JP2017105239A - Underframe structure of railroad carriage - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce strength poverty of a weld part of both sides of vehicle longer direction of a cap beam in an underframe structure that the cap beam is joined by welding from downside to a part of a floorboard of a double skin construction.SOLUTION: An underframe structure of a railroad carriage comprises a floorboard and a cap beam. Edges of both sides of a vehicle longer direction of the cap beam upper skin is welded to an undersurface of a floor lower skin. Multiple cap beam ribs include multiple first cap beam ribs. The first cap beam rib is arranged at a position that the virtual extension line overlaps with a virtual extension line of the floor rib in an area including the floor lower skin and the cap beam upper skin seeing from the vehicle longer direction.SELECTED DRAWING: Figure 4

Description

  The present invention relates to a frame structure for a railway vehicle.

  The railcar frame structure includes a pair of side beams extending in the longitudinal direction of the vehicle and pillow beams extending in the vehicle width direction and connected to the pair of side beams, and the cart is connected to the pillow beams. The pillow beam of Patent Document 1 is formed by extrusion molding, and the top surface of the pillow beam forms the bottom surface inside the vehicle. When a vehicle longitudinal load is transmitted from the carriage to the lower part of the pillow beam due to acceleration / deceleration of the vehicle, or when a downward load is applied to a part of the pillow beam that is not supported by the carriage and bending stress occurs in the pillow beam The strength of the vehicle body is maintained, for example, by slightly bending the pillow beam while resisting the load due to the rigidity of the pillow beam.

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  By the way, a railway vehicle having a double skin structure as a whole body is known. If a pillow beam is to be joined to a part of a floor plate with a double skin structure from below, it is conceivable that the edges on both sides in the vehicle longitudinal direction of the upper part of the pillow beam are line welded to the lower surface of the floor plate in the vehicle width direction. . However, if the pillow beam is slightly bent due to a load applied to the pillow beam, local stress is generated in the welded portion, resulting in insufficient strength in the welded portion.

  SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to reduce the lack of strength of the welded portions on both sides in the longitudinal direction of a pillow beam in a frame structure in which a pillow beam is welded to a part of a floor plate having a double skin structure from below.

  A railcar frame structure according to an aspect of the present invention includes a floor upskin, a floor lower skin disposed below the floor upskin, and a plurality of floor ribs connected to the floor upskin and the floor lower skin. A floor plate in which the floor rib extends in the longitudinal direction of the vehicle, a pillow beam upper skin, a pillow beam lower skin disposed below the pillow beam upper skin, and a plurality of pillow beams connected to the pillow beam upper skin and the lower beam skin A pillow beam rib, and the pillow beam rib extends in the longitudinal direction of the vehicle, and both edges of the pillow beam appaskin in the longitudinal direction of the vehicle are welded to the lower surface of the floor lower skin. The plurality of pillow beam ribs include a plurality of first pillow beam ribs, and the first pillow beam ribs, when viewed from the vehicle longitudinal direction, have virtual extension lines that include the floor lower skin and the pillow beam upskin. Is disposed at a position overlapping the imaginary extension of the floor ribs in Align was region.

  According to the above configuration, when the load generated on the pillow beam or the floorboard is transmitted between the first pillow beam rib and the floor rib, the load transmission path is prevented from being offset in the vehicle width direction. The Therefore, the load is suppressed from being transmitted in the vehicle width direction in the floor lower skin and the pillow beam upskin, and insufficient strength of the welded portion due to the stress generated in the floor lower skin and the pillow beam upskin can be suppressed.

  ADVANTAGE OF THE INVENTION According to this invention, in the frame structure which joined the pillow beam by welding to a part of floor board of a double skin structure from the downward direction, the strength shortage of the welding part of the vehicle longitudinal direction both sides of a pillow beam can be reduced.

