A new type of turnout for urban rail transit

Abstract

The present application relates to a kind of new type of turnout of urban rail transit, including straight basic rail, curve point rail, straight line point rail, curve basic rail, straight guide rail, side guide rail and combination frog, the curve point rail, curve basic rail and side guide rail adopt guide curve with radius greater than or equal to 680m, the radius of the curve point rail, curve basic rail and side guide rail is identical, the frog angle of the combination frog is less than the frog angle of No. 12 turnout, greater than the frog angle of No. 18 turnout.Its curve radius is greater than or equal to 680m, and the frog angle is less than the frog angle of No. 12 turnout, greater than the frog angle of No. 18 turnout, so that the lateral passing speed and the straight passing speed can be improved, the train comfort index can be guaranteed when the train passes through the turnout at a lateral speed of 70km / h, the lateral passing speed of the turnout can be greater than or equal to 70km / h, the "30 pairs / h" turnaround capacity requirement of domestic 8 A-type car marshalling can be met, and higher demand can be achieved.

Description

Technical Field

[0001] This invention relates to the field of turnout technology, and in particular to a new type of turnout for urban rail transit. Background Technology

[0002] A turnout is a track switch that allows a subway vehicle to switch from one track to another. It is an important component and system integration of the subway track and a key device that affects the speed, stability and safety of train operation.

[0003] 1. Brief description of existing subway turnout technical solutions

[0004] 1) Composition and working principle of turnout

[0005] like Figure 1 As shown, a single turnout includes a straight main rail 1, a curved switch rail 2, a straight switch rail 3, a curved main rail 4, a straight guide rail 5, a lateral guide rail 6, a combined frog 7, and turnout fasteners and connectors. The switch equipment drives the curved switch rail 2 and the straight switch rail 3 to achieve linear displacement, thus ensuring the smooth passage of trains in both the straight and lateral directions of the turnout. Specifically, when the turnout is in the straight direction, the curved switch rail 2 opens, the straight switch rail 3 is in close contact with the curved main rail 4, and the train passes through the straight main rail 1 and the straight switch rail 3; when the turnout is in the lateral direction, the curved switch rail 2 is in close contact with the straight main rail 1, the straight switch rail 3 opens, and the train passes through the curved switch rail 2 and the curved main rail 4.

[0006] 2) Introduction to conventional subway turnouts

[0007] Currently, domestic subway systems mainly use No. 7, No. 9, and No. 12 turnouts to meet the requirements of train track changes and turnarounds. No. 7 turnouts are generally used on depot lines, while No. 9 and No. 12 turnouts are used on the main line. For each turnout device, the higher the number, the smaller the frog angle formed by the straight and lateral directions, the higher the lateral passing speed of the train, and the larger the turnout size. Specific parameters for common turnouts are detailed below:

[0008]

[0009] 2. Existing subway turnout technical solutions are objectively inadequate.

[0010] Subway trains use switches to turn around. The time it takes for a train to pass through a switch and the turnaround capacity of the line are closely related to the lateral passing speed of the switch and the size parameters of the switch: the higher the lateral passing speed of the switch and the smaller the size of the switch, the shorter the time it takes for a train to pass through the switch and the stronger the turnaround capacity of the line.

[0011] Among domestic subway turnouts, the No. 12 turnout has the best turnaround performance, with a lateral throughput speed of 50 km / h and a turnout length of 37.8m, meeting the standard requirement of "30 pairs / h" turnaround capacity under a 6-car A-type train formation. However, with the growth of urban population and the increase in travel frequency, the passenger flow of rail transit has also increased significantly. To meet travel demands, some backbone subway lines in cities have adopted 8-car A-type train formations. Through train efficiency simulation calculations, due to the constraint of the 50 km / h lateral throughput speed, the No. 12 turnout, currently the best turnaround capacity in the subway industry, still cannot achieve the standard "30 pairs / h" turnaround capacity under an 8-car A-type train formation. Furthermore, the No. 12 turnout's frog angle also prevents a significant increase in lateral throughput speed. Although domestic railways have the No. 18 turnout with a higher lateral throughput speed, its frog angle is too small to form a crossover for subway line turnarounds.

[0012] Research revealed that foreign countries have developed European standard No. 14 turnouts for handling large-formation train operations. These turnouts offer improved lateral passing speed and enhanced track turning capacity. However, this equipment cannot be imported and used, primarily due to the following reasons: First, the turnout adopts European standards, and its rail profile and signal interface are incompatible with domestic subway systems. Second, the maximum lateral passing speed of these turnouts is 65 km / h, which still cannot meet the domestic requirement of a turning capacity of "30 pairs / h" for 8-car A-type train formations (based on operational calculations, the required lateral passing speed is 70 km / h). Summary of the Invention

[0013] The purpose of this invention is to address the problem that existing subway turnouts, both domestically and internationally, cannot meet the "30 pairs / h" turnaround capacity requirement for 8-car Type A trains. This invention provides a new type of turnout for urban rail transit, which has higher lateral throughput speed, is compatible with domestic subway standards, has controllable scale, and better stability and durability.

[0014] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0015] A novel turnout for urban rail transit includes a straight main rail, a curved switch rail, a straight switch rail, a curved main rail, a straight guide rail, a lateral guide rail, and a combined frog. The curved switch rail, the curved main rail, and the lateral guide rail adopt a guide curve with a radius greater than or equal to 680m. The curved switch rail, the curved main rail, and the lateral guide rail have the same radius. The frog angle of the combined frog is less than the frog angle of turnout No. 12 and greater than the frog angle of turnout No. 18.

