Forming method of integral axle housing of automobile drive axle

Abstract

The invention relates to the technical field of automobile parts, in particular to a forming method of an integral axle housing of an automobile drive axle, which comprises the following steps: acquiring a high-strength steel plate, pretreating, and performing laser cutting blanking to obtain an axle housing blank; setting equipment stamping parameters, lubricating and preheating the die, and placing the axle housing blank in the die; according to the method, more than four traditional stamping procedures and follow-up auxiliary procedures are replaced by a one-step forming process, the production time is shortened by 70%, the production efficiency is greatly improved, the batch production requirement is met, multi-procedure accumulative errors are avoided through one-time stamping forming, the production cost is reduced, and the production efficiency is improved. Key precision indexes such as flange planeness and longitudinal seam straightness of a product meet strict requirements, a segmented welding structure is avoided, welding thermal deformation and stress concentration are avoided, the welding matching performance is greatly improved, and the overall quality stability of the product is enhanced.

Description

Technical Field

[0001] This invention relates to the field of automotive parts manufacturing technology, and in particular to a method for forming an integral axle housing for an automotive drive axle. Background Technology

[0002] As the core load-bearing and protective component of the drive axle, the integral axle housing of the automotive drive axle must simultaneously meet multiple functions such as supporting the weight of the vehicle, transmitting road reaction force and torque, housing transmission components such as the main reducer / differential, and ensuring driving safety. The development of its molding process has always revolved around the three core requirements of "performance improvement, lightweighting, and cost optimization".

[0003] In the traditional manufacturing process of automotive drive axle housings, multiple steps are usually required, including blanking, forming, cutting straight edges, cutting round edges, cutting ends, and shaping. This process is not only complex and cumbersome, but also results in low production efficiency. Summary of the Invention

[0004] The purpose of this invention is to provide a molding method for an integral axle housing of an automobile drive axle, which aims to solve the problems of complex and cumbersome processes and low production efficiency in traditional automobile drive axle housing molding processes.

[0005] To achieve the above objectives, the present invention provides a method for molding an integral axle housing for an automobile drive axle, comprising the following steps: High-strength steel plates are obtained, pretreated, and laser-cut to obtain bridge shell blanks; Set the equipment stamping parameters, lubricate and preheat the mold, and place the bridge shell blank in the mold; The equipment stamps the bridge housing blank, holds the pressure, opens the mold to remove the whole bridge housing, and inspects the whole bridge housing.

[0006] The specific method for obtaining high-strength steel plates, pre-processing them, and laser cutting them to obtain bridge shell blanks is as follows: High-strength steel plates are obtained, their surfaces are cleaned and leveled to obtain raw steel plate material; Based on the billet size, the steel plate raw material is laser-cut to obtain the bridge shell billet.

[0007] The specific methods for setting the stamping parameters of the equipment, lubricating and preheating the mold, and placing the bridge shell blank in the mold are as follows: Set the stamping parameters of the equipment, preheat the mold to the preset temperature, and spray lubricant onto the mold for lubrication; The bridge shell blank is placed in a mold.

[0008] The stamping parameters include a main cylinder pressure of 6 MPa, a holding time of 10-12 seconds, a top cylinder upper limit of 150 mm, and a preset temperature of 50-60℃.

[0009] The lubricant is designated as KL-800 with a viscosity of 20-30 mm. 2 / s, with a coating thickness of 5-8μm.

[0010] The specific methods for the equipment to stamp the bridge housing blank, hold pressure, open the mold to remove the integral bridge housing, and inspect the integral bridge housing are as follows: The equipment stamps the bridge housing blank, holds the pressure, and then opens the mold to remove the complete bridge housing. Compressed air is used to blow away residual lubricant and metal debris from the surface of the integral bridge housing. The overall bridge housing quality is inspected, defective products are removed, and the finished overall bridge housing is obtained.

[0011] The flatness of the flange of the integral bridge shell method is ≤0.5mm, and the straightness of the longitudinal joint is ≤1mm.

