Pouring gate structure of non-uniform wall thickness shell part die-casting die

Abstract

The utility model relates to a pouring gate structure of a non-uniform wall thickness shell part die-casting die. A pouring gate comprises a straight pouring gate, a transverse pouring gate and a branch transverse pouring gate which are communicated in sequence. One end of the sprue is connected with the cross gate through the arc transition part, and the other end of the sprue is connected with the filling inlet; sprues are formed in the branch cross gates; the cross sectional area, perpendicular to the melt flowing direction, in the pouring gate is gradually reduced from the straight pouring gate to the pouring gate; the shape of the joint of the cross gate and the branch cross gate is that the perimeter of the cross section perpendicular to the solution flowing direction is increased along with approaching to the pouring gate; the inner circle radius of the arc transition part is defined as r, and the outer circle radius of the arc transition part is defined as R; the average thickness of the cross gate is defined as H; r = r + H; according to the pouring gate structure disclosed by the utility model, the problems of air trapping, air entrapment and the like of the pouring gate are effectively solved, so that the resistance of the pouring gate is reduced as far as possible and the temperature and filling speed of molten aluminum are increased in the filling process of a casting, and the mechanical property of a product is effectively improved.

Description

Technical Field

[0001] The utility model relates to the field of aluminum alloy casting, in particular to a runner structure of a die-casting mold for a shell part with a non-uniform wall thickness. Background Art

[0002] With the global development needs of energy conservation, emission reduction, carbon peak and carbon neutrality, lightweight and green parts in various industries have become an inevitable development path. For the die-casting industry, this is an opportunity as well as a challenge. In the new environment, castings not only pursue external beauty, but also pay more attention to the strength of mechanical properties.

[0003] Die casting of shell parts with non-uniform wall thickness is very easy to cause deformation of castings due to the uneven wall thickness. Fatal defects such as shrinkage, looseness, and pores. The quality of the casting process design largely determines the quality of the casting. In the design of the flow channel of most die-casting molds, the cross-sectional area of ​​the flow channel fluctuates, changing back and forth, resulting in unsmooth flow and large flow resistance, which requires greater pressure, faster speed, and higher temperature in production, resulting in various problems in the product, such as product cracking, many internal pores, loose internal structure, and coarse grains. The mold will also reduce the service life to a certain extent. In summary, the appearance of pores and loose internal structure in the casting makes it usually impossible for die castings to undergo high-temperature heat treatment and welding.

[0004] The runner of a die-casting mold usually consists of a straight runner, a cross runner, and a branch runner. The straight runner is connected to the filling inlet, and the straight runner and the cross runner form an angle that is approximately right angles. The aluminum liquid is prone to erosion and air entrainment during filling, and the back pressure is large, which slows down the speed. In the prior art, the connection here is usually set directly to a right angle. A better solution is to set it to an arc transition, but since the size of the arc is designed by the designer based on experience, it cannot actually and effectively reduce the turbulence and turbulence of the aluminum liquid in the runner. For die-casting of shell parts with non-uniform wall thickness, it is common to use fan-shaped runners and tapered runners. Such runners usually have wider and thinner gates, but the runner design from the filling inlet to the gate is unreasonable, and the cross-sectional area from the inlet to the gate changes drastically, resulting in a large change in the flow rate of the molten metal, which is prone to problems such as molten metal splashing, turbulence, and turbulence. In particular, when the supply speed of the molten aluminum is increased, the molten aluminum is prone to oscillation drastically. Therefore, it is difficult to simultaneously shorten the molten metal supply time and suppress the air entrainment caused by the unstable flow of the molten aluminum. Utility Model Content

[0005] 1. Technical issues to be resolved

[0006] In order to solve the above problems in the prior art, the utility model provides a runner structure of a die-casting mold for a shell component with a non-uniform wall thickness.

[0007] (II) Technical solution

[0008] In order to achieve the above-mentioned purpose, the main technical solutions adopted by the utility model include:

[0009] The runner structure of a die-casting mold for a shell part with non-uniform wall thickness includes a runner; the runner includes a straight runner, a cross runner, and a branch cross runner that are connected in sequence; one end of the straight runner is connected to the cross runner through an arc transition portion, and the other end is connected to a filling inlet; a gate is formed on the branch cross runner; the cross-sectional area of ​​the runner perpendicular to the flow direction of the molten liquid gradually decreases from the straight runner to the gate; the inner circle radius of the arc transition portion is defined as r, and the outer circle radius is defined as R; the average thickness of the cross runner is defined as H; and R=r+H.

