Improved new energy electric vehicle shock absorber

Abstract

The utility model discloses an improved shock absorber of a new energy electric vehicle. The shock absorber is a double-cylinder type hydraulic shock absorber. The shock absorber comprises a shock absorber outer cylinder and a shock absorber sliding column which is embedded in the shock absorber outer cylinder and slides relative to the shock absorber outer cylinder. The upper supporting seat is detachably connected to one side, far away from the shock absorber outer cylinder, of the shock absorber sliding column; the lower supporting seat is fixedly connected to one side, close to the shock absorber sliding column, of the shock absorber outer cylinder; one end of the spiral spring is connected to the upper supporting seat, and the other end of the spiral spring is connected to the lower supporting seat; the spiral spring is a variable-wire-diameter spiral spring with a thick middle part and two thin ends. According to the utility model, the driving smoothness and the riding comfort of the new energy automobile are optimized.

Description

Technical Field

[0001] The utility model relates to the technical field of shock absorbers, in particular to an improved shock absorber for new energy electric vehicles. Background Art

[0002] As new energy vehicles are increasingly favored by governments and related industries of various countries, the suspension shock absorption system is an important part of new energy vehicles. Moreover, this system also provides good steering stability for new energy vehicles and buffers vibrations and impacts caused by uneven road surfaces. Further, the vibrations and impacts that traditionally affect vehicles mainly come from external vibrations caused by the contact between the vehicle and the ground and internal vibrations caused by the transmission of the engine. Since new energy electric vehicles replace the traditional engine with an electric motor drive, the influence of internal vibrations is greatly reduced. Therefore, the influence of external vibrations caused by the contact between the vehicle and the ground on the driver is more intuitive and obvious. Therefore, in order for new energy vehicles to have higher operability and stability, the need to iteratively optimize the shock absorption performance of the suspension system is relatively urgent. Summary of the Utility Model

[0003] In view of this, the purpose of the present utility model is to provide an improved shock absorber for new energy electric vehicles, which optimizes the driving smoothness and riding comfort of new energy vehicles.

[0004] According to one aspect of the present utility model, there is provided an improved shock absorber for new energy electric vehicles, which is a double-cylinder hydraulic shock absorber; wherein, the shock absorber includes a shock absorber outer cylinder and a shock absorber sliding column embedded in the shock absorber outer cylinder and sliding relative thereto; and,

[0005] an upper support seat, which is detachably connected to the side of the shock absorber sliding column away from the shock absorber outer cylinder;

[0006] a lower support seat, which is fixedly connected to the side of the shock absorber outer cylinder close to the shock absorber sliding column;

[0007] a helical spring, one end of which is connected to the upper support seat and the other end is connected to the lower support seat; the helical spring is a variable wire diameter helical spring with a thicker middle and thinner ends.

[0008] In the above technical solution, a double-cylinder hydraulic shock absorber is selected in this case. The double-cylinder hydraulic shock absorber not only has stable working performance, but also has the advantages of low frictional resistance and low noise. Therefore, this type of shock absorber is selected in this case. Among them, the elastic element adopts a helical spring. The elastic element is the main element in the automotive suspension system to reduce and suppress the body vibration. Its function is to bear and transmit the vertical load from the body and the road surface, relieve and reduce the body vibration caused by the road surface impact, and improve the ride comfort of the vehicle. Leaf springs, helical springs, torsion bar springs, and air springs are several main common types of elastic elements in automotive suspensions. Although leaf springs were the first to be used in automotive suspensions, due to many design deficiencies of leaf springs themselves, such as excessive weight, etc., they have been gradually phased out in vehicle manufacturing. For torsion bar springs, they have also been gradually replaced because of the excessive lateral space required for the chassis. For helical springs, because the longitudinal space they occupy is relatively small, and the mass of the helical spring itself is also relatively light, helical springs have gradually become the most common elastic elements in automotive suspensions. Therefore, a helical spring is selected as the elastic element of the suspension system in this case. Further, based on the research on existing helical springs, it is found that the inner side and the 2.5-turn position of the helical spring are often the most likely places where the helical spring fails due to fatigue. Moreover, since the size and shape of the wire cross-section of traditional constant-stiffness helical springs are generally unchanged, the stress conditions are different at different cross-sections, resulting in different stress magnitudes, which leads to the spring being prone to breakage at the places where the force is larger. Therefore, this case adopts a variable wire diameter helical spring to maximize the performance of all materials as much as possible, thereby reducing material waste and making the stress distribution of the spring more uniform. Therefore, further optimizing the helical spring into a variable wire diameter helical spring improves the reliability and durability of the entire suspension system, and greatly reduces the possibility of the helical spring failing and breaking.

