Mounting method of friction plate temperature measuring sensor, braking system and railway vehicle

Abstract

The invention provides an installation method of a friction plate temperature measurement sensor, a braking system and a railway vehicle. The mounting method comprises the following steps: processing a temperature measuring hole which is arranged at an interval with a friction part of the friction plate on the friction plate; a temperature measuring sensor is arranged in the temperature measuring hole; and the peripheral side of the temperature measuring sensor is wrapped with a filling medium, so that the temperature measuring sensor is fixed in the temperature measuring hole, the temperature of the friction part is transmitted to the temperature measuring sensor through the filling medium, the part, located in the temperature measuring hole, of the filling medium is rigid, and the part, located outside the temperature measuring hole, of the filling medium is flexible.

Description

Technical Field

[0001] The present disclosure relates to the technical field of vehicle brake temperature testing, and more specifically, to an installation method of a friction plate temperature sensor, a brake system and a rail vehicle. Background Art

[0002] Friction plates can be components that achieve energy conversion by contacting other surfaces and generating friction. For example, friction plates can be brake shoes, brake pads, drive belts, wheel discs, bearings, gears, brake discs, and brake drums. When friction plates are rotating or moving at high speed, such as when the brake shoes and wheel treads of rail vehicles are braked, a lot of heat will be generated. This heat is transferred between the friction parts through conduction, radiation, and convection, causing the temperature of the components to rise sharply. The temperature changes of these components have a significant impact on their mechanical and chemical properties. High temperatures may cause surface powdering, flaking, and fluctuations in the coefficient of friction. Therefore, it is very important to monitor the temperature changes of the friction parts in real time.

[0003] However, since the friction part is in a friction contact state, it is impossible to use a temperature sensor to directly contact and measure the friction part. Usually, a temperature measuring hole is opened at a position of the friction plate that is separated from the friction part, and a temperature measuring sensor is installed in the temperature measuring hole to indirectly measure the temperature of the friction part. However, the existing installation method of the temperature measuring sensor has the disadvantage of low measurement accuracy. Summary of the invention

[0004] In view of this, the present disclosure provides a method for installing a friction plate temperature sensor, a braking system and a rail vehicle.

[0005] One aspect of the present disclosure provides a method for installing a friction plate temperature sensor, comprising: machining a temperature measuring hole on the friction plate that is spaced apart from a friction portion of the friction plate; arranging the temperature sensor in the temperature measuring hole; and wrapping a filling medium around the temperature sensor to fix the temperature sensor in the temperature measuring hole, and transferring the temperature of the friction portion to the temperature sensor through the filling medium, wherein a portion of the filling medium located in the temperature measuring hole is rigid, and a portion of the filling medium located outside the temperature measuring hole is flexible.

[0006] Optionally, the filling medium includes: a flexible layer, a rigid layer and a thermally conductive layer; the filling medium is wrapped around the temperature sensor, including: the thermally conductive layer is filled between the temperature measuring end of the temperature sensor and the temperature measuring hole; the rigid layer is filled between the middle part of the temperature sensor close to the temperature measuring end and the temperature measuring hole; the flexible layer is wrapped around the part of the temperature sensor extending out of the temperature measuring hole.

[0007] Optionally, filling the rigid layer between the middle portion of the temperature sensor close to the temperature measuring end and the temperature measuring hole comprises: filling a fluid material between the middle portion of the temperature sensor close to the temperature measuring end and the temperature measuring hole; and heating the fluid material to solidify it to obtain the rigid layer.

[0008] Another aspect of the present disclosure provides a braking system, comprising: a friction plate, formed with a temperature measuring hole, the temperature measuring hole being spaced apart from a friction portion of the friction plate; a temperature measuring sensor, disposed in the temperature measuring hole and extending out of the temperature measuring hole; and a filling medium, wrapping the temperature measuring sensor in an extending direction of the temperature measuring hole to fix the temperature measuring sensor in the temperature measuring hole and transfer the temperature of the friction portion to the temperature measuring sensor, wherein a portion of the filling medium located in the temperature measuring hole is rigid, and a portion of the filling medium located outside the temperature measuring hole is flexible.

