Blank swing rolling production method of aluminum alloy hub

Abstract

The invention discloses a blank swing-grinding production method of an aluminum alloy hub, a hub swing-grinding mold is adopted, the hub swing-grinding mold comprises an upper mold and a lower mold, the upper mold is arranged in a lifting manner relative to the lower mold, a forming cavity in the shape of a rotary body is formed between the lower mold and the upper mold when the upper mold descends in place, and a material returning rod arranged in a lifting manner is arranged at the axis of the forming cavity in the lower mold; a positioning groove coaxial with the material returning rod is formed in the upper end of the material returning rod, a parting angle coaxial with the positioning groove is arranged at the lower end of the upper die, and the production method comprises the following steps that A, a bar is formed, and the diameter of the bar is matched with the diameter of the positioning groove; b, bar heating is conducted, specifically, the bar is heated to a certain temperature, and the specific heat preservation time is maintained; c, swing grinding forming is conducted, specifically, the heated bar is placed in a positioning groove, the upper die swings and presses downwards till the bar is flattened to be completely attached to the wall face of the forming cavity, and a blank is formed; and D, material returning: the upper die ascends and resets, and a material returning rod pushes out the blank upwards. The method has the advantage that the process cost of swing grinding forming of the hub is reduced.

Description

Technical Field

[0001] The invention relates to the technical field of wheel hub production methods, in particular to a blank swing rolling production method of an aluminum alloy wheel hub. Background Art

[0002] Wheel hubs are usually produced by casting and forging. However, the strength of the wheel hubs is usually poor in the casting method, and it is easy to have casting defects and low production efficiency. The forging method has the problem of high cost. Therefore, some people have proposed to use the swing rolling method to produce wheel hubs. Swing rolling is referred to as swing rolling, which can also be called axial rolling. It is a plastic processing technology that uses a conical, rotatable upper die to locally pressurize the blank to achieve the purpose of gradual forming. It belongs to the continuous local loading forming method.

[0003] For example, in the Chinese patent literature, the invention patent with patent number CN2018101167912 discloses a forging method for a metallurgical mining wheel, which includes the following steps: (1) blanking and upsetting: blanking round steel by a band saw; (2) swing rolling: the pre-upsetting blank obtained in step (1) is first subjected to an annealing treatment, a surface passivation treatment and a lubrication treatment process in sequence, and then the pre-upsetting blank is placed in a swing rolling machine for swing rolling; (3) turning: the pre-upsetting blank obtained in step (2) is subjected to a The cold-rolled workpiece is drilled, and then the outer surface of the cold-rolled workpiece is subjected to rough turning, semi-finishing turning and finishing turning in sequence to obtain a tapered turned part; the tapered turned part is then subjected to secondary annealing treatment, secondary surface passivation treatment and secondary lubrication treatment processes in sequence; (4) milling processing: the side of the tapered turned part obtained in step (3) away from the wheel rim is subjected to milling processing by a milling machine to obtain a fan-shaped hole and a wheel hub to obtain a milled part; (5) grinding processing; (6) heat treatment: the ground part in step (5) is carburized and quenched to obtain a workpiece.

[0004] The existing technology is limited to multiple forming, which is divided into rod material - preheating - roughening - heating - forming. The shortcomings of the existing technology are: two heating treatments are added in the middle, the process is relatively cumbersome and the cost is high. Summary of the invention

[0005] In order to overcome the above-mentioned deficiencies in the prior art, the present invention provides a method for producing a blank of an aluminum alloy wheel hub by swing rolling, which can complete the forming of the aluminum alloy wheel hub by swing rolling once, thereby reducing the process cost of the wheel hub swing rolling forming.

[0006] In order to achieve the above object, the present invention adopts the following technical solutions.

[0007] A method for producing a blank of an aluminum alloy wheel hub by swing rolling, adopting a wheel hub swing rolling mold, the wheel hub swing rolling mold comprising an upper mold and a lower mold relative to each other, the upper mold being arranged to be lifted relative to the lower mold, a forming cavity in the shape of a rotating body being formed between the lower mold and the upper mold when the upper mold is lowered into place, a material stripping rod arranged to be lifted and lowered is provided at the axis of the forming cavity in the lower mold, a positioning groove coaxial with the material stripping rod is provided at the upper end of the material stripping rod, and a parting angle coaxial with the positioning groove is provided at the lower end of the upper mold, the blank swing rolling production method comprising the following steps: A. Bar forming, the diameter of the bar matches the diameter of the positioning groove; B. Heating the bar material: heating the bar material to a certain temperature and maintaining it for a specific insulation time; C. Swing rolling forming: place the heated bar into the positioning groove, and swing the upper die down until the bar is flattened to completely fit the wall of the cavity to form a blank; D. Material withdrawal: the upper die rises and resets, and the material withdrawal rod pushes the blank upward.

