Device and method for manufacturing integral drive axle housing of truck

Abstract

The invention provides a manufacturing device and method for an integral drive axle housing of a truck. The device comprises a heating system, a forming mold, an air expansion system, a vacuum system and a flow guide shaft sleeve, a pipe is assembled on the outer wall of the flow guide shaft sleeve, the pipe and the flow guide shaft sleeve are installed in a cavity of the forming mold, and the heating system is installed on the forming mold and used for heating the pipe; the inflatable system is connected with the forming die and the flow guide shaft sleeve and used for bulging the heated pipe through gas pressure, the cavity is filled with the heated pipe, and the needed drive axle housing shape is formed; the vacuum system is connected with the forming mold and the flow guide shaft sleeve and used for providing a vacuum or vacuum-like environment. The metal material which is difficult to machine at normal temperature can be formed, the precision and strength of the product are remarkably improved, the application range of the forming technology is expanded, meanwhile, the adaptability of the technology is optimized, and the manufacturing cost is reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of mechanical manufacturing, and in particular to a device and method for preparing an integral drive axle housing of a truck. Background Art

[0002] In the field of modern automobile manufacturing, with the continuous improvement of vehicle performance requirements, the design and manufacturing technology of automobile parts are also constantly developing. Especially in the manufacture of trucks, the drive axle housing is a core component, and its performance directly affects the vehicle's load-bearing capacity, driving stability and service life. Traditional drive axle housings are usually manufactured using processes such as casting, stamping and welding. Although these methods have been widely used in the past, with the increasing demand for lightweight, high-strength and complex shapes of automobiles, these traditional processes have gradually exposed many shortcomings such as low processing accuracy, low material utilization, and long manufacturing cycle.

[0003] In recent years, with the development of materials science and forming technology, new materials (such as high-strength steel, titanium alloy, etc.) have been used more and more widely. Although these materials have the advantages of high strength, corrosion resistance and light weight, they are difficult to form at room temperature and require extremely high processing technology. Therefore, the development of a new manufacturing technology that can efficiently form these difficult-to-process materials has become an urgent problem to be solved in the field of automobile manufacturing. Hot air forming technology has gradually become a potential technical solution to this problem because it can cause materials to undergo plastic deformation under gas pressure under high temperature conditions. It has great application potential, especially in the forming of complex structural parts in a vacuum or quasi-vacuum environment.

[0004] At present, there are many related patents on the forming technology of automobile drive axle housing, but these patents are mainly focused on hydraulic bulging and water swelling forming technology, and their applicability to difficult-to-form materials such as titanium alloy is relatively limited. In addition, the raw material for axle housing forming in the prior art is welded pipe, and welded pipe forming is not involved.

[0005] The patent document with publication number CN202311785889 discloses a hydraulic bulging technology for stepped tubes with conical surfaces. By designing a variety of axial feeding methods, flexible forming of pipe fittings is achieved. Its main feature is that through the cooperation between the hydraulic press and the mold, the wall thickness reduction rate of the expanded pipe fittings is reduced and the limit bulging rate is increased. However, this process is mainly used for conventional metal materials, and its adaptability to forming complex materials in high temperature environments is insufficient, and it is difficult to meet the forming requirements of difficult materials such as titanium alloys.

[0006] The patent document with publication number CN202311547325 discloses a water swelling forming process for a vacuum integrated bridge shell, which injects high-pressure water into the interior of the steel tube material to expand it into the bridge shell body in the mold. This process simplifies the assembly process, ensures the concentricity and sealing of the product, and is suitable for the forming of steel materials. However, the water swelling forming process has limited adaptability to high-strength and difficult-to-form materials, especially under high temperature and vacuum conditions, and the water swelling process is difficult to achieve precise complex shape forming.

[0007] Patent document with publication number CN201010146622 discloses a semi-sliding hydraulic bulging process, which is suitable for the manufacture of automobile axle housing parts. Through two hydraulic bulging processes, the process can better control the shape and dimensional accuracy of the parts, and improve the strength and rigidity of the parts. However, it still relies on hydraulic bulging technology and cannot effectively meet the needs of materials such as titanium alloys that are difficult to form at room temperature.

[0008] In summary, although the existing technology has improved the manufacturing process of automobile bridge housings to a certain extent, it still has great limitations when facing high-difficulty materials such as titanium alloys. Especially in the manufacturing of parts with complex structures and high-precision requirements, the existing hydraulic and water expansion forming technologies cannot meet the needs.

[0009] By analyzing the prior art, it can be seen that although the traditional hydraulic bulging and water swelling forming technologies have certain application value in the manufacture of automobile drive axle housings, they have technical limitations when dealing with the needs of high-strength and difficult-to-form materials such as titanium alloys. Especially in the pursuit of high precision, complex shapes and lightweight requirements, these traditional processes are difficult to meet the high standards of modern automobile manufacturing. Therefore, there is an urgent need to develop a new technology that can efficiently form difficult-to-process materials in a vacuum or quasi-vacuum environment to fill the gap in the prior art and promote the further upgrading of automobile manufacturing processes. In this context, the present invention is proposed to provide a new solution for the forming of drive axle housings of difficult materials through hot air bulging forming technology, which has important application value and broad market prospects. Summary of the invention

[0010] According to the technical problems raised above, a device and method for preparing an integral drive axle housing for a truck is provided. The present invention mainly adopts hot air bulging forming technology, and designs a special forming device suitable for vacuum or quasi-vacuum environment, so that it can form metal materials that are difficult to process at room temperature, significantly improves the accuracy and strength of the product, expands the application scope of the forming technology, and optimizes the adaptability and manufacturing cost of the process.

[0011] The technical means adopted by the present invention are as follows:

[0012] A device for preparing an integral drive axle housing for a truck comprises: a heating system, a forming die, an inflation system, a vacuum system and a guide sleeve, wherein a pipe is assembled on the outer wall of the guide sleeve, and the pipe and the guide sleeve are installed in the cavity of the forming die. The heating system is installed on the forming die and is used to heat the pipe; the inflation system is connected to the forming die and the guide sleeve and is used to expand the heated pipe by gas pressure to fill the cavity and form the desired shape of the drive axle housing; the vacuum system is connected to the forming die and the guide sleeve and is used to provide a vacuum or quasi-vacuum environment.

[0013] Furthermore, the molding mold includes a symmetrically arranged lower mold and an upper mold, the lower mold has a first cavity inside, the upper mold has a second cavity inside, the first cavity and the second cavity constitute the cavity, the pipe and the guide sleeve are installed between the lower mold and the upper mold, and the outer walls at both ends of the pipe are in contact with the outer walls at both ends of the lower mold and the upper mold.

[0014] Furthermore, the upper mold and the lower mold are respectively provided with a first air inlet and an air outlet hole and a second air inlet and an air outlet hole connected with the mold cavity for filling and discharging gas; the upper mold and the lower mold are also provided with cooling water channels, and the cooling water channels are connected to an external water supply device;

[0015] The guide sleeve has a channel inside, and the two ends of the channel are a first interface and a second interface. The inflation system is connected to the first interface, the second interface, the first air inlet and exhaust hole and the second air inlet and exhaust hole through a pipeline; the vacuum system is connected to the first interface, the second interface, the first air inlet and exhaust hole and the second air inlet and exhaust hole through a pipeline.

