Waterproof steel spring vibration isolator inner sleeve with high damping ratio and design method

Abstract

The invention discloses a waterproof steel spring vibration isolator inner sleeve with a high damping ratio and a design method, and particularly relates to the technical field of vibration isolators, the inner sleeve comprises an inner top plate, a bottom plate, a spring and a damping agent, and is characterized in that an inner sleeve heightening rod is arranged in a vertical space on the inner side of the spring in a middle shaft area of the inner sleeve; the upper end of the inner cylinder heightening rod is welded to the inner top plate, and the lower end of the inner cylinder heightening rod is inserted into a lower blocking pipe of the bottom plate filled with the damping agent, so that a built-in piston-oil cylinder type viscous damping cavity is formed.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of vibration isolators, in particular to a waterproof high-damping-ratio steel spring vibration isolator inner sleeve and design method. BACKGROUND

[0002] Common types of track vibration isolators include rubber vibration isolators, steel spring vibration isolators, viscoelastic vibration isolators, and composite vibration isolators. Among them, the steel spring vibration isolator can effectively reduce the propagation of vibration by virtue of its good elastic performance and low natural frequency. The steel spring vibration isolator mainly includes an outer cylinder, an inner cylinder, a leveling plate, a locking plate, a locking bolt, and a flat washer, etc., and is used to isolate the floating slab from the track foundation (track bed base). By adjusting the natural frequency of the system, vibration energy is absorbed to achieve the effect of reducing vibration. It is a basic vibration isolation component of the floating slab ballastless track. It is currently widely used in subways and intercity railways, with an annual market demand of about 180-220 thousand sets. However, the requirements for vibration isolators vary in different regions and different projects, and there is a lack of unified design method, which affects the consistency and interchangeability of the product. The inner sleeve of the vibration isolator is composed of springs and damping materials, etc., and is the core component of the steel spring vibration isolator. It is required to be easy to observe, maintain and replace. The inner top plate and bottom plate of the traditional structure are fixedly connected by springs, spring adhesives, sheaths and clamps. During maintenance, there is a risk of separation between the top and bottom. Therefore, there is an urgent need for a vibration isolator and inner sleeve to overcome the problems existing in the prior art. SUMMARY

[0003] To this end, the present application provides a waterproof high-damping-ratio steel spring vibration isolator inner sleeve and design method to solve the problems raised in the background art.

[0004] In order to achieve the above-mentioned purpose, the present application provides the following technical scheme: a waterproof high-damping-ratio steel spring vibration isolator inner sleeve, the inner sleeve comprises an inner top plate, a bottom plate, a spring and a damping agent, and an inner cylinder heightening rod is arranged in the vertical space on the inner side of the spring in the central region of the inner sleeve, the upper end of the inner cylinder heightening rod is welded with the inner top plate, and the lower end is inserted into the lower blocking pipe of the bottom plate filled with the damping agent, forming an inner built-in piston-cylinder type viscous damping cavity.

[0005] Preferably, the inner sleeve further comprises a water hose sheath and a clamp, the inner side of the water hose sheath is designed with a convex ring, the outer wall of the upper pipe of the inner top plate and the outer wall of the lower pipe of the bottom plate are in close contact with the convex ring, and the outer side of the water hose sheath is designed with clamp mounting grooves up and down for mounting and locking the clamp.

[0006] Preferably, the inner top plate is horizontally placed at the uppermost position, the upper pipe and the upper blocking pipe are vertically connected below the inner top plate and extend downward from the inner top plate, wherein the upper pipe is located on the outer side and the upper blocking pipe is located in the central region on the inner side.

[0007] Preferably, the bottom plate is horizontally placed at the lowest position; the lower tube and the lower blocking tube are vertically connected above the bottom plate and extend upward from the bottom plate, wherein the lower tube is located at the outer side and the lower blocking tube is located at the inner side central region.

[0008] Preferably, the inner cylinder heightening rod comprises a steel bar.

[0009] Preferably, the steel bar is hollow.

[0010] Preferably, the outer surface of the steel bar is processed with fine threads.

[0011] Preferably, the inner cylinder heightening rod further comprises a round plate arranged at the lower end of the steel bar, and the steel bar is vertically arranged with the upper end connected to the inner top plate, and the steel bar can be a round steel.

[0012] Preferably, the round plate is horizontally arranged at the bottom of the steel bar.

[0013] Preferably, the number of the round plates is a positive integer greater than or equal to 1, and a plurality of round plates are arranged at the outer end of the steel bar in an up-down manner, and the damping agent is above the plurality of round plates.

[0014] Preferably, the round plate is provided with a through hole.

