Aluminum alloy casting mold

Abstract

The present application relates to a kind of moulds for casting aluminum alloy, at least including fixed mould and movable mould, the fixed mould and movable mould inside hollow form opening faces outside containing cavity, each described containing cavity is equipped with chills, each described chill is equipped with multiple cooling channels, each described cooling channel includes cooling section and reflux section, cooling section is from outer end to inner end along the melt aluminum alloy liquid flow route and is close to mould cavity with curve, the inner end of cooling section is close to gate and is connected with the inner end of reflux section, the outer end of cooling section and reflux section is connected with high-temperature resistant hose via quick coupling, the high-temperature resistant hose of cooling section outer end is connected with compressed air pipeline, described high-temperature resistant hose is equipped with solenoid valve, the high-temperature resistant hose between described solenoid valve and quick coupling is equipped with water delivery pipe that extends into high-temperature resistant hose, the other end of described water delivery pipe extends into water tank containing distilled water.In the present application, special mould structure is used, so that the casting has good solidification sequence and sufficient solidification speed when solidifying.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of aluminum alloy casting, in particular to an aluminum alloy casting mold. BACKGROUND

[0002] Aluminum alloy casting is a kind of aluminum alloy that fills the casting mold with molten aluminum alloy to obtain various shaped part blanks. It has the advantages of high specific strength, good corrosion resistance and casting process, and small limitation by part structure design.

[0003] The most influential factor on the performance of the casting in aluminum alloy casting is the solidification speed and the solidification sequence. Good solidification sequence can ensure that the casting has no shrinkage hole and shrinkage porosity defects. Faster solidification speed can refine the size of alpha-Al, make the distribution uniform, avoid segregation, reduce the size of the transition zone, and improve the metal feeding condition. Therefore, faster solidification speed and good solidification sequence are the research direction of the casting industry.

[0004] The cooling intensity of the mold is the main influencing factor of the solidification speed of the aluminum alloy. The cooling method of the mold is mainly divided into air cooling and water cooling. The air cooling process is easy to control, and the mold cooling system is simple. However, the air cooling process has long cooling time and low cooling intensity, which limits the improvement of the mechanical properties of the product. The water cooling process has large cooling intensity, which can effectively improve the mechanical properties of the product. However, the water cooling process has too large cooling intensity, and it is not easy to control the solidification sequence in production. The wheel casting is prone to have shrinkage hole and shrinkage porosity defects.

[0005] Therefore, there is a need for an aluminum alloy casting mold that has both fast solidification speed and good solidification sequence. SUMMARY

[0006] To solve the above technical problems, the present application provides an aluminum alloy casting mold, which aims to use special cooling channels and cooling medium to make the casting have good solidification sequence and sufficient solidification speed when solidifying.

[0007] In order to achieve the above purpose, the technical scheme of the present application is as follows:

[0008] An aluminum alloy casting mold comprises at least a fixed mold and a movable mold, the fixed mold and the movable mold are hollow inside to form outward-facing containing cavities, each containing cavity is provided with a chill, each chill is provided with a plurality of cooling channels, each cooling channel comprises a cooling section and a backflow section, the cooling section is curved along the flowing route of molten aluminum alloy from the outer end to the inner end close to the cavity, the curve is an arc curve or a wave curve, the inner end of the cooling section is close to the gate and connected to the inner end of the backflow section, the outer ends of the cooling section and the backflow section are connected to high-temperature-resistant hoses through quick couplings, the high-temperature-resistant hose at the outer end of the cooling section is connected to a compressed air pipeline, an electromagnetic valve is arranged on the high-temperature-resistant hose, a water delivery pipe is arranged in the high-temperature-resistant hose between the electromagnetic valve and the quick coupling, the other end of the water delivery pipe extends into a water tank containing distilled water.

