wheel

Abstract

To provide a wheel which can effectively reduce sound noise generated when a railway vehicle travels.SOLUTION: A wheel (100) comprises a boss part (10), a rim part (20) and a plat part (30). The plate part (30) includes a symmetrical shape with respect to a central axis (A) of the boss part (10). The plate part (30) includes a plate part body (33) and connection parts (31, 32). The plate part body (33) includes a curvature shape. The connection parts (31, 32) connect the plate part body (33) to the boss part (10) and the rim part (20), respectively. The plate part body (33) includes a maximum plate thickness (tmax) in a thickness-increased region (333) while including a minimum plate thickness (tmin) in other regions (334). The thickness-increased region (333) includes the maximum plate thickness (tmax) at a position at a distance of 0.40X to 0.68X inclusive away from an inner peripheral end (E1) outward in a radial direction where X is a distance along the radial direction from the inner peripheral end (E1) of the plate part (30) to outer peripheral end (E2).SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] This disclosure relates to wheels for railway vehicles. [Background technology]

[0002] A wheel for a railway vehicle comprises a boss portion, a rim portion, and a plate portion. The axle is inserted into the boss portion. The rim portion is located outside the boss portion in the radial direction of the wheel. The plate portion is positioned between the boss portion and the rim portion and connects the boss portion to the rim portion.

[0003] Generally, railway vehicles are required to be quiet during operation. For example, in the case of railway vehicles that travel at high speeds, such as Shinkansen bullet trains, the vibration noise generated from the wheels during operation increases with speed. Therefore, it is necessary to reduce vibration noise as much as possible to protect the environment along the railway line. Even for railway vehicles that travel at relatively low speeds, the reduction of vibration noise is required. To explain in more detail, the equivalent noise level, which is the time-averaged value of energy, is usually used to evaluate environmental noise. Even for railway vehicles that travel at relatively low speeds, if there are times when the number of trains running is extremely high, such as during rush hour, the equivalent noise level will be high and the environment along the railway line will deteriorate. Therefore, in order to protect the environment along the railway line, it is also necessary to reduce vibration noise.

[0004] Patent Document 1 discloses a technology for reducing noise generated from the wheels when a railway vehicle is in operation. Patent Document 1 states that noise generated by the vibration of the plate portion accounts for a large proportion of the noise generated by the wheels when a railway vehicle is in operation. Therefore, Patent Document 1 proposes partially increasing the rigidity of the plate portion. More specifically, in the wheel of Patent Document 1, a rigidity-increasing portion is provided in the plate portion that is thicker than other parts. When the length of the plate portion along the radial direction of the wheel is L, the rigidity-increasing portion is provided continuously around the entire circumference of the plate portion at a position 2L / 3 on the outer circumference from the boss portion. Alternatively, multiple rigidity-increasing portions are provided at intervals in the circumferential direction of the plate portion at a position L / 3 on the outer circumference from the boss portion. [Prior art documents] [Patent Documents]

[0005] [Patent Document 1] Japanese Patent Publication No. 2005-262916 [Overview of the project] [Problems that the invention aims to solve]

[0006] The wheel described in Patent Document 1 is intended to reduce noise generated by vibrations of the wheel plate during the operation of a railway vehicle. However, in recent years, the demand for quietness in railway vehicles has increased. Therefore, the noise generated from the wheels during the operation of a railway vehicle needs to be reduced more effectively.

[0007] The object of this disclosure is to provide a wheel that can effectively reduce noise generated when a railway vehicle is in operation. [Means for solving the problem]

[0008] The wheel for a railway vehicle according to the present disclosure includes a boss portion, a rim portion, and a plate portion. The boss portion has a cylindrical shape. The rim portion is disposed outside the boss portion in the radial direction of the wheel. The plate portion is disposed between the boss portion and the rim portion. The plate portion has a shape symmetric with respect to the central axis of the boss portion. The plate portion includes a plate body, a first connecting portion, and a second connecting portion. The plate body has a curved shape when viewed in a cross section including the central axis of the boss portion. The first connecting portion is disposed between the boss portion and the plate body. The first connecting portion connects the plate body to the boss portion. The second connecting portion is disposed between the rim portion and the plate body. The second connecting portion connects the plate body to the rim portion. The plate body includes a thickening region. The plate thickness in the thickening region is larger than that in other regions of the plate body. The plate body has a maximum plate thickness in the thickening region and a minimum plate thickness in other regions. A portion of the first connecting portion having a plate thickness twice the minimum plate thickness is defined as the inner peripheral end of the plate portion, and a portion of the second connecting portion having a plate thickness twice the minimum plate thickness is defined as the outer peripheral end of the plate portion. When the distance along the radial direction from the inner peripheral end to the outer peripheral end is X, the thickening region has a maximum plate thickness at a position 0.40X or more and 0.68X or less outward in the radial direction from the inner peripheral end.

