CN110682931A

CN110682931A - Car body chassis and have its tram

Info

Publication number: CN110682931A
Application number: CN201911030252.8A
Authority: CN
Inventors: 王晶晶; 黄鹏; 毕海涛; 向俊龙; 陈晨; 刘威
Original assignee: China Railway Transit Equipment Co Ltd
Current assignee: China Railway Transit Equipment Co Ltd
Priority date: 2019-10-28
Filing date: 2019-10-28
Publication date: 2020-01-14
Anticipated expiration: 2039-10-28
Also published as: CN110682931B

Abstract

The invention provides a vehicle body chassis and a tramcar with the same, wherein the vehicle body chassis comprises: the sleeper beam comprises an outer frame and a sleeper beam arranged in the outer frame, wherein two ends of the sleeper beam are fixedly connected to the outer frame; the two ends of the first longitudinal beam structure are fixedly connected to the left side face of the sleeper beam and the part, located on the left side of the sleeper beam, in the outer frame respectively; the two ends of the second longitudinal beam structure are fixedly connected to the right side face of the sleeper beam and the part, located on the right side of the sleeper beam, in the outer frame respectively; the two vertical shock absorber mounting seats are fixedly arranged at the left end part of the first longitudinal beam structure, and the other vertical shock absorber mounting seat is fixedly arranged at the right end part of the second longitudinal beam structure; in conclusion, the vertical shock absorber mounting seat is not mounted on the sleeper beam, so that the impact force on the sleeper beam can be relieved, and the mechanical property of the sleeper beam can be well improved.

Description

Car body chassis and have its tram

Technical Field

The invention relates to the technical field of rail transit, in particular to a vehicle body underframe and a tramcar with the same.

Background

The tramcar is a common public transport means, and is generally formed by interconnecting a plurality of carriages, a car body underframe is generally arranged at the bottom of each carriage, the upper space of the car body underframe is generally used for carrying passengers and the like, a sleeper beam is generally arranged at the lower side of the car body underframe, and a bogie is generally arranged at the lower side of the sleeper beam.

Disclosure of Invention

The invention aims to provide a vehicle body underframe and a tramcar with the same.

In order to achieve one of the above objects, an embodiment of the present invention provides a vehicle body underframe including: the sleeper beam comprises an outer frame and a sleeper beam arranged in the outer frame, wherein two ends of the sleeper beam are fixedly connected to the outer frame; the two ends of the first longitudinal beam structure are fixedly connected to the left side face of the sleeper beam and the part, located on the left side of the sleeper beam, in the outer frame respectively; the two ends of the second longitudinal beam structure are fixedly connected to the right side face of the sleeper beam and the part, located on the right side of the sleeper beam, in the outer frame respectively; and one of the two vertical shock absorber mounting seats is fixedly arranged at the left end part of the first longitudinal beam structure, and the other one of the two vertical shock absorber mounting seats is fixedly arranged at the right end part of the second longitudinal beam structure.

As a further improvement of an embodiment of the present invention, the present invention further includes: a floor fixedly connected to upper sides of the outer frame, the bolster, the first rail structure, and the second rail structure.

As a further improvement of an embodiment of the present invention, the present invention further includes: and the front-back direction and the left-right direction are mutually vertical directions in a horizontal plane.

As a further improvement of an embodiment of the present invention, the anti-roll torsion bar mount includes: vertical plates and horizontal plates; the transverse plate is provided with a plurality of mounting holes, a first side edge of the transverse plate is vertically connected to the vertical plate, a second side edge of the transverse plate is fixedly connected to the front side surface or the rear side surface of the first longitudinal beam structure, and the first side edge and the second side edge are opposite two side edges; the vertical plates and the horizontal plates are fixedly connected with the sleeper beam.

As a further improvement of an embodiment of the present invention, the outer frame is rectangular and is composed of two opposite end beams and two opposite side beams; the left end part of the first longitudinal beam structure is fixedly connected to one end beam, the right end part of the second longitudinal beam structure is fixedly connected to the other end beam, and the first longitudinal beam structure and the second longitudinal beam structure are coaxial; and two ends of the sleeper beam are respectively and fixedly connected to the two side beams.

