Patent Description:
The document <CIT> discloses a bogie having an air spring, the air spring comprising an upper supporting portion, a lower supporting portion, and a diaphragm disposed between the upper supporting portion and the lower supporting portion. The upper supporting portion is provided with an upper stopper member. A movable lower stopper member is provided on the lower supporting portion.

In a railway vehicle, a vehicle body is excited in a roll direction of the vehicle body by a change in a centrifugal force acting on the vehicle body when the railway vehicle travels on a curve at a high speed, roll vibration consequently occurs to the vehicle body, and passengers may feel a sense of discomfort. Moreover, the vehicle body leans toward the outside of the curve due to the centrifugal force acting on the vehicle body, a roll angle displacement of the vehicle body consequently increases, left-right stationary acceleration of the vehicle body felt by the passengers increases, and hence, the passengers may feel the sense of discomfort. The sense of discomfort felt by the passengers leads to deterioration of ride comfort, and therefore, it is preferred that the roll displacement and vibration of the vehicle body be suppressed in the state of a high speed travel on a curve, to increase the ride comfort.

Meanwhile, when the railway vehicle travels on a sharp curve at a low speed, roll vibration occurs to the vehicle body due to excitation caused by track irregularity in a left-right direction and the roll direction, and hence, the passengers may feel the sense of discomfort. Further, a wheel load fluctuates due to a torsional change in the track on a relaxation curve of the sharp curve, and hence, a margin for curve passage safety decreases. Therefore, it is required to reduce the roll vibration of the vehicle body and suppress the wheel load variation in the case of the passage on a sharp curve at a low speed.

In this regard, there is provided a bogie for a railway vehicle according to <CIT> as a bogie for a railway vehicle which reduces the roll vibration of the vehicle body.

In the bogie for a railway vehicle according to <CIT>, a damping force in an up-down direction is generated by an orifice provided inside a damping member formed inside an air spring, thereby suppressing the roll vibration of the vehicle body.

However, the damping force generated by the damping member does not change according to a travel state such as a straight line travel and a curve travel, and the generated damping force in the up-down direction is not necessarily be optimized for the curve travel. Therefore, for example, there is such a problem that, in a case where the damping force generated by the damping member is set so as to suitably suppress the roll vibration at the time of the straight line travel, the roll vibration is not sufficiently suppressed at the time of the curve travel and hence there is a fear that the ride comfort deteriorates.

The present invention has been made in view of these problems and has an object to provide a bogie for a railway vehicle which uses a simple configuration to be able to reduce roll vibration of a vehicle body and vehicle body left-right stationary acceleration at the time of a curve travel, thereby increasing the ride comfort, and to further suppress a wheel load variation at the time of the curve travel, thereby securing safety.

In order to achieve the above-mentioned object, one representative bogie for a railway vehicle according to claim <NUM>.

The present invention can provide a bogie for a railway vehicle which uses the simple configuration to be able to reduce the roll vibration of the vehicle body and the left-right stationary acceleration of the vehicle body at the time of a high-speed curve travel, thereby increasing the ride comfort. In this case, since the left-right stationary acceleration of the vehicle body can be suppressed low, a travel at a higher speed on a curve can be achieved without spoiling the ride comfort. Further, since the roll vibration of the vehicle body can be reduced at the time of a low-speed curve travel, it is possible to increase the ride comfort while suppressing the wheel load variation, so that a highly safe bogie for a railway vehicle can be provided.

Problems, configurations, and effects other than those described above will become apparent from the following description of embodiments.

A description is now given of a first embodiment of the present invention with reference to <FIG>, <FIG>, and <FIG>. <FIG> is a view for showing a bogie <NUM> for a railway vehicle according to the first embodiment of the present invention. <FIG> and <FIG> are views for showing a detailed configuration example of an air spring <NUM> of the bogie <NUM> for a railway vehicle according to the first embodiment of the present invention.

The air spring <NUM> according to the present embodiment is arranged in the bogie <NUM> for a railway vehicle shown in <FIG>, and the bogie <NUM> for a railway vehicle mainly includes a bogie frame <NUM>, an axle box <NUM>, a wheelset <NUM>, an axle box support device <NUM>, and the air spring <NUM>. The wheelset <NUM> is supported by the axle box <NUM> via bearings (not shown) in a rotatable state, and the axle box <NUM> and the bogie frame <NUM> are coupled to each other by the axle box support device <NUM>. The air spring <NUM> is interposed between the bogie frame <NUM> and a vehicle body <NUM>, and the vehicle body <NUM> is elastically supported by the air spring <NUM> from below.

