Casting process for nodular cast iron bearing retainer

Abstract

The invention discloses a casting technology for a nodular cast iron bearing retainer. The casting technology comprises the steps that S1, a precoated sand shell mold is designed through the nodular cast iron bearing retainer; s2, a shell mold is manufactured, an upper shell mold and a lower shell mold are manufactured through the shell mold, and then the upper shell mold and the lower shell mold are connected into a precoated sand shell mold; s3, iron shots are flatly laid at the bottom of a sand box and then compacted through vibration, the precoated sand shell mold is placed on the iron shots in the sand box, the space between the inner wall of the sand box and the precoated sand shell mold is filled with the iron shots layer by layer from bottom to top, the iron shots are compacted through vibration, molten iron is poured into a mold cavity of the precoated sand shell mold, and after cooling, the molten iron is solidified and formed into a bearing retainer casting; and S4, the precoated sand shell mold is separated from the iron shots, the precoated sand shell mold is knocked, broken and removed from the outer side of the bearing retainer casting, and the internally-formed bearing retainer casting is obtained. The process is simple in step, the quality of the bearing retainer casting can be effectively improved, the casting cost is low, the production efficiency is improved, and the probability of defective products is reduced.

Description

Technical Field

[0001] The present application relates to the technical field of bearing retainer casting, and in particular to a ductile iron bearing retainer casting process. Background Art

[0002] The bearing retainer is an important component of the bearing, which partially wraps all the rolling elements to isolate the rolling elements, guide the rolling elements to roll and keep them in the bearing. The existing market uses centrifugal cast copper as raw material for production, but with the continuous increase in copper costs, the raw materials are scarce. At the same time, leaded brass has no material available for copper retainers due to the problem of Pb precipitation. Therefore, the domestic and international bearing markets have an increasing demand for ductile iron bearing retainers. The existing production methods of ductile iron bearing retainers are ordinary sand casting or centrifugal casting. Among them, ordinary sand casting has serious internal defects in castings, high scrap rates, and substandard casting performance due to process, raw materials, process control and other reasons, making it difficult to achieve large-scale mass production; and centrifugal casting has a material utilization rate of only 8% due to process limitations, and the processing volume is very large, resulting in high production costs, which does not meet the current needs of lightweight and cost reduction. Therefore, seeking new bearing retainer casting processing methods has become an urgent issue. At present, there is a technical solution for casting ductile iron bearing retainers by an iron-coated sand casting process, such as the iron-coated sand casting process for ductile iron used for spherical roller bearing retainers disclosed in application No. 202311625050.4. With the help of this process, the quality of bearing retainer castings can be improved. However, in this process, it is necessary to first design a set of initial upper and lower molds for manufacturing upper iron molds and lower iron molds. The upper iron mold and lower iron mold manufactured by the initial upper and lower molds constitute the upper and lower molds for pouring molten iron. Specifically, the upper iron mold and the lower iron mold respectively form an upper sand box and a lower sand box, and the upper sand box and the lower sand box are combined to obtain a sand box, and a cavity for pouring molten iron is formed in the sand box. After the casting is formed, the upper sand box and the lower sand box are changed back to the upper iron mold and the lower iron mold, and the upper iron mold and the lower iron mold need to be cleaned to ensure that the cavity is clean before the next molding. This process requires the design of two sets of casting molds, namely the initial upper and lower molds and the upper and lower iron molds. A molding machine is required to form a sand film on the inner walls of the upper and lower molds and the upper and lower iron molds. The process is complicated and costly. Finally, the upper and lower iron molds need to be cleaned of the sand film on the inner walls before they can be recycled. The production efficiency is low. Improper cleaning will also affect the molding quality of the next casting, increasing the risk of defective castings. Summary of the invention

[0003] The present application provides a ductile iron bearing retainer casting process to solve at least one of the technical problems existing in conventional bearing retainer ordinary sand casting, centrifugal casting and other processes, such as serious internal defects of castings, high scrap rate and high cost.

[0004] The technical solution adopted in this application is:

[0005] A ductile iron bearing retainer casting process, comprising: S1 shell mold design: pre-drawing a bearing retainer model drawing and a matching coated sand shell mold model drawing using computer-aided software, wherein the coated sand shell mold comprises an upper shell mold and a lower shell mold, the upper shell mold and the lower shell mold enclose a cavity matching the outline of the bearing retainer casting, the upper shell mold and the lower shell mold have the same structure and can be made using the same shell mold; S2 shell mold making: casting a shell mold, configuring coated sand, covering the coated sand in the shell mold, heating the shell mold, making an upper shell mold, taking out the upper shell mold from the shell mold, waiting for the shell mold to cool, covering the coated sand in the shell mold, heating the shell mold, making a lower shell mold The upper shell mold and the lower shell mold are connected and matched to form a complete coated sand shell mold; S3 pouring: the pig iron, scrap steel, and alloy materials are subjected to high-temperature melting, spheroidization, and inoculation treatment to obtain molten iron, and iron shots are spread on the bottom of the sand box and then vibrated, and the coated sand shell mold is placed on the iron shots at the bottom of the sand box, and iron shots are filled layer by layer from bottom to top between the inner wall of the sand box and the coated sand shell mold, and each layer of iron shots is filled and vibrated before the next layer of iron shots is filled, and the molten iron is poured into the mold cavity of the coated sand shell mold, and after cooling, the molten iron solidifies and forms a bearing retainer casting; S4 taking out: separating the coated sand shell mold from the iron shots, and knocking and crushing the coated sand shell mold from the outside of the bearing retainer casting to obtain an internally formed bearing retainer casting.

