Aluminum alloy bar diameter reducing casting device and method

Abstract

The invention proposes a diameter-reducing casting device and method for aluminum alloy bars, and relates to the technical field of casting. The device comprises a tundish, a crystallizer, a structure control device and a traction device; the structure control device consists of a first sleeve and a cooling module, a diameter-reducing cavity is arranged in the first sleeve, the inner diameter of the diameter-reducing cavity gradually decreases from the first end to the second end, and is used for cooling and solidifying the solid-liquid aluminum alloy bar; the traction device comprises a traction head forming die and a power device, the traction head forming die is located at the second end of the diameter-reducing cavity, and the power device drives the traction head forming die to move horizontally to pull out the aluminum alloy bar; through plastic deformation and cooling and solidification in the diameter-reducing cavity, internal defects of the aluminum alloy such as shrinkage are eliminated, the grains are refined, and the structure is more dense and uniform; the close connection between the traction head and the bar improves the traction force and enhances the stability of the continuous casting process; the power device accurately adjusts the traction rate to obtain an aluminum alloy bar with a dense structure and a small and uniform grain size.

Description

Technical Field

[0001] The invention relates to the technical field of casting, and in particular to a diameter-reducing casting device and method for an aluminum alloy bar. Background Art

[0002] Aluminum alloys are widely used in aerospace, transportation, electronics and other fields due to their excellent mechanical properties, lightweight characteristics and good processing performance. In the production process of aluminum alloys, continuous casting technology, as an important casting method, has been widely used due to its high production efficiency and casting quality. Among them, horizontal continuous casting (HCC) is an advanced casting technology. It pours liquid aluminum alloy horizontally into the cooling zone and gradually solidifies it to form aluminum alloy ingots. It has a relatively uniform cooling rate and solidification process, which can effectively improve the quality of castings and reduce the occurrence of defects.

[0003] The main advantages of horizontal continuous casting include higher production efficiency, more uniform grain distribution and better ingot quality. However, there are still some technical difficulties in the application of horizontal continuous casting technology to produce aluminum alloy bars. First, since the cooling rate of the surface metal is significantly faster than that of the core metal during the casting process, it is easy to cause shrinkage defects inside the cast aluminum alloy bar, especially in the area close to the core. This defect not only affects the mechanical properties of the aluminum alloy bar, but may also affect its subsequent processing performance. Secondly, although the horizontal continuous casting technology can obtain relatively small and uniform grains, in some cases, the size and morphology of the ingot will still affect the growth of the grains, especially when producing larger ingots, it is often easy to have problems with uneven grain size or abnormal grain growth in local areas, thereby affecting the overall quality of the ingot and subsequent processing. Summary of the invention

[0004] In view of this, the present invention proposes an aluminum alloy bar diameter reducing casting device and method to solve the problems of shrinkage, uneven grain size and abnormal grain growth inside the aluminum alloy bar during continuous casting production.

[0005] The technical solution of the present invention is achieved in this way:

[0006] In a first aspect, the present invention provides an aluminum alloy bar diameter reducing casting device, comprising a tundish and a crystallizer, wherein the feed port of the crystallizer is connected to the discharge port of the tundish, and is characterized in that: it also includes a tissue control device and a traction device;

[0007] The tissue control device comprises a first sleeve and a cooling module, wherein the first sleeve has a through-going reducing cavity, the reducing cavity has a first end and a second end, the inner diameter of the reducing cavity gradually decreases from the first end to the second end, the first end of the reducing cavity is connected to the discharge port of the crystallizer in the horizontal direction, and the cooling module is arranged on the first sleeve, and is used to cool and solidify the solid-liquid aluminum alloy bar inside the reducing cavity;

[0008] The traction device includes a traction head forming die and a power device. At least a portion of the traction head forming die is located at the second end of the reducing cavity, and is used to form a traction head at the end of the aluminum alloy rod. The power device is used to drive the traction head forming die to move horizontally in the direction of the first sleeve away from the crystallizer, so as to pull the aluminum alloy rod out of the tissue control device through the traction head in the traction head forming die.

[0009] On the basis of the above technical solution, preferably, the traction head forming mold includes a concave mold and a convex mold;

[0010] The central axis of the die is provided with a through-going tapered hole, the inner diameter of which gradually increases from an end facing the first sleeve to an end away from the first sleeve, and the inner wall of the tapered hole is provided with a plurality of grooves at equal intervals around the central axis;

[0011] The punch is inserted in the tapered hole. The punch consists of two symmetrically matched mold halves. The outer surface of the mold halves has a tapered surface that matches the tapered hole. The tapered surface is provided with a protrusion that matches the groove. The opposite sides of the two mold halves are symmetrically provided with a mold cavity for a forming traction head.

[0012] On the basis of the above technical solution, preferably, the power device includes a traction rod and a traction wheel;

[0013] The die end surface where the tapered hole has a large diameter has a first electromagnet with an annular structure;

[0014] A second electromagnet with a semicircular structure is provided on the end surface where the major diameter of the mold piece is located;

[0015] The traction wheels are symmetrically arranged in two and are located on a side of the tissue control device away from the crystallizer;

[0016] One end of the traction rod passes through two traction wheels and can move horizontally under the drive of the traction wheels. The other end of the traction rod is provided with an electromagnetic traction disk, which interacts with the first electromagnet and the second electromagnet to achieve the connection or separation of the traction rod and the traction head forming mold.

[0017] On the basis of the above technical solution, preferably, it further comprises a separation device, wherein the separation device comprises teeth and a gear set;

[0018] The teeth are arranged on the outer peripheral surface of one end of the die away from the first sleeve, and the outer diameter of the teeth is smaller than the outer diameter of the die;

[0019] The gear set is located between the tissue control device and the traction wheel, and includes at least three driving gears evenly arranged around the central axis of the die. The driving gear can adjust its position relative to the die. The driving gear is used to engage with the teeth to drive the traction head forming mold to rotate, thereby separating the traction head from the rod body.

[0020] On the basis of the above technical solution, preferably, the tissue control device also includes a second sleeve and a temperature control module. The second sleeve is horizontally fixed at one end of the first sleeve away from the crystallizer. The second sleeve has a cylindrical cavity that is arranged through, and the cylindrical cavity is connected to the reducing cavity. The temperature control module is arranged on the second sleeve for cooling the surface of the aluminum alloy rod entering the second sleeve.

