Improved design method for a collector shoe

Abstract

The application discloses an improved design method suitable for a current collector shoe and belongs to the technical field of power supply of rail transit. The three-dimensional entity model, the dynamic simplified model, the finite element model and the shoe-rail coupling model of the current collector shoe are respectively established, so that conditions are provided for acquisition and optimization of key parameters of the current collector shoe, and bases are provided for determination of the optimization and improvement direction of the current collector shoe and proposal of the optimization and improvement scheme, thereby improving the shoe-rail dynamic contact problem of the current collector shoe. The improved design method suitable for the current collector shoe is simple in steps and convenient in design, and provides the possibility for simulation calculation of key parameters of the current collector shoe, optimization of the key parameters of the current collector shoe and determination of the optimization and improvement direction of the current collector shoe, thereby realizing improvement of the structure of the current collector shoe, improving the reliability of dynamic contact current collection of the current collector shoe under high-speed conditions, ensuring the stability of application of the current collector shoe, prolonging the service life of the current collector shoe, reducing the operation and maintenance cost of the current collector shoe, and having good practical value and application prospect.

Description

Technical Field

[0001] This invention belongs to the field of rail transit power supply technology, specifically relating to an improved design method for current collector shoes. Background Technology

[0002] In the operation of rail transit, the method of combining current supply shoes and contact rails for current supply is a widely used form of current supply, and it has mature applications in different types of rail transit.

[0003] Currently, urban rail transit contact rail current collection systems are mainly used in urban rail transit with speed levels of 120 km / h and below. However, with increasing demands for higher operating speeds, existing three-rail current collection systems are increasingly unable to meet the needs of fast-paced urban life. The dynamic current collection quality of the current collector shoe system, as one of the bottlenecks restricting the speed increase of urban rail vehicles, is mainly determined by the dynamic contact state between the current collector shoe and the contact rail. When the train speed is low, the contact problem between the contact rail and the current collector shoe is still within a controllable range. However, as the train speed increases, the impact force, number of collisions, and vibration amplitude between the two will significantly increase. This will lead to a series of serious problems such as current collector shoe detachment from the contact rail, accelerated wear of the current collector shoe, and arc damage to the current collector shoe, increasing train operation and maintenance costs and even endangering train safety. Therefore, adopting reasonable and effective methods to solve the dynamic contact problem of the contact rail / current collector shoe system under high-speed conditions is of great significance for overcoming the speed bottleneck of contact rail current collection trains.

[0004] Furthermore, the dynamic contact operation state between the contact rail and the current collector shoe is formed under the coupling effect based on the characteristics of the current collector shoe and the contact rail themselves. During the dynamic contact process under coupling effect, the local key parameters of the current collector shoe often have a significant role and influence on the coupled dynamic operation. Therefore, how to improve the dynamic contact problem between the current collector shoe and the contact rail by studying the local key parameters of the current collector shoe has become a key research direction in recent years. Summary of the Invention

[0005] In response to one or more of the above-mentioned defects or improvement needs of the existing technology, the present invention provides an improved design method for current collector shoes, which can realize the simulation modeling of the current collector shoe structure, and on this basis, determine the key parameters and optimization directions of the current collector shoe, thus providing the possibility for proposing improved design schemes for current collector shoes and improving the current supply stability of the current collector shoe in dynamic contact under high-speed train operation conditions.

[0006] To achieve the above objectives, the present invention provides an improved design method for current collector shoes, comprising the following steps:

[0007] S1: Obtain the relevant parameters of each component of the current collector shoe and draw a three-dimensional solid model of the current collector shoe;

[0008] S2: Based on the structural form of the current collector shoe, a simplified dynamic model of the current collector shoe is proposed, resulting in a mass-spring-damping model based on the physical current collector shoe and a three-dimensional solid model.

