JPH07329190A - Manufacture of 3-dimensional object and manufacturing equipment - Google Patents

Abstract

PURPOSE:To shorten required time by recognizing a maximum length direction in which a distance between two optional points in the contour line of two-dimensional data is maximum, and scanning light in parallel with said maximum length direction. CONSTITUTION:This method for manufacturing a three-dimensional object comprises repeating the step of forming a thin film by emitting light to the surface of a liquid photocurable resin and applying the liquid photocurable resin thinly to the upper surface of the thin film. The manufacturing equipment is equipped with a bath 2 for storing the liquid photocurable resin R which cures by light irradiation and a molding frame 3 which an ascend/descend in the bath 2. In addition, the light L is selectively emitted by focusing it to the surface Ro of the liquid photocurable resin R. Further, the manufacturing equipment is equipped with a doctor blade 4 as a smoothing member sliding horizontally in such a manner that it strokes the surface Ro of the liquid photocurable resin R. The scanning direction of the light L runs parallel with a maximum length direction in which a distance between two optional points in the contour line of three-dimensional data is maximum.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is generated by dividing three-dimensional shape data of a three-dimensional model designed by three-dimensional CAD or three-dimensional shape data measured by a three-dimensional shape measuring instrument into multiple layers on a horizontal plane. A plurality of two-dimensional data are selected in order, and the surface of the liquid photo-curable resin is selectively irradiated with light based on each of the two-dimensional data selected in that order to form a resin thin film one after another. The present invention relates to a method and apparatus for manufacturing an original object, and in particular, it is intended to shorten the manufacturing time of a three-dimensional object by appropriately selecting the scanning direction of the light.

[0002]

2. Description of the Related Art A technique itself for producing a three-dimensional object having a desired shape by successively laminating thin films formed by selectively irradiating light on the surface of a liquid photocurable resin is well known. JP-A-61-1114818, JP-A-4-169221, JP-A-4-169222, JP-A-5-8307, and JP-A-5-38763.
It is disclosed in Japanese Patent Publication No.

[0003]

Although it is possible to manufacture a three-dimensional object having a desired shape even with the conventional technique disclosed in the above publications, the thickness of each thin film is usually equal to that of the conventional technique. Since it was a relatively thin film of 0.1 mm to 0.5 mm,
In order to manufacture an object of a certain size, a large number of thin films have to be laminated, which causes a problem that the manufacturing time becomes long.

Therefore, various efforts have been made to reduce the manufacturing time, for example, the above-mentioned Japanese Patent Laid-Open No. 61-1148.
In the technique disclosed in Japanese Patent No. 18, the time required to smooth the liquid photo-curable resin that newly covers the upper surface of the thin film generated by selectively irradiating the surface of the liquid photo-curable resin with light. It has been developed for the purpose of shortening the length of the liquid photocurable resin, and a brief explanation is that a smooth plate having a length corresponding to the width of the bath is placed on the bath containing the liquid photocurable resin, and the bath is inserted from the resin supply port. It has a structure in which the smooth plate is horizontally moved so as to stroke the liquid photocurable resin supplied therein. With such a structure, even if the liquid photocurable resin has a high viscosity (usually about 5 to 200 poise), its surface can be smoothed within a relatively short time. It was possible to reduce the total time required to manufacture the original object.

However, the effect of shortening the required time has not reached a level that can be fully satisfied, and there has been a demand for the development of a technique capable of further reducing the required time.
The present invention has been made in view of such a point, and an object of the present invention is to provide a manufacturing method and a manufacturing apparatus of a three-dimensional object capable of further shortening the required time.

[0006]

In order to achieve the above object, the invention according to claim 1 forms a thin film by selectively irradiating the surface of a liquid photocurable resin with light based on two-dimensional data. In the method of manufacturing a three-dimensional object having a desired shape by repeatedly performing a thin film forming step of, and a thin film coating step of thinly covering the upper surface of the thin film with the liquid photocurable resin, on the contour line of the two-dimensional data. The maximum length direction in which the distance between any two points becomes maximum is recognized, and the light is scanned in parallel with the maximum length direction.

On the other hand, in order to achieve the above object, the invention according to claim 2 is a light irradiating means for selectively irradiating the surface of a liquid photocurable resin with light based on two-dimensional data to form a thin film. And a thin film coating means for thinly coating the upper surface of the thin film with the liquid photo-curable resin, the distance between any two points on the contour line of the two-dimensional data is maximum. The maximum length direction and the scanning direction of the light were matched.

