Method, process and part for hybrid molding of multi-component materials in a single mold opening and closing

Abstract

This method / process is for hybrid molding multi-component materials, including metallic materials such as ultra-high strength steel pipes, aluminum alloy pipes, and aluminum / magnesium, and non-metallic materials such as fiber-reinforced resins, in a single mold opening and closing operation. This process involves instantaneous heating of the ultra-high strength steel pipes or aluminum alloy pipes, adhesion to the mold by gas expansion forming, quench strengthening, injection molding, and aluminum / magnesium injection, all in a single mold opening and closing operation. This greatly simplifies the part manufacturing process, reduces subsequent processes such as welding, and reduces the weight of tube-beam structural parts. This process is suitable for the integrated manufacturing of ultra-high strength tube-beam structures with special cross-sections. The present invention also relates to multi-component material parts produced by the above method.

Description

[Technical Field]

[0001] The present invention pertains to a method for producing components such as vehicle tube beams, and more particularly to a method, process and part for hybrid molding of multiple materials in a single mold opening and closing. [Background technology]

[0002] The design and processing process of tube beam structural parts determine the evaluation indexes of the overall vehicle, such as safety, reliability, durability, and NVH. However, steel tube beam structures manufactured using traditional one-piece die-casting and stamping welding processes have certain limitations in improving the overall vehicle performance and weight reduction.

[0003] Although the one-piece die casting process is widely used in the automotive industry, it is limited to being suitable for casting materials such as aluminum alloys and magnesium alloys that lack sufficient strength and density (yield strength of around 300 MPa). It is therefore not suitable for manufacturing slender upper body tubular beam structural parts or subassemblies, such as subassembly parts such as A-pillars and B-pillars. When one-piece die casting large parts such as vehicle side panels, the clamping force of the equipment becomes very large, resulting in significant deformation of the parts and insufficient local strength for parts such as the slender A-pillar tubular beams, which complicates the manufacturing process and increases costs.

[0004] The conventional integrated injection molding process for pipe beams and connecting parts is limited to the injection molding of the finished pipe beam and the water expansion molding. The raw pipe of the main load-bearing pipe part is not subjected to processes such as heating, gas expansion molding to adhere to the mold, and quenching. This makes it difficult to achieve the ideal shape and strength performance of the special-shaped pipe beam. In addition, a new process is added to complete the connection without combining it with processes such as synchronized aluminum / magnesium casting.

[0005] Conventional liquid-filled hydroforming of pipes involves sealing both ends of a metal pipe in a cold state, injecting high-pressure liquid into the pipe, and forcing the original pipe material into a mold. This process typically involves liquid-filling machines, cold liquid filling, and materials with low yield strength. Ultra-high-strength titanium alloys with high yield strength are not suitable for water-filling because they cannot be cold-formed and have high requirements for the clamping force of the equipment.

[0006] Hybrid molding is aimed at parts that are molded in a cold state, such as some parts that require assembling plastic clips to metal structural parts (for example, dashboard brackets in automobiles). Traditional hybrid molding combines liquid-filled molding of tubular materials with injection molding to mold the entire structure in one process, but this method has simple temperature control, the molding temperature is only about 200 degrees, and a quenching process cannot be performed.

[0007] As mentioned above, traditional hot gas expansion molding, injection molding, die casting, and liquid-filled molding of tubing are all single-step processes that cannot mold parts with composite structures. Hybrid molding is intended for parts that are molded in a cold state and is not suitable for high-strength materials.

[0008] In order to meet the rigidity, strength, and weight requirements of vehicle body structures, the present invention provides a method, process, and parts for hybrid molding of multi-component materials, including metallic materials such as ultra-high strength steel pipes, aluminum alloy pipes, and aluminum / magnesium, and non-metallic materials such as fiber-reinforced resins, in a single mold opening and closing operation. This method achieves instantaneous heating of ultra-high strength steel pipes (or aluminum alloy pipes, etc.), adhesion to the mold by gas expansion molding, quenching strengthening, injection molding (for non-metallic materials such as fiber-reinforced resins), and aluminum / magnesium (metal) casting in a single mold opening and closing operation, thereby greatly simplifying the vehicle body manufacturing process, reducing subsequent processes such as welding, and reducing the weight of tube-beam structural parts. It is suitable for the integrated manufacturing of ultra-high strength tube-beam structures with special cross-sections. Summary of the Invention