A detailed configuration of the air spring <NUM> is shown in <FIG> and <FIG>. <FIG> is a front cross-sectional view of the air spring <NUM>, and <FIG> is a side cross-sectional view of the air spring <NUM>. In <FIG>, an arrow "y" indicates a left-right direction, and in <FIG>, an arrow "x" indicates a front-back direction. Note that, in <FIG>, the air spring <NUM> is shown on a cross section taken along line A-A of <FIG> to be described later. In <FIG>, portions which are of the air spring <NUM> and are other than a stopper rubber <NUM> and a stopper rubber receiver <NUM> to be described later are shown on a cross section taken along line B-B of <FIG>, and the stopper rubber <NUM> and the stopper rubber receiver <NUM> are shown on a cross section taken along line C-C of <FIG>.

The air spring <NUM> mainly includes an upper surface plate <NUM>, a bellows <NUM>, a lower surface plate <NUM>, laminated rubber <NUM>, and an air spring seat <NUM>. The upper surface plate <NUM> and the lower surface plate <NUM> are coupled to each other via the bellows <NUM>. The upper surface plate <NUM> is coupled to the vehicle body <NUM>, and the lower surface plate <NUM> is coupled to the bogie frame <NUM> via the laminated rubber <NUM> and the air spring seat <NUM>.

An air chamber <NUM> filled with air is defined in the bellows <NUM>, compressibility of the air provides elastic support between the vehicle body <NUM> and the bogie frame <NUM> in an up-down direction, and an elastic action of rubber provides elastic support between the vehicle body <NUM> and the bogie frame <NUM> in a horizontal direction. That is, the air spring <NUM> allows displacements in the up-down direction and the horizontal direction (the front-back direction and the left-right direction) of the vehicle body <NUM> with respect to the bogie frame <NUM>. A communication opening <NUM> is provided inside the air spring seat <NUM>, and the air chamber <NUM> and an auxiliary air chamber (auxiliary tank), not shown, are caused to communicate with each other via the communication opening <NUM>. An orifice <NUM> is provided in an upper portion of the communication opening <NUM>, and a damping force is generated in the up-down direction of the air spring <NUM> by a resistance effect exhibited at the time of passage of air between the air chamber <NUM> and the auxiliary air chamber. The laminated rubber <NUM> provides elastic support between the vehicle body <NUM> and the bogie frame <NUM> in the up-down direction and the horizontal direction in a state in which the bellows <NUM> is deflated by a puncture or the like. In the present embodiment, there is provided such a configuration that the auxiliary tank is formed on the bogie frame <NUM> side, but there may be provided such a configuration that the auxiliary tank is mounted on the vehicle body <NUM> side and the air chamber <NUM> and the auxiliary tank are caused to communicate with each other via a communication opening and an orifice.

The upper surface plate <NUM> has a lower surface 11A in a circular flat surface shape exposed in the air chamber <NUM>. The lower surface plate <NUM> has an upper surface 13A which is in a circular flat surface shape, is exposed in the air chamber <NUM>, and faces the lower surface 11A of the upper surface plate <NUM> from below. The lower surface 11A of the upper surface plate <NUM> and the upper surface 13A of the lower surface plate <NUM> constitute opposed surfaces which are apart from each other in the up-down direction inside the air chamber <NUM> and which face each other. A position of the lower surface 11A of the upper surface plate <NUM> with respect to the upper surface 13A of the lower surface plate <NUM> (a relative position between the upper and lower opposed surfaces) varies from an initial state in the front-back direction and the left-right direction in response to a displacement of the vehicle body <NUM> in the front-back direction and the left-right direction allowed by the air spring <NUM>. The initial state here means a state in which no load in the horizontal direction is acting from the vehicle body <NUM> to the air spring <NUM>.