[0010] Furthermore, the connection between the runner and the branch runner is in a shape in which the perimeter of the cross section perpendicular to the solution flow direction becomes longer as it approaches the gate.

[0011] Furthermore, the cross-sectional shape of the runner is a rounded rectangle.

[0012] Furthermore, the outer circle radius R is 8 mm ≤ R ≤ 30 mm.

[0013] Furthermore, the angle between the outer wall of the sprue and the outer wall of the runner is greater than 90°.

[0014] Furthermore, the angle between the inner side wall of the sprue and the inner side wall of the runner is 90°.

[0015] Furthermore, a water drop-shaped diversion portion is formed in the middle of the branch runner; and the small head of the water drop-shaped diversion portion faces the gate position.

[0016] Furthermore, inverted slag bags are formed at the outer ends of both sides of the branch runner.

[0017] (III) Beneficial effects

[0018] The beneficial effects of the utility model are as follows: by optimizing the shape structure of the runner, the size of the arc transition part is reasonably set, so as to ensure the stability of the aluminum liquid when it flows, the speed loss will not be very large when passing through the arc transition part, and it can smoothly pass through the turning point, thereby suppressing the unstable flow of the aluminum liquid; and in the connecting section of the runner and the branch runner, by gradually increasing the circumference of the cross section and reducing the cross-sectional area, it is ensured that the aluminum liquid smoothly changes from a columnar shape to a wide thin sheet shape and flows into the cavity, the fluidity of the aluminum liquid is effectively improved, and the flow rate change of the aluminum liquid is suppressed under the changed cross-sectional shape, so that the aluminum liquid enters the cavity in a stable and good flow state, avoiding turbulence and turbulence of the aluminum liquid. Even if the speed of the aluminum liquid is high during pouring, the unstable state caused by the transitional oscillation of the aluminum liquid can be effectively suppressed. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the technical solution of the implementation mode of the utility model, the drawings required for use in the implementation mode will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the utility model and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without paying creative work.

[0020] Figure 1 It is a three-dimensional diagram of the pouring channel structure of the utility model;

[0021] Figure 2 It is the front view of the runner structure of the utility model;

[0022] Figure 3 It is a side view of the runner structure of the utility model;

[0023] Figure 4 This is a cloud computing simulation verification diagram of the runner of the utility model;

[0024] Figure 5 This is the cloud computing simulation verification diagram of the runner when R is less than 8mm;

[0025] Figure 6 This is the cloud computing simulation verification diagram of the runner when R is equal to 35mm;

[0026] Figure 7 This is the cloud computing simulation verification diagram of the runner when R is equal to 50mm;

[0027] Figure 8 This is the cloud computing simulation verification diagram of the runner when R is equal to 60mm;

[0028] Fig. 9 This is the cloud computing simulation verification diagram of the runner when R is equal to 70mm;

[0029] Explanation of reference numerals: 100, sprue; 110, filling inlet; 120, arc transition portion; 200, runner; 300, branch runner; 310, gate; 320, diversion portion; 330, slag bag. DETAILED DESCRIPTION

[0030] In order to make the purpose, technical scheme and advantages of the embodiments of the utility model clearer, the technical scheme in the embodiments of the utility model will be clearly and completely described below in conjunction with the drawings in the embodiments of the utility model. Obviously, the described embodiments are part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without making creative work belong to the scope of protection of the utility model. Therefore, the following detailed description of the embodiments of the utility model provided in the drawings is not intended to limit the scope of the utility model for which protection is sought, but merely represents the selected embodiments of the utility model. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without making creative work belong to the scope of protection of the utility model.

