Pantograph head pneumatic lifting force optimization method

Abstract

The invention discloses a method for optimizing pneumatic lifting force of a pantograph head. An airflow adjusting convex plate used for improving a flow field structure so as to form a pressure difference between the upper side and the lower side of a carbon slide plate to improve the mean value of the pneumatic lifting force of the pantograph head is additionally arranged at the carbon slide plate of the pantograph head. The airflow adjusting convex plate is arranged at the carbon sliding plate of the pantograph head, the flow field structure is improved, the pneumatic lifting force mean value of the pantograph head is increased, the pantograph net following performance can be improved, the requirement of a higher-speed train for pantograph net contact force can be met, the current collection quality of the pantograph is improved, and due to the fact that the total lifting force target value of the pantograph head is fixed at the same speed, the current collection quality of the pantograph head is improved. And furthermore, the workload of the pantograph airbag can be reduced, the service life is prolonged, the fault occurrence frequency is reduced, and safe and stable operation of a train is ensured.

Description

Technical Field

[0001] The present invention relates to the field of rail transit technology, and in particular to a method for optimizing the pneumatic lifting force of a pantograph head. Background Art

[0002] As an important link between cities, high-speed rail has become the main mode of travel for passengers. In order to meet people's demand for high-speed travel, my country has launched a research and development plan for higher-speed trains with a designed speed of 400 kilometers per hour.

[0003] The pantograph is located on the top of the train and obtains current through the contact network to provide power for the train. The target value of the pantograph-catenary contact force is positively correlated with the train operating speed. The requirements for the pantograph-catenary contact force for higher-speed trains are also higher. If the pantograph lifting force is too low, the pantograph power supply will be unstable, arcing will occur, and in severe cases, even power outage accidents will occur.

[0004] The bow head lifting force is composed of pneumatic lifting force and airbag force. The pneumatic lifting force of the bow head directly affects the contact quality between the bow and the catenary. At higher operating speeds, if the pneumatic performance of the bow head is not optimized, the airbag will bear a greater workload, which will not only shorten its service life, but also increase the frequency of failures. Therefore, it is crucial for the stability and safety of train operation that the bow head has good pneumatic performance. Summary of the invention

[0005] The technical problem to be solved by the present invention is to provide a method for optimizing the pneumatic lifting force of the pantograph head, which can improve the average value of the pneumatic lifting force of the pantograph head, thereby meeting the requirements of the pantograph-catwalk contact force of higher speed trains.

[0006] In order to solve the above technical problems, the technical solutions adopted by the present invention are as follows.

[0007] A method for optimizing the aerodynamic lifting force of a pantograph bow head is provided, wherein an airflow regulating convex plate is added to a carbon slide plate of the pantograph bow head to improve the flow field structure so as to form a pressure difference between the upper and lower sides of the carbon slide plate to increase the average value of the aerodynamic lifting force of the bow head.

[0008] Preferably, the airflow regulating convex plate is arranged at the bottom of the carbon skateboard. The airflow regulating convex plate reduces the vortex intensity on the lower side of the carbon skateboard, converts large-scale vortices into small-scale vortices, improves the pressure environment on the lower side of the carbon skateboard, reduces the negative pressure intensity on the lower side of the carbon skateboard, and thereby increases the average aerodynamic lift force of the bow head.

[0009] Preferably, the airflow regulating convex plate comprises a convex plate body which is arranged along the length direction of the carbon slide plate and protrudes downward from the bottom of the carbon slide plate.

[0010] Preferably, the upper part of the convex plate body is embedded in the main structure of the carbon skateboard; the airflow regulating convex plate also includes a telescopic cylinder arranged in the main structure of the carbon skateboard and connected to the convex plate body, which is used to drive the convex plate body to move according to the actual train speed to change the height of the convex plate body protruding downward from the carbon skateboard.

[0011] Preferably, the airflow regulating convex plate is an embedded retractable structure, and also includes a telescopic cylinder arranged in the main structure of the carbon slide board and connected to the convex plate body, which is used to drive the convex plate body to move according to the actual train speed so as to protrude the convex plate body downward from the bottom of the carbon slide board and change the height of the convex plate body protruding downward from the carbon slide board.

