Extrusion die
By adding a pre-deformed cavity inside the mold and controlling the metal flow rate, the problem of flow difference in the mold during the production of metal fin profiles was solved, achieving high precision and uniformity of microstructure and properties of the profiles, and meeting the high-quality requirements of aerospace aluminum alloy profiles.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-04-08
- Publication Date
- 2026-03-20
AI Technical Summary
Existing molds have the problem of large differences in the extruded metal flow in different parts when producing metal fin profiles, which leads to greater differences in microstructure and properties, making it difficult to meet the high precision and high surface quality requirements of aluminum alloy profiles for aerospace applications.
By adding a pre-deformation cavity inside the mold and adjusting the metal flow rate of the bar stock, the difference in metal flow rate in different parts can be reduced. The ratio of the projected area of the pre-deformation cavity and the centerline spacing of the shaped cavity are designed to improve the dimensional accuracy and uniformity of the profile.
By regulating the metal flow rate, the dimensional accuracy control of the metal fin profile and the uniformity of the microstructure properties of each part were improved, thereby increasing the production efficiency of the mold and the quality of the profile.
Smart Images
Figure CN224010840U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The utility model relates to the mould design technical field, more specifically, relate to a kind of extrusion dies. BACKGROUND
[0002] With the progress of science and technology, the development trend of aluminum alloy profiles for aerospace is high-precision size, complex cross-sectional shape, high surface quality and high organizational uniformity.
[0003] In prior art, mould design mainly relies on production experience, different alloys, different cross-sectional sizes, different size shrinkage rates are determined based on experience parameter range, new mould is tested after trial, and then repaired according to actual production conditions, some moulds cannot be repaired after one-time trial or multiple iteration repair trial, resulting in mould scrap, the current one-time machine qualification rate of mould for high-precision, complex cross-section profile is very low, which cannot meet the requirements of high-precision, high-performance and high-surface quality of current aluminum alloy profiles for aerospace.
[0004] For example Figure 1 As shown in the fin profile for aerospace, comprising main body part 1 and fin part, wherein the fin part comprises first fin 2, second fin 3 and vertical rib part 4, the shape of the metal fin profile is complex, the wall thickness difference is large, the size precision range is narrow, and the user requires high uniformity of the organizational performance at different positions of the profile; in actual production, the extrusion metal flow of different parts of the profile is different, which leads to difficulty in controlling the high-precision size deviation of each part, and increases the difference of organizational performance of each part.
[0005] Therefore, how to solve the problem that the existing mould has large difference in extrusion metal flow of different parts when extruding metal fin profile, and the difference in organizational performance of each part is increased is a technical problem that needs to be solved by the technical personnel in the field. CONTENT OF THE UTILITY MODEL
[0006] Therefore, the utility model aims at providing an extrusion die, by increasing pre-deformation cavity in the mould, the metal flow rate of the bar in the mould is regulated, so as to reduce the difference in extrusion metal flow rate of different parts of metal fin profile and reduce the difference in organizational performance of each part.
[0007] In order to achieve the above-mentioned purpose, the utility model provides the following technical scheme:
[0008] An extrusion die for processing a metal fin profile including a body part and a fin part, the extrusion die including a pre-deformation cavity and a shaping cavity arranged in the die body and communicated, a projection area of the pre-deformation cavity in a die axial direction is greater than a projection area of the shaping cavity in the die axial direction, and the projection of the pre-deformation cavity in the die axial direction completely covers the projection of the shaping cavity in the die axial direction.
[0009] The projection of the shaping cavity in the die axial direction is identical to a cross section of the metal fin profile along its axial direction.
[0010] Preferably, a ratio of the projection area of the pre-deformation cavity in the die axial direction to the projection area of the shaping cavity in the die axial direction is an extrusion ratio, the extrusion ratio of the corresponding position of the body part is less than the extrusion ratio of the corresponding position of the fin part.
[0011] Preferably, a distance between a center line of the pre-deformation cavity of the corresponding position of the body part and the die axial line is less than a distance between a center line of the pre-deformation cavity of the corresponding position of the fin part and the die axial line.
[0012] Preferably, a length of the pre-deformation cavity of the corresponding position of the body part along the die axial direction is less than or equal to a length of the pre-deformation cavity of the corresponding position of the fin part along the die axial direction.
[0013] Preferably, a transition structure is arranged at a connecting position of the pre-deformation cavity and the shaping cavity.