[0009] The application adopts 3D printing technology to realize the distribution of cooling channels in the cold iron, the cold iron is located in the mold, the cooling channels cool the cold iron, and the cold iron cools the mold, because the cold iron itself has the effect of accelerating cooling, but as the number of casting processes increases, the heat absorbed by the cold iron is saturated, and the cooling effect is weakened, therefore, the cooling channels are used in cooperation with the cold iron to eliminate the heat absorption saturation state of the cold iron, and a larger temperature gradient is provided during the cooling and solidification stage of the casting, because the cold iron is used as a transition, the cooling gradient of the mold cavity changes uniformly, and the temperature gradient in the mold cavity is only distributed along the flowing direction of the molten aluminum alloy, in the process of air cooling, the negative pressure generated by the high-speed flowing air carries the distilled water into the cooling channel to form an atomization effect, because the cooling section of the application is curved along the flowing direction of the molten aluminum alloy from the outer end to the inner end, the atomized distilled water contacts the inner wall of the cooling channel in the range from the outer end to the middle of the cooling section, and the half length close to the outer end of the cooling section is cooled intensively, in the half length close to the inner end of the cooling section, the water mist vaporizes due to heat absorption, and the heat capacity is greater than that of air, so it still has a strong cooling effect, but the cooling strength is lower than that of the half length close to the outer end of the cooling section, which ensures that the cooling channel of the application can produce different cooling strengths on the mold, at the beginning of cooling, the temperature difference of the cooling medium (compressed air, water mist, water vapor) between the outer end and the inner end of the cooling section is 35-55℃, the temperature difference of different parts of the casting corresponding to the mold between the outer end of the cooling section and the inner end of the cooling section reaches 120-240℃, and as the compressed air continues to flow in, the molten aluminum alloy liquid close to the outer end of the mold crystallizes and solidifies rapidly, at this time, the water mist no longer vaporizes from the outer end of the cooling section, and the vaporization area of the water mist gradually shifts to the inside of the cooling section, and then gradually makes the molten aluminum alloy liquid crystallize and solidify rapidly along the route opposite to the flowing direction of the molten aluminum alloy liquid, forming a faster solidification speed and a good solidification sequence, avoiding composition segregation, and enabling the molten aluminum alloy liquid at the gate to be well fed, ensuring that the casting has no shrinkage and porosity defects, and improving the mechanical strength of the casting.

[0010] The curve is an arc curve or a wavy curve, the arc curve is relatively smooth as a whole, so the water mist vaporization area is longer, the wavy curve is more rugged, so the water mist contacts the inner wall of the cooling channel more quickly, so the vaporization area is shorter, and the cooling gradient is larger, and the temperature difference between the outer end of the cooling section and the inner end of the cooling section is larger.

[0011] When the compressed air is stopped, the water in the water delivery pipe will flow into the high-temperature resistant hose due to inertia, and the distilled water may remain in the cooling channel in the form of liquid water droplets due to the reduced speed and flow of the compressed air during the closing process, which will form a cold spot during the next casting process, causing the corresponding cavity to form an out-of-sequence cooling state, which will destroy the cooling sequence. In order to solve this problem, the present application further improves the technical scheme:

[0012] Further, a buffer ball is arranged on the high-temperature resistant hose between the end of the water delivery pipe and the quick connector, the buffer ball is in the shape of an ellipsoid, and the water delivery pipe is provided with a flow regulating device.

[0013] The buffer ball can make the water flowing out of the water delivery pipe due to inertia remain inside the buffer ball and not enter the cooling channel, and the ellipsoid shape can also carry away the remaining water when the compressed air flows quickly for cooling, which will not remain in the buffer ball. The flow regulating device can be a stop valve, a proportional valve, a servo valve, etc. that can adjust the opening degree, or even a perforated plate for flow control. After the flow regulating device is arranged, the present application can be applied to molds with different cooling intensity and cooling gradient requirements, and is more universally applicable.

[0014] Further, the inner diameter of the cooling section gradually decreases from the outer end to the inner end.

