TWI717718B - Molding method and mold of aluminum alloy cast-forged wheel rim for mobile carrier - Google Patents

Abstract

The invention relates to an aluminum alloy cast-forged rim forming method for a mobile carrier and a casting mold thereof, which provide efficient production and manufacture. The method includes: a raw material melting step, which is to melt an aluminum-containing material into an aluminum soup; and a casting step , The lower mold is equipped with a riser pipe, and the aluminum soup is injected into the lower mold. A water-cooling module is installed around the outlet of the riser pipe to locally cool the aluminum soup in the lower mold. To obtain the aluminum broth with a specific solid-liquid ratio, at this time, an upper mold is used to squeeze the aluminum broth, finally cooling and demolding to obtain a first preform, and then plastic forming the first preform , After solution and aging heat treatment, a cast and forged rim is obtained; in this way, the problem that the traditional casting blank cannot use the precipitation hardening aluminum alloy for forging can be overcome.

Description

Molding method and mold of aluminum alloy cast-forged wheel rim for mobile carrier

The invention relates to a forming method of aluminum alloy cast-forged rims for a mobile carrier, in particular to a forming method that uses a rough blank, then forging and spinning forming.

According to, commercially available aluminum alloy wheels can be divided into forged wheels and cast wheels. Forged wheels use precipitation-hardened aluminum alloy AA6061, which can be used with complicated forging processes to produce forged wheels with good mechanical properties. The forged rim can achieve mechanical properties such as yield strength of 221MPA, tensile strength of 276MPA, and elongation of 7%. On the other hand, due to the use of the international standard die-cast aluminum alloy material A356 for the cast rim, the yield strength of the cast rim is only 130MPA, the tensile strength is only 201MPA, and the elongation rate is 7%. Therefore, the mechanical properties of the forged rim It is better than cast rims, but the manufacturing cost advantage of cast rims is better, while cast-forged rims have both the advantages of the aforementioned two rims.

The traditional method of low-pressure casting wheels is that the upper, lower and side molds must be completely closed before casting to fill the aluminum broth, and the aluminum broth is filled with a cast aluminum alloy formula with high silicon content, which can increase the aluminum broth. Mobility. After the aluminum broth is filled in the mold, only the pressure can be maintained. The aluminum broth no longer has fluidity, resulting in the subsequent cooling process, the casting blank is prone to shrinkage cavity and crystal segregation, etc. problem.

The Taiwanese Patent Preliminary TW200906511A teaches an "aluminum ring casting, forging and spinning method", which uses casting, forging, solution treatment, spinning forming, and aging treatment to manufacture vehicle aluminum rings, but its aluminum soup composition , Still need to formulate high silicon content casting ingredients (silicon content at least 3% or more) to make the blank material to achieve the formability of the cast crude blank; after that, the forging method is supplemented to increase the slight strength and elongation. However, considering that the aluminum alloy material used is not a precipitation hardening aluminum alloy for forging, it cannot meet the strength requirements of forged wheels.

Furthermore, the spinning forming taught in the TW200906511A document is to first solid-solution heat-treat the cast blank (including quenching water), then spin the tire ring, and finally perform the aging treatment, although the ductility of the cast blank after the solution treatment The increase can improve the yield rate of spinning forming, but it is still spinning forming under normal temperature conditions, and the failure rate is still high.

In addition, the previous Chinese patent CN103084559B teaches a "forging method for forging wheels with secondary pressure melting soup", which uses a robot to scoop aluminum soup and pour it into the cavity of the casting mold, and then pressurize the casting mold twice. For the first pressurization, the main cylinder is used to pressurize the aluminum broth once; for the second pressurization, the auxiliary cylinder is used for the second pressurization of the aluminum broth. The advantages of this method: since the aluminum soup is semi-solidified and pressurized, it can improve the formability and does not have to be limited to the use of aluminum alloys with high silicon content; however, its disadvantages: it is easy to scoop and pour the soup. A large amount of disturbance is generated to generate entrainment, so that there is a large amount of oxide film in the aluminum soup, and the oxide film greatly affects the quality of the casting blank, and cannot be removed by the primary and secondary pressurization process.

