CN113479226A

CN113479226A - Carbon fiber composite material underframe structure of high-speed rail transit motor train unit body

Info

Publication number: CN113479226A
Application number: CN202110838598.1A
Authority: CN
Inventors: 谈源; 汤娟; 陈艳艳; 耿强华; 解恩泽; 王小清; 王瑞; 徐华
Original assignee: Changzhou New Intelligent Technology Co Ltd
Current assignee: Changzhou New Intelligent Technology Co Ltd
Priority date: 2021-02-07
Filing date: 2021-02-07
Publication date: 2021-10-08
Anticipated expiration: 2041-02-07
Also published as: CN113479226B; CN112829783A; CN112829783B

Abstract

The invention relates to the technical field of rail transit equipment, in particular to a carbon fiber composite underframe structure of a vehicle body of a rail transit high-speed motor train unit, which comprises the following components: the beam bodies are arranged on two sides of the bottom of the vehicle body and extend along the length direction of the vehicle body; the frame is connected with the beam bodies on the two sides along the width direction of the vehicle body; the sealing plate is at least fixedly connected with the frame to form a supporting plane of the bottom of the vehicle body; the beam body comprises a first supporting surface which supports the edge of the frame, and a gap is arranged between the top of the edge and the bottom of the sealing plate; the beam body is provided with a mounting cavity penetrating the length direction of the beam body at the bottom of the first supporting surface, one end of a connecting piece for connecting the beam body and the frame is positioned in the mounting cavity, and the other end of the connecting piece is positioned in the gap; wherein, the beam body, the frame and the sealing plate are all made of composite materials. The whole underframe structure of the invention adopts a composite material structure, the weight of the car body is effectively reduced, after the beam body and the frame are connected, the sealing plate is very convenient to install, and the whole structure is stable and beautiful.

Description

Carbon fiber composite material underframe structure of high-speed rail transit motor train unit body

The application is a divisional application with the application number of 202110168799.5, the application date of 2021, 2 months and 7 days, and the invention name of 'a carbon fiber composite underframe structure of a vehicle body of a rail transit high-speed motor train unit'.

Technical Field

The invention relates to the technical field of rail transit equipment, in particular to a carbon fiber composite underframe structure of a vehicle body of a rail transit high-speed motor train unit.

Background

At present, most of train body materials are made of stainless steel or aluminum alloy materials, the whole train body is divided into a side wall module, an end part module, a train roof module and a train underframe module, and then the side wall module, the end part module, the train roof module and the train underframe module are welded or assembled together, so that the whole train body bears force and transmits force, and the problems of material increase, over-design and the like are inevitably caused. With the rapid development of rail transit at home and abroad, the requirements of the industry on the performance of train safety, maintenance cost and the like are higher and higher. The body is the main body part of the train, so that the running resistance can be reduced by properly reducing the weight of the body, the energy required by traction and braking is saved, the dynamic performance of the train is improved, and the maintenance cost of the train and the track is reduced.

In view of the above requirements, the designer actively makes research and innovation based on the practical experience and professional knowledge that the engineering application of the products is rich for many years and by matching with the application of the theory, so as to design a carbon fiber composite underframe structure of the body of the rail transit high-speed motor train unit.

Disclosure of Invention

The invention provides a carbon fiber composite underframe structure of a vehicle body of a rail transit high-speed motor train unit, which has higher practical value.

In order to achieve the purpose, the invention adopts the technical scheme that:

the utility model provides a carbon fiber composite material chassis structure of high-speed EMUs automobile body of track traffic, includes:

the beam bodies are arranged on two sides of the bottom of the vehicle body and extend along the length direction of the vehicle body; the frame is connected with the beam bodies on two sides in the width direction of the vehicle body; the sealing plate is at least fixedly connected with the frame to form a supporting plane of the bottom of the vehicle body;

the beam body comprises a first supporting surface which supports the edge of the frame, and a gap is arranged between the top of the edge and the bottom of the sealing plate; the bottom of the first supporting surface of the beam body is provided with an installation cavity penetrating through the beam body in the length direction, one end of a connecting piece for connecting the beam body and the frame is positioned in the installation cavity, and the other end of the connecting piece is positioned in the gap;

the beam body, the frame and the sealing plate are all of composite material structures.

