阅读说明：本技术 七轴并联随形曲面熔融沉积增材制造装置 (Seven-shaft parallel shape-following curved surface fused deposition additive manufacturing device ) 是由 李立鹏 崔滨 刘亚雄 李良刚 陈恒威 于 2019-10-31 设计创作，主要内容包括：一种七轴并联随形曲面熔融沉积增材制造装置,包括相互配合的上平台和下平台,上平台为非对称式五轴并联机器人,下平台为两轴并联结构动平台；在上动平台下面安装熔融头,塑料丝经由挤丝机送入熔融头,加工成型表面在下动平台上面；本发明实现随形曲面熔融沉积成型,具有结构紧凑简洁、控制灵活、刚度高、精度高、自由度大、成型范围大的优点。(A seven-axis parallel shape-following curved surface fused deposition additive manufacturing device comprises an upper platform and a lower platform which are matched with each other, wherein the upper platform is an asymmetric five-axis parallel robot, and the lower platform is a movable platform with a two-axis parallel structure; a melting head is arranged below the upper movable platform, plastic wires are fed into the melting head through a wire extruding machine, and the processing and forming surface is arranged above the lower movable platform; the invention realizes the conformal curved surface fused deposition molding and has the advantages of compact and simple structure, flexible control, high rigidity, high precision, large degree of freedom and large molding range.)

1. A seven-axis parallel shape-following curved surface fused deposition additive manufacturing device is characterized in that: the robot comprises an upper platform and a lower platform which are matched with each other, wherein the upper platform is an asymmetric five-axis parallel robot, and the lower platform is a movable platform with a two-axis parallel structure.

2. The seven-axis parallel conformal curved surface fused deposition additive manufacturing device according to claim 1, wherein: the upper platform comprises an upper fixed platform and an upper movable platform (12) connected with the upper fixed platform, the upper fixed platform comprises a truss (11), a first driving unit (1), a second driving unit (2), a third driving unit (3), a fourth driving unit (4) and a fifth driving unit (5) are fixed on the truss (11), the first driving unit (1), the second driving unit (2), the third driving unit (3), the fourth driving unit (4) and the fifth driving unit (5) are connected with the upper movable platform (12) through a first connecting rod (6), a second connecting rod (7), a third connecting rod (8), a fourth connecting rod (9) and a fifth connecting rod (10), the first driving unit (1) and the second driving unit (2) control the horizontal plane movement of the upper movable platform (12), and the third driving unit (3) and the fourth driving unit (4) control the horizontal plane rotation of the upper movable platform (12), the fifth driving unit (5) controls the upper movable platform (12) to move in the vertical direction; the space closed-loop structure comprises a first driving unit (1), a second driving unit (2), a third driving unit (3), a fourth driving unit (4), a fifth driving unit (5), a first connecting rod (6), a second connecting rod (7), a third connecting rod (8), a fourth connecting rod (9), a fifth connecting rod (10), a truss (11) and an upper moving platform (12).

3. The seven-axis parallel conformal curved surface fused deposition additive manufacturing device according to claim 1 or 2, wherein: the lower platform comprises a lower fixed platform and a lower movable platform (18) connected with the lower fixed platform, and the lower movable platform (18) is positioned below the upper movable platform (12); the lower fixed platform comprises a bottom plate (17), a sixth driving unit (13) and a seventh driving unit (14) are fixed on the bottom plate (17), the sixth driving unit (13) and the seventh driving unit (14) are connected with the lower surface of the lower movable platform (18) through a sixth connecting rod (15) and a seventh connecting rod (16), and the center of the lower movable platform (18) is connected with the bottom plate (17) through a universal joint (19); the sixth driving unit (13) controls the lower moving platform (18) to rotate along one axis of the horizontal plane, and the seventh driving unit (14) controls the lower moving platform (18) to rotate along the other axis of the horizontal plane; the bottom plate (17), the sixth driving unit (13), the seventh driving unit (14), the sixth connecting rod (15), the seventh connecting rod (16) and the downward moving platform (18) form a space closed loop structure.

