Air backup brake system and locomotive

Abstract

This invention relates to an air backup braking system and a locomotive. The system includes: a backup pressure regulating valve, a primary braking cylinder, a backup brake valve, a backup equalizing cylinder, and a backup relay valve. Main air is connected to the train pipe via the backup pressure regulating valve, backup brake valve, backup equalizing cylinder, and backup relay valve. The relay valve connects the main air supply to the train pipe via the backup relay valve, and outputs train pipe pressure based on pressure changes in the backup equalizing cylinder. The backup brake valve has a release position, a primary braking position, a neutral position, and a braking position. In the release position, it connects the primary braking cylinder to the atmosphere and the main air supply to the primary braking cylinder. In the primary braking position, it connects the primary braking cylinder to the backup equalizing cylinder. In the neutral position, all air passages are cut off. In the braking position, it connects the backup equalizing cylinder to the atmosphere. This invention solves the technical problem of inaccurate pressure reduction control during primary braking.

Description

Technical Field

[0001] This invention belongs to the field of rail transit technology, and particularly relates to an air backup braking system and locomotive. Background Technology

[0002] my country's traditional air backup braking system is used for emergency operation in the event of an electro-pneumatic brake failure mode, and its functionality is not as complete as that of the electro-pneumatic brake. Because my country's existing air backup braking system uses pure air braking, the decompression of the backup equalizing cylinder is controlled by adjusting the time the backup brake valve handle is moved to the brake position, thereby controlling the train pipe. However, when freight locomotives in my country are traction vehicles, initial braking is used for speed regulation on the track, which involves controlling the train pipe decompression by 50±5 kPa. The initial braking decompression is small, while the locomotive braking system has requirements for the decompression rate. The commonly used braking decompression rate is 20 kPa / s, and the decompression is often completed within 1-2 seconds. This decompression time is difficult for the driver and crew to control precisely, causing inconvenience for speed regulation of freight locomotives in air backup braking mode. Summary of the Invention

[0003] To address the shortcomings of related technologies, this invention provides an air backup braking system that solves the technical problem of inaccurate pressure reduction control during initial braking.

[0004] According to one aspect of this application, an air backup braking system is provided. In one possible embodiment, the system includes: a backup pressure regulating valve, a primary air cylinder, a backup brake valve, a backup equalizing air cylinder, and a backup relay valve; the main air supply is connected to the backup pressure regulating valve, the backup brake valve, the backup equalizing air cylinder, and the backup relay valve; the main air supply is connected to the train pipe via the backup relay valve, and the backup relay valve outputs the train pipe pressure according to the pressure change of the backup equalizing air cylinder.

[0005] The backup brake valve has a release position, an initial braking position, a neutral position, and a braking position, and the backup brake valve has ports A1, A2, A3, A4, A5, and A6.

[0006] When the system is in the relief position, ports A1 and A4 communicate to establish a pathway between the primary air cylinder and the atmosphere; ports A3 and A6 communicate to establish a pathway between the main air supply and the primary air cylinder; ports A2 and A5 are disconnected.

[0007] During the initial processing stage, ports A1 and A5 communicate to connect the initial processing air cylinder and the backup equalizing air cylinder; ports A2, A3, A4, and A6 are disconnected.

[0008] In the neutral position, all airways are cut off;

[0009] When in the braking position, ports A2 and A6 communicate, while ports A1, A3, A4, and A5 are disconnected, thus establishing a connection between the backup equalizing air cylinder and the atmosphere.

[0010] In one possible implementation, when the backup brake valve is in the initial position, the initial air cylinder is connected to the backup equalizing air cylinder, the backup equalizing air cylinder supplies air to the initial air cylinder, and the backup equalizing air cylinder depressurizes.

[0011] In one possible implementation, it further includes: a switching valve, wherein terminals C1 and C2 of the switching valve are respectively connected to the output terminals of the backup pressure regulating valve and the output terminals of the equalizing air cylinder, and the switching valve has ports A1 and A2; the switching valve is configured such that: when the pressure at terminal C1 is 55 kPa or more greater than the pressure at terminal C2, ports A1 and A2 of the switching valve are cut off; otherwise, ports A1 and A2 are connected.

