Commercial vehicle power assembly motion limiting design method

Abstract

The invention provides a commercial vehicle power assembly motion limiting design method. The method specifically comprises the steps that the static boundary of a power assembly is input; determining the arrangement position of a suspension anti-vibration pad of the power assembly; designing the size of an anti-vibration pad limiting structure; deducing the motion boundary of the power assembly according to the static boundary of the power assembly, the arrangement position of the anti-vibration pad and the limiting size of the anti-vibration pad; checking whether the motion boundary of the power assembly meets the design boundary requirement of the whole vehicle or not; if not, the arrangement position and the limiting size of the anti-vibration pad are adjusted, the checking step is repeated, and if yes, a design scheme is output. The main purpose is to provide normative and feasible power assembly dynamic boundary checking and the arrangement position and limiting size design basis of an anti-vibration pad in the whole vehicle design stage. By applying the design method, the design quality of the power assembly peripheral parts can be improved in the whole vehicle design stage, the development period is shortened, the development cost is saved, meanwhile, market problems are effectively reduced, the customer transportation efficiency is guaranteed, and the product market public praise is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of design and development of power assemblies and accessories thereof, and in particular to a motion limiting design method for a commercial vehicle power assembly. Background Art

[0002] During the automobile development process, the layout of the engine compartment is an important part of the vehicle development process. The selection of the powertrain (including the combination of the engine, gearbox, and motor), installation feasibility analysis, adaptation to the requirements of the surrounding environment parts of the new powertrain, and verification of the development plan of the new powertrain involve a wide range of aspects and require high professional quality of developers. The existing technical solutions mainly rely on the experience of developers to seek a reasonable position for the powertrain layout, verify the requirements of the powertrain and the surrounding environment parts, repeatedly adjust the powertrain position and plan, measure and verify the relevant gap values ​​between the powertrain layout and the relevant boundaries to identify gap risk items and the need to change related components, and then through repeated adjustments and verification processes of the plan, finally determine the powertrain layout position and installation plan to complete the final installation work, resulting in a long engine compartment layout verification cycle and high development and debugging costs.

[0003] Traditional methods for measuring powertrain displacement typically involve selecting a test vehicle model, placing displacement sensors at relevant locations on the powertrain, and then measuring the displacement of various points on the engine and transmission while the vehicle is unloaded and fully loaded on flat, twisting, and Belgian roads. However, this test method requires a prototype vehicle, which can have component assembly and performance issues. This incurs trial production costs, testing cycles, and testing fees. If component modifications are required after testing, some mold components must be redesigned, resulting in high costs and a long lead time. This can delay the launch of new products and impact brand competitiveness.

[0004] Alternatively, they can compile data based on aftermarket feedback from existing models and accumulate information about powertrain component interference. However, this data, recorded through aftermarket feedback, indicates that a fault has occurred, which can lead to component damage at the very least, or even complete vehicle inoperability, casualties, or cargo loss, seriously impacting product reputation. Summary of the Invention

[0005] To reduce vehicle development costs, shorten development cycles, lower the failure rate of powertrains and their peripheral components in the aftermarket, ensure customer operational efficiency, and improve product reputation, this paper proposes a design method for commercial vehicle powertrain motion limits, which can effectively provide design boundaries, standardize design methods, and improve the quality of design solutions.

[0006] The present invention is achieved by adopting the following technical solutions:

[0007] A method for designing a motion limiter for a commercial vehicle powertrain comprises the following steps:

[0008] 1) Input the static boundaries of the powertrain and surrounding accessories;

[0009] 2) Determine the layout location of the powertrain suspension vibration damping pad;

[0010] 3) Design the size of the vibration damping pad limit structure, requiring limit structures in the x, y, and z directions. Adjust the position of the vibration damping pad and the gap between the inner and outer frames to control the motion boundary size of the powertrain.

