A double-layer composite die-casting die barrel

Abstract

The utility model relates to a kind of double-layer composite die casting mould material cylinder, including coaxially arranged inner layer cylinder and outer layer cylinder, the outer wall of the inner layer cylinder is fixed with the interference fit of inner wall of outer layer cylinder, form double-layer composite structure, the inner wall of the inner layer cylinder is feed channel, the outer layer cylinder upper portion one side is provided with the feed inlet of communicating feed channel, the material quality of the inner layer cylinder is SKD61 hot working die steel, the material quality of the outer layer cylinder is 45 steel.The utility model material cylinder inner layer uses SKD61 hot working die steel, can directly contact high-temperature material, excellent wear resistance and thermal fatigue resistance;Material cylinder outer layer uses 45 steel, cost is only 1 / 4-1 / 3 of SKD61, through reasonable thickness design to bear structure support effect, overall cost reduces 30%-50%, while meeting high pressure working condition demand;Inner layer cylinder and outer layer cylinder between using interference fit plus sealing adhesive layer connection mode, make two layer cylinder form integral force structure, under periodic high temperature and high pressure, there is no risk of loosening.

Description

Technical Field

[0001] This utility model relates to the field of die casting mold technology, and in particular to a double-layer composite die casting mold cylinder. Background Technology

[0002] The die casting mold cylinder is the core component of the die casting machine. Its main function is to contain the material to be die-cast (such as molten metal, high-temperature plastic, etc.) and push the material into the mold cavity under high pressure to complete the molding.

[0003] Existing die-casting mold cylinders are mostly manufactured as a single piece using high-performance hot-work die steel (such as SKD61). While this meets the requirements for high temperature resistance, high pressure resistance, and wear resistance, the material cost is high (SKD61 costs approximately 3-5 times more than ordinary steel), especially for large-sized cylinders, where manufacturing costs increase significantly. If ordinary structural steel (such as 45# steel) is used, the cost is lower, but its high-temperature strength is insufficient (45# steel's strength decreases by more than 30% above 400℃), and its wear resistance is poor, making it prone to wear on the inner wall due to material erosion. During the die-casting process, the cylinder needs to withstand cyclic high temperatures. If the thickness of a single-material cylinder is designed to be too thick, the heat dissipation efficiency is low, which can easily lead to localized overheating; if the thickness is too thin, it cannot meet the structural strength requirements under high-pressure conditions, and deformation or cracking is likely to occur. Summary of the Invention

[0004] The technical problem to be solved by this utility model is to provide a double-layer composite die-casting mold cylinder. The inner layer of the cylinder is made of SKD61 hot work mold steel, which can directly contact high-temperature materials and has excellent wear resistance and thermal fatigue resistance. The outer layer of the cylinder is made of 45 steel, which costs only 1 / 4 to 1 / 3 of SKD61. Through reasonable thickness design, it undertakes the structural support function, reducing the overall cost by 30% to 50% while meeting the requirements of high-pressure conditions. The inner and outer cylinders are connected by an interference fit plus a sealing layer, so that the two cylinders form an integral load-bearing structure, which has no risk of loosening under periodic high temperature and high pressure.

[0005] The technical solution adopted by this utility model to solve its technical problem is: to provide a double-layer composite die-casting mold cylinder, including an inner cylinder and an outer cylinder arranged coaxially, wherein the outer wall of the inner cylinder and the inner wall of the outer cylinder are fixed by interference fit to form a double-layer composite structure, the inner wall of the inner cylinder is a feeding channel, and a feeding port communicating with the feeding channel is opened on one side of the upper part of the outer cylinder, wherein the material of the inner cylinder is SKD61 hot work die steel, and the material of the outer cylinder is 45 steel.

[0006] As a supplement to the technical solution described in this utility model, the thickness of the inner tube is 5-15mm, the thickness of the outer tube is 20-30mm, and the inner tube and the outer tube have the same length and their two end faces are flush.

[0007] As a supplement to the technical solution described in this utility model, the interference fit between the inner and outer cylinders is 0.02-0.05mm, and a high-temperature resistant sealing layer is provided between the mating surfaces of the two.