A pair of left and right stopper rubbers <NUM> are arranged on and fixed to the upper surface 13A of the lower surface plate <NUM>. A pair of left and right stopper rubber receivers <NUM> are arranged on and fixed to the lower surface 11A of the upper surfaceplate <NUM>. A side cross-sectional view of one of the stopper rubbers <NUM> and one of the stopper rubber receivers <NUM> is shown in <FIG>. The stopper rubber <NUM> protrudes upward from the upper surface 13A of the lower surface plate <NUM> toward the lower surface 11A of the upper surface plate <NUM>. The stopper rubber receiver <NUM> faces downward from the lower surface 11A of the upper surface plate <NUM>. The stopper rubber <NUM> faces a central portion <NUM> of the stopper rubber receiver <NUM> in the initial state. The stopper rubber receiver <NUM> is in a plate form body having a cross shape extending from the central portion <NUM> in the front-back direction and the left-right direction in a plan view. One of the stopper rubber <NUM> and the stopper rubber receiver <NUM> is formed of a soft elastic body such as rubber, and the other is formed of a hard member (hard non-elastic body). While, in the present embodiment, the stopper rubber <NUM> is formed of a soft elastic body such as rubber and the stopper rubber receiver <NUM> is formed of a hard member, conversely, a component corresponding to the stopper rubber <NUM> may be formed of a hard member and a component corresponding to the stopper rubber receiver <NUM> may be formed of an elastic body such as rubber, which can provide an equivalent effect.

<FIG> is a plan view for showing an arrangement of the pair of stopper rubbers <NUM> on the lower surface plate <NUM> and an arrangement of the pair of stopper rubber receivers <NUM> on the upper surface plate <NUM>. The stopper rubber receivers <NUM> are indicated by broken lines in <FIG>. In the present embodiment, the left and right pair of stopper rubbers <NUM> are arranged with respect to a center of the upper surface 13A of the lower surface plate <NUM>, and the left and right pair of stopper rubber receivers <NUM> are arranged with respect to a center of the lower surface 11A (see <FIG>) of the upper surface plate <NUM>. Note that, as for the stopper rubbers <NUM> and the stopper rubber receivers <NUM>, the stopper rubber receivers <NUM> may be arranged on the upper surface 13A of the lower surface plate <NUM>, and the stopper rubbers <NUM> may be arranged on the lower surface 11A of the upper surface plate <NUM>.

As shown in <FIG>, each stopper rubber receiver <NUM> has such a shape in the left-right direction that a gap between the stopper rubber receiver <NUM> and the upper surface 13A of the lower surface plate <NUM> is wide at the central portion <NUM> in a flat surface shape and the gap between the stopper rubber receiver <NUM> and the upper surface 13A of the lower surface plate <NUM> is narrow at end portions (left end portion <NUM> and right end portion 22R). That is, at the left and right end portions <NUM> and 22R of the stopper rubber receiver <NUM> facing each other across the central portion <NUM>, a plate thickness (thickness in the up-down direction) of the stopper rubber receiver <NUM> is larger than that at the central portion <NUM>, and a separation distance in the up-down direction from the stopper rubber receiver <NUM> to the upper surface 13A of the lower surface plate <NUM> is shorter than that at the central portion <NUM>.

Moreover, as shown in <FIG>, the stopper rubber receiver <NUM> has such a shape in the front-back direction that the gap between the stopper rubber receiver <NUM> and the upper surface 13A of the lower surface plate <NUM> is narrow at the central portion <NUM> and the gap between the stopper rubber receiver <NUM> and the upper surface 13A of the lower surface plate <NUM> is wide at end portions (front end portion 22F and back end portion 22B). That is, at the front and back end portions 22F and 22B of the stopper rubber receiver <NUM> facing each other across the central portion <NUM>, the plate thickness of the stopper rubber receiver <NUM> is thinner than that at the central portion <NUM>, and the separation distance in the up-down direction from the stopper rubber receiver <NUM> to the upper surface 13A of the lower surface plate <NUM> is longer than that at the central portion <NUM>.

A lower surface of the central portion <NUM> and lower surfaces of the left and right end portions <NUM> and 22R of the stopper rubber receiver <NUM> are continuous to each other via left and right inclined surfaces, and the plate thickness of the stopper rubber receiver <NUM> gradually increases from the central portion <NUM> toward the left and right end portions <NUM> and 22R. The lower surface of the central portion <NUM> and lower surfaces of the front and back end portions 22F and 22B of the stopper rubber receiver <NUM> are continuous to each other via front and back inclined surfaces, and the plate thickness of the stopper rubber receiver <NUM> gradually decreases from the central portion <NUM> toward the front and back end portions 22F and 22B. The stopper rubber <NUM> is in a column shape (for example, a circular column shape) standing up in the up-down direction, and a distal end portion (upper end portion in the present embodiment) 21T of the stopper rubber <NUM> is in a tapered or semispherical shape tapering upward toward the upper surface plate <NUM>.

