KR102599071B1 - rigid bar transition device for high speed electric railroad - Google Patents

Abstract

A high-speed rigid catenary transition device is disclosed. According to the high-speed rigid catenary transition device according to the present invention, the structural stability of the transition device can be improved in response to the trend of increasing speed of electric railways, and the stiffness or elasticity of the catenary catenary and the rigid catenary line are gradually changed to reduce the stress applied to the catenary line. By relieving stress, the speed of the train can be maintained as much as possible.
In addition, the rigidity or elasticity change rate of the transition device can be reduced, the amount of deflection during installation can be reduced, and the separation margin can be increased by insulating the passing frequency of the train and the resonance frequency of the transition device from each other.
In addition, the freedom of construction can be improved by increasing the grip on the tram line and supporting any part of the transition device.

Description

Rigid bar transition device for high speed electric railroad}

The present invention relates to a high-speed rigid catenary transition device, and more specifically, to a high-speed rigid catenary transition device that improves structural stability in response to the trend of higher speeds in electric railways.

In general, electric railways are used by many people due to their advantages of being fast, accurate, and stable compared to other means of transportation. Moreover, as high-speed railways have recently become widely used, they have been in the spotlight as a safe and convenient means of public transportation.

Electric railways, which are attracting attention as a new means of transportation in the 21st century with the opening of high-speed railways, are required to improve the performance, reliability, and safety of tram lines due to the recent increase in speed, large capacity, and shortening of operation time intervals of electric railways.

Here, a tram line can be defined as a general term for tracks such as tram lines and facilities attached thereto that are used to supply power by contacting the current collectors of electric trains running on the tracks.

The power required when a train runs is supplied through a current collector on the tram line and the vehicle's pantograph. The tram lines that supply electricity to the train are classified according to the method of supplying electricity.

Specifically, the overhead catenary system can be divided into an overhead catenary system and a third rail system, and the overhead catenary system is further divided into a rigid catenary system and a suspended catenary system.

Here, the suspension method is a method of catenating a catenary using a catenary line and is generally applied to above-ground sections. The catenary, catenary line, and dropper line must be catenated together, and peripheral devices such as tension control devices are required, so the required catenary height is high. , it has the disadvantage of being complicated and difficult to apply to tunnel sections.

In other words, in order to apply a suspension type tramway to a tunnel section, the cross-sectional area of the tunnel must be significantly increased, resulting in excessive construction costs. Additionally, the installation space is narrow, so daily inspection and maintenance are not easy.

The third rail type is a method of supplying power by installing a feed rail on the road surface or on the side. It has the advantage of being able to be installed in a narrow space such as a tunnel, but due to the nature of the feed rail being placed on the ground, there is no risk of electric shock. Due to the high risk, it is only applied to certain special sections.

On the other hand, the rigid body rigging method integrates the catenary into a rigid body and installs it using a separate structure such as a bracket. It does not require a rigging wire and does not require a separate tension maintenance device, so it can be installed in sections such as tunnels where installation is difficult due to limited space. It is being applied.

In reality, the height of a rigid catenary, including the rigid body and the catenary, is about 90 to 120 mm, and at low voltage (DC 750V or 1500V), considering the support and electrical separation, the required height between the current collection contact of the catenary and the upper ceiling of the tunnel is only about 500mm. do.

Therefore, since the rigid tramway requires a small installation space, construction costs can be greatly reduced in new tunnels, and it is also very advantageous in maintenance work inside the tunnel.

In Korea, rigid catenary is shortened to Rigid Bar and is expressed as R-Bar, and rigid catenary with a cross-sectional shape similar to the letter T is specifically called T-Bar. Although the R-Bar is widely used because it has superior constructability and current collection performance compared to the T-Bar, in Korea, the T-Bar is applied to the DC section and the R-Bar is applied to the AC section.

Since these rigid catenary lines require a relatively high cost to construct, catenary lines using the above-mentioned suspension method are installed on general tram lines, and rigid catenary lines are generally installed only in necessary sections such as tunnels.

In addition, a transition device is installed at the area where the suspended tram line and the rigid tram line are connected to relieve the stress applied to the tram line due to sudden changes in stiffness.

