Hot-gas bulging A and B column tubular beam and aluminum alloy integrated die-casting forming method and hot-gas bulging A and B column tubular beam and aluminum alloy integrated die-casting forming structure

Abstract

According to the hot gas bulging A and B column tubular beam and aluminum alloy integrated die-casting forming method, the hot gas bulging forming technology and the die-casting technology are organically combined, the rigidity and strength of A and B column framework structures are greatly improved, meanwhile, the connecting structure of a vehicle body force bearing framework is simplified, the number of parts is reduced, and the cost is reduced. And therefore, the weight and the production cost of the bearing framework structure are greatly reduced. Welding procedures needed by a traditional technology are greatly reduced in the manufacturing process, the yield and the use reliability can be improved, the production efficiency can be remarkably improved, and the requirement for large-scale batch production is met.

Description

Technical Field

[0001] The invention belongs to the technical field of automobile body skeleton structural parts manufacturing, and specifically relates to a hot air bulging A, B column tube beam and aluminum alloy integral die-casting molding method and structure. Background Art

[0002] In the load-bearing skeleton structure of the automobile body, the A-pillar and the B-pillar are important components for collision protection. The dual improvement of their structural strength and lightweight indicators has always been a technical problem that has been solved in this field. The traditional manufacturing process of the A-pillar and B-pillar skeleton is mostly to manufacture some steel parts separately first, and then weld the parts. Although the strength of the finished product can be guaranteed, the lightweight performance is also ignored; in some recent manufacturing processes, the use of hot air expansion tube beams combined with hot forming technology can achieve both strength and lightweight performance, but it also brings higher equipment and mold use and maintenance costs. Summary of the invention

[0003] In view of this, in order to solve the technical problems existing in the art, the present invention provides a hot air bulging A and B column tube beam and aluminum alloy integral die casting method and structure, which specifically includes the following steps:

[0004] Step 1: Select suitable ultra-high strength pipe blanks and carry out preparatory work including pre-cutting, grinding, deburring and cleaning according to design specifications;

[0005] Step 2: According to the bending shapes of the A-pillar and the B-pillar, firstly, the corresponding blank is bent to obtain the intermediate process parts of the bent pipe; and then the intermediate process parts of the bent pipe are pre-pressed and formed;

[0006] Step 3: Place the pre-pressed parts corresponding to the A-pillar and the B-pillar into the mold, perform hot air expansion forming, fill the tube cavity heated to a thermoplastic state with high-pressure gas to expand it and fit the mold shape, and obtain hot air expansion tube beam components corresponding to the A-pillar, the first B-pillar, and the second B-pillar respectively; then, remove the hot air expansion tube beam component from the mold after in-mold quenching and cooling;

[0007] Step 4: Cut the two ends of the A-pillar tube beam and the lower ends of the first B-pillar tube beam and the second B-pillar tube beam respectively to form open ports for inflation and pressure maintenance in the subsequent aluminum alloy die-casting process, and weld and seal the upper ends of the first B-pillar tube beam and the second B-pillar tube beam respectively;

[0008] Step 5, welding the A-pillar tube beam, the first B-pillar tube beam and the second B-pillar tube beam placed side by side in the front and rear into a whole, so that the middle part of the A-pillar tube beam, the upper ends of the first B-pillar tube beam and the second B-pillar tube beam are firmly connected;

[0009] Step 6: Place the A-pillar tube beam and the first and second B-pillar tube beams as a whole into a die-casting mold, inflate the tube beam component through the open end to maintain pressure, and at the same time, inject the molten aluminum alloy into the cavity of the die-casting mold to form an aluminum alloy connector at the connection position of the middle part of the A-pillar tube beam, the first B-pillar tube beam, and the second B-pillar tube beam at their respective upper ends;

[0010] Step 7: After die casting is completed and cooled to eliminate stress, the mold is opened to remove the parts, the slag bag is removed and the pressure-maintaining open port is cut off to obtain the integral structure of the A-pillar and B-pillar.

[0011] Furthermore, in step 1, the ultra-high strength pipe blank is specifically selected from BR1500HS high-strength steel or boron steel, and the material thickness is 0.8-4.0 mm.

[0012] Furthermore, in step six, A380 aluminum alloy material is specifically used to perform die casting; the thickness of the aluminum alloy connector after die casting is 3.0 mm.

[0013] Furthermore, the aluminum alloy connector formed by die casting in step six includes a plurality of reinforcing ribs.

[0014] Furthermore, in step 6, only the A-pillar tube beam is placed in the die-casting mold for inflation and pressure maintenance and aluminum alloy die-casting, and an aluminum alloy connector is formed at a position where the middle portion thereof is connected to the upper ends of the first and second B-pillar tube beams; and before the die-casting step, the welding and plugging operation of the first and second B-pillar tube beams and the operation of welding the A-pillar and the first and second B-pillar tube beams into a whole are canceled;

[0015] After the A-pillar tube beam is die-cast and demolded, the A-pillar tube beam, the first B-pillar tube beam and the third B-pillar tube beam are fastened and connected into a whole at the aluminum alloy connecting parts by bolts to obtain the final A-pillar and B-pillar overall structure.

