Railway vehicle truck

Abstract

To provide a railway vehicle truck that reduces lateral steady-state acceleration acting on passengers when the railway vehicle passes through a curved line and enables improvement in ride comfort.SOLUTION: In a railway vehicle truck, a negative stiffness element having a negative spring constant that reduces spring force as lateral displacement between a vehicle body and the truck increases is arranged vertically below an air spring device and at a central position of the truck in the rail direction.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to a bogie for a railway vehicle that reduces steady lateral acceleration acting on passengers when the railway vehicle traverses a curved section, thereby improving ride comfort. [Background technology]

[0002] A typical railway vehicle consists of one car body and two bogies, and air springs are installed between the car body and the bogies, providing elastic support in each direction: front-back, left-right, and up-down. The height of the elastic support in the left-right direction of this air spring is offset from the height of the car's center of gravity, so when a left-right force such as centrifugal force acts on the car's center of gravity, the car body displaces around the axis in the rail direction relative to the track cant surface (hereinafter, the displacement around the axis in the rail direction is called roll displacement).

[0003] Generally, when a railway vehicle travels at high speed on a curved section, centrifugal force acts on the car body, causing the car body to roll toward the outer track of the curve. In this case, the steady-state acceleration in the lateral direction felt by passengers on the curved section is calculated by subtracting the acceleration component of gravity acceleration x (track cant angle - car body roll displacement) from the centrifugal acceleration, which is uniquely determined by the curve radius and speed. If the car body roll displacement becomes large, the effect of reducing the centrifugal acceleration by the track cant is reduced. If this causes the steady-state acceleration in the lateral direction felt by passengers to increase, passengers will perceive a sensation of being pulled in the lateral direction, which will impair the ride comfort. Therefore, in order to improve the ride comfort when passing through curves, it is important for railway vehicles to reduce the car body roll displacement caused by the car body tilting outward toward the outer track of the curve.

[0004] One method for suppressing carbody roll displacement is to increase the elastic support stiffness in the roll direction between the carbody and the bogie, and a method for controlling the characteristics of the air spring of the elastic support element between the carbody and the bogie when passing through a curve is described, for example, in Patent Document 1. In addition, Non-Patent Document 1 presents the idea of ​​arranging a negative stiffness element in the left-right direction between the carbody and the bogie. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2010-264964 A [Non-patent literature]

[0006] [Non-Patent Document 1] Proceedings of the 72nd Annual General Meeting of the Japan Society of Mechanical Engineers [IV] "Analysis of Rolling Characteristics of a Car Body Combined with a Negative Characteristic Spring" (1995.3.28~1995.3.31 Tokyo) Summary of the Invention [Problem to be solved by the invention]

[0007] The railcar described in Patent Document 1 is configured to include a servo valve that inhales and exhales air to an air spring provided between the car body and the bogie, a controller that controls the servo valve, a displacement sensor that measures the relative displacement between the car body and the bogie, and an acceleration sensor that measures the vertical acceleration of the car body. The configuration is such that the state of the vertical spring constant of the air spring can be changed by feeding back the mounted sensor information. For example, in curved sections, the feedback control system increases the vertical spring constant of the air spring to increase the rigidity in the roll direction between the car body and the bogie, thereby suppressing the roll displacement of the car body and improving the ride comfort when passing through curved sections. However, in the above configuration, it is necessary to add a control system that gives an intake and exhaust command to the air spring to the conventional bogie configuration, which makes the vehicle system including the control system complicated.

[0008] In the railway vehicle described in Non-Patent Document 1, it has been shown by numerical analysis that it is possible to change the roll characteristics of the vehicle by arranging a negative stiffness element in the left-right direction between the carbody and the bogie. However, there is no mention of a specific mounting structure for the vehicle that takes into consideration the ease of installation and removal of the negative stiffness element, the effect on the steering performance of the bogie when passing through curves, and other factors.

