Method for braking a railway vehicle, braking system, railway vehicle and train

Abstract

The invention relates to a method for braking a railway vehicle (2, 2') comprising the following steps: first, detecting the level of adhesion of preselected wheels or wheelsets (3) of the railway vehicle (2, 2') or of a train composed of a plurality of railway vehicles (2, 2') by braking these preselected wheels or wheelsets (3) with an increased braking force until the level of adhesion is detected without exceeding a predetermined cumulative time of total braking force, the number of preselected wheels or wheelsets being at least one but less than all the wheels or wheelsets (3), and second, braking the further wheels or wheelsets (3), in particular all the other wheels or wheelsets (3), with a braking force determined by taking into account the detected level of adhesion.

Description

Technical Field

[0001] The present invention relates to a method for braking railway vehicles, a braking system for railway vehicles, a railway vehicle including a braking system, and a train including railway vehicles. Background Technology

[0002] When braking a railway vehicle on a section of track where adhesion has decreased, there is a delay before the decrease in adhesion can be detected. This delay is caused by the fact that when the adhesion between the wheels and the track is determined, there is only a small probability that the braking force can be increased to avoid abrupt changes. In particular, there are regulatory boundaries for the action that limit the braking rise time, slope, or abrupt changes, where the limit depends on the vehicle level, such as the comfort level.

[0003] Due to this delay, the reduction in adhesion on the track section cannot be detected during the deceleration of the rail vehicle before wheel slippage occurs. Therefore, once it is detected during braking, measures can only be taken to counteract the reduction in braking performance as a reaction to wheel slippage. Thus, it is too late to enhance the braking process. Summary of the Invention

[0004] Therefore, the object of the present invention is to solve the above-mentioned problems and to provide a method, a braking system, a railway vehicle and a train that can take measures to resist the reduction of braking performance at an early stage.

[0005] This objective is achieved by a method for braking rail vehicles or trains, wherein the adhesion between the vehicle wheels and the rails is detected at the start of the braking process.

[0006] This process can obtain braking force for detecting the adhesion value of the braked wheelset in a short period of time at the beginning of the braking process, without exceeding the legally prescribed braking force accumulation time.

[0007] According to one aspect of the invention, a method for braking railway vehicles includes the following steps: first, detecting the adhesion level of preselected wheels or wheelsets by braking with increased braking force until adhesion is detected within a predetermined accumulation time of total braking force, wherein the number of preselected wheels or wheelsets is at least one but less than all wheels or wheelsets of a railway vehicle, carriage, or trainset; and second, braking all other wheels or wheelsets with a braking force determined by taking into account the detected adhesion level.

[0008] During this process, the braking force at the wheels or wheelset is adjusted in advance to maintain the legally prescribed cumulative braking force for the entire assembly, while avoiding sudden braking. The pre-defined cumulative time is specifically the legally prescribed establishment time.

[0009] According to an advantageous embodiment of the method, the braking system includes at least two braking devices and a braking controller. The at least two braking devices are configured to brake one wheel or wheel set of a railway vehicle, respectively. The braking controller is configured to control the at least two braking devices. The step of detecting the adhesion level of a pre-selected wheel or wheel set is performed by initiating a first braking process by braking the pre-selected wheel or wheel set with the corresponding braking device at a first time point by the braking controller, and by detecting the current adhesion level between the braked wheel or wheel set and the track during the first braking process by the braking controller. The step of braking another wheel or wheel set is performed by initiating a second braking process by braking the other wheel or wheel set with the corresponding braking device by the braking controller.

[0010] The first braking process should be viewed as a test braking process, used to detect the level of traction early so that other wheels or wheelsets can brake with optimized braking force.