[0008] The present application sets a material return rod in the lower die, and a positioning groove is set on the upper end of the material return rod to match the rods with the same diameter. The upper die is set to rise and fall relative to the lower die and can press downward. At the same time, the dividing angle in the upper die is coaxial with the positioning groove, so that the rods can be diverted more evenly, thereby ensuring the quality of the wheel hub swing rolling forming. After using the above-mentioned mold, in the production method adopted by the present application, the rods only need to be heated and kept warm once, and there is no need to pierce the material and preheat. The aluminum alloy wheel hub blank is formed in one swing rolling, the production efficiency is high, and there is no need for multiple heating, which reduces the process cost of the wheel hub swing rolling forming.

[0009] Preferably, in step B, the heating temperature of the bar is 500° C.-530° C. The melting point of the aluminum alloy material for the hub is approximately between 568° C. and 660.4° C. The heating temperature of 500° C. to 530° C. can soften the bar and reduce the rigidity of the bar, while avoiding the melting of the bar and facilitating the swing and rolling processing of the bar.

[0010] Preferably, in step B, the heating time of the bar material from zero degrees is 1.2*(diameter+height) / 2(min), and the heat preservation time is: 1*diameter(min). The heating time and heat preservation time of the bar material are affected by the size of the bar material. The larger the size of the bar material, the longer the heating time; the larger the diameter of the bar material, the longer the heat preservation time, so as to ensure the reliability of the subsequent swing rolling processing of the bar material.

[0011] Preferably, in step C, the swing speed of the upper die is 1 rps, and the descending speed of the upper die is 2 mm / s. The upper die is the main force-applying component for rolling the bar into a blank. The swing speed and descending speed of the upper die directly determine the speed and quality of the rolling forming of the bar. After adopting the preferred parameters, the upper die can reliably roll the bar and the forming rate is fast.

[0012] Preferably, in step C, the swing amplitude of the upper mold is 1 to 3 degrees; the swing trajectory of the upper mold is circular. The swing amplitude of the upper mold is small, and the swing rolling effect is reliable when the upper mold is lowered, and the molding cavity structure is fully utilized, and the swing rolling quality is high.

[0013] Preferably, the lower end of the upper die is provided with an upper forming surface, and the upper forming surface is provided with a parting angle, a material expansion surface and a material return surface in sequence from its axis outward, the material expansion surface is inclined from bottom to top in the direction outward from the axis of the upper forming surface, and the material return surface is inclined from top to bottom in the direction outward from the axis of the upper forming surface. When the upper die is pressed down, the upper end of the bar stock is pressed by the upper forming surface to guide the bar stock during the swing rolling process, the parting angle is coaxial with the material return rod and the bar stock, the parting angle first contacts the upper end of the bar stock, and the parting angle is inserted into the bar stock from the axis of the bar stock downward to achieve uniform separation of the bar stock in the circumferential direction, and then the bar stock flows outward under the action of the material expansion surface, and flows downward under the action of the material return, so that the bar stock fully cooperates with the lower die to ensure the quality of swing rolling forming.

[0014] Preferably, the taper angle of the parting angle is smaller than the taper angle of the expansion surface, and a first transition fillet is provided between the parting angle and the expansion surface to achieve a smooth transition between the parting angle and the expansion surface. The parting angle mainly plays the role of piercing the bar material, so the taper angle is relatively small, while the expansion surface mainly plays the role of expanding the material, so the taper angle is relatively large. With the setting of the first transition fillet, after the parting angle is penetrated, as the upper die continues to move downward, the material flows smoothly to the expansion surface, and expands to the forming cavity under the action of the expansion surface, thereby ensuring the quality of the blank forming.

[0015] Preferably, a second transition fillet is provided at the junction of the material expansion surface and the material return surface, and the junction of the material expansion surface and the material return surface corresponds to the upper side of the positioning groove wall. The second transition fillet realizes the smooth transition of the material from the material expansion surface to the material return surface, and there is a material turning at the junction of the material expansion surface and the material return surface. Since the size of the positioning groove matches the diameter of the bar, the junction of the material expansion surface and the material return surface just corresponds to the outer periphery of the bar, and with the limiting effect of the positioning groove on the lower end of the bar, the forces of the material expansion surface and the material return surface on the material in different directions in the lateral direction are borne by the positioning groove, which will not cause the position of the bar to be cheap, and ensure the quality of the bar swing rolling forming.

