Railroad car bogies

Abstract

To provide a bogie truck capable of improving comfortableness of passengers when they getting on / off a railway vehicle while taking the fluctuation of a load and abrasion of a wheel into consideration.SOLUTION: A bogie truck includes a) two pairs of wheels (12) in that each pair of wheels (12) are connected to each other by an axle structure (14), b) a continuously-provided truck (18) to which each axle structure (14) is connected through primary suspension means (20), and c) secondary suspension means (22) that is supported by the truck (18) and has at least one leveling valve (26). At least one of the wheels (12) includes an abrasion detection component (30) for the wheel (12) and a link mechanism component (34) arranged between a leveling valve (26) and the abrasion detection component (30). The link mechanism component is suitable for transmitting the displacement of the abrasion detection component to the leveling valve to control the increase / decrease of the pressure inside the secondary suspension means (22).SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a) two pairs of wheels, each pair of wheels being connected to each other by an axle structure; b) an articulated chassis, each axle structure being connected through a primary suspension means; c) a secondary suspension means supported by the chassis, the secondary suspension means including at least one leveling valve; The present invention relates to a bogie truck for a railway vehicle. [Background technology]

[0002] A rail vehicle typically comprises at least one passenger car (voiture) mounted on a bogie which may be entirely located below the car or between two adjacent cars, and may also comprise at least one passenger car (voiture de transport de passagers). A passenger car typically comprises at least one passenger compartment equipped with seats for accommodating passengers, and at least one deck separated from the passenger compartment and having a door leading to the platform for passenger access.

[0003] The load of a railway vehicle, i.e., an increase in the mass carried by the vehicle and wear of the wheels, causes fluctuations in the floor height of the passenger car, which in turn causes fluctuations in the vertical distance in the height direction between the floor surface of the passenger car and the platform.

[0004] Such variations can cause problems when admitting people with limited mobility into carriages, and indeed when the vertical distance between the deck floor and the platform is too large, the boarding of such people becomes difficult.

[0005] No. 5,947,031 describes a bogie of the above type, which has a levelling valve on each longitudinal side of the bogie, connected to the secondary suspension by a rod attached to the axle box. The rod allows the suspension to expand or contract depending on the load applied to the bogie. However, the bogie described in US Pat. No. 5,947,031 cannot compensate for the variation in carriage height caused by wheel wear. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] U.S. Patent No. 5,947,031 Summary of the Invention [Problem to be solved by the invention]

[0007] One of the aims of the present invention is to remedy this deficiency by proposing a bogie that takes into account load variations and wheel wear, improving passenger comfort when getting on and off the train. [Means for solving the problem]

[0008] The invention therefore relates to a bogie of the aforementioned type, comprising, for at least one of the wheels, a wheel wear detection part and a linkage part between the levelling valve and the wheel wear detection part, which linkage part is suitable for transmitting the displacement of the wear detection part to the levelling valve to control the increase or decrease of the pressure in the secondary suspension means. The invention makes it possible, by means of the wear detection part and by means of the linkage part and by means of their arrangement with the wheels and the levelling valve, to reliably reduce the height distance between the floor of the carriage and the platform, taking into account the wear of at least one wheel, while at the same time making said distance adjustable depending on the load of the carriage, thereby improving passenger comfort.

[0009] According to particular embodiments of the invention, the bogie further comprises one or more of the following features, either alone or in any possible combination:

[0010] - the bogie bogie has two longitudinal sides, each carrying one wheel of each pair, the secondary suspension means comprising at least one levelling valve on each longitudinal side of the bogie bogie, the bogie bogie comprising, for each wheel, a wheel wear detection part and a linkage part between the levelling valve and the wheel wear detection part, the linkage part being suitable for transmitting the displacement of the wear detection part to the levelling valve to control an increase or decrease in pressure in the secondary suspension means.

[0011] Each wear detection component is connected to a corresponding wheel via a first pin connection, and the linkage component is connected on the one hand to the levelling valve via a second pin connection and on the other hand to the wear detection component of the wheel via a third movable pin connection and a fourth rigid pin connection.

[0012] Each wheel is rotatably movable about an axis, and a wheel wear detection component detects wheel wear by a reduction in the diameter of the wheel resulting in a displacement of a first pin connection of the wheel wear detection component towards the axis of rotation of the wheel.

[0013] - the levelling valve is connected via a fifth pin connection to an arm extending between the two longitudinal ends, the arm being connected at each of its two longitudinal ends via a second pin connection to a corresponding wheel linkage part.

[0014] - The distance measured in height between the fourth rigid pin connection and the wheel axis of rotation remains approximately constant regardless of wheel wear.

[0015] - The adjustment distance, measured in height between the second pin connection and the wheel axis, varies with wheel wear.