[0015] Since the inner diameter of the cooling section gradually decreases from the outer end to the inner end, the compressed air flows from the outer end to the inner end of the cooling section, and the volume change of the compressed air carrying water mist is not large, but when the water mist completes the cooling effect in the cooling channel, it will vaporize, and the volume of the water mist will increase sharply after vaporization, while the flow area is gradually decreasing. This makes the flow rate of the compressed air mixed with water vapor increase, forming two different flow rate areas in the cooling section. One flow rate area is near the outer end of the cooling section, using compressed air and water mist for strong cooling, and the flow rate is slow. The other flow rate area is near the inner end of the cooling section, using compressed air and water vapor for cooling, which is weaker than water mist cooling in terms of cooling intensity, and the flow rate is faster. The faster flow rate can also speed up the cooling speed of the mold. Although the present application increases the temperature gradient and the cooling intensity near the inner end of the cooling section is weaker than the area near the outer end of the cooling section, the cooling intensity near the inner end of the cooling section of the present application is still stronger than that of the prior art. The water mist vaporization area can make the molten aluminum alloy liquid near the outer end of the cooling section solidify quickly and the mold temperature drop, and the water mist vaporization area can also move towards the inner end of the cooling section, further increasing the cooling intensity.

[0016] Further, the diameter of the outer end of the cooling section is 1.1-1.4 times the diameter of the inner end of the cooling section.

[0017] The technical scheme further limits the degree of the gradually decreasing inner diameter of the cooling section from the outer end to the inner end, limits the ratio of the diameter of the outer end of the cooling section to the diameter of the inner end of the cooling section, and in this range, on the one hand, the increase of the water mist vaporization volume does not affect the passage and carrying of the water mist by the compressed air, and on the other hand, the temperature gradient of the mold can be increased as much as possible under the premise of improving the cooling intensity, so that the molten aluminum alloy liquid solidifies in sequence.

[0018] Further, the cooling section is provided with a spiral ridge along the length direction of the cooling section.

[0019] Further, the ratio of the height of the ridge to the diameter of the cooling section where the ridge is located is 1:10-1:15.

[0020] The cooling section itself is in a curved state, and the spiral ridge in the cooling section can guide the spiral flow of the compressed air, and when the compressed air flows spirally, the water mist in the compressed air is more likely to contact the inner wall of the cooling channel due to the centrifugal effect, and then moves along the spiral ridge, thereby improving the cooling intensity, and the ridge has better heat dissipation effect due to the increased area of the inner wall of the cooling section.

[0021] Further, the cooling section at the place where the thickness of the cavity is uniform and consistent is in a smooth curve shape, and the cooling section at the place where the thickness of the cavity increases is provided with a turning portion towards the cavity.

[0022] The cooling section at the place where the thickness of the cavity is uniform and consistent is in a smooth curve shape and close to the cavity, which can realize sequential cooling (the casting solidifies in sequence), if a protrusion suddenly appears in the middle of the cavity, the protrusion will suddenly increase the thickness of the cavity and then suddenly decrease the thickness, such thickness change will form a local hot spot different from other areas, which affects the sequential cooling, and the turning portion towards the cavity arranged at the place where the thickness of the cavity suddenly increases can make the airflow and water mist (or water vapor) in the cooling channel more impact on the inner wall of the cooling channel at the turning portion, thereby improving the cooling intensity and overcoming the local hot spot, and when a deep groove suddenly appears in the middle of the cavity (i.e. the thickness of the cavity suddenly decreases and then suddenly increases), a parallel channel can be arranged on the side away from the deep groove, so that the cooling section is divided into two channels, and thus a part of the compressed air weakens the cooling intensity because it is away from the place where the thickness suddenly decreases, thereby avoiding the shrinkage hole and shrinkage in the casting after the preferential solidification of this place.

[0023] Further, the turning portion is in an arc shape, and the two ends of the turning portion are smoothly connected with the cooling section.

[0024] The arc-shaped turning portion does not excessively increase the wind resistance and can locally improve the cooling intensity.

[0025] Further, the central angle of the turning portion is α, and the size of α is positively correlated with the proportion of the increase of the thickness of the cavity.

