Process method for preventing shell expansion of investment box type aluminum alloy casting

Abstract

The invention discloses a process method for preventing shell expansion of an investment box type aluminum alloy casting, which comprises the following steps: a box wax piece is vertically placed after being combined, and an ingate wax mold A and an ingate wax mold B are symmetrically adhered to two sides of the box wax piece; the ingate wax mold A is in contact with the position of a middle partition plate of the box body wax piece; the ingate wax mold A is in contact with the position above the position of the middle partition plate of the box body wax piece; the ingate wax mold B is in contact with the lower part of the middle partition plate of the box body wax piece; and an interval space is formed between the ingate wax mold A and the ingate wax mold B and corresponds to the box body wax pieces at the two ends of the middle partition plate in position. When the mold shell is dried, the interval space between the ingate wax mold A and the ingate wax mold B corresponds to the positions of box wax pieces at the two ends of the middle partition plate, and it is guaranteed that in the cooling process of the mold shell constructed through ventilation drying and wax mold sand blasting, the situation that the wax molds at the connecting positions of the two ends of the middle partition plate are dried and shrink unevenly is avoided; the problem that the shell expands and cracks when the metal liquid is poured is solved.

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 mold shell preparation process. 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 is composed of two cavities, the two cavities are separated by a partition 11 in the middle. The partition 11 has a thin wall thickness of 3mm. One side is a through cavity with a thicker side wall and uniform ribs 12. The other side is a cavity with a bottom surface and a thin wall thickness on all sides. 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 mold shell cools, 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 mold 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 an investment mold box type aluminum alloy casting, comprising:

[0006] The invention discloses a process method for achieving uneven drying shrinkage of the wax mold at the connection points at both ends of the middle partition.

[0007] The process method comprises: after the box wax parts are assembled, they are placed vertically, and the ingrate wax mold A and the ingrate wax mold B are symmetrically bonded to the two sides of the box wax parts;

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

[0009] The ingrate wax mold A contacts the upper part of the middle partition of the box wax part; the ingrate wax mold B contacts the lower part of the middle partition of the box wax part; there is a space 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 wax pattern is sandblasted as a whole to prepare the shell.

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

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

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

[0014] The beneficial effects of the present invention are as follows: 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 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, thus solving the problem of expansion and rupture of the mold shell when pouring molten metal. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a distribution schematic 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- ingrate wax mold A; 23- ingrate 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] A process for preventing shell expansion of an investment mold box type aluminum alloy casting of the present application comprises:

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

[0023] When the mold shell is drying, the spacing 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 of the mold 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 11 is avoided, and the problem of expansion and rupture of the mold shell when pouring liquid metal is solved.

Claims

1. A process for preventing shell expansion of investment mold box type aluminum alloy castings, characterized in that: include: A process method for achieving uneven drying and shrinkage of a wax mold at the connection points at both ends of a middle partition (11).

2. The process for preventing shell expansion of investment mold box-type aluminum alloy castings according to claim 1, characterized in that: The process method comprises: after assembling the box wax parts (21), the box wax parts (21) are placed vertically, and the two sides of the box wax parts (21) are symmetrically bonded with an endocastor wax mold A (22) and an endocastor wax mold B (23); The ingrate wax mold A (22) contacts the middle partition (11) of the box wax part (21); The ingrate wax mold A (22) contacts the position above the middle partition (11) of the box wax part (21); the ingrate 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 ingrate wax mold A (22) and the ingrate 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).

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

4. The process for preventing shell expansion of investment mold box type aluminum alloy castings according to claim 2, characterized in that: The ingrate 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).

5. The process for preventing shell expansion of investment mold box type aluminum alloy castings according to claim 2, characterized in that: The ingate wax mold B (23) contacts the middle partition (11) of the box wax part (21) at a position 20 mm to 25 mm below.

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