[0021] On the basis of the above technical solution, preferably, a gate is provided between the discharge port of the tundish and the feed port of the crystallizer.

[0022] On the basis of the above technical solution, preferably, the crystallizer includes a cylinder and a graphite pipe fixedly arranged on the inner wall of the cylinder, the outer wall of the cylinder is provided with a lubricant channel connected to the inner wall of the graphite pipe, and a cooling chamber is also arranged between the cylinder and the graphite pipe.

[0023] In a second aspect, the present invention provides an aluminum alloy bar casting method, which utilizes the aluminum alloy bar diameter reducing casting device described in the first aspect, and is characterized in that it comprises the following steps:

[0024] S1, installing the traction head forming die inside the second end of the diameter reducing cavity and assembling it with the power device;

[0025] S2. The liquid aluminum alloy solution in the tundish flows into the crystallizer, and a dual-state aluminum alloy bar with a solid surface and a liquid core is formed in the crystallizer. The liquid aluminum alloy in the core drives the solidified aluminum alloy on the surface to slide into the first sleeve under the action of gravity;

[0026] S3, cooling the first sleeve by means of a cooling module, the liquid aluminum alloy continues to gradually cool and solidify from the surface layer to the core under the cooling effect, and at the same time, the liquid aluminum alloy in the core flows into the traction head forming mold to form the traction head;

[0027] S4. When the pulling head is completely formed, the power device drives the pulling head in the pulling head forming die to pull the aluminum alloy rod out of the organization control device.

[0028] On the basis of the above technical solution, preferably, step S4 further includes the following operation steps:

[0029] S41, making the polarity of the electromagnetic traction plate opposite to that of the first electromagnet and the second electromagnet, and the electromagnetic traction plate realizes the connection between the traction rod and the traction head forming mold by magnetic attraction with the first electromagnet and the second electromagnet;

[0030] S42, the traction wheel drives the traction rod to drive the traction head forming die to translate, and the alloy rod is pulled out from the organization control device at a certain speed;

[0031] S43. When the available rod length meets the requirement, the discharge port of the tundish is closed, and when the aluminum alloy rod is completely pulled out of the tissue control device, the traction wheel stops moving;

[0032] S44, cutting off the non-full cylindrical area formed at the tail end of the rod;

[0033] S45, disconnecting the traction rod and the traction head forming mold by meshing the teeth on the gear set and the concave mold, and driving the traction head forming mold to rotate by the gear set to separate the traction head from the rod body;

[0034] S46, the electromagnetic traction disc on the traction rod is adsorbed by the second electromagnet on the punch, and the punch is pulled out by the traction rod, the connection between the traction rod and the punch is disconnected, and the traction head is separated from the punch;

[0035] S47, reinstalling the punch into the die, and then driving the traction head forming die to move to the inside of the second end of the diameter reducing cavity through the traction rod;

[0036] S48. Open the discharge port of the tundish to cast the next aluminum alloy bar.

[0037] On the basis of the above technical solution, preferably, when the rod passes through the second sleeve, the surface of the rod after diameter reduction is cooled and regulated by the temperature control module, and a temperature gradient is formed along the diameter direction or length direction of the rod. The moving rate of the traction head forming die is coordinated to cause different regions of the rod to undergo different degrees of recrystallization and grain growth, and ultimately produce an aluminum alloy rod with a gradient grain size distribution.

[0038] Compared with the prior art, the present invention has the following beneficial effects:

[0039] (1) The aluminum alloy bar diameter reduction casting device disclosed in the present invention effectively eliminates internal defects of the aluminum alloy such as shrinkage through plastic deformation and cooling and solidification processes in the diameter reduction cavity, and at the same time, the grains are refined, and the structure of the aluminum alloy bar is denser and more uniform; through the close connection between the traction head and the aluminum alloy bar, the traction force is improved and the stability of the continuous casting process is enhanced; the power device can accurately adjust the traction rate, thereby realizing the control of the diameter reduction strain rate, and can accurately control the grain size of the aluminum alloy bar to obtain an aluminum alloy bar with a denser structure.

[0040] (2) By forming a traction head forming mold with a punch and a die and optimizing the structures of the punch and the die, on the one hand, the punch can be stably and reliably assembled and connected with the die to realize reliable forming of the traction head. At the same time, with the help of the electromagnetic connection and separation process between the traction rod and the traction head forming mold, as well as the coordinated use of the separation device and the die, the traction head can be effectively separated from the rod, and the traction head can be separated from the traction head forming mold, which greatly improves the beats of each casting process and improves the casting efficiency of aluminum alloy rods.

[0041] (3) By setting up a second sleeve and a temperature control module, when the rod is pulled out of the diameter reducing cavity, it will pass through the cylindrical cavity of the second sleeve. The entire rod will be shaped in the cylindrical cavity. The cylindrical cavity can provide a smooth surface foundation for the outer surface of the rod. At the same time, the temperature of the rod surface can be regulated by the temperature control module, and the degree of recrystallization on the rod surface can be controlled to inhibit the abnormal growth of grains on the surface of the rod, thereby reducing the temperature difference between the surface and the core of the rod after diameter reduction, thereby reducing the difference in grain size. Combined with a certain pulling rate, it is possible to obtain an aluminum alloy rod with a denser structure and a finer and more uniform grain size.

