JPH11314275A - Photosetting shaping device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a photosetting shaping device in which recoating onto the top surface of a cured layer by photosetting liquid is always performed stably in estimated thickness without causing mixing of air and destruction of the cured layer. SOLUTION: In the photosetting shaping device, a cured layer cured by irradiation of light for photosetting liquid 22 is settled into liquid and also the top surface of the settled cured layer is covered with uncured liquid by a recoater 30 moved along the liquid level of photosetting liquid 22. The recoater 30 is equipped with an applicator roll 40 capable of drawing photosetting liquid 22 by rotating the applicator roll 40 in a state touching the liquid level of photosetting liquid 22, a pickup roll (e.g. a second roll 42) on which photosetting liquid drawn by the applicator roll 40 is transferred, and a metering roll (e.g. a third roll 44) rotated in the position having a prescribed clearance 46 between the metering roll and the outer peripheral face of the applicator roll 40. Photosetting liquid caught by the metering roll is pushed out on the top surface of the cured layer through the clearance 46.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a photo-curing molding apparatus, and more particularly to a photo-curing molding apparatus in which an upper surface of a cured layer is moved along an uncured photo-curable liquid so as to cover the upper surface of the cured layer. Related to the device.

[0002]

2. Description of the Related Art A photo-curing molding technique has been developed to actually form a non-existent three-dimensional shape such as a three-dimensional shape designed by a CAD system.
In this technique, a liquid that hardens when irradiated with light is used and is stored in a liquid tank. Then, as a first step, light is applied to a specific area of the liquid surface of the photocurable liquid to form a cured layer corresponding to a certain cross section. Next, as a second step, the cured layer is settled in the liquid, and as a third step, an uncured photocurable liquid is introduced onto the upper surface of the settled cured layer. This first one
The third step is defined as one cycle, and by repeating this cycle, a three-dimensional object is formed in which the cured layers are laminated and integrated. In the first step, a three-dimensional object having an arbitrary three-dimensional shape is formed by controlling the irradiation area for each cross section. This technology is disclosed in, for example,
No. 144478 and U.S. Pat. No. 2,775,758.

In the photocuring molding technology, when the amount of settling of the cured layer is large or the viscosity of the photocurable liquid is low, the uncured liquid is deposited on the upper surface only by sedimentation of the cured layer. It flows naturally from the surroundings. Therefore, no special device is required for the third step. However, recently, in order to increase the accuracy of a formed article by reducing the thickness of the cured layer per operation, the amount of sedimentation of the cured layer per operation tends to be smaller. Then, due to the interfacial tension of the photo-curable liquid, the uncured liquid does not flow into the upper surface of the cured layer only by sinking the cured layer, or it takes a long time to flow. This phenomenon is more remarkable when a high-viscosity photocurable liquid is used to increase the strength of the modeled object.

Therefore, various proposals have been made to realize or accelerate the third step. As an example, a recoater technique shown in FIG. 6 can be cited, for example. In this technique, after the cured layer 23 cured by light irradiation is settled in the liquid, a recoater 70 called a doctor blade is moved along the liquid surface of the photocurable liquid 22 to thereby form the cured layer 23. The upper surface is coated (recoated) with an uncured liquid.

[0005]

According to the technique shown in FIG.
The thickness of the recoat layer is determined by the clearance between the recoater 70 and the cured layer 23 and the moving speed of the recoater 70. When the viscosity of the photocurable liquid 22 is low, the moving speed of the recoater 70 needs to be increased accordingly.
However, when the photocurable liquid 22 has a low viscosity, it is difficult to control the uncured liquid once applied on the cured layer 23 to a specified thickness only by increasing the moving speed of the recoater 70. In an extreme case, the viscous resistance of the photo-curable liquid 22 against the movement of the recoater 70 may cause the cured layer 23 to vibrate.
The shaking has an adverse effect on the accuracy of the printed object.