It is a bottom view of the frame structure of the railway vehicle which concerns on embodiment. It is sectional drawing seen from the vehicle longitudinal direction of the frame structure shown in FIG. It is the perspective view which looked at the principal part of the frame structure shown in FIG. 2 from diagonally downward. FIG. 3 is a cross-sectional view of one side in the vehicle width direction of the frame structure shown in FIG. FIG. 5 is an enlarged view of the frame structure shown in FIG. 4.

  Hereinafter, embodiments will be described with reference to the drawings.

  FIG. 1 is a bottom view of the frame structure 6 of the railcar 1 according to the embodiment. FIG. 2 is a cross-sectional view of the frame structure 6 shown in FIG. 1 as seen from the vehicle longitudinal direction. FIG. 3 is a perspective view of the main part of the frame structure 6 shown in FIG. 2 as viewed obliquely from below. As shown in FIGS. 1 and 2, the railway vehicle 1 includes a vehicle body 2 having a cabin on which passengers board, and a carriage 3 that supports the vehicle body 2 from below. The carriage 3 is a known one and includes a carriage frame 4 and a wheel shaft 5. The vehicle body 2 includes a frame structure 6 serving as a vehicle body bottom portion. The underframe structure 6 is formed symmetrically in the vehicle width direction. The underframe structure 6 includes a floor plate 7, side beams 8, end beams 9, pillow beams 10, cross beams 11, first middle beams 12, and second middle beams 13. The floor plate 7, the side beams 8 and the pillow beams 10 have a double skin structure, and the end beams 9, the lateral beams 11, the first middle beam 12 and the second middle beam 13 have a single skin structure.

  The floor board 7 extends from one end of the vehicle body 2 to the other end in the longitudinal direction of the vehicle. The side beams 8 are joined to the ends of the floor board 7 in the vehicle width direction, extend in the vehicle longitudinal direction, and project downward from the floor board 7. The end beam 9 extends in the vehicle width direction at the end of the vehicle body 2 in the vehicle longitudinal direction. The pillow beam 10 extends in the vehicle width direction inside the end beam 9 in the vehicle longitudinal direction, and is joined to the lower surface of the floor plate 7 and the side beam 8. The lateral beam 11 extends in the vehicle width direction inward of the longitudinal direction of the vehicle from the pillow beam 10, and is joined to the lower surface of the floor plate 7 and the side beam 8. The horizontal beam 11 is smaller in dimension in the vehicle longitudinal direction than the pillow beam 10. The first middle beam 12 extends in the longitudinal direction of the vehicle and is joined to the end beam 9 and the pillow beam 10. The second middle beam 13 extends in the longitudinal direction of the vehicle and is joined to the pillow beam 10 and the cross beam 11.

  The carriage 3 is connected to the pillow beam 10. The pillow beam 10 has a central portion 10a located in the center in the vehicle width direction, end portions 10b located on both sides in the vehicle width direction, and an intermediate portion 10c located between the central portion 10a and the end portions 10b. A center pin 14 is fixed to the central portion 10 a of the pillow beam 10, and the center pin 14 is connected to the carriage frame 4. The end 10b of the pillow beam 10 is supported from below by the carriage frame 4 via air springs 16 disposed on both sides of the center pin 14 in the vehicle width direction. The lower surface of the intermediate part 10c is a free surface opened downward.

  As shown in FIG. 3, the edges of both sides of the pillow beam 10 in the vehicle longitudinal direction are line-welded to the lower surface of the floor board 7 in the vehicle width direction (welded portion W). Specifically, the edges of both sides in the longitudinal direction of the pillow beam upskin 31 described later are line-welded to the lower surface of the floor lower skin 22 in the vehicle width direction. The edges of both sides of the pillow beam 10 in the vehicle width direction are overlapped with the spacer 17 welded to the lower surface of the side beam 8 from below and are line welded to the spacer 17 in the longitudinal direction of the vehicle. In addition, you may weld the edge part of the vehicle width direction both sides of the pillow beam 10 directly to the side beam 8 without using the spacer 17. FIG. Moreover, it is good also as a several spot welding instead of line welding.