[0011] In other words, due to the initial braking process, the increase in braking force used to detect the adhesion level can be determined more quickly by braking fewer wheels or wheelsets than when all wheels or wheelsets are braked. This is because, for example, when only one wheel or wheelset is braked, the deceleration of the entire railway vehicle is only slight compared to braking all wheels or wheelsets, and it is easy to exceed the legally prescribed cumulative braking force time. The increase in braking force from the initially braked fewer wheels or wheelsets can be determined rapidly, allowing the current adhesion between the wheels of the initially braked wheelsets and the track section to be detected early in the braking process. Subsequently, when at least one additional, and in particular all remaining, wheel or wheelset is braked, the previously detected current adhesion level can be taken into account during the braking of the railway vehicle to provide improved braking performance.

[0012] According to an advantageous embodiment of the method, a wheel or wheel set is braked during the first braking process, particularly as the first wheel or wheel set in the direction of travel, and more particularly as multiple wheel sets of a railway vehicle as the first in the direction of travel.

[0013] In another advantageous embodiment of the method, a second braking process is initiated after a predetermined period of time following the first time point.

[0014] According to another advantageous embodiment of the method, the brake controller includes a wheel slip protection system, and the current adhesion level is detected by the wheel slip protection system.

[0015] In another advantageous embodiment of the method, the braking controller includes an adhesion management system and activates the adhesion management system based on the detected current adhesion level.

[0016] Due to another advantageous limitation of this method, the adhesion management system activates the sanding system.

[0017] According to another advantageous embodiment of the method, the increase in braking force applied by the braking device during the first braking process is determined independently of the increase in braking force applied by the braking device during the second braking process, and in particular, it is determined to be faster.

[0018] According to another aspect of the invention, a braking system for a railway vehicle includes at least two braking devices and a brake controller, the at least two braking devices being configured to brake wheels or wheelsets of the railway vehicle respectively, the brake controller being configured to control the at least two braking devices and being configured to: firstly, initiate a first braking process at a first time point by braking at least one, but less than all, wheels or wheelsets with the corresponding braking devices; detect the current adhesion level between the braked wheels or wheelsets and the track during the first braking process; and initiate a second braking process by braking the additional wheels or wheelsets with the corresponding braking devices, taking into account the detected adhesion level.

[0019] In an advantageous embodiment of the braking system, the brake controller includes a wheel slip protection system configured to detect the current level of adhesion.

[0020] In another advantageous embodiment of the braking system, the braking system includes an adhesion management system configured to manage wheel slip protection strategies.

[0021] In another advantageous embodiment of the braking system, the braking system includes an electrically operated braking device and / or an electromechanically actuated braking device.

[0022] According to another aspect of the invention, a railway vehicle includes at least two wheelsets and a braking system according to the invention.

[0023] According to another aspect of the invention, a train comprises at least two railway vehicles according to the invention.

[0024] In one embodiment, initially only the wheelsets of the foremost vehicle of the train are braked. This reaction is then used to infer the current traction value. After the total braking force of these wheelsets has been established, the remaining wheelsets are also braked. During this process, the braking force intensity at the wheelsets is adjusted in a timely manner to maintain the legally prescribed cumulative braking force rate for total traction. Attached Figure Description

[0025] The invention will then be illustrated by way of embodiments with reference to the accompanying drawings.

[0026] in particular, Figure 1 A train having a railway vehicle equipped with a braking system according to the invention is shown; and Figure 2 A graph illustrating the progression of braking force over time is shown. Detailed Implementation

[0027] Figure 1 The diagram shows a train 1 having four railway vehicles 2 and 2'. Each railway vehicle 2 and 2' includes four wheel sets 3, each wheel set comprising two wheels securely fixed to an axle. In an alternative embodiment, the railway vehicles 2 and 2' have another number of wheel sets 3, with at least two wheel sets 3 provided, or the railway vehicles 2 have individually suspended wheels. Alternatively, the train 1 may also have another number of railway vehicles 2 and 2'. Furthermore, a wheel set 3' is defined as the first in its respective direction of travel in the railway vehicle 2' located at a first end of the train 1 and the railway vehicle 2 located at the end of the train 1 opposite to the first end.

[0028] The railway vehicle 2' is equipped with a braking system 4 according to the invention. The braking system 4 includes a braking device 5, by which the wheel assembly 3 or alternatively, individual wheels can be braked.