[0016] The curve switch rail, main rail, and lateral guide rail described in this invention have the same radius. These rails utilize a turnout guide curve radius greater than or equal to 680m. This turnout guide curve radius is higher than the 350m guide curve radius of turnout No. 12 and higher than the 561m guide curve radius of European standard turnout No. 14. Furthermore, the frog angle of the combined frog is smaller than that of turnout No. 12 and larger than that of turnout No. 18, ensuring that when a train passes through the turnout at a lateral speed of 70km / h, the train comfort index does not exceed the limit, i.e., it is not subjected to a centrifugal acceleration of 0.556m / s². 2 <0.56m / s 2 The control limit is 0.594 m / s² for the unbalanced centrifugal acceleration increment. 3 <0.6m / s 3 The control limits are set. By adopting the above scheme, the lateral passing speed of the turnout can be greater than or equal to 70 km / h, which can meet the domestic requirement of "30 pairs / h" turnaround capacity for 8-car A-type trains, and can also achieve higher lateral speed requirements.

[0017] As a preferred embodiment of the present invention, the guide curve radius of the curved switch rail, the curved main rail and the lateral guide rail is 680m, which can meet the lateral passing speed of trains of 70km / h, and the turnout size is smaller and the track shape is better met.

[0018] As a preferred embodiment of the present invention, the frog angle of the combined frog is 4°5′8″, corresponding to turnout No. 14.

[0019] As a preferred embodiment of the present invention, the straight main rail, curved main rail, straight guide rail and side guide rail all adopt the CHN60 rail profile, which is more compatible with the wheel tread of domestic vehicles than the European standard UIC60 rail for No. 14 turnout, and can be compatible with domestic subways.

[0020] As a preferred embodiment of the present invention, the combined turnout includes:

[0021] Wing rail one is set in correspondence with the inner lateral guide rail;

[0022] Wing rail two is set to correspond to the inner straight guide rail;

[0023] An alloy steel core rail is located between wing rail one and wing rail two. One end of the alloy steel core rail is located at the intersection of wing rail one and wing rail two, and the other end of the alloy steel core rail is connected to the high manganese steel core rail heel end of fork heel rail one and fork heel rail two.

[0024] The existing frog's point rail is a single unit. Since the point rail tip is the main load-bearing part of the frog, this design divides the point rail into several parts: an alloy steel point rail and two fork-heel point rails. Fork-heel point rails one and two are standard steel rails. The alloy steel point rail, as the main load-bearing component, features high strength, high hardness, and high toughness, significantly improving the material's hardness and wear resistance, and extending its service life. Furthermore, the alloy steel point rail is connected to the fork-heel point rail at the rear end of the point rail using splicing and welding. When the alloy steel point rail is damaged, it can be replaced promptly, while the wing rail and the fork-heel point rail at the rear end of the point rail can continue to be used, saving costs. This combined frog design provides safe support for the new turnout to meet the lateral passing speed requirement of 70 km / h.

[0025] As a preferred embodiment of the present invention, both the first wing rail and the second fork-feet rail are curved, and the curve radius of the first wing rail and the second fork-feet rail is the same as the curve radius of the curved switch rail. That is, the lateral pass-through line of the frog area maintains the same radius curve design as the lateral switch. Compared with the straight frog scheme, this design can reduce the size of the turnout, shorten the train passing time through the turnout, improve the turnaround efficiency, reduce the civil engineering scale, and further reduce civil engineering investment while ensuring driving comfort.

[0026] As a preferred embodiment of the present invention, the front ends of both the curved and straight switch rails are semi-secant. The semi-secant switch rail front end design improves the robustness of the switch rail tip, more effectively distributes the impact of the train wheels, reduces the tip wear rate, and extends the service life of the switch rail by more than 100%.

[0027] As a preferred embodiment of the present invention, an arc-shaped protrusion away from the second wing rail is provided at the intersection of the first wing rail and the second wing rail. An alloy steel inlay block is provided between the arc-shaped protrusion and the alloy steel core rail. The arc-shaped protrusion, the alloy steel core rail, the alloy steel inlay block and the second wing rail are connected.

[0028] This type of combined fork has a wing rail one corresponding to the inner lateral guide rail; a wing rail two corresponding to the inner straight guide rail; and an alloy steel core rail located between the wing rail one and the wing rail two. One end of the alloy steel core rail is located at the intersection of the wing rail one and the wing rail two, and the other end of the alloy steel core rail is connected to the fork base rail one and the fork base rail two, forming the basic structure of the combined fork. The portion of the wing rail one located at the intersection of the wing rail one and the wing rail two has an arc-shaped protrusion away from the wing rail two. This arc-shaped protrusion connects with the alloy steel core rail. Alloy steel inserts are installed between the steel core rails. The arc-shaped protrusion, the alloy steel core rail, the alloy steel inserts, and the wing rails are connected to each other, thereby improving the lateral structural strength of the frog and avoiding the risks of impact, cracking, and breakage of the wing rail due to excessive lateral speed of the train passing through the turnout. Alloy steel inserts are installed on one side of the wing rail. Due to the high strength, high wear resistance, and impact resistance of alloy steel, it can effectively resist the impact of train wheels, thus ensuring the safety of the combined frog when the lateral speed of the turnout increases.