[0016] Furthermore, it also includes a monitoring system for detecting the inflation air pressure and heating temperature, the monitoring system includes multiple pressure testers and multiple thermocouples, at least one pressure tester is arranged on each of the pipelines connecting the first interface, the second interface, the first inlet and exhaust holes, and the second inlet and exhaust holes to the inflation system, and the multiple thermocouples are arranged in the internal channel of the guide sleeve.

[0017] Furthermore, the heating system includes high-temperature electric heating tube I and high-temperature electric heating tube II, and the upper mold and the lower mold of the molding mold are both provided with slots for installing high-temperature electric heating tube I and high-temperature electric heating tube II; the high-temperature electric heating tube I is arranged on both sides of the upper mold and the lower mold, and the high-temperature electric heating tube II is arranged in the middle of the upper mold and the lower mold.

[0018] Furthermore, the high-temperature electric heating tube I includes a plurality of high-temperature electric heating tubes that are closely arranged, and the high-temperature electric heating tube II includes a plurality of high-temperature electric heating tubes that are sparsely arranged.

[0019] Furthermore, it also includes a temperature control system for adjusting the heating temperature, and the high-temperature electric heating tube I and the high-temperature electric heating tube II are connected to the temperature control system, and gradient heating of the pipe is achieved through the temperature control system, wherein the high-temperature electric heating tube I is accelerated heated, and the high-temperature electric heating tube II is slowly heated, and the temperature at both ends of the pipe is greater than the temperature in the middle.

[0020] Furthermore, compensating push sleeves are provided on the outer sides of both ends of the pipe, and the compensating push sleeves are slidably connected to the outer wall of the guide sleeve.

[0021] Furthermore, a plurality of first air flow holes and a plurality of second air flow holes are opened on the middle tube wall of the guide sleeve, and both the first air flow holes and the second air flow holes are connected to the internal channel of the guide sleeve. The plurality of first air flow holes are circumferentially opened on one side of the middle tube wall of the guide sleeve, and the plurality of second air flow holes are circumferentially opened on the other side of the middle tube wall of the guide sleeve.

[0022] The present invention also provides a method for preparing a truck integral drive axle housing preparation device, comprising the following steps:

[0023] Step 1: Material preparation:

[0024] The pipe material shall be seamless pipe or welded pipe, and the smoothness, ovality and straightness of the inner and outer surfaces of the pipe shall meet the requirements; the seamless pipe shall be made of metal seamless pipe, and the welded pipe shall be made of metal welded pipe and homogenized; the pipe shall be assembled on the guide sleeve, and the whole device shall be assembled;

[0025] Step 2: Heating treatment:

[0026] After the pipe is installed in the forming mold, the heating system is started; the heating system consists of high-temperature electric heating tube I and high-temperature electric heating tube II. The high-temperature electric heating tubes are embedded in the lower mold and the upper mold of the forming mold, and the pipe is heated according to the arrangement density of the high-temperature electric heating tubes; the high-temperature electric heating tubes I are arranged densely to accelerate heating, and the high-temperature electric heating tubes II are arranged sparsely to heat slowly; the heating temperature is adjusted by the temperature control system to achieve gradient heating of the pipe, that is, the two ends of the pipe are heated quickly and the temperature is high, and the middle part is heated slowly and the temperature is low, to ensure that the pipe reaches the plastic forming temperature;

[0027] Step 3: Prepare the vacuum environment:

[0028] Start the vacuum system and replace the air inside the molding die by filling it with high-purity argon gas; in the heating state, argon gas flows into the molding die from the first interface and the first inlet and outlet holes respectively, and then is discharged from the second interface and the second inlet and outlet holes, ensuring that the pipe is in a vacuum or quasi-vacuum environment. At this time, the device is in a convection state and there is no pressure in the molding die;

[0029] Step 4: Expansion molding:

[0030] The heating temperature in the forming mold is monitored in real time, and the temperature shows a gradient distribution trend of high at both ends and low in the middle; after reaching the required temperature, the gas expansion system is started, and the first interface and the second interface introduce high-purity argon gas into the guide sleeve to generate uniform gas pressure, and the first air flow hole and the second air flow hole arranged on the guide sleeve are used to realize the trend of the pipe expanding outward; the first air inlet and exhaust hole and the second air inlet and exhaust hole are used to extract the argon gas in the mold cavity outward to assist thermal expansion and rapid forming; at the same time, the compensating push sleeves on both sides are slowly pushed to move to the middle. Since the two ends of the pipe are tightly combined with the lower mold, the upper mold and the guide sleeve, and the material at both ends of the pipe is softened significantly, the end material can only flow to the middle to achieve the purpose of compensating the middle material;

[0031] Step 5: Forming monitoring:

[0032] During the bulging process, the heating temperature is monitored in real time by a thermocouple arranged in the guide sleeve to ensure that the temperature is stable during the forming process; the bulging gas pressure is monitored by pressure test instruments at the first interface, the second interface, the first inlet and outlet holes, and the second inlet and outlet holes to ensure that the gas pressure reaches the set value required by the process;

[0033] Step 6: Cooling and removal:

[0034] After the molding is completed, the heating system and the inflation system are stopped, and the external water supply equipment connects the cooling water channels on the lower and upper molds to gradually reduce the temperature of the molding mold and the seamless pipe / welded pipe and cool them to room temperature; after cooling, the molding mold is opened, and the molded drive axle housing product is taken out to complete the preparation.

[0035] Compared with the prior art, the present invention has the following advantages:

[0036] 1. The present invention adopts hot air bulging forming technology and designs a special forming device suitable for vacuum or quasi-vacuum environment, so that it can form metal materials (such as titanium alloy) that are difficult to process at room temperature, significantly improve the precision and strength of the product, expand the application scope of the forming technology, and optimize the adaptability and manufacturing cost of the process. The present invention can solve the problems of great forming difficulty, low precision, and serious material waste in the prior art, especially for high-strength metal materials such as titanium alloy that are difficult to process at room temperature, through hot air bulging forming technology, the efficient forming and production of the drive axle housing is realized.

[0037] 2. The present invention enables the precise forming of an integral drive axle housing of highly difficult materials such as titanium alloy in a vacuum or quasi-vacuum environment; it can significantly improve the forming accuracy, strength and consistency of the product, while reducing material waste and production costs, and meet the high performance and high quality requirements of modern trucks for drive axle housings.

[0038] 3. The heating system of the present invention can heat the metal material uniformly to ensure that the material reaches the appropriate plastic forming temperature. The use of efficient temperature control technology can maintain temperature stability during the forming process. The heating element adopts a high-temperature electric heating tube. When arranging the high-temperature electric heating tube, the high-temperature electric heating tube is arranged more closely at the I position, so that its energy density is higher and the heating is faster; the high-temperature electric heating tube II is arranged more sparsely, and the mold is heated more slowly. The heating temperature is accurately adjusted by the temperature control system to achieve gradient heating, that is, the two ends of the tube blank are heated quickly and the temperature is high, and the middle part is heated slowly and the temperature is low, ensuring that the seamless tube / welded tube material reaches the appropriate plastic forming temperature. A monitoring system is also provided to detect the expansion air pressure and heating temperature in real time.

[0039] 4. The present invention has inlet and outlet holes respectively opened on the upper and lower molds of the forming mold for argon filling and exhaust. At the same time, cooling water channels are also arranged on the upper and lower molds for cooling the molds and the bridge housing parts after forming.