[0012] Among them, the A1 port of the switching valve is connected to the primary air cylinder, and the A2 port is connected to the A1 port of the backup brake valve (103).

[0013] In one possible implementation, the backup equalizing air cylinder is depressurized by 50 kPa.

[0014] In one possible implementation, it further includes: a potentiometer and a pressure valve, wherein terminals C1 and C2 of the pressure valve are respectively connected to the output terminals of a backup pressure regulating valve and a balancing cylinder, and the pressure valve is configured to output a linear displacement based on a comparison between the pressure output by the backup pressure regulating valve and the pressure value of the balancing cylinder, the linear displacement corresponding to the electrical signal of the potentiometer.

[0015] In one possible implementation, the volume relationship between the initial air cylinder and the backup equalizing air cylinder is also included, calculated using the gas state equation, so that the pressure reduction of the backup equalizing air cylinder is 50 kPa.

[0016] In one possible implementation, the volume relationship between the primary air cylinder and the backup equalizing air cylinder is calculated using the gas state equation; assuming the volume of the backup equalizing air cylinder is V1 and the brake constant pressure is 600 kPa, then the volume of the primary air cylinder is V2 = (1 / 11) * V1.

[0017] In one possible implementation, the communication path between the primary equalizing air cylinder and the backup equalizing air cylinder is blocked, so that the decompression rate of the backup equalizing air cylinder during initial braking does not exceed the decompression rate of the backup equalizing air cylinder during normal braking by 10 kPa / s-40 kPa / s, so that the locomotive will not cause emergency braking.

[0018] According to one aspect of this application, a locomotive is provided that includes an air backup braking system according to any of the above.

[0019] Based on the above technical solution, the air backup braking system of the present invention can achieve precise pressure control of the train braking system under the initial braking conditions of the train, so as to ensure the accuracy of braking force and the stability of braking response. Attached Figure Description

[0020] The accompanying drawings, which are included to provide a further understanding of the invention and form part of this application, illustrate exemplary embodiments of the invention and, together with their description, serve to explain the invention and do not constitute an undue limitation thereof. In the drawings:

[0021] Figure 1 A diagram showing the air circuit connection of an air backup braking system according to one embodiment;

[0022] Figure 2 This is a diagram showing the air circuit connection of an air backup braking system according to another embodiment.

[0023] In the picture:

[0024] 101. Backup pressure regulating valve; 102. Primary air cylinder; 103. Backup brake valve; 104. Backup equalizing air cylinder; 105. Backup relay valve; 106. Switching valve; 107. Potentiometer; 108. Pressure valve. Detailed Implementation

[0025] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0026] In the description of this invention, it should be understood that the terms "center", "lateral", "longitudinal", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0027] The terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first," "second," or "third" may explicitly or implicitly include one or more of that feature.

[0028] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal communication between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0029] To address the problem of inaccurate decompression control during initial braking in existing technologies, this application provides an air backup braking system.

[0030] See Figure 1 In one possible implementation, the air backup braking system includes: a backup pressure regulating valve 101, a primary braking cylinder 102, a backup brake valve 103, a backup equalizing cylinder 104, and a backup relay valve 105; the main air supply is connected to the train pipe via the backup pressure regulating valve 101, backup brake valve 103, backup equalizing cylinder 104, and backup relay valve 105; the main air supply to the relay valve is connected to the train pipe via the backup relay valve 105, and the backup relay valve 105 outputs train pipe pressure according to the pressure change of the backup equalizing cylinder 104; wherein, the backup brake valve 103 has a release position, a primary braking position, and a neutral position. In the neutral position, the air passages are cut off. In the release position, ports A1 and A4 communicate to connect the primary air cylinder to the atmosphere; ports A3 and A6 communicate to connect the main air passage to the primary air cylinder 102, and ports A2 and A5 are cut off. In the primary position, ports A1 and A5 communicate to connect the primary air cylinder 102 to the backup equalizing air cylinder 104, and ports A2, A3, A4, and A6 are cut off. In the neutral position, all air passages are cut off. In the braking position, ports A2 and A6 communicate to connect the backup equalizing air cylinder 104 to the atmosphere, and ports A1, A3, A4, and A5 are cut off.