[0029] As a preferred embodiment of the present invention, it includes a turnout sleeper, a rubber pad is provided above the turnout sleeper, an iron pad is provided on the rubber pad, a groove is provided in the middle of the horizontal direction of the rubber pad, and a downward protrusion is provided in the middle of the horizontal direction of the iron pad, the protrusion being adapted to be provided in the groove.

[0030] The thickness of the section of the iron pad that supports the rail in the middle is increased, while the thickness of the section at both ends of the iron pad that anchors the bolts is reduced. In this way, the iron pad will not warp upward after the bolts are pre-tightened. Under the load of the rail and the vehicle, the iron pad will remain horizontal and downward and transmit the force to the rubber pad under the plate. Only then can the rubber pad under the plate provide sufficient rigidity to improve the uneven rigidity of the subway turnout.

[0031] As a preferred embodiment of the present invention, it includes a turnout sleeper, a rubber pad is provided above the turnout sleeper, an iron pad is provided on the rubber pad, and the horizontal center of the entire iron pad and the horizontal center of the upper side of the rubber pad are provided with downward reverse bending deformation.

[0032] The reverse deformation vector provided by the reverse bending deformation is the same as the upward arching displacement of the iron pad after the preload is applied. In this way, after the preload is applied, the upward arching displacement of the iron pad will cancel out the preset reverse bending deformation, thereby avoiding the separation of the iron pad from the rubber pad under the plate during use, and the situation where the rubber pad under the plate cannot continuously provide stiffness for the track.

[0033] In summary, due to the adoption of the above technical solution, the beneficial effects of the present invention are:

[0034] 1. The novel turnout for urban rail transit described in this invention has a curve radius greater than or equal to 680m, and a frog angle less than that of turnout No. 12 and greater than that of turnout No. 18. This enables the improvement of lateral and straight-line passing speeds, ensuring that the train comfort index does not exceed the limit when the train passes through the turnout at a lateral speed of 70km / h. It also enables the turnout to have a lateral passing speed greater than or equal to 70km / h, meeting the domestic requirement of "30 pairs / h" turnaround capacity for 8-car A-type trains, and even achieving higher requirements.

[0035] 2. The novel turnout for urban rail transit described in this invention uses CHN60 steel rails for both the main rail and guide rail, which are compatible with the wheel treads of domestically produced vehicles. The frog uses a combination of forged alloy steel core rails, which extends the frog's service life and provides continuous working conditions for the new No. 14 turnout to achieve a lateral speed of 70 km / h. The lateral alignment of the frog area is designed with a radius curve consistent with that of the switch, reducing the scale of civil engineering and optimizing the required space, further reducing civil engineering investment; the alloy steel core rails can be replaced in a timely manner, saving costs. The stiffness of the area above the turnout sleepers is uniformly designed, resulting in a lower damage rate and improved service life, providing continuous working conditions for the new No. 14 turnout to achieve a lateral speed of 70 km / h. Attached Figure Description

[0036] Figure 1 This is a schematic diagram of the planar structure of a conventional railway turnout.

[0037] Figure 2 This is a schematic diagram of the planar structure of the novel turnout for urban rail transit described in this invention.

[0038] Figure 3 This is a schematic diagram of the planar structure of a combined frog. Figure 1 ;

[0039] Figure 4 This is a schematic diagram of the planar structure of a combined frog. Figure 2 ;

[0040] Figure 5 This is a schematic diagram of the planar structure of the crossover.

[0041] Figure 6 This is a schematic diagram of the stiffness control design at the fastener. Figure 1 ;

[0042] Figure 7 This is a schematic diagram of the stiffness control design at the fastener. Figure 2 ;

[0043] Figure 8 A schematic diagram of stiffness distribution before design to achieve uniform stiffness in the fork area;

[0044] Figure 9A schematic diagram of stiffness distribution after stiffness homogenization design in the fork area;

[0045] Figure 10 This is a comparison of the profiles of CHN60 rails and UIC60 rails used in European standard No. 14 turnouts;

[0046] Figure 11 This is a schematic diagram of the rail support structure.

[0047] Figure 12 This is a schematic diagram of the roller slide system.

[0048] Figure 13 This is a schematic diagram of the anti-jump limit device.

[0049] Figure 14 This is a schematic diagram showing the constraint of the lower jaw of the straight main rail on the curved tip rail;

[0050] Figure 15 This is a schematic diagram of the switch rail being concealed on the side of the main rail;

[0051] Figure 16 This is a schematic diagram of the guard rail installation.

[0052] Icons: 1-Straight main rail; 2-Curved switch rail; 3-Straight switch rail; 4-Curved main rail; 5-Straight guide rail; 6-Side guide rail; 7-Combined frog; 71-Alloy steel core rail; 710-Arched protrusion; 72-High manganese steel core rail heel end; 731-Wing rail one; 732-Wing rail two; 74-Fork heel core rail one; 75-Fork heel core rail two; 76-Alloy steel inlay block; 8-Straight guard rail; 9-Side guard rail; 10-Fork sleeper; 101-Rubber pad; 102-Iron pad; 103-Reverse bending deformation; 113-Rail head lower jaw; 131-Rail bracing structure; 132-Roller slide plate system; 135-Anti-jump limit device; 22-CHN60 rail; 23-UIC60 rail. Detailed Implementation

[0053] The present invention will now be described in detail with reference to the accompanying drawings.

[0054] 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.

