JP2022138437A - 3D printer - Google Patents

Abstract

To provide a 3D printer that can create a three-dimensional object with good accuracy by accurately controlling an amount of discharged resin material.SOLUTION: A 3D printer 1 includes: a resin discharge section 10 for discharging a resin material 2 melted by heating; a resin supply section 30 that supplies the resin material 2 toward the resin discharge section 10 at a predetermined supply speed; a measurement section 40 for measuring a discharge width of the resin material 2 discharged from the resin discharge part 10 as a measurement discharge width W2; and a control section 50 for controlling the resin supply speed of the resin supply section 30. The resin supply section 30 supplies the resin by rotating a motor 31. The measurement section 40 obtains a measured discharge width W1 by processing an image captured by a camera 41. The control section 50 controls the supply speed of the resin material 2 by controlling a revolution speed of the motor 31 so as to decrease a difference between the calculated discharge width W2, which is calculated based on a discharge volume of the resin material 2 to be discharged, and the measured discharge width W1.SELECTED DRAWING: Figure 1

Description

The present invention relates to 3D printers. More particularly, the present invention relates to a 3D printer that forms a three-dimensional object by heating and melting resin materials and laminating them.

Conventionally, 3D printing is known in which a three-dimensional modeled object is formed using a 3D printer that heats and melts resin materials and laminates them (also referred to as a fused lamination method or an FDM method) (for example, Patent Document 1). The 3D printer used in the invention of Patent Document 1 described above moves the print head in a three-dimensional direction and ejects a heated and melted filament (equivalent to a resin material) from the print head to create a three-dimensional object. is supposed to form In addition, in a fused lamination type 3D printer, including the 3D printer described in Patent Document 1, a filament is sandwiched between a pair of transport rollers, and by rotating the transport rollers, the filament is transferred to the print head (resin discharge unit). equivalent). Here, in the 3D printer, the amount of filament to be supplied is set according to the positional coordinates of the print head and the moving speed of the print head when forming the modeled object, and the filament is supplied to the print head according to the set amount of filament. supplied.

As described above, in a 3D printer, it is necessary to set the amount of filament supplied according to the positional coordinates of the print head and the moving speed of the print head. Therefore, unless the amount of filament supplied is accurate, a three-dimensional object cannot be modeled with high accuracy. Therefore, in the 3D printer described in Patent Document 1 described above, the diameter of the filament is measured on the upstream side of the print head, and the measured data is used to optimize the flow of the resin material and to control printing. .

Japanese Patent Publication No. 2016-501136

By the way, the ejection amount of the resin material ejected from the print head may not be the intended ejection amount due to abrasion of the print head, temperature variation of the melted resin material, and the like. However, since the 3D printer described in Patent Document 1 measures the diameter of the filament on the upstream side of the print head, there is a problem that control that avoids the above variations cannot be performed. Therefore, there is a problem that the accuracy of modeling is lowered.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a 3D printer capable of forming a three-dimensional object with high accuracy by accurately controlling the discharge amount of a resin material.

(1) A 3D printer provided to solve the above-described problems is a 3D printer that forms a three-dimensional model by heating and melting resin materials and laminating them. a resin ejection unit that ejects, a resin supply unit that supplies the resin material toward the resin ejection unit at a predetermined supply speed, a measurement unit that measures the ejection width of the resin material ejected from the resin ejection unit; a control unit for controlling a resin supply speed of the resin supply unit, the control unit controlling a discharge width corresponding to the discharge amount based on the discharge amount of the resin material scheduled to be discharged calculated in advance; and the measured ejection width measured by the measurement unit, the supply speed of the resin material supplied from the resin supply unit is controlled based on the correlation between the calculated ejection width calculated as is.