[0031] Example:

[0032] The runner structure of the die-casting mold for a shell part with non-uniform wall thickness includes a straight runner 100, an arc transition portion 120, a cross runner 200, and a branch cross runner 300 connected in sequence; a filling inlet 110 is provided at one end of the straight runner 100, and aluminum liquid / melt is filled into the runner through the inlet and finally enters the cavity; the other end of the straight runner 100 is connected to the cross runner 200 through the arc transition portion 120; a gate 310 is formed on the branch cross runner 300 for connecting with the cavity of the mold; the cross-sectional area in the runner perpendicular to the flow direction of the molten metal gradually decreases from the straight runner 100 to the gate 310; this change in the cross-sectional area of ​​the runner is used to ensure the stability of the flow rate of aluminum liquid / melt. When the aluminum liquid / melt flows in the runner, the flow rate of the aluminum liquid / melt will be reduced due to the existence of viscosity, and the flow rate of the aluminum liquid / melt can be increased by reducing the size of the cross-sectional area along the flow direction, and the interaction between the two ensures the stability of the flow rate of the aluminum liquid / melt;

[0033] In one embodiment of the present invention, the cross-sectional area of ​​the sprue 100 is 26-27 cm 2 ; The cross-sectional area of ​​the arc transition portion 120 is 25-26cm 2 ; The cross-sectional area of ​​the runner 200 is 18-22cm 2 ; The sum of the cross-sectional areas of the branch runners is: 17-18cm 2 ; Gate 310 area is 14-15.5cm 2 ; The thickness of gate 310 is 2.5-3.5mm;

[0034] However, simply controlling the change in the size of the runner cross-sectional area is limited in controlling the flow stability of molten aluminum / melt, and cannot completely solve the technical problem. At the connection between the straight runner 100 and the cross runner 200, the stability of the molten aluminum / melt when turning is the most difficult to ensure. In the rapid die-casting process, it is very easy to cause splashing, turbulence, and turbulence of the molten aluminum, thereby generating air entrainment, resulting in a decrease in the density of the final die-casting. The utility model redesigns the inner and outer fillets of the arc transition portion 120, the inner radius of the arc transition portion is defined as r, and the outer radius is defined as R; the average thickness of the cross runner 200 is defined as H; R=r+H, the inner radius r is a preset value, and when the outer radius R satisfies the formula, the stability of the molten aluminum / melt when passing through is greatly enhanced, and after verification by cloud computing simulation and actual die-casting product verification, the flow stability of the molten aluminum / melt at the turning is greatly increased; that is, when the outer radius R meets the conditions, such as Figure 4 As shown in b / 4c, R in the figure is 20mm, and the top of the aluminum liquid / melt tends to be horizontal when entering the cross runner 200, that is, the speed of the aluminum liquid / melt reaching the cross runner 200 is basically the same, ensuring that the top flow velocity of the aluminum liquid / melt tends to be consistent when entering the cross runner 200, reducing the probability of aluminum liquid / melt entrainment.

[0035] When the outer radius R is too small, R is less than 8mm, such as Figure 5 As shown, when the aluminum liquid / melt enters the runner 200, there are obvious undulations on the top. The outer circle radius is too small, resulting in greater resistance to the aluminum liquid / melt at the outer circle, and the turning point has a poor guiding effect on the aluminum liquid / melt, which is prone to collision, causing splashing of the aluminum liquid / melt. The aluminum liquid / melt at the inner circle can reach the runner 200 faster, and splashing, turbulence, and air entrainment will occur when filling the cavity. The framed position in the figure affects the quality of the die-casting product;

[0036] When the outer radius R is too large, such as Figure 6-9 As shown in the figure, R=35mm, R=50mm, R=60mm, and R=70mm respectively. When the aluminum liquid / melt enters the runner 200, the outer radius is too large, resulting in less resistance to the aluminum liquid / melt at the outer circle, and it can reach the runner 200 faster, causing the end surface of the aluminum liquid / melt in the runner 200 to be uneven, and then it is easy to splash, turbulent, and turbulent when entering the cavity, and air entrainment occurs. The framed position in the figure affects the quality of the die-casting product;

[0037] The angle between the outer wall of the straight runner 100 and the outer wall of the cross runner 200 is greater than 90°, and the angle between the inner wall of the straight runner 100 and the inner wall of the cross runner 200 is 90°; the angle between the outer walls is greater than 90°, which can ensure the smoothness of the runner while meeting the R dimension, and the angle between the inner walls is 90° to ensure that the cross runner 200 remains in a vertical state during pouring, and the aluminum liquid / melt in the cross runner 200 can enter the branch cross runner 300 at a straight and stable speed, and pouring is performed in an anti-gravity manner to better avoid the occurrence of air entrainment.