As a further improvement of one embodiment of the present invention, the first cross beam has two ends respectively fixedly connected to the left end portion and one side beam of the first longitudinal beam structure, and a vertical shock absorber mounting seat is arranged on the lower side of the first cross beam; and two ends of the second cross beam are respectively and fixedly connected to the right end part of the second longitudinal beam structure and the other side beam, and a vertical shock absorber mounting seat is arranged on the lower side of the second cross beam.

As a further improvement of an embodiment of the present invention, the floor panel is fixedly attached to upper side surfaces of the first and second cross members.

As a further improvement of the embodiment of the present invention, the end beam, the side beam, the first cross beam and the second cross beam are all hollow sections provided with reinforcing ribs.

As a further improvement of an embodiment of the present invention, both end beams are fixedly provided with a hinge base.

The embodiment of the invention also provides the tramcar which is provided with the car body underframe.

Compared with the prior art, the invention has the technical effects that: the invention provides a vehicle body underframe and a tramcar with the same.

Drawings

FIG. 1 is a schematic structural view of a frame base in an embodiment of the present invention;

FIG. 2A is a schematic view of a bolster in an embodiment of the present invention;

FIG. 2B is an enlarged view of area A in FIG. 2A;

FIGS. 3A and 3B are schematic structural views of an anti-roll torsion bar mounting seat in an embodiment of the present invention;

FIG. 4 is a schematic structural view of a first beam and vertical shock absorber mount in an embodiment of the present invention;

FIG. 5A is a schematic structural view of an end beam according to an embodiment of the present invention;

FIG. 5B is an enlarged view of area B in FIG. 5A;

FIG. 6 is a schematic view of a hinge mount in an embodiment of the invention;

fig. 7 is a schematic structural view of a side member in the embodiment of the invention.

Detailed Description

The present invention will be described in detail below with reference to embodiments shown in the drawings. These embodiments are not intended to limit the present invention, and structural, methodological, or functional changes made by those skilled in the art according to these embodiments are included in the scope of the present invention.

Terms such as "upper," "above," "lower," "below," and the like, used herein to denote relative spatial positions, are used for ease of description to describe one element or feature's relationship to another element or feature as illustrated in the figures. The spatially relative positional terms may be intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if the device in the figures is turned over, elements described as "below" or "beneath" other elements or features would then be oriented "above" the other elements or features. Thus, the exemplary term "below" can encompass both an orientation of above and below. The device may be otherwise oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein interpreted accordingly.

Also, it should be understood that, although the terms first, second, etc. may be used herein to describe various elements or structures, these described elements should not be limited by these terms. These terms are only used to distinguish these descriptive objects from one another. For example, the first stringer structure may be referred to as a second stringer structure, and similarly the second stringer structure may also be referred to as a first stringer structure, without departing from the scope of the present application.

In the drawings attached to the present specification, directions such as "up" and "down" are denoted, and during operation of the tramcar, the direction away from the ground is "up" and the direction toward the ground is "down".

The embodiment of the present invention further provides a vehicle body underframe, including:

the frame comprises an outer frame 11 and a sleeper beam 12 arranged inside the outer frame 11, wherein both ends of the sleeper beam 12 are fixedly connected to the outer frame 11; a first longitudinal beam structure 13A, both ends of which are fixedly connected to the left side surface of the bolster 12 and a portion of the outer frame 11 on the left side of the bolster 12, respectively; a second longitudinal beam structure 13B whose both ends are fixedly connected to the right side surface of the bolster 12 and a portion of the outer frame 11 on the right side of the bolster 12, respectively; and two vertical shock absorber mounting seats 141, one of which is fixedly arranged at the left end part of the first longitudinal beam structure 13A, and the other of which is fixedly arranged at the right end part of the second longitudinal beam structure 13B.

Here, the bolster 12 divides the outer frame 11 into a left side portion and a right side portion, and in a vehicle compartment, a vertical damper is generally installed below the vertical damper installation seat 141, and during the operation of the tramcar, there is a possibility that a vibration in a vertical direction may be generated, and the vertical damper can buffer the vibration, and it can be understood that the vertical damper installation seat 141 may bear a large impact force, whereas in the present embodiment, the vertical damper installation seat 141 is not installed on the bolster 12, so that the impact force received by the bolster 12 can be reduced, and the mechanical property of the bolster 12 can be improved well.

