3D printer

Abstract

To provide a three-dimensional printer capable of suppressing a molding defect by stably supplying a filament (resin material) to a resin discharge part.SOLUTION: A three-dimensional printer 1 that forms a three-dimensional object 3 by heating and melting a resin material supplied as a filament 2 and laminating them includes: a holding part 10 around which the filament 2 is wound; a first feeding part 20 that sends out the filament 2 from the holding part 10; a resin discharge part 45 that discharges the heated and melted resin material; a second feeding part 50 that is provided on a downstream side of the first feeding part 20 and supplies the filament 2 to the resin discharge part 45; a passing position detection part 35 provided between the first feeding part 20 and the second feeding part 50 and capable of detecting the passing position of the filament 2; and a control part 60 that controls a feed amount of the filament 2 between the first feeding part 20 and the second feeding part 50 based on the passing position of the filament detected by the passing position detection part 35.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a 3D printer. More specifically, it relates to a 3D printer that forms a three-dimensional object by heating and melting a resin material and laminating it.

Background Art

[0002] Conventionally, a 3D printer using a fused deposition modeling (FDM) method that forms a three-dimensional object by heating and melting a resin material and laminating it is known. The above-mentioned 3D printer is configured to unwind a filament (resin material) wound around a reel a plurality of times from the reel and melt the filament to sequentially laminate it to form a three-dimensional object (for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] By the way, the 3D printer described in Patent Document 1 mentioned above passes the filament supplied from the reel through a guide tube and guides the filament to the resin discharge portion.

[0005] However, with the 3D printer described in Patent Document 1 mentioned above, if the device is to be made larger, there is a concern that the filament supply path will become longer, increasing the contact resistance between the filament and the inner wall of the tube. As a result, there is a problem of defective printing due to the filament twisting or breaking. In addition, there is a problem of high cost, such as the need for an expensive motor with a large transport force to overcome the above contact resistance. In particular, as the filament supply path becomes longer, there is a concern that the above contact resistance will increase even further as many curves are created in the filament supply path. Furthermore, in the above 3D printer, the filament is supplied wound on a reel, so there is a concern that the filament will develop a curl, further increasing the above contact resistance.

[0006] Therefore, the present invention aims to provide a 3D printer that can suppress molding defects by stably supplying filament (resin material) to the resin extrusion section. [Means for solving the problem]

[0007] (1) The present invention, provided to solve the above-mentioned problems, is a 3D printer that forms a three-dimensional object by heating and melting a resin material supplied as a filament and layering it, and is characterized by comprising: a holding section around which the filament is wound multiple times; a first feeding section that feeds the filament from the holding section; a resin extrusion section that forms the object by extruding the heated and melted resin material; a second feeding section provided downstream of the first feeding section and supplying the filament to the resin extrusion section; a passage position detection section provided between the first feeding section and the second feeding section and capable of detecting the passage position of the filament; and a control section that controls the amount of filament fed between the first feeding section and the second feeding section based on the passage position of the filament detected by the passage position detection section.

[0008] In the aforementioned 3D printer, the amount of filament fed between the first and second feed sections is controlled based on the filament's passage position detected by the passage position detection unit. Therefore, the aforementioned 3D printer can properly guide the filament to the resin extrusion section, eliminating the need for a guide tube. As a result, the aforementioned 3D printer can eliminate contact resistance on the filament, thereby suppressing filament twisting and breakage. Furthermore, since the aforementioned 3D printer can properly guide the filament to the resin extrusion section without requiring a large motor or other drive source, cost reduction can be expected. In addition, because the amount of filament fed is properly controlled, the aforementioned 3D printer can stably supply filament while suppressing excessive slack or excessive tension on the filament.

[0009] (2) The 3D printer of the present invention described above is preferably such that the passage position detection unit detects the passage position of the filament in a direction intersecting the filament feeding direction at an intermediate position in the filament feeding direction.

[0010] By adopting this configuration, the 3D printer described above can accurately and easily detect the filament's path. As a result, the 3D printer can be constructed simply and inexpensively, which is expected to improve the stability of the filament supply.

[0011] Here, as described above, the 3D printer of the present invention varies the amount of filament fed based on the passage position detected by the passage position detection unit. Therefore, if the configuration can suppress fluctuations in the passage position of the filament depending on the strength of the coiling imparted to the filament, the amount of filament fed can be made even more appropriate.