Advantages of the Invention

[0009] According to the wheel of the present disclosure, the noise generated during the running of the railway vehicle can be effectively reduced.

Brief Description of the Drawings

[0010] [Figure 1] FIG. 1 is a longitudinal sectional view of a wheel for a railway vehicle according to an embodiment. [Figure 2] FIG. 2 is a partially enlarged view of the wheel shown in FIG. 1. [Figure 3] FIG. 3 is a view showing the outer shape of a wheel according to Comparative Example 1. [Figure 4] FIG. 4 is a view showing the outer shape of a wheel according to Comparative Example 2. [Figure 5] [[ID=二十七]]FIG. 5 is a view showing the outer shape of a wheel according to Comparative Example 3. [Figure 6] FIG. 6 is a view showing the outer shape of a wheel according to Example 1. [Figure 7]FIG. 7 is a view showing the outer shape of the wheel according to Example 2. [Figure 8] FIG. 8 is a view showing the outer shape of the wheel according to Example 3. [Figure 9] FIG. 9 is a view showing the outer shape of the wheel according to Example 4. [Figure 10] FIG. 10 is a view showing the outer shape of the wheel according to Example 5. [Figure 11] FIG. 11 is a view showing the outer shape of the wheel according to Example 6.

Mode for Carrying Out the Invention

[0011] The wheel for a railway vehicle according to the embodiment includes a boss portion, a rim portion, and a plate portion. The boss portion has a cylindrical shape. The rim portion is disposed outside the boss portion in the radial direction of the wheel. The plate portion is disposed between the boss portion and the rim portion. The plate portion has a shape symmetric with respect to the central axis of the boss portion. The plate portion includes a plate portion body, a first connection portion, and a second connection portion. The plate portion body has a curved shape when viewed in a cross section including the central axis of the boss portion. The first connection portion is disposed between the boss portion and the plate portion body. The first connection portion connects the plate portion body to the boss portion. The second connection portion is disposed between the rim portion and the plate portion body. The second connection portion connects the plate portion body to the rim portion. The plate portion body includes a thickening region. The plate thickness of the thickening region is larger than that of other regions of the plate portion body. The plate portion body has a maximum plate thickness in the thickening region and a minimum plate thickness in other regions. Taking the portion having a plate thickness twice the minimum plate thickness among the first connection portions as the inner peripheral end of the plate portion, and the portion having a plate thickness twice the minimum plate thickness among the second connection portions as the outer peripheral end of the plate portion, and when the distance along the radial direction from the inner peripheral end to the outer peripheral end is X, the thickening region has a maximum plate thickness at a position 0.40X or more and 0.68X or less radially outward from the inner peripheral end (the first configuration).

[0012] Generally, noise is generated primarily from the least rigid part of a structure. In railway vehicle wheels, the rigidity of the plate section is relatively low, making the plate section the main source of noise. Therefore, in the wheel according to the first configuration, the rigidity of the plate section is increased by partially thickening the plate section. Furthermore, in the wheel according to the first configuration, the length X of the plate section is defined as the distance along the radial direction of the wheel from the point where the plate thickness is twice the minimum plate thickness at the connection point of the plate section to the boss section to the point where the plate thickness is twice the minimum plate thickness at the connection point of the plate section to the rim section. The thickened region of the plate section has the maximum plate thickness at a position between 0.40X and 0.68X from the inner circumference end of the plate section. The plate section has an axially symmetric shape, and the cross-sectional shape does not substantially change throughout the entire circumference of the plate section. As a result, vibration of the plate section during the operation of the railway vehicle is suppressed, and vibration noise (rolling noise) originating from the plate section is reduced. Therefore, noise generated from the wheels during the operation of the railway vehicle can be effectively reduced.