The 3D printer of the present invention described above can acquire the measured ejection width by measuring the ejection width of the resin material ejected from the resin ejection part by the measuring part. Further, the above-described 3D printer of the present invention can calculate a calculated ejection width as an ejection width corresponding to the ejection amount based on the ejection amount of the resin material to be ejected calculated in advance. Therefore, it is possible to obtain a correlation based on the calculated ejection width and the measured ejection width. Therefore, the supply speed of the resin material supplied from the resin supply section can be controlled based on the correlation. Further, it is possible to perform highly accurate resin material supply control based on the actual discharge amount of the resin material. As a result, it is possible to perform highly accurate resin material supply control in consideration of the wear of the resin discharge portion (also referred to as a nozzle) and the temperature variation of the resin material. In addition, it is possible to form a modeled object with high accuracy.

Here, as the resin material, in addition to heat-meltable filaments, various forms such as pellets can be used. Various measuring devices such as a camera and an optical sensor can be used for the measuring unit. In addition, the controller can be provided not only with a single controller but also with a plurality of controllers.

(2) In the above-described 3D printer of the present invention, the controller preferably controls the supply speed of the resin material so that the difference between the calculated ejection width and the measured ejection width is reduced.

According to this configuration, it is possible to control the supply speed of the resin material by a simple calculation of obtaining the difference between the calculated ejection width and the measured ejection width. Therefore, it is possible to reduce the burden on the control section, and it is expected that the response of the control will be increased.

(3) In the 3D printer of the present invention described above, the measurement unit includes an imaging unit capable of imaging the resin material discharged from the resin discharge unit, and the captured image captured by the imaging unit is an image. It is preferable to provide an image processing unit that calculates the ejection width by processing.

The 3D printer of the present invention described above can calculate the ejection width based on the captured image captured by the imaging unit. Therefore, since the imaging section can be arranged at a position spaced apart from the resin ejection section, interference with the resin ejection section can be suppressed. Here, various cameras such as an infrared camera can be used as the imaging unit. It should be noted that the imaging unit may be provided not only singularly but also plurally. Further, the image capturing unit may capture images not only from one direction but also from a plurality of directions. Various image processing techniques can be used for image processing in the image processing unit. Further, the image processing unit can be of various types, such as one shared with the control unit or provided as a separate image processing device.

(4) In the 3D printer of the present invention described above, the imaging unit is arranged at the same height as the opening surface of the ejection port in the resin ejection unit or above the opening surface, and the imaging unit is preferably performed from above the resin material discharged from the resin discharge portion.

According to such a configuration, it is possible to suppress interference between the imaging section and the resin ejection section. In addition, the captured image can be obtained by the imaging section with high accuracy without being blocked by the resin discharge section.

(5) In the 3D printer of the present invention described above, the resin supply unit has a motor that supplies the resin material toward the resin discharge unit, and the control unit controls the rotation speed of the motor. By doing so, control may be performed to reduce the difference between the calculated ejection width and the measured ejection width.

According to such a configuration, it is possible to control the supply of the resin material by controlling the rotational speed of the motor. As a result, it is possible to easily and accurately control the supply of the resin material. Here, when a filament is used as the resin material, a transport roller for transporting the filament may be connected to a motor, and the number of rotations of the transport roller may be controlled by the motor. The resin material may be in the form of pellets instead of filaments. In such a case, the supply of the resin material can be controlled in the same manner as the filament by controlling the number of revolutions of the screw that melts and extrudes the pellets by means of a motor.

ADVANTAGE OF THE INVENTION According to this invention, the 3D printer which can model a three-dimensional object with good precision can be provided by controlling the discharge amount of a resin material correctly.

It is an explanatory view showing one embodiment of the 3D printer of the present invention. FIG. 4 is a flow chart of resin material supply control in the 3D printer of the present invention.

First, an embodiment of a 3D printer 1 according to the present invention will be described in detail with reference to FIG. It should be noted that, in the drawings, the resin discharge part 10, the diameter of the resin material 2, the layered thickness of the modeled object 2a, and the like are exaggerated for easy understanding.

The 3D printer 1 includes a resin ejection section 10 that ejects the resin material 2 that has been heated and melted, a table section 20 that supports the ejected resin material 2, and a resin supply section 30 that supplies the resin material 2. there is In addition to the above, the 3D printer 1 includes a measurement unit 40 that measures the ejection width of the resin material 2 ejected from the resin ejection unit 10, a control unit 50 that performs various controls of the 3D printer 1, and the like.