  4 is a cross-sectional view of one side in the vehicle width direction of the frame structure 6 shown in FIG. 2 as viewed from the vehicle longitudinal direction. FIG. 5 is an enlarged view of the frame structure 6 shown in FIG. As shown in FIG. 4, the floor board 7 and the pillow beam 10 are formed by extruding a light metal (for example, an aluminum alloy). The floor plate 7 includes a floor upper skin 21, a floor lower skin 22 disposed below the floor upper skin 21, and a plurality of floor ribs 23 connected to the floor upper skin 21 and the floor lower skin 22. The floor rib 23 extends in the vehicle longitudinal direction. That is, the internal space surrounded by the floor upskin 21, the floor lower skin 22, and the floor rib 23 is open toward both sides in the vehicle longitudinal direction.

  The plurality of floor ribs 23 include a plurality of first floor ribs 23A and a plurality of second floor ribs 23B. The first floor rib 23A extends in a direction inclined with respect to the vertical direction, and the second floor rib 23B extends in the vertical direction. The floor board 7 is formed by joining a plurality of extruded shape members 7A to 7D in the vehicle width direction. Each of the extruded shape members 7A to 7D is provided with a pair of second floor ribs 23B at both ends in the vehicle width direction, and the first floor rib 23A is provided in a truss shape between the pair of second floor ribs 23B. Yes. Therefore, the two second floor ribs 23B are arranged close to each other and arranged in parallel at the joint portion between the adjacent extruded shape members 7A to 7D.

  The pillow beam 10 includes a pillow beam upper skin 31, a pillow beam lower skin 32 disposed below the pillow beam upper skin 31, and a plurality of pillow beam ribs 33 connected to the pillow beam upper skin 31 and the pillow beam lower skin 32. The pillow beam rib 33 extends in the longitudinal direction of the vehicle. That is, the internal space surrounded by the pillow beam upper skin 31, the pillow beam lower skin 32, and the pillow beam ribs 33 is also open toward both sides in the vehicle longitudinal direction.

  The vertical dimension of the pillow beam 10 is larger than the vertical dimension of the floor board 7. The thickness of each of the pillow beam upper skin 31 and the pillow beam lower skin 32 is greater than the thickness of each of the floor upper skin 21 and the floor lower skin 22. The thickness of each of the pillow beam ribs 33 is larger than any thickness of the floor ribs 23. The pillow beam upskin 31 is flat from one end to the other end in the vehicle width direction. The pillow beam lower skin 32 is flat at each position corresponding to the central portion 10a and the end portion 10b.

  The vertical dimension of the central portion 10 a of the pillow beam 10 is larger than the vertical dimension of the end portion 10 b of the pillow beam 10. The pillow beam lower skin 32 has an inclined portion 32 a that extends obliquely downward and inward in the vehicle width direction in the intermediate portion 10 c of the pillow beam 10. The pillow beam lower skin 32 includes a central flat portion 32b that continues to the inside of the inclined portion 32a in the vehicle width direction, and an end flat portion 32c that continues to the outside of the inclined portion 32a in the vehicle width direction.

  4 and 5, the plurality of pillow beam ribs 33 include a plurality of first pillow beam ribs 33A to 33F and a plurality of second pillow beam ribs 33H to 33J. As representatively illustrated by the first pillow beam ribs 33B and 33C in FIG. 5, the first pillow beam ribs 33A to 33F have virtual extension lines BL1 and BL2 as the floor lower skin 22 as viewed from the longitudinal direction of the vehicle. Are provided at positions overlapping the virtual extension lines FL1 and FL2 of the floor ribs 23A and 23B, respectively, in the region X where the pillow beam and the upskin 31 are combined. For example, the virtual extension line BL1 of the first pillow beam rib 33B overlaps with the virtual extension line FL1 of the two second floor ribs 23B in the region X. In the region X, the virtual extension line BL2 of the first pillow rib 33C intersects the virtual extension line FL2 of one first floor rib 23A and overlaps with the virtual extension line FL2 of another first floor rib 23A. Overlapping along.