[0031] Figure 1 In the middle, the a, b, c and d positions of the backup brake valve 103 are respectively: release position, initial braking position / initial braking position, neutral position and braking position.

[0032] In the above scheme, the backup pressure regulating valve 101 is set to adjust the set pressure of the backup equalizing air cylinder 104 during backup braking.

[0033] The backup equalizing air cylinder 104 is used to store the pressurized air in the equalizing pipe.

[0034] In the above scheme, the initial pressure regulating cylinder 102 is used to reduce the pressure of the backup equalizing cylinder 104 during initial braking. The backup brake valve 103 has four operating positions: release position, initial pressure regulating position, neutral position, and braking position, allowing the system to adjust pressure under different operating states to ensure the flexibility and response speed of the braking system. In the release position, ports A1 and A4 communicate, ports A3 and A6 communicate, and ports A2 and A5 are disconnected; in the initial pressure regulating position, ports A1 and A5 communicate, and ports A2, A3, A4, and A6 are disconnected; in the neutral position, all air passages are cut off; in the braking position, ports A2 and A6 communicate, and ports A1, A3, A4, and A5 are disconnected. The pressure reduction of the train pipe can be controlled through these four positions.

[0035] The backup relay valve 105 outputs train pipe pressure based on the pressure change of the backup equalizing air cylinder 104.

[0036] In one possible implementation, when the backup brake valve 103 is in the initial position, the initial air cylinder 102 is connected to the backup equalizing air cylinder 104, the backup equalizing air cylinder supplies air to the initial air cylinder, and the backup equalizing air cylinder depressurizes.

[0037] In the above scheme, the initial position design of the backup brake valve 103 is used to quickly adjust the pressure between the two air cylinders, so that the braking system can respond quickly, while ensuring the stability and continuity of the braking force.

[0038] In one possible implementation, the backup equalizing air cylinder is depressurized by 50 kPa.

[0039] The above scheme takes into account the precise pressure control required by the train braking system under specific conditions to ensure the accuracy of braking force and the stability of braking response.

[0040] In one possible implementation, the volume relationship between the primary air cylinder 102 and the backup equalizing air cylinder 104 is calculated using the gas state equation, such that the pressure reduction of the backup equalizing air cylinder is 50 kPa.

[0041] In the above scheme, through precise calculation and design, it is ensured that the backup equalizing air cylinder provides appropriate pressure reduction during braking, thereby achieving the optimal braking effect.

[0042] The A2 port of the backup pressure regulating valve 101 communicates with the A3 port of the backup brake valve 103, the A1 port of the backup brake valve 103 communicates with the primary air cylinder 102, the A2 and A4 ports of the backup brake valve 103 communicate with the atmosphere, and the A5 and A6 ports of the backup brake valve 103 communicate with the backup equalizing air cylinder 104 and the C1 port of the relay valve 105.

[0043] When the handle of the backup brake valve 103 is in the release position, it connects the main air supply after pressure regulation by the backup pressure regulating valve 101 with the backup equalizing air cylinder, controlling the backup equalizing air cylinder 104 to rise to a constant pressure. The relay valve 105 outputs the train pipe pressure according to the pressure change of the backup equalizing air cylinder, and the primary air cylinder 102 connects with the exhaust passage of the atmosphere to prepare for the initial braking. When the handle is in the initial position, the primary air cylinder 102 connects with the passage controlling the backup equalizing air cylinder 104. The volume of the primary air cylinder 102 can reduce the pressure of the backup equalizing air cylinder by 50 kPa, realizing precise pressure reduction of the backup equalizing air cylinder, thereby achieving precise control of the initial braking. When the handle is in the neutral position, all air passages are cut off, and the backup equalizing air cylinder 104 and the main air supply are pressure maintained. When the handle is in the braking position, it connects the exhaust passage of the backup equalizing air cylinder 104 with the atmosphere to realize the service braking function.