[0042] (4) By precisely controlling the pulling and separation process of the aluminum alloy bars, the casting quality and production efficiency of the aluminum alloy bars are optimized. Specifically, the electromagnetic traction system and mechanical drive are combined to ensure the precise connection and separation between the traction head and the aluminum alloy bars, avoiding uneven stress or material damage during the stretching process; at the same time, by controlling the discharge port of the tundish and cutting off the tail end of the non-integral cylinder, the generation of defective areas is effectively avoided, and the quality of the bars is improved. This method can efficiently and stably complete the continuous casting of aluminum alloy bars and ensure that the quality of each bar meets the requirements. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0044] Figure 1 It is a schematic plan view of the structure of the aluminum alloy bar diameter reducing casting device disclosed in the present invention;

[0045] Figure 2 It is a schematic diagram of the planar structure of the concave mold disclosed in the present invention;

[0046] Figure 3 It is a schematic diagram of the planar structure of the male mold disclosed in the present invention;

[0047] Figure 4It is a schematic diagram of the planar structure of the crystallizer disclosed in the present invention;

[0048] Figure 5 It is a schematic diagram of the structural state of the aluminum alloy bar diameter reducing casting device disclosed in the present invention when the gate is closed;

[0049] Figure 6 It is a schematic diagram of the state of the aluminum alloy solution disclosed in the present invention flowing into the traction head forming die;

[0050] Figure 7 It is a schematic diagram of the state of the traction head disclosed in the present invention after being fully formed;

[0051] Figure 8 It is a schematic diagram of the rod pulling-out state disclosed in the present invention;

[0052] Fig. 9 It is a schematic diagram of the state after the tail of the rod disclosed in the present invention is cut off;

[0053] Fig.10 It is a schematic diagram of the meshing state of the gear set and the teeth after the forming molds of the traction rod and the traction head disclosed in the present invention are separated;

[0054] Fig.11 It is a schematic diagram of the connection state between the traction rod and the traction head forming mold after the traction head disclosed in the present invention is separated from the rod;

[0055] Fig.12 It is a schematic diagram of a state in which the traction head disclosed in the present invention is separated from the male mold;

[0056] Reference numerals:

[0057] 1. Tundish; 11. Gate; 2. Crystallizer; 21. Cylinder; 22. Graphite pipe; 211. Lubricant channel; 212. Cooling chamber; 3. Organization control device; 31. First sleeve; 32. Cooling module; 311. Reducing cavity; 33. Second sleeve; 34. Temperature control module; 331. Cylindrical cavity; 4. Traction device; 41. Traction head forming mold; 411. Concave mold; 412. Punch mold; 4111. Conical Hole; 4112, groove; 4120, mold flap; 4121, conical surface; 4122, protrusion; 4123, mold cavity; 42, power device; 421, traction rod; 422, traction wheel; 423, electromagnetic traction disk; C1, first electromagnet; C2, second electromagnet; 5, separation device; 51, teeth; 52, gear set; 521, driving gear; Q, traction head; P, rod; P1, core; P2, surface layer. DETAILED DESCRIPTION

[0058] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0059] like Figure 1 As shown, combined Figure 2-3 The present invention discloses a diameter-reducing casting device for aluminum alloy bars, comprising a tundish 1 and a crystallizer 2, wherein the feed port of the crystallizer 2 is connected to the discharge port of the tundish 1. The tundish 1 is responsible for containing the liquid aluminum alloy obtained from the smelting furnace, and the crystallizer 2 receives the liquid aluminum alloy from the tundish 1. The liquid aluminum alloy enters the casting process through the crystallizer 2, and begins to solidify in the crystallizer 2 to form a cast billet.

[0060] When the aluminum alloy bar P is continuously cast through the crystallizer 2, the cooling rate of the surface layer P2 metal is significantly faster than that of the core P1 metal, which easily leads to shrinkage defects inside the cast aluminum alloy bar, especially in the area near the core P1. This defect not only affects the mechanical properties of the aluminum alloy bar, but also may affect its subsequent processing performance. At the same time, when producing large-sized billets, it is often easy to have problems such as uneven grain size or abnormal grain growth in local areas, thereby affecting the overall quality of the billet and subsequent processing.

[0061] In order to solve the above problems, the aluminum alloy bar diameter reducing casting device of this embodiment also introduces a tissue control device 3 and a traction device 4 as solutions.

[0062] Specifically, the tissue control device 3 includes a first sleeve 31 and a cooling module 32. The first sleeve 31 has a reducing cavity 311 that is arranged through, and the reducing cavity 311 has a first end and a second end. The inner diameter of the reducing cavity 311 gradually decreases from the first end to the second end. The first end of the reducing cavity 311 is connected to the discharge port of the crystallizer 2 in the horizontal direction. The cooling module 32 is arranged on the first sleeve 31, and is used to cool and solidify the solid-liquid aluminum alloy rod inside the reducing cavity 311.

[0063] In this embodiment, the cooling method of the cooling module 32 is liquid cooling or air flow cooling.

[0064] The aluminum alloy liquid passing through the crystallizer 2 begins to solidify to form a preliminary ingot, and enters the reducing cavity 311 for further plastic deformation. The ingot undergoes plastic deformation in the reducing cavity 311. This process not only gradually reduces the size of the aluminum alloy ingot, but also has an important impact on the microstructure of the aluminum alloy. The reducing deformation can promote the refinement of the aluminum alloy grains, improve the uniformity of the grains, and eliminate internal defects such as shrinkage through stretching.

[0065] In the process of cooling and solidifying the aluminum alloy in the reducing cavity 311, the liquid metal in the aluminum alloy core P1 continues to solidify while being affected by plastic deformation. The coupling effect of cooling and deformation helps to eliminate the shrinkage defects generated after solidification, and at the same time makes the structure of the aluminum alloy more dense and uniform.

[0066] During the solidification process of the aluminum alloy, shrinkage defects are usually generated inside the ingot due to uneven cooling rate. The plastic deformation in the diameter reduction cavity 311 helps to change the flow state of the aluminum alloy, promotes the uniform solidification of the liquid aluminum alloy through a certain stress effect, reduces the generation of defects, and thus obtains a rod with a denser structure.

[0067] The traction device 4 of this embodiment includes a traction head forming die 41 and a power device 42. At least a part of the traction head forming die 41 is located at the second end of the diameter reducing cavity 311, and is used to form a traction head Q at the end of the aluminum alloy bar. In this embodiment, the end of the traction head forming die 41 extends into the diameter reducing cavity 311, and the outer peripheral surface of the traction head forming die 41 contacts the inner wall of the second end of the diameter reducing cavity 311. Since the aluminum alloy solution flows naturally in the diameter reducing cavity 311 by gravity, and the surface layer P2 of the aluminum alloy bar can be quickly solidified into a solid state in the diameter reducing cavity 311, the liquid aluminum alloy will not overflow from the traction head forming die 41 and the outlet of the diameter reducing cavity 311. Only the core P1 is in a liquid state, and the liquid aluminum alloy of the core P1 flows into the traction head forming die 41 to form the traction head Q.