With reference to <FIG> and <FIG>, a description is now given of an operation at the time when the bogie <NUM> for a railway vehicle travels on a curve at a high speed. In <FIG>, there is shown a relation between a left-right relative displacement "y" between the stopper rubber <NUM> and the stopper rubber receiver <NUM> and an up-down force Fz which is generated in the stopper rubber <NUM>.

When a large centrifugal force acts on the vehicle body <NUM> at the time of a high speed travel on a curve, the vehicle body <NUM> displaces in the left-rightdirection (left or right outside) from the initial state with respect to the bogie frame <NUM>. The upper surface plate <NUM> and the stopper rubber receiver <NUM>, along with the vehicle body <NUM>, also relatively displace from the initial state toward the left or right outside of the curve, and as a result, there is brought about such a state that the stopper rubber <NUM> and the stopper rubber receiver <NUM> come in contact with each other in the region (the left end portion <NUM> or the right end portion 22R of the stopper rubber receiver <NUM>) in which the gap between the stopper rubber receiver <NUM> and the lower surface plate <NUM> is narrow. In this state, the stopper rubber <NUM> is brought into a state in which the stopper rubber <NUM> is compressed in the up-down direction. In <FIG>, the left-right relative displacement "y" between the stopper rubber <NUM> and the stopper rubber receiver <NUM> is at y0 before the bogie <NUM> for a railway vehicle enters the curve, and displaces to y1 at the time of the curve travel. At the left-right relative displacement y1, the stopper rubber <NUM> in the state of being compressed in the up-down direction is switched to a state in which a gradient of the up-down force Fz is large, that is, a state in which up-down rigidity kz is high. As described above, the up-down rigidity kz of the stopper rubber <NUM> increases, and the air spring <NUM> provides the support between the vehicle body <NUM> and the bogie frame <NUM> in the state in which total up-down rigidity is high, and as a result, comes to support the vehicle body <NUM> in a state in which roll rigidity between the vehicle body <NUM> and the bogie frame <NUM> is high.

With reference to <FIG> and <FIG>, a description is now given of an operation at the time when the bogie <NUM> for a railway vehicle travels on a sharp curve at a low speed. In <FIG>, there is shown a relation between a front-back relative displacement "x" between the stopper rubber <NUM> and the stopper rubber receiver <NUM> and the up-down force Fz which is generated in the stopper rubber <NUM>.

When the bogie <NUM> for a railway vehicle traveling on a sharp curve at a low speed enters the curve, a yaw angle between the vehicle body <NUM> and the bogie frame <NUM> increases, and in the air spring <NUM> portion, the vehicle body <NUM> displaces from the initial state in the front-back direction with respect to the bogie frame <NUM>. The upper surface plate <NUM> and the stopper rubber receiver <NUM>, along with the vehicle body <NUM>, also relatively displace from the initial state in the front-back direction, and as a result, there is brought about such a state that the stopper rubber <NUM> and the stopper rubber receiver <NUM> come in contact with each other in a region (the front end portion 22F or the back end portion 22B of the stopper rubber receiver <NUM>) in which the gap between the stopper rubber receiver <NUM> and the lower surface plate <NUM> is wide. In this state, the stopper rubber <NUM> is brought into a state in which the stopper rubber <NUM> is not compressed in the up-down direction. In <FIG>, the front-back relative displacement "x" between the stopper rubber <NUM> and the stopper rubber receiver <NUM> is at x0 before the bogie <NUM> for a railway vehicle enters the curve, and displaces to x1 at the time of the curve travel. At the front-back relative displacement x1, the stopper rubber <NUM> in the state of not being compressed in the up-down direction is switched to a state in which the gradient of the up-down force Fz is small, that is, a state in which the up-down rigidity kz is low. As described above, the up-down rigidity kz of the stopper rubber <NUM> decreases, and the air spring <NUM> provides the support between the vehicle body <NUM> and the bogie frame <NUM> in the state in which the total up-down rigidity is low, and as a result, comes to support the vehicle body <NUM> in a state in which the roll rigidity between the vehicle body <NUM> and the bogie frame <NUM> is low.