[0012] (3) Based on the above findings, the 3D printer of the present invention described above is preferably characterized by having a coil-reducing unit for reducing coiling of the filament, located upstream of the passage position detection unit in the filament feeding direction.

[0013] As described above, the 3D printer of the present invention, with this configuration, can reduce the fluctuation in the position at which the filament passes through the passage position detection unit, which is affected by the strength of the coil memory attached to the filament. As a result, the 3D printer of the present invention can achieve a more precise filament feed rate.

[0014] (4) The 3D printer of the present invention described above may be provided between the first feeding unit and the passage position detection unit, and may include a coiling relief unit that relieves the coiling of the filament by applying pressure to the filament from a direction intersecting the filament supply direction.

[0015] By adopting this configuration, the 3D printer described above can effectively mitigate, for example, the coiling of the filament that occurs on the filament supply reel or filament feeding path. As a result, the 3D printer can supply the filament to the resin extrusion section more stably, thereby more effectively suppressing filament breakage and other damage.

[0016] (5) The control unit in the 3D printer of the present invention described above may control the amount of filament fed between the first feed unit and the second feed unit so that the filament forms a predetermined slack between the first feed unit and the second feed unit.

[0017] By adopting this configuration, the 3D printer described above can create appropriate slack in the filament between the first and second feed sections. Therefore, the 3D printer described above can suppress excessive tension on the filament. As a result, the 3D printer described above can supply the filament to the resin extrusion section more stably, and thus more effectively suppress filament breakage and other damage.

[0018] (6) The 3D printer of the present invention described above may be provided with a pair of guide rollers located between the coil-reducing section and the passage position detection section, which guide the filament in a predetermined direction in the passage position detection section.

[0019] The 3D printer described above, with this configuration, can stabilize the position of the filament as it passes through the position detection unit. As a result, the 3D printer can improve the detection accuracy of the position detection unit, thereby further stabilizing the filament supply. Here, it is preferable that the pair of guide rollers are formed in a curved shape so that the roller surfaces through which the filament passes are spaced apart from each other. This prevents excessive load from being placed on the filament, thus preventing breakage or other damage to the filament.

[0020] (7) The control unit in the 3D printer of the present invention described above controls the amount of filament fed between the first feed unit and the second feed unit when the passage position detection unit detects that the filament has been displaced relative to a predetermined passage position of the filament to the side in which the tension of the filament is relieved, and controls the amount of filament fed between the first feed unit and the second feed unit when the passage position detection unit detects that the filament has been displaced relative to a predetermined passage path of the filament to the side in which the tension of the filament is increased.

[0021] The 3D printer described above, by adopting this configuration, can easily detect the filament's passage position, thus simplifying the 3D printer's design. Furthermore, the 3D printer described above can supply filament at an appropriate feed rate according to the filament's passage position in the passage position detection unit, thereby suppressing excessive load on the filament. As a result, the 3D printer described above can further stabilize the filament supply. Here, the filament feed rate should be such that a predetermined slack is formed in the filament between the first and second feed sections. [Effect of the Invention]

[0022] The present invention can provide a 3D printer capable of suppressing molding defects by stably supplying a filament (resin material) to a resin discharge part. [Brief Description of the Drawings]

[0023] [Figure 1] It is a schematic overall view of a 3D printer according to an embodiment of the present invention. [Figure 2] (a) is a side view taken along the arrow in the A-A direction of FIG. 1, and (b) is a side view taken along the arrow in the B-B direction of FIG. 1. [Figure 3] It is an explanatory diagram of a passing position detection part constituting the 3D printer of the present invention. [Figure 4] It is an operation flowchart of a 3D printer according to an embodiment of the present invention. [Modes for Carrying Out the Invention]

[0024] Hereinafter, a 3D printer 1 according to an embodiment of the present invention will be described with reference to FIGS. 1 to 3. In the present embodiment, a case where the 3D printer 1 forms a three-dimensional molded object 3 by heating and melting a resin material supplied as a filament 2 and laminating it (also referred to as a fused deposition modeling method (FDM method)) will be described.

