CN111151735A

CN111151735A - Casting mould

Info

Publication number: CN111151735A
Application number: CN201911202260.6A
Authority: CN
Inventors: 康进武; 郑乐乐; 王建庄; 王纪武
Original assignee: Wuhan Digital Design And Manufacturing Innovation Center Co ltd; Tsinghua University; Beijing Jiaotong University
Current assignee: Wuhan Digital Design And Manufacturing Innovation Center Co ltd; Tsinghua University; Beijing Jiaotong University
Priority date: 2019-11-29
Filing date: 2019-11-29
Publication date: 2020-05-15
Anticipated expiration: 2039-11-29
Also published as: CN111151735B

Abstract

The invention provides a casting mold which comprises a wall part, wherein a cavity for forming a casting is surrounded by the wall part, at least one hollow cavity is arranged inside the wall part, and each hollow cavity is filled with a filler, wherein the heat transfer performance of the filler of each hollow cavity is adapted to the cooling speed required by the part, adjacent to the hollow cavity, of the casting. The design of the wall part meets the heat transfer requirements of different parts in the forming process of the casting, realizes the control of the local cooling speed of the casting, effectively reduces the defects of shrinkage cavity and shrinkage porosity, residual stress and deformation of the casting in the forming process, improves the solidification structure of the casting, and improves the size precision and performance of the casting.

Description

Casting mould

Technical Field

The invention relates to the technical field of casting, in particular to a casting mold.

Background

In the casting cooling forming process, different parts have different heat transfer requirements in different stages, for example, in the solidification stage, sequential cooling from bottom to top is needed, in addition, the cooling speed needs to be increased for thick parts, and the cooling speed needs to be reduced for thin parts, so as to realize balanced solidification, thereby ensuring that the casting is compact and has few shrinkage cavity and shrinkage porosity defects.

Disclosure of Invention

In view of the problems in the background art, the present invention aims to provide a casting mold which can meet the heat transfer requirements of different parts in the casting forming process, so that the local cooling speed of the casting is controlled, and the casting quality is improved.

In order to achieve the above object, the present invention provides a mold, which comprises a wall portion enclosing a cavity for forming a casting, at least one hollow cavity being provided inside the wall portion, each hollow cavity being filled with a filler, wherein the heat transfer performance of the filler of each hollow cavity is adapted to the cooling rate required by the casting at a portion adjacent to the hollow cavity.

In one embodiment, the hollow cavities are multiple; at least one partition part is further arranged inside the wall part, and each partition part separates two adjacent hollow cavities in the height direction.

In one embodiment, the wall part is further provided with at least one injection hole, and each injection hole is arranged on the outer side of the wall part and is communicated with the corresponding hollow cavity; the casting mould also comprises a sealing element which is arranged in each injection hole in a sealing mode.

In one embodiment, each injection hole extends obliquely downward from the outer side of the wall portion.

In one embodiment, the filler may be a powder material or a granular material with high heat transfer performance.

In one embodiment, the particulate material having high heat transfer properties may be steel or iron shot.

In one embodiment, the filler may be a powder material or a granular material having low heat transfer properties.

In one embodiment, the powder material with low heat transfer performance is perlite powder.

In one embodiment, the cast is formed via 3D printing.

In one embodiment, the material of the mold is selected from molding sand or metal powder.

The invention has the following beneficial effects:

in the casting mould, the design of the wall part meets the heat transfer requirements of different parts in the casting forming process, the control of the local cooling speed of the casting is realized, the shrinkage cavity and shrinkage porosity defects, the residual stress and the deformation of the casting in the forming process are effectively reduced, the solidification structure of the casting is improved, and the dimensional precision and the performance of the casting are improved.

Drawings

FIG. 1 is a partial cross-sectional view of a mold according to the present invention, wherein each hollow cavity is filled with a filler.

FIG. 2 is a partial cross-sectional view of a mold according to the present invention, wherein each hollow cavity is not filled with a filler.