[0009] Optionally, the filling medium includes: a flexible layer, a rigid layer and a thermal conductive layer; the portion of the temperature sensor extending out of the temperature measuring hole is wrapped with the flexible layer, the portion between the temperature sensor and the temperature measuring hole close to the flexible layer is filled with the rigid layer, and the portion between the temperature sensor and the temperature measuring hole away from the flexible layer is filled with the thermal conductive layer, and the temperature of the friction part is transferred to the temperature measuring end of the temperature sensor through the thermal conductive layer.

[0010] Optionally, the flexible layer covers a portion of the rigid layer.

[0011] Optionally, the heat conductive layer has fluidity.

[0012] Optionally, the rigid layer is formed by heating and curing a fluid material.

[0013] Optionally, the flexible layer covers the opening of the temperature measuring hole.

[0014] Another aspect of the present disclosure provides a rail vehicle, comprising: a vehicle body; wheels; and the above-described braking system, which is installed on the vehicle body and utilizes the friction plates of the braking system to apply braking force to the treads of the wheels to brake the rail vehicle.

[0015] According to the embodiment of the present disclosure, by wrapping the filling medium around the temperature sensor, the filling medium can transfer the temperature of the friction part to the temperature sensor, avoiding the temperature being transferred to the temperature sensor by air, thereby improving the detection accuracy. Furthermore, since the filling medium located in the temperature measuring hole is rigid and the filling medium located outside the temperature measuring hole is flexible, the surrounding side of the temperature measuring sensor can be made into a structure that is tough outside and hard inside, which can effectively resist external vibration, impact and drag, and the temperature sensor can be installed in the temperature measuring hole more stably, thereby further improving the detection accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The above and other objects, features and advantages of the present disclosure will become more apparent through the following description of the embodiments of the present disclosure with reference to the accompanying drawings, in which:

[0017] Figure 1 The cross-sectional view schematically shows a temperature sensor installed on a friction plate according to the installation method in the prior art.

[0018] Figure 2 A cross-sectional view schematically shows a temperature sensor according to an embodiment of the present disclosure installed on a friction plate.

[0019] Figure 3 A side view of a friction plate according to an embodiment of the present disclosure is schematically shown.

[0020] Figure 4 A cross-sectional view of a friction plate according to an embodiment of the present disclosure is schematically shown.

[0021] Reference numerals

[0022] 1. Friction plate; 2. Temperature sensor; 21. Temperature measuring end; 3. Temperature measuring hole; 4. Filling medium; 41. Heat conducting layer; 42. Rigid layer; 43. Flexible layer. DETAILED DESCRIPTION

[0023] Hereinafter, embodiments of the present disclosure will be described with reference to the accompanying drawings. However, it should be understood that these descriptions are exemplary only and are not intended to limit the scope of the present disclosure. In the following detailed description, for ease of explanation, many specific details are set forth to provide a comprehensive understanding of the embodiments of the present disclosure. However, it is apparent that one or more embodiments may also be implemented without these specific details. In addition, in the following description, descriptions of known structures and technologies are omitted to avoid unnecessary confusion of the concepts of the present disclosure.

[0024] The terms used herein are only for describing specific embodiments and are not intended to limit the present disclosure. The terms "comprise", "include", etc. used herein indicate the existence of the features, steps, operations and / or components, but do not exclude the existence or addition of one or more other features, steps, operations or components.

[0025] All terms (including technical and scientific terms) used herein have the meanings commonly understood by those skilled in the art unless otherwise defined. It should be noted that the terms used herein should be interpreted as having a meaning consistent with the context of this specification and should not be interpreted in an idealized or overly rigid manner.

[0026] When using expressions such as "at least one of A, B, and C, etc.", they should generally be interpreted according to the meaning of the expression commonly understood by those skilled in the art (for example, "a system having at least one of A, B, and C" should include but is not limited to a system having A alone, B alone, C alone, A and B, A and C, B and C, and / or A, B, C, etc.).

[0027] Figure 1 The cross-sectional view schematically shows a temperature sensor installed on a friction plate according to the installation method in the prior art.

[0028] like Figure 1 As shown, in the process of realizing the concept of the present disclosure, the inventor found that in the installation method of the prior art, in order to facilitate the installation of the temperature sensor 2 in the temperature measuring hole 3, the temperature sensor 2 and the temperature measuring hole 3 are both clearance fit. At this time, the temperature measuring end 21 of the temperature measuring sensor 2 will be suspended in the temperature measuring hole 3, and due to the low thermal conductivity and poor thermal conductivity of the air, the temperature measuring end 21 cannot accurately capture the temperature of the friction part.