[0025] As shown in FIG. 1, the 3D printer 1 includes a reel 10 (also referred to as a holding part 10) around which a large number of filaments 2 are wound, and a first motor 20 (also referred to as a first feeding part 20) that feeds the filament 2 out of the reel 10. Further, the 3D printer 1 includes a curl relaxation part 25, a pair of guide rollers 30, 30 that guide the filament 2 in a predetermined direction, a passing position detection part 35, a guide member 40, and a resin discharge part 45. Further, in addition to the above, the 3D printer 1 includes a second feeding part 50 that supplies the filament 2 to the resin discharge part 45, an extruder 55, a table part 56, a control part 60, and the like.

[0026] The filament 2 of the present invention uses a thermoplastic resin that softens upon heating. The thermoplastic resin can be any extruded material, and any suitable material can be selected. For example, acrylonitrile-butadiene-styrene copolymer resin (ABS resin), polycarbonate, nylon, etc. can be used. In addition, the thermoplastic resin can be mixed with additives, colorants, etc. as appropriate. Furthermore, the filament 2 can be used coated with a coating agent, etc. as appropriate.

[0027] As shown in Figure 2(a), the reel 10 has multiple turns of filament 2 wound around it. The reel 10 is supported by a shaft 12 and can rotate integrally with the shaft 12. The reel 10 is also rotatably supported via the shaft 12 by a pair of support frames 11, 11 that hang down from the ceiling 4. A first motor 20, which serves as the first feed unit 20, is connected to the shaft 12 of the reel 10. Therefore, the reel 10 is rotatable relative to the support frames 11, 11 by rotating the first motor 20. In addition, the filament 2 is fed out from the reel 10 as the reel 10 rotates. The first motor 20 is connected to a control unit 60, which will be described later, and the rotation speed is controlled by the control unit 60.

[0028] As shown in Figure 1, the coiling relief section 25 is provided between the first motor 20 and the passage position detection section 35, which will be described later. The coiling relief section 25 includes a folded member 26 and a pressurizing member 27, etc., which is positioned opposite the folded member 26.

[0029] The folding member 26 curves and folds the filament 2 in the direction opposite to the coiling tendency (the direction that eliminates the coiling tendency). The folding member 26 can have any suitable shape or structure, such as a rectangular parallelepiped, conical, or tapered shape, but in this embodiment it has a wedge shape. The folding member 26 is positioned so that its acutely angled tip intersects with the direction in which the filament 2 is supplied. The filament 2 is supplied along the outer circumference of the folding member 26, curves towards the rear (the direction that eliminates the coiling tendency of the filament 2) at the tip of the folding member 26, and is then guided downwards. The tip of the folding member 26 is formed to be flat or curved so that the filament 2 is not damaged even if it comes into contact with it.

[0030] The pressurizing member 27 is formed as a plate material having a flat surface. The pressurizing member 27 is positioned to face the tip side of the folded member 26 via the filament 2. The pressurizing member 27 can also be brought closer to the folded member 26 by tightening a screw member such as a wing nut. This allows the pressurizing member 27 to press the filament 2 against the folded member 26 and apply pressure. In other words, the coil-reducing part 25 can apply pressure to the filament 2 in a direction that eliminates the coil-reducing of the filament 2. This reduces the coil-reducing of the filament 2. Various forms of the pressurizing member 27 can be used, such as one in which the distance to the folded member 26 is adjusted manually, or one in which the distance to the folded member 26 is automatically adjusted by the control unit 60. The coil-reducing part 25 may be provided as needed, and a configuration without the coil-reducing part 25 is also possible.

[0031] A pair of guide rollers 30, 30 are positioned downstream of the coil memory reduction section 25. The guide rollers 30, 30 are made from materials such as resin or rubber. The guide rollers 30, 30 can guide the filament 2 in a predetermined direction in the passage position detection section 35. Furthermore, as shown in Figure 2(b), the guide rollers 30, 30 are formed in a curved shape so that the roller surfaces 31, 31 that allow the filament 2 to pass are spaced apart from each other. This prevents excessive load from being placed on the filament 2, thereby preventing breakage of the filament 2.

[0032] In this way, the guide rollers 30, 30 can stabilize the position of the filament 2 as it passes through the passage position detection unit 35. As a result, the guide rollers 30, 30 can improve the detection accuracy of the passage position detection unit 35, which will be described later, and thus further stabilize the supply of the filament 2.