[0016] Preferably, the outer end of the upper forming surface is provided with a pressing table surface with an inclination angle with the horizontal plane greater than that of the material return surface, so as to further improve the material return efficiency of the material return surface.

[0017] Preferably, a frustum is provided at the outer end of the wall of the lower die corresponding to the forming cavity, the cone angle of the frustum faces downward and the cone angle ranges from 6 to 15 degrees. The frustum is located at the outer end of the forming cavity, which is convenient for the upper die and the blank to be removed, ensuring that the blank after the swing rolling forming will not have quality defects due to the removal of the material.

[0018] The invention has the advantages that the forming of the aluminum alloy wheel hub can be completed by swing rolling at one time, the swing rolling forming efficiency is high, multiple heating is not required, and the process cost of the swing rolling forming of the wheel hub is reduced; and the swing rolling forming quality is high. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 The invention discloses a schematic flow chart of a production method for a blank of an aluminum alloy wheel hub by swing rolling.

[0020] Figure 2 The present invention is a schematic structural diagram of a wheel hub swing rolling mold before swing rolling, which is used in the method for producing a blank of an aluminum alloy wheel hub disclosed in the present invention.

[0021] Figure 3 yes Figure 2 A magnified schematic diagram of center A.

[0022] Figure 4 The present invention is a schematic structural diagram of an upper die and a lower die in a wheel hub swing rolling die used in a method for producing a blank swing rolling of an aluminum alloy wheel hub disclosed in the present invention, in which an upper die and a lower die are opposite to each other.

[0023] Figure 5 The invention is a schematic structural diagram of a wheel hub swing rolling mold used in the method for producing a blank of an aluminum alloy wheel hub disclosed in the invention after swing rolling.

[0024] In the figure: upper die 1, upper forming surface 2, parting angle 3, material expansion surface 4, material return surface 5, lower pressing table 6, first transition fillet 7, second transition fillet 8, lower die 9, lower forming surface 10, easy-push surface 11, step hole 12, forming cavity 13, ejector rod 14, positioning groove 15, positioning section 16, guide section 17, bar material 18, blank 19. DETAILED DESCRIPTION

[0025] The technical solutions of the embodiments of the present invention are explained and described below in conjunction with the drawings of the embodiments of the present invention, but the following embodiments are only preferred embodiments of the present invention, not all. Based on the embodiments in the implementation mode, other embodiments obtained by those skilled in the art without creative work are all within the protection scope of the present invention.

[0026] In the description of this embodiment, it should be noted that, if the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", "front", "back", etc. appear, the orientation or position relationship indicated is based on the orientation or position relationship shown in the drawings, which is only for the convenience of describing the present invention and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore, it cannot be understood as a limitation on the present invention. In addition, if the terms "first", "second", and "third" appear, they are only used for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0027] Swing rolling is a processing method that uses a conical upper die that rolls rapidly around the center to locally pressurize the end face of the blank to gradually shape it. During swing rolling, the workpiece is locally stressed, deformed within a small contact area, and gradually expands in a spiral surface. The deformation process is the gradual accumulation of small deformations. The ultimate deformation degree is 10% to 15% higher than that of the commonly used forging method, and the required deformation force is only 1 / 20 to 1 / 5 of that of the commonly used forging equipment. In the prior art, when the wheel hub is swing-rolled, if a limit is directly set at the bottom of the lower die forming cavity, quality defects are prone to occur. Therefore, the stability of the bar during swing rolling is usually improved by roughening the bar. The bar needs to be heated before roughening, and the bar needs to be heated again and kept warm during swing rolling. The process is relatively complicated, and the repeated heating method also consumes a lot of energy.

