Die casting method and die casting

Abstract

The application provides a die casting method and a die casting, and relates to the technical field of machining.The die casting method comprises the following steps: sealing two ends of a pipe with a cavity and placing the pipe in a cavity of a die casting mold; and pressing molten die casting material into the cavity to obtain a die casting through die casting.The die casting method can improve the bending and torsion resistance and impact resistance of the die casting, so that excessive reinforcing ribs are not needed, thereby improving the problem of mold core fracture in the mold, prolonging the service life of the mold, and reducing the production cost.

Description

Technical Field

[0001] This invention relates to the field of machining technology, and more specifically, to a die-casting method and a die-cast part. Background Technology

[0002] Die castings are pressure-cast parts. Due to the special nature of the casting method, they are generally stronger than castings obtained by conventional casting, making them widely used in automobile manufacturing, photovoltaic energy, and other fields. Die castings are generally manufactured using high-pressure casting, a method that offers advantages such as high production efficiency and high integration, better meeting the needs of mass production. However, die castings obtained through high-pressure casting typically have poor resistance to bending, torsion, and impact. Therefore, to improve the torsional, bending, and impact resistance of die castings, additional design modifications to the die casting process are necessary.

[0003] Currently, die casting generally improves the torsional, bending and impact resistance of die castings by adding multiple reinforcing ribs. However, the increase in reinforcing ribs makes the die casting mold design more complex, increases the number of isolated areas in the mold core, and makes the mold core more prone to breakage during the die casting process, affecting the mold life and increasing production costs. Summary of the Invention

[0004] The present invention aims to solve the problem that current die casting methods are prone to mold core breakage, which affects the mold life.

[0005] To address the above problems, the present invention provides a die-casting molding method, comprising:

[0006] The two ends of the hollow pipe fitting are sealed and placed inside the mold cavity of the die-casting mold;

[0007] Molten die casting material is pressed into the mold cavity, and after die casting, a die casting is obtained.

[0008] Optionally, before sealing both ends of the hollow tube and placing it within the mold cavity of the die-casting mold, the method further includes:

[0009] The die-casting mold is preheated, and a release agent is sprayed onto the cavity surface.

[0010] Optionally, after sealing both ends of the hollow pipe fitting and placing it in the mold cavity of the die-casting mold, before pressing molten die-casting material into the mold cavity and obtaining the die-cast part through die casting, the process further includes:

[0011] The die-casting mold is sealed, and then the air inside the mold cavity is extracted.

[0012] Optionally, after the step of pressing molten die casting material into the mold cavity and obtaining a die casting part by die casting, the process further includes:

[0013] The die-cast part is then subjected to heat treatment.

[0014] Optionally, the die-casting mold includes a cavity and a punch. The bottom surface of the cavity is provided with a downward-facing cavity groove. When the top surface of the punch is connected to the bottom surface of the cavity, the lower opening of the cavity groove is closed by the top surface of the punch to form the mold cavity.

[0015] Optionally, the outer wall of the pipe fitting is provided with a flat surface, and the flat surface is provided with positioning holes;

[0016] A positioning boss is provided on the top surface of the punch, and a positioning plane is provided at the upper end of the positioning boss, and a positioning pin is provided on the positioning plane.

[0017] After the pipe is placed in the mold cavity, the flat surface fits into the positioning plane, and the positioning hole engages with the positioning pin hole.

[0018] Optionally, the locating pin is provided with an air passage extending along the axial direction of the locating pin, one end of the air passage penetrating the upper end face of the locating pin, and the other end penetrating the bottom surface of the punch; and / or,

[0019] The upper edge of the locating pin is chamfered; and / or,

[0020] An overflow-prevention groove is provided on the positioning plane, and the overflow-prevention groove is arranged around the circumference of the positioning pin; and / or,

[0021] The upper end face of the positioning boss is recessed to form multiple reinforcing rib grooves.

[0022] Optionally, before sealing both ends of the hollow tube and placing it within the mold cavity of the die-casting mold, the method further includes:

[0023] The raw material for the pipe fitting is heated and softened, and then extruded and molded to obtain the pipe fitting.

