Integrated production and manufacturing method and device for die castings

Abstract

The invention discloses a die casting integrated production and manufacturing method and device. The method comprises the steps that a die casting is divided into a plurality of areas according to a preset rule, each area is independently produced through low-pressure casting equipment, the multiple low-pressure casting equipment synchronously operates for production, and a middleware is formed at a time; and defects on the middleware are trimmed through a material reducing machining method, and the die casting is obtained. The device comprises a plurality of low-pressure casting devices corresponding to a plurality of areas divided by a die casting according to a preset rule, and a liquid supply pipe, wherein a plurality of branch pipes connected with the low-pressure casting devices are arranged on the liquid supply pipe; each low-pressure casting device comprises a lower die assembly and an upper die assembly which are oppositely arranged, and the problems that an ultra-large die casting machine is high in manufacturing cost, long in manufacturing period, high in maintenance cost, long in maintenance time and high in production efficiency can be solved. The problems that an integrated die-casting process is blocked, die cost is high, die maintenance is difficult, die maintenance cost is high, die service life is short, heat-treatment-free aluminum alloy materials do not exist, and the yield is low are solved.

Description

Technical Field

[0001] The invention relates to the production of large or super-large thin-wall parts, and in particular to an integrated production method and device for die castings. Background Art

[0002] Integrated die-casting is a new manufacturing technology that converts multiple complex structural parts on the body of white into one part produced at one time using the die-casting process. It is currently mainly used to produce body of white structural parts and cover parts such as the front cabin and rear floor of the lower body. Compared with the original "stamping + welding" process production model, it performs well in five aspects: production cost, production efficiency, car manufacturing accuracy, safety performance, and lightweight effect.

[0003] Integrated die casting uses a super-large die-casting machine to hydraulically press heat-free aluminum alloy into a super-large mold. The aluminum alloy liquid is cooled and solidified in the super-large mold to form an integrated die-casting component production technology. Its main problems are as follows: 1) Equipment: Super-large die-casting machines generally refer to die-casting machines with a tonnage of ≥6,500 tons. Currently, there are only a few die-casting machine manufacturers that have mastered this type of heavy-duty die-casting machines, such as Lijin and Yizumi in China and Buhler abroad. The price of a single device is ≥35 million, the manufacturing cycle is as long as ≥1 year, and the subsequent maintenance cost is high and the maintenance time is long.

[0004] 2) Process and mold: The structure of integrated die-casting parts is very complex, which puts forward higher requirements for die-casting process technology and mold design. At present, relatively mature integrated die-casting process technology is mastered by a few mold companies such as Guangzhou Cavity, Ningbo Zhenzhi, and Ningbo Savida. The weight of a single mold is very heavy (≥130 tons), and the manufacturing cost of each mold is high (≥15 million). Subsequent mold maintenance scheduling and transportation are difficult, the maintenance cost is high, the maintenance time is long, and the mold life is short (≤80,000 molds, compared with the mold life of low-pressure casting molds ≥200,000 molds).

[0005] 3) Aluminum alloy materials: Traditional aluminum alloy die-castings need to undergo solid solution and aging heat treatment to meet the strength, durability, and impact resistance required for vehicle body performance. During the heat treatment process, die-castings are prone to dimensional deformation and surface defects. Because integrated die-casting parts are generally large-sized thin-walled parts, their deformation will be more obvious during the heat treatment process, and they will be more likely to have quality problems such as surface blistering, so integrated die-casting cannot use heat treatment processes. At present, integrated die-casting manufacturers solve the deformation problem by developing heat-treatment-free aluminum alloy materials, but due to the limitations of the basic performance of the materials themselves or the different development levels, only Tesla and Lizhong Group have relatively mature heat-treated aluminum alloy materials on the market. In the actual production process, the product yield rate is only 30% to 70%, which seriously fails to meet the product quality requirements of automobile companies and increases product manufacturing costs.