As described above, in the bogie <NUM> for a railway vehicle according to the present embodiment, the vehicle body <NUM> can be supported in the state in which the vehicle body roll rigidity is high at the time of a high-speed curve travel, and hence, vehicle body roll vibration and wobbling caused by a change in an excess centrifugal force acting at the time of the curve travel can be reduced, so that the ride comfort relating to the roll can be increased. Moreover, the outward-falling roll displacement of the vehicle body caused by the excess centrifugal force acting at the time of the curve travel can be reduced, and hence, vehicle body left-right stationary acceleration sensed by passengers can be reduced, so that the ride comfort at the time of the high-speed curve travel can be increased. In this case, since the left-right stationary acceleration of the vehicle body can be suppressed low, a travel at a higher speed on a curve can be achieved without spoiling the ride comfort.

Further, in the bogie <NUM> for a railway vehicle according to the present embodiment, since the vehicle body <NUM> can be supported in the state in which the vehicle body roll rigidity is low at the time of a low-speed sharp curve travel, vibration transmissibility in the roll direction between the vehicle body <NUM> and the bogie frame <NUM> at the time of the curve travel is reduced, so that a vehicle body roll vibration response to excitation input in the left-right and roll directions due to track irregularity can be reduced, thereby enabling an increase in the ride comfort relating to the roll. Moreover, since roll support rigidity between the vehicle body <NUM> and the bogie frame <NUM> is low, the bogie <NUM> for a railway vehicle easily follows a change in truck on a relaxation curve at the time of the curve travel, so that a wheel load variation at the time of the curve travel can be suppressed, thereby enabling provision of the highly safe bogie <NUM> for a railway vehicle.

Moreover, the bogie <NUM> for a railway vehicle according to the present embodiment has such a simple configuration that the combinations of the stopper rubbers <NUM> and the stopper rubber receivers <NUM> are provided to the air spring <NUM>, and hence, the highly reliable bogie <NUM> for a railway vehicle can be provided at a low cost.

Moreover, the- lower surface of the central portion <NUM> and the lower surfaces of the left and right end portions <NUM> and 22R of the stopper rubber receiver <NUM> are continuous to each other via the left and right inclined surfaces, the lower surface of the central portion <NUM> and the lower surfaces of the front and back end portions 22F and 22B are continuous to each other via the front and back inclined surfaces, and the distal end portion 21T of the stopper rubber <NUM> is in a tapered or semispherical shape tapering upward toward the lower surface 11A of the upper surface plate <NUM>. Therefore, when the stopper rubber <NUM> and the stopper rubber receiver <NUM> displace relative to each other from the initial state, the distal end portion 21T of the stopper rubber <NUM> can smoothly be moved relatively in the front-back direction and the left-right direction from the position facing the central portion <NUM> of the stopper rubber receiver <NUM>.

Note that, in the present embodiment, the one pair of stopper rubbers <NUM> and the one pair of stopper rubber receivers <NUM> are arranged in the left-right direction with respect to the centers of the upper surface plate <NUM> and the lower surface plate <NUM>, but the one pair of stopper rubbers <NUM> and the one pair of stopper rubber receivers <NUM> may be arranged in the front-back direction with respect to the centers of the upper surface plate <NUM> and the lower surface plate <NUM>, which can provide an effect equivalent to that of the present embodiment.

A description is now given of a second embodiment of the present invention with reference to <FIG>, <FIG>, and <FIG>. In <FIG>, <FIG>, and <FIG>, members having functions same as those in the first embodiment are denoted by reference symbols same as those in <FIG> and <FIG>. <FIG> and <FIG> show a form example of an air spring <NUM> configured such that a stopper rubber <NUM> and a stopper rubber receiver <NUM> are arranged at a center of a lower surface plate <NUM> and a center of an upper surface plate <NUM>. Note that, in <FIG>, the air spring <NUM> is shown on a cross section taken along line D-D of <FIG>, and in <FIG>, the air spring <NUM> is shown on a cross section taken along line E-E of <FIG>.

