Three-dimensional printer

Abstract

The utility model discloses a three-dimensional printer. The three-dimensional printer comprises a printing platform; a print head; the movement mechanism is used for driving at least one of the printing head and the printing platform, so that the printing head generates displacement relative to the printing platform; the movement mechanism comprises a Z-axis movement mechanism, and the Z-axis movement mechanism comprises a lead screw, a first rotating shaft and a second rotating shaft. The driving motor is coaxially connected with an output shaft of the driving motor and is used for driving the lead screw to rotate; the friction piece is connected to the output shaft in a sleeving mode and used for generating friction torque for preventing the output shaft from rotating so that the lead screw can be self-locked. The friction piece is connected to the output shaft of the driving motor in a sleeving mode, the friction torque is applied to the output shaft through the friction piece, and the output shaft is kept static in the power-off state of the driving motor, so that the lead screw coaxial with the lead screw is kept static, and self-locking of the lead screw is achieved.

Description

Technical Field

[0001] The present application relates to the field of three-dimensional printers, and in particular to a three-dimensional printer. Background Art

[0002] 3D printer (also known as three-dimensional printer or stereo printer) is a kind of rapid prototyping process equipment. The 3D printing technology currently available for 3D printers is fused deposition modeling (FDM). FDM is a technology that uses materials such as powdered metal or plastic based on digital models to construct three-dimensional objects by printing layer by layer.

[0003] Currently in 3D printers, the Z-axis assembly often uses a trapezoidal lead screw. The helix angle of the trapezoidal lead screw is smaller than the friction angle, so it can achieve self-locking when the power is off. However, if the Z-axis assembly uses a lead screw with a larger lead so that the helix angle is greater than the friction angle, the lead screw cannot self-lock after power is off, which can easily lead to printing failure. Utility Model Content

[0004] The present application provides a three-dimensional printer that overcomes the above problems or at least partially solves the above problems. The printer has a Z-axis self-locking structure.

[0005] In a first aspect, an embodiment of the present application provides a three-dimensional printer, comprising:

[0006] Printing platform;

[0007] Print head;

[0008] A motion mechanism, used to drive at least one of the print head and the printing platform, so that the print head is displaced relative to the printing platform;

[0009] The motion mechanism includes a Z-axis motion mechanism, and the Z-axis motion mechanism includes:

[0010] Screw rod;

[0011] A driving motor, coaxially connected to the output shaft of the driving motor, and used to drive the screw to rotate;

[0012] The friction member is sleeved on the output shaft and is used to generate a friction torque to prevent the output shaft from rotating, so that the screw rod is self-locking.

[0013] In a possible specific embodiment, the drive motor has a cogging torque in a power-off state.

[0014] In a possible implementation manner, the Z-axis motion mechanism further includes: a coupling, through which the output shaft and the lead screw are connected;

[0015] The friction member comprises an elastic component, one end of the elastic component abuts against the drive motor, and the other end abuts against the coupling, and the distance between the coupling and the drive motor causes the elastic component to be in a compressed state.

[0016] In a possible implementation, the elastic component includes:

[0017] The first gasket is sleeved on the output shaft, one side of the first gasket abuts against the driving motor, and the other side of the first gasket abuts against the elastic element in the elastic component.

[0018] In a possible implementation, the elastic component includes:

[0019] The second gasket is sleeved on the output shaft, one side of the second gasket abuts against the coupling, and the other side of the second gasket abuts against the elastic element in the elastic component.

[0020] In a possible implementation, the elastic component includes: an elastic element, which is sleeved on the output shaft and can be compressed in the axial direction of the output shaft to generate elastic force in the axial direction.

[0021] In a possible implementation manner, the friction member includes: a shaft seal or an oil seal, which is used to be sleeved on and abut against the output shaft, and is used to generate friction force between the output shaft and the output shaft.