[0040] 5. The vacuum system of the present invention can remove the air or other gases inside the molding die during the molding process, create a vacuum or quasi-vacuum environment, avoid defects such as oxidation of the material during the molding process, and ensure the high quality of the product. The vacuum system replaces the air inside the molding die by filling high-purity argon gas. When in the heating state, argon gas flows into the molding die from the first interface and the first inlet and outlet holes, respectively, and then is discharged from the second interface and the second inlet and outlet holes, ensuring that the seamless pipe / welded pipe is in a vacuum or quasi-vacuum environment, and the system is in a convection state, and there is no pressure in the molding die, which effectively avoids the generation of defects such as material oxidation during the heating process.

[0041] 6. The pneumatic expansion system of the present invention expands the heated metal material through gas pressure to fill the mold cavity, thereby forming the required shape of the drive axle housing. High-purity argon gas is introduced into the guide sleeve through the first interface and the second interface to generate uniform gas pressure, and the trend of the seamless pipe / welded pipe to expand outward is realized through the first air flow hole and the second air flow hole of the guide sleeve; furthermore, the argon gas in the mold cavity is extracted outward in cooperation with the first air inlet and exhaust hole and the second air inlet and exhaust hole to assist in rapid thermal expansion forming. At the same time, by slowly pushing the compensating push sleeve to move toward the middle, the purpose of compensating the middle material can be achieved, and the problem of obvious thinning of the material in the expansion zone can be effectively avoided.

[0042] 7. The present invention provides a more economical and technically advantageous solution by using welded pipes as raw materials and combining them with hot air bulging forming technology. Welded pipes have obvious economic advantages over welded pipes due to their low manufacturing cost and readily available materials. By homogenizing the welded pipes, removing weld protrusions and ensuring material uniformity, the present invention achieves efficient one-piece forming while avoiding the problems caused by weld treatment in traditional welding processes. Hot air bulging forming technology forms complex structural parts in a vacuum or quasi-vacuum environment, further improving the processing accuracy and molding quality of the products, and meeting the requirements of modern automobile manufacturing for high strength, corrosion resistance and lightweight.

[0043] Based on the above reasons, the present invention can be widely promoted in the fields of automobile manufacturing and the like. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0045] Figure 1 The present invention is a schematic diagram of a device for preparing an integral drive axle housing of a truck.

[0046] Figure 2 It is a molding effect diagram of the present invention.

[0047] Figure 3 Schematic diagram of weld homogenization treatment.

[0048] In the figure: 1. Lower die; 2. High temperature electric heating tube I; 3. High temperature electric heating tube II; 4. Pipe material; 5. Compensating push sleeve; 6. Guide shaft sleeve; 7. Upper die; 8. Thermocouple;

[0049] V1, first interface; V2, second interface; V3, first air flow hole; V4, second air flow hole; B1, first air inlet and exhaust hole; B2, second air inlet and exhaust hole. DETAILED DESCRIPTION

[0050] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments can be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0051] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. The following description of at least one exemplary embodiment is actually only illustrative and is by no means intended to limit the present invention and its application or use. 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.

[0052] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit exemplary embodiments according to the present invention. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprising" and / or "including" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof.

[0053] Unless otherwise specifically stated, the relative arrangement, numerical expressions and numerical values ​​of the parts and steps set forth in these embodiments do not limit the scope of the present invention. Meanwhile, it should be clear that, for ease of description, the sizes of the various parts shown in the accompanying drawings are not drawn according to the actual proportional relationship. The technology, method and equipment known to those of ordinary skill in the relevant art may not be discussed in detail, but in appropriate cases, the technology, method and equipment should be considered as a part of the specification. In all examples shown and discussed here, any specific value should be interpreted as being merely exemplary, rather than as a limitation. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar reference numerals and letters represent similar items in the following drawings, and therefore, once a certain item is defined in an accompanying drawing, it does not need to be further discussed in subsequent drawings.

[0054] In the description of the present invention, it is necessary to understand that the directions or positional relationships indicated by directional words such as "front, back, up, down, left, right", "lateral, vertical, perpendicular, horizontal" and "top, bottom" are usually based on the directions or positional relationships shown in the drawings. They are only for the convenience of describing the present invention and simplifying the description. Unless otherwise specified, these directional words do not indicate or imply that the device or element referred to must have a specific direction or be constructed and operated in a specific direction. Therefore, they cannot be understood as limiting the scope of protection of the present invention: the directional words "inside and outside" refer to the inside and outside relative to the contours of each component itself.

[0055] For ease of description, spatially relative terms such as "above", "above", "on the upper surface of", "above", etc. may be used here to describe the spatial positional relationship between a device or feature and other devices or features as shown in the figure. It should be understood that spatially relative terms are intended to include different orientations of the device in use or operation in addition to the orientation described in the figure. For example, if the device in the accompanying drawings is inverted, the device described as "above other devices or structures" or "above other devices or structures" will be positioned as "below other devices or structures" or "below their position devices or structures". Thus, the exemplary term "above" can include both "above" and "below". The device can also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatially relative descriptions used here are interpreted accordingly.

[0056] In addition, it should be noted that the use of terms such as "first" and "second" to limit components is only for the convenience of distinguishing the corresponding components. If not otherwise stated, the above terms have no special meaning and therefore cannot be understood as limiting the scope of protection of the present invention.

[0057] The present invention provides a device and method for preparing an integral drive axle housing of a truck, and relates to a manufacturing technology of truck parts, and in particular to a forming device for preparing an integral drive axle housing and a related process method. The present invention is mainly used in the field of automobile manufacturing, in particular in the manufacturing of drive axle housings of trucks, and involves technical contents in aspects such as metal forming technology, material processing, and special equipment design. The present invention can solve the problems existing in the prior art such as high forming difficulty, low precision, and serious material waste, and in particular, for high-strength metal materials such as titanium alloys that are difficult to process at room temperature, the efficient forming and production of drive axle housings are achieved through innovative hot air bulging forming technology.

[0058] The main purpose of the present invention is to provide a new hot air bulging forming device and method thereof, which enables the precise forming of an integral drive axle housing of a difficult material such as titanium alloy in a vacuum or quasi-vacuum environment. Through the technical solution of the present invention, the forming accuracy, strength and consistency of the product can be significantly improved, while reducing material waste and production costs, achieving more economical and efficient production, and meeting the high performance and high quality requirements of modern trucks for drive axle housings.

[0059] The present invention can not only use seamless pipes as raw materials, but also use welded pipes to replace seamless pipes as raw materials, and combine with hot air bulging technology, which not only greatly reduces material costs, but also ensures that the performance of welded pipes reaches a level similar to that of seamless pipes through homogenization treatment, thereby achieving efficient forming and precise production of complex structures that are difficult to process at room temperature for high-strength metal materials such as titanium alloys. The present invention is not limited to hot air bulging, and ordinary (non-heated state) bulging bridge shells can also be performed for materials with good plasticity at room temperature (metal materials with elongation ≥ 25%).

[0060] The present invention provides a device for preparing an integral drive axle housing of a truck (such as the attached Figure 1 As shown), the device includes: a heating system, a molding die, an inflation system, a vacuum system and a guide sleeve 6, a pipe 4 (seamless pipe or welded pipe) is assembled on the outer wall of the guide sleeve 6, the pipe 4 and the guide sleeve 6 are installed in the cavity of the molding die, the heating system is installed on the molding die, the inflation system is connected to the molding die and the guide sleeve 6, and the vacuum system is connected to the molding die and the guide sleeve 6.