[0013] In the first configuration, the rigidity of the plate section is efficiently increased by giving the plate section its maximum thickness at a specific position, thereby reducing noise generated from the wheels when the railway vehicle is running. Therefore, there is no need to add other parts to the wheels for the purpose of noise reduction. According to the first configuration, noise generated from the wheels when the railway vehicle is running can be effectively reduced without using additional parts.

[0014] In the wheel according to the first configuration, the plate portion has a curved shape. In this case, the rigidity of the plate portion can be ensured when the wheel passes through a curved section of the rail.

[0015] In the first configuration, the base of the thickened region may be provided with a corner radius that is continuous with other regions (second configuration).

[0016] In the second configuration, the thickened area of ​​the plate body is connected to other areas via a corner radius. That is, there are no sharp corners at the boundary between the thickened area and other areas, and the thickened area is gently connected to other areas. As a result, the airflow is less disturbed at the boundary between the thickened area and other areas, and aerodynamic noise generated when railway vehicles are running can be reduced.

[0017] In the first or second configuration, the thickness of the plate body may vary continuously along the radial direction (third configuration).

[0018] In the third configuration, the thickness of the plate body changes continuously along the radial direction of the wheel, and there are no points where the thickness changes abruptly throughout the entire plate body. As a result, the airflow around the plate is less disturbed when the railway vehicle is running, and aerodynamic noise can be reduced.

[0019] In any of the first to third configurations, the length along the radial direction of the thickened area may be 0.47X or greater (fourth configuration).

[0020] In the fourth configuration, a length of 0.47X or more along the radial direction of the thickened area is ensured. This makes it easier to further reduce vibration noise originating from the plate section, and more effectively reduces noise generated from the wheels when the railway vehicle is running.

[0021] Embodiments of this disclosure will be described below with reference to the drawings. In each drawing, the same or equivalent components are denoted by the same reference numerals, and the same description will not be repeated.

[0022] [Wheel configuration] Figure 1 is a longitudinal cross-sectional view of a wheel 100 for a railway vehicle according to this embodiment. The longitudinal cross-section of the wheel 100 refers to the cross-section of the wheel 100 that includes the central axis A. Since the longitudinal cross-section of the wheel 100 is symmetrical with respect to the central axis A, Figure 1 shows only one side of the longitudinal cross-section of the wheel 100 with respect to the central axis A. In this embodiment, the direction in which the central axis A of the wheel 100 extends is called the axial direction. Also, in this embodiment, the radial direction of the wheel 100 is sometimes simply called the radial direction.

[0023] Referring to Figure 1, the wheel 100 comprises a boss portion 10, a rim portion 20, and a plate portion 30.

[0024] The boss portion 10 constitutes the inner circumference of the wheel 100. The boss portion 10 has a cylindrical shape with the central axis A as its axis. The axle of a railway vehicle (not shown) is inserted into the boss portion 10.

[0025] The boss portion 10 includes an inner circumferential surface 11, end faces 121 and 122, and an outer circumferential surface 13. Viewed in a longitudinal section of the wheel 100, the inner circumferential surface 11 extends in the axial direction. The outer circumferential surface 13 is positioned radially outward relative to the inner circumferential surface 11. The end faces 121 and 122 connect the inner circumferential surface 11 and the outer circumferential surface 13.

[0026] The rim portion 20 is positioned radially outside the boss portion 10. The rim portion 20 constitutes the outer circumference of the wheel 100. The rim portion 20 includes an outer circumference surface 21, side surfaces 221, 222, and an inner circumference surface 23.

[0027] The outer circumferential surface 21 includes the tread surface 211 and the surface of the flange 212. The tread surface 211 is the surface that contacts the top surface of the rail on which the railway vehicle runs. The surface of the flange 212 is provided continuously with one end of the tread surface 211 in the axial direction of the wheel 100. The flange 212 protrudes radially outward from the tread surface 211. When the railway vehicle runs on the rail, the flange 212 is positioned on the inside of the rail in the track width direction. Hereinafter, the side of the wheel 100 closer to the flange 212 in the axial direction will be called the flange side, and the side further from the flange 212 in the axial direction will be called the anti-flange side.

[0028] In this embodiment, the rim portion 20 is positioned outward in the raceway width direction relative to the boss portion 10. More specifically, the rim width center Cr is located on the opposite side of the flange relative to the boss width center Cb. However, the rim width center Cr may be located on the flange side relative to the boss width center Cb. Alternatively, the axial positions of the rim width center Cr and the boss width center Cb may substantially coincide. The rim width center Cr is the center of the rim portion 20 in the axial direction of the wheel 100. The boss width center Cb is the center of the boss portion 10 in the axial direction of the wheel 100.