[0006] The doctor blade type recoater 70 comprises:
Due to its structure, air is easily entrained in the photocurable liquid 22 during recoating. Also, even if slight peeling of the cured layer 23 occurs during recoating,
May be caught and the molded object may be damaged. Further, when the viscosity of the photocurable liquid 22 is high, the recoating time is prolonged due to the interfacial tension, which affects the modeling time itself.

An object of the invention described in claim 1 is to recoat a hardened layer with a photo-curable liquid on a top surface of a hardened layer at a predetermined thickness without causing air mixing or destruction of the hardened layer. It is to be able to do it.

An object of the invention described in claim 2 or 3 is, in addition to the above-mentioned object, to be able to cope with a photocurable liquid in a wide range from low viscosity to high viscosity and to realize more appropriate recoating.

Another object of the present invention is to make it possible to achieve a state in which recoating can be started in a short time.

An object of the invention described in claim 5 is to enable setting of various recoat modes.

An object of the invention according to claim 6 or 7 is to further stabilize the supply of the uncured liquid to the upper surface of the cured layer.

[0012]

According to the first aspect of the present invention,
For the liquid surface of the photocurable liquid, light irradiation means for irradiating light in a light irradiation area determined based on the modeling data, and sedimentation means for setting a cured layer cured by light irradiation in the liquid,
And a recoater for coating the upper surface of the cured layer settled by moving along the liquid surface of the photocurable liquid with an uncured liquid, wherein the recoater is a photocurable liquid. An applicator roll capable of pumping the photocurable liquid by rotating while being in contact with the liquid surface; a pickup roll to which the photocurable liquid pumped by the applicator roll is transferred; A metalling roll that rotates at a position that receives the photocurable liquid sent by rotation and has a predetermined clearance between the applicator roll and the outer peripheral surface thereof, and is received by the metalling roll. The photocurable liquid is extruded onto the upper surface of the cured layer through the clearance.

[0013] The photocurable liquid thus pumped by the applicator roll and sent to the metalling roll via the pickup roll is pushed out of the clearance between the applicator roll and the metalling roll. By moving the recoater along the liquid surface of the photocurable liquid in parallel with the above, the uncured liquid can be stably supplied to the upper surface of the cured layer. Therefore, regardless of the difference in the viscosity of the photocurable liquid, the upper surface of the cured layer can be uniformly coated (recoated) with the uncured liquid at a predetermined thickness.

Further, the air entrained in the photocurable liquid at the time of recoating is pushed out to the atmosphere by a compressive force when the liquid passes through the clearance between the applicator roll and the metering roll. For this reason, the incorporation of air into the recoat layer is prevented or reduced, so that the quality of the molded article is improved and the strength is increased. Furthermore, since the recoater is of a roll type, a situation in which the molded article is damaged by a slight peeling or the like generated in the cured layer is avoided.

According to a second aspect of the present invention, there is provided the photocuring molding apparatus according to the first aspect, wherein a clearance between the applicator roll and the metering roll is adjustable.

According to a third aspect of the present invention, there is provided the photocurable molding apparatus according to the first aspect, wherein a difference in rotation speed between the applicator roll and the metering roll is adjustable.

According to these constructions, one or both of the clearance and the rotation speed difference between the applicator roll and the metering roll are appropriately set in accordance with the viscosity of the photo-curable liquid, so that a low viscosity is obtained. It can be used for a wide range of photocurable liquids from high to high viscosity, and more stable recoating is possible. As a result, a trapping phenomenon (a swelling phenomenon) of the liquid surface due to a low viscosity at the time of recoating or an increase in a molding time due to a high viscosity is eliminated.

According to a fourth aspect of the present invention, there is provided the photocurable molding apparatus according to the first aspect, wherein the liquid level of the photocurable liquid in contact with the applicator roll can be temporarily raised. It has.

