Integrated subframe forming device and forming method

Abstract

The application discloses a kind of integrated subframe forming device and forming method, device includes electric furnace, refining furnace, electromagnetic drive pump, centrifugal device, vacuum pump;Centrifugal device includes motor, rotating seat, multiple quick-change casting mold;The application is realized by adopting multiple quick-change casting mold cyclic operation continuous manufacturing of continuous integrated subframe, saves the time of mould cooling, mold opening, stripping, improves production efficiency;Through the cooperation of low pressure and counter gravity, the rapid forming of integrated subframe is realized, compared with pressure casting, the casting can reach the highest performance of aluminum alloy through heat treatment, and the casting efficiency is improved by 50% compared with low pressure casting;Through the cooperation of the casting barrel provided with air extraction connecting port and the rotating seat provided with connecting pipe, and through the cooperation of the quick-change casting mold provided with quick-change connecting structure and the rotating seat, synchronous quick connection of air extraction and rotation can be realized when the quick-change casting mold is installed on the rotating seat.

Description

Technical Field

[0001] This invention relates to the field of vehicle frame manufacturing technology, and in particular to an integrated subframe forming apparatus and forming method. Background Technology

[0002] The automotive subframe is a crucial structural safety component, connecting and securing the suspension system, steering system, engine, and other assembly parts. It demands high performance in terms of strength, rigidity, modal characteristics, and handling stability. To reduce subframe weight and achieve vehicle lightweighting, domestic and international OEMs have been researching and some have already successfully implemented various aluminum alloy subframes using different forming processes. Current forming processes used in the production of automotive aluminum alloy parts include die casting, extrusion forming, forging, aluminum tube hydroforming, aluminum sheet stamping, and welded composite forming.

[0003] The integrated hollow subframe is far superior to previous split-manufactured parts in terms of lightweighting, strength, manufacturing cost, and production efficiency, and will therefore become the ultimate choice for new energy vehicles.

[0004] Due to the complex and hollow structure of the integrated hollow casting subframe, and in addition to the easy oxidation and gas absorption of aluminum alloy, the subframe itself is characterized by large, complex structural dimensions and uneven wall thickness. Unstable mold filling leads to defects such as cracks and shrinkage porosity in the casting, affecting performance. Therefore, ordinary gravity casting cannot meet the technical requirements, and low-pressure casting is the commonly used casting process for hollow-shaped subframes. Given that the yield and production efficiency of low-pressure casting restrict the delivery time of subframes, there is an urgent need to develop a new integrated hollow subframe casting technology with higher yield and production efficiency.

[0005] Furthermore, based on the structural characteristics of the hollow integrated subframe, low-pressure casting using sand core placement has been commercially applied. However, this technology has a slow filling speed; for example, casting a 26kg subframe takes approximately 7 minutes, and mold preparation and sand core placement are both performed on the machine, resulting in low single-machine casting efficiency. For large castings like subframes, the slow filling speed increases the risk of casting defects such as porosity and pinholes in sand castings, while metal molds require complex water cooling systems, increasing operational complexity and investment costs.

[0006] Therefore, an integrated subframe forming device and forming method were developed to solve the above problems. Summary of the Invention

[0007] The purpose of this invention is to design an integrated subframe forming device and forming method to solve the above problems.

[0008] The present invention achieves the above objectives through the following technical solutions:

[0009] The integrated subframe forming device includes:

[0010] Electric furnaces used for smelting metals;

[0011] Refining furnace; Metal that has been smelted in an electric furnace is fed into a refining furnace for refining, modification, and degassing.

[0012] Centrifuge apparatus; the centrifuge apparatus includes:

[0013] Electric motor;

[0014] Rotary base; the motor's rotating shaft is connected to the lower end of the rotary base;

[0015] Multiple quick-change molds; the lower end of the quick-change mold is installed inside the rotating seat through a quick-change connection structure, and the metal refined in the refining furnace is injected into the quick-change mold.