[0024] Optionally, after heating and softening the pipe fitting raw material and then extruding it to obtain the pipe fitting, and before sealing both ends of the hollow pipe fitting and placing it in the mold cavity of the die-casting mold, the method further includes:

[0025] The pipe fitting is bent and shaped.

[0026] The present invention also provides a die-casting part, which is obtained by the die-casting molding method described above.

[0027] Compared with the prior art, the die-casting method provided by the present invention has, but is not limited to, the following technical effects:

[0028] First, the two ends of the hollow pipe fitting are sealed and placed inside the mold cavity of the die-casting mold. For example, the die-casting mold can be opened first, and the pipe fitting can be placed on the punch of the die-casting mold. After positioning, the die-casting mold is closed to place the pipe fitting inside the mold cavity. The pipe fitting inside the mold cavity serves as the basis for the solidification of the die-casting material to form the cavity. Additionally, the pipe fitting is usually open at both ends. The cavity of the pipe fitting can be sealed by, for example, installing end plates or sealing the openings at both ends with the mold. Then, molten die-casting material is pressed into the mold cavity, and through die casting, pressure casting is achieved to obtain the desired die-cast part. In the aforementioned die-casting process, since the mold cavity itself contains a hollow tube with both ends sealed, after the molten die casting material is pressed in, the die casting material quickly surrounds the tube and does not enter the tube's cavity. After the die casting material solidifies, it forms a cavity that matches the shape of the tube. That is, the final die casting contains a hollow tube inside, while a cavity surrounding the tube is formed outside. In this way, the tube and cavity can improve the die casting's resistance to bending and torsion and its impact resistance, eliminating the need for excessive reinforcing ribs. This improves the problem of core breakage inside the mold, increases mold life, and reduces production costs. Attached Figure Description

[0029] Figure 1 This is a schematic flowchart of the die-casting molding method according to an embodiment of the present invention;

[0030] Figure 2 This is a schematic diagram of the die-casting mold when it is opened according to an embodiment of the present invention;

[0031] Figure 3 This is a schematic diagram of the die-casting mold during mold closing according to an embodiment of the present invention;

[0032] Figure 4 This is a schematic diagram of the structure of the die-casting mold when the die-casting die and punch are separated after die-casting is completed, according to an embodiment of the present invention.

[0033] Figure 5 This is a schematic diagram of the structure of the die-cast part obtained after die casting in an embodiment of the present invention;

[0034] Figure 6 This is a schematic diagram of the structure of the die-cast part after material removal according to an embodiment of the present invention;

[0035] Figure 7 for Figure 6 Bottom view of a medium-pressure casting;

[0036] Figure 8This is a schematic diagram of the structure of a die-cast part with a closed cavity according to an embodiment of the present invention;

[0037] Figure 9 for Figure 8 Bottom view of a medium-pressure casting;

[0038] Figure 10 This is a schematic diagram of the pipe fittings according to an embodiment of the present invention;

[0039] Figure 11 This is a schematic diagram of the structure of the punch in the die-casting mold according to an embodiment of the present invention;

[0040] Figure 12 for Figure 11 Enlarged schematic diagram of part A of the middle punch;

[0041] Figure 13 for Figure 11 Enlarged schematic diagram of part B of the middle punch;

[0042] Figure 14 for Figure 9 A cross-sectional view of the locating pin of the middle punch;

[0043] Figure 15 This is a schematic diagram of the structure of a single-cavity cross-section pipe fitting according to an embodiment of the present invention;

[0044] Figure 16 This is a schematic diagram of the structure of a double-cavity cross-section pipe fitting according to an embodiment of the present invention;

[0045] Figure 17 This is a schematic diagram of the structure of the tube fitting with a cavity cross-section according to Embodiment 3 of the present invention;

[0046] Figure 18 This is a schematic diagram of the structure of the four-cavity cross-section pipe fitting according to an embodiment of the present invention;

[0047] Figure 19 This is a schematic diagram of the structure of the tube after extrusion molding according to an embodiment of the present invention;

[0048] Figure 20 This is a schematic diagram of the structure of the tube after bending and forming according to an embodiment of the present invention.

