JP2007145224A - Wheel for railway rolling stock and its designing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a wheel for a railway rolling stock capable of improving travelling safety by more certainly preventing occurrence of a derailing accident and its designing method. <P>SOLUTION: This wheel for the railway rolling stock has a tread circular arc part including more than two recessed circular arc parts continuing from a neutral point and a tread including a flange part continuously provided on one end of the tread circular arc part, the flange part 3 makes an angle more than 70 degrees against a rotation axis and continuously provided on one end 2E of the tread circular arc part 2 on one end of a linear part 31, and it is furnished with the linear part 31 in parallel with the rotation axis and effective flange height which is a distance between a horizontal straight line H passing through the neutral point CP and the other end 31E of the straight line 31 of which is longer than 22mm and a protruded type circular arc part 32 continuously provided on the other end 31E of the straight line part 31. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a railway vehicle wheel having a tread surface arc portion and a flange portion on a cross section that is parallel to a rotation axis and passes through the center of rotation, and a design method thereof.

Conventionally, as a countermeasure against a derailment accident due to an earthquake or the like in a railway vehicle such as a Shinkansen, for example, the wheel structure of a railway vehicle can be designed so that the limit value of the derailment coefficient shown in Non-Patent Document 1 below is increased. Are known. By increasing the limit value of the derailment coefficient, the occurrence of a derailment accident can be prevented more reliably. The limit value of the derailment coefficient is given by the following relational expression (1).

Here, Q is the lateral pressure acting on the wheel, and P is the wheel load. Further, as shown in FIG. 5 showing the wheel shaft in which the flange collides, G is a wheel / rail contact point interval, and i _B is a point _B of the wheel shaft (that is, the opposite side to the collision side wheel). The turning radius around the contact point between the wheel tread and the rail surface. It should be noted that the relational expression i _B = √ (inertia moment I _B around the contact point of one wheel tread on the wheel shaft / wheel shaft mass m) is established. Α is the flange angle, μ is the friction coefficient, P is the wheel load, and Pw is the wheel load due to the unsprung weight. Further, h is the flange height (that is, the length from the wheel tread to the flange head), and t ₁ is the impact action time.

Conventionally, as shown in FIG. 6, many of the above-described railcar wheels are designed with the above parameters set to 30 mm for the flange height h and 70 degrees for the flange angle α.
Railway Technical Research Institute (supervised by the Railway Bureau of the Ministry of Transport), “Safety Standard for Jumping Derailment”, Conventional Railway Speed Improvement Test Manual / Commentary, Kenyusha, May 10, 1993, p . 85

  The present inventors have intensively studied in order to more reliably prevent the occurrence of a derailment accident and improve the running safety. As a result, the present inventors have found that there is still room for improvement with respect to the wheel structure using the above-described conventional parameters in order to further improve the running safety.

  The present invention was made in order to solve such a conventional problem based on the above knowledge, and more reliably prevents the occurrence of a derailment accident and improves the traveling safety, and a railway vehicle wheel. It aims at providing the design method.

  In order to achieve the above object, a railcar wheel according to the present invention has a tread arc including one or more concave arc portions that are continuous from a neutral point with respect to the outer shape of a cross section when cut by a plane including a rotation axis. And a railcar wheel having a tread surface including a flange portion connected to one end of the tread arc portion, the flange portion forming an angle greater than 70 degrees with respect to the rotation axis and the linear portion A straight line that is connected to one end of the arc of the tread surface at one end of the straight line and that has an effective flange height that is parallel to the rotation axis and that is the distance between the horizontal straight line passing through the neutral point and the other end of the straight line portion is longer than 22 mm. And a convex arc portion provided continuously with the other end of the straight portion.

  Further, the design method of the wheel for a rail vehicle according to the present invention is a tread arc portion including one or more concave arc portions that are continuous from a neutral point with respect to the outer shape of a cross section when cut by a plane including a rotation axis, A method for designing a wheel for a railway vehicle having a tread including a flange portion continuously provided at one end of the tread arc portion, wherein the tread is formed at an angle greater than 70 degrees with respect to the rotation axis and at one end of the straight portion. A straight line of the flange portion that is connected to one end of the arc portion and is parallel to the rotation axis and has an effective flange height that is a distance between the horizontal straight line passing through the neutral point and the other end of the straight portion is longer than 22 mm. A linear portion defining step for defining the portion; and a convex arc portion defining step for defining the convex arc portion of the flange portion, which is connected to the other end of the linear portion.

