Few-leaf-spring suspension system for sightseeing vehicle

Abstract

The invention provides a few-leaf-spring suspension system for a sightseeing vehicle, and belongs to the technical field of vehicle suspension parts, the few-leaf-spring suspension system for the sightseeing vehicle comprises a main steel plate spring assembly, an auxiliary steel plate spring assembly, a fixing assembly, an anti-loosening assembly and a damping vibration attenuation assembly; a variable cross-section section is arranged in the middle of the main steel plate spring assembly, and the thickness of the variable cross-section section is gradually reduced from the center to the two ends; the length of the auxiliary steel plate spring assembly is smaller than that of the main steel plate spring assembly, and the auxiliary steel plate spring assembly is fixedly connected with the main steel plate spring assembly through a center bolt. The fixing assemblies are arranged at the two ends of the main steel plate spring assembly, and the anti-loosening assemblies are arranged in the fixing assemblies. The damping vibration attenuation assembly comprises a high-frequency damper, a medium-frequency damper and a low-frequency damper; the problem that in the prior art, a few-leaf-spring suspension system of a sightseeing vehicle is insufficient in vibration reduction performance can be solved.

Description

Technical Field

[0001] The invention belongs to the technical field of vehicle suspension parts, and in particular relates to a suspension system with few leaf springs for a sightseeing vehicle. Background Art

[0002] As an important part of urban rail transit, sightseeing cars play an important role in urban tourism. Compared with ordinary passenger cars, sightseeing cars need to have good mechanical properties and comfort in addition to meeting general passenger performance requirements. Among them, the suspension system is particularly important in the design of sightseeing cars as a key component that bears the weight of the vehicle body and ensures vehicle safety and ride comfort.

[0003] Traditional sightseeing cars use multi-leaf spring suspension systems, which are characterized by complex structures and high costs. With the advancement of technology, the less-leaf spring suspension system has gradually become the mainstream choice for sightseeing car suspension systems due to its simple structure, light weight and low cost. However, since the vibration reduction performance of the less-leaf spring suspension system is limited, there are still some problems in practical applications.

[0004] First, the vibration characteristics of the leaf spring itself are difficult to meet the vibration reduction requirements of the full frequency band. Due to its high stiffness, its natural frequency is generally high and it cannot effectively absorb low-frequency vibrations; and when subjected to high-frequency excitation, its own flexural deformation will also cause a large acceleration response, causing discomfort to passengers.

[0005] Secondly, the connection method between the leaf spring and the vehicle body will also affect the vibration reduction effect of the suspension system. Traditional rigid connections are prone to cause local stress concentration, while flexible connections are difficult to ensure position stability. Therefore, how to strike a balance between the rigid and flexible connection characteristics has also become an urgent problem to be solved.

[0006] Thirdly, the selection of dampers in the suspension system is also the key. Since sightseeing cars need to take into account both riding comfort and driving stability, a single damping characteristic is difficult to meet the needs of all working conditions. Therefore, the design of adjustable or multi-stage damping has become a hot topic in current research.

[0007] In summary, the existing sightseeing vehicle leaf spring suspension system has the problem of insufficient vibration reduction performance. Summary of the invention

[0008] In view of this, the present invention provides a suspension system with few leaf springs for a sightseeing vehicle, which can solve the problem of insufficient vibration reduction performance of the suspension system with few leaf springs for sightseeing vehicles in the prior art.

[0009] The present invention is achieved in that:

[0010] The present invention provides a leaf spring-less suspension system for a sightseeing vehicle, which comprises a main leaf spring assembly, a secondary leaf spring assembly, a fixing assembly, an anti-loosening assembly and a damping vibration reduction assembly; a variable cross-section section is provided in the middle of the main leaf spring assembly, and the thickness of the variable cross-section section gradually decreases from the center to both ends; the length of the secondary leaf spring assembly is shorter than that of the main leaf spring assembly, and the secondary leaf spring assembly is fixedly connected to the main leaf spring assembly by a central bolt; the fixing assembly is arranged at both ends of the main leaf spring assembly, and the anti-loosening assembly is arranged inside the fixing assembly; the damping vibration reduction assembly It includes a high-frequency damper, a medium-frequency damper and a low-frequency damper; the high-frequency damper is arranged in the middle of the main leaf spring assembly, the medium-frequency damper is arranged at the front end of the main leaf spring assembly, and the low-frequency damper is arranged at the rear end of the main leaf spring assembly; the damping coefficient of the high-frequency damper is 15,000 Newtons per meter per second, which is used to attenuate vibrations above 20 Hz; the damping coefficient of the medium-frequency damper is 10,000 Newtons per meter per second, which is used to attenuate vibrations of 5 to 20 Hz; the damping coefficient of the low-frequency damper is 5,000 Newtons per meter per second, which is used to attenuate vibrations below 5 Hz.

[0011] The technical effects of the leaf spring-less suspension system for sightseeing vehicles provided by the present invention are as follows: First, the main leaf spring adopts a variable cross-section design, and the thickness gradually decreases from the center to the two ends. This structure can make the stress distribution more uniform, avoid stress concentration, and increase the service life of the spring. At the same time, by introducing the auxiliary leaf spring to form a double-layer leaf spring structure, not only the overall stiffness is increased, but also the contact pressure distribution between the main and auxiliary springs can be optimized, further improving the vibration reduction performance.

[0012] Secondly, the suspension system adopts a three-stage damper design (high frequency, medium frequency and low frequency). By reasonably determining the installation position of each damper, they can effectively attenuate vibrations in different frequency bands, avoiding the occurrence of resonance, thereby ensuring the vibration reduction effect of the full frequency band.

[0013] Thirdly, a series of measures have been taken in terms of fixing the assembly and installing the damper. On the one hand, a flexible rubber gasket and U-shaped clamping plate connection method is adopted to ensure position stability and effectively isolate direct contact between metals, reducing local stress concentration. On the other hand, by optimizing the contact area relationship between the damper mounting seat and the main leaf spring, sufficient load-bearing capacity is ensured to prevent premature wear and failure.