[0009] Therefore, the present invention provides a bogie for railway vehicles that has a passive bogie configuration that does not require the installation of an additional control device, improves operability such as the attachment and detachment of components related to the present invention, and makes it possible to suppress car body roll displacement when passing through curves without adversely affecting the maneuverability of the bogie when passing through curves. [Means for solving the problem]

[0010] In order to solve the above problems, a negative stiffness element having a negative spring constant whose spring force decreases as the lateral displacement between the carbody and the bogie increases is disposed below the air spring device and at the center position of the bogie in the rail direction in a railway vehicle bogie. Effect of the Invention

[0011] According to the present invention, it is possible to improve the ease of installation and removal of components related to the present invention without installing a new control device on the bogie, and it is also possible to suppress body roll displacement when passing through curves without adversely affecting the maneuverability of the bogie when passing through curves. [Brief description of the drawings]

[0012] [Figure 1] FIG. 1 is a side view of a vehicle including a railcar bogie according to a first embodiment. [Diagram 2] FIG. 2 is a top view of the railway vehicle bogie of the first embodiment. [Diagram 3] FIG. 3 is a front view of the inventive mechanism and its surroundings of the railcar bogie of the first embodiment. [Figure 4] FIG. 4 is a schematic diagram showing the action of forces on the railway vehicle bogie of the first embodiment when the railway vehicle bogie runs on a curved track. [Diagram 5] FIG. 5 is a front view of the periphery of the inventive mechanism of the railway vehicle bogie according to the second embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS EXAMPLES

[0013] A first embodiment of the present invention will be described below with reference to FIGS.

[0014] FIG. 1 shows a side view of a vehicle including a railcar bogie (hereinafter also simply referred to as bogie) 16 of the present invention.

[0015] In FIG. 1, the railway vehicle of the present invention is made up of a car body 1 and a bogie 16 .

[0016] The bogie 16 is mainly composed of a bogie frame 3, an axle box 2, a wheel set 4, and an axle box suspension 6. The wheel set 4 is rotatably held relative to the axle box 2, and the axle box 2 is elastically supported between the bogie frame 3 and the bogie frame 3 by the axle box suspension 6. There are various types of axle box suspension 6, but any type may be used in the present invention. The car body 1 and the bogie frame 3 are elastically supported via an air spring 30, a traction device 43 one end of which is fixed to a center pin 41 fixed to the car body 1, and a negative stiffness element 100.

[0017] FIG. 2 shows a top view of the railcar bogie 16 of the present invention.

[0018] 2, the negative stiffness element 100 is disposed below the connecting beam 19 of the bogie frame 3 (the rear side in the direction perpendicular to the page), between the center pin 41, at the center of the bogie 16 in the rail direction, and in a direction perpendicular to the rail 7. Although not shown in this figure, a configuration in which left and right dampers are disposed may be used to obtain a damping effect in the left and right directions of the car body 1 and the bogie 16.

[0019] FIG. 3 shows a front view of the inventive mechanism and its surroundings of the bogie 16 for a railway vehicle according to the present invention.

[0020] In FIG. 3, the vehicle body support device 40 is mainly composed of a center pin 41, an air spring 30, a negative stiffness element 100, a bracket 42, and a traction device 43.

[0021] Negative stiffness element 100 is disposed vertically below air spring 30, between center pin 41 fastened to carbody 1 and bracket 42 provided vertically below tie beam 19 of bogie frame 3. In the present invention, air spring 30 is assumed to be used in combination with negative stiffness element 100, and is a commonly used air spring that can achieve a positive spring constant in which the spring force increases with increasing lateral displacement, in other words, when stroked in the lateral extension direction, a force is generated in a direction to return the extension.

[0022] The negative stiffness element 100 is configured with a rubber bellows 103 between an annular outer cylinder 101 with both ends opening outward in an inverted V-shape and a cylindrical inner cylinder 102 with both ends narrowing in a V-shape and a cross section rotated in the circumferential direction. The outer cylinder 101 is configured to extend to the left with a constant circumference from the position where the circumference of the ring is larger due to the outward opening on the left side in this figure, and is disk-shaped at the left end 104. The rubber bellows 103 is configured to contain compressed air. The rubber bellows 103 may be connected to an external air supply source or may be configured to contain compressed air in advance. The right end of the inner cylinder 102 of the negative stiffness element 100 in this figure is fixed to the center pin 41 fixed to the car body 1, and the left end 104 of the outer cylinder 101 in this figure is fixed to the bracket 42 fixed to the lower part of the tie beam 19 of the bogie frame 3 with bolts or the like. With this configuration, when relative displacement occurs at both ends of the negative stiffness element 100, the outer tube 101 becomes displaced relative to the inner tube 102 in the left-right direction, changing the positional relationship between the V-shaped portion of the outer tube 101 and the V-shaped portion of the inner tube 102. As a result, the pressure-receiving area in a cross section perpendicular to the stroke of the rubber bellows 103 increases at one end of the rubber bellows 103 and decreases at the other end, so that when a stroke is made in the extension direction, a force is generated in a direction that promotes extension, thereby realizing a negative spring constant.

