JPH03239531A - Manufacture of solid model - Google Patents

Abstract

PURPOSE:To avoid influences of temp. change and oxygen hindrance and to shorten remarkably manufacturing time for a model by inserting a container having an opening on its bottom in a photocurable fluid substance while inside of the container is compressed with a compressed fluid, moving the irradiated part while light irradiation is performed to form a continuously solidified part of the photocurable fluid substance. CONSTITUTION:A table 3 is sunk in a specified depth to the liq. surface of a photocurable resin 2. An irradiation device 4 is inserted in a resin liq. 2 from the upper side of the liq. surface and a compressed fluid is fed in the irradiation device 4 to push down the resin liq. 2 and the resin liq. is irradiated with a light flux. A resin liq. 2 between the irradiated part of the liq. surface and the table 3 below it is cured to form a cured product on the table. When the irradiation device 4 is moved horizontally, a cured layer 5a corresponding to the shape of the lowermost layer of a solid model is formed on the table 3. After the table 3 is lowered by a thickness of a layer of the cured layer, another cured layer 5b is formed on the cured layer.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a three-dimensional model manufacturing method for forming a solid having a desired shape using a photocurable fluid material.

[Conventional technology]

A photocurable fluid material is housed in a container, and while the substance is irradiated with concentrated light energy, the irradiated area is moved horizontally to create a thin assimilation layer of the photocurable material corresponding to a predetermined cross-sectional shape of the object to be modeled. By repeating the operation of adding a new photocurable fluid material layer to the surface of the assimilated layer, and irradiating concentrated light energy again to form an assimilated layer with a cross-sectional shape that is continuous with the solidified layer. Japanese Patent Publication No. 63-40650 proposes an optical modeling method in which a three-dimensional object of a desired shape is formed by sequentially laminating assimilated layers having a predetermined cross-sectional shape. According to the method described in the publication, it is possible to manufacture a three-dimensional model with a complicated shape using a photocurable resin liquid such as modified polyurethane methacrylate, oligoester acrylate, epoxy acrylate, or urethane acrylate. Normally, when manufacturing a three-dimensional model by this method, after forming a solidified layer with one cross-sectional shape, a predetermined thickness of uncured photo-cured material is placed on the solidified layer to form a solidified layer with the next cross-sectional shape. It is necessary to supply a fluid substance.

In the method described in the above-mentioned publication, this operation involves additionally injecting a required amount of photocurable fluid material into the container, and increasing the height of the top surface (hereinafter referred to as "liquid level") of the photocurable fluid material in the container by a predetermined amount. This is done by raising the solidified layer and immersing the solidified layer into the photocurable fluid material to a predetermined depth. In this three-dimensional model manufacturing method, the thickness of the assimilated layer formed at one time is 0.
Since it is extremely thin, about 1 mm to 1 mm, the depth to which the assimilation layer is immersed is correspondingly small.

However, the upper surface of the solidified layer of the workpiece is completely cured by light irradiation and is in a dry state, so it is not compatible with the photocurable fluid material, and as mentioned above, if the immersion depth is extremely small, the outer edge of the solidified layer A problem has arisen in that a curved free surface of the surrounding photocurable fluid material is formed due to surface tension in the solidified layer, preventing the surrounding photocurable fluid material from being introduced to the upper surface of the solidified layer.

For this reason, when actually manufacturing a three-dimensional model using the above method, a method is used in which a vertically movable base is immersed in a container and the solidified layer is laminated on this base. After forming the layer, the base is lowered by a large distance of about 10 to 50 mm, and the model being manufactured (hereinafter referred to as the "work") is submerged in light and a curable substance, and the upper surface of the solidified layer and the surrounding area of the work is light-cured. After creating a sufficiently large difference in height between the substrate and the liquid surface of the solidified material and allowing the surrounding photocurable material to flow onto the upper surface of the solidified layer, the substrate is raised again to obtain a predetermined immersion depth.

[Problem to be solved by the invention]

In the above method, it is necessary to lower the workpiece greatly and then raise it to the specified immersion depth, and it takes time to move the substrate up and down and to stabilize the liquid level after adjusting the substrate to the specified immersion depth. There is a problem in that it takes a long time to prepare for starting the next light irradiation after the formation of one solidified layer. This three-dimensional model manufacturing method uses an extremely thin solidified layer (0.1 to 1 m thick).
m) to complete the three-dimensional model by laminating the three-dimensional model, the above operation may be performed more than 1000 times when manufacturing one model, and the preparation period described above has a large effect on the model manufacturing time. In particular, when the cross-sectional area of the workpiece is large, the vertical movement of the base for introducing the fluid material must be set accordingly, and the time required for the fluid material to cover the top surface of the solidified layer of the workpiece will also be longer. It took quite a long time to operate.

