Bogie of a rail vehicle

Abstract

This application relates to a bogie of a rail vehicle, comprising: a) two pairs of wheels (12), each pair of wheels (12) being connected to each other by an axle structure (14); b) a articulated frame (18), each axle structure (14) being connected to the frame (18) by a main suspension device (20); and c) a secondary suspension device (22) carried on the frame (18) and including at least one leveling valve (26); for at least one of the wheels (12), a wear detection member (30) of the wheel (12) and a mechanical connection member (34) located between the leveling valve (26) and the wear detection member (30), the mechanical connection member being used to transmit the displacement of the wear detection member to the leveling valve to control an increase or decrease in the existing pressure in the secondary suspension device (22).

Description

Technical Field

[0001] The present invention relates to a bogie for a rail vehicle, comprising:

[0002] a) two pairs of wheels, each pair of wheels (12) being connected to each other by an axle structure;

[0003] b) a hinged frame, each axle structure being connected to the frame by a main suspension device; and

[0004] c) a secondary suspension device carried on the frame, the secondary suspension device including at least one leveling valve. Background Art

[0005] A rail vehicle generally includes at least one carriage mounted on a bogie, the bogie being capable of being fully carried under a carriage or between two adjacent carriages, and in some cases being at least one passenger carriage. A passenger carriage generally includes at least one compartment and a platform separated from the compartment, the compartment being equipped with seats to accommodate passengers, and the platform providing a door for boarding the carriage from a platform or alighting from the carriage to a platform.

[0006] The increase in the load of a rail vehicle, i.e., the increase in the mass carried by the vehicle, and the wear of the wheels change the height of the carriage floor and the vertical distance in the height direction between the vehicle floor and the platform.

[0007] For example, when the vehicle transports people with limited mobility, such changes cause trouble. In fact, an excessive vertical distance between the floor of the platform and the platform makes it troublesome to enter the carriage.

[0008] US5,947,031 describes a bogie of the above type, which includes leveling valves at each longitudinal side of the bogie, the leveling valves being connected to the secondary suspension by connecting rods fixed to the axle boxes. The connecting rods allow the suspension to expand or contract according to the load applied to the bogie. However, the bogie described in US5,947,031 cannot compensate for the change in the carriage height caused by the wear of the wheels. Summary of the Invention

[0009] One object of the present invention is to alleviate the above defects by providing a bogie that improves the comfort of passengers boarding or alighting from the carriage by considering load changes and wheel wear.

[0010] To this end, the present invention relates to a bogie of the above type. For at least one of the wheels, the bogie includes a wear detection member of the wheel and a mechanical connection member located between the leveling valve and the wear detection member of the wheel. The mechanical connection member is used to transmit the displacement of the wear detection member to the leveling valve to control an increase or decrease in the existing pressure in the secondary suspension device. Through the wear detection member, the mechanical connection member, and their settings between the wheel and the leveling valve, the present invention can reliably reduce the distance in the height direction between the carriage floor and the platform by considering the wear of at least one wheel, so that this distance can be adjusted according to the load of the carriage, thereby improving the comfort of passengers.

[0011] According to a specific embodiment of the present invention, the bogie further has one or more of the following features, which are selected in isolation or in any possible combination:

[0012] - The bogie has two longitudinal sides, each longitudinal side includes one wheel of each pair, the secondary suspension device includes at least one leveling valve on each longitudinal side of the bogie, and the bogie includes a wear detection member for each wheel and a mechanical connection member located between the leveling valve and the wear detection member of the wheel. The mechanical connection member is used to transmit the displacement of the wear detection member to the leveling valve to control an increase or decrease in the existing pressure in the secondary suspension device;

[0013] - Each wear detection member is hinged to the corresponding wheel near a first connection pivot, and the mechanical connection member is hinged to the leveling valve near a second connection pivot on the one hand and to the wear detection member of the wheel near a third movable connection pivot and a fourth rigid connection pivot on the other hand;

[0014] - Each wheel rotates about an axis, and wherein the wear detection member of the wheel detects the wear of the wheel through the displacement of the first connection pivot of the wear detection member of the wheel towards the axis of rotation of the wheel, and the displacement of the first connection pivot towards the axis of rotation of the wheel is caused by the reduction of the diameter of the wheel;

[0015] - The leveling valve is hinged to an arm extending between two longitudinal ends near a fifth connection pivot, and the arm is hinged to the mechanical connection member of the corresponding wheel at each longitudinal end near the second connection pivot;

[0016] - Regardless of the wear of the wheel, the distance in the height direction between the fourth rigid connection pivot and the axis of rotation of the wheel is substantially constant;

[0017] - The adjustable distance in the height direction between the second connection pivot and the axis of rotation of the wheel changes with the wear of the wheel;

[0018] - The wear detection member of the wheel is hinged to the vehicle frame through a connecting guide rail and includes a spring system located between the first connecting pivot and the fourth rigid connecting pivot, so that the wear detection member of the wheel can only translate in the height direction and the mechanical connecting member can rotate around the fourth rigid connecting pivot;

[0019] - The leveling valve is configured to compensate for the load change of the car body of the rail vehicle associated with the bogie by the following method: when the load increases, control the existing pressure in the secondary suspension device to increase, or when the load decreases, control the existing pressure in the secondary suspension device to decrease.