  As representatively shown in FIG. 5 by the second pillow beam ribs 33H, the second pillow beam ribs 33H to 33J have a virtual extension line BL3 as viewed from the longitudinal direction of the vehicle. In the region X combined with 31, the floor ribs 23 </ b> A and 23 </ b> B are disposed at positions separated from the virtual extension lines FL <b> 1 and FL <b> 2. That is, the second pillow beam ribs 33H to 33J do not overlap in the region X with the virtual extension line of any of the floor ribs 23A and 23B.

  In the present embodiment, the virtual extension line of the pillow beam rib is a virtual line obtained by extending the outline of the pillow beam rib toward the floor plate in the rib extending direction when viewed from the vehicle longitudinal direction, and is the same as the pillow beam rib. A virtual line with a thickness. Similarly, the virtual extension line of the floor rib is a virtual line that extends from the longitudinal direction of the floor rib toward the pillow beam side in the rib extension direction when viewed from the longitudinal direction of the vehicle and has the same thickness as the floor rib. is there.

  At least the first pillow beam ribs 33A to 33F are disposed at the central portion 10a and the intermediate portion 10c of the pillow beam 10, and at least the second pillow beam ribs 33H to 33J are disposed at the end portion 10b of the pillow beam 10. Yes. The first pillow beam ribs 33A to 33F are arranged on both sides of the second pillow beam ribs 33H to 33J in the vehicle width direction. A screw seat 37 to which a bolt B (see FIG. 1) for fixing the center pin 14 is screwed is provided on the upper surface of the pillow beam lower skin 32 in the central portion 10a of the pillow beam 10. The screw seat 37 is disposed in an internal space surrounded by the pillow beam upper skin 31, the pillow beam lower skin 32, and the first pillow beam ribs 33B and 33C. That is, two adjacent first pillow ribs 33B and 33C among the plurality of first pillow ribs 33A to 33F are arranged on the inner side in the vehicle width direction of the screw seat 37 and on the outer side in the vehicle width direction of the screw seat 37. Yes.

  Of the two first pillow beam ribs 33B and 33C disposed adjacent to the screw seat 37, the thickness T1 of the first pillow beam rib 33B disposed on the inner side in the vehicle width direction with respect to the screw seat 37 is: It is larger than the thickness T2 of the first pillow beam rib 33C disposed on the outer side in the vehicle width direction with respect to the screw seat 37. The first pillow ribs 33B disposed on the inner side in the vehicle width direction of the screw seat 37 extend in the vertical direction when viewed from the vehicle longitudinal direction. A joint portion between the extruded shape members 7A and 7B is disposed immediately above the first pillow beam rib 33B. The virtual extension line upward of the first pillow beam rib 33 </ b> B overlaps along the two second floor ribs 23 </ b> B of the floor board 7.

  The thickness T1 of the first pillow ribs 33B is larger than the distance L in the vehicle width direction between the opposing surfaces of the two adjacent second floor ribs 23B. The vehicle width direction center of the first pillow beam rib 33B coincides with the vehicle width direction center between the two adjacent second floor ribs 23B in the vehicle longitudinal direction position. The end portion 12a of the first middle beam 12 is overlapped with the end surface of the first pillow beam rib 33B on one side in the vehicle longitudinal direction. The end portion 13a of the second intermediate beam 13 is overlaid on the end surface on the other side in the vehicle longitudinal direction of the first pillow beam rib 33B. That is, the first middle beam 12 and the second middle beam 13 are arranged on a virtual extension line in the vehicle longitudinal direction of the first pillow beam rib 33B.

  The first pillow beam rib 33 </ b> C arranged on the outer side in the vehicle width direction of the screw seat 37 extends obliquely upward and outward in the vehicle width direction. The inclination angle θ1 with respect to the vertical direction of the first pillow rib 33C is the same as or smaller than the inclination angle θ2 with respect to the vertical direction of the first floor rib 23A. In the present embodiment, θ1 <θ2. The virtual extension line BL2 of the first pillow beam rib 33C overlaps with the virtual extension line FL1 of two adjacent floor ribs 23A extending at different angles in the region X where the floor lower skin 22 and the pillow beam appaskin 31 are combined.