[0009] S3: Establish the finite element model of the current collector shoe based on the mass-spring-damping model of the current collector shoe;

[0010] S4: Establish a coupled simulation model of the collector shoe and the third rail;

[0011] S5: Determine the key parameters of the collector shoe through simulation calculation, test bench measurement, and calculation;

[0012] S6: Optimize the key parameters of the current collector shoe and determine the direction of optimization and improvement of the current collector shoe;

[0013] S7: Based on the obtained optimization and improvement direction of the current collector shoe, determine the improvement design scheme of the current collector shoe structure and complete the improvement of the current collector shoe structure.

[0014] As a further improvement of the present invention, in step S2, the mass-spring-damping model is a simplified dual-mass model, which includes a base plate, two mass blocks, a first spring and a first damper disposed between the first / second mass blocks, and a second spring and a second damper disposed between the second mass block and the base plate.

[0015] As a further improvement of the present invention, in step S3, the established finite element model of the current collector shoe retains the surface shape of the first mass block, that is, retains the geometric features of the current collector shoe slider.

[0016] As a further improvement of the present invention, in step S4, for the contact coupling of the shoe rail system, the penalty function method is adopted, and the Newmark-β method is used to calculate the integral of the contact force in the finite element dynamic analysis.

[0017] As a further improvement of the present invention, in step S5, the key parameters of the current collector shoe include natural frequency, equivalent mass, equivalent stiffness and equivalent damping ratio.

[0018] As a further improvement of the present invention, the key parameters of the current collector shoe are measured by combining the three-dimensional solid model of the current collector shoe and the dynamic test platform of the simplified dynamic model component.

[0019] As a further improvement of the present invention, the dynamic test platform includes a pantograph-catenary system vibration test machine, a DHDAS dynamic signal acquisition and analysis instrument, a height gauge, a digital displacement gauge, a vernier caliper, a piezoelectric impact hammer, a piezoelectric accelerometer, and weights.

[0020] As a further improvement of the present invention, in step S6, the optimization targets for the current collector shoe are the standard deviation of the shoe rail contact force, vibration acceleration, and offline time.

[0021] As a further improvement of the present invention, a multi-objective optimization algorithm based on non-dominated sorting genetic optimization algorithm is used to perform multi-objective optimization of the collector shoe.

[0022] As a further improvement of the present invention, the optimization direction of the current collector shoe is determined by the parameter value when the standard deviation of the contact force is optimal.

[0023] The aforementioned improved technical features can be combined with each other as long as they do not conflict with each other.

[0024] In summary, the beneficial effects of the above-described technical solutions conceived by this invention compared with the prior art include:

[0025] (1) The improved design method of the present invention for current collector shoes includes multiple steps. By establishing the three-dimensional solid model, the simplified dynamic model, the finite element model, and the shoe-rail coupling model of the current collector shoe, conditions are provided for obtaining and optimizing the key parameters of the current collector shoe, and a basis is provided for determining the direction of optimization and improvement of the current collector shoe and proposing optimization and improvement schemes. This improves the dynamic contact problem between the current collector shoe and the rail, significantly reduces the possibility of offline between the current collector shoe and the rail, improves the reliability and stability of the contact between the current collector shoe and the rail, and improves the current transmission quality between the current collector shoe and the rail, thus providing power supply guarantee for the accelerated operation of rail transit.

[0026] (2) The improved design method of the present invention for collector shoes, by further optimizing the implementation details in each step of the design, adopts a simplified model of dual-mass collector shoes and a multi-objective optimization algorithm of non-dominated sorting genetic optimization algorithm, quickly realizes the optimization of key parameters of collector shoes, provides convenience for determining the direction of collector shoe improvement and obtaining subsequent improvement schemes, and simplifies the improvement design process of collector shoes.

