Train braking apparatus and train braking method

ES 2 396 491 T3

DESCRIPTION

Train braking apparatus and train braking method

TECHNICAL FIELD

[0001] The present invention relates to a train braking device and a train braking method.

PREVIOUS TECHNIQUE

[0002] A train braking device having an air brake controller is configured in such a way that a pressure control signal is generated based on a brake command and a travel speed of a train, a relay valve outputs a brake cylinder pressure corresponding to the pressure control signal, and the brake cylinder pressure acts on the brake shoes in order to obtain a predetermined braking force. The braking force is calculated by a product of the brake cylinder pressure and a friction coefficient of the brake shoe. Furthermore, the coefficient of friction changes in a region where the speed of travel of a train is low and it also changes as a function of a period of use of the brake shoe. To obtain a stable braking force, a train braking device is required that can control the pressure of the brake cylinder appropriately according to the change in the friction coefficient.

[0003] In the Patent Document 1 mentioned below a train braking device is described which is configured to calculate a coefficient of friction for each brake notch and then calculate a braking force. Furthermore, a brake force is calculated in accordance with a change in the friction coefficient at low speed by using a predetermined friction coefficient pattern.

[0004] Patent Document 1: Japanese Public Patent Application No. H11-235972.

[0005] The prior art is described in JP 2000 211487A1.

DESCRIPTION OF THE INVENTION

PROBLEM TO SOLVE BY THE INVENTION

[0006] As for the train braking device described in Patent Document 1, as the friction coefficient changes for each brake notch, there is a problem that its deceleration varies greatly. Because a change in the brake shoes due to aging deterioration is not taken into account, when the times for the replacement of the brake shoes are different from each other, the friction coefficients of the brake shoes are different by some from others and therefore a stable braking force cannot be obtained.

[0007] The present invention has been achieved in view of the above problems, and an object of the present invention is to provide a train braking device and a train braking method for stabilizing deceleration.

MEANS TO SOLVE THE PROBLEM

[0008] In order to solve the aforementioned problems, a train braking device is constructed to control a brake cylinder pressure based on an initial brake speed and a brake command according to one aspect of the present invention, such that it includes: an air brake controller that stores therein a plurality of friction coefficients corresponding to the initial brake speed and the brake command and generates a pressure control signal based on the friction coefficients corresponding to the initial speed brake and brake command, an electro-pneumatic conversion valve, which converts the pressure from the control signal into a pneumatic signal, and a relay valve that generates the pressure of the brake cylinder corresponding to the pneumatic signal.

EFFECT OF THE INVENTION

[0009] According to the present invention, the deceleration can be stabilized.

BRIEF DESCRIPTION OF THE DRAWINGS

[0010]

[FIG. 1] FIG. 1 is an example of a configuration of a train braking device according to a first embodiment.

ES 2 396 491 T3

[FIG.2] FIG. 2 is a block diagram of the functions of an air brake controller.

[FIG. 3] FIG. 3 is an example of a friction coefficient setting table.

[FIG. 4] FIG. 4 is an example of a friction coefficient pattern.

[FIG. 5] FIG. 5 is a flow chart of an example of a flow for determining a pressure in the brake cylinder using a friction coefficient setting table.

[FIG. 6] FIG. 6 is a flow chart of an example of a flow for determining a pressure in the brake cylinder using a pattern of friction coefficients.

LETTER OR NUMBER EXPLANATIONS

[0011]

1, 1 a, 1 b, 1 c, 1 d Speed ​​sensor

Brake command unit

Air brake controller

3rd speed input unit

3b Calculation unit for coefficient of friction

3c Brake force calculation unit

3d output unit

Electropneumatic shift valve

Relay valve

Pressure sensor

Brake cylinder

Brake shoe

Wheel

Train braking device

Air tank

Friction coefficient setting table

Brake notch

Initial brake speed

Coefficient of friction

1D speed signal

2D Brake command

3D Pressure control signal

5D Brake cylinder pressure

ES 2 396 491 T3

<td>6D</td><td>Feedback order</td>

<td>12D</td><td>Compressed air</td>

<td>A, B, C</td><td>Friction coefficient pattern</td>

<td>V1, V2</td><td>Velocity of displacement</td>

BEST WAY (S) TO CARRY OUT THE INVENTION

Illustrative embodiments of a train braking device according to the present invention will now be described in detail with reference to the accompanying drawings. The present invention is not limited to embodiments.