[0012] This invention discloses a method for forming an integral axle housing for an automotive drive axle. The method involves obtaining a high-strength steel plate, pre-treating it, and laser-cutting it to obtain axle housing blank. The equipment stamping parameters are set, the mold is lubricated and preheated, and the axle housing blank is placed in the mold. The equipment stamps the axle housing blank, holds the pressure, opens the mold, removes the integral axle housing, and inspects the integral axle housing. This method replaces the traditional four or more stamping processes and subsequent auxiliary processes with a single-stage forming process, reducing production time by 70%, significantly improving production efficiency, meeting the needs of mass production, and avoiding the accumulation of errors from multiple processes. Key precision indicators such as flange flatness and longitudinal seam straightness meet strict requirements, welding compatibility is greatly improved, and the overall quality stability of the product is enhanced. This solves the problems of complex and cumbersome processes and low production efficiency in traditional automotive drive axle housing forming processes. Attached Figure Description

[0013] To make the technical solution and advantages of this application clearer, the embodiments of this application will be described in further detail below.

[0014] The terms "first," "second," "third," and "fourth," etc., used in the specification, claims, and accompanying drawings of this application are used to distinguish different objects, not to describe a specific order. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or apparatus that includes a series of steps or units is not limited to the listed steps or units, but may optionally include steps or units not listed, or may optionally include other steps or units inherent to these processes, methods, products, or apparatuses.

[0015] It should be noted that all information (including but not limited to user device information, user personal information, etc.), data (including but not limited to data used for analysis, stored data, displayed data, etc.), and signals involved in this application have been authorized by the user or fully authorized by all parties, and the collection, use, and processing of related data must comply with the relevant laws, regulations, and standards of the relevant countries and regions. For example, the strain data, acceleration data, displacement data, pressure data, and video data involved in this application were all obtained with full authorization.

[0016] Figure 1 This is a flowchart of a method for forming an integral axle housing for an automobile drive axle provided by the present invention.

[0017] Figure 2 This is a flowchart illustrating the specific process of obtaining high-strength steel plates, pre-processing them, and laser cutting them to obtain bridge shell blanks.

[0018] Figure 3 This is a flowchart illustrating the specific steps of setting equipment stamping parameters, lubricating and preheating the die, and placing the bridge housing blank in the die.

[0019] Figure 4 This is a flowchart illustrating the specific process of stamping the bridge housing blank with equipment, holding the pressure, opening the mold to remove the entire bridge housing, and inspecting the entire bridge housing. Detailed Implementation

[0020] The embodiments of the present invention are described in detail below. Examples of the embodiments are shown in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, but should not be construed as limiting the present invention.

[0021] Please see Figures 1 to 4 This invention provides a method for molding an integral axle housing for an automobile drive axle, comprising the following steps: S1 obtains high-strength steel plates, pre-processes them, and laser-cuts them to obtain bridge shell blanks; Specific methods: S11 is used to obtain high-strength steel plates, which are then cleaned and leveled to obtain the steel plate raw material. In this embodiment of the invention, B510L high-strength steel is selected as the raw material for the bridge shell forming. Its excellent cold forming performance can avoid cracking and wrinkling during the stamping process, while its high strength characteristics can meet the load-bearing requirements of the bridge shell.

[0022] Surface cleaning: The steel plate surface is treated with pickling and phosphating processes to remove impurities such as oxide scale and oil stains (pickling temperature 40-50℃, pickling time 15-20 minutes; phosphating temperature 35-45℃, phosphating time 10-15 minutes) to avoid impurities affecting mold life and forming accuracy; Leveling treatment: The steel plate is leveled using a 1200mm wide leveling machine to control the flatness of the steel plate to ≤0.2mm / m, ensuring that the blank is subjected to uniform stress during subsequent blanking and stamping processes.

[0023] S12 uses laser cutting to cut the steel plate raw material based on the billet size.

