KR100251336B1 - Variable mesh hatching method for convenient decubing operation - Google Patents

Abstract

PURPOSE: A method for hatching variable mesh for operation of simple decubing is provided to reduce the time for decubing and make the operation possible without the possibility of breakage of products by applying the adaptive mesh distance system. CONSTITUTION: In the method for hatching variable mesh for operation of simple decubing, a laying object(10), meshes(18, 28), the section shape(15) and a tetragonal boundary line(20) are included. The mesh(18) around the section shape(15) formed in the laying object(10) is hatched with a narrow interval and the mesh(28) in the far distance from the section shape(15) is hatched with a wide interval. The tetragonal boundary line(20) is formed around the section shape(15). And then the interval of mesh(18) becomes narrow on the inside of the tetragonal boundary line(20) and the interval mesh(28) becomes wide on the outside of the tetragonal boundary line(20) and the cutting operation is carried out.

Description

Variable mesh hatching method for easy decubing

The present invention relates to a rapid prototyping method for producing a prototype of a new product, and in particular, after the prototype of a predetermined shape is manufactured in a rapid manufacturing method using a lamination technique, it is easily separated from parts that do not need it. The present invention relates to a variable mesh hatching method for a decubing operation in which cubes in the form of hexahedrons formed together with prototype cross-sectional shapes are removed after completion of the work.

When developing a new product, it is necessary to verify the design or assemblability of the developed product. Currently, various rapid manufacturing methods are used for rapid prototyping in industry. The rapid fabrication method is characterized by fabricating three-dimensional prototypes by stacking sections using a three-dimensional computer-aided design (CAD) sliced to a predetermined thickness.

At present, a laminated object manufacturing (LOM) method developed by Helixis, USA, which is one of rapid manufacturing methods, is widely used. In the LOM method, the paper as each laminate is laminated on a platform moving in the z-axis direction and cut with a laser beam to produce a predetermined cross-sectional shape on the paper, and the process of laminating new paper and cutting the predetermined cross-sectional shape thereon is repeated. To produce a prototype. In the LOM method, when cutting each cross-sectional shape, unnecessary parts other than the required cross-sectional shape are cut into a mesh shape in order to easily remove after fabrication. That is, as shown in Fig. 1, a laminate of a new layer is placed and bonded on a laminate having a predetermined cross-sectional shape and a mesh, and then a cross-sectional shape and a mesh are formed in the new laminate again. This process is repeated until the desired thickness of the prototype is obtained. After this process is completed, if the unnecessary parts are removed to obtain a finished prototype, the parts cut into meshes are separated into cubes in the form of a cube, and thus such a removing operation is called a decubing operation.

2 shows the process of the decubing operation, which is made in the order of (a), (b), (c) and (d). First, the stacked LOM products are separated from the elevator plate of the equipment. Then, the wall portion surrounding the entire LOM product is removed to remove cubes and unnecessary parts except the product. The cube is then separated from the surface of the article and the surface of the article is painted, polished or sandblasted.

Typically, decubing work is time consuming because the decubing work is not done automatically but is done manually by experienced operator experience. In particular, when decubeing complex shapes, there is a risk that a part of the product will break when the cube is separated.

In the prior art, when cutting unnecessary portions in the form of a mesh, the spacing of the meshes is uniformly formed as shown in FIG. As shown in (a) of FIG. 3, when the distance between the meshes is increased, the size of the cube to be removed increases, thereby reducing the decube time, but increases the risk that the shape of the product is broken during the decube operation. Conversely, reducing the spacing of the mesh as shown in FIG. 3 (b) increases the overall decubing time but reduces the risk of shape breakage at complex shaped sites during decubing operations.

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems of the prior art, and to provide a variable mesh hatching method capable of partially adjusting the mesh spacing as necessary without having to make the spacing of the mesh constant.

1 is a schematic diagram illustrating a process of forming a product cross section and a mesh required for decubing in a prototype manufacturing method according to a conventional LOM method.

