A powertrain assembly line device and method for a four-wheel drive vehicle

Abstract

This invention discloses a powertrain sub-assembly and assembly line device and method for four-wheel drive vehicles, relating to the field of automotive assembly technology. The device includes a support column, a support column holder, a slide mechanism, a sub-assembly platform, and a transfer trolley. The support column is mounted on the platform and slide via the holder, the slide is fixed to the sub-assembly platform, and the platform is supported by the transfer trolley. This invention unifies the sub-assembly support height, angle, and position based on the final assembly posture, ensuring that the powertrain sub-assembly posture matches the final assembly posture. This achieves integrated sub-assembly, transfer, and final assembly line operations, eliminating the need for tooling changes, secondary lifting, and posture adjustments. The slide mechanism enables the combined assembly of the gearbox and engine, and the support column can be quickly switched and replaced, improving versatility. This device features a simple structure, low cost, small footprint, and high flexibility, effectively solving the problems of low efficiency, poor versatility, and posture incompatibility caused by traditional tooling separation. It is suitable for use in the trial production line of four-wheel drive passenger vehicles.

Description

Technical Field

[0001] This invention relates to the field of automotive assembly technology, specifically to a four-wheel drive vehicle powertrain assembly line device and method. Background Technology

[0002] The powertrain sub-assembly and final assembly lines have long used independent workbenches, requiring coordinated operation with multiple equipment such as electric hoists, lifting tools, and forklifts. Existing sub-assembly tooling only meets the assembly operation posture, while final assembly tooling needs to match the vehicle body installation posture. Due to the incompatibility between sub-assembly and final assembly postures, the powertrain must be re-lifted, tooling replaced, and re-aligned after sub-assembly to meet the final assembly alignment requirements. This model suffers from problems such as complex equipment structure, high manufacturing costs, large space occupation, and poor vehicle versatility. The processes are cumbersome, and the risk of accumulated errors is high. It cannot adapt to the flexible production needs of pilot production lines, which require multiple varieties, small batches, and rapid changeovers, becoming a key bottleneck restricting pilot production efficiency and cost control. Summary of the Invention

[0003] Technical problems to be solved The purpose of this invention is to overcome the shortcomings of the prior art and provide a four-wheel drive vehicle powertrain assembly line device and method. Technical solution

[0004] To achieve the above objectives, the present invention provides the following technical solution: a four-wheel drive vehicle powertrain assembly line device, comprising a support column, a support column holder, a slide mechanism, an assembly platform, and a transfer trolley; The support columns are respectively installed on the dispensing platform and the slide mechanism through support column brackets. The slide mechanism is fixed to the dispensing platform, and the entire dispensing platform is supported by the transfer trolley. The device is an integrated tooling for sub-assembly and final assembly. The supporting posture of the powertrain in the sub-assembly state is consistent with the assembly posture in the final assembly state, enabling the entire process of sub-assembly, transfer and final assembly to be completed in the same posture.

[0005] The aforementioned support columns include engine support columns, transmission support columns, and four-wheel drive transfer case support columns. The height, support point, and tilt angle of each support column are uniformly set according to the powertrain assembly posture, so that the powertrain meets the assembly alignment requirements even in the sub-assembly support state.

[0006] As described above, the support column and the support column holder adopt a switchable connection structure. The support column can switch between a vertical support state and a side-lying flat state. The vertical state is used to provide stable support, and the side-lying flat state is used to avoid assembly space.

[0007] As described above, the support column and the support column holder achieve posture switching through the cooperation of the locking pin and the guide groove. After the support column is pulled upward, it can be laid down to the side, and when it is dropped vertically, it can be locked and positioned to maintain a vertical support posture.

[0008] As mentioned above, the upper end of the support column is provided with a positioning structure that matches the powertrain. The positioning structure includes a positioning pin, a positioning surface or an auxiliary support surface. The support column can be quickly replaced to adapt to the support point and posture requirements of different powertrains.

[0009] The aforementioned slide mechanism includes a slide and a linear guide rail. The slide can move in a set direction to achieve the assembly and docking of the gearbox and the engine. The slide is equipped with a locking structure to keep the slide position fixed during the assembly and transfer process, thereby maintaining the stability of the powertrain posture.