[0016] Furthermore, the integrated subframe forming device also includes a vacuum pump, and a connecting pipe is provided inside the rotating seat. The vacuum pump is connected to the first end of the connecting pipe through a rotary joint. The bottom of the quick-change mold is provided with a connection port that communicates with the interior. When the quick-change mold is installed inside the rotating seat, the connection port is connected to the second end of the connecting pipe.

[0017] Specifically, the quick-change mold includes a casting barrel, an inner cylinder, and a sealing device. The inner cylinder is placed inside the casting barrel, the casting is installed inside the inner cylinder, the sealing device is placed on top of the casting barrel, an air extraction channel interlayer is provided between the casting barrel and the inner cylinder, the upper end of the connection port is connected to the air extraction channel interlayer, and multiple air vents are provided on the inner cylinder wall.

[0018] Furthermore, a fixing frame is provided inside the inner cylinder, and the mold is installed on the fixing frame.

[0019] Furthermore, the bottom of the casting barrel is provided with a downwardly protruding quick-change connection structure, with the connection port vertically penetrating through the quick-change connection structure. The side wall of the quick-change connection structure is partially formed into an annular conical surface. Correspondingly, the upper inner side of the rotating seat is also formed into an annular conical surface. The annular conical surface of the quick-change connection structure is connected and fitted with the annular conical surface of the rotating seat.

[0020] Specifically, the sealing device includes a sealing strip, a locking plate, a sealing cover, and at least two wedge locking mechanisms. The locking plate is formed in a ring shape, and the lower end of the locking plate is fixed to the upper end of the casting barrel. The sealing cover is placed over the upper opening of the casting barrel. The sealing strip is placed between the upper edge of the casting barrel and the sealing cover. The edge of the sealing cover is connected to the locking plate through at least two wedge locking mechanisms.

[0021] Preferably, there are four wedge locking mechanisms, which are evenly distributed at the edge of the sealing cover.

[0022] Furthermore, a pouring hole is provided at the center of the top of the sealing cover.

[0023] Furthermore, the integrated subframe forming device also includes an electromagnetic drive pump, which is mounted on a casting pipe. The first end of the casting pipe is connected to the outlet of the refining furnace, and the second end of the casting pipe is used to insert into the casting hole of the sealing cover.

[0024] The forming method of the integrated subframe forming device includes the following steps:

[0025] S1: Place the mold into the inner cylinder and fix it with the fixing frame, then lock the top of the mold barrel with the sealing device;

[0026] S2: Insert the lower end of a quick-change mold into the rotating seat for connection, and the vacuum pump will evacuate the mold barrel;

[0027] S3: Electric furnace for smelting metal, followed by refining in a refining furnace for refining, modification, slag removal, and rotary nitrogen blowing for degassing;

[0028] S4: The mobile pouring platform inserts the second end of the pouring pipe into the pouring hole of the sealing cover, and uses an electromagnetically driven pump to quantitatively press the molten metal into the mold. During the pouring process, the motor and quick-change mold are kept rotating.

[0029] S5: After the molten metal is poured, quickly change the mold and continue rotating for a certain period of time before stopping the machine, stopping the vacuuming, and removing the pouring platform.

[0030] S6: Remove the quick-change mold to the cooling and demolding area, open the mold, and obtain the subframe casting blank;

[0031] S7: Transfer the quick-change mold with the subframe casting blank removed to the mold preparation area for the next pouring. Insert another quick-change mold that has been prepared into the rotating seat to produce the next set of subframe casting blanks.

[0032] The beneficial effects of this invention are as follows:

[0033] By adopting multiple quick-change mold cycles, continuous integrated subframe manufacturing was achieved, saving time on mold cooling, mold opening, and demolding, and improving production efficiency.

[0034] By combining low pressure and anti-gravity, the integrated subframe can be rapidly formed. Compared with pressure casting, this casting can achieve the highest performance of aluminum alloy through heat treatment, and the casting efficiency is 50% higher than that of pressure casting.

