JP2015016709A - Bogie for railway vehicle, railway vehicle and railway system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a bogie for a railway vehicle which is improved in traveling stability and curve passing performance, the railway vehicle and a railway system.SOLUTION: An axle 6 is inclined so as to become high at the outside and low at the inside when viewed from a front face, and a wheel 7 which is rotatably supported by the axle 6 is composed of a cylindrical tread 7a and a flange 7b which continues to an outside end of the tread 7a. A contact angle θ in a vertical plane is formed between the tread 7a and rails in a state that the cylindrical tread 7a of the wheel 7 contacts with the rails. A gravity return force is generated by the contact angle θ toward the outside, the steering moment in a direction in which a yaw angle is reduced is generated by the gravity return force, and traveling stability is secured.

Description

  TECHNICAL FIELD The present invention relates to a railway vehicle carriage provided with left and right wheel units composed of an axle and wheels, and a railway vehicle and railway system composed of this carriage and a vehicle body, and has excellent sharp curve passing performance such as for an LRT (Light Rail Transit) vehicle. It relates to what requires special characteristics.

Railway vehicles are required to have curve-passing performance and running stability, and the curve-passing performance is exhibited by a self-steering function based on the tread gradient of the wheels. The self-steering function can be enhanced by freeing the turning movement (yawing) of the wheel shaft. However, if the turning movement of the wheel shaft is made free, a snake action which is a self-excited vibration is generated and the running stability is hindered.

Regarding this self-steering function, an independent rotating carriage provided with wheel units (axles and wheels) that can independently rotate on the left and right of the carriage frame of the carriage is excellent.
However, when a yaw angle is generated in the carriage, a reverse steering moment acts in a direction that increases the yaw angle, and therefore, it becomes unstable as with an inverted pendulum. Therefore, in this type of self-steering carriage, the yaw angle is prevented from increasing by the flange portion provided on the wheel, and in some cases, a moment is forcedly applied in the restoring direction using an actuator. Or by turning the wheel center of rotation in the yaw direction outside the contact point between the tread and the rail, the inverted pendulum mechanism is changed to the upright pendulum mechanism and stabilized by inward gravity restoring force. The self-steering function has been demonstrated.

However, when turning on a route with an extremely small radius of curvature such as LRV (Light Rail Transit), due to the characteristics of the steering link mechanism, the back gauge of the wheels on both sides is reduced and the difference in the curve radius of the inner and outer gauge rails Since the disadvantage that an ideal curve cannot be swung with a zero attack angle cannot be eliminated, the present inventors have previously proposed Patent Document 1 and Non-Patent Document 1.

Japanese Patent No. 5051771

The International Journal of Railway Technology Vol.1 2012 p1-26

According to the reverse tread wheel unit disclosed in Patent Document 1 and Non-Patent Document 1, even if the radius of curvature is smaller than that of a conventional independently rotatable wheel unit, smooth curved traveling can be realized, and there is a risk of derailment. And the wear of rails and wheels can be reduced.
However, it has been found that there is room for improvement in terms of running stability because the wheels are likely to yaw near the streetcar operating speed (40 km / h).

In order to solve the above-described problem, the cart according to claim 1 is provided with wheel units each including an axle and wheels on the left and right sides, and the left and right axles constituting the wheel unit are configured such that the inside is high and the outside is low when viewed from the front. The left and right wheels that are inclined and rotatably supported by these axles have a configuration in which a flange is formed on the outside as viewed from the front and an upper portion is inclined outward.
That is, the left and right wheels of the carriage according to claim 1 are positive cambers used in the field of automobiles.

In order to solve the above-mentioned problem, the cart according to claim 2 is provided with a wheel unit composed of an axle and wheels on the left and right sides, and the left and right axles constituting the wheel unit are so that the outside is high and the inside is low when viewed from the front. The left and right wheels that are inclined and rotatably supported by these axles have a configuration in which a flange is formed on the inner side and the upper part is inclined inward as viewed from the front.
That is, the left and right wheels of the carriage according to claim 2 are negative cambers used in the field of automobiles.