[0027] (3) The improved design method of the present invention for current collector shoes is simple in steps and easy to design. It establishes a three-dimensional solid model and a simplified dynamic model of the current collector shoe through the physical object, and establishes a finite element model of the current collector shoe and a coupling simulation model of the current collector shoe and the third rail on this basis. It provides conditions for the simulation calculation, test bench measurement and reduction of key parameters of the current collector shoe, and also provides the possibility for the optimization of key parameters of the current collector shoe and the determination of the direction of optimization and improvement of the current collector shoe. In the end, it realizes the improvement of the current collector shoe structure, improves the reliability of dynamic contact current supply of the current collector shoe under high speed conditions, ensures the safety and reliability of the current collector shoe application, extends the service life of the current collector shoe, and reduces the operation and maintenance cost of the current collector shoe. It has good practical value and application prospects. Attached Figure Description

[0028] Figure 1 This is a schematic diagram of the design process for the improved design method applicable to current collector shoes in this embodiment of the invention;

[0029] Figure 2 This is a schematic diagram of the physical structure of the type A current collector shoe in an embodiment of the present invention;

[0030] Figure 3 This is a schematic diagram of the physical structure of the type B current collector shoe in an embodiment of the present invention;

[0031] Figure 4 , Figure 5 This is a simplified dynamic model constructed for the collector shoe in this embodiment of the invention;

[0032] Where k, m, and c are the equivalent stiffness, equivalent mass, and equivalent damping of the connecting component, respectively; Fc is the static contact pressure of the third rail acting on the current collector shoe; F0 is the static lifting force generated by the current collector shoe tension spring; y, y1, and y2 are the vertical displacements of the mass blocks; each equivalent mass block is only given vertical degrees of freedom, and the current collector shoe can be considered to be in translational motion as a whole during the train's operation.

[0033] Figure 6 This is a schematic diagram of the finite element model of the current collector shoe in an embodiment of the present invention;

[0034] Figure 7 This is a schematic diagram of the coupling simulation model of the current collector shoe and the third rail in an embodiment of the present invention;

[0035] The third track is a longitudinally continuous rigid structure, and no vibration damping structure is installed between it and the connection point. It is considered as multiple tracks with mass m. eq The track elements are connected by multiple links with stiffness k. eq The spring is connected to the connecting part; at the same time, the connecting part of the shoe rail system can be considered as having a contact stiffness of k. cont The spring, when compressed and deformed, generates a contact force F between the two. cont This can further reduce the contact force F cont It is considered a "coupler" of the boot track system.

[0036] Figure 8 This is a schematic diagram of the functional relationship for determining the optimal solution based on the weights of the objective function in an embodiment of the present invention.

[0037] Figure 9 , Figure 10 This is a schematic diagram of the improved and optimized Type A current collector shoe and Type B current collector shoe in the embodiments of the present invention. Detailed Implementation

[0038] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention. Furthermore, the technical features involved in the various embodiments of this invention described below can be combined with each other as long as they do not conflict with each other.

[0039] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0040] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0041] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0042] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "over," and "on top" of the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0043] Example:

[0044] The preferred embodiment of the present invention provides an improved design method for current collector shoes, which aims to improve the structure of current collector shoes, enhance the dynamic current supply quality between current collector shoes and contact rails, solve the dynamic contact problem between contact rails and current collector shoes under high-speed train movement, and break through the speed-up bottleneck of trains using contact rail current supply.

[0045] Specifically, the improved design method for current collector shoes in the preferred embodiment follows the process as follows: Figure 1 The steps shown are as follows:

[0046] S1: Obtain the relevant parameters of each component of the current collector shoe and draw a three-dimensional solid model of the current collector shoe;

[0047] In actual operation, the parameter information of the components of the current collector shoe is obtained by disassembling and measuring the size of the physical current collector shoe. Based on this, a three-dimensional solid model of the current collector shoe is drawn, and then the mass and centroid position of each component are obtained.

[0048] Meanwhile, in the preferred embodiment, SolidWorks 3D drawing software is preferably used to draw the 3D solid model of the current collector shoe, and the model parameters of each component are calculated based on this model.

[0049] Furthermore, in the preferred embodiment, the studied current collector shoe is preferably of two types, namely... Figure 2 The type A current collector shoe shown and Figure 3 The image shows a Type B current collector shoe. In contrast, the Type A current collector shoe has a carbon fiber sliding plate, while the Type B current collector shoe's sliding plate is composed of a combination of metal sliders.