[0035] By combining the molded barrel with the air extraction port with the rotating seat with the connecting pipe, and by combining the quick-change mold with the rotating seat with the quick-change connection structure, the air extraction and rotation can be quickly and synchronously connected when the quick-change mold is installed on the rotating seat. Attached Figure Description

[0036] Figure 1 A schematic diagram of the integrated subframe forming device;

[0037] Figure 2 This is a cross-sectional view of the centrifuge device.

[0038] Figure 3 This is a cross-sectional view of the sealing device;

[0039] Figure 4 This is a top view of the sealing device;

[0040] Figure 5 This is a schematic diagram of the fixed frame structure;

[0041] In the diagram: 1. Electric furnace; 2. Refining furnace; 21. Nitrogen degasser; 3. Electromagnetic drive pump; 4. Casting pipe; 5. Centrifuge device; 51. Motor; 52. Rotating shaft; 53. Rotating seat; 54. Connecting pipe; 55. Quick-change connection structure; 56. Casting barrel; 57. Inner wall of casting barrel; 571. Inner wall evacuation hole; 58. Evacuation channel interlayer; 59. Sealing strip; 510. Locking plate; 511. Sealing cover; 512. Fixing frame; 513. Wedge locking mechanism; 6. Vacuum pump; 61. Evacuation pipe; 7. Casting mold. Detailed Implementation

[0042] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0043] Therefore, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without inventive effort are within the scope of protection of the invention.

[0044] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0045] In the description of this invention, it should be understood that the terms "upper," "lower," "inner," "outer," "left," "right," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the product of this invention is in use, or the orientation or positional relationship commonly understood by those skilled in the art. They are only used to facilitate the description of this invention and to simplify the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0046] Furthermore, the terms "first," "second," etc., are used only to distinguish descriptions and should not be interpreted as indicating or implying relative importance.

[0047] In the description of this invention, it should also be noted that, unless otherwise explicitly specified and limited, terms such as "set" and "connection" should be interpreted broadly. For example, "connection" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be a connection within two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0048] The specific embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

[0049] like Figure 1 and 2 As shown, the integrated subframe forming device includes:

[0050] Electric furnaces used for smelting metals;

[0051] Refining furnace; Metal that has been smelted in an electric furnace is fed into a refining furnace for refining, modification, and degassing.

[0052] Centrifuge apparatus; the centrifuge apparatus includes:

[0053] Electric motor;

[0054] Rotary base; the motor's rotating shaft is connected to the lower end of the rotary base;

[0055] Multiple quick-change molds; the lower end of the quick-change mold is installed inside the rotating seat through a quick-change connection structure, and the metal refined in the refining furnace is injected into the quick-change mold.

[0056] like Figure 1 and 2As shown, the integrated subframe forming device also includes a vacuum pump. A connecting pipe is installed inside the rotating base. The vacuum pump is connected to the first end of the connecting pipe via a rotary joint. The bottom of the quick-change mold has a connection port that communicates with the interior. When the quick-change mold is installed inside the rotating base, the connection port is connected to the second end of the connecting pipe. The vacuum pump is connected to the rotating base via an air extraction pipe, which is equipped with an air valve. Rapid forming is achieved through anti-gravity filling. For a single 26kg subframe, including the gating and sprue system, the filling time does not exceed 6 seconds. Due to the rapid filling, the mold can be a metal mold, a 3D printed sand mold, or a coated sand mold. The sand core is a hot-box coated sand core or a 3D printed sand core.

[0057] like Figure 2 As shown, the quick-change mold includes a mold barrel, an inner cylinder, and a sealing device. The inner cylinder is placed inside the mold barrel, and the mold is installed inside the inner cylinder. The sealing device covers the top of the mold barrel. An air extraction channel interlayer is provided between the mold barrel and the inner cylinder. The upper end of the connection port communicates with the air extraction channel interlayer. Multiple vent holes are provided on the inner cylinder wall. Compared with traditional vacuuming which only uses one connection port, this application provides multiple vent holes evenly distributed on the side wall and bottom of the inner cylinder, which can achieve rapid vacuuming inside the inner cylinder.

[0058] like Figure 5 As shown, a fixed frame is installed inside the inner cylinder, and the mold is installed on the fixed frame.

