Railway vehicle and container for cargo transportation

Abstract

To provide a railway vehicle and a container for cargo transportation that can prevent overturning caused by a crosswind.SOLUTION: A railway vehicle has a recess portion at an upper corner section in a cross section taken along a direction intersecting a vehicle travel direction, and the recess portion is continuously formed along the vehicle travel direction.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a railway vehicle having a function of preventing overturning due to crosswind and a cargo transportation container.

Background Art

[0002] Conventionally, regarding the prevention of overturning of railway vehicles, as countermeasures on the operation side, measures such as reducing the wind speed regulation value in a specific section, and as countermeasures on the equipment side, measures such as installing a windbreak are known.

[0003] Also, various vehicle structures are known as countermeasures for preventing overturning on the vehicle side. For example, as described in Patent Document 1, an overturning prevention device for a vehicle against crosswind, which is provided on the ceiling surface of the vehicle and has a wing-shaped portion whose cross-sectional shape viewed from the front direction of the vehicle is wing-shaped, and a brake plate provided on the wing-shaped portion on the ceiling surface of the vehicle. The wing-shaped portion is adjusted in inclination with respect to the crosswind to generate aerodynamic force in a predetermined direction when the crosswind occurs. The aerodynamic force has a component acting in the vertically downward direction, and the brake plate generates a force in the direction opposite to the traveling direction of the vehicle. A vehicle overturning prevention device is known.

[0004] Also, as one of the measures for improving the aerodynamic stability of a structure having a rectangular cross-section, research on the girders of long bridges as described in Patent Document 2 is known.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Non-Patent Documents

[0006]

Non-Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0007] According to the vehicle rollover prevention device as described in Patent Document 1, when a crosswind occurs, aerodynamic force can be generated by the airfoil portion, and by adjusting the inclination of the airfoil portion, aerodynamic force having a component acting vertically downward can be generated. The aerodynamic force generated vertically downward acts to press the vehicle against the rail, increasing the wheel load of the vehicle and preventing the vehicle from rolling over.

[0008] However, in the invention described in Patent Document 1, since the rollover prevention device is installed on the ceiling surface of the vehicle, there are problems such as an increase in vehicle body weight, and the center of gravity position moves upward, which adversely affects the rollover of the vehicle. Further, when a railway vehicle consists of a bogie and a cargo transportation container, there is a problem that the rollover prevention device becomes an obstacle and the stacking function of the cargo transportation container is impaired.

[0009] Also, according to research such as Patent Document 2, by changing the shape of the cross-sectional corner portion, aerodynamic force can be reduced, and harmful vibrations such as those of a bridge girder can be suppressed.

[0010] However, the research described in Patent Document 2 targets structures located at locations away from the ground, such as long bridge piers and the main towers of suspension bridges, and no similar research has been conducted on railway vehicles running on the ground.

[0011] Therefore, the present invention has been made in view of the above matters, and an object of the present invention is to provide a railway vehicle and a cargo transportation container that can prevent the vehicle from rolling over due to a crosswind by the shape of the railway vehicle and the cargo transportation container itself without attaching a rollover prevention device to the ceiling surface of the vehicle.

Means for Solving the Problem

[0012] This invention has been made to achieve the above problems and is characterized by the following.

[0013] The railway vehicle according to the present invention is provided with a recess in the upper corner portion in a cross section in a direction intersecting the vehicle traveling direction, and the recesses are formed in series along the vehicle traveling direction.

[0014] In the railway vehicle according to the present invention, it is preferable that the recess is formed in a stepped shape.

[0015] In the railway vehicle according to the present invention, it is preferable that the recess is formed in a single-step shape.

[0016] The cargo container according to the present invention is provided with a recess in the upper corner portion in a cross section in a direction intersecting the vehicle traveling direction, and the recesses are formed in series along the vehicle traveling direction.

[0017] In the cargo container according to the present invention, it is preferable that the recess is formed in a stepped shape.

[0018] In the cargo container according to the present invention, it is preferable that the recess is formed in a single-step shape.

[0019] In the cargo container according to the present invention, it is preferable to include a support device for supporting the load loaded on the upper part.

[0020] The above summary of the invention does not list all the features necessary for the present invention, and sub-combinations of these feature groups can also be inventions.

Advantages of the Invention

[0021] According to the present invention, it is possible to prevent the overturning of railway vehicles and cargo transportation containers caused by crosswinds without installing an anti-overturning device or the like. Further, according to the present invention, since there is no need to install an anti-overturning device or the like on the ceiling surface, the stacking function of the cargo transportation container is not impaired.