[0006] CN218015684U discloses a multi-shot system vertical die-casting machine for preparing large integrated die-casting parts. The casting liquid is injected simultaneously from multiple directions, so that the casting liquid can quickly fill the space between the movable mold and the fixed mold in a short time. The casting liquid flows in the mold for a short distance and a short time, thereby avoiding the coexistence of solid and liquid in the casting liquid and the occurrence of cold shut or air holes at the end of the mold casting. The theoretical basis of this scheme is to increase the number of shot systems and cast in multiple directions at the same time. The equipment, mold and process of integrated die casting are still used, and the related problems of integrated die casting technology cannot be solved.

[0007] CN115446286A discloses an integrated vehicle floor die-casting mold device and method, which only sets the cavity vertically, but still uses a large die-casting machine and a mold to produce the integrated vehicle floor. The technology itself is still limited by the size of the die-casting machine and the mold, and can only produce products within the size specifications of the equipment, which is consistent with the current die-casting process or integrated die-casting process. Summary of the invention

[0008] The purpose of the present invention is to provide an integrated production method and device for die-casting parts, which can solve the problems of high manufacturing cost, long manufacturing cycle, high maintenance cost, long maintenance time of ultra-large die-casting machines, blocked integrated die-casting process, high mold cost, difficult mold maintenance, high mold maintenance cost, short mold life, lack of heat-treatment-free aluminum alloy materials, and low yield rate.

[0009] In order to achieve the above object, the technical solution adopted by the present invention is as follows: In the first aspect, the present invention provides an integrated production and manufacturing method for die-castings, the method comprising: dividing the die-casting into several areas according to preset rules, each area is produced separately using low-pressure casting equipment, the low-pressure casting equipment in several areas are operated and produced synchronously to form an intermediate piece at one time; and using a subtractive processing method to trim defects on the intermediate piece to obtain a die-casting.

[0010] Furthermore, the preset rule is specifically: the die casting is divided into several areas according to the size of the low-pressure casting equipment, the processing capacity of the low-pressure casting equipment or the shape characteristics of the product.

[0011] Furthermore, the low-pressure casting equipment corresponding to each area is provided with independent cooling, exhaust systems and processing parameters.

[0012] In the second aspect, the present invention provides an integrated production and manufacturing device for die-castings, which includes a plurality of low-pressure casting devices and a liquid supply pipe corresponding to a plurality of areas divided according to preset rules of the die-castings, the liquid supply pipe being provided with a plurality of branch pipes connected to the low-pressure casting devices; a single low-pressure casting device includes a lower mold assembly and an upper mold assembly arranged relatively, the lower mold assembly includes a lower mold frame and a fixed mold fixed on the lower mold frame, the upper mold assembly includes an upper mold frame and a movable mold connected to the upper mold frame and capable of moving up and down, the branch pipe of the liquid supply pipe is connected to the upper mold frame, and the molten metal in the liquid supply pipe enters into the cavity formed by the movable mold and the fixed mold through the upper mold frame.

[0013] Furthermore, a valve body is connected to the branch pipe, and the valve body is connected to a host computer. The opening and closing of the valve body is controlled by the host computer to realize the connection or disconnection of the branch pipe.

[0014] Furthermore, the liquid supply pipe is connected to a positive pressure or negative pressure generating component, and the flow of the molten metal in the liquid supply pipe is accelerated by the positive pressure or negative pressure.

[0015] Beneficial effects of the present invention: 1. The present invention divides the die castings into several areas according to preset rules, and each area is produced by a low-pressure casting device alone. The low-pressure casting devices in several areas are operated and produced synchronously. Since each low-pressure casting device is only responsible for the molding and quality of the parts in this area, an independent cooling, exhaust system and process parameters can be set on the low-pressure casting device, so that the temperature field of the mold in the low-pressure casting device can be effectively guaranteed, solving the problems of large-scale integrated die casting equipment and mold cooling, exhaust, and rapid changes in temperature field, and effectively improving product quality. The number of low-pressure casting equipment required for the integrated production and manufacturing method of die castings is expanded according to the division of preset rules. In theory, there is no upper limit on the low-pressure casting equipment, and integrated parts of any size can be produced. And the defects on the intermediate parts are subsequently trimmed by the subtractive processing method to obtain the die castings, which ensures the product quality.

