JP2002036372A - Stereo lithographic apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To shorten a cycle time of a stereo lithography by effectively suppressing a precipitation or a deposition of filler or beads in a photosetting resin in a stereo lithographic apparatus for molding a stereoscopic molding of a predetermined shape by disposing an elevation table 2 in the resin in a resin tank 1, scanning a laser beam on a liquid surface of the resin and thereby laminating while curing the resin on the table 2. SOLUTION: The stereo lithographic apparatus comprises agitating fins 5 and 5 installed at a bottom of the resin tank 1 to reciprocate to move in cooperation with a reciprocating movement of a knife 3. In this apparatus, the fins 5 and 5 are reciprocated within a period except a scanning step of the laser beam, and the resin is agitated in a series of the steps of curing the resin for one layer part.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical molding apparatus for molding a three-dimensional object using a photocurable resin which is cured by irradiation with a laser beam.

[0002]

2. Description of the Related Art Conventionally, in the development process of various products such as electric devices, a three-dimensional model of the product is prepared and design and operation are checked. However, with the recent shortening of the product life cycle, Therefore, it is necessary to produce a three-dimensional model in a shorter time. Therefore, a laser beam is applied to the surface of the photo-curable resin in the resin tank to cure the photo-curable resin, whereby a stereolithography device for molding a three-dimensional molded object has been developed (U.S. Pat.No.4,575,300).
No., Tokuhei 5-18704).

In an optical shaping apparatus, as shown in FIG.
An elevating table (91) driven up and down by a driving mechanism (92) is horizontally arranged in the photocurable resin (90) in the resin tank (9), and above the resin tank (9), Laser oscillator (9
A projector (95) to which 4) is connected is provided, and laser light emitted from the projector (95) is applied to the photocurable resin (90) on the lifting table (91). The control device (93) is connected to the projector (95), and the scanning operation of the laser beam is controlled. This allows the lifting table
The photocurable resin (90) on (91) is laminated while being cured, and a three-dimensional structure (96) having a predetermined shape is formed.

By the way, in order to increase the strength and heat resistance of a three-dimensional structure, a filler or beads made of glass, ceramic, or the like is mixed in a photocurable resin. In stereolithography using such a photocurable resin,
Fillers and beads gradually settle and accumulate on the bottom of the resin tank during the molding period for molding one three-dimensional object, and if left undisturbed, it becomes difficult to remove them. Further, a state in which the resin concentration differs between the surface layer portion and the bottom layer portion in the resin tank may occur, which may hinder the quality of the three-dimensional structure.

Therefore, in the conventional stereolithography apparatus, after the stereolithography is completed, a resin stirrer (98) having a screw (99) is installed in a resin tank (9) as shown in FIG. By rotating (99), the photocurable resin (90) was agitated to prevent sedimentation and accumulation of fillers and beads.

FIG. 10 shows the steps of a stereolithography operation in a conventional stereolithography apparatus. First, after forming conditions are set in step S11, in step S12, the elevating table is lowered by one layer, and then in step S1
In 3, the knife for leveling the surface of the photocurable resin is moved in the horizontal direction. After that, in step S14, scanning by laser light is performed, and photo-curing for one layer is performed. Next, it is determined in step S15 whether or not all the laminations have been completed. If the determination is no, the process returns to step S12 to repeat the lowering of the table and the laser scanning. When the determination is YES in step S15, the process proceeds to step S16, in which the knife is moved to the initial position. Then, the table is raised in step S17, and the three-dimensional structure is removed from the table in step S18. Remove and complete stereolithography. Then, step S19
Then, a resin stirrer is attached to the resin tank, and step S2
Perform stirring operation at 0.

[0007]

However, in the stereolithography using the conventional stereolithography apparatus, during the period from step S11 to step S19 shown in FIG. 10, the sedimentation and deposition of fillers and beads progress in the resin tank. Therefore, the stirring operation in the subsequent step S20 required a long time of half a day or more. As a result, there is a problem that the cycle time of the optical shaping becomes long.

An object of the present invention is to provide a stereolithography apparatus capable of effectively suppressing the settling and deposition of fillers and beads and shortening the stereolithography cycle time.