[0028] In view of the above-mentioned deficiencies in the prior art, the present application provides a Figure 1 The blank 19 swing rolling production method of the aluminum alloy wheel hub shown in the figure adopts the following method: Figures 2 to 5 The wheel hub swing rolling mold shown in the figure comprises an upper mold 1 and a lower mold 9 which are opposite to each other. The upper mold 1 is lifted relative to the lower mold 9. When the upper mold 1 is lowered into place, a forming cavity 13 in the shape of a rotating body is formed between the lower mold 9 and the upper mold 1. A lifting and discharging rod 14 is provided at the axis of the forming cavity 13 in the lower mold 9. A positioning groove 15 which is coaxial with the discharging rod 14 is provided at the upper end of the discharging rod 14. A parting angle 3 which is coaxial with the positioning groove 15 is provided at the lower end of the upper mold 1. The production method of the swing rolling of the blank 19 comprises the following steps: A. The bar 18 is formed, and the diameter of the bar 18 matches the diameter of the positioning groove 15, such as Figure 2 As shown; B. Heating the bar 18, heating the bar 18 to a certain temperature and maintaining the temperature for a specific holding time; C. Swing rolling forming: the heated bar 18 is placed in the positioning groove 15, and the upper mold 1 is swung and pressed down until the bar 18 is flattened to completely fit the wall of the cavity 13 to form a blank 19. Figure 5 As shown; D. Material withdrawal: the upper die 1 rises and resets, and the material withdrawal rod 14 pushes the blank 19 upward.

[0029] The wheel hub swing roller mold of the present application is applied to the swing roller. The overall structure of the swing roller is similar to that of a hydraulic press. It is composed of a swing head and its transmission system, a closed extrusion component, a hydraulic cylinder force component, a hydraulic transmission system and an electrical control system. The difference between it and a general hydraulic press is that it has an additional set of swing head components. Except for the swing head, its design calculation is basically the same as that of a general hydraulic press. The swing roller is a mature prior art and does not involve the improved technical points of the present application, so it will not be elaborated.

[0030] The present application sets a material removal rod 14 in the lower die 9 at the axis of the forming cavity 13, and the material removal rod 14 is set to rise and fall relative to the lower die 9. A positioning groove 15 is set at the upper end of the material removal rod 14, and the diameter of the positioning groove 15 is equal to the diameter of the rod 18. The two can be matched with clearance. The rod 18 will be heated during processing, and will fit the positioning groove 15 after a certain degree of thermal expansion. When the rod 18 is in the positioning groove 15, the lower end is limited by the groove wall of the positioning groove 15, which can offset the lateral force generated by the swing of the upper die 1 to a certain extent, so that the rod 18 does not need to go through the heating and roughening process first. During the swing rolling, the positioning groove 15 ensures the stability of the position of the rod 18, and then ensures the quality of the swing rolling of the blank 19. Through the production method of the present application, the production cost of swing rolling manufacturing of aluminum alloy wheel hubs can be reduced, and the production efficiency is high and the production accuracy is reliable.

[0031] As one of the embodiments of the present invention, a method for producing a blank 19 of an aluminum alloy wheel hub by swing rolling is provided. Figures 2 to 5 The wheel hub swing rolling mold shown in the figure comprises an upper mold 1 and a lower mold 9 which are opposite to each other. The upper mold 1 is lifted relative to the lower mold 9. When the upper mold 1 is lowered into place, a forming cavity 13 in the shape of a rotating body is formed between the lower mold 9 and the upper mold 1. A lifting and discharging rod 14 is provided at the axis of the forming cavity 13 in the lower mold 9. A positioning groove 15 which is coaxial with the discharging rod 14 is provided at the upper end of the discharging rod 14. A parting angle 3 which is coaxial with the positioning groove 15 is provided at the lower end of the upper mold 1. The production method of the swing rolling of the blank 19 comprises the following steps: A. The bar 18 is formed, and the diameter of the bar 18 matches the diameter of the positioning groove 15; B. Heating the bar 18, heating the bar 18 to a certain temperature and maintaining the temperature for a specific holding time; C. Swing rolling forming: the heated bar 18 is placed in the positioning groove 15, and the upper mold 1 is swung and pressed down until the bar 18 is flattened to completely fit the wall of the cavity 13 to form a blank 19; D. Material withdrawal: the upper die 1 rises and resets, and the material withdrawal rod 14 pushes the blank 19 upward.

[0032] In step B, the heating temperature of the bar 18 is 500°C. The heating time of the bar 18 from zero degrees is 1.2*(diameter+height) / 2(min), and the heat preservation time is: 1*diameter(min). In this embodiment, the height of the bar 18 is 245 mm, the diameter of the bar 18 is 176 mm, and the height of the outer end of the blank 19 corresponding to the parting angle 3 after the swing rolling is 24 mm. After substituting the parameters, it can be calculated that the heating time of the bar 18 from zero degrees is 252.6 minutes, that is, 4.21 hours, and the heat preservation time is 176 minutes.