Here, in practice, the floor 2 is attached to the vehicle body underframe, the space above the floor 2 is used for passenger transportation, and the side wall and/or the end wall are attached to the outer frame 11. Optionally, the vehicle body underframe is made of an aluminum alloy material.

Here, as shown in fig. 2A, the bolster 12 may be made by welding two identical sections 121, and the production process may be: step 1, firstly, machining a section 121, for example, forming a plug welding groove 125, a center pin mounting bolt hole 124, a center pin positioning hole 123, an air inlet hole 122 on an air spring mounting surface, and the like; step 2, machining the mounting surface of the air spring and the mounting surface of the center pin to ensure the flatness of the mounting surfaces; and 3, splicing the two sections 121, and then welding along the splicing seams to obtain the sleeper beam 12 shown in fig. 2A.

In this embodiment, the method further includes: and a floor panel 2 fixedly attached to upper side surfaces of the outer frame 11, the bolster 12, the first side member structure 13A, and the second side member structure 13B. As shown in fig. 1, the first and second longitudinal beam structures each include two longitudinal beams arranged in parallel, and alternatively, each longitudinal beam may have an inverted T-shaped cross section, and the tip of the inverted T-shaped cross section is welded to a rib on the bottom side of the floor panel 2.

Here, fig. 2B shows a schematic structural view of the profile 121 on the left side, and it can be understood that the profile 121 on the right side is similarly structured. The section bar 121 on the left side has a rectangular cross section and is a hollow structure with reinforcing ribs arranged inside, the top surface of the section bar 121 extends towards the left and forms a second upper transverse plate 1211, the bottom surface extends towards the left and forms a second lower transverse plate 1212, and the upper surface of the second upper transverse plate 1211 is provided with a welding groove 125, so that the section bar 121 is connected with the floor 2 in a plug welding manner through the welding groove 125; the bottom of the inverted T shape is welded to the upper surface of the second lower cross plate 1212 and the tip is welded to the lower surface of the second upper cross plate 1211.

In this embodiment, the method further includes: and two anti-roll torsion bar mounting seats 15 arranged at the right end part of the first longitudinal beam structure 13A, wherein one of the anti-roll torsion bar mounting seats is fixedly connected with the front side surface of the first longitudinal beam structure 13A and the sleeper beam 12, the other one of the anti-roll torsion bar mounting seats is fixedly connected with the rear side surface of the first longitudinal beam structure 13A and the sleeper beam 12, and the front-back direction and the left-right direction are mutually vertical in a horizontal plane.

Here, in the actual railcar car, the anti-roll torsion bar is attached to the lower side of the anti-roll torsion bar attachment seat 15, and the anti-roll torsion bar is subjected to a large stress during the operation of the railcar, and it is understood that since the anti-roll torsion bar attachment seat 15 is fixedly connected to both the first side member structure 13A and the body bolster 12, the anti-roll torsion bar attachment seat 15 disperses the stress to the first side member structure 13A and the body bolster 12, so that the impact force applied to the body bolster 12 can be further reduced, and the mechanical properties of the body bolster 12 can be improved.

Furthermore, it will be appreciated that the two anti-roll torsion bar mounts 15 can also function as a reinforcement plate, i.e., to increase the strength of the connection between the first side rail structure 13A and the bolster 12.

In this embodiment, the anti-roll torsion bar mounting seat 15 includes: vertical plates 151 and horizontal plates 152; a plurality of mounting holes 1521 are formed in the transverse plate 152, a first side edge of the transverse plate 152 is vertically connected to the vertical plate 151, a second side edge of the transverse plate is fixedly connected to a front side surface or a rear side surface of the first longitudinal beam structure 13A, and the first side edge and the second side edge are opposite two side edges; the vertical plates 151 and the horizontal plates 152 are fixedly connected with the sleeper beam 12.

Here, fig. 3A and 3B show an anti-roll torsion bar mount 15 including: the vertical plates 151 and the horizontal plates 152 which are connected in a mutually perpendicular mode are provided with a plurality of mounting holes 1521 on the horizontal plates 152, and therefore the anti-rolling torsion bars can be mounted in the mounting holes 1521. Here, in fig. 3A and 3B, the number of the mounting holes 1521 is four, the vertical plate 151 and the horizontal plate 152 are arc-welded, and a groove may be provided on the horizontal plate 152 in order to increase the strength of the arc welding.