[0016] - the wheel wear detection part is connected to the chassis by a sliding connection and a spring device is provided between the first pin connection and the fourth rigid pin connection such that the wheel wear detection part is movable only in a translational movement in the height direction and the mechanical coupling part is rotationally movable around the fourth rigid pin connection.

[0017] The levelling valve is arranged to compensate for variations in the load of a railway carriage associated with the bogie by controlling the pressure in the secondary suspension means to increase when the load increases and to decrease when the load decreases.

[0018] The invention also relates to a railway carriage comprising at least one bogie according to the invention.

[0019] Other aspects and advantages of the invention will become apparent on reading the following description, given by way of example only with reference to the single accompanying drawing, in which: [Brief description of the drawings]

[0020] [Figure 1] FIG. 2 is a schematic side view of a bogie according to the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0021] In the following description, the terms "upper" and "lower" refer to the normal height direction Z of the railway vehicle, which is therefore approximately vertical on a horizontal ground surface.

[0022] With reference to FIG. 1, a bogie 10 for a railway vehicle will be described.

[0023] The bogie 10 has two pairs of wheels 12 .

[0024] The wheels 12 of each pair are interconnected by an axle structure 14 which includes an axle box 16 for each wheel 12 of a corresponding pair.

[0025] The bogie comprises an undercarriage 18. The undercarriage is, for example, an articulated undercarriage 18.

[0026] Each axle structure 14 is coupled to an undercarriage 18 through a primary suspension means 20. The primary suspension means 20 may include coil springs, air springs or the like.

[0027] The primary suspension means 20 typically comprises one or two springs per wheel 12. In the example shown, the primary suspension means 20 comprises one coil spring per wheel 12. The coil springs extend in a height direction Z.

[0028] The primary suspension means 20 damps vibrations along a height direction Z of the undercarriage 18 of the bogie 10 relative to the wheels 12 .

[0029] The bogie 10 includes a secondary suspension means 22 supported by the undercarriage 18. The secondary suspension means 22 may include coil springs, air springs or the like. The secondary suspension means 22 extends between the bogie 10 and a body 23 (shown in dashed lines in Figure 1) of the railway vehicle coach.

[0030] The bogie 10 has two longitudinal sides 24 extending in a longitudinal direction L.

[0031] Each longitudinal side 24 is provided with a respective pair of wheels 12 .

[0032] The secondary suspension means 22 typically comprises one or two springs per longitudinal side 24 .

[0033] In the example shown, the secondary suspension means 22 comprises one air spring per longitudinal side 24 approximately at the mid-distance between the rotation axes X of the wheels 12 located on each longitudinal side 24 .

[0034] The air spring extends in a height direction Z.

[0035] The secondary suspension means 22 dampens vibrations of the coach body 23 along the height direction Z relative to the bogie 10 .

[0036] The secondary suspension means 22 comprises at least one levelling valve 26 on each longitudinal side 24 of the bogie 10 .

[0037] The levelling valve 26 on a longitudinal side 24 is connected on the one hand to a pressurised fluid tank (not shown) and on the other hand to a secondary suspension means on the same longitudinal side 24 .

[0038] The pressurized fluid is, for example, air.

[0039] The levelling valve 26 comprises a lever 28 movable between a first end position and a second end position. When the lever 28 is displaced towards the first end position, the secondary suspension means 22 located on the longitudinal side 24 of the levelling valve 26 expands.

[0040] Expansion of the secondary suspension means 22 causes an upward displacement along the height direction Z of the floor surface of the carriage resting on the bogie 10 .

[0041] When the lever 28 is displaced towards the second end position, the secondary suspension means 22 located on the longitudinal sides 24 of the levelling valve 26 are compressed.

[0042] Contraction of the secondary suspension means 22 causes a downward displacement along the height direction Z of the floor surface of the carriage resting on the bogie 10 .

[0043] In the example shown, the levelling valves 26 are two in number and are symmetrical about the longitudinal centre line of the chassis 18 which is parallel to and mid-distance from both longitudinal sides 24 .

[0044] The bogie 10 includes, for each wheel 12, a wear detection part 30 for the wheel 12 connected to the wheel 12 via a first pin connection 32, and a link mechanism part 34 between the leveling valve 26 and the wear detection part 30 for the wheel 12.

[0045] The first pin connection 32 between the wear detection component 30 and the wheel 12 is formed by a rolling wheel having a diameter between 2% and 20% of the diameter of the wheel 12 on which it rests.

[0046] In the illustrated example, the first pin connection 32 is arranged above the wheel 12 so as to be in contact with the wheel 12 along the height direction Z.