Brief Description of the Drawings

[0022]

Figure 1

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Figure 12

Mode for Carrying Out the Invention

[0023] Hereinafter, preferred embodiments for carrying out the present invention will be described with reference to the drawings. It should be noted that the following embodiments do not limit the invention according to each claim, and not all combinations of the features described in the embodiments are essential for the solution means of the invention.

[0024] Fig. 1 is a cross-sectional view in a direction intersecting the vehicle traveling direction schematically showing the shapes of the railway vehicle and the freight container of the present invention. In the following description, the cross-section in the direction intersecting the vehicle traveling direction is also referred to as the "vehicle cross-section" or simply the "cross-section". Further, although the following description is made by taking a railway vehicle as an example, since a freight vehicle with a freight container placed on the loading platform has a similar form, detailed description of these will be omitted.

[0025] As shown in Fig. 1, the railway vehicle 1 according to the present embodiment includes a recess 2 at at least one of the upper corner portions on the left and right sides of the railway vehicle 1 in the vehicle cross-section. It should be noted that the recess 2 is preferably provided at the upper corner portions on both the left and right sides in the vehicle cross-section of the railway vehicle 1 because the air force reduction effect described later can be obtained against crosswinds from either side.

[0026] The recess 2 is formed in a series along the vehicle traveling direction. Further, the recess 2 preferably has a stepped cross-sectional shape, and more preferably has a single-step stepped shape.

[0027] Next, the state of the flow when the railway vehicle 1 according to the present embodiment is affected by a crosswind will be described. Fig. 2 is a cross-sectional view schematically showing the state of the crosswind flow in the railway vehicle of the present invention.

[0028] As shown in FIG. 2, the crosswind from the side of the railway vehicle 1 becomes a separated flow at the edge A located at the lower part of the recess 2, and then the separated flow hits the edge B located at the upper part of the recess 2. At the edge B, the separated flow from the edge A interferes with the separated flow newly generated by the crosswind at the edge B. Due to this interference, the separated flow approaches the ceiling surface of the railway vehicle 1 and does not develop into a large separation, and the aerodynamic characteristics can be stabilized.

[0029] Note that such actions and effects have been confirmed by a wind tunnel test in Patent Document 2 when a cut-off is formed at the pier. However, as described above, since the research targets structures without the ground around them such as bridge girders and main towers, when applied to railway vehicles running on the ground, the effect of reducing aerodynamic force may be limited. In addition, in the railway vehicle 1, there is a problem that the volume of the passenger compartment and the loadable capacity of the container are reduced compared with the conventional case by providing the recess 2. Furthermore, since the railway vehicle 1 has restrictions such as vehicle limits, there is a problem that it is difficult to recover the reduced volume by the recess 2 by increasing the vehicle height and vehicle width. For this reason, it is necessary to study the shape of the recess 2 that can effectively exhibit the effect of reducing aerodynamic force without excessively reducing the volume of the passenger compartment or the like.

[0030] First, the forces acting on the railway vehicle 1 receiving the crosswind will be described. FIG. 3 is a schematic diagram showing the main forces acting on a railway vehicle receiving the crosswind, and FIG. 4 is a reference diagram showing indexes for evaluating the aerodynamic force acting on a railway vehicle receiving the crosswind.

[0031] As shown in FIG. 3, external forces such as aerodynamic force, gravity G, centrifugal force CF, and lateral vibration inertial force IF due to the crosswind act on the railway vehicle 1 receiving the crosswind. Among these, the aerodynamic force due to the crosswind is divided into a lateral force S that pushes the vehicle in the lateral direction, a lift force L that lifts the vehicle upward, and a moment M1 around the longitudinal axis of the vehicle. Due to these forces, a moment M2 centered on the contact point P between the wheel on the leeward side and the rail acts on the railway vehicle 1.

[0032] As the crosswind speed increases, the moment M2 increases, and as shown in FIG. 3, the force F1 pushing the upstream rail decreases. Also, when the crosswind reaches a certain wind speed, the force F1 pushing the upstream rail becomes zero. If such a crosswind continues to act on the railway vehicle 1, the upstream wheels will lift off the rails, and the railway vehicle 1 will overturn.

[0033] When considering the overturning of the railway vehicle 1, since the aerodynamic force due to the crosswind has a large contribution to the reduction rate of the force F1 pushing the upstream rail as described above, it is important to accurately evaluate the aerodynamic force due to the crosswind.

[0034] Next, an explanation will be given of the indices for evaluating the lateral force S, lift force L, and moment M1, which are the aerodynamic forces due to the crosswind.