[0015] Preferably, the bottom end of the round plate is further vertically provided with a plurality of steel bar branches.

[0016] The application further discloses a design method of a waterproof high-damping-ratio inner sleeve of a steel spring vibration isolator, and numerical simulation is performed on the steel spring vibration isolator made of the inner sleeve, and the method is as follows.

[0017] 1) Calculate the frequency and the required damping coefficient of the vibration isolator.

[0018] Frequency: ;

[0019] Damping coefficient: ;

[0020] In the formula, k is the design stiffness, is the design required damping ratio, and m is the mass.

[0021] 2) According to the damping liquid height-damping coefficient fitting function c=a1h-b1, calculate the damping liquid height h, wherein a1 and b1 are the coefficients of the fitting function.

[0022] 3) According to the additional stiffness fitting curve k c =c1h d1 , calculate the additional stiffness k c of the damping liquid, wherein c1 and d1 are the coefficients of the stiffness fitting curve.

[0023] 4) Calculate the design stiffness k of the steel spring, assuming the stiffnesses of the steel spring and the damping fluid are parallel. s :

[0024] k ;

[0025] 5) Initially determine the spring wire diameter d and mean diameter D, and calculate the minimum value of the spring wire diameter. :

[0026] ;

[0027] In the formula, ; F is the maximum working load on the spring. Here, e1 is the allowable torsional shear stress of the spring material, C is the correction factor, and C is the spring heave ratio.

[0028] 6) Based on the spring design stiffness k s Calculate the effective number of spring coils n:

[0029]

[0030] In the formula, G is the shear modulus of the spring material;

[0031] 7) Strength test of the spring Calculate and compare whether the requirements are met:

[0032]

[0033] Final stiffness of the spring Calculate and compare whether the requirements are met:

[0034]

[0035] in, This represents the effective number of spring coils after rounding.

[0036] 8) Verify the stiffness of the steel spring through numerical simulation:

[0037] The solid model of the steel spring is imported into simulation software to simulate the force-displacement curve of the spring model, and the simulated stiffness results and design stiffness k are obtained. s Compare the results and calculate whether the error rate meets the requirements.

[0038] 9) Verify the damping capacity of the vibration isolator:

[0039] The free acceleration decay curve of the vibration isolator was derived from the solid model of the steel spring, and six points after the first peak were selected for calculation to obtain the damping ratio of the vibration isolator, which is then compared with the design requirement damping ratio. Compare the results and calculate whether the error rate meets the requirements.

[0040] 10) Verify the stiffness of the isolator:

[0041] According to the force-displacement curve of the isolator, the stiffness of the isolator is obtained, and the error rate is calculated whether it meets the requirements by comparing with the design required stiffness k.

[0042] The new inner sleeve structure designed in the application aims to improve the damping ratio and stability of the steel spring isolator in working state, improve the vibration damping effect, and reduce the vibration decay time of the steel spring isolator, and the new water hose sheath structure aims to increase the waterproof function. BRIEF DESCRIPTION OF DRAWINGS

[0043] Figure 1 The design flowchart of the steel spring isolator with high damping ratio and waterproofness provided by the application is provided;

[0044] Figure 2 The spring model force-displacement curve provided by the application is provided;

[0045] Figure 3 The free decay curve of the isolator provided by the application is provided;

[0046] Figure 4 The force-displacement curve of the isolator provided by the application is provided;

[0047] Figure 5 The inner sleeve structure schematic diagram provided by the application is provided;

[0048] Figure 6 The inner top plate structure schematic diagram provided by the application is provided Figure 5 The middle water hose sheath assembly enlarged view provided by the application is provided;

[0049] Figure 7 The bottom plate structure schematic diagram provided by the application is provided;

[0050] Figure 8 The inner top plate structure schematic diagram provided by the application is provided;

[0051] Figure 9 The inner cylinder heightening rod multiple combination structure schematic diagram provided by the application is provided. DETAILED DESCRIPTION

[0052] The embodiments of the application are described below by specific specific embodiments, and those skilled in the art can easily understand other advantages and effects of the application from the content disclosed in the specification. Obviously, the described embodiments are part of the embodiments of the application, not all. Based on the embodiments in the application, all other embodiments obtained by those skilled in the art without creative labor belong to the scope of protection of the application.

[0053] Traditional structures connect the inner top / bottom plate using springs and spring rubber, supplemented by filling the inside of the lower tube and the outside of the lower baffle tube with damping agents (various liquids and solids, as well as other types such as polyurethane, silicone oil, nitrile rubber, etc.) to provide stiffness and damping ratio for vibration reduction. The inner top and bottom plates are locked together using sleeves and clamps. This invention proposes a design approach combining theoretical design, numerical simulation, and experimental verification. Based on the mechanical performance indicators of the vibration isolator, a design method for the parameters of each component of the vibration isolator is established.