[0044] In the above scheme, the backup brake valve can control the decompression rate of the backup equalizing air cylinder by moving back and forth between the brake position and the neutral position.

[0045] In one possible implementation, the volume relationship between the primary air cylinder and the backup equalizing air cylinder is calculated using the gas state equation; assuming the volume of the backup equalizing air cylinder is V1 and the brake constant pressure is 600 kPa, then the volume of the primary air cylinder is V2 = (1 / 11) * V1.

[0046] The above scheme takes into account the volume ratio between different air cylinders in order to achieve more precise pressure regulation and control while maintaining the overall braking system performance.

[0047] In one possible implementation, the communication path between the primary equalizing air cylinder and the backup equalizing air cylinder is blocked, so that the decompression rate of the backup equalizing air cylinder during initial braking does not exceed the decompression rate of the backup equalizing air cylinder during normal braking by 10 kPa / s-40 kPa / s, so that the locomotive will not cause emergency braking.

[0048] In the above scheme, by controlling the decompression rate, the smoothness and safety of the braking process are ensured, and the risk of unstable braking or emergency braking caused by excessively rapid decompression is avoided.

[0049] When the air backup braking system is engaged, by manipulating the backup brake valve to the initial braking position, the air passages of the backup equalizing air cylinder and the initial braking air cylinder can be connected. After the air passages are connected, since the initial air pressure of the initial braking air cylinder is zero, the backup equalizing air cylinder charges the initial braking air cylinder with air until balance is reached, achieving a pressure reduction of 50 kPa in the backup equalizing air cylinder. The volumes of the initial braking air cylinder 102 and the backup equalizing air cylinder 104 are related, and the pressure reduction can be calculated using the gas state equation. Assuming the backup equalizing air cylinder is V1 and the brake set pressure is 600 kPa, then the initial braking air cylinder V2 = 1 / 11 * V1. After the backup equalizing air cylinder accurately reduces the pressure, the relay valve 105 achieves precise control of the train pipe pressure based on the backup equalizing air cylinder pressure, ultimately achieving precise control of the initial braking pressure.

[0050] Meanwhile, the backup brake valve 103 has three positions, starting from the release position: initial braking position, neutral position, and braking position. When the driver and passengers begin initial braking and decompression, simply placing the backup brake valve handle in the initial braking position completes the initial braking and decompression. After decompression, it automatically maintains pressure and will not continue to decompress. When the driver and passengers wish to continue decompression, they can move the backup brake valve handle from the initial braking position through the neutral position to the braking position. At this time, the communication path between the backup equalizing air cylinder and the initial braking air cylinder is closed, and the backup equalizing air cylinder continues to decompress at the normal rate through the backup brake valve. The amount of decompression is determined based on time, while the initial braking air cylinder is in a pressure-maintaining state. When the desired decompression value is reached, the driver and passengers can move the backup brake valve handle from the braking position to the neutral position. At this time, all air passages are closed, and the system is in a pressure-maintaining state, realizing the pressure-maintaining function of the train pipe. When release is needed after braking, the backup brake valve handle is moved back to the release position. At this time, the total air pressure after adjustment is supplied to the backup equalizing air cylinder through the backup brake valve, while the initial braking air cylinder is discharged to the atmosphere, preparing for the next initial braking. When the backup brake valve is in the initial braking position, the initial braking function can be achieved without the need for the operator to control it by adjusting the ventilation time.

[0051] This air backup braking system can accurately achieve initial braking pressure reduction, which facilitates the speed adjustment of the entire train in air backup mode, improves the availability of the air backup braking system, and reduces the operational difficulty for drivers and passengers.