[0016] 2. The manufacturing cost of the low-pressure casting equipment in several areas described in the present invention is ≤ 600,000, so the manufacturing cost of the partitioned low-pressure casting equipment is much lower than the existing super-large die-casting machine and its mold cost; the manufacturing cycle of a single partitioned low-pressure casting equipment is about 6 months, so the manufacturing cycle of the partitioned low-pressure casting equipment is much lower than the manufacturing cycle of the super-large die-casting machine and its mold; the overall structure of the partitioned low-pressure casting equipment is simpler than that of the super-large die-casting machine, so the later maintenance cost is lower and the maintenance is more convenient. And the low-pressure casting mold in the low-pressure casting equipment is used to replace the super-large mold of integrated die-casting, and the manufacturing cost of a single low-pressure casting mold is ≤ 50,000, and the mold manufacturing cost is much lower than the super-large mold of integrated die-casting; the manufacturing cycle of a single low-pressure casting mold is about 20 days, and the manufacturing cycle is much lower than the super-large mold of integrated die-casting; the overall structure of the low-pressure casting mold is simpler than the super-large mold of integrated die-casting, and the mold is lighter, so the later maintenance cost is lower and the maintenance is more convenient; the life of the casting mold is generally ≥ 200,000 times, which is much higher than the life of the integrated die-casting mold, and it is more cost-saving.

[0017] 3. Conventional low-pressure casting processes all use a holding furnace to temporarily store molten metal, and transport the molten metal to the mold cavity through a riser pipe. The present invention optimizes the aluminum supply system, and uses an aerial pipeline-type liquid supply pipe to replace the traditional holding furnace-type molten metal aluminum supply system, eliminates the holding furnace and riser pipe structures, and uses the internal pressure of the liquid supply pipe and the liquid stop valve to achieve the purpose of supplying molten metal to the mold cavity.

[0018] 4. Conventional low-pressure casting process molds generally use one mold to produce one or two small-sized products. Due to the limitation of the mold cavity size, large-sized parts (the size of existing integrated die-casting products) cannot be produced. The present invention divides large-sized products into zones. According to factors such as product structure, mold cavity size, and the size of the zoned low-pressure casting equipment, the large-sized products are divided into multiple small-sized areas. Multiple low-pressure casting equipment are combined together for production, thereby achieving the purpose of producing large integrated thin-walled parts.

[0019] 5. The partitioned low-pressure casting process of the present invention can continue to use conventional low-pressure casting aluminum alloy materials and heat treatment processes. The integrated die-casting process cannot use heat treatment processes due to its process characteristics, and must use heat-treatment-free aluminum alloy materials. However, there are no such mature material grades in the existing aluminum alloy market, and each car company needs to develop them on its own. The development cost is high and the actual production yield is low. The partitioned low-pressure casting process can continue to use conventional low-pressure casting aluminum alloy materials and heat treatment processes. Existing ADC12, ZL102 and other material grades can still be used, and conventional T5 or T6 heat treatment processes are used. Due to the low-pressure casting process and mature aluminum alloy grades, the yield is generally as high as 98% or more. Therefore, compared with the integrated die-casting process, the yield of large integrated thin-walled parts can be improved, reducing the cost waste caused by waste. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present invention.

[0021] Figure 1 It is a schematic diagram of the structure of a conventional four-column low-pressure casting machine; Figure 2 A schematic diagram of the regional division of a die casting according to an embodiment of the present invention; Figure 3 It is a schematic diagram of the structure of the integrated production and manufacturing device for die castings described in an embodiment of the present invention; Figure 4 is a schematic diagram of the arrangement of the liquid supply pipe in an embodiment of the present invention; Figure 5 It is a front view of the integrated production and manufacturing device for die castings described in an embodiment of the present invention; Figure 6 Schematic diagram of the control system architecture of the low-pressure casting equipment described in an embodiment of the present invention.

[0022] In the figure, 1 is a low-pressure casting equipment, 2 is a liquid supply pipe, 3 is a branch pipe, 4 is a valve body, 5 is a lower mold assembly, 51 is a lower mold frame, 52 is a fixed mold, 6 is an upper mold assembly, 61 is an upper mold frame, 62 is a movable mold, 7 is an existing upper mold frame, 8 is an existing lower mold frame, 9 is a column, and 10 is a die casting. DETAILED DESCRIPTION

[0023] The following will describe the embodiments of the present invention with reference to the accompanying drawings and preferred embodiments. Those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present invention. It should be understood that the preferred embodiments are only for illustrating the present invention, not for limiting the scope of protection of the present invention.