[0061] Forming mold: Designed to work in a vacuum or quasi-vacuum environment, the mold contains a precision-machined cavity to meet the design shape of the drive axle housing. The mold material has high heat resistance and high strength, and can maintain its shape and function at high temperatures. The forming mold includes an upper mold 7 and a lower mold 1, which are symmetrical in structure. The lower mold 1 has a first cavity inside, and the upper mold 7 has a second cavity inside. The above-mentioned cavity is formed between the first cavity and the second cavity. The pipe 4 and the guide sleeve 6 are installed between the lower mold 1 and the upper mold 7, and the outer walls of the two ends of the pipe 4 are in contact with the outer walls of the two ends of the lower mold 1 and the upper mold 7. The upper mold 7 and the lower mold 1 are both provided with a slot for installing a high-temperature electric heating pipe; in addition, the upper mold 7 and the lower mold 1 are respectively provided with a first inlet and outlet hole B1 and a second inlet and outlet hole B2 connected to the cavity for argon filling and discharge. At the same time, cooling water channels connected to external water supply equipment are arranged on the upper mold 7 and the lower mold 1 to cool the mold and the axle housing parts after forming.

[0062] Heating system: Installed on the forming mold, used to uniformly heat the metal material to ensure that the material reaches the appropriate plastic forming temperature. The heating system adopts efficient temperature control technology, which can maintain temperature stability during the forming process. The heating element is a high-temperature electric heating tube, namely, high-temperature electric heating tube Ⅰ2 and high-temperature electric heating tube Ⅱ3, which are mainly used to heat the forming mold (lower mold 1 and upper mold 7). High-temperature electric heating tube Ⅰ2 and high-temperature electric heating tube Ⅱ3 are embedded in the lower mold 1 and the upper mold 7. High-temperature electric heating tube Ⅰ2 is arranged on both sides of the upper mold 7 and the lower mold 1, and high-temperature electric heating tube Ⅱ3 is arranged in the middle of the upper mold 7 and the lower mold 1. When arranging the high-temperature electric heating tube, the high-temperature electric heating tube Ⅰ2 is arranged more closely (the high-temperature electric heating tube Ⅰ2 includes multiple high-temperature electric heating tubes arranged closely), so that its energy density is higher and heating is faster; the high-temperature electric heating tube Ⅱ3 is arranged more sparsely (the high-temperature electric heating tube Ⅱ3 includes multiple high-temperature electric heating tubes arranged sparsely), and the mold is heated more slowly. High temperature electric heating tubes Ⅰ2 and Ⅱ3 are connected to the temperature control system, and the temperature control system is used to achieve gradient heating of the pipe 4. For materials with good plasticity at room temperature (metal materials with elongation ≥ 25%), the heating system may not be turned on during molding.

[0063] Pneumatic expansion system: The heated metal material is expanded by gas pressure to fill the mold cavity and form the required drive axle housing shape. The guide sleeve 6 has a channel inside, and the two ends of the channel are the first interface V1 and the second interface V2. The pneumatic expansion system connects the four interfaces of the first interface V1, the second interface V2, the first air inlet and exhaust hole B1, and the second air inlet and exhaust hole B2 through pipelines; when the forming mold (lower mold 1 and upper mold 7) and the pipe 4 are heated, in order to ensure that the heating environment of the pipe 4 is a vacuum-like state, the first interface V1, the second interface V2, the first air inlet and exhaust hole B1 and the second air inlet and exhaust hole B2 are all in a convection state, and high-purity argon gas flows in from the first interface V1 and the first air inlet and exhaust hole B1, and then flows out from the second interface V2 and the second air inlet and exhaust hole B2.

[0064] Monitoring system: mainly used to detect inflation gas pressure and heating temperature. The monitoring system includes multiple pressure testers and multiple thermocouples 8, which are arranged in the internal channel of the guide sleeve 6. The inflation gas pressure can be monitored by the pressure test instrument in the pipeline system corresponding to the four interfaces of the first interface V1, the second interface V2, the first air inlet and outlet B1, and the second air inlet and outlet B2; the heating temperature is mainly monitored by the thermocouple 8 arranged in the guide sleeve 6. The thermocouple 8 can be appropriately adjusted according to the different positions of the measuring points, and the number is usually 4 to 6.

[0065] Vacuum system: used to remove air or other gases inside the molding mold during the molding process, create a vacuum or quasi-vacuum environment, avoid defects such as oxidation of the material during the molding process, and ensure the high quality of the product. The present invention adopts the method of filling inert gas (argon) to replace the air in the mold to achieve a quasi-vacuum state. The vacuum system is connected to the first interface V1, the second interface V2, the first air inlet and exhaust hole B1, and the second air inlet and exhaust hole B2 through a pipeline. When the molding mold (lower mold 1 and upper mold 7) and the pipe 4 are heated, the first interface V1 and the second interface V2, the first air inlet and exhaust hole B1 and the second air inlet and exhaust hole B2 are in a convection state, and high-purity argon flows in from the first interface V1 and the first air inlet and exhaust hole B1, respectively, and then flows out from the second interface V2 and the second air inlet and exhaust hole B2, which can ensure that the heating environment of the pipe 4 is in a quasi-vacuum state.

[0066] The remaining parts: the compensating push sleeve 5 is arranged outside the two ends of the pipe 4 and is slidably connected to the outer wall of the guide sleeve 6. It is mainly used to push the end material of the pipe 4 to flow to the middle part, so as to compensate for the thinning of the material wall thickness during molding. During molding, the two ends P1 and P2 of the compensating push sleeve 5 need to act simultaneously; the guide sleeve 6 is mainly used to install the pipe 4 and the compensating push sleeve 5. There are multiple groups of first airflow holes V3 and second airflow holes V4 in the middle part, which are used to divert the argon gas filled in V1 and V2 to deform the pipe 4. The first airflow holes V3 and the second airflow holes V4 are both connected to the internal channel of the guide sleeve 6. Multiple first airflow holes V3 are circumferentially opened on one side of the middle pipe wall of the guide sleeve 6, and multiple second airflow holes V4 are circumferentially opened on the other side of the middle pipe wall of the guide sleeve 6.

[0067] Seamless pipe is a metal seamless pipe, and its inner and outer surfaces need to maintain a certain degree of smoothness, ovality and straightness.

[0068] Welded pipe is a metal welded pipe, usually formed by roll bending or rolling by a pipe rolling machine, and then welded by high frequency welding or argon arc welding. Figure 3 As shown in the figure, the welded pipe needs to be homogenized before hot air bulging the bridge shell. The welded pipe after homogenization treatment requires that its inner and outer surfaces must maintain a certain degree of smoothness, ovality and straightness. Homogenization treatment includes: (1) Smoothing treatment of welded pipe welds, that is, using mechanical methods such as scraping and grinding to remove the material from the protruding parts of the welded pipe welds. (2) Homogenization treatment of welded pipe welds, that is, using heat treatment + ultrasonic impact and other process methods to achieve the purpose of removing residual stress in the weld and homogenizing the microstructure, so as to achieve the homogenization of the weld and the parent material.

