JP3433158B2 - Stereolithography - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a stereolithography apparatus for irradiating a layer of a photocurable resin with light to cure and stack the resin layers to form a stereolithographic object having a predetermined three-dimensional shape. is there.

[0002]

2. Description of the Related Art Conventionally, in the process of developing various products such as electric appliances, a three-dimensional model of the product has been made to check the design and operation, but with the recent shortening of the product life cycle. Therefore, it is necessary to produce a three-dimensional model in a shorter period of time. Therefore, a stereolithography apparatus has been developed for molding a three-dimensional object by irradiating the surface of the photocurable resin bath in the resin bath with laser light to cure the photocurable resin (US Pat. No. 4,575). , 3
No. 00, Tokuhei 5-18704, etc.)

However, the above-described stereolithography apparatus has a problem that the apparatus becomes large because a resin tank is required. Therefore, a stereolithography apparatus that does not require a resin tank has been proposed (Japanese Patent Publication No. 7-90603). In the stereolithography apparatus shown in FIG. 6, at the position below the stage (1) having the light transmission part (11),
The light irradiation device (4) is arranged facing upwards and the stage
A table (3) which is driven to move up and down by an elevating mechanism (20) is provided above the position (1). A lifting drive circuit (21) is connected to the lifting mechanism (20). The operations of the light irradiation device (4) and the elevation drive circuit (21) are controlled by the optical molding control device (8).

Further, a recoater (7) capable of horizontally reciprocating along the surface of the stage (1) is provided above the stage (1), and the recoater (7) has a pump (51). Via the resin supply pipe (54) in which the resin supply tank (5)
Are connected. The recoater (7) is a resin supply tank
A nozzle (not shown) for ejecting the photocurable resin supplied from (5) is provided, and the photocurable resin ejected from the nozzle onto the upper surface of the stage (1) is evened to a uniform thickness. It is equipped with a leveling plate (not shown).

In the above stereolithography apparatus, the table (3)
Is moved to a position higher than the recoater (7), the photocurable resin is discharged from the recoater (7) onto the upper surface of the stage (1), and the recoater (7) is reciprocally moved in the horizontal direction. Level the curable resin to a uniform thickness. After that, the table (3) is lowered and the table (3) or table
Add the layered product (60) formed on the back side of (3) to the stage (1)
The uncured resin layer on the upper side is brought into contact with the uncured resin layer, and in this state, light is emitted from the light irradiation device (4) to irradiate the uncured resin layer on the stage (1). At this time, the light irradiation region is determined based on the contour line data of the stereolithography object to be molded. Excessive photo-curable resin on the stage (1) is the resin return pipe (55).
After that, it returns to the resin supply tank (5). After the photocurable resin is cured, the table (3) is again raised to a position higher than the recoater (7), and the photocurable resin is supplied, leveled, and irradiated with light repeatedly. As a result, the cured resin layers are sequentially laminated on the back surface of the table (3), and finally, a desired three-dimensional laminated molded article is completed.

[0006]

However, in the stereolithography apparatus shown in FIG. 6, the recoater (7) is horizontally reciprocated as indicated by an arrow A in the figure to make the uncured resin tank have a uniform thickness. Not only is it necessary to level the table (3), but because of this, the table (3) is in a lowered position closer to the stage (1) and a higher lift than the recoater (7), as indicated by the arrow B in the figure. Since it is necessary to reciprocate greatly between the position and the position, there is a problem that the modeling time becomes long.
Further, a mechanism for reciprocating the recoater (7) is required, and since a tall lifting mechanism (20) is required for the reciprocating movement of the table (3), the optical modeling apparatus is complicated. so,
There was a problem that it became large.

Therefore, an object of the present invention is to shorten the molding time,
An object of the present invention is to provide a stereolithography apparatus capable of simplifying and downsizing the apparatus.