[0010] The aforementioned sub-assembly platform is a rigid reference platform. The support column holder and the slide mechanism are positioned and installed on the sub-assembly platform in a preset posture, so that the powertrain maintains a uniform spatial posture during the sub-assembly and final assembly processes.

[0011] As mentioned above, the transfer trolley is equipped with casters and a locking mechanism, which can be positioned and fixed at the sub-assembly station, and can directly transfer the sub-assembly platform carrying the powertrain to the final assembly station in a fixed posture, keeping the powertrain support posture unchanged.

[0012] The aforementioned device can sequentially complete the powertrain sub-assembly, accessory pre-assembly, and final assembly docking with the vehicle body mount on the same tooling, realizing integrated operations of sub-assembly, transfer, and online assembly.

[0013] The above-mentioned feature is that, using the above-mentioned apparatus, the following steps are included: (1) Fix the transfer trolley to the sub-packaging station, adjust the slide mechanism to the assembly preparation position and lock it; (2) The engine, transmission and four-wheel drive transfer case are supported on the corresponding support columns respectively, and the assembly and pre-installation of accessories are completed by the slide mechanism; (3) Keep the powertrain support posture unchanged and push the transfer trolley to the bottom of the vehicle body at the final assembly station; (4) After the powertrain and the vehicle body are aligned and fastened, remove the device to complete the integrated assembly and online process.

[0014] Beneficial effects: Compared with existing technologies, the present four-wheel drive vehicle powertrain assembly line device and method have the following advantages: This invention integrates powertrain sub-assembly and final assembly into a single tooling unit. Using the final assembly posture as a benchmark, it unifies the sub-assembly support structure, ensuring consistency between sub-assembly and final assembly postures. This eliminates the need for secondary hoisting, tooling changes, and posture readjustment, simplifying the assembly process and improving operational efficiency. The device employs a switchable support column and slide table assembly structure, offering strong versatility and adaptability to powertrains from multiple vehicle models. The overall structure is simple, rigid, and reliable, significantly reducing the cost and floor space required for prototyping tooling. It meets the low-cost, high-efficiency, and flexible production requirements of automotive prototyping lines, while simultaneously reducing assembly errors and improving powertrain assembly quality and safety.

[0015] Other advantages, objectives and features of the invention will be set forth in part in the description which follows, and in part will be apparent to those skilled in the art from the following examination or study, or may be learned from the practice of the invention. Attached Figure Description

[0016] Figure 1 This is the overall assembly drawing of the present invention.

[0017] Figure 2 This is a top view of the present invention.

[0018] Figure 3 This is a schematic diagram illustrating the usage state of the present invention.

[0019] Figure 4 This is a flowchart of the assembly method of the present invention. Detailed Implementation

[0020] The present invention will be further described in detail below with reference to the accompanying drawings. This embodiment is only used to explain the present invention and does not constitute a limitation thereof. In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", etc., which indicate the orientation or positional relationship, are based on the orientation or positional relationship shown in the accompanying drawings and are only for the convenience of describing the present invention and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present invention.

[0021] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0022] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0023] This specific embodiment provides a four-wheel drive vehicle powertrain assembly line device, which is suitable for the integrated operation of powertrain assembly, transfer, and assembly line assembly during the trial production stage of four-wheel drive passenger vehicles. It can complete the assembly of the engine, transmission, and four-wheel drive transfer case, the pre-installation of accessories, and the final assembly docking with the vehicle body on the same set of tooling, fundamentally solving the problems of complex processes, high costs, poor versatility, and insufficient flexibility caused by the separation of traditional assembly and final assembly tooling.

[0024] like Figures 1 to 4 As shown, the device as a whole includes a support column 3, a support column holder 4, a sliding table mechanism 5, a sub-assembly platform 6, and a transfer trolley 7. These components are arranged sequentially from bottom to top, forming a stable assembly and transfer system. The transfer trolley 7 serves as a mobile load-bearing base, the sub-assembly platform 6 serves as a rigid installation reference, the sliding table mechanism 5 enables the combined displacement of the gearbox and engine, the support column holder 4 enables rapid positioning and attitude switching of the support column 3, and the support column 3 provides precise support and limitation for the engine, gearbox, and four-wheel drive transfer case. The entire device integrates sub-assembly and final assembly functions, overcoming the long-standing technical bias in this field that sub-assembly and final assembly tooling must be used separately.

