A frame section hot extrusion die

Abstract

The present application relates to the technical field of profile extrusion die, and provides a frame profile hot extrusion die, a lower die is provided with a cavity and a lower feeding belt in the cavity, an upper die is provided with an upper feeding belt inserted into the cavity, the lower feeding belt, the upper feeding belt and the inner wall of the cavity jointly form a hole for forming a profile, the hole has at least two, the lower die is provided with a first air hole, the first air hole is communicated with a first middle air hole, a die cushion is provided with a second middle air hole coaxial with the first middle air hole and communicated with the second middle air hole and a second air hole extending in the radial direction, the inner end of the second air hole is communicated with the second middle air hole, the first air hole, the first middle air hole, the second middle air hole and the second air hole constitute a cooling circuit to cool the corresponding area of the upper feeding belt and the lower feeding belt and the profile passing through the area, so that the surface of the die is kept in a relatively smooth state, the scratches and roughness of the profile surface along the extrusion direction are reduced, and the surface quality is improved.

Description

Technical Field

[0001] This invention relates to the field of profile extrusion die technology, and specifically to a hot extrusion die for frame profiles. Background Technology

[0002] In the hot extrusion process of aluminum profiles, frame profiles are typically formed using hot extrusion dies. During extrusion, an aluminum cast ingot is first fed into the extrusion cylinder for upsetting. Inside the cylinder, the ingot is axially compressed and radially expanded, filling the cylinder's inner cavity. Subsequently, the extrusion press's extrusion rod pushes the upset ingot into the die. The die then divides, welds, and shapes the incoming aluminum billet, ultimately extruding a frame profile with a specific cross-sectional shape.

[0003] Typical hot extrusion dies have a modular structure, mainly consisting of an upper die and a lower die. The upper die, located at the feed end, is responsible for diverting and guiding the aluminum billet. It features diversion bridges that, while bearing the significant extrusion pressure from the extruder, split the aluminum billet entering the die into multiple metal streams. Diversion holes are formed between adjacent diversion bridges, serving as channels for the aluminum billet to enter the die. Each diversion hole guides the diverted metal streams to a welding chamber formed between the upper and lower dies. This welding chamber is the area where the diverted metal streams re-converge and weld together. Under high temperature and pressure, the metal streams are solid-state welded together within the welding chamber to form a unified whole. The lower die, located at the discharge end, contains a die core and forming holes. The die core determines the shape and size of the hollow portion inside the hollow profile. After the welded metal enters the lower mold, it flows around the mold core and gradually envelops the mold core, forming the inner cavity contour of the profile. Then the metal is extruded and shaped through the forming hole, and the profile with the final cross-sectional shape is extruded.

[0004] During the hot extrusion process, after a period of use, the surface quality of the extruded frame profiles deteriorates. Scratches and rough bands appear on the profile surface extending along the extrusion direction, reducing surface smoothness and affecting product appearance and the adhesion of subsequent surface treatment processes. As production continues, the scratches and roughness on the profile surface gradually worsen, leading to a progressively higher scrap rate. This necessitates frequent shutdowns for mold repair or replacement, impacting production efficiency. Summary of the Invention

[0005] To overcome the above-mentioned defects, embodiments of the present invention provide a hot extrusion die for frame profiles, which solves the technical problem in the related art that the surface quality of the extruded frame profiles is rough and not smooth enough due to factors such as die surface wear, resulting in a high scrap rate.

[0006] At least one embodiment of the present invention provides a hot extrusion die for a frame profile, comprising: a die pad, a lower die, and an upper die, characterized in that the lower die has a cavity and is provided with a lower feed strip located in the cavity, the upper die has an upper feed strip inserted into the cavity, the lower feed strip, the upper feed strip, and the inner wall of the cavity together enclose to form a die hole for forming the profile, and the die hole has at least two. The lower mold has an axially extending first central air hole and several radially extending first ventilation holes. The inner end of each first ventilation hole is connected to the first central air hole, and each first ventilation hole is located between two adjacent holes. The mold pad has a second central air hole that is coaxial with and connected to the first central air hole, and a second vent hole that extends radially. The inner end of the second vent hole is connected to the second central air hole. The first vent hole, the first central air hole, the second central air hole, and the second vent hole are used to introduce cooling gas and form a cooling circuit to cool and reduce the temperature of the profile passing through the upper and lower feed belt areas.

[0007] According to one embodiment of this application, the first vent is located on the side of the lower feed belt away from the upper mold.