[0012] Preferably, the number of airflow regulating convex plates is adjusted according to the design conditions of the train, including but not limited to the running speed and the running environment.

[0013] Preferably, a plurality of the airflow regulating convex plates are provided, and the plurality of airflow regulating convex plates are arranged symmetrically or asymmetrically along the center line of the carbon slide plate to achieve different lift-increasing effects of the pantograph in different running directions.

[0014] Due to the adoption of the above technical scheme, the technical progress achieved by the present invention is as follows.

[0015] The present invention improves the flow field structure and increases the average value of the aerodynamic lifting force of the pantograph by arranging an airflow regulating convex plate at the bottom of the carbon slide plate of the pantograph bow head, which not only helps to improve the pantograph-net followability, but also can meet the requirements of higher-speed trains for the pantograph-net contact force and improve the current collecting quality of the pantograph. In addition, because the target value of the total lifting force of the pantograph is fixed at the same speed, the workload of the pantograph airbag can be reduced, its service life can be extended, the frequency of failures can be reduced, and the safe and smooth operation of the train can be ensured. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a schematic diagram of the structure of an existing pantograph; Figure 2 for Figure 1 AA view of the existing pantograph equipped with the airflow adjustment convex plate of the present invention; Figure 3 It is the flow field optimization mechanism diagram of the present invention; Figure 4 The aerodynamic lift force time history curves of the original carbon slide and the carbon slide equipped with the airflow adjustment convex plate (the height of the convex plate body protruding downward from the carbon slide is adjusted to 3 mm) in Example 1 of the present invention; Figure 5 The aerodynamic lift force time history curves of the original carbon slide and the carbon slide with the airflow adjustment convex plate (the height of the convex plate body protruding downward from the carbon slide is adjusted to 8 mm) of the second embodiment of the present invention; Figure 6The aerodynamic lift results of the pantograph head obtained by closed-mouth operation of the pantographs with original carbon slide plates and carbon slide plates with airflow adjustment convex plates (the height of the convex plate body protruding downward from the carbon slide plate is adjusted to 3 mm) at different train speeds in an aviation wind tunnel according to the third embodiment of the present invention; Figure 7 The results of comparison of the standard values ​​of the lifting force and contact force of the carbon slide bow head of the pantograph installed with the original carbon slide and the additional airflow adjustment convex plate (the height of the convex plate body protruding downward from the carbon slide is adjusted to 3 mm) at different train speeds in Example 4 of the present invention.

[0017] Among them: 1. Carbon slide plate, 2. Airflow adjustment convex plate, 21. Convex plate body. DETAILED DESCRIPTION

[0018] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0019] A method for optimizing the aerodynamic lift force of a pantograph bow head is based on the design that when the airflow passes through the carbon slide plate of the pantograph bow head at high speed, flow separation occurs on the upper and lower sides of the carbon slide plate to form a large-scale vortex. Under the action of the separation vortex, a low-pressure and low-speed area is formed on the upper and lower sides of the carbon slide plate. Figure 1 to Figure 2 As shown, the specific method is to add an airflow regulating convex plate 2 to the carbon slide plate 1 of the pantograph bow head, and improve the flow field structure through the airflow regulating convex plate 2, so that a pressure difference is formed on the upper and lower sides of the carbon slide plate 1, thereby achieving the purpose of increasing the average value of the aerodynamic lifting force of the bow head.

[0020] Specifically, the airflow regulating convex plate 2 is arranged at the bottom of the carbon slide 1, and the airflow regulating convex plate 2 includes a convex plate body 21, which is arranged along the length direction of the carbon slide 1 and protrudes downward from the bottom of the carbon slide 1. Figure 3 As shown, under the influence of the convex plate body 21, the vortex intensity on the lower side of the carbon slide 1 is reduced, and the large-scale vortex is transformed into a small-scale vortex, which significantly improves the pressure environment on the lower side of the carbon slide 1 and reduces the negative pressure intensity on the lower side of the carbon slide 1, thereby achieving the purpose of increasing the average aerodynamic lift force of the bow head.