[0026] That is: the proportion of the amount of cavity thickness increase relative to the cavity thickness of the position and the center angle of the turning point α is proportional change.

[0027] Further, the high-temperature-resistant hoses of the outer ends of the cooling section and the return section are jointly connected with a reversing valve, and the connection position of the high-temperature-resistant hose of the outer end of the cooling section with the reversing valve is located between the electromagnetic valve and the buffer ball.

[0028] When the aluminum alloy is cast and cooled, the solidification sequence of the casting needs to be ensured, and therefore, the present application uses the water mist cooling mode carried by compressed air to provide a large temperature gradient, which is beneficial to the solidification of the casting, but during the interval between two adjacent castings, the mold needs to be preheated, and the main preheating methods are heat conduction oil preheating and gas baking preheating, and no matter which method is used, the mold needs to be uniformly heated so that the molten aluminum alloy liquid can have a full flow rate in the cavity, and generally, the mold as a whole needs to be heated to 200-300 DEG C, and the thinner the casting is, the higher the preheating temperature needs to be, and the water mist cooling mode carried by compressed air used in the present application will form a temperature gradient in the mold, so that the temperature of the part close to the outer end of the cooling section is too low, when the preheating of this part reaches the requirement, the temperature of the part close to the gate is already too high, and the cooling speed will be slow in the subsequent cooling process, resulting in composition segregation, and if only the temperature of the part close to the inner end of the cooling section is preheated to the standard, the preheating temperature of the part close to the outer end of the cooling section is too low, and the molten aluminum alloy liquid will be rapidly cooled in the flow process, and the cavity cannot be filled.

[0029] After the reversing valve is arranged in the present application, the flow direction of the compressed air in the cooling channel can be switched by using the reversing valve in the late cooling period and before the mold is opened (that is, when the casting as a whole has been cooled and solidified, and the remaining gate and flow channel have not been solidified), the reverse-flowing compressed air will blow out the residual water in the cooling channel, and because the compressed air flows in the reverse direction, the relatively high temperature near the gate will be carried back to the cooling section, and the mold temperature near the cavity tends to be consistent when the mold is opened, so that the temperature gradient in the mold is eliminated, and therefore, the molten aluminum alloy liquid can flow smoothly in the next casting process, and the problem that the molten aluminum alloy liquid cannot fill the cavity due to rapid cooling caused by contacting the relatively low-temperature inner wall of the cavity during the flow process of the molten aluminum alloy liquid is avoided.

[0030] On this basis, a one-way valve can be arranged on the water delivery pipe to prevent the water in the water delivery pipe from flowing back to the water tank after the flow direction of the compressed air is switched, which affects the next cooling.

[0031] Through the above technical solution, the present application has the following beneficial effects:

[0032] The cooling channel of the present application is arranged in the chill, the chill is located in the mold, the chill is cooled through the cooling channel, then the chill cools the mold, the stable cooling effect is realized through the combination of the chill and the cooling channel, the water mist is driven by the compressed air, and the strong cooling intensity and good solidification sequence are realized through the movable water mist vaporization area.

[0033] The present application can realize different cooling intensity changes through the flow regulating device on the water delivery pipe, and is suitable for the production of products with various cooling requirements.

[0034] The convex ridge in the cooling channel of the present application not only enables the compressed air in the cooling channel to carry the water mist to move spirally, but also accelerates the contact between the water mist and the inner wall of the cooling channel.

[0035] The reversing valve is arranged in the present application, the flow direction of the compressed air in the cooling channel can be switched, so that the mold has a large temperature gradient and strong cooling intensity in the production process, and the temperature in the mold tends to be uniform in the production interval, and the preheating effect of the preheating device on the mold is good.

[0036] The present application utilizes the curved cooling channel and the water mist to cooperate with the compressed air for cooling, the cooling effect is good, the control is convenient, the mold has a large temperature gradient, the casting is rapidly cooled in the required sequence, the feeding performance is ensured, the shrinkage hole and shrinkage porosity are avoided in the casting, and the overall mechanical properties of the casting are improved.