[0022] In the embodiment of the present application, a friction member is sleeved on the output shaft of the driving motor, and a friction torque is applied to the output shaft by the friction member. When the driving motor is powered off, the output shaft is kept stationary, so that the screw rod coaxial with the screw rod is also kept stationary, thereby realizing self-locking of the screw rod. Since the friction member is directly sleeved on the output shaft, the axial space of the output shaft is utilized, and the self-locking of the screw rod can be realized by generating a friction torque, and the structure is simple; the self-locking of the screw rod is realized without increasing the space occupied by the original structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 A schematic diagram of the structure of a three-dimensional printer according to an embodiment of the present application;

[0024] Figure 2 A schematic diagram of the structure of a Z-axis motion mechanism in an embodiment of the present application;

[0025] Figure 3 This is a schematic diagram of the structure of another Z-axis motion mechanism according to an embodiment of the present application;

[0026] Description of reference numerals:

[0027] 1-print head, 2-motion mechanism, 21-Z-axis motion mechanism, 3-printing platform, 31-printing panel, 32-heat bed, 33-base;

[0028] 100-screw, 200-drive motor, 300-friction part, 310-elastic element, 320-first gasket, 330-second gasket, 340-shaft seal, 400-coupling. DETAILED DESCRIPTION

[0029] The technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application.

[0030] The Z-axis direction described in the embodiment of the present invention refers to the direction perpendicular to the XOY plane with the printing platform as the XOY plane as the Z-axis direction. The Z-axis is also a coordinate axis perpendicular to the XOY plane.

[0031] In the present application, unless otherwise clearly specified and limited, the terms "fixed", "set", "installed", and "connected" may mean that one element is directly on another element or there may be an element in the middle, "fixed" may be understood as "fixed connection", and "set", "installed", and "connected" may all be understood as a type of connection. At the same time, the connection may include a mechanical connection or a structural connection, and may also be understood as an electrical connection, a thermal connection, or a communication connection. For mechanical or structural connections, the connection includes a detachable connection and a non-detachable connection. For example, a fixed connection may include a detachable fixed connection, a non-detachable fixed connection, or an integrally formed connection. A rotating connection may include a detachable rotating connection and a non-detachable rotating connection. A sliding connection may include a detachable sliding connection and a non-detachable sliding connection. The connection may also be a direct connection or an indirect connection through a component. For example, for a detachable fixed connection, it means that in the installed state, the positional relationship between at least two connected objects can be fixed; similar examples include a rotating connection, a sliding connection, and the like.

[0032] The implementation of the technical solution of the present application is further described in detail below in conjunction with the accompanying drawings.

[0033] Reference Figure 1 , shows a structural diagram of a 3D printer according to an embodiment of the utility model. The 3D printer comprises: a printing platform 3, a motion mechanism 2 and a print head 1, wherein the print head 1 is arranged above the printing platform 3, and the motion mechanism 20 is used to drive at least one of the print head 1 and the printing platform 3, so that a relative displacement occurs between the print head 1 and the printing platform 3.

[0034] The print head 1 is arranged above the printing platform 3, and is used to extrude the printing material that is heated and melted into a molten state; the feeding device is connected to the feeding end of the print head 1 of the 3D printer, and provides a material line for the print head 1 of the 3D printer. The motion mechanism 2 drives at least one of the print head 1 and the printing platform 3 to move, so that a relative displacement is generated between the print head 1 and the printing platform 3, so as to print or construct a three-dimensional model.

[0035] The print head 1 may include a feeding assembly, a 3D printing nozzle, and an extrusion assembly disposed between the feeding assembly and the 3D printing nozzle. During the feeding process of the feeding device, the printing material passes through the feeding assembly and then enters the extrusion assembly, and the extrusion assembly supplies the printing material to the 3D printing nozzle; during the material withdrawal process of the feeding device, the 3D printer cuts off the printing material in the print head, and the extrusion assembly withdraws the printing material to the feeding device, and the loading and unloading assemblies in the feeding device rewind the withdrawn printing material to the material tray.

[0036] Optionally, the 3D printer may, for example, cut off the printing material between the extrusion component and the 3D printing nozzle or may cut off the printing material in the extrusion component, etc. The present application does not limit the position where the 3D printer cuts off the printing material.

[0037] Exemplarily, the 3D printer further includes a printing panel 31, a heat bed 32 and a base 33. The heat bed 32 is disposed on the side of the base 33 facing the 3D printing nozzle, and the heat bed 32 has a heating function. The printing panel 31 is disposed on the side of the heat bed 32 facing the 3D printing nozzle 11, and the heat of the heat bed 32 can be transferred to the printing panel 31, and the nozzle can extrude the molten printing material onto the printing panel 31.