[0029] The inner circumferential surface 23 is positioned radially inward relative to the outer circumferential surface 21. Side surface 221 connects the outer circumferential surface 21 and the inner circumferential surface 23 on the flange side. Side surface 222 connects the outer circumferential surface 21 and the inner circumferential surface 23 on the opposite side of the flange.

[0030] The plate portion 30 is positioned between the boss portion 10 and the rim portion 20. The plate portion 30 connects the boss portion 10 and the rim portion 20. The plate portion 30 is integrally formed with the boss portion 10 and the rim portion 20. The plate portion 30 is annular and has an axisymmetric shape with respect to the central axis A. The boss portion 10 and the rim portion 20 also have an axisymmetric shape with respect to the central axis A. That is, the shape of the cross-section of the boss portion 10, the rim portion 20, and the plate portion 30 along the radial direction is constant over the entire circumference of the wheel 100.

[0031] The plate portion 30 includes connecting portions 31 and 32 and the main body of the plate portion 33.

[0032] The connecting portion 31 is adjacent to the boss portion 10. The connecting portion 31 is positioned between the boss portion 10 and the plate portion body 33. The connecting portion 31 connects the plate portion body 33 to the boss portion 10. In a longitudinal cross-sectional view of the wheel 100, the connecting portion 31 is formed to widen toward the boss portion 10. In other words, the axial distance between the two sides 311 and 312 of the connecting portion 31 is greater on the boss portion 10 side and smaller on the plate portion body 33 side. In a longitudinal cross-sectional view of the wheel 100, the sides 311 and 312 have, for example, a concave curve on the inside of the wheel 100. The sides 311 and 312 extend toward the boss portion 10 while being axially separated from each other. The sides 311 and 312 are smoothly connected to the surface of the boss portion 10. The connecting portion 31 is a fillet portion that connects the plate portion 30 to the boss portion 10.

[0033] The connecting portion 32 is adjacent to the rim portion 20. The connecting portion 32 is positioned between the rim portion 20 and the plate portion body 33. The connecting portion 32 connects the plate portion body 33 to the rim portion 20. In a longitudinal cross-sectional view of the wheel 100, the connecting portion 32 is formed to widen toward the rim portion 20. In other words, the axial distance between the two sides 321 and 322 of the connecting portion 32 is greater on the rim portion 20 side and smaller on the plate portion body 33 side. In a longitudinal cross-sectional view of the wheel 100, the sides 321 and 322 have, for example, a concave curve on the inside of the wheel 100. The sides 321 and 322 extend toward the rim portion 20 while being axially separated from each other. The sides 321 and 322 are smoothly connected to the surface of the rim portion 20. The connecting portion 32 is a fillet portion that connects the plate portion 30 to the rim portion 20.

[0034] The plate body 33 has a curved shape when viewed in the longitudinal cross-section of the wheel 100. In this embodiment, the plate body 33 is curved convexly toward the flange side on the boss portion 10 side and convexly toward the opposite flange side on the rim portion 20 side. However, the curved shape of the plate body 33 is not limited to the example shown in this embodiment.

[0035] The plate body 33 is positioned between the connecting portion 31 and the connecting portion 32. The sides 331 and 332 of the plate body 33 are continuous with the sides 311 and 312 of the connecting portion 31 on the boss portion 10 side, respectively. The sides 331 and 332 of the plate body 33 are also continuous with the sides 321 and 322 of the connecting portion 32 on the rim portion 20 side, respectively. An inflection point exists between at least one of the sides 331 and 332 of the plate body 33 and the surface of the connecting portion 31 on the boss portion 10 side. An inflection point also exists between at least one of the sides 331 and 332 of the plate body 33 and the surface of the connecting portion 32 on the rim portion 20 side.

[0036] The plate body 33 includes a thickened region 333. The thickened region 333 is a region of the plate body 33 that has a greater plate thickness compared to other regions 334. The other regions 334 may be provided on both sides of the thickened region 333. That is, in the plate body 33, the plate thickness of the region between the inner and outer regions may be greater than the plate thickness of the inner and outer regions. The other regions 334 may be provided only on the inner side or only on the outer side of the thickened region 333. In this case, the thickened region 333 is adjacent to either the connection portion 31 on the boss portion 10 side or the connection portion 32 on the rim portion 20 side. The plate thickness of the plate body 33 is the distance between the side surfaces 331 and 332 along the normal direction of the side surface 331 or side surface 332.