  A first pillow beam rib 33D is connected to a bent portion 32d where the inclined portion 32a and the central flat portion 32b of the pillow beam lower skin 32 intersect. The first pillow beam rib 33D extends in the vertical direction. A first pillow beam rib 33E is connected to a bent portion 32e where the inclined portion 32a and the end flat portion 32c of the pillow beam lower skin 32 intersect. The first pillow beam rib 33E is inclined in a direction extending upward and inward in the vehicle width direction. A joint portion between the extruded shape members 7B and 7C is arranged just above the intersection of the first pillow rib 33E with the pillow beam upskin 31. The virtual extension line of the first pillow beam rib 33E overlaps with the virtual extension lines of the two second floor ribs 23B of the floor board 7 in the region where the floor lower skin 22 and the pillow beam appaskin 31 are combined. Specifically, the virtual extension line of the first pillow rib 33E overlaps the virtual extension line of one first floor rib 23B and overlaps with the virtual extension line of another first floor rib 23B in the region. Overlapping along the line.

  The ratio of the number of the pillow beam ribs 33 extending in the vertical direction out of the number of the pillow beam ribs 33 arranged at the end portion 10 b of the pillow beam 10 is the number of the pillow beam ribs 33 arranged at the center portion 10 a of the pillow beam 10. The ratio of the number of pillow beam ribs 33 extending in the vertical direction is greater than the ratio of In the present embodiment, all the pillow beam ribs 33 arranged at the end portion 10b of the pillow beam 10 extend in the vertical direction. At the end portion 10 b of the pillow beam 10, the pillow beam lower skin 32 has a protruding end portion 32 f that protrudes outward in the vehicle width direction from the pillow beam upper skin 31. The protruding end portion 32 f of the pillow beam lower skin 32 is overlapped with the spacer 17 welded to the lower surface of the side beam 8 from below and is welded to the spacer 17. Note that the protruding end portion 32 f of the pillow beam lower skin 32 may be directly welded to the side beam 8 without using the spacer 17.

  According to the configuration described above, the first pillow ribs 33 </ b> A to 33 </ b> F have the virtual extension lines BL <b> 1 and BL <b> 2 in the region X where the floor lower skin 22 and the pillow beam appaskin 31 are combined when viewed from the longitudinal direction of the vehicle. It arrange | positions in the position which overlaps virtual extension line FL1, FL2 of floor rib 23A, 23B. Therefore, when the load generated on the pillow beam 10 or the floor board 7 is transmitted between the first pillow beam ribs 33A to 33F and the floor ribs 23A and 23B, the transmission path of the load is offset in the vehicle width direction. Is prevented. Therefore, it is possible to suppress the load from being transmitted in the vehicle width direction in the floor lower skin 22 and the pillow beam upskin 31, and to suppress the insufficient strength of the welded portion W due to the stress generated in the floor lower skin 22 and the pillow beam upskin 31.

  In addition, since the first pillow ribs 33A to 33F are arranged at the central portion 10a of the pillow beam 10, a load in the longitudinal direction of the vehicle is transmitted from the carriage 3 to the pillow beam 10 via the center pin 14 by acceleration / deceleration of the vehicle. When this is done, the load is smoothly transmitted from the first pillow ribs 33A to 33F to the floor ribs 23A and 23B. Further, when a downward load is applied to the central portion 10a and the intermediate portion 10c of the pillow beam 10 and bending stress is generated in the pillow beam 10, the load is smoothly applied to the floor ribs 23A and 23B from the first pillow ribs 33A to 33F. Is transmitted. Therefore, in the vicinity of a portion of the pillow beam 10 where a large load can be generated, insufficient strength of the welded portion W between the floor plate 7 and the pillow beam 10 can be reduced.