  In the above-described railcar bogie, the axle is inclined so that a contact angle is generated between the rail surface and the gravity restoring force increases, but by making the wheel shape cylindrical, the contact angle with the rail surface is It is formed more clearly and a large gravity restoring force is obtained.

  It is also possible to connect the left and right axles with a link and operate this link to increase the restoring force. The left and right axles are integrated without being separated, for example, both ends for rotatably supporting the wheels. It may be a single axle with an inclined portion.

  Furthermore, a railway vehicle in which the above-described railway vehicle carriage is incorporated, and a railway system including the railway vehicle and a rail are also objects of the present application.

In the railcar bogie according to the present invention, a contact angle is formed with the rail surface by inclining an axle that rotatably supports wheels in a vertical plane, and a gravity restoring force is generated by the contact angle.

As a result, the running stability is greatly improved in comparison with a cart provided with an independent rotating wheel having a reverse tread surface as well as a cart provided with a conventional independent rotating wheel.

In particular, the running stability in the vicinity of the operating speed (40 km / h), which is regarded as a problem for a carriage having independent rotating wheels with reverse treads, is greatly improved.

Side view of a railway vehicle to which the railway vehicle carriage according to the first embodiment is applied. Front view of a railcar bogie according to the first embodiment The top view of the bogie for rail vehicles which concerns on 1st Example Plan view of the track used in the attack angle experiment The graph which compared the performance regarding the attack angle of the bogie for rail vehicles which concerns on 1st Example, and the bogie disclosed by patent document 1 (A) is a graph showing the relationship between the yaw attenuation coefficient and the critical speed of the bogie for the railway vehicle according to the first embodiment, and (b) shows the relationship between the yaw attenuation coefficient of the bogie disclosed in Patent Document 1 and the critical speed. Graph showing Front view of a railcar bogie according to the second embodiment The top view of the bogie for rail vehicles which concerns on 2nd Example. The graph which shows the relationship between the speed and the frequency of the bogie for rail vehicles which concerns on 2nd Example. (A-1) is a graph (b-1) showing the relationship between the time and the lateral displacement of the railcar bogie according to the second embodiment. The graph (b-1) is the time and yaw angle of the railcar bogie according to the second embodiment. The graph (a-2) showing the relationship is the graph (b-2) showing the relationship between the time and the lateral displacement of the railway vehicle carriage disclosed in Patent Document 1, and the graph (b-2) of the railway vehicle carriage disclosed in Patent Document 1 is shown. Graph showing the relationship between time and yaw angle Front view of a railcar bogie according to the third embodiment Graph showing the relationship between speed and frequency of the third embodiment

The best mode for carrying out the present invention will be described below in detail with reference to the drawings.
As shown in FIG. 1, the front and rear carriages 1, 1 have a carriage frame 2, and a railway vehicle 4 is supported on the carriage frame 2 via a bolsterless air spring 3.

A wheel unit 5 is supported on the carriage frame 2. The wheel unit 5 includes an axle 6 and left and right wheels 7 and 7, and a coil spring 9 is disposed between the axle box 8 that supports the axle 6 and the carriage frame 2.

As shown in FIGS. 2 and 3, the axles 6 that rotatably support the wheels 7 and 7 are arranged on the left and right sides, and the left and right axles 6 and 6 are integrally coupled by a connecting portion 10. Note that the left and right axles 6 and 6 and the connecting portion 10 may be configured by a single shaft.

Between the outer end of the axle 6 and the front part of the bogie frame 2, dampers 11 and 11 for suppressing yawing (serpentine behavior) are arranged so that the axis is in the front-rear direction.

Further, the left and right axles 6 are inclined so that the outside is low and the inside is high when viewed from the front, and the wheels 7 that are rotatably supported by the axle 6 are formed on a cylindrical tread 7a and an outer end of the tread 7a. A continuous flange 7b is provided.