[0021] Airflow adjustment convex plate design scheme 1 The upper part of the convex plate body 21 is embedded in the main structure of the carbon slide 1; the airflow regulating convex plate 2 also includes a telescopic cylinder, which is arranged in the main structure of the carbon slide 1 and connected to the convex plate body 21. The telescopic cylinder is used to drive the convex plate body 21 to move according to the actual train speed, thereby adjusting the position of the convex plate body 21 and changing the height of the convex plate body 21 protruding downward from the carbon slide 1, so as to achieve different degrees of lift-increasing effects. In this scheme, since only the upper part of the convex plate body 21 is embedded in the main structure of the carbon slide 1, the convex plate body 21 cannot be completely retracted into the carbon slide 1, but the adjustment range of the airflow regulating convex plate 2 can be expanded, which is more suitable for use in higher-speed trains.

[0022] Airflow adjustment convex plate design plan 2 The airflow regulating convex plate 2 is an embedded retractable structure, and also includes a telescopic cylinder, which is arranged in the main structure of the carbon slide 1 and connected to the convex plate body 21. The telescopic cylinder is used to drive the convex plate body 21 to move according to the actual train speed, thereby adjusting the position of the convex plate body 21, protruding the convex plate body 21 downward from the bottom of the carbon slide 1 and changing the height of the convex plate body 21 protruding downward from the carbon slide 1, so as to achieve different degrees of lift-increasing effects. In this solution, the convex plate body 21 can be completely retracted into the carbon slide 1, which can meet the use of low-speed trains.

[0023] The number of airflow regulating convex plates 2 can be adjusted according to the train running speed, running environment or other design conditions. The airflow regulating convex plates 2 can be arranged symmetrically or asymmetrically along the center line of the carbon slide plate 1 to achieve different lift-enhancing effects of the pantograph in different running directions. Embodiment 1

[0024] like Figure 4 As shown in the figure, based on the fluid calculation software Fluent, this embodiment provides the numerical simulation results of the aerodynamic lift force of the original carbon slide (i.e., without the airflow adjustment convex plate) and the improved carbon slide (adjusting the height of the convex plate body protruding downward from the carbon slide to 3 mm). After the airflow adjustment convex plate is installed, the average aerodynamic lift force of the carbon slide increases from 102.9 N to 128.4 N, an increase of 24.8%. Therefore, it can be considered that the airflow adjustment convex plate can improve the flow field structure around the carbon slide and increase its average aerodynamic lift force. Embodiment 2

[0025] like Figure 5 As shown in the figure, this embodiment provides numerical simulation results of the aerodynamic lift force of the original carbon slide plate and the improved carbon slide plate (the height of the convex plate body protruding downward from the carbon slide plate is adjusted to 8 mm). After the airflow adjustment convex plate is installed, the average aerodynamic lift force of the carbon slide plate is increased from 102.9 N to 148.9 N, an increase of 44.7%. Therefore, it can be considered that adjusting the height of the convex plate body can achieve different degrees of lift-enhancing effects. Embodiment 3

[0026] The accuracy of numerical calculation is easily affected by many factors, and due to the limitation of computing resources, the first and second embodiments only provide the numerical simulation results of 0.2 s. Figure 6As shown, this embodiment provides the results of the total lifting force (static contact force of 80 N) of the pantograph head at different train speeds in a certain aviation wind tunnel, which was obtained by installing the original carbon slide plate and the carbon slide plate with the airflow adjustment convex plate (the height of the convex plate body protruding downward from the carbon slide plate is adjusted to 3 mm). At different train speeds, the total lifting force of the pantograph head is improved, especially for the high train speed condition (320 km / h), from 107.4 N to 223.6 N, an increase of 108.2%. Embodiment 4

[0027] like Figure 7 As shown, this embodiment provides the comparison results of the standard values ​​of the carbon slide bow lifting force and contact force of the original carbon slide installed on the pantograph and the airflow adjustment convex plate (the height of the convex plate body protruding downward from the carbon slide is adjusted to 3 mm) at different train speeds. It can be obtained that when the height of the convex plate body protruding downward from the carbon slide is 3 mm, the fitting formula of the bow head lifting force is: in, y It is the lifting force of the bow head; x It is the height of the convex plate body protruding downward from the carbon slide plate.