[0008] According to one embodiment of this application, the outlet end of the second vent is connected to the inlet end of the second middle vent, and the inlet end of the first vent is connected to the outlet end of the first middle vent. The second vent can introduce cooling air, so that the cooling air flows along the second middle vent and the first middle vent in the opposite direction to the profile forming movement, and cools the inner wall of the duct, the outer peripheral wall of the upper feed belt, the outer peripheral wall of the lower feed belt, and the profile passing through the duct before being discharged from the first vent.

[0009] According to one embodiment of this application, the shaped hole has five holes, and the number of first vent holes is the same as the number of shaped holes, and the two are arranged at intervals along the circumference, so that a first vent hole is arranged between any two adjacent shaped holes.

[0010] According to one embodiment of this application, the first central air hole is eccentrically arranged relative to the lower mold, and the second central air hole is eccentrically arranged relative to the mold pad.

[0011] According to one embodiment of this application, there are two second vent holes, both of which are connected to the second central vent hole. The main axes of the two second vent holes are arranged at an obtuse angle or a flat angle. The two second vent holes are used to simultaneously or selectively introduce cooling gas into the second central vent hole.

[0012] According to one embodiment of this application, each of the two second vent holes has an installation groove at its air inlet end, one of which has a sealing component, and the other second vent hole is used to introduce cooling air into the second central vent hole.

[0013] According to one embodiment provided in this application, the aperture of the first central vent is the same as that of the second central vent, the aperture of the first vent is the same as that of the second vent, and the aperture of the first vent is larger than that of the first vent.

[0014] According to one embodiment of this application, the lower mold has a temperature measuring hole located on the side of the first vent hole away from the upper mold. The temperature measuring hole extends radially and is equipped with a temperature measuring element for detecting the center temperature of the lower mold.

[0015] According to one embodiment of this application, the lower mold spindle is arranged in a horizontal direction, the first central air hole is lower than the lower mold spindle, the temperature measuring hole is higher than the lower mold spindle, and extends from top to bottom close to the center of the lower mold.

[0016] This invention provides a hot extrusion die for frame profiles. Compared with existing technologies, the cooling airflow flows directly through the internal channels of the die body, exchanging heat with the die body first to cool it down. After the die body temperature drops, the profile is indirectly cooled through heat transfer via contact between the die body and the profile. The temperature of the profile flowing through the die orifice can be reduced by about 10°C from approximately 520°C to 530°C. This temperature reduction lessens the high-temperature softening of the die forming surface, slows down the decay of surface hardness, maintains the die surface's ability to resist metal flow shear stress, reduces the die surface wear rate, and decreases the increase in surface roughness. The die surface remains relatively smooth, reducing the cutting and ploughing effects on the flowing metal, decreasing scratches and rough bands on the profile surface along the extrusion direction, improving the profile surface finish, and reducing the scrap rate. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 This is a schematic diagram of the structure of a hot extrusion die for a frame profile provided in an embodiment of the present invention; Figure 2 This is an embodiment of the present invention. Figure 1 Internal cross-sectional structural diagram; Figure 3 This is an embodiment of the present invention. Figure 1 A schematic diagram of the structure of the lower mold and mold pad; Figure 4 This is an embodiment of the present invention. Figure 1 Schematic diagram of the right view structure of the lower and middle mold; Figure 5 This is an embodiment of the present invention. Figure 1 A schematic diagram of the structure of the lower mold and the mold pad.

[0019] In the diagram: 110, lower mold; 111, first central air hole; 112, first vent hole; 113, temperature measuring hole; 114, lower feed belt; 115, cavity; 120. Mold pad; 121. Second central air hole; 122. Second vent hole; 123. Mounting groove; 130. Upper mold; 131. Upper feed belt; 140. Sealing component; 150. Hole. Detailed Implementation To make the objectives, technical solutions, and advantages of this application clearer, the technical solutions in the embodiments of this application will be described in more detail below with reference to the accompanying drawings. In the drawings, the same or similar reference numerals denote the same or similar components or components having the same or similar functions throughout. The described embodiments are some, but not all, embodiments of this application. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain this application, and should not be construed as limiting this application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application.

[0020] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, an indirect connection through an intermediate medium, or the internal communication between two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0021] In the description of this application, it should be understood that the terms "upper", "lower", "front", "rear", "left", "right", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this application 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 application.

[0022] The terms "first," "second," "third," "fourth," etc., used in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of this application described herein can be implemented, for example, in a sequence other than those illustrated or described herein.