[0006] Furthermore, the S2 shell mold production specifically includes: S21: casting a shell mold, configuring coated sand, covering the coated sand in the shell mold, heating the shell mold, obtaining an upper shell mold, the upper shell mold is connected with a coated sand upper cover, taking out the upper shell mold from the shell mold, and waiting for the shell mold to cool; S22: covering the coated sand in the shell mold, heating the shell mold, obtaining a lower shell mold, the lower shell mold is connected with a coated sand lower cover; S23: the upper shell mold and the lower shell mold are connected and cooperated to form a complete coated sand shell mold, while the coated sand upper cover and the coated sand lower cover are connected and cooperated to form a casting channel connecting the mold cavity.

[0007] Further, the S21 specifically includes: casting a shell mold, a first movable block is arranged on one side of the shell mold, wherein the first movable block is detachably connected to the shell mold for quick replacement, and a mold cavity suitable for a coated sand upper cover is provided in the first movable block; configuring coated sand, covering the coated sand in the shell mold and the first movable block, heating the shell mold and the first movable block, obtaining an upper shell mold and a coated sand upper cover connected together, and removing the upper shell mold from the shell mold while the coated sand upper cover is separated from the first movable block, and waiting for the shell mold to cool; the S22 specifically includes: a second movable block is arranged on one side of the shell mold, wherein the second movable block is detachably connected to the shell mold for quick replacement, and a mold cavity suitable for a coated sand lower cover is provided in the second movable block; covering the coated sand in the shell mold and the second movable block, heating the shell mold and the second movable block, obtaining a lower shell mold and a coated sand lower cover connected together, and removing the lower shell mold from the shell mold while the coated sand lower cover is separated from the second movable block.

[0008] Furthermore, a pouring inlet is provided at one end of the pouring channel, and a pouring outlet connected to the mold cavity is provided at the other end. The pouring channel includes a cross runner, a flow control runner and a riser in sequence from the pouring inlet toward the pouring outlet. The flow control runner is provided with two outlet ends symmetrically arranged about the cross runner, and each of the outlet ends is connected to one of the risers.

[0009] Furthermore, in the pouring S3, the specific operation of pouring the molten iron into the mold cavity of the coated sand shell mold is: connecting the pouring piece with the sprue to the pouring channel, and pouring the molten iron into the mold cavity of the coated sand shell mold through the sprue and the pouring channel.

[0010] Furthermore, the casting includes a vertical flow guide part and a transverse connecting part connected to the side of the vertical flow guide part, the straight runner is formed in the vertical flow guide part, a pouring cup is provided on the top of the vertical flow guide part, and the transverse connecting part is used to connect to the entrance of the pouring channel.

[0011] Furthermore, the specific operation of compaction is: placing the sand box on a three-dimensional compaction table and compacting it by the three-dimensional compaction table.

[0012] Furthermore, the three-dimensional vibration table includes a base and a vibration platform arranged above the base, the base supports the vibration platform through multiple rubber springs, and a horizontal vibration motor and a vertical vibration motor are installed on the vibration platform. The horizontal vibration motor is used to provide the vibration force along the horizontal direction for the vibration table, and the vertical vibration motor is used to provide the vibration force along the vertical direction for the vibration table.

[0013] Furthermore, the S4 taking out specifically includes: turning over the sand box to dump the iron shots and the coated sand shell mold outside the sand box to separate the coated sand shell mold from the iron shots, knocking and crushing the coated sand shell mold from the outside of the bearing retainer casting to obtain the bearing retainer casting, separating the iron shots and waste sand, and recovering the iron shots.

[0014] Furthermore, the sand box comprises a box body, the bottom of the box body is connected with a lifting fork mounting structure, the lifting fork mounting structure is provided with a plug hole, and the top of the box body is provided with a lifting hole.

[0015] Due to the adoption of the above technical solution, the technical effects achieved by this application include at least:

[0016] 1. The ductile iron bearing retainer casting process provided by the present application is based on the coated sand shell back shot casting process and improved, and can obtain the bearing retainer casting dimensional accuracy of CT8 or above and good bearing retainer surface roughness. Under the condition of using iron shot as back sand filling, this process improves the thermal conductivity of the bearing retainer casting and the cooling rate of the bearing retainer, and is easy to obtain a dense bearing retainer, a higher spheroidization grade and smaller graphite balls. Moreover, under the condition of using iron shot as back sand filling, the cooling rate of the casting is at least three times the cooling rate of the sand mold, but is much lower than the cooling rate of the coated sand iron mold sand casting, which is conducive to obtaining ductile iron with a cast ferrite matrix, and meets the material requirements of ductile iron bearing retainer castings.