[0049] Explanation of reference numerals in the attached figures:

[0050] 1-pipe fitting, 11-flat surface, 12-locating hole, 21-die, 211-cavity groove, 22-punch, 221-locating boss, 2211-protrusion, 2211a-overflow groove, 2212-locating pin, 2212a-air passage, 2212b-chamfer, 2213-reinforcing rib forming groove, 23-core pulling slider, 3-die casting, 31-reinforcing rib, 32-shaded area. Detailed Implementation

[0051] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0052] In the description of this invention, it should be understood that if the terms "upper", "lower", "front", "rear", "left", and "right" are used, they 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 invention and simplifying the description, and 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. Therefore, they should not be construed as limitations on this invention.

[0053] Furthermore, in the description of this invention, the Z-axis in the accompanying drawings represents the vertical direction, that is, the up and down position, and the positive direction of the Z-axis represents the top, and correspondingly, the negative direction of the Z-axis represents the bottom. It should be noted that the aforementioned representation of the Z-axis is only for the convenience of describing this invention and simplifying the description, and is not intended to 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 of this invention.

[0054] like Figure 1 As shown, an embodiment of the present invention provides a die-casting molding method, the die-casting molding method comprising:

[0055] Step S10: Seal both ends of the tube fitting 1 with the cavity and place it in the mold cavity of the die-casting mold.

[0056] It should be noted that the sealing process can be performed before the pipe is placed into the mold cavity. For example, before placing the pipe into the mold cavity, end plates are installed at both ends of the pipe 1 to seal the pipe 1. The end plates can be installed by welding. The sealing process can also be performed after the pipe is placed into the mold cavity. For example, after placing the pipe into the mold cavity, the openings at both ends of the pipe 1 are sealed by the core-pulling slider 23 of the mold to seal the pipe 1.

[0057] Step S20: Press molten die casting material into the mold cavity, and after die casting, obtain die casting part 3.

[0058] After die casting 3 is obtained, die casting 3 can be kept under pressure in the mold for a period of time, and then the mold can be opened and die casting 3 can be taken out by a robotic arm.

[0059] In this embodiment, the two ends of the hollow pipe fitting 1 are first sealed and placed inside the mold cavity of the die-casting mold. For example, the die-casting mold can be opened first to put it in the open mold state (see details). Figure 2 Then, place the pipe fitting 1 on the punch 22 of the die-casting mold, and after positioning, close the die-casting mold (see details). Figure 3The pipe fitting 1 is placed inside the mold cavity, where it serves as the base for the solidification of the die-casting material to form the cavity. The pipe fitting 1 is typically open at both ends; the cavity can be sealed by, for example, installing end plates or by sealing the openings with the mold. Molten die-casting material is then pressed into the mold cavity, and through die casting, pressure casting is achieved to obtain the desired die-casting part 3 (see details). Figure 4 In the aforementioned die-casting process, since the mold cavity itself contains a hollow tube 1, and both ends of the tube 1 are sealed, after the molten die casting material is pressed in, the die casting material will quickly surround the tube 1 and will not enter the cavity of the tube 1. After the die casting material solidifies, it will form a cavity that matches the shape of the tube 1. That is, the final die casting 3 contains the hollow tube 1 inside, and a cavity surrounding the tube 1 is formed outside the tube 1. In this way, the tube 1 and the cavity can improve the bending and torsional resistance and impact resistance of the die casting 3, so that there is no need to set too many reinforcing ribs 31, thereby improving the problem of mold core breakage inside the mold, increasing mold life, and reducing production costs.

[0060] Optionally, before sealing both ends of the hollow pipe fitting 1 and placing it inside the die-casting mold cavity, the method further includes:

[0061] Step S03: Preheat the die-casting mold and spray a release agent onto the cavity surface.

[0062] It should be noted that mold release agents are conventional processing agents in this field, and their specific types are not limited here.