[0014] In general, the present invention has carried out targeted optimization on the deficiencies in the prior art while ensuring the overall vibration reduction performance of the sightseeing vehicle suspension system, and has achieved significant progress in structural design, connection method and damping characteristics, thus solving the problem of insufficient vibration reduction performance of the sightseeing vehicle leaf spring suspension system in the prior art.

[0015] On the basis of the above technical solution, the leaf-less spring suspension system for sightseeing vehicles of the present invention can also be improved as follows:

[0016] Among them, the main leaf spring assembly includes a main spring body, a main spring eye and a reinforcing pad. The main spring eyes are arranged at both ends of the main spring body, and the reinforcing pad is fixed at the connection between the main spring body and the main spring eye; the variable cross-section section is located in the middle of the main spring body, and its length accounts for 30 to 40% of the total length of the main spring body.

[0017] Furthermore, the auxiliary leaf spring assembly includes an auxiliary spring body and a center positioning sleeve, the auxiliary spring body is an arc-shaped structure, and the center positioning sleeve is fixed to the middle of the auxiliary spring body; both ends of the auxiliary spring body are abutted against the main leaf spring assembly to form a double-layer leaf spring structure.

[0018] Furthermore, the fixing assembly includes a fixing seat, a rubber pad and a U-shaped clamp. The fixing seat is a square structure with a rubber pad provided on the inner side. The rubber pad is tightly pressed against the main leaf spring assembly. The U-shaped clamp is sleeved on the outer side of the main leaf spring assembly and fixedly connected to the fixing seat by a connecting bolt assembly.

[0019] Furthermore, the high-frequency damper includes a high-frequency damping cylinder, a high-frequency damping piston and a high-frequency damping oil. The high-frequency damping cylinder is provided with a high-frequency damping chamber, the high-frequency damping chamber is filled with the high-frequency damping oil, and the high-frequency damping piston penetrates the high-frequency damping chamber; the high-frequency damping piston is provided with a high-frequency damping hole, and the diameter of the high-frequency damping hole is 2 mm.

[0020] Furthermore, the intermediate frequency damper includes an intermediate frequency damping cylinder, an intermediate frequency damping piston and an intermediate frequency damping oil. The intermediate frequency damping cylinder is provided with an intermediate frequency damping chamber, the intermediate frequency damping chamber is filled with the intermediate frequency damping oil, and the intermediate frequency damping piston passes through the intermediate frequency damping chamber; the intermediate frequency damping piston is provided with an intermediate frequency damping hole, and the diameter of the intermediate frequency damping hole is 3 mm.

[0021] Furthermore, the low-frequency damper includes a low-frequency damping cylinder, a low-frequency damping piston and a low-frequency damping oil. A low-frequency damping chamber is provided in the low-frequency damping cylinder, the low-frequency damping chamber is filled with the low-frequency damping oil, and the low-frequency damping piston passes through the low-frequency damping chamber; a low-frequency damping hole is provided on the low-frequency damping piston, and the diameter of the low-frequency damping hole is 4 mm.

[0022] Furthermore, the connecting bolt assembly includes a first connecting bolt and a second connecting bolt, the first connecting bolt is arranged on both sides of the fixing seat and passes through the main leaf spring assembly; the second connecting bolt is arranged in the middle of the U-shaped clamp and is connected to the anti-loosening assembly.

[0023] Among them, the anti-loosening assembly includes a sliding mechanism, a clamping mechanism and an operating mechanism; the sliding mechanism is arranged inside the U-shaped clamp, the clamping mechanism connects the sliding mechanism and the second connecting bolt, and the operating mechanism is fixed to the outer end of the clamping mechanism; the sliding mechanism includes a slide groove body and a slider assembly, the slide groove body is opened on the inner wall of the U-shaped clamp, and the slider assembly is slidably arranged in the slide groove body; the slider assembly includes two symmetrically arranged sliding blocks, and the sliding blocks are fixedly connected by a connecting ring.

[0024] Among them, the high-frequency damper, the medium-frequency damper and the low-frequency damper are all fixedly connected to the main leaf spring assembly through the damper mounting seat, and the damper mounting seat is connected to the main leaf spring assembly through high-strength bolts; a rubber vibration isolation pad is provided between the damper mounting seat and the main leaf spring assembly to prevent metal contact between the damper and the main leaf spring assembly.

[0025] In order to better ensure the shock absorption effect of the leaf spring suspension system for sightseeing vehicles, the geometric relationship between multiple components is also limited by a relationship-limited equation group. The relationship-limited equation group is described in detail as follows:

[0026] 1. Gradual thickness relationship of the variable section of the main leaf spring assembly:

[0027]

[0028] Wherein, h(x) is the thickness at the distance x from the center point, in millimeters; h0 is the maximum thickness at the center point, ranging from 12 to 15 mm; L is the half length of the variable section segment, ranging from 200 to 250 mm; α is the thickness change rate coefficient, ranging from 0.3 to 0.4; x is the distance from the center point, ranging from 0 to L mm.

[0029] 2. Contact pressure distribution relationship between main and auxiliary leaf springs:

[0030]

[0031] Where p(x) is the contact pressure at a distance x from the center point, in MPa; p0 is the maximum contact pressure at the center point, ranging from 3 to 5 MPa; β is the pressure attenuation coefficient, ranging from 0.01 to 0.015; F is the preload, ranging from 2000 to 3000 Newtons; r c is the contact radius, ranging from 25 to 30 mm.

[0032] 3. The optimal spacing relationship of the three dampers:

[0033]

[0034] Where d1, d2, d3 are the distances from the high-frequency, medium-frequency, and low-frequency dampers to the center point, respectively, in millimeters; ω1, ω2, ω3 are the characteristic frequencies corresponding to each damper, which are 20 Hz, 12.5 Hz, and 5 Hz, respectively.