[0055] Example 1

[0056] A new type of turnout for urban rail transit, see [link / reference] Figure 2It includes a straight main rail 1, a curved switch rail 2, a straight switch rail 3, a curved main rail 4, a straight guide rail 5, a lateral guide rail 6, and a combined frog 7. The curved switch rail 2, the curved main rail 4, and the lateral guide rail 6 adopt guide curves with a radius greater than or equal to 680m. The radii of the curved switch rail 2, the curved main rail 4, and the lateral guide rail 6 are the same. The frog angle of the combined frog 7 is less than the frog angle of turnout No. 12 and greater than the frog angle of turnout No. 18.

[0057] In this embodiment, the new type of turnout used in urban rail transit is also equipped with a straight guard rail 8, a side guard rail 9, etc. The limiting relationship between the straight guard rail 8 and the straight guide rail 5 can be referred to Figure 16 The limiting relationship between the lateral guard rail 9 and the lateral guide rail 6 and Figure 16 Similarly, it can guide and control the direction of the wheels, reduce wear on the frog rail, and strengthen the frog structure to enhance stability.

[0058] In this embodiment, the curve switch rail 2, the main curve rail 4, and the lateral guide rail 6 have the same radius. The curve switch rail 2, the main curve rail 4, and the lateral guide rail 6 adopt a turnout guide curve radius greater than or equal to 680m. This turnout guide curve radius is higher than the 350m guide curve radius of turnout No. 12 and higher than the 561m guide curve radius of European standard turnout No. 14. Furthermore, the frog angle of the combined frog 7 is smaller than the frog angle of turnout No. 12 and larger than the frog angle of turnout No. 18, ensuring that when the train passes through the turnout at a lateral speed of 70km / h, the train comfort index does not exceed the limit, i.e., it is not subjected to a centrifugal acceleration of 0.556m / s². 2 <0.56m / s 2 The control limit is 0.594 m / s² for the unbalanced centrifugal acceleration increment. 3 <0.6m / s 3 The control limit is set at 70 km / h. This means that by adopting the above scheme, the lateral passing speed of the turnout can be greater than or equal to 70 km / h, meeting the domestic requirement of a 30-pair / h turnaround capacity for 8-car A-type train sets, and even exceeding that requirement.

[0059] When the guide curve radius of the switch rail 2, main rail 4, and lateral guide rail 6 is less than 680m, it cannot meet the lateral speed requirement of 70km / h for trains. When the guide curve radius of the switch rail 2, main rail 4, and lateral guide rail 6 exceeds 680m by too much, it will lead to an excessively large overall size of the turnout, or cause a mismatch in the track alignment due to size limitations. Therefore, the guide curve radius of the switch rail 2, main rail 4, and lateral guide rail 6 is suitable to be between 680m and 695m, with the optimal choice being a guide curve radius of 680m. This satisfies the lateral train passing speed of 70km / h, and the turnout size is smaller, making the track alignment easier to meet.

[0060] In this embodiment, the straight main rail 1, curved main rail 4, straight guide rail 5, and side guide rail 6 all adopt the CHN60 steel rail 22 profile, which is more compatible with the wheel tread of domestic vehicles than the European standard UIC60 steel rail 23 for No. 14 turnouts. The profiles of the two are compared as follows: Figure 10 As shown, it is compatible with domestic subway systems.

[0061] In this embodiment, as Figure 3 As shown, the combined turnout 7 includes:

[0062] Wing rail 731 is set to correspond to the inner side guide rail 6;

[0063] Wing rail 2 732 is set to correspond to the inner straight guide rail 5;

[0064] The alloy steel core rail 71 is located between the first wing rail 731 and the second wing rail 732. One end of the alloy steel core rail 71 is located at the intersection of the first wing rail 731 and the second wing rail 732. The other end of the alloy steel core rail 71 is connected to the high manganese steel core rail heel end 72 of the first fork heel core rail 74 and the second fork heel core rail 75.

[0065] Compared to the existing No. 12 turnout and European standard No. 14 turnout, which both use ordinary high-manganese steel frogs, this embodiment uses a combined frog 7 with forged alloy steel core rails 71. The core rails, made of forged alloy steel, serve as the main load-bearing positions and are spliced ​​or welded to the standard steel core rails 74 and 75. The wing rails are also made of standard steel. The core rails are made of alloy steel base material, which, after forging, heat treatment, and flaw detection, undergoes vibration aging treatment to relieve stress and is then formed and milled on a high-precision milling machine. The wing rails, core rails 74 and 75, all use standard steel rails, meeting the requirements for seamless track welding across sections. The combined fork 7 with forged alloy steel core rail 71 has the characteristics of high strength, high hardness and high toughness, which can significantly improve the hardness and wear resistance of the material, extend the service life, and when the alloy steel core rail 71 is damaged, it can be replaced in time, and the fork and core rail at the rear end of the wing rail and core rail can continue to be used, which can save costs.

[0066] In this embodiment, as Figure 4 As shown, an arc-shaped protrusion 710, away from the second wing rail, can also be provided at the intersection of the first wing rail 731 and the second wing rail 732. An alloy steel inlay block 76 is provided between the arc-shaped protrusion 710 and the alloy steel core rail 71. The arc-shaped protrusion 710, the alloy steel core rail 71, the alloy steel inlay block 76 and the second wing rail are connected.