[0037] Figure 2 is an enlarged view of the plate portion 30 of the wheel 100 shown in Figure 1. Referring to Figure 2, in the thickened region 333, one of the sides 331 and 332 bulges outward from the main body of the plate portion 33. In other words, when a virtual line VL substantially parallel to one of the sides 331 and 332 is drawn in the longitudinal section of the wheel 100 so as to be continuous with the connecting portions 31 and 32, in the thickened region 333, the other side 331 and 332 is positioned outside of the virtual line VL. The virtual line VL is the contour line of the main body of the plate portion 33 in the longitudinal section of the wheel 100, assuming that the plate thickness of the main body of the plate portion 33 is substantially constant. Figure 2 shows an example in which a virtual line VL is drawn substantially parallel to the side 332 on the non-flange side of the main body of the plate portion 33 and continuous with the sides 311 and 321 of the connecting portions 31 and 32. In Figure 2, in the thickened region 333, the flange-side surface 331 of the plate body 33 is positioned outside the imaginary line VL. In this embodiment, in the thickened region 333, the flange-side surface 331 is not symmetrical with the non-flange-side surface 332. In this example, in the thickened region 333, the surface 331 that bulges outward in the thickness direction of the plate body 33 is curved overall, and the curvature of this surface 331 is greater than the curvature of the other surface 332. As a result, the surfaces 331 and 332 are asymmetrical in the thickened region 333, and the plate thickness of the thickened region 333 is increased compared to the other regions 334. However, the plate body 33 may be provided with the thickened region 333 such that the flange-side surface 331 and the non-flange-side surface 332 are substantially symmetrical.

[0038] The main body of the plate section 33 has a maximum plate thickness t in the thickened region 333. max It has a minimum plate thickness t in other regions 334. min It has a minimum plate thickness t. min The region 334 having this characteristic is located on one or both sides of the thickened region 333. Minimum plate thickness t min If the region 334 having the above exists on the outer circumference side of the thickened region 333, the plate body 33 has a minimum plate thickness t at the boundary (inflection point) B2 with the connecting portion 32 on the rim portion 20 side, or slightly on the inner circumference side of boundary B2. min It can have a minimum plate thickness t. minWhen the region 334 having it exists on the inner peripheral side of the build-up region 333, the plate body 33 has a minimum plate thickness t at the boundary (inflection point) B1 with the connecting portion 31 on the boss portion 10 side, or slightly on the outer peripheral side than the boundary B1. min can have. The maximum plate thickness t max and the minimum plate thickness t min The difference from is, for example, 3 mm or more.

[0039] In the connecting portions 31 and 32 adjacent to the plate body 33, there is a portion having a plate thickness t0 that is twice the minimum plate thickness t min . The plate thickness of the connecting portion 31 is the distance along the axial direction between the side surfaces 311 and 312, and the plate thickness of the connecting portion 32 is the distance along the axial direction between the side surfaces 321 and 322. For the plate portion 30, the portion having a plate thickness t0 that is twice the minimum plate thickness t min of the plate body 33 in the connecting portion 31 is defined as the inner peripheral end E1, and the portion having a plate thickness t0 that is twice the minimum plate thickness t min of the plate body 33 in the connecting portion 32 is defined as the outer peripheral end E2. Then, the distance along the radial direction from the inner peripheral end E1 to the outer peripheral end E2 is defined as the length X of the plate portion 30.

[0040] The build-up region 333 has the maximum plate thickness t at a position 0.40X or more and 0.68X or less radially outward from the inner peripheral end E1 of the plate portion 30. max For example, when the side surface 331 or the side surface 332 of the plate body 33 bulges in a substantially arc shape in a longitudinal sectional view in the build-up region 333 as compared with other regions 334, the normal direction distance between the side surfaces 331 and 332 at the position of the apex of this bulging portion is the maximum plate thickness t max , and the apex of the bulging portion is positioned in the range of 0.40X or more and 0.68X or less radially outward from the inner peripheral end E1 of the plate portion 30. For example, in a longitudinal sectional view of the wheel 100, when the portion having the maximum plate thickness t max extends along the plate body 33, the center in the extending direction of this section is positioned in the range of 0.40X or more and 0.68X or less radially outward from the inner peripheral end E1 of the plate portion 30. The build-up region 333 preferably has the maximum plate thickness t at a position 0.50X or more radially outward from the inner peripheral end E1 of the plate portion 30, and at a position 0.60X or more, the maximum plate thickness t max has, and at a position 0.60X or more, the maximum plate thickness t maxIt is more preferable to have it.