[0035] 4. Relationship between the contact area between the damper mounting seat and the main leaf spring:

[0036]

[0037] In the formula, A c is the contact area, in square millimeters; A b is the cross-sectional area of ​​the main leaf spring, in square millimeters; γ is the area ratio coefficient, ranging from 1.2 to 1.5; F d is the damping force, in Newton; F s is the spring force in Newtons.

[0038] 5. Relationship between compression and pressure of rubber pad:

[0039] δ=k1P+k2P 2 +k3ln(1+P);

[0040] Wherein, δ is the compression amount, in millimeters; P is the pressure, in megapascals; k1, k2, and k3 are material property coefficients obtained through experiments.

[0041] The experimental steps are as follows:

[0042] 1. Carry out compression test on rubber pad on universal material testing machine;

[0043] 2. Record the compression data points under different pressures (P i ,δ i );

[0044] 3. Use the least squares method to fit the coefficients k1, k2, and k3.

[0045] 6.Contact stress distribution between U-shaped splint and fixed seat:

[0046]

[0047] Wherein, σ(r) is the contact stress at the radial distance r, in MPa; σ0 is the maximum stress at the center, ranging from 150 to 200 MPa; τ0 is the shear stress, ranging from 30 to 50 MPa; R is the radius of the contact area, in millimeters; r is the radial distance of the calculation point, in millimeters.

[0048] Equation principle explanation:

[0049] 1. The variable section thickness equation adopts the quadratic function form. This is because: the quadratic function can ensure a smooth transition at the end; the stress distribution law conforms to the parabolic characteristics; and the manufacturing process is easy to implement.

[0050] 2. The contact pressure distribution equation contains two terms: the exponential term describes the law of pressure attenuation with distance; the Gaussian term describes the local pressure distribution caused by the preload force; the superposition of the two terms is more consistent with the actual contact state.

[0051] 3. The damper spacing relationship is based on the principle of vibration transmission: the square root proportional relationship of frequency is derived from the wave equation; it ensures that the vibration in each frequency band can be effectively attenuated; and avoids resonance.

[0052] 4. The contact area relationship is in the form of a power function: the 0.75 power comes from Hertz contact theory; the nonlinear effect of load on contact area is considered; the coefficient γ is introduced to compensate for installation errors.

[0053] 5. The rubber compression relationship contains three terms: the linear term represents the initial elastic deformation; the quadratic term represents the large deformation effect; and the logarithmic term represents the hardening characteristics of the material.

[0054] 6. Contact stress distribution equation: The first term is derived from Hertz contact theory; the second term takes into account the influence of shear stress; it more accurately describes the complex stress state.

[0055] Compared with the prior art, the beneficial effects of the leaf spring suspension system for sightseeing vehicles provided by the present invention are as follows: first, the main leaf spring adopts a variable cross-section design, and the thickness gradually decreases from the center to the two ends. This structure can make the stress distribution more uniform, avoid stress concentration, and increase the service life of the spring. At the same time, by introducing the auxiliary leaf spring to form a double-layer leaf spring structure, not only the overall stiffness is increased, but also the contact pressure distribution between the main and auxiliary springs can be optimized, further improving the vibration reduction performance.

[0056] Secondly, the suspension system adopts a three-stage damper design (high frequency, medium frequency and low frequency). By reasonably determining the installation position of each damper, they can effectively attenuate vibrations in different frequency bands, avoiding the occurrence of resonance, thereby ensuring the vibration reduction effect of the full frequency band.

[0057] Thirdly, a series of measures have been taken in terms of fixing the assembly and installing the damper. On the one hand, a flexible rubber gasket and U-shaped clamping plate connection method is adopted to ensure position stability and effectively isolate direct contact between metals, reducing local stress concentration. On the other hand, by optimizing the contact area relationship between the damper mounting seat and the main leaf spring, sufficient load-bearing capacity is ensured to prevent premature wear and failure.

[0058] In general, the present invention has carried out targeted optimization on the deficiencies in the prior art while ensuring the overall vibration reduction performance of the sightseeing vehicle suspension system, and has achieved significant progress in structural design, connection method and damping characteristics, thus solving the problem of insufficient vibration reduction performance of the sightseeing vehicle leaf spring suspension system in the prior art. BRIEF DESCRIPTION OF THE DRAWINGS

[0059] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings required for use in the description of the embodiments of the present invention will be briefly introduced below. Obviously, the accompanying drawings in the following description are only some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying creative labor.

[0060] Figure 1 It is a structural schematic diagram of a leaf-less spring suspension system for a sightseeing vehicle;

[0061] In the accompanying drawings, the components represented by the reference numerals are listed as follows:

[0062] 10. Main leaf spring assembly; 11. Main spring body; 12. Main spring eye; 13. Reinforcement pad; 20. Auxiliary leaf spring assembly; 21. Auxiliary spring body; 22. Center positioning sleeve; 30. Fixing assembly; 31. Fixing seat; 32. Rubber pad; 33. U-shaped clamp; 40. Anti-loosening assembly; 50. Damping and vibration reduction assembly; 51. High-frequency damper; 511. High-frequency damping cylinder; 512 , high-frequency damping piston; 513, high-frequency damping chamber; 52, medium-frequency damper; 521, medium-frequency damping cylinder; 522, medium-frequency damping piston; 523, medium-frequency damping chamber; 53, low-frequency damper; 531, low-frequency damping cylinder; 532, low-frequency damping piston; 533, low-frequency damping chamber; 60, variable cross-section section; 70, connecting bolt assembly; 71, first connecting bolt; 72, second connecting bolt. DETAILED DESCRIPTION

[0063] In order to make the purpose, technical solution and advantages of the embodiments of the present invention more clear, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention.