[0067] This type of combined fork has a wing rail one corresponding to the inner lateral guide rail; a wing rail two corresponding to the inner straight guide rail; and an alloy steel core rail located between the wing rail one and the wing rail two. One end of the alloy steel core rail is located at the intersection of the wing rail one and the wing rail two, and the other end of the alloy steel core rail is connected to the fork-joint core rail one and the fork-joint core rail two, forming the basic structure of the combined fork. The portion of the wing rail one located at the intersection of the wing rail one and the wing rail two is provided with an arc-shaped protrusion 710 away from the wing rail two. The arc-shaped protrusion 710 is connected to the alloy steel core rail. Alloy steel inserts 76 are provided between the steel core rails. The arc-shaped protrusions 710, the alloy steel core rails, the alloy steel inserts, and the wing rails are connected to each other, thereby improving the lateral structural strength of the frog and avoiding the risks of impact, cracking, and breakage of the wing rail due to excessive lateral speed of the train passing through the frog. Alloy steel inserts are installed on one side of the wing rail. Due to the high strength, high wear resistance, and impact resistance of alloy steel, it can effectively resist the impact of the train wheels, so as to ensure the safety of the combined frog after the lateral speed of the turnout increases.

[0068] Compared to the existing No. 12 turnout and European standard No. 14 turnout, which are both straight frog designs, in this embodiment, such as Figure 3 As shown, a curved frog design is adopted. The wing rail 731 and the fork-heel rail 75 are curved, and the curve radius of the wing rail 731 and the fork-heel rail 75 is the same as the curve radius of the curved switch rail 2. That is, the lateral passing line of the frog area maintains the same radius curve design as the lateral passing line of the switch. The curved switch rail 2, the curved main rail 4, the lateral guide rail 6, the wing rail 731 and the fork-heel rail 75 have the same curve radius. While ensuring driving comfort, when the curve radius is 680m, compared with the straight frog scheme, the turnout size can be reduced by about 7m, the train passing time through the turnout can be reduced, the turnout efficiency can be improved, the civil engineering scale can be reduced, and the civil engineering investment can be further reduced by about 3.5 million.

[0069] In this embodiment, the front ends of both the curved switch rail 2 and the straight switch rail 3 are semi-secant type with a secant distance of 4mm. The semi-secant type front end design improves the robustness of the switch rail tip, more effectively distributes the impact of the train wheels, reduces the wear rate of the tip, and extends the service life of the switch rail by more than 1 time.

[0070] The existing European standard No. 14 turnout does not incorporate stiffness uniformity design in the turnout area. Metro turnouts primarily use single-layer iron plate 102 turnout fasteners. These fasteners use iron plates as rail connections and load-bearing components, with under-plate rubber pads 101 providing stiffness. However, after applying pre-tightening force to the anchor bolts, the iron plate arches upwards and separates from the under-plate rubber pad. Therefore, the under-plate rubber pad's ability to adjust track stiffness is limited, and the design value for stiffness control of individual fasteners in the turnout's longitudinal direction fails to meet standards, resulting in poor stiffness uniformity in the metro turnout area. Due to the limited stress on the under-plate rubber pad, its utilization rate is also limited, leading to insignificant stiffness uniformity in the metro turnout area. During operation, this causes wear and spalling in the switch rails, frog rails, and guard rails in the turnout area, increasing wheel-rail interaction forces and increasing the dynamic destructive effect on the turnout structural components when trains pass through, thus affecting the smoothness of train passage through the turnout area.

[0071] In this invention, by altering the structure of the iron pad or pre-setting a reverse bending deformation on the iron pad, the upward arching deformation of the iron pad is eliminated. This allows the iron pad to remain horizontal after pre-tensioning at both ends, and to adhere closely to the rubber pad underneath. Under the load of the rail and vehicle, both can remain horizontal and deform downwards together, ensuring that the rubber pad underneath provides sufficient stiffness. The design value for the stiffness control of each fastener in the longitudinal direction of the turnout meets the standard, ensuring that the stiffness of all fasteners in the entire turnout area is controlled within a certain range, thereby achieving uniform stiffness of the subway turnout. Two different implementation methods are described below:

[0072] The first method is to change the structure of the iron pad. A variable cross-section iron pad can be used, such as... Figure 6 As shown, a new type of turnout for urban rail transit includes a turnout sleeper 10. A rubber pad 101 is provided above the sleeper 10, and an iron pad 102 is provided on the rubber pad 101. The rubber pad 101 has a groove in its transverse middle section, and the iron pad 102 has a downward protrusion in its transverse middle section, the protrusion fitting into the groove. The thickness of the portion of the iron pad supporting the rail in the middle is increased, while the thickness of the portion of the iron pad with anchor bolts at both ends is reduced. This prevents the iron pad from warping upwards after the bolts are pre-tightened. Under the load of the rail and the vehicle, the iron pad remains horizontal and downwards, transmitting the force to the rubber pad below. This allows the rubber pad below to provide sufficient stiffness to ensure that the stiffness control design value of the corresponding fastener meets the standard, thereby improving the uneven stiffness of the subway turnout.