[0063] In this embodiment, by preheating the mold before inserting the pipe fitting 1, the thermal stress generated after pressing in the molten die casting material can be reduced, thereby improving the mold life. By spraying a release agent in advance, the die casting 3 can be smoothly separated from the mold after molding, ensuring the smoothness of the die casting 3 surface.

[0064] Optionally, after sealing both ends of the hollow pipe fitting 1 and placing it in the mold cavity of the die-casting mold, molten die-casting material is pressed into the mold cavity, and before die-casting to obtain the die-cast part 3, the process further includes:

[0065] Step S11: Seal the die-casting mold and then extract the air from the mold cavity.

[0066] Specifically, the punch 22 and die 21 of the die-casting mold can be closed by a high-pressure vacuum die-casting equipment to provide a sufficiently strong clamping force to seal the mold, and then the air in the mold cavity can be extracted by a vacuum pump.

[0067] If the air in the mold cavity is not removed, the air in the mold cavity will often not have time to be expelled when the die casting material is pressed in, and will be drawn into the die casting material. After solidification, it will form pores in the die casting 3. In this embodiment, by removing the air in the mold cavity, the vacuum degree in the mold cavity is ensured, and the pore defects in the die casting process are reduced.

[0068] Optionally, after pressing molten die-casting material into the mold cavity and obtaining the die-cast part 3 through die casting, the process further includes removing excess material from the die-cast part 3 using a trimming die and a sawing system. The excess material can be, for example,... Figure 5 The material in the shaded area 32 shown ultimately yields the following result: Figure 6 and Figure 7 The die-cast part 3 shown is after the material has been removed.

[0069] Optionally, after pressing molten die casting material into the mold cavity and die casting to obtain die casting part 3, the process further includes:

[0070] Step S30: Heat treat the die-cast part 3.

[0071] There are no restrictions on the specific heat treatment method, which can be annealing, normalizing, quenching, tempering, tempering, aging, etc.

[0072] In this embodiment, heat treatment is performed on the die-cast part 3 formed by die casting. The mechanical properties of the die-cast part 3 can be enhanced by heat treatment according to the actual product needs, so as to meet the differentiated needs of different products.

[0073] Optionally, in conjunction with reference Figure 2 and Figure 4 The die casting mold includes a concave mold 21 and a convex mold 22. The bottom surface of the concave mold 21 is provided with a cavity groove 211 with the opening facing downward. When the top surface of the convex mold 22 is connected to the bottom surface of the concave mold 21, the lower opening of the cavity groove 211 is closed by the top surface of the convex mold 22 to form a mold cavity.

[0074] Specifically, please refer to Figure 2 and Figure 4 The die-casting mold also includes two core-pulling sliders 23. When the two ends of the pipe 1 are sealed by sealing the openings at both ends with the mold, the two core-pulling sliders 23 can be inserted into the openings at both ends of the pipe 1 after the pipe 1 is placed into the mold cavity. At this time, the final die-cast part 3 has an open cavity, that is, the pipe 1 can be seen from the outside of the die-cast part 3.

[0075] In some embodiments, the die-casting mold may not include the core-pulling slider 23. When both ends of the pipe 1 are sealed by mounting end plates, the end plates can be directly installed at the openings at both ends of the pipe 1 before the pipe 1 is placed into the mold cavity. In this case, the final die-cast part 3 has a closed cavity (see...). Figure 8 and Figure 9That is, the pipe fitting 1 is not visible from the outside of the die-cast part 3.

[0076] In this embodiment, the die-casting mold includes a concave mold 21 and a convex mold 22. When die-casting is required, the pipe 1 is placed on the convex mold 22, and then the top surface of the convex mold 22 is connected to the bottom surface of the concave mold 21, which can restrict the pipe 1 in the cavity groove 211, that is, restrict the pipe 1 in the mold cavity. In this way, the structure is simple and the concave mold 21 and the convex mold 22 are easy to close.