[0025] In the existing technology in this field, powertrain assembly and vehicle assembly have long used two completely independent sets of tooling. The core obstacle is not the difference in structural form, but the incompatibility between the assembly posture of the sub-assembly and the final assembly posture. In the sub-assembly stage, the powertrain is required to be placed in a posture that facilitates bolt tightening, accessory installation, and provides sufficient operating space, with support points arranged around the process positioning surfaces of the engine block and transmission housing. In the final assembly stage, the powertrain is required to be presented in a posture that matches the body mounting points, subframe, and chassis system, with support height, tilt angle, front and rear position, and left and right sway all strictly corresponding to the vehicle body installation coordinate system. Since the spatial coordinates, force direction, positioning reference, and support path of the two postures are completely different, traditional sub-assembly tooling cannot maintain the powertrain in the posture required for final assembly after entering the final assembly station. The powertrain must be lifted from the sub-assembly tooling and transferred to a special lifting tool or fixture for final assembly, and then re-limited, aligned, and fixed to meet the vehicle body installation requirements. This process not only increases the risk of hoisting, assembly errors, and labor time, but also requires the configuration of two sets of tooling, resulting in a large footprint, high manufacturing costs, and poor adaptability to vehicle model switching.

[0026] For the automotive prototyping industry, these problems are even more pronounced. During the prototyping phase, there are numerous vehicle models, small batches, and frequent changes in powertrain configurations. Traditional fixed-structure sub-assembly and final assembly tooling cannot quickly adapt to the needs of different vehicle models. Each tooling set can only correspond to a single model, resulting in large tooling inventories, long replacement cycles, and high prototyping costs. Simultaneously, limited space on prototyping production lines means that multiple tooling sets occupying the same space can severely impact workflow and reduce prototyping efficiency. Those skilled in the art have long attempted to solve the integration problem between sub-assembly and final assembly tooling, but have been unable to overcome incompatibility issues, continuing to use a separate sub-assembly and final assembly operation mode. This has become a key technical challenge restricting the flexible and low-cost development of automotive prototyping lines.

[0027] This invention, through structural optimization and unified posture design, enables a single set of tooling to simultaneously meet the requirements of both sub-assembly and final assembly postures. This allows for direct transfer to the final assembly station after sub-assembly for online assembly, without the need to change tooling or readjust the powertrain posture. Its core solution is to use the final assembly posture of the powertrain and vehicle body as the ultimate benchmark, and to reverse-engineer the support positions, positioning methods, height dimensions, and tilt angles during the sub-assembly stage, ensuring consistency between the assembly posture during sub-assembly and the installation posture during final assembly. Simultaneously, through an adjustable, switchable, and foldable support column structure, it accommodates the assembly needs of different engine models and powertrain layouts, ensuring good operational accessibility and assembly accuracy during sub-assembly, and stable support rigidity and alignment accuracy during final assembly, thereby achieving integrated sub-assembly and final assembly operations.

[0028] The statement that the powertrain's component assembly posture is consistent with its final assembly posture in this invention means that after the powertrain completes the assembly of the engine, transmission, four-wheel drive transfer case and the separate assembly of accessories, its spatial height, pitch angle, left and right tilt angle and horizontal installation position are exactly the same as the final assembly posture required when the powertrain is suspended and docked with the vehicle body during the final assembly stage. Specifically, uniformity is achieved through the following dimensions: First, uniform support height: the support height of each support column is set according to the center of gravity height and mounting height of the powertrain in the final assembly posture, ensuring that the mounting height of the powertrain after sub-assembly matches the alignment height of the final assembly; Second, uniform pitch angle: the overall support plane formed by the support column layout is consistent with the front and rear pitch angles of the powertrain in the final assembly state, without any additional forward or backward tilt; Third, uniform left and right tilt angle: the height difference between the left and right support columns matches the left and right horizontality required by the final assembly, ensuring that the powertrain maintains a horizontally consistent posture with the vehicle body installation; Fourth, uniform support point location: the support points avoid interference areas during final assembly, are compatible with the force path during final assembly, and do not affect the docking and assembly of the powertrain and the vehicle body; Fifth, uniform coordinate reference: the same spatial coordinate system is used for sub-assembly and final assembly, and tooling is designed in reverse with the vehicle body mounting point as the reference, ensuring that there is no deviation between the sub-assembly positioning and the final assembly positioning. With the above-mentioned unified posture design, the powertrain can be directly put into the final assembly station after the sub-assembly is completed to complete the docking and assembly with the body, without the need for posture adjustment, support replacement or secondary hoisting.