[0073] The second method involves pre-setting a reverse bending deformation in the iron pad. To counteract the upward warping deformation of the iron pad, a pre-set deformation can be made in the middle of the iron pad before applying the tightening torque to the anchor bolts. Figure 7The reverse deformation shown refers to a new type of turnout used in urban rail transit, which includes a turnout sleeper 10. A rubber pad 101 is provided above the sleeper 10, and an iron pad 102 is provided on the rubber pad 101. Both the transverse midpoint of the iron pad 102 and the transverse midpoint of the upper side of the rubber pad 101 have downward reverse bending deformation 103. The reverse deformation vector provided by the reverse bending deformation 103 is the same as the upward arching displacement of the iron pad after applying preload. Thus, after applying preload, the upward arching displacement of the iron pad will cancel out the preset reverse bending deformation, thereby preventing the iron pad from separating from the rubber pad under the plate during use, which would prevent the rubber pad under the plate from continuously providing stiffness to the track. This ensures that the rubber pad under the plate provides sufficient stiffness to meet the design value of the stiffness control of the corresponding fastener, thereby improving the uneven stiffness of the subway turnout. In this embodiment, by modifying the structure of the iron pad, warping deformation of the iron pad is eliminated. Under load, the iron pad and the rubber pad underneath make horizontal contact and deform vertically downwards together, allowing the rubber pad underneath to fully provide stiffness and improving the uniformity of the subway turnout stiffness. It also maintains the consistency of stiffness in different areas of the subway turnout, improving the smoothness of train passage through the turnout area, reducing rail wear, lowering maintenance costs in the turnout area, and improving passenger comfort. The stiffness uniformity design improves the uniformity of the support stiffness of this equipment, enhancing the comfort and stability of trains passing through the turnout. Figure 8 A schematic diagram of the stiffness distribution before designing for uniform stiffness in the fork region. Figure 9 This is a schematic diagram of the stiffness distribution after the stiffness homogenization design of the turnout area. Before the stiffness homogenization design, the stiffness distribution of the turnout area was 73-104 kN / mm, and after the stiffness homogenization design, the stiffness distribution of the turnout area was 73-80 kN / mm.

[0074] Example 2

[0075] This embodiment provides a new type of turnout for urban rail transit. Based on embodiment 1, the turnout can adopt a 4°5′8″ frog angle, corresponding to turnout number 14; the frog angle is between 4°45′49″ of turnout number 12 and 3°10′47″ of turnout number 18, which can form a crossover for subway train turnaround.

[0076] Specifically, the new type of turnout for urban rail transit provided in this embodiment consists of a switch, a connecting part, a combined frog, and a guard rail, forming a single turnout with one straight track and one side track, through which vehicles are guided in two directions.

[0077] like Figure 2The switch includes a base rail, a switch rail, and a connecting part. The base rail and switch rail are provided with a 1:40 rail bottom slope or rail top slope. The connecting part includes a rail support structure 131, an elastic clamp slide plate, a roller slide plate system 132, a limiter structure, a traction point, and an anti-jump limit device 135. The base rail includes a straight base rail 1 and a curved base rail 4. The switch rail includes a straight switch rail 3 and a curved switch rail 2. The straight base rail 1 and the curved switch rail 2 are on the same side. The curved base rail 4 and the straight switch rail 3 are on the same side.

[0078] The switch uses a flexible, bendable switch rail with a concealed tip and a limiter structure at the heel. A rail bracing structure 131 is installed on the outer side of the stock rail, and a roller slide system 132 is installed under the switch rail. Elastic clamping slides supporting the switch rail and stock rail are provided on the surface of the sleepers 10 along the entire length of the switch rail. The rail bracing structure 131 on the outer side of the stock rail improves its anti-tipping capacity. Figure 11 As shown. A roller slide plate system 132 is installed under the switch rail, as follows. Figure 12 As shown. The switch rail heel end adopts a limiter structure to prevent switch rail creep and better transmit temperature force. To ensure close contact between the switch rail and the stock rail and the stability of the track alignment, the switch section is equipped with two traction points. The first traction point has a stroke of 160mm, and the second traction point has a stroke of 70mm, thereby enabling the turnout to operate in both the main line and the siding. When the switch rail and stock rail are in close contact, the lower jaw 113 of the switch rail and the stock rail cooperate to prevent jumping, such as... Figure 14 As shown; the anti-jump limit device 135 is set to be suitable for the roller slide plate system 132 in the repulsion state, such as Figure 13 As shown, anti-slip measures for switch rails can optimize wheel-rail dynamics, prevent or reduce defects such as switch rail arching, and improve operating conditions.

[0079] The switch rail is a flexible, bendable structure. The bottom of the working side rail is planed to reduce the lateral stiffness of the theoretical bending point area, thereby reducing the turning force. The switch rail and the main rail are attached in a vertical concealed-point structure with a concealment depth of 3mm; the curved switch rail 2 and the straight main rail 1 adopt a horizontal concealed-point structure, such as... Figure 15 As shown, the working edge of the straight base rail is horizontally planed by 3mm to improve the robustness of the switch rail. The slope of both the working and non-working edges of the switch rail is 1:4; the slope fit of the close-fitting section of the switch rail, combined with the concealed tip structure, can improve the safety of train reversing and enhance the stability of the area near the tip of the switch rail.

[0080] When a train passes the turnout laterally, the turnout needs to open the lateral direction. At this time, the curved switch rail 2 and the straight main rail 1 are in close contact, while the straight switch rail 3 and the curved main rail 4 are in a state of separation. The train speed when passing the turnout laterally is 70 km / h. When a train passes the turnout straight, the turnout needs to open the straight direction. At this time, the curved switch rail 2 and the straight main rail 1 are in a state of separation, while the straight switch rail 3 and the curved main rail 4 are in close contact. The train speed when passing the turnout straight is 160 km / h.

[0081] like Figure 2 As shown, the connecting part includes a straight guide rail 5 and a side guide rail 6.