Wherein the reference numerals are as follows:

1 wall part 14 injection hole

11 filling of the cavity F

12H height direction of the hollow cavity

13 spacer part

Detailed Description

The accompanying drawings illustrate embodiments of the present invention and it is to be understood that the disclosed embodiments are merely exemplary of the invention, which can be embodied in various forms, and therefore, specific details disclosed herein are not to be interpreted as limiting, but merely as a basis for the claims and as a representative basis for teaching one skilled in the art to variously employ the present invention.

The mould according to the invention comprises a wall part 1. The mold also includes a seal (not shown).

Referring to fig. 1 and 2, the wall portion 1 comprises a mould cavity 11 and at least one hollow cavity 12. The wall 1 further comprises at least one spacer 13 and at least one injection hole 14.

A mould cavity 11 is enclosed by the wall 1 and is used for shaping the casting. At least one hollow cavity 12 is arranged inside the wall part 1, and each hollow cavity 12 is filled with a filler F, wherein the heat transfer performance of the filler F of each hollow cavity 12 is adapted to the cooling speed required by a part of the casting, which is adjacent to the hollow cavity 12, that is, when a certain part of the casting requires to increase the cooling speed in the forming process, a hollow cavity 12 adjacent to the part is filled with a material with good heat transfer effect (high heat transfer performance); if a certain part of the casting requires to reduce the cooling speed, the hollow cavity 12 adjacent to the part is filled with a material with a weak heat transfer effect (namely, a good heat preservation effect).

At least one hollow cavity 12 is arranged on the wall 1, and the heat transfer performance of the filler F of each hollow cavity 12 is adapted to the cooling speed required by the part of the casting adjacent to the hollow cavity 12, so that in the process of forming the casting, a heat transfer material meeting the heat transfer requirement of the part can be filled in the corresponding hollow cavity 12 of the wall 1 (the hollow cavity 12 corresponding to the part of the casting) according to the heat transfer requirements of different parts of the casting, for example, a material with low heat transfer performance (low heat conductivity or low specific heat) can be filled in the corresponding accommodating cavity 12 of the wall 1 aiming at a riser of the casting, the upper part of the casting or the thin-wall part on a feeding channel, so as to generate a heat preservation effect, or a preheated high heat storage material is added in the part, so as to realize the heat preservation effect; aiming at the bottom part, thick and large part and other parts of the casting needing to improve the cooling speed, a material with high heat transfer performance (high heat conductivity or high specific heat) can be filled in the corresponding accommodating cavity 12 of the wall part 1 to play a role in accelerating the cooling, so that the design of the wall part 1 (filling the hollow cavity 12 of the wall part 1 with a filler F meeting the heat transfer requirement) meets the heat transfer requirements of different parts in the casting forming process, the control of the local cooling speed of the casting is realized, the defects of shrinkage cavity and shrinkage porosity of the casting in the forming process are effectively reduced, the solidification structure of the casting is improved, and the size precision and the performance of the casting are improved; in addition, the design form improves the cooling efficiency of the casting, shortens the cooling time of the casting and improves the production efficiency.

In one embodiment, the filler F may be a powder material or a granular material with high heat transfer performance. The powder material or the granular material with high heat transfer performance is filled in the corresponding hollow cavity 12, so that the cooling speed of the part of the casting corresponding to the hollow cavity 12 can be accelerated, the heat transfer requirements of different parts of the casting are met, and the overall quality of the casting is ensured. The particulate material having high heat transfer properties may be steel shot or iron shot. Of course, the material with high heat transfer performance can be other materials meeting the requirement, and can be selected according to specific situations. It should be noted that, when the filler F is made of a granular material, in order to increase the cooling speed, the size of the single granular material may be made small enough to increase the density of the filler F, thereby achieving the purpose of increasing the cooling speed.