[0009] In some embodiments, both ends of the variable wire diameter helical spring are tightened and ground for one turn each, the effective number of turns of the spring n = 6, the number of support turns is 2, and the mean diameter D = 85 mm; the wire diameters of the first and second effective turns at both ends of the helical spring are 8 mm, and the wire diameter in the middle part is 12 mm.

[0010] In the above technical solution, the inner side and the 2.5-turn position of the helical spring are often the most likely places where the helical spring fails due to fatigue. Moreover, since the size and shape of the wire cross-section of traditional constant-stiffness helical springs are generally unchanged, the stress conditions are different at different cross-sections, resulting in different stress magnitudes, which leads to the spring being prone to breakage at the places where the force is larger. Therefore, this case adopts a variable wire diameter helical spring to maximize the performance of all materials as much as possible, thereby reducing material waste and making the stress distribution of the spring more uniform.

[0011] In this case, the following optimizations were mainly carried out on the helical spring:

[0012] (1) In the design, the diameter of the screw on the inner side of the helical spring was appropriately thickened to withstand stronger loads and impacts, enabling the entire suspension damping system to better exert its damping and buffering performance.

[0013] Therefore, in this case, the outer diameter of the helical spring was reduced to 8 mm, and the inner diameter was increased to 12 mm.

[0014] (2) Since the lower side of the spring mostly plays a supporting and restraining role, in this design, the diameter of the screw on the lower side was appropriately reduced to better save costs.

[0015] In some embodiments, an upper connecting plate is provided on the side of the upper support seat away from the helical spring. The upper connecting plate is positioned and sleeved on the shock absorber strut through a bearing; one end of the shock absorber strut away from the shock absorber outer cylinder locks the upper connecting plate through a nut.

[0016] In the above technical solution, the function of the upper support of the helical spring is to connect the helical spring and the upper connecting plate of the helical spring, enabling the helical spring to have a better and more stable connection with the vehicle body and the frame.

[0017] In some embodiments, the material of the helical spring is 60Si2Mn, the spring stiffness Ks = 15.686 N / m, and the helix direction is right-handed.

[0018] In the above technical solution, the suspension spring will experience high-frequency compression and tension during the operation of the vehicle and plays a very important role in the suspension. Therefore, the quality of the helical spring has an important impact on the driving quality of the vehicle and the smoothness and safety of driving. Therefore, the helical spring in the automotive suspension must be analyzed with high precision to achieve and optimize the complex buffering and damping effects of the spring. Therefore, the above settings were made in this case. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the following drawings are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0020] Figure 1 is a schematic structural diagram of an embodiment of an improved shock absorber for a new energy electric vehicle of the present invention;

[0021] Figure 2 is an embodiment of an improved shock absorber for a new energy electric vehicle of the present invention Figure 1-Schematic diagram at location A;

[0022] Figure 3 It is a schematic diagram of the helical spring modeling of an embodiment of an improved shock absorber for a new energy electric vehicle of the present utility model;

[0023] Figure 4 It is the deformed cloud diagram of the helical spring of an embodiment of an improved shock absorber for a new energy electric vehicle of the present utility model;

[0024] Figure 5 It is the shear stress cloud diagram of the helical spring of an embodiment of an improved shock absorber for a new energy electric vehicle of the present utility model;

[0025] Figure 6 It is the first six-order vibration mode diagram of the helical spring of an embodiment of an improved shock absorber for a new energy electric vehicle of the present utility model;