[0009]

According to the present invention, there is provided an optical shaping apparatus comprising: an elevation table in a photocurable resin (10) in a resin tank (1);
(2) is arranged, and the liquid surface of the photo-curable resin (10) is scanned with a laser beam to thereby raise and lower the table (2).
The above photocurable resin (10) is laminated while being cured to form a three-dimensional molded article having a predetermined shape, and a stirrer is installed at the bottom of the resin tank (1). The stirrer is operated during a period excluding a scanning step using a laser beam during a series of steps for curing one layer of the photocurable resin (10).

Since the stereolithography apparatus of the present invention has a structure in which the stirrer is installed at the bottom of the resin tank (1), the stereolithography is performed while the stirrer is installed in the resin tank (1). It is possible to operate the stirrer within a period except for a scanning step using a laser beam during the series of steps,
Stir the inside of the resin tank (1). As a result, sedimentation and accumulation of fillers and beads are suppressed. Further, as described above, during the scanning by the laser beam, the operation of the stirring device is stopped, so that the liquid level of the photocurable resin (10) does not undulate, and as a result, a three-dimensional structure with high accuracy is obtained. .

In a first specific configuration, the optical shaping apparatus comprises a knife (3) reciprocally driven along the surface of the photocurable resin (10), and the stirring device comprises a reciprocating knife (3). The stirring fin (5) reciprocates along the bottom surface of the resin tank (1) in conjunction with the movement. According to the specific configuration,
Since the stirring fin (5) is simultaneously reciprocated by the drive mechanism for reciprocating the knife (3), a dedicated drive mechanism for the stirring fin is not required. Thus, in the resin tank (1),
Since there is no need to provide a dedicated drive mechanism for the stirring fin,
The mechanism for reciprocating the stirring fin (5) is simplified, and the stereolithography process can be performed while the stirring fin (5) is provided at the bottom of the resin tank (1).

Here, the stirring fin (5) is formed in an arc shape whose cross section is directed obliquely upward, and a pair of stirring fins (5).
(5) (5) is deployed back to back. As the one stirring fin (5) facing obliquely upward moves in one direction, the photocurable resin (10) at the bottom of the resin tank is scooped up by the stirring fin (5). A swirling flow is induced in the curable resin (10). Next, the other agitating fin (5) in back-to-back movement in the opposite direction induces a swirling flow in the opposite direction. Due to the generation of these swirling flows, the photocurable resin (10) is sufficiently stirred.

In a second specific configuration, the stirring device includes a belt (71) stretched along the bottom surface and both inner side surfaces of the resin tank (1), and a protruding member provided on the surface of the belt (71). One or more stirring plates (7), and a driving mechanism installed outside the resin tank (1) to reciprocate the belt (71) along the bottom surface and both inner side surfaces of the resin tank (1). It has. In this specific configuration, the belt (71) and the agitating plate (7) move along the bottom surface and both inner side surfaces of the resin tank (1), whereby the resin tank (1) is moved.
Convection occurs in the photocurable resin (10) in (1), and the photocurable resin (10) is sufficiently stirred. According to the specific configuration,
A drive mechanism is provided outside the resin tank (1).
(1) In the belt along the bottom and both inner sides (71)
The belt (71) and the stirring plate (7) are connected to the resin tank (1) because only the stirring plate (7) is protruded from the belt.
It is possible to carry out the optical shaping process while being provided at the bottom of the.

The belt (7) is provided above the resin tank (1).
Spatula for scraping off the photocurable resin (10) attached to 1)
(74) has been deployed. This prevents the photocurable resin (10) in the resin tank (1) from leaking to the outside with the movement of the belt (71).

In a third specific configuration, the stirring device is provided with a stirring roller (8) rotatably disposed on the bottom surface of the resin tank (1), and provided outside the resin tank (1). Stirring roller
And (8) an electromagnetic drive device (81) for reciprocatingly driving the (8) along the bottom surface of the resin tank (1). In this specific configuration, the stirring roller (8) disposed on the bottom surface of the resin tank (1) receives the electromagnetic force from the electromagnetic driving device (81) and reciprocates along the bottom surface, whereby the light The curable resin (10) is stirred. According to the specific configuration, the electromagnetic driving device is provided outside the resin tank (1).
(81) is provided, and only the stirring roller (8) is disposed on the bottom surface of the resin tank (1), so that the optical shaping process can be performed in this state.