Furthermore, the hole site that supplies the connecting piece to link up on the roof beam body is the bar hole, and includes first section and second section, the width of first section is greater than the width of second section, first section supplies connecting piece tip top-down to get into the installation cavity, the lateral wall of second section is used for right the connecting piece tip carries on spacingly.

Further, the frame with the connecting portion that the shrouding was laminated is hollow body structure, the body structure passes through the removal of tip material and forms the frame the edge, the edge is including connecting wall and two reinforcing walls, two reinforcing wall symmetry set up in connecting wall both sides, connecting wall with roof beam body fixed connection.

The connecting seat comprises a plate body and two limiting plates, the two limiting plates are arranged in parallel and are vertically connected with the plate body, and the edge of the plate body forms an extension section relative to the limiting plates;

the extending section is fixedly connected with the beam body, the plate body is positioned between the two limiting plates and is arranged between the edge of the frame and the beam body, and the extending section, the beam body and the plate body are fixedly connected.

Furthermore, at least one through structural cavity is arranged on the beam body, and the structural cavity is arranged in parallel with the mounting cavity;

wherein at least one of the structural cavities is filled with a reinforcing rod body.

Furthermore, the sealing plate is formed by splicing a plurality of structural units distributed in a matrix;

splicing positions of two adjacent structural units along the length direction of the vehicle body are connected through a staggered splicing structure, the staggered splicing structure comprises a retracted area arranged on the edge of one structural unit and a convex edge arranged on the edge of the other adjacent structural unit, and the convex edge is attached to the retracted area to realize splicing;

and the splicing positions of two adjacent structural units along the width direction of the vehicle body are connected with the same frame.

Further, the frame comprises a main body and transition plates, the edges are arranged on the main body, the transition plates are arranged on the top of the main body, and the transition plates extend outwards relative to the main body at two ends of the length direction of the vehicle body;

the transition plate is fixed with the main body through a connecting piece, the structure units are fixed with the extending parts of the transition plate through connecting pieces, wherein the structure units are located at the edge positions of the transition plate and are provided with slope structures, the tops of the slope structures of the adjacent two structure units are in butt joint, and the bottoms of the slope structures form a space for accommodating the connecting pieces connected with the transition plate and the main body.

Further, roof beam body top upwards extends has the edge body, it is provided with the second holding surface to be close to the inside one side of automobile body along the body, the second holding surface supports the automobile body support frame, it is right along the body the automobile body support frame carries out the spacing of horizontal direction, just along the body embedding in the recess on automobile body support frame surface, with the smooth surface of automobile body support frame formation and automobile body side wall laminating.

Further, the outside that the roof beam body is located the automobile body both sides is provided with the cell body, the cell body sets up along automobile body length direction, the cell body is used for holding protruding portion on the automobile body side wall.

Further, the frame includes two horizontal pipe bodies arranged in parallel and a connecting structure for connecting the two horizontal pipe bodies.

Through the technical scheme of the invention, the following technical effects can be realized:

the whole underframe structure of the invention adopts a composite material structure, the weight of the car body is effectively reduced, the beam body and the frame form a framework of the underframe structure, the purposes of bearing and transferring force are realized through the connection of the connecting pieces, after the beam body and the frame are connected, the sealing plate is very convenient to mount, one part of the connecting piece for connecting the frame and the beam body is hidden in the mounting cavity, and the other part of the connecting piece is hidden in the gap between the sealing plate and the top of the frame edge, so that the aesthetic property of the whole car body structure is ensured; for the installation cavity design, the weight of the beam body is further reduced.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments described in the present invention, and for those skilled in the art, other drawings can be obtained according to the drawings without creative efforts.