[0026] Figure 7 It is a schematic diagram of the variable wire diameter helical spring modeling of an embodiment of an improved shock absorber for a new energy electric vehicle of the present utility model;

[0027] Figure 8 It is the deformed cloud diagram of the variable wire diameter helical spring of an embodiment of an improved shock absorber for a new energy electric vehicle of the present utility model;

[0028] Figure 9 It is the stress analysis diagram of the variable wire diameter helical spring of an embodiment of an improved shock absorber for a new energy electric vehicle of the present utility model;

[0029] Figure 10 It is the response x(t) image of the variable wire diameter helical spring of an embodiment of an improved shock absorber for a new energy electric vehicle of the present utility model. Detailed implementation manners

[0030] The present utility model will be further described in detail below in conjunction with the drawings and embodiments. It should be specifically pointed out that the following embodiments are only used to illustrate the present utility model, but do not limit the scope of the present utility model. Similarly, the following embodiments are only partial embodiments of the present utility model rather than all embodiments. All other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present utility model.

[0031] The present utility model provides an improved shock absorber for a new energy electric vehicle, which optimizes the driving smoothness and riding comfort of new energy vehicles.

[0032] Embodiment 1

[0033] Please refer to Figure 1, in the figure, there are upper support bearing 1, upper support seat 2, dust cover 3, helical spring 4, shock absorber outer cylinder 5, shock absorber piston rod 6, lower support seat 7, high-strength M20 large hexagon nut 8, washer 9, bearing positioning sleeve 10, and upper connecting plate 11. This shock absorber is a double-cylinder hydraulic shock absorber; among them, this shock absorber includes a shock absorber outer cylinder 5 and a shock absorber piston rod 6 embedded in the shock absorber outer cylinder 5 and sliding relative to it; and, an upper support seat 2, which is detachably connected to the side of the shock absorber piston rod away from the shock absorber outer cylinder; a lower support seat 7, which is fixedly connected to the side of the shock absorber outer cylinder 5 close to the shock absorber piston rod 6; a helical spring 4, one end of which is connected to the upper support seat 2 and the other end is connected to the lower support seat 7; the helical spring 4 is a variable wire diameter helical spring with a thick middle and thin ends. On the side of the upper support seat 2 away from the helical spring 4, there is an upper connecting plate 11, and the upper connecting plate 11 is sleeved on the shock absorber piston rod 6 through a bearing positioning sleeve; the end of the shock absorber piston rod 6 away from the shock absorber outer cylinder 5 locks the upper connecting plate 11 through a nut 8. Specifically, please refer to Figure 2 , the upper connecting plate 11 is sleeved on the shock absorber piston rod 6, and an upper support bearing 1 and a bearing positioning sleeve 10 are arranged in the gap between the shock absorber piston rod 6 and the upper connecting plate 11; after a washer 9 is placed on the end of the shock absorber piston rod 6 away from the shock absorber outer cylinder 5, it is tightened with a high-strength M20 large hexagon nut 8. The function of the helical spring upper support is to connect the helical spring and the helical spring upper connecting plate, so that the helical spring has a better and more stable connection with the vehicle body and the frame.