Here, the stirring device further includes a second stirring roller (82) rotatably disposed on the inner surface of the resin tank (1),
A second electromagnetic drive (83) is provided outside the resin tank (1) and drives the stirring roller (82) back and forth along the inner surface of the resin tank (1). Thereby, a horizontal flow is induced by the first stirring roller (8) in the photocurable resin (10) in the resin tank (1), and at the same time, the second stirring roller (82) is induced. This induces a flow in the vertical direction, and the photocurable resin (10) is sufficiently stirred.

[0017]

In the stereolithography apparatus according to the present invention, even when fillers or beads are mixed in the photocurable resin, the stirrer operates during the stereolithography process, and the photocurable resin is hardened. Since the resin is sufficiently stirred, sedimentation and deposition of fillers and beads are effectively suppressed. As a result, stirring after the completion of stereolithography becomes unnecessary, and the cycle time of stereolithography can be shortened.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below.
The description will be made specifically with reference to the drawings.First embodiment  As shown in FIG. 1, the optical shaping apparatus of the present embodiment has a resin tank (1)
A lifting table (2) is provided inside the
(2) is connected to the lifting mechanism (6) as shown in FIG.
Is reciprocated. Filler and resin are contained inside the resin tank (1).
Photo-curable resin (10) mixed with
You.

A laser irradiation device (4) and a scanner mirror (41) are provided above the resin tank (1) as shown in FIG. 1, and a laser beam (42) emitted from the laser irradiation device (4) is provided. Elevated table reflected by the scanner mirror (41)
(2) Scan the upper photocurable resin. In addition, resin tank (1)
A pair of horizontal guide rails (11) and (11) are disposed at the upper part of the knife, and both ends of the knife (3) are engaged with the guide rails (11) and (11). By knife (3)
Is reciprocated in the horizontal direction. Thereby, the surface of the photocurable resin (10) to be irradiated with the laser beam is leveled.

The bases of a pair of support arms (51, 51) are fixed to the output of the drive mechanism of the knife (3).
(51) The lower end of (51) extends to the bottom of the resin tank (1), and a pair of stirring fins (5) (5) is attached to the lower end. Therefore, the stirring fins (5) (5) reciprocate in conjunction with the reciprocation of the knife (3). Both stirring fins
(5) and (5) each have an arc shape with a cross-sectional shape facing obliquely upward, and are arranged back to back.
Therefore, when moving to the left, the left stirring fin (5) scoops up the photocurable resin at the bottom of the resin tank as shown by the broken line in FIG. 1, and when moving to the right, the right stirring fin (5). Scoops the photocurable resin at the bottom of the resin tank and induces a swirling flow in the photocurable resin. Thereby, the photocurable resin is sufficiently stirred.

In the stereolithography apparatus of this embodiment, a resin tank
A pair of stirring fins (5) and (5) are provided at the bottom of (1), and the stirring fins (5) and (5) obstruct the vertical movement of the lifting table (2) and the horizontal movement of the knife (3). Therefore, the stereolithography process can be performed without removing the stirring fins (5) from the resin tank (1).

FIG. 5 shows a stereolithography process in the stereolithography apparatus. First, after forming conditions are set in step S1, in step S2, the elevating table is lowered by one layer, and then in step S3, the knife is moved in the horizontal direction. Accordingly, the pair of stirring fins move (Step S4). After that, in step S5, scanning with laser light is performed, and 1
Light curing is performed for the stacked layers. Next, it is determined in step S6 whether or not all the laminations have been completed. If the determination is no, the process returns to step S2 to lower the table,
Repeat the laser scan. And when it is determined to be Yes in step S6, the process proceeds to step S7,
After moving the knife to the initial position, the table is raised in step S8, and the three-dimensional object is removed from the table in step S9, and the optical modeling is completed.

In the above-described stereolithography apparatus, during a series of stereolithography processes, only the sedimentation of fillers and beads occurs during the processing period of steps S2 and S5 in FIG. 5, so that the sedimentation amount is small. By the movement of the stirring fin in S4, its settling and deposition can be suppressed. Therefore, stirring after completion of modeling is unnecessary or minimal, and as a result, the cycle time of modeling can be shortened.

