The name of the invention: railway wheel with brake disk
Technical field
[0001]
　The present invention is a brake disc with railway wheel brake disc to the wheel for a railway vehicle, which are fastened (hereinafter, simply referred to as "BD-conditioned railroad wheel") relates.
Background technique
[0002]
　The brake system of the railway vehicle, along with the speed and the size of the vehicle, excellent disc brake in braking performance is often used. Disc brake is configured to press the brake linings on the sliding surface of the brake disc attached to a wheel. Accordingly, the braking force is generated in rotating the wheel, the speed of the vehicle is controlled.
[0003]
　The disk brake, to conclude with the central conclusion type (sliding surface concluded type) brake disc for fastening the brake disc to the wheel in the area of ​​the sliding surface, the break disk on the side of the inner periphery of the area than the sliding surface on the wheel there is the inner circumferential conclusion type brake disk. The inner peripheral engagement type brake disc requires a portion to be used separately from the fastening to the portion having a sliding surface. On the other hand, the central fastening type brake disc, there is no need to provide the portion used for such engagement, which is advantageous for weight reduction.
[0004]
　1A and 1B are views showing the overall structure of a brake disk with railway wheels constituting a disc brake of a railway vehicle, a plan view of FIG. 1A quadrant portion, FIG 1B is a semicircular portion It shows a cross-sectional view along the radial direction, respectively. Figures 2A ~ 2C are a structure of a conventional BD with railway wheels a view showing locally, Figure 2A is a perspective view of the reverse side of the brake disc from the inner peripheral surface side, FIG. 2B is a brake disc the plan view seen from the back side, FIG. 2C shows a cross-sectional view taken along the radial direction, respectively. 1A, the brake disc illustrated in FIGS. 1B and. 2A ~ 2C are both a central fastening type.
[0005]
　Figure 1A, as shown in FIGS. 1B and. 2A ~ Fig 2C, the brake disc 1 includes a disc portion 2 of the toroidal to the surface 2a side sliding surface. On the back surface 2b of the disc portion 2, a plurality of fin portions 3 are projected radially. The some of the plurality of fin portions 3, a substantially central position in the radial direction, the bolt holes 4 penetrate to the disc portion 2 is formed.
[0006]
　Wheel 10 is provided with a plate portion 13 which binds the rim portion 12, and these include a tread axle in contact with boss portion 11, the rail being pressed. Brake disc 1, two in a state where the individual surface 2a and outwardly as a set, are arranged so as to sandwich the plate portion 13 of the wheel 10. Bolt 5 to each bolt hole 4 is inserted, the nut 6 is tightened screwed to each bolt 5. Accordingly, the brake disk 1, the distal end surface of the fin 3 is pressed against the side surface 13a of the plate portion 13 of the wheel 10 in the radial direction throughout or part of the area thereof, it is fastened to the wheel 10 in this state.
[0007]
　Brake disc 1 is fastened to the plate portion 13 in the region of the sliding surface. The central fastening type brake disk, in the radial direction of the brake disc 1, the central portion near the inner circumference and the outer circumference of the brake disc 1, for example, the inner and outer peripheries 1: position which internally divides at 3 and 3: 1 between a position which internally divides, it is preferable that the brake disc 1 is fastened to the wheel 10.
[0008]
　Has become substantially the entire surface of the brake disk 1 and the sliding surface, as shown in FIG. 1B, is provided between the boss portion 11 and the disc portion 2, a large gap over the entire circumference (for example, gap 70 ~ 120mm) is formed. That is, the brake disk 1, the boss portion 11 to the vicinity does not extend, thereby, the weight of the brake disk 1 is achieved. Conventional BD with railway wheels of such a construction is disclosed, for example, in Patent Document 1.