In a state where the cylindrical tread surface 7a of the wheel 7 is in contact with the rail R, a contact angle θ in the vertical plane is generated between the tread surface 7a and the rail R. Gravity restoring force is generated outward by the contact angle θ, and a steering moment in a direction to decrease the yaw angle is generated by the gravity restoring force, so that traveling stability is achieved.

FIG. 4 is a plan view of the track used in the attack angle experiment. Using this experimental apparatus, the curve passing performance of the railcar bogie according to the first example was measured.
As shown in FIG. 5, the measurement result shows that an ideal curve traveling with an attack angle of zero can be realized except for the bend introduction portion. Further, the attack angle of the bend introduction part is dramatically improved as compared with the conventional cart, and a result comparable to that of the independent rotating cart with the reverse tread surface disclosed in Patent Document 1 was obtained.

FIG. 6A is a graph showing the relationship between the yaw attenuation coefficient and the critical speed of the bogie for the railway vehicle according to the first embodiment, and FIG. 6B shows the yaw attenuation coefficient and the critical speed of the bogie disclosed in Patent Document 1. It can be seen that the carriage according to the present invention does not generate yawing vibration up to a traveling speed that is one digit higher than that of the independent rotating carriage with the reverse tread surface disclosed in Patent Document 1.

FIG. 7 is a front view of a railway vehicle carriage according to the second embodiment, and FIG. 8 is a plan view of the railway vehicle carriage according to the second embodiment. In this embodiment, one axle 6 and One wheel 7 constitutes the wheel unit 5.

That is, the axle box 8 is provided on the left and right sides of the carriage frame 2 so as to be rotatable around a vertical axis, and the outer end portion of the axle 6 is attached to the axle box 8.
In this second embodiment, the axle 6 is inclined so that the outside is high and the inside is low when viewed from the front, and the left and right wheels 7, 7 that are rotatably supported by these axles 6, 6 are cylindrical. A tread surface 7a to be formed and a flange 7b continuous to the inner end of the tread surface 7a are provided.

The axle boxes 8 and 8 are provided with levers 12 and 12 that form an angle of 90 ° with the axle 6 in a horizontal plane, and the levers 12 and 12 are connected by a link 13. As a result, the yaw angles of the left and right axles 5 are equal.

Even in the second embodiment, a contact angle θ in the vertical plane is generated between the tread surface 7a and the rail R in a state where the cylindrical tread surface 7a of the wheel 7 is in contact with the rail R. Gravity restoring force is generated inward by the contact angle θ, and a steering moment is generated in a direction to decrease the yaw angle by the gravity restoring force, so that traveling stability is achieved.

Factors that should be considered in terms of mechanics in the wheel unit include longitudinal creep force, gravity restoring force, and gyro effect. The following (Table 1) shows the longitudinal creep force, gravity restoring force and gyro effect for the second embodiment.

The vertical creep force generated by an independent rotating wheel is a force generated to keep the inertia due to wheel rotation constant when the wheel radius changes. For example, the vertical creep force is the lateral movement speed of the wheel unit (wheel axle). Occurs when the wheel radius changes proportionally. Note that the longitudinal creep force generated by the independent rotating wheel disappears because the number of rotations changes after a while from the change of the wheel radius.
When instantaneous vertical creep force is generated in the direction (anti-steering) that increases the yaw angle, the running stability is hindered.
As is apparent from the table, since the cylindrical tread surface 7a is used in the second embodiment, even if the wheel unit moves in the lateral direction, the wheel radius does not change, so no vertical creep force is generated.