FIG. 1 is a schematic diagram of relative positions of a vehicle body carbon fiber composite underframe structure of a rail transit high-speed motor train unit, a vehicle body support frame and a vehicle body side wall;

FIG. 2 is an enlarged view of a portion of FIG. 1 at A;

FIG. 3 is an enlarged view of a portion of the frame at the location of the edge to beam connection;

FIG. 4 is a schematic diagram of a hole site;

FIG. 5 is a schematic view of a frame edge configuration;

FIG. 6 is another schematic view of the frame edge configuration;

FIG. 7 is an enlarged view of a portion of FIG. 2 at B;

FIG. 8 is a schematic view of the connecting seat disposed in the middle of the beam;

FIG. 9 is a schematic view of the connecting base connecting two adjacent beams;

FIG. 10 is a schematic view of the connecting socket;

FIG. 11 is a schematic view of the installation of the reinforcing rod body;

FIG. 12 is a schematic view of the connection of the beam, frame and closure plate;

FIG. 13 is an enlarged view of a portion of FIG. 12 at C with a portion of the ledge omitted;

FIG. 14 is an enlarged view of a portion of FIG. 12 at D;

FIG. 15 is an enlarged view of a portion of FIG. 12 at E;

FIG. 16 is a schematic view of the connection of the beam body to the body support;

reference numerals:

1. a beam body; 11. a first support surface; 12. installing a cavity; 13. hole site; 13a, a first segment; 13b, a second segment; 14. a structural cavity; 15. reinforcing the rod body; 16. an edge body; 17. a second support surface; 18. a trough body; 2. a frame; 21. a connecting portion; 21a, a connecting wall; 21b, a reinforcing wall; 22. a transition plate; 23. a horizontal pipe body; 24. a connecting structure; 3. closing the plate; 31. a structural unit; 31a, a setback region; 31b, a convex edge; 4. a connecting seat; 41. a plate body; 41a, an extension section; 42. a limiting plate; 5. a vehicle body support frame; 6. the side wall of the vehicle body.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments.

In the description of the present invention, it should be noted that the orientations or positional relationships indicated by the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", and the like are based on the orientations or positional relationships shown in the drawings, and are only for convenience of description and simplification of description, but do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus, should not be construed as limiting the present invention.

As shown in fig. 1-16, a carbon fiber composite underframe structure for a vehicle body of a rail transit high-speed motor train unit is characterized by comprising: the beam body 1 is arranged on two sides of the bottom of the vehicle body and extends along the length direction of the vehicle body; the frame 2 is connected with the beam bodies 1 on the two sides along the width direction of the vehicle body; the sealing plate 3 is at least fixedly connected with the frame 2 to form a supporting plane of the bottom of the vehicle body; the beam body 1 comprises a first supporting surface 11, the first supporting surface 11 supports the edge of the frame 2, and a gap is formed between the top of the edge and the bottom of the sealing plate 3; the bottom of the first supporting surface 11 of the beam body 1 is provided with an installation cavity 12 penetrating through the beam body 1 in the length direction, one end of a connecting piece for connecting the beam body 1 and the frame 2 is positioned in the installation cavity 12, and the other end of the connecting piece is positioned in a gap; wherein, the beam body 1, the frame 2 and the closing plate 3 are all made of composite materials.

The whole underframe structure of the invention adopts a composite material structure, wherein the beam body 1 and the frame 2 form a framework of the underframe structure, the purposes of bearing and transferring force are realized through the connection of the connecting pieces, after the beam body 1 and the frame 2 are connected, the sealing plate 3 is very convenient to install, the positioning in the height direction can be realized through the top of the frame 2, then the sealing plate 3 and the frame 2 can be only connected through the connecting pieces, or the sealing plate 3 and the frame 2 as well as the sealing plate 3 and the beam body 1 are respectively connected through the connecting pieces, one part of the connecting pieces for connecting the frame 2 and the beam body 1 is hidden in the installation cavity 12, and the other part of the sealing plate is hidden in the gap between the sealing plate 3 and the top of the edge of the frame 2, thereby ensuring the aesthetic property of the whole structure of the car body; the same weight reduction of the beam 1 is obtained for the design of the mounting cavity 12.

In order to reduce the installation difficulty of the connecting piece for connecting the frame 2 and the beam body 1, the hole site 13 for the connecting piece to run through on the beam body 1 is a strip-shaped hole and comprises a first section 13a and a second section 13b, the width of the first section 13a is greater than that of the second section 13b, the end part of the connecting piece enters the installation cavity 12 from top to bottom through the first section 13a, and the side wall of the second section 13b is used for limiting the end part of the connecting piece.