[0038] In a specific implementation, the 3D printer can adjust the temperature of the heating block and the hot bed 32 corresponding to the 3D printing nozzle, adjust the temperature of the heating block to heat the printing material to a molten state, and adjust the temperature of the hot bed 32 to adhere the printing material extruded by the nozzle to the printing panel 31. Among them, the print head 1 is slidably connected to the first guide rail, and the print head 1 can move along the length direction of the first guide rail, that is, the displacement of the print head 1 relative to the printing panel 31 along the length direction of the first guide rail is realized, and the hot bed 32 is slidably connected to the second guide rail, and the hot bed 32 moves along the length direction of the second guide rail, that is, the displacement of the print head 1 relative to the printing panel 31 along the length direction of the second guide rail is realized, and the length direction of the second guide rail is perpendicular to the length direction of the first guide rail. In addition, the first guide rail is located on the X-axis motion mechanism, and the X-axis motion mechanism is slidably connected to the third guide rail. The 3D printer can realize the displacement of the print head 1 relative to the printing panel 31 in the direction perpendicular to the length of the second guide rail and the direction perpendicular to the length of the first guide rail by moving the X-axis motion mechanism along the third guide rail. That is, the 3D printer can realize relative displacement between the print head 1 and the print panel 31 in three mutually perpendicular directions, thereby printing a 3D object. The second guide rail is located on the Y-axis motion mechanism, and the third guide rail is located on the Z-axis motion mechanism, which is usually called a column.

[0039] The motion mechanism 2 may include a Z-axis motion mechanism. The Z-axis motion mechanism drives at least one of the printing platforms 3 of the print head 1 to move on the Z-axis, generating a displacement in the Z-axis direction, thereby achieving model printing in the Z-axis direction.

[0040] You can refer to Figure 2 , shows a schematic structural diagram of a Z-axis motion mechanism according to an embodiment of the present application; the Z-axis motion mechanism includes a screw rod 100, a drive motor 200 and a friction member 300. It may further include a third guide rail, which may be parallel to the screw rod 100.

[0041] The screw rod 100 can be connected to the X-axis motion mechanism 1 or the printing platform through a slider (including a screw nut). When the screw rod 100 rotates, the slider is driven to move along the Z axis. The output shaft of the drive motor 200 is coaxially connected to the screw rod 100. When the drive motor 200 is powered on, the current will pass through the driven coil to generate a magnetic field inside the drive motor 200. The magnet of the drive motor 200 generates a fixed magnetic field. According to the effect of the Lorentz force, this fixed magnetic field interacts with the magnetic field generated by the motor coil, generates a driving torque, and the motor starts to rotate, and outputs a driving torque through the output shaft of the drive motor 200, and drives the screw rod 100 to rotate through the driving torque. In actual use, the lead of the screw rod 100 is not limited, and the embodiment of the present application can realize the self-locking of the screw rod whose lead is not enough for self-locking. In an example of the present application, the screw rod 100 can be a lead 8 screw rod 100.

[0042] The friction member 300 is sleeved on the output shaft of the drive motor 200. When the drive motor 200 is suddenly powered off, the drive motor 200 instantly loses torque, and under the gravity of the X-axis motion mechanism (including the print head) or the printing platform, the lead screw is driven to rotate. At this time, the friction torque of the friction member 300 that prevents the output shaft from rotating prevents the output shaft of the drive motor 200 from rotating. Correspondingly, the lead screw coaxial with the output shaft of the drive motor 200 is indirectly affected by the friction torque and cannot rotate, thereby realizing the self-locking of the lead screw 100. The embodiment of the present application realizes the Z-axis self-locking structure through the friction member 300.

[0043] Those skilled in the art understand that a 3D printer with a single filament often has poor self-locking performance. Therefore, in one example of the present application, the 3D printer in the embodiment of the present application is a 3D printer with a single filament.