  According to the railway vehicle wheel and the design method thereof according to the present invention, the straight portion of the flange portion forms an angle larger than 70 degrees with respect to the rotation axis. For this reason, the limit value of the derailment coefficient can be increased based on the above relational expression, compared with the conventional railcar wheel having this angle of 70 degrees. In addition, according to the railway vehicle wheel and the design method thereof according to the present invention described above, the effective flange height that is the distance between the horizontal straight line and the other end of the straight line portion is longer than 22 mm. In the conventional railcar wheel having the flange height of 30 mm and the flange angle of 70 degrees, the effective flange height is 22 mm. For this reason, by making the effective flange height longer than 22 mm, the flange height becomes longer than that of the conventional railway vehicle wheel. Therefore, the limit value of the derailment coefficient is increased based on the above relational expression. can do. As a result, it is possible to more reliably prevent the occurrence of a derailment accident and further improve traveling safety.

  The distance between the neutral point and the inner end face of the flange portion is preferably longer than 69.15 mm.

  Thus, by making the distance between the neutral point and the inner end face of the flange portion longer than 69.15 mm, which is the distance in the conventional railway vehicle wheel, the position of the contact point between the railway vehicle wheel and the rail is set. It can be moved in the direction opposite to the flange portion. As a result, it is possible to more reliably prevent the occurrence of a derailment accident and further improve traveling safety.

In the railway vehicle wheel according to the present invention, the tread arc portion includes a concave arc portion having a curvature of 0.0 to 1.0 m ⁻¹ and a concave arc portion having a curvature of 1.3 to 1.5 m ^−1. , A concave arc portion having a curvature of 16.5 to 19.5 m ⁻¹ , and a concave arc portion having a curvature of 66.5 to 74.0 m ⁻¹ while sequentially connecting the convex arc portion Preferably, the radius of curvature is less than 12 mm.

  Thus, the tread surface arc portion includes the concave arc portions having the curvatures described above while being sequentially arranged, thereby moving the contact point between the railcar wheel and the rail in the direction opposite to the flange portion. Can do. Moreover, the contact area of a convex circular arc part and a rail can be expanded by making the curvature radius of a convex circular arc part smaller than 12 mm. As a result, it is possible to more reliably prevent the occurrence of a derailment accident and further improve traveling safety.

  ADVANTAGE OF THE INVENTION According to this invention, generation | occurrence | production of a derailment accident can be prevented more reliably and driving | running | working safety can be improved more.

  DESCRIPTION OF EMBODIMENTS Hereinafter, preferred embodiments according to the present invention will be described in detail with reference to the accompanying drawings. In addition, the same code | symbol shall be used for the same element and the overlapping description is abbreviate | omitted. Further, the dimensional ratios in the drawings do not necessarily match those described.

  In FIG. 1, the external shape of the cross section of the wheel 10 for rail vehicles which concerns on this embodiment is shown. A wheel 10 for a railway vehicle such as a Shinkansen has a tread surface arc portion 2 and a flange with respect to the outer shape of a cross section (that is, a cross section parallel to the rotation axis and passing through the rotation center) when cut by a plane including the rotation axis. It has a tread including part 3.

The tread surface arc portion 2 is a substantially arc-shaped portion including one or more concave arc portions that are continuous from a neutral point CP (a position 77.5 mm from the wheel flange end surface E that is the inner end surface of the flange portion 3). Here, the concave arc portion is a substantially arc-shaped portion recessed inward as viewed from the wheel 10 side. In the present embodiment, the tread surface arc portion 2 includes four concave arc portions 21 to 24 that are successively arranged. The radius of curvature of each of the four concave arc portions 21 to 24 is 1000 mm, 700 mm, 52 mm, and 14 mm. Incidentally, four concavely curved portions 21 to 24 each ^{curvature, 0.0~1.0m -1, 1.3~1.5m -1, 16.5~19.5m} -1, and 66.5～ If it exists in the range of 74.0m < ^-1 >, it will not specifically limit. The center position serving as a reference for the radius of curvature of each of the four concave arc portions 21 to 24 is 90 mm from the wheel flange end surface E (that is, 12.5 mm in the direction away from the flange portion 3 starting from the neutral point CP). , 60 mm, 50 mm, and 40 mm. Note that the curvature of the neutral point CP of the tread surface of the wheel 10 is 1.0 m ⁻¹ , that is, the curvature radius R _wheel is 1000 mm (in contrast, the curvature radius R _rail of the top of the _rail is 600 mm). Therefore, the tread gradient δ is obtained as δ = 12.5 mm / 1000 mm = 1/80.