[0034] In this embodiment, a double-cylinder hydraulic shock absorber is selected for this case. The double-cylinder hydraulic shock absorber not only has stable working performance, but also has the advantages of low frictional resistance and low noise. Therefore, this type of shock absorber is selected in this case. Among them, the elastic element adopts a helical spring. The elastic element is the main element in the automotive suspension system to reduce and suppress the body vibration. Its function is to bear and transmit the vertical loads from the body and the road surface, relieve and reduce the body vibration caused by the road surface impact, and improve the ride comfort of the vehicle. Leaf springs, helical springs, torsion bar springs, and air springs are several main common types of elastic elements in automotive suspensions. Although leaf springs were the first to be used in automotive suspensions, due to many design deficiencies of leaf springs themselves, such as excessive weight, etc., they have been gradually phased out in vehicle manufacturing. For torsion bar springs, they have also been gradually replaced due to the excessive lateral space required in the chassis. For helical springs, because the longitudinal space they occupy is relatively small and the mass of the helical spring itself is also relatively light, helical springs have gradually become the most common elastic elements in automotive suspensions. Therefore, a helical spring is selected as the elastic element of the suspension system in this case. Further, based on the research on existing helical springs, it is found that: the inner side and the 2.5 turns of the helical spring are often the most likely places where the helical spring fails due to fatigue. Moreover, since the size and shape of the cross-section of the wire of traditional constant-stiffness helical springs are generally unchanged, the stress conditions are different at different cross-sections, resulting in different stress magnitudes, which causes the spring to be prone to fracture at the places where the force is relatively large. Therefore, a variable wire diameter helical spring is adopted in this case to maximize the performance of all materials, thereby reducing material waste and making the stress distribution of the spring more uniform. Therefore, further optimizing the helical spring into a variable wire diameter helical spring improves the reliability and durability of the entire suspension system, and greatly reduces the possibility of the helical spring failing and breaking.

[0035] In this embodiment, one turn is tightened and ground flat at each end of the variable wire diameter helical spring. The effective number of turns of the spring n = 6, the number of support turns is 2, and the mean diameter D = 85 mm; the wire diameter of the first and second effective turns at both ends of the helical spring is 8 mm, and the wire diameter in the middle is 12 mm. The specific calculation of the helical spring parameters is as follows:

[0036] Original data:

[0037]

[0038] (1) Partial frequency

[0039] For ordinary household cars, the partial frequency of the front suspension is generally between 1.00 - 1.45 Hz.

[0040] Therefore, in this case, f0 = 1.4 Hz is taken

[0041] (2) Suspension stiffness K

[0042]

[0043] And the mass m1 on the single-wheel spring is 145 kg

[0044] So K = 4π 2 f0 2 m1 = 11220 N / m

[0045] (3) Spring stiffness Ks

[0046] Take the lever ratio i = 0.9 and the installation angle α = 200

[0047]

[0048] (4) Spring working load

[0049] The maximum working load F1 = m1gcosα = 1335 N

[0050] The minimum working load F2 = m2gcosα = 1151 N

[0051] (5) The maximum shear stress under the maximum working load

[0052]

[0053] In the formula, C is the spring winding ratio, C = D / d, and the general value range is 4 - 9. In this case, take c = 8, D is the mean diameter of the helical spring, and d is the cross-sectional diameter of the helical spring; k is the spring curvature coefficient, generally taken as 1. Initially select 60Si2Mn as the material of the helical spring. Looking up the table, [τ] = 710 and the shear modulus G = 78500 N / mm2. Substitute the data into the formula to get d ≥ 6.2 mm

[0054] According to the spring size parameter selection standard in the following table, in the text, take d = 10 mm and D = 85 mm; τmax = 318.87 < [τ], which meets the standard

[0055]

[0056] (6) Calculate the number of spring coils

[0057]

[0058] After rounding, the effective number of spring coils n = 6. One coil is tightened and ground at each end of the spring, and the number of support coils is 2

[0059] Then the total number of coils is n = 6 + 2 = 8

[0060] (7) Spring verification

[0061] When the free height of the spring exceeds 4 times the mean diameter of the spring, and when the axial deformation of the spring is large, the spring will produce lateral bending and lose stability. Therefore, when designing a helical spring, it is necessary to calculate and check the stability of the spring.

[0062] Height-diameter ratio:

[0063]

[0064] Therefore, the stability meets the requirements.

[0065] (8) Other dimensions of the spring

[0066]

[0067] In this embodiment, the helical spring elastic element is the most important component of the suspension, which alleviates and reduces the vehicle body vibration caused by road unevenness and improves the ride comfort of the vehicle.

[0068] The following are the parameter selection of the helical spring structure design and the material selection:

[0069] (1) Select 60Si2Mn as the material of the helical spring

[0070] (2) One coil is tightened and ground at each end of the spring. The effective number of turns of the spring n = 6, and the number of support turns is 2.