A detailed configuration of the air spring <NUM> is shown in <FIG> and <FIG>. <FIG> is a front cross-sectional view of the air spring <NUM>, and <FIG> is a side cross-sectional view of the air spring <NUM>. In <FIG>, an arrow "y" indicates the left-right direction, and in <FIG>, an arrow "x" indicates the front-back direction.

The air spring <NUM> mainly includes the upper surface plate <NUM>, the bellows <NUM>, the lower surface plate <NUM>, the laminated rubber <NUM>, and an air spring seat <NUM>. The upper surface plate <NUM> and the lower surface plate <NUM> are coupled to each other via the bellows <NUM>, and the air spring <NUM> provides, as with the air spring <NUM> in the first embodiment, elastic support between the vehicle body <NUM> and the bogie frame <NUM> in the up-down direction and the horizontal direction. A communication opening <NUM> is provided inside the upper surface plate <NUM>, and the air chamber <NUM> and an auxiliary tank, which is mounted to the vehicle body <NUM> and is not shown, are caused to communicate with each other via the communication opening <NUM>. An orifice <NUM> is formed in the communication opening <NUM>, and a damping force is generated in the up-down direction of the air spring <NUM> by a resistance effect exhibited at the time of passage of air between the air chamber <NUM> and the auxiliary tank. While, in the present embodiment, there is provided such a configuration that the auxiliary tank is mounted on the vehicle body <NUM> side, there may otherwise be provided such a configuration that the auxiliary tank is provided on the bogie frame <NUM> side and the air chamber <NUM> and the auxiliary tank are caused to communicate with each other via a communication opening and an orifice.

The upper surface plate <NUM> has a lower surface 31A in a circular flat surface shape exposed in the air chamber <NUM>. The lower surface plate <NUM> has an upper surface 33A which is in a circular flat surface shape, is exposed in the air chamber <NUM>, and faces the lower surface 31A of the upper surface plate <NUM> from below. The lower surface 31A of the upper surface plate <NUM> and the upper surface 33A of the lower surface plate <NUM> constitute opposed surfaces which are apart from each other in the up-down direction in the air chamber <NUM> and which face each other. A position of the lower surface 31A of the upper surface plate <NUM> with respect to the upper surface 33A of the lower surface plate <NUM> (a relative position between the upper and lower opposed surfaces) varies from the initial state in the front-back direction and the left-right direction in response to a displacement of the vehicle body <NUM> in the front-back direction and the left-right direction allowed by the air spring <NUM>.

The stopper rubber <NUM> and the stopper rubber receiver <NUM> are arranged on and fixed to the center of the upper surface 33A of the lower surface plate <NUM> and the center of the lower surface 31A of the upper surface plate <NUM>, respectively. In <FIG>, front cross-sectional views of the stopper rubber <NUM> and the stopper rubber receiver <NUM> are shown, and in <FIG>, side cross-sectional views of the stopper rubber <NUM> and the stopper rubber receiver <NUM> are shown. <FIG> is a plan view for showing an arrangement of the stopper rubber <NUM> on the lower surface plate <NUM> and an arrangement of the stopper rubber receiver <NUM> on the upper surface plate <NUM>. The stopper rubber receiver <NUM> is indicated by broken lines in <FIG>. The stopper rubber <NUM> and the stopper rubber receiver <NUM> have shapes same as those of the stopper rubber <NUM> and the stopper rubber receiver <NUM> in the first embodiment.

That is, as shown in <FIG>, the stopper rubber receiver <NUM> has such a shape in the left-right direction that a gap between the stopper rubber receiver <NUM> and the upper surface 33A of the lower surface plate <NUM> is wide at a central portion <NUM> in a flat surface shape and the gap between the stopper rubber receiver <NUM> and the upper surface 33A of the lower surface plate <NUM> is narrow at end portions (left end portion <NUM> and right end portion 42R). Moreover, as shown in <FIG>, the stopper rubber receiver <NUM> has such a shape in the front-back direction that the gap between the stopper rubber receiver <NUM> and the upper surface 33A of the lower surface plate <NUM> is narrow at the central portion <NUM> and the gap between the stopper rubber receiver <NUM> and the upper surface 33A of the lower surface plate <NUM> is wide at end portions (front end portion 42F and back end portion 42B).