[0017] 2. In this process, the upper shell and lower shell of the coated sand shell are consistent in structure and are made with the same shell mold, which simplifies the mold design. Only one set of matching shell molds needs to be designed for either the upper shell or the lower shell, and the upper shell and the lower shell can be manufactured by coated sand, which helps to reduce costs. It can be seen that compared with the existing iron-coated sand casting process, this process only requires one set of shell molds from beginning to end, and the upper shell and the lower shell can be manufactured by the shell mold. The upper shell and the lower shell are then connected to form a complete coated sand shell. A cavity is directly formed in the coated sand shell for the molten iron to solidify into a bearing retainer casting. After the molten iron is solidified, the coated sand shell does not need to be recovered, and the bearing retainer casting can be obtained by knocking and crushing it. Therefore, the process steps are effectively simplified, and there is no need to use mechanical equipment such as molding machines, which greatly reduces the casting cost, helps to improve production efficiency and reduce the probability of defective castings. It is highly practical and can produce large quantities of ductile iron bearing retainer castings in a short period of time.

[0018] 3. The formed upper shell mold is connected with a coated sand upper cover, and the formed lower shell mold is connected with a coated sand lower cover. The upper shell mold and the lower shell mold are connected and matched to form a complete coated sand shell mold. At the same time, the coated sand upper cover and the coated sand lower cover are connected and matched to form a pouring channel connected to the mold cavity, so that the coated sand shell mold itself provides a pouring channel for pouring molten iron into the mold cavity, so that the molten iron can enter the mold cavity with the help of the pouring channel. Compared with the additional design of a casting that is connected to the mold cavity, this design has simpler steps and lower costs, and it also helps to improve the convenience of pouring molten iron. In addition, after pouring, a certain amount of molten iron still remains in the pouring channel. This part of the molten iron can be replenished into the mold cavity when the bearing retainer is formed, which has the effect of preventing shrinkage holes, shrinkage, exhaust and slag collection. Its main function is to compensate for shrinkage.

[0019] 4. The shell mold is matched with the first movable block to synchronously form the upper shell mold and the coated sand upper cover connected together, and the shell mold is matched with the second movable block to synchronously form the lower shell mold and the coated sand lower cover connected together. The structural requirements for the coated sand upper cover and the coated sand lower cover are greatly reduced, so that the coated sand upper cover and the coated sand lower cover can adopt a consistent structure or an inconsistent structure. When the structures of the coated sand upper cover and the coated sand lower cover are consistent, the first movable block and the second movable block are also consistent in structure and have universality. When the structures of the coated sand upper cover and the coated sand lower cover are inconsistent, the structures of the first movable block and the second movable block are also inconsistent. Therefore, the first movable block and the second movable block are respectively matched with the same shell mold to form upper shell molds and lower shell molds with consistent structures and coated sand upper covers and coated sand lower covers with different structures. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The drawings described herein are used to provide a further understanding of the present application and constitute a part of the present application. The illustrative embodiments of the present application and their descriptions are used to explain the present application and do not constitute an improper limitation on the present application. In the drawings:

[0021] Figure 1 An axonometric view of the coated sand shell provided in the embodiment of the present application;

[0022] Figure 2 A cross-sectional view of the coated sand shell provided in the embodiment of the present application Figure 1 ;

[0023] Figure 3 A schematic diagram of the structure of the upper shell type and the coated sand upper cover provided in the embodiment of the present application;

[0024] Figure 4 A schematic diagram of the structure of the lower shell mold and the coated sand lower cover provided in the embodiment of the present application;

[0025] Figure 5 A cross-sectional view of the coated sand shell provided in the embodiment of the present application Figure 2;

[0026] Figure 6 This is an assembly diagram of the coated sand shell mold and the casting provided in the embodiment of the present application.

[0027] Figure 7 A schematic diagram of the structure of the casting provided in the embodiment of the present application;

[0028] Figure 8 A cross-sectional view of a casting provided in an embodiment of the present application;

[0029] Fig. 9 A schematic diagram of the structure of the sand box provided in the embodiment of the present application;

[0030] Fig.10 A front view of a three-dimensional vibration table provided in an embodiment of the present application;

[0031] Fig.11 A bottom view of the three-dimensional compaction table provided in an embodiment of the present application.

[0032] List of parts and reference numerals:

[0033] 11 upper shell mold, 12 lower shell mold, 13 mold cavity, 14 coated sand upper cover, 15 coated sand lower cover, 161 pouring inlet, 162 pouring outlet, 163 runner, 164 flow control runner, 165 riser;

[0034] 2 sand box, 21 box body, 22 lifting fork mounting structure, 23 plug hole, 24 lifting hole;

[0035] 3 casting part, 31 sprue, 32 vertical guide part, 33 horizontal connection part, 34 pouring cup;

[0036] 4 three-dimensional vibration table, 41 base, 42 vibration platform, 43 rubber spring, 44 horizontal vibration motor, 45 vertical vibration motor. DETAILED DESCRIPTION

[0037] In order to more clearly illustrate the overall concept of the present application, a detailed description is given below in an illustrative manner in conjunction with the accompanying drawings.