[0033] In step C, the swing speed of the upper die 1 is 1 rps, the descending speed of the upper die 1 is 2 mm / s, the swing amplitude of the upper die 1 is 2 degrees, and the swing trajectory of the upper die 1 is circular. The upper die 1 is the main force-applying component for rolling the bar 18 into the blank 19. The swing speed and descending speed of the upper die 1 directly determine the speed and quality of the swing rolling of the bar 18. After adopting these parameters, the upper die 1 forms a reliable swing rolling of the bar 18, and the forming rate is fast. When rolling, the height of the upper die 1 is 221 mm, so the duration of the descent of the upper die 1 during the swing rolling is 110.5 seconds.

[0034] The heating temperature of the bar 18 is lower than the melting point of the aluminum alloy material. Keeping the bar 18 warm at this temperature can eliminate the internal stress of the bar 18. Then the bar 18 is hot-rolled. The strength of the bar 18 is lower than that at low temperature. The rolling efficiency is high and the required rolling manufacturing accuracy is easy to achieve. After step B and step C, the center plate of the aluminum alloy wheel hub can be processed by rolling at one time, and the production efficiency is high.

[0035] As one of the embodiments of the present invention, a method for producing a blank 19 of an aluminum alloy wheel hub by swing rolling is provided. Figures 2 to 5 The wheel hub swing rolling mold shown in the figure comprises an upper mold 1 and a lower mold 9 which are opposite to each other. The upper mold 1 is lifted relative to the lower mold 9. When the upper mold 1 is lowered into place, a forming cavity 13 in the shape of a rotating body is formed between the lower mold 9 and the upper mold 1. A lifting and discharging rod 14 is provided at the axis of the forming cavity 13 in the lower mold 9. A positioning groove 15 which is coaxial with the discharging rod 14 is provided at the upper end of the discharging rod 14. A parting angle 3 which is coaxial with the positioning groove 15 is provided at the lower end of the upper mold 1. The production method of the swing rolling of the blank 19 comprises the following steps: A. The bar 18 is formed, and the diameter of the bar 18 matches the diameter of the positioning groove 15; B. Heating the bar 18, heating the bar 18 to a certain temperature and maintaining the temperature for a specific holding time; C. Swing rolling forming: the heated bar 18 is placed in the positioning groove 15, and the upper mold 1 is swung and pressed down until the bar 18 is flattened to completely fit the wall of the cavity 13 to form a blank 19; D. Material withdrawal: the upper die 1 rises and resets, and the material withdrawal rod 14 pushes the blank 19 upward.

[0036] In this embodiment, the height of the bar 18 is 245 mm, the diameter of the bar 18 is 176 mm, and the height of the blank 19 corresponding to the outer end of the parting angle 3 after the swing rolling is 24 mm. In step B, the heating temperature of the bar 18 is 530° C. In step B, the heating time of the bar 18 from zero degrees is 1.2*(diameter+height) / 2(min), and the heat preservation time is: 1*diameter(min).

[0037] Step C, the swing speed of the upper mold 1 is 1 rps, the descending speed of the upper mold 1 is 2 mm / S, the swing amplitude of the upper mold 1 is 2 degrees; and the swing trajectory of the upper mold 1 is circular.

[0038] The difference between this embodiment and the previous embodiment is that the heating temperature of the rod 18 is different. The size of the rod 18 in the two embodiments is the same. In actual application, for a larger wheel hub, a larger rod 18 is required, and a slightly higher heating temperature can be used to ensure the swing rolling efficiency.

[0039] As one of the embodiments of the present invention, a kind of blank 19 swing rolling production method proposed, adopts Figures 2 to 5 The wheel hub swing rolling mold shown in the figure comprises an upper mold 1 and a lower mold 9 which are opposite to each other. The upper mold 1 is lifted relative to the lower mold 9. When the upper mold 1 is lowered into place, a forming cavity 13 in the shape of a rotating body is formed between the lower mold 9 and the upper mold 1. A lifting and discharging rod 14 is provided at the axis of the forming cavity 13 in the lower mold 9. A positioning groove 15 which is coaxial with the discharging rod 14 is provided at the upper end of the discharging rod 14. A parting angle 3 which is coaxial with the positioning groove 15 is provided at the lower end of the upper mold 1. The production method of the swing rolling of the blank 19 comprises the following steps: A. The bar 18 is formed, and the diameter of the bar 18 matches the diameter of the positioning groove 15; B. Heating the bar 18, heating the bar 18 to a certain temperature and maintaining the temperature for a specific holding time; C. Swing rolling forming: the heated bar 18 is placed in the positioning groove 15, and the upper mold 1 is swung and pressed down until the bar 18 is flattened to completely fit the wall of the cavity 13 to form a blank 19; D. Material withdrawal: the upper die 1 rises and resets, and the material withdrawal rod 14 pushes the blank 19 upward.