[0023] To make the drawings concise and easy to understand, some drawings only show one of the components with the same structure or function, or only one of them is marked. In this article, "one" not only means "only one", but can also mean "more than one", and "several" includes "two" and "more than two".

[0024] Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover a non-exclusive inclusion. For example, a process, method, system, product, or apparatus that includes a series of steps or units is not necessarily limited to those explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus. It is understood that the specific embodiments described herein are merely illustrative of the invention and not intended to limit it. The embodiments of this application are described in detail below with reference to the accompanying drawings.

[0025] This example relates to the field of aluminum profile hot extrusion die technology, specifically to a frame profile hot extrusion die. In the aluminum profile hot extrusion process, frame profiles are typically formed using hot extrusion dies. During extrusion, an aluminum cast ingot is first fed into the extrusion cylinder for upsetting. Inside the cylinder, the ingot is axially compressed and radially expanded, filling the cylinder's inner cavity. Subsequently, the extrusion press's extrusion rod pushes the upset ingot into the die. The die divides, welds, and shapes the incoming aluminum billet, ultimately extruding a frame profile with a specific cross-sectional shape. During hot extrusion, the heating temperature of the aluminum cast ingot is generally between 410°C and 430°C, while the die's heating temperature is around 480°C. The aluminum cast ingot undergoes plastic deformation during upsetting in the extrusion cylinder. As the extrusion rod pushes the ingot through the die's internal channels, the metal experiences intense shear deformation and friction under high pressure. This deformation work is converted into heat, further increasing the temperature of the aluminum billet. The temperature of the aluminum billet passing through the die's 150mm orifice can reach approximately 520°C to 530°C.

[0026] Under high-temperature conditions of 520℃ to 530℃, the inner wall of the die cavity 150, the outer peripheral wall of the upper feed belt 131, and the outer peripheral wall of the lower feed belt 114 are in direct contact with high-temperature metal for extended periods. Taking H13 die steel, a commonly used die material, as an example, the surface hardness of H13 steel decreases in high-temperature environments above 500℃. The die forming surface, in a softened state at high temperatures, weakens its ability to resist the shear stress of metal flow. Under extrusion pressure, the high-temperature metal continuously flows through the forming surfaces of the die cavity 150, the upper feed belt 131, and the lower feed belt 114, resulting in a high relative sliding velocity between the metal and the die surface. With the die surface already softened at high temperatures, the metal flow exerts a continuous frictional shearing effect on the die surface, causing the die surface material to gradually peel off in the form of tiny particles, leading to a gradual increase in surface roughness. When the formed profile passes through the roughened die hole 150, tiny protrusions on the inner wall of the die hole 150, the outer peripheral wall of the upper feed belt 131, and the outer peripheral wall of the lower feed belt 114 will embed into the profile surface. During the relative sliding process between the profile and the die surface, these protrusions will produce cutting and ploughing effects on the profile surface, forming scratches and rough bands extending along the extrusion direction on the profile surface.

[0027] Meanwhile, as the surface roughness of the mold increases, the frictional resistance experienced by the metal flowing within the orifice 150 also increases. Due to inconsistent wear on the mold surface across different areas of the orifice 150, the uneven distribution of frictional resistance leads to variations in metal flow velocity across these areas. Areas with faster flow velocities have a relatively abundant metal supply, while areas with slower flow velocities have a relatively insufficient metal supply. Irregular surface undulations and texture differences occur on the profile surface at the boundary between fast and slow flow velocities, further affecting the profile's surface finish. This decreased surface finish affects the product's appearance and the adhesion of subsequent surface treatment processes. Furthermore, the increased wear and roughness of the mold forming surface at high temperatures results in a rough and less smooth surface quality of the extruded frame profile, leading to a higher scrap rate.