FIG. 9 is a graph showing the relationship between the speed and the frequency when the inclination γ _O of the tread is 1/10, 0 (cylindrical) and −1/10 (reverse tread), and the solid line indicates stable vibration and dotted lines. The part represents unstable vibration. The cylindrical tread does not generate a steering moment due to the vertical creep force, but the tilting of the shaft causes a slight increase in the vibration frequency due to the steering-moment restoring force as the speed increases due to the gyro effect. In the case of a normal inclined tread surface, it can be seen that the restoring force due to the steering moment increases as the speed increases due to the vertical creep force and the gyro effect, so that the frequency increases.

In the reverse treadmill shown in Patent Document 1, the longitudinal creep force in the counter-steering direction is affected as the traveling speed increases, and the characteristic of becoming unstable eventually appears while the frequency decreases. For this reason, the wheel cannot travel in the neutral position and travels with the flange always in contact with the rail.
In order to improve this, it is preferable to increase the frequency to such an extent that the damper functions.

FIG. 10 shows the relationship between the time and left-right displacement and the relationship between the time and the yaw angle of the railcar bogie according to the second embodiment and the railcar bogie disclosed in Patent Document 1 using simulation software (SIMPACK). The railcar bogie according to the second embodiment is provided with a condition that there is no support rigidity by the spring, the yaw damper 500 Nms, and the speed 45 m / s, and the railcar bogie disclosed in Patent Document 1 is based on the spring. No support stiffness, 500 Nms of yaw damper, speed 10 m / s.
When these are compared, it can be seen that the traveling stability of the cart according to the present invention is greatly improved as compared with the conventional reverse tread surface independent rotating cart.

FIG. 11 is a front view of a railcar bogie according to a third embodiment. This third embodiment has the same basic configuration as the first embodiment, but instead of a cylindrical tread, a forward slope tread 7c A reverse slope tread 7d is formed.
The longitudinal creep force, gravity restoring force, and gyro effect for this example are shown in Table 2 below.

  In this embodiment, a force in the direction of increasing the yaw angle is generated by the gyro effect, but the above force can be canceled by the tread surface creep force. Therefore, as shown in FIG. 12, the vibration frequency increases as the speed increases, and running stability at high speed can be achieved by combining with the yaw damper.

  The railcar bogie according to the present invention can be suitably applied to LRV (Light Rail Transit), but is not limited thereto.

DESCRIPTION OF SYMBOLS 1 ... Bogie, 2 ... Bogie frame, 3 ... Spring, 4 ... Railway vehicle, 5 ... Wheel unit, 6 ... Axle, 7 ... Wheel, 7a ... Cylindrical tread, 7b ... Flange, 7c ... Forward gradient tread, 7d ... Reverse Gradient tread, 8 ... shaft box, 9 ... coil spring, 10 ... connecting portion, 11 ... damper, 12 ... lever, 13 ... link.
θ ... Contact angle R ... Rail

Claims (7)

  In railcar trolleys equipped with left and right wheel units consisting of axles and wheels, the left and right axles constituting the wheel units are inclined so that the inside is high and the outside is low when viewed from the front, and these axles are rotatable. A railcar bogie characterized in that the left and right wheels to be supported are formed with flanges on the outside as viewed from the front and the upper part is inclined outward.   In railcar trolleys equipped with left and right wheel units consisting of axles and wheels, the left and right axles constituting the wheel units are inclined so that the outside is high and the inside is low when viewed from the front, and these axles are rotatable. A railcar bogie characterized in that the left and right wheels to be supported are formed with flanges on the inside as viewed from the front and the upper part is inclined inward.   The railway vehicle carriage according to claim 1 or 2, wherein the wheel has a cylindrical shape.   The railway vehicle carriage according to claim 1 or 2, wherein the axle is provided for each wheel unit, and each axle is connected by a link so as to be individually rotatable around a vertical axis. A railcar bogie characterized by   The railway vehicle carriage according to claim 1 or 2, wherein the axle is provided for each wheel unit, and the axles are integrated.   A railway vehicle comprising a vehicle body supported on the railway vehicle carriage according to claim 1.   A railway system comprising the railway vehicle according to claim 6 and a rail.

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