JP3441203B2 - Light curing molding machine with liquid level control device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention slices three-dimensional model data obtained from CAD, CT, etc. horizontally and irradiates a liquid photocuring liquid with light for photocuring along the sliced data. The present invention relates to a stereolithography apparatus of a stereolithography method for creating a three-dimensional model by solidifying one layer at a time and stacking it repeatedly in sequence. The present invention relates to a photo-curing modeling apparatus with a liquid surface height control device capable of modeling with a pitch.

[0002]

2. Description of the Related Art Conventionally, as a liquid level control system for a photo-curing molding apparatus, a photo-curing liquid is supplied to an overflow type storage tank by a circulation pump so that the photo-curing liquid always overflows from the upper edge of the storage tank. By the method to keep the height of the liquid level in the storage tank constant, or when measuring the liquid level of the photo-curing liquid with a laser measuring device, when the liquid level is out of the specified height, A means for adjusting the height of the liquid surface of the photo-curing liquid to a specified range by taking in and out a separately driven piston in the photo-curing liquid is adopted.

[0003]

However, such a device has the following drawbacks. That is, in the overflow method, hardened resin fragments other than the deliverables generated during the work of taking out the model float in the storage tank,
When selecting the molding conditions, for example, focus the laser light according to the dimensions such as the molding thickness before starting the molding, and undesired semi-cured resin and cured resin are generated due to the above-mentioned mistake in molding conditions selection. , These float in the photo-curing liquid, and these floating substances enter the liquid circulation system and adhere to or settle inside the circulation pump, the valve unit, and the filter unit, causing the circulation flow rate to change. It was difficult to always keep the surface height constant.

Further, in the piston system, in a structure in which the piston goes into and out of the storage tank from the lower part of the storage tank, the resin in contact with the piston is special, there is no seal material that can withstand long-term use, and the seal material is replaced. Sometimes it was necessary to drain the photocurable liquid from the storage tank. Furthermore, when the piston is submerged in the photo-curing liquid from the upper part of the storage tank, when the piston is pulled out upward, the viscosity of the photo-curing liquid adhering to the piston surface and the scraper part is high, so that it flows down with the passage of time, It has been difficult to maintain a constant liquid level by increasing the liquid level height. The present invention has been made in view of the above points, and an object thereof is to provide a photo-curing molding apparatus with a liquid surface height control device that solves these drawbacks.

[0005]

[Means for Solving the Problems] That is, means for achieving the object are a storage tank for storing a photo-curing liquid which is cured by light irradiation, a table which moves up and down in the storage tank, and the storage. A light source that irradiates an arbitrary position on the liquid surface in the tank,
The following control means, that is, (1) irradiate the liquid surface of a region corresponding to one cross section of the desired shaping with the light source, (2)
In a photo-curing modeling apparatus including a controller that repeats a control procedure of settling the table, a measuring device that measures the height of the liquid level of the photo-curing liquid, a roller pump and an auxiliary liquid provided outside the storage tank. A tank, a pipe for moving the photocurable liquid between the auxiliary liquid tank and the storage tank by the roller pump, and the height of the liquid level of the photocurable liquid in the storage tank is measured by the measuring device. However, when the height of the liquid level measured with respect to the specified liquid level is high, from the storage tank side to the auxiliary liquid tank side, conversely with respect to the specified liquid level height When the height of the measured liquid surface is low, a roller pump controller for driving the roller pump to move the photocurable liquid from the auxiliary liquid tank side to the storage tank side is added. And a photo-curing modeling device with a control device It is. Here, the measuring device can be selected from a reflection type laser measuring device, an ultrasonic measuring device and an optical reflection measuring device.