[0028] To address the aforementioned surface quality issues of profiles caused by high temperatures, conventional cooling methods each have their limitations. One method is water cooling, which involves creating water-cooling channels inside the mold and circulating cooling water for cooling. While water cooling is effective at removing heat when the mold temperature is relatively low, in hot extrusion molds, the mold temperature is approximately 480°C, and the aluminum billet temperature can reach 520°C to 530°C during profile forming. At these temperatures, water will rapidly vaporize, causing the cooling water in the water-cooling channels to boil and generate steam. The rapid expansion of the steam volume leads to drastic pressure fluctuations within the channels, resulting not only in unstable cooling but also the potential for localized thermal stress concentration and cracking in the mold. Once the mold cracks, periodic raised edges or dents will appear on the profile surface, leading to product scrap. Furthermore, there is a high risk of water leakage. If cooling water seeps into the mold cavity, it will react violently with the high-temperature molten aluminum, forming pores and cracks on the profile surface, affecting surface quality and creating safety hazards. Another approach is external air cooling, which involves installing fans or compressed air nozzles outside the mold to blow cooling airflow onto the outer surface. While external air cooling is structurally simple, heat transfer from the inside of the mold to the outer surface requires a long heat conduction path, making it difficult to effectively reduce the temperature in areas close to the cavity 115 inside the mold. The external cooling airflow can only remove heat from the outer surface of the mold. For critical forming areas located deep inside the mold, such as the die hole 150, the lower feed belt 114, and the upper feed belt 131, the excessively long heat transfer path of external air cooling results in a delayed cooling response and an inability to effectively control the internal temperature of the mold. When the internal temperature of the mold remains consistently high, the softening and wear problems of the mold forming surface at high temperatures cannot be alleviated, and scratches and rough bands on the profile surface caused by the roughness of the mold surface are difficult to improve, leading to a persistently high scrap rate.

[0029] To address the aforementioned issues, this example provides a hot extrusion die for a frame profile. By constructing a cooling airflow circuit between the lower die 110 and the die pad 120, the cooling medium is directly delivered to the internal region near the die hole 150, the lower feed belt 114, and the upper feed belt 131, shortening the heat conduction path and achieving timely control of the die's internal temperature. Specifically, as shown... Figure 1 , Figure 2 and Figure 5As shown, the hot extrusion die for the frame profile includes a die pad 120, a lower die 110, and an upper die 130. The lower die 110 has a cavity 115, within which a lower feed strip 114 is installed. It should be noted that the cavity 115 here includes the axial region corresponding to the orifice 150 and the region downstream of the orifice 150, also referred to as the empty space. For ease of understanding, these are collectively referred to as cavity 115. Similarly, the empty space on the die pad 120 can also be called cavity 115. The upper die 130 has an upper feed strip 131 inserted into the cavity 115. Both the lower feed strip 114 and the upper feed strip 131 are solid structures with specific cross-sectional shapes. The upper surface and side surfaces of the lower feed strip 114 and the lower surface and side surfaces of the upper feed strip 131, together with the inner wall of the cavity 115, form the orifice 150. The cross-sectional shape of the orifice 150 determines the cross-sectional profile of the extruded profile. The shaped hole 150 has at least two holes. Preferably, the shaped hole 150 is eccentrically arranged relative to the lower mold 110, that is, the shaped hole 150 is not located on the central axis of the lower mold 110, but is arranged to one side, so as to leave space in the central area of ​​the lower mold 110 and the mold pad 120 to arrange cooling airflow channels.

[0030] like Figure 2 and Figure 5 As shown, the lower mold 110 has a first central vent 111 extending axially in its center. The mold pad 120 has a second central vent 121 in its center, which is coaxial with and communicates with the first central vent 111. The lower mold 110 also has several first vent holes 112 extending radially, the inner end of which communicates with the first central vent 111, and each first vent hole 112 is located between two adjacent holes 150. The mold pad 120 also has a second vent hole 122 extending radially, the inner end of which communicates with the second central vent hole 121. The first vent hole 112, the first central vent 111, the second central vent 121, and the second vent hole 122 together constitute a cooling airflow circuit. Preferably, room temperature air is used as the cooling gas. During the extrusion process, cooling gas is introduced through the second vent 122, flows along the second central vent 121, passes through the first central vent 111, and is discharged through the first vent 112, or flows in the opposite direction. During the flow, the cooling gas undergoes convective heat exchange with the inner walls of the channels in the central region of the lower die 110 and the die pad 120. Heat is transferred from the lower die 110 and the die pad 120 to the cooling gas and carried away, reducing the temperature in the central region of the lower die 110 and the die pad 120. This heat is then conducted through the lower die 110 and the die pad 120, cooling the inner wall of the orifice 150, the outer peripheral wall of the lower feed belt 114, the outer peripheral wall of the upper feed belt 131, and the profile flowing through the orifice 150.

[0031] In summary, the cooling airflow flows directly through the internal channels of the lower die 110 and die pad 120, exchanging heat with them to cool them down. After the lower die 110 and die pad 120 are cooled, the profile is indirectly cooled through heat transfer between them and the profile. The profile temperature as it flows through the orifice 150 can decrease by approximately 10°C from about 520°C to 530°C. This temperature reduction lessens the high-temperature softening of the die forming surface, slows the decay of the surface hardness of H13 steel, maintains the die surface's ability to resist metal flow shear stress, reduces the die surface wear rate, and decreases the increase in surface roughness. The die surface remains relatively smooth, reducing the cutting and ploughing effects on the flowing metal, decreasing scratches and rough bands on the profile surface along the extrusion direction, improving the profile surface finish, and reducing the scrap rate.