[0023] In this embodiment, a negative spring constant is realized by disposing a rubber bellows 103 filled with compressed air between the metal plates of the outer cylinder 101 and the inner cylinder 102, but a negative spring constant may also be realized by, for example, dividing the inside of the air cylinder into two air chambers and lowering the pressure in one of the air chambers in conjunction with the stroke of the cylinder, thereby utilizing the pressure difference between the two air chambers. A negative spring constant may also be realized by a laminated structure of metal plates and rubber.

[0024] FIG. 4 is a schematic diagram showing the action of forces on the railway vehicle of the present invention when the vehicle runs on a curved track.

[0025] The operation and effect of the present invention will be described by explaining the balance of forces in the left and right translational directions and the balance of moments in the roll rotational direction with reference to FIG.

[0026] First, the balance of forces in the left and right translation directions will be described.

[0027] When a railway vehicle travels on a curved section, centrifugal force (F) acts on the center of gravity of the car, biasing the carbody 1 toward the outer curved track. As a result, the air springs 30 each exert a force (Fa) in a direction that pulls the carbody 1 back toward the inner curved track on the left and right, and the negative stiffness elements 100 exert a force (Fy) in a direction that pushes the carbody 1 toward the outer curved track. These four forces (F, two Fas, and Fy) are balanced in the left and right translational directions.

[0028] Next, the balance of the moment in the roll rotation direction will be described.

[0029] When a railway vehicle travels on a curved section, a moment (F×H) obtained by multiplying the acting height of the centrifugal force (F), which is the position of the car's center of gravity, and the height offset (H) between the roll center height 103 (shown by a triangle), acts clockwise in FIG. 4, that is, in a direction that causes the carbody 1 to lean outward toward the outer rail of the curve. The acting height of the lateral translational force (Fa) of the air spring 30 is the same as the roll center height 103, so no moment due to this force acts. A moment (Fy×J) obtained by multiplying the acting height of the lateral translational force (Fy) of the negative stiffness element 100 and the height offset (J) between the roll center height 103 (shown by a triangle), acts counterclockwise in FIG. 5, that is, in a direction that restores the carbody 1 from leaning outward toward the outer rail of the curve.

[0030] From the viewpoint of balance of moments, the outward tipping moment (F×H) due to the centrifugal force (F) is reduced by the action of a moment (Fy×J) that restores the outward tipping caused by the left and right translational force (Fy) of the negative stiffness element 100. Taking into consideration the effect of this restoring moment, the outward tipping moment ((F×H)-(Fy×J)) on the carbody 1 is countered by a counterclockwise moment caused by a vertical force (Fz) acting in opposite directions on the left and right pair of air springs 30, which is generated when the carbody 1 is displaced by rolling towards the outer rail, thereby maintaining balance of the moment in the roll rotation direction. Because the outward tipping moment on the carbody 1 is reduced by the effect of the restoring moment caused by the negative stiffness element 100, the necessary counter moment can be applied with a small carbody roll displacement.

[0031] As described above, in the bogie system of the present invention, a moment can be applied to restore the outward tipping caused by the lateral translational force of the negative stiffness element 100, thereby reducing the outward tipping moment on the carbody 1 when passing through a curved section. This reduces the burden of the air spring's vertical force to counter the outward tipping moment, thereby reducing the air spring's vertical stroke and reducing the carbody roll displacement when passing through a curved section. This reduces the steady-state acceleration in the lateral direction acting on passengers, improving the ride comfort in curved sections. Even when stopping in a curved section, the steady-state acceleration in the lateral direction on passengers can be reduced by the same operation as the mechanism described here.