[0038] In the following description, many specific details are set forth to facilitate a full understanding of the present application. However, the present application may also be implemented in other ways different from those described herein. Therefore, the scope of protection of the present application is not limited to the specific embodiments disclosed below.

[0039] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0040] The present application provides a casting process for a ductile iron bearing retainer. For ease of description and understanding, the following contents provided in the present application are as follows: Figure 1 To Attachment Fig.11 Of course, those skilled in the art will appreciate that the above structure is only a specific example and schematic illustration and does not constitute a specific limitation on the technical solution provided in this application.

[0041] The present application provides a ductile iron bearing retainer casting process, comprising:

[0042] S1 Shell mold design: Pre-draw the bearing retainer model drawing and the matching coated sand shell mold model drawing using computer-aided software (such as CAD, SOLIDWORKS, etc.), wherein the coated sand shell mold includes an upper shell mold 11 and a lower shell mold 12, the upper shell mold 11 and the lower shell mold 12 enclose a mold cavity 13 that matches the contour of the bearing retainer casting, and the upper shell mold 11 and the lower shell mold 12 have the same structure and can be made using the same shell mold;

[0043] S2 Shell mold production: Cast a shell mold, configure coated sand, cover the coated sand in the shell mold, heat the shell mold to obtain an upper shell mold 11, take out the upper shell mold 11 from the shell mold, wait for the shell mold to cool, cover the coated sand in the shell mold, heat the shell mold to obtain a lower shell mold 12, and the upper shell mold 11 and the lower shell mold 12 are connected and matched to form a complete coated sand shell mold; specifically, the shell mold can be a metal mold; the configuration of the coated sand can refer to the existing technology, for example, first heat the raw sand for a few minutes and then take it out to cool, then add heat-resistant phenolic resin to mix, continue to cool and add curing agent, finally add lubricant and coupling agent and stir to obtain coated sand; the upper shell mold 11 and the lower shell mold 12 can be connected by stoppers, and can also be connected by gluing, for example, the upper shell mold 11 and the lower shell mold 12 can be connected by stoppers through concave stoppers and convex stoppers, and then fixed by gluing to form a complete coated sand shell mold;

[0044] S3 pouring: Pig iron, scrap steel and alloy materials are subjected to high-temperature melting, spheroidization and inoculation treatment to obtain molten iron, iron shots are spread on the bottom of the sand box 2 and then vibrated, the coated sand shell mold is placed on the iron shots at the bottom of the sand box 2, and iron shots are filled layer by layer from bottom to top between the inner wall of the sand box 2 and the coated sand shell mold, and each layer of iron shots is filled and vibrated before the next layer of iron shots is filled, and the molten iron is poured into the mold cavity 13 of the coated sand shell mold, and after cooling, the molten iron solidifies and forms a bearing retainer casting; specifically, pig iron, scrap steel and alloy materials can be placed in a smelting furnace for smelting treatment and adjusting the chemical composition, and the molten iron is taken out of the furnace after smelting. The molten iron taken out of the furnace is transported to the wire feeder through a spheroidizing bag for spheroidization treatment, and then inoculated by adding an inoculant, and finally cooled to a suitable temperature (such as about 1500°C) and poured into the mold cavity 13 of the coated sand shell mold;

[0045] S4 Removal: Separate the coated sand shell mold from the iron shot, and remove the coated sand shell mold from the outside of the bearing retainer casting by knocking and crushing to obtain the internally formed bearing retainer casting; the coated sand shell mold is in a slag state after being knocked and crushed, and does not need to be recycled. The obtained molded bearing retainer casting can be shot blasted and polished after cooling before quality inspection.

[0046] The ductile iron bearing retainer casting process provided by the present application is based on the coated sand shell back shot casting process and improved, and can obtain the dimensional accuracy of the bearing retainer casting above CT8 and the better surface roughness of the bearing retainer. Under the condition of using iron shot as back sand filling, the process improves the thermal conductivity of the bearing retainer casting and the cooling rate of the bearing retainer, and is easy to obtain a dense bearing retainer, a higher spheroidization grade and smaller graphite balls. Moreover, under the condition of using iron shot as back sand filling, the cooling rate of the casting is at least three times the cooling rate of the sand mold, but is much lower than the cooling rate of the coated sand iron mold sand casting, which is conducive to obtaining ductile iron with a cast ferrite matrix, and meets the material requirements of ductile iron bearing retainer castings.