[0020] The present invention also relates to a car body of a rail vehicle, including at least one bogie according to the present invention. Description of the Drawings

[0021] Other aspects and advantages of the present invention become apparent by reading the following description given by way of example with reference to the sole drawing. In the drawings:

[0022] Figure 1 is a side view of the bogie of the present invention. Detailed Description of the Invention

[0023] In the following description, the terms "high" and "low" are understood according to the typical height direction Z of the rail vehicle. On a horizontal ground, the height direction Z is thus generally vertical.

[0024] See Figure 1 A description is given of the bogie 10 of the rail vehicle.

[0025] The bogie 10 includes two pairs of wheels 12.

[0026] Each pair of wheels 12 is connected to each other by an axle structure 14, and the axle structure 14 includes an axle box 16 for each wheel 12 in the corresponding pair of wheels.

[0027] The bogie 10 includes a vehicle frame 18. The vehicle frame is, for example, a hinged vehicle frame 18.

[0028] Each axle structure 14 is connected to the vehicle frame 18 through a primary suspension device 20. The primary suspension device 20 includes, for example, a coil spring or a pneumatic spring.

[0029] The primary suspension device 20 generally includes one or two springs for each wheel 12. In the illustrated example, the primary suspension device 20 includes a coil spring for each wheel 12. The coil spring extends in the height direction Z.

[0030] The primary suspension device 20 attenuates the vibration of the vehicle frame 18 of the bogie 10 relative to the wheels 12 in the height direction Z.

[0031] The bogie 10 includes a plurality of secondary suspension devices 22 carried on the car body 18. The secondary suspension devices 22 include, for example, coil springs or pneumatic springs. The secondary suspension devices 22 extend between the bogie 10 and the body 23 of the car body of the rail vehicle (as shown by the dashed line in Figure 1 as shown).

[0032] The bogie 10 has two longitudinal sides 24 extending along the longitudinal direction L.

[0033] Each longitudinal side 24 includes one wheel 12 of each pair.

[0034] The secondary suspension devices 22 generally include one or two springs for each longitudinal side 24.

[0035] In the illustrated example, the secondary suspension device 22 includes a pneumatic spring for the longitudinal side 24, generally located at the midpoint of the axis of rotation X of the wheel 12 on the longitudinal side 24.

[0036] The pneumatic spring extends in the height direction Z.

[0037] The secondary suspension device 22 attenuates the vibration of the body 23 of the car body relative to the bogie 10 in the height direction Z.

[0038] The secondary suspension device 22 includes at least one leveling valve 26 for each longitudinal side 24 of the bogie 10.

[0039] The leveling valve 26 of the longitudinal side 24 is connected on the one hand to a pressurized fluid storage tank (not shown), and on the other hand to the secondary suspension device 22 of the same longitudinal side 24.

[0040] The pressurized fluid is air, for example.

[0041] The leveling valve 26 includes a lever 28. The lever 28 is movable between a first limit position and a second limit position. The displacement of the lever 28 towards the first limit position causes the secondary suspension device 22 of the longitudinal side 24 where the leveling valve 26 is located to expand.

[0042] The expansion of the secondary suspension device 22 causes the floor of the car body placed on the bogie 10 to be displaced upwards in the height direction Z.

[0043] The displacement of the lever 28 towards the second limit position causes the secondary suspension device 22 of the longitudinal side 24 where the leveling valve 26 is located to contract.

[0044] The contraction of the secondary suspension device 22 causes the floor of the car body placed on the bogie 10 to be displaced downwards in the height direction Z.

[0045] In the example shown, the number of leveling valves 26 is two and they are symmetric about the longitudinal central axis of the vehicle frame 18, which is parallel to the longitudinal side portions 24 and located at the midpoint of the longitudinal side portions 24.

[0046] For each wheel 12, the bogie 10 includes a wear detection member 30 of the wheel 12 and a mechanical connection member 34. The wear detection member 30 is hinged to the wheel 12 near a first connection pivot 32, and the mechanical connection member 34 is located between the leveling valve 26 and the wear detection member 30 of the wheel 12.