[0054] This invention, based on a traditional structure, utilizes the vertical space inside the spring to add an inner cylinder extension rod. By leveraging the shearing action between the extension rod and the damper, a larger damping ratio is achieved, resulting in better vibration reduction. Furthermore, the addition of a more robust upper and lower connection method enhances the anti-loosening function of the entire inner sleeve structure, facilitating observation, inspection, and replacement. This inner sleeve structure ensures product quality and performance while reducing production cycle time and improving production line efficiency and on-site assembly efficiency.

[0055] Example 1: As Figure 5 As shown, this embodiment proposes a waterproof steel spring vibration isolator inner sleeve. The inner sleeve includes an inner top plate, a bottom plate, a spring, and a damping agent. An inner sleeve raising rod is provided in the vertical space inside the spring in the central axis region of the inner sleeve. The upper end of the inner sleeve raising rod is welded to the inner top plate, and the lower end is inserted into the lower baffle tube of the bottom plate filled with damping agent, forming a built-in piston-cylinder type viscous damping cavity.

[0056] In one exemplary instance, such as Figure 8 As shown, the inner top plate is placed horizontally at the top, and the upper tube and the upper baffle are vertically connected below the inner top plate and extend downward from the inner top plate. The upper tube is located on the outside, and the upper baffle is located in the inner center area.

[0057] In one exemplary instance, such as Figure 7 As shown, the base plate is placed horizontally at the bottom; the lower tube and the lower baffle tube are vertically connected above the base plate and extend upward from the base plate, wherein the lower tube is located on the outside and the lower baffle tube is located in the inner central area.

[0058] The following examples 2-9 refer to Figure 9 , Figure 9 The given inner cylinder heightening rod structure includes, but is not limited to, Figure 9 Similar structures listed in the text:

[0059] Example 2: Based on Example 1, the inner cylinder heightening rod in this example includes steel bars.

[0060] Example 3: Based on Example 2, except that the reinforcing bar can be a round steel bar.

[0061] Example 4: Based on Example 3, except that the reinforcing bar can be a round steel bar with coarse (fine) threads.

[0062] Example 5: Based on Example 1, the steel bars in this example are hollow.

[0063] Example 6: Based on Example 1, the inner cylinder heightening rod in this example also includes a circular plate set at the lower end of the reinforcing bar. The reinforcing bar is set vertically, and its upper end is connected to the inner top plate.

[0064] Example 7: Based on Example 6, in this example, the circular plate is horizontally set at the bottom of the reinforcing bar.

[0065] Example 8: Based on Example 6, the number of circular plates in this example is a positive integer greater than or equal to 1. Multiple circular plates are set at the outer ends of the reinforcing bars, and the damping agent covers multiple circular plates.

[0066] Example 9: Based on Example 6, the circular plate described in this example has through holes.

[0067] Example 10: Based on Example 6, in this example, the bottom end of the circular plate is also vertically provided with multiple steel bar branches, and the damping agent covers the multiple steel bar branches.

[0068] Example 11: As Figures 5-6 As shown, this embodiment is based on any of the above embodiments. The new hose sleeve structure aims to increase the waterproof function. The inner sleeve also includes a hose sleeve and a clamp. The inner side of the hose sleeve is designed with a convex ring. The outer wall of the upper pipe of the inner top plate and the outer wall of the lower pipe of the bottom plate are both in close contact with the convex ring. The outer side of the hose sleeve is designed with clamp mounting grooves on the upper and lower sides for clamp installation and locking. Under the dual action of the new hose sleeve structure and the clamp, the waterproof function of the inner sleeve can be effectively realized.

[0069] The novel inner sleeve structure of this embodiment consists of an inner top plate, an inner sleeve raising rod, a bottom plate, a spring, a spring adhesive, a liquid damper, a water hose sheath, and stainless steel clamps.

[0070] 1. After cutting the inner top plate, upper pipe, and upper baffle pipe, weld them coaxially in the center to form the inner cylinder top cover (without an inner cylinder extension rod).

[0071] 2. After the steel bars and round plates are cut to size, they are welded coaxially with the inner top plate to form the inner cylinder top cover.

[0072] 3. After cutting the base plate, lower tube, and lower baffle tube, weld them coaxially in the center to form the base plate.

[0073] 4. After the damping agent is filled, insert the spring and the inner top plate with the inner cylinder heightening rod.