[0029] The braking system 4 of railway vehicles 2 and 2' includes electromechanically actuated braking devices 5, wherein railway vehicle 2' also includes electrically actuated braking devices. In alternative embodiments, railway vehicles 2 and 2' are provided with other braking devices, such as hydraulically or pneumatically actuated brakes, and / or not all wheelsets 3 are provided with braking devices 5, but at least two braking devices 5 are provided. In alternative embodiments with separate wheel suspensions, each individual wheel is braked by a separately provided braking device 5.

[0030] The braking system 4 also includes a brake controller 6, which is configured to control the braking devices 5, meaning that the brake controller 6 controls the braking force of each individual braking device 5. The brake controller 6 includes a wheel slip protection system 7 and a grip management system 8. The functions of the wheel slip protection system 7 and the grip management system 8 are integrated into the brake controller 6.

[0031] The wheel slip protection system 7 prevents excessive slippage of the wheels of railway vehicles 2 and 2' on the track by adjusting the braking or acceleration forces of the individual braking devices 5 of the wheelset 3. Specifically, the wheel slip protection system 7 is configured to detect the current level of adhesion between the wheels of the wheelset 3 and the track. The wheel slip protection system 7 identifies wheel slippage of a specific wheel by comparing the rotational speed of that specific wheel with the corresponding rotational speeds of other wheels or the speed of the railway vehicle 2.

[0032] The adhesion management system 8 is configured to manage wheel slip protection strategies. In particular, the adhesion management device of the adhesion management system 8 has two functions: one is to ensure that the available adhesion is utilized, for example by the wheel slip protection system 7, and the other is to increase the available adhesion to a level determined by braking requirements, for example by abrasive or magnetic track brakes.

[0033] In particular, railway vehicles 2 and 2' are equipped with a sanding system, and the adhesion management system 8 activates the sanding system to apply sand to the track to improve braking performance.

[0034] In alternative embodiments, the wheel slip protection system 7 and / or the adhesion management system 8 are separate units, or they are omitted, and the function of detecting the current adhesion level to manage the wheel slip protection strategy is performed by other components of the brake controller 6.

[0035] Figure 2 A graph illustrating the progression of braking force F over time t is shown.

[0036] The vertical axis plots the elapsed time t from the initial time point A during initial braking. The horizontal axis qualitatively plots the different braking forces F.

[0037] The graph represented by b1 illustrates the progression of braking force of the braking device 5 of the braked wheel set 3 during the first braking process, which begins at a first time point A at 0 seconds. In an alternative embodiment, at least one, but fewer than all, of the wheel sets 3 are braked during the first braking process.

[0038] The graph represented by b2 illustrates the progress of braking force of the braking device 5 of the other wheel set 3 being braked during the second braking process, which begins at time B after a predetermined period p following the first time point A. In this embodiment, the predetermined period p is 1 second.

[0039] The graph represented by bt illustrates the progression of the total braking force of the braking device 5 for all wheelsets 3, which is the sum of all individual braking forces.

[0040] At the first time point A, during the first braking process, the brake controller 6 initiates braking only on the pre-selected wheelset 3 (the number of pre-selected wheelsets is at least one, but less than all), specifically only one wheelset 3, until the maximum braking force of the braking device 5 for braking the pre-selected wheelset 3 is reached. Therefore, the increase in braking force of the initially braked wheelset 3 can be rapid because the other wheelsets 3 are not braked, and thus the deceleration of the train 1 will not be excessive and no abrupt movement will occur. However, through the rapid increase in braking force of the initially braked wheelset 3, the current level of adhesion between the wheel and the rail of the initially braked wheelset 3 can be detected in the early stages of braking.