[0029] The support column 3 is the core component of this device that directly contacts the powertrain, and is used to support, position, and limit the engine assembly, transmission assembly, and four-wheel drive transfer case. In this embodiment, multiple support columns 3 are provided, collectively divided into engine support columns, transmission support columns, and four-wheel drive transfer case support columns. The engine and four-wheel drive transfer case can share some support columns, reducing the number of components while optimizing the spatial layout and avoiding support interference. Each support column 3 is connected to the support column holder 4 by a snap-fit ​​pin. A guide groove is provided on the support column 3; pulling it upwards along the snap-fit ​​pin allows it to be laid flat laterally, facilitating the avoidance of accessory installation space; pulling it upwards to its limit position and then placing it vertically downwards allows it to snap into the support column holder 4, ensuring the support column 3 maintains a stable, vertically upward support state, meeting the force requirements during sub-assembly and final assembly. By pulling out the locking pin, support columns 3 of different specifications can be quickly disassembled and replaced. The upper structure of support column 3 is matched and processed according to the support interface of engine, transmission and transfer case. It can adopt the form of positioning pin, positioning surface, auxiliary support surface, etc., which can adapt to the support positioning requirements of different models of engine, transmission and transfer case, and improve the versatility of the device.

[0030] Reference Figure 1 and Figure 2As shown, the entire assembly platform is divided into three areas: the area where the slide is located, and the engine support area 01 and transfer case support area 02, as indicated in the figure. One support column 021 has at least two positioning blocks on its end face, corresponding to one support point for the engine and one for the transfer case, respectively. Furthermore, this support column 021 is located near the sliding limit position of the slide, at the junction of the three assembly modules. The advantage of this design is that, under the premise of matching the assembly posture, the position of the support column is rationally set, improving the installation support effect of the assembly process.

[0031] The switchable posture design of the support columns is one of the key structural features for achieving compatibility between sub-assembly and final assembly postures. During sub-assembly, for areas requiring clearance from pipes and wiring harnesses, the corresponding support columns can be laid flat to the side, expanding the operating space. During final assembly, all support columns are reset to a vertical position, forming a stable support frame to ensure the powertrain does not tilt or shift when docked with the vehicle body. This design allows for rapid posture switching without the need for additional tools, simplifying operation and adapting to the rapid operation requirements of prototyping lines. The height, layout, and top support surface of the support columns are uniformly set according to the final assembly posture, ensuring the powertrain naturally assumes the required posture after being supported, eliminating the need for subsequent adjustments.

[0032] The support column holder 4 adopts a stepped hole structure design to form a stable locking fit with the support column 3, while also providing guidance and limiting for the posture switching of the support column 3. The number of support column holders 4 is the same as the number of support columns 3, and they are respectively installed on the sub-assembly platform 6 and the sliding mechanism 5. The support column holder 4 is securely connected to the sub-assembly platform 6 and the sliding mechanism 5 using locating pins and fasteners. The locating pins ensure installation position accuracy, and the fasteners provide sufficient connection rigidity to prevent loosening, displacement, or deformation during sub-assembly, transfer, and final assembly, ensuring that the powertrain support position remains accurate at all times. The stepped hole structure can form a wrap-around limiting effect on the bottom of the support column 3, improving support stability and preventing tilting or shaking under force, ensuring sub-assembly accuracy and final assembly alignment accuracy. The installation position of the support column holder is precisely positioned based on the final assembly posture, ensuring that the support point, height, and angle of each support column match the preset assembly posture. Structurally, this eliminates powertrain posture deviation caused by support position deviation, eliminating the need to readjust the limiting position during the final assembly stage.