[0047] In this process, the upper shell mold 11 and the lower shell mold 12 of the coated sand shell mold have the same structure and are made with the same shell mold, which saves a pair of molds and simplifies the mold design. Only one set of matching shell molds needs to be designed for one of the upper shell mold 11 and the lower shell mold 12, and the upper shell mold 11 and the lower shell mold 12 can be manufactured by coated sand, which helps to reduce costs. It can be seen that compared with the existing iron-coated sand casting process, this process only needs to design a set of shell molds from beginning to end, and the upper shell mold 11 and the lower shell mold 12 can be manufactured by the shell mold. The upper shell mold 11 and the lower shell mold 12 are then connected to form a complete coated sand shell mold, and a cavity 13 for the molten iron to solidify and form a bearing retainer casting is directly formed in the coated sand shell mold. After the molten iron is solidified and formed, the coated sand shell mold does not need to be recovered, and only needs to be knocked and crushed to obtain the bearing retainer casting. Therefore, the process steps are effectively simplified, and there is no need to use mechanical equipment such as molding machines, which greatly reduces the casting cost, helps to improve production efficiency and reduce the probability of defective castings. It is highly practical and can produce large quantities of ductile iron bearing retainer castings in a short period of time.

[0048] As a preferred embodiment, the S2 shell mold production specifically includes:

[0049] S21: Casting a shell mold, preparing coated sand, covering the coated sand in the shell mold, heating the shell mold, making an upper shell mold 11, the upper shell mold 11 is connected with a coated sand upper cover 14, taking out the upper shell mold 11 from the shell mold, and waiting for the shell mold to cool;

[0050] S22: Covering the shell mold with coated sand, heating the shell mold, and obtaining a lower shell mold 12, wherein the lower shell mold 12 is connected with a coated sand lower cover 15;

[0051] S23: the upper shell mold 11 and the lower shell mold 12 are connected and matched to form a complete coated sand shell mold, while the coated sand upper cover 14 and the coated sand lower cover 15 are connected and matched to form a pouring channel connected to the mold cavity 13.

[0052] In this embodiment, the coated sand upper cover 14 can be separately formed relative to the upper shell mold 11, and then connected to the molded upper shell mold 11. As a preferred embodiment, the coated sand upper cover 14 can be integrally formed with the upper shell mold 11 to simplify the processing technology. In other words, during the molding of the upper shell mold 11 in the shell mold, the coated sand upper cover 14 is also synchronously molded and connected to the upper shell mold 11; similarly, the coated sand lower cover 15 can be separately formed relative to the lower shell mold 12, and then connected to the molded lower shell mold 12. As a preferred embodiment, the coated sand lower cover 15 can also be integrally molded with the lower shell mold 12 to simplify the processing technology. In other words, during the molding of the lower shell mold 12 in the shell mold, the coated sand lower cover 15 is also synchronously molded and connected to the lower shell mold 12. The formed upper shell mold 11 is connected with a coated sand upper cover 14, and the formed lower shell mold 12 is connected with a coated sand lower cover 15. The upper shell mold 11 and the lower shell mold 12 are connected and matched to form a complete coated sand shell mold. At the same time, the coated sand upper cover 14 and the coated sand lower cover 15 are connected and matched to form a pouring channel connected to the mold cavity 13, so that the coated sand shell mold itself provides a pouring channel for pouring molten iron into the mold cavity 13, so that the molten iron can enter the mold cavity 13 with the help of the pouring channel. Compared with the additional design of a pouring structure that is connected to the mold cavity 13, this design has simpler steps and lower costs, and it also helps to improve the convenience of pouring molten iron. In addition, after pouring, a certain amount of molten iron still remains in the pouring channel. This part of the molten iron can be used to replenish the molten iron in the mold cavity 13 when the bearing retainer is formed, which has the effect of preventing shrinkage holes, shrinkage, exhaust and slag collection, and its main function is to compensate for shrinkage.

[0053] As a preferred embodiment, the S21 specifically includes: casting a shell mold, disposing a first movable block on one side of the shell mold, wherein the first movable block is detachably connected to the shell mold to achieve quick replacement, and a mold cavity adapted to the coated sand upper cover 14 is provided in the first movable block; configuring coated sand, covering the shell mold and the first movable block with the coated sand, heating the shell mold and the first movable block to obtain an upper shell mold 11 and a coated sand upper cover 14 connected together, taking out the upper shell mold 11 from the shell mold while separating the coated sand upper cover 14 from the first movable block, and waiting for the shell mold to cool;

[0054] The S22 specifically includes: a second movable block is arranged on one side of the shell mold, wherein the second movable block is detachably connected to the shell mold to realize quick replacement, and a mold cavity adapted to the coated sand lower cover 15 is arranged in the second movable block; the coated sand is covered in the shell mold and the second movable block, the shell mold and the second movable block are heated to obtain the lower shell mold 12 and the coated sand lower cover 15 connected together, and the coated sand lower cover 15 is separated from the second movable block while the lower shell mold 12 is taken out from the shell mold.