[0014] Preferably, a die pad fixedly arranged at a discharging end of the shaping cavity is further included, a blanking passage and a body passage are arranged in the die pad;
[0015] The blanking passage is communicated with the shaping cavity and used for the metal fin profile to pass through.
[0016] A plurality of groups of partial passages are arranged in communication between the body passage and the blanking passage.
[0017] Preferably, a cross section of the body passage in a direction perpendicular to the die pad axial direction is a ring structure, and the ring structure surrounds the blanking passage.
[0018] Preferably, a number of the partial passages between the body passage and the blanking passage of the corresponding position of the fin part is not less than a number of the partial passages between the body passage and the blanking passage of the corresponding position of the body part.
[0019] Preferably, both ends of the body passage are closed, and a passage entrance communicating with the body passage is arranged in the die pad.
[0020] Compared with the prior art, the extrusion die has at least the following beneficial effects:
[0021] By adding the pre-deformation cavity in the die, the bar is extruded in the pre-deformation cavity, and then the metal flow rate in the pre-deformation cavity is regulated, when the bar enters into the shaping cavity, the metal flow rate difference of different parts is small, which helps to improve the uniformity of the structure performance of different parts of the extruded metal fin profile, and helps to improve the size precision control of the extruded metal profile. BRIEF DESCRIPTION OF DRAWINGS
[0022] In order to more clearly illustrate the technical scheme in the embodiments of the present utility model or the prior art, the following will briefly introduce the drawings needed to be used in the embodiment or the prior art description, obviously, the drawings in the following description are only the embodiments of the present utility model, and for those skilled in the art, other drawings can also be obtained according to the provided drawings without creative labor.
[0023] Figure 1 It is the cross section view of the metal fin profile to be processed;
[0024] Figure 2 It is the structure schematic view of the extrusion die provided by the present utility model;
[0025] Figure 3 It is the projection schematic view of the pre-deformation cavity and the shaping cavity in the die axial direction provided by the present utility model;
[0026] Figure 4 It is the structure schematic view of the die cushion provided by the present utility model.
[0027] In the drawings:
[0028] 1, main body part;2, first fin;3, second fin;4, vertical rib part;5, pre-deformation cavity;6, shaping cavity;7, die main body;8, die cushion;9, passage entrance;10, main body passage;11, local passage. DETAILED DESCRIPTION
[0029] The technical scheme in the embodiments of the present utility model will be clearly and completely described below by combining the drawings in the embodiments of the present utility model, obviously, the described embodiments are only a part of the embodiments of the present utility model, but not all the embodiments. Based on the embodiments in the present utility model, all the other embodiments obtained by those skilled in the art without creative labor belong to the protection scope of the present utility model.
[0030] The core of the utility model discloses an extrusion die, by increasing predeformation cavity in the die, the metal flow rate of the bar in the die is regulated and controlled, and then the metal flow rate difference of different parts of the metal fin profile is reduced, and the performance difference of each part is reduced.
[0031] Another core of the utility model discloses a die design scheme including the extrusion die, which can design the implementable extrusion die to ensure that the size precision of the extruded metal fin profile is controllable, and the performance of each part is uniform.
[0032] Please refer to Figure 2 and Figure 3 An extrusion die for processing a metal fin profile including a main body part 1 and a fin part, the extrusion die includes a predeformation cavity 5 and a shaping cavity 6 arranged in the die body 7 and communicated, the projection area of the predeformation cavity 5 on the die axial direction is greater than the projection area of the shaping cavity 6 on the die axial direction, and the projection of the predeformation cavity 5 on the die axial direction completely covers the projection of the shaping cavity 6 on the die axial direction.
[0033] The projection of the shaping cavity 6 on the die axial direction is the same as the cross section of the metal fin profile along the axial direction.
[0034] As shown in Figure 2 and Figure 3 , the predeformation cavity 5 is arranged at the upstream end of the shaping cavity 6 and communicated, the projection area of the predeformation cavity 5 on the die axial direction is greater than the projection area of the shaping cavity 6 on the die axial direction, and the projection area of the predeformation cavity 5 on the die axial direction completely covers the projection area of the shaping cavity 6 on the die axial direction, and the projection edge of the predeformation cavity 5 on the die axial direction and the projection edge of the shaping cavity 6 on the die axial direction are provided with a reserved distance to adapt to the flow of metal.