In other words, the transition device is installed in the section where the catenary and the rigid catenary are mutually transitioned inside and outside the tunnel. The most important goal of designing this transition device is to gradually change the stiffness or elasticity of the catenary and the rigid catenary to reduce the stress applied to the catenary. It serves to relieve stress and at the same time maintain the speed of the train as much as possible.

Therefore, the transition device must have a small rate of change in rigidity or elasticity, the amount of deflection when installed must be small, and the passing frequency of the train and the resonance frequency of the transition device must be insulated from each other.

Embodiments of the present invention seek to improve the structural stability of the transition device in response to the trend of higher speeds in electric railways.

In addition, by gradually changing the rigidity or elasticity of the catenary and rigid catenary, it serves to relieve the stress applied to the catenary and maintain the speed of the train as much as possible.

In addition, we aim to reduce the rigidity or elasticity change rate of the transition device and reduce the amount of deflection during installation.

In addition, we want to increase the separation margin by insulating the passing frequency of the train and the resonant frequency of the transition device from each other.

In addition, the goal is to improve the freedom of construction by increasing the grip on the tram line and enabling support for any part of the transition device.

According to one aspect of the present invention, in a high-speed rigid catenary transition device formed by processing a rigid catenary line and installed in a section connecting a catenary line and a rigid catenary line, the transition device is constant along the longitudinal direction of the transition device. A high-speed rigid catenary transition device may be provided, including a plurality of hollow parts formed at intervals, wherein the plurality of hollow parts increase in length from the rigid catenary to the catenary side.

The plurality of hollow parts may have a square shape.

The plurality of hollow portions may be configured so that the height from the bottom of the transition device increases from the suspended catenary side to the rigid catenary side.

The plurality of hollow parts may be configured so that their height decreases as they move from the suspended catenary side to the rigid catenary side.

The minimum height of the parallel portion may be 40 mm or more.

The high-speed rigid catenary transition device according to the present invention is formed at the end of the catenary side and may further include a catenary connection part having the same height as the height of the rigid catenary before processing.

The high-speed rigid catenary transition device according to the present invention is formed at the end of the rigid catenary side and may further include a rigid catenary connection part having the same height as the height of the rigid catenary before processing.

The difference between the passing frequency and resonance frequency of the high-speed train passing through the transition device may be greater than 10%.

Embodiments of the present invention can improve the structural stability of the transition device in response to the trend of higher speeds in electric railways.

In addition, by gradually changing the stiffness or elasticity of the catenary and rigid catenary, it serves to relieve the stress applied to the catenary and can maintain the speed of the train as much as possible.

In addition, the rigidity or elasticity change rate of the transition device can be reduced and the amount of deflection during installation can be reduced.

Additionally, the separation margin can be increased by insulating the passing frequency of the train and the resonant frequency of the transition device from each other.

In addition, the freedom of construction can be improved by increasing the grip on the tram line and supporting any part of the transition device.

1 is a cross-sectional view of a rigid catenary according to an embodiment of the present invention.
Figure 2 is a side view of a rigid catenary transition device for low and medium speeds according to an embodiment of the present invention.
Figure 3 is an image showing the results of finite element analysis of a rigid catenary transition device for medium and low speeds according to an embodiment of the present invention.
Figure 4 is a side view of a high-speed rigid catenary transition device according to an embodiment of the present invention.
Figure 5 is a side view showing an example of actual specification application of a high-speed rigid catenary transition device according to an embodiment of the present invention.
Figure 6 is an image showing the results of finite element analysis of a high-speed rigid catenary transition device according to an embodiment of the present invention.
Figure 7 is an image comparing the stress distribution of the high-speed rigid catenary transition device and the mid- to low-speed rigid catenary transition device according to an embodiment of the present invention.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the attached drawings. However, the present invention is not limited to the embodiments described herein and may be embodied in other forms. Rather, the embodiments introduced herein are provided so that the disclosure will be thorough and complete, and so that the spirit of the invention can be sufficiently conveyed to those skilled in the art. Like reference numerals refer to like elements throughout the specification.

Figure 1 is a cross-sectional view of a rigid catenary according to an embodiment of the present invention, Figure 2 is a side view of a rigid catenary transition device for medium and low speeds according to an embodiment of the present invention, and Figure 3 is a mid-low speed catenary transition device according to an embodiment of the present invention. This image shows the results of finite element analysis of the fast-acting rigid catenary transition device.