[0047] The first connection pivot 32 between the wear detection member 30 and the wheel 12 is formed by a wheel-shaped portion having a diameter between 2% and 20% of the diameter of the wheel 12 where the first connection pivot 32 is located.

[0048] In the example shown, the first connection pivot 32 is located below the wheel 12 in the height direction Z and is in contact with the wheel 12.

[0049] The wear detection member 30 of the wheel 12 is hinged to the vehicle frame 18 through a connection guide 36. Such a connection guide 36 allows the wear detection member 30, and advantageously the first connection pivot 32, to translate in the height direction Z, but does not allow the wear detection member 30, and advantageously the first connection pivot 32, to move in the longitudinal direction L.

[0050] The wear detection member 30 of the vehicle 12 preferably does not have electronic components.

[0051] The mechanical connection member 34 is hinged to the leveling valve 26 near a second connection pivot 38 on the one hand, and is hinged to the wear detection member 30 of the wheel 12 near a third movable connection pivot 40 and a fourth rigid connection pivot 42 on the other hand.

[0052] In the example shown, the mechanical connection member 34 generally forms a "Z" shape, and its end branches lead the second connection pivot 38 to the leveling valve 26 on the one hand, and lead the third movable connection pivot 40 to the wear detection member 30 on the other hand.

[0053] The mechanical connection member 34 rotates about the rigid connection pivot 42 and about an axis perpendicular to the longitudinal direction L and the height direction Z.

[0054] Preferably, the wear detection member 30 of the wheel 12 includes a helical spring 44 located between the first connection pivot 32 or the wear detection member 30 and the fourth rigid connection pivot 42. The helical spring 44 extends in the height direction Z.

[0055] Therefore, the wear detection member 30 of the wheel 12 moves the connection guide 36 and only translates in the height direction Z, and the fourth rigid connection pivot 42 maintains a constant distance D from the rotation axis X of the wheel 12 above which the rigid connection pivot 42 is located.

[0056] Preferably, the wear detection member 30 and the mechanical connection member 34 on the same longitudinal side 23 are symmetrical about the vertical central axis of the vehicle frame 18, which is perpendicular to the longitudinal side 24 and located at the midpoint of the rotation axis X of the wheel 12 corresponding to the longitudinal side 24.

[0057] Each leveling valve 26 is hinged to the arm 48 near the fifth connection pivot 46, and the arm 48 extends between two longitudinal ends 50, 52.

[0058] Preferably, the fifth connection pivot 46 between the leveling valve 26 and the arm 48 is generally arranged at an equal distance from each second connection pivot 38 on each mechanical connection member 34 that hinges the arm 48 to the same longitudinal side 24 of the bogie 10.

[0059] This setting of the fifth connection pivot 46 allows compensation for the average wear of the wheel 12 on the longitudinal side 24.

[0060] The arm 48 hinges each of the longitudinal ends 50, 52 to the mechanical connection member 34 of the corresponding wheel 12 near the second connection pivot 38.

[0061] The arm 48 is preferably telescopic. This enables a small relative longitudinal movement between multiple axle boxes 16 during travel.

[0062] An adjustment distance a is defined in the height direction Z between the second connection pivot 38 and the rotation axis X of the corresponding wheel 12. The adjustment distance a varies according to the diameter of the wheel 12 and thus according to the wear of the wheel 12.

[0063] The function of the bogie 10 according to the present invention will be described below.

[0064] When one of the wheels 12 wears, its diameter decreases, causing the first connection pivot 32 to move towards the rotation axis X of the wheel 12.

[0065] In particular, the first connection pivot 32 moves towards the arm in the height direction Z.

[0066] Through the displacement of the connecting guide 36 and by expanding the helical spring 44 so that the fourth rigid connection pivot 42 remains at a constant distance D from the rotation axis X of the wheel 12 on which the fourth rigid connection member 42 is placed, the wear detection member 30 corresponding to the wheel 12 is translated towards the arm in the height direction Z.

[0067] The displacement of the first connection pivot 32 towards the arm in the height direction Z causes the mechanical connection member 34 to rotate and displace about the fourth rigid connection pivot 42.

[0068] When the mechanical connecting member 34 rotates and displaces about the fourth connecting pivot 42, the mechanical connecting member 34 causes the corresponding second connecting pivot 38 to displace upward in the height direction Z.

[0069] The adjustment distance a increases. The upward displacement of the corresponding second connecting pivot 38 causes the arm 48 to tilt.

[0070] The tilt of the arm 48 in turn causes the fifth connecting pivot 46 to displace upward in the height direction Z, which causes the lever 28 of the leveling valve 26 to displace upward.

[0071] The upward displacement of the lever 28 controls an increase in the existing pressure in the auxiliary suspension device 22 on the same longitudinal side 24. The pressurized fluid contained in the storage tank is injected into the auxiliary suspension device 22 to cause the auxiliary suspension device 22 to expand.