[0071] (3) The cross-sectional diameter of the spring material d = 8mm, and the mean diameter D = 85mm.

[0072] (4) Helix direction: right-handed;

[0073] The lower support of the helical spring can not only support the spring and limit it, but also be connected to the lower control arm of the frame, so as to obtain a better shock absorption effect. The following are the parameter selection of the helical spring lower support structure design and the material selection:

[0074] (1) Select 08F steel as the material.

[0075] (2) The parts need to be normalized after machining.

[0076] (2) The parts should be deburred and chamfered.

[0077] The function of the upper support of the helical spring is to connect the helical spring and the upper connecting plate of the helical spring, so that the helical spring has a better and more stable connection with the vehicle body and the frame. The following are the parameter selection of the helical spring upper support structure design and the material selection:

[0078] (1) Select 08F steel as the material.

[0079] (2) The parts need to be normalized after machining.

[0080] (2) The parts should be deburred and chamfered.

[0081] The upper connecting plate of the helical spring functions to connect the upper support of the helical spring and the vehicle body, enabling a better and more stable connection between the helical spring, the vehicle body, and the frame. The following are the parameters of the design of the upper connection structure of the helical spring and the selection of materials:

[0082] (1) The material selected is 08F steel.

[0083] (2) After machining, the parts need to be normalized.

[0084] (2) The parts should be deburred and chamfered.

[0085] Furthermore, the suspension spring will experience high-frequency compression and tension during vehicle operation and plays a very important role in the suspension. Therefore, the quality of the helical spring has an important impact on vehicle ride quality, driving safety, and smoothness. Therefore, the helical spring in the automotive suspension must undergo high-precision analysis to achieve and optimize the complex buffering and shock-absorbing effects of the spring. The finite element method can detail the simulation of the influence of stress on the stress and strain of the helical spring and can accurately reflect the relationship between the helical spring material and strength, fatigue failure, and permanent deformation. In this paper, the Ansysworkbench finite element analysis software is used to analyze the axial deformation and force of the helical spring in the automotive suspension. For the three-dimensional model of the helical spring in the automotive suspension, please refer to Figure 3 ,.

[0086] The meshing of the helical spring in the automotive suspension, that is, finite element meshing. Since the quality of the mesh division plays a very important role in the reliability of the analysis results, the main aspects considered during mesh division are: the type of mesh and the size of the mesh. When performing mesh division, first use the mesh in the model module of Ansysworkbench to automatically mesh the model, then check the mesh quality, adjust the overall mesh size, and finally determine to use tetrahedral element meshing. The overall mesh size of the helical spring is adjusted to a tetrahedral mesh with a size of 2 mm. The detailed mesh data table is shown in the following table:

[0087]

[0088]

[0089] To accurately simulate the actual working state of the helical spring in the vehicle suspension system, the boundary conditions and axial shear stress of the finite element model of the helical spring need to be established during the analysis process. A fixed constraint is applied to the lower edge of the spring seat to ensure that there is no radial displacement of the upper and lower edges of the helical spring relative to the lower support of the spring. An axial force is applied to the upper end of the spring to simulate the influence of the helical spring on the automotive suspension under normal load. Through finite element analysis, it can be seen that, please refer to Figure 4, when a load is added to the helical spring, the deformation of the helical spring gradually increases to 43.674 mm, and the stiffness of the helical spring increases significantly. When the pressure inside the helical spring continues to increase, the two ends of the helical spring contact the lower support plate and the upper connecting plate respectively. When the stress increases to a certain extent, the two ends of the helical spring will also contact, which means the deformation of the helix reaches a maximum of 131.18 mm.