[0029] Figure 2 A cross-sectional view schematically shows a temperature sensor installed on a friction plate according to an installation method of an embodiment of the present disclosure. Figure 3 A side view of a friction plate according to an embodiment of the present disclosure is schematically shown. Figure 4 A cross-sectional view of a friction plate according to an embodiment of the present disclosure is schematically shown.

[0030] like Figure 2-Figure 4 As shown, the present disclosure provides a method for installing a friction plate temperature sensor. The installation method includes the following steps S110 to S130.

[0031] In step S110 , a temperature measuring hole 3 is machined on the friction plate 1 and is spaced apart from the friction portion of the friction plate 1 .

[0032] According to embodiments of the present disclosure, components such as a laser, a stamping machine, and a drill bit can be used to process a temperature measurement hole 3 on the friction plate 1. The distance between the temperature measurement hole 3 and the friction part can be determined according to the material characteristics of the friction plate 1 and the state of the friction part. For example, the distance between the temperature measurement hole 3 and the friction part can be determined according to the distribution and depth of cracks in the friction part. In order to measure the temperature of the friction part more accurately, on the premise of ensuring that the friction plate 1 and the temperature measurement hole 3 are not worn out, the temperature measurement hole 3 can be set as close as possible to the friction part. For example, the distance between the temperature measurement hole 3 and the friction part can be within 1 mm - 4 mm.

[0033] Furthermore, the depth of the temperature measurement hole 3 can be determined according to the contact state of the friction plate 1 with other surfaces, so as to ensure that the orthographic projection of the temperature measurement end 21 falls within the orthographic projection range of the friction part. The orthographic projection direction can be Figure 2 the vertical direction shown. The diameter of the temperature measurement hole 3 can be set according to the cross-sectional dimension of the temperature measurement sensor 2. For example, the diameter of the temperature measurement hole 3 can be 0.5 mm - 2 mm larger than the maximum cross-sectional dimension of the temperature measurement sensor 2.

[0034] In step S120, the temperature measurement sensor 2 is disposed in the temperature measurement hole 3.

[0035] According to embodiments of the present disclosure, after the temperature measurement sensor 2 is disposed in the temperature measurement hole 3, the temperature measurement end 21 of the temperature measurement sensor 2 will be suspended in the temperature measurement hole 3.

[0036] In step S130, a filling medium 4 is wrapped around the periphery of the temperature measurement sensor 2 to fix the temperature measurement sensor 2 in the temperature measurement hole 3 and enable the temperature of the friction part to be transmitted to the temperature measurement sensor 2 through the filling medium 4.

[0037] According to embodiments of the present disclosure, the part of the filling medium 4 located inside the temperature measurement hole 3 can be rigid, and the part of the filling medium 4 located outside the temperature measurement hole 3 can be flexible.

[0038] According to embodiments of the present disclosure, by wrapping the filling medium 4 around the periphery of the temperature measurement sensor 2, the filling medium 4 can transmit the temperature of the friction part to the temperature measurement sensor 2, avoiding transmission to the temperature measurement sensor 2 by air, thereby improving the detection accuracy. Further, since the filling medium 4 located inside the temperature measurement hole 3 is rigid and the filling medium 4 located outside the temperature measurement hole 3 is flexible, the periphery of the temperature measurement sensor 2 can have a structure with an outer toughness and an inner rigidity, which can effectively resist external vibration, impact, and dragging effects, and can install the temperature measurement sensor 2 in the temperature measurement hole 3 more stably, thereby further improving the detection accuracy.

[0039] In some embodiments, the filling medium 4 can include: a flexible layer 43, a rigid layer 42, and a heat-conducting layer 41. Step S130 includes the following steps S131 - S133.

[0040] In step S131 , a heat-conducting layer 41 is filled between the temperature measuring end 21 of the temperature measuring sensor 2 and the temperature measuring hole 3 .