[0069] In addition, in order to realize the preparation of a drive axle housing by the device of the present invention, the preparation method mainly includes the following steps:

[0070] 1. Material preparation:

[0071] Select metal seamless pipes or metal welded pipes that meet the requirements, and ensure that the smoothness, ovality and straightness of the inner and outer surfaces meet the requirements. The metal welded pipes are homogenized. Assemble the pipes onto the guide sleeve 6, and assemble the remaining parts as shown in the attached figure;

[0072] 2.Heat treatment:

[0073] After installing the pipe 4 (seamless pipe or welded pipe after homogenization treatment) into the forming mold, start the heating system. The heating system consists of high-temperature electric heating pipe Ⅰ2 and high-temperature electric heating pipe Ⅱ3, which are embedded in the forming mold (lower mold 1 and upper mold 7) to heat the pipe 4 according to the designed layout density. The high-temperature electric heating pipe Ⅰ2 is densely arranged to accelerate heating, and the high-temperature electric heating pipe Ⅱ3 is sparsely arranged to heat slowly. The heating temperature is precisely adjusted by the temperature control system to achieve gradient heating of the pipe 4 (that is, the two ends of the pipe blank are heated quickly and the temperature is high, and the middle part is heated slowly and the temperature is low), ensuring that the seamless pipe or welded pipe material reaches the appropriate plastic forming temperature.

[0074] 3. Vacuum environment preparation:

[0075] Start the vacuum system and replace the air inside the molding die by filling it with high-purity argon. In the heating state, argon flows into the molding die from the first interface V1 and the first inlet and outlet holes B1 respectively, and then is discharged from the second interface V2 and the second inlet and outlet holes B2, ensuring that the tube 4 is in a vacuum or quasi-vacuum environment. At this time, the system is in a convection state and there is no pressure in the molding die. This step effectively avoids the occurrence of defects such as material oxidation during the heating process.

[0076] 4. Bulging molding:

[0077] The heating temperature in the forming mold is monitored in real time, showing a gradient distribution trend with high temperatures at both ends and low temperatures in the middle. After reaching the required temperature, the inflation system is started, and high-purity argon gas is introduced into the guide sleeve 6 through the first interface V1 and the second interface V2 to generate uniform gas pressure, and the first air flow hole V3 and the second air flow hole V4 arranged on the guide sleeve 6 are used to realize the trend of the tube 4 expanding outward. Furthermore, the argon gas in the mold cavity is extracted outwardly in cooperation with the first air inlet and exhaust hole B1 and the second air inlet and exhaust hole B2 to assist in rapid thermal expansion forming. At the same time, the P1 and P2 ends of the compensating push sleeve 5 are slowly pushed toward the middle. Since the two ends of the tube 4 are tightly combined with the forming mold (lower mold 1 and upper mold 7) and the guide sleeve 6, and the material at both ends is softened significantly, the end material can only flow toward the middle to achieve the purpose of compensating the middle material, effectively avoiding the problem of obvious thinning of the material in the bulging area.

[0078] 5. Molding monitoring:

[0079] During the bulging process, the heating temperature is monitored in real time by the thermocouple 8 arranged in the guide sleeve 6 to ensure the temperature stability during the forming process. The bulging gas pressure is monitored by the pressure test instruments at the four interfaces of the first interface V1, the second interface V2, the first inlet and outlet holes B1, and the second inlet and outlet holes B2 to ensure that the gas pressure reaches the set value required by the process and ensure the stability and accuracy of the forming process.

[0080] 6. Cooling and removal:

[0081] After the molding is completed, the heating system and the inflation system are stopped, and the cooling water channel on the molding mold (lower mold 1 and upper mold 7) is connected to gradually reduce the temperature of the molding mold and the pipe 4 to cool it to room temperature. After the cooling is completed, the mold is opened, and the molded drive axle housing product is taken out to complete the preparation.

[0082] Through the above steps, the method of the present invention can accurately manufacture a high-quality integral drive axle housing by using hot air bulging forming technology in a vacuum or quasi-vacuum environment, which is particularly suitable for processing materials that are difficult to form at room temperature, such as titanium alloys, and meets the needs of modern trucks for high-performance parts. The present invention not only provides a new solution for the molding of drive axle housings of difficult materials through hot air bulging forming technology, but also can make full use of the cost advantage of welded pipes, and has important application value and broad market prospects.

[0083] The invention discloses a device and method for preparing an integral drive axle housing for a truck, which adopts advanced hot air bulging forming technology. In addition to conventional metal material forming, it can also be used to form metal materials that are difficult to form at room temperature, such as titanium alloys. This technology has significant advantages, especially in the field of truck manufacturing, and plays an important role in improving production efficiency, reducing material loss, and improving product quality.

[0084] In addition, another outstanding feature of the present invention is that the raw material can be not only seamless pipes but also welded pipes for preparing the bridge housing. The present invention uses welded pipes as the basic material, the manufacturing cost of welded pipes is lower, and the market supply is more sufficient. Through homogenization treatment, the welded pipe can eliminate the material inhomogeneity and stress concentration problems in the weld area, so that the mechanical properties after forming can reach a level similar to that of seamless pipes, ensuring the reliability of the finished product under high load conditions.

[0085] In China, with the continuous upgrading of the automobile industry, the demand for high-strength and lightweight automobile parts is growing. The traditional drive axle housing manufacturing process can no longer meet the market demand for complex shapes, high precision, and high-strength products, and a new molding method that can break through the technical bottleneck is urgently needed. The promotion and application of the present invention can effectively solve the shortcomings of the existing manufacturing process, especially meet the truck industry's demand for high-strength, lightweight, and complex-shaped integrated molding of drive axle housings. Therefore, the present invention has broad application prospects in the domestic market and can be quickly promoted to large automobile manufacturers to enhance their product competitiveness.

[0086] In the international market, as the world's attention to environmental protection and energy conservation and emission reduction continues to increase, automobile manufacturers are actively seeking new technologies to reduce carbon emissions and improve fuel efficiency. The hot air bulging forming technology used in the present invention can achieve lightweight and efficient production of materials while ensuring the strength and quality of parts, which is in line with the development trend of the global automobile manufacturing industry.

[0087] Titanium alloy and other difficult-to-form materials are widely used, especially in developed countries such as Europe, America and Japan, where the automotive industry has an urgent need for high-strength and lightweight materials. The special forming device and method designed by the present invention can efficiently form these difficult-to-process materials in a vacuum or quasi-vacuum environment, and has strong technical competitiveness and market appeal.

[0088] From the perspective of technology promotion, the present invention has high replicability and applicability. First of all, hot air bulging forming technology has been preliminarily applied in many fields and has proved its reliability and advancement. On this basis, the present invention designs a special forming device to enable it to adapt to the production needs of different types of drive axle housings and has wide applicability. Secondly, with the improvement of the technological level of my country's manufacturing industry, the acceptance of new technologies by major automobile manufacturers is also constantly increasing, which provides a strong guarantee for the promotion of the present invention. The present invention also uses more economical welded pipes as raw materials, and through homogenization treatment and one-piece molding technology, it significantly reduces the production cost, while ensuring the high quality and consistency of the drive axle housing. This technology not only meets the domestic market's demand for cost-effective automotive parts, but also has the potential for promotion in the international market, especially in emerging economies. With its cost advantage and technological advancement, the present invention has good market competitiveness and broad application prospects, and is suitable for large-scale promotion.