Here, anti-roll torsion bar mount 15 shown in fig. 3A is located on the rear side of first side member structure 13A, connected to the rear side of first side member structure 13A at the front side of lateral plate 152, connected to bolster 12 at the right side, and connected to bolster 12 at the right side of vertical plate 151. Anti-roll bar mounts 15 are shown in fig. 3B on the front side of first longitudinal beam structure 13A, with the rear side of transverse plate 152 attached to the front side of first longitudinal beam structure 13A, the right side attached to bolster 12, and the right side of vertical plate 151 attached to bolster 12. Here, as shown in fig. 3A and 3B, the height (height in the up-down direction) of the right portion 1511 of the vertical plate 151 is low in the left-right direction, so that the right portion 1511 can be inserted between the second lower cross plate 1212 and the second upper cross plate 1211 in fig. 2B, and, in order to improve the coupling strength, the lower side of the right portion 1511 may be welded to the upper surface of the second lower cross plate 1212, and the upper side of the right portion 1511 may be welded to the lower surface of the second upper cross plate 1211.

Alternatively, the upper side of the vertical plate 151 and the floor panel 2 may be connected by butt welding.

In this embodiment, the outer frame 11 is rectangular and is composed of two opposite end beams 11A and two opposite side beams 11B; the left end part of the first longitudinal beam structure 13A is fixedly connected to one end beam 11A, the right end part of the second longitudinal beam structure 13B is fixedly connected to the other end beam 11A, and the first longitudinal beam structure and the second longitudinal beam structure are coaxial; both ends of the bolster 12 are fixedly connected to the side sills 11B, respectively.

Here, as shown in fig. 1, the side member 11B is longer than the end member 11A. As shown in fig. 2A, the front and rear ends of the body bolster 12 are each provided with a reinforcement plate 126, and one side of the reinforcement plate 126 is fixedly connected to the body bolster 12 and the other side is fixedly connected to the side member 11B, so that the connection strength between the body bolster 12 and the side member can be improved.

As shown in fig. 5A and 5B, the end beam 11A includes: the first frame body 11A1 and the second frame body 11A2 are both rectangular in cross section and are both hollow structures with reinforcing ribs arranged inside; in the vertical direction, the size of the first frame 11a1 is larger than that of the second frame 11a2, the first frame 11a1 is connected to the second frame 11a2 on the side facing the bolster 12, and the bottom surfaces of the first and second frames are the same plane; the bottom surface of the second frame 11A2 extends toward the bolster 12 to form a first lower cross plate 11A21, the top surface extends toward the bolster 12 to form a first upper cross plate 11A22, and the upper surface of the first upper cross plate 11A22 is provided with a welding groove 125, so that the first end beam 11A is plug-welded to the floor 2 through the welding groove 125. The bottom edges of the longitudinal beams in the first and second longitudinal beam structures are welded to the upper surface of the first lower transverse plate 11a21, and the tip portions are welded to the lower surface of the first upper transverse plate 11a 22.

Here, a plurality of ribs 1111 are provided inside the first housing 11a1, one end of each of the ribs 1111 is connected to the side of the first housing 11a1, and the other end is connected to each other, for example, in fig. 5B, five ribs 1111 are provided in the first housing 11a1, one rib 1111 is connected to the upper side, one rib 1111 is connected to the left side, one rib 1111 is connected to the bottom side, one rib 1111 is connected to the boundary between the bottom side and the right side, and one rib 1111 is connected to the boundary between the right side and the upper side of the second housing 11a 2.

Here, a plurality of ribs 1111 are provided inside the second housing 11a2, for example, in fig. 5B, one rib 1111 is provided inside the second housing 11a2, a boundary between the left side and the upper side is connected to one end of the rib 1111, and a boundary between the bottom side and the right side is connected to the other end of the rib 1111.

Optionally, the first frame body and the second frame body are integrally formed, and the tip of the longitudinal beam is provided with a groove and is welded to the lower surface of the first upper transverse plate 11a22 based on the groove.