  The flange portion 3 is a substantially flange-shaped portion that is connected to one end 2E of the tread surface arc portion 2 (position 30 mm from the wheel flange end surface E). Here, the flange part 3 is provided with the linear part 31 and the convex circular arc part 32 regarding said cross section, as shown in FIG. The flange portion 3 is connected to one end 2E of the tread surface arc portion 2 at one end of the linear portion 31.

  The straight line portion 31 forms an angle larger than 70 degrees with respect to the rotation axis. That is, the flange angle α of the flange portion 3 is larger than 70 degrees. The flange angle α is preferably greater than 70 degrees and not greater than 80 degrees, and more preferably 75 degrees. When the flange angle α is 70 degrees or less, the limit value of the derailment coefficient cannot be made larger than that of the conventional railway vehicle wheel according to the relational expression (1). Further, when the flange angle α is larger than 80 degrees, the wheel 10 may ride up on the Tongler connecting the missing part of the rail such as the point part of the branching device and the expansion joint.

  Further, with respect to the straight line portion 31, the distance between the horizontal straight line H and the other end 31E of the straight line portion 31 (hereinafter referred to as an effective flange height eh) is longer than 22 mm. Here, the horizontal straight line H is a virtual straight line that is parallel to the rotation axis and passes through the neutral point CP. The effective flange height eh is preferably longer than 22 mm and 29 mm or less, more preferably 26 mm (that is, the flange height h is preferably longer than 30 mm and 35 mm or less, and 32 mm). More preferred). When the effective flange height eh is 22 mm or less, the conventional railcar wheel having the flange angle α of 70 degrees corresponds to the case where the flange height h is 30 mm or less. Therefore, according to the relational expression (1), the limit value of the derailment coefficient is made larger than that of the conventional railway vehicle wheel in which the flange height h is 30 mm and the flange angle α is 70 degrees. I can't. Moreover, when the effective flange height eh is larger than 29 mm, the critical dimension of the lower part of the vehicle, which should not be exceeded when the vehicle is placed on the rail, is exceeded. When the effective flange height eh is 26 mm, the radius of curvature of the convex arcuate portion 32 is 8 mm, and the flange angle α is 75 degrees, the above flange height h corresponds to the case of 32 mm (26 + 8 × (1 -Cos 75 °) = 32). Here, in the wear of the wheel 10 due to the daily running of the vehicle, the wheel 10 is worn violently in the vicinity of the neutral point CP that is in frequent contact with the rail, and is not worn at the tip portion of the flange portion 3. By such relative wheel wear, the flange height h increases. Even when the wear progresses in this way, it is more preferable that the flange height h is 32 mm with a 3 mm margin so that the flange height h does not reach 35 mm. When the radius of curvature of the convex arc portion 32 is 8 mm, the flange angle α is 75 degrees, and the flange height h is 35 mm, the effective flange height eh corresponds to the case of 29 mm (35-8 × (1 -Cos 75 °) = 29).

  The convex arc portion 32 is a substantially arc-shaped portion that protrudes outward as viewed from the wheel 10 side with respect to the cross section, and is connected to the other end 31 </ b> E of the linear portion 31. The radius of curvature of the convex arc portion is smaller than 12 mm. In addition, it is preferable that the curvature radius of a convex circular arc part is 8 mm. This is because if the radius of curvature of the convex circular arc portion is smaller than 8 mm, the wheel 10 may ride on the Tongleil that connects the missing portion of the rail such as the point portion of the branching device or the expansion joint.