For this reason, in view of the above-mentioned conventional construction methods, the inventor of the present invention devotes himself to creating an aluminum alloy cast-forged wheel forming method and its mold for mobile vehicles. Therefore, the main purpose of the present invention is to provide a product that meets the requirements of traditional forged products. The casting and forging method of mechanical properties; the secondary purpose of the present invention is to use aluminum alloy for forging and to solve the problems of poor fluidity and serious segregation of the casting blank; another purpose of the present invention is to provide a comparative Casting and forging method with good material yield, manufacturing yield, casting and forging quality.

To achieve the above purpose, the present invention uses the following technical means: Regarding the method for forming aluminum alloy cast and forged wheels for mobile carriers of the present invention, the method includes: a raw material melting step, which is to melt an aluminum-containing material into an aluminum soup; and a casting step, which is to set a mold in a mold The aluminum broth is injected into the lower mold through the riser tube, and a water-cooling module is installed near the exit of the riser tube. The water-cooling module performs the aluminum broth The cooling effect is gradually reduced from near to far, and then an aluminum soup with a specific solid-to-liquid ratio is obtained. At this time, an upper mold set in the casting mold is used to squeeze the aluminum soup to prevent the aluminum soup from flowing back and blocking the rising liquid Finally, the whole casting mold is cooled and demolded to obtain a first preform; a plastic forming processing step is to perform precision forging and forming operations on the first preform at a temperature above the recrystallization temperature to obtain a A second primary blank; and a spinning forming step, which is to obtain a spinning blank by spinning forming; and a punching and trimming step to remove excess material on the disk surface; and a heat treatment step to obtain a spinning blank The embryo undergoes solid solution and aging treatment to become a cast-forged rim.

The above-mentioned method of injecting the aluminum broth into the lower mold by the riser pipe is a filling method in which the aluminum broth is smoothly pressed into the mold with an inert gas of 1 to 2 atmospheric pressure.

The mobile carrier uses an aluminum alloy cast-forged rim forming method, wherein the plastic forming processing step further includes a disk surface hot fine forging and shaping step and a hot spinning extension step.

The mobile carrier uses an aluminum alloy cast-forged rim forming method, wherein the flow channel of the water-cooled module is set to surround the vicinity of the outlet of the riser pipe and is embedded in the lower mold.

The mobile carrier uses an aluminum alloy cast-forged rim forming method, wherein the water-cooled module is started to pass cooling water into the runner of the water-cooled module after the casting mold is filled with aluminum broth, and then the loading is performed The squeezing of the mold, after the casting is taken out, air is introduced to completely discharge the hot water.

The mobile carrier uses an aluminum alloy cast-forged rim forming method, wherein when the aluminum soup is injected into the lower mold, the position of the upper mold can be in a fully open or semi-closed state.

The mobile carrier uses an aluminum alloy cast-forged rim forming method, wherein the cast-forged rim can obtain mechanical properties with yield strength of 221MPA, tensile strength of 276MPA, and elongation of more than 7%.

The mobile carrier uses an aluminum alloy cast-forged wheel rim forming method, wherein the upper die master cylinder pressure only needs to apply a pressure of less than 20 tons to squeeze the aluminum broth.

The mobile carrier uses an aluminum alloy cast-forged rim forming method, wherein the aluminum-containing material is a precipitation hardening aluminum alloy for forging.

The forming mold for the aluminum alloy cast-forged wheel rim for the mobile carrier includes: a lower mold corresponding to the lower half of a casting blank with a cavity; an upper mold corresponding to the upper half of the casting blank There is a mold cavity; a riser tube is connected to the center of the bottom of the lower mold; and a water-cooled module is adjacent to the vicinity of the outlet of the riser tube; the aluminum is melted by inert gas Press it into the lower mold steadily, and then start the water-cooling module to locally cool the aluminum soup to form a specific solid-liquid ratio state. Then, move the upper mold to press the lower mold to cool and release, and finally form the The first embryo.