[0033] The sub-assembly platform 6, serving as the installation reference platform for the entire device, is machined from sheet metal, possessing high structural rigidity and flatness. This ensures the installation accuracy of the support column holder 4 and the sliding table mechanism 5, thereby guaranteeing the assembly accuracy of all powertrain components. The sub-assembly platform 6 can be directly and stably placed on the transfer trolley 7, enabling rapid placement and removal without additional positioning structures, simplifying the operation process. The sub-assembly platform 6 has sufficient structural rigidity to prevent significant deformation when supporting the powertrain, ensuring consistency between the sub-assembly and final assembly postures and preventing powertrain posture deviation due to platform deformation, which could affect final assembly docking. As a shared reference platform for both sub-assembly and final assembly, the installation reference surface of the sub-assembly platform coincides with the alignment reference surface of the final assembly, ensuring that the powertrain remains under a unified spatial reference throughout the sub-assembly and final assembly processes, maintaining a stable posture.

[0034] The slide mechanism 5 is used to assemble and connect the gearbox assembly and the engine assembly. It consists of a slide and linear guide rails. The slide can move linearly in a set direction to meet the displacement requirements for connecting the gearbox and engine. Safety limit blocks are set at the extreme positions of the slide to prevent derailment or collision due to overtravel, thus improving safety. A locking structure is installed on the slide to lock it after the gearbox assembly is hoisted, preventing accidental sliding during assembly and ensuring assembly safety and accuracy. All exposed protruding parts of the slide are rounded to eliminate sharp edges and prevent operators from being injured during assembly and transportation, meeting ergonomic design requirements. The slide mechanism 5 is integrated into the sub-assembly platform 6, allowing assembly operations to be completed on the same tooling without the need for an additional assembly stand, further simplifying the device structure. In the locked state, the slide maintains the relative positions of the gearbox and engine, ensuring that the posture of the powertrain does not change after assembly, providing a stable foundation for subsequent transportation and final assembly.

[0035] The transfer trolley 7 consists of a frame structure and casters. The frame structure is welded from profiles, resulting in a robust structure with moderate weight and sufficient load-bearing capacity. A reinforcement structure is installed on the underside of the frame to secure the caster mounting positions, preventing weld cracking and panel deformation over long-term use. The casters are a combination of swivel casters and directional casters with locking mechanisms. The swivel casters facilitate flexible steering and movement, while the directional casters ensure straight-line stability. The locking mechanism can secure the trolley at sub-assembly and final assembly stations, preventing accidental slippage. A push handle is provided on the side of the trolley for easy pushing by operators, meeting the strength requirements for manual operation. The transfer trolley 7 not only transports the sub-assembly platform 6 and the powertrain but also serves as a support carrier during the final assembly stage, maintaining the powertrain in a preset posture for docking with the vehicle body. This allows sub-assembly tooling to be directly used in final assembly without the need for tooling changes. During transport, the transfer trolley maintains the sub-assembly platform's horizontal stability, preventing changes in the powertrain's posture due to shaking or tilting, ensuring the powertrain maintains a consistent assembly posture throughout the entire process from the sub-assembly station to the final assembly station.

[0036] The operation process of this device is divided into two stages: powertrain sub-assembly and powertrain online assembly. The two stages are completed continuously without tooling replacement, secondary hoisting, or attitude adjustment in between.