In this case, when the liquid level of the photocurable liquid is raised at the start of recoating and each roll is rotated without moving the recoater, the photocurable liquid flows from the clearance to the upper surface of the cured layer. A state in which recoating can be started, that is, a state in which recoating can be started is achieved in a short time.

According to a fifth aspect of the present invention, there is provided the photocurable molding apparatus according to the first aspect, wherein the recoater can be selected from a forward rotation roll type and a reverse roll type. By making the recoater method selectable in this way, various recoat mode settings can be made.

According to a sixth aspect of the present invention, there is provided the photocurable molding apparatus according to the first aspect, wherein the light is sent from a pickup roll to an upper portion of the applicator roll and between the pickup roll and the metering roll. A liquid pool of the coming photocurable liquid is formed.

In this configuration, since the photo-curable liquid pumped up by the rotation of the applicator roll is temporarily stored in the liquid pool, the photo-curable liquid in this liquid pool is more stable on the upper surface of the hardened layer through the clearance. Supplied.

According to a seventh aspect of the present invention, there is provided the photocurable molding apparatus according to the sixth aspect, wherein a valve capable of preventing the photocurable liquid in the liquid pool from flowing over the outer periphery of the metering roll is provided. Have been. By controlling the opening and closing of this valve, the curling of the photocurable liquid is prevented, and an appropriate amount of liquid can be supplied.

[0024]

Embodiments of the present invention will be described below. FIG. 1 is a configuration diagram showing an overall outline of a photocuring modeling apparatus. The liquid tank 20 shown in this drawing is filled with a photocurable liquid 22 having a property of being cured when irradiated with light. The photocurable liquid 22 in the auxiliary liquid tank 28 is fed into the liquid tank 20 by the pump 26, and the photocurable liquid 22 is sent out from the liquid tank 20 to the auxiliary liquid tank 28. It is possible. Further, a measurement result from a measuring device (not shown) for measuring the liquid level inside the liquid tank 20 is transmitted to the controller 10, and the controller 10 compares the measured value with a predetermined liquid level specified in advance, The drive of the pump 26 is controlled by a command corresponding to the difference. Thereby, the photo-curable liquid 22 in the liquid tank 20 is
Can be kept constant or arbitrarily changed.

In the liquid tank 20, the photo-curable liquid 2
The elevating table 21 arranged in parallel with the liquid level 2 can be controlled to elevate by the elevating device 14. Liquid tank 2
The laser oscillator 12 arranged near 0 can emit laser light having a wavelength for curing the photo-curable liquid 22, and the emitted laser light enters the galvanometer mirror 13 provided above the liquid tank 20. Is done. The galvanomirror 13 can direct the laser beam to an arbitrary position on the liquid surface of the photo-curable liquid 22 by adjusting the mirror angle. Therefore, by continuously changing the mirror angle based on the modeling data, A specific region of the surface can be irradiated with laser light.

The recoater 30 can be moved by the traveling device 15 along the liquid surface of the photo-curable liquid 22. The laser beam emission control by the laser oscillator 12, the angle control of the galvanomirror 13, and the drive control of the lifting device 14 and the traveling device 15 are performed by signals from the controller 10 based on modeling data. Means for keeping the liquid level of the photocurable liquid 22 constant, or means for irradiating a specific area of the liquid surface with laser light,
The present invention is not limited to the above-described configuration, and any appropriate rational means may be employed.

Now, in order to form an arbitrary three-dimensional shape by the photo-curing apparatus shown in FIG.
A specific area of the liquid level 2 is irradiated with a laser beam, and a hardened layer 23 corresponding to a certain cross section is formed on the lift 21. Next, the lift 21 is lowered by a predetermined amount to set the hardened layer 23 in the photo-curable liquid 22.
Is moved along the liquid surface, so that the uncured photocurable liquid 22 is introduced and coated (recoated) on the upper surface of the cured cured layer 23. The above is one cycle, and by repeating this cycle, the hardened layer 2
The three-dimensional object is formed by laminating the three layers. At the time of recoating, when the pump 26 is driven and controlled depending on the type of the photo-curable liquid 22 and the liquid level inside the liquid tank 20 is raised above the upper surface of the hardened layer 23, the upper surface of the hardened layer 23 is matched. In some cases, or lower than the upper surface of the hardened layer 23.