[0006]

[Function] The roller pump can move the liquid without contact with the photo-curing liquid. If the liquid level in the storage tank is too high, it is discharged to the auxiliary liquid tank, and if the liquid level in the storage tank is too low, the auxiliary liquid is discharged. Can be returned from the tank. In this way, the liquid level in the storage device is controlled to be constant. During this time, since the roller pump does not come into contact with the liquid, malfunctions such as pump clogging are prevented. The liquid level is accurately measured by a laser measuring device, an ultrasonic measuring device, an optical reflection measuring device, or the like.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described in detail below with reference to the drawings. FIG. 1 is a perspective view showing a main part of an embodiment of the photo-curing modeling apparatus of the present invention, FIG. 2 is an external view of the photo-curing modeling apparatus, FIG.
[FIG. 3] is an explanatory view of a main part of the present invention. 1 to 3, a controller 5 for performing various controls is housed inside the photo-curing modeling apparatus 1, and a storage tank 7 for accumulating a photo-curing liquid 6 is provided on a frame (not shown) in a central portion. It is arranged.

A frame (not shown) is provided around the storage tank 7, and Z rails 28 and 29 having a slidable Z cursor 27 are attached to the frame.
Further, the Z cursor 27 is engaged with the Z table supports 30 and 31, and the Z table supports 30 and 31 are engaged with the Z table 3.
2 is fixed so as to be parallel to the liquid surface of the photocuring liquid 6, and when the AC motor 39 is driven, the Z table 32 moves up and down, and the three-dimensional modeled object M is the Z table. Formed on 32. Reference numeral 43 in the figure denotes a laser oscillator, and the oscillated laser light is emitted from the optical system, 48, 47,
It is vertically incident on the liquid surface via 46 and 40. 46 in the figure
Indicates an optical fiber. Reference numeral 40 in the drawing denotes an objective lens, which can be moved to an arbitrary position on the liquid surface by an XY moving mechanism. The process for photo-curing molding is well known, and the details thereof are disclosed in many documents.

As shown in FIG. 1, particularly in FIG. 3, a roller pump 50 and an auxiliary liquid tank 51 are arranged outside the storage tank 7, and a roller pump is provided between the auxiliary liquid tank 51 and the storage tank 7. A flexible tube 52, which has a restoring force because it is pressed at least in the roller pump portion, is used as piping. Here, the principle of the roller pump 50 will be described. The roller pump is a pump that sequentially presses the soft and elastic tube 52 with a roller to suck and discharge.

FIG. 4 shows the basic operation of the roller pump. By rotating and moving the flexible tube 56 with the roller 55, the liquid or gas body in the tube 56 is squeezed out. Suction occurs at the place where the roller passes, and the next liquid is sucked. FIG. 5 shows an enlarged view of the roller pump 50, which is a continuous pump by making the tube support 60 into an arc. Rollers 58 are attached to disk 62, which rotates about axis 51. The number of rollers and the number of tubes are not limited. FIG. 6 shows that reversing the moving direction of the roller causes the suction and drawing directions to be reversed. There is also a planetary rolling mechanism system as a rotation driving method for the rollers. By using this roller pump 50, the photo-curing liquid can be transferred between the storage tank 7 and the auxiliary liquid tank 51. Since the photo-curing liquid and the roller pump are not in contact with each other, the liquid does not reduce the durability of the roller pump or clog the roller pump.

A laser measuring device 49 for directly measuring the liquid surface height is provided above the storage tank 7, and the measurement result is transmitted to the controller 5 according to a command from the controller 5. The laser measuring instrument emits a laser beam from its emission port, and the reflected light reflected by the liquid surface enters the incident port of the reflection type measuring instrument and measures the distance to the liquid surface by a triangulation method or the like. The controller 5 performs a comparison calculation between the liquid level specified range value input in advance and the transmitted measurement distance, and drives the roller pump 50 by a command according to the difference.