[0037] In the powertrain sub-assembly stage, the transfer trolley 7 is first pushed to the sub-assembly station, and the locking casters keep the trolley fixed, providing a stable foundation for the sub-assembly operation. The slide mechanism 5 is slid along the linear guide rail to the assembly preparation position, and the slide is locked by the locking structure to prevent the slide from moving when the gearbox is hoisted. The engine assembly is smoothly hoisted onto the engine support column using hoisting equipment. The upper end of the support column precisely matches the engine process interface to achieve positioning and support. The gearbox assembly is hoisted onto the gearbox support column on the slide mechanism 5, and the gearbox support column provides stable support for the gearbox housing. The slide locking structure is released, and a sealing gasket is installed on the engine and gearbox mating surface. The slide is then pushed to move the gearbox assembly in the set direction until the gearbox and engine mating surfaces are completely fitted. Bolts are used to fasten the gearbox and engine together. The four-wheel drive transfer case is hoisted onto the transfer case support column, and the transfer case support column matches the transfer case housing interface. Bolts are used to connect and fix the four-wheel drive transfer case to the gearbox. The engine wiring harness, pre-catalytic converter, electric water pump, coolant hoses, fuel hoses, and other accessories are sequentially installed onto the powertrain, completing the powertrain sub-assembly. Throughout the sub-assembly process, the powertrain maintains the same posture as the final assembly, and the support position, height, and angle do not require adjustment.

[0038] During the sub-assembly process, the switchable posture of the support column can be flexibly adjusted according to the accessory installation requirements without moving the powertrain, thus avoiding precision loss caused by assembly displacement. The precise movement of the slide mechanism ensures uniform gap between the engine and transmission and tight contact between the mating surfaces, improving the sub-assembly quality of the powertrain. After sub-assembly, the powertrain's spatial height, pitch angle, lateral tilt angle, and horizontal position are completely consistent with the final assembly posture, making it ready for direct assembly on the production line.

[0039] During the powertrain assembly phase, the locking mechanism of the seven casters on the transfer trolley is released. Operators push the trolley to transfer the pre-assembled powertrain to the final assembly station, placing it on the lift under the vehicle body to be assembled. The trolley's position is adjusted to precisely align the powertrain mount points with the vehicle body mount points. The lift is then lowered to ensure the vehicle body mount positioning holes align with the powertrain mount positioning pins. Bolts are then used to secure the powertrain mounts to the vehicle body. After connection, the lift is raised to separate the vehicle body from the assembly, pushing the assembly out from under the vehicle body to the designated area, allowing the cycle to begin with the next vehicle's powertrain sub-assembly and assembly. In the final assembly phase, the sub-assembly fixtures are used directly as supports and alignment carriers. The powertrain's posture is completely consistent with the sub-assembly phase, eliminating the need for re-positioning, alignment, and adjustments, significantly improving assembly efficiency and precision.

[0040] The core advantage of this device compared to existing technologies is that no attitude adjustment of the powertrain is required during the final assembly stage. In traditional processes, transferring the powertrain from the sub-assembly fixtures to the final assembly fixtures requires multiple people to lift it, which is time-consuming and prone to problems such as bumps and positioning deviations. With this device, a single person can complete the transfer and alignment work, significantly reducing the time required, greatly improving assembly efficiency, and eliminating the quality risks associated with secondary lifting.

[0041] As is known to those skilled in the art, traditional sub-assembly fixtures are only suitable for bench assembly. Their structural design does not consider the space of the final assembly line, the lift travel, and the installation environment under the vehicle body. The support height, support angle, and support rigidity cannot meet the requirements of final assembly. Furthermore, the posture of the powertrain on the sub-assembly fixture does not match the vehicle body installation posture. Therefore, the powertrain must be transferred to the final assembly fixture. This invention, through an integrated structural design, enables the sub-assembly fixture to simultaneously possess the functions of a final assembly fixture. The sub-assembly structure is designed based on the final assembly posture. Through structures such as switchable support columns, slide table fine-tuning, rigid platforms, and stable transfer trolleys, it ensures that the powertrain maintains a consistent posture, stable support, and precise positioning during both sub-assembly and final assembly processes, eliminating the need for fixture switching due to posture differences.

[0042] From a technical principle perspective, this device solves the core problem of incompatible orientations by establishing a unified assembly coordinate system, integrating sub-assembly and final assembly processes into the same datum system. Traditional sub-assembly tooling uses ease of sub-assembly operation as the sole datum, while final assembly tooling uses vehicle body installation as the sole datum; these two datums are independent of each other. This device uses the vehicle body installation datum as the overall datum, with the sub-assembly datum coinciding with the overall datum, thus enabling two sets of processes to share a single tooling. This design concept overturns the traditional tooling design logic in this field, providing a completely new technical path for the integration of powertrain assembly tooling.