[0016] Correspondingly, the present invention also provides a hot-air-bulged A-pillar and B-pillar tube beam and aluminum alloy integral die-casting structure manufactured by executing the aforementioned method.

[0017] The hot-air bulging A and B column tube beam and aluminum alloy integrated die-casting forming method provided by the present invention organically combines the hot-air bulging forming process with the die-casting process, greatly improving the rigidity and strength of the A and B column skeleton structure, while simplifying the connection structure of the vehicle body load-bearing skeleton and reducing the number of parts, thereby greatly reducing the weight and production cost of the load-bearing skeleton structure. The present invention greatly reduces the welding process required by the traditional process in manufacturing, which is not only conducive to improving the yield rate and reliability in use, but also can significantly improve production efficiency, meeting the needs of large-scale batch production. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1This is a schematic diagram of the A-pillar hot-expanded tubular beam component;

[0019] Figure 2 It is a schematic diagram of the front and rear B-pillar hot-expanded tube beam components;

[0020] Figure 3 This is a schematic diagram of the welding of the A-pillar and B-pillar tube beams;

[0021] Figure 4 It is a schematic diagram of performing inflation and pressure holding through the pressure holding open port during die casting;

[0022] Figure 5 This is a schematic diagram of the overall structure of the A-pillar and B-pillar obtained after die-casting;

[0023] Figure 6 It is a schematic diagram of the preferred structure of an aluminum alloy connector;

[0024] Figure 7 It is a schematic diagram of an aluminum alloy connector obtained by die-casting only the A-pillar in an alternative embodiment of the present invention. DETAILED DESCRIPTION

[0025] The technical solution of the present invention will be described clearly and completely below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0026] In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance.

[0027] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it 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 it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0028] The present invention provides a hot-gas-expanded A-pillar and B-pillar tube beam and aluminum alloy integral die-casting method and structure, which specifically includes the following steps:

[0029] Step 1: Select suitable ultra-high strength pipe blanks and carry out preparatory work including pre-cutting, grinding, deburring and cleaning according to design specifications;

[0030] Step 2: According to the bending shapes of the A-pillar and the B-pillar, firstly, the corresponding blank is bent to obtain the intermediate process parts of the bent pipe; and then the intermediate process parts of the bent pipe are pre-pressed and formed;

[0031] Step 3: Place the pre-pressed parts corresponding to the A-pillar and the B-pillar into the mold, perform hot air expansion forming, and fill the tube cavity heated to the thermoplastic state with high-pressure gas to expand it and fit the mold shape to obtain hot air expansion tube beam components corresponding to the A-pillar, the first B-pillar, and the second B-pillar, respectively. Figure 1 , 2 As shown; then the hot-expanded tube beam component is taken out of the mold after in-mold quenching and cooling;

[0032] Step 4: Cut the two ends of the A-pillar tube beam 1 and the lower ends of the first B-pillar tube beam 2 and the second B-pillar tube beam 3 to form open ports for inflation and pressure maintenance in the subsequent aluminum alloy die-casting process, and weld and seal the upper ends of the first B-pillar tube beam and the second B-pillar tube beam;

[0033] Step 5: Figure 3 As shown, the A-pillar tube beam is welded to a first B-pillar tube beam and a second B-pillar tube beam placed side by side in the front and rear to form a whole 5, so that a fastening connection is formed between the middle part of the A-pillar tube beam, the upper ends of the first B-pillar tube beam and the second B-pillar tube beam;

[0034] Step 6: Figure 4 As shown, the A-pillar tube beam and the first and second B-pillar tube beams are integrally placed in a die-casting mold, and a sealing pusher is set at the pressure-maintaining open port of each tube beam component. Under the action of the oil cylinder at each sealing pusher, air is inflated into the hot gas expansion tube beam component to achieve inner cavity pressure maintenance to prevent the tube beam components from being deformed during die casting. At the same time, the molten aluminum alloy is injected into the cavity of the die-casting mold. The aluminum alloy connector 4 is formed at the connection position of the middle part of the A-pillar tube beam, the first B-pillar tube beam and the second B-pillar tube beam through the die-casting process. Its external and internal cross-sections are as shown in FIG. Figure 6 As shown;

[0035] Step 7: Figure 5 As shown, after die casting is completed and cooled to eliminate stress, the mold is opened to remove the parts, the slag bag is removed and the pressure-maintaining open port is cut off to obtain the integral structure of the A-pillar and B-pillar.

[0036] In a preferred embodiment of the present invention, in step 1, the ultra-high strength pipe blank is specifically selected from BR1500HS high-strength steel or boron steel, and the material thickness is 0.8-4.0 mm.

[0037] In a preferred embodiment of the present invention, in step six, A380 aluminum alloy material is specifically used to perform die casting; the thickness of the aluminum alloy connector after die casting is 3.0 mm.