[0050] S2: Based on the structural form of the current collector shoe, a simplified dynamic model of the current collector shoe is proposed, resulting in a mass-spring-damping model based on the physical current collector shoe and a three-dimensional solid model.

[0051] In practical operation, based on the three-dimensional solid model of the current collector shoe and the mass and centroid position of each component, the simplified dynamic model of the current collector shoe is preferably constructed in two forms, namely, as follows: Figure 4 The single-mass-spring-damped model shown and as Figure 5 The model shown is a dual-mass, dual-spring, dual-damped model.

[0052] More specifically, the simplified model of a single-mass collector shoe ( Figure 4 The simplification process is based on actively ignoring the high-frequency vibration characteristics of the system. Therefore, it has good calculation results when studying the low-frequency vibration of the collector shoe, and the calculation results also have relatively good convergence.

[0053] In contrast, for the simplified model of a dual-mass current collector shoe ( Figure 5The system comprises a base plate, two mass blocks, a first spring and a first damper positioned between the two mass blocks, and a second spring and a second damper positioned between the second mass block and the base plate. For the simplified model of the dual-mass current collector shoe, the reduction strategy is based on the simplified model of the single-mass current collector shoe, considering the high-frequency vibration characteristics of the current collector shoe (including the elastic deformation of flexible components such as the current collector shoe swing arm and the slipper bracket), thereby adding a spring / damper / mass block to form a dual-mass system. In fact, the aforementioned simplified model of the single-mass current collector shoe is equivalent to a simplified dual-mass model where k1 is infinitely large.

[0054] In the preferred embodiment, the current-carrying scenario of the current collector shoe at higher vehicle speeds is studied. Therefore, the simplified dual-mass current collector shoe model is used in the design of the preferred embodiment, and the parameters of the current collector shoe are optimized based on it for higher vehicle speeds. In addition, at higher vehicle speeds (usually not less than 150 km / h), the excitation frequency also increases accordingly, so the simplified dual-mass current collector shoe model is more valuable for reference.

[0055] Of course, in actual design, if the current collector shoe is being improved for a train with a lower operating speed, a simplified model of a single-mass current collector shoe can be used, which will not be elaborated here.

[0056] S3: Establish the finite element model of the current collector shoe;

[0057] Based on the analysis of the simplified dynamic model of the current collector shoe in S2, a finite element model of the current collector shoe for shoe-rail coupling simulation is established. Considering that the contact sliding between the current collector shoe and the third rail (contact rail) differs from the point-to-point contact between the pantograph and the contact wire in high-speed rail, the simplified model of the dual-mass current collector shoe in S2 needs to retain the surface shape of the current collector shoe slider (first mass block m1) to contact the third rail with a unique contact surface, thereby restoring the functionality of the shoe-rail system. Therefore, the finite element model of the current collector shoe adopts a scheme that preserves the geometric features of the slider.

[0058] In a preferred embodiment, a three-dimensional solid model of the current collector shoe slider is established based on the ANSYS / Classic environment, and the entire model is meshed into a hexahedral mesh using SOLID185 solid elements. By setting parameters such as the slider's shape, material density, volume, and elastic modulus, the slider's mass, surface shape, and surface stiffness are made to meet the modeling requirements. Correspondingly, spring elements and lumped mass elements are used to establish other structures in the current collector shoe finite element model, ultimately forming a model as shown below. Figure 6 The finite element model of the collector shoe is shown.

[0059] S4: Establish a coupled simulation model of the collector shoe and the third rail;

[0060] Based on the simplified dynamic models of the current collector shoe and the contact rail, a coupled dynamic model of the current collector shoe and the third rail is constructed, as follows: Figure 7 As shown in the image.

[0061] Meanwhile, for the contact coupling of the shoe-rail system, the penalty function method is preferred, and the Newmark-β method is used to calculate the contact force integral in the finite element dynamic analysis.