[0009]
　During the running of the railway vehicle, the brake disk 1 is rotated at a high speed integrally with the wheel 10. Along with this, the air surrounding the brake disc 1, in a space formed between the brake disc 1 and the wheel 10, in particular, the disc portion 2 and fins 3 of the brake disc 1, and the wheels in a space surrounded by 10 of the plate portion 13, the inner circumferential side to flow from (the gap between the boss 11 and the disc portion 2), and flows out from the outer peripheral side (see the solid line arrow in FIG. 2A ~ Figure 2C) . In short, during the running of the railway vehicle, the space between the brake disk 1 and the wheel 10 caused a gas flow of air. This gas flow, will significantly when traveling at a high speed of more than 300km per hour as high-speed railway vehicle such as a bullet train (R), to induce the noise of the wind noise. The wind noise is referred to as the aerodynamic sound. Reduction of aerodynamic noise from the consideration of the environment is needed.
[0010]
　The inner circumferential fastening type brake disk, a gap between the boss portion 11 and the circular plate portion 2 relative to the center fastening-type brake disk is significantly smaller. Therefore, during running of the vehicle, the amount of air flowing from the gap, the disc portion 2 and fins 3 of the brake disc 1, and the space enclosed by the plate portion 13 of the wheel 10 is small, Usually, there is no aerodynamic sound level in question. Therefore, generation of aerodynamic sound, it can be said that the central conclusion type brake disk-specific problem.
[0011]
　Prior art corresponding to the request to reduce the aerodynamic noise about the central conclusion type brake disc is the following.
[0012]
　For example, Patent Document 2, for brake disks, add the ribs along the circumferential direction between the fin portions adjacent to each other, BD with railway wheel with reduced gas stream is disclosed by this rib. According to BD with railway wheels disclosed in the document, it is possible to reduce aerodynamic noise to the desired level.
[0013]
　However, said technique disclosed in Patent Document 2, with the suppression of the gas flow due to the ribs, the cooling performance of the brake disc is reduced during braking. Therefore, coupled with the rigidity of the brake disc itself is increased by the addition of ribs, deformation due to thermal expansion of the brake disk, and it due to stress load is increased to the fastening bolt, the durability of the brake disc and the bolt is reduced there is a risk of.
[0014]
　Prior art attempt to resolve this problem is disclosed in US Pat.
[0015]
　3A and 3B are views showing a structure of a conventional BD with railway wheels disclosed in Patent Document 3 topically, 3A is a perspective view of the reverse side of the brake disc from the inner peripheral surface side FIG 3B is a sectional view taken along the radial direction, respectively. As shown in these drawings, in the BD-conditioned railroad wheel disclosed in Patent Document 3, for a brake disc 1, add the ribs 7 in the circumferential direction between the fin portions 3 adjacent to each other, further, this slit 7a is formed along the radial direction in the center portion of the circumferential ribs 7.
[0016]
　According to the BD with railway wheels, gas flow is ensured by the slit 7a. Therefore, when together with the cooling performance is maintained to the brake disc 1 to brake, since the increase in rigidity due to the addition of the ribs is relaxed, the stress load on the deformation and fastening bolts due to thermal expansion of the brake disk 1 is reduced, reduction in the durability of the brake disc 1 and the bolt is suppressed.
CITATION
Patent literature
[0017]
Patent Document 1: JP 2006-9862 JP
Patent Document 2: Japanese Unexamined Patent Publication No. 2007-205428
Patent Document 3: International Publication WO2010 / 071169 pamphlet
Summary of the invention
Problems that the Invention is to Solve
[0018]
　As mentioned above, the conventional BD with railway wheels to reduce aerodynamic noise is to disc portion and fin portion of the brake disc, and surrounded by a plate portion of the wheel to suppress the gas flow in the space focus , add ribs to the circular plate portion of the disc brake, and further forming a slit on the rib. Therefore, since the shape of the brake discs is complicated, the productivity of the brake disc decreases inevitably.
[0019]
　Specifically, not only the fin portion, additional processing to adjust the height of the rib (machining or the like) is required, further, because the additional processing to form the slits in the rib becomes necessary, the manufacture of the brake disc process is complicated. Especially, when manufacturing a brake disk by forging load to the mold is increased, it is undeniable that the mold life is shortened.