[0089] After the promotion and application of the present invention, it can not only significantly improve production efficiency and reduce manufacturing costs, but also bring considerable economic benefits to enterprises. Especially in the field of automobile manufacturing, the application of this technology can effectively reduce material waste, increase the added value of products, and thus enhance the market competitiveness of enterprises. At the same time, the present invention also has significant social benefits. By promoting the application of new technologies for high efficiency and energy saving, energy consumption and carbon emissions in the manufacturing process can be reduced, and the realization of the concept of green manufacturing can be promoted, which is in line with the sustainable development goals currently advocated by the world. The present invention significantly reduces production costs, improves production efficiency, achieves product consistency and high quality, and has significant economic benefits by adopting welded pipe materials and efficient one-piece molding processes. At the same time, it reduces resource consumption and manufacturing costs, meets the requirements of sustainable development, promotes technological upgrading and industrial optimization of the automobile manufacturing industry, promotes the healthy development of the social economy, and shows good social benefits.

[0090] In summary, the device and method for preparing an integral drive axle housing for a truck of the present invention have high feasibility for promotion and application and broad market prospects.

[0091] Example 1

[0092] The present invention is used to prepare a high-strength steel drive axle housing.

[0093] Material: DP980 high-strength dual-phase seamless steel pipe is used. This material has high strength, good high-temperature ductility and fatigue resistance, and is widely used in the automotive manufacturing field. The yield strength of DP980 is about 980MPa and the tensile strength is about 1000MPa.

[0094] Process: The method for preparing the integral drive axle housing of the present invention is adopted, and the specific steps are as follows:

[0095] 1. Material preparation: Assemble the DP980 seamless pipe onto the guide sleeve 6 and assemble it with other components according to the design requirements.

[0096] 2. Heating treatment: Start the heating system and use high-temperature electric heating tubes to perform gradient heating on the seamless pipe. The temperature at both ends of the pipe blank is set to 800℃, and the temperature in the middle is set to 700℃ to ensure that the material reaches the plastic forming temperature.

[0097] 3. Vacuum environment preparation: Use high-purity argon gas to replace the air inside the mold to maintain a vacuum state and avoid oxidation.

[0098] 4. Expansion molding: Under the action of the gas expansion system, high-purity argon gas is uniformly expanded through the first gas flow hole V3 and the second gas flow hole V4 in the guide sleeve to push the P1 and P2 ends of the compensation push sleeve 5 to ensure uniform material flow and avoid thinning problems.

[0099] 5. Molding monitoring: Real-time monitoring of molding temperature and air pressure to ensure a stable molding process.

[0100] 6. Cooling and removal: After molding is completed, the temperature is lowered through the cooling water channel, and finally the molded DP980 integral drive axle housing is taken out.

[0101] Results: The DP980 integral drive axle housing prepared by this process has the characteristics of high strength and high precision, uniform wall thickness, no obvious thinning area, good surface finish, and better structural integrity than traditional processes.

[0102] Comparative Example 1

[0103] The high-strength steel drive axle housing is manufactured using traditional technology.

[0104] Material: DP980 steel plate.

[0105] Process: The drive axle housing is prepared using the traditional stamping + welding process. The specific steps are as follows:

[0106] 1. Stamping: After cutting the DP980 steel plate, use a stamping machine to stamp the material in multiple steps to form the various parts of the bridge housing.

[0107] 2. Welding: Use welding equipment to weld the various stamped parts together to form an integral bridge shell.

[0108] 3. Heat treatment: In order to eliminate welding stress, the bridge housing is subjected to overall heat treatment after welding.

[0109] Results: Although the bridge shell prepared by stamping + welding process can meet the basic requirements in terms of strength, the overall consistency of the product is poor due to the change of material properties in the welding area, there is a potential risk of fatigue cracks at the weld, and the deformation caused by the welding process reduces the dimensional accuracy of the product.

[0110] Example 2

[0111] The present invention is used to prepare a titanium alloy drive axle housing.

[0112] Material: TC4 titanium alloy seamless pipe is selected. TC4 titanium alloy has high specific strength, good corrosion resistance and excellent welding performance. The yield strength of TC4 is about 900MPa and the tensile strength is about 950MPa.

[0113] Process: The method for preparing the integral drive axle housing of the present invention is adopted, and the specific steps are as follows:

[0114] 1. Material preparation: Assemble the TC4 titanium alloy seamless pipe onto the guide sleeve 6 and assemble it with other components according to the design requirements.

[0115] 2. Heating treatment: Start the heating system and perform gradient heating on the TC4 titanium alloy seamless tube. The temperature at both ends of the tube is set to 850°C and the temperature in the middle is set to 750°C to ensure that the material reaches the plastic forming temperature.

[0116] 3. Vacuum environment preparation: Use high-purity argon gas to replace the air inside the mold to maintain a vacuum state and avoid oxidation.

[0117] 4. Bulging forming: Under the action of the gas expansion system, the TC4 titanium alloy seamless pipe achieves uniform bulging forming, and the compensating push sleeve 5 ensures uniform material flow.

[0118] 5. Molding monitoring: Real-time monitoring of molding temperature and air pressure to ensure a stable molding process.

[0119] 6. Cooling and removal: After the molding is completed, the temperature is lowered through the cooling water channel, and finally the formed TC4 titanium alloy integral drive axle housing is taken out.

[0120] Results: The TC4 titanium alloy integral drive axle housing produced by this process has stable product performance and high structural strength, and is particularly suitable for applications that require high strength, light weight, and corrosion resistance. Compared with traditional processes, the consistency and fatigue resistance of the product are significantly improved.

[0121] Comparative Example 2

[0122] The titanium alloy drive axle housing is manufactured using traditional technology.

[0123] Material: TC4 titanium alloy plate.

[0124] Process: The drive axle housing is prepared using the traditional stamping + welding process. The specific steps are as follows:

[0125] 1. Stamping: After cutting the TC4 titanium alloy sheet, use a stamping machine to perform multiple steps on the material to form various parts of the bridge housing.

[0126] 2. Welding: Use welding equipment to weld the various stamped parts together to form an integral bridge shell.

[0127] 3. Heat treatment: In order to eliminate welding stress, the bridge housing is subjected to overall heat treatment after welding.

[0128] Results: The TC4 titanium alloy bridge shell prepared by stamping + welding process has good overall strength, but the performance of the welding area is obviously degraded, and the corrosion resistance and fatigue strength of the weld are significantly reduced. Since titanium alloy has high requirements for welding process and large welding deformation, the product precision and surface quality are poor.

[0129] Comparative results analysis:

[0130] By comparing the above embodiments with the comparative examples (Example 1, Example 2, Comparative Example 1, Comparative Example 2), the superiority of the method for preparing the integral drive axle housing of the present invention can be clearly seen.

[0131]

[0132]

[0133] From the above comparison, it can be seen that the overall forming technology of the present invention, whether it is DP980 steel or TC4 titanium alloy, shows better performance than the traditional stamping + welding process. In particular, in terms of key indicators such as mechanical properties, structural stability, production efficiency and manufacturing cost, the overall forming process of the present invention has significant advantages, and the production process is simplified, the production efficiency is improved, and it is suitable for large-scale, high-quality drive axle housing manufacturing, and has broad application prospects and market competitiveness.

[0134] Example 3

[0135] The present invention is used to prepare a high-strength steel drive axle housing.