[0041] The length Y of the thickened region 333 along the radial direction is preferably 0.47X or more. The length Y of the thickened region 333 is, for example, 0.90X or less. The length Y of the thickened region 333 is the length along the radial direction of the portion of the plate body 33 where the side surface 331 or side surface 332 is located outside the imaginary line VL. In the plate body 33, it is preferable that a corner R portion 335 continuous with another region 334 is provided at the base of the thickened region 333. In the example shown in Figure 2, a corner R portion 335 is provided at the base of the portion that bulges out from the imaginary line VL on one side surface 331 of the plate body 33. The corner R portion 335 may be provided at the bases on both sides of the thickened region 333, or at the base on one side.

[0042] As described above, the plate body 33 is provided with a thickened region 333. Therefore, the thickness of the plate body 33 is not constant throughout. The thickness of the plate body 33 changes along the radial direction of the wheel 100. It is preferable that the thickness of the plate body 33 changes continuously along the radial direction of the wheel 100. In order to continuously change the thickness of the plate body 33, the sides 331 and 332 of the plate body 33 can be made into a smooth shape in which the corners are not substantially visible. More specifically, for example, if each of the sides 331 and 332 contains multiple types of curves, the rate of change of the radius of curvature between adjacent curves can be made 1500% or less. This makes the sides 331 and 332 into a smooth shape, and allows the thickness of the plate body 33 to change continuously. If the sides 331 and 332 contain straight lines, it is preferable that these straight lines are tangent to the adjacent curves.

[0043] [effect] In the wheel 100 according to this embodiment, the rigidity of the plate portion 30, which is the main source of noise, is increased compared to conventional wheels by partially increasing the thickness of the plate portion body 33. More specifically, a thickened region 333 is provided in the plate portion body 33, and the length along the radial direction of the plate portion 30 is X, the end of the plate portion 30 on the boss portion 10 side (inner circumference end) E1 is 0, and the end of the plate portion 30 on the rim portion 20 side (outer circumference end) E2 is 1, and the plate portion body 33 has a maximum plate thickness t at a position between 0.40X and 0.68X. max This allows for easier suppression of vibrations of the plate portion 30 during the operation of the railway vehicle, thereby reducing vibration noise (rolling noise) originating from the plate portion 30. Consequently, noise generated from the wheels 100 during the operation of the railway vehicle can be effectively reduced.

[0044] In this embodiment, the length Y along the radial direction of the thickened region 333 is preferably 0.47X or more. This further reduces vibration noise originating from the plate portion 30, and more effectively reduces noise generated from the wheels 100 when the railway vehicle is running.

[0045] In this embodiment, the plate body 33 has a maximum plate thickness t at a specific position. max By providing this feature, the rigidity of the plate portion 30 is efficiently increased, reducing the noise generated from the wheel 100 when the railway vehicle is running. Therefore, there is no need to add other parts to the wheel 100 for the purpose of noise reduction. In other words, according to the wheel 100 of this embodiment, noise can be effectively reduced when the railway vehicle is running without using additional parts. Such a wheel 100 can be manufactured, for example, by forging, casting, or machining (cutting) of a forged or cast product. The material of the wheel 100 is preferably carbon steel.

[0046] In this embodiment, the plate portion body 33 has a curved shape when viewed in a longitudinal cross-section of the wheel 100. In this case, the rigidity of the plate portion 30 can be ensured when the wheel 100 passes through a curved section of the rail.

[0047] In this embodiment, the thickened region 333 of the plate body 33 is connected to other regions 334 via a corner radius 335. That is, there are no sharp corners at the boundary between the thickened region 333 and other regions 334, and the thickened region 333 is gently connected to other regions 334. As a result, the airflow around the thickened region 333 is less disturbed, and aerodynamic noise generated when a railway vehicle is running can be reduced.

[0048] In this embodiment, it is preferable that the thickness of the plate body 33 changes continuously along the radial direction of the wheel 100. That is, it is preferable that there are no locations where the thickness changes abruptly throughout the entire plate body 33. This makes it less likely for the airflow around the plate 30 to be disturbed when the railway vehicle is running, and aerodynamic noise can be reduced.