[0008]

A stereolithography apparatus according to the present invention comprises a stage (1) capable of transmitting light at least in a central portion,
At the lower position of the stage (1), the light transmission part (1
A light irradiation device (4) arranged toward (1) and irradiating light to a region corresponding to contour line data representing a three-dimensional shape of a stereolithography object.
A table (3) arranged above the stage (1) and having a resin supply hole (31) opened on the back surface;
An elevating mechanism (2) for elevating and lowering one of the table (1) and the table (3) toward and away from the other;
(2) and an optical molding control device (8) for controlling the operation of the light irradiation device (4), and a resin supply device for supplying uncured resin to the resin supply hole (31) of the table (3), Table (3)
Alternatively, a cured resin layer (6
Fill uncured resin (64) between 2) and stage (1),
An uncured resin layer (65) having a predetermined thickness is formed, and light is applied to the resin layer (65) in the entire region corresponding to the contour line data except the central region connected to the resin supply hole (31). The cured resin layer (62) is laminated by repeating the operation of irradiating with (3) to form a layered product (6) having a predetermined three-dimensional shape.

In the above-described stereolithography apparatus of the present invention, first, a space having a thickness larger than the stacking thickness (stacking pitch) is provided between the table (3) and the stage (1), and an optical space is provided in the space. Fill with curable resin. Here, the photocurable resin of the resin supply device is supplied to the space from the resin supply hole (31) of the table (3). After that, the table (3) is brought close to the stage (1), and the photocurable resin is compressed by matching the distance between the table (3) and the stage (1) with a predetermined stacking thickness (stacking pitch). An uncured resin layer having a predetermined laminated thickness is formed.

In this state, when light is emitted from the light irradiation device (4), the light passes through the light transmission part (11) of the stage (1) and is transmitted to the uncured resin layer on the stage (1). Is irradiated. At this time, the light irradiation area is determined according to the contour line data of the stereolithography object. That is, the light irradiation area is an area excluding the central area connected to the resin supply hole (31) from the entire area corresponding to the contour line data. As a result, the uncured resin layer on the stage (1) is cured in the light irradiation area, and the cured resin layer adheres to the back surface of the table (3). The central region of the uncured resin layer is not irradiated with light and remains uncured.

Next, the table (3) is separated from the stage (1), a space similar to the above is provided between the cured resin layer attached to the back surface of the table (3) and the stage (1), and the space is provided. Fill with a photocurable resin. At this time, in the central portion of the cured resin layer attached to the back surface of the table (3),
An uncured resin portion connected to the resin supply hole (31) is formed, and since the photocurable resin can pass through this area, it is supplied to the resin supply hole (31) of the table (3). The photo-curable resin will be supplied to the space through the area.

Thereafter, similarly, the table (3) is staged.
The photo-curable resin is compressed by bringing the cured resin layer attached to the back surface of the table (3) and the stage (1) closer to (1) so as to have a predetermined laminated thickness, thereby compressing the photo-curable resin. An uncured resin layer having is formed, and a region of the uncured resin layer corresponding to the contour line data is irradiated with light. In this case as well, the region except the central region connected to the resin supply hole (31) from the entire region corresponding to the contour line data becomes the light irradiation region, and the uncured resin layer on the stage (1) is exposed to light. The irradiated area is cured and the cured resin layer adheres to the first cured resin layer. Further, since the central region of the uncured resin layer is not irradiated with light and remains uncured, the supply path of the photocurable resin in the next step is secured. Thereafter, in the same manner, by repeating the supply of the photocurable resin, compression (leveling), and light irradiation treatment, finally, a layered molded article having a predetermined three-dimensional shape
(6) is obtained.

In a concrete configuration, a stereolithography control device (8)
Bring the table (3) relatively close to the stage (1) and bring the table (3) or the cured resin layer (62) formed on the back surface of the table (3) into contact with the stage (1). The table (3) is relatively separated from the stage (1) from the above state, and the table (3) or between the cured resin layer (62) formed on the back surface of the table (3) and the stage (1). And a resin filling step of filling the uncured resin (64) with the table (3) relative to the stage (1),
A resin compression step of compressing the uncured resin (64) into an uncured resin layer (65) having a predetermined laminated thickness, and a light to be irradiated to the uncured resin layer (65) according to the contour line data. The light irradiation area determination step of determining the area and the light irradiation step of applying light to the determined light irradiation area are repeatedly performed.