  Next, a method for designing the railway vehicle wheel 10 will be described. In FIG. 2, the flowchart showing the step with which the design method of the wheel 10 for rail vehicles is provided is shown. The design method of the railway vehicle wheel 10 includes a tread surface arc part defining step, a straight line part defining step, and a convex arc part defining step. By executing these steps in order, the railway vehicle wheel 10 can be designed. Here, the design method of the portion that is away from the flange portion 3 starting from the neutral point CP (that is, the right side portion from the neutral point CP in FIG. 1) is the same method as the conventional design method of the wheel for a railway vehicle. I'll omit the explanation here. Similarly, the design method of the portion away from the neutral point CP starting from the convex arc portion 32 (that is, the left portion from the convex arc portion 32 in FIG. 1) is also omitted here.

  First, in the tread arc portion defining step, a concave arc portion 21 having a radius of curvature of 1000 mm, a concave arc portion 22 having a radius of curvature of 700 mm, a concave arc portion 23 having a radius of curvature of 52 mm, and a radius of curvature of 14 mm. The tread surface arc portion 2 is defined while connecting a certain concave arc portion 24 in order from the neutral point CP (step S1).

  Next, in the straight line portion defining step, the straight portion 31 of the flange portion 3 is defined (step S2). The straight portion 31 has an angle greater than 70 degrees with respect to the rotation axis with respect to the cross section, and is connected to one end 2E of the tread arc portion 2 at one end of the straight portion 31 and has an effective flange height. eh is longer than 22 mm.

  Finally, in the convex arc portion defining step, the convex arc portion 32 of the flange portion 3 is defined (step S3). In addition, this convex circular arc part 32 is. With respect to the cross-section, the other end 31E of the linear portion 31 is connected. Here, regarding the definition of the convex arc portion 32, the convex arc portion 32 having a radius of curvature smaller than 12 mm may be specified.

Next, the operation and effect of the railway vehicle wheel 10 and its design method according to the present embodiment will be described. According to the railway vehicle wheel 10 and the design method thereof according to the present embodiment, the straight portion 31 of the flange portion 3 forms an angle greater than 70 degrees with respect to the rotation axis with respect to the cross section. When this angle is changed from the conventional 70 degrees to, for example, 75 degrees, the portion of the following relational expression (2) in the relational expression (1) is about 2.077 when the friction coefficient μ is 0.1. To a value of about 2.645. Therefore, the relative ratio of the relational expression (2) is about 1.273 (that is, the relative ratio of the derailment coefficient limit value is increased by about 27.3 percent).

  Thus, the limit value of the derailment coefficient can be increased based on the above relational expression, compared with the conventional railcar wheel having this angle of 70 degrees. As a result, it is possible to more reliably prevent the occurrence of a derailment accident and further improve traveling safety. Further, by setting this angle to an angle larger than 70 degrees, the width of the flange portion 3 is shortened to 30 mm (see FIG. 1). As a result, since the lateral clearance between the wheel 10 and the rail increases, it is possible to increase the wheel radius difference during curve traveling.

Further, according to the railway vehicle wheel 10 and the design method thereof according to the present embodiment, the distance between the horizontal straight line H and the other end 31E of the straight portion 31 (that is, the effective flange height eh) is longer than 22 mm. In the conventional railway vehicle wheel in which the flange height is 30 mm and the flange angle is 70 degrees, the effective flange height eh is 22 mm (see FIG. 6). For this reason, by making the effective flange height eh longer than 22 mm, the above-described flange height becomes longer than that of a conventional railway vehicle wheel. Here, since the contact part of the flange part 3 and a rail reduces gradually in the front-end | tip part of the flange part 3, these inventors are h in the following relational expression (3) in said relational expression (1). It was found that the limit value of the derailment coefficient can be estimated more appropriately by substituting the effective flange height eh. Based on this knowledge, when the effective flange height eh is changed from the conventional 22 mm to 26 mm, for example, the relative ratio of the relational expression (3) is about 1.087 times (that is, the relative ratio of the derailment coefficient limit value). Is increased by about 8.7%). As a result, it is possible to more reliably prevent the occurrence of a derailment accident and further improve traveling safety.