Technical Field

The invention belongs to the technical field of fused deposition forming in three-dimensional additive manufacturing, and particularly relates to a seven-axis parallel conformal curved surface fused deposition additive manufacturing device.

Background

The fused deposition modeling technology is one of additive manufacturing technologies, has the advantages of simple use, low cost, no pollution and the like, and is widely applied to industrial-grade and consumer-grade markets. The mainstream fused deposition modeling additive manufacturing device at present mainly comprises: an XYZ type 3D printer adopting a rectangular coordinate robot, an Delta printer adopting a parallel robot and a CoreXY type 3D printer adopting a series-parallel composite structure. The motion mechanisms of the additive manufacturing devices have three degrees of freedom, can move horizontally and vertically, and adopt a planar stacking forming technology to carry out fused deposition forming. Due to the limitation of the planar lamination molding technology, the existing fused deposition modeling additive manufacturing device has three problems: the adhesive force between layers is smaller than that in the layers, although the improvement can be realized by adopting a cross filling line mode, the problem of poor shear resistance in the laminating direction cannot be fundamentally solved; for curved surface parts, the plane stacking can cause the curved surface outline to generate a step effect, and the step effect can be reduced but cannot be completely eliminated by the current self-adaptive slicing method; thirdly, for parts with internal spaces and cantilever structures, in order to prevent the fuse from collapsing, the internal lightweight structure and the external support must be tightly filled, and the external support needs to be removed finally, so that the subsequent treatment process is increased, and the waste of materials and the reduction of the efficiency of the finished part are caused. In summary, the application of fused deposition modeling of layers has been limited by the mainstream planar lamination modeling techniques.

The conformal curved surface forming refers to an additive manufacturing technology for performing discretization stacking according to curved surfaces on the surfaces of parts, wherein the layer cutting mode is a three-dimensional curved surface layer cutting method, and the filling mode is a three-dimensional curve filling strategy. Firstly, because the forming and stacking direction of the conformal curved surface is not unique, the problem of poor shearing resistance in the stacking direction can be solved; secondly, because the spinning path can be planned according to the curved surface change of the surface of the part, the step effect of the curved surface profile can be eliminated; and thirdly, the number of layers can be reduced by the curved surface layering mode, and the printing time is saved. In order to realize the forming of the conformal curved surface, a forming device with more than three shafts needs to be established.

The existing multi-axis fused deposition modeling device generally imitates a five-axis numerical control machine tool, and a rotating structure is connected in series on an original three-degree-of-freedom movement mechanism to form a rotatable fusion head or a rotatable swing platform. However, the serial structure not only generates accumulated errors, but also the lower structure loads the weight of the upper structure, thereby causing the problems of poor rigidity and high cost for improving precision. The existing multi-axis parallel robot generally adopts a symmetrical structure, can realize multi-degree-of-freedom motion, but cannot rotate the tail end to any angle due to the interference influence between connecting rods, and the working range is limited to a certain extent.

Disclosure of Invention

In order to overcome the defects of the prior art, the invention aims to provide the seven-axis parallel shape-following curved surface fused deposition additive manufacturing device, which realizes the shape-following curved surface fused deposition molding and has the advantages of compact and simple structure, flexible control, high rigidity, high precision, large degree of freedom and large molding range.

In order to achieve the purpose, the invention adopts the technical scheme that:

a seven-axis parallel shape-following curved surface fused deposition additive manufacturing device comprises an upper platform and a lower platform which are matched with each other, wherein the upper platform is an asymmetric five-axis parallel robot, and the lower platform is a movable platform with a two-axis parallel structure.