[0040] In this embodiment, an upper molding surface 2 is provided at the lower end of the upper mold 1. The upper molding surface 2 is provided with a parting angle 3, a material expansion surface 4 and a material return surface 5 in sequence from its axis outward. The material expansion surface 4 is inclined from bottom to top in the outward direction of the axis of the upper molding surface 2, and the material return surface 5 is inclined from top to bottom in the outward direction of the axis of the upper molding surface 2. The shape of the upper molding surface 2 is a rotary structure. In this embodiment, the shape of the parting angle 3 is a conical angle, and a spherical fillet is provided at the end of the parting angle 3 to extend the service life of the parting angle 3. The material expansion surface 4 and the material return surface 5 are both frustum surfaces, and the cone angle of the material expansion surface 4 is greater than the cone angle of the parting angle 3 to provide a reliable material expansion effect, and the cone angle of the material return surface 5 is opposite to that of the material expansion surface 4, and the cone angle of the material return surface 5 is greater than the cone angle of the material expansion surface 4 to provide a relatively gentle material return effect. For example, Figure 2 In the upper die 1 shown, the taper angle of the parting angle 3 is 88 degrees, which is close to a right angle, has high strength, and is also an acute angle, which can ensure the parting effect on the bar 18. The taper angle of the expansion surface 4 is 122 degrees, and the taper angle of the return surface 5 is 168 degrees.

[0041] In this embodiment, the upper side surface of the lower mold 9 corresponding to the molding cavity 13 is the lower molding surface 10, and the shape of the lower molding surface 10 is a rotational structure, and the rotation generatrix of the lower molding surface 10 is a curve: from the axis to the outside, the rotation generatrix of the lower molding surface 10 is an approximate S-shaped curve that first goes upward, then downward, and then upward again.

[0042] Furthermore, the shape of the material return rod 14 is stepped, and the material return rod 14 includes a positioning section 16 at the upper end and a guide section 17 at the lower end. The diameter of the positioning section 16 is larger than the diameter of the guide section 17. A step hole 12 is provided in the lower mold 9 to match the material return rod 14, and the lower end of the limiting positioning section 16 is supported by the step hole 12. When the lower end of the positioning section 16 abuts against the wall of the step hole 12, the upper end of the material return rod 14 is seamlessly connected to the lower molding surface 10. The positioning groove 15 is located at the upper end of the positioning section 16, and the side wall of the positioning groove 15 is a cylindrical surface. When the lower end of the rod 18 is placed in the positioning groove 15, the side wall of the positioning groove 15 limits the lower end of the rod 18. When the upper die 1 descends, the parting angle 3 first contacts the bar 18, squeezing the upper end of the bar 18 outward, and when the upper die 1 descends to a certain extent, the circumference of the bar 18 contacts the lower forming surface 10, and cooperates with the structure of the lower forming surface 10 to achieve reliable swing rolling manufacturing. As a simple replacement for the above solution, the shape of the positioning section 16 can be a truncated cone or a hemispherical shape.

[0043] Furthermore, the outer end of the upper molding surface 2 is provided with a pressing table 6 having a greater inclination angle with the horizontal plane than the return surface 5. Specifically, the cone angle of the pressing table 6 is 160 degrees, that is, the inclination angle of the pressing table 6 with the horizontal plane is 4 degrees greater than the inclination angle of the return surface 5 with respect to the horizontal plane.

[0044] As a simple replacement for the above solution, the rotation generatrixes of the parting angle 3, the expansion surface 4 and the return surface 5 are all curves.