  As described above, the limit value of the derailment coefficient of the wheel 10 can be increased based on the relational expression as compared with the conventional railway vehicle wheel. As a result, it is possible to more reliably prevent the occurrence of a derailment accident and further improve traveling safety. For example, as described above, when the effective flange height eh is increased from 22 mm to 26 mm, for example, from 70 degrees to 75 degrees, the derailment coefficient limit value is multiplied by about 1.273 and further about 1. Since it is 087 times, the result is about 1.384 times. That is, the relative ratio of the derailment coefficient limit increases by about 38.4 percent. As a result, it is possible to more reliably prevent the occurrence of a derailment accident and further improve traveling safety.

  FIG. 3 is a graph showing the relationship between the relative ratio of the derailment coefficient limit value and the friction coefficient. This graph assumes that the effective flange height eh has been changed from 22 mm to 26 mm. The flange angle α is shown for three types of 75 degrees, 77 degrees, and 79 degrees. This relative ratio for each of these flange angles α is greater than about 1.3 regardless of the size of the friction coefficient μ. That is, the derailment coefficient limit value can be increased by 30% or more compared with the conventional railcar wheel having a flange angle α of 70 degrees. Regarding the friction coefficient μ, the relative ratio is considered to be about 0.03 in the case of rain, and about 0.1 in the case of high-speed driving, and the above relative ratio becomes minimum when the friction coefficient μ is about 0.5. . Further, the relative ratio is further increased by setting the flange angle α to 77 degrees from 75 degrees and further to 79 degrees from 77 degrees. That is, as the flange angle α is increased, the relative ratio can be increased. Therefore, the occurrence of a derailment accident can be prevented more reliably, and traveling safety can be further improved.

  Moreover, according to the railway vehicle wheel 10 and the design method thereof according to the present embodiment, the tread surface arc portion 2 includes the concave arc portions 21 to 24 having the above-described curvature radii in order. Therefore, the distance between the neutral point CP and the wheel flange end face E (ie, 77.5 mm) is longer than the distance (ie, 69.15 mm) in the conventional railway vehicle wheel. Thereby, the position of the contact point between the railcar wheel 10 and the rail can be moved in the direction opposite to the flange portion 3. The distance between the neutral point CP and the wheel flange end surface E is not particularly limited as long as it is longer than 69.15 mm. FIG. 4 shows a graph schematically showing a state in which the position of the contact point between the wheel 10 and the rail is changed with the lateral displacement of the wheel 10. 4A shows a change in the position of the contact point in the case of the wheel 10 according to the present embodiment, and FIG. 4B shows a change in the position of the contact point in the case of a conventional railway vehicle wheel. ing. The horizontal axis indicates the relative horizontal direction (width direction) position where the top of the rail is 0, and the vertical axis indicates the relative height where the top of the rail is 0. In addition, when the wheel 10 is laterally displaced by 1 mm, the contact points between the wheel 10 and the rail are connected by a thin line (in order to make it easy to see the thin line connecting the contact points, the wheel 10 is about 10 mm. Is displayed in a floating state). Moreover, the rails are calculated on the assumption that 60 kg of rails per meter are used.

  When the conventional railway vehicle wheel is changed to the structure of the wheel 10 according to the present embodiment, as shown in FIGS. 4 (a) and 4 (b), the position of the contact point is the flange portion 3. It is moving away from the direction. Hereinafter, this reason will be described. Whereas the position of the neutral point CP is conventionally 69.15 mm from the wheel flange end surface E (see FIG. 6), in the present embodiment, the tread surface arc portion 2 is the concave arc portion 21 having the above-described radius of curvature. -24 are included while being arranged in order, so that the position is 77.5 mm from the wheel flange end face E (see FIG. 1). As a result, the position of the contact point moves in a direction away from the flange portion 3 (that is, a direction opposite to the flange portion 3). Furthermore, by making the curvature radius of the convex arc portion 32 smaller than 12 mm, the contact area between the convex arc portion 32 and the rail can be enlarged. As a result, it is possible to more reliably prevent the occurrence of a derailment accident and further improve traveling safety.