According to the above specific structure, the table (3) or the cured resin layer (62) formed on the back surface of the table (3).
When the table (3) is brought into contact with the stage (1), the table (3) is relatively separated from the stage (1) so that the cured resin layer (62) formed on the table (3) or on the back surface of the table (3). ) And the space formed between the stage (1) and the stage (1) become negative pressure, and the effect of sucking and filling the uncured resin (64) occurs, so that the uncured resin (64) does not need to be press-fitted. Become. Moreover, the space between the table (3) or the cured resin layer (62) formed on the back surface of the table (3) and the stage (1) is always filled with the photocurable resin without any gap. Therefore, there is no risk that air will be trapped, and as a result, it is possible to obtain a layered product that does not contain air bubbles.

Further, in a specific configuration, the stereolithography control device
(8) is the contour line for a plurality of resin layers constituting the layered product (6) in the light irradiation area determination step, including a first layer in contact with the back surface of the table (3). The light irradiation area is determined by removing the central area from the entire area according to the data, and the final layer farthest from the table (3) is irradiated with light without removing the central area from the entire area according to the contour line data. Determine the area. According to the specific configuration, a central hole (67) is opened in a plurality of layers including the first layer of the layered product (6), and the central hole (67) is closed by the final layer. .

Further, the stereolithographic article according to the present invention is manufactured by using the stereolithographic apparatus described above, and has a central hole (67) extending from one end to the other end in the stacking direction. It has been opened. As a result, it is possible to reduce the weight of the stereolithography object and save the photocurable resin.

Specifically, the central hole (67) is open at one end in the stacking direction and closed at the other end. Therefore, the stereolithography object having the specific configuration is such that the one end portion is the leg portion and the other end portion is the head portion, so that the opening of the central hole (67) is hidden by the leg portion. Since it becomes inconspicuous, it is advantageous in appearance.

[0018]

According to the stereolithography apparatus of the present invention, by compressing the photocurable resin between the stage or the cured resin layer attached to the back surface of the table or the stage,
Since the resin layer having a uniform thickness is formed, the recoater equipped in the conventional stereolithography apparatus is unnecessary. Further, by omitting the recoater, the relative movement distance of the table with respect to the stage is greatly shortened, and as a result, the elevating mechanism needs only a short elevating distance. Therefore, it is possible to shorten the modeling time, simplify the apparatus, and reduce the size of the apparatus as compared with the conventional apparatus.

[0019]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be specifically described below with reference to the drawings. In the stereolithography apparatus according to the present invention, as shown in FIG. 1, a projector type light irradiating device (4) is arranged upward at a position below a stage (1) having a light transmitting portion (11), stage
A table (3) which is driven up and down by a lifting mechanism (2) is provided above the position (1). A lifting drive circuit (21) is connected to the lifting mechanism (2). The operations of the light irradiation device (4) and the elevation drive circuit (21) are controlled by the optical molding control device (8).

Further, the table (3) is provided with a resin supply hole (31) for supplying a photocurable resin to the stage (1), and the resin supply hole (31) is provided in the resin supply hole (31). A nozzle (32) is connected to the nozzle (32), and a resin supply tank (5) is connected to the nozzle (32) via a resin supply pipe (52) in which a pump (51) is interposed. The stage (1) is connected to the resin supply tank (5) through the resin return pipe (53),
It is possible to return the excess uncured resin above (1) to the resin supply tank (5).

FIG. 2 shows a control procedure of the above-mentioned stereolithography control device (8). First, in step S1, after performing an initial operation required for various initial settings, step S1
At 2, the table (3) is lowered to the lowest surface position where it contacts the stage (1). Next, in step S3, the pump (5
1) is driven to start the supply of the photocurable resin, and in step S4, the table (3) is raised by a predetermined distance S (for example, 4 mm). As a result, table (3) and stage (1)
A space having a thickness S formed between is filled with a photocurable resin.