[0041] Following a predetermined time period p, during the second braking process, braking of the other wheelset 3 is initiated via brake controller 6. The predetermined time period p is defined to satisfy the regulatory requirements of UIC (International Union of Railways) and technical specifications (TSI), thereby maintaining the entire deceleration ramp-up time of 3-5 seconds as the legally prescribed cumulative time for total braking force. Therefore, the increase in braking force of the braking device of the initially braked wheelset 3 is determined to reach its maximum braking force within the predetermined time period p, as in... Figure 2 As can be seen in the chart. Also, as... Figure 2 As shown, the maximum overall braking force is reached after 4 seconds. Alternatively, if the current adhesion level can be detected before the maximum braking force is reached, the predetermined period can be terminated immediately after the current adhesion level is detected.

[0042] During operation, a method for controlling the braking system 4 is executed.

[0043] At the first time point A, during the first braking process, braking of the pre-selected wheelset 3 is initiated by the brake controller 6. In particular, braking is initiated on one of the wheelset 3, and more particularly on the wheelset 3' that is the first in the direction of travel. Alternatively, braking is not initiated on the wheelset 3' that is the first in the direction of travel, but rather on another wheelset 3 or on multiple wheelset 3.

[0044] During the braking process of the first braking phase, the current level of adhesion between the wheels of the initially braked wheelset 3 and the track is detected by the brake controller 6, particularly by the wheel slip protection system 7. Alternatively, the current level of adhesion can be detected by another unit of the brake controller 6, which is a separate unit.

[0045] At time B, after a predetermined period p following the first time point A, braking of all other wheel sets 3 (which were not initially braked on) begins during a second braking process to decelerate train 1, in order to at least meet regulatory requirements. During this second braking process, the braking force is determined by considering the detected level of adhesion. Alternatively, braking of only some of the other wheel sets 3 may be initiated, with braking of at least one of them being initiated.

[0046] During the first braking process, the increase in braking force of the braking device 5 of the initially braked wheelset 3 is independent of the increase in braking force of the braking device 5 of the other wheelset 3 during the second braking process. In particular, the increase in braking force of the braking device 5 during the first braking process is faster than the increase in braking force of the braking device 5 during the second braking process. Alternatively, the increase may be similar, or the increase in braking force of the braking device during the second braking process may be faster than the increase in braking force during the first braking process.

[0047] The adhesion management system 8 is activated based on the detected current adhesion level. This means that if necessary due to a low current adhesion level, the adhesion management system 8 can activate, for example, a sanding system to increase the adhesion level and / or adjust the wheel slip protection strategy. In particular, since different low adhesion conditions (e.g., different contaminants) exhibit different behaviors with varying amounts and durations of slippage, different slip control strategies (e.g., adaptive wheel slip protection) are advantageous for these different conditions. However, in cases of very low adhesion, slip control alone is insufficient to maintain the required braking performance due to the low available adhesion; therefore, additional adhesion management devices, such as a sanding system or magnetic track brakes, should be activated to increase the available adhesion.

[0048] On the other hand, if the current adhesion level is sufficient, no specific measures of the adhesion management system 8 are required.

[0049] In order to perform the method according to the invention, the brake controller 6 is configured to initiate braking of the wheelset 3 at a first time point A during the first braking process, detect the current adhesion level between the wheels of the wheelset 3 during the braking period of the first braking process, and, after a predetermined time period p after the first time point A, initiate braking of another wheelset 3 in the second braking process, taking into account the detected adhesion level.

[0050] While the invention has been detailed and described in the accompanying drawings and foregoing description, such description should be considered illustrative or exemplary, not restrictive. The invention as defined in the claims is not limited to the disclosed embodiments. Other modifications will be apparent to those skilled in the art upon reading this disclosure. Such modifications may involve other features known in the art and may be used in place of or appended to features already described herein. In the claims, the word "comprising" does not exclude other elements or steps, and the indefinite articles "a" or "an" do not exclude a plural.