[0068] The traction head Q is formed during the initial solidification process of the liquid aluminum alloy. The traction head Q is tightly connected to the main body of the aluminum alloy bar P, and can bear a greater traction force. At the same time, it makes the traction process more stable, thereby ensuring the continuity of the aluminum alloy bar during the continuous casting process.

[0069] The power device 42 is used to drive the pulling head forming die 41 to move horizontally in a direction away from the crystallizer 2 toward the first sleeve 31 , so as to pull the aluminum alloy rod out of the tissue control device 3 through the pulling head in the pulling head forming die 41 .

[0070] The power device 42 changes the diameter reduction rate in the diameter reduction cavity 311 by adjusting the moving rate of the traction head forming die 41. This regulation can provide different energy storage states for the aluminum alloy bar and adjust the degree of refinement and uniformity of its grains according to demand. By adjusting the diameter reduction strain rate, the grain size of the aluminum alloy bar can be accurately controlled so that it maintains a relatively uniform structure throughout the casting process. An appropriate diameter reduction strain rate can effectively avoid excessive or uneven grain size, thereby improving the mechanical properties and processability of the aluminum alloy bar.

[0071] The aluminum alloy bar diameter reduction casting device disclosed in the present invention effectively eliminates internal defects of the aluminum alloy such as shrinkage through plastic deformation and cooling and solidification processes in the diameter reduction cavity 311, and at the same time, the grains are refined, and the structure of the aluminum alloy bar is more compact and uniform. The traction force is improved and the stability of the continuous casting process is enhanced by the close connection between the traction head Q and the aluminum alloy bar. The power device 42 can accurately adjust the traction rate, thereby realizing the control of the diameter reduction strain rate, and can accurately control the grain size of the aluminum alloy bar, so as to obtain an aluminum alloy bar with a denser structure and a more uniform grain size.

[0072] In order to realize that the traction head forming mold 41 can effectively form the traction head Q, this embodiment shows a preferred structural mode of the traction head forming mold 41. Figure 2 and 3 As shown, the traction head forming mold 41 of this embodiment includes a concave mold 411 and a convex mold 412 .

[0073] The concave mold 411 has a through-going tapered hole 4111 at the center axis thereof, the inner diameter of the tapered hole 4111 gradually increases from the end facing the first sleeve 31 to the end away from the first sleeve 31, and a plurality of grooves 4112 are evenly spaced around the center axis of the inner wall of the tapered hole 4111. The convex mold 412 is inserted into the tapered hole 4111, and the convex mold 412 is composed of two symmetrically matched mold halves 4120, the outer surface of the mold halves 4120 has a tapered surface 4121 matched with the tapered hole 4111, and a protrusion 4122 matched with the groove 4112 is provided on the tapered surface 4121, and a mold cavity 4123 for forming the traction head Q is symmetrically opened on the opposite side of the two mold halves 4120.

[0074] By adopting the above technical scheme, through the setting of the tapered hole 4111, the punch 412 is conveniently inserted into the tapered hole 4111, and the tapered surfaces 4121 on the outer surfaces of the two mold halves 4120 are wedged and connected with the tapered hole 4111, and the protrusions 4122 on the mold halves 4120 cooperate with the grooves 4112 on the die 411, so that after the two mold halves 4120 are fitted into the inside of the die 411, the two mold halves 4120 cannot rotate relative to the central axis of the die 411, so as to avoid the punch 412 rotating relative to the die 411 during the translation of the traction head forming mold 41 and applying torque to the traction head Q, thereby keeping the traction head Q stably connected to the aluminum alloy rod body in the membrane cavity.

[0075] In the above embodiment, the inner diameter of the mold cavity 4123 between the two mold halves 4120 gradually increases along the pulling direction. Figure 7As shown, assuming that the pulling direction is horizontally to the right, the pulling head Q applies a horizontal force to the left on the inner surface of the male mold 412 and the female mold 411 during the pulling process, so that the outer surface of the male mold 412 and the inner surface of the female mold 411 form a wedge structure to achieve self-locking. As some preferred structures of the mold cavity 4123, the longitudinal section of the mold cavity 4123 is an isosceles triangle structure, and the pulling head Q of the isosceles triangle plate structure formed in this way is balanced and stable during the pulling process.

[0076] It is worth noting that the end of the mold cavity 4123 close to the reducing cavity 311 is a cylindrical cavity 331 structure. In this way, the entire traction head Q is composed of a section of cylinder and a triangular plate structure. Through such a setting of the traction head Q, it is also convenient to separate the traction head Q from the rod body later.

[0077] In order to facilitate the power device 42 to smoothly pull the rod P out of the tissue control device 3 through the traction head forming mold 41, this embodiment shows a preferred structural mode of the power device 42.

[0078] Specifically, the power device 42 includes a traction rod 421 and a traction wheel 422. The traction wheel 422 is used to drive the traction rod 421 to move horizontally, and the traction rod 421 is used to be detachably connected to the traction head forming mold 41, so that it is convenient to disassemble and assemble the punch 412 on the die 411, so that the traction head Q is separated from the rod, and it is also convenient to separate the traction head Q from the punch 412. In addition, it is also convenient for the traction rod 421 to pull the punch 412 and the die 411 synchronously.

[0079] In this embodiment, the end face of the die 411 where the large diameter of the tapered hole 4111 is located has a first electromagnet C1 with an annular structure, and the end face of the mold half 4120 where the large diameter is located is provided with a second electromagnet C2 with a semicircular structure. The second electromagnets C2 on the two mold halves 4120 form an annular electromagnet, and the first electromagnet C1 and the second electromagnet C2 are controlled to be powered on or off by an electric control system, and the polarity of the first electromagnet C1 and the second electromagnet C2 can also be adjusted.

[0080] Two traction wheels 422 are symmetrically arranged and located on the side of the tissue control device 3 away from the crystallizer 2. The two traction wheels 422 are driven to rotate by a rotary motor. One end of the traction rod 421 passes through the two traction wheels 422 and can move horizontally under the drive of the traction wheels 422. The other end of the traction rod 421 is provided with an electromagnetic traction disk 423. The electromagnetic traction disk 423 can be powered on or off by the electric control system, and its polarity can be adjusted. The electromagnetic traction disk 423 interacts with the first electromagnet C1 and the second electromagnet C2 to achieve the connection or separation of the traction rod 421 and the traction head molding mold 41.

