Method for manufacturing a three-dimensional object and support structure generation methodTechnical Field
The invention belongs to the technical field of rapid prototyping, and particularly relates to a method for manufacturing a three-dimensional object and a support structure generation method.
Background
Rapid Prototyping (RP) is an advanced manufacturing technology with distinct features of digital manufacturing, high flexibility and adaptability, direct CAD model driving, rapidity, rich and diverse material types, etc., and the technology is to stack powder materials layer by layer and build and form a three-dimensional workpiece by melting layer by layer, and the technology can manufacture a plurality of three-dimensional workpieces with complex shapes which are difficult to finish by the traditional process. However, in a special workpiece structure, such as a metal overhanging structure, an overhang and a buckling deformation are generated during the process, which affect the shape accuracy and the dimension accuracy of the workpiece, and even cause a construction failure in a more serious case. In order to avoid the above problems, it is common to design an external support structure to ensure the stability of the construction process and remove the support structure by other specific processes after the construction of the workpiece is completed. The manufacture of the support structure, like the manufacture of the workpiece, is time, energy and raw material consuming, and therefore the support structure affects not only the cost of manufacturing the workpiece, but also the efficiency of manufacturing the workpiece if the support structure is complex and numerous.
In the prior art, the supporting structure is formed by a plurality of columnar supporting structure units which are arranged vertically and horizontally, and the strength of the supporting structure is adjusted by adjusting the distance between the supporting structure units and the tooth-shaped structure at the joint of the supporting structure and a workpiece. The support structure is large in size, so that large material waste is caused, and meanwhile, the manufacturing efficiency of workpieces is reduced.
Disclosure of Invention
In view of the above technical problems in the prior art, the present invention provides a method for manufacturing a three-dimensional object and a method for generating a support structure, which can reduce the powder material for generating the support, thereby reducing the waste of material and improving the efficiency of the manufacturing process of the three-dimensional object.
In order to solve the technical problems, the invention adopts the following technical scheme:
a support structure for use in the manufacture of a three-dimensional object, wherein the support structure is tree-shaped and comprises at least one tree-shaped support structure for each part.
Further preferably, the tree support structure comprises leaves, branches and trunks.
Further preferably, the number of the leaves is several, and the leaves are uniformly arranged on the lower surface of the area needing to be supported.
A method of generating a support structure for fabricating a three-dimensional object, the method comprising:
obtaining all areas needing to be supported according to the processing of the data information of the workpiece;
and respectively generating a tree-shaped support structure between the required support area and the support plate.
Further preferably, the obtaining all the areas needing to be supported according to the processing of the data information of the workpiece specifically includes:
processing the data information of the workpiece, and searching all areas needing to be supported;
integrating the areas to obtain all areas needing to be supported;
here, the integration refers to integrating regions having adjacent vertices or edges into one region.
Further preferably, the method further comprises:
judging whether a workpiece body exists between the area needing to be supported and the supporting plate;
and if the area exists, dividing the area needing to be supported into a first area and a second area, wherein the area in the area needing to be supported, which is vertically corresponding to the product body, is the first area, and the remaining area needing to be supported after the first area is removed is the second area.
Further preferably, the generating the tree-shaped support structure between the area needing to be supported and the support plate specifically includes:
vertically projecting an area needing to be supported onto a supporting plate to obtain a plane area;
dividing the plane area by a plurality of unit areas, wherein the boundaries of all the plane areas are positioned in the unit areas;
dividing the plane area into a plurality of area groups, wherein the area groups comprise a first central area group and a plurality of first non-central area groups positioned around the first central area group, and each area group comprises a plurality of unit areas;
respectively finding out a second central area group corresponding to a plurality of area groups in the plane area and a plurality of second non-central area groups positioned around the second central area group on the lower surface of the area needing to be supported;
and generating the tree-shaped support structure downwards from a second central area group of the lower surface of the area needing to be supported and a plurality of second non-central area groups.
Further preferably, the generating the tree-shaped support structure downward from the second central area group and the plurality of second non-central area groups of the lower surface of the area to be supported specifically includes:
and (3) generating a trunk: a plurality of unit areas included in the second central area group are used as bottom surfaces and respectively vertically extend downwards until the supporting plates form a plurality of first columnar bodies;
and (3) leaf generation: each second non-central area group extends downwards to form an oblique cone;
and (3) generation of branches: each oblique cone is provided with a cone top, the cone top is used as a bottom surface, the oblique cone extends downwards in a direction forming a first inclination angle with the base plate to form an oblique cylinder, and the oblique cylinder is stopped to the position where the oblique cone intersects with the trunk.