In addition, in the above method, the surface of the photocurable fluid material is exposed to the atmosphere, so the temperature of the surface of the fluid material changes due to changes in air temperature, causing a problem in which the curing speed due to light irradiation fluctuates. .

Furthermore, in the above method, since the surface is in contact with the atmosphere, there is a problem that oxygen in the atmosphere is adsorbed onto the surface of the fluid material.

Acrylic photocurable resins such as urethane acrylate and epoxy acrylate have a property (oxygen inhibition) that in the presence of oxygen, an inhibition reaction occurs and the photocuring reaction is difficult to occur (oxygen inhibition). When a resin is used, a problem arises in that the curing speed is slow and the time required to form a solidified layer becomes long.

In order to solve the above-mentioned problems, the present invention shortens the preparation period until starting the solidified layer formation by the method after forming one solidified layer,
It is an object of the present invention to provide a three-dimensional model manufacturing method that can significantly shorten model manufacturing time by eliminating the effects of temperature changes and oxygen inhibition.

[Means to solve the problem]

The three-dimensional model manufacturing method of the present invention is characterized in that the solidified layer is formed by light irradiation under the steady liquid level of the photocurable material.

That is, according to the present invention, a light curing light source is provided in a container having an opening at the bottom, and a photocurable fluid material is inserted into the container while pressurizing the inside of the container with a pressure fluid, and the fluid material is heated by the pressure inside the container. In addition to preventing intrusion into the container, forming an interface between the pressurized fluid and the fluid substance at the lower part of the opening, and irradiating the interface with light from a front light distribution source while moving the irradiation point together with the opening. A three-dimensional model manufacturing method is provided, which is characterized by forming a continuous solidified portion of a photocurable fluid material.

Further, according to the present invention, a pressure fluid is continuously injected from a nozzle toward the liquid surface of the photocurable fluid material, and a recess of a predetermined depth is created in the liquid surface,
While irradiating the liquid surface in the recess with light from a photocuring light source, the nozzle and the light source are moved to form a continuous flat solidified material below the steady liquid surface of the photocurable fluid material. A three-dimensional model manufacturing method is provided.

[For production]

According to the first method of the present invention, the liquid surface of the fluid material formed at the lower part of the opening of the container inserted into the photocurable fluid material is solidified by light irradiation, and the container is moved to move the irradiated area. As a result, a solid having a desired shape is formed in the liquid. Since the solidified part is always below the liquid level, by moving the container, the assimilated part is immediately covered with the fluid material. Furthermore, since the light irradiation is performed at a steady liquid level, the irradiated area is not affected by changes in temperature. Furthermore, if the inside of the container is pressurized with a fluid that does not contain oxygen, oxygen will not be adsorbed on the liquid level at the bottom of the opening of the container.

According to the second method of the present invention, the nozzle and the photocuring light source are simultaneously moved horizontally while irradiating light onto the recesses in the liquid surface of the photocuring material generated by the jet from the nozzle. A solidified layer is formed. Since the recess moves together with the nozzle, the formed solidified portion is immediately submerged in the liquid.

The irradiated area is always at a steady liquid level and is not affected by changes in temperature, and if a fluid containing no oxygen is injected from the nozzle, oxygen adsorption to the liquid level in the recess can be prevented.

〔Example〕

An embodiment of the three-dimensional model manufacturing method according to the present invention is shown in FIG.

In FIG. 1, 1 is a container containing a photocurable resin 2;
3 is a table that is movable up and down, and 4 is a light irradiator in which a light source for photocuring is installed. The vertical movement of the table 3 and the horizontal and vertical movement of the irradiator 4 are each performed by a drive device (not shown), and the position and speed of each are controlled by a known method for NC machine tools and the like.

The irradiator 4 is connected to a substantially cylindrical hollow container 11 having an opening 12 at one end as shown in FIG. ) is supplied with pressurizing fluid.