[0009] The present invention provides a method for manufacturing a mold, comprising the steps of: placing a metal raw tube into a mold cavity; closing the mold to seal both ends of the metal tube; heating the metal tube to a first predetermined temperature; a metal raw tube stretch forming step of injecting a first high-pressure stretch forming medium into one of the tube openings of the metal raw tube to bring the wall of the metal raw tube into close contact with the die, the metal tube expansion step injecting a first pressure expansion medium into a space between the die cavity and the outside of the metal tube in order to control the amount of deformation at a local position of the metal tube; a first material injection step of recovering a first pressure bulging medium by releasing the pressure, adjusting the temperature of the mold cavity to a second predetermined temperature, and injecting a liquid or semi-solid first material into a first material space formed between the inner wall of the mold cavity and the outer wall of the metal tube, thereby integrally molding and bonding the first material onto the bulged metal tube, wherein the first material is different from the metal material of the metal tube; The present invention relates to a method for hybrid molding a multi-component material in a single mold opening and closing operation, which further includes rapidly quenching the material in the mold and then demolding the material.

[0010] Preferably, during the entire process of injecting the first material, in order to control the amount of deformation at a local position of the metal base tube, a second low-pressure expansion molding medium is injected into a second material space formed between the inner wall of the mold cavity and the outer wall of the metal base tube, and the second material is different from the first material and the metal material of the metal base tube.

[0011] Preferably, the method further includes, after the first material injection step and before quenching, a step of decompressing and recovering the second pressure bulging medium, and a step of adjusting the temperature of the mold cavity to a third predetermined temperature and injecting a liquid or semi-solid second material into the second material space formed between the inner wall of the mold cavity and the outer wall of the metal base tube, thereby integrally molding and bonding the second material and the first material onto the bulged metal base tube, or, The first material injection further includes a step of injecting a liquid or semi-solid second material into a second material space formed between the inner wall of the mold cavity and the outer wall of the metal base tube, thereby integrally molding and joining the second material and the first material onto the metal base tube after the expansion molding.

[0012] Preferably, a third pressure bulging medium is injected into the metal base tube to control the amount of deformation at a local position on the base tube during the entire process of injecting the first material, and a fourth pressure bulging medium is injected into the metal base tube to control the amount of deformation at a local position on the base tube during the entire process of injecting the second material.

[0013] Preferably, the first material is a metal and the second material is a non-metal.

[0014] Preferably, the first material is aluminium, magnesium or an aluminium-magnesium alloy, and the second material is a composite material such as plastic or fibre-reinforced resin.

[0015] Preferably, the types of metal base tube include a steel base tube, an aluminum base tube, a carbon-coated tube, and a carbon-coated tube filled with a reinforcing material, the carbon-coated tube being a metal base tube coated with a carbon fiber material on its outer layer, and the carbon-coated tube filled with a reinforcing material being a metal base tube filled with aluminum foam, polystyrene foam, or a foaming agent.

[0016] Preferably, the second predetermined temperature is equal to or lower than the first predetermined temperature, and the third predetermined temperature is lower than the second predetermined temperature.

[0017] The present invention further relates to a process for hybrid molding of multiple materials in a single mold opening and closing operation using the method.

[0018] The invention further relates to a multi-material part manufactured by the above-described method. [Effects of the Invention]

[0019] The present invention can achieve processes such as instantaneous heating of ultra-high strength metal tube components (e.g., aluminum alloy tubes), adhesion to the mold by gas expansion molding, quenching strengthening, non-metal injection (e.g., plastic, fiber-reinforced resin, etc.), and metal injection (e.g., aluminum / magnesium / aluminum-magnesium alloy, etc.) within a single mold opening and closing process, making it suitable for the integrated production of automobile sub-assembly parts. [Brief explanation of the drawings]