[0024]Second embodiment  In the stereolithography apparatus of the present embodiment, as shown in FIG.
A pair of left and right driving rollers (72) and (72) are arranged above the fat tank (1).
At the bottom of the resin tank (1), a pair of left and right driven
Rollers (73) and (73), and a belt (71) is placed between these rollers.
It is stretched. The belt (71) is made of stainless steel.
Metal sheet made of aluminum or aluminum, or tephro
Use a chemical-resistant sheet made of nylon (registered trademark), nylon, etc.
Can be. It also extends along the bottom of the resin tank (1).
In the center of the belt (71), a stirring plate (7) protrudes upward.
Have been. Further, each driving roller (72) is expanded in FIG.
As shown, the photocurable resin adhering to the belt (71)
A spatula (74) is provided for scraping the fat (10).

A driving roller (7) is driven by a motor not shown.
2) By rotating (72) forward and reverse, the belt (71)
Reciprocates along the bottom surface and both inner side surfaces of the resin tank (1), and the stirring plate (7) reciprocates along the bottom surface of the resin tank (1). Due to the reciprocating movement of the belt (71) and the stirring plate (7), convection occurs in the photocurable resin (10) in the resin tank (1), and the photocurable resin (10) is sufficiently stirred. .

In the stereolithography apparatus of this embodiment, a resin tank
A belt (71) and a stirring plate (7) are provided along the inner surface of (1), and the belt (71) and the stirring plate (7) are moved up and down a table.
Since there is no hindrance to the vertical movement and the horizontal movement of the knife in (2), the stereolithography process can be performed in this state.

FIG. 6 shows a stereolithography process in the stereolithography apparatus. First, after forming conditions are set in step S1, in step S2, the elevating table is lowered by one layer, and then in step S3, the knife is moved in the horizontal direction. Also, while the table is moving down and the knife is moving, the driving roller is driven to rotate to stir the photocurable resin (step S41). After that, in step S5, scanning by laser light is performed to perform photo-curing for one layer. Next, it is determined in step S6 whether or not all the laminations have been completed. If the determination is no, the process returns to step S2 to repeat the lowering of the table and the laser scanning. If the determination is yes in step S6, the process proceeds to step S7, in which the knife is moved to the initial position, the table is raised in step S8, and the three-dimensional structure is removed from the table in step S9. Remove and complete stereolithography.

In the above-mentioned stereolithography apparatus, during a series of stereolithography steps, only the sedimentation of fillers and beads occurs during the processing period of step S5 in FIG. 6, so that the amount of sedimentation is small. By driving, the sedimentation and deposition can be suppressed. Therefore, stirring after completion of modeling is unnecessary or minimal, and as a result, the cycle time of modeling can be shortened. Also a spatula
Depending on the equipment of (74), the photocurable resin (10) in the resin tank (1)
Is prevented from leaking outside due to the movement of the belt (71).

[0029]Third embodiment  In the stereolithography apparatus according to the embodiment of the present invention, as shown in FIG.
Agitating roller (8) along the bottom and side of resin tank (1)
(82) are arranged, and these stirring rollers (8) and (82)
Electromagnetic drives (81) and (83) provided outside the tank (1)
As well as going along the inner surface of the resin tank (1).
It is driven back. The reciprocating movement of both stirring rollers (8) and (82)
The photocurable resin (10) in the resin tank (1)
A flow in the direction perpendicular to the flow is induced, and this
As a result, the photocurable resin (10) is sufficiently stirred.

In the stereolithography apparatus of this embodiment, a resin tank
Stirring rollers (8) and (82) are provided on the bottom and side surfaces of (1), and the stirring rollers (8) and (82) hinder the vertical movement of the lifting table (2) and the horizontal movement of the knife. There is no
In this state, the stereolithography process can be performed.

FIG. 7 shows a stereolithography process in the stereolithography apparatus. First, after forming conditions are set in step S1, in step S2, the elevating table is lowered by one layer, and then in step S3, the knife is moved in the horizontal direction. Further, while the table is being lowered and the knife is being moved, the above-mentioned electromagnetic drive device is operated to stir the photocurable resin (step S42). After that, in step S5, scanning by laser light is performed to perform photo-curing for one layer. Next, it is determined in step S6 whether or not all the laminations have been completed. If the determination is no, the process returns to step S2 to repeat the lowering of the table and the laser scanning. If the determination is yes in step S6, the process proceeds to step S7, in which the knife is moved to the initial position, the table is raised in step S8, and the three-dimensional structure is removed from the table in step S9. Remove and complete stereolithography.