Furthermore, high-energy light from an externally provided laser oscillator (not shown) is supplied to the inside of the container 11 via a light guiding means 14 such as an optical fiber. Reference numeral 15 denotes a condenser that condenses the light beam from the light guiding means 14 to a predetermined location near the aperture 12.

In this example, when starting the production of a three-dimensional model, the table 3 was first placed on the photocuring resin 2 as shown in FIG. 1(A).
sink to a predetermined depth relative to the liquid level. The depth to which the table 3 is sunk is set to be greater than the thickness of the solidified layer formed by the operation described below. Next, the irradiator 4 is inserted into the resin liquid 2 from above the liquid level and is opposed to the table 3 at a predetermined distance. At this time, pressurized fluid is supplied to the container 11 of the irradiator 4 from the connection port 13, and the container 1
1. The internal pressure is increased to prevent the resin liquid 2 from entering the container. The pressurized fluid is an inert gas such as nitrogen gas or argon gas, a gas such as air, or a liquid such as liquid paraffin or water, and when the resin liquid 2 is photocured, the pressurized fluid is applied to the resin solidification surface. Avoid adhesion. By pressurizing the inside of the container, the resin liquid 2 is pushed down by the pressurized fluid to just below the opening 12, as shown in FIG. 2, and a liquid level 2a is formed at the boundary between the resin liquid 2 and the pressurized fluid. The distance between the liquid level 2a and the opening 12 is adjusted by changing the fluid pressure supplied into the container 11. For this liquid level position adjustment,
A non-contact sensor (not shown) that uses light reflection on the liquid surface or other known liquid level sensor is provided in the container 11 to detect the liquid level position, and adjust the pressurized fluid pressure to adjust the liquid level. The opening 1
It is also possible to maintain it at a constant distance from 2.

After inserting the irradiator 4 into the resin liquid 2, the liquid level 2 can be adjusted by adjusting the vertical position of the irradiator 4 and/or the pressurized fluid pressure.
The distance between a and the table 3 is maintained equal to the thickness of the assimilation layer to be formed. In this state, a light beam is irradiated from the light guiding means 14 and converged by the condenser 15 to one point on the liquid surface 2a. As a result, the resin liquid 2 between the irradiated part on the liquid surface 2a and the table 3 below it is hardened, and a solidified substance is formed on the table. When the irradiator 4 is moved horizontally from this state in a controlled manner along a predetermined trajectory, an assimilation layer 5a corresponding to the cross-sectional shape of the lowermost layer of the three-dimensional model is formed on the table 3 (FIG. 1(A)). ). Next, the light irradiation is stopped and the table 3 is lowered by a distance corresponding to the thickness of the solidified layer (FIG. 1(B)). When the irradiator 4 is moved horizontally while performing subsequent light irradiation, another solidified layer 5b is formed on the solidified layer (FIGS. 1(C) and 2). By repeating this operation, assimilation layers with a predetermined cross-sectional shape can be laminated on the table 3 (FIG. 1(b)), and a three-dimensional model with a desired shape can be obtained.

According to this embodiment, the resin is cured in the liquid, and the solidified portion is immediately covered with the resin liquid when the irradiator 4 is moved, so there is no need to introduce a predetermined thickness of the resin liquid onto the solidified layer. It is. Therefore, the time required from the completion of one solidified layer formation to the start of the next solidified layer formation is based on Table 3 by a predetermined amount (0, 1
〜l mff1) Only the time needed to lower it is reduced, and the required time is significantly shortened. Further, since the resin liquid is cured in the liquid, changes in temperature do not reach the irradiated area, so the curing speed does not fluctuate. A further advantage of this method is that if a pressurized fluid that does not contain oxygen is used as the pressurized fluid supplied to the container 11, the curing speed can be increased compared to conventional methods even when using a resin that is inhibited by oxygen, such as an acrylic photocurable resin. This can be significantly increased. By preventing oxygen inhibition, the photocuring speed can be increased usually by 2 to 4 times, up to about 30 times, and the model production time is significantly shortened. Further, according to the present method, by controlling the heating temperature of the pressurized fluid, the light irradiated portion of the resin liquid can be heated and the curing speed can be increased, so that the curing operation can be performed under optimal conditions.

FIG. 3 shows another embodiment of the method of the invention. In this embodiment, the optical system 14, 15 in FIG. 2 is positioned above the surface of the resin liquid 2, and the nozzle 21 is used to continuously inject pressurized fluid onto the liquid surface. As a result, the surface of the resin liquid is pushed by the jet and forms a recess 22 .