2 is a photograph showing a decube process.

Fig. 3 is a plan view of a laminate showing a constant spacing mesh formed by a conventional mesh hatching method, (a) is a plan view showing a mesh with large spacing and (b) shows a mesh with small spacing. Floor plan.

Figure 4 is a plan view of a laminate showing one embodiment of a variable spacing mesh formed according to the mesh hatching method according to the present invention.

Fig. 5 is a plan view of a laminate showing another embodiment of a variable spacing mesh formed according to the mesh hatching method according to the present invention.

<Explanation of symbols for the main parts of the drawings>

10: laminate

15: cross-sectional shape

18: mesh

20: rectangle border

28: mesh

According to the present invention, there is provided a mesh hatching method for use in a rapid manufacturing method for producing a prototype by stacking a plurality of laminates having a predetermined thickness in which a predetermined cross-sectional shape is cut and a portion other than the cross-sectional shape is cut in a mesh form. Mesh hatching method for classifying a laminate into a first mesh region proximate to the cross-sectional shape and a second mesh region surrounding the first mesh region, and making the mesh spacing of the first mesh region smaller than the mesh spacing of the second mesh region. This is provided.

Hereinafter, the present invention will be described in detail with reference to FIG. 4 in the accompanying drawings.

4 is a plan view of a laminate 10 in which meshes 18 and 28 are formed in accordance with one embodiment of the variable mesh hatching method of the present invention.

As can be seen in FIG. 4, the spacing of the meshes 18 is small hatched in the vicinity of the cross-sectional shape 15 formed in the stack 10, and the spacing of the mesh 28 is large at a point far from the cross-sectional shape 15. It is hatched. To do this, first, the rectangular boundary line 20 is formed around the cross-sectional shape 15. Then, the cutting operation is performed by reducing the spacing of the meshes 18 inside the rectangle boundary line 20 and increasing the spacing of the meshes 28 outside the rectangle boundary line 20.

The size of the rectangular boundary line 20 is determined to obtain the sliced cross-sectional information of the CAD model and to be suitable for the size of the cross-section. In this case, the interval between the meshes 18 inside the rectangular boundary line 20 should be such that the upper and lower mesh lines are connected to each other to form a cube as a whole. Outside the rectangular boundary 20, the mesh 28 is set to be as large as possible so that the cube can be easily separated during the decube operation.

5, there is shown a top view of a laminate having a mesh formed in accordance with another embodiment of the variable mesh hatching method of the present invention. In FIG. 5, the boundary line is circular according to the circular cross-sectional shape of the product, and other configurations are similar to those of FIG. Therefore, according to this invention, a boundary line shape can be made into shapes other than a rectangle and a circle according to the cross-sectional shape of a product.

In this way, the mesh spacing is reduced at the boundary of the cross-sectional shape of the product, and the mesh spacing is increased at the portion without the cross-sectional shape because it is separated from the cross-sectional shape of the product, that is, by applying an adaptive mesh distance method. The ice time is reduced and decubbing can be performed without the possibility of product breakage.

In the conventional LOM equipment, the decubing line (mesh) interval is constant, so many difficulties are involved in the decubing operation, but using the variable mesh hatching method using the adaptive mesh distance method according to the present invention, as well as after the prototype production time Processing time is also greatly reduced. In addition to the existing LOM process, the present invention can be used in the "applied three-dimensional printer using the lamination technique" developed by the applicant.

Claims (1)

In the mesh hatching method used in the rapid manufacturing method of manufacturing a prototype by stacking a plurality of laminates having a predetermined thickness in which a predetermined cross-sectional shape is cut and a portion other than the cross-sectional shape is cut in a mesh form, Each laminate is divided into a first mesh region close to the cross-sectional shape and a second mesh region surrounding the first mesh region, and the mesh spacing of the first mesh region is smaller than the mesh spacing of the second mesh region. A mesh hatching method characterized by the above-mentioned.