[0136] Materials: DP980 dual-phase steel plate is roll-bent to prepare high-frequency welded pipes. The welded pipe is cut into the required length, and a mechanical scraper is used to remove the excess material protruding from the weld on the welded pipe; ultrasonic impact (stress relief) + normalizing (structure refinement) process is used to homogenize the weld, namely:

[0137]

[0138]

[0139] This material has high strength, good high temperature ductility and fatigue resistance, and is widely used in the automotive manufacturing field.

[0140] Process: The preparation method (integrated drive axle housing preparation method) of the present invention is adopted, and the specific steps are as follows:

[0141] 1. Material preparation: Assemble the DP980 homogenized welded pipe onto the guide sleeve 6 and assemble it with other components according to the design requirements.

[0142] 2. Heating treatment: Start the heating system and use high-temperature electric heating tubes to perform gradient heating on the welded pipe. The temperature at both ends of the pipe blank is set to 800℃, and the temperature in the middle is set to 700℃ to ensure that the material reaches the plastic forming temperature.

[0143] 3. Vacuum environment preparation: Use high-purity argon gas to replace the air inside the mold to maintain a vacuum state and avoid oxidation.

[0144] 4. Expansion molding: Under the action of the gas expansion system, high-purity argon gas is uniformly expanded through the first gas flow hole V3 and the second gas flow hole V4 in the guide sleeve to push the P1 and P2 ends of the compensation push sleeve 5 to ensure uniform material flow and avoid thinning problems.

[0145] 5. Molding monitoring: Real-time monitoring of molding temperature and air pressure to ensure a stable molding process.

[0146] 6. Cooling and removal: After molding is completed, the temperature is lowered through the cooling water channel, and finally the molded DP980 integrated drive axle housing is taken out.

[0147] Results: The DP980 integrated drive axle housing prepared by this process has the characteristics of high strength and high precision, uniform wall thickness, no obvious thinning area, good surface finish, and better structural integrity than traditional processes.

[0148] Comparative Example 3

[0149] The high-strength steel drive axle housing is manufactured using traditional technology.

[0150] Material: DP980 steel plate.

[0151] Process: The drive axle housing is prepared using the traditional stamping + welding process. The specific steps are as follows:

[0152] 1. Stamping: After cutting the DP980 steel plate, use a stamping machine to stamp the material in multiple steps to form the various parts of the bridge housing.

[0153] 2. Welding: Use welding equipment to weld the various stamped parts together to form an integrated bridge shell.

[0154] 3. Heat treatment: In order to eliminate welding stress, the welded bridge shell is subjected to integrated heat treatment.

[0155] Results: Although the bridge shell prepared by stamping + welding process can meet the basic requirements in terms of strength, the product has poor consistency due to the change of material properties in the welding area, there is a potential risk of fatigue cracks at the weld, and the deformation caused by the welding process reduces the dimensional accuracy of the product.

[0156] Example 4

[0157] The present invention is used to prepare a titanium alloy drive axle housing.

[0158] Material: TC4 titanium alloy sheet is used for hot roll bending to prepare welded pipes, and the welding method is argon arc welding. TC4 titanium alloy has high specific strength, good corrosion resistance and excellent welding performance. The welded pipe is cut into the required length, and the excess material protruding from the weld on the welded pipe is removed by a mechanical scraper; the weld is homogenized by ultrasonic impact (stress relief) + normalizing (structure refinement), that is:

[0159]

[0160] Process: The integrated drive axle housing preparation method of the present invention is adopted, and the specific steps are as follows:

[0161] 1. Material preparation: Assemble the TC4 titanium alloy welded pipe onto the guide sleeve 6 and assemble it with other components according to the design requirements.

[0162] 2. Heating treatment: Start the heating system to perform gradient heating on the TC4 titanium alloy welded pipe. The temperature at both ends of the pipe blank is set to 850°C, and the temperature in the middle is set to 750°C to ensure that the material reaches the plastic forming temperature.

[0163] 3. Vacuum environment preparation: Use high-purity argon gas to replace the air inside the mold to maintain a vacuum state and avoid oxidation.

[0164] 4. Bulging forming: Under the action of the gas expansion system, the TC4 titanium alloy welded pipe achieves uniform bulging forming, and the compensating push sleeve ensures uniform material flow.

[0165] 5. Molding monitoring: Real-time monitoring of molding temperature and air pressure to ensure a stable molding process.

[0166] 6. Cooling and removal: After the molding is completed, the temperature is lowered through the cooling water channel, and finally the formed TC4 titanium alloy integrated drive axle housing is taken out.

[0167] Results: The TC4 titanium alloy one-piece drive axle housing produced by this process has stable product performance and high structural strength, and is particularly suitable for applications that require high strength, light weight, and corrosion resistance. Compared with traditional processes, the consistency and fatigue resistance of the product are significantly improved.

[0168] Comparative Example 4

[0169] The titanium alloy drive axle housing is manufactured using traditional technology.

[0170] Material: TC4 titanium alloy plate.

[0171] Process: The drive axle housing is prepared using the traditional stamping + welding process. The specific steps are as follows:

[0172] 1. Stamping: After cutting the TC4 titanium alloy sheet, use a stamping machine to perform multiple steps on the material to form various parts of the bridge housing.

[0173] 2. Welding: Use welding equipment to weld the various stamped parts together to form an integrated bridge shell.

[0174] 3. Heat treatment: In order to eliminate welding stress, the welded bridge shell is subjected to integrated heat treatment.

[0175] Results: The TC4 titanium alloy bridge shell produced by stamping + welding process has good strength, but the performance of the welding area is obviously degraded, and the corrosion resistance and fatigue strength of the weld are significantly reduced. Since titanium alloy has high requirements for welding process and large welding deformation, the product precision and surface quality are poor.

[0176] Comparative results analysis:

[0177] By comparing the above embodiments with the comparative examples (Example 3, Example 4, Comparative Example 3, Comparative Example 4), the superiority of the preparation method of the present invention can be clearly seen:

[0178]

[0179] From the above comparison, it can be seen that the molding technology of the present invention, whether it is DP980 steel or TC4 titanium alloy, shows better performance than the traditional stamping + welding process. In particular, in terms of key indicators such as mechanical properties, structural stability, production efficiency and manufacturing cost, the molding process of the present invention has significant advantages, and the production process is simplified, the production efficiency is improved, and it is suitable for large-scale, high-quality drive axle housing manufacturing, and has broad application prospects and market competitiveness.

[0180] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A device for preparing an integral drive axle housing of a truck, characterized in that: include: A heating system, a molding die, an air expansion system, a vacuum system and a guide sleeve (6); a pipe (4) is mounted on the outer wall of the guide sleeve (6); the pipe (4) and the guide sleeve (6) are mounted in a mold cavity of the molding die; the heating system is mounted on the molding die and is used to heat the pipe (4); the air expansion system is connected to the molding die and the guide sleeve (6) and is used to expand the heated pipe (4) through gas pressure to fill the mold cavity and form the desired drive axle housing shape; the vacuum system is connected to the molding die and the guide sleeve (6) and is used to provide a vacuum or quasi-vacuum environment.