  In addition, since the first pillow beam ribs 33A to 33F are disposed on both sides of the second pillow beam rib 33H in the vehicle width direction, the bonding strength between the pillow beam 10 and the floor board 7 by the first pillow beam ribs 33A to 33F. The shape of the pillow beam 10 can be maintained by the second pillow beam rib 33H. Two adjacent first pillow ribs 33B and 33C among the plurality of first pillow ribs 33A to 33F are arranged on the inner side in the vehicle width direction of the screw seat 37 and on the outer side in the vehicle width direction of the screw seat 37. Therefore, when the load is transmitted from the carriage 1 to the pillow beam 10 via the center pin 14, the first pillow beam ribs 33B and 33C arranged adjacent to both sides in the vehicle width direction of the screw seat 37 smoothly transfer the load. Can be transmitted to the floor plate 7 to reduce the insufficient strength of the welded portion W between the floor plate 7 and the pillow beam 10.

  Of the two first pillow beam ribs 33B and 33C disposed adjacent to the screw seat 37, the thickness T1 of the first pillow beam rib 33B disposed on the inner side in the vehicle width direction with respect to the screw seat 37. Is larger than the thickness T2 of the first pillow beam rib 33C disposed on the outer side in the vehicle width direction with respect to the screw seat 37, so that the vehicle is moved from the carriage 3 to the pillow beam 10 via the center pin 14 by acceleration / deceleration of the vehicle. When the load in the longitudinal direction is transmitted, the thick first pillow ribs 33B disposed adjacent to the inside of the screw seat 37 in the vehicle width direction can stably receive the load.

  Of the two first pillow beam ribs 33B and 33C disposed adjacent to the screw seat 37, the first pillow beam rib 33B disposed on the inner side in the vehicle width direction with respect to the screw seat 37 is the longitudinal direction of the vehicle body. Since it overlaps with the end portions 12a and 13a of the first middle beam 12 and the second middle beam 13 when viewed from the direction, the first middle beam 12 and the second middle beam 13 are connected to the pillow beam 10 or from the pillow beam 10 to the first middle beam. When a load in the vehicle longitudinal direction is transmitted to the beam 12 and the second intermediate beam 13, the first pillow beam rib 33B disposed adjacent to the inner side in the vehicle width direction of the screw seat 37 stably transmits the load. Can do.

  Of the two first pillow beam ribs 33B and 33C arranged adjacent to the screw seat 37, the first pillow beam rib 33C arranged on the outer side in the vehicle width direction with respect to the screw seat 37 is above and Since it extends obliquely outward in the vehicle width direction, when a load in the vehicle width direction is transmitted from the carriage 1 to the pillow beam 10 via the center pin 14, the screw seat 37 is disposed adjacent to the vehicle width direction outside. Further, the first pillow beam rib 33C can smoothly transmit the load in the extending direction, and buckling of the first pillow beam rib 33C can be prevented.

  Moreover, the 1st pillow beam rib 33E connected to the bending part 32e where the inclination part 32a and the edge flat part 32c cross | intersect among several 1st pillow beam ribs 33A-F is extended upwards, and the vehicle width direction inside. In the structure in which the pillow beam lower skin 32 has the inclined portion 32a in the intermediate portion 32c, the pillow beam 10 is bent even if a downward load is applied to the intermediate portion 10c of the pillow beam 10 and bending stress is generated in the pillow beam 10. The first pillow beam rib 33E connected to the portion 32e can smoothly transmit the load in the extending direction, and buckling of the first pillow beam rib 33E can be prevented.