[0008]

In the invention according to claim 1 and claim 2,
When the scanning direction of the irradiated light is parallel to the maximum length direction in which the distance between any two points on the contour line of the two-dimensional data is the maximum, a scanning direction that is not parallel to the maximum length direction is selected. Compared with, the length of one scanning line becomes longer and the number of scanning lines becomes smaller.

When the number of scanning lines is reduced, the number of transitions from one scanning line to the next scanning line is reduced, and the number of times of stopping, moving and driving the mechanism for scanning light is reduced. The time required for stopping, moving and driving due to the motion characteristics of the scanning mechanism is shortened.

[0010]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a diagram showing the configuration of a three-dimensional object manufacturing apparatus 1 according to the first embodiment of the present invention. This three-dimensional object manufacturing apparatus 1 is a liquid photocurable resin R that is cured by being irradiated with light. A bath 2 accommodating the same, a molding stand 3 that can be moved up and down in the bath 2, and a predetermined scanning with the light L by focusing on the surface R ₀ of the liquid photocurable resin R which is arranged above the bath 2. It comprises a light irradiation device as a light irradiation means capable of irradiating along the direction, and a doctor blade 4 movable horizontally so as to stroke the surface R ₀ of the liquid photocurable resin R.

Of these, the light irradiator is, for example, H
A known optical scanning device composed of an e-Cd laser, a collimation lens, a cylindrical lens, a polygon mirror, a toroidal lens, a converging lens and the like is applied. In the direction (Y-axis direction) orthogonal to the scanning direction (X-axis direction) of the light L emitted from the light irradiating device, for example, the entire light irradiating device or the entire bath 2 is provided with its Y-axis. By moving in the direction, the irradiation range of the light L can be expanded. That is, the scanning line of the light L emitted from the light emitting device is parallel to the X-axis direction,
The scanning lines are sequentially arranged in the Y-axis direction, and by turning on / off the light L corresponding to the two-dimensional data during scanning, only the plane area corresponding to the two-dimensional data is selected. It can illuminate light.

The molding frame 3 is made of a liquid photocurable resin R.
It has an upper surface 3a parallel to the surface R _{0 of the above,} and can be displaced to any position in the vertical direction in the bathtub 2 by an elevating device (not shown). The doctor blade 4 is a flat plate-shaped member having a width slightly shorter than the width of one side (the direction orthogonal to FIG. 1) of the bathtub 2, and the tip 4a formed at an acute angle has a surface R _{0 of the} liquid photocurable resin R. It is hung vertically so as to slightly contact with, and is driven by a driving device (not shown) along the surface R ₀ in the lateral direction of FIG. 1 (thickness direction of the doctor blade 4) to substantially the entire widthwise direction of the bathtub 2. It is possible to move across.

The basic operation for manufacturing a three-dimensional object having a desired shape by the three-dimensional object manufacturing apparatus 1 will be described with reference to FIG.
A description will be given together with (a) to (d). That is, as shown in FIG. 2A, the molding frame 3 is moved to an initial position where a thin layer (about 0.1 mm to 0.5 mm) of the liquid photocurable resin R is formed on the upper surface 3a thereof. While maintaining this state, the liquid photo-curable resin R is cured by selectively irradiating the light L from the light irradiation device to form the thin film 5a on the upper surface 3a (thin film forming step). In the scanning of the light L emitted from the light irradiation device, a plurality of two-dimensional data generated by dividing the three-dimensional shape data of the desired shape into multiple layers on the horizontal plane are sequentially selected from the lowermost layer side, and the selected one is selected. It is performed based on only one two-dimensional data. The three-dimensional shape data is generated by designing by three-dimensional CAD or measuring an actual object with a three-dimensional shape measuring instrument or the like.

When the lowermost thin film 5a is formed, as shown in FIG.
As shown in (b), the molding frame 3 is lowered by a predetermined distance. The descending distance of the molding pedestal 3 corresponds to the thickness of the thin films formed one after another (about 0.1 mm to 0.5 mm). Immediately after the molding pedestal 3 is lowered, the surface tension of the liquid photo-curable resin is large and the descending distance of the molding pedestal 3 is very small. Therefore, as shown in FIG. The surrounding liquid photocurable resin does not enter the surface.