[0064] like Figure 1As shown in the figure, it is an embodiment of a leaf spring suspension system for a sightseeing vehicle provided by the present invention. In this embodiment, it includes a main leaf spring assembly 10, a secondary leaf spring assembly 20, a fixing assembly 30, an anti-loosening assembly 40 and a damping vibration reduction assembly 50; a variable cross-section section 60 is provided in the middle of the main leaf spring assembly, and the thickness of the variable cross-section section gradually decreases from the center to the two ends; the length of the secondary leaf spring assembly is shorter than that of the main leaf spring assembly, and the secondary leaf spring assembly is fixedly connected to the main leaf spring assembly by a central bolt; the fixing assembly is arranged at both ends of the main leaf spring assembly, and the anti-loosening assembly is arranged at the fixing assembly Internally; the damping vibration reduction assembly includes a high-frequency damper 51, a medium-frequency damper 52 and a low-frequency damper 53; the high-frequency damper is arranged in the middle of the main leaf spring assembly, the medium-frequency damper is arranged at the front end of the main leaf spring assembly, and the low-frequency damper is arranged at the rear end of the main leaf spring assembly; the damping coefficient of the high-frequency damper is 15,000 Newtons per meter per second, which is used to attenuate vibrations above 20 Hz; the damping coefficient of the medium-frequency damper is 10,000 Newtons per meter per second, which is used to attenuate vibrations from 5 to 20 Hz; the damping coefficient of the low-frequency damper is 5,000 Newtons per meter per second, which is used to attenuate vibrations below 5 Hz.

[0065] Among them, in the above technical scheme, the main leaf spring assembly includes a main spring body 11, a main spring eye 12 and a reinforcing pad 13. The main spring eyes are arranged at both ends of the main spring body, and the reinforcing pad is fixed at the connection between the main spring body and the main spring eye; the variable cross-section section is located in the middle of the main spring body, and the length accounts for 30 to 40% of the total length of the main spring body.

[0066] Furthermore, in the above technical solution, the auxiliary leaf spring assembly includes an auxiliary spring body 21 and a center positioning sleeve 22, the auxiliary spring body is an arc-shaped structure, and the center positioning sleeve is fixed to the middle of the auxiliary spring body; both ends of the auxiliary spring body are abutted against the main leaf spring assembly to form a double-layer leaf spring structure.

[0067] Furthermore, in the above technical solution, the fixing assembly includes a fixing seat 31, a rubber pad 32 and a U-shaped clamp 33. The fixing seat is a square structure with a rubber pad provided on the inner side, and the rubber pad is tightly pressed against the main leaf spring assembly; the U-shaped clamp is sleeved on the outer side of the main leaf spring assembly and fixedly connected to the fixing seat by a connecting bolt assembly.

[0068] Furthermore, in the above technical solution, the high-frequency damper includes a high-frequency damping cylinder 511, a high-frequency damping piston 512 and high-frequency damping oil. A high-frequency damping chamber 513 is provided in the high-frequency damping cylinder. The high-frequency damping chamber is filled with high-frequency damping oil. The high-frequency damping piston penetrates the high-frequency damping chamber. A high-frequency damping hole is provided on the high-frequency damping piston, and the diameter of the high-frequency damping hole is 2 mm.

[0069] Furthermore, in the above technical solution, the medium frequency damper includes a medium frequency damping cylinder 521, a medium frequency damping piston 522 and medium frequency damping oil. A medium frequency damping chamber 523 is provided in the medium frequency damping cylinder. The medium frequency damping chamber is filled with medium frequency damping oil. The medium frequency damping piston penetrates the medium frequency damping chamber. A medium frequency damping hole is provided on the medium frequency damping piston, and the diameter of the medium frequency damping hole is 3 mm.

[0070] Furthermore, in the above technical solution, the low-frequency damper includes a low-frequency damping cylinder 531, a low-frequency damping piston 532 and a low-frequency damping oil. A low-frequency damping chamber 533 is provided in the low-frequency damping cylinder. The low-frequency damping chamber is filled with low-frequency damping oil. The low-frequency damping piston penetrates the low-frequency damping chamber. A low-frequency damping hole is provided on the low-frequency damping piston, and the diameter of the low-frequency damping hole is 4 mm.

[0071] Furthermore, in the above technical solution, the connecting bolt assembly 70 includes a first connecting bolt 71 and a second connecting bolt 72. The first connecting bolt is arranged on both sides of the fixing seat and passes through the main leaf spring assembly; the second connecting bolt is arranged in the middle of the U-shaped clamp and is connected to the anti-loosening assembly.

[0072] Among them, in the above technical scheme, the anti-loosening assembly includes a sliding mechanism, a clamping mechanism and an operating mechanism; the sliding mechanism is arranged inside the U-shaped clamp, the clamping mechanism connects the sliding mechanism and the second connecting bolt, and the operating mechanism is fixed to the outer end of the clamping mechanism; the sliding mechanism includes a slide groove body and a slider assembly, the slide groove body is opened on the inner wall of the U-shaped clamp, and the slider assembly is slidably arranged in the slide groove body; the slider assembly includes two symmetrically arranged sliding blocks, and the sliding blocks are fixedly connected by a connecting ring.

[0073] Among them, in the above technical scheme, the high-frequency damper, the medium-frequency damper and the low-frequency damper are all fixedly connected to the main leaf spring assembly through the damper mounting seat, and the damper mounting seat is connected to the main leaf spring assembly through high-strength bolts; a rubber vibration isolation pad is provided between the damper mounting seat and the main leaf spring assembly to prevent metal contact between the damper and the main leaf spring assembly.

[0074] The main leaf spring assembly adopts a variable cross-section design, with a larger thickness in the middle and gradually thinner at both ends. This structure can make the spring stress distribution more uniform, avoid stress concentration, and increase service life. The thickness change conforms to The quadratic function relationship is as follows. Among them, h(x) is the thickness at the distance x from the center point, in millimeters; h0 is the maximum thickness at the center point, ranging from 12-15 mm; L is the half length of the variable section, ranging from 200-250 mm; α is the thickness change rate coefficient, ranging from 0.3-0.4; x is the distance from the center point, ranging from 0-L mm.