First form of realization

[0013] FIG. 1 is an example of a configuration of a train braking device according to a first embodiment. A train braking device 11 shown in FIG. 1 includes, as main constituent elements, a speed sensor 1, a brake command unit 2, an air brake controller 3, an electro-pneumatic conversion valve 4, a relay valve 5, a pressure sensor 6, a pressure cylinder. brake 7, a brake shoe 8, a wheel 10 and an air tank 12.

[0014] The speed sensor 1 can be placed on the front and rear wagons of the respective vehicles (four in total) and reach a speed signal 1D of the wheel 10. A speed input unit 3a can retrieve the speed signal 1D of the speed sensors 1a to 1d of each of the vehicles.

The brake command unit 2 can issue a 2D brake command to obtain the predetermined deceleration. The air brake controller 3 can receive the 2D brake command transmitted from the brake command unit 2 and a load compensation signal transmitted from a load compensation device (not shown) to detect the weight of each vehicle. to output a 3D predetermined pressure control signal. The pressure control signal 3D is transmitted through the electropneumatic conversion valve 4 to the relay valve 5 and is used to generate a pressure from the brake cylinder 5D.

The electropneumatic conversion valve 4 can convert the 3D pressure control signal (an electrical signal) transmitted from the air brake controller 3 into air at a predetermined pressure (a pneumatic signal). The relay valve 5 is used to amplify the pressure control signal 3D converted into the pneumatic signal to have a predetermined value for improving a pressure response of the brake cylinder 5D. The air tank 12 is connected to the relay valve 5. Air at a predetermined pressure (hereinafter compressed air) is reserved in the air tank 12, and thus the relay valve 5 emits compressed air 12D corresponding to the 3D pressure control signal to generate a predetermined brake cylinder pressure 5D.

[0017] The pressure sensor 6 can detect the pressure of the brake cylinder 5D, generate a feedback command 6D based on the pressure of the brake cylinder 5D, and feed the feedback command 6D back to the air brake controller 3 As a result, the air brake controller 3 can calculate the 3D pressure control signal accurately.

The brake cylinder 7 can press the brake shoe 8 according to a magnitude of the pressure of the brake cylinder 5D. The brake shoe 8 has a predetermined coefficient of friction 23, and the brake force of each wheel 10 can be obtained from the product of the coefficient of friction 23 and the pressure of the brake cylinder 5D. To equalize the brake forces of the wheels 10, it suffices that the pressure of the brake cylinder 5D is set to be low, for example, when the coefficient of friction 23 of the brake shoe 8 is high, and the pressure of the brake cylinder 5D is set to be high, for example, when the coefficient of friction 23 of the brake shoe 8 is low.

[0019] FIG. 3 is an example of a friction coefficient setting table. A friction coefficient setting table 20 shown in FIG. 3 consists of a concept that indicates a level of a brake notch 21 and a concept that indicates an initial brake speed 22 (the speed of a train when it begins to apply a brake).

[0020] In the concept of brake notch 21, B1 to B7 are shown as a plurality of levels of brake notch

twenty-one. A plurality of predetermined friction coefficients 23 are recorded for calculating the pressure of the brake cylinder 5D in each brake notch concept 21. Each brake notch concept 21 corresponds to a brake notch level in the command unit brake 2, and the friction coefficient setting table 20 is set such that the friction coefficient 23 is changed in accordance with the level of the brake groove. The type of brake groove 21 shown in FIG. 3 is merely an example and is not limited to a seven-step type.

ES 2 396 491 T3

[0021] In the concept of brake initial speed 22 a plurality of initial brake speeds are shown. As described above, the plurality of predetermined coefficients of friction 23 are recorded in each concept of the initial brake speed. The coefficient of friction 23 is changed as a function of the initial brake speed 22. The brake notch 21 corresponds to the initial brake speed 22. For example, when B1 is selected at the brake notch 21, the coefficient of friction 23 is µ13 when the initial brake speed 22 is 60. As the travel speed then decreases, the coefficient of friction 23 also changes. Although 0 km / h to 120 km / h is set in steps of 20 km / h as the initial brake speed 22 shown in FIG. 3, the present invention is not limited to this configuration.