[0055] Regarding the detachable connection between the first movable block and the shell mold, as a simple solution, the first movable block and the shell mold can be directly abutted and connected, and the clamping mechanism can clamp the two to achieve relative fixation. Of course, other suitable solutions can also be selected, for example, detachable connection can be achieved by bolts. Similarly, regarding the detachable connection between the second movable block and the shell mold, as a simple solution, the second movable block and the shell mold can be directly abutted and connected, and the clamping mechanism can clamp the two to achieve relative fixation. Of course, other suitable solutions such as bolt connection can also be selected. Those skilled in the art can understand that, the shell mold is matched with the first movable block to synchronously form the upper shell mold 11 and the coated sand upper cover 14 connected together, and the shell mold is matched with the second movable block to synchronously form the lower shell mold 12 and the coated sand lower cover 15 connected together, and the structural requirements for the coated sand upper cover 14 and the coated sand lower cover 15 are greatly reduced, so that the coated sand upper cover 14 and the coated sand lower cover 15 can adopt a scheme with consistent structure or a scheme with inconsistent structure. When the coated sand upper cover 14 and the coated sand lower cover 15 have consistent structures, the first movable block and the second movable block are also of consistent structure and have universality. When the coated sand upper cover 14 and the coated sand lower cover 15 have inconsistent structures, the first movable block and the second movable block have inconsistent structural configurations. Therefore, the first movable block and the second movable block are respectively used in combination with the same shell mold to form an upper shell mold 11 and a lower shell mold 12 with consistent structures and a coated sand upper cover 14 and a coated sand lower cover 15 with different structures. In a preferred embodiment, the first movable block and the second movable block can adopt a metal mold consistent with the shell mold material, so that the upper shell mold 11, the lower shell mold 12, the coated sand upper cover 14 and the coated sand lower cover 15 can be manufactured using the same heating equipment and the same temperature as the shell mold.

[0056] Furthermore, if Figures 1 to 5As shown, one end of the pouring channel is provided with a pouring inlet 161, and the other end is provided with a pouring outlet 162 connected to the cavity 13. The pouring channel includes a cross runner 163, a flow control runner 164 and a riser 165 in sequence from the pouring inlet 161 toward the pouring outlet 162. The flow control runner 164 is provided with two outlet ends symmetrically arranged about the cross runner 163, and each of the outlet ends is connected to one of the risers 165. It can be understood by those skilled in the art that the runner 163 is used for molten iron to enter the pouring channel. For example, the runner 163 can be used to connect the straight runner. After the molten iron comes down from the straight runner, it enters the runner 163. After the molten iron enters the runner 163, it is divided into two streams by the controlled flow runner 164. The two streams of molten iron enter the riser 165 from the two outlet ends of the controlled flow runner 164, respectively, effectively increasing the flow area of ​​the pouring channel, thereby increasing the amount of molten iron poured into the cavity 13 per unit time, thereby further improving the pouring efficiency and production efficiency. The molten iron enters the cavity 13 through the riser 165. The inner cavity of the riser 165 will store a part of the molten iron. When the bearing retainer is formed, the molten iron can be replenished, thereby preventing shrinkage cavities, shrinkage, exhaust and slag collection. Further preferably, a plurality of pouring channels can be provided along the circumference of the coated sand shell mold, and the plurality of pouring channels can synchronously pour molten iron into the cavity 13. The more the number of pouring channels, the higher the pouring efficiency.

[0057] As a preferred embodiment, in the S3 pouring, the specific operation of pouring molten iron into the mold cavity 13 of the coated sand shell mold is as follows: connect the casting piece 3 with the sprue 31 to the pouring channel, and pour the molten iron into the mold cavity 13 of the coated sand shell mold through the sprue 31 and the pouring channel. Specifically, the casting piece 3 can be pre-connected to multiple pouring channels, and the coated sand shell mold and the casting piece 3 can be placed together on the iron shot at the bottom of the sand box 2. After the iron shot is continuously filled from bottom to top and vibrated, molten iron is poured into the mold cavity 13 through the sprue 31 and the pouring channel. The convenience of pouring molten iron can be greatly improved by the casting piece 3. Preferably, as Figure 6 As shown, the sprue 31 extends axially along the coated sand shell mold and is higher than the coated sand shell mold, so that after the iron shot is completely buried in the coated sand shell mold in the sand box 2, the upper entrance of the sprue 31 can be exposed above the iron shot, so as to facilitate molten iron to enter the sprue 31 and avoid the iron shot affecting the pouring.

[0058] Furthermore, if Figures 6 to 8As shown, the casting 3 includes a vertical guide portion 32 and a transverse connection portion 33 connected to the side of the vertical guide portion 32, the sprue 31 is formed in the vertical guide portion 32, a pouring cup 34 is provided on the top of the vertical guide portion 32, and the transverse connection portion 33 is used to connect with the inlet of the pouring channel. Preferably, the coated sand shell mold can be connected with multiple coated sand upper covers 14 and coated sand lower covers 15 along the circumferential direction, and the multiple coated sand upper covers 14 and coated sand lower covers 15 cooperate to form multiple pouring channels. Correspondingly, the casting 3 is also provided with multiple transverse connection portions 33, and the transverse connection portions 33 are connected to the pouring channels one by one. The multiple transverse connection portions 33 and the pouring channels pour molten iron into the mold cavity 13 together, which helps to improve the casting efficiency and the uniformity of the molten iron filling in the mold cavity 13, thereby reducing the defective rate of the bearing retainer casting. Preferably, the casting 3 can be made of metal material, which can be recycled and reused after a single casting.