Therefore, in this embodiment, after the molding frame 3 is lowered by a predetermined distance, the doctor blade 4 is moved at a predetermined speed so as to stroke the surface R ₀ (thin film coating step).
Then, as shown in FIG. 2C, the doctor blade 4
Since the liquid photo-curable resin R moves so as to be dragged to the tip 4a of the liquid photo-curable resin R, the liquid photo-curable resin R also enters the thin film 5a, and a thin layer of the liquid photo-curable resin R is formed on the thin film 5a. The doctor blade 4 evens out fine irregularities on the surface R ₀ , and the surface R ₀ is substantially smoothed when the movement of the doctor blade 4 is completed. In other words, immediately after lowering the molding frame 3, the doctor blade 4
By moving the surface R of the liquid photocurable resin R
The time until ₀ is smoothed is greatly reduced.

When the surface R ₀ is smoothed, as shown in FIG. 2D, the liquid photo-curable resin R is cured by selectively irradiating the light L from the light irradiator again to cure the liquid photo-curable resin R on the thin film 5a. The thin film 5b in the next stage is formed (thin film forming step). At this time, the scanning of the light L emitted from the light irradiation device is performed based on the upper two-dimensional data of one two-dimensional data selected when the thin film 5a of the lowermost layer is formed.

After the thin film 5b is formed, the molding frame 3 is lowered again by a predetermined distance as in FIG.
Move the doctor blade 4 in the same manner as in (c), and
Similarly to (d), the light L is selectively emitted, and then again shown in FIG.
Similar to (b), the molding pedestal 3 is lowered by a predetermined distance, and so on, and the operations shown in FIGS. 2B to 2D are repeatedly executed.

Then, since the thin films 5a, 5b, ... Are successively laminated on the upper surface 3a of the molding frame 3, the above-mentioned three-dimensional shape data is divided into multiple layers on a horizontal plane to generate two-dimensional data. The molding of the three-dimensional object having the desired shape is completed when the above-described repeated operation is performed for all of them. Next, a specific scanning of the light L when forming the thin films 5a, 5b ... Will be described.

That is, the contour line C of the two-dimensional data referred to when the light irradiation device irradiates the light L, and the X axis (scanning direction of the light irradiation device) and the Y axis (direction orthogonal to the X axis). It is assumed that the relationship is as shown in FIG. By the way,
In the case of the conventional device, regardless of the shape of the contour line C, FIG.
The light L was scanned in parallel with the X-axis as indicated by a plurality of parallel solid lines, but this increases the number of scanning lines as described above, which increases the manufacturing time.

On the other hand, in the present embodiment, the maximum length direction in which the distance between any two points on the contour line C becomes maximum is recognized, and the maximum length direction is made parallel to the X axis. By performing coordinate conversion of the two-dimensional data, the maximum length direction and the scanning direction are made to coincide with each other, and the number of scanning lines is reduced. Although various methods are conceivable for recognizing the maximum length direction, the simplest method is, as shown in FIG. 4, the center of gravity G (x _G , y of the region surrounded by the contour line C.
_G ), and each point (x _n ,
distance to _{n n} ) L _n (= {(x _G −x _N ) ² + (y _G
-Y _n ) ² } ^1/2 ) is calculated, and the maximum value L _max of each distance L _n is searched. The center of gravity G and its maximum value L
The direction of the straight line M connecting the point (x _max , y _max ) that takes _max is the maximum length direction. The subscript n is a number appropriately assigned to each point, and n = 0, 1, 2, ..., N.

The center of gravity G of the area surrounded by the contour line C
As a method of obtaining (x _G , y _G ), for example, the contour line C
Based on each point (x _n , y _n ) above,

[0022]

[Equation 1]

A method of obtaining the value using the arithmetic expression As another method of obtaining the center of gravity G (x _G , y _G ), for example, the area surrounded by the contour line C is divided into triangles, and the areas of the respective triangles are set to A _{1 to} A _N, and the triangles are further divided. coordinates in the three vertices of the X-Y coordinate system _{(x 1, y 1: x} 2, y 2: x 3, y 3) Request. And based on each of these coordinate points,

[0024]

[Equation 2]

A method of obtaining the center of gravity G can be considered as
When a straight line M extending in the maximum length direction is obtained, an X ′ axis parallel to the straight line M and a Y ′ axis orthogonal to the X ′ axis are assumed, and the X ′ axis and the X axis coincide with each other. Coordinate conversion is performed on the two-dimensional data so that the Y ′ axis and the Y axis coincide with each other.
It should be noted that such coordinate conversion is performed by rotating the X ′ axis according to the angle between the X axis and the origin of the XY coordinates after the rotation and the X ′ axis.
-Y 'is a parallel movement according to the offset amount from the origin. However, the coordinate conversion for the two-dimensional data needs to have the same content for all of the plurality of two-dimensional data generated by dividing the three-dimensional shape data into multiple layers on the horizontal plane. The case where the maximum length direction is different for each two-dimensional data will be described later.