[0024] In this embodiment of the invention, the steel plate raw material is cut using a fiber laser cutting machine (power 6000W, cutting accuracy ±0.05mm) based on the billet size (dimensions: 1300×116mm) to obtain the bridge shell billet. Nitrogen protection (nitrogen pressure 0.5MPa) is used during the cutting process to prevent oxidation of the cut edges and ensure the quality of the billet edges.

[0025] After cutting, the quality of the blank is checked using the following indicators: Dimensional deviations: length and width deviations ≤ ±0.1mm, thickness deviations ≤ ±0.05mm; Edge quality: The cut is free of burrs and collapse, and the perpendicularity of the edge is ≤0.05mm; Appearance: The surface is free of scratches and oxidation spots, and the flatness is ≤0.1mm.

[0026] S2 sets the equipment stamping parameters, lubricates and preheats the mold, and places the bridge shell blank in the mold; Specific methods: S21 sets the stamping parameters of the equipment, preheats the mold to the preset temperature, and sprays lubricant onto the mold for lubrication; In this embodiment of the invention, the stamping parameters include a main cylinder pressure of 6 MPa, a holding time of 10-12 seconds, an upper limit of the top cylinder of 150 mm, and a preset temperature of 50-60°C. Before stamping, the mold temperature is preheated to 50-60°C using an electric heating device (5 kW) to avoid stress concentration caused by contact between the low-temperature mold and the room-temperature blank; a stamping-specific lubricant (model: KL-800, viscosity 20-30 mm) is uniformly sprayed onto the mold cavity surface. 2 / s), with a spray thickness of 5-8μm, reducing frictional resistance during material forming and improving forming quality.

[0027] S22 Place the bridge shell blank in the mold.

[0028] The S3 equipment stamps the bridge housing blank, holds the pressure, opens the mold to remove the entire bridge housing, and inspects the entire bridge housing.

[0029] Specific methods: The S31 equipment stamps the bridge housing blank, holds the pressure, and then opens the mold to remove the entire bridge housing. In this embodiment of the invention, the equipment stamps the bridge shell blank, and the main cylinder gradually increases the pressure to 6MPa. During this process, the blank gradually forms a flange, cylinder and reinforcing rib structure under the action of the mold cavity (the forming process is monitored in real time by the hydraulic press displacement sensor, and the pressure is automatically adjusted when the displacement deviation exceeds ±0.2mm). After reaching the set pressure, the pressure is maintained for 10-12 seconds. After the pressure is maintained, the main cylinder is depressurized, the upper mold moves slowly upward (speed 50mm / s), and the top cylinder is started to push the ejector rod upward with a pressure of 3MPa, pushing the formed bridge shell out of the lower mold cavity. After the upper mold moves to a safe position (more than 300mm away from the lower mold), a robotic arm with a vacuum suction cup is used to smoothly grab the bridge shell to avoid deformation or scratches caused by manual removal.

[0030] S32 uses compressed air to blow away residual lubricant and metal debris from the surface of the integral bridge housing. In this embodiment of the invention, the integral bridge housing is transferred to the cleaning station, and compressed air (pressure 0.6MPa) is used to blow away the residual lubricant and metal debris on the surface to ensure surface cleanliness (residual impurity particle diameter ≤0.1mm).

[0031] S33 inspects the overall bridge housing quality, removes defective products, and obtains the finished overall bridge housing.

[0032] In this embodiment of the invention, the appearance of the bridge housing is initially inspected. If minor scratches (depth ≤ 0.05 mm) are found, they are manually sanded and repaired using fine sandpaper (800# grit). If there are serious defects such as cracks or wrinkles, they are judged as unqualified products, and the rest are finished bridge housings.