[0077] Optionally, refer to Figures 10 to 13 The outer wall of the pipe fitting 1 is provided with a flat surface 11, and the flat surface 11 has a positioning hole 12; the top surface of the punch 22 is provided with a positioning boss 221, the upper end of the positioning boss 221 is provided with a positioning plane, and the positioning plane is provided with a positioning pin 2212; after the pipe fitting 1 is placed in the mold cavity, the flat surface 11 fits with the positioning plane, and the positioning hole 12 matches the pin hole of the positioning pin 2212.

[0078] The upper end of the positioning boss 221 refers to the upper end of the positioning boss 221 in the vertical direction, that is, the upper end of the positioning boss 221 in the attached direction. Figure 2 The positive end of the Z-axis direction is shown. There are various ways to set the positioning plane. For example, the upper surface of the positioning boss 221 can be set as a plane, which can then serve as the positioning plane. Correspondingly, the positioning pin 2212 can be positioned at any location on the upper surface of the positioning boss 221. For another example, see [reference needed]. Figures 11 to 13 Three protrusions 2211 are provided on the upper end of the positioning boss 221. The upper end surfaces of the three protrusions 2211 are all planar and coplanar. Thus, the upper end surfaces of the three protrusions 2211 together constitute the positioning plane. Correspondingly, when setting the positioning pin 2212, the positioning pin 2212 can be respectively set on the upper end surface of one of the protrusions 2211; of course, other forms are also possible, which are not limited here. It should be noted that there is no limitation on the number of positioning holes 12 and positioning pins 2212; there can be one or more. For example, refer to Figures 10 to 12 There are two of each of the positioning pins 12 and 2212.

[0079] In this embodiment, the fitting of the flat surface 11 and the positioning plane, as well as the cooperation of the positioning hole 12 and the positioning pin 2212, are used to position the pipe 1 on the positioning boss 221. The positioning effect is good, and the pipe 1 is not easy to move under the impact of the die casting material, which is conducive to improving the casting quality of the die casting 3.

[0080] Optionally, refer to Figure 14The positioning pin 2212 is provided with an air passage 2212a, which extends along the axial direction of the positioning pin 2212. One end of the air passage 2212a passes through the upper end face of the positioning pin 2212, and the other end passes through the bottom surface of the punch 22. And / or, the edge of the upper end face of the positioning pin 2212 is provided with a chamfer 2212b. And / or, an overflow groove 2211a is provided on the positioning plane, which surrounds the positioning pin 2212 in the circumferential direction. And / or, the upper end face of the positioning boss 221 is recessed to form a plurality of reinforcing rib forming grooves 2213.

[0081] An overflow groove 2211a is provided on the positioning plane. Specifically, the overflow groove 2211a can be provided on the upper end face of the protrusion 2211 where the positioning pin 2212 is located. The reinforcing rib forming groove 2213 refers to the groove used to form the reinforcing rib 31. Specifically, after the die casting material is pressed into the mold cavity, the die casting material can flow into the reinforcing rib forming groove 2213, and after solidification, it can become the reinforcing rib 31 on the die casting 3 (see the section on reinforcing rib 31). Figure 7 and Figure 9 It should be noted that the aforementioned technical features of the air passage 2212a, chamfer 2212b, overflow groove 2211a, and reinforcing rib forming groove 2213 can be selected as one, two, or three, or of course, all at the same time. This invention does not limit this.

[0082] In this embodiment, by providing an air passage 2212a within the positioning pin 2212, the air passage 2212a can, on the one hand, expel some of the air from the pipe 1 before open-cavity die casting (the die-cast part has an open cavity), achieving a high vacuum state within the mold cavity and reducing porosity defects; on the other hand, the air passage 2212a can also serve as an exhaust channel for gas within the mold cavity during closed-cavity die casting (the die-cast part has a closed cavity), reducing the impact of high temperatures on the quality of thermal deformation of the pipe 1 during die casting. A chamfer 2212b is provided on the edge of the upper end face of the positioning pin 2212 to guide the positioning of the pipe 1 to the positioning boss 221, improving operational convenience. By setting an overflow groove 2211a, the main function of the overflow groove 2211a is to avoid gaps that may exist between the flat surface 11 and the positioning plane after they are fitted together. The overflow groove 2211a can collect and block a small amount of die-casting material from entering the pipe fitting 1, thereby increasing the vacuum degree in the mold cavity and improving the die-casting quality. At the same time, the positioning plane is used to fit the flat surface 11 and plays a positioning and sealing role itself. Combined with the overflow groove 2211a, it can further enhance the sealing effect on the pipe fitting 1 and improve the die-casting quality. By setting a reinforcing rib forming groove 2213, it is beneficial to form reinforcing ribs 31 on the surface of the die-casting part 3, thereby improving the strength of the die-casting part 3.