Next, in step S5, the table (3) is lowered by a predetermined distance so that the distance between the table (3) and the stage (1) matches a predetermined stacking thickness t (eg, 0.2 mm). Shrink to a distance. As a result, the uncured resin between the table (3) and the stage (1) is compressed to a predetermined laminated thickness. Then, in step S6, the shape of the cross section is drawn based on the contour line data in the cross section. Then, in step S7, it is determined whether or not the resin layer whose cross section is to be formed is the final layer, and if NO is determined, a mask corresponding to the layer number is drawn in step S8. For example, for a plurality of layers including the first layer attached to the table (3), a mask having a large area is drawn, and for the next plurality of layers (excluding the final layer), the mask area is gradually reduced. Then, an area excluding the mask shape from the cross-sectional shape is set as a light irradiation area. On the other hand, if YES is determined in step S7,
By bypassing step S8, the light irradiation region is set without removing the mask shape from the cross-sectional shape.

Then, in step S9, light is irradiated to the light irradiation region of the uncured resin layer. As a result, the uncured resin layer in the light irradiation region is cured, and the uncured resin layer in the region not exposed to light is not cured. Therefore, an uncured resin portion corresponding to the shape of the mask is formed in the central portion of the resin layer other than the final layer, and the uncured resin portion becomes the resin flow path in the next resin layer forming step. Of.

Thereafter, in step S10, it is determined whether or not light irradiation has been performed on all layers. If it is determined NO in step S10, the process returns to step S3 and step S3.
~ The procedure of S10 is repeated. Then, step S10
If YES is determined in step S11, the process proceeds to step S11, the table is saved, and the series of procedures ends.

FIG. 4 shows a stage in the above procedure.
The table (3) represents a process in which the table (3) gradually rises while repeatedly moving up and down with respect to (1).
First, resin is filled by raising the table (3) by a predetermined distance S from the state where the table (3) is in contact with the stage (1), and then the distance (S−t) obtained by subtracting the stacking thickness t from the predetermined distance S. The resin is compressed by descending only. By repeating this elevating operation, the layered product having the layer thickness t is gradually formed.

FIG. 3 shows how the layered product is gradually molded between the stage (1) and the table (3). As shown in FIG. 3A, a resin channel (61) penetrating vertically is formed in each cured resin layer (62), and the resin channel (61) is filled with an uncured resin (66). Has been done. By the suction force generated by raising the table (3) and the pumping force by the pump (51) as shown in FIG. 2B, between the lowest cured resin layer (62) and the stage (1), The uncured resin (64) is filled. Thereafter, the table (3) is lowered as shown in FIG. 3C, whereby the uncured resin (64) having the thickness S is compressed into the uncured resin layer (65) having the thickness t.

By irradiating the uncured resin layer (65) with light in this state, the uncured resin layer in the light irradiation region is cured to become a cured resin layer (62), and the center of the cured resin layer (62) is cured. A resin flow path (61) made of an uncured resin portion is formed in the portion.
In addition, a little uncured resin (63) remains around the cured resin layer (62) as shown in FIG.

FIG. 5 shows a vertical section of the layered product (6) molded in this way and horizontal sections at several vertical positions. As shown in the figure, a central hole (67) connected to the resin supply hole (31) of the table (3) is formed at the center of all the cured resin layers (62) except the final layer. The hole (67) is closed by the final cured resin layer (62). Therefore, the central hole (67) is opened on the contact surface of the layered product (6) with the table (3), but the surface on the final layer side can be finished to a curved surface without holes. . For example, when a bust of a person is formed, the surface of the head can be finished into a curved surface without holes by advancing the stacking from the chest to the head, which is preferable. The layered product (6) can be easily peeled off from the table (3).

According to the above-described stereolithography apparatus of the present invention, the space between the table (3) or the cured resin layer (62) attached to the table (3) and the stage (1) is always filled with the photocurable resin. Since the lamination is performed in this state, there is no risk that air will be trapped, and a laminated model (6) containing no bubbles can be obtained.
Further, by compressing the photocurable resin between the stage (1) and the cured resin layer (62) attached to the table (3) or the back surface of the table (3), a resin layer having a uniform thickness is formed. Therefore, the recoater (7) equipped with the conventional stereolithography equipment
Is unnecessary. Therefore, the device can be simplified. or,
Since it is not necessary to raise the table (3) high at the time of filling the resin, the elevating mechanism (2) needs only a short ascending / descending distance, which results in downsizing of the device. Further, the time required for moving up and down the table (3) is greatly shortened, and the modeling time can be shortened as compared with the conventional apparatus.