In the process of connecting the beam body 1 and the frame 2, the connecting piece generally adopts a bolt structure, even if a special connecting piece structure is adopted, the connecting piece is allowed to be provided with a main body and an end part, and the size of the end part is larger than that of the main body, so that the connecting piece can be clamped in the mounting cavity 12. In the following description, the connecting member is taken as an example of a bolt structure, the connecting member penetrates through a through hole located at the edge from bottom to top, in order to avoid falling of the connecting member, the connecting member can be fixed at the top of the connecting member through a nut, then the end located at the bottom enters the mounting cavity 12 from the first section 13a of the hole location 13, then the end slides towards the second section 13b, after the connecting member slides in place, the nut is screwed, the edge and the beam body 1 can be fixed, and the stability of the whole framework form is ensured through the limiting of the side wall of the second section 13b and the locking effect of the nut.

As an optimized mode of the frame 2, the connecting portion 21 of the frame 2 and the closing plate 3 is a hollow pipe structure, the pipe structure forms an edge of the frame 2 by removing end material, the edge includes a connecting wall 21a and two reinforcing walls 21b, the two reinforcing walls 21b are symmetrically arranged on two sides of the connecting wall 21a, and the connecting wall 21a is fixedly connected with the beam body 1.

The tubular body structure referred to in this preferred embodiment may be either end-capped, as shown in fig. 5, or open, as shown in fig. 6, and neither form affects the formation of the reinforcing wall 21b and the connecting arms after the material removal, except that a side wall connecting the connecting wall 21a and the reinforcing wall 21b is included when the end of the tubular body structure is capped. The integrity between the reinforcing wall 21b and the connecting wall 21a is ensured by removing the material of the integral structure, and the structural stability of the connecting position is effectively improved. To the cross-sectional profile design of body structure, can select square, rectangle, trapezoidal or other different nature structures, only need to guarantee including with the roof beam body 1 laminating smooth connecting wall 21a can, the reinforcing wall 21b that the material formed after removing is plane or curved surface to and, the angle between reinforcing wall 21b and the connecting wall 21a all can design and select according to actual production conditions.

In order to further strengthen the connection position of the frame 2 and the beam body 1, the connecting device further comprises a connecting seat 4, wherein the connecting seat 4 comprises a plate body 41 and two limiting plates 42, the two limiting plates 42 are arranged in parallel and are vertically connected with the plate body 41, and the edge of the plate body 41 forms an extension section 41a relative to the limiting plates 42; the extending section 41a is fixedly connected with the beam body 1, and the part of the plate body 41 located between the two limiting plates 42 is arranged between the edge of the frame 2 and the beam body 1, and the three parts are fixedly connected.

The setting through connecting seat 4 among this preferred scheme is remedied the influence to the intensity that roof beam body 1 caused because hole site 13 is seted up, and the setting of plate body 41 has increased the local thickness of roof beam body 1 junction, and the setting of limiting plate 42 is effectual again to plate body 41's structural strength reinforcing, and the setting of extension section 41a makes the influence range increase of above-mentioned reinforcing effect to the effectual structural reliability who promotes the junction.

The connection base 4 of the present preferred embodiment can be disposed at any position in the middle of the beam 1 as shown in fig. 8, or can be disposed at the edge portion of the beam 1 as shown in fig. 9, and it is within the scope of the present invention to connect two adjacent beams 1. For the choice of material for the connection socket 4, preferably a composite material moulding is used, but metal structures may be used, also within the scope of the invention,

in order to reduce the weight of the beam body 1 as much as possible on the basis of ensuring the structural strength of the beam body 1, at least one through structural cavity 14 is further arranged on the beam body 1, and the structural cavity 14 and the mounting cavity 12 are arranged in parallel; wherein at least one structural cavity 14 is filled with a reinforcing rod body 15.

In the specific implementation process, the cross-sectional area of the beam body 1 is increased as much as possible, so that the structural strength is beneficial, but the weight is increased, by means of the optimal scheme, the optimal range of the cross-sectional size is guaranteed, materials can be saved by means of the arrangement of the cavities, the side walls between the structural cavities 14 and the installation cavity 12 and the side walls between the structural cavities 14 can play the role of reinforcing ribs, and the structural strength is guaranteed to a certain extent. However, in the preferred embodiment, in order to ensure the structural stability of the beam 1, a reinforcing rod body 15 is provided in at least one of the structural cavities 14.