[0041] According to the embodiment of the present disclosure, the heat-conducting layer 41 can be made of a heat-conducting material with high thermal conductivity, good fluidity and filling properties. The heat-conducting layer 41 can be tightly filled between the temperature measuring hole 3 and the temperature measuring end 21, so that the temperature of the friction part is transferred to the temperature measuring sensor 2 through the heat-conducting layer 41, rather than being transferred to the temperature measuring sensor 2 by air, which can quickly respond to temperature changes, thereby improving detection accuracy.

[0042] In step S132 , a rigid layer 42 is filled between the middle portion of the temperature measuring sensor 2 close to the temperature measuring end 21 and the temperature measuring hole 3 .

[0043] According to the embodiment of the present disclosure, since the heat-conducting layer 41 with better heat-conducting performance is generally fluid, it is not possible to fix the temperature sensor 2 well. By providing the rigid layer 42, the temperature sensor 2 can be firmly fixed in the temperature measuring hole 3.

[0044] In step S133 , the portion of the temperature measuring sensor 2 extending out of the temperature measuring hole 3 is wrapped with a flexible layer 43 .

[0045] According to the embodiment of the present disclosure, since the rigid layer 42 has high hardness and strength, it is easy to break under external vibration, impact and dragging. By providing the flexible layer 43, the surrounding side of the temperature sensor 2 can be made into a structure that is tough on the outside and rigid on the inside, which can effectively resist external vibration, impact and dragging, so that the temperature sensor 2 can be more stably installed in the temperature measuring hole 3, further improving the detection accuracy.

[0046] In some embodiments, step S132 may include: filling a fluid material between the middle portion of the temperature sensor 2 close to the temperature measuring end 21 and the temperature measuring hole 3 , and heating the fluid material to solidify it to obtain a rigid layer 42 .

[0047] According to the embodiment of the present disclosure, by filling the fluid material between the middle part near the temperature measuring end 21 and the temperature measuring hole 3, the fluid material can be better filled between the temperature measuring sensor 2 and the temperature measuring hole 3 to avoid the "gap" between the temperature measuring sensor 2 and the temperature measuring hole 3, and because the fluid material can be solidified, after the fluid material is solidified, the temperature sensor 2 can be firmly fixed in the temperature measuring hole 3. The fluid material can include various high-temperature rubber powders. After the high-temperature rubber powder is mixed with its specific curing liquid, it can undergo a chemical reaction and solidify into a shape.

[0048] In some embodiments, the flexible layer 43 may cover part of the rigid layer 42. Furthermore, the rigid layer 42 may also be wrapped on the portion of the temperature sensor 2 extending out of the temperature measuring hole 3, that is, the rigid layer 42 may extend from the inside of the temperature measuring hole 3 to the outside of the temperature measuring hole 3. The portion of the rigid layer 42 extending out of the temperature measuring hole 3 may be covered by the flexible layer 43, thereby avoiding "tearing" between the rigid layer 42 and the flexible layer 43, effectively resisting external vibration, impact and dragging, and thus the temperature sensor 2 may be more stably installed in the temperature measuring hole 3.

[0049] The present disclosure also provides a braking system. The braking system may include the friction plate 1, the temperature sensor 2 and the filling medium 4 described above. Figure 1-Figure 3 As shown, the friction plate 1 may be formed with a temperature measuring hole 3. The temperature measuring hole 3 is spaced apart from the friction part of the friction plate 1. The temperature sensor 2 may be installed in the temperature measuring hole 3 of the friction plate 1 by the above-mentioned installation method. The temperature sensor 2 may be arranged in the temperature measuring hole 3 and extend out of the temperature measuring hole 3. The temperature sensor 2 may be any one of a thermocouple sensor, a resistance temperature detector, an armored temperature sensor with a metal sheath, and a thermocouple temperature measuring wire without protective measures. Preferably, the temperature sensor 2 is a thermocouple temperature measuring wire, which has the advantages of small thermal resistance, fast response, large temperature measuring range, and high cost performance. Furthermore, the temperature measuring end 21 of the thermocouple temperature measuring wire is the end welding point of two couple wires.

[0050] Furthermore, the filling medium 4 can wrap the temperature sensor 2 in the extension direction of the temperature measuring hole 3 to fix the temperature sensor 2 in the temperature measuring hole 3 and transfer the temperature of the friction part to the temperature sensor 2. The portion of the filling medium 4 located in the temperature measuring hole 3 is rigid, and the portion of the filling medium 4 located outside the temperature measuring hole 3 is flexible.