In this embodiment, the first cross beam 14L has two ends respectively fixedly connected to the left end portion of the first longitudinal beam structure 13A and the side beam 11B, and a vertical shock absorber mounting seat 141 is provided on the lower side thereof; the second cross member 14R has both ends fixedly connected to the right end portion of the second side member structure 13B and the other side member 11B, respectively, and is provided with a vertical damper mount 141 on the lower side thereof. Here, the stress applied to the left vertical damper mount 141 is dispersed to the first side member structure 13A and the one side member 11B, and the stress applied to the right vertical damper mount 141 is dispersed to the second side member structure 13B and the other side member 11B, so that the stress can be dispersed, and the strength of the vehicle body underframe can be improved.

Here, as fig. 4 shows the structure of the first cross member 14L and the vertical damper mount 141 mounted thereon, it is understood that the structure of the second cross member 14R and the vertical damper mount 141 mounted thereon is also similar. The first cross member 14L is a profile structure (for example, a large-section aluminum alloy profile), a box-shaped joist 14L1 is provided below the profile, and a vertical damper mount 141 is attached below the box-shaped joist 14L 1. Further, as shown in fig. 4, the vertical damper mount 141 is further provided with: the box-shaped trabecula 14L1 is also provided with a hole 1411 penetrating through the box-shaped trabecula, wherein the hole is communicated with the threading hole 1411, and then the hole horizontally extends to the right and is communicated with the threading pipeline 14L2 so as to install the wiring harness.

The production process can be as follows: 1. machining the extruded section to form a concave notch; 2. the concave notch is provided with a box-shaped trabecula 14L1, and the box-shaped trabecula 14L1 is connected with the section by arc welding; 3. four bolt holes are formed in the upper surface of the box-shaped joist 14L1, and the shock absorber mounting base 141 is connected through the four bolt holes; 4. the line passing duct 14L2 is installed.

In this embodiment, the floor 2 is fixedly connected to the upper sides of the first and second cross members. Here, the floor panel 2 is also fixedly connected to the upper sides of the first and second cross members, so that the strength of the floor panel 2 can be improved.

In this embodiment, the end beam 11A, the side beam 11B, the first cross beam 14L, and the second cross beam 14R are all hollow sections provided with reinforcing ribs.

In this embodiment, as shown in fig. 1, the two end beams 11A are both fixedly provided with the hinge base 3. Here, in practice, the connection between adjacent cars is usually required by a connecting device, and the hinge base 3 is used for connection with the connecting device. The hinge base 3 may be made of high strength carbon steel and may be made by welding several steel plates.

Here, fig. 5 shows a structural view of the hinge base 3, the hinge base 3 including: the upper plate and the lower plate are arranged in parallel, the first vertical plate 33 is arranged between the upper plate and the lower plate, the upper side edge and the lower side edge of the first vertical plate 33 are fixedly connected to the upper plate 32 and the lower plate 31 respectively, the second vertical plate 34 is positioned on the left side of the first plate 33, and the upper side edge and the lower side edge of the second vertical plate are also fixedly connected to the upper plate 32 and the lower plate 31 respectively.

As shown in fig. 6, a plurality of holes 35 are respectively formed in the upper and lower plates, and as shown in fig. 5A, corresponding holes 11A3 are also respectively formed in the upper and lower sides of the first end beam 11A, and the positions of the holes 35 and 11A3 need to be corresponded, so that when installing, the holes 35 and 11A3 are aligned and then connected by rivets.

As shown in fig. 5A, in the front-rear direction, three sets of holes are formed in the first riser 33, where each set includes a plurality of holes 11A3, two sets of holes 11A3 on the left and right sides are rivet holes, and one set of holes 11A3 in the middle is bolt holes; it can be understood that three groups of holes are correspondingly formed in the first vertical plate 33, each group of holes includes a plurality of holes, two groups of holes located on the left side and the right side are rivet holes, and a group of holes located in the middle are bolt holes. It can be understood that when the three groups of holes are installed, the three groups of holes are respectively corresponding, the two groups of holes on the left side and the right side are connected by rivets, and the middle group of holes is connected by bolts.

Fig. 7 shows a schematic structural view of a side beam 11B, and the side beam 11B is a hollow structure provided with reinforcing ribs inside, and is further provided with a side wall mounting interface 11B1 and a floor 2 mounting interface 11B 2.

Here, as shown in fig. 1, each of the first side member structure 13A and the second side member structure 13B includes two side members arranged in parallel, and in fig. 1, reinforcing plates are provided at the joints between the two side members and the end member 11A and at the joints between the two side members and the bolster 12.