[0020] [Figure 1] FIG. 1 is a structural schematic diagram of the equipment of the present invention. [Figure 2] 1 is a flow chart of the process of the present invention. [Figure 3] FIG. 2 is a schematic diagram of a different metal base tube of the present invention. [Figure 4] FIG. 2 is a schematic diagram of a process for placing a metal base tube of the present invention into a mold. [Figure 5] FIG. 2 is a schematic diagram of the stretch-forming process for a metal tube according to the present invention. [Figure 6] 1 is a schematic diagram of metal injection of the present invention. [Figure 7] 1 is a schematic diagram of non-metal injection of the present invention. [Figure 8] 1 is a schematic diagram of the pressure release and quenching of the bulging molding medium of the tube beam of the present invention. [Figure 9] 1 is a schematic diagram of the release of the pipe beam product of the present invention. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0021] The technical solutions of the present invention will be described clearly and completely below with reference to the drawings, but it is clear that the described embodiments are only a part of the embodiments of the present invention, and are not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without any creative work fall within the protection scope of the present invention.

[0022] In describing the present invention, the directions or positional relationships indicated by terms such as "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer" are based on the directions or positional relationships shown in the drawings and are intended merely to facilitate and simplify the description of the present invention, and are not intended to indicate or suggest that such devices or elements have a particular orientation or must be configured and operated in a particular orientation, and should not be understood as limiting the present invention. Furthermore, the terms "first," "second," and "third" are intended for descriptive purposes only and should not be understood as indicating or suggesting relative importance.

[0023] In the description of the present invention, unless otherwise expressly specified or limited, the terms "attach," "couple," and "connect" should be understood in a broad sense. For example, they may be fixedly connected, detachably connected, or integrally connected. They may be mechanically connected or electrically connected. They may be directly connected, indirectly connected via an intermediate medium, or internal communication between two elements. The specific meanings of the above terms in the present invention can be specifically understood by those skilled in the art.

[0024] As shown in FIG. 1, the equipment for achieving hybrid molding of multiple materials with a single mold opening and closing includes a supply conveyor line 1, a main body 2, a discharge conveyor line 3, a release agent spray robot 4, an ultra-high pressure medium system 5, a mold temperature control system 6, a non-metallic material injection system 7, a metallic material injection system 8, a high-power heating system 9, a release agent injection system 10, and a part transport system 11.

[0025] The supply conveyor line 1 typically uses a belt conveyor or a pneumatic slide table to supply the raw metal pipes, which are ultra-high strength steel pipes or aluminum alloy pipes.

[0026] The body 2 includes a mold cavity and realizes mold opening and closing.

[0027] The discharge conveyor line 3 transports the formed workpieces and has a function of temporarily storing parts. The discharge conveyor line is usually made of stainless steel or steel plate chain.

[0028] The release agent spray robot 4 sprays release agent on the surface of the mold cavity before each part enters the cavity, making it easier to release the molded part. The release agent spray robot 4 is connected to the release agent injection system via piping. The release agent spray robot is a six-axis robot or a crossbar robot equipped with release agent spray tooling.

[0029] The ultra-high pressure medium system 5 is used for loading, holding and recovering the ultra-high pressure medium during the hot gas expansion forming process of the metal tube, and can also discharge the low pressure expansion medium. Preferably, the expansion medium can be any of gas, water, oil and low melting point metal. Preferably, the expansion medium is nitrogen or inert gas, and the low melting point metal is tin.

[0030] The mold temperature control system 6 raises or lowers the temperature of the parts in the mold by injecting a medium at a specific temperature into the mold through piping.

[0031] The non-metallic material injection system 7 includes a non-metallic injection channel and a non-metallic material injection barrel. The non-metallic material injection barrel is connected to the mold cavity of the main body 2 via the non-metallic injection channel and is used to inject a non-metallic medium into the mold cavity. The non-metallic material injection barrel contains the non-metallic medium required for part molding, and has the functions of heating and stirring, so as to melt the solid non-metallic medium into a liquid or semi-solid non-metallic medium for easy injection into the mold cavity.

[0032] The metal material injection system 8 includes a metal injection channel and a metal material injection barrel. The metal material injection barrel is connected to the mold cavity of the main body 2 via the metal injection channel and is used to inject a metal medium into the mold cavity. The metal material injection barrel contains the metal medium required for part molding, and has the functions of heating and stirring, so as to melt the solid metal medium into a liquid or semi-solid metal medium for easy injection into the mold cavity.

[0033] The high power heating system 9 is connected to the electrodes via conductors and is used to heat the part within the mold cavity.

[0034] The release agent spraying system 10 is used to store and transport the release agent, and is connected to a release agent spray robot via a release agent pipe to spray the release agent into the cavity.