[0051] According to the embodiment of the present disclosure, by wrapping the filling medium 4 around the temperature sensor 2, the temperature of the friction part is transferred to the temperature sensor 2 through the filling medium 4, which can avoid being transferred to the temperature sensor 2 by air, and can improve the detection accuracy. Furthermore, since the part of the filling medium 4 located in the temperature measuring hole 3 is rigid, and the part located outside the temperature measuring hole 3 is flexible, the surrounding side of the temperature sensor 2 can be made into a structure that is tough outside and hard inside, which can effectively resist external vibration, impact and drag, so that the temperature sensor 2 can be installed in the temperature measuring hole 3 more stably, and the detection accuracy can be further improved, so that the temperature of the friction plate 1 can be better monitored, and the stability of the operation of the brake system can be guaranteed.

[0052] In some embodiments, the portion of the temperature sensor 2 extending out of the temperature measuring hole 3 is wrapped with a flexible layer 43 .

[0053] According to an embodiment of the present disclosure, the flexible layer 43 may be made of a flexible material. For example, the material of the flexible layer 43 may include at least one of the following: fluorosilicone rubber, phenyl silicone rubber, methyl vinyl silicone rubber, silicon nitrogen rubber or silicon phosphorus rubber.

[0054] In some embodiments, the flexible layer 43 may cover the opening of the temperature measuring hole 3 to seal the temperature measuring hole 3 , thereby improving the stability of the installation of the temperature measuring sensor 2 .

[0055] According to the embodiment of the present disclosure, the flexible layer 43 can be made of a flexible material with waterproof performance, such as various types of high temperature resistant silicone rubber, which can play a good waterproof, oil-proof, anti-fouling and sealing role, thereby ensuring the stability and reliability of the temperature sensor 2.

[0056] In some embodiments, the portion between the temperature measuring sensor 2 and the temperature measuring hole 3 close to the flexible layer 43 is filled with a rigid layer 42 .

[0057] According to the embodiment of the present disclosure, the rigid layer 42 can be formed by heating a fluid material. Before heating, the rigid layer 42 can have fluidity to better fill between the temperature measuring hole 3 and the temperature measuring sensor 2, and avoid a gap between the temperature measuring hole 3 and the temperature measuring sensor 2. After heating, the rigid layer 42 can be rigid, so that the temperature measuring sensor 2 can be stably installed in the temperature measuring hole 3.

[0058] According to the embodiment of the present disclosure, the material of the rigid layer 42 may include at least one of the following: silicate rubber powder, silicone rubber powder, ceramic rubber powder, epoxy resin rubber powder or rubber rubber powder.

[0059] In some embodiments, the portion between the temperature sensor 2 and the temperature measuring hole 3 away from the flexible layer 43 is filled with a heat conductive layer 41. The temperature of the friction part is transferred to the temperature measuring end 21 of the temperature sensor 2 through the heat conductive layer 41, rather than being transferred to the temperature sensor 2 by air, which can quickly respond to temperature changes, thereby improving detection accuracy.

[0060] According to the embodiment of the present disclosure, the heat-conducting layer 41 can be made of a heat-conducting material with high thermal conductivity, good fluidity and filling properties. Since the heat-conducting layer 41 has fluidity, it can be better filled between the temperature measuring hole 3 and the temperature measuring sensor 2.

[0061] According to an embodiment of the present disclosure, the material of the heat-conducting layer 41 may include at least one of the following: thermally conductive silicone grease, copper powder, aluminum powder or boron nitride powder.

[0062] According to the embodiment of the present disclosure, by providing a rigid layer 42 and a flexible layer 43, the peripheral side of the temperature sensor 2 can be made to have a structure that is tough on the outside and rigid on the inside, which can effectively resist external vibration, impact and dragging, so that the temperature sensor 2 can be more stably installed in the temperature measuring hole 3, and the detection accuracy can be further improved, so that the temperature of the friction plate 1 can be monitored more accurately, thereby ensuring the stability of the operation of the braking system.

[0063] The present disclosure also provides a rail vehicle. The rail vehicle may be a high-speed train, or a normal train, etc. The rail vehicle may include a vehicle body, wheels, and the above-described braking system. The braking system may be installed on the vehicle body. The friction plate 1 of the braking system may be used to apply a braking force to the tread of the wheel to brake the rail vehicle. Since the temperature of the friction plate 1 may be monitored more accurately, the stability of the braking system operation may be ensured, thereby improving the safety of the rail vehicle.

