A method for preparing a multi-channel narrow-lumen wax pattern for precision investment casting

Abstract

This application relates to a method for preparing a wax pattern for multi-channel narrow-cavity investment casting in the field of casting technology. The method includes: designing a water-soluble cold core mold, a water-soluble core mold, and a wax pattern mold according to the casting; installing at least one first core into the water-soluble cold core mold and injecting water-soluble wax to form an integral cold core; installing the integral cold core into the water-soluble core mold, installing at least one second core, positioning the second core relative to the first core, and injecting water-soluble wax to form a combined core; attaching a mold outline structure block to the side of the first and second cores away from the water-soluble core, and then installing the entire assembly into the wax pattern mold, injecting wax material to form an integral wax pattern; opening the wax pattern mold, removing the mold outline structure block, extracting the first and second cores, and dissolving the water-soluble core to obtain the casting wax pattern. The wax pattern preparation method of this application has the advantages of strong process designability, low water-soluble core wax material consumption, and good economy, and can improve the surface quality, dimensional accuracy, and dimensional stability of the wax pattern.

Description

Technical Field

[0001] This application relates to the field of casting technology, and in particular to a method for preparing a wax pattern for precision investment casting with a multi-channel narrow internal cavity. Background Technology

[0002] With the rapid development of aviation, aerospace and other fields, titanium alloy castings are becoming increasingly integrated and complex in structure. In particular, oil and gas pipeline components have narrow cavities and numerous channels. Due to limitations in casting structure, mold technology and testing capabilities, it is impossible to achieve integrated molding of wax molds and a high pass rate.

[0003] For highly integrated titanium and titanium alloy castings with narrow internal cavities and multi-channel structures, traditional techniques often involve preparing complete wax models by pressing wax into separate molds and then assembling the wax models. This method suffers from problems such as difficulty in repairing the joints of the wax models, poor surface quality, unstable dimensions, and low yield. Alternatively, a water-soluble core can be pressed into a mold, then placed into the main mold to form an integral wax model. The water-soluble core is then dissolved to obtain the wax model. However, this method suffers from problems such as high consumption of water-soluble core wax, inaccurate positioning of the water-soluble core, unstable dimensions, and low yield. Summary of the Invention

[0004] The main objective of this invention is to provide a method for preparing a wax pattern for precision casting with a multi-channel narrow internal cavity investment mold, aiming to solve at least one of the above-mentioned technical problems.

[0005] To achieve the above objectives, the present invention proposes a method for preparing a wax pattern for multi-channel narrow-cavity investment casting, comprising: designing a first core, a second core, a water-soluble cold core mold, a water-soluble core mold, and a wax pattern mold according to the casting;

[0006] At least one first core is inserted into a water-soluble cold core mold, water-soluble wax is injected, and the combination structure of the water-soluble cold core and the first core is pressed out to form an integral cold core. The integral cold core is inserted into a water-soluble core mold, at least one second core is inserted, the second core is positioned relative to the first core, water-soluble wax is injected, and the water-soluble wax layer wraps around the water-soluble cold core to form a water-soluble core. The water-soluble core, the first core, and the second core form a combined core. A mold outer structure block is attached to the side of the first core and the second core away from the water-soluble core, and then the whole thing is inserted into a wax mold, wax material is injected, and an integral wax model is formed. The wax mold is opened, the mold outer structure block is removed, the first core and the second core are extracted, and the integral wax model containing the water-soluble core is placed in water. After the water-soluble core dissolves, a casting wax model is obtained.

[0007] In some embodiments of the present invention, the melting points of the first core and the second core are higher than those of the water-soluble wax.

[0008] In some embodiments of the present invention, both the first core and the second core are made of metal.

[0009] In some embodiments of the present invention, a mold block is assembled on the side of the combined core away from the mold outer shape block, one end of the second core is inserted into the mold block, and then the whole is installed into the wax mold.

[0010] In some embodiments of the present invention, the first core and the second core are positioned by a connecting block.

[0011] In some embodiments of the present invention, a first groove adapted to one end of the first core and a second groove adapted to one end of the second core are formed on one side of the connecting block.