[0033] The passage position detection unit 35 is positioned between the first motor 20 and the second motor 50. The passage position detection unit 35 is configured to detect the passage position of the filament 2 in a direction intersecting the filament 2's feeding direction at an intermediate position in the filament 2's feeding direction.

[0034] In this embodiment, the passage position detection unit 35 uses, for example, a ring-shaped passage-type sensor (hereinafter also referred to as the passage-type sensor 35). As shown in Figure 1, the passage-type sensor 35 is formed as a rectangular ring having an opening 36 on its inside. The filament 2 passes through the opening 36 of the passage-type sensor 35. The passage-type sensor 35 can detect the passage position (position change) of the filament 2 relative to the opening 36 by the change in the induced current generated in an induction coil (not shown) provided around the opening 36. The passage position information of the filament 2 detected by the passage-type sensor 35 is sent to the control unit 60, which will be described later. Note that the passage-type sensor 35 can be replaced with various sensors capable of detecting position changes instead of one that utilizes induced current. For example, the passage position detection unit 35 can use one that optically detects the position change of the filament 2. Details of the changes in the detection state in the passage position detection unit 35 will be described later.

[0035] The guide member 40 is formed, for example, in a cylindrical shape, with the filament 2 passing through its interior. The guide member 40 is designed to guide the filament 2 toward a pair of pinch rollers 51, 51 positioned downstream of the guide member 40.

[0036] The pinch rollers 51, 51 are formed from materials such as resin or rubber. The pinch rollers 51, 51 can grip the filament 2. A second motor (also referred to as the second motor 50) is connected to the pinch rollers 51, 51 as the second feed unit 50. The pinch rollers 51, 51 rotate due to the driving force of the second motor 50, and can feed the filament 2 toward the extruder 55.

[0037] The second motor 50 is positioned downstream of the first motor 20 in the filament supply direction. The second motor 50 is connected to a control unit 60, which will be described later, and its rotational speed is controlled by the control unit 60. As will be described in detail later, the second motor 50 can supply the filament 2 at a predetermined feed rate due to the difference in feed speed between it and the first motor 20.

[0038] The extruder 55 guides the filament 2 and also heats and melts the filament 2. The extruder 55 can supply the heated and melted filament 2 to the resin extrusion unit 45. The temperature of the extruder 55 is controlled by the control unit 60.

[0039] The resin extrusion unit 45 is equipped with a heater (not shown) inside, which can heat and melt the supplied filament 2. The tip of the resin extrusion unit 45 is formed in a nozzle shape, and the heated and melted filament 2 can be extruded from the tip. Here, the opening diameter of the extrusion port of the resin extrusion unit 45 (also referred to as the nozzle diameter) is, for example, 0.2 to 1 mm, and the extrusion width can be changed according to the opening diameter. The resin extrusion unit 45 can also move horizontally and vertically with an appropriate drive source (not shown). Furthermore, the resin extrusion unit 45 can sequentially stack the filament 2 to form a three-dimensional object 3 under the control of the control unit 60, which will be described later.

[0040] The table section 56 supports the filament 2 extruded from the resin extrusion section 45 and is formed, for example, in a rectangular shape. In this embodiment, the table section 56 is fixed on a machine base (not shown), and molding is performed by the movement of the resin extrusion section 45. The table section 56 is equipped with a heater (not shown) inside, which can heat the layered filament 2. Various types of heaters can be used, such as those formed in the shape of a sheet or multiple rod-shaped heaters arranged together. The temperature of the table section 56 can be controlled by a control unit 60, which will be described later. The temperature of the table section 56 is controlled to a temperature that does not cause the layered filament 2 to melt. The table section 56 may be movable relative to the resin extrusion section 45, and either the resin extrusion section 45 or the table section 56, or both, may move according to the molding process.

[0041] The control unit 60 is formed using a microcontroller or the like and can perform various controls on the 3D printer 1. The control unit 60 can also control the resin extrusion unit 45 and other components using a slicing program that is appropriately incorporated. Note that the control unit 60 is not limited to a single unit; for example, multiple units may be provided for each control device.

[0042] The control unit 60 can control the amount of filament 2 fed between the first motor 20 and the second feed unit 50 based on the passage position of the filament 2 detected by the passage position detection unit 35. Details of the control related to the amount of filament 2 fed will be described later.