[0044] In an optional implementation of the application, the Z-axis motion mechanism further includes: a coupling 400, through which the output shaft and the screw rod 100 are connected;

[0045] One end of the coupling 400 is connected to the screw 100, and the other end of the coupling 400 is connected to the output shaft, and the torque output by the output shaft can be transmitted to the screw 100 through the coupling 400, thereby driving the screw 100 to rotate. In the embodiment of the present application, the friction member 300 includes an elastic component, one end of the elastic component is against the drive motor 200, and the other end is against the coupling 400, and the distance between the coupling 400 and the drive motor 200 makes the elastic component in a compressed state.

[0046] An elastic component can be provided between the coupling 400 and the drive motor 200. When the elastic component is installed, an axial preload force is applied to the elastic component toward the drive motor 200, and the elastic element 310 is compressed by locking the output shaft through the coupling 400; the elastic element 310 is in a compressed state. When the drive motor 200 is powered off, the drive motor 200 loses its holding torque, and under the action of gravity, a driving torque is generated to drive the screw rod to rotate in the opposite direction. When the driving torque caused by its own weight is less than or equal to the friction torque generated by the elastic force brought by the elastic element 310, the screw rod 100 is stationary, and the components connected to the screw rod 100 will not move downward, thereby realizing the self-locking function of the screw rod 100.

[0047] In an optional implementation of the application, the elastic component includes: an elastic element 310, which is sleeved on the output shaft and can be compressed in the axial direction of the output shaft to generate elastic force in the axial direction.

[0048] The elastic element 310 can be a corrugated gasket, an O-ring, a flat gasket or the like, and the elastic element 310 is made of fluororubber, PU (polyurethane), or 65Mn (spring steel). The elastic force of the elastic element 310 forms a friction torque to prevent the screw rod 100 from rotating, thereby achieving self-locking of the screw rod 100.

[0049] In an optional implementation of the application, the elastic component includes:

[0050] The first gasket 320 is sleeved on the output shaft, one side of the first gasket 320 abuts against the driving motor 200 , and the other side of the first gasket 320 abuts against the elastic element 310 in the elastic assembly.

[0051] Correspondingly, the elastic component includes:

[0052] The second gasket 330 is sleeved on the output shaft, one side of the second gasket 330 abuts against the coupling 400 , and the other side of the second gasket 330 abuts against the elastic element 310 in the elastic assembly.

[0053] In the embodiment of the present application, the first gasket 320 and / or the second gasket 330 can be sleeved on the output shaft. The first gasket 320 and the second gasket 330 can be gaskets of the same specifications, sizes, and materials, or gaskets of different specifications, sizes, and materials; the embodiment of the present application does not specifically limit this.

[0054] The first gasket 320 and the second gasket 330 can be made of materials such as 65Mn and stainless steel to ensure their service life.

[0055] The first gasket 320 is located between the elastic element 310 and the drive motor 200. The second gasket 330 is located between the elastic element 310 and the coupling 400. The first gasket 320 and the second gasket 330 increase the contact area between the elastic component and the drive motor 200 or the coupling 400, increase the reliability of the connection, and provide sufficient friction area, so that appropriate friction torque can be generated to achieve self-locking of the screw rod 100.

[0056] In addition, refer to Figure 3 , shows a schematic diagram of the structure of another Z-axis motion mechanism according to an embodiment of the present application. The lead screw 100 and the drive motor 200 can refer to the above embodiment.

[0057] The friction member 300 in the embodiment of the present invention may include: a shaft seal 340 or an oil seal. The shaft seal 340 or the oil seal may be sleeved on the output shaft of the drive motor 200. The shaft seal 340 or the oil seal may be made of fluororubber, PU, ​​ordinary rubber, etc. This embodiment of the present application does not specifically limit this.

[0058] When the shaft seal 340 or the oil seal sleeve is arranged on the output shaft, it abuts against the output shaft so that when the output shaft rotates, the friction between the shaft seal 340 and the motor shaft provides a holding torque, and the output shaft and the screw rod 100 are kept stationary by the holding torque, thereby achieving self-locking of the screw rod 100.