[0012] In some embodiments of the present invention, the first core and the second core are respectively fixed to the first groove and the second groove by screws.

[0013] In some embodiments of the present invention, the connecting block is made of metal.

[0014] In some embodiments of the present invention, a third groove adapted to one end of the first core and a fourth groove adapted to one end of the second core are formed on the mold outer shape structure block.

[0015] In some embodiments of the present invention, the first core and the second core are respectively fixed to the third groove and the fourth groove by screws.

[0016] Compared with the prior art, the present invention achieves the following technical effects:

[0017] 1. The water-soluble cold core mold, water-soluble core mold and wax mold of the present invention have simple structure, are easy to install and disassemble, and have low mold cost.

[0018] 2. The present invention designs a water-soluble cold core in the water-soluble core, which can significantly reduce the deformation of the water-soluble core and achieve high dimensional accuracy forming of the water-soluble core, thereby improving the dimensional accuracy of the wax pattern and castings used for casting.

[0019] 3. The present invention uses a first core, a second core, and a connecting block of metal for positioning, which makes the channel position and size stable and enables the high-precision channel structure forming.

[0020] 4. The present invention uses a combined core technology to press wax patterns, resulting in wax patterns with good surface quality, high wall thickness uniformity, and good dimensional stability.

[0021] 5. This invention employs a combined core technology, using a first core and a second core, which reduces the amount of water-soluble core material used, accelerates the dissolution rate of the water-soluble core, reduces production costs, and improves production efficiency. Attached Figure Description

[0022] Various other advantages and benefits will become apparent to those skilled in the art upon reading the following detailed description of preferred embodiments. The accompanying drawings are for illustrative purposes only and are not intended to limit the scope of this application. Furthermore, the same reference numerals denote the same parts throughout the drawings. In the drawings:

[0023] Figure 1 This is a cross-sectional view of the wax pattern for casting according to the present invention;

[0024] Figure 2 This is a three-dimensional view of the wax pattern for casting of the present invention;

[0025] Figure 3 This is a cross-sectional view of the overall cold core of the present invention;

[0026] Figure 4 This is a perspective view of the overall cold core of the present invention;

[0027] Figure 5 This is a cross-sectional view of the composite core of the present invention;

[0028] Figure 6 This is a perspective view of the composite core of the present invention;

[0029] Figure 7 This is a cross-sectional view of the overall wax model of the present invention;

[0030] Figure 8 This is a three-dimensional view of the overall wax model of the present invention.

[0031] The labels in the attached diagram represent the following: 1. Water-soluble cold core; 2. First core; 3. Second core; 4. Connecting block; 5. Screw; 6. Water-soluble wax layer; 7. Mold outer structure block; 8. Mold movable block; 9. Wax pattern; 10. Water-soluble core. Detailed Implementation

[0032] It should be understood that the described embodiments are merely some, not all, of the embodiments in this application. All other embodiments obtained by those skilled in the art based on the embodiments in this application without inventive effort are within the scope of protection of this application.

[0033] In the following description, when referring to the accompanying drawings, the same numbers in different drawings denote the same or similar elements unless otherwise indicated. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with this application. Rather, they are merely examples of apparatuses and methods consistent with some aspects of this application as detailed in the appended claims.

[0034] In the description of this application, it should be understood that the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances. Furthermore, in the description of this application, unless otherwise stated, "multiple" refers to two or more. "And / or" describes the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. The character " / " generally indicates that the preceding and following related objects are in an "or" relationship.

[0035] The following is in conjunction with the appendix Figure 1-8 The method for preparing a wax pattern for precision casting with a multi-channel narrow internal cavity investment pattern provided in the embodiments of this application will be described.

[0036] This application discloses a method for preparing a wax pattern for multi-channel narrow-cavity investment casting. The method includes the following steps:

[0037] 1) Design molds.

[0038] 11) Based on the structure of the casting, design wax pattern 9 for casting. Wax pattern 9 is a proportional replica of the casting, such as... Figure 1 and Figure 2 As shown, wax model 9 includes a shell, and at least two channels are formed inside the shell. Each channel has a channel opening and a channel cavity.