[0062] S5: Determine the key parameters of the collector shoe through simulation calculation, test bench measurement, and calculation;

[0063] In a preferred embodiment, the key parameters of the current collector shoe include its natural frequency, equivalent mass, equivalent stiffness, and equivalent damping ratio. For the physical current collector shoe, these key parameters are preferably obtained by constructing a dynamic test platform combining a three-dimensional solid model and a simplified dynamic model of the current collector shoe.

[0064] More specifically, the preferred dynamic testing platform includes a pantograph-catenary system vibration testing machine, a DHDAS dynamic signal acquisition and analysis instrument, a height gauge, a digital displacement gauge, a vernier caliper, a computer, a piezoelectric impact hammer, a piezoelectric accelerometer, weights, and other equipment. On the dynamic testing platform of the current collector shoe, the spring stiffness of the model is measured, and modal tests are conducted on the actual current collector shoe product using an impact hammer or a pantograph-catenary system vibration testing machine to measure its natural frequency and damping ratio.

[0065] In studying the vibration characteristics of the current collector shoe, since the current collector shoe vibrates during its coupled motion with the third rail, including both low-frequency and high-frequency vibrations, after simplifying the current collector shoe into a mass-spring-damped system, its vibration period T (inversely proportional to the vibration frequency f) satisfies the vibration relationship of a single-degree-of-freedom system with respect to the mass m and stiffness k:

[0066]

[0067] Meanwhile, research on the equivalent stiffness of current collector shoes, regardless of whether they are type A or type B, shows that their stiffness is relatively soft, meaning their stiffness values ​​are relatively small. In this case, using a general material tensile testing machine for stiffness measurement may lead to inaccurate results due to the limited accuracy of the stiffness-displacement relationship curve measured by the tensile and compressive sensors of the tensile testing machine at small force values. Therefore, in a preferred embodiment, a combination of a digital displacement gauge with an accuracy of 0.01 mm and weights is preferred to measure the force and displacement relationship of the current collector shoe, and then the measurement data is numerically fitted to obtain its corresponding equivalent stiffness value.

[0068] Furthermore, in a preferred embodiment, the calculation of key parameters of a type B current collector shoe will be used as an example for explanation.

[0069] Based on the simplified dynamic model of the current collector shoe, the Type B current collector shoe comprises two mass block models: a sliding shoe assembly and a swing arm support assembly. In practical operation, it is preferable to construct test benches for each of the two mass block models. Weights are applied to both mass block models to exert a certain vertical force, and their vertical displacement is measured using a height gauge (with a measurement accuracy of 0.01 mm). Then, linear fitting is performed on the measurement data to obtain the slope of the fitted curve, which represents the equivalent stiffness value of the corresponding assembly. Correspondingly, based on the construction of the test benches, other key parameters of the current collector shoe can also be calculated.

[0070] In a specific preferred embodiment, the dynamic parameters obtained by actual measurement in the B-type current collector shoe test are as follows: the natural frequency of the slipper is f1 = 20.5 Hz, the equivalent mass is m1 = 2.87 kg, the equivalent stiffness is k1 = 47650 N / m, and the equivalent damping ratio is c1 = 1.4%; the natural frequency of the swing arm support is f2 = 1.7 Hz, the equivalent mass is m2 = 7.04 kg, the equivalent stiffness is k2 = 803 N / m, and the equivalent damping ratio is c2 = 3.3%.

[0071] S6: Optimize the key parameters of the current collector shoe and determine the direction of optimization and improvement of the current collector shoe;

[0072] In practical design, the optimization of the shoe-rail relationship mainly involves three indicators: standard deviation of shoe-rail contact force, vibration acceleration, and offline time. Therefore, in the preferred embodiment, a multi-objective optimization algorithm based on a non-dominated sorting genetic optimization algorithm is preferably used for the multi-objective optimization of the current collector shoe.