Further preferably, before each second non-central area group respectively extends downwards to form a taper, the method further comprises:
and taking a plurality of unit areas included in each second non-central area group as bottom surfaces, and respectively extending downwards to form a plurality of second cylindrical bodies, wherein the height of each second cylindrical body is H.
Further preferably, the generating the leaves specifically includes:
selecting the unit area closest to the central area group from the second non-central area group and recording the unit area as a cone top area;
the conical top area is taken as the bottom surface and vertically extends downwards;
the other unit areas of the second non-central area group respectively extend downwards in a direction forming a second inclination angle with the substrate, so that the other unit areas are converged to the same section of the cone top area to form an inclined cone.
A method for fabricating a three-dimensional object, the method comprising:
generating a tree-shaped support structure according to the generation method;
combining the tree-shaped support structure and the three-dimensional object into a workpiece to be manufactured;
forming the workpiece to be manufactured by hardening the material layer by layer at the corresponding position;
and removing the tree-shaped support structure from the prepared workpiece to obtain the three-dimensional object.
The supporting structure for manufacturing the three-dimensional object is in the shape of the tree, and each part comprises at least one tree-shaped supporting structure, so that the tree-shaped supporting structure can greatly reduce materials for generating the supporting structure on the premise of supporting the parts and ensuring that the parts are not deformed, thereby reducing the waste of the materials, and the whole manufacturing process efficiency of the three-dimensional object is greatly improved due to the small building volume of the tree-shaped supporting structure.
The invention relates to a method for generating a support structure for manufacturing a three-dimensional object, comprising the following steps: obtaining all areas needing to be supported according to the processing of the data information of the workpiece; the tree-shaped supporting structures are respectively generated between the area needing to be supported and the supporting plate, so that the tree-shaped supporting structures can greatly reduce materials for generating the supporting structures on the premise of supporting the workpiece and ensuring that the workpiece is not deformed, thereby reducing the waste of the materials, and the required building volume of the tree-shaped supporting structures is small, thereby greatly improving the whole manufacturing process efficiency of the three-dimensional object.
The method for manufacturing the three-dimensional object comprises the step of generating the tree-shaped support structure by adopting the method, so that the tree-shaped support structure can greatly reduce materials for generating the support structure on the premise of supporting a workpiece and ensuring that the workpiece is not deformed, thereby reducing the waste of the materials, and greatly improving the whole manufacturing process efficiency of the three-dimensional object due to the small building volume required by the tree-shaped support structure.
Drawings
FIG. 1 is a schematic structural view of a support structure for fabricating a three-dimensional object according to the present invention;
FIG. 2 is a schematic view of a leaf structure according to an embodiment of the present invention;
FIG. 3 is a schematic representation of the operation of one embodiment of the support structure for fabricating three-dimensional objects of the present invention;
FIG. 4 is a schematic representation of the operation of another embodiment of the support structure for fabricating three-dimensional objects of the present invention;
FIG. 5 is a flowchart of a method according to an embodiment of the present invention for providing a method for generating a support structure for fabricating a three-dimensional object;
FIG. 6 is a method flow diagram of another embodiment provided by the method for generating a support structure for fabricating a three-dimensional object of the present invention;
FIG. 7 is a flowchart illustrating a method for generating a tree support structure according to an embodiment of the present invention;
FIG. 8 is a flowchart of a method of an embodiment of the present invention for fabricating a three-dimensional object.
Detailed Description
In order to make the technical solution of the present invention better understood and realized by those skilled in the art, the following detailed description is given with reference to the accompanying drawings and specific embodiments.
As shown in fig. 1-4, a support structure for manufacturing three-dimensional objects, wherein the support structure is shaped as a tree and comprises, for each object 4, at least one tree-shaped support structure comprising leaves 1, limbs 2 and trunks 3. It will be appreciated that since the article 4 of figure 3 has only one region to be supported, only one tree-shaped support structure is shown, but if there are multiple regions of the article 4 to be supported, then there will be multiple tree-shaped support structures involved.
As shown in fig. 1, 3 and 4, the number of the leaves 1 is several, and the leaves are uniformly arranged on the lower surface of the area to be supported. In a specific embodiment, the distance between adjacent leaves 1 can be set by the designer according to the requirements, for example, for some areas where reinforcing support is required (the contour edge of the object 4 or the area close to the starting position of the powder laying device), the leaves 1 in these areas can be arranged compactly, that is, the distance between adjacent leaves 1 is small, and for some areas where reinforcing support is not required, the distance between adjacent leaves 1 can be made appropriately large.