For the reinforcing rod body 15, a solid structure or a hollow structure may be selected, and for the material aspect, a metal structure or a composite material structure is also within the scope of the present invention. After filling the reinforcing rod 15 into the structural cavity 14, in order to ensure the stability of the position of the reinforcing rod 15, the reinforcing rod 15 needs to be fixed, and the fixing manner includes, but is not limited to, connecting member connection, bonding, and the like. When the reinforcing rod body 15 and the beam body 1 are connected through the connecting piece and the reinforcing rod body 15 is of a hollow structure, the strip-shaped holes comprising the first section 13a and the second section 13b can be arranged at the corresponding positions of the beam body 1 and the reinforcing rod body 15, and the end part of the connecting piece, which is leaked after entering the hollow part, can be fixed through a nut and other structures; when connecting the reinforcing rod body 15 and the beam body 1 through the connecting piece and reinforcing the rod body 15 to be a solid structure, a through hole can be formed in the beam body 1, and a threaded hole is formed in the reinforcing rod body 15, so that the bolt passing through the through hole can be fixed through the threaded hole.

As a preference of the above embodiment, the sealing plate 3 is formed by splicing a plurality of structural units 31 distributed in a matrix; the splicing positions of two adjacent structural units 31 along the length direction of the vehicle body are connected through a staggered splicing structure, the staggered splicing structure comprises a retracted area 31a arranged at the edge of one structural unit 31 and a convex edge 31b arranged at the edge of the other adjacent structural unit 31, and the convex edge 31b is attached to the retracted area 31a to realize splicing; the splicing positions of two adjacent structural units 31 in the width direction of the vehicle body are connected by connecting with the same frame 2.

When using dislocation mosaic structure, can all set up indentation area 31a in a constitutional unit 31 both sides, and all set up protruding edge 31b in an adjacent constitutional unit 31 both sides, perhaps, set up indentation area 31a and protruding edge 31b respectively in a constitutional unit 31 both sides, all can realize the purpose in this optimization scheme, when protruding edge 31b is connected with roof beam body 1, also can set up the depressed area at the edge of roof beam body 1 to adaptation protruding edge 31 b's installation. The two adjacent structural units 31 are respectively connected through the frame 2, so that the two adjacent structural units 31 are butted, the structure of the structural units 31 can be simplified, only the arrangement position of the frame 2 is adjusted, and the implementation cost is low.

In the process of forming the structural unit 31, a structure with a uniform cross section is preferably formed in the vehicle body direction by means of composite material pultrusion, so that the production efficiency can be effectively increased, and similarly, in order to reduce the weight of the material, a cavity structure can be directly formed in the pultrusion process.

In order to ensure the connection effectiveness in the process of connecting the two connected structural units 31 through the frame 2, the size of the frame 2 structure in the length direction of the vehicle body needs to be increased properly, but this way inevitably increases the cost of the structure, and in order to solve the technical problem, the frame 2 comprises a main body and a transition plate 22, the edge of the transition plate 22 is arranged on the main body, the transition plate 22 is arranged on the top of the main body, and the two ends of the vehicle body in the length direction extend outwards relative to the main body; the transition plate 22 is fixed with the main body through a connecting piece, the structure units 31 are fixed with the extending parts of the transition plate 22 through connecting pieces, wherein the edge positions of the structure units 31 on the transition plate 22 are provided with slope structures, the tops of the slope structures of two adjacent structure units 31 are butted, and the bottoms form a space for accommodating the connecting pieces connecting the transition plate 22 and the main body.

The requirement on the size of the main body is effectively reduced through the arrangement of the transition plate 22, the supporting area of the structural unit 31 is increased through the arrangement of the extension part, and meanwhile, the connecting difficulty with the structural unit 31 is also reduced.

In order to make chassis structure and automobile body support frame 5 and automobile body side wall 6 carry out better connection, 1 top of roof beam body upwards extends has along body 16, it is provided with second holding surface 17 to be close to the inside one side of automobile body along body 16, second holding surface 17 supports automobile body support frame 5, it is spacing to carry out the horizontal direction to automobile body support frame 5 along body 16, and along in 16 embedding automobile body support frame 5 surperficial recesses, form the smooth surface of laminating with automobile body side wall 6 with automobile body support frame 5.