[0037] The overall mechanical properties of the present application are uniform and consistent, the comprehensive effect is better than that of air cooling and water cooling, and the design and utilization of the casting are more accurate and reasonable. BRIEF DESCRIPTION OF DRAWINGS

[0038] Figure 1 is a structural schematic view of the second embodiment of the present application;

[0039] Figure 2 is a sectional front view of the second embodiment of the present application;

[0040] Figure 3 is a top view of the relative position relationship between the cooling channel and the cavity of the second embodiment of the present application;

[0041] Figure 4 is an enlarged view of A of Figure 3 ;

[0042] Figure 5 is an axial view of the relative position relationship between the cooling channel and the cavity of the second embodiment of the present application;

[0043] Figure 6 is a sectional front view of the first embodiment of the present application;

[0044] Figure 7 This is an isometric view of the relative position of the cooling channel and the cavity in Embodiment 1 of the present invention.

[0045] The attached diagram is labeled as follows: 1. Fixed mold; 2. Moving mold; 3. Side mold; 4. Chill; 5. Cooling channel; 6. Cooling section; 7. Recirculation section; 8. High-temperature resistant hose; 9. Solenoid valve; 10. Water pipe; 11. Rack; 12. Runner; 13. Gate; 14. Buffer ball; 15. Turning point; 16. Directional valve. Detailed Implementation

[0046] The present invention will be further described below with reference to the accompanying drawings and specific embodiments:

[0047] Example 1:

[0048] like Figure 6 and Figure 7 As shown, to make it clearer, Figure 7 The mold cavity and cooling channels are shown in solid form. This embodiment is a casting mold for an aluminum alloy wheel hub, mainly using low-pressure casting. This embodiment of an aluminum alloy casting mold includes a fixed mold 1, a moving mold 2, and a side mold 3. The fixed mold 1, moving mold 2, and side mold 3 are joined to form a cavity. The interiors of the fixed mold 1, moving mold 2, and side mold 3 are all hollow, forming outward-facing receiving cavities. Each receiving cavity is equipped with a chill 4. Multiple cooling channels 5 are provided within the chill 4 of the fixed mold 1 and moving mold 2. Each cooling channel 5 includes a cooling section 6 and a recirculation section 7. The cooling section 6 extends from the outer end inwards. The end of the cooling section 6 is curved along the flow path of the molten aluminum alloy and approaches the cavity. The inner end of the cooling section 6 is close to the gate 13 and connects to the inner end of the return section 7. The outer ends of the cooling section 6 and the return section 7 are both located on the chill 4. The outer ends of the cooling section 6 and the return section 7 are connected to the high-temperature resistant hose 8 via quick connectors. The high-temperature resistant hose 8 at the outer end of the cooling section 6 is connected to the compressed air pipeline. The high-temperature resistant hose 8 is equipped with a solenoid valve 9. A water supply pipe 10 is provided on the high-temperature resistant hose 8 between the solenoid valve 9 and the quick connector, extending into the high-temperature resistant hose 8. The other end of the water supply pipe 10 extends into a water tank containing distilled water.

[0049] The cooling section 6 is provided with spiral ribs 11 along the length of the cooling section 6.

[0050] The ratio of the height of the protrusion 11 to the diameter of the cooling section 6 is 1:10 to 1:15.

[0051] The liquid rising time is 10s, the filling time is 34s, the pressure maintaining time is 190s (the air cooling process in the prior art is 255s, and the water cooling process is 180s), the pressure releasing time is 50s. In the cooling process, because the cooling section 6 is curved, the water mist vaporization area moves with the compressed air passing time, and sufficient cooling effect is achieved. Therefore, the pressure maintaining time of the embodiment does not increase too much compared with the water cooling process. According to statistics, the embodiment can reach 172 pieces per 12 hours in low pressure casting, the production efficiency is increased by 19.4% compared with the air cooling process, and the production efficiency is reduced by 4.4% compared with the water cooling process. However, due to the strong cooling intensity and good solidification sequence, the data obtained by relative detection according to the GB / T228-2002 standard by using the German ZWICK-Z100 type material testing machine are as follows:

[0052]

[0053] The maximum difference value of the yield of each position of the casting is 20MPa, and the maximum difference value of the tensile strength of each position is 33MPa, which are uniform and consistent as a whole. Other cooling processes have a large numerical difference, especially the yield strength difference between the inner rim and the spoke, which reaches 30MPa, and the tensile strength difference between the inner rim and the spoke, which reaches 50MPa. In order to ensure safety, the lowest value is usually used as the design standard in design and use. The mold of the embodiment can make the mechanical properties of the casting tend to be consistent, and the overall performance is more stable. Even if the lowest value is used as the design standard, although the highest value of the mechanical properties of the embodiment is still lower than that of the water cooling, the lowest value of the embodiment is higher than the lowest mechanical property value of the water cooling. Therefore, the effect of the application of the embodiment is better than that of the water cooling. That is, the casting produced by the embodiment is better than the water cooling mold, which makes the design and use of the casting more accurate and reasonable.

[0054] Embodiment two:

[0055] The embodiment is a mold for producing an aluminum alloy brake mounting bottom plate. The mold cavity is divided into four parts, and the four cavities are communicated with the gate through the runner. The mold can be used for low pressure casting and high pressure casting, and even can be used for manual pouring.

[0056] As Figure 1 and Figure 2As shown, an aluminum alloy casting mold includes a fixed mold 1 and a moving mold 2. The fixed mold 1 and the moving mold 2 are joined to form multiple cavities. Each cavity is connected to a gate 13 via a runner 12. The fixed mold 1 and the moving mold 2 are hollow, forming outward-facing receiving cavities. Each receiving cavity is equipped with a chill 4, and each chill 4 has multiple cooling channels 5. Each cooling channel 5 includes a cooling section 6 and a reflux section 7. The cooling section 6 curves along the flow path of the molten aluminum alloy from its outer end to its inner end, approaching the cavity. The inner end of the cooling section 6 is close to the gate 13 and connects to the inner end of the reflux section 7. The outer ends of both the cooling section 6 and the reflux section 7 are located on the side of the mold and are connected to a quick-connect coupling. A high-temperature hose 8 is connected to a compressed air pipeline at the outer end of the cooling section 6. A solenoid valve 9 is installed on the high-temperature hose 8. A water supply pipe 10 is installed on the high-temperature hose 8 between the solenoid valve 9 and the quick connector, extending into the high-temperature hose 8. The outer diameter of the water supply pipe 10 is less than one-third of the inner diameter of the high-temperature hose 8. The other end of the water supply pipe 10 extends into a water tank containing distilled water. When compressed air flows through the high-temperature hose 8, the end of the water supply pipe 10 extending into the high-temperature hose 8 occupies the flow section inside the high-temperature hose 8. The high-speed flowing compressed air forms a negative pressure at the end of the water supply pipe 10, causing the distilled water to be drawn out of the water supply pipe 10 and dispersed by the compressed air to form a water mist.

[0057] A buffer ball 14 is provided on the high-temperature hose 8 between the end of the water supply pipe 10 extending into the high-temperature hose 8 and the quick connector. The buffer ball 14 is ellipsoidal in shape. The ellipsoidal buffer ball 14 is used to store water that rushes into the high-temperature hose 8 due to inertia when the compressed air is turned off, preventing this part of the water from continuing to enter the cooling channel 5 and forming a cold spot. The water supply pipe 10 is provided with a flow regulating device. In this embodiment, the flow regulating device is a ball valve. The flow control device can regulate the flow rate of distilled water delivered to the high-temperature hose 8, and can adapt to casting products of different sizes and thicknesses that require different cooling intensities. In this embodiment, it is used to produce aluminum alloy brake mounting base plates of different types (such as aluminum-magnesium alloys, aluminum-silicon alloys, etc.).