Through the above technical means, the present invention can achieve the following effects:

1. The method of the present invention is to inject and fill the aluminum broth under the casting mold, and then supplement the aluminum broth to be pressed down by the upper mold, so that the method of the present invention can adopt the precipitation hardening aluminum alloy for forging, American Aluminum Composition Standard AA 2XXX, 6XXX , 7XXX and other materials to pre-cast the first embryo, without poor fluidity, and improve the serious segregation of the traditional casting method; then, the parts of the cast-forged rim that are not easy to cast are used for forging. Molding is used to strengthen the mechanical properties of the cast-forged rim of the present invention. In other words, the mechanical properties obtained by the cast-forged rim of the present invention are equivalent to forged parts.

2. The construction method of the present invention uses the first preform for forging, which can make material distribution more free, and at the same time reduce the limitation of traditional forging material distribution, it can also save material waste that is unavoidable in the original traditional forging, thereby increasing the material yield.

3. The method of the present invention is to automatically apply inert gas under the mold to smoothly press the aluminum soup into the mold at a pressure of 1 to 2 atmospheres, which can avoid a large amount of entrapment when the soup is poured into the mold cavity with a robot. Oxidation phenomenon avoids the formation of oxide film on cast and forged rims and improves its quality; in addition, the plastic working after the first preliminary embryo is all hot forming at the recrystallization temperature, so as to improve the formability and Manufacturing yield.

A: Casting and forging forming method

a, b, c, c1, c2, d, e: steps

1: Mold

11: Lower mold

111: Mould Cavity

12: Upper mold

121: Mould Cavity

2: riser pipe

21: Exit

3: Water cooling module

4: Aluminum soup

41: solid area

42: Liquid or semi-solid area

5: The first embryo

51: riser nozzle

6: The second embryo

7: Cast and forged wheels

70: body

71: plate

72: spokes

73: Center hole

74: Screw hole

75: tire ring

8: Forging die

Figure 1: A flow chart of the forming method of aluminum alloy cast-forged wheels for mobile carriers of the present invention.

Figure 2: A preferred flow chart of the method of forming aluminum alloy cast-forged wheels for mobile carriers of the present invention.

Figure 3: A schematic diagram of the fully opened state of the casting mold of the present invention.

Figure 4: A schematic diagram of the half-open and half-closed state of the casting mold of the present invention.

Figure 5: Schematic diagram of the casting blank forming in the casting mold of the present invention.

Figure 6: Schematic diagram of demolding of the casting mold of the present invention.

Figure 7: Schematic diagram of plastic working by hot work in the present invention.

Fig. 8: A schematic cross-sectional view of a cast-forged rim manufactured by the method of the present invention.

Figure 9: A front view of a cast-forged rim manufactured by the method of the present invention.

The present invention relates to a method for forming aluminum alloy cast and forged rims for mobile vehicles. It mainly provides manufacturing and production of general vehicle rims, hubs, and hub motor housings that can be expanded to electric vehicles, etc., with unilateral disk surfaces and ring-shaped side walls. Cylindrical cast-forged wheels. In other words, the cast and forged wheels of the present invention are not limited to vehicles, and can be expanded to other light metal cast and forged parts for mobile vehicles.

As shown in Figures 8 and 9, according to the planning of the casting and forging method of the present invention, a casting The body 70, disc surface 71, spokes 72, center hole 73, tire ring 75 and other parts of the rim 7 are first cast into a cast blank, and then the body 70, disc surface 71, spokes 72, center hole 73, and tire ring 75 Hot forging operation. In addition to the precision forging disc surface 71, the hot forging operation is more specifically to extend the tire ring 75 to a longer length by spinning, and then perform punching and cutting off part of the remaining material. Finally, the cast and forged wheel The ring is heat treated.