Referring to Figures 1 to 3, the rigid catenary 50 according to the present invention includes a pantograph (not shown) installed on top of a railroad car (not shown) and a catenary 54 that supplies current through electrical contact, and the catenary ( It consists of a rigid body 52 coupled to 54). The current carried by the rigid catenary 50 is supplied for the operation of the train through the pantograph, and the rail is used as a return line.

In general, the rigid catenary 50 is connected and installed using 12 m as a unit, and can be installed at a height that reaches the pantograph by using brackets (not shown) and support clamps (not shown) provided at regular intervals. At this time, the rigid body 52 is provided with side protrusions 52a on both sides of the upper part, and the support clamp supports the side protrusions 52a.

As mentioned above, because the rigid catenary line 50 requires a relatively high cost to construct, it is common to install a catenary line on a general catenary line, and to install the rigid catenary line only in necessary sections such as tunnels.

At this time, a transition device whose rigidity increases from the catenary catenary to the rigid catenary (50) may be provided between the catenary and the rigid catenary (50). Figure 2 shows a representative 120 km/h class rigid catenary transition device (T) for medium and low speeds.

The length of the medium-low speed rigid catenary transition device (T) may be about 5 m to 10 m, and is installed in the connecting section between the catenary line (catenary line), that is, the suspended catenary line and the rigid catenary line (50).

The rigid catenary transition device (T) for medium and low speed gradually changes the difference in stiffness between the suspended catenary and the rigid catenary (50), and reduces the load (stress) applied to the catenary at the connection point due to the sudden change in stiffness. It plays a mitigating role.

As shown in Figure 2, the medium-low speed rigid catenary transition device (T) can be manufactured by machining the upper part of a general rigid catenary (50). Specifically, the medium-low speed rigid catenary transition device (T) includes a plurality of cutting portions (Tn), and the cutting portion (Tn) may be configured so that the cutting depth decreases as it moves toward the rigid catenary (50). . By providing the cutting portion (Tn), the bending rigidity of the rigid catenary transition device (T) for medium and low speeds is reduced, thereby increasing flexibility.

In other words, the shape of the 120 km/h class mid-to-low speed rigid catenary transition device (T) can be configured to relieve rigidity or elasticity by gradually removing some mass from the rigid catenary at regular intervals, as shown in FIG. 2.

The results of finite element analysis of the rigid catenary transition device (T) for medium and low speeds are shown in Figure 3. As a result of evaluating the characteristics through finite element analysis of the rigid catenary transition device (T) for medium and low speed under 5m cantilever conditions, the natural deflection due to its own weight is 21.9mm, the deflection when a load of 100N is applied is 61.9mm, and the vertical resonance frequency is 4.4Hz and 14.2. It is Hz.

Among them, the vertical resonance frequency is 6.7Hz, which is a passing frequency of 120km/h. The primary vertical resonance frequency of 4.4Hz is stable because a 52% resonance frequency margin is secured, but the secondary vertical resonance frequency of 14.2Hz is stable. The passing frequency of 250km/h is close to 13.9Hz, so structural destruction due to the resonant frequency may occur during long-term exposure.

Therefore, in the case of high-speed applications, design changes are necessary to secure a margin for the resonance frequency.

Figure 4 is a side view of a high-speed rigid catenary transition device according to an embodiment of the present invention, and Figure 5 is a side view showing an example of actual specification application of a high-speed rigid catenary transition device according to an embodiment of the present invention. 6 is an image showing the results of finite element analysis of a high-speed rigid catenary transition device according to an embodiment of the present invention. Figure 7 is an image comparing the stress distribution of the high-speed rigid catenary transition device and the mid- to low-speed rigid catenary transition device according to an embodiment of the present invention.

Referring to Figures 1 to 7, the high-speed rigid catenary transition device 100 according to an embodiment of the present invention includes a plurality of devices formed at regular intervals apart from each other along the longitudinal direction of the high-speed rigid catenary transition device 100. It may include hollow parts 110a, 110b, and 110c.

And at the end of the catenary side, a catenary connection part 101 having the same height as the height of the rigid catenary before processing is formed, and at the end of the catenary side, a rigid catenary connection part 103 having the same height as the height of the rigid catenary before processing is formed. can be formed.