[0058] The inner diameter of the cooling section 6 gradually decreases from the outer end to the inner end.

[0059] The diameter of the outer end of the cooling section 6 is 1.1 to 1.4 times the diameter of the inner end of the cooling section 6.

[0060] like Figure 4 As shown, the cooling section 6 is provided with spiral ribs 11 along the length of the cooling section 6.

[0061] The ratio of the height of the protrusion 11 to the diameter of the cooling section 6 is 1:10 to 1:15.

[0062] likeFigure 3 and Figure 5 shown in FIG. 4, wherein Figure 3 is a top view of the position relationship between the cooling channel and the cavity (in order to clearly show the position relationship between the cooling channel and the cavity, Figure 3 in which the cooling channel is shown in solid lines and the cavity is shown in dashed lines), Figure 5 is an axonometric view of the position relationship between the cooling channel and the cavity (in order to clearly show the position relationship between the cooling channel and the cavity, Figure 3 in which the cooling channel and the cavity are both shown in solid form) The aluminum alloy brake mounting plate body is annular, and the thickness is uniform except for two thicker areas. The cooling section 6 at the cavity thickness uniform area is in a smooth curve shape. The cooling section 6 at the cavity thickness increased area is provided with a turning 15 towards the cavity. The turning 15 can be seen as an arc shape towards the cavity, and Figure 2 can be seen as an arc shape protruding outward, and the two ends of the turning 15 are in a smooth transition state. Figure 3

[0063] The angle of the central angle of the turning 15 is α, and the size of α is positively correlated with the proportion of the increased thickness of the cavity.

[0064] The high-temperature resistant hoses 8 at the outer ends of the cooling section 6 and the return section 7 are jointly connected to a reversing valve 16. The connection between the reversing valve 16 and the high-temperature resistant hoses 8 at the outer ends of the cooling section 6 is located between the electromagnetic valve 9 and the buffer ball 14. In order to make the drawing clearer and more understandable, Figure 1 in which only the reversing valve is shown on the front side.

[0065] In the embodiment, the liquid lifting time is 4s, the mold filling time is 8s, the pressure maintaining time is 140s (the air cooling process in the prior art is 220s, and the water cooling process is 135s), the pressure releasing time is 18s, and the actual detection by the buried thermocouple in the mold shows that the mold temperature near the flow channel of the casting is reduced to 582℃ at the 140s, and the casting has been completely solidified. The flow channel near the inner end of the cooling section also appears in a solidified state.

[0066] ​In use, the parting surface of the mold is gas baked before clamping, the parting surface of the mold is preheated, then clamping, injecting molten aluminum alloy liquid, opening the electromagnetic valve 9 to make the compressed air into the cooling channel 5, the negative pressure generated by the compressed air carries distilled water into the cooling channel 5, forming atomization effect, because the cooling section 6 of the present application is curved from the outer end to the inner end along the flowing direction of the molten aluminum alloy liquid, the atomized distilled water contacts the inner wall of the cooling channel 5 in the range from the outer end to the middle of the cooling section 6, and the half length close to the outer end of the cooling section 6 is strongly cooled, and the half length close to the inner end of the cooling section 6 is still strongly cooled due to the water mist vaporization, and the heat capacity is greater than that of air, which still has strong cooling effect, which ensures that the cooling channel 5 of the present application can produce different cooling intensity on the mold, and the temperature difference of the cooling medium (compressed air, water mist, water vapor) between the outer end of the cooling section 6 and the inner end of the cooling section 6 is 35-55℃ at the beginning of cooling, the temperature difference of different parts of the corresponding casting between the outer end of the cooling section 6 and the inner end of the cooling section 6 reaches 120-240℃, and with the continuous input of compressed air, the molten aluminum alloy liquid close to the outer end of the cavity crystallizes and solidifies rapidly, at this time the water mist no longer vaporizes from the outer end of the cooling section 6, and the vaporization area of the water mist gradually shifts to the inner end of the cooling section 6, and then gradually makes the molten aluminum alloy liquid crystallize and solidify rapidly along the opposite direction of the flowing direction of the molten aluminum alloy liquid, forming a faster solidification speed and a good solidification sequence, avoiding composition segregation, and can make the molten aluminum alloy liquid at the gate better feeding, ensuring that the casting has no shrinkage and porosity defects, and improving the mechanical strength of the casting.