The second embodiment of the invention provides a tramcar which is provided with the car body underframe in the first embodiment. Optionally, the tramcar is a high-floor tramcar.

It should be understood that although the present description refers to embodiments, not every embodiment contains only a single technical solution, and such description is for clarity only, and those skilled in the art should make the description as a whole, and the technical solutions in the embodiments can also be combined appropriately to form other embodiments understood by those skilled in the art.

The above-listed detailed description is only a specific description of a possible embodiment of the present invention, and they are not intended to limit the scope of the present invention, and equivalent embodiments or modifications made without departing from the technical spirit of the present invention should be included in the scope of the present invention.

Claims

1. A vehicle body underframe, comprising:

the device comprises an outer frame (11) and a sleeper beam (12) arranged inside the outer frame (11), wherein two ends of the sleeper beam (12) are fixedly connected to the outer frame (11);

a first longitudinal beam structure (13A) having both ends fixedly connected to the left side surface of the bolster (12) and a portion of the outer frame (11) on the left side of the bolster (12), respectively;

a second longitudinal beam structure (13B) having both ends fixedly connected to the right side surface of the bolster (12) and a portion of the outer frame (11) on the right side of the bolster (12), respectively;

and two vertical shock absorber mounting seats (141), wherein one vertical shock absorber mounting seat is fixedly arranged at the left end part of the first longitudinal beam structure (13A), and the other vertical shock absorber mounting seat is fixedly arranged at the right end part of the second longitudinal beam structure (13B).

2. The vehicle body chassis of claim 1, further comprising:

a floor (2) fixedly connected to upper sides of the outer frame (11), the bolster (12), the first side rail structure (13A), and the second side rail structure (13B).

3. The vehicle body chassis of claim 2, further comprising:

and two anti-rolling torsion bar mounting seats (15) arranged at the right end part of the first longitudinal beam structure (13A), wherein one of the two anti-rolling torsion bar mounting seats is fixedly connected with the front side surface of the first longitudinal beam structure (13A) and the sleeper beam (12), the other one of the two anti-rolling torsion bar mounting seats is fixedly connected with the rear side surface of the first longitudinal beam structure (13A) and the sleeper beam (12), and the front-back direction and the left-right direction are mutually vertical in a horizontal plane.

4. The vehicle body chassis according to claim 3, wherein the anti-roll torsion bar mount (15) comprises:

vertical plates (151) and transverse plates (152);

the transverse plate (152) is provided with a plurality of mounting holes (1521), a first side edge of the transverse plate (152) is vertically connected to the vertical plate (151), a second side edge of the transverse plate is fixedly connected to the front side surface or the rear side surface of the first longitudinal beam structure (13A), and the first side edge and the second side edge are opposite;

the vertical plates (151) and the transverse plates (152) are fixedly connected with the sleeper beam (12).

5. The vehicle body chassis of claim 3, wherein:

the outer frame (11) is rectangular and consists of two opposite end beams (11A) and two opposite side beams (11B);

the left end part of the first longitudinal beam structure (13A) is fixedly connected to one end beam (11A), the right end part of the second longitudinal beam structure (13B) is fixedly connected to the other end beam (11A), and the first longitudinal beam structure and the second longitudinal beam structure are coaxial; and two ends of the sleeper beam (12) are fixedly connected to the two side beams (11B) respectively.

6. The vehicle body chassis of claim 5, further comprising:

a first cross beam (14L), two ends of which are respectively fixedly connected to the left end part of the first longitudinal beam structure (13A) and a side beam (11B), and the lower side of which is provided with a vertical shock absorber mounting seat (141);

and a second cross member (14R) having both ends fixedly connected to the right end portion of the second side member structure (13B) and the other side member (11B), respectively, and provided with a vertical damper mount (141) at the lower side thereof.

7. The vehicle body chassis of claim 6, wherein:

the floor (2) is fixedly connected to the upper side surfaces of the first and second cross beams.

8. The vehicle body chassis of claim 7, wherein:

the end beam (11A), the side beam (11B), the first cross beam (14L) and the second cross beam (14R) are all hollow sections provided with reinforcing ribs.

9. The vehicle body chassis of claim 7, wherein:

two end beams (11A) are both fixedly provided with a hinged seat (3).

10. A tramcar, characterized in that a car body underframe according to any one of claims 1-9 is provided.