As shown in fig. 5, a method of generating a support structure for fabricating a three-dimensional object, the method comprising the steps of:
step 31, obtaining all areas needing to be supported according to the processing of the data information of the workpiece;
in this step, all regions to be supported may be obtained by processing data information of the workpiece, and in a specific implementation, some regions may have adjacent vertices or adjacent edges, and in this case, in order to simplify the process and improve the work efficiency, it is preferable that the regions having the adjacent vertices or the adjacent edges are integrated into one region, so that all the regions to be supported may be obtained by integration.
In a specific implementation, with reference to fig. 4, the method further includes:
judging whether a workpiece body exists between the area needing to be supported and the supporting plate;
and if the area exists, dividing the area needing to be supported into a first area and a second area, wherein the area in the area needing to be supported, which is vertically corresponding to the product body, is the first area, and the remaining area needing to be supported after the first area is removed is the second area.
Preferably, after the partial areas are integrated, all areas needing to be supported obtained after the integration can be screened, wherein screening conditions are set by a designer according to needs, for example, the area is too close to the support plate and is not suitable for forming a tree-shaped support structure, and for example, the area is too small and is not suitable for forming the tree-shaped support structure, so that after the screening, the areas meeting the conditions are used for generating the tree-shaped support structure by adopting the following steps, and the areas not meeting the conditions are supported by adopting the existing support structure (formed by a plurality of columnar support structure units arranged vertically and horizontally).
And 32, respectively generating a tree-shaped support structure between the area needing to be supported and the support plate.
In the step, the support plate is mainly used for supporting the tree-shaped support structure, and it should be noted that, in all the areas to be supported obtained in the step 31, when a certain area to be supported belongs to the first area (where a product body exists), the support plate is a product body existing in the first area, that is, the tree-shaped support structure is produced on the product body; and all the areas needing to be supported except the first area, wherein the supporting plate is a substrate for bearing the workpiece.
In this step, a tree-shaped support structure is generated for each area to be supported, in a specific implementation, the generation of the tree-shaped support structure may be implemented in different manners, and fig. 6 below shows a manner of generating the tree-shaped support structure, but the present invention is not limited to this implementation manner, and in addition, a tree-shaped support structure is preferably generated for each area to be supported.
Fig. 6 is a flowchart of a method of another embodiment of the present invention for generating a support structure for fabricating a three-dimensional object, as shown in fig. 6, the method for generating a support structure for fabricating a three-dimensional object includes the following steps:
step 41, processing data information of the workpiece, and searching all areas needing to be supported;
step 42, vertically projecting the area needing to be supported onto the supporting plate to obtain a plane area;
step 43, dividing the plane areas by using a plurality of unit areas, wherein the boundaries of all the plane areas are located in the unit areas;
step 44, dividing the plane area into a plurality of area groups, wherein the area groups comprise a first central area group and a plurality of first non-central area groups positioned around the first central area group, and each area group comprises a plurality of unit areas;
step 45, respectively finding out a second central area group corresponding to a plurality of area groups in the plane area and a plurality of second non-central area groups positioned around the second central area group on the lower surface of the area needing to be supported;
in the step, a second central area group and a plurality of second non-central area groups located around the second central area group, which are respectively corresponding to the plurality of area groups in the plane area, are found out in the following way:
the plurality of unit areas included in each area group in the plane area are taken as bottom surfaces and respectively vertically extend upwards until the bottom surfaces are contacted with the areas needing to be supported, and the contact surfaces are the area groups corresponding to the area groups in the plane area in the areas needing to be supported, for example, a first central area group corresponds to a second central area group, and a plurality of first non-central area groups correspond to a plurality of second non-central area groups respectively.
And 46, generating a tree-shaped support structure downwards from the second central area group and the plurality of second non-central area groups of the lower surface of the area needing to be supported.
It is understood that this step can be implemented by different methods, and a specific method for implementing this step is given in fig. 7 below, but of course, the present invention is not limited to be implemented by this method, and as shown in fig. 7, the generating the tree-shaped support structure downward from the second central area group and the second non-central area groups of the lower surface of the area to be supported specifically includes:
step 451, generating a backbone;
in the step, a plurality of unit areas included in the second central area group are taken as bottom surfaces and respectively vertically extend downwards until a support plate forms a plurality of first columnar bodies, and the formed plurality of first columnar bodies are generated trunks;
step 452, generating leaves;
in the step, each second non-central area group respectively extends downwards to form an oblique cone, and the oblique cone is a generated leaf;
step 453, generating branches;
in the step, each oblique cone body is provided with a cone top, extends downwards in a direction forming a first inclination angle with the base plate to form an oblique cylinder body, and is stopped to the intersection position with the main stem, and the oblique cylinder body is a generated branch and is positioned between the leaves and the main stem. In specific implementation, the specific value of the first inclination angle can be comprehensively determined by a designer according to the distance between the required support area and the support plate, the area of the unit area group and the like, and preferably, the first inclination angle is 0-45 degrees.