Although the friction coefficient 23 is indicated as, for example, µ10 or µ20 in the friction coefficient setting table 20, this is merely an example and predetermined values ​​can be arbitrarily set. Each of the friction coefficients 23 can be adjusted more finely. Furthermore, a plurality of friction coefficient setting tables 20 can be configured for friction coefficients 23 of a plurality of brake shoes 8.

[0023] FIG. 2 is a block diagram of the air brake controller functions. The air brake controller 3 is configured to include a speed input unit 3a, a friction coefficient calculating unit 3b, a brake force calculating unit 3c and an emission unit 3d.

The speed sensors 1a to 1d can detect the speed signal 1D using the number of revolutions of the wheels. The speed input unit 3a can receive the speed signal 1D transmitted from the speed sensors 1a to 1d.

The friction coefficient calculating unit 3b can calculate the friction coefficient 23 corresponding to the speed of movement of a train for each of the brake shoes 8. That is, the friction coefficient calculating unit 3b can calculate the initial brake speed 22 by the speed signal 1D, check the initial brake speed 22 in the friction coefficient setting table 20, and calculate the coefficient of friction 23 corresponding to initial brake speed 22.

[0026] When the 2D brake command is received, the brake force calculating unit 3c can calculate, with respect to the friction coefficient 23 calculated by the friction coefficient calculating unit 3b, the friction coefficient 23 which corresponds to the brake notch 21, and the 3D pressure control signal using the calculated friction coefficient 23.

[0027] A process for calculating the 3D pressure control signal is described. With reference to FIGS. 1 and 2, the signal emitted by the air brake controller 3 is the 3D pressure control signal. However, the pressure of the brake cylinder 5D is obtained by amplifying the pressure control signal 3D and this pressure of the brake cylinder 5D acts on the brake shoe 8. Therefore, in the following explanations, the pressure control signal 3D is described as the pressure of the brake cylinder 5D.

The friction coefficient calculating unit 3b calculates the friction coefficient 23 corresponding to the initial brake speed 22 using the speed signal 1D. When the 2D brake command transmitted from the brake command unit 2 is received, the brake force calculating unit 3c calculates the friction coefficient 23 corresponding to the brake notch 21.

[0029] The pressure of the brake cylinder 5D can be calculated by the formula B = F / (k * f) (B: ​​brake cylinder pressure, F: brake force, k: constant, f: friction coefficient 23 ). The brake force calculation unit 3c substitutes the friction coefficient 23 corresponding to the initial brake speed 22 and the brake notch 21 and a value of the brake force necessary for braking for the above formula in order to calculate the pressure of the brake cylinder 5D continuously.

[0030] A general operation of the train braking device 11 is described using specific values. The friction coefficient calculating unit 3b calculates the initial brake speed 22 using the speed signal 1D. For example, when the initial brake speed 22 is 60 km / h, the friction coefficient calculation unit 3b calculates any of μ13 to μ73 in the friction coefficient setting table 20.

[0031] When the 2D brake command is received, the brake force calculating unit 3c selects µ13 in the case that, for example, the brake notch 21 is B1. The brake force calculating unit 3c further calculates the pressure of the brake cylinder 5D using the friction coefficient 23 μ13 and a value of the necessary brake force.

[0032] When the brake force calculating unit 3c continues to receive the 2D brake command, the traveling speed of a train continues to decrease. The friction coefficient calculating unit 3b can calculate the friction coefficient 23 continuously in accordance with changes in the displacement speed. That is, as long as the brake force calculation unit 3c continues to receive the 2D brake command, the friction coefficient 23

ES 2 396 491 T3 can be varied. For example, when the initial brake speed 22 is 60 km / h, and the brake notch 21 is B1, μ 13 is first selected as the coefficient of friction 23. When thereafter the unit for calculating the driving force brake 3c keeps receiving 2D brake command, the friction coefficient 23 changes continuously, such as μ13—&gt; μ12—&gt; μ11—&gt; μ10. In addition, the brake force calculating unit 3c can calculate the pressure of the brake cylinder 5D continuously from the friction coefficients 23 μ10 to μ13 and the value of the brake force. Even when the brake notch 21 is changed from B1 to B2 during operation, the friction coefficient 23 can be continuously changed.