When such coordinate conversion is performed, the shape of the two-dimensional data remains unchanged, but the inclination and position in the XY coordinates are converted, and the maximum length direction is the X axis as shown in FIG. Will be parallel to. Then, when the light L is irradiated based on the converted two-dimensional data, the scanning direction thereof coincides with the maximum length direction. Therefore, as shown by a plurality of parallel solid lines in FIG. Is longer than that in the case of FIG. 3, but the number of scanning lines is smaller than that in the case of FIG.

Therefore, the total time required for scanning is not particularly shortened, but if the number of scanning lines is reduced, the operation of switching the irradiation range of the light L in the Y-axis direction is reduced, so that, for example, light The number of times of stopping, moving and driving the irradiation device or the bath 2 is reduced, the time required for stopping, moving and driving due to its motion characteristics is shortened, the manufacturing time of the three-dimensional object can be greatly shortened, and the production efficiency is improved. You can do it.

Depending on the shape of the three-dimensional object, the maximum length direction may differ for each two-dimensional data of each layer. In such a case, for example, the two-dimensional data having the largest area within the contour line. It is conceivable that the maximum length direction of is the scanning direction, or the maximum length direction is obtained for each two-dimensional data for each layer and the average thereof is used as the maximum length direction. Since the number of scanning lines required to complete the original object is smaller than that in the conventional case, the advantage that the manufacturing time of the three-dimensional object can be shortened is sufficiently obtained.

Further, in the above-mentioned embodiment, since the maximum length direction and the scanning direction are made to coincide with each other by appropriately converting the coordinates of the two-dimensional data, it is necessary to make the structure for scanning the light L particularly complicated. There is an advantage that it does not. In other words, since it is only necessary to apply simple arithmetic processing to the two-dimensional data, there is no significant increase in cost. FIG. 6 is a diagram showing the configuration of the three-dimensional object manufacturing apparatus 1 according to the second embodiment of the present invention. The same members and parts as those in the first embodiment are designated by the same reference numerals, and their duplicated description will be omitted.

That is, this embodiment is different from the first embodiment in that a new liquid photocurable resin R is replenished, and specifically, the doctor blade 4 is used.
Container 10 whose lower end can be opened on both front and rear sides in the forward and backward direction
A and 10B are attached and the container 10A, 1
A nozzle 11 capable of supplying the liquid photo-curable resin R to 0B is exposed to the bathtub 2, and a tray 12 for collecting the liquid photocurable resin R overflowing from the bathtub 2 is provided around the upper end of the bathtub 2. ing.

The method of using the three-dimensional object manufacturing apparatus 1 is as follows.
Basically the same as in the first embodiment, except that the edge of the bath 2 is filled with the liquid photo-curable resin R, that is, the height of the surface R ₀ of the liquid photo-curable resin R is the upper end of the bath 2. The three-dimensional object is manufactured in a state in which the parts match each other. And when moving the doctor blade 4,
The container 10A or 10B that moves horizontally in advance of the doctor blade 4 (that is, the doctor blade 4 is shown in FIG.
When moving from the right to the left, the lower end side of the container 10A, and when moving in the opposite direction, the lower end side of the container 10A is opened as shown by the broken line in FIG. 7, and is supplied from the nozzle 11 into the containers 10A and 10B. The liquid photocurable resin R that has been used is gradually replenished into the bath 2 from the lower end side opening of the container 10A or 10B.

With such a structure, when the doctor blade 4 moves along the surface R ₀ of the liquid photocurable resin R in the bath 2, the moving container 10A or 10B moves ahead of it. A new liquid photo-curable resin R is gradually replenished into the bath 2 from the above, and the replenished liquid photo-curable resin R is leveled by the doctor blade 4 which is moved immediately after the surplus liquid photo-curable resin R. Since R overflows from the bathtub 2 and is collected in the tray 12, the surface R
₀ can be surely smoothed. The tray 12
Since the liquid photocurable resin R collected in step 1 is reused,
There is no waste.