[0052] See Figure 2 This is a schematic diagram of the air circuit connection of an air backup braking system according to another embodiment; it also includes: a switching valve 106; wherein, the C1 end and C2 end of the switching valve 106 are respectively connected to the output end of the backup pressure regulating valve 101 and the output end of the equalizing air cylinder 104, and the switching valve 106 has an A1 port and an A2 port; the switching valve 106 is configured such that: when the pressure at the C1 end is 55 kPa or more greater than the pressure at the C2 end, the A1 port and the A2 port of the switching valve 106 are cut off, otherwise, the A1 and A2 ports are connected; wherein, the A1 port of the switching valve 106 is connected to the initial air cylinder 102, and the A2 port is connected to the A1 port of the backup braking valve (103).

[0053] In another embodiment, it also includes a potentiometer 107 and a pressure valve 108. The C1 and C2 terminals of the pressure valve 108 are respectively connected to the output terminals of the backup pressure regulating valve 101 and the output terminal of the equalizing cylinder 104. The pressure valve 108 is configured to output a linear displacement based on the comparison result between the pressure output by the backup pressure regulating valve 101 and the pressure value of the equalizing cylinder 104. This linear displacement corresponds to the electrical signal of the potentiometer 107.

[0054] The backup brake valve 103 outputs electrical signals corresponding to four positions a, b, c, and d. The switching valve 106 cuts off / closes or connects the primary brake cylinder 102 and the equalizing cylinder 104 based on the comparison between the output pressure of the backup pressure regulating valve 101 and the pressure of the equalizing cylinder 104. When the pressure difference between the C1 end and the C2 end of the switching valve 106 exceeds (greater than or equal to) 55 kPa, the switching valve 106 closes the passage between A1 and A2. When the pressure difference between C1 and C2 is less than 55 kPa, the passage between A1 and A2 will be connected.

[0055] Pressure valve 108 is used to compare the pressure difference, that is, the pressure adjusted by backup pressure regulating valve 101 and the pressure value of equalizing air cylinder 104, and outputs linear displacement based on the pressure difference between the two to control the output value of potentiometer 107.

[0056] Potentiometer 107 is used to acquire the displacement value of pressure valve 108 and output an electrical signal that changes with the position of pressure valve 108.

[0057] The switching valve 106 in the system further assists in controlling the initial braking pressure reduction. When the pressure reduction exceeds the initial braking pressure of 50 kPa, the connection passage will be closed to ensure that the initial braking pressure reduction does not exceed the standard.

[0058] In the above embodiment, while operating the backup brake valve 103, the system can collect four position electrical signals of the backup brake valve 103 to identify the state of the backup brake valve 103. At the same time, the pressure valve 108 set by the system can output a displacement from zero to a certain value according to the difference between the output pressure of the pressure regulating valve 101 and the pressure of the equalizing air cylinder 104. This displacement is used to control the output signal position of the potentiometer 107. The system will collect the output signal value of the potentiometer 107 and display the value of the equalizing air cylinder pressure reduction in real time through electrical signals to determine whether the initial braking pressure reduction or the normal braking pressure reduction meets the requirements.

[0059] The system utilizes a pressure valve 108, potentiometer 107, and related acquisition circuits to determine the minimum and maximum pressure reduction amounts based on the current values ​​at the initial and maximum pressure reduction positions. Finally, the system displays the pressure reduction value in real time based on the current signal. This system can detect and display the pressure reduction value of the equalizing air cylinder in real time, allowing drivers and passengers to determine whether the pressure reduction meets requirements. It offers greater flexibility and practicality.

[0060] As an alternative implementation, the initial air cylinder and the backup equalizing air cylinder in this scheme communicate with each other in the initial braking position, or they can be controlled by an external switching valve.

[0061] According to one aspect of this application, a locomotive is provided that includes an air backup braking system according to any of the above embodiments.

[0062] In the above scheme, the entire backup braking system is integrated into the locomotive, which can be a high-speed train, a bullet train, a subway, or other rail vehicle. This ensures the overall performance and high efficiency of the system, while also facilitating system maintenance and operation. It also achieves precise control of the backup equalization cylinder pressure at 50 kPa during the initial braking decompression in the air backup braking mode, improving the availability of the air backup braking system and making it easier for drivers and passengers to operate accurately.