[0051] Reference tag list

[0052] 1 train

[0053] 2 Railway vehicles

[0054] 3-wheel group

[0055] 4. Braking System

[0056] 5. Braking device

[0057] 6. Brake controller

[0058] 7. Wheel slip protection system

[0059] 8. Adhesion Management System

Claims

1. A method for braking railway vehicles (2, 2'), wherein, The braking system (4) of the railway vehicle (2, 2') includes: At least two braking devices (5), said at least two braking devices being configured to brake one wheel or wheel set (3, 3') of the railway vehicle (2, 2') respectively, and A brake controller (6) is configured to control the at least two braking devices (5). The method includes the following steps: First, by braking the preselected wheels or wheelsets (3, 3') of a railway vehicle (2, 2') or a train consisting of multiple railway vehicles (2, 2') with increased braking force, the adhesion level of these preselected wheels or wheelsets (3, 3') is detected until the adhesion level is detected within a predetermined accumulation time of the total braking force, wherein the number of the preselected wheels or wheelsets is at least one, but less than all the wheels or wheelsets (3, 3'), and Second, brake another wheel or wheel assembly (3, 3') with a braking force determined by taking into account the detected level of adhesion. The first braking process is initiated by the brake controller (6) braking the preselected wheel or wheelset (3, 3') with the corresponding braking device (5) at a first time point (A), and the brake controller (6) detects the current adhesion level between the braked wheel or wheelset (3, 3') and the track during the first braking process, performing the step of detecting the adhesion level of the preselected wheel or wheelset (3, 3'); and The second braking process is initiated by the brake controller (6) using the corresponding braking device (5) to brake the other wheel or wheel assembly (3, 3'), thereby performing the step of braking the other wheel or wheel assembly (3, 3'). The increase in braking force applied by the braking device (5) during the first braking process is determined independently of the increase in braking force applied by the braking device (5) during the second braking process, and the increase in braking force during the first braking process is determined to be faster than the increase in braking force of the braking device (5) during the second braking process.

2. The method according to claim 1, wherein, At the first time point (A), brake one wheel or wheel assembly (3, 3').

3. The method according to claim 1, wherein, During the first braking process, the brake is applied as the first wheel or wheel assembly (3, 3') in the driving direction.

4. The method according to any one of claims 1 to 3, wherein, The second braking process is initiated after a predetermined period (p) following the first time point (A).

5. The method according to any one of claims 1 to 3, wherein, The brake controller (6) includes a wheel slip protection system (7), and The current adhesion level is detected by the wheel slip protection system (7).

6. The method according to any one of claims 1 to 3, wherein, The brake controller (6) includes an adhesion management system (8), and The adhesion management system (8) is activated based on the detected current adhesion level.

7. The method according to claim 6, wherein, The adhesion management system (8) activates the sanding system.

8. A braking system (4) for a railway vehicle (2, 2'), comprising: At least two braking devices (5), said at least two braking devices being configured to brake the wheels or wheel sets (3, 3') of the railway vehicle (2, 2') respectively, and A brake controller (6) is configured to control the at least two braking devices (5). in, The brake controller (6) is configured to, First, at a first time point (A), the first braking process is initiated by braking at least one, but less than all, wheels or wheel sets (3, 3') with the corresponding braking device (5); During the first braking process, the current adhesion level between the braked wheel or wheel assembly (3, 3') and the track is detected; Second, considering the detected current adhesion level, a second braking process is initiated by braking another wheel or wheel assembly (3, 3') with the corresponding braking device (5). The increase in braking force applied by the braking device (5) during the first braking process is determined independently of the increase in braking force applied by the braking device (5) during the second braking process, and the increase in braking force during the first braking process is determined to be faster than the increase in braking force of the braking device (5) during the second braking process.

9. The braking system (4) according to claim 8, wherein, The brake controller (6) includes a wheel slip protection system (7) configured to detect the current adhesion level.

10. The braking system (4) according to claim 8 or 9, wherein, The braking system (4) includes an adhesion management system (8) configured to manage wheel slip protection strategies.

11. The braking system (4) according to claim 8 or 9, wherein, The braking system (4) includes an electrically operated brake and / or an electromechanically actuated brake.

12. A railway vehicle (2, 2') comprising at least two wheelsets (3, 3') and a braking system (4) according to any one of claims 8 to 11.

13. A train (1) comprising at least two railway vehicles (2, 2') according to claim 12.

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