[0059] like Figure 2 As shown, the bottom of the casting barrel has a downwardly protruding quick-change connection structure. The connection port extends vertically through the quick-change connection structure. A portion of the side wall of the quick-change connection structure is formed as an annular conical surface. Correspondingly, the upper inner side of the rotating seat is also formed as an annular conical surface. The annular conical surface of the quick-change connection structure connects and mates with the annular conical surface of the rotating seat. This can be understood as the quick-change connection structure having a convex conical surface, and the rotating seat having a concave conical surface. The convex and concave conical surfaces engage and lock together, achieving rapid locking through the weight of the quick-change mold.

[0060] like Figure 3 As shown, the sealing device includes a sealing strip, a locking plate, a sealing cover, and at least two wedge locking mechanisms. The locking plate is formed into a ring, and the lower end of the locking plate is fixed to the upper end of the casting barrel. The sealing cover is placed over the upper opening of the casting barrel. The sealing strip is placed between the upper edge of the casting barrel and the sealing cover. The edge of the sealing cover is connected to the locking plate through at least two wedge locking mechanisms.

[0061] like Figure 4 As shown, there are four wedge locking mechanisms, evenly distributed along the edge of the sealing cover. Specifically, both the locking plate and the sealing cover have pin holes, into which the wedges engage. During operation, simply insert the wedges; for demolding, simply remove them.

[0062] like Figure 3 and 4 As shown, a pouring hole is provided at the center of the top of the sealing cover.

[0063] like Figure 1 As shown, the integrated subframe forming device also includes an electromagnetic drive pump, which is mounted on a casting pipe. The first end of the casting pipe is connected to the outlet of the refining furnace, and the second end is used to insert into the casting hole of the sealing cover. The casting pipe is preferably a ceramic pipe. This application uses an electromagnetic drive pump to achieve precise metering and is equipped with a high-temperature resistant ceramic pipe to achieve pressurized and rapid delivery of molten aluminum alloy.

[0064] The forming method of the integrated subframe forming device includes the following steps:

[0065] S1: Using a mixed metal mold and sand core casting mold, after preheating, core assembly, and mold closing, the casting mold is placed in the inner cylinder and fixed in place by a fixing frame, and the top of the casting barrel is locked with a sealing device.

[0066] S2: Use a forklift to place the quick-change mold into the rotating base, insert the lower end of one quick-change mold into the rotating base for connection, check the air extraction pipe connection, open the air valve, and use the vacuum pump to evacuate the casting barrel, then wait for pouring.

[0067] S3: Electric furnace melting of aluminum alloy, after primary refining and slag removal, it is injected into a holding refining furnace for secondary refining and slag removal, modification, and rotary nitrogen blowing for degassing;

[0068] S4: The second end of the pouring pipe is inserted into the pouring hole of the sealing cover on the mobile pouring platform (the mold barrel is still isolated from the air when inserted); after the refined aluminum alloy liquid reaches the required temperature, the temperature of the alloy liquid reaches 680℃, the electromagnetic drive pump is started to quantitatively press the aluminum alloy liquid into the mold. The pouring time of the 26kg subframe is less than 6 seconds, the vacuum degree is maintained at less than 1 Pa during the pouring process, and the rotation speed is 150 rpm.

[0069] S5: After the molten metal is poured, quickly change the mold and continue rotating for 2 minutes before stopping the machine, closing the gas valve, stopping the vacuuming, and removing the pouring platform. At this time, the electric furnace is charged for the next melting cycle.

[0070] S6: Use a forklift to move the quick-change mold to the cooling and demolding area, open the box and demold to obtain the subframe casting blank;

[0071] S7: Transfer the quick-change mold with the subframe casting blank removed to the mold preparation area for the next pouring. Insert another quick-change mold that has been prepared into the rotating seat to produce the next set of subframe casting blanks.

[0072] The casting method described in this application, which involves online pouring, offline cooling and demolding, and mold preparation, can significantly reduce energy consumption and improve production efficiency.