[0020]
　The present invention has been made in view of the above problems, and its object is to provide a railway wheel with a brake disc having the following characteristics:
　while suppressing aerodynamic noise during high speed running, the brake disc it is excellent in productivity in a simple shape.
Means for Solving the Problems
[0021]
　Railway with a brake disc wheel according to an embodiment of the present invention,
　the boss portion, a rim portion, and a wheel for a railway vehicle having a plate portion connecting them,
　circle toroidal which the surface-side sliding surface the plate portion, and provided with a brake disc having a plurality of fin portions which project radially on the back surface of the disc portion,
　the state in which two of the brake disc has an individual said sliding surface outwardly in sandwiching the plate portion of the wheel, a train wheel with a brake disc fastened in the region of the said sliding surface,
　along a space formed between said brake disc the wheel in the circumferential direction the area of a cross-section transverse on, minimum cross section which minimizes this cross-sectional area, wherein the disc portion of the areas formed by the inner peripheral surface of the rim portion and the outer peripheral surface of the circular plate portion present in the most rear side of the outer peripheral surface,
　the area of the minimum cross-sectional portion is 2500 mm 2 or more, 7000 mm 2 or less.
[0022]
　Area of the smallest cross-sectional section, 3000 mm 2 is preferably at least.
　Additional BD with railway wheels may be an outer diameter of the disc portion is configured to be constant.
Effect of the invention
[0023]
　Railway wheel with brake discs of the present invention have a remarkable effect of the following:
　while suppressing aerodynamic noise during high speed running, it brake disc is excellent in productivity in a simple shape.
Brief description of the drawings
[0024]
[Figure 1A] Figure 1A is a diagram showing the overall structure of a railway wheel with a brake disc, a plan view of 1/4 yen moiety.
[FIG 1B] Figure 1B is a diagram showing the overall structure of a railway wheel with a brake disk, a sectional view taken along the radial direction of the semicircular portion.
[Figure 2A] Figure 2A is the structure of a conventional brake disc with railway wheels a view showing locally shows a perspective view from the inner peripheral surface side of the back surface of the brake disc.
[Figure 2B] Figure 2B is the structure of a conventional railroad wheel with brake discs a view showing locally shows a plan view of the brake disc from the back side.
[FIG 2C] FIG 2C is a structure of a conventional brake disc with railway wheels a view showing locally, a sectional view taken along the radial direction.
[Figure 3A] Figure 3A is a diagram showing a structure of a conventional railway wheeled brake disc disclosed in Patent Document 3 locally shows a perspective view from the inner peripheral surface side of the back surface of the brake disc .
[Figure 3B] Figure 3B is a diagram showing a structure of a conventional railway wheeled brake disc disclosed in Patent Document 3 locally, a sectional view taken along the radial direction.
[4] FIG 4 is a diagram showing the correlation between the sum and the aerodynamic sound level and venting of the opening area of the railway wheel with brake discs.
[Figure 5A] Figure 5A is a cross-sectional view showing the structure of a railway wheel with brake discs, along the radial direction is an embodiment of the present invention.
[Figure 5B] Figure 5B is a sectional view showing locally railway wheel with brake discs of Figure 5A, it shows a rectangular area in Figure 5A.
[Figure 6A] Figure 6A shows the structure of a railway wheel with a brake disc using a comparative embodiment in the analysis is a sectional view taken along the radial direction.
[Figure 6B] Figure 6B is a cross-sectional view showing locally railway wheel with brake discs of Figure 6A, it shows a rectangular area in Figure 6A.
[7] FIG. 7 is a diagram showing the correlation between the area and the aerodynamic sound level and venting of the space cross-section at the minimum cross section of a railway wheel with brake discs.
FIG. 8 is disclosed in Patent Document 3 is a diagram showing the relationship between the 1/3-octave band processing was performed center frequency and noise level.