[0032] Compared to water cooling, this solution uses gas as the cooling medium, eliminating the risks of pressure fluctuations and leaks caused by liquid vaporization at high temperatures. It also prevents defects such as raised edges, dents, or pores from forming on the profile surface due to mold cracking or water leakage. The cooling process has no negative impact on the profile surface quality. In water cooling, the water flow channel needs to be completely sealed to prevent leakage, and the sealing structure is prone to failure under high temperature and high pressure conditions. Gas cooling circuits, on the other hand, have relatively lower requirements for sealing; even with minor gaps, gas leakage will not damage the profile or mold. Furthermore, directly converting water cooling channels to ventilation presents a contradiction between structural strength and cooling effect. Water cooling channels are typically densely arranged circumferentially and axially around the 150mm orifice, with a small cross-sectional size and a large number of channels to increase water flow velocity and improve the heat transfer coefficient. However, gas density is much lower than water, resulting in a smaller mass flow rate for the same cross-section, limiting the amount of heat removed per unit time, and making the cooling effect far inferior to water. To improve the air cooling effect, the cross-sectional area of ​​the channel needs to be increased to increase the gas flow rate. However, expanding the water cooling channel around the cavity 150 in the circumferential direction will directly weaken the wall thickness of the supporting structure around the cavity 115. This area is where the extrusion pressure is concentrated, and the thinning of the wall thickness will cause the mold to deform or crack under the extrusion pressure.

[0033] In this example, the first central vent 111 and the second central vent 121 are respectively located in the central areas of the lower die 110 and the die pad 120, rather than arranged circumferentially around the orifice 150. The central areas of the lower die 110 and the die pad 120 experience relatively low stress during extrusion because the orifice 150 is eccentrically located on the periphery of the lower die 110. The extrusion pressure is primarily borne by the die material surrounding the orifice 150, with the central area being a low-stress region. Placing the large-diameter central vents in the central low-stress region allows the utilization of this region's low stress, ensuring that a larger orifice diameter is not significantly weakened in terms of the overall load-bearing capacity of the die. Cooling airflow flows through the central vents in the central area, exchanging heat with the die material, and then indirectly cooling the forming surface of the orifice 150 region through heat conduction. This achieves spatial separation between the cooling airflow channel and the load-bearing structure. The load-bearing body maintains a complete wall thickness around the orifice 150, while the cooling channel is arranged with a larger cross-section in the central low-stress region. Both are independent, balancing cooling effect and structural strength.

[0034] Compared with external air cooling, the first vent 112, the first central vent 111, the second central vent 121, and the second vent 122 of this solution are all located inside the lower mold 110 and the mold pad 120. The cooling gas flows directly through the area inside the mold near the die hole 150, the lower feed belt 114, and the upper feed belt 131. The heat conduction path is shorter, the cooling response is more timely, and it can directly cool down the high-temperature area inside the mold. It controls the high-temperature softening, wear, and roughness increase of the mold forming surface from the source of heat generation, and the improvement effect on the surface quality of the profile is more obvious.

[0035] In further examples, such as Figure 2 As shown, the first vent 112 is located on the side of the cavity 115 away from the upper die 130, and is axially spaced from the cavity 115. The cavity 115 region bears significant extrusion pressure during the extrusion process, and the wall of the cavity 115 needs to maintain sufficient thickness to ensure the stability of the cross-sectional shape of the bore 150. If the first vent 112 is extended axially to the same position as the bore 150, the wall thickness between the first vent 112 and the cavity 115 will be thinned. Under significant extrusion pressure, this thin-walled area may deform, causing a change in the cross-sectional shape of the bore 150 and affecting the dimensional accuracy of the profile. By axially spacing the first vent 112 from the cavity 115, it is ensured that the cavity 115 is surrounded by complete die material support, the cross-sectional shape of the bore 150 remains stable during extrusion, and the dimensional accuracy and surface flatness of the extruded profile are maintained.