Here, the plurality of hollow parts 110a, 110b, and 110c may be configured to increase in length from the rigid catenary toward the catenary. Here, the spacing between the plurality of hollow parts 110a, 110b, and 110c may be the same. The shapes of the plurality of hollow parts 110a, 110b, and 110c may vary, but it is preferable that they have a substantially square shape to ensure convenience in design and processing.

Specifically, to design the structure of a 250 km/h high-speed rigid catenary transition device, design optimization was performed by performing a sensitivity analysis according to the length and height of each hollow part (110a, 110b, 110c) as shown in Figures 4 and 5. . The design goal here is to minimize the amount of deflection and secure the resonance frequency separation margin.

In order to achieve this design goal, the plurality of hollow parts 110a, 110b, and 110c may be configured so that the height from the bottom of the transition device increases from the suspended catenary side to the rigid catenary side.

In addition, the plurality of hollow parts (110a, 110b, 110c) may be configured so that their own heights increase from the suspended catenary side to the rigid catenary side.

In order to gradually change the stiffness (or elasticity) between the catenary and the rigid catenary, the part connected to the catenary should have low rigidity, and the part connected to the rigid catenary should have high rigidity.

The connection to the rigid catenary is made with a connecting bracket, and since it is supported by a support clamp, it generally has the highest rigidity. To summarize the structural characteristics of the transition device, it can be considered a cantilever. The stiffness of the cantilever can be expressed as follows:

(k: Stiffness, E: Young's modulus, I: Second moment of inertia, l: Length, b: Width, h: Height)

Because the suspended catenary side of the hollow portion (110a, 110b, 110c) requires low rigidity, the height from the bottom must be small and the length must be large. Conversely, the rigid catenary side requires high rigidity, so the height from the bottom must be large and the length must be short. do.

In order to secure flexibility (mm/N), which is one of the main characteristics to be considered for the catenary side part, the concentrated mass formed by the catenary connection part 101 must be added to the low rigidity to ensure sufficient characteristics. And the rigid catenary connection part 103 is made tall and short in length in order to maintain rigidity similar to that of the rigid catenary.

The design configuration shown in Figures 4 and 5 includes lengths a, b, c, d and heights a', b', and c' from the bottom to design progressive stiffness. If the stiffnesses at the section widths a, b, c, and d are ka, kb, kc, and kd, the magnitude of the stiffness is ka < kb < kc < kd.

In order to ensure flexibility in the above design, the length a of the part connected to the suspended catenary must be long, and the length c must be short because it must have a rigidity similar to that of the rigid catenary. The design for length must satisfy a > b > c for changes in flexibility and gradual stiffness.

The height from the bottom must gradually increase in order to change stiffness, and satisfies the relationship a’< b’< c’. Here, the heights of the hollow portions 110a, 110b, and 110c are also configured to satisfy the relationship a''>b''>c''.

a' can be configured to be at least 40 mm or more for the height of the space of the bolt part (not shown) securing the catenary 54, but in the case of the high-speed rigid catenary transition device 100 according to this embodiment, the hollow part ( 110a, 110b, 110c) The grip strength is strengthened by the upper horizontal bar, so there is no need for separate bolt fastening. And in this case, a’ is lowered, allowing H to be lowered as well, resulting in lighter weight.

The height H is 110mm for medium and low speeds, and can be designed within 100~120mm for high speeds.

The design adjusts design variables to match the speed of high-speed trains, secures sufficient separation margin between passing frequency and resonant frequency, and aims for a minimum of ±10%. Furthermore, it is desirable to secure ±15% or more to secure a design safety factor of 1.5 times. An example of an actually applied design specification that satisfies these design conditions is shown in FIG. 5.

An image reflecting the results of finite element analysis of the above design is shown in Figure 6. The results show that the natural deflection due to self-weight is 25.5mm, the deflection when a load of 100N is applied is 30.5mm, and the vertical resonance frequency is 4.1Hz and 16.5mm. It is Hz. Among them, the secondary vertical resonance frequency secured a 20% resonance frequency margin at a passing frequency of 13.9Hz at 250 km/h.

With respect to the representative design structure of the high-speed rigid catenary transition device 100, the results of comparing the stress distribution of the high-speed rigid catenary transition device 100 with that for medium and low speed according to the amount of deflection and the pushing force of the pantograph are shown in FIG. there is.

