Planet carrier shell core preparation mold and preparation process thereof

Abstract

The invention discloses a planet carrier shell core preparation mold and a preparation process thereof, and belongs to the technical field of casting. The preparation mold comprises a core box, the core box is composed of two split molds, a sand pouring opening is formed in the position, located in the middle of a connecting line of the two split molds, of the upper end face of the core box, and a sand shooting opening is formed in each of the two sides of the sand pouring opening; a cavity for forming a planet carrier shell core is formed in the inner side surface of the split mold and is communicated with the sand shooting opening through a sand shooting channel formed in the inner side surface of the split mold. The shell core for planet carrier casting can be prepared, and compared with a traditional solid sand core, the production cost is obviously increased, and the production efficiency is obviously improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of casting, and more specifically, relates to a planet carrier shell core preparation mold and a preparation process thereof. Background Art

[0002] With the rapid development of science and technology and the manufacturing industry, the demand for castings is also increasing. This is particularly true in the automotive, aerospace, engineering machinery, oil and gas, and other fields, where demand for high-quality, high-precision castings is particularly strong. Furthermore, the rise of emerging markets such as new energy vehicles and smart devices has created new growth opportunities for the foundry industry. At the same time, the foundry industry also faces numerous challenges during its development.

[0003] Planetary carriers are a common transmission device, widely used in automobile gearboxes. Due to their complex internal structure, sand cores are usually required during the casting process to form the inner cavity of the planetary carrier.

[0004] For example, the patent document with Chinese patent application number: CN202310411154.9 and publication date: July 28, 2023 discloses a planetary carrier casting system structure and casting method. The planetary carrier casting system includes: a planetary carrier mold, a riser and a gate. The planetary carrier mold includes a main structure and an annular plate with a center hole. The main structure includes a cone, a frustum and a plurality of columns connected in sequence from top to bottom. The riser includes: an open riser and a hidden riser. The open riser is arranged at the upper end of the cone. The hidden riser corresponds one-to-one with the column and is connected to the connecting end surface of the column and the annular plate; the gate has a first port and a second port located at its upper end. The first port is respectively connected to the plurality of hidden risers, and the second port is connected to the open riser; it also includes: a first sand core and a second sand core, the first sand core is adapted in a cavity defined by the plurality of columns, and the second sand core is adapted in the center hole of the annular plate; wherein the connecting end surface between the column and the annular plate is a parting surface.

[0005] Another example is the Chinese patent application number CN202311282899.6, published on January 16, 2024, which discloses a vertical line planetary carrier sand casting process, belonging to the field of sand casting technology. A vertical line planetary carrier sand casting process of the present invention includes the following steps: S1, mold making and sand matching; S2, placing the mold in a sand box, and then filling the box with molding sand to full to form a casting; S3, setting the gate, riser, water inlet, and closing the box; S4, heating the sand box; S5, injecting molten iron into the sand mold, and after it solidifies to form a casting, performing sand removal and shot blasting; S6, inspection and storage.

[0006] Both of the above-mentioned methods utilize sand cores to create planetary carriers. However, traditional sand cores are typically solid. Solid cores are associated with heavy weight, high cost, and lengthy production times. Therefore, to enhance manufacturing capabilities and strengthen market competitiveness, shell cores have emerged. Shell cores are hollow sand cores in which the core sand rapidly hardens upon contact with the core box, forming a shell layer of a certain thickness. The unhardened core sand can then be poured out of the core box. Shell cores are rarely used in existing planetary carrier casting processes, and consequently, relatively comprehensive molds and processes for producing planetary carrier shell cores are lacking. Summary of the Invention

[0007] 1. Problems to be solved

[0008] In response to the problem that the current planetary carrier casting process lacks molds and processes for preparing shell cores for planetary carrier casting, the present invention provides a planetary carrier shell core preparation mold and its preparation process, which can prepare shell cores for planetary carrier casting. Compared with traditional solid sand cores, the production cost and production efficiency are significantly improved.