[0083] Optionally, both the pipe fitting 1 and the die casting material are made of aluminum alloy. In this embodiment, by setting both the pipe fitting 1 and the die casting material to aluminum alloy, electrochemical corrosion during die casting can be avoided. Preferably, the pipe fitting 1 is made of 6-series aluminum alloy, also known as aluminum-magnesium-silicon alloy, which has high strength and provides better reinforcement of the strength of the die casting 3.

[0084] Optionally, before sealing both ends of the hollow pipe fitting 1 and placing it inside the die-casting mold cavity, the method further includes:

[0085] Step S01: Heat and soften the raw material of pipe fitting 1, and then perform extrusion molding to obtain pipe fitting 1.

[0086] It should be noted that the cross-sectional shape of the resulting pipe fitting 1 will vary depending on the extrusion die selected for the extrusion molding process. For example, a single-cavity cross-section pipe fitting can be extruded according to requirements (see...). Figure 15 It can also extrude double-cavity cross-section pipe fittings (see...). Figure 16 It can also extrude three-cavity cross-section pipe fittings (see...). Figure 17 Of course, four-cavity cross-section pipe fittings can also be extruded (see...). Figure 18 After step S01, the resulting pipe fitting 1 is in a straight line state (see [reference]). Figure 19 ).

[0087] In this embodiment, the pipe 1 is obtained by heating and softening and then extruding. That is to say, the pipe 1 is an extruded profile. Extruded aluminum profiles have good toughness, are easy to absorb energy, and are more conducive to improving the strength of the die-cast part 3.

[0088] Optionally, after heating and softening the pipe fitting raw material and then extruding it to obtain pipe fitting 1, before sealing both ends of the hollow pipe fitting 1 and placing it in the mold cavity of the die-casting mold, the process further includes:

[0089] Step S02: Bend and shape the pipe fitting 1.

[0090] After step S02, pipe 1 changes from a straight state to a bent state (see [reference]). Figure 20 The bending process can be either two-dimensional planar bending or three-dimensional spatial bending; the specific bending method is not limited here. When the tube 1 is bent in two-dimensional planar form, the envelopment of the component can be avoided, meeting structural design requirements. On the other hand, it can significantly improve the NVH (Noise, Vibration, Harshness) performance of the die-cast part 3 (such as a die-cast subframe). When the tube 1 is bent in three-dimensional spatial form, more complex avoidance requirements can be met for structural design, improving local strength and other properties.

[0091] In this embodiment, by bending and forming the pipe 1, it can be bent and deformed, adapting to various complex die-casting products and having a wide range of applications.

[0092] This invention also provides a die-casting method, the specific steps of which include:

[0093] Step S01: Heat and soften the raw material for the pipe fitting, and then extrude it to obtain pipe fitting 1.

[0094] Step S02: Bend and shape the pipe fitting 1.

[0095] Step S03: Preheat the die-casting mold and spray a release agent onto the cavity surface.

