CN108580803B

CN108580803B - Sand mold model near-forming method based on layering principle

Info

Publication number: CN108580803B
Application number: CN201810351950.7A
Authority: CN
Inventors: 刘丰; 单忠德; 张帅; 顾兆现
Original assignee: Beijing Jike Guochuang Lightweight Science Research Institute Co Ltd
Current assignee: Beijing Jike Guochuang Lightweight Science Research Institute Co Ltd
Priority date: 2018-04-19
Filing date: 2018-04-19
Publication date: 2020-08-11
Anticipated expiration: 2038-04-19
Also published as: CN108580803A

Abstract

A sand mold model near-forming method based on a layering principle aims to realize digital near-forming of sand molds. The method is realized by the following steps: (1) according to the z-direction size l of the sand mold three-dimensional model_zDetermining the near forming precision delta z according to the near forming precision requirement; (2) dividing a near forming area of the sand mold three-dimensional model into m layers along the z direction, wherein m is l_zΔ z, each layer being designated B₁，…，B_k，…，B_mAnd (3) the filler cell array is composed of p × q subunits U_i,jComposition, fill subunit U_i,jGradually increasing the height from the plane of z to 0 along the z direction for filling the sand mold cavity, wherein the gradually increasing height is delta z; (4) if filling the subunit U_i,jAnd B₁，B₂，…，B_k‑1All have no intersection and are B_kIf there is intersection, the subunit U is filled_i,jIncreasing height h_i,jΔ z × (k-1), and (5) obtaining each of the filler subunits U of the filler unit array in turn according to the step (4)_i,jHeight of (2)

The method can enable the near-forming sand mold cavity to quickly approach the target sand mold cavity within an error range.

Description

Sand mold model near-forming method based on layering principle

Technical Field

The invention relates to a sand mold modeling technology for casting, in particular to a sand mold model near-forming method based on a layering principle.

Background

Due to the increasing severity of environmental problems and the increasing awareness of environmental protection, a green manufacturing wave is raised worldwide, and the development of green manufacturing technology is promoted. The green manufacturing is used as a low-entropy production manufacturing mode, and the requirement of minimizing environmental pollution is always met in the whole life cycle from the design, manufacture and use to the scrapping of the product; the environment is not harmful or has little harm to the ecological environment, and the aim of environmental protection is fulfilled; and has the advantages of high utilization rate of raw materials and low energy consumption.

The application of the digital dieless casting precision forming technology in sand mold forming greatly improves the green level of casting mold manufacturing in the casting field, omits the manufacturing process of a wood mold or a metal mold and saves a large amount of raw materials. However, the problem of large removal amount of medium sand in the sand block cutting process of the digital die-free casting precision forming technology reduces the production efficiency of sand mould batch production to a certain extent, and the popularization of the technology in sand mould batch production is severely restricted. In order to solve the problems, a sand mold model near forming method based on a layering principle is provided, so that the sand mold near forming is realized, the sand mold production time is shortened, the production efficiency is improved, and the molding sand material and energy are saved.

The invention provides a sand mold model near-forming method based on a layering principle for sand mold near-forming.

Disclosure of Invention

The invention provides a sand mold model near-forming method based on a layering principle, and aims to realize digital flexible extrusion near-forming of a sand mold, effectively reduce waste of molding sand and improve molding efficiency and quality of the sand mold.

In order to achieve the purpose, the invention is realized by adopting the following technical scheme.

The length, width and height are respectively a × p, b × q and l_zThe three-dimensional model of the sand mold CAD is equally divided into m layers along the height direction, the height of each layer is delta z, and each layer is named as B₁，…，B_k，…，B_m(ii) a Wherein m is

∈Z,1≤k≤m。

The filler cell array is composed of p × q subunits U with a cross-sectional area of a × b_i,jComposition, fill subunit U_i,jAnd gradually increasing the height from the plane of Z to 0 along the Z direction for filling the sand mold cavity, wherein the gradually increased height is delta Z, p ∈ Z, q ∈ Z, i is more than or equal to 1 and less than or equal to p, and j is more than or equal to 1 and less than or equal to q.