[0035] As shown in Figure 1 , the metal fin profile is a symmetrical structure, and the middle is the main body part 1, and the two sides are the fin part, the wall thickness of the main body part 1 is greater than that of the fin part, so when extrusion forming, the metal flow rate corresponding to the main body part 1 in the die is greater than that corresponding to the fin part, causing the extrusion metal flow rate of different positions of the metal fin profile to be different, and then the size precision of the profile is difficult to control, and the performance of each part is not uniform.
[0036] By increasing the predeformation cavity 5, the projection on the die axial direction is similar to the outer contour shape of the profile, so that the bar is predeformed once when passing through the predeformation cavity 5, and the bar fills the predeformation cavity 5 in the process, the metal flow rate of the bar is regulated and controlled, the metal flow rate difference in the shaping cavity 6 corresponding to the main body part 1 and the fin part is reduced, and then the size precision control of the extruded profile is facilitated, and the uniformity of the performance of each part of the extruded profile is improved.
[0037] In some embodiments, the ratio of the projected area of the pre-deformed cavity 5 in the mold axial direction to the projected area of the shaping cavity 6 in the mold axial direction is the extrusion ratio, and the extrusion ratio of the corresponding position of the main body 1 is less than the extrusion ratio of the corresponding position of the fin portion.
[0038] like Figure 1 As shown, the wall thickness of the main body 1 of the metal fin profile is greater than the wall thickness of the first fin 2, the second fin 3 and the vertical rib 4 in the fin section. Therefore, the extrusion ratio at the corresponding position of the main body 1 is set to be less than the extrusion ratio at the corresponding position of the fin section. This can reduce the metal flow velocity at the corresponding position of the main body 1 in the pre-deformation cavity 5, while increasing the metal flow velocity at the corresponding position of the fin section. This reduces the difference in metal flow velocity between the corresponding positions of the main body 1 and the fin section in the pre-deformation cavity 5, ultimately improving the dimensional accuracy control and the uniformity of the microstructure of the extruded profile.
[0039] In some embodiments, the distance between the center line of the pre-deformed cavity 5 at the corresponding position of the main body 1 and the mold axis is less than the distance between the center line of the pre-deformed cavity 5 at the corresponding position of the fin portion and the mold axis.
[0040] like Figure 3 As shown in the figure, the intersection of the dashed lines is the axis of the mold. Because the wall thickness of the main body 1 is greater than that of the fin part, logically, the metal flow velocity at the corresponding position of the main body 1 in the mold is greater than that at the corresponding position of the fin part. Therefore, the distance between the center line of the corresponding position of the main body 1 in the pre-deformed cavity 5 and the mold axis is set to be less than the distance between the center line of the corresponding position of the fin part and the mold axis. This can shorten the flow distance of the metal in the mold along the perpendicular axis of the mold, reduce the flow resistance of the metal, thereby improving the extrusion efficiency of the profile and reducing the heat generated during the extrusion process.
[0041] Meanwhile, the distance between the center line of the main body 1 and the fin part corresponding to the mold axis in the shaping cavity 6 is consistent with the distance between the center line of the shaping cavity 6 corresponding to the main body 1 and the mold axis. That is, the distance between the center line of the shaping cavity 6 corresponding to the main body 1 and the mold axis is less than the distance between the center line of the shaping cavity 6 corresponding to the fin part and the mold axis, further reducing the flow distance of the metal in the mold along the perpendicular axis of the mold.
[0042] In some embodiments, the length of the pre-deformed cavity 5 at the corresponding position of the main body 1 along the mold axial direction is less than or equal to the length of the pre-deformed cavity 5 at the corresponding position of the fin portion along the mold axial direction.
[0043] When designing the pre-deformed cavity 5, it is preferable that the overall axial length of the pre-deformed cavity 5 is consistent, which can reduce the design and processing difficulty.
[0044] But in some embodiments, because the extrusion ratio of the corresponding positions of the main body part 1 and the fin part in the pre-deformation cavity 5 and the sizing cavity 6 is different, and when the bar material is fed into the pre-deformation cavity 5, the metal needs to flow to completely fill the cross section of the pre-deformation cavity 5, and the metal flow rate of the corresponding position of the fin part is slower, therefore, the axial length of the mold at the corresponding position of the fin part in the pre-deformation cavity 5 is designed to be greater than the axial length of the main body part 1, so that the corresponding positions of the main body part 1 and the fin part in the pre-deformation cavity 5 are completely filled with metal of the bar material.
[0045] In some embodiments, a transition structure is arranged at the connection position of the pre-deformation cavity 5 and the sizing cavity 6.