[0035] Generally, the aerodynamic force due to the crosswind can be expressed in a form proportional to the square of the wind speed, and the aerodynamic force coefficient is known as the coefficient representing the relationship between the wind speed and the aerodynamic force. The aerodynamic force coefficients related to the lateral force S, lift force L, and moment M1 are respectively the lateral force coefficient C S 、the lift force coefficient C L and the moment coefficient C M and can be expressed by the following equations.

[0036]

Equation

Equation

Equation

[0037] Here, ρ is the air density, U is the wind speed, and A is the vehicle body side area.

[0038] Also, the aerodynamic force coefficient related to the moment M2 around the contact point P is the lateral force coefficient C S 、the lift force coefficient C L and the moment coefficient C MUsing this, the rolling moment coefficient CM_lee can be expressed by the following equation.

[0039]

Number

[0040] Here, as shown in FIG. 4, h is the vehicle body height, h C is the height from the contact point P to the vehicle body center, and b is the distance in the width direction from the contact point P to the vehicle body center. Also, in this specification, the rolling moment coefficient CM_lee is treated as an index that can comprehensively evaluate the aerodynamic force from the viewpoint of the overturning of the railway vehicle 1. For example, a low value of the rolling moment coefficient CM_lee means that the vehicle is less affected by the aerodynamic force due to a crosswind.

[0041] Next, a small wind tunnel test is conducted to confirm the aerodynamic force reduction effect of the railway vehicle 1 provided with the recess 2.

[0042] FIG. 5 is a drawing showing a measurement vehicle that is the subject of a small wind tunnel test, (a) is a side view showing the side of the vehicle, (b) is a cross-sectional view taken along the line C-C of FIG. 5(a), (c) is a diagram showing a list of the dimensions of part a and part c of FIG. 5(b), and FIG. 6 is the result of a small wind tunnel test on the measurement vehicle shown in FIG. 5, which is a graph showing the rolling moment coefficient ratio.

[0043] The small wind tunnel test is conducted using a 1 / 60 scale model of the actual railway vehicle 1, and is carried out on measurement vehicles No. 01 to No. 05 having the cross-sectional shapes shown in FIGS. 5(b) and (c). Inside each measurement vehicle, sensors for measuring the lateral force S, the lift force L, and the moment M1 are attached.

[0044] Also, this small wind tunnel test is conducted for two types of measurement vehicles: one with the bogie 11 and the skirt-shaped underfloor member 12 shown in FIGS. 5(a) and (b) attached, and the other without them. Note that this small wind tunnel test is carried out with a plurality of vehicles connected, and vehicles are connected in front of and behind the measurement vehicle with the sensor attached.

[0045] In addition, this small wind tunnel test is carried out on the condition that the rail and the measurement vehicle are installed on a flat plate, and the crosswind blows from directly side at 90° to the traveling direction of the measurement vehicle as a uniform flow.

[0046] As shown in FIGS. 5(b) and (c), the cross-sectional shape of the measurement vehicle No.01 is a rectangle with a vehicle body height of about 46.7 mm and a vehicle body width of about 40.7 mm, and the upper corner does not have a shape such as a recess.

[0047] The cross-sectional shapes of the measurement vehicles No.02 to No.05 have the same dimensions of the vehicle body height and the vehicle body width as those of the measurement vehicle No.01, and each has a recess of 2 mm, 5 mm, 8 mm, and 10 mm square at the upper corner.

[0048] In this small wind tunnel test, it is assumed that the measurement vehicle No.01 corresponds to a conventional railway vehicle. Based on the measurement vehicle No.01, the rolling moment coefficient CM_lee obtained from the tests on each measurement vehicle is compared to confirm the air force reduction effect.

[0049] According to the results of the small wind tunnel test shown in FIG. 6, it can be confirmed that for any of the measurement vehicles No.02 to No.05, the rolling moment coefficient CM_lee is lower than that of the measurement vehicle No.01 as the reference shape. That is, it was confirmed that by forming a stepped recess at the upper corner of the measurement vehicle, the influence of the crosswind on the air force can be reduced regardless of the size of the recess.

[0050] In addition, it can be confirmed that the air force reduction effect is such that the larger the a-part dimension and the b-part dimension of the recess, the lower the rolling moment coefficient CM_lee. However, as is clear from the comparison of the test results of the measurement vehicles No.04 and No.05, it was also confirmed that when the size of the recess exceeds a certain magnitude, the air force reduction effect with respect to the size of the recess becomes weak. Thus, it is considered possible to obtain the optimum value of the cross-sectional dimension of the recess that can sufficiently exert the effect without excessively reducing the internal volume of the vehicle body by further examining the cross-sectional dimension of the stepped recess.