[0081] See attached Figure 5-7As shown, in some embodiments, after the punch 412 is installed on the die 411, the traction rod 421 is driven to translate by the traction wheel 422, so that the electromagnetic traction disk 423 at the end of the traction rod 421 contacts the large diameter ends of the punch 412 and the die 411. At this time, the polarity of the electromagnetic traction disk 423 is adjusted to the N pole, and the polarity of the first electromagnet C1 and the second electromagnet C2 is adjusted to the S pole, so that the electromagnetic traction disk 423 can simultaneously magnetically adsorb the first electromagnet C1 and the second electromagnet C2, thereby realizing the synchronous fixed connection of the traction rod 421 to the punch 412 and the die 411. In this way, the traction wheel 422 rotates to drive the traction rod 421 to drive the traction head forming mold 41 to move toward the side away from the crystallizer 2, thereby smoothly pulling the continuously cast rod out of the tissue control device 3.

[0082] When the electromagnetic traction disk 423, the first electromagnet C1 and the second electromagnet C2 are all powered off, the entire power device 42 will be disconnected from the traction head forming mold 41. At this time, other mechanisms can act on the traction head forming mold 41 to separate the traction head Q in the traction head forming mold 41 from the rod body.

[0083] In order to separate the traction head Q from the rod body, the aluminum alloy rod diameter reducing casting device of this embodiment further includes a separation device 5 , which includes teeth 51 and a gear set 52 .

[0084] Among them, the teeth 51 are arranged on the outer peripheral surface of one end of the die 411 away from the first sleeve 31, and the outer diameter of the teeth 51 is smaller than the outer diameter of the die 411. Therefore, during the traction process, the teeth 51 will not contact the inner surface of the second sleeve 33 described below, which can avoid the teeth 51 causing scratches on the inner surface of the second sleeve 33, resulting in burrs on the surface of the rod P after passing through the second sleeve 33.

[0085] The gear set 52 is located between the tissue control device 3 and the traction wheel 422, and includes at least three driving gears 521 evenly arranged around the central axis of the die 411. The driving gear 521 can adjust the distance between itself and the die 411. The driving gear 521 is used to mesh with the teeth 51 to drive the traction head forming mold 41 to rotate, thereby separating the traction head Q from the rod body.

[0086] See attached Figure 8-12 As shown, when the traction wheel 422 drives the traction head forming mold 41 to translate through the traction rod 421, the traction head Q in the traction head forming mold 41 pulls the rod out of the organization control device 3 at a certain rate. When the available rod length meets the requirement, the discharge port of the tundish 1 is closed. When the aluminum alloy rod is completely pulled out of the organization control device 3, the traction wheel stops moving, the non-integral cylindrical area formed at the tail end of the rod is cut off, and the connection between the traction rod and the traction head forming mold 41 is disconnected.

[0087] It is worth noting that the non-full cylindrical area formed at the tail end of the rod is the part that has not been fully solidified and formed. This part is roughly half of the diameter of the rod. These parts have uneven tissues and the quality does not meet the requirements. After this part is cut off, it does not affect the effective length of the rod. At this time, the effective rod is connected through the traction head Q and the traction head forming mold 41, and the gear set 52 and the teeth 51 on the die 411 are engaged, and the connection between the traction rod and the traction head forming mold 41 is disconnected. The position of the rod is fixed by a fixing device to prevent it from rotating. The gear set 52 drives the traction head forming mold 41 to rotate, so as to achieve the separation of the traction head Q and the rod body.

[0088] In the above embodiment, the gear set 52 can move between the tissue control device 3 and the traction wheel 422. This is because the position of the traction head forming mold 41 is not fixed and may change with the change of the effective length of the rod. Therefore, when the position of the effective part of the rod is determined, the gear set 52 can be moved to align with the teeth 51 of the die 411, and at least three driving gears 521 can be synchronously engaged with the teeth 51 on the outer peripheral surface of the die 411. The driving gear 521 rotates, thereby driving the traction head forming mold 41 and the rod body to rotate relative to each other, and then the traction head Q is separated from the rod through a certain torque. At this time, an aluminum alloy rod that meets the requirements can be obtained.

[0089] In this embodiment, by setting at least three driving gears 521, the position of the die 411 can be effectively limited, so that the die 411 can always rotate around its central axis. At least one of the three driving gears 521 can be used as a driving gear, and the rest can be used as driven gears, so that sufficient rotational power can be maintained.

[0090] In addition, after the traction head Q is separated from the rod body, the traction head Q is retained in the punch 412, and the traction rod 421 is used to approach the traction head forming mold 41, so that the electromagnetic traction disk 423 is only adsorbed on the second magnet, and then the traction rod 421 drives the punch 412 to be removed from the die 411. When the electromagnetic traction disk 423 and the second magnet are powered off, the entire punch 412 will fall off, and the two mold halves 4120 will separate. At this time, the traction head Q will be separated from the mold halves 4120. In order to facilitate the traction head Q to be removed from the mold cavity 4123 of the mold halves 4120, a release agent can be applied in the mold cavity 4123 in advance. This will facilitate the demolding of the traction head Q.

[0091] During the entire process of separation of the traction head Q, the gear set 52 is always engaged with the teeth 51 on the die 411 to ensure that the central axis of the die 411 is coaxial with the central axis of the reducing cavity 311, which facilitates the subsequent movement of the traction head molding mold 41 back to the second end of the reducing cavity 311.

[0092] During the specific operation, the punch 412 is installed inside the die 411, and the traction rod is driven to contact the traction head forming mold 41 through the traction wheel 422, and the traction rod 421 is connected to the traction head forming mold 41 through the adsorption of the electromagnetic traction disk 423 and the first electromagnet C1 and the second electromagnet C2. At this time, the gear set 52 and the die 411 are disconnected, and the traction wheel 422 drives the traction rod 421 to move toward the tissue control device 3, so that the traction forming mold moves away from one end of the traction rod 421 into the second end of the reducing cavity 311, and the furnace is opened, so that the next aluminum alloy bar can be cast.

[0093] After the rod is pulled out of the reducing cavity 311, the surface deformation of the aluminum alloy rod after diameter reduction is more severe than that of the core P1, the surface energy storage is higher than that of the core P1, and the surface temperature of the rod is also higher, which may cause abnormal growth of grains, making the entire rod surface and core P1 structure not dense and the grain size uneven.