[0049] For example, if the thickened area 333 is to be rectangular in shape when viewed in a longitudinal section of the wheel 100, it is necessary to machine the plate body 33 to form the thickened area 333. However, if the plate thickness of the plate body 33 is to be continuously varied along the radial direction of the wheel 100, and the thickened area 333 is to be made into a gentle shape, the wheel 100 including the thickened area 333 can be manufactured, for example, by forging. In this case, machining for the thickened area 333 is unnecessary, and the manufacturing cost of the wheel 100 can be reduced.

[0050] While embodiments relating to this disclosure have been described above, this disclosure is not limited to the embodiments described above, and various modifications are possible as long as they do not deviate from its spirit. [Examples]

[0051] The present disclosure will be further described below with reference to examples. However, the present disclosure is not limited to the following examples.

[0052] To verify the effects of this disclosure, a finite element analysis was performed using general-purpose structural analysis software to evaluate the quietness of the wheel. In this analysis, a force simulating rail reaction force was applied to the tread of a 360° wheel model, and the response to vibration at that time was evaluated as quietness. The equivalent radiated power (ERP) obtained by the following formula was used to evaluate the quietness.

[0053]

number

[0054] In the above formula, ΔS i V is the element area of ​​the wheel surface. ni is the vibration velocity in the direction normal to the surface. c is a coefficient determined by atmospheric conditions, etc. A larger ERP indicates a higher ability to radiate sound.

[0055] Figures 3, 4, and 5 show the external shapes of wheels according to Comparative Example 1, Comparative Example 2, and Comparative Example 3, respectively. In Comparative Example 1 shown in Figure 3, the thickness of the plate body 33 is substantially constant throughout. The plate body 33 of Comparative Example 1 does not have a thickened area 333 (Figures 1 and 2). In Comparative Example 1, in a longitudinal cross-sectional view of the wheel, the sides 331 and 332 of the plate body 33 are substantially symmetrical across the entire surface.

[0056] Comparative Example 2, shown in Figure 4, corresponds to the wheel shown in Figure 2(a) of Patent Document 1. As shown in Figure 4, in Patent Document 1, the length L of the plate portion 30 is defined as the length along the radial direction from the end of the straight portion on the plate portion 30 side of the end face 122 on the opposite side of the boss portion 10 to the end of the straight portion on the plate portion 30 side of the side surface 222 on the opposite side of the rim portion 20, and the position of the reinforced area (rigidity-increasing portion) 333 is determined based on this L. In Comparative Example 2, similar to Figure 2(a) of Patent Document 1, the reinforced area 333 is made continuous in the circumferential direction of the plate portion 30 to form an annular shape, and the inner circumferential edge of the reinforced area 333 is positioned 2L / 3 (0.67L) outward from the boss portion 10. The outer circumferential edge of the reinforced area 333 is positioned 30.0 mm outward from the inner circumferential edge.

[0057] Comparative Example 3, shown in Figure 5, corresponds to the wheel shown in Figure 2(b) of Patent Document 1. In Comparative Example 3, similar to Figure 2(b) of Patent Document 1, the inner circumferential edge of the thickened region 333 is positioned L / 3 (0.33L) outward from the boss portion 10, and the outer circumferential edge of the thickened region 333 is positioned 2L / 3 (0.67L) outward from the boss portion 10. In Comparative Example 3, similar to Figure 2(b) of Patent Document 1, three thickened regions 333 are arranged at equal intervals along the circumferential direction of the wheel.

[0058] Figures 6 to 11 show the external shapes of the wheels according to Examples 1 to 6, respectively. The weight of the wheels in Examples 1 to 6 was the same. In Examples 1 to 3, the length Y of the thickened region 333 is the same, but the maximum plate thickness t of the plate body 33 is the same. max The positions of the elements are different from each other. In Examples 4 to 6, the maximum plate thickness t of the plate body 33 is different. max The position is the same, but the length Y of the thickened region 333 is different from each other. In each of Examples 1 to 6, the maximum plate thickness t of the plate body 33 is max The position is the apex of the bulge provided on one side surface 331 of the main body of the plate portion 33, and the maximum plate thickness t max This is the length along the direction perpendicular to the tangent to the vertex (normal direction) from this vertex to the other side surface 332.