[0043] The control unit 60 can control the horizontal and vertical movement and movement speed of the resin extrusion unit 45 based on pre-inputted 3D data. In addition, the control unit 60 can control the heating temperature of the resin extrusion unit 45, etc. Furthermore, along with controlling the movement of the resin extrusion unit 45, the control unit 60 can control the amount of filament 2 extruded from the resin extrusion unit 45. Through these means, the 3D printer 1 can form an object 3 based on the 3D data.

[0044] The control unit 60 can control the table section 56. The control unit 60 can adjust the temperature of the table section 56 by controlling a heater (not shown) provided on the table section 56. The control unit 60 can also control the temperature at which the resin extrusion section 45 is heated and the amount of filament 2 extruded.

[0045] Next, the control of the filament feed amount in the control unit 60 will be explained in detail below with reference to Figure 3. In Figure 3, the left side of the diagram represents the negative (minus) side of the filament 2's slack, and the right side represents the positive (plus) side of the filament 2's slack.

[0046] Figure 3(a) shows the case where the filament 2 passing through the through-type sensor 35 is in a steady position (steady state). In the steady state, a predetermined slack (slack due to an appropriate amount of slack) is formed in the filament 2 between the first motor 20 and the second motor 50 (in this embodiment, the guide rollers 30, 30 and the guide member 40). This slack due to an appropriate amount of slack can be formed by controlling the difference in feed speed between the first motor 20 and the second motor 50 to a predetermined speed. In other words, this slack due to an appropriate amount of slack can be formed by controlling the amount of filament 2 fed between the first motor 20 and the second motor 50.

[0047] Figure 3(b) shows the state in which the passage position of the filament 2 passing through the through-type sensor 35 is located on the negative side (slack state). In the slack state, the filament 2 is pulled by tension, and the passage position of the filament 2 shifts to the left side of the opening 36 shown in the figure. At this time, the control unit 60 controls the feed speed of the first motor 20 to increase. That is, the control unit 60 controls the amount of filament 2 fed between the first motor 20 and the second motor 50 to increase. This reduces the load on the filament 2.

[0048] Figure 3(c) shows the state in which the filament 2 passing through the through-type sensor 35 is located on the positive side (excessive slack state). In the excessive slack state, the filament 2 is too slack, and the position of the filament 2 passing through the opening 36 is shifted to the right side in the figure (insufficient tension state). At this time, the control unit 60 controls the feed speed of the first motor 20 to decrease. That is, the control unit 60 controls the amount of filament 2 fed between the first motor 20 and the second motor 50 to decrease. This brings the slack of the filament 2 closer to an appropriate state.

[0049] As described above, the 3D printer 1 controls the amount of filament 2 fed between the first motor 20 (first feed unit 20) and the second motor 50 (second feed unit 50) based on the passage position of the filament 2 detected by the through-type sensor 35 (passage position detection unit 35). Therefore, the 3D printer 1 can properly guide the filament 2 to the resin extrusion unit 45, eliminating the need for a guide tube. This eliminates contact resistance on the filament 2, thereby suppressing twisting and breakage of the filament 2. Furthermore, since the 3D printer 1 can properly guide the filament 2 to the resin extrusion unit 45 without requiring a large motor or other drive source, cost reduction can be expected. In addition, because the amount of filament 2 fed is properly controlled, the 3D printer 1 can stably supply the filament 2 while suppressing excessive slack or excessive tension of the filament 2.

[0050] Furthermore, in this embodiment, the 3D printer 1 has a passage position detection unit 35 that detects the passage position of the filament 2 in a direction intersecting the filament 2's feeding direction at an intermediate position in the filament 2's feeding direction. Therefore, the 3D printer 1 described above can accurately and easily detect the passage position of the filament 2. As a result, the 3D printer 1 described above can be constructed simply without incurring high costs, and an improvement in the stability of the filament 2 supply can be expected.

[0051] Furthermore, the 3D printer 1 described above is equipped with a coil-reducing unit 25 that reduces coiling of the filament 2, so it can effectively reduce coiling of the filament 2 that occurs on the reel 10 or the filament 2 feed path. As a result, the 3D printer 1 can supply the filament 2 to the resin extrusion unit 45 more stably, and thus can more effectively suppress breakage of the filament 2.