The configuration of each part of the present invention is not limited to the above embodiment, and various modifications can be made within the technical scope described in the claims. For example, in the above embodiment, a layered product
The central hole (67) of (6) merely has a function as a resin flow path and is formed to have a substantially uniform inner diameter, but the present invention is not limited to this, and the central hole (67) is formed in any shape in which the inner diameter changes greatly It is also possible to further enlarge the inner diameter of the central hole (67) according to the outer shape of the layered product (6) to finish the layered product (6) to a substantially uniform wall thickness. In this case, the mask shape described above may be expressed by a function of the layer number.

[Brief description of drawings]

FIG. 1 is a diagram showing a configuration of a stereolithography apparatus according to the present invention.

FIG. 2 is a flowchart showing a control operation of the optical modeling apparatus.

FIG. 3 is a diagram showing steps of filling, compression, and light irradiation with a photocurable resin.

FIG. 4 is a diagram for explaining a lifting / lowering operation of a table with respect to a stage.

FIG. 5 is a diagram illustrating a vertical cross section and a horizontal cross section of the layered product.

FIG. 6 is a diagram showing a configuration of a conventional stereolithography apparatus.

[Explanation of symbols]

(1) Stage (11) Light transmission part (2) Lifting mechanism (3) Table (31) Resin supply hole (4) Light irradiation device (5) Resin supply tank (6) Laminated model (61) Resin flow path (62) Cured resin layer (64) uncured resin (65) Uncured resin layer (67) Central hole (8) Stereolithography control device

Claims (3)

(57) [Claims] 1. A stereolithographic object having a predetermined stereoscopic shape is obtained by irradiating a layer of a photocurable resin with light to cure the resin layer based on contour line data representing the stereoscopic shape of the stereoscopic object, thereby forming a stereoscopic object having a predetermined stereoscopic shape. In an optical modeling apparatus to be manufactured, at least a central portion of the stage (1) is capable of transmitting light, and a light transmitting portion (1) of the stage (1) is provided below the stage (1).
A light irradiation device (4) which is arranged toward 1) and can irradiate light to a region corresponding to the contour line data, and a resin supply hole which is arranged above the stage (1) and opened on the back surface. A table (3) having (31), an elevating mechanism (2) for elevating and lowering one of the stage (1) and the table (3) toward and away from the other, an elevating mechanism (2) and The table (3) is composed of a stereolithography control device (8) for controlling the operation of the light irradiation device (4) and a resin supply device for supplying the uncured resin to the resin supply hole (31) of the table (3). Alternatively, the uncured resin (64) is filled between the cured resin layer (62) formed on the back surface of the table (3) and the stage (1) to form the uncured resin layer (65) having a predetermined thickness. Then, in the resin layer (65), light is irradiated to a region excluding the central region connected to the resin supply hole (31) from the entire region corresponding to the contour line data. By repeating the operation that, cured resin layer (62) laminated, optical shaping apparatus, characterized by shaping the laminate shaped article having a predetermined three-dimensional shape (6). 2. The stereolithography control device (8) is configured such that the table (3) is brought relatively close to the stage (1),
(3) or the state where the cured resin layer (62) formed on the back surface of the table (3) is brought into contact with the stage (1),
The table (3) is relatively separated from the stage (1).
(3) or a resin filling step of filling the uncured resin (64) between the cured resin layer (62) formed on the back surface of the table (3) and the stage (1), and then the table (3) Bring the uncured resin (6
Resin compression step of compressing 4) into an uncured resin layer (65) having a predetermined laminated thickness, and light that determines the area of light to be applied to the uncured resin layer (65) according to the contour line data. The stereolithography apparatus according to claim 1, wherein the irradiation area determination step and the light irradiation step of irradiating the determined light irradiation area with light are repeatedly performed. 3. The photolithography control device (8), in the light irradiation region determining step, firstly contacts the back surface of the table (3) among a plurality of resin layers that should constitute the laminate molding (6). For a plurality of layers including layers, the light irradiation region is determined by removing the central region from the entire region according to the contour line data,
The stereolithography apparatus according to claim 2, wherein a light irradiation area is determined for the final layer farthest from the table (3) without removing the central area from the entire area corresponding to the contour line data.