DESCRIPTION OF THE INVENTION
[0025]
　As described in the Patent Document 3, which is formed between the brake disc and the wheel space, the disc portion and the fin portions of the brake disc Among them, as well as the air flowing through the space surrounded by the plate portion of the wheel between the aeration rate, the level of aerodynamic noise, there is a strong correlation.
[0026]
　Figure 4 is a diagram showing the correlation between the sum and the aerodynamic sound level and venting of the opening area of ​​the railway wheel with brake discs. Here, the total opening area refers, disc portion and fin portion of the brake disc, as well as the space surrounded by the plate portion of the wheel, the circumferential entire area of ​​the opening area when viewed from the inner periphery of the brake disc is that the sum over. Minimum In other words, the total opening area, section transverse along a space formed between the brake disc and the wheel in the circumferential direction (hereinafter, "spatial cross-section") will, in the area of ​​the space cross-section it is that the area of ​​the minimum cross section to be. For example, FIG. 3A and as a BD with railway wheel shown in FIG. 3B, is added ribs between the adjacent fin parts of the brake disc, if the slits are formed in the ribs, the minimum cross section position of the rib since the area of ​​the spatial cross-section at the position of the rib is the sum of the opening areas shown in FIG. It should be noted that the amount of aeration is obtained by the thermal fluid analysis (per sheet brake disk), the level of aerodynamic noise are those obtained by experiment.
[0027]
　As shown in FIG. 4, aerodynamic noise level increases with the increase of the area of ​​the minimum cross section (the sum of the opening area), aeration amount seen that the same tendency. In other words, there is a strong correlation between the amount of aeration and the aerodynamic sound level. For this reason, the evaluation of the aerodynamic noise level can be carried out in the aeration rate as an indicator, ventilation amount of suppression leads to suppression of aerodynamic sound. And, in order to suppress the amount of aeration, it is sufficient to properly define the area of ​​the minimum cross section of the space cross-section.
[0028]
　In this respect, in the above patent conventional BD with railway wheel shown in Documents 2 and 3, the disc portion and the fin portions of the brake disc, and focused in a space surrounded by the plate portion of the wheel, the space cross-section in this space place the minimum cross section in order to limit the gas flow, add ribs to the circular plate portion of the disc brake, it is further formed a slit in the ribs. Due to this, the above-mentioned problem becomes apparent.
[0029]
　Accordingly, the present inventors, in order to solve the above problems, among spaces formed between the brake disc and the wheel, the disc portion and the fins of the brake disc which has been focused in the prior art, and the wheel rather than surrounded by the plate portion space, the outer peripheral region of the disc portion of the brake disc, i.e. focusing is limited to the area formed by the inner peripheral surface of the rim portion of the outer peripheral surface and the wheels of the disc portion of the brake disc did. And the most back side of the outer peripheral surface of the circular plate portion on one of the limited regions (hereinafter, "rear surface portion of the disc portion outer peripheral surface") to place the minimum cross section of the space cross-section, a numerical value by thermal fluid analysis It was investigated aeration amount using the calculation. Knowledge of and the results, if properly define the area of ​​the spatial cross-section in the back part of the disc portion the outer peripheral surface of the smallest cross section and the brake disk, the amount of aeration and suppression in the prior art equivalent, it is possible to suppress the aerodynamic noise , which was to the completion of the present invention.
[0030]
　Described in detail in the following embodiment of the railway wheel with a brake disk of the present invention.
　Figure 5A is a cross-sectional view showing the structure of a railway wheel with brake discs, along the radial direction is an embodiment of the present invention. Figure 5B is a sectional view showing locally railway wheel with brake discs of Figure 5A, it shows a rectangular area in Figure 5A. Hereinafter, FIG. 1A, the same reference numerals are given to portions common to the conventional BD with railway wheels shown in FIGS. 1B and. 2A ~ Fig 2C, the redundant description will be omitted as appropriate.