In the above-mentioned stereolithography apparatus, during a series of stereolithography processes, only the sedimentation of fillers and beads occurs during the laser scan in step S5 in FIG. 7, so that the amount of sedimentation is very small. By the operation of the electromagnetic driving device, the sedimentation and accumulation can be suppressed.
Therefore, stirring after completion of modeling is unnecessary or minimal, and as a result, the cycle time of modeling can be shortened.

[Brief description of the drawings]

FIG. 1 is a partially cutaway perspective view showing an optical shaping apparatus according to a first embodiment of the present invention.

FIG. 2 is a cross-sectional view illustrating a main configuration of the optical shaping apparatus.

FIG. 3 is a cross-sectional view illustrating a main configuration of an optical shaping apparatus according to a second embodiment.

FIG. 4 is a cross-sectional view illustrating a main configuration of an optical shaping apparatus according to a third embodiment.

FIG. 5 is a process chart of the optical shaping using the optical shaping apparatus of the first embodiment.

FIG. 6 is a process diagram of an optical shaping using the optical shaping apparatus of the second embodiment.

FIG. 7 is a process chart of the optical shaping using the optical shaping apparatus of the third embodiment.

FIG. 8 is a diagram illustrating a main configuration of a conventional stereolithography apparatus.

FIG. 9 is a partially cutaway perspective view showing a state in which a stirrer is attached to a conventional stereolithography apparatus.

FIG. 10 is a process chart of the optical shaping by the optical shaping apparatus.

[Explanation of symbols]

 (1) Resin tank (11) Guide rail (2) Elevating table (3) Knife (4) Laser irradiation device (41) Scanner mirror (42) Laser beam (51) Support arm (5) Stirring fin (6) Elevating mechanism (7) Stirring plate (71) Belt (8) Stirring roller (81) Electromagnetic drive

Claims (7)

[Claims] An elevation table (2) is arranged in a photo-curable resin (10) in a resin tank (1), and a liquid surface of the photo-curable resin (10) is scanned with a laser beam. Thus, in the optical shaping apparatus for laminating and curing the photo-curable resin (10) on the elevating table (2) to form a three-dimensional object having a predetermined shape, a stirrer is installed at the bottom of the resin tank (1). The stirrer operates the stirrer during a period excluding a scanning step using a laser beam during a series of steps of curing one layer of the photocurable resin (10). 2. A knife (3) reciprocatingly driven along the surface of the photocurable resin (10), wherein the stirring device comprises a knife.
The stereolithography apparatus according to claim 1, further comprising a stirring fin (5) reciprocating along the bottom surface of the resin tank (1) in conjunction with the reciprocating movement of (3). 3. The stirring fin (5) is formed in an arc shape whose cross section is directed obliquely upward, and a pair of stirring fins (5) (5).
The stereolithography device according to claim 2, wherein the devices are arranged back to back. 4. The stirrer includes a belt (71) stretched along the bottom surface and both inner side surfaces of the resin tank (1), and the belt (7).
One or a plurality of stirring plates (7) protruding from the surface of (1), and the belt (71) installed outside the resin tank (1) and the resin tank (1)
The stereolithography apparatus according to claim 1, further comprising a drive mechanism that reciprocates along a bottom surface and both inner side surfaces of the laser beam. 5. The light according to claim 4, wherein a spatula (74) for scraping off the photocurable resin (10) attached to the belt (71) is provided above the resin tank (1). Modeling equipment. 6. The stirrer includes a stirring roller (8) rotatably disposed on the bottom surface of the resin tank (1), and a stirring roller (8) provided outside the resin tank (1). The optical shaping apparatus according to claim 1, further comprising: an electromagnetic drive device (81) that reciprocates along a bottom surface of the resin tank (1). 7. The stirrer further includes a second stirring roller (82) rotatably disposed on the inner surface of the resin tank (1), and a stirring roller provided outside the resin tank (1). Roller (82) in resin tank
(2) The second electromagnetic drive device that reciprocates along the inner surface of (1)
The stereolithography apparatus according to claim 6, comprising (83).