Similar to the method shown in FIG. 2, the depth of the recess 22 is kept constant by adjusting the jet pressure using a liquid level sensor. In this embodiment, light irradiation is performed on the bottom liquid surface 22H of the recess 22. Similar to the method of FIG. 1, the nozzle 22
By horizontally moving the light guiding means 14 and the condenser 15, the concave portion 22 also moves, and the irradiated area on the liquid surface 22a also moves horizontally, so that a flat plate is formed below the steady surface of the resin liquid 2. A solidified layer 5 is formed. It can be seen that a similar three-dimensional model can be formed by repeating the lowering of the table 3 and the irradiation of light in the same manner as in the method shown in FIG. In this method as well, since the assimilated portion is submerged in the liquid as the recess 22 moves, there is no need to introduce the resin liquid onto the assimilated layer. Further, as in the method shown in FIG. 1, optimum curing conditions can be set by making the pressurized fluid jetted from the nozzle 9 free of oxygen or by controlling the temperature of the pressurized fluid.

The present invention is not limited to the above embodiments, and various modifications are possible. For example, in the embodiment shown in FIG. 2, the light guide 14 is used to irradiate the west and east directions, but it is also possible to guide the light to the irradiation location using a reflecting mirror without using the light guide. In this case, a similar configuration can also be obtained by providing the condenser 15 passing through the end surface of the container 11 facing the opening 12 and keeping the space between the condenser 15 and the wall of the container 11 airtight. In addition, in FIG. 3, the light guide 14 and the condenser 15
Instead of being provided outside the nozzle 21, it is also possible to provide it inside the nozzle 21, resulting in a structure similar to that shown in FIG.

〔Effect of the invention〕

In the present invention, the following effects can be obtained by forming an assimilation layer by light irradiation below the steady liquid level of the resin liquid as described above. First, since the surface of the solidified layer is always submerged in the liquid, there is no need to introduce the resin liquid into the upper part of the solidified layer, and the time that was conventionally required for large vertical movements of the table is no longer necessary. Furthermore, since there is no need to wait for the level of the resin liquid to settle, the time required from the completion of forming one solidified layer to the start of formation of the next solidified layer can be significantly shortened.

Second, the resin liquid layer that performs light irradiation is below the steady liquid level;
Since it is less affected by temperature changes, the curing speed of the resin can be kept constant.

Thirdly, by irradiating the resin liquid below the steady liquid level, the light irradiated area can be shielded from the atmosphere, so a high curing rate can be obtained even in the case of a resin that is inhibited by oxygen.

Furthermore, fourthly, since the irradiation position is not affected even if the steady level height of the resin liquid changes, the liquid level control of the resin liquid, which was conventionally required, becomes unnecessary.

Due to the above effects, according to the present invention, it is possible to significantly shorten the time required for manufacturing a three-dimensional model.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram showing an embodiment of the three-dimensional model manufacturing method according to the present invention, FIG. 2 is a sectional view showing the bottom of the gutter of the light irradiator of the same embodiment, and FIG. It is a figure which shows another Example of a manufacturing method. 1... Container, 2... Photocurable resin,
3...Table, 4...Light irradiator, 5...
...Solidified layer, 11...Container, 12...Opening, 13...Connection port, 14...Light guide means, 15...Concentrator, 21...Nozzle, 2
2... Concavity.

Claims (1)

[Claims] 1. A light source for photocuring is provided in a container having an opening at the bottom,
The inside of the container is pressurized with a pressure fluid and inserted into the photocurable fluid material, and the pressure inside the container prevents the fluid material from entering the container, and a boundary between the pressure fluid and the fluid material is formed at the lower part of the opening. A method for producing a three-dimensional model, comprising forming a surface, irradiating the boundary surface with light from the light source, and moving the irradiated area together with the opening to form a continuous solidified portion of a photocurable fluid material. 2. Continuously inject pressure fluid from a nozzle toward the liquid surface of the photocurable fluid material to create a recess of a predetermined depth in the liquid surface, and apply light from a photocuring light source to the liquid surface within the recess. A method for manufacturing a three-dimensional model, comprising moving the nozzle and the light source while performing irradiation to form a continuous flat solidified material below a steady liquid surface of a photocurable fluid material.