[0011] 4) Perform motion analysis on the static boundaries of the powertrain and surrounding accessories, including translation in the x, y, and z directions, rotation in the Rx, Ry, and Rz directions, and various combinations of x, y, and z translations and Rx, Ry, and Rz rotations;

[0012] 5) Check the clearance between the boundary of the powertrain movement and the surrounding parts of the vehicle. If it does not meet the vehicle layout requirements, modify the vibration damping pad layout position or limit size, and re-perform the powertrain movement analysis and check the surrounding parts of the vehicle;

[0013] 6) Output the dynamic motion boundary size of the powertrain to provide a boundary for the design of peripheral parts of the vehicle, and at the same time output the design plan of the vibration damping pad layout position and limit size.

[0014] According to further description of the present application, in step 1), the powertrain and surrounding accessories include an engine, a gearbox, and a motor.

[0015] According to the further description of the present application, in step 2), four vibration damping pads are provided, and the arrangement schemes of the vibration damping pads include three methods: "both sides of the front end of the engine cylinder block + both sides of the engine flywheel housing", "both sides of the front end of the engine cylinder block + both sides of the gearbox clutch housing", and "both sides of the front end of the engine cylinder block + both sides of the rear end of the gearbox".

[0016] According to further description of the present application, in step 3), the vibration damping pad is a vibration damping pad with a wedge-shaped composite structure, which is the structure of patent CN2214164720U.

[0017] In step 3), the adjustment of the vibration damping pad arrangement position is to adjust three different arrangement schemes to control the powertrain motion boundary size; among them, the "two sides of the front end of the engine cylinder block + two sides of the engine flywheel housing" arrangement scheme has the largest powertrain motion boundary size, the "two sides of the front end of the engine cylinder block + two sides of the transmission clutch housing" arrangement scheme has a moderate powertrain motion boundary size, and the "two sides of the front end of the engine cylinder block + two sides of the rear end of the transmission" arrangement scheme has the smallest powertrain motion boundary size.

[0018] According to further description of the present application, in step 4), the motion analysis also includes forward / reverse x, y, z translation or Rx, Ry, Rz rotation, as well as various combinations of forward / reverse x, y, z translation and forward / reverse Rx, Ry, Rz rotation.

[0019] Furthermore, in step 4), the motion analysis includes the following situations:

[0020] S1) positive x-, y-, and z-translations;

[0021] S2) positive Rx rotation, Ry rotation, Rz rotation;

[0022] S3) positive x-translation + positive Rx / Ry / Rz rotation;

[0023] S4) positive y translation + positive Rx / Ry / Rz rotation;

[0024] S5) Positive z translation + positive Rx / Ry / Rz rotation.

[0025] S6) reverse x-, y-, and z-direction translation;

[0026] S7) reverse Rx rotation, Ry rotation, and Rz rotation;

[0027] S8) negative x-translation + positive Rx / Ry / Rz rotation;

[0028] S9) negative y translation + positive Rx / Ry / Rz rotation;

[0029] S10) Reverse z-translation + forward Rx / Ry / Rz rotation;

[0030] S11) positive x-translation + negative Rx / Ry / Rz rotation;

[0031] S12) positive y translation + negative Rx / Ry / Rz rotation;

[0032] S13) Forward z translation + reverse Rx / Ry / Rz rotation.

[0033] According to the further description of the present application, in step 5), the peripheral parts of the whole vehicle include the cab floor, sound insulation board, front and rear suspension of the cab, cab flip mechanism, frame and its tube beam, cross beam and basin beam, front axle I-beam, front suspension, anti-roll bar, cooling module and its air pipeline, steering cylinder and its pipeline, exhaust butterfly valve and after-treatment air pipeline, intake pipeline and air filter, transmission operating mechanism, air compressor air pipeline, fuel or gas pipeline, and peripheral electrical wiring harness pipeline.