[0064] It will be appreciated by those skilled in the art that the features described in the various embodiments of the present disclosure may be combined and / or combined in a variety of ways, even if such combinations or combinations are not explicitly described in the present disclosure. In particular, without departing from the spirit and teachings of the present disclosure, the features described in the various embodiments of the present disclosure may be combined and / or combined in a variety of ways. All of these combinations and / or combinations fall within the scope of the present disclosure.

[0065] The embodiments of the present disclosure are described above. However, these embodiments are only for illustrative purposes and are not intended to limit the scope of the present disclosure. Although the embodiments are described above, this does not mean that the measures in the various embodiments cannot be used in combination to advantage. Without departing from the scope of the present disclosure, those skilled in the art may make a variety of substitutions and modifications, which should all fall within the scope of the present disclosure.

Claims

1. A method for installing a friction plate temperature sensor, characterized in that: include: On the friction plate, a temperature measuring hole is machined and arranged at a distance from the friction part of the friction plate; The temperature measuring sensor is arranged in the temperature measuring hole; as well as A filling medium is wrapped around the temperature sensor to fix the temperature sensor in the temperature measuring hole, and the temperature of the friction part is transferred to the temperature sensor through the filling medium, wherein a portion of the filling medium located in the temperature measuring hole is rigid, and a portion of the filling medium located outside the temperature measuring hole is flexible.

2. The method for installing a friction plate temperature sensor according to claim 1, characterized in that: The filling medium includes: a flexible layer, a rigid layer and a heat-conducting layer; the filling medium is wrapped around the temperature sensor, including: Filling the heat-conducting layer between the temperature measuring end of the temperature measuring sensor and the temperature measuring hole; Filling the rigid layer between the middle portion of the temperature measuring sensor close to the temperature measuring end and the temperature measuring hole; and The flexible layer is wrapped around a portion of the temperature measuring sensor extending out of the temperature measuring hole.

3. The method for installing a friction plate temperature sensor according to claim 2, characterized in that: The rigid layer is filled between the middle portion of the temperature measuring sensor close to the temperature measuring end and the temperature measuring hole, comprising: Filling a fluid material between the middle portion of the temperature measuring sensor close to the temperature measuring end and the temperature measuring hole; and The fluid material is heated to solidify it, thereby obtaining the rigid layer.

4. A braking system, characterized in that: include: The friction plate is formed with a temperature measuring hole, wherein the temperature measuring hole is spaced apart from the friction part of the friction plate; A temperature measuring sensor is disposed in the temperature measuring hole and extends out of the temperature measuring hole; as well as A filling medium wraps the temperature measuring sensor in the extension direction of the temperature measuring hole to fix the temperature measuring sensor in the temperature measuring hole and transfer the temperature of the friction part to the temperature measuring sensor, wherein a portion of the filling medium located in the temperature measuring hole is rigid, and a portion of the filling medium located outside the temperature measuring hole is flexible.

5. The braking system according to claim 4, characterized in that: The filling medium includes: a flexible layer, a rigid layer and a heat-conducting layer; the portion of the temperature sensor extending out of the temperature measuring hole is wrapped with the flexible layer, the portion between the temperature sensor and the temperature measuring hole close to the flexible layer is filled with the rigid layer, and the portion between the temperature sensor and the temperature measuring hole away from the flexible layer is filled with the heat-conducting layer, and the temperature of the friction part is transferred to the temperature measuring end of the temperature sensor through the heat-conducting layer.

6. The braking system according to claim 5, characterized in that: The flexible layer covers a portion of the rigid layer.

7. The braking system according to claim 5, characterized in that: The heat conductive layer has fluidity.

8. The braking system according to claim 5, characterized in that: The rigid layer is formed by heating and solidifying the fluid material.

9. The braking system according to claim 5, characterized in that: The flexible layer covers the opening of the temperature measuring hole.

10. A rail vehicle, characterized in that: include: Vehicle body; wheel; as well as The braking system as described in any one of claims 4 to 9 is installed on the vehicle body, and the friction plates of the braking system are used to apply braking force to the treads of the wheels to brake the rail vehicle.

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