[0063] Finally, it should be noted that the various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

[0064] The above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them; although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications can still be made to the specific implementation of the present invention or equivalent substitutions can be made to some technical features without departing from the spirit of the technical solutions of the present invention, and all such modifications and substitutions should be covered within the scope of the technical solutions claimed in the present invention.

Claims

1. An air backup braking system, characterized in that, include: The system includes a backup pressure regulating valve (101), a primary air cylinder (102), a backup brake valve (103), a backup equalizing air cylinder (104), and a backup relay valve (105). The main air supply is connected through the backup pressure regulating valve (101), the backup brake valve (103), the backup equalizing air cylinder (104), and the backup relay valve (105). The main air supply of the relay valve is connected to the train pipe through the backup relay valve (105). The backup relay valve outputs the train pipe pressure according to the pressure change of the backup equalizing air cylinder. Among them, the backup brake valve (103) has a release position, an initial braking position, a neutral position and a braking position, and the backup brake valve (103) has ports A1, A2, A3, A4, A5 and A6; When the air is in the relief position, port A1 communicates with port A4 to connect the primary air cylinder (102) to the atmosphere; port A3 communicates with port A6 to connect the main air and the equalizing air cylinder (104); port A2 and port A5 are cut off. During the initial processing stage, ports A1 and A5 communicate to connect the initial processing air cylinder (102) and the backup equalizing air cylinder; ports A2, A3, A4 and A6 are disconnected. In the neutral position, all airways are cut off; When in the braking position, ports A2 and A6 communicate, while ports A1, A3, A4 and A5 are disconnected, thus opening the passage between the backup equalizing air cylinder and the atmosphere. When the backup brake valve (103) is in the initial position, the initial air cylinder (102) is connected to the backup equalizing air cylinder (104), the backup equalizing air cylinder (104) charges the initial air cylinder (102) with air, and the backup equalizing air cylinder (104) reduces the pressure by 50 kPa. The volume relationship between the primary air cylinder (102) and the backup equalizing air cylinder (104) is calculated by the gas state equation; the volume of the backup equalizing air cylinder (104) is V1, and the brake constant pressure is 600kPa, then the volume of the primary air cylinder (102) is V2 = (1 / 11) * V1.

2. The air backup braking system according to claim 1, characterized in that, Also includes: Switching valve (106); The switching valve (106) has C1 and C2 terminals connected to the output terminals of the backup pressure regulating valve (101) and the equalizing air cylinder (104), respectively. The switching valve (106) has A1 port and A2 port. The switching valve (106) is configured such that when the pressure at C1 terminal is 55 kPa or more greater than the pressure at C2 terminal, the A1 port and A2 port of the switching valve (106) are cut off; otherwise, the A1 and A2 ports are connected. Among them, the A1 port of the switching valve (106) is connected to the primary air cylinder (102), and the A2 port is connected to the A1 port of the backup brake valve (103).

3. The air backup braking system according to claim 2, characterized in that, Also includes: A potentiometer (107) and a pressure valve (108) are provided. The C1 and C2 terminals of the pressure valve (108) are connected to the output terminals of the backup pressure regulating valve (101) and the equalizing air cylinder (104), respectively. The pressure valve (108) is configured to output a linear displacement based on the comparison between the pressure output by the backup pressure regulating valve (101) and the pressure value of the equalizing air cylinder (104). This linear displacement corresponds to the electrical signal of the potentiometer (107).

4. The air backup braking system according to claim 3, characterized in that, Also includes: The volume relationship between the primary air cylinder (102) and the backup equalizing air cylinder (104) is calculated using the gas state equation, so that the pressure reduction of the backup equalizing air cylinder (104) is 50 kPa.

5. The air backup braking system according to claim 3, characterized in that, The communication path between the primary equalizing air cylinder (102) and the backup equalizing air cylinder (104) is blocked so that the decompression rate of the backup equalizing air cylinder (104) during initial braking does not exceed the decompression rate of the regular braking equalizing air cylinder (10kPa / s-40kPa / s), so that the locomotive will not cause emergency braking.

6. A locomotive, characterized in that, An air backup braking system comprising any one of claims 1-5.

Images