[0039] 12) First, based on the degree of straightness of the channel connecting with the outside world, design a columnar first core 2 or second core 3 at the channel opening. The first core 2 is inserted into the housing through the channel opening, with one end of the first core 2 inside the housing and the other end of the first core 2 extending out of the housing. The second core 3 is inserted into the housing through the channel opening, with both ends of the second core 3 extending out of the housing.

[0040] 13) Secondly, based on the narrowness of the channel cavity and the degree of non-linearity of the connection with the outside world, a water-soluble cold core 1 is designed first in the channel cavity. A gap is provided between the water-soluble cold core 1 and the inner wall of the wax pattern 9. The water-soluble cold core 1 and the first core 2 are combined to form an integral cold core.

[0041] Furthermore, a water-soluble cold core mold is designed according to the overall cold core design. The water-soluble cold core mold is used to form a water-soluble cold core 1 that is bonded to the first core 2 on the first core 2.

[0042] 14) In addition, a water-soluble core 10 is designed in the inner cavity of the channel. The outer surface of the water-soluble core 10 can fit the inner wall of the wax pattern 9. The water-soluble core 10 is wrapped with a water-soluble cold core 1. The water-soluble core 10 is combined with the first core 2 and the second core 3 to form a combined core.

[0043] Furthermore, a water-soluble core mold is designed according to the combined core design. The water-soluble core mold is used to form a water-soluble core 10 that is combined with the water-soluble cold core 1 on the water-soluble cold core 1, the first core 2 and the second core 3.

[0044] 15) After that, based on the wax pattern 9 and the composite core, design the wax mold. The wax mold is used to form an integral wax pattern that is combined with the composite core on the composite core.

[0045] 2) Prepare the integral cold core.

[0046] like Figure 3 and Figure 4 As shown, the first core 2 is inserted into the water-soluble cold core mold, water-soluble wax is injected, and the combined structure of the water-soluble cold core 1 and the first core 2 is pressed out to form an integral cold core.

[0047] Furthermore, the first core 2 is made of a material with a melting point higher than that of water-soluble wax; the first core 2 is preferably made of metal, including but not limited to one or more alloys of aluminum, copper, and iron.

[0048] 3) Prepare the composite core.

[0049] like Figure 5 and Figure 6 As shown, the entire cold core is inserted into the water-soluble core mold, the second core 3 is inserted, the second core 3 is positioned relative to the first core 2, water-soluble wax is injected, the water-soluble wax layer 6 wraps around the water-soluble cold core 1 to form the water-soluble core 10, and the water-soluble core 10 is combined with the first core 2 and the second core 3 to form a combined core.

[0050] Furthermore, the second core 3 is made of a material with a melting point higher than that of water-soluble wax; the second core 3 is preferably made of metal, including but not limited to one or more alloys of aluminum, copper, and iron.

[0051] Furthermore, the first core 2 and the second core 3 are positioned by a connecting block 4; one side of the connecting block 4 has a first groove that matches one end of the first core 2 and a second groove that matches one end of the second core 3; the first core 2 and the second core 3 are respectively fixed in the first groove and the second groove by screws 5.

[0052] Preferably, the connecting block 4 is made of metal, including but not limited to one or an alloy of aluminum, copper, and iron.

[0053] 4) Prepare the overall wax model.

[0054] like Figure 7 and Figure 8As shown, remove the connecting block 4 from the combined core, insert the annular wax core along the first core 2 and the second core 3 (if necessary), and then install the mold shape structure block 7 on the side of the first core 2 and the second core 3 away from the water-soluble core 10 to realize the positioning function of the first core 2 and the second core 3 and the shape structure function of the overall wax model. Then, insert the whole into the wax mold, inject wax material, and form the overall wax model.

[0055] Furthermore, the mold block 8 is assembled on the side of the combined core away from the mold outer structure block 7 (only a part of the mold block is shown in the figure), one end of the second core 3 is inserted into the mold block 8, and then the whole thing is put into the wax mold.