[0009] 2. Technical solution

[0010] To solve the above problems, the present invention adopts the following technical solutions.

[0011] A planetary carrier shell core preparation mold includes a core box, which is composed of two parting molds. The upper end surface of the core box is located in the middle of the connecting line of the two parting molds and is provided with a sand pouring port. A sand shooting port is provided on each side of the sand pouring port; a cavity for forming the planetary carrier shell core is placed on the inner side surface of the parting mold, and the cavity is connected to the sand shooting port through a sand shooting channel provided on the inner side surface of the parting mold.

[0012] As a further improvement of the technical solution, a positioning pin hole for closing the mold is opened on the inner side surface of the split mold.

[0013] As a further improvement of the technical solution, an exhaust hole is provided on the inner side surface of the split mold.

[0014] As a further improvement of the technical solution, a heating through hole extending along the length direction of the core box is opened, and a heating tube is placed in the heating through hole.

[0015] As a further improvement of the technical solution, the upper end surface of the core box is connected to a sand shooting plate, and a sand shooting hole is opened on the sand shooting plate at a position corresponding to the sand shooting port.

[0016] As a further improvement of the technical solution, the core box is provided with a guide hole extending into the interior of the core box along its width direction, and a cover plate is provided on the side of the core box, and a push rod extending into the guide hole is installed on the cover plate.

[0017] As a further improvement of the technical solution, there are multiple push rods, which are distributed at intervals on the cover plate.

[0018] As a further improvement of the technical solution, mold feet matching the mounting structure of the core shooter are fixedly mounted on the four corners of the core box.

[0019] As a further improvement of the technical solution, a sealing plate is fixedly installed between a pair of mold feet on both sides of the cover plate, and the sealing plate is fixedly connected to the cover plate.

[0020] A process for preparing a planetary carrier shell core comprises the following steps: after the core box is mounted on a core shooting machine, it is first heated to 220-260°C, then crusted for 35-45 seconds, and when the outer layer of sand solidifies but the inner layer of sand has not yet solidified, the sand is turned over and vibrated for 8-12 seconds to pour out the unsolidified inner layer of sand, and finally solidified for 75-85 seconds to complete the shell core production.

[0021] 3. Beneficial effects

[0022] Compared with the prior art, the present invention has the following beneficial effects:

[0023] (1) The present invention provides a planetary carrier shell core preparation mold, which is provided with a sand pouring port in the middle of two parting connection lines. When the sand pouring port is used to inject sand into the mold cavity, the inner and outer layers of sand in the mold cavity solidify first, and the inner layer of sand solidifies later. When the outer layer of sand solidifies but the inner layer of sand has not yet solidified, the core box is turned over and the sand is poured out by vibration, so that the inner layer of sand flows out from the sand pouring port. After solidification for a period of time, a hollow planetary carrier casting shell core can be prepared. Compared with the traditional solid sand core, the weight of a single shell core is reduced by 38%, which makes it more convenient for employees to use, saves the raw materials of the coated sand, and greatly reduces the cost. At the same time, the time required for the production of a single shell core is also greatly reduced compared with the solid core, and the production efficiency of the sand core is improved.

[0024] (2) A planetary carrier shell core preparation mold of the present invention has a positioning pin hole and an exhaust hole on the inner side surface of the split mold. The positioning pin hole makes the two split molds more convenient and accurate to close the mold, while the exhaust hole can discharge the gas in the mold cavity during the preparation of the shell core, thereby ensuring the quality of the shell core;

[0025] (3) The present invention provides a planetary carrier shell core preparation mold, wherein a core box is provided with a push rod along its length direction, which can eject the shell core after the shell core preparation is completed, thereby achieving smooth separation of the shell core;

[0026] (4) The planetary carrier shell core preparation mold of the present invention provides a sand-shooting plate and a mold foot, so that the core box can be quickly and conveniently connected to the core-shooting machine, thereby improving production efficiency;