[0038] The shape of the connection between the runner 200 and the branch runner 300 is that the perimeter of the cross section perpendicular to the solution flow direction becomes longer as it approaches the gate 310; from the perspective of the aluminum liquid / melt flow direction, the flow rate loss is offset by the gradual reduction of the cross-sectional area, and the change rate of the flow rate is suppressed when the aluminum liquid is poured into the shape by the lengthening of the cross-sectional perimeter. The cross-sectional length of the branch runner 300 is long and thin, and the aluminum liquid / melt can be supplied in a wider direction. The melt has higher fluidity and is less likely to be obstructed; Figure 4 As shown in d / 4e / 4f, the aluminum liquid / melt can diffuse outward from the branch cross runner 300 into the cavity evenly like water waves, filling the cavity without splashing, turbulence or turbulence; through the above-mentioned design parameter limitation of the runner structure, not only is it ensured that the loss of key parameters such as temperature, speed and pressure of the aluminum liquid is minimized during the filling process, but also the aluminum liquid will not generate air entrainment or air entrapment during the process of filling the runner, thereby effectively exhausting the gas and obtaining a casting with excellent quality.

[0039] In one embodiment of the utility model, a teardrop-shaped diverter 320 is formed in the middle of the branch cross runner 300; the small head of the teardrop-shaped diverter 320 is directed toward the gate 310; the teardrop-shaped shape of the diverter 320 reduces the obstruction to the aluminum liquid / melt, allowing it to move better to both sides; inverted slag bags 330 are formed at the outer ends of both sides of the branch cross runner 300. The application of the slag bag 330 at the end of the runner can store the cold material at the front end, so that the material with higher temperature can fill the cavity, ensuring sufficient filling time, thereby obtaining high-quality castings.

[0040] The above description is only an embodiment of the present invention, and does not limit the patent scope of the present invention. Any equivalent transformations made using the contents of the specification and drawings of the present invention, or directly or indirectly applied in the relevant technical field, are also included in the patent protection scope of the present invention.

Claims

1. The runner structure of the die-casting mold for a shell part with non-uniform wall thickness is characterized by: The invention comprises a runner; the runner comprises a straight runner (100), a horizontal runner (200), and a branch horizontal runner (300) which are connected in sequence; one end of the straight runner (100) is connected to the horizontal runner (200) through a circular arc transition portion (120), and the other end is connected to a filling inlet (110); a gate (310) is formed on the branch horizontal runner (300); the cross-sectional area of ​​the runner perpendicular to the flow direction of the molten liquid gradually decreases from the straight runner (100) to the gate (310); the inner radius of the circular arc transition portion (120) is defined as r, and the outer radius is defined as R; the average thickness of the horizontal runner (200) is defined as H; and R=r+H.

2. The runner structure of the die-casting mold for a shell component with non-uniform wall thickness according to claim 1, characterized in that: The shape of the connection between the runner (200) and the branch runner (300) is such that the perimeter of the cross section perpendicular to the solution flow direction becomes longer as it approaches the gate (310).

3. The runner structure of the die-casting mold for a shell component with non-uniform wall thickness according to claim 1, characterized in that: The cross-sectional shape of the runner (200) is a rounded rectangle.

4. The runner structure of the die-casting mold for a shell component with non-uniform wall thickness according to claim 1, characterized in that: The size of the outer circle radius R is 8mm≤R≤30mm.

5. The runner structure of the die-casting mold for a shell component with non-uniform wall thickness according to claim 1, characterized in that: The included angle between the outer wall of the sprue (100) and the outer wall of the runner (200) is greater than 90°.

6. The runner structure of the die-casting mold for a shell component with non-uniform wall thickness according to claim 1, characterized in that: The included angle between the inner side wall of the sprue (100) and the inner side wall of the runner (200) is 90°.

7. The runner structure of the die-casting mold for a shell component with non-uniform wall thickness according to claim 1, characterized in that: A water drop-shaped flow dividing portion (320) is formed in the middle of the branch runner (300); the small end of the flow dividing portion (320) faces the gate (310).

8. The runner structure of a die-casting mold for a shell component with a non-uniform wall thickness according to claim 1, characterized in that: Inverted slag bags (330) are formed at the outer ends of both sides of the branch runner (300).

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