A process for preventing shell expansion of investment box type aluminum alloy castings

Abstract

The present invention discloses a process for preventing the shell expansion of investment wax box-type aluminum alloy castings, comprising: after the box wax parts are assembled, they are placed vertically, and an ingrow wax mold A and an ingrow wax mold B are symmetrically bonded on both sides of the box wax parts; the ingrow wax mold A contacts the middle partition position of the box wax parts, the ingrow wax mold A contacts the position above the middle partition position of the box wax parts; the ingrow wax mold B contacts the position below the middle partition position of the box wax parts; a space is provided between the ingrow wax mold A and the ingrow wax mold B, and the space corresponds to the position of the box wax parts at both ends of the middle partition. When the shell is drying, the space between the ingrow wax mold A and the ingrow wax mold B corresponds to the position of the box wax parts at both ends of the middle partition, ensuring ventilation and drying. During the cooling process of the shell constructed by wax mold sandblasting, the uneven drying and shrinkage of the wax mold at the connection between the two ends of the middle partition is avoided, thereby solving the problem of shell expansion and cracking when pouring molten metal.

Description

Technical Field

[0001] The invention relates to a process method for preventing shell expansion of an investment mold box type aluminum alloy casting, and belongs to the technical field of casting shell preparation technology. Background Art

[0002] Aluminum alloy investment castings are of various types, shapes, and complex structures. In the aluminum alloy investment casting production process, each casting molding process needs to go through mold making, shell making, pouring, post-processing and other processes to finally produce qualified castings. For the frame-shaped box casting 1, since the box casting 1 consists of two cavities, the two cavities are separated by a partition 11 in the middle. The wall thickness of the partition 11 is relatively thin, with a thickness of 3mm. One side is a through cavity with thicker side walls and uniform ribs 12. The other side is a cavity with a bottom surface and thinner walls around. See Figure 2 During the production process, due to the inconsistent thickness of the cavity wall at the connection points of the middle partition 11, when the wax mold sandblasting shell cools down, the wax mold at the connection points of the middle partition 11 dries and shrinks unevenly, causing the shell to bulge and crack when pouring molten metal. Summary of the Invention

[0003] In order to solve the above technical problems, the present invention provides a process method for preventing shell expansion of investment box type aluminum alloy castings.

[0004] The present invention is achieved through the following technical solutions.

[0005] The present invention provides a process for preventing shell expansion of investment box-type aluminum alloy castings, comprising:

[0006] A process method for achieving uneven drying shrinkage of the wax mold at the connection points of the middle partition.

[0007] The process method includes: assembling the box wax parts and placing them vertically, and symmetrically gating the sprue wax mold A and the sprue wax mold B on both sides of the box wax parts;

[0008] The sprue wax mold A contacts the middle partition of the box wax part;

[0009] The ingrate wax mold A contacts the upper portion of the middle partition of the box wax part; the ingrate wax mold B contacts the lower portion of the middle partition of the box wax part; a space is left between the ingrate wax mold A and the ingrate wax mold B, and the space corresponds to the position of the box wax part at both ends of the middle partition;

[0010] The entire wax pattern is sandblasted to prepare the shell.

[0011] The process method further includes: bonding the sprue wax mold to the outside of the ingrow wax mold A and the ingrow wax mold B.

[0012] The sprue wax mold A contacts the middle partition of the box wax part 20mm to 25mm above.

[0013] The sprue wax mold B contacts the middle partition of the box wax part 20mm to 25mm below.

[0014] The beneficial effects of the present invention are that: when the mold shell is drying, the space between the ingrow wax mold A and the ingrow wax mold B corresponds to the position of the box wax parts at both ends of the middle partition, ensuring ventilation and drying. During the cooling process of the mold shell constructed by sandblasting the wax mold, the uneven drying and shrinkage of the wax mold at the connection between the two ends of the middle partition is avoided, and the problem of the mold shell expanding and cracking when pouring molten metal is solved. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a distribution diagram of the present invention;

[0016] Figure 2 It is a structural diagram of box-type castings;

[0017] In the figure: 1-box casting; 11-middle partition; 12-rib;

[0018] 21- box wax parts; 22- inged channel wax mold A; 23- inged channel wax mold B; 24- sprue wax mold; 25- partition space. DETAILED DESCRIPTION

[0019] The technical solution of the present invention is further described below, but the scope of protection claimed is not limited to the description.

[0020] like Figure 1 shown.

[0021] The present invention provides a process for preventing shell expansion of investment box-type aluminum alloy castings, comprising:

[0022] After the box wax part 21 is assembled and formed as a whole, the box wax part 21 is placed vertically, and the ingrow wax mold A22 and the ingrow wax mold B23 are symmetrically glued on both sides of the box wax part 21; the ingrow wax mold A22 contacts the position of the middle partition 11 of the box wax part 21 at 20mm to 25mm above; the ingrow wax mold B23 contacts the position of the middle partition 11 of the box wax part 21 at 20mm to 25mm below; there is a spacing space 25 between the ingrow wax mold A22 and the ingrow wax mold B23, and the spacing space corresponds to the position of the box wax part 21 at both ends of the middle partition 11; then the straight runner wax mold 24 is glued to the outside of the ingrow wax mold A22 and the ingrow wax mold B23, and then the wax mold as a whole is sandblasted to prepare the mold shell.

[0023] When the mold shell is drying, the space 25 between the ingrow wax mold A22 and the ingrow wax mold B23 corresponds to the position of the box wax parts 21 at both ends of the middle partition 11, ensuring ventilation and drying. During the cooling process, the mold shell constructed by sandblasting the wax mold avoids the uneven drying and shrinkage of the wax mold at the connection between the two ends of the middle partition 11, and solves the problem of the mold shell expanding and breaking when pouring molten metal.

Claims

1. A process for preventing shell expansion of investment box type aluminum alloy castings, characterized in that: include: A process for achieving uneven drying and shrinkage of the wax mold at the connection points of the two ends of the middle partition (11); The process method comprises: assembling a box wax part (21) and placing it vertically, and symmetrically gating an endogate wax mold A (22) and an endogate wax mold B (23) on both sides of the box wax part (21); The sprue wax mold A (22) contacts the middle partition (11) of the box wax part (21); The ingrow wax mold A (22) contacts the position above the middle partition (11) of the box wax part (21); the ingrow wax mold B (23) contacts the position below the middle partition (11) of the box wax part (21); a space (25) is provided between the ingrow wax mold A (22) and the ingrow wax mold B (23), and the space corresponds to the position of the box wax part (21) at both ends of the middle partition (11).

2. The process for preventing shell expansion of investment box aluminum alloy castings according to claim 1, characterized in that: The process method further includes: bonding the sprue wax mold (24) to the outside of the ingrow wax mold A (22) and the ingrow wax mold B (23), and sandblasting the entire wax mold to prepare a mold shell.

3. The process for preventing shell expansion of investment box aluminum alloy castings according to claim 1, characterized in that: The sprue wax mold A (22) contacts the middle partition (11) of the box wax part (21) at a position 20 mm to 25 mm above the middle partition (11).

4. The process for preventing shell expansion of investment box aluminum alloy castings according to claim 1, characterized in that: The sprue wax mold B (23) contacts the middle partition (11) of the box wax part (21) at a position 20 mm to 25 mm below.

Images