Therefore, as shown in Figure 1, the casting and forging method A of the present invention includes: a raw material melting step (a), a casting step (b), a plastic forming step (c), and a punching and trimming step (d), a heat treatment step (e). Hereinafter, each step of the casting and forging method A of the present invention is described in detail as follows:

A raw material melting step (a) is to melt an aluminum-containing material into an aluminum soup 4, and put the aluminum soup 4 in a container for standby; and the aluminum-containing material can be a precipitation hardening aluminum alloy for forging. The composition standard AA 2XXX, 6XXX, 7XXX and other materials allow the cast and forged wheels manufactured by the method of the present invention to obtain mechanical properties close to forged parts.

A casting step (b) is to use a riser tube 2 located in the lower mold 11 of a casting mold 1, and the riser tube 2 will be connected to the standby container of the aluminum soup 4, through the riser tube 2 The aluminum broth 4 is sucked to inject the aluminum broth 4 into the lower mold 11.

Next, a water-cooled module 3 is provided next to the outlet 21 of the riser tube 2, and the flow channel of the water-cooled module 3 is set to surround the outlet 21 of the riser tube 2. The module 3 must be activated before an upper mold 12 provided in the casting mold 1 squeezes the aluminum soup 4 in the lower mold 11. The stroke position of the upper mold 12 refers to the continuous operation of the fully open or semi-closed state as shown in FIGS. 3 and 4.

When the water-cooling module 3 is to be started, the aluminum soup 4 in the mold 1 can be cooled gradually from near to far, thereby obtaining a solid region 41 and a liquid or semi-solid region 42 with a specific solid-liquid ratio. In other words, as shown in Figure 4, the so-called gradual cooling effect is mainly due to the output of the riser pipe 2. The aluminum soup 4 near the outlet 21 of the riser tube 2 at the mouth 21 is more likely to solidify into a solid state, but the outlet 21 will not be completely sealed. At this time, an upper mold 12 provided in the casting mold 1 squeezes the aluminum soup 4 in the lower mold 11, and the solid region 41 can prevent the aluminum soup 4 from flowing back and blocking the riser tube 2, so as to benefit again. The mold 1 is cooled and demolded as a whole. The so-called demolding refers to separating the lower mold 11 and the upper mold 12, and the side cylinders connected to the lower mold 11 to open the mold from all directions, and then obtain Figure 5 and Fig. 6 is a first preform 5, wherein the first preform 5 has the prototype of the body 70 of the cast-forged rim, the disc surface 71, the spokes 72, the center hole 73, and the tire ring 75.

A plastic forming process step (c) is to heat and finish forging the first preform 5 at a temperature above the recrystallization temperature, especially the body 70, disc surface 71, spokes 72, and center of the cast-forged rim The hole 73 and the tire ring 75 are precision forged with a forging die 8, as shown in FIG. 7, to obtain a second preform with a finer structure. In other words, as shown in Fig. 2, the plastic forming process further includes a disk surface hot fine forging and shaping step (c1) and a hot spinning elongation step (c2), wherein the disk surface hot fine forging and shaping step ( c1) Precision forging is performed on the concave prototype of the main body 70, disc surface 71, spokes 72, center hole 73, and screw hole 74 of the cast-forged rim, and the hot spinning extension step (c2) is extended by hot spinning Take out the bead ring 75 of the cast-forged rim to the required length (width).

A punching and trimming step (d) is a punching and trimming process to remove excess material from a specific part of the second preform, for example: the window between the ribs of the cast and forged rim and Surround the remaining material in the circumference of the disk.

A heat treatment step (e) is to obtain a cast and forged rim 7 after solid solution and aging treatment of the second preliminary embryo. The so-called solid solution heat treatment is to raise the temperature of the workpiece to the solid solution temperature so that the alloy elements in the material are solidly diffused and uniformly distributed inside the material, and then quenched water is rapidly cooled to fix the distribution of the elements at the solid solution temperature. Down, and the so-called aging treatment (Aging treatment), after the solid solution, the material becomes a supersaturated solid solution, which is not stable, and the second phase will precipitate over time. The precipitation of the second phase in the material base can strengthen the mechanical properties and hardness of the material due to solid solution and aging treatment It is a common technology in the industry and will not be repeated here. The cast-forged rim 7 subjected to the heat treatment step (e) can obtain mechanical properties close to forged parts such as yield strength of 221 MPA, tensile strength of 276 MPA, and elongation of 7% or more.