Preferably, before forming a beveled cone at step 452, further comprising:
and taking a plurality of unit areas included in each second non-central area group as bottom surfaces, and respectively extending downwards to form a plurality of second cylindrical bodies, wherein the height of each second cylindrical body is H, the H is greater than 0, and specific parameter values can be comprehensively determined according to the distance between the required supporting area and the supporting plate, the shape of the required supporting area, materials and the like. It should be noted that the second cylindrical bodies and the oblique cone together form a leaf.
Fig. 2 is a schematic view of a leaf structure according to an embodiment of the present invention, and referring to fig. 2, the step 452 may specifically include the following steps:
selecting the unit area closest to the central area group from the second non-central area group and recording the unit area as a cone top area;
the conical top area is taken as the bottom surface and vertically extends downwards;
the other unit areas of the second non-central area group respectively extend downwards in a direction forming a second inclination angle with the substrate, so that the other unit areas are converged to the same section of the cone top area to form an inclined cone.
The unit region closest to the central region group means that the unit region is closest to the central position of the central region group.
In a specific implementation, a specific value of the second inclination angle may be determined by a designer according to a distance between a required support region and the support plate, an area of the unit region group, and the like, preferably, the second inclination angle is 0 to 45 degrees, and it should be noted herein that, for different unit regions in the remaining unit regions of the second non-central region group, corresponding second inclination angles may be different, and the specific value may be determined by the designer according to the distance between the required support region and the support plate, the area of the unit region group, and the like.
In one embodiment, the distance between adjacent leaves may be set by the designer as desired, for example, in areas where reinforcing support is required (the contour edge of the part or the area near the starting point of the breading unit), the leaves in these areas may be arranged compactly, i.e., so that the distance between adjacent leaves is small, while in areas where reinforcing support is not required, the distance between adjacent leaves is suitably large.
In a specific implementation, the unit areas may be regular triangles, squares, or regular hexagons, and of course, the unit areas may also have other shapes, and it should be noted herein that, in the whole tree-shaped support structure, the unit areas in each area group have the same shape, and the unit areas in different area groups may have different shapes, for example, the unit areas in the area a group are all squares, and the unit areas in the area B group are all regular hexagons. Of course, it is preferable that all the area groups use the same shape of the unit area. In addition, different zone groups may include different numbers of unit zones throughout the tree support structure. In a specific embodiment, the side length of the unit area is 0.1 mm-10 mm. It should be noted that, when the unit areas in the second central area group and the second non-central area group are used as bottom surfaces and extend downwards to form leaves and trunks, each unit area can be extended to form a solid body or a hollow body, and of course, the hollow body is preferably formed to reduce the waste of materials and the construction volume and facilitate the removal of supports. Similarly, when the conical top is used as the bottom surface and extends downwards in the direction of a first inclination angle with the base plate to form an inclined column body, and the inclined column body is cut off to the intersection with the trunk, the inclined column body can be a solid body or a hollow body when the inclined column body is a generated branch, and the inclined column body is preferably a hollow body so as to reduce the waste of materials, build the volume and conveniently remove the support.
As shown in fig. 8, the method for manufacturing a three-dimensional object includes the steps of:
step 61, generating a tree-shaped support structure according to the generation method;
step 62, combining the tree-shaped support structure and the three-dimensional object into a workpiece to be manufactured;
step 63, forming the workpiece to be manufactured by hardening the material layer by layer at the corresponding position;
this step may be performed by using the existing selective laser melting technique or other rapid prototyping technique to manufacture the workpiece to be manufactured, and the specific process thereof will not be described in detail herein. It is understood that the material is a liquid material, a powder material, or the like.
And step 64, removing the tree-shaped support structure from the manufactured workpiece to obtain the three-dimensional object.
The above embodiments are merely preferred embodiments of the present invention, and the protection scope of the present invention is not limited to the above embodiments, and any technical solutions belonging to the idea of the present invention should fall within the protection scope of the present invention. It should be noted that several modifications and variations without departing from the principle of the present invention should be considered as the protection scope of the present invention.