[0075] The main leaf spring assembly and the auxiliary leaf spring assembly are connected by a central bolt to form a double-layer leaf spring structure. The contact pressure distribution can be described as Where p(x) is the contact pressure at a distance x from the center point, in MPa; p0 is the maximum contact pressure at the center point, ranging from 3 to 5 MPa; β is the pressure attenuation coefficient, ranging from 0.01 to 0.015; F is the preload, ranging from 2000 to 3000 Newtons; r c is the contact radius, ranging from 25 to 30 mm. This formula contains two terms: the exponential term describes the law of pressure attenuation with distance; the Gaussian term describes the local pressure distribution caused by the preload. The superposition of the two terms can more accurately describe the actual contact state.

[0076] The suspension system uses three-stage dampers, namely high-frequency, medium-frequency and low-frequency dampers. Their installation positions should meet Among them, d1, d2, d3 are the distances from the high-frequency, medium-frequency, and low-frequency dampers to the center point, respectively, in millimeters; ω1, ω2, ω3 are the characteristic frequencies corresponding to each damper, which are 20Hz, 12.5Hz, and 5Hz, respectively. This spacing relationship is derived from the principle of vibration transmission, which can ensure that the vibration of each frequency band is effectively attenuated to avoid resonance.

[0077] The contact area between the damper mounting seat and the main leaf spring should meet Among them, A c is the contact area, in square millimeters; A b is the cross-sectional area of ​​the main leaf spring, in square millimeters; γ is the area ratio coefficient, ranging from 1.2 to 1.5; F d is the damping force, in Newton; F s is the spring force in Newtons. This relationship is derived from the Hertz contact theory, which takes into account the nonlinear effect of the load on the contact area and introduces the coefficient γ to compensate for installation errors.

[0078] The relationship between the compression and pressure of the rubber pad in the fixed assembly is δ=k1P+k2P 2 +k3ln(1+P). By performing compression test on the rubber pad on a universal material testing machine, the compression data points under different pressures (P i ,δ i ), the coefficients k1, k2, and k3 are obtained by least squares fitting. This relationship contains three terms: the linear term represents the initial elastic deformation, the quadratic term represents the large deformation effect, and the logarithmic term represents the material hardening characteristics.

[0079] Finally, the contact stress distribution between the U-shaped clamp and the fixed seat can be described as Among them, σ(r) is the contact stress at the radial distance r, in MPa; σ0 is the maximum stress at the center, ranging from 150 to 200 MPa; τ0 is the shear stress, ranging from 30 to 50 MPa; R is the radius of the contact area, in millimeters; r is the radial distance of the calculation point, in millimeters. The first term of this formula is derived from Hertz contact theory, and the second term takes into account the influence of shear stress, which can more accurately describe complex stress states.

[0080] Embodiment 1:

[0081] This embodiment focuses on the main component structure, materials and manufacturing process of the leaf spring-less suspension system for sightseeing vehicles and describes them in detail.

[0082] 1. Main leaf spring assembly

[0083] The main leaf spring assembly is the core component of the suspension system, and its structural design directly affects the vibration reduction performance of the entire system. In order to meet the full-band vibration reduction requirements of the sightseeing car, this embodiment adopts a variable cross-section design.

[0084] The main spring body is made of high-quality spring steel plate (60Si2Mn) with a thickness of 12-15 mm. The thickness of the steel plate is larger in the middle and gradually thinner at both ends to meet the The thickness variation law of the spring is shown in Figure 1. Among them, h0 is 14 mm, L is 225 mm, and α is 0.35. This thickness gradient in the form of a quadratic function can ensure a smooth transition at both ends of the spring, avoid stress concentration, and increase service life.

[0085] Spring eyes are welded at both ends of the spring body for connection with the frame. In order to enhance the strength of the spring eye, a reinforcing plate (45# steel, 6 mm thick) is also provided at the connection between the spring body and the spring eye. The reinforcing plate is fixed to the spring body through welding technology to ensure the reliability of the overall structure.

[0086] 2. Auxiliary leaf spring assembly

[0087] The auxiliary leaf spring assembly is made of 60Si2Mn spring steel plate with a thickness of 10 mm. Its body adopts an arc design, presenting a "U"-shaped structure, and its length is slightly smaller than the main leaf spring assembly. A central positioning sleeve is fixed in the middle of the spring body through a welding process, which is used to cooperate with the central bolt of the main leaf spring assembly to form a double-layer spring structure.

[0088] The two ends of the auxiliary leaf spring are in contact with the upper surface of the main leaf spring assembly, and the force is transmitted through the preload. This double-layer leaf spring structure can not only improve the overall stiffness, but also optimize the contact pressure distribution between the main and auxiliary springs, thereby further improving the vibration reduction performance of the entire suspension system.

[0089] 3.Fix the assembly

[0090] The fixing assembly is mainly composed of three parts: the fixing seat, the rubber pad and the U-shaped clamp. The fixing seat is cast with 45# steel and has a square structure; a 15mm thick rubber pad (rubber hardness 80°) is set inside, which is in direct contact with the main leaf spring assembly; the U-shaped clamp is also made of 45# steel, fixed to the fixing seat by connecting bolts, and clamps the main leaf spring assembly.

[0091] This flexible connection method can effectively absorb the displacement and deformation of the spring, avoiding the problem of local stress concentration that may occur under rigid connection. At the same time, the damping characteristics of the rubber pad can further improve the overall vibration reduction performance. The preload force between the fixed seat, rubber pad and U-shaped clamp directly determines the stiffness characteristics of the system and needs to be optimized according to the actual working conditions.