[0072] The floor of the carriage placed on the bogie 10 is then raised to compensate for the height drop caused by the wear of the wheels, thus facilitating the boarding and alighting of passengers, especially those with limited mobility.

[0073] The change in the load of the carriage is also compensated by the leveling valve 26. The leveling valve 26 preferably injects pressurized fluid into the suspension device 22 when the load increases by displacing the lever 28, thereby controlling an increase in the existing pressure in the suspension device 22; or sucks the pressurized fluid out of the suspension device 22 when the load decreases, thereby reducing the existing pressure in the suspension device 22.

[0074] Thereby, the comfort of the passengers is improved.

[0075] The bogie 10 according to the present invention also enables the maintenance cost due to the wear of the wheels 12 to be reduced and calibration is not required.

[0076] In addition, the wheel wear detection member, the mechanical connecting member 34, and the arm 48 are completely mechanical, and the adjustment of the height of the auxiliary suspension does not require electronic components and power supply.

Claims

1. A bogie (10) of a rail vehicle, comprising: a) two pairs of wheels (12), each pair of wheels (12) being connected to each other by an axle structure (14); b) a hinged frame (18), each axle structure (14) being connected to the hinged frame (18) by a main suspension device (20); and c) a secondary suspension device (22) carried on the hinged frame (18), the secondary suspension device (22) including at least one leveling valve (26); characterized in that the bogie (10) further comprises: - for at least one of the wheels (12), a wear detection member (30) of the wheel (12) and a mechanical connection member (34) located between the leveling valve (26) and the wear detection member (30) of the wheel (12), the mechanical connection member being used to transmit the displacement of the wear detection member to the leveling valve to control an increase or decrease in the existing pressure in the secondary suspension device (22); and each wear detection member is hinged to the corresponding wheel (12) near a first connection pivot (32), and the mechanical connection member (34) is hinged to the leveling valve (26) near a second connection pivot (38) and is hinged to the wear detection member (30) of the wheel near a third movable connection pivot (40) and a fourth rigid connection pivot (42).

2. The bogie (10) according to claim 1, wherein, the bogie (10) has two longitudinal sides (24), each longitudinal side (24) including one wheel (12) of each pair of wheels, the secondary suspension device (22) includes at least one leveling valve (26) on each longitudinal side (24) of the bogie (10), the bogie includes a wear detection member for each wheel and a mechanical connection member (34) located between the leveling valve (26) and the wear detection member (30) of the wheel (12), the mechanical connection member being used to transmit the displacement of the wear detection member to the leveling valve to control an increase or decrease in the existing pressure in the secondary suspension device (22).

3. The bogie (10) according to claim 1 or 2, wherein, each wheel (12) rotates about a rotation axis (X), and wherein the wear detection member (30) of the wheel (12) detects the wear of the wheel (12) by the displacement of the first connection pivot of the wear detection member of the wheel towards the rotation axis (X) of the wheel, the displacement of the first connection pivot towards the rotation axis of the wheel being caused by a reduction in the diameter of the wheel (12).

4. The bogie (10) according to claim 1 or 2, wherein, the leveling valve (26) is hinged near a fifth connection pivot (46) to an arm (48) extending between two longitudinal ends (50, 52), and the arm (48) is hinged to the mechanical connection member (34) of the corresponding wheel (12) at each longitudinal end (50, 52) near the second connection pivot (38).

5. The bogie (10) according to claim 1 or 2, wherein, irrespective of the wear of the wheel (12), the distance (D) in the height direction (Z) between the fourth rigid connection pivot (42) and the rotation axis (X) of the wheel (12) is substantially constant.

6. The bogie (10) according to claim 1 or 2, wherein, the adjustment distance (a) in the height direction between the second connection pivot (38) and the rotation axis (X) of the wheel (12) varies with the wear of the wheel (12).

7. The bogie (10) according to claim 1 or 2, wherein, the wear detection member (30) of the wheel (12) is hinged to the articulated frame (18) through a connecting guide rail (36) and includes a spring system (44) located between the first connection pivot and the fourth rigid connection pivot (42), so that the wear detection member (30) of the wheel (12) translates only in the height direction (Z) and the mechanical connection member (34) rotates about the fourth rigid connection pivot (42).

8. The bogie (10) according to claim 1 or 2, wherein, the leveling valve is configured to compensate for the change in the load of the car body of the rail vehicle associated with the bogie by controlling the existing pressure in the auxiliary suspension device to increase when the load increases, or controlling the existing pressure in the auxiliary suspension device to decrease when the load decreases.

9. A car body of a rail vehicle, characterized in that, the car body has at least one bogie (10) according to claim 1.

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