The above steps constitute an aluminum alloy cast-forged rim molding method of the present invention for a mobile carrier. The most important method is to inject and fill the aluminum soup 4 into the lower mold 11 with a riser 2 under the mold 1 and then supplement it with The upper mold 12 presses down the aluminum soup 4, so that the method of the present invention can be used for forging precipitation hardening aluminum alloy and other materials to pre-cast the first preliminary embryo 5 without having poor fluidity and in the mold cavity Problems such as incomplete filling and severe segregation have also been improved.

In addition, the water-cooled module 3 is provided at the outlet of the riser pipe 2. The water-cooled module 3 is provided with a separate mechanism on the lower mold 11, and is equipped with a circulating water channel. During the aluminum soup process, the water cooling module 3 is not activated, so there is no cooling water in the flow channel. When the aluminum soup 4 is filled and needs to be cooled, the cold water is introduced and the hot water is discharged After cooling, after taking out the first preform 5, air must be blown in to completely discharge the hot water.

During the filling process of the casting mold 1, the pressure of the riser 2 is at least 1 to 2 atmospheres of inert gas (Inert gas), so that the aluminum soup 4 can be transported upward to the lower mold 11, and the filling process of the casting mold 1 is approximately 8 seconds to 15 seconds, and the pressing time of the upper mold 12 is about 3-10 seconds, and the pressing aluminum soup stroke of the upper mold 12 is about 20-100 mm, and the total output of the hydraulic cylinder of the upper mold 12 is less than 20 The power of tons is far lower than the output of hundreds to thousands of tons of forging machines.

The disc surface 71 of the cast-forged rim of the present invention forms a little burr during the casting process. The burr corresponds to the forging flash position. After forging, the flash can be directly discharged to avoid the forging from being clamped into the forging after forging; The primary embryo 5 corresponds to the riser tube 2 to form a riser nozzle 51. If the riser nozzle 51 is not removed before forging, the forging die 8 can reserve space to accommodate this feature for forging. This feature can be removed by mechanical processing; however, the tire ring 75 must be ground if necessary, and then placed in the forging die 8.

The cast and forged rim completed by the method of the present invention is then processed and controlled in precision dimensions by machining methods such as turning, milling or drilling to obtain a machined part that meets customer requirements for structural strength and mechanical properties. Finally, according to customer needs Surface treatment is the final product.

Regarding the forming mold 1 of the aluminum alloy cast-forged rim for the mobile carrier of the present invention, as shown in FIGS. 3 to 5, it includes: a lower mold 11 corresponding to the lower half of a casting blank 5. Mold cavity 111; an upper mold 12, corresponding to the upper half of the casting blank with a mold cavity 121; a riser tube 2 connected to the center of the bottom of the lower mold 11; and a water cooling module 3 , Is close to the vicinity of the exit 21 of the riser tube 2; the aluminum soup 4 is smoothly pressed into the lower mold 11 with an inert gas, and then the water-cooled module 3 is started to locally cool the aluminum soup 4 to form In a specific solid-liquid ratio state, the upper mold 12 is moved and pressed to the lower mold 11 and then cooled and demolded, and finally the casting embryo is formed, that is, the first preliminary embryo 5 is obtained.

In summary, the present invention relates to a "formation method of aluminum alloy cast-forged rims for mobile carriers and its casting molds", and the construction steps and methods have not been seen in books or publicly used, and sincerely meet the requirements of a patent application. The Office has clearly appraised that the patent is granted, and I’m very grateful; for those who need to be clarified, the above are the specific embodiments of the patent application and the technical principles used. If changes are made according to the concept of the patent application, the If the resulting functional effect does not exceed the spirit covered by the specification and drawings, it shall be stated within the scope of this patent application.