[0024] It should be noted that the illustrations provided in the following embodiments are only schematic illustrations of the basic concept of the present invention. The drawings only show components related to the present invention rather than being drawn according to the number, shape and size of components in actual implementation. In actual implementation, the type, quantity and proportion of each component may be changed arbitrarily, and the component layout may also be more complicated.

[0025] Embodiment 1, a method for integrated production and manufacturing of die castings, the method comprising: dividing the die castings into several areas according to preset rules, each area is produced by a low-pressure casting device alone, the low-pressure casting devices in several areas are operated and produced synchronously, and the intermediate parts are formed at one time; the defects on the intermediate parts are trimmed by a subtractive processing method to obtain the die castings. Because each low-pressure casting device is only responsible for the forming and quality of the parts in this area, an independent cooling, exhaust system and process parameters can be set on the low-pressure casting device, so that the temperature field of the mold in the low-pressure casting device can be effectively guaranteed, and the problems of large-scale integrated die casting equipment and mold cooling, exhaust, and rapid temperature field changes are solved, and the product quality is effectively improved. The number of low-pressure casting devices required for the integrated production and manufacturing method of die castings is expanded according to the division of preset rules. In theory, there is no upper limit on the low-pressure casting equipment, and integrated parts of any size can be produced. And the defects on the intermediate parts are trimmed by a subtractive processing method in the subsequent process to obtain die castings, which ensures product quality.

[0026] In this embodiment, the preset rule is specifically: dividing the die casting into several areas according to the size of the low-pressure casting equipment, the processing capacity of the low-pressure casting equipment or the shape characteristics of the product.

[0027] Example 2, see Figure 3 As shown, an integrated production and manufacturing device for die castings includes a plurality of low-pressure casting devices 1 and a liquid supply pipe 2 corresponding to a plurality of areas divided according to preset rules of the die castings, and the liquid supply pipe 2 is provided with a plurality of branch pipes 3 connected to the low-pressure casting devices 1; a single low-pressure casting device 1 includes a relatively arranged lower mold assembly 5 and an upper mold assembly 6, the lower mold assembly 5 includes a lower mold frame 51 and a fixed mold 52 fixed on the lower mold frame 51, the upper mold assembly 6 includes an upper mold frame 61 and a movable mold 62 connected to the upper mold frame 61 and capable of moving up and down, the branch pipe 3 of the liquid supply pipe 2 is connected to the upper mold frame 61, and the molten metal in the liquid supply pipe 2 enters into the cavity formed by the movable mold 62 and the fixed mold 52 through the upper mold frame 61.

[0028] In this embodiment, the branch pipe 3 is connected to a valve body 4 , and the valve body 4 is connected to a host computer. The host computer controls the opening and closing of the valve body 4 to realize the connection or disconnection of the branch pipe 3 .

[0029] In this embodiment, the liquid supply pipe 2 is connected to a positive pressure or negative pressure generating component, which accelerates the flow of molten metal in the liquid supply pipe through the positive pressure or negative pressure, thereby increasing the metal filling speed and manufacturing cycle. The arrangement of the liquid supply pipe 2 and the branch pipe 3 can be matched according to the number of partitioned low-pressure casting equipment 1 to meet the production liquid supply requirements.

[0030] Take the manufacture of a certain integrated die casting 10 as an example. Its length × width × height is: 1447mm × 1574mm × 600mm, thickness is 3mm to 6mm, and weight is about 50kg. The original technical solution uses 8500T large die casting machine and 130T mold for integrated die casting, with a yield rate of 73%. Figure 1 As shown, the hardware of a conventional four-column low-pressure casting machine is generally divided into an existing upper mold frame 7 and an existing lower mold frame 8. The existing upper and lower mold frames are supported and connected by four columns 9, and the weight of the whole is supported by the ground. The aluminum liquid enters the mold through the existing lower mold frame 8. The existing lower mold frame 8 is connected to the fixed mold, and the existing upper mold frame 7 is connected to the movable mold.