[0059] Therefore, when the power is suddenly cut off, the drive motor 200 instantly loses the torque to maintain rotation. Under the action of gravity of the X-axis motion mechanism or the printing platform, a driving torque is generated to drive the screw rod to rotate in the opposite direction. When the driving torque is less than or equal to the holding torque brought by the shaft seal 340, the X-axis motion mechanism (including the print head) or the printing platform will not move downward, thereby realizing the self-locking function of the screw rod 100.

[0060] Due to the friction of the shaft seal 340 or the oil seal, the coupling 400 and the drive motor 200 only need to be locked with each other, without any axial position requirements, and when the shaft seal 340 or the oil seal is used, the axial dimension of the structure is smaller, which can make the structure more compact.

[0061] In an optional implementation of the application, the drive motor 200 has a cogging torque in the power-off state. The cogging torque is converted into a friction torque that prevents the output shaft from rotating, thereby achieving self-locking of the screw rod 100.

[0062] In the embodiment of the present application, the friction member 300 is sleeved on the output shaft of the driving motor 200, and the friction member 300 is used to apply a friction torque to the output shaft. When the driving motor 200 is powered off, the output shaft is kept stationary, so that the screw rod 100 coaxial with the screw rod 100 is also kept stationary, thereby achieving self-locking of the screw rod 100. Since the friction member 300 is directly sleeved on the output shaft, the structure is simple; the self-locking of the screw rod 100 is achieved without increasing the space occupied by the original structure.

[0063] The terms "first", "second", etc. are used for descriptive purposes only and should not be understood as suggesting or implying relative importance or implicitly indicating the number or order of the indicated technical features. Thus, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present application, the meaning of "multiple" is two or more, unless otherwise clearly and specifically defined. In addition, the terms "including", "comprising" and "having" and any of their variations are intended to cover non-exclusive inclusions. As used in the present application, the term "and / or" includes any and all combinations of one or more of the associated listed items, and the phrase "at least one of A and B" refers to only A, only B, or both A and B. It should be understood that in this specification, the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "height", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships or dimensions that are based on the orientations or positional relationships or dimensions shown in the accompanying drawings, and these terms are used only for the convenience of description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the scope of protection of the present disclosure.

[0064] The above disclosure is only a preferred embodiment of the present invention, and certainly cannot be used to limit the scope of rights of the present invention. Therefore, equivalent changes made according to the claims of the present invention are still within the scope covered by the present invention.

Claims

1. A three-dimensional printer, characterized in that: include: Printing platform; Print head; A motion mechanism, used to drive at least one of the print head and the printing platform, so that the print head is displaced relative to the printing platform; The motion mechanism includes a Z-axis motion mechanism, and the Z-axis motion mechanism includes: Screw rod; A driving motor, coaxially connected to the output shaft of the driving motor, and used to drive the screw to rotate; The friction member is sleeved on the output shaft and is used to generate a friction torque to prevent the output shaft from rotating, so that the screw rod is self-locking.

2. The three-dimensional printer according to claim 1, characterized in that: The drive motor has a cogging torque in a de-energized state.

3. The three-dimensional printer according to claim 1, characterized in that: The Z-axis motion mechanism further comprises: a coupling, through which the output shaft and the lead screw are connected; The friction member comprises an elastic component, one end of the elastic component abuts against the drive motor, and the other end abuts against the coupling, and the distance between the coupling and the drive motor causes the elastic component to be in a compressed state.

4. The three-dimensional printer according to claim 3, characterized in that: The elastic component comprises: The first gasket is sleeved on the output shaft, one side of the first gasket abuts against the driving motor, and the other side of the first gasket abuts against the elastic element in the elastic component.

5. The three-dimensional printer according to claim 3 or 4, characterized in that: The elastic component comprises: The second gasket is sleeved on the output shaft, one side of the second gasket abuts against the coupling, and the other side of the second gasket abuts against the elastic element in the elastic component.

6. The three-dimensional printer according to claim 3 or 4, characterized in that: The elastic component comprises: an elastic element, which is sleeved on the output shaft and can be compressed in the axial direction of the output shaft to generate elastic force in the axial direction.

7. The three-dimensional printer according to claim 1 or 2, characterized in that: The friction member includes: a shaft seal or an oil seal, which is used to be sleeved on and abut against the output shaft and to generate friction between the output shaft and the output shaft.

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