[0051] Further, when comparing the measurement vehicle with the carriage 11 and the underfloor member 12 attached thereto and the measurement vehicle without these attached, it can be confirmed that in both measurement vehicles, the reduction effect of aerodynamic force is higher when the carriage 11 and the underfloor member 12 are attached. Thus, it is considered that by further examining the shape of the underfloor member 12, it is also possible to achieve a higher reduction effect of aerodynamic force.

[0052] Next, a confirmation is made regarding the reduction effect of aerodynamic force due to differences in the shape of the recess 2 formed at the upper corner portion of the railway vehicle 1.

[0053] FIG. 7 is a drawing showing a measurement vehicle that is the subject of a small wind tunnel test, and is a diagram showing a list of measurement vehicles with the shape of the upper corner portion changed. FIG. 8 is a result of a small wind tunnel test for the measurement vehicle shown in FIG. 7, and is a graph showing the rolling moment coefficient ratio.

[0054] This small wind tunnel test is carried out under the same conditions as the test targeting the above-described measurement vehicles No. 01 to No. 05.

[0055] The cross-sectional shape of the measurement vehicle No. 11 is the same as that of the above-described measurement vehicle No. 01, and is a rectangle with a vehicle body height of about 46.7 mm and a vehicle body width of about 40.7 mm, and does not have a shape such as a recess at the upper corner portion. Also, taking the measurement vehicle No. 11 as a reference shape corresponding to a conventional railway vehicle, the rolling moment coefficient CM_lee of the measurement vehicles No. 12 to No. 14 described later is compared to confirm the reduction effect of aerodynamic force.

[0056] The cross-sectional shape of the measurement vehicle No. 12 has the same dimensions for the vehicle body height and the vehicle body width as those of the measurement vehicle No. 11, and has a 8 mm square recess at the upper corner portion.

[0057] The cross-sectional shape of the measurement vehicle No. 13 has the same dimensions for the vehicle body height and the vehicle body width as those of the measurement vehicle No. 11, and has an inclined surface portion with a vertical dimension and a horizontal dimension of 8 mm each at the upper corner portion.

[0058] The cross-sectional shape of the measurement vehicle No. 14 has the same dimensions of vehicle body height and vehicle body width as those of the measurement vehicle No. 11, and is provided with a curved surface portion with a radius of 8 mm at the upper corner portion.

[0059] According to the results of the small wind tunnel test shown in Fig. 8, it can be confirmed that the measurement vehicle No. 12 with a stepped recess formed at the upper corner portion has a lower rolling moment coefficient CM_lee than the measurement vehicles No. 13 and No. 14 with an inclined surface portion or a curved surface portion formed at the upper corner portion. That is, the air force reduction effect varies depending on the difference in the shape of the upper corner portion of the measurement vehicle. It can be confirmed that even if the shape dimensions from the side surface and the ceiling surface of the measurement vehicle are the same, forming the shape in a stepped manner rather than in an inclined surface or a curved surface has a higher air force reduction effect.

[0060] As described above, by forming the recess 2 at the upper corner portion of the railway vehicle 1, the air force reduction effect acting on the railway vehicle 1 can be enhanced, and it was confirmed that it is preferable that the shape of the recess 2 is stepped.

[0061] Note that Fig. 9 shows the results of the small wind tunnel test and is a graph showing the rolling moment coefficient ratio when the form of the vehicles connected before and after the measurement vehicle to which the sensor is attached is changed. This small wind tunnel test was conducted under the same test conditions as the test targeting the above-described measurement vehicle No. 12.

[0062] The rolling moment coefficient ratio of the measurement vehicle No. 12 shown in Fig. 9 is the value under the condition that vehicles having the same shape as the measurement vehicle No. 11 with the reference shape are connected before and after the vehicle to which the sensor is attached. Also, the rolling moment coefficient ratio of the measurement vehicle No. 12' is the value under the condition that vehicles having recesses are connected before and after the vehicle to which the sensor is attached.

[0063] According to the results of the small wind tunnel test shown in Fig. 9, it can be confirmed that the condition of connecting vehicles having recesses has a lower rolling moment coefficient CM_lee and a higher air force reduction effect than the condition of connecting vehicles having no recesses before and after the vehicle to which the sensor is attached.

[0064] Next, as conditions closer to the actual running state of railway vehicles, a large-scale wind tunnel test was conducted assuming a case where the rails and the measurement vehicle are on a structure such as a double-track viaduct, the crosswind flow is turbulent, and the wind direction is different, and the reduction effect of the aerodynamic force of the measurement vehicle equipped with the recess was confirmed.

