A molding process for separate core making of shaft and hole

Abstract

This invention relates to the field of casting technology, specifically to a molding process for separate core making of shafts and holes. The process includes the following steps: the core portion is made in two stages using molds; when both parts are hardened and ready for demolding, a professional casting sand mold adhesive is applied to their contact surfaces; then, the two parts are assembled together and bound with thin steel wire. This invention optimizes the production molding and mold process, improving efficiency. Separate core making of the hole involves chilling the cores separately on the molds. After the sand layer hardens, the cores are assembled and bonded together, then bound with thin steel wire to complete the core-making process. The resulting chilled cores have an attractive, regular shape that meets process requirements. This demonstrates that the shaft-hole separate core making molding process provided by this invention has a broader market prospect and is more suitable for promotion.

Description

Technical Field

[0001] This invention relates to the field of casting technology, specifically to a molding process for separate core making of shaft and hole. Background Technology

[0002] Casting is one of the earliest metal heat treatment techniques mastered by humankind, with a history of approximately 6,000 years. China entered its golden age of bronze casting around 1700-1000 BC, achieving a remarkably high level of craftsmanship. Casting involves pouring molten metal into a cavity conforming to the shape of the part, allowing it to cool and solidify to obtain the part or blank. The material being cast is often a metal that was originally solid but heated to a molten state (e.g., copper, iron, aluminum, tin, lead), while the mold material can be sand, metal, or even ceramic. Different methods are used depending on the specific requirements.

[0003] Sometimes the shape and structure of the hole determines the mold structure, and it needs to be connected with other parts. When this happens, the mold hole is horizontal in the mold structure. If chills need to be placed, the upper half-circle chill located on the sand-pounding surface cannot be placed. The chill can only be placed in the lower half-circle position. In this way, only half of the chill is placed, which is very asymmetrical and uniform, and cannot play the role of rapid cooling and refining the structure.

[0004] Therefore, the present invention provides a molding process for separate core making of shaft and hole to solve the related technical problems mentioned above. Summary of the Invention

[0005] The purpose of this invention is to provide a molding process for separate shaft and hole core making. The molding process for separate shaft and hole core making provided by this invention optimizes the production molding and mold process, improves efficiency, and separates the cores for each hole. After the sand layer hardens, they are then assembled and bonded together and bound and fixed with thin iron wire to complete the core making process. The resulting chilled irons have an attractive and regular shape that meets the process requirements.

[0006] To achieve the above objectives, the present invention provides the following technical solution:

[0007] A molding process for separate shaft and hole core making includes the following steps:

[0008] Ⅰ. The core part is made using a mold in two stages;

[0009] II. Once the two parts from step I have hardened and are ready to be demolded, apply professional casting sand mold adhesive to the contact surfaces between them.

[0010] III. Then assemble the two together and bind them with thin steel wire.

[0011] The present invention is further configured such that the process of fabricating the core portion in step I using a mold in two stages is as follows:

[0012] A mold is used to leave half of the core portion on the corresponding main body, while the other half is made separately.

[0013] The present invention is further configured such that the casting production sand mold adhesive in step II is made from the following raw materials in parts by weight: 35-40 parts aggregate, 12-14 parts auxiliary agent, 8-10 parts curing agent, 2-3 parts coupling agent and 50-60 parts deionized water;

[0014] The auxiliary agent is one or a mixture of several of phenolic resin, polyester resin, and polyamide resin in any proportion;

[0015] The curing agent is either p-toluenesulfonic acid or hexamethylenetetramine;

[0016] The coupling agent is either silane coupling agent KH550 or silane coupling agent KH56.

[0017] A further provision of the present invention is that the aggregate is modified coal gangue, and the preparation process of the modified coal gangue is as follows:

[0018] Coal gangue powder and sodium amino acid are mixed evenly at a mass ratio of 1.0:0.2-0.3;

[0019] Then, after roasting in a muffle furnace, add hydrogen chloride solution at a solid-liquid ratio of 1:4 and heat to acidify for 60-70 minutes.

[0020] After cooling, the material is filtered and dried in a drying oven at 120°C to obtain modified coal gangue.

[0021] A further feature of the present invention is that the particle size of the coal gangue powder is 150-160 mesh.

[0022] The present invention is further configured such that the baking process is divided into three stages, namely:

[0023] First stage: Heat to 720℃ at a rate of 10℃ / min and keep warm for 30-40 minutes;

[0024] Second stage: Increase the temperature to 750℃ at a rate of 5℃ / min and keep it at that temperature for 60-70 minutes.

[0025] The third stage: cool down to 700℃ at a rate of 12℃ / min and keep warm for 10-12 minutes.

[0026] A further feature of this invention is that the concentration of the hydrogen chloride solution is 1.2 mol / L.