[0052] Furthermore, the 3D printer 1 of this embodiment is designed to create an appropriate slack in the filament 2 between the first motor 20 and the second motor 50. Therefore, the 3D printer 1 described above can suppress excessive tension on the filament 2. As a result, the 3D printer 1 can supply the filament 2 to the resin extrusion unit 45 more stably, and thus more effectively suppress breakage of the filament 2. Note that the slack in the filament 2 between the first motor 20 and the second motor 50 may be created as needed, or it may be possible to not create such slack. The amount of slack may also be appropriately changed depending on the diameter and material of the filament 2.

[0053] Furthermore, the 3D printer 1 described above is configured to reduce the amount of filament 2 fed between the first motor 20 and the second motor 50 when the passage position detection unit 35 detects that the filament 2 has been displaced relative to a predetermined passage position in a direction where the tension of the filament 2 is relieved. Also, the 3D printer 1 described above is configured to increase the amount of filament 2 fed between the first motor 20 and the second motor 50 when the passage position detection unit 35 detects that the filament 2 has been displaced relative to a predetermined passage path in a direction where the tension of the filament 2 is increased.

[0054] Therefore, the 3D printer 1 described above can detect the passage position of the filament 2 with a simple configuration, allowing for a simple design. Furthermore, the 3D printer 1 described above can supply the filament 2 at an appropriate feed rate according to the passage position of the filament 2 detected by the passage position detection unit 35, thereby suppressing excessive load on the filament 2. As a result, the 3D printer 1 described above can further stabilize the supply of filament 2.

[0055] The above describes the configuration and effects of the 3D printer 1 of the present invention. Next, the operation flow of the 3D printer 1 will be explained in detail below with reference to Figure 4.

[0056] When the 3D printer 1 starts the process of forming the object 3, the control unit 60 first starts controlling the speed of the first motor 20 and the second motor 50 (step S1). Following the process in step S1, the feed speed of the filament 2 in the extruder 55 (rotation speed of the second motor 50) and the feed speed of the filament 2 in the reel 10 (rotation speed of the first motor 20) are synchronized (step S2).

[0057] Next, the control unit 60 determines whether or not slack in the filament 2 has been detected based on the passage position of the filament 2 detected by the passage position detection unit 35 (step S3).

[0058] If no slack in the filament 2 is detected in step S3, the process is terminated and the process returns to step S1. If slack in the filament 2 is detected in step S3, the control unit 60 determines the direction of the slack detection (step S4).

[0059] In step S4, if it is determined that the slack detection direction is positive, the rotation speed of the first motor 20 is reduced to control the amount of filament 2 fed (step S5). Once the process in step S5 is completed, speed control of the first motor 20 and the second motor 50 is terminated (step S7).

[0060] In step S4, if it is determined that the slack detection direction is negative, control is performed to increase the rotation speed of the first motor 20 and increase the amount of filament 2 fed (step S6). Once the process in step S6 is completed, speed control of the first motor 20 and the second motor 50 is terminated (step S7).

[0061] Once the process in step S7 is complete, the process returns to step S1. To terminate the printing process on 3D printer 1, simply end the series of processes after the execution of step S7.

[0062] The above describes the operation flow of the 3D printer 1 of the present invention. However, the 3D printer 1 of the present invention is not limited to the embodiments described above and can be modified in various ways.

[0063] In this embodiment, the holding unit 10 (reel 10) is supported by the ceiling 4 of a facility, but the holding unit 10 may be supported, for example, within the 3D printer 1. Also, in this embodiment, the passage position detection unit 35 detects the passage position of the filament 2 in a direction intersecting the feeding direction of the filament 2, but it is not limited to this, and the detection direction of the filament 2 in the passage position detection unit 35 can be set to various directions. Also, in this embodiment, the passage position detection unit 35 is exemplified as a ring-shaped passage-type sensor 35, but it is not limited to this, and various types of sensors can be used for the passage position detection unit 35. Furthermore, the sensor used in the passage position detection unit 35 is not limited to one that detects induced current, but can also be an optical sensor or of various other forms.

[0064] In this embodiment, the 3D printer 1 is equipped with a coil-reducing section 25, but the coil-reducing section 25 can be provided as needed, and the 3D printer 1 can be configured to have multiple coil-reducing sections 25 or to have no coil-reducing section 25 at all. Furthermore, various forms of coil-reducing sections 25 can be used. In addition, the coil-reducing section 25 can be positioned in various locations.