[0043] Compared with existing technologies, this device integrates sub-assembly and final assembly in its structure, reducing the number of tooling, lowering manufacturing costs, and saving production space. In terms of process, it allows for direct assembly and production line deployment after sub-assembly, eliminating secondary hoisting, tooling replacement, and posture adjustment procedures, thus improving assembly efficiency. Regarding adaptability, replaceable support columns meet the needs of multiple vehicle models and powertrains, enhancing flexibility. In terms of precision, it avoids error accumulation caused by posture switching, improving assembly quality. This device is particularly suitable for the multi-variety, small-batch, and rapid changeover production needs of automotive prototyping lines, effectively reducing prototyping costs and shortening the prototyping cycle.

[0044] In actual trial production applications, this device is adaptable to various four-wheel drive powertrain configurations. Vehicle model switching can be completed simply by changing the support column, resulting in short switching time and strong adaptability. The device has a small overall footprint, which can significantly save space in the trial production line. At the same time, the device has a simple structure, low processing difficulty, low manufacturing cost, and significant economic benefits.

[0045] The successful application of this device proves the feasibility of integrating powertrain sub-assembly and final assembly tooling, breaks through long-standing technical biases in the field, and provides a new direction for the development of automotive assembly tooling technology. Those skilled in the art can make structural adjustments based on the core concept of this invention, according to different vehicle models and powertrain configurations, all of which fall within the scope of protection of this invention.

[0046] In another preferred embodiment of this application, a design method for a tooling device is also disclosed. The core of this method lies in reverse engineering based on the final assembly posture, ensuring the consistency of posture throughout the entire process of sub-assembly, transfer, and final assembly. The specific steps are as follows: Determine the target attitude for final assembly: First, by consulting the vehicle CAD model, final assembly process documents, or actual measurements, accurately obtain the spatial attitude of the four-wheel drive powertrain during final assembly with the body. This includes the three-dimensional position of the powertrain, pitch angle, roll angle (left and right tilt angle), and its relative positional relationship with the body mounting points. Define this attitude as the target attitude for the design.

[0047] Taking the Chery T1P four-wheel drive vehicle as an example, the tooling support surface in the engine area forms a 6.3-degree angle with the tooling workbench. Other support surfaces are designed with reference to the engine area support surface and are adapted to the parts assembly method, ensuring that this tooling can be used for both sub-assembly and assembly line installation. Reverse engineering is performed to design the geometric parameters of the support columns based on the determined target assembly orientation. Using 3D modeling software (such as CATIA, SolidWorks) or finite element analysis (FEA) tools, the stress distribution and support requirements of the powertrain under the target orientation are simulated. Based on these analysis results, the geometric parameters of multiple support columns in the tooling are precisely determined, including: Support height: Designed based on the vertical height of each support point of the powertrain in the target posture.

[0048] Support points: Select power system main structure that avoids the interference area of ​​the final assembly and can provide stable support as support points, and ensure that these points are compatible with the force path during final assembly.

[0049] Tilt angle: Based on the pitch and roll angles of the powertrain in the target attitude, the tilt angle of the support column is designed to ensure that the powertrain naturally presents the target attitude after being supported.

[0050] Meanwhile, considering the switchable posture function of the support column, a matching structure of the locking pin and guide groove is designed to reliably switch between vertical support and lateral flattening states, and to ensure the positioning accuracy after switching.

[0051] Design the slide mechanism: Design a slide mechanism that enables precise assembly and docking of powertrain components (such as the engine and transmission). The slide should have the ability to move smoothly along a predetermined direction (usually the powertrain assembly axis) and be equipped with a reliable locking structure to fix the slide after assembly, ensuring that the powertrain as a whole maintains the target posture after assembly.