[0031]
　As shown in FIGS. 5A and 5B, the brake disc 1 according to this embodiment includes a circular plate portion 2, and a fin portion 3. The brake disk 1 has no rib 7 as shown in FIG. 3A and 3B. In short, the back surface 2b of the disc portion 2, only a plurality of fin portions 3 are projected radially.
[0032]
　The material of the brake disc 1, it is possible to adopt cast iron, cast steel, forged steel, aluminum, carbon or the like.
[0033]
　Strictly speaking, the area where the sliding surface of the surface 2a of the brake disc 1 is one step higher. Brake disc 1, the sliding surface is worn with the braking of the repetition, the sliding surface of the wear progresses to the level of the surface 2a of the disc portion 2, is replaced.
[0034]
　Wheel 10 includes a boss portion 11, a rim portion 12, the plate portion 13. The inner circumferential surface 12b of the rim portion 12 includes corner surfaces 12ba leading to side 12a of the rim portion 12, and a fillet surface 12bb leading to the side surface 13a of the corner surface 12ba and the plate portion 13.
[0035]
　The shape of the corner surfaces 12ba and fillet surface 12bb is designed according to the specifications of the vehicle. For example, the corner surface 12ba is contour in cross section along the axial direction of the wheel 10 is a circular arc, a single R surface radius of curvature is constant. Fillet surface 12bb is contour in cross section along the axial direction of the wheel 10 is a shape combining straight lines and arcs, a composite surface truncated conical tapered surface and the curvature radius of a combination of certain R-plane is there. However, the fillet surface 12bb may be a single R-surface, or may be a free curved surface in which a curvature radius changes.
[0036]
　Here, the BD with the railway wheels of the present embodiment, the spatial cross-section traversing along a space formed between the brake disc 1 and the wheel 10 in the circumferential direction, and the minimum area of ​​the space cross-section the minimum cross section made are present in the area formed by the inner circumferential surface 12b of the rim portion 12 of the outer peripheral surface 2c and the wheel 10 of the disc portion 2 of the brake disc 1. More specifically, present in most back surface 2b side of the outer peripheral surface 2c of the disc portion 2 (see back side portion of the disk outer peripheral surface, labeled "a1" in FIG. 5B).
[0037]
　In order to realize this state, the back surface portion a1 of the disk portion outer peripheral surface 2c of the brake disk 1, closest to the inner peripheral surface 12b of the rim portion 12 of the wheel 10. For example, when the outside diameter of the disc portion 2 of the brake disc 1 of 715mm, a minimum gap g between the inner peripheral surface 12b of the bottom a1 and the rim portion 12 of the disc portion outer circumferential surface 2c is 1.3 1-3. it is about 1mm. The minimum gap g has a portion b1 to the extended line of the back surface 2b of the disc portion 2 intersects the inner circumferential surface 12b of the rim portion 12, which corresponds to the distance between the rear surface portion a1 of the disk portion outer peripheral surface 2c. The outer diameter of the circular plate portion 2 is preferably constant. This is because easily machined.
[0038]
　In particular, the BD with railway wheels of the present embodiment, the area of the spatial cross-section of the back surface portion a1 of the disk portion outer peripheral surface 2c, 2500 mm 2 or more, 7000 mm 2 or less. The area of the cross section, 3000 mm 2 is preferably at least. Such numerical ranges are derived from consideration based on the thermal fluid analysis and the analysis results below.
[0039]
[Thermal fluid analysis]
　For BD with railway wheel shown in FIG. 5A and 5B, the traveling speed to simulate the high-speed running is constant and 360km / h for thermal fluid analysis, with a minimum cross section of the space cross-section of it was evaluated aeration amount. At that time, by variously changing the minimum gap g between the inner peripheral surface 12b of the bottom a1 and the rim portion 12 of the disc portion outer circumferential surface 2c, the back surface portion of the disc portion outer circumferential surface 2c a1 (minimum cross section) the area of the spatial cross-section with various modified models.
