JPH0318484A - Method for forming three-dimensional object and device used therein - Google Patents

Abstract

PURPOSE:To form the three-dimensional object directly from inorg. material powder by previously storing the build-up data of the respective parts of the three-dimensional object, supplying the inorg. material powder to a plasma torch, forming weld beads and three-dimensionally moving the plasma torch in accordance with the build-up data. CONSTITUTION:A control device 7 previously stores or computes the build-up data of the respective parts of the three-dimensional object. The inorg. material powder is then supplied to the plasma torch 3 and the weld beads are formed. Either one or both of the plasma torch 3 and a work table 1 are three- dimensionally and relatively moved in accordance with the build-up data to successively build up the weld beads by thermal spraying on the work table 1, by which the three-dimensional object is formed. The direct forming of the three-dimensional object from the inorg. material powder is, therefore, possible without using cutting tools, metallic molds or binder components.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a plasma powder melting method (Plasma powder melting method).
ma powder melting mej. hod
．． The present invention relates to a method of modeling a three-dimensional object made of an inorganic material using the PPM method (hereinafter referred to as the PPM method), and an apparatus used in the method.

(Conventional technology) For example, when creating a three-dimensional object from metal or ceramics, conventionally the main method was to cut blocks of these materials using machine tools such as lathes. ．． Recently, by using a CAD/CAM system, design drawing data of a three-dimensional object to be modeled is input into an NC control device, where the data is converted into a program, and the converted data is used to control a machine tool as a CAM system. By operating the mill, the mill block is cut.

In addition to the above-mentioned cutting process, there are also methods for molding three-dimensional objects from inorganic materials, such as pouring molten metal into a mold of a predetermined shape and casting it, metal injection molding, and molding of inorganic materials. Powder is filled into a mold with a binder for HP and HI
There is a powder metallurgy method of sintering it with P, and each of these methods is widely used.

(Mu to be solved by the invention) However, in the case of modeling a three-dimensional object by cutting as described above, when cutting a material block, the machining e! Thermal distortion occurs in machines and material blocks, making it difficult to create three-dimensional objects with high machining accuracy.Also, machine tools are subject to high loads, so materials for tools, etc. need to be highly rigid. become. Furthermore, processing takes a long time, and when the shape of the three-dimensional object to be modeled changes, it is necessary to install corresponding machining jigs, and the setup time is also long, resulting in a decrease in productivity. It is unsuitable for production.
Furthermore, if the material block is made of a difficult-to-process material such as Hastelloy, cutting the material is extremely difficult. Furthermore, in the case of cutting using a CAD/CAM system, the designer himself/herself cannot create a three-dimensional object based on drawing data designed using the CAD system as an actual object on the spot.

In addition, when modeling three-dimensional objects using casting or powder metallurgy,
First of all, it is necessary to produce molds that are dense and therefore expensive. Furthermore, the casting conditions during casting and the sintering conditions during sintering must be strictly controlled.

On the other hand, in the field of shaping organic materials, the creation of three-dimensional objects using stereolithography has recently been attracting attention. In this method, cross-sectional figure data is created using CAD, this figure data is taken out sequentially from the bottom end, and a liquid photocurable resin is sequentially exposed to a light beam in a scanning pattern based on the figure data. The photocurable resin in the portion exposed to the light beam is solidified, and a solidified layer with a pattern corresponding to the scanning pattern of the light beam is formed in the liquid photocurable resin. Then, this solidified layer is submerged in liquid photocurable resin to a depth corresponding to the thickness of the graphic data on the CAD, and then a light beam is applied in a scanning pattern based on the graphic data to cover the solidified layer. exposure onto the plastic resin. By repeating this operation until reaching the upper end of the CAD graphic data, a cured resin three-dimensional object is modeled, which is an aggregate of VI layers of solidified layers corresponding to the graphic data of the shape grooved on the CAD.

However, this method can only be applied to photocurable resins, and cannot be applied to, for example, molding three-dimensional objects from inorganic materials such as metals and various ceramics.

The present invention utilizes the above-described stereolithography method, and in addition,
The object of the present invention is to provide a method and a device for forming a three-dimensional object from an inorganic material by combining melting and overlaying techniques using the PPM method.

(Means for Solving the Problem) In order to achieve the above object, in the present invention, overlay data for each part of a three-dimensional object to be modeled is stored or calculated in advance, and inorganic material is applied to the Brass 71-chi. The powder is supplied to form a melted bead, and one or both of the plasma torch and the work table are moved relative to each other in three dimensions based on the build-up data, and the molten bead is placed on the work table. A three-dimensional object modeling method is provided, which is characterized in that a three-dimensional object is formed by sequentially thermal spraying and overlaying a three-dimensional object. And plasma 1! A plasma torch that is connected to a source device and an inorganic material powder supply device and sprays and overlays a molten bead of the inorganic material onto the work table; a plasma torch that is connected to a source device and an inorganic material powder supply device; a moving device that relatively moves the objects; and stores or calculates overlay command data for each part of the three-dimensional object to be modeled;
While moving the moving device based on the overlay command data, the plasma torch sequentially sprays and overlays the molten bead of the inorganic material onto the work table to form the three-dimensional object on the work table. A three-dimensional object modeling apparatus is provided, comprising: a control device that transmits an operation signal to perform an operation.