[0073] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. An integrated subframe forming apparatus characterized by comprising: The utility model relates to a kind of integrated subframe forming device, including: electric furnace for smelting metal;Refining furnace;The metal of electric furnace smelting is input into refining furnace refining, modification, degassing;Centrifugal device;The centrifugal device includes: motor;Rotary seat;The rotary shaft of motor is connected with the lower end of rotary seat;Multiple quick-change casting moulds;The lower end of quick-change casting mould is installed in rotary seat interior by quick-change connection structure, and the metal after refining furnace refining is injected into quick-change casting mould;Quick-change casting mould includes casting barrel, inner cylinder, sealing device, inner cylinder is placed in casting barrel, casting is installed in inner cylinder, sealing device cover is set in the top of casting barrel, and there is gas extraction passage interlayer between casting barrel and inner cylinder, and the upper end of connecting port is communicated with gas extraction passage interlayer, and multiple gas-permeable holes are provided on the wall of inner cylinder;Vacuum pump;There is connecting pipe in rotary seat, vacuum pump is connected with the first end of connecting pipe by rotary joint, connecting port is provided in the bottom of quick-change casting mould and communicated with inside, when quick-change casting mould is installed in rotary seat, connecting port is connected with the second end of connecting pipe, and fixed frame is provided in inner cylinder, and casting is installed on fixed frame. The bottom of casting barrel is provided with downward protruding quick-change connection structure, and connecting port is vertically arranged through quick-change connection structure, and the sidewall of quick-change connection structure is partially formed into annular conical surface, and correspondingly, the upper end of the inner side of rotary seat is also formed into annular conical surface, and the annular conical surface of quick-change connection structure is connected and matched with the annular conical surface of rotary seat. The sealing device includes sealing strip, locking plate, sealing cover, at least two inclined iron locking mechanisms, the locking plate is formed into annular, the lower end of locking plate is fixed on the upper end of casting barrel, the sealing cover is set on the upper end opening of casting barrel, the sealing strip is placed between the upper end edge of casting barrel and sealing cover, and the edge of sealing cover is connected with locking plate by at least two inclined iron locking mechanisms. The four inclined iron locking mechanisms are uniformly distributed at the edge of sealing cover. The top center of sealing cover is provided with pouring hole. The integrated subframe forming device further includes electromagnetic drive pump, the electromagnetic drive pump is installed on pouring pipe, the first end of pouring pipe is connected with the outlet of refining furnace, and the second end of pouring pipe is used for inserting into pouring hole of sealing cover. The method includes the following steps: S1: the casting is placed in the inner cylinder and fixed by the fixed frame, and the casting barrel top is locked by the sealing device; S2: the lower end of a quick-change casting mould is inserted into the rotary seat for connection, and the vacuum pump extracts the vacuum in the casting barrel; S3: the metal is smelted by electric furnace, and after smelting, it is injected into the refining furnace for refining and deslagging, and nitrogen blowing is used for degassing; 2. The integrated subframe forming apparatus according to claim 1, wherein S4: the second end of pouring pipe is inserted into the pouring hole of sealing cover by moving pouring platform, the metal melt is quantitatively pressed into the casting by electromagnetic drive pump, and the motor and quick-change casting mould keep rotating during pouring; 3. The integrated subframe forming apparatus of claim 1, wherein S5: after the metal melt is poured, the quick-change casting mould continues to rotate for a certain time and stops, the vacuum extraction is stopped, and the pouring platform is removed; 4. The integrated subframe forming apparatus according to claim 3, wherein S6: the quick-change casting mould is removed to the cooling and demolding place to open the box and demold, and the subframe casting blank is obtained; 5. The integrated subframe forming apparatus of claim 3, wherein S7: the quick-change casting mould with the subframe casting blank is transferred to the mold preparation place for mold preparation, the next pouring is prepared, and another quick-change casting mould which has been prepared is inserted into the rotary seat for the next group of subframe casting blank production.

6. The integrated subframe forming apparatus of claim 5, wherein ​ 7. The method of claim 1-6, wherein ​ ​ ​ ​ ​ ​ ​ ​

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