[0034] Compared with the prior art, the present invention has the following beneficial effects:

[0035] This patent is applied to the development and design of heavy-duty commercial vehicle powertrains and their accessories. It can be used for dynamic interference verification of powertrains and their accessories during the design and development phase of the entire vehicle, provide design verification boundaries for peripheral parts, and adjust and optimize design solutions. Applying the design method of the present invention during the design phase can significantly improve the design quality of the entire vehicle, on the one hand reducing trial production costs, test cycles, and test costs, and on the other hand reducing the failure rate of market models, effectively enhancing brand competitiveness. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Attachment Figure 1 Schematic diagram of the main movement modes of the commercial vehicle powertrain of the present invention.

[0037] Attachment Figure 2 Flowchart of the design method of the present invention.

[0038] Attachment Figure 3 Schematic diagram of the wedge-shaped vibration damping pad structure;

[0039] Reference numerals: 1 is a vibration damping pad; 2 is a gearbox; 3 is an engine; 11 is an external skeleton; 12 is an internal skeleton; 13 is rubber. DETAILED DESCRIPTION

[0040] In order to enable those skilled in the art to better understand the technical solutions of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings of 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. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts should fall within the scope of protection of the present invention.

[0041] The design of the powertrain layout is an important part of the vehicle development process. The design of the powertrain layout is generally based on the existing vehicle layout plan. The design concept of the existing technology is: based on the existing vehicle layout plan, the powertrain design boundary (powertrain peripheral parts: cab floor, frame, front axle and other components) and its motion envelope are extracted to generate a closed powertrain design boundary. To match this boundary, the powertrain body is required to undergo partial design changes. For example, the engine body is required to change the shape of the oil pan to avoid the I-beam of the front axle of the vehicle.

[0042] This application uses innovative reverse development for design, directly matching finished powertrains on the market, extracting the powertrain's overall design boundaries, including static boundaries and its motion envelope. To match this boundary, the entire vehicle and powertrain peripheral parts are adaptively designed and changed and developed, mainly by changing the layout position of the powertrain on the vehicle, limiting the size of the powertrain's motion envelope boundary, and changing the structural dimensions of the powertrain's peripheral parts. For example, the engine oil pan is close to the front axle I-beam, and the vehicle matching development can be completed by raising the engine.

[0043] This application provides design boundaries for other parts of the vehicle based on the powertrain's motion boundaries, and can adjust the engine's motion boundaries based on the vehicle's needs. That is, without considering the engine compartment and surrounding parts, the powertrain's motion range boundaries are first calculated based on the engine and gearbox's own boundaries, combined with the vibration damping pad layout and limit structure, to constrain the design boundaries of other parts in the engine compartment. At the same time, if the motion range exceeds the design requirements, the powertrain's motion range boundaries are narrowed by adjusting the vibration damping pad layout and limit dimensions. Because the design idea is to match the finished powertrain, the powertrain matching solution can be customized according to market demand or customer preferences. The vehicle cannot require every engine and gearbox manufacturer on the market to modify the engine and gearbox size according to the vehicle's boundaries. Therefore, by extracting boundaries through this method, one or several vehicle layout solutions can be completed, which are compatible with all powertrain layout requirements on the market.

[0044] This application provides a method for designing motion limiters for a commercial vehicle powertrain, which specifically includes the following steps:

[0045] 1) The static boundaries of the input powertrain and surrounding accessories; the powertrain and surrounding accessories include the engine, gearbox, and motor.

[0046] 2) Determine the placement of the powertrain suspension vibration damping pads; the placement of the vibration damping pads is at the front end of the engine cylinder block and on both sides of the gearbox.

[0047] 3) Design the size of the vibration damping pad limit structure, requiring the limit structure to be provided in the x, y, and z directions, and adjust the layout of the vibration damping pad and the gap size between the inner and outer frames to control the motion boundary size of the powertrain; the vibration damping pad adopts a wedge-shaped composite structure, which is the structure of patent CN2214164720U, such as Figure 3 shown.