[0031] The specific implementation is described in conjunction with the accompanying drawings. Figure 2 As shown, the die casting is divided into four areas A, B, C, and D according to a preset rule, and each area is produced using a low-pressure casting device 1. Figures 3 to 5 As shown, the lower mold frame 51 of the low-pressure casting equipment 1 is fixed to the ground by bolt connection, and the fixed mold 52 is fixed to the top of the lower mold frame 51 by bolts and limit pins. Compared with the conventional low-pressure casting machine, the lower mold frame 51 only bears the weight of the fixed mold 52, and has lower requirements on its mechanical properties, which is convenient for manufacturing.

[0032] When preparing for production, refer to Figure 6 As shown, the process parameters of the low-pressure casting equipment 1 corresponding to each area are set on the upper computer PLC of the control system, and the low-pressure casting equipment 1 is in the mold opening state. After the upper computer PLC sends a production signal to each low-pressure casting equipment PLC, the movable mold starts to move until the mold is closed to form a cavity. The mold closing time and sequence are determined according to the previous process design. After the mold is closed, the upper computer PLC sends a supply pipeline opening signal, the valve body 4 opens the supply pipeline opening, and the aluminum liquid in the liquid supply pipe 2 is injected into the cavity of the low-pressure casting equipment through the branch pipe 3 to fill the mold.

[0033] After the filling is completed and the host computer PLC closes the signal, the valve body 4 closes the supply pipeline port, and the four low-pressure casting equipment 1 continue to pressurize and keep warm according to the process parameter requirements until the pressure is released.

[0034] After the pressure relief is completed, the low-pressure casting equipment 1 starts to lift the parting mold, and at the same time, the integrated die casting 10 is ejected. After each movable mold is opened, the die casting 10 can be taken away by manual labor, manipulators or robots. The production of the die casting 10 is completed and enters the next round of production cycle. The entire production process is coordinated by the host computer.

[0035] The above embodiments are only preferred embodiments for fully illustrating the present invention, and the protection scope of the present invention is not limited thereto. Any equivalent substitution or change made by a person skilled in the art based on the present invention is within the protection scope of the present invention.

Claims

1. A die casting integrated production method, characterized in that: include: Die castings are divided into several areas according to preset rules. Each area is produced by a low-pressure casting device. The low-pressure casting devices in several areas are operated and produced synchronously to form intermediate parts at one time. The defects on the intermediate piece are trimmed by subtractive machining to obtain the die casting.

2. The integrated die casting manufacturing method according to claim 1, characterized in that: The preset rule is specifically: the die casting is divided into several areas according to the size of the low-pressure casting equipment, the processing capacity of the low-pressure casting equipment or the shape characteristics of the product.

3. The integrated die casting manufacturing method according to claim 1, characterized in that: The low-pressure casting equipment corresponding to each area is equipped with independent cooling, exhaust systems and processing parameters.

4. An integrated die casting manufacturing device, characterized in that: It includes a plurality of low-pressure casting devices and a liquid supply pipe corresponding to a plurality of areas divided according to preset rules of the die casting, wherein the liquid supply pipe is provided with a plurality of branch pipes connected with the low-pressure casting devices; A single low-pressure casting device includes a lower mold assembly and an upper mold assembly arranged relatively to each other, wherein the lower mold assembly includes a lower mold frame and a fixed mold fixed on the lower mold frame, and the upper mold assembly includes an upper mold frame and a movable mold connected to the upper mold frame and capable of moving up and down, and the branch pipe of the liquid supply pipe is connected to the upper mold frame, and the molten metal in the liquid supply pipe enters into the mold cavity formed by the movable mold and the fixed mold through the upper mold frame.

5. The die casting integrated manufacturing device according to claim 4, characterized in that: The branch pipe is connected with a valve body, and the valve body is connected to a host computer. The opening and closing of the valve body is controlled by the host computer to realize the conduction or disconnection of the branch pipe.

6. The die casting integrated manufacturing device according to claim 4, characterized in that: The liquid supply pipe is connected to a positive pressure or negative pressure generating component, and the flow of the metal liquid in the liquid supply pipe is accelerated by the positive pressure or negative pressure.

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