[0067] In addition, because the present application only uses water mist vaporization to strengthen cooling, there is no water storage in the cooling channel, and there is no risk of leakage, so it is safer and more convenient to use.

[0068] The preferred embodiments of the present application are described in detail above in combination with the drawings, but the present application is not limited to the above-mentioned embodiments, and various modifications can be made to the technical solutions of the present application without departing from the spirit of the present application, i.e. the scope of the disclosure.

Claims

1. A mold for casting aluminum alloy, comprising at least a fixed mold (1) and a moving mold (2), characterized in that, The fixed mold (1) and the moving mold (2) are hollow inside to form an outward-facing receiving cavity. Each receiving cavity is provided with a chill (4). Each chill (4) is provided with multiple cooling channels (5). Each cooling channel (5) includes a cooling section (6) and a reflux section (7). The cooling section (6) flows from the outer end to the inner end along the flow path of the molten aluminum alloy in a curved shape close to the cavity. The inner end of the cooling section (6) is close to the gate (13) and connects to the inner end of the reflux section (7). The outer ends of the cooling section (6) and the reflux section (7) are connected to a high-temperature resistant hose (8) via a quick connector. The high-temperature resistant hose (8) at the outer end of the cooling section (6) is connected to a compressed air pipeline. The high-temperature resistant hose (8) is provided with a solenoid valve (9). A water supply pipe (10) is provided on the high-temperature resistant hose (8) between the solenoid valve (9) and the quick connector, extending into the high-temperature resistant hose (8). The other end of the water supply pipe (10) extends into a water tank containing distilled water. A buffer ball (14) is provided on the high-temperature hose (8) between the end of the water pipe (10) extending into the high-temperature hose (8) and the quick connector. The buffer ball (14) is ellipsoidal in shape. A flow regulating device is provided on the water pipe (10). The high-temperature resistant hoses (8) at the outer ends of the cooling section (6) and the return section (7) are connected to the reversing valve (16). The connection between the reversing valve (16) and the high-temperature resistant hoses (8) at the outer end of the cooling section (6) is located between the solenoid valve (9) and the buffer ball (14). The ellipsoidal buffer ball (14) is used to store water that flows into the high-temperature hose (8) due to inertia when the compressed air is turned off, preventing this water from continuing to enter the cooling channel (5) and forming a cold spot.

2. The mold for aluminum alloy casting according to claim 1, characterized in that, The inner diameter of the cooling section (6) gradually decreases from the outer end to the inner end.

3. The mold for aluminum alloy casting according to claim 2, characterized in that, The diameter of the outer end of the cooling section (6) is 1.1 to 1.4 times the diameter of the inner end of the cooling section (6).

4. The aluminum alloy casting mold according to claim 1, characterized in that, The cooling section (6) is provided with spiral ribs (11) along the length of the cooling section (6).

5. The mold for aluminum alloy casting according to claim 4, characterized in that, The ratio of the height of the protrusion (11) to the diameter of the cooling section (6) is 1:10 to 1:

15.

6. The aluminum alloy casting mold according to claim 1, characterized in that, The cooling section (6) where the cavity thickness is uniform is in the shape of a smooth curve, and the cooling section (6) where the cavity thickness increases is provided with a bend (15) towards the cavity.

7. The aluminum alloy casting mold according to claim 6, characterized in that, The transition (15) is arc-shaped, and the two ends of the transition (15) smoothly transition to the cooling section (6).

8. The aluminum alloy casting mold according to claim 7, characterized in that, The angle of the central angle opposite to the turning point (15) is α, and the size of α is positively correlated with the increase in the thickness of the cavity.

Images