface of the working door1cin a manner of be changeable from the upright state (FIG.18) to the lying state (FIG.19) and from the lying state to the upright state.

In addition, the temperature adjustment device260is arranged to be stored in the back surface of the working door1c(FIG.17), and problems, for example, the temperature adjustment device260does not interfere when the working door1cis opened and closed, and the like do not occur.

FIG.18is a side view of the temperature adjustment device260in which the temperature adjustment plate61according to the embodiment of the disclosure is in the upright state.FIG.19is a side view of the temperature adjustment device260in which the temperature adjustment plate61according to the embodiment of the disclosure is in the lying state.

The temperature adjustment device260according to the embodiment of the disclosure is a device for heating or cooling the three-dimensional molded object by bringing the temperature adjustment plate61into close contact with the upper surface of the solidified layer obtained by sintering the material layer8, and the temperature adjustment device260is fixed to the back surface of the working door1c(FIG.16andFIG.17).

The temperature adjustment device260is configured by the temperature adjustment plate61, the attachment portion62, a revolving portion263, and a working door attachment portion267.

The temperature adjustment plate61is a flat plate shape member which is in close contact with the upper surface of the solidified body81formed by laminating the solidified layers which are formed by irradiating the beam such as the laser light L or the like to the material layer8.

The revolving portion263is a member which revolves the temperature adjustment plate61between the lying state in which the temperature adjustment plate61lies down along the horizontal direction (the direction parallel to the XY plane) and the upright state in which the temperature adjustment plate61stand upright along the vertical direction (the Z direction). When the temperature adjustment by the temperature adjustment device260is not performed, the temperature adjustment plate61is set to the upright state shown inFIG.18. When the temperature adjustment is performed, the temperature adjustment plate61is set to the lying state shown inFIG.19.

The revolving portion263is, for example, an air cylinder. As the revolving portion263, other revolving mechanisms such as a hydraulic cylinder, an electric actuator, and the like may be used.

The attachment portion62is the member for connecting the temperature adjustment plate61and the revolving portion263, and is configured by the back surface attachment portion621and the lower attachment portion622. The back surface attachment portion621is fixed to the back surface of the thermoelectric element61b, and the ball joint621ais arranged at the center position of the thermoelectric element61b. The lower end of the lower attachment portion622is fixed to a rotation shaft of the revolving portion263and is erected in the vertical direction, and the receiving piece622aconnected to the ball joint621ais arranged at the upper end of the lower attachment portion622. The abutting surface between the ball joint621aand the receiving piece622ais formed to slide freely, and the revolving portion263and the temperature adjustment plate61are slidably connected via the attachment portion62.

The working door attachment portion267for fixing to the working door1cis fixed to the bottom surface of the revolving portion263(FIG.16andFIG.17), and the working door attachment portion267is fixed to the back surface of the working door1c.

(2.3. Manufacturing Method of Three-Dimensional Molded Object)

FIG.20is an illustration diagram (a state after rotation) of a solidified layer forming step using the lamination molding apparatus200according to the embodiment of the disclosure, andFIG.21is a flow diagram showing the solidified layer forming step using the lamination molding apparatus200according to the embodiment of the disclosure.

With respect to the illustration diagram ofFIG.20, the solidified body81is omitted, but in the actual solidified layer forming step, the solidified body81is formed in the molding region R.

Similar to the lamination molding apparatus100according to the first embodiment, in the lamination molding apparatus200of the embodiment, the molding method is used in which the martensitic metal is used as the material for forming the material layer8, and the temperature adjustment is performed on the solidified layer each time the one or more solidified layers are formed to intentionally progress the martensitic transformation. More specifically, each time the one or more solidified layers are newly molded, the temperature adjustment is performed on the solidified layer which is newly molded in the order of the molding temperature T1, the cooling temperature T2, and the molding temperature T1.

First, the position of the height of the molding table5is adjusted (S101), the heater92of the table temperature adjustment device90is heated to the molding temperature T1(S102), and the thermoelectric element61bof the temperature adjustment device260is applied to heat the heating/cooling plate61ato the molding temperature T1(S103). Here, as shown inFIG.16, the temperature adjustment device260is fixed to the back surface of the working door1cin the state where the temperature adjustment plate61is in the upright state.

Then, the recoating step (S104) and the solidification step (S105) are repeated one or more times.

After the one or more solidified layers are formed, the heating step and the cooling step are performed by the temperature adjustment device260. In the heating step, the temperature of the upper surface layer of the solidified body81is heated to the molding temperature T1, and then the temperature of the upper surface layer of the solidified body81is cooled to the cooling temperature T2in the cooling step.

In the heating step, as shown inFIG.20, by driving the revolving portion263, the temperature adjustment plate61is revolved to the lying state, the heating/cooling plate61ais abutted against the upper surface of the solidified body81, and the upper surface of the solidified body81is heated to the molding temperature T1(S201). By using the ball joint621aas the connection structure between the revolving portion263and the temperature adjustment plate61, the abutting surface between the ball joint621aand the receiving piece622aslides, and the heating/cooling plate61acan be brought into close contact with the entire upper surface of the solidified body81.

The temperature of the upper surface of the solidified body81is measured by the temperature measurement unit70, and the feedback control may be performed (S108).

When the temperature of the upper surface of the solidified body81becomes the molding temperature T1, the process moves to the cooling step.

In the cooling step, the cooler93of the table temperature adjustment device90is driven to cool the lower solidified layer (S109), the thermoelectric element61bof the temperature adjustment device260is applied to cool the heating/cooling plate61ato the cooling temperature T2, and the upper surface layer of the solidified body81is cooled to the cooling temperature T2by the temperature adjustment plate61(S110).

In addition, similar to the heating step, the temperature of the upper surface of the solidified body81is measured by the temperature measurement unit70, and the feedback control may be performed in which the solidified body81is cooled until the temperature of the upper surface of the solidified body81reaches the cooling temperature T2(S111).

When the cooling step is completed, the temperature adjustment plate61of the temperature adjustment device260is revolved from the lying state to the upright state by the revolving portion263(S202). Thereafter, the molding temperature T1is set, and the solidified layer forming step is further performed.

In this way, because the temperature adjustment device260is fixed to the back surface of the working door1c, it is not necessary to drive the temperature adjustment device260by the drive mechanism when the solidified body81is heated and cooled, and the function can be realized by a simple structure without interfering with other steps.