[0065] FIG. 10 is a drawing showing the test conditions of the large-scale wind tunnel test. (a) is a cross-sectional view showing the installation state of the rails and the vehicle, (b) is a cross-sectional view of the measurement vehicle, and (c) is a view showing a list of the dimensions of part a and part c in FIG. 10(b). FIG. 11 is the result of the large-scale wind tunnel test on the measurement vehicle shown in FIG. 10, and is a graph showing the rolling moment coefficient ratio.

[0066] The large-scale wind tunnel test is conducted using a 1 / 40 scale model of an actual railway vehicle, and is carried out for measurement vehicles No. 21 to No. 24 having the cross-sectional shapes shown in FIGS. 10(b) and (c). Inside each measurement vehicle, sensors for measuring the side force S, lift force L, and moment M1 are attached.

[0067] Also, in this large-scale wind tunnel test, as shown in FIG. 10(a), the rails and the measurement vehicle are installed on a pedestal simulating a single-track embankment. The crosswind applied to the measurement vehicle is a turbulent flow that changes at an angle of 30° to 90° with respect to the traveling direction of the measurement vehicle.

[0068] The cross-sectional shape of measurement vehicle No. 21 is a rectangle with a vehicle body height of about 70 mm and a vehicle body width of about 61 mm, and does not have a shape such as a recess at the upper corner.

[0069] The cross-sectional shapes of measurement vehicles No. 22 to No. 24 have the same dimensions for the vehicle body height and vehicle body width as those of measurement vehicle No. 21, and are provided with stepped recesses formed in the dimensions shown in FIG. 10(c) at the upper corner portions, respectively.

[0070] Also, taking measurement vehicle No. 21 as the reference shape corresponding to a conventional railway vehicle, the rolling moment coefficient CM_lee of each measurement vehicle is compared.

[0071] According to the results of the large-scale wind tunnel test shown in FIG. 11, for all wind directions, it was confirmed that the measuring vehicles from No. 22 to No. 24 of the measuring vehicles have a lower rolling moment coefficient CM_lee with respect to the measuring vehicle No. 21 with the reference shape and are less affected by the aerodynamic force due to the crosswind.

[0072] Thus, it was confirmed that even under conditions closer to the actual running state of a railway vehicle, by forming the stepped recess 2 at the upper corner of the railway vehicle 1, it is possible to enhance the effect of reducing the aerodynamic force acting on the railway vehicle 1.

[0073] In the present embodiment, the railway vehicle 1 is described as having a recess 2 at the upper corner in the vehicle cross-section, and the recess 2 is formed in a stepped shape. However, when the recess 2 is formed in a cargo container placed on the loading platform of a freight car, the recess 2 may be provided with support devices 21 and 22 as shown in FIGS. 12(a) and 12(b). The support device 21 is formed in a frame shape and is configured to be able to load heavy objects on the upper part. Also, the inside of the frame of the support device 21 is configured so that wind can pass through. The support device 22 is formed in a rod shape and a plurality of them are installed along the vehicle traveling direction, and is configured to be able to load heavy objects on the upper part. By providing such support devices 21 and 22, even when the railway vehicle 1 is a cargo container for transporting goods, the effect of reducing the aerodynamic force by the recess 2 can be obtained, and like a conventional cargo container for transporting goods, it is possible to load heavy objects on the upper part, such as stacking a plurality of cargo containers for transporting goods. It is clear from the description of the claims that such a modified or improved form can also be included in the technical scope of the present invention.

Explanation of Reference Numerals

[0074] 1 Railway vehicle, 2 Recess, 11 Bogie, 12 Underfloor member, 21, 22 Support device.

Claims

1. In a cross-section in a direction intersecting the vehicle traveling direction, it has a recess at the upper corner, The railway vehicle is characterized in that the recesses are formed in series along the vehicle traveling direction.

2. In the railway vehicle according to Claim 1, The railway vehicle is characterized in that the recesses are formed in a stepped shape.

3. In the railway vehicle according to Claim 1, The railway vehicle is characterized in that the recesses are formed in a single-step shape.

4. In a cross-section in a direction intersecting the vehicle traveling direction, it has a recess at the upper corner, The cargo container is characterized in that the recesses are formed in series along the vehicle traveling direction.

5. In the cargo container according to Claim 4, The cargo container is characterized in that the recesses are formed in a stepped shape.

6. In the cargo container according to Claim 4, The cargo container is characterized in that the recesses are formed in a single-step shape.

7. In the cargo container according to Claim 4, The cargo container is characterized by comprising a support device for supporting the load loaded on the upper part.

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