[0094] In order to solve the above technical problems, the solution adopted in this embodiment is: the tissue control device 3 also includes a second sleeve 33 and a temperature control module 34. The second sleeve 33 is horizontally fixedly arranged at one end of the first sleeve 31 away from the crystallizer 2. The second sleeve 33 has a cylindrical cavity 331 that is arranged through, and the cylindrical cavity 331 is connected to the reducing cavity. The temperature control module 34 is arranged on the second sleeve 33, and is used to control the temperature of the surface of the aluminum alloy rod entering the second sleeve 33.

[0095] According to the arrangement, after the rod is pulled out from the reducing cavity 311, it will pass through the cylindrical cavity 331 of the second sleeve 33, and the entire rod will be shaped in the cylindrical cavity 331. The cylindrical cavity 331 can provide a smooth surface foundation for the outer surface of the rod. At the same time, the temperature of the rod surface can be regulated by the temperature control module 34, and the degree of recrystallization on the rod surface can be controlled to inhibit the abnormal growth of grains on the surface of the rod, thereby reducing the temperature difference between the surface and the core of the rod after reducing the diameter, thereby reducing the difference in grain size. In combination with a certain pulling rate, an aluminum alloy rod with a denser structure and a finer and more uniform grain size can be obtained.

[0096] In this embodiment, the temperature control module 34 may be a temperature control coil group.

[0097] In this embodiment, a gate 11 is provided between the discharge port of the tundish 1 and the feed port of the crystallizer 2. By providing the gate 11, the gate 11 can be opened during the initial casting to allow the aluminum alloy solution in the furnace to flow into the crystallizer 2 and then into the diameter reducing cavity 311 to achieve diameter reducing and solidification of the rod.

[0098] In addition, when the traction head Q in the traction head forming mold 41 pulls the rod out of the tissue control device 3 at a certain rate and the available rod length meets the requirement, the gate 11 is closed. After the gate 11 is closed, all the rods of the crystallizer 2 and the entire tissue control device 3 are pulled out, and there is basically no residual aluminum alloy metal in the crystallizer 2 and the entire tissue control device 3. In this way, it is convenient to separate the traction head Q, cut off the tail end of the rod, and provide casting space for the next rod casting.

[0099] In this embodiment, the gate 11 is driven by a rolling shutter device, which can drive the gate 11 to move up and down, thereby closing or opening the discharge port of the tundish 1.

[0100] In this embodiment, refer to the attached Figure 4 As shown, the crystallizer 2 includes a cylinder 21 and a graphite pipe 22 fixedly arranged on the inner wall of the cylinder 21 , a lubricant channel 211 connected to the inner wall of the graphite pipe 22 is opened on the outer wall of the cylinder 21 , and a cooling chamber 212 is also arranged between the cylinder 21 and the graphite pipe 22 .

[0101] Specifically, during the casting process, a cooling medium can be continuously introduced into the cooling chamber 212 to provide a cooling effect for the solidification of the liquid aluminum alloy. After the liquid aluminum alloy enters the crystallizer 2, the area in contact with the graphite pipe 22 is cooled and solidified first. By injecting lubricant into the lubricant channel 211 to lubricate and enter the inner wall of the graphite pipe 22, the friction between the surface of the solidified aluminum alloy and the inner surface of the crystallizer 2 can be reduced, thereby facilitating the smooth casting.

[0102] The present invention also discloses a method for casting an aluminum alloy bar, which utilizes the aluminum alloy bar diameter reducing casting device in the above embodiment. Figure 5-12 As shown, the steps include:

[0103] S1, installing the traction head forming mold 41 to the second end of the diameter reducing cavity 311, and assembling it with the power device 42.

[0104] In this embodiment, one end of the traction rod 421 is connected to the traction head molding die 41 , and the other end is connected to the traction wheel. The traction wheel drives the traction rod 421 to translate, thereby driving the traction head molding die 41 to enter the second end of the reducing cavity 311 .

[0105] S2. The liquid aluminum alloy in the tundish 1 flows into the crystallizer 2 to form a dual-state aluminum alloy rod in which the surface layer P2 is solid and the core P1 is liquid. Under the action of gravity, the liquid aluminum alloy in the core P1 drives the solidified aluminum alloy in the surface layer P2 to slide into the first sleeve 31.

[0106] S3. The first sleeve 31 is cooled by the cooling module 32. Under the cooling effect, the liquid aluminum alloy continues to gradually cool and solidify from the surface layer P2 to the core P1. At the same time, the liquid aluminum alloy in the core P1 flows into the traction head forming mold 41 to form the traction head Q.

[0107] After passing through the crystallizer 2, the aluminum alloy rod with solidified outer surface enters the first sleeve 31 and undergoes plastic deformation. The aluminum alloy continues to cool and solidify under the influence of the cooling module 32 inside the first sleeve 31. The liquid aluminum alloy in the core P1 undergoes diameter reduction deformation while solidifying, thereby eliminating defects such as shrinkage produced after the solidification of the liquid aluminum alloy, and obtaining a rod with a denser structure. At the same time, the liquid aluminum alloy is used to flow into the traction head forming mold 41 during the initial solidification process to form a traction head Q. The traction head Q is tightly connected to the aluminum alloy rod body and can bear a greater traction force. At the same time, the traction process is more stable, thereby ensuring the continuity of the aluminum alloy rod during the continuous casting process.

[0108] S4. When the traction head Q is completely formed, the power device 42 drives the pulling head in the traction head forming die 41 to pull the aluminum alloy rod out of the tissue control device 3.

[0109] By adjusting the diameter reduction strain rate, the grain size of the aluminum alloy bar can be accurately controlled so that it maintains a relatively uniform structure throughout the casting process. An appropriate diameter reduction strain rate can effectively avoid excessive or uneven grain size, thereby improving the mechanical properties and processability of the aluminum alloy bar.