The laser oscillator 12 and the galvanomirror 13 controlled by the controller 10 constitute a "light irradiation means".
The sedimentation means for sedimenting the hardened layer 23 in the liquid is mainly composed of the elevating device 14 controlled by the elevating device 14 and the elevating table 21 operated by the elevating device.

Next, the recoater 30 will be described. FIG. 2 is a front view showing a part of the recoater 30, and FIG. 3 is a sectional view taken along line III-III of FIG. As shown in these drawings, the recoater 30 has an applicator roll 40 long enough to cover the recoat width, and second and third rolls 42 and 44 located on both sides of the upper part of the applicator roll 40. It has. Both ends of the applicator roll 40 are rotatably supported with respect to the vertical frame 32,
Both ends of the second roll 42 and the third roll 44 are rotatably supported on the horizontal frame 34, respectively. However, regarding the support structure of each roll 40, 42, 44,
In FIG. 2, only one side (right side) is shown.

Each of the rolls 40, 42, and 44 is individually driven to rotate in either the forward or reverse direction by an individual drive source (not shown) such as a motor. The vertical frame 32 is controlled to move together with the horizontal frame 34 by the traveling device 15 shown in FIG. 1, and the horizontal frame 34 is moved relative to the vertical frame 32 by the operation of the vertical adjustment mechanism 36 shown in FIG. 2. The vertical position can be adjusted. By this adjustment, the second roll 42 and the third roll 4 with respect to the applicator roll 40
4 position adjustment is possible.

On the upper surface of the horizontal frame 34, a solenoid 50 used as a valve switching actuator at two locations on both sides in the length direction (recoat width direction).
Is assembled. However, only one side (right side) solenoid 50 is shown in FIG. A horizontal frame 34 is provided at the center of the movable member 52 which moves in the left-right direction in FIG.
A shaft 54 extending downward through a hole 35 penetrating vertically above and below is connected.

An arm 56 is fixed to the end of the shaft 54 below the horizontal frame 34.
A pair of left and right valves 60 and 62 are attached to the. These valves 60 and 62 are individually connected to the second
The outer circumferences of the roll 42 and the third roll 44 are selectively brought into contact by the on / off control of the solenoid 50. For example, as shown in FIG. 3, when one valve 60 is separated from the outer periphery of the second roll 42,
The other valve 62 is in contact with the outer periphery of the third roll 44.

FIGS. 4 and 5 are explanatory views showing the outline when the recoater 30 is used in a reverse roll system. First, when recoating is performed by moving the recoater 30 to the left in the drawing as shown in FIG. 4, each of the rolls 40, 42,
Each of the rollers 44 is rotated clockwise, the valve 60 for the second roll 42 is separated (opened) from the outer periphery, and the valve 62 for the third roll 44 is contacted (closed) with the outer periphery. The height of the recoater 30 is set such that the outer circumference of the applicator roll 40 is in contact with the liquid surface or at a predetermined clearance depending on the type of the photocurable liquid 22 or the like.

The rotation of the applicator roll 40 causes the photo-curable liquid 22 to be swirled by its viscosity to be pumped up and transferred to the second roll 42. Then, the liquid transferred to the second roll 42 is sent to the third roll 44 and temporarily stored in a liquid pool 64 formed above the applicator roll 40 and between the second roll 42 and the third roll 44. It is stored in. In this case, the second roll 42 functions as a pickup roll, and the third roll 4
4 functions as a metering roll. The liquid pool 6
The liquid stored in the fourth roll is a metering roll (third roll 4).
The flow over the outer periphery of 4) is prevented by the valve 62, whereby a sufficient amount of liquid is secured in the liquid pool 64.