[0073] More specifically, in the multi-objective optimization, the six reduced parameters in the simplified model of the dual-mass current collector shoe are preferred as variables, and the multi-objectives are the standard deviation of the shoe-rail contact force, vibration acceleration, and offline time.

[0074] In practice, a multi-objective optimization algorithm is used to compare objective functions and update the population of optimization parameters. In one specific embodiment, the population size is set to 20, representing that each generation of search includes 20 sets of collector shoe parameter combinations. Under the non-dominated sorting genetic optimization algorithm, each objective function is searched for optimization. During the search, the next generation will form a new set of 20 collector shoe parameters based on the calculation results of the previous generation and continue the calculation. At the same time, through 30 iterations, a space of 600 sets of calculation results is formed. Based on this, the values ​​of each objective function when obtaining the optimal parameters in the multi-objective process are shown in the table below.

[0075]

[0076] Within a space comprised of three objectives, mutual constraints and optimization yielded the following results: the optimal contact force standard deviation is 32.5 N; the optimal offline time is 0.008 s; and the optimal vibration acceleration is 245.24 m / s². 2 .

[0077] Combining the multi-objective optimization results with the aforementioned table, it can be observed that the offline time is relatively small under all three objectives, and the vibration acceleration is at a moderate level when the contact force standard deviation is optimal. Therefore, it is recommended that the current collector shoe be optimized when the contact force standard deviation is optimal, i.e., m1, k1, c1, c2, and k2 should be optimized to increase, while m2 should be optimized to decrease.

[0078] Furthermore, in the aforementioned multi-objective optimization process, the multi-objective optimization is calculated using a method where each of the three optimization objectives has a weight of 1. Through optimization calculation, the optimal solution set of the three optimization objectives is obtained, and a fitted surface of the optimal solution set is obtained through fitting. This surface contains the multi-objective optimal solution set in the parameter calculation space (the 6 parameter variables of the simplified dual-mass current collector shoe model), and when actually determining the optimization scheme, it can be selected from the above three sets of schemes.

[0079] Of course, in actual design, reasonable optimization objective function weights can be selected according to the actual line conditions. For example, considering the weight ratios of contact force standard deviation / maximum vibration acceleration / offline time as 0.8 / 0.1 / 0.1 respectively, and on this basis, the normalized parameters of the simplified model of the normalized dual-mass current collector shoe adapted to the actual line conditions can be calculated, such as... Figure 8 As shown in the diagram. Alternatively, the optimal solution can be found directly in the search space using a weighted optimization objective function, based on the determined objective function weights.

[0080] S7: Based on the obtained optimization and improvement direction of the current collector shoe, determine the improvement design scheme of the current collector shoe structure and complete the improvement of the current collector shoe structure.

[0081] In step S6, the optimization direction of the current collector shoe in the preferred embodiment is determined to be that m1, k1, c1, c2, and k2 are optimized in the direction of increasing, and m2 is optimized in the direction of decreasing. Based on this, the corresponding improvement scheme is designed:

[0082] Firstly, regarding the increase in mass m1, since the existing current collector shoe's sliding plate material is typically a metal alloy, the operational space for increasing the mass m1 by increasing the material density is limited. However, without affecting the vehicle clearance, increasing the volume of the metal sliding plate can also increase the sliding plate's mass, thereby achieving the optimization goal of increasing m1. Simultaneously, based on operational experience, the sliding plate material experiences significant wear during electrified friction between the metal sliding plate and stainless steel. Therefore, a carbon-plated metal sliding plate is preferable, but the plate support should be made of copper alloy. Designing a larger sliding plate support can further improve the mass m1. In practical design, by redesigning the metal sliding plate structure, an initial increase of 20% in m1 is relatively easy to achieve.