[0110] The aluminum alloy bar casting method disclosed in the present invention has significant advantages, especially in eliminating internal defects of aluminum alloy, grain refinement, improvement of organizational uniformity, stability of traction process and mechanical properties. The synergistic effect of plastic deformation in the diameter reduction cavity 311 and the cooling and solidification process effectively improves the internal quality of the aluminum alloy, the close connection of the traction head Q enhances the traction force and casting stability of the aluminum alloy, and the precise control of the traction rate by the power device 42 ensures the organizational uniformity of the aluminum alloy bar during the entire casting process.

[0111] In terms of the process for realizing the rod drawing process, the present invention also specifically discloses the following implementation process.

[0112] Specifically, step S4 also includes the following steps:

[0113] S41, make the polarity of the electromagnetic traction plate 423 opposite to the polarity of the first electromagnet C1 and the second electromagnet C2, and the electromagnetic traction plate 423 realizes the connection between the traction rod 421 and the traction head forming mold 41 by mutual magnetic attraction with the first electromagnet C1 and the second electromagnet C2. Figure 7 shown.

[0114] S42, the traction wheel drives the traction rod to drive the traction head forming die 41 to move horizontally, and the aluminum alloy rod is pulled out of the tissue control device 3 at a certain speed; this step can be referred to in the attached Figure 8 shown.

[0115] S43, when the available rod length meets the requirement, the discharge port of the tundish 1 is closed, and when the aluminum alloy rod is completely pulled out of the tissue control device 3, the traction wheel stops moving;

[0116] Specifically, the discharge port of the tundish 1 can be closed by the gate 11 .

[0117] S44, cutting off the non-full cylindrical area formed at the end of the rod. Fig. 9 shown.

[0118] Specifically, this area is the part where the rod is shrunk, and the tail end of the rod is not a full cylinder, indicating that the internal structure of the rod is not completely solidified, and this part does not meet the requirements and needs to be cut off. The length of this part is the total length of the crystallizer 2. The cut aluminum alloy material can be put back into the smelting furnace for remelting and use.

[0119] S45, the connection between the traction rod and the traction head forming mold 41 is disconnected by meshing the gear set 52 with the teeth 51 on the die 411, and the traction head forming mold 41 is driven by the gear set 52 to rotate, so that the traction head Q is separated from the rod body; this step can be referred to in the attached Figure 9-11 shown.

[0120] Before the gear set 52 drives the traction head forming mold 41 to rotate, the effective rod part needs to be fixed in position to prevent it from rotating along with the traction head forming mold 41 .

[0121] S46, the electromagnetic traction disc 423 on the traction rod is adsorbed by the second electromagnet C2 on the punch 412, and the punch 412 is pulled out by the traction rod, the connection between the traction rod and the punch 412 is disconnected, and the traction head Q is separated from the punch 412; this step can be referred to in the attached Fig.12 shown.

[0122] In this step, the traction rod 421 is brought close to the traction head molding mold 41 so that the electromagnetic traction disk 423 is only attracted to the second magnet, and then the traction rod 421 drives the punch 412 to be removed from the die 411. When the electromagnetic traction disk 423 and the second magnet are powered off, the entire punch 412 will fall off and the two mold halves 4120 will separate. At this time, the traction head Q will be separated from the mold halves 4120.

[0123] S47, reinstall the male die 412 into the female die 411, and then drive the traction head forming die 41 to move to the second end of the diameter-reducing cavity 311 through the traction rod 421;

[0124] S48, opening the discharge port of the tundish 1, and casting the next aluminum alloy bar.

[0125] The above method optimizes the casting quality and production efficiency of aluminum alloy bars by accurately controlling the pulling and separation process of aluminum alloy bars. Specifically, the electromagnetic traction system and mechanical drive are combined to ensure the precise connection and separation between the traction head Q and the aluminum alloy bar, avoiding uneven stress or material damage during the stretching process; at the same time, by controlling the discharge port of the tundish 1 and cutting off the tail end of the non-full cylinder, the generation of defective areas is effectively avoided, and the quality of the bar is improved. This method can efficiently and stably complete the continuous casting of aluminum alloy bars and ensure that the quality of each bar meets the requirements.

[0126] As some preferred embodiments, when the rod passes through the second sleeve 33, the temperature of the surface of the rod after diameter reduction is controlled by the temperature control module 34, and a temperature gradient is formed along the diameter direction or length direction of the rod. In conjunction with the moving rate of the traction head forming die 41, different regions of the rod undergo recrystallization and grain growth to varying degrees, ultimately producing an aluminum alloy rod with a gradient grain size distribution.

[0127] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A diameter-reducing casting device for aluminum alloy bars, comprising a tundish (1) and a crystallizer (2), wherein the feed port of the crystallizer (2) is connected to the discharge port of the tundish (1), and characterized in that: It also includes a tissue control device (3) and a traction device (4); The tissue control device (3) comprises a first sleeve (31) and a cooling module (32); the first sleeve (31) has a diameter-reducing cavity (311) which is arranged through the first sleeve (31); the diameter-reducing cavity (311) has a first end and a second end; the inner diameter of the diameter-reducing cavity (311) gradually decreases from the first end to the second end; the first end of the diameter-reducing cavity (311) is connected to the discharge port of the crystallizer (2) in the horizontal direction; the cooling module (32) is arranged on the first sleeve (31) and is used for cooling and solidifying the solid-liquid aluminum alloy bar inside the diameter-reducing cavity (311); The traction device (4) comprises a traction head forming die (41) and a power device (42); at least a portion of the traction head forming die (41) is located at the second end of the diameter reducing cavity (311) and is used to form a traction head (Q) at the end of the aluminum alloy bar; the power device (42) is used to drive the traction head forming die (41) to move horizontally in a direction away from the crystallizer (2) in the first sleeve (31), so as to pull the aluminum alloy bar out of the tissue control device (3) through the traction head in the traction head forming die (41); The traction head forming die (41) comprises a concave die (411) and a convex die (412); The central axis of the concave mold (411) is provided with a conical hole (4111) extending therethrough, the inner diameter of the conical hole (4111) gradually increasing from an end facing the first sleeve (31) to an end away from the first sleeve (31), and the inner wall of the conical hole (4111) is provided with a plurality of grooves (4112) at equal intervals around the central axis; The punch (412) is inserted into the tapered hole (4111), and the punch (412) is composed of two symmetrically matched mold halves (4120). The outer surface of the mold halves (4120) has a tapered surface (4121) that matches the tapered hole (4111), and the tapered surface (4121) is provided with a protrusion (4122) that matches the groove (4112). The opposite sides of the two mold halves (4120) are symmetrically provided with a mold cavity (4123) for forming a traction head (Q).