[0027] A further provision of the present invention is that the preparation process of the casting production sand mold adhesive is as follows:

[0028] i. Accurately weigh the aggregate, auxiliary agent, curing agent, coupling agent and deionized water respectively. Dissolve the aggregate in deionized water and ultrasonically disperse for 15-20 minutes to obtain an ultrasonic dispersion.

[0029] ii. Mix the ultrasonic dispersion from step i with the auxiliary agent, curing agent, and coupling agent at 30°C and 330–420 r / min for 60–90 min to obtain the casting sand mold adhesive.

[0030] Compared with the prior art, the beneficial effects of the present invention are:

[0031] This invention optimizes the production design and mold process, improving efficiency. The core is made by separating the holes and chilling them separately on the mold. After the sand layer hardens, they are then assembled and bonded together, and bound and fixed with thin iron wire to complete the core-making process. The chilled irons that are placed out have an attractive and regular shape, meeting the process requirements. This shows that the shaft and hole separate core-making process provided by this invention has a broader market prospect and is more suitable for promotion. Attached Figure Description

[0032] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0033] Figure 1 This is a flowchart of a core-making process for separating shaft holes according to the present invention;

[0034] Figure 2 This is a process diagram of a shaping process for separating the shaft and hole core according to the present invention. In the figure, A is a schematic diagram of the single-piece core part, B is a schematic diagram after binding with thin steel wire, and C is the effect diagram after the shaping is completed.

[0035] Figure 3 This is a statistical chart showing the solid content in the sand mold adhesive used in the casting production process of this invention. Detailed Implementation

[0036] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention. Example 1

[0037] like Figures 1-2 As shown, this embodiment provides a molding process for separate core making of shaft and hole, including the following steps:

[0038] Ⅰ. The core part is made using a mold in two stages.

[0039] The process of fabricating the core portion using a mold in two stages is as follows:

[0040] A mold is used to leave half of the core portion on the corresponding main body, while the other half is made separately.

[0041] That is, there is only one half cylinder. When core-making the main part, chills are placed as needed. Since the hole is only half, the upper part is empty, providing enough space for pounding sand without affecting the operation. Similarly, chills are also placed on the other half as needed.

[0042] II. Once the two parts from step I have hardened and are ready to be demolded, apply professional casting sand mold adhesive to the contact surfaces of the two parts.

[0043] The casting sand mold adhesive is made from the following raw materials by weight: 35 parts aggregate, 12 parts auxiliary agent, 8 parts curing agent, 2 parts coupling agent and 50 parts deionized water.

[0044] The auxiliary agent is phenolic resin;

[0045] The curing agent is p-toluenesulfonic acid;

[0046] The coupling agent is silane coupling agent KH550.

[0047] The aggregate is modified coal gangue, and the preparation process of the modified coal gangue is as follows:

[0048] Coal gangue powder and sodium amino acid are mixed evenly at a mass ratio of 1.0:0.2;

[0049] Then, after roasting in a muffle furnace, add hydrogen chloride solution at a solid-liquid ratio of 1:4 and heat to acidify for 60 minutes.

[0050] After cooling, the material is filtered and dried in a drying oven at 120°C to obtain modified coal gangue.

[0051] The particle size of the coal gangue powder is 150 mesh.

[0052] The baking process is divided into three stages:

[0053] First stage: Heat to 720℃ at a rate of 10℃ / min and keep warm for 30 minutes;

[0054] Second stage: Increase the temperature to 750℃ at a rate of 5℃ / min and keep it at that temperature for 60 minutes.

[0055] The third stage: cool down to 700℃ at a rate of 12℃ / min and keep warm for 10 minutes.

[0056] A further feature of this invention is that the concentration of the hydrogen chloride solution is 1.2 mol / L.

[0057] Furthermore, the preparation process of the casting mold adhesive is as follows:

[0058] i. Accurately weigh the aggregate, auxiliary agent, curing agent, coupling agent and deionized water respectively. Dissolve the aggregate in deionized water and ultrasonically disperse for 15 minutes to obtain an ultrasonic dispersion.

[0059] ii. Mix the ultrasonic dispersion from step i with the auxiliary agent, curing agent, and coupling agent at 30°C and 330 r / min for 60 min to obtain the casting sand mold adhesive.

[0060] III. Then assemble the two together and bind them with thin steel wire. Example 2

[0061] like Figure 1 As shown, this embodiment provides a molding process for separate core making of shaft and hole, including the following steps:

[0062] Ⅰ. The core part is made using a mold in two stages.

[0063] The process of fabricating the core portion using a mold in two stages is as follows:

[0064] A mold is used to leave half of the core portion on the corresponding main body, while the other half is made separately.