[0033] FIG. 5 is a flow chart of an example of a flow of determining a pressure in the brake cylinder using a friction coefficient setting table. The friction coefficient calculating unit 3b and the brake force calculating unit 3c receive the speed signal 1D (step S51) to calculate the friction coefficient 23 corresponding to the initial brake speed 22. Upon receiving the 2D brake command (Yes in step S52), the friction coefficient calculating unit 3b and the brake force calculating unit 3c calculate the friction coefficient 23 corresponding to the brake notch 21 using the friction coefficient setting table 20 (step S53). The friction coefficient calculating unit 3b and the brake force calculating unit 3c calculate the pressure of the brake cylinder 5D (the 3D pressure control signal) by the friction coefficients 23 and the value of the brake force (step S54). The emission unit outputs the brake cylinder pressure 5D (3D pressure control signal) calculated by the friction coefficient calculating unit 3b and the brake force calculating unit 3c to the electropneumatic conversion valve 4 (stage S55). When the transmission of the brake command 2D is finished (YES in step S56), the air brake controller 3 finishes releasing the pressure from the brake cylinder 5D.

When the friction coefficient calculating unit 3b and the brake force calculating unit 3c do not receive the 2D brake command (NO in step S52), these units do not calculate the friction coefficient 23 until receiving the 2D brake command. When the 2D brake command continues to be transmitted (NO in step S56), the friction coefficient calculating unit 3b and the brake force calculating unit 3c repeat the processes after step S53 and calculate the pressure of the brake. brake cylinder 5 D corresponding to the displacement speed continuously from the friction coefficient 23 and the value of the necessary brake force.

As described above, the train braking device 11, according to the first embodiment, uses the friction coefficient setting table 20 to vary the friction coefficient 23 of each of the brake shoes 8 according to a change in the speed of travel of a train. Therefore, a stable deceleration of the whole train can be obtained. As the difference in maximum adhesion between the wheels 10 (the longitudinal force acting on a contact part of the wheel 10 and a rail) can be reduced, for example, it can reduce the probability that a train will slip at the moment emergency braking and the stopping distance can be shortened compared to conventional cases. In addition, since the probability of a train slipping can be reduced, the generation of flattening of each of the wheels 10 is reduced (a damage generated when the wheel 10 is blocked) and the number of cutting processes can be suppressed. wheel 10, noise and vibrations while the train is traveling and deterioration in driving comfort. Since the cutting of the wheel 10 is reduced, the wheel 10 can be used for a long time.

Second way of realization.

The train braking device 11, according to a second embodiment, is configured to reduce the difference in the coefficient of friction 23 caused by a difference in the period of use between the brake shoes 8 and the achievement of the stable deceleration. The configuration of the train braking device 11 of the second embodiment is identical to that of the first embodiment in FIGS. 1 and 2.

[0037] A braking force of the product of the brake cylinder pressure 5D and the friction coefficient 23 can be obtained as described above. Although the replacement cycles of the brake shoes 8 are different from each other depending on the number of passengers and the environments of use, the coefficient of friction 23 of the brake shoe 8 generally decreases as the period of use increases. That is, the friction coefficient 23 of the brake shoe 8, whose replacement time is earlier and whose travel distance (period of use) is long, is less than that of the brake shoe 8 whose replacement time is recent . In a train in which one brake shoe 8 whose replacement time is earlier and the other brake shoe 8 whose replacement time is recent are used together, when an air brake is actuated, one of the wheels 10 is braked appropriately , but the other wheel 10 may slide past the maximum adhesion between the wheel 10 and a rail, because the braking force is too strong. The braking force depends substantially on the coefficient of friction 23. Accordingly, if the difference in the friction coefficient 23 between the wheels 10 can be reduced, a stable braking force can be achieved. The train braking device 11, according to the second embodiment, is therefore configured to provide a plurality of patterns of friction coefficients for various periods of use of the brake shoes 8 in the air brake controller 3 to vary the coefficient of friction 23 of each of the brake shoes 8.