DESCRIPTION OF SYMBOLS 1 Railcar 3 Bogie 6 Underframe structure 7 Floor board 10 Pillow beam 10a Center part 10b End part 10c Middle part 12 1st middle beam 13 2nd middle beam 14 Center pin 16 Air spring 21 Floor upper skin 22 Floor lower skin 23 Floor rib 23A 1st 1 floor rib 23B 2nd floor rib 31 pillow beam upper skin 32 pillow beam lower skin 32a inclined portion 32c end flat portion 32e bent portion 33 pillow beam ribs 33A to F first pillow beam ribs 33H to J second pillow beam ribs 37 screw seat B Bolt BL1, BL2, BL3 Virtual extension line FL1, FL2 Virtual extension line T1, T2 Thickness X area

Claims (8)

A floor plate having a floor upper skin, a floor lower skin disposed below the floor upper skin, and a plurality of floor ribs connected to the floor upper skin and the floor lower skin, the floor rib extending in the longitudinal direction of the vehicle;
A pillow beam upper skin, a pillow beam lower skin disposed below the pillow beam upper skin, and a plurality of pillow beam ribs connected to the pillow beam upper skin and the pillow beam lower skin, wherein the pillow beam rib is longitudinal in the vehicle. A pillow beam extending in the direction,
Edges on both sides in the vehicle longitudinal direction of the pillow beam appaskin are welded to the lower surface of the floor lower skin,
The plurality of pillow beam ribs includes a plurality of first pillow beam ribs;
The first pillow beam rib is disposed at a position where the virtual extension line overlaps with the virtual extension line of the floor rib in a region where the floor lower skin and the pillow beam appaskin are combined when viewed from the longitudinal direction of the vehicle. , Undercarriage structure of railway vehicles. The plurality of pillow beam ribs further includes a plurality of second pillow beam ribs,
The second pillow beam rib is arranged at a position where the virtual extension line is separated from the virtual extension line of the floor rib in a region where the floor lower skin and the pillow beam appaskin are combined, as viewed from the longitudinal direction of the vehicle.
The pillow beam has, in the vehicle width direction, a central portion to which a central pin connected to the carriage is fixed, an end portion supported by the carriage from below via an air spring, the central portion and the end portion, An intermediate portion between,
At least the first pillow beam rib is disposed in the central portion and the intermediate portion,
The railcar frame structure according to claim 1, wherein at least the second pillow beam rib is disposed at the end.   The undercarriage structure of a railway vehicle according to claim 2, wherein the first pillow beam ribs are disposed on both sides of the second pillow beam ribs in the vehicle width direction. A screw seat on which a bolt for fixing the center pin is screwed is provided at the center of the pillow beam,
The adjacent two first pillow ribs among the plurality of first pillow ribs are arranged on the inner side in the vehicle width direction of the screw seat and on the outer side in the vehicle width direction of the screw seat. Railcar frame structure as described in 1.   Of the two first pillow ribs disposed adjacent to the screw seat, the thickness of the first pillow rib disposed on the inner side in the vehicle width direction with respect to the screw seat is smaller than that of the screw seat. The railcar frame structure according to claim 4, wherein the frame structure is larger than the thickness of the first pillow beam rib disposed on the outer side in the vehicle width direction. Further comprising a middle beam joined to the pillow beam and extending in the longitudinal direction of the vehicle,
Of the two first pillow beam ribs disposed adjacent to the screw seat, the first pillow beam rib disposed on the inner side in the vehicle width direction with respect to the screw seat overlaps the end portion of the center beam. The frame structure of a railway vehicle according to claim 4 or 5.   Of the two first pillow ribs arranged adjacent to the screw seat, the first pillow rib arranged on the outer side in the vehicle width direction with respect to the screw seat is upward and outward in the vehicle width direction. The railcar frame structure according to any one of claims 4 to 6, wherein the railcar frame structure extends obliquely toward the railcar. The pillow beam appaskin is flat,
The vertical dimension of the central part is larger than the vertical dimension of the end part,
The pillow beam lower skin is provided in the intermediate portion, and has an inclined portion extending obliquely downward and inward in the vehicle width direction, and a flat portion continuous to the vehicle width direction outer side of the inclined portion,
The first pillow beam rib connected to a bent portion where the inclined portion and the flat portion intersect among the plurality of first pillow beam ribs is inclined in a direction extending upward and inward in the vehicle width direction. The railcar frame structure according to any one of 2 to 7.

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