[0065] Furthermore, in this embodiment, the amount of filament 2 fed between the first feed section 20 and the second feed section 50 is controlled so that the filament 2 forms a predetermined slack between them. However, this slack may be provided as needed, and the device may be configured without it. Also, in this embodiment, a pair of guide rollers 30, 30 are provided between the winding memory relief section 25 and the passage position detection section 35. However, the guide rollers 30, 30 may be provided as needed, and the device may be configured without them. In addition, in this embodiment, the roller surfaces 31, 31 of the guide rollers 30, 30 are exemplified as being formed in a curved shape so as to be spaced apart from each other, but the curvature of the roller surfaces 31 can be changed as appropriate. Furthermore, various forms of guide rollers 30, 30 can be used. For example, the guide rollers 30, 30 may be designed to clamp the filament 2.

[0066] Furthermore, in this embodiment, the amount of filament 2 fed between the first motor 20 and the second motor 50 is controlled by controlling the feed speed of the first motor 20. However, the amount of filament 2 fed may also be controlled by controlling the feed speed of one or both of the first motor 20 and the second motor 50. That is, the amount of filament 2 fed may be controlled by controlling the relative feed speeds of the first motor 20 and the second motor 50. In addition, the amount of filament 2 fed can be appropriately changed depending on the configuration of the 3D printer 1.

[0067] The above describes embodiments and modifications of the 3D printer 1 according to the present invention. However, the present invention is not limited to those exemplified in the embodiments and modifications described above, and it will be readily apparent to those skilled in the art that other embodiments may exist in the spirit and teachings thereof, without departing from the scope of the claims. [Industrial applicability]

[0068] The 3D printer of the present invention can be used to fabricate various three-dimensional objects such as automobile parts. Furthermore, the 3D printer of the present invention can be used as a fused deposition modeling (FDM) 3D printer using fused filament. [Explanation of Symbols]

[0069] 1: 3D printer 2: Filament 3: Modeled object 10: Reel (holding part) 20: First motor (first feed unit) 25: Curl-reducing section 30: Guide roller 35: Passage position detection unit (passage type sensor) 45: Resin dispensing section 50: Second motor (second feed unit) 51: Pinch Roller 55: Extruder 60: Control Unit

Claims

1. A 3D printer that forms three-dimensional objects by heating and melting a resin material supplied as a filament and layering it, A holding section in which the filament is wound many times, A first feeding unit that feeds the filament from the holding unit, A resin extrusion unit that extrudes the heated and melted resin material to form the molded object, A second feeding unit is provided downstream of the first feeding unit and supplies the filament to the resin extrusion unit, A passage position detection unit is provided between the first feeding unit and the second feeding unit and is capable of detecting the passage position of the filament, The system includes a control unit that controls the amount of filament fed between the first feed unit and the second feed unit based on the filament's passage position detected by the passage position detection unit, The passage position detection unit detects the passage position of the filament in a direction intersecting the filament feeding direction at an intermediate position in the filament feeding direction. A 3D printer characterized in that the control unit controls the amount of filament fed between the first feed unit and the second feed unit so that the filament forms a predetermined slack between the first feed unit and the second feed unit.

2. The 3D printer according to Claim 1, characterized in that the control unit controls the amount of filament fed between the first feed unit and the second feed unit when the passage position detection unit detects that the filament has been displaced relative to a predetermined passage position of the filament to the side in which the tension of the filament is relieved, and controls the amount of filament fed between the first feed unit and the second feed unit when the passage position detection unit detects that the filament has been displaced relative to a predetermined passage path of the filament to the side in which the tension of the filament is increased.

3. The 3D printer according to claim 1 or 2, characterized in that the passage position detection unit is a passage-type sensor that detects the filament passage position by an induced current change or an optical position change.

4. The 3D printer according to claim 1 or 2, characterized in that a coil-reducing unit for reducing coiling of the filament is provided upstream of the passage position detection unit in the filament feeding direction.

5. The 3D printer according to claim 1 or 2, further comprising a coil-reducing unit provided between the first feeding unit and the passage position detection unit, which reduces the coiling of the filament by applying pressure to the filament from a direction intersecting the filament supply direction.

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