[0056] Furthermore, the mold outer structure block 7 has a third groove adapted to one end of the first core 2 and a fourth groove adapted to one end of the second core 3; the first core 2 and the second core 3 are respectively fixed to the third groove and the fourth groove by screws 5.

[0057] 5) Obtain a wax pattern for casting.

[0058] Open the wax mold, remove the mold outer structure block 7 and the mold movable block 8, extract the first core 2 and the second core 3, put the whole wax model containing the water-soluble core 10 into water, and after the water-soluble core 10 dissolves, the casting wax model 9 is obtained.

[0059] The present invention provides a method for preparing wax patterns for multi-channel, narrow-cavity investment casting, applicable to the preparation of wax patterns for multi-channel, narrow-cavity investment casting. This method provides a solution for the integrated molding of wax patterns for multi-channel, narrow-cavity titanium and titanium alloy castings. Through this method, integrated wax patterns for multi-channel, narrow-cavity investment casting with good surface quality, high dimensional accuracy, high yield, and low cost can be prepared.

[0060] This preparation method uses a combination of a first and second metal core and a water-soluble core to achieve integrated molding of wax patterns for multi-channel, narrow-cavity titanium and titanium alloy castings. The first and second cores are reusable, which is economical and can reduce the consumption of water-soluble core wax. Furthermore, the combination of the first and second cores with the water-soluble cold core results in good surface quality, high dimensional accuracy, and good dimensional stability of the wax pattern.

[0061] The above description is merely a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A method for producing a wax pattern for multi-channel narrow-lumen investment precision casting, characterized by, include: The design includes the first core, the second core, the water-soluble cold core mold, the water-soluble core mold, and the wax mold, based on the casting design. At least one first core is inserted into a water-soluble cold core mold, water-soluble wax is injected, and a combined structure of the water-soluble cold core and the first core is pressed out to form an integral cold core. The entire cold core is inserted into the water-soluble core mold, at least one second core is inserted, the second core is positioned relative to the first core, water-soluble wax is injected, the water-soluble wax layer is wrapped around the water-soluble cold core to form the water-soluble core, and the water-soluble core, the first core and the second core form a combined core. The mold outline structure block is installed on the side of the first and second cores away from the water-soluble core, and then the whole thing is put into the wax mold, and wax is injected to form a whole wax model; Open the wax mold, remove the outer structural blocks of the mold, extract the first and second cores, and put the whole wax model containing the water-soluble core into water. After the water-soluble core dissolves, the wax model for casting is obtained.

2. The method for preparing a wax pattern for multi-channel narrow-cavity investment casting according to claim 1, characterized in that, The melting points of the first core and the second core are higher than those of the water-soluble wax.

3. The method for preparing a wax pattern for multi-channel narrow-cavity investment casting according to claim 2, characterized in that, Both the first core and the second core are made of metal.

4. The method for preparing a wax pattern for multi-channel narrow-cavity investment casting according to claim 1, characterized in that, The mold block is assembled on the side of the combined core away from the mold outer structure block, one end of the second core is inserted into the mold block, and then the whole is installed into the wax mold.

5. The method for preparing a wax pattern for multi-channel narrow-cavity investment casting according to claim 1, characterized in that, The first core and the second core are positioned by a connecting block.

6. The method for preparing a wax pattern for multi-channel narrow-cavity investment casting according to claim 5, characterized in that, One side of the connecting block has a first groove adapted to one end of the first core and a second groove adapted to one end of the second core.

7. The method for preparing a wax pattern for multi-channel narrow-cavity investment casting according to claim 6, characterized in that, The first core and the second core are respectively fixed to the first slot and the second slot by screws.

8. The method for preparing a wax pattern for multi-channel narrow-cavity investment casting according to claim 6, characterized in that, The connecting block is made of metal.

9. The method for preparing a wax pattern for multi-channel narrow-cavity investment casting according to claim 1, characterized in that, The mold outer structural block has a third groove that matches one end of the first core and a fourth groove that matches one end of the second core.

10. The method for preparing a wax pattern for multi-channel narrow-cavity investment casting according to claim 9, characterized in that, The first core and the second core are respectively fixed in the third groove and the fourth groove by screws.

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