[0096] Step S10: Seal both ends of the hollow pipe fitting 1 and place it in the mold cavity of the die-casting mold. The die-casting mold includes a concave mold 21 and a convex mold 22. The bottom surface of the concave mold 21 is provided with a downward-facing cavity groove 211. When the top surface of the convex mold 22 is connected to the bottom surface of the concave mold 21, the lower opening of the cavity groove 211 is closed by the top surface of the convex mold 22 to form a mold cavity. The outer wall of the pipe fitting 1 is provided with a flat surface 11, and the flat surface 11 has a positioning hole 12. The top surface of the convex mold 22 is provided with a positioning boss 221, the upper end of the positioning boss 221 is provided with a positioning plane, and the positioning plane is provided with a positioning pin 2212. Place the pipe fitting 1 in the mold cavity. Subsequently, the flat surface 11 fits against the positioning plane, and the positioning hole 12 engages with the pin hole of the positioning pin 2212; an air passage 2212a is provided inside the positioning pin 2212, the air passage 2212a extends along the axial direction of the positioning pin 2212, one end of the air passage 2212a passes through the upper end face of the positioning pin 2212, and the other end passes through the bottom surface of the punch 22; a chamfer 2212b is provided on the edge of the upper end face of the positioning pin 2212; an overflow groove 2211a is provided on the positioning plane, and the overflow groove 2211a is arranged around the circumference of the positioning pin 2212; a plurality of reinforcing rib forming grooves 2213 are recessed on the upper end face of the positioning boss 221.

[0097] Step S11: Seal the die-casting mold and then extract the air from the mold cavity.

[0098] Step S20: Press molten die casting material into the mold cavity, and after die casting, obtain die casting part 3.

[0099] Step S30: Heat treat the die-cast part 3.

[0100] In this embodiment, the die-casting method includes two main parts: the first part is the processing of the pipe fitting 1, and the second part is the processing of the die-cast part 3. The first part mainly involves: firstly, extruding the raw material of the pipe fitting 1 to obtain the desired pipe fitting 1, and then further bending the pipe fitting 1 to obtain a bent extruded pipe fitting 1. Thus, the pipe fitting 1 is an extruded profile. Extruded aluminum profiles have good toughness, are easy to absorb energy, and are more conducive to improving the strength of the die-cast part 3. At the same time, the bent shape of the pipe fitting 1 can adapt to various complex die-casting products, and has a wide range of applications. The second part mainly involves: first, preheating the die-casting mold and spraying it with a release agent; then, placing the pipe 1 into the mold cavity of the preheated and release-agent-sprayed die-casting mold; next, sealing the die-casting mold and removing the air from the mold cavity; then, pressing in molten die-casting material to obtain die-casting part 3; and finally, heat-treating die-casting part 3 to obtain the desired die-casting part 3. Thus, because the mold cavity itself contains the hollow pipe 1, and both ends of the pipe 1 are sealed, after the molten die-casting material is pressed in, the die-casting material quickly surrounds the pipe 1 and does not enter the cavity of the pipe 1. After the die-casting material solidifies, it forms a cavity that fits the shape of the pipe 1. That is, the final die-casting part 3 contains the hollow pipe 1 inside, while outside the pipe 1, it forms a cavity. A cavity surrounding the pipe fitting 1 is constructed. Through the pipe fitting 1 and the cavity, the bending, torsional, and impact resistance of the die-cast part 3 can be improved, eliminating the need for excessive reinforcing ribs 31. This improves the problem of core breakage within the mold, increases mold life, and reduces production costs. Simultaneously, preheating the mold reduces thermal stress generated after pressing in the molten die-casting material, further extending mold life. Applying a release agent allows the die-cast part 3 to easily separate from the mold after molding, ensuring a smooth surface. Furthermore, removing air from the mold cavity ensures a vacuum, reducing porosity defects during the die-casting process. Finally, heat treatment enhances the mechanical properties of the die-cast part 3 to meet the differentiated needs of various products.

[0101] This invention also provides a die-casting part, manufactured using the die-casting method described above. The die-casting part can be an instrument panel crossbeam, chassis subframe, front compartment, rear compartment, front longitudinal beam, rear longitudinal beam, battery casing, etc., used in automobile manufacturing. Since this die-casting part is manufactured using the die-casting method described above, it possesses all the beneficial effects of the above embodiments, which will not be elaborated upon further here.