A thermoplastic resin that softens when heated is used as the resin material 2 . As the thermoplastic resin, any material that can be extruded can be used, and an appropriate material can be selected. For example, acrylonitrile-butadiene-styrene copolymer resin (ABS resin), polycarbonate, nylon and the like can be used. Moreover, the thermoplastic resin can be appropriately mixed with additives, colorants, and the like. Also, the resin material 2 may be appropriately coated with a coating agent or the like. In this embodiment, a case where the resin material 2 formed in a filament shape is used will be described as an example. can use things.

The resin discharge part 10 is equipped with a heater (not shown) inside, and can melt the supplied resin material 2 . The resin discharge part 10 has a nozzle-shaped tip, and can discharge the melted resin material 2 from the tip. Here, the opening diameter (also referred to as nozzle diameter) of the ejection port 11 of the resin ejection section 10 is, for example, 0.2 to 1 mm, and the ejection width can be changed according to the opening diameter. Further, the resin discharge section 10 can be moved horizontally and vertically by an appropriate drive source (not shown). In addition, the resin discharge section 10 can sequentially stack the resin material 2 under the control of the control section 50, which will be described later.

The table portion 20 supports the discharged resin material 2 and is formed in, for example, a rectangular shape. Further, in this embodiment, the table section 20 is fixed on a machine stand (not shown), and modeling is performed by moving the resin discharge section 10 . The table section 20 is equipped with a heater (not shown) inside, and can heat the laminated resin material 2 . Various types of heaters can be used, such as a sheet-like heater and a plurality of rod-like heaters. The temperature of the table section 20 can be controlled by the control section 50, which will be described later. The table portion 20 is controlled to a temperature that does not melt the laminated resin material 2 . The table portion 20 may be movable relative to the resin discharge portion 10, or one or both of the resin discharge portion 10 and the table portion 20 may be movable according to the molding.

The resin supply unit 30 includes a pair of conveying rollers 32, 32, a motor 31 for rotating the conveying roller 32, and the like. The transport rollers 32, 32 can pinch the resin material 2 supplied as filaments. At least one of the transport rollers 32, 32 is connected to the rotating shaft of the motor 31, and the two transport rollers 32, 32 rotate synchronously via an appropriate mechanism (not shown). As a result, the resin material 2 sandwiched between the conveying rollers 32 and 32 is supplied toward the resin discharge section 10 .

The motor 31 is connected to a control section 50 which will be described later, and the rotation speed is controlled according to commands from the control section 50 . By controlling the rotation speed of the motor 31, the rotation speeds of the conveying rollers 32, 32 are controlled. Thereby, the resin material 2 can be supplied toward the resin discharge part 10 at a predetermined supply speed. When using the resin material 2 in the form of pellets, a screw pump may be provided instead of the conveying roller 32, and the rotation speed of the screw of the screw pump may be controlled.

The measurement unit 40 has a camera 41 as an imaging unit and an image processing unit 42 . In this embodiment, the camera 41 is arranged above the opening surface of the ejection port 11 in the resin ejection section 10 . The camera 41 is composed of, for example, an infrared camera, and can take an image of the resin material 2 discharged from the discharge port 11 of the resin discharge section 10 from above. As a result, the captured image of the discharged resin material 2 is acquired in the measurement unit 40 . As described above, in the 3D printer 1 of the present invention, the camera 41 can be arranged at a position spaced apart from the resin ejection section 10, so interference with the resin ejection section 10 can be suppressed. In addition, the captured image can be obtained by the camera 41 with high accuracy without being blocked by the resin discharge section 10 .

A captured image captured by the camera 41 is transmitted to the image processing section 51 . In addition, the camera 41 can be provided at the same height as the opening surface of the ejection port 11 in the resin ejection section 10, for example. Even in such a case, the resin material 2 ejected from the ejection port 11 can be imaged from above in the same manner as described above. Moreover, the camera 41 can employ not only an infrared camera but also various cameras. For example, the camera 41 can be an endoscope.

