Combined hollow core waxing head for investment casting

Abstract

The utility model discloses a combined hollow wax discharge head for investment casting, and relates to the technical field of investment casting. The combined hollow wax discharge head for investment casting comprises a wax piece arranged on the inner side of a shell, and a lower wax discharge head arranged on the inner side of the shell. The lower wax discharge head is located on the outer wall of the wax piece, and the wax piece and the lower wax discharge head are both medium-temperature wax. The lower wax discharge head and the upper wax discharge head adopt a hollow structure, which greatly increases the heating area. The combined design of the lower wax discharge head and the upper wax discharge head is matched with wax materials with different melting points. When the wax is removed, the low-temperature invasion sealing wax melts first, and quickly opens part of the wax discharge channel. Then, the upper and lower wax discharge heads with the hollow structure melt faster than the wax piece due to the larger heating area. Before the wax piece starts to melt, a complete and unblocked wax discharge path is formed. This design greatly speeds up the wax discharge, effectively shortens the wax removal time, speeds up the production cycle, and reduces the risk of shell cracking.

Description

Technical Field

[0001] This utility model relates to the field of investment casting technology, specifically a combined hollow wax discharge head for investment casting. Background Technology

[0002] Investment casting, also known as lost-wax casting, is a precision casting process mainly used to produce metal parts with complex shapes and high precision requirements. A precise wax model is made from a fusible material (such as wax), assembled into a tree-like structure, and then repeatedly coated with refractory material to form a multi-layered hard shell. The wax model is heated to melt and flow out, resulting in a hollow shell. The shell is then baked at high temperature to enhance its strength and remove residues. Molten metal is then poured into the shell, cooled, and the outer shell is broken off. The sprue is then removed to obtain the precision casting.

[0003] In the investment casting process, the wax removal process is a key step that determines the quality of the mold shell and production efficiency.

[0004] During the dewaxing process, the uneven thickness of the wax and the uneven heat transfer between the wax and the mold shell cause inconsistent melting speeds of the wax, making it difficult to open the wax discharge channel quickly. When the melted wax expands in volume due to high temperature and accumulates in large quantities in the mold shell and cannot be discharged in time, it will generate a large internal pressure, which can easily cause the mold shell to crack. This not only affects the molding quality of the casting and increases the scrap rate, but also reduces production efficiency and increases production costs. Therefore, a combined hollow wax discharge head for investment casting is proposed. Utility Model Content

[0005] To address the shortcomings of existing technologies, this utility model provides a combined hollow wax discharge head for investment casting. This solves the problem that when a large amount of wax accumulates inside the mold shell and cannot be discharged in time, it will generate significant internal pressure, which can easily cause the mold shell to crack. This not only affects the molding quality of the casting and increases the scrap rate, but also reduces production efficiency and increases production costs.

[0006] To achieve the above objectives, this utility model is implemented through the following technical solution: it includes a mold shell and a wax part disposed inside the mold shell, wherein a lower row of wax heads is disposed inside the mold shell;

[0007] The lower row of wax heads is located on the outer wall of the wax piece, and both the wax piece and the lower row of wax heads are medium-temperature waxes.

[0008] Preferably, the outer wall of the lower wax head is bonded with adhesive wax, and the bottom surface of the adhesive wax is bonded to the top surface of the wax piece. The adhesive wax is used to connect the lower wax head to the wax piece.

[0009] Preferably, the lower wax head is fitted with an upper wax head on its outer wall, and the top of the upper wax head extends to the outside of the mold shell. The lower and upper wax heads adopt a hollow structure, which greatly increases the heating area. Both the lower and upper wax heads use medium-temperature wax, and because of their large heating area, the lower and upper wax heads melt faster than the wax parts. The wax discharge channel is opened before the wax parts melt, reducing the occurrence of mold shell cracking.

[0010] Preferably, the outer wall of the lower row of wax heads and the upper row of wax heads are covered with sealing wax.

[0011] Preferably, the outer wall of the impregnation wax is in contact with the inner side of the mold shell, and the impregnation wax is a low-temperature wax. Since the impregnation wax is a low-temperature wax, it will melt first after heating, making room for a portion of the wax discharge channel.