[0035] Parts Transfer System 11: The parts transfer system consists of a supply robot arm, a discharge robot arm, and a gantry frame, enabling the supply and discharge of materials during production. The robot arm has a high temperature resistance to prevent heat erosion when gripping parts. The parts transfer system can also be replaced with two 6-axis robots.

[0036] FIG. 2 shows the core steps of the method for hybrid molding multi-component materials in a single mold opening and closing operation. More specifically, the method for hybrid molding multi-component materials in a single mold opening and closing operation includes the following steps:

[0037] The supply conveyor line 1 transports the metal raw tube to the supply position, and at the same time, the release agent spray robot 4 and the release agent injection system 10 operate to spray the release agent into the mold cavity in the main body 2. Figure 3 shows a schematic diagram of the types of metal raw tubes of the present invention, which include a steel raw tube 21, an aluminum raw tube 21, a carbon-coated tube 22, and a carbon-coated tube 23 filled with a reinforcing material, and the carbon-coated tube is a metal raw tube coated with a carbon fiber material on the outer layer.

[0038] The parts conveying system 11 holds the metal tube in the mold cavity in the main body 2, and as shown in Figure 4, the main body operates to close the mold, and the side thrust cylinders of the main body 2 operate to seal both ends of the metal tube with plugs on both sides.

[0039] The high-power heating system 9 heats the metal tube to a predetermined temperature by means of electrodes, and at the same time, the mold temperature control system 6 controls the mold cavity to be adjusted to a first predetermined temperature.

[0040] Metal tube expansion forming: As shown in Figure 5, the ultra-high pressure medium system 5 injects a first-pressure, high-pressure expanding medium (e.g., high-pressure gas) into one of the openings of the metal tube, and the first-pressure, high-pressure expanding medium tightly contacts the wall of the metal tube with the mold through high-pressure expanding. The ultra-high pressure medium system 5 also injects a first-pressure expanding medium (e.g., low-pressure gas) into the mold cavity and the space outside the metal tube to control the amount of deformation at a local position on the metal tube. Preferably, the first-pressure expanding medium is injected and withdrawn via a metal injection channel 15 and a non-metal injection channel 13.

[0041] Metal injection: As shown in FIG. 6, the first pressure-expanding medium is released and recovered. The mold temperature control system 6 adjusts the mold cavity to a second predetermined temperature, which is equal to or lower than the first predetermined temperature. The metal material injection system 8 injects a liquid or semi-solid metal, such as an aluminum-magnesium alloy, into the mold cavity and the metal injection space outside the metal tube through the metal injection barrel, thereby forming and bonding the metal material integrally onto the metal tube after expansion. During the entire metal injection process, the ultra-high pressure medium system 5 injects a third pressure-expanding medium into the metal tube to control the amount of deformation at a local position on the tube. Furthermore, during the entire metal injection process, the ultra-high pressure medium system 5 injects a second pressure-expanding medium into the mold cavity and the space outside the metal injection space to control the amount of deformation at a local position on the tube.

[0042] Non-metal injection: As shown in Figure 7, the second pressure bulging medium is released and recovered. The mold temperature control system 6 adjusts the mold cavity to a third predetermined temperature, which is lower than the first or second predetermined temperature. The non-metal material injection system 7 injects a liquid or semi-solid non-metal, such as plastic, into the mold cavity and the non-metal injection space outside the metal tube through the non-metal injection barrel, thereby molding and bonding the non-metal material to the bulged metal tube. During the entire non-metal injection process, the ultra-high pressure medium system injects a fourth pressure bulging medium into the metal tube to control the amount of deformation at local locations on the tube.

[0043] Preferably, the metal injection and non-metal injection steps of the present invention may be performed simultaneously for efficiency.

[0044] As shown in Figure 8, the bulging media is recovered by decompression and rapidly quenched in the mold.

[0045] As shown in Figure 9, after molding is completed, the main body 2 opens the mold, and the part transport system 11 holds the multi-component material part after hybrid molding on the discharge conveyor system 3, which then transports the molded part to a predetermined position.

[0046] It should be understood that the magnitude of the sequence number of each step in the embodiments of the present invention does not mean the order of execution, and the execution order of each process should be determined by its function and inherent logic, and should not in any way limit the execution procedure of the embodiments of the present invention.