An operation of the bogie <NUM> for a railway vehicle according to the present embodiment at the time of traveling at a high speed on a curve is the same as that in the first embodiment. That is, when a centrifugal force in the left-right direction acts on the vehicle body <NUM> on the curve, a left-right relative displacement between the stopper rubber <NUM> and the stopper rubber receiver <NUM> occurs, and there is brought about such a state that the stopper rubber <NUM> and the stopper rubber receiver <NUM> come in contact with each other in the region (the left end portion <NUM> or the right end portion 42R of the stopper rubber receiver <NUM>) in which the gap between the stopper rubber receiver <NUM> and the lower surface plate <NUM> is narrow. In this state, the stopper rubber <NUM> is brought into a state of being compressed in the up-down direction, and up-down rigidity of the stopper rubber <NUM> becomes high. Therefore, the vehicle body <NUM> is supported in the state in which the roll rigidity between the vehicle body <NUM> and the bogie frame <NUM> is high.

When the bogie <NUM> for a railway vehicle traveling on a sharp curve at a low speed enters the curve, the yaw angle between the vehicle body <NUM> and the bogie frame <NUM> increases, and a front-back relative displacement between the stopper rubber <NUM> and the stopper rubber receiver <NUM> occurs. There is thus brought about such a state that the stopper rubber <NUM> and the stopper rubber receiver <NUM> come in contact with each other in the region (the front end portion 42F or the back end portion 42B of the stopper rubber receiver <NUM>) in which the gap between the stopper rubber receiver <NUM> and the lower surface plate <NUM> is wide. In this state, the stopper rubber <NUM> is brought into a state of not being compressed in the up-down direction, and the up-down rigidity of the stopper rubber <NUM> becomes low. Therefore, the vehicle body <NUM> is supported in the state in which the roll rigidity between the vehicle body <NUM> and the bogie frame <NUM> is low.

In the bogie <NUM> for a railway vehicle according to the present embodiment described above, the vehicle body <NUM> can be supported in the state in which the vehicle body roll rigidity is high at the time of a high-speed curve travel, and hence, the ride comfort relating to the roll at the time of the curve travel can be increased, and moreover, left-right ride comfort at the time of the curve travel can be increased.

Further, in the bogie <NUM> for a railway vehicle according to the present embodiment, the vehicle body <NUM> can be supported in the state in which the vehicle body roll rigidity is low at the time of a low-speed sharp curve travel, and hence, the ride comfort relating to the roll can be increased by reducing the vehicle body roll vibration response to excitation input due to track irregularity at the time of the curve travel, and moreover, a wheel load variation on a relaxation curve at the time of the curve travel can be suppressed.

As described above, in the present embodiment, it is possible to achieve the reduction in the vehicle body roll vibration/vehicle body left-right stationary acceleration and the suppression of the wheel load variation, as with the first embodiment, through use of such a configuration that the one set of the stopper rubber <NUM> and the stopper rubber receiver <NUM> is provided to the air spring <NUM>, which is simple and involves the small number of components.

Claim 1:
A bogie (<NUM>) for a railway vehicle, comprising:
an air spring (<NUM>, <NUM>) that elastically supports a vehicle body (<NUM>) from below,
wherein the air spring includes upper and lower opposed surfaces (11A, 13A, 31A, 33A) that are apart from each other in an up-down direction and face each other, and a stopper rubber (<NUM>, <NUM>) and a stopper rubber receiver (<NUM>, <NUM>) that are arranged between the upper and lower opposed surfaces,
a relative position between the upper and lower opposed surfaces varies from an initial state in the up-down direction, left-right direction, and front-back direction in response to a displacement of the vehicle body with respect to the bogie frame in the up-down direction and a horizontal direction allowed by the air spring,
the stopper rubber is fixed to one opposed surface of the upper and lower opposed surfaces and protrudes toward the other opposed surface,
the stopper rubber receiver is fixed to the other opposed surface and is apart from the one opposed surface,
the stopper rubber faces a central portion (<NUM>, <NUM>) of the stopper rubber receiver in the initial state,
characterised in that,
separation distances to the one opposed surface in the up-down direction at left and right end portions (<NUM>, 22R, <NUM>, 42R) of the stopper rubber receiver facing each other across the central portion are shorter than that at the central portion, and
separation distances to the one opposed surface in the up-down direction at front and back end portions (22F, 22B, 42F, 42B) of the stopper rubber receiver facing each other across the central portion are longer than that at the central portion.