[0074] 5. Use water hoses to wrap the outer sides of the inner top plate and bottom plate, and then use stainless steel clamps to lock and fix them.

[0075] After the base plate structure is welded, damping agent is poured into both the lower pipe and the lower retaining pipe. Then, a spring is placed in the lower pipe, and the inner top plate with the inner cylinder heightening rod is coaxially inserted into the lower retaining pipe. Finally, a water hose sleeve is fitted on the outside and locked with clamps. After the damping agent has completely cured, the inner sleeve forms a single unit.

[0076] like Figures 1-4 As shown, this invention also discloses a design method for an inner sleeve of a waterproof steel spring vibration isolator with a high damping ratio. Numerical simulation is performed on the steel spring vibration isolator made from the aforementioned inner sleeve, using the following method:

[0077] 1) Calculate the frequency of the vibration isolator and the required damping coefficient;

[0078] frequency: ;

[0079] Damping coefficient: ;

[0080] In the formula, k is the design stiffness. To meet design requirements for damping ratio;

[0081] 2) Calculate the damping fluid height h based on the damping fluid height-damping coefficient fitting function c=a1h-b1, where a1 and b1 are the coefficients of the fitting function;

[0082] 3) Based on the fitted curve k of the additional stiffness c =c1h d1 Calculate the additional stiffness k of the damping fluid. c In the formula, c1 and d1 are the coefficients of the stiffness fitting curve;

[0083] 4) Calculate the design stiffness k of the steel spring, assuming the stiffnesses of the steel spring and the damping fluid are parallel. s :

[0084] k ;

[0085] 5) Initially determine the spring wire diameter d, mean diameter D, and spring height. Calculate the minimum diameter of the spring wire. :

[0086] ;

[0087] In the formula, ; F is the maximum working load on the spring. Here, e1 is the allowable torsional shear stress of the spring material, C is the correction factor, and C is the spring heave ratio.

[0088] 6) Based on the spring design stiffness k s Calculate the effective number of spring coils n:

[0089]

[0090] In the formula, G is the shear modulus of the spring material;

[0091] 7) Strength test of the spring Calculate and compare whether the requirements are met:

[0092]

[0093] Final stiffness of the spring Calculate and compare whether the requirements are met:

[0094]

[0095] 8) Verify the stiffness of the steel spring through numerical simulation:

[0096] Import the solid model of the steel spring into simulation software to simulate the force-displacement curve of the spring model (see...). Figure 2 The simulated stiffness results and the design stiffness k are obtained. s Compare the results and calculate whether the error rate meets the requirements.

[0097] 9) Verify the damping capacity of the vibration isolator:

[0098] Derive the free acceleration decay curve of the vibration isolator from the solid model of the steel spring (see...) Figure 3 The damping ratio of the vibration isolator was calculated by selecting six points after the first peak value and comparing them with the design requirement damping ratio. Compare the results and calculate whether the error rate meets the requirements.

[0099] 10) Verify the stiffness of the vibration isolator:

[0100] According to the force-displacement curve of the vibration isolator (see...) Figure 4 The stiffness of the vibration isolator is obtained and compared with the design stiffness requirement to calculate whether the error rate meets the requirements.

[0101] The novel inner sleeve structure of this invention adds a damping agent inside the lower baffle tube and connects it to the inner top cover through a heightening rod, forming a piston-cylinder type viscous damping cavity inside the lower baffle tube. This greatly increases the damping coefficient to 7%-8%, which is twice that of the traditional structure (without the heightening rod, the damping coefficient is about 4%). It also greatly reduces the vibration decay time and improves its vibration reduction effect.

[0102] Compared to traditional structures, the manufacturing process of this novel inner sleeve structure only adds the blanking and welding of the inner sleeve heightening rod and the filling of damping agent in the lower baffle tube. Other components and the entire process remain unchanged, therefore the original production line does not need to be modified, resulting in lower investment costs and higher returns on the new product.

[0103] The design process provided by this invention can promote the research, application and popularization of vibration isolators in track vibration control, and provide a more efficient and economical solution for improving the mechanical performance of steel spring vibration isolators.

[0104] Although the present invention has been described in detail above with general descriptions and specific embodiments, modifications or improvements can be made to it, which will be obvious to those skilled in the art. Therefore, all such modifications or improvements made without departing from the spirit of the present invention fall within the scope of protection claimed by the present invention.

Claims

1. A waterproof inner sleeve of a high damping ratio steel spring isolator, the inner sleeve comprising an inner top plate, a bottom plate, a spring, and a damping agent, characterized in that: The spring inner side vertical space of the inner sleeve axial area is provided with an inner sleeve heightening rod, the upper end of the inner sleeve heightening rod is welded with the inner top plate, the lower end is inserted into the lower blocking pipe of the bottom plate filled with damping agent, forming an inner piston-cylinder viscous damping cavity.