The image processing unit 42 is composed of a microcomputer or the like, and can perform arithmetic processing on the captured image acquired by the measurement unit 40 . In this embodiment, an example in which the image processing unit 42 is incorporated in a control unit 50 to be described later will be described. The image processing unit 42 performs image processing on the captured image of the resin material 2 captured obliquely from above using an appropriate image processing method. Accordingly, the image processing unit 42 can calculate the width (also referred to as ejection width) of the resin material 2 in the direction along the opening surface of the ejection port 11 . Accordingly, the measurement unit 40 can acquire the calculated ejection width as the measured ejection width W1. Note that the image processing unit 42 may be provided independently of the control unit 50 instead of being incorporated in the control unit 50 .

The control unit 50 is formed by a microcomputer or the like, and can perform various kinds of arithmetic processing. The control unit 50 can appropriately control the resin discharge unit 10 and the like according to an incorporated program for slicing.

The control unit 50 can control horizontal and vertical movement and movement speed of the resin discharge unit 10 based on 3D data input in advance. In addition to the above, the resin discharge section 10 can control the heating temperature of the resin discharge section 10 and the like. In addition to controlling the movement of the resin discharger 10 , the controller 50 can also control the discharge amount of the resin material 2 discharged from the resin discharger 10 . As a result, the modeled object 2a (including the support structure that supports the modeled object 2a) can be formed based on the 3D data. Note that the support structure (not shown) may be formed to support, for example, when the modeled object 2a has a hanging portion or an overhanging portion separated from the table portion 20. FIG.

The control section 50 can control the table section 20 . The control unit 50 can control the heater (not shown) provided on the table unit 20 to adjust the temperature of the table unit 20 . The controller 50 can also control the temperature for heating the resin discharger 10 and the discharge amount of the resin material 2 . The control of the discharge amount of the resin material 2 will be described in detail below.

The control unit 50 calculates in advance the ejection amount of the resin material 2 to be ejected based on the position information of the resin ejection unit 10 and the table unit 20, the heating temperature of the resin ejection unit 10, and the like. Further, the control unit 50 calculates a calculated ejection width W2 as an ejection width corresponding to the ejection amount based on the calculated ejection amount. The control unit 50 controls the resin supply speed of the resin material 2 supplied from the resin supply unit 30 based on the correlation between the calculated ejection width W2 and the measured ejection width W1 measured by the measurement unit 40 . Specifically, the controller 50 controls the rotation speed of the motor 31 so that the difference D between the calculated ejection width W2 and the measured ejection width W1 is reduced. As a result, the number of rotations of the conveying rollers 32, 32 is controlled, and the resin supply speed of the resin material 2 supplied from the resin supply section 30 is controlled.

Details of the control of the rotation speed of the motor 31 will be described based on the control flow described later. The correlation described above can be obtained based on the results of experiments conducted in advance. Thus, the 3D printer 1 of the present invention can control the resin supply speed of the resin material 2 supplied from the resin supply section 30 based on the correlation. Therefore, it is possible to control the supply of the resin material 2 with high accuracy based on the actual discharge amount of the resin material 2 . As a result, it is possible to control the supply of the resin material 2 with high precision in consideration of the wear of the resin discharge section 10 and the temperature variation of the resin material 2 . In addition, the modeled object 2a can be modeled with high accuracy.

By feedback control, the resin supply speed of the resin material 2 can be controlled while sequentially feeding back various information such as the measured discharge width W1, the position information of the resin discharge section 10, temperature data, and the like. The control unit 50 can also control the entire 3D printer 1 in addition to the control described above.

An embodiment of the configuration of the 3D printer 1 according to the present invention has been described above. Next, the supply control of the resin material 2 by the control unit 50 will be described based on the flowchart of FIG. 2 .

≪Regarding resin material supply control≫
When the 3D printer 1 starts modeling, the camera 41 acquires a captured image of the resin material 2 discharged from the discharge port 11 of the resin discharge unit 10 (step S1).