[0038] FIG. 4 is an example of coefficient of friction patterns. The vertical axis indicates the coefficient of friction 23 of the brake shoe 8 and the horizontal axis indicates the speed of travel of a train. Three lines indicated by

ES 2 396 491 T3 a solid line, a dotted line and a dashed line in FIG. 4 are examples of the friction coefficient patterns mentioned above.

[0039] A friction coefficient pattern A is assigned for the brake shoe 8 in a case where the travel distance is from 0 km to X1 km (not much time has elapsed since the time of the previous replacement). A friction coefficient pattern B is assigned for the brake shoe 8 in a case where the travel distance is Χ1 km to X2 km. A pattern of friction coefficients C is assigned for the brake shoe 8 in a case where the travel distance is X2 km to X3 km (a long time has passed since the time of the previous replacement). The friction coefficient patterns A through C are just examples. The present invention does not limit the friction coefficient pattern to three, more patterns can be established. You can set values ​​from X1 to X3 arbitrarily.

As for the friction coefficient 23 that corresponds to the travel speed, for example, when the forward speed is V1 km / h, the friction coefficient is μ1 in the case that the friction coefficient pattern is A ”, μ2 in the case that the friction coefficient pattern is B, and μ3 in the case that the friction coefficient pattern is C. μ1 to μ3 are predetermined friction coefficients 23 for calculating the pressure of the 5D brake cylinder.

[0041] Although a dynamic coefficient of friction (a coefficient of friction when an object is moving) generally indicates a constant value, it can be proportionally inverse to the speed of displacement when a friction force is several to several tens percent. . In a region from a travel speed V2 to the travel speed V1 shown in FIG. 4, the coefficient of friction 23 is almost fixed when the speed of travel changes. In a region from the travel speed V1 to 0 km / h, however, the friction coefficient 23 increases as the travel speed decreases. This phenomenon is common to the friction coefficient patterns A to C.

[0042] As described above, the friction coefficient 23 of the brake shoe 8 varies as a function of the speed of movement of a train and the time for the replacement of the brake shoe 8. The train braking device 11 , according to the second embodiment, it is configured to set these variations in advance to control the pressure of the brake cylinder 5D appropriately. That is, in the train braking device 11, the air brake controller 3 records in it the time for the replacement of each of the brake shoes 8, calculates the travel distance using the time for replacement as the point starting, and obtains each of the friction coefficient patterns A through C for the displacement distance. Furthermore, the friction coefficient of each of the brake shoes 8 can be calculated by the relationship between each of the friction coefficient patterns A to C and the speed of travel of a train.

[0043] In FIG. 2, the friction coefficient calculating unit 3b can calculate the friction coefficient 23 of each of the brake shoes 8 for the traveling distance of a train. That is, the friction coefficient calculating unit 3b calculates the travel distance using the speed signal 1D and then any of the friction coefficient patterns A to C using the calculated travel distance. The friction coefficient calculating unit 3b checks the forward speed with respect to the friction coefficient patterns A to C to calculate the friction coefficient 23 for each friction coefficient pattern.

The brake force calculating unit 3c receives the 2D brake command transmitted from the brake command unit 2 to calculate a brake force for the 2D brake command. The brake force calculating unit 3c then calculates the pressure of the brake cylinder 5D, using the friction coefficient 23 calculated for each of the friction coefficient patterns and the value of the brake force mentioned above.

[0045] A general operation of the train braking device 11 is described using specific values. The friction coefficient calculating unit 3b calculates the travel distance using the speed signal 1D. For example, when the travel distance is X1 km to X2 km on a brake shoe 8, the friction coefficient pattern B is obtained for that brake shoe 8. Also, when the travel speed is V1, the travel speed V1 is checked against the friction coefficient pattern B to calculate the friction coefficient 23, that is, μ2.