[0032] Next, other effects of the present invention will be described. First, even if the negative stiffness element 100 generates a lateral translational force (Fy) when passing through a curve, as shown in FIG. 2, the negative stiffness element 100 is arranged on the same line as the center position of the bogie 16 in the turning direction, so that the configuration does not adversely affect the steering performance of the bogie 16. This allows the suspension design for suppressing the roll displacement of the car body and the suspension design for improving the steering performance of the bogie 16 to be independent. Second, since the negative stiffness element 100 is arranged below the bogie frame 3 as shown in FIG. 3, even if the car body 1 and the bogie 16 are connected to each other, for example, the negative stiffness element 100 is easily accessible from below the pit of the vehicle depot, and the workability of attachment and detachment can be improved.

[0033] In the explanation of the operation and principle in FIG. 4, the mechanism of suppressing the roll displacement of the car body is explained, so the influence of the magnitude of the spring constant in the lateral direction of the air spring 30 is not mentioned. The larger the spring constant in the lateral direction, the more the air spring lateral translational force (Fa) can be generated with a smaller displacement, so that the deviation of the car body 1 toward the curved outer rail can be suppressed to a small extent. This is effective in, for example, ensuring the clearance between the vehicle and infrastructure structures and preventing the pantograph from coming off the rail. For this reason, the air spring 30 may be an air spring whose spring constant increases with an increase in the displacement in the lateral direction. EXAMPLES

[0034] FIG. 5 shows a front view of the periphery of the inventive mechanism according to the second embodiment of the present invention.

[0035] The second embodiment has the same configuration as the first embodiment, except that the negative stiffness element 100 is configured to extend in the longitudinal direction and that the mounting position on the bogie frame 3 side is a bracket provided on the side beam 20 of the bogie frame 3. In addition to the effects described in the first embodiment, other effects of the second embodiment will be described.

[0036] When a railway vehicle is traveling, a relative vertical displacement occurs between the carbody 1 and the bogie 16 due to forced displacement vibration from the track, etc. When this relative vertical displacement occurs, the position of one end of the negative stiffness element 100 is displaced vertically with respect to the other end, so that an angular displacement (vertical displacement amount / distance) occurs in the inner tube 102 relative to the outer tube 101 about an axis perpendicular to the page. If this angle is large, the amount of deformation caused by the twisting of the rubber bellows 103 becomes large. In the second embodiment in which the mounting length is increased, this angle can be made small, so that the torsional load on the rubber bellows 103 can be reduced and the durability of the negative stiffness element 100 can be improved.

[0037] The present invention is not limited to the above-described embodiment, and can be implemented using any components without departing from the spirit of the present invention.

[0038] The above-mentioned embodiments and modifications are merely examples, and the present invention is not limited to these contents as long as the characteristics of the invention are not impaired. In addition, although various embodiments and modifications have been described above, the present invention is not limited to these contents. Other aspects that are conceivable within the scope of the technical idea of ​​the present invention are also included in the scope of the present invention. [Explanation of symbols]

[0039] 1... car body, 2... axle box body, 3... bogie frame, 4... wheel set, 6... axle box support device, 7...rail, 16...cart, 19...connecting beam, 20...side beam, 30...air spring, 40...vehicle body support device, 41...center pin, 42...bracket, 43...traction device, 100...negative stiffness element, 101...outer cylinder, 102...inner cylinder, 103...rubber bellows, 104...outer cylinder end

Claims

1. In railroad car bogies, Vertically below the air spring device, and At the center of the carriage in the rail direction, A negative spring constant in which the spring force decreases as the lateral displacement of the car body and bogie increases A negative stiffness element with A bogie for a railway vehicle.

2. The railcar bogie of claim 1, The air spring device is an elastic element whose spring constant increases with increasing lateral displacement. Equipped A bogie for a railway vehicle.

3. In the railroad vehicle bogie according to claim 1 or 2, Both ends of the negative stiffness element are connected to the center pin device on one side and the bogie frame connecting beam on the other side. Arranged via a member installed vertically below A bogie for a railway vehicle.

4. In the railroad vehicle bogie according to claim 1 or 2, The negative stiffness element has two ends, one connected to the center pin device and the other to the side beam of the bogie frame. Arranged via a member installed vertically below A bogie for a railway vehicle.

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