[0048] 4) Perform motion analysis on the static boundaries of the powertrain and surrounding accessories, primarily including translations in the x, y, and z directions; rotations in the Rx, Ry, and Rz directions; and various combinations of x, y, and z translations and Rx, Ry, and Rz rotations. This motion analysis also includes forward / reverse x, y, and z translations or Rx, Ry, and Rz rotations, as well as various reverse / forward combinations of forward / reverse x, y, and z translations and Rx, Ry, and Rz rotations.

[0049] 5) Verify the clearance between the rear boundary of the powertrain movement and the surrounding parts of the vehicle. If it does not meet the vehicle layout requirements, modify the vibration damping pad layout position or limit size, re-perform the powertrain movement analysis and verify the surrounding parts of the vehicle; the surrounding parts of the vehicle include the cab floor, frame, front axle I-beam, and cooling module.

[0050] 6) Output the dynamic motion boundary size of the powertrain to provide a boundary for the design of peripheral parts of the vehicle, and at the same time output the design plan of the vibration damping pad layout position and limit size.

[0051] The present application adopts a vibration damping pad with a wedge-shaped composite structure. The structure is detailed in patent CN2214164720U, entitled "A Heavy-Duty Commercial Vehicle Powertrain Suspension System Vibration Damping Pad": By improving the traditional vertical compression type vibration damping pad into a wedge-shaped composite compression type vibration damping pad, multi-dimensional compression of the vibration damping pad in the vertical and horizontal directions is achieved, adapting to the full range of vibration of the engine, thereby making the relevant system more stable; by setting the limiting boss and the inlaid cavity wall, the displacement of the inner skeleton can be limited when it is compressed again; by setting the elastic material between the inner skeleton and the outer skeleton, the maximum displacement of the inner skeleton under force can be kept constant, because the elastic modulus of the same elastic material is the same, its ability to resist elastic deformation is the same, thereby improving the accuracy of the vibration damping pad system; further, it can greatly improve the reliability and NVH (noise, vibration and harshness) performance of the powertrain accessory system; if different maximum displacements are required, the rubber material formula can be adjusted to further adapt to the system requirements.

[0052] The mainstream setting of the vibration damping pads is 4, and the arrangement schemes of the vibration damping pads include three types: "both sides of the front end of the engine cylinder block + both sides of the engine flywheel housing", "both sides of the front end of the engine cylinder block + both sides of the gearbox clutch housing", and "both sides of the front end of the engine cylinder block + both sides of the rear end of the gearbox".

[0053] In step 3), adjusting the arrangement position of the vibration damping pad is adjusting three different arrangement schemes to control the motion boundary size of the powertrain;

[0054] Among them, the powertrain motion boundary size of the "both sides of the front end of the engine cylinder block + both sides of the engine flywheel housing" layout scheme is the largest, the powertrain motion boundary size of the "both sides of the front end of the engine cylinder block + both sides of the transmission clutch housing" layout scheme is moderate, and the powertrain motion boundary size of the "both sides of the front end of the engine cylinder block + both sides of the rear end of the transmission" layout scheme is the smallest.

[0055] Translation in the x, y, and z directions: For example, when the vehicle suddenly accelerates, the powertrain will move backward relatively due to inertia, that is, translation in the x direction, and similarly in other directions.

[0056] Rotation in three directions: Rx, Ry, and Rz: For example, when the vehicle is driving normally, there is a pothole on the ground, and the front wheel of the vehicle suddenly falls into the pothole. The height of the front wheel decreases, but the height of the rear wheel does not change. The whole vehicle produces a downward movement. At this time, due to inertia, the powertrain produces a rotation relative to the whole vehicle, that is, a rotation in the Ry direction, and so on in other directions. This most commonly occurs in emergency turns when the steering wheel is turned sharply, bumpy roads, and twisted roads.