[0038] In a preferred embodiment of the present invention, the aluminum alloy connector formed by die casting in step six comprises a plurality of reinforcing ribs.

[0039] In a preferred embodiment of the present invention, in step 6, only the A-pillar tube beam is placed in the die-casting mold for inflation and pressure maintenance and aluminum alloy die-casting, and a portion of the A-pillar tube beam connected to the upper ends of the first and second B-pillar tube beams is formed as follows: Figure 7 The aluminum alloy connector shown in the figure; and, before the die-casting step, the welding and plugging operation of the first B-pillar tube beam and the second B-pillar tube beam, and the operation of welding the A-pillar and the first and second B-pillar tube beams into a whole are eliminated;

[0040] After the A-pillar tube beam is die-cast and demolded, the A-pillar tube beam, the first B-pillar tube beam and the third B-pillar tube beam are fastened and connected into a whole at the aluminum alloy connecting parts by bolts to obtain the final A-pillar and B-pillar overall structure.

[0041] Correspondingly, the present invention also provides a hot-air-bulged A-pillar and B-pillar tube beam and aluminum alloy integral die-casting structure manufactured by executing the aforementioned method.

[0042] It should be understood that the size of the serial numbers of the steps in the embodiment of the present invention does not mean the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiment of the present invention.

[0043] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A hot-gas-bulging A-pillar and B-pillar tube beam and aluminum alloy integral die-casting method and structure, characterized in that: The specific steps include: Step 1: Select suitable ultra-high strength pipe blanks and carry out preparatory work including pre-cutting, grinding, deburring and cleaning according to design specifications; Step 2: According to the bending shapes of the A-pillar and the B-pillar, firstly, the corresponding blank is bent to obtain the intermediate process parts of the bent pipe; and then the intermediate process parts of the bent pipe are pre-pressed and formed; Step 3: Place the pre-pressed parts corresponding to the A-pillar and the B-pillar into the mold, perform hot air expansion forming, fill the tube cavity heated to a thermoplastic state with high-pressure gas to expand it and fit the mold shape, and obtain hot air expansion tube beam components corresponding to the A-pillar, the first B-pillar, and the second B-pillar respectively; then, remove the hot air expansion tube beam component from the mold after in-mold quenching and cooling; Step 4: Cut the two ends of the A-pillar tube beam and the lower ends of the first B-pillar tube beam and the second B-pillar tube beam respectively to form open ports for inflation and pressure maintenance in the subsequent aluminum alloy die-casting process, and weld and seal the upper ends of the first B-pillar tube beam and the second B-pillar tube beam respectively; Step 5, welding the A-pillar tube beam, the first B-pillar tube beam and the second B-pillar tube beam placed side by side in the front and rear into a whole, so that the middle part of the A-pillar tube beam, the upper ends of the first B-pillar tube beam and the second B-pillar tube beam are firmly connected; Step 6: Place the A-pillar tube beam and the first and second B-pillar tube beams as a whole into a die-casting mold, inflate the tube beam component through the open end to maintain pressure, and at the same time, inject the molten aluminum alloy into the cavity of the die-casting mold to form an aluminum alloy connector at the connection position of the middle part of the A-pillar tube beam, the first B-pillar tube beam, and the second B-pillar tube beam at their respective upper ends; Step 7: After die casting is completed and cooled to eliminate stress, the mold is opened to remove the parts, the slag bag is removed and the pressure-maintaining open port is cut off to obtain the integral structure of the A-pillar and B-pillar.

2. The method according to claim 1, characterized in that: In step 1, the ultra-high strength pipe blank is specifically selected from BR1500HS high-strength steel or boron steel, and the material thickness is 0.8-4.0mm.

3. The method according to claim 1, characterized in that: In step six, A380 aluminum alloy material is used for die casting; the thickness of the aluminum alloy connector after die casting is 3.0 mm.

4. The method according to claim 1, characterized in that: Step 6: The aluminum alloy connector formed by die casting includes a plurality of reinforcing ribs.

5. The method according to claim 1, characterized in that: In step 6, only the A-pillar tube beam is placed in the die-casting mold for inflation and pressure maintenance and aluminum alloy die-casting, and an aluminum alloy connector is formed at the position where the middle part is connected to the upper ends of the first and second B-pillar tube beams; and before the die-casting step, the welding and plugging operation of the first B-pillar tube beam and the second B-pillar tube beam is canceled, and the operation of welding the A-pillar and the first and second B-pillar tube beams into a whole is canceled; After the A-pillar tube beam is die-cast and demolded, the A-pillar tube beam, the first B-pillar tube beam and the third B-pillar tube beam are fastened and connected into a whole at the aluminum alloy connecting parts by bolts to obtain the final A-pillar and B-pillar overall structure.

6. A hot-gas-expanded A-pillar and B-pillar tube beam and aluminum alloy integral die-casting structure, characterized in that: The method is manufactured by the method according to any one of claims 1 to 5.

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