[0045] As one of the embodiments of the present invention, a kind of blank 19 swing rolling production method proposed, adopts Figures 2 to 5 The wheel hub swing rolling mold shown in the figure comprises an upper mold 1 and a lower mold 9 which are opposite to each other. The upper mold 1 is lifted relative to the lower mold 9. When the upper mold 1 is lowered into place, a forming cavity 13 in the shape of a rotating body is formed between the lower mold 9 and the upper mold 1. A lifting and discharging rod 14 is provided at the axis of the forming cavity 13 in the lower mold 9. A positioning groove 15 which is coaxial with the discharging rod 14 is provided at the upper end of the discharging rod 14. A parting angle 3 which is coaxial with the positioning groove 15 is provided at the lower end of the upper mold 1. The production method of the swing rolling of the blank 19 comprises the following steps: A. The bar 18 is formed, and the diameter of the bar 18 matches the diameter of the positioning groove 15; B. Heating the bar 18, heating the bar 18 to a certain temperature and maintaining the temperature for a specific holding time; C. Swing rolling forming: the heated bar 18 is placed in the positioning groove 15, and the upper mold 1 is swung and pressed down until the bar 18 is flattened to completely fit the wall of the cavity 13 to form a blank 19; D. Material withdrawal: the upper die 1 rises and resets, and the material withdrawal rod 14 pushes the blank 19 upward.

[0046] In this embodiment, the upper molding surface 2 is provided at the lower end of the upper mold 1, and the upper molding surface 2 is provided with a parting angle 3, a material expansion surface 4 and a material return surface 5 in sequence from its axis outward, the material expansion surface 4 is inclined from bottom to top in the direction outward from the axis of the upper molding surface 2, and the material return surface 5 is inclined from top to bottom in the direction outward from the axis of the upper molding surface 2. The taper angle of the parting angle 3 is smaller than the taper angle of the material expansion surface 4, and a first transition fillet 7 is provided between the parting angle 3 and the material expansion surface 4 to achieve a smooth transition between the parting angle 3 and the material expansion surface 4. A second transition fillet 8 is provided at the junction of the material expansion surface 4 and the material return surface 5, and the junction of the material expansion surface 4 and the material return surface 5 corresponds to the upper side of the groove wall of the positioning groove 15.

[0047] In this embodiment, since the groove wall of the positioning groove 15 corresponds to the outer wall of the bar 18, the junction of the expansion surface 4 and the return surface 5 corresponds to the upper side of the groove wall of the positioning groove 15, that is, the junction of the expansion surface 4 and the return surface 5 corresponds to the outer wall of the bar 18. Since the expansion surface 4 and the return surface 5 will produce forces in different directions in the lateral direction of the bar 18, in order to avoid displacement or deflection of the bar 18, the junction of the expansion surface 4 and the return surface 5 is set corresponding to the outer wall of the bar 18, so that there is a more concentrated downward force on the bar 18, thereby improving the quality of swing rolling. The setting of the first transition fillet 7 and the second transition fillet 8 makes the upper forming surface 2 smoother, which is convenient for the flow of materials during swing rolling.

[0048] As one of the embodiments of the present invention, a kind of blank 19 swing rolling production method proposed, adopts Figures 2 to 5 The wheel hub swing rolling mold shown in the figure comprises an upper mold 1 and a lower mold 9 which are opposite to each other. The upper mold 1 is lifted relative to the lower mold 9. When the upper mold 1 is lowered into place, a forming cavity 13 in the shape of a rotating body is formed between the lower mold 9 and the upper mold 1. A lifting and lowering material return rod 14 is provided at the axis of the forming cavity 13 in the lower mold 9. A positioning groove 15 which is coaxial with the material return rod 14 is provided at the upper end of the material return rod 14. A parting angle 3 which is coaxial with the positioning groove 15 is provided at the lower end of the upper mold 1. The outer end of the parting angle 3 is provided with a rounded corner. The production method of the swing rolling of the blank 19 comprises the following steps: A. The bar 18 is formed, and the diameter of the bar 18 matches the diameter of the positioning groove 15; B. Heating the bar 18, heating the bar 18 to a certain temperature and maintaining the temperature for a specific holding time; C. Swing rolling forming: the heated bar 18 is placed in the positioning groove 15, and the upper mold 1 is swung and pressed down until the bar 18 is flattened to completely fit the wall of the cavity 13 to form a blank 19; D. Material withdrawal: the upper die 1 rises and resets, and the material withdrawal rod 14 pushes the blank 19 upward.