[0059] The conditions for each wheel are shown in Table 1.

[0060] [Table 1]

[0061] Table 1 shows the total energy amount (OAERP level) of the plate portion 30 at all frequencies for each comparative example and each example, as the difference compared to Comparative Example 1. A positive OAERP level value means that the quietness of the plate portion 30 has improved compared to Comparative Example 1, and a negative OAERP level value means that the quietness of the plate portion 30 has decreased compared to Comparative Example 1. For Comparative Examples 2 and 3, the length Y of the thickened region 333 was calculated using the value of X, which was determined in the same manner as in Examples 1 to 6.

[0062] As shown in Table 1, in Examples 1 to 6, the maximum plate thickness t of the plate portion 33 is at a position that is 0.40 to 0.68 times the length X along the radial direction of the plate portion 30 from the inner circumferential end E1 of the plate portion 30 toward the outer circumferential end. max The quietness of the plate portion 30 was improved in all of Examples 1 to 6 compared to Comparative Example 1. In Comparative Example 2, the quietness of the plate portion 30 was also improved compared to Comparative Example 1, but the degree of improvement in quietness was smaller than in Examples 1 to 6. In Comparative Example 3, the quietness of the plate portion 30 was lower than in Comparative Example 1.

[0063] Therefore, when a thickened area 333 is provided around the entire circumference of the plate body 33, the maximum plate thickness t of the thickened area 333 is max When the position is 0.40X to 0.68X outward from the inner circumferential end E1 of the plate portion 30, noise originating from the plate portion 30 during the operation of the railway vehicle is effectively reduced, and it can be said that better quietness than before can be achieved.

[0064] Examples 4 to 6 show the maximum plate thickness t of the plate body 33. max The position is the same as in Example 2, but the length Y of the thickened region 333 is different from Example 2. To verify the effect based on the length Y of the thickened region 333, Example 2 was compared with Examples 4 to 6.

[0065] The weight of the wheels in Example 2 and Examples 4 to 6 is the same, and the length Y of the thickened region 333 in Example 2 is wider than the length Y of the thickened region 333 in Examples 4 to 6. Therefore, in Example 2, the change in the thickness of the plate body 33 along the radial direction is more gradual compared to Examples 4 to 6. As shown in Table 1, the quietness of the plate 30 was improved in Example 2 compared to Examples 4 to 6.

[0066] Therefore, by ensuring a wide length Y of the thickened region 333, noise originating from the plate portion 30 becomes easier to reduce, and the quietness of the wheel is further improved. Based on the results of Example 2, it is preferable that the length Y of the thickened region 333 is 0.47X or more. [Explanation of Symbols]

[0067] 100: Wheels 10: Boss Section 20: Rim section 30: Board part 31,32: Connection part 33: Main body of the board 333: Thickening area 334: Other areas 335: Corner radius E1: Inner edge E2: Outer edge

Claims

1. Wheels for railway vehicles, A cylindrical boss section, A rim portion is positioned outside the boss portion in the radial direction of the wheel, A plate portion is positioned between the boss portion and the rim portion and has a shape symmetrical with respect to the central axis of the boss portion, Equipped with, The aforementioned plate portion is A plate body having a curved shape when viewed in cross-section including the central axis, A first connecting portion is positioned between the boss portion and the plate portion body, and connects the plate portion body to the boss portion. A second connecting portion is positioned between the rim portion and the plate portion body, and connects the plate portion body to the rim portion. Includes, The plate portion body includes a thickened region where the plate thickness is greater than in other regions of the plate portion body, and has the maximum plate thickness in the thickened region and the minimum plate thickness in the other regions. A wheel wherein the portion of the first connecting portion having a thickness twice the minimum plate thickness is defined as the inner circumferential end of the plate portion, and the portion of the second connecting portion having a thickness twice the minimum plate thickness is defined as the outer circumferential end of the plate portion, and when the distance along the radial direction from the inner circumferential end to the outer circumferential end is X, the thickened region has the maximum plate thickness at a position of 0.40X or more and 0.68X or less radially outward from the inner circumferential end.

2. A wheel according to claim 1, A wheel, wherein the base of the thickened region is provided with a corner radius that is continuous with the other region.

3. A wheel according to claim 1, The thickness of the plate body of the wheel changes continuously along the radial direction.

4. A wheel according to any one of claims 1 to 3, A wheel in which the length of the thickened region along the radial direction is 0.47X or more.

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