Cooling inserts and low-pressure aluminum subframe molds

Abstract

This utility model relates to the field of mold technology, specifically a cooling insert and a low-pressure aluminum subframe mold. The insert includes a body with cooling holes at its top, connected to cooling water pipes. A long, thin heat-insulating groove runs vertically through the insert body. The cooling holes are located on one side of the heat-insulating groove. The width of the heat-insulating groove is 0.2-1.2 mm, and its length is 1 / 2-4 / 5 of the minimum outer diameter of the insert body. The heat-insulating groove is arc-shaped, and a positioning hole is located at the top of the insert body. This utility model's cooling insert, by setting the heat-insulating groove, forms a heat-insulating layer at the groove, establishing a thermal resistance barrier and creating a stepped temperature field, reducing the effective thermal conductivity cross-sectional area by 40%-60%. By controlling the length and width of the heat-insulating groove, both the heat insulation effect and the overall strength of the cooling insert can be maintained. Compared to solutions involving adding cooling water channels or using low thermal conductivity materials, this utility model's cooling insert has a lower cost.

Description

Technical Field

[0001] This utility model relates to the field of mold technology, specifically a cooling insert and a low-pressure aluminum subframe mold. Background Technology

[0002] During the casting of low-pressure aluminum subframes, rapid heat conduction between the mold inserts and the mold body leads to uneven local cooling, which can easily cause problems such as shrinkage porosity and hot cracks in the casting. Traditional solutions include adding cooling water channels or using low thermal conductivity materials, but these solutions have drawbacks such as high processing costs and reduced structural strength. They also have problems such as small mold temperature gradients and inability to effectively guide the sequential solidification of molten aluminum. Utility Model Content

[0003] The main purpose of this utility model is to provide a cooling insert and a low-pressure aluminum subframe mold to solve the problems of high cost and low structural strength of the cooling insert and small temperature gradient of the low-pressure aluminum subframe mold, which cannot effectively guide the sequential solidification of aluminum liquid in the above-mentioned prior art.

[0004] To achieve the above objectives, this utility model provides a cooling insert, including an insert body, a cooling hole at the top of the insert body, and a cooling water pipe connected to the cooling hole; a slender heat insulation groove running through the insert body from top to bottom is provided inside the insert body; the cooling hole is located on one side of the heat insulation groove.

[0005] Furthermore, the width of the heat insulation groove is 0.2-1.2mm; the length is 1 / 2-4 / 5 of the minimum outer diameter of the insert body.

[0006] Furthermore, the heat insulation groove is arc-shaped.

[0007] Furthermore, the top of the insert body is provided with positioning holes.

[0008] Furthermore, the cooling water pipe includes an outer pipe and an inner pipe; the outer pipe is sealed and fixedly connected to the inside of the cooling hole, the inner pipe is located inside the outer pipe, and there is a gap between the inner pipe and the outer pipe; there is a gap between the bottom end of the inner pipe and the bottom end of the cooling hole.

[0009] Furthermore, the bottom of the insert body is conical.

[0010] Furthermore, the insert body is made of H13 mold steel.

[0011] Furthermore, the insulation groove is filled with nano-aerogel insulation sheets.

[0012] This utility model also provides a low-pressure aluminum subframe mold, including a mold body, a mounting hole on the mold body, and the aforementioned cooling insert fixedly connected in the mounting hole.

[0013] The cooling insert of this invention forms a heat insulation layer at the heat insulation groove, establishes a thermal resistance barrier, and creates a stepped temperature field, reducing the effective heat conduction cross-sectional area by 40%-60%. By controlling the length and width of the heat insulation groove, both the heat insulation effect and the overall strength of the cooling insert can be maintained. Compared with solutions that add cooling water channels or use low thermal conductivity materials, the cooling insert of this invention has a lower cost.

[0014] The low-pressure aluminum subframe mold of this invention uses a stepped temperature gradient established by cooling inserts to force the molten aluminum to solidify sequentially from the thickest part of the casting towards the gate, thereby extending the liquid metal feeding channel by 40%-50% and completely eliminating the end shrinkage defects caused by traditional free solidification. Attached Figure Description

[0015] The accompanying drawings, which form part of this application, are used to provide a further understanding of the present invention. The illustrative embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention.

[0016] Figure 1 This is a schematic diagram of the cooling insert structure in the embodiment;

[0017] Figure 2 This is a cross-sectional view of the cooling insert in the embodiment;

[0018] Figure 3 This is a schematic diagram of the low-pressure aluminum subframe mold in the embodiment;

[0019] In the figure: 1. Insert body; 101. Cooling hole; 102. Heat insulation groove; 103. Positioning hole; 2. Outer tube; 3. Inner tube; 4. Mold body; 401. Mounting hole. Detailed Implementation

[0020] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0021] like Figures 1 to 2 As shown, according to an embodiment of the present invention, a cooling insert is provided, including an insert body 1. The top of the insert body 1 is provided with a cooling hole 101 and three positioning holes 103. The cooling hole 101 is connected to a cooling water pipe. The insert body 1 is provided with a slender heat insulation groove 102 that runs through it from top to bottom. The cooling hole 101 is located on one side of the heat insulation groove 102.

[0022] The upper part of the insert body 1 is cylindrical and the bottom is conical; the diameter of the bottommost part of the insert body 1 is 78.5mm; the conical shape is to provide a draft angle to facilitate the demolding of the casting.