[0047] The wear detection part 30 of the wheel 12 is connected to the chassis 18 by a sliding connection 36 which allows a translational movement of the wear detection part 30, advantageously also for the first pin connection 32, along the height direction Z, but does not allow a movement of the wear detection part 30, advantageously also for the first pin connection 32, along the longitudinal direction L.

[0048] The wear detection components 30 of the wheels 12 preferably do not include electronic components.

[0049] The linkage component 34 is connected to the leveling valve 26 via a second pin connection 38 while being connected to the wear detection component 30 of the wheel 12 via a third movable pin connection 40 and a fourth rigid pin connection 42 .

[0050] In the illustrated example, the linkage component 34 is generally "Z" shaped with both ends of the branch leading to a second pin connection 38 with the leveling valve 26 on one side and to a third movable pin connection 40 with the wear detection component 30 on the other side.

[0051] The linkage component 34 is rotatably movable about a rigid pin connection 42 and about an axis perpendicular to the longitudinal direction L and the height direction Z.

[0052] Preferably, the wear detection component 30 of the wheel 12 comprises a coil spring 44 between the first pin connection 32 or the wear detection component 30 and the fourth rigid pin connection 42. The coil spring 44 extends in the height direction Z.

[0053] Thereby, the wear detection part 30 of the wheel 12 is movable only in a translational movement in the height direction Z by displacing the sliding connection 36, while the fourth rigid pin connection 42 maintains a constant distance D with respect to the rotation axis X of the wheel 12 above which the fourth rigid pin connection is located.

[0054] Preferably, the wear detection components 30 and the linkage components 34 on the same longitudinal side 24 are symmetrical about a central vertical line of the chassis 18 that is perpendicular to both longitudinal sides 24 and is at a mid-distance from the rotation axis X of the wheel 12 on the corresponding longitudinal side 24.

[0055] Each leveling valve 26 is connected via a fifth pin connection 46 to an arm 48 extending between two longitudinal ends 50 , 52 .

[0056] Preferably, the fifth pin connection 46 between the levelling valve 26 and the arm 48 is positioned approximately equidistant to each of the second pin connections 38 connecting the arm 48 to each of the linkage parts 34 on the same longitudinal side 24 of the bogie 10.

[0057] This arrangement of the fifth pin connection 46 makes it possible to compensate for the average value of wear of the wheel 12 on one longitudinal side 24 .

[0058] The arm 48 is connected at each of its longitudinal ends 50 , 52 to the linkage component 34 of the corresponding wheel 12 via a second pin connection 38 .

[0059] The arms 48 are preferably telescoping so as to smooth out any slight relative longitudinal movements that may occur between the axle boxes 16 during travel.

[0060] An adjustment distance a is defined, measured in the height direction Z, between the second pin connection 38 and the rotation axis X of the corresponding wheel 12. The adjustment distance a varies depending on the diameter of the wheel 12 and therefore on the wear of the wheel 12.

[0061] The operation of the bogie 10 according to the present invention will now be described.

[0062] As any wheel 12 wears, its diameter decreases, which causes a displacement of the first pin connection 32 towards the rotation axis X of the wheel 12 .

[0063] In particular, the first pin connection 32 is displaced in the height direction Z downwards.

[0064] The wear detection component 30 of the corresponding wheel 12 is translated downward in the height direction Z while displacing the sliding connection 36, stretching the coil spring 44 so that the fourth rigid pin connection 42 remains at a constant distance D relative to the rotation axis X of the wheel 12 above which the fourth rigid pin connection 42 is located.

[0065] Displacement of the first pin connection 32 downward in the height direction Z causes the link mechanism part 34 to undergo rotational displacement about the fourth rigid pin connection 42 .

[0066] When the link mechanism part 34 is rotationally displaced about the fourth rigid pin connection 42, the corresponding second pin connection 38 is caused to displace upward in the height direction Z.

[0067] The adjustment distance a increases. The upward displacement of the corresponding second pin coupling 38 causes the arm 48 to tilt.

[0068] Then, the tilting of the arm 48 in turn causes the fifth pin connection 46 to be displaced upward in the height direction Z, thereby causing the lever 28 of the leveling valve 26 to be displaced upward.

[0069] Upward displacement of the lever 28 increases the pressure in the secondary suspension means 22 on the same longitudinal side 24. Pressurized fluid in the tank is injected into the secondary suspension means 22 causing it to expand.

[0070] This raises the floor of the carriages mounted on the bogies 10, compensating for the height loss caused by wheel wear, thereby facilitating passengers, especially those with reduced mobility, to get in and out of the carriages.