[0046] A fillet is arranged at the connection position of the pre-deformation cavity 5 and the sizing cavity 6, and the radius of the fillet is preferably 3-5 mm, thereby reducing the resistance of the metal flowing between the pre-deformation cavity 5 and the sizing cavity 6, and thereby improving the efficiency of the profile extrusion and reducing the heat generation of the profile extrusion.
[0047] In some embodiments, a die pad 8 fixedly arranged at the discharge end of the sizing cavity 6 is further included, and a discharging channel and a main body channel 10 are arranged in the die pad 8.
[0048] The discharging channel is in communication with the sizing cavity 6 and is used for the metal fin profile to pass through.
[0049] A plurality of groups of local channels 11 are arranged in communication between the main body channel 10 and the discharging channel.
[0050] In the extrusion die, the bar material is extruded into a metal profile, and a large amount of heat is generated by the internal metal flow, making the chemical properties active and easy to react with oxygen in the air, thereby causing the final surface quality and dimensional accuracy of the profile to decrease, so a die pad 8 as shown in Figure 4 is added at the end of the extrusion die, the discharging channel in the die pad 8 can wrap the just-extruded metal profile, and continuously supplement low-temperature nitrogen or inert gas into the discharging channel through the main body channel 10 to rapidly cool the metal profile, and nitrogen or other inert gas is used for protection to avoid surface quality degradation caused by high-temperature oxidation of the profile surface.
[0051] Preferably, liquid nitrogen or other low-temperature inert gas is introduced into the main body channel 10,
[0052] In some embodiments, the cross section of the main body channel 10 perpendicular to the axial direction of the die pad 8 is a ring structure, and the ring structure surrounds the discharging channel.
[0053] As shown in Figure 4As shown, the cross section of the main channel 10 perpendicular to the axial direction of the die pad 8 is a ring structure, which surrounds the feeding channel, i.e. there is only one thin wall between the main channel 10 and the feeding channel. When low-temperature gas or liquid is introduced into the main channel 10, it directly exchanges heat with the feeding channel through the thin wall, increases the heat exchange area, improves the heat exchange efficiency, and at the same time makes the temperature in the feeding channel uniform, so as to promote the rapid cooling of the extruded profile.
[0054] At the same time, the ring structure of the main channel 10 facilitates the dispersion of the local channels 11 at different positions of the feeding channel, so that the low-temperature gas or liquid quickly contacts the surface of the extruded profile, avoiding surface oxidation.
[0055] In some embodiments, the number of local channels 11 between the main channel 10 and the feeding channel at the corresponding position of the fin part is not less than the number of local channels 11 between the main channel 10 and the feeding channel at the corresponding position of the main part 1.
[0056] As shown, Figure 4 The surface area of the fin part of the metal fin profile is larger than that of the main part 1, so more local channels 11 are arranged at the corresponding position of the fin part, so that the gas in the main channel 10 can quickly fill the corresponding position of the fin part, and the gas in the feeding channel is uniformly distributed, avoiding oxidation of the fin part due to low gas concentration.
[0057] In some embodiments, the two ends of the main channel 10 are closed, and the die pad 8 is provided with a channel inlet 9 communicating with the main channel 10.
[0058] The two ends of the main channel 10 are closed to form a closed space, and only the channel inlet 9 is used for the injection of liquid nitrogen, which helps to improve the gas pressure in the main channel 10, and in turn helps to improve the gas flow rate in the local channel 11, so that the liquid nitrogen can be quickly vaporized and fill the feeding channel, thereby ensuring the nitrogen concentration in the feeding channel, improving the cooling efficiency of the extruded profile, and avoiding oxidation of the extruded profile.
[0059] In some embodiments, the pre-deformation cavity 5 is set to 10-15 mm along the axial length of the die, the vertical height of the main part 1 at the corresponding position in the pre-deformation cavity 5 is set to 15-20 mm, and the vertical height of the fin part at the corresponding position is set to 25-30 mm.
[0060] The distance between the upper surface of the main part 1 at the corresponding position in the shaping cavity 6 and the extrusion die axis is 8-15 mm, the part cavity width of the main channel 10 in the die pad 8 is 4-8 mm, the wall thickness between the main channel 10 and the feeding channel is 4-8 mm, and the inner diameter of the local channel 11 is 3-6 mm.
[0061] The design process includes:
[0062] The axial section M1 of the metal fin profile is obtained by measurement. Based on the section M1, the projection M2 of the shaped cavity 6 with the same shape and area is formulated. Based on the ductility of the bar metal and the extrusion speed, the extrusion ratio λ is determined. The projection M3 is drawn from the root projection M2. The optimal shape of the projection M3 is obtained through finite element simulation software.