[0083] Secondly, for optimizing the stiffness k1 in the direction of increase, it is preferable to directly increase the diameter d of the helical spring wire. In a specific embodiment, the initial diameter of the helical spring wire is 2mm. The main material of this spring is steel wire, and the optimization space for increasing stiffness by changing the material is relatively limited. Meanwhile, the magnitude of the current collector shoe stiffness value k1 mainly depends on the stiffness of the helical spring; the greater the stiffness of the helical spring, the larger the value of k1. Without changing the space of the current collector shoe slide plate, the wire diameter of the spring wire can be increased from 2mm to 3mm, or even to the limit of 4mm, thereby increasing k1 and optimizing the current collector shoe. Furthermore, in actual selection, using the increase of the spring wire diameter to improve the spring stiffness k1 also requires comprehensive consideration of factors such as national standards, spring installation space, and whether the manufacturing process meets the requirements. After comprehensively considering all factors, the limit of k1 increase in the preferred embodiment is approximately 800%. In a comparative example (the comparison item in the aforementioned table), the original parameters of the k1 compression spring were: effective number of coils n = 5, mean diameter D = 25mm, and wire diameter d = 2mm, with a calculated original spring stiffness of 47650 N / m. After optimization, the optimized parameters were n = 5, D = 25mm, and d = 3.5mm, resulting in an optimized spring stiffness of 446905 N / m, representing a significant improvement compared to the comparison item.

[0084] In contrast, the stiffness k2 depends on the torsional stiffness of the torsion spring; the greater the stiffness of the torsion spring, the larger k2. Therefore, optimizing k2 in the increasing direction can be achieved by increasing the torsional stiffness of the torsion spring. The formula for the stiffness of a torsion spring is:

[0085] k=(Ed 4 ) / (3670D·n)

[0086] In the formula: E is the elastic modulus of the material, d is the diameter of the torsion spring wire, D is the outer diameter of the torsion spring, and n is the number of turns of the torsion spring.

[0087] Combining the above formulas, it is easy to see that the torsional stiffness can be increased by increasing the wire diameter of the torsion spring, decreasing the mean diameter of the torsion spring, or decreasing the effective number of coils of the torsion spring. Alternatively, all three parameters can be changed simultaneously to increase the torsional stiffness of the torsion spring. In the preferred embodiment, considering all the above factors, the maximum increase in k2 is approximately 400%. In a comparative example (the comparison item in the aforementioned table), the original parameters of the k2 compression spring are effective number of coils n = 7, mean diameter D = 55mm, and wire diameter d = 7mm, with a calculated original spring stiffness of 803 N / m. After optimization, the optimized parameters are n = 7, D = 55mm, and d = 10.5mm, resulting in an optimized spring stiffness of 4065 N / m, a significant improvement compared to the comparison item.

[0088] Furthermore, regarding the optimization of mass m2 towards reduction, in the preferred embodiment, this can be achieved by replacing some or all of the steel connecting flanges and bolts with aluminum alloy. In a comparative example (corresponding to the comparison items in the aforementioned table), the total mass of the components included in the second mass block structure of the current collector shoe is 8565.89g. The base material of the two insulating plates is insulating bakelite, which has a low density and a simple structure. Weight reduction has already been achieved through grooving and rounding. Further grooving and rounding would affect the structural strength; therefore, the reduction in mass m2 through structural optimization and replacement with bakelite is extremely limited. However, in the preferred embodiment, by replacing all the steel connecting flanges with aluminum alloy, the overall mass is reduced from 8565.89g (equivalent to 7.04kg) to 7239.91g, significantly reducing m2. Furthermore, if all the steel connecting flanges, bolts, and pins are replaced with aluminum alloy, the mass of the second mass block structure can be further reduced to 6364.65g (equivalent to 6.07kg), which is the limit that can be achieved by reducing m2.

[0089] Furthermore, optimization of c1 and c2 is needed. For existing current collector shoes, damping mainly consists of frictional damping and material-specific damping. Frictional damping values ​​are unstable and easily affected by environmental conditions. In the comparative example, the current collector shoe damping values ​​are c1 = 10.3 Ns / m and c2 = 4.96 Ns / m. According to the optimization results in the table, the optimized damping values ​​are larger than the initial values, i.e., the optimized c1 = 205.91 Ns / m and c2 = 15.4 Ns / m. In actual installation, to improve the damping value of the current collector shoe, a tie-rod spring structure or a hydraulic damper is preferred, and the placement of these structures within the current collector shoe should be optimized to achieve the desired result. Figure 9 (Type A collector shoe) Figure 10 The current collector shoe mechanism shown in (Type B current collector shoe).