[0040]
　In addition, for comparison, as shown in FIG. 6A and 6B, and the model of BD with railway wheels add a rib 7 with a slit 7a between the fin section 3 to each other, rib 7 with a slit 7a is provided not using a model of BD with railway wheels. BD with railway wheels shown in FIGS. 6A and 6B, the disclosed in Patent Document 3 a BD with railway wheels, that is the same as that of the conventional BD with railway wheel shown in FIG. 3A and 3B, the disc outer periphery minimum gap g between the inner circumferential surface 12b of the back portion a1 and the rim portion 12 of the surface 2c denotes larger. In which the rib 7 with a slit 7a of the model of the comparative form is provided is the minimum sectional portion of the spatial cross-section position of the fin 7, by variously changing the depth d of the slit 7a, the minimum cross-section the area of ​​the spatial cross-section of in parts made various changes. The present embodiment and the comparative form are both is obtained by central fastening the brake disc.
[0041]
　Table 1 below shows the conditions of the model of BD with railway wheels used for the analysis. Throughout the space formed between the brake disc 1 and the wheel 10, the area minimum cross section, in this embodiment, formed by the inner circumferential surface 12b of the outer peripheral surface 2c and the rim portion 12 of the disc portion 2 to have, in the comparative embodiment, it lies between the back surface 2b outer peripheral portion and the plate portion 13 of the disc portion 2 (which rib is provided with slits). It should be noted, by such as the presence of the fin section 3 between the disc portion 2 and the plate portion 13, the minimum cross section is unique in not determined from only a single cross-section of the BD with railway wheels.
[0042]
[Table 1]

[0043]
　Other typical conditions of the analysis model is as follows.

　Shinkansen (R) forged steel disk for the
　inner diameter of-circular disk: 417mm
　front end surface of the fin part from the sliding surface of,
　· diameter is formed at regular intervals twelve bolt hole position is centered on the same circle of 560mm, signed a brake disk and the wheel by inserting a bolt in each bolt hole.
[0044]

　rolling wheels for the Shinkansen (R)
　- inner diameter: 196mm, outer diameter: 860mm, rim portion of the radial thickness: 60mm
[0045]
[Analysis Results and Discussion]
　FIG. 7 is a diagram showing the correlation between the area and the aerodynamic sound level and venting of the space cross-section at the minimum cross section of a railway wheel with brake discs. Incidentally, aerodynamic sound level shown in the figure is the same as that shown in FIG. 4. Figure 7 is aerodynamic sound level of the BD with the railway wheel having an inner peripheral engagement type brake disc is indicated by broken lines.
[0046]
　As shown in FIG. 7, the relationship between the area and the ventilation of the space cross-section with a minimum cross section is consistent with the conventional BD with railway wheels of comparative form a BD with the railway wheels of the present embodiment. From this, it can be said that for the relationship of the aerodynamic noise level, consistent with conventional BD with railway wheels of the comparative form with BD with railway wheels of the present embodiment.
[0047]
　Aerodynamic noise level, as shown in FIG. 7 decreases with a decrease in the area of minimum cross section. Therefore, in order to reduce the aerodynamic noise level is to reduce the area of minimum cross section, it may be reduced airflow rate. However, the area of the minimum cross section 2500 mm 2 be smaller than, aerodynamic noise level does not change. In addition, if too small an area of the minimum cross section, because the ventilation amount is small, a problem that the cooling performance of the brake disk is lowered. For these reasons, the lower limit of the area of the minimum cross section is, 2500Mm 2 and. The lower limit, preferably, 3000Mm 2 and, more preferably 3500Mm 2 and.
[0048]
　8 is disclosed in Patent Document 3 is a diagram showing the relationship between the 1/3-octave band processing was performed center frequency and noise level. The noise level here means the aerodynamic noise level. Further, the sum of the opening areas in the drawing, is that the area of ​​the minimum cross section having a minimum area of ​​the spatial cross-section.