[0059] As a preferred embodiment of the present application, the specific operation of the vibration is: placing the sand box 2 on the three-dimensional vibration table 4, and vibrating it through the three-dimensional vibration table 4. The three-dimensional vibration equipment is used in the iron shot vibration process in this process to realize automatic vibration of the iron shot, no longer requiring manual operation, improving work efficiency and reducing repairs, and using the three-dimensional vibration principle to provide vibration forces along different positions and directions for the sand box 2, thereby vibrating the iron shots inside the sand box 2, the iron shots are compacted tightly and more evenly, the vibration effect is good, and it helps to improve the quality of castings.

[0060] Furthermore, if Fig.10 and Fig.11 As shown, the three-dimensional vibration table 4 includes a base 41 and a vibration platform 42 arranged above the base 41. The base 41 supports the vibration platform 42 through a plurality of rubber springs 43. A horizontal vibration motor 44 and a vertical vibration motor 45 are installed on the vibration platform 42. The horizontal vibration motor 44 is used to provide the vibration force in the horizontal direction for the vibration platform, and the vertical vibration motor 45 is used to provide the vibration force in the vertical direction for the vibration platform. The horizontal vibration motor 44 and the vertical vibration motor 45 provide vibration forces in the horizontal direction and the vertical direction for the vibration platform 42 respectively, and the rubber spring 43 provides a buffering effect for the vibration of the vibration platform 42.

[0061] As a preferred embodiment of the present application, the S4 taking out specifically includes: turning over the sand box 2 to dump the iron shot and the coated sand shell mold outside the sand box 2, so that the coated sand shell mold is separated from the iron shot, and the coated sand shell mold is knocked and crushed from the outside of the bearing retainer casting to obtain the bearing retainer casting, and the iron shot and waste sand are separated, and the iron shot is recovered. It can be understood by those skilled in the art that, compared with the solution of manually directly taking out the iron shot and the coated sand shell mold from the sand box 2, turning over the sand box 2 to dump the iron shot and the coated sand shell mold outside the sand box 2, so that the coated sand shell mold and the iron shot can be quickly separated, which helps to reduce the workload, and the separated iron shot is recycled and reused, which can save casting costs.

[0062] Furthermore, if Fig. 9 As shown, the sand box 2 includes a box body 21, the bottom of the box body 21 is connected to a lifting fork-mounted structure 22, the lifting fork-mounted structure 22 is provided with a socket 23, and the top of the box body 21 is provided with a lifting hole 24. It can be understood by those skilled in the art that the lifting fork-mounted structure 22 is connected to the bottom of the box body 21, and the socket 23 of the lifting fork-mounted structure 22 can be adapted to the fork of a forklift, so that the sand box 2 can be lifted, moved, loaded, etc. by a forklift. For example, the sand box 2 can be lifted and placed on the vibration platform 42 or removed from the vibration platform 42 by a forklift, thereby freeing up manpower, and the forklift and the lifting fork-mounted structure 22 are plugged into each other, avoiding the forklift from directly contacting the box body 21, and effectively reducing the risk of causing deformation or even damage to the box body 21. The lifting hole 24 can be adapted to the hook of a crane, so that in the S4 picking step, the crane can hook the lifting hole 24 on one side to lift that side upward, thereby turning the sand box 2 over, and then pouring the coated sand shell mold and the iron shot out of the sand box 2 to separate them, thereby reducing the workload, saving working time and labor costs, and reducing the risk of safety accidents.

[0063] The various embodiments in this specification are described in a progressive manner, and the same or similar parts between the various embodiments can be referenced to each other, and each embodiment focuses on the differences from other embodiments.

[0064] The above is only an embodiment of the present application and is not intended to limit the present application. For those skilled in the art, the present application may have various changes and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application should be included in the scope of the claims of the present application.

Claims

1. A ductile iron bearing retainer casting process, characterized in that: include: S1 Shell mold design: Computer-aided software is used to draw the drawings of the bearing retainer model and the corresponding coated sand shell mold model in advance. The coated sand shell mold includes an upper shell mold and a lower shell mold. The upper shell mold and the lower shell mold enclose a cavity that fits the contour of the bearing retainer casting. The upper shell mold and the lower shell mold have the same structure and can be made using the same shell mold; S2 Shell mold production: casting a shell mold, preparing coated sand, covering the coated sand in the shell mold, heating the shell mold to obtain an upper shell mold, taking out the upper shell mold from the shell mold, waiting for the shell mold to cool, covering the coated sand in the shell mold, heating the shell mold to obtain a lower shell mold, and connecting the upper shell mold and the lower shell mold to form a complete coated sand shell mold; S3 pouring: Pig iron, scrap steel and alloy materials are melted at high temperature, spheroidized and inoculated to obtain molten iron, iron shots are spread on the bottom of the sand box and compacted, the coated sand shell mold is placed on the iron shots at the bottom of the sand box, iron shots are filled layer by layer from bottom to top between the inner wall of the sand box and the coated sand shell mold, each layer of iron shots is filled and compacted before the next layer of iron shots is filled, the molten iron is poured into the mold cavity of the coated sand shell mold, and after cooling, the molten iron solidifies and forms a bearing retainer casting; S4 taking out: separating the coated sand shell mold from the iron shot, knocking and crushing the coated sand shell mold from the outside of the bearing retainer casting to obtain the internally formed bearing retainer casting.