[0071] Compensation for variations in coach load is also achieved by the levelling valve 26, preferably by displacement of a lever 28, by increasing the pressure in the secondary suspension means 22 by injecting pressurised fluid into the secondary suspension means 22 when the load increases, or decreasing the pressure in the secondary suspension means 22 by removing pressurised fluid from the secondary suspension means 22 when the load decreases.

[0072] This increases passenger comfort.

[0073] The bogie 10 of the present invention also reduces maintenance costs due to wear on the wheels 12 and eliminates the need for chocks.

[0074] Furthermore, the wear sensing components of the wheels 12, the linkage components 34, and the arms 48 are all completely mechanical components and do not require electronic components, and therefore no power source, for secondary suspension height adjustment. [Explanation of symbols]

[0075] 10 Bogie 12 wheels 14 Axle structure 16 Axle box 18 Chassis 20 Primary Suspension Means 22 Secondary Suspension Means 23 Body 24 Longitudinal side 26 Leveling valve 28 Lever 30 Wear detection parts 32 First pin connector 34 Link mechanism parts 36 Slipping Bond 38 Second Pin Connection 40 Third movable pin connection 42 4th rigid pin connection 44 Coil springs, spring devices 46 5th pin connection 48 Arm 50, 52 Longitudinal end D Distance L Longitudinal X Rotation Axis Z height direction a Adjustment distance

Claims

1. a) two pairs of wheels (12), each pair of wheels (12) being connected to each other by an axle structure (14); b) a chassis (18) to which each axle structure (14) is connected through a primary suspension means (20); c) a secondary suspension means (22) supported by said chassis (18), said secondary suspension means (22) including at least one leveling valve (26); A bogie truck (10) for a railway vehicle, comprising: - for at least one of said wheels (12), a wear-detection part (30) of said wheel (12) and a linkage part (34) between said levelling valve (26) and said wear-detection part (30) of said wheel (12), said linkage part being suitable for transmitting the displacement of said wear-detection part to said levelling valve to control the increase or decrease of pressure in said secondary suspension means (22); Each wear detection component is connected to a corresponding wheel (12) via a first pin connection (32), and the link mechanism component (34) is connected to the leveling valve (26) via a second pin connection (38) on the one hand and to the wear detection component (30) of the wheel via a third movable pin connection (40) and a fourth rigid pin connection (42) on the other hand. A bogie truck (10) characterized by:

2. 2. The bogie (10) according to claim 1, wherein the bogie (10) has two longitudinal sides (24), each of which is provided with one wheel (12) of each pair, the secondary suspension means (22) comprises at least one levelling valve (26) on each longitudinal side (24) of the bogie (10), the bogie (10) comprises, for each wheel, a wear detection part and a linkage part (34) between the levelling valve (26) and the wear detection part (30) of the wheel (12), the linkage part being suitable for transmitting the displacement of the wear detection part to the levelling valve to control the increase or decrease of pressure in the secondary suspension means (22).

3. 3. The bogie (10) according to claim 1 or 2, wherein each wheel (12) is rotatably movable about an axis (X), and the wear detection part (30) of the wheel (12) detects wear of the wheel (12) by a reduction in diameter of the wheel (12) resulting in a displacement of a first pin connection (32) of the wear detection part of the wheel towards the rotation axis (X) of the wheel (12).

4. 4. The bogie (10) according to any one of claims 1 to 3, wherein the levelling valve (26) is connected to an arm (48) having two longitudinal ends (50, 52) via a fifth pin connection (46), and the arm (48) is connected at each of its two longitudinal ends (50, 52) to the link mechanism part (34) of the corresponding wheel (12) via the second pin connection (38).

5. 5. The bogie (10) according to any one of claims 1 to 4, wherein a distance (D) measured in a height direction (Z) between the fourth rigid pin connection (42) and the axis of rotation (X) of the wheel (12) is constant regardless of wear of the wheel (12).

6. 6. The bogie (10) according to any one of claims 1 to 5, wherein an adjustment distance (a), measured in height between the second pin connection (38) and the axis of rotation (X) of the wheel (12), varies with wear of the wheel (12).

7. 7. The bogie (10) according to any one of claims 1 to 6, wherein the wear detection part (30) of the wheel (12) is connected to the chassis (18) by a sliding connection (36) and a spring device (44) is provided between the first pin connection and the fourth rigid pin connection (42) so that the wear detection part (30) of the wheel (12) is movable only in a translational movement in the height direction (Z) and the link mechanism part (34) is rotationally movable around the fourth rigid pin connection (42).

8. 8. The bogie (10) according to any one of claims 1 to 7, wherein the levelling valve is configured to compensate for variations in the load of a railway carriage associated with the bogie by controlling the pressure in the secondary suspension means to increase when the load increases and to decrease when the load decreases.

9. A railway carriage comprising at least one bogie (10) according to any one of the preceding claims.

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