[0012] This invention provides a combined hollow wax removal head for investment casting. It has the following advantages:

[0013] (i) This is a combined hollow wax removal head for investment casting. The lower and upper wax removal heads adopt a hollow structure, which greatly increases the heating area. Combined with the combination design of waxes with different melting points, during dewaxing, the low-temperature impregnating wax melts first, quickly opening up some wax removal channels. Then, the hollow upper and lower wax removal heads, with their larger heating area, melt faster than the wax parts, building a complete and unobstructed wax removal path before the wax parts begin to melt. This design greatly accelerates the wax removal speed, effectively shortens the dewaxing time, speeds up the production cycle, improves the production efficiency of investment casting, and uses ordinary medium-temperature wax, which can be reused.

[0014] (II) This combined hollow wax removal head for investment casting opens the wax removal channel in time before the wax melts, avoiding the problem of a sharp increase in internal pressure of the mold shell caused by the accumulation of melted wax. This greatly reduces the risk of mold shell cracking, reduces casting defects caused by mold shell damage, and significantly improves the casting qualification rate, providing a reliable guarantee for the production of high-quality castings in investment casting. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the overall structure of this utility model;

[0016] Figure 2 This is a schematic diagram of the overall internal structure of this utility model;

[0017] Figure 3 This is a schematic diagram of the connection between the lower wax head and the wax part in this utility model;

[0018] Figure 4 This is a schematic diagram of the internal structure of the lower and upper wax heads of this utility model.

[0019] In the diagram: 1. Shell; 2. Lower row of wax heads; 3. Sealing wax; 4. Adhesive wax; 5. Wax part; 6. Upper row of wax heads. Detailed Implementation

[0020] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0021] Please see Figure 1-4 The present invention provides a technical solution: including a shell 1 and a wax part 5 disposed inside the shell 1, and a lower row of wax heads 2 disposed inside the shell 1;

[0022] The lower row of wax heads 2 is located on the outer wall of the wax part 5. Both the wax part 5 and the lower row of wax heads 2 are medium-temperature waxes. The outer wall of the lower row of wax heads 2 is bonded with adhesive wax 4. The bottom surface of the adhesive wax 4 is bonded to the top surface of the wax part 5. The outer wall of the lower row of wax heads 2 is fitted with an upper row of wax heads 6. The top of the upper row of wax heads 6 extends to the outside of the mold shell 1. The outer wall of the lower row of wax heads 2 and the upper row of wax heads 6 are fitted with impregnation wax 3. The outer wall of the impregnation wax 3 is in contact with the inner side of the mold shell 1. The impregnation wax 3 is a low-temperature wax.

[0023] When using the product, during dewaxing, first use a cutting saw to remove the top of the upper wax head 6, then place it in the dewaxing kettle for heating and dewaxing. At this time, high-temperature steam envelops the entire mold shell 1. The lower melting point of the impregnating wax 3 melts first, making room for a portion of the wax discharge channel. Since the main body of the upper wax head 6 and the lower wax head 2 is hollow, the upper wax head 6 and the lower wax head 2 have a large heating area, and their melting speed is faster than that of the wax part 5. The wax discharge channel is opened before the wax part 5 melts, reducing the occurrence of mold shell 1 cracking.

[0024] It should be noted that, in this document, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0025] Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A combined hollow core waxing head for investment casting, comprising a shell (1) and a wax piece (5) arranged inside the shell (1), characterized in that: The inner side of the shell (1) is provided with a lower row of wax heads (2); The lower row of wax heads (2) is located on the outer wall of the wax piece (5), and both the wax piece (5) and the lower row of wax heads (2) are medium-temperature waxes.

2. The combined hollow wax removal head for investment casting according to claim 1, characterized in that: The lower wax head (2) is bonded with adhesive wax (4) on its outer wall, and the bottom surface of the adhesive wax (4) is bonded to the top surface of the wax piece (5).

3. A combined hollow wax removal head for investment casting according to claim 1, characterized in that: The lower row of wax heads (2) is fitted with an upper row of wax heads (6) on its outer wall, and the top of the upper row of wax heads (6) extends to the outside of the shell (1).

4. A combined hollow wax removal head for investment casting according to claim 3, characterized in that: The outer wall of the lower row of wax heads (2) and the upper row of wax heads (6) are covered with sealing wax (3).

5. A combined hollow wax removal head for investment casting according to claim 4, characterized in that: The outer wall of the sealing wax (3) is in contact with the inner side of the shell (1), and the sealing wax (3) is a low temperature wax.

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