At the start of recoating (formation start), each of the rolls 40, 42, 44 is moved without moving the recoater 30.
It is preferable that a predetermined amount of liquid is stored in the liquid pool 64 in advance by rotating the liquid. In this case, if the rolls 40, 42, and 44 are rotated at a higher speed than at the time of recoating, or if the liquid level of the photocurable liquid 22 is temporarily raised, the liquid can be stored in the liquid pool 64 in a short time. .
As means for temporarily raising the liquid level of the photo-curable liquid 22, the pump 26 may be used to
In addition to sending the light curable liquid 22, a simple method such as submerging a block having a predetermined volume in the liquid tank 20 may be used.

At the time of recoating, each roll 40, 42, 44
Is rotated at a speed set based on the thickness of the recoat layer and other various conditions, and the recoater 30 is moved along the liquid surface. As a result, the liquid in the liquid pool 64 is applied to the applicator roll 40 and the metering roll (the third roll 4).
4) and is stably supplied to the upper surface of the hardened layer 23 as described above. Therefore, according to the recoater 30, the cured layer 23
The uncured liquid can be efficiently recoated on the upper surface with a desired thickness.

In the reverse roll system, the recoater 30
When recoating is performed by moving the roller in the right direction of the drawing as shown in FIG. 5, the rolls 40, 42, and 44 are respectively rotated in the counterclockwise direction, and the valve 60 for the second roll 42 And the valve 62 with respect to the third roll 44 is separated (opened) from the outer periphery. Thereby, the same recoating as in the case of FIG. 4 is possible. However, in this case, the third roll 44
Functions as a pickup roll, and the second roll 42 functions as a metering roll.

As described above, since the recoater 30 is of a roll type, it is possible to avoid a situation in which a slight peeling or the like generated on the hardened layer 23 is caught and causes breakage. Further, the air entrained in the photo-curable liquid 22 is pushed out to the atmosphere by the compressive force when the photo-curable liquid 22 passes through the clearance 46 between the applicator roll 40 and the metering roll, and the air to the recoat layer Almost no air mixing. Note that the clearance 46 can be changed by adjusting the positions of the second roll 42 and the third roll 44 by the vertical adjustment mechanism 36.

The conditions for determining the thickness of the recoat layer include the following. A. The gap between the applicator roll 40 and the cured layer 23. B. Clearance 46 between applicator roll 40 and metering roll. C. The rotational speed difference between the applicator roll 40 and the metering roll (the greater the speed difference, the thinner the recoat layer). D. The moving speed of the recoater 30 (the faster the moving speed, the thinner the recoat layer).

The above condition A is determined by the position setting of the height of the recoater 30, and it is difficult to adjust the condition A according to the viscosity of the photocurable liquid 22. On the other hand, condition B ~
D can be adjusted, and in particular, the conditions B and D can be adjusted to have appropriate values according to the viscosity of the photocurable liquid 22. Therefore, by adjusting one or both of the clearance 46 and the rotational speed difference according to the viscosity of the photocurable liquid 22, the liquid is excessively supplied due to the low viscosity and the trap phenomenon (bump phenomenon) occurs.
, Or that it takes time to supply the liquid due to interfacial tension due to high viscosity. Therefore, it can be applied to a wide range of photocurable liquids 22 from low viscosity to high viscosity, and recoating of a predetermined thickness becomes possible.

By providing a dust removing member 66 on the outer periphery of the pickup roll (second roll 42) as shown in FIG. 4, dust mixed in the photo-curable liquid 22 pumped from the liquid tank 20 can be removed. It is possible. As the dust removing member 66, a wire net or a wire is effective other than the filter and the brush. In the case of FIG. 5, the pickup roll at that time (third roll 4
A dust removing member 66 is provided on the outer periphery of 4).