In another embodiment, the filler F may be a powder material or a granular material having a low heat transfer property. The powder material or the granular material with low heat transfer performance is filled in the corresponding hollow cavity 12, so that the heat preservation effect can be realized on the part of the casting corresponding to the hollow cavity 12, the cooling speed of the part of the casting is reduced, the heat transfer requirements of different parts of the casting are met, and the overall quality of the casting is ensured. The powder material with low heat transfer performance may be perlite powder. Of course, other materials with satisfactory low heat transfer properties may be used and will not be described in detail here.

In one embodiment, the hollow cavities 12 in the interior of the wall portion 1 are provided in plurality; the interior of the wall portion 1 is further provided with at least one spacer 13, and each spacer 13 spaces two adjacent hollow cavities 12 apart in the height direction H. The partition portion 13 is of an integral structure with the wall portion 1, and the partition portion 13 can separate two types of fillers F with different heat transfer properties, which are accommodated in two adjacent hollow cavities 12.

In an embodiment the wall part 1 is further provided with at least one injection hole 14. Each injection hole 14 of the wall part 1 is arranged on the outer side (the side far away from the cavity 11) of the wall part 1 and is communicated with the corresponding hollow cavity 12; preferably, each injection hole 14 extends obliquely downward from the outside of the wall portion 1. The injection holes 14 are provided so that the powder material or the granular material described above can be smoothly filled into the corresponding hollow cavities 12. It should be noted that, when the filler F is injected into the hollow cavity 12 located at the uppermost side, it may be directly injected through the opening at the upper end of the hollow cavity 12, and thus, the hollow cavity 12 located at the uppermost side need not be provided with the injection hole 14 corresponding thereto.

The above-described sealing member is sealingly provided in each injection hole 14 so that the filler F filled in the corresponding hollow chamber 12 is not spilled from the injection hole 14. In one embodiment, the sealing member is a clay paste.

In the cast according to the invention, the cast is formed via 3D printing. 3D printing and forming can form a casting mold with a complex internal structure. The casting mold is made of molding sand or metal powder, namely the casting mold can be a sand mold or a metal mold, so that the forming requirements of different castings can be met.

The above detailed description describes exemplary embodiments, but is not intended to limit the combinations explicitly disclosed herein. Thus, unless otherwise specified, various features disclosed herein can be combined together to form a number of additional combinations that are not shown for the sake of brevity.

Claims

1. A mould, characterized in that it comprises a wall (1), the wall (1) enclosing a mould cavity (11) for forming a casting, at least one hollow cavity (12) being provided inside the wall (1), each hollow cavity (12) being filled with a filling (F), wherein the heat transfer properties of the filling (F) of each hollow cavity (12) are adapted to the cooling rate required at the part of the casting adjacent to said hollow cavity (12).

2. The mold according to claim 1,

the hollow cavities (12) are multiple;

at least one partition part (13) is further arranged inside the wall part (1), and each partition part (13) separates two adjacent hollow cavities (12) along the height direction (H).

3. The mold according to claim 2,

the wall part (1) is also provided with at least one injection hole (14), and each injection hole (14) is arranged on the outer side of the wall part (1) and communicated with the corresponding hollow cavity (12);

the mould further comprises a sealing member sealingly arranged in each injection hole (14).

4. The mould as claimed in claim 3, characterised in that each injection opening (14) extends obliquely downwards from the outside of the wall part (1).

5. The casting mould as claimed in claim 1, wherein the filler (F) is a powder material or a granular material having high heat transfer properties.

6. Casting mould according to claim 5, characterized in that the granular material with high heat transfer properties can be steel shot or iron shot.

7. The casting mould as claimed in claim 1, wherein the filler (F) is a powder material or a granular material having low heat transfer properties.

8. The casting mold as claimed in claim 7, wherein the powder material having low heat transfer property is perlite powder.

9. The mold as recited in claim 1, wherein the mold is formed via 3D printing.

10. The mold according to claim 9, wherein the material of the mold is selected from the group consisting of sand and metal powder.