Filling of the sub-unit U_i,jWhether or not to react with B₁，B₂，…，B_k-1Logic judgment with intersection; if with B_kIf there is intersection, the subunit U is filled_i,jIncreasing height h_i,jΔ z × (k-1), if there is no intersection, filling the subunit U_i,jWhether or not to react with B_k+1Logic judgment with intersection; and so on.

According to the logic judgment result, sequentially obtaining each filling subunit U of the filling unit array_i,jHeight of (2)

And entering a filling unit array shape adjusting procedure, and performing sand filling and molding after the shape adjustment is finished.

Brief Description of Drawings

FIG. 1 is a schematic diagram of a sand mold model near-forming method based on the layering principle,

1 is a sand mold with the layer height divided according to delta z, and 2 is a sand mold model filling unit.

Detailed Description

The present invention will be described in detail below with reference to the embodiments with reference to the attached drawings.

As shown in figure 1, the invention relates to a sand mold model near-forming method based on a layering principle.

As shown in FIG. 1, the sand mold pattern packing unit array 2 is a packing subunit U with the length, width and height of 80mm, 80mm and variable height respectively_i,jThe 10 × 8 array is formed, wherein i is more than or equal to 1 and less than or equal to 10, and j is more than or equal to 1 and less than or equal to 8.

The length, the width and the height of the sand mold model are respectively 800mm, 640mm and 300mm, the sand mold model is divided into 300 layers along the height direction, the height of each layer is 1mm, namely the approximate forming precision is 1 mm; naming each layer as B from bottom to top₁，…，B_k，…，B₃₀₀Wherein k is greater than or equal to 1 and less than or equal to 300 for k ∈ Z.

Filler subunit U_i,jAnd starting from a plane of 0, the height of the mold cavity is increased gradually along the z direction to fill the mold cavity, and the height of the mold cavity is increased gradually by 1 mm.

Filling of the sub-unit U_i,jWhether or not to react with B₁，B₂，…，B_k-1Logic judgment with intersection; if a fill subunit U is present_i,jAnd B₁，B₂，…，B_k-1Without intersection, if with B_kIf there is intersection, the subunit U is filled_i,jIncreasing height h_i,jΔ z × (k-1), if there is no intersection, filling the subunit U_i,jWhether or not to react with B_k+1Logic judgment with intersection; and so on.

Obtaining each filling subunit U of the filling unit array in turn_i,jHeight of (2)

Claims

1. A sand mold model near-forming method based on a layering principle is characterized in that:

(1) a × p, b × q and l according to length, width and height_zZ-direction dimension l of sand mold CAD three-dimensional model_zDetermining the near forming precision delta z according to the near forming precision requirement;

(2) dividing a near-forming area of the sand mold CAD three-dimensional model into m layers along the z direction, wherein m is l_zΔ z, each layer being designated B₁，…，B_k，…，B_mWherein m ∈ Z, k is more than or equal to 1 and less than or equal to m;

(3) the length, width and height of the filler cell array are p × q, and are a, b and h respectively_i,jSubunit U of_i,jComposition, fill subunit U_i,jStarting from a plane of Z-0, gradually increasing along the Z direction to fill a sand mold cavity, wherein the gradually increasing height is delta Z, i is more than or equal to 1 and less than or equal to p, and j is more than or equal to 1 and less than or equal to q;

(4) if filling the subunit U_i,jAnd B₁，B₂，…，B_k-1All have no intersection and are B_kIf there is intersection, the subunit U is filled_i,jIncreasing height h_i,j＝Δz×(k-1)；

(5) According to the step (4), filling subunits U of the filling unit array are obtained in sequence_i,jHeight H ═ of

(6) And entering a filling unit array shape adjusting procedure, and performing sand filling and molding after the shape adjustment is finished.