[0057] Specific motion analysis includes the following situations:

[0058] S1) positive x-, y-, and z-translations;

[0059] S2) positive Rx rotation, Ry rotation, Rz rotation;

[0060] S3) positive x-translation + positive Rx / Ry / Rz rotation;

[0061] S4) positive y translation + positive Rx / Ry / Rz rotation;

[0062] S5) positive z translation + positive Rx / Ry / Rz rotation;

[0063] S6) reverse x-, y-, and z-direction translation;

[0064] S7) reverse Rx rotation, Ry rotation, and Rz rotation;

[0065] S8) negative x-translation + positive Rx / Ry / Rz rotation;

[0066] S9) negative y translation + positive Rx / Ry / Rz rotation;

[0067] S10) Reverse z-translation + forward Rx / Ry / Rz rotation;

[0068] S11) positive x-translation + negative Rx / Ry / Rz rotation;

[0069] S12) positive y translation + negative Rx / Ry / Rz rotation;

[0070] S13) Forward z translation + reverse Rx / Ry / Rz rotation.

[0071] Example:

[0072] During the design and development of a heavy-duty commercial vehicle, one of the main selling models, it was equipped with a brand new engine, Model A. However, the market demanded another engine, Model B. The method of the present invention was used to perform design verification and determine the final development plan:

[0073] 1. Input the static boundaries of the powertrain and surrounding accessories. First, preliminarily determine the replacement engine position and the vibration damping pad limit dimensions. The vibration damping pad z-axis limit dimension is ±20mm, meaning that the engine can move up and down a maximum of 20mm in this preliminary solution.

[0074] 2. Determine the placement of the powertrain mount vibration damping pads. Based on the ±20mm limit of the vibration damping pads, translate the engine upward by 20mm in the z-direction to determine the rear motion boundary.

[0075] 3. Design the vibration damping pad limit structure dimensions, adjust the vibration damping pad layout and the internal and external frame gap dimensions to control the powertrain's motion boundary dimensions. Because the B-type engine has a taller and larger cylinder head than the A-type engine, it interferes with the cab floor. Therefore, the cab floor interference analysis was focused on. Using 3D design software to verify the interference between this boundary and the cab floor, the software automatically calculates the interference location and dimensions, revealing a 3mm interference between the engine lifting lug at the top of the cylinder head and the cab floor.

[0076] 4. Perform a kinematic analysis of the static boundaries of the powertrain and surrounding accessories. This analysis suggests raising the cab floor and lowering the engine height. The ultimate goal is to increase the distance between the engine and the cab floor when the engine reaches its maximum upward position.

[0077] 5. Check the clearance between the powertrain's rear boundary and surrounding vehicle components. Taking into account the development costs and cycles of the cab floor and engine accessories, a plan was adopted to lower the engine height after review to ensure that the engine's rear boundary did not interfere with the cab floor.

[0078] 6. According to the verification results, the z-axis limit size of the vibration damping pad is changed from ±20mm to ±10mm. The maximum boundary limiting the upward movement of the engine still retains a 7mm gap with the cab floor. The dynamic motion boundary size of the powertrain is output to provide a boundary for the design of the surrounding parts of the vehicle. At the same time, the design plan for the layout position and limit size of the vibration damping pad is output to solidify the design plan.

[0079] The above description is merely an example of the embodiments of the present invention and does not constitute any form of limitation to the present invention. The scope of protection of the present invention shall be based on the claims and is not limited by the above specific embodiments. Any simple modification or equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention shall fall within the scope of protection of the present invention.

Claims

1. A commercial vehicle powertrain motion limit design method, characterized in that: The specific steps include: 1) Input the static boundaries of the powertrain and surrounding accessories; 2) Determine the layout location of the powertrain suspension vibration damping pad; 3) Design the size of the vibration damping pad limit structure, requiring limit structures in the x, y, and z directions. Adjust the position of the vibration damping pad and the gap between the inner and outer frames to control the motion boundary size of the powertrain. 4) Perform motion analysis on the static boundaries of the powertrain and surrounding accessories, including translation in the x, y, and z directions, rotation in the Rx, Ry, and Rz directions, and various combinations of x, y, and z translations and Rx, Ry, and Rz rotations; 5) Check the clearance between the boundary of the powertrain movement and the surrounding parts of the vehicle. If it does not meet the vehicle layout requirements, modify the vibration damping pad layout position or limit size, and re-perform the powertrain movement analysis and check the surrounding parts of the vehicle; 6) Output the dynamic motion boundary size of the powertrain to provide a boundary for the design of peripheral parts of the vehicle, and at the same time output the design plan of the vibration damping pad layout position and limit size.