The recoater 30 can also be used in a normal rotation roll system. In this method, for example, when recoating is performed by moving the recoater 30 to the left in the drawing as shown in FIG. 4, each of the rolls 40, 42, and 44 is rotated in a counterclockwise direction. In the forward rotation roll system, although there is a possibility that the application range for the viscosity of the photocurable liquid 22 is somewhat narrower than in the reverse roll system, almost the same function as in the reverse roll system is obtained.

Therefore, various recoat modes can be set by both methods. First, as shown in FIGS. 4 and 5, there is a mode in which the recoater 30 reciprocates by a reverse roll method, and a mode in which the recoater 30 reciprocates by a forward rotation roll method. A mode in which one of the forward and backward movements of the recoater 30 is a reverse roll system or a forward rotation roll system and the other is a reverse system is also possible. In this case, the recoater 30 is reciprocated without switching the rotation direction of each roll 40, 42, 44, which is convenient.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing an overall outline of a photocuring modeling apparatus.

FIG. 2 is a front view showing a part of the recoater.

FIG. 3 is a sectional view taken along line III-III of FIG. 2;

FIG. 4 is an explanatory diagram of a case where the recoater is moved forward by a reverse roll method.

FIG. 5 is an explanatory diagram of a case where the recoater is moved backward by a reverse roll method.

FIG. 6 is an explanatory diagram showing an outline of a conventional recoater.

[Explanation of symbols]

22 Photocurable Liquid 23 Cured Layer 30 Recoater 40 Applicator Roll 42 Second Roll (Pickup Roll or Metalling Roll) 44 Third Roll (Metaling Roll or Pickup Roll) 46 Clearance 60,62 Valve 64 Liquid Pool

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Yoshikazu Oba 5-15-8 Kamata, Ota-ku, Tokyo NTT Data Seamet Co., Ltd. (72) Katsuyuki Watanabe Toyosu, Koto-ku, Tokyo 3-3-3 NTT Data Communication Co., Ltd.

Claims (7)

[Claims] 1. A light irradiation means for irradiating a liquid surface of a photocurable liquid with light in a light irradiation area determined based on modeling data, and a sedimentation for setting a cured layer cured by light irradiation in the liquid. Means and a recoater for coating the upper surface of the cured layer settled by moving along the liquid surface of the photocurable liquid with an uncured liquid, wherein the recoater is a photocurable An applicator roll capable of pumping the photocurable liquid by rotating in contact with the liquid surface of the liquid, a pickup roll to which the photocurable liquid pumped by the applicator roll is transferred, A metal ring that rotates at a position for receiving the photo-curable liquid sent by the rotation of the pickup roll, and at a position having a predetermined clearance with the outer peripheral surface of the applicator roll; A photocurable molding apparatus, comprising: a photocurable liquid received by the metalling roll, and extruded onto the upper surface of the cured layer through the clearance. 2. The photocuring molding apparatus according to claim 1, wherein a clearance between the applicator roll and the metering roll is adjustable. 3. The photo-curing molding apparatus according to claim 1, wherein a rotation speed difference between the applicator roll and the metering roll is adjustable. 4. The photo-curing modeling apparatus according to claim 1, further comprising means capable of temporarily raising the liquid level of the photo-curable liquid in contact with the applicator roll. Characteristic light-curing modeling equipment. 5. The photocuring molding apparatus according to claim 1, wherein said recoater can be selected from a forward rotation roll type and a reverse roll type. 6. The photocurable molding apparatus according to claim 1, wherein the photocurable liquid sent from the pickup roll is provided above the applicator roll and between the pickup roll and the metering roll. A photo-curing molding apparatus, wherein a liquid pool is formed. 7. The photo-curing molding apparatus according to claim 6, further comprising a valve capable of preventing the photo-curable liquid in the liquid pool from flowing over the outer periphery of the metering roll. Light-curing modeling equipment.