[0082] like Figure 2 As shown, the combined frog is located at the intersection of the turnout side rail and the turnout main rail. Guard rails are installed on both sides of the combined frog, inside the stock rail. The connecting section connects the switch and the frog area, which refers to the combined frog 7. Three straight-strand connecting lines and three curved-strand connecting lines are configured in the connecting section. The turnout sleepers are laid laterally under the rails on the ballast bed, and the sleepers 10 are arranged perpendicular to the straight-strand direction throughout the entire length of the turnout.

[0083] like Figure 16 To prevent wheels from derailing, guard rails are installed on both sides of the combined frog, inside the main rail. These guard rails are of a split, grooved design, with their top surface 12mm higher than the top surface of the guide rail. The combined frog is positioned at the intersection of the turnout side rail and the turnout main rail. Given the high traffic density of urban rail transit, alloy steel assembled frogs are used to extend their service life. These alloy steel assembled frogs feature high strength, high hardness, and high toughness. The alloy steel assembled frog's core rail is made of forged alloy steel 71, spliced ​​or welded to the fork heel core rail of the standard fork heel rail. The wing rails are manufactured using online quenched steel rails. The core rail uses alloy steel base material, which, after forging, heat treatment, and flaw detection, undergoes vibration aging treatment to relieve stress and is then formed and milled on a high-precision milling machine.

[0084] like Figure 5 The crossover turnout consists of four sets of single turnouts connected by one set of diamond crossovers. This means that using the new No. 14 turnout not only meets the compatibility requirements of domestic subway systems, but also allows for a lateral throughput speed of 70 km / h, and can form a crossover for subway line turnarounds. Furthermore, it meets the domestic requirement of a 30-pair / h turnaround capacity for 8-car A-type train sets.

[0085] The main dimensions and technical standards of the new No. 14 turnout are as follows:

[0086] 1. Main dimensions of the turnout:

[0087] It adopts a single circular curve, and the front profile of the switch rail is a semi-secant profile with a secant value of 4mm;

[0088] like Figure 2 As shown, the total length of the turnout is L = 46300 mm;

[0089] Front length a = 21927 mm;

[0090] The rear length b = 24373 mm;

[0091] Guide curve radius R = 680m;

[0092] Basic rail length: q = 1955 mm;

[0093] Theoretical total length of the turnout: Lt = 39900 mm;

[0094] Flip angle: α = 4°5′8″;

[0095] Length of curved switch rail 2: l = 14340 mm;

[0096] Single-turn frog toe distance: n = 2751 mm;

[0097] (Acute-angled crossover toe distance: n = 1844 mm; Angle-angled crossover toe distance: n = 3432 mm)

[0098] Single-opening turnout distance: m = 4445 mm;

[0099] (Clearance of acute-angled frog at crossover: n = 2359 mm; Clearance of angular frog at crossover: n = 3432 mm)

[0100] Track gauge: S = 1435 mm.

[0101] 2. Main Technical Standards

[0102] Straight-through speed: V 直 =160km / h;

[0103] Lateral passing speed: V 侧 =70km / h;

[0104] Kinetic energy loss: ω0 = 0.612 km 2 / s 2 The control limit is 0.65 km. 2 / s 2 ;

[0105] Unbalanced centrifugal acceleration: a0 = 0.556 m / s² 2 The control limit is 0.56 m / s. 2 ;

[0106] Unbalanced centrifugal acceleration increment: The control limit is 0.6 m / s. 3 .

[0107] The beneficial effects of this embodiment are mainly reflected in the following aspects:

[0108] I. Applicable to urban rail transit in China. Although China Railway has developed large-number turnouts such as No. 18 and No. 42 turnouts, their frog angles are too small. The frog angle α of No. 18 is 3°10′47″, and that of No. 42 is 1°12′50.13″, making it impossible to assemble them into crossovers for train turnaround. Furthermore, urban environments are complex, limiting route selection freedom, with many underground lines. Using long, large-number turnouts would be too costly and may not have enough space. The new No. 14 turnout has a frog angle α of 4°5′8″, which is smaller than that of the No. 18 turnout, allowing it to be assembled into a crossover and conveniently applied to urban rail transit.

[0109] II. Improved Lateral Turnout Speed. Subway operating speeds are lower than high-speed rail. Domestic No. 12 turnouts already meet the requirement of a straight-through speed of 120 km / h. However, the limiting factor for subway train turnaround capacity is the lateral turnout speed. Currently, for 8A train formation lines, the standard No. 12 turnout basically meets the station-front turnaround capacity of 27-28 pairs / h. The new No. 14 turnout is designed for a straight-through speed of no less than 160 km / h and a lateral passing speed of no less than 70 km / h, representing a lateral speed increase of 20 km / h compared to the No. 12 turnout. This overcomes the technical bottleneck that existing subway turnouts cannot meet the 30 pairs / h turnaround capacity requirement for 8A train formation lines.

[0110] III. Improved Flip Material. Traditional turnouts use high-manganese steel cast frogs. High-manganese steel has low strength, many casting defects, and a short service life. Furthermore, high-manganese steel frog rails are difficult to weld together on-site, and in-plant welding is costly. To further improve the wear resistance and strength of the frog rails, the new No. 14 turnout uses alloy steel assembled frogs. Bainitic steel is a type of steel whose hardness and toughness are greatly improved due to its special crystal structure. The frog rail is made of forged alloy steel spliced ​​or welded to the high-manganese steel frog, and the wing rails are manufactured using online quenched steel rails, significantly improving the frog's hardness and wear resistance, and extending its service life.