A: Forming method

a, b, c, d, e: steps

Claims (10)

A method for forming aluminum alloy cast-forged rims for mobile carriers includes: a raw material melting step, which is to melt an aluminum-containing material into an aluminum broth; and a casting step, which is located in a lower mold of a casting mold. The riser tube is used to inject the aluminum broth into the lower mold through the riser tube, and a water-cooling module is arranged near the exit of the riser tube. The cooling effect is gradually reduced, so that the aluminum broth forms a solid area and a liquid or semi-solid area. At this time, an upper mold set in the casting mold is used to squeeze the aluminum broth to prevent the aluminum broth from refluxing and blocking The riser tube is finally cooled and demolded to obtain a first primary embryo of the entire casting mold; a plastic forming processing step is to perform precision forging and spinning of the first primary embryo at a temperature above the recrystallization temperature Press forming operation to obtain a second preform; and a heat treatment step, after solid solution and aging treatment of the second preform, to obtain a cast and forged rim. The aluminum alloy cast-forged rim molding method for mobile carriers described in claim 1, wherein the riser tube injects the aluminum broth into the lower mold by using an inert gas at a pressure of 1 to 2 atmospheres. The soup is smoothly pressed into the lower mold. The aluminum alloy cast-forged rim forming method for a mobile carrier according to claim 1, wherein the plastic forming process is performed by hot forming above the recrystallization temperature, which includes a disk surface hot forming fine forging and shaping step and A hot spinning extension step; where the purpose of fine forging and shaping is to make the ribs and each detailed feature closer to the final product; after plastic forming, the inside of the cast blank material also obtains a more refined and compact microstructure, and the hot spinning The purpose of the pressing and stretching step is to stretch the bead ring to form a thin-walled feature. According to claim 1, the aluminum alloy cast-forged rim forming method for mobile carriers, wherein a punching and trimming step is further included between the plastic forming processing step and the heat treatment step, wherein the punching and trimming processing step is By means of a punching die, the remaining material is removed from the specific parts of the second preliminary embryo, such as the intercostal window and the forging flash of the disk surface. According to claim 1, the aluminum alloy cast-forged rim molding method for a mobile carrier, wherein the flow channel of the water-cooled module is set to surround the outlet of the riser pipe and is embedded in the lower mold. As described in claim 5, the aluminum alloy cast-forged rim molding method for mobile carriers, wherein the water-cooled module is started to pass cooling water into the runner of the water-cooled module after the casting mold is filled with aluminum broth, and then Then, the upper mold is pressed, and after the casting is taken out, air is introduced, and then the cooling water is completely discharged. According to claim 1, the aluminum alloy cast-forged rim molding method for mobile carriers, wherein when the aluminum broth is injected into the lower mold, the stroke position of the upper mold can be a fully open or semi-closed state. The aluminum alloy cast-forged rim forming method for mobile carriers as described in claim 1, wherein the upper mold applies an squeezing force to the aluminum soup, and the total pressure of the master cylinder before the mold is completely closed is set to be less than 20 Tons of power. The method for forming aluminum alloy cast-forged rims for mobile vehicles according to any one of claims 1 to 8, wherein the aluminum-containing material is a precipitation hardening aluminum alloy for forging, that is, AA 2xxx, 6xxx or 7xxx series The precipitation hardening aluminum alloy for forging allows the cast and forged rim to obtain mechanical properties with yield strength of 221MPA, tensile strength of 276MPA, and elongation of 7% or more. A molding mold for aluminum alloy cast-forged wheels for mobile vehicles, which includes: a lower mold corresponding to the lower half of a casting blank with a cavity; an upper mold corresponding to the upper half of the casting blank. There is a mold cavity; a riser pipe connected at the center of the bottom of the lower mold; and a water-cooled module set next to the outlet of the riser pipe; the aluminum soup is stabilized by the inert gas Press the ground into the lower mold, and then start the water-cooling module to locally cool the aluminum soup to form a solid area and a liquid or semi-solid area, and then move the upper mold to press the lower mold to cool and release, and finally The cast embryo is formed.

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