2. The casting process of ductile iron bearing retainer according to claim 1, characterized in that: The S2 shell mold production specifically includes: S21: Casting a shell mold, preparing coated sand, covering the coated sand in the shell mold, heating the shell mold to obtain an upper shell mold, the upper shell mold is connected with a coated sand upper cover, taking out the upper shell mold from the shell mold, and waiting for the shell mold to cool; S22: Covering the shell mold with coated sand, heating the shell mold, and obtaining a lower shell mold, wherein the lower shell mold is connected with a lower cover of the coated sand; S23: The upper shell mold and the lower shell mold are connected and matched to form a complete coated sand shell mold, while the coated sand upper cover and the coated sand lower cover are connected and matched to form a pouring channel connected to the mold cavity.

3. The casting process of ductile iron bearing retainer according to claim 2, characterized in that: The S21 specifically includes: casting a shell mold, disposing a first movable block on one side of the shell mold, wherein the first movable block is detachably connected to the shell mold to achieve quick replacement, and a mold cavity adapted to the coated sand upper cover is provided in the first movable block; disposing coated sand, covering the shell mold and the first movable block with the coated sand, heating the shell mold and the first movable block to obtain an upper shell mold and a coated sand upper cover connected together, taking out the upper shell mold from the shell mold while separating the coated sand upper cover from the first movable block, and waiting for the shell mold to cool; The S22 specifically includes: a second movable block is arranged on one side of the shell mold, wherein the second movable block is detachably connected to the shell mold to realize quick replacement, and a mold cavity adapted to a lower cover of coated sand is arranged in the second movable block; the coated sand is covered in the shell mold and the second movable block, the shell mold and the second movable block are heated to obtain a lower shell mold and a lower cover of coated sand connected together, and the lower shell mold is removed from the shell mold while the lower cover of coated sand is separated from the second movable block.

4. The casting process of ductile iron bearing retainer according to claim 3, characterized in that: A pouring inlet is provided at one end of the pouring channel, and a pouring outlet connected to the mold cavity is provided at the other end. The pouring channel includes a cross runner, a flow control runner and a riser in sequence from the pouring inlet toward the pouring outlet. The flow control runner is provided with two outlet ends symmetrically arranged about the cross runner, and each of the outlet ends is connected to one of the risers.

5. The casting process of ductile iron bearing retainer according to claim 2, characterized in that: In the pouring S3, the molten iron is poured into the mold cavity of the coated sand shell mold. The specific operation is: connect the pouring piece with the sprue to the pouring channel, and pour the molten iron into the mold cavity of the coated sand shell mold through the sprue and the pouring channel.

6. The casting process of ductile iron bearing retainer according to claim 5, characterized in that: The casting part includes a vertical flow guide part and a transverse connection part connected to the side of the vertical flow guide part, the straight runner is formed in the vertical flow guide part, a pouring cup is provided on the top of the vertical flow guide part, and the transverse connection part is used to connect with the inlet of the pouring channel.

7. The casting process of ductile iron bearing retainer according to claim 1, characterized in that: The specific operation of the compaction is: placing the sand box on a three-dimensional compaction table and compacting it through the three-dimensional compaction table.

8. The casting process of ductile iron bearing retainer according to claim 7, characterized in that: The three-dimensional vibration table includes a base and a vibration platform arranged above the base, the base supports the vibration platform through multiple rubber springs, and a horizontal vibration motor and a vertical vibration motor are installed on the vibration platform. The horizontal vibration motor is used to provide the vibration force along the horizontal direction for the vibration table, and the vertical vibration motor is used to provide the vibration force along the vertical direction for the vibration table.

9. The casting process of ductile iron bearing retainer according to claim 1, characterized in that: The S4 taking out specifically includes: turning over the sand box to dump the iron shots and the coated sand shell mold outside the sand box to separate the coated sand shell mold from the iron shots, knocking and crushing the coated sand shell mold from the outside of the bearing retainer casting to obtain the bearing retainer casting, separating the iron shots and waste sand, and recovering the iron shots.

10. The casting process of ductile iron bearing retainer according to claim 9, characterized in that: The sand box comprises a box body, the bottom of the box body is connected with a lifting fork mounting structure, the lifting fork mounting structure is provided with a plug hole, and the top of the box body is provided with a lifting hole.

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