[0033] This invention discloses a method for forming an integral axle housing for an automotive drive axle. By replacing the traditional four or more stamping processes and subsequent auxiliary processes with a single-stage forming process, production time is reduced by 70%, significantly improving production efficiency and meeting the needs of mass production. Furthermore, the one-time stamping process avoids the accumulation of errors from multiple processes, ensuring that key precision indicators such as flange flatness and longitudinal seam straightness meet stringent requirements. The absence of segmented welding structures avoids welding heat deformation and stress concentration, greatly improving welding compatibility and enhancing the overall quality stability of the product. This solves the problems of complex and cumbersome processes and low production efficiency in traditional automotive drive axle housing forming processes.

[0034] To better understand this technical solution, the following embodiments will be used for further explanation: Raw material procurement and inspection: Purchase B510L high-strength steel plates that conform to GB / T3273-2015 standard, and conduct mechanical property tests (tensile test, impact test) and appearance inspection (no scratches or rust on the surface) to ensure that the performance and quality of the steel plates meet the requirements. Laser blanking operation: Based on the cavity dimensions of the bridge housing's first-stage forming mold, the blank's unfolded dimensions are designed to be 1300×116mm. A fiber laser cutting machine (6000W power) is used to cut the blank, with a cutting speed set at 1.5m / min and a cutting accuracy controlled within ±0.1mm. After cutting, the blank edges are deburred (using a grinding wheel, with a grinding width ≤1mm) to prevent scratching the mold or causing product edge cracking during subsequent stamping.

[0035] Before using the mold, check the surface finish of the mold cavity (Ra≤0.8μm, no wear or scratches), apply stamping-specific lubricating oil (model MORESCOHLP-46, coating thickness≤0.1mm) to ensure smooth material flow during stamping; at the same time, check the position deviation of the locating pin (≤0.05mm) to ensure accurate positioning of the blank.

[0036] Equipment debugging and parameter setting: A 1600T four-column hydraulic press (model Y32-1600) was selected as the stamping equipment. During equipment debugging, the smooth operation of the main cylinder and top cylinder was checked (no jamming or abnormal noise), and the pressure sensor (accuracy ±0.05MPa) and displacement sensor (accuracy ±0.01mm) were calibrated. Based on the stamping characteristics of B510L steel, the stamping parameters were set as follows: main cylinder stamping speed 50mm / s (before contact with the blank) and 10mm / s (after contact with the blank), main cylinder pressure 6MPa (verified by trial stamping to prevent product wrinkling), and holding time 11S (to ensure sufficient material shaping and reduce springback).

[0037] Stamping process control: Start the hydraulic press, the upper die descends at a speed of 50mm / s, and when it is 10mm away from the surface of the blank, the speed is reduced to 10mm / s, slowly contacting the blank and starting to apply pressure; when the pressure of the main cylinder reaches 6MPa, maintain the pressure holding state for 11 seconds, during which the temperature of the mold cavity is monitored in real time (detected by an infrared thermometer, the temperature is controlled at 30-40℃ to avoid the lubricating oil from failing due to excessive temperature); after the pressure holding is completed, the upper die rises at a speed of 20mm / s, and at the same time the top cylinder rises at a speed of 10mm / s to lift the formed bridge shell.

[0038] Smooth part removal operation: After the upper mold rises to a safe position (more than 500mm away from the lower mold), close the clamping device and use a special lifting tool (with rubber anti-slip pads to avoid scratching the product surface) to remove the formed bridge shell from the lower mold and place it on a special workstation frame (with a foam cushioning layer on the surface) to prevent the product from deforming due to collision or gravity.

[0039] Preliminary appearance inspection: After taking the part out, visual inspection and touch inspection are used to make a preliminary judgment on the appearance quality of the product: there are no obvious cracks or wrinkles on the surface (focus on checking the transition area between the flange and the cylinder), the reinforcing ribs are fully formed (height deviation ≤ 0.3mm), and there are no dents or bulges; at the same time, check that there are no burrs or flash on the product edges (if they exist, use an angle grinder to trim them, and the edges will be smooth after trimming).