[0028] and Figure 7 R 2 Represents how well the fitting curve (lift fitting formula) fits the data points. The closer it is to 1, the better.

[0029] The target value of the pantograph-catenary contact force is obtained by consulting the data: According to the above embodiments, it can be known that the increment of the bow head lifting force is proportional to the height of the convex plate body of the airflow regulating convex plate. When the train speed is 220 km / h and below, the lifting force of the original carbon skateboard installed on the pantograph matches the target contact force well. It is recommended to fully retract the convex plate body and appropriately reduce the airbag pressure; when the train speed is higher than 220 km / h, the lifting force of the original carbon skateboard installed on the pantograph can no longer meet the target contact force. When the train speed is between 220 km / h and 400 km / h, it is recommended to adjust the convex plate body height of the airflow regulating convex plate to 1-3 mm, and adjust the airbag pressure appropriately according to the contact force monitoring value; when the train speed is between 400 km / h and 450 km / h, it is recommended to adjust the convex plate body height of the airflow regulating convex plate to 3 mm, the lifting force of the bow head matches the target contact force well, and the airbag pressure can be appropriately reduced; when the train speed exceeds 450 km / h or encounters extremely harsh environments, it is recommended to appropriately increase the convex plate body height of the airflow regulating convex plate to ensure stable current collection by the train.

[0030] When in use, the present invention can be widely applied to pantograph systems of high-speed EMUs and other rail transportation vehicles.

Claims

1. A method for optimizing the pneumatic lifting force of a pantograph head, characterized in that: The method comprises installing an airflow regulating convex plate (2) for improving the flow field structure at the carbon slide plate (1) of the pantograph bow head so as to form a pressure difference between the upper and lower sides of the carbon slide plate (1) to increase the average value of the aerodynamic lifting force of the bow head.

2. A method for optimizing the pneumatic lifting force of a pantograph head according to claim 1, characterized in that: The airflow regulating convex plate (2) is arranged at the bottom of the carbon slide plate (1). The airflow regulating convex plate (2) reduces the vortex intensity on the lower side of the carbon slide plate (1), transforms the large-scale vortex into a small-scale vortex, improves the pressure environment on the lower side of the carbon slide plate (1), reduces the negative pressure intensity on the lower side of the carbon slide plate (1), and thus improves the average value of the aerodynamic lifting force of the bow head.

3. The method for optimizing the pneumatic lifting force of a pantograph head according to claim 2, characterized in that: The airflow regulating convex plate (2) comprises a convex plate body (21) arranged along the length direction of the carbon slide plate (1) and protruding downward from the bottom of the carbon slide plate (1).

4. A method for optimizing the pneumatic lifting force of a pantograph head according to claim 3, characterized in that: The upper portion of the convex plate body (21) is embedded in the main structure of the carbon slide plate (1); the airflow regulating convex plate (2) further comprises a telescopic cylinder arranged in the main structure of the carbon slide plate (1) and connected to the convex plate body (21), and used to drive the convex plate body (21) to move according to the actual train speed so as to change the height of the convex plate body (21) protruding downward from the carbon slide plate (1).

5. The method for optimizing the pneumatic lifting force of a pantograph head according to claim 3, characterized in that: The airflow regulating convex plate (2) is an embedded retractable structure, and further comprises a retractable cylinder which is arranged in the main structure of the carbon slide plate (1) and connected to the convex plate body (21), and is used to drive the convex plate body (21) to move according to the actual train speed so as to protrude the convex plate body (21) downward from the bottom of the carbon slide plate (1) and change the height of the convex plate body (21) protruding downward from the carbon slide plate (1).

6. A method for optimizing the pneumatic lifting force of a pantograph head according to claim 2, characterized in that: The number of airflow regulating convex plates (2) is adjusted according to the train design conditions, including but not limited to the running speed and the running environment.

7. The method for optimizing the pneumatic lifting force of a pantograph head according to claim 2, characterized in that: A plurality of the airflow regulating convex plates (2) are provided, and the plurality of airflow regulating convex plates (2) are arranged symmetrically or asymmetrically along the center line of the carbon slide plate (1) to achieve different lift-increasing effects of the pantograph in different running directions.

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