[0102] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "set up" or "equipped with" should be interpreted broadly. For example, it can refer to a fixed connection, a detachable connection, or an integral connection; it can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0103] In the description of this invention, the term "and / or" means three parallel options. Taking "A and / or B" as an example, it includes option A, option B, or an option that satisfies both A and B.

[0104] Furthermore, in the description of this invention, the term "embodiment" refers to a specific feature, structure, material, or characteristic described in connection with that embodiment or implementation that is included in at least one embodiment or implementation of the invention. In this invention, illustrative expressions of the above terms do not necessarily refer to the same embodiment or implementation. Moreover, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or implementations.

[0105] While the present invention has been disclosed above, its scope of protection is not limited thereto. Those skilled in the art can make various changes and modifications without departing from the spirit and scope of the present invention, and all such changes and modifications will fall within the scope of protection of the present invention.

Claims

1. A die-casting molding method, characterized in that, include: The two ends of the hollow pipe fitting (1) are sealed and placed in the mold cavity of the die-casting mold; Molten die casting material is pressed into the mold cavity, and after die casting, a die casting part (3) is obtained; The die casting mold includes a concave mold (21) and a convex mold (22). The bottom surface of the concave mold (21) is provided with a cavity groove (211) with the groove opening facing downward. When the top surface of the convex mold (22) is connected to the bottom surface of the concave mold (21), the lower opening of the cavity groove (211) is closed by the top surface of the convex mold (22) to form the mold cavity. The outer wall of the pipe fitting (1) is provided with a flat surface (11), and the flat surface (11) is provided with a positioning hole (12); the top surface of the punch (22) is provided with a positioning boss (221), the upper end of the positioning boss (221) is provided with a positioning plane, and the positioning plane is provided with a positioning pin (2212); after the pipe fitting (1) is placed in the mold cavity, the flat surface (11) fits against the positioning plane, and the positioning hole (12) engages with the pin hole of the positioning pin (2212); An air passage (2212a) is provided inside the positioning pin (2212). The air passage (2212a) extends along the axial direction of the positioning pin (2212). One end of the air passage (2212a) passes through the upper surface of the positioning pin (2212), and the other end passes through the bottom surface of the punch (22).

2. The die-casting method according to claim 1, characterized in that, Before sealing both ends of the hollow tube (1) and placing it in the mold cavity of the die-casting mold, the method further includes: The die-casting mold is preheated, and a release agent is sprayed onto the cavity surface.

3. The die-casting method according to claim 1, characterized in that, After sealing both ends of the hollow pipe fitting (1) and placing it in the mold cavity of the die-casting mold, before pressing molten die-casting material into the mold cavity and obtaining the die-cast part (3) through die casting, the process further includes: The die-casting mold is sealed, and then the air inside the mold cavity is extracted.

4. The die-casting method according to claim 1, characterized in that, After the molten die casting material is pressed into the mold cavity and die casting is performed to obtain the die casting (3), the process further includes: The die-cast part (3) is heat-treated.

5. The die-casting method according to claim 1, characterized in that, The upper edge of the locating pin (2212) is chamfered (2212b); and / or, An overflow-proof groove (2211a) is provided on the positioning plane, and the overflow-proof groove (2211a) is arranged around the circumference of the positioning pin (2212); and / or, The upper end face of the positioning boss (221) is recessed to form multiple reinforcing rib forming grooves (2213).

6. The die-casting method according to claim 1, characterized in that, Before sealing both ends of the hollow tube (1) and placing it in the mold cavity of the die-casting mold, the method further includes: The raw material for the pipe fitting is heated and softened, and then extruded and molded to obtain the pipe fitting (1).

7. The die-casting method according to claim 6, characterized in that, After heating and softening the pipe fitting raw material and then extruding it to obtain the pipe fitting (1), before sealing both ends of the hollow pipe fitting (1) and placing it in the mold cavity of the die-casting mold, the method further includes: The pipe fitting (1) is bent and shaped.

8. A die-casting part, characterized in that, It is prepared by the die casting method as described in any one of claims 1 to 7.

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