[0092] 4. Anti-loosening assembly

[0093] The anti-loosening assembly is arranged inside the U-shaped clamping plate, and mainly consists of three parts: a sliding mechanism, a clamping mechanism, and an operating mechanism. The sliding mechanism includes a sliding groove body arranged on the inner wall of the U-shaped clamping plate, and two symmetrical sliding blocks slidingly arranged therein. This sliding structure can ensure that the U-shaped clamping plate can perform a small displacement along the axial direction of the main leaf spring assembly, effectively preventing loosening caused by factors such as temperature changes and vibrations.

[0094] The clamping mechanism connects the sliding block with the second connecting bolt fixed in the middle of the U-shaped clamping plate. By adjusting the preload of the bolt, the force state of the sliding mechanism can be controlled to further enhance the anti-loosening performance. The operating mechanism is set at the outer end of the clamping mechanism, and the staff can use it to adjust the preload to meet the needs of different working conditions.

[0095] The design of the anti-loosening assembly not only ensures the position stability of the suspension system during long-term use, but also enables fine-tuning at any time according to actual working conditions, thereby improving the reliability of the entire system.

[0096] 5. Damping vibration reduction assembly

[0097] The damping and vibration reduction assembly consists of three parts: high-frequency damper, medium-frequency damper and low-frequency damper, which are installed in the middle, front and rear of the main leaf spring assembly respectively. This multi-stage damping design can effectively cover the full-band vibration generated by the sightseeing car under various working conditions.

[0098] The internal structure of the high-frequency damper is as follows: the cylinder body is cast with 45# steel and is equipped with a high-frequency damping cavity with a diameter of 80 mm; the piston is made of 45# steel and has a high-frequency damping hole with a diameter of 2 mm, which cooperates with the high-frequency damping oil (viscosity 0.3 Pa·s) in the cavity to provide a damping coefficient of 15,000 Newtons per meter per second, which is used to attenuate high-frequency vibrations above 20 Hz.

[0099] The structure of the medium-frequency damper is similar. The cylinder diameter is 90 mm, and there is a medium-frequency damping hole with a diameter of 3 mm on the piston. Together with the medium-frequency damping oil (viscosity 0.5 Pa·s), it provides a damping coefficient of 10,000 Newtons per meter per second, which is used to attenuate medium-frequency vibrations of 5-20 Hz.

[0100] The low-frequency damper cylinder has a diameter of 100 mm and a 4 mm diameter low-frequency damping hole is opened on the piston, which together with the low-frequency damping oil (viscosity 0.8 Pa·s) provides a damping coefficient of 5000 Newtons per meter per second to attenuate low-frequency vibrations below 5 Hz.

[0101] The installation positions of the three dampers meet the requirements , where d1, d2, d3 are the distances from the high-frequency, medium-frequency, and low-frequency dampers to the center point, and ω1, ω2, ω3 are their characteristic frequencies, which are 20 Hz, 12.5 Hz, and 5 Hz, respectively. This spacing design can ensure that vibrations in each frequency band are effectively attenuated to avoid resonance.

[0102] In addition, the mounting bases of the three dampers are all made of 45# steel and connected to the main leaf spring assembly by high-strength bolts. A 5mm thick rubber vibration isolation pad is also set between the mounting base and the spring to isolate metal contact and prevent stress concentration.

[0103] Through the above-mentioned structural design and material selection, the sightseeing vehicle with less leaf spring suspension system of this embodiment not only ensures the overall vibration reduction performance, but also further optimizes the strength, reliability and economy of each component, laying a solid foundation for the widespread application of sightseeing vehicles.

[0104] Embodiment 2:

[0105] This embodiment focuses on analyzing the relationship between the various components of the leaf spring suspension system for sightseeing vehicles, and provides a specific value range to ensure that the entire system works in an optimal state.

[0106] 1. Variable cross-section design of main leaf spring assembly

[0107] The thickness variation law of the main leaf spring assembly satisfies After analysis, calculation and experimental verification, the value range of each parameter in the formula is as follows: h0 = 14 mm, L = 225 mm, α = 0.35.

[0108] This thickness gradient in the form of a quadratic function can ensure a smooth transition at both ends of the spring, making the stress distribution more uniform, avoiding stress concentration, and increasing the service life. The center thickness h0 is 14 mm, which takes into account the feasibility of the manufacturing process while meeting the overall stiffness requirements. The length of the variable section L is 225 mm, accounting for about 40% of the total length of the spring body, which can achieve the greatest optimization effect. The thickness change rate coefficient α is 0.35, which reduces the thickness at both ends to 65% and 85% of the center thickness respectively, achieving a reasonable transition.

[0109] 2. Contact pressure distribution of main and auxiliary leaf springs

[0110] The contact pressure distribution between the main leaf spring assembly and the auxiliary leaf spring assembly can be Through analysis and experiments, the range of each parameter is as follows: p0 = 4 MPa, β = 0.012, F = 2500 Newton, r c =28 mm.

[0111] The first exponential function describes the law of contact pressure attenuation with distance. p0 = 4 MPa represents the maximum contact pressure at the center point. The pressure attenuation coefficient of β = 0.012 makes the pressure at 100 mm from the center drop to 1 / e of the initial value. The second Gaussian function reflects the local pressure distribution caused by the preload F = 2500 Newtons. The contact radius r c = 28 mm. This pressure distribution is conducive to optimizing the force transmission characteristics between the main spring and the auxiliary spring, and further improving the vibration reduction performance.

[0112] 3. Installation position of three-stage damper

[0113] The installation positions of the three dampers (high frequency, medium frequency and low frequency) should meet According to the vibration characteristics of the system, the characteristic frequencies of each damper are ω1 = 20 Hz, ω2 = 12.5 Hz and ω3 = 5 Hz respectively.

[0114] Through calculation, it can be obtained that the distance from the high-frequency damper to the center point is d1 = 150 mm, the distance from the medium-frequency damper to the center point is d2 = 240 mm, and the distance from the low-frequency damper to the center point is d3 = 400 mm. This spacing relationship can ensure that the vibration of each frequency band is effectively attenuated and avoid the occurrence of resonance.