The upper platform comprises an upper fixed platform and an upper movable platform 12 connected with the upper fixed platform, the upper fixed platform comprises a truss 11, a first driving unit 1, a second driving unit 2, a third driving unit 3, a fourth driving unit 4 and a fifth driving unit 5 are fixed on the truss 11, the first driving unit 1, the second driving unit 2, the third driving unit 3, the fourth driving unit 4 and the fifth driving unit 5 are connected with the upper movable platform 12 through a first connecting rod 6, a second connecting rod 7, a third connecting rod 8, a fourth connecting rod 9 and a fifth connecting rod 10, the first driving unit 1 and the second driving unit 2 control the horizontal plane motion of the upper movable platform 12, the third driving unit 3 and the fourth driving unit 4 control the plane rotation of the upper movable platform 12, and the fifth driving unit 5 controls the vertical direction motion of the upper movable platform 12; the first driving unit 1, the second driving unit 2, the third driving unit 3, the fourth driving unit 4, the fifth driving unit 5, the first connecting rod 6, the second connecting rod 7, the third connecting rod 8, the fourth connecting rod 9, the fifth connecting rod 10, the truss 11 and the upper movable platform 12 form a space closed loop structure.

The lower platform comprises a lower fixed platform and a lower movable platform 18 connected with the lower fixed platform, and the lower movable platform 18 is positioned below the upper movable platform 12; the lower fixed platform comprises a bottom plate 17, a sixth driving unit 13 and a seventh driving unit 14 are fixed on the bottom plate 17, the sixth driving unit 13 and the seventh driving unit 14 are connected with the lower part of a lower movable platform 18 through a sixth connecting rod 15 and a seventh connecting rod 16, and the center of the lower movable platform 18 is connected with the bottom plate 17 through a universal joint 19; the sixth driving unit 13 controls the lower movable platform 18 to rotate along one axis of the horizontal plane, and the seventh driving unit 14 controls the lower movable platform 18 to rotate along the other axis of the horizontal plane; the bottom plate 17, the sixth driving unit 13, the seventh driving unit 14, the sixth connecting rod 15, the seventh connecting rod 16 and the lower moving platform 18 form a space closed loop structure.

Compared with the prior art, the invention has the following beneficial effects:

the load of the upper structure is reduced, and the printing precision is improved. The invention adopts a structure that the first driving unit 1, the second driving unit 2, the third driving unit 3, the fourth driving unit 4 and the fifth driving unit 5 are connected with the upper movable platform 12 through the first connecting rod 6, the second connecting rod 7, the third connecting rod 8, the fourth connecting rod 9 and the fifth connecting rod 10, compared with the structure that the upper movable platform 12 is connected in series on the original three-degree-of-freedom motion mechanism, the invention lightens the load of the top layer truss structure, improves the precision of the printer and simultaneously reduces the cost of the printer.

The working range is enlarged, and the extrusion axis is ensured to be vertical to the printing surface. The mechanical properties of the part are greatly affected by the microscopic structure, especially in anisotropic structures such as FDM forming. In a general five-axis printer, the tail end cannot rotate to any angle due to interference between connecting rods, so that the working range is limited to a certain extent. The invention adopts the upper platform control of the first connecting rod 6, the second connecting rod 7, the third connecting rod 8, the fourth connecting rod 9 and the fifth connecting rod 10 which share five shafts and the lower platform control of the sixth connecting rod 15 and the seventh connecting rod 16 which share two shafts, so that the upper movable platform 12 and the lower movable platform 18 can simultaneously rotate for a certain angle, the vertical direction of a spray head and a printing surface is ensured in the printing process, and the printing working range is expanded.

Drawings

Fig. 1 is a schematic structural diagram of an embodiment of the present invention.

FIG. 2 is a schematic diagram of an upper platform according to an embodiment of the present invention.

FIG. 3 is a schematic diagram of a lower platform according to an embodiment of the invention.

Detailed Description

Reference will now be made in detail to embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like or similar reference numerals refer to the same or similar elements or elements having the same or similar function throughout. The embodiments described below with reference to the accompanying drawings are illustrative only for the purpose of explaining the present invention, and are not to be construed as limiting the present invention.