[0036] In further examples, such as Figure 2 and Figure 5As shown, the outlet of the second vent 122 is connected to the inlet of the second central vent 121, and the inlet of the first vent 112 is connected to the outlet of the first central vent 111. Cooling air enters through the second vent 122 and flows along the second central vent 121 and the first central vent 111 in the opposite direction to the profile forming movement. The cooling air first flows through the second central vent 121, where the temperature is relatively low, creating a large temperature difference with the mold material in the mold pad 120 area, effectively removing heat from the mold pad 120 area. The cooling air continues to flow towards the first central vent 111, absorbing heat from the central area of ​​the lower mold 110 and gradually heating up. By the time it reaches the first vent 112, the temperature has increased, and the air is discharged from the first vent 112.

[0037] Because the cooling channel extends from the second central vent 121 of the mold pad 120 to the first central vent 111 and the first vent 112 of the lower mold 110, the cooling air exchanges heat with the mold pad 120 and the lower mold 110 successively during the flow process, and both the mold pad 120 and the lower mold 110 are cooled. The temperature distribution of the mold pad 120 and the lower mold 110 in the axial direction is relatively uniform, and the cross-sectional shape of the cavity 150 maintains a relatively uniform size in the axial direction. The flow cross-section of the metal in the cavity 150 changes little, the variable of metal flow is small, and the flow velocity distribution along the axial direction is relatively stable. This means that the metal in the cavity 150 will not experience local acceleration or deceleration due to sudden changes in cross-section size. The flow trajectory of each metal particle is relatively regular, and the shearing action of the mold surface on each area of ​​the profile surface is relatively uniform. The profile surface is less prone to local roughness differences caused by uneven flow. Therefore, the cooling channel runs through the mold pad 120 and the lower mold 110. By uniformly cooling the lower mold 110 and the mold pad 120, the temperature difference and thermal expansion difference in the axial direction of the hole 150 are reduced, the flow variables of the metal in the hole 150 are reduced, and the surface quality of the profile is improved.

[0038] In further examples, such as Figure 1 , Figure 3 and Figure 4As shown, the number of orifices 150 can be five. The number of first vent holes 112 is the same as the number of orifices 150, and they are arranged circumferentially at intervals. The five orifices 150 are evenly or non-uniformly distributed circumferentially, and each first vent hole 112 is correspondingly set on one side of the circumferential direction of an orifice 150. Since the first vent holes 112 are arranged circumferentially at intervals, there is a first vent hole 112 between any two adjacent orifices 150, that is, there are cooling airflow channels on both sides of each orifice 150, so that each orifice 150 can obtain cooling effect from both sides, and the temperature distribution of the mold forming surface in each orifice 150 tends to be uniform. The uniform temperature of the mold forming surface in each orifice 150 makes the flow resistance of the metal in each orifice 150 similar, the metal flow rate uniform, and the exit speed of each profile consistent. The profile surface will not produce waves or bending deformation due to the difference in flow rate. The consistency of product surface quality is improved and the scrap rate is reduced during multi-cavity extrusion.

[0039] In further examples, such as Figure 2 , Figure 4 and Figure 5 As shown, the lower mold 110 also has a radially extending temperature measuring hole 113. The temperature measuring hole 113 is located on the side of the first vent 112 away from the cavity 115, and the bottom of the temperature measuring hole 113 extends to a position close to the axis of the lower mold 110. A temperature measuring element, such as a thermocouple, can be inserted into the temperature measuring hole 113. The measuring end of the thermocouple contacts the bottom of the temperature measuring hole 113, and the lead of the thermocouple is led out from the opening of the temperature measuring hole 113 and connected to an external temperature display instrument or control system. The center temperature of the lower mold 110 is monitored in real time through the thermocouple. The operator can adjust the flow rate and pressure of the cooling air according to the temperature data fed back by the temperature measuring hole 113 to maintain the mold temperature within a reasonable range. Controlling the mold temperature within a reasonable range can avoid the surface roughness of the profile caused by the high temperature softening and accelerated wear of the mold forming surface when the temperature is too high, and can also avoid defects such as cold shuts or insufficient filling on the profile surface caused by the reduced metal fluidity when the temperature is too low. Thus, the stability of the profile surface quality is ensured through temperature monitoring and adjustment.