[0065] That is, there is only one half cylinder. When core-making the main part, chills are placed as needed. Since the hole is only half, the upper part is empty, providing enough space for pounding sand without affecting the operation. Similarly, chills are also placed on the other half as needed.

[0066] II. Once the two parts from step I have hardened and are ready to be demolded, apply professional casting sand mold adhesive to the contact surfaces of the two parts.

[0067] The casting sand mold adhesive is made from the following raw materials by weight: 37 parts aggregate, 13 parts auxiliary agent, 9 parts curing agent, 3 parts coupling agent and 60 parts deionized water;

[0068] The auxiliary agent is polyester resin;

[0069] The curing agent is hexamethylenetetramine;

[0070] The coupling agent is silane coupling agent KH56.

[0071] The aggregate is modified coal gangue, and the preparation process of the modified coal gangue is as follows:

[0072] Coal gangue powder and sodium amino acid are mixed evenly at a mass ratio of 1.0:0.3;

[0073] Then, after roasting in a muffle furnace, add hydrogen chloride solution at a solid-liquid ratio of 1:4 and heat to acidify for 65 minutes.

[0074] After cooling, the material is filtered and dried in a drying oven at 120°C to obtain modified coal gangue.

[0075] The particle size of the coal gangue powder is 155 mesh.

[0076] The baking process is divided into three stages:

[0077] First stage: Heat to 720℃ at a rate of 10℃ / min and hold for 35 minutes;

[0078] Second stage: Increase the temperature to 750℃ at a rate of 5℃ / min and hold for 65min.

[0079] The third stage: cool down to 700℃ at a rate of 12℃ / min and keep warm for 11 minutes.

[0080] A further feature of this invention is that the concentration of the hydrogen chloride solution is 1.2 mol / L.

[0081] Furthermore, the preparation process of the casting mold adhesive is as follows:

[0082] i. Accurately weigh the aggregate, auxiliary agent, curing agent, coupling agent and deionized water respectively. Dissolve the aggregate in deionized water and ultrasonically disperse for 15-20 minutes to obtain an ultrasonic dispersion.

[0083] ii. The ultrasonic dispersion from step i is mixed with the auxiliary agent, curing agent, and coupling agent at 30°C and 375 r / min for 75 min to obtain the casting sand mold adhesive.

[0084] III. Then assemble the two together and bind them with thin steel wire. Example 3

[0085] like Figure 1 As shown, this embodiment provides a molding process for separate core making of shaft and hole, including the following steps:

[0086] Ⅰ. The core part is made using a mold in two stages.

[0087] The process of fabricating the core portion using a mold in two stages is as follows:

[0088] A mold is used to leave half of the core portion on the corresponding main body, while the other half is made separately.

[0089] That is, there is only one half cylinder. When core-making the main part, chills are placed as needed. Since the hole is only half, the upper part is empty, providing enough space for pounding sand without affecting the operation. Similarly, chills are also placed on the other half as needed.

[0090] II. Once the two parts from step I have hardened and are ready to be demolded, apply professional casting sand mold adhesive to the contact surfaces of the two parts.

[0091] The casting sand mold adhesive is made from the following raw materials in parts by weight: 40 parts aggregate, 14 parts auxiliary agent, 10 parts curing agent, 3 parts coupling agent and 60 parts deionized water;

[0092] The auxiliary agent is one or a mixture of several of phenolic resin, polyester resin, and polyamide resin in any proportion;

[0093] The curing agent is hexamethylenetetramine;

[0094] The coupling agent is silane coupling agent KH56.

[0095] The aggregate is modified coal gangue, and the preparation process of the modified coal gangue is as follows:

[0096] Coal gangue powder and sodium amino acid are mixed evenly at a mass ratio of 1.0:0.3;

[0097] Then, after roasting in a muffle furnace, add hydrogen chloride solution at a solid-liquid ratio of 1:4 and heat to acidify for 70 minutes.

[0098] After cooling, the material is filtered and dried in a drying oven at 120°C to obtain modified coal gangue.

[0099] The particle size of the coal gangue powder is 160 mesh.

[0100] The baking process is divided into three stages:

[0101] First stage: Heat to 720℃ at a rate of 10℃ / min and keep warm for 40 minutes;

[0102] Second stage: Increase the temperature to 750℃ at a rate of 5℃ / min and keep it at that temperature for 70min;

[0103] The third stage: cool down to 700℃ at a rate of 12℃ / min and keep warm for 12 minutes.

[0104] A further feature of this invention is that the concentration of the hydrogen chloride solution is 1.2 mol / L.

[0105] Furthermore, the preparation process of the casting mold adhesive is as follows:

[0106] i. Accurately weigh the aggregate, auxiliary agent, curing agent, coupling agent and deionized water respectively. Dissolve the aggregate in deionized water and ultrasonically disperse for 15-20 minutes to obtain an ultrasonic dispersion.