(Function) In the apparatus of the present invention, a molten bead of inorganic material is shaped by a plasma torch, and this molten bead is thermally sprayed onto a work table and overlaid to form a three-dimensional object.

At this time, the formation of a molten bead with an appropriate width and thickness by the plasma torch, and the command data for the relative movement between the plasma torch and the work table are all stored or calculated in the control device, and the three-dimensional object to be modeled is stored or calculated in the control device. Position and amount of overlay corresponding to each part. Since the movement of the moving device operates based on the build-up command data that displays the build-up order, the three-dimensional object to be modeled is a reconstructed object with the same shape as the three-dimensional object stored or calculated in the control device. become.

The method of the present invention can extremely easily mold not only a three-dimensional object with a simple shape but also a three-dimensional object with a hollow interior and a narrow opening. Since it is an inorganic material, it is heat resistant. It is a very useful three-dimensional object in that it can create three-dimensional objects with excellent mechanical strength, and since it is a non-contact processing method, there is no need for jigs such as machine tools or molds. It can be said that it is a modeling method. (Example) Below, an example apparatus and method of the present invention will be explained in more detail based on the drawings.

FIG. 1 is a schematic diagram of the device of the present invention in which the horizontal control elements are combined.

In the figure, first, a work table 1 is attached to a moving @ station 2, and a target three-dimensional object is modeled on this table. This moving device 2 performs linear movement in the front and back, left and right, up and down directions, axis rotation movement, and a combination of these movements in response to operation signals based on build-up command data from a control device, which will be described later. The platform can be moved in any three-dimensional direction.

Regarding relative movement between the work table 1 and the moving device 2, one of the work table 1 and the moving device 2 may be stationary and the other may be movable, or both may be movable. It's okay.

A plasma torch 3 is placed opposite the work surface 1a of the work table 1. The plasma torch 3 only needs to be of the same type as conventionally used in plasma spraying and plasma welding, and has a restraining nozzle for operating gas (inner nozzle) and a gas nozzle for shielding gas (outer nozzle). It has a double nozzle structure.

This plasma torch 3 is connected to a supply device 4 for inorganic material powder 4b via a powder supply pipe 4a, and is electrically connected to a plasma power supply device 5 via a tungsten electrode lead 5 in the torch. There is.

Furthermore, the plasma torch 3 is connected to a cooling water circulation device 6 via a cooling water pipe 6a, and the restraint nozzle is cooled by the cooling water circulating in W1, so that the thermal pinching effect of the generated plasma column can be suppressed. There is.

Further, a beam 5b is pulled out from the plasma power supply device 5 and connected to the work table l, so that a plasma column can be generated between the plasma torch 3 and the work table l.

Note that the number of supply devices 4 does not need to be one as shown in the figure. For example, when a target three-dimensional object is formed from a plurality of types of inorganic materials with a certain molten bead, a plurality of supply devices 4 may be arranged.
Each of them may be connected to the plasma torch 3 through a plurality of powder supply pipes.

The control device 7 stores or calculates build-up command data for each part of the three-dimensional object to be modeled, and based on this build-up command data, sends an operation command signal to the plasma power supply device 5 via a line 7a to turn on the plasma. The generation timing and plasma current value are properly managed, and an operation command signal is sent to the supply device 4 via the line 7b to appropriately manage the supply timing and supply amount of the inorganic material powder 4b. ,7d
Sends an operation command signal to the plasma torch 3 via the controller to appropriately manage the plasma gas pressure of the plasma torch 3,
Further, an operation command signal is sent to the mobile device 2 via the line 7e.

The overlay command data referred to here refers to the three-dimensional positional relationship, shape, and dimensions of arbitrary parts when the three-dimensional object to be modeled is made into a collection of minute arbitrary parts arranged continuously. It is data related to the material composition and the arrangement order of arbitrary parts thereof, and a typical example is continuous multilayer cross-sectional data obtained when a three-dimensional object to be modeled is horizontally sliced at predetermined intervals.

Such data may be prepared by the designer in advance prior to modeling and input and stored in the control device 7, or the control device 7 may be equipped with a CAD system to create the desired three-dimensional structure. It may also be possible to perform calculations for graphical processing of arbitrary parts of objects. Next, the modeling method performed using this device will be explained based on the above-mentioned continuous multilayer cross-sectional data of the three-dimensional object to be modeled. First, powder of a desired inorganic material is stored in the supply device 4. As the target inorganic material, one is selected that is a constituent material of the target three-dimensional object and is melted by plasma to form a molten bead.