[0049] In this embodiment, the upper molding surface 2 is provided at the lower end of the upper mold 1, and the upper molding surface 2 is provided with a parting angle 3, a material expansion surface 4 and a material return surface 5 in sequence from its axis outward, the material expansion surface 4 is inclined from bottom to top in the direction outward from the axis of the upper molding surface 2, and the material return surface 5 is inclined from top to bottom in the direction outward from the axis of the upper molding surface 2. The outer end of the wall surface of the lower mold 9 corresponding to the molding cavity 13 is provided with a truncated cone-shaped easy-push surface 11, the cone angle of the truncated cone surface is downward and the cone angle range of the truncated cone surface is between 6 and 15 degrees. The upper end of the easy-push surface 11 is a cylindrical surface. In this embodiment, the cone angle of the easy-push surface 11 is 10 degrees, which can facilitate the withdrawal of the blank 19 after the swing rolling molding, and at the same time can play a certain centering role, and cooperate with the swing of the upper mold 1 to play a reliable guiding role.

[0050] In the wheel hub swing rolling production method disclosed in the present application, the rod material 18 only needs to be heated and kept warm once, and there is no need to perform stabilization and preheating, thereby achieving one-time swing rolling forming of the aluminum alloy wheel hub blank 19, with high production efficiency and no need for multiple heating, thereby reducing the process cost of the wheel hub swing rolling forming.

Claims

1. A method for producing a blank of an aluminum alloy wheel hub by rolling, using a wheel hub rolling mold, the wheel hub rolling mold comprising an upper mold and a lower mold, characterized in that: The upper die is lifted relative to the lower die. When the upper die is lowered to a position, a forming cavity in the shape of a rotating body is formed between the lower die and the upper die. A lifting and lowering ejector rod is provided at the axis of the forming cavity in the lower die. A positioning groove coaxial with the ejector rod is provided at the upper end of the ejector rod. The blank swing rolling production method includes the following steps: A. Bar forming, the diameter of the bar matches the diameter of the positioning groove; B. Heating the bar material: heating the bar material to a certain temperature and maintaining it for a specific insulation time; C. Swing rolling forming: place the heated bar into the positioning groove, and swing the upper die down; D. Material withdrawal: the upper die rises and resets, and the material withdrawal rod pushes the blank upward.

2. The method for producing a blank of an aluminum alloy wheel hub by swing rolling according to claim 1, characterized in that: In the step B, the heating temperature of the rod is 500°C-530°C.

3. The method for producing a blank of an aluminum alloy wheel hub by swing rolling according to claim 1, characterized in that: In step B, the heating time of the bar material from zero degrees is 1.2*(diameter+height) / 2 (min), and the heat preservation time is: 1*diameter (min).

4. The method for producing a blank of an aluminum alloy wheel hub by swing rolling according to claim 1, characterized in that: In the step C, the swing speed of the upper mold is 1 rps, and the descending speed of the upper mold is 2 mm / S.

5. The method for producing a blank of an aluminum alloy wheel hub by swing rolling according to claim 1, characterized in that: In step C, the swing amplitude of the upper mold is 1 to 3 degrees; and the swing trajectory of the upper mold is circular.

6. A method for producing a blank of an aluminum alloy wheel hub by swing rolling according to any one of claims 1 to 5, characterized in that: The lower end of the upper mold is provided with an upper molding surface, and the upper molding surface is provided with a parting angle, a material expansion surface and a material return surface in sequence from its axis outward. The material expansion surface is inclined from bottom to top in the outward direction of the axis of the upper molding surface, and the material return surface is inclined from top to bottom in the outward direction of the axis of the upper molding surface.

7. The method for producing a blank of an aluminum alloy wheel hub by swing rolling according to claim 6, characterized in that: The taper angle of the parting angle is smaller than the taper angle of the expansion surface, and a first transition fillet is provided between the parting angle and the expansion surface to achieve a smooth transition between the parting angle and the expansion surface.

8. The method for producing a blank of an aluminum alloy wheel hub by swing rolling according to claim 6, characterized in that: A second transition fillet is provided at the junction of the material expansion surface and the material return surface, and the junction of the material expansion surface and the material return surface corresponds to the upper side of the positioning groove wall.

9. The method for producing a blank of an aluminum alloy wheel hub by swing rolling according to claim 6, characterized in that: The outer end of the upper forming surface is provided with a pressing table surface with an inclination angle with the horizontal plane greater than that of the material return surface.

10. The method for producing a blank of an aluminum alloy wheel hub by swing rolling according to claim 6, characterized in that: The outer end of the wall surface of the lower mold corresponding to the forming cavity is provided with a truncated cone-shaped easy-pushing surface, the cone angle of the truncated cone surface faces downward and the cone angle range of the truncated cone surface is between 6 and 15 degrees.

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