[0063] Finally, the length H of the pre-deformed cavity 5 in the mold axis is calculated according to the formula;
[0064] The formula for calculating length H is:
[0065]
[0066] Where D is the outer diameter of the metal fin profile (mm).
[0067] K is a correction factor (0.08-0.12, with the upper limit for complex cross-sections).
[0068] In some embodiments, the extrusion ratio λ1 at the corresponding position of the main body 1 in the pre-deformed cavity 5 and the shaping cavity 6 is less than the extrusion ratio λ2 at the corresponding position of the fin. Therefore, the lengths H1 and H2 of the pre-deformed cavity 5 at the corresponding positions of the main body 1 and the fin in the mold axis are calculated respectively.
[0069] Specifically:
[0070] The length H1 of the pre-deformed cavity 5 at the corresponding position of the main body 1 in the mold axial direction is...
[0071]
[0072] The length H2 of the pre-deformed cavity 5 at the corresponding position of the fin section in the mold axis.
[0073]
[0074] Based on the maximum wall thickness of the metal fin profile With minimum wall thickness The ratio is used to correct the length H.
[0075] For some metal finned profiles, if the ratio of the maximum wall thickness to the minimum wall thickness is greater than or equal to 2, the length of the pre-deformed cavity 5 needs to be revised, referring to the following formula:
[0076]
[0077] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.
[0078] The extrusion die provided by the utility model is described in detail. The principle and implementation mode of the utility model are described by applying specific examples, and the above description of the examples is only used for helping to understand the method and core idea of the utility model. It should be pointed out that, for ordinary skilled persons in the technical field, some improvements and modifications can be made to the utility model without departing from the principle of the utility model, and these improvements and modifications also fall within the protection scope of the utility model claim.
Claims
1. An extrusion die for processing metal fin profiles comprising a main body (1) and a fin portion, characterized in that, It includes a pre-deformed cavity (5) and a fixed cavity (6) disposed within and connected to the mold body (7). The projected area of the pre-deformed cavity (5) in the mold axis is greater than the projected area of the fixed cavity (6) in the mold axis, and the projection of the pre-deformed cavity (5) in the mold axis completely covers the projection of the fixed cavity (6) in the mold axis. The projection of the shaping cavity (6) on the mold axis is the same as the cross section of the metal fin profile along its own axis.
2. The extrusion die according to claim 1, characterized in that, The ratio of the projected area of the pre-deformed cavity (5) on the mold axis to the projected area of the shaped cavity (6) on the mold axis is the extrusion ratio. The extrusion ratio of the corresponding position of the main body (1) is less than the extrusion ratio of the corresponding position of the fin part.
3. The extrusion die according to claim 1, characterized in that, The distance between the center line of the pre-deformed cavity (5) at the corresponding position of the main body (1) and the mold axis is less than the distance between the center line of the pre-deformed cavity (5) at the corresponding position of the fin and the mold axis.
4. The extrusion die according to claim 1, characterized in that, The length of the pre-deformed cavity (5) at the corresponding position of the main body (1) along the mold axis is less than or equal to the length of the pre-deformed cavity (5) at the corresponding position of the fin part along the mold axis.
5. The extrusion die according to claim 1, characterized in that, A transition structure is provided at the connection position between the pre-deformed cavity (5) and the fixed cavity (6).
6. The extrusion die according to claim 1, characterized in that, It also includes a mold pad (8) fixedly disposed at the discharge end of the molding cavity (6), and the mold pad (8) is provided with a material discharge channel and a main body channel (10). The feeding channel is connected to the shaping cavity (6) for the metal fin profile to pass through; Several sets of local channels (11) are provided to connect the main channel (10) and the feeding channel.
7. The extrusion die according to claim 6, characterized in that, The main channel (10) has an annular structure in the cross section perpendicular to the axial direction of the mold pad (8), and the annular structure surrounds the feeding channel.
8. The extrusion die according to claim 7, characterized in that, The number of local channels (11) between the main channel (10) and the feeding channel at the corresponding position of the fin portion is not less than the number of local channels (11) between the main channel (10) and the feeding channel at the corresponding position of the main body (1).
9. The extrusion die according to claim 7, characterized in that, The two ends of the main channel (10) are closed, and the mold pad (8) is provided with a channel entrance (9) that connects to the main channel (10).