For example, ceramic powders such as various metal 5 alloys, carbides, nitrides, etc. are selected.

Of the entire continuous multilayer cross-sectional data, data in a certain order (
Based on the overlay command data Noi regarding the i-th data), the control device 7 transmits an operation command signal to the plasma power supply device 5 via the line 7a. The plasma power supply device operates according to the command data Noi, supplies a predetermined value of plasma current to the plasma torch 3, and generates a transferred arc between the tungsten electrode of the plasma torch 3 and the work table 1. At the same time, cooling water is introduced from the cooling water circulation device 6 to the plasma torch 3 via the cooling water pipe 6a, and by forcibly cooling the restraint nozzle and the operating gas (for example, Ar), the contracted and restrained plasma column is turned into a plasma. It is formed between the torch 3 and the work surface 1a of the work stand.

In parallel with this operation, the control device 7 transmits an operation command signal to the supply device W4 via the line 7b, and a predetermined amount of the inorganic material powder 4b is supplied to the plasma column of the plasma torch 3 via the supply pipe 4a. It is inserted into the container at a predetermined angle.

The charged inorganic material powder 4b melts while falling toward the work table 1, and becomes a molten bead having a predetermined width and thickness.

Further, based on the command data Noi, the controller 11l device 7 transmits an operation command signal to the mobile device 2 via the line MAe. The moving device 2 performs a predetermined movement based on the operation command signal, and as a result, the work table 1 moves in the same pattern as the command data Noi.

As a result, the above-mentioned molten bead is laminated and built up on the work surface 1a of the work table 1 in the pattern of the command data Noi, and becomes the i-th data among the continuous multilayer cross-sectional data stored or calculated by the control device 7. The corresponding part will be restored.

Thereafter, the same operation is performed for the i1)-th data, and as a result, molten beads are successively deposited on the work table 1 in a predetermined pattern to form the target three-dimensional object, i.e. The three-dimensional object stored or calculated in the control device is restored on the work table l, and it is modeled.

In this case, the width and thickness of the molten bead depend on the type and amount of inorganic material powder supplied. plasma current plasma gas pressure,
It changes depending on the relative movement speed between the microtorch and the workbench. For example, increasing the plasma current will make the molten bead wider and thinner, improving wettability, and increasing the amount of powder supplied will make the molten bead wider and thicker. For this reason, it is necessary to appropriately set each of the above factors according to the shape and dimensions of the three-dimensional object to be modeled. This information is also input to the control device 7, and when a three-dimensional object is to be manufactured, the information is extracted as necessary and necessary operation commands are issued to other devices via each line.

For example, a mixed powder of Co alloy and CrlC1 is selected as the inorganic material powder, the plasma current is set to 50 to 70 A, and the control device 7 outputs annular multilayer cross-sectional data obtained by horizontally slicing a bottomed cylinder. When the cylinder was pulled out from its lower end and the moving device 2 was moved based on the data to perform the modeling process, it was possible to restore the bottomed cylinder that had been stored in the control device 7. (Effects of the Invention) As is clear from the above explanation, the apparatus and method of the present invention can directly form a desired shape from an inorganic material powder without using any cutting tool, mold, or binder. It is possible to create three-dimensional objects.

In addition, even if a three-dimensional object has a complex shape, the partial shape such as its cross-sectional shape can be analyzed and the desired three-dimensional object can be reconstructed and molded based on the analysis data, which is effective for manufacturing various molds and precision parts. It is.

Furthermore, since it can be applied to any material that can be melted with a plasma arc, there is a wide range of material selection. Can create three-dimensional objects.

[Brief explanation of the drawing]

FIG. 1 is a configuration diagram showing an embodiment of the present invention.

Claims (2)

[Claims] (1) Store or calculate the build-up data for each part of the three-dimensional object to be modeled in advance, supply powder of inorganic material to a plasma torch to form a molten bead, and apply it to either the plasma torch or the work table or A three-dimensional object manufacturing method, characterized in that a three-dimensional object is formed by moving both parts relative to each other in three dimensions based on the overlay data, and sequentially spraying and overlaying the molten bead onto the work table. . (2) Work table: Plasma that is arranged opposite to the work table and connected to a plasma power supply device and an inorganic material powder supply device to thermally spray and overlay the molten bead of the inorganic material onto the work table. torch; a moving device that moves at least one or both of the work table and the plasma torch three-dimensionally relative to each other; An operation signal for sequentially spraying and overlaying the molten bead of the inorganic material from the plasma torch onto the work table while moving the moving device based on command data to form the three-dimensional object on the work table. A three-dimensional object modeling device comprising: a control device that transmits a signal.