Referring to fig. 1, 2 and 3, a seven-axis parallel conformal curved surface fused deposition additive manufacturing device comprises an upper platform and a lower platform which are matched with each other;

the upper platform comprises an upper fixed platform and an upper movable platform 12 connected with the upper fixed platform, the upper fixed platform comprises a truss 11, a first driving unit 1, a second driving unit 2, a third driving unit 3, a fourth driving unit 4 and a fifth driving unit 5 are fixed on the truss 11, the first driving unit 1, the second driving unit 2, the third driving unit 3, the fourth driving unit 4 and the fifth driving unit 5 are connected with the upper movable platform 12 through a first connecting rod 6, a second connecting rod 7, a third connecting rod 8, a fourth connecting rod 9 and a fifth connecting rod 10, the first driving unit 1 and the second driving unit 2 control the horizontal plane motion of the upper movable platform 12, the third driving unit 3 and the fourth driving unit 4 control the plane rotation of the upper movable platform 12, and the fifth driving unit 5 controls the vertical direction motion of the upper movable platform 12; the first driving unit 1, the second driving unit 2, the third driving unit 3, the fourth driving unit 4, the fifth driving unit 5, the first connecting rod 6, the second connecting rod 7, the third connecting rod 8, the fourth connecting rod 9, the fifth connecting rod 10, the truss 11 and the upper movable platform 12 form a space closed loop structure to form an asymmetric five-axis parallel robot;

the lower platform comprises a lower fixed platform and a lower movable platform 18 connected with the lower fixed platform, and the lower movable platform 18 is positioned below the upper movable platform 12; the lower fixed platform comprises a bottom plate 17, a sixth driving unit 13 and a seventh driving unit 14 are fixed on the bottom plate 17, the sixth driving unit 13 and the seventh driving unit 14 are connected with the lower part of a lower movable platform 18 through a sixth connecting rod 15 and a seventh connecting rod 16, and the center of the lower movable platform 18 is connected with the bottom plate 17 through a universal joint 19; the sixth driving unit 13 controls the lower movable platform 18 to rotate along one axis of the horizontal plane, and the seventh driving unit 14 controls the lower movable platform 18 to rotate along the other axis of the horizontal plane; the bottom plate 17, the sixth driving unit 13, the seventh driving unit 14, the sixth connecting rod 15, the seventh connecting rod 16 and the lower moving platform 18 form a space closed loop structure to form a moving platform with a two-axis parallel structure.

The working principle of the invention is as follows:

a melting head is arranged below the upper movable platform 12, plastic wires are fed into the melting head through a wire extruding machine, and the processing and forming surface is arranged above the lower movable platform 18; when 3D printing work of parts is carried out, the computer program controls the upper movable platform 12 and the lower movable platform 18, the wire extruding machine and the melting head to drive the melting head to move on the lower movable platform 18 in a translation mode according to the layer cutting data of the current layer model, and the wire extruding machine sends plastic wires into the melting head to extrude and lay wires and adheres the plastic wires to the lower movable platform 18; meanwhile, the computer program controls the first driving unit 1, the second driving unit 2, the third driving unit 3, the fourth driving unit 4 and the fifth driving unit 5 to drive the first connecting rod 6, the second connecting rod 7, the third connecting rod 8, the fourth connecting rod 9 and the fifth connecting rod 10 so as to control the upper movable platform 12 to move according to the position and angle movement data; under the upper movable platform, in order to ensure that the lower movable platform forms a certain angle with the upper movable platform, the computer program controls the sixth connecting rod 15 and the seventh connecting rod 16 to drive the sixth connecting rod 15 and the seventh connecting rod 16 to move according to the angle motion data, and the fusion deposition of the seven parallel conformal curved surfaces is realized.

Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that changes, modifications, substitutions and alterations can be made in these embodiments without departing from the principles and spirit of the invention, the scope of which is defined in the claims and their equivalents.