[0023] The insert body 1 is made of H13 mold steel with a thermal conductivity of 24-28 W / m·K.

[0024] The heat insulation groove 102 is arc-shaped; the width of the heat insulation groove 102 is 0.2mm and the length is 51.6mm.

[0025] The cooling water pipe includes an outer pipe 2 and an inner pipe 3; the outer pipe 2 is sealed and fixedly connected to the interior of the cooling hole 101, the inner pipe 3 is located inside the outer pipe 2, and a gap is provided between the inner pipe 3 and the outer pipe 2; a gap is provided between the bottom end of the inner pipe 3 and the bottom end of the cooling hole 101; as shown Figure 2 As shown in the figure, the arrows indicate the direction of cooling water flow; cooling water enters from the inner pipe 3 and exits from the gap between the inner pipe 3 and the outer pipe 2; the heat insulation groove divides the block body 1 into left and right parts, reducing heat transfer between the left and right parts; the right part starts water cooling circulation, the temperature of the right part decreases, but does not affect the temperature field of the left part; thus forming two stepped temperature fields with different temperatures inside the cooling block.

[0026] In some embodiments, the heat insulation groove 102 is filled with a nano-aerogel heat insulation sheet.

[0027] This embodiment also provides a low-pressure aluminum subframe mold, such as Figure 3 As shown, the mold includes a mold body 4, which has a mounting hole 401. The aforementioned cooling insert is fixedly connected in the mounting hole 401. A positioning pin connected to the positioning hole 103 is provided in the mounting hole 401.

[0028] The drawbacks of existing methods for insulating cooling inserts:

[0029] Si3N4 ceramic inserts, priced at over $800 / kg, have low thermal conductivity of less than 15 W / m·K, but are brittle and have a fracture toughness of less than 6 MPa·m¹ / ², making them unable to withstand the periodic mechanical impact of low-pressure casting.

[0030] Mechanically spliced ​​thermal insulation blocks develop micron-level gaps larger than 50μm under long-term thermal stress, leading to heat leakage and dimensional deviation.

[0031] Traditional sprayed heat insulation layers are prone to cracking and peeling under high-temperature cycling at temperatures above 600°C, contaminating the molten aluminum and reducing mold life.

[0032] Modifying a water-cooling system by adding cooling water channels requires an increase of 15%-20% in mold manufacturing costs and reduces the strength of the cooling inserts.

[0033] The cooling insert in this embodiment forms a thermal insulation layer by setting a heat insulation groove, thus establishing a thermal resistance barrier and creating two stepped temperature fields with different temperatures within the cooling insert, reducing the effective heat conduction cross-sectional area by 40%-60%. By controlling the length and width of the heat insulation groove, both the heat insulation effect and the overall strength of the cooling insert can be maintained. Compared with solutions that add cooling water channels or use low thermal conductivity materials, the cooling insert in this embodiment has a lower cost.

[0034] In this embodiment, the low-pressure aluminum subframe mold uses a stepped temperature gradient established by the cooling insert to force the molten aluminum to solidify sequentially from the thickest part of the casting towards the gate, extending the liquid metal feeding channel by 40%-50% and completely eliminating the end shrinkage defects caused by traditional free solidification. Furthermore, the thermal stress during the solidification process of the molten aluminum is reduced, the shrinkage rate of the casting decreases, and the yield rate of the casting area corresponding to the cooling insert increases from the original 75% to 100%.

[0035] The above description is merely a preferred embodiment of this utility model and is not intended to limit the utility model. Various modifications and variations can be made to this utility model by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this utility model should be included within the protection scope of this utility model.

Claims

1. A cooling insert, comprising an insert body (1), characterized in that, The top of the insert body (1) is provided with a cooling hole (101), and the cooling hole (101) is connected to a cooling water pipe; the insert body (1) is provided with a slender heat insulation groove (102) running through it from top to bottom; the cooling hole (101) is located on one side of the heat insulation groove (102).

2. The cooling insert as described in claim 1, characterized in that, The width of the heat insulation groove (102) is 0.2-1.2 mm; the length is 1 / 2-4 / 5 of the minimum outer diameter of the insert body (1).

3. The cooling insert as described in claim 2, characterized in that, The heat insulation groove (102) is arc-shaped.

4. The cooling insert as described in claim 1, characterized in that, The top of the insert body (1) is provided with a positioning hole (103).

5. The cooling insert as described in claim 1, characterized in that, The cooling water pipe includes an outer pipe (2) and an inner pipe (3); the outer pipe (2) is sealed and fixedly connected to the inside of the cooling hole (101), the inner pipe (3) is located inside the outer pipe (2), and there is a gap between the inner pipe (3) and the outer pipe (2); there is a gap between the bottom end of the inner pipe (3) and the bottom end of the cooling hole (101).

6. The cooling insert as claimed in claim 1, characterized in that, The bottom of the insert body (1) is conical.

7. The cooling insert as claimed in claim 1, characterized in that, The material of the insert body (1) is H13 mold steel.

8. The cooling insert as claimed in claim 1, characterized in that, The heat insulation groove (102) is filled with nano-aerogel heat insulation sheet.

9. A low-pressure aluminum subframe mold, comprising a mold body (4), characterized in that, The mold body (4) is provided with a mounting hole (401), and the cooling insert as described in claim 1 is fixedly connected in the mounting hole (401).

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