[0027] (5) The present invention provides a planetary carrier shell core preparation process, which uses the above-mentioned planetary carrier shell core preparation mold to reduce the production cost of the planetary carrier sand core and improve production efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 This is a schematic diagram of the overall structure of the mold for preparing the planetary carrier shell core of the present invention;

[0029] Figure 2 This is a schematic diagram of the internal structure of the planet carrier shell core preparation mold without a cavity according to the present invention;

[0030] Figure 3 A schematic structural diagram of the cavity of a mold for preparing a planetary carrier shell core according to the present invention;

[0031] In the figure: 1. Core box; 2. Sand pouring port; 3. Sand shooting port; 4. Cavity; 5. Sand shooting channel; 6. Positioning pin hole; 7. Heating through hole; 8. Sand shooting plate; 9. Cover plate; 10. Ejector pin; 11. Exhaust hole; 12. Mold foot; 13. Closing plate. DETAILED DESCRIPTION

[0032] Exemplary embodiments of the present invention are described in detail below. Although these exemplary embodiments are described in sufficient detail to enable those skilled in the art to practice the invention, it should be understood that other embodiments may be implemented and that various changes may be made to the invention without departing from the spirit and scope of the invention. The following more detailed description of the embodiments of the invention is not intended to limit the scope of the claimed invention, but is merely for illustrative and non-limiting purposes, to describe the features and characteristics of the invention, to set forth the best mode for carrying out the invention, and to enable those skilled in the art to practice the invention. Therefore, the scope of the invention is limited solely by the appended claims.

[0033] Example 1

[0034] A planetary carrier shell core preparation mold is used to prepare a shell core for casting a planetary carrier. Its specific structure and technical effects are described in detail below.

[0035] like Figure 1 and Figure 2 As shown, the preparation mold includes a core box 1, which is composed of two split molds. The upper end surface of the core box 1 is located in the middle of the connecting line between the two split molds and is provided with a sand pouring port 2. A sand shooting port 3 is provided on each side of the sand pouring port 2. The inner side surface of the split mold is provided with a cavity 4 for forming the planetary carrier shell core. The sand pouring port 2 is the top portion of the cavity 4, exposed on the upper end surface of the core box 1. The cavity 4 is connected to the sand shooting port 3 through a sand shooting channel 5 provided on the inner side surface of the split mold.

[0036] On the inner side of the split mold, there is a positioning pin hole 6 for closing the mold, so that the two split molds can be conveniently and accurately closed by the positioning pin. At the same time, there is also an exhaust hole 11 on the inner side of the split mold, which can discharge the gas in the mold cavity during the preparation of the shell core to ensure the quality of the shell core. The core box 1 is provided with a heating through hole 7 extending along its length. A heating tube is placed in the heating through hole 7, which can be used for heating when preparing the shell core. The upper end face of the core box 1 is connected to the sand shooting plate 8, and a sand shooting hole is provided on the sand shooting plate 8 at a position corresponding to the sand shooting port 3.

[0037] In addition, the core box 1 is provided with a guide hole extending into the interior of the core box 1 along its width direction. A cover plate 9 is provided on the side of the core box 1, and a push rod 10 is installed on the cover plate 9 to extend into the guide hole. There are multiple push rods 10, which are distributed at intervals on the cover plate 9. Die feet 12 that match the mounting structure of the core shooter are fixedly installed at the four corners of the core box 1. A sealing plate 13 is fixedly installed between a pair of die feet 12 on both sides of the cover plate 9, and the sealing plate 13 is fixedly connected to the cover plate 9. By providing the sand shooting plate 8 and the die feet 12, the core box can be quickly and conveniently connected to the core shooter, thereby improving production efficiency. The ejector 10 can eject the shell core after the shell core is prepared, thereby achieving smooth separation of the shell core.

[0038] To prepare a shell core, first install the core box 1 on the core shooter. The heating tube is then heated to 220-260°C. The coated sand is ejected from the sand shooting plate 8 through the sand shooting channel 5 into the mold cavity 4. The gas inside the mold cavity 4 is exhausted through the exhaust channel 11. When the outer layer of sand solidifies but the inner layer has not yet solidified, the sand is turned over and vibrated for 8-12 seconds to discard the unsolidified inner layer of sand. Finally, the shell core is cured for 75-85 seconds, completing the shell core production.