[0111] The new type of turnout for urban rail transit described in the above embodiments has the same radius for the curved switch rail 2, curved main rail 4, and lateral guide rail 6. The curved switch rail 2, curved main rail 4, and lateral guide rail 6 adopt a turnout guide curve radius greater than or equal to 680m. Furthermore, the frog angle of the combined frog 7 is smaller than that of turnout No. 12 and larger than that of turnout No. 18, which improves both lateral and straight-line passing speeds. It ensures that when a train passes through the turnout at a lateral speed of 70km / h, the train comfort index does not exceed the limit. This allows the turnout to achieve a lateral passing speed greater than or equal to 70km / h, meeting the domestic requirement of a "30 pairs / h" turnaround capacity for 8-car A-type trains, and even exceeding higher requirements. The main rail and guide rails use CHN60 steel rails, compatible with domestic vehicle wheel treads. The combined frog 7 uses forged alloy steel core rails 71, extending the frog's service life and providing continuous working conditions for the new No. 14 turnout to achieve a lateral speed of 70km / h. The lateral alignment of the frog area with the switch's lateral radius curve design reduces the scale of civil engineering, optimizes the required space, and further reduces civil engineering investment. The alloy steel core rail 71 can be replaced in a timely manner, saving costs. The stiffness uniformity design above the turnout sleeper 10 results in a lower turnout damage rate, improves service life, and provides continuous working conditions for the new No. 14 turnout to achieve a lateral speed of 70km / h.

[0112] The above description is only 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 protection scope of the present invention.

Claims

1. A new type of turnout for urban rail transit, comprising straight basic rails (1), curved switch rails (2), straight switch rails (3), curved basic rails (4), straight guide rails (5), side guide rails (6), turnout sleepers (10) and combined frogs (7), characterized in that, The curved switch rail (2), the curved main rail (4), and the lateral guide rail (6) all adopt a guide curve with a radius of 680m. The front ends of the switch rails of the curved switch rail (2) and the straight switch rail (3) are both semi-secant, with a secant value of 4mm. The curved switch rail (2), the curved main rail (4), and the lateral guide rail (6) adopt a single circular curve. The total length of the turnout is L = 46300mm; the front length is a = 21927mm; the rear length is b = 24373mm; the front length of the straight main rail (1) and the curved main rail (4) is q = 1955mm; Theoretical total length of turnout: Lt=39900mm; Length of curved switch rail (2): l=14340mm; Toe distance of single frog: n=2751mm; Toe distance of acute angle frog of crossover: n=1844mm; Toe distance of angle frog of crossover: n=3432mm; Heel distance of single frog: m=4445mm; Heel distance of acute angle frog of crossover: n=2359mm; Heel distance of angle frog of crossover: n=3432mm; Track gauge: S=1435mm; The straight base rail (1), curved base rail (4), straight guide rail (5) and lateral guide rail (6) all adopt the profile of CHN60 steel rail (22); The combined fork (7) includes: wing rail one (731), wing rail two (732), alloy steel core rail (71), fork heel core rail one (74) and fork heel core rail two (75); Wing rail one (731) is correspondingly set to the inner side guide rail (6); wing rail two (732) is correspondingly set to the inner side straight guide rail (5); both wing rail one (731) and fork-heel rail two (75) are curved, and the curve radius of wing rail one (731) and fork-heel rail two (75) is the same as the curve radius of the curved tip rail (2); the alloy steel core rail (71) is located between wing rail one (731) and wing rail two (732), and one end of the alloy steel core rail (71) is located at the intersection of wing rail one (731) and wing rail two (732). The other end of the alloy steel core rail (71) is connected to the high manganese steel core rail heel end (72) of the fork heel core rail one (74) and the fork heel core rail two (75); an arc-shaped protrusion (710) away from the wing rail two (732) is provided at the intersection of the wing rail one (731) and the wing rail two (732), and an alloy steel inlay block (76) is provided between the arc-shaped protrusion (710) and the alloy steel core rail (71), and the arc-shaped protrusion (710), the alloy steel core rail (71), the alloy steel inlay block (76) and the wing rail two (732) are connected; The frog angle of the combined frog (7) is less than that of turnout No. 12 and greater than that of turnout No. 18; the frog angle of the combined frog (7) is 4°5′8″; the base rail includes the straight base rail (1) and the curved base rail (4), and a rail support structure (131) is provided on the outside of the base rail; the switch rail includes the straight switch rail (3) and the curved switch rail (2), and a roller slide plate system (132) is provided under the switch rail; the heel end of the switch rail adopts a limiter structure; when the base and switch rail are in close contact, the lower jaw (113) of the switch rail and the base rail cooperate to prevent jumping; when they are in a repulsive state, an anti-jump limit device (135) suitable for the roller slide plate system (132) is provided. A rubber pad (101) is provided above the fork sleeper (10), and an iron pad (102) is provided on the rubber pad (101); a groove is provided in the middle of the horizontal direction of the rubber pad (101), and a downward protrusion is provided in the middle of the horizontal direction of the iron pad (102). The protrusion is adapted to be provided in the groove, or the middle of the horizontal direction of the entire iron pad (102) and the middle of the horizontal direction on the upper side of the rubber pad (101) are provided with downward reverse bending deformation (103).

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