[0008] As a supplement to the technical solution described in this utility model, the outer cylinder is provided with at least one cooling pipe arranged around the inner cylinder. The cooling pipe includes two vertical channels and one horizontal channel. The upper end face of the outer cylinder has two vertical channels on the side of the inner cylinder. The lower outer side of the outer cylinder has a horizontal channel. The horizontal channel is used to connect the lower ends of the two vertical channels. A plug is provided at the opening of the horizontal channel.

[0009] As a supplement to the technical solution described in this utility model, the distance between the horizontal channel and the outer wall of the inner cylinder is 5-10mm.

[0010] As a supplement to the technical solution described in this utility model, the lower end of the outer tube is a post, and a positioning flange extending outward is arranged above the post on the lower part of the outer tube. A positioning cut surface is provided on the lower part of one side of the positioning flange.

[0011] As a supplement to the technical solution described in this utility model, the surface of the insertion post is provided with a nitrided hardening layer, the thickness of the nitrided hardening layer is 0.1-0.3mm, and the surface hardness is HRC50-55.

[0012] Beneficial Effects: This utility model relates to a double-layer composite die-casting mold cylinder. The inner layer of the cylinder is made of SKD61 hot-work mold steel, which can directly contact high-temperature materials and has excellent wear resistance and thermal fatigue resistance. The outer layer of the cylinder is made of 45 steel, which costs only 1 / 4 to 1 / 3 of SKD61. Through reasonable thickness design, it undertakes the structural support function, reducing the overall cost by 30%-50% while meeting the requirements of high-pressure conditions. The cooling pipes built into the outer cylinder are close to the inner cylinder, and the cooling medium can directly remove the heat transferred by the material, keeping the cylinder working temperature stable at 200-400℃ and reducing the impact of thermal deformation on die-casting accuracy. The combination design of the positioning flange and the positioning tangent can achieve precise axial and circumferential positioning of the cylinder, ensuring a stable material pushing path and improving the dimensional consistency of die-cast products. The inner and outer cylinders are connected by an interference fit plus a sealing layer, so that the two cylinders form an integral load-bearing structure, eliminating the risk of loosening under periodic high temperature and high pressure. Attached Figure Description

[0013] Figure 1 This is a schematic diagram of the structure of this utility model;

[0014] Figure 2 This is a cross-sectional view of the cooling pipeline of this utility model.

[0015] Diagram: 1. Inner cylinder, 2. Outer cylinder, 3. Feed channel, 4. Feed inlet, 5. Vertical channel, 6. Plug, 7. Positioning flange, 8. Positioning section, 9. Horizontal channel, 10. Insert post. Detailed Implementation

[0016] The present invention will be further illustrated below with reference to specific embodiments. It should be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of the present invention. Furthermore, it should be understood that after reading the teachings of this invention, those skilled in the art can make various alterations or modifications to the present invention, and these equivalent forms also fall within the scope defined by the appended claims.

[0017] The embodiments of this utility model relate to a double-layer composite die-casting mold cylinder, such as... Figure 1-2 As shown, it includes an inner cylinder 1 and an outer cylinder 2 arranged coaxially. The outer wall of the inner cylinder 1 and the inner wall of the outer cylinder 2 are fixed by interference fit to form a double-layer composite structure. The inner wall of the inner cylinder 1 is a feeding channel 3. The upper side of the outer cylinder 2 is provided with a feeding port 4 that communicates with the feeding channel 3. The inner cylinder 1 is made of SKD61 hot work die steel, and the outer cylinder 2 is made of 45 steel.

[0018] The inner cylinder 1 has a thickness of 5-15mm, and the outer cylinder 2 has a thickness of 20-30mm. The inner cylinder 1 and the outer cylinder 2 have the same length and their two end faces are flush. This thickness design ensures that the inner cylinder 1 has sufficient strength to resist material erosion, and the thickness of the outer cylinder 2 supports the overall structure while avoiding material waste.