[0039] To sum up, a planetary carrier shell core preparation mold and its preparation process of this embodiment are provided by setting a sand pouring port in the middle of the two parting connection lines. After the sand shooting port shoots sand into the mold cavity, the inner and outer layers of sand in the mold cavity will solidify first, and the inner layer of sand will solidify later. When the outer layer of sand solidifies and the inner layer of sand has not yet solidified, the core box is turned over and the sand is vibrated to pour out, so that the inner layer of sand flows out from the sand pouring port. After solidification for a period of time, a hollow planetary carrier shell core for casting can be prepared. Compared with traditional solid sand cores, the weight of a single shell core is reduced by 38%, which is more convenient for employees to use, and saves the raw materials of coated sand, which greatly reduces the cost. At the same time, the time required for the production of a single shell core is also greatly reduced compared with the solid core, and the production efficiency of the sand core is improved.

[0040] The examples described in the present invention are merely descriptions of the preferred embodiments of the present invention and are not intended to limit the concept and scope of the present invention. Without departing from the design concept of the present invention, various modifications and improvements made to the technical solutions of the present invention by engineers and technicians in this field should fall within the scope of protection of the present invention.

Claims

1. A planet carrier shell core preparation mold, characterized in that: The core box (1) comprises two split molds, the upper end surface of which is located in the middle of the connection line between the two split molds and is provided with a sand pouring port (2), and a sand shooting port (3) is provided on both sides of the sand pouring port (2); a cavity (4) for forming a planetary carrier shell core is placed on the inner side surface of the split mold, and the cavity (4) is connected to the sand shooting port (3) through a sand shooting channel (5) provided on the inner side surface of the split mold.

2. A planet carrier shell core preparation mold according to claim 1, characterized in that: A positioning pin hole (6) for closing the mold is provided on the inner side surface of the split mold.

3. A planet carrier shell core preparation mold according to claim 1, characterized in that: An exhaust hole (11) is provided on the inner side surface of the split mold.

4. A planet carrier shell core preparation mold according to claim 1, characterized in that: The core box (1) is provided with a heating through hole (7) extending along its length direction, and a heating tube is placed in the heating through hole (7).

5. A planet carrier shell core preparation mold according to claim 1, characterized in that: The upper end surface of the core box (1) is connected to a sand shooting plate (8), and a sand shooting hole is provided on the sand shooting plate (8) at a position corresponding to the sand shooting port (3).

6. A planet carrier shell core preparation mold according to claim 1, characterized in that: The core box (1) is provided with a guide hole extending along its width direction to the inside of the core box (1), a cover plate (9) is provided on the side of the core box (1), and a push rod (10) extending into the guide hole is installed on the cover plate (9).

7. A planet carrier shell core preparation mold according to claim 6, characterized in that: There are a plurality of push rods (10), which are distributed on the cover plate (9) at intervals.

8. A planet carrier shell core preparation mold according to claim 7, characterized in that: The four corners of the core box (1) are fixedly mounted with mold feet (12) that match the mounting structure of the core shooting machine.

9. A planet carrier shell core preparation mold according to claim 8, characterized in that: A sealing plate (13) is fixedly installed between a pair of mold feet (12) on both sides of the cover plate (9), and the sealing plate (13) is fixedly connected to the cover plate (9).

10. A process for preparing a planet carrier shell core, characterized in that: The following steps are involved: After the core box (1) described in any one of claims 1 to 9 is installed on the core shooting machine, it is first heated to 220-260°C, and then crusted for 35-45 seconds. When the outer sand is solidified but the inner sand has not yet solidified, the sand is poured out by turning and vibrating for 8-12 seconds, and the unsolidified inner sand is poured out. Finally, it is cured for 75-85 seconds to complete the shell core production.

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