2. The commercial vehicle powertrain motion limit design method according to claim 1, characterized in that: In step 1), the powertrain and surrounding accessories include an engine, a gearbox, and a motor.

3. The commercial vehicle powertrain motion limit design method according to claim 1, characterized in that: In step 2), four vibration damping pads are provided, and the arrangement schemes of the vibration damping pads include three methods: "both sides of the front end of the engine cylinder block + both sides of the engine flywheel housing", "both sides of the front end of the engine cylinder block + both sides of the gearbox clutch housing", and "both sides of the front end of the engine cylinder block + both sides of the rear end of the gearbox".

4. The commercial vehicle powertrain motion limit design method according to claim 1, characterized in that: In step 3), the vibration damping pad is a vibration damping pad with a wedge-shaped composite structure, which is the structure of patent CN2214164720U.

5. The commercial vehicle powertrain motion limit design method according to claim 3, characterized in that: In step 3), adjusting the arrangement position of the vibration damping pad is adjusting three different arrangement schemes to control the motion boundary size of the powertrain; Among them, the powertrain motion boundary size of the "two sides of the front end of the engine cylinder block + two sides of the engine flywheel housing" layout scheme is the largest, the powertrain motion boundary size of the "two sides of the front end of the engine cylinder block + two sides of the transmission clutch housing" layout scheme is moderate, and the powertrain motion boundary size of the "two sides of the front end of the engine cylinder block + two sides of the rear end of the transmission" layout scheme is the smallest.

6. The commercial vehicle powertrain motion limit design method according to claim 1, characterized in that: In step 4), the motion analysis further includes forward / reverse x, y, z translation or Rx, Ry, Rz rotation, and various combinations of forward / reverse x, y, z translation and forward / reverse Rx, Ry, Rz rotation.

7. The commercial vehicle powertrain motion limit design method according to claim 6, characterized in that: In step 4), the motion analysis is performed for the following situations: S1) positive x-, y-, and z-translations; S2) positive Rx rotation, Ry rotation, Rz rotation; S3) positive x-translation + positive Rx / Ry / Rz rotation; S4) positive y translation + positive Rx / Ry / Rz rotation; S5) Positive z translation + positive Rx / Ry / Rz rotation.

8. The commercial vehicle powertrain motion limit design method according to claim 6, characterized in that: In step 4), the motion analysis also includes the following situations: S6) reverse x-, y-, and z-direction translation; S7) reverse Rx rotation, Ry rotation, and Rz rotation; S8) negative x-translation + positive Rx / Ry / Rz rotation; S9) negative y translation + positive Rx / Ry / Rz rotation; S10) Reverse z-translation + positive Rx / Ry / Rz rotation; S11) positive x-translation + negative Rx / Ry / Rz rotation; S12) positive y translation + negative Rx / Ry / Rz rotation; S13) Forward z translation + reverse Rx / Ry / Rz rotation.

9. The commercial vehicle powertrain motion limit design method according to claim 1, characterized in that: In step 5), the vehicle peripheral parts include the cab floor, sound insulation board, front and rear cab suspension, cab flip mechanism, frame and its tube beam, cross beam and basin beam, front axle I-beam, front suspension, anti-roll bar, cooling module and its air pipeline, steering cylinder and its pipeline, exhaust butterfly valve and after-treatment air pipeline, intake pipeline and air filter, transmission control mechanism, air compressor air pipeline, fuel or gas pipeline, and peripheral electrical wiring harness pipeline.

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