After whole chassis structure installation is accomplished, accessible second supporting plane and along the setting of body 16 fix a position automobile body support frame 5, in order to make automobile body support frame 5 carry out stable fixed, can carry out configuration optimization and obtain the bigger link of area of coverage and be connected with the laminating of roof beam body 1 to it, of course, automobile body support frame 5's structure is not in the protection scope of this application, wherein, the setting along body 16 except realizing the location can also cover the gap that automobile body support frame 5 and second holding surface 17 are connected, thereby improve roof beam body 1 and automobile body support frame 5's connection stability.

After the installation of automobile body side wall 6 is accomplished, the accessible connecting piece is connected it with automobile body support frame 5 and edge 16, for further assurance automobile body side wall 6's position accuracy and stability, the outside that roof beam body 1 is located the automobile body both sides is provided with cell body 18, and cell body 18 sets up along automobile body length direction, and cell body 18 is used for holding the bulge on the automobile body side wall 6.

The protruding parts are matched with the groove bodies 18, so that the side wall 6 of the automobile body is limited by the groove bodies 18 in the height direction and is stable, and the protruding parts on the side wall 6 of the automobile body are also connected with the beam body 1, so that the strength of the connecting position is enhanced.

In the process of processing the frame 2, the frame 2 can be integrally formed through the autoclave forming process, the overall structure of the forming process is strong, but when the processing efficiency is considered, the frame 2 comprises two horizontal pipe bodies 23 arranged in parallel and a connecting structure 24 for connecting the two horizontal pipe bodies 23. The horizontal pipe body 23 and the connecting structure 24 can be obtained in a pultrusion mode, so that efficient production can be realized; connection structure 24 can include the two parts of butt joint, and two parts splice the back form carry out the region of cladding to horizontal body 23 can, two parts accessible connecting piece are fixed, and each part is also fixed through the connecting piece with horizontal body 23 to guarantee the stability of whole frame 2 structure.

The foregoing illustrates and describes the principles, general features, and advantages of the present invention. It will be understood by those skilled in the art that the present invention is not limited to the embodiments described above, which are described in the specification and illustrated only to illustrate the principle of the present invention, but that various changes and modifications may be made therein without departing from the spirit and scope of the present invention, which fall within the scope of the invention as claimed. The scope of the invention is defined by the appended claims and equivalents thereof.

Claims

1. The utility model provides a carbon fiber composite material chassis structure of high-speed EMUs automobile body of track traffic, its characterized in that includes:

the beam body, the frame and the sealing plate are all of composite material structures;

the sealing plate is formed by splicing a plurality of structural units distributed in a matrix;

2. The carbon fiber composite underframe structure for the car body of the rail transit high-speed motor train unit according to claim 1, wherein at least one through structural cavity is further arranged on the beam body, and the structural cavity is arranged in parallel with the mounting cavity;

3. The carbon fiber composite underframe structure for the car body of the rail transit high-speed motor train unit as claimed in claim 1, wherein the frame comprises a main body and transition plates, the edges are arranged on the main body, the transition plates are arranged on the top of the main body and extend outwards relative to the main body at two ends of the car body in the length direction;

4. The carbon fiber composite underframe structure for the car body of the rail transit high-speed motor train unit according to claim 1, wherein an edge body extends upwards from the top of the beam body, a second supporting surface is arranged on one side of the edge body close to the inside of the car body, the second supporting surface supports the car body supporting frame, the edge body horizontally limits the car body supporting frame, the edge body is embedded into a groove in the surface of the car body supporting frame, and the edge body and the car body supporting frame form a smooth surface attached to the side wall of the car body.

5. The carbon fiber composite underframe structure for the car body of the rail transit high-speed motor train unit according to claim 4, wherein groove bodies are arranged outside the two sides of the car body of the beam body, the groove bodies are arranged along the length direction of the car body, and the groove bodies are used for accommodating the protruding parts on the side walls of the car body.

6. The carbon fiber composite underframe structure for car bodies of rail transit high-speed motor train units according to claim 1, wherein the frame comprises two horizontal pipe bodies arranged in parallel and a connecting structure for connecting the two horizontal pipe bodies.