[0115] 4. Contact area between damper mounting seat and main leaf spring

[0116] The contact area between the damper mounting seat and the main leaf spring should meet According to the test data, take γ = 1.35, where A b= 3600 square millimeters as the cross-sectional area of ​​the main leaf spring, F d =3000 Newtons is the damping force, F s = 30000 Newtons is the spring force.

[0117] By calculation, the required contact area A c = 800 square millimeters. This contact area relationship can not only meet the requirements of load-bearing capacity, but also effectively reduce contact stress and avoid premature wear. At the same time, a 5 mm thick rubber vibration isolation pad is also set between the damper mounting seat and the main leaf spring to further isolate the metal contact and prevent stress concentration.

[0118] 5. Relationship between compression and pressure of rubber pad

[0119] The relationship between the compression δ and the pressure P of the rubber pad in the fixed assembly can be expressed as δ=k1P+k2P 2 +k3ln(1+P) is used to describe the relationship. After experimental fitting, the values ​​of the coefficients are as follows: k1=0.05, k2=0.002, k3=0.03.

[0120] This relationship, which includes linear, quadratic and logarithmic terms, can accurately reflect the nonlinear mechanical properties of rubber materials under large deformation conditions. According to calculations, when the pressure is 4 MPa, the compression of the rubber pad is about 8 mm. This moderate compression can not only meet the stiffness requirements of the system, but also give full play to the damping characteristics of the rubber, further improving the vibration reduction performance.

[0121] 6.Contact stress distribution between U-shaped clamp and fixed seat

[0122] The contact stress distribution between the U-shaped clamp and the fixed seat can be According to the analysis and calculation, σ0 = 180 MPa, τ0 = 40 MPa, and R = 90 mm.

[0123] The first term represents the radial stress distribution, with the maximum stress in the center σ0 = 180 MPa, which decays parabolically with the increase of radius r; the second term describes the tangential stress distribution, τ0 = 40 MPa. The contact area radius R = 90 mm can ensure that the contact stress is within the allowable range and avoid failures caused by local stress concentration.

[0124] By defining the relationship between the above-mentioned components, the sightseeing car with less leaf spring suspension system of this embodiment, while satisfying the overall vibration reduction performance, further optimizes indicators such as structural strength, reliability and economy, ensuring stable and reliable operation of the system under various working conditions.

[0125] Specifically, the principle of the present invention is: the core technical principle of the sightseeing vehicle less leaf spring suspension system proposed by the present invention can be summarized as follows:

[0126] 1. Variable cross-section main leaf spring design. The main leaf spring has a larger thickness in the middle and gradually becomes thinner at both ends. This structure can make the spring stress distribution more uniform, avoid stress concentration, and increase service life. The quadratic function relationship is used to describe the variation of thickness along the length direction, where h(x) is the thickness at a distance x from the center point, h0 is the maximum thickness at the center point, L is the half length of the variable section, and α is the thickness variation coefficient. This quadratic function form can ensure a smooth transition at the end, conform to the parabolic characteristics of the actual stress distribution, and is also convenient for the realization of the manufacturing process.

[0127] 2. Double-layer leaf spring structure. The main leaf spring assembly and the auxiliary leaf spring assembly are connected by a central bolt to form a double-layer leaf spring structure. This design not only increases the overall stiffness, but also optimizes the contact pressure distribution between the main and auxiliary springs. The contact pressure can be It contains two items: the exponential term describes the pressure attenuation law with distance, and the Gaussian term describes the local pressure distribution caused by the preload. The superposition of the two items can more accurately reflect the actual contact state. Reasonably adjust these parameters, such as the maximum center pressure p0, pressure attenuation coefficient β, preload F and contact radius r c Etc., can further improve the coordination of the main and auxiliary springs, thereby optimizing the overall vibration reduction effect.

[0128] 3. Multi-stage damper design. The suspension system uses three-stage dampers (high frequency, medium frequency and low frequency). By reasonably determining the installation position of each damper, they can effectively attenuate vibrations in different frequency bands. The installation position should meet , where d1, d2, and d3 are the distances from each damper to the center point, and ω1, ω2, and ω3 are their characteristic frequencies. This spacing relationship is derived from the principle of vibration transmission, which can ensure that vibrations in each frequency band are effectively attenuated and resonance is avoided, thereby ensuring the vibration reduction effect of the entire frequency band.

[0129] 4. Coupling design of damper and spring. In terms of damper installation, by optimizing the contact area relationship between the damper mounting seat and the main leaf spring, that is, Ensures sufficient load-bearing capacity and prevents premature wear and failure. c is the contact area, A b is the cross-sectional area of ​​the spring, γ is the area ratio coefficient, F d is the damping force, F sis the spring force. This relationship is derived from the Hertz contact theory, which takes into account the nonlinear effect of the load on the contact area. The introduction of the coefficient γ can also compensate for the error during the installation process. At the same time, a rubber vibration isolation pad is set between the damper and the spring to effectively isolate the direct contact between the metals and avoid the problem of local stress concentration.

[0130] 5. Flexible fixed assembly design. The fixed assembly adopts a flexible connection method of rubber gasket and U-shaped clamp. Compared with the rigid connection, this design can not only effectively absorb displacement deformation, but also give full play to the damping characteristics of rubber, thereby further improving the overall vibration reduction performance. Among them, the relationship between the compression amount and pressure of the rubber gasket is δ=k1P+k2P 2 +k3ln(1+P), the coefficients k1, k2, k3 are obtained through experimental fitting. This relationship can accurately describe the nonlinear mechanical properties of rubber.