[0090] Please refer to Figure 5 The shear stress nephogram of the helical spring. The following conclusions can be drawn from the above shear stress nephogram results:

[0091] (1) The shear stress inside the spring is significantly greater than the shear stress outside the spring

[0092] (2) When the applied axial pressure increases from 0 to 1500 N, the maximum shear stress appears near the inner side of the upper 1 - 1.5 turns of the helical spring, and the stress it bears is 375.96 MPa. After the pressure continues to increase to 2000 N, the position where the maximum shear stress of the helical spring appears shifts to the inner side near the starting 1.5 - 2 turns at the bottom of the helical spring, and the stress it bears is 751.91 MPa. When the pressure on the helical spring continues to increase to the maximum load of the helical spring, which is 3000 N, the position where the helical spring is subjected to the maximum shear stress continues to move down to the position near the starting 1.5 - 2.5 turns at the top. The maximum stress at this point is 1127.9 MPa. All these places where the maximum stress appears may be the positions where the helical spring breaks under overload pressure and the places where fatigue failure occurs.

[0093] Furthermore, a modal analysis is carried out on the helical spring. As a key component of the shock absorption system of new energy vehicles, when the vehicle is driving, the vibrations generated by the vehicle due to the impact of uneven road surfaces and the vibrations generated by the vehicle itself will ultimately be transmitted to the driver through the suspension helical spring. When the suspension excitation frequency approaches the natural frequency of the vehicle itself and the natural frequency of the driver's body, resonance will occur, thus affecting the ride comfort and driving smoothness. Modal analysis can perform a dynamic analysis on the finite element model and can determine the natural frequency, vibration mode and other characteristics of the structure through modal analysis. Therefore, the seat can be detected whether it meets the design requirements through modal analysis. On the basis of the previous static analysis, the original fixed constraints and load forces are retained, and a modal analysis is carried out on the helical spring to obtain the first 6 - order frequencies and vibration modes of the modal analysis, as Figure 6 shown. The descriptions of each order of frequency, deformation and vibration mode are shown in the following table:

[0094]

[0095] It can be analyzed from the figures and tables that the vibration modes of the helical spring are mainly dominated by swinging and torsion. There are not significant changes in the 1st and 2nd order vibration modes. In the 3rd order vibration mode, the helical spring undergoes torsion, and the vibration frequency at this time is 75.52 Hz. In the 6th order vibration mode, the helical spring undergoes a large torsional deformation with a deformation amount of 71.038 mm, but the vibration frequency is as high as 182.18 Hz, which is almost impossible to occur in real life. During the vehicle driving process, the excitation received by the suspension damping system mainly comes from the following two aspects: one is the vibration from the engine. However, the engine has good smoothness, resulting in a small vibration amplitude and a low frequency; the other is the bump caused by the uneven road surface. The excitation frequency generated by the vehicle on a relatively good road surface is generally between 1 - 3 Hz, and the excitation frequency of the whole vehicle is generally around 10 Hz. It can be seen from Table 5 - 3 that the first - order vibration frequency of the helical spring is 59.206, which is significantly higher than the excitation frequency of the whole vehicle, and the possibility of resonance is relatively low. The designed helical spring can meet the actual use requirements of the vehicle.

[0096] It can be found from the above Ansys analysis that the inner side of the helical spring and the position at 2.5 turns are often the most likely places where the helical spring undergoes fatigue failure. Moreover, since the size and shape of the cross - section of the traditional constant - stiffness helical spring wire are generally unchanged, the stress conditions are different at different cross - sections, resulting in different stress magnitudes, which causes the spring to be prone to fracture at the places where the force is larger. Therefore, in this paper, a variable - wire - diameter helical spring is adopted to maximize the performance of all materials as much as possible, thereby reducing material waste and making the stress distribution of the spring more uniform.

[0097] The following optimizations are mainly carried out on the helical spring in this paper:

[0098] (1) The diameter of the screw on the inner side of the helical spring is appropriately thickened in the design to withstand stronger loads and impacts, enabling the entire suspension damping system to better exert its shock - absorption and buffering performance.

[0099] Therefore, in this paper, the outer diameter of the helical spring is reduced to 8 mm, and the inner diameter is increased to 12 mm.

[0100] (2) Since the lower side of the spring mostly plays a supporting and restraining role in most cases, in this design, the diameter of the screw on the lower side is appropriately reduced to better save costs.