[0090] The improved design method for current collector shoes in this invention is simple in steps and easy to design. It establishes a three-dimensional solid model and a simplified dynamic model of the current collector shoe through physical objects, and on this basis, establishes a finite element model of the current collector shoe and a coupling simulation model of the current collector shoe and the third rail. This provides conditions for the simulation calculation, test bench measurement, and reduction of key parameters of the current collector shoe, and also provides the possibility for optimizing key parameters of the current collector shoe and determining the direction of optimization and improvement of the current collector shoe. Ultimately, it realizes the improvement of the current collector shoe structure, improves the reliability of dynamic contact current supply under high-speed conditions, ensures the safety and reliability of the current collector shoe application, extends the service life of the current collector shoe, and reduces the operation and maintenance costs of the current collector shoe. It has good practical value and application prospects.

[0091] Those skilled in the art will readily understand that the above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. An improved design method for current collector shoes, characterized in that, Includes the following steps: S1: Obtain the relevant parameters of each component of the current collector shoe and draw a three-dimensional solid model of the current collector shoe; S2: Based on the structural form of the current collector shoe, a simplified dynamic model of the current collector shoe is proposed, resulting in a mass-spring-damping model based on the physical current collector shoe and a three-dimensional solid model. The mass-spring-damping model is a simplified dual-mass model, which includes a base plate, two mass blocks, a first spring and a first damper set between the first and second mass blocks, and a second spring and a second damper set between the second mass block and the base plate. S3: Establish the finite element model of the current collector shoe based on the mass-spring-damping model of the current collector shoe; S4: Establish a coupled simulation model of the collector shoe and the third rail; S5: Determine the key parameters of the current collector shoe through simulation calculation, test bench measurement, and reduction; the key parameters of the current collector shoe include natural frequency, equivalent mass, equivalent stiffness, and equivalent damping ratio; S6: Optimize the key parameters of the current collector shoe and determine the direction of optimization and improvement of the current collector shoe; The optimization objectives for the current collector shoe are the standard deviation of the shoe rail contact force, vibration acceleration, and offline time; and a multi-objective optimization algorithm based on non-dominated sorting genetic optimization algorithm is used to optimize the current collector shoe. S7: Based on the obtained optimization and improvement direction of the current collector shoe, determine the improvement design scheme of the current collector shoe structure and complete the improvement of the current collector shoe structure.

2. The improved design method for current collector shoes according to claim 1, characterized in that, In step S3, the established finite element model of the current collector shoe retains the surface shape of the first mass block, that is, it retains the geometric features of the current collector shoe slider.

3. The improved design method for current collector shoes according to claim 1, characterized in that, In step S4, the penalty function method is used to address the contact coupling of the shoe-rail system. In the finite element dynamic analysis, Newmark- β The method is used to perform integral calculations of contact forces.

4. The improved design method for current collector shoes according to any one of claims 1 to 3, characterized in that, For the physical current collector shoe, its key parameters are measured by combining the three-dimensional solid model of the current collector shoe with the dynamic test platform of the simplified dynamic model component.

5. The improved design method for current collector shoes according to claim 4, characterized in that, The dynamic test platform includes a pantograph-catenary system vibration test machine, a DHDAS dynamic signal acquisition and analysis instrument, a height gauge, a digital displacement gauge, a vernier caliper, a piezoelectric impact hammer, a piezoelectric accelerometer, and weights.

6. The improved design method for current collector shoes according to any one of claims 1 to 3 and 5, characterized in that, The optimization direction of the current collector shoe is determined by the parameter values ​​when the standard deviation of the contact force is optimal.

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