The captured image acquired in step S1 is subjected to image processing (step S2). Subsequently, the ejection width is measured to obtain the measured ejection width W1 (step S3). Also, a calculated ejection width W2 is calculated (step S4).

When the measured ejection width W1 is obtained and the calculated ejection width W2 is calculated, the difference D is obtained by subtracting the measured ejection width W1 from the calculated ejection width W2. Further, it is determined whether the difference D is positive (+) or negative (-) (step S5).

If the difference D is negative (-) in step S5, control is performed to reduce the rotational speed of the motor 31 (step S6). That is, the controller 50 performs control to reduce the difference D. FIG. As a result, the number of rotations of the conveying rollers 32, 32 is reduced, and the speed at which the resin material 2 is supplied from the resin discharger 10 is reduced. When the processing in step S6 is completed, the processing from step S1 is repeated again. It should be noted that the process may be stopped when the modeling of the modeled object 2a is completed.

If the difference D is positive (+) in step S5, control is performed to increase the rotation speed of the motor 31 (step S7). That is, the controller 50 performs control to reduce the difference D. FIG. As a result, the number of rotations of the conveying rollers 32, 32 increases, and the speed at which the resin material 2 is supplied from the resin discharger 10 increases. When the processing in step S7 is completed, the processing from step S1 is repeated again. It should be noted that the process may be stopped when the modeling of the modeled object 2a is completed.

As described above, the control unit 50 in the 3D printer 1 of the present invention can control the resin supply speed of the resin material 2 by a simple calculation of obtaining the difference D between the calculated ejection width W2 and the measured ejection width W1. can. Therefore, the burden on the control unit 50 can be reduced, and the responsiveness of control can be increased.

The above is the flow of the supply operation of the resin material 2 in the 3D printer 1 of the present invention, but the 3D printer 1 of the present invention is not limited to the above-described embodiment, and various modifications can be made. .

In the present embodiment, the case where the resin material 2 is formed in a filament shape is described as an example, but the resin material 2 is not limited to a filament shape. can be used. Also, the configuration of the 3D printer used for modeling is not limited to that of the embodiment described above, and various 3D printers can be used. Further, the shape and size of the modeled object 2a are not limited to those of the embodiment described above, and various shapes and sizes are possible. Moreover, an appropriate support structure can be used according to the form of the modeled object 2a.

The resin discharge part 10 is not limited to the embodiment described above, and various shapes can be adopted according to the characteristics of the resin material 2 to be used. Moreover, it is also possible to provide a plurality of resin ejection portions 10 . Also, the heating temperature of the resin discharge portion 10 is controlled to various temperatures according to the characteristics of the resin material 2 .

In addition, although the table section 20 is fixed in this embodiment, it may be made vertically movable or horizontally movable as appropriate. Further, in the present embodiment, the table portion 20 is fixed and the resin discharge portion 10 is moved to form a model. Both 10 and table section 20 may be driven. Moreover, although it is preferable that the table portion 20 is heated, it may not be heated.

In addition, although the motor 31 is used for the resin supply unit 30 in the present embodiment, various drive sources and mechanisms can be employed as long as the supply control of the resin material 2 is possible. Various types of resin supply unit 30 can be used according to the shape and size of the resin material 2 . For example, when the resin material 2 is in the form of pellets, a screw pump may be used instead of the conveying rollers 32 . In such a case, instead of controlling the rotation of the conveying roller 32, the rotation speed of the screw of the screw pump may be controlled.

Further, in the present embodiment, the camera 41 (imaging unit 41) is provided in the measurement unit 40, but instead of the camera 41 or together with the camera 41, various measurement devices can be provided. For example, it is possible to use an optical sensor for the measuring unit 40 . In such a case, the sensor should be provided so as not to interfere with the resin discharge section 10, the modeled object 2a, the table section 20, and the like. Further, although one camera 41 is provided in this embodiment, a plurality of cameras 41 may be provided.