[0019] The interference fit between the inner cylinder 1 and the outer cylinder 2 is 0.02-0.05mm, and a high-temperature resistant sealant layer is provided between the mating surfaces of the two. The interference fit ensures that the two cylinders do not slide relative to each other under high temperature and high pressure. The sealant layer uses silicone-based high-temperature resistant sealant (temperature resistance ≥300℃), which can prevent material leakage from the mating surfaces and reduce heat loss through the gap.

[0020] The outer cylinder 2 is provided with at least one cooling pipe arranged around the inner cylinder 1. The cooling pipe includes two vertical channels 5 and one horizontal channel 9. The upper end face of the outer cylinder 2 is provided with two vertical channels 5 on the side of the inner cylinder 1. The lower outer side of the outer cylinder 2 is provided with a horizontal channel 9. The horizontal channel 9 is used to connect the lower ends of the two vertical channels 5. A plug 6 is provided at the opening of the horizontal channel 9. The cooling pipe can quickly remove the heat transferred by the inner cylinder 1 by passing cooling water through it, so as to avoid the cylinder from overheating.

[0021] The distance between the horizontal channel 9 and the outer wall of the inner cylinder 1 is 5-10mm. This distance design can ensure the heat exchange efficiency between the cooling medium and the inner cylinder 1, while avoiding the weakening of the strength of the outer cylinder 2 due to the channels being too close.

[0022] The inner cylinder 1 of this invention is made of SKD61 hot work die steel through forging and grinding, with a thickness of 10mm and an inner wall roughness Ra≤0.8μm to ensure smooth material flow. The outer cylinder 2 is made of 45# steel through rolling and drilling, with a thickness of 25mm. The length of the outer cylinder 2 is the same as that of the inner cylinder 1, and both end faces are flush. The mating surfaces of the inner cylinder 1 and the outer cylinder 2 adopt an interference fit with an interference amount of 0.03mm. During assembly, the outer cylinder 2 is first heated to 250℃, and then the inner cylinder 1 is pressed in. After cooling, the two layers are tightly bonded, and high-temperature resistant silicone sealant is applied between the mating surfaces to prevent material leakage.

[0023] The outer cylinder 2 has a feed inlet 4 on one side of its upper part. The feed inlet 4 is connected to the feed channel 3 of the inner cylinder 1 and is used for injecting molten metal (i.e., material). The outer cylinder 2 is equipped with a cooling pipe, which includes two vertical channels 5 (12 mm in diameter) and one horizontal channel 9 (12 mm in diameter). The vertical channels 5 are opened along the axial direction of the outer cylinder 2 and are connected to the horizontal channel 9 at their lower ends. The opening of the horizontal channel 9 is sealed by an M16 copper plug 6. The cooling medium flows in from one vertical channel 5 and flows out from the other vertical channel 5 through the horizontal channel 9, thus achieving circulating heat dissipation.

[0024] The lower end of the outer cylinder 2 is a post 10. A positioning flange 7 extending outward is arranged above the post 10 on the lower part of the outer cylinder 2. A positioning cut surface 8 is provided on the lower part of one side of the positioning flange 7. The post 10 is used to be inserted into the die-casting mold. The positioning flange 7 can limit the axial displacement of the cylinder. The positioning cut surface 8 cooperates with the mounting hole of the die-casting mold to ensure the circumferential positioning accuracy of the cylinder during installation.

[0025] The surface of the insert 10 is subjected to gas nitriding treatment to form a 0.2mm thick nitrided hardening layer; the thickness of the nitrided hardening layer is 0.1-0.3mm, and the surface hardness is HRC50-55; the nitriding treatment can significantly improve the wear resistance and anti-galling of the insert 10, and avoid wear on the mating surface caused by long-term insertion and removal.

[0026] The double-layer composite die-casting mold cylinder of this embodiment was tested under aluminum alloy die-casting conditions. After 50,000 continuous operations, the wear of the inner wall of the inner cylinder 1 was ≤0.02mm, and the positioning accuracy remained within 0.03mm. Compared with the integral SKD61 cylinder of the same size, the cost was reduced by 42%, which has significant practical value.