Here, the wheel 10 normally rotates in a range of about ± 3 mm around the neutral point CP. Therefore, the tread gradient δ indicating the positional relationship between the wheel tread at the neutral point CP and the top of the rail is an important factor. As described above, the radius of curvature R _wheel of the neutral point CP of the tread of the wheel 10 is 1000 mm, and the radius of curvature R _rail of the top of the _rail is 600 mm. Further, the tread gradient δ is 1/80. On the other hand, in the conventional railway vehicle wheel, the curvature radius R _wheel and the curvature radius R _rail are common, but the tread gradient δ is δ = 25 mm / 1000 mm = 1/40 (see FIG. 6). Here, the theoretical equivalent tread surface gradient λe is obtained based on the following relational expression (4), and the wheel 10 according to the present embodiment is compared with the conventional railcar wheel (the Japan Opportunity Society, “Wheels”). "Equivalent tread slope of treads", Railway vehicle dynamics Latest truck technology, Electric vehicle workshop, p.24).

  Based on the relational expression (4), the equivalent tread gradient λe for the wheel 10 according to the present embodiment is 1/32. On the other hand, the equivalent tread gradient λe for the conventional railway vehicle wheel is 1/16. The equivalent tread gradient λe for the wheel 10 according to the present embodiment has a smaller equivalent tread gradient λe, so that the running stability and vibration riding comfort during high speed running are improved. In this way, by making the structure of the wheel 10 have the tread gradient δ as in this embodiment, it is possible to improve the running stability and the vibration ride comfort during high speed running.

It is a figure which shows the external shape of the cross section of the wheel for rail vehicles which concerns on embodiment of this invention. It is a flowchart showing the step with which the design method of the wheel for rail vehicles is equipped. It is a graph showing the relationship between the relative ratio of the limit value of a derailment coefficient, and a friction coefficient. It is a graph which represents typically a mode that the position of the contact point of a wheel and a rail changes with lateral displacement of a wheel. It is a schematic diagram showing the wheel axis which has flange collision. It is a figure which shows the external shape of the cross section of the wheel for conventional rail vehicles.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 2 ... Tread surface arc part, 2E ... One end, 3 ... Flange part, 10 ... Rail vehicle wheel, 21-24 ... Concave arc part, 31 ... Linear part, 31E ... Other end, 32 ... Convex arc part, CP ... Neutral Point, E: Wheel flange end face, H: Horizontal straight line, α: Flange angle.

Claims (4)

Regarding the outer shape of the cross-section when cut along a plane including the rotation axis, a tread surface arc portion including one or more concave arc portions continuing from a neutral point, and a flange portion connected to one end of the tread arc portion A railcar wheel having a tread surface including:
The flange portion is
A horizontal straight line that forms an angle greater than 70 degrees with respect to the rotation axis, is connected to one end of the tread surface arc portion at one end of the linear portion, and is parallel to the rotation axis and passes through the neutral point; A straight portion having an effective flange height that is a distance from the other end of the straight portion, which is longer than 22 mm;
A convex arc portion connected to the other end of the linear portion;
A rail vehicle wheel comprising: The distance between the neutral point and the inner end face of the flange portion is longer than 69.15 mm,
The wheel for a railway vehicle according to claim 1. The tread arc portion is
A concave arc portion having a curvature of 0.0 to 1.0 m ⁻¹ ;
A concave arc portion having a curvature of 1.3 to 1.5 m ⁻¹ ;
A concave arc portion having a curvature of 16.5 to 19.5 m ⁻¹ ;
Including a concave arc portion having a curvature of 66.5 to 74.0 m ⁻¹ while being sequentially arranged,
The convex arc portion has a radius of curvature smaller than 12 mm.
The wheel for a railway vehicle according to claim 1 or 2. Regarding the outer shape of the cross-section when cut along a plane including the rotation axis, a tread surface arc portion including one or more concave arc portions continuing from a neutral point, and a flange portion connected to one end of the tread arc portion A method of designing a railway vehicle wheel having a tread including:
A horizontal straight line that forms an angle greater than 70 degrees with respect to the rotation axis, is connected to one end of the tread surface arc portion at one end of the linear portion, and is parallel to the rotation axis and passes through the neutral point; A linear portion defining step for defining a straight portion of the flange portion, wherein an effective flange height, which is a distance from the other end of the straight portion, is longer than 22 mm;
A convex arc portion defining step for defining a convex arc portion of the flange portion, which is connected to the other end of the linear portion;
A method for designing a wheel for a railway vehicle comprising:

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