In addition, in the present embodiment, the camera 41 (imaging unit 41) is arranged above the opening surface of the ejection port 11 in the resin ejection unit 10, but the position where the camera 41 is provided is It is not limited and can be provided at various positions. In such a case, the camera 41 should be provided so as not to interfere with the resin discharge section 10, the modeled object 2a, the table section 20, and the like. For example, the camera 41 may be provided at the same height as the opening surface of the ejection port 11 in the resin ejection section 10 or at the side of the ejection port 11 . Further, although an infrared camera is used as the camera 41 in this embodiment, various cameras such as an endoscope can be used as the camera 41 . Further, in the present embodiment, the captured image of the resin material 2 is directly acquired by the camera 41, but the captured image may be acquired indirectly. Further, the imaging by the imaging unit 41 can be performed not only from above the resin material 2 but also from various directions.

In this embodiment, the image processing unit 42 is incorporated in the control unit 50, but the image processing unit 42 can be provided at various positions. For example, the image processing section 42 may be built in the camera 41 . Further, image processing may be performed by the control unit 50 . Various techniques can be used for the image processing in the image processing unit 42 . Further, in the present embodiment, the measured ejection width W1 is obtained by image processing, but the image processing section 42 can be eliminated and the measured ejection width W1 can be directly measured.

In this embodiment, the controller 50 controls the resin supply speed of the resin material 2 supplied from the resin supply unit 30 based on the correlation between the calculated ejection width W2 and the measured ejection width W1. However, the correlation used in the present invention may be appropriately changed according to the characteristics of the resin material 2, the shape of the resin supply section 30, and the like. Moreover, the controller 50 may be provided not only singularly but also plurally for each function.

In this embodiment, the controller 50 controls the resin supply speed of the resin material 2 so that the difference D between the calculated ejection width W2 and the measured ejection width W1 is reduced. Alternatively, the resin supply speed of the resin material 2 may be controlled. In such a case, the resin supply speed of the resin material 2 may be controlled based on another correlation between the calculated discharge width W2 and the measured discharge width W1. Further, in the present embodiment, the controller 50 performs control to reduce the difference D by controlling the number of rotations of the motor 31. , the resin supply speed of the resin material 2 may be controlled using control means corresponding to each mechanism.

Various embodiments and modifications of the 3D printer according to the present invention have been described above, but the present invention is not limited to the embodiments and modifications described above, and does not depart from the scope of the claims. One of ordinary skill in the art will readily recognize that other embodiments are possible from the teachings and spirit of the scope.

The 3D printer of the present invention can be used for various fused lamination type 3D printers.

Reference Signs List 1: 3D printer 2: Resin material 2a: Modeled object 10: Resin discharge part (nozzle)
11: discharge port (opening)
20: Table 30: Resin supply unit 31: Motor 32: Conveying roller 40: Measuring unit 41: Imaging unit 42: Image processing unit 50: Control unit 51: Image processing unit W1: Measured ejection width W2: Calculated ejection width D: Difference

Claims (3)

A 3D printer that forms a three-dimensional model by heating and melting resin materials and laminating them,
a resin discharge unit for discharging the resin material melted by heating;
a resin supply unit that supplies the resin material toward the resin discharge unit at a predetermined supply speed;
a measurement unit for measuring a discharge width of the resin material discharged from the resin discharge unit;
a control unit for controlling the resin supply speed of the resin supply unit,
The control unit
Based on a correlation between a calculated ejection width calculated as an ejection width corresponding to the ejection amount based on the ejection amount of the resin material scheduled to be ejected calculated in advance and the measured ejection width measured by the measurement unit. and controlling the supply speed of the resin material supplied from the resin supply unit. 2. The 3D printer according to claim 1, wherein the controller controls the supply speed of the resin material so as to reduce a difference between the calculated ejection width and the measured ejection width. The measurement unit includes an imaging unit capable of imaging the resin material discharged from the resin discharge unit,
3. The 3D printer according to claim 1, further comprising an image processing unit that calculates the ejection width by processing an image captured by the imaging unit.

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