2. The aluminum alloy bar diameter reducing casting device according to claim 1, characterized in that: The power device (42) comprises a traction rod (421) and a traction wheel (422); The end surface of the concave die (411) where the major diameter of the tapered hole (4111) is located has a first electromagnet (C1) with an annular structure; A second electromagnet (C2) with a semicircular structure is arranged on the end surface where the major diameter of the mold half (4120) is located; Two traction wheels (422) are symmetrically arranged and are located on a side of the tissue control device (3) away from the crystallizer (2); One end of the traction rod (421) passes through two traction wheels (422) and can move horizontally under the drive of the traction wheels (422). The other end of the traction rod (421) is provided with an electromagnetic traction disc (423). The electromagnetic traction disc (423) interacts with a first electromagnet (C1) and a second electromagnet (C2) to achieve connection or separation between the traction rod (421) and the traction head forming mold (41).

3. The aluminum alloy bar diameter reducing casting device according to claim 2, characterized in that: It also includes a separation device (5), wherein the separation device (5) includes teeth (51) and a gear set (52); The teeth (51) are arranged on the outer peripheral surface of one end of the die (411) away from the first sleeve (31), and the outer diameter of the teeth (51) is smaller than the outer diameter of the die (411); The gear set (52) is located between the tissue control device (3) and the traction wheel (422), and comprises at least three driving gears (521) evenly arranged around the central axis of the concave mold (411). The driving gears (521) can adjust the position between the concave mold (411). The driving gears (521) are used to mesh with the teeth (51) to drive the traction head forming mold (41) to rotate, thereby realizing the separation of the traction head (Q) from the rod body.

4. The aluminum alloy bar diameter reducing casting device according to claim 3, characterized in that: The tissue control device (3) further comprises a second sleeve (33) and a temperature control module (34); the second sleeve (33) is horizontally fixedly arranged at one end of the first sleeve (31) away from the crystallizer (2); the second sleeve (33) has a cylindrical cavity (331) arranged through it, and the cylindrical cavity (331) is connected to the diameter-reducing cavity (311); the temperature control module (34) is arranged on the second sleeve (33) and is used for controlling the temperature of the surface of the aluminum alloy bar entering the second sleeve (33).

5. The aluminum alloy bar diameter reducing casting device according to claim 1, characterized in that: A gate (11) is provided between the discharge port of the tundish (1) and the feed port of the crystallizer (2).

6. The aluminum alloy bar diameter reducing casting device according to claim 1, characterized in that: The crystallizer (2) comprises a cylinder (21) and a graphite pipe (22) fixedly arranged on the inner wall of the cylinder (21); the outer wall of the cylinder (21) is provided with a lubricant channel (211) connected to the inner wall of the graphite pipe (22); and a cooling chamber (212) is also provided between the cylinder (21) and the graphite pipe (22).

7. A method for casting an aluminum alloy bar, which utilizes the aluminum alloy bar diameter reducing casting device according to any one of claims 4 to 6, characterized in that: The steps include: S1, installing the traction head forming mold (41) to the second end of the diameter reducing cavity (311), and assembling it with the power device (42); S2, the liquid aluminum alloy solution in the tundish (1) flows to the crystallizer (2), and a dual-state aluminum alloy bar is formed in the crystallizer (2), wherein the surface layer (P2) is solid and the core (P1) is liquid. Under the action of gravity, the liquid aluminum alloy in the core (P1) drives the solidified aluminum alloy in the surface layer (P2) to slide into the first sleeve (31); S3, cooling the first sleeve (31) by means of a cooling module (32), so that the liquid aluminum alloy gradually cools and solidifies from the surface layer (P2) to the core (P1) under the cooling effect, and at the same time, the liquid aluminum alloy in the core (P1) flows into the traction head forming mold (41) to form a traction head (Q); S4. When the pulling head (Q) is completely formed, the power device (42) drives the pulling head in the pulling head forming die (41) to pull the aluminum alloy rod out of the tissue control device (3).

8. The aluminum alloy bar casting method according to claim 7, characterized in that: Step S4 also includes the following steps: S41, making the polarity of the electromagnetic traction disc (423) opposite to the polarity of the first electromagnet (C1) and the second electromagnet (C2), so that the electromagnetic traction disc (423) realizes the connection between the traction rod (421) and the traction head forming mold (41) by mutual magnetic attraction with the first electromagnet (C1) and the second electromagnet (C2); S42, the traction wheel (422) drives the traction rod (421) to drive the traction head forming die (41) to move horizontally, so as to pull the aluminum alloy rod out of the tissue control device (3) at a certain speed; S43, when the available rod length meets the requirement, the discharge port of the tundish (1) is closed, and when the aluminum alloy rod is completely pulled out of the tissue control device (3), the traction wheel (422) stops moving; S44, cutting off the non-full cylindrical area formed at the tail end of the rod; S45, the connection between the traction rod (421) and the traction head forming mold (41) is disconnected by meshing the gear set (52) with the teeth (51) on the concave mold (411), and the traction head forming mold (41) is driven by the gear set (52) to rotate, so that the traction head (Q) is separated from the rod body; S46, the electromagnetic traction disc (423) on the traction rod (421) is adsorbed by the second electromagnet (C2) on the punch (412), and the punch (412) is pulled out by the traction rod (421), the connection between the traction rod (421) and the punch (412) is disconnected, and the traction head (Q) is separated from the punch (412); S47, reinstalling the male die (412) into the female die (411), and then driving the traction head forming die (41) to move to the inside of the second end of the diameter reducing cavity (311) through the traction rod (421); S48, opening the discharge port of the tundish (1) to cast the next aluminum alloy bar.

9. The aluminum alloy bar casting method according to claim 7 or 8, characterized in that: When the rod passes through the second sleeve (33), the temperature of the surface of the reduced rod is controlled by the temperature control module (34), and a temperature gradient is formed along the diameter direction or the length direction of the rod. In combination with the moving speed of the traction head forming die (41), different regions of the rod undergo recrystallization and grain growth to different degrees, and finally an aluminum alloy rod with a gradient grain size distribution is produced.

Images