[0040] In accordance with the established product testing standards, the bridge housing produced this time underwent a full range of tests. The testing equipment and methods are as follows: Flange flatness inspection: Using a marble platform (flatness error ≤ 0.01 mm) and a dial indicator (accuracy 0.01 mm), select 8 inspection points evenly on the flange surface, measure the height difference between each point and the marble platform, and calculate the flatness error. Longitudinal joint straightness inspection: A laser length measuring instrument (accuracy ±0.02mm) was used to select 5 test sections along the longitudinal joint direction of the bridge shell, measure the offset of the longitudinal joint at each section, and calculate the straightness error. Dimensional accuracy inspection: Using a coordinate measuring machine (accuracy ±0.03mm), measure key dimensions such as cylinder diameter (select three sections: upper, middle, and lower, and measure four points at each section), cylinder length (distance between the flange end faces at both ends), and flange diameter (outer circle diameter). Compare these dimensions with the dimensions on the design drawings and calculate the dimensional deviations. Mechanical performance sampling inspection: One piece is randomly selected from the products produced this time, and a sample is taken from the bridge housing cylinder part (the sample size conforms to GB / T228.1-2021 standard) to conduct tensile and bending tests, and to test the tensile strength, yield strength and bending angle of the product (≥90° without cracks).

[0041] The above-disclosed method is merely a preferred embodiment of the molding method for an integral axle housing of an automobile drive axle according to this application, and should not be construed as limiting the scope of this application. Those skilled in the art can understand that all or part of the process of implementing the above embodiments and equivalent changes made in accordance with the claims of this application still fall within the scope of this application.

Claims

1. A method for molding an integral axle housing for an automobile drive axle, characterized in that, Includes the following steps: High-strength steel plates are obtained, pretreated, and laser-cut to obtain bridge shell blanks; Set the equipment stamping parameters, lubricate and preheat the mold, and place the bridge shell blank in the mold; The equipment stamps the bridge housing blank, holds the pressure, opens the mold to remove the whole bridge housing, and inspects the whole bridge housing.

2. The method for forming an integral axle housing for an automobile drive axle as described in claim 1, characterized in that, The specific method for obtaining high-strength steel plates, pre-processing them, and laser cutting them to obtain bridge shell blanks is as follows: High-strength steel plates are obtained, their surfaces are cleaned and leveled to obtain raw steel plate material; Based on the billet size, the steel plate raw material is laser-cut to obtain the bridge shell billet.

3. The method for forming an integral axle housing for an automobile drive axle as described in claim 1, characterized in that, The specific method for setting the stamping parameters of the equipment, lubricating and preheating the mold, and placing the bridge shell blank in the mold is as follows: Set the stamping parameters of the equipment, preheat the mold to the preset temperature, and spray lubricant onto the mold for lubrication; The bridge shell blank is placed in a mold.

4. The method for forming an integral axle housing for an automobile drive axle as described in claim 1, characterized in that, The stamping parameters include a main cylinder pressure of 6 MPa, a holding time of 10-12 seconds, a top cylinder upper limit of 150 mm, and a preset temperature of 50-60℃.

5. The method for forming an integral axle housing for an automobile drive axle as described in claim 3, characterized in that, The lubricant is type KL-800, with a viscosity of 20-30 mm. 2 / s, with a coating thickness of 5-8μm.

6. The method for forming an integral axle housing for an automobile drive axle as described in claim 1, characterized in that, The specific method for the equipment to stamp the bridge housing blank, hold pressure, open the mold to remove the integral bridge housing, and inspect the integral bridge housing is as follows: The equipment stamps the bridge housing blank, holds the pressure, and then opens the mold to remove the complete bridge housing. Compressed air is used to blow away residual lubricant and metal debris from the surface of the integral bridge housing. The overall bridge housing quality is inspected, defective products are removed, and the finished overall bridge housing is obtained.

7. The method for forming an integral axle housing for an automobile drive axle as described in claim 1, characterized in that, The flatness of the flange of the integral bridge shell method is ≤0.5mm, and the straightness of the longitudinal joint is ≤1mm.

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