[0047] Although embodiments of the present invention have been shown and described, those skilled in the art will recognize that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and spirit of the present invention, and the scope of the present invention is limited by the appended claims and their equivalents. [Explanation of symbols]

[0048] 1 supply conveyor line, 2 main body, 3 discharge conveyor line, 4 release agent spray robot, 5 ultra-high pressure medium system, 6 mold temperature control system, 7 non-metal injection system, 8 metal injection system, 9 high-power heating system, 10 release agent injection system, 11 part transport system; 21 Aluminum or steel pipe, 22 Carbon fiber, 23 Reinforcement material 111 metal base tube, 13 non-metal injection flow path, 14 mold, 15 metal injection flow path, 16 bulging molding medium, 17 non-metal injection space, 18 metal injection space

Claims

1. placing a metal tube into a mold cavity; closing the mold to seal both ends of the metal tube; heating the metal tube to a first predetermined temperature; a metal raw tube stretch forming step of injecting a first high-pressure stretch forming medium into one of the tube openings of the metal raw tube, thereby bringing the tube wall of the metal raw tube into close contact with the die, specifically in this order, The metal tube expansion step includes injecting a first pressure expansion medium into a space formed between an inner wall of the die cavity and an outer wall of the metal tube to control a deformation amount at a local position of the metal tube; a first material injection step of recovering a first pressure bulging medium by releasing the pressure, adjusting the temperature of the mold cavity to a second predetermined temperature, and injecting a liquid or semi-solid first material into a first material space formed between the inner wall of the mold cavity and the outer wall of the metal base tube, thereby integrally molding and bonding the first material onto the bulged metal base tube, wherein the first material is different from the metallic material of the metal base tube; A method for hybrid molding a multi-component material by opening and closing the mold once, further comprising rapidly quenching the material in the mold and releasing the mold.

2. 2. The method according to claim 1, characterized in that a second pressure expansion molding medium is injected into a second material space formed between the inner wall of the mold cavity and the outer wall of the metal base tube to control the deformation amount of a local position of the metal base tube during the entire process of injecting the first material, and the second material is different from the first material and the metal material of the metal base tube.

3. the method further includes the steps of: releasing and recovering the second pressure bulging medium after the first material injection step and before quenching; adjusting the temperature of the mold cavity to a third predetermined temperature; injecting a liquid or semi-solid second material into a second material space formed between the inner wall of the mold cavity and the outer wall of the metal base tube; and integrally molding and bonding the second material and the first material onto the bulged metal base tube; or, The method according to claim 2, characterized in that the first material injection further includes a step of injecting a liquid or semi-solid second material into a second material space formed between the inner wall of the mold cavity and the outer wall of the metal base tube, thereby integrally molding and bonding the second material and the first material onto the metal base tube after stretch-forming.

4. The method according to claim 3, characterized in that a third pressure bulging medium is synchronously injected into the metal base tube to control the amount of deformation at a local position of the base tube during the entire process of injecting the first material, or a fourth pressure bulging medium is synchronously injected into the metal base tube to control the amount of deformation at a local position of the base tube during the entire process of injecting the second material.

5. The method according to any one of claims 3 to 4, characterized in that the first material is metallic and the second material is non-metallic.

6. 5. A method according to any one of claims 3 to 4, characterized in that the first material is aluminium, magnesium or an aluminium magnesium alloy and the second material is a plastic or composite material.

7. The method according to any one of claims 1 to 4, characterized in that the types of the metal base tube include a steel base tube, an aluminum base tube, a carbon-coated tube, and a carbon-coated tube filled with a reinforcing material, the carbon-coated tube being a metal base tube coated with a carbon fiber material on its outer layer, and the carbon-coated tube filled with a reinforcing material being a metal base tube filled with aluminum foam, polystyrene foam, or a foaming agent.

8. 5. The method according to claim 3, wherein the second predetermined temperature is equal to or lower than the first predetermined temperature, and the third predetermined temperature is lower than the first predetermined temperature or the second predetermined temperature.

9. A process for hybrid molding of multi-component materials in a single mold opening and closing operation, characterized by using the method according to any one of claims 1 to 8.

10. A multi-material part, characterized in that it is produced by the method according to any one of claims 1 to 8.

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