2. The truck integral drive axle housing preparation device according to claim 1, characterized in that: The molding die comprises a symmetrically arranged lower die (1) and an upper die (7), the lower die (1) having a first cavity inside, the upper die (7) having a second cavity inside, the first cavity and the second cavity forming the cavity, the pipe (4) and the guide sleeve (6) being installed between the lower die (1) and the upper die (7), and the outer walls at both ends of the pipe (4) being in contact with the outer walls at both ends of the lower die (1) and the upper die (7).

3. The truck integral drive axle housing preparation device according to claim 2, characterized in that: The upper mold (7) and the lower mold (1) are respectively provided with a first air inlet and outlet hole (B1) and a second air inlet and outlet hole (B2) which are connected to the mold cavity and are used for filling and discharging gas; the upper mold (7) and the lower mold (1) are also provided with cooling water channels which are connected to an external water supply device; The guide sleeve (6) has a channel inside, and the two ends of the channel are a first interface (V1) and a second interface (V2); the inflation system is connected to the first interface (V1), the second interface (V2), the first air inlet and outlet hole (B1) and the second air inlet and outlet hole (B2) through a pipeline; the vacuum system is connected to the first interface (V1), the second interface (V2), the first air inlet and outlet hole (B1) and the second air inlet and outlet hole (B2) through a pipeline.

4. The truck integral drive axle housing preparation device according to claim 3, characterized in that: The invention also comprises a monitoring system for detecting inflation air pressure and heating temperature, the monitoring system comprising a plurality of pressure testers and a plurality of thermocouples (8), at least one pressure tester is respectively arranged on the pipelines connecting the first interface (V1), the second interface (V2), the first air inlet and outlet hole (B1) and the second air inlet and outlet hole (B2) with the inflation system, and the plurality of thermocouples (8) are arranged in the internal channel of the guide sleeve (6).

5. The truck integral drive axle housing preparation device according to claim 1, characterized in that: The heating system comprises a high-temperature electric heating tube I (2) and a high-temperature electric heating tube II (3); the upper mold (7) and the lower mold (1) of the molding mold are both provided with slots for installing the high-temperature electric heating tube I (2) and the high-temperature electric heating tube II (3); the high-temperature electric heating tube I (2) is arranged on both sides of the upper mold (7) and the lower mold (1), and the high-temperature electric heating tube II (3) is arranged in the middle of the upper mold (7) and the lower mold (1).

6. The truck integral drive axle housing preparation device according to claim 5, characterized in that: The high-temperature electric heating tube I (2) includes a plurality of high-temperature electric heating tubes that are closely arranged, and the high-temperature electric heating tube II (3) includes a plurality of high-temperature electric heating tubes that are sparsely arranged.

7. The truck integral drive axle housing preparation device according to claim 5 or 6, characterized in that: The invention also comprises a temperature control system for adjusting the heating temperature, wherein the high temperature electric heating tube I (2) and the high temperature electric heating tube II (3) are connected to the temperature control system, and gradient heating of the pipe (4) is achieved through the temperature control system, wherein the high temperature electric heating tube I (2) is subjected to accelerated heating, and the high temperature electric heating tube II (3) is subjected to slow heating, and the temperature at both ends of the pipe (4) is greater than the temperature in the middle.

8. The device for preparing an integral drive axle housing for a truck according to claim 1, characterized in that: Compensating push sleeves (5) are provided on the outer sides of both ends of the pipe (4), and the compensating push sleeves (5) are slidably connected to the outer wall of the guide shaft sleeve (6).

9. The truck integral drive axle housing preparation device according to claim 1, characterized in that: A plurality of first air flow holes (V3) and a plurality of second air flow holes (V4) are provided on the middle tube wall of the guide sleeve (6); the first air flow holes (V3) and the second air flow holes (V4) are both connected to the internal channel of the guide sleeve (6); the plurality of first air flow holes (V3) are circumferentially provided on one side of the middle tube wall of the guide sleeve (6); and the plurality of second air flow holes (V4) are circumferentially provided on the other side of the middle tube wall of the guide sleeve (6).

10. A method for preparing a truck integral drive axle housing according to any one of claims 1 to 9, characterized in that: The steps include: Step 1: Material preparation: The pipe (4) is a seamless pipe or a welded pipe, and the smoothness, ovality and straightness of the inner and outer surfaces of the pipe (4) are ensured to meet the requirements; the seamless pipe is a metal seamless pipe, and the welded pipe is a metal welded pipe and is homogenized; the pipe (4) is assembled onto the guide sleeve (6), and the entire device is assembled; Step 2: Heating treatment: After the pipe (4) is installed in the forming mold, the heating system is started; the heating system is composed of a high-temperature electric heating tube I (2) and a high-temperature electric heating tube II (3), and the high-temperature electric heating tube is embedded in the lower mold (1) and the upper mold (7) of the forming mold, and the pipe (4) is heated according to the arrangement density of the high-temperature electric heating tube; wherein the high-temperature electric heating tube I (2) is arranged more densely to accelerate the heating, and the high-temperature electric heating tube II (3) is arranged more sparsely to heat slowly; the heating temperature is adjusted by the temperature control system, so that the pipe (4) is heated in a gradient manner, that is, the two ends of the pipe (4) are heated quickly and the temperature is high, and the middle part is heated slowly and the temperature is low, so as to ensure that the pipe (4) reaches the plastic forming temperature; Step 3: Prepare the vacuum environment: The vacuum system is started, and the air inside the molding die is replaced by filling with high-purity argon gas; in the heating state, the argon gas flows into the molding die from the first interface (V1) and the first inlet and outlet holes (B1), and then is discharged from the second interface (V2) and the second inlet and outlet holes (B2), ensuring that the pipe (4) is in a vacuum or quasi-vacuum environment. At this time, the device is in a convection state, and there is no pressure in the molding die; Step 4: Expansion molding: The heating temperature in the molding die is monitored in real time, and the temperature shows a gradient distribution trend of being high at both ends and low in the middle; after reaching the required temperature, the inflation system is started, and the first interface (V1) and the second interface (V2) introduce high-purity argon gas into the guide sleeve (6) to generate uniform gas pressure, and the first air flow hole (V3) and the second air flow hole (V4) arranged on the guide sleeve (6) are used to realize the trend of the pipe (4) expanding outward; the first air inlet and outlet holes (B1) and the second air inlet and outlet holes (B2) are used to extract argon gas in the mold cavity outward to assist thermal expansion and rapid molding; at the same time, the compensating push sleeves (5) on both sides are slowly pushed to move toward the middle. Since the two ends of the pipe (4) are tightly combined with the lower mold (1) and the upper mold (7) as well as the guide sleeve (6), and the material at the two ends of the pipe (4) is obviously softened, the end material can only flow toward the middle to achieve the purpose of compensating the middle material; Step 5: Forming monitoring: During the bulging process, the heating temperature is monitored in real time by a thermocouple (8) arranged in the guide sleeve (6) to ensure that the temperature is stable during the forming process; the bulging gas pressure is monitored by pressure test instruments at the first interface (V1), the second interface (V2), the first inlet and outlet holes (B1), and the second inlet and outlet holes (B2) to ensure that the gas pressure reaches the set value required by the process; Step 6: Cooling and removal: After the molding is completed, the heating system and the inflation system are stopped, and the external water supply equipment is connected to the cooling water channels on the lower mold (1) and the upper mold (7), so as to gradually reduce the temperature of the molding mold and the pipe (4) and cool them to room temperature; after the cooling is completed, the molding mold is opened, and the molded drive axle housing product is taken out to complete the preparation.

Images