[0027] In the description of this utility model, it should be understood that the directional terms such as "front, back, up, down, left, right", "horizontal, vertical, horizontal" and "top, bottom" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description. Unless otherwise stated, these directional terms do not indicate or imply that the device or element referred to must have a specific orientation or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on the scope of protection of this utility model. The directional terms "inner" and "outer" refer to the inner and outer contours of each component itself.

[0028] For ease of description, spatial relative terms such as "above," "on top of," "on the upper surface of," "above," etc., are used herein to describe the spatial positional relationship of a device or feature as shown in the figures to other devices or features. It should be understood that spatial relative terms are intended to encompass different orientations in use or operation beyond the orientation of the device as described in the figures. For example, if the device in the figures were inverted, a device described as "above" or "on top of" other devices or structures would subsequently be positioned as "below" or "under" other devices or structures. Thus, the exemplary term "above" can include both "above" and "below." The device may also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatial relative descriptions used herein will be interpreted accordingly.

[0029] Furthermore, it should be noted that the use of terms such as "first" and "second" to define components is merely for the purpose of distinguishing the corresponding components. Unless otherwise stated, the above terms have no special meaning and therefore cannot be construed as limiting the scope of protection of this utility model.

[0030] The above provides a detailed description of a double-layer composite die-casting mold cylinder provided in this application. Specific examples have been used to illustrate the principles and implementation methods of this application. The description of the above embodiments is only for the purpose of helping to understand the method and core ideas of this application. At the same time, for those skilled in the art, there will be changes in the specific implementation methods and application scope based on the ideas of this application. Therefore, the content of this specification should not be construed as a limitation of this application.

Claims

1. A double-layer composite die-casting mold cylinder, characterized in that: The device includes an inner cylinder (1) and an outer cylinder (2) arranged coaxially. The outer wall of the inner cylinder (1) and the inner wall of the outer cylinder (2) are fixed by interference fit to form a double-layer composite structure. The inner wall of the inner cylinder (1) is a feeding channel (3). The upper side of the outer cylinder (2) is provided with a feeding port (4) that connects to the feeding channel (3). The inner cylinder (1) is made of SKD61 hot work die steel, and the outer cylinder (2) is made of No. 45 steel.

2. The double-layer composite die-casting mold cylinder according to claim 1, characterized in that: The inner cylinder (1) has a thickness of 5-15mm, the outer cylinder (2) has a thickness of 20-30mm, and the inner cylinder (1) and the outer cylinder (2) have the same length and their two end faces are flush.

3. The double-layer composite die-casting mold cylinder according to claim 1, characterized in that: The interference fit between the inner cylinder (1) and the outer cylinder (2) is 0.02-0.05 mm, and a high-temperature resistant sealant layer is provided between the mating surfaces of the two.

4. The double-layer composite die-casting mold cylinder according to claim 1, characterized in that: The outer cylinder (2) is provided with at least one cooling pipe arranged around the inner cylinder (1). The cooling pipe includes two vertical channels (5) and one horizontal channel (9). The upper end face of the outer cylinder (2) is located on the side of the inner cylinder (1) and two vertical channels (5) are opened. The lower outer side of the outer cylinder (2) is provided with a horizontal channel (9). The horizontal channel (9) is used to connect the lower ends of the two vertical channels (5). A plug (6) is provided at the opening of the horizontal channel (9).

5. The double-layer composite die-casting mold cylinder according to claim 4, characterized in that: The distance between the horizontal channel (9) and the outer wall of the inner cylinder (1) is 5-10 mm.

6. The double-layer composite die-casting mold cylinder according to claim 1, characterized in that: The lower end of the outer tube (2) is a post (10). A positioning flange (7) extending outward is arranged above the post (10) at the lower part of the outer tube (2). A positioning cut surface (8) is provided on the lower part of one side of the positioning flange (7).

7. The double-layer composite die-casting mold cylinder according to claim 6, characterized in that: The surface of the insert (10) is provided with a nitrided hardening layer, the thickness of which is 0.1-0.3 mm and the surface hardness is HRC50-55.

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