[0101] Furthermore, for the finite - element analysis of the optimized helical spring, please refer to the model Figure 7 and for the results, please refer to Figure 8 and Figure 9As can be seen from the figure, the maximum stress on the inner side of the optimized helical spring near 1.5 turns is 864.89 MPa, which is lower than the shear stress generated by the previously designed helical spring under the ultimate load. Moreover, for the optimized helical spring, the deformation is 87.434 mm, which is significantly better than that of the non-optimized helical spring before. The reliability and durability of the entire suspension system have been improved, and the possibility of failure and fracture of the helical spring has been greatly reduced.

[0102] Furthermore, for the calculation of the vibration of the optimized helical spring, the formula for the equivalent stiffness K of the spring is:

[0103]

[0104] In the formula: G is the shear modulus of the spring; dk is the wire diameter of the middle main section of the helical spring; d0 is the screw diameter on both sides of the helical spring; D is the mean diameter of the spring; η is the deformation coefficient of the helical spring, and η is selected as 21.8 according to the mean diameter and free height of the spring; k is the number of deformed turns of the spring. The response x(t) image is as Figure 10 shown:

[0105] Calculation of the amplitude ratio:

[0106] Assume the vehicle is traveling at 72 km / h, so the basic road surface remains the same as above and ω = 20.944

[0107] Vehicle natural frequency

[0108]

[0109] Therefore, the frequency ratio is

[0110]

[0111] Calculating the amplitude ratio gives

[0112]

[0113] It can be seen from this that for the improved helical spring, the calculated equivalent stiffness becomes smaller, and thus the calculated amplitude ratio is 0.177, which is significantly smaller than the amplitude ratio of 0.227 calculated for the previously designed helical spring. Moreover, from the above x(t) response diagram, under the preset condition that the road surface undulation is 50 mm, the vehicle body undulation is 15 mm, which is also significantly smaller than the vehicle body amplitude of 20 mm caused by the 50 mm road surface undulation calculated previously. Therefore, it can be analyzed that the optimized helical spring reduces the vehicle body vibration caused by a 50 mm road surface undulation by 5 mm, achieving the preset optimization effect.

[0114] The above are only some embodiments of the present utility model, and thus do not limit the protection scope of the present utility model. Any equivalent device or equivalent process transformation made by using the content of the specification and drawings of the present utility model, or directly or indirectly applied in other related technical fields, shall similarly be included in the patent protection scope of the present utility model.

Claims

1. An improved shock absorber for new energy electric vehicles, characterized in that: The shock absorber is a double-cylinder hydraulic shock absorber; wherein the shock absorber comprises a shock absorber outer cylinder and a shock absorber sliding column embedded in the shock absorber outer cylinder and sliding relatively thereto; and, An upper support seat, the upper support seat is detachably connected to a side of the shock absorber sliding column away from the shock absorber outer cylinder; A lower support seat, the lower support seat is fixedly connected to a side of the shock absorber outer cylinder close to the shock absorber sliding column; A coil spring, one end of which is connected to an upper support seat, and the other end of which is connected to a lower support seat; the coil spring is a variable wire diameter coil spring with a thick middle and thin ends.

2. An improved new energy electric vehicle shock absorber as claimed in claim 1, characterized in that: The two ends of the variable wire diameter coil spring are tightened by one circle and ground flat, the effective number of coils of the spring is n=6, the number of supporting coils is 2, and the middle diameter D=85mm; the wire diameters of the first and second effective coils at both ends of the coil spring are 8mm, and the wire diameter in the middle is 12mm.

3. An improved new energy electric vehicle shock absorber as claimed in claim 1, characterized in that: An upper connecting plate is arranged on the side of the upper support seat away from the coil spring, and the upper connecting plate is sleeved on the shock absorber slide column through a bearing positioning sleeve; the upper connecting plate is locked by a nut on the end of the shock absorber slide column away from the shock absorber outer cylinder.

4. An improved new energy electric vehicle shock absorber as claimed in claim 1, characterized in that: The material of the coil spring is 60Si2Mn, the spring stiffness Ks=15.686N / m, and the rotation direction is right-handed.

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