[0131] The above is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art can easily think of changes or substitutions within the technical scope disclosed by the present invention, which should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims

1. A leaf-less spring suspension system for a sightseeing vehicle, characterized in that: The main leaf spring assembly comprises a main leaf spring assembly, a secondary leaf spring assembly, a fixing assembly, an anti-loosening assembly and a damping vibration reduction assembly; a variable cross-section section is provided in the middle of the main leaf spring assembly, and the thickness of the variable cross-section section gradually decreases from the center to both ends; the length of the secondary leaf spring assembly is shorter than that of the main leaf spring assembly, and the secondary leaf spring assembly is fixedly connected to the main leaf spring assembly by a central bolt; the fixing assembly is arranged at both ends of the main leaf spring assembly, and the anti-loosening assembly is arranged inside the fixing assembly; the damping vibration reduction assembly comprises a high-frequency damper, a medium-frequency damper, and a The main leaf spring assembly comprises a damper and a low-frequency damper; the high-frequency damper is arranged in the middle of the main leaf spring assembly, the medium-frequency damper is arranged at the front end of the main leaf spring assembly, and the low-frequency damper is arranged at the rear end of the main leaf spring assembly; the damping coefficient of the high-frequency damper is 15,000 Newtons per meter per second, which is used to attenuate vibrations above 20 Hz; the damping coefficient of the medium-frequency damper is 10,000 Newtons per meter per second, which is used to attenuate vibrations from 5 to 20 Hz; the damping coefficient of the low-frequency damper is 5,000 Newtons per meter per second, which is used to attenuate vibrations below 5 Hz.

2. The leaf-less spring suspension system for a sightseeing vehicle according to claim 1, characterized in that: The main leaf spring assembly includes a main spring body, a main spring eye and a reinforcing pad. The main spring eye is arranged at both ends of the main spring body, and the reinforcing pad is fixed at the connection between the main spring body and the main spring eye. The variable cross-section section is located in the middle of the main spring body, and its length accounts for 30 to 40% of the total length of the main spring body.

3. The leaf-less spring suspension system for a sightseeing vehicle according to claim 2, characterized in that: The auxiliary leaf spring assembly includes an auxiliary spring body and a center positioning sleeve. The auxiliary spring body is an arc-shaped structure, and the center positioning sleeve is fixed to the middle of the auxiliary spring body. Both ends of the auxiliary spring body abut against the main leaf spring assembly to form a double-layer leaf spring structure.

4. The leaf-spring-less suspension system for a sightseeing vehicle according to claim 3, characterized in that: The fixing assembly includes a fixing seat, a rubber pad and a U-shaped clamp. The fixing seat is a square structure with a rubber pad on the inner side. The rubber pad is tightly pressed against the main leaf spring assembly. The U-shaped clamp is sleeved on the outer side of the main leaf spring assembly and fixedly connected to the fixing seat by a connecting bolt assembly.

5. The leaf-spring-less suspension system for a sightseeing vehicle according to claim 4, characterized in that: The high-frequency damper includes a high-frequency damping cylinder, a high-frequency damping piston and high-frequency damping oil. The high-frequency damping cylinder is provided with a high-frequency damping chamber, the high-frequency damping chamber is filled with the high-frequency damping oil, and the high-frequency damping piston penetrates the high-frequency damping chamber; the high-frequency damping piston is provided with a high-frequency damping hole, and the diameter of the high-frequency damping hole is 2 mm.

6. The leaf-less spring suspension system for a sightseeing vehicle according to claim 5, characterized in that: The intermediate frequency damper comprises an intermediate frequency damping cylinder, an intermediate frequency damping piston and an intermediate frequency damping oil. An intermediate frequency damping chamber is provided in the intermediate frequency damping cylinder. The intermediate frequency damping chamber is filled with the intermediate frequency damping oil. The intermediate frequency damping piston runs through the intermediate frequency damping chamber. An intermediate frequency damping hole is provided on the intermediate frequency damping piston, and the diameter of the intermediate frequency damping hole is 3 mm.

7. The leaf-spring-less suspension system for a sightseeing vehicle according to claim 6, characterized in that: The low-frequency damper comprises a low-frequency damping cylinder, a low-frequency damping piston and a low-frequency damping oil. A low-frequency damping chamber is provided in the low-frequency damping cylinder. The low-frequency damping chamber is filled with the low-frequency damping oil. The low-frequency damping piston runs through the low-frequency damping chamber. A low-frequency damping hole is provided on the low-frequency damping piston, and the diameter of the low-frequency damping hole is 4 mm.

8. The leaf-less spring suspension system for sightseeing vehicles according to claim 4, characterized in that: The connecting bolt assembly includes a first connecting bolt and a second connecting bolt. The first connecting bolt is arranged on both sides of the fixing seat and passes through the main leaf spring assembly; the second connecting bolt is arranged in the middle of the U-shaped clamping plate and is connected to the anti-loosening assembly.

9. The leaf-spring-less suspension system for a sightseeing vehicle according to claim 1, characterized in that: The anti-loosening assembly includes a sliding mechanism, a clamping mechanism and an operating mechanism; the sliding mechanism is arranged inside the U-shaped clamp, the clamping mechanism connects the sliding mechanism and the second connecting bolt, and the operating mechanism is fixed to the outer end of the clamping mechanism; the sliding mechanism includes a slide groove body and a slider assembly, the slide groove body is opened on the inner wall of the U-shaped clamp, and the slider assembly is slidably arranged in the slide groove body; the slider assembly includes two symmetrically arranged sliding blocks, and the sliding blocks are fixedly connected by a connecting ring.

10. The leaf-less spring suspension system for a sightseeing vehicle according to claim 1, characterized in that: The high-frequency damper, the medium-frequency damper and the low-frequency damper are all fixedly connected to the main leaf spring assembly via a damper mounting seat, and the damper mounting seat is connected to the main leaf spring assembly via high-strength bolts; a rubber vibration isolation pad is provided between the damper mounting seat and the main leaf spring assembly to prevent metal contact between the damper and the main leaf spring assembly.

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