The same conditions as the pushing force of 800N were added to the bottom of the transition device, and as a result of comparing the characteristics with the transition device for medium and low speeds, the maximum stress was 127 MPa for the transition device for medium and low speeds shown in Figure 7(a), and the stress on the vertical bar of the transition device While concentration appeared throughout, in the case of the high-speed rigid catenary transition device 100 shown in Figure 7(b), the maximum stress was only 92 MPa at the second vertical bar at the end of the transition device.

That is, in the case of the high-speed rigid catenary transition device 100, the stress distribution due to the upward force of 800N was much better distributed because it was supported by the upper horizontal bar. If the pressing force becomes higher, the stress distribution of the transition device for low and medium speeds approaches the yield stress, increasing the possibility of damage.

In addition, it was confirmed that the high-speed rigid catenary transfer device 100 does not require a separate bolt device to grip the catenary 54 with a high grip force, and it is possible to reduce the weight. Based on stress, it can be predicted that the high-speed rigid catenary transition device 100 has a stress reduction effect of 28% and thus has excellent durability against long-term exposure to pressing force.

And unlike before, the upper horizontal bar remains as is without being cut, so any part can be clamped with a support clamp, which has the effect of improving construction freedom.

In other words, the high-speed rigid catenary transition device 100 according to the present invention has structural characteristics required for the transition device, such as deflection amount, resonance frequency separation margin, excellent grip, gradual change in rigidity, no need for bolt fastening for catenary grip, and freedom of construction. It can be seen that it shows superior characteristics than those for medium and low speeds due to the securing of power.

According to the high-speed rigid catenary transition device according to the embodiments of the present invention described so far, the structural stability of the transition device can be improved in response to the trend of higher speeds in electric railways, and the stiffness or elasticity of the catenary and rigid catenary can be gradually increased. By changing it to play a role in relieving the stress applied to the tram line, the speed of the train can be maintained as much as possible.

In addition, the rigidity or elasticity change rate of the transition device can be reduced, the amount of deflection during installation can be reduced, and the separation margin can be increased by insulating the passing frequency of the train and the resonance frequency of the transition device from each other.

In addition, the freedom of construction can be improved by increasing the grip on the tram line and supporting any part of the transition device.

Although the present invention has been described above with reference to an embodiment, those skilled in the art may make various modifications and changes to the present invention without departing from the spirit and scope of the present invention as set forth in the claims described below. You can do it. Therefore, if the modified implementation basically includes the elements of the claims of the present invention, it should be considered to be included in the technical scope of the present invention.

100: High-speed rigid catenary transition device
101: Suspension catenary connection part
103: Rigid catenary connection part
110a, 110b, 110c: hollow section

Claims (8)

In the high-speed rigid catenary transition device, which is formed by processing a rigid catenary line and installed in a section connecting a catenary line and a rigid catenary line,
It includes an upper horizontal bar having the same height from the suspended catenary connection part to the rigid catenary connection part, and a plurality of hollow parts formed at regular intervals from each other along the longitudinal direction of the transition device,
A high-speed rigid catenary transition device, characterized in that the plurality of hollow portions increase in length from the rigid catenary to the catenary side. According to paragraph 1,
A high-speed rigid catenary transition device, characterized in that the plurality of hollow parts are formed in a square shape. According to paragraph 1,
The plurality of hollow parts,
A high-speed rigid catenary transition device, characterized in that the height from the bottom of the transition device increases as it moves from the suspended catenary side to the rigid catenary. According to paragraph 1,
The plurality of hollow parts,
A high-speed rigid catenary transition device, characterized in that the height of the hollow portion decreases as it moves from the suspended catenary side to the rigid catenary. According to paragraph 1,
A high-speed rigid catenary transition device, characterized in that the height (a') from the bottom of the transition device to the hollow part is at least 40 mm or more. According to paragraph 1,
A high-speed rigid catenary transition device further comprising a catenary connection part formed at an end of the catenary side and having the same height as the height of the catenary before processing. According to clause 5,
A high-speed rigid catenary transition device further comprising a rigid catenary connection portion formed at an end of the rigid catenary side and having the same height as the height of the rigid catenary before processing. According to any one of claims 1 to 7,
A high-speed rigid catenary transition device, characterized in that the difference between the passing frequency and resonance frequency of the high-speed train passing through the transition device is greater than 10%.

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