[0040] In further examples, such as Figure 4 and Figure 5As shown, in the vertically positioned state of the lower mold 110 and mold pad 120, the temperature measuring hole 113 is located on the upper side of the axis of the lower mold 110 and mold pad 120. The temperature measuring hole 113 extends radially from top to bottom, close to the center of the lower mold 110 and mold pad 120, and the bottom of the temperature measuring hole 113 is eccentrically upward relative to the axis. The first central air hole 111 and the second central air hole 121 are offset on the lower side of the axis, that is, eccentrically downward relative to the axis. The temperature measuring hole 113 and the central air hole are located on the upper and lower sides of the axis, respectively. The temperature measuring hole 113 extends from top to bottom, and its bottom end is close to the center of the lower mold 110 and mold pad 120. The detected temperature can reflect the true thermal state of the central area of ​​the mold, providing a basis for adjusting the cooling airflow parameters. Accurate temperature detection allows operators to adjust the cooling airflow parameters in a timely manner according to the actual working conditions, avoiding fluctuations in the surface quality of the profile caused by the temperature of the mold forming surface deviating from the reasonable range, and effectively controlling the scrap rate.

[0041] In further examples, such as Figure 5As shown, to adapt to different cooling requirements, there are two second vent holes 122, both of which are connected to the second central vent hole 121. Both second vent holes 122 can supply cooling air to the second central vent hole 121. By adjusting the air intake ratio of the two vent holes, the airflow rate and velocity distribution within the second central vent hole 121 can be controlled. When a larger cooling air flow is required, both second vent holes 122 supply air simultaneously; when a smaller cooling air flow is required, only one vent hole can be used. This flexible adjustment of the air intake allows the mold temperature to be adaptively adjusted according to changes in parameters such as profile specifications and extrusion speed. The temperature of the mold forming surface can be controlled within a reasonable range under different production conditions, ensuring the consistency of the profile surface quality. Furthermore, the two second vent holes 122 are arranged at an obtuse or flat angle along the circumference, and each second vent hole 122 has an installation groove 123 at its inlet. A sealing element 140, such as a plug, can be installed in the mounting slot 123 to seal one of the second vent holes 122, allowing cooling air to be supplied to the second central vent hole 121 only through the other second vent hole 122. This arrangement accommodates the layout differences of different extrusion presses. In actual production workshops, extrusion presses are divided into left and right machines based on their operating side position; the operating side is the work surface for operators to control the equipment, adjust parameters, and connect pipelines. One of the second vent holes 122 of the die pad 120 is connected to an external compressed air pipeline, which supplies cooling gas to the second vent hole 122. The compressed air pipeline is usually fixed on the operating side for easy connection and maintenance by the operator. The two second vent holes 122 are arranged at an obtuse angle along the circumference so that when one vent hole is on one side, the other vent hole can be on the other side. When the mold is installed on the left extruder, the compressed air pipeline interface is located on the left side of the mold. The second vent hole 122 on the left side can be connected to the air source pipeline, and bolts are installed in the mounting groove 123 of the second vent hole 122 on the right side to seal it. When the same mold is transferred to the right extruder, the compressed air pipeline interface is located on the right side of the mold. The second vent hole 122 on the right side is connected to the air source pipeline, and the second vent hole 122 on the left side is sealed. Through the cooperation of the two second vent holes 122 and the mounting groove 123, a set of molds can be used on both left-hand and right-hand extruders without structural modification or re-drilling. This reduces the cost of configuring multiple sets of molds due to different machine layouts and improves the convenience of mold transfer between different machines. The universality of the cooling system ensures that the mold can be properly connected to the cooling airflow on different machines, and the temperature control of the mold forming surface remains consistent on different machines. The improvement effect on the surface quality of the profile is not affected by the type of machine.

[0042] In further examples, such as Figure 5As shown, the diameter of the first central vent 111 is the same as that of the second central vent 121, and the diameters of the first vent 112 and the second vent 122 are the same. The diameter of the first central vent 111 is larger than that of the first vent 112. The central vents serve as the main channel for cooling airflow, with the gas flowing a relatively long path axially. The larger vent diameter reduces the frictional resistance of the gas during long-distance flow, ensuring sufficient cooling airflow. With ample cooling airflow, the mass of gas flowing through the central area of ​​the mold per unit time is larger, carrying away more heat from the mold's interior. This results in better temperature control of the mold forming surface, more significant suppression of high-temperature softening, wear, and roughness increase on the mold forming surface, and more substantial improvement in the profile surface quality. The vents, as the inlet and outlet of the airflow, have a shorter flow path within them. A suitable vent diameter allows for maintaining a suitable gas flow rate while minimizing weakening of the mold's structural strength. The central vent and air passages each have the same diameter, and the cross-section of the airflow channel is uniform along both the axial and circumferential directions. This prevents the formation of localized vortex zones due to sudden expansion or contraction of the cross-section during gas flow. Gas particles within the vortex zone undergo irregular backflow motion, consuming energy without participating in effective heat exchange. The uniform cross-section helps maintain a stable airflow, ensuring consistent heat exchange efficiency along the entire channel length. This further reduces the temperature difference on the die forming surface corresponding to each type of orifice (150), improves the consistency of metal flow velocity across all orifices (150), and further enhances the consistency of profile surface quality and yield during multi-cavity extrusion.