[0052] Design a transfer trolley: Design a transfer trolley with sufficient load-bearing capacity and stability to carry the sub-assembly platform and the assembled powertrain. The transfer trolley should be equipped with casters (a combination of swivel casters and fixed casters) with locking mechanisms to ensure fixed positioning at the sub-assembly and final assembly stations, and to maintain the horizontal stability of the sub-assembly platform during transfer, preventing changes in the powertrain's posture due to shaking or tilting. This achieves integrated, posture-consistent transfer from the sub-assembly station to the final assembly station.

[0053] The above design method ensures that the tooling device can maintain the same posture as the final assembly throughout the entire process of sub-assembly, transportation and final assembly of the powertrain, thus completely solving the problems caused by the separation of traditional tooling.

[0054] The structural forms, connection methods, and operation processes described in this specific embodiment are only preferred embodiments. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this invention should be included within the protection scope of this invention.

Claims

1. An apparatus for assembling a powertrain of a four-wheel drive vehicle, comprising: Includes support columns, support column holders, sliding table mechanisms, dispensing platforms, and transfer trolleys; The support columns are respectively installed on the dispensing platform and the slide mechanism through support column brackets. The slide mechanism is fixed to the dispensing platform, and the entire dispensing platform is supported by the transfer trolley. The device is an integrated tooling for sub-assembly and final assembly. The supporting posture of the powertrain in the sub-assembly state is consistent with the assembly posture in the final assembly state, and the entire process of sub-assembly, transfer and final assembly can be completed in the same posture.

2. The apparatus of claim 1, wherein, The support columns include engine support columns, transmission support columns, and four-wheel drive transfer case support columns. The height, support point, and tilt angle of each support column are uniformly set according to the powertrain assembly posture, so that the powertrain meets the assembly alignment requirements even in the sub-assembly support state.

3. The apparatus of claim 1, wherein, The support column and the support column holder adopt a switchable connection structure. The support column can switch between a vertical support state and a side-lying flat state. The vertical state is used to provide stable support, and the side-lying flat state is used to avoid assembly space.

4. The apparatus of claim 3, wherein, The support column and the support column holder are switched in posture by means of a locking pin and a guide groove. When the support column is pulled up, it can be laid down to the side. When it is dropped vertically, it can be locked in place and maintain a vertical support posture.

5. The apparatus of claim 1, wherein, The upper end of the support column is provided with a positioning structure that matches the powertrain. The positioning structure includes a positioning pin, a positioning surface or an auxiliary support surface. The support column can be quickly replaced to adapt to the support point and posture requirements of different powertrains.

6. The apparatus of claim 1, wherein, The slide mechanism includes a slide and a linear guide rail. The slide can move in a set direction to achieve the assembly and docking of the gearbox and the engine. The slide is equipped with a locking structure to keep the slide position fixed during the assembly and transfer process, thereby maintaining the stability of the powertrain posture.

7. The apparatus of claim 1, wherein, The sub-assembly platform is a rigid reference platform. The support column holder and the slide mechanism are positioned and installed on the sub-assembly platform in a preset posture, so that the powertrain maintains a uniform spatial posture during the sub-assembly and final assembly processes.

8. The apparatus of claim 1, wherein, The transfer trolley is equipped with casters and a locking mechanism, which can be positioned and fixed at the sub-assembly station, and can directly transfer the sub-assembly platform carrying the powertrain to the final assembly station in a fixed posture, keeping the powertrain support posture unchanged.

9. The device of any one of claims 1-8, wherein, The device can sequentially complete the powertrain sub-assembly, accessory pre-assembly, and final assembly docking with the vehicle body on the same tooling, realizing integrated operation of sub-assembly, transfer, and online assembly.

10. A method for assembling and installing a powertrain for a four-wheel drive vehicle, characterized in that, Using the apparatus according to any one of claims 1-9, the steps include: (1) Fix the transfer trolley to the sub-packaging station, adjust the slide mechanism to the assembly preparation position and lock it; (2) The engine, transmission and four-wheel drive transfer case are supported on the corresponding support columns respectively, and the assembly and pre-installation of accessories are completed by the slide mechanism; (3) Keep the powertrain support posture unchanged and push the transfer trolley to the bottom of the vehicle body at the final assembly station; (4) After the powertrain and the vehicle body are aligned and fastened, remove the device to complete the integrated assembly and online process.

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