[0049]
　FIG. 8 is one in which the running speed has been obtained by experiments assuming a high-speed running is constant and 360km / h. In the experiment, a railway wheel having no brake disc, BD with railway wheels having a no brake discs of ribs, and BD with railway wheels ribs with slits are added is used. BD with railway wheels ribs with slits are added, conventional BD with railway wheel shown in FIG. 3A and 3B, i.e. the same as the BD with the railway wheels of the comparative embodiment shown in FIG. 6A and 6B. As this is added BD with railway wheels ribs with slits, the area of the spatial cross-section with a minimum cross section corresponding to the position of the ribs 18000Mm 2 and what is, 7000 mm 2 is employed what is .
[0050]
　As shown in FIG. 8, the area of the spatial cross section 7000mm at minimum cross section corresponding to the position of the ribs 2 For a BD with railway wheels, the area of 18000Mm 2 compared to that of BD with railway wheels is and the center frequency can be significantly reduced aerodynamic noise of the frequency band of 800 Hz ~ 1250 Hz. On the other hand, the results of the thermal fluid analysis described above, the relationship between the spatial cross-sectional area as the aerodynamic sound level in the minimum cross section, match the conventional BD with railway wheels of comparative form a BD with the railway wheels of the embodiment to. From these things, in the BD with railway wheels of this embodiment, the upper limit of the area of the minimum cross section is, 7000Mm 2 and. The upper limit is more preferably 6000Mm 2 and.
[0051]
　In BD with railway wheels of the present embodiment having such a configuration, as shown in FIG 5A and 5B, the brake disk 1 has no rib 7, and a fin portion 3 on the back surface of the disc portion 2 it is only a simple shape. Thus, no step of manufacturing the brake disk 1 is complicated, the productivity of the brake disc 1 is excellent. Even when manufacturing a brake disc 1 by forging, not the load of the mold is increased, nor mold life is shortened.
[0052]
　Also, BD with railway wheels of the present embodiment, the minimum cross section of the space cross-section is disposed on the rear surface portion a1 of the disk portion outer peripheral surface 2c of the brake disc 1, the area of ​​the space cross-section in the minimum cross section since it delimits the aerodynamic noise can be suppressed to the prior art equivalent.
Industrial applicability
[0053]
　Railway wheel with brake discs of the present invention can be effectively used for any rail vehicle having a disc brake, among others, it is useful for high-speed railway vehicle.
Description of the code
[0054]
　　1: brake
　　disc, 2: circular plate portion, 2a: surface, 2b: back, 2c: an outer peripheral
　　surface, 3: fin portion, 4: bolt hole, 5: bolt, 6:
　　nut, 7: ribs, 7a: slit,
　　10: the wheels, 11:
　　boss, 12: rim, 12a: side, 12b: the inner circumferential
　　surface, 12Ba: corner surface, 12bb: fillet
　　surface, 13: plate portion, 13a: side
The scope of the claims
[Claim 1]
　Boss portion, a rim portion, and a wheel for a railway vehicle having a plate portion connecting them,
　projecting surface side disc portion of the donut-shaped and sliding surface, and radially to the back surface of the disc portion comprising a brake disk provided with a plurality of fin portions which are and,
　two of said brake disc, sandwiching the plate portion of the wheel in a state where the individual said sliding surface outwardly, said sliding surface a region railway wheel with a brake disc that has been concluded with the inner,
　about the area of the cross section to cross along the formed space in the circumferential direction between said brake disc the wheel, and a minimum of this cross-sectional area the minimum cross section made are present in most back side of the outer peripheral surface of the circular plate portion of the areas formed by the outer peripheral surface and inner peripheral surface of the rim portion of the disc portion,
　said minimum cross section of area 2500Mm 2 or more, 7000Mm 2 is less than or equal to, railway wheels with brake disk.
[Claim 2]
　A railway wheel with a brake disk according to claim 1,
　in which the outer diameter of the disc portion is constant, the railway wheel with brake discs.