[0043] The above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application, and should all be included within the protection scope of this application.

Claims

1. A hot extrusion die for a frame profile, comprising a die pad (120), a lower die (110), and an upper die (130), characterized in that, The lower mold (110) has a cavity (115) and a lower feed strip (114) located in the cavity (115). The upper mold (130) has an upper feed strip (131) inserted into the cavity (115). The lower feed strip (114), the upper feed strip (131) and the inner wall of the cavity (115) together form a profile hole (150) for forming a profile. The profile hole (150) has at least two holes. The lower mold (110) has an axially extending first central air hole (111) and a plurality of radially extending first ventilation holes (112). The inner end of each first ventilation hole (112) is connected to the first central air hole (111), and each first ventilation hole (112) is located between two adjacent holes (150). The mold pad (120) has a second central air hole (121) coaxial with and connected to the first central air hole (111) and a second vent hole (122) extending radially. The inner end of the second vent hole (122) is connected to the second central air hole (121). The first vent hole (112), the first central air hole (111), the second central air hole (121) and the second vent hole (122) are used to introduce cooling gas and form a cooling circuit to cool the inner wall of the hole (150), the outer peripheral wall of the lower feed belt (114), the outer peripheral wall of the upper feed belt (131) and the profile flowing through the hole (150).

2. The hot extrusion die for a frame profile according to claim 1, characterized in that, The first vent (112) is located on the side of the lower feed belt (114) away from the upper mold (130).

3. The hot extrusion die for a frame profile according to claim 2, characterized in that, The outlet end of the second vent (122) is connected to the inlet end of the second central vent (121), and the inlet end of the first vent (112) is connected to the outlet end of the first central vent (111). The second vent (122) can introduce cooling air, so that the cooling air flows along the second central vent (121) and the first central vent (111) in the opposite direction to the profile forming movement, and cools the inner wall of the hole (150), the outer peripheral wall of the upper feeding belt (131), the outer peripheral wall of the lower feeding belt (114) and the profile passing through the hole (150) before being discharged from the first vent (112).

4. The hot extrusion die for a frame profile according to claim 3, characterized in that, The shaped hole (150) has five holes, and the number of the first vent hole (112) is the same as that of the shaped hole (150), and the two are arranged at intervals along the circumference, so that a first vent hole (112) is arranged between any two adjacent shaped holes (150).

5. The hot extrusion die for a frame profile according to claim 4, characterized in that, The first central air hole (111) is eccentrically arranged relative to the lower mold (110), and the second central air hole (121) is eccentrically arranged relative to the mold pad (120).

6. The hot extrusion die for a frame profile according to claim 3, characterized in that, The second vent (122) has two holes, both of which are connected to the second central vent (121). The main axes of the two second vents (122) are arranged at an obtuse angle or a flat angle. The two second vents (122) are used to simultaneously or selectively introduce cooling gas into the second central vent (121).

7. The hot extrusion die for a frame profile according to claim 6, characterized in that, The air inlet ends of the two second vent holes (122) are provided with mounting grooves (123), one of the mounting grooves (123) is provided with a sealing element (140), and the other second vent hole (122) is used to introduce cooling air into the second central vent hole (121).

8. The hot extrusion die for a frame profile according to claim 5, characterized in that, The diameter of the first central vent (111) is the same as that of the second central vent (121), the diameter of the first vent (112) is the same as that of the second vent (122), and the diameter of the first central vent (111) is larger than that of the first vent (112).

9. A hot extrusion die for a frame profile according to claim 5, characterized in that, The lower mold (110) has a temperature measuring hole (113) located on the side away from the upper mold (130) from the first vent hole (112). The temperature measuring hole (113) extends radially and is provided with a temperature measuring element for detecting the center temperature of the lower mold (110).

10. A hot extrusion die for a frame profile according to claim 9, characterized in that, The main shaft of the lower mold (110) is arranged in a horizontal direction. The first central air hole (111) is lower than the main shaft of the lower mold (110), and the temperature measuring hole (113) is higher than the main shaft of the lower mold (110) and extends from top to bottom close to the center of the lower mold (110).

Images