If the liquid photocurable resin R is not filled in the bathtub 2 and the liquid photocurable resin R is intensively replenished to a specific position in the bathtub 2 from the nozzle 11 or the like, The liquid photocurable resin R leaked laterally from the longitudinal end of the doctor blade 4 at the start of movement is the bath 2
To form a thick layer of the liquid photo-curable resin R, and the thick layer collapses inside the bath 2 after the doctor blade 4 has passed. It is likely that it will be thick,
With the configuration of the present embodiment, such a situation does not occur, so that the surface R ₀ can be smoothed with high accuracy.

Further, since the height of the surface R ₀ always coincides with the upper end of the bath 2, it is not necessary to correct the focus of the light emitted from the light irradiation device when forming the thin film. Moreover, since the containers 10A and 10B are provided on both sides of the doctor blade 4, the liquid photocurable resin R can be replenished to the front side of the doctor blade 4 regardless of the moving direction of the doctor blade 4. Therefore, there is no need to perform a wasteful operation of merely returning the doctor blade 4 to the predetermined position.

Also in this embodiment, the scanning direction of the light L by the light irradiation device is made to coincide with the maximum length direction of the two-dimensional data by the same method as in the first embodiment.
Therefore, other operational effects are similar to those of the first embodiment. In the first embodiment described above, the thin films 5a, 5b, ... Are stacked one after another while the molding frame 3 is lowered, and in the second embodiment, the liquid photocurable resin R is replenished while the molding frame 3 is lowered. However, the type of the three-dimensional object manufacturing apparatus 1 to which the present invention is applicable is not limited to these, and for example, the type disclosed in Japanese Patent Laid-Open No. 61-114818, that is, Forming the bottom thin film on the bottom surface of the bath 2 without providing a vertically movable molding base 3,
Then, a predetermined amount of the liquid photo-curable resin R is replenished, the doctor blade 4 is moved along the surface R ₀ thereof for smoothing, and light is irradiated to form a thin film of the next stage, and again a predetermined amount is formed. The liquid photo-curable resin R may be replenished, and so on, to form a three-dimensional object by laminating thin films one after another on the bottom surface of the bathtub 2.

[0036]

As described above, according to the invention of claim 1 or 2, since the light is scanned in parallel with the maximum length direction of the two-dimensional data, the number of scanning lines is small. Therefore, the manufacturing time of the three-dimensional object can be significantly shortened, and the production efficiency can be improved.

[Brief description of drawings]

FIG. 1 is a sectional view showing a configuration of a first embodiment of the present invention.

FIG. 2 is an explanatory diagram illustrating an operation of the first embodiment.

FIG. 3 is an explanatory diagram of two-dimensional data before coordinate conversion.

FIG. 4 is an explanatory diagram illustrating a method of coordinate conversion of two-dimensional data.

FIG. 5 is an explanatory diagram of two-dimensional data after coordinate conversion.

FIG. 6 is a sectional view showing a configuration of a second exemplary embodiment of the present invention.

FIG. 7 is an enlarged view of a main part of the second embodiment.

[Explanation of symbols]

1 3D Object Manufacturing Device 2 Bathtub 3 Molding Stand 4 Doctor Blade 5a, 5b Thin Film 10A, 10B Container R Liquid Photocurable Resin R ₀ Liquid Photocurable Resin Surface L Light

Claims (2)

[Claims] 1. A thin film forming step of selectively irradiating the surface of a liquid photocurable resin with light based on two-dimensional data to form a thin film, and a thin film covering the upper surface of the thin film with the liquid photocurable resin. In the method of manufacturing a three-dimensional object having a desired shape by repeatedly performing the thin film coating step, the maximum length direction in which the distance between any two points on the contour line of the two-dimensional data becomes maximum is recognized, and A method for manufacturing a three-dimensional object, comprising scanning the light parallel to a maximum length direction. 2. Light irradiation means for selectively irradiating the surface of the liquid photo-curable resin with light based on two-dimensional data to form a thin film, and the upper surface of the thin film is thinly covered with the liquid photo-curable resin. In the apparatus for manufacturing a three-dimensional object including a thin film coating means, a maximum length direction in which a distance between any two points on the contour line of the two-dimensional data is maximum is made to coincide with the scanning direction of the light. An apparatus for manufacturing a three-dimensional object characterized by the above.