Next, the operation will be described. If the measured liquid level is higher than the specified range, the roller pump 5
0 from tank 7 to auxiliary liquid tank 51 flexible tube 52
The photo-curing liquid is sent through a pipe containing the. At this time, even if the curable resin and the semi-cured resin are contained in the photocurable liquid, they do not become clogged. If the measured liquid level is lower than the specified range,
The roller pump is rotated in the opposite direction to send the photocurable liquid from the auxiliary liquid tank 51 to the storage tank 7 through the pipe including the flexible tube 52. In this way, the liquid level of the photocurable liquid in the storage tank 7 is controlled so as to always be within the specified range.

In the above embodiments, the case where the roller pumps can be reversibly driven has been described, but when using one-way roller pumps, a plurality of rollers may be provided for control. The timing of performing the liquid level control can be selected according to the shape and size of the three-dimensional model as shown below. The control is repeated every time the stacking pitch of the three-dimensional model is changed. The control is repeated every certain time. And are combined, and control is performed every shorter time. The liquid level is constantly measured, and control is performed when it is out of the specified range.

If the amount of the photo-curing liquid used for creating the three-dimensional model is within the margin of the auxiliary liquid tank 51, the replenishment work of the photo-curing liquid 6 after taking out the three-dimensional model is performed by using this liquid level control system. You can also do it.

[0015]

As described above, according to the present invention, the following effects can be obtained. I. Even if the dimensions of each component change and the volume of the photo-curing liquid changes due to temperature changes, the liquid surface height can be kept within the specified range, so a three-dimensional model with a uniform stacking pitch can be created. can do. B. There is no change in liquid level due to the effects of the cured resin and semi-cured resin in the liquid tank. C. Since there are few constituent parts, the frequency of maintenance is also small,
Easy maintenance. D. Compared to the piston method, the amount of change in liquid level height over time is small.

[Brief description of drawings]

FIG. 1 is a perspective view of an internal structure showing a plotter type photo-curing molding apparatus according to an embodiment of the present invention.

FIG. 2 is an external perspective view of a photo-curing modeling device.

FIG. 3 is an explanatory view of main parts showing an embodiment of the present invention.

FIG. 4 is a diagram illustrating the principle of a roller pump.

FIG. 5 is a diagram illustrating the basic structure of a roller pump.

FIG. 6 is a diagram illustrating the basic structure of a roller pump.

[Explanation of symbols]

1 Light curing modeling equipment 5 controller 6 Light curing liquid 7 storage tanks 50 roller pump 51 Auxiliary liquid tank 52 Flexible tube

Front page continuation (72) Inventor Kimitaka Oka 4-6-32, Higashi-Kashigaya, Ebina City, Kanagawa Toyo Denki Seizo Co., Ltd. Sagami Plant (56) Reference JP-A-4-83632 (JP, A) JP-A 4-102593 (JP, A) Tokuyohei 4-503634 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) B29C 67/00

Claims (2)

(57) [Claims] 1. A storage tank for storing a photocurable liquid that is cured by light irradiation, a table that moves up and down in the storage tank, a light source that irradiates light at an arbitrary position on the liquid level in the storage tank, and the following control means: That is, (1) the light source irradiates the liquid surface in a region corresponding to one cross section of the desired shape, (2)
In a photo-curing modeling apparatus including a controller that repeats a control procedure of settling the table, a measuring device for measuring the height of the liquid surface of the photo-curing liquid, a roller pump and an auxiliary liquid provided outside the storage tank. A tank, a pipe for moving the photocurable liquid between the auxiliary liquid tank and the storage tank by the roller pump, and the height of the liquid level of the photocurable liquid in the storage tank is measured by the measuring device. However, when the height of the liquid level measured with respect to the specified liquid level is high, from the storage tank side to the auxiliary liquid tank side, conversely with respect to the specified liquid level height And a roller pump controller that drives the roller pump so as to move the photocurable liquid from the auxiliary liquid tank side to the storage tank side when the height of the measured liquid level is low. With liquid level controller Light curing modeling equipment. 2. The measuring device is a reflection type laser measuring device,
The photo-curing molding apparatus with a liquid surface height control device according to claim 1, which is selected from an ultrasonic measuring device and an optical reflection measuring device.