[0107] ii. The ultrasonic dispersion from step i is mixed with the auxiliary agent, curing agent, and coupling agent at 30°C and 420 r / min for 90 min to obtain the casting sand mold adhesive.

[0108] III. Then assemble the two together and bind them with thin steel wire.

[0109] Test on the effectiveness of casting mold adhesive in production:

[0110] The casting production sand mold glue samples prepared in Examples 1 to 3 were tested according to the testing standards, and the test data are recorded in Table 1.

[0111] Table 1: Test Data Recording Sheet for Sand Mold Adhesive in Foundry Production

[0112] Group Solid content (%) Gas production (ml / g) Tensile strength at room temperature (MPa) Viscosity (mPa.s) at 25℃ Example 1 55 88 2.8 4452 Example 2 56 86 2.8 4458 Example 3 54 87 2.8 4451

[0113] From Table 1 and Figure 3 It can be seen that the casting sand mold adhesive prepared by the present invention can meet the requirements of casting production.

[0114] This invention optimizes the production design and mold process, improving efficiency. The core is made by separating the holes and chilling them separately on the mold. After the sand layer hardens, they are then assembled and bonded together, and bound and fixed with thin iron wire to complete the core-making process. The chilled irons that are placed out have an attractive and regular shape, meeting the process requirements. This shows that the shaft and hole separate core-making process provided by this invention has a broader market prospect and is more suitable for promotion.

[0115] In the description of this specification, references to terms such as "an embodiment," "example," "specific example," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0116] The preferred embodiments of the present invention disclosed above are merely illustrative of the invention. These preferred embodiments do not exhaustively describe all details, nor do they limit the invention to the specific implementations described. Clearly, many modifications and variations can be made based on the content of this specification. This specification selects and specifically describes these embodiments to better explain the principles and practical applications of the invention, thereby enabling those skilled in the art to better understand and utilize the invention. The invention is limited only by the claims and their full scope and equivalents.

Claims

1. A molding process for separate core making of shaft and hole, characterized in that, Includes the following steps: Ⅰ. The core part is made using a mold in two stages; II. Once the two parts from step I have hardened and are ready to be demolded, apply professional casting sand mold adhesive to the contact surfaces between them. III. Then assemble the two together and bind them with thin steel wire; The casting sand mold adhesive in step II is made from the following raw materials in parts by weight: 35-40 parts aggregate, 12-14 parts auxiliary agent, 8-10 parts curing agent, 2-3 parts coupling agent, and 50-60 parts deionized water; the auxiliary agent is one or a mixture of several of phenolic resin, polyester resin, and polyamide resin in any proportion; the curing agent is any one of p-toluenesulfonic acid or hexamethylenetetramine; the coupling agent is any one of silane coupling agent KH550 or silane coupling agent KH56. The aggregate is modified coal gangue, and the preparation process of the modified coal gangue is as follows: coal gangue powder and sodium amino acid are mixed evenly at a mass ratio of 1.0:0.2-0.3; then placed in a muffle furnace for calcination, and then added to a hydrogen chloride solution at a solid-liquid ratio of 1:4 and heated and acidified for 60-70 minutes; after cooling, it is filtered and dried in a drying oven at 120°C to obtain modified coal gangue; The baking process is divided into three stages: the first stage: heating to 720°C at a rate of 10°C / min and baking at that temperature for 30-40 minutes; the second stage: heating to 750°C at a rate of 5°C / min and baking at that temperature for 60-70 minutes; and the third stage: cooling to 700°C at a rate of 12°C / min and baking at that temperature for 10-12 minutes.

2. The molding process for separate core making of shaft holes according to claim 1, characterized in that, The process of making the core part in step I using a mold in two stages is as follows: one half of the core part is left on the corresponding main body using a mold, while the other half is made separately.

3. The molding process for separating the shaft hole and core as described in claim 1, characterized in that: The particle size of the coal gangue powder is 150-160 mesh.

4. The molding process for separating the shaft hole and core as described in claim 1, characterized in that: The concentration of the hydrogen chloride solution is 1.2 mol / L.

5. The molding process for separating the shaft hole core according to claim 1, characterized in that: The preparation process of the casting production sand mold adhesive is as follows: i. Accurately weigh the aggregate, auxiliary agent, curing agent, coupling agent and deionized water respectively, dissolve the aggregate in deionized water and ultrasonically disperse for 15-20 min to obtain an ultrasonic dispersion; ii. Mix the ultrasonic dispersion from step i with the auxiliary agent, curing agent and coupling agent at 30℃ and 330-420 r / min for 60-90 min to obtain the casting production sand mold adhesive.

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