The brake force calculating unit 3c receives the 2D brake command transmitted from the brake command unit 2 to calculate the brake force for the 2D brake command. Furthermore, the brake force calculating unit 3c calculates the pressure of the brake cylinder 5D, using the friction coefficient 23, that is, μ2 and the value of the brake force.

[0047] The friction coefficient patterns A to C can be calculated for each of the brake shoes 8. For the friction coefficient 23, for example, μ1 calculated using the displacement speed V1 and the friction coefficient pattern A and the coefficient of friction 23, for example, μ3 calculated using the speed of

ES 2 396 491 T3 displacement V1 and the pattern of friction coefficients C, the pressure of the brake cylinder 5D can be calculated for each of the brake shoes 8.

In the friction coefficient calculating unit 3b, the friction coefficient 23 can be provided by combining the friction coefficient patterns A to C and the friction coefficient setting table 20 shown in FIG. 3. That is, by setting the friction coefficient setting tables 20 to the respective friction coefficient patterns A, B, and C in advance in the friction coefficient calculation unit 3b, the friction coefficient 23 can be obtained as a function of a change in the speed of a train, a brake notch, and the period of use of the brake shoe 8.

[0049] FIG. 6 is a flow chart of an example of a flow for determining a pressure in the brake cylinder using a pattern of friction coefficients. The friction coefficient calculating unit 3b and the brake force calculating unit 3c receive the speed signal 1D (step S61) and calculate the travel distance using the speed signal 1D to provide the pattern of friction coefficients. for each of the brake shoes 8 (step S62). When the friction coefficient calculating unit 3b and the brake force calculating unit 3c receive the 2D brake command (YES in step S63), the units check the travel speed with the pattern of friction coefficients and calculate the coefficient of friction 23 (step S64). The friction coefficient calculating unit 3b and the brake force calculating unit 3c calculate the brake cylinder pressure 5D (the 3D pressure control signal) using the friction coefficient 23 and the value of the brake force. brake (step S65). The emission unit 3d outputs the brake cylinder pressure 5D (3D pressure control signal) calculated by the friction coefficient calculating unit 3b and the brake force calculating unit 3c to the electropneumatic conversion valve 4 ( step S66). When the transmission of the brake command 2D is finished (YES in step S67), the air brake controller 3 finishes releasing the pressure from the brake cylinder 5D.

[0050] When the friction coefficient calculating unit 3b and the brake force calculating unit 3c do not receive the 2D brake command (NO in step S63), these units do not calculate the friction coefficient 23 until receiving the 2D brake command. When the 2D brake command continues to be transmitted (NO in step S67), the friction coefficient calculating unit 3b and the brake force calculating unit 3c repeat the processes after step S64 and continuously calculate the pressure. of the brake cylinder 5 D corresponding to any of the friction coefficient patterns A to C and the travel speed using the friction coefficient 23 and the necessary brake force value.

[0051] As described above, according to the train braking device 11 of the second embodiment, the pattern of friction coefficients corresponding to the period of use of each of the brake shoes 8 is obtained and the coefficient of friction 23 of each of the brake shoes 8. In this way, a stable deceleration of the whole train can be obtained. Since the difference in maximum adhesion between the wheels 10 can be reduced, the probability of a train slipping at the time of emergency braking can be reduced, and the stopping distance can be reduced compared to conventional cases. Furthermore, as the probability of a train slipping can be reduced, the generation of flattening of each of the wheels 10 is reduced and the number of cutting processes of the wheel 10, noise and vibrations while traveling can be suppressed. the train and the deterioration in driving comfort. Furthermore, since the cutting of the wheel 10 is reduced, the wheel 10 can be used for a long time. Even when the friction coefficients 23 of the brake shoes 8 are different from each other, a stable brake force can be achieved. Accordingly, the replacement operation of the brake shoe 8 is eliminated so that the friction coefficients 23 coincide with each other, and therefore, the costs related to the replacement of the brake shoe 8 can be reduced and the brake shoe brake 8 can be used for a long period.

INDUSTRIAL APPLICABILITY

[0052] As described above, the train braking device according to the present invention serves as a train braking device having an air brake controller.