2. A waterproof high damping ratio steel spring isolator inner sleeve according to claim 1, characterized in that: The inner sleeve further comprises a water hose sheath and a clamp, the inner side of the water hose sheath is designed with a convex ring, the outer wall of the upper pipe of the inner top plate and the outer wall of the lower pipe of the bottom plate are in close contact with the convex ring, the outer side of the water hose sheath is designed with a clamp mounting groove upward and downward, for the installation and locking of the clamp.

3. A waterproof high damping ratio steel spring isolator inner sleeve according to claim 1, characterized in that: The inner top plate is horizontally placed at the uppermost position, the upper pipe and the upper blocking pipe are vertically connected below the inner top plate and extend downward from the inner top plate, wherein the upper pipe is located at the outer side and the upper blocking pipe is located at the inner side central area.

4. A waterproof high damping ratio steel spring isolator inner sleeve according to claim 1, characterized in that: The bottom plate is horizontally placed at the lowermost position; the lower pipe and the lower blocking pipe are vertically connected above the bottom plate and extend upward from the bottom plate, wherein the lower pipe is located at the outer side and the lower blocking pipe is located at the inner side central area.

5. A waterproof high damping ratio steel spring isolator inner sleeve according to claim 1, wherein: The inner sleeve heightening rod comprises a steel bar.

6. A waterproof high damping ratio steel spring isolator inner sleeve according to claim 5, characterized in that: The inner sleeve heightening rod further comprises a round plate arranged at the lower end of the steel bar, the steel bar is vertically arranged, and the upper end thereof is connected with the inner top plate.

7. A waterproof high damping ratio steel spring isolator inner sleeve according to claim 6, characterized in that: The number of the round plates is a positive integer greater than or equal to 1, and a plurality of round plates are arranged upward and downward at the outer end of the steel bar, and the damping agent is above the plurality of round plates.

8. A waterproof high damping ratio steel spring isolator inner sleeve according to claim 6, characterized in that: A through hole is formed in the round plate.

9. A waterproof high damping ratio steel spring isolator inner sleeve according to claim 6, wherein: The bottom end of the round plate is further vertically provided with a plurality of steel bar branches, and the damping agent is above the plurality of steel bar branches.

10. A method of designing a waterproof inner sleeve of a steel spring isolator with high damping ratio, characterized in that: The steel spring isolator made of the inner sleeve according to any one of claims 1-9 is subjected to numerical simulation, and the method is as follows: 1) Calculate the frequency of the isolator and the required damping coefficient; Frequency: ; Damping coefficient: ; where k is the design stiffness, is the design demand damping ratio, and m is the mass. 2) According to the damping liquid height-damping coefficient fitting function c=a1h-b1, calculate the damping liquid height h, wherein a1 and b1 are the coefficients of the fitting function; 3) according to the additional stiffness fitting curve k c = c1h d1 , the additional stiffness k c of the damping liquid is calculated, wherein c1 and d1 are coefficients of the stiffness fitting curve; 4) According to the stiffness of the steel spring and the damping liquid is parallel stiffness, the steel spring design stiffness k is calculated s : k ； 5) initial spring wire diameter d, intermediate diameter D, calculation of the minimum spring wire diameter : ； In the formula, ; , F is the maximum working load of the spring, is the allowable torsional shear stress of the spring material, e1 is a correction factor, and C is the spring winding ratio. 6) According to spring design stiffness k s , calculate spring effective number of turns n: where G is the shear modulus of the spring material; 7) Strength of spring Accounting, contrast to meet the requirements: Final stiffness of spring Accounting, comparison, whether meet requirements: wherein, is the effective number of turns of the spring after rounding. 8) Verify the steel spring stiffness by numerical simulation: The steel spring entity model is introduced into the simulation software to simulate the force-displacement curve of the spring model, to obtain the simulation stiffness result, and the design stiffness k s Comparison is made to calculate whether the error rate meets the requirements; 9) Verify the damping capacity of the isolator: The acceleration free decay curve of the isolator is derived from the steel spring entity model, and the damping ratio of the isolator is obtained by calculating 6 points after the first peak value, which meets the design requirement The error rate is calculated and compared to determine whether it meets the requirements. 10) Verify the stiffness of the isolator: According to the force-displacement curve of the isolator, the stiffness of the isolator is obtained, which is compared with the design requirement stiffness k, and whether the error rate meets the requirements is calculated.

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